transcript
- 1. Authors: Scott-Conner, Carol E. H.; Dawson, David L. Title:
Operative Anatomy, 3rd Edition Copyright 2009 Lippincott Williams
& Wilkins > Front of Book > Authors Authors Carol E. H.
Scott-Conner M.D., PH.D., M.B.A. Professor and Head Department of
Surgery; Professor, Anatomy & Cell Biology, University of Iowa
Roy J. and Lucille A. Carver College of Medicine Iowa City, Iowa
David L. Dawson PH.D. Senior Lecturer of Anatomy, Faculty of Life
Sciences University of Dundee, Dundee, Scotland With Illustrations
By Mark K. Shirazi Gary G. Wind M.D., F.A.C.S. Thomas Weinzerl
Contributors Laura A. Adam Fellow Department of Surgery,
Barnes-Jewish Hospital, St. Louis, Missouri Beth A. Ballinger M.D.
Mayo Clinic, Rochester, Minnesota Phillip C. Camp M.D. Division of
Thoracic Surgery, Brigham and Women's Hospital, Boston,
Massachusetts Adam J. Dinnewitzer M.D. Research Fellow
- 2. Department of Colorectal Surgery, Cleveland Clinic Florida,
Weston, Florida M. Victoria Gerken M.D. Visalia, California Sean P.
Hedican M.D. Associate Professor Division of Urology, Department of
Surgery, University of Wisconsin-Madison, University of Wisconsin
Hospitals and Clinics, Madison, Wisconsin Jamal J. Hoballah M.D.
Professor Division of Vascular Surgery, Department of Surgery,
University of Iowa, Roy J. and Lucille A. Carver, College of
Medicine, Iowa City, Iowa James R. Howe M.D. Professor, Director
Endocrine Surgery, Department of Surgery, University of Iowa, Roy
J. and Lucille A. Carver, College of Medicine, Iowa City, Iowa G.
Patrick Kealey M.D., F.A.C.S., F.C.C.M. Professor Department of
Surgery, University of Iowa, Roy J. and Lucille A. Carver, College
of Medicine, Iowa City, Iowa John Kellum Professor Division of
General Surgery, Department of Surgery, Virginia Commonwealth
University, School of Medicine, Richmond, Virginia Kemp H.
Kernstine M.D., Ph.D. Director Thoracic Surgery, City of Hope,
Duarte, California Timothy F. Kresowik M.D. Professor Division of
Vascular Surgery, Department of Surgery, University of Iowa, Roy J.
and
- 3. Lucille A. Carver, College of Medicine, Iowa City, Iowa
Geeta Lal M.D., M. Sc. Assistant Professor Division of Surgical
Oncology and Endocrine Surgery, Department of Surgery, University
of Iowa, Roy J. and Lucille A. Carver, College of Medicine, Iowa
City, Iowa James W. Maher M.D., F.A.C.S Professor Division of
General Surgery, Department of Surgery, Virginia Commonwealth
University, School of Medicine, Richmond, Virginia Samuel M.
Maurice M.D. Fellow Department of Plastic and Reconstructive
Surgery, Rush University Medical Center, Chicago, Illinois Amanda
M. Metcalf M.D. Professor Division of Gastrointestinal, Minimally
Invasive and Bariatric Surgery, Department of Surgery, University
of Iowa, Roy J. and Lucille A. Carver, College of Medicine, Iowa
City, Iowa Stephen C. Rayhill M.D. Associate Professor of Surgery
Director of Pancreas Transplantation, Division of Liver/Pancreas
Transplantation, Oregon Health & Science University, Portland,
Oregon Isaac Samuel M.D., F.R.C.S. Assistant Professor Section of
Gastrointestinal Surgery, Department of Surgery, University of
Iowa, Roy J. and Lucille A. Carver, College of Medicine, Iowa City,
Iowa W. John Sharp M.D. Sidney E. Ziffren M.D. Professor of Surgery
Division of Vascular Surgery, Department of Surgery, University of
Iowa, Roy J. and Lucille A. Carver, College of Medicine, Iowa City,
Iowa
- 4. Kenneth B. Simon M.D., M.B.A. Medical Officer and Consultant
Centers for Medicare and Medicaid Services, Baltimore, Maryland
Timothy L. Van Natta M.D. Department of Surgery, Harbor-UCLA
Medical Center, Torrance, California Steven D. Wexner M.D.,
F.A.C.S., F.R.C.S. Professor The Cleveland Clinic Foundation,
Health Sciences Center of the Ohio State University, Clinical
Professor, Department of Surgery, University of South Florida,
College of Medicine, Chairman and Residency Program Director and,
Chief of Staff, Department of Colorectal Surgery, Cleveland Clinic
Florida, Weston, Florida Neal W. Wilkinson M.D. Clinical Associate
Professor Division of Surgical Oncology and Endocrine Surgery,
Department of Surgery, University of Iowa, Roy J. and Lucille A.,
Carver College of Medicine, Iowa City, Iowa Richard D. Williams
M.D. Professor and Chair Department of Urology, University of Iowa,
Roy J. and Lucille A., Carver College of Medicine, Iowa City, Iowa
You Min Wu M.D. Professor Transplantation Division, Department of
Surgery, University of Arkansas for Medical Sciences, Little Rock,
Arkansas
- 5. Authors: Scott-Conner, Carol E. H.; Dawson, David L. Title:
Operative Anatomy, 3rd Edition Copyright 2009 Lippincott Williams
& Wilkins > Front of Book > Dedication Dedication
Dedicated to the students, residents, and fellows ! who continue to
amaze and instruct us.
- 6. Authors: Scott-Conner, Carol E. H.; Dawson, David L. Title:
Operative Anatomy, 3rd Edition Copyright 2009 Lippincott Williams
& Wilkins > Table of Contents > Section I - The Head and
Neck > Introduction Introduction This anatomically complex
region is presented in four sections: the face and parotid region
(Chapter 1), endoscopy of the upper respiratory tract (Chapter 2),
the midline of the neck and structures approached through the
midline (Chapters 3, 4, 5, 6 and 7), and the lateral neck and
structures approached from the side (Chapters 8, 9, 10, 11, 12 and
13). Within each section, procedures commonly performed by general
surgeons are used to illustrate regional anatomy. For descriptions
of more complex procedures, the reader should consult an atlas of
plastic surgery or surgery of the head and neck (see references
listed below). References 1. Lore JM, Medina JM. An Atlas of Head
and Neck Surgery. Philadelphia: Saunders; 2004. (This classic text
provides detailed information on specialized surgical techniques.)
2. Thorne CH, Beasley RW, Aston SJ, et al., eds. Grabb and Smith's
Plastic Surgery. 6th ed. Philadelphia: Lippincott Williams &
Wilkins; 2007. (A brief but comprehensive overview of plastic
surgery, this book includes information on suturing facial
lacerations and local flaps.)
- 7. Authors: Scott-Conner, Carol E. H.; Dawson, David L. Title:
Operative Anatomy, 3rd Edition Copyright 2009 Lippincott Williams
& Wilkins > Table of Contents > Section I - The Head and
Neck > The Face > Introduction Introduction Facial incisions
are designed to preserve facial symmetry and motion and to minimize
scarring. To remove small skin tumors, make elective incisions in
natural skin !wrinkle lines,!! if possible (Fig. 1). Generally,
these lines run perpendicular to the underlying muscles of facial
expression, as they are formed by the repetitive pleating of the
skin caused by the action of these muscles. Scars that fall in
these lines will be less conspicuous than those that cross these
lines. Traumatic lacerations that cross these lines can sometimes
be dbrided or modified by Z-plasty to conform to natural wrinkle
lines. Approximate the eyebrow and vermilion border of the lip with
special precision because even a small degree of malalignment will
be permanently obvious. Never shave the eyebrow as regrowth of
eyebrow hair is unpredictable. The muscles of facial expression
(Fig. 2) are innervated by the seventh cranial nerve, aptly named
the facial nerve. The anatomy of the facial nerve and parotid
region are illustrated in Chapter 1. Deep lacerations of the cheek
may divide branches of the facial nerve or the parotid (Stensen's)
duct. Evaluate nerve function by asking the patient to raise and
lower the eyebrows (temporal branches of the facial nerve), close
the eyes tightly (zygomatic branches), and smile (zygomatic and
buccal branches). If a nerve injury is diagnosed, attempt primary
repair. Look inside the mouth, gently retracting the cheek with a
tongue blade, and identify the internal opening of the parotid duct
as a small punctum opposite the maxillary second molar. Cannulate
this with a fine Silastic tube. The appearance of the tube within
the wound confirms injury to the duct. Identify both ends of the
duct, repairing it with fine, interrupted sutures of an absorbable
material. Use the Silastic tube to stent the repair. Close deep
lacerations in layers, carefully approximating muscle, fascia, and
skin. Complex injuries involving muscle, nerve, or the parotid duct
are best repaired in the operating room.
- 8. P.4
- 9. References 1. Kreissl CJ. The selection of appropriate lines
for elective surgical incisions. Plast Reconstr Surg. 1951;8:1.
(This brief classic paper discusses the rationale for choosing
various incisions to minimize scarring.) 2. Hollier L Jr, Kelley P.
Soft tissue and skeletal injuries of the face. In: Thorne CH,
Beasley RW, Aston SJ, et al., eds. Grabb and Smith's Plastic
Surgery. 6th ed. Philadelphia: Lippincott Williams & Wilkins;
2007:315!332. 3. Brown DJ, Jaffee JE, Henson JK. Advanced
laceration management. Emerg Med Clin North Am. 2007;25:83!99. 4.
Armstrong BD. Lacerations of the mouth. Emerg Med Clin North Am.
2000;18:471!480.
- 10. Authors: Scott-Conner, Carol E. H.; Dawson, David L. Title:
Operative Anatomy, 3rd Edition Copyright 2009 Lippincott Williams
& Wilkins > Table of Contents > Section I - The Head and
Neck > The Face > 1 - Parotidectomy 1 Parotidectomy The
parotid gland is divided into a superficial lobe and a deep lobe
for purposes of surgical dissection. Because 70% to 80% of the
parotid tissue lies in the superficial lobe, most tumors, whether
benign or malignant, arise in this lobe. Superficial lobectomy
remains the standard treatment for small benign tumors. Simple
enucleation is unwise, even when technically feasible, because even
histologically benign tumors are likely to recur. A recurrent tumor
is much more difficult to resect with preservation of the facial
nerve and is more likely to be malignant. Steps in Parotidectomy
Creation of incision and elevation of flaps Identification of main
trunk of facial nerve Dissection in plane between superficial and
deep lobe, preserving facial nerve branches (superficial
parotidectomy) 0r: Dissection of deep lobe from around branches of
facial nerve and ligation of parotid duct Hallmark Anatomic
Complications Partial facial paralysis resulting from facial nerve
injury Gustatory sweating (Frey syndrome) resulting from aberrant
reinnervation Patchy facial numbness resulting from damage to
auriculotemporal nerve List of Structures Parotid Gland and
Associated Structures Parotid gland Superficial lobe Deep lobe
Parotid duct Superficial parotid lymph nodes Parotid fascia
- 11. Deep cervical fascia Nerves Facial nerve Temporofacial
division Temporal branches Zygomatic branches Buccal branches
Cervicofacial division Marginal mandibular branch Cervical branch
Great auricular nerve Auriculotemporal nerve Muscles Masseter
Sternocleidomastoid Digastric Posterior belly of digastric Platysma
Vessels External carotid artery Superficial temporal artery
Transverse facial artery Maxillary artery External jugular vein
Superficial temporal vein Maxillary vein Retromandibular vein
Facial vein Landmarks Lateral palpebral commissure (canthus)
External acoustic meatus Mandible Ramus of mandible Zygomatic arch
Temporal bone Tympanic portion
- 12. P.6 P.7 Mastoid process Styloid process Styloid vaginal
process Stylomastoid foramen Atlas Transverse process The safe
performance of superficial parotidectomy involves careful
identification and preservation of the facial nerve and its
branches (Fig. 1.1A). Total parotidectomy is sometimes required
when the deep lobe is involved. This procedure is briefly described
in Fig. 1.5. More complex problems, including reconstruction of
branches of the facial nerve, are covered in the references at the
end of this chapter. In this chapter, the anatomy of the parotid
region is illustrated as it is demonstrated during the performance
of parotidectomy. There are three potential anatomic complications
of parotid surgery. The first one, injury to the facial nerve or
its branches, can be avoided by careful dissection as emphasized
here. The second complication, gustatory sweating or Frey syndrome,
appears to result from aberrant regeneration of nerve fibers
divided, of necessity, during dissection. Several techniques have
been proposed to prevent it, including interposition of a flap of
sternocleidomastoid muscle or use of a bioprosthesis. This
interposed material presumably acts as a barrier to nerve fiber
regrowth. The third complication is division of the
auriculotemporal nerve, which results in patchy numbness.
Positioning the Patient (Fig. 1.1) Technical Points Position the
patient supine on the operating table. General anesthesia is
preferred; however, avoid muscle relaxants, so that nerve function
can be assessed intraoperatively, if necessary. Place the operating
table in a head-up position to improve exposure and minimize
bleeding. Turn the head to the contralateral side and slightly
hyperextend the neck to enhance exposure of the preauricular
region. Place a cotton plug in the external ear to prevent blood
accumulation within the external acoustic meatus and on the
eardrum. Drape an operative field that includes the external ear
and mastoid process, the neck, the angle of the mouth, and the
lateral palpebral commissure of the eye. This allows you to observe
motion of the angle of the mouth or eyelid in response to
stimulation of facial nerve branches, which may assist in safe
dissection.
- 13. Figure 1-1 Positioning the Patient Plan the preauricular
skin incision so that it lies in a skin fold (Fig. 1.1B). Draw an
incision in the skin fold anterior to the ear and extend the line
of incision along the inferior margin of the mandible anteriorly.
This incision provides adequate exposure to the area, can be
extended if necessary, and lies in an inconspicuous position behind
the mandible. Extend the incision posteriorly in an inverted T to
provide additional exposure in difficult cases. Deepen the incision
through the platysma muscle and achieve hemostasis with
electrocautery.
- 14. Anatomic Points The parotid region is bounded anteriorly by
the mandibular ramus, posteriorly by the tympanic part of the
temporal bone and the mastoid process, and superiorly by the
external acoustic meatus, zygomatic arch, and temporomandibular
joint (Fig. 1.1C). The deep structures in this region include the
styloid process and, more inferiorly, the transverse process of the
atlas. The gland overlies portions of the surrounding masseter
muscle, the sternocleidomastoid muscle, and the posterior belly of
the digastric muscle. The parotid is enclosed in a sheath derived
from the superficial (investing) lamina of deep cervical fascia.
Branches of the great auricular nerve (the largest sensory branch
of the cervical plexus, with fibers derived from C2 and C3), part
of the platysma muscle, and a variable number of superficial
parotid lymph nodes (draining the auricle, external acoustic
meatus, eyelids, and frontotemporal region of the scalp) are
superficial to the gland. Elevation of Flaps to Expose the Parotid
Gland (Fig. 1.2) Technical Points Elevate flaps in the plane just
superficial to the dense superficial parotid fascia. Use skin hooks
or fine-pointed rake retractors to exert upward traction on the
skin flap because the plane is developed between subcutaneous
tissue and superficial parotid fascia by sharp dissection. Identify
the main trunk of the great auricular nerve and preserve it.
Branches from the great auricular nerve will enter the substance of
the parotid gland and must be divided. Divide the posterior facial
vein, but preserve the retromandibular vein to avoid venous
engorgement. As the dissection progresses anteriorly, peripheral
branches of the facial nerve will emerge from the parotid to
innervate facial muscles. Look for them, and take care to preserve
them by dissecting in a plane superficial to these terminal
branches. Terminate the dissection at the anterior and inferior
margins of the parotid gland to avoid injuring these tiny terminal
branches. Anatomic Points The flap to be elevated includes the
skin, superficial fascia, and platysma muscle. The anterior
branches of the great auricular nerve, which lie deep to the
platysma but superficial to the parotid fascia, give the surgeon a
guide for attaining the proper plane of dissection. As the anterior
margin of the parotid gland is reached, however, motor branches of
the facial nerve (VII) that innervate the very superficial muscles
of facial expression will begin to emerge into the operating field.
Although branches of the great auricular nerve must necessarily be
sacrificed, branches of the facial nerve must be preserved.
Identification of the Main Trunk of the Facial Nerve (Fig. 1.3)
Technical Points Locate the anterior border of the
sternocleidomastoid muscle and mobilize it from the
- 15. P.8 P.9 posterior aspect of the parotid gland by incising
the fascia. The alternative approach of following the tail of the
parotid gland to define the inferior border risks injury to the
mandibular branch of the facial nerve. Incise the connective tissue
between the external acoustic meatus and the parotid. Visualize the
posterior belly of the digastric muscle. Careful sharp and blunt
dissection in the plane along the periosteum of the mastoid process
provides a safe route to deeper structures. Spread the tissues
gently, using the tips of a fine-pointed hemostat, in a direction
parallel to the anticipated path of the nerve. Expose the main
trunk of the facial nerve about one fingerbreadth inferior to the
membranous portion of the external acoustic canal and the same
distance anterior to the mastoid process (Fig. 1.3A). Identify the
nerve by its position and the characteristic appearance of a nerve
trunk (white, glistening, with a faintly discernible linear
structure, and often with one or two minute longitudinal blood
vessels visible on the surface). The nerve will be a sizeable
structure, commonly about 2 to 3 mm in diameter. Trace the trunk of
the facial nerve into the parotid gland and commence dissection,
progressing from proximal to distal, by spreading a fine hemostat
parallel and superficial to the nerve. Some surgeons prefer to use
a blunt Freer elevator to develop the plane. Anatomic Points Bony
landmarks of this region include the zygomatic arch (superior), the
ramus of the mandible (deep), and the styloid process (posterior)
(Fig. 1.3B). Although it would seem reasonable to locate the
stylomastoid foramen, and thus the main trunk of the facial nerve,
by locating the interval between the mastoid process and the
styloid process, this cannot be accomplished reliably. The
superficial lamina of the deep cervical fascia, here investing the
sternocleidomastoid muscle and the parotid gland and fusing with
the perichondrium and periosteum with which it comes into contact,
effectively prevents palpation of deeper structures. In addition,
the styloid process is quite variable in that it may be shielded by
the variably developed styloid vaginal process, is frequently
absent, and can vary in length from 0.1 to 4.2 cm.
- 16. Figure 1-2 Elevation of Flaps to Expose the Parotid
Gland
- 17. Figure 1-3 Identification of the Main Trunk of the Facial
Nerve By cutting the fascia and retracting the sternocleidomastoid
muscle posteriorly and the parotid gland anteriorly, one can
visualize the posterior belly of the digastric muscle and the
anterior border of the mastoid process (Fig. 1.3C). At this point,
the main trunk of the facial nerve (VII) is directed almost in a
coronal plane, running from the stylomastoid foramen to the
!plane!! between the superficial and deep lobes of the parotid
gland, where it makes an approximate right-angle turn to run
anteriorly in the sagittal plane. If the trunk of the nerve cannot
be located easily, bluntly dissect slightly anteriorly rather than
posteriorly, restricting the vertical extent of the dissection to
the region from the tip of the mastoid craniad to about 1 to 2 cm.
This will prevent trauma to the only other sizeable nerve in this
region, the auriculotemporal nerve. The auriculotemporal nerve is a
sensory branch of the mandibular division of the trigeminal nerve,
which innervates the temporomandibular joint, external acoustic
meatus,
- 18. tympanic membrane, most of the anterior part of the
external ear, and most of the temporal region. It enters the region
at the level of the external acoustic meatus. Removal of the
Superficial Lobe (Fig. 1.4) Technical Points Remove the superficial
lobe by dissection in the plane of the branches of the facial
nerve. Elevate the parotid by traction with a gauze sponge, by
grasping it with forceps, or by placing traction sutures. Identify
the two major divisions of the facial nerve and trace each by
spreading in the plane immediately superficial to the nerve trunks.
Gently stimulate any structure in doubt before division. This may
be done by very gentle mechanical stimulation (gentle squeezing
with forceps or hemostat) or by the use of a disposable nerve
stimulator. Stimulation of a motor nerve, such as a branch of the
facial nerve, will cause a twitch of the innervated muscle in a
nonparalyzed patient. Motion of the eyelids or the corner of the
mouth, which were purposefully left exposed when the operative
field was draped, can easily be observed. Do not stimulate branches
of the facial nerve unless truly uncertain of the anatomy because
paresis may result from mechanical or electrical stimulation.
Attain hemostasis using fine suture ties. Use cautery judiciously,
taking care not to contact nerve fibers. Anatomic Points The facial
nerve usually separates into two major divisions at a point
posterior and slightly medial to the mandibular ramus, about one
third of the distance from the temporomandibular joint to the angle
of the mandible. The more superior temporofacial division is
usually smaller than the more inferior cervicofacial division.
Anatomists still debate the existence of distinct superficial and
deep parotid lobes, which are separated by the plane through which
the facial nerve passes. The anatomy is variable, and one or more
isthmi of parotid tissue connect the superficial and deep lobes.
However, by careful dissection immediately superficial to the
facial nerve, an apparent superficial lobe can be removed with a
minimum of trauma to other important structures traversing the
substance of the parotid gland. Isthmi of parotid tissue are
divided sharply as encountered. The facial nerve is immediately
superficial to the external jugular vein and its tributaries, which
are themselves superficial to the external carotid artery and its
regional branches (superficial temporal and maxillary
arteries).
- 19. P.10 Figure 1-4 Removal of the Superficial Lobe Dissection
of the Deep Lobe, Ligation of the Parotid Duct, and Closure of the
Wound (Fig. 1.5) Technical Points If the tumor involves the deep
lobe, dissection of parotid tissue from underneath and around the
facial nerve branches is necessary. Elevate the branches of the
facial nerve gently with a nerve hook and dissect parotid tissue
from around and beneath them (Fig. 1.5A). Do not hesitate to
sacrifice nerve branches that are involved by tumor. Perform an
immediate reconstruction using a nerve graft (see references).
Ligate the parotid duct. Check the field for hemostasis and close
with fine, interrupted sutures. Leave a small drain under the flap
(Fig. 1.5B).
- 20. Figure 1-5 Dissection of the Deep Lobe, Ligation of the
Parotid Duct, and Closure of the Wound Anatomic Points Removal of
the deep lobe presents many technical difficulties, which may
ultimately result in picking out parotid tissue piecemeal. Care
must be taken to avoid trauma to the terminal branches of the
facial nerve. The number of branches of the facial nerve within the
parotid gland is variable, and there are fine anastomoses between
the terminal points of some branches. It is convenient to consider
five major branches that correspond to the common anatomic pattern
and the typical pattern of innervation. The first branch after the
facial nerve exits the stylomastoid foramen is the posterior
auricular, which passes posterosuperiorly
- 21. P.11 between the parotid gland and anterior border of the
sternocleidomastoid to supply the muscles of facial expression
posterior to the external acoustic meatus. The main trunk of the
facial nerve then supplies the muscles originating from the styloid
process and the posterior belly of the digastric muscle. On
entering the parotid gland proper, the nerve divides into its
temporofacial and cervicofacial divisions. The temporofacial
division subsequently divides into several branches. The temporal
branches supply the auricular muscles, muscles of the forehead, and
most of the orbicularis oculi. The zygomatic branches innervate
part of the orbicularis oculi, muscles of the nose, and most
elevators of the upper lip. The buccal branches innervate the
muscles of both lips and the buccinator muscle. The cervicofacial
branches typically include a single marginal mandibular branch and
a single cervical branch. The marginal mandibular branch supplies
the muscles of the lower lip. Damage to this branch causes a severe
deformity, which is especially pronounced during phonation. There
are frequently multiple anastomoses between branches, resulting in
the information of a parotid plexus (pes anserinus of the face).
This is especially true with the temporofacial branches. The
external jugular vein and its regional tributaries, the superficial
temporal vein, maxillary vein, and facial vein, can all be ligated
with impunity. The still deeper external carotid artery and its
regional ramifications, the superficial temporal artery (and its
sole major branch, the transverse facial artery), and the
(internal) maxillary artery can also be ligated. The deepest
parotid tissue should be approached very cautiously because of the
relationship of the gland to deeper structures!notably, the lateral
pharyngeal wall. The buccal branches of the facial nerve typically
lie just inferior to the duct. When ligating the parotid duct, be
careful not to injure this structure. The transverse facial artery
lies just superior to the duct and will generally need to be
ligated. Surgical References 1. Byers RM. Operations involving the
submandibular and sublingual glands. In: Fischer JE, Bland KI, eds.
Mastery of Surgery. 5th ed. Philadelphia: Lippincott Williams &
Wilkins; 2007:284!290. (Describes the anatomy of the submandibular
region in detail and gives surgical technique.) 2. Beahrs OH. The
surgical anatomy and technique of parotidectomy. Surg Clin North
Am. 1977;57:477. (An excellent description of anatomy and safe
technique backed by vast experience.) 3. Beahrs OH, Adson MA. The
surgical anatomy and technique of parotidectomy. Am J Surg.
1958;95:885. (Detailed analysis of the anatomy of the region as it
relates to surgical technique.)
- 22. 4. De Ru JA, van Benthem PP, Hordijk GJ. Morbidity of
parotid gland surgery: results one year post-operative. Eur Arch
Otorhinolaryngol. 2006;263:582!585. 5. Filho WQ, Dedivitis RA,
Rapoport A, et al. Sternocleidomastoid muscle flap preventing Frey
syndrome following parotidectomy. World J Surg. 2004;28:361 !364.
(Description of interposition technique.) 6. Johnson JT, Ferlito A,
Fagan JJ, et al. Role of limited parotidectomy in management of
pleomorphic adenoma. J Laryngol Otol. 2007;121:1126!1128. 7. Loree
TR, Tomljanovich PI, Cheney RT, et al. Intraparotid sentinel lymph
node biopsy for head and neck melanoma. Laryngoscope.
2006;116:1461!1464. (Discusses the rationale for including
parotidectomy when radical neck dissection is performed for
malignant melanoma of the head and neck and provides an alternative
technique of staging.) 8. Picon AI, Coit DG, Shaha AR, et al.
Sentinel lymph node biopsy for cutaneous head and neck melanoma:
mapping the parotid gland. Ann Surg Oncol. 2006;May 23:e-pub ahead
of print. 9. Prattico F, Perfetti P. Images in clinical medicine:
Frey's syndrome. N Engl J Med. 2006;355:66. (Concise description of
syndrome with illustration). 10. Sinha UK, Saadat D, Doherty CM, et
al. Use of AlloDerm implant to prevent Frey syndrome after
parotidectomy. Arch Facial Plast Surg. 2003;5:109!112.
(Interposition of bioprosthesis.) 11. Terrell JE, Kileny PR, Yian
C, et al. Clinical outcome of continuous facial nerve monitoring
during primary parotidectomy. Arch Otolaryngol Head Neck Surg.
1997;123:1081. 12. Woods JE. Parotidectomy: points of technique for
brief and safe operations. Am J Surg. 1983;145:678. (Presents
surgical shortcuts, emphasizing safety.) 13. Woods JE, Beahrs OH. A
technique for the rapid performance of parotidectomy with minimal
risk. Surg Gynecol Obstet. 1976; 142:87. (Summarizes the Mayo
Clinic technique; an excellent brief description.) 14. Zumeng Y,
Zhi G, Gang Z, et al. Modified superficial parotidectomy:
preserving both the great auricular nerve and the parotid gland
fascia. Otolaryngol Head Neck Surg. 2006;135:458!462.
- 23. Anatomic References 1. Bernstein L, Nelson RH. Surgical
anatomy of the extraparotid distribution of the facial nerve. Arch
Otolaryngol Head Neck Surg. 1984;110:177. (Reviews the common
variants in facial nerve anatomy.) 2. Davis RA, Anson BJ, Budinger
JM, et al. Surgical anatomy of the facial nerve and parotid gland
based upon a study of 350 cervicofacial halves. Surg Gynecol
Obstet. 1956;102:385. (Offers a detailed description of the anatomy
of the region, including variations in facial nerve distribution,
parotid gland and duct anatomy, and bony structures.) 3. McCormack
LJ, Cauldwell EW, Anson BJ. The surgical anatomy of the facial
nerve with special reference to the parotid gland. Surg Gynecol
Obstet. 1945;80:620. (Gives particular attention to the
relationship between deep and superficial lobes of the parotid
gland and the facial nerve.) 4. McKenzie J. The parotid gland in
relation to the facial nerve. J Anat. 1948;82:183. (Clearly
demonstrates the lobulated nature of the parotid gland enfolding
the facial nerve.) 5. McWhorter GL. The relations of the
superficial and deep lobes of the parotid gland to the ducts and to
the facial nerve. Anat Rec. 1917;12:149. (Provides an original
description of the isthmus of parotid tissue connecting the
superficial and deep lobes.) 6. Ruhalter A. Anatomy of the parotid
gland, submandibular triangle, and floor of the mouth. In: Fischer
JE, Bland KI, eds. Mastery of Surgery. 5th ed. Philadelphia:
Lippincott Williams & Wilkins; 2007:290!298. (Comprehensive
review of regional anatomy.) 7. Saunders JR, Hirata RM, Jaques DA.
Salivary glands. Surg Clin North Am. 1986;66:59. (Discusses anatomy
and surgical techniques for excision of submandibular gland tumors
as well as parotid gland tumors.)
- 24. Authors: Scott-Conner, Carol E. H.; Dawson, David L. Title:
Operative Anatomy, 3rd Edition Copyright 2009 Lippincott Williams
& Wilkins > Table of Contents > Section I - The Head and
Neck > Head and Neck Endoscopy > Introduction Introduction
Although not strictly operative procedures, laryngoscopy and
endotracheal intubation are frequently performed by surgeons.
Accurate diagnosis and management of upper airway problems demand a
thorough understanding of the anatomy of this region.
- 25. Authors: Scott-Conner, Carol E. H.; Dawson, David L. Title:
Operative Anatomy, 3rd Edition Copyright 2009 Lippincott Williams
& Wilkins > Table of Contents > Section I - The Head and
Neck > Head and Neck Endoscopy > 2 - Laryngoscopy and
Endotracheal Intubation 2 Laryngoscopy and Endotracheal Intubation
Laryngoscopy, or visualization of the larynx, is performed for both
diagnostic and therapeutic purposes. In this chapter, indirect (or
mirror) laryngoscopy and the visualization of the larynx for the
purpose of endotracheal intubation are discussed. The use of the
fiberoptic laryngoscope is not presented here because visualization
of the upper airway using this instrument is similar to that
described for fiberoptic bronchoscopy (see Chapter 24). Steps in
Indirect Laryngoscopy Adequate topical anesthesia Warm the mirror
to avoid fogging Gently introduce into back of oropharyns Steps in
Endotracheal Intubation Sniffing position C-spine stabilization if
trauma Adequate relaxation Straight blade goes over the epiglottis
Curved blade goes in front of the epiglottis Gentle pressure toward
the spine may be needed Pass Tube through Cords under Direct
Visualization Presence of CO2 confirms position in trachea Secure
in place Chest x-ray to verify position Anatomic Complications
Esophageal intubation Right mainstem bronchus intubation List of
Structures
- 26. P.14 Larynx Laryngeal inlet Rima glottides Thyroid
cartilage Vestibular folds Tongue Uvula Epiglottis Hyoid bone
Hyoglossus muscle Hyoepiglottic ligament Trachea Cricoid cartilage
Carina Pharynx Nasopharynx Oropharynx Laryngopharynx Palatine
tonsil Palatoglossal arch Indirect Laryngoscopy Mirror Laryngoscopy
(Fig. 2.1) Technical Points The patient should be seated facing the
examiner for this procedure. Adequate topical anesthesia of the
posterior pharynx is essential. Ask the patient to open the mouth
and stick out the tongue. Spray a topical anesthetic over the
tongue, soft palate, uvula, and posterior pharynx. Gently grasp the
tongue with a dry sponge or deflect it down with a tongue blade to
improve visibility. Use a headlamp to provide illumination. Warm a
dental mirror by holding it under hot running water so that it does
not fog when placed in the warm, moist environment of the posterior
pharynx. Place the mirror in the oropharynx, just anterior to the
uvula. Push back gently on the uvula and visualize the larynx by
adjusting the angle of the mirror slightly (Fig. 2.1). Observe the
vocal cords for color, symmetry, abnormal growths, and mobility
during phonation. The mirror can also be used to inspect the
lateral pharyngeal wall and can be reversed to view the posterior
nasopharynx.
- 27. Figure 2-1 Mirror Laryngoscopy Recognize that the mirror
produces an apparent reversal of anterior and posterior regions.
Visualization of the anterior commissure and base of the
epiglottis, the ventricles, and the subglottic regions is limited
by overhanging structures. Anatomic Points The upper aerodigestive
tract is divided into the oral cavity proper and the pharynx on the
basis of embryologic origin. The oral cavity is lined by epithelium
of ectodermal origin. It ends at about the level of the
palatoglossal arch. The pharynx is lined with epithelium that is
endodermally derived. It is divided into the nasopharynx, the
oropharynx, and the laryngopharynx. The nasopharynx is posterior to
the nose and superior to the soft palate. The oropharynx extends
from the soft palate to the hyoid bone. The laryngopharynx extends
from the hyoid bone to the cricoid cartilage. Endotracheal
Intubation
- 28. P.15 Positioning the Patient to Straighten and Shorten the
Airway before Intubation (Fig. 2.2) Technical Points Position the
patient supine with the neck slightly flexed and a small roll under
the head. Stand at the head of the operating table or bed. If you
are intubating a patient in bed, remove the headboard whenever
possible to gain better access to the patient. The !sniffing
position!! (Fig. 2.2A) decreases the distance from the teeth to the
larynx and facilitates visualization of the larynx. Hyperextension
of the neck (Fig. 2.2B) increases the distance from the teeth to
the larynx and makes intubation more difficult. Flexion of the head
on the neck compresses the airway, again making intubation more
difficult. Achieve the correct position by placing a small pillow
or folded sheet under the head. Do not manipulate the head and neck
in a patient with a known or possible cervical spine injury.
Displacement of vertebrae can cause irreversible damage to the
spinal cord. In the situation of known or suspected injury to the
cervical spine, fiberoptic laryngoscopy, blind nasotracheal
intubation (generally only successful in breathing patients), or
cricothyroidotomy is safer than orotracheal intubation. These
difficult airway problems are discussed in the references. Anatomic
Points Note the relative orientation of the structures involved in
endotracheal intubation. In the anatomic position, the orientation
of the horizontally displaced oral cavity is about 90 degrees with
respect to the vertical laryngeal pharynx. The laryngeal inlet
forms the anterior wall of the cranial portion of the laryngeal
pharynx. The rima glottidis is again approximately horizontal, but
the infraglottic cavity and trachea are oblique, coursing from
superoanterior to inferoposterior. With the neck gently flexed and
the atlantooccipital joint extended, the involved pathway has
gentle curves rather than acute angles. Straightening the airway in
this manner also shortens the distance from the teeth to the
trachea. Allow for this when tube length is estimated before
intubation.
- 29. Figure 2-2 Positioning the Patient to Straighten and
Shorten the Airway before Intubation Using Straight and Curved
Laryngoscope Blades (Fig. 2.3) Technical Points Preoxygenate the
patient by bag-and-mask ventilation with 100% oxygen before
attempting intubation. This allows intubation to progress in an
orderly, unhurried fashion. Check all equipment carefully. Verify
that the laryngoscope light works and that the proper size of
endotracheal tube is available, and check the cuff on the
endotracheal tube. Have suction available and working, and have at
hand an assortment of laryngoscope blades, endotracheal tubes, and
a stylet. Use the fingers of your gloved dominant hand to open the
jaws by spreading apart the upper and lower incisors. Hold the
laryngoscope by its handle in your nondominant hand and gently
introduce the blade, sliding it over the tongue toward the
oropharynx. When opening the jaws and inserting the laryngoscope,
be very careful to avoid chipping the teeth or using them as a
fulcrum to lever the laryngoscope blade. Think of
- 30. P.16 the laryngoscope as a lighted tongue blade with a
handle that is used to elevate the tongue, mandible, and epiglottis
to expose the larynx. Two types of laryngoscope blades (straight
and curved) are commonly used. To some extent, personal preference
dictates which blade is used. Many people prefer the curved blade
for routine intubation, using the straight blade only when exposure
is difficult. Insert the curved (MacIntosh) blade to a point just
in front of the epiglottis (Fig. 2.3A). The curve of the blade
tends to follow the curve of the tongue and is advanced downward
until the tip of the blade rests against the hyoepiglottic
ligament. Gentle upward and forward pressure elevates the
epiglottis and reveals the larynx. Be careful not to injure the
teeth. Insert the straight (Miller) blade past the epiglottis (Fig.
2.3B). Elevate the epiglottis by direct pressure to expose the
vocal cords. Careful positioning of the patient to align the airway
before insertion of the blade will help to ensure success. Note
that the view obtained is slightly different because the straight
blade covers and obscures the view of the epiglottis. Figure 2-3
Using Straight and Curved Laryngoscope Blades Anatomic Points Note
that the base of the tongue and the anterior surface of the
epiglottis are apposed.
- 31. P.17 Both have attachments to the hyoid bone (the tongue
via the hyoglossus muscle, the epiglottis via the hyoepiglottic
ligament). Elevating the tongue and mandible will reduce tension on
the hyoid bone and epiglottis and will allow increased mobility of
the epiglottis. Moving the epiglottis anteriorly is accomplished
with a straight blade by applying gentle pressure on the epiglottic
cartilage itself. The curved blade presses on the hyoepiglottic
ligament to pull the epiglottis anteriorly. Visualization of the
Vocal Cords (Fig. 2.4) Technical Points The larynx and vocal cords
should be easily visible (Fig. 2.4). The view of the larynx
obtained is similar to that seen in Fig. 2.1. Although one is now
looking at the larynx directly, rather than using a mirror, the
examiner's position relative to the airway has changed, and thus
the view obtained has the same orientation. If the cords cannot be
visualized, press down on the thyroid cartilage to bring an
anterior larynx into view. Sellick maneuver is used to prevent
regurgitation from the stomach by occluding the esophagus. An
assistant presses down on the cricoid cartilage (if palpable),
using the rigid back wall of this cartilaginous structure to
compress the esophagus against the vertebral column. The assistant
must be instructed not to release the pressure until the cuff of
the endotracheal tube is inflated in the trachea. Anatomic Points
The true vocal cords appear whitish. The more cephalad vestibular
folds (false vocal cords) are pink and are not as prominent. Gentle
downward pressure on the thyroid cartilage will compress the
esophagus and other soft tissues posterior to the larynx, thus
enhancing the alignment of the laryngeal cavity with the passageway
from mouth to vocal cords. Passage of the Endotracheal Tube Through
the Cords (Fig. 2.5) Technical Points If the patient is awake,
anesthetize the throat with topical anesthetic. Introduce the tube
at the angle of the mouth and pass it along the side of the
laryngoscope, usually on the right (for a right-handed operator).
It can thus be introduced without blocking the view of the cords.
Pass the tube under direct vision through the vocal cords (Fig.
2.5A). The endotracheal tube is constructed with a gentle curve,
which aids in passage through the cords (Fig. 2.5B). If a greater
curvature is needed because of a very anterior larynx, use a
stylet. This stiffens the tube but increases the risk for laryngeal
damage if the tube is forced. The tube should pass easily. The
patient may react to passage of the tube into the trachea by
coughing.
- 32. Figure 2-4 Visualization of the Vocal Cords Anatomic Points
Observe the epiglottis, aryepiglottic folds, vestibular folds, and
vocal cords, along with the intervening rima glottidis, during the
preceding steps (Fig. 2.5A, inset). In inserting the tube, guide it
through the rima glottidis to inflict as little trauma as possible
to the laryngeal mucosa. Such trauma can denude regions of the
larynx and elicit involuntary reflexes carried by sensory fibers of
the internal branch of the superior laryngeal nerve cephalad to the
vocal cords and fibers of the recurrent laryngeal nerve inferior to
the vocal cords. Positioning the Tube (Fig. 2.6)
- 33. P.18 P.19 Technical Points Inflate the cuff of the tube and
confirm its placement within the trachea. The cuff should be
inflated until no air leak is detected around it while maintaining
the cuff pressure below 25 mm Hg. This ensures that the cuff
pressure is lower than the tracheal capillary perfusion pressure,
thereby minimizing pressure necrosis of the trachea. The esophagus
lies directly posterior to the trachea; blind passage of the tube,
particularly when the larynx is more anterior than usual, may
result in esophageal intubation. Guard against this by always
passing the tube under direct vision and ascertaining the position
of the tube by confirming that there is easy exchange of air during
respiration as well as the presence of bilateral breath sounds. The
presence of CO2 in the expired gas provides confirmation!use a
!quick look!! CO 2 detector if you are not in the operating room.
This is a disposable plastic device that is placed between the
endotracheal tube and the breathing circuit. An indicator changes
color when CO2 is detected. In the operating room or intensive care
unit, pulse oximetry or end-tidal CO2 measurement can help to
confirm adequacy of ventilatory exchange. Inflate the cuff using
the recommended volume of air for the tube. Overinflation may
rupture the cuff or cause pressure and ischemic damage to the
trachea. The tip of the tube should lie 2.5 cm above the carina to
allow downward migration with increasing neck flexion (Fig. 2.6B).
Confirm the position of the tube by auscultation. Breath sounds
should be heard clearly over both lung fields. If the tube is
inserted too far, it will enter one of the principal bronchi,
usually the right. Overinflation of one lung and collapse of the
contralateral lung will result. When this occurs, deflate the cuff
and reposition the tube. Confirm the position of the tube by
obtaining a chest radiograph. Anatomic Points The blood supply to
the trachea, derived from branches of the inferior thyroid
arteries, is not particularly rich. In addition, the tracheal
cartilages provide a relatively rigid framework. Thus overinflation
of the cuff can easily compromise the blood supply to the mucosa!in
particular, that covering the cartilages.
- 34. Figure 2-5 Passage of the Endotracheal Tube through the
Cords
- 35. Figure 2-6 Positioning the Tube Estimate the distance from
the incisor teeth to the carina in order to ensure that the tip of
the tube is properly placed. The distance from incisors to vocal
cords and then to the carina increases with age. Further, there is
a disproportionate increase in the length of the trachea. The
length of the trachea (cords to carina) essentially triples from
birth to age 65 years, whereas the length of the oropharyngeal
cavity (incisors to vocal cords) essentially doubles. The
approximate length of tube needed can be determined before
intubation by placing the tube alongside the face and neck and
extending it to the sternal angle (of Louis), which approximates
the level of the carina. The tube should be 2 to 3 cm shorter than
this distance. At the carina, the trachea divides into left and
right principal bronchi. The left principal bronchus is smaller in
diameter than the right and takes off at a more acute angle. This
explains why endotracheal tubes, if inserted too far, typically
enter the right principal bronchus. References 1. Applebaum EL,
Bruce DL. Tracheal intubation. Philadelphia: WB Saunders; 1976.
(This monograph describes basic intubation techniques, including
tracheostomy.) 2. Blanc VF, Tremblay NAG. The complications of
tracheal intubation. Anesth
- 36. Analg. 1974;53:202. 3. Dripps RD, Eckenhoff JE, Van Dam LD.
Intubation of the trachea. In: Dripps RD, Eckenhoff JE, Van Dam LD,
eds. Anesthesia: The Principles of Safe Practice. 6th ed.
Philadelphia: WB Saunders; 1982. 4. McGovern FH, Fitz-Hugh GS,
Edgeman LJ. The hazards of endotracheal intubation. Ann
Otolaryngol. 1971;80:556. 5. Orringer MB. Endotracheal intubation
and tracheostomy: indications, techniques, and complications. Surg
Clin North Am. 1980;60:1447. (Provides a clear description of blind
nasotracheal intubation, as well as of other techniques; also
discusses what to do if intubation is not possible after induction
of anesthesia.) 6. Thierbach AR, Lipp MD. Airway management in
trauma patients. Anesth Clin North Am. 1999;17:63!81. (Discusses
options when possible cervical spine injury complicates
management.) 7. Wilson WC, Benumof JL. Pathophysiology, evaluation,
and treatment of the difficult airway. Anesth Clin North Am.
1998;16:29!75.
- 37. P.21 Authors: Scott-Conner, Carol E. H.; Dawson, David L.
Title: Operative Anatomy, 3rd Edition Copyright 2009 Lippincott
Williams & Wilkins > Table of Contents > Section I - The
Head and Neck > The Midline and Structures Approached Through
The Midline > Introduction Introduction The fascial spaces and
anatomic triangles of the neck provide a good orientation to the
complex anatomy of the neck. An understanding of the infrahyoid
deep (or investing) cervical fascia is essential to good surgical
technique in the neck. For simplicity, visualize the cervical
fascia as a set of !tubes within tubes!! (Fig. 1). The outermost
tube, or superficial fascia, which invests all cervical structures,
splits to encompass the sternocleidomastoid muscle, trapezius
muscle, the corresponding motor nerve (cranial nerve XI), and the
strap muscles. This fascial layer attaches posteriorly to the
ligamentum nuchae. In the root of the neck, the fascia is attached
to both the anterior and posterior surfaces of the manubrium. The
intervening suprasternal space (of Burns) contains the lower
portion of the anterior jugular veins and their connecting branch,
the jugular venous arch. Four tubes are located within this
superficial tube. Two of these tubes, the carotid sheaths, are
paired. The carotid sheaths contain the vagus nerve, carotid artery
complex, and internal jugular vein and compose the major
neurovascular bundles of the neck. One of the four tubes, the
prevertebral fascia, encompasses the cervical vertebrae and their
associated muscles, the emerging cervical spinal nerve roots and
branches thereof (including the phrenic nerve), the cervical
portion of the sympathetic chain, and the cervical part of the
subclavian artery. Pretracheal fascia forms the fourth tube. This
fascial tube surrounds the larynx, esophagus, thyroid and
parathyroid glands, and recurrent laryngeal nerve. In the vicinity
of the thyroid gland, the tube splits to invest entirely the
thyroid and parathyroid glands, forming the false capsule of the
thyroid gland. Between the deep surface of the thyroid gland and
the upper two or three tracheal rings, this fascia is strongly
adherent to the gland and trachea, forming the so-called !adherent
zone!! or lateral suspensory ligament (of Berry). The recurrent
laryngeal nerve can pass anterior to, posterior to, or through
(about 25% of cases) this ligament. Parathyroid glands are
typically located within the capsule derived from pretracheal
fascia, but outside the true capsule of the thyroid gland.
- 38. Figure 1
- 39. Figure 2 The superficial neck is divided into triangles
(Fig. 2) for convenience. These triangles are bounded by bony or
muscular fixed landmarks and provide important guides to the
location of nerves and other critical structures. Two major
triangles, both of which are roofed by deep (investing) cervical
fascia on each side of the neck, are based on the location of the
sternocleidomastoid muscle (Fig. 3). Each triangle can be further
subdivided. The anterior triangle is bounded posteriorly by the
sternocleidomastoid muscle, superiorly by the body of the mandible,
and anteriorly by the midline. The posterior triangle is bounded
anteriorly by the sternocleidomastoid muscle, inferiorly by the
clavicle, and posteriorly by the trapezius muscle. The anterior
triangle can be divided into four lesser triangles. The
submandibular triangle lies between the body of the mandible and
the two bellies of the digastric muscle. The carotid triangle is
delimited by the sternocleidomastoid muscle, the superior belly of
the omohyoid muscle, and the posterior belly of the digastric
muscle. The muscular triangle is bounded by the sternocleidomastoid
muscle, the superior belly of the omohyoid muscle, and the midline.
The submental triangle is bounded by the hyoid bone, the midline of
the neck, and the anterior belly of the digastric muscle.
- 40. P.22 The posterior triangle is subdivided into two
triangles. The larger of these is the occipital triangle, which is
bounded by the trapezius muscle, the sternocleidomastoid muscle,
and the inferior belly of the omohyoid muscle. The much smaller
omoclavicular triangle is delimited by the inferior belly of the
omohyoid muscle, the clavicle, and the sternocleidomastoid muscle.
It is quite important to realize that several important structures
of the neck are not, in the strictest sense, located in either the
anterior or posterior triangle or their subdivisions but, rather,
are located deep to the sternocleidomastoid muscle itself. These
structures are typically rendered accessible either by lateral
retraction of the sternocleidomastoid muscle or, immediately
superior to the clavicle, by dissecting in the interval between the
sternal and clavicular heads of the sternocleidomastoid muscle, a
space known as the minor supraclavicular fossa or scalene triangle.
General surgical procedures involving the neck can be divided into
those that are performed through a midline approach and those that
are performed through a lateral incision. Accordingly, the anatomy
of the neck is explored in this section first through structures
approached through the midline (trachea, thyroid, parathyroid) and
then through structures approached laterally (lymph nodes, major
vessels, cervical esophagus). Figure 3 Important structures of the
midline of the neck include the thyroid and parathyroid glands, the
trachea, and the esophagus. In this section, the anatomy of the
trachea (Chapters 3 and 4), thyroid (Chapters 5 and 6), and
parathyroids (Chapter 7) will be developed. Although the esophagus
is a midline structure, it is approached laterally because it
lies
- 41. deep to the trachea. Surgical anatomy of the cervical
esophagus (Chapters 12 and 13), therefore, is included with other
structures approached from the side. References Demetriades D,
Salim A, Brown C, et al. The neck with complex anatomic features
and dense concentration of numerous vital structures. Curr Probl
Surg. 2007;44(1):6!10.
- 42. Authors: Scott-Conner, Carol E. H.; Dawson, David L. Title:
Operative Anatomy, 3rd Edition Copyright 2009 Lippincott Williams
& Wilkins > Table of Contents > Section I - The Head and
Neck > The Midline and Structures Approached Through The Midline
> 3 - Tracheostomy and Cricothyroidotomy 3 Tracheostomy and
Cricothyroidotomy Tracheostomy is necessary when long-term access
to the airway for ventilatory support or respiratory toilet is
required. This chapter describes formal tracheostomy; percutaneous
tracheostomy (Chapter 4) is an alternative in selected patients.
Formal tracheostomy is best performed over a previously placed
endotracheal tube in a fully equipped operating room where adequate
lighting, electrocautery, and suction are available. Percutaneous
tracheostomy may be performed at the bedside, generally in the
intensive care unit, but requires the same attention to airway
control as formal tracheostomy (see Chapter 4). Steps in Procedure
(TRACHEOSTOMY) Position patient, check equipment, test balloon of
tracheostomy tube Identify five midline landmarks Transverse or
vertical incision centered just below cricoid cartilage Divide
tissues in midline Retract or divide thyroid isthmus Expose trachea
and count rings down from cricoid Incision between second and third
ring Pull back endotracheal tube slightly Spread incision and
insert tube Confirm position of tube by passage of suction
catheter; secure tube Steps in Procedure (CRICOTHYROIDOTOMY)
Position patient, check equipment, check balloon of tracheostomy
tube Transverse incision over cricothyroid membrane Control
bleeding by manual pressure Stab into membrane Spread and insert
tube, secure tube, pack wound to control oozing Hallmark Anatomic
Complications
- 43. P.24 Supraglottic tracheostomy Tracheoinnominate artery
fistula (delayed complication) List of Structures Larynx Thyroid
cartilage Cricoid cartilage Median cricothyroid ligament
Cricothyroid artery Trachea Landmarks Mental protuberance Hyoid
bone Laryngeal prominence Manubrium sterni Jugular (suprasternal)
notch Associated Structures Thyroid gland Isthmus Pyramidal lobe
Anterior jugular vein External jugular vein Platysma muscle
Brachiocephalic (innominate) trunk Brachiocephalic (innominate)
vein Jugular venous arch Brachial plexus
- 44. Figure 3-1 Positioning the Patient Tracheostomy may also be
required in an emergency when the patient cannot be intubated in
the normal fashion (e.g., when massive facial trauma or edema
precludes safe intubation). In this situation, cricothyroidotomy
(see Fig. 3.8) can be performed more quickly and more safely than
formal tracheostomy. Positioning the Patient (Fig. 3.1) Technical
Points Slightly hyperextend the neck by placing a small roll under
the patient's shoulders (Fig. 3.1A). If the roll is placed under
the neck instead of the shoulders, a larger roll will be needed and
the head may be elevated as well, thereby preventing the desired
hyperextension. Do not hyperextend the neck in a patient with a
known or suspected cervical spine injury because the resulting
vertebral motion may cause irreversible
- 45. P.25 damage to the spinal cord. Select a tracheostomy tube
appropriate to the size of the patient; for an average-sized adult,
a number 7 or 8 tube will work well. Test the balloon and then
deflate and lubricate it with sterile lubricant. Place the
obturator inside the tube. Be sure that a soft rubber suction
catheter is available on the sterile field for suctioning the
tracheostomy after the tube is inserted. Anatomic Points The
phrenic nerve arises from spinal cord levels C3 to C5, and the
brachial plexus is derived from C5 to T1. Spinal cord damage at or
above C3 will result in death secondary to paralysis of all
respiratory muscles. Damage of the cord at levels involving the
brachial plexus can result in quadriplegia. Hyperextension of the
neck stretches the cord and may compress the cord against a damaged
cervical vertebra; such a maneuver may also result in complete
transection as the cord is caught between broken fragments of
cervical vertebrae. Landmark structures of this region are shown in
Fig. 3.1B. The thyroid gland, often with a pyramidal lobe, overlies
the trachea. The paired sternocleidomastoid muscles are located
well lateral to it. The thyroid cartilage and cricoid cartilage are
easily palpable above the thyroid gland. The hyoid bone can be
palpated above the thyroid cartilage. Identification of Landmarks
(Fig. 3.2) Technical and Anatomic Points Palpate five midline
landmarks, including the mental protuberance, or tip of the chin;
the body of the hyoid bone; the laryngeal prominence of the thyroid
cartilage (Adam's apple); the cricoid cartilage; and the
suprasternal or jugular notch of the manubrium sterni. All of these
constant bony or cartilaginous landmarks should be identified with
certainty to avoid inadvertent supraglottic incision. Repeated
palpation of these readily identifiable midline structures will
help ensure that the dissection remains in the midline.
- 46. Figure 3-2 Identification of Landmarks Skin Incision (Fig.
3.3) Technical Points A vertical incision about midway between the
cricoid cartilage and the jugular notch provides the best exposure
and is preferred in emergency situations. With this incision, there
is less bleeding and less risk for damage to nerves and vessels.
The incision shown is slightly larger than usually required. Do not
hesitate to make a generous incision if exposure is difficult. A
transverse incision, made at the same level, yields a somewhat
better cosmetic result; however, the advantage is marginal because
scarring occurs around the tracheal stoma. Formal tracheostomy is
performed between the second and third tracheal rings.
Cricothyroidotomy is done through the median cricothyroid ligament.
If a transverse incision is used, it should be planned to lie
directly over the appropriate level, confirmed by palpation of the
anatomic landmarks. Anatomic Points The theoretic cosmetic
advantage of a transverse incision is that it follows the direction
of Langer's lines (resulting from the predominant orientation of
dermal collagen bundles and elastic fibers in the skin) and also
parallels the natural wrinkle lines of the area.
- 47. P.26 Figure 3-3 Skin Incision
- 48. Figure 3-4 Dissection down to the Trachea Dissection down
to the Trachea (Fig. 3.4) Technical Points Proceed with sharp and
blunt dissection in the midline, confirming correct placement by
repeated palpation of anatomic landmarks. Anatomic Points The
paired platysma muscles, which should be identified and retracted,
are deficient in the median plane. The superficial veins in this
region (anterior and external jugulars and their tributaries) run
in a predominantly vertical direction deep to the platysma. With
the exception of the jugular venous arch, these superficial veins
do not cross or occupy the median plane. No motor nerves, and only
the terminal branches of sensory nerves, cross or occupy the median
plane. Isthmus of Thyroid Gland (Fig. 3.5) Technical Points The
next important structure to identify is the isthmus of the thyroid
gland. The isthmus may be retracted cephalad or
- 49. P.27 caudad, or divided, to obtain access to the
appropriate segment of the trachea. To facilitate retraction of the
isthmus, spread the tissues with a blunt-tipped hemostat (such as a
small Kelly clamp) in the plane between the thyroid and the
trachea. Then place a vein retractor on the isthmus to retract it
away from the second and third tracheal rings. Decide whether to
divide the isthmus according to the amount of dissection necessary
to expose the second and third tracheal rings and the space
between. Generally, it is possible to achieve this exposure by
retraction. Figure 3-5 Isthmus of Thyroid Gland If it is necessary
to divide the isthmus of the thyroid partially or completely, first
confirm that the plane between the thyroid and trachea has been
developed adequately. Then double-clamp and oversew or
suture-ligate the highly vascular thyroid tissue before proceeding.
Anatomic Points The thyroid begins its development as a
diverticulum in the region of the incipient tongue and migrates
from its site of origin (marked by the foramen cecum) to its
definitive location. Although the large lobes are paratracheal, the
isthmus is in the median plane and typically covers the second and
third tracheal rings. Further, its developmental route is
frequently indicated by the presence of a pyramidal lobe, the
result of !residual!! thyroid tissue being deposited along the path
of descent. This lobe is usually slightly to the left of the
midline, but it may be in the midline or on the
- 50. P.28 right. Exposure of Pretracheal Fascia (Fig. 3.6)
Technical Points Dissect the pretracheal fascia (which invests the
thyroid gland) from the trachea to provide a clear view of the
trachea. To perform a formal tracheostomy, count the rings down
from the cricoid cartilage. Incise and spread the tissue between
the second and third rings (Fig. 3.6A). A simple transverse
incision is generally all that is required; however, some prefer to
make an H-shaped or T-shaped cut. It is rarely necessary to excise
any cartilage. Have an assistant at the head of the table deflate
the cuff of the endotracheal tube and withdraw it slowly until it
is just below the vocal cords but above the tracheal stoma. With
the stoma spread, insert the pretested tracheostomy tube, with the
obturator in place, by pushing it straight in and then downward
(Fig. 3.6B). Push downward only after feeling the tube pop into the
tracheal lumen; otherwise, it is possible to place the tube in the
pretracheal space. Inflate the cuff, have the endotracheal tube
removed, and connect the tracheostomy to the ventilator or to
oxygen. Pass a soft- suction catheter down the tracheostomy tube to
remove blood and mucus from the airway. Free passage of the
catheter into the bronchial tree confirms position of the
tracheostomy tube within the airway. A tracheostomy hook!a small,
sharp, hooked device!may be used to pull the trachea up into the
field and maintain visibility when the incision is deep. However,
care must be taken to avoid puncture of the cuff of the
tracheostomy tube when using the hook. A better method is to place
a 2-0 monofilament suture through the third tracheal cartilage and
use that for retraction. The suture can be left long and brought
out through the skin incision to aid in replacing the tube if it
becomes dislodged. Anatomic Points It is critical that the incision
not be made through the cricoid. This is the only totally
circumferential cartilage in the airway and provides important
stability. Repeated identification of anatomic landmarks and
careful dissection in a bloodless field will prevent such an error
as well as the equally unfortunate circumstance of entering the
airway above the glottis. Tracheobrachiocephalic Artery Fistula
(Fig. 3.7) Technical and Anatomic Points If a tracheostomy is
performed below the level of the fourth ring, the tip of the
tracheostomy tube may erode into the brachiocephalic (innominate)
arterial trunk, which runs obliquely across the thoracic outlet
immediately anterior to the trachea (Fig. 3.7A). This will result
in delayed massive bleeding into the airway. The left
brachiocephalic (innominate) vein often lies in the jugular notch
in its passage from the root of the neck to the superior vena cava
(Fig. 3.7B). A very low incision could injure
- 51. this vessel. Figure 3-6 Exposure of Pretracheal Fascia
Figure 3-7 Tracheobrachiocephalic Artery Fistula
- 52. P.29 Should bleeding from either of these vessels occur,
obtain temporary control by placing a finger in the stoma and
pressing anteriorly or by inflating the balloon of an endotracheal
tube. This will compress the vessel against the undersurface of the
manubrium, allowing time to transport the patient to the operating
room for open or endovascular repair. Definitive management of this
difficult problem is detailed in the surgical references at the end
of this chapter. Cricothyroidotomy (Fig. 3.8) Technical Points
Cricothyroidotomy is performed through the median cricothyroid
ligament, which is the most superficial part of the airway (closest
to the skin) and hence affords the easiest approach during
emergency situations. In a dire emergency, percutaneous needle
cannulation of this ligament may be lifesaving, allowing time for
subsequent, more orderly control of the airway. The landmarks for
this procedure are the thyroid cartilage, the cricoid cartilage,
and the hyoid bone (Fig. 3.8A). To perform an emergency
cricothyroidotomy, first stabilize the larynx with the fingers of
the nondominant hand and palpate the space between the larynx and
cricoid. (Fig. 3.8B). Stab into the median cricothyroid ligament
transversely with a scalpel. Spread the hole with a Kelly clamp and
insert a tracheostomy tube. Be careful to avoid injury to the
cricoid cartilage! Most bleeding will be venous; control it by
direct pressure with the fingers of your nondominant hand until the
tube is in and the patient is successfully ventilated. Then expose
and ligate individual bleeders. If time permits, cricothyroidotomy
may be performed by dissection in a manner similar to that
described for tracheostomy. Visualize the median cricothyroid
ligament and incise it transversely, then spread the tissues and
insert the tracheostomy tube as discussed previously (Fig. 3.8C).
Anatomic Points The cricoid cartilage is the narrowest part of the
airway. Concern about subglottic stenosis limits the application of
this approach. A branch of the superior thyroid artery!the
cricothyroid artery (and its accompanying vein)!runs transversely
across the median cricothyroid ligament. This artery occasionally
has a branch that penetrates the median cricothyroid ligament to
anastomose with the laryngeal arteries. It is typically closer to
the thyroid cartilage than to the cricoid cartilage. Thus, to avoid
injury to these vessels, and to avoid damage to the closely
situated vocal cords, cricothyroidotomy should be performed by
making a transverse incision along the superior border of the
cricoid cartilage, rather than along the inferior border of the
thyroid cartilage.
- 53. Figure 3-8 Cricothyroidotomy Surgical References 1. Chew
JW, Cantrell RW. Tracheostomy: complications and their management.
Arch Otolaryngol. 1972;96:538. (Provides an excellent review of
complications, including tracheoinnominate artery fistula.) 2.
Dulguerov P, Gysin C, Perneger TV, et al. Percutaneous or surgical
tracheostomy: a meta-analysis. Crit Care Med. 1999;27:1617.
(Compares complications as reported in literature.)
- 54. P.30 3. Eliachar I, Zohar S, Golz A, et al. Permanent
tracheostomy. Head Neck Surg. 1984;7:99. (Describes construction of
a permanent stoma.) 4. Gysin C, Dulguerov P, Guyot JP, et al.
Percutaneous versus surgical tracheostomy: a double-blind
randomized trial. Ann Surg. 1999;230:708. (Details complications
associated with both techniques.) 5. Heffner JE, Miller KS.
Tracheostomy in the intensive care unit. I. Indications,
techniques, management. Chest. 1986;90:269. (Offers a good
description of the management of a patient with a tracheostomy.) 6.
Higgins KM, Punthakee X. Meta-analysis comparison of open versus
percutaneous tracheostomy. Laryngoscope. 2007;117:447!454. (Trend
in favor of percutaneous techniques). 7. Orringer MB. Endotracheal
intubation and tracheostomy: indications, techniques, and
complications. Surg Clin North Am. 1980; 60:1447. 8. Van-Hasselt
EJ, Bruining HA. Elective cricothyroidotomy. Intensive Care Med.
1985;11:207. (Provides reviews of clinical experience.) Anatomic
References 1. American Association of Clinical Anatomists,
Educational Affairs Committee. The clinical anatomy of several
invasive procedures. Clin Anat. 1999;12:43. 2. Ger R, Evans JT.
Tracheostomy: an anatomico-clinical review. Clin Anat. 1993;6:337.
3. Salassa JR, Pearson BW, Payne WS. Gross and microscopical blood
supply of the trachea. Ann Thorac Surg. 1977;24:100. Technical
Complications: Management of Tracheoinnominate Artery Fistula
References 1. Allan JS, Wright CD. Tracheoinnominate fistula:
diagnosis and management. Chest Surg Clin N Am. 2003;13:331!341. 2.
Cohen JE, Klimov A, Rajz G, et al. Exsanguinating tracheoinnominate
artery
- 55. fistula repaired with endovascular stent-graft. Surg
Neurol. 2008;69:306!309. 3. Marone EM, Esposito G, Kahlberg A, et
al. Surgical treatment of tracheoinnominate fistula after
stent-graft implantation. J Thorac Cardiovasc Surg.
2007;113:1641!1643. 4. Palchik E, Bakkien AM, Saad N, et al.
endovascular treatment of tracheoinnominate artery fistula: a case
report. Vasc Endovascular Surg. 2007;41:258!261. 5. Ridley RW,
Zwischenberger JB. Tracheoinnominate fistula: surgical management
of an iatrogenic disaster. J Laryngol Otol. 2006;120: 676!680.
- 56. Authors: Scott-Conner, Carol E. H.; Dawson, David L. Title:
Operative Anatomy, 3rd Edition Copyright 2009 Lippincott Williams
& Wilkins > Table of Contents > Section I - The Head and
Neck > The Midline and Structures Approached Through The Midline
> 4 - Percutaneous Dilatational Tracheostomy 4 Percutaneous
Dilatational Tracheostomy Timothy Van Natta G. Patrick Kealey
Percutaneous dilatational tracheostomy is now an accepted operative
technique. There are two slightly different technical approaches to
this procedure, which differ primarily in the use or omission of
bronchoscopic guidance. Both are discussed in this chapter. Steps
in Procedure Position patient, check equipment, including balloon
of tracheostomy tube Bronchoscopic visualization of proximal
trachea (optional) Vertical incision (or horizontal) extending 2 cm
inferiorly from cricoid cartilage Visualize space between second
and third tracheal rings Insert needle, aspirate air, inject
lidocaine Exchange needle for plastic catheter and pass guidewire
(bronchoscopic control) Pass lubricated dilator(s) Using dilator as
obturator, pass lubricated tracheostomy tube and secure Hallmark
Anatomic Complications Bleeding Injury to posterior wall of trachea
Tracheal ring fracture Tracheal stenosis List of Structures Trachea
Cricoid cartilage
- 57. P.32 Percutaneous dilatational tracheostomy is generally
not recommended for achieving emergency airway control or access.
Endotracheal intubation or cricothyrotomy is the most appropriate
emergency technique to achieve adequate airway control and
ventilation. Percutaneous dilatational tracheostomy is a safe and
appropriate technique for use in the intubated patient who requires
elective tracheostomy. It may be done at the bedside in the
intensive care unit. Contraindications to percutaneous dilatational
tracheostomy include the following: 1. Inability to extend the
cervical spine 2. Unstable cervical spine 3. Inability to palpate
anatomic landmarks because of edema, obesity, or anatomic
abnormalities 4. Patients who are not intubated 5. Calcification of
the tracheal rings on chest radiograph 6. Pediatric patients
(younger than 16 years of age) and adults with small airways 7.
Need for emergency airway management (relative) Appropriate
positioning and preparation of the patient are essential to
achieving good operative results. Therefore, in both techniques,
the following preparations must be made. Place the intubated
patient in a supine position. Continuous monitoring should include
electrocardiographic monitoring of heart rate, blood pressure,
pulse oximetry, inspired title volume, and ventilator pressures.
Increase the inspired oxygen fraction to 100% and ensure adequate
ventilation. Because a firm operating surface is necessary, place a
cardiopulmonary resuscitation board under the patient's upper
torso. Extend the cervical spine by placing a rolled towel between
the shoulder blades (see Fig. 4-1A). Prep and drape the anterior
neck with sterile towels. Percutaneous Dilatational Tracheostomy
without Bronchoscopic Guidance (Fig. 4.1) Technical and Anatomic
Points Palpate the anterior neck and identify the landmarks,
including the cricoid cartilage (see also Fig. 4.1B). Infiltrate
the skin and subcutaneous tissues with 1% lidocaine solution with
epinephrine before making the skin incision. Make the skin incision
starting at the inferior edge of the cricoid cartilage and
extending inferiorly 2 cm. Divide the subcutaneous tissues bluntly
with hemostats until the trachea is visualized and its cartilage
rings are palpable. This allows for a clear visual delineation of
tracheal anatomy, including the location of the tracheal midline,
and obviates the need for concomitant bronchoscopy. Achieve
hemostasis with absorbable suture or electrocautery as necessary.
Partially deflate the cuff of the endotracheal tube and slowly
withdraw it until the cuff is palpable at the level of the cricoid
cartilage. Attach a 17-gauge needle with an overlying plastic
catheter to a syringe partially filled with 1% lidocaine solution
with
- 58. epinephrine. Insert this into the trachea between the first
and third cartilage rings under direct vision. Confirm entry into
the trachea by free aspiration of air. Advance the overlying
plastic catheter into the trachea and withdraw the needle. Again
confirm the position of the plastic catheter within the trachea by
aspirating air, and inject 1 mL of 1% lidocaine with epinephrine
into the trachea for local anesthesia and hemostasis. Advance a
1.32 J-tipped guidewire through the catheter into the trachea (Fig.
4.1A) and remove the overlying plastic catheter. Next, place a
dilator guide over the guidewire, followed by a lubricated,
flexible, tapered dilator up to its external 38 French mark (Fig.
4.1B, C). Perform this dilation carefully and without excessive
force. Remove the dilator, leaving the dilator guide and guidewire
in place. Pass a size 6 or 8 cuffed Shiley tracheostomy tube over
the appropriate dilator, which will function as an obturator.
Lubricate the tracheostomy tube and dilator and pass these into the
trachea (Fig. 4.1D). When the tracheostomy tube is seated in its
final position, remove the dilator, dilator guide, and guidewire as
a unit. Inflate the tracheostomy balloon. Leave the endotracheal
tube in place, but disconnect it from the ventilator. Connect the
tracheostomy tube to the ventilator tubing with a flexible adaptor.
Initiate ventilation. Confirm satisfactory oxygenation and minute
ventilation before withdrawing the endotracheal tube. Apply the CO2
detector to ensure proper endotracheal position of the tracheostomy
tube. Secure the tracheostomy tube by four-point fixation using
sutures and a tracheostomy tape. Obtain a portable upright chest
radiograph to determine proper positioning of the tracheostomy tube
and to evaluate for pneumothorax, hemothorax, or significant
atelectasis.
- 59. P.33 Figure 4-1 Percutaneous Dilatational Tracheostomy
without Bronchoscopic Guidance (From Singh RK. Timing and type of
tracheostomy. Probl Gen Surg. 2000;17:101!109, with permission.)
Figure 4-2 Percutaneous Dilatational Tracheostomy with
Bronchoscopic Guidance Percutaneous Dilatational Tracheostomy with
Bronchoscopic Guidance (Fig. 4.2) Technical and Anatomic Points
After preparing the patient as described previously, attach a
bronchoscopy adapter between the endotracheal tube and the
ventilator tubes. Perform a bronchoscopic inspection of the airway.
Withdraw the endotracheal tube to immediately below the vocal
folds. Reinflate the cuff of the endotracheal tube to ensure
adequate ventilation. Bronchoscopic transillumination of the
anterior trachea is a useful guide, but does not absolutely
guarantee an initial midline tracheal puncture. Palpate and define
the cricoid and tracheal rings. Infiltrate the skin and
subcutaneous tissue over the second and third tracheal rings with
1% lidocaine solution with epinephrine. Insert a 17-gauge needle
with an overlying plastic catheter percutaneously between the first
and third tracheal rings into the trachea. Attach the needle to a
syringe partially filled with the lidocaine solution. Confirm the
presence of air by aspirating with a syringe. Use the bronchoscope
to confirm that the needle entry is midline (Fig. 4.2A). Withdraw
the needle, leaving
- 60. P.34 the plastic catheter in place as previously described.
Pass the J wire until bronchoscopic observation, confirming that
the J wire passes toward the carina (Fig. 4.2B). Make a 2-cm
transverse or vertical skin incision 1 cm on either side of the
guidewire. Insert the dilator guide over the guidewire into the
trachea. Dilate the trachea using the tapered flexible dilator up
to its external 38 French mark. In both techniques, perform the
dilatation carefully and without excessive force. Remove the
tapered dilator. Place a size 6 or 8 Shiley tracheostomy tube
snugly over the appropriate dilator. Lubricate the tracheostomy
tube and dilator and pass them over the guidewire and into the
trachea. Use bronchoscopic visualization to confirm that the
tracheostomy tube is within the trachea (Fig. 4.2C). Withdraw the
dilator, dilator guide, and guidewire as a single unit. Insert the
inner cannula of the tracheostomy tube, inflate the cuff of the
tube, and attach the ventilator. Insert the bronchoscope into the
tracheostomy tube to confirm the intratracheal position of the
tracheostomy tube and to inspect for bleeding. Withdraw the oral
endotracheal tube only after confirmation of appropriate
positioning of the tracheostomy tube. Secure the tracheostomy tube
using four-point fixation sutures and the tracheostomy tape. Obtain
a portable upright chest radiograph to evaluate the tracheostomy
position and for the presence of pneumothorax, hemothorax, or
significant atelectasis. The key to successful percutaneous
dilatation tracheostomy is careful surgical technique preceded by
appropriate positioning of an intubated patient. Bronchoscopically
directed guidewire insertion into the trachea ensures anterior
midline placement of the tracheostomy tube and eliminates the
anterior dissection of the neck structures and paratracheal
tissues. References 1. Ciaglia P, Graniero K. Percutaneous
dilatational tracheostomy: results and long- term follow-up. Chest.
1992;101:464!467. 2. Ciaglia P, Firsching R, Syniec C. Elective
percutaneous dilatational tracheostomy: a new simple bedside
procedure, preliminary report. Chest. 1985;87:715!719. 3. Moe KS,
Schmid S, Stoeckli SJ, et al. Percutaneous tracheostomy: a
comprehensive evaluation. Ann Otol Rhinol Laryngol. 1999;108:
384!391. 4. Fernadez L, Norwood S, Roettger R, et al. Bedside
percutaneous tracheostomy with bronchoscopic guidance in critically
ill patients. Arch Surg. 1996;131:129 !132. 5. Rosenbower TJ,
Morris JA Jr, Eddy VA, et al. The long-term complications of
- 61. percutaneous dilatational tracheostomy. Am Surg.
1998;64:82!87. 6. Van Natta TL, Morris JA Jr, Eddy VA, et al.
Elective bedside surgery in critically injured patients is safe and
cost-effective. Ann Surg. 1998;227:618!626. 7. Hinerman R, Alvarez
F, Keller CA. Outcome of bedside percutaneous tracheostomy with
bronchoscopic guidance. Intensive Care Med. 2000;26:1850 !1856. 8.
Higgins KM, Punthakee X. Meta-analysis comparison of open versus
percutaneous tracheostomy. Laryngoscope. 2007;117: 447!454. 9.
Byhahn C, Wilke HJ, Halbig S, et al. Percutaneous tracheostomy:
Ciaglia blue rhino versus the basic Ciaglia technique of
percutaneous dilatational tracheostomy. Anesth Analg. 2000;91:
882!886. 10. Cheng E, Fee Jr WE. Dilatational versus standard
tracheos-tomy: a meta- analysis. Ann Otol Rhinol Laryngol.
2000;109: 803!807. 11. Norwood S, Valina VL, Short K, et al.
Incidence of tracheal stenosis and other late complications after
percutaneous tracheostomy. Ann Surg. 2000;232:233 !241.
- 62. Authors: Scott-Conner, Carol E. H.; Dawson, David L. Title:
Operative Anatomy, 3rd Edition Copyright 2009 Lippincott Williams
& Wilkins > Table of Contents > Section I - The Head and
Neck > The Midline and Structures Approached Through The Midline
> 5 - Thyroglossal Duct Cyst 5 Thyroglossal Duct Cyst In this
section, the anatomy of the upper midline of the neck is explored,
and the embryology of the thyroid gland and associated anomalies is
discussed through the operation of removal of thyroglossal duct
cyst. Thyroglossal duct cysts form along the path of descent of the
thyroid gland. They present as upper midline neck masses. Often,
these cysts become infected and present as abscesses. Incision and
drainage or simple excision of the cyst results in a high
recurrence rate. Complete removal of the cyst and its associated
tract is necessary for cure. Steps in Procedure Position patient:
neck hyperextended, lower face and mouth draped into field
Transverse incision (include sinus tract if present) Retract
sternohyoid muscles and expose cysts Dissect cyst free of
surrounding tissues medially, laterally, cephalad, and caudad Seek
and dissect fibrous tract leading to hyoid bone Trace to hyoid and
resect midportion of hyoid bone in continuity with tract Follow
tract to base of tongue, using pressure on foramen cecum if
necessary; ligate termination Hallmark Anatomic Complication
Recurrence resulting from inadequate dissection List of Structures
Embryologic Structures and Terms Thyroid anlagen Pharyngeal arches
Tuberculum impar (pharyngeal arch I) Copula (pharyngeal arches II
through IV)
- 63. P.36 Thyroglossal duct Adult Structures Tongue Foramen
cecum Hyoid bone Suprahyoid muscles Mylohyoid muscle Geniohyoid
muscle Sternohyoid muscle Genioglossus muscle Hypoglossal nerve
(XII) Mandibular division of trigeminal nerve (V) Mylohyoid nerve
Lingual nerve Thyroid gland Pyramidal lobe Thyroid cartilage
Positioning the Patient and Incising the Skin (Fig. 5.1) Technical
Points Position the patient supine, with the neck hyperextended and
the chin directly anterior. Include the lower face and lips in the
surgical field. (Access to the mouth may facilitate subsequent
dissection.) Make a transverse skin incision over the cyst (Fig.
5.1A). If previous drainage of the cyst has resulted in an external
sinus tract or scar, excise this in transverse elliptical fashion
with the skin incision. Plan the incision to lie parallel to, or
within, the natural skin lines. Elevate flaps in the plane deep to
the platysma muscle to expose the deep cervical fascia and paired
sternohyoid muscles overlying the cyst. Incise this fascia in the
midline.
- 64. Figure 5-1 Positioning the Patient and Incising the
Skin
- 65. P.37 Anatomic Points Thyroid anlagen begin as an epithelial
thickening of endodermal origin during the fourth intrauterine
week. This thickening is located in the floor of pharyngeal arch
II, between the tuberculum impar (pharyngeal arch I) and copula
(arches II through IV) that participate in the formation of the
tongue. The anlage rapidly evaginates, coming into contact with the
aortic sac of the developing heart. Owing to differential growth,
the thyroid migrates from its point of origin, marked by the
foramen cecum of the mature tongue (at the junction of the anterior
two thirds and posterior one third), to its definitive location.
During this migration, the gland is connected to the tongue by the
thyroglossal duct (Fig. 5.1B). The path of migration passes
anterior to the developing hyoid bone, whose paired anlagen, from
pharyngeal arch II, fuse in the ventral midline and also undergo
some rotation. Because of the relationship of the thyroglossal duct
to the developing hyoid bone, the duct can be drawn
posterocranially with respect to the hyoid, be enveloped in hyoid
periosteum or hyoid bone proper, or pass posterior to the hyoid.
Typically, the duct degenerates, leaving a short diverticulum at
the foramen cecum proximally, a longer cord distally that develops
into the pyramidal lobe of the thyroid gland (typically displaced
slightly to the left of the median plane), and an intervening
fibrous cord. If the discontinuous epithelial cells present in the
fibrous remnant differentiate and subsequently assume a secretory
function, a thyroglossal duct cyst results. A thyroglossal duct
cyst should be suspected in any person presenting with a median or
paramedian lump in the neck, especially if the lump is superior to
the level of the cricoid cartilage and if it moves with the
excursion of the hyoid bone during swallowing or tongue protrusion
(Fig. 5.1C). A lingual thyroid, usually the result of maldescent of
the thyroid, has to be considered if the lump is located
intralingually. In this case, preoperative evaluation with a
radioisotope scan is essential because 65% to 75% of patients with
this condition lack other thyroid tissue. Dissection of the Cyst
(Fig. 5.2) Technical Points Retract the paired sternohyoid muscles
laterally to expose the cyst. Carefully dissect the cyst from the
surrounding soft tissues on all sides. Often, the inferior border
can be delineated most easily. Start the dissection here and divide
any attachments to the pyramidal lobe of the thyroid that may be
present (Fig. 5.2A). Search for and identify the tract leading up
to the hyoid bone. This will be palpable as a firm, cordlike
structure passing superiorly and deep in a relatively straight path
to the midportion of the hyoid (Fig. 5.2B). If the cyst is densely
adherent to the hyoid and the tract cannot be identified, simply
proceed to excise the cyst and midportion of the hyoid en bloc.
Anatomic Points The tract typically is to the left of midline,
juxtaposed to the thyroid cartilage. If a pyramidal lobe is
present, the dissection should start at its apex and proceed
superiorly
- 66. P.38 to the body of the hyoid bone. Although the tract
typically ascends posterior to the body of the hyoid and then is
recurved to pass superficial to the anterior surface of the hyoid,
it must be emphasized that the tract can lie within the hyoid
periosteum or within the bone, or it can continue its ascent to the
foramen cecum posterior to the hyoid. Dissection through the Hyoid
to the Base of the Tongue (Fig. 5.3) Technical Points Detach the
mylohyoid and deeper geniohyoid muscles from the hyoid superiorly
and the sternohyoid muscles inferiorly. Divide the hyoid laterally
with a small, heavy scissor. Excise a block of the midportion of
the hyoid bone in continuity with the cyst and its tract (Fig.
5.3A). Continue the dissection proximally. Excise a core of tissue
surrounding the fibrous tract (Fig. 5.3B). Anatomic Points Because
of the variability of the path of the thyroglossal duct with
respect to the hyoid, resect a portion of the body of the hyoid
bone in continuity with soft tissues to ensure that no part of the
duct remains. Figure 5-2 Dissection of the Cyst
- 67. Figure 5-3 Dissection through the Hyoid to the Base of the
Tongue Tract Followed to the Foramen Cecum (Fig. 5.4) Technical
Points Place a second surgical glove (one-half size larger than the
size normally worn) over the glove of your nondominant hand or have
an assistant do this. Insert the index and second finger of this
hand into the mouth and press downward in the vicinity of the
foramen cecum. Then continue the dissection up toward the foramen
cecum, using the hand within the mouth as a guide. Excise the
tract. Do not excise the foramen cecum through the cervical
incision. Suture-ligate the base of the tract just below the
foramen cecum. Check hemostasis in the operated field. If only a
small portion of the hyoid bone has been resected, reapproximate it
with a monofilament nonabsorbable suture. When a large cyst
necessitates removal of a large portion of the hyoid bone, close
the defect by suturing the sternohyoid muscle inferiorly to the
mylohyoid muscle superiorly. Then close the cervical fascia and
skin. Anatomic Points As the tract is followed to the foramen
cecum, the surroundi