WS US Guidance for Head and Neck Chemodenervation Procedures
AAPM&R 2015 Katharine E Alter MD
Zach Bohart MD Elie Elovic MD
Heakyung Kim MD John McGuire MD
Michael Munin MD Jeff Strakowski MD
Faculty/Disclosures • Katharine Alter: Royalties Demos, Honorarium NANA
• John McGuire: speaker fee Allergan • Jeff Strakowski: Royalties Demos Medical Publishing
Handouts
• Handouts are provided online – Review of US guidance techniques for head and
neck BoNT/chemodenervation – Review of US Guidance/Physics * – Review of Evidence comparing various guidance
techniques for BoNT procedures*
• To provide adequate hands on scanning only a brief didactic review will be presented
– Please refer to the online handouts for full handouts
Objectives
• Review of US Basics: • Scanning and Procedural Techniques • Physics: Slides available on Line
• Hands on US Training for Muscle Identification for head and neck chemodenervation procedures
• At the conclusion of the Workshop participants will – Be familiar with ultrasound appearance of key head and
neck muscles/glands – Gain skills in US knobology/transducer handling skills – Be familiar with various US guided procedural techniques
Course Agenda
• Introduction/Review of US Basics & Scanning Techniques/Tips: 15 minutes
• Hands on Scanning: 75 minutes – Demonstration/projection of muscle groups – Followed by practice scanning lead by table
trainers – Table trainers will rotate during the course
Hands On Course Agenda
• US identification of muscles • Neck Muscles/Nerves: 40 minutes
– SCM, Scalenes, Levator Scapulae, Splenius capitus, Trapezius, OCI
• Nerves – Brachial plexus
• Oromandibular Muscles: 15 minutes • Salivary glands: 15 minutes
• Procedural Guidance Techniques – In plane and Out of plane – Demonstration by Faculty – Rotate to this station to practice during down time
Why use US for Chemodenervation Procedures?
• Correctly isolating the target is important for – Efficacy – Minimizing risk/adverse events – Reduce the required effective
dose (potentially) • Traditional localization techniques
have recognized limitations • Comparative studies indicate that
US guidance is more accurate than other techniques
ADVANTAGES OF US GUIDANCE FOR CHEMODENERVATION PROCEDURES
Why you should consider using US for BoNT Injections?
US for BoNT Injections: Advantages • Visualize/isolate target
structures – Quickly – Easily – Accurately
• Less painful – Smaller needles
• Pediatric patients often require no sedation
• Distract patients during procedure
Longituding View SCM
US for BoNT Injections: Advantages
• Improved accuracy when
localization is limited by: – Involuntary muscle activity – Co-contraction – Motor control – Patient cooperation
• US does not require AROM to isolate muscle – Muscle identification is based on
pattern recognition
Upper Motor Neuron Syndromes or Cervical Dystonia
US for BoNT Injections: Advantages Improved accuracy • Localization is limited by
complex or overlapping anatomy
• Very small/large patients – Difficult to estimate
muscle depth
• Identifies safest path to the target – Location – Depth
Transverse View, Lateral Neck
Longitudinal View, Anterior Cervical
US for BoNT Injections: Advantages
• High risk targets – Avoid untargeted
• Muscles • Structures
– Vessels/nerves/organs
• High stakes muscles – SCM – Scalenes – Oromandibular
muscles • Pterygoids
– Subscapularis
Sternocleidomastoid Transverse Scan Out of Plane Injection
Adductors, Transverse Doppler
US for BoNT Injections: Advantages
Focal dystonia • Identify individual muscle
fascicles – Ex: FDS digit 3 vs. 4
• Increased accuracy and speed when identifying muscle fascicles
• Reduced pain – Smaller needles
FDS longitudinal view, mid forearm Short axis view of needle
Longitudinal View, FDS
US for BoNT Injections: Advantages
• Non-muscle targets: – Salivary Glands – Prostate
• Salivary gland: – Correct localization is
critical to reduce the risk of dysphagia
• EMG and E-Stim do not help localization of non-muscle targets
Parotid
Submandibular
US for BoNT Injections: Advantages
• Visualize injectate – Confirms correct site – Provides info on volume of
injectate/distension of muscle
• Reduces risk of over injection at one site
– Minimize spread to adjacent muscles or structures
SCM, Longitudinal View, In Plane Injection VIDEO from Michael C Munin MD
US for Chemodenervation Procedures: Advantages
US + E-Stim for Nerve Blocks Interscalene block • US speeds the localization
of a nerve or nerve branch • Reduces risk of nerve injury • Reduces risk of tissue
damage when injecting phenol
• Reduces risk of injury to organs, vessel penetration
Ultrasound and Procedural Guidance
Disadvantages • Equipment related factors
– Availability – Cost
• Clinician related factors – Lack of experience/training – Limited access to training
specific for chemodenervation – Steep learning curve
Transverse view, proximal forearm
Ultrasound for Chemodenervation: Summary
• Localization techniques – Palpation – EMG – Nerve stimulators – Ultrasound
• All have advantages & disadvantages
• Best Strategy: – Be skilled in multiple techniques – Be aware of
– The limitations of each technique – Evidence supporting/refuting the
accuracy of the various techniques
Comparison of Injection Techniques
Palpation EMG Stimulation Sonography
Accuracy +/- +/- + +++
Practicability + - +/- ++
Availability +/- +/- +/- +
Pain + - +/- +++
Speed +/- - +/- ++
Evaluation +/- - +/- +++
Future research - - - +++
ULTRASOUND BASICS
ULTRASOUND PHYSICS See online handout for review
Ultrasound Equipment Basics:
• Soundwaves are produced by piezoelectric crystals – Cystal arrays are placed
into transducers • Transducers
– Determine the frequency of US waveform ( λ)
– Frequency of US λ determines
• Depth of penetration • Resolution of the image
Ultrasound: Transducer Selection • Select size and shape to match
the clinical application • Size/Shape of transducer
– Linear: • Best for flat surfaces
– Curvilinear: • Best for abdomen/pelvic/GYN
– Hockey stick: • Hand • Small irregular surfaces
US Basics: Transducer Frequency MHz Depth/Penetration Application 3 12-20 cm OB/GYN 5 12-15 cm Deep muscles 7.5 8-10 cm Leg 10 5cm Forearm 12-17 3.5- 2cm Hand, face
Select transducer to match required penetration depth • 12-17 MHz for superficial structure
– Hand, forearm • 3-5 MHz for deep muscles
– Piriformis, iliacus, quadratus lumborum • Most transducers have mixed frequencies
– 3-5, 7-12 etc
Transducer Handling/Orientation
• To correctly orient the transducer on the patient – Look for a manufacturer’s
mark on one end of the transducer
– The marked end = screen left on display
– To confirm this orientation: • Tap the end of the
transducer to confirm the orientation
Notched end
US Basics: View convention
• Top of image is superficial – i.e. skin
• Bottom deeper structures • Transverse view
– Conventions vary • Right always to patient right • Medial always to right
• Longitudinal view – Left proximal – Right distal
Superficial
Deep
Patient R or Medial
Patient Left or Lateral
Transverse view, Anterior Neck
US Basics: View convention
Longitudinal view Convention • Place the transducer on the
patient so that – Proximal = screen left – Distal = screen right
SCM
Distal Proximal
Superficial
Deep
US Basics: Transducer Orientation
Long Axis of Transducer Short Axis of Transducer
Weak scattering from blood and fluids with low impedance to US λ Tissues will appears dark or hypoechoic
US Appearance of a Tissue is Determined by its Acoustic Impedance
“Speckle” from scattering in tissue. L~ λ
Strong echoes from “mirror-like” interfaces will appear bright or hyperechoic
US Basics: Tissue Properties • Muscle
– Hypoechoic background (contractile elements/fascicles)
– Interspersed hyperechoic bands of fibroadipose tissue
• Long axis – CT appears as parallel
hyperechoic lines, less uniform than in tendon
• Short Axis – CT intramuscular tendons,
aponeurosis appear as bands and streaks
Transverse view
Longitudidal view
Transverse view
Holding the transducer
• Grasp the transducer lightly using your – Thumb + index or – Thumb + index+ middle
finger – Do not over grip
• Keep hand in contact with the patient at all times to avoid slipping – Using heel of hand or 4th
and 5th finger
Incorrect : No contact with patient
Correct : Maintaining contact with patient
Anatomic Plane/Transducer Orientation
• Be aware that the – Anatomic plane and
transducer orientation may not always match
• Example – Pronator Quadratus
Pronator Quadratus Longitudinal Muscle Scan Transverse Upper Limb Scan
Pronator Quadratus Transversel Muscle Scan Longitudinal Upper Limb Scan
Scanning Tips/Techniques: Injection Techniques
• In plane/long Axis needle view: – Keep needle parallel to
transducer – Insert needle at flat
angle – Poor needle visualization
• Oblique position • Steep angle needle
Scanning Tips/Techniques: Injection Techniques
• Out of plane/short axis needle view: – Keep needle tip under
US beam • If needle tip is outside of
US beam, visualization is lost
• May be in untargeted structure or muscle
– Walk down technique • Follow movement of
needle tip passing through tissues planes to target
• Real time injection • Whatever technique is
used: – Keep needle within the
ultrasound beam – If needle tip is outside of
the narrow US beam visualization is lost
• Tip may not be in target structure
Interventional MS Ultrasound: Clinical Pearls
Interventional MS Ultrasound: Pearls of Wisdom
• Larger needles are easier to see than small needles – Larger needles hurt more – 27g needles are easily seen particularly in an in plane view – Non-insulated needles are visualized better than insulated. Etched
Needles are also available • Small amount of air (.2-.3 ml) helps define needle location • Agitate injectate: increases reflection from bubbles
– Agitating may denature the toxin • Billing: In the USA, to charge/bill for US, a picture or cine-
loop must be saved to document the procedure • Billing Code: 76942: Ultrasound for Needle guidance, aspiration
US Muscle identification
• Identification of muscles is based on pattern recognition of – Contour lines – Adjacent structures
• Bones • Vessels • Other muscles
– Real-time • Use AROM/PROM to
assist muscle identification
Pronator teres FCR
US Scanning Demonstration
• Transducer handling/manipulation • Scanning limbs/structures • Injection Techniques
– In plane – Out of plane
Hands On Session Hands On Ultrasound Session: • 6 Ultrasound Stations
• Wrap Up/Final questions – Panel
• Demonstration/Scanning • Neck
– SCM – Scalenes – Levator Scapulae – Splenius Capitus – trapezius
• Oromandibular – Masseter, Ptyergoids
• Salivary gland – Parotid, Submandibular
Hands On Course Agenda
• Demonstration/projection of muscle groups • Following the demonstration each group will
practice scanning – The following key muscles will be demonstrated
• Pectoralis Major/Subscapularis • Biceps/Brachialis • FCR/Pronator Teres/FDS • SCM/Scalenes • Parotid/Submandibular • Procedural Guidance Techniques
Neck Muscles
Pages From Ultrasound Guided Chemodenervation Procedures, Text and Atlas, Demos Medical Publishing, Used with Permission
Neck Muscles
Pages From Ultrasound Guided Chemodenervation Procedures, Text and Atlas, Demos Medical Publishing, Used with Permission
Neck Muscles
Levator Scapulae Trapezius
Oromandibular Muscles
Masseter Medial/Lateral Ptyergoid
Salivary Gland
Pages From Ultrasound Guided Chemodenervation Procedures, Text and Atlas, Demos Medical Publishing, Used with Permission
