PEER-REVIEW REPORTS

Gasket Seal Closure for Extended Endonasal Endoscopic Skull Base Surgery: Efficacy in

a Large Case Series

Victor Garcia-Navarro1, Vijay K. Anand2, Theodore H. Schwartz1-3

-OBJECTIVE: To assess long-term efficacy of the gasket seal, a method forwatertight closure of the cranial base using autologous fascia lata held in placeby a rigid buttress, in a large case series.

-METHODS: A prospectively acquired database of all endonasal endoscopicsurgeries performed over a 5-year period at Weill Cornell Medical Collegestarting in September 2005 was reviewed.

-RESULTS: The gasket seal was used in 46 consecutive patients. Mean age was53 years (range 7 83 years). All patients had extensive intracranial disease witha significant intraoperative cerebrospinal fluid (CSF) leak. Pathology includedcraniopharyngioma (39.1%), meningioma (23.9%), and pituitary adenoma (17.4%).After a mean follow-up of 28 months (range 3 63 months), two (4.3%) patients hada postoperative CSF leak. Excluding the patients with adenomas, the CSF leak ratewas 5.2% (2 of 38 patients). One leakwas controlledwith reoperation, and the otherwas stopped with a lumbar drain (LD). The significance of pathology, type ofapproach, exposure of the ventricular system, use of fat graft, use of nasoseptal(NS) flap, and use of lumbar drain (LD) was examined, and none of these weresignificant predictors of postoperative CSF leak.

-CONCLUSIONS: Gasket seal closure is a reliable long-term effective methodfor achieving watertight closure of the cranial base. It can be used in associ-ation with an intracranial fat graft, NS flap, LD, and tissue sealants. In thisseries, none of these other factors were significant predictors of postoperativeCSF leak.

Key words- CSF leak- Endoscopic- Extended endonasal approach- Gasket seal- Minimally invasive- Nasoseptal flap- Pituitary- Skull base

Abbreviations and AcronymsCSF: Cerebrospinal fluidLD: Lumbar drainNS: Nasoseptal

From the Departments of 1Neurosurgery,2Otolaryngology, and 3Neurology and

Neuroscience, Weill Cornell Medical College, New YorkPresbyterian Hospital, New York, New York, USA

To whom correspondence should be addressed:Theodore H. Schwartz, M.D[E mail: schwarh@med.cornell.edu]

Citation: World Neurosurg. (2013) 80, 5:563 568.http://dx.doi.org/10.1016/j.wneu.2011.08.034

Journal homepage: www.WORLDNEUROSURGERY.org

Available online: www.sciencedirect.com

1878 8750/$ see front matter ª 2013 Elsevier Inc.

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All rights reserved.

INTRODUCTION

The use of extended endonasal approachesin the management of ventral skull base le-sions is gaining popularity asmore surgeonsbecome comfortable with the technique(4, 29, 43). The most relevant benefits arethat this approach obviates the need forbrain retraction, provides a direct corridorto the pathology that does not cross overany cranial nerves or vascular structures,decreases the hospital stay, and potentiallyimproves the quality of life of patientscomparedwith the transcranial or endonasalmicroscopic approaches (4, 8). Reconstruc-tion of the skull base defect after endonasalskull base surgery has been a challenge (3,11, 19, 25, 34, 38, 42, 49). Inadequate closurecan be associated with cerebrospinal fluid(CSF) leak, meningitis, pneumocephalus,and death, necessitating a reliable methodfor achieving long-term skull base closure

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(47). Early series reported postoperative leakrates of 5%e50% (1, 4, 6-8, 10, 14, 29, 30, 32,33, 35). Multiple techniques have beenintroduced to reconstruct the ventral cranialbase, including synthetic materials, freetissue grafts, local pedicled grafts, andmicrovascular free flaps, alone or in combi-nation, which have been successful inreducing the rate of postoperative CSF leakconsiderably (2, 5, 13, 22, 23, 29, 30, 33, 35,36, 41, 44, 50). However, success rates varywidely based on pathology, size of thecranial base defect, experience, and tech-nique (2, 18, 28, 33, 36, 40, 50). Likewise,case series often include pituitary adeno-mas, which are generally extra-arachnoidaltumors with a lower rate of postoperativeCSF leak rate. A few years ago, our groupintroduced the gasket seal method and re-ported a small series of patients with limitedfollow-up and a 0% leak rate (33). The

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technique has also been described by otherswith similar success. We describe here ourexperience using this technique in a largergroup of patients with longer follow-up andprovide data for nonadenomatous intracra-nial surgery.

METHODS

We reviewed a prospectively acquired data-base of all endonasal endoscopic surgeriesperformed at Weill Cornell Medical Collegeby the senior authors (T.H.S. and V.K.A.)between September 2005 and September2010. Cases in which the gasket seal closurewas used were noted as well as concomitantuse of a fat graft, lumbar drain (LD), liquidsealant, or nasoseptal (NS) flap. Overtime, our protocol changed slightly, andwe introduced the NS flap as a last layer inthe latter part of our series. We carefully

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Figure 1. (A) Gasket seal closure using MEDPOR to buttress anonlay inlay fascia lata graft. (B) Onlay of a vascularized nasoseptal flap.

(C) A final layer of DuraSeal holds the flap in place.

Table 1. Efficacy of Gasket SealClosure in a Large Case Series

Pathology Cases GTRPOLeak

Craniopharyngioma 18 66%* 1

Meningioma 11 72%

PituitaryMacroadenoma

8 95%

Hemangioblastoma 2 50%

Xanthogranuloma 2 100%

Rathke cleft cyst 1 100% 1

Germinoma 1 100%

Carcinoma 1 0%

Chordoma 1 100%

Suprasellar Dermoid 1 100%

Ethmoid Encephalocele 1 NA

Total 46 2 (4.3%)

GTR, gross total resection; NA, not available; PO,postoperative.

*GTR was attempted in 15 patients and achieved in 12of 15 (80%).

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reviewed the records to ensure that in allcases there was a large CSF leak, grade 3(large diaphragmatic or dural defect), iden-tified during surgery (12). We also carefullyseparated patients who had pituitaryadenomas, which have an extra-arachnoidalorigin and a lower rate of postoperative CSFleak, from patients with pathology with anintra-arachnoidal origin and higher risk ofpostoperative CSF leak. Postoperative CSFleak rateswere identifiedandcorrelatedwithpathology, approach, and closure tech-nique. Institutional review board approvalwas obtained for this study.

Surgical TechniqueThe gasket seal closure has been describedin detail elsewhere (33). Briefly, for thegasket seal to be effective, the defect in theskull base must be surrounded by a rim ofbone. The vertical and horizontal diame-ters of this defect are measured either witha ruler or with a cottonoid. Both fat andfascia lata grafts are harvested from thethigh. We tend to use the left thigh so thatharvesting does not disrupt the endonasalprocedure, which is performed primarilyfrom the patient’s right side. If a largeintracranial cavity remains after removingthe lesion, fat is used to obliterate thisdead space to prevent pooling of CSF. Ifthe third ventricle is widely open, a fatgraft is not used to avoid the graft fallinginto the floor of the third ventricle andcausing obstructive hydrocephalus. Thefascia lata graft is fashioned in the samedimensions of the cranial base defect butwith an additional 2 cm of diameter so asto extend 1 cm beyond the edge of thecranial base defect circumferentially. Thefascia lata graft is placed over the defect. Apiece of vomer, or MEDPOR (Porex Corp,

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Newnan, Georgia, USA), is cut to be thesame size as the defect. This rigid buttressis placed over the fascia lata graft andcountersunk into the defect so that theedges of the buttress are wedged justbeyond the bony edges of the defect,holding it in place. The center of the fascialata graft is intracranial, whereas the edgesremain in the sinus cavity, similar toa cauliflower leaf (Figure 1). The fascialata, which is circumferentially wedgedbetween the bony edge of the cranialdefect and the graft, creates a watertightgasket seal.

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In the beginning of our series, wecovered the gasket seal directly with Dura-Seal (Covidien, Mansfield, Massachusetts,USA); we now cover it with a vascularizedNS flap (36) and then cover the flap withDuraSeal to hold it in place. It is crucial thatthe margins of the NS flap extend beyondthe margins of the fascia lata graft; other-wise, the flap is not in direct oppositionwith the bone of the skull base. In manycases, an LD was placed at the beginning ofthe operation, used to introduce intrathecalfluorescein (Akorn Inc, Buffalo Grove, Illi-nois, USA) according to our publishedprotocol (39) and for intermittent drainageafter surgery. Our protocol involves intra-thecal injection (0.25mL of 10%fluoresceinmixed with 10 mL of CSF) after premed-icationwith 50mg of diphenhydramine and10 mg of dexamethasone.At the end of the operation, no nasal

packing is used, but a small folded pieceof Telfa (Santee, California, USA) is placedin each nostril for 24 hours to reducepostsurgical nasal drainage. Patients areseen by the otolaryngologist for nasalhygiene on postoperative day 10 and at 6weeks, 12 weeks, and 24 weeks.

RESULTS

The gasket seal closure was used in 46patients. Themean agewas 53.3 years (range7e83 years). Themost common pathologieswere craniopharyngioma (39.1%), menin-gioma (23.9%), and pituitary adenoma(17.4%) Other lesions included heman-gioma, hemangioblastoma, germinoma,squamous cell carcinoma, intradural chor-doma, dermoid, Rathke cleft cyst, andencephalocele. All lesions had a significantintracranial extension, and surgery resulted

dx.doi.org/10.1016/j.wneu.2011.08.034

Figure 2. Steps in gasket seal closure. (A)The defect is shown in the anterior cranialbase after a transplanum, transtuberculumapproach. (B) The fascia lata is centeredover the defect. (C) A buttress is wedged inplace. (D) The redundant fascia lata isdraped around an onlay of a vascularizednasoseptal flap. (E) A final layer of DuraSealholds the flap in place.

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in a large cranial base defect with a signifi-cant CSF leak (Table 1).The approaches used were trans-

tuberculum, transplanum (86.2%); trans-tuberculum, transplanum, transclival (6.5%);transtuberculum, transplanum, transeth-moidal, transcribriform (2.2%); transeth-moidal, transfovea ethmoidalis (2.2%); andtransclival (2.2%). The details of theseapproaches have been described elsewhere(16, 17, 20, 21, 31, 43, 46).An LD was placed intraoperatively before

resection in 31 cases (67%) (12, 44, 45). Theremainingpatientshadpreoperative lumbarpuncture only for administration of intra-thecalfluorescein. In patients whohad LDs,the LDs were left in place for 24e48 hoursand opened intermittently at a rate of 5 mL/hr. Fat grafts were placed intracranially in 31patients. AnNS flapwas used in 21 patients.All patients had DuraSeal placed either overthegasket seal or over theNSflap if the latterwas used but never between the twobecausethis would prevent theflap fromadhering tothe skull base (Figures 1 and 2).After a mean follow-up of 28.5 months

(range 3e63 months), there were 2 (4.3%)postoperative CSF leaks in 46 patients.Excluding the pituitary tumors, the CSF

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leak rate was 5.2% (2 of 38 patients). For21 cases in which the gasket seal wascombined with the NS flap, the leak ratewas 4.7% (1 of 21 cases). This one CSFleak occurred in a patient with a giantcraniopharyngioma in which a trans-planum, transtuberculum approach wascombined with a transclival approach.Based on the configuration of the defect,which involved both the planum and theclivus and contained a 90-degree angle inthe defect, we were unable to attain anadequate gasket seal (Figure 3). Althoughan NS flap was also used in this patient,the leak was substantial and requiredreoperation and suturing of the edge ofthe fascia lata to the dura. This patient didnot have an adequate gasket seal, so thiswas a failure of a poorly performed gasketseal. The second patient had a smallRathke cleft cyst. Neither an LD nor an NSflap was placed intraoperatively. A smallleak was noted postoperatively, whichstopped with 3 days of intermittent lumbardrainage. The reoperative rate for CSF leakwas only 2.2% (1 of 46).There was no significant relationship

between the pathology; approach; directcommunication with the third ventricle;

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or use of fat graft,NS flap, or LDwith postoperativeCSF leak rate(Table 2). How-ever, the inabilityto perform a suit-able gasket sealadequately basedon the mor-phology of thedefect in the pa-tient with a giantcraniopharyngiomaindicates that thegasket seal may besuitable only fordefects that do notcontain an angledturn (Figure 3).Because the gasketuses a rigid but-tress that existsin only a singleplane, alternativetechniques are re-quired when the

defect has a dual-plane morphology.

These techniques include direct suturing ofgraft material to the dura and possiblyplacement of a temporary balloon in thenasopharynx for support.

DISCUSSION

The relatively high risk of postoperativeCSF leak—50% in some series—has beenthe primary limitation of endonasal cranialbase surgical approaches (8, 10, 15, 30).Over the past decade, specific attentionhas been paid to this problem andadvances in reconstructive techniqueshave led to dramatic improvements inrates of postoperative CSF leak so that thegoal of 5% is now achievable in mostexperienced groups (Table 2). The mostimportant aims of skull base reconstruc-tion are (a) to support the brain and orbit,(b) to separate the central nervous systemfrom the aerodigestive tract, (c) to providelining for the nasal cavities, (d) to forma watertight dural seal, (e) to preventairflow into the intracranial space, and (f)to provide a good cosmetic outcome (5, 18,28). The ideal graft materials should be(a) available in adequate quantity; (b)biocompatible with minimal chance of

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Figure 3. Uses and limitations of the gasket seal. (A and B) The rigidbuttress of the gasket is useful in a single plane. (C) When there is a large

defect in two geometric planes, the gasket is not ideal.

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resorption, rejection, or infection; (c)easily harvested with minimal morbidity;(d) associated with minimal imaginginterference; (e) inexpensive; and (f) free ofpotential disease transmission (5). Withthis in mind, we developed the gasket sealclosure; in a preliminary series of 10patients, we reported a 0% CSF leak rate(33). In the present larger series withlonger follow-up, the rate of CSF leak isslightly higher but in the acceptable rangeof approximately 5% even for non-adenomatous intracranial pathology.The philosophy behind the gasket seal

was to provide an autologous graft thatwould be placed in direct contact with thepatient’s dura and held firmly in place tofacilitate vascularization or fibrosis toensure a long-term seal. The concept hasalso been used by other groups and re-ported in limited series (7). The graft mustbe held rigidly in place—hence thebuttress, which avoids the need for aninflated intranasal balloon with its inherentrisks of overinflation, local infection,sinusitis, and postoperative distress to thepatient. However, if the buttress falls awayfrom the skull base, the gasket seal fails.Likewise, as we learned in one of our fail-ures, if the defect traverses two separate

Table 2. Gasket Seal Closure Performed with

Gasket Alone Gasket D LD Gas

Cases 12 13

Leaks 1

LD, lumbar drain; NS, nasoseptal.

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geometric planes, the gasket may failbecause the buttress is not curved and existsin only one plane in space. In this situation,use of a sutured graft covered with an NSflap and a balloon for buttressing may beindicated.The vascular pedicled NS flap, described

by Hadad et al. (22), was useful in reducingthe rate of postoperative CSF leak in onegroup from 33% to 4% (25, 29, 49). Thesedata motivated us to combine the NS flapwith the gasket seal to increase efficacy andto provide a long-term vascular supply andto facilitate mucosal ingrowth. Likewise,we provide a brief period of intermittentlumbar drainage. Although this lattertechnique is avoided bymany practitioners,we have found it extremely useful. Asshown more recently in a study of tissuesealants in endonasal cranial base surgery,sealant strength increases dramaticallybetween 12 and 24 hours (37). Lumbardrainage during this critical early post-operative period provides the necessarytime to allow the sealant to attain itsmaximum strengthwithout undue pressureon the graft. For this reason, the LD is oftenremoved after only 24 hours, which alsopermits early mobilization of the patientreducing the morbidity.

Lumbar Drain or Nasoseptal Flap or Both

ket D NS Flap Gasket D NS Flap D LD

2 19

1

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Although the LD andNSflap do not seemto be significant predictors of postoperativeCSF leak, our adoption of an LD arose fromexperience with patients who had smallpostoperative CSF leaks that stopped withlumbar drainage (20). We hypothesizedthat if the LD had been used immediatelyafter surgery, the leak would not haveoccurred in the first place. Althoughpneumocephalus is a theoretical risk oflumbar drainage, if a solid multilayerclosure is achieved and is covered by an NSflap and DuraSeal, pneumocephalus is arare occurrence unless there is a very largeleak. Althoughwe cannot prove that lumbardrainage made a difference in this series,we presume that we prevented some leaksthat would otherwise have occurred.Likewise, the NS flap did not seem to

make a difference in our series, which raisesthe question of its utility, but this statementcannot be completely supported by only thisstudy. However, the vascularized flap leadsto more rapid epithelialization of the sphe-noid sinus, which increases the long-termsecurity of the closure and increases func-tionality of the sphenoid mucosa. Likewise,in others’ hands, the vascularized flapreduces the incidence of CSF leak and solikely adds an additional level of security tothe closure (Table 3) (9, 29). We place LDsand place a vascularized flap in manypatients who may not require these proce-dures, but their addition likely prevents a fewCSF leaks. However, because postoperativemeningitis correlates with the occurrence ofpostoperative CSF leaks, it seems justified toavoid this potentially devastating complica-tion (48). At the present time, the rate of

dx.doi.org/10.1016/j.wneu.2011.08.034

Table 3. Published Cerebrospinal Fluid Leak Rates After Endoscopic Skull Base Surgery with and without Inclusion of PituitaryAdenomas

Author, Year (Reference)Number ofPatients Reconstruction Materials

Follow-up(months) LD

Adenoma(%)

CSFLeak (%)

CSF Leak, NoAdenomas

Frank et al., 1998e2005 (15) 10 Fat þ fascia, mucoperiosteum þ bone 37 ND 0 30 30% (3/10)

de Divitiis et al., 2004e2005 (7) 20 Dural substitute þ Lactosorb copolymer þmucoperichondrium þ fibrin glue þ Foley balloon

12.7 3 35 5 7.6% (1/13)

Cavallo et al., 2004e2006 (5) 21 Human pericardium þ LactoSorb copolymer þ collagensponge þ fibrin glue þ Foley balloon

ND 1 23 9.5 12.5% (2/16)

Leng et al., 2005e2007 (33) 10 Fat þ gasket þ DuraSeal 12 10 0 0 0% (0/10)

Dehdashti et al., 2005e2007 (8) 22 Duragen dural graft matrix þ fascia intradural andfascia extradural þ fibrin glue þ Foley balloon

ND ND 13 18 21% (4/19)

Kassam et al., 2006e2007 (29) 75 Collagen matrix þ fat or fascia þNS flap þ fibrin glue þFoley balloon

>2 ND 28 10.6 11.1% (6/54)

Harvey et al., 2007e2008 (23) 30 Fat þ Fascia þ Duragen dural graft matrix þ pedicledmucosal flap þ fibril glue þ Gelfoam absorbablesponge þ balloon

6 ND 26 3.3 0% (0/22)

Luginbuhl et al., 2007e2009 (35) 20 Button (fascia lata) þ NS flap þ fibrin glue ND 8 0 10 10% (2/20)

Present series 46 Fat þ gasket þ NS flap þ DuraSeal 28 31 17 4.3 5.2% (2/38)

LD, lumbar drain; ND, no data; NS: nasoseptal flap.

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postoperative CSF leak after endonasal skullbase surgery is comparable to rates of CSFleak after standard transsphenoidal or opentranscranial skull base approaches (5, 12, 24,26-28).

CONCLUSIONS

The gasket seal technique for closing thecranial base after extended endonasalendoscopic approaches is an effectivemethod for achieving CSF leak rates ofapproximately 5%. Combining thisapproach with brief postoperative lumbardrainage, NS flaps, and DuraSeal mayprovide additional security. Factors thatmay limit the utility of this technique includethe absence of a solid bone surroundingthe cranial base defect and a defect thatspans two geometric planes. These situa-tions may require a more lengthy process,such as direct suturing of graft material andinflated balloons to support the closure.

ACKNOWLEDGMENTS

We thank Gabriel Castillo Velazquez,M.D., for his artistic contributions.

REFERENCES

1. Arbolay OL, Gonzalez JG, Gonzalez RH,Galvez YH: Extended endoscopic endonasal

WORLD NEUROSURGERY 80 [5]: 563 568

approach to the skull base. Minim Invasive Neu-rosurg 52:114-1148, 2009.

2. Cappabianca P, Cavallo LM, Mariniello G, deDivitiis O, Romero AD, de Divitiis E: Easy sellarreconstruction in endoscopic endonasal trans-sphenoidal surgery with polyester-silicone duralsubstitute and fibrin glue: technical note. Neuro-surgery 49:473-475, 2001.

3. Cappabianca P, Esposito F, Magro F, Cavallo LM,Solari D, Stella L, de Divitiis O: Natura abhorreta vacuo use of fibrin glue as a filler and sealantin neurosurgical “dead spaces”: technical note.Acta Neurochir (Wien) 152:897-904, 2010.

4. Cavallo LM, de Divitiis O, Aydin S, Messina A,Esposito F, Iaconetta G, Talat K, Cappabianca P,Tschabitscher M: Extended endoscopic endonasaltranssphenoidal approach to the suprasellar area:anatomic considerations part 1. Neurosurgery 61(3 Suppl):24-33, 2007.

5. Cavallo LM, Messina A, Esposito F, de Divitiis O,Dal Fabbro M, de Divitiis E, Cappabianca P: Skullbase reconstruction in the extended endoscopictranssphenoidal approach for suprasellar lesions.J Neurosurg 107:713-720, 2007.

6. Couldwell WT, Weiss MH, Rabb C, Liu JK,Apfelbaum RI, Fukushima T: Variations on thestandard transsphenoidal approach to the sellarregion, with emphasis on the extended approachesand parasellar approaches: surgical experience in105 cases. Neurosurgery 55:539-547, 2004.

7. de Divitiis E, Cavallo LM, Cappabianca P,Esposito F: Extended endoscopic endonasal trans-sphenoidal approach for the removal of suprasellartumors: part 2. Neurosurgery 60:46-58, 2007.

, NOVEMBER 2013 ww

8. Dehdashti AR, Ganna A, Witterick I, Gentili F:Expanded endoscopic endonasal approach foranterior cranial base and suprasellar lesions:indications and limitations. Neurosurgery 64:677-687, 2009.

9. Di Maio S, Cavallo LM, Esposito F, Stagno V,Corriero OV, Cappabianca P: Extended endo-scopic endonasal approach for selected pituitaryadenomas: early experience. J Neurosurg 114:345-353, 2011.

10. Dusick JR, Esposito F, Kelly DF, Cohan P,DeSalles A, Becker DP, Martin NA: The extendeddirect endonasal transsphenoidal approach fornonadenomatous suprasellar tumors. J Neurosurg102:832-841, 2005.

11. Dusick JR, Mattozo CA, Esposito F, Kelly DF:BioGlue for prevention of postoperative cerebro-spinal fluid leaks in transsphenoidal surgery:a case series. Surg Neurol 66:371-376, 2006.

12. Esposito F, Dusick JR, Fatemi N, Kelly DF: Gradedrepair of cranial base defects and cerebrospinalfluid leaks in transsphenoidal surgery. Neurosur-gery 60(4 Suppl 2):295-303, 2007.

13. Fortes FS, Carrau RL, Snyderman CH, Kassam A,Prevedello D, Vescan A, Mintz A, Gardner P:Transpterygoid transposition of a temporoparietalfascia flap: a new method for skull base recon-struction after endoscopic expanded endonasalapproaches. Laryngoscope 117:970-976, 2007.

14. Frank G, Pasquini E, Doglietto F, Mazzatenta D,Sciarretta V, Farneti G, Calbucci F: The endo-scopic extended transsphenoidal approach forcraniopharyngiomas. Neurosurgery 59(1 Suppl 1):ONS75-ONS83, 2006.

w.WORLDNEUROSURGERY.org 567

TUMOR

PEER-REVIEW REPORTS

VICTOR GARCIA-NAVARRO ET AL. GASKET SEAL CLOSURE FOR SKULL BASE SURGERY

15. Frank G, Sciarretta V, Calbucci F, Farneti G,Mazzatenta D, Pasquini E: The endoscopic trans-nasal transsphenoidal approach for the treatmentof cranial base chordomas and chondrosarcomas.Neurosurgery 59(1 Suppl 1):ONS50-ONS57, 2006.

16. Fraser JF, Nyquist GG, Moore N, Anand VK,Schwartz TH: Endoscopic endonasal transclivalresection of chordomas: operative technique,clinical outcome, and review of the literature.J Neurosurg 112:1061-1069, 2010.

17. Fraser JF, Nyquist GG, Moore N, Anand VK,Schwartz TH: Endoscopic endonasal minimalaccess approach to the clivus: case seriesand technical nuances. Neurosurgery 67(3 SupplOperative):150-158, 2010.

18. Gil Z, Abergel A, Leider-Trejo L, Khafif A,Margalit N, Amir A, Gur E, Fliss DM:A comprehensive algorithm for anterior skull basereconstruction after oncological resections. SkullBase 17:25-37, 2007.

19. Goel A, Muzumdar DP: Reconstruction of thesella floor using vascularized pedicled mucosalflap. Br J Neurosurg 17:553-555, 2003.

20. Greenfield JP, Anand VK, Kacker A, Seibert MJ,Singh A, Brown SM, Schwartz TH: Endoscopicendonasal transethmoidal transcribriform trans-fovea ethmoidalis approach to the anterior cranialfossaandskull base.Neurosurgery 66:883-892, 2010.

21. Greenfield JP, Leng LZ, Chaudhry U, Brown S,Anand VK, Souweidane MM, Schwartz TH:Combined simultaneous endoscopic trans-sphenoidal and endoscopic transventricular resec-tion of a giant pituitary macroadenoma. MinimInvasive Neurosurg 51:306-309, 2008.

22. Hadad G, Bassagasteguy L, Carrau RL, Mataza JC,Kassam A, Snyderman CH, Mintz A: A novelreconstructive technique after endoscopicexpanded endonasal approaches: vascular pediclenasoseptal flap. Laryngoscope 116:1882-1886,2006.

23. Harvey RJ, Nogueira JF, Schlosser RJ, Patel SJ,Vellutini E, Stamm AC: Closure of large skull basedefects after endoscopic transnasal craniotomy.J Neurosurg 111:371-379, 2009.

24. Hasegawa M, Torii S, Fukuta K, Saito K: Recon-struction of the anterior cranial base with thegaleal frontalis myofascial flap and the vascular-ized outer table calvarial bone graft. Neurosurgery36:725-729, 1995.

25. Horiguchi K, Murai H, Hasegawa Y, Hanazawa T,Yamakami I, Saeki N: Endoscopic endonasal skullbase reconstruction using a nasal septal flap:surgical results and comparison with previousreconstructions. Neurosurg Rev 33:235-241, 2010.

26. Jane JA, Vance ML: The transsphenoidal trans-tuberculum sellae approach for suprasellar menin-giomas. In: 2004 AANS Annual Meeting. May 1-6,Orlando, Florida. Park Ridge, IL: American Associ-ation of Neurological Surgeons; 2004 (Abstract).

27. Jane JA Jr, Kiehna E, Payne SC, Early SV,Laws ER Jr: Early outcomes of endoscopic

568 www.SCIENCEDIRECT.com

transsphenoidal surgery for adult craniophar-yngiomas. Neurosurg Focus 28:E9, 2010.

28. Kassam A, Carrau RL, Snyderman CH, Gardner P,Mintz A: Evolution of reconstructive techniquesfollowing endoscopic expanded endonasalapproaches. Neurosurg Focus 19:E8, 2005.

29. Kassam AB, Thomas A, Carrau RL, Snyderman CH,Vescan A, Prevedello D, Mintz A, Gardner P: Endo-scopic reconstruction of the cranial base usinga pedicled nasoseptal flap. Neurosurgery 63 (1 Suppl1):ONS44-ONS52, 2008.

30. Kitano M, Taneda M: Subdural patch graft tech-nique for watertight closure of large dural defectsin extended transsphenoidal surgery. Neurosur-gery 54:653-660, 2004.

31. Laufer I, Anand VK, Schwartz TH: Endoscopic,endonasal extended transsphenoidal, transplanumtranstuberculum approach for resection of supra-sellar lesions. J Neurosurg 106:400-406, 2007.

32. Laws ER, Kanter AS, Jane JA Jr, Dumont AS:Extended transsphenoidal approach. J Neurosurg102:825-827, 2005.

33. Leng LZ, Brown S, Anand VK, Schwartz TH:“Gasket-seal” watertight closure in minimal-access endoscopic cranial base surgery. Neuro-surgery 62(Suppl 2):ONSE342-ONSE343, 2008.

34. Ludemann WO, Stieglitz LH, Gerganov V,Samii A, Samii M: Fat implant is superior tomuscle implant in vestibular schwannoma surgeryfor the prevention of cerebrospinal fluid fistulae.Neurosurgery 63(1 Suppl 1):ONS38-ONS42, 2008.

35. Luginbuhl AJ, Campbell PG, Evans J, Rosen M:Endoscopic repair of high-flow cranial basedefects using a bilayer button. Laryngoscope 120:876-880, 2010.

36. Nyquist GG, Anand VK, Singh A, Schwartz TH:Janus flap: bilateral nasoseptal flaps for anteriorskull base reconstruction. Otolaryngol Head NeckSurg 142:327-331, 2010.

37. Oshino S, Saitoh Y, Yoshimine T: Withstandpressure of a simple fibrin glue sealant: experi-mental study of mimicked sellar reconstruction inextended transsphenoidal surgery. World Neuro-surg 73:701-704, 2010.

38. Park J, Guthikonda M: The Medpor sheet as a sellarbuttress after endonasal transsphenoidal surgery:technical note. Surg Neurol 61:488-492, 2004.

39. Placantonakis DG, Tabaee A, Anand VK,Hiltzik D, Schwartz TH: Safety of low-dose intra-thecal fluorescein in endoscopic cranial basesurgery. Neurosurgery 61:161-165, 2007.

40. Pusic AL, Chen CM, Patel S, Cordeiro PG, Shah JP:Microvascular reconstruction of the skull base:a clinical approach to surgical defect classificationand flap selection. Skull Base 17:5-15, 2007.

41. Rivera-SerranoCM,Oliver CL, Sok J, Prevedello DM,Gardner P, Snyderman CH, Kassam AB, Carrau RL:Pedicled facial buccinator (FAB) flap: a new flap for

WORLD NEUROSURGERY, http://

reconstruction of skull base defects. Laryngoscope120:1922-1930, 2010.

42. Schaberg MR, Anand VK, Schwartz TH: 10 pearlsfor safe endoscopic skull base surgery. Otolar-yngol Clin North Am 43:945-954, 2010.

43. Schwartz TH, Fraser JF, Brown S, Tabaee A,Kacker A, Anand VK: Endoscopic cranial basesurgery: classification of operative approaches.Neurosurgery 62:991-1002, 2008.

44. Snyderman CH, Kassam AB, Carrau R, Mintz A:Endoscopic reconstruction of cranial base defectsfollowing endonasal skull base surgery. Skull Base17:73-78, 2007.

45. Tabaee A, Anand VK, Brown SM, Lin JW,Schwartz TH: Algorithm for reconstruction afterendoscopic pituitary and skull base surgery.Laryngoscope 117:1133-1137, 2007.

46. Tabaee A, Anand VK, Fraser JF, Brown SM,Singh A, Schwartz TH: Three-dimensional endo-scopic pituitary surgery. Neurosurgery 64(5 Suppl2):288-293, 2009.

47. Tabaee APD, Schwartz TH, Anand VJ: Recon-struction after endoscopic skull base surgery. In:Anand VK, Schwartz TH, eds. Practical Endo-scopic Skull Base Surgery. San Diego, CA: PluralPublishing; 2007:191-202.

48. van Aken MO, Feelders RA, de Marie S, van deBerge JH, Dallenga AH, Delwel EJ, Poublon RM,Romijn JA, van der Lely AJ, Lamberts SW, deHerder WW: Cerebrospinal fluid leakage duringtranssphenoidal surgery: postoperative externallumbar drainage reduces the risk for meningitis.Pituitary 7:89-93, 2004.

49. Zanation AM, Carrau RL, Snyderman CH,Germanwala AV, Gardner PA, Prevedello DM,Kassam AB: Nasoseptal flap reconstruction ofhigh flow intraoperative cerebral spinal fluid leaksduring endoscopic skull base surgery. Am J Rhi-nol Allergy 23:518-521, 2009.

50. Zanation AM, Snyderman CH, Carrau RL,Kassam AB, Gardner PA, Prevedello DM: Mini-mally invasive endoscopic pericranial flap: a newmethod for endonasal skull base reconstruction.Laryngoscope 119:13-18, 2009.

Conflict of interest statement: The authors declare that thearticle content was composed in the absence of anycommercial or financial relationships that could be construedas a potential conflict of interest.

Received 16 May 2011; accepted 30 August 2011;published online 7 November 2011

Citation: World Neurosurg. (2013) 80, 5:563-568.http://dx.doi.org/10.1016/j.wneu.2011.08.034

Journal homepage: www.WORLDNEUROSURGERY.org

Available online: www.sciencedirect.com

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dx.doi.org/10.1016/j.wneu.2011.08.034