Does Packing the Eustachian Tube Impact Cerebrospin al Fluid Rhinorrhea Rates in Translabyrinthine Vestibular Schwannoma Resections?

Translabyrinthine Approach for Sporadic Vestibular Schwannoma: Patient Selection, Technical Pearls, and Patient Outcomes

Herein we briefly describe the translabyrinthine approach to vestibular schwannoma resection as well as a focused literature review as to the best candidates, technical recommendations, and key outcomes with respect to other approaches.

Matched Cohort Analysis of the Effect of the Facial Recess Approach on Cerebrospinal Fluid Leak After Translabyrinthine Surgery for Schwannoma

OBJECTIVE

The facial recess approach during translabyrinthine surgery has been used to expose the eustachian tube (ET) for packing. We sought to determine the effect of this technique on the development of postoperative nasopharyngeal cerebrospinal fluid (CSF) leaks.

PATIENTS

Cohorts of patients with cerebellopontine angle schwannomas who underwent a facial recess approach or no facial recess approach were matched based on tumor size.

INTERVENTIONS

Translabyrinthine surgery for tumor resection.

MAIN OUTCOME MEASURES

Postoperative CSF leaks were recorded and nasopharyngeal CSF leaks were utilized as the primary outcome measure.

RESULTS

Using an exact matching protocol based on tumor size, 102 patients were included in each group (204 total, 111 female, 93 male). Overall, 9 patients (4.4%) demonstrated a postoperative nasopharyngeal CSF leak. Postoperative CSF rhinorrhea was noted in 3.9% of the group who underwent a facial recess approach for packing of the ET and 4.9% of the group who did not undergo a facial recess approach. This rate was not significantly different between groups (p = 0.99, Odds ratio: 0.79, 95% CI: 0.15-3.8). Secondary variables including age, tumor size, a diagnosis of NF2, and the packing material used were not significant predictors of nasopharyngeal CSF leaks.

CONCLUSIONS

CSF rhinorrhea is infrequent after translabyrinthine surgery. The incidence of this complication is not affected by whether or not a facial recess approach is performed during surgery to pack the ET. Based on these data, use of this technique should be based on surgeon comfort and preference.

Cerebrospinal Fluid Leak Following Translabyrinthine Vestibular Schwannoma Surgery-Is Mesh Cranioplasty Necessary for Prevention?

OBJECTIVE

Evaluate the incidence of cerebrospinal fluid leak following vestibular schwannoma surgery for mesh cranioplasty closure versus periosteal closure in the translabyrinthine approach. Determine nonsurgical variables associated with higher rates of cerebrospinal fluid leak following vestibular schwannoma surgery.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary academic referral center.

PATIENTS

One hundred thirty-two patients with adequate documentation who underwent sporadic vestibular schwannoma resection via a translabyrinthine approach between 2000 and 2019.

INTERVENTION

Translabyrinthine excision of vestibular schwannoma with mesh cranioplasty closure or watertight periosteal closure.

MAIN OUTCOME MEASURES

Primary outcome measures included the incidence of postoperative cerebrospinal fluid leak, total length of hospital stay (including the initial hospital stay as well as hospital days during any readmission within 30 days), and total operative time.

RESULTS

Our overall cerebrospinal fluid leak rate was 9.1% with a leak rate of 12.8% in our translabyrinthine titanium mesh closure group and 0% in our translabyrinthine periosteal closure. There was no statistically significant effect of age, body mass index, or size of tumor on the incidence of cerebrospinal fluid leak. There was also no statistically significantly difference between the two groups on length of operative time or number of days spent in the intensive care unit.

CONCLUSION

Mesh cranioplasty is not a prerequisite for achieving a low cerebrospinal fluid leak rate following translabyrinthine approach for vestibular schwannoma resection. In our series, a significantly lower cerebrospinal fluid leak rate was demonstrated with the periosteal closure.

Prevention of cerebrospinal fluid leak after vestibular schwannoma surgery: a case-series focus on mastoid air cells' partition

BACKGROUND

Petrous bone pneumatization may be related to cerebrospinal fluid (CSF) leak secondary to vestibular schwannoma surgery.

OBJECTIVE

To assess the association between petrous bone pneumatization and CSF leak in vestibular schwannoma surgery.

METHODS

A retrospective study included 222 consecutive vestibular schwannoma patients treated via a retrosigmoid or translabyrinthine approach in a 17-year period in one University Hospital. Association of CSF leak and petrous bone pneumatization, as seen on CT scans, was assessed on ANOVA and Student's t or Chi-squared test in case of non-parametric distribution.

RESULTS

One hundred and 75 resections were performed on a retrosigmoid approach and 47 on a translabyrinthine approach. Mean age was 53.6 ± 12.9 years. Mean follow-up was 5 years 6 months. Twenty-six patients (11.7%) showed CSF leak and 8 (3.6%) meningitis. Approach (p = 0.800), gender (p = 0.904), age (p = 0.234), body-mass index (p = 0.462), tumor stage (p = 0.681) and history of schwannoma surgery (p = 0.192) did not increase the risk of CSF leak. This risk was unrelated to mastoid pneumatization (p = 0.266). There was a highly significant correlation between internal acousticus meatus (IAM) posterior wall pneumatization and CSF leak after retrosigmoid surgery (p = 0.008). Eustachian tube packing in the translabyrinthine approach did not decrease risk of CSF leak (p = 0.571).

CONCLUSION

Degree of petrous bone pneumatization was not significantly related to risk of CSF leak, but pneumatization of the posterior IAM wall increased this risk in retrosigmoid surgery. Eustachian tube packing in the translabyrinthine approach is not sufficient to prevent postoperative CSF leak. Both approaches had similar rates of CSF leaks, around 12%.

A Systematic Review of Closure Techniques in Lateral Skull Base Tumor Surgery

Introduction  Tumors of the lateral skull base often require collaboration between neurosurgeons and neurotologists for the surgical approach. The three main transosseous surgical approaches are retrosigmoid (RS), translabyrinthine (TL), and middle fossa (MF). The literature reflects a relative paucity regarding the various closure techniques for these approaches and the postoperative complications. We have performed a systematic review comparing closure techniques from each approach. Methods  A systematic review was performed using Ovid MEDLINE (1990-2016) on closure technique and postoperative complications for patients undergoing lateral skull base surgery via the TL, RS, or MF approach. Studies were included if they contained at least 10 patients, described their closure technique, and provided data on postoperative complications. Results  A total of 1,403 studies were reviewed. Of these, 53 studies met inclusion criteria yielding a total of 10,466 subjects in this analysis. The average rate of cerebrospinal fluid leak was 5.3% in the TL approach, 9% in the RS approach, and 6.2% in the MF approach. There was no significant effect of various closure techniques on postoperative wound complications in the MF approach. Multiple factors were identified which affected postoperative wound complication in the RS and TL approaches. Conclusion  There are a plethora of closure techniques for lateral skull base surgery. Several techniques were identified in this review that may affect the postoperative wound complication rates in lateral skull base surgery.

Investigation of Skull-Based Cerebrospinal Fluid Leak Repair: A Single-Institution Comprehensive Study of 116 Cases Over 10 Years

BACKGROUND

Cerebrospinal fluid (CSF) leaks have been historically difficult to diagnose and treat because their cause can widely vary. There are insufficient diagnostic predictors and no clinically accepted standards for their treatment. This large institutional study reports on the diagnosis, management, and outcomes of patients presenting with CSF leak over 10 years and aims to identify potential comorbidities and risk factors for primary and recurrent leaks.

METHODS

Patients diagnosed with CSF leak from 2007 to 2017 were analyzed retrospectively. The data included medical history, body mass index, surgical treatment, and postoperative outcomes.

RESULTS

A total of 116 cases were identified. The location of leaks was 91 CSF rhinorrhea and 28 CSF otorrhea (3 both). The average BMI for females was greater than that of males (P = 0.01). Causes of leak were 64 noniatrogenic, 47 iatrogenic, and 9 traumatic. A total of 108 patients underwent surgical treatment. Sixty-nine were treated by endoscopic approaches, 42 involved open approaches, and 83 involved the placement of a lumbar drain. Eighteen patients had a ventriculoperitoneal shunt and 6 had a lumbar-peritoneal shunt. A total of 78 patients (72.22%) had an associated encephalocele with the CSF leak. The average length of stay was 7.73 days (0.76). The average length of follow-up was 1.58 years (0.22). The primary repair rate was 80.17% (n = 93) and the overall repair outcome was 99.14% (n = 115).

CONCLUSIONS

The overall CSF repair outcome was 99.14% over 10 years at a single institution. Despite this high percentage, CSF leaks continue to be a complex problem and require vigorous multidisciplinary work with close follow-up and use of multiple imaging strategies.

Surgical Parameters for Minimally Invasive Trans-Eustachian Tube CSF Leak Repair: A Cadaveric Study and Literature Review

BACKGROUND

Cerebrospinal fluid rhinorrhea from a lateral skull base defect refractory to spontaneous healing and/or conservative management is most commonly managed via open surgery. Approach for repair is dictated by location of the defect, which may require surgical exploration. The final common pathway is the eustachian tube (ET). Endoscopic ET obliteration via endonasal and lateral approaches is under development. Whereas ET anatomy has been studied, surgical landmarks have not been previously described or quantified. We aimed to define surgical parameters of specific utility to endoscopic ET obliteration.

METHODS

A literature review was performed of known ET anatomic parameters. Next, using a combination of endoscopic and open techniques in cadavers, we cannulated the intact ET and dissected its posterior component to define the major curvature position of the ET, defined as the genu, and quantified the relative distances through the ET lumen. The genu was targeted as a major obstacle encountered when cannulating the ET from the nasopharynx.

RESULTS

Among 10 ETs, we found an average distance of 23 ± 5 mm from the nasopharynx to the ET genu, distance of 24 ± 3 mm from the genu to the anterior aspect of the tympanic membrane and total ET length of 47 ± 4 mm.

CONCLUSIONS

Although membranous and petrous components of the ET are important to its function, the genu may be a more useful surgical landmark. Basic surgical parameters for endoscopic ET obliteration are defined.

Petrous Apex Pneumatization: Influence on Postoperative Cerebellopontine Angle Tumor Cerebrospinal Fluid Fistula

OBJECTIVE

Multiple investigators have sought to identify risk factors for cerebrospinal fluid (CSF) leak following cerebellopontine angle (CPA) tumor resection. We evaluated whether pneumatization of the petrous apex (PA) is a risk factor for CSF fistula.

METHOD

We conducted a retrospective chart review at 2 major tertiary academic institutions undergoing CPA tumor resection and analyzed their respective head or temporal computed tomography (CT) scans if available.

RESULTS

A total of 91 cases were identified; 51 (64%) demonstrated PA pneumatization, and a total of 17 CSF leaks were identified. We discovered higher rates of CSF leak (25.0% vs 13.7%; P = .273) and CSF rhinorrhea (15.0% vs 5.9%; P = .174) in patients with PA pneumatization compared to those without PA pneumatization.

CONCLUSIONS

Isolated PA pneumatization may be a risk factor and communication pathway for CSF fistula. Further studies will need to be broadened across multiple institutions to draw any additional and stronger conclusions.

Minimally invasive endoscopic repair of refractory lateral skull base cerebrospinal fluid rhinorrhea: case report and review of the literature

Cerebrospinal fluid (CSF) leaks occur in approximately 10% of patients undergoing a translabyrinthine, retrosigmoid, or middle fossa approach for vestibular schwannoma resection. Cerebrospinal fluid rhinorrhea also results from trauma, neoplasms, and congenital defects. A high degree of difficulty in repair sometimes requires repetitive microsurgical revisions-a rate of 10% of cases is often cited. This can not only lead to morbidity but is also costly and burdensome to the health care system. In this case-based theoretical analysis, the authors summarize the literature regarding endoscopic endonasal techniques to obliterate the eustachian tube (ET) as well as compare endoscopic endonasal versus open approaches for repair. Given the results of their analysis, they recommend endoscopic endonasal ET obliteration (EEETO) as a first- or second-line technique for the repair of CSF rhinorrhea from a lateral skull base source refractory to spontaneous healing and CSF diversion. They present a case in which EEETO resolved refractory CSF rhinorrhea over a 10-month follow-up after CSF diversions, wound reexploration, revised packing of the ET via a lateral microscopic translabyrinthine approach, and the use of a vascularized flap had failed. They further summarize the literature regarding studies that describe various iterations of EEETO. By its minimally invasive nature, EEETO imposes less morbidity as well as less risk to the patient. It can be readily implemented into algorithms once CSF diversion (for example, lumbar drain) has failed, prior to considering open surgery for repair. Additional studies are warranted to further demonstrate the outcome and cost-saving benefits of EEETO as the data until now have been largely empirical yet very hopeful. The summaries and technical notes described in this paper may serve as a resource for those skull base teams faced with similar challenging and otherwise refractory CSF leaks from a lateral skull base source.

Managing Cerebrospinal Fluid Rhinorrhea after Lateral Skull Base Surgery via Endoscopic Endonasal Eustachian Tube Closure

Background

A cerebrospinal fluid (CSF) leak, commonly presenting as rhinorrhea, is a well-recognized complication of lateral skull base surgery. Failure of conservative treatment measures in these cases necessitates surgical intervention.

Objective

Our aim is to demonstrate that endoscopic endonasal closure of the eustachian tube is a reasonable alternative to more traditional techniques for management of recalcitrant postoperative CSF rhinorrhea after removal of middle and posterior cranial fossa lesions.

Methods

A retrospective chart review was performed for patients who presented with CSF rhinorrhea after lateral skull base surgery at a tertiary medical center over a 17-year period, from 1997 to 2014. Nine patients managed with endoscopic endonasal closure of the eustachian tube were evaluated for preoperative hearing status, approach to lateral skull base surgery, pathology, size and location of the tumor, timing and presentation of CSF leak, methods of treatment, length of hospital stay, complications, and success of the procedure.

Results

Of the nine patients included in this review, seven were managed successfully with endoscopic endonasal eustachian tube closure. Of those seven, one required a revision procedure. Average length of postoperative stay was 5.8 days. There were no major complications. Follow up of greater than 100 months has been achieved since the first procedure.

Conclusion

Endoscopic endonasal eustachian tube closure is a safe, minimally invasive and effective method for obliteration of the eustachian tube orifice. The algorithm for management of recalcitrant postoperative CSF rhinorrhea after lateral skull base surgery should include endoscopic endonasal closure of the eustachian tube.

Removal of large or giant sporadic vestibular schwannomas via translabyrinthine approach: a report of 115 cases

BACKGROUND/AIMS

The present study was a retrospective analysis of surgical outcomes of large or giant vestibular schwannomas (VSs) via a translabyrinthine approach (TLA).

METHODS

One hundred and fifteen sporadic large or giant VSs (maximal diameter in the cerebellopontine angle ≥31 mm) were operated via TLA between January 2001 and December 2010. We divided patients into two groups: cystic VS (CVS) and solid VS (SVS) group. The surgical outcomes were recorded and compared.

RESULTS

Total, near total, and subtotal tumor removal rate was 89.6, 7.8, and 2.6%, respectively. The near total removal rate in CVS was higher than that in SVS (16.7 vs. 3.8%). The anatomical facial nerve (FN) integrity was preserved in 101 patients (87.8%). More FNs in CVS were interrupted (22.2%). There were 29.6, 56.5, and 13.9% of patients who had a short-term (1 month) FN function of House-Brackmann grade I or II, III or IV, and V or VI, respectively. The CVS had worse FN function than the SVS group. The mortality rate was 0.9%. Cerebrospinal fluid leakage occurred in 8 patients (7.0%). Four (3.5%) patients had recurrence.

CONCLUSIONS

Cyst formation is a crucial factor for surgical outcome of VS. With near total or subtotal tumor removal, worse functional outcomes in large or giant CVSs should be foreseen.

Petrous carotid exposure with eustachian tube preservation: a morphometric elucidation

Inadvertent injury to eustachian tube leading to cerebrospinal fluid rhinorrhea is a known complication associated with drilling of Glasscock's triangle to expose the horizontal petrous internal carotid artery (ICA) for management of difficult tumors (especially malignant) or aneurysms at the cranial base. Contrary to the usual approach, we hypothesize that a "medial-to-lateral" approach to Glasscock's triangle drilling will minimize eustachian tube injury. Four formalin-fixed human cadaveric heads were dissected, and underwent appropriate morphometric analysis; yielding a total of eight datasets. The diameter of the horizontal petrous ICA exposed was 4.7 ± 0.9 mm (range, 3.8 to 5.6 mm).The mean distance from the medial carotid wall midpoint to the medial-most point on the eustachian tube was 6.35 ± 0.58 mm (range, 5.4 to 7.1 mm), yielding a "safety zone" for eustachian tube, ranging 0.2 to 1.9 mm lateral to the lateral carotid wall. With the medial-to-lateral approach, the eustachian tube remained preserved in all the specimens. The results of our study provide a practical, consistent, and safe method of maximizing horizontal petrous carotid artery exposure while minimizing the eustachian tube injury.

Less than 1% cerebrospinal fluid leakage in 1,803 translabyrinthine vestibular schwannoma surgery cases

OBJECTIVE

To determine the incidence rate of cerebrospinal fluid (CSF) leak after translabyrinthine vestibular schwannoma surgery since the alteration of the surgical procedure. To compare with previous series and other series in literature.

STUDY DESIGN

Database analysis.

SETTING

Tertiary referral neurotologic private practice.

PATIENTS

A series of 1,803 patients who underwent translabyrinthine vestibular schwannoma surgery between 1993 and 2009. The result of this group was compared with corresponding series.

INTERVENTION

Translabyrinthine and extended translabyrinthine vestibular schwannoma surgery. Literature review and comparison.

MAIN OUTCOME MEASURES

Rates of CSF leak in this series and historical perspective of the outcome.

RESULTS

Fifteen patients (0.8%) of 1,803 cases had CSF leaks. The method used since 1993 has shown a significant improvement compared with major case series of the last 10 years.

CONCLUSION

The methods used in translabyrinthine vestibular schwannoma surgery in our center can reduce CSF leakage to an absolute minimum. Compared with all large series, this could be a new era of translabyrinthine vestibular schwannoma surgery.