The Incidence of Cerebrospinal Fluid Leak after Vestibular Schwannoma Surgery

Surgical approaches and complications in the removal of vestibular schwannomas

Vestibular schwannomas are benign tumors that usually originate from the balance portion of cranial nerve VIII. The treatment options currently available for vestibular schwannomas include observation with serial imaging, stereotactic radiation, and microsurgical removal. Although the ultimate goal in treatment of vestibular schwannomas is preservation of life, the best option for each patient depends on symptoms, tumor size, tumor location, and the patient's general health and age. Surgical exposure of the cerebellopontine angle for removal of vestibular schwannomas can be performed safely via a translabyrinthine, retrosigmoid, and middle fossa approach. Each approach has its advantages and disadvantages. The goal of surgery is complete eradication of tumor with preservation of hearing and facial nerve function when possible.

Guiding patients through the choices for treating vestibular schwannomas: balancing options and ensuring informed consent

Counseling patients who are diagnosed with vestibular schwannomas, formerly known as acoustic neuromas, can be challenging. The health care provider has the responsibility to explain, in understandable language, to the patient or legal representative the proposed treatment options, risks and complications associated with each form of treatment, and alternatives to treatment, including no therapy. Patients should be encouraged to gather information before making a treatment decision. For the physicians managing these patients, information should be delivered in a balanced way to ensure patient understanding of their options leading to adequate informed consent.

Prevention and Treatment of Cerebrospinal Fluid Leak After Translabyrinthine Acoustic Tumor Removal

OBJECTIVE

To determine the incidence rate of cerebrospinal fluid (CSF) leak after translabyrinthine acoustic tumor removal using titanium mesh cranioplasty and to compare with previous series and historical controls.

STUDY DESIGN

Database analysis with historical controls.

SETTING

Tertiary referral neurotologic private practice.

PATIENTS

The series of 389 patients who underwent titanium mesh cranioplasty after translabyrinthine tumor removal between March 2003 and July 2005. The results were compared with those in a group of 1,195 translabyrinthine tumor removal patients from our previously published series and with those in a group of 324 patients from the immediately preceding two-year period.

INTERVENTION

Cranioplasty using titanium mesh after acoustic tumor removal.

MAIN OUTCOME MEASURES

Rates of CSF leak for this method and previous methods of closure.

RESULTS

Thirteen patients (3.3%) had CSF leaks when using the new method of titanium mesh closure. This compares with rates of 10.9% and 8.7% in series in which other methods of closure were used (p < 0.001 and 0.003). The rates of CSF leak requiring reoperation were 0.5%, 2.5%, and 1.9% for the new and the two older series, respectively.

CONCLUSION

In our hands, titanium mesh cranioplasty seems to reduce the rate of CSF leaks after the translabyrinthine removal of acoustic tumors.

Safety and efficacy of a novel polyethylene glycol hydrogel sealant for watertight dural repair

Object

The authors prospectively evaluated the safety and efficacy of a novel polyethylene glycol (PEG) hydrogel sealant in patients undergoing elective cranial surgery with documented cerebrospinal fluid (CSF) leakage after sutured dural repair.

Methods

The PEG hydrogel sealant was used at 11 different study sites in 111 patients with documented intraoperative CSF leakage after neurosurgical dural repair for a variety of conditions. Intraoperative CSF leakage was either spontaneous or induced by a Valsalva maneuver. Patients were monitored for 3 months postoperatively with physical examinations, clinical laboratory analyses, and diagnostic imaging.

The PEG hydrogel sealant was 100% effective in stopping CSF leakage in all patients. There were no sealant-related adverse events and all clinical outcomes were consistent with expectations for seriously ill patients undergoing prolonged neurosurgical procedures.

Conclusions

The PEG hydrogel sealant provides a safe and effective watertight closure when used as an adjunct to sutured dural repair during cranial surgery.

Approach Design and Closure Techniques to Minimize Cerebrospinal Fluid Leak after Cerebellopontine Angle Tumor Surgery

OBJECTIVE

The purpose of the study was to identify specific aspects of surgical approach design and closure technique aimed at reducing the incidence of cerebrospinal fluid leak after cerebellopontine angle tumor surgery.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

All patients undergoing cerebellopontine angle tumor surgery at the study institution from January 1996 through September 2004.

MAIN OUTCOME MEASURE

The presence or absence of cerebrospinal fluid leak after various surgical approaches for a wide variety of cerebellopontine angle tumors.

RESULTS

Three hundred forty three patients underwent surgery for cerebellopontine angle tumors at the study institution during the study period. Tumor types in descending order of frequency were as follows: acoustic neuroma, 244; cerebellopontine angle meningiomas, 33; petroclival meningiomas, 32; foramen magnum meningiomas, 10; epidermoid tumors, 9; facial nerve tumors, 6; hemangiopericytomas, 3; schwannomas of glossopharyngeal/spinal accessory nerves, 3; and unusual internal auditory canal tumors, 3. Surgical approaches used for tumor resection included translabyrinthine, retrosigmoid, combined transpetrosal, far lateral/transcondylar, middle cranial fossa, and extended middle cranial fossa. During the nearly 8-year study period, four postoperative cerebrospinal fluid leaks were encountered, resulting in a leak rate of 1.2%. Two of these patients required surgical repair of their leaks; the other two stopped spontaneously. The authors describe specific aspects of approach design and closure that appear to have a positive impact on postoperative cerebrospinal fluid leak rates.

CONCLUSION

Attention to specific aspects of surgical approach design and wound closure results in a reduced incidence of cerebrospinal fluid leak after surgery for cerebellopontine angle tumors.

Synthesizing medical evidence: systematic reviews and metaanalyses

Systematic reviews and metaanalyses have become increasingly popular ways of summarizing, and sometimes extending, existing medical knowledge. In this review the authors summarize current methods of performing meta-analyses, including the following: formulating a research question; performing a structured literature search and a search for trials not published in the formal medical literature; summarizing and, where appropriate, combining results from several trials; and reporting and presenting results. Topics such as cumulative and Bayesian metaanalysis and metaregression are also addressed. References to textbooks, articles, and Internet resources are also provided. The goal is to assist readers who wish to perform their own metaanalysis or to interpret critically a published example.

Counseling Patients on Surgical Options for Treating Acoustic Neuroma

The selection of surgical approach for the removal of AN is a complex one, depending on factors related to specific tumor anatomy, patient characteristics, and the familiarity and skill level of the skull base team.Overall, the literature supports that surgical outcomes are acceptable in regard to tumor removal, patient safety, and complication rates. The inconsistent reporting methods in the current literature make it difficult to assess logically the rates for hearing preservation, facial nerve outcome, and complications as controlled for tumor size and other preoperative patient characteristics. The best conclusions would be from prospective surgical trials controlling for patient factors, size of the tumor, and experience of the skull base team. In the absence of such studies, formal meta-analyses may help clarify specific differences among approaches.

Management Options for Cerebrospinal Fluid Leak after Vestibular Schwannoma Surgery and Introduction of an Innovative Treatment

OBJECTIVE

To review the management of cerebrospinal fluid leak after vestibular schwannoma removal reported in the literature and to present a novel approach to management of recalcitrant cases.

DATA SOURCES

MEDLINE and PubMed literature search using the terms "cerebrospinal fluid leak" or "cerebrospinal fluid fistula" and "acoustic neuroma" or "vestibular schwannoma" covering the period from 1985 to present in English. A review of bibliographies of these studies was also performed.

STUDY SELECTION

Criteria for inclusion in this meta-analysis consisted of the availability of extractable data from studies presenting a defined group of patients who had undergone primary vestibular schwannoma removal and for whom the presence and absence of cerebrospinal fluid leakage was reported. Studies reporting combined approaches were excluded. No duplications of patient populations were included. Twenty-five studies met the inclusion criteria.

DATA EXTRACTION

Quality of the studies was determined by the design of each study and the ability to combine the data with the results of other studies. All of the studies were biased by their retrospective, nonrandomized nature.

DATA SYNTHESIS

Significance (p < 0.05) was determined using the chi test.

CONCLUSIONS

Incisional cerebrospinal fluid leakage responded well to local management and lumbar drainage. Rhinorrhea often necessitated surgical intervention. No specific reoperation techniques correlated exclusively with better reoperation outcomes. The transaural/transnasal approach presents an alternative for surgical management of cerebrospinal fluid rhinorrhea.