Postoperative Cerebrospinal Fluid Leak Rate Research Articles

Efficacy of the pedicled nasoseptal flap without cerebrospinal fluid (CSF) diversion for repair of skull base defects: incidence of postoperative CSF leaks

The advances in endoscopic skull base surgery have led to the resection of increasingly larger cranial base lesions and the creation of larger skull base defects with the potential for increased postoperative high-flow cerebrospinal fluid (CSF) leaks. These concerns led to the development of the vascularized pedicled nasoseptal flap (PNSF), which is now used as the mainstay for repair of large skull base defects in many academic centers. In this report, we review the incidence of postoperative CSF leaks in our institution in patients undergoing endoscopic skull base repair of high-flow CSF leaks with a vascularized PNSF without concurrent CSF diversion. We performed a retrospective analysis at our tertiary care medical center on patients who underwent endoscopic repair of high-flow CSF leaks using a PNSF without CSF diversion between July 2008 and August 2011. Repair materials, incidence of postoperative CSF leaks, and demographic data were collected. Fifty-nine high-flow CSF leaks were repaired with a PNSF and other repair materials, without the use of lumbar catheter drainage. No postoperative CSF leak occurred in this cohort of patients. The overall postoperative CSF leak rate was 0%. Meticulous multilayer-closure of skull base defects is critical to prevent postoperative CSF leaks. Although lumbar drainage may be useful in select scenarios, it carries inherent risks of intracranial hypotension and pneumocephalus, and may not be necessary for routine management of high-flow CSF leaks in conjunction with a robust PNSF. Further prospective randomized controlled studies may be warranted to evaluate the efficacy of postoperative lumbar drainage.

Nasoseptal flap repair after endoscopic transsellar versus expanded endonasal approaches: Is there an increased risk of postoperative cerebrospinal fluid leak?

The development of expanded endoscopic endonasal approaches (EEAs) has allowed resection of cranial-base lesions beyond the sella. One major criticism is an increased risk of postoperative cerebrospinal fluid (CSF) leakage because of the larger skull base defect. We evaluated our experience with vascularized pedicled nasoseptal flap (PNSF) reconstruction and compared the postoperative CSF leak rates between patients undergoing endoscopic transsphenoidal (transsellar) approaches versus expanded EEA (transplanum-transtuberculum, transcribriform, transclival). Retrospective analysis at a tertiary care medical center. A retrospective review of a prospective database was performed on patients who underwent PNSF reconstruction for intraoperative high-flow CSF leaks after EEA between December 2008 and August 2011. Demographic data, repair materials, surgical approach, and incidence of postoperative CSF leaks were collected. Thirty-seven transsellar defects (group I) were repaired with a PNSF, and 32 expanded EEA defects (19 transplanum-transtuberculum, 10 transcribriform, three transclival) (group II) were repaired with a PNSF. No postoperative CSF leaks occurred in group I. One delayed postoperative CSF leak was encountered in group II leading to a 3.1% leak rate in that group. The incidence of postoperative CSF leakage was not significantly different between the two groups (P > .05). Our overall success rate in this series using a PNSF was 98.6%. Based on our data, there is no significant increased risk of postoperative CSF leak between transsellar and expanded EEA defects when a PNSF is used. The potential risk of postoperative CSF leaks associated with larger defects created through expanded EEA can be minimized by multilayered closure with a PNSF and meticulous surgical technique.

Management of CSF Leak After Vestibular Schwannoma Surgery

To the Editor We have read with great interest the article entitled “Management of Cerebrospinal Fluid Leaks After Vestibular Schwannoma Surgery,” by Mangus et al. (1). We would like to congratulate the authors for their valuable contribution to the relevant literature. Cerebrospinal fluid (CSF) leak is still the most common and challenging complication of vestibular schwannoma surgery, and despite multiple articles suggesting solutions for this problem, it is still a frequent encountered drawback, sometimes at unacceptable high rates. The authors state that postoperative CSF leak rates reported in the literature range from 2% to 30%. Surprisingly, three publications of our group with 0%, 1.4%, and 0.8% CSF leakage are not taken into account (2–4). In this study the authors reported an overall incidence CSF leak of 12.9%. However, if we consider changes in rates over time, we notice that CSF leak rate dropped down from 27% to 6%. We agree with the sentence that this downward trend is consistent with the introduction of abdominal fat graft and modifications in closure techniques, but it would have been worthy to detail the different steps of their closure technique. Indeed, we believe that the main reasons of variation of CSF leak rates in the literature are factors related to surgical technique rather than patient variables. It is stated in this study that authors use fat and muscle grafts for Eustachian tube and middle ear space obliteration in a translabyrinthine approach. Although appealing, muscle graft tends to atrophy, whereas fat graft tends to dissolve on contact with air, which could lead to delayed rhinorrhea. Packing the middle ear cleft with dry periosteum collected at the beginning while drilling the mastoid seems more successful. Up to 1993, the overall incidence of CSF leak in our institution was 6.9%. Given this significant high rate, we decided to modify our closure technique in an attempt to lower its occurrence. In translabyrinthine approach, all air cells should be inspected especially at the level of facial and subfacial recesses, and patent ones must be sealed using bone wax. Next, incus is removed through the aditus, taking care not to dislocate the stapes to avoid CSF leakage through the oval window. Middle ear cleft is then packed with previously collected dry periosteum, which prevents later occurrence of rhinoliquorrhea. At the end, thin and long autologous fat strips are carefully introduced deep in the cerebellopontine angle, and the musculofascial layer is sutured in a watertight manner adding to the seal against leakage. As a result, the incidence dramatically dropped down to less than 1% and still unchanged since (4). Further evidence of the success of this technique is supported by Mamikoglu et al. (5) and Hardy et al. (6) showing a reduction of CSF leak in enlarged traslabyrinthine approach, from 17% to 2.3% and from 13% to 1.6%, respectively (also these 2 last articles have not been cited). The similar concept, by isolating the middle ear from the surgical field, also has been successfully adopted in retrosigmoid approach (7), with an improvement of the CSF rate from 21.4% to 1.8%. Mehdi Ben Ammar, M.D. Department of Neurosurgery Military Hospital of Tunis University of Tunis El Manar Tunisia Paul Merkus, M.D., Ph.D. Department of Otorhinolaryngology-Head and Neck Surgery VU University Medical Center Amsterdam, The Netherlands Filippo Di Lella, M.D., Ph.D. Mario Sanna, M.D. Gruppo Otologico Piacenza Roma, Italy

Endoscopic Nasoseptal Flap Repair of Skull Base Defects

We compared the incidence of postoperative cerebrospinal fluid (CSF) leaks in patients undergoing endoscopic skull base repair with a pedicled nasoseptal flap (PNSF) with or without the addition of a dural sealant. Retrospective analysis at a tertiary care medical center. A retrospective analysis was performed at our tertiary care medical center on patients who underwent endoscopic repair of high-flow CSF leaks using a PNSF between December 2008 and August 2011. Repair materials, incidence of postoperative CSF leaks, and demographic data were collected. Thirty-two high-flow CSF leaks were repaired with a PNSF alone without dural sealant (group A), and 42 were repaired with a PNSF with the addition of a dural sealant (group B). In group A, there were no postoperative CSF leaks (0%), whereas in group B, there was 1 delayed postoperative CSF leak, resulting in a 2.4% leak rate. The incidence of postoperative CSF leakage was not significantly different between the 2 groups (P = .38). The overall postoperative CSF leak rate was 1.4%. The use of dural sealants when performing endoscopic PNSF repair of high-flow CSF leaks is not supported by our data. In addition, this practice may significantly increase surgical cost. We encountered no postoperative CSF leaks in patients with high-flow CSF leaks treated with PNSF alone without dural sealants. Meticulous surgical technique and proper positioning of the PNSF seem to obviate the need for dural sealants during endoscopic skull base reconstruction of high-flow CSF leaks.

Endoscopic Nasoseptal Flap Repair of Skull Base Defects: Is Addition of a Dural Sealant Necessary?

Background: We compared the incidence of postoperative cerebrospinal fluid (CSF) leaks in patients undergoing endoscopic skull base repair with a pedicled nasoseptal flap (PNSF), with or without the addition of a dural sealant. Methods: A retrospective analysis of a prospective database was performed on patients who underwent endoscopic repair of high-flow CSF leaks using a PNSF between December 2008 and August 2011. Repair materials, incidence of postoperative CSF leaks, and demographic data were collected. Results: Thirty-two high-flow CSF leaks were repaired with a PNSF alone without dural sealant (Group I), and 42 were repaired with a PNSF with the addition of a dural sealant (Group II). In Group I, there were no postoperative CSF leaks (0%), whereas in Group II, there was one delayed postoperative CSF leak, resulting in a 2.4% leak rate. The incidence of postoperative CSF leakage was not significantly different between the two groups (P > 0.05). The overall postoperative CSF leak rate was 1.4% in this cohort. Conclusions: The use of dural sealants when performing endoscopic PNSF repair of high-flow CSF leaks is not supported by our data. In addition, this practice may significantly increase surgical cost. We encountered no postoperative CSF leaks in patients with high-flow CSF leaks treated with PNSF alone without dural sealants. Meticulous surgical technique and proper positioning of the PNSF seem to obviate the need for dural sealants during endoscopic skull base reconstruction of high-flow CSF leaks.

Endoscopic, Endonasal Resection of Craniopharyngiomas

The endoscopic, endonasal, extended transsphenoidal approach is a minimal-access technique for managing craniopharyngiomas. Outcome measures such as return to employment and body mass index (BMI) have not been reported and are necessary for comparison with open transcranial approaches. Most prior reports of the endoscopic, endonasal approach have reported unacceptably high cerebrospinal fluid (CSF) leak rates. To assess the outcome of endoscopic, endonasal surgery in a consecutive series of craniopharyngiomas with special attention to extent of resection, CSF leak, return to employment, and BMI. Twenty-six surgeries were performed on 24 patients at Weill Cornell Medical College-New York Presbyterian Hospital. Five patients had recurrent lesions. Gross-total resection (GTR) was attempted in 21 surgeries. Indications for intended subtotal resection were advanced age, medical comorbidities, preservation of pituitary function, and hypothalamic invasion. Mean tumor diameter was 2.9 cm. GTR (18 surgeries) or near-total (>95%) resection (2 surgeries) was achieved in 95% when GTR was the goal. Seven patients received postoperative radiation therapy. Mean follow-up was 35 months with no recurrences in GTR cases and stable disease in all patients at last follow-up. Vision improved in 77%. Diabetes insipidus and panhypopituitarism developed in 42% and 38%, respectively. A more than 9% increase in BMI occurred in 39%; 69% returned to their preoperative profession/schooling. The postoperative CSF leak rate was 3.8%. Minimal-access, endoscopic, endonasal surgery for craniopharyngioma can achieve high rates of GTR with low rates of CSF leak. Return to employment and obesity rates are comparable to microscope-assisted transcranial and transsphenoidal reports.

B005 Cochlear implantation in very young children

Endoscopic endonasal transplanum and transsellar approaches are frequently utilized to manage pituitary adenomas, craniopharyngiomas, and meningiomas. In addition to the intrinsic panoramic view from the endoscope, wide access using both nostrils and a posterior septectomy can aid in both visualization and complete tumor removal. When necessary, a posterior ethmoidectomy and/or partial middle turbinate resection can be used to improve access. Recognizing key anatomic landmarks from an endonasal viewpoint such as the sella turcica, tuberculum sella, planum sphenoidale, internal carotid arteries, and optic nerves is critical. For sellar surgery, a wide sellar opening can be created from the tuberculum to the sellar floor and laterally to the medial cavernous sinus wall while maintaining the sellar dura. For transplanum approaches, the lateral bony osteotomies parallel the optic canals and are connected to the planum osteotomy that is slightly anterior to the tumor extent. The tuberculum sella can then be removed to expose the sphenoid limbus, a reliable landmark for the optic apparatus. Reconstruction of these skull base defects ranges from simple to complex depending on the size, flow of cerebrospinal fluid (CSF), and degree of intracranial dissection. Vascularized mucoperiosteal flaps like the nasoseptal flap have reduced the rates of postoperative CSF leak. Either early harvest of the nasoseptal flap or preservation of the vascular pedicle is advocated to increase the reconstructive options.

Use of Tissue Glues in Endoscopic Pituitary Surgery: A Cost Comparison

Post-operative cerebrospinal fluid (CSF) leaks are a common complication of endoscopic pituitary surgery and account for a significant proportion of hospital costs associated with this procedure. Tisseel® is a tissue glue commonly used as an adjunct in dural repair but is not optimal for this purpose. DuraSeal® has several properties advantageous for dural repair but is not widely accepted in Canada partly due to its increased cost. A cost analysis of DuraSeal® versus Tisseel® in endoscopic pituitary surgery. A cost analysis was performed based on typical endoscopic pituitary surgery cases performed at our tertiary care institution. Operating room, hospital admission, and surgical sealant costs were obtained directly while estimates of patient recovery time and post-operative CSF leak rates were based on consensus values reported in the literature. Outcomes were reported for various possible clinical scenarios of sealant use. In a model where surgical sealant is employed only in high-risk cases, use of DuraSeal® allows for a yearly cost savings of at least $4486.72. If surgical sealant is used in all cases, regular use of DuraSeal® versus Tisseel® either marginally reduces yearly costs or increases them by a maximum of $7619.25, depending on the case volume and estimated post-operative CSF leak rate. In most clinical scenarios, use of DuraSeal® in endoscopic pituitary surgery may reduce overall yearly hospital costs compared to Tisseel®.

FAT IMPLANT IS SUPERIOR TO MUSCLE IMPLANT IN VESTIBULAR SCHWANNOMA SURGERY FOR THE PREVENTION OF CEREBROSPINAL FLUID FISTULAE

Abstract Objective: Meticulous sealing of opened air cells in the petrous bone is necessary for the prevention of cerebrospinal fluid (CSF) fistulae after vestibular schwannoma surgery. We performed a retrospective analysis to determine whether muscle or fat tissue is superior for this purpose. Methods: Between January 2001 and December 2006, 420 patients underwent retrosigmoidal microsurgical removal by a standardized procedure. The opened air cells at the inner auditory canal and the mastoid bone were sealed with muscle in 283 patients and with fat tissue in 137 patients. Analysis was performed regarding the incidence of postoperative CSF fistulae and correlation with the patient's sex and tumor grade. Results: The rate of postoperative CSF leak after application of fat tissue was lower (2.2%) than after use of muscle (5.7%). Women had less postoperative CSF leakage (3.4%) than men (5.6%). There was an inverse correlation with tumor grade. Patients with smaller tumors seemed to have a higher rate of CSF leakage than those with large tumors without hydrocephalus. Only large tumors with severe dislocation of the brainstem causing hydrocephalus showed a higher incidence of CSF leaks. Conclusion: Fat implantation is superior to muscle implantation for the prevention of CSF leakage after vestibular schwannoma surgery and should, therefore, be used for the sealing of opened air cells in cranial base surgery.

Fat implant is superior to muscle implant in vestibular schwannoma surgery for the prevention of cerebrospinal fluid fistulae.

Meticulous sealing of opened air cells in the petrous bone is necessary for the prevention of cerebrospinal fluid (CSF) fistulae after vestibular schwannoma surgery. We performed a retrospective analysis to determine whether muscle or fat tissue is superior for this purpose. Between January 2001 and December 2006, 420 patients underwent retrosigmoidal microsurgical removal by a standardized procedure. The opened air cells at the inner auditory canal and the mastoid bone were sealed with muscle in 283 patients and with fat tissue in 137 patients. Analysis was performed regarding the incidence of postoperative CSF fistulae and correlation with the patient's sex and tumor grade. The rate of postoperative CSF leak after application of fat tissue was lower (2.2%) than after use of muscle (5.7%). Women had less postoperative CSF leakage (3.4%) than men (5.6%). There was an inverse correlation with tumor grade. Patients with smaller tumors seemed to have a higher rate of CSF leakage than those with large tumors without hydrocephalus. Only large tumors with severe dislocation of the brainstem causing hydrocephalus showed a higher incidence of CSF leaks. Fat implantation is superior to muscle implantation for the prevention of CSF leakage after vestibular schwannoma surgery and should, therefore, be used for the sealing of opened air cells in cranial base surgery.

ENDOSCOPIC RECONSTRUCTION OF THE CRANIAL BASE USING A PEDICLED NASOSEPTAL FLAP

Reconstruction of the cranial base using vascularized tissue promotes rapid and complete healing, thus avoiding complications caused by persistent communication between the cranial cavity and the sinonasal tract. The Hadad-Bassagasteguy flap (HBF), a neurovascular pedicled flap of the nasal septum mucoperiosteum and mucoperichondrium based on the nasoseptal artery, seems to be advantageous for the reconstruction of the cranial base after endonasal cranial base surgery. We performed a retrospective review of patients who underwent endonasal cranial base surgery at the University of Pittsburgh Medical Center from January 30, 2006 to January 30, 2007, identifying patients who experienced reconstruction with a vascularized septal mucosal flap (HBF). We analyzed the demographic data, pathological characteristics, site and extent of resection, use of cerebrospinal fluid (CSF) diversion techniques, and outcome. Seventy-five patients who underwent endonasal cranial base endoscopic surgery received repair with the HBF. In this population, we encountered eight postoperative CSF leaks (10.66%), all in patients who required intra-arachnoidal dissection. When we correct the statistical analysis to include only patients with intra- arachnoidal lesions, the postoperative CSF leak rate is 14.5% (eight of 55 patients). It is notable that six CSF (33%) leaks occurred in our first 25 repairs, whereas we encountered only two postoperative leaks (4%) in the last 50 patients. The corrected CSF leak rate, considering only intra-arachnoidal lesions, was two (5.4%) of 37 patients. This improvement in the CSF leak rate reflects our growing experience and comfort with this reconstructive technique. All of our failures could be matched to a specific technical mistake. In addition, we modified the flap-harvesting technique to allow for staged procedures and the removal of caudal lesions. These special circumstances require storage of the flap in the antrum during the removal of caudal lesions, and suturing of the flap in its original position for staged procedures. One patient experienced a posterior nose bleed from the posterior nasal artery. This was controlled with bipolar electrocautery, thereby preserving the flap blood supply. We encountered no infectious or wound complications in this series of patients. The donor site accumulates crusting, which requires debridement until mucosalization is complete; this usually occurs 6 to 12 weeks after surgery. The HBF is a versatile and reliable reconstructive technique for repairing defects of the anterior, middle, clival, and parasellar cranial base. Its use has resulted in a significant decrease in our incidence of CSF leaks after endonasal cranial base surgery. Attention to technical details is of paramount importance to achieve the best outcomes.

ENDOSCOPIC ENDONASAL RESECTION OF ANTERIOR CRANIAL BASE MENINGIOMAS

OBJECTIVE The endonasal route may be feasible for the resection of anterior cranial base tumors that abut the paranasal sinuses. There are several case reports and mixed case series discussing this approach. Other than pituitary adenomas, there is a lack of literature describing the outcomes of endonasal approaches for single-tumor types such as meningiomas. METHODS In this study, we describe our current endoscopic endonasal technique and demonstrate the feasibility of using it to access anterior cranial base meningiomas from the back wall of the frontal sinus to the sella and laterally to the region of the midorbit. After this discussion, which includes key technical considerations and nuances, we address safety and efficacy by reporting the outcomes of our early experience with endoscopic endonasal resection of 35 anterior cranial base meningiomas. RESULTS A total of 35 patients underwent endoscopic endonasal resection of anterior cranial base meningiomas from October 2002 to October 2005. Degree of resection by tumor location was as follows: 10 of the 12 (83%) patients with olfactory groove meningiomas planned for complete resection underwent gross total (seven of 12) or near-total (>95%) (three of 12) resection (67% of all 15 olfactory tumors); 12 of 13 patients (92%) with tuberculum meningiomas underwent gross (11 of 13) or near (>95%) (one of 13) total resection; five patients diagnosed with petroclival meningiomas had successful resection of the parasellar portion of their tumors with relief of visual symptoms (no patients underwent complete resection of their tumors via the endoscopic, endonasal approach); two giant petroclival meningiomas were debulked with 63 and 89% resection, respectively. All patients experienced resolution or improvement of visual symptoms. No patient experienced permanent worsening of vision after surgery. Only one (3%) patient without preoperative endocrine dysfunction experienced a new, permanent pituitary deficit, diabetes insipidus. One (3%) patient experienced a new neurological deficit after experiencing a hemorrhage 3 weeks after surgery. The postoperative cerebrospinal fluid leak rate was 40% (14 of 35) and varied by tumor location. All leaks were resolved without craniotomy. There were no cases of bacterial meningitis. One patient developed a superinfection of a sterile granuloma from a sinusitis 2 years after surgery. There were two cases of deep venous thrombosis and one pulmonary embolus. There were no operative or perioperative deaths. CONCLUSION Cranial base meningiomas can be successfully managed via a purely endoscopic endonasal approach with acceptable morbidity and mortality rates. The extent of resection is guided by patient factors and symptoms, not by approach. This series had a high cerebrospinal fluid leak rate. With the evolution of new reconstruction techniques, these rates have been substantially reduced.

ENDOSCOPIC ENDONASAL RESECTION OF ANTERIOR CRANIAL BASE MENINGIOMAS

The endonasal route may be feasible for the resection of anterior cranial base tumors that abut the paranasal sinuses. There are several case reports and mixed case series discussing this approach. Other than pituitary adenomas, there is a lack of literature describing the outcomes of endonasal approaches for single-tumor types such as meningiomas. In this study, we describe our current endoscopic endonasal technique and demonstrate the feasibility of using it to access anterior cranial base meningiomas from the back wall of the frontal sinus to the sella and laterally to the region of the midorbit. After this discussion, which includes key technical considerations and nuances, we address safety and efficacy by reporting the outcomes of our early experience with endoscopic endonasal resection of 35 anterior cranial base meningiomas. A total of 35 patients underwent endoscopic endonasal resection of anterior cranial base meningiomas from October 2002 to October 2005. Degree of resection by tumor location was as follows: 10 of the 12 (83%) patients with olfactory groove meningiomas planned for complete resection underwent gross total (seven of 12) or near-total (>95%) (three of 12) resection (67% of all 15 olfactory tumors); 12 of 13 patients (92%) with tuberculum meningiomas underwent gross (11 of 13) or near (>95%) (one of 13) total resection; five patients diagnosed with petroclival meningiomas had successful resection of the parasellar portion of their tumors with relief of visual symptoms (no patients underwent complete resection of their tumors via the endoscopic, endonasal approach); two giant petroclival meningiomas were debulked with 63 and 89% resection, respectively.All patients experienced resolution or improvement of visual symptoms. No patient experienced permanent worsening of vision after surgery. Only one (3%) patient without preoperative endocrine dysfunction experienced a new, permanent pituitary deficit, diabetes insipidus. One (3%) patient experienced a new neurological deficit after experiencing a hemorrhage 3 weeks after surgery. The postoperative cerebrospinal fluid leak rate was 40% (14 of 35) and varied by tumor location. All leaks were resolved without craniotomy. There were no cases of bacterial meningitis. One patient developed a superinfection of a sterile granuloma from a sinusitis 2 years after surgery. There were two cases of deep venous thrombosis and one pulmonary embolus. There were no operative or perioperative deaths. Cranial base meningiomas can be successfully managed via a purely endoscopic endonasal approach with acceptable morbidity and mortality rates. The extent of resection is guided by patient factors and symptoms, not by approach. This series had a high cerebrospinal fluid leak rate. With the evolution of new reconstruction techniques, these rates have been substantially reduced.

Outcomes following endoscopic, expanded endonasal resection of suprasellar craniopharyngiomas: a case series

Craniopharyngiomas are challenging tumors that most frequently occur in the sellar or suprasellar regions. Microscopic transsphenoidal resections with various extensions and variations have been performed with good results. The addition of the endoscope as well as the further expansion of the standard and extended transsphenoidal approaches has not been well evaluated for the treatment of this pathological entity. The authors performed a retrospective review of all patients who underwent a purely endoscopic, expanded endonasal approach (EEA) for the resection of craniopharyngiomas at their institution between June 1999 and February 2006. Endocrine and ophthalmological outcomes, extent of resection, and complications were evaluated. Sixteen patients underwent endoscopic EEA for the resection of craniopharyngiomas. Five patients (31%) presented with recurrent disease. Complete resection was planned in 11 of the 16 patients. Three elderly patients with vision loss underwent planned debulking, 1 patient with vision loss and a moderate-sized tumor had express wishes for debulking, and 1 patient had a separate, third ventricular nodule that was not resected. Of those in whom complete resection was planned, 91% underwent near-total (2/11) or gross-total (8/11) resection. No patient who underwent gross-total resection suffered a recurrence. The mean follow-up period was 34 months. Of the 14 patients who presented with vision loss, 93% had improvement or complete recovery and 1 patient's condition remained stable. No patient experienced visual worsening. Eighteen percent of patients (without preexisting hypopituitarism) developed panhypopituitarism and 8% developed permanent diabetes insipidus. There were no cases of new obesity. The postoperative cerebrospinal fluid leak rate was 58%. All leaks were resolved, and there were no cases of bacterial meningitis. There was 1 vascular injury (posterior cerebral artery perforator branch) resulting in the only new neurological deficit. No patient died. Endoscopic EEA for the resection of craniopharyngiomas provides acceptable results and holds the potential to improve outcomes.

EXTENDED ENDOSCOPIC ENDONASAL TRANSSPHENOIDAL APPROACH FOR THE REMOVALOF SUPRASELLAR TUMORS

The widespread use of the endoscope in transsphenoidal pituitary surgery has recently contributed to the extension of the approach beyond the tuberculum sellae and planum sphenoidale for the management of lesions located in the suprasellar area, either with an endoscope-assisted or purely endoscopic technique. Based on our previous experience with more than 450 standard endoscopic transsphenoidal operations, we have retrospectively evaluated the effectiveness of the extended endoscopic endonasal transsphenoidal approach in the management of lesions mainly located in the suprasellar area. Between January 2004 and December 2005, 20 consecutive patients underwent extended endoscopic endonasal transsphenoidal surgery for a total of 21 procedures. The series consisted of seven pituitary adenomas, seven craniopharyngiomas, three suprasellar Rathke's cleft cysts, two tuberculum sellae meningiomas, and one pilocytic astrocytoma of the chiasm. Tumor removal, as assessed by postoperative magnetic resonance imaging, revealed complete removal of the lesion in four out of seven pituitary adenomas, five out of seven craniopharyngiomas, three out of three Rathke's cleft cysts, and two out of two tuberculum sellae meningiomas. One patient (5%) with craniopharyngioma had a postoperative cerebrospinal fluid leak that required reoperation. The same patient experienced a sphenoid mycosis, which was treated with medical therapy. Some specific conditions associated with the anatomy of the surgical route, as well as to the morphology of the lesion, have resulted to condition the feasibility of the approach. Small and medium sized suprasellar lesions located in the midline, with or without a limited parasellar extension and without involvement of vascular structures, seem amenable to be resected through such extended endoscopic transsphenoidal approach. Improvements in closure techniques and the use of new materials and surgical glues seem to significantly reduce the postoperative cerebrospinal fluid leak rate and meningitis.

Prevention and Management of Cerebrospinal Fluid Leak Following Vestibular Schwannoma Surgery

Postoperative cerebrospinal fluid (CSF) leak is reported in 2% to 30% of cases following vestibular schwannoma surgery. The authors' current surgical techniques for translabyrinthine, retrosigmoid transmeatal, and middle cranial fossa approaches have evolved from analysis of their prior experience in an effort to minimize their complication rate. The authors evaluated the efficacy of their current surgical technique in decreasing the postoperative CSF leak rate. Retrospective review. The vestibular schwannoma database from the New York University Medical Center (New York, NY) neurotological service was reviewed. Data were extracted for type of approach, tumor size, and CSF leak rate. Liberal leak criteria were used. Surgical techniques and management of CSF leak were reviewed. Data from 215 patients who had surgery from 1995 to 2000 manifested a 6.6% CSF leak rate for primary surgeries. This compared favorably with the authors' 17% overall CSF leak rate in 555 total primary surgeries performed between 1979 and 1995. Translabyrinthine closure was performed with dural sutures used as a sling across the posterior fossa dura and abdominal fat placed as a series of corks through the sutures. Abdominal fat was used to obliterate the mastoid cavity in conjunction with aditus and mastoid obliteration. Attention must be paid to soft tissue obliteration of potentially open air cell tracts. Retrosigmoid transmeatal closure was performed with a soft tissue graft in the internal auditory canal drill-out held in position by a "saloon-door" dural flap. Bone wax was used to block perimeatal cells in all cases. Watertight dural closure was achieved with a sutured temporalis fascia graft. Abdominal fat obliteration of the mastoidectomy cavity was performed with an additional firm pressure from the "Palva" periosteal flap. Middle cranial fossa closure was performed with attention to potential air cell tracts of the internal auditory canal drill-out, as well as abdominal fat graft, tissue glue, and bone wax. Fibrin glue was used in all approaches to temporarily secure fat in situ. Management of CSF leaks starts with nonoperative measures including bed rest, oversewing of incisional wounds, and placement of a lumbar subarachnoid spinal fluid diversion drain. If these conservative measures fail, repeat exploration is necessary and is directed at identifying and corking the cell or cells (usually perimeatal or perilabyrinthine) opening directly into the posterior fossa. Evolution in surgical techniques, with particular attention to exposed air cell tracts, abdominal fat graft, and Palva periosteal flap for closure, has had a significant effect in decreasing the author's CSF leak rate after vestibular schwannoma surgery. Conservative management was successful in approximately 50% of cases. Repeat exploration, when needed, was directed at blocking the air cell tract (usually perimeatal or perilabyrinthine) responsible for the CSF leak.

Technique to prevent post-operative CSF leak in the translabyrinthine excision of vestibular schwannoma.

Cerebrospinal fluid (CSF) leak following VS removal is a challenging complication. With experience, it can be seen that anatomical factors such as the extent of pneumatization of the petrous temporal bone and posterior wall of the internal auditory canal play an important role in contributing to CSF leak. Nevertheless, the risk of post-operative CSF leak remains a major concern for both the surgeon and patient. This paper describes a technique, which we have used since 1994, and which has helped us to achieve the lowest reported rate of post-operative CSF leak in translabyrinthine excision of vestibular schwannoma in the world literature.