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

Endoscopic Endonasal Transplanum-Transtuberculum Approach for Pituitary Adenomas/PitNET: 25 Years of Experience

The role of the endoscopic transplanum-transtuberculum approach (ETTA) in the treatment of pituitary adenomas/PitNETs (PAs) is sparsely analyzed in the literature, and its use is still debated in the current practice. The aim of this study was to report our experience with this approach. Our institutional registry was retrospectively reviewed, and patients who underwent ETTA for a PA from 1998 to 2022 were included. Fifty-seven cases were enrolled over a time span of 25 years, corresponding to 2.4% of our entire PA caseload. Radical resection was achieved in 57.9% of cases, with re-do surgery (p = 0.033) and vessel encasement/engulfment (p < 0.001) as predictors of partial resection. CSF leak incidence stood at 8.8%, with higher BMI (p = 0.038) as its only significant predictor. Partial or full improvement of the visual field deficits was achieved in 73.5% of cases. No surgical mortality was observed. According to our results, ETTA for the treatment of PAs is characterized by a satisfactory surgical outcome but with greater morbidity than the conventional endoscopic approach. Therefore, it should be reserved for the few selected cases otherwise unsuitable for the endoscopic trans-sphenoidal route, representing a valid alternative and an effective complementary route for the transcranial approach for these challenging PAs.

Formal Closure of Endoscopic Endonasal Skull Base Defects With a "Bow Tie" Tri-Layer Graft

OBJECTIVE

Risk factors for a postoperative cerebrospinal fluid leak (CSF) after surgery include an intraoperative high flow of CSF, elevated body mass index, defect size, and defect site. In our prior series, a high postoperative CSF leak rate for tumors of the central skull base (planum, sella, and clivus) appeared to be due to graft migration. We changed our closure technique from a single layer of collagen +/- fat graft to a novel graft, termed a "Bow tie" (a tri-layer fat graft with two pieces of collagen matrix), and report our results in this study.

METHODS

Retrospective temporal epoch study of a single otolaryngologist's experience of closing skull base defects in our skull base center from 2005 to 2017.

RESULTS

One hundred and forty-nine patients met inclusion criteria in two time periods, pre- and post-introduction of the Bow tie technique. In epoch I, from 2005 to 2013, 79 patients had reconstruction with a single layer of dural graft (25 had additional free fat graft). In epoch II, from 2014 to 2017, 70 patients had reconstruction with the Bow tie.

RESULTS

CSF leak rates were 8.7% overall: 15.2% in epoch I and 1.4% in epoch II (p = 0.01). After controlling the procedure, defects with a size greater than 2 cm had a 5.7 greater likelihood of failure. Epoch II had a lower incidence of major complications.

CONCLUSION

Using a single surgeon's experience, the multilayer Bow tie has a significant reduction in postoperative CSF leak and associated major complications for defects of the central skull base.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:1568-1575, 2023.

Postoperative protocols following endoscopic skull base surgery: An evidence-based review with recommendations

BACKGROUND

Postoperative management strategies for endoscopic skull base surgery (ESBS) vary widely because of limited evidence-based guidance.

METHODS

The PubMed, EMBASE, and Cochrane databases were systematically reviewed from January 1990 through February 2022 to examine 18 postoperative considerations for ESBS. Nonhuman studies, articles written in a language other than English, and case reports were excluded. Studies were assessed for levels of evidence, and each topic's aggregate grade of evidence was evaluated.

RESULTS

A total of 74 studies reporting on 18 postoperative practices were reviewed. Postoperative pain management, prophylactic antibiotics, and lumbar drain use had the highest grades of evidence (B). The literature currently lacks high quality evidence for a majority of the reviewed ESBS precautions. There were no relevant studies to address postoperative urinary catheter use and medical intracranial pressure reduction.

CONCLUSION

The evidence for postoperative ESBS precautions is heterogeneous, scarce, and generally of low quality. Although this review identified the best evidence available in the literature, it suggests the urgent need for more robust evidence. Therefore, additional high-quality studies are needed in order to devise optimal postoperative ESBS protocols.

Differences in the predicted nasoseptal flap length among races: A propensity score matching analysis

OBJECTIVES

We compared the lengths of a nasoseptal flap (NSF) and skull base according to race, age, and sex.

METHODS

We performed paranasal sinus computed tomography in 19,961 adult patients between 2003 and 2022. The race of the patients was East Asian (n = 71), Caucasian (n = 71), or Middle Eastern (n = 71). The expected lengths of the NSF and anterior skull base defect were measured and analyzed according to race, age, and sex.

RESULTS

Compared with Caucasians and Middle Easterners, East Asians had a shorter NSF length (p < 0.001) and lower ratio of the expected NSF length to the expected defect length (p < 0.001). There was no difference in the values among age groups. The expected NSF length was longer, and the ratio of the expected NSF length to the expected defect length was higher, in males than females (p < 0.001 for both).

CONCLUSIONS

East Asians and females had a shorter NSF length and lower ratio of expected NSF to surgical defect lengths after anterior skull base reconstruction compared with the other races and with males, respectively. Anatomical differences should be considered when long NSF lengths are required, such as for anterior skull base reconstruction.

Factors Influencing Cerebrospinal Fluid Leaking following Pituitary Adenoma Transsphenoidal Surgery: A Meta-Analysis and Comprehensive Review

Background

Surgical resection is the main method to treat pituitary adenoma. Cerebrospinal fluid leakage (CSF Leak) is the main complication after transsphenoidal surgery. The impact of postoperative CSF Leak can be predicted in advance, and preventive measures can be taken in time. Clinically, a variety of factors may affect the occurrence of postoperative CSF Leak. In this study, meta-analysis was used to investigate the risk factors of postoperative CSF Leak as a clinical reference.

Methods

The databases PubMed, Medline, Embrase, Cochrane library, CNKI, and CBM were searched for all studies on the risk factors of postoperative CSF Leak. Studies were screened and finally included. The quality of the included studies was assessed by the Newcastle-Ottawa scale. We used Revman 5.4 software to conduct the pooled effect size of every potential statistically significant factor.

Results

13 articles with a total of 5967 patients with pituitary adenoma and 405 cases of postoperative CSF Leak were finally included, accounting for 6.79%. All of the 13 articles had a quality score > 5, indicating good quality. Meta-analysis showed that patient age (OR = 0.71, 95% CI (0.41, 1.20), P = 0.20) was not a factor influencing postoperative CSF Leak, while BMI (MD = 2.26, 95% CI (1.31, 3.20), P < 0.00001), tumor size (MD = 1.35, 95% CI (0.22, 2.49), P = 0.02), whether a second operation was performed (OR = 2.20, 95% CI (1.45, 3.33), P = 0.0002), and intraoperative CSF Leak (OR = 8.88, 95% CI (3.64, 21.69), P < 0.00001) were risk factors for postoperative CSF Leak in patients. Discussion. BMI, tumor size, reoperation, and intraoperative CSF Leak are the risk factors of postoperative CSF Leak. However, not all the factors were covered in this study, it is still worth continuing to deeply investigate in this topic.

The Posterior Septal Nasal Floor Mucosal Flap for Cranial Base Reconstruction

OBJECTIVE

While pedicled intranasal flaps, such as the nasoseptal flap (NSF), successfully reduce postoperative CSF leaks following endoscopic endonasal approaches (EEA) to the skull base, morbidity remains prevalent. This study describes the first cadaveric description and radiographic analysis of the posterior septal nasal floor mucosal flap (PSNF) designed to reduce pedicled nasal flap morbidity. A case series is also detailed.

STUDY DESIGN

Cadaveric dissection, radiographic analysis, and case series.

METHODS

Seven cadaver specimens underwent harvest of the PSNF. PSNF flap dimensions were measured on the thirty deidentified sinus computed tomography (CT) scans. A retrospective case series was performed on the first set of patients who received the PSNF for reconstruction of a sellar base defect. Information concerning complications, symptoms, and the appearance of the flap was recorded from records of the patient's postoperative inpatient stay, 1-week postop visit, and 1-month postop visit.

RESULTS

Cadaver dissection of the PSNF flap demonstrated good arc rotation along its pedicle with ability to cover both sellar and planum defects. Cadaveric flap measurements and CT-derived measurements estimated a mean surface area of 16.7 and 18.3 cm² , respectively. 15 patients underwent reconstruction of a sellar or planum defect using the PSNF technique. Only one CSF leak was encountered postoperatively. Minimal crusting of the flap and donor site was seen 1 month postoperatively.

CONCLUSION

The PSNF flap provides a sizeable pedicled region for reconstruction comparable to other pedicled nasal flaps. Our case series demonstrated good postoperative outcomes without reduced donor site morbidity.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

Skull base repair following endonasal pituitary and skull base tumour resection: a systematic review

PURPOSE

Postoperative cerebrospinal fluid rhinorrhoea (CSFR) remains a frequent complication of endonasal approaches to pituitary and skull base tumours. Watertight skull base reconstruction is important in preventing CSFR. We sought to systematically review the current literature of available skull base repair techniques.

METHODS

Pubmed and Embase databases were searched for studies (2000-2020) that (a) reported on the endonasal resection of pituitary and skull base tumours, (b) focussed on skull base repair techniques and/or postoperative CSFR risk factors, and (c) included CSFR data. Roles, advantages and disadvantages of each repair method were detailed. Random-effects meta-analyses were performed where possible.

RESULTS

193 studies were included. Repair methods were categorised based on function and anatomical level. There was absolute heterogeneity in repair methods used, with no independent studies sharing the same repair protocol. Techniques most commonly used for low CSFR risk cases were fat grafts, fascia lata grafts and synthetic grafts. For cases with higher CSFR risk, multilayer regimes were utilized with vascularized flaps, gasket sealing and lumbar drains. Lumbar drain use for high CSFR risk cases was supported by a randomised study (Oxford CEBM: Grade B recommendation), but otherwise there was limited high-level evidence. Pooled CSFR incidence by approach was 3.7% (CI 3-4.5%) for transsphenoidal, 9% (CI 7.2-11.3%) for expanded endonasal, and 5.3% (CI 3.4-7%) for studies describing both. Further meaningful meta-analyses of repair methods were not performed due to significant repair protocol heterogeneity.

CONCLUSIONS

Modern reconstructive protocols are heterogeneous and there is limited evidence to suggest the optimal repair technique after pituitary and skull base tumour resection. Further studies are needed to guide practice.

Heterogeneity in Outcome Reporting in Endoscopic Endonasal Skull Base Reconstruction: A Systematic Review

Objective  Presently, there are no standards for reporting outcomes of endoscopic endonasal skull base reconstruction (ESBR). This is problematic as a lack of consistent reporting makes synthesizing findings in systematic reviews and meta-analysis challenging. Thus, the aim of this study was to systematically review and describe the patterns of reporting outcomes in ESBR as a foundation for developing reporting guidelines. Study Design  Present study is a systematic review. Methods  Embase, PubMed, CINAHL, Cochrane Library, and Web of Science were searched for all publications with ≥25 patients and a focus on ESBR. The reporting patterns of each study's variables and outcomes were assessed. Results  A total of 112 studies were included in the review. The most commonly reported demographic variables were the number of included patients ( n  = 112, 100%) and types of pathologies treated ( n  = 104, 92.9%). Meanwhile, the most routinely described preoperative variable was history of prior treatment ( n  = 48, 42.9%). Type of reconstruction was a commonly reported intraoperative variable ( n  = 110, 98.2%), though the rate of intraoperative cerebrospinal fluid (CSF) leak was noted in only 76 studies (67.9%). With regard to postoperative outcomes, postoperative CSF leak rate was routinely provided ( n  = 101, 90.2%), but reporting of other surgical complications was more inconsistent. Ultimately, of the 43 variables and outcomes reviewed, a median of 12 (range: 4-22) was reported in each study. Conclusion  There is significant heterogeneity in the outcomes reported in studies relating to ESBR. This highlights the need for the development of standard reporting guidelines to minimize bias and improve interstudy comparability.

Presentation and management of post-operative cerebrospinal fluid leaks after sphenoclival expanded endonasal surgery: A single institution experience

While surgical approaches and techniques of expanded endonasal approach (EEA) surgery have been well described, little data exist regarding management of post-operative cerebrospinal fluid (CSF) leaks. In this study, we examined a surgeon's continuous 12-year experience with failed closure of sphenoclival skull base defects. We conducted a retrospective case series of patients identified with post-operative CSF leaks after EEA of the sphenoclival axis, managed by a single otolaryngologist at a minimally invasive skull base center. Ten out of 326 patients required therapeutic intervention for central skull base defect closure failure. Median time to presentation of CSF leak was 25 days (range 6-542 days). Symptoms included rhinorrhea (n = 7), meningitis (n = 6), and pneumocephalus (n = 1). The majority of patients (7 of 10) were first managed by lumbar drain placement - one of which had resolution of his/her CSF leak. Overall, 9 of 10 patients required endoscopic repair. The majority of the post-operative CSF leaks (9/13, 69.2%) were repaired using a vascularized mucosal flap. There were 3 patients who required a second revision surgery. All CSF leaks were repaired without completely deconstructing the initial repair. Failure sites most frequently occurred outside of the sella (80%), likely reflecting their direct relationship to the intracranial cisterns. Initial operative repair provided definitive treatment in most cases (70%). Correct placement of a vascularized local pedicle-based flap is essential for successful repair. Knowledge of alternative flaps is particularly important when the nasoseptal flap is no longer available.

Managing complications of endoscopic transsphenoidal surgery in pituitary adenomas

INTRODUCTION

Over the last two decades there has been a gradual shift from the traditional microscopic approach toward the use of endoscopic endonasal approach for resection of pituitary adenomas. Multiple medical and surgical complications can occur following endoscopic transsphenoidal resection of adenomas.

AREAS COVERED

We discuss the evolution of the surgical practice from the use of the 'microscope' to the 'endoscope' in the resection of pituitary adenomas. We present a comprehensive review of the medical and surgical complications following surgery with particular emphasis on both the prevention and management of electrolyte disturbance, cerebrospinal fluid leak and the rare but dreaded complication of internal carotid injury (ICA). We also searched the PubMed database to identify relevant literature between 1984 and 2019.

EXPERT OPINION

Use of endoscope compared with microscope may be associated with better preservation of pituitary gland function with similar extent of resection. Overall medical and surgical complications can be safely managed in high volume centers in association with endocrinologists and skull base trained otolaryngologists. Understanding of anatomico-technical nuances and meticulous surgical technique are important toward preventing ICA injury. Ongoing surgical and technical developments coupled with imaging advances will likely lead to better future outcomes for patients with functioning and nonfunctioning adenomas.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Reconstruction of skull base bone defects using an in situ bone flap after endoscopic endonasal transplanum-transtuberculum approaches

PURPOSE

The creation of bone flaps which can be later repositioned and fixed in situ for repairing the bone defects during the endoscopic endonasal approaches (EEAs)-similar to transcranial craniotomies-is still a challenge. We present an in situ bone flap (ISBF) closure for the repair of bone defects after endoscopic endonasal transplanum-transtuberculum approaches (EETAs).

METHODS

A retrospective analysis of consecutive patients who underwent the EETAs between January 2016 and February 2019 was performed. According to whether or not to use ISBF for skull base reconstruction, these patients were divided into the ISBF group or the non-ISBF group.

RESULTS

Of 47 patients in the ISBF group, only one patient (2.1%) developed postoperative cerebrospinal fluid (CSF) leakage, yielding a significantly lower leakage rate in the ISBF group than in the non-ISBF group (6 of 38, 15.8%, P = 0.042). Besides, when only comparing cases of hydrocephalus in the two groups, the CSF leakage rate in the ISBF group was 8.3% (1/12), which was still significantly lower than that in the non-ISBF group (62.5%, 6/8) (P = 0.018). Postoperative CSF leakages in both groups were successfully treated with lumbar drainage alone, and no cases of injury to the internal carotid arteries or optic nerves occurred in either group.

CONCLUSIONS

An ISBF closure similar to transcranial craniotomies with repositioning bone flap in situ-is feasible, safe, and reliable. The ISBF closure combining with a pedicled nasoseptal flap (PNSF) provides the cranial base surgeon with an additional repair method that has demonstrated effectiveness at facilitating a more stable and durable reconstruction and reducing CSF leaks.

Efficacy of simultaneous pericranial and nasoseptal "double flap" reconstruction of anterior skull base defects after combined transbasal and endoscopic endonasal approaches

BACKGROUND

The "double flap" reconstruction technique, comprised of a simultaneous vascularized pedicled pericranial flap (PCF) and pedicled nasoseptal flap (NSF), can be used to repair anterior skull base defects after a combined cranionasal or transbasal-endoscopic endonasal approach (EEA) has been performed to remove malignant anterior skull base tumors. The use of two vascularized flaps may potentially decrease the incidence of post-radiation flap necrosis and postoperative cerebrospinal fluid (CSF) leaks after radiation therapy.

METHODS

We conducted a retrospective review of a prospective skull base database on patients who underwent the double flap reconstruction technique after a combined transbasal-EEA approach. Data collected for each patient included demographics, method of tumor resection and repair, complications, tumor recurrence, and follow-up.

RESULTS

Nine patients who underwent a combined transbasal-EEA approach for resection of anterior skull base tumors with significant intracranial extension followed by reconstruction of the cranial base using the double flap technique. Four were men and five were women, with a mean age of 49 years (range, 15-68 years). There was no postoperative CSF leakage detected or complications of infection, meningitis, mucocele, or tension pneumocephalus after a mean follow-up of 35.7 months (range, 4.5-98 months). Seven of the nine patients underwent adjuvant radiation without flap necrosis. Local tumor recurrence was not observed in any of the patients at last follow-up; however, one patient developed distant brain metastasis.

CONCLUSION

The simultaneous PCF and NSF double flap reconstruction is an effective technique in preventing postoperative CSF leakage and post-radiation necrosis when repairing anterior skull base defects after combined transbasal-EEA approaches. This technique may be useful in patients anticipated to undergo postoperative radiation therapy.

Transclival approaches for intradural pathologies: historical overview and present scenario

Recently, endoscopic transsphenoidal transclival approaches have been developed and their role is widely accepted for extradural pathologies. Their application to intradural pathologies is still debated, but is undoubtedly increasing. In the past five decades, different authors have reported various extracranial, anterior transclival approaches for intradural pathologies. The aim of this review is to provide a historical overview of transclival approaches applied to intradural pathologies. PubMed was searched in October 2018 using the terms transcliv*, cliv* intradural, transsphenoidal transcliv*, transoral transcliv*, transcervical transcliv*, transsphenoidal brainstem, and transoral brainstem. Exclusion criteria included not reporting reconstruction technique, anatomical studies, reviews without new data, and transcranial approaches. Ninety-one studies were included in the systematic review. Since 1966, transcervical, transoral, transsphenoidal microsurgical, and, recently, endoscopic routes have been used as a corridor for transclival approaches to treat intradural pathologies. Each approach presents a curve that follows Scott's parabola, with evident phases of enthusiasm that quickly faded, possibly due to high post-operative CSF leak rates and other complications. It is evident that the introduction of the endoscope has led to a significant increase in reports of transclival approaches for intradural pathologies. Various reconstruction techniques and materials have been used, although rates of CSF leak remain relatively high. Transclival approaches for intradural pathologies have a long history. We are now in a new era of interest, but achieving effective dural and skull base reconstruction must still be definitively addressed, possibly with the use of newly available technologies.

Effect of oxidized cellulose on human respiratory mucosa and submucosa and its implications for endoscopic skull-base approaches

BACKGROUND

Regenerated oxidized cellulose (ROC) sheets have gained popularity as an adjunct to a vascularized nasoseptal flap for closure of dural defects after endoscopic endonasal skull-base approaches (EESBS). However, evidence supporting its impact on the healing process is uncertain. This study was performed to evaluate the impact of ROC on the nasal mucosa and assess its effects on tissue pH, structure, and cell viability.

METHODS

In 5 patients, a 1-cm² piece of ROC gauze was placed on the surface of the middle turbinate before it was resected as part of a standard EESBS. Mucosa treated with ROC was separated from untreated mucosa and a histologic examination of structural changes in the respiratory epithelium was performed. To assess the effect of ROC on pH, increasing amounts of ROC were added to culture medium. Nasal fibroblasts viability was assessed in the presence of ROC before and after the pH was neutralized.

RESULTS

Compared with unexposed controls, treated mucosa exhibited a higher incidence of cell necrosis and epithelial cell detachment. When added to Dulbecco's modified Eagle medium, ROC caused a dose-dependent decrease in pH of the medium. Only 1 ± 0.8% of cultured fibroblasts exposed to the ROC-induced acidic medium were alive, whereas 98.25 ± 0.5% of the cells were viable when the pH was neutralized (p < 0.001).

CONCLUSION

ROC applied in vivo to nasal mucosa induced epithelial necrosis likely by diminishing the medium pH, because pH neutralization prevents its effect. The ultimate effect of this material on the healing process is yet to be determined.

Sphenoid Mucocele: A Complication of Skull Base Reconstruction with Nasoseptal Flap-A Critical Review and Our Experience

The evolution of expanded endoscopic skull base surgery has enabled development of minimally invasive approaches for resection of large skull base tumors with the nasoseptal flap proving to be an indispensable tool in skull base reconstruction. We here present our experience of sphenoid mucocele development after skull base reconstruction with the nasoseptal flap along with a comprehensive review of the limited literature on the same. With the expanding scope of endoscopic skull base surgery, the nasoseptal flap is increasingly being used for reconstruction. Despite adherence to standard recommendations and use of meticulous technique during flap placement, the potential risk of mucocele formation under the flap should always be borne in mind. In our experience, displacement of the flap pedicle could lead to ostial obstruction and mucocele formation. Hence, in addition to meticulous technique, a close follow up of such patients via nasal endoscopy or imaging is important to further our knowledge and understanding of the long-term effects and complications of this flap.

Sellar Defect Reconstruction with Vascularized Superior Turbinate Mucosal Flaps in Endonasal Endoscopic Transsellar Approach

BACKGROUND

The pedicled nasoseptal flap (NSF) constitutes the primary reconstructive option for most skull base defects in endonasal endoscopic approaches. The superior nasal turbinate (ST) has received little attention. We report our preliminary experience with the use of the ST mucosal flap in selected cases.

METHODS

We performed a retrospective review of patients who underwent endonasal endoscopic approaches and identified 9 patients who were reconstructed with vascularized ST mucosal flaps as part of a double-layer or triple-layer reconstruction. When there was no intraoperative cerebrospinal fluid (CSF) leak, we used a double-layer technique. If there was an intraoperative CSF leak, regardless of the quality of leakage, we preferred a triple-layer repair technique. In patients with high-flow leaks, triple-layer repair was performed using only autologous tissue grafts and flaps.

RESULTS

Intraoperative CSF leaks were noted in 7 of 9 patients. Among them, 4 patients had low-flow CSF leaks (grade 1 and 2) and 3 patients had high-flow CSF leaks (grade 3). All reconstructions had complete defect coverage with the ST flaps and NSFs were preserved. All the flaps were viable at 4 weeks without a CSF leak or complication at the reconstruction site. There was no contraction or partial loss of the flap. After a mean follow-up period of 9 months, none of the patients required a flap revision, developed a mucocele, infection, or other complication.

CONCLUSIONS

An ST flap can be used for the vascularized reconstruction of sellar defects if it is bilaterally available. This option should not be overlooked and wasted.

A Stratified Algorithm for Skull Base Reconstruction With Endoscopic Endonasal Approach

The authors presented our institutional experience with skull base reconstruction techniques and developed a stratified algorithm for different causes of cerebrospinal fluid (CSF) leak. This is a retrospective review of patients who were diagnosed as CSF leak treated with skull base reconstruction or who underwent endoscopic transsphenoidal surgery for sellar and parasellar lesions at our department from August 2012 to April 2017. The authors totally identified 57 (59 operations in total) patients who were divided into 3 groups according to the causes of CSF leak and different reconstruction techniques. All patients underwent skull base reconstruction with specific focus on diagnosis, reconstruction techniques and strategies, and clinical outcome. The reconstruction technique we adopted was the classical multiple-layer technique, as known as "sandwich" technique, with combination of fat tissue, septal bone, autologous fascia lata, artificial dura, and nasoseptal flap (NSF). The NSF was selectively harvested for large defects according to our protocol. The reconstruction failure rate is 4.4% (2 of 45) in patients underwent endoscopic surgery for sellar and parasellar lesions. Reconstruction for postoperative iatrogenic, traumatic, and spontaneous CSF leak achieved 100% success rate; 54.2% (32 of 59) operations were done with "sandwich" plus NSF. The overall failure rate of all reconstructions was 3.4% (2 of 59). A stratified approach with multiple-layer technique and NSF is reliable for skull base reconstruction.

The Role of the Lumbar Drain in Endoscopic Endonasal Skull Base Surgery: A Retrospective Analysis of 811 Cases

OBJECTIVE

With increasing use of the endoscopic endonasal transsphenoidal approach, wider attention is being paid to treatment and prevention of its complications. The aim of this study was to determine whether lumbar drainage (LD) has been effective in preventing and treating postoperative cerebrospinal fluid (poCSF) leakage or in assisting in achieving tumor gross total removal (GTR).

METHODS

Retrospective analysis of purely endoscopic endonasal transsphenoidal cases at a single center between 2008 and 2017 was done. We studied intraoperative cerebrospinal fluid (ioCSF) and poCSF leakage rates, duration of hospitalization, and GTR rate of the lesions, comparing patients with and without LD.

RESULTS

Among 811 endoscopic endonasal transsphenoidal procedures, LD was used in 38 cases. There was no statistically significant difference between patients with and without LD with regard to incidence of ioCSF leakage. A statistically significant difference was found in obese patients with LD, who had an apparently increased rate of poCSF leak. The length of stay of patients with LD was significantly longer than the control group without LD. The GTR rate was also higher in patients without LD.

CONCLUSIONS

Use of LD is correlated with longer immobilization and hospitalization without providing statistically significant advantages in terms of prevention or treatment of ioCSF and/or poCSF in low-risk and high-risk patients. Moreover, LD was not helpful in achieving GTR of tumors.

Relaxing Sphenoidal Slit Incision to Extend the Anterior and Posterior Reach of Pedicled Nasoseptal Flaps During Endoscopic Skull Base Reconstruction of Transcribriform Defects: Technical Note and Results in 20 Patients

BACKGROUND

Reconstruction of large anterior skull base (ASB) defects after an endoscopic endonasal transcribriform approach (EEA-TC) remains a challenge despite the advent of the vascularized pedicled nasoseptal flap (PNSF).

OBJECTIVE

We describe a relaxing PNSF slit incision that extends the anterior and posterior reach of the PNSF to maximize tensionless flap coverage of transcribriform ASB defects.

METHODS

A retrospective chart review was conducted on 20 consecutive patients who underwent endoscopic endonasal transcribriform approach and subsequent PNSF reconstruction with a relaxing slit incision. At the time of endoscopic ASB reconstruction, the PNSF is rotated into position so that the anterior margin of the flap is situated at the posterior table of the frontal sinus. A relaxing slit incision is made across the sphenoidal segment of the PNSF, which is the segment of flap that bridges across the sphenoid sinus once the flap is rotated into position. The anterior reach of the flap is increased to adequately cover the posterior table of the frontal sinus, and the redundant sphenoidal flap is rotated posteriorly to make contact to the bony planum sphenoidale.

RESULTS

No patients developed postoperative cerebrospinal fluid leaks (0%). The ASB repair was monitored via postoperative outpatient nasal endoscopy at various time points, which demonstrated excellent mucosalization of the ASB with a mean follow-up of 19.2 months (range: 4.1-36.2 months).

CONCLUSIONS

Our simple relaxing slit incision in the sphenoidal portion of the PNSF allows for maximal tensionless coverage of extensive transcribriform defects by increasing the anterior and posterior reach of the flap.

Management of Skull Base Defects After Surgical Resection of Sinonasal and Ventral Skull Base Malignancies

Over the past 2 decades, there has been a significant increase in the resection of larger and more complex ventral skull base malignancies. The resection of these lesions has resulted in the creation of larger and more difficult to repair skull base defects. There are many available options for ventral skull base reconstruction. Despite the variety of reconstructive options, the key objective is to eliminate any communication between the intracranial space and the sinonasal cavity. This article discusses some of the more common techniques currently used for repair of these skull base defects.

Endoscopic Resection of Clival Malignancies

Surgical management of clival lesions presents numerous therapeutic challenges because of the close proximity of surrounding critical structures. With a detailed understanding of the endoscopic endonasal approach and relevant considerations, appropriate lesions can be removed in a safe and minimally invasive manner. Use of this technique as a primary approach represents the standard of care for many lesions at leading skull base centers, although adjunct techniques may be necessary in extensive lesions and those with significant lateral extension.

Nasoseptal Flap Elevation in Patients with History of Septal Surgery: Does It Increase Flap Failure or Cerebrospinal Fluid Leakage?

OBJECTIVE

The nasoseptal flap (NSF) has been shown to be a mainstay in the reconstruction of skull base defects. We evaluated the efficacy and complications of NSF in patients with a history of septal surgery who had the potential risk of tearing and poor vascularity.

METHODS

We performed a retrospective chart and video review of patients who underwent NSF for skull base reconstruction between February 2012 and May 2015. Comparison was made between 18 patients (revision group) who had a history of septoplasty and/or transseptal transsphenoidal approach and 88 patients (primary group) without a history of septal surgery. Laceration when raising the flap, vascularity on postoperative magnetic resonance imaging, viability on postoperative endoscopy, and cerebrospinal fluid (CSF) leakage were compared between the revision and primary groups.

RESULTS

Laceration of the flap occurred during NSF elevation in 2 patients (11.1%) in the revision group and 4 patients (4.5%) in the primary group (P = 0.269). Poor flap vascularity on magnetic resonance imaging was observed in 2 patients (11.1%) in the revision group and 8 patients (9.1%) in the primary group (P = 0.674). The rate of flap necrosis on endoscopy was 5.6% in the revision group and 1.1% in the primary group (P = 0.312). There was no significant difference in CSF leakage rate between the 2 groups (revision 5.6% and primary 10.2%).

CONCLUSIONS

There was no difference in rate of CSF leakage or flap integrity between the 2 groups. Therefore, NSF for skull base reconstruction is feasible in patients with a history of septal surgery.

Endoscopic Endonasal Approach for Olfactory Groove Meningiomas: Operative Technique and Nuances

Olfactory groove meningiomas represent approximately 10% of all intracranial meningiomas. Because these tumors originate at the ventral skull base, the endonasal route provides direct access to the tumor blood supply for early devascularization and removal of the underlying hyperostotic bone at the cranial base. In carefully selected patients, these tumors can be totally removed without additional brain retraction or manipulation. In this report, we describe the surgical technique and operative nuances for removal of olfactory groove meningiomas using the endoscopic endonasal approach, and also discuss the indications, limitations, complication avoidance and management, and postoperative care.

Variations of mucosal-sparing septectomy for endonasal approach to the craniocervical junction

OBJECTIVES/HYPOTHESIS

Recent advances in surgical techniques have rendered the craniocervical junction (CCJ) accessible transnasally. Endoscopic endonasal transclival and transodontoid approaches are routinely performed in leading skull base centers. Usually, these approaches involve a posterior bony and mucosal septectomy, which may compromise the vascularized pedicled nasoseptal flap (PNSF), a robust reconstructive option for repair of large skull base defects. With the possibility of an intraoperative cerebrospinal fluid leak and the reported success of the PNSF for repair of these defects, preserving the integrity of the PNSF is beneficial during the endoscopic endonasal approach to the CCJ. We describe three new variations/refinements of the endoscopic endonasal approach to the CCJ that preserve the mucosal integrity of the posterior nasal septum and PNSF.

METHODS

Photo and video documentation of cadaveric dissections.

RESULTS

The steps required for the different variations in approaching the CCJ are demonstrated. These three options are: 1) nonopposing Killian incisions with submucosal elevation of PNSFs laterally under the inferior turbinates (the PNSFs are retracted laterally and left attached superiorly onto the nasal septum and laterally under the inferior turbinate); 2) bilateral non-opposing PNSFs tucked beneath their respective middle turbinate or into the sphenoid sinus; and 3) a hybrid approach combining option 1 performed on one side and option 2 on the contralateral side. All three options allowed for a mucosal-sparing septectomy to provide ample access to the CCJ.

CONCLUSION

These variations/refinements of the mucosal-sparing approach to the CCJ allowed adequate surgical access with sufficient maneuverability while preserving both PNSFs.

LEVEL OF EVIDENCE

NA. Laryngoscope, 126:2220-2225, 2016.

Management of cerebrospinal fluid rhinorrhea: an evidence-based review with recommendations

BACKGROUND

Management strategies employed for cases of cerebrospinal fluid (CSF) rhinorrhea vary widely because of limited evidence-based guidance.

METHODS

A systematic review of the literature was performed using PubMed, EMBASE, and Cochrane databases from January 1990 through September 2014 to examine 5 endoscopic repair techniques and 8 perioperative management strategies for CSF rhinorrhea. Benefit-harm assessments, value judgments, and recommendations were made based on the available evidence. Study exclusion criteria were language other than English, pre-1990 studies, case reports, and nonrhinologic leak. All authors agreed on recommendations through an iterative process.

RESULTS

We reviewed 67 studies examining 13 practices pertinent to the management of CSF rhinorrhea, reaching a highest aggregate grade of evidence of B. The literature does not support the routine use of prophylactic antibiotics or lumbar drainage. Various endoscopic repair materials show similar success rates; however, larger defects may benefit from vascularized grafts. There were no relevant studies to address postoperative activity restrictions.

CONCLUSION

Despite relatively low levels of evidence, recommendations for the management of CSF rhinorrhea can be made based on the current literature. Higher-level studies are needed to better determine optimal clinical management approaches.

Schwannomas of the sinonasal tract and anterior skull base: a systematic review of 94 cases

BACKGROUND

Schwannomas of the anterior skull base (ASB) and sinonasal tract are extremely rare. These lesions mimic other pathologies such as olfactory groove meningiomas, hemangiopericytomas, and esthesioneuroblastomas. Because of their low incidence, ASB and sinonasal tract schwannomas have not been well characterized. A systematic review of ASB and sinonasal tract schwannomas was conducted to further elucidate the presentation and surgical management of these lesions.

METHODS

A MEDLINE/PubMed search was performed, identifying 71 articles representing 94 cases of ASB and sinonasal schwannomas. Each case was analyzed for demographics, clinical presentation, anatomic location, radiographic features, and surgical treatment.

RESULTS

In 94 patients with ASB and sinonasal schwannomas, 44 (46.8%) were exclusively sinonasal, 30 cases (31.9%) were exclusively intracranial, 12 (12.8%) were primarily intracranial with extension into the paranasal sinuses, and 8 (8.5%) were primarily sinonasal with intracranial extension. Headaches and nasal obstruction were the most common presenting symptoms occurring in 30.9 and 29.8% of cases, respectively. Magnetic resonance imaging typically showed a hyperintense mass on T2-weighted imaging (70%) and hypointense (41%) on T1-weighted imaging. Most patients underwent surgical gross total resection via craniotomy, endoscopic endonasal approach, rhinotomy, or other sinonasal approaches. Recurrence occurred in three cases ranging from 4 months to 13 years. Postoperative complications included cerebral spinal fluid leakage, bacterial meningitis, epidural hematoma, and pneumocranium.

CONCLUSION

ASB and sinonasal schwannomas are rare lesions and should be considered in the differential diagnosis of ASB masses involving the cribriform plate with sinonasal extension. Gross total resection of these lesions should be considered the goal of operative management.

Impact of Chemoradiotherapy on CSF Leak Repair after Skull Base Surgery

Background Transnasal endoscopic resection (TER) has become the treatment of choice for many skull base tumors. A major limitation of TER is the management of large dural defects and the need for repair of cerebrospinal fluid (CSF) leaks, particularly among patients who are treated with chemotherapy (CTX) or radiotherapy (RT). The objective of this study is to determine the impact of CTX and RT on the success of CSF leak repair after TER. Methods We performed a retrospective chart review of a single-institution experience of TER from 1992 to 2011. Results We identified 28 patients who had endoscopic CSF leak repair after resection of malignant skull base tumors. Preoperative RT was utilized in 18 patients, and 9 had undergone CTX. All patients required CSF leak repair with rotational flaps after cribriform and/or dural resection. CSF leak repair failed in three patients (11%). A history of RT or CTX was not associated with failed CSF leak repair. Conclusion Adjuvant or neoadjuvant CTX or RT is not associated with failed CSF leak repair. Successful CSF leak repair can be performed in patients with malignant skull base tumors with an acceptable risk profile.

Transorbital endoscopic amygdalohippocampectomy: a feasibility investigation

Object

Resection of the hippocampus is the standard of care for medically intractable epilepsy in patients with mesial temporal sclerosis. Although temporal craniotomy in this setting is highly successful, the procedure carries certain immutable risks and may be associated with cognitive deficits related to cortical and white matter disruption. Alternative surgical approaches may reduce some of these risks by preserving the lateral temporal lobe. This study examined the feasibility of transorbital endoscopic amygdalohippocampectomy (TEA) as an alternative to open craniotomy in cadaveric specimens.

Methods

TEA dissections were performed in 4 hemispheres from 2 injected cadaveric specimens fixed in alcohol. Quantitative predictions of the limits of exposure based on predissection imaging were compared with intradissection measurements. The extent of resection and angles of exposure during the dissection and on postdissection imaging were recorded. These measurements were validated with MRI studies from 10 epilepsy patients undergoing standard surgical evaluations.

Results

The transorbital approach permitted direct access to the mesial temporal structures through the lateral orbital wall. Up to 97% of the hippocampal formation was resected with no brain retraction and minimal (mean 6.0 ± 1.4 mm) globe displacement. Lateral temporal lobe white matter tracts were preserved.

Conclusions

TEA permits hippocampectomy comparable to standard surgical approaches without disrupting the lateral temporal cortex or white matter. This novel approach is feasible in cadaveric specimens and warrants clinical investigation in carefully selected cases.

Structural pedicled mucochondral-osteal nasoseptal flap: a novel method for orbital floor reconstruction after sinonasal and skull base tumor resection

Unrepaired orbital floor defects after sinonasal and skull-base tumor resection can lead to herniation of orbital contents into the maxillary or ethmoidal sinuses, possibly resulting in infection and significant cosmetic and functional deficits. Orbital floor defects are usually repaired using prosthetic implants or autogenous material. Nasal septal cartilage has been used previously as a free graft for reconstruction. However, its reliance on local vascular supply can result in ischemia and necrosis in the postoperative period. The vascularized pedicled nasoseptal flap, consisting of mucoperichondrium and mucoperiosteum, is routinely used as an effective reconstruction method for endoscopic repair of cerebrospinal fluid leaks arising from skull base dural defects. However, this flap does not provide rigid structural reconstruction when used alone. We report a case of an orbital floor defect repaired using a pedicled mucochondral-osteal nasoseptal flap. This technique incorporates the structural component of the nasal septal cartilage and bone with the vascularized pedicled nasoseptal flap. This repair technique may be useful in patients requiring postoperative radiotherapy.

Use of the Hadad-Bassagasteguy flap for repair of recurrent cerebrospinal fluid leak after prior transsphenoidal surgery

The Hadad-Bassagasteguy vascularized nasoseptal pedicled flap (HBF) is an effective technique for reconstruction of skull base defects with low incidence of postoperative cerebrospinal fluid (CSF) leak. Advanced planning is required as posterior septectomy during transsphenoidal surgery can preclude its use due to destruction of the vascular pedicle. We present four cases in which the HBF was successfully used to repair recurrent CSF leaks despite prior posterior septectomy and transsphenoidal surgery. A retrospective chart review was performed on all patients who developed recurrent CSF leak after transsphenoidal surgery over a 7-year period (2006–2013). Data were collected regarding demographics, clinical presentation, intraoperative findings, and surgical outcomes. Four patients who developed recurrent CSF drainage after transsphenoidal surgery were managed with HBF reconstruction during the study period. Two were men and two were women with a mean age of 37 years (range, 24–48 years). All had previously undergone resection of a pituitary macroadenoma via a transsphenoidal approach, with intraoperative CSF leaks repaired using multilayered free grafts. Recurrent CSF rhinorrhea arose 0.37–12 months (mean, 2.98 months) after the initial pituitary surgery. Active CSF drainage could be visualized intraoperatively with posterior septal perforations present. The HBF was successfully used in all cases, with no evidence of recurrent CSF leak after a mean follow-up of 2.35 years. The HBF may be salvaged for repair of recurrent CSF leaks even in the context of prior posterior septectomy and transsphenoidal surgery. However, longer follow-up is necessary to determine the long-term efficacy of this procedure in such revision cases.

Modified subtotal-Lothrop procedure for extended frontal sinus and anterior skull-base access: a case series

BACKGROUND

The endoscopic modified Lothrop procedure (EMLP) is well established for resistant frontal sinus disease and anterior skull base (ASB) exposure. However, this technique may be unnecessarily aggressive by removing avoidable sinonasal structures in select cases. Previously, in a cadaveric study, we proposed a modification of the EMLP, termed the modified subtotal-Lothrop procedure (MSLP), to access the ASB and to address complex frontal sinus disease, for which access to the bilateral frontal sinus posterior table is required. This study provides a step-by-step description of this technique, and presents our experience in 5 patients who underwent this approach.

METHODS

A retrospective analysis was performed at a tertiary referral center on all patients undergoing endoscopic ASB resection and complex frontal sinus surgeries between May 2011 and May 2013. Of 8 patients identified who underwent an MSLP, 5 had at least 1-year follow-up.

RESULTS

All patients underwent successful ASB exposure via the MSLP without complications and preservation of one frontal sinus recess. Adequate access to the bilateral posterior frontal sinus table was achieved in all cases. A patent frontal sinus drainage pathway could be assessed endoscopically after a mean follow-up of 18.6 (range, 12-27) months.

CONCLUSION

The MSLP is a feasible approach for exposure of the ASB and accessing complex frontal sinus pathology. This modification provides adequate ASB exposure and surgical maneuverability similar to the EMLP, while preserving one frontal sinus recess. This modification was successful in providing adequate exposure and maneuverability as well as maintaining frontal sinus patency in this small cohort.

One-piece modified gasket seal technique

Objectives Review the effectiveness of a modified gasket seal technique utilizing a porous high-density polyethylene plate/rectus sheath fascia construct without fat grafting for primary closure of anterior defects following endoscopic skull base surgery. Design Retrospective review (2011-2012). Setting Single academic medical center. Methods A retrospective review of five patients who underwent expanded endoscopic endonasal surgery for various pathologies (two craniopharyngiomas, two tuberculum meningiomas, and one planum meningioma) was performed. Skull base closure was performed using a one-piece modified gasket seal technique. Primary outcome measures included postoperative cerebrospinal fluid (CSF) leaks and donor site morbidity. Results There were no postoperative CSF leaks. Two patients experienced aseptic meningitis treated with a 14-day course of steroids. Two patients experienced new postoperative chronic/recurrent sinusitis treated with oral antibiotics and topical nasal therapy. There was no donor site morbidity such as infection, hematoma, or hernias. Conclusions The one-piece modified gasket-seal closure is a safe and effective method for reconstruction of endonasal defects of the anterior skull base. Rectus sheath fascia is an appropriate dural substitute for free tissue grafting with low donor site morbidity. The construction of the one-piece graft significantly decreases operative time and lowers the learning curve for multilayered closure.

A novel technique for pedicled nasoseptal flap takedown in revision skull base surgery

Objective To describe a novel technique of using the CO2 laser for a revision pedicled nasoseptal flap (PNSF) takedown. Patient Patient with a pituitary adenoma recurrence that had undergone an endoscopic skull base resection with a nasoseptal flap repair 3 years prior. Procedure Flap edges and bony defect are examined using an image-guidance probe to identify the full extent of the defect. The CO2 laser fiber is used to incise through to the underlying skull base. The flap is then elevated from its most distal portion toward the pedicle, using the laser to cut adhesions away from the underlying dura. The skull base defect is then repaired with an onlay graft of acellular dermis, then the PNSF. Results The laser was adept at dissecting through mucosa to the underlying bone and at dissecting the underside of the flap from the posterior adhesions and intradural structures safely. Conclusion The novel use of the of the CO2 laser for the flap takedown was very effective at safely making the mucosal cuts and dissecting the flap from the underlying structures. The nasoseptal flap takedown can be a technically challenging procedure that was made easier by the use of the CO2 laser.

Technical nuances in the management of tuberculum sellae and diaphragma sellae meningiomas

Object

Tuberculum sellae meningiomas (TSMs) and diaphragma sellae meningiomas (DSMs) are challenging lesions to treat due to their proximity to neurovascular structures.

Methods

The authors reviewed the medical records of patients who underwent surgical excision of TSMs and DSMs from 1990 to 2013. They also describe the technical strategies used to minimize injury to the optic apparatus, vascular structures, and pituitary stalk.

Results

Twenty-four patients with TSM and 6 patients with DSM were included in the study. Seventy percent of the tumors were large (≥ 5 cm). The pterional approach was employed in most cases. Optic canal involvement was observed in 4 patients. Twenty-one patients (70%) had visual dysfunction before surgery. At follow-up (median 18 months), visual improvement was noted in 10 (47.6%) of 21 patients. Gross-total excision was achieved in 22 patients (91.6%) with TSM and 5 (83.3%) with DSM. At last follow-up, 28 patients (93.3%) had a Glasgow Outcome Scale score of 5. There were no deaths in this series.

Conclusions

Tuberculum and diaphragma sellae meningiomas present a unique subset of tumors due to their location. They can be safely excised with minimal morbidity and mortality using microsurgical techniques. Attention to technical details during surgery leads to greater respectability and superior visual outcome.

Assessment of mucocele formation after endoscopic nasoseptal flap reconstruction of skull base defects

Advances in endoscopic skull base (SB) surgery have led to the resection of increasingly larger cranial base lesions, resulting in large SB defects. These defects have initially led to increased postoperative cerebrospinal fluid (CSF) leaks. The development of the vascularized pedicled nasoseptal flap (PNSF) has successfully reduced postoperative CSF leaks. Mucocele formation, however, has been reported as a complication of this technique. In this study, we analyze the incidence of mucocele formation after repair of SB defects using a PNSF. A retrospective review was performed from December 2008 to December 2011 to identify patients who underwent PNSF reconstruction for large ventral SB defects. Demographic data, defect site, incidence of postoperative CSF leaks, and rate of mucocele formation were collected. Seventy patients undergoing PNSF repair of SB defects were identified. No postoperative mucocele formation was noted at an average radiological follow-up of 11.7 months (range, 3–36.9 months) and clinical follow-up of 13.8 months (range, 3–38.9 months), making the overall mucocele rate 0%. The postoperative CSF leak rate was 2.9%. Proper closure of SB defects is crucial to prevent CSF leaks. The PNSF is an efficient technique for these repairs. Although this flap may carry an inherent risk of mucocele formation when placed over mucosalized bone during repair, we found that meticulous and strategic removal of mucosa from the site of flap placement resulted in a 0% incidence of postoperative mucocele formation in our cohort.

Early harvesting of the vascularized pedicled nasoseptal flap during endoscopic skull base surgery

PURPOSE

The vascularized pedicled nasoseptal flap (PNSF) represents a successful option for reconstruction of large skull base defects after expanded endoscopic endonasal approaches (EEA). This vascularized flap can be harvested early or late in the operation depending on the anticipation of high-flow CSF leaks. Each harvesting technique (early vs. late) is associated with different advantages and disadvantages. In this study, we evaluate our experience with early harvesting of the PNSF for repair of large skull base defects after EEA.

METHODS

A retrospective review was performed at a tertiary care medical center on patients who underwent early PNSF harvesting during reconstruction of intraoperative high-flow CSF leaks after EEA between December 2008 and March 2012. Demographic data, repair materials, surgical approach, and incidence of PNSF usage were collected.

RESULTS

Eighty-seven patients meeting the inclusion criteria were identified. In 86 procedures (98.9%), the PNSF harvested at the beginning of the operation was used. In 1 case (1.1%), the PNSF was not used because a high-flow intraoperative CSF leak was not encountered. This patient had recurrence of intradural disease 8months later, and the previously elevated PNSF was subsequent used after tumor resection.

CONCLUSION

Based on our data, a high-flow CSF leak and need for a PNSF can be accurately anticipated in patients undergoing EEA for skull base lesions. Because of the advantages of early harvesting of the PNSF and the high preoperative predictive value of CSF leak anticipations, this technique represents a feasible harvesting practice for EEA surgeries.

Endoscopic surgery for tuberculum sellae meningiomas: a systematic review and meta-analysis

Recent reports of surgical resection of tuberculum sellae meningiomas through an endoscopic endonasal approach (EEA) have provided an alternative to transcranial approaches in selected cases. However, these published reports have been limited by small sample size from single institutions. We performed a systematic review and meta-analysis to gain insight into potential limitations and benefits of EEA for tuberculum sellae meningiomas. We performed a systematic review of the literature and analyzed pooled data for descriptive statistics on short-term morbidity and outcomes. We compared EEA to transcranial approaches reported during the same time-frame. Six studies (49 patients) met inclusion criteria for EEA. A pooled analysis of transcranial results reported during a similar time period yielded 11 studies (412 patients). There were no differences in rate of gross total resection or peri-operative complications between the two groups. Although the EEA group was associated with higher rates of CSF leak (p < 0.05; OR 3.9; 95 % CI 1.15, 15.75), EEA were also associated with significantly higher rates of post-operative visual improvement compared to transcranial approaches (p < 0.05; OR 1.5; 95 % CI 1.18, 1.82). A systematic review of the small series of EEA for tuberculum sellae meningiomas published to date revealed similar extent of resection and morbidity, but increased post-operative visual improvement compared to transcranial approaches during a similar time period. Long-term follow-up will be needed to define recurrence rates of EEA as compared to transcranial approaches. Cautious use of EEA for the removal of smaller tuberculum sellae meningiomas after formal endoscopic training may be warranted.

Challenges and surgical nuances in reconstruction of large planum sphenoidale tuberculum sellae defects after endoscopic endonasal resection of parasellar skull base tumors

OBJECTIVES/HYPOTHESIS

Endoscopic endonasal transplanum transtuberculum (EETT) resection of parasellar skull base (SB) tumors often results in large SB defects with intraoperative high-flow cerebrospinal fluid (CSF) leaks. Reconstruction of these defects can be challenging because of the large defects size, communication with the suprasellar cistern, and close proximity to the optic nerves and chiasm. Recent studies have postulated that transplanum defects may be associated with increased postoperative CSF leakage. We review our experience with reconstruction of transplanum defects after EETT resection of parasellar SB tumors. Challenges encountered during these repairs and our operative nuances for successful reconstruction are discussed.

METHODS

A retrospective analysis was performed between March 2010 and February 2012 on patients undergoing reconstruction of transplanum defects after EETT resection of parasellar SB tumors. Repair materials, defect sizes, postoperative CSF leakage, postoperative CSF diversion, and demographic data were collected.

RESULTS

Nineteen patients who underwent 22 repairs with a pedicled nasoseptal flap (PNSF) were identified. The mean age was 47.6 years (range, 12-68 years). Average defect size was 5.6 cm(2) (range, 2.2-10.4 cm(2)). Three failed repairs necessitated a revision procedure. All three revisions were successfully reconstructed with the previously used PNSF. The mean follow-up period was 13.5 months (range, 1-26 months). The overall success rate was 86.4% for transplanum defects alone, as compared to 97.0% for our comprehensive PNSF experience in 99 repairs.

CONCLUSION

Repair of large transplanum defects after EETT resection of parasellar SB tumors presents a unique challenge. Using a PNSF along with meticulous multilayer closure may help decrease postoperative CSF leaks.

Celebrating the golden anniversary of anterior skull base surgery: reflections on the past 50 years and its historical evolution

With its inception nearly half a century ago through the pioneering work of Dandy, McLean, and Smith, anterior skull base (ASB) surgery is a relatively young discipline. It became a distinct entity in 1963 when Ketcham popularized the combined transcranial transfacial approach for en bloc resection of tumors of the paranasal sinuses extending into the anterior cranial fossa. However, because these procedures resulted in major morbidities and mortalities, alternative modes of treatment were sought. Since the 1970s, the introduction and promotion of the surgical endoscope by Messerklinger, Stammberger, and Kennedy, commenced the era of endoscopic sinus surgery. Thaler and colleagues described the utility of the endoscope for ASB surgery at the turn of the century. This allowed direct visualization and safer, more accurate removal of tumors. In 2001, Casiano reported the first purely endoscopic endonasal ASB resection, a novel technique that has been adopted by major skull base centers. The success of ASB surgery can be attributed to both the development of the skull base team as well as improvements in surgical techniques, instrumentation, and visualization technology. In this article, we review the historical evolution of ASB surgery as we approach the 50th anniversary since its recognition as a distinct entity.

Salvage endoscopic nasoseptal flap repair of persistent cerebrospinal fluid leak after open skull base surgery

PURPOSE

Persistent cerebrospinal fluid (CSF) rhinorrhea after open skull base surgery can be challenging to manage due to the risk of meningitis, brain abscess, surgical morbidity associated with revision craniotomy, and the lack of available healthy autologous tissue after failure of a pericranial flap. Given the recent success of the vascularized pedicled nasoseptal flap (PNSF) for reconstruction after endoscopic skull base surgery, we have adopted this technique as a salvage method to treat recalcitrant CSF rhinorrhea after previous open skull base surgery in order to avoid revision craniotomy. To our knowledge, use of the PNSF in this setting has not been previously described in the literature.

METHODS

A retrospective analysis was performed on 4 patients who underwent endoscopic endonasal PNSF repair of persistent CSF rhinorrhea after having undergone previous open transcranial skull base operation. Pathologies consisted of one sinonasal anterior skull base squamous cell carcinoma, one recurrent petrosal skull base meningioma, and 2 traumatic gunshot wounds to the head.

RESULTS

All 4 patients underwent successful repair of CSF rhinorrhea without complications using the salvage endoscopic endonasal PNSF technique after a mean follow-up of 21.5 months.

CONCLUSIONS

In patients who have undergone previous open skull base surgery as the primary approach, persistent CSF rhinorrhea can be safely repaired using the vascularized PNSF via an endoscopic endonasal approach. This minimally invasive strategy has the advantage of providing new healthy vascularized tissue for skull base reconstruction while avoiding revision craniotomy.

Assessment of frontal lobe sagging after endoscopic endonasal transcribriform resection of anterior skull base tumors: is rigid structural reconstruction of the cranial base defect necessary?

OBJECTIVES/HYPOTHESIS

The endoscopic endonasal transcribriform approach (EETA) is a viable alternative option for resection of selected anterior skull base (ASB) tumors. However, this technique results in the creation of large cribriform defects. Some have reported the use of a rigid substitute for ASB reconstruction to prevent postoperative frontal lobe sagging. We evaluate the degree of frontal lobe sagging using our triple-layer technique [fascia lata, acellular dermal allograft, and pedicled nasoseptal flap (PNSF)] without the use of rigid structural reconstruction for large cribriform defects.

STUDY DESIGN

Retrospective analysis.

METHODS

Nine patients underwent an EETA for resection of large ASB tumors from August 2010 to November 2011. The degree of frontal lobe displacement after EETA, defined as the ASB position, was calculated based on the most inferior position of the frontal lobe relative to the nasion-sellar line defined on preoperative and postoperative imaging. A positive value signified upward displacement, and a negative value represented inferior displacement of the frontal lobe.

RESULTS

The average cribriform defect size was 9.3 cm(2) (range, 5.0-13.8 cm(2) ). The average distance of postoperative frontal lobe displacement was 0.2 mm (range, -3.9 to 2.9 mm) without any cases of significant brain sagging. The mean follow-up period was 10.1 months (range, 4-19 months). There were no postoperative CSF leaks.

CONCLUSIONS

Rigid structural repair may not be necessary for ASB defect repair after endoscopic endonasal resection of the cribriform plate. Our technique for multilayer cranial base reconstruction appears to be satisfactory in preventing delayed frontal lobe sagging.