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

Endoscopic endonasal approach for olfactory groove meningioma resection: Strategies and outcomes in a retrospective case series

OBJECTIVE

Though the endoscopic endonasal approach (EEA) is a widely accepted treatment for skull base tumors, the specific use of EEA for olfactory groove meningiomas (OGMs) is debated, with variable outcomes reported in the literature. We review the surgical results of OGM resections for one surgeon including the operative approach, surgical nuances, and outcomes, with a focus on factors relating to patient selection which favor EEA over transcranial approaches.

METHODS

We retrospectively reviewed thirteen cases of endoscopic endonasal resection of olfactory groove meningiomas. Patient characteristics, clinical characteristics, surgical outcomes, and complications were analyzed. Extent of resection was determined based on volumetric analysis of pre- and postoperative MRI.

RESULTS

Anatomic characteristics that render a tumor difficult to access fully are lateral extension beyond the mid-orbit and anterior extension to the falx. Simpson Grade I resection was achieved in 11/13 (84.6 %) cases. Mean pre-operative tumor volume was 8.99 cm3 (range 2.19-16.79 cm3), and 92 % of tumors were WHO grade I. We demonstrate 2 cases of smell preservation, possible with small unilateral tumors and tumors that are confined to either the anterior or posterior portion of the cribriform plate. The post-operative CSF leak rate was 7.7 %, without prophylactic lumbar CSF drainage. The mortality rate was 7.7 % (n = 1) after infectious complications following CSF leak.

CONCLUSIONS

Endoscopic endonasal resection of olfactory groove meningiomas is an effective and safe operative method with outcomes and complication rates comparable to transcranial approaches. Key considerations include careful patient selection and familiarity with technical nuances of endoscopic endonasal approach for this specific tumor type.

Closure strategy for endoscopic pituitary surgery: Experience from 3015 patients

Introduction

Effective strategies are required to ensure optimal management of the crucial closure step in endoscopic pituitary surgery. Many surgical techniques have been reported but no significant consensus has been defined.

Methods

Between January 2006 and March 2022, 3015 adult patients with pituitary adenomas were operated on by a single expert neurosurgical team, using a mononostril endoscopic endonasal approach. Based of preoperative risk factors of and operative findings, a detailed closure strategy was used. Body mass index >40, sellar floor lysis, number of surgeries>2, large skull base destruction, prior radiotherapy were considered as preoperative risk factors for closure failure. All patients treated with an expanded endonasal approach were excluded.

Results

Patients were mostly women (F/M ratio: 1.4) with a median age of 50 (range: 18 -89). Intraoperative CSF leak requiring specific surgical management was observed in 319/3015 (10.6%) of patients. If intraoperative leak occurred, patients with predictive risk factors were managed using a Foley balloon catheter in case of sellar floor lysis or BMI>40 and a multilayer repair strategy with a vascularized nasoseptal flap in other cases. Postoperative CSF leak occurred in 29/3015 (1%) of patients, while meningitis occurred in 24/3015 (0.8%) of patients. In patients with intraoperative leak, closure management failed in 11/319 (3.4%) of cases.

Conclusion

Based on our significant 16-year experience, our surgical management is reliable and easy to follow. With a planned and stepwise strategy, the closure step can be optimized and tailored to each patient with a very low failure rate.

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.

Endoscopic Reconstruction of the Anterior Skull Base Following Tumor Resection: Application of a Novel Bioabsorbable Plate

OBJECTIVE

Endoscopic repair of skull base defects is required following resection of intracranial pathology via the endoscopic endonasal approach (EEA). Many closure techniques have been described, but choosing between techniques remains controversial. We report outcomes of 560 EEA procedures of skull base reconstruction performed on 508 patients over a 15-year-period. Halfway through this period, we adopted the use of a rigid, bioabsorbable extrasellar plate for reconstruction, enabling a comparison between this technique and those used previously.

METHODS

All patients undergoing EEA from 2005 to 2019 at our institution were retrospectively reviewed. Demographic information, surgical pathology, tumor dimensions and radiographic features, reconstructive technique, and patient-related outcomes were collected and analyzed with univariate and multivariate statistical modeling.

RESULTS

Five-hundred sixty procedures were performed on 508 patients. The series complication rate was 8.2%. Overall, cerebrospinal fluid (CSF) leak rate was 5.0% but varied significantly across closure techniques (p < 0.001). Critically, the CSF leak rate in the 272 cases prior to our 2013 adoption of the Resorb-X Plate (RXP) was 8.5%, whereas leak rate in the subsequent 288 cases was 1.7%. RXP was protective against CSF leak (p = 0.001), whereas gross total resection (GTR) correlated with increased leak rate (p = 0.001). Patient BMI was significantly associated with risk of leak (p = 0.047). Other variables did not impact leak risk.

CONCLUSION

Reconstructive technique, extent of resection, and patient BMI significantly contributed to CSF leak rate. GTR was associated with increased leak risk while the RXP was protective. The bioabsorbable RXP is an effective option for rigid skull base repair with comparatively few complications.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:1092-1098, 2023.

Usefulness of endonasal flaps and grafts in skull base surgery. Consensus document

INTRODUCTION

Skull base reconstruction is one of the greatest challenges extended endonasal endoscopic surgery. Many grafts and flaps from the endonasal fossa have been demonstrated to be useful in the control of complications such a cerebrospinal fluid leaks. Review and analysis of these resources are necessary in skull base recontruction to improve outcomes.

OBJECTIVES

The target is to create a consensus document on the use of different endonasal flaps and grafts in the skull base surgery.

MATERIAL AND METHODS

Literature review of the most relevant free grafts and vascularized flaps from the endonasal fossa. Analysis using the Delphi method on the use of the different endonasal resources for endoscopic repair of skull base defects.

RESULTS

We obtained two results: 1) A selection of the most representative flaps and grafts from the endonasal fossa, describing origin, surface and indications, based on a literature review. 2) A consensus document, using Delphi methodology, with general considerations (2), recommendations (10) and limitations (6) of the different endonasal flaps and grafts.

CONCLUSIONS

We present the first consensus document in the field of extended endonasal endoscopic surgery using the Delphi method as a working tool. We highlight the usefulness of the nasoseptal flap together with other endonasal flaps and grafts for skull base reconstruction.

Clinical Impact of Hydroxyapatite on the Outcome of Skull Base Reconstruction for Intraoperative High-Flow CSF Leak: A Propensity Score Matching Analysis

Background

Despite recent advances in skull base reconstructive techniques, including the multilayer technique during the last decade, complete reconstruction of grade 3 intraoperative high-flow cerebrospinal fluid (CSF) leak remains challenging. This study was designed to investigate the role of injectable hydroxyapatite (HXA) used in the multilayer technique on the clinical outcome of skull base reconstruction for intraoperative high-flow CSF leak.

Materials and Methods

This study enrolled 187 patients who experienced intraoperative high-flow CSF leak after endoscopic endonasal surgery for anterior skull base or suprasellar pathologies between January 2014 and July 2021. All skull base defects were reconstructed using the conventional multilayer technique including a vascularized naso-septal flap (NSF, n = 141) and the combined use of HXA with the conventional multilayer technique (HXA group, n = 46). We retrospectively evaluated the efficacy of the HXA group by 1:2 propensity score matching analysis.

Results

Overall, 17 of 187 patients (9.1%) showed postoperative CSF leaks, resulting in second reconstruction surgery. There were no statistical differences in patient age, sex, body mass index, tumor location, tumor type, and degree of resection, except for the follow-up period between the two groups. The HXA group showed a significantly lower incidence of postoperative CSF leak than the control group (0% vs. 12.1%, p < 0.05). Postoperative lumbar drain (LD) was performed in 8.7% of the HXA group compared to 46.1% of the control group (p < 0.01). CSF leak-related infection rates showed a decreasing tendency in the HXA group compared to the control group (0 vs. 7.1%, p = 0.06). A total of 46 patients in the HXA group were well matched with the control group (92 patients) at a 1:2 ratio. In the propensity score-matched control group, there were higher rates of postoperative CSF leaks than in the HXA group.

Conclusion

The use of HXA combined with the conventional multilayer technique completely reduced postoperative CSF leaks in this study. This technique resulted in reduced CSF leakage, even without postoperative LD, and decreased infection rates. Further randomized comparative studies are required to confirm our findings.

Experience and modification of skull base reconstruction results in lower complications rates

OBJECTIVES

To investigate the efficacy of nasal septum bone flap combined with vascularized pedicle nasoseptal flap (VP-NSF) in the treatment of high-flow cerebrospinal fluid (CSF) leakage in the endonasal endoscopic skull base surgery.

METHODS

A total of 156 patients in group A used a multi-layer skull base reconstruction method of fat-absorbable artificial dura mater- fascia lata-VP-NSF, and were treated with drainage of the lumbar cistern after surgery, in addition, a total of 94 patients in group B used a multi-layer skull base reconstruction method of fat-absorbable artificial dura mater-nasal septal bone flap-VP-NSF, and no lumbar cistern drainage was performed after surgery. Analyzed and compared the differences of postoperative cerebrospinal fluid rhinorrhea, intracranial infection, re-repair, average bed rest time, pulmonary infection and deep venous thrombosis of lower extremities were analyzed and compared in the two groups.

RESULTS

In group A, 11 cases of cerebrospinal fluid rhinorrhea occurred after operation. In addition, 15 cases developed intracranial infection. During this period, there were 20 cases of pulmonary infection and 3 cases of deep venous thrombosis of lower extremities. In group B, there were 1 case of cerebrospinal fluid rhinorrhea (P < 0.05), 2 cases of intracranial infection (P < 0.05), 2 cases of pulmonary infection (P < 0.05), and 0 case of deep venous thrombosis of lower extremities (P > 0.05).

CONCLUSION

Nasal septum bone flap combined with VP-NSF is effective in the treatment of high-flow CSF leaks in the endonasal endoscopic skull base surgery, which can avoid postoperative lumbar cistern drainage and is worth popularizing.

The effects of cerebrospinal fluid (CSF) diversion on post-operative CSF leak following extended endoscopic anterior skull base surgery

There is a paucity of high quality evidence regarding the routine placement of lumbar drain (LD) in reducing post-operative (op) cerebrospinal fluid (CSF) leak after extended endoscopic trans-sphenoidal resection of anterior skull base lesions. In this study, we sought to compare the incidence of post-op CSF leak between patients with upfront LD insertion and those without it. This was a prospective randomized controlled trial conducted over a period of 5 years with patients undergoing extended endoscopic trans-sphenoidal surgery randomly assigned to either LD insertion at the time of surgery, or no LD placement. Thirty-eight patients with anterior skull base tumors were accrued from three tertiary hospitals of Melbourne. Post-op leak was confirmed by β2-transferrin-positive rhinorrhea, and/or worsening pneumocephalus on brain imaging. Skull base defect size and pedicled nasoseptal flap viability were assessed on post-op CT and MRI, respectively. There was no significant difference in post-op CSF leak incidence between the two subgroups (12.50% in LD arm vs. 9.10% in no LD arm). Patients with LD insertion however, demonstrated substantially raised complication rates, longer hospital lengths of stay and lower subjective quality of life measures at 12 months compared with those without LD. In conclusion, routine placement of LD at the time of surgery for extended anterior skull base trans-nasal approach did not reduce the risk of post-op CSF leak. Discretion is warranted when using LD as an adjunct due to its associated morbidities, prolonged hospital stay and adverse effect on patients' subjective outcome measures.

Conservative Management of Post-Operative Cerebrospinal Fluid Leak following Skull Base Surgery: A Pilot Study

Background/aims: Iatrogenic CSF leaks after endoscopic endonasal transsphenoidal surgery remain a challenging entity to manage, typically treated with CSF diversion via lumbar drainage. Objective: To assess the safety and efficacy of high-volume lumbar puncture (LP) and acetazolamide therapy to manage iatrogenic CSF leaks. Methods: We performed a prospective pilot study of four patients who developed iatrogenic postoperative CSF leaks after transsphenoidal surgery and analyzed their response to treatment with concomitant high-volume lumbar puncture followed by acetazolamide therapy for 10 days. Data collected included demographics, intra-operative findings, including methodology of skull base repair and type of CSF leak, time to presentation with CSF leak, complications associated with high-volume LP and acetazolamide treatment, and length of follow-up. Results: Mean patient age was 44.28 years, with an average BMI of 27.4. Mean time from surgery to onset of CSF leak was 7.71 days. All four patients had resolution of their CSF leak at two- and four-week follow-up. Mean overall follow-up time was 179 days, with a 100% CSF leak cure rate at the last clinic visit. No patient suffered perioperative complications or complications secondary to treatment. Conclusion: Although our pilot case series is small, we demonstrate that a high-volume LP, followed by acetazolamide therapy for 10 days, can be considered in the management of post-operative CSF leaks.

Sinonasal Packing is Not a Requisite for Successful Cerebrospinal Fluid Leak Repair

Background Numerous methods have been described to repair nasal cerebrospinal fluid (CSF) leaks. Most studies have focused on optimizing CSF leak repair success, leading to closure rates of 90 to 95%.

Objective This study aimed to determine if excellent reconstruction rates could be achieved without using sinonasal packing.

Methods A prospective case series of 73 consecutive patients with various CSF leak etiologies and skull base defects was conducted to evaluate reconstruction success without sinonasal packing. The primary outcome measure was postoperative CSF leak. Secondary outcome measures were postoperative epistaxis requiring intervention in operating room or emergency department, infectious sinusitis, and 22-item sinonasal outcome test (SNOT-22) changes.

Results Mean age was 54.5 years and 64% were female. Multilayered reconstructions were performed in 55.3% of cases, with collagen or bone epidural inlay grafts, and nasal mucosal grafts or nasoseptal flaps for onlay layers. Onlay-only reconstructions with mucosal grafts or nasoseptal flaps were performed in 44.7% of cases. Tissue sealants were used in all cases, and lumbar drains were used in 40.8% of cases. There were two initial failures (97.4% initial success), but both resolved with lumbar drains alone (no revision surgeries). There were no instances of postoperative epistaxis requiring intervention in the operating room or emergency department. Infectious sinusitis occurred in 2.7% of patients in the first 3 months postoperatively. SNOT-22 did not change significantly from preoperatively to first postoperative visits, then improved over time.

Conclusion Nasal CSF leaks from various etiologies and defect sites were successfully repaired without using sinonasal packing, and patients experienced minimal sinonasal morbidity.

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.

Usefulness of endonasal flaps and grafts in skull base surgery. Consensus document

INTRODUCTION

Skull base reconstruction is one of the greatest challenges extended endonasal endoscopic surgery. Many grafts and flaps from the endonasal fossa have been demonstrated to be useful in the control of complications such a cerebrospinal fluid leaks. Review and analysis of these resources are necessary in skull base recontruction to improve outcomes.

OBJECTIVES

The target is to create a consensus document on the use of different endonasal flaps and grafts in the skull base surgery.

MATERIAL AND METHODS

Literature review of the most relevant free grafts and vascularized flaps from the endonasal fossa. Analysis using the Delphi method on the use of the different endonasal resources for endoscopic repair of skull base defects.

RESULTS

We obtained two results: 1) A selection of the most representative flaps and grafts from the endonasal fossa, describing origin, surface and indications, based on a literature review. 2) A consensus document, using Delphi methodology, with general considerations (2), recommendations (10) and limitations (6) of the different endonasal flaps and grafts.

CONCLUSIONS

We present the first consensus document in the field of extended endonasal endoscopic surgery using the Delphi method as a working tool. We highlight the usefulness of the nasoseptal flap together with other endonasal flaps and grafts for skull base reconstruction.

A Comparitive Study of Endoscopic Skull Base Reconstruction in CSF rhinorrea using Nasoseptal Flap with Septal Cartilage v/s Fascia Lata With Fat

The objective of the study is to evaluate the surgical outcome between free nasoseptal mucoperichondrial flap using septal cartilage vs fascia lata using fat in terms of morbidity, hospital stay and postoperative complications. It is a retrospective comparitive study of 127 patients, diagnosed with CSF leak and who underwent repair of anterior skull base defect using free nasoseptal mucoperichondrial graft with septal cartilage in 73 cases compared with fascia lata with fat in 54 cases over the time frame of 5 years. The success rate with free nasoseptal flap with septal cartilage was 97.3% and that with fascia lata with fat was 96.3%. There was a significant association between mean hospital stay and the technique of CSF repair (unpaired t test, p -0.02). In our study the complications following the repair with free nasoseptal flap with septal cartilage was significantly less (p < 0.05, chi square test). The above study concludes that in patients treated with free nasoseptal flap using septal cartilage has less hospital stay, less post-operative morbidity in the form of pain, movement and dependence for cleaning and dressing in comparison to fascia lata using fat.

Combined Transcranial-endonasal Reconstructive Surgery for Cerebrospinal Fluid Leakage Resulting from Traumatic Anterior Skull Base Fractures Involving the Parasellar Region

Extensive traumatic anterior skull base fractures from the frontal sinus to the parasellar region are frequently accompanied by multiple dural defects that cause persistent cerebrospinal fluid (CSF) leakage. Conventional transcranial reconstruction using a frontal periosteal flap is frequently insufficient, and parasellar dural defects are often deep, complex, and difficult to identify. In this report, we describe a combined transcranial–endonasal reconstructive technique and report our experience. Simultaneous combined transcranial and endoscopic surgery was performed in three patients with CSF leakage resulting from traumatic anterior skull base fractures. Dural defects were thoroughly identified from the transcranial and endonasal surgical fields, and covered using a multilayer sealing technique. The anterior regions of the anterior skull base were reconstructed using a free fascial flap and frontal periosteal flap; posterior and parasellar regions were reconstructed using a fat graft, vascularized nasoseptal flap, and endonasal balloon. Suturing the transcranial grafts to the parasellar dura mater was performed collaboratively by the transcranial and endonasal surgeons. In our cases, complete cessation of CSF leakage was achieved without perioperative lumbar drainage in all patients. Mean time to postoperative ambulation was 7 days (range, 3–11). No surgical complications occurred. Simultaneous transcranial and endonasal procedures were helpful to detect all sites of CSF leakage and secure reconstructive grafts. The combined transcranial and endonasal reconstructive technique achieved secure skull base reconstruction without recurrence of CSF leakage, and allowed early postoperative ambulation. This technique can be a reliable surgical option to repair CSF leakage resulting from extensive anterior skull base fractures.

Skull base reconstruction: A question of flow? A critical analysis of 521 endoscopic endonasal surgeries

INTRODUCTION

Post-operative CSF leak still represents the main drawback of Endoscopic Endonasal Approach (EEA), and different reconstructive strategies have been proposed in order to decrease its rate.

OBJECTIVE

To critically analyze the effectiveness of different adopted reconstruction strategies in patients that underwent EEA.

MATERIALS AND METHODS

Adult patients with skull base tumor surgically treated with EEA were retrospectively analyzed. Data recorded for each case concerned patient demographics, type of surgical approach, histotype, anatomical site of surgical approach, intra-operative CSF leak grade (no leak (INL), low flow (ILFL), high flow (IHFL)), reconstructive adopted strategy, Lumbar Drain positioning, post-operative CSF leak rate and intra/post-operative complications.

RESULTS

A total number of 521 patients (January 2012-December 2019) was included. Intra-operative CSF leak grade showed to be associated with post-operative CSF leak rate. In particular, the risk to observe a post-operative CSF leak was higher when IHFL was encountered (25,5%; Exp(B) 16.25). In particular, vascularized multilayered reconstruction and fat use showed to be effective in lowering post-operative CSF leaks in IHFL (p 0.02). No differences were found considering INL and ILFL groups. Yearly post-operative CSF leak rate analysis showed a significative decreasing trend.

CONCLUSION

Intra-operative CSF leak grade strongly affected post-operative CSF leak rate. Multilayer reconstruction with fat and naso-septal flap could reduce the rate of CSF leak in high risk patients. Reconstructive strategies should be tailored according also to the type and the anatomical site of the approach.

Closure of Skull Base Defects after Endonasal Endoscopic Resection of Planum Sphenoidale and Tuberculum Sellae Meningiomas

Background

The expanded endoscopic endonasal transplanum transtuberculum approach allows tumor removal by minimally invasive procedures. A large dural and bone defect is created during the surgical procedure, increasing the risk of postoperative cerebrospinal fluid (CSF) leakage.

Objective

The aim of this study is to describe a surgical technique and complications observed in patients undergoing endonasal resection of planum sphenoidale and/or tuberculum sellae meningiomas.

Methods

A retrospective analysis was performed of patients with planum sphenoidale and/or tuberculum sellae meningiomas after expanded endoscopic endonasal resection between June 2013 and August 2018, in which autologous grafts, fascia lata inlay, and nasoseptal flap onlay were used for closure of skull base defects.

Results

Ten patients were included in the analysis. No cases of postoperative CSF leakages or meningitis were reported, whereas two patients evolved with postoperative infectious complications (fungal ball in right frontal sinus and brain abscess). The skull base defect created for resection measured, on average, 3.58 cm².

Conclusion

Our experience suggests that closure of skull base defects using combined fascia lata inlay and nasoseptal flap onlay is effective for preventing postoperative CSF leakage in resection of planum sphenoidale and/or tuberculum sellae meningiomas, and offers high reproducibility due to its low cost.

Pneumocephalus after Orbital Decompression Surgery for Thyroid Eye Disease

A cerebrospinal fluid (CSF) leak is a rare complication after orbital surgery. We reported a 49-year-old man who presented with CSF leakage after transcaruncular medial wall decompression for proptosis due to thyroid eye disease. He underwent an endoscopic endonasal approach to surgical repair of the defect with nasoseptal flap. Rhinorrhea was stopped immediately after endoscopic repair.

Methods of Skull Base Repair Following Endoscopic Endonasal Tumor Resection: A Review

Following the introduction of fully endoscopic techniques for the resection of pituitary tumors, there was a rapid expansion of the indications for endonasal endoscopic surgery to include extrasellar tumors of the skull base. These techniques offer significant advantages over traditional open surgical approaches to the skull base, including improved tumor resection, and better post-operative neurological outcomes. Following their introduction, however, the initial rate of post-operative CSF leak was unacceptably high. Post-operative CSF leak following skull base surgery is a major source of morbidity, and can lead to the development of life-threatening intracranial infection. The use of vascularized naso-septal flaps transformed the management of these patients, significantly reducing the rate of post-operative CSF leak and increasing the number of patients that could benefit from this less invasive treatment modality. Adequate repair of iatrogenic defects in the skull base is of crucial importance for patients with skull base tumors, as the development of a post-operative CSF leak, and the associated complications can significantly delay the administration of the adjunctive oncological therapies these patients require. In this review, we provide an overview of the latest evidence regarding skull base reconstruction following endoscopic skull base surgery, and describe the skull base repair technique in use at our institution.

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.

Sellar trough technique for endoscopic endonasal transclival repair

Background:

Endoscopic endonasal transclival approaches provide direct access to the ventral skull base allowing the treating of clival and paraclival pathology without the manipulation of the brain or neurovascular structures. Postoperative spinal fluid leak, however, remains a challenge and various techniques have been described to reconstruct the operative defect. The “gasket seal” has been well-described, but has anatomic challenges when applied to clival defects. We describe a modification of this technique for use in endonasal transclival approaches.

Methods:

Two patients who underwent an endoscopic endonasal transclival approach for tumor resection with an intraoperative spinal fluid leak underwent a modified “gasket seal” closure technique for skull base reconstruction.

Results:

A 71-year-old woman with a petroclival meningioma and a 22 year old with a clival chordoma underwent endoscopic endonasal transclival resection with the modified repair. No new postoperative deficits occurred and no postoperative spinal fluid leak was seen with a follow-up of 17 and 23 months, respectively.

Conclusion:

We describe the successful use of a simple, low risk, and technique modification of the “gasket seal” technique adapted to the clivus that allows for hard reconstruction and facilitates placement of the nasoseptal flap.

Efficacy and Safety of Intraoperative Lumbar Drain in Endoscopic Skull Base Tumor Resection: A Meta-Analysis

Objectives: This study aims to evaluate the efficacy and safety of lumbar drainage (LD) in preventing cerebrospinal fluid (CSF) leaks after endoscopic skull base tumor resection. Methods: A systematic online search was conducted using PubMed, Embase, Scopus, Web of Science, and Cochrane Library from January 2006 to July 2019. Data analyses were performed by the Cochrane Collaboration's Review Manager 5.3 software. Results: Eight studies, including two randomized controlled trials and six observational studies, met the inclusion criteria. No significant difference was found in the post-operative CSF leak rate between the LD group and the non-LD group [odds ratio (OR), 0.80; 95%CI, 0.37-1.74; I 2 = 37%; P = 0.57). Subgroup analysis of the intraoperative high-flow leaks, including 4 studies and 313 patients, showed that LD was associated with reduced likelihood of post-operative CSF leak (OR, 0.37; 95%CI, 0.17-0.83; I 2 = 0%; P = 0.02). The placement of LD was related to increased risk of headache compared with non-LD use, and no significant difference was found in the occurrence of deep vein thromboses and pulmonary emboli between two groups. Conclusion: LD is not recommended in all patients undergoing endoscopic skull base tumor resection. However, for patients with intraoperative high-flow leaks, LD is effective and safe in reducing risk of CSF leak.

Surgical management of craniopharyngiomas in adult patients: a systematic review and consensus statement on behalf of the EANS skull base section

BACKGROUND AND OBJECTIVE

Craniopharyngiomas are locally aggressive neuroepithelial tumors infiltrating nearby critical neurovascular structures. The majority of published surgical series deal with childhood-onset craniopharyngiomas, while the optimal surgical management for adult-onset tumors remains unclear. The aim of this paper is to summarize the main principles defining the surgical strategy for the management of craniopharyngiomas in adult patients through an extensive systematic literature review in order to formulate a series of recommendations.

MATERIAL AND METHODS

The MEDLINE database was systematically reviewed (January 1970-February 2019) to identify pertinent articles dealing with the surgical management of adult-onset craniopharyngiomas. A summary of literature evidence was proposed after discussion within the EANS skull base section.

RESULTS

The EANS task force formulated 13 recommendations and 4 suggestions. Treatment of these patients should be performed in tertiary referral centers. The endonasal approach is presently recommended for midline craniopharyngiomas because of the improved GTR and superior endocrinological and visual outcomes. The rate of CSF leak has strongly diminished with the use of the multilayer reconstruction technique. Transcranial approaches are recommended for tumors presenting lateral extensions or purely intraventricular. Independent of the technique, a maximal but hypothalamic-sparing resection should be performed to limit the occurrence of postoperative hypothalamic syndromes and metabolic complications. Similar principles should also be applied for tumor recurrences. Radiotherapy or intracystic agents are alternative treatments when no further surgery is possible. A multidisciplinary long-term follow-up is necessary.

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.

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.

Evaluation of Intranasal Flap Perfusion by Intraoperative Indocyanine Green Fluorescence Angiography

BACKGROUND

Vascularized intranasal flaps are the primary reconstructive option for endoscopic skull base defects. Flap vascularity may be compromised by injury to the pedicle or prior endonasal surgery. There is currently no validated technique for intraoperative evaluation of intranasal flap viability.

OBJECTIVE

To evaluate the efficacy of indocyanine green (ICG) near-infrared angiography in predicting the viability of pedicled intranasal flaps during endoscopic skull base surgery through a pilot study.

METHODS

ICG near-infrared fluorescence endoscopy was performed during endoscopic endonasal surgery for skull base tumors. Intraoperative and postoperative data were collected regarding enhancement of the flap body and pedicle. Fluorescence was rated qualitatively. Postoperatively, flap perfusion was evaluated via MRI-contrast enhancement in addition to clinical outcomes (cerebrospinal fluid leak and endoscopic flap appearance).

RESULTS

Thirty-eight patients underwent ICG fluorescence angiography. Both the body and pedicle enhanced in 20 patients (53%), while the pedicle only enhanced for 12 patients (32%), the body only for 3 (8%), and neither for 3 (8%). When both the pedicle and body enhanced with ICG, the rate of postoperative MRI contrast enhancement was 100% and the rate of flap necrosis was 0%. The sensitivity and specificity of flap pedicle ICG enhancement for predicting postoperative flap MRI enhancement were 97% and 67%, respectively. Two of 3 patients without enhancement developed flap necrosis.

CONCLUSION

ICG fluorescence angiography of intraoperative flap perfusion is feasible and correlates well with outcomes of postoperative MRI flap enhancement and flap necrosis. Additional study is needed to further refine the imaging technique and optimally characterize the clinical utility.

Does lumbar drainage reduce postoperative cerebrospinal fluid leak after endoscopic endonasal skull base surgery? A prospective, randomized controlled trial

OBJECTIVE

Based on a null hypothesis that the use of short-term lumbar drainage (LD) after endoscopic endonasal surgery (EES) for intradural pathology does not prevent postoperative CSF leaks, a trial was conducted to assess the effect of postoperative LD on postoperative CSF leak following standard reconstruction.

METHODS

A prospective, randomized controlled trial of lumbar drain placement after endoscopic endonasal skull base surgery was performed from February 2011 to March 2015. All patients had 3-month follow-up data. Surgeons were blinded to which patients would or would not receive the drain until after closure was completed. An a priori power analysis calculation assuming 80% of power, 5% postoperative CSF leak rate in the no-LD group, and 16% in the LD group determined a planned sample size of 186 patients. A routine data and safety check was performed with every 50 patients being recruited to ensure the efficacy of randomization and safety. These interim tests were run by a statistician who was not blinded to the arms they were evaluating. This study accrued 230 consecutive adult patients with skull base pathology who were eligible for endoscopic endonasal resection. Inclusion criteria (high-flow leak) were dural defect greater than 1 cm2 (mandatory), extensive arachnoid dissection, and/or dissection into a ventricle or cistern. Sixty patients were excluded because they did not meet the inclusion criteria. One hundred seventy patients were randomized to either receive or not receive a lumbar drain.

RESULTS

One hundred seventy patients were randomized, with a mean age of 51.6 years (range 19-86 years) and 38% were male. The mean BMI for the entire cohort was 28.1 kg/m2. The experimental cohort with postoperative LD had an 8.2% rate of CSF leak compared to a 21.2% rate in the control group (odds ratio 3.0, 95% confidence interval 1.2-7.6, p = 0.017). In 106 patients in whom defect size was measured intraoperatively, a larger defect was associated with postoperative CSF leak (6.2 vs 2.9 cm2, p = 0.03). No significant difference was identified in BMI between those with (mean 28.4 ± 4.3 kg/m2) and without (mean 28.1 ± 5.6 kg/m2) postoperative CSF leak (p = 0.79). Furthermore, when patients were grouped based on BMI < 25, 25-29.9, and > 30 kg/m2, no difference was noted in the rates of CSF fistula (p = 0.97).

CONCLUSIONS

Among patients undergoing intradural EES judged to be at high risk for CSF leak as defined by the study's inclusion criteria, perioperative LD used in the context of vascularized nasoseptal flap closure significantly reduced the rate of postoperative CSF leaks.Clinical trial registration no.: NCT03163134 (clinicaltrials.gov).

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.

Smoking and Obesity are Risk Factors for Thirty-Day Readmissions Following Skull Base Surgery

Background  Thirty-day readmission has become a significant health care metric reflecting the quality of care and on the cost of service delivery. There is little data on the impact of complications following skull base surgery (SBS) on emergency readmission. Identifying modifiable risk factors for readmission may improve care and reduce cost. Design  The study was designed as a single-center retrospective cohort study. Methods  Records for a consecutive series of 165 patients who underwent open or endoscopic SBS by a single surgeon reviewed. Patients with pituitary adenoma were excluded. The diagnosis, procedure, complications, length of stay (LOS), body mass index (BMI), and smoking status were recorded. Readmission to the neurosurgical department or regional hospitals was either noted prospectively or the patient contacted. Cause and length of readmission was documented. Results  Of the 165 cases, 14 (8.5%) were readmitted within 30 days. Causes for readmission included cerebrospinal fluid (CSF) leak in 5/14 or 35.7% (overall rate for readmission for this complication in the series is 3.1%), infection in 4/14 (28.6%), hyponatraemia in 2/14 (14.3%), vascular: sinus thrombosis in 1/14 (7.1%), seizures in 1/14 (7.1%), and epistaxis in 1/14 (7.1%). Initial and readmission LOS was 6 and 14 days, respectively. BMI was higher in those readmitted within 30 days (33.2 kg/m ² ) versus no readmission (27.1 kg/m ² ). In addition, of those readmitted within 30 days, 35.7% were smokers compared with 20.8% in those not readmitted. Conclusion  In this series, smoking and raised BMI may be indicators for within 30-day readmission and complications in this population, raising the question of risk factor modification prior to elective intervention.

Impact of Multilayer Vascularized Reconstruction after Skull Base Endoscopic Endonasal Approaches

Background  The use of vascularized flap to reconstruct the skull base defects has dramatically changed the postoperative cerebrospinal fluid (CSF) leak rates allowing the expansion of endoscopic skull base procedures. At present, there is insufficient scientific evidence to permit identification of the optimal reconstruction technique after the endoscopic endonasal approach (EEA). Objective  The main purpose of this article is to establish the risk factors for failure in the reconstruction after EEA and whether the use of a surgical reconstruction protocol can improve the surgical results. Material and Methods  A retrospective cohort study was conducted in our institution, selecting patients that underwent EEA with intraoperative CSF leak. Two reconstructive protocols were defined based on different reconstructive techniques; both were vascularized but one monolayer and the other multilayer. A multivariate analysis was performed with outcome variable presentation of postoperative leak. Results  One hundred one patients were included in the study. Patients reconstructed with protocol 1, with the diagnosis different to the pituitary adenoma and older than 45 years old had higher risk of presenting postoperative leak, and with statistically significant differences when we adjusted for the remaining variables. Conclusion  The vascularized reconstructions after endoscopic endonasal skull base approaches have demonstrated to be able to obtain a low rate of postoperative CSF leak. The multilayer vascularized technique may provide a more evolved technique, even reducing the postoperative leak rates comparing with the monolayer vascularized one. The reconstructive protocol employed in each case, as well as age and histological diagnosis, is independent risk factor for presenting postoperative leak.

Medically induced CSF rhinorrhea following treatment of macroprolactinoma: case series and literature review

PURPOSE

Although several reports have addressed cerebrospinal fluid (CSF) rhinorrhea following dopamine agonist (DA) therapy of macroprolactinomas, further study is warranted for this relatively uncommon entity. Toward this aim, our retrospective series and review of literature further clarifies recommendations in treatment of this rare problem.

METHODS

We retrospectively reviewed all macroprolactinoma cases in our hospital for a 15-year period. Our systematic search of PubMed identified original articles and reviews of all macroprolactinoma cases with an associated medication-induced CSF leak.

RESULTS

Five patients with drug-induced CSF leak were identified; four of these patients received cabergoline therapy an average of 6 weeks before the onset of rhinorrhea and then underwent surgical repair of the CSF leak. Of 35 published studies included, we identified 60 patients with medication-induced CSF leak. Medical therapy included bromocriptine in 34 patients, cabergoline in 21 patients, and use of both DAs in two patients. Three cases did include complete diagnostic and treatment data. Median time from initiation of the DA treatment to occurrence of rhinorrhea was 6 weeks. For CSF rhinorrhea, 49 patients underwent surgical repair (38 by the transnasal approach) and seven patients were treated nonoperatively.

CONCLUSION

Baseline skull base erosion in macroprolactinomas in combination with subsequent tumor shrinkage induced by DA therapy may result in spontaneous CSF rhinorrhea. Therefore, such patients should be advised about and monitored for this potential setback. Once CSF leak is diagnosed, prompt treatment must be carried out to avoid infectious complications. Transnasal surgery appears the most effective therapeutic approach.

The Effect of lumbar drains on spontaneous cerebrospinal fluid leak repair

Objectives:

To address the factors affecting recurrence after endoscopic surgical repairs of spontaneous cerebrospinal fluid leak, specifically the influence of using lumbar drains.

Methods:

This study involved a retrospective data analysis, including a chart review of all spontaneous cerebrospinal fluid (CSF) leak cases who underwent endoscopic anterior skull base repair from 2012-2017 in King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia.

Results:

Thirteen patients with spontaneous CSF leaks were identified and evaluated. The majority were females (92.3%) with an average body mass index of 34.9. All patients underwent endoscopic repair with intra-operative lumbar drain placement. Patients continued having post-operative lumbar drain for an average of 6.4 days. Four patients (30.8%) developed recurrence; however, only one of those had a documented high opening pressure.

Conclusion:

Spontaneous CSF leak repairs are at a higher failure risk and may have an underlying pathology involving CSF circulation. The use of lumbar drains and intracranial pressure lowering agents are controversial and seems to be reserved only for high risk patients; however, the higher risk of recurrence in this group may be better managed by proper pre-operative evaluation and selective, patient-specific management protocols.

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.

Endoscopic Endonasal Reconstructive Methods to the Anterior Skull Base

The success of expanded endoscopic endonasal approaches (EEAs) to the anterior skull base, sellar, and parasellar regions has been greatly aided by the advancement in reconstructive techniques. In particular, the pedicled vascularized flaps have been developed and effectively cover skull base defects of varying sizes with a significant reduction in postoperative CSF leaks. There are two aims to this review: (1) We will provide our current, simplified reconstruction algorithm. (2) We will describe, in detail, the relevant anatomy, indications/contraindications, and surgical technique, with a particular emphasis on the nasoseptal flap (NSF). The inferior turbinate flap (ITF), middle turbinate flap (MTF), pericranial flap (PCF), and temporoparietal fascial flap (TPFF) will also be described. The NSF should be the primary option for reconstruction of majority of skull base defects following endonasal endoscopic surgery. In general, for the planum, cribriform, and upper two-thirds of the clivus, the NSF is ideal. For the lower-third of the clivus, the NSF may not be adequate and may require additional reconstructive options. Although limited in reach or more technically challenging, these reconstructive flaps should still be considered and kept in the surgical algorithm.

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.

Combined Endoscopic and Open Approaches in the Management of Sinonasal and Ventral Skull Base Malignancies

Combined transcranial and endoscopic endonasal approaches remain useful in the treatment of ventral skull base malignancies. The extended bifrontal transbasal approach provides wide access to the anterior ventral skull base and paranasal sinuses without transfacial incisions. In more extensive lesions, the bifrontal transbasal approach can then be combined with an endoscopic endonasal approach (EEA) from below. This article reviews the indications, surgical technique, and operative nuances of combined transbasal and EEA (cranionasal) approaches for the surgical management of ventral skull base malignancies.

Risk factors associated with postoperative cerebrospinal fluid leak after endoscopic endonasal skull base surgery

OBJECTIVE The aim in this paper was to determine risk factors for the development of a postoperative CSF leak after an endoscopic endonasal approach (EEA) for resection of skull base tumors. METHODS A retrospective review of patients who underwent EEA for the resection of intradural pathology between January 1997 and June 2012 was performed. Basic demographic data were collected, along with patient body mass index (BMI), tumor pathology, reconstruction technique, lumbar drainage, and outcomes. RESULTS Of the 615 patients studied, 103 developed a postoperative CSF leak (16.7%). Sex and perioperative lumbar drainage did not affect CSF leakage rates. Posterior fossa tumors had the highest rate of CSF leakage (32.6%), followed by anterior skull base lesions (21.0%) and sellar/suprasellar lesions (9.9%) (p < 0.0001). There was a higher leakage rate for overweight and obese patients (BMI > 25 kg/m²) than for those with a healthy-weight BMI (18.7% vs 11.5%; p = 0.04). Patients in whom a pedicled vascularized flap was used for reconstruction had a lower leakage rate than those in whom a free graft was used (13.5% vs 27.8%; p = 0.0015). In patients with a BMI > 25 kg/m², the use of a pedicled flap reduced the rate of CSF leakage from 29.5% to 15.0% (p = 0.001); in patients of normal weight, this reduction did not reach statistical significance (21.9% [pedicled flap] vs 9.2% [free graft]; p = 0.09). CONCLUSIONS Preoperative BMI > 25 kg/m² and tumor location in the posterior fossa were associated with higher rates of postoperative CSF leak. Use of a pedicled vascularized flap may be associated with reduced risk of a CSF leak, particularly in overweight patients.

Role of lumbar drains in contemporary endonasal skull base surgery: Meta-analysis and systematic review

BACKGROUND

Historically, lumbar drains (LD) have played a prominent role in endonasal skull base surgery. Over the past few decades, advancements in techniques have augmented our ability to successfully reconstruct complex skull base defects and often obviates the need for cerebrospinal fluid (CSF) diversion. Clarity on the appropriate use of LDs is needed.

OBJECTIVE

To examine the literature for the need for LDs in contemporary skull base reconstruction after resection of skull base tumors.

METHODS

A systematic literature review of English language articles by using PubMed and Ovid. Search terms included "lumbar drain," "CSF leak," and "endoscopic endonasal reconstruction." Articles were included when they pertained to adults, used current methods for reconstruction (i.e., multilayered repair or vascularized tissue), and addressed CSF leak rates secondary to endoscopic resection of skull base masses. All the studies discussed CSF leaks that resulted from traumatic-, idiopathic-, or sinus surgery-related iatrogenic causes were excluded. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed.

RESULTS

A total of five articles met inclusion criteria. These comprised 376 endoscopic skull base tumor resection and reconstruction cases; 5.59% developed postoperative CSF leaks. A meta-analysis was conducted by incorporating three studies that met criteria based on testing for heterogeneity. The average odds ratio for postoperative CSF leak for patients who did not have an LD relative to patients who had an LD was 0.590 (95% confidence interval, 0.214-1.630). Given a p value of 0.30, the results demonstrated a lack of statistically significant improvement between patients who had an LD and patients who did not have an LD. Various details, such as the defect size and type of CSF leak, were not consistently reported among studies.

CONCLUSIONS

Available evidence for the use of LDs in skull base surgery is of poor quality. Analysis of the literature revealed heterogenous and varied reporting in the primary literature. Further studies that include randomized controlled trials are needed.

Lumbar Drains Decrease the Risk of Postoperative Cerebrospinal Fluid Leak Following Endonasal Endoscopic Surgery for Suprasellar Meningiomas in Patients With High Body Mass Index

BACKGROUND

Postoperative cerebrospinal fluid (CSF) leak is a persistent, albeit much less prominent, complication following endonasal endoscopic surgery. The pathology with highest risk is suprasellar meningiomas. A postoperative lumbar drain (LD) is used to decrease the risk of CSF leak but is not universally accepted.

OBJECTIVE

To compare the rates of postoperative CSF leak between patients with and without LD who underwent endonasal endoscopic surgical resection of suprasellar meningiomas.

METHODS

A consecutive series of newly diagnosed suprasellar meningiomas was drawn from a prospectively acquired database of endonasal endoscopic surgeries at our institution. An intraoperative, preresection LD was placed and left open at 5 cc/h for ∼48 h. In a subset of patients, the LD could not be placed. Rates of postoperative CSF leak were compared between patients with and without an LD.

RESULTS

Twenty-five patients underwent endonasal endoscopic surgical resection of suprasellar meningiomas. An LD could not be placed in 2 patients. There were 2 postoperative CSF leaks (8%), both of which occurred in the patients who did not have an LD (P = .0033). The average body mass index (BMI) of the patients in whom the LD could not be placed was 39.1 kg/m2, compared with 27.6 kg/m2 for those in whom the LD could be placed (P = .009). In the subgroup of obese patients (BMI &gt; 30 kg/m2), LD placement was protective against postoperative CSF leak (P = .022).

CONCLUSION

The inability to place an LD in patients with obesity is a risk factor for postoperative CSF leak. An LD may be useful to prevent postoperative CSF leak, particularly in patients with elevated BMI.

Endoscopic Resection of Sinonasal and Ventral Skull Base Malignancies

The transnasal endoscopic resection of ventral skull base lesions represents a safe and effective method for the surgical management of sinonasal and ventral skull base malignancies in carefully selected cases. The goal of surgery is complete removal of all tumor with negative resection margins while maintaining the key oncological principles. Careful selection of cases along with the presence of an experienced surgeon and a fully involved multidisciplinary skull base team trained in the management of ventral skull base neoplasm are essential for excellent outcomes.

Outcomes of Endoscopic Repair of Cerebrospinal Fluid Rhinorrhea without Lumbar Drains

Objective

Lumbar drains (LD) are commonly used during endoscopic repair of cerebrospinal fluid (CSF) rhinorrhea, either to facilitate graft healing or to monitor CSF fluid dynamics. However, the indications and necessity of LD placement remains controversial. The current study sought to evaluate endoscopic CSF leak repair outcomes in the setting of limited LD use.

Methods

Patients who underwent endoscopic repair of CSF rhinorrhea between 2004 and 2014 were identified by a review of medical records. Demographic and clinical data were extracted and compared between patients who had surgery with and patients who had surgery without a perioperative LD. A univariate analysis was performed to identify factors predictive of recurrence.

Results

A total of 107 patients (116 surgical procedures) were identified, with a mean follow-up of 15.8 months. Eighty-eight of 107 patients (82.2%) had surgery without an LD. The mean hospital stay was 4.48 days in the LD group versus 1.03 days in the non-LD group (p ≤ 0.00001). There was no difference in recurrence rate between the LD and non-LD groups. Predictors of recurrence included repair technique (p = 0.04) and size of defect (p = 0.005). Body mass index, leak site (ethmoid, sphenoid, frontal), and etiology (spontaneous, iatrogenic, traumatic) were not predictive of leak recurrence.

Conclusion

Use of LDs in endoscopic CSF leak repair was not associated with reduced recurrence rates, regardless of leak etiology, and resulted in a significant increase in hospital length of stay. Although the use of perioperative LDs to monitor CSF dynamics may have some therapeutic and diagnostic advantages, it may not be associated with clinically significant improvements in patient outcomes or recurrence rates.

Updates in anterior skull base reconstruction

PURPOSE OF REVIEW

This article summarizes the indications and surgical techniques for the reconstructions of anterior skull base defects.

RECENT FINDINGS

There is increasing popularity of the vascularized pedicled flaps in endoscopic skull base surgery for the successful reconstruction of anterior skull base defects, compared with the use of free-tissue grafts. The location and size of the defect as well as the rate of cerebrospinal fluid (CSF) flow are important considerations for selection of the most appropriate reconstructive approach. Recent literature provides evidence suggesting that pedicled flaps may be more effective for clival defects and high-flow CSF leaks, potentially reducing the incidence of postoperative CSF leaks. Although the nasoseptal flap (NSF) continues to be the mainstay of endoscopic skull base reconstruction, alternative vascularized flaps exist when the NSF is impractical or unavailable, and new surgical approaches continue to evolve.

SUMMARY

Vascularized pedicled flaps, and especially the NSF, have greatly reduced complications associated with endoscopic skull base surgery. Multiple considerations should be taken into account during closure of skull base defects, and several options are available to accommodate different needs.

Efficacy of Perioperative Lumbar Drainage following Endonasal Endoscopic Cerebrospinal Fluid Leak Repair: A Meta-analysis

Objective

Perioperative lumbar drain (LD) use in the setting of endoscopic cerebrospinal fluid (CSF) leak repair is a well-established practice. However, recent data suggest that LDs may not provide significant benefit and may thus confer unnecessary risk. To examine this, we conducted a meta-analysis to investigate the effect of LDs on postoperative CSF leak recurrence following endoscopic repair of CSF rhinorrhea.

Data Sources

A comprehensive search was performed with the following databases: Ovid MEDLINE (1947 to November 2015), EMBASE (1974 to November 2015), Cochrane Review, and PubMed (1990 to November 2015).

Review Method

A meta-analysis was performed according to PRISMA guidelines.

Results

A total of 1314 nonduplicate studies were identified in our search. Twelve articles comprising 508 cases met inclusion criteria. Overall, use of LDs was not associated with significantly lower postoperative CSF leak recurrence rates following endoscopic repair of CSF rhinorrhea (odds ratio: 0.89, 95% confidence interval: 0.40-1.95) as compared with cases performed without LDs. Subgroup analysis of only CSF leaks associated with anterior skull base resections (6 studies, 153 cases) also demonstrated that lumbar drainage did not significantly affect rates of successful repair (odds ratio: 2.67, 95% confidence interval: 0.64-11.10).

Conclusions

There is insufficient evidence to support that adjunctive lumbar drainage significantly reduces postoperative CSF leak recurrence in patients undergoing endoscopic CSF leak repair. Subgroup analysis examining only those patients whose CSF leaks were associated with anterior skull base resections demonstrated similar results. More level 1 and 2 studies are needed to further investigate the efficacy of LDs, particularly in the setting of patients at high risk for CSF leak recurrence.

Preventing and Managing Complications in Frontal Sinus Surgery

This review covers potential complications of frontal sinus surgical management and strategies for prevention of these complications. Accordingly, recent advances in frontal sinus surgical techniques are described, and the management of complications stemming both from these and traditional techniques are detailed.

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.