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

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.

Cerebrospinal Fluid Leak after Transsphenoidal Surgery: A Systematic Review and Meta-analysis

Background Cerebrospinal fluid (CSF) leak is widely recognized as a challenging and commonly occurring postoperative complication of transsphenoidal surgery (TSS).

The primary objective of this study is to benchmark the current prevalence of CSF leak after TSS in the adult population.

Methods The authors followed the PRISMA guidelines. The PubMed, Embase, and Cochrane Library databases were searched for articles reporting CSF leak after TSS in the adult population. Meta-analysis was performed using the Untransformed Proportion metric in OpenMetaAnalyst. For two between-group comparisons a generalized linear mixed model was applied.

Results We identified 2,408 articles through the database search, of which 70, published since 2015, were included in this systematic review. These studies yielded 24,979 patients who underwent a total of 25,034 transsphenoidal surgeries. The overall prevalence of postoperative CSF leak was 3.4% (95% confidence interval or CI 2.8–4.0%). The prevalence of CSF leak found in patients undergoing pituitary adenoma resection was 3.2% (95% CI 2.5–4.2%), whereas patients who underwent TSS for another indication had a CSF leak prevalence rate of 7.1% (95% CI 3.0–15.7%) (odds ratio [OR] 2.3, 95% CI 0.9–5.7). Patients with cavernous sinus invasion (OR 3.0, 95% CI 1.1–8.7) and intraoperative CSF leak (OR 5.9, 95% CI 3.8–9.0) have increased risk of postoperative CSF leak. Previous TSS and microscopic surgery are not significantly associated with postoperative CSF leak.

Conclusion The overall recent prevalence of CSF leak after TSS in adults is 3.4%. Intraoperative CSF leak and cavernous sinus invasion appear to be significant risk factors for postoperative CSF leak.

Bilateral “Rescue Strip” Technique for Endoscopic Endonasal Approaches to the Clivus

BACKGROUND

The vascularized nasoseptal flap (NSF) is a pillar of contemporary endoscopic skull base reconstruction. The pedicle for the NSF is supplied by the posterior septal branch of the sphenopalatine artery, which courses along the arch of the choana and sphenoid rostrum before entering the nasal septum. Resection or mobilization of this region is necessary for surgical access to the clivus.

OBJECTIVE

To describe a technique for preserving bilateral NSF pedicles during endoscopic endonasal resection of the clivus, thereby safeguarding availability of the flaps for future skull base repair needs.

METHODS

Report of operative technique with video demonstration.

RESULTS

This technique for NSF preservation allows for wide access to the clivus while saving the future option for vascularized flap repairs of skull base defects. The patient in whom we demonstrate this technique underwent complete resection of her clivus without cerebrospinal fluid leak and with preservation of both NSF pedicles.

CONCLUSION

The “rescue strip” technique for endonasal endoscopic clival surgery preserves the bilateral NSF pedicles for future use without compromising surgical access to the clivus.

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.

Random nasoseptal flap for revision skull base reconstruction

The nasoseptal flap (NSF) has become the workhorse of endoscopic skull base reconstruction (ESBR). With the increase in endoscopic skull base procedures, there has also been the need for staged and revision procedures where the use of the NSF is no longer an option. These cases have posed new and interesting challenges to skull base surgeons especially with regards to reconstructive options. While free mucosal or turbinate grafts may be too small for certain defects, others such as the pericranial flap require an open procedure with added morbidity. We describe the use of a random nasoseptal flap for the reconstruction of a skull base defect.

Complications of Nasoseptal Flap Reconstruction: A Systematic Review

Objective  The nasoseptal flap (NSF) is considered the primary vascularized flap for reconstruction of dural defects with endoscopic endonasal surgery (EES) of the skull base. However, the complications and morbidities associated with this reconstructive flap are poorly understood. This article presents a systematic review of the complications and morbidities related to the use of the NSF in skull base surgery. Method  A systematic review of the literature based on published guidelines was performed to identify potential complications and morbidities related to the NSF. The MEDLINE and Embase databases were searched from January 1, 1950 to February 5, 2018. Results  Twenty-seven articles were identified. Reported complications were as follows: NSF necrosis (4 studies; [0-1.3%]), mucocele formation (5 studies; [0-3.6%]), septal perforation (6 studies, [0-14.4%]), nasal dorsum collapse (2 studies, [0.7-5.8%]), effects on quality of life (QoL) (8 studies), and olfactory loss (11 studies). Conclusion  Although complications associated with the NSF may be underreported in the literature, the NSF appears to be a safe and reliable reconstructive flap in EES of the skull base.

Selection of endoscopic or transcranial surgery for tuberculum sellae meningiomas according to specific anatomical features: a retrospective multicenter analysis (KOSEN-002)

OBJECTIVE

The endoscopic endonasal approach (EEA) and the transcranial approach (TCA) are good options for the treatment of tuberculum sellae (TS) meningiomas. The objective of this study was to identify the key anatomical features in TS meningiomas and compare the two surgical approaches.

METHODS

The authors retrospectively reviewed clinical data in 178 patients with TS meningiomas treated at 3 institutions between January 2010 and July 2016. Patients with tumors encasing the internal carotid artery or anterior cerebral artery or involving the anterior clinoid process or cavernous sinus were excluded. Tumors were classified as high-lying or low-lying based on their location, and involvement of the optic canal was evaluated. The surgical outcomes of EEA and TCA were analyzed according to the relevant anatomical features.

RESULTS

During the study period, 84 patients underwent EEA and 94 patients underwent TCA. Based on preoperative MR images, 43 (24.2%) meningiomas were classified as high-lying tumors, 126 (70.8%) as low-lying, and 9 (5.0%) as nonspecific. Gross-total resection (GTR) was performed in 145 patients (81.5%); the GTR rate did not differ significantly between the EEA and TCA groups. Of 157 patients with preoperative visual disturbance, 140 had improved or stable vision postoperatively. However, 17 patients (9.6%) experienced some visual deterioration after surgery. The TCA group had a worse visual outcome than the EEA group in patients with preoperative optic canal involvement (77.6% vs 93.2%, p = 0.019), whereas there was no significant difference in visual outcome based on whether tumors were high-lying or low-lying.

CONCLUSIONS

The results of this study support EEA over TCA, at least with respect to visual improvement with acceptable complications, although TCA is still an effective approach for TS meningioma.

Is Low-Lying Optic Chiasm an Obstacle to an Endoscopic Endonasal Approach for Retrochiasmatic Craniopharyngiomas? (Korean Society of Endoscopic Neurosurgery -003)

OBJECTIVE

Despite advances in endoscopic techniques, retrochiasmatic craniopharyngiomas (CPs) are difficult to remove completely, because the low-lying optic chiasm often provides an obstacle to an endoscopic endonasal approach. This study aimed to identify the endoscopic surgical outcomes of the retrochiasmatic CP and resolve the issues related to low-lying optic chiasm.

METHODS

We reviewed 154 consecutive patients with CP who underwent endonasal endoscopic resection from February 2009 to April 2017 at 2 independent institutions. The topographic relationship of the tumor with the third ventricle, stalk, and optic chiasm and clinical outcomes were investigated.

RESULTS

Retrochiasmatic CPs were found in 142 of 154 patients (92.2%). The median follow-up time was 25 months. Gross total resection and near-total resection were achieved in 113 patients (79.6%) and 21 patients (13.8%), respectively. Postoperative cerebrospinal fluid leaks were found in 16 patients (11.3%). Low-lying and high-lying chiasms were found in 44 patients (31.0%) and 98 patients (69.0%), respectively. Low-lying chiasm did not affect clinical outcomes including the extent of resection. Patients with low-lying chiasm showed a marginal trend for postoperative visual deterioration. The ventricular growth pattern representing the origin of the tumor and previous surgery were significantly associated with the position of the optic chiasm (P = 0.007 and 0.001, respectively).

CONCLUSIONS

An endoscopic endonasal approach is an effective surgical approach for retrochiasmatic CP, even in tumors with low-lying chiasm. However, a thorough and careful dissection is necessary to prevent visual deterioration.