Skull base reconstruction with pedicled nasoseptal flap: Technique, indications, and limitations

Repair of high-flow cerebrospinal fluid leak by combined artificial dura plug and free mucosal flap in 15 cases

Background

In the endoscopic endonasal approach skull base surgery repair and reconstruction of the base of the skull is a critical step. Free mucosal flaps are primarily used to repair low-flow cerebrospinal fluid (CSF) leaks, whereas they are not adequate in the face of high-flow CSF leaks. We propose a modified approach-termed the "Fishing method"-which utilizes free mucosal flaps in combination with absorbable sutures and an artificial dura to reverse-plug the defect, to repair high-flow CSF leaks with a clear point of origin.

Objective

To investigate the application of the "Fishing method" to repair high-flow CSF leaks caused by large diaphragma sellae rupture and small dura leak that occur unexpectedly during endoscopic endonasal sellae area surgery.

Methods

A retrospective analysis was conducted including 15 patients with unexpected intraoperative high-flow cerebrospinal fluid leaks. The "Fishing method" was applied to reconstruct and repair the skull base in these patients, and the results were evaluated.

Results

In 10 cases of large diaphragma sellae rupture that occurred during pituitary adenomas resection, all 10 patients were successfully repaired in a single operation using the "Fishing method", with no cerebrospinal fluid nasal leakage (100%); in 5 cases of small dura ruptures that occurred during chordoma resection, 4 patients underwent successful repair in a single operation, with no cerebrospinal fluid nasal leakage occurring in 80% of cases, resulting in an overall success rate of 93.3%.

Conclusion

The "Fishing method" is a reliable technique for skull base reconstruction and serves as an effective solution for high-flow CSF leaks caused by unexpected large diaphragma sellae rupture or a small dura leak occurring intraoperatively.

A Case of Nasoseptal Flap Reconstruction for Refractory Medial Canthal Fistula

Sino-orbital cutaneous fistulas (SOCFs) are a rare and challenging complication from conditions including granulomatosis with polyangiitis. SOCFs are difficult to manage due to poor vascular supply, compromised tissue, and systemic immunocompromise, which lead to a high rate of recurrence. Given the overall rarity of SOCFs, optimal surgical repair remains controversial, with options ranging from conservative management, onlay grafts, and vascularized flaps. This case report describes a novel one-step approach to SOCF closure using a composite chondral mucosal nasoseptal flap in a patient with a large left medial canthal SOCF that had recurred despite 2 prior attempts at closure including a vascularized paramedian forehead flap. Nasoseptal flaps may provide vascularized mucosal tissue to allow for greater success in closure over traditional, external flaps, and skin grafts.

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.

Olfaction after endoscopic surgery for sellar and parasellar disease: an updated systematic review and meta-analysis

Background: Whether endoscopic surgery for sellar/parasellar disease causes significant deficits in olfactory function remains unclear. We aimed to systematically review the olfactory outcomes in such settings based on the evidence up to date. Methods: PubMed, EMBASE, and CENTRAL were searched through February 1, 2021. Included studies were limited to endoscopic surgery for sellar/parasellar disease with follow-up olfactory function measured by standardized olfactory testing methods or subjective assessment. The primary outcome was the change in olfactory function after surgery assessed by standardized olfactory testing methods. The secondary outcome was the change in subjective olfactory function. Random-effects model was used in obtaining combine effects. Study quality was assessed using the Newcastle–Ottawa scale. Sensitivity analysis was carried out using the leave-one-out approach, and publication bias was assessed using Egger’s test. Results: The results show no significant difference in olfaction assessed by standardized olfactory testing methods at 1–3 months post-surgery (880 patients in 16 studies) or at 6–12 months post-surgery (1320 patients in 16 studies) compared to pre-surgery, whereas a significantly lower subjective olfaction at 3 months was observed. In addition, the lack of significant change in olfaction as assessed by standardized olfactory testing methods was observed regardless of whether patients were treated with or without the nasoseptal flap (NSF) harvesting. Heterogeneity and publication bias were observed, whereas sensitivity analysis showed the meta-analysis results are robust. Conclusion: The findings of this updated systematic review and meta-analysis support the conclusion that endoscopic surgery for sellar and parasellar pathology may pose no greater risk of olfactory dysfunction. In addition, the current evidence does not support there is an increased risk of diminished olfaction among patients treated with NSF during surgery.

Modified Nasoseptal Rescue Flap Technique for Pituitary Adenoma Resection via Endoscopic Endonasal Approach

ABSTRACT

Nasoseptal rescue flap (NSRF), which preserves the pedicle of the flap and is harvested as a nasoseptal flap (NSF) when intraoperative leakage of cerebrospinal fluid (CSF) occurs, is an alternative strategy for skull base reconstruction in patients with pituitary adenoma resection via an endoscopic endonasal approach. However, in practice, the original NSRF technique cannot meet the needs during operation. Therefore, the authors aimed to describe a modified NSRF technique for the resection of pituitary adenoma via endoscopic endonasal approach and to examine its utility and outcomes. The authors retrospectively analyzed the medical records of 87 consecutive patients with pituitary adenoma who underwent endoscopic endonasal surgery performed using NSRF technique from September 2019 to August 2020. Data on intraoperative CSF leakage, NSF conversion rate, and reconstruction-related complications were analyzed. The average age of patients was 50.1 years (men, 50.5%). Twenty-five cases of intraoperative CSF leakage were observed: 23 cases of low-flow CSF leakage and two cases of high-flow CSF leakage. NSRF was converted to NSF in 11 cases. Two patients experienced postoperative CSF leakage after reconstruction without NSF and required unplanned reoperation to rebuild the skull base with NSF. In conclusion, this modified NSRF utilized a minimally invasive way to provide sufficient surgical corridor without the need for pedicle retraction, and it can be effectively converted to an NSF for skull base reconstruction in patients with pituitary adenoma.

Preservation of nasal turbinates in endoscopic, anterior skull base surgery-yes, we can!

Objective

To evaluate the frequency, type and indications of nasal turbinate (NT) resection during endoscopic, anterior skull base surgery and to analyze factors that may have an impact on the need of NT removal.

Methods

In this retrospective cohort study, 306 subjects (150 males and 156 females, mean age 55.4 ± 15.3 years) who underwent multidisciplinary, transnasal, endoscopic tumor surgery of the anterior skull base using 4-handed techniques between 2011 and 2019 at the Department of Otorhinolaryngology, Medical University of Graz, were included.

Results

In the majority of interventions (n = 281/306; 91.8%), all NT were preserved. Significant factors influencing the need of NT resections turned out to be type of endoscopic approach (p < 0.001; V = 0.304), sagittal (p = 0.003; d = 0.481) and transversal (p = 0.017; d = 0.533) tumor diameter, tumor type (p < 0.001; V = 0.355) and tumor location (p < 0.001; V = 0.324).

Conclusions

NT can be preserved in the majority of patients undergoing tumor resection in anterior, transnasal, skullbase surgery and routine resection of NT should be avoided. Variables that have an impact on the need of NT resections are types of endoscopic approaches, sagittal and transversal tumor extension and tumor type. These factors should be considered in planning of surgery and preoperative information of patients.

Outcomes of Middle Turbinate Flap in the Reconstruction of Non-tumorous Ventral Skull Base Defects - an Institutional Review

Objective

Middle turbinate (MT) flap, based on the branches of sphenopalatine artery is one of the commonest mucosal flaps used in endoscopic skull base surgery. The objective of this study is to analyze the outcomes of the MT flap in the reconstruction of non-tumorous ventral skull base defects.

Methods

A retrospective review of patients was done from 2010-19. Patients who underwent reconstruction for non-tumorous ventral skull base defects using middle turbinate (MT) flap were included in the study. The parameters assessed include patient demography, primary etiology, site of the defect, size of the defect, graft materials used, outcomes and postoperative complications.

Results

A total of 13 patients who met the study criteria were included. Three (23.07%) of the patients had meningo-encephalocele, while the remaining 10 (76.93%) had CSF fistula. Isolated foveal defect (53.8%) was the most common site involved, followed by isolated cribriform, combined cribriform-foveal and combined foveal-planar defects. Graft materials used were fascia lata, fat and septal cartilage. MT flap was successfully harvested in 11 (84.6%) patients, with successful outcome in 10/11 patients. Hypoplastic MT was present in two patients, who subsequently required Hadad flap for defect closure. No major complications were reported in the postoperative period.

Conclusion

The MT flap is effective in the reconstruction of selective skull base defects. Appropriate surgical technique and expertise are required for successful harvest. Further studies are required to analyze its outcomes in various skull base defects.

Use of the Omental Free Flap for Treatment of Chronic Anterior Skull Base Infections

Chronic complications following anterior cranial fossa tumor extirpation, such as cerebrospinal fluid leak, meningitis, mucocele, pneumocephalus, and abscess, negatively impact patient quality of life. Robust vascularized tissue is generally required to adequately reconstruct and obliterate this complex geometric space. The aim of this study was to describe outcomes and advantages of the omental flap for these defects. Following institutional review board approval, a prospective, reconstructive database was reviewed from 2011 to 2020. Four patients with chronic anterior skull base complications treated with omental flap reconstruction were identified, with chart reviews performed. Median time from the index operation until the complication ultimately required a free omental transfer was 7.3 years. All patients underwent adjuvant radiation with the indications for surgery, including cerebral abscess, recurrent meningitis, osteomyelitis, and pneumocephalus. All free flaps survived without any need for revision. There were no donor site complications. One patient had delayed healing at an adjacent nasal wound that healed secondarily. At a median follow-up of 19.4 months, none of the patients had recurrent infections. The omental free flap has a number of properties, which make it ideally suitable for anterior skull base defects. Its malleable nature combined with the presence of multiple vascular arcades enable flexibility in flap design to contour to the crevices of 3-dimensional skull base defects. Although other free flaps are available to the plastic surgeon, the versatility and reliability of the omentum make it a first-line consideration for anterior skull base reconstruction.

Cervical-transoral robotic nasopharyngectomy: A preclinical study

BACKGROUND

We performed a preclinical study to assess the feasibility of the cervical-transoral robotic pharyngectomy procedure in surgery for nasopharyngeal cancer, where deep margins and vascular safety are key issues.

MATERIALS AND METHODS

Four cadaveric dissections were performed with the da Vinci Xi system. The first step was a robotic parapharyngeal dissection along the internal carotid artery (ICA). The second step was a type 3 transoral robotic nasopharyngectomy.

RESULTS

In each procedure, a comprehensive dissection of the parapharyngeal space was performed along the ICA up to the foramen lacerum. A type 3 nasopharyngectomy was performed transorally with an "en-bloc" removal of the parapharyngeal space, and with complete removal of the eustachian tube up to its bony part.

CONCLUSION

A comprehensive cervical-transoral robotic type 3 nasopharyngectomy with "en-bloc" removal of the parapharyngeal space and the eustachian tube proved to be technically feasible in a preclinical study.