Combined Nasoseptal and Inferior Turbinate Flap for Reconstruction of Large Skull Base Defect After Expanded Endonasal Approach: Operative Technique

Reconstruction of the Anterior Skull Base Using the Nasoseptal Flap: A Review

The nasoseptal flap is a workhorse reconstructive option for anterior skull base defects during endonasal surgery. This paper highlights the versatility of the nasoseptal flap. After providing a brief historical perspective, this review will focus on the relevant primary literature published in the last ten years. We will touch upon new applications of the flap, how the flap has been modified to expand its reach and robustness, and some of the current limitations. We will conclude by discussing what the future holds for improving upon the design and use of the nasoseptal flap in anterior skull base reconstruction.

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.

Single Versus Double Hadad-Bassagasteguy Flap in Expanded Endoscopic Skull-Base Surgery

The reconstruction of dural defects, after endoscopic removal of skull-base lesions, remains challenging when a large defect or a high flow intraoperative cerebrospinal fluid (CSF) leak is observed. The aim of this study is to describe our preliminary experience with a double Hadad-Bassagasteguy (H-B) flap technique for skull-base repair, comparing its efficacy with the use of a single H-B flap in our series. A retrospective chart review was conducted on patients who underwent exclusive endoscopic endonasal skull-base surgery at our Referral Skull Base Center from December 2014 to January 2018. Data on patient demographics, pathology, preoperative and postoperative imaging, intraoperative findings, surgical route, defect size, reconstruction techniques and repair materials, were analyzed. Patients were divided into double and single H-B flap groups. In the single and double H-B groups, the postoperative CSF leak rates were 37.5% (6 of 16 patients) and 4.5% (1 of 22 patients), respectively. The difference between the two groups was statistically significant (p = 0.0470). In patients with defects > 4 cm or high-flow intraoperative CSF leakage related to the opening of the third ventricle, the double H-B flap was successfully placed with no occurrence of postoperative CSF leakage. The double H-B flap significantly reduced the postoperative CSF leakage rate after expanded transnasal skull-base surgery. Particularly in challenging cases, where a large skull-base defect or a high-flow intraoperative CSF leak was observed, this reconstructive method proved to be very effective, with no evidence of postoperative CSF fistulas.

Rathke's cleft cyst marsupialization and repair with a free mucosal graft - Video case report and literature review

Rathke's cleft cysts (RCCs) are sellar or suprasellar cystic lesions arising from the remnants of the embryological Rathke's pouch. When symptomatic, RCCs are usually treated surgically via marsupialization. Free mucosal graft (FMG) repair has shown promise in decreasing recurrence versus marsupialization alone. The authors present a case report with operative video of a patient with visual and endocrinological symptoms with a RCC treated with FMG following marsupialization. A search of the PubMed database from July 1997 through April 2022 was conducted using the terms 'Rathke's cleft cyst', 'Rathke's cleft cyst management', 'Rathke's cleft cyst repair', 'mucosal graft', 'mucosal coupling', 'transsphenoidal', and 'endoscopic endonasal'. Clinical and pathological aspects of the case presented were compared with information obtained from literature review. A 25-year-old female presented with a six-year history of amenorrhea, one-year history of anemia, headaches, and progressive visual loss. Imaging revealed an RCC. The patient underwent surgical treatment via an endoscopic endonasal approach. Marsupialization was achieved with placement of an FMG to help prevent restenosis. Post-operative examination revealed that the patient's OD vision returned to normal, although her OS vision was only slightly improved. Our review of the English literature resulted in 35 full-length articles that were published between 1997 and 2022. The literature suggests that FMG prevents scar formation by allowing for adequate epithelialization, thus decreasing the recurrence rate and being well tolerated by patients. Our findings support the utility of the FMG as a superior surgical treatment option for RCC management.

Double pedicled nasoseptal flap for skull base repair after endoscopic expanded endonasal approach

BACKGROUND

Expanded endonasal approach offers a spectacular corridor for skull base tumour resection but requires reliable multilayer reconstruction techniques with a vascularized nasoseptal flap.

METHOD

On the basis on our substantial experience of 136 patients operated on between January 2008 and January 2020, the double pedicled nasoseptal flap technique was developed for skull base repair. The technique is finely detailed. The nasal floor mucosa was preserved. CSF leakage occurred in 4% of patients.

CONCLUSION

Double pedicled nasoseptal flap is a reproducible and efficient technique for skull base reconstruction after expanded endonasal approach and is associated with limited rhinological complications.

The Rostral Mucosa: The Door to Open and Close for Targeted Endoscopic Endonasal Approaches to the Clivus

BACKGROUND

Extended endoscopic endonasal approaches (EEAs) have progressively widened the armamentarium of skull base surgeons. In order to reduce approach-related morbidity of EEAs and closure techniques, the development of alternative strategies that minimize the resection of normal tissue and alleviate the use of naso-septal flap (NSF) is needed. We report on a novel targeted approach to the clivus, with incision and closure of the mucosa of the rostrum, as the initial and final step of the approach.

OBJECTIVE

To present an alternative minimally invasive approach and reconstruction technique for selected clival chordomas.

METHODS

Three cases of clival chordomas illustrating this technique are provided, together with an operative video.

RESULTS

The mucosa of the rostrum is incised and elevated from the underlying bone, as first step of surgery. Following tumor resection with angled scope and instruments, the mucosa of the sphenoid sinus (SS) is removed and the tumor cavity and SS are filled with abdominal fat. The mucosal incision of the rostrum is then sutured. A hangman knot is prepared outside the nasal cavity and tightened after the first stitch and a running suture is performed.

CONCLUSION

We propose, in this preliminary report, a new targeted approach and reconstruction strategy, applying to EEAs the classic concept of skin incision and closure for transcranial approaches. With further development in the instrumentations and visualization tools, this technique may become a valuable minimally invasive endonasal approach for selected lesions.

Advances in vascularized flaps for skull base reconstruction

PURPOSE OF REVIEW

Advances in anterior skull base surgery have resulted in the increasing diversification of reconstructive techniques. New vascularized flaps have been suggested in the last years, some quite similar, whereas new uses and applications have been suggested for some vascularized flaps, which have already established their value over the last decades. In this article, we describe the developments in skull base reconstruction with vascularized flaps and analyse the international experience in the use of vascularized flaps published with a focus on the last 18 months.

RECENT FINDINGS

Over the past 18 months, a number of novel or modified vascularized intranasal flaps have been described, focusing on reconstruction of larger defects, the medial orbital wall, the anterior skull base (septal flip-flap) and dissection of the nasoseptal flap from the SPA foramen. Extranasal vascularized flaps, which have been around for a long time, still have their rightful place in skull base reconstruction and have recently been adjusted for endoscopic use.

SUMMARY

We present an overview of the latest developments in vascularized flaps (intranasal and extranasal), their new implications, their modifications and complications or predictions of viability.

Vascular pedicled flaps for skull base defect reconstruction

OBJECTIVE

Techniques for reconstruction of skull base defects have advanced greatly since the introduction of the vascular pedicled nasoseptal flap in 2006. The objective of this review is to assess the current state of the field by examining both intranasal and extranasal techniques of vascular pedicled skull base defect repair, their indications and success rates, and novel techniques that are currently under investigation.

METHODS

A review of the literature describing the use of vascular pedicled flaps in skull base defect reconstruction was conducted using PubMed and Google Scholar.

RESULTS

The nasoseptal flap remains the most widely used vascular pedicled flap for endoscopic repair of skull base defects. Its ease of harvest, wide arch of rotation, and high success rates make it a popular choice among surgeons. Several variations including a "rescue" nasopseptal flap have been developed. Other less commonly used pedicled intranasal flaps include the middle turbinate flap and the posterior pedicled inferior turbinate flap. Additionally, several novel vascular pedicled flaps have been developed and tested in small cohorts of patients. Extranasal flaps such as the pericranial flap and the temporoparietal fascia flap are used less frequently than intranasal flaps. However, they remain valuable options for reconstruction in certain situations.

CONCLUSION

Advancements continue to be made in the field of skull base defect reconstruction using vascular pedicled flaps. Though the nasoseptal flap remains the most widely utilized option, additional intranasal techniques continue to be developed and tested to optimize surgical outcomes and patient care.

LEVEL OF EVIDENCE

NA.

Anterior skull base reconstruction using nasoseptal flap: cadaveric feasibility study and clinical implication [SevEN-001]

BACKGROUND

Pedicled nasoseptal flap (PNSF) has significantly improved the surgical outcomes of endoscopic endonasal approach (EEAs) by reducing cerebrospinal fluid (CSF) leakage. The purpose of this study is to assess the feasibility of using a PNSF for anterior skull base (ASB) reconstruction and to describe a method to compensate for a short flap based on our results.

METHODS

In this cadaveric study, ASB dissection without sphenoidotomy was performed using 10 formalin-fixed and 5 fresh adult cadaver specimens, and the sufficiency of the PNSF to cover the ASB was assessed. After the sphenoidotomy, the length by which the PNSF fell short in providing coverage at the posterior wall of the frontal sinus (CPFS), and the extent of the anterior coverage from the limbus (CL) of the sphenoid bone was measured.

RESULTS

Without sphenoidotomy, the mean length of the remaining PNSF after the coverage of the posterior wall of the frontal sinus was 0.67 cm. After sphenoidotomy, the PNSF fell short by a mean length of 2.10 cm, in providing CPFS. The CL was 1.86 cm. Based on these findings, defects resulting from an endoscopic resection of ASB tumors were reconstructed using PNSF without total sphenoidotomy in 3 patients. There were no postoperative CSF leaks or complications.

CONCLUSIONS

The use of PNSF for ASB reconstruction may be insufficient to cover the entire ASB defect after removal of large lesions which need total sphenoidotomy. When possible, by leaving some portion of the anterior sphenoid wall for supporting the PNSF, successful ASB reconstruction could be achieved in endoscopic resection of ASB tumors. Additional methods might be needed in some cases of large ASB lesions wherein the anterior sphenoid wall should be removed totally and the ASB defect is too large.

Intraoperative Repair of Cerebrospinal Fluid Rhinorrhea in Skull Base Tumor Resection: A Retrospective Study of Acellular Dermal Matrix Versus Turbinate Flap

BACKGROUND

The acellular dermal matrix (ADM) and turbinate flap (TF) have been widely used in the reconstruction of skull base defects. However, owing to the lack of reported data, the therapeutic effects have been controversial. The purpose of the present study was to compare the effect of the ADM and TF on cerebrospinal fluid (CSF) rhinorrhea after nasal endoscopic resection of a skull base tumor.

METHODS

The data from 46 patients who had undergone nasal endoscopic resection of a skull base tumor and repair of CSF rhinorrhea were retrospectively analyzed. The patients were divided into ADM and TF groups according to the difference in repair materials used. We compared and analyzed the intraoperative information and postoperative outcomes.

RESULTS

The operation time, blood loss, defect area, and need for blood transfusion were not significantly different between the ALT and TF groups. The postoperative length of hospital stay (14.33 ± 3.66 vs. 16.76 ± 5.51 days; P = 0.669) and the incidence of complications, including wound infection (1 vs. 0; P = 0.270), intracranial infection (1 vs. 1; P = 0.900), hemorrhage (2 vs. 3; P = 0.788), 15-day CSF leak (1 vs. 2; P = 0.658), and respiratory infection (2 vs. 1; P = 0.450) were comparable between the 2 groups. The 6-month (0 vs. 0; P = 1.000) and 12-month (0 vs. 0; P = 1.000) incidence of recurrence also showed no significant differences.

CONCLUSION

The use of the ADM for patients with CSF rhinorrhea showed comparable results in terms of postoperative outcomes compared with the use of TF. ADM could serve as a safe and feasible alternative for endoscopic repair of CSF rhinorrhea after nasal endoscopic resection of skull base tumors.

Lateral nasal wall extension of the nasoseptal flap for skull-base and medial orbital wall defects

BACKGROUND

Sinonasal and skull-base tumors that previously required open resection can often be completely resected via an endonasal approach. The nasoseptal flap (NSF) is the workhorse vascularized tissue flap for the endoscopic reconstruction of large skull-base defects from tumor resections. The objective of the current article is to describe a novel modification of the NSF for simultaneous reconstruction of skull-base and medial orbital wall defects.

METHODS

An extension of the standard NSF to include mucosa of the lateral nasal wall was developed for closure of simultaneous skull-base and medial orbital wall defects. Outcomes including successful cerebrospinal fluid (CSF) leak closure, orbital edema, and postoperative cosmesis are reported. Eyelid edema was characterized according to the Surgeon Periorbital Rating of Edema and Ecchymosis (SPREE) scale.

RESULTS

Three patients underwent reconstruction using the modified NSF (average age 75 years). The average defect size of the skull base was 3.6 ± 0.1 cm by 2.3 ± 0.2 cm. The average defect size of the medial orbit was 2.7 ± 0.1 cm by 2.6 ± 0.1 cm. All defects were successfully covered intraoperatively using the lateral nasal wall extension of the NSF. Two patients developed mild eyelid edema, whereas 1 individual had no noticeable swelling (SPREE classification 2, 2, and 1). All patients were successfully sealed at last clinical follow up (average 28 weeks).

CONCLUSION

The modification of the NSF described here provides excellent coverage for reconstruction of large anterior skull-base defects and simultaneous medial orbital wall defects.