Endoscopic Endonasal Reconstructive Methods to the Anterior Skull Base

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.

Application of a Novel Versatile Mini Posterior Nasoseptal Graft in Endoscopic Transsphenoidal Pituitary Adenoma Surgery

BACKGROUND

Skull base reconstruction is a key technique in patients undergoing endoscopic transnasal skull base surgery. Although a pedicled nasoseptal flap (PNSF) is often used to repair large skull base defects with high-flow cerebrospinal fluid leakage, bone exposure of the donor site of the PNSF can result in long-term crusting.

OBJECTIVE

To design a novel and versatile mini posterior nasoseptal graft for the reconstruction of defects in the sellar floor or PNSF or pedicled nasoseptal rescue flap (PNSRF) donor site in patients undergoing pituitary adenoma surgery.

METHODS

Patients who underwent pituitary adenoma removal through an endoscopic endonasal approach and repair of a sellar defect or PNSF/PNSRF donor site using the mini posterior nasoseptal graft technique from January 2019 to January 2020 were retrospectively evaluated. Pituitary adenomas were removed using a binostril 4-hand technique through a transnasal transsphenoidal transsellar approach or an expanded transsellar approach.

RESULTS

Mini posterior nasoseptal grafts were successfully used in 70 patients who underwent pituitary adenoma removal through an endoscopic transsphenoidal sellar approach. Mini posterior nasoseptal grafts repaired sellar defects in 40 patients and donor site defects of the contralateral PNSF/PNSRF in 30 patients. None of these patients experienced cerebrospinal fluid leakage or major complications.

CONCLUSIONS

A mini posterior nasoseptal graft is a safe and effective technique for repairing sellar defects after endoscopic transnasal pituitary adenoma surgery. This technique can also be used to repair defects in PNSF/PNSRF donor sites.

Radial Forearm Free Flap with Parapharyngeal Pedicle Corridor for Reconstruction of Anterior Skull Base Defects

BACKGROUND

The radial forearm free flap (RFFF) is an indispensable tool for the reconstruction of a range of defects, including those of the skull base. Several options for routing of the RFFF pedicle have been described, and the parapharyngeal corridor (PC) has been proposed as an option and employed for a nasopharyngeal defect. However, there are no reports of its use for the reconstruction of anterior skull base defects. The objective of this study is to describe the technique for free tissue reconstruction of anterior skull base defects using the RFFF and routing of the pedicle via the PC.

METHODS

Relevant neurovascular landmarks and critical surgical steps for reconstruction of anterior skull base defects with an RFFF and routing of the pedicle via the PC are reported using an illustrative clinical case and cadaveric dissections.

RESULTS

We present a case of a 70-year-old man who underwent endoscopic transcribriform resection of cT4N0 sinonasal squamous cell carcinoma and was left with a large anterior skull base defect that persisted despite several repair attempts. An RFFF was utilized to repair the defect. This report is the first description of the clinical use of the PC for free tissue repair of an anterior skull base defect.

CONCLUSIONS

The PC is an option for routing the pedicle during the reconstruction of anterior skull base defects. When the corridor is prepared as described in this case, a direct route exists from the anterior skull base to cervical vessels, simultaneously maximizing the reach of the pedicle and minimizing the risk of kinking.

Purely nasal floor mucosa-free graft for reconstruction after endoscopic endonasal transellar approach: an anatomical and clinical analysis

BACKGROUND/OBJECTIVE

In this radioanatomical study with clinical correlate, we study a variation of the 'extended nasal floor mucosa' (ENFM) free-graft, the purely nasal floor mucosa (PuNFM) free-graft. The objectives of this study are to evaluate the coverage surface area provided by the PuNFM, study the adequacy of the PuNFM in the reconstruction of endoscopic endonasal approach (EEA) transsellar postoperative defects and compare and evaluate this reconstructive technique with current sellar region reconstruction practices.

METHODS

Dissections were performed on five cadaveric specimens. PuNFM were harvested bilaterally and the area provided for reconstruction was calculated. Twenty-five consecutive cases of pituitary adenomas resected through an EEA were analyzed to estimate the sellar defect surface area (SDSA) after a transsellar EEA and calculate the area of PuNFM bilaterally.

RESULTS

The median cadaveric SDSA was 4.77 cm², with a median left and right side PuNFM area of 5.09 and 5.19 cm², respectively. Clinically, the median SDSA was 5.36 cm², and the total radiological PuNFM surface area was 5.46 cm², with modified Knosp grade >2 tumors having larger SDSA than that of Knosp grade <2 tumors. The PuNFM graft proved to be most effective for covering modified Knosp <2 tumor defects.

CONCLUSIONS

The PuNFM represents a variation of the ENFM free-graft sellar defect reconstruction technique that provides sufficient surface area to reconstruct the majority of the sellar defects related to transsellar EAA for pituitary adenomas. This technique may positively impact sinonasal function and quality of life. Future prospective clinical studies are needed to verify these findings.

Predictive model for preoperative risk calculation of cerebrospinal fluid leak after resection of midline craniofacial mass lesions

Background

Complex anterior skull base defects produced by resection of mass lesions vary in size and configuration and may be extensive. We analyzed the largest single-center series of midline craniofacial lesions extending intra- and extracranially. The study aims at the development of a predictive model for preoperative measurement of the risk of the postoperative cerebrospinal fluid (CSF) leak based on patients' characteristics and surgical plans.

Methods

166 male and 149 female patients with mean age 40,5 years (1 year and - 81 years) operated for benign and tumor-like midline craniofacial mass lesions were retrospectively analyzed using logistic regression method (Ridge regression algorithm was selected). The overall CSF leak rate was 9.6%. The ROSE algorithm and 'glmnet' software suite in R were used to overcome the cohort's disbalance and avoid overtraining the model.

Results

The most influential modifiable negative predictor of the postoperative CSF leak was the use of extracranial and combined approaches. Use of transbasal approaches, gross total resection, utilization of one or two vascularized flaps for skull base reconstruction were the foremost modifiable predictors of a good outcome. Criterium of elevated risk was established at 50% with a specificity of the model as high as 0.83.

Conclusions

The performed study has allowed for identifying the most significant predictors of postoperative CSF leak and developing an effective formula to estimate the risk of this complication using data known for each patient. We believe that the suggested web-based online calculator can be helpful for decision making support in off-pattern clinical situations.

New Nasopharyngeal Flap for Posterior Skull-Base Reconstruction: The Upper-Tongue Flap

Introduction  Reconstructions of clival resection are still challenging, and additional reconstructive methods may be necessary to achieve full coverage of the skull-base defect in patients with middle- and lower-clivus disease.

Objective  To describe a new nasopharyngeal flap for the middle and lower clivus.

Methods  Using nasal endoscopy in a cadaver dissection, we demonstrated a new nasopharygeal flap to cover the lower and middle clival resection.

Results  We described a new nasopharyngeal flap capable of covering the lower and middle portion of the clivus.

Discussion  The new nasopharyngeal flap, called the upper-tongue flap, is particularly adequate as an alternative for the reconstruction of middle and lower clivus defects, and it is better used in association with a nasalseptal flap in cases in which the nasalseptal flap alone does not provide enough mucosal coverage.

Conclusion  The new nasopharyngeal flap can be used in the reconstruction of clival resection.

Surgical Management of Sinonasal Cancers: A Comprehensive Review

Surgery plays an important role in the treatment of sinonasal cancer. Many surgical approaches have been described, including open, endoscopic, or combined approaches. The choice is based on several criteria: general criteria related to the oncological results and morbidity of each technique, specific criteria related to the tumor (tumor extensions, tumor pathology), the patient, or the surgeon himself. The aims of this review are (i) to provide a complete overview of the surgical techniques available for the management of sinonasal malignant tumors, with a special focus on recent developments in the field of transnasal endoscopic surgery; (ii) to summarize the criteria that lead to the choice of one technique over another. In particular, the oncological outcomes, the morbidity of the different techniques, and the specificities of each histologic subtype will be discussed based on a comprehensive literature review.

Sinonasal Squamous Cell Carcinoma, a Narrative Reappraisal of the Current Evidence

Simple Summary

Sinonasal squamous cell carcinomas are a group of diverse tumors affecting the nasal cavity and paranasal sinuses. As a direct consequence of their rarity and heterogeneity, diagnosis is challenging, and treatment does not follow universally accepted protocols. Though surgery represents the mainstay of treatment, neoadjuvant and adjuvant therapies have pivotal roles in improving outcomes of patients treated with curative intent. Indications to endoscopic surgery have been expanding over the last three decades, but a considerable number of patients affected by sinonasal squamous cell carcinoma still need open surgical procedures. Management of the neck in patients affected by sinonasal squamous cell carcinoma is controversial. Curative-intended treatment of recurrent and/or metastatic tumors, alongside palliation of uncurable cases, represent poorly explored aspects of this disease.

Abstract

Sinonasal squamous cell carcinoma is a rare tumor affecting the nasal cavity and paranasal sinuses. Several aspects of this disease, ranging from epidemiology to biology, pathology, diagnosis, staging, treatment, and post-treatment surveillance are controversial, and consensus on how to manage this sinonasal cancer is lacking. A narrative literature review was performed to summarize the current evidence and provide the reader with available data supporting the decision-making process in patients affected by sinonasal squamous cell carcinoma, alongside the authors’ personal opinion on the unsolved issues of this tumor. The review has highlighted several advances in molecular definition of epithelial cancers of the sinonasal tract. Surgery represents the pivot of treatment and is performed through an endoscopic transnasal approach whenever feasible. Open surgery is required for a large proportion of cases. Reconstruction of the defect follows principles of skull base and cranio-maxillo-facial reconstruction. Chemotherapy is given as neoadjuvant treatment or concomitantly to radiotherapy. Photon-based radiation therapy has a crucial role in the adjuvant setting. Particle therapy is providing promising results. Management of the neck should be planned based on the presence of clinically appreciable metastases, primary tumor extension, and need for recipient vessels. Biotherapy and immunotherapy are still underexplored therapeutical modalities.

The Transorbital Pericranial Flap

OBJECTIVE

The objective of the present study was to describe and evaluate the feasibility, mobility, and surface area provided by the simple and extended transorbital pericranial flap (TOPF). Furthermore, we compared this novel technique with the current practice of pericranial flap harvesting and insetting techniques. We also studied the adequacy of the TOPF in the reconstruction of postoperative anterior cranial fossa (ACF) defects.

METHODS

The TOPF was performed bilaterally in 5 alcohol-preserved, latex-injected human cadaveric specimens. The TOPF was harvested in 2 stages: the orbitonasal stage and the cranial stage. For the orbitonasal stage, a transorbital superior eyelid approach was used. We have described 2 harvesting techniques for creating 2 distinct TOPF types (simple and extended) according to the main vascular pedicle. The superficial flap areas offered by the simple and extended TOPF and the traditional bicoronal pericranial flap were calculated and compared. The distances from the supratrochlear and supraorbital arteries to specified anatomical landmarks were also measured. Additionally, the ACF defect area of relevant surgical cases performed using endoscopic transcribriform approaches were measured on immediate postoperative computed tomography head scans using radiological imaging software.

RESULTS

The harvest of both the simple and the extended TOPFs was efficient. As expected, the areas offered by simple and extended TOPFs were smaller than that offered by the traditional bicoronal flap. However, the surface area offered by either the simple or extended TOPF provides sufficient coverage for most ACF defects. A high spatial distribution was observed between the vascular pedicles and their respective foramen or notch.

CONCLUSIONS

The TOPF represents a novel harvesting, tunneling, and insetting technique that offers a large, versatile, pedicled flap for coverage of most standard ACF defects after endoscopic surgery.

Nasoseptal Flap for Skull Base Reconstruction in a Three-Year-Old Child With Nasofrontal Meningoencephalocele

Congenital anterior skull base defects with meningoencephaloceles causing nasal obstruction and cerebrospinal fluid (CSF) rhinorrhea are rare clinical entities. Traditionally, skull base defects have been repaired via a bifrontal craniotomy. With the introduction of pediatric endoscopic instrumentation, more of these lesions are accessible via an intranasal endoscopic approach, even in the infant population. However, due to the rarity of pediatric meningoencephaloceles, there is a lack of data demonstrating the successful adaptation of endoscopic skull base techniques to the pediatric population. In this report, we present a case of a pediatric frontonasal meningoencephalocele with an anterior skull base defect in a 3-year-old child that was successfully addressed transnasally following 4 failed transcranial approaches. The case highlights the importance of a thorough preoperative evaluation of the surgical approach as well as interdisciplinary management of these patients at a young age. Congenital anterior skull base defects with meningoencephaloceles and CSF leaks are rare clinical entities. Hence, an interdisciplinary approach is vital including experienced pediatricians, otolaryngologists, and neurosurgeons to evaluate the ideal surgical method on an individual basis. The transnasal endoscopic technique has been shown to be minimally invasive, efficient, and safe to apply even to the infant population which could positively be demonstrated in this case.

Reconstruction after extended endonasal approaches to the anterior cranial base: surgical techniques and current results

The development of extended endoscopic endonasal approaches (EEA) to the anterior skull base has allowed successful resection of selected extradural and intradural skull base tumors through an endonasal corridor, minimizing brain and cranial nerve manipulation. However, as the complexity of the approaches has increased, so has the need for more robust and reliable reconstructive options to minimize morbidity. Reconstructive decision-making after extended EEA for anterior skull base tumors must take into consideration multiple factors including patient characteristics (Body Mass Index, previous surgeries, and radiation), location and the size of the skull base defect. A multilayered reconstruction which includes a combination of free grafts and a vascularized flap is the standard approach to anterior skull base defects after EEA and should be applied in a stepwise manner tailored to each patient. The techniques and materials used to accomplish skull base repair are discussed, the outcomes in the literature are reviewed, and our reconstructive paradigm presented.

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.

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.

Reconstruction of pediatric skull base defects: A retrospective analysis emphasizing the very young

INTRODUCTION

Pathology of the pediatric skull base is rare and ranges from congenital defects to malignancy and traumatic defects. Pediatric patients, particularly those ≤6 years of age, present a unique set of anatomic challenges for the skull base surgeon. The goal of this study was to retrospectively review our experience with reconstruction of pediatric skull base defects with particular emphasis on those ≤6 years of age.

METHODS

A retrospective chart review was conducted of patients ≤20 years of age who underwent endoscopic endonasal and combined endoscopic and open approaches to address cranial base pathology from 2007 to 2018. Patients were divided into two groups; those ≤6 years of age (group A) and those >6 years of age and ≤20 years of age (group B) and reconstructive techniques and outcomes were analyzed.

RESULTS

Intraoperative communication with the subarachnoid space (CSF leak) was created in 50% (3/6) of patients ≤ 6 years of age compared to 32.7% (16/49) in patients > 6 years and ≤20 years of age (P < 0.40) in management of their skull base disease. A vascularized flap was utilized for reconstruction in 66.7% (4/6) of patients ≤ 6 years of age and included a nasoseptal flap in 33.3% (2/6). A vascularized flap was utilized for reconstruction in 38.8% (19/49) of patients > 6 years and ≤20 years of age and most commonly included a nasoseptal flap (22.4%, 11/49). A lumbar drain was utilized in 50% (3/6) of patients ≤ 6 years of age compared to 18.4% (9/49) in patients > 6 and ≤20 years of age (P < 0.08). Post-operative CSF leaks were encountered in 16.7% (1/6) of patients ≤ 6 years of age compared to 10.2% (5/49) in patients > 6 and ≤20 years of age (P < 0.63). Behavioral issues were noted to potentially contribute to failed skull base reconstruction in patients <6 years of age.

CONCLUSIONS

Pediatric patients, particularly those ≤6 years of age, present a unique set of anatomic and behavioral challenges for the skull base surgeon as highlighted in this study.

Free tissue reconstruction of the anterior skull base: A review

Objective

There has been a significant shift from open craniofacial resection of the anterior skull base to endoscopic approaches that accomplish the same outcomes in tumor ablation. However, when open resection is required, free flap reconstruction is often necessary to provide sufficient well-vascularized tissue for optimal wound healing as well as providing adequate tissue bulk for cosmesis. This articleaims to providea focused review of free flaps most commonly used in anterior skull base reconstruction.

Methods

This is a state-of-the-art review based on expert opinion and previously published reviews and journal articles, queried using PubMed and Google Scholar.

Results & conclusion

Anterior skull base reconstruction via free tissue transfer is imperative in limiting complications and promoting healing, particularly with large defects, post-radiation, and in at-risk patients. The type of free flap utilized for a particular anterior skull base reconstruction should be tailored to the patient and nature of the disease. This review offers insight into the numerous reconstructive options for the free flap surgeon.

Vascular Anatomy of the Inferior Turbinate and Its Clinical Implications

BACKGROUND

Published reports on the vascular anatomy of the inferior turbinate (IT) are limited. Historical papers report the IT artery as a tributary off the posterior lateral nasal artery (PLNA), but this has not been our clinical experience.

OBJECTIVE

The purpose of this study was to examine the arterial blood supply to and the branching pattern within the IT. We discuss this is the context of IT surgery and relate it to postoperative bleeding complication rates.

METHODS

Endoscopic dissection was performed on 16 cadaver heads (24 sides) to determine the origin of the IT artery. Intraoperative surgical videos were analyzed in 50 patients to uncover the vascular branching pattern within the IT. A retrospective review of bleeding complications in patients undergoing IT reduction surgery was also conducted.

RESULTS

In 17 of 24 sides (70.8%), the IT artery arose either exclusively (54.2%) or partly (16.6%) off the descending palatine artery (DPA). As a branch off the DPA, the IT artery exited the pterygopalatine fossa through a foramen located 7.7 ± 3.0 mm from posterior edge of the IT, 8.4 ± 3.1 mm above the nasal floor and 1.6 ± 2.1 mm below the insertion of the IT bone onto the lateral nasal wall. The mean number of arteries cascading within the IT was 2.7 ± 0.5. Moreover, 112 patients underwent IT reduction surgery and 2 (1.8%) experienced postoperative epistaxis.

CONCLUSION

The IT artery has major contributions from the DPA. Most commonly 3 arteries branch within the IT. Knowledge of this vascular anatomy may minimize bleeding associated with IT reduction surgery.

Various modifications of a vascularized nasoseptal flap for repair of extensive skull base dural defects

OBJECTIVE

Endonasal surgery of the skull base requires watertight reconstruction of the skull base that can seal the dural defect to prevent postoperative CSF rhinorrhea and consequent intracranial complications. Although the incidence of CSF leakage has decreased significantly since the introduction in 2006 of the vascularized nasoseptal flap (the Hadad-Bassagasteguy flap), reconstruction of extensive skull base dural defects remains challenging. The authors describe a new, modified vascularized nasoseptal flap for reconstruction of extensive skull base dural defects.

METHODS

A retrospective review was conducted on 39 cases from 2010 to 2017 that involved reconstruction of the skull base with an endonasal vascularized flap. Extended nasoseptal flaps were generated by adding the nasal floor and inferior meatus mucosa, inferior turbinate mucosa, or entire lateral nasal wall mucosa. The authors specifically highlight the surgical techniques for flap design and harvesting of these various modifications of the vascularized nasoseptal flap.

RESULTS

Thirty-nine endonasal vascularized flaps were used to reconstruct skull base defects in 37 patients with nonsurgical or postoperative CSF rhinorrhea. Of the 39 procedures, extended nasoseptal flaps were used in 5 cases (13%). These included 2 extended nasoseptal flaps including the inferior turbinate mucosa and 3 extended nasoseptal flaps including the entire lateral nasal wall mucosa. These 5 extended nasoseptal flaps were used in patients who had nonsurgical CSF rhinorrhea due to extensive skull base destruction by invasive pituitary tumors. All flaps healed completely and sealed off the CSF leaks. Olfactory function slightly decreased in the 3 patients with extended nasoseptal flaps including the entire lateral nasal wall mucosa. One patient experienced nasolacrimal duct obstruction, which was treated by dacryocystorhinostomy. The authors encountered no wound complication in this series, while crusting at the donor site required daily nasal toilette and frequent debridement until the completion of mucosalization, which usually takes 8 to 12 weeks after surgery.

CONCLUSIONS

Extended nasoseptal flaps are a reliable and versatile option that can be used to reconstruct extensive skull base dural defects resulting from destruction by large invasive tumors or complex endoscopic endonasal surgery. An extended nasoseptal flap that includes the entire lateral nasal wall mucosa (360° flap) is the largest endonasal vascularized flap reported to date and may be an alternative for the reconstruction of extensive skull base defects while avoiding the need for additional external approaches.

Tuberculum sellae meningiomas

Tuberculum sellae meningiomas are challenging tumors that can cause significant morbidity for patients because of their proximity to critical neurovascular structures. By studying the anatomy of the tuberculum, the manner in which these tumors grow and cause deficits becomes apparent, as also the challenges associated with surgical removal and management. The necessary preoperative workup and grading scales for preoperative evaluation of tuberculum meningiomas are discussed. Traditional open cranial approaches for resection are discussed and contrasted with the endoscopic endonasal approach. Finally, postoperative management, patient outcomes, and adjuvant therapy for management of residual tumor are considered.

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.

Update on anterior skull base reconstruction

PURPOSE OF REVIEW

Anterior skull base reconstruction has rapidly evolved over the past few years as endoscopic approaches to resect tumors in this region have become more established. The present review evaluates the robust amount of new literature on this topic over the past year with particular attention to minimally invasive methods for reconstruction.

RECENT FINDINGS

Although vascularized local flaps remain the mainstay reconstructive choice when available for the anterior skull base, innovative techniques for all types of reconstruction, ranging from free grafts to free flaps continue to emerge.

SUMMARY

Because of the unique challenges and wide variety of options available to repair the anterior skull base with the goal to prevent or treat cerebrospinal fluid leaks, surgical expertise and experience in this field is of utmost importance.

Esthesioneuroblastoma: A Comprehensive Review of Diagnosis, Management, and Current Treatment Options

INTRODUCTION

Many controversies exist in the diagnosis and management of this aggressively malignant condition, mainly because of limited literature and lack of randomized control trials, resulting in nonstandardized treatment methods. We performed a comprehensive review of the literature to identify management approach and treatment options for esthesioneuroblastoma.

METHODS

An extensive review of the published literature was conducted in PubMed, OVID Medline, and EMBASE journals for studies of esthesioneuroblastoma. Terms for search included esthesioneuroblastoma (ENB) and olfactory neuroblastoma (ONB). No date restrictions were used.

RESULTS

The search yielded 3876 related articles. Cross-checking of articles led to exclusion of duplicate articles. The remaining 1170 articles were screened for their full text and English language availability. Of 609 full-text articles available, animal studies, irrelevant articles, and studies with mixed/confusing data were excluded. We finalized 149 articles pertaining to the topic, including 119 original research articles, 3 book chapters, 11 reviews, 9 case reports, and 7 case series.

CONCLUSIONS

Surgical resection followed by radiotherapy is the standard for treatment for higher-grade lesions. The endoscopic endonasal approach is gaining further recognition with more favorable outcomes and better survival than for open surgery. Postoperative radiotherapy is associated with the highest overall survival and shows benefit for patients with higher-stage disease and those who receive chemotherapy. Recurrence rates after treatment vary drastically in the literature and, therefore, prolonged follow-up with repeated imaging is recommended. Lifelong surveillance is recommended because of late recurrences associated with this tumor.