Complex Skull Base Defects Research Articles

Fascia Lata: Another Workhorse for Complex Skull Base Reconstruction.

Multiple methods exist for skull base reconstruction of defects created by expanded endonasal approaches. While the nasoseptal flap (NSF) has been well established as the workhorse of mucosal reconstruction in complex skull base defects in multi-layered closures, a variety of options exist for the inner layer of multilayer reconstruction, including fascia lata (FL). To present our experience and outcomes in utilizing FL in multiple ways to reconstruct a wide variety of complex skull base defects. Retrospective review was performed from May 2017 to February 2022 to identify 50 consecutive patients who underwent endoscopic skull base reconstruction using FL. FL was employed for reconstruction in 50 patients included in the study: 37 undergoing primary expanded endonasal skull base surgery and 13 revision cases. A wide range of complex pathology was treated, with meningioma and craniopharyngioma being the two most common. FL was utilized as a "button" graft (34/50, 68.0%), free graft inlay/onlay (13/50, 26.0%), and as a button graft combined with onlay (3/50, 6.0%). Expanded surgery defects addressed included tuberculum sella/sphenoid planum (36/50, 72.0%), clivus (6/50, 12.0%), and cribriform/planum (8/50, 16.0%). Successful reconstruction with fascia lata was accomplished in 46/50 cases (92%), with only 4 cases (8%) requiring revision for post-op CSF leak. Donor-site complications were rare with only 1 case (2.0%) of post-op seroma. FL, usually with NSF, offers a versatile option for the reconstruction of challenging defects with excellent outcomes and minimal morbidity. FL is emerging as a workhorse for reconstruction of the inner layer of complex skull base defects.

Pedicle Corridors and Vessel Options for Free Flap Reconstruction following Endoscopic Endonasal Skull Base Surgery: A Systematic Review

Introduction Microvascular free flaps offer an alternative to local and regional flaps for coverage of complex or large skull base defects. Routes and approaches to these reconstructive options are complicated and require an understanding of complex head and neck anatomy. Methods A systematic review of the literature was performed using a set of search terms with the help of a qualified librarian. Articles were reviewed and selected for inclusion based on relevance. We were interested in reporting possible routes for free flap accessibility to the skull base as well as microvascular vessel options, as this choice may affect the geometry and accessibility to the defect. Results A total of 1,917 articles were obtained from a comprehensive search and 11 articles were ultimately found to be relevant to this review. Published options for vessel anastomosis and corridors to the skull base following endoscopic endonasal surgery are reviewed, including Caldwell-Luc/transbuccal space, prevertebral space, transpterygoid/parapharyngeal, and transmaxillary approaches. Conclusion The field of endoscopic surgery has continued to advance and provide options for tumors of the skull base. This has led to a need for creative routes to the skull base for free flap reconstruction.

Endoscopic reconstruction of large anterior skull base defects with opening of the sellar diaphragm. Experience at a tertiary level university hospital.

The indications for expanded endoscopic transnasal approaches continue to increase, with more complex skull base defects needing to be repaired. This study reviews the management of large anterior skull base defects with opening of the sellar diaphragm. A prospective analysis of endonasal endoscopic surgery carried out at Son Espases University Hospital between January 2013 and December 2018 was performed. The analysis included only the cases with a significative intra-operative cerebrospinal fluid leak. In all cases, reconstruction was performed by combining the gasket seal technique with a pedicled mucosal endonasal flap. Twenty-eight patients were included. The mucoperiosteal nasoseptal flap, the lateral wall flap and the middle turbinate flap were used in 13, 8 and 7 patients, respectively, combined with the gasket seal technique. One case of post-operative cerebrospinal fluid leak was observed (3.57 per cent). The combination of a gasket seal with an endonasal mucosal flap is an excellent technique for repairing large anterior skull base defects.

The Challenge of Skull Base Closure: Methods for Reducing Postoperative Cerebrospinal Fluid Leak

With recent advances in endoscopic skull base surgery, larger and more complex skull base defects are encountered and many possible reconstructive methods and materials are available. The purpose of this review is to summarize the possible causes of skull base defects, to describe the challenges associated with skull base reconstruction, and to detail the techniques and materials that may be used. Literature review. Although skull base defects may be caused by traumatic or nontraumatic causes, this review focuses on the endoscopic reconstruction of defects. Many materials are available for endoscopic reconstruction and several techniques have been described for repair of skull base defects. With these advances, the outcomes of endoscopic skull base reconstruction have improved greatly over the past 20 years. Given the complexity of skull base defects and the multiple materials and techniques available for endoscopic reconstruction, a thorough understanding of the challenges associated with skull base repair is crucial for the endoscopic skull base surgeon.

Special considerations for nasoseptal flap use in children

The introduction of the vascularized pedicled nasoseptal flap has revolutionized endoscopic skull base surgery, providing a highly versatile option to repair even the most complex skull base defects. Though demonstrated with outstanding results in adult patients, there is limited experience in the pediatric population. Early investigation found that there are limitations in utilization of the nasoseptal flap in children due to craniofacial restrictions. More recently, these concerns have been mitigated, and nasoseptal flaps are reliably used in reconstructing even the largest skull base defects in the youngest patients. Preoperative planning and review of imaging and meticulous intraoperative dissection are essential for successful reconstructive outcomes.

Management of complex skull base defects accompanied by pneumocephalus

The study aim was to analyze our own experience in treating patients with complex skull base defects accompanied by pneumocephalus and, based on the findings, to develop an optimal treatment approach for this pathology. We retrospectively reviewed a series of 30 patients with complex skull base defects accompanied by pneumocephalus who underwent inpatient treatment at the Burdenko Neurosurgical Institute in the period from 2001 to 2017. We analyzed demographic characteristics of patients (gender, age), clinical data (etiology, somatic and neuropsychiatric status, radiological data), and treatment aspects (conservative or surgical treatment, used approach, defect characteristics, reconstructive materials). Treatment outcomes were assessed based on analysis of changes in clinical manifestations, postoperative complications, and recurrences. The obtained data were compared to the results of literature review. In the series of 30 patients with complex skull base defects accompanied by pneumocephalus, the mean age was 41 years (range, 17-68 years); there were 17 (59%) males and 13 (41%) females. Etiologically, there were 17 (59%) traumatic cases, 11 (36%) iatrogenic cases, and 2 (5%) spontaneous cases. Clinically, the patients presented with the following manifestations: psycho-neurological symptoms (41%), nasal cerebrospinal fluid (CSF) leak (36%), impaired consciousness (27%), and meningitis (23%). Eight patients with acute injuries underwent complex conservative treatment that included infusion, and anti-edema, vascular, metabolic, anticonvulsant, and antibacterial therapy. In cases of conservative treatment failure or tension pneumocephalus accompanied by abrupt worsening of the patient's condition, surgical treatment was used. A total of 24 interventions (including revision surgery) were performed in 22 patients. All patients underwent endoscopic endonasal reconstruction of complex skull base defects. Tissues used for reconstruction included the fascia lata and adipose tissue (77%), fascia lata and cartilage/bone from the nasal septum (14%), and a pedicled nasoseptal flap (9%). The success rate of reconstructive interventions was 91%. There were 2 (9%) recurrences. Postoperative complications in the form of meningitis occurred in 4 (18%) patients. In the case of a nasal cerebrospinal leak history and worsening of the patient's condition accompanied by common cerebral and psychiatric symptoms, the development of pneumocephalus should be considered first, the early diagnosis of which will facilitate choosing the correct treatment approach. In the case of acute injury in patients with the established diagnosis of pneumocephalus caused by gas-forming infection, conservative therapy is indicated in the early period after neurosurgical interventions with opening of the meninges. Tension pneumocephalus together with a skull base bone defect (according to CT) and a nasal CSF leak history is the indication for surgical treatment. In this case, the endoscopic endonasal technique is the method of choice.

Случай двусторонних дефектов латеральных карманов клиновидной пазухи

Spontaneous defects of the lateral recess of the sphenoid sinus result from the incomplete junction of the greater wing of sphenoid bone with the basisphenoid. This anomaly is known as the lateral craniopharyngeal canal or Sternberg’s canal. However, the exact mechanisms of formation of the lateral recess defects are still under-explored and cause much controversy. The progressive erosion of the skull base in patients with high intracranial pressure and highly pneumatized sphenoid sinus may result in generation of defects through which the intracranial content penetrates. In this article, we present a rare case of the development of bilateral meningocele of the lateral recess of the sphenoid sinus with recurrent bilateral liquorrhea. A female patient P, 38 years old, visited our clinic with the complaints of clear nasal discharge from different halves of the nose when the head was bent forward. A computer cisternography showed that the patient had bilateral meningocele of the lateral recesses of the sphenoid sinus. The patient underwent the surgery of endoscopic endonasal plasty of complex skull base defects in the lateral recesses of the sphenoid sinus on the left and right under the control of the Medtronic fusion navigation system. There were no complaints in the postsurgical period, the patient was discharged on the 6th day after surgery.

Submental artery island flap versus free flap reconstruction of lateral facial soft tissue and parotidectomy defects: Comparison of outcomes and patient factors

ObjectivesThe submental artery island flap (SIF) has recently been described in temporal bone defects. At our institution we have broadened the application of the SIF and modified the harvest technique for complex lateral facial and skull base defects. Our primary aim is to evaluate the outcomes of patients undergoing complex lateral facial soft tissue, parotidectomy, and temporal bone defects who are reconstructed with the SIF to a similar cohort undergoing free tissue transfer reconstruction. Materials and methodsNineteen patients undergoing SIF and 54 patients undergoing free tissue flaps for oncologic lateral facial, parotidectomy and temporal bone defects were retrospectively identified. Comparative statistics were used to analyze variables between the two cohorts, specifically operative time, flap size, length of stay, regional recurrence, disease free survival, and overall survival. ResultsNo significant difference in demographic and disease related variables was observed. Operative time was significantly lower in SIF group with mean of 412.9 (SD 93.4) minutes compared to 544.1 (SD 139.9) minutes in free flap group. Flap size was significantly larger in free tissue transfer, 32.4 (SD 17.5) cm2 (SIF) compared to mean area of 105.2 (SD 53.2) cm2 (Free tissue transfer). A significant difference in length of stay was also noted between groups. There was no regional recurrence of disease in level I–III in SIF group. There was no significant difference in DFS or OS between the two groups. ConclusionSIF is an oncologically sound option for reconstruction of lateral facial soft tissue, parotidectomy, and temporal bone defects.

Experience of treating patients with lateral sphenoid sinus recess CSF leak

The study purpose was to analyze our own experience in treating patients with CSF leak and meningoencephalocele in the lateral sphenoid sinus recess and, based on the obtained results, develop an algorithm for the treatment of this pathology. We retrospectively reviewed a series of 89 patients with CSF leak and meningoencephalocele in the lateral sphenoid sinus recess who were treated at the Burdenko Neurosurgical Institute in the period between 2001 and 2017. The demographic characteristics of patients, clinical data, and aspects of surgical treatment were analyzed. Treatment outcomes were assessed based on analysis of recurrences and postoperative complications. The obtained data were compared to the literature data. In the series of 89 patients with CSF leak and meningoencephalocele in the lateral sphenoid sinus recess, the mean age was 49 years. Surgery through the transsphenoid approach was performed in 89 (74%) patients. There were 25 (28%) recurrences in this group. Nine (7%) patients underwent repair of a complex skull base defect using the transethmoidal approach; there were 3 (33%) recurrences. The transpterygoid approach was used in 22 (17%) patients; there were 3 (14%) recurrences in this group. Endoscopic endonasal repair is an effective technique for treating complex skull base defects in the lateral sphenoid sinus recess. The choice of an approach to the defect depends on the degree of pneumatization of the sphenoid sinus, surgeon's experience, and availability of the necessary equipment and tools. The endoscopic transpterygoid approach is advisable to use in cases of excessive pneumatisation of the sinus with developed lateral processes and recurrent nasal CSF leak. This enables visualization of the defect edges in this hard-to-reach area and adequate repair.

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

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

Surgical technique for repair of complex anterior skull base defects.

Background:Modern microsurgical techniques enable en bloc resection of complex skull base tumors. Anterior cranial base surgery, particularly, has been associated with a high rate of postoperative cerebrospinal fluid (CSF) leak, meningitis, intracranial abscess, and pneumocephalus. We introduce simple modifications to already existing surgical strategies designed to minimize the incidence of postoperative CSF leak and associated morbidity and mortality.Methods:Medical records from 1995 to 2013 were reviewed in accordance with the Institutional Review Board. We identified 21 patients who underwent operations for repair of large anterior skull base defects following removal of sinonasal or intracranial pathology using standard craniofacial procedures. Patient charts were screened for CSF leak, meningitis, or intracranial abscess formation.Results:A total of 15 male and 6 female patients with an age range of 26–89 years were included. All patients were managed with the same operative technique for reconstruction of the frontal dura and skull base defect. Spinal drainage was used intraoperatively in all cases but the lumbar drain was removed at the end of each case in all patients. Only one patient required re-operation for repair of persistent CSF leak. None of the patients developed meningitis or intracranial abscess. There were no perioperative mortalities. Median follow-up was 10 months.Conclusion:The layered reconstruction of large anterior cranial fossa defects resulted in postoperative CSF leak in only 5% of the patients and represents a simple and effective closure option for skull base surgeons.

Anterior skull base defects - algorithm for reconstruction

After tumor surgery or traumatic defects the anterior skull base needs sufficient closure in order to prevent rhinoliquorrhea, ascending infection and brain tissue prolaps. Small defects are sufficiently closed by non-vital tissue, e. g. mucosa, muscle, fat, fascia, bone, allogenic, xenogenic or alloplastic material. Larger defects of the skull base often require more extensive surgery, including transfer of local or distal vascularized flaps. The current article presents a stepwise tutorial for reconstruction of the skull base and by a large case series focuses on the interdisciplinary therapy of complex (size, recurrence, after radiotherapy) skull base defects. Complex defects with small diameter, which can occur after extended sinus surgery, were permanently closed by local mucosa flaps of the lower turbinate or of the septum (n=31). Larger defects, e. g. after combined transcranial and endonasal tumor surgery, were closed by a 'sandwich technique' containing a galea periost flap and a calvarian split transfer (n=10). Reconstruction of the dura with fascia lata and local transfer of the temporal muscle were efficient for frontobasal defects with a more lateral location (n=4). Transfer of a distal desepithelialised vascularized forearm flap represents the ultimate procedure for reconstruction of large skull base defects, which was performed in 4 of our patients. Successive escalation of the therapy and integra-tion of the entire repertoire of plastic-reconstructive surgery allows for durable closure of complex skull base defects. In every case, close cooperation between ENT- and neurosurgeons is necessary for planning and performance of a successful surgical procedure.

Beyond the nasoseptal flap: Outcomes and pearls with secondary flaps in endoscopic endonasal skull base reconstruction

Endoscopic endonasal skull base surgery defects require effective reconstruction. Although the nasoseptal flap (NSF) has become our institution's workhorse for large skull base defects with cerebrospinal fluid (CSF) leaks, situations where it is unavailable require secondary flaps. Clinical outcomes, pearls and pitfalls, and an algorithm will be presented for these secondary flaps. Clinical case series. Medical records of all endoscopic endonasal skull base surgeries at a tertiary care academic medical center were reviewed for skull base defect type, reconstruction method, CSF leak rate, and flap necrosis rate. Of 330 flaps for reconstructing endoscopic endonasal skull base defects, secondary flaps were used in 34 cases (10%). These included 16 endoscopic-assisted pericranial flaps, seven tunneled temporoparietal fascia flaps, three inferior turbinate flaps, two middle turbinate flaps, two anterior lateral nasal wall flaps, two palatal flaps, one occipital flap, and one facial artery buccinator flap. There were 19 anterior cranial fossa defects, 10 clival defects, three sellar defects, and one frontal and one lateral orbit/middle fossa defect. Twenty-five of the 34 cases (73.5%) had either prior or postoperative radiation therapy. The most common pathology was sinonasal cancer, with 16 cases (47.1%). The postoperative CSF leak rate was 3.6% due to one middle turbinate flap necrosis. Secondary flaps for skull base reconstruction can be harvested with minimally invasive techniques and demonstrate excellent success rates (97%) that are comparable to that of the NSF (>95%). Multiple flaps for complex skull base defects should be in the armamentarium of comprehensive skull base surgery centers. 4.

The inferior turbinate flap in skull base reconstruction

BackgroundAs the indications for expanded endonasal approaches continue to evolve, alternative reconstructive techniques are needed to address increasingly complex surgical skull base defects. In the absence of the nasoseptal flap, we describe our experience with the posterior pedicle inferior turbinate flap (PPITF) in skull base reconstruction.DesignCase series.SettingAcademic tertiary care centre.MethodsPatients who underwent reconstruction of the skull base with the PPITF were identified. Medical records were reviewed for demographic, presentation, treatment, follow-up, surgical and outcomes data.Main outcome measuresFlap survival, adequacy of seal, and complications.ResultsTwo patients with residual/recurrent pituitary adenomas met the inclusion criteria. The nasoseptal flap was unavailable in each case due to a prior septectomy. Salvage of the original nasoseptal flap was not possible, as it did not provide adequate coverage of the resultant defect due to contraction from healing. All PPITFs healed uneventfully and covered the entire defect. No complications were observed in the early post-operative period. Endoscopic techniques and limitations of the PPITF are also discussed.ConclusionsOur clinical experience supports the PPITF to be a viable alternative for reconstruction of the skull base in the absence of the nasoseptal flap.

Radial Forearm Free Flap With Titanium Mesh Sandwich Reconstruction in Complex Anterior Skull Base Defects

Skull base reconstruction presents a number of challenges from anatomical and functional perspectives. This is especially the case with large anterior skull base defects with compromised recipient beds from repeated infection, multiple surgeries, or previous radiation. The purpose of the study was to demonstrate the use of the titanium mesh/radial forearm free flap (RFFF) mesh sandwich for reconstruction of large anterior skull base defects with a poor recipient bed or excessive bony defect. Retrospective case series of 3 patients with complex anterior skull base defects reconstructed with a titanium mesh/RFFF mesh sandwich technique. Reconstruction of 3 cases using the titanium mesh/RFFF sandwich technique resulted in definitive treatment with no recurrent cerebral spinal fluid leaks, meningitis, or complications. The titanium mesh/RFFF sandwich is an excellent reconstructive option for large anterior skull base defects with a poor recipient bed. This approach is facilitated using a combined open and endonasal endoscopic approach in a multidisciplinary team composed of head and neck surgery, rhinology, and neurosurgery.

Reconstructive indications of simultaneous double free flaps in the head and neck: A case series and literature review

Extensive and complex defects of the head and neck involving multiple anatomical and functional subunits are a reconstructive challenge. The purpose of this study is to elucidate the reconstructive indications of the use of simultaneous double free flaps in head and neck oncological surgery. This is a retrospective review of 21 consecutive cases of head and neck malignancies treated surgically with resection and reconstruction with simultaneous use of double free flaps. Nineteen of 21 patients had T4 primary tumor stage. Eleven patients had prior history of radiotherapy or chemo-radiotherapy. Forty-two free flaps were used in these patients. The predominant combination was that of free fibula osteo-cutaneous flap with free anterolateral thigh (ALT) fascio-cutaneous flap. The indications of the simultaneous use of double free flaps can be broadly classified as: (a) large oro-mandibular bone and soft tissue defects (n = 13), (b) large oro-mandibular soft tissue defects (n = 4), (c) complex skull-base defects (n = 2), and (d) dynamic total tongue reconstruction (n = 2). Flap survival rate was 95%. Median follow-up period was 11 months. Twelve patients were alive and free of disease at the end of the follow-up. Eighteen of 19 patients with oro-mandibular and glossectomy defects were able to resume an oral diet within two months while one patient remained gastrostomy dependant till his death due to disease not related to cancer. This patient had a combination of free fibula flap with free ALT flap, for an extensive oro-mandibular defect. The associated large defect involving the tongue accounted for the swallowing difficulty. Simultaneous use of double free flap aided the reconstruction in certain large complex defects after head and neck oncologic resections. Such combination permits better complex multiaxial subunit reconstruction. An algorithm for choice of flap combination for the appropriate indications is proposed.

Posterior Pedicle Lateral Nasal Wall Flap: New Reconstructive Technique for Large Defects of the Skull Base

Indications for expanded endoscopic approaches continue to grow, resulting in larger and more complex skull base defects. Reconstructive developments, however, have lagged our extirpative capabilities. As the complexity of clinical scenarios continues to escalate, challenging our current reconstructive strategies, we are compelled to develop alternative techniques to prevent cerebrospinal fluid leaks and protect neurovascular structures. In this article we show the anatomic basis for a new posterior pedicled flap from the lateral wall of the nose (Carrau-Hadad [C-H] flap) for the reconstruction of median skull base defects and present our early clinical experience. Using a cadaveric model, we designed a posterior pedicle flap comprising the nasal inferolateral wall mucoperiosteum. We applied this information clinically, to reconstruct transmural skull base defects. In our cadaveric model, we harvested and transposed C-H flaps into various defects of the planum sphenoidale, sella turcica, clivus, and nasopharynx. Then, we used the C-H flap in four patients, successfully reconstructing their clival (n = 3) and sellar (n = 1) surgical defects. All patients healed uneventfully. Our anatomic study and early clinical experience support the use of the posterior pedicle lateral nasal wall flap to reconstruct large cranial base defects resulting from endoscopic skull base surgery in properly selected patients.

Vascularized reconstruction of endoscopic skull base defects

Vascularized flap reconstruction is an effective reconstructive procedure for the management of complex skull base defects. The workhorse of endonasal reconstruction is the nasoseptal flap, which is a versatile pedicled flap with reliable vascularity that may be harvested using a purely endoscopic technique. Bilateral nasoseptal flaps may also be harvested for the coverage of very large defects. Several technical considerations may improve the ease of harvest and prevent postoperative complications. Vascularized flap reconstruction is an effective reconstructive procedure for the management of complex skull base defects. The workhorse of endonasal reconstruction is the nasoseptal flap, which is a versatile pedicled flap with reliable vascularity that may be harvested using a purely endoscopic technique. Bilateral nasoseptal flaps may also be harvested for the coverage of very large defects. Several technical considerations may improve the ease of harvest and prevent postoperative complications.

Patient Specific Implants (PSI) in complex skull base defects

Introduction: Complex cranio-facial defects present a reconstructive challenge following tumour resection or trauma. The technology to produce three dimensional patient specific implants (PSI) from various materials has matured allowing predictable reconstruction of complex defects. We present a case series in which polyetheretherketone (PEEK) PSIs were employed for this purpose.

How to Choose? Endoscopic Skull Base Reconstructive Options and Limitations

As endoscopic skull base resections have advanced, appropriate reconstruction has become paramount. The reconstructive options for the skull base include both avascular and vascular grafts. We review these and provide an algorithm for endoscopic skull base reconstruction. One hundred and sixty-six skull base dural defects, reconstructed with an endonasal vascular flap, were examined. As an adjunct, avascular reconstruction techniques are discussed to illustrate all options for endonasal skull base reconstruction. Cerebrospinal fluid (CSF) leak rates are also discussed. Small CSF leaks may be successfully repaired with various avascular grafting techniques. Endoscopic endonasal approaches (EEAs) to the skull base often have larger dural defects with high-flow CSF leaks. Success rates for some EEA procedures utilizing avascular grafts approach 90%, yet in high-flow leak situations, success rates are much lower (50 to 70%). Defect location and complexity guides vascularized flap choice. When nasoseptal flaps are unavailable, anterior/sellar defects are best managed with an endoscopically harvested pericranial flap, whereas clival/posterior defects may be reconstructed with an inferior turbinate or temporoparietal flap. An endonasal skull base reconstruction algorithm was constructed and points to increased use of various vascularized reconstructions for more complex skull base defects.