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BACKGROUND: Frontal craniotomies for a medial subfrontal approach necessitate crossing the frontal sinus. Large superior extensions of the frontal sinus into frontal bone can result in mucosal retention in a free craniotomy bone flap, leading to a delayed mucocele with significant associated morbidity. The authors describe an open-window craniectomy technique that permits mucosal removal under direct vision and maintains the inner table on the bone flaps inferior side, helping to seal off the sinus opening with a pericranial flap. OBSERVATIONS: An illustrative case involving a medial right frontal craniotomy for a third ventricle mass in a patient with a large superior extension of the frontal sinus into frontal bone is presented. After creating a free frontal bone flap, the inner table was drilled out to the margins of the frontal sinus cavity and any remaining mucosa was cleared. A portion of the inner table above the bone flaps inferior margin was left in place, resembling an open window when viewed from the inner table side. The remaining anterior and posterior wall of the flap inferiorly provided a matched surface for the opening into the remaining frontal sinus, which was covered by pericranium. Long-term follow-up indicated no major complications or delayed mucocele. LESSONS: The open-window craniectomy technique can be considered for frontal sinus violations in patients with large superior frontal bone extension.

The article discusses the outcomes of using autologous versus synthetic inlay grafts for skull base reconstruction in patients with high-flow defects. The study involved a multicenter case-control analysis and found comparable rates of postoperative cerebrospinal fluid leaks between the two types of grafts. The research highlights the importance of meticulous technique over specific tissue type and emphasizes the need to balance the availability and cost of synthetic materials with donor site morbidity in autologous grafts. The study provides valuable insights for surgeons performing skull base reconstructions. [Extracted from the article]

Background and Objectives: The temporoparietal fascia flap (TPFF) has recently emerged as an option for skull base reconstruction in endoscopic transnasal surgery when vascularized nasal flaps are not available. This study provides a systematic literature review of its use in skull base surgery and describes a novel cohort of patients. Methods: PRISMA guidelines were used for the review. Patients undergoing skull base reconstruction with TPFF in our center from May 2022 to April 2024 were retrospectively included. Data were collected on pre- and post-operative clinical and radiological features, histology, surgical procedures, and complications. Results: Sixteen articles were selected, comprising 42 patients who underwent TPFF reconstruction for treatment of complex skull base pathologies. In total, 5 of 358 patients (0.9%) who underwent tumor resection via endoscopic transanal surgery in the study period in our institution required TPFF. All had been previously treated with surgery and radiation therapy for different pathologies (three chordomas, one giant pituitary neuroendocrine tumor (PitNET), and one sarcoma). Post-operative complications included CSF leak, which resolved after flap revision, and an internal carotid artery pseudoaneurysm requiring endovascular embolization. Conclusions: TPFF is an effective option for skull base reconstruction in complex cases and should be part of the armamentarium of the skull base surgeon. [ABSTRACT FROM AUTHOR]

To verify the feasibility and discuss advantages and disadvantages of a piezoelectric orbitotomy during superior eyelid endoscopic transorbital approach (SETOA). An illustrative case demonstrating the application of this novel technique is also presented. Exoscopic/endoscopic SETOA to middle cranial fossa was performed on 5 adult specimens. The surgical corridor was created via piezoelectric orbitotomy by performing 3 selective and safe micrometric bone cuts providing a 1-piece trapezoid bone flap, which was repositioned and secured at the end of the procedure. A three-dimensional scan of the bone flap allowed us to reconstruct a three-dimensional model and calculate its volume. Anatomical-morphometric quantitative analysis showed a mean bone volume gain of 1574.26 mm3 by using piezoelectric orbitotomy. Piezoelectric orbitotomy also yielded concrete surgical advantages and theoretical benefits in terms of functional and esthetic outcomes. All osteotomies were micrometric clear-cut and precise, resulting in a very thin bone gap; complete sparing of soft tissues and neurovascular structures in and around the orbit was observed. Lateral orbital wall reconstruction by replacing the bone flap was performed to mitigate the risk of enophthalmos, proptosis, cerebrospinal leakage, pseudomeningocele, and pulsatile headache, which represent significant challenges. Piezoelectric orbitotomy may offer a viable, selective, effective, safe alternative to high-speed drilling during SETOA, especially for patients with intra-axial pathologies, in which a watertight closure is mandatory. This procedure could prevent or decrease the risk of some of the main postoperative complications associated with standard SETOA, potentially resulting in better functional and esthetic outcomes. [ABSTRACT FROM AUTHOR]

The goal of this American Rhinologic Society expert practice statement (EPS) is to summarize the best available evidence regarding postoperative precautions for patients following endoscopic skull base surgery for intradural pathology. These topics include the administration of postoperative nasal hygiene; patient mobilization and activity level; the resumption of continuous positive airway pressure in patients with obstructive sleep apnea; and the timing and capacity with which a patient may be subjected to barotrauma, such as air travel postoperatively. This EPS was developed following the recommended methodology and approval process as previously outlined. Given the diverse practices and limited agreement on the accepted principles regarding postoperative precautions for patients following skull base surgery, this EPS seeks to summarize the existing literature and provide clinically relevant guidance to bring clarity to these differing practice patterns. Following a modified Delphi approach, four statements were developed, all of which reached consensus. Because of the paucity of literature on these topics, these statements represent a summation of the limited literature and the experts' opinions. These statements and the accompanying evidence are summarized below, along with an assessment of future needs. [ABSTRACT FROM AUTHOR]

Reconstruction after the resection of sinonasal malignancies is complex and primarily dependent on the defect size and location. While the reconstructive paradigm for sellar mass resection is well delineated, the challenges associated with reconstruction after sinonasal malignancy resection are less well described. This narrative review will address the goals of reconstruction after both endonasal endoscopic and open sinonasal malignancy resection and reconstructive options specific to these subsites. The goals of reconstruction include repairing cerebrospinal fluid leaks, restoring sinonasal function, providing a nasal airway, and optimizing the patients quality of life. These goals are often complicated by the anatomic nuances of each involved sinus. In this review, we will discuss the methods of reconstruction specific to each sinonasal subsite and describe the factors that guide choosing the optimal reconstructive technique.

Objectives Our objective was to determine if decreased contrast enhancement on postoperative magnetic resonance imaging (MRI) is associated with an increased risk of complication in patients who have undergone nasoseptal flap (NSF) reconstruction. Design/Setting This was a single-institution retrospective study of patients who underwent a first-time endoscopic endonasal approach (EEA) with NSF reconstruction. Participants Patients underwent an EEA to the skull base with NSF reconstruction and received postoperative MRI within 3 weeks of the operation. Main Outcome Measures MR exams were scored on the degree of contrast enhancement at first postoperative MRI. An enhancement score of 4 indicated ≥75% enhancement of the NSF. A score of 3 indicated enhancement ≥50% and <75% enhancement of the NSF. A score of 2 indicated ≥25% and <50% enhancement of the NSF. Complications (e.g., cerebrospinal fluid [CSF] leak, meningitis, empyema, cerebritis, brain abscess, flap necrosis, and flap migration) were retrieved from our institution's skull base database. Logistic regression was used to determine the effect of the MRI enhancement score on the odds of developing a complication. Results Out of 99 patients in the study, six had complications. Patients who underwent NSF reconstruction of skull base defects were found to have 19 times higher odds of complication (p = 0.007) if they had had an NSF enhancement score of 2 on their postoperative MRI when compared with patients with complete or near complete NSF enhancement (score 4). Conclusion Quantifying NSF enhancement with an MRI may help surgeons better predict which of their patients are at an increased risk of complication. [ABSTRACT FROM AUTHOR]

As the indications for endoscopic skull base approaches have increased, so has the need for more versatile vascularized flaps for skull base reconstruction. Here, we describe a novel lateral based nasopharyngeal flap (LNPF). Two cadaver heads were dissected to elucidate flap anatomy, dimensions, and technique. A retrospective review was performed on two cases where LNPF was used to repair CSF leaks in the nasopharyngeal area, and outcomes reported. The LNPF is an ascending pharyngeal artery myomucosal flap that includes the nasopharyngeal mucosa and the superior pharyngeal constrictor muscle. The flap was 1.2 × 2.2 cm in greatest dimensions. The LNPF was used for salvage CSF leak repair in two cases: one clival and one tubal. Both patients had resolution of leak at 7 months follow‐up. The LNPF is a novel flap with reconstruction potential for the nasopharynx, including the lower clivus and the eustachian tube. [ABSTRACT FROM AUTHOR]

Various nonvascularized or vascularized techniques have been adopted in endoscopic endonasal surgery (EES) for repairing intraoperative cerebrospinal fluid (CSF) leaks after tumor resection. Vascularized nasoseptal flaps, free nasoseptal grafts, free turbinate grafts, and fascia lata and mashed muscle are frequently used. Outcomes of those grafts applied in the defects of different regions need to be clarified. The data from a series of 162 patients with skull base tumor who underwent EES that had intraoperative CSF leak between Jan 2012 and Jan 2021 were retrospectively analyzed. The regions included anterior skull base, sellar region, clivus and infratemporal fossa. Repair failure rate (RFR), meningitis rate, and associated risk factors were assessed. In total, 172 reconstructions were performed in 162 patients for the 4 sites of the skull base. There were 7 cases (4.3%) that had postoperative CSF leaks, which required second repair. The RFR for anterior skull base, sellar region, clivus, and infratemporal fossawas 2.6%, 2.2%, 16.7%, and 0%, respectively. The clivus defect was an independent risk factor for repair failure (P < 0.01). The postoperative meningitis rate was 5.6%. Repair failure was an independent risk factor for meningitis (P < 0.01). Vascularized nasoseptal flap, free nasoseptal graft, free turbinate graft, and fascia lata and mashed muscle are reliable autologous materials for repairing the dural defects in different regions during EES. Clivus reconstruction remains a great challenge, which had a higher RFR and meningitis rate. Repair failure is significantly associated with postoperative meningitis. [ABSTRACT FROM AUTHOR]

Background: Postoperative cerebrospinal fluid (CSF) leak remains a concerning complication of the endoscopic endonasal approach (EEA) for skull base pathology. Signs and symptoms suggesting CSF leak often trigger additional workup during the postoperative course. We systematically evaluate associations between subjectively reported clinical signs/symptoms noted during the immediate postoperative period and incidence of postoperative CSF leaks. Methods: Retrospective chart review was conducted at a tertiary academic medical centre including 137 consecutive patients with intraoperative CSF leak during EEA with primary repair between July 2018 and August 2022. Postoperative CSF leak associations with clinical signs and symptoms were evaluated using positive (PPV) and negative predictive values (NPV), sensitivity, specificity and odds ratio (OR) via univariate logistic regression. Results: Seventy‐nine patients (57.7%) had high‐flow leaks repaired and 5 (3.6%) developed CSF leaks postoperatively. Of reported symptoms, rhinorrhea was most common (n = 52, 38.0%; PPV [95% CI] = 7.6% [4.8%, 11.9%]), followed by severe headache (n = 47, 34.3%; 6.3% [3.1%, 12.5%]), dizziness (n = 43, 31.4%; 2.3% [0.4%, 12.1%]), salty or metallic taste (n = 20, 14.6%; 9.9% [3.3%, 25.8%]), and throat drainage (n = 10, 7.3%; 9.9% [1.7%, 41.4%]). Nausea or vomiting constituted the most reported sign concerning for CSF leak (n = 73, 53.3%; PPV [95% CI] = 4.1% [2.0%, 8.1%]). On univariate regression, no sign or symptom, including rhinorrhea (OR [95% CI] = 7.00 [0.76–64.44]), throat drainage (3.42 [0.35–33.86]), salty/metallic taste (4.22 [0.66–27.04]), severe headache (3.00 [0.48–18.62]), dizziness (0.54 [0.06–4.94]), fever (3.16 [0.50–19.99]), and nausea/vomiting (1.33 [0.22–8.21]), associated with postoperative CSF leak. Conclusions: A range of subjectively reported symptoms and signs failed to predict postoperative CSF leak. Further investigation is warranted to inform appropriate attention and response. [ABSTRACT FROM AUTHOR]

The goal of this American Rhinologic Society expert practice statement (EPS) is to summarize the best available evidence for technical factors that optimize outcomes in skull base reconstruction following endoscopic skull base surgery for intradural pathologies. These topics include the use of free mucosal grafts versus vascularized pedicled nasoseptal flaps; the use of autologous versus synthetic grafts; and the roles of lumbar drains, dural sealants, and nasal packing. This EPS was developed following the recommended methodology and approval process as previously outlined. As there are a myriad of techniques and limited agreement on the accepted principles of skull base reconstruction, this EPS aims to summarize the existing evidence and provide clinically meaningful guidance on these divergent practices. Following a modified Delphi approach, five statements were developed, four of which reached consensus and one of which reached near consensus. These statements and the accompanying evidence are summarized along with an assessment of future needs. [ABSTRACT FROM AUTHOR]

Background: Data from patients with post‐ablative dural defects reconstructed using a free temporalis muscle fascia graft (FTFG) after resection of anterior or central skull base tumors were retrospectively analyzed. Methods: The primary predictor and outcome variables were the reconstructive methods for dural repair and postoperative cerebrospinal fluid (CSF) leakage rate, respectively. Results: Eighty patients were included, and 94 postoperative dural reconstructions were performed using FTFG. The postoperative CSF leakage rate was 3.19%. The postoperative CSF leakage rates did not significantly differ between open and endonasal endoscopic surgeries (1.92% vs. 4.88%; p > 0.05). In cases completed using the endonasal endoscopic approach, the postoperative CSF leakage rate was significantly associated with the intraoperative CSF leak flow (p < 0.05). Conclusions: Post‐ablative dural defect reconstruction using FTFG resulted in low postoperative CSF leakage and complication rates comparable to those of free fascia lata graft from available literature. [ABSTRACT FROM AUTHOR]

Background: Postoperative imaging after nasopharyngeal endoscopic resection (NER) and skull base reconstruction is quite challenging due to the complexity of the post-surgical and regional anatomy. Methods: In this retrospective observational study, we included patients treated with NER from 2009 to 2019 and submitted to Magnetic Resonance Imaging (MRI) 6 and 12 months after surgery. A radiologist with 15 years of experience analyzed all MRI scans. Results: A total of 50 patients were considered in this study, 18 of whom were excluded due to imaging unavailability, and 16 of whom were not considered due to major complications and/or persistent disease. Sixteen patients were evaluated to identify the expected findings. Inflammatory changes were observed in 16/64 subsites, and regression of these changes was observed in 8/64 at 1 year. Fibrosis was observed in 5/64 subsites and was unmodified at 1 year. The nasoseptal flap showed homogeneous enhancement at 6 months (100%) and at 1 year. The temporo-parietal fascia flap (TPFF) showed a decrease in the T2- signal intensity of the mucosal layer in 57% of the patients at 1 year and a decrease in enhancement in 43%. Conclusions: Identifying the expected findings after NER and skull base reconstruction has a pivotal role in the identification of complications and recurrence. [ABSTRACT FROM AUTHOR]

Background: Advanced surgical interventions are required to treat malignancies in the anterior skull base (ASB). This study investigates the utility of endoscopic endonasal and transcranial surgery (EETS) using a high‐definition three‐dimensional exoscope as an alternative to traditional microscopy. Methods: Six patients with carcinomas of varying histopathologies underwent surgery employing the EETS maneuver, which synchronized three distinct surgical modalities: harvesting of the anterolateral thigh flap, initiation of the transnasal technique, and initiation of the transcranial procedure. Results: The innovative strategy enabled successful tumor resection and skull base reconstruction without postoperative local neoplastic recurrence, cerebrospinal fluid leakage, or neurological deficits. Conclusion: The integration of the exoscope and EETS is a novel therapeutic approach for ASB malignancies. This strategy demonstrates the potential of the exoscope in augmenting surgical visualization, enhancing ergonomics, and achieving seamless alignment of multiple surgical interventions. This technique represents a progressive shift in the management of these complex oncological challenges. [ABSTRACT FROM AUTHOR]

Abstract Objective Skull base defects can be challenging to reconstruct. The nasoseptal flap (NSF) remains the first‐line option for reconstruction. However, it can be inadequate to cover wide defects or compromised by tumor invasion or prior surgery requiring additional reconstructive options. The goal of the study is to describe a novel flap for clival and craniovertebral junction (CVJ) reconstruction. Study Design Cadaveric study with an illustrative clinical case. Setting Cadaver dissection laboratory and tertiary university hospital. Methods Endoscopic endonasal dissection was performed in 15 cadavers. A modification of the inferior incision of the NSF was carried out. The inferior incision was performed at a more cranial location, sparing the mucosa of the posterior septum. Two lateral longitudinal incisions were carried out at the pterygo‐sphenoidal junction freeing the nasopharyngeal mucosa. A third incision was performed separating the rostral mucosa from the nasal floor. The resulting flap was rotated postero‐superiorly covering the clivus and CVJ. Results An inferiorly based butterfly‐shaped nasopharyngo‐septal flap, consisting of nasopharyngeal and posterior septal mucosa and receiving blood supply from the bilateral ascending pharyngeal arteries, was formulated. The lower wings comprised nasopharyngeal mucosa while the upper wings comprised posterior septal mucosa. The mean surface area of the flap was 12.35 ± 0.21 cm2 covering the clivus and CVJ in all cadavers. Conclusion The nasopharyngo‐septal flap is a novel vascularized flap that is well‐suited for reconstructing clival and CVJ defects where the NSF is insufficient and can also be used as a salvage flap in cases where the NSF is unobtainable.

Skull base defects following resection of anterior cranial fossa and sinonasal tumors are not uncommon. Advances in endoscopic techniques have allowed for entirely endonasal resection and reconstruction of these tumors. This article discusses techniques in the evaluation and management of anterior skull base defects.

• The endoscopic endonasal approach (EEA) to olfactory groove meningioma (OGM) resection provides a high gross total resection rate, comparable to that of open resection. • Rates of cerebrospinal fluid leakage following EEA resection have significantly decreased and no longer favor open resection. • Although rates of post-operative anosmia with EEA remain high, smell preservation is a possibility with select cases. • Lack of tumor extension beyond the mid-orbit and the presence of significant peri -tumoral edema may favor resection via EEA. Though the endoscopic endonasal approach (EEA) is a widely accepted treatment for skull base tumors, the specific use of EEA for olfactory groove meningiomas (OGMs) is debated, with variable outcomes reported in the literature. We review the surgical results of OGM resections for one surgeon including the operative approach, surgical nuances, and outcomes, with a focus on factors relating to patient selection which favor EEA over transcranial approaches. We retrospectively reviewed thirteen cases of endoscopic endonasal resection of olfactory groove meningiomas. Patient characteristics, clinical characteristics, surgical outcomes, and complications were analyzed. Extent of resection was determined based on volumetric analysis of pre- and postoperative MRI. Anatomic characteristics that render a tumor difficult to access fully are lateral extension beyond the mid-orbit and anterior extension to the falx. Simpson Grade I resection was achieved in 11/13 (84.6 %) cases. Mean pre-operative tumor volume was 8.99 cm3 (range 2.19–16.79 cm3), and 92 % of tumors were WHO grade I. We demonstrate 2 cases of smell preservation, possible with small unilateral tumors and tumors that are confined to either the anterior or posterior portion of the cribriform plate. The post-operative CSF leak rate was 7.7 %, without prophylactic lumbar CSF drainage. The mortality rate was 7.7 % (n = 1) after infectious complications following CSF leak. Endoscopic endonasal resection of olfactory groove meningiomas is an effective and safe operative method with outcomes and complication rates comparable to transcranial approaches. Key considerations include careful patient selection and familiarity with technical nuances of endoscopic endonasal approach for this specific tumor type. [ABSTRACT FROM AUTHOR]

With the advancement of endoscopic endonasal surgery in the treatment of anterior skull base (ASB) pathologies, extended, watertight reconstructions are needed to prevent cerebrospinal fluid (CSF) leakage. This often involves the use of multilayers closure, with free fascia lata (FL) graft frequently used as an in- and/or outlay. However, positioning the FL properly can be challenging and time-consuming, particularly on wider defects. In this technical note, we present an easier and faster way to position FL using a silicone sheet. FL graft is harvested using a standard technique. The required dimensions are evaluated depending on the extent of the dural defect taking in consideration that FL graft should exceed the edges of the dural defect especially laterally. It is then wrapped around a semi rigid pattern (Silastic sheet) and secured with several monofilament 5/0 sutures. The "package" is transferred through the endonasal corridor to the defect. The sutures are divided and taken out; the fascia is unfolded, and its edges are inserted into the subdural space without any twisting or folding of the flap. Finally, the silicone sheet is withdrawn from the nasal cavity, leaving the FL well-stretched in perfect position. We illustrate this technique in the management of a large anterior skull base chondrosarcoma, which necessitated significant bone and dural resection. The "Gift wrap" technique offers an alternative approach for positioning the FL, which is less time-consuming compared to the traditional technique. Moreover, it enables improved placement of the FL, enhancing its efficacy. [ABSTRACT FROM AUTHOR]

Background and Objectives: Skull base reconstruction is a crucial step during transsphenoidal surgery. Sphenoid mucosa is a mucosal membrane located in the sphenoid sinus. Preservation and lateral shifting of sphenoid mucosa as sphenoid mucosal flap (SMF) during the transsphenoidal exposure of the sella may be important for later closure. This is the first systematic review to evaluate the utility of sphenoid mucosal flap for sellar reconstruction after transsphenoidal surgery. Materials and Methods: A systematic literature search was performed in January 2023: Cochrane, EMBASE, PubMed, Scopus, and Web of Science. The following keywords and their combinations were used: "sphenoid mucosa", "sphenoid sinus mucosa", "sphenoid mucosal flap", "sphenoid sinus mucosal flap". From a total number of 749 records, 10 articles involving 1671 patients were included in our systematic review. Results: Sphenoid sinus mucosa used to be applied for sellar reconstruction as either a vascularized pedicled flap or as a free flap. Three different types of mucosal flaps, an intersinus septal flap, a superiorly based flap and an inferiorly based flap, were described in the literature. Total SMF covering compared to partial or no SMF covering in sellar floor reconstruction resulted in fewer postoperative CSF leaks (p = 0.008) and a shorter duration of the postoperative lumbar drain (p = 0.003), if applied. Total or partial SMF resulted in fewer local complications (p = 0.012), such as fat graft necrosis, bone graft necrosis, sinusitis or fungal infection, in contrast to no SMF implementation. Conclusions: SMF seems to be an effective technique for skull base reconstruction after transsphenoidal surgery, as it can reduce the usage of avascular grafts such as fat along with the incidence of local complications, such as fat graft necrosis, bone graft necrosis, sinusitis and fungal infection, or it may improve the sinonasal quality of life by maintaining favorable wound healing through vascular flap and promote the normalization of the sphenoid sinus posterior wall. Further clinical studies evaluating sphenoid mucosal flap preservation and application in combination with other techniques, particularly for higher-grade CSF leaks, are required. [ABSTRACT FROM AUTHOR]

AbstractMeningoencephalocele (MEC) is a rare clinical entity caused by herniation of the dura mater and brain tissue through bony defects in the skull base. We herein report a case of bilateral MECs found after recurrent bacterial meningitis. The patient subsequently underwent simultaneous bilateral resection of the MECs and repair of the lateral skull base using a combined mastoid-middle cranial fossa approach. The bone and dura were reconstructed using free bone grafts and a temporalis fascia flap. Three years after surgery, temporal bone computed tomography showed that the reconstructed tegmen was preserved bilaterally, and there was no recurrence of meningitis or MECs. The appropriate surgical approach should be chosen based on the localization and size of the herniated tissue, and the presence of active infection or other coexisting pathology. Simultaneous bilateral resection using the combined mastoid-middle cranial fossa approach is a promising option for the treatment of bilateral multiple MECs.

Abstract Background There have been several reconstructive methods with free flaps or vascular pedicled flaps constituting a large portion of the rebuilding of the skull base. The vascularized pedicled nasoseptal flap, however, appears to be the “gold standard” flap in the restoration of the integrity of the cranial base among all of the foregoing alternatives. This study aimed to assess the postoperative outcomes of endoscopic removal of large midline skull base tumors with nasoseptal flap reconstruction in 21 patients. Patients were assessed at 1 week postoperative using Sinonasal Outcome Test 22 (SNOT 22) to assess postoperative nasal symptoms. An endoscopic assessment of the nose was done at 1 week postoperative to assess the degree of crusting and at 4 weeks postoperative to assess the degree of nasal adhesions and the presence or absence of gangrene of the nasoseptal flap. Postoperative complications were assessed. Results The study patients included 12 cases with pituitary macroadenoma, five cases with anterior cranial fossa meningioma, and four cases with petroclival chordoma. The skull base defect size ranged from 2.5 to 4.5 cm. The most troublesome postoperative symptoms were decreased sense of smell/taste. Postoperatively, 10 patients had mild, 7 patients had moderate, and 4 patients had severe nasal crusting. Three cases had epistaxis and two cases had postoperative cerebrospinal fluid rhinorrhea. Ten cases had no nasal adhesions, four cases had mild, four cases had moderate, and three cases had severe nasal adhesions. No cases had gangrene of the nasoseptal flap. Conclusion The nasoseptal flap is an effective option for large skull base defect reconstruction after endoscopic resection of large skull base tumors with an acceptable postoperative patient quality of life and a low incidence of postoperative complications.

Background: With a rising incidence of cerebrospinal fluid (CSF) leaks, endoscopic endonasal CSF leak repair is increasingly performed. Current approaches utilize a variety of materials including free mucosal grafts and vascularized flaps, but post-op leaks continue to be reported. Steroid-eluting bioabsorbable stents (SES) are used during functional endoscopic sinus surgery for chronic rhinosinusitis to reduce inflammation and scarring while maintaining patency of sinus ostia. Objective: The aim of this study is to assess the feasibility of SES as a graft/flap bolster for endoscopic endonasal CSF leak repair. Methods: This is a retrospective review of patients undergoing endoscopic endonasal CSF leak repair with SES placed as part of the bolster technique at a tertiary care center between January 2019 and May 2022. Age, sex, BMI, comorbid idiopathic intracranial hypertension, pathology, location of CSF leak, intraoperative CSF leak flow, reconstruction type, and presence of post-op CSF leak were recorded. Results: Twelve patients (mean age 52, median BMI 30.9, 58% female) had SES placement as part of the bolster technique. The most common pathology was meningoencephalocele (75%). Reconstruction was performed with either a free mucosal graft (6), or a flap (6). No post-op CSF leaks occurred at a reconstruction site with a stent, and no known complications were reported. All sinusotomies were patent at the last follow-up visit. Conclusions: SES placement as an adjunct to graft and/or flap bolster appears to be safe and feasible during anterior skull base reconstruction and CSF leak repair providing longer term structural support and preserving sinus drainage patency. [ABSTRACT FROM AUTHOR]

Meningoencephalocele (MEC) is a rare clinical entity caused by herniation of the dura mater and brain tissue through bony defects in the skull base. We herein report a case of bilateral MECs found after recurrent bacterial meningitis. The patient subsequently underwent simultaneous bilateral resection of the MECs and repair of the lateral skull base using a combined mastoid-middle cranial fossa approach. The bone and dura were reconstructed using free bone grafts and a temporalis fascia flap. Three years after surgery, temporal bone computed tomography showed that the reconstructed tegmen was preserved bilaterally, and there was no recurrence of meningitis or MECs. The appropriate surgical approach should be chosen based on the localization and size of the herniated tissue, and the presence of active infection or other coexisting pathology. Simultaneous bilateral resection using the combined mastoid-middle cranial fossa approach is a promising option for the treatment of bilateral multiple MECs. [ABSTRACT FROM AUTHOR]

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During the past decades, different methods have been described for anterior skull base reconstruction. Regarding larger skull base defects, few investigators have described the use of bone grafts to foster support and prevent frontal lobe sagging, herniation, or falling. The aim of this study is to describe the use of a rib bone graft, which could be an option in these cases due to its rigidity and dimensions. We retrospectively collected preoperative, intraoperative, and postoperative data at the last follow-up of 10 patients who underwent multilayer anterior skull base reconstruction, including rib bone graft, for large anterior cranial base defects at 2 tertiary care academic hospitals. Eight patients underwent endoscopic craniectomy for sinonasal malignancies, and the other two underwent transnasal endoscopic surgery for congenital meningoencephalocele. Anterior skull base defects measured on average 3.8 cm ± 0.9 SD antero-posteriorly (range 2.5–5 cm) and 2.3 ± 0.9 SD latero-laterally (range 0.9–4 cm). Multilayer reconstruction was performed in all cases, including a rib bone graft positioned as intracranial extradural layer. No patient experienced thoracic complications during the postoperative period. No side effects related to the bone graft or meningoencephalocele occurrence were reported after a mean follow-up of 8.0 ± 6.3 months. The use of a cortical rib bone graft could be a safe and effective option in skull base reconstruction when managing large defects after cancer removal. [ABSTRACT FROM AUTHOR]

Objective: Radiation osteonecrosis of the skull base after radiotherapy for nasopharyngeal carcinoma is one of the most serious complications, affecting patient survival and quality of life. To date, surgical resection is the main treatment for radiation osteonecrosis. The repair after the operation is very important. Inappropriate repair or lack of repair can easily cause local infection that can even spread to the brain, aggravating osteonecrosis. This study aimed to verify the feasibility and safety of the anterolateral thigh free fascia flap in repairing large skull base defects. Methods: From June 2021 to July 2022, a total of 12 patients with a history of radiotherapy for nasopharyngeal carcinoma received surgical treatment at the Department of Otolaryngology Head & Neck Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine. All patients were diagnosed with radiation osteonecrosis of the skull base with large skull base defects. During the endoscopic operation, a free anterolateral thigh fascia flap was used to repair the skull base and complete vascular anastomosis reconstruction. The preoperative and postoperative pain scores were retrospectively analyzed, and the dynamic changes in endoscopic surgery sites were observed. Results: The 12 patients had a median age of 58 y, with 8 (66.7%) males and 4 (33.3%) females. The median headache score for the patients was 5 (4–7) before surgery. The patient's headache was significantly relieved postoperatively, with 11 patients having a score of 0 and one patient having a score of 1. The stench was completely resolved after the operation. There were no serious complications during the perioperative period or 12 months after the operation. Conclusion: The application of anterolateral thigh free fascia flap in skull base reconstruction is a safe and reliable reconstruction technique suitable for endoscopic surgical repair of large-scale skull base necrosis.

Background: There have been several reconstructive methods with free flaps or vascular pedicled flaps constituting a large portion of the rebuilding of the skull base. The vascularized pedicled nasoseptal flap, however, appears to be the "gold standard" flap in the restoration of the integrity of the cranial base among all of the foregoing alternatives. This study aimed to assess the postoperative outcomes of endoscopic removal of large midline skull base tumors with nasoseptal flap reconstruction in 21 patients. Patients were assessed at 1 week postoperative using Sinonasal Outcome Test 22 (SNOT 22) to assess postoperative nasal symptoms. An endoscopic assessment of the nose was done at 1 week postoperative to assess the degree of crusting and at 4 weeks postoperative to assess the degree of nasal adhesions and the presence or absence of gangrene of the nasoseptal flap. Postoperative complications were assessed. Results: The study patients included 12 cases with pituitary macroadenoma, five cases with anterior cranial fossa meningioma, and four cases with petroclival chordoma. The skull base defect size ranged from 2.5 to 4.5 cm. The most troublesome postoperative symptoms were decreased sense of smell/taste. Postoperatively, 10 patients had mild, 7 patients had moderate, and 4 patients had severe nasal crusting. Three cases had epistaxis and two cases had postoperative cerebrospinal fluid rhinorrhea. Ten cases had no nasal adhesions, four cases had mild, four cases had moderate, and three cases had severe nasal adhesions. No cases had gangrene of the nasoseptal flap. Conclusion: The nasoseptal flap is an effective option for large skull base defect reconstruction after endoscopic resection of large skull base tumors with an acceptable postoperative patient quality of life and a low incidence of postoperative complications. [ABSTRACT FROM AUTHOR]

Key Clinical Message: The reuse of the nasoseptal flap represents a favorable option for skull base reconstruction in revision endoscopic anterior skull base surgery. This study demonstrated that a detached nasoseptal flap can remain viable for several days even if not immediately reattached. [ABSTRACT FROM AUTHOR]

Objectives: Is intradural fat graft packing indispensable in preventing postoperative cerebrospinal fluid leakage in endoscopic endonasal pituitary adenoma surgeries? This study aimed to review the methods and outcomes of our graded sellar floor reconstruction strategy without fat graft packing in endoscopic endonasal pituitary adenoma surgeries. Methods: From March 2018 to December 2022, 200 patients underwent endoscopic endonasal pituitary adenoma resection by a single author in our institute. We applied different graded skull base reconstruction strategies in different periods. Intradural fat graft packing was used to reconstruct the skull base in the early period, from March 2018 to June 2019, but fat graft was not used in the late period, from January 2020 to December 2022. The effect of these different graded skull base reconstruction strategies and whether intradural fat graft packing is necessary were evaluated by observing the incidence of postoperative cerebrospinal fluid leak. Results: In the early period, fat graft was used to reconstruct skull base when the intraoperative cerebrospinal fluid (CSF) leakage existed. There were two patients who suffered from postoperative cerebrospinal fluid leak in this group. In the late period, fat graft was not used to reconstruct the skull base, and no patient suffered from postoperative cerebrospinal fluid leakage in this group. Conclusions: Intradural fat graft packing is unnecessary in the endoscopic endonasal pituitary adenoma resection. The outcome of our graded sellar floor reconstruction strategy is satisfactory. [ABSTRACT FROM AUTHOR]

Background: Multilayer closures and the use of vascularized flaps have been showed to be very effective in the reconstruction of the anterior skull base (ASB) after extended endonasal approaches resulting in large bone and dural defects. In the case of unavailability of a local flap, regional ones like the temporoparietal fascia flap (TPFF), used until now via a transpterygoïd route (Bolzoni Villaret et al. in Eur Arch Otorhinolaryngol 270(4):1473–1479, 2023; Fortes et al. in Laryngoscope 117(6):970–976, 2017; Veyrat et al. in Acta Neurochir (Wien) 158(12):2291–2294, 2016), can be an effective alternative. Method: We describe a step-by-step technique of TPFF transposition via an epidural supraorbital corridor for the reconstruction of a large midline ASB defect. Conclusion: TPFF is a promising alternative for the reconstruction of the ASB defects. [ABSTRACT FROM AUTHOR]

ABSTRACT Importance The safety and efficacy of the bath‐plug technique for the closure of cerebrospinal fluid (CSF) leaks in children remain unknown. Objective We undertook this study to ascertain whether the bath‐plug technique was safe and effective for the repair of CSF leaks. Methods We retrospectively reviewed patients who underwent endoscopic repair of CSF leaks with the fat graft as a plug‐in at Beijing Children's Hospital from March 2016 to May 2020. Demographic data, medical history, defect sites and sizes, interventions, and clinical outcomes were analyzed. One representative clinical case was additionally selected to highlight the procedure and the healing process. Results A total of 18 pediatric patients were included in this study. The group was composed of 11 boys and seven girls, aged from 5 to 123 months. The etiologies included congenital CSF leaks (n = 9) and head trauma (n = 9). Among all patients, 12 fistulas (66.7%) were located at the cribriform plate area, two (11.1%) at the roof of the ethmoid sinuses, two (11.1%) in the sphenoid sinus, and two (11.1%) at the frontal sinus. The maximum diameters of fistulas ranged from 5 to 20 mm, with a median value of 8 mm. Encephaloceles were identified in 14 (77.8%) patients. No hydrocephalus was recognized. All CSF leaks were successfully repaired with a bath‐plug technique. Follow‐up ranged from 50 to 70 months. No surgical complications were encountered in any patient. Interpretation Bath‐plug technique is safe and reliable for the endoscopic management of CSF leaks in children. Meticulous peri‐operative preparations are important for pediatric patients.

Abstract Objective Expanded endonasal approaches (EEAs) to the skull base have increased the scope and extent of pathologies that can be treated endoscopically. The trade‐off is creation of large skull base bone defects requiring reconstruction to re‐establish barriers between the sino‐nasal mucosa and subarachnoid space to prevent CSF leak and infection. A popular reconstructive technique is the local vascularized pedicled naso‐septal flap, an option that may not always be possible when there is disruption of the vascular pedicle from multiple previous surgeries, adjuvant radiotherapy or extensive tumor infiltration. An alternative is the regional temporo‐parietal fascial flap (TPFF) transposed via the trans‐pterygoid route. We implemented a modification of this technique incorporating contralateral temporalis muscle at the tip of this flap and deeper vascularised pericranial layers within the pedicle to provide a more robust flap in selected cases. Study design/methods A retrospective review of two cases is presented with both patients having undergone multiple EEAs to resect skull base tumors with adjuvant radiotherapy, their postoperative courses complicated by recalcitrant CSF leaks resistant to multiple surgeries. Results Our patients had their persistent CSF fistulae repaired using infra‐temporal transposition of the TPFF modified to include some of the contralateral temporalis muscle with optimisation of a vascular pedicle: a temporo‐parietal temporalis myo‐fascial flap (TPTMFF). Both CSF leaks resolved without further complication. Conclusion In situations where local flap repair to reconstruct skull‐base defects following EEA may not be viable or has failed, a modified regional flap incorporating temporo‐parietal fascia with a preserved vascular pedicle along with attached temporalis muscle plug may provide a robust alternative option.

To identify factors associated with successful use of free tissue grafting versus vascularized reconstruction after resection of pituitary tumors. A retrospective chart review of 2 tertiary academic medical centers over 3.5 years was conducted. Variables assessed included age, sex, body mass index, pathology, extent of surgical exposure, cavernous sinus or suprasellar extension, intraoperative cerebrospinal fluid (CSF) leak, grade of leak, previous radiation, and previous surgery. Reconstructive techniques were divided into no reconstruction, free tissue grafts, and vascularized flaps. A total of 485 patients were included. Free grafts were used in 299/485 cases (61.6%) and were more commonly used with smaller approaches (P < 0.001). Larger exposure size and CSF leak grades 2 and 3 were associated with vascularized flap use (P < 0.001 and P = 0.012, respectively). Using multivariate regression, type of reconstruction could be predicted by increasing extent of approach, intraoperative CSF leak grade, and suprasellar extension (odds ratio [OR], 2.014, P < 0.001, 95% confidence interval [CI], 1.335–3.039; OR, 1.636, P = 0.025, 95% CI, 1.064–2.517; OR, 1.975, P < 0.001, 95% CI, 1.554–2.510, respectively). Postoperative CSF leak occurred in 9 of 173 patients (5.2%) with intraoperative leak and was not associated with any factors on analysis. We propose an algorithm whereby grade 1 CSF leaks in sellar and parasellar resections can be successfully reconstructed with a free graft. Vascularized flaps may be reserved for grade 2 or 3 intraoperative CSF leaks, extended approaches, or tumors with suprasellar extension. [ABSTRACT FROM AUTHOR]

Non-vascularized multilayer fascial closure technique (NMFCT) can be used instead of nasoseptal flap reconstruction for dural repair in endoscopic transnasal surgery (ETS); however, due to the lack of blood supply, its long-term durability and possible limitations need to be clarified. This was a retrospective study on patients who underwent ETS with intraoperative cerebrospinal fluid (CSF) leakage. We assessed the postoperative and delayed CSF leakage rates and the associated risk factors. Among 200 ETSs with intraoperative CSF leakage, 148 (74.0%) ETSs were performed for skull base pathologies other than pituitary neuroendocrine tumor. The mean follow-up period was 34.4 months. Esposito grade 3 leakage was confirmed in 148 (74.0%) cases. NMFCT was used either with (67 [33.5%]) or without (133 [66.5%]) lumbar drainage. There were 10 cases (5.0%) of postoperative CSF leakage that necessitated reoperation. In 4 other cases (2.0%), CSF leakage was suspected but lumbar drainage alone successfully restored the condition. Multivariate logistic regression analyses revealed that posterior skull base location (P < 0.01, odds ratio 11.5, 95% CI 1.99–2.17 × 102) and craniopharyngioma pathology (P = 0.03, odds ratio 9.4, 95% CI 1.25–1.92 × 102) were significantly associated with postoperative CSF leakage. No delayed leakage occurred during the observation period except for 2 patients who underwent multiple radiotherapies. NMFCT is a reasonable alternative with long-term durability, though vascularized flap may be a better choice for cases in which vascularity of the surrounding tissues is significantly impaired due to interventions including multiple radiotherapies. [ABSTRACT FROM AUTHOR]

Objective To evaluate the efficacy and weight of sellar floor repair techniques such as different dura suture, bone reconstruction, and pedicled nasoseptal flap (PNSF) on the skull base reconstruction of medium and high flow cerebrospinal fluid leakage during endonasal endoscopic pituitary adenoma surgery. Methods collected the data of Grade 2-3 cerebrospinal fluid leakage (Kelly grade) during endonasal endoscopic pituitary adenoma resection in our hospital from January 2015 to April 2021. Multiple reconstruction techniques such as dura suture, bone reconstruction and PNSF, and related factors such as age, sex, body mass index (BMI), diabetes, tumor size and diameter of diaphragmatic defect were recorded and introduced to multivariate regression to analyze the effects of the above factors on the duration of postoperative cerebrospinal fluid rhinorrhea and bed rest time, with a special focus on the weight priority of dura suture, bone reconstruction, and PNSF. Results A total of 281 patients were included, with the average age of (47±12.6) years. males accounting for 52.6%. There were 93 cases of PNSF, 268 cases of bone reconstruction, 109 cases of dura anchor suture, 50 cases of patch suture, and 122 cases without suture. The results of multivariate analysis indicated that the application of PNSF, bone reconstruction, and dura suture significantly reduced postoperative rhinorrhea time [reduced by 18.524, 35.876, and 16.983/19.791 (anchor suture/patch suture) hours, respectively; all P<0.001] and bed time [reduced by 16.797, 58.233, and 18.063/ 21.604 (anchor suture/patch suture) hours. respectively; all P<0.001], and there was no significant difference between anchor suture and patch suture. The weight of the standardized coefficient in reducing postoperative rhinorrhea time was dura suture> PNSF> bone reconstruction [Standard 8=0.211/0.207 (anchor suture/patch suture)>0.200 0.165]. The weight of reducing bed time was bone reconstruction >dura suture > PNSF [Standard B=0.239 0.206/0.210 (anchor suture/patch suture) >0.164]. After stabilizing the learning curve in 25-30 cases. the average time for bone reconstruction was (3.9±0.4) minutes. After stabilizing learning curve in 30-40 cases, the dura suture technique took an average of (3.7±0.3) minutes per stitch, (3.7±1.0) stitches per case, and (13.6± 2.7) minutes of total time consumption per case. Conclusion Dural anchoring and patching suture can both effectively shorten the duration of cerebrospinal fluid rhinorrhea and bed rest time. Bone reconstruction significantly improves the stability of reconstruction, especially in prompting patients' early disengagement of bed rest. Moreover, the learning curves of the above two methods are economical and reasonable, and their weight is close to or even exceeds that of PNSF. Therefore, they can be an effective supplement or even substitute for PNSF. [ABSTRACT FROM AUTHOR]

Background: 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). Objective: To present our experience and outcomes in utilizing FL in multiple ways to reconstruct a wide variety of complex skull base defects. Methods: Retrospective review was performed from May 2017 to February 2022 to identify 50 consecutive patients who underwent endoscopic skull base reconstruction using FL. Results: 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. Conclusion: 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. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study is to study the effect of in situ bone flap (ISBF) repositioning, a recently proposed rigid skull base reconstruction technique, on patients diagnosed with pituitary adenoma undergoing endoscopic endonasal approach (EEA). Method: A retrospective analysis was conducted on 188 patients with pituitary adenomas who underwent EEA from February 2018 to September 2022. Patients were divided into the ISBF group and non-ISBF group, according to whether ISBF was used during skull base reconstruction. Results: Of the 75 patients in the non-ISBF group, 6 had postoperative cerebrospinal fluid (CSF) leakage (8%), while only 1 of 113 patients in the ISBF group (0.8%) had postoperative CSF leakage, indicating that the incidence of postoperative CSF leakage in the ISBF group was significantly lower than that in the non-ISBF group (P = 0.033). In addition, we also found that the postoperative hospitalization days of patients in the ISBF group (5.34 ± 1.24) were significantly less than those in the non-ISBF group (6.83 ± 1.91, P = 0.015). Conclusion: ISBF repositioning is a safe, effective, and convenient rigid skull base reconstruction method for patients with pituitary adenoma treated by EEA, which can significantly reduce the rate of postoperative CSF leakage and shorten postoperative hospital stays. [ABSTRACT FROM AUTHOR]

BACKGROUND: Transnasal-sphenoidal neuroendoscopic surgery has become the most common surgical method for anterior skull base midline and lateral skull base location due to its characteristics of minimal invasion, full exposure and quick recovery. With the continuous expansion of surgical indications, the scope of skull base opening becomes larger and larger, then the incidence of postoperative cerebrospinal fluid leakage is correspondingly increasing. Severe cerebrospinal fluid leakage can cause fatal intracranial infection. Therefore, after neuroendoscopic resection of tumors, reliable skull base reconstruction is an essential condition for successful surgery. In this paper, the principles and methods of skull base reconstruction and biological properties of different materials used in skull base reconstruction are reviewed. OBJECTIVE: To expound the principles and methods of skull base reconstruction, summarize the research progress of different reconstruction materials and the role of different biological characteristics in skull base reconstruction. METHODS: Articles were retrieved on Wanfang and PubMed databases published from January 2012 to January 2022. The Chinese and English search terms were “skull base reconstruction, neuroendoscopy, skull base bone defect, transnasal-sphenoidal operative approach, multiple repair, pedicled mucosal flap, polyether-ether-ketone (PEEK), hydroxylapatite”. Finally, 60 articles were included for review. RESULTS AND CONCLUSION: (1) Even if the skull base defect is getting bigger and bigger, the purpose of skull base reconstruction is still to prevent cerebrospinal fluid leakage and avoid serious complications after transnasal-sphenoidal neuroendoscopic surgery. Multilayer repair is a universally accepted principle. (2) Bone-like materials such as polyether-ether-ketone and hydroxylapatite for bony support are less clinically used because of their high price and cumbersome preoperative preparation. Clinicians mostly rely on dural-like biomaterials and pedicled mucosal flaps to complete the repair. However, limited by the weak repair support and the blood supply of the mucosal flap, a small number of patients still have a certain risk of cerebrospinal fluid leakage. (3) Therefore, intraoperative dura-like and bone-like structure artificial biomaterials and pedicled mucosal flaps to repair skull base defects are in line with the restoration of the anatomical repair of the skull base, and are helpful for the regeneration of the dura and bone structures. The research and development of biomaterials integrating hydrophobic tissue + dural-like mater + bone-like structure + mucosa have great prospects for skull base reconstruction. [ABSTRACT FROM AUTHOR]

Objective To investigate the clinical characteristics and surgical treatment of huge dermoid cyst in ethmoid sinus-intracranial communication. Methods The clinical data of a patient with ethmoid sinus-intracranial huge dermoid cyst were analyzed retrospectively and the related literature were reviewed. Results A 58-year-old male patient was admitted with "left limb weakness for 4 years and progressive aggravation for 2 years". The patient was diagnosed as a huge tumor of ethmoid sinus-intracranial communication, and the possibility of teratoma was considered. Tumor resection was performed under general anesthesia through the right enlarged pteral approach, and the pathology showed dermoid cyst. There were no postoperative complications. After 1 year follow-up, there was no recurrence of tumor. Conclusions Large ethmoid sinus-intracranial dermoid cyst is relatively rare, so clinical attention should be paid to the differentiation from teratoma and epidermoid cyst, and surgical operation is the first choice for treatment. Intraoperative and postoperative measures should be taken to prevent aseptic meningitis. Due to tumor invasion of skull base, multidisciplinary cooperation should be paid attention to repair and reconstruction of skull base to prevent cerebrospinal fluid leakage. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. [ABSTRACT FROM AUTHOR]