Skull Base Reconstruction Research Articles

Comparison of Graft Materials in Multilayer Reconstruction with Nasoseptal Flap for High-Flow CSF Leak during Endoscopic Skull Base Surgery.

Cerebrospinal fluid (CSF) leak is a crucial complication after endoscopic skull base surgery. Therefore, multilayer reconstruction with grafts is as essential as a reconstruction with pedicled flaps. Although widely used, the multilayer technique with autologous fascia lata has drawbacks, such as additional wound and donor site complications. We compared acellular dermal graft and banked homologous fascia lata graft (alternative grafts) with autologous fascia lata graft for high-flow CSF leak repair. We retrospectively enrolled 193 subjects who underwent endoscopic skull base reconstruction with multilayer fascial grafts and nasoseptal flap for high-flow CSF leaks from November 2014 to February 2020 at a single institution. Acellular dermal matrix (ADM), banked homologous fascia lata, and autologous fascia lata were used in 48 (24.9%), 102 (52.8%), and 43 (22.3%) patients, respectively. Postoperative CSF leaks occurred in 23 (11.9%) patients and meningitis in 8 (4.1%). There was no significant difference in postoperative CSF leak (p = 0.36) and meningitis (p = 0.17) across the graft groups. Additionally, we could not find out contributing risk factors for postoperative CSF leak and meningitis. ADM and banked homologous fascia lata are non-inferior to autologous fascia lata for endoscopic skull base reconstruction in water-tight reconstruction or safety without additional donor site morbidities.

The Fate of Fat Graft in Extended Endoscopic Transtuberculum-Transplanum Approaches.

To analyze the long-term fate of autologous fat graft in skull base reconstruction after an extended endoscopic transtuberculum-transplanum approach. Data from 98 consecutive patients undergoing a transtuberculum-transplanum approach and skull base reconstruction using the 3F technique between June 2017 and January 2022 were retrospectively analyzed. Fat graft volume was measured on postoperative day 1 computed tomography scan and early (≤15 days), 3-month, and 1-year magnetic resonance imaging scans. Fat graft volumes and resorption rate were calculated in patients with a complete radiological follow-up and correlated to demographic, pathological, and surgical features. Fat volumes and resorption rate were calculated in 55 patients. Mean volume of fat on postoperative day 1 computed tomography scan was 3.58 ± 1.89 cm3 and on early, 3-month, and 1-year postoperative magnetic resonance imaging scans was 2.45 ± 1.57 cm3, 1.40 ± 0.76 cm3, and 0.92 ± 0.56 cm3, respectively. Resorption rate was 44% after 3 months and 67% after 1 year. Resorption rate did not significantly correlate with demographic, pathological, and surgical features. Cerebrospinal fluid leak requiring redo surgery occurred in 1 patient (1/98, 1.2%). There were 6 cases of visual worsening (6/98, 6.1%); no cases correlated to fat overpacking. No delayed complications at the donor site or at the grafting site were noted. Autologous fat graft in skull base reconstruction is observed to shrink significantly over time, reaching 67% in 1 year. Its use is associated with excellent outcomes, making it a favored material for skull base reconstruction.

A New Technique for the Endoscopic Reconstruction of Skull Base Defects Using Multiple-balloon Catheters.

Cerebrospinal fluid (CSF) leakage is a major complication following endoscopic endonasal skull base surgery. Various skull base reconstruction methods are available, and the use of a vascularized nasoseptal flap (NSF) in skull base reconstruction has greatly contributed to a decrease in the CSF leak rate. A balloon catheter such as a sinus balloon or a Foley catheter is often used to support an NSF; however, in cases wherein nasal and/or paranasal structures supporting the balloon are lacking following the surgery, the NSF is not properly fixed and postoperative CSF leak may occur. Here we introduce a new technique of using multiple-balloon catheters to fix an NSF in such cases and provide the results of our analysis of the new technique's efficacy. Eight patients who underwent endonasal endoscopic surgery for the following cases were included: olfactory neuroblastoma (n = 6), recurrent craniofacial meningioma (n = 1), and recurrent chordoma (n = 1). After tumor resection, multilayered reconstruction with vascularized NSF was performed. Given that the Foley catheter was not stable to fix the flap in each case, we used an additional nasal catheter to support the Foley catheter. No complications such as postoperative CSF leak and necrosis of the vascularized flap were observed. These results suggest that the multiple-balloon catheter technique is a useful method for fixing the NSF to the skull base even when nasal cavity structures are missing due to surgical removal.

Superiorly Based Middle Turbinate Flap for Repair of Cerebrospinal Fluid Rhinorrhea: A Cadaveric Feasibility Study and Case Series.

Objectives Cerebrospinal fluid (CSF) leaks of the anterior cranial base are frequently repaired with endonasal, multilayered reconstructions. Vascularized tissue flaps are superior to free mucosal grafts and biomaterials in many cases. Limitations of previously described flaps include reach, rotation, pedicle availability, and postoperative sinonasal morbidity. The objective of this study is to describe the superiorly based middle turbinate flap, a novel vascularized mucosal reconstruction option, and to present a case series demonstrating flap utility. Design Cadaveric feasibility study with technical description and illustrative case series. Setting Tertiary medical center. Participants Three silicone-injected cadaveric specimens (6 sides); 7 patients with CSF rhinorrhea from bony dehiscence of the anterior cranial fossa repaired with a superiorly based middle turbinate flap. Outcome Measures Cadaveric feasibility, in vivo repair outcomes, sinonasal symptoms, and postoperative healing. Results Cadaveric dissection demonstrated a consistent vascular plexus arising from the anterior and posterior ethmoid arteries, originating at the superior attachment of the middle turbinate and traveling inferiorly to supply the mucosa of the middle turbinate. Mean surface area of the flap was 776.67 ± 114.60 mm 2 . The clinical series of 7 patients involved leaks around the cribriform plate and fovea ethmoidalis. There were no instances of repair failure. All cases showed rapid and complete remucosalization without significant sinonasal morbidity. Conclusion The superiorly based middle turbinate flap is a reliable, versatile, and effective option for a vascularized mucosal flap onlay that can be used in anterior skull base reconstruction. This flap is particularly useful in the repair of defects involving the cribriform plate and fovea ethmoidalis.

Extended endoscopic endonasal approach for resecting anterior intrinsic third ventricular craniopharyngioma.

BackgroundThe surgical treatment of the extended endoscopic endonasal approach (EEEA) is a safe and effective treatment for suprasellar craniopharyngiomas. However, due to damage to the hypothalamus and third ventricle floor (TVF), EEEA is generally regarded as unsuitable in treating intrinsic third ventricle craniopharyngioma (ITVC) that is entirely within the third ventricle. Until now, there have been only a small number of reports using EEEA to treat TVC via a supra-infrachiasmatic approach. Given that the translamina terminalis (TLT) corridor was used in the transcranial subfrontal approach, EEEA via a suprachiasmatic approach may be feasible and practical to treat ITVC. In the current study, we accumulated experience applying the suprachiasmatic translamina terminalis (STLT) corridor for anterior treatment of ITVC.MethodsFrom March 2016 to December 2020, 14 patients with ITVC in our center were analyzed retrospectively. All patients underwent surgery by EEEA via an STLT corridor. The multilayer reconstruction technique was adopted to achieve skull base reconstruction. Data concerning the patient’s tumor resection, vision, hypophyseal hormone, and complications were collected.ResultsGross-total resection was achieved in 13 (92.8%) of14 patients, with achievement of near-total (90%) resection in the remaining 1 patient. Nine cases (64.3%) were papillary craniopharyngiomas, and the other 5 cases were adamantinomatous subtypes. Postoperatively, 3 patients with pituitary insufficiency received hormone replacement therapy. No permanent diabetes insipidus or hypothalamic obesity was found. All pairs showed significant improvement or stability in vision except 1 patient who encountered visual deterioration. No other neurological deficit occurred postoperatively. Observation results for the exudation of nasal tissue and the length of hospitalization were satisfactory. After a mean follow-up period of 26.2 months, tumor recurrence was not observed.ConclusionTLT is a minimally invasive corridor used in EEEA for treating anterior ITVC without increasing risks of visual and hormonal deficits. The multilayered reconstruction technique we used is a safe and effective method for achieving watertight closure and avoiding cerebrospinal fluid leaks and infection. The endonasal approach via STLT provides a new, safe and efficacious operative strategy that should be considered a surgical alternative in treating ITVC.

Exploration of the causes of cerebrospinal fluid leakage after endoscopic endonasal surgery for sellar and suprasellar lesions and analysis of risk factors.

ObjectivePostoperative cerebrospinal fluid (CSF) leakage following endoscopic endonasal surgery (EES) is a frequent complication. This study aims to identify potential risk factors of postoperative CSF leakage.MethodsA retrospective review of 360 patients who underwent EES was included. The associations between postoperative CSF leakage and patient demographics, medical history, tumor characteristics, and intraoperative repair techniques were analyzed; the diagnosis and repair of postoperative CSF leakage were also introduced.ResultsPostoperative CSF leakage occurred in 14 patients (3.9%), 2 of them cured by lumbar cistern drainage, 12 underwent endoscopic repair. Among these 12 cases, 3 were repaired twice, and the rest were cured the first time. During the repair surgery, insufficient embedded fat was detected in one case detected, seven with breached inner artificial dura, three had vascularized pedicle nasoseptal flap (VP-NSF) displacement, two with VP-NSF perforation, two with VP-NSF inactivation, and one with imperfect adherence to VP-NSF to the skull base. Eight cases had intracranial infections. Excluding one case who died of severe intracranial infection, the rest were cured and discharged without obvious sequelae. Multivariate analysis revealed that the suprasellar lesion, subarachnoid invasion, and intraoperative grade 3 flow CSF leakage were the risk factors of CSF leakage after operation, while the bone flap was a protective factor.ConclusionBone flap combined with VP-NSF and iodoform gauze for skull base reconstruction is recommended in high-risk patients, while postoperative lumbar cistern drain remains dispensable.

Risk factors and management associated with postoperative cerebrospinal fluid leak after endoscopic endonasal surgery for pituitary adenoma.

ObjectiveTo determine risk factors and management for the development of a postoperative cerebrospinal fluid (CSF) leak after an endoscopic endonasal surgery (EES) for pituitary adenomas.MethodsThe clinical data of 400 patients who underwent EES for resection of pituitary adenomas from December 2018 to November 2019 in the Department of Neurosurgery of Beijing Tiantan Hospital were retrospectively reviewed. Age, gender, body mass index (BMI), tumor size, Knosp grade, suprasellar extension grade, sellar floor erosion grade, repeated transsphenoidal surgery, intraoperative CSF leak, use of pedicled nasoseptal flap and lumbar drain were collected and analyzed.ResultsPostoperative CSF leak occurred in 14 of 400 patients (3.5%). Age, gender, BMI, tumor size, Knosp grade and repeated transsphenoidal surgery were not risk factors for CSF leak. Suprasellar extension grade (≥B 6.0% vs. <B 1.4%; p = 0.024), sellar floor erosion grade (≥III 5.7% vs. <III 0.6%; p = 0.020) and intraoperative CSF leak (Yes 7.5% vs. No 2.0%; p = 0.009) were factors associated with an increased postoperative CSF leak rate.ConclusionsHigher suprasellar extension grade, higher sellar floor erosion grade and intraoperative CSF leak were risk factors for postoperative CSF leak after endoscopic treatment of pituitary adenoma. Strict skull base reconstruction including use of a pedicled nasoseptal flap and perioperative lumbar drainage may avoid postoperative CSF leak.

Prevention of and Countermeasures for Surgical Site Infection in the Field of Skull Base Surgery

In neurosurgery, perioperative surgical site infection(SSI)is associated with complicated postoperative management, prolonged hospital stay, and patient stress. In this article, we review SSI in the field of skull base surgery, including endoscopic endonasal surgery, and discuss ways to prevent SSI. In a craniotomy, in which the frontal sinus is revealed, prevention of cerebrospinal fluid(CSF)leakage by reliable repair of the dura and frontal sinus reduces SSI. In addition, prevention of postoperative CSF leakage by reliable skull base reconstruction in endoscopic endonasal surgery contributes to the prevention of SSI. Prophylactic antibiotics are often reported to be useful, and cephalosporin or sulbactam/ampicillin intravenous injections are generally used. There are insufficient data to recommend lumbar drainage for the management of SSI and postoperative CSF leak. Skull base surgery is often a clean-contaminated surgery, and serious complications can be prevented by proper understanding and performance of the appropriate method as required. However, no studies with a high level of evidence on SSI in the field of skull base surgery exist. New large randomized controlled trials are expected to evaluate the efficacy of prophylactic antibiotics in skull base surgery.

Advances in Pituitary Surgery.

Pituitary surgery has advanced considerably in recent years with the exploration and development of various endoscopic approaches and techniques. Different endoscopic skull base approaches are being applied to access sellar tumors in different locations. Moreover, extracapsular dissection and cavernous sinus exploration have enabled gross total resection of sellar tumors where it could not have been achieved in the past. Techniques for skull base reconstruction have also progressed, allowing surgeons to remove larger and more complicated tumors than before. This review article discusses different endoscopic skull base approaches, surgical techniques for removing pituitary adenomas, and reconstruction methods for repairing postoperative low-flow and high-flow cerebrospinal fluid leakage.

Application of dural suturing in the endoscopic endonasal approach to the sellar region.

The endoscopic endonasal approach (EEA) is widely used in the treatment of cranial base tumors. Skull base reconstruction is a crucial part of EEA, which has a great impact on patients' prognosis. In this study, we report our experience with sellar dural suturing in cranial base reconstruction and retrospectively analyze its effect. The clinical data of 134 patients who suffered intraoperative CSF leakage and underwent EEA surgery in the Department of Neurosurgery of the First Affiliated Hospital of Nanjing Medical University from October 2018 to November 2020 were retrospectively collected and analyzed. According to whether sellar dural suturing was performed during the operation, they were divided into a suture group (55 cases) and a control group (79 cases). The results showed that dural suturing of the sellar floor effectively reduced the postoperative hospitalization duration (p = 0.026) and the use rates of lumbar drainage (p = 0.047), autologous fat transplantation (p = 0.038), and pedicled nasoseptal flaps (p = 0.026). Sellar dural suturing under endoscopy is a promising and effective method for cranial base reconstruction in EEA surgery and is worthy of clinical application.

Reconstruction Strategy After Endoscopic Skull-Base Surgery

Endoscopic skull-base surgery (ESBS) is a rapidly growing surgical area that involves collaboration of otolaryngology-head and neck surgeons and neurosurgeons. Various tumor pathologies and extents have been successfully treated with ESBS, and diverse reconstruction methods have been adopted since its introduction. The optimal reconstructive strategy should be based on heterogeneous surgical situations and tumor extent. Nevertheless, there are few current guidelines for selecting reconstructive methods. Therefore, we review diverse options for endoscopic skull-base reconstruction.

Effects of cruciate embedding fascia-bone flap technique on grade II–III cerebral spinal fluid leak in endoscopic endonasal surgery

BackgroundCerebral spinal fluid (CSF) leak remains an important issue in endoscopic endonasal surgery (EES). A standard protocol for skull base closure has not yet been established, and the application of rigid buttress has not been given sufficient attention. To emphasize the functions of support and fixation from rigid buttress in reconstruction, we introduced the cruciate embedding fascia-bone flap (CEFB) technique using autologous bone graft to buttress the fascia lata attachment to the partially sutured skull base dural defect and evaluated its efficacy in a consecutive case series of grade II–III CSF leaks in EES.MethodsData from consecutive patients diagnosed with sellar region lesions with grade II–III CSF leaks during EES were collected from May 2015 to May 2020. Skull base reconstructions were performed with the CEFB or the conventional pedicle vascularized nasoseptal flap (PNSF). Related clinical data were analysed. The combined use of the CEFB and PNSF was applied to an additional supplemental case series of patients with grade III leak and multiple high-risk factors.ResultsThere were 110 and 65 patients included in the CEFB and PNSF groups, respectively. The CEFB demonstrated similar effects on the incidence of postoperative CSF leak (2.7%), intracranial infection (4.5%), and lumbar drainage (LD) placement (5.5%) as PNSF (3.1%, 3.1%, and 6.2%), but with less epistaxis (CEFB: 0%, PNSF: 6.2%) and nasal discomforts (CEFB: 0%, PNSF: 7.7%). The LD duration (CEFB: 6.67 ± 2.16 days, PNSF: 10.50 ± 2.38 days), bed-stay time (CEFB: 5.74 ± 1.58 days, PNSF: 8.83 ± 3.78 days) and hospitalization time (CEFB: 10.49 ± 5.51 days, PNSF: 13.58 ± 5.50 days) were shortened in the CEFB group. The combined use of CEFB and PNSF resulted in 0 postoperative CSF leaks in the supplemental case series of 23 highly susceptible patients.ConclusionThis study suggested that the new CEFB technique has the potential to prevent postoperative CSF leak in EES. The results indicated that it can be used effectively without PNSF in suitable cases or applied in addition to a PNSF with high compatibility when necessary. Its effectiveness should be further verified with a larger cohort and better design in the next step.Trial Registration Current Controlled Trials ChiCTR2100044764 (Chinese Clinical Trial Registry); date of registration: 27 March 2020. Retrospectively registered

Septal rhinopharyngeal flap: a novel technique for skull base reconstruction after endoscopic endonasal clivectomies.

Endoscopic endonasal reconstruction techniques have improved CSF leak rates that were initially reported after surgery for cranial base and intradural lesions. However, wide surgical defects still pose a problem, especially if located in the clival region. The authors propose and describe a novel reconstruction technique they call a septal rhinopharyngeal flap (SRF) specifically designed to address this issue. The SRF is formed by three components of mucosa: 1) septal, 2) rhinopharyngeal roof, and 3) rhinopharyngeal posterior wall components, which allows for the coverage of the tuberculum/sellar region, midclivus, and lower clivus, respectively. A step-by-step procedure is described and its results analyzed in cases in which it has been used. The SRF was performed in 8 patients, which included diagnoses of 4 chordomas, 2 petroclival meningiomas, 1 invasive pituitary adenoma, and 1 chondrosarcoma. The size of the flap was considered optimal in all patients (100%). Postoperative MRI revealed contrast enhancement covering the entire surface of the flap. No CSF leaks were encountered after at least 1 postoperative year. The SRF is a novel vascularized reconstruction technique specifically indicated for wide endosanasal clivectomies focused on the middle clivus with caudal extension into the lower clivus and craniocervical junction, as well as rostral extensions into the tubercular or planum sphenoidale. This new reconstruction technique could be added to the skull base reconstruction armamentarium as a safe and optimal option.

Application of the subdural evacuating port system for the drainage of postoperative tension pneumocephalus: A technical note.

Background: Tension pneumocephalus is a neurosurgical emergency requiring prompt intervention. A variety of either temporizing or definitive methods was previously described as part of its management. Here, we report on an off-label use of a bed-side device and the subdural evacuating port system (SEPS)™ for the treatment of tension pneumocephalus.Methods: The SEPS™ (Medtronic Dublin, Ireland) is a minimally invasive tool that is indicated for the removal of chronic or subacute subdural hematomas and at the patient’s bedside. We describe the use of this system to evacuate tension pneumocephalus.Results: A 44-year-old patient operated in our institution was presented with sudden obtundation 4 days post resection of esthesioneuroblastoma. Imaging confirmed a significant tension pneumocephalus. Immediate bedside decompression using a SEPS bolt placed frontally was performed, achieving rapid evacuation and patient regained consciousness. A definitive skull base reconstruction was done at the operating room at a later stage.Conclusion: The SEPS™, well-known for evacuation of CSDH, can be potentially used as a bed-side tool to effectively treat mass effect created by tension pneumocephalus. As a readily-available and commercially used device, it can provide a simple and standard toolkit suitable for an emergent temporizing procedure.

Clinical Impact of Hydroxyapatite on the Outcome of Skull Base Reconstruction for Intraoperative High-Flow CSF Leak: A Propensity Score Matching Analysis.

BackgroundDespite recent advances in skull base reconstructive techniques, including the multilayer technique during the last decade, complete reconstruction of grade 3 intraoperative high-flow cerebrospinal fluid (CSF) leak remains challenging. This study was designed to investigate the role of injectable hydroxyapatite (HXA) used in the multilayer technique on the clinical outcome of skull base reconstruction for intraoperative high-flow CSF leak.Materials and MethodsThis study enrolled 187 patients who experienced intraoperative high-flow CSF leak after endoscopic endonasal surgery for anterior skull base or suprasellar pathologies between January 2014 and July 2021. All skull base defects were reconstructed using the conventional multilayer technique including a vascularized naso-septal flap (NSF, n = 141) and the combined use of HXA with the conventional multilayer technique (HXA group, n = 46). We retrospectively evaluated the efficacy of the HXA group by 1:2 propensity score matching analysis.ResultsOverall, 17 of 187 patients (9.1%) showed postoperative CSF leaks, resulting in second reconstruction surgery. There were no statistical differences in patient age, sex, body mass index, tumor location, tumor type, and degree of resection, except for the follow-up period between the two groups. The HXA group showed a significantly lower incidence of postoperative CSF leak than the control group (0% vs. 12.1%, p < 0.05). Postoperative lumbar drain (LD) was performed in 8.7% of the HXA group compared to 46.1% of the control group (p < 0.01). CSF leak-related infection rates showed a decreasing tendency in the HXA group compared to the control group (0 vs. 7.1%, p = 0.06). A total of 46 patients in the HXA group were well matched with the control group (92 patients) at a 1:2 ratio. In the propensity score-matched control group, there were higher rates of postoperative CSF leaks than in the HXA group.ConclusionThe use of HXA combined with the conventional multilayer technique completely reduced postoperative CSF leaks in this study. This technique resulted in reduced CSF leakage, even without postoperative LD, and decreased infection rates. Further randomized comparative studies are required to confirm our findings.

Quick and simple dural threading technique for transsphenoidal surgery - dural tenting, haemostasis and skull base reconstruction.

Dural suturing is one of the most robust reconstruction methods in transsphenoidal surgery; however, the technique is considered difficult, primarily due to the restricted range of needle movement. We performed dural threading during transsphenoidal surgery by holding the needle with forceps as a hook and moving the needle in a distal to proximal direction. Our dural suturing technique is simple and quick. It can be used not only for dural closure but also for other procedures, such as controlling haemostasis from the intercavernous sinus and dural tenting.

Basic Concept of Skull Base Reconstructive Surgery

In most cases of anterior cranial fossa defects, the cranial cavity and the nasal cavity are connected, and it is necessary to reconstruct the skull base in a narrow sense to separate both cavities. If the surgical purpose is only separation, reconstruction with a pedicled local flap is often possible. As other surgical purposes such as the reconstruction of surrounding tissues are added, the transplanted tissue volume becomes insufficient, and free tissue transfer is required. In the case of a defect in the middle cranial fossa, the cranial cavity is not always connected with the nasal cavity because it is far from the nasal cavity and oral cavity. In this case, it is skull base reconstruction in a broad sense whose purpose is other than separation. There are many factors such as facial soft tissue augmentation and facial nerve reconstruction as the surgical purpose, and the more the purposes, the more likely it is that free tissue transfer will be required. In patients with anterior and middle cranial fossa defects, both cavities are connected and the resected tissue volume is large, so free tissue transfer is selected in most cases, except for a few benign diseases.

Points and Pitfalls of Deep Dural Suture

Infection, especially meningitis, has always been a problem in transsphenoidal surgery(TSS)for tumors of the sella turcica, and it would not be an exaggeration to say that the history of improvements in transsphenoidal sinus surgery is the history of the battle against meningitis. Furthermore, around 1990, endoscopy was introduced to TSS, and TSS has been applied to median skull base tumors extending beyond the sella turcica and is being performed as extended TSS. As a result, TSS has also been performed for surgeries with large dural defects, and the deep dural suture method(DDSM)has been advocated mainly in Japan while TSS has been improved to prevent cerebrospinal fluid leakage. In this article, we will describe the transition and current method of skull base reconstruction in TSS and DDSM in detail, citing past literature and using videos of the methods used at our institution.

Pedicled frontal periosteal rescue flap via eyebrow incision for skull base reconstruction (SevEN-002)

PurposeCerebrospinal fluid (CSF) leakage is one of the major complications after endoscopic endonasal surgery. The reconstructive nasoseptal flap is widely used to repair CSF leakage. However, it could not be utilized in all cases; thus, there was a need for an alternative. We developed a pericranial rescue flap that could cover both sellar and anterior skull base defects via the endonasal approach. A modified surgical technique that did not violate the frontal sinus and cause cosmetic problems was designed using the pericranial rescue flap.MethodsWe performed 12 cadaveric dissections to investigate the applicability of the lateral pericranial rescue flap. An incision was made, extending from the middle to the lateral part of the eyebrow. The pericranium layer was dissected away from the galea layer, from the supraorbital region towards the frontoparietal region. With endoscopic assistance, the periosteal flap was raised, the flap base was the pericranium layer at the eyebrow incision. After a burr-hole was made in the supraorbital bone, the pericranial flap was inserted via the intradural or extradural pathway.ResultsThe mean size of the pericranial flap was 11.5 cm × 3.2 cm. It was large enough to cross the midline and cover the dural defects of the anterior skull base, including the sellar region.ConclusionWe demonstrated a modified endoscopic technique to repair the anterior skull base defects. This minimally invasive pericranial flap may resolve neurosurgical complications, such as CSF leakage.

Minimally invasive pericranial flap harvest through a supraorbital eyebrow craniotomy: Technical note in salvage skull base reconstruction

Background and importanceThe supraorbital eyebrow craniotomy is a minimally invasive approach that provides access to pathologies of the anterior and middle cranial fossae. Vascularized flaps are preferred when considering reconstructive options, however, small incisions may not provide adequate access to vascularized tissue. We present two cases demonstrating a modified technique for harvesting pericranium through an eyebrow supraorbital craniotomy for reconstruction of large skull base defects. Clinical presentationThe first case is of a 62-year-old woman with an invasive esthesioneuroblastoma. Multiple resections and reconstructions, including a large frontal craniectomy and titanium mesh cranioplasty, resulted in refractory tension pneumocephalus. A supraorbital craniotomy was performed with endoscope-assisted harvesting of a pericranial flap through a coronal plane stab incision for definitive repair. The second case is a 44-year-old woman with a high-grade neuroendocrine tumor transgressing the anterior cranial fossa. Resection was achieved via combined supraorbital eyebrow craniotomy and endoscopic endonasal approach. A multilayered reconstruction including a pericranial flap from above and a nasoseptal flap from below was used to reconstruct the defect. The pericranial flap was again harvested with endoscope assistance through a coronal plane stab incision. Both cases had excellent outcomes with no post-operative cerebrospinal fluid leak. ConclusionRepair of large anterior cranial fossa defects with a vascularized pericranial flap can be performed through a supraorbital eyebrow craniotomy. Utilizing small, strategically placed transverse (coronal plane) incisions behind the hairline allows for the endoscope-assisted harvesting of a highly customized flap. This modified technique increases the flexibility of the minimally invasive supraorbital craniotomy.