Anterior skull base reconstruction using an anterolateral thigh free flap

Background: Galeal or temporalis muscle flaps have been traditionally used to reconstruct skull base defects after tumor removal. Unfortunately, these flaps do not provide sufficient vascularized tissue for a dural seal in extensive defects. This study describes the successful coverage of large skull base defects using anterolateral thigh (ALT) free flaps.Methods: This retrospective study included five patients who underwent skull base surgery between June 2018 and June 2021. Reconstruction was performed using an ALT free flap to cover defects that included the intracranial space and extended to the frontal sinus and cribriform plate.Results: There were no major complications, such as ascending infections or cerebrospinal leakage. Postoperative magnetic resonance imaging showed that the flaps were well-maintained in all patients.Conclusion: Successful reconstruction was performed using ALT free flaps for large anterior skull base defects. In conclusion, the ALT free flap is an effective option for preventing communication between the nasal cavity and the intracranial space.

Anterior Skull Base Tumors and Surgery

Anterior skull base surgery requires intimate knowledge of a highly complex anatomic region containing critical neurovascular structures. A wide array of pathologies can occur along the anterior cranial base, including meningiomas, esthesioneuroblastomas, pituitary adenomas, craniopharyngiomas, chondrosarcomas, and chordomas. Advancements in endoscopic sinus surgery have allowed many of these tumors to be effectively treated via an endoscopic endonasal technique. This approach obviates the need for large incisions causing cosmetic deformity, improves magnification of the surgical field, and offers a direct path to lesions thus avoiding retraction of structures such as the brain and nerves. Surgeons must understand the limitations of endoscopic techniques and consider open or combined open and endoscopic approaches when appropriate. Reconstructive anterior skull base techniques vary depending on the size and location of defects, along with factors such as intracranial pressure and patient co-morbidities. Large skull base defects require multilayer reconstruction that include a watertight primary dural repair with either synthetic or autologous tissue, followed by local vascularized tissue flaps. This review contains 8 figures, 2 videos, 4 tables and 33 references Key words: Anterior skull base, meningioma, esthesioneuroblastoma, chordoma, pituitary, CSF leak, nasosptal flap, dural repair, expanded endonasal approaches, endoscopic surgery

Reconstruction of Complex Lateral Skull Base Defects After Oral Cancer Resection With Individualized Anterolateral Thigh Flap

ObjectivesComplex lateral skull base defects resulting from advanced or recurrent oral cancer resection are continuously challenging reconstructive surgeons. This study aimed to use reconstructive methods for lateral skull base defects, explore their feasibility, and evaluate the efficacy of defect reconstruction using anterolateral thigh (ALT) flaps.Patients and MethodsWe performed a retrospective case series of 37 patients who underwent lateral skull base defect reconstruction using the ALT/anteromedial thigh (AMT) flap between March 2016 and May 2021 at the Second Xiangya Hospital. The design and harvest of the flaps, methods for defect reconstruction, and reconstructive efficacy are described.ResultsOf the 37 patients, 3 were women and 34 were men, with a mean age of 51.7 years. Among the defects, 26 were through-and-through defects and were reconstructed using ALT chimeric flaps, double ALT flaps, folded ALT flap, combined ALT chimeric flaps and AMT flaps, or combined ALT chimeric flaps and pectoralis major flaps; the large lateral skull base dead spaces were filled with muscle tissues or fatty tissues. Postoperatively, 38 of the 39 ALT/AMT flaps survived completely, and the remaining flap experienced partial necrosis. Venous compromise occurred in one patient who was salvaged after operative exploration. Oral and maxillofacial wound infections occurred in two patients, salivary fistula in three patients, and thigh wound effusion in three patients. The wounds healed gradually in all patients after repeated dressing changes. Thirty-three patients were followed up for approximately 3–60 months; their oral functions and appearance were acceptable, and thigh motor dysfunction was not observed.ConclusionsWith the convenient flap design and muscle flap harvest, large and individualized tissue supply, feasible combination with other flaps, effective reduction or avoidance of wound complications, and acceptable donor site morbidity, the ALT flap is an appropriate choice for complex lateral skull base defect reconstruction.

RECONSTRUCTION OF LARGE ANTERIOR SKULL BASE DEFECTS AFTER RESECTION OF SINONASAL TUMORS WITH INTRACRANIAL EXTENSION BY USING PEDICLED DOUBLE FLAP TECHNIQUES

Background: Surgical resection of a large anterior skull base (ASB) tumor and sinonasal maglinancies with intracranial extension will result a large skull base defect. Reconstruction of large ASB defects by using traditional techniques may result in high risk of postoperative CSF leakage, meningitis and increase mortality rate. The use of pedicled double flap technique to reconstruct the anterior skull base defect may decrease the complications. In this study, we examine the clinical outcomes of patients who underwent this double flap reconstruction technique after the resection of sinonasal malignancies with significant intracranial extension at Cho Ray hospital, Vietnam. Methods: Case series study was conducted at Cho Ray hospital from 09/2010 to 09/2020. All patients with large sinonasal malignancies with intracranial invasion underwent combined transbasal - EEA approach. Reconstruction of large skull base defect ( > 2 cm ) was followed by using the pedicled double flap technique. Results: There were 75 patients who underwent the modified multi-layer with double flap reconstruction technique after the resection of ASB tumor from 09/2010 to 09/2020. The skull base defects were commonly seen at the horizontal plate of the ethmoid and the roof of the ethmoid ( 98.6%). The large skull base defects ( > 2cm) accounted for 81.3%. The risk of postoperative CSF leakage after double flap repair was very low. In this study, we had 1 patient with postoperative CSF leakage and 1 patient had postoperative meningitis. Conclusion: The use of two vascularize pedicled flap may decrease the incidence of postoperative cerebral spinal fluid (CSF) leakage and meningitis. This technique is an effective method for the reconstruction of the ASB with large defect.

Transinfratemporal Fossa Transposition of the Temporalis Muscle Flap for Skull Base Reconstruction after Endoscopic Expanded Nasopharyngectomy: Anatomical Study and Clinical Application

Background Temporalis muscle flap (TMF) is widely used in traditional skull base surgery, but its application in endoscopic skull base surgery remains rarely reported. We aimed to investigate the surgical anatomy and clinical application of TMF for reconstruction of skull base defects after expanded endoscopic nasopharyngectomy. Materials and Methods Nine fresh cadaver heads (18 sides) were used for endoscopic dissection at the University of Pittsburgh School of Medicine in the United States. TMF was harvested using a traditional open approach and then transposed into the maxillary sinus and nasal cavity through the infratemporal fossa using an endoscopic transnasal transmaxillary approach. TMF length was then measured. Moreover, TMF was used for the reconstruction of skull base defects of six patients with recurrent nasopharyngeal carcinoma after expanded endoscopic nasopharyngectomy. Results The length of TMF harvested from the temporal line to the tip of the coronoid process of the mandible was 11.8 ± 0.9 cm. The widest part of the flap was 9.0 ± 0.4 cm. When TMF was dislocated from the coronoid process of the mandible, approximately another 2 cm of reach could be obtained. When the superficial layer of the temporalis muscle was split from the deep layer, the pedicle length could be extended 1.9 ± 0.2 cm. TMF could cover skull base defects in the anterior skull base, sellar, and clivus regions. Conclusion TMF can be used to reconstruct skull base defects after endoscopic expanded nasopharyngectomy and can effectively prevent the occurrence of serious complications in patients with recurrent nasopharyngeal carcinoma.