Efficiency and Safety of Autologous Fat Grafts in Reconstructing Skull Base Defects After Resection of Skull Base Meningiomas

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

OBJECTIVE

To analyze the long-term fate of autologous fat graft in skull base reconstruction after an extended endoscopic transtuberculum-transplanum approach.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Clinial Features, Individualized Treatment and Long-Term Surgical Outcomes of Skull Base Meningiomas With Extracranial Extensions

Object: Skull base meningiomas with extracranial extensions are rarely described. This study describes the clinical features, surgical management and clinical outcomes of these rare tumors and investigates risk factors associated with progression-free survival (PFS). Methods: The clinical data of 34 consecutive patients who underwent surgery for skull base meningiomas with extracranial extensions from 2007 to 2018 were retrospectively collected and analyzed. Results: The mean patient age was 47.9 ± 13.9 years; 50.0% were male. The most common symptoms on admission were ophthalmic. All patients underwent a multidisciplinary consultation before surgery, and received individualized surgical management. The gross total resection (GTR) rate was 55.9% (19/34). Twelve patients received post-operative adjuvant radiotherapy (RT). Twelve patients experienced tumor recurrence during the follow-up period. The median PFS duration was 54 months. The mean overall survival (OS) duration was 111 months. By univariate analysis, a higher histological grade (WHO grade II and III), Ki-67 LI ≥ 5 and the extent of resection (EOR) were significantly associated with tumor recurrence. Multivariate analysis revealed Ki-67 LI ≥ 5, the EOR and adjuvant RT as prognostic factor of PFS. Conclusions: These relatively rare meningiomas are difficult to resect and have a poor prognosis; they are more common in males and have a higher histological grade than intracranial meningiomas. Multidisciplinary collaboration and individualized surgical strategies are crucial for surgically managing these complex tumors. Total removal of the tumor remains challenging. Subtotal resection (STR) or partial resection (PR) followed by RT is a reasonable strategy when radical resection is infeasible. Adjuvant RT should be recommended especially for tumors with histopathological risk factors (Ki-67 LI ≥ 5 or high histological grade).

Second Free Flap Surgery for Skull Base Tumors: Case Report and Literature Review

Tumors of the skull base, such as meningiomas, tend to recur. With progress in free vascularized flap surgery, an increasing number of studies are investigating skull base reconstruction with free flaps after tumor removal. In this report, we discuss the results of second free flap surgery after skull base reconstructive surgery. We retrospectively analyzed data from patients treated at our center during the period from 2013 through 2017. All four patients identified had skull base anaplastic meningioma and had undergone radiotherapy. In all cases, the flap and donor blood vessel were sourced from sites that differed from those used in the previous surgeries. No complications developed, such as cerebrospinal fluid leakage, meningitis, wound infection, wound hemorrhage, or flap necrosis. Because the first flap was found to be unviable, it was difficult to preserve and was removed. Essential points in preventing complications are anchoring at the appropriate site, pinprick testing of the created flap, and use of multilayered countermeasures to prevent cerebrospinal fluid leakage.

Update on anterior skull base reconstruction

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Skull Base Dural Repair Using Autologous Fat as a Dural Substitute: An Efficient Technique

BACKGROUND

Dural repair during skull base approaches remains challenging, especially in the presence of significant defects. The autologous fat has become an alternative to various substitute materials being used previously. We report here our experience and technique for the repair of notable skull base dural defects using autologous fat as a dural substitute.

METHODS

Over a period of 5 years, 71 consecutive patients operated on for skull base pathologies with an important intraoperative dural defect repaired using autologous fat tissue as replacement material were reviewed. The graft, withdrawn from the abdomen or thigh, was flattened and applied to the defect. The clinical findings and outcomes were assessed.

RESULTS

Main pathologies included schwannomas (45%) and meningiomas (35.21%), with no side predilection. Surgical approaches such as transcondylar fossa, suboccipital, and frontotemporal approaches were used. Dural defects were mainly located in the posterior (73.2%) and middle cranial fossae (25.4%). No harvesting site-related complication occurred. In 7 cases, transitory subcutaneous fluid collection spontaneously resorbing after 8 days to 2 months was observed. No external cerebrospinal fluid leakage, infection, or other complication was noted during the following period.

CONCLUSIONS

Dural repair can be effectively and durably achieved using autologous fat graft as a dural substitute during skull base approaches, even in cases of extended defects. The observed characteristics of the fat graft along with the achieved outcome make it an ideal dural substitute.