Sequelae of autologous fat graft used for reconstruction in skull base surgery.

The use of an autologous free fat graft is a widely applied technique to obliterate dead space and reinforce dural closure during skull base reconstructions. The associated complications and outcomes of this practice have not been studied. Dissemination of fat in the subarachnoid space resulting in lipoid meningitis has been reported after translabyrinthine approaches, and leakage of liquefied fat is seldom reported in the literature. This study aims to evaluate the morbidity associated with the usage of autologous fat graft in reconstruction of skull base defects based on an extensive experience. This study is a retrospective review of 1581 cases in which the senior author (O.A.) used a skull base approach for the resection of tumor. Autologous fat grafts were used for reconstruction in 974 cases and 10 cases (male to female ratio, 4:6) in which there were associated complications were analyzed. Complications included leakage of sterile liquefied fat from fistula (patients 1, 2, 3), delayed cerebrospinal fluid leak after radiation (Patients 5, 6, 9), and postoperative lipoid meningitis (Patients 4, 7, 8, 10). The onset ranged from 11 days to 10 years. Four patients were managed conservatively, and the other six required surgical intervention. All patients had good outcomes after treatment. The use of autologous fat is associated with a 1% complication rate and should be considered a safe and effective method for skull base reconstruction. However, neurosurgeons should be aware of early and late complications of fat necrosis, including sterile liquefied fat fistula, cerebrospinal fluid leakage, and lipoid meningitis.

Taha AN ，Almefty R ，Pravdenkova S ，Al-Mefty O ... -  《-》

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

Reconstruction of the skull base after resection of skull base meningiomas is of paramount importance. Here we describe a safe and effective method of skull base reconstruction using autologous free fat grafts. In this retrospective analysis of patients operated for skull base meningioma from 2007 to 2014. We analyzed the surgical technique, efficiency and safety as well as the graft-related complications. Autologous free fat grafts were used in 55 patients, including 39 patients with posterior fossa meningiomas related to the petrous bone and 16 patients with anterior fossa meningiomas related to the paranasal sinuses. Three patients experienced postoperative cerebrospinal fluid (CSF) leak and were managed with temporary continuous lumbar drainage. One patient developed pneumocephalus and required revision. The occurrence of CSF leak was related to aggressive resection with resulting large skull base defects, especially in anterior skull base meningiomas. There were no donor site-related complications. The use of autologous free fat grafts is an effective and safe technique for reconstructing skull base defects after microsurgical resection of skull base meningiomas.

Metwali H ，Gerganov V ，Nery B ，Aly A ，Avila-Cervantes R ，Samii M ... -  《-》

Revision lateral skull base surgery.

Kaylie DM ，Wittkopf JE ，Coppit G ，Warren FM 3rd ，Netterville JL ，Jackson CG ... -  《-》

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

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. 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. 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. 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.

Bohoun CA ，Goto T ，Morisako H ，Nagahama A ，Tanoue Y ，Ohata K ... -  《-》

Very delayed CSF leak in patients after craniotomy for resection of skull base tumors.

Cerebrospinal fluid (CSF) leak is a potentially dangerous neurosurgical complication. Delayed CSF leak has already been described after trauma, radiation therapy and endonasal transsphenoidal surgery for Sella turcica pathologies. Still, very few reported cases describe delayed CSF leak after craniotomy for tumors. We present our experience with patients showing delayed CSF leak after skull base tumor resection. Data for all tumors resected from the skull base region from January 2004 to December 2018 was retrieved from the surgeon's prospective database and supplemented with a retrospective file review. Patients who presented CSF leak within the first 12 months after surgery and those with a history of trauma or radiation-based treatment to the skull base region were excluded from the study. Epidemiology, clinical presentation, previous surgical approach, pathology, interval between craniotomy and CSF leak and proposed treatment were analyzed. Overall, more than two thousand patients underwent surgery for resection of skull base tumors during the study period. Six patients (two male, four female; mean age 57.5 years, range 30-80) presented with delayed CSF leak, including five (83%) who presented with bacterial meningitis. After skull base tumor resection, CSF leak developed in a mean of 72 months (range 12-132). Three patients underwent retrosigmoid craniotomy, two for resection of cerebellopontine angle epidermoid cyst and one for resection of a petro tentorial meningioma; one had trans petrosal retrolabyrinthine craniotomy for resection of a petroclival epidermoid cyst; one had far lateral craniotomy for resection of a foramen magnum meningioma; and one had pterional craniotomy for resection of a cavernous sinus meningioma. All patients underwent surgical re-exploration and repair. CSF leak was managed with mastoid obliteration in five patients and skull base reconstruction with fat graft in one. Recognition of very delayed CSF leak as a potential complication after resection of skull base tumors may be useful tool in long-term patient management. In our experience, these patients usually present with bacterial meningitis. Surgical options should be considered as a definitive treatment.

Masalha W ，Kahanov L ，Spektor S ，Kaye AH ，Kroger A ，Moscovici S ... -  《-》