Failure of Skull Base Defects Reconstruction after Endonasal Surgery. Complications, Treatment Options and Outcomes

Objective: As the different techniques for reconstruction of skull base defects during the endonasal surgery could be utilized the complications associated with reconstruction failure, treatment options and outcomes need to be determined.

Methods: A retrospective review of patients undergoing endonasal skull base surgery with cerebrospinal fluid (CSF) leak that required a skull base reconstruction was performed. Type of pathologies, reconstruction technique, complications, treatment options and outcomes were collected.

Results: A 117(26,3%) patients with intraoperative CSF-leak were identified among 445 patients with different skull base pathologies operated via endonasal approaches . All patients were operated between 2007 and 2015 in department of neurosurgery of Kazan Interregional Clinical Diagnostic Center.

Transeptal transsphenoidal microsurgical approach with X-ray C-arm control was performed in 8(6,8%) cases, and endonasal endoscopic approach (EEA) with frameless image-guidance was applied at the 109(93,2%) patients respectively. In 13 cases of them an anterior expanded and 2 transclival approaches were performed. There were 47 males and 70 females. Patient’s age was between 17 and 77 years, with mean age of 47,85 years. The mean period of follow-up is 31,5 months.

There were 71(60,6%) patients with pituitary tumors, 9(7,7%) patients with craniopharyngiomas, 3(2,5%) patients with Rathke cleft cyst, 4(3,4%) patients with meningiomas, 4(3,4%) patients with different skull base tumors, 12(10,25%) patients with meningocele manifested with CSF-leak, 2(1,7%) patients with nasal CSF-leak after transcranial tumor removal, 12(10,25%) patients with postraumatic CSF-leak. Different technique of skull base defect reconstructions were utilized: with artificial grafts - 15; with peace of fascia lata and fat graft - 13; mucosa of middle turbinate was used in 5 cases; with vascularized pericranial flap - 2; with vascularized nasal-septal flap - 82.

A postoperative cerebrospinal fluid leak occurred in 20(17%) patients and was a reason of meningitis in 5(4,27%) of them (two aseptic and three bacterial), all were cured. Eleven patients with postoperative cerebrospinal fluid leak underwent a surgical reconstruction of CSF-fistula (three patients twice), in 9 cases CSF-leak resolved on lumbal drain. The most common reason of failure was flap malposition, in one case CSF-leak occurred after radiotherapy and in two cases due to incorrect reconstruction with dead-space formation between in-lay and on-lay layers. No failure due to flap necrosis or perforation was marked. In two patients a postoperative pneumocephalus developed and one patient required an EVD placement and another one a skull base reconstruction. Two patients developed a spinal arachnoiditis due to lumbal drainage. Bothe was cured conservatively. Two patients underwent LP-shunting due to drainage-dependent syndrome. The mortality rate in series was 1,7%.

Conclusions: Scull base reconstruction with vascularized flaps still remains more effective. In case of CSF-leak a repeat surgery more useful than lumbal drain with less risk of increasing number of complications. Also learning curve a critical point impacting on results of endonasal skull base surgery and effectiveness of skull base reconstruction.