Epidural Inlay for Pituitary Adenoma Surgery: A 4-Year Institutional Experience

Objective: Numerous sellar repair techniques have been developed to reduce the incidence of postoperative cerebrospinal fluid (CSF) leak following endoscopic transsphenoidal pituitary surgery. The complexity and effectiveness of these techniques have improved in recent decades. This study describes our institutional experience with a minimalistic and highly effective approach to sellar repair.

Methods: The authors conducted a retrospective review of consecutive endoscopic transsphenoidal pituitary cases performed in a single institution since the exclusive adoption of the epidural inlay repair technique by the authors in 2018. The technique involves a single-layer dural closure with a collagen matrix graft and use of dural sealant regardless of whether intraoperative CSF leak is encountered. The graft is tucked smoothly in the epidural space behind the bony ledges of the sellar opening and is supplemented in select cases of high-flow CSF leak with sellar fat packing, nasoseptal flap, and/or lumbar drain. Rates of intraoperative and postoperative CSF leak were analyzed. Patient and tumor characteristics were additionally examined for potential risk factors for CSF leak and use of supplemental sellar repair methods.

Results: Three hundred and sixteen consecutive cases involving intrinsic lesions of the pituitary gland and stalk over 4 years were included. Twenty cases which did not utilize the epidural inlay were excluded. These consisted of 8 cases of Rathke's cysts where the dura was intentionally left open and 12 resections that lacked an adequate bony ledge to tuck in the graft. CSF leak was encountered intraoperatively in 108 cases (34.2%) and postoperatively in only one case (0.3%) early in the series. Sixty-one intraoperative CSF leaks (56.5%) were successfully repaired with an epidural inlay only, whereas the remainder underwent additional fat packing (31.5%), nasoseptal flap (11.1%) or both (0.9%). Lumbar drain was used in 31.5% of cases with intraoperative leak, and 12.0% overall. Redo cases had higher rates of intraoperative CSF leak (p = 0.0011) and more frequently utilized supplemental sellar repair methods (p < 0.0001). Surgeries in the second half of the series were less likely to undergo adjunct measures than in the first half (p < 0.0001) despite having equivalent rates of intraoperative CSF leak. This was largely due to increased reliance on the repair technique over time allowing the authors to avoid fat packing in all but one of the most recent 137 cases. Rate of lumbar drain usage also decreased from 17.0 to 4.5% (p = 0.0007), whereas use of nasoseptal flap (4.4%) remained consistent throughout the series. This repair technique was employed by two different attending neurosurgeons and many neurosurgical trainees, proving reproducibility.

Conclusions: Simple single-layer sellar repair with an epidural inlay graft was highly effective in preventing post-operative CSF leak when used empirically or in cases of intraoperative leak. Lumbar drain or nasoseptal flap are mainly employed in select cases of high-flow intraoperative CSF leak, and use of fat packing is now exceedingly rare. Despite the various skill levels of surgeons employing this technique, from junior residents to senior faculty, there has been no postoperative CSF leak at our institution in nearly 300 consecutive pituitary surgeries.

Publication History

Article published online:
01 February 2023