Skull Base Dural Closure Using a Modified Nonpenetrating Clip Device via an Endoscopic Endonasal Approach: Technical Note

Abstract

Skull base reconstruction after an endoscopic endonasal approach into the cerebrospinal fluid (CSF) space is always challenging. Various reconstructive methods are available, but no standard technique is established. This report describes the endoscopic skull base dural closure using a modified nonpenetrating clip device with shaft length of 15 cm. Six patients with an intra-suprasellar or suprasellar tumor who underwent extended endoscopic endonasal transsphenoidal surgery were targeted. For closure of the skull base dural defect after tumor removal, fascia lata was first placed as an inlay graft and was subsequently fixed with the dura using a modified nonpenetrating clip device. No CSF leakage from the closed dura with an inlay fascia lata fixed with clips was confirmed by the Valsalva maneuver. To complete skull base reconstruction, fascia lata was then positioned as an overlay graft and covered with vascularized pedicled nasoseptal flaps. Five of six patients experienced no CSF rhinorrhea postoperatively. The modified nonpenetrating clip device may achieve effective dural closure in the deep and narrow nasal cavity. We introduce this clip device technique as one of the endoscopic skull base dural closure methods.

Keywords: endoscopic skull base surgery; extended endoscopic endonasal transsphenoidal surgery; nonpenetrating titanium clip; skull base dural closure.

Fig. 1

The modified AnastoClip Vessel Closure System with shaft length of 15 cm (an extra-large-sized type). Enlarged insert image shows that the tip is slightly curved.

Fig. 2

Preoperative and postoperative brain imaging of case 1. Preoperative sagittal T1-weighted magnetic resonance imaging (a) and axial computed tomography scan (b) showing an intra-suprasellar tumor with cystic and densely calcified solid components, extending superiorly into the third ventricle. Postoperative sagittal T1-weighted magnetic resonance imaging (c) and axial computed tomography scan (d) demonstrating total removal of the tumor.

Fig. 3

Intraoperative images of case 1. (a–c) Dural closure using the modified AnastoClip Vessel Closure System after placing fascia lata as an inlay graft at the skull base dural defect. (d, e) Controlling venous oozing due to clip application with absorbable gelatin sponge (yellow circle). (f) Closure of the skull base dural defect with an inlay facia lata fixed with eight nonpenetrating clips taking 8 minutes and 18 seconds. (Supplementary movie is available online)

Fig. 4

Postoperative brain imaging of case 1. Postoperative axial computed tomography scan (a, b) and magnetic resonance imaging (c) showing the applied clips without marked metallic artifact (green circle). (d) Postoperative coronal magnetic resonance imaging demonstrating that the applied clips had little effect on postoperative assessment.