Primary Dural Repair after Endoscopic Endonasal Approaches to the Cribriform Using Nonpenetrating Titanium Clips: Initial Experience and Surgical Technique

Objective Endoscopic endonasal repair of dural defects of the anterior skull base is challenging. We demonstrate a novel method of endoscopic endonasal primary dural repair using nonpenetrating microclips.

Methods We present three patients who underwent repair of dural defects of the cribriform plate with microclips. The first case involved an esthesioneuroblastoma, the second a traumatic neuroma, and the third a spontaneous cerebrospinal fluid leak.

Results As part of a multilayered technique, the defects were primarily repaired using microclips and a dural graft. None required lumbar drain placement. None developed cerebrospinal fluid leaks. Clip usage did not interfere with interpretation of postoperative imaging.

Conclusion In our preliminary experience, endoscopic endonasal repair of dural defects near the cribriform plate with nonpenetrating clips is a feasible adjunct to multilayered closure techniques and may be used as a bailout technique when traditional methods are not tenable.

Technique The dural defect is defined with boney removal as necessary (Fig. 1). A dural graft is shaped to expand beyond the defect by 0.5 to 1 cm in all directions. The graft is positioned and folded over the edges of the defect to facilitate clip placement (1c). Microclips are applied along the margins until the graft is secured.

Fig. 1 (a–c) A diagram of the anterior skull base dura mater in the coronal plane along the olfactory groove. (b) In this exmaple, a transcribriform approach has been completed. Boney removal is extended beyond the margins of the resulting dural defect. (c) A sized dural graft has been apposed to the dural edges and clipped into place. (d) Diagram of endoscopic endonasal view after completion of clippling technique. (e–f) Cadaveric dissection illustrating repair technique after Draf III frontal sinusotomy and endoscopic endonasal transethmoidal transcribriform approach. The dural defect has been primarily repaired using a synthetic dural graft and microclips.

Case 1 An 82-year-old man presented with lacrimation and olfactory disturbance. A nasal cavity mass extending from the cribriform plate was found (Fig. 2a–c). Pathology confirmed esthesioneuroblastoma. After nasal component resection, an endonasal transcribriform approach was performed. After tumor resection, a dural graft was secured as part of a multilayered closure using the clip technique (Fig. 2d–h). There were no complications. The patient discharged on postoperative day 4. Postoperative imaging is demonstrated in Fig. 2j–n. The patient has not demonstrated CSF leak at 9-month follow-up.

Case 2 A 37-year-old man presented with headache and nausea. A lesion thought to represent a meningioma was found (Fig. 3a, b). Pathology revealed a traumatic neuroma. After completion of a Draf III frontal sinusotomy, an endonasal transcribriform approach was performed. After lesion resection, the defect is measured (Fig. 3c, d) and a dural graft is positioned (Fig. 3e, f). Working in a circular fashion, clips were used to affix the graft (Fig. 3g–k). Closure was completed with a fat graft and nasoseptal flaps. The patient was discharged on postoperative day 3. There were no immediate complications. Postoperative imaging is demonstrated in Fig. 3l–o. Eight months later, the patient developed an obstructed left maxillary sinus requiring antrostomy. No CSF leak developed at 10 months of follow-up.

Case 3 An 18-year-old female with a history of pseudotumor cerebri presented with rhinorrhea and neck pain. A small defect along the right olfactory groove was confirmed (Fig. 4a–c). Once the defect margins were identified, a graft was clipped in place (Fig. 4d–f). Closure was completed with a free middle turbinate mucosal graft. There were no complications and the patient was discharged on postoperative day 3. Four months postoperative imaging is demonstrated in Fig. 4 g–i. The patient developed sinusitis 3 months postoperatively requiring antibiotics. No CSF leak developed at 7 months of follow-up.

Fig. 3 Pre-operative (a) axial T1-weighted contrast-enahcnced and (b) sagittal T2-weighted MRI demonstrating a skull base lesion of the left olfactory groove. This lesion was thought to represent a meningioma initially. However, pathology revealed a diagnosis of truamatic neuroma. After completion of a Draf III frontal sinusotomy, a transfovea ethmoidalis transcribriform approach was completed. Standard endoscopic techniques were used to resect the lession. (c, d) After completing tumor resection, the dural defect is measured. (e, f) The dural graft is placed over the defect and folded back on itself using a right angled dissector. (g–i) Working in a circular fashion, the dural graft is secured in all directions using the clip technique. Lower (j) and higher (k) magnification of the defect after clipping the dural graft. The closure was completed with a fat graft, bilateral nasoseptal flaps, and nasal packing. (l, m) Sagittal and coronal post-operative CT demonstrating secure graft placement (green arrows). (n, o) Post-operative MRI demonstrating complete resection of the tumor. The abdominal fat graft and clip artifact are noted with green arrows.

Fig. 4 (a) Sagittal T2-weighted MRI demonstrating a hyperintense signal along the olfactory groove in a patient with a cerebrospinal fluid leak. (b) Pre-operative coronal CT revealing an asymmetric boney defect along the right anterior cribriform. (c) Endoscopic view confirming identification of dural defect. Fluorescein dye is noted. (d) After exposing the dural defect, a sized dural graft is positioned. (e, f) The clip technique is used to affix the dural graft in place. Note that in an attempt to minimize olfactory manipulation further boney removal was not performed. The closure was completed with a free middle turbinate mucosal graft and nasal packing. Post-operative (a) axial MRI and axial CT (h, i) demonstrating minimal clip artifact (green arrows).