Dural repair efficacy assessment of different techniques, a cadaveric study comparing the naked eye and surgical loupes

Abstract

Background: Watertight dural repair is crucial to achieve successful dural tear sutures. Microscopic or surgical loupes are recommended to use to magnify and assist repairing the dura. However, many spine surgeons repair dural tears under the naked eye. The efficacy of repairing dural tears by the naked eye compared with microscopic or surgical loupes has never been studied. Objective: This study aimed to compare the efficacy of dural repairing techniques using the naked eye or surgical loupes. Methods: A cadaveric experimental study was conducted. Four fresh human cadaveric specimens were used to harvest the spinal cord. Dural tear and CSF leakage were simulated with a water pressure control system (Arthrex AR-6475 arthroscopic pump). We compared surgical repair using the naked eye and surgical loupes. Surgical closure was achieved using Prolene 6-0 and Durepair®. A total of 32 experimental dural tears were subdivided to four groups. The 4 groups were Prolene6-0 with the naked eye (n=8), Prolene 6-0 with surgical loupe (n = 8), Durepair® with the naked eye (n=8) and Durepair® with surgical loupe (n=8). The total time used for sutures and postsuture CSF water leakage pressure were recorded and compared among the subgroups. Results: Our results showed that surgical loupe assisted dural closure and sutures were significantly faster than the naked eye in both Prolene 6-0 (surgical loupe = 4.87±0.19 min, naked eye = 7.18±0.36 min, p <0.001) and Durepair® groups (surgical loupe = 9.84±0.21 min naked eye = 13.27±0.42 min, p <0.001). CSF Leakage pressure in the surgical loupe groups were higher than in the naked eye groups in both Prolene 6-0 (surgical loupe = 100.00±5.35 mmHg, naked eye = 96.88±7.99 mmHg, p = 0.373) and Durepair® (surgical loupe = 96.88±4.58 mmHg, naked eye = 95.63±4.17 mmHg, p = 0.577) but without significant difference. Prolene 6-0 was significantly faster to use for sutures than Durepair® in both sutures by the naked eye and surgical loupe assisted (p <0.001). Prolene 6-0 showed a higher leakage pressure than Durepair® in both the naked eye and surgical loupe assisted sutures but without significant difference (naked eye, p = 0.701, surgical loupe, p = 0.230) CONCLUSION: Repairing a dural tear without using surgical loupes consumed more time and did not achieve similar maximum leak pressure compared with using surgical loupes. However, no statistically significant difference was observed in terms of CSF leakage pressure. Durepair® consumed more time than Prolene 6-0 while leakage pressure was similar. We recommended the use of surgical loupes when performing dural repair. Durepair® is suitable to repair larger dural defects that cannot be closed using a simple suture technique.