Holding Strength of a Hem-o-lok/Lapra-Ty Clip Combination on Sutures Used During Partial Nephrectomy

To investigate the anti-slip strength of closing systems employing sutures terminated with a Hem-o-lok/Lapra-Ty clip combination to determine which sutures perform best for this application. Partial nephrectomy is the reference standard for treatment of small renal masses. The main disadvantage of partial nephrectomy is the risk of technical complications, including renorrhaphy site bleeding and urine leak.

A materials testing system produced a constant velocity pull on the free end of an anchored suture. A Lapra-Ty clip was attached 1 cm from the end of each suture as a backstop for the Hem-o-lok. A digital force gauge measured the tension that was applied until the suture slipped in the closing system. Vicryl, Monocryl, Chromic, Stratafix, and V-Loc sutures of diameters 1 to 4-0 were tested (n = 7 for each suture type, 161 total experiments).

The holding strength of a Lapra-Ty/Hem-o-lok clip combination is lowest for Vicryl 4-0 (4.3 ± 1.4N) and highest for Monocryl 0 (16.5 ± 1.6N) sutures. Larger sutures (1 and 0) hold at higher tensions than sutures with smaller dimensions (4-0 and 3-0). For 2-0 sutures, the holding strength was 5.7N with Vicryl, 13.8N with Stratafix, and 15.9N with V-Loc sutures.

The mean values of holding tension of this anchoring system for all sutures tested was greater than the amount found to be sufficient for tissue closure in previous studies (3.2N). Barbed sutures (Stratafix, V-Loc) appeared to have superior holding strength when compared with most standard sutures; barb orientation does not influence holding tension.