Mismatch of tissue thickness and staple height can lead to staple-line bleeding. Reinforcement with the bovine collagen staple line buttress Peri-Strips Dry with Veritas (PSDV)(Baxter) reduces incidence and severity of bleeding, and is associated with a reduction in surgical time. A new ultrathin PSDV buttress minimizes overall tissue thickness stapled. This study investigates the biomechanical properties and tissue response of standard thickness (PSDV) and ultrathin (PSDV-UT) bovine collagen staple-line buttresses.
Maximum load, tensile stress and strain of each buttress, 125 x 25 mm, were measured per ASTM standard D638-03 at 0.2 mm/s until failure. Tensile stress investigated elongation, tensile strain investigated dimensional change and Young’s Modulus investigated deformation and stiffness. 246 patients completed a program of monthly preoperative nutrition education group classes through standardized lectures led by registered dieticians. Patients completed a preoperative test to assess nutrition education recall and subsequently a 2-week postoperative survey that assessed achievement of nutrition goals. Bivariate statistics including independent sample t-test and Pearson’s correlation test were used to examine the association between total preoperative test score, self-reported completion of recommended nutrition goals, and percent excess weight loss(%EWL).
Tissue reaction to each buttress, 8-mm diameter, were investigated in a rodent model at 1, 3 and 6 weeks. One of each buttress was implanted subcutaneously through a 3-cm dorsal incision in 10 rats per time point. PSDV and PSDV-UT had similar maximum loads (30.1±13.2 vs 45.2±22.7 N, N=8/group, P=0.14), tensile stress (4.1±1.3 vs 5.8±2.8 MPa, P=0.14), strain (17.9±3.2 vs 23.9±10.5%, P=0.16) and Young’s Modulus (51.2±14.0 vs 57.6±16.6 MPa, P=0.42). At 1 week, histiocytes were predominant and penetrated PSDV greater than PSDV-UT (0.17 vs 0.07 mm). At 3 weeks, fibroblasts, multinucleated giant cells and histiocytes were present in mixed populations. At 6 weeks, fibroblasts predominated and penetrated PSDV greater than PSDV-UT (0.19 vs 0.14 mm).
The biomechanical properties were similar despite the different thicknesses. The tissue reaction was typical, expected and similar with slightly greater cellular penetration into the PSDV buttress.