Laparoscopic incisional hernia repair in a porcine model: What do transfixion sutures add?

Surg Endosc (2004) 18: 529–535 DOI: 10.1007/s00464-003-8519-9  Springer-Verlag New York Inc. 2004

Laparoscopic incisional hernia repair in a porcine model What do transfixion sutures add? E. R. Winslow, S. Diaz, K. Desai, T. Meininger, N. J. Soper, M. E. Klingensmith Department of Surgery, Washington University School of Medicine, Box 8109, St. Louis, MO 63110, USA Received: 25 August 2003/Accepted: 17 September 2003/Online publication: 2 February 2004

Abstract Background: The aim of this study was to evaluate the need for transfixion sutures during laparoscopic ventral hernia repair with mesh. Methods: Incisional hernias were created in 14 Yucatan mini-pigs. Animals were randomized to undergo laparoscopic hernia repair either with spiral tacks alone (Tacks) or with tacks and 4 Prolene transfixion sutures (Sutured) using Composix E/X mesh (Davol Inc.). At 4 weeks, exploratory laparoscopy was performed to assess the repair and score adhesions. The abdominal wall was harvested for tensile strength analysis and histologic evaluation. Continuous variables were compared using a two-tailed nonpaired t-test. Results are presented as mean ± standard deviation. Results: The mean hernia size was 8.5 ± 0.5 cm by 5.5 ± 0.7 cm, with no difference between groups. The operative time was significantly longer (p = 0.006) for the Sutured group (62.1 ± 16.8 min) than for the Tacks group (32.3 ± 7.0 min). The number of tacks per repair was equivalent between groups. At necropsy, the mesh in all cases was well incorporated, reperitonealized, and without evidence of migration. No hernias recurred. However, the Sutured group had a significantly (p £ 0.05) higher adhesion score (5.4 ± 3.3) than the Tacks group (2.0 ± 2.7). The tensile strength of the repair zone was no different between groups (Sutured 4.8 ± 1.5 N/cm, Tacks 3.8 ± 1.4 N/cm). On histologic examination, the ratio of inflammatory cells to fibroblasts was similar between groups (Sutured 0.2 ± 0.6, Tacks 0.2 ± 0.3). Only 82% of tacks in each group penetrated the fascia, and the depth of tack penetration was similar between groups (Sutured 3.7 ± 0.3 mm, Tacks 3.9 ± 0.4 mm). Conclusions: In a porcine model, the use of transfixion sutures was associated with longer operative times and Presented at the Residents and Fellows Session of the annual meeting of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES), Los Angeles, CA, USA, 10–15 March 2003 Correspondence to: E. R. Winslow

more adhesions, without improvement in tensile strength or mesh incorporation. A human clinical trial is needed to determine the optimal method of securing abdominal wall mesh. Key words: Laparoscopy — Incisional hernia — Mesh fixation — Porcine model

The problem of incisional hernia will persist as long as surgeons make incisions. Indeed, incisional hernias are responsible for a significant portion of the morbidity in general surgery. It is estimated that incisional hernias complicate up to 20% of laparotomies [11, 17, 22], and their repair has been as challenging as their prevention. The recurrence rate after traditional open primary ventral hernia repair has been reported to be 43% and decreased significantly to 24% with the addition of a mesh prosthesis [20]. However, with the introduction of the laparoscopic approach to ventral hernia repair, the touted possibility of a better repair with even fewer complications was tested. As with any new technology, a period of time has ensued during which the technical details of the repair have evolved. Two of the primary questions facing surgeons performing laparoscopic ventral hernia repair today center around the type of mesh to use and the method of fixation of the mesh. Much has been written about the properties of the available mesh materials. In summary, it has been found that one of the older materials, polypropylene, incorporates into the abdominal wall most efficiently and offers the most in terms of tensile strength [21]. The downside of this material has been the formation of dense adhesions between the mesh and the intraabdominal contents, potentially resulting not only in the surgically ‘‘hostile abdomen’’ but also in enterocutaneous fistulas [2, 6, 8, 32]. The use of expanded polytetrafluoroethylene (ePTFE) mesh is associated with fewer visceral adhesions, but also with less fibrocollagenous ingrowth into the abdominal wall [4]. One of the

530 Table 1. Adhesion scoring system maximum score 11 Score

Extent

Type

Tenacity

0 1 2 3 4

None