Wound strength in abdominal incisions: A comparison of two continuous mass closure techniques in rats

Abstract

OBJECTIVES: The primary objective of this study was to determine whether continuous simple mass closure or continuous far-near, near-far (Smead-Jones) mass closure of longitudinal midline abdominal incisions results in a stronger wound. A second objective was to compare the time required to perform each type of closure. STUDY DESIGN: A midline laparotomy was performed on 102 male Sprague-Dawley rats. the skin was incised from xiphoid to pubis and reflected away from the midline. The rectus sheath was imprinted with a stamp to demarcate a standardized 5 cm midline incision. The stamp also provided loci for suture bites 5 mm from the incision edge and 10 mm apart. A longitudinal midline incision was made. Closure technique was determined by random assignment. The time required to close each incision was recorded. On postoperative day 7 wound strength was measured by inserting a condom into the abdomen and filling it with water until the abdomen burst. Pressure was measured in millimeters of mercury. Student t test, χ 2 test, and Fisher's exact test were used for statistical analysis. RESULTS: Animals closed with the continuous simple mass closure ( n = 50) had a mean weight of 344.43 ± 33.2 gm (mean ± SD) and those closed with the continuous far-near, near-far mass closure technique ( n = 52) weighed 344.86 ± 36 gm. Abdominal bursting pressure was 480.8 ± 62.6 mm Hg in the continuous simple group, whereas it was 554.4 ± 63.6 mm Hg in the continuous far-near, near-far group ( p < 0.000001). The time required to close the wound with the continuous simple technique was 365.4 ± 66.2 seconds. The continuous far-near, near-far closure group required 570.6 ± 70.8 seconds ( p < 000001). CONCLUSION: Our study reveals that the continuous far-near, near-far mass closure technique results in significantly greater wound strength than the continuous simple mass closure on the basis of the intraperitoneal pressure required to burst the abdomen. We believe that the far-near, near-far closure provides superior strength by creating two loops of suture over which forces that may disrupt the wound can be distributed. Furthermore, use of a continuous suture for this technique distributes tension along the entire length of the incision. Disruptive forces are thus divided evenly among all suture sites. A second purported advantage of continuous closur is the speed with which it can be performed. However, the greater wound strength of the continuous far-near, near-far technique comes at the expense of requiring 56% more time to complete than the continuous simple mass closure. Our data suggest that greater wound security is worth the increased time required for this repair.