Mass closure technique: an experimental study on separation of wound edge.

OBJECTIVE

To study separation of wound edges in midline laparotomy incisions closed with either a mass stitch or a stitch incorporating only aponeurosis.

DESIGN

Experimental study in pig.

SETTING

University hospital, Norway.

ANIMALS: 8 domestic pigs.

METHODS

Steel sutures were used and metallic clips were placed in the aponeurosis. After increasing the intra-abdominal pressure the distance between the lateral edge of stitches and between pairs of clips was measured on sequential radiographs.

RESULTS

After three hours with raised intra-abdominal pressure the lateral edge of stitches became separated by a mean (SD) of 5.6 (1.3) mm with a mass stitch and by 0.5 (0.6) mm with stitches placed only in the aponeurosis (p < 0.001). Corresponding figures for separation of clips was 3.6 (1.5) mm and 0.1 (0.3) mm (p < 0.001). The suture cut through the muscle by more than 3mm in 25 out of 36 mass stitches. Muscle and peritoneum included in the mass stitch was compressed, darkly discoloured, and there were signs of haemorrhage.

CONCLUSIONS

Wound edges become separated with a mass stitch but not with stitches placed only in the aponeurosis when the intra-abdominal pressure is raised after closure of midline laparotomy incisions. This results from sutures compressing or cutting through subcuticular fat, muscle, and peritoneum enclosed in a mass stitch.