Incisional hernia after midline laparotomy: a prospective study.

OBJECTIVE: To study the healing of midline laparotomy wounds. DESIGN: Prospective clinical study. SETTING: County hospitals, Sweden and Iceland. SUBJECTS: 861 patients who underwent midline laparotomy between August 1989 and November 1992. 453 of whom were operated on during the first 20 months, and 408 of whom were operated on during the second 20 months after surgeons had been asked to adjust their technique to achieve a suture length: wound length ratio of more than 4. MAIN OUTCOME MEASURES: Wound dehiscence, wound infection, and incidence of incisional hernia at 12 months. RESULTS: 78/861 patients (9%) developed wound infection. This incidence correlated with previous midline laparotomy and degree of wound contamination. Mean (SD) suture length: wound length ratio increased from 3.6 (1.3) in the first period to 4.9 (1.6) during the second period (p < 0.01), as a result of a reduction in the stitch interval from 1.2 (0.2)-0.9 (0.2) cm (p < 0.01). All other recorded variables were comparable in both study periods. The rate of incisional hernia decreased from 19% (68 of 363) during the first period to 11% (35 of 320) during the second period (p < 0.01). Suture length: wound length ratio < 4, wound infection and age 60 years or more were significantly and independently associated with an increased incidence of incisional hernia. CONCLUSION: Suture technique is a major determinant of incisional hernia in continuously sutured midline laparotomies. Simple adjustments in technique can considerably improve late operative results.