The legendary superior strength of the Pfannenstiel incision: A myth?

OBJECTIVE: This study was undertaken to determine whether there is a differ ence in the frequency of fascial dehiscence between midline vertical lower abdominal and Pfannenstiel incisions among women undergoing obstetric and g ynecologic operations. STUDY DESIGN: A case-control study of 48 cases of fascial dehiscence compli cating 17,995 major operations (8950 cesarean deliveries and 9405 gynecolog ic procedures) during a 6-year period at Wayne State University Hutzel Hosp ital, Detroit, was performed. Univariate analysis identified significant in dependent variables related to fascial dehiscence. Stepwise logistic regres sion analysis then identified those risk factors that were independently as sociated with fascial dehiscence. RESULTS: Among the 48 patients who underwent repair of fascial dehiscence a fter a major obstetric or gynecologic operation, 27 were from the obstetric service and 21 were from the benign and cancer gynecologic services. Wound dehiscence occurred in 10 vertical incisions and 17 Pfannenstiel incisions among the obstetric patients and in 12 vertical and 9 Pfannenstiel incisio ns among the gynecologic patients. The risk for dehiscence with vertical lo wer abdominal incisions was not increased with respect to that associated w ith Pfannenstiel incisions (P = .39, 2-tailed). This finding was true for a ll patients (odds ratio, 1.3; 95% confidence interval, 0.7-2.6), obstetric patients (odds ratio, 1.3; 95% confidence interval, 0.5-3.4), and gynecolog ic patients (odds ratio, 1.5, 95% confidence interval, 0.5-4.0). Forty-seve n of the 48 case patients had documented wound infections, compared with 1 of the 144 control subjects (P < .0001, odds ratio, 37.8; 95% confidence in terval, 14.8-96.8). CONCLUSION: Wound infection was the most important risk factor for fascial dehiscence among women who underwent major obstetric and gynecologic operat ions. Our results do not support the long-held belief that Pfannenstiel inc isions are stronger than lower abdominal vertical incisions and reduce the risk for fascial dehiscence.