An evaluation of risk factors in incisional hernia recurrence.

In the present study, generally accepted risk factors for developing a primary incisional hernia are reviewed for their influence on the development of recurrent incisional hernia. The records of 417 patients undergoing an incisional hernia repair between 1980 and 1989 at the University Hospital Rotterdam were reviewed retrospectively, and in the event no hernia recurrence was documented, patients were asked to visit the outpatient department for physical examination. Patients having a primary incisional hernia (n = 302) were selected and patient related factors of gender, age, obesity, chronic cough, prostatism, constipation, diabetes mellitus and the use of corticosteroids were analyzed. In addition, operation related factors, including the technique of operation (mainly, one layer interrupted and one layer continuous closures), use of drains, use of antibiotics, wound contamination (fecal or purulent spill), duration of operation, technique of anesthesia, wound complications, mortality and period of hospitalization, were analyzed. Hernia related factors--the hernia-free interval, original operation, type of incision and the size of the hernias--were also analyzed. Statistical analysis of the data was performed using the chi-square test to compare percentages between groups. Cumulative percentages of patients having a recurrence along time were calculated using life-table methods. Of the group of primary incisional hernias, four patients lacked follow-up evaluation and were excluded, leaving 298 patients for study. With a mean follow-up period of 34.9 months, the recurrence rate was 36 percent; 45 percent had recurrence in the first year, 64 percent in the second year and 78 percent of all recurrences occurred within three years. Therefore, a follow-up evaluation of at least three years is recommended. The cumulative (life-table) recurrence rate after five years was 41 percent. After second, third and fourth incisional hernial repair, recurrence rates were higher (56, 48 and 47 percent, respectively). Except for the size of the hernia, none of the studied parameters led to a significantly higher recurrence rate. Obesity, diabetes mellitus, lower midline incision and wound infection did have higher recurrence rates, but these were not significant. Incisional hernias, smaller than 4 centimeters, had a significantly (p = 0.01) lower recurrence rate (25 percent) than larger hernias (41 percent). Considering these facts, a better technique is badly needed. In large defects, the use of inlay of prosthetic material consistently has the lowest recurrence rates. The question remains whether or not prosthetic material is also needed for repair of smaller hernias.