Is abdominal drainage after open emergency appendectomy for complicated appendicitis beneficial or waste of money? A single centre retrospective cohort study.

BACKGROUND: Appendicitis is a medical condition that causes painful inflammation of the appendix. For acute appendicitis, appendectomy is immediately required as any delay may lead to serious complications such as gangrenous or perforated appendicitis with or without localized abscess formation. Patients who had appendectomy for complicated appendicitis are more prone to develop post-operative complications such as peritoneal abscess or wound infection. Sometimes, abdominal drainage is used to reduce these complications. However, the advantage of the abdominal drainage to minimize post-operative complications is not clear. Therefore, the aim of this study was to investigate whether the use of abdominal drainage after open emergency appendectomy for complicated appendicitis (perforated appendicitis with localized abscess formation only) can prevent or significantly reduce post-operative complications such as intra-peritoneal abscess formation or wound infection.

METHODS: In this retrospective cohort study, files and notes were reviewed retrospectively for patients who had open emergency appendectomy for complicated appendicitis (perforated appendicitis with localized abscess formation only) and who had already been admitted and discharged from the surgical wards of Kerbala medical university/Imam Hussein medical city hospital/Kerbala/Iraq. Patients were selected according to specific inclusion and exclusion criteria. Patients were divided into two groups; drainage and non-drainage groups. The drainage group had intra-abdominal drain inserted after the surgery, while the non-drainage group had no drain placed post-operatively. A comparison between both groups was done in terms of these parameters; (i) the development of post operative intra-peritoneal abscess and or wound infection. (ii) The length and cost of hospital stay. (iii) The mortality outcomes. Statistical analysis was done using Pearson Chi-square test, Independent sample t -test and Mann-Whitney U Test.

RESULTS: Of 227 patients with open emergency appendectomy for complicated appendicitis, 114 had received abdominal drain after the surgery. Fifty out of 114 patients (43.9%) with abdominal drainage developed post-operative intra-peritoneal abscess (abdominal or pelvic) while 53 out of 113 patients (46.9%) without drainage developed the same complication ( P  = 0.65). It was also revealed that for patients with drainage, 42 patients (36.8%) had post-operative wound infection, whereas this number was 38 (33.6%) for patients without drainage ( P  = 0.61). On the other hand, the patients with drain had significantly longer length of hospital stay (mean length of stay: 4.99 days versus 2.12 days, P  < 0.001) and significantly higher cost (median cost per patient: $120 versus $60, P  < 0.001).

CONCLUSION: Installation of abdominal drainage after open emergency appendectomy for complicated appendicitis did not bring any considerable advantage in terms of prevention or significant reduction of post-operative intra-peritoneal abscess and wound infection. Rather, it lengthened the hospital stay and doubled the cost of operation.