A meta-analysis of peritoneal drainage versus laparotomy for perforated necrotizing enterocolitis

Background/Purpose: Both primary peritoneal drainage (PPD) and laparotomy ( LAP) are used widely for treatment of perforated necrotizing enterocolitis (NEC). Published reports include only anecdotes and small series. The autho rs used techniques of meta-analysis to determine which treatment is most ef fective. Methods: The authors identified published studies reporting surgical treatm ent of NEC from January 1, 1978 to December 31, 1999; there were 10 studies (n = 475). The authors were contacted and all available raw patient data f or use in metaanalysis (n = 190) were obtained. The authors used logistic r egression to determine the relative survival rate after PPD and LAP, contro lling for the effect of gestational age and institution. Results: The combined probability of survival in the 10 published studies d id not show an advantage for PPD (55%) or LAP (67%; P=.27). When the author s corrected for the effect of birth weight on survival rate, they still did not observe a difference (P =.67). A marked bias in treatment assignment w as found with smaller babies undergoing PPD than LAP (931 g versus 1,615 g, respectively; P =.0004). Analysis of raw data showed an even greater bias in treatment assignment. The authors found increased survival rate for LAP versus PPD (62.3% v 35.6%; P =.0009). However, a logistic regression model could not overcome the bias in assignment of patients with a much higher ex pected mortality rate to PPD. Conclusions: Using currently available data, it is not possible to determin e whether PPD or LAP is superior. Bias in treatment assignment precludes co nclusions regarding comparative survival. Only a randomized trial will dete rmine which operation is best for the treatment of perforated NEC. J Pediat r Surg 36:1210-1213. Copyright (C) 2001 by W.B. Saunders Company.