Postoperative CD4 counts predict anastomotic leaks in patients with penetrating abdominal trauma

The influence of trauma- and surgical stress-induced decrease of CD4 count on anastomotic leaks after penetrating abdominal trauma has to date not been investigated. A prospective study was performed to explore the effect of CD4 count 24 h after surgery on the anastomotic leak rate and to identify risk factors for anastomotic leaks.

This was a prospective study including 98 patients with small or large bowel resection and subsequent anastomosis due to penetrating abdominal trauma. Univariate analysis identified risk factors for the development of anastomotic leak and also investigated the predictive value of the CD4 count for this complication.

Of the 98 patients 23 patients (23%) were HIV-infected. The overall leak rate was 13%. Univariate analysis including all potential risk factors with p-values<0.05 identified six factors leading to a significantly higher rate of anastomotic complications: postoperative CD4 count<250 cells/μl, postoperative albumin <30 g/L, penetrating abdominal trauma index≥25, gunshot wound as mechanism of injury, blood transfusion requirement >6units and delayed anastomosis after damage control surgery. Survival rates were analysed with the χ² test and did not show a significantly higher mortality rate in patients with low CD4 count. The negative impact of trauma and subsequent surgery on the cell mediated immunity was demonstrated by the fact that 55 (73%) of the HIV-negative patients had a CD4 count less than 500 cells/μl 24 h postoperatively. HIV-infection had no significant influence on the leak rate, however all HIV infected patients that developed an anastomotic leak died.

A low post-operative CD4 count is a predictor for anastomotic leaks irrespective of HIV-serostatus. Low postoperative serum albumin, high injury severity, gunshot wound as mechanism of injury, blood transfusion requirement >6 units and delayed anastomosis were further risk factors for anastomotic complications. Postoperative CD4 count and serum albumin should be considered in the decision making process of performing an anastomosis or diverting stoma for patients after "clip and drop" of the bowel as part of damage control surgery.