Post Operative Chylothorax Development is Associated with Increased Incidence and Risk Profile for Central Venous Thrombosis

Background: Chylothorax (CTX) is a complication reported to occur postoperatively in up to 4% of all pediatric patients requiring surgery for congenital heart disease. It has been associated with prolonged ventilator dependence, increased length of hospital stay, malnutrition, infection, and death. The available treatment modalities are either ineffective, associated with substantial risk, or both. Prevention of CTX appears to be the best option.

Objective: We hypothesized that pediatric patients who develop CTX after surgery for congenital heart disease have an elevated incidence and risk profile for central venous thrombosis (CVT).

Design/Methods: A retrospective chart review was performed of 30 patients found to have developed CTX at the University of Virginia after surgery for congenital heart disease. All but one CTX patient were surgery, anatomy, and age matched with two controls (NON-CTX) to compare their relative risk and incidence of CVT.

Results: Using conditional logistic regression analyses, CTX development was associated with significantly longer ventilator dependence (14.8±10.9 vs. 6.1±5.9, p=0.003) and a non-significant trend towards more days of central venous catheters (CVC) (19.1±16.6 vs. 12.2±10.0 days; p=0.16) when comparing the period prior to CTX development in the CTX group with the entire hospitalization in NON-CTX patients. CTX development was also associated with a significantly elevated mortality risk (6.2; 95% CI 1.3-30.9). Minimum, maximum, and average daily central venous pressures were significantly higher in the CTX group. Post operative need for extracorporeal membrane oxygenation conferred an increased risk of CTX development in this sample of patients (9.9; 95% CI 2.2-44.8). Incidence of documented CVT was 26.7% in the CTX group verses 5.1% in the NON-CTX group.

Conclusions: CTX portends a significantly worse outcome in pediatric patients who are status post surgery for congenital heart disease. Prospective screening for CVT risk and formation, combined with early removal of CVCs may help reduce the incidence of CTX.