Background and Goal of Study: Postoperative chylothorax occurs in 12 % of pediatric cardiac surgery patients as a rare but severe complication with high resource utilization at intensive care
units. Purpose of this subpart of our study was to determine the long term outcome including factors like mortality and incidence of major complications.
Materials and methods: We performed the secondary analysis of the prospectively collected data of patients presented with chylothorax after cardiac surgery at the intensive care unit of a tertiary national pediatric cardiac center between 2002 and 2012. Data of 48 consecutive patients was included in the analyses. The control group, consisting of cardiac surgery patients without postoperative chylothorax, was propensity matched for preand intraoperative variables. Primary study endpoints were reoperations, genetic abnormalities, major long term complications including cerebral lesions, setbacks of neurodevelopment, epilepsy, thromboembolic events, as well as mortality.
Results and discussion: During the 10year period, 48 patients had chylothorax after pediatric cardiac surgery. The mean survival times were 13.7 years (SD 1.2 years) against 10.5 (SD:0.9) years in the chylothorax and in the control group respectively (logrank test: 0. 97). Cumulative mortality in both groups added up to 29% during the followup period. 33 patients with chylothorax needed at least one reoperation, compared to 23 control patients. During the followup, 5 patients had thromboembolic complications (2 had confirmed thrombophilia) in the chylothorax group, while 3 in the control group. Genetic abnormalities were present slightly less often amongst patients without chylothorax, although not significantly (p=0,362 for both Downand DiGeorge syndromes) Neurologic complications (hypoxic cerebral lesions diagnosed by MRI), epilepsy were frequent in both groups. In the chylothorax group, phrenic palsy was observed more frequently. During the 49 eoperations, chylothorax did not occur.
Conclusion: Long term followup of chylothorax patients did not show an increased mortality or a significant increase in the number and severity of complications compared to other pediatric cardiac surgery patients. Also the fact that during none of the reoperations manifested any chylothorax predicts a multifactorial background of the entity. Although still considered as a serious complication, our data suggests that it does not influence long term outcome.

Outcome after postoperative chylothorax in pediatric cardiac surgery patients, a long term follow-up