Pre- and postoperative levels of serum brain-derived neurotrophic factor in neonates with congenital heart defects.

Background: The objectives of this study were to assess the preoperative and postoperative serum brain- derived neurotrophic factor (BDNF) levels in neonates undergoing surgery for congenital heart defects (CHD). Also to explore the relationship between changes in BDNF levels and the impact of perioperative factors including intraoperative body temperature, aortic cross-clamp time, perfusion time, operation time, inotropic score, vasoactive inotropic score and lactate levels.

Methods: Forty-four patients with CHD and 36 healthy neonates were included in the study. Blood samples for serum BDNF levels were collected three times: preoperatively, and at 24 and 72 hours postoperatively from each patient in the operated group. Additionally, samples were collected once from each individual in the non-operated case group and the control group. Serum BDNF levels were analyzed using the Elabscience ELISA (Enzyme-Linked Immunosorbent Assay) commercial kit. Cranial ultrasonography (USG) was performed on all infants with CHD. Following cardiac surgery, patients underwent second and third cranial USG examinations at 24 and 72 hours postoperatively, respectively.

Results: Forty-four consecutive patients with CHD were divided into two groups as follows: the operated group (n=30) and the non-operated group (n=14). Although there were no differences in the baseline serum BDNF levels between the case and control groups, the preoperative serum BDNF levels were significantly lower in the patients operated compared to the non-operated patients. The serum BDNF levels at the 24th hour postoperatively were higher than the preoperative levels. However, no significant correlation was found between the serum BDNF levels at 24 and 72 hours postoperatively as well as the cranial USG findings at corresponding times.

Conclusions: Serum BDNF levels were initially lower in neonates with CHD who underwent surgery, but increased during the early postoperative period. These results suggest that serum BDNF levels are influenced by CHD and the postoperative period.