Congenital Heart Surgery

Risk factors for postoperative pulmonary venous obstruction after surgical repair of total anomalous pulmonary venous connection: a systemic review and meta-analysis Han Zhang , Guocheng Shi and Huiwen Chen. Interact Cardiovasc Thorac Surg. 2022 Aug; 35(2): ivac162. PMID: 35713512   Take Home Points: 1) A total of five risk factors were identified to be associated with pulmonary vein obstruction(PVO) after surgical repair of total anomalous pulmonary venous connection(TAPVC), including: preoperative PVO, conventional operative procedure(compare with a sutureless procedure), a mixed type TAPVC, and longer cardiopulmonary bypass and aortic cross-clamp time.     Commentary from Dr. Shuhua Luo (Chengdu, Sichuan, China), section editor of Congenital Cardiac Surgery Journal Watch: Summary: This meta-analysis included 2,385 individuals in 16 retrospective studies undergoing surgical repair of TAPVC. Five risk factors were significantly associated with postoperative PVO. Patients with preoperative PVO [odds ratio (OR)=5.27, 95% confidence interval (CI) = (2.75, 10.11), P < 0.01],  a mixed type TAPVC[OR = 3.78, 95% CI=(1.08, 13.18), P = 0.04], longer cardiopulmonary bypass time [hazard ratio (HR)=1.01, 95% CI=(1.01, 1.02), P < 0.00001] and aortic cross-clamp time [HR = 1.01, 95% CI=(1.01, 1.02), P < 0.01] were significantly associated with postoperative PVO.  Compared with a sutureless procedure, the conventional operative procedure was associated with postoperative PVO [OR = 1.80, 95% CI=(1.20, 2.71), P < 0.01]. On the contrary, the heterotaxy was not identified as a risk factor for postoperative PVO. Comment: PVO is one of the most important complication of TAPVC repair, occurring in 15-20% of the survivors, has been associated with increased morbidity and mortality. Therefore, identifying risk factors for postoperative obstruction is essential for appropriate counseling and clinical care. The authors should be congratulated for providing a more general estimate of risk factors for postoperative PVS. However, more questions may be raised. The author stated that the postoperative PVO definition was clear in the included studies, however, the definitions in the individual studies were various, including Doppler velocity by echocardiography(1), pulmonary vein reintervetion(2), or pulmonary vein dimension based on the angiography(3). Furthermore, PVS can also present with considerable variability in patients as it can occur in one or more of the pulmonary veins and can be bilateral or limited to unilateral disease. Lesions in the pulmonary veins can be discrete at the venoatrial junction or can be diffuse, extending along the length of the intraparenchymal, and the velocity at which the disease progresses can range from indolent to aggressive and relentless. This reflects the current challenges in PVS diagnosis, which need to be addressed in the future study. The authors also reported that heterotaxy was not strongly associated with the postoperative PVO of TAPVC. However, this finding should be interpreted with caution. The heterogeneity of the data was high as only three studies were included in the meta-analysis of heterotaxy. High postoperative mortality may further impact the occurrence of postoperative PVO in the follow-up period. The etiology of PVS has remained elusive and likely has multifactorial factors including genetic, developmental, and hemodynamic contributions. There is an unmet need to provide better evidence for incremental knowledge gains, and improved outcomes for children diagnosed with PVS.  Reference 1) White BR, Ho DY, Faerber JA, Katcoff H, Glatz AC, Mascio CE, et al. Repair of Total Anomalous Pulmonary Venous Connection: Risk Factors for Postoperative Obstruction. Ann Thorac Surg. 2019 Jul;108(1):122–9. 2) Husain SA, Maldonado E, Rasch D, Michalek J, Taylor R, Curzon C, et al. Total Anomalous Pulmonary Venous Connection: Factors Associated With Mortality and Recurrent Pulmonary Venous Obstruction. Ann Thorac Surg. 2012 Sep;94(3):825–32. 3) Seale AN, Uemura H, Webber SA, Partridge J, Roughton M, Ho SY, et al. Total Anomalous Pulmonary Venous Connection.