Impact of preservation of the azygos vein during surgical repair of esophageal atresia-tracheoesophageal fistula (EA-TEF): a systematic review and meta-analysis

Abstract

Esophageal atresia-tracheoesophageal fistula (EA-TEF) is one of the common congenital anomalies occurring in newborns. Over the last eight decades, various technical modifications have been proposed in the surgical repair of EA-TEF. Preservation of azygos vein is one such modification that has gained considerable attention. However, a consensus statement regarding the superiority of its preservation over its division is lacking. We aim to compare the outcomes of surgery between the two groups of newborns, i.e., those undergoing repair with and without azygos vein preservation, in terms of its complications. The authors systematically searched the databases PubMed, EMBASE, Web of Science, and Scopus through December 2020. The incidence of anastomotic complications and chest infection was compared among the two groups of newborns, i.e., those undergoing surgical repair with (group A) and without azygos vein preservation (group B). Statistical analysis was performed using a fixed-effects model, and pooled risk ratio (RR) and heterogeneity (I²) were calculated. The methodological quality of the studies was assessed using the Downs and Black scale. Six comparative studies, consisting of a total of 671 newborns, were included in the meta-analysis. As compared to group B, newborns belonging to group A showed a significantly lower incidence of pneumonitis in the postoperative period (RR 0.31; 95% CI 0.17-0.57, p = 0.0001). However, no significant difference in the incidence of anastomotic complications including anastomotic leak (RR 0.73; 95% CI 0.48-1.12, p = 0.15) and stricture (RR 0.63; 95% CI 0.36-1.09, p = 0.10) was observed between the two groups. The average Downs and Black scale scores ranged from 20 to 24. The risk of bias was low (n = 1) and moderate (n = 5) in the included studies. Kappa statistics showed a value of 0.902 (p < 0.001), highlighting an almost perfect agreement among the two observers. The present meta-analysis revealed the superiority of surgical repair of EA-TEF performed with preservation of azygos vein in terms of the incidence of postoperative chest infection. However, no significant difference in the occurrence of anastomotic leak and stricture was observed between the two groups. The level of evidence of the published comparative studies is limited. Therefore, well designed, randomized controlled trial utilizing a standardized operative approach on a larger sample-size needs to be conducted for optimal comparison between the two approaches.

Keywords: Anastomotic leak; Azygos vein; Esophageal atresia-tracheoesophageal fistula (EA-TEF); Pneumonitis; Stricture.