Impact of intra-pyloric botulinum toxin injection on delayed gastric emptying following esophagectomy: systematic review and meta-analysis

Background: The value of pyloric interventions during esophagectomy remains controversial. Injecting botulinum toxin -A (BT -A) into the pylorus is proposed to reduce delayed gastric emptying by inhibiting the pyloric muscle. Methods: We performed a systematic review and meta -analysis, searching in MEDLINE, EMBASE and Cochrane -collaboration databases to identify studies comparing intra-operative pyloric BT -A injection with no intervention during esophagectomy for cancer. We assessed rates of delayed gastric emptying, postoperative pyloric endoscopic balloon dilatations, anastomotic leaks, respiratory complications and mortality. Results: Among 103 potentially relevant studies, 7 cohort studies (n=781 patients) met the inclusion criteria. Comparing BT -A use to no pyloric intervention, the pooled odds ratio (OR) was 0.59 [95% confidence interval (CI): 0.24-1.47; P=0.26] for post -operative delayed gastric emptying, 1.75 (95% CI: 0.68-4.48; P=0.24) for endoscopic balloon dilatations, 1.01 (95% CI: 0.54-1.87; P=0.98) for anastomotic leak, 0.60 (95% CI: 0.33-1.09; P=0.10) for respiratory complications and 1.11 (95% CI: 0.39-3.18; P=0.85) for mortality. Conclusions: Meta -analysis of currently available data suggests BT -A use results in no significant impact on rates of delayed gastric emptying, requirement for endoscopic balloon dilatation, anastomotic leaks, respiratory complications or mortality. The use of BT -A and other pyloric interventions should be the subject of larger randomised trials. Currently, the heterogeneity of data available for meta -analysis and lack of consistent definitions precludes routine use of pyloric interventions.