Fifteen studies were included (n=1,909): three RCTs (n=454); three prospective non-randomised studies; and nine retrospective studies. Study quality scores ranged from 5 to 12. The maximum quality score was unclear and results for individual items were not presented.
Survival was improved in extended pancreaticoduodenectomy compared with pancreaticoduodenectomy, but this result was not statistically significant and there was substantial heterogeneity between studies (p=0.006). Restriction of the analysis to RCTs showed no differences in survival between the two techniques, although heterogeneity was reduced (p=0.20).
Significantly more lymph nodes were harvested from patients who underwent extended pancreaticoduodenectomy (WMD 14 nodes, 95% CI 11 to 17; seven studies) and operative time was longer (WMD 48.9 minutes, 95% CI 28.0 to 69.9; eight studies). Restriction of the analysis to RCTs supported these findings, although effects were smaller (WMD 7 nodes, 95% CI 1 to 13; three RCTs and WMD 37 minutes, 95% CI -56.8 to -17.1; three RCTs).
There was some evidence of increased delayed gastric emptying with extended pancreaticoduodenectomy (OR 0.59, 95% CI 0.36 to 0.96; six studies), but this was not found in the analysis restricted to RCTs. Perioperative adverse events and mortality were similar between the groups.