Eligible studies had to compare the results of pancreatic resections with vein resection versus without vein resection for pancreatic cancer and report on at least one of the perioperative or long term outcome measures: perioperative outcomes included operative time, operative blood loss, number of patients requiring blood transfusion, morbidity and mortality. Long-term outcomes included one-, three- and five-year overall survival.
Abstracts, letters, editorials and expert opinions, reviews without original data, case reports and studies that lacked control groups were excluded. Where dual (or multiple) studies were reported by the same institution and/or authors, either the higher quality or the most recent publication was included in the analysis.
Age (most ≥60 years old) and sex (slightly more males than females) were matched in treatment and control groups. Tumour invasion was found microscopically in 279 of the 490 patients who underwent vein resection (56.9%, range 21% to 100%) and 211 had inflammatory adhesions without cancer invasion (43.1%). Study follow-up was variable; only a subset of studies presented data on five-year survival.
The authors did not report how many reviewers assessed eligibility.