Buchler 1995.

Methods	Randomised controlled trial
Participants	Country: Germany Number randomised: 48 Post‐randomisation drop‐outs: 8 (16.7%) Revised sample size: 40 Mean age (years): 45 Women: 4 (10%) Follow‐up period (years): 14 Number of study centres: 1 Inclusion criteria People were enrolled in the study when they presented with pancreatic head enlargement defined as a diameter of > 4 cm in contrast‐enhanced CT scan Obstruction of the common bile or pancreatic duct or duodenum Entrapment of the retroperitoneal portal vein or superior mesenteric artery General condition suitable for either a DPPHR or a Whipple procedure
Interventions	Participants were randomly assigned to 1 of 2 groups Group 1: duodenum‐preserving pancreatoduodenectomy (n = 20) (23 participants were randomised) Further details: Beger procedure Group 2: pancreatoduodenectomy (n = 20) (25 participants were randomised) Further details: Whipple procedure
Outcomes	Mortality, post‐operative complications, quality of life, length of hospital stay, proportion of people employed, diabetes, and exocrine insufficiency
Notes	Reasons for post‐randomisation drop‐outs: pancreatic cancer (n = 1), did not require pancreatic head resection (n = 7)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: this information was not available
Allocation concealment (selection bias)	Unclear risk	Comment: this information was not available
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Comment: information on participant blinding was not available. It is impossible to blind surgeons who perform the procedure
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: this information was not available
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: no participants were lost to follow‐up, although some participants were excluded from analysis (see other bias)
Selective reporting (reporting bias)	Low risk	Comment: all important outcomes were reported
Other bias	High risk	Comment: 1 participant had pancreatic cancer intra‐operatively and underwent Whipple procedure. The group to which this participant was randomised was not stated. 7 other participants were excluded from the analysis since they did not require pancreatic head resection. All the participants were symptomatic. Therefore, the reason for abandoning surgeries was not clear