Vezakis 1999.

Methods	Randomised clinical trial.
Participants	Country: United Kingdom. Number randomised: 36. Mean age: 52 years. Females: 29 (80.6%). Inclusion criteria: Elective laparoscopic cholecystectomy ASA I or II. Exclusion criteria: Extensive upper abdominal incisions Receiving regular analgesic medication.
Interventions	Participants were randomly assigned to two groups: Group 1: abdominal wall lift (n = 18). Group 2: pneumoperitoneum with 8 mm Hg pressure (n = 18). Device used for abdominal lift: subcutaneous device.
Outcomes	The main outcome measures were operating time and hospital stay.
Notes	Two cross‐over from abdominal wall lift group: 1 because of inadequate exposure; 1 because of necessity to perform laparoscopic CBD exploration. Attempts were made to contact the author in February 2007.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomisation was performed preoperatively using envelopes with random numbers."
Allocation concealment (selection bias)	Low risk	Quote: "Randomisation was performed preoperatively using envelopes with random numbers." Comment: further details of the sealed envelope were not available.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: This information was not available.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: This information was not available.
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: There were postrandomisation drop‐outs.
Selective reporting (reporting bias)	High risk	Comment: Important outcomes were not reported.
Vested interest bias	Unclear risk	Comment: This information was not available.