Gu 1998 (A).

Study characteristics
Methods	Prospective study Run‐in period: from June 1995 to June 1996 Accepted for publication: 5 August 1997 Number of study centres and locations: single centre; Department of Cardiothoracic Surgery, University Hospital Groningen, the Netherlands
Participants	Sixty‐two consecutive patients were assigned randomly to two groups: 31 participants underwent minimally invasive CABG, and 31 participants underwent conventional CABG with CPB. In a subgroup of 10 participants in each group, subclinical markers were measured to determine the level of the inflammatory response generated during the operation. Mean age: 60.5 years Sex (female/male ratio): 33.87% No high‐risk patients Inclusion criteria: patients with isolated stenosis of the left anterior descending coronary artery Exclusion criteria: the presence of any associated cardiac disease, such as a left ventricular aneurysm or valvular disease
Interventions	Intervention group: without CPB through a small anterolateral thoracotomy (MICABG, a skin incision approximately 8 cm to 10 cm long was made at the level of the fifth intercostal space, with the medial edge of the incision 3 cm to 4 cm lateral to the LIMA) Control group: CPB‐CABG (a median sternotomy)
Outcomes	Haematologic and biochemical measurements (leucocyte elastase, leucocyte and Plt count, b‐Tg, and complement C3a), clinical parameters (duration of operation, blood loss, ventilatory support, postoperative hospital stay, and postoperative morbidity and mortality) Blood sample was taken during wound closure in the MICABG group and after CPB but before protamine administration in the CPB‐CABG group.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Consecutive patients were enroled, but no further randomisation method description is given: "62 consecutive patients with isolated stenosis of the left anterior descending coronary artery were assigned randomly to two groups".
Allocation concealment (selection bias)	Unclear risk	No allocation concealment information
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not specified; very unlikely for personnel and participants because of the nature of the intervention, although unclear how lack of blinding could influence outcomes
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not specified
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	In a subgroup of 10 participants in each group, subclinical markers were measured to determine the level of the inflammatory response generated during the operation. Criteria for selecting the participants in the subgroup are unclear.
Selective reporting (reporting bias)	Low risk	All expected outcomes were reported properly.
Other bias	Low risk	No funding was disclosed.