Boccardo 2009.

Methods	Single centre randomised controlled trial
Participants	55 women scheduled to undergo breast conserving surgery or radical mastectomy and axillary clearance for breast cancer. 6 women dropped out after randomisation. Intervention group: n = 25. Comparison group: n = 24. Age of participants 54.07 ± 10.54 (mean ± SD).
Interventions	Intervention: lymphaticovenular anastomosis was performed to prevent lymphoedema formation either during primary operation if lymphatic impairment was identified in preoperative lymphoscintigraphy or later if physical treatment failed in preventing lymphoedema development and lymphoscintigraphy done at 6 months revealed impairment in lymph flow. Comparator: no preventive strategies were used.
Outcomes	Lymphoedema was defined as arm volume increase of 200 mL from baseline. Percentage of arm volume increase was also reported. Reported at 1, 3, 6, 12, and 24 months.
Notes	Setting: S.Martino Hospital, Genoa, Italy
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not stated
Allocation concealment (selection bias)	Unclear risk	Not stated
Blinding of participants and personnel (performance bias) All outcomes	High risk	Unable to blind either surgeons or participants
Blinding of outcome assessment (detection bias) All outcomes	High risk	Regardless of who assessed outcomes, it would be very difficult to blind outcome assessment because of participant's knowledge and the presence of surgical scars.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	89% of participants were assessed at 2 years. 6 participants did not finish follow‐up to 24 months. No reasons mentioned
Selective reporting (reporting bias)	Low risk	Outcomes reported as described in methods section
Other bias	Low risk	Study appeared to be free of other sources of bias