Ribeiro 2012.

Methods	‐Country: Brazil ‐Setting: university hospital ‐Study design: RCT
Participants	‐No. of participants randomised: 83 ‐Age (mean): 6 years (72 months) in the subclavian Seldinger group and 7 years (82 months) in the internal jugular Seldinger group ‐Gender: 58% males, 42% females ‐Exclusions post randomisation: If the initial attempt in the randomised site was unsuccessful, the surgeon would proceed to a new attempt at the other puncture site. In cases where this second route was also unsuccessful, children were excluded from the long‐term analysis ‐Inclusion criteria: Paediatric oncology patients ‐Exclusion criteria: Patients weighing less than 6 kg had their catheters preferentially implanted by the venous dissection technique and were excluded from the study
Interventions	A total of 83 children were included in the study; 44 were initially randomised to TIVAP implantation in the subclavian vein and 39 to the internal jugular vein. Six children were excluded from the study because implantation by puncture failed in both sites. Patients for TIVAP implantation were under general anaesthesia. Routine antibiotic prophylaxis was administered. The Seldinger technique internal jugular vein and subclavian vein punctures were performed without use of ultrasound. In all cases, implantation was preferentially performed on the child's right side. Chest radiograph was performed to confirm catheter position
Outcomes	Sucess rates, early (within 1 week) and late complication, were recorded
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Randomisation (using a coin; heads or tails) was employed
Allocation concealment (selection bias)	High risk	Not specified, but it seems likely that the coin tossing happened immediately before surgery, which implies that there was no allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	Low risk	No blinding of either participants or personnel mentioned in the methodology. Comment: Blinding of personnel carrying out the procedure is not feasible for this procedure. Blinding of participants, however, is practically feasible. Nevertheless, it is unlikely the blinding of the personnel and participants would have affected the outcomes of the study. We judged performance bias as low risk of bias
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not specified
Incomplete outcome data (attrition bias) All outcomes	High risk	If the initial attempt in the randomised site was unsuccessful, the surgeon would proceed to a new attempt at the other puncture site. In cases where this second route was also unsuccessful, children were excluded from the long‐term analysis
Selective reporting (reporting bias)	Unclear risk	All endpoints mentioned in methods section are reported
Other bias	Unclear risk	Conflict of interest: nothing to declare Funding source not reported

BMI: body mass index
 ECG: electrocardiogram
 ITT: intention to treat
 RCT: randomised controlled trial
 TIVAP: totally implantable venous access ports
 US: ultrasound