E DOWNIE1, A MAKRIS1,2, G NARAYANAN1, A ARAVINDAN1, S SPICER1, H NANDAKOBAN1,3, K MAC1,2, J WONG1
1Liverpool Hospital, 2Medicine Faculty, Western Sydney Univerisity, 3South West Sydney Clinical School, UNSW
Aim: Compare the needle-guide (NG) and freehand (FH) techniques for teaching ultrasound guided percutaneous renal biopsy (PRB).
Background: Safety and success are key factors in PRB. NGs allow alignment of the needle and needle path prediction, whereas FH allows the ultrasound probe and needle to move independently. There is no evidence comparing the two techniques in teaching PRB.
Methods: We conducted a single-centre prospective, randomised controlled trial of junior medical staff randomised to FH or NG, stratified by gender, medical seniority, ultrasound experience and dominant hand. Participants underwent standardised education, and then performed PRB on a synthetic model. Assessors and participants completed an assessment of the difficulty of the procedure. The primary outcome was a composite of safety and adequacy of the procedure. Secondary outcomes included proportion of inferior pole biopsies, needle visualisation, adequacy of kidney biopsy, time taken and participant and assessors assessment. The trial was registered (ACTRN12620000132943p) and analysis undertaken with SPSS.
Results: After randomisation (n=91), using a hierarchical conditional backward logistic regression model, use of a needle-guide increased the likelihood of the primary outcome adjustedOR 3.2(95%CI 1.1-9.6;p=0.036) as did ultrasound experience adjOR3.1(95%CI1.0-9.5;p=0.049) and male gender adjOR4.4(95%CI1.5-12.9;p=0.007). Procedure time was shorter in the NG group (p=0.01). In each attempt, NG was associated with a higher rate of adequate needle visualisation (p<0.05).
Conclusions: Whilst learning PRB, needle-guide use, ultrasound experience and male sex are associated with safe and adequate biopsies. The use of NG was associated with a shorter procedural time and an increased rate of adequate needle visualisation.
Dr Elizabeth Downie is an advanced trainee in nephrology based at Liverpool Hospital. She completed basic physicians training between Royal Darwin Hospital and Wollongong Hospital. She has interests in chronic kidney disease, dialysis and medical education.