Robot‐assisted partial nephrectomy: continued refinement of outcomes beyond the initial learning curve

Objectives To evaluate trends in peri‐operative outcomes of 250 consecutive cases beyond the initial learning curve (LC) of robot‐assisted partial nephrectomy (RAPN) among multiple surgeons. Patients and Methods A multi‐institutional database was used to evaluate trends in patient demographics (e.g. age, gender, comorbidities), tumour characteristics (e.g. size, complexity) and peri‐operative outcomes (e.g. warm ischaemia time [WIT], operating time, complications, estimated blood loss [EBL], trifecta achievement) in consecutive cases 50–300 (n = 960) from 2008 to 2016 among four experienced surgeons. Trends in outcomes were assessed using multivariable regression models adjusted for demographic and tumour‐specific variables. Outcomes for cases 50–99 were compared with those for cases 250–300. Results In the study period RAPN was increasingly performed in patients with larger tumours (β = 0.001, P = 0.048), hypertension (odds ratio [OR] 1.003; P = 0.008) diabetes (OR 1.003; P = 0.025) and previous abdominal surgery (OR 1.003; P = 0.006). Surgeon experience was associated with more trifecta achievement (OR 1.006; P < 0.001), shorter WIT (β = −0.036, P < 0.001), less EBL (β = −0.154, P = 0.009), fewer blood transfusions (OR 0.989, P = 0.024) and a reduced length of hospital stay (β = −0.002, P = 0.002), but not with operating time (P = 0.243), complications (P = 0.587) or surgical margin status (P = 0.102). Tumour size and WIT in cases 50–99 vs 250–300 were 2.7 vs 3.2 cm (P = 0.001) and 21.4 vs 16.2 min (P < 0.001), respectively. Conclusion Refinement of RAPN outcomes, concomitant with the treatment of a patient population with larger tumours and more comorbidities, occurs after the initial LC is reached. Although RAPN can consistently be performed safely with acceptable outcomes after a small number of cases, improvement in trifecta achievement, WIT, EBL, blood transfusions and a shorter hospitalization continues to occur up to 300 procedures.