Impact of Positive Surgical Margins After Partial Nephrectomy

Abstract

The impact of positive surgical margins (PSMs) after partial nephrectomy (PN) is controversial. To evaluate the risk factors for a PSM and its impact on overall survival. This is a retrospective study of 388 patients were submitted to PN between November 2005 and December 2016 in a single centre. Two groups were created: PSM and negative surgical margin (NSM) after PN. A p value of <0.05 was considered significant. Relationships with outcome were assessed using univariable and multivariable tests and log-rank analysis. The PSM rate was 3.8% (N = 16). The mean age at the time of surgery (PSM group: 64.1 ± 11.3 vs NSM group: 61.8 ± 12.8 yr, p = 0.5) and the mean radiological tumour size (4.0 ± 1.5 vs 3.4 ± 1.8 cm, p = 0.2) were similar. Lesion location (p = 0.3), surgical approach (p = 0.4), warm ischaemia time (p = 0.9), and surgery time (p = 0.06) had no association with PSM. However, higher surgeon experience was associated with a lower PSM incidence (2.6% if ≥30 PNs vs 9.6% if <30 PNs; p = 0.02). Higher operative blood loss (p = 0.02), higher-risk tumours (p = 0.03), and larger pathological size (p = 0.05) were associated with an increase in PSM. In the PSM group, recurrence rate (18.7% vs 4.2%, p = 0.007) and secondary total nephrectomy rate (25% vs 4.4%, p < 0.001) were higher. However, overall survival was similar. Multivariate analysis revealed that high-risk tumour (p = 0.05) and low experience (p = 0.03) could predict a PSM. Limitations include retrospective design and reduced follow-up time. PSMs were mainly associated with high-risk pathological tumour (p = 0.05) and low-volume surgeon experience. Recurrence rate and need for total nephrectomy were higher in that group, but no impact on survival was noticed. The impact of positive surgical margins (PSMs) after partial nephrectomy is a matter of debate. In this study, we found that PSMs were mainly associated with aggressive disease and low surgeon experience.