Tumor Enucleation: Functional Comparison with Standard Partial Nephrectomy
Tumor enucleation (TE) optimizes parenchymal preservation and could yield better function than standard partial nephrectomy (SPN). However, data about this are controversial. Our study compares functional outcomes for TE and SPN strategies.
Patients managed with partial nephrectomy (PN) with necessary data for analysis of preservation of ipsilateral parenchymal mass and global GFR from two centers were included. All studies were required <2 months prior and 3-12 months after surgery. Patients with solitary kidney or multifocal tumors were excluded. Ipsilateral vascularized parenchymal mass was estimated from contrast-enhanced CT scans preoperatively and postoperatively. Serum creatinine-based estimates of global GFR were also obtained in the same timeframes. Univariable and multivariable linear regression evaluated factors associated with new baseline global GFR.</p>
Analysis included 71 TE and 373 SPN. Median preoperative global GFR was comparable for TE and SPN (75mL/min/1.73m2 versus 78mL/min/1.73m2, p=0.6). Median tumor size was 3.0cm for TE and 3.3cm for SPN (p=0.03). Median R.E.N.A.L scores were 7 in both cohorts. For TE, warm and zero ischemia were used in 51% and 49%, respectively. For SPN, warm and cold ischemia were used in 72% and 28%, respectively. Capsular closure was performed in 46% of TE and 100% of SPN (p<0.001). Positive margins were found in 8.5% of TE and 4.8% of SPN (p=0.2). Median ipsilateral vascularized parenchymal mass preserved was 95% (IQR=91-100) for TE and 84% (IQR=76-92) for SPN (p<0.001). Median global GFR preserved was 101% (IQR=93-111) and 89% (IQR=81-96) for TE and SPN, respectively (p<0.001). On multivariable analysis, resection strategy, preoperative GFR, and vascularized parenchymal mass preserved all associated significantly with new baseline global GFR (all p<0.001). Limitations include retrospective design and lack of resection outcome data.</p>
Our analysis suggests that TE has potential to maximally preserve parenchymal mass compared to SPN and may provide optimized functional recovery. Further investigation will be required to evaluate the clinical significance of these findings.