Association between tumor contact surface area and parenchymal volume change in robot‐assisted laparoscopic partial nephrectomy carried out using the enucleation technique

Abstract

Objective To evaluate the change in the operated parenchymal volume during robot‐assisted partial nephrectomy limited to the enucleation technique, and to analyze the predictors of decrease in operated parenchymal volume, including the tumor contact surface area. Methods The study included 135 patients who underwent robot‐assisted partial nephrectomy for T1 renal tumors using the enucleation technique. Measurements of the parenchymal volume, tumor volume and contact surface area were obtained in the venous phase on enhanced computed tomography. All measurements, including volumetric and renal function analysis, were carried out <2 months before and 6 months after surgery. Results The mean age of included participants was 56 years, and the mean tumor size was 33 mm. The mean tumor volume was 26 cc, and the mean contact surface area was 22 cm2. In the complete cohort, the mean preoperative and postoperative normal parenchymal volumes of the operated kidney were 158 and 141 cc, respectively. The mean change in parenchymal volume of the operated kidney was −10%. In contrast, the mean change in global estimated glomerular filtration was just −4.0%. Univariate analysis showed that the RENAL nephrometry score, contact surface area, tumor volume and warm ischemia time were associated with the change in the operated kidney parenchymal volume. However, in the multivariate analysis, a large contact surface area was the only independent predictor of decreased operated parenchymal volume <10 cm3. Conclusion Contact surface area is a strong predictor of the decrease in the parenchymal volume in the operated kidney during robot‐assisted partial nephrectomy carried out using the enucleation technique for T1 renal tumors.

Limited impact of warm ischemic threshold for partial nephrectomy in the robotic surgery era: A propensity score matching study

“…27 We believe it is now meaningless to set the threshold 30 min for T1b or RENAL nephrometry score ≥9 T1b tumors if methods to minimize normal renal parenchymal loss are to be applied. 28 In contrast, when stratified by different thresholds using propensity score matching, % eGFR decline was larger for the longer WIT than the shorter WIT group, with and without significance at the 20 and 25 min thresholds, respectively (data not shown). The eGFR difference in both was approximately 1.5-1.8 mL/min/1.73 m 2 , and seemed clinically negligible.…”

Greater Renal Function Benefit from Enucleation Technique for More Complex Renal Tumors in Robot-Assisted Partial Nephrectomy

“…Large tumors tend to have larger contact surfaces on excision, which is associated with renal mass loss. 15 Moreover, according to our previous study, larger-diameter tumors (i.e., ‡30 mm) are highly likely to be surrounded by pseudocapsules. 27 In such tumors, enucleation is speculated to be easy and safe.…”

“…23 We previously reported that larger tumor contact surface area is associated with more parenchymal volume loss in RAPN. 15 As more vascularized renal parenchyma is likely to be included in tumors with high RNS (large diameter, hilar, and median polar location), a running suture for kidney reconstruction owes unavoidable risk of compromising intrarenal vascular anatomy. 24,25 Thus, it is reasonable to presume that efforts to preserve any little volume of parenchyma for these tumors are crucial to prevent acute kidney injury or CKD.…”

“…We speculate that the resection manner at the intermediate to base of the tumors, an area with more contact surface with normal renal parenchyma, is more likely to influence the surgical results. 15 This study aimed to compare the benefits of enucleation performed at the intermediate to base of the tumor based on three RNS categories (Low, Intermediate, and High).…”

Feasibility and necessity of the fourth arm of the da Vinci Si surgical system for robot‐assisted partial nephrectomy

“…In this series, we performed RAPN with the same port place at the same site. Port placement for RAPN differs depending on the institution, surgeons' preference, type of da Vinci system (Si or Xi) used, or total number of ports including those of the assistants . Compared to Caucasian patients, Asian patients are slimmer and require narrower intra‐abdominal working space in general .…”