Robot-assisted Partial Nephrectomy Research Articles

Comparison of In-Hospital Outcomes at Robot-Assisted Versus Open Partial Nephrectomy.

The aim of this work is to quantify the magnitude of improvement in in-hospital outcomes between historical and contemporary robot-assisted partial nephrectomy (RPN) versus historical and contemporary open PN (OPN). Within the Nationwide Inpatient Sample (2010-2019), we identified patients who underwent RPN and OPN. Multivariable logistic regression models were fit. Historical (2010-2014) versus contemporary (2015-2019) proportions were 39% (n = 5,897) versus 61% (n = 9168) for RPN and 59% (n = 7289) versus 41% (n = 5,120) for OPN. Relative to historical, contemporary RPN patients exhibited significantly better in-hospital outcomes in 6 of 12 categories that ranged from-76% for intraoperative complications to-24% for length of stay (LOS) ≥ 75th percentile. Relative to historical, contemporary OPN patients also exhibited significantly better in-hospital outcomes in 7 of 12 categories that ranged from-76% for intraoperative complications to-23% for LOS ≥ 75th percentile. When historical RPN was compared with historical OPN, RPN in-hospital outcomes were better in 10 of 12 comparisons that ranged from-75% for LOS ≥ 75th percentile to-28% for perioperative bleeding. Similarly, when contemporary RPN was compared with contemporary OPN, RPN outcomes were better in 8 of 12 comparisons that ranged from-75% for LOS ≥ 75th percentile to-27% for postoperative complications. The magnitude of improvement in in-hospital outcomes was more pronounced for contemporary versus historical OPN (seven improved categories) than for contemporary versus historical RPN (six improved categories). However, contemporary RPN outperformed contemporary OPN patients in eight in-hospital outcome categories.

Environmental Impact of Minimally Invasive Radical and Partial Nephrectomy: A Multicenter Prospective Comparative Study Comparing Robot-Assisted and Laparoscopic Surgical Approaches

Background: Minimally invasive surgery has improved patient outcomes but raises environmental concerns due to carbon emissions from disposable instruments, energy consumption, and hospital resource use. This study evaluates the carbon footprint of robot-assisted and laparoscopic nephrectomies. Methods: A multicenter prospective study analyzed 162 patients undergoing robot-assisted or laparoscopic partial (RAPN, LPN) and radical nephrectomy (RARN, LRN). Life cycle assessment (LCA) quantified CO2 emissions from instrument use, sterilization, and energy consumption. Results: Robot-assisted procedures had lower CO2 emissions than laparoscopic approaches. Emissions from instrument disposal were 9.04 kg in RAPN vs. 12.14 kg in LPN (p = 0.02) and 8.74 kg in RARN vs. 11.45 kg in LRN (p = 0.03). Despite higher intraoperative energy use, robot-assisted surgery produced 3–4 kg less CO2 per procedure due to reusable instruments and shorter hospitalization. Conclusions: Robot-assisted nephrectomy reduces environmental impact by minimizing waste and hospital stays. Efforts should focus on reusable instruments, energy efficiency, and sustainability initiatives to mitigate surgical carbon footprints while ensuring high-quality care.

Role of three-dimensional modelling and augmented reality during robotic-assisted partial nephrectomies

Role of three-dimensional modelling and augmented reality during robotic-assisted partial nephrectomies

A comparative analysis of perioperative outcomes in single-port and multi-port retroperitoneal robot-assisted partial nephrectomy: a systematic review and meta-analysis.

The retroperitoneal approach for RAPN minimizes interference with intraperitoneal organs but is constrained by a restricted operating space. The single-port (SP) robotic platform excels in navigating tight anatomical environments compared to the multi-port (MP) robotic system. However, there are not many studies that compare the results of surgery using these two platforms when the retroperitoneal approach is used. To address this difference, a detailed review of current studies was done to compare the results of SP-RAPN and MP-RAPN surgeries that were performed using the retroperitoneal method. A comprehensive search was conducted in the databases of PubMed, Web of Science, the Cochrane Library, and SpringerLink to identify any studies that compare urgent-start PD versus urgent-start HD prior to November 25th, 2024. To compare SP-RAPN to MP-RAPN, we looked at things like operation duration, expected blood loss, length of stay, ischemia time, all complications, PSMs, and pathological stage. This meta-analysis incorporated four studies involving a total of 728 patients. Our findings showed no notable distinctions in operative time (WMD -4.75min, 95% CI -12.05 to 2.55, p = 0.20), ischemia time (WMD 3.01min, 95%CI -1.32 to 7.34, p = 0.17), blood loss (WMD -3.53ml, 95% CI -18.01 to 10.95, p = 0.63), hospital stay duration (WMD -0.23days, 95% CI -0.69 to 0.23, p = 0.32), or overall complication rates (OR 0.34, 95%CI 0.11 to 1.04, p = 0.06) between SP-RAPN and MP-RAPN. Additionally, there was no significant variation in the incidence of positive surgical margins (OR 0.74, 95%CI 0.33 to 1.65, p = 0.46) or in the distribution of postoperative pathological stages, including pT1a (OR 1.22, 95%CI 0.81 to 1.82, p = 0.35), pT1b (OR 0.65, 95%CI 0.39 to 1.06, p = 0.08), and stages ≥ pT2 (OR 1.13, 95%CI 0.54 to 2.38, p = 0.75). While single-port robotic systems provide notable operational advantages in confined spaces, our meta-analysis shows no significant differences between SP-RAPN and MP-RAPN in terms of operative time, intraoperative blood loss, hospital stay, ischemia time, complication rates, and positive surgical margins when both techniques are used for retroperitoneal resection of non-complex renal tumors. Future large-scale randomized controlled trials are required for long-term follow-up to further validate these findings.

Association Between Early Recovery of Renal Function and Residual Renal Function After Robot-assisted Partial Nephrectomy.

This study aimed to explore factors related to residual renal function in patients with small renal tumors treated with robot-assisted partial nephrectomy. This retrospective study included 188 patients with two functioning kidneys who were diagnosed with localized renal tumors and underwent robot-assisted partial nephrectomy using the clamping technique. The residual renal function 12 months after the surgery was evaluated in two ways: >90% preservation of the estimated glomerular filtration rate and no stage progression of chronic kidney disease. The median age, body mass index, and warm ischemic time were 68 years, 23.3 kg/m2, and 19 min, respectively. Ten patients were diagnosed with positive surgical margins. Multivariate analysis revealed no significant preoperative factors, including renal function. Among surgical factors, warm ischemic time was an independent factor for chronic kidney disease progression, whereas it showed no significant association with the preservation of residual renal function (p =0.042 and p=0.14, respectively). Early recovery, defined as the difference in estimated glomerular filtration rate before and three months post-surgery, independently correlated with poor residual renal function preservation and chronic kidney disease progression (p<0.0001 and p<0.0001, respectively). Furthermore, no significant difference was observed in residual renal function recovery between warm ischemic time <25 and ≥25 min (p=0.58). Early recovery from residual renal function was crucial for preserving residual renal function and preventing chronic kidney disease progression after surgery. Understanding the factors influencing residual renal function preservation might lead to the optimization of treatment strategies in current clinical practice.

Use of Interactive Three-dimensional Models in Partial Nephrectomy: For, but Critical Evaluation Is Key.

Use of Interactive Three-dimensional Models in Partial Nephrectomy: For, but Critical Evaluation Is Key.

Use of Radiofrequency in Robot-Assisted Partial Nephrectomy for Small Tumors: A Novel Technique

Introduction and Objectives: Radiofrequency is standardized for ablating small renal tumors, but evidence regarding its effects remains limited. Partial nephrectomy, the gold standard, often leads to hemorrhagic complications and irreversible renal damage due to hilum clamping. To mitigate these risks, we propose a novel technique that replaces clamping with radiofrequency ablation of the tumor for hemostasis in robot-assisted partial nephrectomy. Methods: We report on 357 consecutive patients with T1a renal tumors treated with robot-assisted surgery between 2010 and July 2024. Radiofrequency was used peri-tumorally for hemostasis, followed by complete lesion enucleation. Follow-up included ultrasound and creatinine at 1 month, CT scans at months 3 and 9, and then annually for 5 years. Results: The median age was 60.2 years, with 251 men (70.3%). The median tumor size was 22 mm, and the median blood loss was 15 mL. Hemorrhagic complications occurred in eight patients (2.2%), with one requiring a blood transfusion (0.28%). A total of 30 patients experienced transient stage 1 acute kidney disease (8.4%), with no significant change in median 74.92 mL/min/1.77 m2 vs. 78.77 mL/min/1.77 m2 vs. (p-value 0.15). The median follow-up was 48.2 months, with no tumor recurrence at the treated site. Renal cell carcinoma was found in 83.7% of tumors. Conclusions: To our knowledge, this series represent the largest global undertaking of renal tumor treatment using peripheral radiofrequency ablation without clamping, demonstrating optimal surgical and oncological outcomes, lower morbidity, and fewer complications compared to those noted in the revised literature regarding traditional clamping techniques.

Comparisons of Efficiency, Safety, and Hospital Costs of Four-Arm Robotic-Assisted Partial Nephrectomy (RAPN) Versus Three-Arm Technique: A Propensity Score-Matched Analysis.

Objectives: The advent of robotic-assisted partial nephrectomy (RAPN) has marked a new era in minimally invasive surgery, establishing itself as a preferred method for managing renal cell carcinoma (RCC). However, even within the same center, variations in the use of robotic arms during RAPN have been reported. In this study, we aim to explore differences in efficiency, safety, and hospital costs between three-arm and four-arm RAPN. Methods: This retrospective study analyzed the clinical data of 91 patients who underwent RAPN in Tongji Hospital from January 2021 to December 2023. The patients were divided into two groups: 50 patients in the three-arm group (with the use of three robotic arms and two assistant ports) and 41 patients in the four-arm group (with the use of four robotic arms and one assistant port). Patients' demographics and tumor characteristics, operative outcomes, and hospital costs were recorded. Propensity score matching (1:1) was performed on age, gender, body mass index, laterality, RENAL score, tumor stage, and pathological grade. We compared three-arm with four-arm RAPN groups based on operative outcomes, and hospital costs. Results: In total, 50 and 41 patients underwent three-arm and four-arm RAPN. All procedures were successfully executed without the need to convert to open surgery or radical nephrectomy. After matching, the four-arm configuration demonstrated a numerically longer total operative time compared with the three-arm approach (146.5 vs. 120.0 min, p = 0.068). Hospital costs in the four-arm group were significantly higher than those in the three-arm group (76,922.5 vs. 68,406.7 CNY, p = 0.006). Conclusions: Both the three-arm and four-arm robotic approaches demonstrated comparable safety and efficacy in RAPN procedures. Nevertheless, the four-arm approach is associated with elevated hospital costs. The preliminary findings suggest potential cost containment disadvantages for the four-arm technique in selected cases, though larger multicenter studies are essential.

A Single Port (SP) Approach Reduces the Risk of Postoperative Complications in Elderly Patients Undergoing Robotic-Assisted Partial Nephrectomy (RAPN).

In recent years, due to the increasing life expectancy and the growing popularity of nephron sparing strategies (NSS), more elderly and frail patients are undergoing Robotic-Assisted Partial Nephrectomy (RAPN) for the treatment of localized Renal Cell Carcinoma (RCC). A Single Port Approach has demonstrated itself to reduce estimated blood loss (EBL), complication rates, and length of stay (LOS). In the present study, we aim to compare perioperative and postoperative outcomes of SP RAPN and Multi Port (MP) RAPN, with a focus on elderly patients. In the study, 293 cN0M0 RCC patients who underwent MP and SP RAPN performed at our institution from 2018 to 2024 were retrospectively reviewed. Clinical, demographic, patient, and tumor characteristics and perioperative variables were assessed across group A (<65 years old) and group B (≥65 years old) patients, as well as MP and SP cohorts. Subsequently, univariate and multivariate regression analyses were carried out, particularly for elderly patients, to evaluate the impact of selected preoperative and perioperative variables on the risk of 30-day postoperative complications. Clinical and demographic characteristics were similar across the MP and SP cohorts of group A and group B. The SP cohort of both group A and group B demonstrated significantly higher rates of extraperitoneal access (75.9% vs. 26.6% for group A, p < 0.001 and 81.8% vs. 26.2% for group B, p < 0.001), shorter median operative times (186 [142.8-222] min vs. 190 [153-238] min for group A, p < 0.001 and 173.5 [143-228] min vs. 206 [178-237] min for group B, p < 0.001), and shorter median LOS (0 [0-1] days vs. 2 [1-3] days for group A, p < 0.001 and 0 [0,1] days vs. 2 [2-4] days for group B, p < 0.001). Moreover, for both groups, an SP approach required significantly longer median ischemia times (21 min [18-31] vs. 20 min [16-24] for group A, p = 0.02 and 24.5 min [20-28] vs. 19.5 min [16-26] for group B, p = 0.03). However, the SP cohort of group B, despite the lower rate of on-clamp procedures (63.4% vs. 90.5%, p = 0.03), demonstrated significantly lower median EBL (50 mL [31-142] vs. 100 mL [50-200], p = 0.03). At multivariate analysis, the SP approach was an independent predictor of lower 30-day postoperative complications (OR: 0.2, 95%CI 0.04-0.9, p = 0.04). In the present study, elderly patients undergoing SP RAPN did not demonstrate higher complication rates, EBL or hospitalization days compared to their younger counterparts. Moreover, an SP approach was found protective for 30-day postoperative complications. Our results suggest that SP RAPN is feasible and safe in older and frailer patients.

Robot-assisted partial nephrectomy for technically challenging renal tumors (completely endophytic and hilar): a systematic review and meta-analysis of perioperative, oncological, and functional outcomes.

Robot-assisted partial nephrectomy (RAPN) has emerged as a surgical option for renal tumors. This study aimed to compare perioperative, functional, and oncological outcomes of RAPN between completely endophytic and hilar renal tumors versus non-completely endophytic and non-hilar tumors.Following PRISMA guidelines, we conducted a comprehensive search of PubMed, Embase, Web of Science, and Cochrane Library databases. We included studies comparing outcomes between completely endophytic and hilar tumors versus non-completely endophytic and non-hilar tumors treated with RAPN. The study protocol was registered with PROSPERO (ID: CRD42024628029).The analysis included thirteen studies with 8572 patients. Compared to non-completely endophytic and non-hilar tumors, the complex tumor group demonstrated significantly increased operative time (Mean Difference [MD]: 13.79 min; 95% CI: 5.12-22.45; p = 0.002), higher blood loss (MD: 23.73 mL; 95% CI: 4.15-43.30; p = 0.02), greater decline in estimated glomerular filtration rate (eGFR) (MD: 2.19 ml/min/1.73 m2; 95% CI: 0.59-3.78; p = 0.007), and higher rates of major complications (OR: 1.57; 95% CI: 1.15-2.13; p = 0.004). Length of hospital stay, positive surgical margins, and local recurrence rates showed no significant differences between groups.RAPN for completely endophytic and hilar renal tumors demonstrates comparable oncological outcomes to non-completely endophytic and non-hilar tumors, despite increased operative time, blood loss, eGFR decline, and major complication rates. However, future prospective, randomized studies with longer follow-up periods are needed to validate these findings and better define optimal patient selection criteria.

Intraindividual perception of open vs. robot-assisted partial nephrectomy (PERCEPTION trial): An important complementing perspective to randomized controlled trials

Introduction Randomized controlled trials comparing patients’ experience with open (OPN) vs. robot-assisted partial nephrectomy (RAPN) showed no clear advantages for RAPN. This contradicts our clinical impression, so we analyzed a cohort that underwent both approaches for bilateral renal tumors. The aim of our study was to compare their intraindividual perceptions of OPN and RAPN. Methods Scar assessment and evaluation of patient-reported outcome measures (PROMs) were conducted. The questionnaires were retrospectively answered for postoperative day 5 after OPN and RAPN and, as a reference, for the date of presentation. Results Results revealed longer hospitalization and ischemia times in patients with OPN, while ratings for physical condition and quality of life were better in the RAPN group. Stress, depression, and anxiety in cancer patients scored higher in the OPN group. Scar assessment revealed less patient-reported satisfaction after OPN. Patients favored RAPN when comparing both approaches directly and were strongly favored recommending RAPN to a friend. Conclusion This is the first study on the intraindividual perception of OPN vs. RAPN, revealing a comparative judgment clearly in favor of RAPN. Based on our findings, we designed the APPROACH trial to compare OPN and RAPN in a representative population under the conditions of routine care.

Robot-assisted partial nephrectomy and robot-assisted radical prostatectomy using the Chinese surgical systems KangDuo-SR-2000 and EDGE MP1000 versus the Da Vinci Xi system: a prospective, single-center, non-randomized clinical trial.

This study aims to compare the safety and efficacy of robot-assisted partial nephrectomy (RAPN) and robot-assisted radical prostatectomy (RARP) using the Chinese surgical systems KangDuo-SR-2000 (KD-SR-2000) and EDGE MP1000 (MP1000) versus the Da Vinci Xi (DV-Xi) system, to explore viable alternative options to DV-Xi. This prospective, single-center, non-randomized clinical trial enrolled 261 patients who underwent RAPN or RARP from August 2023 to June 2024. All surgeries were performed by 3 surgeons. For RAPN, the primary outcome included surgical success, positive surgical margin (PSM), warm ischemia time (WIT) and conversion to open or laparoscopic surgery. The secondary outcome was estimated glomerular filtration rate (eGFR). For RARP, the primary outcome was surgical success without conversion to open or laparoscopic surgery, and the secondary outcomes included PSM and urinary continence recovery at 4 weeks post-catheter removal. Baseline demographics were comparable across the KD-SR-2000 group (n = 88), EDGE MP1000 group (n = 59) and DV-Xi group (n = 114). No significant differences observed in primary and secondary outcomes. However, operation time and suture time per stitch were longer in Chinese surgical systems for both RAPN and RARP compared to DV-Xi, and estimated blood loss (EBL) is higher in RAPN. Subgroup analyses indicated that performance differences were primarily attributed to the KD-SR-2000, with no significant differences observed between the MP1000 and DV-Xi. No severe complications (Clavien-Dindo grade ≥ 3) reported in any group. Chinese surgical systems provide a viable alternative, demonstrating non-inferiority compared to DV-Xi. ChiCTR2300074914; Registration Date: 2023-08-21.

Validation of a Pulsatile Model for Laparoscopic Partial Nephrectomy: NEFPAR Model.

Background: Laparoscopic and robotic-assisted partial nephrectomy are the gold standard for treating small renal tumors. To improve training while adhering to animal welfare regulations, the NEFPAR pulsatile model was developed as a nonliving alternative for surgical simulation. This study aimed to validate NEFPAR as a realistic and effective training tool. Methods: The NEFPAR model was constructed using porcine tissue used in other simulations, a pulsatile pump, and standard laparoscopic instruments. Eleven participants (4 urologists and 7 urology residents) were recruited for validation. They performed simulated laparoscopic partial nephrectomies using the model, and their performance was evaluated through a survey assessing the realism, educational impact, and comparison to other simulation models. Data were analyzed using Fisher's exact test, with significance set at P < .05. Results: Most participants (72.7%) rated the NEFPAR model as realistic for key procedural steps, such as tumor resection and renal hilum dissection. The bleeding component was deemed essential for learning by 100% of participants. The NEFPAR model was superior to nonpulsatile animal models in replicating surgical bleeding and was comparable to cadaveric models in external appearance and tissue texture. However, cadaveric models were rated higher for replicating all procedural steps. No significant differences in responses were found between urologists and residents. Conclusions: The NEFPAR model effectively simulates key aspects of laparoscopic partial nephrectomy and offers an ethical, cost-effective alternative for surgical training. It was well-received for its educational value, especially for simulating surgical bleeding. Further refinements could enhance tissue consistency and tumor positioning, but the model has strong potential to be integrated into urology training programs to improve surgical skills and reduce reliance on animal models.

Total hospital cost of robot-assisted approach in major urological cancer surgeries.

The aim of this study was to test for differences in total hospital cost (THC) between robot-assisted vs. open partial nephrectomy (PN), radical cystectomy (RC), radical prostatectomy (RP) and radical nephroureterectomy (NU). Within the National Inpatient Sample (2010-2019), we identified all robot-assisted vs. open PN, RC, RP and NU patients. Multivariable Poisson regression models were fitted. Of all surgeries, 22,572 (56%) were robot-assisted PN (RPN), 5114 (24%) were robot-assisted RC (RARC), 99,134 (70%) were robot-assisted RP (RARP), and 1138 (24%) patients were robot-assisted NU (RNU). Relative to open surgery, RARC (115,511 vs. 103,531$), RNU (64,761 vs. 54,768$), RARP (49,629 vs. 40,850$) and RPN (56,288 vs. 50,875$) were associated with higher THC (all P<0.001). After multivariable adjustment, RARP (risk ratio [RR]: 1.25), RNU (RR: 1.13), RPN (RR: 1.11) as well as RARC (RR: 1.10) independently predicted higher THC (all P<0.001). Additionally, Charlson Comorbidity Index ≥2 (RR: from 1.07 to 1.08), large bed size hospitals (RR: from 1.03 to 1.08), length of stay (RR: from 1.02 to 1.06), and overall complications (RR: from 1.09 to 1.19) invariably predicted higher THC. THC is invariably higher when robot-assisted approach is applied instead of open approach in PN, RC, RP and NU patients. This THC disadvantage of robot-assisted approach requires consideration in the light of other benefits of robot-assisted surgery that could not be addressed in the current analyses.

Open versus robotic-assisted partial nephrectomy in patients with intermediate/high-complexity kidney tumours: final results of the randomised, controlled, open-label, multicentre trial OpeRa.

Open versus robotic-assisted partial nephrectomy in patients with intermediate/high-complexity kidney tumours: final results of the randomised, controlled, open-label, multicentre trial OpeRa.

Robot-assisted partial nephrectomy vs. percutaneous cryoablation for T1a renal tumors: a single-center retrospective analysis of outcomes and costs.

The aim of this study is to compare perioperative, functional, and oncological outcomes between robot-assisted partial nephrectomy (RAPN) and cryoablation (CRYO), based on a 3-year experience at our Institution. Additionally, a secondary aim is to conduct a comparative cost analysis between the two procedures. A retrospective analysis was conducted, including patients who underwent RAPN or CRYO between January 2020 and December 2023. Group 1 consisted of 59 patients who underwent RAPN, while Group 2 included 38 patients who had CRYO. The evaluation parameters included baseline characteristics, perioperative, functional, and oncological outcomes, as well as total hospitalization costs. Operative time (OT), average length of hospital stay (LOS), and emetic blood loss (EBL) were significantly lower in the CRYO group. Furthermore, CRYO showed a significantly lower rate of postoperative complications of any grade (7.8% vs 16.9%); however, this was associated with a considerably higher recurrence rate (5.7% vs 1.7%). No substantial differences were found in long-term functional outcomes (ΔeGFR). In terms of costs, CRYO was more cost-effective than RAPN (€5473 vs €10,672), although the gap was partially offset by a higher reimbursement "DRG" rate for robotic partial nephrectomy (€7386 vs €4384). Robot-assisted partial nephrectomy (RAPN) remains the preferred option for treating small renal masses (sRM), providing excellent oncological results and acceptable morbidity. However, percutaneous cryoablation is a valid alternative, particularly for patients unfit for surgery, as long as meticulous postoperative follow-up is carried out.

Nephrometry Scores Based on Three-dimensional Virtual Models Improve the Accuracy of Predicting Postoperative Complications After Robotic Partial Nephrectomy: Results from a Collaborative ERUS Validation Study.

Nephrometry Scores Based on Three-dimensional Virtual Models Improve the Accuracy of Predicting Postoperative Complications After Robotic Partial Nephrectomy: Results from a Collaborative ERUS Validation Study.

Perioperative, Oncological, and Functional Outcomes of New Multiport Robotic Platforms in Urology: A Systematic Review and Meta-analysis.

Perioperative, Oncological, and Functional Outcomes of New Multiport Robotic Platforms in Urology: A Systematic Review and Meta-analysis.

Clinical Trial Protocol for ACCURATE: A CCafU-UroCCR Randomized Trial: Three-dimensional Image-guided Robot-assisted Partial Nephrectomy for Renal Complex Tumor (UroCCR 99).

Clinical Trial Protocol for ACCURATE: A CCafU-UroCCR Randomized Trial: Three-dimensional Image-guided Robot-assisted Partial Nephrectomy for Renal Complex Tumor (UroCCR 99).

Amount of Ipsilateral Parenchymal Volume Preserved Is a Key Determinant of Split Renal Function after Robot-Assisted Partial Nephrectomy.

Objective: To identify factors associated with preserved split renal function (SRF) after robot-assisted partial nephrectomy (RAPN). Patients and Methods: The study included patients who underwent RAPN at Nagasaki University Hospital between November 2016 and December 2023. SRF was determined by 99mTc-dimercaptosuccinic acid renal imaging and the estimated glomerular filtration rate, with measurements obtained before and 6 months after surgery. The ipsilateral parenchymal volume (IPV) was measured at the same time. More than 90% SRF after surgery was considered to indicate successful preservation of renal function (the successful group), and ≤90% SRF was considered failure to preserve renal function (the unsuccessful group). The factors most relevant to SRF were sought in univariate and multivariate analyses. Results: Data for a total of 169 patients were analyzed. The median SRF was 32.04 mL/min/1.73 m2 (interquartile range [IQR] 25.95, 38.06) before surgery and 27.33 mL/min/1.73 m2 (IQR 21.64, 34.32) after surgery. The median SRF preservation rate was 88% (IQR 78.4, 97.0), with 94 cases (55.6%) having SRF >90% and 75 cases (44%) having SRF ≤90%. The median IPV on the surgical side was calculated by the software to be 152.2 cm3 (IQR 126.9, 186.6) preoperatively and 127.3 cm3 (IQR 102.9, 161.3) postoperatively, with a median preservation rate of 84.6% (IQR 72.2, 89.7). Univariate analysis showed significant between-group differences in diabetes status, RENAL Nephrometry score, operation time, warm ischemia time, whether or not parenchymal sutures were needed, and the amount of IPV preserved. Only percentage of IPV preserved remained significant in multivariate analysis. Conclusion: The findings of this study suggest that the residual IPV is an important determinant of SRF after RAPN.