Nephrectomy For Small Renal Masses Research Articles

Outcomes of Laparoscopic Partial Nephrectomy for small renal masses

Background: Due to the increased use of imaging modalities in daily medical practices, more and more small renal masses are detected. For these SRMs, nephron sparing procedures are more commonly opted rather than radical nephrectomy for the sake of preservation of renal function and proven similar oncological outcomes. This surgery has evolved from open, laparoscopic to Robot-assisted approaches. This article summarizes our institutional experience of laparoscopic partial nephrectomy. Materials and Methods: Patients with small renal masses who underwent laparoscopic partial nephrectomy at B.P. Koirala Memorial Cancer Hospital from January 2023 to June 2024 were retrospectively retrieved. Altogether 23 case notes fulfilled the criteria for analysis. All the demographic, preoperative, intraoperative, postoperative data were collected form the notes and plotted. All the issues within 30 days of surgery were defined as early complications. Clavein-Dindo Classification used for analysis. SPSS 25 software was used. Results: Twenty three patients underwent partial nephrectomy with lapascopic method. All were done trans-peritoneally. Average age of patient was 50.96±12.8 years with range of 33-76. Male were 14 and 9 were females. Average hospital stay was 8 days. The majority of patients after PN recovered well. Nonetheless, 8 developed postoperative complications. GI complications were 8.7%, infections related 13%, Wound related 8.7% and others. Two patients (8.3%) were required to undergo reoperation and nephrectomy for haematuria. Conclusion: Laparoscopic partial nephrectomy is a surgery with steep learning curve. As it requires advanced laparoscopic suturing skills, complications in early period was common. After maturity the complications are as par to open PN.

Factors influencing the decision-making in laparoscopic partial nephrectomy for small renal masses.

We analyzed the factors affecting the decision on surgical approach such as hilum dissection, vessel clamping, and the warm ischemia time (WIT) in laparoscopic partial nephrectomy (LPN) for small renal masses (SRMs). Patients who underwent LPN for SRMs between 2011 and 2021 in two centers were retrospectively screened. Standardized R.E.N.A.L. nephrometry score (RNS) and each of the components were scored on a Likert scale and the effect on the surgical approach was examined by using them separately. A total of 133 patients, 85 of whom were on-clamp and 48 were off-clamp, were included in the study. Greater tumor size, low BMI, higher RNS, upper pole tumor, low exophytic rate, and nearness to the collecting system were statistically significant for both on/off-clamp and hilar dissection decisions. In multivariate analysis, greater tumor size, upper pole tumor, lower rate of exophytic part (E2), nearness to the collecting system (N3) were independent risk factors for vessel clamping. Greater tumor size and lower exophytic tumor rate (E2) were independent risk factors for hilum dissection. We could not identify any factor affecting WIT. Individual components of RNS may serve as a better tool for decision-making on vessel clamping and hilum dissection during LPN for SRMs.

MP47-16 MICROWAVE ABLATION VERSUS PARTIAL NEPHRECTOMY FOR SMALL RENAL MASSES

You have accessJournal of UrologyCME1 Apr 2023MP47-16 MICROWAVE ABLATION VERSUS PARTIAL NEPHRECTOMY FOR SMALL RENAL MASSES Jessica Qiu, Emmett H. Kennady, Chris Ballantyne, Clinton Yeaman, John Morgan, Anthony Denovio, Matthew B. Clements, J. Patrick Mershon, Iman Richie, Tracey L Krupski, Noah S. Schenkman, and Jennifer M. Lobo Jessica QiuJessica Qiu More articles by this author , Emmett H. KennadyEmmett H. Kennady More articles by this author , Chris BallantyneChris Ballantyne More articles by this author , Clinton YeamanClinton Yeaman More articles by this author , John MorganJohn Morgan More articles by this author , Anthony DenovioAnthony Denovio More articles by this author , Matthew B. ClementsMatthew B. Clements More articles by this author , J. Patrick MershonJ. Patrick Mershon More articles by this author , Iman RichieIman Richie More articles by this author , Tracey L KrupskiTracey L Krupski More articles by this author , Noah S. SchenkmanNoah S. Schenkman More articles by this author , and Jennifer M. LoboJennifer M. Lobo More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003293.16AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Thermal ablation (TA) is a widely accepted approach for T1a renal masses < 3 cm in size, with a gap in research of masses sized 3-4 cm. While much literature focuses on radiofrequency ablation (RFA) as the primary TA modality, a growing body of literature is showing the safety and efficacy of microwave ablation (MWA). In this study we aim to compare the oncological and renal function outcomes of MWA compared to partial nephrectomy (PN) in two small renal mass (SRM) tumor size groups, <3 cm and 3-4 cm. METHODS: This study included retrospective data from 2009-2015 and prospective data since 2015 from a single-institution database. Patient demographics, renal mass characteristics, and treatment outcomes were collected. Survival curves and hazard analysis were used to assess oncological outcomes. Changes in eGFR and CKD stage following surgery were used to assess renal function outcomes. RESULTS: A total of 91 PN and 130 MWA patients matched the inclusion criteria. For both tumor sizes, median age and Charlson Comorbidity Index (CCI) of MWA patients were greater than PN, while median length of stay was shorter . No difference in local recurrence free survival was found between treatment modalities on survival analysis for masses < 3 cm (p=0.56) and sized 3-4 cm (p=0.15). No difference in local recurrence free survival was found between treatment modalities on hazard analysis for masses < 3 cm (p=0.56) and sized 3-4 cm (p=0.70). Pre-operative renal function was significantly lower in patients undergoing MWA for both tumor sizes, however there was no significant difference in the post-operative change in renal function between MWA and PN for tumors up to 4 cm. CONCLUSIONS: While MWA patients are older and have more comorbidities, oncological outcomes and renal preservation were comparable between MWA and PN for SRMs < 3 cm and 3-4 cm. Our findings suggest that MWA can be used as a safe and effective alternative to PN for SRM tumors up to 4 cm. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e650 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jessica Qiu More articles by this author Emmett H. Kennady More articles by this author Chris Ballantyne More articles by this author Clinton Yeaman More articles by this author John Morgan More articles by this author Anthony Denovio More articles by this author Matthew B. Clements More articles by this author J. Patrick Mershon More articles by this author Iman Richie More articles by this author Tracey L Krupski More articles by this author Noah S. Schenkman More articles by this author Jennifer M. Lobo More articles by this author Expand All Advertisement PDF downloadLoading ...

Randomized Clinical Trial Comparing On-clamp Versus Off-clamp Laparoscopic Partial Nephrectomy for Small Renal Masses (CLOCK II Laparoscopic Study): A Intention-to-treat Analysis of Perioperative Outcomes

BackgroundRecent randomized trials (RCTs) in the field of robotic partial nephrectomy (PN) showed no significant differences in perioperative outcomes between the off- and on-clamp approaches. ObjectiveTo compare the perioperative outcomes of on- versus off-clamp pure laparoscopic PN (LPN). Design, setting, and participantsA multi-institutional analysis of the on- versus off-clamp approach during LPN in the setting of an RCT (CLOCK II trial; ClinicalTrials.gov NCT02287987) was performed. InterventionOff- versus on-clamp LPN. Outcome measurements and statistical analysisBaseline patient and tumor variables, and peri- and postoperative data were collected. Randomized allocation with a 1:1 ratio was assigned. Surgical strategy for managing the renal pedicle was dictated by the study protocol. In the off-clamp arm, the renal artery had to remain unclamped for the duration of the whole procedure. Reporting the intention-to-treat analysis is the purpose of the study. Results and limitationsThe study recruited 249 patients. Of them, 123 and 126 were randomized and allocated into the on- and off-clamp treatment groups, respectively. Treatment groups were comparable at baseline after randomization with respect to patients’ demographics, comorbidities, renal function, and tumor size and complexity. A univariable analysis found no differences in the perioperative outcomes between the groups, including median (interquartile range) estimated blood loss (150 [100–200] vs 150 [100–250] ml, p = 0.2), grade ≥2 complication rate as classified according to the Clavien-Dindo system (5.7% vs 4.8%, p = 0.6), and positive surgical margin rate (8.2% vs 3.5% for the on- vs off-clamp group, p = 0.1). No differences were found in terms of the 1st (81.3 [66.7–94.3] vs 85.3 [71.0–97.7] ml/min, p = 0.2) and 5th postoperative days estimated glomerular filtration rate (83.3 [70.5–93.7] vs 83.4 [68.6–139.3] ml/min, p = 0.2). A multivariable analysis found each +1 increase in RENAL score corresponded to an increase in the protection from the occurrence of complications (odds ratio [OR] 0.72, 95% confidence interval [CI] 0.54–0.97, p = 0.034), while each +1 cm increase in tumor size corresponded to an increase in the risk of blood transfusion (OR 1.39, 95% CI 1.14–1.70, p = 0.001). ConclusionsIn the setting of an RCT, no differences were found in the perioperative and early functional outcomes between on- and off-clamp LPN. Patient summaryIn this study, we investigated, by means of a randomized trial, whether avoiding the clamping of renal artery during laparoscopic resection of renal mass is able to translate into benefits. We found no differences in terms of safety, efficacy, and renal function from the standard approach, which includes arterial clamping.

Cost-effectiveness analysis: percutaneous microwave ablation vs robotic-assisted partial nephrectomy for small renal masses.

The majority of newly diagnosed renal tumors are masses < 4cm in size with treatment options, including active surveillance, partial nephrectomy, and ablative therapies. The cost-effectiveness literature on the management of small renal masses (SRMs) does not account for recent advances in technology and improvements in technical expertise. We aim to perform a cost-effectiveness analysis for percutaneous microwave ablation (MWA) and robotic-assisted partial nephrectomy (RA-PN) for the treatment of SRMs. We created a decision analytic Markov model depicting management of the SRM incorporating costs, health utilities, and probabilities of complications and recurrence as model inputs using TreeAge. A willingness to pay (WTP) threshold of $100,000 and a lifetime horizon were used. Probabilistic and one-way sensitivity analyses were performed. Percutaneous MWA was the preferred treatment modality. MWA dominated RA-PN, meaning it resulted in more quality-adjusted life years (QALYs) at a lower cost. Cost-effectiveness analysis revealed a negative Incremental Cost-Effectiveness Ratio (ICER), indicating dominance of MWA. The model revealed MWA had a mean cost of $8,507 and 12.51 QALYs. RA-PN had a mean cost of $21,521 and 12.43 QALYs. Relative preference of MWA was robust to sensitivity analysis of all other variables. Patient starting age and cost of RA-PN had the most dramatic impact on ICER. MWA is more cost-effective for the treatment of SRM when compared with RA-PN and accounting for complication and recurrence risk.

SC253 - Frailty status predicts worse postoperative and long-term oncologic outcomes in patients treated with partial nephrectomy for small renal masses

SC253 - Frailty status predicts worse postoperative and long-term oncologic outcomes in patients treated with partial nephrectomy for small renal masses

319 Systematic Review of Safety and Oncological Outcomes of Irreversible Electroporation in Renal Tumours

Abstract Introduction Thermal tumour ablation techniques are effective alternatives to nephrectomy for small renal masses (SRM). Thermal effects limit their use in tumours adjacent to vital structures. We review safety and oncological outcomes of irreversible electroporation (IRE), a novel non-thermal ablation technique, in SRMs. Method MEDLINE, EMBASE, and SCOPUS databases were interrogated up to 29/11/2020 for studies reporting safety and oncological outcomes for SRMs in humans treated by IRE. Results Of 224 results screened, 10 met the inclusion criteria. In total, 83 patients were identified. Except for one cohort study (n = 41), remaining studies were case series of n &amp;lt; 10. Follow up was &amp;lt;12 months in 7/10 articles (Range 3-34 months). 10/10 articles reported safety outcomes. There were no 30-day mortalities. The most reported adverse events were transient haematuria (11/83) and asymptomatic perirenal haematomas (7/83). 62/63 patients with reported length of stay were discharged within 24 hours. No significant long-term changes in renal function were reported. 7/10 articles reported oncological outcomes. Only 1 article assessed histopathology outcomes. Remaining studies used CT, PET, or MRI for assessment. 4/7 (57%) patients with histopathology outcomes, showed complete response (CR). 43/55 (78%) patients with imaging base outcomes, showed CR. No mortalities were reported due to SRMs. Conclusions Initial findings support IRE as safe and feasible in managing SRMs. Results from larger studies with longer follow-up are needed to evaluate oncological outcomes and compare these with other ablation methods. Discrepancy between CR rates in histopathology vs imaging assessment could indicate higher sensitivity of histopathology for assessing outcomes.

1637 Ablative Therapies Versus Partial Nephrectomy for Small Renal Masses: A Systematic Review and Meta-Analysis

Abstract Introduction The optimal management of small renal masses is unclear. Ablative therapies (AT) have been advocated as a potential alternative due to lower complication rates and non-inferior oncological outcomes. We performed a systematic review to compare AT and partial nephrectomy (PN) in patients with T1aN0M0 renal masses. Method This review is registered on PROSPERO (CRD42020199099). A search was performed on Medline, EMBASE, and Cochrane CENTRAL to identify studies comparing AT and PN. Different modalities and approaches were analysed as subgroups. Outcomes include cancer-specific survival (CSS), overall survival (OS), recurrence-free survival (RFS), metastatic-free survival (MFS), postoperative complications, and change in renal function. Results From 1,351 identified records, 30 studies incorporating 85,837 patients were included for meta-analysis. Patients receiving AT were found to have significantly worse CSS, OS, RFS when compared to patients receiving PN (p &amp;lt; 0.05). Patients undergoing AT have a non-inferior MFS and significantly fewer overall complications (HR: 0.79, 95% CI 0.41-1.51, p = 0.48; RR: 0.71, 95% CI 0.53-0.96, p = 0.03). Patients undergoing AT have a smaller decline in renal function post-operatively (SMD: 0.30, 95% CI 0.11-0.50). When limited to studies with propensity score matching, CSS and RFS are no longer significantly different between the two groups (HR: 1.54, 95% CI 0.67-3.52, p = 0.31, HR: 1.72, 95% CI 0.90-3.28, p = 0.10). Subgroup analyses did not show significant differences between different modalities and approaches of AT in all outcomes. Conclusions AT is potentially non-inferior to PN when managing small renal masses, and more high-quality propensity score-matched studies with long follow-up time are needed to confirm the non-inferiority.

Re: Is Routine Renal Tumor Biopsy Associated with Lower Rates of Benign Histopathology following Nephrectomy for Small Renal Masses?

Re: Is Routine Renal Tumor Biopsy Associated with Lower Rates of Benign Histopathology following Nephrectomy for Small Renal Masses?

Visceral fat is associated with high-grade complications in patients undergoing minimally invasive partial nephrectomy for small renal masses.

Introduction:Minimally invasive partial nephrectomy is standard of care treatment for small renal masses.Objective:We evaluated the relationship between subcutaneous and visceral obesity with high-grade postoperative 30-day complications in patients undergoing minimally invasive partial nephrectomy.Methods:We retrospectively identified 98 patients at our institution from 2014 to 2017 who underwent laparoscopic or robotic-assisted partial nephrectomy due to suspected renal cell carcinoma. Patients were stratified based on presence or absence of high-grade (Clavien ≥ IIIa) 30-day postoperative complications. Means were compared with the independent t test and proportions with chi-square analysis. Multivariate logistic regression was performed to determine independent predictors of high-grade 30-day complications.Results:Mean nephrometry score was 6.7 with 21 (21.4%) patients having hilar tumors. Mean estimation of blood loss was 207 mL, mean operating time was 223 min, and mean warm ischemia time was 23 min. The majority of patients had clear renal cell carcinoma (n = 83, 84.7%) and pT1a disease (n = 76, 77.6%) with negative margins (n = 89, 90.8%) on pathology. There were 5 (5.1%) patients who experienced a high-grade postoperative 30-day complication. Mean visceral fat index was an independent predictor of high-grade 30-day complications (odds ratio: 1.02; 95% confidence interval: 1.002–1.03; p = 0.027).Conclusions:Visceral obesity should be considered as a prognostic indicator of outcomes in patients undergoing surgical treatment for a small renal mass.

Long-term outcomes of minimally invasive surgeries in partial nephrectomy. Robot or laparoscopy?

To compare long-term oncological and renal functional outcomes of laparoscopic and robotic partial nephrectomy for small renal masses. A total of 103 patients who underwent laparoscopic (n=31) and robotic (n=72) partial nephrectomy between April 2015 and November 2018 were included in the study. Perioperative parameters, long-term oncological and functional outcomes were compared between the laparoscopic and robotic groups. No significant differences were found in terms of age, tumour size, RENAL and PADUA scores, pre-operative estimated glomerular filtration rate (eGFR), and presence of chronic hypertension and diabetes (P=.479, P=.199, P=.120 and P=.073, P=.561, and P=.082 and P=.518, respectively). Only estimated blood loss was significantly higher in the laparoscopic group in operative parameters (158.23±72.24mL vs. 121.11±72.17mL; P=.019), but transfusion rates were similar between the groups (P=.33). In the laparoscopic group, two patients (6.5%) required conversion to open, while no conversion was needed in the robotic group (P=.89). There were no differences in terms of positive surgical margin and complication rates (P=.636 and P=.829, respectively). No significant differences were observed in eGFR changes and post-operative new-onset chronic kidney disease at 1year after the surgery (P=.768, P=.614, respectively). The overall mean follow-up period was 36.07±13.56months (P=.007). During the follow-up period, no cancer-related death observed in both group and non-cancer-specific survival was 93.5% and 94.4% in laparoscopic and robotic groups, respectively (P=.859). In this study, perioperative and long-term oncological and functional outcomes seems to be comparable between laparoscopic and robotic partial nephrectomies.

SC163 - What are the predictors of oncocytoma histology at pathological analysis after partial nephrectomy for small renal masses? insights from a large prospective multicentre study (record 2 project)

SC163 - What are the predictors of oncocytoma histology at pathological analysis after partial nephrectomy for small renal masses? insights from a large prospective multicentre study (record 2 project)

605 - What are the predictors of oncocytoma histology at pathological analysis after partial nephrectomy for small renal masses? Insights from a large prospective multicentre study (RECORd2 project)

605 - What are the predictors of oncocytoma histology at pathological analysis after partial nephrectomy for small renal masses? Insights from a large prospective multicentre study (RECORd2 project)

Factors affecting renal function preservation among patients not achieving trifecta after laparoscopic partial nephrectomy for clinical T1a renal masses.

The goal of partial nephrectomy for renal tumors is complete tumor removal with the preservation of renal function and no complications. Trifecta (total ischemia time < 25 minutes, negative surgical margins, and no surgical complications) is widely used to evaluate success after partial nephrectomy. We investigated factors affecting renal function preservation among patients not achieving trifecta after laparoscopic partial nephrectomy. Sixty-six patients who underwent laparoscopic partial nephrectomy for clinical T1a renal masses between December 2006 and March 2016 were examined. We defined preserved renal function as the preservation of an estimated glomerular filtration rate ≥ 90% 1 year after surgery. We examined factors affecting renal function preservation among patients not achieving trifecta after laparoscopic partial nephrectomy. Thirty out of 66 patients (45%) did not achieve trifecta. In an evaluation of 66 patients, a multivariate analysis identified tumor size (P = .04) as an independent predictor affecting the achievement of trifecta. Tumor size was significantly smaller in the trifecta achievement group (1.9 ± 0.1 cm) than in the non-achievement group (2.2 ± 0.6 cm) (P = .04). We found that renal function was preserved 1 year after surgery in 14 out of the 30 patients not achieving trifecta. In univariate analysis, age (P = .01) was significantly associated with affecting the preservation of renal function among these patients. Patients with preserved renal function were significantly younger (47.8 ± 2.5 years) than those without (58.5 ± 2.9 years) (P = .01). Renal function may be preserved in younger patients even if they do not achieve trifecta after partial nephrectomy for small renal masses.

Letter to the Editor RE: Russo, Editorial Comment on: Treatment Trends and Long-Term Survival Associated with Cryotherapy and Partial Nephrectomy for Small Renal Masses in the National Cancer Database Using Propensity Score Matching by Kitley et al. (From: Russo P. J Endourol 2019;33:415; DOI: 10.1089/end.2019.0121).

Letter to the Editor RE: Russo, Editorial Comment on: Treatment Trends and Long-Term Survival Associated with Cryotherapy and Partial Nephrectomy for Small Renal Masses in the National Cancer Database Using Propensity Score Matching by Kitley et al. (From: Russo P. J Endourol 2019;33:415; DOI: 10.1089/end.2019.0121).

Editorial Comment on: Treatment Trends and Long-Term Survival Associated with Cryotherapy and Partial Nephrectomy for Small Renal Masses in the National Cancer Database Using Propensity Score Matching by Kitley et al. (From: Kitley W, Sulek J, Sundaram C, et al. J Endourol 2019;33:408-414; DOI: 10.1089/end.2018.0548).

Editorial Comment on: Treatment Trends and Long-Term Survival Associated with Cryotherapy and Partial Nephrectomy for Small Renal Masses in the National Cancer Database Using Propensity Score Matching by Kitley et al. (From: Kitley W, Sulek J, Sundaram C, et al. J Endourol 2019;33:408-414; DOI: 10.1089/end.2018.0548).

Treatment Trends and Long-Term Survival Associated with Cryotherapy and Partial Nephrectomy for Small Renal Masses in the National Cancer Database Using Propensity Score Matching.

Objective: Trends in the utilization of ablative therapy are unknown for the treatment of small renal masses. Our goal is to utilize the National Cancer Database (NCDB) to both assess the utilization of ablative therapies and long-term survival. Materials and Methods: The NCDB captures 70% of all cancer cases in the United States and was queried between 1998 and 2012 for renal cell carcinomas that were treated with ablative therapy, partial nephrectomy (PN), or radical nephrectomy. The analysis was limited to clinical stage T1a. Propensity score matching was used in 1:1 fashion. Kaplan-Meier survival analysis and a Cox proportional hazards model were used to compare overall survival (OS) for cryotherapy and PN. Results: A total of 119,240 cases of clinical stage T1a renal masses were treated between 1998 and 2012. Cryotherapy peaked at 927 (9.1%) cases in 2010 and had 913 (8.4%) in 2012. PN accounted for 18% of the cases in 1998, but surpassed the utilization of nephrectomy in 2008. By 2012, PN accounted for 6766 (62%) of renal mass cases. After matching, Kaplan-Meier OS was lower for cryotherapy compared with PN at 24 (94.5% vs 96.5%), 48 (86.8% vs 90.9%), and 96 months (66.0% vs 74.9%). Cryotherapy also had a lower OS (hazard ratio 1.46; p < 0.001) on adjusted analysis. Conclusion: Cryotherapy for small renal masses plateaued at 9% utilization in 2009. Cryotherapy had a lower OS than PN for tumors >2 cm on adjusted analysis, but this result should be used with caution until confirmed in randomized studies.

916 - Comparison of perioperative and oncologic outcomes between cryoablation and partial nephrectomy for small renal masses: A propensity-score matching analysis

916 - Comparison of perioperative and oncologic outcomes between cryoablation and partial nephrectomy for small renal masses: A propensity-score matching analysis

Re: Is Routine Renal Tumor Biopsy Associated with Lower Rates of Benign Histology following Nephrectomy for Small Renal Masses?

Re: Is Routine Renal Tumor Biopsy Associated with Lower Rates of Benign Histology following Nephrectomy for Small Renal Masses?

Modified Nephrometry Score With Body Mass Index More Accurately Predicts Ischemic Time in Transabdominal Laparoscopic Partial Nephrectomy for Small Renal Masses

ObjectiveTo accurately predict the ischemic time (IT) and select candidates for transabdominal laparoscopic partial nephrectomy (LPN). MethodsTransabdominal LPN was performed for 135 Japanese patients with renal masses <7 cm in diameter between 2009 and 2016 by a single surgeon in a single institute. The renal parenchymal sutures were done with a combination of felt, Hem-o-lok and Lapra-Ty. The original R.E.N.A.L. nephreometry score (NS) was modified as follows. In terms of the tumor size (R), 1, 2, and 3 points were given for ≤2.5, 2.5-4, and >4 cm, respectively. For tumor location (A), 1, 2, and 3 points were given for anterior, on the coronal plane, and posterior, respectively. ResultsThe median IT was 24.6 minutes. Using the original NS, 64, 65, and 6 patients were categorized into low (4-6), moderate (7-9), and high (10-12) complexity, respectively. With the modified NS, 42, 75, and 18 patients were categorized into low (5-7), moderate (8-11), and high (12-15) complexity, respectively. Pearson's correlation coefficient (R) between the original NS and IT was 0.297, whereas the R was improved to 0.388 when the modified NS was employed. If the modified NS was low complexity, 95.2% achieved IT <30 minutes. Of them, none showed IT ≥30 minutes if the body mass index was <25 kg/m2. ConclusionThe modified NS had a better correlation to the IT than the original NS for patients with tumor sizes <7 cm who underwent transabdominal LPN. The modified NS with body mass index is a practical tool to select candidates for transabdominal LPN.