Performance in the Fundamentals of Laparoscopic Surgery: Does it reflect global rating scales in the Objective Structured Assessment of Technical Skills in porcine laparoscopic surgery?

Objective: To correlate the utility of the Fundamentals of Laparoscopic Surgery (FLS) manual skills program with the Objective Structured Assessment of Technical Skills (OSATS) global rating scale in evaluating operative performance. Methods: The Asian Urological Surgery Training and Educational Group (AUSTEG) Laparoscopic Upper Tract Surgery Course implemented and validated the FLS program for its usage in laparoscopic surgical training. Delegates' basic laparoscopic skills were assessed using three different training models (peg transfer, precision cutting, and intra-corporeal suturing). They also performed live porcine laparoscopic surgery at the same workshop. Live surgery skills were assessed by blinded faculty using the OSATS rating scale. Results: From March 2016 to March 2019, a total of 81 certified urologists participated in the course, with a median of 5 years of post-residency experience. Although differences in task time did not reach statistical significance, those with more surgical experience were visibly faster at completing the peg transfer and intra-corporeal suturing FLS tasks. However, they took longer to complete the precision cutting task than participants with less experience. Overall OSATS scores correlated weakly with all three FLS tasks (peg transfer time: r=-0.331, r 2=0.110; precision cutting time: r=-0.240, r 2=0.058; suturing with intra-corporeal knot time: r=-0.451, r 2=0.203). Conclusion: FLS task parameters did not correlate strongly with OSATS globing rating scale performance. Although FLS task models demonstrated strong validity, it is important to assimilate the inconsistencies when benchmarking technical proficiency against real-life operative competence, as evaluated by FLS and OSATS, respectively.

Genetic study of the CDKN2A and CDKN2B genes in renal cell carcinoma patients.

Objectives: While recent studies have demonstrated several genetic alterations are associated with pathogenesis of RCC, the significance of cyclin-dependent kinase inhibitor 2A (CDKN2A) and cyclin-dependent kinase inhibitor 2B (CDKN2B) in tumorigenesis of RCC is less clear. We investigate the distribution of CDKN2A and CDKN2B mutations in patients with RCC and analyze the impact of CDKN2A and CDKN2B mutations on RCC. Methods: A pathological examination was conducted using thirty fresh renal tissue samples with renal masses that had undergone partial or radical nephrectomy. Multiplex ligation-dependent probe amplification (MLPA) was used to detect genetic aberrations of CDKN2A and CDKN2B in genomic DNA isolated from samples. Subsequently, CDKN2A and CDKN2B mutations were confirmed using chromosomal microarray technique. Results: Twenty-one patients were diagnosed with RCC, eight with benign diseases, including angiomyolipoma (AML) and oncocytoma, and one with mucinous adenocarcinoma of renal pelvis. Two of twenty-one patients (9.5 %) with clear-cell RCC were positive for CDKN2A and CDKN2B gene deletions. Interestingly, patients with CDKN2A and CDKN2B mutations were associated with sarcomatoid patterns of RCC (2 out of 4, 50 %). In contrast, no CDKN2A or CDKN2B deletions were detected in samples from benign renal tumors, papillary RCC, or other kidney cancers. Conclusions: This study demonstrated the potential use of CDKN2A and CDKN2B as biomarkers for the prognostic and molecular classification of renal cancer. CDKN2A and CDKN2B mutations may be associated with RCC development and sarcomatoid changes. Further research is needed to understand the underlying molecular mechanisms of CDKN2A and CDKN2B in the pathogenesis of RCC.

Long-Term Outcomes of Orthotopic Neobladder Versus Ileal Conduit Urinary Diversion in Robot-Assisted Radical Cystectomy (RARC): Multicenter Results from the Asian RARC Consortium.

PURPOSE: Robot-assisted radical cystectomy (RARC) has gained traction in the management of muscle invasive bladder cancer. Urinary diversion for RARC was achieved with orthotopic neobladder and ileal conduit. Evidence on the optimal method of urinary diversion was limited. Long-term outcomes were not reported before. This study was designed to compare the perioperative and oncological outcomes of ileal conduit versus orthotopic neobladder cases of nonmetastatic bladder cancer treated with RARC. PATIENTS AND METHODS: The Asian RARC consortium was a multicenter registry involving nine Asian centers. Consecutive patients receiving RARC were included. Cases were divided into the ileal conduit and neobladder groups. Background characteristics, operative details, perioperative outcomes, recurrence information, and survival outcomes were reviewed and compared. Primary outcomes include disease-free and overall survival. Secondary outcomes were perioperative results. Multivariate regression analyses were performed. RESULTS: From 2007 to 2020, 521 patients who underwent radical cystectomy were analyzed. Overall, 314 (60.3%) had ileal conduit and 207 (39.7%) had neobladder. The use of neobladder was found to be protective in terms of disease-free survival [Hazard ratio (HR) = 0.870, p = 0.037] and overall survival (HR = 0.670, p = 0.044) compared with ileal conduit. The difference became statistically nonsignificant after being adjusted in multivariate cox-regression analysis. Moreover, neobladder reconstruction was not associated with increased blood loss, nor additional risk of major complications. CONCLUSIONS: Orthotopic neobladder urinary diversion is not inferior to ileal conduit in terms of perioperative safety profile and long-term oncological outcomes. Further prospective studies are warranted for further investigation.

Residual renal volume as a long-term independent predictive factor of developing chronic kidney disease after donor nephrectomy.

To assess the long-term association between the residual renal volume and the progression of chronic kidney disease (CKD) in kidney donors following open or laparoscopic donor nephrectomy. A retrospective observational study involving 452 individuals who underwent open or laparoscopic donor nephrectomy at Ramathibodi Hospital, Bangkok, Thailand. The study spanned over a comprehensive 60-month monitoring period. Residual renal volume was determined through Computer Tomography. Patient characteristics, surgical techniques, donated kidney side, and estimated glomerular filtration rate (eGFR) were collected and analysed. In a multivariate analysis, a residual renal volume exceeding 50% of original volume is associated with an increased likelihood of developing CKD, with a hazard ratio (HR) of 1.675 (P < 0.05), and male gender has a hazard ratio (HR) of 4.013 (P < 0.001). Additionally, age is identified as a minor risk factor for developing CKD, with hazard ratio (HR) of 1.107 (P < 0.001). Higher residual renal volume, male gender, and older age were identified as independent risk factors for the development of CKD following open or laparoscopic donor nephrectomy during long-term follow-up.

Endoscopic Combined Intrakidney Surgery to Remove a Large Renal Calculus in a Transplanted Kidney: A Case Report.

BACKGROUND: Large nephrolithiasis in a transplanted kidney is a rare situation and an associated risk from postoperative allograft dysfunction. We present our first experience with the implementation and successful result of an endoscopic combined intrakidney surgery (ECIKS) performed to remove a large donor-gifted stone after kidney transplant. CASE PRESENTATION: A 47-year-old female recipient with end-stage kidney disease with no identifiable cause underwent deceased donor kidney transplant at our center. Immediately after the operation, her kidney function slowly improved, and noncontrast computed tomography illustrated a large nephrolithiasis without hydronephrosis. After 6 weeks, the patient was treated successfully by ECIKS, and the stone was totally removed. The patient recovered well after surgery without additional adverse events. There were no residual fragments assessed by computed tomography as of 3 months after the surgery. CONCLUSIONS: A large allograft nephrolithiasis can be successfully retrieved using ECIKS. This is technically feasible, safe, and associated with low morbidity.

Predicting perioperative outcomes of robot-assisted radical cystectomy: Data from the Asian Robot-Assisted Radical Cystectomy Consortium.

OBJECTIVES: To report the perioperative outcomes of robot-assisted radical cystectomy and elucidate their risk factors. METHODS: A review of the Asian Robot-Assisted Radical Cystectomy Consortium database from 2007 to 2020 was performed. The perioperative outcomes studied included complication rates, time to solid food intake, estimated blood loss, length of hospital stay, and 30-day readmission rates. RESULTS: Of 568 patients, the overall complication rate was 49.2%, comprising major complications in 15.6%. Preoperative hydronephrosis was associated with an increased risk of major complications (odds ratio 3.27, 95% confidence interval 1.48-7.26, P = 0.004) while neoadjuvant chemotherapy was protective (odds ratio 0.46, 95% confidence interval 0.25-0.84, P = 0.012). The median time to solid food intake was 4 days (interquartile range 3-7) and smoking was a risk factor (odds ratio 4.28, 95% confidence interval 2.36-7.79, P < 0.001) for prolonged time to solid food intake. Median length of hospital stay was 13 days (interquartile range 9-19), and diabetes mellitus (odds ratio 1.66, 95% confidence interval 1.08-2.56, P = 0.021), neoadjuvant chemotherapy (odds ratio 2.21, 95% confidence interval 1.46-3.33, P < 0.001), and orthotopic bladder substitute creation (odds ratio 2.82, 95% confidence interval 1.90-4.18, P < 0.001) were independent risk factors for prolonged length of hospital stay. The 30-day readmission rate was 23.4% and higher in those with bilateral hydronephrosis (odds ratio 4.58, 95% confidence interval 1.97-10.65, P < 0.001) and orthotopic bladder substitute creation (odds ratio 1.87, 95% confidence interval 1.16-3.02, P = 0.010). CONCLUSIONS: There are preoperative conditions which are significant risk factors for adverse perioperative outcomes in robot-assisted radical cystectomy. Most are potentially modifiable and can direct strategies to reduce surgical morbidity related to this major oncological procedure.

Radical prostatectomy outcomes in renal transplant recipients: a retrospective case series of Thai patients.

BACKGROUND: The incidence of prostate cancer in renal transplant recipients (RTR) is similar to the general population. Radical prostatectomy (RP) is the standard of care in the management of clinically localized cancer, but is considered complicated due to the presence of adhesions, and the location of transplanted ureter/kidney. To date, a few case series or studies on RP in RTR have been published, especially in Asian patients. This study aimed to evaluate the efficacy and safety and report the experience with RP on RTR. METHODS: We retrospectively reviewed data of 1270 patients who underwent RP from January 2008 to March 2020, of which 5 patients were RTR. All available baseline characteristics, perioperative and postoperative data (operative time, estimated blood loss (EBL), complications, length of hospital stay, complication), pathological stage, Gleason score, surgical margin status, and pre/postoperative creatinine were reviewed. RESULTS: Of the 5 RTR who underwent RPs (1 open radical prostatectomy (ORP), 1 laparoscopic radical prostatectomy (LRP), 2 robotic-assisted laparoscopic radical prostatectomies (RALRP), and 1 Retzius-sparing RALRP (RS-RALRP)) prostatectomy, the mean age (± SD) was 70 (± 5.62) years. In LRP and RALRP cases, the standard ports were moved slightly medially to prevent graft injury. The mean operative time ranged from 190 to 365 min. The longest operative time and highest EBL (630 ml) was the ORP case due to severe adhesion in Retzius space. For LRP and RALRP cases, the operative times seemed comparable and had EBL of ≤ 300 ml. All RPs were successful without any major intra-operative complication. There was no significant change in graft function. The restorations of urinary continence were within 1 month in RS-RALRP, approximately 6 months in RALRP, and about 1 year in ORP and LRP. Three patients with positive surgical margins had prostate-specific antigen (PSA) persistence at the first follow-up and 1 had later PSA recurrence. Two patients with negative margins were free from biochemical recurrence at 47 and 3 months after their RP. CONCLUSIONS: Our series suggested that all RP techniques are safe and feasible mode of treatment for localized prostate cancer in RTR.

Intraoperative assessment of ureter perfusion after revascularization of transplanted kidneys using intravenous indocyanine green fluorescence imaging.

BACKGROUND: Kidney transplantation is the most valuable renal replacement therapy. One of the most common urologic complications following kidney transplantation is ureter anastomosis leakage, which leads to high morbidity along with kidney graft loss. We hypothesized that indocyanine green (ICG) fluorescence videography can assess ureter perfusion after revascularization of transplanted kidneys. METHODS: We conducted a prospective cross-sectional study in end-stage renal disease patients who underwent deceased donor kidney transplantation at Ramathibodi Hospital from September 2019 to January 2020. The segments of transplanted ureters were categorized as having good or poor perfusion based on the percentage from ICG fluorescence videography images. Then the results from ICG fluorescence videography were compared with histopathology which is considered the gold standard. RESULTS: Thirty-one sections of dissected ureters were evaluated from 10 patients. Compared with pathological diagnosis of ureteral ischemia, ICG videography had sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive likelihood ratio of 100%, 92.6%, 66.7%, 100%, and 14, respectively. Accuracy was 93.6%. The area under the curve of ICG fluorescence videography was 0.96. The average ureter length that maintained good perfusion was 14 cm from the ureteropelvic junction. Adverse events from ICG were not observed in this study. CONCLUSIONS: We conclude that ICG fluorescence videography is beneficial for detection of early ureteral ischemia in kidney transplantation patients, with negligible adverse events. However, further studies with larger numbers of patients are necessary to confirm our results and clinical outcomes regarding complication rates.

Comparative Outcomes and Predictive Assessment of Trifecta in Open, Laparoscopic, and Robotic-Assisted Partial Nephrectomy Cases with Renal Cell Carcinoma: A 10-Year Experience at Ramathibodi Hospital.

PURPOSE: To compare perioperative and trifecta outcomes of open partial nephrectomy (OPN), laparoscopic partial nephrectomy (LPN), and robotic-assisted laparoscopic partial nephrectomy (RPN) in patients with small renal mass at Ramathibodi Hospital, and to determine predictive factors in connection with trifecta. METHODS: We retrospectively reviewed 141 patients who underwent partial nephrectomy by eight experienced surgeons from January 2009 to December 2018. Baseline preoperative characteristics, postoperative and trifecta outcomes of the three treatment modalities were compared and analyzed. Univariate analysis was performed to determine predictive factors for trifecta achievement. RESULTS: A total of 70 patients had complete data available. Eighteen OPN, 11 LPN and 41 RPN cases were identified and reviewed. All preoperative and perioperative parameters were similar, except for operative time, which was significantly shorter in the OPN group compared with those undergoing LPN and RPN (135 vs 189 and 225 min, respectively; p-value = 0.001). Of these 70 patients, 59 were deemed eligible for and included in trifecta analysis, which revealed similar trifecta outcomes (64.29%, 45.45%, and 64.71% in the OPN, LPN, and RPN groups, respectively; p-value = 0.388). Univariate analysis showed that length of hospital stay was a negative associated factor for trifecta achievement (p-value = 0.007, 95% CI = 0.619 (0.44-0.88)). CONCLUSION: Although OPN displayed the shortest operative time, the trifecta achievement rate was not significantly different among the three groups. The sole parameter, which was negatively associated with trifecta outcome achievement, was the length of hospital stay.

Perioperative Outcomes of Robot-Assisted Radical Cystectomy with Intracorporeal Versus Extracorporeal Urinary Diversion.

PURPOSE: This study was designed to investigate and compare the perioperative outcomes of intracorporeal urinary diversion (ICUD) versus extracorporeal urinary diversion (ECUD) following robotic-assisted radical cystectomy (RARC) in patients with localized bladder cancer from the Asian Robot-Assisted Radical Cystectomy (RARC) Consortium. METHODS: The Asian RARC registry was a multicenter registry involving nine centers in Asia. Consecutive patients who underwent RARC were included. Patient and disease characteristics, intraoperative details, and perioperative outcomes were reviewed and compared between the ICUD and ECUD groups. Postoperative complications were the primary outcomes, whereas secondary outcomes were the estimated blood loss and the duration of hospitalization. Multivariate regression analyses were performed to adjust potential confounders. RESULTS: From 2007 to 2020, 556 patients underwent RARC; 55.2% and 44.8% had ICUD and ECUD, respectively. ICUD group had less estimated blood loss (423.1 ± 361.1 vs. 541.3 ± 474.3 mL, p = 0.002) and a shorter hospital stay (15.7 ± 12.3 vs 17.8 ± 11.6 days, p = 0.042) than the ECUD group. Overall complication rates were similar between the two groups. Upon multivariate analysis, ICUD was associated with less estimated blood loss (Regression coefficient: - 143.06, 95% confidence interval [CI]: - 229.60 to - 56.52, p = 0.001) and a shorter hospital stay (Regression coefficient: - 2.37, 95% CI: - 4.69 to - 0.05, p = 0.046). In addition, ICUD was not associated with any increased risks of minor, major, and overall complications. CONCLUSIONS: RARC with ICUD was safe and technically feasible with similar postoperative complication rates as ECUD, with additional benefits of reduced blood loss and a shorter hospitalization.

Neoadjuvant Androgen Deprivation Therapy Effects on Perioperative Outcomes Prior to Radical Prostatectomy: Eleven Years of Experiences at Ramathibodi Hospital.

OBJECTIVE: The aim of this study was to demonstrate the efficacy of neoadjuvant androgen deprivation therapy (NADT) on perioperative outcomes in patients who underwent radical prostatectomy (RP). MATERIALS AND METHODS: From January 2008 to July 2018, we collected retrospective data of patients with clinically localized prostate cancer who underwent RP to assess their perioperative and pathological outcomes. The data included age, body mass index (BMI), serum prostate specific antigen (PSA) level, clinical stage, neoadjuvant ADT usage, operative time, estimated blood loss (EBL), perioperative complications, blood transfusion rate, adjacent organ injury rate, length of hospital stay, pathological stage, Gleason score (GS) of the biopsy and pathological specimen, specimen weight (g), and margin status. RESULTS: Of the 718 RPs performed, 138 (19.22%) were NADT and 580 (80.78%) were non-NADT. Patients who underwent NADT had a significant benefit in operative time (185 vs 195 mins), EBL (300 vs 500 mL) and specimen weight. These benefits were more obvious in non-low risk prostate cancer with less operative time, EBL, blood transfusion rate, length of hospital stay and specimen weight. However, the margin status and adjacent organ injury rate were similar in the NADT and non-NADT groups. CONCLUSION: NADT provides significantly better perioperative outcomes, especially in non-low risk prostate cancer, and has comparable pathological outcomes.

Surgical training for anatomical endoscopic enucleation of the prostate.

Anatomical endoscopic enucleation of the prostate has been proposed as a potentially superior benign prostatic hyperplasia surgery than conventional transurethral resection of prostate. However, the learning curve of the procedure is steep, hence limiting its generalisability worldwide. In order to overcome the learning curve, a proper surgical training is extremely important. This review article discussed about various aspects of surgical training in anatomical endoscopic enucleation of the prostate. In summary, no matter what surgical technique or energy modality you use, the principle of anatomical enucleation should be followed. When one starts to perform prostate enucleation, a 50 to 80 g prostate appears to be the 'best case' to begin with. Mentorship is extremely important to shorten the learning curve and to prevent drastic complications from the procedure. A proficiency-based progression training programme with the use of simulation and training models should be the best way to teach and learn about prostate enucleation. Enucleation ratio efficacy is the preferred measure for assessing skill level and learning curve of prostate enucleation. Morcellation efficiency is commonly used to assess morcellation performance, but the importance of safety rather than efficiency must be emphasised.

Review of the evidence for robotic-assisted robotic cystectomy and intra-corporeal urinary diversion in bladder cancer.

Radical cystectomy, pelvic lymph node dissection and urinary diversion is the gold-standard treatment for muscle-invasive bladder cancer. The surgery is both complex and highly morbid. Robotic cystectomy is now in its 16th year with established techniques and sufficient research maturity to enable comparison with its open counterpart. The present review focuses on the current evidence for robotic cystectomy and assesses various metrics including oncological, perioperative, functional, surgeon-specific and cost outcomes. The review also encapsulates the current evidence for intra-corporeal urinary diversion and its current status in the cystectomy arena.

Perioperative outcomes of robotic-assisted laparoscopic radical prostatectomy, laparoscopic radical prostatectomy and open radical prostatectomy: 10 years of cases at Ramathibodi Hospital.

BACKGROUND: This study aims to compare the perioperative and pathological outcomes of open radical prostatectomy (ORP), laparoscopic radical prostatectomy (LRP), and robotic-assisted laparoscopic radical prostatectomy (RALRP) at Ramathibodi Hospital within Mahidol University in Thailand. METHODS: From January 2008 to July 2017, 679 RPs were performed. Patients' data were collected retrospectively to evaluate their perioperative and pathological outcomes. This data included the age, body mass index (BMI), serum prostate specific antigen (PSA) level, clinical stage, Gleason score (GS) from biopsy, operative time, estimated blood loss (EBL), perioperative complications, blood transfusion rate, adjacent organ injury rate, length of hospital stay, pathological stage, GS of the biopsy specimen, specimen weight (g), and marginal status of the patients. RESULTS: Of the 679 RPs performed, 128 (19.28%) were ORPs, 241 (36.30%) were LRPs, and 295 (44.43%) were RALRPs. Patients who underwent a RALRP had a significant advantage in EBL (1,600, 500, and 300 mL for ORPs, LRPs, and RALRPs, respectively), overall complications, and blood transfusion rate. As they are minimally invasive techniques, LRP and RALRP presented an advantage in terms of the length of hospital stay (an average of 9, 6, and 6 days for ORPs, LRPs, and RALRPs, respectively) and adjacent organ injury rate. ORPs also had the shortest operative time (160, 210, and 200 min for ORPs, LRPs, and RALRPs, respectively). However, the specimen weight and marginal status were similar in all of the techniques. CONCLUSIONS: Minimally invasive RP techniques, such as LRPs and RALRPs, appear to be safe, have significantly better perioperative outcomes than ORPs, and have comparable pathological outcomes to those of ORPs.

A newly developed porcine training model for transurethral piecemeal and en bloc resection of bladder tumour.

PURPOSE: The Asian Urological Surgery Training & Education Group (AUSTEG) has been established to provide training and education to young urologists in Asia. We developed and validated a porcine bladder training model for transurethral resection of bladder tumour (TURBT). METHODS: Urology residents and specialists were invited to test the training model. They were asked to complete a pre-task questionnaire, to perform piecemeal and en bloc resection of 'bladder tumours' within the training model, and to complete a post-task questionnaire afterwards. Their performances were assessed by faculty members of the AUSTEG. For the face validity, a pre-task questionnaire consisting of six statements on TURBT and the training model were set. For the content validity, a post-task questionnaire consisting of 14 items on the details of the training model were set. For the construct validity, a Global Rating Scale was used to assess the participants' performances. The participants were stratified into two groups (junior surgeons and senior surgeons groups) according to their duration of urology training. RESULTS: For the pre-task questionnaire, a mean score of ≥ 4.0 out of 5.0 was achieved in 5 out of 6 statements. For the post-task questionnaire, a mean score of ≥ 4.5 out of 5.0 was achieved in every item. For the Global Rating Scale, the senior surgeons group had higher scores than the junior surgeons group in 8 out of 11 items as well as the total score. CONCLUSION: A porcine TURBT training model has been developed, and its face, content and construct validity has been established.

Renal Leiomyoma: A Case Report and Review of the Literature.

Leiomyoma is an uncommon tumor of the kidney. The authors report a rare case of renal leiomyoma in a 39-year-old male patient who presented with a right flank mass. Laparoscopic nephrectomy was performed. The histopathology and immunohistochemistry confirm the diagnosis of renal leiomyoma. The review of literature in the clinicoradiopathological correlation was illustrated.

Comparison of Pfannenstiel or Extended Iliac Port Site Kidney Extraction in Laparoscopic Donor Nephrectomy: Do We Have Consensus?

OBJECTIVES: Our objective was to compare the outcomes of the different extraction sites between extended iliac port site incision and Pfannenstiel incision during laparoscopic donor nephrectomy. MATERIALS AND METHODS: We prospectively evaluated patients who underwent laparoscopic donor nephrectomy from June 2014 to March 2015 at our institution. Perioperative parameters were included, with particular reference to warm ischemic time. The other parameters recorded included operative time, blood loss, hospital stay, analgesic requirement, and cosmetic results. RESULTS: We analyzed a total of 41 patients. Kidney retrieval site of each patient was made randomly. Extraction sites were done by using extended iliac port site incisions in 23 patients and by Pfannenstiel incision in 18 patients. Mean warm ischemic time was 4.09 minutes with extended iliac port site incision versus 4.94 minutes with Pfannenstiel incision (P = .04). Mean operative time, blood loss, hospital stay, and analgesic requirements were comparable between the 2 groups. Mean cosmetic score was 10.39 with extended iliac port site versus 12.06 with Pfannenstiel incision. CONCLUSIONS: Extraction with extended iliac port site incision had significantly less warm ischemic time than Pfannenstiel incision in laparoscopic donor nephrectomy. It was also not inferior to Pfannenstiel incision regarding the other.

R.E.N.A.L. nephrometry score in clinical stage T1 renal mass: Ramathibodi hospital experience.

OBJECTIVE: The main treatment strategies for clinical stage T1 renal mass are radical nephrectomy (RN) and partial nephrectomy (PN). Treatment decision depends largely on tumor complexity as assessed by the R.E.N.A.L. nephrometry scoring system. The authors evaluated our experience with R.E.N.A.L. nephrometry score in all patients who underwent surgery. MATERIAL AND METHOD: The authors evaluated 61 patients who presented with clinical stage T1 renal mass and underwent radical or partial nephrectomy between 2007 and 2013 at Ramathibodi Hospital. Tumor complexity was quantified by R.E.N.A.L. nephromety score in all patients using preoperative imaging. Statistical analysis was done to study associations. RESULTS: Sixty-one patients were included in this study, which 34 (55.70%) were male and 27 (44.30%) were female. The most common pathologic report was clear cell renal cell carcinoma followed by angiomyolipoma and papillary renal cell carcinoma. Forty-one patients underwent radical nephrectomy, of whom three, 25, and 10 patients had low, moderate, and high tumor complexity respectively. Twenty patients underwent partial nephrectomy, of whom 10 patients had low tumor complexity and 10 patients had moderate tumor complexity. No patient had high tumor complexity. In the present study, the function coefficient showed that radius had the most influence on surgical decision-making,followed by nearness to collecting system, exophytic/endophytic, and location. We also developed the Ramathibodi equation to help selecting the proper operation. CONCLUSION: The R.E.N.A.L. nephrometry score is a feasible and standardized classification system for evaluating renal masses. It could be used to stratify tumor complexity and may help for surgical decision-making.