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.

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.

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.

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.

External Validation of the S.T.O.N.E. Score in Predicting Stone-Free Status After Rigid Ureteroscopic Lithotripsy.

BACKGROUND: The Size, Topography, Obstruction, Number, and Evaluation of Hounsfield units (S.T.O.N.E.) scoring system has been proposed as a novel prognostic surgical classification for urolithiasis in predicting success rate and complications. OBJECTIVE: We carried out an externally validated S.T.O.N.E. score on rigid ureteroscopic lithotripsy (rURS). MATERIALS AND METHODS: The data of patients who had undergone rURS between 2012 and 2019 at a tertiary referral center were audited retrospectively. The S.T.O.N.E. score was calculated based on factors determined through preoperative computed tomography images and was analyzed in association with stone-free rate (SFR), operating time, surgical complications, and length of stay (LOS). RESULTS: A total of 155 patients were included in the study with a median stone size of 10 mm (7-12) and a median S.T.O.N.E. score of 9 (8-10). The overall SFR was 89.68%. SFRs were 100.0%, 97.83%, and 77.42% in low (5), moderate (6-9), and high (10-13) score groups, respectively. The S.T.O.N.E. score (p = 0.002) and stone size (p = 0.037) were predictive factors for SFR in multivariate analysis. Moreover, there was a significant correlation between the S.T.O.N.E. score and operative time, LOS, and presence of complications (r = 0.22, p = 0.006; r = 0.30, p < 0.001; and r = 0.27, p < 0.001, respectively). The area under the curve of the receiving operator characteristics' curve for the S.T.O.N.E. score was 0.815. CONCLUSION: The S.T.O.N.E. scoring system is simple and effective in predicting postoperative outcomes; therefore, this score would be a valuable tool in clinical planning for every patient who undergoes rURS.

Prospective Randomized Controlled Trial to Evaluate the Effectiveness of Watching Movies to Decrease Anxiety During Extracorporeal Shock Wave Lithotripsy.

BACKGROUND: Extracorporeal shock wave lithotripsy (ESWL) is the only non-invasive treatment for urolithiasis; however, it can cause anxiety and pain for patients. Several new nonpharmacological adjuvant approaches have been developed to reduce adverse events. OBJECTIVE: To analyze the efficacy of watching movies during ESWL to relieve anxiety and pain. METHODS: A total of 84 patients were randomly divided into two groups. The experimental group consisted of 42 patients who watched their own selected movies during the ESWL session, while the control group included 42 patients who did not watch movies. Basic characteristics, hemodynamic parameters, State-Trait Anxiety Inventory, Visual Analog Scale for pain, willingness to repeat the procedure, and patient satisfaction rates were collected and analyzed. RESULTS: After watching movies during ESWL, patients had a significantly lower anxiety level (p = 0.001) and a higher satisfaction rate (p = 0.021). No statistically significant differences were found in terms of demographic data, hemodynamic parameters, pain scores, or willingness to repeat the procedure. CONCLUSION: Watching self-selected movies during an ESWL can effectively reduce anxiety and improve satisfaction.

Risk Factors for Anastomosis Leakage After Kidney Transplantation.

PURPOSE: Kidney transplantation is one of the best treatment options for end-stage renal disease with an incidence of urologic complications of 2.5 to 30%. One of the most serious and frequent urological complications is urinary leakage from ureteroneocystostomy anastomosis. The purpose of this study was to evaluate risk factors of urinary leakage from ureteroneocystostomy anastomosis after kidney transplantation. PATIENTS AND METHODS: A retrospective study was performed on patients who received kidney transplantation and were diagnosed with urinary leakage thereafter based on renal scan or drain creatinine per serum creatinine compared with patients in control group. Risk factor assessment was based on inpatient and outpatient information from hospital database. RESULTS: From 459 patients who received kidney transplantation in 2016-2018, there were 20 patients who were diagnosed with urinary leakage after they underwent ureteroneocystostomy anastomosis. The significant risk factors for anastomosis leakage were size of suture materials and duration of ureteral stent insertion. No statistically significant difference in other factors such as underlying disease, surgical technique or duration of urinary catheter was found. About overall urological complication, gender and body mass index significantly affected the outcome. CONCLUSION: The rate of urinary leakage complications was found to be about 4.36%. The risk factors of overall complication comprised gender and body mass index. Although a lot of previous studies revealed many risk factors that could affect urinary leakage, size of suture materials and duration of ureteral stent insertion were the significant risk factors in our study. Proper consideration should be given to the size of suture materials and optimal duration of ureteral stent.

Perioperative outcomes of robot-assisted laparoscopic radical prostatectomy (RALRP) and LRP in patients with prostate cancer based on risk groups.

OBJECTIVE: To compare the perioperative and pathological outcomes between robot-assisted laparoscopic radical prostatectomy (RALRP) and LRP based on the patient's risk. PATIENTS AND METHODS: The medical records of 588 patients with prostate cancer who underwent RP, using minimally invasive surgery (MIS) techniques (240 LRP and 348 RALRP) by a single surgeon during January 2008 to June 2018 at the Ramathibodi Hospital, were retrospectively reviewed. The patient's risk was classified according to the National Comprehensive Cancer Network (NCCN) Guideline, 2018. The demographic, perioperative, and pathological data of patients were collected. The differences in perioperative and pathological outcomes between LRP and RALRP in each risk classification were assessed using chi-square, Fisher's exact tests and logistic regression, as appropriate. RESULTS: In terms of positive margins, RALRP had significant advantages in high-risk patients when compared to LRP (adjusted odds ratio 0.46, 95% confidence interval 0.26-0.84), while there were no differences in the low- and intermediate-risk patients. Overall, the patients who underwent RALRP had significant advantages over those who underwent LRP in terms of operative time, estimate blood loss, and blood transfusion rate. While, adjacent organ injury rate and length of hospital stay were similar for both techniques in all subgroup analyses. CONCLUSION: MIS techniques appear to be safe, especially RALRP, which has significantly better perioperative outcomes in all subgroups of patient risk classification, and in the high-risk patient group it seems to have better pathological outcomes when compared to LRP. ABBREVIATIONS: EBL: estimated blood loss; LOS: length of hospital stay; PSM: positive surgical margin; (L)(O)(RAL)RP: (laparoscopic) (open) (robot-assisted laparoscopic) radical prostatectomy; MIS: minimally invasive surgery.

Peri-Operative Factors Affecting Blood Transfusion Requirements During PCNL: A Retrospective Non-Randomized Study.

BACKGROUND: Percutaneous nephrolithotomy (PCNL) is accepted as the gold standard of care for the treatment of large renal calculi. Kidney hemorrhage, which requires blood transfusion, is one of the most common complications after percutaneous kidney stone surgery. OBJECTIVE: To evaluate perioperative factors associated with transfusion requirements during PCNL. MATERIALS AND METHODS: A total of 226 patients with kidney calculi undergoing PCNL between January 2011 and December 2019 were reviewed retrospectively. We analyzed the impact of perioperative clinical factors on the necessity of blood transfusion during PCNL. RESULTS: The overall blood transfusion rate was 9.29%. Multiple perioperative determinants were significantly correlated with the application of packed red blood cells (PRCs), including larger stone size (p = 0.006), multiple tract punctures (p = 0.029), presence of staghorn calculi (p = 0.026), and long operative time (OT; p = 0.017). Multivariate analysis demonstrated that only multiple tract punctures independently affected blood transfusion requirements during PCNL (p = 0.038). CONCLUSION: In accordance with the present study, only the multiple tract punctures were associated with blood transfusion requirements in PCNL.

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.

The best calyceal tract approach for treating renal stones with percutaneous nephrolithotomy.

OBJECTIVE: To compare the perioperative outcomes of percutaneous nephrolithotomy (PCNL) performed via the upper middle, and lower calyces. MATERIAL AND METHOD: The authors retrospectively reviewed 92 renal units in 92 patients who required PCNL at our institution between 2006 and 2010. Patients with partial and full staghorn stones with total stone size > or = 2 cm were included in the present study. Patients were excluded if they had multiple small stones or a single stone < 2 cm. The present study analyzed 92 renal units in 92 patients. The authors divided the patients into three groups (groups 1, 2, and 3) based on the surgical approach, which was the upper middle, and lower calyceal approaches. PCNL was performed using a standard ultrasonic lithotriptor with a rigid nephroscope, and holmium: YAG laser lithotripsy was carried out with a flexible nephroscope, with simultaneous nitinol tipless basket extraction of fragments. Procedures were repeated until the patients were rendered stone-free (confirmed visually or by nephrostogram). Estimated blood loss, length of hospital stay, operative time, and the number of procedures (to achieve stone-free status) were analyzed and compared among the groups, and complications were reported. RESULTS: The present study showed that the length of hospital stay, estimated blood loss, number of procedures, and operative time were not significantly different between the three groups. In Group 1, four patients had complications and included two patients with mid-ureteral stone, and one patient each with renal pelvic perforation and urinary tract infection with sepsis. One patient from Group 2 contracted a urinary tract infection. In Group 3, five patients exhibited complications and included one with mid-ureteral stone, two with renal hemorrhage, and two with urinary tract infection. CONCLUSION: The estimated blood loss, duration of hospital stay, operative time, number of procedures (to achieve stone-free status), and complications did not statistically differ between the three groups. Moreover very few complications occurred in the different surgical approaches. Therefore, PCNL via all the three approaches were deemed safe and effective.

Single port laparoscopic nephrolithotomy in a double collecting system kidney: the first case reported in Thailand.

The objective of this study is to report the first case in Thailand of a single port laparoscopic nephrolithotomy in a double collecting system of a right kidney. The operation was successfully done in a 49-year-old Thai female presented with a full staghorn kidney stone in the lower moiety of the duplex right kidney. Percutaneous nephrolithotomy was performed first but the removal of the lower calyceal branch and the rest failed because the access tract was lost. Then the residual stones were successfully removed by single port laparoscopic nephrolithotomy. This study proves that single port laparoscopic nephrolithotomy is technically feasible without additional skin incisions.

Laparo-endoscopic single site (LESS) management of benign kidney diseases: evaluation of complications.

BACKGROUND: To present our experience with Laparo-Endoscopic Single Site (LESS) management of benign kidney diseases. MATERIAL AND METHOD: Between September 2008 and November 2009, 18 patients underwent single port transumbilical laparoscopic surgery for nephrectomy for a nonfunctioning kidney (7 cases), cyst decortications for symptomatic renal cyst (10 cases), and redo-dismembered pyeloplasty with previously failed laparoscopic surgical repair (1 case). Patients underwent surgery through a single 2-cm infraumbilical incision with the triport laparoscopic-port. All pathological reports of LESS nephrectomy and cyst decortications confirmed with chronic pyelonephritis and simple cysts, respectively Histology of xanthogranulomotus pyelonephritis showed two cases of the nephrectomy procedure. RESULTS: Mean patient age and BMI were 61 +/- SD 14.2 years and 24.75 +/- SD 11.2 kg/m2, respectively Mean operating time was 187.7 +/- SD 71.4 min. LESS was a possible and safe approach in 77.8% of patients. All LESS cyst decortications and redo-pyeloplasty were completed without major complications or conversion to open surgery. However, there was one case each of LESS cyst decortication and pyeloplasty requiring an additional 3-mm port for suturing due to bleeding and an instrument error. For LESS nephrectomy, two (28.6%) with higher waist circumference were converted to standard laparoscopic nephrectomy due to failure to progress. One post operative complication of incisional hernia occurred in a patient with chronic bronchitis and asthma. CONCLUSION: LESS for the management of benign kidney diseases is an effective and safe treatment option with selected patients and experienced surgeon.

Laparoscopic excision of urachal cysts in elderly men and woman following pregnancy.

BACKGROUND AND OBJECTIVE: Persistent urachus rarely presents in the aging male or during pregnancy. The authors report their experience with the laparoscopic excision of urachal cysts in two elderly men with significant co-morbidities and following pregnancy in a 32-year-old female. MATERIAL AND METHOD: The two male patients (65 and 70 years old, respectively) presented with a lower abdominal mass and umbilical discharge, while persistent urachus was identified incidentally during pregnancy; patients were managed with laparoscopic excision at 4 weeks, 6 weeks, and one year after diagnosis, respectively. Using 3 port accesses, the urachus and medial umbilical ligament were clipped and divided In 2 cases, specimens were separated from the bladder dome with a bladder cuff. In one patient, an additional port was required to facilitate intracorporeal freehand suturing of the bladder defect. RESULTS: All procedures were completed successfully via laparoscopy. No intraoperative or postoperative complications were reported Operative time ranged from 120, 180 and 160 minutes, respectively; in-hospital convalescence was 1, 7, and 6 days, respectively. Pathological evaluation revealed a benign urachal remnant in each case. CONCLUSION: Laparoscopic excision of urachal cysts in the aging male or following pregnancy is safe and effective.

Significance of muscularis mucosae in metastasis involvement of urinary bladder transitional cell carcinoma.

OBJECTIVE: To assess the significance of muscularis mucosae involvement in metastasis of urinary bladder transitional cell carcinoma. MATERIAL AND METHOD: This was a retrospective cohort study of superficial urothelial carcinoma (transitional cell carcinoma). Histopathology and patient records of 192 patients were collected from 1990 to 2004. There were 115 males and 77 females, their age ranged from 43 to 83 years old with an average of 60 +/- 5 years. One hundred cases did not invade muscularis mucosae layer (group A) and 92 cases invaded the muscularis mucosae layer (group B). The histopathology of biopsy or cystectomy specimens for recurrence, progression of the disease and the number of vessels above and below the muscularis mucosae layer of bladder cancer specimens were compared by light microscopic examination with Hematoxylin and Eosin (H&E) and followed by immunoperoxidase desmin stain. RESULTS: The amount per high power field of the blood and lymphatic vessels below muscularis mucosae layer, 9 (6-12), was significantly higher than that above muscularis mucosae layer, 7 (5-10) (p < 0.05). The cancer high grade (grade 3) in group B had also significantly higher percentage than that in group A, 30.4:5.0 (p < 0.05). Moreover, the recurrent rate (recurrent > 2) in group B had also a significantly higher percentage than that in group A, 21.4:4.0 (p < 0.05). CONCLUSION: The present study has confirmed previous findings that not all muscularis mucosae layers (about 50%) were found in the biopsy specimens. The findings of superficial urothelial cancer (no invasion to muscularis propria) invading the muscularis mucosae are a warning sign for invasive tumor that needs more aggressive treatment.

Laparoscopic renal surgery: Ramathibodi Hospital experience.

OBJECTIVE: To report the authors' early experience of laparoscopic renal surgery for benign and malignant renal conditions. MATERIAL AND METHOD: Laparoscopic renal surgery was performed on 24 patients with benign and malignant renal conditions between July 2004 and February 2005. The patient characteristics and perioperative data including operative time, blood loss, analgesic requirement, complications, duration of postoperative drain removal, length of hospital stay, and duration to return to normal activity were all recorded. RESULTS: Laparoscopic simple nephrectomy was performed in 15 patients with nonfunctioning benign renal conditions. Three operations of hand-assisted laparoscopic radical nephrectomy and one of partial nephrectomy were performed for large and small renal cell carcinoma, respectively. Transitional cell carcinomas were managed by retroperitoneoscopic nephrectomy or hand-assisted approach in 3 cases. For a case of severe inflammatory renal condition, hand-assisted approach was used for treatment. Laparoscopic renal cyst decortication was performed in one case. In the laparoscopic simple nephrectomy group, the mean operative time was 126 +/- 38.3 minutes. The median (range) estimated blood loss was 100 (50-500) mL, and one patient required conversion to open surgery because of renal vein injury. In three cases of hand-assisted laparoscopic radical nephrectomy, the operation time was 315, 325 and 150 minutes and the operative blood loss was 500, 1000 and 200 ml, respectively. In cases of hand-assisted laparoscopic partial nephrectomy, the operation time and the operative blood loss were 220 minutes and 350 ml, respectively. In three cases of transitional cell carcinoma, the operation time was 120, 140 and 150 minutes and the operative blood loss was 100, 150 and 150 ml. The surgical margins of all resected specimens for malignant tumors were negative and no major complication was recorded Simple renal cyst decortication was successfully performed within 90 minutes of operation time and bleeding 50 ml. In cases of severe inflammatory renal condition performed by hand-assisted approach, the operative time was 250 minutes and the operative blood loss was 250 ml. CONCLUSION: Laparoscopic renal surgery is a safe and efficacious approach for resection of benign nonfunctioning kidneys and malignant renal tumors.

Comparative study of renal function between standard and modified anatrophic nephrolithotomy by radionuclide renal scans.

OBJECTIVE: To compare the changes in renal function after surgery between standard and modified anatrophic nephrolithotomy using the technetium 99m-DTPA renal scan in patients with complex staghorn calculi. MATERIAL AND METHOD: From July 2001 to March 2002, standard anatrophic nephrolithotomy (sANL) was performed in 7 patients with complex staghorn calculi and modified anatrophic nephrolithotomy (mANL) was performed in another group of 8 patients with the same condition. Preoperative and postoperative renal function were assessed by technetium 99m-DTPA renal scan. RESULTS: Mean patient age was 41 years in the sANL group and 45 years in the mANL group. Male to female ratio was 4:3 in the sANL group and 5:3 in the mANL group. Median operative time was 205 minutes in the sANL group compare with 180 minutes in the mANL group (P = 0.03). Median estimated blood loss was 300 ml. in the sANL group and 275 ml. in the mANL group (P = 0.17). Median percent reduction of GFR on the operated kidney was 9.13 (-30.03 to -3.15) in the sANL group and 27.25 (-41.81 to -1.55) in the mANL group (P = 0.13). Residual small stone was seen in one patient of the sANL group and ESWL was performed for stone fragmentation. There were no serious short-term complications. CONCLUSION: The average operative time of sANL was longer than mANL however, sANL preserved more renal function than mANL. This study suggested that sANL should be the procedure of choice in patients who have compromised renal function.