Evaluation of the Surgical Margin Threshold for Avoiding Recurrence after Partial Nephrectomy in Patients with Renal Cell Carcinoma

Purpose@#An adequate minimal surgical margin for partial nephrectomy (PN) has not yet been conclusively established. Therefore, we aimed to compare PN recurrence rates according to surgical margin status and to establish an adequate minimal surgical margin. @*Materials and Methods@#We retrospectively studied patients with clinically localized renal cell carcinoma who underwent PN between 2005 and 2014. Surgical margin width (SMW) was assessed for all surgical tissues and divided into three groups: SMW <1 mm, SMW ≥1 mm, and positive surgical margin (PSM). The data were analyzed using the Kaplan-Meier method with log-rank tests and multivariate Cox regression models. @*Results@#Of 748 patients (median age, 55 years; interquartile range, 46–64 years; 220 female), 704 (94.2%) and 44 (5.8%) patients had negative and PSMs, respectively. Recurrence-free survival was significantly lower in patients with PSMs (p<0.001) and was not significantly different between SMW ≥1 mm and <1 mm groups (p=0.604). PSM was a significant predictor of recurrence (hazard ratio: 8.03, 95% confidence interval: 2.74–23.56, p<0.001), in contrast to SMW <1 mm (p=0.680). @*Conclusion@#A PSM after PN significantly increases the risk of recurrence. We discovered that even a submillimeter safety surgical margin may be enough to prevent recurrence. To maximize normal renal parenchyma preservation and to avoid cancer recurrence in renal parenchymal tumor patients, PN may be a safe treatment, except for those with a PSM in the final pathology.

Computed Tomography-Derived Skeletal Muscle Radiodensity Is an Early, Sensitive Marker of Age-Related Musculoskeletal Changes in Healthy Adults

Background@#A decrease in computed tomography (CT)-derived skeletal muscle radiodensity (SMD) reflects age-related ectopic fat infiltration of muscle, compromising muscle function and metabolism. We investigated the age-related trajectory of SMD and its association with vertebral trabecular bone density in healthy adults. @*Methods@#In a cohort of healthy adult kidney donors aged 19 to 69 years (n=583), skeletal muscle index (SMI, skeletal muscle area/height2), SMD, and visceral-to-subcutaneous fat (V/S) ratio were analyzed at the level of L3 from preoperative CT scans. Low bone mass was defined as an L1 trabecular Hounsfield unit (HU) <160 HU. @*Results@#L3SMD showed constant decline from the second decade (annual change –0.38% and –0.43% in men and women), whereas the decline of L3SMI became evident only after the fourth decade of life (–0.37% and –0.18% in men and women). One HU decline in L3SMD was associated with elevated odds of low bone mass (adjusted odds ratio, 1.07; 95% confidence interval, 1.02 to 1.13; P=0.003), independent of L3SMI, age, sex, and V/S ratio, with better discriminatory ability compared to L3SMI (area under the receiver-operating characteristics curve 0.68 vs. 0.53, P<0.001). L3SMD improved the identification of low bone mass when added to age, sex, V/S ratio, and L3SMI (category-free net reclassification improvement 0.349, P<0.001; integrated discrimination improvement 0.015, P=0.0165). @*Conclusion@#L3SMD can be an early marker for age-related musculoskeletal changes showing linear decline throughout life from the second decade in healthy adults, with potential diagnostic value for individuals with low bone mass.

Efficacy and Safety of Robotic Procedures Performed Using the da Vinci Robotic Surgical System at a Single Institute in Korea: Experience with 10000 Cases

PURPOSE: To evaluate the efficacy and safety of robotic procedures performed using the da Vinci Robotic Surgical System at a single institute. MATERIALS AND METHODS: We analyzed all robotic procedures performed at Severance Hospital, Yonsei University Health System (Seoul, Korea). Reliability and mortality rates of the robotic surgeries were also investigated. RESULTS: From July 2005 to December 2013, 10267 da Vinci robotic procedures were performed in seven different departments by 47 surgeons at our institute. There were 5641 cases (54.9%) of general surgery, including endocrine (38.0%), upper (7.7%) and lower gastrointestinal tract (7.5%), hepato-biliary and pancreatic (1.2%), and pediatric (0.6%) surgeries. Urologic surgery (33.0%) was the second most common, followed by otorhinolaryngologic (7.0%), obstetric and gynecologic (3.2%), thoracic (1.5%), cardiac (0.3%), and neurosurgery (0.1%). Thyroid (40.8%) and prostate (27.4%) procedures accounted for more than half of all surgeries, followed by stomach (7.6%), colorectal (7.5%), kidney and ureter (5.1%), head and neck (4.0%), uterus (3.2%), thoracic (1.5%), and other (2.9%) surgeries. Most surgeries (94.5%) were performed for malignancies. General and urologic surgeries rapidly increased after 2005, whereas others increased slowly. Thyroid and prostate surgeries increased rapidly after 2007. Surgeries for benign conditions accounted for a small portion of all procedures, although the numbers thereof have been steadily increasing. System malfunctions and failures were reported in 185 (1.8%) cases. Mortality related to robotic surgery was observed for 12 (0.12%) cases. CONCLUSION: Robotic surgeries have increased steadily at our institution. The da Vinci Robotic Surgical System is effective and safe for use during surgery.

Preoperative Lymphocyte-Monocyte Ratio Ameliorates the Accuracy of Differential Diagnosis in Non-Metastatic Infiltrative Renal Masses

PURPOSE: Distinguishing infiltrative renal cell carcinoma (RCC) from transitional cell carcinoma (TCC) is a challenging issue due to their radiologic similarities. We evaluated systemic inflammatory biomarkers as parameters for distinguishing tumor types. MATERIALS AND METHODS: A computerized search of medical records from November 2005 to October 2015 identified 116 patients with infiltrative renal masses who were difficult to diagnose confirmatively in radiological study. We investigated the diagnostic efficacy among these patients with their preoperative absolute neutrophil counts (ANC), absolute lymphocyte counts (ALC), absolute monocyte counts (AMC), neutrophil-lymphocyte ratio (NLR), and lymphocyte-monocyte ratio (LMR). RESULTS: The infiltrative RCC group demonstrated significantly lower ALC {1449/µL (1140–1896), median [interquartile range (IQR)]} than the TCC group [1860/µL (1433–2342), p=0.016]. LMR [median (IQR)] also was lower in the infiltrative RCC group [2.98 (2.32–4.14) vs. TCC group 4.10 (2.86–6.09); p=0.011]. In subgroup analysis, non-metastatic infiltrative RCC showed lower ALC and LMR and higher NLR than non-metastatic TCC. Within non-metastatic infiltrative renal masses, multivariate logistic regression analysis revealed that younger patient age and lower LMR were associated with infiltrative RCC [odds ratios (OR) 0.874, p=0.024 and OR 0.461, p=0.048, respectively]. Receiver operating characteristic curve analysis showed that younger age and lower LMR were highly predictive of non-metastatic RCC (area under the curve=0.919, p<0.001). CONCLUSION: Age and LMR were significantly different between patients with infiltrative renal mass. These are potential markers for distinguishing between infiltrative RCC and TCC without metastasis.

Adult Kidney Transplantation of Pediatric En bloc Kidneys Using a Partial Bladder Wall / 대한이식학회지

Kidney transplantation is a treatment of choice which improves survival and quality of life for patients with end-stage renal disease. Due to the growing waiting list for kidney transplantation, expansion of the donor pool to use of deceased pediatric kidneys is of critical importance. However, the use of pediatric kidneys has been limited due to concerns about early graft failure, hyperfiltration injury, and technical difficulties. Performing ureteroneocystostomy using small pediatric en bloc kidneys is sometimes difficult due to the small diameter and short length of the ureter in the adult kidney recipient. We hereby report on a partial bladder wall transplantation using pediatric en bloc kidneys. Pediatric en bloc kidneys and partial bladder wall from a 12-month-old female donor who weighed 9.13 kg was transplanted into a 49-year-old male recipient. The urinary tract was reconstructed with a partial bladder wall of the donor. At 12 months post-transplantation, Doppler ultrasonograpy and renogram showed stable graft renal function without urological complications. Pediatric en bloc kidney transplantation with a partial bladder wall can be a safe and feasible surgical technique to reduce urological complications.

Impact of adjuvant chemotherapy in patients with upper tract urothelial carcinoma and lymphovascular invasion after radical nephroureterectomy

PURPOSE: To evaluate the impact of adjuvant chemotherapy (AC) in patients with upper tract urothelial carcinoma and lymphovascular invasion (LVI) after radical nephroureterectomy (RNU). MATERIALS AND METHODS: We retrospectively analyzed the clinical records and clinicopatholgic outcomes of patients (n=552) treated with RNU between 1986 and 2013. Patients treated with neoadjuvant chemotherapy and those for whom LVI status was not recorded were excluded. Patients were divided into two groups according to LVI (n=86) or no LVI (n=256). RESULTS: The study included 344 patients (240 men and 104 women) with a median of 53.9 months of follow-up (range, 1-297 months) after RNU. Tumors were organ confined (T2/N0) in 211 (61.3%) and tumor grade high in 291 (84.6%). AC was administered in 64 patients (18.6%). A total of 280 patients (81.4%) were treated with surgery alone. Patients with LVI tended to be older (p=0.049), have a higher pT stage (pT3/T4, p<0.001), be pN+ (p<0.001), have a high tumor grade (p<0.001), and experience recurrence (p<0.001). In the multivariate analysis, LVI was an independent prognostic factor for cancer-specific survival and overall survival (p=0.002 and p<0.001, respectively). The multivariate analysis demonstrated that in the subgroup of patients with LVI, AC was a significant prognostic factor for cancer-specific survival and overall survival (hazard ratio, 0.51; p=0.027 and hazard ratio, 0.50; p=0.025, respectively). CONCLUSIONS: AC does not seem to reduce mortality in patients with advanced upper tract urothelial carcinoma after RNU. In the subgroup of patients with LVI, AC had a positive impact on cancer-specific survival and overall survival. LVI would be helpful for selecting patients who are appropriate for AC.

Obesity Is Not Associated with Increased Operative Complications in Single-Site Robotic Partial Nephrectomy

PURPOSE: To evaluate the impact of high body mass index (BMI) on outcomes following robotic laparoendoscopic single-site surgery (R-LESS) robotic-assisted laparoscopic partial nephrectomy (RPN). MATERIALS AND METHODS: Data from 83 Korean patients who had undergone robotic partial nephrectomy from 2006 to 2014 were retrospectively analyzed. The subjects were stratified into two groups according to WHO definitions for the Asian population, consisting of 56 normal range (BMI=18.5-24.99 kg/m2) and 27 obese (> or =25 kg/m2) patients. Outcome measurements included Trifecta achievement and the perioperative and postoperative comparison between high and normal BMI series. The measurements were estimated and analyzed with SPSS version 17. RESULTS: Tumor's complexity characteristics (R.E.N.A.L. score, tumor size) of both groups were similar. No significant differences existed between the two groups with regard to operative time (p=0.27), warm ischemia time (p=0.35) estimated blood loss (p=0.42), transfusion rate (p=0.48) renal function following up for 1 year, positive margins (p=0.24) and postoperative complication rate (p=0.34). Trifecta was achieved in 5 (18.5%) obese and 19 (33.9%) normal weight patients, respectively (p=0.14). In multivariable analysis, only tumor size was significantly correlated with the possibility of Trifecta accomplishment. CONCLUSION: Our findings suggest that R-LESS RPN can be effectively and safely performed in patients with increased BMI, since Trifecta rate, and perioperative and postoperative outcomes are not significantly different in comparison to normal weight subjects.

Comparison of computed tomography findings between renal oncocytomas and chromophobe renal cell carcinomas

PURPOSE: To investigate and distinguish the computed tomography (CT) characteristics of chromophobe renal cell carcinoma (chRCC) and renal oncocytoma. MATERIALS AND METHODS: Fifty-one patients with renal oncocytoma and 120 patients with chRCC, diagnosed by surgery between November 2005 and June 2015, were studied retrospectively. Two observers, who were urologists and unaware of the pathological results, reviewed the preoperative CT images. The tumors were evaluated for size, laterality, tumor type (ball or bean pattern), central stellate scar, segmental enhancement inversion, and angular interface pattern and tumor complexity. To accurately analyze the mass-enhancing pattern of renal mass, we measured Hounsfield units (HUs) in each phase and analyzed the mean, maximum, and minimum HU values and standard deviations. RESULTS: There were 51 renal oncocytomas and 120 chRCCs in the study cohort. No differences in clinical and demographic characteristics were observed between the two groups. A central stellate scar and segmental enhancement inversion were more likely in oncocytomas. However, there were no differences in ball-/bean-type categorization, enhancement pattern, and the shape of the interface between the groups. Higher HU values tended to be present in the corticomedullary and nephrogenic phases in oncocytomas than in chRCC. Receiver-operating characteristic curve analysis showed that the presence of a central stellate scar and higher mean HU values in the nephrogenic phase were highly predictive of renal oncocytoma (area under the curve=0.817, p<0.001). CONCLUSIONS: The appearance of a central stellate scar and higher mean HU values in the nephrogenic phase could be useful to distinguish renal oncocytomas from chRCCs.

A Comparative Study of Laparoendoscopic Single-Site Surgery Versus Conventional Laparoscopy for Upper Urinary Tract Malignancies

PURPOSE: The proper indication for laparoendoscopic single-site surgery (LESS) in urology is still under debate, especially for malignant diseases. We compared the perioperative outcomes between LESS and conventional laparoscopy (CL) for upper urinary tract malignancies. MATERIALS AND METHODS: We reviewed the records of 75 patients who underwent radical nephrectomy, nephroureterectomy with bladder cuff excision, or partial nephrectomy with the LESS or CL approach between December 2008 and December 2010. We compared characteristics and perioperative outcomes between patients who underwent LESS or CL. All operations were performed by three surgeons using the transperitoneal approach. RESULTS: For all three surgery types, no differences in patient characteristics, estimated blood losses, transfusion rates, or durations of hospital stay were found between the two groups. No complications were found between the two groups in those who underwent nephroureterectomy with bladder cuff excision; however, significantly more complications were found in the LESS group than in the CL group in those who underwent radical nephrectomy or partial nephrectomy. Most of the complications with LESS radical nephrectomy occurred in the early introduction period of the technique. CONCLUSIONS: No significant differences in perioperative outcomes were found between the LESS and CL groups in those who underwent radical nephrectomy or nephroureterectomy with bladder cuff excision. Therefore, the use of LESS in these cases is expected to expand as surgeons gain more experience with this technique and as other technical advances in laparoscopic instruments occur. However, partial nephrectomy with LESS should be performed restrictively considering the current level of surgical skill.

The Authors Reply: Renal Cell Carcinoma in Kidney Transplant Recipients and Dialysis Patients

No abstract available.

Clinical Implications for Graft Function of a New Equation Model for the Ratio of Living Donor Kidney Volume to Recipient Body Surface Area

PURPOSE: We propose an equation that predicts graft function after kidney transplantation by using donated kidney volume and recipient body surface area (BSA). MATERIALS AND METHODS: Included were 261 cases of living kidney transplantation between 2007 and 2009. Preoperative computed tomography scans were performed and the donated kidney volume was measured by use of a three-dimensional reconstruction program (Ripidia). The estimated glomerular filtration rate (eGFR) was calculated by using the modification of diet in renal disease formula. Donated kidney volume, preoperative renal function, and demographic factors of both donors and recipients were evaluated as predictors. RESULTS: The mean ages of the donors and recipients were 40.8 and 41.6 years, respectively. The mean donated kidney volume and donated kidney volume/recipient BSA ratio were 153.4 mL and 96.9 mL/m2, respectively. Mean preoperative and postoperative 12-month eGFR of recipients were 7.1 and 59.7 mL/min, respectively, and the mean preoperative eGFR of donors was 92.2 mL/min. Donated kidney volume/recipient BSA ratio, donor age, and recipient gender were the significant predictors of eGFR level (p<0.001) and eGFR<45 mL/min at postoperative 12 months (p=0.005, p<0.001, and p=0.006). From the multiple linear regression equation and predicted probability from logistic regression, we could calculate the equation for the ratio of living donor kidney volume to recipient BSA on graft function. CONCLUSIONS: Graft kidney volume/recipient BSA ratio, donor age, and recipient gender were predictors of graft function 12 months after kidney transplantation. Although we are concerned only with the preoperative, this equation model could help physicians to counsel patients concerning their postoperative prognosis and to avoid insufficient volume donations.

Simplified Zero Ischemia in Robot Assisted Partial Nephrectomy: Initial Yonsei Experience

PURPOSE: To evaluate the safety and feasibility of a simplified zero ischemia technique using kidney donor computed tomographic (CT) angiography and conventional laparoscopic bulldog clamps. MATERIALS AND METHODS: We conducted a review of seven robot-assisted partial nephrectomies (RAPNs) performed by a single surgeon from January 2012 to May 2012. Using a simplified protocol of 3-dimentional reconstruction, tertiary arterial branches supplying the tumor were selectively clamped prior to resection. We used conventional laparoscopic bulldog clamps instead of microsurgical vessel clamps. The patients' demographic information, perioperative outcomes, pathologic outcomes and pre- and postoperative renal functions up to 3 months follow-up were analyzed. RESULTS: RAPN were successfully performed for seven complex renal hilar tumors. There were no significant differences in the total operation time, estimated blood loss or postoperative outcomes compared with published literature on standard RAPN. Negative surgical margins were reported in all cases. CONCLUSIONS: We presented a simplified-zero ischemia technique using kidney Donor CT angiography and conventional laparoscopic bulldog clamps. We have also demonstrated its safety and feasibility in patients with complex renal hilar tumors. This modified technique can be easily adopted by most surgeons who are currently performing RAPN.

Complication Rates of the 720 Video-Assisted Minilaparotomy Living Donor Nephrectomies: Supplementing Clavien Classification

PURPOSE: Laparoscopic living donor nephrectomy (LLDN) has been reported to be as safe and effective as open surgery. We systematically evaluated the safety of video-assisted minilaparotomy surgery-living donor nephrectomy (VAMS-LDN) with use of the modified Clavien classification. MATERIALS AND METHODS: We retrospectively analyzed complications in 720 cases of VAMS-LDN conducted in our institute from 2003 to 2010 by use of the modified Clavien classification of surgical complications. RESULTS: The mean age of the donors was 39.3 years (range, 16 to 66 years) and their mean body mass index was 23.3 kg/m2 (range, 15.8 to 36.4 kg/m2). A total of 67 complications occurred (9.3%). Based on the modified Clavien classification, grade 1, 2a, and 2b complications occurred in 49 (6.8%), 16 (2.2%), and 2 (0.3%) of the donors, respectively. Most grade 1 complications involved mild vascular injuries that were immediately repaired with polypropylene sutures during the surgery. These did not cause any postoperative problems. The other grade 1 complications were wound dehiscence, not requiring secondary closure, and wound site pain in 11 (1.5%) and 5 (0.7%) cases, respectively. Grade 2a complications occurred in 16 (2.2%) cases: 9 (1.3%) involved postoperative transfusions and 1 (0.1%) involved a renal fossa hematoma. One grade 2b complication occurred; it was a lymphocele that resolved with placement of a pigtail catheter. No complications classified as grade 2c or worse occurred. CONCLUSIONS: According to the present analysis of complications, VAMS-LDN is a safe procedure with complication rates comparable to those of LLDN as evaluated in previous studies.

Comparison of Video-Assisted Minilaparotomy, Open, and Laparoscopic Partial Nephrectomy for Renal Masses

PURPOSE: Minimally invasive management of small renal tumors has become more common. We compared the results of partial nephrectomy by video-assisted minilaparotomy surgery (VAMS), open, and laparoscopic techniques. MATERIALS AND METHODS: We retrospectively compared clinicopathological, oncological, and functional outcomes in 271 patients who underwent partial nephrectomy for renal tumors at one institution from 1993 to 2007; including 138 by VAMS, 102 by open, and 31 by laparoscopic technique. RESULTS: Mean follow-up was 47.7+/-29.1 months. No statistically significant differences in the three groups were found in tumor size, tumor location, estimated blood loss, complication rate, preoperative glomerular filtration rate (GFR), and GFR at last follow-up. Ischemic time was shorter in the open (26.9 min) and VAMS (29.3 min) groups than in the laparoscopic group (31.0 min, p=0.021). Time to normal diet and hospital stay were shorter in the VAMS (1.8 days and 5.4 days) and laparoscopic (1.8 days and 4.7 days) groups than in the open group (2.4 days and 7.3 days, p=0.036 and p<0.001, respectively). Of 180 patients with cancer, positive surgical margins occurred in 2 of 82 patients (2.4%) in the VAMS group, none of 75 patients in the open group, and 3 of 23 patients (13.0%) in the laparoscopic group (p=0.084). In the VAMS, open, and laparoscopic groups, 5-year disease-free survival was 94.8%, 95.8%, and 90.3% (p=0.485), and 5-year cancer-specific survival was 96.3%, 98.6%, and 100%, respectively (p=0.452). CONCLUSION: Partial nephrectomy using VAMS technique provides surgical, oncologic, and functional outcomes similar to open and laparoscopic techniques.

Clinical Assessment of Follow-Up Cystatin C-Based eGFR in Live Kidney Donors

PURPOSE: We aimed to compare the cystatin C-based estimated glomerular filtration rate (eGFR) and the serum creatinine-based eGFR and to investigate the clinical roles of the cystatin C-based eGFR in assessing the follow-up renal function of kidney donors. MATERIALS AND METHODS: We enrolled 121 healthy kidney donors who underwent live donor nephrectomy between October 2009 and December 2010 in a prospective manner. Serum creatinine and cystatin C were measured preoperatively and were followed after the surgery (1st, 4th, and 7th postoperative day and 1st, 3rd, 6th, and 12th postoperative month). We also compared the sensitivity and specificity of each eGFR method for predicting the development of chronic kidney disease (CKD) after donor nephrectomy. RESULTS: For those who had a Modification of Diet in Renal Disease postoperative day 4 eGFR of less than 60 ml/min/1.73 m2, the probability of developing CKD was 89.0% (Chronic Kidney Disease Epidemiology Collaboration eGFR, 66.0%; Cockcroft-Gault eGFR, 74.0%; cystatin C eGFR, 57.1%). A cystatin C eGFR of below 60 ml/min/1.73 m2 at postoperative day 4 predicted CKD at 6 months with a specificity of 90.3%, which was the highest among the estimation methods used. Cystatin C eGFRs were generally higher than the creatinine-based eGFRs. CONCLUSIONS: We conclude that cystatin C-based estimations of the GFR are helpful for predicting the recovery of renal function in kidney donors and could be added to the follow-up protocol of kidney donors who may develop CKD, especially patients whose immediate postoperative renal function is marginal.

Renal Cell Carcinoma in Kidney Transplant Recipients and Dialysis Patients

PURPOSE: In a group of surgery patients diagnosed with renal cell cancer, those who underwent dialysis were compared with those who received a kidney transplant. MATERIALS AND METHODS: The 43 subjects included in this study were patients who had been undergoing dialysis because of end-stage renal disease or had undergone kidney transplantation. The patients were diagnosed with renal cell carcinoma (RCC) during follow-up and underwent radical nephrectomy from May 1996 to December 2010. Their medical records were retrospectively analyzed as part of the study. RESULTS: In the transplantation group, the renal replacement therapy period averaged 54 months, and the period from transplantation to RCC averaged 119 months (range, 0 to 264 months). In the dialysis group, RCC was observed after an average of 124 months (range, 2 to 228 months) of dialysis, and nephrectomy was then conducted. Acquired cystic kidney disease (ACKD) was found more frequently in the dialysis group, and it had a statistically relevant effect on the occurrence of RCC by comparison with the transplantation group (p<0.01). CONCLUSIONS: Although the incidence rate of ACKD was significantly higher in the dialysis group among patients undergoing surgery for RCC, cancer was found even without ACKD development in some transplant recipients. Considering that the transplant recipients also underwent dialysis, an informative prospective study will be necessary to determine whether other immunosuppressive agents besides ACKD may function as a cancer risk factor.

Surgical Experience with Retroperitoneal Liposarcoma in a Single Korean Tertiary Medical Center

PURPOSE: This is a report of the surgical treatment and prognosis of retroperitoneal liposarcoma (RPLS) in Koreans. MATERIALS AND METHODS: Nineteen patients treated for RPLS between July 1, 1984, and March 31, 2009, were included. Patient demographics, histopathologic subtypes, survival rate, disease recurrence rate and interval, and adjuvant therapy were reviewed and analyzed. RESULTS: Of the 19 patients diagnosed with RPLS, 26.3% presented with well-differentiated RPLS, 10.5% with dedifferentiated RPLS, 15.8% with myxoid/round cell type, and 47.4% with mixed-type liposarcoma. The mean follow-up period was 66.8 months (range, 6 to 165 months). Primary RPLS was treated in 17 patients. Nine patients (52.9%) had recurrent disease, and recurrence developed at a mean of 47.7 months after primary or repeated surgical treatment. The overall survival rate was 84.2% during a mean follow-up of 66.8 months. The 3- and 5-year survival rates were 86.9%, and the 10-year survival rate was 69.5%. The recurrence interval was significantly shorter in recurrent RPLS cases (p=0.023). The mean growth rate of locally recurrent tumors was 0.34 cm per month. CONCLUSIONS: The survival rates reported here were higher than in previous studies. Locally recurrent tumors presented with a low growth rate, which may have contributed to the relatively high survival rate. A high prevalence of mixed-type RPLS was also noted, and its cause and prognosis require further research.

Cost Aspects of Radical Nephrectomy for the Treatment of Renal Cell Carcinoma in Korea: Open, Laparoscopic, Robot-Assisted Laparoscopic, and Video-Assisted Minilaparotomy Surgeries

PURPOSE: This study aimed to comparatively evaluate the cost-effectiveness of four different types of radical nephrectomy (RN) techniques: open, laparoscopic, robot-assisted laparoscopic, and video-assisted minilaparotomy surgery (VAMS). MATERIALS AND METHODS: Among patients who were diagnosed with renal cell carcinoma and underwent RN, 20 patients were selected who received open, laparoscopic, robot-assisted laparoscopic, or VAMS RN between January 2008 and December 2010. Their medical fees were divided into four categories: procedure and operation, anesthesia, laboratory test, and medical supply fees. The medical costs of the patients were also divided into insured and uninsured costs. RESULTS: The total direct cost of VAMS, open, laparoscopic, and robot-assisted laparoscopic RN were 2,023,791+/-240,757, 2,024,246+/-674,859 (p=0.998), 3,603,557+/-870,333 (p<0.01), and 8,021,902+/-330,157 (p<0.01) Korean Won (KRW, the currency of South Koea), respectively. The total insured cost of VAMS, open, laparoscopic, and robot-assisted laparoscopic RN was 1,904,627+/-231,957, 1,798,127+/-645,602 (p=0.634), 3,039,769+/-711,792 (p<0.01), and 899,668+/-323,508 (p<0.01) KRW, respectively. The total uninsured cost of VAMS, open, laparoscopic, and robot-assisted laparoscopic RN was 119,163+/-24,581, 226,119+/-215,009, 563,788+/-487,798 (p<0.01), and 7,122,234+/-56,117 (p<0.01) KRW, respectively. Medical supply fees accounted for the largest portion of the costs and amounted to 33.43% of the VAMS cost. CONCLUSIONS: VAMS RN is as cost-effective as open surgery. Furthermore, it is comparatively more cost-effective than laparoscopic and robot-assisted laparoscopic RN.

Differential Diagnosis of Complex Renal Cysts Based on Lesion Size along with the Bosniak Renal Cyst Classification

PURPOSE: To identify size criteria for complex cystic renal masses that can distinguish renal cell carcinoma from benign cysts supplementing the Bosniak classification. MATERIALS AND METHODS: We reviewed the records of 97 patients who underwent surgery for complex cystic renal masses from January 2001 to April 2010. The pathological results were compared with the lesion sizes measured by preoperative computed tomography and other radiological features (contrast enhancement, irregularities of cyst walls and septa, and calcification) were also obtained for categorization according to the Bosniak renal cyst classification. RESULTS: Malignancy was significantly associated with cyst size (>2 cm), male gender, and younger patient age (<50 years). According to the Bosniak classification, there was no category I cyst, and all 8 category II cysts were benign. However, 3 of 18 (17%) category IIF cysts, 21 of 39 (54%) category III cysts, and 29 of 32 (90%) category IV cysts were malignant. All category IIF cysts were benign in patients older than 50 years of age. CONCLUSION: Many complex cystic renal masses smaller than 2 cm were benign. We suggest that lesion size should be taken into account when formulating treatment plans for complex cystic renal masses.

Palpation Device for the Identification of Kidney and Bladder Cancer: A Pilot Study

PURPOSE: To determine the ability of a novel palpation device to differentiate between benign and malignant tissues of the kidney and bladder by measuring tissue elasticity. MATERIALS AND METHODS: A novel palpation device was developed, mainly composed of a micromotor, a linear position sensor, a force transducer, and a hemisphere tip and cylindrical body probe. Motion calibration as well as performance validation was done. The tissue elasticity of both benign and malignant tissues of the kidney and bladder was measured using this device. A single investigator performed the ex-vivo palpation experiment in twelve kidneys and four bladder specimens. Malignant tissues were made available from partial nephrectomy specimens and radical cystectomy specimens. Palpations for benign renal parenchyma tissue were carried out on nephroureterectomy specimens while non-involved areas in the radical cystectomy specimens were used for benign bladder samples. Elastic modulus (Young's modulus) of tissues was estimated using the Hertz-Sneddon equation from the experimental results. These were then compared using a t-test for independent samples. RESULTS: Renal cell carcinoma tissues appear to be softer than normal kidney tissues, whereas tissues from urothelial carcinoma of the bladder appear to be harder than normal bladder tissues. The results from renal cell carcinoma differed significantly from those of normal kidney tissues (p=0.002), as did urothelial carcinoma of the bladder from normal bladder tissues (p=0.003). CONCLUSION: Our novel palpation device can potentially differentiate between malignant and benign kidney and bladder tissues. Further studies are necessary to verify our results and define its true clinical utility.