Radio-frequency ablation helps preserve nephrons in salvage of failed microwave ablation for a renal cancer in a solitary kidney.

Recurrent tumors after renal ablative therapy present a challenge for clinicians. New ablative modalities, including microwave ablation (MWA), have very limited experience in methods of retreating ablation failures. Additionally, in MWA, no long-term outcomes have been reported. In patients having local tumor recurrence, options for surveillance or surgical salvage must be assessed. We present a case to help assess radio-frequency ablation (RFA) for salvage of failed MWA. We report a 63-year-old male with a 4.33-cm renal mass in a solitary kidney undergoing laparoscopic MWA with simultaneous peripheral fiber-optic thermometry (Lumasense, Santa Clara, CA, USA) as primary treatment. Follow-up contrast-enhanced computed tomography (CT) scan was performed at 1 and 4.3 months post-op with failure occurring at 4.3 months as evidenced by persistent enhancement. Subsequently, a laparoscopic RFA (LRFA) with simultaneous peripheral fiber-optic thermometry was performed as salvage therapy. Clinical and radiological follow-up with a contrast-enhanced CT scan at 1 and 11 months post-RFA showed no evidence of disease or enhancement. Creatinine values pre-MWA, post-MWA, and post-RFA were 1.01, 1.14, and 1.17 mg/ml, respectively. This represents a 15% decrease in estimated glomerular filtration rate (eGFR) (79 to 67 ml/min) post-MWA and no change in eGFR post-RFA. Local kidney tumor recurrence often requires additional therapy and a careful decisionmaking process. It is desirable not only to preserve kidney function in patients with a solitary kidney or chronic renal insufficiency, but also to achieve cancer control. We show the feasibility of RFA for salvage treatment of local recurrence of a T1b tumor in a solitary kidney post-MWA.

Oncologic outcomes using real-time peripheral thermometry-guided radiofrequency ablation of small renal masses.

BACKGROUND AND PURPOSE: With the increased incidence of low-stage renal cancers, thermal ablation technology has emerged as a viable treatment option for extirpation in selected persons and is supported by the current American Urological Association guidelines. We present a 9-year, single institution experience with radiofrequency ablation (RFA) using real-time peripheral temperature monitoring of small renal masses focusing on oncologic outcomes. PATIENTS AND METHODS: We reviewed our prospectively collected database of patients with renal masses who were treated between November 2001 and January 2011 with laparoscopic (LRFA) or CT-guided percutaneous RFA (CTRFA) with simultaneous real-time peripheral fiberoptic thermometry. Patients were followed radiographically at 1 month, 6 months, 1 year, and then annually. Clinicopathologic outcomes were collected and analyzed. RESULTS: A total of 274 patients (211 male) aged 18 to 88 years (mean 67 years) with 292 renal tumors underwent LRFA (112) or CTRFA (180). Mean tumor size was 2.5 cm (0.7-5.3 cm). An intraoperative preablation biopsy showed 197 (67.4%) renal-cell carcinomas (RCC), and 77 (26.4%) benign tumors. Mean follow-up was 26 months (1-98 mos). The single ablation treatment radiographic success rate was 96% for all tumors and 94% for RCC. Metastatic RCC developed in one patient, who died. The Kaplan-Meier (KM) 3-year and 5-year cancer-specific survival was 100% and 98.6%, respectively. The KM 3-year and 5-year overall survival was 90.4% and 74.2%, respectively. CONCLUSION: RFA is a clinically effective and safe nephron-sparing treatment of patients with small renal masses. Our large cohort and intermediate-term experience adds to the building evidence for the efficacy of RFA for small renal cancers.

Renal volumetric analysis: a new paradigm in renal mass treatment assessment.

UNLABELLED: Abstract Background and Purpose: Multiple renal volumetric assessment studies have correlated parenchymal volume with the glomerular filtration rate. The objective of this study was to compare renal volumes before and after treatment of renal masses with either partial nephrectomy or radiofrequency ablation (RFA). PATIENTS AND METHODS: We reviewed our prospectively collected database of patients with renal masses who were treated between November 2001 and January 2011 with robot-assisted laparoscopic partial nephrectomy (RALPN), laparoscopic RFA (LRFA), or CT-guided percutaneous RFA (CTRFA). Digital Imaging and Communications in Medicine CT imaging data were analyzed in an open-source viewer. Volumetric calculations were used to measure the normal, enhancing bilateral renal parenchyma and tumor volumes. Normal parenchymal volume loss was compared among treatments. RESULTS: There were 96 patients (68 men) with an average age of 68.0 (36-84) years who met our inclusion criteria. The average tumor diameter, tumor volume, and nephrometry score (NS) was 3.5 cm, 32.0 cm(3), and 7.1 in RALPN (n=26), 2.6 cm, 9.8 cm(3), and 7.1 in CTRFA (n=47), and 2.9 cm, 14.3 cm(3), and 7.2 in LRFA (n=23) groups. The percent change in the operated kidney volume was similar in RALPN (-12%±15), CTRFA (-13%±16), and LRFA (-17%±18) groups. NS was the only variable in a multivariate linear regression model that correlated with the amount of volume lost in the ipsilateral kidney. CONCLUSIONS: Our retrospective volumetric analysis of renal parenchyma before and after partial nephrectomy or RFA of renal masses revealed that all treatments produce similar volume of collateral damage.

Low biopsy volume in ureteroscopy does not affect tumor biopsy grading in upper tract urothelial carcinoma.

OBJECTIVES: Urothelial carcinomas (UC) from the upper urinary tract represent 7%-10% of all kidney malignancies. With current ureteroscopic (URS) techniques, small tissue samples are usually the only available histopathologic material for evaluation, representing a diagnostic challenge. Precision in diagnosis is essential for treatment decision making. There has been much debate as to whether tumor grade and stage found on biopsy agree with final pathology. The purpose of this study is to evaluate whether URS biopsy volume affects tumor grading and staging agreement between biopsy and nephroureterectomy (NU) specimens. MATERIALS AND METHODS: We reviewed 137 URS biopsies in 81 patients with suspected upper urinary tract UC performed from April 2002 to April 2011. Of those, 54 patients had both the URS biopsy and NU performed at our institution and were available for review. Biopsy dimensions were recorded to calculate estimated ellipsoid volume, and 2 urological pathologists independently evaluated histologic grade (ISUP/WHO 2004), (based on pleomorphism and mitosis) and depth of invasion. Statistical analysis was performed to evaluate URS biopsy and NU specimen grade and stage concordance. In addition, univariable and multivariable analyses was performed to assess the effect of biopsy volume on agreement. RESULTS: Of the 54 patients studied, low grade and high grade UC biopsy were found in 8 (15%) and 46 (85%), URS biopsies, respectively. Regarding biopsy stage, 51 (94%), 1 (2%), and 2 (4%) were stage Ta, T1, T2, respectively. Grade concordance was 92.6%, (95% CI: 82.4%-98.0%). Stage concordance was 43% (95% CI: 28.7%-55.9%). Multivariable analysis showed biopsy volume did not affect tumor assessment of grade (P = 0.81) or stage (P = 0.44). CONCLUSIONS: Histologic grade assigned on the URS biopsy sample accurately predicts histologic grade in the resected specimen (92.6%), even when the biopsy volume is small. Grading in URS biopsies provides sufficient information for clinical decision making that is independent of sample volume.

Preoperative patient counseling for diagnostic renal biopsy and complications with renal radiofrequency ablation.

PURPOSE: To identify preoperative factors associated with surgical complications and successful diagnostic renal biopsy in both laparoscopic and percutaneous radiofrequency ablation (RFA) of renal masses in order to help aid in preoperative patient counseling for renal RFA. METHODS: We reviewed our Institutional Review Board approved database from November 2001 to January 2011, containing 335 tumors treated with either laparoscopic (LRFA) or percutaneous RFA (CTRFA). Preoperative patient demographics, tumor characteristics, and intraoperative surgical data were collected along with biopsy results and clinicopathologic outcomes. RESULTS: RFA was performed on 335 renal tumors (124 LRFA, 211 CTRFA). Non-diagnostic biopsy occurred in 18 (5.5%) tumors. Of the 317 procedures performed, 121 complications occurred in 103 (30.7%) procedures. Multivariate analysis only showed CTRFA (vs LRFA) to increase the likelihood of non-diagnostic biopsy (OR 5.1, 95% CI 1.2-22, p = 0.032). Increased tumor size (p = 0.007) and synchronous ablations (p = 0.019) increased the risk for major complications, while decreased surgeon experience (p = 0.003) and tumors close to the collecting system (p = 0.005) increased the risk of any complication. CONCLUSIONS: Preoperative recommendations can be made to patients in the future. We suggest counseling patients that when undergoing RFA, percutaneous approach increases the risk of non-diagnostic biopsy, increased tumor size increases the risk of major complications, having more than 1 tumor ablated increases the risk of a major complication, and tumors close to the collecting system may increase the risk of complications.

Cost comparison of nephron-sparing treatments for cT1a renal masses.

OBJECTIVES: Treatment options for small renal tumors have evolved from radical nephrectomy (RN) to partial nephrectomy (PN), thermal ablation, or active surveillance. With the advancement of techniques, costs differences are unclear. The objective of this study is to compare the 6-month costs associated with nephron-sparing procedures for cT1a renal tumors. MATERIALS AND METHODS: We performed a review of patients diagnosed with a solitary cT1a renal mass who underwent surgical treatment from June 2008 to May 2011. Open partial nephrectomy (OPN), robot-assisted partial nephrectomy (RLPN), laparoscopic radio-frequency ablation (LRFA), or computed tomography guided radio frequency ablation (CTRFA) was performed on 173 patients. Cost data were collected for surgical costs, associated hospital stay, and the 6-month postoperative period. RESULTS: Patients underwent surgery, including 52 OPN, 48 RLPN, 44 LRFA, and 29 CTRFA. Median total costs associated were $17,018, $20,314, $13,965, and $6,475, for OPN, RLPN, LRFA, and CTRFA, respectively. When stratified by approach differences were noted for total cost (P < 0.001), operating room (OR) time (P < 0.001), surgical supply (P < 0.001), and room and board (P < 0.001) in univariable analysis. Multivariable linear regression (R(2) = 0.966) showed surgical approach (P = 0.007), length of stay (P < 0.001), and OR time (P < 0.001) to be significant predictors of total cost. However, tumor size (P = 0.175), and Charlson comorbidity index (P = 0.078) were not statistically significant. CONCLUSIONS: Six-month cost of nephron-sparing surgery is lowest with radio frequency ablation (RFA) by either laparoscopic or computed tomography (CT)-guided approach compared to RLPN and OPN. As oncologic and safety outcomes improve and become comparable in all nephron-sparing surgery (NSS) approaches, cost of each procedure will start to play a stronger role in the clinical and healthcare policy setting.

Salvage robot-assisted partial nephrectomy for the management of renal cell carcinoma following failed stereotactic radiotherapy.

Nephron-sparing surgery is currently the standard of care for the management of small renal masses. While both neoadjuvant and adjuvant conventional external beam radiotherapy have failed to demonstrate an oncologic benefit for the treatment of renal cell carcinoma, more recent work aims to explore the utility of stereotactic radiotherapy. We present the case of a 70-year-old woman who failed primary treatment of a small renal mass with the CyberKnife radiotherapy system and describe her successful salvage treatment with robot-assisted partial nephrectomy. This case demonstrates the safety of robotic surgery for the management of renal tumors following failed stereotactic radiotherapy.

Intravesical methylene blue facilitates precise identification of the diverticular neck during robot-assisted laparoscopic bladder diverticulectomy.

BACKGROUND: The aim of this report is to describe our surgical technique for robot-assisted laparoscopic bladder diverticulectomy. In this technique, methylene blue is instilled into the bladder to aid in intra-abdominal identification of the diverticular neck. SUBJECTS AND METHODS: We retrospectively reviewed the records of patients who underwent robot-assisted bladder diverticulectomy by a single surgeon. RESULTS: Between September 2008 and January 2011, 5 patients successfully underwent robot-assisted laparoscopic bladder diverticulectomy using 1% intravesical methylene blue. All cases were completed without intraoperative complication or need for open conversion. Mean operative time was 216 minutes, with a mean estimated blood loss of 45 mL. Patients were discharged 1-2 days following surgery. No patient experienced a perioperative complication. CONCLUSIONS: The robot-assisted approach for bladder diverticulectomy is a viable alternative to both open and laparoscopic surgery. The use of intravesical methylene blue greatly aids in identification of the diverticular neck during this procedure.

Comparison of safety, renal function outcomes and efficacy of laparoscopic and percutaneous radio frequency ablation of renal masses.

PURPOSE: With the increased incidence of low stage renal cancers, thermal ablation technology has emerged as a viable treatment option. Current AUA (American Urological Association) guidelines include thermal ablation as a treatment modality for select individuals. We compared the laparoscopic and percutaneous approach for the radio frequency ablation of renal tumors under the guidance of urological surgeons. MATERIALS AND METHODS: We reviewed our radio frequency ablation database of patients with renal masses undergoing laparoscopic or computerized tomography guided percutaneous radio frequency ablation with simultaneous peripheral fiberoptic thermometry from November 2001 to January 2011 at a single tertiary care center. Data were collected on patient demographics, and surgical and clinicopathological outcomes stratified by approach. RESULTS: A total of 298 patients with 316 renal tumors underwent laparoscopic (122 tumors) or computerized tomography guided (194 tumors) radio frequency ablation. There were no statistically significant differences between the laparoscopic and computerized tomography guided radio frequency ablation groups with respect to patient demographics, complication rates and renal functional outcomes (p>0.05). The 3-year Kaplan-Meier estimation of radiographic recurrence-free probability was 95% for computerized tomography guided radio frequency ablation and 94% for laparoscopic radio frequency ablation (p=0.84). Subanalysis of the 212 (67%) renal cell carcinoma tumors showed a 3-year Kaplan-Meier estimation of oncologic recurrence-free probability (post-ablation biopsy proven viable tumor) of 94% for computerized tomography guided radio frequency ablation and 100% for laparoscopic radio frequency ablation (p=0.16). Median followup was 21 months for laparoscopic radio frequency ablation) and 19 months for computerized tomography guided radio frequency ablation. CONCLUSIONS: Laparoscopic and computerized tomography guided radio frequency ablation appear safe and effective with statistically equivalent rates of complications and recurrence.

Development and evaluation of a novel cadaveric model for performance of image-guided percutaneous renal tumor ablation.

INTRODUCTION: Thermal ablation is a well established treatment option for the management small renal masses. Increasingly, renal ablation is performed via a percutaneous approach. However, most urologists are not formally trained in image-based deployment of ablation needles. To address this need, we created a novel training model to teach urologists to perform precise and accurate percutaneous needle placement. This teaching model was implemented as part of a recent training course on tissue ablation organized by the American Urological Association. METHODS: Two fresh frozen human cadavers (Anatomic Gifts Registry, Hanover, Maryland) were used in the model. Plumber's Putty (Oatey, Cleveland, Ohio) and nonpitted olives soaked in Isovue (Bracco Dianostics, Inc, New York, New York) were used to create ablation targets. Course participants underwent a tutorial on the computed tomography (CT)-guided deployment of a 19-gauge Yueh Needle (Cook Medical, Bloomington, Indiana) or Cool-tip radio-frequency ablation (RFA) probe (Covidien, Inc, Boulder, Colorado). After each needle placement, a CT scan was performed to assess successful deployment. Participants were then queried regarding their experience. RESULTS: A total of 18 urologists performed needle or radio-frequency ablation probe placement on 2 cadavers. A mean of 3.39 (range 2-5) attempts was required to hit targets. Subjectively, participants noted an increase in confidence performing percutaneous needle deployment. The cadaver laboratory exposed participants to pretreatment planning, tactile feel of needle placement, needle readjustment, and 3-D spatial relationships of a percutaneous approach. CONCLUSIONS: The presented cadaveric model is an effective tool for teaching percutaneous needle placement. All urologists evaluated noted increased confidence in this technique after training on the model.

Radiofrequency ablation (RFA) therapy for renal angiomyolipoma (AML): an alternative to angio-embolization and nephron-sparing surgery.

OBJECTIVES: To show that radiofrequency ablation (RFA) is safe and effective treatment for renal angiomyolipoma (AML). Current treatments to reduce the risk of haemorrhage include tumour extirpation, angio-embolization, or ablative therapy. PATIENTS AND METHODS: Review of our prospective database revealed 15 patients with intraoperative biopsy confirmed renal AML undergoing RFA from February 2002 to March 2010. Patients underwent either laparoscopic or computed tomography (CT)-guided percutaneous RFA using either the Cool-tip™ (Covidien, Inc. Boulder, CO, USA) or RITA™ (Angiodynamics(®), Latham, NY, USA) RFA probe. CT at 1 month, 6 months, 1 year, and annually thereafter. RESULTS: In all, two male and 13 female patients with seven left-sided and eight right-sided tumours with a mean (range) size of 2.6 (1.0-3.7) cm underwent laparoscopic (five) or CT-guided (10) RFA. No intraoperative complications occurred. Minor complications included transient haematuria and intercostals nerve transection. Surgical complications included pneumonia and myocardial infarction. There was no radiographic evidence of persistent AML (CT enhancement) at a mean follow-up of 21 months. CONCLUSIONS: The haemostatic effect of RFA allows renal lesions suspicious for AML to be treated without bleeding complications. Avoids surgical risk of extirpation or embolization. RFA for renal AML is safe and effective.

Application of "cinch/tie" technique to robotic-assisted nephropexy for posterior abdominal wall fixation.

Nephropexy remains standard for symptomatic nephroptosis, and several minimally-invasive techniques have been described. Triangulation sutures placed between the abdominal wall and the renal capsule are often difficult to tie tightly due to the confined working space. We propose a technique modification to fixate the kidney utilizing the da Vinci Surgical System robot and Lapra-Ty absorbable suture clips. Four female patients with symptomatic nephroptosis diagnosed via kidney hypermobility demonstrated on intravenous urography (IVU) underwent robotic-assisted laparoscopic nephropexy (RALNP) from February 2008 to April 2010. After complete mobilization and stripping of perirenal fat, several 0 Vicryl sutures were placed in a "figure of eight" fashion and tied loosely. Subsequently we utilized a Lapra-Ty to tighten the stitch serially and fixate the kidney. The mean age was 46 years (43-52); one patient underwent simultaneous pyeloplasty and one underwent partial nephrectomy in the ipsilateral kidney. There were no intraoperative complications and two postoperative complications, both Clavien grade I. All patients were asymptomatic postoperatively at a mean follow-up of 9.2 months (1-28), and had no evidence of kidney hypermobility on upright IVU or diuretic renal scintigraphy (RS) scan at 6 weeks postoperatively. RALNP is a viable option in the treatment of symptomatic nephroptosis. Secure placement of several "pexing" sutures helps to ensure appropriate security of these itinerant kidneys. Our technique modification corrects kidney hypermobility while improving symptoms related to nephroptosis.

Radiofrequency ablation for treatment of renal tumors: technological principles and outcomes.

Radiofrequency ablation (RFA) is a minimally invasive, energy-based, needle-ablative treatment modality that is currently being used to treat small renal masses (SRMs) and offers advantages over extirpative techniques. RFA treats SRM with heat induced by the tissue impedance to radiofrequency current emitted from a needle probe within the SRM. Currently available RFA systems use either an impedance- or temperature-based treatment algorithm to reach treatment end point while minimizing risk of carbonization. Physical limitations, such as electrical property heterogeneity and convective heat loss due to blood flow, and technical considerations should be addressed when performing RFA. Nonetheless, investigations with intermediate follow-up have demonstrated single-treatment radiographic recurrence-free rates of >90%. Future trends include the use of noninvasive imaging thermometry, electromagnetic targeting and adjuvant techniques.

Improved targeting of radio-frequency ablation probes and thermal sensors: a preliminary investigation of flat-panel CT-guided ablation of renal tumors performed in the cardiac catheterization laboratory.

Flat-panel detector CT (FD-CT) provides cross-sectional CT-images while offering an improved workspace using fluoroscopic guidance for thermal probe placement such as for radiofrequency ablation (RFA) needles and thermal sensors. The purpose of this article is to test the feasibility of FD-CT in the application of renal tumor ablation in a "hybrid operating room" environment. Eleven patients with renal masses diagnosed preprocedurally with contrast-enhanced CT scan underwent core biopsy and simultaneous CT-RFA under general anesthesia with FD-CT guidance in the cardiac catheterization laboratory. Scans were taken preablation for tumor targeting, intermittently for probe placement and guidance of temperature sensors, and postablation. Perioperative and postoperative outcomes, pathologic results, and radiographic follow-up were recorded for each patient. Target temperatures >60°C to guide treatment end point were reached for each tumor periphery. Biopsy pathology showed 6/11 (55%) to be renal-cell carcinoma, and 2/11 (18%) to be benign; 3/11 (27%) had an indeterminate biopsy result. Three Clavien grade I complications occurred. One patient showed evidence of recurrent disease on postoperative CT scan. In our experience, we have found FD-CT-guided ablation of small renal tumors to be feasible using this advanced targeting system.

Initial experience with laparoendoscopic single-site simple nephrectomy using the TransEnterix SPIDER surgical system: assessing feasibility and safety.

PURPOSE: The goal of this report is to describe our initial clinical experience performing a simple nephrectomy with the SPIDER (Single Port Instrument Delivery Extended Reach) laparoendoscopic single-site (LESS) surgical system. PATIENT AND METHODS: One patient with a nonfunctioning kidney secondary to a ureteropelvic junction obstruction underwent a simple nephrectomy through a single incision performed using the SPIDER surgical system. We assessed the technical feasibility, efficiency, and perioperative outcomes. RESULTS: The SPIDER-LESS nephrectomy was performed successfully without additional skin incisions for laparoscopic ports, instrument clashing, or open conversion. Total operative time was 210 minutes with blood loss of 50 mL. The patient experienced no intraoperative or postoperative complications. Pathologic evaluation confirmed atrophic renal parenchyma. CONCLUSIONS: The SPIDER surgical system LESS nephrectomy is feasible and safe. Future refinements of the technology and prospective studies are needed to further optimize its application in urology.

Laparoendoscopic single site nephrectomy with the SPIDER surgical system: engineering advancements tested in a porcine model.

UNLABELLED: Abstract Background and Purpose: The Single Port Instrument Delivery Extended Reach (SPIDER) surgical system was developed for true continuous instrument triangulation during laparoendoscopic single site (LESS) surgery. We present our initial preclinical experience with the SPIDER surgical system during renal surgery. MATERIAL AND METHODS: Bilateral laparoscopic nephrectomies were performed in a live adult porcine animal model using the SPIDER device. A standard surgical approach was used via direct video guidance. RESULTS: The procedure was successfully performed without surgical error or complication. The SPIDER system proved easy to use with only a minimal learning curve. Intracorporeal surgical knots were tied without difficulty using this single site system. CONCLUSIONS: Our initial experience with the SPIDER surgical system during renal surgery is promising. SPIDER allows for true single port instrument triangulation offering a superior operative experience to currently available LESS surgical systems.

Initial experience using microwave ablation therapy for renal tumor treatment: 18-month follow-up.

OBJECTIVES: To assess efficacy and morbidity of microwave ablation (MWA) for small renal tumors in an initial cohort of patients. MWA is a recently introduced thermal needle ablation treatment modality with theoretical advantages compared with radiofrequency ablation, such as greater intratumoral temperatures, lack of a grounding pad, and superior convection profile. However, experience has been limited in the human kidney. METHODS: Ten patients with a single, solid-enhancing renal tumor from June 2008 to November 2008 received laparoscopic or computed tomography-guided percutaneous MWA at a tertiary referral center with ≥14 months of follow-up. MWA was performed using the Valleylab Evident, 915-MHz MWA system at 45 W with intraoperative biopsy before ablation, and peripheral fiberoptic thermometry to determine the treatment endpoints. The patients were followed up with contrast-enhanced computed tomography at 1 month, 6 months to 1 year, and annually to monitor for tumor recurrence. RESULTS: The follow-up duration for the 6 male and 4 female patients (mean tumor size 3.65 cm, range 2.0-5.5; mean age 69.8 years) was 17.9 months. The recurrence rate, defined by persistent enhancement, was 38% (3 of 8). The intraoperative and postoperative complication rate was 20% and 40%, respectively. CONCLUSIONS: MWA resulted in poor oncologic outcomes with a significant complication rate at an intermediate level of follow-up. However, MWA has promising theoretical advantages and should not be discarded. Additional studies should be considered to better understand the microwave-tissue interaction and treatment endpoints for different size renal masses before widespread use.

Laparoscopic and image-guided radiofrequency ablation of renal tumors: patient selection and outcomes.

Multiple modalities exist for the management of small renal tumors, including active surveillance, extirpation (radical nephrectomy and partial nephrectomy), and ablative therapies. Radiofrequency ablation (RFA) is an alternative to extirpative surgery for renal tumors. This article presents the current literature on RFA for renal tumors. We reviewed 28 RFA series in the English literature from 2003 to 2010 to assess patient selection, biopsy, renal outcomes, and oncologic outcomes.

Blockade of the Renin-Angiotensin system improves insulin receptor signaling and insulin-stimulated skeletal muscle glucose transport in burn injury.

Burn injury is associated with a decline in glucose utilization and insulin sensitivity due to alterations in postreceptor insulin signaling pathways. We have reported that blockade of the renin-angiotensin system with losartan, an angiotensin II type 1 (AT1) receptor blocker, improves whole body insulin sensitivity and glucose metabolism after burn injury. This study examines whether losartan improves insulin signaling pathways and insulin-stimulated glucose transport in skeletal muscle in burn-injured rats. Rats were injured by a 30% full-skin-thickness scalding burn and treated with losartan or placebo for 3 days after burn. Insulin signaling pathways were investigated in rectus abdominus muscle taken before and 90 s after intraportal insulin injection (10 U·kg). Insulin-stimulated insulin receptor substrate 1-associated phosphatidylinositol 3-kinase and plasma membrane-associated GLUT4 transporter were substantially increased with losartan treatment in burn-injured animals (59% above sham). Serine phosphorylated AKT/PKB was decreased with burn injury, and this decrease was attenuated with losartan treatment. In a separate group of rats, the effect of insulin on 2-deoxyglucose transport was significantly impaired in burned as compared with sham soleus muscles, in vitro; however, treatment of burned rats with losartan completely abolished the reduction of insulin-stimulated 2-deoxyglucose transport. These findings demonstrate a cross talk between the AT1 and insulin receptor that negatively modulates insulin receptor signaling and suggest a potential role of renin-angiotensin system blockade as a therapeutic strategy for enhancing insulin sensitivity in skeletal muscle and improving whole-body glucose homeostasis in burn injury.

Robotic partial nephrectomy outcomes at a single institution and experience with R.E.N.A.L. nephrometry score.

Partial nephrectomy is the current gold-standard treatment of small renal masses. The articulated instruments of the surgical robot have made the laparoscopic approach more feasible. We present our experience with 50 robot-assisted laparoscopic partial nephrectomy (RALPN) surgeries and attempt to validate a recently reported nephrometry score. From July 2008 to July 2010, 50 (53 planned) elective RALPNs were performed utilizing the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA, USA). All patients had an enhancing renal mass on CT scan pre-operatively. Clinicopathologic, surgical, and renal functional (Cockcroft-Gault formula) outcomes were recorded prospectively and analyzed. Mean tumor size, length of surgery (LS), warm ischemia time (WIT), and nephrometry scores were 3.6 cm (1-8), 303 min (133-610), 29.1 min (11-42), and 6.8 (4-11) respectively. Renal cell carcinoma was found in 39 (78%) patients. When evaluating the nephrometry score, comparison of low, medium, and high complexity tumors for length of surgery, WIT, and estimated blood loss (EBL) showed no difference (p > 0.05). Nearness to the collecting system (N score 1 vs. N score 3) showed increased EBL (195 ml vs. 510 mL, p = 0.005), and location relative to polar lines (L score 1 and L score 2) increased mean LS (265 vs. 359 min, p = 0.02). RALPN is safe and effective. Nephrometry scores are a method of standardizing tumor complexity and can be utilized in comparing tumor cohorts but may not be predictive of intra-operative outcomes.