Comparison of temperature change and resulting ablation size induced by a 902-928 MHz and a 2450 MHz microwave ablation system in in-vivo porcine kidneys.

INTRODUCTION: Microwave ablation (MWA) uses heat to ablate undesired tissue. Development of pre-planning algorithms for MWA of small renal masses requires understanding of microwave-tissue interactions at different operating parameters. The objective of this study was to compare the performance of two MWA systems in in-vivo porcine kidneys. METHODS: Five ablations were performed using a 902-928 MHz system (24 W, 5 min) and a 2450 MHz system (180 W, 2 min). Nonlinear regression analysis of temperature changes measured 5 mm from the antenna axis was completed for the initial 10 s of ablation using the power equation ΔT=atb and after the inflection point using an exponential equation. Thermal damage was calculated using the Arrhenius equation. Long and short axis ablation diameters were measured. RESULTS: The average 'a' varied significantly between systems (902-928 MHz: 0.0299 ± 0.027, 2450 MHz: 0.1598 ± 0.158), indicating proportionality to the heat source, but 'b' did not (902-928 MHz: 1.910 ± 0.372, 2450 MHz: 2.039 ± 0.366), signifying tissue type dependence. Past the inflection point, average steady-state temperature increases were similar between systems but reached more quickly with the 2450 MHz system. Complete damage was reached at 5 mm for both systems. The 2450 MHz system produced significantly larger short axis ablations (902-928 MHz: 2.40 ± 0.54 cm, 2450 MHz: 3.32 ± 0.41cm). CONCLUSION: The 2450 MHz system achieved similar steady state temperature increases compared to the 902-928 MHz system, but more quickly due to higher output power. Further investigations using various treatment parameters and precise thermal sensor placement are warranted to refine equation parameters for the development of an ablation model.

Oncologic Efficacy of Radio Frequency Ablation for Small Renal Masses: Clear Cell vs Papillary Subtype.

PURPOSE: Current radio frequency ablation series do not distinguish renal cell carcinoma subtypes when reporting oncologic efficacy. Papillary neoplasms may be more amenable to radio frequency ablation than clear cell carcinoma because they are less vascular, which may limit heat energy loss. We report the long-term outcomes of patients treated with radio frequency ablation for small renal masses by renal cell carcinoma subtype. MATERIALS AND METHODS: The records of patients undergoing radio frequency ablation for small renal masses (cT1a) at 2 institutions from March 2007 to July 2012 were retrospectively reviewed. Patients were included in analysis if they had biopsy confirmed clear cell or papillary renal cell carcinoma histology. Patients had at least 1 contrast enhanced cross-sectional image following radio frequency ablation. Demographic data between tumor subtypes were compared using the paired t-test. Oncologic outcomes were determined by Kaplan-Meier survival analysis and survivor curves were compared with the log rank test. RESULTS: A total of 229 patients met study inclusion criteria. There were 181 clear cell tumors and 48 papillary tumors. Median followup was 33.2 months. There was no difference between tumor groups based on patient age, tumor size or grade, or months of followup. Five-year disease-free survival was 89.7% for clear cell tumors and 100% for papillary tumors (p = 0.041). There was no significant difference in overall survival (88.4% vs 89.6%, p = 0.764). CONCLUSIONS: Radio frequency ablation outcomes seem to be determined in part by renal cell carcinoma subtype with clear cell renal tumors having less favorable outcomes. We hypothesize that this is due to differences in tumor vascularity. Our experience suggests that future tumor ablation studies should consider reporting outcomes based on tumor cell types.

Small renal mass biopsy--how, what and when: report from an international consensus panel.

To discuss the use of renal mass biopsy (RMB) for small renal masses (SRMs), formulate technical aspects, outline potential pitfalls and provide recommendations for the practicing clinician. The meeting was conducted as an informal consensus process and no scoring system was used to measure the levels of agreement on the different topics. A moderated general discussion was used as the basis for consensus and arising issues were resolved at this point. A consensus was established and lack of agreement to topics or specific items was noted at this point. Recommended biopsy technique: at least two cores, sampling different tumour regions with ultrasonography being the preferred method of image guidance. Pathological interpretation: 'non-diagnostic samples' should refer to insufficient material, inconclusive and normal renal parenchyma. For non-diagnostic samples, a repeat biopsy is recommended. Fine-needle aspiration may provide additional information but cannot substitute for core biopsy. Indications for RMB: biopsy is recommended in most cases except in patients with imaging or clinical characteristics indicative of pathology (syndromes, imaging characteristics) and cases whereby conservative management is not contemplated. RMB is recommended for active surveillance but not for watchful-waiting candidates. We report the results of an international consensus meeting on the use of RMB for SRMs, defining the technique, pathological interpretation and indications.

Emerging needle ablation technology in urology.

PURPOSE OF REVIEW: Thermal ablation of urologic tumors in the form of freezing (cryoablation) and heating (radiofrequency ablation) have been utilized successfully to treat and ablate soft tissue tumors for over 15 years. Multiple studies have demonstrated efficacy nearing that of extirpative surgery for certain urologic conditions. There are technical limitations to their speed and safety profile because of the physical limits of thermal diffusion. RECENT FINDINGS: Recently, there has been a desire to investigate other forms of energy in an effort to circumvent the limitations of cryoblation and radiofrequency ablation. This review will focus on three relatively new energy applications as they pertain to tissue ablation: microwave, irreversible electroporation, and water vapor. High-intensity-focused ultrasound nor interstitial lasers are discussed, as there have been no recently published updates. SUMMARY: Needle and probe-based ablative treatments will continue to play an important role. As three-dimensional imaging workstations move from the advanced radiologic interventional suite to the operating room, surgeons will likely still play a pivotal role in the +-application of these probe ablative devices. It is essential that the surgeon understands the fundamentals of these devices in order to optimize their application.

Artificial intelligence in pathologic diagnosis, prognosis and prediction of prostate cancer.

Histopathology, which is the gold-standard for prostate cancer diagnosis, faces significant challenges. With prostate cancer ranking among the most common cancers in the United States and worldwide, pathologists experience an increased number for prostate biopsies. At the same time, precise pathological assessment and classification are necessary for risk stratification and treatment decisions in prostate cancer care, adding to the challenge to pathologists. Recent advancement in digital pathology makes artificial intelligence and learning tools adopted in histopathology feasible. In this review, we introduce the concept of AI and its various techniques in the field of histopathology. We summarize the clinical applications of AI pathology for prostate cancer, including pathological diagnosis, grading, prognosis evaluation, and treatment options. We also discuss how AI applications can be integrated into the routine pathology workflow. With these rapid advancements, it is evident that AI applications in prostate cancer go beyond the initial goal of being tools for diagnosis and grading. Instead, pathologists can provide additional information to improve long-term patient outcomes by assessing detailed histopathologic features at pixel level using digital pathology and AI. Our review not only provides a comprehensive summary of the existing research but also offers insights for future advancements.

Clinical applications of robotic surgery platforms: a comprehensive review.

Robotic surgery has expanded globally across various medical specialties since its inception more than 20 years ago. Accompanying this expansion were significant technological improvements, providing tremendous benefits to patients and allowing the surgeon to perform with more precision and accuracy. This review lists some of the different types of platforms available for use in various clinical applications. We performed a literature review of PubMed and Web of Science databases in May 2023, searching for all available articles describing surgical robotic platforms from January 2000 (the year of the first approved surgical robot, da Vinci® System, by Intuitive Surgical) until May 1st, 2023. All retrieved robotic platforms were then divided according to their clinical application into four distinct groups: soft tissue robotic platforms, orthopedic robotic platforms, neurosurgery and spine platforms, and endoluminal robotic platforms. Robotic surgical technology has undergone a rapid expansion over the last few years. Currently, multiple robotic platforms with specialty-specific applications are entering the market. Many of the fields of surgery are now embracing robotic surgical technology. We review some of the most important systems in clinical practice at this time.

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.

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.

Diagnosis, evaluation and follow-up of asymptomatic microhematuria (AMH) in adults: AUA guideline.

PURPOSE: The purpose of this guideline is to provide a clinical framework for the diagnosis, evaluation and follow-up of asymptomatic microhematuria. MATERIALS AND METHODS: A systematic literature review using the MEDLINE® database was conducted to identify peer reviewed publications relevant to the definition, diagnosis, evaluation and follow-up for AMH. The review yielded 191 evidence-based articles, and these publications were used to create the majority of the guideline statements. There was insufficient evidence-based data for certain concepts; therefore, clinical principles and consensus expert opinions were used for portions of the guideline statements. RESULTS: Guideline statements are provided for diagnosis, evaluation and follow-up. The panel identified multiphasic computed tomography as the preferred imaging technique and developed guideline statements for persistent or recurrent AMH as well as follow-up. CONCLUSIONS: AMH is only diagnosed by microscopy; a dipstick reading suggestive of hematuria should not lead to imaging or further investigation without confirmation of three or greater red blood cells per high power field. The evaluation and follow-up algorithm and guidelines provide a systematic approach to the patient with AMH. All patients 35 years or older should undergo cystoscopy, and upper urinary tract imaging is indicated in all adults with AMH in the absence of known benign causation. The imaging modalities and physical evaluation techniques are evolving, and these guidelines will need to be updated as the effectiveness of these become available. Please visit the AUA website at http://www.auanet.org/content/media/asymptomatic_microhematuria_guideline.pdf to view this guideline in its entirety.

Factors that impact the outcome of minimally invasive pyeloplasty: results of the Multi-institutional Laparoscopic and Robotic Pyeloplasty Collaborative Group.

PURPOSE: We compared laparoscopic and robotic pyeloplasty to identify factors associated with procedural efficacy. MATERIALS AND METHODS: We conducted a retrospective multicenter trial incorporating 865 cases from 15 centers. We collected perioperative data including anatomical and procedural factors. Failure was defined subjectively as pain that was unchanged or worse per medical records after surgery. Radiographic failure was defined as unchanged or worsening drainage on renal scans or worsening hydronephrosis on computerized tomography. Bivariate analyses were performed on all outcomes and multivariate analysis was used to assess factors associated with decreased freedom from secondary procedures. RESULTS: Of the cases 759 (274 laparoscopic pyeloplasties with a mean followup of 15 months and 465 robotic pyeloplasties with a mean followup of 11 months, p <0.001) had sufficient data. Laparoscopic pyeloplasty, previous endopyelotomy and intraoperative crossing vessels were associated with decreased freedom from secondary procedures on bivariate analysis, with a 2-year freedom from secondary procedures of 87% for laparoscopic pyeloplasty vs 95% for robotic pyeloplasty, 81% vs 93% for patients with vs without previous endopyelotomy and 88% vs 95% for patients with vs without intraoperative crossing vessels, respectively. However, on multivariate analysis only previous endopyelotomy (HR 4.35) and intraoperative crossing vessels (HR 2.73) significantly impacted freedom from secondary procedures. CONCLUSIONS: Laparoscopic and robotic pyeloplasty are highly effective in treating ureteropelvic junction obstruction. There was no difference in their abilities to render the patient free from secondary procedures on multivariate analysis. Previous endopyelotomy and intraoperative crossing vessels reduced freedom from secondary procedures.

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.

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.

Polymorphism in the interleukin-1 receptor antagonist gene is associated with serum interleukin-1 receptor antagonist concentrations and postoperative opioid consumption.

BACKGROUND: The interleukin-1 receptor antagonist (IL-1Ra) is the principal determinant of IL-1ß bioactivity within the IL-1 gene cluster, regulating IL-1α and IL-1ß release. This study was designed to determine whether polymorphisms of the IL-1Ra gene (IL1RN) produce clinically measurable differences in serum IL-1Ra concentrations and opioid consumption in the postoperative period. METHODS: Opioid consumption and pain scores were evaluated in 96 patients undergoing a nephrectomy. DNA was extracted from all patients, and the genotypes of IL1RN were determined by polymerase chain reaction amplification of the variable number of tandem repeats of 86 base pairs in intron 2 of IL1RN. The concentrations of serum IL-1Ra concentrations at baseline and at 24 h postoperatively in 58 subjects were measured. RESULTS: Differences in opioid consumption among the three genotype groups (IL1RN*1 homozygotes and *2 and *3 carriers) were statistically significant in the first and second 12-h postoperative periods (P = 0.010). The IL1RN*2 carrier group consumed 43% (95% CI, 38-48%) less opioids in the first 24 h after surgery than the IL1RN*1 homozygote group (P = 0.003). Differences in the serum IL-1Ra concentration among the three genotype groups were statistically significant at 24 h postoperatively (P = 0.003), with IL1RN*2 carriers having the highest serum IL-1Ra concentrations. CONCLUSIONS: The variable number of tandem repeats in intron 2 of IL1RN may contribute to interindividual variations in opioid consumption in the first 24 h after surgery. Patients homozygous for the IL1RN*1 allele have lower concentrations of IL-1Ra and require higher doses of opioids postoperatively than patients carrying at least one IL1RN*2 allele.

Differentiation of oncocytoma and renal cell carcinoma in small renal masses (<4 cm): the role of 4-phase computerized tomography.

PURPOSE: We investigate the use of 4-phase computerized tomography with intravenous contrast to help distinguish oncocytoma from renal cell carcinoma (RCC) in tumors <4 cm. METHODS: We retrospectively identified patients who underwent surgical management for renal tumors <4 cm from 2005 to 2008. Patients who had pre-operative CT evaluation as per our institution's renal mass protocol and had confirmed pathological diagnosis of either oncocytoma or RCC were included in the study. Enhancement readings were obtained for the tumor and the renal cortex using the same slice simultaneously. RESULTS: Our cohort involved 69 patients (46 men, 23 women; mean age 66) who presented with 79 renal masses. Histopathologically 40 were clear cell, 22 papillary, 5 chromophobe RCC and 12 oncocytoma. On the arterial, venous and delayed phase images, oncocytoma showed the highest mean enhancement change, i.e.,546, 396 and 239% followed by clear cell RCC 261, 261 and 174%, chromophobe RCC 147, 127 and 66% and papillary RCC 137, 184 and 118%, respectively. The enhancement pattern differed significantly on comparing oncocytoma with RCC (P < 0.007). The mean percentage contrast excreted at the end of the delayed phase was 33.3, 13.8, 32 and 53% for clear cell, papillary, chromophobe and oncocytoma, respectively. CONCLUSION: The enhancement and washout values in Hounsfield units obtained by multiphasic CT scan aid in distinguishing oncocytoma from the commonly seen subtypes of RCC in renal masses <4 cm. This preliminary study demonstrates that arterial phase enhancement greater than 500% and washout values of greater than 50% are exclusively seen in renal oncocytomas.

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.

Adult renal cell carcinoma with rhabdoid morphology represents a neoplastic dedifferentiation analogous to sarcomatoid carcinoma.

Renal cell carcinoma (RCC) with rhabdoid morphology (RCC-RM) is a recently described variant of RCC, which has an aggressive biologic behavior and poor prognosis, akin to sarcomatoid RCC. The current World Health Organization classification of RCC does not include the rhabdoid phenotype as a distinct histologic entity. The aim of this study is to investigate whether RCC-RM represents a dedifferentiation of a classifiable-type World Health Organization RCC or a carcinosarcoma with muscle differentiation. We reviewed 168 cases of RCC obtained between 2003 and 2008. From these cases, 10 (6%) were found to have areas of classic rhabdoid morphology. Immunohistochemistry for cytokeratin, epithelial membrane antigen, desmin, CD10, and CD117 was performed in each case using the labeled streptavidin-biotin method. Rhabdoid differentiation was identified in association with conventional-type RCC (9) and with unclassifiable-type RCC with spindle cell morphology (1). In all cases, both the rhabdoid and nonrhabdoid tumoral areas were positive for cytokeratin and epithelial membrane antigen and negative for desmin. Cytokeratin positivity in the rhabdoid areas was focal. In cases associated with conventional-type RCC, CD10 was positive in both the rhabdoid and nonrhabdoid foci. CD117 was negative in these tumors. The unclassifiable-type RCC with spindle cell morphology was negative for both CD10 and CD117. The similar immunophenotype between the rhabdoid and nonrhabdoid tumoral foci supports the origin of the rhabdoid cells from the classifiable-type RCC. Areas of rhabdoid morphology do not represent muscle metaplastic differentiation. Renal cell carcinoma with rhabdoid morphology may represent a dedifferentiation of a classifiable-type RCC, similar to that of sarcomatoid differentiation. The recognition of RCC-RM is important as it allows for the inclusion of these high-grade malignancies into a category associated with poor prognosis despite lacking the spindle cell component classically identified as sarcomatoid change.

Renal functional outcomes for tumours in a solitary kidney managed by ablative or extirpative techniques.

OBJECTIVE: To present the renal functional outcomes for patients treated with open partial nephrectomy (OPN) or radiofrequency ablation (RFA) for tumours in a solitary kidney, as renal masses in a solitary kidney present a challenging treatment dilemma. PATIENTS AND METHODS: A retrospective review of institutional databases identified 89 patients with 98 renal tumours in a solitary kidney managed by RFA or OPN under cold ischaemia between January 1997 and September 2007. The choice of therapy was based on patient and surgeon preference, tumour characteristics and comorbidities. Renal function was calculated using the modified Modification of Diet in Renal Disease equation. RESULTS: Outcomes from 47 patients treated by RFA and 42 by OPN were analysed at a median follow-up of 18.1 and 30.0 months, respectively (P = 0.02). The median age (65.9 vs 59.6 years, P = 0.03) and American Society of Anesthesiology score (3.0 vs 2.0, P = 0.01) were both higher in patients treated with RFA. The median tumour size was greater for tumours managed by OPN (3.9 vs 2.8 cm, P = 0.001), while the median preoperative glomerular filtration rate (GFR) was lower in the RFA group (46.5 vs 55.9 mL/min/1.73 m(2) for OPN, P = 0.04). Compared to RFA, patients treated with OPN had a greater decline in GFR at all times evaluated, including soon after the procedure (15.8% vs 7.1%), 12 months after surgery (24.5% vs 10.4%) and at the last follow-up (28.6% vs 11.4%, all P < 0.001). For patients with a pretreatment GFR of > 60 or > 30 mL/min/1.73 m(2), there was a new onset of decline in GFR of <60 and <30 mL/min/1.73 m(2) in none and 7% of patients after RFA, and in 35% and 17% after OPN. CONCLUSION: Ablative techniques, which obviate ischaemic insults, might be a particularly attractive option for managing tumours in solitary renal units at risk of declining function. Renal functional outcomes compare favourably to extirpative surgery using cold ischaemia.

Results of radiofrequency kidney tumor ablation: renal function preservation and oncologic efficacy.

OBJECTIVES: Radiofrequency ablation (RFA) is increasingly finding a place in the treatment of small renal masses (SRM). RFA may be able to provide better renal preservation, while achieving appropriate cancer control. This investigation takes a critical look at pertinent aspects of RFA principles and reviews oncological and renal function outcomes. METHODS: A review of the most current English literature using a PubMed search was done. Oncological and renal function outcomes were reviewed from selected articles published between 2003 and 2009. Oncological outcome was determined by "single treatment" success rate at first follow-up and "After single treatment" success rate after first follow-up. Renal function outcome was determined by either change in creatinine, creatinine clearance, or GFR after RFA. RESULTS: The mean tumor size was 2.5 cm for 16/17 studies. Average mean and median follow-up was 23.3 months in 13/17 studies and 19.8 months for 4/17 studies. "Single Treatment" success rates of 90-100% (average = 97.2%) were noted in 13 studies. Average increase in serum creatinine was +0.14 mg/dL in four studies. Serum creatinine and creatinine clearance change in one solitary kidney study was +11 mmol/L and -8 mL/min., respectively. CONCLUSIONS: RFA is fast emerging as a safe and efficacious treatment for small renal masses. Compared to extirpative treatment options, RFA seems to provide the lowest rate of renal impairment, while providing acceptable rates of tumor ablation. As long-term results emerge, this may become one of the treatment modalities for renal tumors in patients with solitary kidneys and renal impairment.

Contemporary open partial nephrectomy is associated with diminished procedure-specific morbidity despite increasing technical challenges: a single institutional experience.

OBJECTIVE: To review trends in open partial nephrectomy (OPN) at our center, concentrating on patient selection, technique and perioperative complications. METHODS: A comprehensive database was developed by chart review of consecutive patients undergoing OPN for renal masses at our center. Patient selection, technical modifications, perioperative morbidity, and histopathology were compared in patients undergoing OPN between 1992-1999, 2000-2003, and 2004-2008. Complications were divided into procedure-specific (PSCs) and nonspecific medical complications (NMCs). They were graded using the Common Terminology Criteria for Adverse Events (CTCAE), version 3.0. RESULTS: One hundred and sixty-three OPNs were performed. Temporal trends identified include: an increase in the mean patient BMI (p = 0.04), an increase in the percentage of patients with central tumors (p < 0.001), decrease in cold ischemia time (p = 0.045), increasing use of a sequential renal vein clamp (p = 0.03), increasing utilization of tissue sealants (p < 0.001), reduced EBL (p = 0.05), reduced length of stay (p = 0.005), and a decline in PSCs from 16 to 7% (p = 0.002). The incidence of histologically benign tumors declined from 34 to 10% (p = 0.001). Thirty-three (20.2%) patients experienced perioperative complications: 70% were CTCAE grade 1 or 2 adverse events. BMI was the only factor that was found to be associated with the risk of complications on multivariate analysis [odds ratio 1.067, CI 95% (1.002-1.136); p = 0.031]. CONCLUSIONS: Increasingly, OPN is being utilized for a cohort of challenging patients who are overweight and have centrally located tumors. Despite this, the risk of PSCs is low. Patients who are overweight are at increased risk for perioperative NMCs.

A review of methods for hemostasis and renorrhaphy after laparoscopic and robot-assisted laparoscopic partial nephrectomy.

The techniques for management of small renal masses (SRMs) have evolved over the past several years. Radical nephrectomy can lead to an increased risk of chronic kidney disease, and the emphasis is now shifting to nephron-conserving techniques. Partial nephrectomy is now considered a standard of care for the management of SRMs, and laparoscopic techniques are becoming popular because they are minimally invasive. The kidneys are extremely vascular organs, and renal hemorrhage is a major cause of morbidity after laparoscopic partial nephrectomies. Control of bleeding and management of calyceal injuries can be difficult and make the procedure technically challenging. This review looks at the various modalities that are available to reduce bleeding and reviews some advances in the area of hemostatic maneuvers during laparoscopic partial nephrectomies.