Ablative techniques: Radiofrequency and cryotherapy, which is the best?

Over the last decade the widespread use of abdominal axial imaging has led to a significant rise in the number of incidentally discovered renal cortical neoplasms. Among the available treatment options for ablative therapies cryoablation (CA) and radiofrequency ablation (RFA) has established themselves as feasible and viable alternatives to partial nephrectomy (open/laparoscopic/robotic). The purpose of this manuscript is to compare RFA and CA. In order to do so, it is paramount to fully understand the small renal mass dilemma and to have a working knowledge as to how these technologies achieve cellular destruction.

BioGlue surgical adhesive as a thermal reflector during laparoscopic cryoablation: effect on iceball size and ablation zone diameter.

BACKGROUND AND OBJECTIVES: Cryoablation represents an alternative for treating small renal cortical neoplasms (RCN). Previously, we demonstrated that applying BioGlue during cryoablation diminished bleeding and incidentally noted that the iceballs seemed larger than those in controls. We examined the effects of BioGlue as a thermal insulator of cryoablated tissue to determine its effect on iceball size. METHODS: Laparoscopic cryoablation (LCA) was performed in 6 female pigs (24 ablations) by using a single 1.47-mm cryoablation probe. One pole of each kidney was randomly treated with BioGlue prior to ablation, while the contralateral pole was the untreated control. The size of the iceball was measured using laparoscopic ultrasound. The tissue ablation zone was measured grossly after the specimens were harvested. We also documented the amount of bleeding on a subjective scale. RESULTS: There were no differences in the diameters of the iceballs between the BioGlue and control groups when measured with laparoscopic ultrasound (P=.85). Similarly, the ablation zones on gross measurement were not significantly different (P=.47). No difference occurred in the amount of subjective bleeding. CONCLUSIONS: In a porcine model, the application of BioGlue prior to LCA does not appear to increase the size of the iceball generated. No change was observed in the amount of subjective bleeding as a result of using BioGlue.

Post-percutaneous nephrolithotomy systemic inflammatory response: a prospective analysis of preoperative urine, renal pelvic urine and stone cultures.

PURPOSE: Prior studies suggest that renal pelvic urine culture is a more accurate predictor of urosepsis. We prospectively determined the correlation between preoperative bladder urine cultures, intraoperative renal pelvis cultures and stone cultures in patients undergoing percutaneous nephrolithotomy. We also examined post-procedure risk factors for systemic inflammatory response syndrome. MATERIALS AND METHODS: From February 2009 to February 2011 urine samples from the bladder and renal pelvis were collected from patients undergoing percutaneous nephrolithotomy. Extracted stones were also sent for culture analysis. Postoperatively patients were closely monitored for any signs of systemic inflammatory response syndrome. The concordance of urine and stone cultures across different sites was examined. Regression analysis was done to identify clinical variables associated with systemic inflammatory response syndrome. RESULTS: A total of 204 percutaneous nephrolithotomies were done in 198 patients, of whom 20 (9.8%) had evidence of systemic inflammatory response syndrome postoperatively, including 6 (30%) requiring intensive care. The concordance among stone, renal pelvic and preoperative cultures was 64% to 75% with the highest concordance between renal pelvic urine and stone cultures. In a multivariate model multiple access tracts and a stone burden of 10 cm(2) or greater were significant predictors of systemic inflammatory response syndrome postoperatively. CONCLUSIONS: Even appropriately treated preoperative urinary infections may not prevent infected urine at percutaneous nephrolithotomy. Renal pelvic urine and stone cultures may be the only way to identify the causative organism and direct antimicrobial therapy. We recommend collecting pelvic urine and stone cultures to identify the offending organism in patients at risk for sepsis, particularly those with a large stone burden requiring multiple access tracts.

Intrauterine device embedded in omentum of postpartum patient with a markedly retroverted uterus: a case report.

BACKGROUND: The intrauterine device is a popular form of long-acting reversible contraception. Although generally safe, one of the most serious complications of intrauterine device use is uterine perforation. Risk factors for perforation include position of the uterus, force exerted during intrauterine device insertion, postpartum period, and breastfeeding. This case is important and needs to be reported because it highlights the need to assess risk factors for uterine perforation. It adds to the medical literature because it examines the relationship between position of the uterus and the location of uterine perforation. This case report is unusual in that it describes the mechanism and specific location of uterine perforation in relation to the position of the uterus. CASE PRESENTATION: We present a case of an intrauterine device found in the omentum of a 30-year-old white postpartum woman with a significantly retroverted uterus after the intrauterine device threads were not visualized on speculum examination during a 6-week placement check. The intrauterine device was located and removed via laparoscopy without complication. CONCLUSIONS: This case report will be of interest to women's health practitioners because it illustrates the importance of identifying patients with risk factors for uterine perforation, examining the relationship between uterine position and location of perforation. This is especially significant because the true incidence of perforation may be higher than the numbers reported in the literature. There is no specific diagnostic code for uterine perforation and it is unlikely that retrospective studies can accurately identify all cases.

High-fidelity simulation-based team training in urology: evaluation of technical and nontechnical skills of urology residents during laparoscopic partial nephrectomy.

INTRODUCTION: The use of low-risk simulation training for resident education is rapidly expanding as teaching centers integrate simulation-based team training (SBTT) sessions into their education curriculum. SBTT is a valuable tool in technical and communication skills training and assessment for residents. We created a unique SBTT scenario for urology residents involving a laparoscopic partial nephrectomy procedure. MATERIALS AND METHODS: Urology residents were randomly paired with a certified registered nurse anesthetists or an anesthesia resident. The scenario incorporated a laparoscopic right partial nephrectomy utilizing a unique polyvinyl alcohol kidney model with an embedded 3cm lower pole exophytic tumor and the high-fidelity SimMan3G mannequin. The Urology residents were instructed to pay particular attention to the patient's identifying information provided at the beginning of the case. Two scripted events occurred, the patient had an anaphylactic reaction to a drug and, after tumor specimen was sent for a frozen section, the confederate pathologist called into the operating room (OR) twice, first with the wrong patient name and subsequently with the wrong specimen. After the scenario was complete, technical performance and nontechnical performance were evaluated and assessed. A debriefing session followed the scenario to discuss and assess technical performance and interdisciplinary nontechnical communication between the team. RESULTS: All Urology residents (n = 9) rated the SBTT scenario as a useful tool in developing communication skills among the OR team and 88% rated the model as useful for technical skills training. Despite cuing to note patient identification, only 3 of 9 (33%) participants identified that the wrong patient information was presented when the confederate "pathologist" called in to report pathology results. CONCLUSION: All urology residents rated SBTT sessions as useful for the development of communication skills between different team members and making residents aware of unlikely but potential critical errors in the OR. We will continue to use SBTT as a useful method to develop resident technical and nontechnical skills outside of the high-risk operating environment.

Tracking and assessment of technical skills acquisition among urology residents for open, laparoscopic, and robotic skills over 4 years: is there a trend?

BACKGROUND AND PURPOSE: Tracking the progression of technical skill acquisition during urology residency training is an essential yet challenging task that has been mostly based on anecdotal and subjective performance assessment. We evaluated five surgical tasks used at our institution to assess skill acquisition among residents over 4 consecutive years in an effort to determine appropriate skill testing for resident proficiency relative to level of training for future performance testing. METHODS: Urology residents were tested yearly throughout the course of their residency with five surgical tasks in an open, laparoscopic, and robotic format. The five tasks were: (1) rings on a peg, (2) thread the rings, (3) cut the line, (4) hexagonal suturing, and (5) suture and knot tying. Evaluation was performed by a trained instructor to assess quantity and quality of the skill task performance. RESULTS: The highest scores were obtained on all open tasks regardless of training level. Residents performed second best on robotic and lowest on the laparoscopic skill tasks. The score difference among surgery platforms was statistically significant P<0.0005 across all tasks. It was Tasks 2 and 5, however, that showed a statistically significant difference in overall quantity×quality score between different postgraduate year (PGY) residents (P=0.03 and P=0.02). In addition, the quantity score for Task 5 also showed a statistically significant difference among PGY residents (P=0.04). There was no statistically significant difference in time to perform tasks among PG years. CONCLUSIONS: The high-level Tasks 2 and 5 were the most useful in differentiating different levels of skill task competency among urology residents and appear to be most useful in assessing the degree of improvement among residents during training. These tasks have subsequently been worked into our institution's testing curriculum.

Is LESS really more?

In the last decade, laparoendoscopic single-site surgery (LESS) has been touted to be the part of the 'evolution' of minimally invasive surgery. The hope is that reduced access points will ultimately decrease pain, morbidity, convalescence, and improve cosmesis. However, what is unique about LESS is that while laparoscopic literature sought to demonstrate superiority of the technique over that of open surgery, the publications on LESS generally seem to seek to demonstrate equivalence with laparoscopy, with the major focus being on cosmesis. Unfortunately, even in that regard the objective cosmesis data is lacking. Furthermore, patients rate cosmesis the least important of all factors. LESS has also been associated with increased risk of complication, increased surgical cost, and longer operative times. In the current review, an objective assessment of the literature will be used for comparison between current standard laparoscopic techniques and LESS with the hopes of answering the question: is LESS really more?

Validation, correlation, and comparison of the da Vinci trainer(™) and the daVinci surgical skills simulator(™) using the Mimic(™) software for urologic robotic surgical education.

PURPOSE: Virtual reality simulators with self-assessment software may assist novice robotic surgeons to augment direct proctoring in robotic surgical skill acquisition. We compare and correlate the da Vinci Trainer™ (dVT) and da Vinci Surgical Skills Simulators (dVSSS) in subjects with varying robotic experience. MATERIALS AND METHODS: Students, urology residents, fellows, and practicing urologists with varying robotic experience were enrolled after local institutional review board approval. Three virtual reality tasks were preformed in sequential order (pegboard 1, pegboard 2, and tubes)-initially on the dVSSS and then on the dVT. The Mimic™ software used on both systems provides raw values and percent scores that were used in statistical evaluation. Statistical analysis was performed with the two-tailed independent t-test, analysis of variance, Tukey, and the Pearson rank correlation coefficient where appropriate. RESULTS: Thirty-two participants were recruited for this study and separated into five groups based on robotic surgery experience. In regards to construct validity, both simulators were able to differentiate differences among the five robotic surgery experience groups in the tubes suturing task (p≤0.00). Sixty-seven percent (4/6) robotic experts thought that surgical simulation should be implemented in residency training. The overall cohort considered both platforms easy to learn and use. CONCLUSIONS: Although performance scores were less in the dVT compared with the dVSSS, both simulators demonstrate good content and construct validity. The simulators appear to be equivalent for assessing surgeon proficiency and either can be used for robotic skills training with self-assessment feedback.

The effect of extralumenal safety wires on ureteral injury and insertion force of ureteral access sheaths: evaluation using an ex vivo porcine model.

OBJECTIVE: To evaluate the effect that a safety wire (SW) had on insertion force and direct ureteral trauma using ureteral access sheaths (UAS) in an ex vivo porcine model. MATERIAL AND METHODS: UASs were advance into 20 fresh ex vivo porcine kidney-ureters, either with or without SWs. The average and max force of insertion were recorded. Retrograde saline injection was used to identify the presence of lacerations. RESULTS: For SW vs no SW, the mean insertion force (1.79 vs 0.67, P = .0003, respectively) and max insertion force (2.29 kg vs 1.00, P = .0007) was greater in the SW group. There were 9 lacerations, 6 of which were partial and 3 complete. Of the partial injuries, 2 were in the no SW group and 4 were in the SW group. Of the complete lacerations, 2 occurred in the no SW group and 1 in the SW group. However, there was no significant difference in the total number of lacerations (P = 1.00), the number of partial lacerations (P = .628), or the number of complete lacerations (P = 1.00) between the 2 groups. CONCLUSIONS: The use of an SW significantly increases the force required to insert a UAS; however, it does not appear to affect the force or the degree of ureteral injury.

Retrospective comparison of laparoscopic partial nephrectomy versus laparoscopic renal cryoablation for small (<3.5 cm) cortical renal masses.

OBJECTIVE: We compared perioperative and short-term outcomes of renal laparoscopic partial nephrectomy (LPN) and laparoscopic cryoablation (LCA) in patients with small (<3.5 cm) renal cortical neoplasms. METHODS: A retrospective analysis from our prospectively established database was performed. We identified 92 patients with 95 lesions treated with LPN and 75 patients with 91 lesions treated with LCA. RESULTS: The LPN and LCA groups were comparable in mean tumor size and preoperative and postoperative creatinine level (P=.495, P=.953, and P=.101) respectively. Patients undergoing LPN were younger in age (58.8 versus 69.2 years, P<.001), had a higher mean estimated blood loss (168.4 versus 6 mL, P=.005), and had a prolonged mean operative time (151.6 versus 128.6 minutes, P=.01). Six complications occurred in the LCA group and 11 in the LPN group. The median follow-up time was 21.8 months for LPN and 14 months for LCA (P<.001). Two recurrences were detected in the LCA group, and 1 recurrence was reported after LPN. CONCLUSIONS: In the treatment of small renal cortical neoplasms with short-term follow-up, LPN and LCA seem to be equally effective. LCA offers decreased blood loss, shorter operative time, and less morbidity. Longer follow-up is required to establish oncologic efficacy.

Nonischemic laparoscopic partial nephrectomy using a novel wet monopolar device in a porcine model.

BACKGROUND AND PURPOSE: Laparoscopic partial nephrectomy (LPN) is the minimally invasive standard of care for the management of a cT(1a) renal mass. We evaluated a novel saline enhanced electrosurgical resection (SEER) device for performance of a nonischemic LPN. MATERIALS AND METHODS: Six pigs were used in a nonsurvival pilot study. Energy penetration was characterized by applying the SEER to the lower pole of each kidney for 30 seconds, 1 minute, and 3 minutes using pure cutting energy at 100W and a drip rate of 1 drip per second. Energy testing was performed with the hilum clamped in six kidneys and without clamping in six kidneys. Subsequently, a nonischemic upper pole LPN was performed with the SEER device, and the kidneys were harvested. The areas of necrosis were sectioned and stained with hematoxylin and eosin. Depth of necrosis was visualized grossly and microscopically for each time point. We also recorded time to perform LPN, estimated blood loss (EBL), and subjective severity of bleeding. RESULTS: The average operative time was 15.4 minutes. The mean EBL was 44.2 mL with nine (75%) cases classified as minimal, 2 (17%) moderate, and 1 (8%) severe bleeding. The mean depth of necrosis on the kidney remnants was 2.97 mm. The mean depth of necrosis for unclamped kidneys at 30 seconds, 1 minute, and 3 minutes was 0.38 mm, 0.88 mm, and 1.27 mm, respectively. The mean depths for the clamped kidneys were 2.73 mm, 3.23 mm, and 8.68 mm respectively. Depth of necrosis was significantly higher in the clamped kidneys at 3 minutes (P=0.0035). CONCLUSIONS: In the porcine model, the SEER transected parenchyma and collecting system with low resection times and minimal blood loss. Use of coagulation during resection is the main advantage of a monopolar resection compared with cold scissors. Testing performed for 3 minutes during hilar clamping demonstrated a significantly deeper level of necrosis.

Independent diagnostic and post-treatment prognostic models for prostate cancer demonstrate significant correlation with disease progression end points.

BACKGROUND AND PURPOSE: A major advance in the standard practice of tissue-based pathology is the new discipline of systems pathology (SP) that uses computational modeling to combine clinical, pathologic, and molecular measurements to predict biologic activity. Recently, a SP-based prostate cancer (PCa) predictive model for both preoperative (Px+) and postoperative (Px) prostatectomy has been developed. The purpose of this study is to calculate the percent agreement and the concordance between the Px+ and Px end points. PATIENTS AND METHODS: Fifty-three patients underwent robot-assisted prostatectomy for PCa, and had Px+ and Px testing performed. Data were collected on Px+ end points and Px end points along with pathologic specimen results. The percent agreement and the degree of correlation between the Px+ and Px end points were then calculated. RESULTS: The percent agreement (PA) between Px+ end points and Px end points ranged from 77% to 87%. The PA between a high Px+ favorable pathology (FP) classification and dominant Gleason score ≤ 3 and Gleason sum ≤ 6 was 71.7% and 37.4%, respectively. On univariate analysis, Px+ disease progression (DP) score significantly correlated with Px prostate-specific antigen recurrence (PSAR) score (P<0.001), while Px+ DP probability significantly correlated with PxPSAR probability (P<0.001). Px+ FP probability significantly correlated with postprostatectomy dominant Gleason grade ≤ 3 (P<0.001) and Gleason sum (P<0.001). CONCLUSION: The PA between Px+ and Px testing end points for radical prostatectomy patients was very good. Furthermore, there was a direct correlation between most Px+ and Px end points. While the Px+FP classification and Gleason sum demonstrated a poor PA, Px+FP score still maintained a direct correlation to prostatectomy Gleason sum.

Genitourinary exam skills training curriculum for medical students: a follow-up study of comfort and skill utilization.

PURPOSE: We developed a genitourinary skills training (GUST) curriculum for incoming third year medical students (MS3) and performed a follow-up study of comfort with and utilization of these skills. MATERIALS AND METHODS: GUST consisted of a didactic lecture followed by skills sessions including standardized patient testicular examination (TE) and digital rectal examination (DRE), male and female Foley catheter (MFC and FFC) placement training, suture-knot tying, and a faculty-directed small group learning session. Precourse and postcourse, and 6 and 18 months after the course, MS3 rated comfort with each skill (Likert scale 0-5), and quantified skill usage. Results were compared with 4th year students (MS4) who had not undergone GUST. RESULTS: Participants were 281 MS3 GUST students and 44 MS4. Post-GUST, mean comfort on a Likert scale (0=uncomfortable) increased for all four skills (88.2%-96.9% vs 8.3%-18.5%, P<0.0001). This was maintained at the 6-month and 18-month follow up time points (P<0.0001). At 18 months, MS3 trended toward higher comfort with TE compared with MS4 (74 vs 54%, P=0.068), while with the other skills, both groups showed equal comfort. MS4 learned exam skills from faculty and MFC and FFC from nurses on the wards. Eleven percent of MS4 were never formally taught TE or DRE. MS3 and MS4 performed TE and/or DRE on <8% of newly admitted patients. CONCLUSIONS: MS3 described improved comfort with the GU skills at all time points during follow-up. This was particularly important because both MS3 and MS4 reported using their skills infrequently during their clinical training years.

Clinical, pathologic, and functional outcomes after nephron-sparing surgery in patients with a solitary kidney: a multicenter experience.

BACKGROUND AND PURPOSE: Surgical management of a renal neoplasm in a solitary kidney is a balance between oncologic control and preservation of renal function. We analyzed patients with a renal mass in a solitary kidney undergoing nephron-sparing procedures to determine perioperative, oncologic, and renal functional outcomes. PATIENTS AND METHODS: A multicenter study was performed from 12 institutions. All patients with a functional or anatomic solitary kidney who underwent nephron-sparing surgery for one or more renal masses were included. Tumor size, complications, and recurrence rates were recorded. Renal function was assessed with serum creatinine level and estimated glomerular filtration rate. RESULTS: Ninety-eight patients underwent 105 ablations, and 100 patients underwent partial nephrectomy (PN). Preoperative estimated glomerular filtration rate (eGFR) was similar between the groups. Tumors managed with PN were significantly larger than those managed with ablation (P<0.001). Ablations were associated with a lower overall complication rate (9.5% vs 24%, P=0.01) and higher local recurrence rate (6.7% vs 3%, P=0.04). Eighty-four patients had a preoperative eGFR ≥60 mL/min/1.73 m(2). Among these patients, 19 (23%) fell below this threshold after 3 months and 15 (18%) at 12 months. Postoperatively, there was no significant difference in eGFR between the groups. CONCLUSIONS: Extirpation and ablation are both reasonable options for treatment. Ablation is more minimally invasive, albeit with higher recurrence rates compared with PN. Postoperative renal function is similar in both groups and is not affected by surgical approach.

Laparoscopic ablation of renal neoplasms.

As a result of the widespread application of cross sectional imaging, there has been a significant rise in the incidence of small renal cortical neoplasms. The current standard of care in the management of these lesions is nephron-sparing extirpative surgery. In the last decade, however, image-guided or ablative therapies have garnered significant attention as nephron-sparing alternatives to partial nephrectomy. Although initially laparoscopic ablation was predominately intended for use as active treatment in those patients in whom more invasive therapy was contraindicated, as experience with laparoscopic ablation has become more robust, the indications for the procedure continue to evolve. The current article reviews the indications and contraindications, preoperative preparation, surgical technique, and postoperative follow-up for laparoscopic ablative procedures. Also discussed are techniques and patient selection criteria to avoid complications, as well as the management of complications that do occur.

Polyglyconate unidirectional barbed suture for posterior reconstruction and anastomosis during robot-assisted prostatectomy: effect on procedure time, efficacy, and minimum 6-month follow-up.

BACKGROUND AND PURPOSE: With widespread implementation of posterior rhabdosphincter reconstruction (RSR) followed by urethrovesical anastomosis (UVA), reconstruction has become a significant portion of robot-assisted laparoscopic prostatectomy (RALP). Successful anastomosis can be measured by time for reconstruction and the absence of urinary leak. We prospectively evaluated the experience of a single surgeon (KKB) in using the V-Loc™ wound closure device for the posterior RSR and UVA, and compared it with a standard reconstruction and anastomosis. PATIENTS AND METHODS: A total of 84 patients divided into two groups underwent RALP, undergoing RSR and UVA using a Van Velthoven technique with the V-Loc or with a standard 3-0 monofilament suture. The primary end point was the time to complete RSR, UVA, and the total reconstruction. As a secondary end point, the clinical evidence of an anastomotic leak was also documented. RESULTS: The mean RSR, UVA, and total times were 9, 18, and 27 minutes for the control group, and 6, 12 and 18 minutes for the V-Loc group, respectively. The time differences between the two groups for RSR, UVA, and total time were 3 minutes (P<0.01), 6 minutes (P<0.01), and 9 minutes (P<0.001), respectively. There was no clinical evidence of anastomotic leak in either group. Continence recovery was equivalent between the groups at 6 weeks and 6 months. At a 9-month follow-up, no patients in either group had a clinical UVA stricture necessitating intervention. CONCLUSIONS: The V-Loc suture is associated with a significantly shorter time for the RSR and UVA compared with the traditional suture and is not associated with a higher incidence of clinical urinary leak; however, a larger randomized study with long-term follow-up is necessary to confirm these results.

BioGlue iceball stabilization to minimize the risk of hemorrhage during laparoscopic renal cryoablation.

OBJECTIVE: To evaluate the application of a BioGlue adhesive shell to minimize iceball fracture. Iceball fracture and hemorrhage is common with laparoscopic cryoablation (LCA) of larger (>4 cm) renal tumors. METHODS: Twenty large iceballs were created in porcine kidneys using 3 cryoablation probes in a nonsurvival study. Each kidney underwent an upper and lower pole ablation. One pole in each kidney was covered with 5 mL of BioGlue and the opposite pole served as a control. A double freeze-thaw cycle was performed (10 minutes freeze and 5 minutes active thaw) in both renal poles simultaneously. The probes were removed and the sites were monitored for 20 minutes under direct vision. Fracture length (mm), severity of fracture depth, severity of bleeding (absent, mild, moderate, severe), and estimated blood loss (EBL) (mL) were recorded. RESULTS: In the control group, the mean fracture length was 1.9 mm (range, 0-3 mm). Blood loss was absent in 10%, mild in 60%, and moderate in 30% of ablations. The mean EBL was 20.5 mL (range, 0-50 mL). For the BioGlue ablations, there were no parenchymal fractures. Blood loss was mild in 30% and absent in 70% of sites with an average EBL of 5 mL (range, 0-20). Two bleeding sites occurred as a result of subcapsular hematomas caused by initial probe placement. CONCLUSIONS: BioGlue application minimized the frequency and magnitude of renal fracture. EBL was lower with BioGlue application and most sites demonstrated no postablation bleeding. Further clinical study of the BioGlue shell should be performed to confirm these results.

Active surveillance of renal cortical neoplasms: a contemporary review.

INTRODUCTION: Over the past 2 decades, there has been a significant increase in the number of incidentally found small renal cortical neoplasms (RCNs). As more RCNs are being discovered in the elderly and infirmed patient populations, there has been a growing interest in the role of active surveillance (AS). Active surveillance is recommended for high surgical-risk patients and those with a reduced life expectancy. It is also an option for patients wishing to avoid surgery. We review the current literature on AS and highlight the natural history of disease, the important factors to evaluate during AS, and the contemporary role of biopsy. METHODS AND MATERIALS: The MEDLINE database was searched using PubMed. Search terms included active surveillance, renal mass, natural history, and renal mass histology. From 1966 to present, 17 AS series were identified, all of which have been included in this summary. A summary was performed by compiling all available data and performing a weighted mean where applicable. RESULTS: Initial tumor size does not correlate with growth rate or malignancy. The mean growth rate in large published series is low (0.28-0.34 cm/year). Tumors with high growth rates usually represent malignant lesions and typically undergo delayed intervention. Progression to metatatic disease is a low-probability event for tumors on AS (1.4%); however, this is still a risk that patients must be willing to accept. Larger tumors (cT1b and cT2) also demonstrate relatively low growth (0.57 cm/year); however, these tumors should be monitored carefully. Tumors followed for > 5 years demonstrate a low growth rate (0.15 cm/year), will not likely require intervention, and have a low chance of progression to metastatic disease. CONCLUSION: For highly selected patients with RCN, AS is a reasonable treatment option. Age, surgical risk, comorbidities, and patient opinion must all factor into the final decision when considering a patient for AS.

Pilot study evaluation of standard laparoscopic suturing and a novel parenchymal apposition mechanism for minimally invasive renal reconstruction.

OBJECTIVES: The most technically demanding portion of a laparoscopic partial nephrectomy is the renorrhaphy. The purpose of this study was to determine whether a parenchymal apposition mechanism (PAM) device would be as effective as standard laparoscopic technique (SLT) with respect to efficiency, capability, and safety of renal defect closure. MATERIALS AND METHODS: In this pilot study, participants were recruited to perform surgical reconstruction of a standardized renal parenchymal defect with both SLT and the PAM. The PAM prototype was engineered using two salmon egg hooks connected by absorbable suture and placed within a V-shaped foam delivery mechanism. After hook placement, tensioning of the connecting suture using a Weck clip apposed the defect edges. Each participant performed a single closure with SLT and with the PAM device of a standardized defect in ex vivo porcine kidneys. Closure time, tissue trauma/damage during closure, and the intraparenchymal pressure were recorded. RESULTS: A total of 13 subjects, 7 medical students, 3 residents, 2 fellows, and 1 attending were enrolled. There was no statistical difference between the two methods of closure in average time for closure. In a subgroup analysis of subjects who had performed laparoscopic reconstructive procedures as the primary surgeon, SLT was significantly faster than PAM (P=.036). Mean pressures achieved in attempted closure using SLT and PAM were not significantly different (0.38 N for both groups; P=.99). The mean parenchymal trauma rating was not significantly different between the groups; however, the upper limit of the range of trauma ratings was greater in the standard closures. CONCLUSION: This pilot study demonstrated the feasibility of PAM use in an ex vivo porcine kidney model. Additional testing and continued design modifications are necessary to explore its use in laparoscopic reconstruction of the kidney and other organs.

Validating the use of the Mimic dV-trainer for robotic surgery skill acquisition among urology residents.

OBJECTIVE: To compare robotic surgery skill acquisition of residents trained with Mimic dVTrainer (MdVT) and da Vinci Surgical System (dVSS) console. No standardized curriculum currently exists for robotic surgical education. The MdVT is a compact hardware platform that closely reproduces the experience of the dVSS. METHODS: Sixteen urology trainees were randomized into 3 groups. A baseline evaluation using dVSS was performed and consisted of 2 exercises requiring endowrist manipulation (EM), camera movement and clutching (CC), needle control (NC), and knot-tying (KT). Groups 1 and 2 completed a standardized training curriculum on MdVT and dVSS, respectively. Group 3 received no additional training. After completion of the training phase, all trainees completed a secondary evaluation on dVSS consisting of the same exercises performed during baseline evaluation. RESULTS: There was no difference in baseline performance scores across the 3 groups. Although Group 3 showed no significant improvement in EM/CC domain (P = .15), Groups 1 and 2 had statistically significant improvement in EM/CC domain (P = .039 and P = .007, respectively). The difference in improvement between Groups 1 and group 2 was not statistically different (P = .21). Only Group 2 trainees showed significant improvement in the NC and KT domains during secondary evaluation (P = .02). CONCLUSION: Curriculum-based training with MdVT or dVSS significantly improves robotic surgery aptitude. Similar improvements are seen for exercise domains shared between MdVT and dVSS groups. Follow-up studies are necessary to assess the efficacy of MdVT over a wider spectrum of domains.