Adam C. Mues

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.

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.

Quantification of holmium:yttrium aluminum garnet optical tip degradation.

INTRODUCTION Optical laser fibers are utilized to transmit energy to the surface of a stone during holmium:yttrium aluminum garnet (Ho:YAG) laser lithotripsy. During lithotripsy, fiber tip degradation (burn back) can occur. Fiber burn back may diminish fragmentation efficiency, increase operative time, and increase cost because of fiber replacement. We hypothesize that fiber tip degradation (burn back) varies among different commercially available Ho:YAG laser fibers. METHODS Fibers of varying core diameter sizes for Ho:YAG lithotripsy were evaluated from different manufacturers. Fibers were cleaved, stripped, polished, and inspected for tip uniformity. Fibers were initially tested without contact followed by contact testing using artificial Bego stones. Pre- and postcontact energy outputs were measured by energy detector. Distal tip degradation (burn back) was measured by digital micrometer. Testing was performed on two Ho:YAG lasers (Lumenis VersaPulse 100W and Dornier Medilas H20). All fibers were tested while submerged in water. RESULTS No burn back was observed in any fiber tested in still water (without contact). Before and after lithotripsy, a trend existed with fibers demonstrating high burn back and high preablation energy outputs. The majority of these fibers were <300 microm diameter. Conversely, fibers with low burn back showed low preablation energy outputs and were >300 microm diameter. CONCLUSION Fiber burn back and energy transmission varied among the fibers tested. Burn back only occurred during lithotripsy. Burn back may be reduced by fiber selection or using low pulse energy. Fiber burn back may affect the efficiency of fragmentation and contribute to decreased longevity of the fiber.

Comparison of percutaneous and laparoscopic renal cryoablation for small (<3.0 cm) renal masses.

PURPOSE We reviewed our experience with laparoscopic cryoablation (LCA) and percutaneous cryoablation (PCA) in the management of small renal tumors and compared clinical outcomes, short-term oncologic results, and patient complications. PATIENTS AND METHODS A retrospective comparison of two prospectively collected oncologic databases was performed. Ninety patients underwent PCA for 99 lesions and 81 patients underwent an LCA for 97 lesions. Patient characteristics, perioperative data, and tumor characteristics were recorded including age, estimated blood loss, complication rate, tumor size, and tumor pathology. RESULTS Patients in both the PCA and LCA groups had similar demographic and tumor characteristics. The PCA group had two major complications (2%), and the LCA group had three major complications (3.7%) (P = 0.374). In the LCA group, estimated blood loss was associated with tumor location with hilar tumor demonstrating a significantly higher mean blood loss (191 mL) compared with endophytic, mesophytic, and exophytic tumors (70 mL, 71 mL, 73.5 mL), respectively (P = 0.05). Malignancies rated in the PCA and LCA groups were 50.5% and 60.0%, respectively (P < 0.05). In the PCA group, nine (9.1%) patients demonstrated treatment failure with a persistent enhancement in the ablation bed. All nine were treated with a subsequent PCA. One patient had subsequent tumor bed enhancement and underwent an open radical nephrectomy. Treatment failed in three (3.1%) patients in the LCA cohort (incomplete ablation or recurrence). CONCLUSIONS With short-term follow-up, both LCA and PCA are safe and effective treatments for small renal masses. Patients undergoing PCA had a reduced hospital stay and a lower surgical complication rate, albeit with an elevated re-treatment rate. Long-term data is needed to establish long-term oncologic efficacy. Renal function did not significantly change in patients after cryoablation, including patients with a solitary kidney.

Contemporary Experience in the Management of Angiomyolipoma

PURPOSE We review our single center experience in the management of renal angiomyolipoma (AML) in patients who were treated with active surveillance (AS) or invasive treatment protocols. PATIENTS AND METHODS A prospectively evaluated database was reviewed, and we identified 91 patients with the diagnosis of renal AML who presented between June 1985 and February 2009. Patient characteristics, clinical presentation, treatment modalities, and patient outcomes were evaluated. Patients on AS were analyzed for successful completion of the surveillance protocol considering age, symptomatic presentation, and tumor size as potential predictors of invasive treatment. RESULTS A total of 91 patients with AMLs were identified. The mean patient age was 57 years. Seventy-three (83.9%) patients presented incidentally, and 14 (16%) patients were symptomatic at presentation. Forty-five patients were treated with AS, 4 underwent embolization, and 38 patients had extirpative surgery. After a median follow-up of 54.8 months (range 0.2-211.7 mos), there was a mean growth rate of 0.088 cm/year in the group who were treated with AS. AS failed in three patients. Two patients had retroperitoneal bleeding during the observation period, and one patient manifested an expeditious growth rate of 0.7 cm/year and underwent a radical nephrectomy. CONCLUSIONS AML is a renal tumor that usually exhibits a benign course. Surgical removal and embolization are the standard invasive treatment modalities. AS for AMLs is associated with a slow and consistent growth rate (0.088 cm/year), typically has minimal morbidity, and is a reasonable option in selected patients. Symptomatic presentation and size (> 3 cm) are not predictive for necessitating an invasive procedure.

Surgical Decompression is Associated with Decreased Mortality in Patients with Sepsis and Ureteral Calculi

PURPOSE The combination of sepsis and ureteral calculus is a urological emergency. Traditional teaching advocates urgent decompression with nephrostomy tube or ureteral stent placement, although published outcomes validating this treatment are lacking. National practice patterns for such scenarios are currently undefined. Using a retrospective study design, we defined the surgical decompression rate in patients admitted to the hospital with severe infection and ureteral calculi. We determined whether a mortality benefit is associated with this intervention. MATERIALS AND METHODS Patient demographics and hospital characteristics were extracted from the 2007 to 2009 Nationwide Inpatient Sample. We identified 1,712 patients with ureteral calculi and sepsis. Multivariate logistic regression was performed to determine the association between mortality and surgical decompression. RESULTS Of the patients 78% underwent surgical decompression. Mortality was higher in those not treated with surgical decompression (19.2% vs 8.82%, p <0.001). Lack of surgical decompression was independently associated with an increased OR of mortality even when adjusting for patient demographics, comorbidities and geographic region of treatment (OR 2.6, 95% CI 1.9-3.7). CONCLUSIONS Absent surgical decompression is associated with higher odds of mortality in patients with sepsis and ureteral calculi. Further research to determine predictors of surgical decompression is necessary to ensure that all patients have access to this life saving therapy.

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.

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.

Results of kidney tumor cryoablation: renal function preservation and oncologic efficacy

IntroductionChanges in the management of minimally invasive oncologic renal surgery have introduced ablative therapies as the most recent advancement in minimally invasive technology.MethodsThe current evidence-based medicine on the topic of laparoscopic (LCA) and percutaneous (PCA) renal cryoablation was gathered and outlined in this review. The mechanism and surgical approach to performing renal cryoablation as well a focus on the oncologic and renal functional outcomes after cryoablation will be discussed.ResultsAlthough initially recommended only for patients who were at a high surgical risk, presence of a solitary kidney, or in elderly patients, renal cryoablation, has expanded to include the majority of patients being treated for a small (<3.5 cm) renal cortical neoplasm.ConclusionRenal cryoablation has become a viable minimally invasive treatment option for the majority patients diagnosed with a small (≤ 3cm) renal cortical neoplasm. Cryoablation does not seem to impact post-ablative renal function regardless of surgical approach, pre-ablation renal function, or presence of a solitary kidney.

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.