Robot-assisted partial nephrectomy: analysis of the first 100 cases from a single institution.

Robot-assisted partial nephrectomy (RAPN) is an alternative to open and laparoscopic partial nephrectomy for small renal tumors. Our objectives were to report our experience and short-term outcomes from the first 100 cases of robot-assisted partial nephrectomy (RAPN) performed at a single institution, as well as to evaluate the effect of the learning curve and identify any factors associated with adverse perioperative outcomes. Patient records of the first 100 RAPN cases performed by three surgeons between October 2007 and March 2010 were retrospectively reviewed. The cases were divided into two groups to analyze a possible learning curve effect. Group 1 consisted of the first half (chronologically) of the cases performed by each surgeon, and Group 2 consisted of the second half. For the entire series, the median warm ischemia time was 24 min (range 11-49), mean length of follow-up was 13.4 months, and the median postoperative change in glomerular filtration rate (GFR) was -6.6 mL/min/1.73 m(2). Three patients had microscopically positive margins on final pathology, three intraoperative complications occurred, and 13 postoperative complications were recorded (10 Clavien grade IIIa or less). Median operative time was significantly longer in Group 1 (193 min) than in Group 2 (165 min, P = 0.003). Multivariate analysis identified male gender and cases done in Group 1 to be associated with increased operative time, while male gender and higher nephrometry scores were associated with increased blood loss. Tumor characteristics associated with greater reductions in GFR included higher nephrometry scores, endophytic tumors, and hilar tumors. In conclusion, RAPN appears to be safe and the major effect of the learning curve appears to be on operative time. Warm ischemia times are sufficiently low to prevent significant renal impairment, while male gender and higher nephrometry scores may be predictors of longer operative times and more intraoperative blood loss. Overall operative time decreased with increasing case volume, although this was not uniform among the three surgeons in the study. Further longitudinal study is necessary to establish oncologic outcomes.

Serum troponin levels are not increased in patients with ventricular arrhythmias during shock wave lithotripsy.

PURPOSE: Ventricular arrhythmias are common during ungated shock wave lithotripsy. We determined whether lithotripsy induced arrhythmias are associated with myocardial damage. MATERIALS AND METHODS: A total of 51 patients presenting for shock wave lithotripsy for right renal stones were prospectively evaluated for arrhythmias during lithotripsy. In patients with arrhythmias troponin levels were determined 24 hours after the procedure. RESULTS: Ventricular arrhythmias developed in 21 patients. In this group all troponin levels were below the level of detection (less than 0.5 ng/ml). CONCLUSIONS: Lithotripsy associated arrhythmias do not appear to be associated with myocardial injury.

CT in detecting urinary tract calculi: influence on patient imaging and clinical outcomes.

PURPOSE: To determine changes in examination patterns and effectiveness of care since the introduction of unenhanced helical computed tomography (CT) for examination of patients presenting to the emergency department (ED) with symptoms of urinary tract calculi (UTC). MATERIALS AND METHODS: Hospital clinical and radiology information systems were used to retrospectively identify patients presenting with UTC symptoms from January to December 1997 (before introduction of unenhanced CT) and from January to December 1999 (after introduction of unenhanced CT). Chart abstraction was used to confirm the identification of patients with presenting symptoms suggestive of UTC and assess patient outcomes. Two hundred sixty-five patients presented before (1997) and 602 after (1999) unenhanced CT was introduced. Distributions of dichotomous variables were compared between the 1997 and 1999 groups by using logistic regression. Means were compared between the groups by using analysis of variance and mean total numbers of imaging studies by using Poisson regression. RESULTS: Total number of imaging studies increased by 26.7% per patient visit (P <.001). Rates of admission following the initial ED visit (13.7% in 1997 vs 13.4% in 1999), as well as percentage of patients who subsequently returned to the ED (12.0% in 1997 vs 13.7% in 1999) or subsequently were admitted to the hospital (4.5% in 1997 vs 5.3% in 1999) in the month following the initial ED visit, were similar between the two groups. Unsuspected unenhanced CT findings that could affect acute patient care were observed at 5.9% of examinations. CONCLUSION: Use of imaging for suspected UTC has increased markedly since the introduction of unenhanced CT, with little effect on acute care of patients in the ED.