D. Duane Baldwin

Prospective Comparison of Four Laparoscopic Vessel Ligation Devices

PURPOSE The merits of laparoscopic sealing devices have been poorly characterized. The purpose of this study was to compare two bipolar sealing devices [LigaSure V (LS) and Gyrus PK (GP)], an ultrasonic device [Harmonic Scalpel ACE (HS)] and a novel device using nanotechnology [EnSeal PTC (ES)]. MATERIALS AND METHODS The ability of all four 5 mm devices to seal 5 mm bovine arteries was tested under controlled temperature and humidity in accordance with manufacturer specifications. Study endpoints included lateral thermal spread, time to seal, burst pressure, smoke production and subjective (blinded review of video clips) and objective (measured using an aerosol monitor) effect upon visibility. RESULTS The HS demonstrated the least thermal spread. The LS (10.0 secs) and GP (11.1 secs) had the fastest sealing times (p<0.001 for both) when compared to ES (19.2 sec) and HS (14.3 sec). Mean burst pressure values were: LS 385 mm Hg, GP 290 mm Hg, ES 255 mm Hg and HS 204 mm Hg. The HS had the best subjective visibility score and the lowest objective smoke production (2.88 ppm) compared to the GP (74.1 ppm), ES (21.6 ppm) and LS (12.5 ppm), (p<0.01 for all). CONCLUSIONS The LS has the highest burst pressure and fastest sealing time and was the highest rated overall. The HS produced the lowest thermal spread and smoke but had the lowest mean burst pressure. The GP had the highest smoke production, and variable burst pressures. Despite employing nanotechnology, the ES device was the slowest and had variable burst pressures.

Single-Center Comparison of Laparoscopic Pyeloplasty, Acucise Endopyelotomy, and Open Pyeloplasty

PURPOSE To compare Acucise endopyelotomy (Applied Medical, Irvine, California), laparoscopic pyeloplasty, and open pyeloplasty in the treatment of ureteropelvic junction (UPJ) obstruction. PATIENTS AND METHODS A retrospective review of all adult patients undergoing surgical correction of UPJ obstruction between December 1999 and August 2001 at Vanderbilt University Medical Center was performed. Patients undergoing UPJ correction with Acucise endopyelotomy (N = 9), laparoscopic pyeloplasty (N = 16), and open pyeloplasty (N = 7) were compared in regard to demographic information, operative data, recovery parameters, cost data, and outcome (as determined by diuretic renography, the Whitaker test, or both). RESULTS Success rates of 56%, 94%, and 86% were obtained for Acucise endopyelotomy, laparoscopic pyeloplasty, and open pyeloplasty, respectively. There were no differences between the Acucise endopyelotomy and laparoscopic pyeloplasty groups in age, American Society of Anesthesiology (ASA) score, length of follow-up, estimated blood loss (EBL), hospital stay, total hospital cost, or analgesic requirement. The Acucise patients demonstrated shorter operating times (1.7 v 3.3 hours; P < 0.001) and time to oral intake (7.9 v 16 hours; P = 0.008) than the laparoscopic pyeloplasty group. When the laparoscopic pyeloplasty patients were compared with the open pyeloplasty patients, there was no difference in operative time, EBL, time to oral intake, or total hospital costs. The laparoscopically treated patients demonstrated significantly lower analgesic requirements (27.2 v 124.2 mg of morphine sulfate equivalent; P = 0.02) and shorter hospital stays (1.4 v 3.0 days; P = 0.03) than the open surgery patients. The Acucise patients demonstrated shorter operative time (1.7 v 3.4 hours; P < 0.001), shorter hospital stay (1.3 v 3.0 days; P = 0.02), and lower analgesic requirement (22.4 v 124.2 mg of morphine sulfate equivalent; P = 0.02) than the open surgery patients. CONCLUSIONS Laparoscopic pyeloplasty achieves a success rate equal to that of open pyeloplasty while providing a recovery similar to that obtained with Acucise endopyelotomy and is gaining popularity as the treatment of choice for UPJ obstruction.

Effect of Low Dose Radiation Computerized Tomography Protocols on Distal Ureteral Calculus Detection

PURPOSE Unenhanced multidetector computerized tomography is the imaging modality of choice for urinary calculi but exposes patients to substantial radiation doses with a subsequent risk of radiation induced secondary malignancy. We compared ultra low dose and conventional computerized tomography protocols for detecting distal ureteral calculi in a cadaveric model. MATERIALS AND METHODS A total of 85 calcium oxalate stones 3 to 7 mm long were prospectively placed in 14 human cadaveric distal ureters in 56 random configurations. The intact kidneys, ureters and bladders were placed in a human cadaveric vehicle and computerized tomography was performed at 140, 100, 60, 30, 15 and 7.5 mA seconds while keeping other imaging parameters constant. Images were independently reviewed in random order by 2 blinded radiologists to determine the sensitivity and specificity of each mA second setting. RESULTS Overall sensitivity and specificity were 98% and 83%, respectively. Imaging using 140, 100, 60, 30, 15 and 7.5 mA second settings resulted in 98%, 97%, 97%, 96%, 98% and 97% sensitivity, and 83%, 83%, 83%, 86%, 80% and 84% specificity, respectively. Interobserver agreement was excellent (kappa >0.87). There was no significant difference in sensitivity or specificity at any mA second settings. All false-negative results were noted for 3 mm calculi at a similar frequency at each mA second setting. CONCLUSIONS Ultra low dose computerized tomography protocols detected distal ureteral calculi in a fashion similar to that of conventional computerized tomography protocols in a cadaveric model. These protocols may decrease the radiation dose up to 95%, reducing the risk of secondary malignancies.

Urothelial Carcinoma After External Beam Radiation Therapy for Prostate Cancer

PURPOSE We reviewed the clinical course of patients in whom urothelial carcinoma developed following radiation therapy for prostate cancer. MATERIALS AND METHODS A retrospective review of all patients between 1990 and 2005 with the diagnosis of bladder and prostate cancer was performed. Of 125 total patients new onset urothelial carcinoma developed in 11 after undergoing external beam radiation therapy for prostate cancer. RESULTS Whole pelvis external beam radiation therapy with a proton boost to the prostate was the radiation modality in 7 of the 11 patients (64%), while the remaining 4 patients received standard external beam radiation only. Urothelial carcinoma was detected a mean of 3.07 years after completion of radiation therapy in the proton group, compared to a mean latency period of 5.75 years in the standard radiation group (p = 0.09). Average patient age at diagnosis was 72 years (range 64 to 84). All patients presented with gross hematuria and had cystoscopic findings of coexisting radiation cystitis. Of the 11 patients 5 (45%) presented with grade 3 carcinoma and eventually 7 (64%) required radical cystectomy. Urothelial tumors with sarcomatoid features (carcinosarcoma and spindle cell sarcomatoid) developed in 2 patients (18%). Of the 11 patients 10 (91%) were nonsmokers at the time of urothelial carcinoma diagnosis. CONCLUSIONS Urothelial carcinoma in patients with previous radiation therapy for prostate cancer is often high grade, and the majority of patients have cancer progression requiring cystectomy. A high incidence of urothelial carcinoma with sarcomatoid features was seen in these patients.

Effect of Reduced Radiation CT Protocols on the Detection of Renal Calculi

PURPOSE To determine the effect of reduced radiation (tube charge, measured as milliamperes per second) protocols on the sensitivity and specificity of multidetector computed tomography (CT) in the detection of renal calculi. MATERIALS AND METHODS This Health Insurance Portability and Accountability Act-compliant human cadaveric study was approved by the Department of Anatomic Pathology with strict adherence to the university policy for handling donor specimens. Three to five renal stones (range, 2.0-4.0 mm) were randomly placed in 14 human cadaveric kidneys and scanned with a 16-detector CT scanner at 100, 60, and 30 mAs while maintaining other imaging parameters as constant. Following acquisition, images were reviewed independently by two radiologists who were blinded to the location and presence of renal calculi. Interobserver agreement was measured with kappa statistics. The McNemar test was used to compare the sensitivity and specificity between different radiation settings for each reader. RESULTS Specificity for both readers ranged from 105 (0.95; 95% confidence interval [CI]: 0.90, 0.99) to 109 (0.99; 95% CI: 0.95, 1.0) of 110 without significant differences between 30 and 60 mAs to the standard 100 mAs (P = .500 to >.999). Sensitivity ranged from 42 (0.74; 95% CI: 0.60, 0.84) to 48 (0.84; 95% CI: 0.72, 0.93) of 57, also without significant differences (P = .070 to >.999). When renal calculi detection rates were analyzed by size, 3.0-4.0-mm stones were detected well at all tube charge settings, ranging from 86%-90% (n = 21 for 3.0-mm stones) to 95%-100% (n = 19 for 4.0-mm stones). However, 2.0-mm stones were poorly detected at all tube charge settings (29%-59%; 5-10 of 17). Overall interobserver agreement for stone detection was excellent, with kappa = 0.862. CONCLUSION Decreasing the tube charge from 100 to 30 mAs resulted in similar detection of renal stones while reducing patient radiation exposure by as much as 70%. Multidetector CT scanning parameters should be tailored to minimize radiation exposure to the patients while helping detect clinically significant renal stones.

Single-Center Comparison of Purely Laparoscopic, Hand-Assisted Laparoscopic, and Open Radical Nephrectomy in Patients at High Anesthetic Risk

BACKGROUND AND PURPOSE The laparoscopic approach for management of high-risk patients with renal-cell carcinoma (RCC) may reduce perioperative and postoperative morbidity. The aim of this study was to compare the outcome of purely laparoscopic radical nephrectomy (LRN), hand-assisted laparoscopic radical nephrectomy (HALRN), and open radical nephrectomy (ORN) for renal tumors in a population of patients at high risk for perioperative complications. PATIENTS AND METHODS All patients undergoing radical nephrectomy for presumed RCC between August 1999 and August 2001 at Vanderbilt University Medical Center and having an American Society of Anesthesiologists (ASA) score of >/=3 were reviewed. Patients with known metastasis, local invasion, caval thrombi, or additional simultaneous surgical procedures were excluded from analysis. Thirteen patients underwent LRN, eight patients underwent HALRN, and 26 underwent ORN. The patient demographics were similar in the three groups. The groups were compared with regard to intraoperative and postoperative parameters. Statistical analysis was done using chi-square testing for categorical variables and analysis of variance (ANOVA) for continuous variables. Differences in outcomes were examined using ANOVA and Dunnetts T for pairwise comparisons. RESULTS The ASA 4 patients had significantly longer hospital stays and total hospital costs than the ASA 3 patients. The mean operative time in the ASA 3 patients was similar in the three groups: 2.8 hours, 2.8 hours, and 2.5 hours for the LRN, HALRN, and ORN patients, respectively. Both the LRN patients (22.9 mg of morphine sulfate equivalent) and the HALRN patients (42.1 mg) required less pain medication than the open surgery patients (97.7 mg). When the total hospital costs were compared, LRN was less costly than HALRN (

Fluoroscopic Organ and Tissue-Specific Radiation Exposure by Sex and Body Mass Index During Ureteroscopy

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Laparoscopic Donor Nephrectomy: Effect of Perirenal Fat upon Donor Operative Time

7678; P = 0.57) and open surgery (

Reduced Fluoroscopy Protocol for Percutaneous Nephrostolithotomy: Feasibility, Outcomes and Effects on Fluoroscopy Time

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KNOTTED URETERAL STENT: A MINIMALLY INVASIVE TECHNIQUE FOR REMOVAL

7694; P = 0.04). The complication rate in the LRN, HALRN, and ORN group was 0%, 25%, and 27%, respectively, although the differences were not statistically different (P = 0.12). CONCLUSIONS Both LRN and HALRN can be performed safely in patients with significant comorbid conditions. Careful preoperative preparation, intraoperative monitoring, and awareness of laparoscopy-induced oliguria can preclude inadvertent overhydration, hemodilution, and congestive heart failure. Both LRN and HALRN result in less pain medication requirement and faster return to oral intake than ORN, and LRN results in fewer perioperative complications than HALRN or ORN in patients at high perioperative risk. The LRN technique has a 21% lower total cost than both HALRN and ORN.