Reduction of radiation during fluoroscopic urodynamics: analysis of quality assurance protocol limiting fluoroscopic images during fluoroscopic urodynamic studies
OBJECTIVE:To evaluate whether the decrease in fluoroscopic images after initiation of a quality assurance (QA) protocol to decrease the amount of fluoroscopy during fluoro urodynamics (FUDS) translates into a significant reduction in radiation. METHODS:The number of spot films, fluoroscopy time, air kerma, and dose area product from FUDS performed by our division during the 3 months before the conceptualization of the QA protocol were compared with the parameters of FUDS performed by our division 3 months after the initiation of the protocol. To ensure the protocol did not adversely affect the analysis of FUDS, 10 FUDS studies were evaluated by 4 fellowship-trained female urologists who compared the interpretation when only the images per QA protocol were reviewed with that when the additional images were reviewed. RESULTS:A total of 54 FUDS studies performed in the 3 months before the conceptualization of the protocol were compared with 43 FUDS studies performed after initiation of the protocol. The mean number of spot films recorded before and after the QA protocol was 11.2 and 5.6, respectively (P<.001). The mean fluoroscopy time decreased from 40.9 to 11.7 seconds per procedure (P<.001). The mean air kerma decreased from 15.48 to 4.25 mGy, and the mean dose area product decreased from 518.90 to 150.28 mGyÂ·cm2 (P<.001 and P<.001, respectively). No difference was found in the treatment or diagnosis in 100% of the 40 FUDS evaluations. CONCLUSION/CONCLUSIONS:Our QA protocol significantly decreased the amount of fluoroscopy time, dose area product, and air kerma during each FUDS without changing the diagnosis or treatment recommendations.
Eighteen-year experience with the Medstone STS lithotripter: safety, efficacy, and evolving practice patterns
OBJECTIVE:To evaluate trends in safety, efficacy, and practice patterns for shockwave lithotripsy (SWL) procedures performed during a 18-year period and correlate the findings with recent evidence-based practice guidelines. MATERIALS AND METHODS/METHODS:From January 1988 to June 2006, 66,819 SWLs were performed using the Medstone STS lithotripter in patients with radiologic evidence of stones in the kidney or ureter. Treatment characteristics, such as stone location and size, need of re-treatment, and final success rate were recorded. The procedures were further divided by year for statistical consideration. Statistical analysis was performed using Student t test; P < 0.05 was considered significant. RESULTS:Overall SWL success rate was 85% (39,667/46,669), and the overall re-treatment rate was 7.2% (3,417/46,669). There was no significant change in the overall proportion of lower-pole calculi managed with SWL, although there was a significant decrease in the proportion of SWL used for lower calix stones larger than 16 mm in the time period after 2000 (P = 0.006). There was a steady increase in the number of procedures performed for renal calculi in other locations per year, in particular for intrarenal calculi smaller than 20 mm. Intrarenal stones larger than 30 mm decreased as a proportion of procedures per year (P = 0.048) There was no significant change in the proportion of upper and distal ureteral stones managed, corresponding to a solid plateau in the percentage of SWL performed per year. CONCLUSION/CONCLUSIONS:Our study did not demonstrate an overall drop in SWL; however, it did show the interference of endoscopic procedures on two case scenarios. There was a significant decrease (P = 0.048) in SWL for renal stones larger than 30 mm, and the same trend was noted for lower calix stones larger than 15 mm (P = 0.06).
Impact of type of anesthesia on efficacy of medstone STS lithotripter
PURPOSE/OBJECTIVE:To evaluate the impact of the type of anesthesia on treatment efficacy, using a comparison of general anesthesia (GEN) and monitored anesthesia care with intravenous sedation (MAC), for patients undergoing extracorporeal shockwave lithotripsy (SWL) on the Medstone STS lithotripter. PATIENTS AND METHODS/METHODS:A case-control study was conducted of 660 patients treated from 1986 to 2002. General anesthesia and MAC were utilized in 330 procedures each. Case matching was performed for stone size, stone location, and body mass index. All lithotripter units were staffed by a rotating schedule of the same 10 SWL-certified radiologic technicians. Patient characteristics, treatment parameters, complications, repeat procedures, and secondary procedures were recorded. Stone-free success rates (no residual fragments) were reported by the treating physician on the basis of plain radiographs. Chi-square analysis was used to compare patients in the two groups. RESULTS:The overall stone-free rate was better with GEN (67%) than MAC (55%; P = 0.04). Stone-free rates were not affected for stones <or=10 mm (GEN 69%, MAC 63%; P = 0.42). The type of anesthetic impacted stone-free rates in the upper calix (GEN 75%, MAC27%; P = 0.05). CONCLUSIONS:This study helps define that population that may benefit most from the use of GEN: those with stones >10 mm or in an upper calix. General anesthesia may decrease excursion of the calculus out of the focal area secondary to breathing or patient movement.
Locally ablative therapies for primary radiation failures: a review and critical assessment of the efficacy
A significant number of men with prostate cancer will experience biochemical failure following treatment with primary radiation therapy. For patients with biopsy-proven recurrent cancer confined to the prostate, local salvage therapy may be a potentially curative treatment option. Most men, however, do not undergo local salvage therapy owing to difficulties in diagnosis as well as concerns over treatment-related complications in the salvage setting. Recently, improvements in technique and technology have substantially reduced the morbidity associated with locally ablative therapies, resulting in an increased interest in the use of minimally invasive therapies such as brachytherapy, cryotherapy, and high-intensity focused ultrasound in the salvage setting. Although these treatments are well tolerated, concerns remain over incomplete and inadequate treatment with locally ablative therapies. Future studies are required to appropriately select candidates for salvage ablative therapies and to determine the long-term oncologic efficacy of these treatments
Impact of renal function on efficacy of extracorporeal shockwave lithotripsy
BACKGROUND AND PURPOSE/OBJECTIVE:Adequate urine production and excretion may be important for clearance of stone fragments after extracorporeal shockwave lithotripsy (SWL). This study evaluated the impact of renal function, measured by preoperative serum creatinine concentration, on the efficacy of SWL. PATIENTS AND METHODS/METHODS:From 1986 to 2001, 27,299 patients with urolithiasis were treated with Medstone STS lithotripters. Seven hundred ninety-eight of these patients (2.92%) had serum creatinine concentrations >or=2.0 mg/dL. Perioperative renal function (serum creatinine), treatment parameters, stone-free success rate (no residual fragments on plain film), and perioperative complications and procedures were recorded. RESULTS:The stone-free rate for patients with serum creatinine values from 2.0 to 2.9 mg/dL (56.69%) was significantly less than that seen in patients with a creatinine concentration <2.0 mg/dL (66.20%). The retreatment rate and secondary-procedure rate were significantly higher in patients with higher serum creatinine values (9.62% and 8.92%, respectively) than in those with serum creatinine within the normal range (6.07% and 4.27%, respectively). There was no significant difference in the stone-free rate, re-treatment rate, and secondary-procedure rate of patients with serum creatinine >or=3.0 mg/dL in comparison with patients with values <2 mg/dL. Complication rates were higher for patients with serum creatinine values >4.0 mg/dL (10.91%) than for patients with creatinine <2.0 mg/dL (2.62%). CONCLUSIONS:The efficacy of SWL is decreased in patients with serum creatinine concentrations of 2.0 to 2.9 mg/dL, and the complication rate is higher in patients with serum creatinine >4.0 mg/dL. Preoperative counseling may include a discussion of the impact of renal insufficiency on success and complication rates associated with SWL.
The Medstone fixed, mobile, and modular configurations: impact on efficacy
PURPOSE/OBJECTIVE:To evaluate the efficacy of three lithotripter configurations that utilize the Medstone STS treatment head. PATIENTS AND METHODS/METHODS:From 1999 through 2002, 13,131 patients were treated with the Medstone STS fixedsite unit (STS-FIX; 52%), the mobile coach-transportable unit (STS-MOB; 26%), or the modular operating-room unit (STS-T; 22%). All units were staffed by a rotating schedule of the same ten SWL-certified radiological technicians. The treating urologists reported follow-up that included plain abdominal radiography to document stone-free rate (no residual fragments) and the need for auxiliary procedures or re-treatment. An efficiency quotient (EQ) was calculated for each unit. RESULTS:The overall stone-free rate for the STS-FIX, STS-MOB, and the STS-T was 59%, 62%, and 65%, respectively. The STS-FIX had the lowest stone-free rate for lower-pole stones (48%) and stones 21 mm to 30 mm (30%) compared with the STS-MOB (57% and 62%, respectively) and the STS-T (59% and 54%, respectively). However, the STS-FIX had a higher stone-free rate in the middle ureter (86%) than the STS-T (67%) and STS-MOB (65%). The STS-FIX required more post-SWL procedures overall (12%) than the STSMOB (4%) and STS-T (5%). The re-treatment rates for the STS-FIX, STS-MOB, and STS-T were 7%, 6%, and 6%, respectively. The STS-T had the highest overall EQ (59) followed by the STS-MOB (56) and the STSFIX (50). CONCLUSIONS:New configurations of the STS lithotripter have a significant positive impact on efficacy compared with the original fixed machine. Availability of real-time fluoroscopy with the STS-T may impact the higher EQ of this machine.
Randomized prospective evaluation of nephrostomy tube configuration: impact on postoperative pain
OBJECTIVE:Conduct a prospective randomized single-blind comparison of two nephrostomy catheter designs, evaluating specifically intraoperative placement and postoperative comfort. MATERIALS AND METHODS/METHODS:The single-blind, prospective randomized trial was conducted with institutional review board approval. All patients undergoing percutaneous nephrolithotomy who gave informed consent were randomized to placement of either a Boston Scientific Flexima 8.3F pigtail nephrostomy tube #27-180 (PIG) or a Boston Scientific 8.2F nephroureteral stent #410-126 (NUS). Randomization was concealed from the surgeon until time of placement. Subjective intraoperative placement characteristics were rated by the surgeon on a scale of 1 = excellent, 2 = fair, 3 = good and 4 = poor. The patient's postoperative pain intensity was evaluated with a Visual Analog Pain Score (0 = no pain to 10 = worst pain). RESULTS:Nine patients were randomized to each group. The PIG group was rated significantly better than the NUS group with regards to ease of placement (p = 0.007) and radiopacity of the tube (p = 0.007) by surgeon. Visual analog pain scores on postoperative day one, was significantly lower in the PIG group (mean = 2+/-2) than the NUS group (mean = 5+/-1) (p =0.004). The mean amount of intra-venous morphine equivalent given in the PIG group (mean = 1+/4 Eq morphine) was less on average compared to the NUS group (mean = 6+/13 Eq morphine), but the differences did not reach statistical significance (p = 0.06). CONCLUSIONS:Following percutaneous nephrolithotomy, use of a small pig-tail nephrostomy tube results in greater ease of placement and less postoperative pain than a nephroureteral catheter.
Impact of shockwave coupling on efficacy of extracorporeal shockwave lithotripsy
PURPOSE/OBJECTIVE:To evaluate the impact of a slow gated treatment rate on the efficacy of extracorporeal shockwave lithotripsy (SWL). PATIENTS AND METHODS/METHODS:From August 1990 to July 2002, 40,462 SWL procedures were performed using the slow frequency electrocardiography (ECG)-gated lithotripter (82.5%) and fast frequency ECG-ungated (17.5%) modes for the Medstone STS lithotripter. Treatment characteristics, including the mode of SWL, location and size of the stone, re-treatment status, auxiliary procedures required, perioperative complications, and treatment outcomes, were recorded. The stone-free rate was reported by the treating physician on the basis of the finding of no residual stone fragments on a plain radiographic image. RESULTS:The treatment rate for the slow mode was a mean of 79.6 shocks/min, while the rate for the fast mode was 120/min. The total procedure time was 47.0 minutes for the slow mode and 40.6 minutes for the fast. The overall stone-free rate was higher for slow (66.9%) than fast (63.6%) procedures (P < 0.001). The stone-free rate for 1- to 10-mm stones was higher for the slow procedures (75.7%) than the fast procedures (70.7%; P < 0.001). Upper-ureteral stones responded better to slow treatment in terms of stone-free rate (79.5% v 72.6%; P < 0.001), re-treatment rate (6.5% v 8.0%, P = 0.05), auxiliary-procedure rate (6.1% v 8.9%; P = 0.01), and efficiency quotient (71 and 62). There was no significant difference in complication rates overall between slow and fast treatment. CONCLUSIONS:With a minimal increase in procedure time, greater efficacy can be obtained for the treatment of radiopaque stones with a slower shock-delivery rate. In particular, upper-ureteral calculi and calculi <10 mm benefit from a slower treatment rate.
Durability of flexible ureteroscopes: a randomized, prospective study
PURPOSE/OBJECTIVE:We performed a randomized, prospective, multi-institutional study evaluating the durability of commercially available flexible ureteroscopes. MATERIALS AND METHODS/METHODS:A total of 192 patients were randomized to the use of 7 less than 9Fr flexible ureteroscopes, including the Storz 11274AA and Flex-X, the ACMI DUR-8 and DUR-8 Elite, Wolf models 7330.170 and 7325.172, and the Olympus URF-P3. Information about total and lower pole use time, the number and method of ureteroscope insertion, and they type and duration of accessory instrumentation was recorded. Surgeons were asked to rate the visibility and maneuverability of the instrument on a scale of 0-poor to 10-excellent. RESULTS:The indication for ureteroscopy was upper tract calculi in 87% of cases. Of ureteroscope insertions 97% were performed through an access sheath. The average of number of cases before repair ranged from 3.25 for the Wolf 7325 to 14.4 for the ACMI DUR-8 Elite. Average ureteroscope operative time was statistically longer for the DUR-8 Elite (494 minutes) than for the Flex-X (p = 0.047), and the Wolf 7325 and 7330 (p = 0.001 and 0.001, respectively). Duration of use before repair for the URF-P3 (373 minutes) was statistically longer than for the Wolf 7325 and 7330 (p = 0.016 and 0.017, respectively). Minutes of use with an instrument in the working channel were significantly more with the DUR-8 Elite and the URF-P3 than the Wolf 7330 (p = 0.017 and 0.008) and 7325 (p = 0.012 and 0.005, respectively). The ureteroscope that experienced the greatest average duration of lower pole use was the URF-P3, while the shortest was the Wolf 7325 (103 vs 20 minutes, p = 0.005). Average minutes of laser use before breakage was significantly longer for the DUR-8 Elite than for the Wolf 7325 (110 vs 21 minutes, p = 0.021) and 7330 (24 minutes, p = 0.025). CONCLUSIONS:Currently available less than 9Fr flexible ureteroscopes remain fragile instruments. The DUR-8 Elite and Olympus URF-P3 proved to be the most durable devices.
Randomized evaluation of Ureteral Stents using validated Symptom Questionnaire
BACKGROUND AND PURPOSE/OBJECTIVE:Ureteral stents are associated with significant pain and urinary symptoms. Manufacturers have altered stent designs and materials in an attempt to minimize this morbidity. This study evaluated the impact of these modifications. PATIENTS AND METHODS/METHODS:Stent manufacturers were asked to provide the 6F ureteral stent they believed would be associated with the least patient discomfort. Patients undergoing uncomplicated ureteroscopy were randomized to the Bard Inlay, Cook Endo-Sof, Microvasive Contour, Applied Medical Vertex, or Surgitek Classic Double-Pigtail stent. The Ureteric Stent Symptom Questionnaire (USSQ) was administered on days 1, 3, and 5, and the patients maintained a narcotic diary. The data were analyzed using ANOVA and nonparametric methods. RESULTS:A total of 44 patients (73%) completed all USSQ questionnaires. Urinary symptom scores were significantly lower for the Inlay stent on day 3 than for the Vertex (P = 0.01), Contour (P = 0.05), Endo-Sof (P = 0.03), and Classic (P = 0.02) stents. No significant differences were noted in pain and general symptom scores or narcotic use. CONCLUSIONS:The Bard Inlay stent is associated with less-severe urinary symptoms than other ureteral stents. The USSQ is a sensitive tool to measure differences between stents.