Shock Wave Lithotripsy Group Research Articles

Sixteen Years of Experience with Stone Management in Horseshoe Kidneys

Introduction: Horseshoe kidney is the commonest congenital renal fusion anomaly, and is often complicated by urolithiasis. We focus on our 16 years of experience with stone management in horseshoe kidneys. Materials and Methods: We reviewed the progress of 44 patients treated between 1987 and 2002. Shock wave lithotripsy (SWL) was used in 25 patients; the average stone surface area was 91 (range 10–1,600) mm² and average follow-up was 36.5 (range 1–91) months. 19 patients underwent percutaneous nephrolithotomy (PCNL); the average stone surface area was 197 (range 6–2,400) mm². Follow-up data are available for 8 patients and the average follow-up was 42.3 (range 3–144) months. Results: In the SWL group the 3-month stone-free rate (SFR) was only 31%. In the PCNL group the SFR was 75% on the postoperative day-1 KUB. Complications occurred in 9 patients. Conclusions: Stone management in horseshoe kidneys is challenging: PCNL produces a higher SFR with minimal major complications and failed access. PCNL thus appears to be the preferred management option in patients with urolithiasis in horseshoe kidneys.

Rapid Communication: Renal Apoptosis after Shockwave Application in Rabbit Model

To identify any apoptotic effect of shockwave lithotripsy (SWL) on renal tubular and glomerular cells. Thirty-five male New Zealand White rabbits were divided into five groups of seven rabbits each: I (control), II (sham), and III, IV, and GV (treated and sacrificed 1, 7, and 28 days after SWL, respectively). Intramuscular anesthetic agent (ketamine HCl; 20 mg/kg) and intravenous contrast medium (iohexol 300 mg of I/mL) were administered to animals in group II. The left kidneys of animals in groups III, IV, and V were exposed to 2000 shockwaves at 18 kV after administration of anesthesia and contrast medium. The animals were sacrificed on day 1, 7, or 28 after SWL, and the kidneys were removed. Apoptotic and proliferative indices of renal tubular and glomerular cells were determined by terminal deoxynucleotidyl transferase dUTP nick and label (TUNEL) and Ki-67 labeling methods, respectively, counting 1000 cells in each preparation. No apoptosis was detected in glomerular cells in any group. The mean apoptotic indices of the tubular cells in animals in groups I and II were 483.0 +/- 85 and 484.4 +/- 105, respectively with no significant difference between the groups. In groups III and IV, the mean apoptotic indices were 343.4 +/- 89 and 358.4 +/- 61, respectively. There were no statistically significant differences between groups III and IV and the control group. Similarly, there were no significant differences in the apoptotic indices in groups III and IV. However, the apoptotic index in group V was 821.4 +/- 57, significantly higher than in the control group. The proliferative indices of all SWL groups were lower than that of the control group. Shockwave lithotripsy has an apoptotic effect on renal tubular cells that can be detected 4 weeks after the procedures, but no apoptotic effect on glomerular cells. Treatment with SWL also attenuates the proliferation of both tubular and glomerular cells.

Prospective randomized trial comparing shock wave lithotripsy and ureteroscopic lithotripsy for management of large upper third ureteral stones

Objectives To conduct a prospective and randomized trial to compare the efficiency quotient and cost-effectiveness index of shock wave lithotripsy (SWL) and ureteroscopic lithotripsy (URSL) for the treatment of large upper third ureteral stones. Methods A total of 35 male patients and 7 female patients with a solitary, radiopaque upper ureteral stone, 15 mm or more in diameter, who underwent SWL or URSL were enrolled in this study. The mean patient age was 53.1 ± 14.5 years. The endpoint of the study was for the patient to be stone free or to have insignificant residual stone (3 mm or less) within the kidney. Results The mean stone length ± SD was 17.9 ± 3.9 cm in the SWL group and 18.5 ± 2.9 cm in the URSL group ( P >0.05). The efficiency quotient for SWL and URSL was 0.61 and 0.63, respectively. The cost-effectiveness index, treatment time, pain score, and hospital stay were greater in the URSL group. However, the degree of hydronephrosis significantly influenced the success rate of SWL. All patients with severe hydronephrosis in the SWL group needed auxiliary surgical procedures to become stone free. Conclusions The efficiency quotients of SWL and URSL were comparable in the treatment of large upper third ureteral stones. However, SWL should not be recommended as the first-line treatment option for the management of upper third ureteral stones larger than 1.5 cm with severe hydronephrosis. Understanding the cost-effectiveness, success rate, pain score, and patient satisfaction score for the two different approaches constitutes the indispensable requisites for choosing the optimal first-line therapeutic strategy.

Extracorporeal shock wave lithotripsy and transureteral lithotripsy in the treatment of impacted lower ureteral calculi.

We compared the efficacy of extracorporeal shock wave lithotripsy (SWL) with ureteroscopy followed by transureteral lithotripsy (TUL) for the treatment of impacted distal ureteral calculi. A total of 96 patients with solitary impacted distal ureteral calculi were assigned into 2 groups of treatment with SWL (42 patients) and TUL (54 patients) with a 6.9-F semirigid ureteroscope. Characteristics of the patients and the calculi, treatment parameters, clinical outcomes, and patients' satisfaction were assessed for each group as well as efficiency quotient. Demographic characteristics of the patients in the 2 groups were similar as well as the sizes of the calculi. The stone-free rate, 2 months postoperatively, was 71.4% in the patients of the SWL group and 88.9% in those of the TUL group. The efficiency quotient was 56% and 81% for the SWL and TUL groups, respectively (P = .004). Retreatment rate was 26.2% (11 patients) and 9.3% (5 patients) for the SWL and TUL groups, respectively (P = .027). Thirty patients in the SWL group (71.4%) and 52 in the TUL group (96.3%) were satisfied with their treatment (P = .001). There were no major complications in neither of the groups. Minor complications (pain and hematuria) were more common in the TUL group. Based on the results of this study, TUL seems to be more effective than SWL in the treatment of impacted lower ureteral calculi sized smaller than 12 mm, and patients are more satisfied with this treatment method.

Randomized controlled study of mechanical percussion, diuresis, and inversion therapy to assist passage of lower pole renal calculi after shock wave lithotripsy

Objectives To determine whether mechanical percussion, diuresis, and inversion (PDI) therapy after shock wave lithotripsy (SWL) improves the clearance rates of lower pole renal stones. Methods In this single-blind study, 108 patients who underwent SWL treatment for lower pole renal stones with a total diameter of 2 cm or less were prospectively randomized into two groups. One group (n = 49) received SWL only and the other group (n = 59) received a median of four sessions of PDI therapy (range 1 to 12), 1 to 2 weeks after each SWL session. PDI therapy was performed as follows. Patients drank 500 mL of water 30 minutes before therapy; they then lay in a prone Trendelenburg position on a 45°-angle couch, and received continuous 10-minute manual mechanical percussion applied over the flank. Stone clearance was documented with plain abdominal radiography, with additional imaging, if indicated, 1 and 3 months after initial SWL therapy. Results The patients from both groups were comparable in terms of total stone diameter, infundibular neck diameter, infundibular length, caliceal height, infundibular-pelvic angles, infundibular-ureteral angles, infundibular-vertebral angles, lower pole cortical thickness, and caliceal number. All patients underwent a maximum of four SWL treatments. For all assessable patients, the radiologically documented complete stone clearance rate at 3 months for the SWL-alone group was 35.4% and for the SWL plus PDI group was 62.5% (chi-square test, P = 0.006). Conclusions PDI therapy is a valuable adjunct in assisting passage of lower pole renal stone fragments after SWL therapy.

COMPARISON BETWEEN EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY AND SEMIRIGID URETERORENOSCOPE WITH HOLMIUM: YAG LASER LITHOTRIPSY FOR TREATING LARGE PROXIMAL URETERAL STONES

Management of large impacted upper ureteral calculi remains challenging for urologists. These calculi are frequently associated with obstructive uropathy and deteriorated renal function. Extracorporeal shock wave lithotripsy (SWL) is the least invasive treatment but its success rate is decreased for large impacted upper ureteral calculi. According to the American Urological Association guidelines on ureteral stones published in 1997, the appropriateness of ureteroscopy decreases when stone size exceeds 1 cm. However, the application of advanced ureteroscopy and techniques has increased the success rate of treating proximal ureter calculi. In this study we compared the safety and efficacy of ureterorenoscopic holmium:YAG laser lithotripsy (URSL) with SWL for large impacted proximal ureteral stones. This study evaluated 82 patients with large impacted upper ureteral stones. Two patients were excluded from study owing to conversion to open surgery. SWL and URSL were performed in 41 and 39 patients, respectively. Those in the SWL group were treated on an outpatient basis with Medispec Econolith 2000 (Medispec, Germantown, Maryland) under intravenous sedation. The URSL was performed with a 6/7.5Fr semirigid tapered ureterorenoscope and holmium:YAG laser with the patient under spinal anesthesia on an inpatient basis. Successful outcome was defined as the patient being stone-free on radiography 1 month after treatment. Stone size, success rate, postoperative complications and cost were analyzed in each group. A total of 80 patients were enrolled in this study. Hematuria and flank pain were the most common complaints in each group. Mean stone size +/- SD was 1.28 +/- 0.04 cm in the SWL group and 1.51 +/- 0.05 cm in URSL group (p = 0.0009). Accessibility of the semirigid ureterorenoscope for impacted upper ureteral stones was 95.1% (39 of 41) and the stone-free rate achieved after 1 sitting was 92% (36 of 39). The initial stone-free rate of in situ SWL was 61% (25 of 41). Notably, the initial stone-free rate in the URSL group was better than that of the SWL group (p = 0.003). The efficiency quotient was 0.53 for URSL and 0.59 for SWL. The average cost in the URSL group appears to be lower than in the SWL group. Both groups were free of major complications. This study demonstrated that URSL achieved excellent results for upper ureteral calculi greater than 1 cm. Thus, this procedure should be considered first line therapy for large proximal ureteral stones.

LOWER POLE I: A PROSPECTIVE RANDOMIZED TRIAL OF EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY AND PERCUTANEOUS NEPHROSTOLITHOTOMY FOR LOWER POLE NEPHROLITHIASIS—INITIAL RESULTS

The efficacy of shock wave lithotripsy and percutaneous stone removal for the treatment of symptomatic lower pole renal calculi was determined. A prospective randomized, multicenter clinical trial was performed comparing shock wave lithotripsy and percutaneous stone removal for symptomatic lower pole only renal calculi 30 mm. or less. Of 128 patients enrolled in the study 60 with a mean stone size of 14.43 mm. were randomized to percutaneous stone removal (58 treated, 2 awaiting treatment) and 68 with a mean stone size of 14.03 mm. were randomized to shock wave lithotripsy (64 treated, 4 awaiting treatment). Followup at 3 months was available for 88% of treated patients. The 3-month postoperative stone-free rates overall were 95% for percutaneous removal versus 37% lithotripsy (p <0.001). Shock wave lithotripsy results varied inversely with stone burden while percutaneous stone-free rates were independent of stone burden. Stone clearance from the lower pole following shock wave lithotripsy was particularly problematic for calculi greater than 10 mm. in diameter with only 7 of 33 (21%) patients becoming stone-free. Re-treatment was necessary in 10 (16%) lithotripsy and 5 (9%) percutaneous cases. There were 9 treatment failures in the lithotripsy group and none in the percutaneous group. Ancillary treatment was necessary in 13% of lithotripsy and 2% percutaneous cases. Morbidity was low overall and did not differ significantly between the groups (percutaneous stone removal 22%, shock wave lithotripsy 11%, p =0.087). In the shock wave lithotripsy group there was no difference in lower pole anatomical measurements between kidneys in which complete stone clearance did or did not occur. Stone clearance from the lower pole following shock wave lithotripsy is poor, especially for stones greater than 10 mm. in diameter. Calculi greater than 10 mm. in diameter are better managed initially with percutaneous removal due to its high degree of efficacy and acceptably low morbidity.

PROSPECTIVE RANDOMIZED TRIAL COMPARING SHOCK WAVE LITHOTRIPSY AND URETEROSCOPY FOR MANAGEMENT OF DISTAL URETERAL CALCULI

We compared the efficacy of shock wave lithotripsy and ureteroscopy for treatment of distal ureteral calculi. A total of 64 patients with solitary, radiopaque distal ureteral calculi 15 mm. or less in largest diameter were randomized to treatment with shock wave lithotripsy (32) using an HM3 lithotriptor (Dornier MedTech, Kennesaw, Georgia) or ureteroscopy (32). Patient and stone characteristics, treatment parameters, clinical outcomes, patient satisfaction and cost were assessed for each group. The 2 groups were comparable in regard to patient age, sex, body mass index, stone size, degree of hydronephrosis and time to treatment. Procedural and operating room times were statistically significantly shorter for the shock wave lithotripsy compared to the ureteroscopy group (34 and 72 versus 65 and 97 minutes, respectively). In addition, 94% of patients who underwent shock wave lithotripsy versus 75% who underwent ureteroscopy were discharged home the day of procedure. At a mean followup of 21 and 24 days for shock wave lithotripsy and ureteroscopy, respectively, 91% of patients in each group had undergone imaging with a plain abdominal radiograph, and all studies showed resolution of the target stone. Minor complications occurred in 9% and 25% of the shock wave lithotripsy and ureteroscopy groups, respectively (p value was not significant). No ureteral perforation or stricture occurred in the ureteroscopy group. Postoperative flank pain and dysuria were more severe in the ureteroscopy than shock wave lithotripsy group, although the differences were not statistically significant. Patient satisfaction was high, including 94% for shock wave lithotripsy and 87% for ureteroscopy (p value not significant). Cost favored ureteroscopy by $1,255 if outpatient treatment for both modalities was assumed. Ureteroscopy and shock wave lithotripsy were associated with high success and low complication rates. However, shock wave lithotripsy required significantly less operating time, was more often performed on an outpatient basis, and showed a trend towards less flank pain and dysuria, fewer complications and quicker convalescence. Patient satisfaction was uniformly high in both groups. Although ureteroscopy and shock wave lithotripsy are highly effective for treatment of distal ureteral stones, we believe that HM3 shock wave lithotripsy, albeit slightly more costly, is preferable to manipulation with ureteroscopy since it is equally efficacious, more efficient and less morbid.

Relationship between kidney size, renal injury, and renal impairment induced by shock wave lithotripsy.

The relationship between kidney size and impaired renal function induced by shock-wave lithotripsy (SWL) was examined in 6- and 10-wk-old anesthetized pigs. Each pig received 2000 shock waves, 24 kV, or sham SWL to the lower pole calyx of one kidney. Bilateral GFR, renal plasma flow (RPF), and para-aminohippurate extraction was measured 1 h before and 1 and 4 h after SWL. The kidneys were then removed for morphometric analysis. Mean kidney weights were 66.1+/-2.7 g (n = 9) and 103.1+/-3.3 g (n = 8) in the SWL groups, and 60.1+/-2.6 g (n = 9) and 82.3+/-4.0 g (n = 9) in the sham-SWL groups. SWL-induced lesions occupied a significantly greater volume of the small kidneys (6.1+/-1.7 vol % versus 1.5+/-0.2 vol% in the large kidneys). RPF was significantly reduced by SWL in small and large kidneys, but to a significantly greater extent in small kidneys. RPF was also significantly reduced in the contralateral kidneys of both groups, but only at 1 h after SWL. SWL significantly reduced GFR to similar degrees in both kidneys of both groups, regardless of kidney size. Para-aminohippurate extraction was likewise reduced to similar degrees in both groups, but this effect was evident only in the SWL-treated kidneys, and only in the pole to which the shock waves had been applied. The injury induced by SWL affected a larger fraction of small kidneys than large ones, and the renal vasoconstriction induced by SWL was greatest in small kidneys.

Small Caliceal Stones: What is the Best Method of Treatment?

In a retrospective analysis classical radial nephrolithotomy, percutaneous nephrolithotomy and extracorporeal shock wave lithotripsy for symptomatic small nonobstructive caliceal stones were compared to evaluate morbidity. Size (less than 1cm.) and location of the stone (caliceal and nonobstructive) did not explain the severity of the symptoms nor would they have been an indication for an operation.In 8 patients treated by an open operation, 16 treated percutaneously and 6 who underwent extracorporeal shock wave lithotripsy the procedure time, success rate, complication rate and length of hospitalization were analyzed. Followup consisted of ultrasound and/or a plain film of the kidneys, ureters and bladder 1 day and 3 months postoperatively. A nephrotomogram was included in group 3 patients. Of 30 patients 3 had persistent stone fragments for more than 3 months: 2 underwent percutaneous nephrolithotomy and 1 was treated by extracorporeal shock wave lithotripsy. A total of 28 patients (93.3 per cent) achieved complete or significant relief of pain. In the percutaneous group both patients with persistent fragments were symptomatic in contrast with the extracorporeal shock wave lithotripsy group, in which 1 patient presented with stone fragments but was free of pain. The group treated percutaneously had a shorter procedure time (60minutes) and the shock wave group had a shorter hospitalization. On the other hand, the open operation group had a better success rate as well as relief of pain.These observations showed that small, nonobstructive caliceal stones can be responsible for persistent, severe flank pain. Since extracorporeal shock wave lithotripsy is an effective noninvasive procedure that does not require routine anesthesia and hospitalization, with prompt return of the patient to normal life, it must be considered the method of choice in these particular patients. (J. Urol., 142: 941–942, 1989)