Impact of shockwave lithotripsy on upper urinary tract calculi

Mini-percutaneous nephrolithotomy

Standard percutaneous nephrolithotomy is highly effective for the removal of renal calculi. However, significant morbidity has been associated with this procedure. Consequently, many urologists inappropriately defer to a less effective procedure to reduce patient morbidity. This practice may increase the total number of procedures needed for treatment and result in a substantial increase in health care costs. Mini-percutaneous nephrolithotomy using a 13F ureteroscopy sheath is described to reduce the morbidity associated with standard percutaneous nephrolithotomy while maintaining its efficiency and effectiveness for stone removal. The indications and technique for mini-percutaneous nephrolithotomy and our results are summarized.

Ureteroscopic lithotripsy using mini-endoscope and Swiss lithoclast: experience in 147 cases

To evaluate the efficacy of a semirigid mini-endoscope and the Swiss Lithoclast compared with a conventional rigid endoscope and ultrasound, the results of transurethral ureteroscopic lithotripsy in 147 patients over a period of 30 months were analyzed according to the type of ureteroscope (rigid v semirigid) and energy (ultrasound v Lithoclast) used. In the initial 25 cases (Group I), a conventional rigid ureteroscope and ultrasound were used. The latter 122 patients (Group II) were subjected to ureteroscopic lithotripsy using a miniscope and the Lithoclast. The results were superior in Group II with respect to the overall success rate (p = 1.6 x 10[-2]), first-attempt success rate (p = 2.9 x 10[-4]), and the need for ureteral dilation (P = 1.0 x 10[-6]) compared with Group I. There were no major complications. Overall, minor complications (hematuria and urinary tract infection) were observed in 25% of the cases. Further, the results of ureteroscopic lithotripsy in Group II were comparable to those of SWL in situ for upper ureteral calculi and better than for those located in the iliac and lower ureter as reported previously. Our results demonstrate that the Swiss Lithoclast provides effective fragmentation of even hard and smooth stones without increasing the complication rate. This lithotripter is reliable, safe, and simple to operate. In addition, the cost of maintenance is almost nil.

Early detection of infected ureteral obstruction after SWL employing C-reactive protein

Infection of the obstructed upper urinary tract is a severe complication of stone disease. Early detection and therapy is crucial to prevent septicemia. The authors investigated prospectively whether C-reactive protein (CRP) might act as a marker for the early detection of infected upper urinary tract obstruction. The serum concentration of CRP was compared with the classic markers of inflammation--white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and temperature--in the follow-up of 85 patients undergoing 173 extracorporeal shockwave lithotripsy (SWL) treatments. Post-SWL, 69% of the patients showed dilation of the upper tract on ultrasonography and 16.5% became symptomatic and required intervention. In this group, the mean CRP value was increased 18-fold, whereas the WBC count, ESR, and temperature were not markedly raised. In contrast, patients with no need for additional treatment showed no more than a 2-fold increase in CRP. C-Reactive protein seems to be a useful indicator for the early detection of infected upper urinary tract obstruction.

Effect of alkaline citrate therapy on clearance of residual renal stone fragments after extracorporeal shock wave lithotripsy in sterile calcium and infection nephrolithiasis patients

The natural history of post-extracorporeal shock wave lithotripsy residual stone fragments (clearance, growth and aggregation) is incompletely known, even though they are believed to constitute a risk in terms of new stone formation and persistent infection of the urinary tract. We addressed this issue and the hypothesis that alkaline citrate therapy improves residual stone fragment clearance in a 12-month followup study. There were 40 sterile calcium and 30 struvite stone patients with residual fragments after extracorporeal shock wave lithotripsy (diameter less than 5 mm.) consecutively enrolled and randomly assigned to a citrate therapy (6 to 8 gm. per day) or control (hygienic measures only) group. Infection stone patients also received adequate antibiotic therapy throughout the study. Among the patients in the untreated sterile group 21% and 32% were stone-free at 6 and 12 months, respectively. In the infection group these figures were 27% and 40%, respectively. Among the untreated sterile calcium stone patients in whom clearance was not achieved a high percentage experienced residual fragment growth or reaggregation. Citrate therapy significantly improved the stone clearance rate in the sterile (at 6 and 12 months 65% and 74% were stone-free, respectively) and infection (71% and 86%, respectively) stone patients, and prevented residual fragment growth or reaggregation in subjects in whom clearance was not achieved. The data show that growth and persistence are common in the natural history of residual stone fragments. Citrate ameliorated the outcome of these residual fragments by reducing the growth or agglomeration, and by increasing the clearance rate in calcium oxalate and in infection stone patients.

The fate of residual fragments after extracorporeal shock wave lithotripsy monotherapy of infection stones

We reviewed 53 patients with infection stones treated by extracorporeal shock wave lithotripsy (ESWL*) monotherapy to determine the long-term rate free of stones and the stone recurrence rate as correlated with the pre-treatment stone burden and the radiological presence of sand or fragments after the procedure. Long-term followup (mean 26.6 months) was available on 33 patients representing 38 kidneys. Although only 3 kidneys were free of stones immediately after ESWL, 20 were without stones at 3 months and 18 (47%) were stone-free at followup. Of 9 kidneys with fragments of more than 5 mm. after the final treatment 7 (78%) had residual fragments at 3 months and experienced stone progression. Of 9 kidneys with sand remaining 6 (66%) and all 3 kidneys that appeared to be free of stones after ESWL were without stones at followup. The 3-month plain film of the kidneys, ureters and bladder was a reliable indicator of eventual outcome. Of 20 kidneys that were free of stones at 3 months 16 remained without stones. Of 18 kidneys with residual stone particles at 3 months 14 showed disease progression, 2 had stable disease and 2 passed residual sand. Only 1 of 17 patients who were free of stones or had stable stone disease had a positive urine culture at followup. Patients with infection stone fragments 3 months after ESWL monotherapy have a high rate of stone progression (78%) and should undergo further treatment. ESWL monotherapy of infection stones requires close patient followup to assure that all residual fragments have passed and urine remains sterile.

Extracorporeal shock-wave lithotripsy for stones in solitary kidney

Twelve extracorporeal shock-wave lithotripsy (ESWL) treatments were performed on 10 patients with a solitary kidney. Nine patients had a ureteral stent placed pretreatment. Nine patients were available for follow-up. Seven (78%) were stone free or had insignificant fragments at three months. Complications were seen in 4 patients, including two instances of pyelonephritis. Failures were associated with an increased stone burden. ESWL is an effective and safe treatment for upper urinary tract stones in patients with a solitary kidney. We recommend pretreatment stenting in patients with a solitary kidney.

Side-effects of extracorporeal piezoelectric shock wave lithotripsy (EPL)

In the Department of Urology, University of Freiburg, West Germany extracorporeal piezoelectric shock wave lithotripsy (EPL) has been used in the treatment of urinary and biliary stones since November 1987. The first 85 treatments (in 71 patients) for renal stones were evaluated with regard to complications and side effects. There was no need for any anesthesia. Urinary obstruction was observed in 12% of the cases. Aside from the urinary obstruction and urosepsis (2%) no serious complications were seen. Endourological auxiliary measures were applied in 32% (27% prophylactically). The temporary glomerular damage which appeared in some patients vanished within 6 days after treatment. Because of possible asymptomatic ureteral obstruction a close follow up by ultrasound is recommended. EPL was found to be a useful method of treatment for renal calculi with few side effects.

Extracorporeal shock wave lithotripsy and cardiac arrhythmias

Holter monitoring was performed in 400 patients undergoing extracorporeal shock wave lithotripsy (ESWL). The highest heart rate occurred before and after ESWL. During respiratory-triggered ESWL, 30% of the patients had one or more ventricular premature beats (VES), and 7% had couplets of VES. The number of ventricular and supraventricular premature contractions was significantly lower during ECG-triggered ESWL. Ventricular tachycardia occurred in seven patients during respiratory-triggered ESWL, and in one patient during nontriggered ESWL. All ventricular tachycardias were nonsustained, asymptomatic, and slow. Supraventricular tachycardia was seen in nine patients. The preference of the urologist for respiratory-triggered ESWL, conflicts with its higher incidence of ventricular arrhythmias.

Management of simultaneous renal and ureteral calculi: combined extracorporeal shock wave lithotripsy and ureteroscopy under a single anesthetic

Simultaneously occurring renal and ureteral calculi were treated in 28 renal units combining extracorporeal shock wave lithotripsy and ureteroscopy during a single anesthetic session. Distributions of ureteral calculi removed or attempted to be removed by ureteroscopy were upper third in 3, middle third in 4 and lower third in 21. If ureteroscopy was successful a ureteral stent was placed and extracorporeal shock wave lithotripsy was applied to more proximal renal and upper ureteral calculi. Of 28 renal units 25 (89%) were rendered free of stones or had passable calculi of less than 3 mm. in diameter after a single combined treatment. This combined approach appears to be safe, effective and efficient.

Evaluation of extracorporeal shock wave lithotripsy without anesthesia using a Dornier HM3 lithotriptor without technical modifications

In 210 patients with urolithiasis extracorporeal shock wave lithotripsy was performed without regional, general or infiltration anesthesia by means of a technically unmodified Dornier HM3 lithotriptor. The stone burden varied from small ureteral stones to complete staghorn stones. All patients were given premedication with pethidine and diazepam, and a lidocaine-prilocaine-containing cream was applied on the skin at the entry site of the shock wave. Energy usually varied between 14 and 16 kv. More than 90% of the patients reported the pain to be at most of moderate intensity and acceptable. Less than 3% found the treatment unpleasant. The results were compared to those obtained in 250 patients treated with anesthesia according to the original procedure, with a generator voltage of 18 to 23 kv. The number of extracorporeal shock wave lithotripsy sessions for ureteral and large stones was somewhat higher with the low energy method than with the original procedure. However, the therapeutic result in terms of renal units without stones after 4 weeks was similar to that recorded for patients treated with the anesthesia method. According to these promising results we believe that extracorporeal shock wave lithotripsy without anesthesia in an unmodified Dornier HM3 lithotriptor can be performed successfully in a majority of patients and is an attractive alternative to other technical modifications of the equipment.

Extracorporeal shock-wave lithotripsy of renal calculi

Extracorporeal shock-wave lithotripsy (ESWL) is a noninvasive technique that utilizes focused shock waves to fragment stones into sand-sized particles, which then pass spontaneously with urination. The clinical use of this technique was introduced in 1980 in Germany by Chaussy and associates and has replaced most open surgery and percutaneous endoscopy for stone removal. The physics of shock waves, equipment, techniques, and patient selection in ESWL are discussed. Results of treatment of renal, upper ureteral, and lower ureteral calculi are reviewed and compared. Complications of treatment, including ureteral obstruction, hemorrhage, and tissue damage, are discussed. The advent of second-generation lithotripters has widened the parameters for patient selection in the treatment of ESWL and has increased the availability of this treatment modality.

Extracorporeal shock wave lithotripsy. Use of antibiotics to avoid postprocedural infection

Extracorporeal shock wave lithotripsy (ESWL) has the potential to revolutionize the treatment of urolithiasis, but its success depends in part upon minimizing potential sequelae. Although ESWL is safe, effective, and relatively economical, one complication can be urosepsis, resulting from liberation of bacteria when the stones disintegrate. Patients who are at increased risk of infection are those who have existing urinary tract infection; perioperative urologic manipulation; infected stones; predisposition for infectious endocarditis; or multiple, large, or complex stones. If urosepsis occurs, it usually requires prolonged hospitalization, which obviates any cost-benefits that can be accrued from ESWL. Prophylactic use of an antibiotic before ESWL is rational and cost-effective. Ideally, the antibiotic should possess a spectrum of activity against the most likely bacteria to be encountered, require a limited number of doses, and offer the flexibility of sustained coverage in the event that the procedure is delayed. Our experience at Presbyterian Hospital of Dallas supports the use of a long-acting cephalosporin for the prevention of infections following ESWL.

A review of the ultrasonic bioeffects of microsonation, gas-body activation, and related cavitation-like phenomena

Ultrasonic exposures localized to regions smaller than a wavelength minimize the thermal mechanism, but promote nonthermal mechanisms of ultrasonic bioeffects. Microsonation experiments with vibrating needles or wires exploit this situation for the study of nonthermal mechanisms such as acoustic microstreaming flow. Shear stress in microstreaming flow, which is in excess of critical values for biomembranes, leads to cell lysis. Plane wave exposure of small bodies of gas also yields localized exposure, with further amplification of nonthermal mechanisms by resonance activation of oscillation. Gas body activation in vitro causes gathering of suspended cells by radiation forces, aggregation, cellular effects and lysis by microstreaming. When suitable gas bodies are present, these effects may occur at levels below the threshold for ultrasonic cavitation. In vivo, gas body activation generates intracellular microstreaming in Elodea leaves and disrupts the cells for super-critical shear stress levels. Similar phenomena seem to account for cell death, growth and mitotic index reductions in other plant tissues, and developmental abnormalities and delayed death in fruit flies. Only fragmentary and equivocal evidence presently exists on the medically relevant question of whether such subthreshold cavitation-like activity and bioeffects occur in vertebrates.

Same-session endourological removal of upper and impacted lower urinary tract stones with the aid of prone flexible cystoscopy

Calculi were removed from the upper urinary tracts and the distal ureter in single sessions in 2 patients with the aid of prone flexible cystoscopy and a through-and-through stone basket.