Extracorporeal shock wave lithotripsy for urinary tract stones using MPL 9000 spark gap technology and ultrasound monitoring

[Ultrasonography in urology]

After its introduction more than twenty years ago, ultrasound has continually increased in importance in urology diagnostics and is currently one of the most frequent exploratory techniques used. It corresponds to one out of every four imaging techniques carried out in medicine. The possibility of intervention under echographic control, for either diagnostic or therapeutic purposes, has been studied ever since ultrasound first appeared. Nowadays, interventionist echography is a commonly used technique in urology and is applied in a wide range of procedures carried out on the prostate gland, bladder and kidney that require echography-guided puncture techniques. Timely modifications of ultrasound for control and monitoring of treatments such as shock wave extracorporeal lithotripsy or transperineal brachitherapy has increased even more its day-to-day use by urologists. New technologies currently under development such as high-energy ultrasound in the management of kidney and prostate cancer, 3-dimensional ultrasound, Doppler-energy and contrast ultrasound have also increased the importance of this procedure in urology.

Is measurement of stone surface area necessary for SWL treatment of nonstaghorn calculi?

BACKGROUND AND PURPOSE

The size of urinary tract stones is usually assessed by the longest diameter (LD) alone. Logically, however, two-dimensional measurement of the stone surface area (SSA) susceptible to shockwaves would give more useful information for the planning of treatment by extracorporeal shockwave lithotripsy (SWL). This has been shown for staghorn calculi. The aim of this study was to determine for nonstaghorn kidney and ureter stones whether the LD alone identifies as reliably a subgroup of patients with a stone of a certain size as does the SSA. Furthermore, we sought to determine whether the LD alone indicates as reliably the number of patients who would be rendered stone free after one SWL session within a certain subgroup as would the SSA.

PATIENTS AND METHODS

Retrospectively, SWL treatment and radiographic data of 330 patients who had undergone SWL for a single stone were analyzed.

RESULTS

Ureteral stones were significantly smaller on average, and ureteral stone patients needed fewer SWL treatment sessions and fewer shockwaves to become stone free. Stratification of both kidney and ureteral stones by either LD or SSA resulted in comparable groups of patients. There were no significant differences in patient, stone, or treatment data. More importantly, the stone-free rates after one treatment did not differ significantly.

CONCLUSION

The LD does accurately reflect the size of a nonstaghorn kidney or ureteral stones. Therefore, the measurement of LD, as generally practiced, appears clinically sufficient and appropriate for the assessment of stone size prior to SWL in both kidney and ureteral stones.

Reduction of radiation exposure to patients in the follow-up of shockwave lithotripsy

OBJECTIVES

To assess, in patients undergoing extracorporeal shock wave lithotripsy (ESWL), if a policy of using unilateral X-rays of the kidney, ureter and bladder (hemi-KUB) whenever possible and appropriate during diagnosis and follow-up, was successful in reducing the radiation exposure associated with ESWL.

PATIENTS AND METHODS

Two groups of patients of statistically comparable size and demography were assessed retrospectively before and after the implementation of the policy. All had undergone ESWL for radio-opaque upper urinary tract stones and all were finally rendered stone-free. The number and type of all radiological procedures from initial diagnosis of the stone to documented stone-free status were recorded and the dose calculated.

RESULTS

The appropriate use of hemi-KUB X-rays resulted in a significant mean reduction of radiation exposure after treatment of 2.28 mSv per patient (P<0.05). Furthermore, as expected, the radiation dose was clearly but not closely correlated with stone size (r = 0.419).

CONCLUSIONS

The appropriate use of hemi-KUB X-rays during the follow-up after ESWL is a simple and effective way of significantly reducing the radiation exposure of such patients.

Pediatric urolithiasis

Urolithiasis in childhood is of diverse etiology requiring carefully planned individualized diagnostic and management protocols. The efficiency in diagnosis and management of urolithiasis in childhood follows a learning curve, especially when using the more recent technical innovations for management of urinary calculi. With current technical sophistication of transurethral and percutaneous techniques and ESWL, management of urolithiasis during childhood should be relatively straightforward as monotherapy using a single modality or as a combined approach with one or more techniques, saving open surgical intervention for situations where the new technology is either unavailable or inappropriate, or when surgical reconstruction of the urinary tract is necessary to forestall recurrent calculus formation. Postoperative morbidity after management of urinary calculi during childhood appears insignificant; calculus recurrence is uncommon. Long-term postoperative follow-up is mandatory, especially after using the newer technical innovations for urinary calculus management during childhood.

Extracorporeal shock wave lithotripsy (ESWL) for urinary tract stones using Dornier MFL 5000, performed by the technician

As the only lithotripsy centre at a University Hospital in the most crowded city of Turkey, we have a big number of patients with urinary stones. Between April 1990 and August 1993, 2680 sessions of treatment were done to 1257 renal units. Our study reveals that the results obtained by the performance of an experienced technician are just as reliable as those obtained by an experienced urologist.

The scope and place of ultrasound-monitored extracorporeal shock wave lithotripsy in a multimodality setting and the effects of experiential, audit-evoked changes on the management of ureteric calculi

OBJECTIVE

To assess the results from ultrasound-monitored extracorporeal shock wave lithotripsy (ESWL) for ureteric stones, to compare the results with other treatment modalities and to evaluate experiential audit-evoked gains.

PATIENTS AND METHODS

A review of the records of 109 patients with ureteric stones who were treated during 1990 (Group I) and 69 patients treated by ESWL during the first 10 months of 1991 (Group II), was carried out. All patients with a steinstrasse or fragments secondary to ESWL were excluded from the study.

RESULTS

Of the 109 patients in Group I, 63 were treated with ESWL, nine underwent ureteroscopic push-up of the stone and 11 underwent catheter push-up prior to ESWL, 28 underwent ureteroscopic extraction/fragmentation, five underwent post-ESWL ureteroscopy and 29 underwent open ureterolithotomy (nine after failed ureteroscopy). Ureteroscopy was successful in fragmentation/extraction of 19 of 28 (68%) stones and 95% of patients were stone-free at 3 months. All patients who underwent ureterolithotomy and 84% who underwent ESWL (and post-ESWL ancillary procedures) were stone-free at 3 months. All patients who underwent ureterolithotomy, 51% of those who underwent ureteroscopy and 56% of patients who underwent ESWL needed only one treatment. The mean stone burdens of patients in Groups I and II were comparable but more patients presented with larger stones (> 15 mm length, > 100 mm2 surface area) in Group II. The stone-free rates for ESWL monotherapy with ESWL increased from 84% in 1990 to 92% in 1991. A higher proportion of stones were treated in situ in 1991 and a stent was used less frequently in obstructed ureters. Post-ESWL procedures fell from 8% in 1990 to 6% in 1991 and the proportion of patients who required more than one treatment fell from 44% in 1990 to 14% in 1991.

CONCLUSIONS

The choice of treatment for patients with ureteric stones is critical but will vary depending on the individual's circumstances, the availability of equipment, costs and time required to perform the procedure. The results obtained using ESWL for ureteric stones improved considerably over the course of the study as a result of experience and refinement of the technique. Stones located in more difficult systems such as in kidneys with a thin cortex and those located above the ischial spine were no longer subjected to ESWL. Audit of the results obtained following treatment allows identification of problem areas, alerts physicians to alternative methods of treatment and gives an objective quantification of experience, assisting rational decision making with consequent improved success.

Percutaneous transvesical ureteroscopy for removal of distal ureteral stone in reimplanted ureter

In the past two decades, the widespread use of cross-trigonal ureteral reimplants for the treatment of children with vesicoureteral reflux has resulted in a large population of patients with transversely lying ureters. As this population gets older they will consequently be entering an age group at higher risk for stone and urothelial cancer formation, with the potential for diagnostic and/or therapeutic ureteroscopy. The anatomic orientation of the ureters resulting from a cross-trigonal reimplantation may create difficulty or even inability to perform transurethral ureteroscopy. This case presents the technique of percutaneous transvesical ureteroscopy for stone extraction in a seventeen-year-old male with a lower ureteral stone following cross-trigonal ureteral reimplantation. The described technique may serve as an addition to the current endoscopic methods.