Management of Ureteral Calculi: The Impact of Anesthesia-Free ESWL*

Extracorporeal Shockwave Lithotripsy Compared with Ureteroscopy for the Removal of Small Distal Ureteral Stones

INTRODUCTION

The treatment of small distal ureteral stones smaller or equal to 5 mm in size is still highly controversial. In distal ureteral stones larger than 5 mm in size, ureteroscopy (URS) has been shown in many studies to be superior to shockwave lithotripsy (SWL). The objective was to analyze the stone-free rate after treatment of distal ureteral stones with in situ SWL or URS.

MATERIALS AND METHODS

A total of 3,857 SWL treatments were performed at our institution between 1996 and 2001. During this period 45 in situ SWL procedures were performed with the Dornier MFL 5000 lithotripter on distal ureteral stones regardless of the stone size. A total of 262 URS treatments were performed on distal ureteral stones. URS for small (5 mm or less) distal ureteral stones was performed in 110 cases.

RESULTS

Distal ureteral stones smaller or equal to 5 mm in size were treated successfully stone free in 78% in one SWL session. Patients required a second SWL in 14% of the cases and 8% of the patients required a third SWL session. URS patients were successfully stone free after the procedure in 97% of the cases. Failed URS that needed an additional URS were performed in 2 and 1% of the patients had one SWL in situ treatment.

CONCLUSIONS

URS treatment has shown to be the therapy of choice for distal ureteral stones. It is more effective than SWL treatment in this stone location. In experienced hands URS is a safe though even more invasive procedure than SWL. This can be expected as urologists perform more than 40 URS procedures per year.

Cost-effectiveness v patient preference in the choice of treatment for distal ureteral calculi: a literature-based decision analysis

Ureteroscopy (URS) and extracorporeal shockwave lithotripsy (SWL) battle for supremacy in the management distal ureteral calculi. In order to clarify issues surrounding this controversy, we created a decision tree modeling URS or SWL with literature-based probabilities and used as endpoints both cost and patient preferences. Ureteroscopy was more successful than single-session or multiple-session SWL, 92.1% v 74.3% or 84.5%, and had a lower retreatment/complication rate. Although initial SWL was only slightly more expensive than URS, $4,420 v $4,337, the difference increased when the additional costs of complications and retreatment were calculated, $6,745 v $5,555. Using values for an "average" patient, SWL was preferred to URS in terms of patient satisfaction. The most important factors distinguishing between URS and SWL were the success of treatment, the cost of initial therapy, and patient attitudes toward unplanned ancillary procedures and retreatment. Although no alteration of success rates and cost figures within reasonable ranges made URS less cost-effective than SWL, individual differences in patients' aversion for complications allowed URS to be preferred to SWL in some situations. Therefore, SWL is less cost-effective than URS and is not necessarily preferred by patients. The physician should be aware of the principal determinants of the choice between URS and SWL treatment of distal ureteral calculi.

The case for primary endoscopic management of upper urinary tract calculi: I. A critical review of 121 extracorporeal shock-wave lithotripsy failures

OBJECTIVES

To define those patients with upper urinary tract calculi who are more likely to have an unsuccessful outcome from extracorporeal shock-wave lithotripsy (ESWL).

METHODS

A critical prospective analysis of 121 patients, referred to two university centers after ESWL had been exhausted as a treatment modality for upper urinary tract calculi, was performed. Patients were subdivided into the following groups: failure to clear fragments, failure to fragment, difficulty in calculus localization, and failure due to inherent upper urinary tract obstruction. Other important variables include the type of extracorporeal lithotriptor used, number of treatment sittings before referral, calculus location, calculus composition, patient body habitus, and the imaging leading to and associated with extracorporeal therapy.

RESULTS

Large renal calculi (mean, 22.2 mm) and those within dependent or obstructed portions of the collecting system were frequently referred for endoscopic management after failed ESWL. Steinstrasse can be an extremely morbid complication from ESWL and in this series was associated with irreversible loss of renal function and ureteral stricture disease. Extracorporeal lithotripsy of infectious calculi can be associated with severe septic complication. Inadequate preoperative and intraoperative imaging and morbid obesity were also associated with failure. Second- and third-generation lithotriptors were represented in greater numbers than the Dornier HM-3 in this group of ESWL failures.

CONCLUSIONS

ESWL remains the treatment of choice for moderately sized, uncomplicated renal calculi. Large calculi, those within obstructed or dependent portions of the collecting system, and those composed of calcium oxalate monohydrate, frequently fail ESWL. Training in the more technically challenging aspects of endoscopic lithotripsy must be encouraged.

Optimal therapy for the distal ureteral stone: extracorporeal shock wave lithotripsy versus ureteroscopy

Extracorporeal shock wave lithotripsy (ESWL not equal to) is the optimal therapy for renal calculi less than 2 cm. in diameter and for proximal ureteral calculi. Controversy continues over the initial approach to distal ureteral calculi (that is below the bony pelvis): in situ ESWL versus ureteroscopy. Since February 1990, 76 distal ureteral calculi were treated at our institution using either in situ ESWL (Dornier HM3 ESWL with a Stryker frame modification in 27 patients or Siemen's Lithostar electromagnetic ESWL in 22) or ureteroscopy (27 patients). Patient age and stone size were similar among the groups. All ESWL treatments were performed with the patient under intravenous sedation and on an outpatient basis. Stone-free rates were 96% for the HM3 device, 84% for the Lithostar and 100% for ureteroscopy. Retreatment was required in 3 Lithostar cases (14%) and 1 HM3 case (4%). When compared to ESWL ureteroscopy for distal ureteral stones was more time-consuming, entailed routine placement of a ureteral stent, often required general anesthesia, more often led to hospitalization and doubled the convalescence period. From a cost standpoint, ESWL on an HM3 unit was a few hundred dollars more expensive than ureteroscopy. In summary, we believe that in situ ESWL provides optimal first line therapy for distal ureteral calculi, while ureteroscopy is better reserved as a salvage procedure should ESWL fail.

Ureteroscopy: an outpatient procedure?

Ureteroscopy is used in the diagnosis and treatment of many urological conditions. The technique of ureteroscopy has been simplified by the introduction of smaller ureteroscopes and by an increase in the variety of accessory instruments that can be passed through the ureteroscope. Despite those advances, recent reports indicate that ureteroscopy is still generally considered an inpatient procedure. Since 1987 we have performed most of our ureteroscopic procedures on an outpatient basis. We reviewed the records of 176 patients who underwent ureteroscopy between 1988 and 1990, of whom 84 (47.7%) underwent extracorporeal shock wave lithotripsy with the same anesthesia. We treated 134 patients (76.1% of the total group) as outpatients, while 20 (11.4%) chose to remain in the hospital overnight for personal reasons, 10 (5.7%) required additional surgery after ureteroscopy and 12 (6.8%) required hospitalization for preexisting medical problems or for problems that resulted from ureteroscopy. Of the 134 patients who were discharged from the hospital on the day of ureteroscopy only 4 (3.0%) required rehospitalization. The addition of extracorporeal shock wave lithotripsy to ureteroscopy during the same period of anesthesia did not increase the need for hospitalization. Ureteroscopy should be considered an outpatient procedure. The decision to hospitalize a patient after ureteroscopy should be based on preexisting medical problems or on problems that result from ureteroscopy. Routine hospitalization for observation is unnecessary.