Ureteroscopy: results and complications

Treatment of Ureteral Stones Using Holmium:YAG laser

INTRODUCTION

There has been a steady increase in the number of ureteroscopic laser lithotripsy. In addition to its soft tissue applications Holmium:YAG laser has also been found an excellent intracorporeal lithotripter for all kinds of stones. We here present the results of patients treated with Holmium:YAG laser lithotripsy in our clinic.

METHODS

Between June 1997 and December 2002, 205 patients with a diagnosis of ureteric calculi were treated with ureteroscopy using Holmium:YAG laser as an intracorporeal lithotriptor. The stones were localized in the distal ureter in 158 patients (77), middle and proximal ureter in 47 patients (23). Stones ranged in size from 5 x 5 mm to 20 x 10 mm and the operation time was about 35 minutes (ranged 25-65 minutes). Follow-up evaluations have done at first and third months.

RESULTS

The ureteral stone could not be reached in 10 patients (4.8). Stone fragmentation or removal was accomplished in all other patients. Four patients (1.9) had proximal migration of the fragments and later treated with extra corporeal shock wave lithotripsy, and three patients (1.5) had ureteral perforation. They were managed by double J stent placement. Two of the patients had ureteral obstruction on the third month of procedure. One of the patients was treated with open surgery. For the other one, ureteroscopic balloon dilatation was performed and catheterized by double J stent and there wasn't any complication after the removal of stent.

CONCLUSIONS

Ureteroscopic Holmium:YAG laser lithotripsy is a safe, technically feasible and efficacious treatment for ureteral stones.

Management of ureteric stones

The contemporary management of ureteric stones is reviewed and evidence based recommendations about treatment are made. Stones measuring less than 4mm in diameter have a high chance of spontaneous passage and the main debate for optimum treatment of larger stones centres around the choice of shock wave lithotripsy or endoscopic management combined with laser fragmentation. Treatment recommendations should be based on patient preference, published evidence, local audit (surgeon expertise and availability of equipment) and cost. Artificial Neural Networks could become a useful tool for prediction of treatment outcome for ureteric stones, and further research is needed to clarify this potential. ESWL is less effective than ureteroscopy but it may prevent the need for more invasive treatment in a substantial proportion of patients. It should only be considered as initial treatment in patients with stones less than 10mm in size. The routine use of stents should be avoided as both fragmentation and stone free rates are noticeably lower. For larger stones, initial laser ureteroscopy serves better both for proximal or distal calculi and is more cost-efficient. Provided that no contraindications for general anaesthesia exist, laser ureterolithotripsy should be regarded as an excellent first line treatment modality for ureteric stone especially in greater stone burden. In the best hands, the outcome for endoscopic management of ureteric stone in all sites is better than ESWL and is cheaper, although equipment, expertise and experience are all required to achieve this superior outcome.

Complications of ureteroscopy

Ureteroscopy has undergone a dramatic evolution over the last two decades. Although ureteroscopic injury is the most common cause of ureteral trauma because of the large number of ureteroscopic procedures performed, improvements in instrumentation and technique have resulted in a reduced incidence of serious complications. Despite significant technologic advances, however, surgical misadventures still occur, some of which have lasting consequences. Careful attention to instrument selection and surgical technique are critical to reduce untoward events related to ureteroscopy. As such, adverse sequelae associated with ureteroscopy should be related to the underlying pathology itself rather than to the treatment.

Ureteral avulsion as a complication of ureteroscopy

PURPOSE

Report and review the literature on ureteral avulsion as a rare complication of ureteroscopy.

MATERIALS AND METHODS

We analyzed 3 cases of ureteral avulsion in a series of 4,645 ureteroscopic procedures performed from January 1990 to December 2001. We especially report the different managements for this complication.

RESULTS

Due to the different extent of the injury, each patient was treated in a particular way, including a patient managed by means of an endourological approach.

CONCLUSIONS

When performing ureteroscopy or using Dormia baskets, one should always bear in mind the possibility of serious complications, including ureteral avulsion or perforation. The use of an extremely careful technique of ureteral insertion, the mandatory placement of a safety guidewire, and a working guidewire, all minimize the risk of untoward events.

Complicaciones de la uretero-renoscopia

INTRODUCTION

Since its clinical introduction ureteroscopy (URS) has experienced an impressive development due to the technical improvements of new and smaller urological armamentarium. Currently, ureteroscopy is a worldwide procedure with a varied number of diagnostic and therapeutic possibilities. However, the technique has complications.

MATERIAL AND METHODS

We analyse the complications of URS in a series of 4.645 ureteroscopic procedures performed from january 1990 to december 2001, 2972 (64%) female and 1673 (36) male. The objectives of URS were diagnostic (haematuria) and therapeutic (ureteral stones, tumors, strictures and placement of stents).

RESULTS

Fever was the most frequent complication (11.7%), with sepsis in 15 patients. Another complications were: ureteral perforation (1.2%), ureteral avulsion (0.06%), renal injury (0.04%), extrusion (0.4%) and uretero-iliac fistulae (0.02%). The most common treatment was conservative with endourological approach.

CONCLUSION

Carefully performed ureteroscopy is a superb tool for the urologist either for diagnostic or therapeutic purposes with a low ratio of complications. The majority of these complications can be solved with conservative management.

Comparision of intracorporeal lithotripsy methods and forceps use for distal ureteral stones: seven years experience

OBJECTIVES

To evaluate and to compare the safety and efficacy of ureteroscopic lithotripsy methods and forceps use for distal ureteral stones.

MATERIALS AND METHODS

514 patients were evaluated retrospectively who were treated by dye laser, electrohydraulic or ultrasonic lithotripsy or direct forceps extraction for distal ureteral stones between May 1992-October 1999.

RESULTS

Laser lithotripsy was determined to be the most effective method with 86.9% success, while ultrasonic lithotripsy was the least effective method with 77.3% success rate. For smaller stones forceps extraction had a 88.5% success rate.

CONCLUSION

Ureteroscopic lithotripsy methods are all alternative choice of treatment methods in distal ureteral stones. To our experience, laser lithotripsy is the most effective method of all intracorporeal lithotripsy methods as far as the success and complication rates are concerned.

Flexible ureterorenoscopy for the treatment of refractory upper urinary tract stones

OBJECTIVE

To report our experience of using flexible ureterorenoscopy for upper urinary tract stones.

PATIENTS AND METHODS

Thirty-seven patients (13 females, 24 males, mean age 48 years, range 10-76) with upper urinary tract stones not responding to other treatments had their residual symptomatic stones treated through a 9.3 F flexible ureterorenoscope. Electrohydraulic lithotripsy (EHL) was used to fragment the stones and a basket or a grasper used to retrieve the fragments.

RESULTS

Twenty-three patients were completely freed of stone and a further five had asymptomatic residual fragments of < 5 mm. Of 15 patients with ureteric stones, 14 were rendered stone-free at the end of the procedure and 14 of the 22 patients with kidney stones were treated successfully; 80% of the lower calyceal stones were treated successfully and a firm decision was possible on the further management of the remaining stones. There were no major complications.

CONCLUSION

Flexible ureterorenoscopy should be considered in patients with symptomatic upper ureteric or renal stones refractory to other treatments, but the instrumentation is expensive and delicate, and its use should be reserved for such cases.

Secondary ureteroscopy: results and management strategy at a referral center

PURPOSE

In an era when extracorporeal shock wave lithotripsy occupies a dominant place in the treatment of urolithiasis ureteroscopy retains an important role in certain circumstances. While often a definitive procedure, ureteroscopy can be associated with potential risks and complications. The treatment of patients who have undergone a failed attempt at ureteroscopic stone retrieval or have a complication may be complex. As a tertiary care stone referral center we review our experience with performing salvage ureteroscopy following a previous unsuccessful attempt at endoscopic stone removal.

MATERIALS AND METHODS

Between May 1990 and February 1996, 79 patients were referred following an unsuccessful attempt at retrograde endoscopic or basket manipulation for ureteral calculi. A retrospective review of the outcomes of these patients was conducted. Of the patients 11 presented with associated complications, which included ureteral perforation (4), intramural false passage (1) and fever or sepsis (6). Complications were managed by early establishment of urinary tract drainage by stenting or nephrostomy. Among patients without complications elective salvage ureteroscopy was performed.

RESULTS

Ureteroscopy was used in 79 patients with a successful outcome (stone-free) in 75 (95%). Followup imaging with renal ultrasound or excretory urography at least 3 months after secondary ureteroscopy was available in 65 patients and showed no evidence of hydronephrosis or delayed stricture formation.

CONCLUSIONS

Treating the patient who undergoes a failed attempt at ureteroscopy may be problematic and requires access to a wide array of endourological equipment. Each subsequent treatment should be individualized with consideration given to stone size, location and general health. In the presence of a ureteral injury establishment of early urinary tract drainage is essential. Following stabilization, secondary ureteroscopy can be performed yielding high stone-free rates with minimal complications.

Flexible ureteroscopy: Washington University experience with the 9.3F and 7.5F flexible ureteroscopes

PURPOSE

Recent advances in the design of flexible ureteroscopes have resulted in smaller caliber instruments. We review our experience with the smaller flexible ureteroscopes, and compare the efficacy and efficiency of the newer 7.5F to the standard 9.3F flexible instruments.

MATERIALS AND METHODS

Between January 1991 and 1995, 69 male and 41 female patients (mean age 57 years, range 16 to 91) underwent 116 retrograde flexible ureteroscopic procedures for a variety of diagnostic and therapeutic indications. A 9.3F ureteroscope (group 1) was used in 71 patients and a 7.5F instrument (group 2) was used in 39.

RESULTS

Patients in group 2 received sedation analgesia significantly more often than those in group 1 (56 versus 35%, p = 0.04). Active dilation of the ureteral orifice was required less often in group 2 (22.5%) than in group 1 (58%, p < or = 0.05). The total success rate for stone management, and diagnosis and/or treatment of an upper urinary tract lesion was 98.3 and 100%, respectively, in group 1, and 90 and 100%, respectively, in group 2 (p = 0.17). Of the 71 patients in group 1, 17 (24%) were treated on an outpatient basis, compared to 14 of 39 (49%) in group 2 (p = 0.16). No intraoperative or postoperative major complications were encountered in either group. Group 2 required less postoperative analgesia (p = 0.05). No ureteral stricture occurred in either group at an average followup of 9.5 months postoperatively (range 2 to 35).

CONCLUSIONS

For ureteral and renal pathological conditions the 7.5F ureteroscope is as effective as the 9.3F instrument diagnostically and therapeutically. The 7.5F ureteroscope usually can be used with sedation analgesia. Also, the smaller 7.5F ureteroscope is associated with less need for active ureteral dilation, minimal postoperative discomfort and a brief hospital stay.

The role of ureteroscopy as a diagnostic and therapeutic tool in various indications

Ureteroscopy is now in routine use for the diagnosis and treatment of various pathologies in the upper urinary tract. We report here on our experience in diagnostic and therapeutic applications of the 11.5 F rigid ureteroscope in 85 patients and 88 ureters. An overall success rate of 68.18% (60/88) was achieved when therapeutic and diagnostic interventions were evaluated together. Success rate was 66.65% in the treatment of ureteral stones (all locations), 100% in the removal of retained catheters, and 81.82% in diagnostic interventions. Frequencies of complications like postoperative fever, stone migration, and various degrees of ureteral perforation were 5.68%, 5.68%, and 7.95%, respectively, consistent with current literature. We conclude that rigid ureteroscopy can be safely applied for appropriate indications in the hands of competent urologists.

The management of clinically unconfirmed positive urinary cytology

An aggressive evaluation of extravesical sites of disease in patients with clinically unconfirmed positive urinary cytology findings is indicated only in previously untreated asymptomatic or symptomatic patients (group 1) and in those with a complete response to intravesical therapy who are without evidence of disease for 1 year (group 4). Patients who have positive urinary cytology findings immediately after complete transurethral resection of bladder tumors or intravesical therapy will almost always have recurrent bladder transitional cell carcinoma and do not require aggressive extravesical evaluation initially. Transurethral resection prostate biopsy between the 5 and 7 o'clock positions along the entire length of the prostatic urethra is the technique of choice for detecting transitional cell carcinoma of the prostate, since other less invasive techniques frequently underestimate the extent of disease. In the absence of radiographic disease, bilateral ureteral lavage cytology is the technique of choice to identify the upper tract as the source of a positive urinary cytology result. Rigid and flexible ureteropyeloscopy should be performed only in the presence of radiographic or cytological evidence of upper tract transitional cell carcinoma, or in patients with a history of upper tract disease who have suspected relapse on the basis of a positive urinary cytology result.

Lasertripsy of upper urinary tract calculi after unsuccessful extracorporeal lithotripsy or ureteroscopy: comparison with primary lasertripsy

Lasertripsy of upper urinary tract calculi after unsuccessful extracorporeal lithotripsy (SWL) or ureteroscopy (Group 1; N = 26 patients, 36 calculi) was compared with primary lasertripsy (Group 2; N = 56 patients, 79 calculi). Access to calculi was achieved by a Candela miniscope or flexible ureteroscope, and laser fragmentation was performed with the Candela pulsed-dye laser. Laser alone or laser plus 1.9F basket extraction produced a stone-free rate of 80.6% in Group 1 and 79.8% in Group 2. Additional treatment methods were needed in similar proportions of both groups and in most patients consisted of SWL of fragments displaced into the kidney. The laser fragmentation failures rates were 2.8% in Group 1 and 7.6% in Group 2. One-month stone-free rates and major complication rates were similar in the two groups. Lasertripsy after unsuccessful SWL or ureteroscopy was as effective as primary lasertripsy.

Endopyelotomy and endoureterotomy with the acucise ureteral cutting balloon device: preliminary experience

Endoureterotomy and endopyelotomy usually involve an endoscopic antegrade approach. In an effort to simplify this technique, we designed an 8-mm balloon catheter with a 100-microns electrocautery cutting wire (Acucise) for retrograde incision of the ureter under fluoroscopic control. Twenty-eight patients with ureteral or ureteropelvic junction obstruction of 3.5 cm or less underwent Acucise endoureterotomy or endopyelotomy. The average operating time was 100 minutes, and the average hospital stay was 2.6 days. Follow-up was obtained with a subjective symptom score, intravenous urography, diuretic renal scan, a Whitaker test, or various combinations thereof. All patients had a minimum of 3 months of follow-up (mean 3.8 months; range 3-9 months). Overall, of the 21 patients who had symptoms of upper tract urinary obstruction, 14 (67%) had complete resolution, and another 4 (19%) had partial resolution, of their symptoms. Postoperative studies demonstrated normal upper tracts in 71% and improvement in another 14% of the patients. In our experience, the Acucise ureteral cutting balloon device provides an effective and efficient means for performing a retrograde endoureterotomy or endopyelotomy.

Clinical experience with flexible ureteropyeloscopy

Flexible ureteroscopes and their accessory working instruments have undergone tremendous design advances since the earliest reports in the 1960s. These changes have allowed for the expansion of indications for flexible ureteroscopy with the emphasis now on therapeutic and not just diagnostic applications. This report covers 290 procedures done with actively deflectable, flexible ureteroscopes on 222 patients. Followup averaged 11.2 months in 228 patients, while the remaining 62 were followed by the original referral center. Included were 154 procedures for stones and 79 for tumors or filling defects. Of the procedures 149 were performed with the patient under local anesthesia with sedation, while 128 were done with use of general anesthesia. The procedure was done in only 22% of the cases for purely visual diagnosis without any interventional manipulation. More than 42% of the cases involved stone retrieval or lithotripsy, in which case the laser was most commonly used (56 cases). The total success rate was 95.5%, and the most common complications were colic or pain in 9% and fever in 6.9%. A stricture developed in 2 patients. A stent was left in more than 93% of the patients and the usual postoperative stay was less than 3 days. With the introduction of even more improved instruments, flexible ureteroscopy should continue to gain ground as an option for the management of upper urinary tract pathology.

Endopyelotomy: comparison of ureteroscopic retrograde and antegrade percutaneous techniques

To date 2 approaches have been developed for performing endopyelotomy, that is the antegrade and retrograde approaches. Experience with antegrade transnephrostomy endopyelotomy is quite large and the results have been excellent. However, the need for percutaneous nephrostomy and prolonged hospitalization have been 2 drawbacks to this approach. In contrast, experience with retrograde transureteral endopyelotomy is scant. However, a ureteroscopic approach is attractive from the standpoint of eliminating the need for a large nephrostomy tube and because of the possibility of performing this procedure on an outpatient basis or during a short hospital stay. We report our experience with antegrade and retrograde endopyelotomy in 41 patients. The hospital stay (3.4 versus 4.0 days), nephrostomy tube size (8F to 10F versus 20F to 22F) and nephrostomy tube duration (2.9 versus 3.8 days) were all less with the retrograde approach. The initial success rate was similar between the 2 methods: 79% (retrograde) versus 78% (antegrade). However, the analgesic requirements (5.3 versus 3.5 doses) and the occurrence of significant complications (that is late ureteral stricture in 20%) were greater with the ureteroscopic approach. With the methods currently available, we believe that antegrade endopyelotomy is the preferred approach for endopyelotomy.

In situ prone ESWL for the treatment of lower ureteral stones: experience with 28 patients

Twenty-eight patients with lower ureteral stones underwent in situ extracorporeal shock wave lithotripsy (ESWL) in the prone position over the period of 7 months between March 1990 and September 1990. For stone disintegration the spark gap shock wave lithotripter Tripter XI (Direx) was used. Satisfactory disintegration was achieved in 93 per cent of patients. The stone-free rate at 12 weeks was 82 per cent, and 11 per cent had residual fragments less than or equal to 4 mm in diameter. Twenty-one per cent of patients required repeat treatments. For only 2 patients general anaesthesia was required (7 per cent). There were no remarkable complications except for haemospermia which resolved spontaneously 15 days after treatment. It was concluded that in situ prone ESWL is an effective and safe procedure for the treatment of lower ureteral stones.

Ureteroscopy without routine balloon dilation: an outcome assessment

A retrospective analysis of 156 rigid ureteroscopic stone procedures in 145 patients revealed successful manipulation in 90%. The stone-free rate after adjunctive procedures was 95%. Access was achieved without balloon dilation in all but 18 patients. There were 24 perforations, occurring in 31% of proximal, 8% of mid ureteral and 8% of distal stone manipulations. Of the evaluable patients 63% underwent radiographic assessment for stricture disease, 75% at 6 months or more after the procedure. The stricture rate was 3.5% in all patients and 5.9% in patients with perforations. Of 37 patients evaluated for vesicoureteral reflux only 1 had reflux. Questionnaire followup was obtained for 74% of the patients (mean followup 2.6 years) and 32% felt normal within 3 days. Postoperative symptoms included flank pain (13%), renal colic (12%), pelvic discomfort (30%) and Double-J stent related complaints (49%). Of the patients 15% have reported recurrent stones. Ureteroscopy is effective and well tolerated, and it has minimal long-term complications.

Ureteral calculi: natural history and treatment in an era of advanced technology

Patients with ureteral stones may be managed expectantly, or treated with a variety of invasive and noninvasive techniques depending on stone composition, size and location, expectations of the patient and experience of the surgeon. Of 378 patients with documented ureteral calculi 60% passed the stones spontaneously. Passage rates from the proximal, middle and distal ureter were 22, 46 and 71%, respectively. Basketing under fluoroscopic control of distal stones was successful in 79% of the attempts and for those in whom this approach failed ureteroscopy was performed, with a success rate of 90%. When ureteroscopy was used as the initial treatment of distal stones removal was achieved in 81% of the patients. These statistics serve as a reminder that traditional therapy of ureteral stones has not lost its role in contemporary practice.

The use of percutaneous diversion during pregnancy

Two patients with infected hydronephrosis and one patient with calculus anuria during pregnancy were managed initially by percutaneous nephrostomy. Maintenance of percutaneous diversion allowed continuation of pregnancy to term and effectively preserved renal function. Definite surgical treatment for the obstructive pathology was done electively in the postpartum period.

Laser ureterolithotripsy with combined rigid and flexible ureterorenoscopy

Because the pulsed dye laser can be transmitted through a thin, flexible quartz fiber a small caliber ureteroscope and flexible ureterorenoscope are applicable. Therefore, the use of a rigid or flexible ureterorenoscope was combined with laser lithotripsy to treat upper urinary tract calculi. All 14 ureteral stones below the pelvic brim were removed successfully with a rigid 7.2F (outer diameter) ureteroscope and 14 of 16 stones above the pelvic brim were removed with a flexible ureterorenoscope. Laser monotherapy was effective in 24 cases and the complementary use of forceps or electrohydraulic lithotripsy was required in 4. Two stones were lost from the visual field during endoscopic manipulation. There was no complication requiring surgical correction. The combined use of these instruments is highly successful and safe for the treatment of upper urinary tract calculi.

Ureteral irrigation during ureteroscopy: the rapid infusion system

The use of a rapid infusion system during ureteroscopy has facilitated introduction of the ureteroscope into the ureter and has enhanced the quality of vision, thus, making the procedure more efficient. No complications have been observed with the use of this device.

Long-term results of transurethral lithotripsy with the rigid ureteroscope: injury of intramural ureter

We treated 208 patients with ureteral calculi via transurethral lithotripsy using the rigid ureteroscope between March 1985 and April 1988. A total of 220 ureteroscopic procedures was performed in 217 ureters. Complete removal was achieved after 180 procedures (81.8%) and incomplete removal was achieved after 9 (4.1%). In 31 cases (14.1%) the stone could not be removed because of various reasons. Ureteral disruption was observed in 1 case (0.5%), which was treated successfully with reconstruction. Ureteral perforation occurred in 15 cases (6.8%) and was treated successfully except for 1 patient (0.5%) in whom ureteral stricture was observed requiring reconstruction. From long-term followup of sequential excretory urography and voiding cystography, mild stricture at the vesical end of the ureter was noted in 3 of 86 ureters (3.5%) and vesicoureteral reflux was noted in 7 of 73 (9.6%). These results indicate that the injury to the intramural ureter might arise from the passage of the ureteroscope resulting in stricture and vesicoureteral reflux.

The role of open stone surgery since extracorporeal shock wave lithotripsy

Of 893 stone procedures 37 (4.1 per cent) performed during the first 19 months after extracorporeal shock wave lithotripsy was instituted at our medical center were open operations. Procedures included ureterolithotomy in 23 patients (with simultaneous pyelolithotomy in 1), anatrophic nephrolithotomy in 8, pyelolithotomy in 3 (with concomitant pyeloplasty in 2), partial nephrectomy in 2 and nephrolithotomy with a bowel segment inlay in 1. The most common reasons for electing an open operation were unsuccessful endoscopic stone manipulation, presence of anatomical obstruction in the intrarenal collecting system or ureter, morbid obesity and underlying medical problems precluding lengthy repeated endourological procedures. Over-all surgical results were excellent. Our study indicates that patients who presently require an open stone operation have complex calculous disease associated with a variety of anatomical and physiological problems. Despite this finding good results may be attained.

Flexible ultrasonic lithotriptor and fiberoptic ureterorenoscope: a new approach to ureteral calculi

A newly developed flexible ultrasonic lithotriptor has been used with a fiberoptic ureterorenoscope for removal of upper ureteral and kidney stones. There was an 87.5 per cent success rate in 16 patients. This technique can be used safely and effectively to remove mid and upper ureteral stones not amenable to extracorporeal shock wave lithotripsy or the rigid ureterorenoscope.

Is extracorporeal shockwave lithotripsy suitable treatment for lower ureteric stones?

Forty patients with lower ureteric calculi for which intervention was considered desirable have been treated by in situ extracorporeal shockwave lithotripsy (ESWL) on the Dornier HM3 Lithotripter using a modified technique. Stone localisation was satisfactory in all patients. Adequate disintegration was achieved in 90% of patients following one treatment; 34 patients have been followed up for at least 3 months and 27 of these are stone-free (79%). Treatment failed in 4 patients and 2 of these had dense lower ureteric stone streets as a result of previous ESWL. The retreatment rate, post-treatment auxiliary procedure rate and complication rate were minimal. It was concluded that in situ ESWL is an effective and safe method for treating certain selected lower ureteric stones and should be considered as a feasible alternative to the more conventional methods of treatment.

Changing surgical aspects of urinary stone disease

Surgical management of urinary calculous disease has changed dramatically in the past decade. The development of percutaneous nephrostomy techniques has allowed new access to upper tract stones. Percutaneous removal of large calculi was made possible by the development of ultrasonic and electrohydraulic lithotripsy. All upper tract calculi can now be removed in 70 to 100 per cent of cases with minimal complications. Nephrostolithotomy has reduced transfusion rates and hospitalization costs and has markedly shortened convalescence periods compared with open surgery. Ureteroscopy followed nephrostolithotomy as advanced fiberoptic technology allowed the development of the small-caliber instruments required for this procedure. With experience, successful stone retrieval has occurred in 90 per cent or more of cases, again with minimal complications. As nephrostolithotomy and ureteroscopy have become available, the subspecialty of endourology has emerged and significantly changed the management of urinary tract calculi. Perhaps the most significant advance in stone therapy has been the design and implementation of extracorporeal shock wave lithotripsy. With this noninvasive technique, most renal and proximal ureteral calculi can be effectively treated with minimal morbidity and convalescence. Research in lithotripter design is continuing, with more advanced and effective machines on the horizon. The applicability of extracorporeal therapy for the treatment of biliary tract calculi is currently under investigation. Finally, one should not disparage medical therapy for recurrent nephrolithiasis. A comprehensive metabolic evaluation combined with selective medical therapy provides almost complete relief from recurrent stone formation and makes medical therapy an integral component of treating the patient with renal or ureteral calculi.

Use of a prototype 3F electrohydraulic electrode with ureteroscopy for treatment of ureteral calculous disease

A 3F electrohydraulic electrode was used with flexible ureteroscopy to treat upper urinary tract calculi in 18 patients. Of 21 procedures performed 10 involved retrograde passage of the ureteroscope and 11 consisted of antegrade procedures with percutaneous nephrostomy access. Complete fragmentation was achieved in 19 of the 21 procedures. In 1 patient bilateral renal caliceal diverticular calculi were treated with the electrohydraulic electrode used to open initially the diverticular orifice. Minor complications included retained stone fragments and small ureteral perforations. No serious complications resulted from the lithotripsy and no patient required an open operation. Flexible ureteroscopy, retrograde or antegrade, appears to offer access to upper tract stones not treated reliably with rigid ureteroscopy. Electrohydraulic lithotripsy with this small 3F probe appears to be a safe and effective means to treat upper urinary tract stones.