Treatment of 150 ureteric calculi with the Lithoclast

Inadvertent Stone Migration During Pneumatic Lithotripsy: Still a Conundrum in the 21st Century

Currently, an ideal gadget to stop retrograde stone migration remains a holy grail, and the hunt for such a device is still ongoing in the 21st century. The quest for an ideal instrument is driven by the need to reduce cost, minimize ancillary procedure rates, reduce the device's operative time, and improve the stone-free rate. The purpose of the present review is to provide an update on the use of preventive measures that are used to stop retrograde stone migration during pneumatic lithotripsy for ureteric stone management.

Dual usage of a stone basket: Stone capture and retropulsion prevention

INTRODUCTION

Stone migration during ureteroscopy (URS) for proximal ureteric calculi is a constant challenge. Several retropulsion prevention devices have been developed to optimize URS outcomes. Our technique involves capturing the stone within a four-wire Nitinol stone basket and then performing laser lithotripsy to dust the stone while it is engaged in the basket. The dusted fragments wash out with the irrigation fluid and once small enough, the remaining stone is removed intact.

METHODS

A retrospective chart review was performed of all proximal semi-rigid URS procedures for a solitary calculus (2000-2016). We compared our new technique introduced in 2010 to URS control procedures that did not use retropulsion prevention techniques or devices.

RESULTS

One hundred and forty patients underwent URS for proximal ureteric calculi. Mean stone diameter was 9.3±3.4 mm, with similar impaction rate between both groups (44.1% vs. 43.1% control; p=n/s). The mean surgical procedure time was 53.3±17.9 minutes for the new technique and 65.2±29.2 minutes for the control group (p=0.005). Compared to the new technique, the control group had a higher rate of retropulsion (33.3% vs. 14.7%; p=0.01) and required flexible URS more often to exclude or remove residual fragments (24.1% vs. 59.1%; p=0.001). Using the new technique, stone-free rates were higher (79.1% vs. 69.4%; p=n/s) and there was a lower likelihood of leaving residual fragments both <3 mm and ≥3 mm (p=0.001).

CONCLUSIONS

Our novel technique results in shorter operative times, lower retropulsion rates, and decreases postoperative residual stone fragments.

Modified Access Sheath for Continuous Flow Ureteroscopic Lithotripsy: A Preliminary Report of a Novel Concept and Technique

OBJECTIVE

To improve the safety and efficacy of ureteroscopic lithotripsy for the treatment of ureteral stone, we made a simple modification to the standard ureteral access sheath (mUAS) and developed a novel technique to overcome the deficiencies of the current procedure.

MATERIALS AND METHODS

We added an oblique suction-evacuation port with pressure regulating mechanism to the UAS to allow active egress of irrigation fluid and stone fragments. A pressure vent was placed on the egress port. Continuous negative pressure aspiration was connected to the egress port, whereas the continuous irrigation was delivered through the endoscope with a pressure pump. Stone fragmentation was performed using a holmium-YAG laser through a semirigid ureteroscope. Tiny stone fragments were evacuated in the space between the sheath and the scope. When larger fragments came into the sheath that were too large to exit between the scope and the sheath, the scope was withdrawn to just proximal to the bifurcation of the oblique port. This opened up an unimpeded egress channel for the larger fragments. We attempted this procedure in 104 consecutive patients.

RESULTS

Seventy-four patients had effective insertion of mUAS. Seven patients failed semirigid ureteroscopy despite effective placement of mUAS. Patient with effective semirigid ureteroscopic lithotripsy had 100% immediate stone clearance and no observed stone retropulsion. Patients who failed semirigid ureteroscopy were converted to flexible ureteroscopy. Five patients had completed stone clearance. The overall immediate stone-free rate was 97.3% and 100% at 1-month follow-up. Complications included two fevers and one minor ureteral false passage.

CONCLUSIONS

Our modification of UAS has reduced stone retropulsion, improved stone clearance, improved visual field, and probably reduced the intraluminal pressure.

Safety and efficacy of using the stone cone and an entrapment and extraction device in ureteroscopic lithotripsy for ureteric stones

Objective

To assess the safety and efficacy of using a stone cone and an entrapment and extraction device (N-Trap®, Cook Urological, Bloomington, IN, USA) to avoid stone retropulsion during ureteroscopic lithotripsy for ureteric stones.

Patients and methods

This retrospective comparative study included 436 patients treated with ureteroscopic lithotripsy for a single ureteric stone from February 2011 to January 2014. The diagnosis of a stone was confirmed by plain spiral computed tomography in all cases. Patients were divided according to the ureteric occlusion device applied to avoid stone retropulsion during pneumatic lithotripsy into three groups; group 1 (156) had no instruments used, group 2 (140) in whom the stone cone was applied, and group 3 (140) in whom the N-Trap was used. Patient demographics, stone criteria, operative duration and complications, and success rates (complete stone disintegration with no upward migration) were reported and analysed statistically.

Results

The stone was in the lower ureter in >55% of patients in all groups. The mean (SD) of maximum stone length was 9.8 (2.5), 10.4 (2.8) and 9.7 (2.9) in groups 1–3, respectively. The use of the stone cone or N-Trap did not significantly increase the operative duration (P = 0.13) or complication rates (P = 0.67). There was a statistically significant difference (P < 0.001) favouring groups 2 and 3 for retropulsion and success rates, being 83.3% in group 1, 97.1% in group 2 and 95.7% in group 3.

Conclusion

The stone cone and N-Trap gave high success rates in preventing stone retropulsion during ureteric pneumatic lithotripsy. Both devices caused no increase in operative duration or complications when used cautiously.

Application of the Holmium Laser Lithotripsy for Bladder Stones under Local Anaesthesia: A Prospective Analysis

Purpose

The purpose of this study is to determine the feasibility and the results of intracorporal holmium laser (HL) lithotripsy in patients with bladder calculus under local anaesthesia.

Materials and methods

From January 2009 to August 2012, 46 patients underwent HL lithotripsy for bladder calculus under local anaesthesia. Twelve patients who had associated medical comorbidity also underwent the procedure. The pain was evaluated with 10-point visual analogue scale during and 1 h after completion of the procedure. Foley catheter was inserted at the end of procedure in all the patients.

Results

In the present study, the mean stone size was 2.1 cm (1.1–4.2 cm) and the mean operative time was 43 min (range 23–57 min). All patients were rendered stone-free in a single sitting except one patient. The mean pain score intraoperatively and in the postoperative period was 3.84 and 1.47, respectively. There was no major complication during surgery. The procedure was well tolerated and most of the patients were discharged on the same day. After the follow-up period of 3 months, all patients were asymptomatic except one patient who developed a soft stricture in the bulbar urethra and was managed by internal urethrotomy.

Conclusions

Bladder stones can be safely managed by HL lithotripsy under local anaesthesia with a high success rate and minimal morbidity. The procedure is even feasible in high-risk patients with medical comorbidities without extra risk.

Pneumatic versus laser ureteroscopic lithotripsy: a comparison of initial outcomes and cost

PURPOSE

To audit the cost of laser versus pneumatic semirigid ureteroscopic lithotripsy and to analyze their relative initial outcomes and cost.

METHODS

Hundred and eighty-seven patients who underwent semirigid ureteroscopic lithotripsy were analyzed retrospectively in terms of age and sex of the patients; location and size of the stones; the type of probe and ancillary equipment such as guide wire, basket catheter, JJ stent requirements; irrigation amount; operation time; the cost of the anesthesia and further treatments such as a JJ stent removal operation and shock wave lithotripsy requirements and their costs. Two groups were formed based on this type of lithotripters, pneumatic and laser lithotripsy.

RESULTS

Operation times (min.) in terms of the stone size, for stones <100 and >100 mm(2) were 20.75 ± 10.78 and 25.82 ± 14.23, respectively (p = 0.007). Operation times for the pneumatic and laser groups were 33.05 ± 11.36 and 15.25 ± 6.14, respectively (p < 0.05).The stone-free rates for pneumatic and laser groups were 89.6 % (n = 69) and 98.2 % (n = 108), respectively (p = 0.01). The mean cost of the operations for each of the study groups was 261.5 ± 66.13 and 311.7 ± 51.97 US$, respectively (p = 0.001). The mean cost in terms of the stone size, for stones <100 and >100 mm(2), was 272.86 ± 53.05 and 323.71 ± 66.88 US$, respectively (p = 0.01).

CONCLUSIONS

It seems that usage of laser lithotripsy (LL) in patients with ureteral stones is more effective than pneumatic lithotripsy (PL) in terms of operation time and SF rate. On the other hand, the mean cost of LL seems to be more expensive than PL. Urologists should think these parameters before the choice of these two treatment modalities. The higher the effectiveness, the greater the cost.

Damage of stone baskets by endourologic lithotripters: a laboratory study of 5 lithotripters and 4 basket types

Background. In some cases, the ureteral stone is simultaneously stabilized by a stone basket when endourologic lithotripsy is performed. This stabilization can be either on purpose or by accident. By accident means that an impaction in the ureter occurs by an extraction of a stone with a basket. A stabilization on purpose means to avoid a retropulsion of the stone into the kidney during lithotripsy. At this part of the operation, stone baskets have been frequently damaged. This severing of wires can lead to ureteral trauma because of hook formation. Material and Methods. In a laboratory setting, the time and the pulse numbers were measured until breaking the wires from four different nitinol stone baskets by using five different lithotripsy devices. The endpoint was gross visibledamage to the wire and loss of electric conduction. Results. The Ho:YAG laser and the ultrasonic device were able to destroy almost all the wires. The ballistic devices and the electrohydraulic device were able to destroy thin wires. Conclusion. The operating surgeon should know the risk of damagefor every lithotripter. The Ho:YAG-laser and the ultrasonic device should be classified as dangerous for the basket wire with all adverse effects to the patient.

[Use of a polymeric gel to prevent retropulsion during intracorporeal lithotripsy]

INTRODUCTION

Stone retropulsion during ureteroscopic lithotripsy may lead to additional procedures needed for residual calculi. Several devices have been introduced in an attempt to reduce retropulsion. We set out to report our initial experience utilizing the new polymeric gel, BackStop.

MATERIAL AND METHODS

We prospectively collected data on 7 ureteroscopy procedures with distal ureteral calculi treated with BackStop. Perioperative data including stone size, location, operative time, stone free rate, the presence or absence of retropulsion was collected. Success was defined as no residual fragments, no retropulsion, and no additional procedures required.

RESULTS

All of the patients were rendered stone free after URS and no retropulsion occurred. There were no intraoperative complications nor gel migration or problems with dissolving the gel.

CONCLUSIONS

BackStop is a new promising therapy to prevent retropulsion during ureteral intracorporeal lithotripsy. It is safe, easy to apply and very effective in preventing stone fragment migration. BackStop has the potential to reduce operative time.

Holmium: YAG laser lithotripsy versus pneumatic lithotripsy for treatment of distal ureteral calculi: a meta-analysis

The objective of this study was to estimate the treatment effect of Pneumatic Lithotripsy (PL) versus holmium: YAG laser lithotripsy (LL) in the treatment of distal ureteric calculi. A bibliographic search covering the period from 1990 to April 2012 was conducted using search engines such as MEDLINE, EMBASE, and Cochrane library. Data were extracted and analyzed with RevMan5.1 software. A total of 47 studies were scant, and 4 independent studies were finally recruited. Holmium: YAG LL conveyed significant benefits compared with PL in terms of early stone-free rate [odds ratio (OR)=4.42, 95% confidence interval (CI) (1.14, 17.16), p=0.03], delayed stone-free rate [OR=4.42, 95%CI (1.58, 12.37), p=0.005], mean operative time [WMD=-16.86, 95%CI (-21.33, -12.39), p<0.00001], retaining double-J catheter rate [OR=0.44, 95%CI (0.25, 0.78), p=0.004], and stone migration incidence [OR=0.26, 95%CI (0.11, 0.62), p=0.003], but not yet in the postoperative hematuria rate and the ureteral perforation rate according to this meta-analysis. Precise estimates on larger sample size and trials of high quality may provide more uncovered outcomes in the future.

Contemporary management of ureteral stones

CONTEXT

Ureteral calculi represent a common condition that urologists encounter in everyday practice. Several treatment options are available for calculi that do not pass spontaneously or are unlikely to do so.

OBJECTIVE

In this nonsystematic review, we summarize the existing data on contemporary management of ureteral stones focusing on medical expulsive therapy (MET) and different treatment modalities.

EVIDENCE ACQUISITION

A PubMed search was performed. We reviewed the recent literature on the management of ureteral calculi. Articles were considered between 1997 and 2011. Older studies were included selectively if historically relevant.

EVIDENCE SYNTHESIS

For stones that do not pass spontaneously or with MET, shock wave lithotripsy (SWL) and ureteroscopy (URS) are the most common and efficient treatment modalities. Both techniques have obvious advantages and disadvantages as well as different patterns of complications. For select cases or patients, other modalities may be useful.

CONCLUSIONS

Ureteral stones of up to 10mm and eligible for observation may be offered MET. For most ureteral calculi that require treatment, advances in SWL and URS allow urologists to take a minimally invasive approach. Other more invasive treatments are reserved for select "nonstandard" cases.

A comparison of Stone Cone versus lidocaine jelly in the prevention of ureteral stone migration during ureteroscopic lithotripsy

BACKGROUND

Intracorporeal lithotripsy modalities and stone removal devices have been created to facilitate endoscopic management of ureteral stones. These devices, along with improved techniques, have resulted in stone-free rates greater than 95% with low morbidity. However, problems remain that preclude consistent 100% stone-free rates with endoscopic treatment of ureteral calculi. Retrograde migration during ureteroscopic procedures remains a significant problem.

OBJECTIVES

The aim of this study was to compare the Stone Cone device and instillation of lubricating lidocaine jelly as two methods to prevent retrograde stone migration during ureteroscopic lithotripsy.

PATIENTS AND METHODS

This study included patients suffering from ureteral stones that were treated with intracorporeal lithotripsy using the pneumatic Lithoclast. These patients were divided into two groups. In group I, the Stone Cone device was used, while in group II, lidocaine jelly 2% concentration was used.

RESULTS

This study included 40 patients with a mean age of 38.6 ± 9.3 years (20 patients in each group). There was no significant difference between the groups with regards to stone site, size or state of the upper urinary tract by excretory urography. The pneumatic Lithoclast allowed successful fragmentation of all calculi into small fragments. Upward stone migration did not occur in patients in the Stone Cone group, while in the lidocaine jelly group it occurred in three patients (15%). The operative time in the Stone Cone group ranged between 30 and 55 minutes (mean, 41.8 ± 5.3), while in the lidocaine jelly group it ranged between 40 and 71 minutes (mean, 51.4 ± 3.4), and this difference was statistically significant (p < 0.05).

CONCLUSION

The Stone Cone is safe and efficient in preventing proximal stone migration during ureteroscopic pneumatic lithotripsy. It maintained continuous ureteral access and demonstrated a statistically significant advantage over the lidocaine jelly in terms of proximal stone migration, operative time, and the need for auxiliary procedures.

Emergency ureteroscopic lithotripsy in acute renal colic caused by ureteral calculi: a retrospective study

This work was conducted to evaluate the safety and efficacy of emergency ureteroscopic lithotripsy in patients with ureteral stones. From May 2003 to December 2010, 244 patients (184 men and 60 women, mean age 45.6 ± 12.7 years (range 22-73 years) were treated with emergency ureteroscopic lithotripsy for ureteral calculi. All patients were divided into three groups according to the stone location in the ureter. Intracorporeal lithotripsy when necessary was performed with the Swiss lithoclast. The overall stone-free status was defined as the complete absence of stone fragments at 4 weeks, postoperatively. A double J stent was inserted in selected patients if there was significant ureteral wall trauma, edema at the stone impaction site, suspected or proved ureteral perforation, and if the stone migrated to the kidney. The overall success rate was 90.6%. The success rates were different according to the stone site. The success rate of groups A, B and C was 69.4, 94.8 and 96.6%, respectively. The overall rate of ureteral stent insertion at the end of the procedure was 177/244 (72.5%). The rate of stent insertion was 41/49 (83.7%), 32/46 (69.6%) and 104/149 (69.8%) in groups A, B and C, respectively. The overall complication, failure, and stricture rate was 32/244 (13.1%), 23/244 (9.4%) and 0.8%, respectively. With the recent advances in ureteroscopic technology, intracorporeal probes and stone extraction devices, emergency ureteroscopy is found to be a safe and effective procedure with immediate relief from ureteral colic and ureteral stone fragmentation.

Use of NTrap® during Ureteroscopic Lithotripsy for Upper Ureteral Stones

Purpose

This study aimed to determine the value of the NTrap® (Cook Urological INC, USA), which was designed to block the upward movement of stones during ureteroscopic lithotripsy.

Materials and Methods

We reviewed the data of 144 patients who underwent ureteroscopic lithotripsy for an upper ureteral stone from June 2006 to May 2010. Sixty-eight patients who underwent ureteroscopic lithotripsy without the use of the NTrap® were assigned to Group I and 76 patients who underwent ureteroscopic lithotripsy with the NTrap® were assigned to Group II. The size of the stones, operation time, success rate, and pre- and postoperative complications were compared retrospectively between the two groups.

Results

The mean age of the patients (Group I: 35.8 years; Group II: 32.6 years) and the sex ratios were not significantly different between the two groups. The mean size of the stones was 6.9 mm and 7.4 mm, which also was not significantly different between the two groups. The mean operation time was 82.7 minutes and 78.7 minutes. The operation time was shorter in Group II, but the difference was not significant. The success rate of stone removal was 89.7% and 98.7% in Groups I and II, respectively; Group II showed a significantly higher success rate. Two cases of ureteral perforation and one case of ureteral avulsion occurred in Group I, and one case of ureteral perforation occurred in Group II.

Conclusions

NTrap®, which is an instrument used to assist during ureteroscopic lithotripsy, can be considered to be an effective tool that blocks the upward movement of the stone and aids in safe stone removal.

Stone Cone® in ureteroscopic ballistic lithotripsy of proximal ureteral stones

Stone Cone® (Microvasive-Boston Scientific Corp, USA) is a device which prevents retrograde calculus migration during endoscopic ureterolithotripsy. We have studied the safety and efficacy of this device in endoscopic ureterolithotripsy with ballistic energy in proximal ureteral stones.

Materials and Methods.

From 01/02/2006 to 01/02/2008 we carried out 36 ureterorenoscopies (URS) for proximal ureteral stones (average age: 46, range: 15–73). A ballistic energy was used for stones fragmentation. In 18 patients (Group A) we carried out URS with the aid of Stone Cone®, which was not used in the other 18 patients (Group B). Semirigid 8 Ch or 10 Ch Storz ureteroscope and ballistic lithotriptor Swiss Lithoclast Master EMS® were used. In cases of migration, edema, and ureteral damage, a ureteral stent was used.

Results.

In Group B patients (URS performed without Stone Cone®) the migration of the whole stone, or of clinically significant fragments, occurred 8 times (45%). All of these patients underwent external shockwave lithotripsy (ESWL) at a center equipped with a lithotriptor. A ureteral stent was placed in 14 cases (78%). In Group A, the migration of a stone requiring ESWL treatment occurred only once (5%). The ureteral stent was placed 8 times (45%). We had no significant complications during the procedure.

Conclusions.

The Stone Cone® is a safe and easy-to-use device. The cost of this device can be balanced by the reduction of postoperative ESWL treatments for lithiasic fragments pushing up into the kidneys (p<0.01), and of ureteral stent applications at the end of the procedure (p<0.05).

Risk of collateral damage to endourologic tools by holmium:YAG laser energy

BACKGROUND AND PURPOSE

Today, the holmium:YAG laser is the gold standard in endourologic stone treatment because of its high efficacy. However, guidewires and stone-extraction tools often are close to the fiber and may be damaged accidentally by the laser. The aim of our study was to evaluate the duration of laser application required to disrupt wires at different energy settings.

MATERIALS AND METHODS

Two standard wires (0.035-inch guidewire and 0.025-inch hydrophilic Terumo wire) and two baskets (1.9F Nitinol tipless and 3F stone extraction) were investigated. We used a holmium:YAG laser (Auriga; Wavelight Laser Technologie AG, Erlangen, Germany) and two fibers (230 and 365 microm) at 800 and 2000 mJ and a 5-Hz pulse rate. The laser was brought into direct contact with the wires.

RESULTS

The average time required for transection was 55 to 103 seconds for a safety wire. The Terumo wire broke after 20 to 40 seconds of direct laser application; 15 to 34 seconds was required for a Dormia basket. Thin Nitinol basket wires were disrupted after only 1 to 4 seconds. One- and two-factorial variance analysis showed a high degree of significance (P < 0.0001) of the energy level and type of wire.

CONCLUSION

The disruption of stone-extraction tools occurs in a remarkably short time with laser exposure, especially in case of Nitinol baskets, whereas guidewires are more resistant. Attention should be paid to avoiding contact of laser energy with wires and baskets during stone fragmentation.

A comparison of holmium:YAG laser with Lithoclast lithotripsy in ureteral calculi fragmentation

PURPOSE

Among various intracorporeal lithotriptors, Lithoclast (EMS, Switzerland) has become the widely used tool for the treatment of urinary stones. Recently, the holmium:YAG laser has been used with a wide range of potential urological applications, including intracorporeal lithotripsy of urinary calculi. The purpose of the present study is to compare Lithoclast with holmium:YAG laser lithotripsy in ureteral calculi fragmentation.

METHODS

Out of 51 patients with ureteral calculi, 26 underwent Lithoclast lithotripsy and 25 holmium:YAG lithotripsy using a 8/9.8F rigid ureteroscope. There were no changes to the ureteroscopes, video monitors, baskets or irrigation devices during the study period.

RESULTS

There were no differences in patient age, sex, stone size and location of stones between these groups. The immediate stone-free rates were 96.0% in the holmium:YAG group and 73.1% in the Lithoclast group (P < 0.05). The 3-month stone-free rates were 96.0% and 84.6%, respectively (P = 0.350). The mean operation time and mean period of postoperative hospitalization in the holmium:YAG group (49.8 min and 1.0 days, respectively) were shorter than those of the Lithoclast counterpart (76.9 min and 2.5 days, respectively). Post-treatment complications, such as ureteral perforation, were encountered in only two patients who underwent Lithoclast.

CONCLUSIONS

Holmium:YAG lithotripsy was associated with shorter operation time and postoperative hospitalization period. These data also suggest that holmium:YAG lithotripsy was safe and more effective than Lithoclast lithotripsy in the aspect of immediate stone free rate. We believe that holmium:YAG laser is an excellent treatment modality for managing ureteral calculi.

Assessment of Novel Ureteral Occlusion Device and Comparison with Stone Cone in Prevention of Stone Fragment Migration during Lithotripsy

PURPOSE

To present the initial ex-vivo results of a new ureteral-occlusion device (Cook Urological, Spencer, IN) for preventing the retrograde migration of particles during ureteroscopy and its comparison with the Stone Cone (Microvasive-Boston Scientific Corp., Spencer, IN).

MATERIALS AND METHODS

We designed an ex-vivo model using a porcine kidney with an intact ureter. Standardized plastic beads were placed in the proximal ureter. Each device was deployed proximal to the beads during ureteroscopy, and the number of beads impeded by each device was recorded.

RESULTS

The new device was successful at preventing retrograde migration of beads > or = 1.5 mm. Furthermore, 1.0-mm beads were impeded by the center of the device, although they passed through the periphery. The Stone Cone blocked the retrograde migration of beads > or = 2.5 mm.

CONCLUSION

The new occlusion device was efficacious in an ex-vivo model. It appears to prevent the migration of smaller particles than are blocked by the Stone Cone.

Prevention of retrograde calculus migration with the Stone Cone

Retrograde calculus migration during ureteroscopic lithotripsy remains a problem in 5-40% of cases. We assessed the safety and efficacy of the Stone Cone device, in comparison with the standard flat wire basket. A total of 56 consecutive patients with ureteral calculi, suitable for ureteroscopic extraction and/or lithotripsy, where included in this prospective study. Patients were randomly allocated into two groups. In group A (30 patients), we used the Stone Cone, while in group B (26 patients) we used the standard flat wire basket. The Stone Cone was placed through a cystoscope under fluoroscopic guidance, or when necessary under direct ureteroscopic control. Whenever necessary, intracorporeal electrohydraulic lithotripsy took place in both groups. Statistical significance was assessed by the paired t-test. The mean operative time was 48.5 min in group A, and 42.4 min in group B. Intact calculus extraction was possible in 16.6% in group A, and in 7.6% in group B (P < 0.01). Retrograde stone migration was revealed in 23% in group B only (P < 0.001). Also, residual fragments > 3 mm were recorded in 30.7% in group B only (P < 0.001). None of the patients in group A required auxiliary procedures, in contrary to 23% in group B (P < 0.001). No major complications were recorded in group A, while in group B a case of major ureteral mucosal abrasion was recorded. The Stone Cone is safe and efficient in preventing retrograde stone migration and in minimizing residual fragments during ureteroscopic lithotripsy in comparison with the flat wire basket.

Treatment of Ureteral Calculi with Ballistic Lithotripsy

BACKGROUND AND PURPOSE

Ballistic lithotripsy is one of the new intracorporeal lithotripsy methods. In this study, the efficacy and complications of this method in the management of ureteral calculi were evaluated.

PATIENTS AND METHODS

From November 1999 to December 2001, 340 patients (mean age 39.8 years; range 1.5-82 years) with a total of 362 ureteral calculi (bilateral in 22 cases) were treated with an 8.5F rigid ureteroscope and the Swiss Lithoclast. Of the calculi, 115 (32%) were located in the upper ureter, 63 (17%) in the middle ureter, and 184 (51%) in the lower ureter. The mean stone size was 10.4 mm (range 5-22 mm).

RESULTS

Nearly all (344; 95%) of the calculi were accessible with the ureteroscope, and 321 calculi (88.7%) were fragmented completely, either with no residual fragments or with residual fragments <3 mm. In 3 cases (0.8%), there were residual fragments of about 4 mm after the procedure that passed spontaneously. Twenty calculi (5.5%) migrated to the kidney during the procedure and were subsequently treated with adjuvant SWL. Major complications occurred in 2 cases (0.54%): ureteral perforation and stenosis in 1 patient each. The 2-week stone-free rate was 89.5% (324/362).

CONCLUSION

Lithoclast ballistic lithotripsy is a safe and effective approach for the treatment of ureteral calculi regardless of composition.

The management of urinary calculi in pregnancy

When a pregnant patient presents with a urinary calculus, the customary investigations and management must change in order to take into account the well-being of the developing fetus. Transabdominal or endovaginal ultrasound should be the initial imaging modality used in order to establish the diagnosis. A plain abdominal X-ray, limited intravenous pyelography, or retrograde pyelography is used secondarily if a definitive diagnosis is lacking. The treatment of first choice for urolithiasis in pregnancy is conservative, because 70-80% of stones will pass spontaneously. If conservative management fails, or in cases of sepsis, obstruction of a solitary kidney, or bilateral ureteric obstruction, then surgical intervention is indicated. Traditional surgical management consists of draining the obstructed collecting system with a ureteral stent or percutaneous nephrostomy tube with definitive treatment of the stone in the post-partum period. Ureteroscopic lithotripsy and stone extraction is another option that has been used safely and reliably with increasing frequency in many centers. Despite recent reports of using extracorporeal shock-wave lithotripsy, this treatment is still considered contraindicated in pregnancy.

Ureteroscopy for proximal ureteral calculi: prevention of stone migration

BACKGROUND

The cephalad migration of proximal ureteral calculi accounts for a high percentage of ureteroscopic failures.

PATIENTS AND METHODS

A balloon on a wire is a single-channel 0.038-inch hollow guidewire with a low-profile balloon, which is inflatable to 12F. Forty-two consecutive patients with proximal ureteral calculi underwent ureteroscopy with the aid of this device.

RESULTS

Twenty-nine patients had successful placement of the balloon on a wire above the stone. Of those 29 patients, 26 became stone free with a single procedure.

CONCLUSION

The balloon on a wire is a useful tool to aid in the prevention of proximal ureteral stone migration during ureteroscopy and to minimize the number of secondary procedures. In addition, it appears to be cost-effective.

A randomized trial comparing lithoclast with an electrokinetic lithotripter in the management of ureteric stones

OBJECTIVE

To compare two in situ ballistic lithotripters, the lithoclast and the electrokinetic lithotripter (EKL), both of which can be used through the newer small-bore ureteroscopes, for their ease of use, robustness, fragmentation time, adequacy of fragmentation and stone-free rate.

PATIENTS AND METHODS

Forty-six consecutive patients with ureteric stones refractory to treatment by extracorporeal shock wave lithotripsy were randomized to undergo fragmentation using the lithoclast (23 patients) or the EKL (23 patients). One patient was excluded from analysis in the EKL group. The adequacy of fragmentation was recorded, with the degree and significance of proximal migration for each device. After treatment patients were assessed by plain X-ray and the stone-free rate was determined.

RESULTS

The mean (median) initial stone burdens in the lithoclast and EKL groups were 69 (50) mm2 and 72 (52) mm2, respectively. The respective mean (median) procedure duration and fragmentation time were 54 (50) min and 90 (49) s in the lithoclast group, and 50 (42.5) min and 87 (52.5) s in the EKL group; the differences were not statistically significant. In four (14%) patients of each group there was significant proximal migration of the stones. The stones were completely fragmented in 17 of 23 (74%) patients in the lithoclast group and 19 of 22 (86%) in the EKL group. There was no fragmentation in one patient in each group. In the lithoclast and EKL groups, 20 of 23 (87%) and 17 of 22 (77%) were rendered stone-free, respectively (P > 0.5). The equipment failed on two occasions in each group.

CONCLUSION

In this randomized trial there was no significant difference in the stone-free rate, procedure duration, fragmentation time, proximal stone migration rate and equipment failure between these in situ ballistic lithotripters.

Holmium: YAG lasertripsy for ureteric calculi: an experience of 300 procedures

OBJECTIVE

To assess the success of holmium:YAG lasertripsy in the management of ureteric calculi and to audit the complications of the procedure, with special reference to strictures in the ureter.

PATIENTS AND METHODS

A total of 300 ureteroscopic laser procedures were carried out on 265 patients (204 male and 61 female, median age 51 years, range 2-95) with ureteric calculi. At ureteroscopy, the calculi were present in the upper ureter in 44%, mid-ureter in 37% and lower ureter in 19% of patients; most calculi were > 5 mm. A 7.5 F Wolf semi-rigid ureteroscope was used and the holmium:YAG laser energy delivered using the Sharplan ML210 device at 0.8-1.0 J/pulse. The patients were followed up at approximately 6 weeks with limited intravenous urography or ultrasonography to assess clearance and the incidence of strictures.

RESULTS

Stones were completely cleared in 90% of the patients, with the best results in the lower and mid-ureter (97% and 96%, respectively) followed by the upper ureter (89%). Alternative procedures were required in only 17 (7%) patients; extracorporeal shock-wave lithotripsy in 13, percutaneous nephrolithotomy in two and open pyelolithotomy in two patients. Complications with ureteric perforation in 11 patients, including laparotomy for peritonitis in one, serious sepsis in two and strictures in 10 patients. Strictures were more common in association with impacted calculi in the upper ureter early in the series.

CONCLUSIONS

Holmium:YAG lasertripsy is a highly effective treatment for ureteric calculi, with strictures related to the treatment of difficult upper ureteric calculi.

Intracorporeal or extracorporeal lithotripsy for distal ureteral calculi? Effect of stone size and multiplicity on success rates

Over a period of 57 months, 404 patients with distal ureteral calculi were treated by in situ SWL on a Storz Modulith SL 20 lithotripter and 163 by ureteroscopy (URS) and Swiss Lithoclast stone fragmentation. The case notes on these patients were reviewed for comparison of the initial stone number and individual length and for the calculation of the stone-free, treatment, retreatment, secondary procedure, and complication rates. Complete data were available on 447 patients. The median stone length was 7.0 (range 4-25) mm in the SWL group and 8.0 (range 5-13) mm in the URS group. The single-treatment stone-free rates for the SWL and URS groups were 74.8% and 89.7%, respectively, for single stones and 50.0% and 88.9%, respectively, for multiple (>1) stones. The mean treatment rates for the SWL and URS groups were 1.97 and 1.03, respectively, for single stones and 2.83 and 1.00, respectively, for multiple stones. The mean treatment rate for single stones subjected to SWL increased with increasing stone length (1.57 for stones <8 mm and 2.38 for stones >8 mm), whereas this was not the case for patients submitted to URS (1.20 and 1.27, respectively). The re-treatment rate for each group showed a reciprocal trend. Of the SWL group, 25.9% of the patients eventually required URS to render them stone-free. Nearly all (96%) of the patients undergoing SWL were treated as outpatients. The mean hospitalization in the URS group was 1.1 days. Three patients who underwent URS sustained a ureteral perforation, which was managed successfully by double-J stent insertion. The ideal primary treatment for small (<8 mm) distal ureteral calculi is in situ SWL, with URS plus Lithoclast fragmentation being reserved for failed SWL, single stones >8 mm in length, and multiple stones.

Uretero-lithotripsy with the Swiss Lithoclast

Technological developments in ureteroscopy and extracorporeal shock wave lithotripsy (ESWL) have changed the treatment of ureteral stones over the last decade. “In situ” ESWL is now the treatment of choice in the management of ureteral calculi. Ureterolithotripsy should be preferred in certain cases, however, especially when the stone cannot be perfectly sighted or when the urinary tract needs to be drained due to obstruction and/or sepsis, with a saving of one ESWL session in 50% of patients. Current options that can be applied with lithotripsy are: electrohydraulic, laser, ultrasound and ballistic tripsy. The authors describe their experience with the Lithoclast in 82 patients. This technique has proved to be simple, safe, effective and particularly economic.