Overview of High-Risk Medical Device Innovation in Gastroenterology from 2000 to 2014: Enhancing the Pipeline.

Medical devices are a critical component in the diagnosis and treatment of diseases of the alimentary tract. The United States Food and Drug Administration database was mined for high-risk medical device development via the pre-market approval (PMA) pathway from 2000 to 2014. In total, there were only nine GI (gastrointestinal) devices approved during this period. Furthermore, only one GI device was granted expedited review. The clinical studies leading to approval were mostly limited to non-blinded, non-randomized studies. Only a minority of pivotal studies defined and met their primary endpoints (27 %). Eight out of nine devices were required to undergo post-marketing studies. Ultimately, cardiology led with 157 total approvals in the time period studied. GI ranked 12 out of 18 across various medical and surgical specialties and accounted for <2 % of total PMA approvals. Future efforts should focus on spurring more high-risk device innovation in the field.

In Vitro Assessment of Three Clinical Lithotripters Employing Different Shock Wave Generators.

OBJECTIVE: To test the hypothesis that shock wave lithotripsy machines vary in their ability to fragment standardized artificial urinary calculi. MATERIALS AND METHODS: An in vitro test configuration was used to fragment synthetic U-30 Gypsum (U.S. Gypsum, Chicago, IL) stones (mean length 7.1 ± 0.2 mm, mean diameter 6.5 ± 0.07 mm, mean mass 299 ± 16 mg) using the Sonolith i-sys (EDAP TMS, Vaulx-en-Velin, France), Modulith SLX F2 (Storz Medical AG, Tägerwilen, Switzerland), and Piezolith 3000 (Richard Wolf GmbH, Knittlingen, Germany) lithotripters. Gypsum stones were placed at the nominal focus and treated with 250, 500, or 1000 shocks. The residual mass following passage through a 2-mm wire mesh was measured and compared using ANOVA and the Tukey-Kramer HSD test. RESULTS: There was no statistically significant difference between the Modulith SLX F2 and Piezolith 3000 lithotripters for 250 and 1000 shock treatments (p = 0.34 and 0.31, respectively). The Piezolith 3000 demonstrated the most favorable stone mass reduction for 500 shock treatments (187.4 ± 45.2 mg). The Sonolith i-sys was found to be significantly less effective than the other lithotripters for all shockwave conditions. Furthermore, performance of the Sonolith i-sys decreased beyond a threshold generator electrode age of 6000 shocks. CONCLUSIONS: This in vitro study found considerable variability in the ability of lithotripters to fragment synthetic urinary calculi. Synthetic stones were employed to provide a repeatable means of assessing variability in fragmentation efficiency of lithotripters. The Modulith SLX F2 and Piezolith 3000 are broadly equal and resulted in greater fragmentation efficiencies than the Sonolith i-sys. The performance of the Sonolith i-sys deteriorates at 6000 shocks, before the specified lifetime of 20,000 shocks.

Disposable devices for RIRS: where do we stand in 2013? What do we need in the future?

PURPOSE: Disposable devices for retrograde intrarenal surgery (RIRS) form a significant part of the urologist's armamentarium for the endoscopic management of urologic diseases. Herein, we provide an overview of the literature regarding the advances and controversies of these devices. METHODS: A PubMed search was used to identify the literature discussing the subject of disposable devices for RIRS. Articles published between 2012 and 2013 were considered. RESULTS: Ureteral access implements including access sheaths, wires, and dilators are an area of both improvement and controversy regarding their proper use. The safety, effectiveness, and limitations of lithotrites continue to be refined. Stone retrieval devices are undergoing persistent miniaturization, and their use may prove to be cost effective. The debate over perioperative stenting remains, while symptom management is explored. A cost-effective option for disposable flexible ureteroscopy shows promise. CONCLUSIONS: While rapid advances in technology and knowledge continue, continual improvements are necessary. Disposable equipment needs persistent refinement and possible miniaturization. More efficient fragment retrieval devices are needed. Durability of laser fibers and safety within ureteroscopes needs to be improved. Reducing stent morbidity remains an ongoing challenge. Lastly, costs need to be reduced by the further development of disposable flexible ureteroscopes and in the recyclability of disposable devices to improve availability worldwide.

Micro-ureteroscopy: Initial experience in the endoscopic treatment of pelvic ureteral lithiasis.

OBJECTIVES: To present to report the first case of ureteral lithiasis resolved using a new endoscopic approach, which we call microureteroscopy (m-URS) and attempts to reduce the ureteral damage caused by conventional instrumentation. MATERIAL AND METHODS: We selected a 53-year-old patient with a 16-mm calculus in the right distal ureter. For endoscopic access, we used a 4.8 Fr sheath from the microperc set and fragmented the stone with a 230-micron laser fiber. RESULTS: Complete fragmentation of the stone was achieved. We placed a JJ catheter due to significant ureteral edema. The surgical time and postsurgical stay were 156minutes and 24hours, respectively. There were no complications, the requirements for analgesia were minimal, and the patient was free of residual stones. CONCLUSIONS: The m-URS technique is feasible, simple and effective for the treatment of pelvic ureteral lithiasis in women and optimizes minimal invasion, with results that can be comparable to conventional endoscopic techniques in terms of ease of access and quality of endoscopic vision without affecting the resolution capacity. Larger studies and greater technological development is needed to define the definitive role of this procedure. Currently, its major limitations lie in the treatment of proximal ureter lithiasis and in the treatment of men. This technique could also be a viable alternative for pediatric patients.

Clinical efficacy, safety, and costs of percutaneous occlusive balloon catheter-assisted ureteroscopic lithotripsy for large impacted proximal ureteral calculi: a prospective, randomized study.

PURPOSE: To evaluate the clinical efficacy, safety, and costs of percutaneous occlusive balloon catheter-assisted ureteroscopic lithotripsy (POBC-URSL) for large impacted proximal ureteral calculi. PATIENTS AND METHODS: 156 patients with impacted proximal ureteral stones ≥1.5 cm in size were randomized to ureteroscopic lithotripsy (URSL), POBC-URSL, and percutaneous nephrolithotomy (PNL) group between May 2010 and May 2013. For URSL, the calculi were disintegrated with the assistance of anti-retropulsion devices. POBC-URSL was performed with the assistance of an 8F percutaneous occlusive balloon catheter. PNL was finished with the combination of an ultrasonic and a pneumatic lithotripter. A flexible ureteroscope and a 200 µm laser fiber were used to achieve stone-free status to a large extent for each group. Variables studied were mean operative time, auxiliary procedure, postoperative hospital stay, operation-related complications, stone clearance rate, and treatment costs. RESULTS: The mean lithotripsy time for POBC-URSL was shorter than URSL, but longer than PNL (42.6±8.9 minutes vs 66.7±15.3 minutes vs 28.1±6.3 minutes, p=0.014). The auxiliary procedure rate and postoperative fever rate for POBC-URSL were significantly lower than URSL and comparable to PNL (p<0.01, p=0.034). POBC-URSL was superior to URSL with regard to the stone clearance rate at 3 days postoperatively, and as good as PNL (98.1% vs 75.0% vs 96.2%, p<0.01). The postoperative hospital stay and hematuria rate were lower in POBC-URSL group than PNL group and similar to URSL group (p=0.016, p<0.01). The treatment costs were lowest in POBC-URSL group ($1205.0±$113.9 vs $1731.7±$208.1 vs $2446.4±$166.4, p=0.004). CONCLUSIONS: For large impacted proximal ureteral calculi, POBC-URSL was associated with a higher stone clearance rate, fewer complications and costs. POBC-URSL combined the advantages of URSL and PNL.

Antiretropulsion devices.

PURPOSE OF REVIEW: Stone migration during the treatment of ureteral stones can prove frustrating and increases both healthcare cost and patient morbidity. Antiretropulsion devices have been engineered to prevent stone migration. RECENT FINDINGS: Improvements in antiretropulsion devices allow for efficient prevention of stone migration during ureteroscopic lithotripsy with minimal adverse effects or complications. Multiple devices are now available each with advantages and disadvantages. New devices are currently engineered to prevent stone migration and maintain ureteral access. Antiretropulsion devices appear to be cost-effective to prevent stone migration during intracorporeal lithotripsy. SUMMARY: Antiretropulsion devices have been safely and effectively used during ureteroscopic procedures. These tools increase stone-free rates, decrease morbidity and new studies have demonstrated their cost-effectiveness.

Lithotripsy for salivary stones with prospective US assessment on our first 25 consecutive patients.

OBJECTIVES: To evaluate the predictive value of sonographic fragmentation in the successful treatment of sialolithiasis. The main objective was to streamline the management by treating the patients with three sessions of ultrasonic lithotripsy, and to compare the success rate and complications with data from the literature. A second objective was to analyse the predictive value of data from the post procedure and follow-up sonography related to therapeutic success with regard to size, site and location of stones. MATERIAL AND METHODS: Prospective follow-up of 25 patients (mean age of 43 ± 17.2 years old 11-68; 13 women, 10 men) over a period of 31 months (October 2009-April 2012) with one or more salivary calculi (19 parotid, submandibular 6) treated with extracorporeal lithotripsy (electromagnetic MINILITH SL 1, Storz Medical, Switzerland). No anaesthesia or analgesia was used. Each session of lithotripsy lasted on average 30 min. Minor complications were collected on an anonymised sheet. RESULTS: Complete success (absence of clinical symptoms 3 months after the end of treatment (or the last session) and residual stones <2 mm) was observed in 36% of patients, partial success (persistence of symptoms least 3 months (lower intensity and lower frequency) or size of residual stones>2 mm) in 48% and failure (persistence of same or increased symptoms at 3 months or no change in size of the calculi) in 17% of patients. Sonographic fragmentation of the stone (p = 0.004), total energy delivered (p = 0.008) and the total number of shock waves (n = 0.045) are predictive factors of complete success. Size, salivary topography, ductal topography, mobilization of the stones, occurrence of minor side effects and total duration of treatment had no predictive value of complete success (p > 0.05). There was no significant difference between the first 5 and the last 20 patients (p = 0.367). In agreement with the literature data, the efficacy of treatment was greater for parotid than submandibular calculi. CONCLUSION: Extracorporeal lithotripsy is an alternative to conventional surgery with no major complications. Sonographic fragmentation of calculi, total energy and total number of shock waves are predictive factors of successful treatment.

Assessment of a modified acoustic lens for electromagnetic shock wave lithotripters in a swine model.

PURPOSE: The acoustic lens of the Modularis electromagnetic shock wave lithotripter (Siemens, Malvern, Pennsylvania) was modified to produce a pressure waveform and focal zone more closely resembling that of the original HM3 device (Dornier Medtech, Wessling, Germany). We assessed the newly designed acoustic lens in vivo in an animal model. MATERIALS AND METHODS: Stone fragmentation and tissue injury produced by the original and modified lenses of the Modularis lithotripter were evaluated in a swine model under equivalent acoustic pulse energy (about 45 mJ) at 1 Hz pulse repetition frequency. Stone fragmentation was determined by the weight percent of stone fragments less than 2 mm. To assess tissue injury, shock wave treated kidneys were perfused, dehydrated, cast in paraffin wax and sectioned. Digital images were captured every 120 µm and processed to determine functional renal volume damage. RESULTS: After 500 shocks, the mean ± SD stone fragmentation efficiency produced by the original and modified lenses was 48% ± 12% and 52% ± 17%, respectively (p = 0.60). However, after 2,000 shocks, the modified lens showed significantly improved stone fragmentation compared to the original lens (mean 86% ± 10% vs 72% ± 12%, p = 0.02). Tissue injury caused by the original and modified lenses was minimal at a mean of 0.57% ± 0.44% and 0.25% ± 0.25%, respectively (p = 0.27). CONCLUSIONS: With lens modification the Modularis lithotripter demonstrates significantly improved stone fragmentation with minimal tissue injury at a clinically relevant acoustic pulse energy. This new lens design could potentially be retrofitted to existing lithotripters, improving the effectiveness of electromagnetic lithotripters.

Evaluation of the LithoGold LG-380 lithotripter: in vitro acoustic characterization and assessment of renal injury in the pig model.

PURPOSE: Conduct a laboratory evaluation of a novel low-pressure, broad focal zone electrohydraulic lithotripter (TRT LG-380). METHODS: Mapping of the acoustic field of the LG-380, along with a Dornier HM3, a Storz Modulith SLX, and a XiXin CS2012 (XX-ES) lithotripter was performed using a fiberoptic hydrophone. A pig model was used to assess renal response to 3000 shockwaves (SW) administered by a multistep power ramping protocol at 60 SW/min, and when animals were treated at the maximum power setting at 120 SW/min. Injury to the kidney was assessed by quantitation of lesion size and routine measures of renal function. RESULTS: SW amplitudes for the LG-380 ranged from (P(+)/P(-)) 7/-1.8 MPa at PL-1 to 21/-4 MPa at PL-11 while focal width measured ~20 mm, wider than the HM3 (8 mm), SLX (2.6 mm), or XX-ES (18 mm). For the LG-380, there was gradual narrowing of the focal width to ~10 mm after 5000 SWs, but this had negligible effect on breakage of model stones, because stones positioned at the periphery of the focal volume (10 mm off-axis) broke nearly as well as stones at the target point. Kidney injury measured less than 0.1% FRV (functional renal volume) for pigs treated using a gradual power ramping protocol at 60 SW/min and when SWs were delivered at maximum power at 120 SW/min. CONCLUSIONS: The LG-380 exhibits the acoustic characteristics of a low-pressure, wide focal zone lithotripter and has the broadest focal width of any lithotripter yet reported. Although there was a gradual narrowing of focal width as the electrode aged, the efficiency of stone breakage was not affected. Because injury to the kidney was minimal when treatment followed either the recommended slow SW-rate multistep ramping protocol or when all SWs were delivered at fast SW-rate using maximum power, this appears to be a relatively safe lithotripter.

Cost-effectiveness of anti-retropulsion devices for ureteroscopic lithotripsy.

PURPOSE: We evaluated the cost-effectiveness of anti-retropulsion devices used during ureteroscopic lithotripsy. MATERIALS AND METHODS: A decision analysis model was constructed to compare the cost-effectiveness of ureteroscopic lithotripsy with vs without an anti-retropulsion device. The risk of stone retropulsion was determined from published data in the English language literature. Expected value calculations were used to determine whether the additional cost of a device would be cost-effective to prevent secondary procedures used to treat retropulsed stones. Device cost was determined using the average cost of all commercially available devices. RESULTS: It became cost-effective to use an anti-retropulsion device at or above a 6.3% retropulsion rate. The weighted probability of retropulsion with vs without an anti-retropulsion device was 98.1% vs 83.7%. The estimated costs of secondary procedures needed to treat retropulsed stones were $5,290 for shock wave lithotripsy and $6,390 for ureteroscopy. Average device cost was $278. Thus, the average additional cost of ureteroscopic lithotripsy with vs without an anti-migration device would be $384 vs $952. CONCLUSIONS: It is cost-effective to use an anti-retropulsion device at a retropulsion rate of greater than 6.3%.

In-vitro assessment of a new portable ballistic lithotripter with percutaneous and ureteroscopic models.

BACKGROUND AND PURPOSE: The EMS Swiss LithoBreaker is a new, portable, electrokinetic lithotripter. We compared its tip velocity and displacement characteristics with a handheld, pneumatic lithotripter LMA StoneBreaker.™ We also evaluated fragmentation efficiency using in vitro models of percutaneous and ureteroscopic stone fragmentation. MATERIALS AND METHODS: Displacement and velocity profiles were measured for 1-mm and 2-mm probes using a laser beam aimed at a photo detector. For the percutaneous model, 2-mm probes fragmented 10-mm spherical BegoStone phantoms until the fragments passed through a 4-mm mesh sieve. The ureteroscopic model used 1-mm probes and compared the pneumatic and electrokinetic devices to a 200-µm holmium laser fiber. Cylindrical (4-mm diameter, 4-mm length) BegoStone phantoms were placed into silicone tubing to simulate the ureter; fragmented stones passed through a narrowing in the tubing. RESULTS: For both 1-mm and 2-mm probes, the electrokinetic device had significantly higher tip displacement and slower tip velocity, P<0.01. In the percutaneous model, the electrokinetic device needed an average of 484 impulses over 430 seconds to fragment one BegoStone, while the pneumatic device needed 29 impulses over 122 seconds to fragment one stone. Both clearance times and number of impulses needed for percutaneous stone clearance were significantly different at P<0.01. Ureteroscopically, the mean clearance time was 97 seconds for the electrokinetic lithotripter, 145 seconds for the pneumatic lithotripter, and 304 seconds for the laser. Comparing the pneumatic device with the electrokinetic device ureteroscopically, there was no significant difference in clearance time, P=0.55. Both the pneumatic and electrokinetic lithotripters, however, demonstrated decreased clearance times compared with the laser, P=0.027. CONCLUSIONS: The portable electrokinetic lithotripter may be better suited for ureteroscopy instead of percutaneous nephrolithotomy. It appears to be comparable to the portable pneumatic device in the ureter. Further clinical studies are needed to confirm these findings in vivo.

In vitro assessment of a novel spearheaded pneumatic intracorporeal lithotriptor.

BACKGROUND AND PURPOSE: Intracorporeal lithotripsy is an important modality used for stone pulverization. To improve the pulverization properties of intracorporeal lithotriptors, a novel intracorporeal "spearheaded lithotriptor" was designed by our institute. It was compared in vitro with the conventional lithotriptor. MATERIALS AND METHODS: The pulverization and propulsion dynamics were evaluated at various pressure settings on an in vitro bench arrangement with phantom stones. Lateral displacement during pulverization was also compared. RESULTS: The spearheaded lithotriptor had a better first hit (P<0.001) and follow-up hit dynamics (P<0.01). Stone propulsion and lateral displacement were low for the spearheaded lithotriptor at all pressure settings (P<0.05). CONCLUSION: The spearheaded lithotriptor improved stone pulverization without increasing the risk of stone migration. Further clinical evaluation of this novel probe is necessary.

[Medical and Economic Aspects of Extracorporeal Shock Wave Lithotripsy]. / Aktuelle medizinische und ökonomische Aspekteder extrakorporalen Stoßwellenlithotripsie.

Extracorporeal shock wave lithotripsy (ESWL) is the method of choice for most renal and ureteral calculi. However, endoscopic procedures such as ureteroscopy or percutaneous nephrolithotomy are being more and more performed as primary treatment alternatives in clinical routine. This development may result from the sometimes unsatisfying results of ESWL. While this is often explained by a lower efficacy of last-generation machines, an often unrecognized explanation is the impact of a less well trained urologist. To achieve best results it is mandatory that fundamental knowledge about shock wave physics and disintegration mechanisms are available. In Germany, the reimbursement system between outpatient and inpatient departments is totally separate. This leads to difficulties in clinical practice. We believe that patients at risk for complications, such as ureteral stones, urinary tract infections or high age, benefit from inpatient treatment, while uncomplicated renal stones can safely be treated on an outpatient basis. Regular application and training of ESWL will aid an optimization of its results and acceptance.

Use of ureteroscopy before and after expansion of lithotripter ownership in Michigan.

OBJECTIVE: To determine whether ureteroscopy (URS) rates decreased following the expansion of lithotripter ownership in Michigan. Historically, Michigan has had limited urologist investment in lithotripters owing to strict Certificate of Need legislation. However, 2 of the nation's largest lithotripsy providers formed Michigan subsidiaries in 2005 and 2006, thereby altering the ownership landscape. Urologists who acquired partnership shares were incentivized to perform shock wave lithotripsy preferentially over URS. Because of ownership expansion, the rates of URS might have decreased. METHODS: From the Michigan files of the State Ambulatory Surgery Database, we abstracted the discharges for URS performed at hospital-based outpatient departments. We measured the differences between the patients who underwent URS in the year before (2004) and the year after (2007) ownership expansion. We then calculated the annual rates of URS in Michigan and evaluated for changes over time. RESULTS: A total of 5857 and 6294 URSs were performed in 2004 and 2007, respectively. Significant differences in age (P < .001), race (P < .001), primary payer (P < .001), and comorbidity status (P < .001) were observed between the patients who underwent URS before and after ownership expansion. However, the rates of URS in Michigan remained relatively flat despite the increased urologist ownership of lithotripters (P = .129 for the temporal trend). CONCLUSION: The introduction of physician ownership of lithotripter units in Michigan was not associated with decreased rates of URS but might have influenced treatment selection among certain patient groups.

A randomized prospective controlled study for assessment of different ureteral occlusion devices in prevention of stone migration during pneumatic lithotripsy.

OBJECTIVE: To compare the safety and efficacy of two different ureteral occlusion devices (stone cone and entrapment net) in preventing retrograde stone migration during ureteroscopic pneumatic lithotripsy. Proximal migration of stone fragments during ureteroscopic lithotripsy is a common problem, especially when the pneumatic lithotripter is used for stone fragmentation. PATIENTS AND METHODS: A total of 195 patients with proximal ureteric stones were prospectively randomized into one of three groups in this study, with 65 patients in each group. In group I, the Stone Cone was used as a ureteral occlusive device; in group II, the N-Trap was used; and in group III (control group), the patients underwent pneumatic lithotripsy without any ureteral occlusive device. RESULTS: The ureteroscopic procedure was completed successfully in 180 patients; 63 patients in group I, 59 patients in group II, and 58 patients in group III. Patients in group I showed significantly lower incidence of stone migration compared with the other 2 groups (P <.05). Both ureteral occlusive devices significantly lowered the incidence of residual fragments (>3 mm), ureteral trauma, operative time, and the need for ureteral stenting compared with control group. The stone-free rate at 3 weeks was 95.24%, 83.05%, and 72.41% in groups I, II, and III, respectively. The patients in group I had a statistically significant stone-free rate compared with the other two groups (P <.05). Auxiliary procedures were required in 3 (4.76%), 10 (16.94%), and 16 cases (27.58%) in groups I, II, and III, respectively. CONCLUSION: The use of Stone Cone or N-Trap is valuable during ureteroscopic pneumatic lithotripsy for treatment of proximal ureteral stones. Both devices significantly diminish residual fragments, the incidence of ureteral wall trauma, and the need for the auxiliary procedure. However, the stone cone was more effective in preventing proximal stone migration and the subsequent stone-free rate.

How effective is extracorporeal shock wave lithotripsy of ureteral stones with Dornier Lithotripter S EMSE 220F-XXP? A prospective and preliminary assessment.

AIM: To report our preliminary series with the Doli S EMSE 220F-XXP, the upgraded version of the previous Dornier Lithotripter S EMSE 220, for treatment of ureteral stones. METHODS: Since July 2006, a total of 200 patients with ureteral stones were submitted to shock wave lithotripsy (SWL) with Doli S EMSE 220F-XXP. Mean stone size was 9.3 mm (range 6-18 mm). Ureteral stone location was proximal in 75, middle in 34, and distal in 91. Follow-up was carried out at 6 weeks after the treatment, by means of kidney-ureter-bladder (KUB) film and ultrasound, or helical computed tomography (CT). RESULTS: The overall stone-free rate was 89.5%, and the effectiveness quotient was 80. Stratifying by stone site, the stone-free rate was 93.3, 67.6, and 94.5% for proximal, middle, and distal location, respectively. Mean number of sessions per patient was 1.14. Analgesia with intravenous ketorolac or tramadol was required in 42.5% of cases. No significant side-effects were recorded. CONCLUSIONS: The new Doli S EMSE 220F-XXP provides similar characteristics to the Doli S EMSE 220 in terms of safety and lack of major complications, when dealing with ureteral stones; the improvement in stone disintegration is particularly evident for distal location, for which the number of pulses and the intensity of treatment can be greatly increased and the upgraded power of the device can be widely applied.

Percutaneous nephrolithotomy for proximal ureteral calculi with severe hydronephrosis: assessment of different lithotriptors.

PURPOSE: We compared the efficacy and safety of percutaneous nephrolithotomy (PCNL) with different intracorporeal lithotriptors for proximal ureteral stones in patients with severe hydronephrosis. PATIENTS AND METHODS: We retrospectively analyzed the records of 192 patients with proximal ureteral calculi and severe hydronephrosis who underwent PCNL between February 2003 and December 2007. Calculi were fragmented with a pneumatic lithotriptor in 44 patients (group 1), Swiss Lithoclast Master in 54 (group 2), low-power holmium:yttrium-aluminum-garnet (YAG) laser in 56 (group 3) and high-power holmium:YAG laser in 38 (group 4). Patients were assessed about 12 months postoperatively with intravenous urography and ultrasonography for late complications. Stone size, operative time, stone-free rate, and follow-up were analyzed in each group. RESULTS: Mean stone size for different groups were 16.2 +/- 2.8 mm, 16.6 +/- 2.1 mm, 16.0 +/- 2.7 mm, and 16.4 +/- 1.1 mm, respectively. Average operative time for different groups were 118 +/- 17 minutes, 81 +/- 10 minutes, 85 +/- 14 minutes, 110 +/- 16 minutes, respectively. Group 2 and group 3 showed superior outcomes of shorter operative time (P = 0.000). The overall stone-free rate was 86.5%. As stratified by lithotriptors, the stone-free rate was 81.8% in group 1, 92.9% in group 2, 88.9% in group 3, and 78.9% in group 4 (P = 0.190). No significant difference was found among the groups in terms of blood loss and postoperative hospital stay. Repeated PCNL or shockwave lithotripsy was necessary as an auxiliary procedure in 26 patients. The overall complication rate was 18.2%; most complications were minor and insignificant. During the follow-up, ureteral stricture developed in 10 patients and new renal stones developed in 4 patients. CONCLUSIONS: PCNL combined with Swiss Lithoclast Master or low-power holmium:YAG laser is the preferred endourologic modality for the management of proximal ureteral calculi in patients with severe hydronephrosis.

Assessment of renal injury with a clinical dual head lithotriptor delivering 240 shock waves per minute.

PURPOSE: Lithotriptors with 2 treatment heads deliver shock waves along separate paths. Firing 1 head and then the other in alternating mode has been suggested as a strategy to treat stones twice as rapidly as with conventional shock wave lithotripsy. Because the shock wave rate is known to have a role in shock wave lithotripsy induced injury, and given that treatment using 2 separate shock wave sources exposes more renal tissue to shock wave energy than treatment with a conventional lithotriptor, we assessed renal trauma in pigs following treatment at rapid rate (240 shock waves per minute and 120 shock waves per minute per head) using a Duet lithotriptor (Direx Medical Systems, Petach Tikva, Israel) fired in alternating mode. MATERIALS AND METHODS: Eight adult female pigs (Hardin Farms, Danville, Indiana) each were treated with sham shock wave lithotripsy or 2,400 shock waves delivered in alternating mode (1,200 shock waves per head, 120 shock waves per minute per head and 240 shock waves per minute overall at a power level of 10) to the lower renal pole. Renal functional parameters, including glomerular filtration rate and effective renal plasma flow, were determined before and 1 hour after shock wave lithotripsy. The kidneys were perfusion fixed in situ and the hemorrhagic lesion was quantified as a percent of functional renal volume. RESULTS: Shock wave treatment resulted in no significant change in renal function and the response was similar to the functional response seen in sham shock wave treated animals. In 6 pigs treated with alternating mode the renal lesion was small at a mean +/- SEM of 0.22% +/- 0.09% of functional renal volume. CONCLUSIONS: Kidney tissue and function were minimally affected by a clinical dose of shock waves delivered in alternating mode (120 shock waves per minute per head and 240 shock waves per minute overall) with a Duet lithotriptor. These observations decrease concern that dual head lithotripsy at a rapid rate is inherently dangerous.

Use of LMA Stonebreaker as an intracorporeal lithotrite in the management of ureteral calculi.

BACKGROUND AND PURPOSE: LMA Stonebreaker is a new type of ballistic intracorporeal lithotrite that does not need external electric power or access to compressed air. It is small and portable. This study aims to evaluate the efficacy, safety, and cost-effectiveness of this lithotrite in the management of ureteral calculi. MATERIALS AND METHODS: A total of 110 patients with ureteral calculi necessitating intracorporeal lithotripsy were prospectively included in the study. The size of the stone, position of the stone, number of shocks needed to fragment the stone to effect complete clearance, and degree of retropulsion were documented in each case, and any evidence of urothelial trauma was noted. RESULTS: All stones were fragmented, and all patients were rendered stone free. The mean number of shocks needed to fragment the stones was eight. The incidence of retropulsion was 6.36%. There was no evidence of urothelial trauma noted in any patient. CONCLUSION: LMA Stonebreaker is a safe, effective, cost-effective, robust, and portable device for intracorporeal lithotripsy.