Initial clinical evaluation of a new pneumatic intracorporeal lithotripter

OBJECTIVE: To test the clinical efficacy of the StoneBreaker (LMA Urology, Gland, Switzerland), a novel device which is much more compact and ergonomic than other current intracorporeal pneumatic lithotripters, and more powerful, generating contact pressures of up to 2.9 MPa, thereby enabling better pneumatic fragmentation and removal of stones during percutaneous nephrostolithotomy (PCNL), ureteroscopic stone fragmentation (USF) and vesical stone lithotripsy (VL). PATIENTS AND METHODS: We prospectively evaluated 102 patients, comprising 49 PCNLs, 48 USFs and 5 VLs, treated using the StoneBreaker. The stone size, position, number of shocks required to fragment the stone to effect complete clearance, and degree of retropulsion were documented in each case; any evidence of urothelial trauma was noted. RESULTS: All stones were satisfactorily fragmented and all patients rendered stone-free. Very few shocks were required, and documented retropulsion was minor. There was no evidence of consequential urothelial trauma at the end of any procedure. CONCLUSION: The StoneBreaker appears to be a safe, effective, robust and compact device for intracorporeal lithotripsy.     

钬激光碎石术与气压弹道碎石术治疗胆道术后残余结石临床比较

目的比较钬激光碎石术与气压弹道碎石术治疗胆道术后残余结石的临床疗效。方法使用钬激光碎石治疗85例胆道术后残余结石患者;气压弹道碎石术治疗85例胆道术后残余结石患者。结果85例使用钬激光碎石治疗的患者一次手术结石粉碎率为96.4%,平均手术时间为25min。而气压弹道碎石组中上述各项指标分别为78.8%;平均手术时间为49min,均与钬激光碎石组有明显差异。结论钬激光碎石效明显优于气压弹道碎石,是治疗胆道术后残余结石一种安全、有效的碎石方法。     

Comparison of pneumatic and Holmium laser ureteroscopic lithotripsy for upper third ureteral stones

ObjectiveTo evaluate the outcomes of ureteroscopic lithotripsy with pneumatic lithotripter and Holium:Yttrium-Aluminum-Garnet (Ho:YAG) laser in the management of upper third ureteral stones.Materials and methodsPatients who underwent ureteroscopic lithotripsy with pneumatic lithotripter or Ho:YAG laser for upper third ureteral stones were retrospectively reviewed. Patients with urinary tract infection, radiolucent stones, loss of follow-up, concurrent middle or lower third ureteral stones or acute renal failure were excluded. Patient age, stone size and burden (based on KUB or computerized tomography), stone upward migration, double J stent insertion rate, stone free rate and secondary intervention rate for residual stones were compared in both groups.ResultsThere were 158 patients with 178 upper third ureteral stones (135 in pneumatic lithotripsy group and 43 in Ho:YAG laser lithotripsy group) meeting the study criteria. Patients' age, gender, stone laterality, stone size and burden were similar in both groups. The Ho:YAG laser lithotripsy group had better stone free rate, less double J stent insertion rate and less secondary intervention rate as compared with pneumatic lithotripsy (53.4% vs. 40.1%; 72.1% vs. 91.9%; 25% vs. 48.5% respectively, all p < 0.05). In patients with stones larger than 10 mm, Ho:YAG laser lithotripsy had significantly lower upward migration rate, lower double J stent insertion rate, higher stone free rate and less secondary intervention rate.ConclusionsHo:YAG laser lithotripsy is superior to pneumatic lithotripsy in the management of upper third ureteral stones in terms of double J stent insertion rate, stone free rate and secondary intervention rate for stones of all sizes. For stones larger than 10 mm, laser lithotripsy results in less stone upward migration.     

Clinical experience with a new ultrasonic and LithoClast combination for percutaneous litholapaxy

OBJECTIVE: To assess a new lithotripter for intracorporal lithotripsy, which combines the mechanically driven pneumatic LithoClast (Electro-Medical Systems, Nyon, Switzerland) and a new ultrasonic device (Electro-Medical Systems), for use in percutaneous nephrolitholapaxy (PNL). PATIENTS AND METHODS: The new lithotripter consists of a LithoClast Master with 12 Hz repetition rate and a new ultrasonic device. The 1.0 mm LithoClast probe is advanced off-centre through the hollow 3.3 mm ultrasonic probe and protrudes about 1 mm. A new irrigation system with a pinch valve compressing the irrigation tube, a foot-switch for activating the ultrasound, the LithoClast and both together, and a stone bucket at the outlet tube are new features. Between February 1999 and August 2001, 68 patients were treated by PNL with the new device; 35 had complete and 33 had partial staghorn calculi. PNL was administered under fluoroscopic control and with the patient prone. RESULTS: The mean (range) duration of surgery was 61 (42-119) min. The complete stone-free rate was 66% after the first PNL; of the 68 patients, 16 received a second PNL, giving a final stone-free rate of 76% and 80%. The stone was composed of calcium oxalate monohydrate (COM) in 13%, COM with uric acid in 35%, apatite in 20% and cystine in 11%. Clinically the new lithotripter was very effective, producing smaller stone particles and thus fewer residual stone fragments after PNL than with the LithoClast or ultrasonic fragmentation alone. CONCLUSION: The new lithotripter provides easily managed and highly effective stone fragmentation of all stones, regardless of their composition.     

Ureteroscopic lithotripsy in Trendelenburg position for proximal ureteral calculi: a prospective,randomized, comparative study

Purpose

We conducted a prospective, randomized, comparative study to compare the clinical outcome between the Trendelenburg position ureteroscopic lithotripsy (tURSL) and the conventional position ureteroscopic lithotripsy (cURSL) for the management of single proximal ureteral stone.

Methods

From January 2012 to September 2013, consecutive patients with single proximal ureteral calculi less than 2 cm and planned for ureteroscopic lithotripsy at our institution were enrolled in this study. The eligible patients were randomized into cURSL group and tURSL group according to sequence of random numbers generated by computer. In tURSL group, patients were turned into a Trendelenburg lithotomy position with head down 30° while the conventional lithotomy position was applied in cURSL group. URSL was performed using a 6/7.5F semi-rigid ureteroscope with holmium laser. When retropulsion occurred, the stones fragments were followed by semi-rigid ureteroscope up to the renal collecting system. The Olympus P5 flexible ureteroscope was used if there was any suspicion of stone migration into lower calices or incomplete stone fragmentation by semi-rigid ureteroscope. Patients’ demographics between the two groups, perioperative course, clinical outcome and complication rates were compared. Data were analyzed using Chi-square test, Fisher’s exact test or Student’s t test. Binary logistic regression analysis was applied to estimate the effects of surgical position and stone size on stone migration.

Results

A total of 355 cases were finally analyzed in this study (176 in cURSL group and 179 in tURSL group). The mean operative time was significantly prolonged in cURSL group than in tURSL group, while the stone-free rate (SFR) at 4 weeks was significantly higher in tURSL group. A statistically significant difference was found in stone migration rate between the two groups (26.7 vs. 43.6 %, P = 0.001). In the stone migration subsetting, less stones fragments were found to migrate into lower calices in tURSL stone migration subgroup (P = 0.000). Also, the flexible ureteroscope utilization as well as the operative time was significantly decreased in tURSL stone migration subgroup (25.5 vs. 72.3 %, P = 0.000), (44.96 ± 11.0 min vs. 59.17 ± 9.2 min, P = 0.000) with higher SFR after retrograde intrarenal surgery (RIRS) (96.2 vs. 74.5 %, P = 0.000).

Conclusion

The tURSL was safe and highly efficacious for the management of proximal ureteral calculus, especially in nonobese patient. Even with important stone migration risk, it rendered higher SFR and less operative time compared with cURSL. Moreover, less utilization of flexible ureteroscope and decreased deflection time in tURSL could potentially reduce the medical cost.     

Clinical efficacy of combined lithoclast and lithovac stone removal during ureteroscopy

PURPOSE: Pneumatic lithotripsy has proved to be an extremely safe, efficient and low cost intracorporeal fragmentation modality. Unfortunately proximal migration of fragments into inaccessible areas in the intrarenal collecting system is a potential limitation during ureteroscopic procedures. Moreover, the lack of an efficient mechanism of stone retrieval further limits the widespread application of this technique. The newly developed Lithovacdagger suction device was designed to be combined with pneumatic lithotripsy during ureteroscopic stone removal. We evaluated the effectiveness of this combination for overcoming these limitations. MATERIALS AND METHODS: Between February and December 1998, 21 patients underwent pneumatic lithotripsy of ureteral calculi combined with use of the Lithovac suction probe. Stone area was 20 to 320 mm.2 (mean 84). Of the stones 71% and 29% were in the distal, and proximal and/or mid ureter, respectively. We used a 0.8 mm. pneumatic lithotripsy probe placed through a 4.8Fr Lithovac probe at a pulse frequency of 12 Hz. and pressure of 2 atmospheres. RESULTS: Mean operative time was 42 minutes and the stone fragmentation rate was 100%. There were no complications in our series and no proximal migration of fragments. The overall stone-free rate was 95% at 3-month followup. CONCLUSIONS: Using the Lithovac suction device greatly facilitates pneumatic lithotripsy during ureteroscopic stone removal. This combination not only prevents fragment migration, but also aids in maintaining a clear endoscopic field of view, allowing efficient, safe and effective stone fragmentation.     

输尿管镜下NTrap网篮配合钬激光碎石术治疗输尿管结石

目的：探讨输尿管镜下NTrap网篮配合钬激光碎石术治疗输尿管结石的疗效及其安全性。方法：2005年1月～2009年12月应用NTrap网篮输尿管镜下配合钬激光碎石术治疗输尿管结石206例,并对临床资料进行分析。结果：一次手术碎石成功195例,成功率94．7％（195／206）;10例在碎石过程中结石被冲入肾盏内形成结石残留,术后行ESWL治愈;1例双侧输尿管结石因输尿管狭窄中转开放手术取出结石并切除狭窄段输尿管。所有患者术后无严重并发症发生。结论：输尿管镜下NTrap网篮配合钬激光碎石可以有效防止碎石逆行移位,避免术后结石残留于肾盏,是一种安全、有效的工具。     

输尿管镜气压弹导碎石术治疗儿童下尿路结石

目的：探讨儿童下尿路结石的治疗方法。方法：应用输尿管镜气压弹导碎石术经尿道或膀胱穿刺造瘘通道治疗儿童下尿路结石22例。结果：22例均一次成功击碎结石，治愈率100％。其中2例经膀胱穿刺造瘘通道碎石，术中即将结石取净。20例经尿道膀胱内碎石，术后结石均排净。无一例有并发症。结论：输尿管镜下气压弹导碎石治疗儿童下尿路结石，创伤小，成功率高，并发症少，为一种较理想的治疗方法。     

In vitro comparison of stone retropulsion and fragmentation of the frequency doubled, double pulse nd:yag laser and the holmium:yag laser

PURPOSE: The frequency doubled, double pulse Nd:YAG (FREDDY) laser (World of Medicine, Berlin, Germany) functions through the generation of a plasma bubble. Upon bubble collapse a mechanical shock wave is generated, causing stone fragmentation. This mechanism of action is in contrast to the holmium laser, which cause stone destruction by vaporization. Observed clinical stone retropulsion and fragmentation with the FREDDY and holmium lasers has prompted a series of in vitro experiments designed to compare laser induced retropulsion and fragmentation with those of a holmium laser and pneumatic lithotrite. MATERIALS AND METHODS: For retropulsion a hands-off underwater laboratory setup, including a horizontally oriented silicone tube 1.3 cm in diameter and a holder to keep the stone phantom in contact with the quartz laser fiber or pneumatic probe, was used. Previously weighed, cylindrical Bego stone phantoms (Bego USA, Smithfield, Rhode Island) were placed in the apparatus. Stone fragmentation was performed with the FREDDY or holmium laser, or the pneumatic lithotripter. The FREDDY and holmium lasers were tested at similar pulse energy and frequency settings. As a standard for comparison, a pneumatic lithotrite was tested with a semirigid probe and single pulse settings of 100, 200 and 300 kPa. Stone phantoms underwent 30 shocks per setting. Mean net retropulsion, defined as the final resting point of the stone, as determined by direct measurement, was recorded for each setting. For fragmentation plaster of Paris stone phantoms of known weights were used to compare the fragmentation ability of each laser. Stones phantoms were placed in a hands-off underwater setup, consisting of an inverted silicon syringe and holder immersed in tap water. The laser fiber (365 microm for the holmium and 280 microm for the FREDDY) was placed through the tip of the syringe in contact with the stone phantom. A total of 24 stones were divided into 4 groups of 6 per group. Two groups were fragmented with the FREDDY laser at 300 and 400 J total energy. The other 2 groups were fragmented using the holmium laser at 300 and 480 J total energy. Fragmentation efficiency was determined as percent weight loss. RESULTS: For retropulsion at 160 mJ the FREDDY laser caused stone retropulsion to a mean distance of 7.6, 8.1 and 6.8 cm at settings of 5, 10 and 15 Hz, respectively. At 0.8 J the holmium laser retropulsed the stone to a mean distance of 3.3 and 4.9 cm at settings of 5 and 10 Hz, respectively. The pneumatic device caused stone retropulsion a mean distance of 8.5, 9.9 and 13.8 cm at pressure settings of 100, 200 and 300 kPa, respectively. The FREDDY laser generally caused less retropulsion than the pneumatic device, although this difference was only significant at the highest pneumatic lithoclast setting (p <0.05). At clinically relevant settings the FREDDY laser caused significantly more retropulsion than the holmium laser (p <0.05). For fragmentation at total energy settings of 300 and 400 J the FREDDY laser resulted in 44.9% and 86.8% weight loss, respectively (p <0.05). At settings of 300 and 480 J the holmium:YAG laser resulted in 3.3% and 7.1% weight loss, respectively (p <0.05). CONCLUSIONS: At lower frequency settings stone retropulsion was significantly greater with the FREDDY laser compared with the holmium laser. However, retropulsion was significantly less than that caused by the pneumatic lithotripter at all settings. Therefore, we recommend the use of an occlusive device, such as the Stone Cone (Boston Scientific, Natick, Massachusetts) proximal to the calculus during intracorporeal ureteral lithotripsy and in the ureteropelvic junction during percutaneous laser nephrostolithotomy. In vitro stone fragmentation was significantly greater with the FREDDY laser than with the holmium:YAG laser, suggesting that the FREDDY may offer a low cost alternative to the holmium:YAG laser lithotrite in select patients.     

组配碎石吸石系统处理尿路结石

目的 探讨利用原有器械组配碎石吸石系统,处理膀胱结石、肾结石等尿路结石的方法.方法 2010年12月至2011年8月收治膀胱结石患者4例.均为男性.年龄42～79岁,平均63岁.两例合并尿道狭窄,其中一例患者曾有骨盆骨折、尿道断裂史,尿道狭窄几近闭锁,留置有膀胱造瘘管.另两例为前列腺增生合并膀胱结石.通过医院原有设备,...     

Efficacy and safety of the Accordion® stone-trapping device: in vitro results from an artificial ureterolithotripsy model

One of the challenges of intracorporeal ureterolithotripsy is undesired stone migration. Stone-trapping devices have been designed to prevent this quite common phenomenon. These devices have to be effective in terms of ureteral obstruction and safe in terms of resistance to the action of commonly used lithotriptors. This work was conducted to evaluate the efficacy and safety of the recently approved Accordion^® stone-trapping device in vitro. In a rigid, submerged ureteral model with two different diameters (8 and 10 mm), artificial stones were positioned in direct contact with the engaged Accordion^® device. A defined number of pneumatic pulses of the LithoClast^® master at different performance levels was applied and the migration distance of the stone was measured after each single pulse. As a control, the same series was repeated without the stone-trapping device. Secondly, the Accordion device was exposed to a previously defined number of pneumatic or Ho:YAG-laser pulses, in direct contact with the lithotripsy probe, up to a total activation time of 2 min. At different time points, the device was controlled for damage and functionality. The mean stone migration distance without the Accordion^® device was between 39.2 and 52.8 mm and between 37.8 and 75.4 mm in the 8 and 10 mm tubes, respectively. In comparison, the stone or fragment travelling distance with the device was in the 0–2 mm range. This difference was highly significant. Both pneumatic and laser lithotriptor did not affect the functionality of the Accordion^® device. The Ho:YAG laser causes small perforations of the film without affecting the devices’ stability. The Accordion device appears to be highly efficient and safe in vitro. Clinical trials will have to assess its value in endourological practice. Randomised comparative trials comparing different stone-trapping devices are needed.     

Extracorporeal lithotripsy endoscopically controlled by ureterorenoscopy (LECURS): a new concept for the treatment of kidney stones—first clinical experience using digital ureterorenoscopes

Purpose

To evaluate the feasibility and usefulness of extracorporeal lithotripsy endoscopically controlled by simultaneous flexible ureterorenoscopy (LECURS) and combined with Holmium laser lithotripsy for kidney stones surgery.

Methods

Retrograde flexible ureteroscopy allowed stone visualization and intrarenal relocation when possible. Extracorporeal schock wave lithotripsy (ESWL) was performed under direct vision allowing constant focal zone adjustment for optimal stone fragmentation. Holmium laser lithotripsy was used simultaneously when necessary. Post-operative assessment included ultrasound at day one and abdominal CT scan 3 weeks later to evaluate for residual fragments.

Results

Six patients with kidney stones were recruited including 3 with relative contraindication to ESWL. One patient had a stone beyond an infundibular stenosis and 2 had multiple stones in a horseshoe kidney with an uretero-pelvic junction (UPJ) stricture. A 100 % stone fragmentation rate was obtained. Post-operative ultrasound was normal in 5 patients and showed slight peri-renal infiltration in the other. One patient developed an obstructive pyelonephritis requiring antibiotics and changing a double J to a ureteral catheter. No other complications were noted. Three patients (50 %) were stone free after LECURS. Three patients underwent a second-look procedure for small (<3 mm) retained residual fragments. No damage was seen with the digital ureteroscopes, laser fibers or stone baskets.

Conclusions

This initial experience with LECURS has shown to be feasible and safe. This opens the opportunity for further evaluation of this approach in order to improve outcomes of both approaches.     

弹道碎石联合体外冲击波碎石治疗输尿管结石

目的探讨气压弹道碎石术联合体外冲击波碎石(extracorporeal shock wave lithotripsy,ESWL)治疗输尿管结石的临床价值. 方法采用气压弹道碎石术联合ESWL治疗输尿管结石365例. 结果 365例中,360例(98.6%)成功,2例失败(改开放手术),3例输尿管穿孔.80例配合ESWL.术后2周复查,结石均排净. 结论气压弹道碎石术联合ESWL治疗输尿管结石具有疗效高,损伤小,适应证广等优点.     

经皮肾镜气压弹道联合超声碎石治疗复杂性肾结石

目的探讨经皮肾镜气压弹道联合超声碎石术治疗复杂性肾结石的方法及疗效.方法 B超引导下穿刺并扩张建立F24经皮肾镜操作通道.在F20.8肾镜下采用瑞士EMS Ⅲ代气压弹道联合超声碎石机,Ⅰ期粉碎结石并主动吸出体外.结果单侧结石清除时间5～115 min,平均35 min.结石粉碎率100%,结石取净率91.8%(45/49).术后4～6 d拔除肾造瘘管,拔除肾造瘘管2 d后拔除导尿管,术后1个月拔除双J管.术后住院6～12 d,平均8 d.4例肾盏内或输尿管上段残留结石,直径＜1 cm,术后3周行体外冲击波碎石1～2次,均顺利排出体外.49例随访1～6个月,平均3.2月,均无严重出血及感染,无结石复发.结论经皮肾镜下气压弹道联合超声碎石术治疗复杂性肾结石具有高效、安全的特点,值得临床推广应用.     

Strahlenbelastung der Patienten bei der ureterorenoskopischen Steinentfernung

Background

We determined the intraoperative patient radiation exposure during ureteroscopic extraction of ureteral or renal stones.

Material and methods

The investigation was carried out in 215 patients who underwent ureteroscopy for ureteral or renal stone extraction. Radiation exposure was measured as dose-area product (DAP) within the X-ray beam. The effective abdominal dose was calculated using the specific conversion factor of 0.00323 mSv/µGy×m².

Results

Depending on the stone location (i.e. ureter or kidney), the type of ureteroscopy (i.e. semirigid or flexible) and type of stone removal (i.e. simple stone extraction or intracorporeal laser lithotripsy), the intraoperative patient radiation exposure (effective dose ED) ranged from 0.67 mSv (DAP 221.9 µGy×m²) to 2.23 mSv (DAP 744.2 µGy×m²).

Conclusion

Patient radiation exposure during ureteroscopic stone extraction is comparable to patient radiation exposure using plain film urography or low-dose non-contrast-enhanced computed tomography for diagnosis of urolithiasis.     

输尿管镜气压弹道碎石术治疗输尿管结石的临床分析

目的 探讨输尿管镜气压弹道碎石术治疗各段输尿管结石的疗效.方法 回顾性分析我院2004年1月至2010年1月应用输尿管镜气压弹道碎石术治疗的317例单纯输尿管结石患者的临床资料.结果 一次性碎石成功率89.97％ (296/329),术中并发症发生率1.22％ (4/329),碎石成功患者术后结石排净率97.30％(288/296).结石横径≤1 cm和＞1 cm两个亚组在碎石成功率、术后1个月无石率方面差异比较均无统计学意义(P＞0.05) ;术中并发症方面,输尿管上段结石＞1 cm组高于≤1 cm 组(P＜0.05),而输尿管中、下段结石两亚组间无明显差异(P＞0.05).结论 输尿管镜下气压弹道碎石术安全,有效,损伤小,可作为治疗输尿管中下段结石及体外冲击波碎石失败的输尿管上段结石的有效治疗方法之一.     

Ureteric stents compromise stone clearance after shockwave lithotripsy for ureteric stones: results of a matched-pair analysis

OBJECTIVE

To identify the effect of the presence of a ureteric stent on the outcome of extracorporeal shockwave lithotripsy (ESWL), by comparing patients with ureteric stones with matched‐pair analysis.

PATIENTS AND METHODS

Patients undergoing ESWL with the Sonolith Vision lithotripter (Technomed Medical Systems, Vaulx‐en‐Velin, France) were identified from our prospectively maintained database. Only adult patients with a solitary, radio‐opaque, previously untreated ureteric stone were considered for further analysis. A follow‐up of ≥3 months with a plain abdominal film was used to identify residual fragments. Patients were exactly matched for gender, side, location in the ureter and size (in two dimensions, within ±2 mm). If both diameters could not be matched exactly, the size was extended to ±1 mm and then to ±2 mm of both diameters. An effort was finally made to match patients by age. The treatment outcome in terms of stone‐free rates was assessed and compared using McNemar’s test.

RESULTS

In all, 45 patients with a ureteric stent in place during ESWL were identified. The only patient who could not be adequately matched was a 40‐year‐old man with an 8 × 3 mm stone in the upper ureter. The best/closest match for age was selected. Most stones were in the upper ureter (77%); the mean stone size was 8.5 and 8.6 mm, respectively, with no statistical differences between the groups for age and size of stones (P = 0.41 and 0.86, Student’s t‐test). In 12 pairs, only patients with no stent were stone‐free, compared to two pairs where the patient with a stent was stone‐free. Using McNemar’s test, the odds ratio was 6.0 (95% confidence interval 1.3–55.2) and the difference between the groups was statistically significant (P = 0.016).

CONCLUSION

These results show that the presence of a stent is associated with a worse outcome after ESWL for ureteric stones. Ureteric stents should still be used in cases of obstruction, when there is a risk of sepsis, and in patients with intolerable pain or deteriorating renal function. However, their use in patients offered ESWL for ureteric stones should be considered with caution.     

A comparison between an in vitro ureteroscopic stone size estimation and the stone size measurement with the help of a scale on stone baskets

Introduction

Endoscopic treatment of ureter stones and renal calculi relies on the surgeon’s estimation of the stone size for both lithotripsy and removal of stones or stone fragments. We therefore compared precision and reliability of the endoscopic estimation of stone size by the surgeon with measurements on a scale on a stone basket.

Materials and methods

Two surgeons (one high experienced and one low experienced) first estimated, then measured the size of 12 stones differing in size and color using different stone baskets (2.5, 3.0, 4.0 Ch) each via a semirigid renoscope in an artificial ureter under water repeatedly on two different days. All together, we had 288 measurements and 288 estimations.

Results

On the whole, the accuracy of the estimation diminished with bigger stones. There is an increasing underestimation with increasing stone size. Factors, which significantly influence the estimation, are the operating surgeon, the color of the stone, the time sequence, and the size of the closed basket, which was held beside the stone. The accuracy of the measurement of the stone baskets is not as good as the estimation. The small 2.5-Ch basket is the most accurate in measuring big stones (>6 mm), the 3.5 Ch in intermediate stones (3–6 mm), the big basket (4.0 Ch) in small stones (<3 mm).

Conclusion

This first attempt at validation of a scale on stone baskets shows different results for each basket which could be systematically improved. Until now, the estimation of the surgeons is better than the measurement, but it is also influenced by factors like the surgeon or the color of the stone.

     

Efficacy of dretler stone cone in the treatment of ureteral stones with pneumatic lithotripsy

INTRODUCTION: Ureteroscopic pneumatic lithotripsy has been used to treat ureteral calculi for more than 10 years. Owing to its low price and high degree of effectiveness, it has become the most popular ureteroscopic lithotripsy device in use worldwide. The major limitation of the technique is the occurrence of proximal fragment migration during intracorporeal lithotripsy. The Dretler Stone Cone is a new device developed to prevent stone migration during ureteroscopic lithotripsy. The aim of this study was to assess the efficacy and safety of this device during ureteroscopic pneumatic lithotripsy. PATIENTS AND METHODS: Twenty-three consecutive patients having ureteral stones were treated with a 10-Fr semirigid ureteroscope, a Stone Cone Nitinol Retrieval Device, and a pneumatic lithotriptor. In all patients Stone Cones were placed under visual guidance through the working channel of the ureteroscope. Outcomes of this device were then compared with the outcomes of 23 previous patients with stones of similar sizes and locations who had undergone ureteroscopic pneumatic lithotripsy prior to the Stone Cone being available at our clinic. RESULTS: All patients in the study group were stone-free after the procedure. No stone fragments were noted to migrate to proximal segments. CONCLUSIONS: The Dretler Stone Cone effectively prevents proximal stone migration and facilitates stone fragmentation during pneumatic lithotripsy with no risk of ureteral injury. It has only a small extra cost.