Successful Fragmentation Research Articles

The Role of Plain Radiography in Predicting Renal Stone Fragmentation by Shockwave Lithotripsy in the Era of Noncontrast Multidetector Computed Tomography

The objective of this study is to determine if plain radiography has a role in prediction of stone fragmentation by shockwave lithotripsy (SWL). Our study included 106 patients undergoing SWL for renal stones. Based on plain radiography criteria, stones were classified according to density, homogeneity, and outline. We compared the success of SWL in fragmentation of stones with a density equal to or less than bone, nonhomogeneous stones, and stones with irregular outline to its success in stones with a density more than bone, homogeneous stones, and stones with smooth outline. In plain radiography, stone density equal to or less than bone, nonhomogeneous stones, and stones with irregular outline showed successful SWL fragmentation in 88.8%, 91.2%, and 90.6%, respectively. Stones with a density more than bone, homogeneous stones, and stones with smooth outline showed successful SWL fragmentation in 52.9%, 52.6%, and 57.1%, respectively. CT attenuation value was significantly less in stones successfully fragmented by SWL compared with nonfragmented stone (649±169 and 1465±256, respectively). In homogeneous stones with smooth outline having a density more than bone, we found a significantly lower CT attenuation in patients with successful stone fragmentation by SWL compared with those with failed stone fragmentation (690.9±171 and 1462±212, respectively). In relatively large solitary renal pelvic stones, plain radiography can predict the success of stone fragmentation by SWL. Nonhomogeneous stones with irregular outline and a density equal to or less than bone are expected to be successfully fragmented by SWL. Noncontrast CT is only needed, to predict success of SWL, in cases of homogeneous stones with smooth outline and density more than bone.

Femtosecond Laser-Assisted Cataract Surgery in Management of Phacomorphic Glaucoma

To report the use of femtosecond laser-assisted cataract surgery in management of phacomorphic glaucoma. An 89-year-old patient developed acute phacomorphic glaucoma in her right eye with elevated intraocular pressure (62 mm Hg), shallow anterior chamber, and mature cataract. After conservative antiglaucoma therapy and Nd:YAG iridotomy, femtosecond laser-assisted cataract surgery was performed. A Malyugin ring was implanted for mechanical pupil dilatation and a 4.8-mm capsulorrhexis and lens fragmentation was performed using a femtosecond laser system (Alcon LenSx Inc., Aliso Viejo, CA) followed by in-the-bag intraocular lens implantation. Intact 4.8-mm capsulorrhexis and successful lens fragmentation could be performed using femtosecond laser. After cataract surgery, the patient's visual acuity increased from hand motions to 0.4 (Snellen 4/10) and the intraocular pressure returned to normal range without antiglaucoma drop therapy. The results indicate that femtosecond laser can be successfully used in certain cases of phacomorphic glaucoma, even if mechanical pupil dilatation is needed.

Analysis of the Errors in the Electrostatically Embedded Many-Body Expansion of the Energy and the Correlation Energy for Zn and Cd Coordination Complexes with Five and Six Ligands and Use of the Analysis to Develop a Generally Successful Fragmentation Strategy

In the present paper, we apply the electrostatically embedded many-body expansion of the correlation energy (EE-MB-CE) to the calculation of zinc-ligand and cadmium-ligand bond dissociation energies, and we analyze the errors due to various fragmentation schemes in a variety of neutral, positively charged, and negatively charged Zn2+ and Cd2+ coordination complexes. As a result of the analysis, we are able to present a new, simple, and unambiguous fragmentation strategy. Following this strategy, we show that both methods perform well for zinc-ligand and cadmium-ligand bond dissociation energies for all systems studied in the paper, including a model of the catalytic site of the zinc-bearing anthrax toxin lethal factor (LF), which has garnered substantial attention as a target for drug development. To draw general conclusions we consider ten pentacoordinate and hexacoordinate zinc and cadmium containing coordination complexes, each with 10 or 15 different fragmentation schemes. By analyzing errors, we developed a prescription for the optimal fragmentation strategy. With this scheme, and using MP2 correlation energies as a test, we find that the electrostatically embedded three-body expansion of the correlation energy (EE-3B-CE) method is able to reproduce all 53 conventionally calculated bond energies with an average absolute error of only 0.59 kcal/mol. The paper also presents EE-MB-CE calculations using the CCSD(T) level of theory on an LF model system. With CCSD(T), EE-3B-CE has an average error of 0.30 kcal/mol.

Factors Affecting the Outcome of Extracorporeal Shock Wave Lithotripsy for Unilateral Urinary Stones in Children: A 17-Year Single-Institute Experience

PurposeExtracorporeal shock wave lithotripsy (ESWL) is a first-line treatment for pediatric urinary stone disease. We aimed to determine the factors affecting the outcome of ESWL for unilateral urinary stones in children.Materials and MethodsA total of 81 pediatric patients aged 0 to 16 years with urinary stones treated by ESWL from January 1995 through May 2012 were retrospectively reviewed. All patients were required to have unilateral urinary stone disease. Children who underwent other surgical procedures before ESWL were excluded. Outcomes evaluated after ESWL were the stone-free rate at 3 months after ESWL, success within a single session, and success within three sessions. Factors affecting the success within three sessions were also analyzed.ResultsThe final analysis was for 42 boys and 22 girls (mean age, 9.2±5.2 years). Of these 64 patients, 58 (90.6%) were treated by ESWL without other surgical procedures and 54 (84.4%) were successfully treated within three ESWL sessions. In the multivariate analysis, multiplicity (odds ratio [OR], 0.080; 95% confidence interval [CI], 0.012 to 0.534; p=0.009) and large stone size (>10 mm; OR, 0.112; 95% CI, 0.018 to 0.707; p=0.020) were significant factors that decreased the success rate within three ESWL sessions.ConclusionsMost of the pediatric urinary stone patients in our study (90.6%) were successfully treated by ESWL alone without additional procedures. If a child has a large urinary stone (>10 mm) or multiplicity, clinicians should consider that several ESWL sessions might be needed for successful stone fragmentation.

FragIt: A Tool to Prepare Input Files for Fragment Based Quantum Chemical Calculations

Near linear scaling fragment based quantum chemical calculations are becoming increasingly popular for treating large systems with high accuracy and is an active field of research. However, it remains difficult to set up these calculations without expert knowledge. To facilitate the use of such methods, software tools need to be available to support these methods and help to set up reasonable input files which will lower the barrier of entry for usage by non-experts. Previous tools relies on specific annotations in structure files for automatic and successful fragmentation such as residues in PDB files. We present a general fragmentation methodology and accompanying tools called FragIt to help setup these calculations. FragIt uses the SMARTS language to locate chemically appropriate fragments in large structures and is applicable to fragmentation of any molecular system given suitable SMARTS patterns. We present SMARTS patterns of fragmentation for proteins, DNA and polysaccharides, specifically for D-galactopyranose for use in cyclodextrins. FragIt is used to prepare input files for the Fragment Molecular Orbital method in the GAMESS program package, but can be extended to other computational methods easily.

Does the Radiologic Technologist or the Fluoroscopy Time Affect Treatment Success with Shockwave Lithotripsy?

The minimally invasive nature and effectiveness of shockwave lithotripsy (SWL) has made it one of the primary treatment modalities for urinary tract calculi. Several factors determining the success of SWL treatment have been studied, including stone factors (ie, location, size, and composition) and patient factors (ie, patient habitus and skin-to-stone distance). Our objective was to determine if either the assisting radiologic technologist or the amount of fluoroscopy time used has an impact on SWL success. We compared the outcome of 536 SWL treatments across three radiologic technologists. We also evaluated the average amount of fluoroscopy time used in treatment success vs failures in this same cohort. The outcomes measured were stone-free and successful fragmentation rate at 2 weeks and 3 months. Successful fragmentation was defined as being either stone free, having residual sand, or with an asymptomatic fragment ≤ 4 mm on radiography of the kidneys, ureters, and bladder. The patients treated by the three different radiologic technologists were comparable with respect to body mass index, stone side and location, presence of ureteral stent, and mean stone area (mm(2)). The stone-free and successful fragmentation rates at 2 weeks and 3 months between the three radiologic technologists were not significantly different. When examining fluoroscopy time, we found a significantly greater mean fluoroscopy time was used in treatments with successful fragmentation at 2 weeks (3.16 min vs 2.72 min, P=0.0001) and 3 months (3.12 min vs 2.75 min, P=0.0015) compared with treatment failures. The radiologic technologist did not have a significant impact on SWL treatment outcome at 2 weeks and 3 months. Successful SWL fragmentation at 2 weeks and 3 months, however, was associated with a greater amount of fluoroscopy time, suggesting that using fluoroscopy to ensure accurate targeting during SWL is important for successful fragmentation.

Pneumatic Ureteroscopic Lithotripsy: Is It Still a Reasonable Treatment Option for Multiple Ureteric Stones?

Objectives: To assess the efficacy and safety of ureteroscopic pneumatic lithotripsy for multiple ureteric stones. Materials and Methods: 36 patients with multiple ureteric stones were treated with ureteroscopic lithotripsy (URSL). A 8/9.8-Fr Wolf semirigid ureteroscope and pneumatic lithotripter were used for stone fragmentation. Results: 87 stones were treated with URSL. Successful fragmentation was achieved in 77 (88.5%) of the stones. The retreatment rate was 11.5%. The stone-free rate (SFR) of lower ureteric stones (93.3%) and middle ureteric stones (87.5%) was significantly higher compared with upper (73.3%) ureteric stones (p < 0.05). For patients with stones less than 1 cm and greater than 1 cm, the SFR was 91.5 and 75.0%, respectively (p < 0.05). Perforation occurred in 1 patient, mucosal injury occurred in 5 and stone migration in 5. No long-term complication was observed in any patient. Conclusions: Ureteroscopic pneumatic lithotripsy is still a reasonable treatment option for multiple ureteric stones. The procedure has high success rates with minimal morbidity. However, success rate can be affected by stone size and ureteric location.

Influence of Ureteral Stone Components on the Outcomes of Electrohydraulic Lithotripsy

PurposeWe evaluated the influence of urinary stone components on the outcomes of ureteroscopic removal of stones (URS) by electrohydraulic lithotripsy (EHL) in patients with distal ureteral stones.Materials and MethodsPatients with a single distal ureteral stone with a stone size of 0.5 to 2.0 cm that was completely removed by use of EHL were included in the study. Operating time was defined as the time interval between ureteroscope insertion and complete removal of ureteral stones. Ureteral stones were classified into 5 categories on the basis of their main component (that accounting for 50% or more of the stone content) as follows: calcium oxalate monohydrate (COM), calcium oxalate dihydrate, carbonate apatite (CAP), uric acid (UA), and struvite (ST).ResultsA total of 193 patients (131 males and 62 females) underwent EHL. The mean operating time was 25.1±8.2 minutes and the mean stone size was 1.15±0.44 cm. Calcium oxalate stones accounted for 64.8% of all ureteral stones, followed by UA (19.7%), CAP (8.3%), and ST (7.2%) stones. The mean operating time was significantly longer in the UA group (28.6±8.3 minutes) than in the COM group (24.0±7.8 minutes, p=0.04). In multivariate analyses, the stone size was negatively associated with the odds ratio (OR) for successful fragmentation. UA as a main component (OR, 0.42; 95% confidence interval, 0.20 to 0.89; p=0.023) was also found to be significantly important as a negative predictive factor of successful fragmentation after adjustment for stone size.ConclusionsThe results of the present study suggest that successful fragmentation by URS with EHL could be associated with the proportion of the UA component.

Single-operator cholangioscopy-guided laser lithotripsy in patients with difficult biliary and pancreatic ductal stones (with videos)

Scant data exist on the utility of the holmium:yttrium-aluminum-garnet laser for the treatment of biliary or pancreatic duct stones. To evaluate the efficacy and safety of fiberoptic probe and catheter system-guided holmium laser lithotripsy of difficult biliary and pancreatic duct stones. Prospective study. Tertiary-care referral center. This study involved 64 patients who underwent holmium laser stone fragmentation. A total of 64 patients (60 bile duct stones, 4 pancreatic duct stones) underwent endoscopic retrograde stone fragmentation with a holmium laser and a fiberoptic probe and catheter system. The inclusion criterion for bile duct stones was stones not amenable to retrieval by mechanical lithotripsy and/or balloon sphincteroplasty or standard techniques. Pancreatic duct stones included in this study were not amenable to removal by stone retrieval basket or balloon. Rates of ductal clearance and procedural complications. All 64 patients had successful fragmentation of biliary and pancreatic duct stones with the holmium laser. Fifty of 60 patients (83.3%) had complete biliary duct clearance after a single session; 10 patients required an additional session. All pancreatic duct stones were fragmented in a single session. Mean duration of ERCP sessions was 45.9 minutes (range 30-90 minutes). Complications were mild and were encountered in 13.5% of patients; fever (n = 3), transient abdominal pain (n = 4), and biliary stricture (n = 1). No comparative treatment group. The fiberoptic probe and catheter system facilitates transpapillary access for holmium laser fragmentation of difficult biliary and pancreatic duct stones. The technique is safe and highly effective for single-setting duct clearance. Complications are minimal and transient.

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

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. 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. 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. 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). 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.

Management of calcular anuria in adults caused by ureteric stones: By using of ureteroscopy and holmium laser

PurposeTo present our clinical outcomes in the management of anuria in adult patients caused by ureteral calculi by using of ureteroscopy and holmium laser. Materials and methodsNineteen patients presented with calcular anuria with ages between 19 and 48years. The presentation was anuria with serum creatinine levels of 2–5.5mg% (mean 3.5) and hyperkalemia in nine patients (5.2–6.1mmol/L). There were bilateral ureteric stones in 14 (73.7%) and unilateral in five (26.3%) with single functioning kidney. Thirty-three ureteroscopic procedures were performed for 19 patients including bilateral ureteroscopy in 14. Laser lithotripsy was delivered using holmium laser via 356μm laser fibre, with energy (1–1.2J) and pulse rate (10Hz). Post-operatively, monitoring of urine output, serum creatinine and K levels was done until normal values were obtained. ResultsUreteroscopy was performed for all 19 patients (33 procedures), but laser lithotripsy was done successfully in 30 procedures. The operative time was 46min (25–70). The successful fragmentation rate was (100%). The stone-free rate was 90.9%. There were mucosal abrasions in 6 (31.5%), and mild to moderate haematuria in 9 (47.4%), and high fever in two patients (10.5%). Serum creatinine and potassium levels returned to normal within 7–10days. Urine output gradually reached normal level within a week. ConclusionsUreteroscopy and holmium laser lithotripsy represent an effective and safe modality for the treatment of anuria caused by ureteral calculi.

Comparison of Holmium Laser and Pneumatic Lithotripsy in treatment of ureteral stones

Introduction: To compare the effectiveness and complications of treatment of ureteric stones by holmium laser lithotripsy and pneumatic lithotripsy. &#x0D; Methods: Comparison of 100 patients with ureteric stones, 50 of whom were treated with pneumatic lithotripsy and 50 with holmium laser lithotripsy was done and effectiveness and complications of the two were analysed. &#x0D; Results: Both the groups were similar in respect to sex, age, stone size and location of the stones. Successful stone fragmentation occurred in 94 % on pneumatic group and in 92 % on laser group. On following the patients for a month, stone free rate was 98 % in both the groups. None of the patients had any complications relating to the procedures. &#x0D; Conclusion: Although pneumatic lithotripsy has more retrograde migration of ureteric stones, the results are comparable to holmium laser. Other complications are very rare.

Comparison of Holmium Laser and Pneumatic Lithotripsy in treatment of ureteral stones

Introduction: To compare the effectiveness and complications of treatment of ureteric stones by holmium laser lithotripsy and pneumatic lithotripsy. &#x0D; Methods: Comparison of 100 patients with ureteric stones, 50 of whom were treated with pneumatic lithotripsy and 50 with holmium laser lithotripsy was done and effectiveness and complications of the two were analysed. &#x0D; Results: Both the groups were similar in respect to sex, age, stone size and location of the stones. Successful stone fragmentation occurred in 94 % on pneumatic group and in 92 % on laser group. On following the patients for a month, stone free rate was 98 % in both the groups. None of the patients had any complications relating to the procedures. &#x0D; Conclusion: Although pneumatic lithotripsy has more retrograde migration of ureteric stones, the results are comparable to holmium laser. Other complications are very rare.

A Clinical Nomogram to Predict the Successful Shock Wave Lithotripsy of Renal and Ureteral Calculi

Although shock wave lithotripsy is dependent on patient and stone related factors, there are few reliable algorithms predictive of its success. In this study we develop a comprehensive nomogram to predict renal and ureteral stone shock wave lithotripsy outcomes. During a 5-year period data from patients treated at our lithotripsy unit were reviewed. Analysis was restricted to patients with a solitary renal or ureteral calculus 20 mm or less. Demographic, stone, patient, treatment and 3-month followup data were collected from a prospective database. All patients were treated using the Philips Lithotron® lithotripter. A total of 422 patients (69.7% male) were analyzed. Mean stone size was 52.3±39.3 mm2 for ureteral stones and 78.9±77.3 mm2 for renal stones, with 95 (43.6%) of the renal stones located in the lower pole. The single treatment success rates for ureteral and renal stones were 60.3% and 70.2%, respectively. On univariate analysis predictors of shock wave lithotripsy success, regardless of stone location, were age (p=0.01), body mass index (p=0.01), stone size (p<0.01), mean stone density (p<0.01) and skin to stone distance (p<0.01). By multivariate logistic regression for renal calculi, age, stone area and skin to stone distance were significant predictors with an AUC of 0.75. For ureteral calculi predictive factors included body mass index and stone size (AUC 0.70). Patient and stone parameters have been identified to create a nomogram that predicts shock wave lithotripsy outcomes using the Lithotron lithotripter, which can facilitate optimal treatment based decisions and provide patients with more accurate single treatment success rates for shock wave lithotripsy tailored to patient specific situations.

Successful endoscopic resolution of a large gastric bezoar in a child

Bezoars are masses or concretions of indigestible materials found in the gastrointestinal tract, usually in the stomach. Case reports of childhood gastric bezoars (particularly phytobezoars) are rare. In this age group they represent a therapeutic challenge, because of the combination of hard consistency and great size. The present report concerns an 8-year-old boy with a history of high fruit intake, presenting with abdominal complaints due to a large gastric phytobezoar. Successful endoscopic fragmentation coupled with suction removal was accomplished, using a standard-channel endoscope. Although laborious, it has been shown to be an efficacious and safe procedure, completed in one session. Endoscopic techniques for pediatric bezoar management may thus be cost effective, taking into account the avoidance of surgery, the length of the hospital stay and the number of endoscopic sessions.

Emergency Ureteroscopic Treatment for Upper Urinary Tract Calculi Obstruction Associated with Acute Renal Failure: Feasible or Not?

To determine the efficacy and safety of emergency ureteroscopy (URS) and holmium:yttrium-aluminum-garnet (Ho:YAG) laser lithotripsy for ureteral calculi that are associated with acute renal failure (ARF). We retrospectively evaluated a cohort of 49 patients who underwent URS from November 2005 to November 2008 for ARF that was caused by calculi obstruction of the upper urinary tract. The mean (maximal diameter) stone size was 1.48 cm. Acute renal failure was demonstrated by oliguria or anuria and marked increase in serum creatinine and blood urea nitrogen levels. All the patients were treated with URS and Ho:YAG laser lithotripsy emergently. Ureteral stent placement was performed in all cases after lithotripsy. A plain film of the kidneys, ureters, and bladder and abdominal ultrasonography were performed to evaluate efficacy of treatment on the first day postoperatively. Serum creatinine and blood urea nitrogen levels and urine volume were successively monitored until they returned to normal. All patients had postoperative imaging, including ultrasonography and excretory urography, to confirm stone clearance and exclude late obstructive complications 3 months after URS. URS and laser lithotripsy were successfully performed in all patients. There were no major intraoperative complications, and no procedure was converted to open surgery. The mean operative time was 35 minutes. The successful fragmentation rate was 95.5%. The overall stone-free rate was 91.8%. Normal renal function returned in 46 (93.8%) patients within 7 days. No postoperative ureteral stricture occurred after 3 months. URS and Ho:YAG laser lithotripsy represent an effective and safe modality for treating patients with ARF that is caused by calculi obstruction of the upper urinary tract in strictly selected situations.

The management of ureteric stones

The earliest observations that acoustic shockwaves could fragment brittle materials were made in the 1950s. The first experience of treating renal calculi in humans using extracorporeal shockwave lithotripsy (SWL) was reported in 19801 and by 1983 the first commercially-produced lithotriptor was available, the Dornier HM-3. Its use quickly became wide-spread and it revolutionised themanagement of urinary stone disease from what had previously been entirely surgical to what has become almost exclusively minimally invasive. Although stone fragmentation rates were impressive, treatment with the HM-3 required general anaesthesia. The development of second-generation lithotriptors allowed local anaesthetic treatment but at the cost of less efficient stone fragmentation. Outcomes of treatment with the most contemporary fourth generation lithotriptors approach those of the HM-3, but as an out-patient procedure with oral or intravenous analgesia.2 Today, approximately 80% of all upper tract urinary stone disease is treated with SWL. This topic has been a perennial discussion point amongst urologists; although the latest guidelines have suggested that the stone-free rates for ureteroscopy are higher than with extracorporeal shockwave lithotripsy (ESWL), it is well recognised that the evidence base is weak with many of the studies being retrospective, with precious few randomised clinical trials. This controversy is well argued on both sides by the two sets of authors who are eminent in the field of ureteric stone treatment. However, for the practicing urologist, the decision-making process is not always so straightforward and the decision to intervene must be based not only on the clinical situation faced by the patient, but also by the level of resource available locally. The EAU Guidelines (2008) suggest that 98% of stones 15 mm); (ii) impacted stones; (iii) unfavourable anatomy; and (iv) those in whom two sessions of ESWL have failed to achieve successful fragmentation (T Knoll et al. EAU Update Series 3, 2005). In these scenarios, intervention in the form of ureteroscopy is to be preferred, whilst, in the mid-ureter, the options are equal given the issues in respect of locally available resources and expertise. In the distal ureter, traditionally ureteroscopy is the modality of choice due to the ease of access, high stone-free rates and minimum of complications.

The Role of Unenhanced Spiral Computerized Tomography in Prediction of Successful Fragmentation of the Renal Calculus by Extracorporeal Shock Wave Lithotripsy

Purpose: We evaluated the attenuation value of renal cal-culi on unenhanced axial computerized tomography (CT) as a predictor of calculus fragmentation by extracorporeal shock wave lithotripsy (ESWL). Patients and Methods: Fifty patients with renal calculi up to 20 mm were included in this prospective study. The calculus attenuation value was measured in Hounsfield units (HU) on unenhanced CT sections through the calculi. Patients were subsequently treated with ESWL. Results: Patients were grouped according to calculus attenuation value into 3 treatment groups, first those with stones less than 500 HU (20 patients), 2nd those with stones from 500 to 1,000 HU (14 patients) and 3rd those with stones greater than 1,000 HU (16 patients). Mean HU was calculated for each group. Of the 50 patients 41 (80%) underwent successful ESWL treatment. The stone clearance rate was 100% in group I (20 of 20 cases), 85.7% in group II (13 of 14), and 50% in group III (8 of 16). The clearance rate for stones with an attenuation value of greater than 1,000 HU was signifi-cantly lower than that for stones with a value of less than 1,000 HU (8 of 16 vs. 13 of 14 cases and 20 of 20 cases). Pa-tients in group III required a greater median number of shock waves for stone fragmentation than those in groups I and II. The mean attenuation value and number of shock waves required for calculus fragmentation correlated significantly. Conclusions: The CT attenuation value of renal calculi can help to differentiate stones that are likely to fragment easily on ESWL from those that would require a greater number of shock waves for fragmentation or may fail to fragment on ESWL.

Intraductal electrohydraulic lithotripsy by using SpyGlass cholangioscopy through a colonoscope in a patient with Roux-en-Y hepaticojejunostomy

The endoscopic approach to large bile duct stones may require the use of intraductal electrohydraulic lithotripsy (IEHL) performed under direct cholangioscopic visualization.1,2 In patients with Roux-en-Y biliary reconstruction after liver transplantation, endoscopic retrograde cholangiography is feasible using long-length endoscopes.3 We describe successful fragmentation of a large common hepatic duct stone by using cholangioscopy-guided IEHL delivered through a colonoscope in a patient with a Roux-en-Y hepaticojejunostomy.

Treatment of complicated upper urinary calculi with Ho: YAG laser lithotriptor by minimally invasive percutaneous nephrolithotomy

Objective To investigate the clinical outcomes of Ho: YAG laser lithotripter with minimal-ly invasive percutaneous nephrolithotomy incomplicated upper urinary calculi treatment. Methods Totally 12 eases of patients with upper ureteral calculi and 25 eases of renal calculi patients were treated with Ho: YAG laser lithotriptor by minimlly invasive percutaneous nephrolithotomy. Results All the upper ureteral calculi patients achieved stone-free at 1 session. And polypus( 1 ease) ,granulation(9eases) ,granulations wraped up(2 eases) were reseeted with Ho: YAG laser vaporization ablation. Of 25 eases with renal calculi 20 achieved stone free at 1 session. The remained stones ranged from 0. 5 to 0. 8 cm in 5 patients were expectorated in 1 month(2 eases treated by medicine and 3 eases treated by ESWEL). The overall successful stone fragmentation rate with stone-free ex-peetoration of the ureteral and renal calculi was 86. 4% ( 32/37 ). All the patients recovered well postoperatively and no major complications observed. Conclusion The technique of Ho: YAG laser lithotriptor with minimally invasive pereutaneous nephrolithotomy is safe and effective for the treatment of complicated upper urinary calculi, especially accompanied with polypus and granulation, and has advantages of minimal trauma and easy recovery. Key words: Minimally invasive percutaneous nephrolithotomy; Ho: YAG laser lithotriptor; Complicated Upper urinary calculi