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At least 235 records · Page 13Linked to original sources
PubMed2007

Combined electrohydraulic and holmium:YAG laser ureteroscopic nephrolithotripsy of large (greater than 4 cm) renal calculi.

PURPOSE: Percutaneous nephrolithotripsy is standard treatment for renal calculi larger than 2 cm. Modern flexible ureteroscopes and accessories using the complimentary effects of electrohydraulic lithotripsy and holmium:YAG laser lithotrites can treat large (greater than 4 cm) branched renal calculi in a minimally invasive fashion with similar or superior results. This report is an assessment of the safety and efficacy of ureteroscopic nephrolithotripsy monotherapy for the management of large (greater than 4 cm) branched renal calculi in the community setting. MATERIALS AND METHODS: A total of 16 patients with 17 branched renal calculi ranging from 41 to 97 mm (mean 65) in length and 560 to 2,425 mm2 (mean 1,169) in area underwent staged ureteroscopic nephrolithotripsy monotherapy. Obesity (body mass index greater than 30) was present in 81% and 38% were morbidly obese (body mass index greater than 40). An infectious etiology was present in 81% and hard stone components were present in 94%. All patients presented with hematuria, pain and/or recurrent urinary tract infection. Lithotripsy was performed with a single deflection flexible ureteroscope and predominantly electrohydraulic lithotripsy. Laser drilling was used (in 4) to weaken hard stones before electrohydraulic lithotripsy. Low intrarenal pressure was maintained by continuous bladder drainage and placement of a stiff safety wire. Visibility was maintained using manual pulsatile irrigation. RESULTS: All patients were rendered pain and infection-free. No patient required a blood transfusion and there was no change in serum creatinine. Mobile stone-free status was achieved in 15 of 17 renal units (88%) with a mean of 2.4 stages and 36 of 40 (90%) procedures performed on an outpatient basis. Operative time averaged 49 minutes per stage and 115 minutes per calculus. There were 3 patients admitted for fever and 1 patient (90 years old) admitted for pneumonia 3 days postoperatively. There were also 3 patients with calculi larger than 75 mm who required ureteroscopic management of steinstrasse. CONCLUSIONS: Staged ureteroscopic nephrolithotripsy of large renal calculi is feasible with low morbidity and stone clearance rates that compare favorably with percutaneous nephrolithotripsy.

Adult↗
PubMed2006

Factors influencing intraoral removal of submandibular calculi.

OBJECTIVES: To assess the effectiveness of intraoral removal of submandibular calculi based on several factors that may influence the results of surgery. STUDY DESIGN AND SETTING: We retrospectively reviewed 172 patients who underwent intraoral removal of submandibular sialolithiasis. Results of surgery were divided into complete removal, partial removal, and failure. The effect of location, palpability, size, and presence of infection of the calculi on the results was estimated. RESULTS: Univariate analysis showed that palpability and presence of infection were statistically significant factors affecting intraoral removal. Palpability was the only significant factor after multivariate analysis. Twelve of 13 patients with recurrent calculi underwent repeat intraoral removal successfully. CONCLUSIONS: The palpability of submandibular calculi is the most important factor influencing their successful intraoral removal. SIGNIFICANCE: Intraoral removal can be performed successfully regardless of location, size, presence of infection, or recurrence of calculi, if the calculi are palpable.

Adolescent↗
PubMed2006

Bladder calculi: did the clinical picture change?

OBJECTIVES: Recent improvements in socioeconomic conditions have changed the clinical picture of urinary stones, including bladder calculi. With the ongoing changes in these predisposing factors, it is possible that the clinical picture of bladder calculi will show additional changes. Nevertheless, few contemporary series of bladder calculi in published English reports have addressed these issues. METHODS: We retrospectively reviewed the records of 328 patients who underwent surgical therapy for bladder calculi at our institution from January 1995 to June 2005. RESULTS: Acute urinary retention was the most common presenting symptom (n = 221, 67%). Patients who presented with urinary retention were younger (37 versus 48 years, P <0.001), had a greater incidence of recent renal colic (40% versus 19%, P <0.01), and had a lower incidence of bladder outlet obstruction (14% versus 37%, P <0.001) compared with the nonretention group. However, previous stone passage did not influence the probability of presenting with urinary retention. Small bladder stones were associated with a greater likelihood of presenting with urinary retention. The retention group had greater incidence of stones less than 1 cm in diameter compared with the nonretention group (72% versus 39%, P <0.001). Finally, calcium oxalate was found in 78% of patients with bladder calculi. CONCLUSIONS: Acute urinary retention was the main mode of presentation in patients with bladder calculi. Younger age, a history of recent renal colic, and smaller stones appeared to increase the likelihood for patients to present with urinary retention.

Adult↗
PubMed2001

Determination of pyrophosphate in renal calculi and urine by means of an enzymatic method.

An enzymatic method for the determination of pyrophosphate which has been applied to renal calculi is described. The method involves the preconcentration of pyrophosphate using anionic exchange resin and development of the enzymatic reactions with the pyrophosphate retained on the resin. The study of calculi treatment according to calculi composition is also reported. The pyrophosphate content was dependent on the calculi composition. The highest amount of pyrophosphate was found in hydroxyapatite calculi (of the order of 10 microg/g), struvite and oxalate calculi showed a lower amount (the order was 2.5 and 4.5 microg/g, respectively) and was not detected in uric acid and cystine stones. The method was also successfully applied to the determination of pyrophosphate in human urine. For urinary pyrophosphate determination, a modification based on a clean-up of urine using activated carbon has been proposed. Pyrophosphate in human urine was of the order of 4 mg l(-1).

Algorithms↗
PubMed1997

Ureteroscopic management of ureteral calculi: electrohydraulic versus holmium:YAG lithotripsy.

PURPOSE: This study compared electrohydraulic and holmium:YAG lithotripsy for ureteral calculi. MATERIALS AND METHODS: Two cohorts of consecutive patients with ureteral calculi treated with ureteroscopic electrohydraulic or holmium:YAG lithotripsy were retrospectively compared. Electrohydraulic lithotripsy was done using a 1.9F fiber at energy settings between 50 and 100 v. Holmium:YAG lithotripsy was done using a 365 microm. fiber at energy settings of 0.6 to 1.5 J. RESULTS: A total of 23 and 47 consecutive patients underwent electrohydraulic and holmium:YAG lithotripsy, respectively. For preoperative calculi less than 15 mm. mean stone size plus or minus standard deviation was 9 +/- 3 versus 9 +/- 3 mm. (p = 0.5), mean operative time was 72 +/- 21 versus 102 +/- 38 minutes (p = 0.004), stone-free rate at the end of ureteroscopy was 65 versus 97 (p < 0.01) and 3-month stone-free rate was 94 versus 97% (p = 0.4) for electrohydraulic versus holmium:YAG lithotripsy. For preoperative calculi 15 mm. or greater stone size was 19 +/- 5 versus 19 +/- 4 mm. (p = 0.9), operative time was 159 +/- 61 versus 108 +/- 27 minutes (p = 0.01), stone-free rate at the end of ureteroscopy was 33 versus 87% (p = 0.001) and 3-month stone-free rate was 67 versus 100% (p = 0.02). Complications were not significantly different in either comparison. CONCLUSIONS: The overall likelihood that a patient would be rendered stone-free at ureteroscopy and 3 months after ureteroscopy favored holmium:YAG over electrohydraulic lithotripsy. For ureteral calculi less than 15 mm. electrohydraulic lithotripsy was more rapid than the holmium:YAG procedure but for ureteral calculi 15 mm. or greater the holmium:YAG technique was more rapid than electrohydraulic lithotripsy. The outcomes differences may have resulted from the different mechanisms of electrohydraulic and holmium:YAG lithotripsy.

Adult↗
PubMed1999

Retrograde ureteropyeloscopy for lower pole caliceal calculi.

PURPOSE: Contemporary treatment of lower pole renal calculi includes extracorporeal shock wave lithotripsy, percutaneous nephrostolithotomy and retrograde ureteropyeloscopy. Success rates for shock wave lithotripsy are reduced in this setting, especially for stones greater than 1 cm. and/or in patients with anatomical variants. Percutaneous treatment, although effective, subjects the patient to increased morbidity. We studied the safety and efficacy of retrograde ureteroscopic treatment of lower pole intrarenal calculi. MATERIALS AND METHODS: We evaluated 90 stone burdens localized to the lower pole and treated with a small diameter, actively deflectable, flexible ureteropyeloscope and a 200 micron holmium laser fiber. Stone burdens were classified as group 1--10 or less, group 2--11 to 20 and group 3--greater than 20 mm. in largest diameter. Patients with calculi less than 2.5 cm. were treated as outpatients unless concurrent medical conditions required hospitalization. Larger stones and partial staghorn calculi (group 3) frequently required 2-stage endoscopic procedures with retrograde intrarenal irrigation for 36 hours to clear debris. An acceptable immediate surgical outcome was defined as complete fragmentation reducing the stone burden to dust and 2 mm. or less fragments. Success was defined as clear imaging (that is stone-free) on renal sonography with minimum 3-month followup. Extreme anatomical variants, including a long infundibulum, acute infundibulopelvic angle and a dilated collecting system, were noted and correlated with surgical failures. RESULTS: Endoscopic access and complete stone fragmentation were achieved in 94, 95 and 45% of groups 1, 2 and 3, respectively. After a second treatment the success rate increased to 82% in group 3, with an overall rate of 91%. Of the 19 surgical failures 8 were secondary to inability to access the lower pole and 11 were secondary to inability to render the patient stone-free. In 2 of the 19 cases infundibular strictures hindered ureteroscopic access. In addition, of the anatomical variants a long lower pole infundibulum was the most statistically significant predictor of failure. Mean operative time ranged from 38 minutes for small to 126 for the largest calculi. There were no major complications. Overall stone-free rates with minimum 3-month followup were 82, 71 and 65% in groups 1, 2 and 3, respectively, and 88, 77 and 81%, respectively, in patients with an acceptable initial surgical outcome (that is excluding those with access failures from analysis). CONCLUSIONS: Retrograde ureteropyeloscopy is a safe and effective surgical treatment for lower pole intrarenal calculi.

Adolescent↗
PubMed1991

Treatment of ureteral calculi with extracorporeal shock wave lithotripsy using the Lithostar device.

Shock wave requirements for fragmentation and the ultimate outcome after extracorporeal shock wave lithotripsy (ESWL) with the Lithostar device were analyzed in 107 renal units with solitary ureteral calculi. In situ treatment was done in 54 stones without prior manipulation and in 15 after failure of endoscopic manipulation. A total of 25 ureteral calculi was treated after bypass with a ureteral catheter or stent and 13 after push back to the pelvicaliceal system. Shock wave requirement for fragmentation was significantly higher for calculi of 101 to 400 mm. X mm. when compared with the requirement for smaller calculi. Shock wave requirement was also significantly higher for patients with similar sized stones treated in the prone compared to the supine position. The average number of shock waves required for disintegration was not significantly different among in situ or any of the manipulation categories of similar sized stone populations. Over-all satisfactory clearance was achieved in 77.5% of the treated ureteral calculi. Clearance status was unaffected by size up to 400 mm. X mm. and the position of the patient during treatment (prone or supine). Clearance of ureteral stones treated in situ without prior manipulation (76.5%) was numerically inferior, although statistically insignificant, to that for successfully manipulated calculi (bypassed 88% and pushed back 92.3%) but it was significantly better than the outcome obtained after failed manipulation (46.2%). ESWL with the Lithostar device is a successful mode of treatment within the entire ureteral length, and a vigorous attempt at push back before lithotripsy is unnecessary.

Humans↗
PubMed1986

An algorithm for the management of ureteral calculi.

We evaluated 158 patients with ureteral calculi (28 impacted in the ureteropelvic junction, 42 in the upper, 29 middle and 36 lower third of the ureter, and 23 in the intramural tunnel) treated by extracorporeal shock wave lithotripsy, percutaneous ultrasonic lithotripsy, ureteroscopic methods, chemolysis or surgery. Of the patients 92.5 per cent were treated successfully by endourological methods. Twelve patients (7.5 per cent) required an operation. Extracorporeal shock wave lithotripsy was successful in 61 per cent of the patients without placement of a ureteral stent and in 100 per cent in whom stent placement or stone dislodgement was successful. Ureteroscopic removal was successful in 52 of 56 patients with lower third and intravesical tunnel ureteral calculi. An algorithm for ureteral calculi management is developed, which emphasizes stent bypass and extracorporeal shock wave lithotripsy for upper third or ureteropelvic junction calculi, ureteroscopic removal or stent bypass with extracorporeal shock wave lithotripsy for middle third calculi, and ureteroscopic techniques for lower third and intramural tunnel calculi. Percutaneous ultrasonic lithotripsy, chemolysis and surgery are recommended as complementary methods.

Algorithms↗
PubMed2000

Nitinol stone retrieval-assisted ureteroscopic management of lower pole renal calculi.

OBJECTIVES: Current ureteroscopic intracorporeal lithotripsy devices and stone retrieval technology allow for the treatment of calculi located throughout the intrarenal collecting system. Difficulty accessing lower pole calculi, especially when the holmium laser fiber is used, is often encountered. We retrospectively reviewed our experience with cases in which lower pole renal calculi were ureteroscopically managed by holmium laser fragmentation, either in situ or by first displacing the stone into a less dependent position with the aid of a nitinol stone retrieval device. METHODS: Thirty-four patients (36 renal units) underwent ureteroscopic treatment of lower pole renal calculi between April 1998 and November 1999. Lower pole stones less than 20 mm were primarily treated by ureteroscopic means in patients who were obese, in patients who had a bleeding diathesis, in patients with stones resistant to shock wave lithotripsy, and in patients with complicated intrarenal anatomy, or as a salvage procedure after failed shock wave lithotripsy. Lower pole calculi were fragmented with a 200-micrometer holmium laser fiber by way of a 7.5F flexible ureteroscope. For those patients in whom the laser fiber reduced the ureteroscopic deflection, precluding re-entry into the lower pole calix, a 3.2F nitinol basket or a 2.6F nitinol grasper was used to displace the lower pole calculus into a more favorable position, allowing easier fragmentation. RESULTS: In 26 renal units, routine in situ holmium laser fragmentation was successfully performed. In the remaining 10 renal units, a nitinol device was passed into the lower pole, through the ureteroscope, for stone displacement. Only a minimal loss of deflection was seen. Irrigation was significantly reduced by the 3.2F nitinol basket, but improved with the use of the 2.6F nitinol grasper. This factor did not impede stone retrieval in any of the patients. At 3 months, 85% of patients were stone free by intravenous urography or computed tomography. CONCLUSIONS: Ureteroscopic management of lower pole calculi is a reasonable alternative to shock wave lithotripsy or percutaneous nephrolithotomy in patients with low-volume stone disease. If the stone cannot be fragmented in situ, nitinol basket or grasper retrieval, through a fully deflected ureteroscope, allows one to reposition the stone into a less dependent position, thus facilitating stone fragmentation.

Adult↗
PubMed2002

Ureteroscopic treatment of renal calculi in morbidly obese patients: a stone-matched comparison.

OBJECTIVES: To report a matched comparison of morbidly obese (MO) patients and normal weight (NW) patients who underwent ureteroscopic (URS) treatment of renal calculi. Shock wave lithotripsy and percutaneous nephrostolithotomy may be precluded in MO patients, and URS treatment offers a minimally invasive alternative. METHODS: We retrospectively reviewed the charts of patients who underwent URS at our institution between 1997 and 2000. Fifty-four patients underwent URS treatment solely for renal calculi. Sixteen MO patients underwent 18 procedures. Thirty-eight NW patients, who underwent 39 procedures, were matched to the MO patients by stone location and size. Stones were categorized by location and size, less than 10 mm or 10 mm or greater. The factors and outcomes assessed were stone length, operative time, presence of a ureteral stent, success, and complications. RESULTS: The overall success rate was 83% (15 of 18 procedures) for MO patients and 67% (26 of 39 procedures) for NW patients, but this difference was not significant (P = 0.23). The difference in the success rate for renal calculi 10 mm or greater (100% versus 38%) approached significance (P = 0.09). This may be related to other distinctions between the groups. URS treatment was often a salvage therapy in the NW group after other modalities failed. No significant differences were found between the other outcomes. CONCLUSIONS: URS treatment of renal calculi when matched for location and size is as successful and no more morbid in MO than in NW patients. URS treatment of renal calculi is a safe and effective first-line treatment for renal calculi in MO patients.

Body Mass Index↗
PubMed2003

Laterality of symptomatic cystine calculi.

OBJECTIVES: To evaluate patterns of laterality in cystine stone formation to determine whether phenotypic expression of this genetic disease is distributed equally in each kidney. Cystinuria is a genetic defect that may result in the formation of recurrent cystine calculi. Significant nongenetic factors may play a role in the manifestation of this disease. METHODS: Thirty-four patients seen in the Stone Center at the University of California, San Francisco were retrospectively evaluated for treatments and patterns of symptomatic stone formation between 1989 and 2002. A conservative surgical regimen and routine radiographic examinations were used. Treatments were used as a surrogate for development of symptomatic calculi. RESULTS: The mean age at last follow-up was 38.2 years. The mean age at presentation was 18 years. The 34 patients underwent a total of 249 procedures, averaging 7.3 procedures per patient. Of the 34 patients, 29% required only unilateral surgery and formed unilateral symptomatic calculi exclusively (P <0.0001) during their lifetime. Of the 10 patients with unilateral stone formation, 2 (20%) were female and 8 (80%) were male. Of the 24 patients with bilateral stone formation, 12 (50%) were female and 12 (50%) were male. Of the 10 patients with unilateral stone formation, 6 developed left-sided calculi and 4 developed right-sided calculi. CONCLUSIONS: A subset of one third of patients with cystine stone formation will develop unilateral calculi exclusively during their lifetime. Understanding why the contralateral side did not form stones may provide insight into novel prophylactic regimens. The etiology of symptomatic unilateral cystine nephrolithiasis is unknown, but anatomic and external triggers should be considered.

Adult↗
PubMed1994

Treatment of urinary calculi in a porcine and canine model using the Browne Pneumatic Impactor.

OBJECTIVES: To define the safety and efficacy of a pneumatically driven, mechanical lithotriptor using nitinol probes through semirigid and actively deflectable, flexible fiberoptic endoscopes. METHODS: The Browne Pneumatic Impactor (BPI) uses standard compressed air to drive a nitinol wire along its long axis onto a calculus, fragmenting it. Bench top and in vivo experiments were designed to explore variables, including the effects of various nitinol probe tip designs, outer diameters, excursion distances, and sheathing materials as well as the efficiency of fragmentation with active endoscope deflection. In vivo experiments in two animal models (porcine and canine) were performed using small diameter, fiberoptic semirigid, and actively deflectable, flexible ureteroscopes. Surgically placed calculi were fragmented with the BPI and representative tissue was obtained immediately and up to 2 weeks postoperatively to define histologic changes. A panel of human urinary calculi was chosen for their relative difficulty in fragmentation with other modalities. RESULTS: Calculi, including pure calcium oxalate monohydrate, brushite, cystine, and triamterene, were fragmented with the BPI used through both semirigid and actively deflectable, flexible endoscopes. A rounded tip design and excursions of 1 mm fragmented calculi most efficiently with minimal histologic reaction. Retrograde stone migration before fragmentation was noted in dilated upper urinary tracts. This was prevented by first entrapping the calculus within a standard basket. Ureteral calculi were fragmented with the nitinol probes deflected up to 45 degrees by the flexible endoscope. With increased active deflection, the efficiency of fragmentation decreased. CONCLUSIONS: The BPI represents a safe, thermal-free endoscopic lithotrite able to fragment the hardest calculi through semirigid and flexible ureteroscopes.

Alloys↗
PubMed1998

Recurrent bilateral renal calculi in a tetraplegic patient.

An 18-year-old male developed C-5 complete tetraplegia following a motor-cycle accident in May 1975. The neuropathic bladder was managed by an indwelling urethral catheter. He developed recurrent episodes of urinary infection with Proteus species. In September 1975, an X-ray of the abdomen revealed small calculi in both the kidneys. In July 1976, he underwent transurethral resection of the bladder neck and division of the external urethral sphincter; subsequently, he was put on a penile sheath drainage. He continued to suffer from repeated episodes of urinary tract infection with Proteus, Providencia, and Pseudomonas species, and he was treated with antibiotics. In 1980, intravenous urography (IVU) showed two large stones in the left kidney with marked caliectasis. The IVU performed in 1984 showed an increase in the size of the calculi in the left kidney which was grossly hydronephrotic. There were clusters of small calculi in the right kidney. The left renal calculi were treated by percutaneous lithotripsy in two sessions. In 1988, an X-ray of the abdomen revealed staghorn calculus in the right kidney and recurrence of stones in the left kidney. The staghorn calculus in the right kidney was treated by percutaneous nephrostolithotomy in two sessions. In 1991, he was admitted with acute urinary infection. IVU showed a stone in the pelviureteric junction with no excretion of contrast in the left kidney. Percutaneous nephrostomy drainage was established followed by left percutaneous nephrostolithotomy. In 1992, he was found to retain large amount of urine in the bladder; subsequently, his mother was taught to perform regular intermittent catheterisations. In 1995, he was admitted with acute urine infection. Abdominal X-ray revealed recurrence of large stones in both kidneys. With multiple sessions of Extracorporeal Shockwave Lithotripsy (ESWL), about 80% clearance was achieved on the left side. Right staghorn renal stone awaits treatment. This case shows that recurrent urinary infection in spinal cord injury patients is a predisposing factor for renal lithiasis. These patients require annual urological evaluation. Urinary tract calculi, if detected, should be dealt with promptly to prevent renal damage due to urinary obstruction and urosepsis. Renal calculi can be treated effectively and safely by ESWL in spinal cord injury patients, thus avoiding the need for an invasive procedure. It is essential to achieve low-pressure, adequate emptying of the urinary bladder in patients with spinal cord injury in order to prevent recurrent urinary infection and its sequelae. Social issues involved in the care of a tetraplegic patient play a vital role in the implementation of ideal medical treatment and need to be addressed promptly to avoid any compromise in the quality of medical care.

Adolescent↗
PubMed2002

Significance and diagnostic accuracy of renal calculi found by ultrasonography in patients with asymptomatic microscopic hematuria.

BACKGROUND: The purpose of the present study was to evaluate the clinical significance and the accuracy of the diagnosis of renal calculi incidentally found by ultrasonography (US). METHODS: A total of 906 subjects (639 men and 267 women) aged 18-78 years were referred for asymptomatic microscopic hematuria. Of these, 743 patients who underwent US were studied. RESULTS: Hyperechogenic spots in the central echo complex suggesting renal calculi were noted in 195 patients (21.5%). The occurrence of hyperechogenic spots was higher in patients with 20 or more urinary red blood cells per high-power field (chi(2) = 4.896, P = 0.0269) and in men than in women (chi(2) = 7.101, P = 0.0077), but it was lowest in patients who were 29 years old or younger. Of these 195 patients, who were followed up for 1-161 months (average: 33.5 months), 24 patients (12.3%) needed urological management. Extracorporeal shockwave lithotripsy was carried out in eight patients, transureteral lithotripsy was carried out in three patients, spontaneous passage occurred in 11 patients and medication for hyperuricemia was initiated in two patients (1%). Among the patients in whom hyperechogenic spots were found on the kidney by US but calculi were not visible on abdominal plain radiographs, 39 patients underwent computed tomography. Of them, 31 patients were confirmed to have renal calculi. CONCLUSION: The obtained results suggest that US is an effective and reliable means of detecting renal calculi in patients with asymptomatic microscopic hematuria, and in facilitating prompt urological intervention or predicting the natural course of renal calculi.

Adult↗
PubMed2000

Current management of calculi in horseshoe kidneys.

OBJECTIVES: To assess treatment options for calculi in horseshoe kidneys and the impact of extracorporeal shockwave lithotripsy (ESWL) on the management of renal stones. MATERIAL AND METHODS: From June 1971 to January 1998, 52 patients with horseshoe kidneys and calculi received treatment at our Urologic Stone Unit. There were 40 men (77%) and 12 women (23%). Average patient age was 41 years (range: 10-70 years). Clinical onset, treatment received and outcome were evaluated retrospectively. A successful outcome was defined as a patient without residual calculi or with fragments <0.4 cm in size. RESULTS: Clinical onset was mainly low back pain in 37 patients (71%). Eighty-nine stones were treated, i.e. an average of 1.7 treatments per patient. Before the ESWL era (May 1987), we performed two heminephrectomies, 16 pyelolithotomies, 12 pyelolithotomies combined with ureteropyeloplasty and one percutaneous nephrolithotomy. Since the advent of ESWL, seven pyelolithotomies and three pyelolithotomies combined with ureteropyloplasty have been done. ESWL was used to treat 48 calculi. In three cases the patient was placed in the prone position due to difficulties in stone focusing. In 37 cases (77%) patients were either rendered stone-free or had residual fragments <0.4 cm in size. Urinary diversion for obstruction was carried out in two cases (4%). CONCLUSIONS: At present ESWL is the first-choice treatment for calculi in horseshoe kidneys. It involves no significant focusing difficulties and is associated with a low incidence of obstructive complications. Open surgery is indicated in cases of stone-related pyeloureteral stenosis and in the presence of calculi >2-2.5 cm in size.

Adolescent↗
PubMed2002

Segmentation of renal calculi in ultrasound images.

An algorithm proposed by Sridhar and Kumaravel is extended to include a framework for the detection of renal calculi. Calculi occur due to abnormal collection of certain chemicals like oxalate, phosphate and uric acid. These calculi can be present in the kidney, ureter or urinary bladder. Performance analysis is done to a set of five known algorithms using parameters such as success rate in calculi detection, border error metric and time. The framework is constructed by combining the best algorithm based on the performance analysis and a procedure to validate the detected calculi using the shadow it casts in ultrasound images. Ultrasound images of 37 patients are used for testing the algorithm. The detected calculi based on the framework match those determined by expert clinicians in more than 95% of the cases.

Algorithms↗
PubMed1999

Percutaneous suprapubic cystolithotripsy for treatment of large bladder calculi.

BACKGROUND AND PURPOSE: The treatment options available for managing bladder calculi include transurethral cystolithotripsy, open cystolithotomy, and shockwave lithotripsy. For larger calculi, transurethral treatment can be time consuming, and the manipulation has the potential to cause urethral injury. Percutaneous suprapubic cystolithotripsy represents another treatment option for bladder calculi which is effective and minimally invasive. PATIENTS AND METHODS: Fifteen patients had bladder calculi treated with percutaneous cystolithotripsy over a 3-year period. The mean stone size was 39 mm (range 10-64 mm). Stones were single in seven patients and multiple in eight patients. The indications for cystolithotripsy were stone size >3 cm, multiple stones >1 cm, and inability to perform transurethral cystolithotripsy because of patient anatomy. Percutaneous suprapubic cystolithotripsy was done through either a 30F or a 36F cystotomy tract. Fragmentation and removal was performed with a 26F rigid nephroscope and the pneumatic Swiss Lithoclast. Suprapubic and urethral catheters were placed postoperatively in all patients. RESULTS: Each patient was cleared of the stone burden with a single procedure, and there were no major complications. The mean duration of suprapubic catheterization was 2.6 (range 1-5) days. CONCLUSION: Percutaneous suprapubic cystolithotripsy is an effective and safe technique for treating large bladder calculi. It is minimally invasive, avoids urethral injury, and, in combination with the pneumatic Swiss Lithoclast, can be used to fragment and remove large and hard bladder calculi.

Aged↗
PubMed2006

Impacted upper-ureteral calculi >1 cm: blind access and totally tubeless percutaneous antegrade removal or retrograde approach?

PURPOSE: To compare blind access and totally tubeless percutaneous antegrade removal and pneumatic transurethral ureterolithotripsy for the management of impacted upper-ureteral calculi >1 cm. PATIENTS AND METHODS: Seventy patients (41 male, 29 female) with impacted upper-ureteral calculi >1 cm were selected in randomized order for pneumatic transurethral ureterolithotripsy (35 patients) or blind access and totally tubeless percutaneous nephrolithotomy (PCNL) (35 patients). Ultrasonography and intravenous urography were performed for all patients before surgery. After operation, plain films and ultrasonography were done. RESULTS: In the PCNL group, blind access was achieved from the lumbar notch area in all 35 patients, but in 3 patients, the exposure was not optimal for approaching the ureteropelvic junction (UPJ). So we injected contrast material into the collecting system, and, under fluoroscopic control, another access was achieved. In 33 patients (94.3%), intact removal of the stones was performed. In the other two patients, we fragmented the stones with the Swiss Lithoclast by an antegrade approach. The success rate thus was 100%. The mean operative time was 38 minutes (range 25-48 minutes). In the transurethral lithotripsy group, 12 stones (34.2%) migrated upward to the pelvis of kidney, and 5 stones (14.2%) fragmented incompletely. In these cases, a double- J stent was inserted, and SWL was performed. In follow-up, plain films and ultrasonography showed complete clearance in these patients. Eighteen calculi (51.4%) fragmented completely with the Lithoclast. The mean operative time in this group was 34 minutes (range 20-58 minutes). CONCLUSION: In the presence of moderate to severe hydronephrosis, blind access and totally tubeless PCNL is an effective option for large, impacted upper-ureteral calculi. Flexible ureteroscopy with laser lithotripsy is expensive and not readily available. Pneumatic transurethral ureterolithotripsy has a back-pressure effect and pushes back the calculi to the kidney. Thus, this procedure does not have satisfactory results in the management of these calculi.

Adolescent↗