Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CALCULI”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1986

Multiple percutaneous access routes to multiple calculi, calculi in caliceal diverticula, and staghorn calculi.

For expeditious removal of multiple calculi from certain locations in the pyelocaliceal system, the use of multiple percutaneous entry routes is advocated. The accessibility of different regions of the pyelocaliceal system from different percutaneous entry sites was mapped out after experience with the percutaneous removal of 87 solitary and 37 multiple renal calculi. A technique allowing limited access to calculi in caliceal diverticula and hydrocalices distal to stenotic infundibula was used, along with a technique for percutaneous infundibuloplasty, which is necessary to ensure drainage of such obstructed calices or caliceal diverticula after percutaneous lithotripsy. In 34 of 37 patients with multiple or staghorn calculi, all calculi were eventually removed by these methods. The use of multiple entry routes did not increase the risk of reduced renal function. Moreover, improved drainage through the resultant multiple nephrostomy tubes and transinfundibular stents has reduced the incidence of postoperative septicemia.

Humans↗
PubMed2001

Abdominal radiography after CT reveals urinary calculi: a method to predict usefulness of abdominal radiography on the basis of size and CT attenuation of calculi.

OBJECTIVE: The purpose of this study was to determine if the radiographic visibility of urinary tract calculi could be predicted on the basis of CT features. MATERIALS AND METHODS: The images of 26 patients whose urinary tract calculi were revealed on unenhanced helical CT and who also underwent digital abdominal radiography were retrospectively reviewed. CT features studied included size and CT attenuation of the calculi. These CT findings were correlated with the ability to detect the same calculi with radiography. RESULTS: Forty-nine urinary tract calculi were detected with unenhanced helical CT in 26 patients. Twenty-six (53%) calculi were visible on radiography. Most (79%) calculi larger than 5 mm were detectable with radiography (p < 0.01). One (8%) of 13 calculi with CT attenuation below 200 H was detectable on radiographs. Ninety-five percent (21/22) of calculi with CT attenuation exceeding 300 H were visible on radiographs (p < 0.0001). The one remaining calculus was obscured by overlying anatomy. CONCLUSION: Radiographic surveillance of urinary tract calculi detected with CT may not be useful if the calculi have a CT attenuation below 200 H. Most calculi larger than 5 mm and nearly all calculi with a CT attenuation exceeding 300 H can be seen on abdominal radiographs.

Adult↗
PubMed1985

[The residual calculi in conservative operation for renal calculi].

One hundred and three kidneys with calculi in 100 patients, were treated by conservative renal surgery from Jan., 1980 to Dec., 1982. The operative technique consisted of pyelolithotomy, extended pyelolithotomy, dismembered pyelolithotomy, nephrolithotomy (bivalve or anatrophic nephrolithotomy) partial nephrectomy and pyelo-nephrolithotomy. Intraoperative X-ray and coagulum lithotomy were employed when pyelolithotomy was performed. Thirty-five residual calculi in 20 kidneys were observed on postoperative X-ray film. The rate of residual calculi was 19.4%. Factors causing residual calculi, were analysed on these 103 kidneys. The factors were as follows; the shape of calculi: staghorn calculus with multiple small calculi, the shape of the renal collecting system: narrow pelvis with narrow caliceal neck and dilatated calices, and the operative technique: nephrolithotomy. These results suggested that it would be necessary to minimize residual calculi when performing nephrolithotomy.

Adolescent↗
PubMed1979

Scanning electron microscopy of human prostatic corpora amylacea and corpora calculi, and prostatic calculi.

Ultrastructural studies of human prostatic corpora amylacea and corpora calculi, and prostatic calculi were conducted in order to delineate their etiology and pathogenesis. Scanning electron microscopy was employed in conjunction with histology and transmission electron microscopy in the study of prostatic tissues and concretions obtained from 21 individuals. Results confirmed that desquamated acinar cells contribute to the formation and growth of corpora amylacea. A variation in density of the matrix of the matrix of the corpora produces a laminated structure. The deposition of hydroxyapatite crystallites in corpora amylacea leads to the formation of corpora calculi. Further growth and mineralization of corpora calculi lead to the development of the more clinically significant prostatic calculi. Small spherical aggregates (from 0.5 to 5 micron in diameter) of hydroxyapatite crystallites are a prevalent constituent of the corpora and prostatic calculi. Similar spherical aggregates of hydroxyapatite crystallites have also been identified in urinary calculi and other pathologic tissues suggesting similar mechanisms of mineral precipitation.

Calculi↗
PubMed1995

The case for primary endoscopic management of upper urinary tract calculi: II. Cost and outcome assessment of 112 primary ureteral calculi.

OBJECTIVES: To compare extracorporeal shock-wave lithotripsy (ESWL) with endoscopic lithotripsy to establish the more efficacious and cost-effective treatment for ureteral calculi. METHODS: The records of 112 patients with primary ureteral calculi treated at one center with either ESWL or endoscopic lithotripsy were retrospectively reviewed. Follow-up data at 1 and 3 months were obtained in all patients. Success was defined as complete clearance of a stone burden in the endoscopy group. In the ESWL group patients with a residual, asymptomatic 2-mm fragment were also considered successful treatments. The number of auxiliary procedures, retreatments, postoperative office visits, and imaging studies required before a patient was considered stone free was defined. The impact of these variables on global costs was carefully reviewed. RESULTS: Patients with ureteral calculi primarily treated with ESWL or ureteroscopic lithotripsy had stone-free rates after a single session of 45% versus 95% at 1-month follow-up, and 62% versus 97% at 3-month follow-up. Retreatment and auxiliary procedure rates were significantly higher in the ESWL group (31% versus 3%). The mean number of postoperative visits and imaging studies until a patient was stone free was also higher in the ESWL group (2.07 versus 1.13). Operative treatment costs were similar for both modalities, but overall costs weighed heavily against ESWL. CONCLUSIONS: ESWL remains the treatment of choice for moderately sized, uncomplicated renal calculi. In skilled hands, ureteroscopic lithotripsy is by far the most expeditious and cost-effective means of clearing a ureteral stone burden.

Costs and Cost Analysis↗
PubMed1997

Three-dimensional CT-scan reconstruction of renal calculi. A new tool for mapping-out staghorn calculi and follow-up of radiolucent stones.

OBJECTIVES: The development of CT scanners (CT scan) with continuous rapid spiral acquisition now allows three-dimensional reconstructions of mobile organs such as kidneys. The aim of this study was to appreciate the merits of this new technique in the field of renal lithiasis. METHOD: This non-invasive technique was applied in 27 renal calculi (23 staghorn and 4 radiolucent stones). The acquisition does not require any injection of contrast material. Reconstruction was carried out by three-dimensional (3D) shaded surface display. RESULTS: 3D reconstruction of calculi permits a precise study of the shape of the stone, and of the number, size and direction of its branches. Therefore, it allows for better planning of the PCNL (number of ports, per-operative pelvi-caliceal exploration ...). Large radiolucent calculi are clearly defined with 3DS, facilitating the follow-up under medical treatment. CONCLUSION: 3D CT scan reconstruction is a noninvasive, cost-effective method which offers high quality 3D images of renal calculi. These results should spur the more widespread use of this technique.

Cost-Benefit Analysis↗
PubMed1997

[Urinary calculi in children: contribution of anamnesis, biological exploration and physical analysis of calculi to the etiological diagnosis].

BACKGROUND: It is always of importance to define the cause of urinary calculi disease in children to prevent recurrence and possible impairing of renal function. Nevertheless, etiology is not always easy to prove and must be deduced from both clinical and biological arguments. PATIENTS AND METHODS: The aim of this prospective study including 39 Tunisian children with urinary stones was to identify etiology and stone risk factors and detail the part of clinical and biological data and results of physical analysis of stones in determining the cause of the stone. RESULTS: In 31 cases among 39, clinical and biological data were not sufficient to identify clearly the stone etiology. When considering the structure and stone composition, the cause of the stone could be determined in 97.4% of the cases. An inherited disease was found responsible for the stone in 11 children, urinary tract infection in 13 cases, idiopathic hypercalciuria in nine cases and a nutritional deficiency disease in seven cases. In one case, polycystic kidney disease with metabolic risk factors could explain the stone process. No precise etiology was found in one case. Among infection stones, struvite stones could be related to urea-splitting bacteria while other calculi, containing whitlockite and protein matrix could be related to other micro-organisms. Earlier severe chronic diarrhoea episodes were noted in six among seven children presenting stones with a nucleus mainly composed of ammonium urate. CONCLUSION: Clinical data, biological data from both urine and blood of the patients and also the structure and composition of the stones are needed to identify the cause of urinary calculi. Such a procedure could provide the stone etiology in most cases.

Adolescent↗
PubMed1991

[Extracorporeal lithotripsy of ureteral calculi using the Dormier HM3 device. A series of 176 calculi].

In a series gathered over 5 years (November 1984 to November 1989), we have treated 356 patients with ureteral lithiasis. Out of these, 170 (134 men and 36 women) were treated with extracorporeal shock-wave lithotrity with a Dornier HM3 system, in situ and as a first intention. The calculi (176 stones) were regularly distributed along the ureter: their location was subpyelic in 44 cases, lumboiliac in 59, upper pelvic in 42 and lower pelvic in 32. The average diameter of the calculi was 10 mm for subpyelic stones and 8 mm for the others. A preliminary urine drainage was required for 24 calculi causing acute obstructive pyelonephritis (32 ureteral drains surrounding the stone, and 2 percutaneous nephrostomies). Radioscopic localization required intravenous pyelography during lithotrity in 52 cases (30%). On radiographs without preparation taken the next day, 170 stones were regarded as fragmented (96%). After some time the 6 patients whose calculus had not been fragmented underwent another treatment (4 ureterotomies and 2 ureteroscopies). Five patients had an additional treatment because of a painful and/or febrile episode (3 drain insertions and 2 ureterotomies) and 2 patients required a second session of lithotrity because fragmentation was not sufficient; 4 patients were lost to follow-up. A total of 153 patients (90%) got rid of their fragments, 146 during the first months and the remaining 7 before the sixth month. No severe complication was noted. Besides the 5 patients who had required additional treatment, 11 patients suffering from pain and/or fever had a medical treatment. These treatments lead us to proposing first-intention "in situ" extracorporeal shock wave lithotrity for all ureteral lithiases requiring a treatment.

Adolescent↗
PubMed1987

Fictitious calculi and human calculi with foreign nuclei.

The correlative approach employing polarized light microscopy, x-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, selected area electron diffraction and energy dispersive x-ray microanalysis proves to be very useful in identifying fictitious calculi and genuine human calculi with foreign body nuclei. The common artifacts as reported in the literature and observed also by us were minerals, vegetable and plant seeds, cereals, sand grains and sea shell fragments. Two interesting cases involving foreign body nuclei have been reported: one urinary calculus containing a piece of plastic-coated titanium foil in the center; one nasal calculus with a nut as a nucleus. Another common cause for foreign body nucleation is iatrogenic: intrauterine devices, catheters, suture materials and even surgical staples have been reported in the literature to be potent nidi for calculus formation. These cases remind us of the important fact that our body fluids are supersaturated with respect to calcium phosphates and occasionally to other compounds. Hydroxyapatite crystals are readily nucleated by foreign bodies. Whitlockite is involved if the fluid Mg/Ca ratio is in a suitable range, brushite if the fluid is acidic and struvite if there is urea-splitting infection. In urine and other fluids, calcium oxalate and uric acid crystals contribute to the calculus growth.

Calculi↗
PubMed1976

A contribution to the formation mechanism of calcium oxalate urinary calculi. III. On the role of magnesium in the formation of oxalate calculi.

The influence of magnesium in vitro on the precipitation of calcium oxalate was investigated. Even at maximum physiological magnesium concentrations a litholytic effect could not be observed, but the retardation of the calcium oxalate crystallization caused by magnesium might be decisive for a reduction in calculi formation. The enlargement of the calcium oxalate crystals and aggregates caused by the retardation of crystallization, however, should be regarded as a contraindicating factor for Mg therapy in oxalate calculous disease. It is safe to say that high magnesium concentrations prevent the conversion into Whewellite of the calcium oxalate calculi substance primarily formed as Weddellite.

Calcium↗
PubMed1994

Effects of stents on lithotripsy of ureteral calculi: treatment results with 18,825 calculi using the Lithostar lithotriptor.

Between November 14, 1988 and August 1, 1993, 18,825 ureteral calculi were treated in the United States using 25 different mobile and 2 fixed base Siemens Lithostar lithotriptors. Lithotripsy was performed by 1,012 urologists using the modified Puigvert technique. The overall stone-free rate was 83.8% with a retreatment rate of 10.8%. The stone-free rate varied from 85.8% with stones of 10 mm. or smaller to 67.9% for stones larger than 20 mm. A ureteral stent or catheter was placed before lithotripsy in 19.3% of all treatments and 80.7% had in situ treatment without instrumentation. For calculi of any size, the use of ureteral stents or catheters had no effect on treatment outcome at any ureteral location.

Ambulatory Care↗
PubMed1978

Cytological changes due to urinary calculi: a consideration of the relationship between calculi and the development of urothelial carcinoma.

Urinary calculi can induce urothelial cellular abnormalities comparable with those of malignancy; this was found in 11 out of 62 lithiasis cases. Severe cellular changes, comparable with those of carcinoma in situ, may be seen in the epithelium adjacent to a calculus. Squamous metaplasia was frequently observed in cases with staghorn stones in the renal pelvis. The abrasive effect of the calculus may result in many multinucleated cells in the sediment. When the calculi are removed the cytological atypia and the observed multinucleation disappeared, and none of these 62 patients developed urothelial carcinoma. A possible relationship was found between a long-term clinical history of lithiasis and the development of cancer of the upper urinary tract in a study of 92 cases of carcinoma of the ureter and renal pelvis.

Cytodiagnosis↗
PubMed1990

[Exclusive piezoelectric lithotripsy in the treatment of calculi larger than 30 mm (partial or complete coralliform, pyelic calculi)].

Thirty patients with partial or total staghorn stones or calculi larger than 30 mm were treated by piezoelectric lithotripsy (PEL) monotherapy using an EDAP LT-01 lithotripter with ultrasound guidance. Nineteen of these patients had pelvic stones; the other 11 had partial (9) or total (2) staghorn stones. All patients first underwent an initial lithotripsy session. No anesthesia or IV sedation was required in any case. If stone fragmentation was achieved during this first session, a double-J stent was inserted before the second lithotripsy session. Prior to the first session, 18 of 30 patients had sterile urine cultures; 12 of 30 presented major distension of the excretory tract. Results were analyzed to determine the factors influencing the outcome of this therapy. Three months after the first session, patients were considered cured if their stones had completely disappeared according to plain abdominal films (14 of 30, 46%). In seven patients (23.3%) fragmentation had occurred but residual fragments remained (1 to 3 fragments less than or equal to 4 mm). No fragmentation was obtained after the first session in nine patients (30.7%) (1 total staghorn stone, 8 pelvic stones). The mean number of treatment sessions was five (range, 1 to 15). Complications occurred in only 10% of patients (3 of 30): two steinstrassen and one acute pyelonephritis. Eighty-three percent of patients without major excretory tract distension and 55% of patients whose initial urine culture was sterile achieved a stone-free state. Therefore the best indications for PEL monotherapy for calculi larger than 30 mm are pelvic stones and partial staghorn stones and no major excretory tract dilatation in patients with sterile initial urine cultures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1976

A contribution to the formation mechanism of calcium oxalate urinary calculi. II. In vitro experiments concerning the theory of the formation of Whewellite and Weddellite urinary calculi.

In vitro investigations of the formation of Whewellite or Weddellite are described. By means of different precipitation models the influence of cationic minerals on the formation of Weddellite could be observed. The possible conversion of Weddellite into Whewellite in vivo is demonstrated by in vitro experiments. A theory of the formation of Weddellite or Whewellite urinary calculi is developed on the basis of the results obtained.

Calcium↗