Stone disease.

Imaging studies used for the detection and characterization of urinary tract calculi are presented in this article. Comparisons of traditional imaging studies are made with noncontrast helical CT scanning, the most recent addition to stone imaging. Imaging findings for noncontrast helical CT and an approach to dealing with various combinations of CT studies are also presented.

Interventional uroradiologic procedures performed using gadodiamide as an alternative to iodinated contrast material.

Three patients with either a history of severe allergic reactions to iodinated contrast or marked renal insufficiency underwent interventional uroradiologic procedures using full-strength gadodiamide (Gd) as a contrast agent in place of iodinated contrast material. The procedures were percutaneous access for nephrostolithotomy, antegrade pyelography with placement of a nephroureteral stent, and a diagnostic nephrostogram with exchange of a nephroureteral stent. Gd was visualized fluoroscopically and produced satisfactory digital radiographs without allergic reaction or worsening renal function. Gd can be useful in guiding interventional uroradiologic procedures when iodinated contrast material is contraindicated.

Activated protein C resistance and lupus anticoagulant in pregnancy.

Thrombophilias, both inherited and acquired, have been reported to be associated with thromboembolic events and severe obstetric complications. This case report examines the case of a patient with two thrombophilias, activated protein C resistance secondary to Factor V Leiden mutation and lupus anticoagulant.

A comparison of ureteroscopy to in situ extracorporeal shock wave lithotripsy for the treatment of distal ureteral calculi.

PURPOSE: The optimal treatment for distal ureteral calculi remains controversial. Most urologists offer extracorporeal shock wave lithotripsy (ESWL) or ureteroscopy for stones that require intervention. We present data from our institution on these modalities since 1990. MATERIALS AND METHODS: We treated 187 distal ureteral calculi with ESWL (91 cases) on a Dornier HM3 or MFL 5000 lithotriptor, or with ureteroscopy (96 cases) using basket extraction with or without pulsed dye laser lithotripsy. RESULTS: Fragmentation and stone-free rates for ESWL were 80 and 73%, respectively, with no complications. For ureteroscopy the stone-free rate was 95% with a 5.2% short-term complication rate and no long-term complications. CONCLUSIONS: At our institution ureteroscopy is more efficacious than ESWL for the treatment of distal ureteral calculi.

Sonographic detection of ureteral calculi in patients with normal excretory urography.

We report 3 cases of nonobstructing distal ureteral calculi diagnosed by sonography in which excretory urography was normal. In each case sonography was performed because of high clinical suspicion for a ureteral stone. In 2 patients a stone was impacted at an edematous ureteral orifice. All 3 patients subsequently passed the stone spontaneously. A high resolution ultrasound examination should be performed on patients with a history suggestive of ureteral calculus despite a normal excretory urogram.

Comparison of symptom characteristics of indwelling ureteral catheters.

The signs and symptoms produced by 4 different types of 7F double pigtail catheters, including Cook polyurethane pigtail stent, Surgitek Silitek Uropass, Cook C-Flex and Van-Tec Soft stent, were analyzed prospectively. The stents were placed in 45 men and 28 women ranging in age from 23 to 72 years old. A total of 44 catheters had a suture attached to the bladder end of the catheter, which exited from the urethral meatus to facilitate removal. The remaining 29 catheters had no suture attached. Symptoms were evaluated at 2 and 6 days after insertion and 1 week following removal of the catheter, and included urinary frequency, nocturia, hematuria, flank pain, suprapubic pain, dysuria and pain on removal of the catheter. Frequency and nocturia were evaluated in minutes, pain was graded on a subjective scale of 0 (no pain) to 10 (severe pain), and dysuria and hematuria were assessed qualitatively. There were no significant differences among the 4 types of catheters in terms of frequency, nocturia, hematuria, flank pain, suprapubic pain and dysuria. In addition, there was no significant difference in urinary symptoms between catheters with and without a suture at either 2 or 6 days after insertion nor was there any difference in pain on removal of catheters with (mean 3.9) and without (mean 5.0) suture. We found that catheter composition and use of suture to facilitate removal did not significantly affect patient morbidity.

Computerized tomographic appearance of renal cysts after extracorporeal shock wave lithotripsy.

We identified cysts in five kidneys of four patients who had lithotripsy. Three of these kidneys were evaluated with CT scans the day before and the day after lithotripsy and showed no change. The other two kidneys were studied by CT only after extracorporeal shock wave lithotripsy; hemorrhage was shown in one and cyst wall thickening in the other.

Use of double-pigtail stents in extracorporeal shock wave lithotripsy.

Double-pigtail stents are placed commonly in patients before extracorporeal shock wave lithotripsy to prevent ureteral obstruction from steinstrasse. The use of double-pigtail stents in lithotripsy patients with a moderate stone burden was studied in a prospective randomized trial. Patients with unilateral renal stone(s) with at least 1 diameter between 7 and 25 mm. were eligible for the study. Fifty patients were randomized to a control or stented group. Double-pigtail stents with an attached suture were placed immediately before extracorporeal shock wave lithotripsy in the stented group. Stents were removed by the patients 1 week after lithotripsy. A survey on pain and associated symptoms was completed by patients at 1 and 14 days after treatment. There was no statistical difference in flank or abdominal pain, nausea, vomiting, temperature or use of analgesics at 1 and 14 days after extracorporeal shock wave lithotripsy in the control and stented groups. All patients in the stented groups complained of side effects attributable to the stent including urinary frequency and urgency, bladder pain, hematuria and flank pain with urination. Of 25 patients with stents 7 (27%) had early removal because of severe irritation, early migration or accidental removal. Among the patients with follow-up x-rays 1 month after treatment 17 of 21 (81%) in the control group and 12 of 19 (63%) in the stented group showed no evidence of remaining stones. The use of double-pigtail stents is not beneficial in patients with a moderate stone burden. Double-pigtail stents are associated with considerable patient discomfort but no decrease in symptomatic ureteral obstruction or final stone eradication rate.

In situ lithotripsy of ureteral calculi: review of 261 cases.

The authors report 261 cases of single ureteral calculi treated with in situ lithotripsy after retrograde manipulations had failed. Previous reports have indicated that extracorporeal lithotripsy of impacted ureteral calculi has not been highly successful. Two hundred five of the calculi were located in the proximal ureter, above the sacroiliac joint; 27 were in the presacral ureter, overlying the bony pelvis; and 29 were in the juxtavesicular ureter, below the inferior border of the sacroiliac joint. Retrograde ureteral catheters were in place during lithotripsy for 215 calculi. Two hundred fifty-four (97%) calculi were successfully treated with lithotripsy and, when necessary, with additional postlithotripsy radiologic and urologic interventions. Seven (3%) calculi were not successfully fragmented. Nephrostomy was performed in 13 (5%) patients. Retrograde ureteral catheters were not found to enhance calculus fragmentation. In situ lithotripsy of ureteral calculi has been shown to be feasible as an alternative to ureterolithotomy when retrograde manipulation has failed.

Dornier extracorporeal shock-wave lithotripsy for ureteral stones.

Most investigators think that ESWL is the preferred method for treating calculi in the upper ureter--that segment proximal to the superior margin of the iliac crest. Ureteroscopic manipulation, percutaneous antegrade manipulation, and open ureterolithotomy are secondary choices. The treatment of calculi in the lower ureter--that segment between the upper border of the iliac crest and the ureterovesical junction--is somewhat controversial. Most urologists favor ureteroscopic manipulation: small stones can be extracted, while larger stones can be fragmented with ultrasonic, electrohydraulic, or even laser lithotripsy. However, manipulation in the presacral ureter is more difficult than in the juxtavesicular ureter, and all stones are not amenable to ureteroscopic management. Our experience at the University of Virginia led us to use ESWL for lower ureteral stones when ureteroscopic manipulation fails or cannot safely be accomplished or when patients refuse cystoscopy. Juxtavesicular stones are treated with a minor modification (sitting position) of standard supine ESWL, whereas presacral stones are treated with prone ESWL.

Extracorporeal shock wave lithotripsy in the prone position: treatment of stones in the distal ureter or anomalous kidney.

A total of 15 patients underwent ESWL using the Dornier HM3 lithotriptor with the patient in the prone position. The stones were in the distal ureter over the sacroiliac joint in 10 patients, 8 of whom had undergone unsuccessful ureteroscopic manipulation. Two patients had horseshoe kidneys with stones that were too anterior to permit accurate targeting with the patient in the standard supine position. One patient had a solitary stone in a pelvic kidney and 1 had an obstructing ureteropelvic junction stone in a crossed ectopic kidney. The final patient had a reconstructed lower urinary tract with a stone at 1 of the ureterointestinal anastomoses. Excellent pulverization was achieved in all patients after only 1 prone ESWL treatment. One patient required temporary percutaneous nephrostomy after ESWL and 1 may require retrograde manipulation of fragments at the ureterovesical junction. No patient had melena, and other than temporary ileus in 1 patient who had concurrent supine ESWL of renal calculi, no gastrointestinal complications were seen. All but 1 patient were free of stones 1 month after prone ESWL. Prone ESWL prevents blockage of shock wave energy by the bony pelvis, because the shock waves enter anteriorly and exit posteriorly. ESWL with the patient in the prone position is a safe and effective treatment of calculi in the distal ureter or anomalous kidney.

Ureteral stone manipulation before extracorporeal shock wave lithotripsy.

We randomized 75 patients with solitary ureteral calculi that could not be dislodged by ureteral catheterization to receive instillation of saline, 2 per cent lidocaine viscous solution or dilute surgical lubricant before repeat stone manipulation with ureteral catheters. Of the stones irrigated with saline 76 per cent were returned to the pelvis along with 60 per cent of the lidocaine group and 48 per cent of the surgical lubricant treated stones. There was no statistical significance among the 3 groups. The success rates for upper, mid and lower ureteral stones were 80, 54 and 30 per cent, respectively. Of stones 0.5 cm. or less and between 0.6 and 1.0 cm. 77 and 72 per cent, respectively, were manipulated successfully but only 38 per cent of the stones larger than 1.0 cm. could be dislodged. Extracorporeal shock wave lithotripsy was successful in treating pelvic and ureteral stones, although higher kilovolt settings and additional shocks were necessary to fragment the ureteral stones completely. Percutaneous nephrostomy or ureteral meatotomy was required in 10 per cent of the patients with impacted ureteral stones following in situ extracorporeal shock wave lithotripsy but in only 4 per cent of the patients with stones successfully returned to the pelvis. Of the ureteral stones 17 per cent were treated with repeat extracorporeal shock wave lithotripsy. No patient with pelvic stones required repeat treatment. Retrograde manipulation of ureteral stones is an effective adjunctive procedure before extracorporeal shock wave lithotripsy.

The role of radiology in extracorporeal shock wave therapy.

Extracorporeal shock wave lithotripsy was used for the treatment of 1,252 kidneys and ureters with calculi during a 10-month period at the authors' medical center. Before lithotripsy was performed, excretory urography, radiography, renography, computed tomography, and ultrasound studies were done, when necessary, to locate the calculi. Nine calculi in five kidneys could not be fragmented with lithotripsy. Of 895 patients with calculi less than 2.5 cm in diameter, only 13 (1.5%) required interventional procedures to clear the calculi, whereas of 161 patients with calculi greater than or equal to 2.5 cm, 36 (22.4%) required nephrostomies. A column of calculous debris in the mid and distal portions of the ureter (steinstrasse) was seen in 171 instances (13.6%) after lithotripsy; 62% required interventions. The most common intervention required for successful lithotripsy was retrograde ureteral catheterization. Evaluation and treatment of patients with urolithiasis were largely dependent on radiography and excretory urography.

Initial experience with extracorporeal shock wave lithotripsy in children.

The clinical experience is presented of 4 United States centers at which extracorporeal shock wave lithotripsy was used for the treatment of renal calculi in 38 children 12 months to 16 years old. Patient characteristics, treatment specifics and followup data are detailed. Complete fragmentation of calculi was obtained in 97 per cent of those treated, with a 5 per cent complication rate. This experience demonstrates that with proper safeguards, extracorporeal shock wave lithotripsy can be performed safely and effectively in the pediatric population.

Transport of citrate across renal brush border membrane: effects of dietary acid and alkali loading.

Dietary acid or alkali loading was given to rats by providing 150 mM NH4Cl or 150 mM NaHCO3 in place of drinking water for 6 days; control animals received 150 mM NaCl. After 6 days, the citrate clearance was 0.04 +/- 0.01 ml/min (mean +/- SE) in the acid-loaded group, 0.9 +/- 0.1 ml/min in the control group, and 2.5 +/- 0.2 ml/min in the alkali-loaded group. At the end of the experiment, the rats were killed, and the Na+ gradient-dependent (Nao+ greater than Nai+) citrate uptake (pmol/mg protein) was measured in brush border membrane (BBM) vesicles prepared from each group. At 0.3 min, the [14C]citrate uptake was 198 +/- 8 pmol/mg protein (mean +/- SE) in the acid-loaded group, 94 +/- 16 pmol/mg protein in the control group, and 94 +/- 13 pmol/mg protein in the alkali-loaded group. The rate of Na+-independent (NaCl in medium replaced by KCl) [14C]-citrate uptake by BBM vesicles was the same for acid-loaded, control, and alkali-loaded animals. Thus, the increased capacity of the proximal tubular BBM to transport citrate from the tubular lumen into the cell interior may be an important factor that contributes to decreased urinary citrate in the presence of metabolic acidosis induced by chronic dietary acid loading.