Definitive Stone Research Articles

Management of obstructive calcular anuria with acute renal failure in children less than 4 years in age: A protocol for initial urinary drainage in relation to planned definitive stone management

ObjectivesTo describe and evaluate our protocol for management of children ≤4years old with obstructive calcular anuria (OCA) and acute renal failure (ARF) to improve selection of initial urinary drainage (ID) method and to facilitate subsequent definitive stone management (DSM) as studies discussing this special group of patients are still few. Patients and methodsPatients with a contraindication to any method of ID were excluded. Decision (percutaneous nephrostomy (PCN) or double J (JJ) stent) was based on degree of hydronephrosis and planned DSM. We used 4.8–5Fr JJ or 6–8Fr PCN under general anesthesia and fluoroscopic guidance. According to our protocol, JJ is inserted for hydronephrosis ≤ grade 1. When the hydronephrosis is >grade 1, patients with radiolucent stones were treated by JJ whatever the site of the stone. When the stones were radiopaque, PCN was reserved for stones in a solitary functioning kidney and bilateral ureteric stones prepared for subsequent bilateral ureterolithotomy (or stone prepared for ureterolithotomy in a solitary kidney). After normalization of renal functions, DSM was staged attacking only one side before discharge. Both sides were cleared at the same session in cases with bilateral ureterolithotomy. Renal or ureteric stones suitable for SWL in a solitary kidney were treated with percutaneous nephrolithotripsy (PNL) or ureteroscopy. This was followed also in patients with bilateral stones suitable for SWL by clearing one side using ureteroscopy or PNL before discharge. Open surgery (OS) was reserved for cases with failed ureteroscopy or PNL, for ureteric stones >2.5 cm in size or very large volume complex renal stones. Stone free rate (SFR) was evaluated by CT. Our protocol was evaluated as regard recovery of renal functions, complications, and number of interventions to clear stones. ResultsThis study included 62 boys and 22 girls presented with anuria for 1–4 days. JJ and PCN were inserted in 105 and 30 ureterorenal units (URU), respectively. Creatinine returns normal within 72 h. JJ insertion formed a part of DSM in 78/159 (49%) URU (stones prepared for extracorporeal shockwave lithotripsy or oral chemolytic dissolution therapy). PCN was the ideal tract for subsequent PNL in 11/159 (6.9%) URU. Accordingly, ID participated by 55.97% in DSM. Both operative and imaging times were slightly longer with PCN than JJ. There was no statistically significant difference in the insertion success or mean period to return to normal chemistry. Complications of both methods were mild and without any significant difference. Endourologic procedures constituted the majority of our interventions. Open surgical and endoscopic interventions for clearance of stones (including ID, treatment conversion and 2ry procedures) were done once for 25 patients, twice for 43 patients while it was needed three times for 16 patients. Total number of interventions was 149 procedures. SFR was 94%. ConclusionOur protocol ensures adequate ID with minimal complications when using our selection criteria in children ≤4 years in age with OCA and ARF. It also minimizes number of subsequent procedures to clear stones. Complications and success in insertion and drainage were equivalent in PCN and JJ groups.

556 Selection criteria for initial urinary drainage in relation to definitive stone management in obstructive calcular anuria with acute renal failure in children less than 4 years in age

556 Selection criteria for initial urinary drainage in relation to definitive stone management in obstructive calcular anuria with acute renal failure in children less than 4 years in age

Does Baseline Radiography of the Kidneys, Ureters, and Bladder Help Facilitate Stone Management in Patients Presenting to the Emergency Department with Renal Colic?

A baseline kidneys, ureters, and bladder (KUB) radiograph, at the time of computed tomography (CT) for ureteral stones, might aid interpretation of future KUBs. The CT scout radiograph might render the baseline KUB redundant, however. We sought to assess the diagnostic utility of baseline KUB for patients with ureteral stones. Patients with ureteral stones were retrospectively identified. All had a baseline KUB in addition to CT and were reassessed after 4 to 60 days with KUB. Each patient's imaging was randomized 1:1 into either "KUB&CT" or "CT" groups. Three urologists independently assessed the imaging: CT (with scout film) and baseline KUB in the KUB&CT group, but only the CT (not KUB) in the CT group. Definitive stone assessment on follow-up KUB was defined as all three reviewers answering either Yes or No (not Indeterminate) to the question of stone passage or migration. Of 154 stones, the mean diameter was 4.8 ± 2.1 mm, density was 914 ± 300 Hounsfield units (HU), with 54.4% in the distal ureter. Stone visibility was 60.4% on KUB vs 43.5% on scout film (P<0.001). Scout film visibility favored the CT group (52.7 vs 35.0%, P = 0.027). After adjusting for body mass index, skin-to-stone distance, size, density, and location, definitive assessment rates were higher in the KUB&CT group (P = 0.047). When reviewers reassessed the CT group using the baseline KUB, they were able to do so definitively in an additional 16 (21.6%, P<0.001). Definitive assessments were associated with higher rates of stone visibility on scout film (86.1 vs 21.1%, P<0.001), KUB (86.1 vs 50.0%, P<0.001), and larger (6.0 vs 3.7 mm, P<0.001), denser stones (1046 vs 802 HU, P<0.001). The addition of a baseline KUB to the CT scout film improves the ability of urologists to determine stone outcome when following patients with KUB imaging and might reduce the subsequent need for additional imaging.

Emergent ureteric stent vs percutaneous nephrostomy for obstructive urolithiasis with sepsis: patterns of use and outcomes from a 15‐year experience

To characterize the use of emergent JJ ureteric stent placement and percutaneous nephrostomy (PCN) for patients with obstructive urolithiasis with sepsis, and to determine whether outcomes differ between the two treatment methods. A total of 130 patients with obstructive urolithiasis and systemic inflammatory response syndrome criteria were identified retrospectively from a single health system database from 1995 to 2011. Primary outcomes included stone-related and clinical variables which predicted the use of each treatment method. Secondary outcomes included the length of hospital stay, risk of intensive care unit (ICU) admission, and surgical approach used for definitive stone management. The overall rate of failed procedures was 2.3% (3/130), with one in-hospital death (0.8%). Patients treated with PCN had larger stones (10 vs 7 mm, P = 0.031), and were more acutely ill (acute physiology, age, chronic health evaluation [APACHE] II scores of 15 vs 11, P = 0.036) than those treated with JJ stent placement. Patients treated with PCN were more likely to require ICU admission (odds ratio: 3.23, 95% confidence interval [CI]: 1.24-8.41, P = 0.016), and demonstrated longer length of hospital stay (β: 0.47, 95% CI: 0.20-0.74, P = 0.001), even when adjusting for age, APACHE II score, and Charlson Comorbidity Index score. After resolution of sepsis, patients treated with PCN were more likely to be treated definitively with a percutaneous approach, while patients treated with JJ stent placement were more likely to be treated ureteroscopically. Both JJ stent placement and PCN drainage appear effective. Patients with larger stones and who are more acutely ill are more likely to be treated with PCN. Additional randomized clinical trials of adequate power are warranted to define the optimum management of these often complex cases.

2260 AN INSTITUTIONAL REVIEW OF ANESTHETIC TIMES FOR URINARY STONES IN PREGNANT WOMEN

INTRODUCTION AND OBJECTIVES: Management options for urolithiasis during pregnancy include trial of passage, temporizing ureteral stent or nephrostomy tube, and definitive treatment with ureteroscopy. Prior research suggests children can suffer adverse long term effects from exposure to medications used for general anesthesia. Specifically, anesthesia exposure greater than two hours or greater than two separate anesthesia exposures prior to the age of four years has been associated with the development of learning disabilities. The goal of this study is to compare the potential anesthesia risk to the fetus when temporizing stents are placed compared to definitive management with ureteroscopy. METHODS: We retrospectively reviewed the records of patients diagnosed with urolithiasis during pregnancy who underwent surgical intervention from 1997 to 2012. Patients were evaluated for a confirmed stone event, defined as a stone visualized on imaging or at surgery, along with management strategy including duration and frequency of anesthetic events. RESULTS: We identified 26 women with urolithiasis during pregnancy who met our inclusion criteria, of which 15 (58%) were managed with stents and 11 (42%) underwent ureteroscopic intervention. In the stent group 6 (40%) required multiple stent exchanges for a mean of 1.47 (range 1-3) anesthetic events and median anesthetic time of 70 minutes (range 29-208 min). Seven (47%) of the women managed with ureteral stent exchange were induced prior to term due to inability to tolerate the stent. Overall the ureteroscopy group had a mean of 1.18 anesthetic events (range 1-2) and 80 minutes (range 37-126 min) of anesthetic exposure. Two (18%) required two procedures either for infection or narrow ureter. None were induced early for pain. Comparing the two groups, there was no significant difference in number of events (p 0.208) or total anesthetic time (p 0.503). CONCLUSIONS: Ureteroscopic intervention appears safe and effective in treating acute stone events with equivalent if not less anesthetic exposure to the fetus compared to temporizing ureteral stents. Furthermore, early induction of labor due to pain is not a concern with ureteroscopy, as it has been shown to be with ureteral stenting. Our study provides further support to the role of definitive stone management instead of temporizing measures during pregnancy.

Office-based Ureteral Stent Placement Under Local Anesthesia for Obstructing Stones Is Safe and Efficacious

To evaluate the outcomes of urgent ureteral stent placement under local anesthesia (LA) with those placed under general anesthesia (GA) for obstructing stones. After institutional review board approval, ureteral stents placed from January 2007 to July 2011 at our institution were reviewed. Only primary stent placement for obstructing renal or ureteral calculi was included in the present analysis. Data were evaluated for 2 groups: GA and LA. The primary outcomes were demographics, interval from presentation to stent insertion, interval from stent insertion to stone removal, success and complication rates, and secondary outcomes were costs per encounter. A total of 119 primary stent insertion procedures in 110 unique patients were assessed; 73 (GA) and 46 (LA). No differences were found in the mean age or sex between the 2 groups. Both GA and LA groups were stented within 12 hours of presentation, at 58% and 54%, respectively (P = .69); and the interval from stent insertion to stone removal was similar in both groups (mean 33 days and 35 days in the GA and LA groups, respectively, P = .79). No significant differences were found in the failure to place the stent between the GA and LA groups (1.3% vs 8.7%, respectively, P = .07). No complications related to stent placement occurred in either group. The average cost per encounter was nearly 4 times greater in the GA group. Urgent ureteral stent placement for obstructing stones can be safely and effectively performed under LA in the office. Although avoiding GA and reducing costs, this approach did not prolong the interval to definitive stone management.

Is there a place for ESWL in the treatment of complicated proximal ureteral stones?

Although recently the minimal invasive urological and endourological methods have been substantially improved, concerns remain about the optimal management of proximal ureteral stones. Even the European Association of Urology Guidelines are not fully clear and leave the choice of treatment method to the urologist's discretion. Both extracorporeal shock wave lithotripsy (ESWL) and ureteroscopy (URS) are accepted methods of the proximal ureteral stones management. ESWL is very often used as a first–line procedure because of its minimal invasiveness. It is proper for ureteral stones in all locations, but especially suitable for proximal (lumbar) localization because URS is considered more difficult in the upper part of the ureter. Authors of the paper published in this issue of Central European Journal of Urology have discussed the impact of a double–J stent for the results of ESWL in ureteral lumbar stones [1]. A lot of predictors have been reported to influence ESWL outcome in the management of ureteral calculi [2]. One of them is a double–J stent. As the authors have pointed, there are conflicting opinions on the ESWL effects in the management of ureteral stones in pre–stented patients. There is a quite popular theory that the indwelling stent creates expansion space thus facilitating effects of ESWL. On the other hand many authors stress that a stent can absorb energy of shock waves, impede their propagation and energy transmission thus lowering fragmentation rate. Also, while some suggest that catheters aid fragments passage by passive dilatation of the ureter [3] others point out that double–J stents can cause uretheral oedema, irritation and diminished peristalsis delaying clearance [4]. Results reported by Pettenati et al. show that presence of a double–J stent adversely affect the results of ESWL for stones >8 mm. The main limitation of this study is its retrospective design. However, some prospective studies have also reported that pre–stenting before ESWL does not improve the procedure results. In the recent prospective randomized trial stenting prior ESWL provided no additional advantage over in–situ ESWL. There was no statistical significant difference in stone–free rates between stented and non–stented patients with upper impacted ureteral stones measuring ≤2 cm treated with ESWL (90% vs. 86.7% respectively; p = 0.346) [5]. In another prospective randomized study pre–stenting limited stone–free rates in the ESWL management 4 to 10 mm ureteral stones (68.6% vs. 83.7% for stented and non–stented groups respectively; p = 0.026) and was responsible for higher post–ESWL morbidity and lower quality of live [6]. Therefore routine stenting before ESWL for ureteral lithiasis is not recommended, but in case of complicated lithiasis (sepsis, acute obstructive pyelonephritis, renal insufficiency, severe pain) urgent decompression with a double J stent is often necessary before implementation of definitive treatment. What should be the next step in the management of ureteral stones after recovery from sepsis or any other emergency case? Should we perform ESWL or rather ureteroscopy as a definitive treatment following the double J stent placement? The choice is controversial. Decision should be individual for each patient with a ureteral stone, especially if complicating factors co–exist. However, in my opinion Pettenati's study and other publications support the use of URS as a preferred first–line procedure in complicated lumbar ureteral stones previously managed with a double J stent. Pre–stenting makes ureteroscopy easier, improves stone–free rates and reduces complications risk [7]. With uncomplicated URS there is a higher probability of definitive stone clearance with just one procedure and the stent can be removed earlier. That is an important advantage as lower urinary tract symptoms caused by indwelling stent are noticed in up to 80% of patients. Stent–related complaints interfere with daily activities and are responsible for quality of life deterioration [3]. Patients treated with ESWL are usually not immediately stone–free and very often there is a need for repeated ESWL sessions or other additional procedures which delay definitive treatment, thus lowering the patient's quality of live and increasing costs.

Challenges on percutaneous nephrolithotomy in pregnancy: Supine position approach through ultrasound guidance

Urolithiasis in pregnancy represents a major diagnostic and therapeutic challenge to the obstetrician, urologist, radiologist and anesthetist. It is a cause of major concern, considering the potential adverse effects of radiation exposure and of any invasive surgical procedure and anesthesia on the mother and fetus. Fortunately, with conservative management, 70-80% of symptomatic calculi pass spontaneously with no sequel. However, fever, infection, uncontrolled pain and progressive hydronephrosis are indications for surgical intervention when retrograde placements of a ureteral stent or a percutaneous nephrostomy tube are the most traditional options. The recent technological advances in stone fragmentation devices and the administration of safe anesthesia have forced clinicians to embark on more definitive stone management techniques in pregnancy. Ureteroscopy is considered the first definitive treatment of obstructive ureteral calculi during all trimesters of pregnancy, but also has limitations. Although generally avoided during pregnancy, percutaneous nephrolithotomy can be a good treatment choice in selected patients.

Beyond ESWL: new concepts for definitive stone removal

Every 10th German will form upper urinary tract calculi during live time ad every fourth of them will suffer from a recurrence [1]. It is therefore not surprising that urinary stones account for up to 20% of all urological cases. Therefore, every urologist has to be familiar with urinary stone disease. During the last three decades, interventional stone treatment made an enormous shift from open surgery to today’s minimal-invasive procedures. Extracorporal shock wave lithotripsy (SWL) virtually stopped all other techniques only shortly after percutaneous nephrolithotomy (PNL) has been introduced. However, the limitations of SWL such as large stones, hard stone compositions and the lower renal pole became evident over the years. Improvements in endoscopic techniques and skills let to preferential use of ureteroscopy (URS) and, again, percutaneous techniques.

Ten years of Swedish experience with intraductal electrohydraulic lithotripsy and laser lithotripsy for the treatment of difficult bile duct stones: an effective and safe option for octogenarians

Endoscopic procedures using electrohydraulic lithotripsy (EHL) or intraductal laser lithotripsy (ILL) are the methods of choice for managing difficult common bile duct (CBD) stones. This retrospective study examined 10 years of Swedish experience using a mother-baby endoscopic system to assist in the fragmentation of CBD stones by EHL and ILL. Between 1995 and 2006, 44 patients with a median age of 80 years underwent EHL or ILL at two Swedish centers after conventional endoscopic fragmentation of CBD stones had failed. Long-term follow-up assessment was conducted for 9 to 126 months (median, 53 months). Final stone clearance after EHL or ILL treatment with or without additional conventional endoscopic retrograde cholangiopancreatography (ERCP) was achieved for 34 (77%) of 44 patients. The results for 10 patients (23%) were defined as failures. Complete or partial stone fragmentation and definitive duct clearance were achieved in one session for 23 patients (52%). A second EHL or ILL attempt made in five cases of primary failure led to definitive stone clearance in three cases. Two patients experienced perioperative complications (stone basket impaction). Mild post-ERCP pancreatitis occurred for one patient and cholangitis for two patients. During long-term follow-up evaluation, recurrent CBD stones were found in one patient. Peroral endoscopic EHL or ILL, under direct cholangioscopic visualization by a mother-baby endoscopic system, is an effective treatment for difficult CBD stones. The technique can be used safely even in frail and elderly patients. However, several endoscopic attempts may be required before final stone clearance is achieved. The vast majority of patients may be expected to remain symptom free for a prolonged period.

Intraoperative Cholangiography in Modern Surgical Practice

Background/Aims: The aim of this study was to assess the practice of performing intraoperative cholangiography (IOC) during laparoscopic cholecystectomy in a busy teaching hospital. Methods: Data were obtained from a surgical database for patients who underwent laparoscopic cholecystectomy between January 2000 and December 2003. The findings of IOC and follow-up were analysed. Results: 1,651 patients were included in the study. Of the 745 patients (45.1%) who underwent IOC, this was normal in 586 patients and abnormal in 68 patients. Of these 68 patients, 4 underwent immediate conversion to open common bile duct exploration. 33 patients underwent endoscopic retrograde cholangiopancreatography and 31 patients were observed. During a median follow-up period of 920 days (range 371–1,821), 5 of the 745 patients had retained stones. Two patients re-presented after a failed IOC while 5 of the 906 patients from the non-cholangiogram group returned with stones. Of the 1,651 patients, definite stones were identified in 1.5% patients. Conclusion: When the surgeon deemed that IOC was not required, very few subsequent problems were encountered. An observational policy with monitoring of the liver function tests may be appropriate to avoid unnecessary invasive interventions in patients with an abnormal IOC.

Concurrent urinary tract infection and stone disease: pathogenesis, diagnosis and management

Urinary tract stones and urinary tract infection are strongly associated. Infection is implicated as the cause of stones in about 15% of stone formers, and the development of infection can complicate the management of pre-existing stones. Left untreated, both situations can result in loss of kidney function, and can, on occasion, be life threatening. The underlying pathophysiology of infection stones is generally well understood, but factors dictating why a particular individual should be affected are less clear, although obstruction is a uniformly recognized risk factor. Surgery is the mainstay of treatment for infection calculi: stone clearance is the goal and a range of minimally invasive treatments is available. Systemic sepsis remains the most serious complication of treatment, and, although rare, still occurs despite antibiotic prophylaxis. Once the stone and the causative infection have been removed, various strategies can be employed to minimize the risk of recurrence. When infection complicates pre-existing stone disease, the primary aim of management is to treat the infective episode and delay definitive stone management until the infection has cleared. In such cases where obstruction is also present, prompt drainage of the affected kidney is likely to prevent permanent renal damage, and may be life saving.

The Imaging Evaluation of Cholelithiasis in the Obese Patient—Ultrasound vs CT Cholecystography: Our Experience with the Bariatric Surgery Population

The purpose of this study was to compare computed tomography (CT) cholecystography and ultrasound for gallstone detection in preoperative bariatric surgery patients. The study included 16 asymptomatic prebariatric surgery patients. On the same day, each patient underwent abdominal CT 4 h after IV cholecystograffin injection, and gallbladder ultrasound. CT and ultrasounds were reviewed by two independent, blinded radiologists, and scored as follows: no gallstones, possible gallstones, definite gallstones, indeterminate. CT and ultrasound results were compared. Ultrasound detected definite gallstones in three patients, possible gallstones in one patient, and no gallstones in ten patients. Two scans were considered indeterminate. CT cholecystography detected definite gallstones in six patients, possible gallstones in zero patients, and no gallstones in nine patients, and was indeterminate in one patient. All three patients with gallstones seen sonographically had definite gallstones on CT. The patient with possible gallstones detected sonographically had definite stones detected at CT. One of the two patients with indeterminate ultrasounds had gallstones detected at CT. The other patient had both studies indeterminate. One patient with no gallstones sonographically had definite gallstones at CT. No patients with a negative CT had gallstones seen on ultrasound. Nine patients had no gallstones on either modality. CT cholecystography is more sensitive and specific for the detection of gallstones in the obese population. CT cholecystography should be considered in place of ultrasound in the preoperative workup of these patients.

Modern management of renal colic

AbstractRenal stones are often asymptomatic, having been detected incidentally on imaging for other disorders. Renal stones can, however, cause severe pain when they move or obstruct the drainage of urine. Topics considered in this review of modern management of acute renal colic include clinical, laboratory and radiological diagnosis, analgesia, emergency scenarios and definitive stone management, including ureteroscopy and extracorporeal shockwave lithotripsy. Copyright © 2008 Wiley Interface Ltd

The Mirizzi Syndrome: Multidisciplinary Management Promotes Optimal Outcomes

The Mirizzi syndrome (MS) is a rare cause of obstructive jaundice produced by the impaction of a gallstone either in the cystic duct or in the gallbladder, resulting in stenosis of the extrahepatic bile duct and, in severe cases, direct cholecystocholedochal fistula formation. Sixteen patients were treated for MS in our center over the 12-year period 1993–2005 for a prevalence of 0.35% of all cholecystectomies performed. One patient was diagnosed only at the time of cholecystectomy. The other 15 patients presented with laboratory and imaging findings consistent with choledocholithiasis and underwent preoperative endoscopic retrograde cholangiopancreatography, which established the diagnosis in all but one patient. All patients underwent cholecystectomy. An initial laparoscopic approach was attempted in 14 patients, of whom 11 were converted to open procedures. MS was recognized operatively in 15 patients with definitive stone extraction and relief of obstruction in 13 patients. T-tubes were placed in 10 patients and 1 patient required a choledochoduodenostomy. Two patients required postoperative laser lithotripsy via a T-tube tract to clear their stones; and in another patient, MS was detected and treated via postoperative endoscopic retrograde cholangiopancreatography (ERCP). MS remains a serious diagnostic and therapeutic challenge for endoscopists and biliary surgeons.

Accuracy of two impression techniques with angulated implants

Accurate recording of implant locations is required so that definitive restorations are properly supported and do not place additional stress on the implants. Angulated implants may result in inaccurate impressions, and the impression technique may affect the accuracy of the definitive cast. The purpose of this study was to determine the effect the combined interaction of impression technique, implant angulation, and implant number has on the accuracy of implant definitive casts. One definitive stone cast was fabricated for each of 6 experimental groups and 1 control group. All 7 definitive casts had 3 implants arranged in a triangular pattern creating a plane. In the 6 experimental groups, the center implant was perpendicular to the plane of the cast while the outer implants had 5, 10, or 15 degrees convergence towards or divergence away from the center implant. The control definitive cast had all 3 implants parallel to each another and perpendicular to the plane of the cast. Five open tray and 5 closed tray addition silicone impressions were made of each definitive cast. Impressions were poured with type IV dental stone, and a fine tip measuring stylus was used to record multiple axis (X-Y-Z) coordinates on the top surface of the implant hex and on the cast base. Computer software was used to align the data sets and vector calculations determined the difference in degrees between the implant angles in the definitive cast and the duplicate casts. Statistical analysis used repeated-measures ANOVA (alpha=.05) with post-hoc tests of significant interactions. The angle errors for the closed and open tray impression techniques did not differ significantly (P=.22). Implant angulations and implant numbers differed in average angle errors but not in any easily interpreted pattern (P<.001). The combined interaction of impression technique, implant angulation, and implant number had no effect on the accuracy of the duplicate casts compared to the definitive casts (P=.19). The average angle errors for the closed and open tray impression techniques did not differ significantly. There was no interpretable pattern of average angle errors in terms of implant angulation and implant number. The magnitude of distortion was similar for all combinations of impression technique, implant angulation, and implant number.

A simple procedure for minimizing adjustment of immediate complete denture: a clinical report

This article describes fabrication of a clear surgical template that minimizes pressure caused by immediate complete dentures on a surgical area. The trimmed areas on the maxillary definitive stone cast were further trimmed on the duplicated stone cast for making the clear surgical template. The procedure provided proper seating of the immediate complete denture, comfort for the patient, and reduced postoperative soreness and denture adjustments.

Nephrolithiasis and pregnancy.

Urolithiasis during pregnancy is not common, however, it is a difficult condition to both diagnose and treat. There are many safety concerns that must be considered for both the mother and fetus. In this review we detail the different options available to the urologist and we highlight a treatment algorithm that we use when faced with a pregnant patient suspect of having a urinary calculus. Changes in ultrasound, limited intravenous urograms and magnetic resonance imaging have improved our ability to diagnose urolithiasis in pregnancy. Additionally ureteroscopy has emerged not only as a diagnostic tool but also as a modality for definitive treatment that can safely be used during the intrapartum period. When diagnosing urolithiasis in the gravid patient, the first line study should be ultrasound, using change in resistive index and transvaginal ultrasound. If these are not diagnostic, then a limited intravenous urograms should be performed. Once a diagnosis has been established, initial treatment should be conservative since 70-80% of patients will pass their stones. When intervention is necessary, the placements of an internal stent or percutaneous nephrostomy tube or ureteroscopy with definitive stone treatment are all reasonable options.

Ureteroscopy and holmium:YAG laser lithotripsy: an emerging definitive management strategy for symptomatic ureteral calculi in pregnancy

Objectives. To review the results of holmium laser lithotripsy in a cohort of patients who presented with symptomatic urolithiasis in pregnancy. Symptomatic urolithiasis in pregnancy that does not respond to conservative measures has traditionally been managed with ureteral stent insertion or percutaneous nephrostomy. Holmium:yttrium-aluminum-garnet (YAG) laser lithotripsy using state-of-the-art ureteroscopes represents an emerging strategy for definitive stone management in pregnancy. Methods. A retrospective analysis was conducted at two tertiary stone centers from January 1996 to August 2001 to identify pregnant patients who were treated with ureteroscopic holmium laser lithotripsy for symptomatic urolithiasis or encrusted stents. Eight patients with a total of 10 symptomatic ureteral calculi and two encrusted ureteral stents were treated. The mean gestational age at presentation was 22 weeks. The mean stone size was 8.1 mm. The stones were located in the proximal ureter/ureteropelvic junction (n = 3), midureter (n = 1), and distal ureter (n = 6). Results. Complete stone fragmentation and/or removal of encrusted ureteral stents were achieved in all patients using the holmium:YAG laser. The overall procedural success rate was 91%. The overall stone-free rate was 89%. No obstetric or urologic complications were encountered. Conclusions. Ureteroscopy and holmium laser lithotripsy can be performed safely in all stages of pregnancy, providing definitive management of symptomatic ureteral calculi. The procedure can be done with minimal or no fluoroscopy and avoids the undesirable features of stents or nephrostomy tubes.

4626 Wire-guided intraductal ultrasound - an adjunct to ercp in the management of common bile duct stones.

Introduction: Cholangiography (ERC) may misdiagnose CBD stones if air bubbles are introduced during contrast injections and it may also fail to diagnose stones in the presence of marked bile duct dilation. Aim:To determine whether IDUS could be a useful adjunct in the management of CBD stones. Methods: IDUS using a wire-guided ultrasound probe(UMG20 29R,Olympus)was performed after initial ERC in patients with suspected CBD stones. The endoscopist noted the probability of CBD stones and sludge (definite, high, intermediate and low) after initial ERC and then noted additional or change in diagnosis after IDUS. Results: ERC with IDUS was performed in 28 patients with suspected CBD stones. CBD stones were confirmed after sphincterotomy and stone extraction in 12 patients. In these 12 patients, ERC classified 5 as definite stones and 5 as high probability. IDUS definitively identified CBD stones in 11 of 12 patients with confirmed CBD stones (PPV 100%, NPV 94%). IDUS confirmed stones in 9 of the 10 patients with high or definite probability ERC. In addition, IDUS identified stones in 1/13 patients classified as intermediate and 1 patient classified as low probability at ERC. Both were confirmed after sphincterotomy and extraction. In addition, IDUS demonstrated air bubbles in 2 patients and subsequent ballooon exploration confirmed the absence of stones. Performance of wire-guided IDUS required a mean of 4.3 ±0.2 minutes. Additional diagnostic information provided by IDUS included identification of cystic duct stones in 3 patients and choledochal varices in 1 patient. Conclusions: IDUS imaging was found to be a useful adjunct to ERC because it helped change management in 4/28 (14%) patients with suspected CBD stones. Specifically, sphincterotomy was performed in 2 patients with IDUS confirmed stones and was avoided in 2 patients with injected air bubbles