Absence Of Stones Research Articles

Computer Aided Diagnosis System for Stone Detection and Early Detection of Kidney Stones

Problem statement: Most of the previous study in diagnosis of kidney stone identifies a mere presence or absence of the stones in the kidney. However proposal in our study even present an early detection of kidney stones which helps to change the diet conditions and prevent the formation of stones. Approach: The study presented a scheme for ultrasound kidney image diagnosis for stone and its early detection based on improved seeded region growing based segmentation and classification of kidney images with stone sizes. With segmented portions of the images the intensity threshold variation helps in identifying multiple classes to classify the images as normal, stone and early stone stages. The improved semiautomatic Seeded Region Growing (SRG) based image segmentation process homogeneous region depends on the image granularity features, where the interested structures with dimensions comparable to the speckle size are extracted. The shape and size of the growing regions depend on this look up table entries. The region merging after the region growing also suppresses the high frequency artifacts. The diagnosis process is done based on the intensity threshold variation obtained from the segmented portions of the image and size of the portions compared to that of the standard stone sizes (less than 2 mm absence of stone, 2-4 mm early stages and 5mm and above presence of kidney stones). Results: The parameters of texture values, intensity threshold variation and stones sizes are evaluated with experimentation of various Ultrasound kidney image samples taken from the clinical laboratory. The texture extracted from the segmented portion of the kidney images presented in our study precisely estimate the size of the stones and the position of the stones in the kidney which was not done in the earlier studies. Conclusion: The integrated improved SRG and classification mechanisms presented in this study diagnosis the kidney stones presence and absence along with the early stages of stone formation.

Colecistectomía laparoscópica en régimen de cirugía mayor ambulatoria en un hospital comarcal: resultados iniciales de una serie de 110 casos

Introduction The aim of our study was to analyze the reliability of laparoscopic cholecystectomy (LC) in an Ambulatory Surgery unit, in order to encourage its use and achieve better management of health resources. Material and method Retrospective study of 110 patients operated on for LC between September 2004 and November 2008. The selection criteria were: absence of prior supramesocolic abdominal surgery, no previous admission for acute cholecystitis, absence of stones in the bile ducts and normal liver function tests, no intake of oral anticoagulants or antiplatelet agents and ASA I-II. All patients were operated using a previously established Major Ambulatory Surgery (MAS) protocol. Results The patients included 81 women and 29 men, with a mean age of 51.03 years (range 24–77), of which 57 had a medical and / or surgical history. The overall morbidity was 6.36% with a mortality of 0%. The conversion rate was 0.9%. A total of 87 patients (79.1%) were discharged at 6 h after surgery, thus fulfilling the criteria of the MAS system. The mean overall hospital stay was 1.49 days (median 0). The reoperation rate WAS 1.81% and the rate of readmission after discharge was0.9%. Conclusions The performance of outpatient laparoscopic cholecystectomy is feasible and safe. It should be integrated into the activities of Major Ambulatory Surgery, ensuring careful selection of patients and interest by surgeon who performs it.

Laparoscopic cholecystectomy performed as ambulatory major surgery in a regional hospital. Initial results of a series of 110 cases

IntroductionThe aim of our study was to analyse the reliability of laparoscopic cholecystectomy (LC) in an Ambulatory Surgery unit, in order to encourage its use and achieve better management of health resources. Material and methodRetrospective study of 110 patients operated on for LC between September 2004 and November 2008. The selection criteria were: absence of prior supramesocolic abdominal surgery, no previous admission for acute cholecystitis, absence of stones in the bile ducts and normal liver function tests, no intake of oral anticoagulants or antiplatelet agents and ASA I-II. All patients were operated using a previously established Major Ambulatory Surgery (MAS) protocol. ResultsThe patients included 81 women and 29 men, with a mean age of 51.03 years (range 24–77), of which 57 had a medical and/or surgical history.The overall morbidity was 6.36% with a mortality of 0%. The conversion rate was 0.9%. A total of 87 patients (79.1%) were discharged at 6h after surgery, thus fulfilling the criteria of the MAS system. The mean overall hospital stay was 1.49 days (median 0). The reoperation rate was 1.81% and the rate of readmission after discharge was 0.9%. ConclusionsThe performance of outpatient laparoscopic cholecystectomy is feasible and safe. It should be integrated into the activities of Major Ambulatory Surgery, provided that patients are carefully selected and the surgeons performing it take a special interest.

Acute cholangiopancreatic diseases with situs inversus totalis treated with endoscopic sphincterotomy: Report of two cases

Acute cholangiopancreatic diseases with situs inversus totalis treated with endoscopic sphincterotomy: Report of two cases

An experimental study of crust development on chalk downland soils and their impact on runoff and erosion

SummaryThe sealing of soil surfaces by rainfall, the development of soil crusts and their impact on runoff and erosion was investigated in the laboratory by means of simulated rainfall. The soils investigated were stone‐free samples of chalk soils from southeast England, and soils with a 25% cover of stones. Vertical change to the surface and immediate subsurface of the soils was assessed through the examination of thin sections scanned into a computer and analysed with image processing software. Changes in roughness and microtopography of the soil surface were measured by use of a laser micromapper. Crusting occurred both in the presence and absence of stones and was inversely related to the organic matter content and aggregate stability of the soils. Crusting of stone‐free soils was accompanied by a reduction in roughness of the soil surface, but roughness of the stone‐covered surfaces increased as crusting developed. Increases in the particle density of the crust were related to silt content. Organic‐rich soil from under permanent grass and from a soil recently brought into arable cultivation crusted less than soils used for arable cultivation for longer periods with lower organic content. The inwashing of silt into the pores of the soil during crusting reduces infiltration, and increases runoff and erosion. In the presence of a 25% cover of surface stones, the reduction in infiltration was 25% less than for stone‐free soils and erosion ∼50% less.

Acalculous cholecystitis due to Salmonella enteritidis

Acute acalculous cholecystitis (AAC) is defined as an acute inflammation of the gallbladder in the absence of stones. We herein report a case of a young man who developed AAC after a Salmonella enteritidis gastrointestinal infection.

PD-06.08: Laparoscopy assisted retroperitoneal pyeloplasty and via pelvis stone removal

In the treatment of UPJ obstruction, laparoscopic pyeloplasty has limitations for the removal of combined renal stones. Antegrade endopyelotomy has a low succes rate in the presence of poor renal function and needs an extended catheter indwelling time. We conceived a less invasive surgical technique for UPJ obstruction in the presence or absence of stones, which is a hybridized form of laparoscopic, endoscopic and conventional open surgery.

Incidence of symptomatic gallstones after gastric bypass: is prophylactic treatment really necessary?

Background Because rapid weight loss after bariatric surgery increases gallstone formation, a 6-month treatment regimen with ursodiol has been recommended. Even prophylactic cholecystectomy at the time of gastric bypass in the absence of stones has been proposed. However, the incidence of symptomatic gallstones requiring cholecystectomy in untreated patients after gastric bypass has not yet been established. Methods The patients in our study were not treated with ursodiol after open Roux-en- Y gastric bypass. Additional inclusion criteria were no palpable gallstones at bypass, at least 16 months of follow-up after bypass, and continuous coverage by the same health insurance plan extending from the time of the operation to study completion, to track subsequent cholecystectomies by claims paid. Results A total of 100 females and 25 males met the study inclusion criteria. Follow-up extended from 16 to 48 months. Symptomatic gallstones requiring cholecystectomy developed in 10 patients, all females. Laparoscopic cholecystectomy was performed in 9 of these patients and open cholecystectomy was performed in the remaining patient, between 3 and 21 months after bypass. There were no serious complications from the stones or the cholecystectomy. Conclusions Prophylactic cholecystectomy would have been unnecessary in 115 of the 125 patients in the study group. A 6-month course of ursodiol for all 125 patients, at a cost of $56,250, would have had to decrease the number of cholecystectomies from 10 to 3 to demonstrate a treatment effect ( P < .05). Therefore, most newly formed gallstones after gastric bypass are likely asymptomatic, prophylactic cholecystectomy is not indicated, and ursodiol therapy may be better reserved for symptomatic patients who refuse surgery. © 2005 American Society for Bariatric Surgery

Is idiopathic recurrent calcium urolithiasis in males a cellular disease? Laboratory findings in plasma, urine and erythrocytes, emphasizing the absence and presence of stones, oxidative and mineral metabolism: an observational study

The site of origin of idiopathic recurrent calcium urolithiasis (IRCU)--a disorder characterized by stones composed of calcium oxalate (CaOx) and/or calcium phosphate (CaPi)--is uncertain, because in urine such risk factors for stones as disturbed Ox, Ca and Pi are not regularly observed. To evaluate whether imbalance of antioxidants and oxidants might be present in IRCU patients that is then followed by abnormal urine, plasma and intracellular mineral homeostasis, and stones. Males were investigated in the laboratory under standardized conditions, and three trials were organized. Trial 1 was cross-sectional, comparing IRCU patients with (n = 111) and without stones in situ (n = 126), focussing on abnormalities of oxypurines and minerals in urine and plasma, and metabolic activity (MA) of the disease. Trial 2 was partly controlled (n = 14 healthy subjects; n = 53 IRCU patients), comparing the plasma levels of total antioxidant status (TAS) and uric acid, the major antioxidant in humans, using the subsets Low (n = 26) and High (n = 27) TAS among IRCU patients in terms of plasma levels of uric acid, ascorbic acid, albumin, alpha-tocopherol and minerals, urinary minerals, CaOx and CaPi (hydroxyapatite) supersaturation. Trial 3, comprising stone-free IRCU patients (n = 8) and healthy controls (n = 8), compared minerals and mineral ratios in plasma and red blood cells (RBCs). Established analytical methodologies were used throughout. In trial 1, uricemia, hypoxanthinuria and proteinuria were elevated, fractional urinary clearance (FE) of uric acid was decreased in stone-bearing patients, and MA correlated positively with uricemia and urinary total protein excretion. In trial 2, TAS was significantly decreased in IRCU patients vs. healthy controls; low TAS coincided with low plasma uric acid and albumin, unchanged ascorbic acid, alpha-tocopherol and parathyroid hormone, but increased FE-uric acid and Pi excretion; the latter correlated negatively with TAS. In trial 3, plasma minerals were significantly decreased in IRCU patients vs. controls, and Ca/Pi, (Ca/Pi)/Mg and (Ca/Pi)/Na molar ratios increased; the latter ratio was also increased in RBCs, and correlated highly positively with the same ratio in plasma. In IRCU 1) renal stones in situ in combination with high fasting uricemia, high hypoxanthinuria and protein-uria, and high MA suggest that a systemic metabolic anomaly underlies stone formation; 2) antioxidant deficit is frequent, unrelated to the presence or absence of stones but apparently related to poor renal uric acid recycling, low uricemia and albuminemia, exaggerated urinary Pi excretion, and low MA; 3) the combination of low plasma TAS, disordered Ca/Pi and other mineral ratios in urine, plasma and RBCs, but unchanged urinary Ca salt supersaturation is compatible with the view that CaPi solid and Ca microlith formation start inside oxidatively damaged cells.

Dilated Ducts: Is It a Reliable Sign for Choledocholithiasis in Patients with Acute Biliary Pancreatitis (ABP)?

BACKGROUND: The passage of gallstones though common bile duct (CBD) is one of the most common causes of acute pancreatitis (“biliary pancreatitis”). CBD is often dilated as a result of edema in head of pancreas or due to presence of stones. The degree of CBD dilation may be a predictive factor for presence of CBD stones and may help decide the need for pre-operative ERCP. AIMS: To study the correlation between the size of the CBD and presence of CBD stones in patients with ABP and cholelithiasis METHODS: All cases with ABP and cholelithiasis undergoing ERCP were studied. Size of the CBD as measured during ERCP was used to calculate the probability of CBD stones (Chi square and T tests). Balloon sweep of the bile duct was used as gold standard to check for the presence or absence of stones. RESULTS: Four hundred and eight-six patients with ABP undergoing ERCP for presumed CBD stones were studied. Of the 486 patients (male=216, female=270, mean age=49) 73 were found to have stones while 413 did not have the stones. Using the Chi square test there was no correlation found between the duct diameter and presence of CBD stones (table). Using the T test analysis there was a trend towards presence of CBD stones with larger (>9mm) CBD size (table). CONCLUSIONS: In patients with acute biliary pancreatitis and nondilated CBD, CBD size cannot be used as a reliable predictor to rule out presence of CBD stones. CBD size more then 9 mm may be used as a predictor for CBD stones for making a decision for ERCP prior to cholecystectomy.

Dilated Ducts: Is It a Reliable Sign for Choledocholithiasis in Patients with Acute Calculous Cholecystitis (ACC)?

BACKGROUND: In patients presenting with ACC common bile duct (CBD) stones need to be ruled out prior to surgery. Besides other variables, the degree of CBD dilation may be a predictive factor for presence of CBD stones and may help decide need for pre-operative ERCP. AIMS: To study the correlation between the size of the common bile duct and presence of CBD stones in patients with ACC. METHODS: All cases with ACC and cholelithiasis undergoing ERCP were studied. Size of the CBD as measured during ERCP was used to calculate the probability of CBD stones (Chi square and T tests). Balloon sweep was used as gold standard to check for the presence or absence of stones. RESULTS: Three hundred and forty-five patients with ACC undergoing ERCP for presumed CBD stones during last 5 years were studied. Of the 345 patients (male=200, female=145, mean age=49) 218 were found to have CBD stones while 127 did not have the stones. Using the Chi square test there was no correlation found between the duct diameter and presence of CBD stones (table). Using the T test analysis CBD, size was not found to be a reliable predictor of CBD stones (table). CONCLUSIONS: In patients with acute calculus cholecystitis and non dilated CBD, CBD size alone cannot be used to rule out the presence of CBD stones. In patients with dilated ducts, CBD size alone may not be a good predictor of presence of CBD stones and other variables should be taken into consideration for decisions for ERCP prior to cholecystectomy.

Impact of Date of Onset on the Absence of Hematuria in Patients with Acute Renal Colic

Hematuria is absent in a significant proportion of patients with acute ureterolithiasis. We determined whether time from pain onset has any impact on the sensitivity of hematuria tests in the diagnosis of ureterolithiasis. We retrospectively reviewed the records of 537 patients with suspected acute unilateral renal colic during a 29-month period with regard to the interval between pain onset and urinalysis, including the dipstick test and microscopic red blood cell count as well as other clinical findings. Although ureterolithiasis was determined by plain x-ray and ultrasonography primarily, stone absence was diagnosed by computerized tomography. Ureterolithiasis was diagnosed in 452 patients (84.2%). The dipstick test had higher sensitivity (0.780 vs 0.718) but it was equivalent on ROC analysis compared with microscopic examination (area under the curve 0.696 vs 0.694, p = 0.92). Hematuria test sensitivity was 0.95, 0.83, 0.65, 0.68, 0.77, 0.86 and 0.68 on days 0, 1, 2, 3, 4, 5 to 7 and 8 or more from pain onset, respectively (ANOVA p = 0.004). On logistic regression analysis including hydronephrosis grade, and stone size and location the interval between onset and urinalysis was the only independent factor affecting the incidence of negative hematuria in patients with ureterolithiasis (p = 0.03, 95% CI 0.89 to 0.99). The interval between pain onset and urine collection has a significant impact on the diagnostic performance of hematuria tests. The incidence of negative hematuria is highest on the days 3 and 4.

Histologic Findings of Gallbladder Mucosa in 87 Patients With Morbid Obesity Without Gallstones Compared to 87 Control Subjects

Obesity is an important risk factor for the development of gallstones. The purpose of this study was to determine histologic alterations in the gallbladder mucosa and the prevalence of gallstone disease in patients with severe and morbid obesity compared to histologic findings in the gallbladder mucosa of control subjects. Two groups were studied: 125 severely obese patients (38 with and 87 without gallstones) and 87 control subjects. Ultrasonography was performed in all of them before surgery. During surgery, cholecystectomy was performed in 87 obese patients with a “normal” gallbladder and in all 87 control subjects. Specimens were immediately sent for histologic analysis. The prevalence of gallstones was twice as high among obese women compared to obese men ( P < 0.001). Normal gallbladder mucosa was found in 28.7% of obese women compared to 34.2% of control women ( P > 0.59). Findings were similar among the men. The most frequent histologic abnormality in the gallbladder mucosa among obese women was cholesterolosis (37%), followed by chronic cholecystitis and cholesterolosis (18%), with frequencies of 23% and 12%, respectively, in control women ( P > 0.1). Among men, a similar proportion of histologic abnormalities was seen in obese men and control subjects. In our population of obese patients compared to control subjects, a similarly high proportion of histologic abnormalities of the gallbladder mucosa was found in the absence of stones. These findings could have been attributed to the fact that the Chilean population has a high incidence of gallstones. ( J Gastrointest Surg 2003;7:547–551).

EUS for suspected choledocholithiasis: Do benefits outweigh costs? A prospective, controlled study

This prospective study of the use of EUS to prevent unnecessary endoscopic retrograde cholangiography in patients with suspected choledocholithiasis has two aims: to evaluate the effectiveness, based on patient outcome, and the potential clinical and economic benefits of EUS. A prospective series of 485 patients (202 men, 283 women; mean age 66.2 years, range 20-94 years) suspected to have choledocholithiasis based on clinical, biochemical, and cross-sectional imaging (US or CT) data underwent EUS. Positive EUS findings were confirmed by endoscopic retrograde cholangiography with sphincterotomy and/or by surgery; negative findings were confirmed by clinical follow-up. An EUS result was considered a true negative if the patient was confirmed symptom-free with normal tests on follow-up of at least 6 months. The costs of EUS (procedure, days of hospitalization, any morbidity) were compared with the estimated costs of the endoscopic retrograde cholangiography avoided in patients with true-negative EUS findings. EUS findings were verified in 463 patients: EUS diagnosed choledocholithiasis in 239 (51.6%) and the absence of stones in 220 patients. In 4 patients (0.8%), EUS was incomplete. By sphincterotomy (209 patients), surgical bile duct exploration (39), percutaneous cholangiography (1 case in which EUS demonstrated a bile duct tumor), and follow-up (214), EUS diagnoses were confirmed as follows: 237 true-positive, 216 true-negative, 2 false-positive, 4 false-negative, 4 incomplete (sensitivity 98%, specificity 99%, positive predictive value 99%, negative predictive value 98%, accuracy 97%). In 214 (46%) patients, more invasive investigations of the bile duct were avoided. The mean cost for patients managed by the EUS-based strategy was ' 374.50 (-284.72), which was significantly less than the theoretical mean cost of ' 443.80 (p < 0.001) for patients undergoing endoscopic retrograde cholangiography. The results of this study confirm that EUS is highly reliable for the diagnosis of choledocholithiasis. Its use offers considerable clinical and economic advantages by preventing inappropriate and more invasive evaluation of the bile duct.

The value of magnetic resonance cholangiopancreatography in predicting common bile duct stones in patients with gallstone disease.

The application of available predictive scoring systems for the detection of common bile duct (CBD) stones has not reduced the number of patients who undergo unnecessary endoscopic retrograde cholangiopancreatography. The aim of this study was to create a predictive model for CBD stones and to assess the value of magnetic resonance cholangiopancreatography (MRCP) in prediction. In 1998, 366 patients with gallstone disease (118 males, 248 females; mean age 57 (range 8-84) years) underwent cholecystectomy. Statistical analysis was performed on patient data obtained at the time of first presentation. CBD stones were demonstrated in 43 (12 per cent) of 366 patients. The predictive model for common duct stones included ultrasonography showing CBD stones or bile duct dilatation, age greater than 60 years, fever, serum alkaline phosphatase level above 670 units/l and serum amylase level above 95 units/l. In patients with a predicted probability greater than 5 per cent, CBD stones were present in 11 per cent, compared with 1 per cent in patients with a probability of 5 per cent or less. MRCP had an observed sensitivity of 95 per cent, specificity of 100 per cent, positive predictive value of 100 per cent and negative predictive value of 98 per cent. In patients with a predicted probability for CBD stones of more than 5 per cent, MRCP is recommended in order to confirm the presence or absence of stones and as guidance in further management.

Noncalculous biliary obstruction in the child and adolescent

tract disease is uncommon in patients 1 to 21 years of age. Ulin and coworkers 1 reported only 1.3 cases of cholecystitis in this age group for every 1,000 adult cases at the Mayo Clinic. Cholecystitis rarely develops in male patients less than 19 years of age, constituting only 0.7% of all cholecystectomies in one series of more than 2,000 patients. 2 Cholelithiasis is responsible for the majority of pediatric cases of cholecystitis especially in high-risk groups such as obese adolescent girls and those with various hemoglobinopathies. Acalculous cholecystitis is also a particular problem in this age group, constituting 30% to 50% of all cases of pediatric cholecystitis, compared with only 3% to 17% reported in adults. 3 Extrahepatic bile duct obstruction is even more uncommon than cholecystitis in this age group. Although the most common cause is choledocholithasis, the incidence of common duct stones in patients less than 16 years of age undergoing biliary operations has been reported to be less than 0.22%. 4 Although other causes of biliary obstruction are rare, obstructive jaundice in the young patient in the absence of stones may pose a diagnostic dilemma requiring a thorough investigation and often resulting in a protracted course of treatment. This article reviews the various noncalculous etiologies of biliary obstruction in patients 21 years old or younger and proposes a diagnostic algorithm that may be helpful in the evaluation of the young jaundiced patient.

7157 Duodenoscope-assisted cholangiopancreatoscopy (dacp) achieves technical aims and impacts on biliary and pancreatic disease management.

Background: DACP, as an adjunct to ERCP allows for direct visualization of the biliary duct and pancreatic duct.We aim to assess the technical feasibility of DACP for a variety of clinical indications and to determine its impact on disease management. Methods: 94 consecutive DACP examinations were performed in 57 patients with 3 groups of disorders, choledocholithiasis (CDL), biliary strictures(BS) and pancreatic disease(PD), age range (24 to 91 years; mean 69). All DACPs were performed using the Pentax FCP-8P or 9P. Data pertaining to indication, technical success, and clinical impact of DACP on disease management were collected and analyzed using cMore endoscopic database. Results: CDL (n=53, 27 pts ) Indications included stone fragmentation using EHL (n=34), evaluation of biliary tree post-stone removal (n=14), distinction between stone and stricture, evaluation of biliary tree for stones despite normal cholangiogram (n=5). Technical success was achieved in 29/53 DACPs. The 24/53 failures represent partial fragmentation of stones with EHL in 8 patients with extensive disease. Use of DACP resulted in complete removal of biliary tree stones in 10/34 examinations (10 patients) and demonstrated the presence of stones in 4 patients with normal post-interventional cholangiograms. Furthermore DACP helped to confirm the absence of stones after removal by basket or balloon in 11/12 patients. BS (n=33, 23 pts) Indications included evaluation of stricture(n=21) or Wallstent occlusion (n=4), and monitoring of cholangiocarcinoma progression in a single patient (n=7). Technical success was achieved in 29/33 cases. DACP assisted in confirming or clarifying the nature of a stricture in 16/29 cases, and in stent management in 20/29 cases. PD (n=7) Indications included evaluation of pancreatic duct obstruction in chronic pancreatitis (n=4) and malignancy (n=1), and evaluation of PD for IPMT (n=2). An additional use of DACP was in the evaluation of hemobilia (n=1) where no source was seen. There were no complications reported with the use of DACP. Conclusion: DACP is technically feasible in the management of pancreatico-biliary diseases. Lack of complete technical success in the use of EHL to fragment stones is due to extensive stone disease in a limited number of patients. Otherwise DACP impacts on the management of complicated biliary tract disease by clarifying cholangiograms, assisting in EHL stone fragmentation, and guiding stenting and surgical management.

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

Choledocholithiasis: a prospective study of spontaneous common bile duct stone migration

Background: The rate of spontaneous migration of bile duct stones through the duodenal papilla is not well known. Endoscopic retrograde cholangiography (ERC) has been the standard method to diagnose bile duct stones, but accumulating data show there is a good agreement between ERC and endoscopic ultrasonography (EUS). The aim of the study was to evaluate the incidence and time course of stone migration in patients with bile duct stones by analyzing discrepancies between EUS and ERC as a function of the elapsed time between these two procedures. Stone migration was considered as the absence of stones at time of ERC regardless of the number of stones seen at EUS. Methods: The main criterion for inclusion was the presence of bile duct stone as shown by EUS. Ninety-two consecutive patients were prospectively included in this study. Results: Choledocholithiasis was absent at ERC in 12 patients. In univariate analysis, presence of gallbladder was significantly associated with an increased rate of stone migration (correction for multiple testing would remove this statistical significance). The size of the stone was the only independent factor to predict migration. Conclusion: Migration occurred in about 21% of cases within 1 month. Our study emphasizes the need to analyze carefully the results of comparative imaging studies of bile duct stones. (Gastrointest Endosc 2000;51:175-9.)

Dilatation of the collecting system during pregnancy: physiologic vs obstructive dilatation.

Dilatation of the collecting system is a classical phenomenon during pregnancy, due to hormonal and extrinsic compressive factors. Imaging has to differentiate a physiological dilatation and a pathological obstruction due to urolithiasis. Presently, sonography, using both, B-mode and color Doppler, has the potential to demonstrate the physiological compression of ureters at the level of the pelvic brim. A pathological obstruction is considered either when a stone is detected above the usual site of compression or when the ureter appears dilated beyond. Color Doppler helps in localizing the site of ureteral compression against the vessels and in differentiating ureters from veins. Magnetic resonance urography, with strongly T2-weighted sequences, also may show the site and type of obstruction without contrast agent administration. These two non-radiating techniques make it possible to avoid the use of X-rays in most cases for management of these patients. The type of treatment is based mostly on the level of pain and the presence or absence of stone.