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Biomedical subjects

A Chak

Publications and source records attributed to A Chak.

At least 55 records · Page 3Linked to original sources
PubMed1999

Prospective assessment of the utility of EUS in the evaluation of gallstone pancreatitis.

BACKGROUND: The ability to identify common bile duct stones by noninvasive means in patients with acute biliary pancreatitis is limited. The aim of this study was to prospectively evaluate the ability of endosonography (EUS) to identify cholelithiasis and choledocholithiasis and predict disease severity in patients with nonalcoholic pancreatitis. METHODS: EUS was performed immediately before endoscopic retrograde cholangiopancreatography (ERCP) by separate blinded examiners within 72 hours of admission. Gallbladder findings were compared between EUS and transabdominal ultrasonography (US). Using endoscopic extraction of a bile duct stone as the reference standard for choledocholithiasis, the diagnostic yield of EUS was compared with transabdominal US and ERCP. Features identified during endosonographic imaging of the pancreas were correlated with length of hospitalization. RESULTS: Thirty-six patients were studied. EUS and transabdominal US were concordant in their interpretation of gallbladder findings in 92% of patients. The sensitivity of transabdominal US, EUS, and ERCP for identifying choledocholithiasis was 50%, 91%, and 92% and the accuracy was 83%, 97%, and 89%, respectively. Length of hospital stay was longer in patients with peripancreatic fluid (9.2 vs. 5.7 days, p < 0.1) and shorter in patients with coarse echo texture (2.6 vs. 7.2 days, p < 0.05) demonstrated on EUS. CONCLUSIONS: EUS can reliably identify cholelithiasis and is more sensitive than transabdominal US in detecting choledocholithiasis in patients with biliary pancreatitis. EUS may be used early in the management of patients with acute pancreatitis to select those who would benefit from endoscopic stone extraction. The utility of EUS for predicting pancreatitis severity requires further investigation.

Abdomen↗
PubMed1999

Early endoscopy in upper gastrointestinal hemorrhage: associations with recurrent bleeding, surgery, and length of hospital stay.

BACKGROUND: The impact of upper endoscopy in patients with upper gastrointestinal hemorrhage treated in community practice is unknown. Thus we examined the effectiveness of endoscopy performed within 24 hours of admission (early endoscopy). METHODS: Medical records of 909 consecutive hospitalized patients with upper gastrointestinal hemorrhage who underwent endoscopy at 13 hospitals in a large metropolitan area were reviewed. We evaluated unadjusted and severity-adjusted associations of early endoscopy with recurrent bleeding or surgery to control hemorrhage, length of hospital stay, and associations of endoscopic therapy in patients with bleeding ulcers or varices. RESULTS: Early endoscopy was performed in 64% of patients and compared with delayed endoscopy and was associated with clinically significant reductions in adjusted risk of recurrent bleeding or surgery (odds ratio [OR] 0.70: 95% CI [0.44, 1.13]) and a 31% decrease in adjusted length of stay (95% CI: [24%, 37%]). In patients at high risk for recurrent bleeding, the use of early endoscopic therapy to control hemorrhage was associated with reductions in recurrent bleeding or surgery (OR 0.21: 95% CI [0.10, 0.47]) and length of stay (-31%: 95% CI [-44%, -14%). CONCLUSION: In this study of community-based practice, the routine use of endoscopy, and in selected cases endoscopic therapy, performed early in the clinical course of patients with upper gastrointestinal hemorrhage was associated with reductions in length of stay and, possibly, the risk of recurrent bleeding and surgery.

Adult↗
PubMed1999

Evaluation of metastatic celiac axis lymph nodes in patients with esophageal carcinoma: accuracy of EUS.

BACKGROUND: Endosonography (EUS) is the most accurate modality for assessing depth of tumor invasion and local lymph node metastasis. However, its accuracy in the identification of metastatic (celiac axis) lymph nodes is less well defined. Our objective in this study was to determine the accuracy of Eus in detecting celiac axis lymph node metastasis in patients with esophageal carcinoma. METHODS: Two hundred fourteen patients with esophageal carcinoma underwent preoperative EUS. Of these, 145 underwent attempted surgical resection and staging, and 4 underwent EUS-guided fine-needle aspiration of mediastinal and celiac lymph nodes. Local (mediastinal) and distant (celiac axis) lymph nodes were assessed for malignancy on the basis of four criteria (larger than 1 cm, round, homogeneous echo pattern, sharp borders). Accuracy of EUS was determined by means of correlating histopathologic findings for the resected lymph nodes or results of EUS-guided fine-needle aspiration cytologic examination. RESULTS: Surgical exploration (n = 145) and fine-needle aspiration cytologic examination (n = 4) revealed metastatic celiac axis lymph nodes in 23 and metastatic mediastinal (local) lymph nodes in 93 of 149 patients with esophageal carcinoma. According to defined criteria for malignant lymph nodes, there were 19 true-positive and 4 falsenegative results. Sensitivity for the diagnosis of celiac lymph node metastasis with EUS was 83% with a 98% specificity. For the diagnosis of mediastinal lymph node metastasis, sensitivity was 79% and specificity was 63%. All patients with malignant celiac axis lymph nodes had local T3 (tumor breaching adventitia) or T4 (tumor invading adjacent organs) disease. CONCLUSION: EUS is an excellent modality in the evaluation of metastatic celiac axis lymph nodes in patients with esophageal carcinoma. These findings should be used in selecting options for treatment. Sensitivity for detecting malignancy is consistent with that of prior studies, and local and regional lymph nodes and specificity is significantly higher.

Aged↗
PubMed1999

Procedure-specific outcomes assessment for endoscopic ultrasonography.

Endosonography (EUS) is a relative newcomer to the field of gastrointestinal endoscopy. Nevertheless, two prospective studies with similar results have shown that EUS leads to a change in management in roughly two-thirds of patients in whom it is performed, with many of these changes being to less invasive or less expensive management. Preliminary investigations on the use of catheter probes for performing EUS have shown similar effects. Specific investigations on the effect of EUS on the outcomes of patients with submucosal tumors, esophageal cancers, pancreatic cancers, and rectal cancers need to be performed. Selective studies have demonstrated EUS to be cost-effective for the management of submucosal tumors and ampullary tumors. The complication rate of EUS appears to be comparable to that of upper endoscopy. There is little or no information regarding training in EUS, practice variation, or affect of EUS on quality of life.

Cost-Benefit Analysis↗
PubMed1998

Endoscopic practice for upper gastrointestinal hemorrhage: differences between major teaching and community-based hospitals.

BACKGROUND: Differences in endoscopic practice in major teaching and community hospitals are not known. METHODS: A total of 1031 consecutive patients discharged from 13 hospitals (4 major teaching, 9 others) in 1994 with upper gastrointestinal hemorrhage were studied. Data obtained from chart abstraction included endoscopic findings and therapy and selected outcomes. Multivariable analyses adjusted for admission severity of illness and endoscopic findings. RESULTS: Rates of endoscopy were similar between patients admitted to major teaching and other hospitals, although procedures to control hemorrhage were used more often in major teaching hospitals (35% vs. 19%, p < 0.001). Use of endoscopic therapy was higher in major teaching hospitals for lesions in which therapy is recommended, as well as other lesions. Recurrent bleeding was also more common in major teaching hospitals (14.3% vs. 7.8%, p = 0.001), and the difference persisted in multivariable analysis (odds ratio 1.69: 95% CI [1.09 to 2.64], p = 0.02). Unadjusted and adjusted length of stay were somewhat shorter in major teaching hospitals. CONCLUSIONS: There was large variation in the use of endoscopic therapy, with higher rates observed in major teaching hospitals for lesions in which therapy is recommended, as well as other stigmata. Further studies are needed to better define the reasons for the practice variation and to assess the impact on other outcomes such as readmission and costs.

Aged↗
PubMed1998

Clinical implications of endoluminal ultrasonography using through-the-scope catheter probes.

BACKGROUND: Ultrasound catheter probe-assisted endosonography is a relatively new technique. The aim of this prospective multicenter study was to determine its potential clinical impact by assessing changes in diagnostic and therapeutic management affected by catheter probes compared with ultrasound endoscopes. METHODS: Endosonographers at three centers selected theoretic diagnostic and therapeutic plans that would be followed if neither catheter probes nor ultrasound endoscopes were available. Patients with suitable lesions underwent endosonography with catheter probes followed by an ultrasound endoscope. Diagnostic and therapeutic plans were noted after each examination. RESULTS: Sixty-six patients, of whom 15 had a stenotic esophageal cancer, 39 had a mucosal or submucosal lesion, and 12 had a stricture of the pancreaticobiliary system or the gastrointestinal tract, were enrolled. If neither form of endosonography were available, invasive or surgical diagnostic procedures would have been performed on 23 (35%) patients and surgical therapy would have been planned in 31 (47%) patients. Catheter probe-assisted ultrasonography and endoscopic ultrasonography led to a less invasive diagnostic plan in 11 (16%) and 12 (18%) patients and a less invasive therapeutic plan in 10 (15%) and 14 (21%) patients, respectively (p > 0.1 for differences). CONCLUSIONS: Catheter probe-assisted endosonography has a modest effect on diagnostic and therapeutic management, comparable with endoscopic ultrasonography in the same patients. The vast majority of effected changes are toward less invasive management.

Digestive System Neoplasms↗
PubMed1998

Endoscopic ultrasound in restaging of esophageal cancer after neoadjuvant chemoradiation.

BACKGROUND: Endoscopic ultrasound (EUS) is established as the most accurate method currently available for determining the depth of primary cancer invasion (T stage). Standard EUS criteria may not be accurate in assessing depth of cancer invasion and nodal status after patients have received chemotherapy or radiotherapy. METHODS: We conducted a prospective study to determine whether EUS estimation of tumor size could be used to assess response to preoperative chemoradiation. Using EUS, TNM stage was assessed in 31 patients (22 men, 9 women; mean age 62 years) with cancer of esophagus or cardia (19 adenocarcinoma, 12 squamous cell cancer) before initiation of combined radiation and 5-fluorouracil/cisplatin (and/or carboplatinum) chemotherapy. The cross-sectional area of the tumor in the transverse plane at the location where the tumor had maximal thickness was calculated to estimate tumor size. EUS staging and measurement of maximal cross-sectional area were repeated at completion of chemoradiation just before surgery. Response to preoperative chemoradiation was defined as 50% reduction in maximal cross-sectional area. Surgical staging was compared between responders and nonresponders. RESULTS: Eight patients who did not undergo surgery were excluded from analysis. EUST stage in the remaining 23 patients before therapy was as follows: 3 T2, 16 T3, and 4 T4. After chemoradiation, EUS T staging was changed in 6 patients (3 T4 downstaged to T3, 2 T3 downstaged to T2, and 1 T3 downstaged to T1). At surgical pathological examination, 3 patients had no residual tumor in the esophagus (T0), 5 had T1, 3 had T2, 10 had T3, and 2 had T4 tumors. EUS T staging accuracy after adjuvant therapy was only 43%. Maximal cross-sectional area decreased from a mean of 5.5 +/- 2.4 to 1.6 +/- 0.9 cm2 in responders, whereas maximal cross-sectional area went from 7.0 +/- 3.0 to 5.4 +/- 2.2 cm2 in nonresponders (p = 0.009). Ten of thirteen patients with at least a 50% reduction in maximal cross-sectional area (responders) had T0, T1, or T2 tumors at surgery, whereas 9 of 10 nonresponders had T3 or T4 tumors at surgery (p = 0.001). CONCLUSIONS: (1) Standard EUS staging criteria are not accurate after neoadjuvant chemoradiation, (2) reduction in maximal cross-sectional area of tumor appears to be a more useful measure for assessing response of esophageal cancer to preoperative chemoradiation, and (3) responders have an increased likelihood of downstaging at surgery than nonresponders.

Adenocarcinoma↗
PubMed1998

Endoscopic ultrasonography versus cholangiography for the diagnosis of choledocholithiasis.

BACKGROUND: Choledocholithiasis is a major source of morbidity among patients undergoing cholecystectomy for symptomatic gallstones. There is no consensus on the best approach to diagnosing bile duct stones. We compared the safety, accuracy, diagnostic yield, and cost of EUS- and ERCP-based approaches. METHODS: Sixty-four consecutive pre- and post-cholecystectomy patients referred for endoscopic retrograde cholangiopancreatography (ERCP) for suspected choledocholithiasis were prospectively evaluated in a blinded fashion. All were stratified into risk groups using predefined criteria. Endoscopic ultrasonography (EUS) and ERCP were sequentially performed by two endoscopists. RESULTS: The success rates of EUS and ERCP were 98% and 94%, respectively. The accuracy of EUS for diagnosing choledocholithiasis was 94%. EUS provided an additional or alternative diagnosis to bile duct stones in 21% of patients. The complication rate of EUS was significantly lower than diagnostic ERCP. An EUS-based strategy costs less than diagnostic ERCP in patients with low, moderate, or intermediate risk. CONCLUSIONS: EUS is comparably accurate, but safer and less costly than ERCP for evaluating patients with suspected choledocholithiasis. It is useful in patients with an increased risk of having common bile duct stones based on clinical criteria and those with contraindications for or prior unsuccessful ERCP. EUS may enable selective performance of ERCP and improve the cost-effectiveness of diagnosing choledocholithiasis.

Adult↗
PubMed1998

Diagnostic and therapeutic impact of push enteroscopy: analysis of factors associated with positive findings.

BACKGROUND: Push enteroscopy is indicated in patients with suspected small bowel gastrointestinal bleeding or small bowel mucosal disease. Our aim was to determine the diagnostic yield of enteroscopy, identify clinical predictors associated with findings, and measure frequency of management changes made on the basis of results. METHODS: Endoscopy reports, office charts, and hospital charts were reviewed for 164 patients who had enteroscopy performed, primarily with a video enteroscope, during a period of 2 years. Data extraction included details of comorbid illnesses, associated risk factors, and previous endoscopies. RESULTS: Indications for enteroscopy were suspected occult bleeding in 65, overt bleeding in 64, diarrhea in 20, and suspected mucosal disease in 15 patients. Diagnostic lesions, identified in 92 patients (56%), included 57 jejunal lesions (35%). In patients with overt bleeding, upper tract lesions were present more commonly in patients receiving nonsteroidal medication (54% versus 27%, p < 0.05). Jejunal vascular ectasia occurred more frequently in patients with documented vascular ectasias elsewhere in the gastrointestinal tract (34% versus 15%, p < 0.01). Missed lesions on previous upper endoscopy included large hiatal hernias with erosions in 10, peptic ulcers in 10, and vascular ectasias in 9 patients. Therapeutic interventions, made in 67 of 92 patients (73%) with diagnostic lesions, included small bowel resection in 12 (8%), endoscopic therapy in 21 (14%), and changes in medical regimen in 34 patients (22%). CONCLUSIONS: Push enteroscopy with video enteroscopes has a moderate diagnostic yield. Positive findings frequently lead to therapy changes. Large hiatal hernias remain an under-recognized etiology of anemia. Repeat upper endoscopy should be considered before enteroscopy in patients taking nonsteroidals who develop overt bleeding.

Adult↗
PubMed1998

Enteroscopy for the initial evaluation of iron deficiency.

BACKGROUND: Occult gastrointestinal blood loss is generally investigated with colonoscopy and esophagogastroduodenoscopy in patients with iron-deficiency anemia. The aim of this study was to prospectively measure the additional diagnostic yield of examining the jejunum at the time of upper endoscopy in patients with iron-deficiency anemia. METHODS: Asymptomatic patients with newly diagnosed iron-deficiency anemia who had no identifiable source of blood loss at colonoscopy underwent standard esophagogastroduodenoscopy with the Olympus SIF100L enteroscope followed by overtube-assisted enteroscopy. Upper tract and jejunal sources of blood loss were noted. Biopsy samples from the small bowel were taken when a bleeding lesion was not identified. RESULTS: Thirty-one consecutive patients (13 men, mean age 71) with no gastrointestinal symptomatology were studied. Eleven patients (35%) had a bleeding source that required only esophagogastroduodenoscopy for identification; 8 patients (26%) had a source only in the jejunum; 2 patients (6%) (one with sprue) had a source in upper tract as well as jejunum. The enteroscopy was rated as causing minimal or mild discomfort in 25 of 31 patients (81%). Using Medicare reimbursement figures, a strategy of performing esophagogastroduodenoscopy first would have cost $656 per patient, whereas the strategy of performing esophagogastroduodenoscopy with enteroscopy as the initial test in all patients costs $467 per patient. CONCLUSIONS: Performance of push enteroscopy along with esophagogastroduodenoscopy increases the diagnostic yield from 41% to 67% when evaluating the upper gastrointestinal tract of asymptomatic patients with iron-deficiency anemia and, because of a lower cost, should be the preferred initial diagnostic test.

Aged↗
PubMed1998

Determination and validation of a predictive model for Clostridium difficile diarrhea in hospitalized oncology patients.

BACKGROUND: Clostridium difficile colitis in the cancer patient receiving chemotherapy is a frequent cause of morbidity which may prolong hospitalization. Techniques for identifying infection often delay the initiation of therapy. PATIENTS AND METHODS: In this retrospective case-control analysis, we identified predictors for C. difficile-associated diarrhea in 29 patients hospitalized from 1988 to 1993 on a hematologic malignancy/bone marrow transplant unit (hospital A). We then validated our model with 58 C. difficile cases and 74 controls admitted to an oncology unit from a different institution (hospital B). RESULTS: We found that low intensity of chemotherapy (P < 0.001), lack of parenteral vancomycin use (P = 0.03) and hospitalization within the past two months (P = 0.05) were independently predictive of C. difficile colitis by multivariate analysis. These variables were weighted for predictive capability using a receiver operator characteristic score; low intensity chemotherapy was assigned two points, lack of parenteral vancomycin received one point and prior hospitalization one point (P < 0.001 by chi 2 for trend). The receiver operating characteristic (ROC) curve areas were 0.78 for patients at hospital A and 0.70 at hospital B indicating moderate drop off in discrimination. Compared to hospital A patients, hospital B patients hospitalized between 1989 and 1994 were more often women (P = 0.04), received less systemic vancomycin (P = 0.01), were less frequently neutropenic (P < 0.05), and received less intense chemotherapy regimens (P < 0.05). Despite these differences in demographics in patients between these institutions, our predictive model was validated in hospital B patients (P = 0.02 by chi 2 for trend). CONCLUSIONS: The results of this study may help clinicians predict the risk of C. difficile disease in the hospitalized immunocompromised oncology patient and may help guide empiric therapy while awaiting results of stool toxin assays.

Case-Control Studies↗
PubMed1998

The effectiveness of early endoscopy for upper gastrointestinal hemorrhage: a community-based analysis.

OBJECTIVES: The effectiveness of upper endoscopy in unselected patients with upper gastrointestinal hemorrhage has not been well studied. This study was undertaken to identify factors associated with the performance of early endoscopy (ie, within 1 day of hospitalization) and, after adjusting for these factors, to determine associations between early endoscopy and in-hospital mortality, length of stay, and performance of surgery. METHODS: Subjects in this observational cohort study were 3,801 consecutive admissions with upper gastrointestinal hemorrhage to 30 hospitals in a large metropolitan region. Demographic and clinical data were abstracted from hospital records. A multivariable model based on factors that potentially could relate to the decision to perform endoscopy was developed to determine the propensity (0 to 100%) for early endoscopy in each patient. RESULTS: Early endoscopy was performed in 2,240 patients (59%), and although it was not associated with mortality after adjusting for severity of illness among all patients, it was associated with a higher risk of death for patients in the lowest propensity group. Early endoscopy was associated with a lower likelihood of upper gastrointestinal surgery in all patients and in the two highest propensity groups and with a shorter length of stay in the entire cohort and in all subgroups. CONCLUSIONS: In the absence of specific contraindications, early endoscopy should be considered because of associated reductions in length of stay and surgical intervention. Further studies are needed to identify subgroups in whom the procedure may be associated with adverse effects on survival.

Adult↗