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Biomedical subjects

M V Sivak

Publications and source records attributed to M V Sivak.

At least 19 recordsLinked to original sources
PubMed1992

Localization of pancreatic endocrine tumors by endoscopic ultrasonography.

BACKGROUND: After a pancreatic endocrine tumor has been diagnosed on the basis of clinical signs and the results of laboratory tests, localization of the tumor by the usual imaging procedures fails in as many as 40 to 60 percent of patients. Endoscopic ultrasonography, a sensitive test for small carcinomas of the pancreas, might also be useful in patients with endocrine tumors of the pancreas that cannot be localized by conventional methods. METHODS: We studied 37 patients later shown to have 39 endocrine tumors of the pancreas who had negative results on transabdominal ultrasonography and CT. All the patients underwent endoscopic ultrasonography, and 22 also underwent selective angiography. All the tumors were confirmed by surgical excision and immunohistologic examination; they consisted of 31 insulinomas, 7 gastrinomas, and 1 glucagonoma, 0.5 to 2.5 cm (mean, 1.4 cm) in diameter. All but one of the patients were cured of their disease, as ascertained by at least six months of clinical and laboratory follow-up. RESULTS: Using endoscopic ultrasonography, we were able to localize 32 of the 39 tumors (sensitivity, 82 percent); no tumor was incorrectly localized. The size of the tumors was very similar (within 2 mm) to that predicted by endoscopic ultrasonography. Among the 22 patients who underwent both angiography and endoscopic ultrasonography, ultrasonography was significantly more sensitive than angiography for tumor localization (sensitivity, 82 percent vs. 27 percent). Among 19 control patients without pancreatic endocrine tumors, endoscopic ultrasonography was negative in 18 (specificity, 95 percent). CONCLUSIONS: Endoscopic ultrasonography is a highly sensitive and specific procedure for the localization of pancreatic endocrine tumors. It should be considered for the preoperative localization of such tumors once the clinical and laboratory diagnosis has been established.

Adenoma, Islet Cell↗
PubMed1992

Gastroduodenal polyps in patients with familial adenomatous polyposis.

A review of the endoscopy reports and pathology results from esophagogastroduodenoscopy (EGD) of all patients with familial adenomatous polyposis (FAP) undergoing such an examination was performed. Two hundred forty-seven patients were identified, with an overall prevalence of duodenal adenomas of 66 percent and of fundic gland polyps of 61 percent. Analysis of our more recent experience (1986 to 1990) shows the prevalence to be 88 percent and 84 percent, respectively. A normal-appearing papilla was adenomatous in 50 percent of cases. No case of periampullary carcinoma developed in patients under surveillance. Routine EGD is indicated for patients with FAP. Duodenal adenomas and fundic gland polyps will occur in the majority of patients.

Adenomatous Polyposis Coli↗
PubMed1992

Esophageal carcinoma: esophageal ultrasound assessment of preoperative chemotherapy.

The effect of preoperative chemotherapy in the treatment of esophageal carcinoma is difficult to assess because of the inadequacies of clinical staging. Endoscopic esophageal ultrasound (EUS) has been shown to be accurate in the clinical determination of depth of tumor invasion (T) and regional lymph node status (N). Therefore, EUS may be useful in assessing the effect of preoperative chemotherapy in the treatment of esophageal carcinoma. Eleven patients with operable adenocarcinoma of the esophagus or esophagogastric junction underwent staging by EUS before treatment. This was followed by two courses (10 patients) or one course (1 patient) of chemotherapy: etoposide, 120 mg/m2 for 3 days; doxorubicin hydrochloride, 20 mg/m2; and cisplatin, 100 mg/m2. Restaging by EUS was done after treatment. Ten patients then underwent resection of the tumor with lymphadenectomy. One patient was found to have metastatic disease at thoracotomy and did not undergo resection. However, tissue sampling was adequate for the determination of pathological stage. Independent pathological determinations of T and N were then obtained. On completion of chemotherapy, 9 patients (82%) had relief or reduction of preoperative symptoms, and 9 patients (82%) had either no evidence of tumor or reduction of tumor size by endoscopy. Despite this clinical and endoscopic response, no patient had EUS-documented and pathology-confirmed reduction of T. However, 2 patients had EUS-documented and pathology-confirmed progression of N. The accuracy of EUS in the determination of T was 82% and of N, 73%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1992

Endoscopic ultrasonography in the diagnosis of chronic pancreatitis.

Endoscopic ultrasonography (EUS) is highly accurate in the diagnosis of chronic pancreatitis. Both parenchymal and ductal changes indicative of chronic pancreatitis can be identified. Parenchymal changes include small cystic abnormalities and hyperechoic foci scattered throughout the gland; the entire gland may be enlarged in early chronic pancreatitis, or small and atrophic in advanced disease. Ductal changes include enlargement of the main pancreatic duct or secondary branches, and the presence of stones or proteinaceous plugs within the ducts. Pseudocysts appear as cystic structures of mixed echogenicity; EUS is able to detect small pseudocysts or masses not identified by conventional imaging modalities. EUS has some difficulty in distinguishing benign from malignant pancreatic masses, particularly when the lesions are small. EUS should not supplant the use of CT scan or ERCP in the differential diagnosis of pancreatic disease, but is rather an adjunct to these studies. Future clinical research should focus on determining the appropriate indications for EUS in pancreatic disease, and determining if patient outcomes are favorably affected by the diagnostic information obtained.

Chronic Disease↗
PubMed1992

Giant duodenal gallstone presenting as gastric outlet obstruction: Bouveret's syndrome.

In a 91 year old woman with nausea and vomiting, the diagnosis of Bouveret's syndrome was considered when a barium meal disclosed a cholecystoduodenal fistula and a giant filling defect in the duodenum. Because of her age and underlying medical illness, operative therapy was initially deferred. Repeated attempts to remove the intermittently obstructing duodenal gallstone endoscopically were unsuccessful using both endoscopic retrograde cholangiopancreatography retrieval baskets and an endoscopic mechanical lithotripter. The patient was referred for definitive operative therapy, and was discharged after a successful and uneventful enterolithotomy.

Aged↗
PubMed1992

Gastric perforation after endoscopic treatment of a Dieulafoy's lesion.

Dieulafoy's vascular malformation is an underdiagnosed cause of massive, often recurrent upper gastrointestinal hemorrhage. Attempted endoscopic treatment of Dieulafoy's lesion has been recommended prior to surgery in many instances, but may occasionally be employed as primary therapy in patients that are not considered good "operative risks." Although generally considered safe and effective therapy for nonvariceal hemorrhage, combination therapy by injection and thermocoagulation techniques may result in perforation. We present a patient with a Dieulafoy's lesion of the stomach that illustrates both the efficacy and risks of combination endoscopic therapy for nonvariceal gastrointestinal hemorrhage.

Arteriovenous Malformations↗
PubMed1991

Hyperplastic polyps seen at sigmoidoscopy are markers for additional adenomas seen at colonoscopy.

Asymptomatic individuals undergoing screening flexible sigmoidoscopy were prospectively studied. Polyps were found in 185 subjects. The endoscopist recorded an opinion on the polyps' histology based on endoscopic appearance. No polyps were removed at sigmoidoscopy. All subjects with rectosigmoid polyps then underwent colonoscopy and polypectomy. Of them, 99 subjects (54%) had at least one rectosigmoid adenoma, 69 (37%) had only hyperplastic polyps, and 17 (9%) had other findings. The endoscopists' opinion of the histopathology of polyps at sigmoidoscopy was correct for 61% of the lesions. Of subjects with adenomatous rectosigmoid polyps, 29% had additional adenomas at more proximal sites. Proximal adenomas were found in 28% of patients with hyperplastic rectosigmoid polyps. Patients with rectosigmoid hyperplastic polyps had the same risk for additional proximal adenomas as patients with rectosigmoid adenomatous polyps.

Adult↗
PubMed1991

Esophageal ultrasound and the preoperative staging of carcinoma of the esophagus.

Esophageal ultrasound allows the esophageal wall to be viewed as five discrete layers. Lymph nodes are easily identified, and their size, shape, margin, and internal structure can be assessed. This provides an alternative method of preoperative (clinical) evaluation of the primary tumor [T] and the regional lymph nodes [N] of patients with carcinoma of the esophagus. Esophageal ultrasound was attempted in the clinical staging of 28 patients with carcinoma of the esophagus. Six patients (21%) were not assessed because of the inability to pass the esophageal ultrasound probe through the malignant stricture. The staging system for carcinoma of the esophagus developed by the International Union Against Cancer and the American Joint Committee on Cancer was used. Twenty-two patients had the true T determined by pathologic review of the resected esophagus. Esophageal ultrasound correctly identified T in 13 patients (59% accuracy). In four patients (18%) the disease was overstaged by esophageal ultrasound; all these patients had early T1 tumors confined to the submucosa. In five patients (23%) the disease was understaged by esophageal ultrasound; all of these patients had advanced tumors (four T3 and one T4) that invaded beyond the esophageal wall. Seven of the nine incorrect esophageal ultrasound determinations were called T2 (three T1, three T3, one T4), which suggests that the borders of the muscularis propria require careful attention when evaluated by esophageal ultrasound. Twenty patients had the true N determined by pathologic review of the resected specimen. Esophageal ultrasound correctly identified N in 14 patients (70% accuracy). Three patients were falsely identified as having N1 disease and three were falsely identified as having N0 disease. The sensitivity, specificity, positive predictive value, and negative predictive value for N assessment by esophageal ultrasound were 70%. Esophageal ultrasound provides an alternative method of visualization of the esophageal wall and regional lymph nodes. Our early experience shows promise for esophageal ultrasound in the clinical staging of carcinoma of the esophagus.

Aged↗
PubMed1989

Endoscopic management of bile duct stones.

Endoscopic sphincterotomy is the procedure of choice for choledocholithiasis in patients who have had a cholecystectomy. The bile duct is cleared of stones in about 80 to 90 percent of patients. Available data, largely retrospective, suggest that surgery and endoscopic sphincterotomy are about equal with respect to removal of stones, morbidity, and mortality. Certain technical problems are discussed, including inability to insert the papillotome, the large stone, and problems relating to anatomy such as peripapillary diverticulum and prior gastrectomy. The treatment of patients with bile duct stones who have not had a cholecystectomy, with and without cholelithiasis, is controversial. Endoscopic sphincterotomy without subsequent cholecystectomy is adequate treatment for the majority of patients who are unfit for surgery, even if there are stones in the gallbladder, provided they are asymptomatic after endoscopic removal of stones from the bile ducts. Endoscopic sphincterotomy has been performed in the treatment of gallstone-induced pancreatitis, acute obstructive cholangitis, and sump syndrome. The complication rate for endoscopic sphincterotomy ranges from 6.5 to 8.7 percent, with a mortality rate of 0 to 1.3 percent. The most common serious complications are perforation, hemorrhage, acute pancreatitis, and sepsis.

Acute Disease↗