Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Michael V. Sivak is active.

Publication


Featured researches published by Michael V. Sivak.


Gastroenterology | 1985

Surveillance for colonic carcinoma in ulcerative colitis

Eric Rosenstock; Richard G. Farmer; Robert E. Petras; Michael V. Sivak; George B. Rankin; B.H. Sullivan

To evaluate the efficacy of surveillance colonoscopy with biopsy for the detection of high-grade dysplasia (HGD) or colonic carcinoma in patients with chronic ulcerative colitis, we undertook a retrospective review of 248 patients who underwent 370 examinations (mean duration of disease 12 yr). High-grade dysplasia or carcinoma was found in 24 examinations in 16 patients, with a mean duration of disease of 16 yr. There were 15 patients with HGD. Nine patients had HGD alone, 6 had HGD and carcinoma, and 1 had carcinoma without HGD. The overall incidence of HGD was 6%. Dysplasia-associated lesions or mass were the most consistent indicators of carcinoma, the combination being present in four instances. Of the 7 patients with cancer, 6 were recognized by colonoscopy, and 1 patient with negative visual endoscopic findings was discovered using surveillance biopsies. The conclusions of this study are that dysplasia is a reliable histopathologic marker and correlates with the presence of cancer in chronic ulcerative colitis; the absence of dysplasia correlates with the absence of cancer. The presence of dysplasia-associated lesions or mass with HGD is the strongest indication for operation. This study supports the use of surveillance colonoscopy in managing high-risk ulcerative colitis patients.


Gastroenterology | 1986

When is endoscopic polypectomy adequate therapy for colonic polyps containing invasive carcinoma

James P. Cranley; Robert E. Petras; William D. Carey; Kathy Paradis; Michael V. Sivak

We correlated the histopathology with outcome for all patients with endoscopically removed colonic polyps containing invasive adenocarcinoma seen at our institution over a 10-yr period. Invasion was defined as infiltration of malignant cells into the submucosa. Of a total of 1523 adenomatous polyps, 41 polyps (2.7%) in 39 patients contained invasive adenocarcinoma. One patient was excluded from further analysis because of a synchronous colonic carcinoma. Fourteen patients (37%) had favorable histologic features (grade I or grade II carcinoma with free margin of resection and absence of lymphatic invasion), and none developed metastatic carcinoma during the follow-up period (mean 6.5 yr, range 4-10.6 yr). Twenty-four (63%) had unfavorable histologic features (grade III tumor with tumor at or near the margin of resection or lymphatic invasion), and 10 of these (42%) had either residual local or metastatic carcinoma in subsequent operations or during the follow-up period. This difference in outcome was statistically significant (p less than 0.05) when compared with the outcome of the group with favorable histology. We conclude that endoscopic polypectomy is adequate therapy for colonic polyps containing invasive carcinoma, provided that the favorable histologic features are present.


Gastrointestinal Endoscopy | 1991

Evaluation of submucosal upper gastrointestinal tract lesions by endoscopic ultrasound

Gregory A. Boyce; Michael V. Sivak; Thomas Rösch; Meinhard Classen; David Fleischer; H. Worth Boyce; Charles J. Lightdale; Jose F. Botet; Robert H. Hawes; Glen A. Lehman

The proper diagnosis of submucosal upper gastrointestinal tract mass lesions by endoscopy or barium study is difficult. Differentiation between submucosal tumors, vascular structures, and extrinsic organs is often impossible. We performed endoscopic ultrasound examination of 91 patients with upper gastrointestinal submucosal mass lesions. Endoscopic ultrasound was accurate in determining the site of origin in 48 of 50 cases where pathology or angiography comparison was available. Leiomyoma, lipoma, varices, and carcinoma had characteristic ultrasonographic findings. Endoscopic ultrasound is a useful procedure in the evaluation of upper gastrointestinal submucosal mass lesions.


Diseases of The Colon & Rectum | 1992

Gastroduodenal polyps in patients with familial adenomatous polyposis

James M. Church; Ellen McGannon; Sharon Hull-Boiner; Michael V. Sivak; Rosalind U. van Stolk; David G. Jagelman; Victor W. Fazio; John R. Oakley; Ian C. Lavery; Jeffrey W. Milsom

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 fortyseven 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.


Annals of Surgery | 1988

Villous tumors of the duodenum.

Susan Galandiuk; Robert E. Hermann; David G. Jagelman; Victor W. Fazio; Michael V. Sivak

Records of 32 patients with 34 villous and tubulovillous adenomas of the duodenum, treated at the Cleveland Clinic over the past 21 years, were reviewed. Twenty-two patients (69%) had complete resection of the adenoma; the incidence of malignancy was 47%. Five patients underwent a Whipple procedure; 4 patients had segmental resection of the duodenum; 12 had wide local excision of the adenoma; 1 had both a segmental resection and a local excision for two separate adenomas; and 5 patients had endoscopic excision alone. The remaining five patients underwent exploratory laparotomy alone or with palliative bypass procedures. A 28% recurrence rate was observed, all of these after segmental resection, local excision, or endoscopic excision. The highest recurrence rate was associated with local excision. The 2− and 5-year survival rates for patients with adenomas containing invasive cancer were 22% and 0%, respectively, compared to 87% and 87%, respectively, for benign adenomas (including those with carcinoma in situ). Twenty-two per cent of patients had intestinal polyposis syndromes. Duodenal adenomas were diagnosed a mean of 17 years after colectomy for polyposis, indicating the need for continued surveillance in these patients.


Gastrointestinal Endoscopy | 1989

Endoscopic ultrasonography in the differential diagnosis of pancreatic disease

Alien R. Kaufman; Michael V. Sivak

Endoscopic ultrasonography was performed in 25 patients with suspected pancreatic disease. Cancer of the pancreas was recognized in 9 of 10 cases with 1 false negative and 2 false positive diagnoses. Chronic pancreatitis was recognized in 89% of cases. Technical difficulties limited the success of the examination in 24% of cases. The presence or absence of pancreatic disease can be determined in most cases by endoscopic ultrasonography. Differential diagnosis by endoscopic ultrasonography (EUS) is correct in the majority of cases. We have not discovered any specific EUS finding(s) that are pathognomonic for pancreatic cancer or chronic pancreatitis.


Gastrointestinal Endoscopy | 1992

Endoscopic ultrasound in the pre-operative staging of rectal carcinoma

Gregory A. Boyce; Michael V. Sivak; Ian C. Lavery; Victor W. Fazio; James M. Church; Jeffrey W. Milsom; Robert E. Petras

Endoscopic ultrasound (EUS) was performed prospectively to stage 45 patients with rectal cancer. Patients were staged utilizing the TNM staging system. All patients subsequently underwent surgical resection with independent histopathologic staging. Depth of invasion was accurately predicted in 40 of 45 patients (89%). Presence or absence of lymph node metastasis was correctly determined in 34 of 45 patients (79%). EUS is an accurate method for local staging of rectal cancer.


Gastroenterology | 1985

Endoscopic Nd:YAG laser therapy as palliation for esophagogastric cancer

David M. Fleischer; Michael V. Sivak

Endoscopic neodymium:yttrium aluminum garnet laser therapy has been shown to be a technically feasible treatment option for relieving blockage in patients with malignant obstruction of the esophagus or gastric cardia. In an attempt to identify factors that would predict clinical benefit or risk, or both, 60 patients were evaluated retrospectively. Thirty-five patients (mean age 65.3 yr, range 47-89 yr) with biopsy-proven squamous cell carcinoma and 25 patients (mean age 61.1 yr, range 47-82 yr) with adenocarcinoma of the gastric cardia were evaluated. Most patients had had previous radiotherapy or surgery, and all had incurable disease. The following parameters were assessed: (a) tumor histology, (b) endoscopic appearance, (c) location, (d) clinical setting. There was no difference in response to treatment between squamous cell carcinoma and adenocarcinoma. Technically it was easier to treat mucosal tumors than to treat submucosal tumors. Also, the outcome was better in mucosal tumors. Results were least good and the technical difficulty greatest for tumors of the cervical esophagus. Tumors at the gastroesophageal junction were problematic if there was horizontal angulation. The best response occurred for tumors in a straight segment of mid-esophagus and distal esophagus, particularly if they were less than or equal to 5 cm in length. It is possible to identify parameters that affect the initial outcome.


Gastrointestinal Endoscopy | 1984

Colonoscopy with a VideoEndoscope: preliminary experience.

Michael V. Sivak; David Fleischer

A prototype VideoEndoscope was tested that does not have an optical fiber bundle. This was replaced by a sensing device in the instruments distal tip that transmits an image to a video processor for display on a television monitor. The television image was excellent, and the instrument system and its concept in general were thought to be acceptable for diagnostic and therapeutic colonoscopy. The instrument has unique advantages with regard to documentation, demonstration, and review of endoscopic findings.


American Journal of Surgery | 1989

Endoscopic management of bile duct stones

Michael V. Sivak

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.

Collaboration


Dive into the Michael V. Sivak's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Amitabh Chak

Case Western Reserve University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge