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Biomedical subjects

B T Petersen

Publications and source records attributed to B T Petersen.

At least 37 records · Page 2Linked to original sources
PubMed2000

Endoscopic therapy of anastomotic bile duct strictures occurring after liver transplantation.

BACKGROUND: Optimal therapy for anastomotic biliary strictures occurring after orthotopic liver transplantation (OLT) remains to be defined. We reviewed our experience with endoscopic therapy for such strictures and contrasted it with reported data. METHODS: Endoscopic therapy was performed with balloon dilation alone; no patients received an endoprosthesis. Responses were characterized as good if the patient improved clinically and no subsequent procedures were required after one or more dilations within a 3-month period; partial if clinically significant obstruction resolved but cholestasis persisted or there was a need for further endoscopic management beyond the initial 3 months; poor if subsequent surgery or percutaneous procedures were required; and failed if endoscopic access or dilation could not be accomplished. RESULTS: Fifteen patients underwent 23 endoscopic retrograde cholangiopancreatographies for post-OLT anastomotic strictures. Postprocedure follow-up averaged 25.2 months. Cholangiography was successful in all 23 procedures; free duct access was achieved in 22 of 23 procedures. The strictures were successfully accessed for dilation in 11 of 15 patients and in 19 of 23 procedures. Outcome was deemed good in 4 (27%), partial in 3 (20%), and poor in 5 (33%) patients. Endoscopic therapy failed in 3 (20%). Poor outcomes were due to the early recognition of severe lesions (2 treated surgically) or to short-term responses to dilation alone (3). The procedural complication rate of 17.4% included 3 episodes of transient cholangitis (i.e., elevation of liver enzymes associated with fever that lasted less than 3 days) and 1 self-limited episode of postsphincterotomy bleeding, which required the transfusion of 2 units packed red blood cells. In published series the combined success rate of balloon dilation alone for treatment of anastomotic strictures is 41%, whereas for dilation plus stent placement it is 75%. CONCLUSION: Endoscopic balloon dilation alone is not a reliable method of therapy for anastomotic strictures occurring after OLT. Dilation followed by short- to intermediate-term stent placement appears to provide a more durable result.

Adolescent↗
PubMed2000

Magnetic resonance cholangiography in patients with biliary disease: its role in primary sclerosing cholangitis.

BACKGROUND/AIM: Magnetic resonance cholangiography (MRC) is a non-invasive diagnostic procedure whose role in the management of patients with primary sclerosing cholangitis (PSC) is unclear. The aim of this study was to determine the usefulness of MRC in the evaluation of the biliary tree in patients with suspected biliary disease, and in particular, PSC. METHODS: MRC and invasive cholangiography (ERCP or PTC) were both performed in 73 patients, (33 male, 40 female, mean age 56 years) with clinical and/or biochemical evidence of cholestasis. Images were interpreted by two radiologists unaware of the results of other studies. RESULTS: Forty-two patients (58%) had benign biliary disease, including 23 patients (32%) with PSC; 9 patients (12%) had malignant biliary disease; and 22 patients (30%) had a normal biliary tree. Diagnostic quality images were obtained in 73/73 (100%) of MRC, and in 70/73 (96%) of invasive cholangiography (68 ERCP's, 2 PTC's) procedures. Using ERCP/PTC findings as the reference standard, MRC had an accuracy greater than 90% in the diagnosis of normal bile ducts, biliary dilatation, biliary obstruction, bile duct stones, and PSC. Using the final diagnosis, MRC had an overall diagnostic accuracy of 90% in the detection of biliary disease compared to 97% for invasive cholangiography. Additional diagnostic/therapeutic interventions were performed during ERCP in 73% of patients with PSC and in 43% of patients without PSC (p=0.02). CONCLUSIONS: MRC has excellent diagnostic accuracy in the presence of biliary disease. Because of its noninvasive nature, MRC may have advantages over invasive cholangiography when diagnosis is the major goal of the procedure.

Adult↗
PubMed2000

Advantages of disposable endoscopic accessories.

Despite the prevailing emphasis on falling reimbursements and cost containment, the use of disposable endoscopic accessories has grown tremendously. They offer simplicity of use, certain sterility, and reduced labor costs in exchange for higher purchase costs per procedure and the burden of waste disposal. Disposable accessories provide greater variety, complexity, and utility. They carry a cost burden that may be acceptable when the devices are difficult to reprocess, when they incorporate features that justify the added cost, or when their unit cost approaches purchase plus reprocessing costs for reusable alternatives, such as for biopsy forceps. Units with small volumes may prefer the ease of disposable accessories independent of relative cost issues, while large high-volume units may need to evaluate cost data more carefully to maintain sustainable practices.

Cost-Benefit Analysis↗
PubMed2000

Diagnosis and therapy of biliary tract malignancy.

Bile duct and gallbladder cancer are relatively uncommon. Predisposing factors include primary sclerosing cholangitis and gallstones larger than 3 centimeters. Patients present with signs of biliary obstruction and cholestasis. A serum CA 19-9 elevated above 100 U/mL is a useful marker. The diagnosis is implied on imaging studies and confirmed by tissue obtained at endoscopic retrograde cholangiopancreatography or surgery, or by the clinical course. Surgery is the only curative therapy and survival is improved with resection of early stage disease. Endoscopic or percutaneous transhepatic stenting provides effective palliation. Generally, survival is less than 1 year.

Aged↗
PubMed1999

Management and long-term prognosis of Dieulafoy lesion.

BACKGROUND: The Dieulafoy lesion is an important cause of gastrointestinal (GI) hemorrhage. Optimal treatment and long-term outcome are unknown. This study aimed to characterize the presentation of the Dieulafoy lesion and to summarize the results and report the long-term outcome of endoscopic therapy. METHODS: Data regarding diagnosis, treatment and outcomes were derived from our GI Bleed Team database, patient records and follow-up correspondence. RESULTS: Ninety Dieulafoy lesions were identified in 89 patients after a mean of 1.9 endoscopies. Their mean age was 72 years. Thirty-four percent of lesions were extragastric. Median transfusion requirement was 5 units. Two patients exsanguinated and 3 required surgery; all others were initially successfully treated endoscopically (with or without epinephrine injection): heat probe (71 patients), band ligation (3), hemoclip (1), laser (2), bipolar probe (4), sclerotherapy (2) and epinephrine alone (2). Gastric perforation occurred in 1 patient following sclerotherapy. Thirty-day mortality was 13%, 4 related to hemorrhage and 5 related to comorbidity. During median follow-up of 17 months, 34 patients (42%) died. One patient had recurrent bleeding 6 years after operation. CONCLUSIONS: Dieulafoy lesion is relatively common and often extragastric. Endoscopic therapy is safe and effective. Long-term recurrence was not evident following endoscopic ablation. Follow-up after ablative therapy appears unnecessary.

Adult↗
PubMed1999

Interventional treatment of acute and chronic pancreatitis. Endoscopic procedures.

The role of therapeutic endoscopy in the treatment of acute and chronic pancreatitis has expanded dramatically over the past 10 years. Drainage of pseudocysts and even organized pancreatic necrosis when localized are becoming commonplace. Other areas in which therapeutic endoscopy has been shown to be efficacious include severe biliary pancreatitis, pancreatic duct disruptions, strictures, and obstructive calculi. Its role in the management of acute recurrent pancreatitis with presumed Oddi's sphincter dysfunction or pancreas divisum continues to be defined. The cost-effectiveness and minimally invasive nature of endoscopic therapy compared with surgery should ensure the continued development of these techniques. More controlled, prospective data are required.

Acute Disease↗
PubMed1999

Spiral nitinol biliary stents in a porcine model: evaluation of the potential for use in benign strictures.

BACKGROUND AND STUDY AIMS: Self-expanding spiral nitinol stents are potentially removable and may be useful in the treatment of benign strictures. We evaluated the histologic response to stent placement and technical aspects of their placement and removal in a porcine model. METHODS: Nine animals were studied. Stents were placed above the papilla in six surviving animals. After intervals of one, two or three months cholangiography and attempted stent removal was performed. Four animals were then sacrificed acutely with their stent in place, and two were sacrificed after a one-month healing interval. The results of placement, follow-up cholangiography and histology are reported. RESULTS: Cholangiography and stent placement succeeded in 26 of 27 and 11 of 16 attempts, respectively. Three placement failures were attributed to stent/duct size disparity or a faulty release mechanism, resulting in stent kinking and/or duct twisting. Among the successfully deployed stents, two animals developed strictures where stents traversed bifurcations and one exhibited partial luminal compromise by tissue entrapment between coils. Fluoroscopically guided removal was successful in two of five stents positioned above the papilla. Histology was non-specific but minimally changed in those given a one-month healing interval after removal. Others exhibited moderate inflammation, fibrosis and an intramural abscess at sites of induced stricture. CONCLUSIONS: Spiral metal stents for the treatment of benign strictures remain experimental. Care must be taken to deploy them in bile ducts of adequate diameter and endoscopic removal is not yet demonstrably reliable and safe.

Alloys↗
PubMed1998

The evolving role of endoscopic retrograde cholangiography before and after cholecystectomy.

Laparoscopy is the preferred approach for cholecystectomy; however the indications for pre- versus postoperative endoscopic retrograde cholangiography (ERC) are still evolving. The records of patients who had ERC performed one month before (n = 119) or after (n = 35) laparoscopic or open cholecystectomy from January 1990 to August 1992 (period 1), and 66 patients who had preoperative ERC from November 1995 to October 1996 (period 2) are reviewed, ERC indications, findings and outcomes were reviewed, and trends in the use of preoperative ERC from 1990 to 1996 were sought. Between periods 1 and 2 the yield of preoperative ERC increased from 36% to 58% (P < 0.01). The use of preoperative ERC for the indication of abnormal liver enzymes declined (P < 0.05), while the yield increased (25% versus 61%, P < 0.01). Both the use of ERC and the yield remained stable for other indications. ERC was felt to have changed the surgical approach in 5% of patients. Primary indications for postoperative ERC (n = 35) included abnormal intraoperative cholangiography (43%), liver function test abnormalities (23%) and recurrence of preoperative symptoms (14%); stones were found in 60%, 50% and 20% of patients with these indications, respectively. Overall, 46% of postoperative studies revealed duct stones. The roles for pre- and postoperative ERC are changing and depend greatly on the relative laparoscopic and endoscopic expertise at a given institution.

Adolescent↗
PubMed1997

Transdermal nicotine for mildly to moderately active ulcerative colitis. A randomized, double-blind, placebo-controlled trial.

BACKGROUND: Ulcerative colitis is predominantly a disease of nonsmokers. Transdermal nicotine may help control clinical manifestations of this condition. OBJECTIVE: To determine the efficacy of transdermal nicotine for controlling clinical disease activity in active ulcerative colitis. DESIGN: Randomized, double-blind, placebo-controlled, single-center clinical trial. SETTING: Multispecialty group serving as an academic tertiary referral center. PATIENTS: 64 nonsmoking patients with mildly to moderately active ulcerative colitis despite the use of medication. INTERVENTION: Patients were stratified on the basis of smoking history, extent of disease, and concomitant medical therapy. After stratification, patients were randomly assigned to daily treatment with transdermal nicotine (n = 31) at the highest tolerated dose (11 mg for 1 week and then < or = 22 mg for 3 weeks) or placebo (n = 33). MEASUREMENTS: Clinical features were assessed at baseline and 4 weeks by endoscopy, physician assessment, and a patient diary of daily symptoms. Serum concentrations of nicotine were determined by using gas chromatography and mass spectrometry, and plasma concentrations of cotinine were measured by using high-performance liquid chromatography. RESULTS: At 4 weeks, 12 of 31 patients (39%) who received nicotine showed clinical improvement compared with 3 of 33 patients (9%) who received placebo (P = 0.007). Four patients receiving nicotine discontinued therapy because of side effects (contact dermatitis [n = 2], nausea [n = 1], and acute pancreatitis [n = 1]). At week 4, the nicotine group had a mean (+/-SD) trough serum nicotine concentration of 11.3 +/- 8.4 ng/mL and a mean trough plasma cotinine concentration of 192 +/- 95 ng/mL. CONCLUSIONS: Transdermal nicotine administered at the highest tolerated dosage (< or = 22 mg/d) for 4 weeks is efficacious for controlling clinical manifestations of mildly to moderately active ulcerative colitis.

Administration, Cutaneous↗
PubMed1996

Endoscopic decompression for acute colonic pseudo-obstruction.

BACKGROUND: Acute colonic pseudo-obstruction is often treated by colonoscopic decompression. Efficacy, safety, and outcome of endoscopic decompression was assessed. METHODS: Colonoscopic decompressions from 1988 to 1994 were reviewed. Resolution without further endoscopic intervention was defined as clinical success. RESULTS: Acute colonic pseudo-obstruction was diagnosed in 50 patients. Thirty-three cases followed surgery or trauma and 17 developed during severe medical illness. Orthopedic joint surgery was most common. Nineteen of 50 patients (38%) had severe underlying medical disease. Forty-one patients (82%) had one colonoscopic decompression with clinical success in 39 (95%). Nine patients (18%) required multiple (2 to 4) colonoscopic decompressions with clinical success in 5 (56%). A decompression tube positioned in the right colon (57%) and in the transverse colon (33%) had similar clinical success. In 8 procedures a decompression tube was not placed, with poor clinical success (25%). The overall clinical success of colonoscopic decompression was 88% (44 of 50). An endoscopic perforation occurred in 1 patient (2%). Overall hospital mortality was 30%. CONCLUSIONS: Colonoscopic decompression is effective and safe for acute colonic pseudo-obstruction that does not respond to conservative therapy. Most patients will respond to one colonoscopic decompression with decompression tube placement. Complete colonoscopy and cecal tube placement is unnecessary.

Acute Disease↗
PubMed1996

Pancreatitis secondary to percutaneous liver biopsy-associated hemobilia.

Hemobilia refers to hemorrhage in the biliary tree and is most commonly associated with accidental and iatrogenic trauma. Rarely has pancreatitis been reported in association with hemobilia and never as a consequence of percutaneous liver biopsy-induced hemobilia. We report the case of a 64-yr-old man who presented with pancreatitis 6 days after a percutaneous liver biopsy. Within 24 h of admission, he developed hematochezia. Emergency endoscopy was performed, and with a side-viewing duodenoscope, blood and clot were clearly seen oozing from the papilla. The origin of bleeding was identified angiographically as a pseudoaneurysm of the right hepatic artery. Bleeding stopped and pancreatitis resolved after angiographic embolization of the hepatic artery pseudoaneurysm. A review of the English language literature reveals eight well-documented cases of pancreatitis associated with hemobilia, including the current report. Seven cases were associated with ruptured hepatic artery aneurysms and one case with hemorrhagic acalculous cholecystitis. Six of the patients received appropriate therapy to stop bleeding and recovered uneventfully. Pancreatitis should be recognized as a potential important complication of hemobilia. In addition, hemobilia should be considered in the differential diagnosis for those patients with apparent biliary or idiopathic acute pancreatitis and no stones seen on ultrasonography. When bleeding is stopped via surgical or radiological methods, the clinical course of hemobilia-associated pancreatitis appears to be benign.

Biopsy, Needle↗
PubMed1992

Acute gastrointestinal bleeding. Experience of a specialized management team.

The initial experience of a specialized management team organized to provide expedient care for all acute major gastrointestinal bleeding in protocolized fashion at a large referral center is presented. Of the 417 patients, 56% developed bleeding while hospitalized. Upper gastrointestinal bleeding accounted for 82%. The five most common etiologies included gastric ulcers (83 patients), duodenal ulcers (67 patients), erosions (41 patients), varices (35 patients), and diverticulosis (29 patients). Nonsteroidal anti-inflammatory drugs were implicated in 53% of gastroduodenal ulcers. The incidence of nonbleeding visible vessels was 42% in gastric and 54% in duodenal ulcers. The rates of rebleeding were 24% (20 patients) in gastric ulcers and 28% (19 patients) in duodenal ulcers. Predictive factors for rebleeding included copious bright red blood, active arterial streaming, spurting, or a densely adherent clot. The rebleeding rate for esophagogastric varices was 57%. The mortality rate overall was 6% (27 patients), with rates varying from 3% (five patients) for gastroduodenal ulcers to 40% (14 patients) for esophagogastric varices. The morbidity rate for the entire patient population was 18% (77 patients), dominated by myocardial events (34 patients). The average length of hospitalization for gastroduodenal ulcers was 5 days, for diverticulosis 8 days, and for varices 10 days. The major efforts of a specialized Gastrointestinal Bleeding Team would be best directed at both reducing the morbidity associated with acute bleeding and reducing the overall cost of care.

Adolescent↗