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Biomedical subjects

W M Thompson

Publications and source records attributed to W M Thompson.

At least 37 records · Page 2Linked to original sources
PubMed1992

Imaging of gastrointestinal malignancies.

Many advancements in the imaging of gastrointestinal malignancies have been seen in the past year. Endorectal ultrasound and magnetic resonance imaging with an endorectal surface coil allow for more accurate staging of the depth of bowel wall invasion by rectal carcinoma. Monoclonal antibody imaging may detect metastases not found by other modalities while computed tomography arterial portography and intraoperative ultrasound improve our ability to identify liver metastases. Endoscopic ultrasound is also useful in the preoperative assessment of esophageal cancer and pancreatic endocrine tumors.

Diagnostic Imaging↗
PubMed1991

Primary neoplasms of the hollow organs of the gastrointestinal tract. Staging and follow-up.

The number of imaging modalities available to stage and follow-up patients with primary neoplasms of the gastrointestinal (GI) tract continues to increase. Magnetic resonance imaging (MRI), computed tomography (CT), and ultrasonography are useful techniques for both staging and follow-up. For staging, CT is most frequently used for the detection of liver metastases and is increasingly used as a substitute for the chest radiograph in the detection of lung metastases. CT is still the imaging test of choice for the preoperative staging of esophageal carcinoma. CT is less helpful in staging the patient with gastric carcinoma or colorectal carcinoma. The current usefulness of MRI in the staging of GI tract malignancies is limited by the lack of an adequate oral intraluminal contrast agent and degradation of images due to motion. Sonography, especially the new technique of endoscopic ultrasound, is promising for the detection of local invasion from GI tract malignancies. CT is used in the follow-up of patients with tumors of the GI tract to detect liver, adrenal, and nodal metastases as well as local recurrence because of the ability of CT to detect extraluminal masses. CT of the pelvis has been recommended as a routine follow-up procedure in patients who have undergone abdominal-peroneal resection. Both CT and MRI can be used to detect local recurrence, but suffer from the inability to differentiate scar from recurrent tumor. The initial hope that MRI would be capable of differentiating postoperative scar tissue from recurrent tumor has not been realized. Therefore, with positive CT or MRI findings, occasionally a percutaneous biopsy will be required to confirm local recurrence.

Diagnostic Imaging↗
PubMed1991

Normal left ventricular function following pulmonary autograft replacement of the aortic valve in children.

To assess growth potential and hemodynamic sequelae of pulmonary autograft valves implanted into aortic outflow tracts of children, we reviewed our experience with 37 patients (2-21 years) from August 1986 to December 1990. Twenty patients had predominantly aortic stenosis (AS), and 17 had aortic insufficiency (AI). Operative mortality was 3%. Two technical failures required reoperation. Of survivors, six (18%) have moderate AI. Pre- and postoperative echocardiograms were reviewed. The AS group showed increased left ventricular (LV) cavity size by greater than 1-year follow-up, and decreased LV wall and interventricular septal thickness. In the AI group, wall and septal thickness increased by 10 days and LV cavity decreased by 10 days, 60 days, and greater than 1 year. Root replacements (n = 14) showed mean increases of 4.3 mm and 5.3 mm, respectively, in diameters of the aortic annulus and aortic sinuses at greater than 1 year. Intraaortic implants increased 3.1 mm (annulus) and 3.9 mm (sinuses) at greater than 1 year. The pulmonary autograft procedure is safe, and successful implantation normalizes LV dimensions and function rapidly. The autograft valve shows evidence of growth at greater than 1 year postoperative. The pulmonary autograft may be the ideal valve replacement in children.

Adolescent↗
PubMed1991

Imaging primary and metastatic cancer of the liver.

Either CT or MRI can be used as a primary screening test for liver masses in a patient with a known or suspected malignancy. A number of variations in techniques are available for both CT and MRI, and combinations of these techniques are often required to increase the detectability rate for hepatic lesions. Whether CT or MRI is chosen as an initial screening technique depends upon the particular patient and the institution. After a liver lesion has been identified, attempts should be made to obtain a specific diagnosis. Certain liver masses may have a specific CT appearance, especially when they are calcified. With some benign lesions a specific diagnosis is possible using imaging techniques, and in these instances CT and a supplemental radionuclide study may be of complimentary value. These include cavernous hemangioma, focal fatty liver, and focal nodular hyperplasia. Another group of lesions have a CT or an MRI appearance that is suggestive for a specific diagnosis, but may require confirmation with a biopsy or other tests. These include hepatoma, which may present as a mass with portal vein thrombosis, hepatic adenoma, which may appear as a mass with central hemorrhage, focal nodular hyperplasia may occur as a mass with a central stellate scar (on CT), or a cavernous hemangioma, which fulfills specific CT or MRI criteria. A final group of lesions consists of masses without a characteristic or suggestive CT or MRI appearance. These lesions will require biopsy for final diagnosis.

Humans↗
PubMed1990

Correction of truncus arteriosus with truncal valvar stenosis or insufficiency using two homografts.

Surgical correction of truncus arteriosus requires the creation of right ventricular to pulmonary artery continuity and closure of the ventricular septal defect. A variety of conduits have been used including valved and nonvalved. Despite a significant incidence of truncal valvar stenosis and insufficiency, this valve has seldom been replaced. We present 4 cases of truncus arteriosus with truncal valvar stenosis or insufficiency that were repaired using two valved homografts: one to create the pulmonary outflow tract and the other to replace the abnormal truncal valve. Two of these patients are doing well after 4 months. Another child survived the operation and did well for 2 months when she died suddenly. The last child died 14 hours postoperatively from low cardiac output syndrome secondary to diabetic hypertrophic cardiomyopathy. When truncal valvar abnormalities are present, the primary repair of truncus arteriosus in an infant should include replacement of the truncal valve. Total correction can be successfully achieved using two valved homografts, resulting in long-term palliation and freedom from thromboembolic events and the use of anticoagulants.

Abnormalities, Multiple↗
PubMed1990

Delayed detection of coarctation in infancy: implications for timing of newborn follow-up.

During a recent 5-year period, 74 patients younger than 6 months of age were diagnosed with coarctation of the aorta. Coarctation was correctly diagnosed in only 22% of patients prior to referral despite readily apparent femoral pulse abnormalities in 86%. Infants whose symptoms were detected between 5 and 14 days of age were significantly more ill than infants outside this age range and had a high mortality rate (25%). The number of associated cardiac defects was not related to the severity of clinical illness in this group, suggesting that closure of the ductus arteriosus is the primary determinate of disease severity. Observations in two patients suggested that a detectable pulse discrepancy occurs between 3 and 5 days postnatally. Upper extremity hypertension was found commonly in infants after 5 days of age despite the presence of congestive heart failure. Earlier detection of coarctation in the newborn requires a diligent cardiovascular and peripheral pulse examination between 3 and 7 days of life, upper extremity and lower extremity blood pressure measurement, and a high index of suspicion.

Age Factors↗
PubMed1989

Biliary complications after liver transplantation in children.

To evaluate the role of interventional radiologic procedures in the diagnosis and treatment of biliary complications in children after liver transplantation, the authors reviewed the cases of 58 pediatric patients who underwent transplantation over a 4-year period. In 21 patients suspected of having biliary complications, 31 diagnostic percutaneous transhepatic cholangiographic studies, 19 transhepatic biliary drainages, eight pressure-flow studies, five percutaneous drainages of abdominal fluid collections, 11 balloon dilations, and one basketing procedure were performed. Biliary complications were seen in 38% of allografts, with obstruction being more common than leakage. Complications were most frequent in patients with cholecystojejunostomy reconstructions. Only two children had biliary complications that were thought to be related to arterial compromise. No significant intervention was required in 17% of complications. Percutaneous techniques were associated with a low frequency of significant complications (6%). The authors conclude that interventional radiologic techniques can be used effectively in the evaluation and management of biliary complications in pediatric hepatic transplant recipients.

Catheterization↗
PubMed1989

CT of esophageal neoplasms.

Considerable controversy surrounds the use of computed tomography (CT) in the staging of esophageal carcinoma. New evidence suggests that CT is extremely useful in the selection of patients who may benefit from surgery and/or adjuvant therapy. Additionally, CT can also plan the most efficacious surgical approach. The principles and problems of staging esophageal carcinoma are discussed and useful criteria are presented.

Esophageal Neoplasms↗
PubMed1988

Perforated gastric ulcers. A plea for management by simple closures.

One hundred seven patients with perforated gastric ulcers were treated by either simple closures (omental patches, 81 patients; primary suture without patches, 13 patients; or ulcer excisions with closures, two patients) or primary gastric resections (11 patients). The latter were performed when ulcers were too large to be treated by simple closures. The mortality rate after omental patches or ulcer excisions with closures was 12%, while that following primary gastric resections was 45%. Patients who underwent closures with suturing only had a mortality rate of 62%, which was significantly higher than the mortality rate following patch closures. Gastric outlet obstructions developed following 15% of simple closures of prepyloric ulcers. Closures of perforated gastric ulcers with omental patches or ulcer excisions can be undertaken with low mortality and morbidity rates. Primary gastric resections are reserved for patients with ulcers that are large or located in the prepyloric area.

Adult↗
PubMed1988

Hepatic abscess: sensitivity of imaging tests and clinical findings.

The imaging studies of 63 patients with hepatic abscess were evaluated to determine the sensitivity of specific imaging tests and define causes of false-negative test results. Computed tomography (CT) detected 57 of 59 (97%) separate episodes of hepatic abscess. The two false-negative CT examinations were in patients with a diffuse low-density pattern throughout the liver. The radionuclide (RN) examination detected 16 of 20 (80%) cases, missing abscesses less than 2 cm in diameter. Ultrasound detected 33 of 42 (79%) cases, missing abscesses in the dome of the liver, small abscesses, and 2 large early abscesses. For all three imaging modalities, a specific diagnosis of abscess was possible only in those patients in whom CT scans demonstrated abscess gas (15%). The results of the imaging studies were correlated with the patients' clinical condition and laboratory findings. Thirty-one percent of patients were afebrile while 23% had normal white blood cell counts. Thirteen percent had totally normal liver function tests. We conclude that the clinical absence of fever, leukocytosis, or elevated liver function tests does not permit exclusion of the diagnosis of hepatic abscess. A CT scan is highly specific in excluding the diagnosis of hepatic abscess in the absence of diffuse liver disease. In this retrospective study CT was the most sensitive imaging modality available for the detection of hepatic abscess.

Adolescent↗
PubMed1988

Progressive CT appearance of hepatic metastases from colorectal carcinoma.

An 8-year retrospective review of 106 serial computed tomographic (CT) examinations performed on 32 patients with colorectal carcinoma metastatic to the liver was done to determine if the CT appearance of such metastases changed with a favorable response to chemotherapy or with progression of disease. Of these 32 patients, 15 underwent placement of an infusion pump for delivery of chemotherapy directly into the hepatic artery, 3 underwent partial hepatectomy, 1 underwent both procedures, and 13 underwent neither. Regression of hepatic metastases (7 patients), only seen following infusion pump placement, was associated with a decrease in size and an increase in margination of lesions. In two of these patients regression of metastases was seen in one area of the liver with subsequent progression or development of metastases in another region, presumably due to preferential delivery of chemotherapeutic agent. Progression of disease (23 patients) was associated with an increase in both size and number of lesions that became progressively less well marginated. Development of poorly marginated or infiltrative characteristics at the periphery of the lesion was associated with a poor prognosis. Thus, the CT characteristics of hepatic metastases from colorectal carcinoma differ with a favorable response to chemotherapy and with progression of disease.

Adenocarcinoma↗
PubMed1988

Biliary complications after liver transplantation in patients with preexisting sclerosing cholangitis.

To determine if biliary complications after liver transplantation are more frequent in patients with preexisting sclerosing cholangitis and to clarify the role of interventional procedures in this setting, the authors reviewed all 40 adult cases in which liver transplantation was performed at their institution over a 3 1/2-year period. Biliary complications, particularly strictures at the choledochojejunostomy and debris in the intrahepatic and common ducts, were seen in six of ten liver transplant patients (60%) with preexisting sclerosing cholangitis; this is six times the frequency of biliary complications seen in other adult recipients (10%). Biliary complications were definitively diagnosed and managed with interventional radiologic procedures. Obstruction due to anastomotic strictures required treatment with balloon dilation in all six of the affected patients. Obstructive biliary complications occur in many liver recipients with preexisting sclerosing cholangitis. These complications require aggressive radiologic assessment and intervention but to date have not adversely affected survival.

Adult↗