Murray J. Mazer

Incidence of shunt occlusion or stenosis following transjugular intrahepatic portosystemic shunt placement

BACKGROUND/AIMS Transjugular intrahepatic portosystemic shunt (TIPS) placement has been used for the treatment of recurrent variceal hemorrhage. The 1-year incidence of shunt stenosis or occlusion after TIPS placement was prospectively assessed, and the accuracy of Doppler ultrasonography to predict TIPS stenosis was evaluated. METHODS Twenty-two patients with recurrent variceal hemorrhage were selected for TIPS placement between April 1991 and May 1992. Preoperative and postoperative evaluation included clinical assessment, upper gastrointestinal endoscopy, portal angiography with pressure measurements, and Doppler ultrasonography. Follow-up was performed at 3 and 12 months post-TIPS and when patients developed recurrent bleeding. RESULTS Twenty-one of 22 patients (Child-Pugh class A-1, B-11, C-9) had successful TIPS placement. Seventeen of 21 patients have completed follow-up for at least 12 months. Of these 17 patients, 2 of 17 (12%) developed TIPS occlusion, 7 of 17 (41%) developed shunt stenosis, and 8 of 17 (47%) showed no stenosis on follow-up angiography. Doppler ultrasonographic assessment of the TIPS predicted shunt stenosis or occlusion with 100% sensitivity, 98% specificity, and 90% positive predictive value. CONCLUSIONS Shunt occlusion or stenosis develops frequently within 12 months after TIPS placement, and Doppler ultrasonography is accurate in the noninvasive assessment of shunt stenosis. TIPS placement without careful follow-up and shunt revision cannot be considered a long-term treatment of variceal hemorrhage.

Transcatheter arterial chemoembolization as primary treatment for hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma (HCC) in Western populations has historically been associated with poor survival. METHODS In this study, we conducted a 7-year retrospective analysis of patients with HCC undergoing transcatheter arterial chemoembolization (TACE) at our institution and examined demographics, outcomes, and complications. RESULTS During the period of study, 39 patients (25 male [64%], mean age 58 [range 17 to 86]) underwent a total of 78 chemoembolization treatments. During the same time period, an additional 31 patients received supportive care only. The majority of patients had late stage disease (American Joint Committee on Cancer stage III, IVa, or IVb) with no statistical difference noted between the two groups (P = 0.2). However, patients receiving supportive care only had significantly worse hepatic dysfunction by Childs classification (P = 0.005). Twenty-nine patients (74%) had documented cirrhosis, with hepatitis C being the most common cause in 11 of 29 (38%). In patients undergoing TACE, overall actuarial survival was 35%, 20%, and 11% at 1, 2, and 3 years with a median survival of 9.2 months, significantly improved over the group receiving supportive care only (P < 0.0001). Median survival for the group receiving supportive care was less than 3 months. Neither age nor stage had a significant impact on survival. The most common complications of TACE included transient nausea, abdominal pain, vomiting, and fever. CONCLUSIONS TACE is a safe and effective therapeutic option for selected patients with HCC not amenable to surgical intervention.

The use of inferior vena cava filters in pediatric patients for pulmonary embolus prophylaxis

PurposeTo report our experience with inferior vena cava (IVC) filters in pediatric patients.MethodsOver a 19-month period, eight low-profile percutaneously introducible IVC filters were placed in four male and four female patients aged 6–16 years (mean 11 years). Indications were contraindication to heparin in six patients, anticoagulation failure in one, and idiopathic infrarenal IVC thrombosis in one. Six of the eight devices placed were titanium Greenfield filters. One LGM and one Birds Nest filter were also placed. Two of the filters were introduced via the right internal jugular vein by cutdown, and the remainder were placed percutaneously via the right internal jugular vein or the right common femoral vein. Patients received follow-up abdominal radiographs from 2 to 13 months after IVC filter placement.ResultsAll filters were inserted successfully without complication. Three of the patients died during the follow-up period: two due to underlying brain tumors at 2 and 12 months and a third at 6 weeks due to progressive idiopathic renal vein and IVC thrombosis. The remaining five patients were all alive and well at follow-up without evidence of IVC thrombosis, pulmonary emboli, or filter migration.ConclusionIVC filter placement using available devices for percutaneous delivery is technically feasible, safe, and effective in children.

A System for Image Registration in Digital Subtraction Angiography

In the diagnosis of coronary atherosclerosis radio-opaque dye is injected into the interior of the coronary arteries to make them visible in X-ray images. Because of the confusing presence of overlying or underlying soft tissue and bone and because of the small size of the coronary arteries, large dye concentrations are required to render the arteries sufficiently visible for diagnosis. Because of its increased contrast sensitivity, digital subtraction angiography (DSA) has the potential for providing diagnostic images of the coronary arteries with significantly reduced dye concentrations (Levin, 1984; Tobis et al., 1983; Riederer and Kruger, 1983). In DSA a series of images is acquired during the time period which begins before the injection of dye and continues until the arteries are opacified. These images are then combined into a final processed image in which the change in opacity of the arteries leads to enhanced arterial contrast. A particularly useful and commonly applied DSA technique, “temporal subtraction”, involves the subtraction of a “mask” image, acquired before opacification, from a “contrast” image, acquired after opacification. Ideally, temporal subtraction produces an image in which nothing appears except those arteries in which the amount of dye present has changed, but its usefulness in practice is limited by the image degradation caused by patient motion during image acquisition. The rigid motion of bones and the elastic motion of soft tissue in the field of view cause changes in X-ray opacity which are unrelated to the influx of contrast material. When the two images are subtracted these changes appear as ghost-like artifacts which obscure the arteries to be examined.

Blunt thoracic aortic injury in children

Thoracic aortic injury (TAI) in children secondary to blunt chest trauma is rare and less well documented than TAI in adults. To further establishe the incidence and radiographic manifestations of this severe injury, we reviewed our experimence with TAI in children over an 8-year period.We performed a computer search from the Trauma Registry at our level I trauma center for all cases of TAI among patients 16 years of age or younger who were admitted after sustaining blunt chest trauma between August 1984 and September 1992. We reviewed our records of all thoracic aortograms performed on children for blunt trauma during this same time period. Indication for angiography was determined by review of chest radiographs and medical records of all patients who underwent thoracic aortography. We reviewed medical records and all available chest radiographs, computed tomography (CT) examinations, and thoracic aortograms of children diagnosed with TAI.Of 308 children admitted with blunt chest trauma, 26 (8.4%) underwent angiography to exclude aortic or great vessel injury. Of these 26 patients, three (11.5%) were diagnosed with TAI, and one patient demonstrated a traumatic pseudoaneurysm of the proximal left subclavian artery. The incidence of TAI among children who sustained blunt chest trauma was 1.0% in our series. All three patients with TAI in our series were male, ages 10–12 (mean: 11 years). Chest radiographs on two of the patients with TAI revealed mediastinal widening, ill-defined aortic outline, shift of the trachea and nasogastric tube, and depression of the left main stem bronchus. The chest radiograph in one patient with TAI was technically inadequate. CT demonstrated abnormalities in two patients. Angiographic findings were similar to those seen in adults.TAI in children is rare, occurring in 1% of children sustaining blunt chest trauma in our series. Our findings support previous reports that the plain film, CT, and angiographic findings with this injury resemble those found in adults.

HYDROSTATIC PULMONARY EDEMA IN SHEEP : EFFECTS OF BRONCHIAL ARTERY EMBOLIZATION ON THE PLAIN CHEST RADIOGRAPH

RATIONALE AND OBJECTIVES The bronchial circulation may influence pulmonary edema. This study evaluates possible effects of bronchoesophageal artery embolization on the plain film manifestations of hydrostatic pulmonary edema in sheep. METHODS Anteroposterior and lateral chest radiographs were obtained during the induction of pulmonary edema both before and after embolization of the bronchoesophageal artery in six adult sheep. Interstitial lines and perivascular, segmental bronchial, proximal bronchial, carinal, tracheal, and parenchymal edema were evaluated. RESULTS Only parenchymal edema was graded consistently. Though edema increased with left atrial pressure before embolization (P < .001), there was no similar change afterward. The embolized animals tended to be more edematous by the first film. CONCLUSION Rather than any protective effect, bronchoesophageal artery embolization may increase edema. This model may be inappropriate for further investigation of the bronchial circulation in the development of human pulmonary edema.

Practical aspects of gated magnetic resonance imaging of the pulmonary artery

A practical clinical evaluation of the role of gated magnetic resonance imaging (GMRI) for the evaluation of congenital and acquired diseases of the pulmonary artery is presented, comparing GMRI to the already established usefulness of other various noninvasive and invasive imaging modalities.