Noninvasive evaluation of suspected thoracic aortic disease by contrast-enhanced computed tomography.

Traditionally, suspected thoracic aortic disease has been evaluated by aortography, which has associated risks because it is invasive. With the introduction of computed tomography (CT), a noninvasive alternative has become available. In the present retrospective study, the potential clinical value of CT in providing correct diagnoses and pertinent information required for current therapies is evaluated. For this purpose, results of CT in 200 patients examined for suspected thoracic aortic disease were compared with "hard" (surgical and autopsy findings) or "soft" (follow-up clinical information) evidence of the true diagnoses. Aortographic results, available in 51 patients (26%), were also compared with available clinical evidence. Excluding inadequate examinations, the diagnostic accuracy of the independently and blindly interpreted results of CT and aortography were similar (86% and 87%, respectively) in patients with true diagnoses confirmed by hard evidence. When patients evaluated for aortic damage from acute blunt chest trauma were also excluded, the accuracy was 90% for CT and 86% for aortography. Specifically, CT was 83% and 67% accurate in proved (i.e., confirmed by hard evidence) type A and type B dissections, respectively (75% for both type A and B by aortography). In the 183 patients suspected of having thoracic aortic disease not attributable to acute blunt chest trauma and with follow-up information, 91% would have been managed appropriately based on their CT evaluation alone. In the subset of patients who underwent aortographic evaluation as well, 91% would have been managed appropriately based on aortography alone. The accuracy for combined CT and aortography was 94%.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous drainage techniques. Alternatives to surgical therapy.

Percutaneous drainage techniques are widely used to relieve biliary and urinary obstructions as well as to evacuate abdominal abscesses. These drainage techniques are less expensive, safer, and in many cases more effective than comparable surgical procedures. Proper follow-up care of catheters is essential, however, to achieve maximum effectiveness.

Radiologic intervention in oriental cholangiohepatitis.

Interventional radiologic techniques can make a useful contribution to the management of patients with recurrent symptoms following surgical palliation of oriental cholangiohepatitis. Percutaneous removal of multiple, soft, pigmented biliary stones that form in this disease can be achieved by a combination of basket retrieval and crushing, as well as suction and irrigation techniques. Ducts that are obstructed by strictures can be drained by percutaneous catheters. Complete or partial symptomatic relief was obtained in six of eight patients, obviating additional surgical intervention.

Esophageal rupture: complication of balloon dilatation.

Recent studies have emphasized the safety of fluoroscopically guided balloon dilatation for treatment of severe esophageal strictures. A case of esophageal rupture that followed dilatation of a distal esophageal stricture with a 20-mm balloon catheter is reported.

Abdominal abscess with low-output fistula: successful percutaneous drainage.

Abdominal abscesses in 72 patients were drained percutaneously. Sinograms were obtained at the time of drainage and repeated three to six days later. In 32 patients, a low-output fistulous communication to the alimentary canal, biliary tract, or pancreatic duct was demonstrated. Percutaneously placed drainage catheters provided successful treatment in 27 of these 32 patients. We conclude that low-output fistulous communications to abdominal cavities occur frequently, but can be managed successfully with percutaneous techniques in the majority of patients.

Biliary endoprostheses. Insertion using a combined peroral-transhepatic method.

The transhepatic placement of adequately sized endoprostheses for the palliation of malignant biliary obstruction is painful and requires large hepatic parenchymal tracks. Endoscopically placed biliary stents are smaller, but may not be adequate for long-term patency. The authors have used a combined peroral-transhepatic approach successfully to pull large endoprostheses through the alimentary track and into the biliary tree.

Bile flow through drainage catheters: an in vitro study.

An in vitro model was developed to measure bile flow at varied pressures through several commonly used transhepatic drainage catheters. As expected, larger catheters conduct more bile flow at a given pressure. All catheters studied conduct adequate amounts of bile at normal physiologic pressure gradients. The clinical observation that large catheters (10-12 French) are necessary for adequate antegrade drainage in some patients must be explained by an abnormal bile viscosity, increased duodenal pressures, or reduced biliary secretory pressure.

Percutaneous removal of renal staghorn calculi.

Using a percutaneous approach, 18 of 20 staghorn calculi were completely removed from the upper urinary tract. The initial nephrostomy was performed in the radiology department with local anesthesia. Tract dilatation and stone removal ensued on the next day in the operating room under general anesthesia. Minor complications, including postoperative temperature spikes and pyelonephritis, occurred in seven patients. Two major complications, urosepsis and hemorrhage requiring transfusion, were encountered.

Peripheral vascular disease: correlation of MR imaging and angiography.

The capability of magnetic resonance (MR) imaging for detecting aortic, iliac, and femoral stenoses and occlusions was evaluated. Multisection spin-echo studies at 0.35 tesla were obtained of the infrarenal aorta to the femoral bifurcation in 24 patients, all of whom had undergone intraarterial angiography within 14 days of imaging. Transaxial MR images were compared with the angiograms. Arterial stenoses and occlusions in these vessels detected by MR imaging correlated with angiographic findings in 91% of the instances. Protrusional atherosclerotic plaques and occlusions and stenoses in the aortoiliac region were demonstrated accurately on MR images; complications of previous vascular surgery, such as aneurysms at sites of previous anastomoses or endarterectomy, were also identified. Due to the limited spatial resolution, MR images failed to demonstrate some femoral stenoses. MR imaging may be used for evaluation of aortoiliac vascular disease and for follow-up study after surgical revascularization. However, the limited spatial resolution, noncomposite display of the aortoiliofemoral circulation, and lack of evaluation of peripheral runoff provided by current MR imaging techniques militate against its replacing angiography prior to vascular intervention.

Extrahepatic extraction of salicylamide in dogs.

Extrahepatic conjugation may be an important mechanism for the metabolism of many phenolic compounds. We have observed dose-dependent sulfoconjugation of salicylamide (SAM) in the lung, kidney and forelimb of dogs during steady-state infusions. The lungs alone accounted for more than one-half the total elimination at the lowest infusion rate (0.3 microgram/min/kg). The limbs appeared to play an important secondary role in SAM elimination whereas the kidneys made only a minor contribution to total elimination. At the highest infusion rate (500 micrograms/min/kg), extrahepatic extraction approached zero and elimination by the three extrahepatic sites fell to less than 31% of total elimination. Dose-dependent elimination at the three extrahepatic sites was responsible for most of the dose dependence observed in these studies. Extrahepatic extraction was insensitive to plasma inorganic sulfate. Clearance significantly, but only slightly, increased on coinfusing sodium sulfate at a rate that increased plasma inorganic sulfate from one-sixth (after depletion by SAM infusion) to two times normal.

Occlusion of a hepatic artery to portal vein fistula with bucrylate.

A 49-year-old woman with cirrhosis and portal hypertension was evaluated for a portal-systemic shunt procedure following recurrent variceal hemorrhage. The preoperative visceral angiogram demonstrated a hepatic arterial to portal venous fistula, presumably a complication of a previous liver biopsy. The fistula was successfully closed using isobutyl-2-cyanoacrylate (Bucrylate) delivered through a flow-directed, calibrated-leak balloon microcatheter.