Juan F. Lois

Does preoperative percutaneous biliary drainage reduce operative risk or increase hospital cost

Despite recent advances in perioperative support care, surgery for obstructive jaundice is still associated with significant morbidity and mortality. For this reason, preoperative percutaneous transhepatic drainage (PTD) has been recommended for these patients. This method of management, however, has only been supported by retrospective and nonrandomized studies. Therefore, a prospective, randomized study was performed to determine the effect of preoperative PTD on operative mortality, morbidity, hospital stay, and hospital cost. Thirty-day mortality was 8.1% among 37 patients undergoing preoperative PTD, compared to 5.3% for 38 patients who went to surgery without preoperative drainage. Overall morbidity was also slightly, but not significantly, higher in patients who underwent preoperative PTD (57% versus 53%). However, total hospital stay was significantly longer (p < 0.005) in the PTD group (31.4 days versus 23.1 days). The cost of this excess hospitalization and the PTD procedure at our university medical center was over

Aortic mural thrombus: An occult source of arterial thromboembolism

8000 per patient. The authors conclude that preoperative PTD does not reduce operative risk but does increase hospital cost and, therefore, should not be performed routinely.

Failure of duplex sonography to diagnose hepatic artery thrombosis in a high-risk group of pediatric liver transplant recipients

During a 28-year period from 1955 to 1983, two cases of massive repetitive arterial thromboembolism from nonaneurysmal aortic mural thrombus were diagnosed antemortem and successfully corrected at the University of California, Los Angeles Medical Center. Within the same time period, 48 cases of nonaneurysmal aortic mural thrombus were identified in 10,671 consecutive autopsies (0.45% incidence). Eight of these patients had evidence of distal embolization (17%), and three had major thromboembolic occlusions, which were considered the proximate cause of death (6%). The latter three patients represented 9% of autopsy-confirmed deaths from peripheral arterial thromboembolism. The diagnosis was established in a 49-year-old man and a 51-year-old woman after a long course marked by recurrent arterial embolization. Despite multiple evaluations, which included angiography, the diagnosis remained elusive until clinical suspicion resulted in complete biplane aortographic survey. Although the morphologic characteristics of this lesion are quite striking, subtle angiographic changes and lack of familiarity with the clinical presentation contribute to the difficulty and infrequency of diagnosis. This unique lesion comprises an important segment of the so-called cryptogenic sources of arterial embolization and can be corrected by a definitive surgical procedure.

Magnetic resonance imaging of the thoracic aorta

Excellent correlation between angiographic findings and duplex sonography has been previously reported in the diagnosis of hepatic artery thrombosis (HAT), the most common technical complication of pediatric orthotopic liver transplantation (OLT). We now report a significant incidence of false-negative sonograms, ie, hepatic artery reported as patent but thrombosed on subsequent angiography. HAT was diagnosed in 10 of 57 pediatric OLT recipients evaluated prospectively by duplex sonography. In 5 patients HAT was diagnosed only by angiography even though arterial wave forms were observed on duplex sonography. Selective angiography demonstrated extensive collateral vessel formation arising from the superior mesenteric artery, the celiac axis, or both. The 5 patients shared very similar clinical courses marked by relapsing bacteremias with multiple enteric organisms, associated with focal infarctions of the liver. Four of the grafts had difficult arterial reconstructions and 3 of 5 had segmental bile duct dilation. We conclude that duplex sonography has proven to be a valuable screening tool in evaluating hepatic artery patency but must be correlated with angiography studies in a high-risk group of pediatric transplant patients characterized clinically by relapsing bacteremia and radiographically by false-negative duplex examinations.

Thrombosis complicating balloon angioplasty of left pulmonary artery stenosis after Fontan's procedure: Successful treatment with intravenous streptokinase

Forty-one patients with a variety of suspected aortic lesions underwent magnetic resonance imaging (MRI) of the thoracic aorta. Patients were separated into 2 groups: Group A included 19 patients who underwent MRI after arteriography for comparison purposes and were evaluated retrospectively. Surgical confirmation was obtained in 9 of these patients. Group B included 22 patients who were studied prospectively because of abnormal chest x-ray, ultrasound or computerized tomographic findings and did not undergo arteriography before MRI. Two patients from this group had surgery. In group A, MRI correlated with the surgical or angiographic findings in 18 of 19 patients (95%). In group B, MRI was considered of diagnostic quality in all patients and no other invasive or noninvasive imaging modalities were needed for diagnosis and treatment. Thus, MRI will replace arteriography in a large proportion of patients with suspected thoracic aortic lesions.

Angiography in soft tissue sarcomas

Abstract Fontans procedure is an acceptable alternative for the palliation of tricuspid atresia, when there is no obstruction to flow within the pulmonary artery (PA) tree. We describe balloon angioplasty of a stenotic left PA in a patient with Fontans repair of tricuspid atresia. The procedure was complicated by left PA thrombosis, successfully treated with streptokinase.

Radiology and pathology of malignant fibrous histiocytomas of the soft tissues: A report of ten cases

Angiography was performed in 41 patients with histologically proven soft tissue sarcomas that included tumors derived from a variety of cell types and locations. The leiomyosarcomas and sarcomas of uncertain or mixed origin showed extensive neovascularity. Liposarcomas, synovial cell sarcomas, and fibrous histiocytic sarcomas were moderately vascularized. Sarcomas originating from vascular, fibrous, neural, and osseous tissues had variable degrees of vascularity. In nearly all of the cases studied, angiography revealed tumor size, extent, source, and degree of vascularity and helped to determine the degree of malignancy. While angiography does not provide a histologic diagnosis, it plays an important role in patient management when a conservative therapy plan that uses several modalities is followed.

Blood Flow Determinations Utilizing Digital Densitometry

Malignant fibrous histiocytomas (MFH) are believed to originate from histiocytes and are composed of malignant cells with spindle or round shapes. We evaluated ten MFH of the soft tissues by plain roentgenograms, computed tomography (CT), and angiography and subdivided them into four grades of anaplasia and five predominant histologic variants. The variants of MFH demonstrated different vascular patterns. The extension of the lesions could be determined by CT and angiography. CT is the method of choice in the assessment of size and extent of MFH of the soft tissues. When intra-arterial chemotherapy is indicated the angiograms obtained at each catheter placement may substitute CT in follow-up studies obviating additional diagnostic procedures.

Diagnostic effects of edge sharpening filtration and magnification on digitally subtracted renal images.

A method of obtaining relative and absolute blood flow measurements from digital densitometry was evaluated with a simulated vessel phantom and a hydrodynamic model. A digital vascular imaging system capable of acquisition in 512(2) and 1024(2) mode was used. Relative and absolute blood flow were measured using parameters derived from the densitometric curve. Since application of densitometric data to absolute flow measurements requires the vessel diameter, an algorithm for vessel size determination was created. Gray scale changes were demonstrated to be linearly related to contrast concentration. The variance of vessel size determination was significantly different in all combinations of 1024(2) and 512(2) imaging with 15 cm or 35 cm field size. The error in vessel size determination was significantly less using the larger 1024(2) matrix and the smaller 15 cm image intensifier field size, as shown by the smaller variance. In relative flow determinations, there was good correlation between the flow and four parameters of the densitometric curve with no significant differences between 512(2) and 1024(2) imaging. Absolute flow determinations had slightly lower correlation to actual flow but were not significantly different from relative flow determinations. Relative and absolute blood flow determinations can be performed adequately with either 512(2) or 1024(2) imaging. The increased accuracy in vessel size determination with 1024(2) imaging makes this high resolution system potentially preferable to determine absolute blood flow.

Cardiac tumors and thrombus: evaluation with MR imaging

The improved appearance of digital radiographs filtered to improve local contrast and sharpen edges has not increased acceptance of these images by radiologists. Furthermore, many radiologists assert that correct diagnosis is not improved with these filtered images. This study was designed to test this assertion for digital subtraction angiograms (DSA) of renal images. Four experiments are described. First, phantom studies identified filters and their parameters thought likely to be acceptable and useful in diagnosing renal images formed by DSA. Second, these filters and parameters were then tested on medical images to assess their acceptance by radiologists. Third, display modes of windowing, positive/negative presentation, and magnification were varied for filtered and unfiltered images to assess preferences of radiologists. Fourth, filtered and unfiltered magnified images were used to test improved diagnosis. In the final experiment, 148 images from 33 renal studies (15 normal, 18 abnormal) were magnified, gray level windowed, and filtered. Diagnosis was not improved by the two edge sharpening filters tested.