Dissection of an iliac artery conduit to liver allograft: treatment with an endovascular stent.

Hepatic artery thrombosis remains one of the most serious complications after orthotopic liver transplantation. Sepsis, biliary leakage and strictures, and retransplantation are often the result of this devastating complication. Because retransplantation or reoperation is sometimes not possible or advisable, other means of reestablishing hepatic artery continuity are desirable. We describe a liver transplant recipient who developed a dissection of an iliac artery conduit after retransplantation that was treated with fibrinolytic therapy followed by successful placement of an endovascular stent.

Role of bronchial artery embolization in the management of hemoptysis.

OBJECTIVE: To assess the modern morbidity of hemoptysis and the contribution of therapeutic bronchial artery embolization to its management. METHODS: Medical record review of patients admitted for the treatment of hemoptysis from January 1991 to November 1995 and of patients who had therapeutic bronchial artery embolization from June 1986 to August 1995. Hemoptysis was labeled major or minor. RESULTS: A total of 138 patients were admitted with hemoptysis, 31 with major and 107 with minor hemoptysis. No emergency pulmonary resections were required. Mean follow-up was 13.5 months. Mortality was 29.7% (41/138) but was caused by bronchial bleeding in only 4.3% (6/138). Twenty-six patients underwent therapeutic bronchial artery embolization (mean follow-up [range], 14 months [0.3-69.0 months]). The initial success rate (no further bleeding during the initial admission) was 85% (22/26). The long-term success rate (no further bleeding during follow-up) was 58% (15/26). Only 2 patients with therapeutic bronchial artery embolization died of further hemoptysis. CONCLUSIONS: Hemoptysis signals life-threatening diseases. Therapeutic bronchial artery embolization is a good treatment adjunct to control bronchial bleeding and reduces the need for high-risk emergency lung resections.

Indirect computed tomography lymphography using iodinated nanoparticles to detect cancerous lymph nodes in a cutaneous melanoma model.

RATIONALE AND OBJECTIVES: To evaluate differences in contrast uptake in normal and cancerous lymph nodes on indirect computed tomography (CT) in swine, we conducted lymphographic examinations after subcutaneous injection of a lymphotropic iodinated nanoparticle suspension. METHODS: Perilesional subcutaneous contrast injections (2 ml per lesion) of a 15% wt/vol iodinated nanoparticle suspension were made in immature Sinclair miniature swine (n = 5) with cutaneous melanomas. Average attenuation, iodine concentration, node volume, and total iodine uptake were estimated on the CT scans for each opacified lymph node 24 hr after injection. Nodes were classified as normal or cancerous microscopically, and the percentage of tumor replacement was estimated in cancerous nodes. RESULTS: Average attenuation and iodine concentration were higher in normal nodes, and total iodine uptake was higher in cancerous nodes with greater than 25% replacement (p < .05). Architectural alterations in opacified cancerous nodes included medullary filling defects, expansile cortical lesions, and disruption of corticomedullary junctions. CONCLUSION: Quantitative and qualitative differences in iodinated nanoparticle enhancement characteristics are useful in distinguishing between normal and cancerous lymph nodes on indirect CT lymphography examinations.

Palliative embolization of fibrosarcoma for control of tumor-induced hypoglycemia.

A 77-year-old woman with prior long-standing insulin-dependent diabetes presented with malignant hypoglycemia secondary to insulin-like substances excreted from a large unresectable fibrosarcoma of the left thigh. Partial embolization of the tumor supply from the deep femoral artery was performed using 150-250 microns polyvinyl alcohol foam particles. After embolization, the patient's serum glucose levels reverted to normal and she could be discharged from the hospital.

Hydrogel embolic agents. Theory and practice of adding radio-opacity.

RATIONALE AND OBJECTIVES: Spheres of hydrogel have been developed as embolic material with the ability to incorporate radio-opaque materials. To optimize particle design for radiographic or fluoroscopic visualization, we have examined the theoretical determinants of particle contrast. In addition, loaded hydrogel particles were tested in a rabbit model. METHODS: Computer simulations of particle subject contrast were examined regarding particle composition, particle size, patient thickness, and x-ray beam kilovoltage. Embolizations in the rabbit kidney were used to test the practical aspects of the materials. RESULTS: Tantalum and tungsten offer some theoretical and practical advantages over other materials. With this particular hydrogel preparation, contrast material loading was limited to 20% of the volume as loaded contrast agent. The soft particles passed through catheters as small as 3 French; they were usually injected as a suspension of saline/contrast material. Tantalum/hydrogel particles as large as 2 mm could be forced through the 140 cm/3-Fr catheter with a guide wire. CONCLUSIONS: Radio-opacity of embolic material should add an element of control in embolization procedures that is lacking with the current agents. The heavy metals, tungsten and tantalum, are suitable additives for radiopaque material for hydrogel emboli. The input relationship appears predictable with computer monitoring techniques. Initial results in a study of these radiopaque particles are very encouraging. Further studies are underway to evaluate the long-term effects in renal and hepatic circulations.

Superior mesenteric artery vasoactivity in hyperlipidemic Watanabe rabbits versus normal lipidemic New Zealand controls.

Recent in vitro studies on isolated coronary and mesenteric arteries have shown that hyperlipidemia appears to hypersensitize the vascular arterial smooth muscle to drugs such as ergonovine and that this increased contractility seems to be mediated by a serotinergic mechanism. This results in vasospasm with exposure to certain vasoactive drugs such as serotonin or norepinephrine. However, in vivo quantification of this observed phenomenon has not been done. In the present study we used Watanabe hereditary hyperlipidemic (WHHL) rabbits (cholesterol level 459 +/- 216 mg/dL) and the normal lipidemic New Zealand white (NZW) rabbit (cholesterol level 35 +/- 19) as a control in the study of hyperlipidemia and blood flow changes in response to various vasoactive drugs. Blood flow measurements were made by the video dilution technique (VDT) following catheterization of the superior mesenteric artery. The serotinergic vasoactive drug ergonovine maleate was injected into the superior mesenteric artery at low dose (0.002) mg/kg) and high dose (0.004 mg/kg). A significant decrease (p less than .05) in blood flow was observed in response to high-dose ergonovine maleate in WHHL rabbits compared to the NZW rabbits. This in vivo experiment confirms the in vitro studies showing that hyperlipidemia sensitizes mesenteric arteries in the presence of serotinergic stimuli. The vasodilators verapamil hydrochloride and calcitonin gene-related peptide (CGRP) injected into the superior mesenteric artery caused a marked increase in flow in both the WHHL and the normal lipidemic NZW rabbits. This model can be used in the assessment of superior mesenteric artery ischemia and its reversal.

Video dilution technique. An accurate measure of blood flow during routine arteriography.

The video dilution technique for measuring blood flow consists of electronically and mathematically processing video-taped selective arteriograms to measure the flow in selectively catheterized arteries and to express this flow as a fraction of the flow in any reference artery. Flows were measured by video dilution and an electromagnetic flowmeter in ten dogs; the correlations were excellent. Video dilution flows were also measured in 105 patients. The technique is accurate, simple, and adds no risk to routine selective arteriography.

Cerebral blood flow determination by video dilution technique in a patient with malignant chemodectoma.

Cerebral angiography performed on a patient with a preliminary diagnosis of jugular foramen syndrome revealed a highly vascular malignant chemodectoma supplied mainly by the left ascending pharyngeal artery. Blood flow was determined during angiography in the extracranial branches of the carotid arteries by video dilution technique. The decrease of blood flow after partial embolization of the left ascending pharyngeal artery was also quantified. The application and value of video dilution technique in blood flow determination, together with the angiographic findings are discussed.

Selective embolization for control of gastrointestinal hemorrhage.

Transcatheter embolization using Gelfoam plugs or autologous clot is an alternative or adjunct to the conventional management of gastrointestinal hemorrhage. During a 12 month period we successfully treated 10 patients who had massive gastrointestinal hemorrhage with selective embolization; 6 patients had upper gastrointestinal hemorrhage and 4 had bleeding from the colon. Most of these patients were critically ill and were poor surgical candidates. Hemorrhage was controlled by selective catheterization of the bleeding vessel, followed by injection of Gelfoam pledgets. Since the procedure was accomplished with ease and prolonged hemostasis obtained, we recommend it for gastrointestinal hemorrhage, especially in patients who are poor surgical risks or are unresponsive to vasopressin infusion, or both. Operative intervention for the primary disease could subsequently be performed electively, if necessary, days or weeks after transcatheter embolization.

Arteriography before needle puncture or renal hilar lesions.

We report on 2 patients with cystic-appearing lesions in the renal hilus that were detected on urography. In 1 case an ultrasound study confirmed a cystic mass but an arteriogram revealed a renal artery aneurysm. The arteriogram before the contemplated puncture of the renal hilar mass prevented an inadvertent puncture. The information about the arterial anatomy helped preoperative planning, which resulted in successful repair of the aneurysm by microdissection and autotransplantation.