Search PubMed⌕ Search

Biomedical subjects

A Chavan

Publications and source records attributed to A Chavan.

44 records · Page 3Linked to original sources
PubMed1993

Renal arterial stenoses: spiral CT angiography.

PURPOSE: To evaluate the role of spiral computed tomography (CT) in diagnosis of renal arterial stenoses. MATERIALS AND METHODS: In 22 patients with suspected renovascular hypertension, spiral CT angiography of the renal arteries was compared with arterial digital subtraction angiography (DSA). For each patient, the peak transit time t (from intravenous injection to maximum enhancement of the abdominal aorta) was determined with a bolus injection of 15 mL of contrast medium. Spiral scanning started at the level of the superior mesenteric artery with a delay of t + 5 seconds after the start of injection of 100-150 mL of contrast medium. RESULTS: Spiral CT angiography demonstrated multiple renal arteries in five patients. A renal artery stenosis or occlusion was found in 15 of 22 patients (22 of 54 arteries). All findings were confirmed with arterial DSA. Vessel contrast on spiral CT scans was good to excellent in 19 of 22 patients. For diagnosis, axial-section and multiplanar reformatted images were superior to three-dimensional surface reconstructions and maximum-intensity projections. CONCLUSION: Spiral CT angiography is a promising screening method for renal artery stenosis.

Adult↗
PubMed1993

Transcatheter coil occlusion of an intrahepatic arterioportal fistula in a transplanted liver.

The incidence of arterioportal fistulas (APFs) following percutaneous transhepatic procedures is quoted to be between 5 and 20%; the majority of them remain clinically asymptomatic and do not require any treatment. However, an APF large enough to cause a reversal of blood flow in the portal vein is rather uncommon especially in a transplanted liver where it may have potentially hazardous consequences. We report on a 21-year-old female patient who received a liver transplantation on account of a Budd-Chiari syndrome. Following a liver biopsy, a large APF developed in the right lobe of the graft. Despite the known risks associated with catheterization of graft vessels, a successful coil occlusion of the fistula could be carried out thus rendering surgery unnecessary.

Adult↗
PubMed1993

The Filcard temporary, removable vena cava filter: use in local thrombolytic therapy.

Femoral and iliac vein thrombosis with impending pulmonary embolism is a potentially life-threatening condition. The decision whether or not to implant a permanent caval filter always requires critical consideration of a number of factors. Improper positioning of the filter with resultant filtering inefficiency, thrombosis of the filter and of the cava, propagation of the thrombus through the filter, perforation by the filter of the vena cava with penetration of the aorta, the duodenum, the psoas muscle or the vertebral body, fragmentation of the filter and migration of the filter are well-documented complications of the currently available permanent filters. The danger of fatal pulmonary embolism has to be weighed against that of one or a combination of any of the above-mentioned possible complications associated with permanent caval filters which may affect the quality of later life. We present our initial observations with a temporary, removable inferior vena cava (IVC) filter in a young female patient with a floating thrombus in the left femoral and iliac vein who underwent successful local thrombolytic therapy.

Adolescent↗
PubMed1993

Current status of the imaging modalities in the pre- and postoperative diagnostic workup of liver transplant patients.

Before transplantation, imaging procedures are mainly used to exclude factors which may serve as contraindications, render surgery difficult, or necessitate a modification of the operative technique. In addition, assessment of liver volume is necessary before segmental liver transplantation. Sonography or other cross-sectional imaging modalities are sufficient for these purposes. After transplantation, imaging is principally required in cases with suspected complications. Sonography, including Duplex and Doppler sonography, is an excellent first investigative modality for this purpose in addition to assessment of the clinical and biochemical parameters. Sonography can diagnose not only vascular complications but also biliary and infective complications; the former may also be a concealed cause of the latter. In unclear infections sonography often has to be supplemented by other modalities like CT. In equivocal cases a puncture is indicated. Invasive procedures are necessary in only selected cases, in particular when an intervention is under consideration. At present MR plays a limited role in the diagnostic workup as it rarely offers additional information except in very few cases. The early diagnosis of rejection cannot be reliably made by any of the imaging modalities and is essentially dependent on the biopsy.

Diagnostic Imaging↗
PubMed1993

The kissing balloons technique. Simultaneous dilatation of stenoses of branch arteries at the bifurcation of the renal artery.

Whereas dilatation of a single stenosis of the main renal artery is a routine intervention, a narrowing of the renal artery at its bifurcation extending into the branch arteries poses a more complex problem. The procedural risks of renal artery dilatation are compounded by the danger of occlusion of one of the branch arteries during maneuvers to dilate the other. Long-term results of surgical vascular reconstruction at a renal artery bifurcation are not satisfactory. Untreated, these stenoses lead to intractable hypertension and impairment or loss of renal function. We present a patient with hypertension and impaired function of the right kidney on account of a renal arterial bifurcation stenosis. Using a bilateral transfemoral arterial approach 2 balloon catheters were simultaneously placed into the origins of the renal artery branches and both arteries were successfully dilated by the kissing balloons technique. This method provides an elegant alternative to difficult surgery to save an endangered kidney.

Angioplasty, Balloon↗
PubMedDate not supplied

Role of liver transplantation in the treatment of unresectable liver cancer.

Resection remains the treatment of choice in liver cancer. In order to avoid liver transplantation in conventionally unresectable tumors ex-situ ("bench" procedure), in-situ and ante-situm resection technique should be preferred whenever feasible. Despite the deficiency of donor organs, a single center experience with 198 patients reveals that liver transplantation continues its role as a therapeutic option for selected patients. At present "favorable" indications for transplantation are International Union against Cancer (UICC) - stage II hepatocellular carcinoma as well as the subtype fibrolamellar carcinoma, uncommon tumors such as epitheloid hemangioendothelioma, hepatoblastoma, and liver metastases from neuroendocrine tumors. Due to unsatisfying results, intrahepatic bile duct-, stage III and IV hepatocellular carcinoma, hemangiosarcoma, and liver metastases from nonendocrine primaries should be excluded from liver transplantation alone. For these advanced tumors, especially in cases of extrahepatic involvement, a combination of liver transplantation and multivisceral resection has been proven feasible. However, a significant improvement in patient survival may only be expected only by currently investigated multimodality treatment protocols which will require further randomized studies.

Bile Duct Neoplasms↗
PubMedDate not supplied

Modification of adenylate cyclase by photoaffinity analogs of forskolin.

Photoaffinity labeling analogs of the adenylate cyclase activator forskolin (PF) have been synthesized, purified and tested for their effect on preparations of membrane-bound, Lubrol solubilized and forskolin affinity-purified adenylate cyclase (AC). All analogs of forskolin significantly activated AC. However, in the presence of 0.1 to 0.3 microM forskolin, the less active forskolin photoaffinity probes at 100 microM caused inhibition. This inhibition was dose-dependent for PF, suggesting that PF may complete with F for the same binding site(s). After cross-linking [125I]PF-M (see Figure 1 for structure) to either membrane or Lubrol-solubilized AC preparations by photolysis, a radiolabeled 100-110 kDa protein band was observed after autoradiography following SDS-PAGE. F at 100 microM blocked the photoradiolabeling of this protein. Radioiodination of forskolin-affinity purified AC showed several protein bands on autoradiogram, however, only one band (Mr = 100-110 kDa) was specifically labeled by [125I]PF-M following photolysis. The photoaffinity-labeled protein of 100-110 kDa of AC preparation of rat adipocyte may be the catalytic unit of adenylate cyclase of rat adipocyte itself as supported by the facts that [a] no other AC-regulatory proteins are known to be of this size, [b] the catalytic unit of bovine brain enzyme is in the same range and [c] this PF specifically stimulates AC activity when assayed alone, and weekly inhibits forskolin-activation of cyclase. These studies indicate that radiolabeled PF probes may be useful for photolabeling and detecting the catalytic unit of adenylate cyclase.

Adenylyl Cyclases↗