Background: Ninety-four patients (37 male, 57 female; mean age, 51.0 years) underwent reconstruction for renal artery aneurysm (RAA) between 1980 and 2001. RAAs were present in 52 patients in the ...right kidney, in 29 patients in the left kidney, and in 13 patients in both kidneys. Eighty-three aneurysms were located in the mainstem, 49 in a branch artery, and four in an accessory artery. Additional ipsilateral renal artery stenoses (RAS) occurred in 26 patients, bilateral RAS in 18, and contralateral RAS in six. The causes of RAA were fibromuscular dysplasia (n = 48), atherosclerosis (n = 28), dissection (n = 7), aortic coarctation (n = 5), arteritis (n = 3), giant cell arteritis (n = 1), Marfan's syndrome (n = 1), and trauma (n = 1). Seventy-five patients had hypertension, 14 were asymptomatic, and five had rupture. Indications for RAA repair concerned aneurysms with 1 cm or more diameter in combination with risk factors of hypertension, ipsilateral and contralateral stenosis, and childbearing age in women. Without risk factors, aneurysm size eligible for reconstruction was limited to 2 cm or more.
Methods: Methods applied for reconstruction in 107 kidneys and 136 aneurysms included aneurysm resection with tailoring (n = 37), saphenous vein graft interposition (n = 40), tailoring and saphenous vein graft interposition (n = 7), resection and reanastomosis (n = 14), saphenous vein graft interposition and resection and reanastomosis (n = 3), polytetrafluoroethylene bypass (n = 5), and homologous vein graft interposition (n = 1). Four reconstructions had to be performed ex situ because of multiple branch involvement in three patients and rupture in one. In all patients, the concerned kidney was protected with hypothermic flush perfusion with addition of heparin and prostaglandin E
1.
Results: The overall morbidity rate was 17%, including one early graft occlusion, one partial thrombosis of the renal artery that necessitated fibrinolytic therapy, and a branch artery stenosis after tailoring managed with aortorenal bypass. The mortality in elective cases was null; one patient died of myocardial infarction 2 days after an emergency operation for ruptured RAA. The technical primary success rate was 96.8%; the secondary success rate was 98.9%. After a follow-up period from 1 to 143 months (mean, 46 months) in 83 patients (88%), 67 (81%) had patent renal arteries free of stenoses. Among six patients with RAS, four underwent successful reoperation, five had mainstem occlusions, three had segmental artery occlusions, and two underwent nephrectomy. Concerning the patients who underwent reoperation, percutaneous transluminal angioplasty was considered seriously but assessed as inappropriate because of long extension of stenosis or involvement of branch arteries. Hypertension was cured in 19 patients (25%) and improved in 17 (22%).
Conclusion: Surgical reconstruction of RAA is a safe procedure that provides good long-term results, prevents aneurysm rupture, cures or improves hypertension in about half of the cases, and can be achieved with autogenous reconstruction in 96%. (J Vasc Surg 2003;37:293-300.)
The molecular modeling, synthesis, and elucidations of the solid state and solution structures of N-methylated 3,5-linked bispyrrolin-4-ones are described. Prior investigations established that the ...3,5-linked pyrrolin-4-one based scaffold can be incorporated into mimics of beta-sheet/beta-strands and into potent, orally bioavailable inhibitors of the HIV-1 protease. To extend the utility of this scaffold beyond that of the initially designed mimics of beta-sheet/beta-strands, we have now explored the structure of N-methylated pyrrolinones. Molecular modeling indicated that N-methylated bispyrrolinones could adopt three low-energy backbone conformations (ca. 165 degrees, 289 degrees, and 320 degrees). Upon their successful synthesis, structural elucidation both in the solid state and in solution revealed the existence of two of the three predicted backbone conformers (ca. 165 degrees and 289 degrees). Two structures were particularly noteworthy and completely unexpected. Mono-N-methyl bispyrrolinone (+)-1 self assembled in the solid state to form a novel helix, while the acetylene-linked dimer of (+)-1, designed to potentiate the observed helical array, instead associated via an intermolecular hydrogen bond in parallel columns. These serendipitous observations led us to speculate that the pyrrolinone moiety may in fact represent a privileged nonpeptide scaffold, able to mimic not only the extended beta-sheet/beta-strand conformation as initially targeted, but also diverse conformations including those analogous to beta-turns and helices. These seemingly unlimited conformations greatly expand the scope of this scaffold for the development of low-molecular weight ligands for biologically important macromolecules.
To our knowledge, no large-scale studies comparing the accuracy of CT angiography (CTA) to intraarterial digital subtraction angiography (DSA) of intracranial stenosis have been reported. We ...attempted to determine the diagnostic value of intracranial CT angiography (CTA) of normal vasculature and variants as well as of stenoocclusive disease.
One-hundred and twelve patients underwent CTA and intraarterial angiography, and 2205 vascular segments were examined to ascertain presence, visibility, and degree of arterial stenoses (n = 105) as well as anatomic variants. Source, maximum intensity projection (MIP), and MIP-generated multiplanar reformatted (MPR) images were evaluated.
All 55 anatomic variants were identified correctly. Visibility of small-vessel segments was increased from 75% to 83% by using source images. MPR was helpful in differentiating distal vertebral hypoplasia from stenosis and in overcoming artifacts. All 43 occlusive segments were graded correctly (sensitivity = 100%, predictive value = 93.4%) as follows: severely stenotic (n = 23, sensitivity = 78%, predictive value = 81.8%); moderately stenotic (n = 36, sensitivity = 61%, predictive value = 84.6%); and mildly stenotic (n = 3, sensitivity = 66%, predictive value = 28%). Normal segments (n = 2100) had a sensitivity of 99.5%, and CTA evinced a specificity of 99% for detecting stenoocclusive disease. Approximately one-third of wrong assessments were related to the petrous segment of the carotid artery.
CTA with double-detector technology and advanced postprocessing algorithms, including MPR, is about as reliable as MRA in depicting the vasculature of the anterior and posterior circulation and in grading intracranial stenoocclusive lesions, with the exception of the petrous segment of the carotid artery. CTA might be superior to MRA in the evaluation of poststenotic low-flow segments.
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