Type a dissection after implantation of a stent-graft triggered by an intramural hematoma.

PURPOSE: To describe an unusual case of multiple aneurysm disease in a patient who developed stent-graft-associated type A dissection. CASE REPORT: A 72-year-old man presented with pericardial tamponade, which was treated with pericardial drainage. A small intramural hematoma of the ascending aorta was found originating from a proximal descending thoracic aortic aneurysm (TAA); he also had an infrarenal abdominal aortic aneurysm (AAA). After stabilization of the hematoma 7 weeks later, the TAA was repaired with a Relay stent-graft. Type A dissection followed after 3 days and acute rupture of the AAA 6 days later. Emergency surgical repair of both complications achieved successful outcome of an extended 3-stage procedure. CONCLUSION: This case provides insight into the mechanisms that may contribute to stent-graft-associated type A dissection. Probably the previous separation of the aortic wall layers by the intramural hematoma triggered the complication, although the aorta appeared to have stabilized.

Modulation of graft arteriosclerosis in a rat carotid transplantation model.

BACKGROUND: Venous autografts used in cardiovascular surgery tend to deteriorate over time due to arteriosclerotic complications. Cadaveric vascular allografts represent a possible alternative for this application, but donor endothelial cells (ECs) and antigen presenting cells of the graft trigger alloresponses mediated by MHC class I (MHC I) antigen, leading to graft failure. Vascular allograft rejection might be prevented by reducing cell surface expression of MHC I and thereby lowering the immunogenicity of the grafts. MATERIAL AND METHODS: An Intrabody approach was used to reduce MHC I expression in vascular allografts. The efficacy of an adenovirus (Ad) carrying an anti-MHC I Intrabody gene (Ad-Intrabody) was first tested in vitro using rat aortic ECs. The effect of the Ad-Intrabody was then studied in vivo by a model of rat carotid artery transplantation. Grafts were analyzed 7 and 28 days after transplantation by immunohistochemistry and real time reverse transcriptase-polymerase chain reaction. RESULTS: Ad-Intrabody gene transfer reduced MHC I surface expression of rat ECs and inhibited in vivo alloimmune responses to carotid allografts. Decreased T cell and macrophage infiltration was observed within Ad-Intrabody transduced arterial allografts at day 28. This was associated with an inhibition of intimal thickening formation. Analysis of mRNA showed diminished levels of T cell markers and Interferon-gamma expression in the Ad-Intrabody-treated group compared with control groups. CONCLUSIONS: Ex vivo adenoviral gene transfer of an Intrabody against MHC I into rat carotid arteries prior to transplantation reduced both graft arteriosclerosis and inflammation in the absence of any systemic immunosuppression.

Triage of patients with suspected coronary artery disease using multislice computed tomography.

RATIONALE AND OBJECTIVES: Several studies have shown that multislice computed tomography (MSCT) has a high sensitivity and specificity for detecting coronary artery stenoses. The aim of the present study was to investigate whether MSCT can reliably triage patients with suspected coronary artery disease (CAD) to coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), or no revascularization. MATERIALS AND METHODS: A total of 123 patients with suspected CAD who were referred for conventional coronary angiography (CATH) additionally underwent MSCT (16*0.5 mm detector collimation). Therapeutic decisions made on the basis of CATH and MSCT strictly following current guidelines for treatment of CAD were compared with decisions made by a cardiac surgeon and an interventional cardiologist. Only MSCTs with at least adequate image quality in all coronary segments were included in the analysis (94/123). RESULTS: Decisions made on the basis of MSCT and CATH according to guidelines did not differ significantly (agreement of 88%, 82 of 94, P = .319). The therapeutic decisions made by the interventional cardiologist and the cardiac surgeon based on CATH differed significantly (overall agreement of 79%, 74 of 94 cases, P < .001; cardiologist: 78% PCI and 22% CABG versus surgeon: 38% PCI and 62% CABG), whereas there was 100% agreement regarding decisions for or against invasive treatment. CONCLUSIONS: MSCT shows good agreement with CATH in triaging patients with suspected CAD to CABG, PCI, or no revascularization. The choice of revascularization procedure is significantly more strongly influenced by whether an interventional cardiologist or a cardiac surgeon makes the decision than by the diagnostic test on which the decision is based.

Decline of surface MHC I by adenoviral gene transfer of anti-MHC I intrabodies in human endothelial cells-new perspectives for the generation of universal donor cells for tissue transplantation.

BACKGROUND: The seeding of small-calibre vascular polytetrafluoroethylene (PTFE) grafts with endothelial cells provides an increase in biocompatibility of the graft surface. The harvest and ex vivo culture of autologous endothelial cells is highly delicate. Allogeneic human umbilical vein endothelial cells (HUVEC) could be a potential cell source-however, rejection might occur due to major histocompatibility complex (MHC) I mismatches. Lowering cell surface MHC I expression on endothelial cells by gene transfer of an anti-MHC I intrabody might reduce graft failure. The intrabody consists of a single-chain variable fragment (sFv) of an anti-MHC I antibody, carrying a terminal KDEL sequence to retain the molecule together with the MHC I inside the endoplasmic reticulum. METHODS: Adenoviral gene transfer was used to express the intrabody in HUVEC. The MHC I surface expression was measured 48 h after transduction by flow cytometry. Functional effects of the intrabody expression were analyzed in a calcein release cytotoxicity assay. RESULTS: A transduction efficiency of more than 95% with EGFP-adenovirus indicates a sufficient gene transfer into HUVEC. Intrabody-adenovirus-transduced HUVEC show a massive reduction in MHC I surface expression creating almost a complete 'knockout' phenotype. Stimulation with inflammatory cytokines could not overcome this effect. The cell lysis of anti-MHC I intrabody-expressing HUVEC in a cytotoxicity assay is reduced when compared with the level of the MHC mismatched control. CONCLUSIONS: Our data indicate that HUVEC with reduced levels of MHC I might be used as universal donor cells for the seeding of vascular grafts.

Left Ventricular Thrombus After Pregnancy: Choice of Surgical Access Using Dynamic Three-Dimensional Echocardiography.

Two idiopathic thrombi loosely attached to the left ventricular wall were detected by dynamic three-dimensional echocardiography. Because the thrombi were shown to be lobulated and extremely mobile, urgent surgical treatment was mandatory. Three-dimensional image reconstruction enhanced appreciation of left ventricular thrombi by enabling accurate imaging of the spatial relationship between the thrombus, the myocardial wall, and the valvular apparatus, so that the most advantageous surgical access could be chosen. (ECHOCARDIOGRAPHY, Volume 13, May 1996)