Biomedical subjects

Armin Erasmi

Publications and source records attributed to Armin Erasmi.

3 recordsLinked to original sources

PubMed2005

Ross procedure and left ventricular mass regression.

BACKGROUND: Return of left ventricular mass to normal is considered to be a favorable result of aortic valve replacement. The Ross procedure provides near normal hemodynamics and thus allows studies of left ventricular (LV) reverse remodeling. LV mass regression may be influenced by surgical technique (subcoronary [SC] versus root replacement [RR]). METHODS AND RESULTS: Data from the German Ross Registry were analyzed. A total of 646 patients (mean age: 43.6+/-12.7 years, range: 16 to 71 years; SC technique n=295, RR technique n=351) underwent a Ross procedure in 7 participating centers from 1990 to 2004. The patients underwent preoperative and postoperative echocardiographic evaluations. Mean follow-up time was 3.5+/-2.5 years (range 0.12 to 13.7 years). Follow-up completeness was 97%. The LV mass index (LVMI) decreased significantly during follow-up in both groups (SC: 209+/-53 preoperatively to 154+/-48 at 1-year follow-up, [P<0.01 versus preoperative values] to 149+/-51 g/m2 at 2-year follow-up, [P=NS 1-year versus 2-year follow-up] versus RR: from 195+/-56 preoperatively to 144+/-51 at 1-year follow-up [P<0.01 versus preoperative values] to 140+/-49 g/m2 [P=NS 1-year versus 2-year follow-up]). LVMI regression remained stagnant 1 year after the Ross procedure in most patients in both groups. On the basis of multivariate analysis, predictors for incomplete LVMI regression after the autograft procedure were high preoperative LVMI, smoking, and uncontrolled diastolic hypertension. CONCLUSIONS: At mid-term echocardiographic follow-up, patients of both groups had favorable autograft hemodynamics. Risk factors for incomplete postoperative LVMI regression in our study were smoking and persistent diastolic hypertension. This emphasizes the importance of cessation of smoking and treatment of arterial hypertension, even in younger patients, after corrected aortic valve disease.

Adolescent↗

PubMed2005

In vitro hydrodynamics, cusp-bending deformation, and root distensibility for different types of aortic valve-sparing operations: remodeling, sinus prosthesis, and reimplantation.

OBJECTIVE: Preserving aortic valve cusps during operations for aortic root pathology theoretically offers several advantages over alternative prosthetic valve-bearing conduits. Functional properties of different valve-sparing techniques under defined conditions are not well studied. METHODS: Fresh porcine aortic roots were investigated in a pulsatile flow simulator, either native root or after different types of valve-sparing procedures (remodeling, sinus prosthesis, and reimplantation). Functional parameters, such as transvalvular pressure gradient, closing volume, cusp-bending deformation, and distensibility at different levels of the root were analyzed. RESULTS: The mean pressure gradient was highest in reimplantation techniques (8.4 +/- 1.8 mm Hg) compared with sinus prostheses (7.2 +/- 0.9 mm Hg, P = .01) and remodeling techniques (6.8 +/- 1.0 mm Hg, P = .002), mirror imaging the closing volume (reimplantation, 1.5 +/- 0.4 mL; sinus prostheses, 2.3 +/- 0.7 mL [P < .001]; remodeling, 3.4 +/- 1.1 mL [P < .001]). Bending deformation indices increased significantly from remodeling (0.45 +/- 0.05) and sinus prostheses (0.58 +/- 0.06) to reimplantation techniques (0.73 +/- 0.09). Dynamic changes in area of all techniques were decreased at the sinotubular junction and the commissural and sinus levels when compared with those seen in native roots but increased at the annular level for techniques with unfixed annulus (remodeling and modified sinus prosthesis). CONCLUSIONS: In vitro the various aortic valve-sparing operations differed characteristically in their ability to spare valve function, none of them completely meeting native valve behavior. The remodeling techniques exhibited valve dynamics closest to those of the native aortic root. The more the aortic valve is fixed with noncompliant prosthetic material, the more the native root dynamics are impaired.

Animals↗

PubMed2003

Prophylactic gamma radiation of unaffected vein grafts failed to prevent vein graft disease in a chronic hypercholesterolemic porcine model.

OBJECTIVE: The value of prophylactic brachytherapy on vein graft disease is unknown. METHODS AND RESULTS: Vein bypass grafts in 23 hypercholesterolemic pigs after ex vivo gamma irradiation of the vein grafts (10, 20, and 40Gy) and 16 control veins were analyzed regarding: (1) expression of platelet-derived growth factor (PDGF-AA and -BB, ELISA); (2) smooth muscle cell (SMC) proliferation/cell death (double-immunohistochemistry Mib-1/TUNEL/SMC alpha-actin); and (3) vessel wall dimensions. Planimetric data on vessel wall dimensions revealed no positive effect of gamma radiation on neointima formation and inner lumen diameter. On the contrary, vein grafts subjected to 40Gy were significantly more likely to be occluded and to have reduced inner lumen and increased neointima formation. Radiation therapy had no effect on PDGF expression and SMC proliferation/cell death. The mean inner lumen diameter decreased as PDGF-AA expression increased. CONCLUSIONS: Prophylactic gamma radiation of unaffected vein grafts failed to prevent vein graft disease in a hypercholesterolemic porcine model. High-dose radiation (40Gy) resulted in more frequent graft occlusion and vein sclerosis.

Anastomosis, Surgical↗