Aortic annuloplasty: towards a standardized approach of conservative aortic valve surgery.

Dystrophy represents the most common etiology of aortic insufficiency and aortic root aneurysms in Western countries. Main characteristic lesions of dystrophic aortic roots are the constant dilation of the aortic annular base and sinotubular junction diameters, preventing coaptation of otherwise pliable bicuspid or tricuspid valves. Although these lesions are amenable to conservative aortic valve surgery, mechanical valve replacement remains the surgical standard. The multiplicity of current surgical techniques for conservative aortic valve repair substantiates the need for standardization. Analysis of the literature emphasizes two basic surgical objectives: the treatment of the lesions (dilation of aortic annular base and sinotubular junction) as well as the preservation of aortic root dynamics. From these findings, we suggest a standardized approach for conservative aortic valve surgery meeting both of these principles, based on the implantation of an expansible aortic ring. In the case of aortic root aneurysm, the remodeling technique is combined with a subvalvular external aortic annuloplasty. In the case of isolated aortic insufficiency, a double aortic annuloplasty (sub- and supravalvular) is performed.

Aortic annuloplasty: towards a standardized approach of conservative aortic valve surgery.

Dystrophy represents the most common etiology of aortic insufficiency and aortic root aneurysms in Western countries. Main characteristic lesions of dystrophic aortic roots are the constant dilation of the aortic annular base and sinotubular junction diameters, preventing coaptation of otherwise pliable bicuspid or tricuspid valves. Although these lesions are amenable to conservative aortic valve surgery, mechanical valve replacement remains the surgical standard. The multiplicity of current surgical techniques for conservative aortic valve repair substantiates the need for standardization. Analysis of the literature emphasizes two basic surgical objectives: the treatment of the lesions (dilation of aortic annular base and sinotubular junction) as well as the preservation of aortic root dynamics. From these findings, we suggest a standardized approach for conservative aortic valve surgery meeting both of these principles, based on the implantation of an expansible aortic ring. In the case of aortic root aneurysm, the remodeling technique is combined with a subvalvular external aortic annuloplasty. In the case of isolated aortic insufficiency, a double aortic annuloplasty (sub- and supravalvular) is performed.

Aortic prosthetic ring annuloplasty: a useful adjunct to a standardized aortic valve-sparing procedure?

OBJECTIVE: Dilation of aortic annulus, sinuses of Valsalva, and sinotubular junction (STJ) diameters are the characteristic lesions of aortic root aneurysm. The remodeling technique reduces STJ diameter and creates three neosinuses of Valsalva. Alternatively, the reimplantation technique reduces both annulus and STJ diameters to the detriment of aortic root dynamics. Although the remodeling technique is recognized as the most physiological valve-sparing procedure, aortic annulus dilation may jeopardize its results. A standardized approach that combines an external subvalvular aortic prosthetic ring annuloplasty with the remodeling technique is suggested. METHODS: Eighty-three patients underwent an elective aortic root remodeling procedure, either isolated (group 1, n=34) or combined with an external subvalvular aortic prosthetic ring annuloplasty (group 2, n=49). Preoperative aortic regurgitation was 1.59+/-1.1 (group 1) and 1.97+/-1.3 (group 2) (NS). The aortic annulus was more dilated in group 2 than in group 1 (27+/-2.77 mm vs 26.4+/-2.3 mm, p<0.01). Residual aortic regurgitation > or =grade II was the conversion criteria for aortic valve replacement. RESULTS: Operative mortality was 3.6% (n=3). Intraoperative conversion for valve replacement was 32.7% in group 1 (n=11) versus 4.2% in group 2 (n=2) (p<0.001). In group 1, preoperative annulus diameter was larger for converted than for valve-spared patients (27.6+/-1.7 mm vs 25.2+/-1.5 mm, p<0.02). In group 2, implanted aortic ring significantly reduced annulus diameter (20.6+/-1.8 mm) without significant aortic valve gradient (8.3+/-3 mmHg). Follow-up was 17.2+/-13.4 months (group 1) and 10.41+/-7.95 months (group 2). Reoperation for recurrent aortic regurgitation was 13% in group 1 (n=3) versus 4.2% in group 2 (n=2). Echocardiographic follow-up found residual aortic regurgitation < or =grade I in 17 patients in group 1 (90%) versus 43 patients in group 2 (95.5%) and of grade II in two patients in group 1 (10%) and two patients in group 2 (4.5%). CONCLUSION: The addition of external aortic prosthetic ring annuloplasty improves the remodeling technique's operative reproducibility and short-term results. Therefore, its use as a systematical adjunct to the remodeling procedure is suggested. However, further long-term evaluation comparing this valve-sparing procedure to composite graft replacement should define the best surgical strategy for aortic root aneurysm.

Remifentanil induces systemic arterial vasodilation in humans with a total artificial heart.

BACKGROUND: To assess intrinsic vascular effects of remifentanil, increased concentrations were infused in critically ill patients with a total artificial heart. METHODS: In the early postoperative period after implantation of a total artificial heart, nine ventilated patients requiring short general anesthesia were included in this study. After anesthesia was induced with 0.3 mg/kg intravenous etomidate, the artificial heart settings were modified to render cardiac output "preload-independent." While maintenance of anesthesia was ensured by a continuous infusion of etomidate, increased concentrations of remifentanil (from 0.1 to 1 microg x kg(-1) x min(-1)) were infused in steps of 5 min under hemodynamic monitoring, including left and right atrial pressures, systemic and pulmonary arterial pressures, and left and right cardiac indices. The invasive procedure was started under the highest concentration of remifentanil tolerated by the patient. Infusion of remifentanil was stopped at the end of the invasive procedure, while etomidate infusion was maintained. New hemodynamic measurements were performed at the end of the 12-min recovery period. RESULTS: Remifentanil produced a dose-dependent and significant decrease in systemic arterial pressure and vascular resistances (n = 9) from a concentration of 0.25 microg x kg(-1) x min(-1). No significant changes were observed on pulmonary vascular resistances (n = 6). Neither right (n = 9) nor left (n = 6) atrial pressures were affected by remifentanil infusion. Hemodynamic variables returned to baseline value over the 12-min recovery period. CONCLUSIONS: In humans with a total artificial heart, remifentanil induces a systemic arterial vasodilation without significant effect on the capacitance vessels.