Hemodynamic performance following the Ross operation: comparison of two different techniques

BACKGROUND AND AIM OF THE STUDY: The Ross operation as aortic valve replacement has undergone technical evolution. Originally described as a subcoronary implant, the full-root replacement technique is now more common worldwide. It remains unclear which of the two techniques has the better results. Hence, the hemodynamic performances of the two implantation methods, as applied by two experienced centers, were compared as part of the German Ross Registry. METHODS: In total, 132 (Group 1, root replacement, mean age 40 +/- 14 years) and 249 (Group 2, subcoronary implant, mean age 48 +/- 14 years) consecutively operated patients were compared clinically and echocardiographically. Data were analyzed focusing on pulmonary autograft and homograft function at mid-term (2.78 +/- 1.89 versus 2.26 +/- 2.11 years). RESULTS: Echocardiography revealed autograft peak systolic gradients of 5.0 +/- 2.7 mmHg for Group 1 and 6.7 +/- 3.7 mmHg for Group 2 (p < 0.05), and an indexed effective orifice area (EOA) of 1.98 +/- 0.57 cm2/m2 and 1.64 +/- 0.43 cm2/m2 (p < 0.05), respectively. Homograft peak systolic gradients were 15.6 +/- 9.0 mmHg and 11.7 +/- 6.8 mmHg for Groups 1 and 2 (p < 0.05) respectively, and the indexed EOA with regard to the homograft was 1.08 +/- 0.49 cm2/m2 and 1.26 +/- 0.50 cm2/m2 (p < 0.05). Autograft insufficiency grade > I was present in 1.5% (2/132) of Group 1 and 2.8% (7/249) of Group 2 patients. Pulmonary insufficiency grade > I was 17.4% (23/132) for Group 1 and 4.8% (12/249) for Group 2 (p < 0.05). CONCLUSION: Although both groups enjoyed excellent hemodynamics in the mid-term, the root replacement technique had the advantage of larger annulus diameters and greater aortic EOA. Clinically relevant autograft regurgitation in both groups was gratifyingly rare, and seemed to be independent of surgical technique. Long-term durability of the more demanding subcoronary technique versus the problems of larger dimensions of the sinus of Valsalva and sinotubular junction in the free-root technique, remains to be proven. Apparent differences in pulmonary homograft hemodynamics can most likely be explained by surgical differences, younger patients in Group 1, and by homograft variation.     

Soluble L-selectin and neutrophil derived oxidative stress after pacing induced myocardial ischemia in chronic stable coronary artery disease

We studied the effect of atrial pacing induced myocardial ischemia on levels of soluble L-selectin (sL-selectin) and generation of neutrophil derived reactive oxygen species (ROS) in 10 patients with coronary artery disease (CAD) and stable angina and in six individuals without CAD. Myocardial ischemia was measured metabolically by lactate sampling from the coronary sinus (CS) and arterial blood at each pacing step. Before each pacing step, at peak pacing and shortly after cessation, plasma concentrations of sL-selectin and generation of ROS using the chemiluminescence method were measured in CS and femoral artery blood. Baseline sL-selectin levels in CS samples were significantly lower in the CAD compared to the control group (547 +/- 80 vs 836 +/- 82 ng/mL, P = 0.03). At peak pacing, nine of ten patients with CAD developed myocardial ischemia (lactate extraction ratio at rest 28% +/- 7%, at peak pacing -16% +/- 6%). In these patients, luminol-enhanced chemiluminescence (CL, 0.88 +/- 0.45 vs 1.9 +/- 0.9 cpm x 10(5), P = 0.09) and levels of sL-selectin (547 +/- 80 vs 764 +/- 86 ng/mL, P = 0.03) from naive neutrophils increased significantly in CS blood suggesting a potent in vivo activation of neutrophils. In control patients, incremental pacing caused neither myocardial ischemia nor a significant change of chemiluminescence or of sL-selectin levels. In conclusion, myocardial ischemia induced by pacing tachycardia is able to activate neutrophils in patients with chronic stable coronary artery disease leading to increased generation of ROS and shedding of L-selectin into the coronary circulation.     

Sphaeric acid, a new succinic acid derivative from a Sphaeropsis sp

The structure of sphaeric acid (1), a novel succinic acid derivative isolated from the fermentation broth of a Sphaeropsis sp., was determined by spectral data and synthetic transformation to the diol of sphaeric acid and subsequently to a pair of gamma-lactones (2 and 3).     

Die Ross-Operation bei Kindern

Objectives

To determine the durability of autografts and homografts after Ross operations in children.

Patients and methods

The data of 152 children <16 years were analyzed using the Cox proportional hazards model and hierarchical multilevel modeling.

Results

Autograft regurgitation increased with sinotubular junction diameter (p=0.028). The homograft gradient increased within the first 2 years (4.2 mmHg/year, p<0.001). Freedom from autograft and homograft reintervention at 10 years was 95.5±2.7% and 79.6±6.1%, respectively. Longer follow-up time was a risk factor for autograft reintervention (p=0.036). Use of an aortic homograft was a risk factor for conduit reintervention (p=0.013).

Conclusions

Reinterventions are necessary for autograft regurgitation and homograft stenosis. Increasing sinotubular junction diameters explain autograft regurgitation. Using pulmonary homografts delays the development of a homograft gradient.     

Right ventricular obstruction in various types of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is most probably a genetically transmitted disease with different clinical and hemodynamic features. In hypertrophic obstructive cardiomyopathy (HOCM) the obstruction is predominantly in the left ventricular outflow tract (IHSS). In a minority of cases the obstruction is strictly located in midventricle (midventricular obstruction, MO). Hypertrophic nonobstructive cardiomyopathy (HNCM) includes asymmetric septal hypertrophy (ASH) and apical hypertrophy (AH). Right ventricular hypertrophic obstruction (RVHO) is an uncommon type of HCM and is almost always combined with other types of left ventricular HCM. We describe in the present report 1 case of RVHO with IHSS, 2 cases with MO and, to our knowledge, the first case with AH.     

Single-dose response kinetics of cyclosporine

Cyclosporine (Cy) dose-response kinetics were studied in 8 renal failure patients awaiting kidney transplantation. All patients received a single oral dose of Cy (7 mg/kg). Blood samples were drawn frequently before and until 4 days after Cy administration. Cy blood levels were measured by radioimmunoassay (RIA). OKT3-induced in vitro proliferation of simultaneously isolated lymphocytes was determined by H3-thymidine incorporation. T cell subpopulations were enumerated using a peroxidase-antiperoxidase method. Mean Cy blood level reached its peak (Cmax = 1,466 +/- 186 ng/ml) at 4 to 6 hours, the elimination half life (t1/2) measured 31 +/- 7.2 hours. The T4/T8 cell ratio did not change during the study, the total numbers of T3, T4 and T8 positive lymphocytes showed well known circadian variations without an apparent influence of Cy. There was a strong relationship between Cy blood levels and the inhibition of in vitro lymphocyte proliferation (y = 21.1 -0.007x, r = -0.91, p less than 0.001). With decreasing Cy blood concentrations the proliferative potency of lymphocytes was restored without delay in time. In conclusion circulating T cell subpopulations are not influenced by a single dose of Cy, the strong correlation between drug levels and the inhibition of lymphoproliferation suggest that RIA derived Cy blood concentrations are a valuable tool for estimating immunosuppression.