On-X versus St Jude Medical Mechanical Prosthesis in mitral position: are we moving forward in design technology?

BACKGROUND: Continuous effort is still provided in designing optimal artificial heart valves with better hemodynamic function and reduced thromboembolic potential. The question is do we have moved forward toward this goal or not. METHODS: A prospective, randomized comparative study was done on 360 patients scheduled for elective mitral valve replacement. Patients were grouped into an On-X group (N.=180), who received On-X mechanical valve, and a SJM group (N.=180), who received St Jude mechanical valve. Echocardiographic and clinical assessments were performed for all patients at 6 and 12 months follow-up period. RESULTS: Rheumatic heart disease was the most common cause of valve affection (94.2%). Early mortality was 6.4%. The mean follow-up time was 3.11±2.44 years. No structural or non-structural valvular dysfunction and no thromboembolism cases were encountered. Late valve thrombosis was1.9%/patient-year in On-X group and 2.1%/patient-year in SJM group. The mean EOA was higher in On-X group (2.0±0.3 cm2) than in SJM group (1.9±0.2 cm2), (P≥0.05). The mean EOAI was higher in On-X group (1.1±0.1 cm2/m2) than in SJM group (1.0±0.1 cm2/m2), (P=0.034), especially significant in small valve size (25 mm) where it was 1.09±021 cm2/m2 in On-X group and 0.93±0.12 cm2/m2 in SJM group (P=0.02). CONCLUSIONS: On-X and St Jude prosthetic valves have a comparable hemodynamic performance in mitral position. However, On-X prosthesis might have a forward step on the way of design technology that may allow better function in terms of EOA and EOAI especially in smaller valve size.

Bilateral bidirectional Glenn: outcome of off-pump technique.

OBJECTIVES: Off-pump bilateral bidirectional Glenn (b-BDG) poses a surgical challenge and may add complexity to the postoperative outcome especially regarding uniformity of the anastomosis and central pulmonary artery growth. Herein, we report early- and mid-term outcomes after off-pump b-BDG without using superior vena cava decompression techniques. METHODS: Ninety-seven consecutive patients, between 2009 and 2014, were included in this prospective study. All patients had complete pre- and postoperative clinical and detailed neurological assessments. Diagnosis and follow-up were done by echocardiography and cardiac catheterization for assessment of pulmonary artery anatomically and haemodynamically. Median follow-up period was 3.5 years. Perioperative variables, clinical outcome, morbidity, mortality and follow-up data were recorded. RESULTS: Hypoplastic right ventricle was present in 52 cases (53.6%) and hypoplastic left ventricle was present in 45 cases (46.4%). Mean superior vena cava pressure on clamping was 21.49 ± 3.04 mmHg. Mean total clamping time was 23.11 ± 3.44 min. Mean oxygen saturation increased from preoperative 69.22 ± 6.01% to 83.66 ± 3.97% after b-BDG construction (P-value ≤ 0.0001). The Nakata index increased from 288.47 ± 28.66 mm2/m2 to 303.64 ± 26.85mm2/m2 on follow-up (P-value ≤ 0.05). In-hospital mortality was 4 patients (4.1%) due to low-cardiac output. There were chylothorax in 9 patients (9.3%) and convulsions in 4 patients (4.1%) who were treated conservatively. CONCLUSIONS: Off-pump b-BDG can be conducted safely, with a uniform anastomosis that allows a good central pulmonary artery growth for subsequent Fontan completion. Moreover, avoiding the use of cardiopulmonary bypass is more economic and less hazardous.