Rivetti L A, Gandra S M
Hospital Samaritano, Faculdade Ciências Médicas Santa Casa de São Paulo, Brazil.
Heart Surg Forum. 1998;1(1):30-6.
Clinical or subclinical manifestations of coronary ischemia may occur when the target vessel is temporarily occluded during revascularization of the beating unsupported heart. Laboratory evidence has shown that even when the surface electrocardiogram is normal, action potential duration, conduction velocity, and regional electrocardiogram patterns change during clamping of the target coronary artery. In addition, local trauma to the endothelium and/or adjacent atherosclerotic plaque by encircling snares or mechanical clamps can lead to plaque disruption and late stenosis in the native vessel.
The authors report their experience with a continuous series of patients undergoing coronary grafting on the beating heart using an intraluminal shunt. This simple device maintains distal perfusion and prevents ischemia while at the same time protects the anastomosis from potential suturing errors. The shunt also keeps blood from obscuring the operators vision and thus makes snares and clamps unneccesary. Smooth unhindered removal of the shunt immediately confirms patency of the finished anastomosis.
Off-pump coronary grafting was performed in 501 consecutive patients utilizing an intraluminal shunt. Three hundred and seventy three men (74.5%) and 128 women ranging from 34 to 92 years old (mean 60.4 years) underwent a total of 196 internal mammary artery and 596 saphenous vein grafts (1.58 grafts per patient) from November 1983 to December 1996 at the Santa Casa de São Paulo Hospital and Hospital Samaritano. Mean shunting time was 14 minutes per anastomosis. Thirty day hospital mortality was 1.39% (7 patients) and all deaths were from non-cardiac causes. Perioperative myocardial infarction occurred in 7 other patients (1.39%) all of whom survived.
In selected cases coronary grafts can be safely constructed on the beating heart without ischemia using a simple and inexpensive intraluminal shunt. The device is easily inserted and removed without damage to the native coronary. In a large series of patients, operative mortality and morbidity were lower than with conventional heart-lung support and cardioplegic arrest.
