Coronary anastomotic devices: blood-exposed non-intimal surface and coronary wall stress

This study compares the area of blood-exposed non-intimal surface in device-constructed anastomoses with the conventionally sutured anastomosis and examines the technical feasibility of 0 blood-exposed non-intimal surface anastomosis configurations.

In the device-constructed anastomosis, blood-exposed non-intimal surface was estimated in all anastomosis configurations identified in truly new (ie, nonduplicate and nonrelated) patent applications and in anastomotic devices recently introduced by several institutions. In the sutured anastomosis, blood-exposed non-intimal surface area was estimated by analysis of previously investigated anastomoses. In 0 blood-exposed non-intimal surface anastomosis configurations, finite element modeling was used to calculate coronary wall stress.

By the end of 2001, 57 truly new applications for the distal coronary anastomosis had been published, categorized in 11 types of anastomosis configurations. The tissue blood-exposed non-intimal surface area (ie, non-intimal tissue surface area) ranged from 0 to 6 mm(2). Approximate total blood-exposed non-intimal surface areas (ie, sum of tissue blood-exposed non-intimal surface and foreign body surface area) in recent devices are 80 mm(2) (GraftConnector, Jomed, Helsingborg, Sweden); 33 mm(2) (Magnetic Vascular Positioner rings, Ventrica, Inc, Fremont, Calif); 4.3 mm(2) (distal connector of St Jude Medical, Inc, St Paul, Minn); and 0.3 mm(2) (Crinoline frame, University Medical Center Utrecht/Delft University of Technology, The Netherlands). The sutured anastomoses, in contrast, contained approximately 1.3 mm(2) blood-exposed non-intimal surface area. The mean peak porcine coronary wall stress in 0 blood-exposed non-intimal surface anastomosis configurations with greater than 90 degrees arteriotomy edge eversion ranges from 0.4 to 0.8 N/mm(2) compared with the mean porcine coronary tear stress of 0.8 N/mm(2).

In recently introduced devices for clinical use, the total blood-exposed non-intimal surface area ranges from 4.3 to 80 mm(2) compared with 1.3 mm(2) in sutured anastomoses. The blood-exposed non-intimal surface area depends on anastomotic orifice size, wall thickness, and bonding components' location and size. Deforming the coronary wall to most of the 0 blood-exposed non-intimal surface anastomosis configurations leads to dangerously high stress concentrations in the coronary arteriotomy corners.