Internal Mammary Coronary Artery Anastomosis by Co2 Laser: An Acute Experimental Study

A bstract This study was designed to determine the feasibility of anastomosing the internal mammary artery (IMA) and coronary artery with a carbon dioxide laser in a canine model. Twenty-two mongrel dogs were randomly assigned to two groups: group I (n = 11) underwent laser-assisted vascular anastomosis (LAVA) of the left IMA to the left anterior descending (LAD) coronary artery, whereas in group II (n = 11) the anastomosis was done with the conventional technique (handsewn). Laser methodology was used to micro-weld vessels utilizing a power of 200 mW with a spot size of 500 μ, producing an effective power density of 102 W/cm² and energy fluence of 9, 172 joules/cm² in a continuous mode at a distance of 2 cm. The short-term patency rate, measured at 2 hours after completion of the anastomosis, was 100% in both groups. The time required to perform the LAVA in group I was significantly shorter than group II (6.27 ± 0.47 vs 11.6 ± 0.67 min, p < 0.05). The mean anastomotic bursting pressure in group I was significantly lower compared to group II (348 ± 8 vs 402 ± 9 mmHg, p < 0.05). Histologic evaluation of all vessels showed moderate thermal injury of the adventitia and media in the laser group. Scanning electron microscopy exhibited a smooth anastomotic area in group I, whereas endothelial and perianastomotic changes with multiple needle craters occurred in group II (conventional anastomosis). Based on the results of this study, we conclude that a low powered CO₂ laser can be used to safely perform an IMA to LAD artery anastomosis, thus providing an alternative to conventional techniques because of its rapidity and minimization of anastomotic changes.     

Clinical significance of sinusoidal fetal heart rate pattern

Summary. Sinusoidal fetal heart rate pattern has been regarded as a sign of fetal jeopardy and 92 instances of this pattern were analysed. The morphologically different major and minor sinusoidal patterns were assessed with regard to their clinical significance as predictors of fetal compromise. There were 83 instances of minor sinusoidal pattern (amplitude of oscillation <25 beats/min) with only one antepartum fetal death. Major sinusoidal pattern (amplitude of oscillation >25 beats/min) was diagnosed in nine patients and in six of them the fetus died before, during or after delivery. It is concluded that patients with minor sinusoidal heart rate patterns may be managed expectantly, whereas on the rare occasion when a major sinusoidal pattern is seen expeditious delivery is justified.