Comparative clinical study of pulsatile and non-pulsatile perfusion in 350 consecutive patients.

Abstract

Pulsatile perfusion has been shown to offer significant haemodynamic advantages over non-pulsatile perfusion in many experimental studies. Clinical acceptance of pulsatile perfusion during cardiac surgical procedures has, however, been hampered by the lack of technologically satisfactory pulsatile pump systems, and by inadequate clinical experience of routine use of pulsatile perfusion. The recent introduction of reliable pulsatile pump systems with low haemolysis characteristics has made possible the clinical validation of the previous experimental studies. We describe the results of a prospective study of mortality, haemodynamic morbidity, and haematological status, in 350 consecutive adult patients submitted to cardiopulmonary bypass procedures in a surgical unit over a 12-month period. One hundred and seventy five patients were perfused with conventional non-pulsatile flow and 175 with pulsatile flow, using a modified roller-pump pulsatile system (Cobe-Stockert). The groups were closely similar in terms of preoperative characteristics, referral category, and pathology requiring surgery. Operative techniques, bypass parameters, and anaesthetic regime were standardised in both groups. The results were as follows. (1) Total mortality was significantly lower in the pulsatile group (4.6%) compared with the non-pulsatile group (10.3%), p = 006. (2) The incidence of deaths attributable to post-perfusion low cardiac output was significantly lower in the pulsatile group (11% compared with 6 3 %, p = 0.02). (3) Requirement for mechanical (intra-aortic balloon) or drug circulatory support was significantly lower in the pulsatile group. (4) The use of pulsatile perfusion was not associated with any increase in haemolysis, blood cell depletion, or postoperative bleeding problems.Interest in the clinical applicability of pulsatile perfusion has recently been reawakened, both as a result of the development of reliable, commercially available pump systems and in view of recent clinical research defining more clearly the pathophysiological effects of non-pulsatile perfusion.A prospective clinical study was designed to investigate the clinical applicability of routine pulsatile flow during open-heart procedures, with particular emphasis on the comparative effects of pulsatile and non-pulsatile perfusion on haemodynamic morbidity and mortality statistics. The following specific aims were included in the study.

Structure and adaptation of arteries to pulsatile flow: The case of the ascending aorta

“…(2) and (4)] by using the real values of various arterial bifurcations. For this purpose we used the extensive dataset of diameters, lengths and distensibilities of arteries provided in Ref.…”

Heart rate, arterial distensibility, and optimal performance of the arterial tree

“…It has been long recognized that pulsatile blood flow performs the best than continuous flow because it induces both lower total peripheral resistance and mean arterial pressure (Mavroudis, 1978), and also better blood perfusion (Taylor et al, 1982). The distensibility coefficient of the vessel wall is defined as β ¼ ð2=DÞðdD=dPÞ where P is pressure within the vessel, and D is vessel diameter.…”

Mechanical circulatory support with the ABIOMED BVS 5000: The Toronto General Hospital experience

“…It has been easier for nurses to manage and has required no added personnel for device management -unlike ECMO support, which requires an attending perfusionist. The device provides pulsatile flow, which has been documented to improve clinical outcome (7,8), myocardial blood flow (9) and splanchnic perfusion (10), to reduce systemic vascular resistance and to attenuate catecholamine response (11). In addition, the device functions independent of cardiac rhythm and can provide support during potentially fatal arrhythmias (12,13).…”