Effects of pulsatile minimal invasive extracorporeal circulation on fibrinolysis and organ protection in adult cardiac surgery-a prospective randomized trial

2021 MiECTiS focused update on the 2016 position paper for the use of minimal invasive extracorporeal circulation in cardiac surgery

The landmark 2016 Minimal Invasive Extracorporeal Technologies International Society (MiECTiS) position paper promoted the creation of a common language between cardiac surgeons, anesthesiologists and perfusionists which led to the development of a stable framework that paved the way for the advancement of minimal invasive perfusion and related technologies. The current expert consensus document offers an update in areas for which new evidence has emerged. In the light of published literature, modular minimal invasive extracorporeal circulation (MiECC) has been established as a safe and effective perfusion technique that increases biocompatibility and ultimately ensures perfusion safety in all adult cardiac surgical procedures, including re-operations, aortic arch and emergency surgery. Moreover, it was recognized that incorporation of MiECC strategies advances minimal invasive cardiac surgery (MICS) by combining reduced surgical trauma with minimal physiologic derangements. Minimal Invasive Extracorporeal Technologies International Society considers MiECC as a physiologically-based multidisciplinary strategy for performing cardiac surgery that is associated with significant evidence-based clinical benefit that has accrued over the years. Widespread adoption of this technology is thus strongly advocated to obtain additional healthcare benefit while advancing patient care.

A novel pulsatile blood pump design for cardiothoracic surgery: Proof-of-concept in a mock circulation

BACKGROUND

Pulsatile perfusion during extracorporeal circulation is a promising concept to improve perfusion of critical organs. Clinical benefits are limited by the amount of pulsatile energy provided by standard pumps. The present study investigated the properties of a novel positive displacement blood pump in a mock circulation.

METHODS

The pump was attached to an aortic model with a human-like geometry and compliance as a pseudo patient. Hemodynamic data were recorded while the pump settings were adjusted systematically.

RESULTS

Using a regular oxygenator, maximum flow was 2.6 L/min at a pressure of 27 mm Hg and a frequency (F) of 90 bpm. Pulse pressure (PP; 28.9 mm Hg) and surplus hemodynamic energy (SHE; 26.1% of mean arterial pressure) were highest at F = 40 bpm. Flow and pressure profiles appeared sinusoid. Using a low-resistance membrane ventilator to assess the impact of back pressure, maximum flow was 4.0 L/min at a pressure of 58.6 mm Hg and F = 40 bpm. At F = 40 bpm, PP was 58.7 mm Hg with an SHE of 33.4%. SHE decreased with increasing flow, heart rate, and systolic percentage but surpassed 10% with reasonable settings.

CONCLUSIONS

The present prototype achieved sufficient flow and pressure ranges only in the presence of a low-resistance membrane ventilator. It delivered supraphysiologic levels of pulse pressure and SHE. Further modifications are planned to establish this concept for adult pulsatile perfusion.

Application of ultrasound microbubble contrast to evaluate the effect of sitaxentan on renal microvascular perfusion in beagles undergoing cardiopulmonary bypass

BACKGROUND & OBJECTIVE

We aimed to evaluate the effect of sitaxentan on renal microvascular perfusion via application of ultrasound microbubble contrast.

METHODS

Male beagles were randomly divided into: Sham, cardiopulmonary bypass (CPB) and sitaxentan-infused (Sit) groups (n = 6). The ascending slope rate (ASR), area under the curve (AUC), derived peak intensity, and time to peak (TTP) were obtained via ultrasound microbubble contrast before CPB (T1), after 1 h CPB (T2), at end of CPB (T3), and 2 h after CPB (T4).

RESULTS

Compared with the Sham group, the CPB group had lower ASR of the renal cortex and medulla at T2 - 4, higher AUC and TTP at T3 - 4, and lower derived peak intensity at T4. The ASR at T2 - 4 in the Sit group was lower, TTP was higher at T2 - 4, and AUC was higher at T3 - 4 (P < 0.05). Compared with the CPB group, the Sit group had higher ASR of the renal cortex and medulla at T3 - 4 and AUC and TTP at T3 - 4 (P < 0.05). Compared with that at T1, the ASR of the renal cortex and medulla at T2 - 4 in the CPB group was lower, and AUC and TTP were higher at T3 - 4. The ASR of the renal cortex and medulla at T2 - 4 in the Sit group was lower, TTP was higher at T2 - 4, and AUC was higher at T4 (P < 0.05).

CONCLUSIONS

Ultrasound microbubble contrast could be effectively used to evaluate renal microvascular perfusion peri-CPB in beagles, which was prone to decrease and could be improved via pretreatment with sitaxentan.