Evaluation of Pulsatile and Nonpulsatile Flow in Microvessels of the Bulbar Conjunctiva in the Goat with an Undulation Pump Artificial Heart

Baba, Atsushi; Dobšák, Petr; Mochizuki, Shuichi; Saito, Itsuro; Igarashi, Takashi; Takiura, Koki; Shibata, Masahiro; Abe, Yusuke; Chinzei, Tsuneo; Vasků, J; Imachi, Kou

doi:10.1046/j.1525-1594.2003.00027.x

Cited by 33 publications

(21 citation statements)

References 11 publications

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“…It has indeed been shown that the absence of pulsatility is associated with capillary fall out, endothelial damage, endotoxin translocation and the production of cytokines, endothelin-1, lactate and catecholamines (2,33,41,42). Interestingly, Sezai et al (33) showed that the increased production of endothelin-1 with nonpulsatile flow starts no earlier than after weaning from cardiopulmonary bypass, simultaneously with impairment of microcirculatory recovery as shown in our investigation.…”

Section: Discussionmentioning

confidence: 99%

Pulsatile flow during cardiopulmonary bypass preserves postoperative microcirculatory perfusion irrespective of systemic hemodynamics

Koning¹,

Vonk²,

Barneveld³

et al. 2012

Journal of Applied Physiology

110

103

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The onset of nonpulsatile cardiopulmonary bypass is known to deteriorate microcirculatory perfusion, but it has never been investigated whether this may be prevented by restoration of pulsatility during extracorporeal circulation. We therefore investigated the distinct effects of nonpulsatile and pulsatile flow on microcirculatory perfusion during on-pump cardiac surgery. Patients undergoing coronary artery bypass graft surgery were randomized into a nonpulsatile ( n = 17) or pulsatile ( n = 16) cardiopulmonary bypass group. Sublingual mucosal microvascular perfusion was measured at distinct perioperative time intervals using sidestream dark field imaging, and quantified as the level of perfused small vessel density and microvascular flow index (vessel diameter < 20 μm). Microcirculation measurements were paralleled by hemodynamic and free hemoglobin analyses. The pulse wave during pulsatile bypass estimated 58 ± 17% of the baseline blood pressure waveform. The observed reduction in perfused vessel density during aorta cross-clamping was only restored in the pulsatile flow group and increased from 15.5 ± 2.4 to 20.3 ± 3.7 mm/mm2upon intensive care admission ( P < 0.01). The median postoperative microvascular flow index was higher in the pulsatile group [2.6 (2.5–2.9)] than in the nonpulsatile group [2.1 (1.7–2.5); P = 0.001]. Pulsatile flow was not associated with augmentation of free hemoglobin production and was paralleled by improved oxygen consumption from 70 ± 14 to 82 ± 16 ml·min−1·m−2( P = 0.01) at the end of aortic cross-clamping. In conclusion, pulsatile cardiopulmonary bypass preserves microcirculatory perfusion throughout the early postoperative period, irrespective of systemic hemodynamics. This observation is paralleled by an increase in oxygen consumption during pulsatile flow, which may hint toward decreased microcirculatory heterogeneity during extracorporeal circulation and preservation of microcirculatory perfusion throughout the perioperative period.

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Section: Discussionmentioning

confidence: 99%

Pulsatile flow during cardiopulmonary bypass preserves postoperative microcirculatory perfusion irrespective of systemic hemodynamics

Koning¹,

Vonk²,

Barneveld³

et al. 2012

Journal of Applied Physiology

110

103

View full text Add to dashboard Cite

show abstract

“…Their results showed that pulsatile flow exists at the microcirculation level; and during non-pulsatile perfusion, the flow distribution is not homogeneous when compared with pulsatile perfusion. Baba et al [13,14] observed the microcirculation on the bulbar conjunctiva with a digital high-definition microscope to investigate the different flow patterns on the microcirculation on a goat with a total artificial heart. They believed that pulsatile flow enhances the basal and flow-stimulated endothelin release in microvessels, and that there was a possibility that non-pulsatile perfusion caused microvascular dysfunction, which could become more severe with prolonged non-pulsatile ventricular assist device (VAD) support or permanent non-pulsatile artificial heart implantation.…”

Section: Direct Evidence Of the Pulsatile Effect On The Microcirculatmentioning

confidence: 99%

Review Article: Comparison of perfusion modes on microcirculation during acute and chronic cardiac support: is there a difference?

Ündar

2007

Perfusion

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Although heart-lung machines and cardiac assist devices have been used successfully for acute and chronic cardiac support for decades, controversies still remain concerning the benefits of pulsatile and non-pulsatile perfusion. The core of the debate is whether enough energy is generated by the artificial pulse to keep capillary beds open and cell metabolism stabilized during acute or chronic cardiac support. In other words, does artificial pulsatility exist in the microcirculation: small vessels of less than 100 microm in diameter? Many investigators have tried to use different tools and biomarkers to reflect directly or indirectly the state of the microcirculation when comparing the two different perfusion modes during acute and chronic cardiac support. However, the results are controversial. First, direct observation of the state of the microcirculation during acute and chronic cardiac support is limited; and reports concerning direct observation of the microcirculation with different perfusion modes in contemporary literature are rare. Secondly, different investigators have used their own criteria to define pulsatile flow. Therefore, it is necessary to develop more efficient methodologies, enabling direct observation of the microcirculation during acute and chronic cardiac support and also establish common criteria that will precisely quantify the pulsatile flow in terms of energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE) levels. Using these critical parameters may explain how excess energy is created by pulsatile flow and maintains perfusion through the microcirculation by ensuring capillary patency.

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“…They are linked neurohumourally and hemodynamically (e.g. 2,8,9 Accordingly, the present retrospective study was to investigate changes in PF post-LVAD placement in relation to the haemodynamic changes and their association with survival. 5 Structural and functional alterations of the lungs in HF are well described 5,6 and correlate to HF severity and patient survival.…”

Section: Introductionmentioning

confidence: 99%

Pulmonary function assessment post‐left ventricular assist device implantation

et al. 2018

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AimThe lungs—and particularly the alveolar‐capillary membrane—may be sensitive to continuous flow (CF) and pulmonary pressure alterations in heart failure (HF). We aimed to investigate long‐term effects of CF pumps on respiratory function.Methods and resultsWe conducted a retrospective study of patients with end‐stage HF at our institution. We analysed pulmonary function tests [e.g. forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)] and diffusing capacity of the lung for carbon monoxide (D LCO) from before and after left ventricular assist device (LVAD) implantation and compared them with invasive haemodynamic studies. Of the 274 patients screened, final study analysis involved 44 patients with end‐stage HF who had CF LVAD implantation between 1 February 2007 and 31 December 2015 at our institution. These patients [mean (standard deviation, SD) age, 50 (9) years; male sex, n = 33, 75%] received either the HeartMate II (Thoratec Corp.) pump (77%) or the HeartWare (HeartWare International Inc.) pump. The mean (SD) left ventricular ejection fraction was 21% (13%). At a median of 237 days post‐LVAD implantation, we observed significant D LCO decrease (−23%) since pre‐implantation (P < 0.001). ΔD LCO had an inverse relationship with changes in pulmonary capillary wedge pressure (PCWP) and right atrial pressure (RAP) from pre‐LVAD to post‐LVAD implantation: ΔD LCO to ΔPCWP (r = 0.50, P < 0.01) and ΔD LCO to ΔRAP (r = 0.39, P < 0.05). We observed other reductions in FEV1, FVC, and FEV1/FVC between pre‐LVAD and post‐LVAD implantation. In mean (SD) values, FEV1 changed from 2.3 (0.7) to 2.1 (0.7) (P = 0.005); FVC decreased from 3.2 (0.8) to 2.9 (0.9) (P = 0.01); and FEV1/FVC went from 0.72 (0.1) to 0.72 (0.1) (P = 0.50). Landmark survival analysis revealed that ΔD LCO from 6 months after LVAD implantation was predictive of death for HF patients [hazard ratio (95% confidence interval), 0.60 (0.28–0.98); P = 0.03].ConclusionsPulmonary function did not improve after LVAD implantation. The degree of D LCO deterioration is related to haemodynamic status post‐LVAD implantation. The ΔD LCO within 6 months post‐operative was associated with survival.

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Evaluation of Pulsatile and Nonpulsatile Flow in Microvessels of the Bulbar Conjunctiva in the Goat with an Undulation Pump Artificial Heart

Cited by 33 publications

References 11 publications

Pulsatile flow during cardiopulmonary bypass preserves postoperative microcirculatory perfusion irrespective of systemic hemodynamics

Pulsatile flow during cardiopulmonary bypass preserves postoperative microcirculatory perfusion irrespective of systemic hemodynamics

Review Article: Comparison of perfusion modes on microcirculation during acute and chronic cardiac support: is there a difference?

Pulmonary function assessment post‐left ventricular assist device implantation

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