An evaluation of the intraoperative transit time measurements of coronary bypass flow

Hirotani, Takashi; Kameda, Tadashi; Shirota, Shogo; Nakao, Yosuke

doi:10.1016/s1010-7940(01)00700-x

Cited by 59 publications

(36 citation statements)

References 11 publications

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“…This could explain that measured blood flow in SVG is significantly lower in the (1G) case than in the (3G) case (Table 2). In other words, as demonstrated by Hirotani et al 10 and Glineur et al, 9 the status of the distal supplied territory influences the flow in the graft.…”

Section: Case (1g): Right Graft Working; No Left Graftsmentioning

confidence: 92%

Analog Electrical Model of the Coronary Circulation in Case of Multiple Revascularizations

Maasrani

Verhoye²,

Drochon³

2008

Ann Biomed Eng

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In this work, we propose an analog electrical model of the coronary circulation for patients with obstructive disease undergoing revascularization. In this clinical situation, the collateral circulation to the occluded artery is difficult to ascertain via preoperative measurements and well-developed collaterals might induce long-term restenosis of the revascularized artery due to flow competition mechanisms. The proposed model allows an original biomechanical analysis of per-operative hemodynamic data in order to assess quantitative evaluation of pressures and flows inside the native stenosed arteries, the collateral network and the bypass grafts. Average cardiac cycle values are analysed. In the case of 3-vessel disease and chronic occlusion of the right coronary artery, the quantitative results confirm the protective effects of the collateral flows in the pathological situation, but also show that the revascularization of the occluded right artery is fully justified since the collateral flows remain low, even when the left territory is revascularized. The model thus provides a computational tool to evaluate therapeutic strategies for each patient.

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Section: Case (1g): Right Graft Working; No Left Graftsmentioning

confidence: 92%

Analog Electrical Model of the Coronary Circulation in Case of Multiple Revascularizations

Maasrani

Verhoye²,

Drochon³

2008

Ann Biomed Eng

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“…The main commercial systems available for this purpose are ultrasonic and electromagnetic devices. The electromagnetic flowmeter is efficient in detecting graft stenosis; however, it is sensitive to the patient hematocrit rate, especially in smaller vessels, such as the internal thoracic artery (Canver et al, 1997;Hirotani et al, 2001;Tabrizchi and Pugsley, 2000).…”

Section: Introductionmentioning

confidence: 99%

Continuous flow phantom for the calibration of an ultrasonic transit-time flowmeter

Silva¹,

Krüger²,

Pereira³

2014

RBEB

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Introduction: Ultrasound Transit-Time flowmeters are based on the fact that the time required for an ultrasound pulse to propagate through a given distance in a moving medium is a function of the vectorial sum of pulse propagation velocity and medium velocity. The most common application of this flowmeter in medicine is in the evaluation of blood flow in arteries and veins during heart vascular surgery. The present article describes the design, construction and evaluation of a flow phantom for transit-time flowmeters calibration. Methods: Basically, it is a hydraulic circuit containing degassed and distilled water. In such a circuit, a constant differential water level is established between two columns that are interconnected by tubes with defined resistance, which determines a known flow rate. A basic theoretical model to estimate the system Reynolds Number and resistance was developed. Results: A flow range between 4.43 ± 0.18 ml.min -1 and 106.88 ± 0.27 ml.min -1 was found to be compatible with physiological values in small vessels. The pressure range was between 0.20 ± 0.03 cmH 2 O and 12.53 ± 0.07 cmH 2 O, and the larger Reynolds Number was 1134.07. Experimental and theoretical resistance values were similar. Conclusion: A reproducible phantom was designed and built to be assembled with standard low-cost materials and is capable of generating adjustable and continuous flows that can be used to calibrate TTFM systems.

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“…Flow pattern is predominantly diastolic in all grafts but is more marked in the left coronary system; because of a smaller right ventricular transmyocardial pressure gradient, there is a comparatively greater systolic flow component in grafts to the right coronary system [2]. A number of studies have reported the usefulness and efficacy of TTFM [10,[12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Takami et al [12,13] described the usefulness of TTFM in the detection of intraoperative graft failure of several types of grafts.…”

Section: Ultrasound Technologymentioning

confidence: 99%

Intraoperative graft assessment during coronary artery bypass surgery

Fukui

2015

Gen Thorac Cardiovasc Surg

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Coronary artery bypass grafting (CABG) is an established revascularization method for treating multivessel coronary artery disease. The goal of CABG is to achieve complete revascularization with a durable, patent graft without reintervention. However, early graft failure, including that associated with technical errors, has been reported. This makes intraoperative verification of graft patency one of the most important ways in which surgeons can reduce the rate of early graft failure. Conventional angiography is considered the gold standard for graft assessment. However, because it is invasive and inconvenient, several alternatives to intraoperative graft assessment have become available that help reduce early graft failure by allowing revision of the anastomosis intraoperatively. The aim of this article is to review the advantages and disadvantages of several intraoperative graft assessment methods for CABG.

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An evaluation of the intraoperative transit time measurements of coronary bypass flow

Abstract: The bypass flow was affected by such a large number of factors that only measuring the bypass flow rate could not sufficiently predict either stenosed or narrowed grafts. However, ITA grafts bypassed to the coronary arteries with less stenosis were shown to more easily become narrowed.

Cited by 59 publications

References 11 publications

Analog Electrical Model of the Coronary Circulation in Case of Multiple Revascularizations

Analog Electrical Model of the Coronary Circulation in Case of Multiple Revascularizations

Continuous flow phantom for the calibration of an ultrasonic transit-time flowmeter

Intraoperative graft assessment during coronary artery bypass surgery

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