Understanding coronary artery bypass transit time flow curves: role of bypass graft compliance

Jelenc, Marjetka; Jelenc, Blaž; Klokočovnik, Tomislav; Lakič, Nikola; Geršak, Borut; Kneževič, Ivan

doi:10.1093/icvts/ivt457

Cited by 14 publications

(16 citation statements)

References 13 publications

(13 reference statements)

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“…Repositioning of the heart into anatomical position at the end of surgery will obscure the distal end of the graft. Consequently, TTFM measurement is often performed proximally on right-sided grafts, where PI is usually higher, as the high pressured forward flow from the aorta results in higher systolic peak flows in the proximal segment of a by-pass graft and hence in a bigger difference between maximum flow and minimum flow [ 9 ] , as further explained in the following. In theory, a slightly higher PI may well be expected in grafts anastomosed to the left territory, as the PI is obtained by dividing the difference between maximum and minimum flow by the mean flow: .…”

Section: Discussionmentioning

confidence: 99%

“…Ultrasound gel was applied to the lumen of the probe so that the graft occupied a minimum of 75% of the lumen. During TTFM measurement, the ultrasound probe was placed as close as possible to the distal anastomosis for the most accurate reading of the flow dynamics across the anastomosis, as previous studies have demonstrated slightly lower %DF and higher PI in the proximal compared to the distal segment of a by-pass graft [ 9 ] . TTFM measurements are routinely measured at a mean systemic blood pressure of 75–85 mmHg to exclude the effects on flow of excessively low or high blood pressure.…”

Section: Methodsmentioning

confidence: 99%

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Influence of coronary territory on flow profiles of saphenous vein grafts

Amin

Werner

Madsen

et al. 2018

J Cardiothorac Surg

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BackgroundDiffering perfusion of the left and right ventricular coronary territory may influence flow-profiles of saphenous vein grafts (SVGs). We compared flow parameters, measured by transit-time flowmetry (TTFM), in left- and right-sided SVGs during coronary artery by-pass grafting (CABG).MethodsRoutine TTFM measurements were obtained in 167 SVGs to the left territory (55%) and 134 SVGs to the right territory (total of 301 SVGs in 207 patients). The four standard TTFM parameters, [mean graft flow (MGF), pulsatility index (PI), percentage diastolic filling (%DF), and percentage backward flow (%BF)] were compared. Differences in flow parameters were also examined according to surgical technique (on- vs. off-pump).ResultsNo significant difference between coronary territories was found for MGF, PI and %BF. However, a higher %DF was noted in left-sided SVGs in the overall cohort as well as in the on-pump (both p < 0.001) and the off-pump cohorts (p = 0.07). Further, a significantly higher %BF was found in SVGs performed off-pump to the left territory (1.2 ± 2.5 vs. 2.3 ± 3.0, p = 0.023). In a multivariate regression analysis, anastomosing a SVG to the left territory was weakly associated with higher PI (OR = 0.36, p = 0.026) and strongly associated with higher %DF (OR = 5.1, p < 0.001). No significant association was found for MGF, PI, %DF or %BF in either the on-pump nor the off-pump cohorts.ConclusionsAlthough statistically significant, the established differences in TTFM parameters between left- and right-sided vein grafts were small and unlikely to be of clinical relevance.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Influence of coronary territory on flow profiles of saphenous vein grafts

Amin

Werner

Madsen

et al. 2018

J Cardiothorac Surg

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“…We are aware of the fact that other nontechnical factors such as the myocardial temperature, the composition and the temperature of the cardioplegia, and the extension and the resistence of the graft and coronary vascular bed may influence the flow at the anastomosis. To overcome this possible bias we have learned from experience that a minimal value of 15 mL/min is easily obtainable with an optimal anastomosis and is independent from nontechnical factors.…”

Section: Discussionmentioning

confidence: 99%

On Pump Evaluation of the Anastomotic Patency of In Situ Arterial Grafts

et al. 2014

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“…Transit-time ow measurement was performed with VeriQ System (Medi-StimAS, Oslo, Norway) after all anastomoses, ventricle and valves reconstructions were completed, the heart-lung machine was disconnected and hemodynamic parameters became stable (mean arterial pressure xed of 75-85 mmHg) [3,22]. Flow parameters recorded in this study included mean graft ow (Q, ml/min), higher pulsatility index (PI), and diastolic lling (DF, %).…”

Section: Ttfm and Evaluation Criteria For Anastomosis Satisfactorymentioning

confidence: 99%

The preoperative myocardial perfusion and internal mammary artery graft blood flow relationship in patients with ischemic cardiomyopathy

Gutor

Андреев

Мочула

et al. 2022

Preprint

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Objective. The purpose of this study was to determine whether myocardial perfusion in stress/rest conditions estimated by SPECT can be used to predict transit time blood flow characteristics and early graft failure in left internal mammary artery (LIMA) to left anterior descending artery (LAD) grafts in patients with ischemic cardiomyopathy.Methods. The study group consisted of 47 patients with ischemic cardiomyopathy. Intraoperative transit-time flow measurement (TTFM) of LIMA to LAD grafts were performed in all patients. All patients were also examined with preoperative stress and rest myocardial perfusion SPECT with 99mTc-MIBI. Anastomotic patency was considered satisfactory with a normal waveform of blood flow, diastolic-dominant blood filling, and a mean flow value greater than 11.5 ml/min.Results. All 47 patients with LIMA to LAD grafts were divided into two groups; those with graft satisfactory patency (n=40) and those with unsatisfactory patency (n=7) as determined by TTFM. We found differences among these groups in global summed rest score (t=3.7, p=0.003), total perfusion deficit (t=3.0, p=0.014), and LAD territory TPD (t=2.4, p=0.04) characteristics in preoperative rest myocardial perfusion SPECT imaging. Additionally, the flow characteristics were different in patients with and without surgical left ventricle reconstruction (U=153.5, p=0.012).Conclusions. Preoperative myocardial perfusion characteristics have associations with blood flow in LIMA to LAD graft in patients with ischemic cardiomyopathy and LAD territory rest TPD have the potential to be a predictor of early graft failure.

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Understanding coronary artery bypass transit time flow curves: role of bypass graft compliance

Cited by 14 publications

References 13 publications

Influence of coronary territory on flow profiles of saphenous vein grafts

Influence of coronary territory on flow profiles of saphenous vein grafts

On Pump Evaluation of the Anastomotic Patency of In Situ Arterial Grafts

The preoperative myocardial perfusion and internal mammary artery graft blood flow relationship in patients with ischemic cardiomyopathy

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