Ultrasonic differential travel time flow measurement in liquids with suspended granular solids

2020 ◽  
Vol 148 (4) ◽  
pp. 2461-2461
Author(s):  
Max Deffenbaugh ◽  
Timothy Thiel ◽  
Chinthaka Gooneratne ◽  
Albert J. Williams
Keyword(s):  
Travel Time ◽  
Flow Measurement ◽  
Granular Solids ◽  
Time Flow

scholarly journals The application of intraoperative transit time flow measurement to accurately assess anastomotic quality in sequential vein grafting

2013 ◽  
Vol 17 (6) ◽  
pp. 938-943 ◽  
Author(s):  
Yang Yu ◽  
Fan Zhang ◽  
Ming-Xin Gao ◽  
Hai-Tao Li ◽  
Jing-Xing Li ◽  
...  
Keyword(s):  
Transit Time ◽  
Flow Measurement ◽  
Time Flow

Roles of Transit-Time Flow Measurement for Coronary Artery Bypass Surgery

2018 ◽  
Vol 66 (06) ◽  
pp. 426-433 ◽  
Author(s):  
Yasushi Takagi ◽  
Yoshiyuki Takami
Keyword(s):  
Coronary Artery ◽  
Coronary Artery Bypass ◽  
Transit Time ◽  
Graft Failure ◽  
Flow Measurement ◽  
Coronary Artery Bypass Surgery ◽  
Coronary Circulation ◽  
Artery Bypass ◽  
Flow Characteristics ◽  
Time Flow

AbstractTransit-time flow measurement (TTFM) has been increasingly applied to detect graft failure during coronary artery bypass grafting (CABG), because TTFM is less invasive, more reproducible, and less time consuming. Many authors have attempted to validate TTFM and to gain the clear cutoff values and algorithm in TTFM to predict graft failure. The TTFM technology has also been shown to be a useful tool to investigate CABG graft flow characteristics and coronary circulation physiology. It is important to recognize the practical roles of TTFM in the cardiac operating room by review and summarize the literatures.

scholarly journals Improving coronary artery bypass grafting: a systematic review and meta-analysis on the impact of adopting transit-time flow measurement

2019 ◽  
Vol 56 (4) ◽  
pp. 654-663 ◽  
Author(s):  
Daniel J F M Thuijs ◽  
Margreet W A Bekker ◽  
David P Taggart ◽  
A Pieter Kappetein ◽  
Teresa M Kieser ◽  
...  
Keyword(s):  
Systematic Review ◽  
Coronary Artery ◽  
Coronary Artery Bypass Grafting ◽  
Coronary Artery Bypass ◽  
Flow Measurement ◽  
Meta Analysis ◽  
Artery Bypass ◽  
Bypass Grafting ◽  
Predictive Values ◽  
Time Flow

Summary Despite there being numerous studies of intraoperative graft flow assessment by transit-time flow measurement (TTFM) on outcomes after coronary artery bypass grafting (CABG), the adoption of contemporary TTFM is low. Therefore, on 31 January 2018, a systematic literature search was performed to identify articles that reported (i) the amount of grafts classified as abnormal or which were revised or (ii) an association between TTFM and outcomes during follow-up. Random-effects models were used to create pooled estimates with 95% confidence intervals (CI) of (i) the rate of graft revision per patient, (ii) the rate of graft revision per graft and (iii) the rate of graft revision among grafts deemed abnormal based on TTFM parameters. The search yielded 242 articles, and 66 original articles were included in the systematic review. Of those articles, 35 studies reported on abnormal grafts or graft revisions (8943 patients, 15 673 grafts) and were included in the meta-analysis. In 4.3% of patients (95% CI 3.3–5.7%, I2 = 73.9) a revision was required and 2.0% of grafts (95% CI 1.5–2.5%; I2 = 66.0) were revised. The pooled rate of graft revisions among abnormal grafts was 25.1% (95% CI 15.5–37.9%; I2 = 80.2). Studies reported sensitivity ranging from 0.250 to 0.457 and the specificity from 0.939 to 0.984. Reported negative predictive values ranged from 0.719 to 0.980 and reported positive predictive values ranged from 0.100 to 0.840. This systematic review and meta-analysis showed that TTFM could improve CABG procedures. However, due to heterogeneous data, drawing uniform conclusions appeared challenging. Future studies should focus on determining the optimal use of TTFM and assessing its diagnostic accuracy.

scholarly journals Transit-time flow measurement verifies patency of coronary artery grafts: An observational study

2015 ◽  
Vol 24 ◽  
pp. e19-e20
Author(s):  
Mohammad R. Azari ◽  
Ajay Hirikannawar ◽  
Hugh Wolfenden ◽  
Bruce French ◽  
Manish Jain ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Observational Study ◽  
Transit Time ◽  
Flow Measurement ◽  
Time Flow

The Accuracy of Transit Time Flow Measurement in Predicting Graft Patency after Coronary Artery Bypass Grafting

2013 ◽  
Vol 8 (6) ◽  
pp. 416-419 ◽  
Author(s):  
Patrick F. Walker ◽  
William T. Daniel ◽  
Emmanuel Moss ◽  
Vinod H. Thourani ◽  
Patrick Kilgo ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Coronary Artery Bypass Grafting ◽  
Transit Time ◽  
Pulsatility Index ◽  
Flow Measurement ◽  
Artery Bypass ◽  
Graft Patency ◽  
Bypass Grafting ◽  
Flow Measurements ◽  
Time Flow

Objective Transit time flow measurement (TTFM) is a method used to assess intraoperative blood flow after vascular anastomoses. Angiography represents the criterion standard for the assessment of graft patency after coronary artery bypass grafting (CABG). The purpose of this study was to compare flow measurements from TTFM to diagnostic angiography. Methods From October 9, 2009, to April 30, 2012, a total of 259 patients underwent robotic-assisted CABG procedures at a single institution. Of these, 160 patients had both TTFM and either intraoperative or postoperative angiography of the left internal mammary artery to the left anterior descending coronary artery graft. Transit time flow measurements were obtained after completion of the anastomosis and after administration of protamine before chest closure. Transit time flow measurement assessment included pulsatility index, diastolic fraction, and flow (milliliters per minute). Angiograms were graded according to the Fitzgibbon criteria. The patients were grouped according to angiographic findings, with perfect grafts defined as FitzGibbon A and problematic grafts defined as either Fitzgibbon B or O. Results Overall, there were 152 (95%) of 160 angiographically perfect grafts (FitzGibbon A). Of the eight problematic grafts, five were occluded (Fitzgibbon O) and three had significant flow-limiting lesions (FitzGibbon B). Two patients had intraoperative graft revision after completion angiography, one had redo CABG during the same hospitalization, and five were treated with percutaneous coronary intervention. A significant difference was seen in mean ± SD flow (34.3 ± 16.8 mL/min vs 23.9 ± 12.5 mL/min, P = 0.033) between patent and nonpatent grafts but not in pulsatility index (1.98 ± 0.76 vs 1.65 ± 0.48, P = 0.16) or diastolic fraction (73.5% ± 8.45% vs 70.9% ± 6.15%, P = 0.13). Conclusions Although TTFM can be a useful tool for graft assessment after CABG, false negatives can occur. Angiography remains the criterion standard to assess graft patency and quality of the anastomosis after CABG.

Enhancement of flow measurement for graft verification

2019 ◽  
Vol 27 (8) ◽  
pp. 646-651
Author(s):  
Yury Y Vechersky ◽  
Vasily V Zatolokin ◽  
Boris N Kozlov ◽  
Aleksandra A Nenakhova ◽  
Vladimir M Shipulin
Keyword(s):  
Coronary Artery ◽  
Transit Time ◽  
Flow Measurement ◽  
Artery Bypass ◽  
Coronary Bypass ◽  
Flow Measurements ◽  
Technical Problems ◽  
Technical Errors ◽  
Time Flow ◽  
Coronary Bypass Grafts

Background We aimed to evaluate multiple transit-time flow measurements during coronary artery bypass grafting. Methods Transit-time flow measurements were performed first on the arrested heart both with and without a proximal snare on the target coronary artery, second, after weaning from cardiopulmonary bypass, and third, before chest closure. Results Among the 214 grafts considered, 9 (4.2%) were patent and 6 (2.8%) were failing. In the failed grafts, an abnormal transit-time flow was found during the first measurement, in 5 (2.3%) cases with a proximal snare and in one (0.47%) without a snare. In these cases, technical errors with the distal anastomoses were found and immediately corrected. A problem with the proximal anastomosis was found in one graft during the second measurement and corrected right away. Bending due to excessive length was found in 2 (0.93%) grafts during the third measurement, and graft repositioning was performed. The first transit-time flow measurement showed that mean graft flow was significantly decreased with a proximal snare compared to without a proximal snare, throughout the entire coronary territory. Pulsatility index during the first transit-time flow measurement was higher with a proximal snare than without one. Conclusions The 3-time transit-time flow measurement strategy makes it possible to verify and immediately correct technical problems with coronary bypass grafts.

Sign in / Sign up

Export Citation Format

Share Document