Diagnostic accuracy of Doppler ultrasonography for assessment of internal thoracic artery graft patency

Abstract

Objective: The main purpose of this study was to assess the patency of left internal thoracic artery (LITA) graft by using color Doppler ultrasonography (CDUSG) and furthermore to determine the sensitivity and specificity of CDUSG for patency by using coronary angiography as the reference standard. Methods: This study is an observational cohort study on diagnostic accuracy that was held between August 2008 and October 2009. CDUSG was performed in 138 consecutive patients who had angina symptom or positive ischemic findings following coronary artery bypass surgery. LITA blood flow velocity at peak-systole (PSV), diastole (PDV) and end-diastole (EDV) was recorded. All patients were also assessed by coronary angiography for LITA graft patency. Statistical analysis was performed by using independent samples t-test, Mann-Whitney-U test, chisquare test and receiver operating curve analyses (ROC). Results: Seventy-eight of all patients had functional LITA grafts and 59 patients had dysfunctional LITA grafts according to CDUSG-derived parameters, whereas we cannot conclude about one patient's LITA graft functionality. The LITA grafts were visualized angiographically in all cases. Of all 138 patients, 60 patients had dysfunctional LITA grafts after angiographic evaluation. The ROC analyses showed that PDV (AUC=0.899, 95% CI 0.844 to 0.953; p<0.001) and EDV (AUC=0.900; 95% CI 0.847 to 0.953; p<0.001) values were also strongly associated with graft functionality. We found out that CDUSG predicts LITA graft functionality with a sensitivity and specificity of 100% and 98.4% respectively. The accuracy of the CDUSG was calculated as 99.3%. Conclusion: CDUSG is a reliable non-invasive method for assessment of LITA graft patency. (Anadolu Kardiyol Derg 2014; 14: 286-91)

The Role of Color Doppler Ultrasonography in the Perioperative Period of Coronary Artery Bypass Grafting: Comparison with Transit-Time Flow Measurement

“…As the native course of the LIMA is often modified by the surgery, we choose the left supraclavicular approach yielding a higher detection rate and reproducible detection at repeated scans. The proximal part of the LIMA graft is close to the chest wall and fixed with a soft tissue and hence free from pulsatile displacement [4]. Our rates of LIMA graft visualization are within the range of previous studies reporting 81–98% visualization [23].…”

“…As an adaptation to the coronary circulation, the postoperative LIMA flow pattern becomes biphasic instead of triphasic, with an increased PDV instead of systolic pattern [26, 27]. For the LIMA graft anastomosed to the LAD, postoperative data revealed that the peak diastolic/systolic velocity ratio (D/S) of more than 1.0 has been associated with a good angiographic finding indicating increased blood flow into the low resistance distal coronary arterial bed and probably indicating a patent graft [4]. Mizukami et al [11] reported that a mean D/S <0.57 predicted graft stenosis with a sensitivity, specificity, and accuracy of 88, 91, and 91%, respectively, in patients with left IMA grafts.…”

“…The left internal mammary artery (LIMA) has become the most preferred conduit for revascularization of left anterior descending (LAD) coronary artery nowadays [4-8]. Clinically, the quantity and quality of the graft flow are directly evaluated by an intraoperative transit-time flow measurement (TTFM) that yields the mean graft flow (MGF), pulsatile index (PI), and diastolic flow fraction.…”