Analysis of influencing factors of graft stenosis after left internal mammary artery-left anterior descending coronary artery bypass grafting / 国际外科学杂志

Objective:To explore the influencing factors of postoperative graft stenosis in patients undergoing left internal mammary artery-left anterior descending branch (LIMA-LAD) coronary artery bypass graft (CABG) surgery.Methods:A retrospective analysis of the clinical data of 86 patients who were admitted to the Second Affiliated Hospital of Hainan Medical College and received coronary angiography after CABG surgery from July 2019 to December 2020 due to recurrent chest tightness, chest pain and other symptoms. According to the degree of stenosis of the LIMA-LAD graft, the patients were divided into stenosis group ( n=25) and non-stenosis group ( n=61). The graft stenosis of patients in the stenosis group was ≥50%, and the graft stenosis of patients in the non-stenotic group was less than 50%. The general information, past medical history, CABG intraoperative data, current visit data and biochemical indicators of the two groups were compared. Measurement data were expressed as mean±standard deviation ( Mean± SD), comparison between groups was by t-test; count data comparison between groups was by Chi-square test. Logistic regression analysis was used to screen out the influencing factors of graft stenosis after CABG. Use the rms package in the R 4.0.2 software to build a nomogram prediction model. Using receiver operating characteristic (ROC) curve to evaluate the discriminative degree of the model. Use the calibration curve and deviation correction C-index to evaluate the nomogram prediction model. Use X-tile software to obtain the cutoff value of the nomogram model integral, use Kaplan-Meier method to draw the survival curve, and use Log-rank to test. Results:Logistic regression analysis showed that smoking, hypertension, pre-CABG left anterior descending branch (LAD) stenosis <75%, pre-CABG left internal mammary artery (LIMA) blood flow, and coronary angiography diffuse lesions are independent risk factors that affect LIMA-LAD graft stenosis after CABG ( P<0.05). The C-index value predicted by the nomogram model was 0.879 (95% CI: 0.818-0.955, P<0.001). The area under the ROC curve was 0.712 (95% CI: 0.594-0.801, P<0.001), with good discrimination. The calibration curve shows that the accuracy of the model prediction was good. Through the X-tile software screening to obtain the model score cutoff value, the patients were divided into low-risk group (≤54 points), medium-risk group (>54 points and ≤112 points), and high-risk group (>112 points). The results of survival analysis showed that the incidence of postoperative graft stenosis in the three groups was 20.9%, 50.0% and 80.0%, respectively. Conclusions:Smoking, hypertension, LAD stenosis before CABG <75%, LIMA blood flow before CABG, and coronary angiography diffuse lessions are independent risk factors that affect LIMA-LAD graft stenosis after CABG. The construction of a nomogram prediction model can provide a reference for evaluating the patency of the LIMA-LAD graft vessel before CABG operation, and reduce the probability of LIMA-LAD graft vessel stenosis after CABG operation.

Transesophageal echocardiography estimation of coronary sinus blood flow for the adequacy of revascularization in patients undergoing off-pump coronary artery bypass graft.

Aims and Objectives: Physiologically coronary sinus (CS) drains the left coronary artery (LCA) territory. Stenosis of the branches of LCA may decrease the coronary sinus blood flow (CSBF). Any intervention that aims at restoring the flow of the stenosed vessel increases coronary artery flow that should consequently increase the CSBF. Hence, this study was undertaken to assess the CSBF before and after each branch of LCA to determine the adequacy of surgical revascularization in patients undergoing elective off pump coronary artery bypass grafting (OPCAB) using transesophageal echocardiography (TEE). Materials and Methods: Thirty consecutive patients scheduled for elective OPCAB were enrolled. CSBF was assessed before and after each branch of LCA revascularization using TEE. Left internal mammary artery (LIMA) Doppler was also obtained post LIMA to left anterior descending (LAD) grafting. Results: Hemodynamic and echocardiographic variables were compared by means of Student’s t-test for paired data before and after revascularization. The CSBF per beat (1.28 ± 0.71), CSBF per minute (92.59 ± 59.32) and total velocity time integral (VTI) (8.93 ± 4.29) before LAD grafting showed statistically significant increase to CSBF per beat (1.70 ± 0.89), CSBF per minute (130.72 ± 74.22) and total VTI (11.96 ± 5.68) after LAD revascularization. The CSBF per beat (1.67 ± 1.03), CSBF per minute (131.91 ± 86.59) and total VTI (11.00 ± 5.53) before obtuse marginal (OM) grafting showed statistically significant increase to CSBF per beat (1.91 ± 1.03), CSBF per min (155.20 ± 88.70) and total VTI (12.09 ± 5.43) after OM revascularization. In 9 patients, color flow Doppler of LIMA could be demonstrated which showed diastolic predominant blood flow after LIMA to LAD grafting. Conclusion: Demonstration of CSBF was simple and monitoring the trend of CSBF values before and after each graft of LCA territory will guide to determine the adequacy of surgical revascularization.

Comparison of left internal mammary artery diameter before and after left stellate ganglion block.

Aims and Objectives: Left internal mammary artery (LIMA) is the preferred arterial conduit for coronary artery bypass grafting. Various pharmacological agents are known to increase LIMA blood flow. Sympathetic blockade mediated by stellate ganglion block (SGB) has been used to provide vasodilatation in the upper extremities and in the treatment of refractory angina. We investigated effect of left stellate ganglion block (LSGB) on LIMA diameter. Materials and Methods: In 30 diagnosed patients of triple vessel coronary artery disease, LSGB was given under fluoroscopic guidance by C6 transverse process approach using 10 ml of 1% lignocaine. LIMA diameter was measured before and 20 min after the block at 2nd, 3rd, 4th and at 5th rib level. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were recorded before and 20 min after the block. Results: The LIMA diameter increased significantly at 2nd (2.56 ± 0.39 vs. 2.99 ± 0.40; P < 0.0001), 3rd (2.46 ± 0.38 vs. 2.90 ± 0.40; P < 0.0001), 4th (2.39 ± 0.38 vs. 2.84 ± 0.41; P < 0.0001) and 5th rib level (2.35 ± 0.38 vs. 2.78 ± 0.40; P < 0.0001). No statistically significant change occurred in HR, SBP, DBP and MAP before and 20 min after LSGB. Conclusions: LSGB significantly increased the LIMA diameter. The LSGB can be considered as an alternative to topical and systemic vasodilators for reducing vasospasm of LIMA.

A successful team treatment for left main shock syndrome / 老年心脏病学杂志（英文版）

Acute myocardial infarction complicated by cardiogenic shock and left main coronary artery disease is called left main shock syndrome. It is reported that the morbility and mortality of the syndrome is approximately 0.46%and 55%-80%, respectively. However, the best treat-ment strategy in these cases is unknown. In this article, we present a patient with LMSS who successively underwent emergency percutane-ous coronary intervention and coronary artery bypass grafting with hemodynamic support within 5 days. The patient is now on his three month uneventful out-patient follow-up.