Objective To establish a close clinical and easy to operate animal artery bypass grafting model by using vascular anastomosis wheel.Methods 15 rabbits that weighted 2.5-3.5 kg were studied.Each animal underwent an end-toend anastomosis of jugular vein and carotid artery by vascular anastomosis wheel.Carotid ultrasound and flow detection were taken immediately and 2 months after surgery respectively,as well as morphology and pathology were recorded to analyze and evaluate the intimal hyperplasia of vein graft and arteriovenous anastomotic site.Results 14 rabbits were successfully established CABG model,however 1 rabbit died of respiratory inhibition caused of excessive anesthesia.Compared with normal carotid artery,the vein bridge showed significantly lower blood flow [(50.81 ± 1.33) ml/min vs.(70.59 ± 0.68) ml/min,P ＜0.01,higher PI(2.15 ±0.07vs.1.22 ±0.04,P ＜0.01)] immediately after surgery.Compared with the vein grafts immediately after surgery,the vein grafts 2 months after surgery showed significantly lower blood flow [(27.46 ± 2.15) ml/min vs.(50.81 ± 1.33) ml/min,P ＜ 0.01].Compared with normal jugular vein,the vein grafts 2 months after surgery showed significantly higher intimal hyperplasia[(160.30 ± 1.78) μm vs.(49.06 ± 2.76) μm,P ＜ 0.01],and higher number of elastic plates(12.36 ± 0.25vs.3.21 ± 0.15,P ＜ 0.01).Conclusion The use of vascular anastomosis wheel to establish an artery bypass graft model can imitate the pathological changes of vein grafts after CABG,which can provide an ideal animal model for various researches on vein grafts.

Objective To evaluate the efficacy and clinical significance of medical chemical glue as an external stent in improving the fluency rate of venous bypass graft after coronary artery bypass grafting .Methods Randomly selected 200 pa-tients from April 2010 to December 2016 included who were underwent coronary artery bypass grafting in Beijing Anzhen Hospi-tal.All patients had different degrees of angina , and coronary angiography showed multi-branches artery lesion.They were ran-domly divided into two groups, 100 in each group.Spray gel group: coronary artery bypass grafting simultaneously spraying medical chemical glue on the surface of the bridge vessel.Unsprayed gel group:simple coronary artery bypass grafting.All 200 patients were followed up in June 2018.The follow-up content mainly included: recent recurrence of angina pectoris, recent echocardiography and electrocardiogram report, coronary CTA or coronary angiography results, and current living conditions. The data obtained were collectively summarized and compared .Results The follow-up rate was 96％ in the sprayed group, and 92％ in the unsprayed group.Compared with the unsprayed group , the incidence of chest pain and angina pectoris was significantly lower in the sprayed group(23.96％ vs.40.22％, P<0.05), the venous occlusion rate of the vein bypass graft in the sprayed group was significantly lower(29.17％ vs.55.43％, P<0.01), the probability of death due to cardiac causes in the sprayed group was significant decrease(1.04％ vs.6.52％, P<0.05), the number of patients with the main adverse cardiac and cerebral events(MACCE) in the sprayed group was significantly lower(9.38％ vs.21.74％, P<0.01), all with statistically significant differences .The number of patients with heart failure and recurrent myocardial infarction was lower in the sprayed group, but there were no statistically significant differences .Conclusion Medical chemical glue as an external stent does play a role in improving the venous patency rate after coronary artery bypass grafting , and it is reliable for the preven-tion and treatment of vein bypass vascular stenosis after coronary artery bypass grafting .

Objective:To compare the efficacy of Milrinone and Papaverine in relieving the spasm of internal mammary artery (LIMA) during off-pump coronary artery bypass grafting (OPCABG).Methods:Between April 2018 to December 2018, 200 patients who suffered obvious angina pectoris and three-vessel disease documented by coronary angiography, undergoing OPCABG at Beijing Anzhen Hospital, Capital Medical University were recruited in this study, including 103 males and 97 females, aged 46-74 years, with an average of (59.12±0.49) years old. For all patients, the LIMA was anastomosed to left anterior descending artery(LAD). According to different methods relieving LIMA spasm, all patients randomly divided into 4 groups (n=50): Papaverine surface infiltration group (group Ⅰ), Papaverine injection group (group Ⅱ), Milrinone surface infiltration group (group Ⅲ) and Milrinone injection group (group Ⅳ). The blood flow (ml/min) of the free LIMA, the blood flow of the LIMA-LAD after bypass, anastomotic time of obtuse marginal artery, the use of vasoactive drugs, the outcomes of perioperative period and 1 year after operation were compared in the four groups.Results:There was no significant difference between group Ⅲ and group Ⅰ in the blood flow of free LIMA and LIMA-LAD[(45.50±1.43)ml/min vs. (47.42±1.61)ml/min、(28.60±0.89)ml/min vs. (28.40±0.96)ml/min, all P>0.05]. The blood flow of free LIMA and the LIMA-LAD in group Ⅱ were significantly higher than those in group Ⅰ[(60.36±1.28)ml/min vs. (47.42±1.61)ml/min, (42.40±1.25)ml/min vs. (28.40±0.96)ml/min, all P<0.05]. The blood flow of free LIMA and LIMA-LAD in group Ⅳ were significantly higher than those in group Ⅲ[(70.86±2.00) ml/min vs. (45.50±1.43) ml/min, (59.46±1.25) ml/min vs. (28.60±0.89) ml/min, all P<0.05]. The blood flow of free LIMA and LIMA-LAD in group Ⅳ were significantly higher than those in group Ⅱ[(70.86±2.00) ml/min vs. (60.36±1.28) ml/min, (59.46±1.25) ml/min vs. (42.40±1.25)ml/min, all P<0.05]. The anastomotic time of obtuse marginal artery[(7.14±0.72)min vs. (8.30±0.93)min, (8.10±0.89)min, (8.14±0.90)min, P<0.05], the dopamine dose[(3.76±0.40)μg·kg -1·min -1 vs. (5.02±0.52)μg·kg -1·min -1, (4.84±0.48)μg·kg -1·min -1, (4.90±0.49)μg·kg -1·min -1,P<0.05] and the esmolol usage (32% vs. 60%, 58%, 58%, P<0.05) during the operation in group Ⅳ were significantly reduced compared with the other three groups. The V3 ST depression on the postoperative first day[(0.34±0.18)mv vs. (0.71±0.22)mv, (0.68±0.20)mv, (0.69±0.22) mv, P<0.05], and the TNI on the postoperative third day[(0.24±0.08)ng/ml vs. (0.56±0.15)ng/ml, (0.54±0.11)ng/ml, (0.53±0.12) ng/ml, P<0.05] were significantly lower in group Ⅳ than those in the other three groups. However, there was no significant difference about the first-year patency of LIMA-LAD among four groups. Conclusion:For relieving spasm of LIMA, the Milrinone injection was better than that of Papaverine, which could shorten the anastomotic time of obtuse marginal artery, maintain intraoperative hemodynamics stability, reduce myocardial damage during OPCABG.

Objective:To evaluate the dosimetric characteristics of Zap-X system and CyberKnife (CK) G4 system of stereotactic radiosurgery (SRS) for single brain metastasis.Methods:Twelve patients with single brain metastasis had been treated with CK were selected retrospectively. The prescribed dose of planning target volume (PTV) was 18-24 Gy for 1-3 fractions. The PTV was ranged from 0.44 to 11.52 cm 3. The 12 patients were re-planned in the Zap-X planning system using the same prescription dose and organs at risk constraints, and the prescription dose of PTV was normalized to 70% for both Zap-X and CK. The planning parameters and dosimetric parameters of PTV and organs at risk were compared and evaluated between two plans. All data were read at MIM Maestro. A paired Wilcoxon' signed-rank test was adopted for statistical analysis. A P value of less than 0.05 was considered as statistical significance. Results:For the target coverage, CK was significantly higher than Zap-X (99.14±0.57% vs. 97.55±1.34%, P<0.01), but Zap-X showed a higher conformity index (0.81±0.05 vs. 0.77±0.07, P<0.05), a lower Paddick gradient index (2.98±0.24 vs. 3.15±0.38), and a higher gradient score index (GSI) than CK. The total monitor unit (MU) of Zap-X was significantly lower than that of CK (11 627.63 ±5 039.53 vs. 23 522.16 ±4 542.12, P<0.01) and the treatment time was shorter than that of CK [(25.08 ±6.52) vs. (38.08 ±4.74) min, P<0.01]. Zap-X had lower dose volumes than CK for the dose of brain ( P<0.05). Zap-X had a lower D mean and D max of brainstem (both P<0.05), but a higher value of eyes and lens. For optic nerves and optic chiasm, there were no significant differences between two groups. In addition, for the protection of skin (V 22.5 Gy), Zap-X seemed better than CK [(4.15±4.48) vs. (4.37±4.50) cm 3, P<0.05]. Conclusions:For SRS treating single brain metastasis, Zap-X could provide a high quality plan equivalent to or even better than CK, especially reducing the treatment time. With continuous improvement and upgrading of Zap-X system, it may become a new SRS platform for the treatment of brain metastasis.

Objective:To compare the dosimetric characteristics of beams between Zap-X and G4 CyberKnife and provide reference for clinical application of Zap-X.Methods:PTW three-dimensional water tank and dosimetry diode ionization chamber were used to measure the two orthogonal off-axis ratio and field size at isocenter of 7 different collimators (5 mm, 7.5 mm, 10 mm, 12.5 mm, 15 mm, 20 mm and 25 mm) of Zap-X and CyberKnife at the water depth of maximum dose, 50 mm, 100 mm, and 200 mm. The penumbra, flatness, symmetry and field size under each parameter condition were analyzed by using PTW supporting software PTW MEPHYSTO (version 5.1). Data analysis and graph were performed using Origin 2021 software.Results:With the same collimator, the dose plateau area of Zap-X was wider than that of G4 CyberKnife, and the dose fall-off at the field edge of Zap-X system was faster. With the increase of the collimator, the penumbra of Zap-X and CyberKnife tended to become larger, and the flatness tended to become smaller, the penumbra and flatness of Zap-X were significantly smaller than those of CyberKnife. Both of them had excellent symmetry (<1%), and the symmetry results of CyberKnife (<0.39%) were better than that of Zap-X (0.99%). The accuracy of Zap-X collimator size at isocenter was better than that of CyberKnife.Conclusion:Compared with G4 CyberKnife, Zap-X system has smaller penumbra, better flatness and higher accuracy of collimator size, which is suitable for stereotactic radiosurgery.

Objective To measure the abdominal muscle composition of maintenance dialysis patients using quantitative computed tomography(QCT)and to analyze its relationship with abdominal aortic calcification(AAC).Methods The abdominal CT data of 193 maintenance dialysis patients were analyzed retrospectively and their clinical data were collected.The abdominal muscle composi-tion,including muscle area and muscle fat area,was measured at the middle level of L3 vertebral by QCT.The abdominal aortic calcifica-tion scores(AACs)were calculated using the Agatston method.The groups were grouped according to the quartiles of AACs,and differences in muscle area,muscle fat area and their associated variables were compared between the four groups.The relationship between abdominal muscle composition and AAC was assessed using Spearman rank correlation analysis and partial correlation analysis.Results AACs were positively correlated with age,male,dialysis age,diabetes,hypertension,and abdominal muscle fat area(r=0.555,0.172,0.192,0.348,0.335,0.358,all P<0.05),while no significant correlation was found with abdominal muscle area.A partial correlation analysis controlling for age,sex,dialysis age,hypertension and diabetes showed that AACs were still positively correlated with abdominal muscle fat area(r=0.183,P=0.012).Conclusion Abdominal muscle fat area in maintenance dialysis patients is positively associ-ated with the degree of AAC,and high abdominal muscle fat area is a risk factor for AAC.Enhanced muscle exercise may prevent the risk of vascular calcification in dialysis patients.

Objective    To evaluate the efficacy and clinical significance of bipolar radiofrequency ablation in the treatment of left ventricular aneurysm with ventricular arrhythmias guided by CARTO mapping system. Methods    From September 2009 to December 2015, 56 patients with ventricular aneurysm following myocardial infarction were enrolled. All patients suffered different levels of angina pectoris symptoms evaluated by Holter (the frequencies of ventricular arrhythmias more than 3 000 per day). They were divided into two groups according to random ballot and preoperative communication with patients' family members: a bipolar radiofrequency ablation group (n=28, 20 males, 8 females, mean age of 61.21±1.28 years) receiving off-pump coronary artery bypass grafting (OPCABG), ventricular aneurysm surgery combined with bipolar radiofrequency ablation, and a non-bipolar radiofrequency ablation group (n=28, 22 males, 6 females, mean age of 57.46±1.30 years) receiving OPCABG and single ventricular aneurysm surgery. The grade of cardiac function and ventricular arrhythmia was compared between the two groups during pre-operation, discharge and   follow-up. Results    All patients were discharged successfully. There was no in-hospital death in both two groups. One patient in the non-radiofrequency group had cerebral infarction. All patients were re-checked with Holter before discharge and the frequency of ventricular arrhythmias significantly decreased compared to that of pre-operation in both groups, and was more significant in bipolar radiofrequency ablation group (1 197.00±248.20 times/24 h vs. 1 961.00±232.90 times/24 h, P<0.05). There was significant difference in duration of mechanical ventilation and ICU stay between the two groups (P<0.05). The left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD) significantly improved (P<0.05) after operation in both groups. Conclusion    The clinical efficacy of bipolar radiofrequency ablation in the treatment of ventricular aneurysm with ventricular arrhythmia guided by CARTO mapping is safe and effective, but its long-term outcomes still need further follow-up.

Objective: To evaluate the feasibility and validity of combined directly epicardial and transapical endocardial substrate ablation guided by Carto mapping for ventricular tachycardia(VT) with left ventricular aneurysm(LVA) intra-operation in a swine model. Methods: Twenty-four swine models with sustained VT and LVA were randomly divided into study group(radiofrequency ablation, RFCA, from epicardium via direct-view and endocardium via transapical access, 12 cases) and control group(endocardial RFCA via retrograde transaortic access, 12 cases). Substrate mapping for captured abnormal potentials via endocardium and epicardium was used to precisely locate the low-voltage areas. After ablation in two groups, VT was induced again to compare the effectiveness of different RFCA strategies. Results: Three dimensional electro-anatomic mapping was implemented successfully in two groups under open chest. And VT substrates were largely located in the border zone of LVA. All objects in the study group underwent endocardial ablation via transapical access smoothly without operative failure. When VT inducing again, 2 cases of study group was with inducible VT, however, VT recurrence in control group was 5 cases, P=0.04. Conclusion Combined direct epicardial and transapical endocardial substrate mapping and ablation appeared to be feasible and effective for treating VT with LVA under thoracotomy.