Impact of Radial Artery Graft Anastomosis Strategies on Flow Characteristics and Early Patency in Coronary Artery Bypass Grafting / 中国循环杂志

Objectives:The aim of this study was to assess the influence of graft anastomosis strategies of radial artery on the flow characteristics and early patency in coronary artery bypass grafting(CABG). Methods:Present study enrolled 99 patients(92 males,7 females,aged[57.2±8.7]years),who underwent isolated CABG using a radial artery(RA)graft from January 2019 to December 2021 in our department.The RA was proximally anastomosed to the aorta in 79 patients(group 1)and to another graft as a composite graft in 20 patients(group 2).The intraoperative flow characteristics were evaluated with the transit time flow measurement(TTFM),and the graft patency was assessed by computed tomography coronary angiograms perioperatively and at 1year after operation respectively. Results:Baseline characteristics were similar between the two groups(all P＞0.05).There was no perioperative death.Incidence of minimally invasive cardiac surgery for CABG(MICS CABG)and mean flow(MF)of RA grafts were both higher in group 2 than in group 1(all P＜0.05).Perioperative RA graft failure rate was 24.2%(n=24),which tended to be lower in group 2 than in group 1(10.0%vs.27.8%,P=0.096).CT angiography showed that RA graft failure reduced to 16.1%at one year after operation.Compared to patency group,patients with failure RA grafts perioperatively had higher pulse index(PI)and lower intraoperative MF(all P＜0.05).Patients with failure RA grafts at one year after operation had higher PI and more bypassed to the right coronary artery(RCA)target territories of RA grafts(all P＜0.05). Conclusions:RA proximal anastomosis to the aorta or to another graft dose not affect the perioperative patency in CABG.Some RA graft that failed perioperatively might recanalize at one year after operation.High intraoperative PI and bypassed to RCA of RA grafts may be predictors of graft failure at one year after operation.

Graft flow analysis of application of bilateral internal mammary artery with different configurations in coronary artery bypass grafting / 中华胸心血管外科杂志

Objective:To analyze the influence of application of bilateral internal mammary artery(BIMA) with different configurations in coronary artery bypass grafting(CABG).Methods:From January 2018 to December 2020, 82 patients underwent CABG using BIMA were included, with 75 males and 7 females, aged(56.9±9.8) years old. According to the target of coronary artery of BIMA, patients were divided into two groups, 23 patients(group B) who underwent the traditional operation(RIMA to the right coronary artery), and 59 patients(group L) whose RIMA were grafted to the left ventricular arteries. Also the patients were divided into two groups according to the RIMA used either in situ(group I, 57 cases) or free(group F, 25 cases). Compare the grafts flow between groups. The CTA angiography of coronary artery was completed to evaluate the grafts patency before discharge.Results:There was 1 early operative death(1.22%). The mean flow(MF) of RIMA was significantly higher in group B( P=0.013). The pulsatility index(PI) of LIMA was significantly lower and the MF of RIMA and BIMA was higher(all P<0.05), fewer patients with LIMA-MF less than 15 ml/min( P=0.023)in the group I. CTA angiography before discharge showed that only 1 RIMA to right coronary artery was occlusion. Conclusion:It is better to use BIMA in situ in CABG, RIMA used in right coronary artery can receive more satisfactory graft flow. BIMA has good patency in early stage, therefore is the ideal and stable coronary bypass graft.

The implication of anastomotic port exploration and dredging in coronary artery bypass grafting / 中国胸心血管外科临床杂志

@#Objective    To evaluate the changes of the flow parameters before and after the anastomotic port exploration and dredging during coronary artery bypass grafting by using the transit time flow measurement (TTFM). Methods    A total of 167 patients who underwent continuous coronary artery bypass grafting and anastomotic port exploration and dredging surgery in Beijing Anzhen Hospital from 2018 to 2019 were enrolled in this study. There were 136 male and 31 female patients aged 41-82 (58.35±17.26) years. If the probe entered and exited the anastomotic port smoothly, it was recorded as a non-resistance group; if the resistance existed but the probe could pass and exit, it was recorded as a resistance group; if the probe could not pass the anastomotic port for obvious resistance, it was recorded as the stenosis group. In the stenosis group, the grafts were re-anastomosed and the flow parameters were re-measured by TTFM. Results    A total of 202 anastomotic ports were carried out by exploration and dredging. Among them, 87 anastomosis (43.1%) were in the non-resistance group, and there was no significant change in the blood flow volume (BFV) and pulsatility index (PI) before and after exploration and dredging (6.16±3.41 mL/min vs. 6.18±3.44 mL/min,  P=0.90; 7.06±2.84 vs. 6.96±2.49, P=0.50). Sixty-four anastomosis (31.7%) were in the resistance group, the BFV was higher after exploration and dredging than that before exploration and dredging (17.11±7.52 mL/min vs. 4.96±3.32 mL/min, P<0.01), while the PI was significantly smaller (3.78±2.20 vs. 8.58±2.97, P<0.01). Fifty-one anastomosis (25.2%) were in the stenosis group, and there was no significant change in the BFV and PI before and after exploration and dredging (3.44± 1.95 mL/min vs. 3.48±2.11 mL/min, P=0.84; 10.74±4.12 vs. 10.54±4.11, P=0.36). After re-anastomosis, the BFV was higher (16.48±7.67 mL/min, P<0.01) and the PI deceased (3.43±1.39, P<0.01) than that before exploration and dredging. Conclusion    The application of anastomotic exploration and dredging can reduce the occurrence of re-anastomosis, and promptly find and solve the stenosis of the distal coronary artery, improve the poor perfusion of distal coronary, and thus improves the prognosis of patients.

Effect of Yijing Buyang Huanwu Decoction on intraocular pressure and prognosis of open angle glaucoma / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To study the effect of Yijing Buyang Huanwu Decoction on intraocular pressure control and prognosis in patients with open angle glaucoma. <p>METHODS: Totally 93 patients(186 eyes)with open angle glaucoma admitted to our hospital from July 2015 to July 2017 were selected. All patients were divided into two groups according to the random number table method. In the observation group, 47 cases(94 eyes)were treated with timolol eye drop combined with Yijing Buyang Huanwu Decoction, and in the control group, 46 cases(92 eyes)were treated with timolol eye drop only. The clinical effect, visual acuity, intraocular pressure, central retinal artery blood flow, mean defect area, visual field average photosensitivity and image evoked visual potential were observed and compared before and after treatment. <p>RESULTS: The total effective rate of the observation group after treatment was significantly higher than that of the control group(85.1% <i>vs</i> 63.0%, <i>P</i><0.01). After treatment, the intraocular pressure in the observation group was significantly lower than that in the control group(<i>P</i><0.01). After treatment, RI values of central retinal artery blood flow in observation group were significantly lower than those in control group(<i>P</i><0.01). PSA and EDV values were significantly higher than those in control group(<i>P</i>=0.011,<0.01). After treatment, the average photosensitivity of the observation group was significantly higher than that of the control group(<i>P</i>=0.001), and the average defect area was significantly less than that of the control group(<i>P</i>=0.011). <p>CONCLUSION: Yijing Buyang Huanwu Decoction is effective in the treatment of open angle glaucoma. It can effectively control the level of intraocular pressure, enlarge the visual field, promote blood circulation and improve the prognosis.

Grafts patency prediction of Transit-Time Flow Measurement for CABG postoperative one-year / 中华胸心血管外科杂志

Objective To study the value of parameters of Transit-Time Flow Measurement(TTFM) as predictor and judge for one-year after coronary artery bypass transplantation in patency rate of vessel grafts .Methods Parameters of quantity of blood flow and the value of PI( pulsation index) were measured and recorded by intraoperative TTFM in CABG .One-year of follow-ing up, coronary artery CT or coronary angiography examination were accomplished.Results Our study include artery grafts 46(including LIMA grafts 44, RIMA graft 1 and radial artery graft 1) with the patency rate of grafts 91.3％ for one-year after CABG, and vein grafts 48 with the patency rate of grafts 66.7％ .There exists statistically significant difference between above two groups(P<0.001).High PI is independent risk factor(P =0.037) in patency rate of vessel grafts for one-year after CABG by binary logistics regression analysis but no other parameters have the statistical significance (P>0.05) .The results from logistic regression were summarized using the area under the ROC curve(AUC) .The pulsation index has been found hav-ing moderate judgment ability(P=0.016) for the dysfunction of grafts after CABG for one-year with optimal cut-off value of 2. 45.Conclusion Intraoperative high value of PI is the independent risk factor in patency rate of vessel grafts for one-year after CABG.

Medición in vitro del flujo con Doppler en diferentes condiciones mecánicas y su comparación con el real / Measuring in vitro Doppler flow at different mechanical conditions and compared with the real

Objective: to compare Doppler measurements with real flow in a in-vitro model, with variable diameters and insonation angle. Methods: The silicone tubes were 3-8 mm width, and set with variable inclinations from 40° to 70°. Two pumps with constant flow were used for all combinations of diameters and angles. A Sonoace 8000 from Medison was used. Real flow was compared to measured flow. Results: The measured flows varied importantly in different conditions. In a 3 mm tube, estimated flow increased from 212 ml/min to 403 ml/min when the angle was increased from 40° to 70°, when real flow was 140 ml. As well, in 8 mm tubes, estimated flow increased from 651 ml/min to 1.080 ml/min when the angle was increased from 40° to 70°, when real flow was 360 ml/min. Measured flows were 1.6 times greater than real flow. Conclusion: Measured flows were greater than real, with greater increase in larger tubes and greater angles. This confirms that velocity measurements need lowest angles possible. Measured flows are only representations of real flow, but can be considered useful as they were reproducible.

Objetivos: Recientes aplicaciones del Doppler pulsado se han orientado hacia la medición del flujo (ml/s) de la vena umbilical fetal, sin embargo sus mediciones han tenido cuestionamientos desde el punto de vista de la validez, por el efecto del ángulo y el flujo laminar. El objetivo de este estudio es probar la validez de las mediciones ecográficas en un modelo in vitro. Métodos: Se construyó un sistema dentro de un reservorio de agua, en que se instalaron tubos de silicona variando el lumen (3-8 mm), inclinación del tubo (40°-70°) y dos velocidades de infusión de agua. Se instaló la sonda convexa del transductor transabdominal a 5 cm sobre el tubo, de modo que todo el trayecto del tubo sea visualizado en la pantalla del ecógrafo SONOACE 8000 de Medison. Se corrigió el ángulo con la función del ecógrafo. El flujo se estimó por ecografía al multiplicar la velocidad medida por Doppler pulsado por el área interna del tubo. Se comparó el flujo medido real, obtenido por el volumen de agua obtenida en un minuto de funcionamiento de la bomba, y el medido por ecografía Doppler. El flujo medido por Doppler se obtuvo 2 veces, para comparar la variación intrínseca del método y verificar su confiabilidad. Resultados: Los flujos obtenidos variaron según las condiciones mecánicas importantemente. En tubos de 3 mm de diámetro, con ángulos crecientes de 40° a 70°, los fl ujos estimados aumentaron de 212 ml/min a 403 ml/min cuando el flujo real era de 140 ml/min. A su vez, en tubos de 8 mm, con ángulos crecientes de 40° a 70°, los flujos estimados aumentaron de 651 ml/min a 1.080 ml/min, cuando el flujo real era de 360 ml/min. Se demostró una correlación lineal entre el flujo estimado y el real de: Qestimado=(Qreal x 1,63)+181, r= 0,84. La aplicación del test de Bland y Altman demostró que las mediciones son repetibles y consistentes. Conclusión: Los flujos medidos en ecografía fueron 1,6 veces más que los obtenidos en flujo real en las condiciones mecánicas...

Simple procedure for evaluation of the frequency response of flow transducers used in spirometry / Procedimento simples para avaliação da resposta em frequência de transdutores de vazão usados em espirometria

In this research, we present a simple mechanical assembly for evaluation of frequency response of flow transducers. Also, two pneumotachometer/pressure transducer (PPT) ensembles were evaluated with this setup. The accuracy of the measurements depended mainly on the physical dimensions of a piston, without need for a closed-loop control for the generated flow, which would demand a pre-calibrated electronic pressure transducer or an optical position detection device. The gain and phase curves found for both evaluatedPPTs are presented. We conclude that the presented mechanism is suitable to evaluate the dynamic response of these PPTs in the range between 1.0 and 50.0  Hz. Regarding the evaluated PPTs, we concluded that the gain curves in the whole dynamic range of both assemblies were 0 and +2.63  dB for PPT assembly 1, and 0 and +6.70  dB for PPT assembly 2.

Este trabalho apresenta um sistema mecânico simples para levantamentoda resposta em freqüência de transdutores de vazão de gás. Dois conjuntos de pneumotacômetro/transdutor de pressão (PPT) foram avaliados com este sistema. A exatidão das medidas dependeu principalmente das dimensões de um pistão, sem a necessidade de controle com malha fechada da vazão gerada, o que demandaria o uso de um transdutor de pressão eletrônico pré-calibrado ou um dispositivo óptico para detecção de posição. As curvas de ganho e defasagem dos dois conjuntos PPT avaliados são apresentadas. É possível concluir que o mecanismo apresentado é capaz de avaliar a resposta dinâmica destes PPTs na faixa de 1,0 a 50,0  Hz. Em relação à avaliação dos PPTs, concluiu-se que as curvas de ganho em toda a faixa dinâmica avaliada em ambos PPTs ficaram entre 0 e +2,63  dB para o conjunto PPT 1 e entre 0 e +6,70  dB para o conjunto PPT 2.

Algorithms to calculate the AQD distribution with exponential Kernel for ultrasonic doppler blood flow measurement

One of the main goals in ultrasonic Doppler blood flow assessment in the estimation of the mean speed. The aim of this work is focused in Carotid artery blood flow signals...

Transit time flow measurement in coronary surgery / 中华胸心血管外科杂志

Objective: To review the experience of using the transit time flow measurement(TTFM) in coronary artery bypass grafting(CABG). Methods: From Sept.2001 to May, 2002,90 cases underwent CABG. Among them, 40 cases with off-pump beating heart (OPCAB) and 50 with conventional coronary bypass grafting. All graft patency were verified intraoperatinlly with TTFM. The flow value of left internal mammary artery (LIMA) in 30 cases was also detected by the same way before grafting to left anterior descending (LAD). Results: There was no operative death and severe complications. The mean flow value of LIMA in 30 cases was (42.9?33.0)ml/min. The actual blood flow value, measured simultaneously by exsanguination was (37.4?28.8)ml/min. Excellent correlation was demonstrated. The mean pulsatility index value (PI) was 1.00?0.04. The flow curve showed both diastolic and systolic filling. The mean flow value of LIMA to LAD, saphenous vein graft (SVG) or radial artery (RA) to circumflex coronary artery (LCX) or diagonal (D), SVG or RA to right coronary artery (RCA) or post anterior artery (PDA) were (29.9?9.5)ml/min, (33.7?17.5)ml/min and (31.5?19.2)ml/min. The PI values were 2.47?0.88, 4.00?1.90 and 2.60?1.30, respectively. The typical flow curve was shown in all LIMA to LAD, and SVG (or RA) to LCX (or D). Blood flow filling was mainly during diastole with minimal systolic peaks during the isovolumetric ventricular contraction. SVG or RA to RCA presents a particular flow pattern characterized by a dual filling. 6 grafts were revised basing on unsatisfied flow curves, PI, and the mean flow or all of them. Significant technical error such as conduit kinking, stenosis of distal anastomosis was found. Conclusion: The patency of graft in CABG can be verified in intraoperatively by use of TTFM. The decision of checking or revising a graft can be made basing on parameters acquired from the TTFM device. To correctly analyze the parameters warrants good clinical results.

Analysis on Graft Blood Flow After Off-Pump Coronary Artery Bypass Grafting in Patients over 60 Years / 中国微创外科杂志

0.05). However, we found that the proportions of low Qm (5) in the patients over 60 years were significantly higher than those in the patients younger than 60. [For low Qm, IMA: 13% (10/75) vs 2% (1/46), and GSV: 13% (33/259) vs 6% (7/123), ?2=4.296 and 4.422, P