The use of AVF.SIM system for the surgical planning of arteriovenous fistulae in routine clinical practice

2022 ◽  
pp. 112972982110626
Author(s):  
Michela Bozzetto ◽  
Sofia Poloni ◽  
Anna Caroli ◽  
Diego Curtò ◽  
Annick D’Haeninck ◽  
...  
Keyword(s):  
Blood Flow ◽  
Clinical Outcome ◽  
Surgical Planning ◽  
Clinical Investigation ◽  
Primary Patency ◽  
Cardiac Complications ◽  
Flow Volume ◽  
Blood Flow Volume ◽  
Number Of Patients ◽  
First Choice

Background: The number of patients treated with hemodialysis (HD) in Europe is more than half a million and this number increases annually. The arteriovenous fistula (AVF) is the vascular access (VA) of first choice, but the clinical outcome is still poor. A consistent number of AVFs fails to reach the desired blood flow rate for HD treatment, while some have too high flow and risk for cardiac complications. Despite the skill of the surgeons and the possibility to use Ultrasound investigation for mapping arm vasculature, it is still not possible to predict the blood flow volume that will be obtained after AVF maturation. Methods: We evaluated the potential of using a computational model (AVF.SIM) to predict the blood flow volume that will be achieved after AVF maturation, within a multicenter international clinical investigation aimed at assessing AVF.SIM predictive power. The study population included 231 patients, with data on AVF maturation in 124 patients, and on long-term primary patency in 180 patients. Results: At 1 year of follow-up, about 60% of AVFs were still patent, with comparable primary patency in proximal and distal anastomosis. The correlation between predicted and measured blood flow volume in the brachial artery at 40 days after surgery was statistically significant, with an overall correlation coefficient of 0.58 ( p < 0.001). The percent difference between measured and predicted brachial blood flow 40 days after surgery was less than 30% in 72% of patients investigated. Conclusions: The results indicate that the use of the AVF.SIM system allowed to predict with a good accuracy the blood flow volume achievable after VA maturation, for a given location and type of anastomosis. This information may help in AVF surgical planning, reducing the AVFs with too low or too high blood flow, thus improving AVF patency rate and clinical outcome of renal replacement therapy.

Analysis of factors for post–percutaneous transluminal angioplasty primary patency rate in hemodialysis vascular access

2020 ◽  
Vol 21 (6) ◽  
pp. 892-899
Author(s):  
Kanyu Miyamoto ◽  
Takashi Sato ◽  
Keisuke Momohara ◽  
Sumihisa Ono ◽  
Makoto Yamaguchi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Confidence Interval ◽  
Arteriovenous Fistula ◽  
Percutaneous Transluminal Angioplasty ◽  
Transluminal Angioplasty ◽  
Primary Patency ◽  
Hazard Ratio ◽  
Flow Volume ◽  
Blood Flow Volume ◽  
Percutaneous Transluminal

Background: Although percutaneous transluminal angioplasty has been established as a first-line therapy for access failure in dialysis, there are few reports on primary patency after percutaneous transluminal angioplasty. We investigated factors associated with primary patency following the first percutaneous transluminal angioplasty performed after vascular access construction in patients with arteriovenous fistula, including blood flow volume before and after percutaneous transluminal angioplasty and previously reported factors. Methods: We used medical records at six dialysis centers to retrospectively identify and analyze prognostic factors for primary patency after percutaneous transluminal angioplasty in 159 patients with arteriovenous fistula who underwent initial percutaneous transluminal angioplasty after vascular access construction. Results: Multivariate analysis with the Cox proportional hazard model showed that primary patency after percutaneous transluminal angioplasty in patients with arteriovenous fistula was significantly associated with lesion length (hazard ratio, 1.76; 95% confidence interval, 1.01–3.07; P = 0.045), and blood flow volume after percutaneous transluminal angioplasty (hazard ratio, 0.71; 95% confidence interval, 0.60–0.84; P < 0.001). When blood flow volume after percutaneous transluminal angioplasty was classified into three categories, risks of outcome events defining the end of primary patency after percutaneous transluminal angioplasty were significantly lower for 400–630 mL/min (hazard ratio, 0.38; 95% confidence interval, 0.21–0.68; P = 0.001) and >630 mL/min (hazard ratio, 0.16; 95% confidence interval, 0.06–0.40; P < 0.001) compared with <400 mL/min. Conclusion: Our study showed that blood flow volume after percutaneous transluminal angioplasty is an important prognostic factor for primary patency after percutaneous transluminal angioplasty in patients with arteriovenous fistula.

scholarly journals P07.04: Uterine artery blood flow volume is reduced in human pregnancies with increase utero-placental downstream impedance

2006 ◽  
Vol 28 (4) ◽  
pp. 569-569
Author(s):  
S. Boito ◽  
S. Rigano ◽  
G. Pennati ◽  
L. Mandia ◽  
A. Padoan ◽  
...  
Keyword(s):  
Blood Flow ◽  
Uterine Artery ◽  
Flow Volume ◽  
Artery Blood Flow ◽  
Blood Flow Volume

Cerebral Blood Flow Volume in Posterior Circulation Ischemic Disorders

2021 ◽  
pp. 154431672110539
Author(s):  
Anastasiya Yu. Vishnyakova ◽  
Nataliya M. Medvedeva ◽  
Alexander B. Berdalin ◽  
Svetlana E. Lelyuk ◽  
Vladimir G. Lelyuk
Keyword(s):  
Blood Flow ◽  
Healthy Volunteers ◽  
Internal Carotid ◽  
Duplex Sonography ◽  
Posterior Circulation ◽  
Control Group ◽  
Vertebrobasilar Insufficiency ◽  
Flow Volume ◽  
Blood Flow Volume ◽  
Vertebral Arteries

Objective: The aim of this study was to determine blood flow volume (BFV) in the normal state and its features in patients with acute posterior circulation ischemic strokes (PCIS) and vertebrobasilar insufficiency (VBI) using color duplex sonography (DS).Methods: The study included DS data from 96 patients with verified PCIS (66 men and 30 women, aged 64±13 years) and 29 adults with VBI (17 men and 12 women, aged 66±11 years). The control group consisted of 65 healthy male volunteers of different ages.Results: In asymptomatic healthy volunteers, there was a significant decrease in BFV in the internal carotid artery (ICA) with age (502 ml/min in young people, 465 ml/min in the older subgroup) with rS = −0.24 ( p = 0.05), and the aggregated BFV in the vertebral arteries (VAs) turned out to be almost constant (141–143 ml/min). In patients with VBI, the aggregated BFV in the VAs (144 ml/min) did not differ from that in healthy volunteers, but the BFV values in the ICAs were significantly lower (325 ml/min). In patients with PCIS, the aggregated BFV in the ICAs was also significantly lower (399 ml/min) than in the control group but did not significantly differ from that in patients with VBI. In patients with PCIS, there was a significant decrease in the aggregated BFV in the VAs (105 ml/min), which distinguished this group from other examined patients.Conclusions: A significant decrease the BFV in the VA was observed only in patients with PCIS and was associated with the presence of steno-occlusive diseases (SOD) more often in the left VA. Patients with VBI had the most pronounced decrease in BFV in the ICA.

Blood flow, volume, and transit time in the pulmonary microvasculature using laser-Doppler

1994 ◽  
Vol 76 (6) ◽  
pp. 2643-2650 ◽  
Author(s):  
T. S. Hakim ◽  
E. Gilbert ◽  
E. M. Camporesi
Keyword(s):  
Blood Flow ◽  
Blood Volume ◽  
Transit Time ◽  
Flow Rate ◽  
Venous Pressure ◽  
Laser Doppler ◽  
Flow Volume ◽  
Doppler Flowmetry ◽  
Blood Flow Volume ◽  
Wide Range

Capillary transit time is determined by the ratio of capillary volume to flow rate. Exercise-induced hypoxemia is thought to occur because of the short transit time of erythrocytes in capillaries. The effect of flow rate on capillary volume (recruitment vs. distension) is controversial. In a perfused left lower lobe preparation in canine lungs, we used laser-Doppler flowmetry (model ALF21R) to monitor changes in blood flow, volume, and transit time in the microvasculature near the subpleural surface. Changes in total flow, blood volume, and total transit time (tt) were also measured. The results showed that microvascular volume approached maximum when flow rate was at resting value (0.4 l/min) and pressure in the pulmonary artery was > 6 mmHg relative to the level of the capillaries. In contrast, the total blood volume increased gradually over a wide range of flow rates. When flow increased 4.2 times (from 155 to 650 ml/min), tt decreased from 7.32 to 3.53 s; meanwhile, microvascular flow increased from 6.0 to 12.7 units and microvascular transit time decreased from 3.14 to 1.81 units. The changes in microvascular volume and transit time were essentially independent of whether the venous pressure was higher or lower than alveolar pressure. At very high flow (6–10 times resting value), tt fell gradually to approximately 1 s. Direct monitoring of transit time with the laser-Doppler also revealed a gradual decline in microvascular transit time as flow rate increased from 2 to 10 times the normal flow. (ABSTRACT TRUNCATED AT 250 WORDS)

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