Arterial Stenting and Overdilation: Does it Change Wall Mechanics in Small-Caliber Arteries?

2002 ◽  
Vol 9 (6) ◽  
pp. 855-862 ◽  
Author(s):  
Hélène Vernhet ◽  
Roland Demaria ◽  
Jean-Marie Juan ◽  
Marie-Claire Oliva-Lauraire ◽  
Jean-Paul Senac ◽  
...  

Purpose: To evaluate changes in arterial wall mechanics induced by stent overdilation in the rabbit aorta. Methods: Twenty New Zealand white rabbits had initial stent deployment (3-mm × 8-mm Multilink) at 10% overdilation. Group A (n=11) had no subsequent balloon expansion of the stent and Group B (n=9) had 30% overdilation of the stent. A noninvasive B-mode ultrasound examination coupled with image processing allowed the measurement of systolic and diastolic diameter and the calculation of diameter compliance (Cd) and distensibility coefficient (DC) as indexes of arterial wall biomechanics. Measurements were performed before stenting in the infrarenal aorta, after initial stenting, and after stent overdilation at 3 locations: upstream, at the stent level, and downstream from the stent. Results: Cd was significantly lower in the stented aorta after initial stenting (p<0.0001) and after stent overdilation (p<0.0001) than before stenting. At the stent level, Cd and DC were significantly lower than downstream (p<0.0001) or upstream (p<0.0001) from the stent after initial stenting, as well as after stent overdilation. Downstream from the stent, Cd and DC were significantly lower after stent overdilation than before stenting (p<0.05). Conclusions: Endovascular stenting of the rabbit aorta produces a significant decrease in arterial wall compliance and distensibility. Stent overdilation is responsible for a slight additional decrease of compliance downstream from the stent.

2003 ◽  
Vol 10 (3) ◽  
pp. 577-584 ◽  
Author(s):  
Hélène Vernhet ◽  
Roland Demaria ◽  
Antonia Pérez-Martin ◽  
Jean Marie Juan ◽  
Marie Claire Oliva-Lauraire ◽  
...  

Purpose: To evaluate long-term changes in arterial wall mechanics induced by stenting of the rabbit aorta. Methods: Eighteen New Zealand white rabbits had initial stent deployment (3×8 mm Multilink) at 110% of the pre-stenting abdominal aortic diameter. Group A (n=10) had no post-deployment stent expansion and group B (n=8) had 30% overdilation of the stent. A noninvasive B-mode ultrasound examination coupled with image processing allowed measurement of diameters at systole and diastole and the calculation of diameter compliance. Measurements were performed before stenting and compared to those recorded immediately after stenting and at 3 months at 3 locations: upstream from the stent, at the stent level, and downstream from the stent. Measurements were also compared among measurement sites. The pathological study included measurement of intimal thickening and calculation of an injury score. Results: At the stent level, diameter compliance was significantly lower after initial stenting and at 3 months than before stenting (group A: p<0.005; group B: p<0.001) and than downstream or upstream from the stent (group A: p<0.0001, group B: p<0.005). No significant difference in diameter compliance was found between groups A and B. In group B, intimal thickening and the injury score were greater than in group A (p<0.05 and p<0.0001, respectively). Conclusions: Endovascular stenting of the rabbit aorta impairs wall mechanics. Performing 30% overdilation of the stent does not worsen this impairment but induces greater in-stent intimal hyperplasia.


2011 ◽  
Vol 20 (2) ◽  
pp. 121-126 ◽  
Author(s):  
Fagner Luiz da Costa Freitas ◽  
Beatriz Lie Yamamoto ◽  
Wagner Luiz da Costa Freitas ◽  
Jose Jurandir Fagliari ◽  
Katyane de Sousa Almeida ◽  
...  

Hemograms and acute-phase proteins in adult male New Zealand White rabbits that had been experimentally infected orally with sporulated oocysts of Eimeria stiedai were evaluated over a 28-day period. Fifty animals were used, divided into two groups: group A infected with 1 × 10(4) sporulated oocysts of E. stiedai and group B inoculated with distilled water. On the seventh day after infection, the infected animals presented anemia and leukocytosis with neutrophilia and monocytosis. Protein fractionation by means of electrophoresis identified 19 acute-phase proteins with molecular weights ranging from 24 to 238 kD. Ceruloplasmin, transferrin and haptoglobin showed high levels on the seventh day after infection, with gradual increases in their concentrations until the end of the experimental period. Thus, from the data of the present study, E. stiedai is considered to be a pyogenic etiological agent for which the infection level can be monitored through the leukocyte count and serum concentrations of ceruloplasmin, transferrin and haptoglobin, and these can be recommended as complementary tests.


2021 ◽  
Author(s):  
gan zhang ◽  
Xiaosong Chen ◽  
Xunsheng Cheng ◽  
Xiuwu Ma ◽  
Congcong Chen

Abstract Introduction: The experiment was undertaken to estimate the effect of BMSCs seeding in different scaffold incorporation with HBO on the repair of seawater immersed bone defect. And future compared n-HA/PLGA with β-TCP/PLGA as scaffold in treatment effect of seawater immersed bone defect.Methods: 60 New Zealand White rabbits with standard seawater defect in radius were randomly divided to group A (implant with nothing), group B (implanted with atuogenous bone), group C (implanted with n-HA/PLGA/BMSCs, and Group D ( implanted with β-TCP/PLGA/BMSCs). After implant, each rabbit receive HBO treatment at 2.4 ATA 100% oxygen for 120 minutes per day for 2 weeeks. Radiograph, histological and biomechanical examination were used to analyze osteogenesis.Result: X-ray analysis show that n-HA/PLGA/BMSCs and β-TCP/PLGA/BMSCs could accelerate the new bone formation, and the new bone formation in group C was lager than in group D or group A, and close to group B (P<0.05). After 12 weeks, in group A, defect without scaffold show a loose connect tissue filled in the areas. The medullary canal in group B was recanalizated. Defect in group C and D show a larger number of wove bone formation. The new wove bone formation in defect areas in group C was lager than D. The mechanical examination revealed ultimate strength at 12 weeks were group D>group C>group B>group A(P<0.05).Conclusion: Scaffold of n-HA/PLGA and β-TCP/PLGA incorporation with HBO and BMSCs were effective to treat seawater immersed bone defect, and n-HA/PLGA was more excellent than β-TCP/PLGA.


2020 ◽  
Vol 13 (10) ◽  
pp. 321
Author(s):  
Julian Wolfes ◽  
Christian Ellermann ◽  
Niklas Broer ◽  
Benjamin Rath ◽  
Kevin Willy ◽  
...  

The aim of this study was to investigate the effects of a combination of ranolazine with different selective inhibitors of the Na+/Ca2+-exchanger (NCX) in an established experimental model of atrial fibrillation (AF). Eighteen hearts of New Zealand white rabbits were retrogradely perfused. Atrial catheters were used to record monophasic action potentials (aPRR). Hearts were paced at three different cycle lengths. Thereby, atrial action potential durations (aAPD90), atrial effective refractory periods (aERP) and atrial post-repolarization refractoriness were obtained. Isoproterenol and acetylcholine were employed to increase the occurrence of AF. Thereafter, the hearts were assigned to two groups (n = 9 each group) and additionally perfused with a combination of 10 µM ranolazine and 1 µM of the selective NCX-inhibitor ORM-10103 (group A: Rano-ORM) or 10 µM ranolazine and 1 µM of another NCX-inhibitor, SEA0400 (group B: Rano-SEA). The infusion of Iso/ACh led to a shortening of aAPD90, aERP, aPRR and the occurrence of AF episodes was significantly increased. Additional perfusion with ranolazine and ORM-10103 (group A) significantly prolonged the refractory periods and aPRR and AF episodes were effectively reduced. In group B, Rano-SEA led to a slight decrease in aAPD90 while aERP and aPRR were prolonged. The occurrence of AF episodes was consecutively reduced. To our knowledge, this is the first study investigating the effect of ranolazine combined with different selective NCX-inhibitors in an isolated whole-heart model of AF. Both combinations prolonged aERP and aPRR and thereby suppressed the induction of AF.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Maoxiao Nie ◽  
Yunfeng Yan ◽  
Xinhe Li ◽  
Tingting Feng ◽  
Xin Zhao ◽  
...  

Establishing an animal model of abdominal aortic aneurysm (AAA) is the key to study the pathogenesis and the pathophysiological features of AAAs. We investigated the effects of low-pressurized perfusion with different concentrations of elastase on aneurysm formation rate in the AAA model. Fifty male New Zealand white rabbits were randomly divided into A, B, C, D, and E groups. 10 μL of normal saline was perfused into the abdominal aorta in group A and 1 U/mL, 10 U/mL, 100 U/mL, or 200 U/mL of elastase was, respectively, perfused for the other four groups. All the animals were perfused for 7 min. Doppler ultrasound examinations of the abdominal aorta were performed before surgery and on day 14 after surgery. The rabbits were sacrificed and the perfused segment of the abdominal aorta was observed visually and after staining. The aneurysm formation rate of group A, group B, group C, group D, and group E was, respectively, 0%, 0%, 33.3%, 102.5–146.8%, and 241.5–255.2%. The survival rate of five groups was 90%, 90%, 90%, 90%, and 40%, respectively. So, we concluded that low-pressurized perfusion with 100 U/mL of elastase can effectively establish AAAs in rabbits with a high aneurysm formation rate.


2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Giovanni Pallotti ◽  
Gabriele Donati ◽  
Irene Capelli ◽  
Olga Baraldi ◽  
Giorgia Comai ◽  
...  

Different arterial wall properties can significantly increase the risk of blood turbulent fluxes leading to complications such as atherosclerosis. Since the mechanical properties of arterial vessels are influenced by age, we investigated, in a retrospective study, the effects on renal artery stenosis of an age difference >15 years between donor and recipient in a cohort of 164 patients undergoing renal transplantation between 1981 and 1991. The age difference between donor and recipient was ≤15 years in 87 patients (53.0%) (Group A) and >15 years in 77 patients (47.0%) (Group B,p=ns). None of the Group A patients developed an anastomotic arterial stenosis, whereas 8/77 Group B patients (10.4%) had an anastomotic arterial stenosis (p<0.001). This study shows that an age difference >15 years is significantly linked to the risk of developing arterial stenosis after renal transplantation. Indeed, different wall properties can significantly increase the risk of generation of blood turbulent fluxes and involve, in the arterial vessels, the development of complications such as atherosclerosis.


2014 ◽  
Vol 13 (1) ◽  
pp. 102
Author(s):  
A. H. J. AL-bdeery

The current study was conducted to evaluate the effect of different reproductive periods on some biochemical parameters (ALP, ALT, AST and GGT) in New Zealand white female rabbits. The study was carried out in the animal house of the college of veterinary medicine in Al- Qadisyia university on 21 female New Zealand white rabbits, the animals were divided to 3 groups each group contain 7 rabbits: group A as control non-pregnant rabbits, group B were pregnant rabbits and final group C were lactating female rabbits. Fresh blood samples (4 ml) were collected and centrifuged to obtained serum, then Reflotron apparatus was used for estimation of some enzymes (ALP,ALT, AST and GGT) in all groups of the experiment. The results of group A revealed that the means of (ALP, ALT, AST and GGT) were (44.54, 45.52, 20.74 and 6.08) U/L respectively, while the means of enzyme levels in group B were (105.9, 48.08, 22.68 and 6.8) U/L respectively, and the means of enzyme levels in group C were (49.9, 46.21, 21.84 and 6.72) U/L respectively. The levels of ALP in group B showed a significant increase (P<0.01) as compared with A and C groups, while there no significant increment among sera of three groups levels of (ALT, AST, and GGT).


2020 ◽  
Author(s):  
gan zhang ◽  
Xiaosong Chen ◽  
Xunsheng Cheng ◽  
Xiuwu Ma ◽  
Congcong Chen

Abstract Introduction: The experiment was undertaken to estimate the effect of BMSCs seeding in different scaffold incorporation with HBO on the repair of seawater immersed bone defect. And future compared n-HA/PLGA with β-TCP/PLGA as scaffold in treatment effect of seawater immersed bone defect.Methods: 60 New Zealand White rabbits with standard seawater defect in radius were randomly divided to group A (implant with nothing), group B (implanted with atuogenous bone), group C (implanted with n-HA/PLGA/BMSCs, and Group D ( implanted with β-TCP/PLGA/BMSCs). After implant, each rabbit receive HBO treatment at 2.4 ATA 100% oxygen for 120 minutes per day for 2 weeeks. Radiograph, histological and biomechanical examination were used to analyze osteogenesis.Result: X-ray analysis show that n-HA/PLGA/BMSCs and β-TCP/PLGA/BMSCs could accelerate the new bone formation, and the new bone formation in group C was lager than in group D or group A, and close to group B (P<0.05). After 12 weeks, in group A, defect without scaffold show a loose connect tissue filled in the areas. The medullary canal in group B was recanalizated. Defect in group C and D show a larger number of wove bone formation. The new wove bone formation in defect areas in group C was lager than D. The mechanical examination revealed ultimate strength at 12 weeks were group D>group C>group B>group A(P<0.05).Conclusion: Scaffold of n-HA/PLGA and β-TCP/PLGA incorporation with HBO and BMSCs were effective to treat seawater immersed bone defect, and n-HA/PLGA was more excellent than β-TCP/PLGA.


2020 ◽  
Author(s):  
Gan Zhang ◽  
Xiaosong Chen ◽  
Xunsheng Cheng ◽  
Xiuwu Ma ◽  
Congcong Chen

Abstract Introduction: The experiment was undertaken to estimate the effect of BMSCs seeding in different scaffold incorporation with HBO on the repair of seawater immersed bone defect. And future compared n-HA/PLGA with β-TCP/PLGA as scaffold in treatment effect of seawater immersed bone defect.Methods: 60 New Zealand White rabbits with standard seawater defect in radius were randomly divided to group A (implant with nothing), group B (implanted with atuogenous bone), group C (implanted with n-HA/PLGA/BMSCs, and Group D ( implanted with β-TCP/PLGA/BMSCs). After implant, each rabbit receive HBO treatment at 2.4 ATA 100% oxygen for 120 minutes per day for 2 weeeks. Radiograph, histological and biomechanical examination were used to analyze osteogenesis.Result: X-ray analysis show that n-HA/PLGA/BMSCs and β-TCP/PLGA/BMSCs could accelerate the new bone formation, and the new bone formation in group C was lager than in group D or group A, and close to group B (P < 0.05). After 12 weeks, in group A, defect without scaffold show a loose connect tissue filled in the areas. The medullary canal in group B was recanalizated. Defect in group C and D show a larger number of wove bone formation. The new wove bone formation in defect areas in group C was lager than D. The mechanical examination revealed ultimate strength at 12 weeks were group D > group C > group B > group A(P < 0.05).Conclusion: Scaffold of n-HA/PLGA and β-TCP/PLGA incorporation with HBO and BMSCs were effective to treat seawater immersed bone defect, and n-HA/PLGA was more excellent than β-TCP/PLGA.


Author(s):  
Taber A. Ba-Omar ◽  
Philip F. Prentis

We have recently carried out a study of spermiogenic differentiation in two geographically isolated populations of Aphanius dispar (freshwater teleost), with a view to ascertaining variation at the ultrastructural level. The sampling areas were the Jebel Al Akhdar in the north (Group A) and the Dhofar region (Group B) in the south. Specimens from each group were collected, the testes removed, fixed in Karnovsky solution, post fixed in OsO, en bloc stained with uranyl acetate and then routinely processed to Agar 100 resin, semi and ultrathin sections were prepared for study.


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