Biomedical subjects

M Bonneau

Publications and source records attributed to M Bonneau.

At least 19 recordsLinked to original sources

PubMed2006

Efficacy of particle-based DNA delivery for vaccination of sheep against FMDV.

As an alternative strategy to classical inactivated viral vaccine against FMDV, naked DNA vaccine is attractive because of safety, flexibility and low cost. However DNA vaccination is usually poorly efficient in target species. Indeed we found that naked DNA plasmids encoding for P1-2A3C3D and GM-CSF proteins did not induce any detectable immunity against FMDV in sheep. Interestingly, we demonstrate herein that formulations of DNA on poly(D,L-lactide-co-glycolide) (PLG) or in lipofectin triggered divergent types of immune responses: PLG stimulated a T cell response and could elicit significant neutralising antibody titers, whereas lipofectin generated even higher antibody titers but no significant T cell response. The DNA/PLG regimen used in five sheep protected against clinical symptoms and viraemia and prevented the carrier state in four of them. Thus formulated DNA can be remarkably efficient against FMDV in a ruminant species that is usually refractory to DNA vaccination.

Animals↗

PubMed2005

Experimental development of an endovascular graft for thoraco-abdominal aortic aneurysm repair.

AIM: Current treatment of thoraco-abdominal aortic aneurysms is surgical. Despite significant advances in surgical technique and anesthetic management, significant morbidity and mortality remain associated with their repair. In compliance with principles of reducing postoperative morbidity, we developed a thoraco-abdominal endovascular graft in experimental models of type III and type IV thoraco-abdominal aortic aneurysm. This device had to preserve the vascularization of the visceral arteries while ensuring full aneurysmal exclusion. METHODS: Six implantations of the endovascular graft were performed. This graft was a modular system, made of: 1) a custom made main body containing 4 prosthetic visceral branches, 2) 4 self-expandable stent-grafts connecting prosthetic visceral branches with visceral arteries, 3) a custom made tubular endovascular graft connecting the main body with one of the iliac arteries. RESULTS: On angiographic controls, full aneurysmal exclusion was achieved while maintaining visceral artery perfusion. At the end of each procedure, the experimental model was opened. Macroscopic examination showed harmonious thoraco-abdominal endovascular graft deployments, without abnormal component constraint or kinking. There was no discordance between macroscopic and angiographic RESULTS CONCLUSIONS: Our experimental work led to the development of a thoraco-abdominal endovascular graft, demonstrating feasibility of thoraco-abdominal aneurysm endoluminal treatment on an in vitro model close to the anatomical conditions observed in human pathology.

Angioplasty↗

PubMed2004

Activity of a synthetic hexadecasaccharide (SanOrg123781A) in a pig model of arterial thrombosis.

The activity of SanOrg123781A, a new synthetic antithrombotic drug inhibiting both factor Xa and thrombin through antithrombin (AT), was compared to that of unfractionated heparin (UFH) and of the synthetic pentasaccharide (fondaparinux, SP) in an ex vivo arterial thrombosis model in the pig. Six groups of four pigs were administered intravenously with SanOrg123781A (1, 3, 10 and 30 nmol kg(-1)), UFH (30 nmol kg(-1)) or SP (30 nmol kg(-1)). In this arterial model in which platelet thrombus was formed on a thrombogenic surface under a constant high shear rate, UFH and SP had moderate antithrombotic effects while SanOrg123781A exhibited a strong, dose-dependent inhibitory activity on platelet adhesion and platelet thrombus formation. In contrast to UFH, SanOrg123781A did not modify the activated partial thromboplastin time (aPTT) even at 30 nmol kg(-1), but strongly inhibited thrombin generation. At the same dose, despite a lower antithrombotic activity than SanOrg123781A, UFH significantly affected all the coagulation parameters. Taken together, these results show that SanOrg123781A, due to its potent and selective antifactor Xa and antifactor IIa activities is a promising new antithrombotic agent even in arterial setting.

Animals↗

PubMed2003

Detection of quantitative trait loci for fat androstenone levels in pigs.

A QTL analysis of fat androstenone levels from a three-generation experimental cross between Large White and Meishan pig breeds was carried out. A total of 485 F2 males grouped in 24 full-sib families, their 29 parents and 12 grandparents were typed for 137 markers distributed over the entire porcine genome. The F2 male population was measured for fat androstenone levels at 100, 120, 140, and 160 d of age and at slaughter around 80 kg liveweight. Statistical analyses were performed using two interval mapping methods: a line-cross (LC) regression method, which assumes alternative alleles are fixed in founder lines, and a half- full-sib (HFS) maximum likelihood method, where allele substitution effects were estimated within each half- and full-sib family. Both methods revealed genomewide significant gene effects on chromosomes 3, 7, and 14. The QTL explained, respectively, 7 to 11%, 11 to 15%, and 6 to 8% of phenotypic variance. Three additional significant QTL explaining 4 to 7% of variance were detected on chromosomes 4 and 9 using LC method and on chromosome 6 using HFS method. Suggestive QTL were also obtained on chromosomes 2, 10, 11, 13, and 18. Meishan alleles were associated with higher androstenone levels, except on chromosomes 7, 10, and 13, although 10 and 13 additive effects were near zero. The QTL had essentially additive effects, except on chromosomes 4, 10, and 13. No evidence of linked QTL or imprinting effects on androstenone concentration could be found across the entire porcine genome. The steroid chromosome P450 21-hydroxylase (CYP21) and cytochrome P450 cholesterol side chain cleavage subfamily XIA (CYP11A) loci were investigated as possible candidate genes for the chromosome 7 QTL. No mutation of coding sequence has been found for CYP21. Involvement of a candidate regulatory mutation of CYP11A gene proposed by others can be excluded in our animals.

Adipose Tissue↗

PubMed2002

Clopidogrel-induced qualitative changes in thrombus formation correlate with stent patency in injured pig cervical arteries.

Thienopyridines (ticlopidine or clopidogrel) alone or in combination with aspirin are now the reference antiplatelet therapy after stent implantation. To better understand the high efficacy and low risk of bleeding with these agents, we tested clopidogrel alone or with aspirin in an acute ex vivo flow chamber model and in a subacute in vivo arterial thrombosis model. Clopidogrel induced a dose-dependent increase in bleeding time (BT), inhibited ADP-induced platelet aggregation and in the flow chamber reduced thrombus size, and changed thrombus structure to broad-based structure composed of nondegranulated loosely attached platelets contrasting with the tight clumps of degranulated platelets seen without clopidogrel. The in vivo model involved angioplasty and stenting at the site of a preinduced arterial lesion and thrombosis in pig carotid arteries. Clopidogrel alone or with aspirin (but not aspirin alone) decreased the number of stented vessels occluded for more than 24 h and conversely reduced the number of occluding thrombus. At 96 h after stenting, 100% and 90% of the arteries were patent with clopidogrel/aspirin and clopidogrel alone, respectively (vs. 67% and 44% with aspirin and saline, respectively). Clopidogrel destabilizes thrombus without complete abolishment of platelet reactivity.

Animals↗

PubMed2001

The calcium inhibitor SR33805 reduces intimal formation following injury of the porcine carotid artery.

We studied the effect of SR33805, a calcium channel blocker, in vitro on the proliferation of vascular smooth muscle cells (SMC) stimulated by foetal calf serum, basic fibroblast growth factor and platelet derived growth factor, and in vivo with regard to SMC migration and proliferation which occurred following injury of the porcine carotid artery. The intimal lesion was induced by a silasten collar surgically positioned around the carotid artery and by a stenosis reducing blood flow by 50% for 30 days. Animals received SR33805 (5 mg/kg/day) 8 days before the induction of the lesion and up to 30 days after. In vitro, SR33805 inhibited in a dose-dependent manner growth factor-induced proliferation of SMC (0.20<IC(50)<0.46 microM). In vivo, SR33805 reduced the intima/media ratio of the cross sectional surface area (decrease of 60%, P<0.05) without affecting neointimal SMC density. The medial SMC density was 40% lower in treated than in control animals (upstream, P<0.05 and downstream to the stenosis, P<0.01). Thus, it appears that SR33805 significantly reduced intimal hyperplasia, which occurred after perivascular manipulation of the artery, an effect consistent with its in vitro proliferation inhibitory activity, suggesting that long-term treatment with SR33805 may reduce or delay SMC proliferation.

Animals↗

PubMed2001

Evaluation of renal arteries with use of gadoterate meglumine-, CO(2)-, and iodixanol-enhanced DSA measurements versus histomorphometry in renal artery restenosis in rabbits.

PURPOSE: To experimentally evaluate gadolinium (Gd)-, carbon dioxide (CO(2))-, and iodixanol-enhanced digital subtraction angiography (DSA) versus histomorphometry in the assessment of renal artery stenosis. MATERIALS AND METHODS: Fifteen male New Zealand White rabbits weighing 4.0 kg underwent percutaneous catheterization. Renal artery stenosis was induced by bilateral overdilation-deendothelialization (balloon diameter = 2 mm). The percentage of artery overdilation was 33%. After 4 weeks, the rabbits were randomized into two groups: group A underwent right-sided therapeutic percutaneous transluminal renal angioplasty (PTRA) (balloon diameter = 1.5 mm). After another 4 weeks, the renal arteries were evaluated by gadoterate-, iodixanol-, and CO(2)-enhanced selective quantitative DSA. The rabbits were then killed and renal arteries were perfusion-fixed for 60 minutes. Serial orcein-stained 4-um-thick slices were prepared for histomorphometry. RESULTS: Based on morphometric data of single-stenosis versus post-PTRA restenosis lesions, no significant difference was observed between Gd- and iodixanol-enhanced quantitative DSA (r(2) > 0.95), although the iodine/Gd density ratio was equal to 3.5. Carbon dioxide less reliably allowed quantitative DSA (r(2) < 0.75). CONCLUSION: Gd-based contrast agents represent a highly reliable alternative in experimental quantitative DSA evaluation of renal artery restenosis.

Angiography, Digital Subtraction↗

PubMed2001

Arterial blood supply to the uterus in nonpregnant sheep: a pertinent model for clinical practice?

RATIONALE AND OBJECTIVES: Our goal was to study the arterial supply to the sheep uterus to compare its similarity with that of women and to evaluate the interest of this animal model for training in uterine artery embolization. METHODS: Ten nonpregnant sheep underwent aortography and selective study of the ovarian, internal iliac, uterine, and vaginal arteries. RESULTS: The uterus was supplied mainly by the uterine arteries in all sheep. The ovarian artery, which was identified in five sheep, had a thin anastomosis with the ipsilateral uterine artery at the tubal junction. The vaginal artery provided blood flow to the inferior part of the cervix and anastomosed with the ipsilateral uterine artery. CONCLUSIONS: Because uterine vascularization of nonpregnant sheep is similar to that of women, the sheep represents an appropriate model for experimental uterine artery embolization. This model should be used for interventional radiologists in training not familiar with endovascular navigation inside pelvic arteries.

Angiography↗

PubMed2000

Ultrasonic methodology coupled to ATP bioluminescence for the non-invasive detection of fouling in food processing equipment--validation and application to a dairy factory.

The use of an ultrasonic apparatus (40 kHz) for the non-destructive, rapid and reproducible removal of biofilm from standard materials (stainless steel and polypropylene) in a dairy factory was investigated. The application of ultrasound with the tested conditions (10 s and 40 kHz) was found not to be detrimental for standard ATP (concentration ranging between 5 x 10(-9) and 10(-5) mol 1(-1)) and for prokaryotic cells, including both rods and coccoid-shaped bacteria (Escherichia coli and Staphylococcus aureus). It allowed the use of the ATP bioluminescence measurement for quantifying the biofilm removal. The repeatability of industrial milk removal was determined on fouled stainless steel and polypropylene sheets. The variability of the results with the sonication method was constant, +/-24% (coefficient of variation) for both surfaces, and was variable with the swabbing method, +/-42% for the stainless steel sheet and +/-74% for the polypropylene sheet. The ultrasonic apparatus removed twice the amount of industrial milk biofilm compared with the swabbing method in the case of the polypropylene sheets. The apparatus was used to validate the industrial cleaning protocols of a milk factory.

Adenosine Triphosphate↗

PubMed2000

The development of an ultrasonic apparatus for the noninvasive and repeatable removal of fouling in food processing equipment.

A new ultrasonic apparatus operating at a frequency of 40 kHz was developed to dislodge biofilms from food processing equipment in order to assess the effectiveness of cleaning protocols. Sonication conditions to remove biofilms and quantification by ATP-bioluminescence are described. An industrial meat process was developed at the laboratory level to form a biofilm with industrial characteristics. Our results show that the biofilm removal by sonication during 10 s is reproducible and four times greater compared to the swabbing method (83% removal of fouling material against 20%). Unlike the swabbing method, this ultrasonic apparatus permitted the immediately demonstration of the inefficiency (within 1 min) of an industrial meat cleaning protocol. This apparatus is portable, easy to use and can be operated by unskilled users.

Biofilms↗

PubMed2000

Restricted feed intake during fattening reduces intramuscular lipid deposition without modifying muscle fiber characteristics in rabbits.

The present study was conducted to determine the effects of feed restriction during fattening on muscle fiber characteristics and intramuscular lipid traits. From 11 wk of age onward, rabbits were given free access to feed (control group), or received 70% of the control feed intake (restricted group). At the same weight at slaughter, restricted-fed rabbits were 3 wk older than controls (18 vs. 15 wk). The longissimus lumborum (LL, white loin), biceps femoris (BF, white thigh) and semimembranosus proprius (SMP, red thigh) muscles were then removed, and biochemical and histochemical assays were performed. In the three muscles, there was no effect of feed restriction on mean fiber size or percentage of the different fiber types. Restricted vs. control feeding resulted in a significant reduction (P<0.001) in total lipid content in all three muscles. This reduction was paralleled by a decline (P<0.001) in the activities of the malic enzyme and glucose-6 phosphate dehydrogenase (G6PDH), generating NADPH for the support of fatty acid synthesis. The diet-induced variations in lipid concentration and enzyme activities were larger (P<0.05) in the pure oxidative SMP muscle than in the predominantly fast-twitch glycolytic LL and BF muscles. Whatever feeding status, the ratio of malic enzyme to G6PDH activities was sharply lower (P<0.001) in SMP than in BF and LL muscles (averaging 1.5 vs. 9 and 15, respectively). These data indicate that nutritional status regulates intramuscular lipid deposition, without changing fiber-type composition. Further studies are necessary to determine the role of G6PDH in the lipogenic process of oxidative vs. glycolytic muscles.

Analysis of Variance↗

PubMed1999

Use of von Willebrand diseased kidney as donor in a pig-to-primate model of xenotransplantation.

BACKGROUND: The coagulation process in hyperacute and delayed xenograft rejection is essential and depends upon platelet adhesion and aggregation. The initial binding of platelets to the damaged endothelium is due to the interaction of the platelet receptor glycoprotein Ib with von Willebrand factor (vWF), which is present on activated endothelial cells and bound to the subendothelial matrix. We hypothesized that the use of organs from animals with homozygous von Willebrand disease (vWD), severely deficient in vWF, might prevent the thrombosis encountered in delayed xenograft rejection. METHODS: Ten baboons were treated by extracorporeal immunoadsorption of xenoreactive natural antibodies (XNA) through the donor pig liver to inhibit hyperacute rejection and received heterotopic vWD or control pig kidney xenografts. XNA levels, coagulation, and platelet activation markers were studied, and specimens of rejected kidneys were analyzed histologically. RESULTS: Although XNA depletion was comparable in both groups, neither kidney function nor survival times of control (n=5) or vWD (n=5) porcine kidneys showed any difference. Platelet and coagulation activation was evidenced in both groups after surgery and at rejection time. Immunohistochemical analysis revealed a weak endothelial vWF immunostaining in the rejected vWD kidneys, whereas it was undetectable in the nongrafted vWD kidneys, suggesting the deposition of baboon plasma vWF on the porcine vessels. CONCLUSIONS: The use of vWD organs did not improve the survival time of grafted kidneys in this xenotransplantation model. Further studies on the use of vWD organs, in association with other therapeutic approaches, such as complement inhibition, are nevertheless necessary to evaluate the usefulness of vWF deficiency as an adjunctive therapy to decrease the coagulation process during xenograft rejection.

Animals↗

PubMed1999

Effects of contrast media on blood rheology: comparison in humans, pigs, and sheep.

PURPOSE: To compare whole blood viscosity and erythrocyte aggregation in humans, pigs, and sheep, before and after adding water-soluble iodinated contrast medium (CM). METHODS: Two CMs were studied: iopromide (nonionic) and ioxaglate (ionic). The blood-CM viscosity was measured with a Couette viscometer. Erythrocyte aggregation was measured with an erythroaggregometer. RESULTS: The blood-CM viscosity was increased up to +20% (relative to pure blood) with a CM concentration of 0%-10%. At CM concentrations from 10% to 50%, the viscosity decreased. The disaggregation shear stress was increased (relative to pure blood) at low CM concentration (0%-10%). When the CM concentration increased from 10% to 20%, the disaggregation shear stress was decreased, except with the pig blood-ioxaglate mixture. CONCLUSION: At low CM concentration the blood viscosity was increased in pig, sheep, and humans and the disaggregation shear stress was increased in pig and humans. The aggregation of sheep blood was too low to be detected by the erythroaggregometer. This rise can be explained by the formation of poorly deformable echinocytes. At higher CM concentration, the viscosity and the disaggregation shear stress decreased in relation to the blood dilution. We conclude that pig blood and sheep blood can both be used to study the effect of CM injection on blood viscosity. Nevertheless, the rheologic behavior of pig blood in terms of erythrocyte aggregation is closer to that of human blood than is sheep blood when mixed with CM. Pigs could thus be more suitable than sheep for in vivo studies of CM miscibility with blood during selective cannulation procedures.

Animals↗

PubMed1999

In vivo regulation of von willebrand factor synthesis: von Willebrand factor production in endothelial cells after lung transplantation between normal pigs and von Willebrand factor-deficient pigs.

To evaluate the regulation of plasma von Willebrand factor (vWF) and its in situ production by endothelial cells (ECs), 12 swine leukocyte antigen (SLA)-compatible left lung transplantations were performed. Normal lungs were transplanted into 10 pigs homozygous for von Willebrand disease and into 2 normal pigs. Additionally, 1 normal pig underwent pneumonectomy, and 1 SLA-incompatible lung transplantation between normal pigs was performed. None of the transplanted animals received immunosuppressive therapy. Plasma vWF level was evaluated by ELISA and multimeric pattern. EC vWF content was assessed by immunohistochemistry. Global hemostasis was assessed by standardized ear bleeding time. Six of 12 SLA-compatible lung transplantations and the incompatible transplantation were successful and were used for the study. The functions and the viability of ECs, reflected by their ability to produce vWF and normal multimeric plasma vWF pattern, were preserved in SLA-compatible and -incompatible lung transplantations. vWF production was preserved in ECs that initially synthesized it. EC constitutive and storage pathways are modulated differently according to transplantation compatibility and severity of rejection. In SLA-compatible lung transplantations without histological evidence of rejection, the production of vWF was preserved, whereas constitutive vWF secretion appeared to be altered in cases with minor histological signs of rejection. In pigs with von Willebrand disease that were transplanted with normal lungs without sign of rejection, plasma vWF was significantly increased in an amount expected from the estimated production of a normal lung. In the transplanted normal lung, there was no vWF overexpression by the ECs and no recruitment of ECs that initially did not express vWF. In SLA-incompatible transplantation, ECs were morphologically normal with increased and blurred vWF labeling, whereas plasma vWF levels remained normal, reflecting that EC activation is associated with an increased vWF production with probable diversion to storage pathway. This model depicts the changes of EC regulation of vWF secretion in pig lung transplants. However, this model cannot be directly extrapolated to human organ transplantation because animals did not receive any immunosuppressive therapy, which may be toxic to ECs.

Acute Disease↗

PubMed1999

Relative development of subcutaneous, intermuscular, and kidney fat in growing pigs with different body compositions.

A total of 94 pigs from seven groups considered as lean (boars from a synthetic line and the Pietrain breed), conventional (boars, gilts, and barrows from the Large White breed), fat (barrows from the Meishan x Large White cross), or obese (Meishan barrows) were serially slaughtered between 12 and 110 kg BW. Carcasses were dissected into muscle, bone, skin, and fat, which was further separated into subcutaneous, intermuscular, and kidney fats. Subcutaneous fat accounted for 60 to 70% of body fat and intermuscular fat for 20 to 35% of body fat. Relative to total fat, intermuscular fat grew more slowly (allometric growth coefficients generally < 1), subcutaneous fat at the same rate (b close to 1), and kidney fat more rapidly (1.12 < b < 1.33). The leaner the animals genetically, the higher the proportion of intermuscular fat in total fat. The ratio of intermuscular to subcutaneous fat varied from .31 in Meishan barrows to .66 in Pietrain boars. Overall, the ratio of intermuscular fat to muscle weight or body weight was positively related to the development of total fat. However, Pietrain pigs were unique in having a high development of intermuscular fat. The present results suggest that 1) the genetic controls of the development of intermuscular and subcutaneous fat are partially independent and 2) the development of intermuscular fat may be determined at an early stage, before 20 kg BW.

Adipose Tissue↗

PubMed1999

Macro and microheterogeneity in normal endothelial cells: differential composition of luminal glycocalyx and functional implications.

Endothelial cells (EC) are involved in various physiological and pathological processes through the expression of their surface glycoproteins. They are covered by the glycocalyx, composed of glucidic residues from cell surface membrane glycoproteins, glycoplipids and proteoglycans. Glucidic sequences can be specifically characterized by their binding to lectins. Eight lectins were used to investigate the distribution and regulation of EC surface glucidic residues in various blood vessels of adult and newborn pigs. EC lectin binding was compared to von Willebrand factor (vWF) expression as EC reference marker. Six out of eight lectins (BSI-B4, DBA, EEA, HP, MAL I and PNA) were helpful for this determination. Considering only the intensity of labelings, vWF and DBA gave the best stainings of adult pig ECs. In newborn pigs, the best labelings were obtained with EEA and MAL I. Furthermore, the distribution of lectin binding to ECs and EC vWF expression was heterogeneous depending on the EC location along vascular tree and age. Beside this macroheterogeneity this study highlights a microheterogeneity of EC lectin binding and vWF expression in situ, defined as a staining of equal intensity by individual ECs, scattered among negative ones, in a given vascular segment. EC surface sugar residues were differently modulated in newborn and adult pig ECs and differently according to EC vWF expression. The functional involvement of EC glycocalyx was reflected by EC lectin binding in the spleen and liver. This study emphasizes the high level of EC heterogeneity for various markers. The EC macro- and microheterogeneity reflect the "plasticity" or "unstability" of EC phenotypes and suggests that ECs are subject to several levels of regulation and are probably grouped in functional clusters to best adjust their functions to microenvironmental requirements. This concept must be considered in further investigations notably in in vitro studies where EC phenotype can be altered.

Animals↗

PubMed1998

Effects of human recombinant, plasma-derived and porcine von Willebrand factor in pigs with severe von Willebrand disease.

The effects of the infusion of a human recombinant von Willebrand factor (vWF) preparation in pigs homozygous for von Willebrand disease (vWD) were evaluated on serial measurements of von Willebrand factor antigen and activity, FVIII activity, vWF multimer analysis, in-vivo bleeding time and platelet adhesion and thrombus formation on collagen at high shear rates in an ex-vivo model of experimental thrombosis. Plasma-derived human and porcine vWF were used for comparison. Before infusion, the pigs were characterized by undetectable plasma vWF levels, a low level of FVIII, prolonged bleeding time, severely impaired platelet adhesion and thrombus formation. After infusion of the human recombinant vWF, in-vivo recovery of vWF activity ranged from 58% to 82%, depending on the dose infused, and its half-life was longer than for the plasma-derived concentrates. The highest-molecular-weight forms of human recombinant vWF were removed from the circulation gradually. Infusion of the three vWF concentrates produced inconsistent effects on bleeding time and moderate improvement of platelet adhesion and thrombus formation. After infusion, a prolonged increase of FVIII (> 48 h) was observed, suggesting that human recombinant vWF is able to bind and to stabilize porcine factor VIII and that porcine vWD is a good model for studying such interactions.

Animals↗

PubMed1998

Abdominal aortic aneurysms in sheep: prevention of rupture with endoluminal stent-grafts.

PURPOSE: The authors evaluated the ability of an aortic balloon-expandable endovascular stent-graft to prevent rupture in a model of spontaneously rupturing abdominal aortic aneurysms in sheep. MATERIALS AND METHODS: Aneurysms were created in 16 sheep by inserting a 60 x 18-mm segment of the left internal jugular vein, end-to-end anastomosed, to the sectioned infrarenal abdominal aorta. The sheep were randomly assigned into two groups; eight animals underwent endovascular implantation of an 80 x 12-mm balloon expandable stent-graft (group A), and eight were only followed up (group B). RESULTS: In group B, seven of eight animals had died of aneurysmal rupture by 3 months. In group A, six of the eight aortic aneurysms were immediately excluded, and six animals were alive at 3 months without rupture. The 3-month survival rate was 100% in group A and 12% in group B (P = .0023). Macro- and microscopic analysis of the section of the aorta in which the stent-graft had been placed revealed rapid retraction of the aneurysmal sac. CONCLUSION: Placement of an endovascular stent-graft induced regression of a branchless aneurysm and prevented rupture.

Animals↗