RESUMEN
An 88-year-old diabetic women was hospitalized because of a pheripheral vascular disorder. During her hospitalization she developed a right-sided facial swelling which was not limited by anatomical structures in this area. Ultrasound and computertomographic scanning supported the clinical diagnosis acute sialoadenitis of the parotid gland. The swelling resolved shortly after starting antibiotic therapy.
Asunto(s)
Antiinfecciosos/uso terapéutico , Glándula Parótida/patología , Sialadenitis/diagnóstico , Tuberculosis Bucal/diagnóstico , Enfermedad Aguda , Anciano de 80 o más Años , Mejilla/diagnóstico por imagen , Mejilla/patología , Femenino , Humanos , Glándula Parótida/diagnóstico por imagen , Sialadenitis/diagnóstico por imagen , Sialadenitis/tratamiento farmacológico , Resultado del Tratamiento , Tuberculosis Bucal/diagnóstico por imagen , Tuberculosis Bucal/tratamiento farmacológico , UltrasonografíaRESUMEN
An 88-year-old woman developed right-sided facial swelling due to acute sialoadenitis of the parotid and submandibular glands.
Asunto(s)
Cara/patología , Glándula Parótida/patología , Sialadenitis/patología , Glándula Submandibular/patología , Enfermedad Aguda , Anciano , Anciano de 80 o más Años , Antiinfecciosos/uso terapéutico , Femenino , Humanos , Sialadenitis/diagnóstico , Sialadenitis/tratamiento farmacológico , Resultado del TratamientoRESUMEN
BACKGROUND: Hyperhomocysteinaemia is an independent risk factor for atherosclerosis and is thought to induce its effects through causing endothelial dysfunction. We studied the effect of homocysteine-lowering treatment with folic acid plus vitamin B6 on urinary and plasma markers of endothelial function, and on plasma C-reactive protein, a marker of chronic inflammation. DESIGN: We performed a placebo-controlled 2-year trial among 158 healthy siblings of patients with premature atherosclerotic disease to determine the effect of daily folic acid (5 mg) plus vitamin B6 (250 mg) treatment as compared with placebo medication (n = 80) on markers of endothelial function (urinary albumin-to-creatinine ratio and plasma concentrations of soluble E-selectin, soluble vascular cell adhesion molecule-1, von Willebrand factor, tissue-type plasminogen activator and plasminogen activator inhibitor-1) and inflammation (C-reactive protein). Outcome variables were assessed at baseline and after 1 and 2 years of treatment. RESULTS: Fasting homocysteine concentrations ( micromol L-1) at baseline and after treatment were 14.7 +/- 8.2 and 7.4 +/- 1.9 in the vitamin and 14.7 +/- 8.8 and 12.0 +/- 5.4 for the placebo group, respectively. Vitamin treatment was associated with a decreased urinary albumin-to-creatinine ratio at follow up [regression coefficient (beta) -0.20 mg mmol-1 (CI: -0.43-0.03); P = 0.09]. After adjustment for age, sex, baseline concentrations of postmethionine total homocysteine plus the baseline albumin-to-creatinine ratio, the beta was -0.23 mg mmol-1 (CI: -0.43 to -0.02; P = 0.03), which amounts to a decrease of approximately 20%. There was no apparent effect of vitamin treatment on the other markers. CONCLUSIONS: Homocysteine-lowering vitamin treatment in healthy siblings of patients with premature atherosclerotic disease is associated with a decreased urinary albumin-to-creatinine ratio, but not with other markers of endothelial dysfunction, or in plasma C-reactive protein. The clinical significance of these findings remains to be determined.
Asunto(s)
Albuminuria/orina , Proteína C-Reactiva/metabolismo , Endotelio/efectos de los fármacos , Ácido Fólico/uso terapéutico , Hiperhomocisteinemia/prevención & control , Vitamina B 6/uso terapéutico , Adulto , Arteriosclerosis/etiología , Biomarcadores , Humanos , Hiperhomocisteinemia/complicaciones , Persona de Mediana EdadRESUMEN
BACKGROUND: Mild hyperhomocysteinaemia (HHC) is associated with an increased risk of premature atherothrombotic cerebrovascular disease. We investigated the clinical efficacy with regard to the incidence of cardiovascular events of treatment of mild HHC with vitamin B(6) plus folic acid. METHODS: We studied 224 consecutive patients with clinically manifest atherothrombotic cerebrovascular disease with onset before the age of 56. Follow-up was obtained in 203 (90.6%) patients. At baseline, 52 (25.6%) were hyperhomocysteinaemic after methionine loading and started treatment with vitamin B(6) (250 mg) plus folic acid (5 mg); 151 (74.4%) were normohomocysteinaemic (reference group). RESULTS: During follow-up (median 57 months), 31 (20.5%) of the normo- and 11 (21.2%) of the hyperhomocysteinaemic patients had a new cardiovascular event. The crude incidence rate per person-year for any cardiovascular event was similar in both groups (0.043 [CI, 0.029-0.057] in the normo- vs. 0.045 [CI, 0.021-0. 069] in the hyperhomocysteinaemic group). Multivariate Cox-regression analyses showed that hypertension and cholesterol levels were associated with an increased risk of new cardiovascular events in the total group [relative risk [RR] (yes vs. no), 7.4 (3. 4-16.0) and RR (per 1 mmol/l), 1.9 (CI, 1.4-2.7)]. The adjusted RR for new cardiovascular events in the hyper- as compared to the normohomocysteinaemic patients was 0.96 (CI, 0.48-1.92). CONCLUSION: These data are consistent with a protective effect of treatment with vitamin B(6) plus folic acid in patients with premature atherothrombotic cerebrovascular disease and post-methionine HHC.
Asunto(s)
Arteriosclerosis/tratamiento farmacológico , Ácido Fólico/uso terapéutico , Hematínicos/uso terapéutico , Hiperhomocisteinemia/diagnóstico , Hiperhomocisteinemia/tratamiento farmacológico , Piridoxina/uso terapéutico , Accidente Cerebrovascular/prevención & control , Adulto , Arteriosclerosis/complicaciones , Femenino , Estudios de Seguimiento , Humanos , Hiperhomocisteinemia/genética , Ataque Isquémico Transitorio/prevención & control , Masculino , Tamizaje Masivo , Metionina , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Resultado del TratamientoRESUMEN
BACKGROUND: A high plasma homocysteine concentration is associated with increased risk of atherothrombotic disease. We investigated the effects of homocysteine-lowering treatment (folic acid plus vitamin B6) on markers of subclinical atherosclerosis among healthy siblings of patients with premature atherothrombotic disease. METHODS: We did a randomised, placebo-controlled trial among 158 healthy siblings of 167 patients with premature atherothrombotic disease. 80 were assigned placebo and 78 were assigned 5 mg folic acid and 250 mg vitamin B6 daily for 2 years. The primary endpoint was the development or progression of subclinical atherosclerosis as estimated from exercise electrocardiography, the ankle-brachial pressure index, and carotid and femoral ultrasonography. FINDINGS: Ten participants in the treatment group, and 14 in the placebo group dropped out. Vitamin treatment, compared with placebo, was associated with a decrease in fasting homocysteine concentration (from 14.7 to 7.4 micromol/L vs from 14.7 to 12.0 micromol/L), and in postmethionine homocysteine concentration (from 64.9 to 34.9 micromol/L vs from 64.8 to 50.3 micromol/L). It was also associated with a decreased rate of abnormal exercise electrocardiography tests (odds ratio 0.40 [0.17-0.93]; p=0.035). There was no apparent effect of vitamin treatment on ankle-brachial pressure indices (0.87 [0.56-1.33]), or on carotid and peripheral-arterial outcome variables (1.02 [0.26-4.05] and 0.86 [0.47-1.59], respectively). INTERPRETATION: Homocysteine-lowering treatment with folic acid plus vitamin B6 in healthy siblings of patients with premature atherothrombotic disease is associated with a decreased occurrence of abnormal exercise electrocardiography tests, which is consistent with a decreased risk of atherosclerotic coronary events.
Asunto(s)
Enfermedad de la Arteria Coronaria/prevención & control , Ácido Fólico/uso terapéutico , Hematínicos/uso terapéutico , Hiperhomocisteinemia/tratamiento farmacológico , Piridoxina/uso terapéutico , Presión Sanguínea , Enfermedad de la Arteria Coronaria/etiología , Familia , Femenino , Ácido Fólico/sangre , Hematínicos/sangre , Humanos , Hiperhomocisteinemia/complicaciones , Masculino , Metionina/administración & dosificación , Metionina/sangre , Persona de Mediana Edad , Piridoxina/sangre , Factores de RiesgoRESUMEN
To assess the variability of plasma homocysteine levels, fasting and post-methionine homocysteine levels were measured twice, at baseline and after follow-up of 1-4 months, in 16 individuals with normal and 26 with elevated homocysteine levels after methionine loading. The intra-individual coefficients of variation varied from 15 to 23% for fasting and post-methionine homocysteine levels, whether these levels were within the normal range or not. As a result, test-retest agreement was poor when subjects were dichotomized as having 'normal' or 'abnormal' homocysteine levels (itself a questionable concept). There was a relation between the average post-methionine homocysteine levels (at the first and second measurement) and the difference between both measurements (r = 0.37, P = 0.016). In normohomocysteinaemic individuals, delta (i.e., the difference between baseline and follow-up) fasting homocysteine and delta post-methionine homocysteine were correlated negatively with delta folate serum levels: r = -0.64, P = 0.007 and r = -0.50, P = 0.05, respectively. Individuals homozygous for the 677 C-->T mutation in the 5,10-methylenetetrahydrofolate reductase gene showed a greater variation of fasting homocysteine levels than those homozygous for the wild type (P = 0.017). In summary, we suggest that there is a substantial intra-individual variability in plasma homocysteine levels over time and that this variability is significantly related to the variability in serum folate levels, especially in normohomocysteinaemic individuals.
Asunto(s)
Ayuno/fisiología , Homocisteína/sangre , Hiperhomocisteinemia/diagnóstico , Hiperhomocisteinemia/fisiopatología , Metionina , 5,10-Metilenotetrahidrofolato Reductasa (FADH2) , Adulto , Análisis de Varianza , Femenino , Ácido Fólico/sangre , Ácido Fólico/fisiología , Homocisteína/fisiología , Homocigoto , Humanos , Masculino , Metionina/metabolismo , Metilenotetrahidrofolato Reductasa (NADPH2) , Persona de Mediana Edad , Mutación , Oxidorreductasas/genética , Estadísticas no ParamétricasRESUMEN
OBJECTIVES: Mild hyperhomocysteinaemia (HHC), fasting or after methionine loading, is associated with an increased risk and severity of atherosclerotic vascular disease. Post-methionine and fasting HHC are responsive to treatment with vitamin B, and folic acid. We performed a prospective cohort study amongst normohomocysteinaemic and vitamin-treated (vitamin B6, 250 mg plus folic acid, 5 mg daily) hyperhomocysteinaemic patients with premature peripheral arterial occlusive disease and assessed the incidence of cardiovascular events. DESIGN: We studied 273 consecutive patients with clinically manifest peripheral arterial occlusive disease with onset before the age of 56, 79 (28.9%) of whom had postmethionine HHC. Follow-up was obtained in 232 (85'%o) patients. At baseline, 70 (30')/) were hyperhomocysteinaemic after methionine loading and started treatment with vitamin B, and folic acid; 162 (70%) were normohomocysteinaemic (reference group). RESULTS: During the follow-up period (median 20, range 1-63 months), 48 (29.6%) and 23 (32.9%) of the normo- and the hyperhomocysteinaemic patients, respectively, had a new cardiovascular event. Most (75%) involved the peripheral arterial system. The crude incidence rate for any cardiovascular event was 0.16 (95% CI, 0.12-0.21) per person per year in the normohomocysteinaemic and 0.16 (95% CI, 0.09-0.22) per person per year in the hyperhomocysteinaemic group. Multivariate Cox regression analyses showed that higher plasma homocysteine levels were associated with an increased risk of new cardiovascular events in the normohomocysteinaemic patients (relative risk [RR] per 1 micromol L(-1), 1.17 [CI, 1.05-1.30] for fasting and 1.06 [CI, 1.01-1.12] for postmethionine levels), but not in the hyperhomocysteinaemic (vitamin-treated) patients. The adjusted RR for new cardiovascular events in the hyper- as compared to the normohomocysteinaemic patients was 0.76 (CI, 0.33-1.74). CONCLUSIONS: These data are consistent with a protective effect of treatment with vitamin B6 and folic acid in patients with premature peripheral arterial occlusive disease and postmethionine HHC. Double-blind randomized trials are necessary to confirm this.
Asunto(s)
Arteriopatías Oclusivas/complicaciones , Enfermedades Cardiovasculares/etiología , Ácido Fólico/uso terapéutico , Homocisteína/sangre , Hiperhomocisteinemia/complicaciones , Hiperhomocisteinemia/tratamiento farmacológico , Piridoxina/uso terapéutico , Adulto , Edad de Inicio , Anciano , Arteriopatías Oclusivas/sangre , Enfermedades Cardiovasculares/sangre , Femenino , Humanos , Hiperhomocisteinemia/sangre , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Riesgo , Factores de RiesgoRESUMEN
OBJECTIVE: To review our 10-year experience of reconstruction of the supra-aortic trunks. DESIGN: Retrospective study. SETTING: Teaching hospital, The Netherlands. SUBJECTS: 47 patients who required reconstruction of the supra-aortic trunks for stenotic or occlusive disease between April 1987 and May 1997. INTERVENTIONS: Right-sided bifurcation graft through a sternotomy (n = 25), left-sided thoracotomy (n = 1), and extra-anatomic bypass (n = 21). MAIN OUTCOME MEASURES: Morbidity, mortality, and long term patency. RESULTS: 3 patients died (6%); 7 (15%) developed major complications (leak from the brachiocephalic stump, n = 2, and acute occlusion of the bypass graft, n = 5) all of which were successfully treated by immediate reoperation; and 9 (19%) developed minor complications, all of which resolved within 3 months. The median follow up was 36 months (range 1-108), and the 3-year patency rate was 80%. No patient died during the follow up period, but a further 3 were lost to follow up. The remaining 41 were all assessed by duplex scanning or angiography, and 3 required further operation for recurrent symptoms; 33 remained completely free of symptoms. CONCLUSION: Symptomatic stenotic or occlusive lesions of the supra-aortic trunks can be treated with acceptable morbidity and mortality, giving long term benefit to patients.
Asunto(s)
Arteriopatías Oclusivas/cirugía , Implantación de Prótesis Vascular , Tronco Braquiocefálico/cirugía , Arterias Carótidas/cirugía , Arteria Subclavia/cirugía , Estenosis Carotídea/cirugía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo , Grado de Desobstrucción VascularRESUMEN
Elevated plasma total homocysteine (tHcy) levels, either measured in the fasting state or after oral methionine loading, are associated with an increased risk of atherothrombotic disease. Fasting and post-methionine hyperhomocysteinemia (HHC) overlap to a limited extent; both can occur as familial traits. We investigated determinants of fasting, postmethionine and delta (ie, post-methionine minus fasting levels) tHcy levels in 510 subjects of 192 HHC-prone families including 161 patients with clinical vascular disease and 349 without vascular disease. We focused on tHcy levels in relation to levels of vitamin B12, B6 and folate and the methylenetetrahydrofolate reductase (MTHFR) C677T mutation. Multivariate linear analyses adjusted for the presence of vascular disease showed that fasting tHcy was significantly related to folate and vitamin B12, and the presence of the MTHFR TT genotype and the T allele, and to age, smoking habits, and serum levels of creatinine. Both post-methionine and delta tHcy levels were related to serum folate levels, and the presence of the MTHFR TT genotype and the T allele, and to postmenopausal status, and body mass index. An interaction was found between MTHFR TT genotype and serum folate levels for both fasting and post-methionine tHcy, ie, for a given decrease in serum folate, homocysteine levels increased more in subjects with the TT genotype than in those with the CC genotype. Fasting, post-methionine and delta tHcy were higher in patients with vascular disease than in their healthy siblings, but these levels were less dependent on serum folate levels (P<0.05), whereas the effect of MTHFR genotype was stronger (P=0.01). This study found evidence that post-methionine and delta tHcy levels are not only influenced by factors affecting homocysteine transsulfuration but also by factors that affect remethylation. The explained variances of fasting, post-methionine and delta tHcy were 49%, 62%, and 78%, respectively. We also found evidence, in patients with premature vascular disease but not in their healthy siblings, for a factor that increases tHcy levels but weakens the normal inverse relation between folate and tHcy and amplifies the effect of the MTHFR genotype.
Asunto(s)
Arteriosclerosis/genética , Homocisteína/sangre , Hiperhomocisteinemia/sangre , Metionina , Adulto , Factores de Edad , Sustitución de Aminoácidos , Índice de Masa Corporal , Comorbilidad , Ayuno/sangre , Femenino , Ácido Fólico/sangre , Predisposición Genética a la Enfermedad , Genotipo , Homocisteína/biosíntesis , Humanos , Hiperhomocisteinemia/genética , Hipertensión/epidemiología , Lípidos/sangre , Masculino , Menopausia , Metionina/farmacocinética , Metilenotetrahidrofolato Reductasa (NADPH2) , Persona de Mediana Edad , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/genética , Polimorfismo Genético , Piridoxina/sangre , Fumar/epidemiología , Vitamina B 12/sangreRESUMEN
Hyperhomocysteinemia is an independent risk factor for atherothrombotic disease. The mechanism by which homocysteine induces atherosclerosis and thrombosis is not fully understood. Data on arterial histology in humans with homocystinuria and mild hyperhomocysteinemia are limited. In vitro studies as well as studies in animals and humans indicate that hyperhomocysteinemia induces dysfunction of the vascular endothelium, with loss of endothelium-dependent vasodilation and endothelial antithrombotic properties, and proliferation of vascular smooth muscle cells, which are key processes in current models of atherogenesis and thrombosis. One of the hypotheses is that homocysteine can lead to cellular dysfunction through a mechanism involving oxidative damage but future studies in humans are needed to confirm this. Studies in hyperhomocysteinemic vascular patients have shown that endothelial antithrombotic properties appear to be more severely impaired than in similar patients with normohomocysteinemia. Furthermore, impaired endothelium-dependent vasodilation has been observed in clinically healthy hyperhomocysteinemic subjects in whom no abnormalities were found in endothelial antithrombotic properties. Future studies involving homocysteine-lowering treatment in hyperhomocysteinemic patients with vascular disease and in clinically healthy hyperhomocysteinemic subjects are necessary to investigate the mechanisms by which homocysteine causes atherothrombotic disorders in humans.
Asunto(s)
Arteriosclerosis/etiología , Hiperhomocisteinemia/complicaciones , Trombosis/etiología , Arteriosclerosis/fisiopatología , Factores de Coagulación Sanguínea/fisiología , Plaquetas/fisiología , Endotelio Vascular/fisiología , Humanos , Hiperhomocisteinemia/fisiopatología , Trombosis/fisiopatologíaRESUMEN
Hyperhomocysteinemia (HHC) is associated with an increased risk of atherosclerotic vascular disease and may be inherited. Fasting and postmethionine HHC are independent risk factors that overlap to a limited extent. To study the familial occurrence of HHC, we investigated the prevalence of HHC (both fasting and after methionine) among 450 siblings of 167 consecutive young patients with vascular disease and postmethionine HHC. Furthermore, all subjects with postmethionine HHC (n = 125) were invited for noninvasive vascular testing; 101 (80.8%) agreed. Of those with a normal postmethionine plasma level (n = 325), we randomly selected 73 subjects for further studies; 53 agreed (72.6%). Thus, a total of 154 siblings underwent ultrasonography of the carotid arteries, measurement of ankle-brachial pressure indices at rest and after a treadmill exercise test, and exercise electrocardiographic stress testing. We observed HHC after methionine, fasting, or both, in 27.8% (95% CI, 23.7 to 31.9), 11.1% (CI, 8.2 to 14.0) and 8.7% (CI, 6.1 to 11.3) of the siblings. Abnormal peripheral, coronary, or carotid artery tests were observed in 35.7% (CI, 28.1 to 43.3), 7.1% (CI, 3.0 to 11.2), and 7.1% (CI, 3.0 to 11.2). Univariate and multivariate analyses revealed weak evidence of a relationship with homocysteine levels. In conclusion, we found a high prevalence of HHC and asymptomatic vascular disease in siblings of young patients with vascular (mainly peripheral arterial) disease and HHC. Our data raise the possibility that homocysteine does not play a major role in the early, asymptomatic phases of vascular disease, at least among siblings of young patients with vascular disease.
Asunto(s)
Homocisteína/sangre , Enfermedades Vasculares/genética , Adulto , Presión Sanguínea , Estenosis Carotídea/diagnóstico por imagen , Estenosis Carotídea/epidemiología , Diabetes Mellitus/epidemiología , Susceptibilidad a Enfermedades , Ecocardiografía , Prueba de Esfuerzo , Ayuno , Femenino , Humanos , Hipercolesterolemia/epidemiología , Hipertensión/epidemiología , Masculino , Tamizaje Masivo , Metionina/sangre , Persona de Mediana Edad , Análisis Multivariante , Núcleo Familiar , Prevalencia , Factores de Riesgo , Método Simple Ciego , Fumar/epidemiología , Enfermedades Vasculares/sangreRESUMEN
Hyperhomocysteinemia is associated with severe, premature atherosclerosis and thromboembolism. The mechanisms involved in the atherogenic and thrombotic complications of hyperhomocysteinemia are not understood. It has been suggested that hyperhomocysteinemia predisposes to atherosclerosis by injuring the vascular endothelium. Whether hyperhomocysteinemia is independently associated with changed endothelial function, either in the absence or the presence of clinically manifest atherosclerotic disease, is, however, not known. Therefore we investigated, both in patients with peripheral arterial occlusive disease and in healthy individuals, whether plasma protein markers of endothelial function differed between subjects with, and subjects without hyperhomocysteinemia. We studied 80 individuals under the age of 56 years: healthy individuals with (n = 20) and without (n = 20) hyperhomocysteinemia and patients with peripheral arterial occlusive disease with (n = 20) and without (n = 20) hyperhomocysteinemia. The following endothelium-derived proteins were measured as markers of endothelial cell function: von Willebrand factor (vWf) and von Willebrand factor propeptide (vWf: AgII), tissue-type plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1), cellular fibronectin (cFN) and thrombomodulin (TM). In addition we assessed C-reactive protein (CRP). vWf, vWf: AgII, tPA and CRP were significantly higher in the patients with peripheral arterial occlusive disease than in the healthy individuals. No differences in marker protein plasma levels were found between individuals with, and those without hyperhomocysteinemia, apart from vWf, which was significantly raised in hyperhomocysteinemic as compared to normohomocysteinemic patients. We did not find any evidence for an independent association between hyperhomocysteinemia and protein markers of endothelial cell function in healthy subjects.
Asunto(s)
Arteriopatías Oclusivas/sangre , Factores de Coagulación Sanguínea/análisis , Endotelio Vascular/metabolismo , Homocisteína/sangre , Adulto , Antígenos/sangre , Biomarcadores/sangre , Femenino , Fibronectinas/sangre , Humanos , Masculino , Persona de Mediana Edad , Inhibidor 1 de Activador Plasminogénico/sangre , Factores de Riesgo , Trombomodulina/sangre , Activador de Tejido Plasminógeno/sangre , Factor de von Willebrand/análisisRESUMEN
PURPOSE: To test an expandable nitinol intraluminal stent for hoop strength, biocompatibility, corrosion resistance, and patency. MATERIALS AND METHODS: Forty-four stents were implanted in the iliac arteries of 22 sheep. Follow-up was performed with angiography and histologic examination for up to 6 months. RESULTS: All but one stent remained widely patent during the follow-up period. Two stents in two sheep were placed incorrectly early in the study; these sheep were not followed up. Hoop strength was found to be superior to that of a similar, commercially available, self-expanding stent. Minimal corrosion was seen at 6 months, and the stent appears to be biocompatible. The stent has good radiopacity and deploys with minimal foreshortening. CONCLUSION: The stent can be reliably and safely deployed in the vascular system. Clinical trials in humans are warranted.
Asunto(s)
Aleaciones , Arteria Ilíaca , Stents , Angiografía , Animales , Materiales Biocompatibles , Corrosión , Diseño de Equipo , Oclusión de Injerto Vascular/diagnóstico por imagen , Arteria Ilíaca/diagnóstico por imagen , Ovinos , Estrés Mecánico , Grado de Desobstrucción Vascular/fisiologíaRESUMEN
Preliminary results suggest that thermal balloon angioplasty (BA) may produce plaque welding, decreased elastic recoil, and increased luminal caliber. The authors report results of a simple method of thermal BA in a canine model. Seven mongrel dogs (15-25 kg) underwent conventional BA of each iliac artery with balloons that were 1-2 mm larger than the vessel lumen. The balloons were then perfused with a mixture of saline and contrast material at either 25 degrees C (control) or 100 degrees C for 1 minute. Compared with baseline measurements, thermal BA produced greater lumen enlargement (+16.7%) than control BA (+3.4%) immediately after the procedure (P less than .05). This trend persisted in vessels studied after a delay of 2, 4, or 12 weeks. Histologic sections from specimens studied after a delay demonstrated intimal hyperplasia in both the thermally treated and control arteries. Medial sclerosis was consistently seen in the thermally treated arteries. The authors conclude that thermal BA results in immediate and delayed increases in arterial diameter compared with conventional BA due to decreased elastic recoil and medial sclerosis.
Asunto(s)
Angioplastia de Balón/instrumentación , Animales , Perros , Estudios de Evaluación como AsuntoRESUMEN
The size of present rotational atherectomy devices is limited in part by a tendency to produce vessel torsion. The authors designed and investigated a large-bore rotational atherectomy device for peripheral atherectomy in a single pass without significant torsion. A plaque was retrieved from 36 of 40 cadaveric iliac arteries. The mean plaque size was 8.4 x 3.9 mm, and the average number retrieved per artery was two. Thirty of 34 severely calcified arteries were treated successfully. Effluent study revealed no distal embolization; however, six perforations and four dissections occurred. Preliminary results suggest that a cutting surface with a relatively large diameter can be designed to be effective without producing vessel torsion. Changes in future designs will include added flexibility and expandable cutting surfaces to enhance safety and minimize entry diameter.
Asunto(s)
Arteriosclerosis/cirugía , Diseño de Equipo , Estudios de Evaluación como Asunto , Humanos , Técnicas In Vitro , Enfermedades Vasculares Periféricas/cirugía , Instrumentos QuirúrgicosRESUMEN
A total of 100 radiopaque blood clots were injected into seven adult sheep under fluoroscopic observation to assess the clot-trapping efficiency of the Greenfield vena caval filter. Eleven percent of the clots passed through the filter, with all failures limited to the two smallest clot sizes: 4 x 10 mm (five of 25) and 4 x 30 mm (six of 25). The Greenfield filter was 100% efficient in trapping larger clots (8 x 10 mm and 8 x 30 mm). There was a tendency toward poorer clot-trapping performance when the Greenfield filter was tilted within the vena cava, but this was not significant. There were no significant differences in hemodynamic measurements obtained immediately before and after injection of each clot, and no significant changes were noted in the animal's hemodynamic status or in blood gas measurements in those cases in which the clots passed through the filter. Since the caval diameter in sheep approximates that in humans, the authors conclude that the Greenfield filter in the clinical setting is capable of stopping large, likely fatal, emboli and a large number of smaller, possibly less clinically significant, emboli.