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1.
Cochrane Database Syst Rev ; (1): CD003504, 2014 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-24399686

RESUMO

BACKGROUND: Interventional treatment of arteries that are narrowed and obstructed by atherosclerosis involves either bypassing the blockage using a graft; widening the artery from the inside with a balloon, a procedure known as percutaneous transluminal angioplasty (PTA); or providing a strut to hold the vessel open, known as a stent. All of these treatments are, however, limited by the high numbers that fail within a year. Intravascular brachytherapy is the application of radiation directly to the site of vessel narrowing. It is known to inhibit the processes that lead to restenosis (narrowing) of vessels and grafts after treatment. This is an update of a review first published in 2002. OBJECTIVES: To assess the efficacy of, and complications associated with, intravascular brachytherapy (IVBT) for maintaining patency after angioplasty or stent insertion in native vessels or bypass grafts of the iliac or infrainguinal arteries. SEARCH METHODS: For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched their Specialised Register (last searched August 2013) and CENTRAL (2013, Issue 7). SELECTION CRITERIA: Randomised controlled trials of the use of brachytherapy as an adjunct to the endovascular treatment of people with peripheral arterial disease (PAD) or stenosed bypass grafts of the iliac or infrainguinal arteries versus the procedure without brachytherapy. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and two other review authors independently extracted the data. Adverse event information was collected from the trials. MAIN RESULTS: Eight trials with a combined total of 1090 participants were included in this review. All included studies used the femoropopliteal artery. We did not identify any studies that used the iliac arteries. All studies compared PTA with or without stenting plus IVBT versus PTA with or without stenting alone. No trials were found comparing IVBT to technologies such as drug eluting stents or balloons, or cryoplasty. Follow-up ranged from six months to five years. The quality of the included trials was moderate with our concerns relating to the difficulty of blinding due to the nature of the procedures and the small sample sizes for some studies. Primary outcomes (patency or restenosis and need for re-intervention) were reported in the majority of the trials, but reporting at various time points and the use of multiple definitions of the outcomes by the included studies meant that not all data were available for pooling. The secondary outcomes were not reported in many of the included studies.For brachytherapy, cumulative patency was higher at 24 months (odds ratio (OR) 2.36, 95% confidence interval (CI) 1.36 to 4.10, n = 222, P = 0.002). A statistically significant difference was found for restenosis at six months (OR 0.27, 95% CI 0.11 to 0.66, n = 562, P = 0.004), 12 months (OR 0.44, 95% CI 0.28 to 0.68, n = 375, P = 0.0002) and 24 months (OR 0.41, 95% CI 0.21 to 0.78, n = 164, P = 0.007) in favour of IVBT. No difference was found after five years as measured in one study. The need for re-interventions was reported in six studies. Target lesion revascularisation was significantly reduced in trial participants treated with IVBT compared with angioplasty alone (OR 0.51, 95% CI 0.27 to 0.97, P = 0.04) at six months after the interventions. No statistically significant difference was found between the procedures on the need for re-intervention at 12 and 24 months after the procedures.A statistically significant lower number of occlusions was found in the control group at more than three months (OR 11.46, 95% CI 1.44 to 90.96, n = 363, P = 0.02) but no differences were found at less than one month nor at 12 months after the procedures making the clinical significance uncertain. Ankle brachial index was statistically significantly better for IVBT at the 12 month follow-up (mean difference 0.08, 95% CI 0.02 to 0.14, n = 100, P = 0.02) but no statistically significant differences were found at 24 hours and at six months.Quality of life, complications, limb loss, cardiovascular deaths, death from all causes, pain free walking distance and maximum walking distance on a treadmill were similar for the two arms of the trials with no statistically significant difference found between the treatment groups. AUTHORS' CONCLUSIONS: The evidence for using peripheral artery brachytherapy as an adjunct to percutaneous transluminal angioplasty to maintain patency and for the prevention of restenosis in people with peripheral vascular disease is limited, mainly due to the inconsistency of assessment and reporting of clinically relevant outcomes. More data are needed on clinically relevant outcomes such as health related quality of life (HRQOL) or limb salvage and longer-term outcomes, together with comparisons with other techniques such as drug eluting balloons and stents. Adequately powered randomised controlled trials, health economics and cost-effectiveness data are required before the procedure could be recommended for widespread use.


Assuntos
Braquiterapia/métodos , Procedimentos Endovasculares/métodos , Doenças Vasculares Periféricas/radioterapia , Angioplastia , Artéria Femoral , Humanos , Doenças Vasculares Periféricas/terapia , Artéria Poplítea , Qualidade de Vida , Radioterapia Adjuvante , Ensaios Clínicos Controlados Aleatórios como Assunto , Stents , Grau de Desobstrução Vascular
2.
Z Evid Fortbild Qual Gesundhwes ; 103(6): 331-40, 2009.
Artigo em Alemão | MEDLINE | ID: mdl-19839205

RESUMO

CONTEXT: Percutaneous transluminal angioplasties (PTA) using balloon dilatation with or without stenting are performed to treat peripheral arterial occlusive disease (PAOD). Intravascular brachytherapy (IB) after PTA promises to reduce the restenosis rates. The present article addresses questions concerning medical efficacy and cost-effectiveness of IB in PAOD patients. METHODS: A systematic literature search for randomized controlled studies evaluating IB in PAOD was conducted in August 2007. Information synthesis was conducted using meta-analysis. Health economic modelling was performed on the basis of clinical assumptions derived from the meta-analysis and economical assumptions derived from the German Diagnosis Related Groups (G-DRG) 2007. RESULTS: Twelve publications covering seven studies about IB vs. no IB were included in the evaluation. IB after successful balloon dilatation showed a significant reduction in the rate of restenosis at six and/or twelve months (relative risk 0.62; 95% confidence interval: 0.46 to 0.84) and a significant delay in the time to recurrence of restenosis (17.5 vs. 7.4 months, p < 0.01). IB after stenting did not lead to significant results regarding the restenosis rates, but was more often associated with early and late occlusive thromboses. The incremental cost-effectiveness ratio per restenosis avoided for IB vs. no IB after successful balloon dilatation was--depending on the G-DRG used-Euro 8,484 and Euro 9,058, respectively. In the comparison of IB vs. no IB after stenting IB was demonstrated to be inferior to no IB. CONCLUSIONS: IB after successful balloon dilatation in PAOD can be recommended from a medical point of view. From the health economic perspective the answer is not yet clear. IB after stenting in PAOD cannot be recommended.


Assuntos
Angioplastia Coronária com Balão/métodos , Arteriopatias Oclusivas/radioterapia , Braquiterapia/métodos , Doenças Vasculares Periféricas/radioterapia , Angioplastia Coronária com Balão/economia , Arteriopatias Oclusivas/economia , Braquiterapia/economia , Terapia Combinada/economia , Humanos , Doenças Vasculares Periféricas/economia , Prevenção Secundária , Stents/economia
3.
Cardiovasc Revasc Med ; 10(3): 162-5, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19595397

RESUMO

BACKGROUND: Recurrent disease (restenosis) after endovascular treatment of the superficial femoral artery (SFA) remains a major problem. We evaluated the efficacy of beta-endovascular brachytherapy using the CORONA centering catheter in patients with SFA restenosis in a single-arm Phase II trial. METHODS AND RESULTS: A total of 28 patients (mean age 70 years; 16 female, 12 male) with recurrent SFA stenosis were treated, and in-stent restenosis was present in 17 patients (61%). Brachytherapy was performed with strontium-90 beta source using a 7-French CO(2)-filled one-segment centering catheter. New stents had to be applied in two cases. Mean interventional length was 129 mm (range 20-240 mm). A dose of 14 Gy in vessel radius (postinterventional) plus 2 mm was applied in 24 patients and 18.4 Gy in four patients. Treatment time was 7 min 32 s per radiation segment. No major adverse events occurred. Patients were followed by ankle-brachial index and duplex sonography for a median of 42 months. Cumulative restenosis rates at 1, 2, and 3 years were 9%, 28%, and 40%, respectively. Target vessel revascularization was performed in seven cases (25%). CONCLUSIONS: In comparison to literature data, the treatment of SFA restenosis with beta brachytherapy may improve long-term patency.


Assuntos
Angioplastia com Balão , Braquiterapia/instrumentação , Cateterismo Periférico/instrumentação , Artéria Femoral , Doenças Vasculares Periféricas/terapia , Artéria Poplítea , Radioisótopos de Estrôncio/uso terapêutico , Idoso , Angioplastia com Balão/instrumentação , Dióxido de Carbono , Constrição Patológica , Desenho de Equipamento , Feminino , Artéria Femoral/fisiopatologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Doenças Vasculares Periféricas/fisiopatologia , Doenças Vasculares Periféricas/radioterapia , Inibidores da Agregação Plaquetária/uso terapêutico , Artéria Poplítea/fisiopatologia , Estudos Prospectivos , Doses de Radiação , Recidiva , Stents , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular
4.
Cardiovasc Intervent Radiol ; 31(4): 698-708, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18185955

RESUMO

This report presents a review of the literature on endovascular brachytherapy (EVBT) after percutaneous transluminal angioplasty (PTA) in the femoropopliteal segment. We summarize the pathophysiological changes induced by PTA and EVBT within the vessel wall, technical considerations regarding various radiation sources and their application, the impact of stents on the radial dose profile, recommendations for dosimetry of beta and gamma sources, results of experimental and clinical trials, and the medication required before, during, and after EVBT. We aim to help to identify patients who are eligible for EVBT, to choose an appropriate technical approach, and to initiate adequate antiplatelet and anticoagulant therapy.


Assuntos
Angioplastia com Balão/efeitos adversos , Arteriopatias Oclusivas/radioterapia , Braquiterapia/métodos , Doenças Vasculares Periféricas/radioterapia , Radiografia Intervencionista/métodos , Angioplastia com Balão/métodos , Arteriopatias Oclusivas/diagnóstico por imagem , Arteriopatias Oclusivas/terapia , Feminino , Artéria Femoral/efeitos da radiação , Humanos , Radioisótopos de Irídio/uso terapêutico , Masculino , Doenças Vasculares Periféricas/diagnóstico por imagem , Doenças Vasculares Periféricas/terapia , Artéria Poplítea/efeitos da radiação , Prognóstico , Ensaios Clínicos Controlados Aleatórios como Assunto , Recidiva , Retratamento , Medição de Risco , Sensibilidade e Especificidade , Resultado do Tratamento , Grau de Desobstrução Vascular
5.
J Endovasc Ther ; 12(6): 723-30, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16363902

RESUMO

PURPOSE: To determine if the short-term efficacy of adjunctive endovascular brachytherapy (EVBT) is maintained over time in patients undergoing balloon angioplasty (BA) of femoropopliteal atherosclerotic lesions. METHODS: To evaluate the long-term clinical and angiographic outcome of EVBT, 147 consecutive patients (82 men; mean age 70.8+/-8.5 years) with 147 treated limbs were randomized to BA with (n=72, 49%) or without (n=75, 51%) adjunctive EVBT (12 or 14-Gy from an (192)Ir source, no centering, a 5-mm reference depth). Sixty-eight (46%) limbs were treated for de novo and 79 (54%) for recurrent femoropopliteal lesions. Clinical follow-up at 1, 3, 6, and 12 months and annually thereafter included evaluation of symptoms, ankle-brachial index (ABI), and intra-arterial angiography for new/worsening symptoms or at follow-up between 2 and 5 years. Sustained clinical success was defined as improvement in ABI >or=0.1 and/or of symptoms without repeated target lesion revascularization. Angiographic restenosis was defined as >or=50% diameter reduction. Subgroup analysis was performed for de novo versus recurrent lesions. RESULTS: Mean clinical follow-up was 32.3+/-21.5 months. Angiographic follow-up was available in 83 (56%) patients (41 BA and 42 BA+EVBT) at a mean 31.8+/-20.7 months. Cumulative sustained clinical success rates at 1, 2, and 3 years, respectively, were 84.3%, 82.1%, and 76.4% after BA versus 82.4%, 69.8%, and 67.5% after BA+EVBT (p=0.26 by log-rank). Although the proportion of patients undergoing follow-up angiography was moderate, the freedom from angiographic restenosis at 1, 2, and 3 years was 70.7%, 63.1%, and 47.1% after BA versus 82.7%, 64.3%, and 64.3% after BA+EVBT (p=0.16 by log-rank). No differences were found between BA and BA+EVBT outcomes in patients with de novo versus recurrent femoropopliteal lesions. CONCLUSION: The seemingly beneficial short-term effects of BA+EVBT are not sustained in the longer term, with no robust clinical improvement after angioplasty of atherosclerotic de novo or recurrent femoropopliteal lesions at up to 5 years.


Assuntos
Arteriopatias Oclusivas/radioterapia , Braquiterapia/métodos , Doenças Vasculares Periféricas/radioterapia , Idoso , Angiografia , Angioplastia com Balão , Arteriopatias Oclusivas/cirurgia , Terapia Combinada , Feminino , Artéria Femoral , Seguimentos , Humanos , Masculino , Doenças Vasculares Periféricas/cirurgia , Artéria Poplítea , Modelos de Riscos Proporcionais , Recidiva , Estatísticas não Paramétricas , Resultado do Tratamento , Grau de Desobstrução Vascular
6.
Cardiovasc Revasc Med ; 6(2): 75-81, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16263364

RESUMO

We describe a case of instent restenosis in a femoral-distal saphenous vein bypass graft successfully treated with brachytherapy. A 45-year-old insulin-requiring diabetic woman underwent an in-situ femoral-anterior tibial bypass graft for a non-healing ischemic ulcer. Despite a technically successful percutaneous transluminal angioplasty and endovascular stenting of a retained valve within the threatened graft, the wound failed to heal. At the 1-month follow-up, instent restenosis was documented and successful cutting balloon angioplasty, complemented by adjunctive beta-irradiation was successfully performed. Clinical and hemodynamic success was achieved, with prompt ulcer healing and intermediate-term graft patency maintained on surveillance duplex ultrasound follow-up. We review the literature on radiation therapy in the management of peripheral arterial disease and discuss therapeutic options in the management of restenosis.


Assuntos
Angioplastia com Balão/métodos , Braquiterapia/métodos , Oclusão de Enxerto Vascular/radioterapia , Doenças Vasculares Periféricas/radioterapia , Veia Safena/transplante , Stents , Partículas beta/uso terapêutico , Diabetes Mellitus Tipo 2/complicações , Pé Diabético/etiologia , Pé Diabético/terapia , Feminino , Oclusão de Enxerto Vascular/etiologia , Humanos , Pessoa de Meia-Idade , Doenças Vasculares Periféricas/diagnóstico por imagem , Doenças Vasculares Periféricas/cirurgia , Artéria Poplítea/diagnóstico por imagem , Artéria Poplítea/cirurgia , Radiografia , Radioterapia Adjuvante , Veia Safena/diagnóstico por imagem , Stents/efeitos adversos , Artérias da Tíbia/diagnóstico por imagem , Artérias da Tíbia/cirurgia , Resultado do Tratamento , Ultrassonografia Doppler Dupla/métodos , Grau de Desobstrução Vascular
7.
Circulation ; 111(24): 3310-5, 2005 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-15956130

RESUMO

BACKGROUND: Femoropopliteal percutaneous transluminal angioplasty (PTA) remains limited by restenosis. Although vascular brachytherapy may be effective in reducing restenosis, external beam radiation would be more practical to administer after PTA. METHODS AND RESULTS: After femoropopliteal PTA without stent placement, 99 patients were randomly assigned to 0 Gy (placebo; n=24), 7 Gy (n=24), 10.5 Gy (n=26), or 14 Gy (n=25) of external beam radiation of the PTA site (with a 3-cm margin at both extremities) in 1 session 24 hours after PTA. The primary end point was minimum lumen diameter on quantitative angiography 1 year after PTA. One year after PTA, the mean minimum lumen diameter was 1.92, 1.64, 1.92, and 2.91 mm, respectively, for the 0-, 7-, 10.5-, and 14-Gy groups (P=0.0072 for 0 versus 14 Gy). Mean luminal loss was 1.14, 1.27, 1.08, and 0.14 mm, respectively, for the 4 groups (P=0.0072 for 0 versus 14 Gy). Restenosis >50% was present in 50%, 65%, 48%, and 25% of patients, respectively, for the 0-, 7-, 10.5-, and 14-Gy groups (P=0.072). At 18 months, repeated revascularizations were required in 25% of patients in the 0-Gy group versus 12% of patients in the 14-Gy group (P=0.24). CONCLUSIONS: A single session of external beam radiation of 14 Gy of the femoropopliteal angioplasty site significantly reduces restenosis at 1 year.


Assuntos
Angioplastia com Balão/efeitos adversos , Constrição Patológica/prevenção & controle , Doenças Vasculares Periféricas/radioterapia , Radioterapia/métodos , Idoso , Angiografia , Relação Dose-Resposta à Radiação , Feminino , Artéria Femoral/patologia , Seguimentos , Humanos , Claudicação Intermitente , Masculino , Pessoa de Meia-Idade , Doenças Vasculares Periféricas/complicações , Doenças Vasculares Periféricas/terapia , Artéria Poplítea/patologia , Resultado do Tratamento
8.
Catheter Cardiovasc Interv ; 65(3): 412-5, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15812808

RESUMO

For years, intra-arterial brachytherapy has been a recognized method for treating recurrent stenosis after percutaneous transluminal angioplasty and stent placement. However, its use in arteries supplying the brain has not been described to date. We report a case treated with intra-arterial brachytherapy for high-grade recurrent stenoses of the high cervical internal carotid artery and the proximal vertebral artery. At 2-year follow-up, the outcome was successful.


Assuntos
Braquiterapia/métodos , Estenose das Carótidas/radioterapia , Insuficiência Vertebrobasilar/radioterapia , Idoso , Angioplastia com Balão/efeitos adversos , Implante de Prótese Vascular/efeitos adversos , Estenose das Carótidas/etiologia , Estenose das Carótidas/terapia , Humanos , Masculino , Doenças Vasculares Periféricas/etiologia , Doenças Vasculares Periféricas/radioterapia , Doenças Vasculares Periféricas/terapia , Recidiva , Reoperação , Stents/efeitos adversos , Insuficiência Vertebrobasilar/etiologia , Insuficiência Vertebrobasilar/terapia
9.
Radiother Oncol ; 74(1): 11-6, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15683662

RESUMO

BACKGROUND AND PURPOSE: To evaluate the feasibility and efficacy of external beam irradiation (EBI) for the prevention of re-stenosis due to neointimal hyperplasia, after percutaneous transluminal angioplasty (PTA) and stent placement of the superficial femoral artery. PATIENTS AND METHODS: A total of 60 patients with the diagnosis of superficial femoral artery stenoses or occlusions due to peripheral arterial obstructive disease underwent PTA and implantation of a self-expandable stent at their superficial femoral artery. After the procedure, patients were randomised and 30 of them received EBI (6 MV photons, total dose 24 Gy in six fractions in 2 weeks), while the rest 30 received no radiation therapy. RESULTS: EBI was technically feasible in all patients, without serious radiation related side effects. Overall, a statistically significant difference was observed in stenosis categories between the two groups at 6 months follow-up (P=0.04). More specifically, significantly more patients in the control group presented with stenosis greater or equal than 70% [EBI group 30% (9/30); control group 66.7% (20/30); P=0.009]. This difference in the percentage of re-stenosis had as a consequence significantly lower re-intervention rates among the patients of the irradiated group [17% (5/30) versus 47% (14/30); P=0.025] during the 6 months follow-up period. We also observed that the irradiated patients had re-stenosis at the stent ends, while the non-irradiated had re-stenosis at the stent ends and the lumen. Three of the irradiated patients, who discontinued the anti-platelet treatment, have shown thrombosis of the irradiated artery during the first month from the completion of the treatment. CONCLUSIONS: It is our belief that EBI is a feasible, safe and effective method for the prevention of neointimal hyperplasia at the superficial femoral artery. Further studies are deemed necessary to optimise the radiotherapy schedule.


Assuntos
Angioplastia com Balão/efeitos adversos , Artéria Femoral/patologia , Oclusão de Enxerto Vascular/prevenção & controle , Oclusão de Enxerto Vascular/radioterapia , Doenças Vasculares Periféricas/radioterapia , Doenças Vasculares Periféricas/terapia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Hiperplasia/prevenção & controle , Hiperplasia/radioterapia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Lesões por Radiação , Stents , Resultado do Tratamento , Túnica Íntima/patologia
10.
Int J Radiat Oncol Biol Phys ; 60(5): 1652-9, 2004 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-15590198

RESUMO

PURPOSE: To determine dosimetric parameters, such as radial and longitudinal dose profiles, for beta and gamma devices in peripheral endovascular brachytherapy. METHODS AND MATERIALS: An (192)Ir high-dose rate stepping source, a (90)Sr source train, and a (32)P-coated radiation balloon were investigated. The treatment-planning software PLATO, Monte Carlo code EGSnrc, and GafChromic film dosimetry were used to analyze the dose distribution of these devices. RESULTS: For a 5-mm-diameter vessel, the ratio between the dose at 2 mm depth and the dose at the lumen surface was 1.8, 3.4, and 16.2 for the (192)Ir, (90)Sr, and (32)P devices, respectively. The dose variation at the reference depth of 2 mm into the vessel wall was 7-18 Gy, for different analyzed dose prescriptions. The reference lumen dose was different by a factor >8. For all three devices, the reference isodose length was not <5 mm on the proximal and distal edge of the active source length. CONCLUSIONS: A complete set of dose parameters for beta and gamma sources has to be considered for appropriate treatment planning and performance, including reporting of reference depth dose, reference lumen dose, and reference isodose length.


Assuntos
Braquiterapia/métodos , Doenças Vasculares Periféricas/radioterapia , Artérias , Dosimetria Fotográfica , Radioisótopos de Irídio/uso terapêutico , Radioisótopos de Fósforo/uso terapêutico , Doses de Radiação , Radioisótopos de Estrôncio/uso terapêutico
11.
Am J Cardiovasc Drugs ; 4(6): 385-94, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15554724

RESUMO

Intravascular brachytherapy has become the standard of care for the treatment of coronary in-stent restenosis after repeat angioplasty. More than 5000 patients have been treated as part of various clinical trials. Based on the results of the GAMMA I trial, the START ((90)Sr Treatment of Angiographic Restenosis Trial), and the INHIBIT (INtimal Hyperplasia Inhibition with Beta In-stent restenosis Trial), the Checkmate system using (192)Ir, the Betacath system using (90)Sr/Y, and the Galileo system using (32)P, have been approved for the treatment of in-stent restenosis. With a better understanding and application of radiation oncology concepts to vascular brachytherapy, problems such as edge failure are being overcome. The complication of late thrombosis has also become less significant with the elimination of restenting at the brachytherapy procedure, and the prolonged use of antiplatelet therapy. There are other competing modalities in the early phases of clinical trials. The durability of results, lack of any significant long-term complications and the confirmation of the efficacy in other sites will further consolidate the role of radiation in treating in-stent restenosis.


Assuntos
Braquiterapia/efeitos adversos , Braquiterapia/métodos , Estenose Coronária/radioterapia , Doenças Vasculares Periféricas/radioterapia , Stents , Partículas beta , Reestenose Coronária/etiologia , Reestenose Coronária/prevenção & controle , Reestenose Coronária/radioterapia , Raios gama , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Stents/efeitos adversos , Trombose/etiologia
12.
Int J Radiat Oncol Biol Phys ; 59(3): 815-21, 2004 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-15183485

RESUMO

PURPOSE: Early restenosis is one of the major complications after successful percutaneous transluminal angioplasty (PTA), in main, as well as peripheral, arteries. The effectiveness of hypofractionated external beam radiotherapy (EBRT) as a prophylaxis for restenosis was examined in a prospective, randomized, double-blind, clinical trial. METHODS AND MATERIALS: Forty-eight patients underwent sham RT and 47 were treated with daily RT in 3-Gy fractions, to a total dose of 21 Gy. The follow-up lasted for 12 months, and the examinations included pressure measurements and calculations of the ankle-brachial index or duplex sonography ("peak velocity ratio"). If restenosis was suspected, additional angiography was performed. RESULTS: No statistically significant difference was found between the treatment groups: sham RT 16 failures (33.3%) and EBRT group 21 failures (45.7%; p = 0.292). EBRT also showed no substantial effects on subgroups classified by the specific length of the lesion or in diabetic patients. CONCLUSION: External beam radiotherapy does not prevent restenosis. A reduction in the failure rate >8% using fractionated EBRT with doses aimed at keloid prevention can be ruled out with a probability of 97.5%. Endovascular brachytherapy remains the preferred therapeutic method for achieving restenosis prophylaxis through RT.


Assuntos
Angioplastia com Balão , Doenças Vasculares Periféricas/prevenção & controle , Idoso , Constrição Patológica/prevenção & controle , Constrição Patológica/radioterapia , Método Duplo-Cego , Feminino , Artéria Femoral , Humanos , Artéria Ilíaca , Masculino , Doenças Vasculares Periféricas/radioterapia , Doenças Vasculares Periféricas/terapia , Artéria Poplítea , Estudos Prospectivos , Prevenção Secundária
13.
Khirurgiia (Mosk) ; (4): 14-9, 2003.
Artigo em Russo | MEDLINE | ID: mdl-12744128

RESUMO

Seventy-one subjects entered this study. The control group consisted of 12 healthy subjects, the comparative group included 15 patients who received standard therapy of vascular diseases but without physiotherapy. The study group consisted of 44 patients whose treatment was supplemented with laser irradiation. Angiography, ultrasonic dopplerography, laser flowmetry, oxygenometry were applied for control of treatment efficacy. Regional ischemia was evaluated with detection of pO2 of foot. LT increased oxygenation of foot soft tissues in patients with low primary pO2 and decreased in ones with higher. As a result the number of patients with low pO2 (0 < pO2 < 20) decreased from 13.7 to 4.5%, with middle pO2 (20 < pO2 < 40) increased from 27.3 to 50.0%, with high pO2 (pO2 = 40) decreased from 59.0 to 45.5%. Redistribution in favor of 20 < pO2 < 40 is regarded as normalizing effect of LT. It is concluded that LT increases oxygenation of foot soft tissues in patients with low primary pO2 and decreased in ones with higher.


Assuntos
Arteriosclerose Obliterante/fisiopatologia , Arteriosclerose Obliterante/radioterapia , Terapia com Luz de Baixa Intensidade , Extremidade Inferior/irrigação sanguínea , Doenças Vasculares Periféricas/fisiopatologia , Doenças Vasculares Periféricas/radioterapia , Arteriosclerose Obliterante/tratamento farmacológico , Terapia Combinada , Humanos , Extremidade Inferior/fisiopatologia , Microcirculação , Doenças Vasculares Periféricas/tratamento farmacológico , Resultado do Tratamento
14.
J Am Coll Cardiol ; 41(3): 409-12, 2003 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-12575967

RESUMO

OBJECTIVES: The aim of this article is to underline the importance of this complication after endovascular brachytherapy (EVBT) and intravascular stenting of the femoropopliteal arteries occurring in a running randomized trial. BACKGROUND: Endovascular brachytherapy has been proposed as a promising treatment modality to reduce restenosis after angioplasty. However, the phenomenon of late acute thrombotic occlusion (LATO) in patients receiving EVBT after stenting is of major concern. METHODS: In an ongoing prospective multicenter trial, patients were randomized to undergo EVBT (iridium 192; 14 Gy at a depth of the radius of the vessel +2 mm) after percutaneous recanalization of femoropopliteal obstructions. Of the 204 patients who completed the six months follow-up, 94 were randomized to EVBT. RESULTS: Late acute thrombotic occlusion occurred exclusively in 6 of 22 patients (27%) receiving EVBT after intravascular stenting and always in concomitance with reduction of antithrombotic drug prevention (clopidogrel). Conversely, none of the 13 patients with stents and without EVBT (0%; p < 0.05) and none of the 72 patients (0%; p < 0.01) undergoing EVBT after simple balloon angioplasty presented LATO. CONCLUSIONS: Late thrombotic occlusion occurs not only in patients undergoing EVBT after percutaneous coronary recanalization but also after stenting of the femoropopliteal arteries and may compromise the benefits of endovascular radiation. The fact that all our cases with LATO occurred concomitantly with stopping clopidogrel may indicate a possible rebound mechanism. An intensive and prolonged antithrombotic prevention is probably indicated in these patients.


Assuntos
Arteriopatias Oclusivas/etiologia , Implante de Prótese Vascular/efeitos adversos , Braquiterapia/efeitos adversos , Artéria Femoral/efeitos da radiação , Artéria Femoral/cirurgia , Doenças Vasculares Periféricas/radioterapia , Doenças Vasculares Periféricas/cirurgia , Artéria Poplítea/efeitos da radiação , Artéria Poplítea/cirurgia , Complicações Pós-Operatórias , Stents/efeitos adversos , Trombose/etiologia , Doença Aguda , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo
15.
Rev Cardiovasc Med ; 3 Suppl 5: S23-30, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12478232

RESUMO

Vascular brachytherapy using beta and gamma emitters has revolutionized treatment of in-stent restenosis. We are witnessing a near-abolition of the restenosis problem for simple lesions, but the future of vascular brachytherapy depends on our success in improving efficacy and reducing complications such as late thrombosis and edge effects. Optimizing dosimetry, applying adequate radiation margins, and prolonging antiplatelet therapy should equalize brachytherapy results with those of drug-eluting stents. In this overview we examine issues related to progress and optimization of outcomes derived from the use of vascular brachytherapy. We also examine its potential to expand to other applications beyond in-stent restenosis, such as the treatment of de novo lesions and peripheral vascular disease


Assuntos
Braquiterapia/instrumentação , Doença das Coronárias/radioterapia , Sistemas de Liberação de Medicamentos , Stents , Angioplastia Coronária com Balão/instrumentação , Reestenose Coronária/radioterapia , Trombose Coronária/etiologia , Humanos , Avaliação de Resultados em Cuidados de Saúde , Doenças Vasculares Periféricas/radioterapia , Stents/efeitos adversos
16.
Eur J Vasc Endovasc Surg ; 24(5): 377-82, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12435336

RESUMO

INTRODUCTION: Intravascular brachytherapy (IVBT) utilises the percutaneous insertion of a radioactive source to inhibit myointimal hyperplasia in arteries treated by balloon angioplasty or stenting. A systematic review was performed of trials of IVBT in patients with Peripheral Arterial Disease (PAD). METHODS: Search strategy - the reviewers searched Medline, Embase, the Cochrane Peripheral Vascular Diseases Group trials register, DARE, CCT and NHS EED for clinical studies and trials of adjuvant IVBT in PAD. Two reviewers assessed trial quality independently. RESULTS: Fourteen clinical trials were identified by the search, representing five clinical studies (all allocated D for not randomised) and one randomised controlled trial (allocated A). The randomised trial showed a benefit for IVBT compared with placebo (OR 0.35, 95% CI 0.24-0.53). In the non-randomised studies, 12 month cumulative patency rates ranged from 60-87%. There were few technical complications. In the only report involving IVBT and routine concurrent stent insertion acute thrombosis occurred in 7 (21%) of patients. CONCLUSION: Early reports have confirmed the safety and technical feasibility of IVBT. However, follow-up is too short at present to assess the durability and long-term complications of this new therapeutic option.


Assuntos
Arteriopatias Oclusivas/radioterapia , Braquiterapia/métodos , Doenças Vasculares Periféricas/radioterapia , Angioplastia com Balão , Arteriopatias Oclusivas/patologia , Arteriopatias Oclusivas/terapia , Humanos , Hiperplasia/radioterapia , Doenças Vasculares Periféricas/patologia , Doenças Vasculares Periféricas/terapia , Recidiva , Stents , Túnica Íntima/patologia
19.
Med Phys ; 29(8): 1678-86, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12201413

RESUMO

High dose rate (HDR) 192Ir sources are currently used in intravascular brachytherapy (IVB) for the peripheral arterial system. This poses a demand on evaluating accurate dose parameters in the near-source region for such sources. The purpose of this work is to calculate the dose parameters for the old VariSource HDR 192Ir source and the new microSelectron HDR 192Ir source, using Monte Carlo electron and photon transport simulation. The two-dimensional (2D) dose rate distributions and the air kerma strengths for the two HDR sources were calculated by EGSnrc and EGS4 Monte Carlo codes. Based on these data, the dose parameters proposed in the AAPM TG-60 protocol were derived. The dose rate constants obtained are 13.119+/-0.028 cGy h(-1) U(-1) for the old VariSource source, and 22.751+/-0.031 cGy h(-1) U(-1) for the new microSelectron source at the reference point (r0 = 2 mm, theta = pi/2). The 2D dose rate distributions, the radial dose functions, and the anisotropy functions presented for the two sources cover radial distances ranging from 0.5 to 10 mm. In the near-source region on the transverse plane, the dose effects of the charged particle nonequilibrium and the beta-particle dose contribution were studied. It is found that at radial distances ranging from 0.5 to 2 mm, these effects increase the calculated dose rates by up to 29% for the old VariSource source, and by up to 12% for the new microSelectron source, which, in turn, change values of the radial dose function and the anisotropy function. The present dose parameters, which account for the charged particle nonequilibrium and the beta particle contribution, may be used for accurate IVB dose calculation.


Assuntos
Braquiterapia/instrumentação , Braquiterapia/métodos , Radioisótopos de Irídio/uso terapêutico , Doenças Vasculares Periféricas/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Simulação por Computador , Humanos , Método de Monte Carlo , Dosagem Radioterapêutica
20.
J Vasc Surg ; 35(5): 1041-7, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12021726

RESUMO

Ongoing advances in peripheral endovascular technology have been met with disappointing results because of restenosis within the treated vessel. In particular, stent balloon angioplasty of peripheral vessels has yet to achieve patency rates that approximate conventional treatment in the long term. Recent advances in stent, balloon, and wire construction include the incorporation of radioactive substances in an attempt to ameliorate the inflammatory response provoked by typical endovascular manipulation, a technique termed vascular brachytherapy. gamma- and beta-isotopes and external beam radiation target the very cell population whose activity results in the development of neointimal hyperplasia. Although most clinical research examining the efficacy of vascular brachytherapy has emerged from the coronary artery literature, the use of vascular brachytherapy also has been examined in the peripheral arterial tree and has shown promising results. Current data indicate that vascular brachytherapy is a safe and accessible adjunctive endovascular maneuver that may improve the short-term patency rate of peripheral endovascular applications. The effects on long-term patency rates remain indeterminate compared to conventional therapy.


Assuntos
Braquiterapia , Doenças Vasculares Periféricas/radioterapia , Humanos , Doenças Vasculares Periféricas/fisiopatologia , Grau de Desobstrução Vascular/fisiologia , Grau de Desobstrução Vascular/efeitos da radiação
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