Relevance of a skilled vascular surgeon and optimized facility practices in the long-term patency of arteriovenous fistulas: a prospective study / Relevância de um cirurgião vascular qualificado e práticas hospitalares otimizadas na patência a longo prazo das fístulas arteriovenosas: um estudo prospectivo

Abstract Introduction: Arteriovenous fistulas (AVF) are the best hemodialysis vascular accesses, but their failure rate remains high. Few studies have addressed the role of the vascular surgeon's skills and the facility's practices. We aimed to study these factors, with the hypothesis that the surgeon's skills and facility practices would have an important role in primary failure and patency rates at 12 months, respectively. Methods: This was a single-center, prospective cohort study carried out from March 2005 to March 2017. Only incident patients were included. A single surgeon made all AVFs, either in the forearm (lower) or the elbow (upper). Vascular access definitions were in accordance with the North American Vascular Access Consortium. Results: We studied 113 AVFs (65% lower) from 106 patients (39% diabetics, 58% started with catheter). Time to first connection was 21.5 days (IR: 14 - 31). Only 14 AVFs (12.4%) underwent primary failure and 18 failed during the first year. Functional primary patency rate was 80.9% (SE 4.1) whereas primary unassisted patency rate, which included PF, was 70.6% (4.4). Logistic regression showed that diabetes (OR = 3.3, 95%CI 1.38 - 7.88, p = .007) and forearm location (OR = 3.03, 95CI% 1.05 - 8.76, p = 0.04) were predictors of AVF failure. Patency of lower and upper AVFs was similar in non-diabetics, while patency in diabetics with lower AVFs was under 50%. (p = 0.003). Conclusions: Results suggest that a long-lasting, suitable AVF is feasible in almost all patients. The surgeon's skills and facility practices can have an important role in the long term outcome of AVF.

Resumo Introdução: Fístulas arteriovenosas (FAV) são os melhores acessos vasculares para hemodiálise, mas sua taxa de falhas permanece alta. Poucos estudos abordaram o papel das habilidades do cirurgião vascular e das práticas hospitalares. Nosso objetivo foi avaliar esses fatores, com a hipótese de que as habilidades do cirurgião e as práticas hospitalares teriam um papel importante nas taxas de falhas primárias e perviedade em 12 meses, respectivamente. Métodos: Este foi um estudo de coorte prospectivo de um único centro, realizado de março de 2005 a março de 2017. Apenas os pacientes incidentes foram incluídos. Um único cirurgião fez todas as FAVs, seja no antebraço (inferior) ou no cotovelo (superior). As definições de acesso vascular estavam de acordo com o Consórcio Norte-Americano de Acesso Vascular. Resultados: Estudamos 113 FAVs (65% inferiores) de 106 pacientes (39% diabéticos, 58% começaram com cateter). O tempo até a primeira conexão foi de 21,5 dias (RI: 14 - 31). Apenas 14 FAV (12,4%) tiveram falha primária e 18 falharam durante o primeiro ano. A taxa de patência funcional primária foi de 80,9% (SE 4,1), enquanto a taxa de permeabilidade primária não assistida, que incluiu FP, foi de 70,6% (4,4). A regressão logística mostrou que o diabetes (OR = 3,3, 95% IC 1,38 - 7,88, p = 0,007) e localização no antebraço (OR = 3,03, 95% IC 1,05 - 8,76, p = 0,04) foram preditores de falha da FAV. A patência das FAVs inferior e superior foi semelhante em não-diabéticos, enquanto a perviedade em diabéticos com FAV inferior foi menor que 50%. (p = 0,003). Conclusões: Nossos resultados sugerem que uma FAV duradoura e adequada é viável em quase todos os pacientes. As habilidades do cirurgião e das práticas hospitalares podem ter um papel importante no resultado a longo prazo da FAV.

Translumbar hemodialysis long-term catheters: an alternative for vascular access failure / Cateter translombar para hemodiálise: uma alternativa para falência de acesso vascular

Abstract Introduction: Vascular access (VA) in hemodialysis (HD) is essential to end-stage renal disease (ESRD) patients survival. Unfortunately, after some years in HD program, a significant number of patients may develop VA failure for many reasons. In this situation, arterial venous fistula (AVF) confection or catheters placement in traditional vascular sites (jugular, femoral or subclavian) are not feasible. In this scenario, translumbar tunneled dialysis catheter (TLDC) may be a salvage option. Objectives: To describe placement technic, complications, and patency of 12 TLDC. Methods: A retrospective study was performed to analyze 12 TLDC placement in an angiography suite using fluoroscopic guidance at the University Hospital of the Rio Grande do Norte Federal University from January 2016 to October 2017. The data collected of the total procedures performed consisted of demographic characteristics, success rates, observed complications, patient survival, and catheter patency. Results: All 12 TLDC were placed with success; there were only 2 significant periprocedure complications (major bleeding and extubation failure); 41.6% of patients presented a catheter-related first infection after 98 ± 72.1 (6-201) days, but catheter withdrawal was not necessary, mean total access patency was 315.5 (range 65 - 631) catheter-days, and catheter patency at 3, 6 and 12 months was 91 %, 75%, and 45%. Conclusion: TLDC is an option for patients with VA failure, improving survival and acting as a bridge for renal transplantation.

Resumo Introdução: O acesso vascular (AV) para hemodiálise (HD) é crucial para os pacientes portadores de doença renal crônica (DRC) estágio V. Infelizmente, com o passar dos anos, um percentual não desprezível desses enfermos evolui para falência de AV por diversos motivos, o que impossibilita a confecção de novas fístulas arteriovenosas (FAV) ou o implante de cateteres venosos centrais nos sítios de punções tradicionais. Nesse cenário, o implante de cateteres translombares para hemodiálise (CTLHD) em veia cava inferior ganha destaque como medida salvadora. Objetivos: Relatar uma série de 12 casos de implante de CTLHD, sua técnica de implante, patência e complicações. Métodos: Estudo retrospectivo que analisou 12 implantes de CTLHD por radiologista intervencionista no setor de hemodinâmica do Hospital Universitário da Universidade Federal do Rio Grande do Norte (UFRN), no período de janeiro/2016 a outubro/2017. Os dados coletados consistiram em: características demográficas da população estudada, taxa de sucesso, complicações observadas, sobrevida dos pacientes, patência do cateter e desfechos clínicos. Resultados: Todos os 12 CTLHD foram implantados e utilizados com sucesso; ocorreram apenas 2 complicações associadas ao procedimento (sangramento e falha na extubação); 41,6% dos pacientes apresentaram infecção relacionada ao cateter após 98 ± 72,1 dias (6-201 dias), mas não houve necessidade de remoção; e a patência foi de 315,5 cateteres-dia (65-631 dias). Conclusão: O CTLHD é uma opção para pacientes com falência de acesso vascular, prolongando a sobrevida dos pacientes e atuando como ponte para o transplante renal.

Surgical aspects of no-touch saphenous vein graft harvesting in cabg: clinical and angiographic follow-up at 3 months

Abstract With more than 800,000 coronary artery bypass grafting (CABG) operations annually worldwide and the saphenous vein being the most common conduit used, there is no question that improving saphenous vein graft patency is one of the most important tasks in CABG. This video describes the no-touch harvesting procedure of the saphenous vein on an 80-year old man with hypertension, hyperlipidemia and a previous myocardial infarction with percutaneous coronary intervention to the right coronary artery. He was complaining of exertional chest pain and was diagnosed with stable angina pectoris. The coronary angiography showed advanced three vessel disease with significant stenoses in the left anterior descending (LAD) artery, two marginal arteries (MAs) and the posterior descending artery (PDA), in addition to an occluded diagonal artery (DA). The patient received a triple sequential no-touch vein graft to the PDA and two MAs together with a double sequential no-touch vein graft to the DA and LAD. A vein graft was used to bypass the LAD due to the age of the patient and the low degree of stenosis in the LAD. The no-touch harvesting technique is described in detail in the film with complete narration. A follow-up of this patient was performed at three months both clinically and with a computed tomography angiography (CTA). No angina pectoris symptoms were reported by the patient and the wounds in the chest and lower limb were completely healed. The CTA showed patent no-touch saphenous vein grafts to all the distal anastomoses.

Rapamycin Combined with α-Cyanoacrylate Contributes to Inhibiting Intimal Hyperplasia in Rat Models / Rapamicina em Combinação com α-Cianoacrilato Contribui à Inibição de Hiperplasia Intimal em Modelos em Ratos

Abstract Background: Vein graft restenosis has an adverse impact on bridge vessel circulation and patient prognosis after coronary artery bypass grafting. Objectives: We used the extravascular supporter α-cyanoacrylate (α-CA), the local application rapamycin/sirolimus (RPM), and a combination of the two (α-CA-RPM) in rat models of autogenous vein graft to stimulate vein graft change. The aim of our study was to observe the effect of α-CA, RPM, and α-CA-RPM on vein hyperplasia. Methods: Fifty healthy Sprague Dawley (SD) rats were randomized into the following 5 groups: sham, control, α-CA, RPM, and α-CA-RPM. Operating procedure as subsequently described was used to build models of grafted rat jugular vein on carotid artery on one side. The level of endothelin-1 (ET-1) was determined by enzyme-linked immunosorbent assay (ELISA). Grafted veins were observed via naked eye 4 weeks later; fresh veins were observed via microscope and image-processing software in hematoxylin-eosin (HE) staining and immunohistochemistry after having been fixed and stored" (i.e. First they were fixed and stored, and second they were observed); α-Smooth Muscle Actin (αSMA) and von Willebrand factor (vWF) were measured with reverse transcription-polymerase chain reaction (RT-PCR). Comparisons were made with single-factor analysis of variance and Fisher's least significant difference test, with p < 0.05 considered significant. Results: We found that intimal thickness of the α-CA, RPM, and α-CA-RPM groups was lower than that of the control group (p < 0.01), and the thickness of the α-CA-RPM group was notably lower than that of the α-CA and RPM groups (p < 0.05). Conclusion: RPM combined with α-CA contributes to inhibiting intimal hyperplasia in rat models and is more effective for vascular patency than individual use of either α-CA or RPM.

Resumo Fundamento: Reestenose de enxertos venosos tem um impacto adverso na circulação de pontagens e no prognóstico de pacientes após a cirurgia de revascularização miocárdica. Objetivos: Nós utilizamos α-cianoacrilato (α-CA) como suporte extravascular, rapamicina/sirolimus (RPM) como aplicação local e a combinação dos dois (α-CA-RPM) em modelos de enxerto venoso autógeno em ratos para estimular mudança no enxerto venoso. O objetivo do nosso estudo foi observar o efeito de α-CA, RPM e α-CA-RPM na hiperplasia venosa. Métodos: Cinquenta ratos Sprague Dawley (SD) saudáveis foram randomizados nos 5 grupos seguintes: sham, controle, α-CA, RPM e α-CA-RPM. O procedimento operacional descrito subsequentemente foi utilizado para construir modelos de enxertos da veia jugular na artéria carótida em ratos, em um lado. O nível de endotelina-1 (ET-1) foi determinado por ensaio de imunoabsorção enzimática (ELISA). As veias enxertadas foram observadas a olho nu 4 semanas após; as veias frescas foram observadas via microscópio e software de processamento de imagem com coloração hematoxilina-eosina (HE) e imuno-histoquímica depois de serem fixadas e armazenadas; α-actina do músculo liso (αSMA) e o fator de von Willebrand (vWF) foram medidos com reação em cadeia da polimerase-transcriptase reversa (RT-PCR). Realizaram-se as comparações com análise de variância de fator único (ANOVA) e o teste de diferença mínima significativa (LSD) de Fisher, com p < 0,05 sendo considerado estatisticamente significante. Resultados: Nós achamos que a espessura intimal nos grupos α-CA, RPM e α-CA-RPM era menor que no grupo controle (p < 0,01) e a espessura no grupo α-CA-RPM era notavelmente menor que nos grupos α-CA e RPM (p < 0,05). Conclusão: A combinação de RPM e α-CA contribui à inibição de hiperplasia em modelos em ratos e é mais efetivo para patência vascular que uso individual de α-CA ou RPM.

Splenic vessel patency: is it real menace to perform laparoscopic splenic vessel-preserving distal pancreatectomy

PURPOSE: This study compared the patency of the splenic vessels between laparoscopic and open spleen and splenic vessel-preserving distal pancreatectomy. METHODS: We retrospectively reviewed a database of 137 patients who underwent laparoscopic (n = 91) or open (n = 46) spleen and splenic vessel-preserving distal pancreatectomy at a single institute from 2001 through 2015. Splenic vessel patency was assessed by abdominal computed tomography and classified into three grades according to the degree of stenosis. RESULTS: The splenic artery patency rate was similar in both groups (97.8 vs. 95.7%, P = 0.779). Also, the splenic vein patency rate was not significantly different between the 2 groups (74.7% vs. 82.6%, P = 0.521). Postoperative wound complication was significantly lower in the laparoscopic group (19.8% vs. 28.3%, P = 0.006), and hospital stay was significantly shorter in the laparoscopic group (7 days vs. 9 days, P = 0.001) than in the open group. Median follow-up periods were 22 months (3.7–96.2 months) and 31.7 months (4–104 months) in the laparoscopic and open groups, respectively. CONCLUSION: Laparoscopic distal pancreatectomy showed good splenic vessel patency as well as open distal pancreatectomy. For this reason, splenic vessel patency is not an obstacle in performing laparoscopic splenic vessel-preserving distal pancreatectomy.

Tratamento da doença arterial obstrutiva periférica em território femoropoplíteo com stent primário: análise em até 24 meses / Primary stenting for femoropopliteal peripheral arterial disease: analysis up to 24 months

O stent primário é uma opção de tratamento bem estabelecida para a doença arterial periférica em território femoropoplíteo. Estudos nacionais são escassos. Objetivos Avaliar desfechos clínicos e radiológicos em curto e médio prazo em pacientes classificados como Rutherford 3-6, tratados com o uso de stent em lesões femoropoplíteas. Métodos A análise foi realizada com base em um banco de dados prospectivamente mantido de doentes tratados entre julho de 2012 e julho de 2015. O objetivo primário foi a perviedade. Os objetivos secundários foram melhora na classificação de Rutherford, índice tornozelo/braço, revascularização do vaso-alvo, taxa de salvamento do membro e óbito em até 24 meses. Resultados Foram incluídos 64 pacientes, sendo 61 com lesões TASC II A/B (95%). A taxa de perviedade primária em 6, 12 e 24 meses foi de 95,2%, 79,1% e 57,9%, respectivamente. A análise de regressão de Cox revelou uma menor perviedade em pacientes com doença oclusiva (RR, 6,64, IC 95%, 1,52-28,99, p = 0,02), bem como uma perda de perviedade cerca de seis vezes maior em doentes TASC B do que TASC A (RR, 5,95, IC 95%, 1,67-21,3, p = 0,0061). Em 12 meses, 90,38% dos doentes permaneceram assintomáticos. A taxa de salvamento do membro em 24 meses foi de 94,3% (IC 95%, 87,9-100%). A ausência de revascularização do vaso-alvo em 24 meses foi de 90,5% (IC 95%, 82,8-98,9%). Conclusões Os resultados foram compatíveis com estudos internacionais, apesar do estágio mais avançado da doença vascular observada em nosso grupo. Piores desfechos foram associados a doença oclusiva e lesões complexas

Primary stenting is a well-established treatment option for femoropopliteal arterial obstructive disease. There is a shortage of Brazilian studies of the subject. Objectives To evaluate short and mid-term clinical and radiological outcomes in patients classified as Rutherford 3-6 and treated with stenting of femoropopliteal lesions. Methods Analysis based on a prospectively populated database of patients treated from July 2012 to July 2015. The primary endpoint was primary patency. Secondary endpoints were clinical and ankle/brachial index changes. Target Vessel Revascularization, limb salvage rate and death, within a 24-month follow-up period. Results 64 patients were enrolled, including 61 TASC II A / B lesions (95%). The primary patency rates at 6, 12, and 24 months were 95.2%, 79.1% and 57.9%, respectively. Cox regression analysis revealed lower patency rates in patients with occlusive disease (hazard ratio [HR], 6.64; 95% confidence interval [CI], 1.52-28,99, p = 0.02), as well as patency loss about 6 times higher in TASC B than in TASC A patients ([HR], 5.95, 95% CI, 1.67-21.3, p = 0.0061). At 12 months, 90.38% of the patients remained asymptomatic. The limb salvage rate at 24 months was 94.3% (95% CI, 87.9-100%). Freedom from TVR at 24 months was 90.5% (95% CI 82.8-98.9%). Conclusions Results of primary patency were compatible with international studies, despite the more advanced stage of the vascular disease observed in our group. Occlusive disease and complex lesions were both associated with worse outcomes

Evaluation of variables associated with the patency of arteriovenous fistulas for hemodialysis created by a nephrologist / Avaliação de variáveis associadas à permeabilidade de fístulas arteriovenosas criadas por um nefrologista para fins de hemodiálise

ABSTRACT Introduction: Arteriovenous fistula (AVF) is considered the gold standard vascular access for chronic hemodialysis, and its failure predicts higher morbidity and mortality rates. Objective: 1) To evaluate the success rate of AVF created by a nephrologist and 2) to identify clinical, laboratory, and demographic variables that influence AVF patency. Methods: A retrospective cohort study of 101 patients with chronic kidney disease for a total of 159 AVF created by a nephrologist between June 2010 and June 2013. Results: Of the AVFs created, 124 (78%) displayed immediate patency and 110 (62.9%) displayed late patency. Hemoglobin (10-12 g/dL) was the only variable related to late AVF patency (p = 0.05). An elevated blood pressure at time of surgery was associated with a lower number of procedures per patient (p = 0.001). Proximal AVF occurred more frequently in patients with dual access (p = 0.03). The AVF success rate was similar to those previously reported in the literature. Conclusion: Hemoglobin level in the recommended range has a favorable impact on late AVF patency and elevated blood pressure during surgery on the lower number of vascular accesses per patient. The high success rate indicates that it can be placed by trained nephrologists.

RESUMO Introdução: A fístula arteriovenosa (FAV) é considerada o acesso vascular padrão ouro para hemodiálise crônica, e sua falha prediz taxas mais altas de morbimortalidade. Objetivos: 1) Avaliar a taxa de sucesso da FAV criada por um nefrologista e 2) identificar variáveis clínicas, laboratoriais e demográficas que influenciam a patência da FAV. Métodos: Estudo de coorte retrospectivo de 101 pacientes com doença renal crônica, totalizando 159 FAVs criados por um nefrologista entre junho de 2010 e junho de 2013. Resultados: Das FAVs criadas, 124 (78%) apresentaram patência imediata e 110 (62,9%) apresentaram patência tardia. A hemoglobina (10-12 g/dL) foi a única variável relacionada à patência tardia da FAV (p = 0,05). A pressão arterial elevada no momento da cirurgia foi associada a um menor número de procedimentos por paciente (p = 0,001). A FAV proximal ocorreu com maior frequência em pacientes com dois acessos confeccionados (p = 0,03). A taxa de sucesso da FAV foi semelhante à relatada anteriormente na literatura. Conclusão: O nível de hemoglobina no intervalo recomendado tem um impacto favorável na perviedade tardia da FAV e pressão arterial elevada durante a cirurgia no menor número de acessos vasculares por paciente. A alta taxa de sucesso indica que ela pode ser feita por nefrologistas treinados.

Long Term Outcomes of Femorofemoral Crossover Bypass Grafts

PURPOSE: Femorofemoral crossover bypass (FCB) is a good procedure for patients with unilateral iliac artery disease. There are many articles about the results of FCB, but most of them were limited to 5 years follow-up. The purpose of our study was to analysis the results of FCB with a 10-year follow-up period. MATERIALS AND METHODS: Between January 1995 and December 2010, 133 patients were operated in Samsung Medical Center (median follow-up: 58.8 months). We retrospectively analysed patient characteristics, the preoperative treatment, the operative procedure, and material used. RESULTS: The indications for FCB were claudication in 110 and critical limb ischemia in 23 patients. Three patients were died due to myocardiac infarction, intracranial hemorrhage, and acute respiratory failure within 30 days after surgery. The one-year primary and secondary patency rates were 89% and 97%, the 5-year primary and secondary patency rates were 70% and 85%, and the 10-year primary and secondary patency rates were 31% and 67%. The 5-year and 10-year limb salvage rates were 97% and 95%, respectively. CONCLUSION: Our long term analysis suggests that FCB might be a valuable alternative treatment modality in patients with unilateral iliac artery disease.

The Combination of Sonography and Physical Examination Improves the Patency and Suitability of Hemodialysis Arteriovenous Fistula in Vascular Access

Purpose: We compared the patency and the suitability of arteriovenous fistula (AVF) created for vascular access by two approaches: (a) physical examination with preoperative vascular mapping and (b) physical examination alone. Methods: We compared the patency and the suitability of AVF created in patients for dialysis. There were two cohorts of patients of 79 patients each: (a) patients with AVF created based on the combination of physical examination and preoperative vascular mapping (PE+VM) and (b) patients with AVF created based on physical examination (PE) alone. Fistula patency is defined as clinical detection of thrill (or auscultation) of murmur over the fistula and coded as having thrills (patent) versus not having thrills (not patent). Suitability of fistula is defined as functioning AVF (AVF can be adequately used via 2-needle cannulation for dialysis) and coded as suitable versus not suitable. Results: AVF created after the preoperative vascular mapping (PE+VM) has 5.70 (at six weeks) and 3.76 (at three months) times higher chance for patency, and 3.08 times higher chance for suitable AVF for dialysis than AVF created after the physical examination (PE) alone. Conclusion: Physical examination with preoperative ultrasound mapping (PE+VM) significantly improves the short term patency and the suitability of AVF for dialysis.

Intraoperative Balloon Angioplasty Using Fogarty Artertial Embolectomy Balloon Catheter for Creation of Arteriovenous Fistula for Hemodialysis: Single Center Experience

BACKGROUND: The purpose of this study was to evaluate the use of a Fogarty arterial embolectomy catheter (Fogarty catheter) in intraoperative balloon angioplasty of the cephalic vein, in order to determine its effect on the patency of arteriovenous fistulas (AVFs) created for hemodialysis access. METHODS: A total of 156 patients who underwent creation of an AVF were divided into two groups, based whether a Fogarty catheter was used during AVF creation. Group A (89 patients) comprised the patients who underwent balloon angioplasty with a Fogarty catheter during the operation. Group B (67 patients) included the patients in whom a Fogarty catheter was not used during the operation. Patient records were reviewed retrospectively and documented. The patency rate was determined by the Kaplan-Meier method. RESULTS: The records of 156 patients who underwent the creation of an AVF from January 2007 to October 2011 were included. The mean follow-up duration was 40.2+/-19.4 months (range, 1 to 97 months). The patency rates in group A at 12, 36, and 72 months were 83.9%+/-3.9%, 78.3%+/-4.6%, and 76.3%+/-4.9%, respectively, while the corresponding patency rates in group B were 92.5%+/-3.2%, 82.8%+/-0.5%, and 79.9%+/-5.7%, respectively. The patency rates in group B were found to be slightly higher than those in group A, but the difference was not statistically significant (p=0.356). CONCLUSION: Intraoperative balloon angioplasty of the cephalic vein using the Fogarty catheter is a simple and easily reproducible procedure, and it can be helpful in increasing AVF patency in cases of insufficient runoff or a suboptimal cephalic vein.

On Postoperative Day Balloon Angioplasty for Salvage of Newly-Placed, Flow-Limiting Native Arteriovenous Fistula

PURPOSE: To report result and usefulness of immediate postoperative balloon angioplasty of de novo arteriovenous fistula (AVF) with limited flow just after creation. MATERIALS AND METHODS: From January 1, 2012 to March 31, 2014, 1,270 patients received native AVF creations in a single vascular clinic. In twenty-four patients (1.9% of total AVF creation), immediate postoperative balloon angioplasty was performed because of limited flow on palpation (only pulsation or no thrill) just after AVF creation. Medical records were reviewed retrospectively; technical success (restoration of AVF flow)/clinical success (growing as functional AVF) rate, maturation time, primary patency rate and fistula survival outcome were analyzed during a mean 10.8 months of follow-up. RESULTS: Technical/clinical success rate was 95.8% (23/24 cases); AVF flow was restored after balloon angioplasty, and all the flow-restorated AVFs grew as functional AVFs with mean+/-standard deviation, 4.5+/-1.5 weeks of maturation time. In seven (30.4%) patients, a secondary balloon angioplasty was needed to enhance maturation. The overall primary patency after immediate postoperative balloon angioplasty was 69.6% at 1 and 6 months and 59.0% at 12 months. There was 1 complication (operation site hematoma). CONCLUSION: Immediate postoperative balloon angioplasty for salvage of newly-placed, flow-limiting native AVF is a useful, effective and safe procedure.

Efeitos da Esqueletização em Comparação com a Manutenção do Pedículo da Artéria Radial sobre a Patência e Fluxo Pós-Operatórios do Enxerto / Effects of Skeletonized versus Pedicled Radial Artery on Postoperative Graft Patency and Flow

Fundamento: O enxerto de artéria radial (AR) foi o segundo enxerto arterial a ser introduzido na prática clínica para revascularização miocárdica. A técnica de esqueletização da artéria torácica interna esquerda (ATIE) pode, de fato, alterar a capacidade de fluxo do enxerto com potenciais vantagens, o que leva à suposição de que o comportamento da AR, como enxerto coronariano, seja semelhante ao da ATIE esqueletizada. Objetivo: Este estudo avaliou enxertos aortocoronários "livres" de AR, quer esqueletizados, quer com tecidos adjacentes. Métodos: Foi realizado um estudo prospectivo randomizado comparando 40 pacientes distribuídos em dois grupos. No grupo I, foram utilizadas artérias radiais esqueletizadas (20 pacientes), e no grupo II, artérias radiais com tecidos adjacentes (20 pacientes). Após o procedimento cirúrgico, os pacientes foram submetidos a medidas da velocidade de fluxo. Resultados: As principais variáveis cirúrgicas foram: diâmetro interno, comprimento e fluxo sanguíneo livre da AR. Os diâmetros médios dos enxertos de AR calculados através de angiografia quantitativa no pós-operatório imediato foram semelhantes, assim como as variáveis de medidas de velocidade de fluxo. Por outro lado, a cinecoronariografia mostrou a presença de oclusão em um enxerto de AR e estenose em cinco enxertos de AR no GII, enquanto que apenas um caso de estenose em um enxerto de AR no GI (p = 0,045). Conclusão: Os resultados mostram que tanto as características morfológicas e anatomopatológicas quanto o desempenho hemodinâmico dos enxertos livres de artéria radial, quer preparados de forma esqueletizada ou com tecidos adjacentes, são semelhantes. Entretanto, pode-se observar um maior número de lesões não obstrutivas quando a AR ...

Background: Radial artery (RA) was the second arterial graft introduced in clinical practice for myocardial revascularization. The skeletonization technique of the left internal thoracic artery (LITA) may actually change the graft's flow capacity with potential advantages. This leads to the assumption that the behavior of the RA, as a coronary graft, is similar to that of the LITA, when skeletonized. Objective: This study evaluated 'free' aortic-coronary radial artery (RA) grafts, whether skeletonized or with adjacent tissues. Methods: A prospective randomized study comparing 40 patients distributed into two groups was conducted. In group I, we used skeletonized radial arteries (20 patients), and in group II, we used radial arteries with adjacent tissues (20 patients). After the surgical procedure, patients underwent flow velocity measurements. Results: The main surgical variables were: RA internal diameter, RA length, and free blood flow in the radial artery. The mean RA graft diameters as calculated using quantitative angiography in the immediate postoperative period were similar, as well as the flow velocity measurement variables. On the other hand, coronary cineangiography showed the presence of occlusion in one RA graft and stenosis in five RA grafts in GII, while GI presented stenosis in only one RA graft (p = 0.045). Conclusion: These results show that the morphological and pathological features, as well as the hemodynamic performance of the free radial artery grafts, whether prepared in a skeletonized manner or with adjacent tissues, are similar. However, a larger number of non-obstructive lesions may be observed when RA is prepared with adjacent tissues. .

Estudo experimental comparativo de remendos arteriais de polidimetilsiloxano com reforço de tecido de poliéster (PDMSr) versus politetrafluoretileno expandido (PTFEe) em aorta de coelhos / Patch of polydimethylsiloxane reinforced with polyester fabric for aortic angioplasty in rabbits

Introdução: Apesar de bons resultados descritos na literatura, o substituto ideal para a utilização como remendo no fechamento arterial ainda não existe. Por este motivo, ainda há espaço para a busca por remendo que seja biocompatível, e que apresente facilidade de manuseio e resultados satisfatórios. Avaliamos remendos arteriais de silicone (polidimetilsiloxano com reforço em poliéster - PDMSr) em comparação com remendos arteriais de PTFEe. Objetivo: O objetivo deste trabalho é comparar, em modelo experimental, em coelhos, os resultados de remendos arteriais feitos em PDMSr com remendos de PTFEe. Materiais e Método: A amostra foi definida em 10 animais que completassem todas as etapas da pesquisa em cada grupo. Os animais foram submetidos à laparotomia mediana e abertura longitudinal da aorta de aproximadamente 8mm, realizando-se o seu fechamento com remendo do grupo selecionado, seguido do fechamento por planos. Os animais foram mantidos em biotério até o 60º PO, quando, então, realizou-se arteriografia de controle, e análise macro e microscópica de peça. Resultados: Para se atingir a amostra desejada, foram necessários 12 procedimentos no grupo PDMSr e 16 no grupo PTFEe. Ocorreram 2 óbitos no grupo PDMSr e 6 no grupo PTFEe. Apesar do número maior de óbitos no grupo PTFEe não houve diferença estatística na sobrevida entre os grupos. Um animal do grupo PDMSr apresentou monoparesia em pata posterior direita e um animal do grupo PTFEe apresentou hérnia incisional. Não houve diferença estatística nas complicações entre os grupos. O tempo operatório foi estatisticamente maior no grupo PTFEe quando comparamos todos os animais, fato que não se repetiu quando excluímos os animais que faleceram...

Introduction: Although good results are reported for various materials for use as patches for arterial closure, as yet none of these is ideal. Therefore, research is continuing into development of a patch that is biocompatible and provides ease of handling, while having satisfactory outcomes. A new silicone arterial patch (polydimethylsiloxane reinforced with polyester fabric, PDMSr) was compared with patches made of expanded polytetrafluoroethylene (ePTFE). Objective: To compare the outcomes between arterial patches made of PDMSr with those made of ePTFE, in an experimental rabbit model. Materials and Method: Rabbits were placed in two groups, and received either PDMSr or ePTFE arterial patches (PDMSr group and ePTFE group, respectively). The animals underwent laparotomy and longitudinal opening of the aorta, which was then closed with the selected patch, followed by suture of all layers. The animals were kept in their cages until the 60th postoperative day, when arteriography, removal of the aorta, and macroscopic and optic and scanning electron microscopic analyzes of the aorta were performed. Ten rabbits from each group that had completed all stages of the research were included in analyses. Results: Twelve procedures were performed in the PDMSr group and 16 in the ePTFE group. There were 2 deaths in the PDMSr group and 6 in the ePTFE group. Despite the higher number of deaths in the ePTFE group, there was no statistical difference in survival rate between the groups. One animal in the PDMSr group developed monoparesis in its right hind paw and 1 animal in the ePTFE group had an incisional hernia. There was no statistical difference in complications between the groups. The operative time was significantly longer in the ePTFE group when all animals were included in analysis, but not when animals that died were excluded...

Stent fractures after superficial femoral artery stenting / 대한외과학회지

Stent fracture is one of the major factors compromising implanted stent patency due to its consequences including in-stent restenosis, thrombosis, perforation, and migration. Stent fracture can occur from stress (extrinsic or intrinsic) and biomechanical forces at different implantation sites. We report on 2 cases of stent fractures and pertinent literature. One patient, a 75-year-old male, presented with recurrence of claudication 14 months after superficial femoral artery stenting; a femoral artery occlusion with stent fracture was found, and he underwent femoropopliteal bypass. The other patient, a 72-year-old male presented with recurrence of claudication; a stent fracture was found without femoral artery occlusion, and he was treated with additional femoral artery stenting to secure the fracture site.

Avaliação da perviedade precoce das fístulas arteriovenosas para hemodiálise / Evaluation of early patency of the arteriovenous fistulas for hemodialysis

CONTEXTO: A insuficiência renal crônica é uma doença de alta prevalência e morbidade, o que determina queda da qualidade de vida. Pacientes em hemodiálise necessitam de um acesso vascular que permita a conexão da circulação do paciente ao circuito externo de hemodiálise. Dentre os acessos disponíveis, as fístulas arteriovenosas (FAV) são as que mais se aproximam do acesso ideal. OBJETIVO: Avaliar a perviedade precoce das FAV, identificando os fatores relacionados ao insucesso destas. MÉTODOS: Foram acompanhados todos os pacientes submetidos à confecção das FAV no Hospital do Servidor Público Municipal de São Paulo, no período de agosto de 2008 a janeiro de 2009, avaliando-se a perviedade destas no 1º, 10º e 30º pós-operatório. Foram realizadas 31 FAV no período, apresentando-se média de idade de 63,06 anos, sendo 18 pacientes do sexo masculino e 13 do feminino. RESULTADOS: Vinte e seis FAV foram distais, todas radiocefálicas; quatro foram proximais, das quais duas braquiocefálicas e duas braquiobasílicas superficializadas; uma FAV confeccionada com alça de politetrafluoretileno (PTFE) fêmoro-femoral esquerda. A taxa de perviedade no primeiro mês foi de 71 por cento dos casos. O uso de cateteres venosos centrais apresentou-se como fator de risco para oclusão da FAV (p=0,01). As FAV continuam sendo o acesso vascular para hemodiálise mais aceito e mais seguro. A indicação precoce para confecção das FAV é de fundamental importância, evitando-se, assim, o uso de cateteres e suas complicações. CONCLUSÕES: A perviedade precoce encontrada neste estudo é semelhante à da literatura, e o uso prévio de cateteres é o fator de risco mais significativo para oclusão precoce desta.

BACKGROUND: Chronic renal failure is a disease of high prevalence and high morbidity, which impairs the patients' quality of life. Patients on hemodialysis need a vascular access for connection with the hemodialysis equipment. Arteriovenous fistulas (AVF) are the best option for this purpose. OBJECTIVE: To evaluate the early patency of AVFs and to identify the causes of their failure. METHODS: All patients AVF underwent operations for dialysis from August, 2008 to January, 2009. The AVF patency was evaluated on the 1st, 10th and 30th postoperative days. Thirty-one operations for AVF were performed in our hospital in the period; 18 patients were males and the mean age was 63.03 years. RESULTS: Twenty-six AVF were distal, all radial-cephalic; four were proximal, out of which two were brachiocephalic and two were brachiobasilic; one AVF was a femoral-femoral loop PTFE graft. The patency rate in the first month was of 71 percent. The use of central venous catheters was a risk factor for AVF occlusion (p=0.01). AVF remains the most accepted and safe vascular access. Early performance of the AVF is very important to avoid the complications resulting from long-term use of central venous catheters. CONCLUSIONS: Data regarding early patency found in this study were similar to those found in literature, and the use of central venous catheters before performing AVF is an important risk factor for occlusion.

Estenose do enxerto de veia safena magna reversa em revascularização arterial infrainguinal / Stenosis of reverse great saphenous vein graft in infrainguinal arterial revascularization

OBJETIVO: Avaliar a prevalência de estenose hemodinamicamente significativa na revascularização infrainguinal realizada com a veia safena magna reversa. MÉTODOS: No período compreendido entre março de 2008 e março de 2009, foram realizadas 56 revascularizações infrainguinais com a veia safena magna reversa em 56 pacientes, dos quais 32 foram avaliados com ultrassonografia vascular no 30º dia de pós- operatório. Foi analisada a prevalência de estenoses significativas nos enxertos e sua relação com as características clínico-cirúrgicas dos pacientes. Os parâmetros avaliados foram a localização das estenoses ao longo do enxerto, fatores de risco associados e a relação existente entre a ultrassonografia vascular e o índice tornozelo-braço no diagnóstico de estenoses. RESULTADOS: Houve prevalência de 48,4 por cento de estenoses significativas nos enxertos avaliados, com 19,4 por cento de estenoses graves e 29 por cento de estenoses leve a moderada. Não foram encontradas associações significativas entre sexo, diabetes mellitus, hipertensão arterial, hipercolesterolemia, diâmetro do enxerto, localização da anastomose distal, composição do enxerto e a constatação de estenoses significativas. Observou-se fraca correlação entre os métodos no diagnóstico das estenoses em geral (K = 0,30; IC95 por cento 0,232-0,473; p = 0,018), mas razoável concordância no diagnóstico das estenoses graves (K = 0,75; IC95 por cento 0,655-0,811; p = 0,0001). CONCLUSÃO: Este estudo demonstrou elevada prevalência de estenoses no 30º dia do pós-operatório, com localização predominante na metade proximal do enxerto. O índice tornozelo-braço e a ultrassonografia vascular apresentaram concordância, sobretudo no diagnóstico das estenoses graves, mas o índice tornozelo-braço, isoladamente, mostrou-se insuficiente na vigilância dos enxertos de veia safena magna reversa.

OBJECTIVE: The aim of this study was to evaluate the prevalence of hemodynamically significant infrainguinal bypasses stenosis using reverse great saphenous vein graft. METHODS: From March of 2008 to March of 2009, 56 infrainguinal bypasses were performed with reverse great saphenous vein graft in 56 patients. On the 30th post-operative day, 32 out of 56 patients were submitted to vascular ultrasonography. The prevalence of significant graft stenosis was determined. In addition, the diagnosis of stenosis was related to the clinical and surgical characteristics of the patients. The variables analyzed at the moment of diagnosis were the localization of the graft stenosis, the risk factors associated with stenosis and the association of vascular ultrasonography findings with ankle brachial pressure index (ABI). RESULTS: The overall prevalence of significant graft stenosis was 48.4 percent. Out of the total number of observed stenosis, 19.4 percent were considered severe, and 29 percent mild or moderate. There was no significant association between the presence of significant stenosis and the following variables: gender, diabetes, hypertension, smoking, hipercholesterolemia, graft diameter, site of the distal anastomosis, and graft composition. There was a weak agreement between ABI and vascular ultrasonography in detecting stenosis in general (K = 0.30; CL95 percent 0.232 - 0.473; p = 0.018). However, there was a substantial agreement in detecting severe stenosis (K = 0.75; CL95 percent 0.655 - 0.811; p = 0.0001). CONCLUSION: There was a high prevalence of stenosis on the 30th post-operative day, mostly localized in the proximal half of the vein graft. There was no significant association of stenosis with clinical and surgical factors analyzed. ABI and vascular ultrasonography had weak agreement with the diagnosis of stenosis in general and an important agreement for the diagnosis of severe stenosis.

Clinical Analysis of Hemodialysis Vascular Access: Comparision of Autogenous Arterioveonus Fistula & Arteriovenous Prosthetic Graft

BACKGROUND: Mature autogenous arteriovenous fistulas have better long term patency and require fewer secondary interventions compared to arteriovenous prosthetic graft. Our Study evaluated vascular patency rates and incidence of interventions in autogenous arteriovenous fistulas and grafts. MATERIAL AND METHODS: A total of 166 vascular access operations were performed in 153 patients between December 2002 and November 2009. Thirty seven caeses were excluded due to primary access failure and loss of follow-up. One group of 92 autogenous arterioveous fistulas and the other group of 37 arteriovenous prosthetic grafts were evaluated retrospectively. Primary and secondary patency rates were estimated using the Kaplan-Meier method. RESULTS: The primary patency rate (84%, 67%, 51% vs. 51%, 22%, 9% at 1, 3, 5 year; p=0.0000) and secondary patency rate (96%, 88%, 68% vs. 88%, 65%, 16% at 1. 3, 5 year; p=0.0009) were better in autogenous fistula group than prosthetic graft group. Interventions to maintain secondary patency were required in 23% of the autogenous fistula group (average 0.06 procedures/patient/year) and 65% of prosthetic graft group (average 0.21 procedures/patient/year). So the autogenous fistula group had fewer intervention rate than prosthetic graft group (p=0.01) The risk factor of primary patency was diabetus combined with ischemic heart disease and the secondary patency's risk factor was age. CONCLUSION: Autogenous arteriovenous fistulas showed better performance compared to prosthetic grafts in terms of primary & secondary patency and incidence of interventions.

Tratamento de tromboembolismo pulmonar por aspiração percutânea do trombo: relato de caso / Pulmonary thromboembolism treatment by percutaneous clot aspiration: case report

O tromboembolismo pulmonar (TEP) maciço é uma importante causa de mortalidade. A principal causa de óbito é a disfunção do ventrículo direito, provocada pela alta resistência ao seu fluxo de ejeção, e a sobrevida do paciente, nessas situações, depende da pronta desobstrução das artérias pulmonares. A anticoagulação, o uso de trombolíticos e a embolectomia pulmonar representam opções terapêuticas consolidadas para diferentes cenários clínicos de TEP. A Radiologia Intervencionista representa hoje uma alternativa terapêutica para pacientes com TEP maciço e contraindicação ao uso de trombolíticos, sendo uma escolha menos invasiva do que a embolectomia. Os autores relataram um caso de paciente com TEP maciço e contraindicação à trombólise, a qual foi submetida a aspiração percutânea dos trombos das artérias pulmonares, e discutiram os principais mecanismos de técnicas endovasculares para tratamento de TEP.

Massive pulmonary thromboembolism is an important cause of mortality. Its main cause of death is the failure of the right ventricle, due to the high resistance to its outflow, and the patient survival, on these cases, depends on prompt recanalization of the pulmonary arteries. Anticoagulation, use of thrombolytics and pulmonary embolectomy represent established therapeutic options to different clinical scenarios of pulmonary thromboembolism. Nowadays, Interventional Radiology represents an alternative to treat patients with massive pulmonary thromboembolism and contra-indications to thrombolytics, and is a less invasive option compared to embolectomy. The authors reported a case of a patient with massive pulmonary thromboembolismand contra-indication to thrombolysis, who was submitted to percutaneous clot aspiration of the pulmonary arteries, and discussed the main mechanisms of endovascular techniques of pulmonary thromboembolism treatment.

Early Vascular Access Blood Flow as a Predictor of Long-term Vascular Access Patency in Incident Hemodialysis Patients

The long-term clinical benefits of vascular access blood flow (VABF) measurements in hemodialysis (HD) patients have been controversial. We evaluated whether early VABF may predict long-term vascular access (VA) patency in incident HD patients. We enrolled 57 patients, of whom 27 were starting HD with arteriovenous fistulas (AVFs) and 30 with arteriovenous grafts (AVGs). The patients' VABF was measured monthly with the ultrasound dilution technique over the course of the first six months after the VA operation. During the 20.4-month observational period, a total of 40 VA events in 23 patients were documented. The new VA events included 13 cases of stenosis and 10 thrombotic events. The lowest quartile of average early VABF was related to the new VA events. After adjusting for covariates such as gender, age, hypertension, diabetes, VA type, hemoglobin levels, body mass index, parathyroid hormone, and calcium-phosphorus product levels, the hazard ratio of VABF (defined as <853 mL/min in AVF or <830 mL/min in AVG) to incident VA was 3.077 (95% confidence interval, 1.127-8.395; P=0.028). There were no significant relationships between early VABF parameters and VA thrombosis. It is concluded that early VABF may predict long-term VA patency, particularly VA stenosis.

Can Cilostazol Improve the Patency Rate of Native Arteriovenous Fistula in Hemodialysis Patients? / 대한신장학회지

PURPOSE: Vascular access failure is the most common reason for hospitalization among hemodialysis (HD) patients. Cilostazol, which has antiplatelet action and vasodialtory effects, significantly reduces the risk of restenosis after percutaneous coronary intervention in many patients. We conducted this study to evaluate the relationship between the use of antiplatelet agents, especially cilostazol, and arteriovenous fistula (AVF) patency in HD patients. METHODS: A total of 241 patients underwent native AVF creation from January 2001 to December 2008. Among these patients, we selected 86 patients excluding 38 patients (15.8%) with primary technical failure, 49 patients without complete data and 68 patients used cilostazol less than 1 month. Demographic characteristics, medication history and fistula failure rate were collected and analyzed to elucidate the effect of cilostazol to native AVF. RESULTS: From all groups, AVF failure occurred in 24 patients (27.9%). 28 patients received cilostazol (62.3 %) and mean duration of cilostazol therapy was 229.5+/-115.7 days. All patients were classified into two groups according to cilostazol (Cilostazol [n=28, 32.6%] vs. non-Cilostazol [n=58, 67.4%]. There was no statisticallly significant difference in failure rate between the two groups (32.1% vs. 25.9%, p=0.543). In diabetes group, patients who received statin have much lower AVF failure rate (0% vs. 32.4%, p=0.024). Logistic regression analysis showed that female was independent risk factor for access failure (HR 5.549, CI 1.104-27.877, p=0.037). CONCLUSION: Cilostazol and other antiplatelet agent had a no significant association with AVF patency. Female was an independent risk factor for access failure.