Preferential use of nonreversed vein grafts in above-knee femoropopliteal bypasses for critical ischemia: midterm outcome.

We evaluated nonreversed vein grafts in above-knee bypasses for chronic critical limb ischemia in a retrospective study with intention-to-treat analysis in patients who underwent above-knee bypass grafting. During a 4-year period, 51 patients (men, 32; women, 19; mean age = 66 years) with 53 critically ischemic lower extremities underwent above-knee femoropopliteal bypass grafting. The follow-up evaluation consisted of clinical examination, assessment of the ankle-brachial systolic blood pressure index, and, whenever necessary, duplex scanning. Three (5.7%) deaths occurred within 30 days, two from myocardial infarction and one from an undetermined cause. The 2-year cumulative success rate was 82.5 +/- 9.6% for primary patency, 84.6 +/- 8.9% for secondary patency, 90.1 +/- 7.3% for tertiary patency, 86.9 +/- 7.6% for limb salvage, 77.7 +/- 8.4% for survival, 68.0 +/- 11.1% for composite patency, and 68.4 +/- 9.3% for amputation-free survival; the corresponding estimates for vein grafts alone were 86.6 +/- 9.2%, 88.9 +/- 8.6%, 89.0 +/- 8.5%, 88.1 +/- 8.1%, 81.1 +/- 9.1, 76.8 +/- 11.1%, and 72.6 +/- 10.2%. Three prosthetic grafts failed and were replaced with an arm vein graft. Nonreversed vein bypass grafts in above-knee revascularization of critically ischemic limbs are justified.

Meta-analysis of infrapopliteal angioplasty for chronic critical limb ischemia.

BACKGROUND: Percutaneous transluminal angioplasty has been used with increasing frequency in the treatment of infrainguinal arterial occlusive disease. This meta-analysis aimed to assess the middle-term outcomes after crural angioplasty in patients with chronic critical limb ischemia and compare results with a meta-analysis of popliteal-to-distal vein bypass graft. METHODS: Data were retrieved from 30 articles published from 1990 through 2006 (63% of articles published between 2000 and 2006). All studies used survival analysis, reported a 12-month cumulative rate of patency or limb salvage, and included at least 15 infrapopliteal angioplasties. The outcome measures were immediate technical success, primary and secondary patency, limb salvage, and patient survival. Data from life-tables, survival curves, and texts were used. RESULTS: The pooled estimate of success was 89.0% +/- 2.2% for immediate technical result. Results at 1 and 36 months were 77.4% +/- 4.1% and 48.6% +/- 8.0% for primary patency, 83.3% +/- 1.4% and 62.9% +/- 11.0% for secondary patency, 93.4% +/- 2.3% and 82.4% +/- 3.4% for limb salvage, and 98.3% +/- 0.7% and 68.4% +/- 5.5% for patient survival, respectively. Studies with >75% of the limbs with tissue loss fared worse than their respective comparative subgroup for technical success and patency but not for limb salvage or survival. No publication bias was detected. CONCLUSION: The technical success and subsequent durability of crural angioplasty are limited compared with bypass surgery, but the clinical benefit is acceptable because limb salvage rates are equivalent to bypass surgery. Further studies are necessary to determine the proper role of infrapopliteal angioplasty.

An updated meta-analysis of infrainguinal arterial reconstruction in patients with end-stage renal disease.

BACKGROUND: A previous meta-analysis reported on the mid-term outcomes of infrainguinal bypass grafts in patients with critical limb ischemia and end-stage renal disease. Given the competing interest in endovascular procedures, the results of bypass surgery must be assessed as precisely as possible for future comparison. In this study, the original meta-analysis was refined and updated by increasing the number of studies reviewed, estimating primary graft patency, extending follow-up time, and investigating the problem of early amputation despite a patent graft. METHODS: Studies published from 1987 through 2005 were identified from two electronic databases. Two investigators independently extracted the survival data from life tables, survival curves, and texts. Pooled survival curves were then constructed for graft patency, limb salvage, and patient survival according to a random-effects protocol for meta-analysis. RESULTS: Of 28 articles included, 18 reported amputation despite a patent graft in 84 (10%) out of 844 limbs, and 25 described a perioperative mortality of 88 (8.8%) out of 996 patients. The 5-year pooled estimate (SE) was 50.4% (15.4%) for primary patency, 50.8% (19.0%) for secondary patency, 66.6% (11.2%) for limb salvage, and 23.0% (11.7%) for patient survival. No publication bias was detected. CONCLUSIONS: Limb salvage can be achieved in most end-stage renal disease patients who undergo bypass surgery for critical ischemia, but survival is poor. To avoid early amputation despite a patent graft, bypass grafting should not be offered to patients with a great amount of tissue loss or extensive infection.

Importance of the arteriographic anatomy of the descending genicular artery and sural arteries in patients with atherosclerotic occlusion of the popliteal artery.

Bypasses to the descending genicular artery (DGA) or the medial sural artery (MSA) have been performed with acceptable rates of midterm success. The arteriographic appearance of the DGA, the MSA, and the lateral sural artery (LSA) was described and the applicability of bypass to these vessels was investigated. The arteriograms of 45 patients who had occlusion of the below-knee popliteal artery were analyzed to determine the presence, dominance, and extension of collaterals for each perigeniculate branch, which were used to assess the applicability of a perigeniculate bypass. A dominant perigeniculate artery was found in 26 arteriograms and corresponded to 13 DGAs, 9 MSAs, and 4 LSAs. Of 14 applicable perigeniculate bypasses, 2 would be an obligatory bypass and 12 would be an alternative to a conventional infrapopliteal bypass. Although rarely an obligatory solution, a bypass to a perigeniculate branch artery represents a valuable alternative.

Meta-analysis of femoropopliteal bypass grafts for lower extremity arterial insufficiency.

BACKGROUND: In femoropopliteal bypass surgery, the use of saphenous vein grafts is preferable, but synthetic grafts are widely used above the knee. The objective of this meta-analysis was to assess the long-term patency of femoropopliteal bypass grafts classified as above-knee polytetrafluoroethylene, above-knee saphenous vein, or below-knee saphenous vein. METHODS: Studies published from 1986 through 2004 were identified from electronic databases and reference lists; 73 articles contributed 1 or more series that used survival analysis, assessed femoropopliteal bypasses in one of the foregoing configurations, reported a 1-year graft patency rate, and included at least 30 bypasses. The series with a predominance of claudicant patients were included in meta-analysis C, and the series in which critical ischemia predominated were included in meta-analysis CI. Pooled survival curves of graft patency were constructed. RESULTS: In meta-analysis C, the pooled primary graft patency was 57.4% for above-knee polytetrafluoroethylene, 77.2% for above-knee vein, and 64.8% for below-knee vein at 5 years; there was a significant difference between above-knee grafts at 3, 4, and 5 years (P < .05). The corresponding pooled secondary graft patency was 73.2%, 80.1%, and 79.7%, respectively (P > .05). In meta-analysis CI, the pooled primary graft patency was 48.3% for above-knee polytetrafluoroethylene, 69.4% for above-knee vein, and 68.9% for below-knee vein at 5 years; there was a significant difference between above-knee grafts until 4 years (P < .05). The corresponding pooled secondary graft patency was 54.0%, 71.9%, and 77.8%, respectively, with a significant difference between above-knee grafts at 2, 3, and 4 years (P < .05). CONCLUSIONS: The great saphenous vein performs better than polytetrafluoroethylene in femoropopliteal bypass grafting and should be used whenever possible.

Meta-analysis of popliteal-to-distal vein bypass grafts for critical ischemia.

BACKGROUND: Several studies have described the use of popliteal-to-distal bypass grafts, mostly in patients with diabetes mellitus who show tissue loss and represent a high-risk population. The study objective was to conduct meta-analysis to assess the long-term primary and secondary patency and foot preservation after popliteal-to-distal bypass grafts. METHODS: Data was retrieved from studies published from 1981 through 2004 that were identified from an electronic database. Thirty-one series that used survival analysis reported a 1-year graft patency rate and included at least 15 bypasses. Data from life tables, survival curves, and texts were used to calculate an interval success rate for each month in each series of grafts. Monthly success rates were combined across series to obtain a pooled estimate of success for each month, according to a random-effects protocol for meta-analysis. Pooled survival curves were then constructed for graft patency and foot preservation. RESULTS: The 5-year pooled estimate +/- standard error was 63.1% +/- 4.3% for primary patency, 70.7% +/- 4.6% for secondary patency, and 77.7% +/- 4.3% for foot preservation. There was a superiority trend favoring reversed vein grafts and tibial bypasses that became more apparent in sensitivity analysis. No publication bias was detected. CONCLUSION: The popliteal-to-distal vein bypass is a tool of high efficiency in the treatment of severe, chronic critical ischemia in the lower extremity.

Meta-analysis of alternate autologous vein bypass grafts to infrapopliteal arteries.

BACKGROUND: Several studies have described acceptable results for infrapopliteal bypass surgery that uses an autogenous vein other than the greater saphenous vein but is still no reliable prediction of outcomes. The objective of this study was to use meta-analysis to assess the long-term outcomes after infrapopliteal bypass grafting done with alternate autologous veins. METHODS: Studies published from 1982 through 2004 were identified from electronic databases and pertinent original articles. Thirty-two series were selected, all of which had used survival analysis and had reported a 1-year graft patency rate, with at least 15 bypasses. An interval success rate was calculated for each month in each series of grafts by using data from life tables, survival curves, and texts. Monthly success rates were combined across series to obtain a pooled estimate of success for each month. Pooled survival curves were then constructed for graft patency and foot preservation. RESULTS: The 5-year pooled estimates were 46.9% (95% confidence interval [CI] = 35.5%-58.3%) for primary patency, 66.5% (95% CI = 54.9%-78.2%) for secondary patency, and 76.4% (95% CI = 68.0%-84.8%) for foot preservation. These results were far superior to those reported for nonautologous grafts. Intensive duplex surveillance had a favorable impact on graft patency and foot preservation. No publication bias was detected. CONCLUSIONS: When the greater saphenous vein is unavailable, alternate autologous veins are preferable to other graft materials in bypass surgery to infrapopliteal arteries.

Meta-analysis of polytetrafluoroethylene bypass grafts to infrapopliteal arteries.

CONTEXT: Reports of polytetrafluoroethylene (PTFE) bypass grafting to the infrapopliteal arteries have often used survival analysis of acceptable quality to describe a wide range of long-term results. In theory, these results may be combined if variability between series and time intervals is considered. OBJECTIVE: Meta-analysis was performed to gain insight into long-term graft patency and foot preservation after PTFE bypass grafting to infrapopliteal arteries. DATA SOURCE: Studies published from 1982 through 2001 were identified from the PubMed database and pertinent original articles. STUDY SELECTION: Three investigators selected 43 studies that used survival analysis, reported 2-year patency rates, and included at least 15 bypass procedures. Data extraction and transformation: Based on standard life-tables or survivor curves, an interval success rate was calculated for each month in each series. The monthly success rates were combined across series, enabling construction of pooled survivor curves. DATA SYNTHESIS: Random-effects meta-analysis yielded 5-year pooled estimates (SE) of 30.5% (7.6%) for primary graft patency, 39.7% (5.5%) for secondary graft patency, and 55.7% (5.0%) for foot preservation. During the entire follow-up, pooled estimates were slightly higher for series of PTFE grafts with adjunctive procedures compared with series of PTFE grafts only. Sensitivity analysis: A simulation using only unfavorable assumptions showed a decrease of less than 5% at 5 years for all outcomes, and smaller differences at subgroup meta-analysis. Funnel plots suggested that publication bias was unlikely. CONCLUSION: This meta-analysis indicated moderate success for PTFE bypass grafts to infrapopliteal arteries, but the role of adjunctive procedures at the distal anastomosis remains uncertain.

Medicina e estatistica / Medicine and statistics

O medico-pesquisador habitualmente emprega testes de hipotese, intervalos de confianca ou ambas as tecnicas estatisticas na analise dos resultados de suas pesquisas. Se por um lado essa tarefa simplificou-se com o uso de programas estatisticos em microcomputadores, contribui tambem para afastar o medico do convivio com o estatistico e com os conceitos da Estatistica. Mostra-se nesta rota que a colaboracao do estatistico melhora a qualidade da pesquisa medica, tomando-se como exemplo as afirmacoes probalisticas sob o enfoque classico em comparacao com o enfoque bayesiano. Evidentemente, nem mesmo a simples consideracao da analise bayesiana ocorreria sem a cooperacao do estatistico. Ademais, nota-se que esta analise fornece informacoes probabilisticas direta e clara, em contraste com o palavreado tortuoso e indireto que e tipico de teoria classica...

Tratamento cirurgico das telangiectasias / Surgical treatment of telangiectasis

O objetivo do trabalho e apresentar o tratamento das telangiectasias por cirurgia associada a escleroterapia. A casuistica se compos de dois individuos do sexo feminino com telangiectasias extensas e antiesteticas no membro inferior, que foram considerados casos tipicos para indicacao da tecnica proposta: a eliminacao do refluxo venoso. As veias adjacentes foram ressecadas sob anestesia local seguidas de incisoes cutaneas de cerca de 2 mm, uso de agulha de croche e sintese da pele por aproximacao das bordas com fitas adesivas. Escleroterapia foi feita simultaneamente. O resultado estetico foi otimo em ambos os casos, com desaparecimento completo das telangiectasias, documentado em fotografias. O metodo proposto deve ser considerado preferencial em casos de telangiectasias provocadas por refluxo venoso evidente

Tratamento cirurgico de infeccoes comprometendo proteses arteriais em posicao aorto-femoral / Surgical treatment of infection complicating the arterial prosthesis in aorto-femoral position

O objetivo do trabalho e avaliar o resultado do tratamento cirurgico de infeccoes comprometendo proteses aorto-femorais. A casuistica e composta de 20 doentes que foram divididos em grupos de acordo com o tipo de tratamento instituido. Os grupos foram: A) medidas locais com manutencao da protese infectada; B) retirada parcial da protese nao acompanhada de nova restauracao arterial (B1) ou acompanhada de nova restauracao (B2); C) retirada total da protese infectada, sem (C1) ou com (C2) nova restauracao arterial. Os resultados foram aferidos pela taxa de sobrevida do doente e pelo efeito paliativo efetivo (preservacao da vida, dos membros inferiores e ausencia de infeccao). A taxa de sobrevida apos um, 12, 24, 36 e 48 meses foi, respectivamente, 80 por cento, 60 por cento, 53 por cento, 42 por cento e 27 por cento. O efeito paliativo foi de 50 por cento apos 30 dias e 27 por cento apos 48 meses. O tratamento ideal da infeccao da protese aorto-femoral e a retirada completa desta protese acompanhada de nova restauracao arterial.

Infeccao comprometendo proteses arteriais: quadro clinico, etiologia e fatores predisponentes / Infection complicating arterial prosthesis: clinical manifestations, etiology and predisposing factors

O resumo do estudo e descrever as caracteristicas clinicas de doentes com infeccao comprometendo proteses arteriais. A casuistica se compoe de 30 doentes submetidos a reconstrucao arterial com protese que apresentam um dos seguintes eventos: 1) protese exposta atraves de fistulas cutaneas; 2) protese em comunicacao com o interior de visceras ocas; 3) proteses envolvidas por secrecao purulenta ou 4) proteses cujo fragmento ou secrecao envolvente resultou em cultura positiva. As manifestacoes clinicas mais frequentes foram fistula cutanea em 21 (70 por cento), hemorragia externa em 14 (47 por cento), exposicao da protese em cinco (17 por cento), aneurisma anastomotico em cinco (17 por cento) e fistula enterica em quatro (13 por cento). Em metade dos casos a infeccao ocorreu no primeiro ano apos a implantacao da protese. Os agentes etiologicos mais frequentes foram estafilococos e bacterias Gram-negativas. Em todos doentes houve disseccao na regiao inguinal e os defeitos de cicatrizacao nesta regiao foram frequentes, principalmente apos reoperacoes.

Autotransplante de rim em 12 casos de lesao da arteria renal / Kidney auto transplantation in 12 cases of renal artery lesion

O objetivo deste trabalho e analisar os resultados em 12 autotransplantes renais, cuja indicaçao cirurgica foi anomalia da arteria renal. O diagnostico foi arterite primaria da aorta em sete casos, displasia fibromuscular em tres e aterosclerose em dois casos. Os pacientes apresentavam hipertensao arterial incontrolavel. O autotransplante foi indicado por razoes bem definidas: fibrose periaortica, reoperaçoes, arterias renais multiplas, lesoes de ramos ou pacientes pediatricos. Em seis casos foi feito o autotransplante convencional, enquanto nos seis restantes empregou-se reconstruçao microcirurgica sob hipotermia prolongada. Nao houve obitos nem nefrectomia secundaria. Em dez casos a reconstruçao arterial foi bem-sucedida, em um foi incompleta e em 1 houve trombose. O autotransplante renal e tecnica alternativa muito util quando os procedimentos habituais nao podem ser empregados com segurança

Amputaçäo de membro inferior por doença arterial periférica: análise de 167 casos consecutivos näo selecionados / Lower limb amputation due to peripheral vascular disease: analysis of 167 non-selected consecutive cases

Cento e sessenta e sete pacientes submetidos a amputaçäo de membro inferior por doença vascular periférica foram avaliados. As amputaçöes eram primárias em 81 casos (grupo I) e secundárias a algum tipo de reconstruçäo arterial em 86 (grupo II). a estratificaçäo quanto a faixa etária demosntrou diferença estatisticamente significante na constituiçäo dos dois grupos (p < 0,025). Os índices quanto a distribuiçäo dos níveis iniciais de amputaçäo também demosntraram diferença estatisticamente significante (p < 0,025). Houve predomínio de amputaçöes abaixo do joelho (85%) no grupo com amputaçöes primárias em relaçäo ao grupo com amputaçöes secundárias (70%). A mortalidade geral observada foi de 7% (12 pacientes). Quanto a cicatrizaçäo primária, para os pacientes com oclusäo femoropoplítea, os índices foram de 77% no grupo I e 44% no grupo II (p < 0,001). Estes dados devem ser ponderados no processo decisório entre revascularizaçäo ou amputaçäo primária em doentes de risco, assim como ressaltam a importância dos cuidados de técnica operatória em ambos os procedimentos

A simpatectomia lombar em casos de arteriosclerose periférica infra-inguinal e isquemia grave

Os autores analisam os resultados cirúrgicos de 94 simpatectomias lombares feitas para tratamento de obstruçäo crônicas arterioscleróticas e isquemia grave em 88 doentes, no período de 1980 a 1986. Os resultados foram verificados aos seis meses do período pós-operatório, com apenas seis doentes sendo perdidos no seguimento. A mortalidade operatória foi de 2% e os resultados foram bons em 43% dos casos. Entretanto, considera a neurotripsia da perna como medida auxiliar, o índice de sucesso se elevou a 49%. Os resultados foram significativamente melhores nos doentes mais jovens, naqueles com índice pressórico tornozelo-braço acima de 0,3 e nos casos de lesäo trófica. A taxa de sucessäo relativa aos anos de 1985 foi inferior a do período 1980 a 1984, sem alcançar significado estatístico. Os autores aceitam que a simpatectomia lombar possa ter mérito no tratamento de doentes com insquemia grave, principalmente reduzindo a realizaçäo de reocnstruçöes arteriais de alto risco em certas situaçöes especiais. É impossível no momento estabelecer com certeza a relaçäo de causa e efeito entre ssimpatectomia e o alívio dos sintomas

Estudo da funçäo de rins transplantados no pós-operatótio imediato / Function of transplanted kidneys in the immediate post-operative period

Com a finalidade de melhor caracterizar as funçöes glomerular, e tubular de rins transplantados no pós-operatório imediato, foram estudados dez receptores e seus respectivos doadores 48 e 72 horas após o transplante, em período em que a volemia e a osmolalidade plasmática já eram normais nos receptores e semelhante a dos doadores. Nenhum receptor apresentou insuficiência renal aguda ou rejeiçäo durante o período da observaçäo, mas eram hipertenso. A filtraçäo glomerular, medida pelas depuraçöes de uréia e creatinina, foram comparáveis nos dois grupos e normais para indivíduos com um só rim. A funçäo tubular foi avaliada pela excreçäo de sódio, potássio, cálcio e fósforo e pela depuraçäo osmolar e da água livre. A depuraçäo e excreçäo fracional de cálcio foi semelhante nos dois grupos. Os receptores apresentaram depuraçäo e excreçäo fracional de potássio semelhante a dos doadores de depuraçäo de água livre positiva. Esses dados foram interpretados como evidência de funçäo tubular distal intacta receptores. Ao contrário, a excreçäo fracional de sódio (p < 0,05) e de fósforo (p < 0,01) foi significativamente mais elevada nos receptores. Esses resultados sugerem a existência de disfunçäo tubular proximal independente de fatores osmóticos e volêmicos. Esta disfunçäo pode ser intrínseca ou secundária a alteraçöes hemodinâmicas específicas do rim transplantado ou a agentes hormonais

Reabilitaçäo em doentes amputados por doença arterial periférica

Cinquenta e um pacientes com amputaçöes de membro inferior decorrentes de doença arterial periférica foram avaliados quanto a condiçöes e tempo de reabilitaçäo e acompanhados no seguimento tardio por um período médio de 24 meses. Trinta e três pacientes (64%) eram diabéticos. Sucesso imediato de reabilitaçäo foi considerado como a recuperaçäo da marcha bi-pedal com prótese. Quarenta e cinco pacientes (88%) atingiram esta condiçäo. O tempo médio de reabilitaçäo para amputados ao nível da perna foi de três meses e para amputados ao nível da coxa de cinco meses. No seguimento tardio a avaliaçäo foi feita quanto `a persistência no uso da prótese e grau de independência de vida. A mortalidade foi estudada pelo método atuarial. Todos os pacientes amputados na perna (100%) usavam a prótese para locomoçäo e tinham vida independente no último seguimento, enquanto 75% dos amputados em coxa estavam em uso da prótese e apenas 25% tinham vida totalmente independente. A mortalidade estudada pelo método atuarial foi analisada para pacientes diabéticos e näo diabéticos. Todas as mortes exceto uma ocorreram nos diabéticos, resultando neste grupo sobrevida cumulativa de 31% em 4 anos