Estudio Comparativo entre la Bupivacaína (S75-R25) y la Ropivacaína para Evaluar la Seguridad Cardiovascular en el Bloqueo del Plexo Braquial

ResumenJustificativa y objetivosLa Bupivacaína es el fármaco por elección para la anestesia regional por poseer una eficacia, una larga duración y un bloqueo motor menos intenso. La Bupivacaína (S75-R25) consiste en una mezcla de isómeros ópticos que contienen un 75% de levobupivacaína (S-) y un 25% de dextrobupivacaína (R+), y fue creada por una compañía farmacéutica brasileña. Este estudio comparó la eficacia y la seguridad de la bupivacaína S75-R25 con el vasoconstrictor y la ropivacaína para el sistema cardiovascular en el bloqueo del plexo braquial.MétodosEl equipo de investigación colocó de forma aleatoria a los pacientes que recibirían el bloqueo del plexo braquial con la bupivacaína S75-R25 (Grupo B) o la ropivacaína (Grupo R), ambos fármacos al 0,50%, y 30mL de epinefrina 1:200.000. El ECG continuo (Holter) se registró durante todo el procedimiento, como también la escala de fuerza de Lovett, además de la monitorización (frecuencia cardíaca, oximetría de pulso y presión arterial no invasiva). La incidencia de eventos adversos fue comparada con los test del Xi-Cuadrado (Xi2) o exacto de Fisher.ResultadosFueron divididos en dos grupos 44 pacientes. No hubo diferencia significativa con relación a la edad, peso, altura, sexo y tiempo de operación. No hubo diferencia entre las arritmias supraventriculares antes o después del bloqueo del plexo braquial, independientemente del anestésico local elegido. La pérdida de sensibilidad fue más rápida en el Grupo B (23,1 ± 11,7min) en comparación con el Grupo R (26,8 ± 11,5min), aunque no fuere significativa (p = 0,205, test t de Student). Hubo una reducción de la frecuencia cardíaca, observada durante la monitorización continua de 24 horas (Holter).ConclusionesEste estudio demostró una eficacia parecida entre la bupivacaína S75-R25 y la ropivacaína para el bloqueo del plexo braquial, con incidencias parecidas de arritmias supraventriculares

Estudo anatômico do sistema arterial dorsal da mão

Historically, the dorsal arterial system of the hand received less attention than the palmar system. The studies concerning dorsal arterial anatomy present some controversies regarding the origin and presence of the dorsal metacarpal artery branches. Knowledge of the anatomy of dorsal metacarpal arteries is especially applied in the surgical planning for flaps taken from the dorsum of the hand. The purpose of this study is to analyze the arterial anatomy of the dorsum of the hand, compare our observations with those of previous studies from the literature, and therefore to define parameters for surgical planning for flaps supplied by the dorsal metacarpal arteries. METHOD: Twenty-six dissections were performed at the dorsum of the right hand of 26 cadavers by making a distal-based U-shaped incision. After catheterization of the radial artery at the wrist level, a plastic dye solution with low viscosity and quick solidification was injected to allow adequate exposure of even small vessels. The radial artery and its branches, the dorsal arterial arch, the dorsal metacarpal arteries, the distal and proximal communicating branches of the palmar system, and the distal cutaneous branches were carefully dissected and identified. RESULTS: The distal cutaneous branches originating from the dorsal metacarpal arteries were observed in all cases; these were located an average of 1.2 cm proximal from the metacarpophalangeal joint. The first dorsal metacarpal artery presented in 3 different patterns regarding its course: fascial, subfascial, and mixed. The branching pattern of the radial artery at the first intermetacarpal space was its division into 3 branches. We observed the presence of the dorsal arterial arch arising from the radial artery in 100% of the cases. The distance between the dorsal arterial arch and the branching point of the radial artery was an average of 2 cm. The first and second dorsal metacarpal arteries were visualized in all cases. The third and fourth dorsal metacarpal arteries were visualized in 96.2% and 92.3% of cases, respectively. There was proximal and distal communication between the dorsal arterial arch and the palmar system through the communicating branches contributing to the dorsal metacarpal artery formation. CONCLUSION: At the dorsum of the hand there is a rich arterial net that anastomoses with the palmar arterial system. This anatomical characteristic allows the utilization of the dorsal aspect of the hand as potential donor site for cutaneous flaps.Historicamente o sistema arterial dorsal da mão recebeu menos atenção em relação ao palmar. Os trabalhos que abordam a anatomia arterial dorsal apresentam pontos divergentes no que se refere a origem, a freqüência e a presença de ramos das artérias metacarpais dorsais. Este conhecimento se aplica, em especial, no planejamento cirúrgico de retalhos que tenham como área doadora o dorso da mão. O objetivo deste trabalho é o de estudar a anatomia do sistema arterial dorsal da mão, confrontando estes achados com os da literatura e desta maneira, definir parâmetros para o planejamento dos retalhos supridos pelas artérias metacarpais dorsais da mão. CASUÍSTICA E MÉTODO: Foram realizadas 26 dissecções na região dorsal da mão direita de 26 cadáveres, através de uma incisão em forma de U de base distal. Após a cateterização da artéria radial a nível do punho, foi injetado um corante plástico de baixa viscosidade e rápida solidificação que permitiu adequada visibilização até mesmo de pequenos vasos. A artéria radial e seus ramos, o arco dorsal, as artérias metacarpais dorsais, os ramos comunicantes distais e proximais do sistema palmar e os ramos cutâneos distais, foram cuidadosamente dissecados e identificados. RESULTADOS: Os ramos cutâneos distais provenientes das artérias metacarpais dorsais foram observados em todos os casos, em média, a 1,2 cm proximal a articulação metacarpo-falangeana. A primeira artéria metacarpal dorsal apresentou três padrões diferentes em relação ao seu trajeto no primeiro espaço intermetacarpal: fascial, subfascial e misto. O padrão de ramificação da artéria radial, no primeiro espaço intermetacarpal, foi o de sua divisão em três ramos. Observamos a presença do arco arterial dorsal em 100% dos casos, com sua origem na artéria radial. A distância entre a emergência do arco dorsal e o ponto de ramificação da artéria radial foi em média de 2 cm. As artérias primeira e segunda metacarpais dorsais estiveram presentes em todos os casos. As artérias terceira e quarta metacarpais dorsais estiveram presentes em 96,2% e 92,3% dos casos, respectivamente. Constatamos que houve uma comunicação proximal e distal do arco dorsal com o sistema palmar, através de ramos comunicantes que contribuíram para a formação das artérias metacarpais dorsais. CONCLUSÃO: Existe uma rica rede arterial no dorso da mão, que apresenta um grande número de anastomoses com o sistema arterial palmar, permitindo a utilização desta região como uma fonte potencial de retalhos cutâneos

What has changed in brachial plexus surgery?

Brachial plexus injuries, in all their severity and complexity, have been extensively studied. Although brachial plexus injuries are associated with serious and often definitive sequelae, many concepts have changed since the 1950s, when this pathological condition began to be treated more aggressively. Looking back over the last 20 years, it can be seen that the entire approach, from diagnosis to treatment, has changed significantly. Some concepts have become better established, while others have been introduced; thus, it can be said that currently, something can always be offered in terms of functional recovery, regardless of the degree of injury. Advances in microsurgical techniques have enabled improved results after neurolysis and have made it possible to perform neurotization, which has undoubtedly become the greatest differential in treating brachial plexus injuries. Improvements in imaging devices and electrical studies have allowed quick decisions that are reflected in better surgical outcomes. In this review, we intend to show the many developments in brachial plexus surgery that have significantly changed the results and have provided hope to the victims of this serious injury

A new low-cost negative-pressure wound therapy versus a commercially available therapy device widely used to treat complex traumatic injuries: a prospective, randomized, non-inferiority trial

OBJECTIVES: Negative-pressure wound therapy has been widely adopted to reduce the complexity of treating a broad range of acute and chronic wounds. However, its cost is high. The objective of this study was to evaluate the following two different methods of negative-pressure wound therapy in terms of healing time: a low-cost method of negative-pressure wound therapy (a pressure stabilizer device connected to a hospital wall-vacuum system with a gauze-sealed dressing, USP) and the standard of care (vacuum-assisted closure, VAC). METHODS: This is a randomized, controlled, non-inferiority, unblinded trial. Patients admitted with complex injuries to a trauma center in a public referral hospital who were indicated for orthopedic surgery were randomized to a USP or VAC group. The primary outcome was the time required to achieve a “ready for surgery condition”, which was defined as a wound bed with healthy granulation tissue and without necrosis or purulent secretion. Wound bed area contraction, granulation tissue growth and the direct costs of the dressings were secondary outcomes. RESULTS: Variation in area and granulation tissue growth were essentially the same between the systems, and healing time was equal between the groups (p=0.379). In both systems, serial debridement increased wound area (p=0.934), and granulation tissue was also increased (p=0.408). The mean treatment cost was US$15.15 in the USP group and US$ 872.59 in the VAC group. CONCLUSIONS: For treating complex traumatic injuries, USP was non-inferior to and less expensive than VAC

Structured evaluation of a comprehensive microsurgical training program

OBJECTIVES: This study proposed a structured microsurgical training program and evaluated it with the assistance of a large sample of surgeons. METHODS: The practical course comprised 16 sessions of approximately 4 hours each. This included two sessions for suturing rubber gloves and two sessions for suturing arteries, veins, and nerves in chicken thighs. The other sessions were performed on the femoral vessels of rats: 5 sessions for end-to-end arterial anastomosis, 5 for end-to-end venous anastomosis, 1 for arterial grafting, and 1 for end-to-side anastomosis. We conducted a structured assessment of the microsurgical skills in each training session. RESULTS: In this study, 89 surgeons were evaluated. The mean scores for the different procedures were as follows: glove suturing, 33.3±0.59; chicken nerve end-to-end anastomosis, 40.3±0.49; chicken artery suturing, 40.9±0.36; chicken vein suturing, 42.3±0.36; graft interposition, 44.8±0.7; and end-to-side anastomosis, 43.7±0.63 (p<0.05 for all). The chicken thigh suturing scores were significantly higher than the rubber gloves suturing scores (p<0.01). There were no differences between scores of the rat artery and chicken thigh suturing procedures (p=0.24). The rat venous anastomosis scores were higher than the rat arterial anastomosis scores (p=0.02), as were graft interposition scores when compared with end-to-end venous anastomosis scores. The end-to-side anastomosis scores did not differ significantly from the grafting scores (p=0.85). The most common errors were inadequate knotting technique and suture rupture due to inadequate technique (both n=88 [98.9%]). CONCLUSION: We propose a 16-step, progressive microsurgical training program to learn the basic microsurgical techniques comprehensively and reliably. The program was evaluated in a large sample of trainees, and it demonstrated the adequacy of the training sequence and results

Evaluation of functional gain of the elbow following Steindler surgery for brachial plexus injury

OBJETIVO: Avaliar ganho de força e amplitude de movimento do cotovelo após cirurgia de Steindler Modificada em pacientes com lesão do tronco superior do plexo braquial. MÉTODO: Foram acompanhados de 1998 a 2007 onze pacientes com lesão traumática fechada do tronco superior do plexo braquial. Todos apresentavam evolução de pelo menos 1 ano da lesão e grau de força de flexão do cotovelo que variou de M1 a M3. Os pacientes foram submetidos à cirurgia de Steindler modificada e seguidos por período mínimo de 6 meses. Realizadas avaliações pré e pós-operatórias do ganho de força muscular, amplitude de movimento do cotovelo e pontuação conforme escala DASH. RESULTADOS: Dos onze pacientes analisados, nove (82%) atingiram nível de força igual ou maior a M3 (MRC). Dois (18%) chegaram ao nível de força M2(MRC). Observamos que os pacientes apresentaram ganho médio de amplitude de movimento do cotovelo pós-operatória de 43,45 graus. A média de flexão do cotovelo pós-operatória foi de 88 graus. Houve melhora da função do cotovelo demonstrada na Escala DASH em 81% dos pacientes do estudo. CONCLUSÃO: A cirurgia de Steindler Modificada mostrou-se eficaz no tratamento dos pacientes com lesão de tronco superior de plexo braquial, com ganho estatisticamente significativo de amplitude de movimento. Em todos os casos algum grau de ganho de força e amplitude de flexão do cotovelo, sendo tanto maior quanto maior a força muscular inicial. Nível de Evidência: Nível II, ensaio clínico prospective.OBJECTIVE: To evaluate the gain in strength and range of motion after modified Steindler surgery of the elbow in patients with lesions of the upper trunk of the brachial plexus. METHOD: From 1998 to 2007, eleven patients with traumatic closed upper trunk lesion of the brachial plexus were studied. All the patients had development of at least 1 year of injury and degree of strength of elbow flexion ranging from M1 to M3. The patients underwent Steindler surgery with at least 6 months of follow-up. Pre- and post-operative assessments were carried out to determine gain in muscle strength, range of motion of the elbow, and DASH scale score. RESULTS: Of the eleven patients studied, nine (82%) achieved a level of strength equal to or greater than M3 (MRC) with good functional recovery. Two (18%) reached strength level M2 (MRC). We observed that the patients had an average postoperative gain in range of motion of the elbow of 43.45 degrees. The average elbow flexion after surgery was 88 degrees. There was an improvement in elbow function, as demonstrated in the DASH Scale, in 81% of the patients studied. CONCLUSION: Modified Steindler surgery was effective in the treatment of patients with injuries of the upper trunk of the brachial plexus, with statistically significant gains in range of motion. In all the cases studied, there was some degree of gain in strength and range of elbow flexion, the gain being correlated with the initial muscle strength. Level of Evidence: Level II, prospective clinical trial

Experimental study of histological changes in vascular loops according to the duration of the postoperative period: Application in reconstructive microsurgery

OBJECTIVES: To analyze the histological changes observed in venous grafts subjected to arterial blood flow as a function of the duration of the postoperative period to optimize their use in free flap reconstructions. METHOD: Twenty-five rats (7 females and 18 males) underwent surgery. Surgeries were performed on one animal per week. Five weeks after the first surgery, the same five animals were subjected to an additional surgery to assess the presence or absence of blood flow through the vascular loop, and samples were collected for histological analysis. This cycle was performed five times. RESULTS: Of the rats euthanized four to five weeks after the first surgery, no blood flow was observed through the graft in 80% of the cases. In the group euthanized three weeks after the first surgery, no blood flow was observed in 20% of the cases. In the groups euthanized one to two weeks after the first surgery, blood flow through the vascular loop was observed in all animals. Moreover, intimal proliferation tended to increase with the duration of the postoperative period. Two weeks after surgery, intimal proliferation increased slightly, whereas strong intimal proliferation was observed in all rats evaluated five weeks after surgery. CONCLUSION: Intimal proliferation was the most significant change noted in venous grafts as a function of the duration of the postoperative period and was directly correlated with graft occlusion. In cases in which vascular loops are required during free flap reconstruction, both procedures should preferably be performed during the same surgery

Revisiting the metallothionein genes polymorphisms and the risk of oral squamous cell carcinoma in a Brazilian population

Metallothioneins (MTs) gene polymorphisms have been associated with the ability of free radical scavenging and detoxification of heavy metals leading to cancer development. Our aim was to revisit, in a Brazilian population, single-nucleotide polymorphisms (SNPs) of the MT gene family previously associated with oral squamous cell carcinoma (OSCC). A case-control investigation with 28 OSCC patients and 45 controls was conducted, using conventional risk factors (tobacco use and alcohol consumption) as covariates. SNPs genotyping for rs8052334 (MT1B), rs964372 (MT1B), and rs1610216 (MT2A) was performed by PCR-RFLP, and SNPs for rs11076161 (MT1A) were analyzed by TaqMan assay. The only SNP associated with increased risk for OSCC was the MT-1A AA genotype (OR = 4.7; p = 0.01). We have also evidenced for the first time a significant linkage disequilibrium between the SNPs of MT-2A and MT-1A in this population with the highest frequency (30%) of the unfavorable haplotype G/A/C/T (rs1610216 / rs11076161 / rs964372 / rs8052334) of MT gene polymorphisms (OR = 6.2; p = 0.04). Interestingly, after removing the effects of conventional risk factors, we have uncovered the significance of the AA genotype of the rs11076161 with increased odds of 19-fold higher towards OSCC development. This is the first demonstration that a significant linkage disequilibrium among gene polymorphisms of the MT family may affect susceptibility to oral cancer, which is conditioned by the G/A/C/T haplotype (rs1610216/rs11076161/rs964372/ rs8052334) and the MT-1A gene polymorphism has a potential clinical utility for the OSCC risk assessment

Results of ulnar nerve neurotization to brachial biceps muscle in brachial plexus injury

OBJETIVO: Avaliar de forma crítica os fatores que influenciam os resultados da neurotização do nervo ulnar no ramo motor do músculo bíceps braquial, visando a restauração da flexão do cotovelo em pacientes com lesão do plexo braquial. MÉTODOS: 19 pacientes, 18 homens e uma mulher, com idade média de 28,7 anos foram avaliados entre fevereiro de 2003 e maio de 2007. Oito pacientes apresentavam lesão das raízes C5-C6 e 11, das raízes C5-C6-C7. O intervalo de tempo médio entre a injúria e o tratamento cirúrgico foi 7,5 meses. Quatro pacientes apresentavam fraturas cervicais associadas à lesão do plexo braquial. O seguimento pós-operatório foi de 15,7 meses. RESULTADO: Oito pacientes recuperaram força de flexão do cotovelo MRC grau 4; dois, MRC grau 3 e nove, MRC < 3. Não houve prejuízo da função prévia do nervo ulnar. CONCLUSÃO: Os resultados da cirurgia de neurotização do nervo ulnar no ramo motor no músculo bíceps braquial são dependentes: do intervalo decorrido entre a lesão do plexo e o tratamento cirúrgico, da presença de fraturas associadas da coluna cervical e côndilo occipital, da função residual das raízes de C8-T1 após o trauma e do acometimento da raiz de C7. Sinais de reinervação manifestados até 3 meses no pós cirúrgico mostram melhores resultados ao longo prazo. Nível de Evidência: IV, Série de Casos

Distribuição de Hg total e suas associações com diferentes suportes geoquímicos em sedimentos marinhos da margem continental brasileira: Bacia de Campos - Rio de Janeiro

Mercury distribution and geochemical support on the Continental Margin was evaluated at the Campos Basin, Rio de Janeiro state, Brazil. The average concentrations for all analyzed elements were, respectively, 20 ± 5 ng g-1 (Hg); 30 ± 14 mg g-1 (Al); 16 ± 6 mg g-1 (Fe), and 254 ± 83 µg g-1 (Mn). Silt and clay content, total carbonate and Hg, and organic carbon increased with depth. Finally, the relationship between Hg and silt clay showed significant positive correlation. Total Hg concentrations are the background level described primarily (~40 ng g-1)