EFFECT OF HYPERBARIC OXYGEN THERAPY ON NERVE REGENERATION IN RATS.

Objective: To evaluate histological changes in peripheral nerves of rats after sciatic nerve neurorrhaphy, according to the time of exposure to hyperbaric oxygen chamber treatment. Methods: Twenty-five Wistar rats were divided into 5 groups according to the amount of exposure to hyperbaric oxygen chamber treatment. Group 1 was the control and there was no use of hyperbaric oxygen chamber; group 2 received one week of therapy; group 3, two weeks; group 4, three weeks; and group 5, four weeks. After the fourth postoperative week, the animals were submitted to euthanasia and a sciatic nerve sample sent for histological analysis. Axons proximal and distal to the neurorrhaphy were counted with axonal regeneration index measurement. Results: We observed that the number of axons distal to neurorrhaphy increases with the amount of hyperbaric oxygen chamber exposure, the results were more expressive from the third week of treatment. However, the statistical analysis found no significant difference between the groups. Conclusion: The descriptive analysis suggests benefit of using hyperbaric oxygen chamber directly proportional to the time of therapy. The study, however, did not present statistically relevant results, probably due to the reduced sample size. Subsequent studies with more significant sampling would be of great value. Level of Evidence II, Prospective Comparative Study.

Objetivo: Avaliar as alterações histológicas nos nervos periféricos após neurorrafia do nervo ciático de ratos, de acordo com o tempo de exposição ao tratamento com câmara hiperbárica de oxigênio. Métodos: Vinte e cinco ratos da raça Wistar foram divididos em cinco grupos conforme o tempo de exposição ao tratamento com câmara hiperbárica de oxigênio. O grupo 1 não recebeu o tratamento; o grupo 2 recebeu uma semana de terapia; o grupo 3, duas semanas; o grupo 4, três semanas; e o grupo 5, quatro semanas. Após quatro semanas de pós-operatório, os animais foram submetidos à eutanásia e uma amostra do nervo ciático foi enviada para análise histológica. Foram feitas contagens do número de axônios proximalmente e distalmente à neurorrafia, com medição do índice de regeneração axonal. Resultados: Observamos que o aumento do número de axônios distais à neurorrafia foi diretamente proporcional ao tempo de exposição à câmara hiperbárica de oxigênio, sendo mais expressivo a partir da terceira semana de tratamento. Entretanto, a análise estatística não encontrou diferença significativa entre os grupos. Conclusão: A análise descritiva sugere benefício do uso da câmara hiperbárica de oxigênio. Porém, devido à amostra reduzida, o estudo não apresentou resultados estatisticamente relevantes, sendo necessária a realização de estudos subsequentes com amostragem mais significativa. Nível de Evidência II, Estudo Prospectivo Comparativo.

RADIOCARPAL FRACTURE DISLOCATIONS: A NEW CLASSIFICATION AND TREATMENT PROPOSAL.

Introduction: The radiographic and surgical findings, and treatment of radiocarpal fracture dislocations, were analyzed retrospectively in 40 patients. Materials and Methods: All patients were classified according to Dumontier´s radiological classification and compared with the surgical findings. Based on this analysis, a new classification and treatment are proposed. Results: From 1995 to 2018, 40 patients with radiocarpal fracture dislocation underwent surgery. Thirty-six were males and four were females. The mean age was twenty-four years (range: 18-45). Three dislocations were volar dislocations and 37 were displaced dorsally. Initially, 8 (20%) patients were classified as group I, 29 (72.5%) as group II, and 3 (7.5%) remained unclassified. The main variations occurred in group II. Seven fractures were stable after radial styloid fixation and 6 remained unstable. Sixteen fractures presented articular fragments or an interposed capsule, which prevented anatomical reduction using conservative maneuvers. Conclusion: Based in our intraoperative observations and surgical results, we believe that a more detailed classification should be adopted. Level of Evidence IV; Therapeutic Studies; Case Series.

Introdução: Os achados radiográficos, cirúrgicos e o tratamento das fraturas-luxações radiocárpicas foram analisados retrospectivamente em 40 pacientes. Materiais e Métodos: Todos os pacientes foram classificados de acordo com a classificação radiológica de Dumontier e comparados com os achados cirúrgicos. Com base nessa análise, uma nova classificação e tratamento são propostos. Resultados: De 1995 a 2018, 40 pacientes com fratura-luxação radiocárpica foram submetidos à cirurgia. Trinta e seis eram homens e quatro mulheres. A média de idade foi de vinte e quatro anos (variação de 18 a 45). Três luxações eram volares e 37 dorsais. Inicialmente, 8 (20%) pacientes foram classificados como Grupo I, 29 (72,5%), como Grupo II e 3 (7,5%), permaneceram sem classificação. As variações principais ocorreram no Grupo II. Sete fraturas permaneceram estáveis depois da fixação da estiloide radial e 6 permaneceram instáveis. Dezesseis fraturas apresentaram fragmentos articulares ou cápsula interposta que impediu a redução anatômica por manobras conservadoras. Conclusões: Com base em nossas observações intraoperatórias e nos resultados cirúrgicos, acreditamos que uma classificação mais detalhada deva ser adotada. Nível de evidência IV;Estudos Terapêuticos; Série de casos.

Effect of hyperbaric oxygen therapy on nerve regeneration in rats / Efeito da terapia hiperbárica de oxigênio na regeneração nervosa em ratos

ABSTRACT Objective: To evaluate histological changes in peripheral nerves of rats after sciatic nerve neurorrhaphy, according to the time of exposure to hyperbaric oxygen chamber treatment. Methods: Twenty-five Wistar rats were divided into 5 groups according to the amount of exposure to hyperbaric oxygen chamber treatment. Group 1 was the control and there was no use of hyperbaric oxygen chamber; group 2 received one week of therapy; group 3, two weeks; group 4, three weeks; and group 5, four weeks. After the fourth postoperative week, the animals were submitted to euthanasia and a sciatic nerve sample sent for histological analysis. Axons proximal and distal to the neurorrhaphy were counted with axonal regeneration index measurement. Results: We observed that the number of axons distal to neurorrhaphy increases with the amount of hyperbaric oxygen chamber exposure, the results were more expressive from the third week of treatment. However, the statistical analysis found no significant difference between the groups. Conclusion: The descriptive analysis suggests benefit of using hyperbaric oxygen chamber directly proportional to the time of therapy. The study, however, did not present statistically relevant results, probably due to the reduced sample size. Subsequent studies with more significant sampling would be of great value. Level of Evidence II, Prospective Comparative Study.

RESUMO Objetivo: Avaliar as alterações histológicas nos nervos periféricos após neurorrafia do nervo ciático de ratos, de acordo com o tempo de exposição ao tratamento com câmara hiperbárica de oxigênio. Métodos: Vinte e cinco ratos da raça Wistar foram divididos em cinco grupos conforme o tempo de exposição ao tratamento com câmara hiperbárica de oxigênio. O grupo 1 não recebeu o tratamento; o grupo 2 recebeu uma semana de terapia; o grupo 3, duas semanas; o grupo 4, três semanas; e o grupo 5, quatro semanas. Após quatro semanas de pós-operatório, os animais foram submetidos à eutanásia e uma amostra do nervo ciático foi enviada para análise histológica. Foram feitas contagens do número de axônios proximalmente e distalmente à neurorrafia, com medição do índice de regeneração axonal. Resultados: Observamos que o aumento do número de axônios distais à neurorrafia foi diretamente proporcional ao tempo de exposição à câmara hiperbárica de oxigênio, sendo mais expressivo a partir da terceira semana de tratamento. Entretanto, a análise estatística não encontrou diferença significativa entre os grupos. Conclusão: A análise descritiva sugere benefício do uso da câmara hiperbárica de oxigênio. Porém, devido à amostra reduzida, o estudo não apresentou resultados estatisticamente relevantes, sendo necessária a realização de estudos subsequentes com amostragem mais significativa. Nível de Evidência II, Estudo Prospectivo Comparativo.

Radiocarpal fracture dislocations: a new classification and treatment proposal / Fratura-luxação radiocárpica: nova classificação e proposta de tratamento

ABSTRACT Introduction The radiographic and surgical findings, and treatment of radiocarpal fracture dislocations, were analyzed retrospectively in 40 patients. Materials and Methods All patients were classified according to Dumontier´s radiological classification and compared with the surgical findings. Based on this analysis, a new classification and treatment are proposed. Results From 1995 to 2018, 40 patients with radiocarpal fracture dislocation underwent surgery. Thirty-six were males and four were females. The mean age was twenty-four years (range: 18-45). Three dislocations were volar dislocations and 37 were displaced dorsally. Initially, 8 (20%) patients were classified as group I, 29 (72.5%) as group II, and 3 (7.5%) remained unclassified. The main variations occurred in group II. Seven fractures were stable after radial styloid fixation and 6 remained unstable. Sixteen fractures presented articular fragments or an interposed capsule, which prevented anatomical reduction using conservative maneuvers. Conclusion Based in our intraoperative observations and surgical results, we believe that a more detailed classification should be adopted. Level of Evidence IV; Therapeutic Studies; Case Series.

RESUMO Introdução Os achados radiográficos, cirúrgicos e o tratamento das fraturas-luxações radiocárpicas foram analisados retrospectivamente em 40 pacientes. Materiais e Métodos Todos os pacientes foram classificados de acordo com a classificação radiológica de Dumontier e comparados com os achados cirúrgicos. Com base nessa análise, uma nova classificação e tratamento são propostos. Resultados De 1995 a 2018, 40 pacientes com fratura-luxação radiocárpica foram submetidos à cirurgia. Trinta e seis eram homens e quatro mulheres. A média de idade foi de vinte e quatro anos (variação de 18 a 45). Três luxações eram volares e 37 dorsais. Inicialmente, 8 (20%) pacientes foram classificados como Grupo I, 29 (72,5%), como Grupo II e 3 (7,5%), permaneceram sem classificação. As variações principais ocorreram no Grupo II. Sete fraturas permaneceram estáveis depois da fixação da estiloide radial e 6 permaneceram instáveis. Dezesseis fraturas apresentaram fragmentos articulares ou cápsula interposta que impediu a redução anatômica por manobras conservadoras. Conclusões Com base em nossas observações intraoperatórias e nos resultados cirúrgicos, acreditamos que uma classificação mais detalhada deva ser adotada. Nível de evidência IV;Estudos Terapêuticos; Série de casos.

Reduction of Morbidity With a Reverse-Flow Sural Flap: A Two-Stage Technique.

The reverse sural flap has often been used for cutaneous coverage of the distal region of the leg and ankle. When the flap is performed in 2 stages, the vascular pedicle is exteriorized and later resected. Our goal was to assess the reverse sural flap performed in 2 stages regarding its viability and low morbidity along the flap-donor area. Eleven patients with cutaneous coverage loss found in the area between the distal third of the leg and ankle underwent cutaneous coverage surgery with a reverse-flow sural flap with an exteriorized pedicle, without violation of the skin between the base of the flap pedicle to the margin of the wound. After a minimum period of 15 days with flap autonomy, the pedicle was resected. The flap dimensions, its viability before and after the pedicle ligature, and the distance from the intact skin between the flap base and the margin of the wound were evaluated. Any losses were measured as a percentage of the total flap size. The respective length and width of the flap were a mean average of 7.45 cm × 4.18 cm. All the flaps survived. Partial loss of the flap occurred in 3 patients, ranging from 20% to 30%. The mean average distance of the intact skin between the pedicle base and the margin of the wound was 5.59 (range 4 to 8) cm. Our results showed that the 2-stage reverse sural flap ensures good flap survival and low morbidity.

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.

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.

A reinforcement of the sutured microvascular anastomosis with fibrin glue application: A retrospective comparative study with the standard conventional technique.

PURPOSE: Although a reasonable number of studies report satisfactory results with fibrin glue application in microvascular anastomosis since 1977, its utilization in the clinical setting has being scant in the literature. The aim of this study was to report the cumulated experience with the fibrin glue in free flaps over a period of 10 years, comparing the survival rate with the standard sutured anastomosis. PATIENTS AND METHODS: From August 2001 through November 2014, 83 consecutive free flaps were performed by a team of surgeons from two hospitals. About 56 flaps were performed in 56 patients using the fibrin glue augmented microvascular anastomosis and 27 flaps were performed in 27 patients using the conventional anastomosis technique. The decision on whether or not the fibrin glue should be used at the anastomoses was based on its availability and whose surgeon was performing the anastomoses. About approximately 60% of sutures stitches were used that would be used in a conventional anastomosis, when fibrin glue application was anticipated (ranging from 5 to 7 sutures in the arteries and 5 to 8 in the veins). RESULTS: The overall survival rate of the flaps performed with fibrin glue application was 92.85%. In one case, a revision of the venous anastomosis was required due to early flap congestion. Four cases (7.14%) had failure of the first free flap and two of them were submitted to another free flap without fibrin glue application. In the flaps performed with the conventional anastomosis technique the survival rate was 92.59%. This difference was not statistically significant (P = 0.97). CONCLUSION: The application of fibrin glue in microvascular anastomoses did not increase the rate of flap loss and had a potential to reduce the number of sutures required to complete an anastomosis by its sealing effect. © 2016 Wiley Periodicals, Inc. Microsurgery 37:218-221, 2017.

Intercostal nerve transfer to the biceps motor branch in complete traumatic brachial plexus injuries.

The purpose of this report is to critically evaluate our results of two intercostal nerve transfers directly to the biceps motor branch in complete traumatic brachial plexus injuries. From January 2007 to November 2012, 19 patients were submitted to this type of surgery, but only 15 of them had a follow-up for ≥2 years and were included in this report. The mean interval from trauma to surgery was 6.88 months (ranging from 3 to 9 months). Two intercostals nerves were dissected and transferred directly to the biceps motor branch. The mean follow-up was 38.06 months (ranging from 24 to 62 months). Ten patients (66.6%) recovered an elbow flexion strength ≥M3. Four of them (26.66%) recovered a stronger elbow flexion ≥M4. One patient (6.25%) recovered an M2 elbow flexion and four patients (26.66%) did not regain any movement. We concluded that two intercostal nerve transfers to the biceps motor branch is a procedure with moderate results regarding elbow flexion recovery, but it is still one of the few options available in complete brachial plexus injuries, especially in five roots avulsion scenario.

Median nerve fascicle transfer versus ulnar nerve fascicle transfer to the biceps motor branch in C5-C6 and C5-C7 brachial plexus injuries: nonrandomized prospective study of 23 consecutive patients.

The purpose of this study was to observe whether the results of the median nerve fascicle transfer to the biceps are equivalent to the classical ulnar nerve fascicle transfer, in terms of elbow flexion strength and donor nerve morbidity. Twenty-five consecutive patients were operated between March 2007 and July 2013. The patients were divided into two groups. In Group 1 (n = 8), the patients received an ulnar nerve fascicle transfer to the biceps motor branch. In Group 2 (n = 15), the patients received a median nerve fascicle transfer to the biceps motor branch. Two patients with follow-up less than six months were excluded. Both groups were similar regarding age (P = 0.070), interval of injury (P = 0.185), and follow-up period (P = 0.477). Elbow flexion against gravity was achieved in 7 of 8 (87.5%) patients in Group 1, versus 14 of 15 (93.3%) patients in Group 2 (P = 1.000). The level of injury (C5-C6 or C5-C7) did not affect anti-gravity elbow flexion recovery in both the groups (P = 1.000). It was concluded that the median nerve fascicle transfer to the biceps is as good as the ulnar nerve fascicle transfer, even in C5-C7 injuries.

Limb replantation after avulsion injuries: techniques and tactics for success.

OBJECTIVES: Retrospective evaluation of cases of limb replantation after avulsion injuries. Evaluation of the techniques and tactics used, that contributed to success and good functional results. METHODS: Forty-three patients' records were assessed. All the cases had been submitted to limb replantation after avulsion injuries. RESULTS: The majority of the cases were young men. The most common injury was to the thumbs. The surgical techniques and tactics used were: nerve grafting, vein grafting, transposition of the digital vessels, limb shortening, and heterotopic replantation. The most commonly used technique was vein graft. The limb survival rate was high (93%), as was patient satisfaction. CONCLUSION: Replantation after avulsion injury depends on the correct diagnosis of the limb viability and the use of appropriate surgical techniques and tactics for each case. The experience of the team of surgeons and a good hospital structure are essential for good results. There are few articles in medical literature about the indications, techniques and results of limb replantation after avulsion injuries. We believe that this retrospective evaluation can bring new information and contributions to the correct management of this highly complex situation. Level of evidence IV, Case Series.

Reimplantes nas amputações por mecanismo de avulsão: táticas e técnicas para o sucesso / Limb replantation after avulsion injuries: techniques and tactics for success

OBJETIVOS: Avaliação retrospectiva criteriosa de casos de reimplantes após amputação por avulsão. Avaliação de técnicas e táticas utilizadas que determinaram evolução satisfatória e bom resultado funcional. METÓDOS: Foram avaliados, retrospectivamente, prontuários de 43 pacientes que tiveram membros amputados por mecanismo de avulsão e reimplantados nos últimos 21 anos. RESULTADOS: A maior parte dos casos envolvia homens adultos jovens. A localização de amputação mais frequente foi do polegar. As técnicas e táticas cirúrgicas utilizadas isoladas ou conjuntamente incluem: enxertos de nervo, enxertos vasculares (veia ou artéria), transposição de feixe vascular digital, encurtamento do membro e reimplante heterotópico. A técnica mais frequentemente utilizada foi o emprego de enxertos venosos. A taxa de sobrevida dos reimplantes foi alta (93%), assim como a satisfação dos pacientes. CONCLUSÃO: Os reimplantes por mecanismo de avulsão dependem do correto diagnóstico de viabilidade anatômica e utilização de técnicas e táticas cirúrgicas apropriadas para cada caso. A experiência da equipe cirúrgica e estrutura hospitalar adequada são fundamentais para obtenção de bons resultados. Existem poucos relatos na literatura sobre indicação, tática, técnicas e resultados de procedimentos de reimplantes em amputações por avulsão. Acreditamos que a avaliação retrospectiva desta série de casos possa trazer novas informações e contribuições no atendimento desta situação de alta complexidade. Nível de evidência IV, Série de casos.

OBJECTIVES: Retrospective evaluation of cases of limb replantation after avulsion injuries. Evaluation of the techniques and tactics used, that contributed to success and good functional results. METHODS: Forty-three patients' records were assessed. All the cases had been submitted to limb replantation after avulsion injuries. RESULTS: The majority of the cases were young men. The most common injury was to the thumbs. The surgical techniques and tactics used were: nerve grafting, vein grafting, transposition of the digital vessels, limb shortening, and heterotopic replantation. The most commonly used technique was vein graft. The limb survival rate was high (93%), as was patient satisfaction. CONCLUSION: Replantation after avulsion injury depends on the correct diagnosis of the limb viability and the use of appropriate surgical techniques and tactics for each case. The experience of the team of surgeons and a good hospital structure are essential for good results. There are few articles in medical literature about the indications, techniques and results of limb replantation after avulsion injuries. We believe that this retrospective evaluation can bring new information and contributions to the correct management of this highly complex situation. Level of evidence IV, Case Series.