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.

COMPARATIVE STUDY OF MICROANASTOMOSIS WITH DISTINCT 10-0 NYLON SUTURES IN RATS

ABSTRACT Objective: The aim of this study is to compare micro-sutures commonly used in our midst. Methods: In this double-blind study, 30 Wistar rats were operated randomly divided into three groups matched according to the suture used (Nylon 10-0, 75micron, brands Microsuture(r), Polysuture(r) and Ethicon(r)). We analyzed the number of surgical nodes required, bleeding, surgical time and histological evaluation. Results: There was no significant difference between the amount of stitches of arterial suture per anastomosis. Surgical time was longer in Microsuture(r) group as compared to Polysuture(r) (p ≤ 0.05). Bleeding in Microsuture(r) group was higher when compared to the others (p <0.01). In the histological analysis, the Microsuture(r) group showed a greater tendency to develop fibrosis and aneurysm in surgical site than the others (p <0.01 and p≤0,05, respectively). Similarly, the Ethicon(r) group showed less tendency to myointimal proliferation than the rest. (p = 0.025). Conclusion: The results confirm the relevance of the choice of surgical thread as an independent determining factor for the success of the procedure, besides serving as a rational subsidy for a better cost-benefit analysis. Level of Evidence I, Experimental Study, Controlled Animal Study.

Exposure of the surgical team to ionizing radiation during orthopedic surgical procedures / Exposição da equipe cirúrgica à radiação ionizante durante procedimentos cirúrgicos ortopédicos

OBJECTIVE: the aim of this study was to assess the degree of exposure of the orthopedic surgical team to fluoroscopic ionizing radiation. METHODS: the ionizing radiation to which the orthopedic surgical team (R1, R2 and R3) was exposed was assayed using thermoluminescent dosimeters that were distributed in target anatomical regions (regions with and without protection using a lead apron). This was done during 45 hip osteosynthesis procedures to treat transtrochanteric fractures that were classified as 31-A2.1 (AO). RESULTS: the radioactive dose received by R3 was 6.33 mSv, R2 4.51 mSv and R3 1.99 mSv (p = 0.33). The thyroid region received 0.86 mSv of radiation, the thoracic region 1.24 mSv and the gonadal region 2.15 mSv (p = 0.25). There was no record of radiation at the dosimeters located below the biosafety protectors or on the team members' backs. CONCLUSIONS: the members of the surgical team who were located closest to the fluoroscope received greater radiation doses than those located further away. The anatomical regions located below the waistline were the ones that received most ionizing radiation. These results emphasize the importance of using biosafety devices, since these are effective in preventing radiation from reaching the vital organs of the medical team...

OBJETIVO: avaliar o grau de exposição da equipe cirúrgica ortopédica à radiação ionizante fluoroscópica. MÉTODOS: foi dosada a radiação ionizante incidida sobre a equipe cirúrgica ortopédica (R1, R2 e R3) com dosímetros termoluminescentes, distribuídos em regiões anatômicas alvo, com e sem a proteção de avental de chumbo, durante 45 procedimentos de osteossíntese de quadril (DHS), por fraturas transtrocantéricas classificadas como 31-A2.1 (AO). RESULTADOS: a dose radioativa sobre o R3 foi de 6,33 mSv, de 4,51 mSv sobre o R2 e de 1,99 mSv sobre o R1 (p = 0,33). A região da tireoide recebeu 0,86 mSv de radiação, a região torácica 1,24 mSv e a região gonadal 2,15 mSv (p = 0,25). Não houve registro de radiação nas dosímetros localizados abaixo dos protetores de biossegurança ou nas costas dos membros da equipe. CONCLUSÕES: os membros da equipe cirúrgica que ficaram mais próximos do fluoroscópio receberam maiores doses de radiação do que os que ficaram mais remotamente. As regiões anatômicas abaixo da linha cintura foram as que mais receberam radiação ionizante. Os resultados ressaltam a importância do uso de dispositivos de biossegurança, os quais são efetivos em impedir que a radiação atinja órgãos vitais dos integrantes da equipe médica...