Jefferson André Pires

Effects of hyperbaric oxygen and N-acetylcysteine in survival of random pattern skin flaps in rats

Objective: Our aim is to investigate the role of HBO (hyperbaric oxygen), NAC (N-acetylcysteine), and HBO plus NAC on the necrosis area of random rats skin flaps of a modified McFarlane flap design. Materials and Methods: Thirty-two male Wistar rats were randomly divided into four groups: G-S (sham: n = 8), G-NAC (NAC: n = 8), G-HBO (HBO: n = 8), and G-HN (HBO plus NAC: n = 8). A rectangular skin flap (2 × 8 cm2) was dissected from the muscular dorsal layer, preserving the cranial pedicle. Polyethylene film was placed over the muscular layer and an interrupted 3.0 nylon suture was employed to fix the flap into the original place. On the eighth day, full-thickness biopsy samples (2 × 1 cm2) were collected from the proximal, middle, and cranial areas of the skin flap, and in a site away from the flap labelled as the control area. Results: The measurements of necrotic areas in the groups were 18.3% in G-S, 24.3% in G-NAC, 12.6% in G-HBO, and 14.9% in G-HN. Significant difference was observed between the groups G-HBO and G-HN as well as G-NAC. Conclusion: HBO is associated with reduced area of necrosis of skin flap. The G-NAC group was associated with poor results when examined in isolation. The association between HBO and NAC did not produce favourable results with respect to the use of HBO alone. These findings suggest that the diffusion of oxygen through the interstitial space was the determining factor of more favourable results of HBO.

An experimental model to retraining in microvascular suture

PURPOSE To demonstrate an experimental model of up to four hours a week of independent study that allows relearning in microvascular sutures. METHODS Wistar rats between 200 and 500 grams surplus research experiments were used. Femoral vessels are covered on one or both sides through a groin incision obliquely along the inguinal ligament. Femoral artery and vein are isolated and measured being clamped and cut. The individual performs in microvascular anastomosis complexity arterial and venous terminoterminal sequence. terminolateral and venous and arterial grafts in vessels. Permeability is evaluated by testing vascular patency after creation of microvascular anastomosis. RESULTS In the first specimen, only arterial and venous vascular anastomosis are performed terminoterminal. The average diameter of the femoral veins varies from 0.8 to 2 mm between rodents (artery, between 0.6 and 1.4 mm, between 0.8 and 2 mm vein). The superficiality of the vessels allows faster dissection, may also be held in other inguinal region. CONCLUSION The model of individual retraining allows learning microvascular suture in individuals of permanent staff.

Efeito da oxigenação hiperbárica e da N-acetilcisteína na viabilidade de retalhos cutâneos em ratos

INTRODUCAO: Os avancos das tecnicas em cirurgia plastica permitiram a reconstrucao de extensos defeitos causados por ferimentos, entre as quais destaca-se a utilizacao dos retalhos randomicos. No entanto, o fator limitante para a utilizacao desses retalhos e a imprevisibilidade de sua vascularizacao distal, o que podera ocasionar danos irreversiveis a microcirculacao, resultando em necrose parcial ou completa do retalho, tornando a ferida mais suscetivel a infeccao. Portanto, melhorar a viabilidade do retalho randomico, principalmente em sua extremidade distal, tem sido uma meta importante para o sucesso dessa tecnica. O objetivo deste estudo foi investigar o papel da oxigenacao hiperbarica (OHB), da N-acetilcisteina (NAC) e da associacao de ambas (OHB + NAC) na area de necrose em retalhos randomicos modificados de McFarlane em pele de ratos Wistar. METODO: No total, 32 ratos Wistar machos foram divididos aleatoriamente em grupo Sham (GS, n = 8), grupo N-acetilcisteina (GNAC, n = 8), grupo oxigenio hiperbarico (GOHB, n = 8) e grupo oxigenio hiperbarico + N-acetilcisteina (GHN, n = 8). Sob anestesia geral, foi executado um retalho randomico modificado de McFarlane na regiao dorsal dos ratos. RESULTADOS: A necrose media foi de 18,3%, 24,3%, 12,6% e 14,9%, respectivamente, nos grupos GS, GNAC, GOHB e GHN. Os grupos GOHB e GHN apresentaram diferenca significativa quando comparados ao grupo GNAC. CONCLUSOES: A OHB esta associada a reducao da area de necrose do retalho cutâneo. A NAC foi associada a maus resultados quando usada isoladamente. A associacao dos dois procedimentos, OHB e NAC, nao potencializou os resultados favoraveis observados com o uso da OHB isoladamente. As descobertas sugerem que a difusao de oxigenio atraves do espaco intersticial foi o fator determinante de resultados mais favoraveis da OHB.

Reconstrução de lábio inferior pós-mordedura equina: descrição de técnica e revisão anatômica

BACKGROUND: The reconstructive surgery of the lip, upper or lower, presents a variety of techniques and procedures. In reconstructive surgery of lip is important to evaluate the characteristics of tissue (skin color, texture), which wherever possible should be used near the site of injury to provide the least morbidity and best tissues in colors and texture. CASE REPORT: This article aims to describe the Bernard-Burow technique for reconstruction of lower lip, and review the anatomy of the lower third of the face, through the case report of a patient who was bitten by a horse and had avulsion of lower lip and mentoniane portion of the face.

A gastrocnemius heterotopical transplant model with end-to-side neurorraphy

PURPOSE To present an animal model to assess the effects of end-to-side innervation in the heterotopically transplanted model with reduced chances of neural contamination. METHODS The medial portion of the gastrocnemius muscle in wistar male rats was isolated and its pedicle dissected and performed a flap in the abdominal portion. To prevent neural contamination in the abdominal region, the muscle was wrapped with a Goretex(r) sheet. The specimens were divided into 2 groups (G). In G1 was performed an end-to-end suture between tibial nerve of the gastrocnemius and femoral motor nerve and between the saphenous sensory nerve and the motor nerve. In G2 was performed a end-to-side suture between the tibial nerve and the motor femoral and between the tibial nerve and saphenous motor nerve. The specimens were evaluated 60 days later to check the structure of the neurorraphy. Sections were obtained proximal and distal to the coaptation site. RESULTS The medial gastrocnemius muscle had the advantage of maintaining visible mass after 60 days. No disruption of the coaptation site was found. No major injury to the donor nerve was seen in group 2. CONCLUSION The proposed model is simple, reproduciple and prevent the neural contamination in the flap in end-to-side suture.