RESUMO
Aim: The aim of this study was to compare two tubulization techniques, inside-out veins and standard veins, both filled with skeletal muscle or not, in sciatic nerve by morphological and histomorphometric study. Methodology: Seventy Wistar rats were divided in 4 experimental groups (IOVNF - inside-out vein with no filling; IOVSM - inside-out vein filled with skeletal muscle; SVNF - standard vein with no filling; and SVSM - standard vein filled with skeletal muscle) and a control group (Sham). The left external jugular vein was sectioned into about 14 mm segments to be used as autologous vein grafts. A 10 mm gap was then created in the sciatic nerve and the vein graft was inserted into the vein with or without filling of the right caudal tibial muscle. The animals were euthanized 12 weeks after surgery. Results: Myelinated and unmyelinated nerve fibers were observed in the histological analyses for all groups, as well as neoformation of the perineurium and intraneural organization of fascicles and blood vessels. In the morphometric analysis of the distal stump, regarding the myelin sheath area, all groups had a significant difference. The IOVNF group had the highest means for fiber, axon and myelin sheath areas. The SVSM group had the lowest means in all features measured, except for the axon area (4.95±1.72 graft; 3.71±0.90 distal stump). Conclusion: These results show that sciatic nerve repair with inside-out veins and no filling (IOVNF) had the best results, in the majority of measured variables, when compared to the other groups.
RESUMO
End-to-end conventional arterial anastomosis is time consuming, requires prolonged clamping times and is associated with focal necrosis, granulocyte infiltration and subsequently, fibrosis and calcification of the arterial wall. Fibrin glue as an alternative for microarterial anastomosis may obviate these lesions, with less adherence to adjacent tissues and better coaptation of the arterial margins. OBJECTIVE: In this study we compared the healing process of conventional to fibrin glue end-to-end anastomosis in larger arteries. METHODS: In 22 rabbits, both carotid arteries were cross sectioned and repaired by end-to-end anastomosis with 4 interrupted sutures and fibrin glue in one side (GI) and with 8 conventional interrupted sutures in the other side (G2). After 3 and 15 days, the animals were randomly allocated for tensile strength, hydroxyproline determination (8 animals), and histologic analysis of the anastomosis (3 animals). Conventional staining procedures (hematoxylin-eosin and Masson methods) and picrosirius red polarization (PSP) technique for collagen type determination were employed. RESULTS: From 3 to 15 days, the tensile strength increased in both groups, from 280.0ñ 32.6 g to 432.2ñ 131.2g in Group I and from 221.4ñ 72.4g to 452.2ñ 132.0g in Group 2 (p<0.001), with no statistical difference between the groups in each period of the study. The hydroxyproline content, expressed as hydroxyproline /protein ratio, varied from 0.0816 ñ 0.0651 to 0.0622 ñ 0.0184 in Group l and from 0.0734 ñ 0.0577 to 0.0460 ñ 0.0271 in Group 2, with no significant difference between periods and groups (p>0.05). Histology showed slight increase of inflammatory and reparative reactions in Group 2. PSP technique demonstrated predominant type I collagen in relation to type III collagen in the anastomosis of both groups, with no significant difference between them. CONCLUSION: Fibrin glue was less harmful to the arterial wall than conventional suture. Even using less sutures in fibrin glue anastomosis, similar tensile strength and healing characteristics were noted in both groups. Completion times for the fibrin glue group was significantly greater than for the conventional anastomosis.