End-to-end arterial anastomosis with fibrin glue in larger arteries: histology, hydroxyproline concentration and tensile strength study in carotids of rabbits

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.

The relationship between suture number and the healing process of end-to-end arterial anastomosis

In spite of the great experience accumulated in vascular repairing, the ideal number of sutures required for vascular anastomosis remains controversial. It is generally thought that the more stitches applied in a vascular anastomosis, the lesser resistant the anastomosis will be. The purpose of this study was to test this hypothesis in 20 rabbits, in which both carotid arteries were cross sectioned and repaired by end-to-end anastomosis with 8 interrupted sutures in one side (G1) and 16 in the other side (G2). After 3 and 15 days, the animals were randomly allocated for tensile strength, hydroxyproline determination (7 animals) and for histologic analysis of the anastomosis (3 animals). Conventional staining procedures (hematoxylin-eosin and Masson methods) and the picrosirius red polarization (PSP) technique for collagen type determination were used. From 3 to 15 days, the tensile strength increased in both groups, from 265.0 + 44.4g to 391.2 + 49.0g in G1 and from 310.0 + 71.5g to 348.7 + 84.0g in G2 (p<0.005), with no statistical difference between the groups in each period of study. The hydroxyproline content, expressed as hydroxyproline/protein ratio, varied from 0.04 + 0.01 to 0.05 + 0.02 in G1 and from 0.05 + 0.01 to 0.05 + 0.02 in G2, with no significant difference between periods and groups. The histology showed similar inflammatory and reparative aspects in both groups. In both groups and periods the PSP technique demonstrated predominantly type I collagen in relation to type III collagen in the anastomosis. We concluded that even doubling the number of stitches, the healing process and the strength did not change in the arterial anastomosis.

Açäo do diclofenado de sódio em anatomoses realizadas no cólon distal de ratos / Action of sodium diclofenac on the colon anastomosis healing in the rat

Este trabalho avaliou a açao do diclofenaco de sódio (DS) na cicatrizaçao de anastomoses realizadas no cólon distal de ratos, tendo analisado a evoluçao clínica, resistência mecânica, colágeno tecidual e alteraçoes histopatológicas. Foram utilizados 266 ratos Wistar divididos em 4 grupos experimentais; o Grupo 1, laparotomia; Grupo 2, anastomose no cólon distal; o Grupo 3, laparotomia e DS, na dose de 3 mg/Kg de peso por dia, IM, por 4 dias e o Grupo 4 submetido à anastomose do cólon distal e DS administrado de maneira idêntica ao grupo anterior. Os parâmetros foram analisados no 4 , 7 , 14 e 21 dias de pós-operatório. Os animais do grupo 1 nao apresentaram alteraçoes clínicas durante o período de acompanhamento. No Grupo 3, 15 por cento dos animais apresentaram diarréia, diminuiçao do colágeno tecidual e da força de ruptura. Entre os animais submetidos à anastomose do cólon, observou-se taxa de mortalidade maior nos animais que receberam DS, além de retardo na cicatrizaçao caracterizada por uma maior reaçao inflamatória polimorfonuclear, retardo na regeneraçao da mucosa, diminuiçao de macrófagos e do colágeno tecidual. Pelos resultados obtidos conclui-se que o diclofenaco sódico é deletério à evoluçao cicatricial de anastomoses realizadas no cólon distal de ratos.