Effects of aging on abdominal wall healing in rats

Maria De Lourdes Pessole Biondo-Simões,Sergio Ossamu Ioshii,Janaína Weingärtner,Karin Soldatelli Borsato,Oreste Terranova,Patrícia Longhi,Gustavo Nogueira

doi:10.1590/s0102-86502005000200005

Abstract

The aim of this study was to assess abdominal wall healing in old and young adult rats. On average, young animals were 110 days old and old animals were 762 days old. A 4.0 cm median laparotomy was performed under anesthesia, followed by laparorrhaphy on two synthesis planes, i.e. peritoneum-muscle-aponeurosis and skin, using continuous 5.0 nylon sutures. The animals were evaluated on the 3rd, 7th, 14th and 21st postoperative days. The resistance of the two planes was studied separately and a histopathologic analysis was performed on sections stained with hematoxylineosin and Sirius Red. Immunohistochemical analysis was also carried out using PCNA, LCA and CD34. The skin scars gained resistance in a similar manner at the initial time points, but those of young rats were more resistant on the 21st day (p=0.0029). Total and type III collagen content was similar in the two groups and type I collagen content was higher in young animals on the 14th day. Inflammatory cell infiltration was more marked in the skin wounds of young animals on the 3rd day (p=0.0190). Reepithelialization was similar and angiogenesis was more intense in the skin wounds of young animals on the 14th day (p=0.0062). The peritoneum-muscle-aponeurosis wounds gained similar resistance during the early phases, but were more resistant on the 14th day (p=0.0005) and on the 21st day (p=0.0023) in old rats Collagen concentration was higher in the wounds of old animals on the 3rd day (p=0.0112) and in the wounds of young animals on the 21st day (p=0.0348). The inflammatory reaction was more intense in the wounds of old animals on the 3rd day (p=0.0060) and angiogenesis was more intense on the 14th day (0.0432). Although there are some differences in the healing course between young and old animals, age, of itself, does not impair the healing of abdominal wall wounds in rats.

Highlights

MethodsMedical advances have led to a better understanding of the health-disease diad and technological advances have permitted more precise diagnoses and more efficient treatments
Some investigators have stated that age is not a factor predisposing to complications[4], whereas others have demonstrated that the complications occurring in older patients definitely lead to higher morbidity and mortality rates[3,5,6,7,8,9]
One partial dehiscence of the PMA scar was observed in the old group on the 14th day (p=0.5000)

Summary

Introduction

MethodsMedical advances have led to a better understanding of the health-disease diad and technological advances have permitted more precise diagnoses and more efficient treatments. When elderly patients are submitted to surgical procedures, physicians and relatives are concerned about the possible complications. Some investigators have stated that age is not a factor predisposing to complications[4], whereas others have demonstrated that the complications occurring in older patients definitely lead to higher morbidity and mortality rates[3,5,6,7,8,9]. Mendoza Jr et al[10] howed that elderly patients had a 5fold higher chance to experience wall dehiscence than young patients[10]. Riou et al[11] reported 31 cases of wall dehiscence among 2761 patients and compared these patients to 38 other ones who had been submitted to similar operations. They cited age older than 65 years

Objectives

Results

Conclusion