An improved method of in vivo wound disruption and measurement

Biomechanical studies of wound strength are important because of new investigations in growth factors, cytokines, and fetal wounds. We compared two traditional methods of wound disruption measurement with a novel computerized model designed for in vivo experiments. An Instron tensiometer (INSTS) and an air insufflated positive pressure device (AIPPD) were compared with a vacuum-controlled wound chamber device (VCWCD). The VCWCD produced vacuum at the wound site and wound disruption was monitored with two video camera/recorders. Rats were marked with a template guide for a 2.5 cm, full-thickness, abdominal incisional wound. Rats were divided into three groups and studied at 2, 7, or 14 days after wounding. The recorded images were computer digitalized to generate wound strength curves from a three-dimensional model. A comparison of the wound disruption curves demonstrated that the VCWCD was comparable to the INST or AIPPD in normal wound healing (P greater than .40). The VCWCD provided data with less standard error at 2 days after wounding (P less than 05). In separate series of experiments, VCWCD was tested in the early phases of healing and was found to be sensitive to change at intervals of 48 hr after wounding (P less than .005). The INST or AIPPD methods could not perform this task because of an unacceptable level of random error after tissue manipulation. The VCWCD system was considered superior for evaluating early wound healing because it was an in vivo method which required minimal wound manipulation.