Change in strength of aponeurotic tissue enclosed in the suture during the initial healing period. An experimental investigation in rabbits.

In order to ascertain whether tissue in which suture thread is inserted undergoes weakening, the strength against sutures in healing aponeurotic layer was determined in rabbits. The dorsal aponeurosis was used as test tissue. A paravertebral incision 10 cm long was made in it, and this was sutured with 00 (USP) multifil steel thread. The strength measured as holding strength against a single suture was noted 3, 5, 7, 10, and 14 days after the procedure. The contralateral aponeurosis was used as control in each animal, and was tested in identical fashion. Two series of experiments were carried out, one with loosely tensed thread (Series I) and one with tightly pulled sutures (Series II). In series I the strength on the experimental side was reduced by 10 percent (average) on the 3rd, 5th, and 7th days compared to the controls. Increase in strength was seen, however, from the 3rd to 14th days, and was significant (p less than 0.05). In series II the measured values showed significantly (p less than 0.05) lower strength on the experimental side compared with the controls throughout the 14-day period of the experiment. Moderate reduction in the strength of healing aponeurosis was thus recorded. The duration of this weakening depended on how tightly the suture loops were tied.