Effect of papaverin on tendon healing and adhesion in rats with achilles tendon repair (Experimental study)

Tendon injuries are common and despite current techniques, damaged tendons heal slowly and rarely preserve the structural integrity and mechanical strength of a healthy tendon. This often results in clinical difficulties and a burden to the patient, family, and society. The Achilles tendon, which is also the strongest tendon in the body, is most commonly injured. Papaverine is a vasodilating phosphodiesterase inhibitor opioid analog drug. In our study, Papaverine was applied systemically and locally on 48 rats by repairing the Achilles tendon in the right lower extremity. On the 15th and 30th days, a histopathological examination was performed with the Soslowsky, Svensson, and Cook criteria for half of the samples taken, and the other half was subjected to the biomechanical tensile test. Considering the early results of the 15th day histopathologically, no significant difference was observed between the groups. Considering the 30th-day late period, the local Papaverine group was found to be significantly superior to the control group in terms of Cellularity, Cartilage Formation, and the Total Score (p<0.05). There was no difference between the groups in terms of adhesion. As a result of the biomechanical analysis, in terms of the highest strength values before rupture, local Papaverine in the early period and both systemic and local Papaverine in the late period showed statistically significant superiority compared to the control group (p<0.05). When the maximum stress values of the samples were examined, a significant superiority was observed in both groups, with better average values in the local Papaverine group in the early period, while a significant difference was observed only in the local Papaverine group in the late period (p<0.05). Considering the data obtained and especially the correlation of late histopathological and biomechanical data, we believe that locally applied Papaverine will have a positive effect on tendon healing.