Autologous Venous Grafting Promotes Healing and Reduces Adhesion Formation in Experimentally Severed Canine Superficial Digital Flexor Tendons

The objectives of this study were to evaluate healing of experimentally severed superficial digital flexor tendons of the canine hind limb repaired by apposition using a Kessler pattern with no augmentation, or augmentation with an everted autologous venous graft or non-everted autologous venous graft. A total of 30 healthy, orthopaedically and neurologically sound mongrel dogs were used in this study. Dogs were randomly allocated into one of the three groups: control group (GC): the severed tendon was repaired with Kessler technique only and no grafting, GNEv: the severed tendon was repaired using Kessler technique and “non-everted venous graft” and GEv: the severed tendon was repaired with Kessler technique and “an everted venous graft”. Post-operatively, at day 42, the site of surgery was evaluated grossly and histologically. In the control group, 30% of dogs showed no healing of the severed tendon. Both types of venous grafts (“everted” and “non-everted”) resulted in improved fibroblastic proliferation at the site of injury. The amount of adhesion appeared significantly less in grafted sites compared to non-grafted tendons. When compared between the 2 types of venous grafts, the adhesion formation appeared to be less pronounced in GEv group than that in GNEv group. Autologous venous grafts appear to significantly improve fibroblastic proliferation and reduce adhesion tissue formation particularly when utilising “everted autologous venous graft”. These results might suggest a beneficial effect when utilising venous grafts along with the traditional treatment procedure of severed digital flexor tendons in dogs.