RESUMO
The current approach to flexor tendon injuries is complex and is no longer limited to suturing techniques. Strategies for improving hand function currently include rehabilitation protocols, appropriate suturing materials and techniques, changing the gliding surface by using lubricants and providing growth factors. One product, originally used in spinal surgery, has been shown to be effective in preventing postoperative adhesions. It is a combination of carboxymethylcellulose and polyethylene oxide-Dynavisc® (FzioMed, Inc.). The aim of the present study was to test the effect of Dynavisc® on acute injuries of the intrasynovial flexor tendons in the prevention of postoperative adhesions and the improvement of functional results. The study was performed on 20 Wistar rats distributed in two groups. The control group, represented by 10 rats, in which after the reconstruction of the flexor tendon, the peritendinous area was injected with saline solution and the study group, in which the peritendinous area was injected with a single administration of the lubricating gel, Dynavisc® (carboxymethylcellulose and polyethylene oxide). At 4 and 12 weeks, the rats were sacrificed and tissue biopsy consisted of tendon fragments and adjacent tissue. The evaluation of the results was performed by measuring the adhesion score and observing histological parameters. The presence of important adhesions was found in the control group compared with the group treated with Dynavisc®, where a supple and smooth tendon, with significantly fewer adhesions were found. The differences between the two groups were significant, thus indicating the efficiency of the lubricant in preventing adhesions. This study supported the important role of Dynavisc® in the regeneration of the tendon and the peritendinous structures, by limiting aberrant fibrous proliferation in the regeneration process and helping to build a peritendinous space.
RESUMO
Autologous fat transfer is widely used by plastic surgeons for aesthetic and reconstructive purpose, but it has a great disadvantage because of its high variability rate of resorption. Numerous studies have examined the use of different agents to increase the viability of fat grafts. The results were discouraging because the use of a single angiogenic factor to stimulate fat graft angiogenesis may be inappropriate. We proposed to use two pharmacological factors, erythropoietin (EPO) and insulin (INS), in order to decrease the resorption rate, to improve graft vascularization, and to reduce the number of complications. Twenty-four Wistar male rats were randomly divided in four groups (I-IV) of six animals each. The rats belonging to control group were given autologous transfer of simple fat. In group II, the graft was improved with EPO, in group III with INS, and in group IV both pharmacological agents were administered. Histological evaluation of the grafts at two months after injection demonstrated adipocyte survival in all four groups. The volume of the graft has progressively decreased in all groups and the difference in graft volume at one and two months after transplantation was not significant. The highest maintenance of fat graft volume (95%) at two months was observed in group IV, followed by group II and group III. Necrotic cystic changes and increased fibrosis were most extensive in the control group. The combination of INS with EPO may have a synergistic and additive effect. Efficient administration and dose optimization of these growth factors are important things to consider in the future.
