Diode laser photoablation to correct distal nasolacrimal duct atresia in an adult horse.

CASE DESCRIPTION: An 8-year-old Hanoverian mare was presented for chronic mucopurulent discharge in the left eye, which was responsive to topical antibiotic therapy. CLINICAL FINDINGS: The nasolacrimal orifice was absent in the left nasal meatum, and anterograde irrigation of left nasolacrimal duct was not possible. Dacryocystorhinography was performed and revealed about 4-6 cm of distal nasolacrimal duct atresia. SURGICAL TREATMENT AND OUTCOME: A novel technique was attempted with the horse under standing sedation using an urinary catheter and a 980 nm diode laser with a 600 µm diameter flexible bare quartz fiber. A nasolacrimal orifice was successfully created by ablating the nasal mucosa directly over the tip of the urinary catheter, and patency was maintained with a soft catheter sutured in place for 4 weeks. At 3 months re-evaluation, the left nasolacrimal duct was patent and functional. CONCLUSION: This case report describes a successful novel surgical technique used to correct congenital distal nasolacrimal duct atresia in an adult horse under standing sedation. Advantages over conventional surgical techniques are shorter operating time and limited hemorrhage.

Conditioned medium from horse amniotic membrane-derived multipotent progenitor cells: immunomodulatory activity in vitro and first clinical application in tendon and ligament injuries in vivo.

We have recently demonstrated that heterologous transplantation of horse amniotic membrane-derived mesenchymal cells (AMCs) can be useful for cell therapy applications in tendon diseases, and hypothesized that these cells may promote tendon repair via paracrine-acting molecules targeting inflammatory processes. To test this hypothesis, here we examined the immunomodulatory characteristics of AMCs and of their conditioned medium (AMC-CM) in vitro, and studied the potential therapeutic effect of AMC-CM in thirteen different spontaneous horse tendon and ligament injuries in vivo. Our results demonstrate that AMCs are capable of inhibiting peripheral blood mononuclear cell (PBMC) proliferation after allogenic stimulation either when cocultured in cell-to-cell contact, or when the two cell types are physically separated by a transwell membrane, suggesting that soluble factors are implicated in this phenomenon. Our hypothesis is further supported by the demonstration that PBMC proliferation is inhibited by AMC-CM. In our in vivo studies, no significant adverse effects were observed in treated tendons, and clinical and ultrasonographical evaluation did not reveal evidence of inappropriate tissue or tumor formation. Clinical outcomes were favorable and the significantly lower rate (15.38%) of reinjuries observed compared to untreated animals, suggests that treatment with AMC-CM is very efficacious. In conclusion, this study identifies AMC-CM as a novel therapeutic biological cell-free product for treating horse tendon and ligament diseases.

Investigating the efficacy of amnion-derived compared with bone marrow-derived mesenchymal stromal cells in equine tendon and ligament injuries.

BACKGROUND AIMS: This is the first study to compare the treatment of horse tendon and ligament injuries with the use of mesenchymal stromal cells (MSCs) obtained from two different sources: amniotic membrane (AMSCs) and bone marrow (BM-MSCs). The objective was to prove the ability of AMSCs to exert beneficial effects in vivo. METHODS: Five million allogeneic frozen-thawed AMSCs or autologous fresh BM-MSCs were injected intralesionally in horses belonging to group A (51 horses) and group B (44 horses). The interval lesion/implantation was of 6-15 days for the AMSCs and 16-35 days for the BM-MSCs. Healing was assessed clinically and ultrasonographically. Follow-up was monitored for 2 further years from return to full work. RESULTS: No significant adverse effects after MSCs treatment were seen in any of the horses studied, independent of the type of stromal cell implanted. All animals belonging to group A resumed their activities between 4-5 months after treatment, whereas animals of group B resumed their activities after 4-12 months. The rate of re-injury in horses treated with AMSCs is lower (4.00%) compared with the average observed when horses were treated with BM-MSCs (23.08%). CONCLUSIONS: The possibility to inject allogeneic AMSCs in real time, before any ultrasonographic change occurs within the injured tendon and ligament, together with the higher plasticity and proliferative capacity of these cells compared with BM-MSCs, represents the main features of interest for this novel approach for the treatment of equine tendon diseases. An obvious active proliferative healing in the area injected with AMSCs makes these cells more effective than BM-MSCs.