The keratoxeno graft as a medical product is the cryolyophilized tissue substrate of a porcine cornea designed for surgical keratoplasty.
significant purulent discharge.
The principle of therapeutic action:
The mechanical closure of the recipient cornea and stimulation of its regeneration.
Pathology of the cornea is one of the leading causes of blindness and vision disorders.
Most lesions of the cornea result from traumas and burns, which belong to the most complicated pathology of the eye. According to WHO data, it is one of three main factors of vision loss which makes up from 6.6% to 39.3%. In particular, the corneal injuries in people of working age in the structure of primary disability make up 29%, and the frequency of eye burns, according to different authors, range from 6.1% to 38.4% of all types of ocular injuries.
The traditional technologies of the conservative treatment of traumatic ocular injuries and corneal ulcers do not always provide a positive effect that is often associated with impaired reparative-regenerative processes that lead to corneal perforation and eye loss. Therefore, corneal pathology often requires urgent surgical intervention, especially in progressive lysis and the risk of the perforation of the cornea membrane. Accordingly, the adequate treatment of patients with ocular injuries and ulcerative keratitis is an actual medical, social and economic problem.
One of the main ways of treating patients with ocular injuries and ulcerative keratitis is keratoplasty. Taking into account the high regeneratory capacity of the corneal tissue, most clinicians tend to believe in the benefits of the surgical treatment of these patients on the basis of the N. Puchkivska fundamental biological coverage (1985) which requires different donor materials such as cornea, sclera, dura mater, fascia, amnion etc. While the cornea transplanting as the most common current transplantation technology is known for about a hundred years, the difficulties in its implementation still make up the essence of scientific and practical problems of modern ophthalmology. These problems include ensuring a high-quality donor material, immunological incompatibility of graft tissues and the host organism etc. Moreover, the sharp increase in traffic, industrial and domestic accidents, disturbances of the ecological balance in the biosphere, high occurrence of ocular injuries, problems of legal support in obtaining materials for allogeneic keratoplasty have lead to the deficit of donor material.
We have proposed to use the porcine cornea – the cryolyophilized Keratoxeno grafts for therapeutic and tectonic keratoplasty (NV Pasyechnikova, S. Yakimenko, M. V. Turchin). The positive long-term experience of clinical application of cryolyophilized Keratoxeno grafts to treat the burn patients is considered when developing the technologies of porcine cornea conservation and preservation (V. Bihunyak, 1985-2010).
The production of cryolyophilized Keratoxeno grafts is made on the technology developed jointly by I. Ya. Horbachevsky Ternopil State Medical University, V.P.Filatov Odessa Institute of Eye Diseases and Tissue Therapy as well as the Academy of Medical Sciences of Ukraine (Pat. 52278 U, 2010). The procedure is performed by removing the porcine cornea, its processing with a cryoprotector under the right conditions, preservation at cryogenic temperatures (-196 ° C), vacuum drying, product packaging following by radiation sterilization. Cryolyophilized Keratoxeno grafts are registered by the Ministry of Health of Ukraine as a medical product; it is stored in a special sealed box (the state registration №9967\2010) and is allowed to be used in medical practice.
The preparation of a keratoxeno graft for surgical intervention – therapeutic keratoplasty
1 hour before the surgery a dry keratoxeno graft is removed aseptically and antiseptically from a polyethylene pack and immersed in sterile isotonic sodium chloride solution for 50-60 min at 18-20ºC. After the maceration, the wet keratoxeno graft is shaped fitting the size of the patient cornea.
The extra sclera tissue is cut off circularly with the scissors, leaving the four protrusions (approximately for 12, 3, 6 and 9 hours), with the width 2-2.5 mm, 1-1.5 mm for suturing the graft to the eye sclera (if necessary, you can leave the scleral ring of the required width). The suitable disk of a keratoxeno graft is cut for the partial trepan coverage.
The blepharostat and traction suture are put the superior direct muscle after standard processing of the surgical field. Local epibulbar anesthesia: Sol. Alcaini 0,5%; local subconjunctival anesthesia Sol. Lidocaini 2%. Then, the conjunctiva is separated from the limb and the prepared keratoxeno graft is put over on the cornea of the injured eye and sutured to the sclera by the limb with seams 7,0-8,0 for 12, 3, 6 and 9 hours. The conjunctiva is fixed by two sutures to cover the keratoxeno graft peripherally.
The antibiotic solution is dropped in the conjunctival cavity and the antibacterial ointment is applied. Then the blepharostat and traction suture are removed and the monocular aseptic bandage is put on the eye.
The antibiotics and sulfanilamide drugs e.g. non-steroid eye drops are prescribed in the postoperative period. The general anti-inflammatory therapy is prescribed depending on the eye condition. The patients are supervised after the discharge from hospital by an ophthalmologist until the complete keratoxeno graft resorption and healing of a corneal. The implanted keratoxeno graft completely resolves in 2 to 3 months.
Thus, keratoplasty with Keratoxeno grafts using cryolyophilized porcine corneas provides the closure of the corneal defect followed by epithelialization, reduction and elimination of inflammation, restoration of the anatomic integrity of the patient cornea.
The surgical intervention – Ulcer Keratoplasty
The eye before the operation: the corneal ulcer with a perforation in the centre
The eye after the operation: the cornea is covered with a keratoxeno graft. Fixation with 4 U-shaped sutures to the sclera. Hyperaemia, subconjunctival hemorrhage
1 day after the surgery: - slight hyperemia, residual effects of conjunctival hemorrhage
8 day: increased swelling of a xenoderm graft, opacity phenomenon of a xenoderm graft
60 day: clear boundaries of a cataract. Remains of a xenoderm graft