Application of Preserved Human Amniotic Membrane for Corneal Surface Reconstruction

Objective: To evaluate the efficacy of preserved human amniotic membrane transplantation for reconstruction of the corneal surface diseases. Methods: Preserved human amniotic membrane transplantations were performed in 84 eyes of 78 patients for corneal surface reconstruction. The indications were limbal stem cell deficiency from Steven–Johnson syndrome, chemical burn and herpes keratitis (27 eyes), bullous keratopathy (26 eyes), persistent epithelial defect and dellen (17 eyes), band keratopathy (11 eyes), preparing for prosthesis (1 eye), corneal ulcer (1 eye) and acute chemical burn (1 eye). Results: Success was noted in 83.3% (70/84) eyes, partial success in 13.1% (11/84) eyes, and failure in 3.6% (3/84) eyes for an average follow-up of 10.5 months (3 – 29 months). No patient developed major immediate post-operative complications. Conclusion: Amniotic membrane transplantation can reduce inflammation, promote corneal epithelial healing, and decrease irritation in corneal surface problems.     

The impact of the International Atomic Energy Agency (IAEA) program on radiation and tissue banking in Thailand

Tissue banking started in Thailand in 1979. Five years after this, the Bangkok Biomaterial Centre (BBC) was established in the Faculty of Medicine, Siriraj Hospital, with the support of the IAEA program. The objective of the Centre was to provide sterile bones and tissues for clinical use. Through the passage of time, the Bangkok Biomaterial Centre has gained confidence from the end user and by 2007 has processed 33,872 allografts from 491 deceased donors and 4,035 live donors were used in medical treatment in 3,596 patients in more than 79 different hospitals. More than 305 surgeons from Thailand used the tissue produced in the BBC. At the beginning of its work the BBC concentrate its activities on the production of the following tissues: freeze dried bone, freeze dried dura mater and freeze dried fascia lata. All of these tissues were sterilised using ethylene oxide gas until the end of year 1984. Since 1985 the BBC sterilise tissue using ionising radiation. The BBC is now producing deep-frozen; bone tendon, cartilage, trachea and soft tissue; freeze-dried; bone, fascia lata, dura mater, amniotic membrane, bone hydroxyapatite, bone tablet and fresh preserved amniotic membrane Yongyudh Vajaradul is a Founder of Bangkok Biomaterial Centre and also a President of TATB, Bangkok, Thailand. Jorge Morales Pedraza is a former IAEA Interregional Project Manager, Vienna, Austria.     

Long term follow-up of reconstruction with allogeneic mandibular bone crib packed with autogenous particulate cancellous bone marrow

Allogeneic mandibular bone processed by the deep frozen method was used as a biologic crib for mandibular reconstruction. The allogeneic mandible is biocompatible, bioresorbable, of low antigenicity and provides the morphology for symphysis contour, angle of mandible and dental arch form. The particulate cancellous bone marrow (PCBM) contains marked osteogenic potential of hematopoietic marrow, which promotes osteogenesis. The cancellous marrow graft lacks structure and requires a crib to house it during the bone regeneration to the consolidation phase. Fresh frozen mandible was hollowed out for packing with PCBM prior to securing it to the defect by a rigid fixation method. Four cases of large mandibular defects resulting from treatment of benign odontogenic tumors were reconstructed utilizing this technique. All cases showed excellent facial contour and function satisfactorily in mastication and pronunciation. Complete graft incorporation and restoration of the osseous continuities were observed for four to 12 years after the operation. This revised version was published online in July 2006 with corrections to the Cover Date.     

Ocular fixation with quadriceps tendon allograft

Management of difficult strabismus, such as strabismus fixus and paralytic strabismus, in order to maintain the alignment is complicated. There are many surgical approaches described in the current literature, together with notes on the materials used to stabilize these deformities. We present a new surgical approach using quadriceps tendon allograft for the correction of difficult strabismus such as strabismus fixus and paralytic strabismus. Our idea for using deep frozen quadriceps tendons developed from the fact that this is the most stable and strongest tendon in the whole body. Six patients with strabismus fixus (n = 1), paralytic strabismus secondary to extraocular muscle damage (n = 1) and combined cranial nerve palsy (n = 4) were operated on using a strip of deep frozen quadriceps tendon allograft suturedonto both the globe and the periosteum. The mean age of the patients was 44.33years. (range 17–71 years) All the patients were followed up for six months. The mean preoperative deviation in the six cases was 60 prism diopters(PD) (range 30–123 PD) The mean change in horizontal alignment at 1 month, 3 months and 6 months postoperatively was 54PD, 53 PD and 49.16 PD respectively. We had only one case of under correction. This may possible be due to the remaining function of the antagonist and/or the fact that we had used the distal end of the quadriceps tendon. When the patient (patient No. 5) who had 2 operations was excluded, the mean change in horizontal alignment was 48.6 PD,47.4PD and 43.6 PD. Post-operatively there was no infection or any other complications. According to our study of existing literature, these cases of deep frozen quadriceps tendon allograft application for the indications mentioned above are the first reported cases of its type. We conclude that ocular fixation with quadriceps tendon to the periosteum is a safe and effective option for the management of difficult strabismus. Further research on a larger cohort of patients and longer follow-up time are needed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Bangkok Biomaterial Center: 15 Years Experience in Tissue Banking

Tissue banking is started in Thailand in 1979 at the Department of Orthopaedic Surgery, Siriraj Hospital, Bangkok. At that time tissues produced were freeze-dried bone allografts which were sterilized by ethylene oxide. In 1984, the freeze-dried tissue allograft project received an award from the National Research Council of Thailand. The Bangkok Biomaterial Center was officially inaugurated on December 6, 1984 under the Royal Patronage of H.R.H. Princess Galyanivadhana and is located inside the Siriraj Hospital. The Center is involved in the procurement, processing, storage and development of bone and tissue allografts. A variety of allografts including bone, cartilage, fascia lata, dura mater, cornea and also cardiovascular tissues have been procured and processed. Preservation and long-term storage are accomplished by freeze drying and deep freezing. Grafts prepared by the Center are supplied free of charge at the request of surgeons in hospitals throughout Thailand and in neighboring countries. The Center acts as the National Tissue and Allograft Bank of Thailand. From December 1984 to February 2000, the Center has processed a total of 20524 allografts: 16981 freeze-dried bones, 705 deep-frozen bones, 1838 freeze-dried amnion, 559 freeze-dried dura mater, 342 freeze-dried fascia lata, 46 costal cartilage, 18 corneas, 2 skin, 5 trachea, 22 fresh tendon and 6 bone substitutes. The allografts processed were used in 2049 patients by 223 surgeons in 53 hospitals in Thailand and 4 cases in neighboring countries. There have been 413 cadaveric donors, 619 living donors, 16 brain dead donors and 270 graveyard donors. There have been complications in 126 patients (6.14%) due to various clinical conditions. There have been production and application of 4 hydroxyapatite occular implant by the Center. The Center is in the process of establishing a full-fledged Research, Clinical and Cell Culture Laboratory.     

The future role of the professional associations in the promotion of tissue banking activities in Asia and the Pacific and in the Latin America regions

There are several important roles that the established professional associations [Asia-Pacific Association of Surgical Tissue Banking (APASTB) and Latin American Association of Tissue Banks (ALABAT)] could play for the promotion of tissue banking activities in Asia and the Pacific and in the Latin American regions in the future. The International Atomic Energy Agency (IAEA) and the World Health Organisation (WHO) could also play an important role in supporting the activities of both professional associations in the field of training, exchange of scientific information, the standardisation of national norms and regulations, the use of the IAEA documents, particularly the “Radiation Sterilisation of Tissue Allografts: Requirements for Validation and Routine Control. A Code of Practice”, with the purpose to improve the quality of the activities carried out by the established tissue banks and the nuclear facilities in charge of the sterilisation of the processed tissues, and to increase tissue donations. The role of APASTB and ALABAT could be relevant and important for the improvement of the work of the established tissue banks in Asia and the Pacific and in the Latin American regions, and could increase the effectiveness and efficiency of their works, the improvement of management good practices and for increasing the awareness of the community on the importance of the activities carried out by the tissue banks, among others.