1/5. osteoradionecrosis of the mandible after oromandibular cancer surgery.Although postoperative radiotherapy has proved effective in improving local control and survival in patients with head and neck cancers, its complications, especially mandibular osteoradionecrosis, reduce the quality of life. Mandibular surgery before the radiotherapy adds an additional risk factor for osteoradionecrosis. This study reviews patients in Chang Gung Memorial Hospital, Taipei, taiwan, over a 10-year period, who underwent intraoral cancer resection followed by postoperative radiotherapy and thereafter developed osteoradionecrosis of the mandible. A total of 24 men and three women with a mean age of 49.9 years were identified and included in the study. In 10 cases, tumor resection was performed with a marginal mandibulectomy; in eight cases, tumor resection was performed after mandibular osteotomy; and in three cases, a segmental mandibulectomy was performed, and the defect was reconstructed with a fibula osteoseptocutaneous flap. In six cases, tumor excisions were performed without interfering with the mandibular continuity. patients received postoperative external beam radiotherapy into the primary site and the neck, with a mean dose ( /-SD) of 5900 /- 1300 cGy in an average of 35 fractions during an average of 6.5 weeks. The average elapsed time between the end of radiation therapy and clinical diagnosis of osteoradionecrosis of the mandible was 11.2 months (range, 2 to 36 months). The time elapse between the end of the radiation therapy and the diagnosis of osteoradionecrosis was influenced by initial treatment (Kruskal-Wallis test: n = 27, chi-square = 12.884, p < 0.005), and this period was shorter if the mandibular osteotomy or marginal mandibulectomy was performed (the two lowest mean ranks in the test). However, if the initial surgery resulted in a segmental mandibulectomy reconstructed with a fibula osteoseptocutaneous flap, onset of the osteoradionecrosis was relatively late (Kruskal-Wallis test: n = 21, chi-square = 7.731, p = 0.052). After resection of osteoradionecrotic bone and surrounding soft tissue, 22 patients underwent reconstructive procedures with a fibula osteoseptocutaneous flap, and five patients underwent reconstructive procedures with an inferior genicular artery osteoperiosteal cutaneous flap. One fibula osteoseptocutaneous flap showed total failure and another showed a 25 percent skin loss; both were revised with pedicled flaps. The skin paddle of an inferior genicular artery flap was replaced with an anterolateral thigh flap because of anatomic variation of the skin vessel. Once the diagnosis of osteoradionecrosis is established, replacement of the dead bone and surrounding tissue with a vascularized free bone flap is inevitable, and a composite osteocutaneous free flap is a good option.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
2/5. osteoradionecrosis, pathogenesis, treatment and prevention.The present paper discuss the development of osteoradionecrosis (ORN) in the jaws. ORN is the end stage of tissue injury induced by irradiation. The most prominent etiologic factor of ORN seems to be the effect of radiation on endothelial cells lining the vessels. These cells are, as tumor cells, highly radiosensitive, and radiation leads to a vascular damage resulting in hypoxic, hypovascular and hypocellular tissues. wound healing in such tissues is impaired since nutritional demands of the wound, including oxygen, cannot be supplied due to the degenerative changes in the blood vessels. The paper furthermore describes the scientific basis for the use of hyperbaric oxygen therapy (HBO) in ORN. HBO increase the vascularity in the tissues injured by radiation, and thus tissue viability and healing capacity is increased reducing the risk for spontaneous or traumainduced ORN. Protocols for the treatment of patients with ORN are presented and prophylactic guidelines are described.- - - - - - - - - - ranking = 2keywords = vessel (Clic here for more details about this article) |
3/5. Delayed excision of a defect after free omental transfer with uncertain viability; a case report.We present the case of a 45-year-old man with an extensive radionecrotic ulcer of the anterior aspect of the thigh and exposure of the femur. Difficulty in the revascularisation of a free omental transfer due to radiation damage to the recipient vessels led us to delay excision of the defect and to store the flap temporarily in a plastic bag close to the recipient site; 48 hours later its satisfactory appearance allowed excision of the defect and successful final inset of the omentum. Advantages of this procedure are discussed.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
4/5. Major mandibular reconstruction with vascularized bone grafts: indications and selection of donor tissue.Free vascularized bones have been shown by many specialists to exhibit specific capabilities of reconstructing a major mandibular defect and can solve problems that may be insoluble by other methods. Nevertheless, absolute indications for using vascularized bone for major mandibular reconstructions have not been sufficiently well delineated to convince people of always considering vascularized bone for major mandibular reconstructions as a first option. Based on our experience with 55 major mandibular reconstructions, we might delineate the absolute indications for using free vascularized bone for major mandibular reconstructions explicitly: 1) osteoradionecrosis of mandible or on irradiated tissue bed; 2) hemimandibular reconstruction with a free end facing the glenoid fossa; 3) long segment mandibular defect, especially across the symphysis; 4) inadequate skin or mucosal lining; 5) defects demanding sandwich reconstruction; 6) inability to obtain secure immobilization on the reconstructed unit; 7) failure of reconstruction by other methods; 8) near total mandibular reconstruction. Selection of donor tissue should be according to 1) the amount of tissue deficiencies, 2) composition of the defect, 3) design and placement of the flap, 4) irradiation on the recipient site or not, 5) which vessels to be used, 6) which flap has the appropriate vessel length 7) skin color and texture of the donor tissue, 8) how many osteotomies required to stimulate the curvature of the resected mandible 9) speed of bony union, 10) feasibility of future osseointegration. We have used three kinds of vascularized bones (iliac bone, fibula, scapula). Iliac bone was most frequently used, and has always been our first choice, since it can carry good quality bone, a large skin flap, and ample soft tissue. The fibula has the merit of being less bulky and good for simultaneous intraoral lining, but the contour is more rigid and the bony height is insufficient. The scapula bone is rarely used at present because of its relative inconvenience.- - - - - - - - - - ranking = 2keywords = vessel (Clic here for more details about this article) |
5/5. Selection of appropriate recipient vessels in difficult, microsurgical head and neck reconstruction.In a series of 327 cases of head and neck microsurgical reconstruction during 22 years beginning in 1974, the authors have reviewed 16 cases in which the first choice of recipient vessels was not available. The problems of selecting alternative and appropriate recipient vessels are discussed. Recipient vessels could be classified into three groups: adjacent small vessels that are usually considered to be the first choice; major vessels; and distant vessels. A correlation between the selection of substitute vessels and the region of reconstruction was found. Representative cases in each category are presented. In difficult cases in freeflap transfer, it is of prime importance to select healthy recipient vessels. Additionally, special precautions, including choice of anastomotic technique, are required.- - - - - - - - - - ranking = 12keywords = vessel (Clic here for more details about this article) |