Musculocutaneous regional and distal flaps have become an important tool available to the head and neck surgeon. Vascularized autogenous muscle transplants allow single-stage reconstruction of complex defects. Ischemic muscle necrosis is a well-recognized complication with serious potential morbidity. It has been shown that myocardial muscle is protected from ischemic damage by brief periods of coronary artery occlusion and reperfusion subsequent to prolonged ischemia. This is called preconditioning. To our knowledge, this technique has never been extrapolated to skeletal muscle. This article presents a discussion of preconditioning and the potential benefits of this new technique as a means to enhance skeletal muscle survival to sustained normothermic global ischemia. Theories behind ischemic muscle injury are presented. A review of the development of preconditioning in myocardial muscle is discussed. Experimental models used to investigate this phenomenon are also presented. In addition, results of our laboratory investigations using the latissimus dorsi porcine model are discussed. Preconditioning is a new, nonpharmacologic means to improve muscle flap survival. This simple technique may have great clinical application in reducing ischemic muscle necrosis in regional and distal muscle transplantation.

This article provides a concise review on the potential causes of ischemia-induced reperfusion (I/R) injury and pharmacologic intervention in the skeletal muscle. Special emphasis is placed on the recent observation of the acute ischemic preconditioning phenomenon for prevention of I/R injury in skeletal muscle. Finally, the mechanism of ischemic preconditioning and its clinical applications for augmentation of skeletal muscle tolerance to prolonged ischemic insult are discussed.

Hyperbaric oxygen (HBO) has been used as a tool in the management of osteoradionecrosis (ORN). However, it has not been conclusively proven to be of benefit. The precise role and guidelines for its use also have not been clearly defined. This report retrospectively analyzes 41 patients treated at the Hyperbaric Chamber Unit at the Toronto Hospital (Toronto General Division) with proven mandibular ORN from 1980 to 1985. The results show that 83% of the patients had a significant improvement with HBO therapy, judged by at least a 50% decrease in the size of the exposed bone, closing of the fistulous tract, or complete relief of symptoms. Within the group of patients who were significantly improved, 15% showed complete resolution of ORN. Seven (17%) of the patients did not benefit from the HBO. All seven patients had radiological evidence of dead bone. Based on these observations, the following conclusions can be made: 1. HBO is of benefit in the management of ORN. 2. Patients with ORN may be divided into two groups: mild and severe. 3. Cases of mild ORN will heal with HBO alone, but, in severe ORN, surgery is necessary to remove dead bone. 4. All patients with ORN should receive dental evaluation, local wound care, and a strict oral hygiene regimen. Diseased teeth should be removed prior to radiotherapy. Subsequently, any teeth that became abscessed should be extracted in conjunction with prophylactic HBO. Antibiotics play an ancillary role in the management of ORN. For patients who have received radiation to the mandible, the authors propose regular follow-up in order to detect ORN at a time when HBO can arrest the disease.