Second-intention healing

Second-intention healing (contraction and epithelization) is most appropriate for heavily traumatized, contaminated wounds that may have a prolonged debridement phase. Therapy during healing can promote rapid debridement and faster healing. Healing of lower limb wounds by second intention may be protracted, owing to poorer wound contraction and excessive granulation tissue production as compared with body wounds.     

Bone healing

Bone is a tissue composed of organic (cells and matrix) and inorganic (mineral) components. When the mechanical strength of bone is exceeded, fracture occurs. Healing progresses through inflammatory, reparative, and remodeling phases similar to other tissues, but, unlike other tissues, bone possesses the unique capability to completely regenerate and return to pre-injury strength. The bone healing process is influenced by many factors, including mechanical stress, biochemical mediators, bioelectric and piezoelectric properties, and neural and endocrine influences. In short, any factor capable of altering the metabolism of osteogenic cells can influence bone healing.     

Intestinal healing and methods of anastomosis

Optimal intestinal healing occurs when like layers of the intestinal wall are aligned. Hand-sewn, double-layer, end-to-end anastomosis that apposes the mucosa and produces slight inversion of the seromuscular layer is recommended to minimize adhesion formation and provide reasonable alignment of the intestinal layers. Stapled, everted, triangulated, end-to-end anastomosis is not recommended because of extensive adhesion formation and poor healing of the intestinal layers. The preferred stapled techniques create an inverting, side-to-side stoma between the bowel segments.     

Factors that delay healing

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Basic mammalian bone anatomy and healing.

The goal of any method of fracture repair should be the early return to function of the patient with minimum postoperative morbidity. This is accomplished most optimally by having a basic understanding of the biology of bone healing and by being familiar with the musculoskeletal system of the species before attempting fracture repair. Applying the fundamental principles of mammalian bone anatomy and physiology to the bird ensures the best prognosis possible and minimizes postoperative complications in the avian patient.     

Basic avian bone growth and healing.

There have been few studies on the process of fracture repair in avian species. Most of the information shows similarities between avian and mammalian bone growth and fracture repair, but there are differences. The main finding confirms that fractures must be reduced properly, stabilized, and immobilized with an adequate blood supply to the bone fragments for optimal healing. The return to function of extremities, particularly the legs and wings, is an important consideration when internal fixation methods are used. Causing little or no collateral damage to soft tissue and joint when implanting internal hardware is ideal and reduces the likelihood of impaired function. Whether internal or external fixation methods are used for fracture reduction, the knowledge of avian bone growth and fracture repair is essential for veterinarian understanding and when discussing the healing process with clients.     

Principles of wound healing

Wound healing can be divided into immediate (zero to 1 hour), early (1 to 24 hours), intermediate (1 to 7 days), and late (greater than 7 days) stages. Many physical and physiologic events occur simultaneously and sequentially during these stages to produce the final wound scar. The processes of skin retraction, scab formation, would debridement, wound contraction, epithelial migration and proliferation, fibroplasia, and collagen maturation all must occur for healing to be successful. Many factors affect the size and shape of the resulting scar, including anatomic location and skin tension forces, systemic condition of the patient, blood supply to the wound, nutritional factors, environmental temperature, the presence of systemic drugs, wound infection, motion, wound oxygen gradient, wound moisture, and bandaging. Ideally, each of the factors would occur at a level compatible with optimal healing, but, in many clinical cases, one or more factors compromise normal, rapid healing. When we intervene with therapy, we probably adversely affect another factor in healing, while trying to correct the factor that is out of balance. In these decisions, the effects of our treatment on wound healing should be considered. The trade-off should be weighed and the treatment pursued only as long as necessary to allow healing to progress; then it should be discontinued or changed. With these considerations, it is hoped that we can attain healing at the most rapid physiologic rate.     

Wound healing in skin

Wound healing in mammals occurs by a process of regeneration and scar tissue production. In particular, epithelium has marked regenerative capacity. Healing is an active process from the moment the wound is inflicted--a "lag" phase does not exist. In surgery the important factors affecting wound healing are protein deficiency, uremia, corticosteroids, and local tissue injury. Stimulants to wound healing are not available for clinical application.     

Ferrets: wound healing and therapy.

In all species of mammals, the stages of wound healing are the same, and both host factors and wound characteristics affect how wounds heal. The basic principles of wound care in ferrets, such as lavage, bandaging, and surgical closure, are similar to those in other species; however, knowledge of ferrets' anatomy and pathophysiology, as well as skin conditions commonly seen in ferrets, will help ensure proper wound healing.     

Wound healing and management in psittacine birds.

Psittacines and other companion avian species often develop wounds requiring some form of medical or surgical therapy. Advancing technology in the field of wound care and management continues to evolve for use by the veterinary clinician. Although not all wounds can be successfully treated, many can be reduced and minimized with therapy. Consideration of the overall health, management, and nutrition of the avian patient will also aid in wound management. The avian patient with normal immune function and optimal nutrition will have improved wound healing compared with an immunocompromized or malnourished patient. The duration of treatment and potential stress of the wound-management program should also be taken into consideration when selecting a treatment program for the avian patient.