Rollin K. Daniel

Free vascularized bone grafts in surgery of the upper extremity.

Free vascularized fibular grafts were employed in five patients with segmental bone defects following trauma or resection of tumors of the upper extremity with excellent results in three patients and satisfactory results in two. No donor site morbidity was experienced. A comparison with rib and iliac crest grafts indicates that the fibula is more suitable for reconstruction of long bone defects. The advantages of this technique are stability without sacrificing viability and a shorter immobilization period with more rapid incorporation and hypertrophy of the graft. The disadvantages are prolonged operating time, difficulty in assessing patency of anastamoses in the immediate postoperative period, and sacrifice of a major vessel in the lower extremity.

Tissue transplants in primates for upper extremity reconstruction: A preliminary report

Recent advances in clinical transplantation surgery suggest that hand transplantation is no longer an unrealistic expectation. However, two questions must be answered. Can composite tissue transplants survive in a primate species? Does the required neural reinnervation occur under immunosuppression? Four hand transplants and seven neurovascular free flap transplants were done in baboons immunosuppressed with Cyclosporin A and steroids (methylprednisolone). Long-term survival occurred in nine. Electrophysiologic tests of sensory axons revealed reinnervation of transplanted skin as evidenced by well-defined, low threshold receptive fields in the donor tissue. Reinnervation of donor muscle was demonstrated by motor unit recruitment in stepwise fashion after electrical stimulation of the recipients median and ulnar nerves. Afferent fibers serving the donors joints and muscle spindles were also observed.

THE NORMAL HEALING PROCESS OF MICROVASCULAR ANASTOMOSES

The vessel wall regeneration and the inflammatory response in the rabbit femoral artery and vein the first three months after microvascular end-to-end suture anastomosis was assessed histologically. The initial damage consisted of endothelial loss and partial necrosis of media and adventitia. The luminal surface was reendothelialized and the adventitial layer restored by 20 days, but the necrotized part of the media did not regenerate. Instead, the vessel wall diameter was maintained by an intimal hyperplastic response. At the anastomotic site a characteristic slight dilatation was persistent. Consequently, the vessel wall architecture was not restored to the preoperative state after microvascular anastomosis.

Muscle Coverage of Pressure Points???The Role of Myocutaneous Flaps

Although myocutaneous flaps have evolved into a primary method for managing pressure sores, their value in reducing the recurrence rate by padding the pressure point is open to question. The use of muscle to cover a pressure point violates the normal soft–tissue coverage of a bony prominence and introduces a tissue that is exquisitely sensitive to ischemia. Clinical follow–up of patients who have had myocutaneous flaps for closure of pressure sores demonstrates almost total muscle atrophy. Although skin coverage is stable, the muscle bulk of a myocutaneous flap is not retained beyond one to two years. The long–term value of myocutaneous flaps in reducing the recurrence rate of pressure sores requires careful follow–up in major series of cases.

Evaluation of Clinical Microvascular Anastomoses- Reasons for Failure

Thrombosis in clinical microvascular anastomoses is attributed to suture errors and utilization of severely damaged recipient arteries. Histopathological specimens from 24 microvascular anastomoses and 77 vessel biopsies from free tissue transfers and replantation cases were analyzed. Suture errors of any note were rare and occurred primarily in replantation cases in which team experience varied and fatigue was common. Recipient artery damage ranged from minimal to severe; clinical analysis confirmed the devastating effect of refractory spasm associated with intramural scarring from previous trauma. Additional studies by microvascular groups are needed to clarify the causes of thrombosis and the healing mechanism of microvascular anastomosis.

High-voltage electrical injury: acute pathophysiology

A reproducible high-voltage electrical injury model was established in the primate using a new approach to energy administration, measurement instrumentation, and data acquisition. Patterns of current repartition and temperature generation were examined in 24 primates. The predominant current load was carried in muscle, which is the tissue group occupying the largest cross-sectional area. Highest temperature values observed were in muscles of small cross-sectional diameter and in tissues of high inherent resistance. Surgeons should be aware of the principles and the pattern of current distribution when performing early debridement and/or definitive coverage procedures.

Management of Severe Forearm Injuries

A review of principles and an operative guideline for repair of severely mutilating injuries to the forearm have been set forth. These concepts and their application have been illustrated in a series of clinical cases. The following key concepts have developed from these clinical experiences: 1. The surgeon must evaluate each case based upon the potential for return of sensation and function. One cannot justify the statement that a replanted arm is always superior to a prosthesis, even if its only purpose is cosmetic. 2. Care must be taken in the emergency room to evaluate the entire patient, and not to ignore other injuries while concentrating on a mangled extremity. 3. The crush-avulsion nature of injuries seen in a large referral center necessitates aggressive debridement of damaged soft tissue and bone. Wounds that have avulsion of skin, muscle, and nerve throughout the length of the arm do not lend themselves to repair. Destruction of an elbow joint generally precludes repair. 4. A well stabilized skeleton is essential before definitive soft tissue repairs can be performed. 5. Vascular repairs are meticulously performed using magnification. All vessels are reconstructed in an effort to recreate the original anatomy. 6. Wide destruction of muscle and tendon is frequent necessitating ingenuity in connecting proximal motor units to distal tendon. After repair, early active motion of the extremity is emphasized. 7. Perhaps the strongest contraindication to reconstruction of a severely damaged upper limb is avulsion of the nerves throughout the length of the forearm. Sharply divided nerves can be repaired by group fascicular suture. Crushed, divided nerves do well with accurate epineural approximation. Crushed nerves with epineural continuity ar best treated by observation and secondary grafting as required. 8. Primary coverage of areas denuded of skin is by split graft of local transposition flaps. More sophisticated techniques may be used at a later time (myocutaneous flaps or free flaps) if further reconstruction is contemplated. 9. Dressing must be carefully applied without constricting the extremity. A protective plaster is applied beginning from above the elbow and ending in a bonnet over the hand; this allows the recovery room nurse to monitor the vascular status of the repair. 10. The physiotherapist and occupational therapist are integrated into the perioperative care. Active range of motion exercises are begun as soon as the third day after the operation. Lightweight static and dynamic splints help to restore mobility.

Neuroanatomical evidence of reinnervation in primate allografted (transplanted) skin during cyclosporine immunosuppression

Histological evidence is presented documenting the reinnervation of sensory mechanoreceptors across major histocompatibility barriers in allografted primate (baboon) skin. Meissner and pacinian corpuscles, as well as hair follicles, showed a spectrum of reinnervation by host axons. Our light and electron microscopic evidence to date has suggested that allografted Merkel cells did not survive transplantation. This, and other instances of tissue and receptor destruction resulting from histoincompatibility, indicated marked differences when skin allografts were compared to autografts with respect to the ability of host axons to locate and reinnervate sensory mechanoreceptors.

Microsurgical Treatment of Vascular Impotence

Abstract Vasculogenic impotence is a theoretically curable disease but its treatment generally has met with little success. We report on a patient with carefully documented vasculogenic impotence who was markedly improved by direct microsurgical revascularization of the penis.

Depressed Scars and Soft Tissues

The authors describe a technique that brings great improvement to the treatment of depressed scars. It is simple and safe as long as enough superficial tissue is available. Unequal peripheral undermining allows closure under minimal tension, is less extensive than in previously described techniques, and separates the deep scar from the superficial one.