Re‐animation of muscle flaps for improved function in dynamic myoplasty

Abstract

The authors report on a series of experiments designed to produce a skeletal muscle contraction functional for dynamic myoplasties. Conventional stimulation techniques recruit all or most of the muscle fibers simultaneously and with maximal strength. This approach has limitations in free dynamic muscle flap transfers that require the muscle to contract immediately after transfer and before re-innervation. Sequential stimulation of segments of the transferred muscle provides a means of producing non-fatiguing contractions of the muscle in the presence or absence of innervation. The muscles studied were the canine gracilis, and all experiments were acute studies in anesthetized animals. Comparison of conventional and sequential segmental neuromuscular stimulation revealed an increase in muscle fatigue resistance and muscle blood flow with the new approach. This approach offers the opportunity for development of physiologically animated tissue and broadening the abilities of reconstructive surgeons in the repair of functional defects.

Closed-Loop Asynchronous Neuromuscular Electrical Stimulation Prolongs Functional Movements in the Lower Body

“…Both asynchronous stimulation [21]- [34] and sequential stimulation [35]- [38] have been shown to reduce NMES-induced fatigue; however, previous studies have primarily Fig. 1.…”

Comparing the force ripple during asynchronous and conventional stimulation

“…Researchers have examined 2 methods to reduce fatigue during NMES based on the principle of using multiple stimulation channels to reduce the average stimulation frequency in each channel. The first method is sequential stimulation (also described in previous literature as alternating, cyclical, or sequential segmental stimulation). During sequential stimulation, multiple stimulation channels are used to target multiple synergistic muscles or multiple segments of a single muscle .…”

“…The first method is sequential stimulation (also described in previous literature as alternating, cyclical, or sequential segmental stimulation). During sequential stimulation, multiple stimulation channels are used to target multiple synergistic muscles or multiple segments of a single muscle . Pulse trains are then delivered sequentially to each stimulation channel in an effort to reduce the duty cycle of the targeted muscles or muscle segments.…”

DNA degradation in nuclei of muscle cells followed by ischemic injury in a rabbit amputation model

“…Revascularization of ischemic muscle is very common in reconstructive surgery in many different circumstances, including replantation, revascularization after trauma, thrombectomies, aortic reconstruction, treatment of compartment syndromes, and microsurgical transfer of muscle for function reconstructions. [1][2][3][4][5][6][7][8][9] In addition to the mechanism of ischemia, ischemia time is believed to be one of the major factors influencing survival and functional results. 1 When revascularization is attempted after a long ischemia time, irreversible degeneration of tissue cells may cause muscle necrosis and failure of salvage and functional reconstruction.…”