Free Muscle Grafts Research Articles

Autogenous free muscle grafts and regeneration in rabbits: a preliminary laboratory study.

From a preliminary study using the flexor digitorum superficialis muscle as an orthotopic free graft in the rabbit forelimb it appears that: (1) viable muscle fibers can be consistently identified in the recipient area, varying from 20 to 100 percent of the normal total fiber count of the FDS graft: (2) viable muscle fibers following grafting appear to be the result of the process of regeneration rather than of survival of original graft fibers; and (3) young rabbits appear to have greater regenerative potential compared with mature rabbits.

Histochemical patterns of dehydrogenase activity in the development of free muscle grafts in the rat.

Patterns of activity of six dehydrogenase enzymes were studied histochemically in 42 free muscle grafts in the rat. Within hours, the surviving peripheral muscle fibers can be distinguished from the central ischemic muscle fibers. The surviving muscle fibers retain their characteristic pattern of staining throughout the post-transplantation period. The central ischemic muscle fibers stain abnormally and by five or six days they lose their enzymatic activity. The zone of regeneration, between the surviving and the ischemic muscle fibers, initially shows little dehydrogenase activity, but as the regenerating muscle fibers mature, they develop first a homogeneous staining pattern and, later, differences in staining intensity among different types of muscle fibers.

Free muscle grafting in facial paralysis

For the dynamic restoration of elevation of the angle of the mouth in facial paralysis six possible variations of free muscle and nerve graft techniques are described. One of the techniques using the previously denervated extensor digitorum brevis muscle with it motor nerve in continuity serving as a cross-face nerve graft, was used in eight patients. The results were disappointing and it is concluded that the method should be abandoned.

Revascularization of the freely grafted extensor digitorum longus muscle in the rat.

The process of revascularization of free grafts of the extensor digitorum longus muscle in rats has been studied by gross, histological and electron microscopic methods. During the first day after transplantation the muscle is entirely avascular, and it consists of a thin peripheral zone of surviving muscle fibers and a large central area of ischemic muscle. The original blood vessels of the graft undergo a sequence of intrinsic and cell-mediated destruction. Scattered sinusoidal vessels begin to grow into the graft starting on the second day, and ingrowing blood vessels progressively invade the deeper tissues of the graft. Most new vessels form in the connective tissues, but some vessels, especially larger ones, grow into persisting basal laminae from preexisting fibers and nerves. The differentiation of new arterioles and venules in free muscle grafts is described. By the end of the first week, the entire graft is revascularized, and ultimately a fairly normal relationship between new capillaries and regenerating muscle fibers is established. In mature grafts, however, irregularities are sometimes found in the organization of smooth muscle cells associated with larger vessels.

Re-animation of the Paralyzed Face

This 367-page work is divided into four parts: (1) Mechanism of Facial Expression and Pathophysiology of Degeneration; (2) Etiology of Disruption of the Facial Neuromuscular Motor Unit; (3) Contemporary Concepts in Free Nerve and Muscle Grafting; (4) Re-animation of the Paralyzed Face. The contributors include otolaryngologists, plastic surgeons, a neurologist, a neurosurgeon, a neuropathologist, and a physical medicine specialist. The organization is such that the reader is taken through anatomy and pathophysiology of the various types of facial paralysis, and then an excellent section on the basic science of nerve and muscle grafting leads into the practical section that deals with reanimation procedures. This third section, itself, is well worth the purchase price of the book. The reanimation procedures are subdivided into the following categories: immediate treatment (this includes a neurologist's chapter on medical treatment for Bell's palsy and an otolaryngologist's concepts with regard to surgical treatment for this disease);

Reinnervation of rat extensor digitorum longus muscles after free grafting.

Free grafts of the extensor digitorum longus (EDL) muscle of the rat are invaded by regenerating nerve fibers during the second postoperative week. Neuromuscular junctions are established during the third week. Levels of choline acetyltransferase (CAT) activity parallel the invasion of the graft by nerve fibers, but this activity never returns to control levels. We conclude that incomplete reinnervation of free muscle grafts may be a factor in the failure of such grafts to reattain the mass of control muscles.

Free Muscle Grafting

Experimental studies in cats indicate that whole muscle bellies transplanted two to three weeks after denervation will survive and become re-innervated. Based on this experimental data, results of free muscle grafting in patients with facial palsy were satisfactory. The author presents his technique together with its clinical and electromyographic evaluation.

Cellular responses to free grafting of the extensor digitorum longus muscle of the rat

The cellular and subcellular responses related to the survival or destruction and subsequent regeneration of muscle fibers within the freely grafted extensor digitorum longus muscle of the rat were examined by light and electron microscopy. A small number of fibers at the periphery of the grafts survived the initial ischemia but underwent denervation changes and accumulated lipid deposits. The majority of fibers in the grafts, however, became ischemic and underwent an intrinsic degeneration within 4 hours. Cell-mediated destruction of the degenerating fibers occurred as the grafts became revascularized. The basal laminae and some of the satellite cells were the only elements of the original fibers that persisted. Regeneration began at the periphery of the graft within three days after grafting and reached the center about three days later. After phagocytosis of the original fibers, presumptive myoblasts within the grafts differentiated into myoblasts and myotubes. The formation of myotubes followed a biphasic pattern of development comparable to that of normal fetal muscle. Although most of the myotubes were formed within the basal lamina remaining from the original fiber, there was also evidence for regeneration outside the basal lamina. Myotubes matured into muscle fibers which were essentially normal in appearance when examined up to 180 days after grafting. Some fibers, however, were atrophic, presumably due to a failure to become innervated, and some fibers were joined by myo-myous junctions. Pre-denervated grafts and Marcaine-treated grafts were also examined. There were more surviving fibers in pre-denervated grafts, and cell-mediated destruction of degenerating fibers proceeded more rapidly than in normal grafts. No surviving fibers were found in Marcaine-treated grafts. The changes in these grafts were otherwise similar to normal grafts. A schematic model of the spatial and temporal sequence of degeneration and regeneration within a free muscle graft is presented.

Free muscle graft pharyngoplasty with palatal retroposition in the treatment of velopharyngeal incompetence

The use of free skeletal muscle autografts in combination with a V-Y push back to the soft palate, in the treatment of velopharyngeal incompetence in 6 patients is reported. This pharyngoplasty offers a reconstruction of the anatomical elements of the region, and enhancement of the physiological functions of the velopharyngeal sphincter in speech production. Of the 6 patients treated, 4 were restored to essentially normal speech, and 2 “salvage” cases were improved; in all cases however, the anatomical mechanism for speech production was effectively augmented.

Transposition of the soleus into the bed of the extensor digitorum longus muscle in the rat

In 38 rats the slow soleus muscle was transposed, with its neurovascular bundle intact, into the bed of the fast extensor digitorum longus muscle. Transposed muscles underwent degeneration and regeneration like free muscle grafts. Both contractile and histochemical properties remained those of the soleus muscle, supporting the conclusion that the nerve to a slow muscle is pre-eminent in determining the functional and histochemical characteristics of the muscle.

A new nasal tunnel in the correction of paralytic lagophthalmos with free muscle grafts

A modified method is described for the construction of a tunnel through the nasal bones in order to accomodate the tendon in Thompson's muscle grafting technique for the treatment of paralytic lagophthalmos.

Indication of the Reattachment Operation

Micro-surgical operation in orthopedic surgery (the reattachment of limbs and fingers, the free skin flap, the free muscle graft, the living bone graft, the living nerve graft, etc) is gradually popular.Now a day, a indication of the reattachment operation is a big problem, because of the difficulty and the emergency of the operation and the difference between desire of patient and medical indication.We discussed about factors which will influence the indication of the reattachment operation.

Can one muscle reinnervate another? A preliminary study of muscular neurotization in the rabbit.

A laboratory model for study of possible reinnervation at the muscle level is presented. The preliminary histochemical results suggest that muscular neurotization occurs following removal of the investing fascia. However, the muscle atrophy (which follows denervation) continues to take place in spite of such reinnervation. The potential clinical relevance of these findings to free muscle grafting is discussed.

Effect of previous nerve injury on the regeneration of free autogenous muscle grafts

Free autogenous skeletal muscle transplantation is now an established experimental and clinical procedure. However, when large muscles are used, surviving grafts are found to contain substantial amounts of noncontractile tissue. This may result from delayed reinnervation and may itself impede innervation. Previous workers have suggested that prior denervation of a muscle improves the rate of regeneration after grafting. It has also been reported that accelerated axonal regeneration follows nerve transection when the nerve has been “primed” by a prior crush. Experiments have been carried out to show whether or not the latter procedure, either alone or in combination with prior graft denervation, would further improve the functional performance of a graft by hastening reinnervation. The tibialis anterior muscles of rats were transposed 2 weeks after one or both common peroneal nerves had been crushed. Three months after transposition the muscles were weighed and the maximum isometric tension developed was recorded. The transplanted muscles which had been both denervated prior to transposition and reinnervated by a nerve primed by a previous crush developed substantially greater tensions per g of muscle than did those that had been subjected to either of these procedures alone. We concluded that a more rapid reinnervation of regenerating fibers leads to a greater proportion of functioning contractile tissue in muscle grafts.

A rapid silver impregnation for central and peripheral nerve fibers in paraffin and frozen sections

The direction of known staged process of regeneration of free muscle grafts was inverted in our experimental rat model from a centripetal to a centrifugal by central implantation of blood vessels into isolated free muscle grafts.The effects of innervation, reinnervation and exercise on muscle fiber regeneration were analyzed at various intervals from 4 to 90 days by morphological and morphometric methods. Reinnervation occurred as well in grafts with the motor nerve left intact as it did in grafts with a severed and reimplanted nerve. Reinnervation proved to be prerequisite for a lasting muscle regeneration. Denervated muscle grafts even after neovascularization underwent irreversible fibrosis. A positive effect of exercise on the early states (30 days) of muscle regeneration was revealed by morphometrical analysis. In the long term (90 days) fiber diameter assimilated in all groups. The animal model mimics a clinical situation of flap prefabrication demonstrating the relationship of functional tissue regeneration and neovascularization. It can be transferred into the acute clinical situation as well as in tissue engineering.

Experimental Studies and Clinical Cases in Free Skin Flap, Muscle Graft and Omentum Graft

The angiography of the iliofemoral area was disscussed and classified in 4 types concidering the anatomy of the superficial circumflex iliac artery and superficial inferior epigastric artery.8 cases of the free hypogastric skin flap operation were tried. One of 8 cases was operated for requiring the good gliding floor of the flexor tendon.The free muscle graft operation was succeeded in 59 years old man in March, 1976.The usefulness of the omentum graft in orthopaedic was emphasized.

Innervation of free muscle grafts in the rat in the absence of mechanical trauma to surrounding muscles or nerves

Soleus muscles in the rat were freely grafted alongside a normal soleus muscle in the absence of mechanical trauma to any of the surrounding muscles or motor nerves. The object of this experiment was to determine whether or not the muscle grafts would become reinnervated under these circumstances. Contractile and histochemical properties of the grafts were compared with those of the contralateral denervated soleus as well as normal muscles. Innervation of the grafts did occur, and it was concluded that the innervation of the grafts arose primarily from sprouts from nerves supplying neighboring muscles. The grafts were studied with specific nerve stains, histochemical techniques and by analysis of their contractile properties.

A quantitative study of muscle fiber survival and regeneration in normal, predenervated, and Marcaine-treated free muscle grafts in the rat

Free grafts were performed on the rat extensor digitorum longus muscle after no pretreatment, 14-day predenervation, or two or one preinjections of Marcaine. Numbers of surviving muscle fibers were counted in 4-day grafts, and the total number of muscle fibers was counted in 60-day grafts. Mean numbers of surviving muscle fibers in 4-day grafts were 132 for untreated muscles, 1166 for predenervated muscles, and eight and two for muscles treated with two and one Marcaine injections, respectively. In all four groups, the numbers of muscle fibers in 60-day grafts did not differ significantly from the mean number of muscle fibers (3880) in the normal extensor digitorum longus. It was concluded that most of the muscle fibers found in a mature free graft are newly regenerated rather than surviving original muscle fibers.

THE FAILURE TO SURVIVE OF AUTOGENOUS FREE GRAFTS OF WHOLE GRACILIS MUSCLES IN DOGS

An experimental study was undertaken to define the limits in size (if any) of successful free autogenous grafts of skeletal muscle. In 8 dogs, 16 gracilis muscle grafts were transplanted to the contralateral hind limb. The left hind limb served as a control for the right side, which contained paralyzed muscle. Macroscopic, microscopic, and EMG analyses demonstrated a complete failure of the free muscle grafts to take and survive. We have shown that one can exceed the limitations to the size of a successful muscle graft. Perhaps future investigators will define exactly what the maximum viable size is.

Failure of free muscle grafts in dogs

THE first report of successful muscle grafting seems to have been that of Studitsky and Bosova (I96O) who transplanted part of the previously denervated gastrocnemius of the rat with histological proof of survival. In I971 Thompson published his preliminary experimental and clinical results and a number of other papers have followed (Thompson, I97Ia, b, c; Carlson and Gutmann, 1974; Freilinger et al., 1974; Hakelius et al., 1975). Thompson maintained that success could be achieved by preliminary denervation of the graft and by transferring the entire muscle to lie in intimate contact with a normally innervated muscle. Although his patients appeared to have been clinically improved, the evidence of functioning graft survival did not seem convincing in many cases. Moreover, analysis of his experimental results showed that, of 8 previously denervated grafts, fibrous tissue composed three-quarters or more of the surviving bulk in 4, and half the bulk in I. Only 3 muscles had more than 50 per cent of the surviving bulk composed of muscle fibres. We therefore felt that further experimental work was desirable, and designed a model in the dog which would fulfil the criteria Thompson had laid down and which would show not only whether there was survival of muscle but whether the muscle would function.