ABSTRACT
The gracilis muscle model was used either as a denervated muscle in situ or as a transplanted flap in 273 rats to compare the trophic effects of muscle reinnervation and neurotization using sensory and motor nerves. The average gracilis muscle flap weighed 626 +/- 94 mg at the time of the initial procedure. Experimental muscles were examined 6 months following the procedure. In denervated, nontransplanted muscles, both motor nerve reinnervation and neurotization resulted in significantly preserved muscle mass, averaging 570 +/- 69 and 521 +/- 116 mg, respectively, compared with the denervated control average of 178 +/- 22 mg (p < 0.05). Sensory nerve reinnervation and neurotization produced much smaller trophic effects (p > 0.05). In transplanted gracilis free flaps, however, only direct reinnervation with motor or sensory nerves resulted in improved bulk preservation, with average weights of 313 +/- 83 and 327 +/- 91 mg compared with the control average of 201 +/- 76 mg (p < 0.05). Neither sensory nor motor neurotization was significantly effective in the free-flap model (p > 0.05). These data suggest that transplantation may alter the response of muscle to reinnervation.
Subject(s)
Surgical Flaps , Animals , Femoral Nerve/surgery , Muscle Denervation , Muscle, Skeletal/innervation , Muscle, Skeletal/pathology , Muscle, Skeletal/surgery , Nerve Transfer , Obturator Nerve/surgery , Rats , Rats, Sprague-Dawley , Surgical Flaps/innervation , Surgical Flaps/methods , Surgical Flaps/pathologyABSTRACT
An experimental model for producing venous thrombosis was developed in end-to-end anastomoses of femoral veins in rats. The anastomoses were performed using a suture (9-0 suture-70 microns needle) with a knot 1 cm from the needle. The knot was formed by making either six or eight half-hitches in one throw of the suture. Vessel patency was assessed through the direct "milking test" at 20 min and 24 hrs. The incidence of thrombosis when using one knot with six half-hitches ranged from 20% to 40% and with eight half-hitches, from 50% to 70%. The incidence of femoral vein thrombosis varied directly with the presence and size of the knot. In this model, thrombosis was induced by exaggerating vessel injuries that may occur when performing routine microvascular anastomoses. This study demonstrates a reproducible thrombogenic model which mimics clinical practice and may be used to study the effects of local and systemic antithrombogenic agents.
Subject(s)
Anastomosis, Surgical/adverse effects , Femoral Vein , Suture Techniques/adverse effects , Thrombosis/etiology , Animals , Blood Platelets/ultrastructure , Disease Models, Animal , Femoral Vein/pathology , Femoral Vein/surgery , Fibrin/ultrastructure , Incidence , Male , Microscopy, Electron, Scanning , Microsurgery/adverse effects , Rats , Rats, Sprague-Dawley , Surface Properties , Sutures , Thrombosis/pathology , Time Factors , Tunica Intima/ultrastructure , Vascular PatencyABSTRACT
The rat gastrocnemius muscle can serve as a vascularized, innervated muscle transplant model. To establish the anatomic and technical details of this model, we performed ten gastrocnemius transplants and collected data on muscle weight, dimension, and vessel caliber from each muscle. The muscle, consisting of medial and lateral heads, is supplied by pairs of sural vessels averaging 0.2 mm in diameter. These vessels, however, can be taken in continuity with the femoral vessels (averaging 1.0-1.6 mm in diameter), which are used for transplantation. The muscles weighed an average of 2.8 g, and the average pedicle length was 24 mm. Eight of ten transplanted muscles were viable with intact circulation at 72 hr. The gastrocnemius transplant was technically reliable, and the muscle bulk and contour could allow biochemical and functional studies. Donor site morbidity limits this model to transplantation studies.
