Comparison of muscle mass preservation in denervated muscle and transplanted muscle flaps after motor and sensory reinnervation and neurotization.

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.

Rat intercostal nerves as experimental nerve grafts.

In this study, we dissected and measured both sets of intercostal nerves including lengths, diameters, and axon counts in 12 adult rats to provide data applicable to experimental nerve graft research. Dissections showed that total lengths of intercostal nerves from the spinal bifurcation to their last arborizations near the midline ranged from 10 to 89 mm, and diameters ranged from less than 0.1 to 0.5 mm from the thinnest to the thickest part. The segment of easiest dissection was the part between the spinal bifurcation and the lateral cutaneous branch. This part was 4-27 mm (mean, 13.3 mm) long and had an almost constant diameter of 0.18-0.5 mm (mean, 0.32 mm). Counts ranged from 201 to 566 axons/ nerve. The segment proximal to the lateral cutaneous branch was the most convenient part to be harvested as a nerve graft, especially in the 8th to 12th intercostal nerves. These nerves could serve as sources for experimental grafts.

Microvenous thrombosis rates following anastomosis with vein grafting and a knotted suture.

An experimental microvenous thrombosis model was developed combining vein grafting in femoral vein defects with exaggerated vessel injuries using a knotted suture in the vessel repair. The rat femoral vein grafts were separately subjected to injuries caused by an anastomosis performed with a suture knotted with eight half-hitches at the distal anastomosis (upstream), the proximal anastomosis (downstream), and both anastomotic sites. These groups were compared to vein grafting done with a standard suture. Vessel patency was assessed at 20 min and 24 hr, and the thrombus component was histologically analyzed at 24 hr after the procedures. One hundred percent of control vein grafts were patent at 24 hr. All experimental groups had significantly decreased patency at 24 hr (P < 0.001). Among the experimental groups, knotted suture anastomoses at both anastomoses produced significantly lower patency (13.3%, P < 0.05) than knotted suture anastomoses at distal anastomoses. Histological analyses of thrombosed grafts showed that a large amount of thrombocyte deposition and inflammatory cells were noted at both anastomotic sites in the vein grafts with a knotted suture at the distal anastomosis and in the grafts with a knotted suture at both anastomoses. Thrombocyte deposition and inflammatory cells were seen only at the site of proximal anastomosis when using a knotted suture at the proximal anastomosis site alone. This study demonstrated that quantified microvenous thrombosis can be produced by exaggerating vessel injuries with a knotted suture in a vein graft model. This thrombosis model can be used to study the effects of antithrombogenic agents.

Comparison of nylon and polypropylene sutures in a microvenous thrombosis model.

Thrombosis rates of femoral end-to-end microvenous anastomoses with nylon and polypropylene sutures (9-0 suture, 70 mu needle) were compared in a microvenous thrombosis model. The vessel injuries were produced during anastomosis by using a suture with a knot 1 cm from the needle. Anastomotic thrombosis rates were assessed by visual inspection and strip test at 24 hr postoperatively. Low thrombosis rates (0% and 20%, respectively) of anastomoses with both unknotted nylon and unknotted polypropylene sutures were obtained. Anastomoses with knotted nylon and polypropylene sutures resulted in 65% and 45% thrombosis rates, respectively. Statistical analyses showed that there were no significant differences between thrombosis rates, both in anastomosis performance with unknotted nylon and polypropylene sutures (P > 0.05) and with knotted nylon and polypropylene sutures (P > 0.05), while there were significant differences between the thrombosis rate using unknotted sutures and knotted sutures (P < 0.01). It was concluded that vascular injury, not suture material, is the main factor leading to thrombosis in this model.

Anteromedial thigh: a source for phallic reconstruction.

The anteromedial thigh region is a fruitful site to create different types of fasciocutaneous flaps and compound flaps because of its versatile fasciocutaneous vascularization. On the other hand, phallic reconstruction is still a challenge. We used a proximally based, fasciosubcutaneous pedicle anteromedial thigh fasciocutaneous flap to reconstruct a penis for an electrical burn patient, including the gracilis muscle into the flap for additional bulk. This flap has the potential for sensory reinnervation, its application is easy with regard to a microvascular operation and it presents a remarkable option in phallic reconstruction.

Primary tuberculosis of the parotid gland.

A very unusual presentation of Mycobacterium tuberculosis in the parotid gland substance is described to suggest reexamination of the place of tuberculosis in the differential diagnosis of a parotid mass. In this patient, diagnosis was made postoperatively only by histologic examination of the excised specimen. When M. tuberculosis etiology is suspected, either clinically or at operation, culture confirmation should be tried, and a Mantoux test should be performed to complete the investigation.

Use of a sartorius myofasciocutaneous flap for reconstruction of a large, full-thickness abdominal wall defect.

Many methods for the repair of abdominal wall defects have been described in the literature. In this report we present an alternative to the widely used thigh flaps for repair of large full-thickness abdominal wall defects not amenable to direct closure or repair with local flaps. We report one case of this type of abdominal wall defect closed in one stage using a proximally based sartorius myofasciocutaneous flap. Although an excellent result was obtained in this case, the general applicability of the sartorius proximally based flap in plastic surgery of the abdominal wall requires further investigation.