The objective of the present study was to verify if polyurethane foam is a suitable material to make accurate casts of vessels and viscera, and to develop a method based on its use for anatomical studies. This new technique has been tested primarily on the lungs of different animals, but also on the renal, intestinal and equine digital vessels. It consisted of three steps: specimen preparation, injection of the foam and corrosion of the cast. All structures injected with foam were properly filled. The bronchial tree and the vessels could be observed up to their finer branches. The method is inexpensive, simple and requires no special equipment. The pre-casting procedure does not require perfusion of the specimens with formalin, or prolonged flushing with carbon dioxide gas or air for drying. The polyurethane foam does not need a catalyst. It is simply diluted with acetone, which does not cause shrinkage of the cast due to evaporation during hardening. The foam naturally expands into the cavities without high pressure of the inoculum, and hardens in just 2 or 3 h at room temperature. Only two drawbacks were observed. The first is the fact that multiple injections cannot be made in the same cavity since the foam solidifies quickly; the second is the slight brittleness of the cast, due to the low elasticity of polyurethane foam. In conclusion, polyurethane foam was a suitable material for producing accurate casts of vessels and viscera.

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The arterial supply of the cat jejunum was studied by gross dissection and polyurethane corrosion cast. The results showed that the jejunal arteries, which originate from the cranial mesenteric artery, varied from 5 to 15 in number. Their number was independent of the length of the cranial mesenteric artery as well as of the length of the jejunum. These arteries divided into branches giving rise to a series of orders of division from a minimum of 1 to a maximum of 7. The last orders of division terminated in a series of anastomosing arcades which resulted in a marginal artery coursing only a few millimeters from the mesenteric margin of the jejunum. This artery gave rise to straight arteries (vasa recta), whose mean number was 450 ± 60. According to their length, the vasa recta can be differentiated into short (vasa brevia) and long (vasa longa) branches. The vasa brevia ended branching into the mesenteric side of the jejunum whereas the vasa longa coursed beneath the serosa on the lateral jejunal surfaces, and reached the antimesenteric border. During their course, the vasa recta ramified and anastomosed with each other. Numerous antimesenteric anastomoses between opposing vasa longa were also observed. Based on the literature consulted, due to the large number of vasa recta (approximately one vessel per 2.9 mm of jejunal length) and the rich anastomotic network, the cat jejunum might have a better intramural distribution of blood flow and would seem less predisposed to ischemic phenomena than that of other mammals.

This 10-year follow-up study evaluates 25 patients with a total of 57 successfully replanted fingers and six successfully replanted upper limbs. The global functional loss, including loss of range of motion, sensibility, and strength of the hand, was determined using the "Millesi score." The hemodynamic parameters of replanted and control fingers under resting and stress conditions were measured using a laser Doppler flowmeter. The lymphatic system at the site of replantation was examined by fluorescence microlymphography. All patients showed a considerable functional loss, according to the Millesi score, that averaged 56 percent of the normal function of the hand. In order to overcome functional deficit, many patients had developed successful compensatory mechanisms. In general, the patients themselves subjectively rated their functional deficits lower than indicated by the Millesi score. Laser Doppler flowmetry at rest and after arterial occlusion, and capillaroscopy before, during, and after a cold provocation test, revealed subnormal resting flow conditions and significantly decreased vascular capacity in the replanted fingers. Lymphatic drainage capacity was also significantly reduced despite documented reanastomosis between the skin microlymphatic network distal and proximal to the scar (fluorescence microlymphography). The coexistence of functional loss with compensatory mechanisms, decreased reactive hyperemia, and deficit in lymphatic drainage, present in all patients, must be considered as definitive sequelae of the initial injury.

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