Read in an abbreviated form at the 3rd Congrès de la Société Européenne de Chirurgie cardio-vasculaire, Zürich, July 1956. In 1950 Wanke, Kiel, described a new operative method for the surgical treatment of sequelae after old cases of thrombosis of the pelvic veins. He found that the narrowing of the v. iliaca ext. and communis is frequently caused not so much by the lacking recanalization of the vein but rather by compression from withmd as a result of a cicatricial sclerotic transformation of the common sheath caused by former perivenous inflammation. Wanke mentions a closure of the pelvic vessels and therefore recommends shelling out of the callus-like transformations of the sheath. In this we were successful on the occasion of the first operation of this kind performed by us in 1955 ( fig. 1). Further surgical operations, however, led us to suspect that in by far the greater number of cases the obstacle was of an intervasal nature. This induced us to carry out a close investigation of the problem, and this was done at the Department of Pathology of Innsbruck University by J. Thurner. The peculiar fact that thromboses of the pelvic veins occur five times as frequently on the left side as on the right, and that on the left side the v. iliaca communis is affected in a particularly large number of cases has already been known for a considerable length of time and has, since the time of Virchow, always been explained as an obstruction of the flow of the left v. iliaca communis caused by the artery resting upon it. Our investigations of the structure of pelvic veins on 430 cadavers led to the discovery of a peculiar formation in the form of a spur-like projection in the v. iliaca comm. sin. at the mouth of the v. cava. This result was obtained in from 15 to 22 per cent of the cases investigated. By this we believe we have found the key to the problem.Although this spur-like projection, which will henceforth be referred to as &dquo;spur,&dquo; has already been described by Mc Murrich (1906 and1908) it never received the attention it deserved, nor was this the case with later references to the same subject which were made by J. V. Basmajian. A thorough examination of this &dquo;spur&dquo; was carried out only by Krumbhaar andEhrich in 1943, and Di Dio 1949, but, apart from the fact that these examinations were almost entirely macroscopic, the conclusions are different from those arrived at by us. Figure 2 shows the position of the &dquo;spur&dquo; in dorso-anterior view. We found the &dquo;spur&dquo; developed in the form of three different types. a. Lateral &dquo;spur&dquo; ( fig. 3). A coulisse-like tender membrane protrudes velumlike from the medial or lateral wall towards the lumen, which it narrows. The illustration shows the &dquo;spur&dquo; in dorso-anterior view so that it only appears to
Perineurial cells are specialized connective tissue cells that form a barrier between endoneurium and epineurium in normal nerves. In the present study, the formation of the perineurium after transection of rat sciatic nerves was investigated. The cord bridging the gap between proximal and distal stumps through silicone tubes was studied 3, 7, 12, 18, and 21 days after surgery using electron microscopy and antibodies against epithelial membrane antigen (EMA), a marker for perineurial cells that has thus far not been applied to the study of differentiating cells in nerve tubulation systems. Initially, a thin cord consisting of fibrin bridged the gap between the stumps. At 7 days, longitudinal cells had migrated from both stumps toward the center of the tubes on the surface of the fibrin cord. These cells were immunoreactive with anti-EMA. At 12 days, ultrastructural features of perineurial cells (desmosomes, tight junctions, actin filaments with dense bodies, tonofilaments) were prominent in these cells. Subsequently, the gap was bridged through the perineurial tube by endothelial cells, pericytes, fibroblasts, Schwann cells, and axons. At 21 days, a single large nerve fascicle ensheathed by a mature perineurium was found between the stumps. Thus, the first cells to connect proximal and distal stumps in the investigated nerve regeneration silicon chamber system are perineurial cells. Through the tube formed by these cells, blood vessels and nerve fibers bridge the gap. Therefore, establishment of a perineurial connection between nerve stumps appears to be important in the sequence of events during nerve regeneration.
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