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Vibration syndrome, a clinical condition arising from chronic use of vibrating tools, is associated with a spectrum of neurovascular symptoms. To date, only its vascular pathology has been extensively studied; we sought to determine what direct neurologic injury, if any, is caused by vibration. Hindlimbs of anesthetized rats were affixed to a vibrating platform 4 h a day for 7 days. Study animals were vibrated with set parameters for frequency, acceleration, velocity, and amplitude; control animals were not vibrated. On day 7, nerves were studied by light and electron microscopy. While light microscopy showed minimal histologic differences between vibrated (n=12) and control (n=12) nerves, electron microscopic changes were dramatic. Splitting of the myelin sheath and axonal damage (e.g., myelin balls and "finger ring") were consistently seen in both myelinated and nonmyelinated axons. Despite relatively short vibration, definite pathology was demonstrated, suggesting that vibration syndrome has a direct neurologic component.

The tour de force of this paper lies in the review of clinical presentation of occluded Greenfield filters in a group of patients contraindicated for postopera tive anticoagulation. Nine of 59 patients (15.3%) had occluded filters. Eight of these 9 patients (88.8%) had primary brain tumors. This study, for the first time, to the authors' knowledge, reports a high incidence of caval thrombosis in brain tumor patients (8/31:25.8%) and of an association between caval throm bosis and recurrent deep vein thrombosis. Deep vein thrombosis (DVT) was seen in 88.8% of patients with caval thrombosis in this service. It is the authors' contention that recurrent DVT, at least in brain tumor patients, should alert the physician to evaluate caval patency. Caval thrombosis was noticed even sixty weeks after the placement of Greenfield filter. The authors conclude, therefore, that brain tumor patients had a high incidence of occluded filters; lower extrem ity morbidity provided a clue to such an event, and such a scenario should raise concerns regarding caval patency, even in long-term follow-up.

The microcirculatory evolution of healing wounds has not been well documented. The authors tested the generally accepted hypothesis that an end-to-end, stapled anastomosis (EEA) causes less microcirculatory compromises to the wound edge than an end-on, single-layer, hand-sewn anastomosis (HSA) does. The quanti tative measurement of the microcir culation associated with hand-sewn and stapled colonic anastomoses was carried out in two groups of dogs, each containing 28 animals. The mi crocirculatory evolution with use of either technique was similar, and the data in this study failed to support the common belief that the "B" shape of the staples results in mini mal trauma to the microcirculation and thus allows capillary growth through the tissue enclosed by the staple. In contrast to other studies, however, the authors noticed cross- circulation as early as the third post operative day in either technique. Moreover, by this angiographic method, they noted a gradual in crease in the extent of cross-circula tion from days 3 to 13 in both types of anastomoses. To their knowledge this study represents the first report of a comparison of trauma caused to the microcirculation by mechanical su tures and single-layer, hand-sewn technique.

This study reports the preliminary results of a new totally stapled end-to-end colonic anastomosis in 11 dogs. This “triple-stapled” end-to-end anastomosis was performed with one circular staple line and two linear staple lines, eliminating the need for a colotomy or purse-string suture. The fact that the anvil and anvil stem of a new circular stapling device (Premium EEA™) can be detached from the frame of the instrument allows the anvil stem to be brought out through the proximal linear stapled colon. The trocar mounted on the main stem of the circular stapler allows the stem of the main device to be brought out through the distal staple line. Thus, a totally stapled colonic anastomosis is created after mating the anvil stem and main stem of the instrument. The new anastomosis was evaluated radiographically and at necropsy. The use of this technique resulted in no clinically detectable leaks, suggesting that it may facilitate the performance of anterior resections in humans.