Preserved viability of the isolated bowel segment, created by omentoenteropexy: a histological observation.

Creation of the isolated bowel segment (IBS) by omentoenteropexy in rats and dogs consists of a two-step procedure: initial omentoenteropexy to the antimesenteric border of a jejunal segment, and division of its mesentery 6 weeks later. Viability of this IBS is maintained by the angiogenic process, which occurs at the level of the myoenteropexy. Histological studies were performed by light microscopy on the bowel wall structures of the IBS before and after the mesenteric division, as well as after a lengthening procedure performed on the IBS in one dog. The authors conclude that (1) in rats and dogs the intestinal wall structures of all IBS variants created by omentoenteropexy appear close to normal, and (2) neovascularization can be clearly detected at the level of the omentoenteropexy.

The effect of alfentanil on experimental myocardial infarction size: a comparison with fentanyl and halothane.

We compared the action of alfentanil on experimental myocardial infarction size with two widely used anesthetic drugs: fentanyl and halothane. Myocardial infarction size, measured by histological techniques, was identical for the three drugs investigated. Our results demonstrate that the action of alfentanil on factors governing myocardial oxygen supply and demand in the rat with coronary artery ligation is no different from the action of fentanyl or halothane.

Angiographic appearance of the renal vein in a case of fibromuscular dysplasia of the artery.

Renal venography was performed in a patient suffereing from hypertension due to fibromuscular dysplasia of the renal artery. The venogram revealed morphological changes in the renal veins similar to those seen in fibromuscular dysplasia of the arteries. Histological examination of the veins showed fibrosis of the medial wall layer.

Hypokalemic flaccid paralysis as the presenting symptom of autoimmune interstitial nephropathy.

We describe a patient who presented dramatically with life-threatening hypokalemic flaccid paralysis. Following resuscitation, extensive investigation showed that the patient had lupus erythematosus (SLE) and Sjogren's syndrome (SS) of which she was unaware. A search for the cause of the profound hypokalemia led to the finding of obligatory renal potassium wasting due to distal renal tubular acidosis (RTA), secretory type. The acid base status of the patient showed hyperchloremic metabolic acidosis compatible with distal renal tubular acidosis. Our case is a further proof that patients with "overlap syndrome" (SLE-SS) may have RTA, which may lead to life-threatening hypokalemia. Others have shown that the SLE-SS complex may occasionally be complicated by hyperkalemia. Thus, an autoimmune disease that is relatively common may present with devastating electrolyte abnormalities.

Viability of adipose tissue injected and treated by different methods: an experimental study in the rat.

Fat injection is being used for the correction of various soft-tissue defects. In this study, the manner of fat injection yielding the greatest transplant viability was examined. Autologous fat was obtained from the inguinal area of rats and subsequently reinjected to the nuchal region, an area naturally poor in subcutaneous fat. Before injection, the fat was processed by one or more of the following methods: suture of the recipient area, repeated washing to remove residual blood, and addition of insulin. Transplant status was evaluated by both macroscopic and microscopic examination of the recipient sites 2 weeks and 12 weeks after the injection. The results demonstrated that the injected fat remained in part as viable new fatty tissue in the nuchal area. No statistically significant improvement in the viability of the injection fat was noticed at 2 weeks and 12 weeks after its processing by the different methods just described. Significant positive correlation was demonstrated between the volume of the injected fat and the size of the bulging at the injection area only 2 weeks after the injection.

Self-expandable and highly flexible nitinol stent: immediate and long-term results in dogs.

We sought to investigate the acute and long-term patency rates and the histologic response of coronary arteries to a self-expandable nitinol coil stent. Twenty-two stents were implanted. Angiographic patency was demonstrated acutely in all but one dog, in which the stent was released in a small branch (1 mm); mismatch in stent-to-artery diameters resulted in vessel closure. Two dogs died from anesthesia overdose and two from bleeding within 24 hours. All dogs were treated with aspirin (80 mg/day) and warfarin (2.5 mg/day) for up to 1 month. Sixteen dogs were monitored for 1 to 2 weeks, 1 month, 3 months, 6 months, and 1 year and underwent subsequent angiography and histopathologic examination. Angiographic artery dimensions measured immediately after stent implantation (2.72 +/- 0.4 mm) did not differ from those noted at follow-up (2.68 +/- 0.44 mm, p not significant). Histologic examination showed outward stent pressure compressing the internal elastic membrane and media in most cases. Intimal hyperplasia started at 2 weeks and was most apparent at 3 and 6 months. Mean intimal thickness was 30.7 +/- 10.9 mu, 141.8 +/- 105.4 mu, 227.1 +/- 104.1 mu, 211.8 +/- 99.1 mu, and 170.1 +/- 42.7 mu at 1 to 2 weeks and 1, 3, 6 and 12 months, respectively. Therefore the nitinol self-expandable stent provokes a moderate cellular proliferative response that reaches its maximum in 3 to 6 months without further progression.