Venous valvular insufficiency: influence of a single venous valve (native and experimental)

This report evaluates the ability of a single competent (native or experimental) superficial femoral vein valve to correct canine hindlimb venous insufficiency. The time to maximal ankle venous pressure after standing (VFT) and to 90% of that time after exercise (VRT90), and the minimal pressure after exercise (AVP) were measured in 17 greyhounds before intervention, after only the superficial femoral vein valve remained (n = 5), and after complete lower limb venous valvulotomy (n = 17). Three weeks later, 12 dogs underwent a native (n = 4) or experimental (n = 8) autogenous venous valve transplantation. Immediately and at 3 weeks after transplantation, venous pressure measurements were obtained. The manual strip test confirmed valve competence at the time of sacrifice. Only one valve transplant became incompetent. Immediately after single superficial femoral vein valve construction, VFT, AVP, and VRT90 measurements were not significantly different from normal. Three weeks after transplantation the AVP measurements were consistent with an insufficient venous system, whereas the VRT90 measurements were between and statistically different from both the control and totally incompetent system (p less than 0.05). After the native valve but not the experimental valve transplantations VFT normalized. These data suggest that insertion of a single competent superficial femoral vein valve into an incompetent lower limb venous system corrects venous pressure measurements initially but soon provides only a partially competent system. The experimental valve, although competent, is less responsive than a native valve.

Acute mesenteric venous thrombosis. Revisited in a time of diagnostic clarity

Historically, mesenteric venous thrombosis (MVT) has been found during laparotomy or at autopsy. Improvements in computed tomography (CT) and ultrasound (U/S) may identify patients earlier in their clinical course. How has this altered the treatment strategy of the authors? This 10-year retrospective study of acute MVT consisted of 12 men and three women (average age 43). Presenting signs and symptoms were nonspecific in 10/15 patients resulting in multiple diagnostic tests. All CT scans (10) and angiograms (4) revealed mesenteric clot. U/S exams detected clot in 6/9 patients. The remaining five patients exhibited clinical signs requiring operations rather than diagnostic studies. The only consistent laboratory abnormality was an elevated white blood cell count in 12/15 patients. Management of MVT varied. Five patients, heparinized once the diagnosis was made, did not experience dysfunction from MVT. Ten patients were not initially treated with heparin and were divided into three groups. Three patients received neither heparin nor surgery and have had no sequelae. MVT contributed to the death of two patients. The remaining five patients were diagnosed in the operating room following bowel resection. Two of these patients received postoperative heparin and had a favorable outcome. Two of the three patients not heparinized after surgery suffered additional bowel infarction. MVT can present as nonspecific abdominal pain, but also as peritonitis requiring operation. CT and U/S can identify patients with early MVT. It appears that heparin has both a primary therapeutic role in early disease and a postoperative adjunctive role in advanced disease. With such care, these patients can expect an acceptable prognosis (86% survival).

Epidemiology of insulin dependent diabetes before age 20 in Wisconsin, with particular reference to seasonality

Physicians in the State of Wisconsin were contacted by mail and asked to report all cases of diabetes in patients under 20 yr diagnosed between 1 July 1982 and 30 June 1984 in order to study factors associated with seasonality in insulin-dependent diabetes mellitus (IDDM). Wisconsin's population is fairly homogeneous and is primarily middle socioeconomic class, small-town or rural, and of northern European Caucasian descent. The incidence of IDDM in winter was higher than in summer during the first year of the study, similarly to results of other studies. However, there was no significant winter peak in diagnosis during the second year. When monthly incidence rates from both years were combined, the increased evidence of IDDM in winter vs. summer was evident in males, but not in females. There appeared to be a spike in the number of new cases of IDDM in the first year of the study which was more evident in males. Such a spike is consistent with spikes in the incidence of IDDM occurring about the same time in Europe and in North America. The percentage of patients with antibody titres to Coxsackie virus and mycoplasma pneumoniae diagnosed during the first winter's peak were equal to those in nondiabetic controls. The distributions of HLA DR types of patients diagnosed in winter were no different from diabetics diagnosed in other seasons. The distribution of HLA DR types (5% DR2, 55% DR3, 82% DR4 and 38% DR3DR4) were similar to those of other groups of Caucasian subjects with IDDM. Also similarly to other studies of IDDM, 14% of the patients had thyroid microsomal antibody titers. The results of this study support the previously-advanced idea that winter might precipitate overt carbohydrate intolerance in individuals in whom insulin cell destruction is already well established (Diabetes, 36, 265-268, 1987). If this is true, studies of seasonality in IDDM might not be informative about the causation of IDDM.