Evaluating the competence of venous valves preserved with denaturation in cold ischaemia.

AIM OF STUDY: The aim of this study was to evaluate the competence of venous valves preserved with denaturation in cold ischaemia. MATERIAL AND METHOD: Eight segments of saphenous veins with 20 competent valves were analysed in the study. The material was collected during multiorgan retrievals. After harvesting, 15 cm long venous fragments were assessed with respect to valve presence. A 4-cm fragment with a valve was used for the analysis. Valve competence was assessed twice: after sampling and after 21 days of preservation. The valves were subjected to 136 cm water column pressure test. Denaturation in cold ischaemia consists of preservation of vessels at 4_C in a preservation medium containing antibiotics. Bacteriological and morphological examinations by light microscopy were performed. RESULTS: After the preservation period, all the valves retained their mechanical properties. Well-preserved elastic elements of vascular wall were maintained in all vessels. Minor fragmentation of elastic fibres was observed and the structure of vascular wall was usually regular. CONCLUSIONS: Our study indicates that denaturation in cold ischaemia allows for the maintenance of the properties and physiological functions of the valves after preservation. This effect is related to the good condition of elastic fibres, venous wall structure and the valve itself.

Nailfold capillary microscopy in patients with anticardiolipin antibodies: a case-control study.

BACKGROUND AND DESIGN: This case-control study was undertaken to determine whether anticardiolipin antibodies (ACA) are responsible for particular abnormalities in nailfold capillary microscopy (NCM). Cases comprised 33 consecutive patients positive for ACA (24 women and 7 men). Controls comprised the same number of ACA-negative patients, with the same sex ratio, the same diagnosis and the most similar duration of disease possible. Clinical data, serum samples and NCM recordings were obtained from all patients and controls. RESULTS: In each group, 22 patients had connective-tissue-related disorders and 11 various other diseases. In ACA-positive patients, the mean IgG ACA titre was 39 +/- 58 IgG phospholipid units. Cases and controls displayed various cutaneous manifestations. In ACA-positive patients, there were Raynaud's phenomenon (54%), cutaneous vasculitis (24%), scleroderma changes (18%), photosensitivity (9%), a history of digital gangrene (6%), malar rash (6%), acrocyanosis (6%), chilblains (3%), livedo reticularis (3%) and purpura (3%). Cases and controls exhibited numerous NCM abnormalities. In ACA-positive patients, they included haemorrhages (54%), oedema (24%), bushy capillaries (21%), disordered capillaries (18%), capillary bed disorganization (12%), capillary rarefaction (9%), giant capillaries (6%) and 'desert areas' (3%). There were no correlations between the ACA titres on the one hand and the number of cutaneous manifestations or NCM abnormalities on the other. CONCLUSIONS: ACA-positive patients frequently exhibit clinical skin lesions and abnormal NCM. In this study, these lesions and NCM abnormalities resembled those of the matched ACA-negative controls.

[Atheromatous embolisms and cholesterol embolisms: medical treatment]. / Embolies athéromateuses embolies de cholestérol: traitement médical.

In patients with an acute arterial occlusion, identification of the type of mechanism is important, because both prognosis and treatment differ for each type. The aorta is the most frequent source of arterial atheromatous emboli. Aortic arch plaques are therefore recognized as an independent risk factor for stroke, and plaques located on the thoracoabdominal aorta embolize in the visceral arteries or limb circulation. The treatment of risk factors seems the most effective preventive treatment. When atherosclerosis is patent, an anti-platelet drug such as aspirin or ticlopidine is useful. When the embolus actually occurs, heparin avoids extension of thrombus and prevents its recurrence. Surgical treatment is logical but has not been supported by any randomized trial. Cholesterol cristal embolization evolves in 3 clinical forms: 1-the paucisymptomatic form, not diagnosed during subject's lifetime and only recognized in autopsy studies; 2-a benign form such as the blue toe syndrome or cutaneous livedo, with a spontaneous mild prognosis, and 3-a diffuse multisystemic form with a very poor prognosis. More than 80% of patients with the diffuse form die. When there is renal involvement, only 25% are still alive, with renal function after 6 months of follow up. Vascular surgery is limited to patients with aneurysms, which in themselves constitute a surgical indication. For all other patients, surgery is rarely indicated because 1-the source of cholesterol cristal embolization is not certain, 2-patients are usually too weak for a major surgical intervention, and 3-the necessary aortic clamping during surgery would induce a major risk of recurrence. Prevention is the most effective treatment because in 30% of patients, embolization is due to one of the following: anticoagulant drug, recent fibrinolysis, percutaneous angioplasty, vascular surgery, diagnosis angiography and/or coronarography. The medical treatment is mostly symptomatic: rest, warm conditions, appropriate dressing, antiplatelet drugs, hydration, and organ supply when necessary, principally to ensure renal function. In diffuse and multi-visceral embolization, either colchicine or corticosteroids adjuvant therapy might be useful Prostanoid drugs are also a possible adjuvant treatment.

[Treatment of an exposed femorol-popliteal bypass: ex-situ replacement]. / Traitement d'un pontage fémoro-poplité exposé: remplacement ex-situ.

From December 1990 to July 1995 we performed 171 sub-inguinal revascularizations including 35 popliteal revascularizations and 146 revascularizations of an artery in the leg or foot. Five cases of infection were observed within a delay of 7 and 25 days after the operation. There were 3 men and 2 women (mean age 78 years). Four femoro-tibial bypasses were made for critical ischaemia (2 necroses of the toes, one eschar of the heal, one stage III). There was one femoro-popliteal bypass which was associated with a femoro-femoral for necrosis of the toes. Two bypasses were made with polytetrafluoroethylene, one with Dacron and two with the greater saphenous vein. Signs of sepsis were bleeding in 2 patients who had a venous bypass and septicaemia in 2 patients. Local skin necrosis and/or apparently infected discharge or patent pus were seen in all patients. Staphylococcus aureus was found in 4 patients and Enterobacter cloacae in one. Revascularization was done with an extra-anatomic bypass in 4 patients and with a cryopreserved in situ allograft in 1. Mortality was 20% and amputation rate was 40%. All exposed bypasses were infected but the severity of the infection varied depending on the causal germ, general signs and ischaemia of the limb. Conservative treatment has its limits: 1) intact anastomoses, 2) absence of bleeding, 3) patent bypass, 4) absence of generalized sepsis. Results of in situ revascularization depend on the virulence of the causal germ. Radical treatment (explanation + extra-anatomic revascularization) still has indications in infected infra-inguinal bypass surgery.

[Medical treatment of aortic aneurysms using beta-blockers]. / Le traitement médical des anévrismes de l'aorte par les bêta-bloquants.

There is no known treatment capable of avoiding extension and rupture of aneurysms of the abdominal aorta. There has however been much work recently suggesting a favourable effect of beta-blockers. Early work with experimental animal models of aortic aneurysms showed that Propranolol has a protective effect on extension and rupture of these aneurysms. Studies of the biochemistry of the aortic wall have shown that Propranolol has an independent effect on blood pressure, stimulation lysyl-oxidase and production of intermolecular elastin bridges which strengthen the arterial wall. In man, Propranolol slows the progressive dilatation of the aorta in Marfan's disease. These data on atherosclerosis aneurysms are only part of the picture, but 3 studies have shown that slower widening of the aorta diameter is related to treatment with beta-blockers. In conclusion, the surgical indications for aneurysms in 1995 are unchanged from those in 1994. In cases where surgery is not indicated (patient refusal, operative risk too high, small aneurysms) could comprise a study group for a randomized evaluation against placebo of the effect of beta-blockers. A controlled study is required before therapeutic strategies can be modified.