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Biomedical subjects

J F Van Cleef

Publications and source records attributed to J F Van Cleef.

11 recordsLinked to original sources
PubMed1992

[Endoscopic study of reflux of the saphenous valve].

Saphenous venous endoscopy, invasive and non-physiological, enables the in vivo and in situ observation of the valve system. A saphenous vein has a preferential flattening axis parallel to the outside of the skin with two walls, internal and external, and two borders. A valve is inserted on one vein wall, with the valve horns being on the borders. The free borders of a bivalve are parallel with the surface of the skin. The valve system has an antireflux function. There are three main causes of reflux in the saphenous veins: 1. Transitory functional incompetence affecting valves of normal appearance. This incompetence results from valve inertia, flattening of the valve against the sinus wall and loss of co-adaptation. Do active factors producing closure of the valve cup exist against such transitory incompetence? 2. Incongruity between the vein wall and valves. The intercorneal or commissural space allows reflux on the border of the vein. This is the commonest cause of reflux in varicose disease of the vein wall. 3. Actual valve lesions. A distinction is drawn between lesions due to thinning, elongation, stretching, splitting or tearing and those due to thickening, retraction or adhesion. Endoscopy has enabled us to discover cases of varicose disease with predominantly valvular lesions in young individuales in whom early lesions of the valve cup cannot be explained by venous wall disease and has led us to complete the classification of varicose disorders.

Endoscopy↗
PubMed1991

[Venous endoscopy].

The miniaturization of endoscopic equipment now allows exploring the superficial venous system and visualizing the endovein in situ and in vivo. This type of venous endoscopy is an ambulatory procedure, performed during a simple outpatient consultation of angiology, after which the patient is immediately discharged. Although this examination is invasive, non-physiological and expensive, it allows the video recording of the morphology, dynamics and kinetics of the values, of the endovein and of the liquid flows (blood, washing fluid and sclerosing products). The new examination has already enabled us to propose an functional classification of the parietal valves of the great saphenous vein. It makes an intraoperative three-dimensional mapping of the vessels possible, which is sometimes difficult in such particular anatomical regions as the popliteal fossa. It allows performing sclerosis with a visual control and following up the evolution of the immediate endoparietal lesions in situ.

Ambulatory Care↗
PubMedDate not supplied

[A dynamic model of the muscular pump of the calf in deep venous insufficiency].

The dynamic model described in 1989 is characterised by the emptying of blood from perforators into the deep venous column (DVC) during a muscle contraction. Muscular squeezing and convective acceleration favor such emptying. In 1990, using dynamic venous endoscopy, it was possible to define the following for a saphenous vein: an outer (or deep) surface, an inner (or superficial) surface and two edges. In 1992, it can be said that the deep veins also have two surfaces and two edges. Anatomically, valve commissures are on the edges of the veins which are also known as commissural lines. Physiologically, this zone (edge of the vein) is potentially less collapsible. Diagrams of models of muscle pumps require modification: valve commissures and orifices of perforators must be aligned. Fluid flow (flux and reflux) is more durable along the edges of the vein.

Humans↗
PubMedDate not supplied

[Sclerotherapy of the external saphenous vein under endoscopic control].

The contribution of investigative venous endoscopy is essential. This out-patient endoscopic technique visualises the venous endothelium, valve systems and collaterals. For example, this technique enabled J.F. Van Cleef and C. Ribreau to draw up an anatomo-physiological classification of the parietal valves of the long saphenous vein on the basis of video films. From a therapeutic standpoint, venous endoscopy has yet to show its value. We chose the short saphenous since treatment of incontinence of this vessel is difficult and controversial: difficult because of anatomical variations, notably its ending and because of its course in the popliteal fossa; controversial because of its relations with the gemellary veins. Treatment of the short saphenous, whether medical or surgical, is not always entirely satisfactory. In case of surgical treatment, together with J.P. Hugentobler, we had already noted the value of three-dimensional localisation by transcutaneous illumination of the precise course of a vein using the cold light of the distal tip of the endoscope. "Venous ligatures" which can be placed intravenously are not currently available. In case of medical treatment by sclerosing injections of the short saphenous junction under endoscopic control, the product used can be injected with great topographical precision and strictly intravenously. Large amounts of product can easily be injected. However, this technique has at least three disadvantages: it is expensive; there is no parallel between endovenous lesions immediately visible by endoscopy and the mid-term results of sclerosing injections; the relations between the gemellary veins and the short saphenous can be identified precisely only by prior ultrasonography. As a result, sclerosing injections under endoscopic control remain within the domain of research.

Catheterization, Peripheral↗
PubMedDate not supplied

[Is phlebosuction possible?].

Phlebosuction is possible. It permits to increase the congruence between the venous wall and some surgical instruments. Phlebosuction cannulas currently allow "excision-thrombectomy" of a thrombosed varicose cord and some vein removals.

Catheterization↗
PubMedDate not supplied

[The "new electrocoagulation" in phlebology].

Today, electrocoagulation benefits from technical improvements, at the level of high frequency electronic generators as well as the composite needles of monopolar electrocoagulation. Thereby, in phlebology, electrocoagulation could again have some indication.

Electrocoagulation↗