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INJECTION  SCLEROTHERAPY

W. G. FEGAN

I have been treating varicose veins by injection compression sclerotherapy for twenty-five years, but I feel that the difference between the good injection technique and the bad injection technique cannot be stressed too often.

The ideal result is that the venous return pumping mechanism is restored by an injection technique which indicates the development of fibrosis in the narrowed thickened wall of the collapsed vein, achieved by compression and walking until fibrosis is complete, and if a small segment of vein is chosen opposite to the incompetent perforator then the restoration of the venous pumping mechanism is long lasting and damages neither valve not the muscle in the vein wall.

Derangements of the venous pumps are due to valvular incompetence. Let me distinguish between primary and secondary incompetence. By primary incompetence I refer to those destroyed valves, the cusps of which have become fouled by thrombosis and recanalization, this is the common cause of leakage through the perforating veins.

Secondary incompetence develops with the gradual dilatation of the superficial vein in an upward direction from the site of such a leak and it is reversible because the valve cusps are still normal and have not been permanently damaged. The only abnormality lies in the stretching of the valvular ring and this will recover soon after the incompetent perforating vein has been destroyed.

Secondary incompetence, in contradistinction to primary, is reversible and greater advantage should be taken of this reversibility in the treatment of varicose veins.

Widespread thrombosis with recanalization of veins and destruction of valves followed the old form of injection treatment.

This was not generally understood because of the temporary improvement following the treatment and prior to thrombus recanalization.

The prevention of reopening is one of the principal objectives of our treatment. The reasons for reopening of veins after thrombosis are as follows:

1. Retraction of the clot to the side of the lumen to which it is most firmly attached.
2. The water-hammer effect of the blood in the unthrombosed segemnt of vein which gouges a line of cleavage between the retracting thrombus and the weakened vein wall.
3. The natural tendency of the normal lining of the vein wall to proliferate and split, forming sinuses which soon establish connection with the venous system.

Failure to isolate the segment of vein at the time of injection may result in a larger area of vein damage than is required. Failure to empty the vein of blood at the time of injection, and also failure to maintain adequate compression of the area afterwards, is likely to result in the production of thrombophlebitis, poorly controlled or not controlled at all. The selection of the site of injection is of the greatest importance, for failure to control the site of reflux filling of the superficial veins will defeat the object of the treatment.

Even if the injection has been correctly performed, unless the area is adequately compressed the changes in venous pressure will tend to force a passage through and so thrombophlebitis may develop at the site. Failure to maintain continuous compression until a firm fibrous occlusion occurs will result in recurrences. The immediate object of injection compression sclerotherapy is to produce a permanent fibrous occlusion at the sites of incompetent perforating veins. Perforating veins connect the deep and superficial veins and in doing so pierce the deep fascia. They have valves, and the flow of blood normally is from superficial to deep veins. If the valve is incompetent in the perforating vein, flow from deep to superficial veins occurs. The superficial veins are subjected to abnormal pressures of blood, and varicose veins result.

The success of injection compression sclerotherapy depends on the facts: (1) that in the majority of patients with varicose veins and, in almost all those with symptoms incompetent perforating veins are present; and (2) that if these incompetent perforating veins are permanently occluded the superficial veins, no longer subjected to an abnormal blood flow, are capable of regaining their normal tone and diameter and the valves in them regain their competence. The aim of the injection technique is to prevent abnormal pressures and retrograde flow from the deep to the superficial venous system. To achieve this successfully, the sites of incompetence must be located exactly.

The patient should be examined first sitting on a couch with the legs horizontal. All visible veins should be marked with a skin pencil. Palpation and percussion of these vessels will help to detect those parts of the system that are affected and they may be partly camouflaged by subcutaneous fat. Then, with the patient lying down and the leg raised high to empty the veins, the deep fascia of the leg is palpated to detect openings that may transmit perforating veins; these sites should also be marked. Fascial defects are usually associated with the dilated complex of veins that have been marked previously. With a finger placed firmly over as many of these sites as possible the patient stands on the floor; if the incompetent perforator has been occluded there will be no abnormal dilatation of the veins. One finger at a time is now released, and when filling of the superficial complex is observed, the incompetent perforators are marked.

The skin is prepared as usual for an intravenous injection. The needle is introduced into the vein at the site of perforator incompetence with the patient sitting on the couch. The patient is asked to lie back and the leg is elevated so that the veins are emptied of blood taking care that the needle remains in situ. Two fingers are placed on the vein, one on either side of the needle. The isolated segment of the vein should be thoroughly emptied of blood before the injection is commenced. A half to one millilitre of the sclerosant , sodium tetradecyl, is gently injected into the isolated segment, and held there by the fingers whilst the syringe is removed. With the segment of vein still isolated and the leg raised a three inch bandage is applied to the leg. A specially prepared sorbo rubber pad is placed over the injection site between the layers of bandage as the isolating fingers are removed.

As many injections as are required are given in a similar way and the whole limb is bandaged. The technique of bandaging is as important as is the diagnosis or the injection. The compression must be firm but comfortable and must remain all the time until the patient next visits the clinic. A full length two-way stretch elastic stocking is fitted over the bandages and the patient instructed to walk immediately for one hour and for three miles every day.

On subsequent visits any further injections that may be required are given. The reaction to the previous injections are observed. The reaction in the vein should be confined to the isolated segment. If the segment was empty of blood at the time of injection, the subsequent compression was adequate, and the patient walked diligently each day, the result will be a small relatively painless, fibrous string. Compression must be maintained until fibrosis is complete, which is usually six weeks from the date of injection.

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