How can we improve results of treatment?

Factors leading to venous ulceration:

1. Impairment of the muscle pumping mechanism of the leg due to disease of the superficial venous system secondary to varicose veins (20-50% of venous ulcers) or due to incompetence of valves of the deep system (previous DVT or primary failure). Such patients cannot reduce foot vein pressure below the resting level. This leads to venous hypertension, setting the scene for other factors to cause venous ulceration.

2. Browse and Burnard proposed that a cuff of fibrin formed around capillaries in patients with venous disease, which reduced oxygen diffusion into the skin. However, this has never been conclusively proved.

3. White cell trapping. Coleridge-Smith and others have suggested that in patients with venous disease, there is reduced venous flow on standing, leading to white cell margination and activation with release of free radicals, proteolytic enzymes and cytokines that cause local tissue injury.

4. Vascular proliferation in liposclerotic skin. Whether this makes an active contribution to ulceration is unclear.

5. Development of a type of peripheral naturopathy with loss of neuronal regulation of the microcirculation in the skin. This probably acts together with the mechanism described in 3.

6. Venous disease damages lymphatics in the skin eventually destroying them. This may account for the swelling of the legs often seen with venous ulcers.

Leg ulcer healing and recurrence

In the Skaraborg study of the natural history of leg ulcers, the overall long term healing was poor. Only about half were free of ulceration at the end of 54 months. 45% still had open ulcers or had undergone amputation. The subgroup that did the worst in this study was the one with venous ulcers and deep venous insufficiency (DVI). Recurrence of venous ulcers after compression bandaging varies between 30and 57%.

Diagnosis

To label every leg ulcer as a venous ulcer would be to oversimplify the problem and result in the wrong treatment being chosen. The classification by Nelzen gives a good idea what should be kept in mind when dealing with leg ulcers.

 i. Venous ulcer - due to venous insufficiency without another  cause. Forms 55% of all leg ulcers and 70% of ulcers above the foot.

ii. Mixed venous/arterial ulcers - predominately venous but some arterial impairment; ABI 0.7 - 0.9.

iii. Mixed arterial/ venous ulcers - predominantly venous due to superficial vein incompetence with ABI of < 0.7.

iv. Arterial ulcer - no venous factors. ABI < 0.7; usually painful.

v. Arterial and diabetic ulcers - combination of arterial insufficiency and diabetic neuropathy.

vi. Diabetic ulcers - due to diabetic neuropathy. Usually deep and painless and usually on the foot.

vii. Traumatic ulcers - obvious history of trauma. Normal ABI and no obvious venous disease.

viii. Pressure ulcers - usually buttocks or feet. No obvious venous or arterial disease. Associated with prolonged confinement to bed.

Clinical diagnosis should be supplemented with a hand held Doppler examination to detect arterial and venous insufficiency. Failure to do this means a wrong diagnosis in I in 4 patients. In more complex cases, a duplex Doppler examination should be obtained.

Treatment

1. Compression Bandaging (CB)

In our Trust we have a main hospital based ulcer clinic, which takes referrals from hospital consultants, OP surgeries, and fronl3 community clinics. These clinics are run by nurses with training in tissue viability and compression bandaging. Patients presenting with leg ulcers have a venous and arterial assessment. This may often include an arterial and venous duplex and a biopsy. Our first line of treatment is a course of compression bandaging. If the ABI is 0,8 or more, this will be 4-layer compression. If ABI is 0.6-0.7, a 3-layer bandage will be applied and the patient referred for a vascular opinion.

        Healing rates for CB are:

        Venous ulcers                66% - 12 weeks

                                                 89% - 24 weeks

        Mixed ulcers                   42% - 12 weeks

Indications for referral of leg ulcer patients to a vascular surgeon:

• ABI of 0.6 or less.

• Patients who would benefit from venous surgery (active/mobile) once their ulcers are healed. This reduces recurrence rates.

• Recurrent ulcers.

• Ulcers not responding to compression bandaging.

2. Surgery

Ninety percent of all ulcers are associated with a detectable deficiencies, arterial or venous and 40% can be cured with surgical procedures. Half of all venous ulcers are due to superficial/perforating venous insufficiency, which is eminently dealt with surgically. Venous ulcers treated surgically have a less than 10% recurrence rate. There is no evidence to support continual conservative treatment of venous ulcers once they have been healed with compression bandaging. In fact there is evidence that long standing superficial or perforated vein incompetence may progress through the venous system, which may then become no longer amenable to surgical cure.

The normal venous procedure for such patients is the high tie and strip of the long and/or short saphenous veins with multiple phlebectomies. More recently endovenous laser ablation or VNUS ablation of incompetent superficial veins is being used. Subfacial Endoscopic Perforation Surgery (SEPS) can be used to clip incompetent perforations through an endoscope inserted via a small incision in the calf into the subfascial space.

Arterial ulcers should be treated with bypass surgery or angioplasty. Mixed arterial/venous ulcers are a difficult group to treat. We normally try modified 3-layer compression to heal the ulcers. If this does not work we would do an angiogram and venous duplex ultrasound. If the arterial component could be treated with angioplasty, we would do this and assess the result. If this were not possible, then an acceptable alternative would be to perform a bypass using the incompetent superficial vein as a conduit thus dealing with both problems at once.

References:
Venous Disease: Epidemiology, Management and Delivery of Care. Ed Ruckley CV, Fowkes FER and Bradbury AW.