Perspectives in Circulation Today

Venous Ulcers and Stasis Dermatitis

Pathophysiology and Treatment of the Difficult Patient

Yes, patients whose ulcers have defied standard treatments can be cured with boot therapy. Further, pigmentation associated with stasis dermatitis may be greatly reduced and leather- like skin may be rendered soft and pliable. Here we briefly review the pathophysiology and treatment of venous stasis disease and explain the benefits of intermittent compression therapy.

Incidence: Venous disease is largely a problem of older patients. Among those over 50 stasis disease is found in 6-7%. Among those over 70, the prevalence may be greater than 20%.

Risk factors: Chronic venous hypertension is the common thread among factors associated with venous disease: obesity, standing occupations, corsets, garter belts, Baker's cysts, pregnancy and intraabdominal masses. Among younger patients, one might consider thrombophlebitis associated with abdominal and pelvic surgery, trauma or hereditary clotting disorders (deficiency of protein "C" or "S" or deficiency of antithrombin III).

Pathophysiology: Venous hypertension to venous dilatation to incompetent venous valves to more venous hypertension in a cascading fashion leading to especially high pressure in the distal more dependent portions of the leg and its dermal microcirculation. Such pressure increases the permeability of dermal capillaries promoting edema and leaking macromolecules, such as fibrinogen, into the pericapillary tissue where fibrin cuffs form around the dermal capillaries. A decrease in dermal fibrinolytic activity may also promote the formation of the fibrin cuffs. Such fibrin cuffs are characteristic of tissues damaged by venous hypertension. The cuffs might act as a barrier to oxygen diffusion resulting in tissue hypoxia, cell damage and dermal fibrosis. Activated leukocytes become trapped in fibrin cuffs and the surrounding perivascular space and release inflammatory mediators that contribute to the inflammation and fibrosis. The development of microthrombi, extravasation of red cells, deposits of hemosiderin and pigmentation complete the picture. Perhaps, because of hypoxia or in reaction to inflamation, blood flow in the area may be increased. The drop in oxygen tension may be accentuated if infection with aerobic bacteria develops and the oxygen tension may become too low to maintain the integrity of the tissues. The importance of reflux and its effect on the overall circulation in the leg is to be emphasized not only in understanding the pathophysiology of the disease but in appreciating the need to surgically reduce reflux when possible. Superficial varicosities always produce some recirculation of the venous outflow and slow the clearance from the leg of labeled blood injected into the femoral artery. The amount of delay is highly correlated with the formation of venous ulcers.

Symptoms: Early in their course varicose veins may have minimal symptoms. Especially women may complain of their appearance. With time progressive complaints in the distal leg are common... slight burning, heaviness or tension, itching, aching, restless legs, cramps and swelling ... all worsened by pregnancy or periods of standing. Episodes of superficial phlebitis may accelerate the progression of symptoms and damage venous valves in spite of adequate anticoagulation therapy. Note that patients presenting with superficial phlebitis above the knee have perhaps a 1 in 5 chance of having deep vein thrombi requiring heparin anticoagulation.

Vascular Physical Findings in Patients with Obstructed Venous Flow and/or Venous Valvular Insufficiency:
Venous filling time: On the dorsum of the foot, venous filling is largely due to arterial inflow. Such veins fill in less than 15 seconds when the raised leg is dropped to the dependent position. The veins in the calf take longer and in the normal leg are not as easily visualized.
Venous pressure: In the supine position the the leg veins normally empty when the foot is raised just above the right atrium. Patients with venous hypertension due to outflow obstructions, arteriovenous fistula or erythromelalgia must elevate their legs to a higher level.
Trendelenburg Maneuver: As the patient stands up from the supine position, the speed and extent of venous filling in the superficial veins are noted (a) with no local pressure over any portion of the saphenous vein, (b) with local pressure on some portion of the saphenous vein, and (c) on release of a pressure point over the saphenous vein. A significant reduction in filling with the application of pressure and a sudden rush in filling with the release of pressure both provide good evidence that the patient may benefit from ligation of the saphenous vein where the effects of the application of pressure were most marked.
Ballottement of the veins: In the standing position, tapping on the upper portion of a distended vein creates an impulse that may be felt distally if the intervening valves are incompetent. A distance of 20 or more cm between the tapping and sensing fingers generally signifies an incompetent valve.

Tests Used in the Diagnosis of Venous Diseases:
Older tests available in the doctor's office that may provide numbers for research and serial testing (the latter are best done the same time of the day) and lend insight into the function of the venous system:
Maximum Venous Outflow (MVO) with a strain gauge or pneumo plethysmograph. The test may document a significant obstruction to venous outflow in the lower leg from any cause. It measures the time from the removal of an obstructing thigh tourniquet for the maximally congested lower leg to return to the basal state. It is a functional test not an anatomic test, and is sensitive to venous obstruction of any cause at almost any level. Thus, it may be abnormal due to obstruction in the calf and the pelvis where ultrasonography and venography are insensitive. A normal MVO result does not absolutely rule out DVT.
Venous reflux with PPG. Veins of the lower leg are normally refilled only by arterial inflow which may require 2 or more minutes. Venous refilling times decrease in patients with increasing degrees of venous valvular insufficiency: asymptomatic patients with mild disease, perhaps 40-120 seconds; patients with more significant disease and symptoms of nocturnal leg cramps, restless legs, leg soreness, burning leg pain, and premature leg fatigue perhaps may require 20-40 seconds; patients with times under 20 seconds are almost always symptomatic; finally those with times under 10 seconds may expect venous ulcerations.

Venography ... invasive... historic gold standard... not conducive to repeated studies... potential allergy and toxicity from contrast media.

Ultrasound Studies:
Hand-held Doppler noting respiratory variation, loss of flow with Valsalva maneuver, augmentation of flow with squeezing of distal tissue and release of proximal tissue and production of reflux flow with squeezing of proximal tissue. Multiple veins below the knee may be confusing.
Duplex scans: Most common screening method in hospitals today. The technique is more qualitative than quantitative and does not lend itself well to the production of numbers for serial studies or research. The scans are most commonly done in the hospital vascular laboratory in response to requests from physicians faced with patients with superficial phlebitis, varicose veins, possible pulmonary emboli, possible deep vein thrombi, complaints of unexplained leg swelling or leg pain. It is also done in evaluating the postphlebitic syndrome and in evaluating the saphenous vein for leg bypass or coronary bypass surgery. Compared to venography, the test is less helpful in searching for thrombi in the pelvis and below the knee.

Transcutaneous Oxygen Measurements: Some degree of hypoxia is always present in the skin adjacent to a stasis ulcer compared to uninvolved skin on the normal leg in the same location. A normal TcPO2 should lead the clinician to suspect an alternate diagnosis.

Prognostic Factors:
History and Presentation: Allowing 1 point for a history of an unhealed ulcer of 6 months or more and 1 point for an ulcer greater than 5 square centimeters, 98% of 110 patients with a score of zero healed within 24 weeks of standard care with compression bandages while only 13% of 57 patients with a score of 2 healed (Margolis et al 2000). In a larger data set of 20,000 patients, a wound less than 10 square centimeters and less than 12 months old had a 29% chance of not healing by 24 weeks of care while larger wounds with longer durations had a 78% chance of not healing (Margolis et al 2004).
Degree of ischemia: The degree of skin hypoxia may be unrelated to the increased arterial circulation of the deeper tissues and is perhaps the best best predictor of skin ulceration (Leu et al 1995).
Combined disease (venous insufficiency and arteriosclerosis obliterans): Elderly patients with combined peripheal arteriosclerosis and venous insufficiency have a poor rate of healing and a high mortality in spite of successful revascularization procedures (Bohannon 2002).
Degree of reflux: Patients with marked reflux (such as times under 10 seconds) fare poorly especially if treated in ambulatory clinics.
Morbid obesity: The morbid obese fare poorly and are likely to quickly relapse if healed.

Differential Diagnosis:
Asteatotic Eczema, Atopic Dermatitis, Cellulitis, Contact dermatitis due to allergy or irritants, Cutaneous T-cell lymphoma, Fungus and yeast infections, Kaposi sarcoma or Pseudo-Kaposi sarcoma, Melanoma, Necrobiosis lipoidica diabeticorum, Nummular dermatiis, Pigmented Purpuric dermatitis and Pretibial Myxedema may all complicate or mimic stasis disease. For more information on these entitites see our venous library and online sources like Emergency Medicine. Rarely other sources of fibrin cuffs are to be considered such as porphyria cutanea tarda and clinical ecthyma type ulcers (Neumann 1996).

Treatment of varicose veins, stasis dermatitis and venous ulcers:

Prophylactic measures and treatment of early symptomatic cases:
Supporting elastic hose to be worn when ambulatory and during prolonged periods of sitting.
Weight reduction and avoidance of tight garments.
Elevation of legs when feasible.

Early Surgical considerations:
Ascertain before removal of any portion of the superficial venous system that it does not represent the only route venous blood returns from the leg! Ligation of greater saphenous to correct venous reflux.
Ligation of any arteriovenous fistula
Spider Veins may respond to sclerotherapy

Conservative care of disease now manifested by stasis dermatitis with or without small ulcers of short duration:
Prescribed leggings/compression bandages such as Jobst stockings or CircAid leggings. The latter a favorite in that it has multiple tongues allowing pressure adjustment and a canvass-non-giving texture preventing swelling after hours of wear.
Topical Agents such as emollient creams (50% hydrophilic ointment, 2% zinc oxide and 48% water), topical steroids (a trial to the stasis dermatitis, not the ulcers), topical antibiotics (such as Silvadene cream), soak solutions (such as Sea Soaks and Sea Soaks Concentrate) and moisturizers (once any infection controlled) may all have a place. Honey is a cheap effective moisturizer. It may be helpful to place any agent prescribed on a band-aid and place it on the forearm to test for contact allergy if the possibility of allergy exists.
Pycnogenol either orally (50 mg three times daily) or topically or by both routes is a new promising agent still to pass the test of time (Cesarone 2006).

Intermittent Pneumatic Compression Boots: Helpful in all stages of venous dermatological disease once the microvascular complications described above have developed.
Historic role of slow-acting boots: prevention of thrombophlebitis during surgery, the postoperative state and prolonged bedrest especially in the latter for immobile or unconscious patients.
Mechanism of action and effects:
_____reduction of edema
_____prevention of stasis
_____stimulation of fibrinolysins.
_____Shortened venous outflow times(Blackshear 1987)
_____Improved cutaneous blood flow adjacent to ulcer (Malanin 1999)
_____Quickens healing of venous ulcers and decreases costs (Alpagut 2005)(McCulloch 1994)(Smith 1990)
Advantages of rapid-acting intermittent pneumatic boots which have all of the above actions but in addition:
_____Stimulate endothelial humoral factors (nitric oxide, prostacyclin, fibrinolysins and vascular endothelial growth factors) in proportion to the sheer force applied to the endothelium (Liu 1999, Toyota 1999).
_____Speed healing compared to slower-acting boots (Nikolovska 2005) and promote healing of chronic venous ulcers unresponsive to standard therapies (Dillon 1986)
_____End-diastolic pumping supports the heart and improves peripheral arterial blood flow. It is especially indicated in patients with combined venous, arterial and coronary heart disease (2nd illustration above), who have a poor prognosis for life and limb (Bohannon 2002).

Perspectives in Circulation Today

Volume 2, Number 1