The Effect of Adventitia Stripping in Refractory Ischemic Digits

Abstract

Ischemic disease of digits is a very frustrating and extremely difficult clinical problem. It is often caused by a variety of diseases, such as atherosclerosis, connective tissue disease, trauma and Raynaud's disease. Patients with this problem usually suffer from poor tissue perfusion and impaired microcirculation. In clinical, ischemic digits often present with pain, cold intolerance, ulceration and even gangrene change. Many strategies are proposed today to overcome this disease. Behavioral therapies, such as avoidance of cold exposure and smoking are a very important intervention. Pharmacologic therapies, like the administration of calcium channel blocker, PGE1 and other vasodilators have been the most commonly used agents. Sympatholytic drugs have also been added to reduce the sympathetic tone in vascular smooth muscles. In addition, anticoagulants or antiplatelet agents are administered to inhibit thrombus formation in occlusive vascular disease. Although these agents are usually effective, unfortunately, in refractory cases, amputation is unavoidable. Those patients have to suffer the fate of partial or total loss of the digits. This ultimate outcome frequently comes with high morbidity and dysfunctions both in physical and psychological terms. In those cases which are refractory to medical therapy, surgical intervention had been carried out to improve tissue perfusion. Tissue perfusion depends on the integrity of the vasculature and the neurovascular regulatory elements. Historically, microsurgical revascularization and sympathectomy were widely performed to recover adequate blood flow. Microvascular reconstruction with interposition vein grafting can be used to reestablish the vascular structure. However, not all cases with digital ischemia are suitable for this procedure due to the possible occurrence of multifocal stenosis. Sympathectomy can reduce sympathetic tone and thus increase the radius of blood vessel. According to Poiseuille's law, blood flow is directly proportional to the fourth power of the vessel's radius. So even a small increase of radius of blood vessel can lead to a very great increase in blood flow. According to Pick and Flatt, sympathetic fibers travel along the epineurium of peripheral nerve, pass to the adventitia, and innervate the smooth muscle of vessels. The removal of adventitia can block the sympathetic tone in the smooth muscle. This procedure may also increase the radius of vessel and reestablish adequate blood flow.