15 Raynaud’s Phenomenon and Sjögren’s Syndrome |
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There is evidence of a defect in natural antioxidants and an increase in oxidative stress in patients with scleroderma, thus justifying trials or empiric use of antioxidant therapies [91]. Benefits of antioxidants remain to be demonstrated in clinical trials, but studies of N-acetylcysteine and probucol suggest that antioxidant therapy decreases the severity and consequences of RP [92, 93].
A variety of agents have the potential to prevent digital ischemia indirectly by their vasoprotective properties. These include antiplatelet agents, statins, prostaglandins, thrombolytics, anticoagulation, antithrombin agents, rho kinase inhibitors, and antioxidants. At this time, few formal studies are available to inform guidelines about their use. The author regularly uses low-dose aspirin therapy (81 mg) in scleroderma patients with significant vascular disease because there is evidence of platelet activation in those patients. The indications for using aspirin in SS are less clear.
15.3Surgical Options
15.3.1Sympathectomies
The thermoregulatory vessels in cold temperatures are normally under increased sympathetic tone. Thus, the disruption of sympathetic nerves to the limbs or fingers should result in vasodilatation and improve local blood flow. Both proximal and digital sympathectomies are used for the treatment of RP and are reported in uncontrolled case series to be effective [94–97]. Long-term follow-up of patients who have undergone sympathectomies suggests that the RP eventually returns but the severity is improved and subsequent digital ulcers are less likely. The author typically employs digital sympathectomies in patients who have failed medical therapy, who have evidence of critical digital ischemia, or are in an urgent situation of acute digital ischemia that threatens the viability of the digit. Surgical sympathectomy is not recommended for RP alone.
15.3.2Management of Critical Digital Ischemia
Digit-threatening ischemia should be considered a medical emergency that requires hospitalization. In patients with SS, a careful investigation of a secondary process causing microand macrovascular disease is essential in that a reversible disease process is often causing the ischemic event (Table 15.3). Deeper tissue ischemia with infarction is usually associated with structural disease of larger vessels, inflammatory damage to vessels, and/or acute thrombosis. When persistent ischemia is clinically present (i.e., a painful, pale digit), then vasospasm of the superficial thermoregulatory vessels is usually coupled with occlusion of small nutritional vessels or larger proximal vessels, leading to low blood flow and critical tissue ischemia.
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F.M. Wigley |
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Table 15.3 |
Workup |
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• Nailfold capillary microscopy |
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for digital ischemia |
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• Examination: BP, pulses, bruits, Allen’s test, provocative testing |
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• Comprehensive laboratory data |
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• Arterial Doppler |
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• Radiology |
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– Conventional angiography: Lumen
– MR-angiography: Lumen, vessel, and tissue
– CT-angiography: 3 dimensional
Table 15.4 Managing acute digital ischemia
•Rest and warm
•Control pain
–Local digital block
•Start vasodilator:
–Calcium channel blocker
–If no response add a second vasodilator agent:
•PDE-5 inhibitor
•IV prostaglandins
•Novel preventive therapy
–Statins
–Antiplatelet: ASA 81 mg
–Antioxidant therapy
•Surgery
–Digital sympathectomy
–Vascular repair
A rapid therapeutic intervention to prevent tissue infarction is required. This can be started by placing the patient in a warm ambient temperature, providing bed rest to decrease trauma and activity of the involved limb, and instituting appropriate pain control. Although systemic narcotics are known to be vasoconstrictors, their use may be necessary to control pain while other therapy to reverse the event is started. A local injection of lidocaine or bupivicaine at the base of a finger with critical ischemia can give rapid improvement, both in terms of pain and occasionally with improved blood flow by reducing sympathetic tone. Repeat injections or a local regional block can be done while waiting for other vasodilator therapy to take full effect. Vasodilator therapy should be started immediately and maximized rapidly (Table 15.4). A short-acting calcium channel blocker (e.g., nifedipine) is an appropriate choice, and it should be titrated to the highest tolerable dose. In cases of rapidly progressing ischemia that fails to respond to standard oral vasodilatory therapy, intravenous iloprost, alprostadil, or epoprostenol can be given. For patients who have rapidly advancing ischemic tissue, anticoagulant therapy is initiated. Although no formal studies exist, the use of heparin for 24–72 h during an acute crisis makes sense. Chronic anticoagulation is not recommended unless an associated hypercoagulable state is discovered. When medical therapy fails, several