Acute arterial occlusions of the small vessels of the hand and forearm: treatment with regional urokinase therapy

Repetitive Blunt Trauma and Arterial Injury in the Hand

INTRODUCTION/PURPOSE

Arterial injury in the hand is most often due to repetitive blunt trauma. Although not always associated with significant impairment, it may cause serious ischemic damage or considerable disability. As a cause of digital ischemia, the frequency of this disorder is widely under appreciated. This study reviews the clinical and angiographic features of this condition.

MATERIALS/METHODS

An extensive literature review combined with the authors experience with arterial injury in the hand due to repetitive blunt hand trauma is summarized with emphasis on mechanisms of injury and pathologic changes to explain the angiographic findings and clinical presentations.

RESULTS

Angiographic findings are related to severity of injury and underlying changes in the arterial wall. The clinical presentation varies from asymptomatic to digital necrosis and gangrene, related to severity of arterial injury, collateral circulation, and the highly variable arterial anatomy in the hand.

CONCLUSION

Early recognition is important because compared to many other causes of digital ischemia in the upper extremities, traumatic arterial injury is frequently readily treatable. Angiographic findings and clinical presentation are often characteristic. The diagnosis should not be based on a clear history of repetitive hand trauma since the patient may be unaware of this occurrence.

The role of thrombolytics in acute and chronic occlusion of the hand

Distal arm and hand ischemia from vessel thrombosis or embolism remains a difficult clinical challenge. The causes of ischemia are variable and include connective tissue disease, embolism, atherosclerosis, and iatrogenic etiology. Although reports are limited, treatment with catheter-directed thrombolysis has favorable results in cases of acute thrombosis, with most patients (80%) demonstrating improvement. Digital amputation rates are less than 10% and the hand is often salvaged. Bleeding and access-site complications remain prevalent in patients undergoing intra-arterial thrombolysis. This review discusses etiology, treatment approaches, outcomes, and complications when thrombolytic therapy is used for distal arm and hand ischemia.

[Angiographic diagnosis of acral circulatory disorders of the upper extremities]

Acral ischemic lesions rarely affect the upper extremities. While in the lower limbs atherosclerosis is responsible for the majority of lesions, vasculitis and autoimmune diseases play an important role in the pathogenesis of ischemic lesions of the upper limbs. A considerable number of acral circulatory disorders present with Raynaud's phenomenon and often without associated necrosis. Raynaud's phenomenon is mainly idiopathic but may also be secondary to underlying conditions, such as autoimmune diseases and vasculitis. Because of its high spatial resolution and the often discrete morphological findings digital subtraction angiography (DSA) is still an important diagnostic method in the radiological evaluation of acral circulatory disorders of the hand. Angiographic features of vasculitis are not strictly pathognomonic but certain morphologic DSA findings are very typical and may allow for a radiologic diagnosis. For instance, atherosclerosis results in irregular contours of vessel walls in DSA in contrast to autoimmune diseases and vasculitis, which are usually characterized by smooth vessel walls and optional vasospasm, the latter being especially typical for thromboangiitis obliterans and scleroderma. In thromboangiitis obliterans occlusions of the distal hand arteries, corkscrew collateral vessels and subsequent development of fine collateral networks are typical findings. Abrupt or filiform occlusions of distal finger arteries with sparse collateralization and symmetric affection of both hands are suggestive of scleroderma. Disseminated segmental ectasis and stenosis as well as microaneurysms (63% of all patients) are very common in patients with panarteriitis nodosa.

Hand gangrene following unsuccessful cannulation of the internal jugular vein: a case report and literature review

Hand gangrene following vascular cannula placement is uncommon and is usually the result of thrombotic occlusion of an artery. We describe a case of hand gangrene resulting in wrist disarticulation, following multiple unsuccessful attempts at internal jugular vein cannulation in a critically ill patient.

Fibrinolytic treatment of acute arterial occlusion distal to the wrist in two cases

Distal arterial occlusion in the hand threatens the viability of the digits and is difficult to treat. This study reports two cases in which fibrinolytic agents were used successfully to restore circulation in the digital arteries.

Thrombolytic therapy in the setting of arterial line-induced ischemia

PURPOSE

To evaluate the use of percutaneous transcatheter thrombolysis in the treatment of thrombosis due to radial artery cannulation.

METHODS AND RESULTS

Seven patients (4 women; age range 41-62 years) with symptomatic cannulation-induced thrombosis and failure to improve after systemic anticoagulation underwent 8 catheter-directed thrombolytic infusions at our institution over a 3-year period. Access was either antegrade through the brachial artery or retrograde through the femoral artery. Thrombolytic infusions with urokinase began 2 to 12 days (average 6) after removal of the radial artery catheter. The thrombolytic infusion was successful in 5 of 7 patients based on angiographic flow restoration with <20% residual thrombus and significant clinical improvement in the ischemia.

CONCLUSIONS

When systemic anticoagulation has failed, percutaneous catheter-directed thrombolytic infusion appears to be effective in the treatment of most patients with severe ischemic hand symptoms due to thrombosis after radial artery cannulation.

Endothelial dysfunction after arterial thrombosis is ameliorated by L-arginine in combination with thrombolysis

PURPOSE

To assess endothelial function after arterial thrombosis creation and after administration of a novel thrombolytic regimen in a new porcine model.

MATERIALS AND METHODS

Untreated arteries that had undergone thrombosis for 90 minutes were compared to arteries treated with tissue plasminogen activator (tPA, 4 mg) and a combination of tPA and L-arginine (L-arg; 600 mmol/L). External iliac artery luminal diameter was measured with use of duplex ultrasonography. Endothelial-dependent relaxation (EDR) and endothelial-independent relaxation (EIR) were measured with use of acetylcholine chloride (ACh) and sodium nitroprusside (NTP), respectively. Endothelial integrity was confirmed by scanning electron microscopy (SEM). Nitric oxide (NO) levels were determined with use of a chemiluminescent assay of its nitrite/nitrate metabolites (NO(x)).

RESULTS

After thrombosis, EDR was decreased (69% +/- 9.5; ACh = 15 micro g/min; n = 6). EDR remained unchanged after thrombolysis with tPA despite complete dissolution of thrombus (67% +/- 5.7; ACh = 15 micro g/min; n = 5). Thrombolysis with use of tPA coupled with L-arg resulted in an increase in EDR (95% +/- 4.9; ACh = 15 micro g/min; n = 5; P =.007). EIR was preserved in all groups, with uniform response to NTP. SEM analysis revealed intact endothelium in all groups. Local NO(x) levels were diminished after 90 minutes of thrombosis (49.3 micro mol/L vs 40.8 micro mol/L; P =.0002), but increased to 55.7 micro mol/L after thrombolysis with tPA and L-arg (P = NS).

CONCLUSIONS

Thrombus induces arterial dysfunction acutely without altering endothelial integrity. This dysfunction is ameliorated through regional administration of L-arg in combination with standard thrombolytic therapy, which increases local NO levels. This model allows the in-vivo study of thrombosis and alternative thrombolytic regimens. Regional enhancement of NO levels may prove to be an attractive adjunct in thrombolytic therapy.