Spontaneous peripheral arterial microembolization

The usefulness of Duplex Doppler ultrasound in the angiological and dermatological diagnosis of patients with blue toe syndrome

Introduction

Peripheral microembolism is one of the most frequent causes of acute limb ischemia. In order to effectively prevent relapses it is essential to localize and eliminate the source of embolism.

Aim

To evaluate the role of Duplex Doppler ultrasound examination in identifying the causes of blue toe syndrome (BTS).

Material and methods

The group of 165 patients with clinical symptoms of BTS on their upper limbs (n = 16) and lower limbs (n = 149) was investigated. They all underwent Duplex Doppler ultrasound of the major arteries of the extremities, where ischemic changes occurred.

Results

Morphological and functional changes which might be potential sources of microembolism were identified in 146 patients. These changes included significant short-length stenoses or unstable atherosclerotic plaque (n = 73), true aneurysms (n = 42) and pseudoaneurysms (n = 17). In 11 cases, pathology of vascular prostheses in the form of anastomotic aneurysms, infection and residual thrombi after fibrinolysis was detected. In all cases, Duplex diagnosis was confirmed by other imaging and intraoperative tests.

Conclusions

Duplex Doppler ultrasound of the arteries in the affected limb with a full length view should be the first-line examination in diagnosing patients with BTS. In the absence of hemodynamic blood flow disturbances in the major arteries in patients with symptoms of BTS, it is advisable to start haematological tests to identify/exclude congenital or acquired thrombophilia.

[Actually a routine matter: ischemia after catheterization of the radial artery]

A 76-year-old patient developed necrosis of the index finger after placement of a radial artery catheter. This article discusses the risks associated with invasive blood pressure monitoring and treatment options in cases of critical ischemia. The authors conclude that there is no consensus concerning optimal treatment and that a discussion on options for preoperative risk assessment and quickest possible recognition of such complications is worthwhile. Despite the risk of ischemia invasive blood pressure monitoring is an indispensable procedure.

Peripheral Digit Ischemic Syndrome Can Be a Manifestation of Postoperative Thrombotic Thrombocytopenic Purpura

In addition to common dysfunction of the brain and kidney, thrombotic thrombocytopenic purpura (TTP) may present with atypical clinical features due to the involvement of other organs such as the lung, pancreas, heart, eye, and skin. We have also observed the unusual presentation of peripheral digit ischemic syndrome (PDIS) in some patients with postoperative TTP. To clarify this relationship between TTP and PDIS, the hematologic data from the medical records of patients with known diagnoses of thrombotic microangiopathy (TM) were examined in a single institution. A total of 94 patients were diagnosed with TM. Among these patients, PDIS developed in six patients and in all these patients PDIS occurred with postoperative TTP. Four patients also had acute respiratory distress syndrome (ARDS). Because of delayed diagnosis of TTP, only two patients survived and four died. One patient responded to plasma exchange and survived, and another patient recovered from postoperative TTP without plasma exchange. However, both patients required the amputation of multiple digits. In conclusion, PDIS is another atypical manifestation of TTP and has occurred exclusively in patients with postoperative TTP in this series. Once PDIS developed, the prognosis was poor and amputation of digits was needed in surviving patients. Early recognition of this atypical manifestation of TTP is essential for a favorable outcome.