Kidney Transplant Recipient With Cerebral Paradoxical Embolism Following Recurrent Idiopathic Deep Vein Thrombosis and Pulmonary Embolism: Case Report and Review of the Literature

Paradoxical embolism occurs when a thrombus crosses an intracardiac defect into the systemic circulation. Here, we present the case of a 35-yearold male kidney transplant recipient with a cerebral paradoxical embolism associated with a spontaneous venous thromboembolism. This patient had recurrent deep venous thrombosis and showering emboli to the lung and paradoxically to the brain through patent foramen ovale, and we treated him successfully. The role of bubble echocardiography was essential in diagnosis to avoid contrast-induced nephropathy. This is the first successfully managed case of a kidney transplant recipient with recurrent idiopathic deep vein thrombosis, pulmonary embolism, and cerebral paradoxical embolism. Bubble echocardiography was an excellent alternative to contrast angiography to avoid nephrotoxicity. Vitamin K antagonists are superior to direct oral anticoagulants, especially among nonadherent/noncompliant patients.

Myocardial Infarction Due to Paradoxical Thromboembolism Originating From Distal Lower Extremity Deep Vein Thrombosis (LEDVT)

Paradoxical embolism (PDE) originates in the venous system and ends up in the arterial circulation via cardiac or pulmonary shunts. Cases of PDE from venous thrombosis resulting in acute myocardial infarctions (MIs) are seldom reported in the literature. Diagnoses can often be missed if further workups are not pursued in patients without any underlying risk factors for coronary artery disease (CAD). Here, we report a case of a paradoxical embolus that crossed the patent foramen ovale (PFO), causing ST-elevation MI (STEMI) from an embolized venous thrombus originating in the left distal posterior tibial vein.

Challenging Cases in Cerebrovascular Disease

Disorders involving the vascular system of the brain are numerous and sundry. Atherosclerotic thromboembolism of large vessels and lacunar infarctions of small vessel disease are well known. Brain infarction due to cardioembolism is common as well, and even more so when diligently sought. Rupture of intracranial blood vessels results in subarachnoid and intraparenchymal hemorrhage. We present four cases of stroke of uncommon cause and remind clinicians to be open minded to the many possible causes of stroke, in particular because early recognition and treatment is often critical. Case 1 discusses a patient with inflammatory cerebral amyloid angiopathy. The presentation, ability to recur, and current treatment considerations are reviewed. Case 2 discusses microangiopathic thrombotic angiopathy. Diagnosis and treatment are considered. An association with interferon therapy and the evolving terminology of this and related conditions are discussed. Case 3 discusses intracranial hemorrhage secondary to acute promyelocytic leukemia. Patients with acute leukemias require aggressive management of their coagulopathy, thrombocytopenia, and the disease itself. Finally, Case 4 discusses ischemic stroke due to a paradoxical embolism in the setting of a patent foramen ovale (PFO). Both medical and surgical management of a PFO for stroke prevention are considered.

Radiopaque Fiducials Guiding Laparoscopic Resection of Liver Tumors

BACKGROUND

Minimal invasive laparoscopic resection of liver tumors is less traumatic compared with open surgical resection and may be a better option for many patients. However, localization of intrahepatic tumors remains a challenge. Availability of hybrid operating rooms, equipped for high performance radiologic imaging, allows for new methods of surgical navigation.

METHODS

Twelve patients planned for laparoscopic resection of liver tumors were included. Before resection started, tumors were marked with radiopaque fiducials. Four fiducials were positioned with ultrasound within 1 cm of the tumor. Tumor and fiducials were localized with contrast enhanced cone beam computed tomography. Fluoroscopy with an overlay of cone beam computed tomography markings was projected side-by-side on the same screen as the laparoscopic view to visualize tumor location. The fiducials were eventually removed. Laparoscopic ultrasound, the standard method of localizing a tumor, was also used. The benefits of the 2 visualization methods were estimated by the operator. Procedure times, radiation doses and resection margins were recorded.

RESULTS

Fluoroscopy with radiopaque fiducials provided valuable information, complementing the laparoscopic ultrasound, particularly during the early phase of resection. In the later phase, mobilization of the tumor-containing liver segment caused significant displacement of the fluoroscopic overlay. The technique evolved during course of the study, with decreasing procedure times and radiation doses. Radical resection was achieved for all patients.

CONCLUSIONS

Radiopaque fiducials and fluoroscopy can complement laparoscopic ultrasound for guiding resection of liver tumors. Combining radiologic and optical imaging in a hybrid operating suit may facilitate development of augmented reality techniques for surgical navigation.

Wide-ranging clinical spectrum of paradoxical embolism

The purpose of this review is to raise the index of suspicion for paradoxical embolism among generalists. The review is based solely on anecdotal reports compiled from EMBASE, MEDLINE, Googlescholar and Pubmed. Search terms were 'paradoxical embolism', 'pulmonary embolism' and 'pulmonary arteriovenous malformations'. What emerged was that right-to-left paradoxical embolism could occur with or without concurrent pulmonary embolism, and also with and without proof of the presence of an 'embolus-in-transit'. Potential sites of single or multiple systemic involvement included the central nervous system, the coronary circulation, renal arterial circulation, splenic circulation, the mesenteric circulation and the limbs. In many cases, the deep veins of the lower limbs were the source of thromboembolism. In other cases, thrombi originated from an atrial septal aneurysm, from a central venous line, from a haemodialysis-related arterio-venous shunt, from a popliteal vein aneurysm, internal jugular vein, superior vena cava, from a pulmonary arteriovenous malformation, from tricuspid valve endocarditis (with and without pulmonary embolism) and from the right atrium, respectively. Stroke was by far the commonest systemic manifestation of paradoxical embolism. Some strokes were attributable to pulmonary arteriovenous malformations with or without coexistence of intracardiac shunts. Clinicians should have a high index of suspicion for paradoxical embolism because of its time-sensitive dimension when it occurs in the context of involvement of the intracranial circulation, coronary circulation, mesenteric circulation, and peripheral limb circulation.

Cerebral Air Embolism: A Clinical, Radiologic and Histopathologic Correlation

Cerebral air embolism is a recognized life-threatening complication, sometimes iatrogenic. Its timely diagnosis is essential because it can result in neurologic deficits or death. We report a case of a 58-year-old man who died from cerebral air embolism diagnosed by nonenhanced computed tomography scan of the head after a cardiac bypass surgery with Biventricular Assist Device and multiple vascular line placements. Autopsy revealed extensive subcutaneous emphysema, intravascular and perivascular air bubbles in the central nervous system and associated cerebral and cerebellar hemorrhagic infarction. The autopsy was helpful in documenting the extent of the air embolism and its appearance in soft tissue and central nervous system.

Unusual Cerebral Emboli

The heart and the carotid arteries are the most common sites of origin of embolic disease to the brain. Clots arising from these locations are the most common types of brain emboli. Less common cerebral emboli include air, fat, calcium, infected vegetations, and tumor cells as well as emboli originating in the venous system. Although infarcts can be the final result of any type of embolism, described herein are the ancillary and sometimes unique imaging features of less common types of cerebral emboli that may allow for a specific diagnosis to be made or at least suspected in many patients.

The imaging features of neurologic complications of left atrial myxomas

BACKGROUND

Neurologic complications may be the first symptoms of atrial myxomas. Understanding the imaging features of neurologic complications of atrial myxomas can be helpful for the prompt diagnosis.

OBJECTIVE

To identify neuroimaging features for patients with neurologic complications attributed to atrial myxoma.

METHODS

We retrospectively reviewed the medical records of 103 patients with pathologically confirmed atrial myxoma at Xiangya Hospital from January 2009 to January 2014. The neuroimaging data for patients with neurologic complications were analyzed.

RESULTS

Eight patients with atrial myxomas (7.77%) presented with neurologic manifestations, which constituted the initial symptoms for seven patients (87.5%). Neuroimaging showed five cases of cerebral infarctions and three cases of aneurysms. The main patterns of the infarctions were multiplicity (100.0%) and involvement of the middle cerebral artery territory (80.0%). The aneurysms were fusiform in shape, multiple in number (100.0%) and located in the distal middle cerebral artery (100.0%). More specifically, high-density in the vicinity of the aneurysms was observed on CT for two patients (66.7%), and homogenous enhancement surrounding the aneurysms was detected in the enhanced imaging for two patients (66.7%).

CONCLUSION

Neurologic complications secondary to atrial myxoma consist of cerebral infarctions and aneurysms, which show certain characteristic features in neuroimaging. Echocardiography should be performed in patients with multiple cerebral infarctions, and multiple aneurysms, especially when aneurysms are distal in location. More importantly, greater attention should be paid to the imaging changes surrounding the aneurysms when myxomatous aneurysms are suspected and these are going to be the relevant features in our article.