Cerebral hyperperfusion and other consequences of hemodialysis central vein catheters

Introduction

Central venous pathology is commonly found in patients with end-stage renal disease (ESRD) most commonly who have had instrumentation of the central veins, protracted central venous catheter use, or have an intracardiac device with transvenous leads. Perturbations to the endothelial lining of the central veins can result in intimal hyperplasia, and progressive central venous stenosis. A key contributor to progressive and symptomatic central venous stenosis is turbulent blood flow, commonly resulting from an ipsilateral arteriovenous (AV) access.

Common sequelae of symptomatic central venous stenosis

When an AV access is present, common sequelae of symptomatic central venous stenosis or occlusion are ipsilateral upper extremity, face and breast edema, the development of collateral veins to aid drainage of the affected limb, poor dialysis clearance, and reduced AV access patency. The diagnosis of symptomatic central venous stenosis or occlusion in the setting of an ipsilateral AV access is generally made by obtaining an angiogram of the AV access, draining and central veins. Commonly there is clinically significant stenosis present at the level of the subclavian of brachial-cephalic veins, and often reflux is observed to ipsilateral collateral veins or the internal or external jugular veins. First-line treatment is percutaneous angioplasty (PTA) with or without stent placement.

Uncommon sequelae of central venous stenosis

While patients with symptomatic central venous stenosis often present with characteristic unilateral upper extremity venous hypertension and are routinely treated with PTA, recent case reports document the development of intracranial pathology resulting from central venous stenosis, including venous congestive encephalopathy, peri-mesencephalic subarachnoid hemorrhage, myoclonic epilepsy and cerebral infarction (1–2–3–4). These intracranial findings were associated with brachial-cephalic and superior vena cava stenosis or occlusion and resultant internal jugular reflux.

The ESRD patients described present with non-specific neurologic signs and symptoms in conjunction with a functional AV access. Symptoms range from altered mental status (1), headache, agitation, and drowsiness (4). Given the non-specific symptoms, a delay in diagnosis can follow, and subsequent neurologic deterioration. Prasad et al (1) describes a 47-year-old male with a left upper arm arteriovenous graft (AVG) who presented with altered mental status and was diagnosed with a left subdural hematoma. The patient then developed nystagmus, diminished gag reflexes and right hypertonia. He underwent a brain magnetic resonance imaging (MRI) scan and was diagnosed with acute left cerebral infarction, followed by a cerebral angiogram revealing abnormal venous drainage through the right dural sinuses into the right internal jugular vein. Finally, the patient underwent an AVG angiogram where it was noted that he had left brachial-cephalic vein occlusion with reflux to the left internal jugular vein. The patient underwent PTA and stent placement to the brachial-cephalic vein, and subsequently his strength and hypertonia improved.

Samaniego et al (4) describe a 50-year-old male with ESRD who presented with two weeks of headaches and altered mental status. The patient had had a right upper arm AVG placed two weeks prior to presentation and a week later, developed right facial and upper extremity edema. On presentation, the patient was noted to have a right occipital stroke on MRI, and right brachial-cephalic vein occlusion on aortic arch angiography, with retrograde flow to the internal jugular vein. The AVG was ligated, and the patient's mental status is reported to have cleared within three days, and he was back to his baseline neurologic status within one week.

Chronic venous hypertension is thought to be the key contributor to internal jugular valve incompetence, resulting in alterations in intracranial circulation. Patients may develop collateral blood flow into the superficial or deep veins before venous reflux into the intracranial veins occurs, depending on the time to development, and may therefore avoid developing intracranial pathology.

Conclusion

While central venous stenosis is a common consequence of protracted central venous catheter use, intracardiac device transvenous leads, and central venous instrumentation, the majority of patients who develop symptomatic central venous stenosis present with unilateral venous hypertension. However, some patients may develop intracranial hypertension and present with non-specific signs and symptoms. It is important to consider the presence of an abnormal intra-cranial venous circulation in patients with an AV access who present with neurologic symptoms.