From the Guidelines
This patient's presentation suggests a potential complication of Osler-Weber-Rendu syndrome (also called hereditary hemorrhagic telangiectasia or HHT) with a history of popliteal aneurysm, and immediate vascular surgery consultation is recommended along with urgent duplex ultrasound or CT angiography of the affected leg. The leg pain could indicate aneurysm expansion, rupture, thrombosis, or distal embolization. While awaiting evaluation, the patient should rest, avoid strenuous activity, and receive appropriate pain management with acetaminophen or NSAIDs if not contraindicated. Given the HHT diagnosis, careful consideration of anticoagulation is needed if thrombosis is suspected, as these patients have increased bleeding risk from vascular malformations 1.
Key Considerations
- The connection between HHT and aneurysms relates to the underlying genetic mutations (typically in ENG, ACVRL1, or SMAD4 genes) that affect blood vessel wall integrity, disrupting TGF-β signaling pathways and leading to abnormal vascular development and potential weakening of arterial walls 1.
- For long-term management, patients with HHT and aneurysms require regular vascular surveillance, genetic counseling, and screening of first-degree relatives.
- Blood pressure control is also essential to reduce stress on vessel walls.
- The management of HHT has evolved, with systemic therapies now recommended for certain manifestations, such as epistaxis, where oral tranexamic acid has shown efficacy in reducing its duration and intensity 1.
Diagnostic Approach
- Urgent duplex ultrasound or CT angiography of the affected leg is necessary to assess the aneurysm and potential complications such as thrombosis or distal embolization.
- A complete blood count, chemistries (including blood glucose and renal function tests), electrocardiogram, and ABI should be part of the initial evaluation to assess the patient's overall vascular health and risk factors for complications 1.
Treatment
- Immediate vascular surgery consultation is crucial for patients with suspected complications of popliteal aneurysms, especially in the context of HHT, given the high risk of thromboembolic events and the potential for significant morbidity and mortality 1.
- Pain management should be tailored to the patient's needs, considering the potential for increased bleeding risk with certain medications.
- Long-term management should include regular follow-up with a vascular specialist, genetic counseling, and screening for other vascular manifestations of HHT.
From the Research
Diagnosis of Hereditary Hemorrhagic Telangiectasia (Osler-Weber-Rendu Syndrome)
The diagnosis of Hereditary Hemorrhagic Telangiectasia (Osler-Weber-Rendu Syndrome) is based on the Curacao criteria, which include:
- Epistaxis
- Teleangiectasia
- Viseral lesions (e.g. arteriovenous malformations (AVMs) in organs such as the lungs, liver, and brain)
- Family history
Clinical Presentation
Patients with Hereditary Hemorrhagic Telangiectasia (Osler-Weber-Rendu Syndrome) may present with various symptoms, including:
- Epistaxis (nosebleeds) 2
- Teleangiectasia (visible on the skin or mucous membranes) 3, 2
- Visceral lesions (e.g. AVMs in organs such as the lungs, liver, and brain) 3, 4
- Leg pain (in cases with vascular abnormalities, such as aneurysms)
Imaging Modalities
Modern imaging modalities, such as computed tomography (CT) or magnetic resonance imaging (MRI), are important for depicting AVMs and other vascular abnormalities in patients with Hereditary Hemorrhagic Telangiectasia (Osler-Weber-Rendu Syndrome) 3, 4.
- CT imaging can depict pulmonary AVMs even without the use of a contrast agent
- MRI can depict AVMs in the central nervous system (CNS) and other organs, usually requiring administration of contrast agents
Treatment
Treatment of Hereditary Hemorrhagic Telangiectasia (Osler-Weber-Rendu Syndrome) involves a multidisciplinary approach, including: