Capillary anastomosis in vena caval thrombosis

Area of Science:

• Nuclear medicine
• Vascular imaging
• Oncology

Background:

• A 29-year-old woman with recurrent diffuse histiocytic lymphoma underwent chemotherapy.
• Bilateral brachial venous catheters were placed for treatment delivery.
• Chemotherapy resulted in thrombotic occlusion of the superior vena cava.

Observation:

• A lung scan using Technetium-99m macroaggregated albumin (Tc-99m MAA) showed extensive collateral vessels in the upper thorax.
• The lung scan also demonstrated trapping of particles in the right upper abdomen.
• A simultaneous liver scan with Tc-99m sulfur colloid showed a normal liver without other abnormal tracer deposition.

Findings:

• The Tc-99m MAA accumulation in the anterior abdominal wall was identified.
• This accumulation was secondary to capillary anastomosis between the superior and inferior epigastric veins.
• The findings indicate a venous pathway bypassing the occluded superior vena cava.

Implications:

• This case highlights an unusual complication of venous catheterization in lymphoma patients.
• Nuclear medicine imaging successfully identified collateral venous pathways.
• Understanding these venous anomalies is crucial for managing complications and guiding treatment in oncology patients.