Splenic Arteriovenous Fistula: An Unusual Cause of Portal Hypertension Primarily Diagnosed by Color Duplex Sonography

Splenic arteriovenous fistulas (avfs) are rare lesions. herein, we report a 40-year-old man with portal hypertension secondary to splenic avf, which was primarily diagnosed by color duplex sonography. sonography revealed a non-pulsatile, cyst-like mass at the splenic hilum with an unusual comma-shaped extension. in color duplex sonography, complete color fill-in of the lesion with the characteristic reversed red and blue color flow (yin-yang pattern) was observed. duplex doppler interrogation of the avf revealed high velocity low-impedance arterial flow and moderately pulsatile venous flow within the lateral and medial part of the lesion, respectively. the comma-like extension demonstrated a low-resistance arterial waveform with very high peak systolic velocity. based on these findings, a diagnosis of splenic avf was made which was confirmed at surgery. special emphasis was made on onographicfindings enabling the correct diagnosis.