Doppler ultrasound diagnosis of anterior nutcracker syndrome presenting with isolated urinary abnormalities.

Nutcracker syndrome is a vascular compression disorder caused by entrapment of the left renal vein between the abdominal aorta and the superior mesenteric artery, leading to renal venous hypertension and a spectrum of urinary and pelvic symptoms. We report the case of a 19-year-old male referred for incidental microscopic hematuria and mild proteinuria detected during routine laboratory screening. Ultrasound demonstrated marked dilation of the left renal vein proximal to the aortomesenteric crossing, with focal narrowing at the compression site. Pulse-wave Doppler evaluation revealed significant flow acceleration within the stenotic segment, with a peak velocity of 178 cm/s and an estimated trans-stenotic pressure gradient of 12.8 mmHg. These combined morphological and hemodynamic findings strongly supported the diagnosis of anterior Nutcracker syndrome without the immediate need for additional imaging studies. The patient was managed conservatively because urinary abnormalities were mild and no pain, gross hematuria, or pelvic symptoms were present. This case highlights the pivotal role of Doppler ultrasound as a first-line, noninvasive imaging modality capable of providing both anatomical and functional assessment.