Nutcracker syndrome: Diagnosis with Doppler US

PURPOSE: To assess diagnosis of the nutcracker (renal vein entrapment) syndrome with Doppler ultrasonography (US). MATERIALS AND METHODS: Doppler US findings in 16 patients with the nutcracker syndrome and in 18 healthy control subjects were compared. The anteroposterior (AP) diameter and peak velocity (PV) were measured at the hilar portion of the left renal vein (LRV) and at the LRV between the aorta and the superior mesenteric artery. RESULTS: The mean AP diameters of the LRV were 10.0 mm +/- 2.0 (standard deviation) and 1.9 mm +/- 1.0 (ratio, 5.0 +/- 2.3) in the patient group and 7.2 mm +/- 1.8 and 2.3 mm +/- 0.6 (ratio, 3.3 +/- 1.1) in the control group. The PVs at the two locations were 14.2 cm/sec +/- 2.5 and 110.7 cm/sec +/- 35.8 (ratio, 7.9 +/- 2.7) in the patient group and 18.6 cm/sec +/- 3.7 and 50.9 cm/sec +/- 27.9 (ratio, 2.8 +/- 1.5) in the control group. Differences in AF diameter and PV were statistically significant between the two groups (P < .01). CONCLUSION: Doppler US of the LRV with measurement of the AP diameter and PV may be useful in diagnosing the nutcracker syndrome.