Nutcracker phenomenon

Last revised by Henry Knipe ◉ on 27 Oct 2020

Citation, DOI, disclosures and article data

Citation:

Weerakkody Y, Knipe H, Saber M, et al. Nutcracker phenomenon. Reference article, Radiopaedia.org (Accessed on 11 Mar 2025) https://doi.org/10.53347/rID-70879

DOI:

https://doi.org/10.53347/rID-70879

Permalink:

https://radiopaedia.org/articles/70879

rID:

70879

Article created:

7 Sep 2019, Yuranga Weerakkody ◉

Disclosures:

At the time the article was created Yuranga Weerakkody had no recorded disclosures.

View Yuranga Weerakkody's current disclosures

Last revised:

27 Oct 2020, Henry Knipe ◉

Disclosures:

At the time the article was last revised Henry Knipe had no recorded disclosures.

View Henry Knipe's current disclosures

Revisions:

8 times, by 6 contributors - see full revision history and disclosures

Systems:

Vascular, Gastrointestinal, Urogenital

Synonyms:

Left renal vein entrapment
Nutcracker phenomenon (NCP)
Nutcracker anatomy

The nutcracker phenomenon, also known as nutcracker anatomy or left renal vein entrapment, refers to the anatomic or pathophysiologic entity wherein the superior mesenteric artery compresses and impedes outflow of the left renal vein into the inferior vena cava. It can be a common incidental finding on routine CT imaging and many patients can be asymptomatic². If associated with relevant symptoms, it is then known as the nutcracker syndrome.

Radiographic features

Cross-sectional imaging demonstrates narrowing of the mesoaortic interval or angle as well as dilatation of the lateral (hilar) aspect of the left renal vein. There may also be dilatation of the gonadal vein with reflux of contrast material.