Each kidney typically has one vein that carries blood filtered by the kidney into the circulatory system. These are called the renal veins. Usually there’s one on the right and one on the left. However, there can be variations. In nutcracker syndrome, symptoms are most often caused when the left renal vein coming from the left kidney becomes compressed and blood can’t flow normally through it. Instead, blood flows backwards into other veins and causes them to swell.
Causes of Nutcracker Syndrome
The specific causes of nutcracker syndrome can vary. Some people are born with certain blood vessel variations that can lead to symptoms of nutcracker syndrome. Others can develop the syndrome due to changes within the abdomen. Symptoms are more common in females in their 20s and 30s, but it can affect anyone of any age.
Some conditions that may increase the chance of developing nutcracker syndrome include:
Tumors in the tissue lining your abdominal wall
A severe lower spine curve
Nephroptosis, when your kidney drops into your pelvis when you stand up
An aneurysm in your abdominal aorta
Rapid changes in height or weight
Low body mass index
Enlarged lymph nodes in your abdomen
Symptoms of Nutcracker Syndrome
Blood in your urine
Pain in your side or abdomen
Protein in your urine, which can be determined by a doctor
Pain during intercourse
Enlarged veins in testicles
Lightheadedness while standing, but not while sitting
Diagnosis of Nutcracker Syndrome
First, your doctor will perform a physical exam.
Next, they’ll take a medical history and ask about your symptoms to help them narrow down a possible diagnosis.
If they suspect nutcracker syndrome, your doctor will take urine samples to look for blood, protein, and bacteria.
Blood samples can be used to check blood cell counts and kidney function.
This will help them narrow down your diagnosis even further.
Next, your doctor may recommend a Doppler ultrasound of your kidney area to see if you have abnormal blood flow through your veins and arteries.
Depending on your anatomy and symptoms, your doctor also may recommend a CT scan or MRI to look more closely at your kidney, blood vessels, and other organs to see exactly where and why the vein is compressed.
They might also recommend a kidney biopsy to help rule out other conditions that can cause similar symptoms.
Treatment of Nutcracker Syndrome
A stent is a small mesh tube that holds the compressed vein open and allows blood to flow normally.
This procedure has been used for nearly 20 years for the treatment of this condition.
Your doctor can insert it by cutting a small slit in your leg and using a catheter to move the stent into the proper position inside your vein.
However, like any procedure, there are risks.
About 7 percent of people experience movement of the stent. This can lead to complications such as:
Blood vessel injury
Severe tears in the blood vessel wall
Stent placement requires an overnight hospital stay and full recovery can take several months. You and your doctor should discuss the risks and benefits of this procedure, as well as other treatment options.
Blood vessel surgery
If you have more severe symptoms, blood vessel surgery may be a better option for you.
Your doctor might recommend a variety of surgical procedures to relieve pressure on the vein.
Options can include moving the vein and reattaching it, so it’s no longer in an area where it would be compressed.
Another option is bypass surgery, in which a vein taken from elsewhere in your body is attached to replace the compressed vein.
Recovery from surgery depends on the type of surgery and your overall health. It generally takes several months.