Staghorn kidney stones are large, fast-growing stones with “branches.” They can block the urinary tract, causing inflammation, severe pain, and serious complications.

Struvite, or magnesium ammonium phosphate, is the major component of most staghorn kidney stones. Due to their size, doctors typically perform surgery to remove the stones.

They account for about 10–15% of all cases of kidney stones in developing countries. In developed countries, the rate is lower due to early identification and prevention strategies.

This article reviews staghorn kidney stones, who is most likely to develop them, their symptoms, causes, and more.

Staghorn kidney stones are a type of large urinary calculus, or stone, that takes up a large portion of the urinary collecting area in the kidney. They often present in only one kidney, but in up to 15% of cases, they form in both.

They often form due to recurrent urinary tract infections (UTIs).

Are they serious?

Staghorn kidney stones can cause diminished kidney function and result in serious symptoms, including urosepsis. This is a type of sepsis, a life threatening reaction, due to infections of the urinary tract. Staghorn kidney stones can also cause pain and discomfort.

People with these stones have a high morbidity and mortality rate.

They will typically require surgery to remove the entire stone to help prevent infections and recurrence.

Learn more about kidney stones.

Staghorn kidney stones are large and disruptive. As a result, nearly everyone who develops them will experience symptoms, such as:

Learn more about the symptoms of kidney stones.

There are several potential causes and risk factors of staghorn kidney stones. They develop due to recurrent UTIs.

Females are twice as likely to get staghorn kidney stones than males. They are also more common in people with one or more of the following conditions:

  • congenital urinary tract malformations
  • distal renal tubular acidosis
  • medullary sponge kidney
  • diabetes
  • renal tract anomalies
  • neurogenic bladder, where the nerves or the brain cannot communicate effectively with the bladder muscles
  • ileal ureteral diversion, where, following a surgical procedure, a segment of the intestine directs urine through a stoma
  • having an indwelling Foley catheter

The American Urological Association also list the following risk factors for kidney stones:

Evidence also suggests that they are more likely to occur in people living in developing countries. People in more developed countries often have access to earlier preventive care, which may lower the incident rate.

Can diet cause staghorn kidney stones?

Unlike other, more common types of stones, diet does not directly influence the formation of staghorn kidney stones.

Older evidence suggests that eating a reduced phosphate and calcium diet accompanying estrogen supplements and iron gel may help reduce the recurrence of staghorn stones.

For example, a person prone to uric acid stones can avoid animal proteins to help prevent their formation.

To diagnose staghorn kidney stones, a doctor will often review the presenting symptoms with the person. They will likely perform a physical exam and review the person’s medical and family history.

To make a formal diagnosis, they may use one or more of the following imaging tests:

The gold standard treatment for staghorn kidney stones is percutaneous nephrolithotomy (PCNL), which doctors also use for other stones larger than 2 centimeters.

PCNL is a type of surgery to remove kidney stones. During the procedure, a surgeon creates an opening from the skin to the back of the kidney.

They then insert a tube and use it to insert instruments that can remove the stone.

PCNL is not always successful. The success of the surgery varies depending on the complexity of the stones, the surgeons, and other factors. People may also need more than one surgery to remove the stones.

Previously, doctors preferred open surgery to remove the stone and return kidney function. Open surgery involves making a much larger opening, leading to longer recovery times. However, some studies show it has a high success rate compared with PCNL and other less invasive options.

Another removal technique is extracorporeal shockwave lithotripsy, which uses shock waves or a laser to break up the stones.

Recovery from treatment

Recovery will vary according to the treatment. A person generally recovers faster with fewer complications when a doctor removes the stone with PCNL.

Following the procedure, a person should follow all recommendations from their doctor and medical team to help prevent complications and reduce the risk of recurrence.

A person can take steps to help reduce the likelihood of staghorn kidney stone recurrence. They include:

  • dietary changes
  • taking oral urease inhibitors
  • taking antibiotics
  • staying hydrated

A doctor can prescribe medications and explain other steps a person can take to prevent a recurrence.

Learn about 10 ways to prevent kidney stones here.

Staghorn kidney stones have a high mortality rate. However, surgical removal is often successful.

If surgeons are unable to remove all of the kidney stones, a person should be able to pass the remaining stone fragments in their urine over the following weeks.

Without treatment, someone will likely experience recurrent UTIs and loss of kidney function.

A person should contact their doctor if they develop any symptoms indicating an issue with their kidneys. This includes lower flank pain and blood in the urine.

A doctor can diagnose the issue and recommend the right treatment.

Staghorn kidney stones are large deposits that block urinary output in the body. They often cause symptoms such as pain in the lower side and blood in the urine. Staghorn kidney stones can also cause urosepsis, which refers to sepsis due to infections of the urinary tract.

Females are more likely than males to develop staghorn kidney stones. People with recurrent UTIs are also more susceptible.

Treatment typically involves surgically removing the stone. However, a person has a higher risk of recurrence or infection if surgeons cannot remove the entire stone.