Miniaturized Percutaneous Nephrolithotomy (Mini-Perc)


Miniaturized Percutaneous Nephrolithotomy (PCNL) is a procedure used to remove large kidney stones. Unlike standard percutaneous nephrolithotomy, miniaturized PCNL (also known as mini-perc) uses smaller instruments, which reduces the risk of bleeding and prevents the risk of kidney damage without compromising procedure efficacy. The incision made during a mini-perc is much smaller and supports a faster recovery process.

At the UCI Kidney Stone Center, we are pleased to offer the latest in laser technology. Specifically, the Thulium laser allows us to perform more efficient lithotripsy and turns even the largest and hardest stones into fine dust. The combination of Thulium laser technology and the mini-perc has revolutionized the manner in which we treat patients with large kidney stones.

Benefits of a Mini-Perc

This advanced procedure allows for large or complex stones to be treated in a minimally invasive manner. Often this procedure can be performed on an outpatient bases or require just one night stay for observation., Patients are able to return to work quicker and resume daily activities.

The procedure should only be performed by specially trained surgeons to ensure exceptional results.


How to Prepare for the Procedure

Patients will be instructed to avoid eating or drinking for six hours prior to treatment. They may take small sips of water if they need to continue regular medications. However, they will need to pause blood thinning agents, such as warfarin and plavix, seven to 10 days prior to the procedure.

Patients will need to submit a urine sample for culture to ensure there is no bacteria in the urine before treatment can begin. Surgeons may also need the patient to undergo a kidney function study, full blood count, and a clotting profile to provide more detailed information about the patient’s condition.

Potential Risks and Side Effects

When performed by a specially trained urologist, a mini-perc has low risk of complications. Rare side effects may include infection, excessive bleeding, and injury to adjacent organs, such as the spleen, liver, lung, bowel, and diaphragm.

What to Expect During the Procedure

The patient will be placed under general anesthesia and lay on their front for the duration of the procedure, which can take two to three hours.

The surgeon will use x-ray imaging or ultrasound to guide insertion of the hollow tube into the kidney. The tube will provide access to the kidney drainage system, allowing the surgeon to insert telescopes, laser fibers, and stone grasping devices. A ureteral stent, which is a hollow plastic tube, is often placed within the body at the end of the procedure. This temporary internal drainage stent allows urine to drain freely from the kidney to the bladder and it is typically removed in the office one week after surgery.

The Recovery Process

Once the procedure is complete, patients will undergo additional medical imaging to ensure complete kidney stone removal. Patients may be discharged the same day as surgery or are kept for overnight observation to ensure full recovery.

A foley catheter is often placed at the time of the procedure and this will be removed once the patient is ready to be discharged. Patients may have blood-stained urine for up to one week after discharge from the hospital. As long as the blood doesn’t get heavier, patients shouldn’t be alarmed.

Hospital staff will instruct patients to avoid strenuous activity after the procedure and take oral antibiotics for five days to prevent infection. Patients should contact their physician if they experience fevers, chills, or heavy bleeding in the urine.