From the Guidelines
Percutaneous Nephrolithotomy (PCNL) is a minimally invasive surgical procedure used to remove large kidney stones, and the step-by-step process involves accessing the kidney through a small incision in the back, dilating the tract, and using a nephroscope to visualize and fragment the stones. The procedure begins with the patient under general anesthesia, positioned prone on the operating table. First, the surgeon inserts a ureteral catheter through the urethra into the affected kidney to inject contrast dye, which helps visualize the collecting system under fluoroscopy 1. Next, the surgeon makes a small incision (about 1 cm) in the patient's back and creates a nephrostomy tract by inserting a needle into the kidney under fluoroscopic guidance. A guidewire is then passed through the needle, and the tract is dilated using sequential dilators or a balloon dilator to create a working channel approximately 8-10 mm in diameter. Through this channel, a nephroscope is inserted to visualize the stones directly. The surgeon fragments the stones using ultrasonic, pneumatic, or laser lithotripters and removes the fragments with grasping forceps or suction 1. After stone clearance is confirmed with fluoroscopy or flexible nephroscopy, a nephrostomy tube is usually placed to ensure drainage and allow access if further procedures are needed. The tube is typically removed after 1-2 days if no complications occur and X-rays confirm complete stone removal. Some key points to consider during the procedure include:
- Using normal saline irrigation to prevent electrolyte abnormalities 1
- Flexible nephroscopy as a routine part of standard PCNL to access stones that cannot be reached with a rigid nephroscope 1
- The potential risks and complications of PCNL, such as bleeding, infection, and bowel injury 1 Patients generally stay in the hospital for 2-3 days and are advised to avoid strenuous activity for 2-4 weeks. Antibiotics are commonly prescribed for 5-7 days post-procedure to prevent infection. PCNL is preferred for stones larger than 2 cm, complex stones, or when other less invasive approaches have failed, as it allows direct access to the collecting system and higher stone clearance rates compared to other techniques. It is essential to inform patients about the potential risks and benefits of PCNL and to discuss alternative treatment options, such as ureteroscopy, to determine the best course of treatment for their specific condition.
From the Research
PCNL Procedure Overview
The Percutaneous Nephrolithotomy (PCNL) procedure is a well-accepted technique for removing large or complex renal calculi 2. The procedure involves several steps, which are outlined below:
- Patient positioning: The patient can be positioned in either the supine or prone position 3, 4.
- Access to the kidney: The access to the kidney is made with the help of either fluoroscopy or ultrasound 5. Recently, endoscopy-guided puncture has also been described 5.
- Tract dilation: The percutaneous tract is dilated over a wire 4.
- Nephroscope insertion: A rigid mini-PCNL nephroscope is used to evaluate the collecting system 4.
- Stone fragmentation: Options for stone fragmentation include a lithotripter with ultrasonic and ballistic energy, or laser lithotripsy using holmium or thulium laser fibers 4.
- Stone removal: The stone is removed through the nephroscope 4.
- Tract sealing: The tract is sealed using Surgiflo hemostatic matrix with thrombin 4.
Nephrostomy Tube Selection
The selection of a nephrostomy tube (NT) is an important aspect of the PCNL procedure 2. The choice of NT depends on several factors, including the size and complexity of the stone, the patient's anatomy, and the surgeon's preference. The most commonly used NTs are:
Complications and Considerations
The PCNL procedure is not without complications 5. Possible complications include:
- Injury to the pleura and other visceral organs
- Bleeding
- Infection
- Incomplete stone clearance
- Hydrothorax
- Arteriovenous fistula
- Ureteral perforation
To minimize these complications, it is essential to carefully select the nephrostomy tube and to use proper technique during the procedure 2, 5. Additionally, the surgeon should be skilled and experienced in performing the PCNL procedure 5.