What Is Percutaneous Nephrolithotomy?
Percutaneous nephrolithotomy is a surgical procedure wherein kidney stones are removed from the body. It is used to remove large stones which cannot pass on their own in the urine and hinder the urine flow. The term percutaneous means through the skin, whereas the term nephrolithotomy indicates the breakdown of stones into small fragments. The doctor creates a passage through the skin to reach the kidneys in this procedure. Finally, the surgeon uses some surgical instruments to locate and remove the stones. Percutaneous nephrolithotomy is mainly used when home remedies and other conservative methods have failed to produce the desired results.
What Are Kidney Stones?
Nephrolithiasis or kidney stones form because of the collection of salts, crystals, and minerals in the kidneys. These substances form a whole mass of stones in the kidneys. As a result, these substances cluster up and result in the formation of stones. On the other hand, the substance called citrate, which does not allow these stones to form, will be present in less amount in the urine, so there is no mechanism left to stop the formation of these stones due to the accumulation of the crystals.
Why Do Kidney Stones Form?
Some of these stone-forming factors are described below:
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The pH (Potential of Hydrogen) of Urine: The pH level of the urine has a significant impact on the formation of kidney stones. It is essential to maintain the optimum or neutral pH of the urine (pH - 7). You might encounter the problem of kidney stones if the pH level goes up or down. The urine goes acidic if the pH level goes down and basic if it goes up.
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Drinking Less Water: It is important that the patient drinks a sufficient quantity of water every day to stay hydrated. If enough liquids are not consumed, it will lead to a reduction in the concentration of urine. Consequently, the crystals that form the stone will start gathering together and sticking to each other, resulting in stone formation.
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Nutrition and Diet: A patient’s diet greatly impacts kidney stones because foods like chocolates, beets, and rhubarb contain a lot of oxalates and can increase the risk of stones. Similarly, consuming salt and foods like chicken and meat can be risky.
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Urinary Tract Infections - If the urinary tract infection is left untreated for a long, the urine flow becomes restricted. As a result, the minerals and salts in the urine cluster up and form stones.
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Inflammatory Bowel Disease - If the patient suffers from bowel diseases, large amounts of oxalates (stone-forming substances) are released.
Why Is Percutaneous Nephrolithotomy Done?
Percutaneous nephrolithotomy is mainly done when the patient experiences difficulty in passing urine due to large stones. It is done under the following situations:
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Large kidney stones are present, and they block a branch of the collecting system of kidney tubules. These stones are known as staghorn stones.
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Kidney stones are more than two centimeters in diameter.
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Large stones are present in the tubes that connect the bladder and the kidneys (ureters).
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Conservative treatment options have failed to remove the stones.
What Happens During the Procedure?
Before percutaneous nephrolithotomy, the patient might need to undergo certain tests to rule out infection. It is a surgical procedure, so general anesthesia will be administered to the patient. Also, the patient must inform the doctor about the medications and the over-the-counter drugs that the patient is taking. It is because the doctor might ask the patient to stop taking these drugs a week before the surgery. The procedure is carried out under the following steps:
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First, the doctor locates the kidney calyx (urine-forming units of the kidneys) with the help of computerized tomography (CT) scan or X-rays.
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Next, a catheter is inserted into the urinary tract through the urethra. A contrast material is injected into the urinary tract through the catheter. This material helps to visualize the structures of the urinary system.
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With the help of X-ray images, a needle is inserted into the calyx to create a path for carrying out the procedure.
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The surgeon then places a sheath along the path of the needle and passes some surgical instruments through it.
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Finally, he breaks the stones into smaller pieces with the help of these instruments.
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A nephrostomy tube might be interested and left in place for a few days to facilitate urine drainage.
What Are the Complications of Percutaneous Nephrolithotomy?
The percutaneous nephrolithotomy procedure came into existence in the 1950s and is preferred by doctors today because of its effectiveness. However, the following complications arise due to percutaneous nephrolithotomy:
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Diaphragmatic Injury - The diaphragm is a dome-shaped muscle located below the lungs. It undergoes rhythmic contraction and relaxation and assists in respiration. The overall chances of diaphragmatic injury from percutaneous nephrolithotomy range from 0.3 to 1 percent. However, the diaphragm and the lung cavity are located near the upper pole of the kidneys. As a result, the chances of lung damage are high during the nephrolithotomy procedure. The patient experiences shortness of breath, fever, and chest pain. In addition to these symptoms, the lung's radiographic changes also help identify the injury.
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Injuries to the Other Organs - The surrounding organs, like the abdomen, liver, and spleen, might get injured during the surgery. Females and patients suffering from splenomegaly (enlarged spleen) and hepatomegaly (enlarged liver) are more likely to suffer organ injuries.
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Bleeding - Bleeding might occur during the day after percutaneous nephrolithotomy. However, the chances of great vessel or renal vessel damage are less. Pseudoaneurysms and arteriovenous fistula are the most common hemorrhagic injuries after the procedure. Pseudoaneurysm is when the blood vessels leak and the blood accumulates in the surrounding tissues. An arteriovenous fistula occurs due to abnormal communication between the artery and the veins.
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Sepsis - Sepsis is a life-threatening condition that occurs due to a severe inflammatory response of the body cells. The patient might go into septic shock because the body’s response damages its own tissues. Intensive medical care and attention are required if the person develops sepsis after a percutaneous nephrolithotomy procedure.
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Renal Dysfunction - Kidney failure or renal dysfunction is one of the most common complications of percutaneous nephrolithotomy. The fluids used for irrigation after the procedure might get absorbed into the kidneys' filtering units. As a result, electrolyte abnormalities, changes in the mental state, and fluid overload are commonly seen. Sometimes, the kidneys fail to function permanently when excessive blood is lost due to postoperative bleeding.
How to Manage the Complications of Percutaneous Nephrolithotomy?
Patients presenting with complications of percutaneous nephrolithotomy require treatment at the earliest. The following treatment options help to manage the complications of percutaneous nephrolithotomy -
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Arterial Embolization: It is a procedure that aims to block the blood vessels that supply the tumor or the abnormal area. Pseudoaneurysms and arteriovenous fistulas are the common complications of percutaneous nephrolithotomy and are treated by arterial embolization. In this procedure, an incision is made in the thigh, and a catheter is inserted and guided into the artery near the tumor.
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Thoracostomy: It is a procedure where a plastic tube is inserted between the lung and the chest wall. Thoracostomy is done to remove the excess fluid from the lung cavity or deliver the medications into it. It is done when the diaphragm or lungs get damaged due to percutaneous nephrolithotomy.
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Bladder Wash: Bladder wash is done when the urinary flow gets restricted due to percutaneous nephrolithotomy. In this procedure, a sterile liquid is injected into the bladder through a catheter to remove blood clots after the surgery.
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Intravenous Fluids: Intravenous fluids are special fluids injected into the body through the veins. It is used when people suffer from septic shock after percutaneous nephrolithotomy.
Conclusion:
Percutaneous nephrolithotomy is a procedure wherein the stones blocking the urine flow are removed surgically. This procedure is done only when the other treatment methods fail to produce the desired results. It is a simple procedure, but complications occur due to various reasons. Sometimes the patient is not fit for the surgery but has to undergo it to save the kidneys. The lungs, abdomen, and diaphragm are in close proximity to the kidneys. As a result, there is a high chance of these organs getting damaged. However, the patient need not worry as the complications do not occur every time and can be managed well.
