Kidney stones (percutaneous nephrolithotomy)

Percutaneous nephrolithotomy is used for the surgical treatment of kidney stones. Most of the kidney stones in children are caused by infection. Boys are more common than girls, and the highest incidence is between 2 and 3 years old. The most common pathogenic organism is Proteus or Escherichia coli that breaks down urea. Repeatedly there is a soft stone formed by the genus Proteus in the urine, which contains a large amount of biological matrix, often X-ray transparent stone. The stone composition contains magnesium ammonium phosphate (streptite) and a small amount of calcium phosphate (apatite), oxalate, carbonate and urate. These components may be attached to the renal pelvis and renal pelvis system freely or in a wide range, sometimes with renal pelvis, perirenal abscess or progressive pyelonephritis. Children have fewer metabolic stones. Hypercalcemia can be idiopathic or caused by excessive vitamin D or hypophosphatemia, usually causing renal calcium deposits. Hyperparathyroidism is rare in children. High calcium urine is defined as 24h urinary calcium above 4mg/kg and urinary calcium/creatinine ratio >0.25. Hypercalciuria also occurs in some children with infected stones, especially when milk is excessive. Phosphateuria can cause renal tubular acidosis, hypercalciuria and recurrent urinary stones in addition to renal calcium deposition, high oxalic acid can also produce renal calcinosis and recurrence of oxalate stones. If the urinary tract is obstructed, it is more likely to occur. Uric acid stones often occur in children with leukemia, often due to calcium salt deposition, opaque on X-ray films, but low density. Astragalus and aqueous gland stones are light-transmitting stones. Treatment of diseases: kidney stones Indication After the renal pelvis and upper ureteral calculi and extracorporeal shock wave lithotripsy, larger lithotripsy can not be discharged, and percutaneous nephrolithotomy can also be considered. For children with percutaneous nephrolithotomy or ureteroscopic approach to lithotripsy, there is no suitable endoscopic device yet, and it has not been widely carried out. Contraindications 1. Preoperative examination 1 Radiation examination: Abdominal plain film, including total urinary tract pyelography and B-ultrasound showed urinary tract obstruction and other abnormalities; excretory cystography mainly determines whether there is vesicoureteral reflux. 2 urine analysis: urine routine and urine culture. Determination of urine pH, sterile urine pH should be less than 5.3, do 24h urinary calcium, oxalate excretion test. 3 serological tests: creatinine, urea nitrogen, electrolytes, calcium, phosphate, uric acid examination. It is more necessary to do the above biochemical examination when there is renal calcium deposition or recurrence of stones. 2. Intestinal preparation. 3. Apply antibiotics to prevent infection. Surgical procedure 1. Percutaneous expansion, taking the 12th rib of the affected side, corresponding to the position of the rib angle, 0.5% procaine local infiltration anesthesia, percutaneous nephrolithotomy needle 18~22 to the lower renal pelvis to the renal pelvis . Under fluoroscopy, it was confirmed that the needle had urine droplets in the renal pelvis, and the guide wire was placed in the renal pelvis by the kidney puncture needle. Expansion is performed with a telescopic metal dilator under the guidance of a guide wire. The ureter is inserted into the balloon catheter to prevent stones from slipping into the ureter. 2. Crushed stone calculus, smaller pyelone stones can be inserted into the stone tongs through the nephroscope sheath, and the small stone mechanical clamp is broken by the stone tongs. The staghorn stones can be broken with an ultrasound probe under direct vision.