An endopyelotomy is a minimally invasive surgical technique designed to correct a blockage in the urinary system. The procedure addresses a narrowing where the kidney meets the ureter, the tube that transports urine to the bladder. By widening this constricted area, the surgery restores normal urine flow, alleviating symptoms and preventing potential kidney damage.
The Condition Treated by Endopyelotomy
This procedure treats a ureteropelvic junction (UPJ) obstruction. The ureteropelvic junction is the point where the renal pelvis, the central collecting part of the kidney, funnels urine into the ureter. When this junction is blocked, urine cannot drain properly from the kidney, causing it to back up and leading to a condition called hydronephrosis, which is a swelling of the kidney.
This obstruction is frequently congenital, present at birth due to abnormal development of the ureter’s muscle, which creates a narrow segment. However, UPJ obstruction can also develop in adults. Acquired causes include the formation of scar tissue from previous surgeries, chronic inflammation, kidney stones, or external compression from a misplaced blood vessel.
Symptoms of a UPJ obstruction can include:
- Flank or back pain, which can be persistent or intermittent
- Recurrent urinary tract infections (UTIs) accompanied by fever
- Blood in the urine (hematuria)
- Nausea and vomiting
In some cases, a physical examination may reveal a palpable lump in the abdomen. If left untreated, the constant pressure from urine buildup can lead to a gradual loss of kidney function.
The Endopyelotomy Procedure
An endopyelotomy is performed under general anesthesia. The surgery utilizes an endoscope, a thin, flexible tube with a camera and light, to see inside the urinary tract without a large incision. The procedure can be performed using one of two primary approaches: retrograde or antegrade.
The retrograde approach is the more common method. The surgeon inserts the endoscope through the urethra, passes it through the bladder, and advances it up the ureter to the blockage. Once the narrowed area is identified, the surgeon uses specialized instruments passed through the endoscope to make a precise cut.
The antegrade approach involves accessing the kidney directly through a small puncture in the patient’s back. The surgeon creates a pathway into the kidney’s collecting system. A guidewire is maneuvered across the obstructed segment and down into the bladder, and a type of endoscope called a nephroscope is then introduced to make the incision from within the kidney.
For either approach, the surgeon makes a full-thickness cut through the narrowed wall of the ureteropelvic junction using a tiny knife, an electrocautery probe, or a laser fiber. The goal is to cut completely through the scar tissue or narrowed segment. A balloon catheter may then be used to dilate the newly opened area. To conclude the procedure, a temporary ureteral stent is placed across the incised area to keep it open and act as a scaffold during the healing process.
Recovery and Post-Procedure Care
Following the endopyelotomy, patients are monitored in a recovery room. A hospital stay is short, often just one night. Mild discomfort, frequent urination, and a small amount of blood in the urine are common for a few days, and patients are encouraged to drink more fluids to flush the urinary system.
The ureteral stent is a soft, plastic tube that extends from the kidney to the bladder. This stent ensures that urine can drain freely while the incised junction heals and prevents the walls from re-narrowing. While the stent is in place, patients may experience some bladder irritation or a sensation of needing to urinate frequently.
The temporary stent is removed four to six weeks after the surgery. Removal is a straightforward office procedure, sometimes using a local anesthetic. A return to non-strenuous activities can occur within one to two weeks of the procedure.
The surgeon will schedule appointments to monitor healing and confirm the operation’s success. These appointments involve imaging tests, like a kidney ultrasound or nuclear renal scan, to verify proper kidney drainage and that the obstruction is resolved.
Comparing Treatment Options
Endopyelotomy is not the only surgical option for a UPJ obstruction. The main alternative is a pyeloplasty, which can be an open, laparoscopic, or robotic-assisted surgery. Unlike an endopyelotomy that incises the blockage, a pyeloplasty involves excising the narrowed segment of the ureter and reattaching the healthy ureter to the renal pelvis.
Endopyelotomy is less invasive than pyeloplasty. It involves a shorter operating time, a faster recovery, less postoperative pain, and a quicker return to normal activities. This makes it an appealing option for certain patients.
However, the primary trade-off is in long-term success rates. Pyeloplasty has higher long-term success rates, exceeding 90-95%. The success rates for endopyelotomy are lower, around 80-90%. The choice between procedures depends on patient factors, the obstruction’s anatomy, and a discussion with a urologist.