Endopyelotomy is a minimally invasive surgical technique used by urologists to correct an obstruction in the urinary tract. The procedure’s primary objective is to relieve a blockage at the ureteropelvic junction (UPJ), which is the area where the kidney connects to the ureter. This endoscopic approach offers a less invasive alternative to traditional open surgery, restoring normal urine flow from the kidney to the bladder and resulting in quicker recovery and less discomfort.
Understanding Ureteropelvic Junction Obstruction
Ureteropelvic junction obstruction (UPJO) occurs when there is a narrowing or functional blockage where the renal pelvis (the part of the kidney that collects urine) joins the ureter (the tube carrying urine to the bladder). This constriction impedes the proper drainage of urine, causing it to back up and pool within the kidney’s collecting system. The resulting swelling of the kidney is a condition known as hydronephrosis, which can progressively lead to decreased kidney function and damage if left untreated.
The obstruction can be present from birth, known as congenital UPJ obstruction, or it can develop later in life due to factors like scar tissue, kidney stones, or a crossing blood vessel that compresses the ureter. Common symptoms include chronic or intermittent flank pain (which may worsen with increased fluid intake), recurrent urinary tract infections (UTIs), and sometimes blood in the urine.
Diagnostic tools are used to confirm UPJ obstruction and determine the need for intervention. Imaging tests such as an ultrasound or a computed tomography (CT) scan help visualize the degree of kidney swelling and assess the anatomy of the urinary tract. A specialized test called a diuretic renal scan (often a MAG-3 scan) is frequently used to objectively measure kidney function and the rate at which urine drains past the obstruction.
How the Endopyelotomy Procedure is Performed
Endopyelotomy is typically performed under general or spinal anesthesia, ensuring the patient remains comfortable and still throughout the procedure. The technique is endoscopic, meaning the surgeon accesses the urinary system through natural openings (the urethra and bladder), eliminating the need for external incisions. A flexible instrument called a ureteroscope is used for this approach.
The surgeon guides the ureteroscope through the bladder and up the ureter until the ureteropelvic junction obstruction is reached. A thin guide wire is first positioned across the narrowed segment to maintain access and guide the instruments. Specialized instruments are then advanced to incise the stricture, effectively cutting through the scar tissue causing the blockage while avoiding injury to surrounding blood vessels.
The cutting is performed using advanced technology, such as a Holmium:YAG laser fiber or an electrocautery device, which allows for a precise, full-thickness incision of the constricted tissue. The goal is to open the narrowed passage to the full diameter of the ureter while minimizing damage to the surrounding structures. Once the incision is complete and the blockage is relieved, the success of the procedure depends on the area healing in an open, non-scarred configuration.
The final and most important step of the procedure is the placement of a temporary internal tube known as a double-J ureteral stent. This stent spans the length of the ureter, from the kidney down to the bladder, holding the newly incised area open during the healing process. The stent acts as a scaffold, allowing urine to drain freely and bypassing the surgical site, which prevents the incision from closing due to scar tissue.
Recovery and Long-Term Expectations
The recovery phase begins immediately after the procedure, with many patients being discharged from the hospital within one to three days. Patients are discharged with the internal double-J stent in place, which is a temporary but necessary part of the healing process. The stent is left for an extended period, generally four to six weeks, to ensure the surgical site at the ureteropelvic junction heals completely in a widened state.
During the time the stent is in place, patients often experience some degree of discomfort, which can include flank pain, bladder irritation, and an increased frequency and urgency of urination. Pain management is addressed with oral medication, and patients are advised to avoid strenuous activity or heavy lifting until the stent is removed. Blood in the urine is also common while the stent is present.
The stent removal is a separate, quick, and minimally invasive procedure performed in the doctor’s office, usually under local anesthesia or light sedation. Once the stent is removed, the majority of patients can return to their normal activities within a few days. The total recovery time is short, allowing for a faster return to work and daily life.
While endopyelotomy has a relatively high success rate, complications can occur, with failure of the procedure being the primary long-term concern. Potential issues include bleeding, infection, or the formation of new scar tissue, which may require a repeat procedure or a different surgical approach. The overall success rate, defined by symptomatic relief and improved drainage, averages around 77% to 85%.
Long-term prognosis is monitored closely through follow-up imaging, most commonly with a repeat diuretic renal scan and ultrasound, performed at three to six months post-stent removal. These tests confirm the patency of the newly opened UPJ and verify that the kidney’s function and drainage have improved or stabilized. Close monitoring for at least 36 months is recommended, as most failures (indicated by the return of symptoms or hydronephrosis) tend to occur within the first year.