Ureteropelvic Junction Obstruction

• Introduction

Ureteropelvic junction obstruction is the presence of a stricture at the junction of the kidney with the ureter. The disease is benign and is observed in 1 of 1500 children as well as adults. The presence of an ectopic kidney vessel pressing on the external side of the junction is the most common anatomic cause. Other causes of disease are the injury of the junction, urolithiasis and previous infections. As a result of the stricture, the production of urine in the kidney is greater than the quantity of urine can be evacuated to the ureter and renal pelvis (the part of the kidney associated with the ureter) begins to dilate. The effects of ureteropelvic junction obstruction depend on the degree of obstruction and can range from an asymptomatic state until the complete destruction of the kidney. Other complications of the disease are frequent infections, kidney stones and flank pain caused by the dilation of the kidney.

• Diagnosis

The diagnosis of ureteropelvic junction obstruction can be made by imaging methods such as CT-urography, intravenous pyelography and especially with a functional renal scintigram.

• Treatment

The management of ureteropelvic junction obstruction takes place by either opening the stricture endoscopically or by surgical reconstruction of the ureteropelvic junction.

• Endourological treatment of ureteropelvic junction obstruction

The endourological management (endopyelotomy) includes the opening of the stricture by knife, laser or balloon. In all cases, access to the area of stricture can be done in two ways:
⇒  Antegrade (percutaneous): through a small flank incision a nephroscope (endoscopic instrument which provides visibility into the kidney) is introduced to the renal pelvis above the stricture. An endoscopic knife or a laser device is used to incise the stricture.
⇒  Retrograde (transurethral-ureteroscopic): a ureteroscope is introduced through the urethra, then the bladder and into the ureter and is then advanced to below the stricture on the ipsilateral ureter. Dilation of the narrowed portion is then performed with the laser, balloon or knife.

The main advantage of the endourological management is the association with very low morbidity and the patient returns to normal pre-surgery activity soon after the procedure. Nevertheless, recurrence of the stricture is more common in the comparison to other approaches for treatment of ureteropelvic junction obstruction. The patient leaves the hospital on the same day of the procedure and returns immediately to normal activity.

For the performance of endopyelotomy, a knife is used to open the lumen of the stenosed ureter. The method is extremely effective in the case of strictures associated with fibrosis of ureteropelvic junction (strictures after inflammation, injury, or kidney stones) with 82-86% overall efficiency. However, some of the strictures are expected to recur in the future. Postoperative pain is minimal. The patient leaves on the day of surgery. In the case where percutaneous nephrostomy is needed, the tube is removed after 2 weeks.

• Laparoscopic pyeloplasty

The treatment of choice for the treatment of ureteropelvic junction obstruction is the surgical reconstruction of ureteropelvic junction. The method is indicated in the treatment of all strictures regardless of etiology and its efficacy is close to 100%. Laparoscopic pyeloplasty combines the excellent efficacy of surgical repair with the limited morbidity of minimally invasive methods.

In laparoscopic pyeloplasty, the surgical instruments are inserted into the abdomen through incisions on the abdominal wall. The area of stenosis is removed. The ureter is sutured to the renal pelvis resulting in the creation of a new ureteropelvic junction.

A ureteral catheter is left in the ureter as it facilitates the healing process.
Laparoscopic pyeloplasty is associated with minimal morbidity. The blood loss is negligible and the patient is usually mobilized and eats on the first postoperative day, while the hospital discharge takes place on the second day after the surgery. The ureteral catheter is removed after 3 weeks and the removal process is painless.

• Single-site laparoscopic pyeloplasty

Laparo-endoscopic single-site pyeloplasty is a variant of classical laparoscopic pyeloplasty in which all surgical instruments are imported from the umbilicus through a single small hole.

Since the scar of the incision is hidden in the umbilicus postoperatively, the single-site surgery does not leave visible scars (scarless surgery). Although the procedure is technically demanding for the surgeon, the technique is proposed for younger people who want to have the best cosmetic result. The results of this alternative technique are identical to the standard laparoscopic approach.

• Complications

Complications of laparoscopic pyeloplasty are rare. Recurrence of stricture, intra-operative bleeding by vessel injury, infection of the incision and injury to an adjacent organ are rare complications. The frequency of complications is related to the surgical experience and decreases significantly when surgery is performed in well-trained surgical centers.