2 The procedure
2.1.1 Pelviureteric junction obstruction is a congenital or acquired stenosis of the junction between the renal pelvis and the ureter, which inhibits normal urine flow. It can cause chronic or recurrent flank pain as well as urinary tract infections.
2.1.2 Conservative treatment may include long-term use of low-dose antibiotics. Current surgical options to reconstruct and normalise the anatomy of the PUJ include open or laparoscopic pyeloplasty (with or without robotic assistance) and electrocautery cutting balloon treatment.
2.2.1 The aim of the procedure is to widen the abnormally narrowed part of the PUJ. With the patient under general anaesthesia, a cutting device (which may be a laser or a diathermy probe, or an endoscopic knife) is inserted into the PUJ area endoscopically via the ureter, or via a percutaneous approach in the flank. Under endoscopic visualisation a full-thickness incision is made, through the wall of the ureter, into the periureteric fat. A stent is inserted across the PUJ, with the aim of maintaining patency, and is removed after several weeks.
Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview.
2.3.1 A randomised controlled trial (RCT) of 40 patients treated by laser endopyelotomy versus electrocautery cutting balloon reported a successful outcome (defined as subjective relief or symptom improvement, plus objective relief of obstruction and improvement in glomerular filtration rate) in 85% (17/20) and 65% (13/20) of patients respectively at a mean follow-up of 30 months (p = 0.14). There was no significant difference between the treatment groups in the success rates for patients with primary or secondary PUJ obstruction (p = 0.38 and p = 0.26 respectively).
2.3.2 A non-randomised controlled trial of 436 patients reported that success (defined as complete symptomatic relief plus resolution or improvement in obstruction on imaging) was achieved in 61% (111/182) of endopyelotomy-treated patients and 82% (144/175) of pyeloplasty-treated patients at a mean follow-up of 3.5 years (significance not stated).
2.3.3 A non-randomised controlled trial of 273 patients reported that success (defined as symptom resolution plus improvement or stability of radiographic parameters) was achieved in 60% of patients in the endopyelotomy group, 89% of the laparoscopic pyeloplasty group, and 100% of the robotically assisted pyeloplasty group at a mean follow-up of 20 months (absolute numbers and significance not stated). Multivariate analysis (excluding the robotically assisted group) showed that endopyelotomy (compared with laparoscopic pyeloplasty) was an independent predictor of treatment failure (hazard ratio 3.16; 95% confidence interval 1.70 to 5.86, p < 0.001).
2.3.4 In the non-randomised controlled trial of 436 patients, the 10-year estimated recurrence-free survival was 41% (n = 8) in the endopyelotomy group and 75% (n = 21) in the pyeloplasty group (absolute figures not stated).
2.3.5 The Specialist Advisers listed key efficacy outcomes as short-term pain relief, resolution of symptoms and normalisation of renographic obstruction, preservation of renal function and no obstruction recurrence in the long term.
2.4.1 The RCT of 40 patients treated by laser endopyelotomy versus electrocautery cutting balloon reported no significant difference in the rate of overall complications (not otherwise defined) between treatment groups (10% [2/20] and 25% [5/20] respectively; p = 0.20) (mean follow-up 30-months). The non-randomised controlled trial of 436 patients reported that the rate of overall complications was not significantly different between the endopyelotomy (11% [25/225]) and the pyeloplasty groups (8% [17/211]) (p = 0.33) at a mean follow-up of 3.5 years.
2.4.2 Bleeding requiring transfusion occurred in 1% (3/225) of patients in the endopyelotomy group and 1% (2/211) of patients in the pyeloplasty group in the non-randomised controlled trial of 436 patients (significance not stated). Haemorrhage requiring electrocoagulation occurred in 1% (4/320) and haemorrhage requiring transfusion in 1% (2/212) of patients (1 patient required further intervention [not otherwise stated]) in case series of 320 and 212 patients, respectively.
2.4.3 Ureteral avulsion requiring an open procedure was reported in 1 of 212 patients in a case series.
2.4.4 One case report described a patient who developed renal atrophy, renal hypertension, perinephric fibrosis and calcification, vena caval stenosis and renal vein obstruction after endopyelotomy: the patient needed a nephrectomy 8 years later. The primary event was thought to have been development of a subcapsular haematoma after endopyelotomy. A second case report described ureteral intussusception following endopyelotomy at 3-month follow-up, treated by pyeloplasty reconstruction (not otherwise described).
2.4.5 Reoperation (repeat endopyelotomy, open pyeloplasty or nephrectomy) was required in 10% (33/320) of patients in the case series of 320 patients. In the case series of 212 patients, repeat endopyelotomy was required in less than 1% (1/212), secondary intervention by pyeloplasty in 8% (18/212), ureterocalicostomy in 2% (4/212), and ileal interposition in 1 patient.
2.4.6 The Specialist Advisers listed adverse events as haemorrhage, stent-related problems and aorto-ureteral fistula. They considered theoretical adverse events to include failure/obstruction recurrence, infection, perforation and fibrosis.