Ureteroscopy
Ureteroscopy is the examination of the ureter, and often the renal pelvis and calyces, with a thin telescope passed through the urethra and bladder. It allows direct vision of stones, tumours, strictures and bleeding sites in the upper urinary tract, with the option of biopsy and treatment in the same session.
Semi-rigid ureteroscopes (diameter about 6 to 9 French) are used for the lower and middle ureter, and flexible ureteroscopes reach the renal pelvis and all calyces. It is done under general or spinal anaesthesia, usually with a wire, and often with a ureteric access sheath. Saline is irrigated for vision, and a laser fibre breaks stones, with baskets used to remove fragments. A ureteric stent is often left for a few days to weeks afterwards.
The procedure takes 30 to 90 minutes. For stones, the stone free rate is about 85 to 95% for stones in the lower ureter, 75 to 85% in the upper ureter, and 75 to 90% for renal stones under 2 cm, using flexible instruments. For upper tract urothelial tumours, diagnostic ureteroscopy with biopsy gives a tissue diagnosis in about 80 to 90%.
Indications.
- Ureteric and renal stones that do not pass or are not suitable for other treatment, and stones with infection or obstruction after drainage.
- Haematuria or filling defects in the upper tract with unknown cause.
- Suspected upper tract urothelial carcinoma: diagnosis, biopsy and treatment of selected low grade tumours.
- Ureteric stricture, ureteropelvic junction obstruction, and difficult stent placement.
- Positive urine cytology with normal bladder cystoscopy.
- Foreign body or retained stent fragments.
- Surveillance of patients treated for upper tract tumours.
Not indicated in an untreated urinary infection, except when drainage of an obstructed system is needed.
Contraindications and precautions.
- Untreated urinary tract infection: treat first with antibiotics, and drain an obstructed infected system by stent or nephrostomy before the procedure.
- Uncorrected bleeding disorder, or anticoagulant treatment that cannot be paused.
- Anaesthesia risk, pregnancy (used only when needed), and a very narrow, tortuous ureter.
- Previous ureteric surgery or radiation, with scarring.
- A stent or nephrostomy for 1 to 2 weeks before may be needed to widen the ureter (pre-stenting) for large stones and tight ureters.
- Preoperative urine culture, with prophylactic antibiotics, and preoperative imaging (CT) for anatomy and stone burden.
Preparation and technique.
The patient has imaging (non-contrast CT for stones, CT urography for tumours), a negative or treated urine culture, a blood count, creatinine and clotting tests. Antibiotics are given at induction. In lithotomy position, a cystoscopy is done first, and a wire is passed up the ureter under fluoroscopy.
The ureteroscope is advanced alongside or over the wire, the ureter is inspected, the stone is fragmented or removed, and the pelvis and calyces are examined with a flexible scope. A stent is left when there is trauma, oedema, residual fragments, or a long procedure, and a string or a removal visit is planned.
