Ureterorenoscopy (URS) is an endoscopic procedure to view the ureter (ureter) and kidney (lat. : ren). If only an endoscopic examination of the ureter (ureter) is performed, the examination is referred to as ureteroscopy. Both procedures are equally useful for diagnosis and therapy.
Indications (areas of application)
- Ureteral stones (stones in the ureter) (stone size: – 2 cm).
- Nephrolithiasis (kidney stones).
- Ureteral (ureteral) and renal pelvic pelvic tumors.
- Symptomatic stone road and unsuccessful conservative therapy.
- Clarification of unclear urinary transport disorders (eg, ureteral stenosis).
- Clarification of unclear hematuria (blood admixtures in the urine).
- Treatment of ureteral strictures (high-grade ureteral narrowing) or subpelvic (“below the renal pelvis“) stenosis recurrences (recurrence of narrowing).
- Suspected upper urinary tract (OHT) tumor [URS as a diagnostic measure is superior to all imaging measures].
Absolute contraindications (contraindications)
- Untreated urinary tract infection
- Anticoagulation or coagulation disorders:
- In diagnostic URS no contraindication.
- With stone therapy a relative contraindication
- With planned biopsy (tissue removal) an absolute contraindication.
Notice. Urethral strictures, large prostatic adenomas (prostate enlargement), condition after ureteral strictures and ureteral implantation can make ureteroscopy very difficult.
Before the examination
- Preoperative laboratory testing involves the following parameters: Creatinine and urea (assessment of renal function) and coagulation parameters. Furthermore, a urinalysis with germ counting and urine culture is indispensable
- Before performing ureterorenoscopy, knowledge of the anatomy of the urinary tract is essential for careful planning of the procedure [guidelines: S2k guideline].
- Elicitation of coagulation and urine status.
- Anticoagulants as well as antiplatelet agents (anticoagulants) should be paused before ureterorenoscopy (URS) if possible. URS is also possible under continued anticoagulation and in patients with coagulation disorders after careful risk assessment [guidelines: S2k guideline].
- In the presence of urinary stones, routine ureteral splinting before planned ureterorenoscopy is not required [guidelines: S2k guideline].
- Antibiotic prophylaxis is recommended in most publications, prior to induction of anesthesia.
The procedure
The patient is placed in lithotomy position, which means that the patient is lying on his back with his legs bent at the hip joint at 90 degrees. The knees are bent, and the lower legs are placed on supports so that the legs are spread about 50 to 60 degrees apart. Special endoscopes with light, optical and working channels are used to see and evaluate the ureter and renal pelvis. The instruments are equipped with a light source and are inserted through the urethra into the bladder and then further into the ureter. The devices come in both rigid and semi-flexible versions. Different instruments can be inserted through a working channel for disintegration (intracorporeal lithotripsy; for felxible URS, the holmium:YAG laser is the gold standard and extraction (removal using grasping forceps, dormia basket/stone catcher basket) of ureteral stones as well as for biopsy (tissue extraction using biopsy forceps). Small stones can be extracted whole using auxiliary instruments (grasping forceps, Dormia basket). Larger concretions are lithotripsed (broken into individual fragments) using pneumatic, electromechanical or laser energy. If a tumor of the upper urinary tract (OHT) is suspected, photodynamic diagnosis (PDD) is usually performed, i.e. fluorescent material is selectively absorbed into malignant tissue and can then be detected under a specific wavelength of light. The procedure is performed under general anesthesia (laryngeal mask (laryngeal mask) or intubation anesthesia; spinal/spinal regional anesthesia may also be used). The duration of the procedure depends on the different indications. For stone therapy, the average procedure time is about half an hour to one hour.
Results [Guidelines: S2k Guideline]
- Distal ureter: SFR 93%.
- Middle ureter: SFR 87 %
- Proximal ureter: SFR 82 %
- Kidney stones: SFR 81% (including second intervention: 90%).
SFR = stone-free rate after 3 months.
After the examination
- Monitoring for one to two hours after surgery in the recovery room.
- Removal of the bladder catheter on the first day after surgery. This is inserted during the operation.
- Discharge usually occurs on the second day after surgery.
- After the procedure, a temporary insertion of a ureteral splint (double J-catheter, pigtail catheter) is necessary. This is usually removed after 7 to 14 days by the resident urologist. This does not require anesthesia.
Possible complications
- Short-term hematuria (blood admixtures in urine): 0.5-20%; if bleeding → forced diuresis (greatly increased urine production with the help of diuretics (dehydrating drugs)).
- Fever -15%) or sepsis (blood poisoning): 1.1-3.5% → antibiotic therapy.
- Ureteral (ureteral) injuries.
- Ureteral rupture: 01-0.2%; 0.04-0.9%.
- Ureteral perforation (“perforation of the ureter”): approx. 1.6%.
- Ureteral stricture/formation of a scarred stricture of the ureter/ureteral stricture): 0.1%.
- Ureteral mucosa/ureteral mucosa injuries (-46%).
- Renal colic/flank pain: 1.2-2.2%.
- Serious complications (reconstructive follow-up procedures required) of ureterorenoscopy are rare and occur in less than 1% of cases [guidelines: S2k guideline].
- Postureteroscopic deaths due to urosepsis (acute infection with bacteria from the urogenital tract): incidence (frequency of new cases) is 0.1-4.3%.
- Late complications after ureteroscopy.
- Ureteral obstruction or stone roads (0.3-2.5%)
- Ureteral strictures (3%)
- Hydronephrosis (“water sac kidney”) – dilatation of the renal cavity system, which is associated with destruction of renal tissue in the medium and long term (15.1-32.1%)
