Urethral catheterisation is a diagnostic or therapeutic procedure consisting in the introduction into the ureter or the kidney of a urethral catheter through a cystoscope.
It is a diagnostic procedure:
- in the case where it is followed by the injection of a contrast fluid for performing a retrograde ureteropyelography;
- if the case a selective cytological examination of the urinary tract is required (collecting the cleaning injected fluid through the catheter).
It is a therapeutic procedure to be applied in case of intrinsic or extrinsic ureteral obstruction.
For over 30 years, but mainly in the last 15 years, autostatic urethral catheters are commonly used in clinical practice, so today, speaking of ureteral catheterization for obstruction is almost always referred to as “autostatic stent positioning”.
But non-autostatic ureteral catheterization still has precise indications:
- Functional kidney evaluation through the selective measure of eliminated urine and its quality (little practiced);
- Pyonephrosis catheterization with large meshed catheters that function by gravity, better than a stent that always requires ureteral peristalsis (useful in selected cases) for optimal functioning;
- Short-term catheterization (24-48 hours) following operative maneuvers such as ureteroscopy, when it is desired to prevent ureteral obstruction from edema.
Description of the technique:
Ureteral catheterization is performed in an operating or endoscopic room, on a radiotransparent bed, with the aid of a image amplifier. It can be done in local anesthesia, in sedation, or in rare cases in anesthesia.
The cystoscope is inserted into the bladder: through this, a small catheter is passed through (the ureteral catheter) that is inserted into the ureteral meatus. From here the catheter proceeds through the ureter until the obstacle is reached. To overcome the obstacle, if this is not easily accomplished, special ureteral catheters are used in which guided wires can pass that can overcome the obstacles with particular movements and allow the ureteral catheter to reach into the kidney pelvis and drain the obstructed kidney. Afterwards the autostatic catheter can be applied, which is equipped with a double comma (or j or pork tail) which hooks in the kidney and bladder, thus becoming autostatic. After this operation, a bladder catheter can be left for 24 hours in order to avoid reflux from bladder stenosis that occurs especially in the early hours.
Preparation for intervention:
The chemo antibiotic prophylaxis should start the day before surgery if it is a diagnostic procedure. If ureteral catheterization is instead a procedure to resolve an obstruction, the patient is usually already taking antibiotic therapy.
It is always useful, if possible, a good bowel preparation.
Duration of intervention:
The execution times are very variable: from very few minutes in case of easy overcoming of the obstruction to longer times (max 15-20 minutes) in case a complex obstruction is faced.
Type and duration of hospitalization:
The procedure can be performed in outpatient, in Day Hospital or in-hospital care depending on the type of obstruction, the type of anesthesia and the type of patient.
The results in terms of procedure success are good almost always.
This is a simple technique, mini-invasive procedure that can solve urethral obstructions of any kind.
Premature obstruction of the ureteral catheter does not allow optimal functioning when ureteral peristalsis is no longer valid (neoplastic ureter, ureteral extended fibrosis). In these cases the best drainage is obtained with percutaneous nephrostomy.
Stent ureteral catheter carriers usually complain, especially in the early days of irritable urinary disorders, in relation to the intolerance of the bladder extremity of the stent. There is, however, a variability of tolerance in relation to the composition of the stent and in relation to the patient’s personal tolerance.
Early postoperative complications are:
- Lumbar pain sometimes linked to bladder-kidney reflux;
- Hematuria, both due to trauma and irritation produced by the ureteral catheter;
- Bladder irritation symptoms (muscular frequency, urgency, incontinence, etc.) due to mechanical contact of the lower extremity of the stent with the bladder wall (very variable, from absolute tolerance to total intolerance that sometimes requires removal of the stent).
Late complications are:
- Development of incrustations, very variable in relation to the chemical-physical characteristics of the patients urine; Can affect the proximal or distal extremity and sometimes the whole stent;
- Stent de-positioning: upwards, in this case it must be re-positioned through surgical ureteroscopy; downwards, in this case should be re-positioned with a new cystoscopy maneuver;
- Obstruction of the stent with no peritubular outflow: this is an occurrence that occurs frequently when faced with an extrinsic obstruction of a neoplastic nature; in these cases, the extrinsic constraint by the neoplastic mass and the neuro-muscular infiltration of the ureter with the peristalsis block resulting therefrom, let the stent function only via intracanalicular, but this has a short duration. In such cases, the best drainage of obstruction is percutaneous nephrostomy, provided that the patient, having a long life expectancy, couldn’t instead benefit from a suitable surgical urinary derivation;
- Stent breakage: it usually happens when the stent is kept by the patient beyond the prescribed limit for the specific material. The patient must be provided with the tag specifying the date for removing or possibly replacing the stent;
- Symptomatic urinary tract infection is quite common in stent carriers; it is not always treatable successfully with antibiotics.
Care to take at discharge of the patient:
After the surgery, the patient undergoing stent placement must undergo antibiotic therapy and sometimes along with bladder anti-spasmal to avoid cysto-spasm from intolerance of the bladder extremity of the stent. It is recommended to drink a lot in order to have abundant diuresis.
The patient must be given a tag stating the stent removal date. This information should also be included in a hospital record.
How to behave in case of complications arising after discharge:
In the case of bladder irritation, it may use selective bladder-specific anti-spasm drugs prescribed by the treating physician.
In case of persistent fever and pain after 6-7 days, the reference urological center must be recontacted because a probable malfunctioning stent.
Must perform radiographic, ultrasound and laboratory examinations in relation to the obstructive pathology for which the stent has been placed.