Urethral catheterisation is a diagnostic or therapeutic procedure consisting in the introduction into the ureter or the renal pelvis of a urethral catheter through a cystoscope.
It is a diagnostic procedure:
a) in the case where it is followed by the injection of contrast media for practicing retrograde ureteropyelography;
b) in the case where a selective cytological examination of the urinary tract is required (collecting the injected fluid through the catheter).
It is a therapeutic procedure to be applied in case of intrinsic or extrinsic urethral obstruction.
For over 30 years, but most of all, in the last 15 years, autostatic urethral catheters are commonly used in clinical practice, so today, speaking of urethral catheterization for obstruction is almost always referred to as “autostatic stent positioning”.
But non-autostatic urethral catheterization still has precise indications:
- Functional kidney evaluation through the selective elimination of urine and their quality (not much performed);
- Pyonephrosis catheterization with large meshed catheters that function by fall, better than a stent that always requires urethral peristalsis (useful in selected cases) for optimal functioning;
- Short-term catheterization (24-48 hours) following operative procedures such as ureteroscopy, when it is desired to prevent urethral obstruction from edema.
Urethral catheterization is performed in an operating or endoscopic room, on a radiotransparent bed, with the aid of a brilliancy amplifier. It can be done in local anesthesia, in sedation or in exceptional cases in anesthesia.
The cystoscope is inserted into the bladder: through this one passes a small catheter (the urethral catheter) that is inserted into the urethral meat. From here you proceed to the urethra until you reach the obstacle. To overcome the obstacle, if this is not simply done, urethral catheters are used in which passages guiding wires can pass that overcome the obstacles with particular movements and allow the urethral catheter to reach into the kidneys and drain the obstructed kidney. You can then apply the autostatic catheter, which is equipped with a double comma (or j or pork tail) with settles in the kidney and bladder, thus becoming autostatic. After this operation, a bladder catheter may 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 urethral catheterization is understood as a procedure to resolve an obstruction, the patient is usually already taking antibiotic therapy.
It is always useful, if possible, a good bowel preparation.
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 of a complex obstruction.
Type and duration of hospitalization:
The procedure can be performed in outpatient setting, in Day Hospital or in in-patient setting depending on the type of obstruction, the type of anesthesia and the type of patient you are dealing with.
The results in terms of success of the procedure are almost always good.
This is a technically simple, mini-invasive procedure that can solve urethral obstructions of any kind.
Premature obstruction of the urethral catheter does not allow optimal functioning when urethral peristalsis is no longer valid (neoplastic urethra, urethral 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 material of the stent and in relation to the patient’s personal tolerance.
Post-operative complications are:
- Lumbar pain sometimes linked to bladder-kidney reflux;
- Hematuria, both due to trauma and irritation produced by the urethral catheter;
- Bladder irritation symptoms (urination 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 stent removal).
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 misplacement: if upwards, it must be recovered through operating ureteroscopy; if downwards, it should be repositioned with a new cystoscopy maneuver;
- Obstruction of the stent with no outflow: this is an occurrence that occurs frequently when faced with an extrinsic obstruction of a neoplastic nature; In these cases, the extrinsic constraint due to the neoplastic mass and the neuro-muscular infiltration of the ureter with the peristalsis block resulting therefrom, let the stent function only 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, can not benefit from a suitable surgical urinary derivation;
- Stent breakage: It usually happens when this is kept by the patient beyond the prescribed limit for the specific material. The patient must be provided with the dated tag that specifies the time 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.
After the surgery, the patient undergoing stent placement must undergo antibiotic therapy and sometimes with bladder anti-spasm drugs to avoid cystospasm 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 card 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, selective bladder-specific anti-spasm may be used if prescribed by the treating physician.
In case of persistent fever and pain after 6-7 days, the reference urological center must be contacted because we are probably facing a malfunctioning stent.
radiographic, ultrasound and laboratory examinations must performed in relation to the obstructive pathology for which the stent has been placed.