Generality
The ureteral stent is a thin and soft brace that is introduced into the ureter to keep it free and facilitate the passage of urine, from the kidney to the bladder.
This small tube is used to prevent or quickly resolve a picture of obstruction of the upper urinary tract, secondary to kidney stones, strictures, tumors or other pathological conditions.
The ureteral stent runs from the renal pelvis to the bladder, so it has no visible parts outside the body. This type of guardian is left in place for a variable period from a few days to several weeks.
As a rule, the ureteral stent is inserted through the support of a cystoscope, in such a way as to verify its correct positioning. The brace introduced into the ureter may have various characteristics, but usually has one or two rolled ends. This conformation ensures the maintenance of the ureteral stent in place.
What's this
Short introduction: what are ureters?
The ureters are two channels that originate from the kidneys and run downwards, parallel to the spine, connecting these organs to the bladder.
What is the ureteral stent?
The ureteral stent (or ureteral brace ) is a thin tube, which is introduced along one or both ureters. Its function is to put the kidney in communication with the bladder, quickly resolving the obstruction of the urine flow.
Ureteral stents are almost always internal and tense, that is, they have one or both ends wrapped around themselves; this conformation makes the braces stable in their place, without ascending towards the kidney or descending into the bladder.
The main diseases for which the positioning of the ureteral stent is indicated are:
- Urinary calculations;
- Tumors of the upper urinary tract;
- Ureteral strictures.
Characteristics and types of ureteral stents
- The ureteral stent is a soft and flexible brace, usually made of plastic.
- Unlike a ureteral catheter, the stent ends in the bladder. Once positioned, this tube is invisible from the outside, as it is kept completely inside the patient. The ureteral catheter continues, however, into the urethra and exits outside along with the bladder catheter.
- Depending on the patient's pathology, the ureteral stent may be unilateral or bilateral .
- Approximately, the size of the brace is comparable to that of a spaghetti. In adult patients, the length of the ureteral stent varies from 24 to 30 cm. The diameter and thickness of the tube are also different, to better adapt to the patient's ureter.
- The types of ureteral stents can be multiple. In most cases, a device with two "curls" at the ends is used . This conformation - called in technical terms " double J " or " double pigtail " - ensures that the ureteral stent is kept in place: one end remains in the renal pelvis and the other in the bladder.
What is it for?
The ureteral stent allows the drainage of urine from the kidney directly into the bladder or into a special collection device .
This small tube is used, in practice, to prevent or quickly resolve an impairment in functioning (as can happen, for example, in the case of a tumor even in the presence of another nearby organ) or an obstruction of the upper urinary tract due to intrinsic or extrinsic (eg kidney stones). In the surgical field, the ureteral stent is also useful to avoid the onset of annoying post-operative complications, secondary to the inflammation of the ureter or neighboring tissues that can occur due to the maneuver itself.
Long-term or temporary ureteral stent
The ureteral stent may be:
- Long stay : positioning and replacement occur regularly for a few months or years. The long-stay stent is used for the purpose of bypassing urinary tract obstructions, in the presence of various pathologies, to allow perfect healing of the ureteral wall.
- Short stay : the device is temporarily held for a few days or a few weeks. These ureteral stents are usually used in association with surgical procedures on the urinary tract or in the vicinity of it, to protect the ureters from injury and to facilitate post-operative functional recovery.
Ureteral stent: when is it indicated by the doctor?
The ureteral stent has a therapeutic value: once introduced into the lumen of the ureter, this tube maintains its patency, so as to allow the outflow of urine to the outside . The brace also prevents damage from renal stasis, preserving kidney function, up to the removal of the calculus or the resolution of other causes of urinary obstruction.
Indications for placement of the ureteral stent include:
- Ureteral stenosis (narrowing);
- Urinary tract calculi;
- Tumors of the urinary tract;
- Neoplastic processes affecting contiguous organs, capable of causing a compression of the ureter;
- Diseases of the retroperitoneum.
The introduction of the ureteral stent can sometimes be difficult or impossible. In these cases, depending on the type of obstruction, a percutaneous nephrostomy can be proposed to the patient.
How it is positioned
The placement of a ureteral stent is a minimally invasive endoscopic procedure .
Usually, the brace is retracted back into the ureter through the urethra by retrograde means, thanks to the support of a guide wire and a flexible cystoscope (a tool widely used in the urological field, at the end of which the stent is connected). The correct position of the upper end of the stent is verified during the procedure thanks to radioscopy (X-rays).
Alternatively, the ureteral stent can be positioned via percutaneous anterograde or combined technique.
Usually, the procedure is performed on an outpatient basis, following the administration of local anesthesia.
Entry procedure
The application and any subsequent replacement of the ureteral stent are carried out during cystoscopy and with the aid of a radiological guide, which verifies its correct position.
The ureteral stent is maintained within the body for periods of time that are established, from time to time, by the referring physician, based on the patient's pathology and clinical data. The double curl ureteral stent may remain in place up to 6-8 months, but must be checked and replaced to prevent or avoid the appearance of infectious complications.
After positioning
After the procedure, the patient must start a bladder antispasmodic therapy, to avoid cystospasm from intolerance of the bladder end of the stent.
Furthermore, it is advisable to drink a lot in order to have an abundant diuresis to reduce the chances of contracting a urinary infection.
Removal of the ureteral stent
Usually, removal of the ureteral stent is performed by the doctor in an outpatient procedure, which involves introducing a cystoscope with a forceps into the bladder.
To remember
If maintenance of the ureteral brace is necessary for prolonged periods, a periodic replacement is envisaged to limit the likelihood of incurring urinary tract infections . Over time, moreover, in relation to the chemical and physical characteristics of the patients' urine, the ureteral stent is subject to scaling .
Duration of the intervention
In relation to the type of obstruction and the patient's general conditions, the ureteral stent positioning procedure is performed in "day surgery" or in a hospitalization regime.
The times for the execution of the intervention are very variable: from a few minutes to longer times (about 15-20 minutes), if you are faced with a more complex obstruction.
Preparation
Before placing a ureteral stent, a prophylactic antibiotic regimen is required, for a period to be indicated by the doctor, based on the needs of the case.
Complications and Risks
The ureteral stent is a soft and elastic tube, which allows us to lead an almost normal life . However, for some patients, this device is not very tolerable and can cause pain in the ureteral mucosa.
Early complications
In the first days after the operation, it is possible to develop irritative urinary disorders (such as burning, frequency and the sensation of having to urinate even when the bladder is empty). These side effects of the ureteral stent can be alleviated with appropriate symptomatic drugs.
Other early complications include:
- Presence of blood in the urine ( hematuria ) due to trauma and irritation of the ureteral walls (in general, this manifestation resolves spontaneously);
- Lumbar pain related to the reflux of urine towards the kidney, which the stent determines during urination (note: vesico-renal reflux is an eventuality that may require the positioning and maintenance of a bladder catheter).
Late complications
Prolonged permanence of the ureteral stent can lead to the appearance of complications such as:
- Bleeding (normally, poor);
- Dislocation of the stent, which may require repositioning;
- Scale development;
- Infections;
- Brace fracture;
- Ureteral erosion;
- Stent obstruction (due to scarring of the ureteral tissues or extrinsic constriction by a neoplastic mass);
- Perforation of adjacent organs, such as intestine or bladder.
Any rolling or knotting of the stent inside the ureter typically causes irritative urinary symptoms, including:
- Urinal urgency;
- Increased frequency of urination (pollakiuria);
- Sense of incomplete emptying of the bladder after urination;
- hematuria;
- Abdominal, pelvic or hip pain during and just after urination.
These disorders are usually temporary and resolve with the removal of the ureteral stent.
When should I go to the doctor?
If the pain and a persistent fever occur after a week after the operation, it is advisable to consult the doctor or the urologist of reference, as it is likely a malfunction of the ureteral stent.
Precautions and warnings
- Patients with ureteral stents may have a completely normal life, except for possible discomfort during intense physical exertion . When there is a lot of discomfort or pain it is possible to benefit from taking painkillers (eg paracetamol or non-steroidal anti-inflammatory drugs) and / or alpha-lithic drugs (eg tamsulosin, alfuzosin etc.) indicated by the doctor.
- After placing a ureteral stent, it is advisable to drink plenty of water to prevent a urinary infection and reduce the presence of blood in the urine. Abundant hydration also contributes to the treatment of the stones.
- As for sexual activity, caution is advised and the use of condoms for protection from sexually transmitted diseases. In humans, the ureteral stent is placed on the prostate and, during ejaculation, it can cause irritation and cramping pelvic pain.
- During the stay of the ureteral stent in place, the patient must undergo radiographic, ultrasound and laboratory checks, in relation to the obstructive pathology for which the bracing was placed and the recommendations of his doctor.
