A stent is a mechanism that is placed inside the vena cava and ducts to expand the tapering sections. Let's take a closer look at how the kidney stent works and how it looks. And at the same time we will tell why it is introduced. As a rule, a stent is most often prescribed for kidney stones or when the outflow of urine is impaired due to adhesions.
The operation is quick and easy. In most cases, the mechanism is established for a period of 2-3 months until the normal physiological outflow of urine is restored.
What is a stent?
Renal stent - a tube up to 30 cm long and 1.5-6 mm in diameter. The implant allows you to remove urine from the kidney into the bladder in cases where the normal outflow is impaired. This happens for a variety of reasons. One end is attached to the kidney itself, the other to the bladder.
An implant is created from special materials that do not cause allergies. If an allergic reaction nevertheless has begun, the stent is urgently removed and an implant made of another material is placed.
Why is a kidney stent needed? Principle of operation
A stent is needed to expand the narrowed ducts, due to adhesions, for example, or with complicated pregnancy. Urine is produced in the kidneys and gradually accumulates in the bladder, passing through the thin tubules - the ureters.
If the ureter does not allow fluid to pass through for some reason, such implants were invented to artificially expand the narrowed sections of the ureter.
Installing a stent in the kidney is sometimes a vital operation. Failure of the kidneys leads to failure of the liver, and without these organs a person dies. If you can save one kidney, a person will depend on hemodialysis for life.
Types of Kidney Tubes
The stent should not be exposed to the destructive action of salts and at the same time be contrasting. It is necessary to control its condition and location. If the tube is shifted or burst, an urgent operation is necessary.
Stents are different in length, made up of various materials; implants also differ in the end of the tubes. Some have folded “tails” on both sides for better fixation, while others have only one side of the implant.
The tube material and its shape are selected individually. The doctor takes into account the patient's age, his general condition and a tendency to allergies. What materials are used? Tubes are usually made of silicone, metal or polyurethane. For a silicone tube, the residence time in the body is up to 8 weeks. More expensive alloys are allowed to be removed after 3-6 months.
Indications and contraindications for installation
The installation of the stent in the kidney is carried out strictly according to medical indications.
Indications in medicine are as follows:
- stenosis (stricture) of the ureter;
- urethrohydronephrosis;
- kidney cancer
- swelling of the ducts due to a prolonged inflammatory process in the bladder;
- narrowing of the ureter due to the growth of the uterus in a woman during pregnancy;
- in men, stenosis occurs due to prostatitis;
- stuck kidney stone in the canal.
After removing a kidney stone, a stent can be placed if sand or smaller stones are still found in the kidneys.
Contraindications are 2 factors: if there is an injury to the urethra or an acute inflammatory process in the small pelvis is diagnosed.
Establishment methods
Currently, obstruction of the urinary duct is not a particularly difficult medical problem. Installation takes half an hour, and most patients do not have complications. How is a stent placed on a kidney?
So, there are 2 installation methods. The first is retrograde, the second is antegrade.
- Retrograde. The implant is inserted through the urethra and bladder. The operation takes between 25-30 minutes. A balloon with a mesh is introduced, in the right place it expands, the mesh as a frame holds the duct walls, and the balloon itself is removed from the body.
- Antegrade. Peritoneal incision is performed. The design is inserted into the kidney through the nephrostomy device, and a catheter attached to the urine collector is placed to remove urine.
After 1-2 months, a new study is being conducted. And the doctor, based on the results of subsequent cystoscopy, makes a decision - to remove the stent or install a new one.
Diagnosis of stenosis
How is narrowing of the renal ducts diagnosed? The patient himself can notice this by signs of stenosis, which, incidentally, cannot be ignored.
Symptoms of duct stenosis:
- temperature rise;
- sharp pains in the lumbar region;
- little urine, it is cloudy;
- sometimes nausea and vomiting appear.
With these symptoms, a stent is required. Kidney surgery is an unpleasant but extremely necessary procedure. Otherwise, hydronephrosis develops.
With hydronephrosis, the symptoms worsen. The temperature is very high, pain during urination, sometimes the patient cannot go to the toilet at all. You need to call an ambulance immediately after the onset of pain (hepatic colic), nausea and headache.
As soon as the doctor checks the history (collected information) and receives the results of an ultrasound of the kidneys, he will be able to give an opinion and schedule an operation to install the stent.
Before the operation, several more mandatory diagnostic procedures are performed:
- MRI of the kidneys;
- Ultrasound
- excretory urography.
During these procedures, it is necessary to establish the degree of narrowing of the ducts, the main cause and some physiological characteristics of the patient. A stent is selected taking into account all the structural features of the ducts, and in different people these physiological features can vary greatly.
How is the operation?
A stent is inserted through the urethra and passes into the renal pelvis. Directly in the kidney tissue, the tube is attached thanks to a special spiral end twisted in the form of a pig's tail.
Through a cystoscope, the doctor finds an abnormally narrowed place in the ureter and a mesh called a balloon is placed there. The mesh expands and the duct is thus reopened.
Depending on the complexity of the situation and the shelf life of the tube itself, the term for removing the implant from the body is set. The operation can be canceled if acute inflammation begins again immediately before installation. Then appropriate antibiotics are prescribed, and the operation is postponed to another time.
Implant during pregnancy
Gestational pyelonephritis may develop in pregnant women due to infection in the urinary tract and double burden on the kidneys. Against the background of pyelonephritis, strictures develop and, accordingly, complications arise, due to which the pregnant woman has to install a stent in the kidney.
Doctors do not recommend a stone removal operation for women in position. Therefore, they put a stent or nephrostomy, and after birth, after about 2 months, the stent is removed.
Complications after installation
In rare cases, complications after stenting are observed. And the patient has to do an emergency operation - replace the tube in the kidneys with a new one. This happens for the following reasons:
- Stent stuck in the ureter.
- The rejection reaction has begun.
- During the operation, an infection got inside the kidney and the inflammatory process began.
- Migration of the stent in the kidney, i.e. displacement due to the tube being loose.
- Tube rupture.
- The formation of many crystals of urine on a silicone tube. Also need to delete.
And also distinguish special, rarer complications. These situations require medical attention urgently.
- The occurrence of an allergic reaction to the stent.
- Swelling of the inner wall of the bladder.
- The appearance of blood clots in the urine.
- If the implant is too rigid, sometimes hematomas appear inside the organs.
To make sure that none of the listed complications is present, the patient is observed in the hospital after installation for 48 hours, then discharged home.
Post-operative stenting
Sometimes an implant is placed during or after surgery. The tube can be installed after reconstructive operations of the pelvic organs, during surgical removal of large stones, or after a kidney transplant. Postoperative edema interferes with the outflow of urine, and stagnation of urine can cause additional inflammation.
The stent in the kidney after surgery is usually removed after a couple of months, during normal cystoscopy. If severe hydronephrosis is diagnosed, the patient may depend on stents for life. Then a suitable alloy is selected and with a certain periodicity is removed and replaced with the same, but new.
General recommendations in the postoperative period. Food restrictions
For a speedy recovery, the patient is advised to strictly follow a diet and drinking regimen. It is forbidden to drink alcohol even in small doses for the duration of the presence of a stent in the kidney.
It is important that vitamins and minerals enter the body, vitamin C is especially important. Fatty foods should be avoided. At the time prescribed by the doctor, you must come for an ultrasound to examine the condition of the ureteric stent in the kidney and the kidney itself. The doctor should examine the organ and make sure that there is no inflammation.
Delete
The first and most important rule - the procedure for removing the stent from the kidney must be done on time. If you skip the date, the material begins to overgrow with salt crystals, it is more difficult and painful to remove it in this form. The procedure is performed under local anesthetic. Children are however removed under general anesthesia.
As with balloon insertion, a cystoscope is inserted through the urethra and a stent is examined. Then the net is poured over with cold water, it narrows and in this form is simply brought out.
The solution to the problem of crystal formation
In 90 percent of people walking with stents in their kidneys, salt crystals completely destroy the skeleton, so often the stent has to be removed even faster than planned. To slow down the process of its corrosion by salts, it is recommended to drink special herbs, herbal remedies.
The tube replacement operation must not be delayed. As soon as the replacement period has come, you should immediately go to the hospital.
Prevention of stenosis and hydronephrosis
It is not yet possible to prevent the occurrence of such kidney problems. Some people are more prone to kidney stones, others do not know what it is. Of great importance is the way of life, its habits and heredity.
In any case, in order to maintain kidney health, it is recommended to regularly perform routine examinations, ultrasound of the pelvic organs - this will not hurt. Drinks such as coffee, alcohol, energy, if drunk excessively, can lead to various diseases of the urinary system, so it is better to limit their use or completely eliminate it.
In pregnant women, kidney problems begin due to reduced immunity. Before planning a pregnancy, it is advisable for women to examine their kidneys. If they are weak, complications may arise during pregnancy.
Prevention of adhesions is the timely diagnosis and measures taken for treatment. Men in order to avoid stenosis need to be checked regularly by a urologist, because prostatitis also leads to inflammation of the urinary tract, and therefore to adhesions.