Introduction
In individuals with defective or obstructed ureters, a catheter is used as a stent to help the urine flow back from the kidney to the bladder and reestablish normal kidney function. The retrograde nephroureteral stent moves backward to the renal pelvis, and the antegrade nephroureteral stent moves forward. The internal double J stent has curved edges preventing it from falling into the kidneys or urinary bladder. A retrograde nephroureteral stent (RNUS), in short, means a catheter that is placed in patients who undergo surgical treatment, like cystectomy with ileal conduit formation in which it exits from the conduit and extends retrogradely to the renal pelvis. It is necessary to understand the anatomy of patients with incontinent urinary diversion for patients suffering from urinary bladder cancer or other conditions of dysfunctional or nonfunctioning urinary bladders. Treatment success of ureteric strictures and following hydronephrosis by percutaneous methods can achieve a maximum of up to 100 percent.
What Is a Stent?
The stent is a soft, elastic, hollow tube and an operator is used to allow fluid flow without obstruction. They are made of mesh, silicone, or a combination of materials. They can be placed in various body parts like the heart, lungs, and kidneys where a blockage can be seen, which does not allow the fluid to flow.
What Is Nephroureteral Stent?
The stent that helps restore urine flow in the blocked ureters and retains normal kidney function is a nephroureteral stent. The ureter is a part of the kidney's anatomy, a thin tube-like structure connecting the kidneys to the urinary bladder. The ureters get blocked in some diseases and conditions like malignancies related to the urinary bladder, kidney stones, calculi, etc. A stent is mandatory in such cases to make the ureters function again. The ureteral stents are thin and flexible tubes that open the obstructed ureter. An interventional radiologist performs the stenting. There are three types such as antegrade, retrograde, and internal (JJ) nephroureteral stents.
What Is Retrograde Nephroureteral Stent?
Retrograde nephroureteral stent (RNUS) is a catheter placed in patients who underwent surgery like a cystectomy with ileal conduit formation. In which the stent exits from the conduit and extends backward to the renal pelvis. Sometimes complications of a cystectomy occur, for example, ureteral obstruction after radical cystectomy. So the retrograde nephroureteral stent is placed in the patient. It is a minimally invasive procedure. In the case of urinary bladder cancer or a dysfunctional urinary bladder, it becomes really important to know the anatomy of the bladder well to place the stent. The RNUS or retrograde nephroureteral stent is placed in patients with urinary diversion suffering from ureteric leaks and fistula, such as ureteric or anastomotic strictures. In some cases, an antegrade nephroureteral stent is also done; this procedure is opposite to a retrograde nephroureteral stent.
Why Does One Need Retrograde Nephroureteral Stent?
Retrograde nephroureteral stents can be used in various ways and for various reasons. When there is sharp pain due to renal colic or stones, this stent can be placed, and the pain can be reduced. When there is an infection present, the nephroureteral stent facilitates drainage. Also, this stent is considered a solution when a stone prohibits the kidney from functioning properly. When any surgical procedure is done in the kidney, for example, ureteroscopy, the stent encourages healing and ensures smooth drainage of the urine post-procedure.
How Is the Retrograde Nephroureteral Stenting Done?
It is a minimally invasive surgical procedure. It is generally used for the proper drainage of fluids from the renal pelvis. Nowadays, polyurethane and silicone are the material of primary choice for stenting. The patient is administered general anesthesia intravenously. Sometimes, the procedure is performed under local anesthesia with or without sedation. Usually, the interventional radiologist then performs the procedure. At the time of the procedure, a tube attached to a tiny optic camera is inserted via the urethra into the urinary bladder. After the insertion of the optic camera, the urinary bladder is examined properly, and the opening of the ureters is located. The radiographic images are taken with the contrast dye agent in the urinary tract to find the obstruction. Then the stent is placed via a guidewire in the ureter.
What to Expect After the Stenting Is Done?
As the patient's urinary tract is invaded through a few instruments, the patient may feel discomfort after the procedure. The patient may also feel a few symptoms mentioned below:
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Burning sensation while urinating.
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Low-graded hematuria.
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An unusual discomfort in the bladder or the lower abdominal area.
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Frequent urge to urinate.
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Pain due to unhealed underlying tissue may take time to heal.
When Should Someone Seek Help Following a Retrograde Nephroureteral Stenting?
If the symptoms worsen or do not go away even after the primary healing period, medical help should be sought. Also, when the fever rises above 100.4 degrees Fahrenheit, the physician should be contacted. When the pain while urinating worsens or becomes unbearable after a point, the patient should be rushed to the medical facility. Sometimes, a person cannot urinate, which may denote an underlying infection. Also, the pain at the site of the procedure does not subside even after taking the pain medications. When the patient sees a large amount of blood in the urine, it does not stop for long. In all these cases, the situation should be considered a medical emergency. The physician and the hospital staff will advise you on day-to-day activities. The patients have to look after themselves for a few weeks till the inner tissue is healed properly. Lifting weights should be avoided, and strenuous activities should also be avoided. One should not get involved in sexual activities to avoid infection. Allow the body to be rested properly for the first few weeks.
Conclusion
The retrograde nephroureteral stent is a useful and safe method for fluid flow uninterrupted. It has many successful results and has provided solutions in many cases of ureteral obstruction. Currently, stents in the urinary tract are used in both benign and malignant conditions. The safety and assurance of this procedure are very well documented. The procedure takes care of the ureteral obstruction by itself. Further studies and research are needed for more development in this area.
