Table of Contents
Introduction
Incontinence is the involuntary leakage of urine that affects millions of people globally. It may have a significant impact on one's quality of life, affecting one's mental and physical health. There are many ways to treat stress urine incontinence (SUI); injectable bulking agents are less invasive. This therapy involves injecting material into the urethra ( the tube that carries urine out of the body) to help control urinary leakage, called stress urinary incontinence. These materials can be synthetic substances, bovine (cow) collagen, or a substance taken from the patient's body. However, this method is less commonly used compared to surgical options. This article explains the role of injectable bulking agents in the treatment of incontinence.
What Is Stress Urinary Incontinence?
Urinary leakage that occurs during physical activity that raises abdominal pressure, such as laughing, sneezing, coughing, or exercising, is known as stress urinary incontinence (SUI). It is the most common form of urine incontinence in women.
SUI occurs when the pelvic tissues and muscles that support the bladder and urethra weaken. This weakening can cause the bladder neck ( where the bladder and urethra connect) to descend during physical activity such as coughing, sneezing, or exercise. As a result, the Urethra does not work properly to control the urine flow.
Also, the weak urethral sphincter muscle can contribute to stress urinary incontinence. Under normal conditions and when abdominal pressure rises, the weaker sphincter muscle cannot stop urine flow. Factors that can weaken these muscles include pregnancy, childbirth, menopause, aging, and previous pelvic surgery. Other risk factors include chronic coughing, straining for an extended period, obesity, and smoking.
What Are Injectable Bulking Agents?
Injectable bulking agents are used to treat stress urinary incontinence. This procedure involves injecting a substance (a working agent) into the urethra to thicken its wall. The goal is to strengthen the urethra or bladder neck to help control urine leakage.
Procedure:
During this procedure, the patient is positioned on their back with their legs raised and supported.
Local anesthesia is used to clean and number the area. A two-percent lidocaine gel is used to numb the urethra. If more anesthesia is needed, an injection of one percent lidocaine may be given. The bulking agent is injected through the skin, the urethra, or the vagina. A special needle is used to inject a bulking agent into the urethra. A cystoscope, a narrow illuminated tube with a camera at the end, guides needle insertion into the urethra.
Types of Injectable Bulking Agents
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Bovine Collagen: It is derived from cattle and injected around the urethra to improve its function. The collagen causes the surrounding tissue to bulk up. This helps to close the urethral opening, which helps maintain incontinence by preventing involuntary urine leakage. A patient needs a skin test for allergies before the procedure.
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Calcium Hydroxylapatite: A calcium hydroxylapatite particle is combined with sodium carboxymethyl cellulose, which serves as a carrier. Once injected, the sodium carboxymethylcellulose breaks down and is absorbed by the body. Calcium hydroxyapatite particles remain in the area. These particles stimulate tissue growth and new collagen formation, improving incontinence.
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Carbon Bead Particles: Carbon bead particles do not break down over time. They stay in place longer and maintain their bulking effect. They are as effective as collagen for treating urinary incontinence.
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Polydimethylsiloxane: Polydimethylsiloxane is a non-biodegradable type of silicon that remains in the body permanently once injected. It is known for its durability and generally provides a long-lasting effect compared to collagen.
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Autologous Fat: Autologous fat refers to fat taken from the patient's lower abdomen. It is an excellent bulking agent because it is affordable, easily accessible, and nonallergenic. However, it is less effective than bulking agents like collagen or Polydimethylsiloxane.
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Polytetrafluoroethylene Paste: Polytetrafluoroethylene paste is no longer used to treat urinary incontinence due to serious risks. The polytetrafluoroethylene particles could move from the urethra to other body parts, including the lungs, lymph nodes, and brain. The body treats it as a foreign object. Polytetrafluoroethylene leads to foreign body reactions and the formation of granulomas.
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Ethylene Vinyl Alcohol: The use of Ethylene Vinyl Alcohol is no longer recommended because of the severe complications. Patients who receive injections experience serious problems, including a damaged urethra (erosion).
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Dextranomer or Hyaluronic Copolymer: It is no longer used because of the risk of abscess formation after the injection.
Long-Term Monitoring:
Pain after the procedure is usually minimal, so additional pain medications are needed. A follow-up after 24 hours is needed to check for urinary retention. If any retention occurs, patients are instructed to perform clean intermittent catheterization. Follow-up appointments are scheduled at three, six, and 12 months after the procedure.
What Are the Complications of Injectable Bulking Agents?
Temporary urinary retentions are the most common complication and occur due to urethral edema (swelling around the urethra), urethral sphincter spasm (involuntary contractions of the urethral sphincter), or over-injection of a bulking agent. Temporary urinary retention is self-limiting and is treated by self-catheterization.
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Complications of Bovine Collagen and Carbon Bead Injection: The most common complications of collagen and carbon bead injections include urinary tract infections, temporary urinary retention, and transient urethral irritation.
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Other uncommon complications include periurethral pseudocyst (a fluid-filled cyst near the urethra) and urethrovaginal fistula (an abnormal connection between the urethra and vagina).
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Complications of Calcium Hydroxylapatite Injection: These are similar to those of collagen and carbon bead injection, but there is a chance of developing urge incontinence (frequent and urgent need to urinate) and foreign body granuloma in some cases.
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Complications of Polydimethylsiloxane Injection: Complications are similar to collisions, carbon beats, and calcium hydroxylapatite injection, but no long-term severe problems have been reported.
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Complications of Autologous Fat Injection: Temporary urinary retention is the most common postoperative problem after autologous fat injection. Due to the resorption of fat, there is a risk of recurrent urinary incontinence. Pain in the abdomen at liposuction sites can also occur. A rare but serious complication is fat embolization (where fat blocks blood vessels), which can be fatal.
Conclusion
Injectable bulking agents are less invasive options for treating stress urinary incontinence. These injectables help strengthen the urethral wall to prevent involuntary leakage. Each type of bulking agent provides a varied degree of efficacy and potential complications. While effective for many, these treatments can lead to complications such as temporary urinary retention and other complications. Healthcare providers can effectively use banking agents as an available tool for managing SUI.
