Intravesical instillation is a medical procedure that involves directly delivering liquid medication into the bladder through a catheter. This localized approach allows the medication to act on the bladder lining, or urothelium, with reduced systemic side effects compared to oral or intravenous treatments.
What Conditions Does It Treat?
Intravesical instillation treats several bladder conditions. Non-muscle invasive bladder cancer (NMIBC), including carcinoma in situ (CIS), is a primary indication. For these cancers, direct instillation helps eradicate remaining cancer cells after surgical removal of tumors or prevent recurrence. It is also used for flat tumors like CIS that are difficult to remove surgically.
The medication can achieve high concentrations directly where it is needed, which is beneficial for drug-resistant conditions.
Interstitial cystitis/bladder pain syndrome (IC/BPS) is another condition treated with intravesical instillation. This chronic bladder disorder involves symptoms like urgency, frequency, and pain, often linked to a damaged protective layer (glycosaminoglycan layer) in the bladder lining. Instillation aims to repair this barrier, reduce inflammation, and alleviate symptoms by directly applying therapeutic agents to the bladder wall.
Radiation cystitis, an inflammation of the bladder lining caused by radiation therapy to the pelvic region, can also be addressed with intravesical treatments. This complication can lead to chronic symptoms, including hematuria (blood in urine). Intravesical agents help manage these symptoms.
The Procedure Explained
The intravesical instillation procedure is typically performed in an outpatient clinic setting. Before the procedure, patients are usually asked to empty their bladder completely. This step ensures that the medication will not be diluted by urine already present in the bladder, allowing for maximum concentration and contact with the bladder lining.
A healthcare provider then carefully inserts a thin, flexible tube called a catheter into the urethra and advances it into the bladder. This process is generally not painful, though some individuals may experience a sensation of fullness or slight discomfort. In some cases, a local anesthetic may be used to enhance comfort during catheter insertion.
Once the catheter is in place, the prescribed medication is slowly introduced into the bladder through the catheter. After the medication has been instilled, the catheter is carefully removed.
The medication is then retained in the bladder for a specific period, typically ranging from one to two hours, though the exact duration can vary depending on the medication and the patient’s treatment plan. Patients are often able to go home after the instillation and continue their normal activities while the medication remains in their bladder. After the designated retention time, the patient voids their bladder to expel the medication.
Medications Used
Various medications are administered through intravesical instillation. For bladder cancer, common agents include chemotherapeutic drugs and immunotherapy agents. Chemotherapeutic agents like Mitomycin C and Gemcitabine work by inhibiting DNA synthesis in cancer cells, aiming to destroy any remaining cancerous cells in the bladder lining. These are often given immediately after a transurethral resection of a bladder tumor (TURBT) to prevent recurrence.
Immunotherapy agents, such as Bacillus Calmette-Guérin (BCG), stimulate the body’s immune system to attack cancer cells. BCG is frequently used for more aggressive non-muscle invasive bladder cancer or carcinoma in situ. It irritates the bladder lining, triggering an immune response that targets cancer cells.
For interstitial cystitis/bladder pain syndrome, different types of agents are employed:
Dimethyl sulfoxide (DMSO) helps reduce bladder irritation, relax bladder muscles, and relieve pain.
Heparin helps restore the protective GAG layer of the bladder lining, which is often compromised in IC/BPS.
Lidocaine, a local anesthetic, is often combined with other agents like heparin to provide immediate pain relief by numbing bladder nerves.
Hyaluronic acid is also used to replenish the GAG layer and may contribute to tissue healing and inflammation reduction.
Managing Side Effects and Expectations
Patients undergoing intravesical instillation may experience a range of side effects. Common side effects include bladder irritation, a burning sensation during urination, increased urgency and frequency of urination, discomfort, and occasionally, light red or pink blood in the urine. These symptoms usually begin within 2 to 4 hours after treatment and generally subside within 48 hours.
To manage these side effects at home, patients are often advised to increase their fluid intake and avoid alcohol and caffeinated beverages. Mild pain relief medication can also help alleviate discomfort. It is important to communicate any severe, unusual, or prolonged symptoms to a healthcare provider, such as:
A fever above 100.5 °F (38 °C)
Shaking chills
Bright red blood or clots in the urine
Flu-like symptoms lasting more than two days
Difficulty urinating
Regarding expectations, a typical treatment course for bladder cancer often involves weekly instillations for six consecutive weeks, followed by potential maintenance treatments that may occur every few weeks or months for up to three years, depending on the patient’s response and cancer recurrence risk. For interstitial cystitis, treatment protocols can also involve weekly instillations followed by less frequent maintenance. Patients should understand that the number of treatments and overall duration will be tailored to their specific condition and response to therapy. Follow-up procedures, such as cystoscopies or bladder biopsies, will be scheduled to monitor the effectiveness of the treatment.