Radiation Injury and Recto-Urethral Fistula

 

What is a radiation injury?

Radiation therapy, alone or in combination with surgery and chemotherapy, is commonly used for the treatment of many cancers. Although radiation therapy can usually be delivered without resulting in long-term injury, it can occasionally lead to permanent side-effects. In severe cases, the radiation leads to scarring (fibrosis) and/or damage to the blood supply of the normal tissues in the irradiated field. It is this scarring and damage that leads to the side-effects seen in patients with radiation injury. When these complications occur, they become apparent 6 months or more after the radiation exposure. In some cases, these complications will occur many years after treatment

What complications can be seen after radiation?

The chance of complications after radiation depends upon the dose and location of radiation treatment, and whether or not it was combined with chemotherapy and/or surgeries in the treated region. Radiation that was given in the abdomen for gynecologic, testicular or pediatric cancers can cause scarring of the kidney or the ureters (the urinary tubes connecting the kidney to the bladder). Radiation that was given in the pelvis for problems like prostate, bladder, colorectal and cervical cancer can also damage the urinary structures. Some of the more common complications from pelvic radiation include strictures of the urethra (about 1 in 20 persons) and urinary urgency and frequency (about 1 in 10). Although often these common complications can be managed with medications, about 1 in 20 persons will require a surgical procedure to repair the damage. In rare cases, a fistula (a hole between the bladder or urethra and the rectum or skin) can occur. Severe complications like fistulas occur in fewer than 1 in 1000 patients who receive modern external beam radiotherapy, but in about 1 in 100 patients who receive high-dose-rate brachytherapy.

How are radiation injuries treated?

The treatment of radiation damage depends upon the nature of the problem. Chronic wounds can sometimes be treated with a trial of hyperbaric oxygen. If there is a surgical problem, this can be addressed by a urologist. Surgery may involve a variety of procedures depending upon the nature of the problem. The damage can be so varied from radiation that each patient will need to have a thorough evaluation to find out the extent of damage and create a strategy to improve or fix the damage that has occurred. This evaluation often involves tests, like CT scans or scope procedures. Once the extent of the problem has been fully assessed, then a surgical strategy can be developed. Having an expert specialty surgeon trained in repairing radiation injuries is required to achieve the best functional outcomes after severe radiation injury.

Fistula

What is a recto-urethral fistula?

A fistula is an abnormal connection between two organs or structures. A recto-urethral fistula is a hole between the urethra (urinary channel) and the rectum. This hole leads to leakage of urine into the rectum and feces traveling into the bladder.

What are some of the causes of a recto-urethral fistula?

The most common cause of a fistula is either pelvic surgery or radiation following treatment of a cancer in the pelvis. Prostate and rectal cancer are common organs of the pelvis to be affected. Fortunately, a recto-urethral fistula is an uncommon complication. The chance of such a condition is <1-2% following surgery or radiation therapy.

How does a patient know when they get a recto-urethral fistula?

The most common sign of a recto-urethral fistula is urine leaking out the rectum. Another sign is recurrent urinary tract infections that involve different types of bacteria. Patients can sometimes become very ill at the time of diagnosis of this fistula.

What happens after the recto-urethral fistula is diagnosed?

It is important to divert the flow of feces away from the urinary tract and treat infections when a recto-urethral fistula is first diagnosed. The way the feces are diverted is a colostomy. In this surgery the colon or small bowel is brought up to the skin and sewn in place. A stoma bag is pasted to the skin to collect the feces. The colostomy is a temporary measure until the recto-urethral fistula can be repaired. Often patients need to wait between the colostomy placement and the fistula repair for a couple of months to allow inflammation from the fistula to improve. Rarely, the fistula will heal spontaneously with only the colostomy surgery.

How are recto-urethral fistula treated?

The treatment of a recto-urethral fistula is not easy. Each fistula is different and needs to be fully evaluated. Most fistulas can be treated by closure of the fistula and placement of a muscle flap from the leg between the rectum and the urethra. This muscle flap is essential to allow for healthy healing of this area. During surgery, the hole in the rectum and urethral are separately repaired. The colo-rectal surgeon and urologist operate together to accomplish the repair. A reconstructive urologist should be involved who is skilled in various methods to repair the urethra.

Is recovery from surgery difficult?

Hospitalization after surgery is usually 3-5 days depending on the type of repair. Given the complexity of the repair, the urinary catheter will remain in place 4-6 weeks after surgery. After the surgery is deemed successful, the colostomy can be reversed. This time frame is usually about 3-6 months after removal of all the urinary catheters. There may be some urinary incontinence related to the repair of the recto-urethral fistula. If this is an issue, additional surgery may be necessary. Surgery to manage the incontinence will usually occur 3 months after the colostomy is reversed.

Figure: A pre-operative X-ray of large recto-urethral fistula located between the rectum and the prostate related to treatment for prostate cancer.

Figure: The post operative X-ray, in the same patient, after reapir of the recto-urethral fistula.  The X-ray shows elimination of the connection between the urethra and the rectum. 

Radiation Cystitis

Occasionally, radiation to the pelvic structures such as the prostate can damage the bladder.  The symptoms are variable and range from urinary urgency, involuntary leakage of urine, and blood in the urine.  Initial options for treatment are medications and scope procedures of the bladder (cystoscopy). If the symptoms cannot be controlled with these measures, urinary diversion (hyperlink http://www.turnsresearch.org/library-article/slug-x3ojqu) can occasionally be required.  Radiation cystitis may occur with or without urinary fistula.