Radiotherapy-Induced Stricture Formation
Diagnostic Approach
Most patients with symptoms after pelvic or abdominal radiotherapy require appropriate investigation before treatment, as symptoms are unreliable at predicting the underlying cause and inappropriate treatment carries significant potential for harm. 1
Initial Evaluation
Contact the treating oncologists and surgeons for precise details of previous radiation treatments, as this information frequently changes management and helps determine radiation dose to specific anatomic structures 1
Recognize that gastrointestinal or urinary symptoms starting after cancer treatment are frequently unrelated to the radiation itself, and many patients have multiple concurrent causes for their symptoms 1
Gastrointestinal Strictures
Patients with rectal bleeding or obstructive symptoms require endoscopic evaluation (at minimum flexible sigmoidoscopy) because of the high prevalence of unexpected pathology including new malignancy, infection, or other non-radiation causes 1
Do not perform biopsy for diagnosis of radiation proctopathy when the typical appearance is present, as the diagnosis should be based on endoscopic appearance alone 1
For suspected small bowel strictures causing diarrhea or obstructive symptoms, investigate for concurrent bile acid malabsorption, small bowel bacterial overgrowth, and pancreatic insufficiency, as these frequently coexist and contribute to symptoms 1
Urinary Strictures
Ureteral strictures most commonly affect the distal ureter and present with hydronephrosis, which was the most frequent finding in radiation-damaged urinary tracts 1, 2
Delaying clearance of ureteral obstruction increases risk of serious long-term morbidity including infections, kidney damage, and arterial hypertension 1
The risk of ureteral stricture in patients with locally advanced cervical cancer and hydronephrosis at diagnosis was 11.5% at 5 years compared to 4.8% without baseline hydronephrosis 1
Urethral strictures after prostate radiation occur most commonly at the bulbomembranous urethra, with diagnostic workup requiring uroflowmetry, urethroscopy, retrograde urethrogram, and voiding cystourethrography 3, 4
Chronic urinary symptoms from vascular endothelial cell damage develop with a latency period of 1 to 25 years, explaining why strictures can emerge decades after treatment 1
Treatment Approach
Gastrointestinal Strictures
Endoscopic balloon dilation with intralesional triamcinolone injection is the preferred initial treatment for benign rectal strictures, as it has high success rates with very low complication rates and avoids the high morbidity and mortality of surgical approaches. 5
Critical Safety Considerations
Radiation-induced bleeding and strictures are ischemic problems in chronically damaged tissue; interventions may not heal and can lead to necrosis, perforation, deep ulceration, fistulation, and severe chronic pain 1
Argon plasma coagulation should be used with extreme caution, as the serious complication rate can be as high as 26% when used for radiation proctopathy, despite many gastroenterologists considering it first-line therapy 1
Patients must provide signed informed consent after being informed of specific risks including perforation, fistulation, and necrosis before any endoscopic intervention in irradiated tissue 1
Specific Treatment Options
For esophageal strictures, careful endoscopic dilatation by cautiously increasing dilator size over multiple procedures achieves success in >80% of cases after an average of two dilatations 6
For resistant strictures, intralesional steroids may be helpful but require individualized careful approach 6
Avoid expandable metal stents except in fistula or palliative settings; biodegradable or removable stents are preferred if stenting is necessary 6
Surgical intervention leading to colostomy or exenteration is reserved for refractory cases that fail endoscopic management 1
Urinary Strictures
For radiation-induced urethral strictures, urethroplasty is the most definitive and durable treatment modality, as failure rates for dilation and direct-vision internal urethrotomy are exceedingly high. 4
Urethral Stricture Management
Primary end-to-end anastomosis achieves success rates of 70-95% for short urethral strictures, with incontinence rates of 7-40% 3
Buccal mucosa graft urethroplasty is indicated for longer, more complex strictures, with success rates of 71-78% but postoperative incontinence in 10.5-44% of cases 3
Postoperative incontinence can usually be successfully treated with artificial urinary sphincter 3
Patients must be counseled regarding stricture length, location, and the significant risk of postoperative incontinence before proceeding with urethroplasty 3
Ureteral Stricture Management
The incidence of severe radiation-induced ureteral stenosis increases continuously at approximately 0.15% per year, reaching 2.5% at 20 years 7
During the first 5 years after treatment, tumor recurrence is the most common cause of ureteral stricture and must be excluded before attributing obstruction to radiation injury 7
Patients who received centrally blocked external fields or more than two transvaginal radiation treatments are at increased risk for ureteral stenosis 7
Bilateral ureteral stricture can be fatal, with four deaths reported in one series, emphasizing the importance of early intervention 7
Common Pitfalls
Assuming symptoms are radiation-related without investigation can lead to missed diagnoses of recurrent malignancy, infection, or other treatable conditions 1
Using thermal therapies like argon plasma coagulation without understanding the 26% serious complication rate in ischemic irradiated tissue 1
Failing to investigate for concurrent conditions (bile acid malabsorption, bacterial overgrowth, pancreatic insufficiency) that frequently coexist with radiation strictures 1
Delaying intervention for ureteral obstruction, which increases risk of permanent kidney damage and hypertension 1
Radiation injury to ureters may not become apparent for many years, necessitating continued vigilance throughout patients' lives 7