Straight Catheterization in Patients with Urostomy
Straight catheterization cannot be performed through the native urethra in a patient with a urostomy (ileal conduit), as the bladder has been removed or bypassed; however, catheterization of the urostomy stoma itself is possible and sometimes necessary for specific clinical indications. 1
Understanding the Anatomy
A urostomy (ileal conduit) involves surgical diversion of urine to an external collection appliance through a segment of bowel brought to the abdominal wall, meaning there is no functional bladder or urethral pathway for traditional catheterization. 2, 1
The ureters are implanted into an isolated bowel segment (typically ileum) that drains through an abdominal stoma, fundamentally altering the urinary tract anatomy. 2, 1
When Catheterization of the Stoma May Be Indicated
Ureteral stents placed at the time of surgery may require assessment or manipulation through the stoma opening, particularly if there are concerns about upper tract drainage or stent migration. 1
Diagnostic procedures such as loopography (contrast study of the conduit) require catheterization of the stoma to evaluate for complications like stricture, reflux, or anastomotic issues. 2
If the stoma becomes stenotic or partially obstructed, gentle catheterization may be attempted as a temporizing measure, though definitive surgical revision is typically required. 3
Critical Technical Considerations
Catheterization of an ileal conduit stoma requires specialized technique using small-caliber catheters (typically 10-14 Fr) and gentle advancement to avoid trauma to the bowel mucosa or ureteral anastomoses. 4
The catheter should be advanced only 2-4 cm into the conduit to avoid traumatizing the ureteroileal anastomoses, which are typically located within the conduit. 4
Mucus production from the bowel segment is normal and expected, and catheters may become obstructed with mucus, requiring irrigation with normal saline. 4
Important Pitfalls to Avoid
Never attempt to catheterize the native urethra in a patient who has undergone cystectomy with ileal conduit, as the bladder has been removed and this will cause urethral trauma without achieving urinary drainage. 2
Avoid forceful advancement of catheters through the stoma, as this can cause perforation of the bowel segment or disruption of the ureteroileal anastomosis. 4
Do not confuse a urostomy with a continent catheterizable pouch (such as an Indiana pouch or Kock pouch), which is designed for regular catheterization but represents a different surgical construction. 5
Alternative Approaches for Upper Tract Access
If upper tract decompression is needed and retrograde access through the stoma is unsuccessful, percutaneous nephrostomy (PCN) is the preferred alternative, with technical success rates approaching 100% for dilated systems. 2
Retrograde ureteral stenting through an ileal conduit is technically challenging due to difficulty visualizing ureteric openings and navigating the bowel anatomy, with limited success rates reported. 2
Antegrade percutaneous nephroureterostomy (PCNU) is generally preferred over retrograde approaches in patients with urinary diversion, as it avoids the technical challenges of working through the conduit. 2