Lateral Abdominal X-Ray View
To confirm peritoneal dialysis catheter tip position in the rectovesical (male) or rectouterine (female) space, obtain both lateral and anteroposterior (AP) plain X-ray films of the abdomen and pelvis.
Recommended Imaging Protocol
The lateral view is essential because it provides the depth perspective needed to confirm the catheter tip is positioned in the most dependent portion of the pelvis—the rectovesical or rectouterine pouch 1. The AP view alone cannot adequately assess anterior-posterior positioning within the pelvis.
Why Both Views Are Necessary
- Lateral view: Shows whether the catheter tip has descended into the deep pelvic space (rectovesical/rectouterine pouch) versus being positioned more anteriorly or superiorly
- AP view: Demonstrates side-to-side positioning and helps identify lateral malposition or migration
The biplanar approach (both lateral and AP views) is the standard recommendation for evaluating peritoneal dialysis catheter position 1. This dual-view technique allows detection of the catheter's three-dimensional location and identifies common malpositions including high placement in the superior pelvis, lateral deviation, or anterior positioning against the bladder wall.
Clinical Context and Caveats
Important consideration: While ideal catheter tip position in the small pelvis correlates with better function, research shows that 40-48% of well-functioning catheters are actually malpositioned on imaging 2, 3. The positive predictive value of X-ray for catheter dysfunction is only 26%, though the negative predictive value is 87% 2.
What This Means for Practice
- A catheter tip NOT in the ideal pelvic position doesn't automatically mean dysfunction will occur
- Many "malpositioned" catheters function normally
- X-ray confirmation is most useful when there are actual drainage or infusion problems, not routinely for asymptomatic patients
Optimal Timing
Obtain the X-ray after catheter insertion to document baseline position 4. If catheter dysfunction develops later (poor drainage, difficulty with infusion), repeat imaging with both views to assess for migration 5.
The rectovesical/rectouterine space represents the most gravity-dependent area in the supine position, which is why this location is targeted 6. However, fluoroscopic guidance during insertion can reduce late catheter dysfunction from 11.65% to 3.6% by ensuring proper initial placement 5, 7.