Why a Three-Way Foley Catheter is Called "Tri-Way"
A three-way (tri-way) Foley catheter is named for its three separate internal channels (lumens): one for inflating the retention balloon, one for draining urine from the bladder, and one for continuous bladder irrigation. 1
Anatomical Design and Function
The three-way catheter evolved from Frederick Foley's original 1930s design, which featured a rubber tube with a separate lumen to inflate a balloon that holds the catheter in place within the bladder. 2 The modern three-way version adds a third channel specifically engineered for irrigation purposes. 1
The Three Lumens Serve Distinct Functions:
Balloon inflation port: This smallest lumen allows sterile water (typically 30 mL) to inflate the retention balloon, anchoring the catheter in the bladder 1
Drainage port: This is the largest lumen, designed to allow urine and blood clots to drain from the bladder into the collection bag 1
Irrigation port: This third lumen permits continuous or intermittent instillation of sterile irrigating solution (usually normal saline) into the bladder 1
Clinical Indication for Three-Way Design
Three-way Foley catheters are specifically used when bladder irrigation is anticipated to prevent or manage blood clots in the bladder. 1 This is most commonly needed after transurethral prostate surgery or other urological procedures where significant hematuria is expected.
Performance Characteristics:
Research demonstrates that not all three-way catheters perform equally. The Bardex 22F and 24F catheters showed superior manual irrigation flow rates (8.9-9.5 mL/s) and better continuous irrigation performance (1.6-1.7 mL/s) compared to Dover catheters of the same size. 1 When maximal irrigation is needed, using the drainage port rather than the irrigation port provides significantly higher flow rates (approximately 30 mL/s versus 9 mL/s). 1
Nomenclature Distinction
The term "tri-way" or "three-way" distinguishes this catheter from:
Two-way (standard) Foley catheters: These have only two lumens—one for balloon inflation and one for drainage 2
Single-lumen catheters: Simple drainage tubes without retention balloons 2
The "way" terminology refers to the number of functional pathways or channels within the catheter structure, not the number of external connections (though these typically correspond). 1
Common Clinical Pitfall
A critical error is attempting to use a standard two-way Foley catheter when continuous bladder irrigation is needed. Without the dedicated irrigation port, clinicians cannot simultaneously irrigate and drain the bladder, which is essential for managing significant hematuria and preventing clot retention. 1 Always verify catheter type before procedures where post-operative irrigation is anticipated.