Penn Pouch
The Penn pouch is an ileocecal continent cutaneous reservoir associated with the Mitrofanoff appendiceal channel. Published operative case descriptions explicitly use the appendix as the catheterizable continence mechanism, usually opening at the umbilicus.[1][2] It belongs to the broader ileocecal pouch family described in the historical imaging literature.[3]
An intussuscepted ileocecal valve reinforced with a Marlex collar is a different described reconstruction. Webster and Bertram's seven-patient report used that mechanism; it must not be relabeled as the defining Penn operation or used to supply Penn-specific outcome rates.[4]
Reservoir and Channel Design
The ileocecal bowel segment forms the storage reservoir. A vascularized appendix provides a narrow catheterizable channel, with a tunneled flap-valve relationship to the reservoir wall. In the published Penn cases, the appendix was reversed and its cecal end brought to the umbilicus. Ureteral implantation and the appendiceal tunnel are separate structures.[1][2]
| Structure | Purpose | Operative consideration |
|---|---|---|
| Ileocecal reservoir | Urinary storage | Preserve the bowel's vascular supply and create adequate capacity and compliance; a named pouch does not guarantee low storage pressure |
| Appendiceal channel | Continent access for intermittent catheterization | Preserve the appendiceal mesentery, ensure sufficient reach and an accessible stoma, and avoid a tight or angulated tunnel |
| Ureteral implantation | Drainage of the upper urinary tract into the reservoir | Maintain perfusion and a tension-free course; evaluate for obstruction during follow-up |
| Cutaneous stoma | Repeated catheter access | Site according to abdominal contour, reach and ability to catheterize; the umbilicus is an option, not an obligation |
For detailed channel construction and alternatives when the appendix is absent or unsuitable, see Principles of Continent Catheterizable Channels. If the reservoir or channel is modified, record the actual bowel segments, orientation, continence mechanism and implantation sites rather than relying on the pouch name alone.
Selection
This diversion requires reliable lifelong intermittent catheterization and follow-up. Selection depends on renal function, bowel suitability, reservoir requirements, channel reach, dexterity or dependable catheterization assistance, and the patient's preferences. Pediatric reconstruction also needs a plan for growth, transition and independent self-care where possible.
The published Penn case reports describe selected children with severe congenital urinary anomalies. They illustrate an available reconstruction; they do not establish a preferred diversion for every child with a small or absent bladder.[1][2] See Urinary Diversion Principles for the wider choice between conduit, cutaneous reservoir and other reconstruction.
Evidence and Outcomes
Dedicated Penn evidence is limited. Two accessible operative case reports describe successful catheterization and continence during approximately four years of follow-up, but individual successes cannot estimate a population's complication risk or demonstrate superiority.[1][2]
The following sources describe related operations, and their denominators should remain separate:
| Source | What was actually studied |
|---|---|
| Webster and Bertram 1986[4] | Seven patients with a stapled intussuscepted ileocecal valve, including three augmentations and four bladder replacements; this is not evidence for appendiceal Penn-channel outcomes |
| Lowe and Woodside 1990[5] | Five urodynamically assessed patients with an intussuscepted ileocecal valve; their reservoir and nipple pressures do not describe an appendiceal channel |
| Carroll et al. 1989[6] | Fourteen patients with a plicated terminal-ileal efferent segment, another distinct continence mechanism |
| Gerharz et al. 1997[7] | Appendix versus ileal-nipple mechanisms in Mainz I reservoirs; these are not Penn-specific revision rates |
Long-term Care
Maintain a regular, individualized catheterization schedule and teach recognition of difficult access, leakage and incomplete emptying. Do not force a catheter through a resistant channel; inability to drain a full reservoir requires prompt specialist assessment. Reservoir overdistension, channel stenosis, stones, mucus obstruction, urinary infection and perforation remain possible despite initially good continence.
Monitor renal function, electrolytes and bicarbonate, upper-tract imaging, and nutritional consequences according to the bowel segments and renal reserve. Ileal resection can affect vitamin B12 handling; colonic and ileal urine exposure can cause metabolic acidosis. One Penn case report explicitly described mild persistent acidosis despite stable renal function.[1] Drug dosing, irrigation and replacement protocols belong in the linked pharmacology guidance rather than being inferred from a single case.
- Mucus management
- Vitamin B12 supplementation
- Urinary acidifiers and alkalinizers
- Indiana pouch
- Mainz pouch I
References
1. Khemchandani SI. Triad of bladder agenesis with solitary kidney and ectopic ureter. Indian J Urol. 2008;24:566–568. doi:10.4103/0970-1591.44271.
2. Khemchandani SI. Continent cutaneous diversion and external genitalia reconstruction in a child with severe variety urogenital sinus and ambiguous genitalia. J Indian Assoc Pediatr Surg. 2015;20:84–86. doi:10.4103/0971-9261.151554.
3. Amis ES, Newhouse JH, Olsson CA. "Continent Urinary Diversions: Review of Current Surgical Procedures and Radiologic Imaging." Radiology. 1988;168(2):395–401. doi:10.1148/radiology.168.2.3293109
4. Webster GD, Bertram RA. "Continent Catheterizable Urinary Diversion Using the Ileocecal Segment With Stapled Intussusception of the Ileocecal Valve." J Urol. 1986;135(3):465–9. doi:10.1016/s0022-5347(17)45693-x
5. Lowe BA, Woodside JR. "Urodynamic Evaluation of Patients With Continent Urinary Diversion Using Cecal Reservoir and Intussuscepted Ileocecal Valve." Urology. 1990;35(6):544–7. doi:10.1016/0090-4295(90)80114-3
6. Carroll PR, Presti JC, McAninch JW, Tanagho EA. "Functional Characteristics of the Continent Ileocecal Urinary Reservoir: Mechanisms of Urinary Continence." J Urol. 1989;142(4):1032–6. doi:10.1016/s0022-5347(17)38979-6
7. Gerharz EW, Köhl U, Weingärtner K, et al. "Complications Related to Different Continence Mechanisms in Ileocecal Reservoirs." J Urol. 1997;158(5):1709–13. doi:10.1016/s0022-5347(01)64105-3