Penn Pouch
The Penn pouch is an ileocecal continent cutaneous reservoir associated with the Mitrofanoff appendiceal channel. Two published operative case descriptions use the appendix as the catheterizable continence mechanism, with the stoma at the umbilicus in both.[1][2] It belongs to the broader ileocecal pouch family described in the historical imaging literature.[3]
Webster and Bertram described a different reconstruction in seven patients: an intussuscepted ileocecal valve stabilized with a Marlex collar.[4] Cecal segments in that series were usually hyperactive and were controlled with anticholinergic medication.[4]
Reservoir and Channel Design
The ileocecal bowel segment forms the storage reservoir. In the Penn construction described by Simmons and Campbell, 30 cm of right colon and 20 cm of terminal ileum are opened along the antimesenteric border across the ileocecal valve.[9] The ileum is folded into a U-shaped patch, moved anteriorly, and joined to the cecum; the ureters are implanted in the posterolateral pouch wall before closure.[9] 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 |
| 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 |
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, the operative record should list the actual bowel segments, orientation, continence mechanism and implantation sites.
Simmons and Campbell's chapter describes one appendiceal-channel construction sequence: excise the appendix leaving a short cecal cuff, rotate it 180 degrees so the distal tip points caudally, and confirm mesenteric arterial flow after rotation. The distal end is trimmed over a catheter, spatulated, and implanted into an incision in the cecal mucosa; the tunnel is created through an anterior tenia incision with raised muscular flaps closed over the appendix, and the proximal end is brought through the rectus fascia, spatulated, and matured to a V-shaped subumbilical skin flap.[9] In the chapter's postoperative sequence, a temporary cecostomy tube permits irrigation of mucus and clots; a pouchogram at 3–4 weeks checks for extravasation before the cecostomy and stomal catheters are removed and intermittent catheterization begins if no leak is seen.[9]
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. Severe renal or hepatic impairment can preclude a continent bowel reservoir; assess baseline metabolic risk because urine-exposed bowel can add an acid load that limited renal function may not compensate.[9] 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. The case reports describe a reconstruction option for selected children 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.[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 |
| Lowe and Woodside 1990[5] | Five urodynamically assessed patients with an intussuscepted ileocecal valve. Incontinence was minimal, filling and peristaltic pressures were low, nipple pressure exceeded reservoir pressure in 4 of 5, and no reflux was found. One patient leaked when reservoir pressure transiently exceeded nipple pressure at capacity, and this resolved with a shorter catheterization interval. |
| Carroll et al. 1989[6] | Fourteen patients with a plicated terminal-ileal efferent segment, another distinct continence mechanism. Twelve were completely continent, two had mild nocturnal incontinence, mean reservoir volume was 675 mL, and mean reservoir contraction pressure was 24 cm H₂O (maximum 47) |
| Gerharz et al. 1997[7] | Appendix (n = 96) versus intussuscepted ileal nipple (n = 106) in Mainz I reservoirs. Appendico-umbilical stenosis occurred in 15.6% of appendix stomas, and 12.3% of ileal nipples needed a second operation. Stones were removed in 2.8% of ileal-nipple patients and none in the appendix group. |
| Duckett and Lotfi 1993[8] | Mitrofanoff-principle reconstructions with mixed channels in 41 children (appendix 61%, ileum 12%, ureter 27%) and mean follow-up of 3.2 years. Across this cohort, continence was 100% and uncomplicated catheterization 93%; stones formed in 32%, attributed to mucus and bacteriuria. The series used bladder remnants or colon segments |
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] Dosing, irrigation and replacement protocols are in the linked pharmacology pages.
- 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
8. Duckett JW, Lotfi AH. "Appendicovesicostomy (And Variations) in Bladder Reconstruction." J Urol. 1993;149(3):567–9. doi:10.1016/s0022-5347(17)36150-5
9. Simmons MN, Campbell SC. Continent cutaneous urinary diversion: right colonic reservoirs. In: Montague DK, Gill IS, Angermeier KW, Ross JH, eds. Textbook of Reconstructive Urologic Surgery. Informa Healthcare; 2008:375–382.