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Kock Pouch

The Kock pouch is a detubularized, low-pressure continent ileal reservoir featuring intussuscepted nipple valves for both continence and antireflux protection, originally conceived by Nils Kock at the University of Gothenburg in 1969 for fecal diversion and adapted for urinary diversion in 1975.[1][2][3][4][5][6] It was subsequently championed and extensively modified by Donald G. Skinner at USC, becoming the largest single-center continent urinary diversion experience in the world (802+ patients by 1992). The Kock pouch is historically the most important continent urinary diversion: it established the fundamental principles — detubularization, low-pressure reservoir, and continent valve mechanisms — upon which virtually all subsequent continent diversions and orthotopic neobladders were built.

Historical Development​

Nils Kock and the Origin of the Continent Reservoir​

  • 1969 — Nils Kock first described the continent ileostomy (K-pouch) for fecal diversion after proctocolectomy in ulcerative colitis.[5][6]
  • 1969–1975 — Kock progressively added the intussuscepted nipple valve, the breakthrough that made continent diversion possible.[6][7]
  • 1975 — Kock adapted the reservoir for urinary diversion, adding a second intussuscepted nipple valve (afferent) to prevent vesicoureteral reflux.[3]

The USC / Skinner Era​

  • 1982 — Skinner began performing the Kock pouch at USC, introducing mesenteric stripping to allow adequate intussusception, staple fixation, and a Marlex (polypropylene) collar to prevent dessusception (later abandoned).[2]
  • 1984 — Skinner's first 51-patient USC series: 49/50 continent, capacities up to 1,400 mL, 1 reflux.[2]
  • 1987 — 250-patient USC series: 16% early complications, 2% mortality, 31% late complications, 85 revisions in 77 patients.[1]
  • 1986 — Skinner adapted the Kock reservoir for orthotopic lower urinary tract reconstruction (urethral Kock pouch) in 39 highly selected men.[4]
  • 1988 — 531-patient USC series: 16.2% early complications, 1.9% mortality, 22% late complications post-1985.[4]
  • 1992 — 802-patient USC series analyzed for afferent nipple valve complications.[8]
  • 1996 — Elmajian, Stein, and Skinner published the 295-patient orthotopic Kock ileal neobladder series.[9]

The Mansoura Urethral Kock Pouch (Ghoneim)​

  • 1987 — Ghoneim, Kock, Lycke, and Abol-Enein at Mansoura published the first urethral Kock pouch (n = 16) — a single antireflux intussusception valve with the native sphincter providing continence.[10]
  • 1989 — 43-patient series: 88% day/night continence, but 42% reflux from valve eversion or sliding.[11]
  • 1992 — 185-patient series: 92% daytime / 73% nighttime continence; 90% upper-tract stability or improvement.[12]

Copenhagen Long-Term Series and Evolution to T-Pouch​

  • 2000 — Steven and Poulsen (Copenhagen) published the 166-patient orthotopic Kock neobladder series with the most detailed long-term urodynamic data: 97–100% daytime / 75–94% nighttime continence at 1–5 yr; 5-year stone risk 34%; 5-year B12 deficiency 33%.[13]
  • 1998 — John P. Stein (Skinner's protégé at USC) introduced the T-pouch, replacing the intussuscepted afferent nipple with a serous-lined ileal tunnel (inspired by the Mansoura SLET).[14]

Design Principles​

The Kock pouch established the fundamental principles that underpin all modern continent urinary diversions and orthotopic neobladders.[1][3][4]

  1. Detubularization — opening the ileal segment along the antimesenteric border disrupts coordinated peristalsis, creating a low-pressure reservoir.
  2. Spherical reconfiguration — folding the detubularized plate maximizes volume while minimizing pressure (Laplace's law).
  3. Intussuscepted efferent nipple valve — a one-way continence valve that protrudes into the reservoir; rising intraluminal pressure compresses it, preventing spontaneous emptying.
  4. Intussuscepted afferent nipple valve — a second valve on the ureteral side prevents reflux.
  5. Self-catheterization — the reservoir is emptied by CIC every 4–6 hours, eliminating the external appliance.[1][2][3]

Surgical Technique​

Original Kock Pouch — Continent Cutaneous Diversion​

  1. Bowel isolation — approximately 60–80 cm of distal ileum is isolated 15–25 cm proximal to the ileocecal valve, divided into five limbs: two for the reservoir body, one each for afferent and efferent nipple valves, and one for the stoma.[1][2]
  2. Ileoileal anastomosis restores GI continuity.
  3. Detubularization — the two central limbs (~22 cm each) are opened along the antimesenteric border and folded into a U-shape to form the reservoir body.
  4. Afferent nipple valve — the proximal limb (~12 cm) is intussuscepted into the reservoir. A mesenteric window is created to allow adequate intussusception. The valve is secured with metallic staples through the full thickness of the intussuscepted bowel wall. In the Skinner modification, a Marlex collar wrapped the base (later abandoned due to erosion).[2][15]
  5. Efferent nipple valve — the distal limb (~12 cm) is similarly intussuscepted and stapled — the continence valve.
  6. Ureteral reimplantation — both ureters are anastomosed to the afferent limb proximal to the nipple valve (end-to-side or Bricker).
  7. Stoma — the distal end of the efferent limb is brought through the abdominal wall as a flush, catheterizable stoma.
  8. Reservoir closure — running absorbable sutures.

Urethral Kock Pouch — Orthotopic Modification​

The orthotopic version eliminates the efferent nipple valve and stoma.[9][10][11][12]

  1. The reservoir is constructed identically with only one intussuscepted nipple valve (afferent, antireflux).
  2. The most dependent portion is anastomosed directly to the membranous urethra.
  3. The native external urethral sphincter provides continence.
  4. Voiding occurs by Valsalva combined with pelvic-floor relaxation.

Skinner Modifications (1982–1985)​

  • Mesenteric stripping — narrow strip removal for 8 cm along afferent and efferent limbs to allow adequate intussusception depth.[2]
  • Marlex collar — polypropylene mesh wrapped around the nipple base (later abandoned due to erosion and stone formation).[1][15]
  • Staple fixation — multiple rows of metallic staples through the intussuscepted bowel wall.
  • Fascial sling — later modification using autologous fascia instead of Marlex.

Functional Outcomes​

Continent Cutaneous Kock Pouch​

SeriesnContinenceCapacityNotes
Gerber 1983[3]7100%—First US experience
Skinner / USC 1984[2]5198%up to 1,400 mLInitial series
Skinner / USC 1987[1]250~95%High31% late complications; 2% mortality
Skinner / USC 1988[4]531>95%High22% late complications post-1985; 1.9% mortality
Chen / Taiwan 1990[16]5384.8%Mean 332 mL7.6% nipple prolapse
Henriet / France 1991[17]7294.2%—26.1% late complications (Kock-Skinner)
Arai / Japan 1993[18]76Satisfactory—22.1% revision; 26.5% stones
Okada / Japan 1996[19]102~90%—22% efferent + 27% afferent malfunction; 44% stones; 38% open revision

Urethral (Orthotopic) Kock Pouch​

SeriesnDaytimeNighttimeNotes
Ghoneim / Kock 1987[10]16100%75%First urethral Kock; 3 responded to desmopressin
Kock / Ghoneim 1989[11]4388%88%42% reflux from valve failure
Henriet 1991[17]4593%65%—
Ghoneim 1992[12]185 (117 evaluable)92%73%90% upper tracts stable/improved
Elmajian / Stein / USC 1996[9]29587% (good/satisfactory)86%4.1% stones; 2.4% afferent stenosis; 5% CIC
Steven / Copenhagen 2000[13]16697–100% (1–5 yr)75–94% (1–5 yr)34% stones at 5 yr; 33% B12 deficiency at 5 yr

Urodynamic Characteristics​

ParameterResult
Functional pouch capacity280–600 mL (increases over 3–6 months)
Mean intrapouch pressure (no spikes)11.6–13.3 cm H₂O
Mean intrapouch pressure (with spikes)41.0 cm H₂O
Involuntary pressure spikes25% of patients
Mean maximal nipple pressure72.1 cm H₂O
Mean maximal nipple closure pressure58.8 cm H₂O
Mean functional nipple length3.4 cm
Mean urethral resting resistance (orthotopic)64 cm H₂O
Voiding pressure (orthotopic)33–150 cm H₂O (44% had extremely high pressures)

A functional nipple length ≤ 2.5 cm and/or maximal nipple closure pressure below baseline reservoir pressure predicts incontinence.[20][11][21]

Complications — The "Achilles' Heel"​

The Kock pouch's defining limitation is the high rate of nipple-valve-related complications requiring reoperation.[6][7]

Afferent Nipple Valve Complications (USC, 802 patients)​

ComplicationIncidenceManagement
Overall afferent valve complications9.8% (79/802)—
Stone formation on staples5.2%Endoscopic removal
Stenosis4.3%Dilation or open revision
Prolapse0.9%Open revision
Endoscopic treatment7.0%Outpatient, local sedation
Open surgical revision3.1%—

Afferent valve stenosis presented with flank pain (54%), creatinine elevation (54%), and recurrent infections (38%) at a mean 39 months (range 2–75) postoperatively.[22] Approximately 50% responded to a single dilation; recurrent stenosis usually required open revision. Late afferent obstruction can present even after 17 years, requiring nephrostomy and surgical repair.[23]

Efferent Nipple Valve Complications​

  • Efferent malfunction — 9 of 68 Kock pouch patients (13.2%) in the Arai series; 5 required surgical revision.[18]
  • Pinhole fistula or false passage at the base of the efferent nipple is the most common reason for reoperation (10–15%).[4]
  • In the Carr/Webster comparison, 53% of Kock pouch patients required surgical revision, mostly for efferent limb problems.[24]

Anchoring Collar Complications​

The use of nonabsorbable Marlex / polypropylene or Dacron collars caused erosion into the pouch lumen with stone formation, obstruction, and infection. In the Arai series, 15 of 16 afferent limb complications were caused by the polyester fabric collar.[15][18] These complications led to abandonment of nonabsorbable collars.

Stone Formation​

SeriesStone Incidence
Ginsberg / USC 1991 (n=383)[25]16.7% (22% recurrence)
Arai / Japan 1993 (n=76)[18]26.5%
Terai / Japan 1996 (n=72)[26]43.1% (5-yr stone-free 66%)
Okada / Japan 1996 (n=102)[19]44%
Steven / Copenhagen 2000 (n=166)[13]18% at 3 yr; 34% at 5 yr

Stones typically form on exposed metallic staples or eroded nonabsorbable collars.[25] Reduction in stapling and elimination of the Marlex collar reduced incidence to ~10% in later USC series.[25] Most stones were managed endoscopically.

Overall Reoperation Rates​

SeriesReoperation Rate
Skinner / USC 1987 (n=250)[1]31% (85 revisions in 77 patients)
Skinner / USC 1988 post-1985 (n=531)[4]22% late complications; 10–15% reoperation
Arai / Japan 1993 (n=68)[18]22.1%
Okada / Japan 1996 (n=95)[19]38% open repair
Carr / Webster 1996 (n=30)[24]53% (26 revisions)

Metabolic Consequences​

Vitamin B12 Deficiency​

The Kock pouch uses 60–80 cm of terminal ileum — the exclusive site of B12 absorption.

  • Pannek 1996 — absorptive capacity decreased in 20/25 (80%) Kock patients vs 0/29 ileal-neobladder patients. Loss of ~50 cm of terminal ileum is the critical threshold.[27]
  • Steven / Copenhagen 2000 — 5-year B12 deficiency 33% in 166 orthotopic Kock patients.[13]
  • Terai 1997 — mean serum B12 lower in Kock (506 pg/mL) and Indiana (536 pg/mL) than in ileal conduit (727 pg/mL); 33% Kock B12 malabsorbers on Schilling test.[28]
  • Abd-el-Gawa 2002 — pediatric / adolescent Kock reservoirs followed 5–12 yr: B12 declined over time; lifelong B12 therapy recommended for true deficiency.[29]

See Vitamin B12 Supplementation.

Hyperchloremic Metabolic Acidosis​

Generally mild and clinically insignificant in patients with normal baseline renal function; only 1 of 51 patients in the initial USC series, with preexisting compromised renal function.[2][4] The continent reservoir causes long-term increases in urinary calcium, phosphate, and magnesium excretion vs ileal conduit, potentially promoting calcium urolithiasis.[30] See Urinary Acidifiers & Alkalinizers.

Kock Pouch vs Other Continent Diversions​

Kock vs Indiana Pouch​

ParameterKock PouchIndiana Pouch
Early complications18.4%17.9%
Late revision rate22.1%10.8%
Stone formation26.5–44%5.4–19%
ContinenceSatisfactorySatisfactory
Efferent valve malfunction13.2%Stomal stenosis 12–19%
Afferent valve malfunction24–27%Rare

The Indiana pouch achieved comparable continence with significantly lower stone formation and reoperation rates, leading many centers to transition away from the Kock pouch.[18][19]

Kock vs Right Colon Pouch (Carr/Webster 1996)​

Single-surgeon sequential comparison (30 Kock → 30 right colon pouch): Kock revision 53% (mostly efferent limb) vs right colon pouch 13%. The markedly higher revision rate drove the practice change.[24]

Continent Cutaneous Diversion in the Modern Era​

A contemporary CCUD cohort (322 patients, 2002–2013, mostly modified Indiana pouch): 89% continence at median 36 mo, 88% catheterizing every 4–8 h, complication and renal-function outcomes comparable to orthotopic substitute and ileal conduit.[31]

The T-Pouch — Evolution from the Kock Pouch​

The T-pouch, developed by John P. Stein at USC in 1998, was specifically designed to eliminate the complications of the intussuscepted afferent nipple valve while preserving the Kock reservoir's urodynamic properties.[14]

  • Replaces the intussuscepted afferent nipple with a serous-lined ileal tunnel (inspired by the Mansoura SLET).
  • Eliminates the need for intussusception, staples, and anchoring collars — the primary sources of Kock complications.
  • Initial 40 patients: no perioperative deaths (1 unrelated, 2.5%), 5 early complications (12.5%, none diversion-related), no late complications, no reflux, excellent capacity.
  • Adapted for continent fecal ileostomy by Kaiser and Stein (2002); 10-year results in 40 patients: 92% continence, 87.5% patient satisfaction.[32][33]

See T-Pouch Modification and Double-T Pouch.

Strengths and Limitations​

Strengths

  • Pioneering concept establishing the principles of all modern continent diversion: detubularization, low-pressure reservoir, continent valve mechanisms.[3][4][6]
  • Best urodynamic properties — the lowest intraluminal pressures (11.6–13.3 cm H₂O) and highest capacities (up to 1,400 mL) of any continent reservoir.[2][4][20]
  • Highly effective antireflux mechanism — > 95% reflux-free.[4]
  • Excellent continence (84–100% across series).
  • Largest single-center experience (802+ patients at USC).[8]
  • Versatile — adapted for cutaneous diversion, orthotopic neobladder, ileorectal pouch, and augmentation cystoplasty.

Limitations

  • High reoperation rate (22–53%) — the defining limitation, primarily nipple-valve complications.[1][4][18][19][24]
  • Stone formation (16.7–44%) related to exposed staples and eroded nonabsorbable collars.[25][26][18][19]
  • Nipple-valve dessusception / prolapse — efferent particularly prone.[4][18]
  • Afferent nipple-valve complications (9.8–27%) — stenosis, stone formation, prolapse, sometimes presenting decades after surgery.[8][15][23]
  • Vitamin B12 deficiency (33–80% malabsorption) — long ileal segment removes the primary B12 absorption site.[13][27][28]
  • Technical complexity — intussusception requires significant expertise.[6][7]
  • Nonabsorbable material complications — Marlex collar erosion was a major source of morbidity until abandoned.[15][18][25]

Current Status and Legacy​

The Kock pouch in its original form is rarely performed today, having been supplanted by ileocecal-valve-based pouches (Indiana, Mainz I) for continent cutaneous diversion and by purely ileal neobladders (Studer, Hautmann) and the T-pouch for orthotopic substitution. The reasons are well-established: equivalent continence with substantially lower stone formation, reoperation, and B12-deficiency burden.

Legacy contributions:

  1. The Kock pouch established the fundamental principles of continent urinary diversion — detubularization, spherical reconfiguration, continent and antireflux valve mechanisms.[3][4][6]
  2. The largest single-center continent urinary diversion experience (802+ patients at USC) provided the most comprehensive complication and outcome data ever assembled for any continent diversion.[8]
  3. The recognition that nonabsorbable anchoring materials erode and form stones drove the move to absorbable fixation across the entire continent-diversion field.[15][25]
  4. The Kock urethral pouch (Mansoura) was one of the earliest orthotopic neobladder experiences and helped establish the orthotopic concept.[10][11][12]
  5. The Kock pouch directly seeded the T-pouch evolution, which retained the urodynamic advantages of the reservoir while replacing the intussuscepted nipple with a serous-lined tunnel — the most significant Kock-derived contribution to the modern era.[14]

Key Takeaways​

  1. The Kock pouch is the historical foundation of all continent urinary diversion — first described by Nils Kock in 1969 (fecal) and 1975 (urinary), championed and refined by Skinner at USC.[1][2][3][4]
  2. Cutaneous Kock pouch achieves 84–95% continence with excellent urodynamics but a 22–53% reoperation rate — the defining limitation.[1][4][18][24]
  3. Orthotopic Kock neobladder (Mansoura, USC, Copenhagen) achieves 87–100% daytime / 73–94% nighttime continence, but the 5-year stone risk is 34% and B12 deficiency 33%.[12][13][9]
  4. The Kock pouch's "Achilles' heel" is the intussuscepted nipple valve — stenosis, prolapse, stone formation on staples, and erosion of nonabsorbable collars.[8][15][18][25]
  5. The 1998 T-pouch (Stein) replaced the intussuscepted afferent nipple with a serous-lined tunnel, eliminating the dominant Kock-pouch complications while preserving urodynamic advantages.[14]
  6. Although rarely performed today, the Kock pouch's principles — detubularization, low-pressure reservoir, continent valve mechanisms — underpin every modern continent diversion and orthotopic neobladder.

See Also​

References​

1. Skinner DG, Lieskovsky G, Boyd SD. "Continuing Experience With the Continent Ileal Reservoir (Kock Pouch) as an Alternative to Cutaneous Urinary Diversion: An Update After 250 Cases." J Urol. 1987;137(6):1140–5. doi:10.1016/s0022-5347(17)44429-6

2. Skinner DG, Boyd SD, Lieskovsky G. "Clinical Experience With the Kock Continent Ileal Reservoir for Urinary Diversion." J Urol. 1984;132(6):1101–7. doi:10.1016/s0022-5347(17)50052-x

3. Gerber A. "The Kock Continent Ileal Reservoir for Supravesical Urinary Diversion. An Early Experience." Am J Surg. 1983;146(1):15–20. doi:10.1016/0002-9610(83)90252-0

4. Skinner DG, Lieskovsky G, Boyd SD. "Continent Urinary Diversion. A 5 1/2 Year Experience." Ann Surg. 1988;208(3):337–44. doi:10.1097/00000658-198809000-00011

5. Angistriotis A, Shen B, Kiran RP. "Construction of and Conversion to Continent Ileostomy: A Systematic Review." Dis Colon Rectum. 2022;65(S1):S26–S36. doi:10.1097/DCR.0000000000002631

6. Nessar G, Wu JS. "Evolution of Continent Ileostomy." World J Gastroenterol. 2012;18(27):3479–82. doi:10.3748/wjg.v18.i27.3479

7. Cranley B. "The Kock Reservoir Ileostomy: A Review of Its Development, Problems and Role in Modern Surgical Practice." Br J Surg. 1983;70(2):94–9. doi:10.1002/bjs.1800700214

8. Stein JP, Freeman JA, Esrig D, et al. "Complications of the Afferent Antireflux Valve Mechanism in the Kock Ileal Reservoir." J Urol. 1996;155(5):1579–84. PMID: 8627828

9. Elmajian DA, Stein JP, Esrig D, et al. "The Kock Ileal Neobladder: Updated Experience in 295 Male Patients." J Urol. 1996;156(3):920–5. doi:10.1016/s0022-5347(01)65663-5

10. Ghoneim MA, Kock NG, Lycke G, el-Din AB. "An Appliance-Free, Sphincter-Controlled Bladder Substitute: The Urethral Kock Pouch." J Urol. 1987;138(5):1150–4. doi:10.1016/s0022-5347(17)43531-2

11. Kock NG, Ghoneim MA, Lycke KG, Mahran MR. "Replacement of the Bladder by the Urethral Kock Pouch: Functional Results, Urodynamics and Radiological Features." J Urol. 1989;141(5):1111–6. doi:10.1016/s0022-5347(17)41185-2

12. Ghoneim MA, Shaaban AA, Mahran MR, Kock NG. "Further Experience With the Urethral Kock Pouch." J Urol. 1992;147(2):361–5. doi:10.1016/s0022-5347(17)37238-5

13. Steven K, Poulsen AL. "The Orthotopic Kock Ileal Neobladder: Functional Results, Urodynamic Features, Complications and Survival in 166 Men." J Urol. 2000;164(2):288–95. PMID: 10893571

14. Stein JP, Lieskovsky G, Ginsberg DA, Bochner BH, Skinner DG. "The T Pouch: An Orthotopic Ileal Neobladder Incorporating a Serosal Lined Ileal Antireflux Technique." J Urol. 1998;159(6):1836–42. doi:10.1016/S0022-5347(01)63170-7

15. Arai Y, Okada Y, Matsuda T, et al. "Afferent Nipple Valve Malfunction Caused by Anchoring Collar: An Unexpected Late Complication of the Kock Continent Ileal Reservoir." J Urol. 1991;145(1):29–32. doi:10.1016/s0022-5347(17)38238-1

16. Chen KK, Chang LS, Chen MT, et al. "Clinical Experience of Kock Pouch Continent Urinary Diversion." Urology. 1990;35(4):317–20. doi:10.1016/0090-4295(90)80154-f

17. Henriet MP, Neyra P, Elman B. "Kock Pouch Procedures: Continuing Experience and Evolution in 135 Cases." J Urol. 1991;146(1):16–20. doi:10.1016/s0022-5347(17)37703-0

18. Arai Y, Kawakita M, Terachi T, et al. "Long-Term Followup of the Kock and Indiana Pouch Procedures." J Urol. 1993;150(1):51–5. doi:10.1016/s0022-5347(17)35394-6

19. Okada Y, Shichiri Y, Terai A, et al. "Management of Late Complications of Continent Urinary Diversion Using the Kock Pouch and the Indiana Pouch Procedures." Int J Urol. 1996;3(5):334–9. doi:10.1111/j.1442-2042.1996.tb00549.x

20. Chen KK, Chang LS, Chen MT. "Urodynamic and Clinical Outcome of Kock Pouch Continent Urinary Diversion." J Urol. 1989;141(1):94–7. doi:10.1016/s0022-5347(17)40602-1

21. Gotoh M, Yoshikawa Y, Sahashi M, et al. "Urodynamic Study of Storage and Evacuation of Urine in Patients With a Urethral Kock Pouch." J Urol. 1995;154(5):1850–3. PMID: 7563366

22. Stein JP, Huffman JL, Freeman JA, et al. "Stenosis of the Afferent Antireflux Valve in the Kock Pouch Continent Urinary Diversion: Diagnosis and Management." J Urol. 1994;151(2):338–40. doi:10.1016/s0022-5347(17)34942-x

23. Locke JA, Neu S, Herschorn S. "Diagnosis and Management of Kock Afferent Nipple Valve Obstruction." Urology. 2021;152:173–7. doi:10.1016/j.urology.2021.02.023

24. Carr LK, Webster GD. "Kock Versus Right Colon Continent Urinary Diversion: Comparison of Outcome and Reoperation Rate." Urology. 1996;48(5):711–4. doi:10.1016/S0090-4295(96)00424-4

25. Ginsberg D, Huffman JL, Lieskovsky G, Boyd S, Skinner DG. "Urinary Tract Stones: A Complication of the Kock Pouch Continent Urinary Diversion." J Urol. 1991;145(5):956–9. doi:10.1016/s0022-5347(17)38499-9

26. Terai A, Ueda T, Kakehi Y, et al. "Urinary Calculi as a Late Complication of the Indiana Continent Urinary Diversion: Comparison With the Kock Pouch Procedure." J Urol. 1996;155(1):66–8. PMID: 7490902

27. Pannek J, Haupt G, Schulze H, Senge T. "Influence of Continent Ileal Urinary Diversion on Vitamin B12 Absorption." J Urol. 1996;155(4):1206–8. PMID: 8632532

28. Terai A, Okada Y, Shichiri Y, et al. "Vitamin B12 Deficiency in Patients With Urinary Intestinal Diversion." Int J Urol. 1997;4(1):21–5. doi:10.1111/j.1442-2042.1997.tb00133.x

29. Abd-el-Gawa G, Abrahamsson K, Norlén L, Hjälmås K, Hanson E. "Vitamin B12 and Folate After 5–12 Years of Continent Ileal Urostomy (Kock Reservoir) in Children and Adolescents." Eur Urol. 2002;41(2):199–205. doi:10.1016/s0302-2838(01)00032-x

30. Terai A, Arai Y, Kawakita M, Okada Y, Yoshida O. "Effect of Urinary Intestinal Diversion on Urinary Risk Factors for Urolithiasis." J Urol. 1995;153(1):37–41. doi:10.1097/00005392-199501000-00016

31. Al Hussein Al Awamlh B, Wang LC, Nguyen DP, et al. "Is Continent Cutaneous Urinary Diversion a Suitable Alternative to Orthotopic Bladder Substitute and Ileal Conduit After Cystectomy?" BJU Int. 2015;116(5):805–14. doi:10.1111/bju.12919

32. Kaiser AM, Stein JP, Beart RW. "T-Pouch: A New Valve Design for a Continent Ileostomy." Dis Colon Rectum. 2002;45(3):411–5. doi:10.1007/s10350-004-6192-2

33. Kaiser AM. "T-Pouch: Results of the First 10 Years With a Nonintussuscepting Continent Ileostomy." Dis Colon Rectum. 2012;55(2):155–62. doi:10.1097/DCR.0b013e31823a969b