DOI:10.2214/AJR.05.0870
AJR 2006; 187:W594-W603
© American Roentgen Ray Society
Pouchography, CT, and MRI Features of Ileal J Pouch-Anal Anastomosis
Michel D. Crema1,
Delphine Richarme1,
Louisa Azizi1,
Christine C. Hoeffel1,
Jean-Michel Tubiana1 and
Lionel Arrivé1
1 All authors: Department of Radiology, Saint-Antoine Hospital, 184 rue du
faubourg Saint-Antoine, Paris, France 75012.
Received May 23, 2005;
accepted after revision August 31, 2005.
Address correspondence to L. Arrivé
(lionel.arrive{at}sat.ap-hop-paris.fr).
WEB
This is a Web exclusive article.
Abstract
OBJECTIVE. Our objective is to describe pouchography, CT, and MRI
features of the J-shaped pouch, both normal and with pouch-related
complications.
CONCLUSION. Pouchography is performed before closure of the loop
ileostomy to assess the integrity of the ileal pouch and anastomosis. CT and
MRI can be performed when postoperative complications, such as small-bowel
obstruction, pouchitis, leakage, abscess, intramural hematoma, desmoid tumor,
or recurrent Crohn's disease, are suspected.
Keywords: abdominal imaging • colon • CT imaging • gastrointestinal radiology • inflammatory bowel disease • pouch-anal anastomosis
Introduction
Total proctocolectomy with ileal pouch-anal anastomosis is the surgical
therapy of choice for patients with ulcerative colitis after failure of
medical treatment and for patients with familial adenomatous polyposis (FAP).
The pouch-anal anastomosis procedure includes colectomy, creation of an ileal
pouch, ileal pouch-anal anastomosis, and temporary loop ileostomy, which is
closed 8-12 weeks later. Currently, the J-shaped pouch is the most common type
of ileal reservoir. This procedure completely removes the diseased colon while
retaining transanal defecation. Crohn's disease is considered an absolute
contraindication to use of the pouch-anal anastomosis procedure because of the
risk of recurrent disease in the terminal ileum. Pouchography using a
water-soluble contrast agent is usually performed before closure of the loop
ileostomy to assess the ileal pouch and pouch-anal anastomosis integrity. CT
or MRI examinations of the reservoir may be performed when complications are
suspected clinically or after the pouchography. This article describes
pouchography, CT, and MRI features of the J-shaped pouch, both normal and with
pouch-anal anastomosis-related complications.
Fluoroscopic Contrast Examination (Pouchography)
The ileal J pouch, a modification of that originally described by
Utsunomiya et al. [1], is
created by folding 15 cm of the terminal ileum back on itself. Anastomosis of
the apposing ileal loops in a side-to-side fashion is performed with a linear
stapling device. After the distal part of the pouch is stapled through an
enterotomy aperture in the elbow of the J, circumferential anastomosis to the
anus along the pectinate line is performed
(Fig. 1).
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Fig. 1 —Drawing of J pouch-anal anastomosis. Ileal J pouch is created
by folding 15 cm of terminal ileum back on itself. After anastomosis of
opposite ileal loops in side-to-side fashion, anastomosis of ileal reservoir
apex to anus along pectinate line is performed. Note that efferent limb of
loop ileostomy is same portion of bowel as afferent limb of ileal J pouch.
IPAA = ileal pouch-anal anastomosis.
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Fig. 2 —41-year-old man with ulcerative colitis who underwent total
proctocolectomy and ileal J pouchanal anastomosis. Anteroposterior radiograph
of contrast enema shows ileal J pouch (white arrow), dual row of
pouch staples (gray arrowheads), and ileal pouch-anal anastomosis
(white arrowheads). Proximal limb (gray arrow) and blind
ileal stump (black arrow) are easily identified.
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Classically, radiographic examination of the ileal J pouch is performed
before closure of the loop ileostomy to assess the integrity of the ileal
pouch and pouch-anal anastomosis (Fig.
2). This radiographic examination is performed by fluoroscopic
visualization with a contrast agent that could be introduced in an antegrade
position through a cannula fitted in the efferent limb of the loop ileostomy
using a 16- to 18-French Foley catheter, or retrogradely through the anus. The
antegrade approach is considered the safer technique and is commonly used for
pouch examination.
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Fig. 3A —Ileal pouch-anal anastomosis in 27-year-old woman with
familial adenomatous polyposis. CT examination shows ileal pouch identified by
row of staples (arrows) opposed 180x to each other.
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In our institution, retrograde opacification is performed with a Foley
catheter carefully placed by the referring surgeon to avoid any damage by
perforation of the ileal J pouch-anal anastomosis. Examination with a
water-soluble contrast agent is preferred. Alfisher et al.
[2] recommend the retrograde
fashion with a 14-French Foley catheter that should be kept above the
pouch-anal anastomosis, which, unlike the antegrade approach, often results in
optimal pouch distention and evaluation. The fully distended pouch must be
visualized by anteroposterior, oblique, and lateral views to show any
anastomotic leak or stricture
[3]. Postevacuation
anteroposterior and lateral views of the pouch and the pouch-anal anastomosis
also should be obtained to show leakage that is otherwise occulted.
CT
CT is used when postoperative complications are suspected during clinical
or fluoroscopic examinations. CT currently is the best method to assess
pouch-anal anastomosis-related septic complications. A nonionic contrast agent
is injected IV in all cases. When leakage or abscess is suspected, a
water-soluble contrast agent is injected anally using a Foley catheter placed
in the same manner as for fluoroscopic retrograde opacification.
CT shows pouch-anal anastomosis features as well as all surrounding
anatomic structures. The pouch is identified by the characteristic row of
staples (metallic density) opposed 180x to each other. The level of the
pouch-anal anastomosis is also identifiable (Figs.
3A and
3B). Extraluminal contrast
material, fluid, or air is abnormal. Its localization near the pouch should be
analyzed to determine its relationship to the actual pouch lumen. Peripouch
mesenteric fat and perirectal fat stranding are more common in patients with
pouch-anal anastomosis-related septic complications, although perirectal fat
infiltration may also be caused by chronic inflammatory changes associated
with ulcerative colitis
[4].
MRI
To our knowledge, the literature has very little information about the MRI
appearance of ileoanal reservoirs, and MRI is not commonly used to assess
pouch-anal anastomosis structures and complications. However, MRI is accurate
in detecting perianal fistulas and pelvic collections. Pelvic desmoid tumors
are frequently associated with FAP and can be easily identified by MRI
examination [5].
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Fig. 4A —MRI examination of 33-year-old woman with familial
adenomatous polyposis who underwent proctocolectomy and ileal J pouch-anal
anastomosis. Axial T2-weighted image. Pouch is identified by row of staples
(arrows) presenting as small ferromagnetic artifacts on MRI (metallic
signal).
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Fig. 4B —MRI examination of 33-year-old woman with familial
adenomatous polyposis who underwent proctocolectomy and ileal J pouch-anal
anastomosis. Sagittal T2-weighted image. Pouch (arrow) is identified
by row of staples (arrows in A) presenting as small
ferromagnetic artifacts on MRI (metallic signal). Pouch-anal anastomosis
(arrowheads) can also be identified.
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Fig. 5A —Small-bowel obstruction in 22-year-old woman with familial
adenomatous polyposis who underwent ileal J pouch-anal anastomosis. CT shows
dilated small bowel (D), nondilated small bowel (ND), and transition area
(arrows). Cause of obstruction was determined to be an adhesion.
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Fig. 5B —Small-bowel obstruction in 22-year-old woman with familial
adenomatous polyposis who underwent ileal J pouch-anal anastomosis. Pouch is
identified by row of staples (arrows). Note dilated small bowel in
right iliac fossa (arrowheads).
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In our institution, the sequences used for pelvic MRI assessment are turbo
spin-echo; T2-weighted sagittal, coronal, and axial; turbo spin-echo
T1-weighted; STIR; and turbo spin-echo T1-weighted with fat-suppression and a
gadolinium-based IV contrast agent in the axial plane. With these turbo
spin-echo sequences, we do not use glucagon to minimize bowel motion artifact.
MRI is performed with a body phased-array coil requiring no patient
preparation. The pouch is identified, as with CT, from the row of staples
presenting as small ferromagnetic artifacts on all the sequences performed
(metallic signal) (Figs. 4A and
4B). It is also possible to
evaluate the pelvic structures around the pouch-anal anastomosis during MRI
examinations.
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Fig. 6A —Pouchitis in 49-year-old woman with familial adenomatous
polyposis who had episodes of pelvic pain, fever, and tenesmus. CT shows
marked pouch wall thickening (arrows). Note pelvic desmoid tumor
compressing pouch wall (arrowheads, B).
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Fig. 6B —Pouchitis in 49-year-old woman with familial adenomatous
polyposis who had episodes of pelvic pain, fever, and tenesmus. CT shows
marked pouch wall thickening (arrows). Note pelvic desmoid tumor
compressing pouch wall (arrowheads, B).
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Fig. 7A —63-year-old woman with familial adenomatous polyposis who
underwent ileal J pouch-anal anastomosis. CT examination with contrast enema
shows anastomotic leakage (arrow) caused by anastomotic
separation.
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Complications
Small-Bowel Obstruction
Small-bowel obstruction is the most frequent complication of pouch-anal
anastomosis, with the obstruction point classically on the ileostomy closure
site and in the small bowel distal to it. Small-bowel obstructions are
reported to occur in 33% of patients, with most of these obstructions
occurring more than 30 days after ileostomy closure
[2]. Most of these obstructions
are caused by postoperative adhesions, strictures, and small-bowel volvulus.
Surgical intervention is usually necessary, and CT examination can help
identify the small-bowel obstruction site (Figs.
5A and
5B). However, patients can
develop small-bowel obstruction before the loop ileostomy closure and can be
successfully managed by nasogastric tube suction and delayed ileostomy
closure.
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Fig. 8A —36-year-old man with familial adenomatous polyposis who
underwent ileal J pouch-anal anastomosis. CT examination with contrast enema
shows pouch leakage (arrow) caused by pouch dehiscence. No staple is
identified at leakage site.
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Pouchitis
Pouchitis is a poorly understood inflammatory condition that affects the
ileal pouch of patients undergoing the pouch-anal anastomosis operation. It is
characterized by superficial ulcerations in the pouch as seen on pouch
endoscopy and by microscopic ulcers seen on pathologic examination. Biopsy
findings of the ileal pouch mucosa in these cases resemble colonic mucosa in
ulcerative colitis. Clinically, pouchitis is a syndrome characterized by
diarrhea, pelvic discomfort, low-grade fever, tenesmus, and other systemic
symptoms. This condition is more frequent in patients with ulcerative colitis
than in patients with FAP [6].
There is no specific finding for pouchitis in a radiologic evaluation.
Fluoroscopy contrast examination findings include spicules, thickening of
folds, and pouch spasm. CT findings include a thickened pouch wall with
stranding of the peripouch fat (Figs.
6A and
6B). The usual treatment is
antibiotic therapy.
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Fig. 9 —Pouch-vaginal fistula in 36-year-old woman with familial
adenomatous polyposis who underwent ileal J pouch-anal anastomosis.
Fluoroscopic contrast examination shows contrast agent filling pouch (gray
arrow) and vagina (arrowheads), expressing pouch-vaginal fistula
(white arrow).
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Fig. 10A —Pouch-vaginal fistula in 35-year-old woman with ulcerative
colitis who underwent ileal J pouch-anal anastomosis. CT examination with
contrast enema shows fistulous track (arrow) linking anastomotic site
and vagina.
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Fig. 10B —Pouch-vaginal fistula in 35-year-old woman with ulcerative
colitis who underwent ileal J pouch-anal anastomosis. MRI examination
(T1-weighted with fat suppression and IV gadolinium) shows fistulous track
(arrow) linking anastomotic site and vagina.
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Leakage
Leakage from the pouch occurs on the staple line as a result of pouch
dehiscence and more frequently at the pouch-anal anastomosis as a result of
anastomotic separation (Figs.
7A,
7B,
8A,
8B, and
8C). Leakage can result in a
simple sinus tract without septic or inflammatory complications, in which case
ileostomy takedown must be delayed. A long, blind, partially opacified ileal
stump can simulate a sinus tract.
Leakage may also result in a fistula or abscess, considered to be a
pouch-related septic complication. The prevalence of a pouch-related septic
complication varies between 6% and 37%
[7], and it can jeopardize the
outcome of the procedure in certain patients. The risk of a pouch-related
septic complication is greater in patients with ulcerative colitis than in
patients with FAP, probably because of the use of systemic corticoid
medication before surgery, which impairs the bowel anastomosis healing process
and increases susceptibility to infection and other side effects
[7]. Anastomotic tension is
also a significant risk factor for pouch-related septic complication. Pelvic
infection may also be secondary to pelvic contamination during surgery
[2].
Clinical manifestations of pouch-related septic complication include
localized pain, purulent drainage, and fever. Types of fistulas include
pouch-anus, pouch-vagina (Figs.
9,
10A, and
10B), pouch-bladder, and
enterocutaneous.
Pouchography and CT show similar sensitivities in detecting pouch-anal
anastomosis fistulas [8].
Fistula pouchography results include a tract of contrast agent extending from
the pouch-anal anastomosis structures into the soft tissue surrounding the
pouch. This is also visible at CT examination and is usually associated with
stranding of the fat surrounding the tract
(Fig. 11).
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Fig. 11 —Pouch fistula in 52-year-old man with ulcerative colitis who
underwent ileal J pouch-anal anastomosis. CT examination with contrast enema
shows sinus track (black arrow) linking pouch (white arrow)
and presacral collection (arrowheads).
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Fig. 12A —MRI examination in 52-year-old woman with ulcerative colitis
who underwent ileal J pouch-anastomosis. Axial T1-weighted image with fat
suppression and IV gadolinium shows enhanced sinus track posterior to ileal J
pouch (arrow).
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MRI is highly sensitive for detecting perianal fistulas. On T2-weighted and
STIR images, they appear as areas of higher signal intensity than the
pouch-anal anastomosis structures, muscles, and fat (especially on STIR
images). Active fistulous tracks appear with sharply enhanced intensity on
T1-weighted fat-suppression images after IV gadolinium injection (Figs.
12A,
12B, and
12C).
CT is more sensitive than pouchography for detecting pouch-anal
anastomosis-related abscesses
[4,
8]. Abscess pouchography with
or without a contrast agent results include a compression or a displacement of
the pouch with or without air bubbles, spiculations, and thickening of folds.
CT results (Figs. 8A,
8B, and
8C) include a soft-tissue mass
adjacent to pouch-anal anastomosis structures, visible with or without an
enhancing rim, contrast agent, or air bubbles.
MRI is also accurate in detecting pelvic abscess. On T2-weighted and STIR
images, it appears as collections of high signal intensity and exhibits low
signal intensity with an enhancing rim on T1-weighted contrast-enhanced
fat-suppression images (Figs.
13A and
13B).
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Fig. 13A —MRI examination in 50-year-old woman with Crohn's disease who
underwent total proctocolectomy and ileal J pouch-anal anastomosis. Axial
T2-weighted image shows hyperintense presacral mass (arrow) diagnosed
as pelvic abscess secondary to anastomotic leakage.
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Fig. 13B —MRI examination in 50-year-old woman with Crohn's disease who
underwent total proctocolectomy and ileal J pouch-anal anastomosis. Axial
T1-weighted image with fat suppression and IV gadolinium shows characteristic
rim enhancement (arrow).
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Pouch-anal anastomosis-related fistulas in some cases necessitate permanent
ileostomy with or without pouch excision. Pouch-anal anastomosis-related
abscesses can be managed by surgical or percutaneous drainage under CT
guidance and antibiotic treatment (Figs.
8A,
8B, and
8C). Pouchrelated septic
complication may require that ileostomy closure be delayed or fecal diversion
be reestablished if the ileostomy is already closed. If pouch-anal anastomosis
separation with leakage is the cause of pouch-related septic complication,
surgical repair of the separation is necessary.
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Fig. 14 —Anastomotic stricture in 28-year-old woman with familial
adenomatous polyposis who underwent ileal J pouch-anal anastomosis. Oblique
radiograph of contrast enema examination shows ileal pouch-anal anastomotic
stricture (white arrow) after J pouch opacification (black
arrows). Note sinus track near pouch-anal anastomosis
(arrowhead).
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Fig. 15A —Pelvic desmoid tumor in 29-year-old woman with familial
adenomatous polyposis who underwent ileal J pouch-anal anastomosis. Axial
T2-weighted image shows heterogeneous mass (white arrow) near upper
pole of J pouch (black arrow).
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Fig. 15B —Pelvic desmoid tumor in 29-year-old woman with familial
adenomatous polyposis who underwent ileal J pouch-anal anastomosis. Sagittal
T2-weighted image shows heterogeneous mass (white arrow) near upper
pole of J pouch (black arrow).
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Anastomotic Stricture
Pouch-anal anastomosis strictures occur in 8-14% of patients
[3]. Most pouch-anal
anastomosis procedures induce some degree of narrowing without outlet
obstruction. Clinical examination is sufficient to evaluate pouch-anal
anastomosis strictures. Pouchography can also show pouch-anal anastomosis
strictures (Fig. 14).
Anastomotic stricture management includes anastomotic dilatation under
anesthesia, usually with good response.
Unusual Complications
Intramural hematoma of the J pouch is a rare postoperative complication of
the pouch-anal anastomosis procedure. The scar tissue produced by hematoma
development can eventually impair pouch function. A residual septum near the
apex of the J pouch may result in bleeding and tenesmus as a direct result of
the pouch construction technique.
Desmoid tumors are commonly associated with FAP and may be expressed as
large pelvic masses. These tumors can compress the pouch and cause variable
pouch dysfunction. MRI is accurate in detecting desmoid tumors (Figs.
15A and
15B). CT can also help to
detect desmoid tumors (Figs. 6A
and 6B).
A postoperative diagnosis of Crohn's disease with recurrent disease in the
remaining small bowel can lead to multiple complications such as fistulas,
abscesses, ileitis (Fig. 16),
specific pouchitis (Figs. 17A
and 17B), and small-bowel
obstruction.
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Fig. 17A —Specific pouchitis in 59-year-old woman with recurrent
Crohn's disease who underwent ileal J pouch-anal anastomosis. CT examination
shows pouch wall thickening (arrowheads). Note proliferation of fatty
tissue (arrows) around ileal pouch.
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Fig. 17B —Specific pouchitis in 59-year-old woman with recurrent
Crohn's disease who underwent ileal J pouch-anal anastomosis. Sagittal
T2-weighted image shows fibrofatty proliferation (arrows) causing
ileal pouch displacement.
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Acknowledgments
We thank Pascale Dono for editorial assistance and Allan Banas for
technical assistance.
References
- Utsunomiya J, Iwama T, Imajo M, et al. Total colectomy, mucosal
proctectomy, and ileoanal anastomosis. Dis Colon
Rectum 1980; 23:459
-466[Medline]
- Alfisher MM, Scholz FJ, Roberts PL, Counihan T. Radiology of ileal
pouch-anal anastomosis: normal findings, examination pitfalls, and
complications. RadioGraphics 1997;17
: 81-98[Abstract]
- Seggerman RE, Chen MY, Waters GS, Ott DJ. Radiology of ileal
pouch-anal anastomosis surgery. AJR 2003;180
: 999-1002[Free Full Text]
- Brown JJ, Balfe DM, Heiken JP, Becker JM, Soper NJ. Ileal J pouch:
radiologic evaluation in patients with and without postoperative infectious
complications. Radiology 1990;174
: 115-120[Abstract/Free Full Text]
- Azizi L, Balu M, Belkacem A, Lewin M, Tubiana JM, Arrivé L.
MRI features of mesenteric desmoid tumors in familial adenomatous polyposis.
AJR 2005; 184:1128
-1135[Free Full Text]
- Barton JG, Paden MA, Lane M, Postier RG. Comparison of
postoperative outcomes in ulcerative colitis and familial polyposis patients
after ileoanal pouch operations. Am J Surg2001; 182:616
-620[CrossRef][Medline]
- Heuschen UA, Hinz U, Allemeyer EH, et al. Risk factors for ileoanal
J pouch-related septic complications in ulcerative colitis and familial
adenomatous polyposis. Ann Surg 2002;235
: 207-216[CrossRef][Medline]
- Thoeni RF, Fell SC, Englestad B, Schrock TB. Ileoanal pouches:
comparison of CT, scintigraphy, and contrast enemas for diagnosing
postsurgical complications. AJR 1990;154
: 73-78[Abstract/Free Full Text]
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Abstract
Introduction
