William
E. Shiels
II, DO
#{149} Constance
K Maves,
MD
#{149} Gary
L. Hedlund,
DO2
#{149} Donald
R. lUrks,
MD
Air Enema for Diagnosis and Reduction of Intussusception: Clinical Experience and Pressure Correlates’ Air enema was used for exclusion, diagnosis, initial movement, and complete reduction of intussusception in 186 pediatric patients. Average pressure needed for initial movement of intussusception was 56.5 mm Hg average maximum pressure of 97.8 mm Hg was required for cornplete reduction. Average fluoroscopy time required for intussusception reduction was 94.8 seconds; an average of 41.8 seconds was required to exdude intussusception. Intussusceplion was diagnosed in 75 patients, and reduction was accomplished in 65 (87%). Of 100 consecutive patients that underwent hydrostatic reduction of intussusception at the authors’ institution, reduction was successful in 55. Compared with hydrostatic enerna, air enema involves shorter fiuoroscopy time and lower radiation dose to the patient. Air enema is safe and effective for diagnosis and treatrnent of intussusception in infants and children and has replaced hydrostatic enema for such procedures at the authors’ institution.
I
several
N
has
terms:
Children,
gastrointestinal
tract
the
the
enema
air
hydrostatic
en-
ema for evaluation and treatment of intussusception in children (1-5). Since the reintroduction of the air enema for childhood intussusception, a variety of techniques for the procedure have been described (1-7). Although maximum pressure settings, success
rates,
and
complications
have
been commented on, to our knowledge, data on actual pressures and fluoroscopy time in a large series of pediatric
patients
have
not
been
avail-
able. We report pressure data and experience in a series of 186 patients in whom air enema was used to exclude, diagnose, and treat childhood intussusception. In addition, we evaluated fluoroscopic times, fluoroscopic findings, and success rate with the air enema.
MATERIALS From mas
July
were
pediatric Index
institutions,
replaced
AND
patients
in
who
1990,
186
were
air ene-
consecutive
first seen
with
Infants, gastrointestinal tract #{149} Gastrointestinal tract, interventional procedure, 74.1275, 75.1282 #{149} Intussusception, 72.73, 72.73 Radiology
2 months
181:169-172
to 15 years.
The duration blood at rectal
I From the Department of Radiology, Children’s Hospital Medical Center, and the Departments of Radiology and Pediatrics, University of Cincinnati College of Medicine, Cincinnati. From the 1990 RSNA scientific assembly. Received December 3, 1990; revision requested February 21, 1991; revision received May 7; accepted May 29. Supported in part by a Research and Educational Fund grant of the Society for Pediatric Radiology. Address reprint requests to W.E.S., Department of Radiology (HSHL-X), Pediatric Imaging, Walter Reed Army Medical Center, Washington, DC 20307. 2 Current address: Department of Radiology, Pediatric Imaging, Wilford Hall Air Force Medical Center, Lackland Air Force Base, Texas.
C RSNA,
1991
of symptoms, examination,
presence of success or fail-
ure of the enema, and number of enema attempts were recorded. The following data were also collected: pressure required for air reflux into the small bowel in patients without intussusception; pressure required for initial movement of the intussusceptum; and maximum pressure
reached (with or without lion). “Average” pressure the average used during Surgical
prior
complete reducdata represent
maximum (peak) the procedures. consultation
to air enemas.
was
Clinical
catheters,
scribed
techniques
system
consists
handhebd connected tubing
by means of previously de(7). This air reduction of a reusable, one-piece,
pressure gauge to a disposable system.
The
tubing
tem permits simultaneous with one hand, pressure fluoroscopic monitoring
Anal air seal with was
obtained
pressure
nonballoon
catheters
of the buttocks
and manual compression or with a rubber disk and tape plug applied to the external surface
of the
uously
monitored
anus.
Pressures
were
during
the
contin-
fluoroscopir
As a general rule, insufflation was limited to a maximum of 120 mm Hg, which has been recommended by other investigators (1,3,6). In some cases, at the discretion of the supervising fellow or faculty, higher pressures were used during performance of a Vabsalva maneuver with the patient straining. Operators performed a maximum of three attempts to reduce the intussusception. For each attempt, maximum pressure was maintained
for no longer
A sample
or radiobogic
than
number
permanently
archived
was
copy
times
represent
ning the procedure of intussusception
analyzed
the
time
for
from
to complete or, in patients to the
end
or water-soluble
Air enemas
enemas
performed
was
compared with in 100 consecutive
begin-
reduction without
of copious
small bowel air reflux. The reduction rate achieved achieved (barium
seda-
3 minutes.
of cases that had been
total fluoroscopic time required for excbusion or successful reduction of intussusception. These video recordings were available for 34 patients with intussusceplion and 11 patients in whom there was no evidence of intussusception. Fluoros-
intussusception, conducted
without
has an
air insufflation assessment, and (7).
by taping
enemas
performed
system
enema tip, clear tubing, protective ifiter, and trigger-positioned stopcock for instantaneous colonic decompression. The sys-
evidence of peritonitis and pneumoperitoneum were absolute contraindications to enema in patients with intussusception. were
and insufflator enema tip and
pressure
clinically suspected intussusception. Intussusception was diagnosed in 75 patients. Of the 75 patients, 53 were male and 22 were female. For the 186 patients, the average age was 19.3 months with a range of
1991;
boon
procedure.
METHODS
1988 to October
performed
tion of the patient. Radiologists from all levels of training and expertise (residents at all bevels of training, fellows, and faculty) performed air enemas; fellows and faculty supervised all procedures. Air enemas were performed with an air reduction system (Shiebs Intussusception Air Reduction System; Custom Medical Products, Maineville, Ohio) and nonbal-
with
air
the rate hydrostatic
contrast
for treatment
media) of intus-
169
a.
b.
Figure 1. (a, b) Spot radiographs obtained during intussusceptum (I) is identified in right transverse sure. Reduction required 100 mm Hg of pressure. soft-tissue mass.
susception
at our
before drostatic
contrast
the
bag
medium
3 minutes,
attempts
per
(1985-1988)
to the use of air. For hy-
enemas,
high,
than
institution
conversion
was
was
and no more patient
were
held
held
3 feet no
than
longer
three
made.
RESULTS Average to exclude
seconds four
fluoroscopy
time
required
was
41.8
seconds). The times for intus-
recorded
susception exclusion were and 17 seconds. In patients cessfub
5, 6, 10, with sucreduction, the time was 94.8
intussusception
average
fluoroscopy
(range, 14-300 seconds). five shortest fluoroscopy times corded for complete reduction
The
seconds
re-
were 14, 18, 20, 28, and 30 seconds. In these cases, 14 of 34 (41%) of the reductions were complete in less than 1 minute; in 24 of 34 (71%), reduction was completed in less than 2 minutes of fluoroscopy. In the 111 patients in whom intussusception
was
excluded,
pressure
of 60.9 mm
for
bowel
small
reflux.
an
Hg was Air
average
required
refluxed
through the ileocecab valve with as little as 20 mm Hg of pressure. In the 75 patients treated for intussusception, the average pressure required for initial movement of the intussusceptum was 56.5 mm Hg (range, 20-100 mm Hg). Complete reduction required an average pressure of 97.8 mm Hg (range, 30-160 mm Hg). It should be noted that 34% (22 of 65) of the reductions were com170
#{149} Radiology
pneumatic reduction of ileocolic intussusception. colon. (b) Intussusceptum (I) has been reduced (c) Postreduction radiograph demonstrates free
(a) At 20 mm Hg insufflation pressure, to ileocecal valve with 80 mm Hg of presflow of air into ileum and disappearance
of
pleted with a maximum of 90 mm Hg of pressure or less and 1 1 % (seven of 65) were successful with 60 mm Hg or less. An average of 1.7 attempts was necessary for complete reduction (range, 1-3 attempts). Additional attempts frequently
intussusception (range, 5-145
shortest
C.
were
made
because
of air
leaks prior to the use of the external anal seal system. No perforations or other complications resulted from air enemas.
Maximum
corded
reflected
required
for
pressures
maximum
a specific
re-
pressure
change
such
initial movement of intussusceptum or complete reduction through ileocecal
valve
and
terminal
as
the
ileum.
Pneumatic intussusception reduction was dynamic; pressures changed during the Valsalva maneuver (patient straining) and movement of the intussusceptum. Reduction of the intussusception through the ibeocecal valve consistently required the highest and most sustained pressures. The air enema was positive for intussusception in 75 of 186 patients (40.3%), for a positivity ratio of one positive enema for every 1.48 negative
enemas.
was
successful
Pneumatic
reduction
in 65 of the
(87%) with intussusception. 75 intussusceptions, 74 were
75 patients Of
these
Figure
2. Spot radiograph obtained in a child with ileocolic intussusception with a rectal mass. The intussusceptum is clearly outlined in the rectosigmoid colon. Complete reduction required 120 mm Hg of pressure.
plete
intussusceptum
reduction)
(8)
were
noted;
reduction
was
complete
subsequent
in
all four
cases
of intussusception
were
reduced.
Observations
ity
or back
tion
and
ties
during
or
All three
in the
regarding
of visibility
other
the
associated radiographs
abnormalion spot were rewere
ileocolic and one was ileoileocolic. The ileoibeocobic intussusception was reduced from the transverse colon to a final point of irreducibility 15 cm proximal to the ileocecal valve. Four pseu-
readily visible. Intussusceptions be followed throughout the
doreductions the ileocecal
disappeared was visible
(reflux of air valve preceding
through com-
the
were when
rectum
visibil-
and
All intussusceptions
sequence
rectum
of intussuscep-
fluoroscopy
overhead
corded.
cases.
could reduction
(Fig 1) from as far distal (Fig 2). Pseudoreductions
considered complete the ibeocecab mass (8). Small in all cases;
as
reductions completely bowel reflux visibility was
October
1991
a.
b.
Figure 3. Reduction
(b) Oblique the
and speed of the air enema, an experienced radiologist can exclude the diagnosis of intussusception in as little as 5-10 seconds of fluoroscopy time, and likewise reduce an uncomplicated intussusception in as little as 14-30 seconds. Because of the ease and rapidity of air insufflation, surgeons have a lower threshold for obtaming the examination in cases in which the diagnosis of intussusception is suspected. A bower radiation dose to the patient is a result of short fluoroscopy time and lower kilovolt peak and milliamperes required for air studies, compared with those required for barium or water-soluble contrast enemas (4). Our data show marked variation in the pressure required to exclude intussusception. We found that high insufflation pressures often are not required to exclude intussusception, which is demonstrated by our success with as little as 20-30 mm Hg. There are two criteria for complete
ileoileal
Spot radiographs obtained during reduction of could not be completed. (a) Intussusceptum (I) view shows distal ileoileal intussusceptum (I) component was located 15 cm proximal to the
overlying associated
an ileoileocolic intussusception. has been reduced to the cecum. adjacent to cecum (C). At surgery, ileocecal valve.
air-filled with
distended the
setting
bowel of high-
grade
small bowel obstruction. reduction, findings at fluoroscopic and postdecompression radiography included ileocecal valve thickening, cecal wall edema, and thickening of terminal ibeum (Fig 4). Of the 10 intussusceptions that were irreducible with air enema, one was found at surgery to have spontaneousby reduced, and eight were manually reduced after surgery. In the patient with ileoileocobic intussusception, the position of the intussusception indicated with fluoroscopy (15 cm proximal to the ileocecab valve) was verified at surgery, and a difficult manual reduction resulted in minor serosab tears. No areas of occult perforation, necrosis, or pathologic lead mass were discovered during surgery. In 100 consecutive patients with intussusceptions treated with hydrostatic enemas, reduction was successful in 55. After
Figure 4. Spot radiograph obtained after pneumatic reduction of an intussusception. Thickened, edematous ileocecal valve (solid arrows) and thickened terminal ileum (open arrows) with narrowed lumen are evident.
less clear in reductions associated with small bowel dilatation and obstruction. Reduction of the ileoileocolic intussusception was documented from the transverse colon, through the ibeocecal valve, and as it progressed in the terminal ileum until movement
eum (Fig susception Volume
ceased
in the
3). Movement was visible 181
#{149} Number
terminal
of the through 1
il-
intusthe
DISCUSSION The number in findings of pends on two the physician and experience terpreting the nab radiographs.
of enemas that result intussusception defactors: experience of examining the patient of the radiologist inconventional abdomiWith the simplicity
intussusception
reduction
with
air
insufflation: copious reflux of air into the small bowel and disappearance of the soft-tissue mass. If pseudoreduction or recurrence seems evident, air enema can easily be repeated. Our data also confirm the wide variability in pressures required to reduce intussusceptions. Pressure required for reduction had no direct correlation with duration of symptoms. Factors that may contribute to higher reduction pressures include ileocecal valve competence, lymphoid hyperplasia of the terminal ileum, terminal ileab and ibeocecal valve edema, and edema of the intussusceptum. Recurrent intussusception may be diagnosed with as little as 20-30 mm Hg. This is important information for surgeons and radiologists; we have had cases in which a patient has been operated on for intussusception and has undergone subsequent appendectomy, and postoperative symptoms possibly due to recurrent intussusception have developed. A bow-pressure air enema can be safely performed to either confirm or exclude the diagnosis of postoperative intussusception; if the examination is confirmatory, surgicab rather than pneumatic therapy may be indicated. Once the colon is distended with air, movement of the intussusception usually occurs with low pressure (mean pressure, 56 mm Hg). During movement, pressure may drop as more of the colon becomes distended. Insufflation should be continued at a pressure effective for movement of Radiology
#{149} 171
the intussusceptum. We have encountered mild resistance during reduction in areas of cobonic tortuosity. In straight areas of bowel such as the transverse colon and ascending colon, the intussusception usually reduces rapidly and with little resistance. In areas of resistance, pressures of 80-90 mm Hg are often needed to continue movement of the intussusceptum. The area of greatest resistance is the ileocecal valve. Resistance to reduction is common in this area, and further insufflation, to pressures of 100 mm Hg or higher, is often necessary for complete reduction. The intussusception reduction rate (87%) with air insufflation at our institution (Children’s Hospital Medical Center, Cmcinnati) is greater than our previous reduction rate with hydrostatic methods (55%). An important finding that we have observed and are now studying more carefully is the dynamic nature of intussusception reduction in a nonsedated patient. During reduction with the hand-pump technique, the intracobonic pressure varies widely with the Valsalva maneuver. With a tight anal seal, dynamic intracobonic pressure changes can be carefully monitored. In the past, we would not allow intracobonic pressure beyond 120 mm Hg, even during the Valsalva maneuver. Preliminary experimental data suggest that the Vabsalva maneuver protects the bowel from perforation and facilitates intussusception reduction (9). Thus, the pressure limit of 120 mm Hg is for “resting” maximum pressure; intracobonic pressures during patient straining (Valsalva maneuver) may be higher. A number of postulates with regard to speed and efficacy of air enemas can be formed on the basis of results of our study. First, air can fill the co-
172
#{149} Radiology
bon, as well intussusceptum air initiates does
as dissect and movement
liquid,
because
between the intussuscepiens; faster than of the
compress-
ible nature of gas. Second, more effective mean intracobonic pressure can be maintained with air than with liquid because air is insufflated via a pump with a one-way valve, prohibiting reverse flow. Liquid enemas, on the other hand, are administered with an open system that allows reverse flow of liquid and hence cobonic decompression in the nonsedated, straining child. Morbidity in the event of perforation has been less with the air enema than with hydrostatic enemas (1,2,10). If perforation occurs during air enema, tension pneumoperitoneum is immediately decompressed prior to surgical therapy (1-3,9). Moreover, experimental results confirm that perforation during air enemas produces much less fecal contamination of the peritoneum than does perforation during enemas performed with barium or water-soluble contrast medium (9). Difficulty in visualization of small bowel air reflux has been noted in cases
of small
bowel
obstruction
(Fig
3) can
be
Acknowledgments: We thank the pediatric radiology faculty, fellows, and technologists in the Department of Radiology, without whose support and enthusiasm this work would not have been possible. In particular, we thank Janet Beerman, RT; Sam Auringer, MD; Kathy Garrett, MD; Paula Shultz, MD; and Jane Matsumoto, MD.
References 1.
2.
3.
4.
demonstrated
Jinzhe Z, Yenxia W, Linchi W. Rectal inflation reduction of intussusception in infants. J Pediatr Surg 1986; 21:30-32. Guo JZ, Ma XY, Thou QH. Results of air pressure enema reduction of intussusception: 6,396 cases in 13 years. J Pediatr Surg 1986; 21:1201-1203. Gu L, Alton DJ, Daneman A. Intussusception reduction in children by rectal insufflation of air. AJR 1988; 150:1345-1348. Phelan E, deCampo JF, Malecky G. Companson of oxygen and barium reduction of ileocolic intussusception. AJR 1988; 150: 1349-1352.
5.
6.
(10).
We have had similar experience and note that ileocecal reflux of air, although more difficult to see, can indeed be visualized in this setting. In addition, intussusception can be readily visualized throughout the course of reduction, even with associated small bowel obstruction. Cecal wall edema, thickened ileocecal valve, terminal ileal thickening with luminal narrowing (Fig 4), and ileoileal components of ileoileocolic intussusceptions
childhood intussusception at our institution; we believe it is the fastest, safest, and most effective method for radiobogic treatment of this common childhood disorder. #{149}
7.
8.
Miles SG, Cumming WA, Williams JL. Pneumatic reduction of ileocolic intussusception in children. Pediatr Radiol 1988; 18:3-4. Bisset GS, Kirks DR. Intussusception in infants and children: diagnosis and therapy. Radiology 1988; 168:141-145. Shiels WE, Bisset GS, lUrks DR. Simple device for air reduction of intussusception. Pediatr Radiol 1990; 20:472-474. Hedlund CL, Johnson FJ, StrifeJL. Ileocolic intussusception: extensive reflux of air preceding pneumatic reduction. Radiology
1990; 174:187-189. 9.
10.
Shiels WE, Keller GL, Ryckman FR, Dougherty C, Specker BL, Kirks DR. Juvenile colonic perforation: experimental results and clinical applications. Presented at International Pediatric Radiology 1991 meeting, Stockholm, May 1991. Stringer DA, Em SH. Pneumatic reduction: advantages, risks, and indications. Pediatr Radiol 1990; 20:475-477.
readily with air enemas. The air enema is readily learned and easily performed. Air insufflation has replaced the hydrostatic enema for the diagnosis and treatment of
October1991
E. Shiels
II, DO
#{149} Constance
K Maves,
MD
#{149} Gary
L. Hedlund,
DO2
#{149} Donald
R. lUrks,
MD
Air Enema for Diagnosis and Reduction of Intussusception: Clinical Experience and Pressure Correlates’ Air enema was used for exclusion, diagnosis, initial movement, and complete reduction of intussusception in 186 pediatric patients. Average pressure needed for initial movement of intussusception was 56.5 mm Hg average maximum pressure of 97.8 mm Hg was required for cornplete reduction. Average fluoroscopy time required for intussusception reduction was 94.8 seconds; an average of 41.8 seconds was required to exdude intussusception. Intussusceplion was diagnosed in 75 patients, and reduction was accomplished in 65 (87%). Of 100 consecutive patients that underwent hydrostatic reduction of intussusception at the authors’ institution, reduction was successful in 55. Compared with hydrostatic enerna, air enema involves shorter fiuoroscopy time and lower radiation dose to the patient. Air enema is safe and effective for diagnosis and treatrnent of intussusception in infants and children and has replaced hydrostatic enema for such procedures at the authors’ institution.
I
several
N
has
terms:
Children,
gastrointestinal
tract
the
the
enema
air
hydrostatic
en-
ema for evaluation and treatment of intussusception in children (1-5). Since the reintroduction of the air enema for childhood intussusception, a variety of techniques for the procedure have been described (1-7). Although maximum pressure settings, success
rates,
and
complications
have
been commented on, to our knowledge, data on actual pressures and fluoroscopy time in a large series of pediatric
patients
have
not
been
avail-
able. We report pressure data and experience in a series of 186 patients in whom air enema was used to exclude, diagnose, and treat childhood intussusception. In addition, we evaluated fluoroscopic times, fluoroscopic findings, and success rate with the air enema.
MATERIALS From mas
July
were
pediatric Index
institutions,
replaced
AND
patients
in
who
1990,
186
were
air ene-
consecutive
first seen
with
Infants, gastrointestinal tract #{149} Gastrointestinal tract, interventional procedure, 74.1275, 75.1282 #{149} Intussusception, 72.73, 72.73 Radiology
2 months
181:169-172
to 15 years.
The duration blood at rectal
I From the Department of Radiology, Children’s Hospital Medical Center, and the Departments of Radiology and Pediatrics, University of Cincinnati College of Medicine, Cincinnati. From the 1990 RSNA scientific assembly. Received December 3, 1990; revision requested February 21, 1991; revision received May 7; accepted May 29. Supported in part by a Research and Educational Fund grant of the Society for Pediatric Radiology. Address reprint requests to W.E.S., Department of Radiology (HSHL-X), Pediatric Imaging, Walter Reed Army Medical Center, Washington, DC 20307. 2 Current address: Department of Radiology, Pediatric Imaging, Wilford Hall Air Force Medical Center, Lackland Air Force Base, Texas.
C RSNA,
1991
of symptoms, examination,
presence of success or fail-
ure of the enema, and number of enema attempts were recorded. The following data were also collected: pressure required for air reflux into the small bowel in patients without intussusception; pressure required for initial movement of the intussusceptum; and maximum pressure
reached (with or without lion). “Average” pressure the average used during Surgical
prior
complete reducdata represent
maximum (peak) the procedures. consultation
to air enemas.
was
Clinical
catheters,
scribed
techniques
system
consists
handhebd connected tubing
by means of previously de(7). This air reduction of a reusable, one-piece,
pressure gauge to a disposable system.
The
tubing
tem permits simultaneous with one hand, pressure fluoroscopic monitoring
Anal air seal with was
obtained
pressure
nonballoon
catheters
of the buttocks
and manual compression or with a rubber disk and tape plug applied to the external surface
of the
uously
monitored
anus.
Pressures
were
during
the
contin-
fluoroscopir
As a general rule, insufflation was limited to a maximum of 120 mm Hg, which has been recommended by other investigators (1,3,6). In some cases, at the discretion of the supervising fellow or faculty, higher pressures were used during performance of a Vabsalva maneuver with the patient straining. Operators performed a maximum of three attempts to reduce the intussusception. For each attempt, maximum pressure was maintained
for no longer
A sample
or radiobogic
than
number
permanently
archived
was
copy
times
represent
ning the procedure of intussusception
analyzed
the
time
for
from
to complete or, in patients to the
end
or water-soluble
Air enemas
enemas
performed
was
compared with in 100 consecutive
begin-
reduction without
of copious
small bowel air reflux. The reduction rate achieved achieved (barium
seda-
3 minutes.
of cases that had been
total fluoroscopic time required for excbusion or successful reduction of intussusception. These video recordings were available for 34 patients with intussusceplion and 11 patients in whom there was no evidence of intussusception. Fluoros-
intussusception, conducted
without
has an
air insufflation assessment, and (7).
by taping
enemas
performed
system
enema tip, clear tubing, protective ifiter, and trigger-positioned stopcock for instantaneous colonic decompression. The sys-
evidence of peritonitis and pneumoperitoneum were absolute contraindications to enema in patients with intussusception. were
and insufflator enema tip and
pressure
clinically suspected intussusception. Intussusception was diagnosed in 75 patients. Of the 75 patients, 53 were male and 22 were female. For the 186 patients, the average age was 19.3 months with a range of
1991;
boon
procedure.
METHODS
1988 to October
performed
tion of the patient. Radiologists from all levels of training and expertise (residents at all bevels of training, fellows, and faculty) performed air enemas; fellows and faculty supervised all procedures. Air enemas were performed with an air reduction system (Shiebs Intussusception Air Reduction System; Custom Medical Products, Maineville, Ohio) and nonbal-
with
air
the rate hydrostatic
contrast
for treatment
media) of intus-
169
a.
b.
Figure 1. (a, b) Spot radiographs obtained during intussusceptum (I) is identified in right transverse sure. Reduction required 100 mm Hg of pressure. soft-tissue mass.
susception
at our
before drostatic
contrast
the
bag
medium
3 minutes,
attempts
per
(1985-1988)
to the use of air. For hy-
enemas,
high,
than
institution
conversion
was
was
and no more patient
were
held
held
3 feet no
than
longer
three
made.
RESULTS Average to exclude
seconds four
fluoroscopy
time
required
was
41.8
seconds). The times for intus-
recorded
susception exclusion were and 17 seconds. In patients cessfub
5, 6, 10, with sucreduction, the time was 94.8
intussusception
average
fluoroscopy
(range, 14-300 seconds). five shortest fluoroscopy times corded for complete reduction
The
seconds
re-
were 14, 18, 20, 28, and 30 seconds. In these cases, 14 of 34 (41%) of the reductions were complete in less than 1 minute; in 24 of 34 (71%), reduction was completed in less than 2 minutes of fluoroscopy. In the 111 patients in whom intussusception
was
excluded,
pressure
of 60.9 mm
for
bowel
small
reflux.
an
Hg was Air
average
required
refluxed
through the ileocecab valve with as little as 20 mm Hg of pressure. In the 75 patients treated for intussusception, the average pressure required for initial movement of the intussusceptum was 56.5 mm Hg (range, 20-100 mm Hg). Complete reduction required an average pressure of 97.8 mm Hg (range, 30-160 mm Hg). It should be noted that 34% (22 of 65) of the reductions were com170
#{149} Radiology
pneumatic reduction of ileocolic intussusception. colon. (b) Intussusceptum (I) has been reduced (c) Postreduction radiograph demonstrates free
(a) At 20 mm Hg insufflation pressure, to ileocecal valve with 80 mm Hg of presflow of air into ileum and disappearance
of
pleted with a maximum of 90 mm Hg of pressure or less and 1 1 % (seven of 65) were successful with 60 mm Hg or less. An average of 1.7 attempts was necessary for complete reduction (range, 1-3 attempts). Additional attempts frequently
intussusception (range, 5-145
shortest
C.
were
made
because
of air
leaks prior to the use of the external anal seal system. No perforations or other complications resulted from air enemas.
Maximum
corded
reflected
required
for
pressures
maximum
a specific
re-
pressure
change
such
initial movement of intussusceptum or complete reduction through ileocecal
valve
and
terminal
as
the
ileum.
Pneumatic intussusception reduction was dynamic; pressures changed during the Valsalva maneuver (patient straining) and movement of the intussusceptum. Reduction of the intussusception through the ibeocecal valve consistently required the highest and most sustained pressures. The air enema was positive for intussusception in 75 of 186 patients (40.3%), for a positivity ratio of one positive enema for every 1.48 negative
enemas.
was
successful
Pneumatic
reduction
in 65 of the
(87%) with intussusception. 75 intussusceptions, 74 were
75 patients Of
these
Figure
2. Spot radiograph obtained in a child with ileocolic intussusception with a rectal mass. The intussusceptum is clearly outlined in the rectosigmoid colon. Complete reduction required 120 mm Hg of pressure.
plete
intussusceptum
reduction)
(8)
were
noted;
reduction
was
complete
subsequent
in
all four
cases
of intussusception
were
reduced.
Observations
ity
or back
tion
and
ties
during
or
All three
in the
regarding
of visibility
other
the
associated radiographs
abnormalion spot were rewere
ileocolic and one was ileoileocolic. The ileoibeocobic intussusception was reduced from the transverse colon to a final point of irreducibility 15 cm proximal to the ileocecal valve. Four pseu-
readily visible. Intussusceptions be followed throughout the
doreductions the ileocecal
disappeared was visible
(reflux of air valve preceding
through com-
the
were when
rectum
visibil-
and
All intussusceptions
sequence
rectum
of intussuscep-
fluoroscopy
overhead
corded.
cases.
could reduction
(Fig 1) from as far distal (Fig 2). Pseudoreductions
considered complete the ibeocecab mass (8). Small in all cases;
as
reductions completely bowel reflux visibility was
October
1991
a.
b.
Figure 3. Reduction
(b) Oblique the
and speed of the air enema, an experienced radiologist can exclude the diagnosis of intussusception in as little as 5-10 seconds of fluoroscopy time, and likewise reduce an uncomplicated intussusception in as little as 14-30 seconds. Because of the ease and rapidity of air insufflation, surgeons have a lower threshold for obtaming the examination in cases in which the diagnosis of intussusception is suspected. A bower radiation dose to the patient is a result of short fluoroscopy time and lower kilovolt peak and milliamperes required for air studies, compared with those required for barium or water-soluble contrast enemas (4). Our data show marked variation in the pressure required to exclude intussusception. We found that high insufflation pressures often are not required to exclude intussusception, which is demonstrated by our success with as little as 20-30 mm Hg. There are two criteria for complete
ileoileal
Spot radiographs obtained during reduction of could not be completed. (a) Intussusceptum (I) view shows distal ileoileal intussusceptum (I) component was located 15 cm proximal to the
overlying associated
an ileoileocolic intussusception. has been reduced to the cecum. adjacent to cecum (C). At surgery, ileocecal valve.
air-filled with
distended the
setting
bowel of high-
grade
small bowel obstruction. reduction, findings at fluoroscopic and postdecompression radiography included ileocecal valve thickening, cecal wall edema, and thickening of terminal ibeum (Fig 4). Of the 10 intussusceptions that were irreducible with air enema, one was found at surgery to have spontaneousby reduced, and eight were manually reduced after surgery. In the patient with ileoileocobic intussusception, the position of the intussusception indicated with fluoroscopy (15 cm proximal to the ileocecab valve) was verified at surgery, and a difficult manual reduction resulted in minor serosab tears. No areas of occult perforation, necrosis, or pathologic lead mass were discovered during surgery. In 100 consecutive patients with intussusceptions treated with hydrostatic enemas, reduction was successful in 55. After
Figure 4. Spot radiograph obtained after pneumatic reduction of an intussusception. Thickened, edematous ileocecal valve (solid arrows) and thickened terminal ileum (open arrows) with narrowed lumen are evident.
less clear in reductions associated with small bowel dilatation and obstruction. Reduction of the ileoileocolic intussusception was documented from the transverse colon, through the ibeocecal valve, and as it progressed in the terminal ileum until movement
eum (Fig susception Volume
ceased
in the
3). Movement was visible 181
#{149} Number
terminal
of the through 1
il-
intusthe
DISCUSSION The number in findings of pends on two the physician and experience terpreting the nab radiographs.
of enemas that result intussusception defactors: experience of examining the patient of the radiologist inconventional abdomiWith the simplicity
intussusception
reduction
with
air
insufflation: copious reflux of air into the small bowel and disappearance of the soft-tissue mass. If pseudoreduction or recurrence seems evident, air enema can easily be repeated. Our data also confirm the wide variability in pressures required to reduce intussusceptions. Pressure required for reduction had no direct correlation with duration of symptoms. Factors that may contribute to higher reduction pressures include ileocecal valve competence, lymphoid hyperplasia of the terminal ileum, terminal ileab and ibeocecal valve edema, and edema of the intussusceptum. Recurrent intussusception may be diagnosed with as little as 20-30 mm Hg. This is important information for surgeons and radiologists; we have had cases in which a patient has been operated on for intussusception and has undergone subsequent appendectomy, and postoperative symptoms possibly due to recurrent intussusception have developed. A bow-pressure air enema can be safely performed to either confirm or exclude the diagnosis of postoperative intussusception; if the examination is confirmatory, surgicab rather than pneumatic therapy may be indicated. Once the colon is distended with air, movement of the intussusception usually occurs with low pressure (mean pressure, 56 mm Hg). During movement, pressure may drop as more of the colon becomes distended. Insufflation should be continued at a pressure effective for movement of Radiology
#{149} 171
the intussusceptum. We have encountered mild resistance during reduction in areas of cobonic tortuosity. In straight areas of bowel such as the transverse colon and ascending colon, the intussusception usually reduces rapidly and with little resistance. In areas of resistance, pressures of 80-90 mm Hg are often needed to continue movement of the intussusceptum. The area of greatest resistance is the ileocecal valve. Resistance to reduction is common in this area, and further insufflation, to pressures of 100 mm Hg or higher, is often necessary for complete reduction. The intussusception reduction rate (87%) with air insufflation at our institution (Children’s Hospital Medical Center, Cmcinnati) is greater than our previous reduction rate with hydrostatic methods (55%). An important finding that we have observed and are now studying more carefully is the dynamic nature of intussusception reduction in a nonsedated patient. During reduction with the hand-pump technique, the intracobonic pressure varies widely with the Valsalva maneuver. With a tight anal seal, dynamic intracobonic pressure changes can be carefully monitored. In the past, we would not allow intracobonic pressure beyond 120 mm Hg, even during the Valsalva maneuver. Preliminary experimental data suggest that the Vabsalva maneuver protects the bowel from perforation and facilitates intussusception reduction (9). Thus, the pressure limit of 120 mm Hg is for “resting” maximum pressure; intracobonic pressures during patient straining (Valsalva maneuver) may be higher. A number of postulates with regard to speed and efficacy of air enemas can be formed on the basis of results of our study. First, air can fill the co-
172
#{149} Radiology
bon, as well intussusceptum air initiates does
as dissect and movement
liquid,
because
between the intussuscepiens; faster than of the
compress-
ible nature of gas. Second, more effective mean intracobonic pressure can be maintained with air than with liquid because air is insufflated via a pump with a one-way valve, prohibiting reverse flow. Liquid enemas, on the other hand, are administered with an open system that allows reverse flow of liquid and hence cobonic decompression in the nonsedated, straining child. Morbidity in the event of perforation has been less with the air enema than with hydrostatic enemas (1,2,10). If perforation occurs during air enema, tension pneumoperitoneum is immediately decompressed prior to surgical therapy (1-3,9). Moreover, experimental results confirm that perforation during air enemas produces much less fecal contamination of the peritoneum than does perforation during enemas performed with barium or water-soluble contrast medium (9). Difficulty in visualization of small bowel air reflux has been noted in cases
of small
bowel
obstruction
(Fig
3) can
be
Acknowledgments: We thank the pediatric radiology faculty, fellows, and technologists in the Department of Radiology, without whose support and enthusiasm this work would not have been possible. In particular, we thank Janet Beerman, RT; Sam Auringer, MD; Kathy Garrett, MD; Paula Shultz, MD; and Jane Matsumoto, MD.
References 1.
2.
3.
4.
demonstrated
Jinzhe Z, Yenxia W, Linchi W. Rectal inflation reduction of intussusception in infants. J Pediatr Surg 1986; 21:30-32. Guo JZ, Ma XY, Thou QH. Results of air pressure enema reduction of intussusception: 6,396 cases in 13 years. J Pediatr Surg 1986; 21:1201-1203. Gu L, Alton DJ, Daneman A. Intussusception reduction in children by rectal insufflation of air. AJR 1988; 150:1345-1348. Phelan E, deCampo JF, Malecky G. Companson of oxygen and barium reduction of ileocolic intussusception. AJR 1988; 150: 1349-1352.
5.
6.
(10).
We have had similar experience and note that ileocecal reflux of air, although more difficult to see, can indeed be visualized in this setting. In addition, intussusception can be readily visualized throughout the course of reduction, even with associated small bowel obstruction. Cecal wall edema, thickened ileocecal valve, terminal ileal thickening with luminal narrowing (Fig 4), and ileoileal components of ileoileocolic intussusceptions
childhood intussusception at our institution; we believe it is the fastest, safest, and most effective method for radiobogic treatment of this common childhood disorder. #{149}
7.
8.
Miles SG, Cumming WA, Williams JL. Pneumatic reduction of ileocolic intussusception in children. Pediatr Radiol 1988; 18:3-4. Bisset GS, Kirks DR. Intussusception in infants and children: diagnosis and therapy. Radiology 1988; 168:141-145. Shiels WE, Bisset GS, lUrks DR. Simple device for air reduction of intussusception. Pediatr Radiol 1990; 20:472-474. Hedlund CL, Johnson FJ, StrifeJL. Ileocolic intussusception: extensive reflux of air preceding pneumatic reduction. Radiology
1990; 174:187-189. 9.
10.
Shiels WE, Keller GL, Ryckman FR, Dougherty C, Specker BL, Kirks DR. Juvenile colonic perforation: experimental results and clinical applications. Presented at International Pediatric Radiology 1991 meeting, Stockholm, May 1991. Stringer DA, Em SH. Pneumatic reduction: advantages, risks, and indications. Pediatr Radiol 1990; 20:475-477.
readily with air enemas. The air enema is readily learned and easily performed. Air insufflation has replaced the hydrostatic enema for the diagnosis and treatment of
October1991
