- Email: [email protected]
Endoscopy of the Ileocecal Area
GASTHOENTEHOLOGY 65:403-411, 1973 Copyright© 1973 by The Williams & Wilkins Co.
Vol. 65, No. 3 Printed in U.S.A.
ENDOSCOPY OF THE ILEOCECAL AREA K. NAGASAKO, M.D., AND T. TAKEMOTO, M.D.
Th e Institut e of Gastro enterology, Toky o Wom en's Medical College , Toky o, Japan
Advances in the field of fiberoptics have resulted in the development of long colonoscopes. This instrument has enabled us to observe the ileocecal area. In 125 cases, a fibercolonoscope was inserted into the ileocecal area under visual control. The last 100 cases were used for this study. The technique of colonoscope insertion is outlined. The effect of the loop formation of the scope on its insertion is described. The ileocecal sphincter was observed in 81% of these 100 cases, and the terminal ileum in 66%. The normal endoscopic features of the ileocecal sphincter, the root of the appendix, the cecum, and the terminal ileum are described. It appears that in the living subject the ileocecal sphincter and the root of the appendix were not constant in form but manifested various forms according to intestinal motility. The terminal ileum can be classified into four groups according to the superficial change resulting from follicular hyperplasia. In recent years great progress has been tion revealed that the degree of follicular made in the fiberendoscopic examination of hyperplasia varied inversely with age. the gastrointestinal tract, including the Materials and Methods ileocolic junction. The technique of insertInstrument ing the fiberscope into the ileocecal area was reported by us 1 and by other Japanese A fibercolonscope (FCS , Machida Endoauthors. 2 • 3 It is possible to insert the fiber- scope Co., Ltd., Tokyo, Japan) was used in scope into the ileocecal area in about 90% this study. The total length is 2135 mm and of the cases. Previously, it was very the effective length is 1880 mm. The rigid difficult to observe the ileocecal sphinc- portion of the tip of the scope is 17 mm in length ter in its natural position. Therefore, and 12 mm in diameter . The FCS is a forwardthere has been controversy concerning viewing scope with a visual field of 60°. Special the form and function of the ileocecal consideration was given to the function of the sphincter. 4 Fibercolonoscopic observation tip ; besides the up and down movement , the tip can be flexed 120° both to the right and the left. of the ileocecal sphincter revealed that the Illumination was obtained with the external sphincter moved and took various forms cool light source Machida: RX-500. according to the movement of the terminal Preparation for the Examination ileum. It seemed that the ileocecal sphincter regulated the flow of the ileal contents The examination was carried out in the into the colon. The root of the appendix afternoon. No breakfast or lunch was allowed on also changed its form according to the the day of the examination. Castor oil (25 ml) appendiceal movement. The terminal was given orally in the early morning. An ileum is characterized by its abundant enema of 500 or 1000 ml of warm water was lymph tissue. Fibercolonoscopic observa- given at 10 and 11 AM. Previously, 20 mg of Received May 1, 1972. Accepted April 14, 1973. Address requests for reprints to: Dr. Kou Nagasako, Tokyo Women 's Medical College, 10 Kawadacho Shinjuku-ku, Tokyo, Japan. 403
hyoscin-N-butylbromide (Buscopan) were used intramuscularly. However, we now believe that such a drug is not necessary. Diazepam (Horizan), 30 mg, was injected intramuscularly to apprehensive patients 5 min prior to the examination .
404
NAGASAKO AND TAKEMOTO
T echnique of Colonoscopy In most cases the examination was carried out with the help of tluoroscopy on the X-ray table to facilitate the insertion of the fiberscope , but it was also possible to insert the FCS into the ileocecal area without the help of fluoroscopy. 5 A scope was introduced directly into the anus and pushed to the proximal colon while the intestinal lumen was observed. The passage through the rectum is usually easy . The sigmoid colon is one of the most difficult parts to bypass because of the long mesocolon. Its length and shape vary considerably. The colonoscope can make one or more loops during its passage through the sigmoid colon , depending on the anatomical structure of that segment (fig. 1) . The descending colon is easy to bypass because it is usually straight and is fixed retroperitoneally. When the tip of the scope is beyond the splenic flexure the loops of the sigmoid colon can be straightened by using a "pull-the-scope technique A." In this technique the scope is pulled by fixing the tip of the scope at the splenic flexure or at a more proximal point in the transverse colon by the angle mechanism (fig. 2A). The transverse colon also has a wide mesocolon, and the scope makes a loop or a downward (concave) curve. The loop or curve of the transverse colon can be straightened by "pull-the-scope technique B." The lower part of the scope in the descending loop or curve in the middle of the transverse colon is pushed manually towards the
@ pull · the - scope @ pu i t -t he-s co p ~
Vol. 65, No.3
diaphragm while the scope is pulled out of the anus (fig. 2B). The final configuration, when the tip of the scope is at the proximal ascending colon, is usually a simple convex curve. However, in some cases it is impossible to straighten the loops of the transverse and/or sigmoid colon. Recently, we have been concerned about the damage, caused by irradiation, to the glass fibers of the fiberscope. Thus, it is better to minimize the duration of fluoroscopy during insertion, or to eliminate fluoroscopy altogether. 5 In our previous report, 1 we described three types (type I, II , and III) of the fiberscopic configuration of the transverse colon. When the loop at the sigmoid colon was taken into consideration, we reclassified types, I, II, and III into types A, B, C, and D. Type A (no loop; previous type D; type B (loop at the sigmoid colon); type C (loop or downward curve at the transverse colon; previous type II or Ill); type D (loop at the sigmoid colon pi us loop or downward curve at the transverse colon) (fig. 3). When the tip of the scope reaches the proximal ascending colon, the ileocecal sphincter is examined. Since the FCS is a forward-viewing scope, a lateral view of the ileocecal sphincter is obtained first. When the sphincter shows a papillary form the scope is rarely advanced beyond the sphincter since the orifice is narrow or completely closed. While the sphincter is being observed, the orifice of the papillary valve gradually opens and begins to change into labial
m11:thod A metho d B
FIG. 1. Shematic illustration of process of fibercolonoscopic (FCS) insertion.
405
ENDOS COPY OF THE IL EOCECAL AREA
September 1973
RESOLUTION OF THE LOOP AT THE SIGMOID COLON
A
- DIRECTION OF THE FORGE ( PULL )
RESOLUTION OF THE •HANGING-DOWN• OF THE FCS AT THE TRA'iSVERSE
COLON
1P---JP---? .'{1-- Y---'?---? I
B
-
DIRECTION OF THE
FORCE (PULL)
=t
DIRECTION OF THE
FORCE
I
THE TIP OF THE SCOPE IS BEYOND THE
ll THE TIP Of THE SCOPE IS BEFORF. THE
FLEXURA HEPATICA FLEXURA
HEPATICA
FIG. 2. A, Pull-the-scope technique A; B, Pull-the-scope technique B.
SCOPIC CONFIGURATION
VALVE OBSERVED
APPENDICEAL ROOT OBSERVED
A
C)
51
45
( 90 '1.)
9
( 1 8'/,)
B
(()
11
8
( 7 3 '1.)
5
( 4 5 '/,)
c(C)) D
~
37
( 7 4 '/,)
6 (55'/,)
or
~
27
23
( 85'1.)
6
( 2 2 '1.)
21
or
WJ
11
5
( 45'1.)
1
( 2 5 '/,)
1
100
81
( 81 '1.)
21
( 2 1 '/,)
66
TOTAL
FIG.
ILEUM OBSERVED
( 7 8'/,)
(
9 '/,)
( 66'/,)
3 . Scopic configuration and observation of the ileocecal area .
406
Vol . 65, No.3
NAGASAKO AND TAKEMOTO
form . In the latter shape, the orifice appears to be open, or opens easily. With proper control of the angle mechanism, the tip of the scope can be inserted into the terminal ileum when the orifice is opened to its maximum diameter. Manual assistance through the abdominal wall may facilitate the insertion. If the sphincter remains closed it can be forced open by the biopsy forceps. Once the scope is inserted into the ileum, it can easily be advanced about 20 to 50 em beyond the ileocecal sphincter. The technique of scope insertion into the ileum is shown in figure 4.
Observation Up to November 1971, the fibercolonoscope was inserted into the ileocecal area in 125 cases. Colonoscopy was performed if lower abdominal symptoms were present, or during a periodic health examination. The initial 20 cases were excluded from the statistics because of the lack of systematic observation for analysis. Five more cases of large cancer of the cecum were also excluded because the cancer hindered a thorough observation of the ileocecal sphincter and the root of the appendix. Therefore, only the remaining 100 cases of fibercolonoscopy were analyzed. As shown in figure 3, we could visualize the ileocecal sphincter in 81% of the cases, the root of the appendix in 21%, and the terminal ileum in 66%, when the tip of the scope reached the ileocecal area.
Ileocecal Sphincter We succeeded in observing the ileocecal sphincter in 81% of those cases. The main
reason for our failure to observe the sphincter was the poor preparation of the ileocecal area (8 cases) since this area was one of the most difficult parts to clean. The success rate with multiple curves and loops was only 50% of that obtained with only one loop or with no loops at all.
Root of the Appendix The root of the appendix was observed in only 21% of the cases. This rate was too low, regardless of the configuration of the inserted scope. We might have neglected to look for the appendiceal root, since our chief concern at the ileocecal area was the ileocecal sphincter and the terminal ileum. Thus, in the future, we will have to be more cautious. Terminal Ileum The terminal ileum was observed in 66% of the patients. As in the observation of the ileocecal sphincter, a single loop at the sigmoid or the transverse colon did not hinder the insertion of the scope into the terminal ileum to any noticeable degree. However, it was very difficult to observe the terminal ileum in cases where two loops remained. Endoscopic Appearance of the Ileocecal Area Cecum. The cecum is the pouch of colon below the entrance of the small intestine. Since the cecum has a blind end, its folds differ from other parts of the large intestine. The folds are not always circular as in
COLONO· SCOPE
SHIFT of tho ILEOCECAL SPHINCTER PAPILLARY or INTERMEDIATE
LABIAL
FIG. 4. Insertion of the fibercolonoscope into the terminal ileum .
September 1973
ENDOSCOPY OF THE IL EOCECAL AREA
other parts of the colon. The folds of the cecum , especially near the blind end, are often straight and short, and the parts between the folds, to some extent, resemble diverticula. Another characteristic feature of the cecum is "cecocolic contraction," which will be referred to later. Ileocecal sphincter. The ileocecal sphincter is the junctional part of the ileum and the colon, and is thought to regulate the flow of the ileal contents into the colon . Hence, the term "ileocecal sphincter" is more appropriate than "ileocecal valve." 4 When the tip of the scope reached the lower ascending colon, the sphincter could easily be observed at the medial aspect of t he border between the colon and the cecum. In some instances, it could be detected as just a slight protrusion with a reddish surface. In looking for the ileocecal sphincter, the cecocolic contraction must be kept in mind. Sometimes the cecum contracts strongly near the ileocecal sphincter and the contracted part may resemble the ileocecal sphincter. The contracted part represents the cecocolic contraction. It is sometimes difficult to differentiate such contraction from the true ileocecal sphincter. The root of the appendix, as it is in a protruded form , may also resemble the ileocecal sphin cter. The true ileocecal sphincter was confirmed by observing the ileal mucosa beyond the suspected "sphincter." We classified the endoscopic appearance of the ileocecal sphincter as follows: Labial form . Two approximately parallel labia are detectable, and a frenulum , or frenula , exists at the junction of the two labia. It is not so protruded and appears rather flat (fig. 5) . Papillary form. There is a papillary or a domelike protrusion into the colon canal. The labia are lumped together and cannot be positively recognized as in the case of the labial form. Sometimes the protrusion is so extreme that it resembles a semipedunculated polyp (fig. 6). Intermediate form. Every possible form between the papillary and labial form is included. The protrusion is not as promi-
407
FIG. 5. Labial sphincter. The upper half represents the sphincter. The small dark part in the middle of the figure is the mouth of the sphincter. The frenulum is seen at the right lower part.
nent as in the papillary form, and the summit is usually flat. Its lateral figure appears somewhat trapezoid (fig. 7) . Movement of the Ileoc ecal Sphin cter
DiDio and Anderson 6 stated that the ileocecal sphincter was classified into two forms : labial and papillary . The labial form was common in vitro arid the papil lary form was prevalent in vivo . However, the fibercolonoscopic observation revealed that the shape of the ileocecal sphincter was by no means constant. In the living subject, the ileocecal sphincter of the same individual changed and showed both the labial and papillary forms taking an intermediate form en route. Usually the ileocecal sphincter showed labial or intermediate form when the terminal ileum was in a hypokinetic state . As the ileal movement reached the terminal segment, the ileocecal sphincter protruded and the labia of the sphincter lumped together showing the papillary form. The ileal contents flowed into the colon when the sphincter was papillary in form. The flow was usually slow and rather intermittent. The ileal contents did not appear to flow rapidly or heavily into the colon. There were cases of papillary sphincter
408
NA GASAKO AND T A KEMOTO
Vol. 65, N o.3
FIG. 7. Intermediate s phincter , th e upper bright half represents the latera l aspect of th e sphincter.
sphincter remained papillary for more than 5 min. During that period the ileal contents flowed intermittently into the colon. The ileocecal sphincter seemed to regulate the flow of the ileal contents into the large intestine by changing its form. The form of the ileocecal sphincter in the same individual is shown in figures 5, 6, and 7. Root of the appendix. The worm-like structure, called the vermiform appendix, was originally the cecal apex . Because of the eccentric growth of the cecum , the base of the appendix arises from the posteriomedial aspect of the fully developed cecum, about 2.5 em below the ileocecal junction . The base of the appendix is almost always FIG. 6. A , Papillary sphincter: the round body retrocecal. 7 In looking for the root of the seen in the upper middl e of the picture is th e appendix, it is more helpful to find the ileosphincter. B, Liquid ilea l contents are seen flowing cecal sphincter first, and then the posterior out of the pa pillary sphinct er. wall of the cecum. The movement of the appendix is conwithout any flow of ileal contents. The lack trolled by the autonomic nervous system. of flow might be due to scanty ileal con- Thus, the root of the appendix takes tents. The papillary protrusion again be- various forms just as the ileocecal sphinccame flat, and the labial structure reap- ter does. The endoscopic appearance of the peared. No contents appeared to flow out root of the appendix, as observed from the of the labial sphincter. The form of the colon canal , was grossly divided into two sphincter was largely due to the movement forms: flat and protruded. In the former of the terminal ileum, but the ileocecal the root of the appendix was flat, and its mouth was open or closed. In the latter, the sphincter seemed to possess the mechanism to maintain its form since it continued root protruded into the cecum and the to be papillary far longer than each rhythm . mouth was closed. In some cases of the of ileal movement. Sometimes the ileocecal protruded root, there was a frenular struc-
S ept ember 1973
ENDOS COPY OF THE ILEOCECAL AREA
ture. It was sometimes difficult to differentiate such a root from the ileocecal sphincter. The root was usually flat when the appendix relaxed, and became protruded when the appendix contracted. Introduction of the biopsy forceps into the appendix to obtain specimens for histological examination was not difficult. The wall of the appendix is thickened by extensive development of lymphatic tissue which forms an almost continuous layer, with many large and small lymphatic nodules. Since the lumen of the appendix often contains masses of dead cells and detritus~ it is difficult to differentiate between normal arid certain pathological conditions. 8 Terminal ileum. The distal segment of the ileum is called the terminal ileum. Its lumen is smaller than that of the colon . In the terminal ileum, the plicae circulares disappear almost entirely. 8 Thus, the distinction between the terminal ileum and the ascending colon is evident endoscopically. In the ascending colon the semilunar folds can clearly be observed. The mucosal surface of the terminal ileum was flat when there was no lymph follicular hyperplasia. Sometimes a villous pattern could clearly be observed. 1 The most characteristic feature of the terminal ileum was the abundance of lymphatic tissue. Hyperplastic lymph follicles could easily be observed by fibercolonoscope. They protruded on the mucosal surface giving a granular appearance. Each follicle varied in size. They ranged from less than 1 mm to 10 mm or more in diameter. A large lymph follicle which resembles a semipedunculated polyp is shown in figure 8. Biopsy specimens revealed such follicles to be of lymphatic origin.'· 9 "Worm-like" soft protuberances were observed at the terminal ileum. They were also proved to be of lymphatic origin; therefore, they were assumed to be Peyer's patches (fig. 9).
However, it was rather rare, by fibercolonoscope, to clearly identify Peyer's patches. Biopsy specimen from each follicle showed lymph follicular origin. The terminal ileum could be divided into four
409
FIG. 8. A large lymph follicl e.
FIG. 9. Peyer's patch .
groups (grades 0 to III) endoscopically for the convenience of description, according to its mucosal appearance. 9 Our definition is as follows: grade 0-either an absence of lymph follicles or, if at all, a: few minute follicles distributed sporadically; grade !-diffusely but sparsely distributed follicles are usually seen, and each follicle is tiny ; grade 11-diffusely and rather densely distributed lymph follicles are seen, conglomerations between follicles are not usually seen , and the individual follicles are smaller than
410
Vol. 65 , No.3
NAGASAKO AND TAKEMOTO
those of grade III; grade III -lymph follicles are diffuse and densely distributed, the individual follicles are generally large, and interfollicular conglomerations or fusions are evident, thereby presenting various and diverse endoscopic features; the covering epithelium sometimes shows hyperemia (fig. 10) . Fifty patients were observed. (Twelve cases of inflammatory diseases with ileocecal involvement and 4 cases of unclean terminal ileum were excluded.) The relationship between the age of patients and the "grade" is shown in figure 11. The following can be derived from the figure. (a) A greater number of patients displayed the grade 0 endoscopic features of the terminal ileum (56%). (b) Lymph follicles of any grade could be observed in the 20-, 30-, and 40-year age groups. However, in the 20-year age group, the grade II lymph follicles prevailed and in the 30- and 40year age ·groups, the grade 0 lymph follicles prevailed. (c) In the age group under 19 years, no cases of the groups 0 and I lymph follicles were found. (d) The extent of the lymph follicular hyperplasia varied grossly in inverse proportion to age. It is safe to say that the grade III lymph follicular hyperplasia is merely a physiological phenomenon in the younger age groups . Conclusions One hundred patients in whom the fibercolonoscope was inserted into the ileocecal area were considered in this study . The most important point of the colonoscope insertion technique is to advance the scope orally while observing the proximal colon, and to use minimal air insufflation, as is the case in rigid sigmoidoscopy. In fibercolonoscopy, unlike rigid sigmoidoscopy, we encountered loop formation. That can be resolved by pull-the-scope techniques, which correspond to pulling the scope at the blind end by sigmoidoscopy. The effect of the inserted scope on the observation of the ileocecal area was studied. One loop at the sigmoid or the transverse colon did not significantly interfere with observation of this area. Therefore, such a loop could be left unresolved. But
FIG. 10. Lymph follicular hyperpl asia of grade III.
Ill
=·· ... :::····· grade
age
10
20
30
40
50
60
70
FIG. 11. Lymph follicles and age.
in cases where two loops remained, observation at the ileocecal area was greatly hindered. The normal endoscopic appearance of the ileocecal area was studied. Both the ileocecal sphincter and the root of the appendix manifested various forms, according to the intestinal motility. The ileocecal sphincter showed labial, papillary, or intermediate form, according to the ileal movement. The form of the ileocecal sphincter was largely dependent on the movement of the terminal ileum. On the other hand, the ileocecal sphincter seemed to have some mechanism to control the flow of the ileal contents into the colon by changing its form. As the ileal movement reached the terminal ileal segment, the ileocecal sphincter protruded showing the papillary form. The ileal contents flowed into the colon when the sphincter was papillary in form. The root of the appendix showed a flat or a protruded form, according to the
September 1973
ENDOSCOPY OF THE ILEOCECAL AREA
appendiceal movement. The terminal ileum could be classified into four groups (grade 0 to III) according to the mucosal appearance derived from the lymph follicular hyperplasia. The extent of the lymph follicular hyperplasia varied greatly in inverse proportion to age. Lymph follicular hyperplasia, which is common in young people, is merely a physiological phenomenon. The ileocecal area was a difficult segment for the endoscopists to examine. However, recent progress in the field of fiberoptics has made endoscopic observation of that area possible. We think that this will contribute immensely to the physiological studies of this segment of the intestinal tract. REFERENCES 1. Nagasako K, Yazawa C, Takemoto T: Observation of the terminal ileum. Endoscopy 3:45-51, 1971
411
2. Tajima T , Toda S: Technique of use of colonofiberscope. Stomach Intestine (Tokyo) 5:1429-1435, 1970 3. Watanabe H , Narasaka T, Uezu J: Colonofiberscopy. Stomach Intestine (Tokyo) 6:1333-1336, 1971 4. Alvarez WC: An Introduction to Gastroenterology. Fourth edition. New York, Paul B. Roeber 5. Nagasako K, Takemoto T: Fibercolonoscopy with· out the help of fluoroscopy. Endoscopy 4:208- 212, 1972 6. DiDio LJA, Anderson MC: The "Sphincters" of the Digesti~e System. Baltimore, Williams & Wilkins Co, 1968 7. Bockus HL: Gastroenterology, vol 2,. Second edition. Philadelphia and London, WB Saunders Co, 1966 8. Bloom W, Fawcett DW: A Textbook of Histology. Eighth edition. Philadelphia and London, WB Saunders Co, 1962 9. Nagasako K, Yazawa C, Takemoto T: Biopsy of the terminal ileum, Gastroenterology 60:823, 1971. Gastrointest Enclose 19:7-10, 1972
Vol. 65, No. 3 Printed in U.S.A.
ENDOSCOPY OF THE ILEOCECAL AREA K. NAGASAKO, M.D., AND T. TAKEMOTO, M.D.
Th e Institut e of Gastro enterology, Toky o Wom en's Medical College , Toky o, Japan
Advances in the field of fiberoptics have resulted in the development of long colonoscopes. This instrument has enabled us to observe the ileocecal area. In 125 cases, a fibercolonoscope was inserted into the ileocecal area under visual control. The last 100 cases were used for this study. The technique of colonoscope insertion is outlined. The effect of the loop formation of the scope on its insertion is described. The ileocecal sphincter was observed in 81% of these 100 cases, and the terminal ileum in 66%. The normal endoscopic features of the ileocecal sphincter, the root of the appendix, the cecum, and the terminal ileum are described. It appears that in the living subject the ileocecal sphincter and the root of the appendix were not constant in form but manifested various forms according to intestinal motility. The terminal ileum can be classified into four groups according to the superficial change resulting from follicular hyperplasia. In recent years great progress has been tion revealed that the degree of follicular made in the fiberendoscopic examination of hyperplasia varied inversely with age. the gastrointestinal tract, including the Materials and Methods ileocolic junction. The technique of insertInstrument ing the fiberscope into the ileocecal area was reported by us 1 and by other Japanese A fibercolonscope (FCS , Machida Endoauthors. 2 • 3 It is possible to insert the fiber- scope Co., Ltd., Tokyo, Japan) was used in scope into the ileocecal area in about 90% this study. The total length is 2135 mm and of the cases. Previously, it was very the effective length is 1880 mm. The rigid difficult to observe the ileocecal sphinc- portion of the tip of the scope is 17 mm in length ter in its natural position. Therefore, and 12 mm in diameter . The FCS is a forwardthere has been controversy concerning viewing scope with a visual field of 60°. Special the form and function of the ileocecal consideration was given to the function of the sphincter. 4 Fibercolonoscopic observation tip ; besides the up and down movement , the tip can be flexed 120° both to the right and the left. of the ileocecal sphincter revealed that the Illumination was obtained with the external sphincter moved and took various forms cool light source Machida: RX-500. according to the movement of the terminal Preparation for the Examination ileum. It seemed that the ileocecal sphincter regulated the flow of the ileal contents The examination was carried out in the into the colon. The root of the appendix afternoon. No breakfast or lunch was allowed on also changed its form according to the the day of the examination. Castor oil (25 ml) appendiceal movement. The terminal was given orally in the early morning. An ileum is characterized by its abundant enema of 500 or 1000 ml of warm water was lymph tissue. Fibercolonoscopic observa- given at 10 and 11 AM. Previously, 20 mg of Received May 1, 1972. Accepted April 14, 1973. Address requests for reprints to: Dr. Kou Nagasako, Tokyo Women 's Medical College, 10 Kawadacho Shinjuku-ku, Tokyo, Japan. 403
hyoscin-N-butylbromide (Buscopan) were used intramuscularly. However, we now believe that such a drug is not necessary. Diazepam (Horizan), 30 mg, was injected intramuscularly to apprehensive patients 5 min prior to the examination .
404
NAGASAKO AND TAKEMOTO
T echnique of Colonoscopy In most cases the examination was carried out with the help of tluoroscopy on the X-ray table to facilitate the insertion of the fiberscope , but it was also possible to insert the FCS into the ileocecal area without the help of fluoroscopy. 5 A scope was introduced directly into the anus and pushed to the proximal colon while the intestinal lumen was observed. The passage through the rectum is usually easy . The sigmoid colon is one of the most difficult parts to bypass because of the long mesocolon. Its length and shape vary considerably. The colonoscope can make one or more loops during its passage through the sigmoid colon , depending on the anatomical structure of that segment (fig. 1) . The descending colon is easy to bypass because it is usually straight and is fixed retroperitoneally. When the tip of the scope is beyond the splenic flexure the loops of the sigmoid colon can be straightened by using a "pull-the-scope technique A." In this technique the scope is pulled by fixing the tip of the scope at the splenic flexure or at a more proximal point in the transverse colon by the angle mechanism (fig. 2A). The transverse colon also has a wide mesocolon, and the scope makes a loop or a downward (concave) curve. The loop or curve of the transverse colon can be straightened by "pull-the-scope technique B." The lower part of the scope in the descending loop or curve in the middle of the transverse colon is pushed manually towards the
@ pull · the - scope @ pu i t -t he-s co p ~
Vol. 65, No.3
diaphragm while the scope is pulled out of the anus (fig. 2B). The final configuration, when the tip of the scope is at the proximal ascending colon, is usually a simple convex curve. However, in some cases it is impossible to straighten the loops of the transverse and/or sigmoid colon. Recently, we have been concerned about the damage, caused by irradiation, to the glass fibers of the fiberscope. Thus, it is better to minimize the duration of fluoroscopy during insertion, or to eliminate fluoroscopy altogether. 5 In our previous report, 1 we described three types (type I, II , and III) of the fiberscopic configuration of the transverse colon. When the loop at the sigmoid colon was taken into consideration, we reclassified types, I, II, and III into types A, B, C, and D. Type A (no loop; previous type D; type B (loop at the sigmoid colon); type C (loop or downward curve at the transverse colon; previous type II or Ill); type D (loop at the sigmoid colon pi us loop or downward curve at the transverse colon) (fig. 3). When the tip of the scope reaches the proximal ascending colon, the ileocecal sphincter is examined. Since the FCS is a forward-viewing scope, a lateral view of the ileocecal sphincter is obtained first. When the sphincter shows a papillary form the scope is rarely advanced beyond the sphincter since the orifice is narrow or completely closed. While the sphincter is being observed, the orifice of the papillary valve gradually opens and begins to change into labial
m11:thod A metho d B
FIG. 1. Shematic illustration of process of fibercolonoscopic (FCS) insertion.
405
ENDOS COPY OF THE IL EOCECAL AREA
September 1973
RESOLUTION OF THE LOOP AT THE SIGMOID COLON
A
- DIRECTION OF THE FORGE ( PULL )
RESOLUTION OF THE •HANGING-DOWN• OF THE FCS AT THE TRA'iSVERSE
COLON
1P---JP---? .'{1-- Y---'?---? I
B
-
DIRECTION OF THE
FORCE (PULL)
=t
DIRECTION OF THE
FORCE
I
THE TIP OF THE SCOPE IS BEYOND THE
ll THE TIP Of THE SCOPE IS BEFORF. THE
FLEXURA HEPATICA FLEXURA
HEPATICA
FIG. 2. A, Pull-the-scope technique A; B, Pull-the-scope technique B.
SCOPIC CONFIGURATION
VALVE OBSERVED
APPENDICEAL ROOT OBSERVED
A
C)
51
45
( 90 '1.)
9
( 1 8'/,)
B
(()
11
8
( 7 3 '1.)
5
( 4 5 '/,)
c(C)) D
~
37
( 7 4 '/,)
6 (55'/,)
or
~
27
23
( 85'1.)
6
( 2 2 '1.)
21
or
WJ
11
5
( 45'1.)
1
( 2 5 '/,)
1
100
81
( 81 '1.)
21
( 2 1 '/,)
66
TOTAL
FIG.
ILEUM OBSERVED
( 7 8'/,)
(
9 '/,)
( 66'/,)
3 . Scopic configuration and observation of the ileocecal area .
406
Vol . 65, No.3
NAGASAKO AND TAKEMOTO
form . In the latter shape, the orifice appears to be open, or opens easily. With proper control of the angle mechanism, the tip of the scope can be inserted into the terminal ileum when the orifice is opened to its maximum diameter. Manual assistance through the abdominal wall may facilitate the insertion. If the sphincter remains closed it can be forced open by the biopsy forceps. Once the scope is inserted into the ileum, it can easily be advanced about 20 to 50 em beyond the ileocecal sphincter. The technique of scope insertion into the ileum is shown in figure 4.
Observation Up to November 1971, the fibercolonoscope was inserted into the ileocecal area in 125 cases. Colonoscopy was performed if lower abdominal symptoms were present, or during a periodic health examination. The initial 20 cases were excluded from the statistics because of the lack of systematic observation for analysis. Five more cases of large cancer of the cecum were also excluded because the cancer hindered a thorough observation of the ileocecal sphincter and the root of the appendix. Therefore, only the remaining 100 cases of fibercolonoscopy were analyzed. As shown in figure 3, we could visualize the ileocecal sphincter in 81% of the cases, the root of the appendix in 21%, and the terminal ileum in 66%, when the tip of the scope reached the ileocecal area.
Ileocecal Sphincter We succeeded in observing the ileocecal sphincter in 81% of those cases. The main
reason for our failure to observe the sphincter was the poor preparation of the ileocecal area (8 cases) since this area was one of the most difficult parts to clean. The success rate with multiple curves and loops was only 50% of that obtained with only one loop or with no loops at all.
Root of the Appendix The root of the appendix was observed in only 21% of the cases. This rate was too low, regardless of the configuration of the inserted scope. We might have neglected to look for the appendiceal root, since our chief concern at the ileocecal area was the ileocecal sphincter and the terminal ileum. Thus, in the future, we will have to be more cautious. Terminal Ileum The terminal ileum was observed in 66% of the patients. As in the observation of the ileocecal sphincter, a single loop at the sigmoid or the transverse colon did not hinder the insertion of the scope into the terminal ileum to any noticeable degree. However, it was very difficult to observe the terminal ileum in cases where two loops remained. Endoscopic Appearance of the Ileocecal Area Cecum. The cecum is the pouch of colon below the entrance of the small intestine. Since the cecum has a blind end, its folds differ from other parts of the large intestine. The folds are not always circular as in
COLONO· SCOPE
SHIFT of tho ILEOCECAL SPHINCTER PAPILLARY or INTERMEDIATE
LABIAL
FIG. 4. Insertion of the fibercolonoscope into the terminal ileum .
September 1973
ENDOSCOPY OF THE IL EOCECAL AREA
other parts of the colon. The folds of the cecum , especially near the blind end, are often straight and short, and the parts between the folds, to some extent, resemble diverticula. Another characteristic feature of the cecum is "cecocolic contraction," which will be referred to later. Ileocecal sphincter. The ileocecal sphincter is the junctional part of the ileum and the colon, and is thought to regulate the flow of the ileal contents into the colon . Hence, the term "ileocecal sphincter" is more appropriate than "ileocecal valve." 4 When the tip of the scope reached the lower ascending colon, the sphincter could easily be observed at the medial aspect of t he border between the colon and the cecum. In some instances, it could be detected as just a slight protrusion with a reddish surface. In looking for the ileocecal sphincter, the cecocolic contraction must be kept in mind. Sometimes the cecum contracts strongly near the ileocecal sphincter and the contracted part may resemble the ileocecal sphincter. The contracted part represents the cecocolic contraction. It is sometimes difficult to differentiate such contraction from the true ileocecal sphincter. The root of the appendix, as it is in a protruded form , may also resemble the ileocecal sphin cter. The true ileocecal sphincter was confirmed by observing the ileal mucosa beyond the suspected "sphincter." We classified the endoscopic appearance of the ileocecal sphincter as follows: Labial form . Two approximately parallel labia are detectable, and a frenulum , or frenula , exists at the junction of the two labia. It is not so protruded and appears rather flat (fig. 5) . Papillary form. There is a papillary or a domelike protrusion into the colon canal. The labia are lumped together and cannot be positively recognized as in the case of the labial form. Sometimes the protrusion is so extreme that it resembles a semipedunculated polyp (fig. 6). Intermediate form. Every possible form between the papillary and labial form is included. The protrusion is not as promi-
407
FIG. 5. Labial sphincter. The upper half represents the sphincter. The small dark part in the middle of the figure is the mouth of the sphincter. The frenulum is seen at the right lower part.
nent as in the papillary form, and the summit is usually flat. Its lateral figure appears somewhat trapezoid (fig. 7) . Movement of the Ileoc ecal Sphin cter
DiDio and Anderson 6 stated that the ileocecal sphincter was classified into two forms : labial and papillary . The labial form was common in vitro arid the papil lary form was prevalent in vivo . However, the fibercolonoscopic observation revealed that the shape of the ileocecal sphincter was by no means constant. In the living subject, the ileocecal sphincter of the same individual changed and showed both the labial and papillary forms taking an intermediate form en route. Usually the ileocecal sphincter showed labial or intermediate form when the terminal ileum was in a hypokinetic state . As the ileal movement reached the terminal segment, the ileocecal sphincter protruded and the labia of the sphincter lumped together showing the papillary form. The ileal contents flowed into the colon when the sphincter was papillary in form. The flow was usually slow and rather intermittent. The ileal contents did not appear to flow rapidly or heavily into the colon. There were cases of papillary sphincter
408
NA GASAKO AND T A KEMOTO
Vol. 65, N o.3
FIG. 7. Intermediate s phincter , th e upper bright half represents the latera l aspect of th e sphincter.
sphincter remained papillary for more than 5 min. During that period the ileal contents flowed intermittently into the colon. The ileocecal sphincter seemed to regulate the flow of the ileal contents into the large intestine by changing its form. The form of the ileocecal sphincter in the same individual is shown in figures 5, 6, and 7. Root of the appendix. The worm-like structure, called the vermiform appendix, was originally the cecal apex . Because of the eccentric growth of the cecum , the base of the appendix arises from the posteriomedial aspect of the fully developed cecum, about 2.5 em below the ileocecal junction . The base of the appendix is almost always FIG. 6. A , Papillary sphincter: the round body retrocecal. 7 In looking for the root of the seen in the upper middl e of the picture is th e appendix, it is more helpful to find the ileosphincter. B, Liquid ilea l contents are seen flowing cecal sphincter first, and then the posterior out of the pa pillary sphinct er. wall of the cecum. The movement of the appendix is conwithout any flow of ileal contents. The lack trolled by the autonomic nervous system. of flow might be due to scanty ileal con- Thus, the root of the appendix takes tents. The papillary protrusion again be- various forms just as the ileocecal sphinccame flat, and the labial structure reap- ter does. The endoscopic appearance of the peared. No contents appeared to flow out root of the appendix, as observed from the of the labial sphincter. The form of the colon canal , was grossly divided into two sphincter was largely due to the movement forms: flat and protruded. In the former of the terminal ileum, but the ileocecal the root of the appendix was flat, and its mouth was open or closed. In the latter, the sphincter seemed to possess the mechanism to maintain its form since it continued root protruded into the cecum and the to be papillary far longer than each rhythm . mouth was closed. In some cases of the of ileal movement. Sometimes the ileocecal protruded root, there was a frenular struc-
S ept ember 1973
ENDOS COPY OF THE ILEOCECAL AREA
ture. It was sometimes difficult to differentiate such a root from the ileocecal sphincter. The root was usually flat when the appendix relaxed, and became protruded when the appendix contracted. Introduction of the biopsy forceps into the appendix to obtain specimens for histological examination was not difficult. The wall of the appendix is thickened by extensive development of lymphatic tissue which forms an almost continuous layer, with many large and small lymphatic nodules. Since the lumen of the appendix often contains masses of dead cells and detritus~ it is difficult to differentiate between normal arid certain pathological conditions. 8 Terminal ileum. The distal segment of the ileum is called the terminal ileum. Its lumen is smaller than that of the colon . In the terminal ileum, the plicae circulares disappear almost entirely. 8 Thus, the distinction between the terminal ileum and the ascending colon is evident endoscopically. In the ascending colon the semilunar folds can clearly be observed. The mucosal surface of the terminal ileum was flat when there was no lymph follicular hyperplasia. Sometimes a villous pattern could clearly be observed. 1 The most characteristic feature of the terminal ileum was the abundance of lymphatic tissue. Hyperplastic lymph follicles could easily be observed by fibercolonoscope. They protruded on the mucosal surface giving a granular appearance. Each follicle varied in size. They ranged from less than 1 mm to 10 mm or more in diameter. A large lymph follicle which resembles a semipedunculated polyp is shown in figure 8. Biopsy specimens revealed such follicles to be of lymphatic origin.'· 9 "Worm-like" soft protuberances were observed at the terminal ileum. They were also proved to be of lymphatic origin; therefore, they were assumed to be Peyer's patches (fig. 9).
However, it was rather rare, by fibercolonoscope, to clearly identify Peyer's patches. Biopsy specimen from each follicle showed lymph follicular origin. The terminal ileum could be divided into four
409
FIG. 8. A large lymph follicl e.
FIG. 9. Peyer's patch .
groups (grades 0 to III) endoscopically for the convenience of description, according to its mucosal appearance. 9 Our definition is as follows: grade 0-either an absence of lymph follicles or, if at all, a: few minute follicles distributed sporadically; grade !-diffusely but sparsely distributed follicles are usually seen, and each follicle is tiny ; grade 11-diffusely and rather densely distributed lymph follicles are seen, conglomerations between follicles are not usually seen , and the individual follicles are smaller than
410
Vol. 65 , No.3
NAGASAKO AND TAKEMOTO
those of grade III; grade III -lymph follicles are diffuse and densely distributed, the individual follicles are generally large, and interfollicular conglomerations or fusions are evident, thereby presenting various and diverse endoscopic features; the covering epithelium sometimes shows hyperemia (fig. 10) . Fifty patients were observed. (Twelve cases of inflammatory diseases with ileocecal involvement and 4 cases of unclean terminal ileum were excluded.) The relationship between the age of patients and the "grade" is shown in figure 11. The following can be derived from the figure. (a) A greater number of patients displayed the grade 0 endoscopic features of the terminal ileum (56%). (b) Lymph follicles of any grade could be observed in the 20-, 30-, and 40-year age groups. However, in the 20-year age group, the grade II lymph follicles prevailed and in the 30- and 40year age ·groups, the grade 0 lymph follicles prevailed. (c) In the age group under 19 years, no cases of the groups 0 and I lymph follicles were found. (d) The extent of the lymph follicular hyperplasia varied grossly in inverse proportion to age. It is safe to say that the grade III lymph follicular hyperplasia is merely a physiological phenomenon in the younger age groups . Conclusions One hundred patients in whom the fibercolonoscope was inserted into the ileocecal area were considered in this study . The most important point of the colonoscope insertion technique is to advance the scope orally while observing the proximal colon, and to use minimal air insufflation, as is the case in rigid sigmoidoscopy. In fibercolonoscopy, unlike rigid sigmoidoscopy, we encountered loop formation. That can be resolved by pull-the-scope techniques, which correspond to pulling the scope at the blind end by sigmoidoscopy. The effect of the inserted scope on the observation of the ileocecal area was studied. One loop at the sigmoid or the transverse colon did not significantly interfere with observation of this area. Therefore, such a loop could be left unresolved. But
FIG. 10. Lymph follicular hyperpl asia of grade III.
Ill
=·· ... :::····· grade
age
10
20
30
40
50
60
70
FIG. 11. Lymph follicles and age.
in cases where two loops remained, observation at the ileocecal area was greatly hindered. The normal endoscopic appearance of the ileocecal area was studied. Both the ileocecal sphincter and the root of the appendix manifested various forms, according to the intestinal motility. The ileocecal sphincter showed labial, papillary, or intermediate form, according to the ileal movement. The form of the ileocecal sphincter was largely dependent on the movement of the terminal ileum. On the other hand, the ileocecal sphincter seemed to have some mechanism to control the flow of the ileal contents into the colon by changing its form. As the ileal movement reached the terminal ileal segment, the ileocecal sphincter protruded showing the papillary form. The ileal contents flowed into the colon when the sphincter was papillary in form. The root of the appendix showed a flat or a protruded form, according to the
September 1973
ENDOSCOPY OF THE ILEOCECAL AREA
appendiceal movement. The terminal ileum could be classified into four groups (grade 0 to III) according to the mucosal appearance derived from the lymph follicular hyperplasia. The extent of the lymph follicular hyperplasia varied greatly in inverse proportion to age. Lymph follicular hyperplasia, which is common in young people, is merely a physiological phenomenon. The ileocecal area was a difficult segment for the endoscopists to examine. However, recent progress in the field of fiberoptics has made endoscopic observation of that area possible. We think that this will contribute immensely to the physiological studies of this segment of the intestinal tract. REFERENCES 1. Nagasako K, Yazawa C, Takemoto T: Observation of the terminal ileum. Endoscopy 3:45-51, 1971
411
2. Tajima T , Toda S: Technique of use of colonofiberscope. Stomach Intestine (Tokyo) 5:1429-1435, 1970 3. Watanabe H , Narasaka T, Uezu J: Colonofiberscopy. Stomach Intestine (Tokyo) 6:1333-1336, 1971 4. Alvarez WC: An Introduction to Gastroenterology. Fourth edition. New York, Paul B. Roeber 5. Nagasako K, Takemoto T: Fibercolonoscopy with· out the help of fluoroscopy. Endoscopy 4:208- 212, 1972 6. DiDio LJA, Anderson MC: The "Sphincters" of the Digesti~e System. Baltimore, Williams & Wilkins Co, 1968 7. Bockus HL: Gastroenterology, vol 2,. Second edition. Philadelphia and London, WB Saunders Co, 1966 8. Bloom W, Fawcett DW: A Textbook of Histology. Eighth edition. Philadelphia and London, WB Saunders Co, 1962 9. Nagasako K, Yazawa C, Takemoto T: Biopsy of the terminal ileum, Gastroenterology 60:823, 1971. Gastrointest Enclose 19:7-10, 1972