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Rare case of the inferior mesenteric artery arising from the superior mesenteric artery.

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THE ANATOMICAL RECORD 217:99-102 (1987)
Rare Case of the Inferior Mesenteric Artery Arising
from the Superior Mesenteric Artery
SEIICHIRO KITAMURA, TAKAHIKO NISHIGUCHI, AKIRA SAKAI, AND
KENZO KUMAMOTO
The Second Department of Oral Anatomy, Osaka University Faculty of Dentistry, Osaka,
565 (S.K., TN., A.S.) and The Department ofdnatomy, Meiji College of Oriental Medicine,
Kyoto 62903 (K.K.), Japan
ABSTRACT The authors observed a variation of the inferior mesenteric artery,
which arose from the superior mesenteric artery, in a 69-year-old Japanese male
cadaver during dissection in 1984. In this case, no rudiment of the ordinary inferior
mesenteric artery could be found on the abdominal aorta. There are few reports of
this variation, and an extensive search of the available literature revealed only four
cases, including two in Japan. Such a variation had been somewhat inadequately
described as an “absence of the inferior mesenteric artery” in the previous reports,
but we avoided this terminology, because all of the cases possessed an artery, which,
though arising from the superior mesenteric artery instead of the abdominal aorta,
had the same branches as a normal inferior mesenteric artery. Consistent with
findings observed in the previous cases, the unusual inferior mesenteric artery arose
as the first branch of the superior mesenteric artery, with the common trunk of both
mesenteric arteries originating from the abdominal aorta at a level at which an
ordinary superior mesenteric artery would arise. It is for this reason that we did not
adopt another acceptable name, that is, “the common mesenteric artery,” for this
variation. The variation can be explained as the result of an unusual development
of the embryonic artery system, which comprises a number of ventral splanchnic
arteries interconnected by longitudinal anastomotic channels to supply the primitive digestive tube.
The inferior mesenteric artery is generally a direct
unpaired visceral branch of the abdominal aorta, which
diverges at the level of the third lumbar vertebra, considerably below the origin of the superior mesenteric
artery. However, a very rare displacement of the inferior
mesenteric artery, in which it arose from the superior
mesenteric artery, was reported before. Such a variation
was previously described, though somewhat inadequately, as an “absence of the inferior mesenteric
artery.”
The case presented here was observed in a 69-year-old
Japanese male cadaver during dissection in 1984. Despite a detailed search, no rudiment of the ordinary
inferior mesenteric artery, which normally would arise
from the abdominal aorta, could be demonstrated.
CASE REPORT (Fig. 1 )
The superior mesenteric artery, having a diameter of
about 10 mm, arose singly from the front of the abdominal aorta at the level of the upper margin of the first
lumbar vertebra. It descended about 43 mm and then
gave off, to our great surprise, the inferior mesenteric
artery, with a diameter of about 4.0 mm, to the left and
downward, after which it narrowed to a diameter of
about 8.0 mm and continued its normal downward
course.
At about 5 mm from its point of origin, the unusual
inferior mesenteric artery gave off the left colic artery
0 1987 ALAN R. LISS, INC.
with a diameter of about 2.0 mm. After passing to the
left about 48 mm, the left colic artery divided into two
branches, each with a diameter of about 2.0 mm: one
passing downward t o supply the descending colon and
the other continuing laterally. The former ran about 121
mm, while sending its twigs to the descending colon,
and finally anastomosed with a branch from the first
sigmoid colic artery, which will be described later. The
latter passed to the distal half of the transverse colon,
with repeated divergences. Unfortunately, we could not
examine its anastomosis with the middle colic artery,
which was a direct branch of the superior mesenteric
artery, because the vessels of this region had already
been removed by students at the time of discovery of the
variation. The inferior mesenteric artery, after giving
off the left colic artery, ran about 91 mm to the left and
downward and then divided into the first sigmoid artery
passing to the left, laterally and downward, and the
superior rectal artery, continuing downward, with diameters of about 4.0 and 3.0 mm, respectively.
Three arteries were found to supply the sigmoid colon
in this case; we named them the first t o third sigmoid
Received April 30, 1986; accepted August 1, 1986.
Address reprint requests to Seiichiro Kitamura, The Second Department of Oral Anatomy, Osaka University Faculty of Dentistry. 1-8,
Yamadaoka, Suita, Osaka, 565, Japan.
100
S. KITAMURA, T. NISHIGUCHI, A. SAKAI, AND K. KUMAMOTO
colic arteries, respectively, as a matter of convenience.
The first sigmoid colic artery, after diverging from the
inferior mesenteric artery, ran about 13 mm to give off
the second sigmoid colic artery with a diameter of about
2.0 mm, which descended in parallel with the superior
rectal artery and finally anastomosed with the third
sigmoid colic artery arising from the superior rectal
artery a t the sigmoid colon region. Subsequently, the
first sigmoid colic artery, narrowing to about 2.0 mm in
diameter, ran further to the left and then divided into
Abbreviations
abdominal aorta
left colic artery
coeliac trunk
dorsal aorta
left gastric artery
hepatic artery
lienal artery
longitudinal anastomotic channels among the ventral
segmental arteries
LSA,
lateral splanchnic arteries
MI and MS, inferior and superior mesenteric arteries
PD,
primitive digestive tube
RS,
superior rectal artery
SA,
somatic arteries
SI, SII, and first, second, and third sigmoid colic arteries
SIII,
VSA,
ventral splanchnic arteries
A,
CL,
CT,
DA,
G,
H,
L,
LA,
two branches: one turning upward to reach the descending colon and finally anastomosing with the left colic
artery, as described before, and the other descending
further to reach the sigmoid colon region.
The superior rectal artery, after diverging from the
inferior mesenteric artery, further descended to cross in
front of the left common iliac artery and enter the pelvic
cavity, immediately before which it branched to give off
the third sigmoid colic artery with a diameter of about
2.0 mm. The third sigmoid colic artery divided into a
branch passing to the upper portion of the rectum and
another supplying the lower portion of the sigmoid colon, the latter of which anastomosed with the second
sigmoid colic artery described above.
DISCUSSION
The term “absence of the inferior mesenteric artery,”
adopted for this kind of variation in previous reports,
would appear to be somewhat inadequate, because all
reported cases possessed a n artery that, though arising
from the superior mesenteric artery instead of the abdominal aorta, had the same branches as the ordinary
inferior mesenteric artery. We, therefore, consider such
a variation as “the inferior mesenteric artery arising
form the superior mesenteric artery.” But, it may also
be considered as a variation characterized by a “common mesenteric trunk,” since the superior and inferior
Fig. 1. Photograph showing the branching of the superior mesenteric artery in the case of the subject.
An unusual branch (arrow) diverges from the superior mesenteric artery and supplies the inferior
mesenteric artery region of usual cases. The ordinary inferior mesenteric artery, originating from the
abdominal aorta, is not found anywhere.
101
VARIATION OF THE INFERIOR MESENTERIC ARTERY
mesenteric arteries arise as a common trunk from the
abdominal aorta.
There are few reports on the absence of the inferior
mesenteric artery. An extensive search of the available
literature through the 19th and 20th centuries has revealed only four reported cases of this variation, including two cases in Japan (Fleishman, 1815-children, age,
and sex distinction being unknown, cited from Adachi’s
report; Gwyn and Skilton, 1959-79-year-old male; in
Japan: Adachi, 1930-45-year-old male; Mori et al.,
1960-60-year-old male). In the five cases of the variation including the present one, the common trunk of the
superior and inferior mesenteric arteries always arose
from the abdominal aorta at a level at which an ordinary superior mesenteric artery would arise. It is for
this reason that we did not adopt the name “common
mesenteric trunk” for this variation. The inferior mesenteric artery always diverged as the first branch of the
superior mesenteric artery within a distance of 1.0 to
4.5 cm from the origin of the latter artery.
The artery system for the abdominal alimentary organs is originally segmental in development: it derives
from a number of pairs of ventral splanchnic arteries,
with segmental character, diverging from the paired
dorsal aortae (Williams and Worwick, 1980). The paired
ventral splanchnic arteries are distributed to the wall of
the yolk sac at an early stage of development, but after
fusion of the dorsal aortae they also fuse into unpaired
trunks and come to supply the primitive digestive tube
(Fig. 2). These trunks are at first connected with each
other by longitudinal anastomotic channels, which form
dorsal and ventral splanchnic anastomoses along the
dorsal and ventral aspects of the tube. In the later stages
of development, however, the artery complex along the
digestive tube is simplified with the disappearance of a
e
great number of the vessels, and finally it is transformed
into three systems of arteries that supply the foregut,
midgut, and hindgut, respectiveIy; the coeliac trunk and
the superior and inferior mesenteric arteries.
From the above-mentionedontogenesis of the arteries,
Tandler (1903, 1904) and Morita (1935) embryonically
explained the variations related to the coeliac trunk and
superior mesenteric arteries, as follows: The coeliac
trunk and the superior mesenteric artery grow out of a
net of arteries comprising the proximal four of the ventral splanchnic arteries connected by the longitudinal
anastomotic channel (Fig. 3a). In an ordinary process of
d
C
b
a
Fig. 2. Diagram showing the abdominal segmental somatic and
splanchnic arteries of a human embryo about 4 weeks old.
f
9
Fig. 3. Diagrams a-d show the patterns of development of the normal coeliac trunk and superior
mesenteric artery (b) or their variations (c and d) from the primitive system of the ventral splanchnic
arteries (a). This explanation is based on the opinions of Tandler (1903, 1904) and Morita (1935). Those of
e-g show the patterns of development of the variation of subject (0 and the intermesenteric arterial
communications (g) from the primitive arterial system (e), which are inferred from the patterns of
development, a-d.
102
S. KITAMURA, T. NISHIGUCHI, A. SAKAI, AND K. KUMAMOTO
development of the arterious net, the middle two of the
four splanchnic arteries, together with the longitudinal
channel, disappear as shown in Figure 3b to normally
form the coeliac trunk and the superior mesenteric artery. On the other hand, such variations as the “truncus
coeliacomesentericus” and the “truncus hepatomesentericus” occur owing to unusual patterns of development
of the net, which are shown in Figure 3c and d, respectively. There are no reports that embryologically explain the inferior mesenteric artery arising from the
superior mesenteric artery. However, we consider it possible to explain this variation by applying the pattern of
development of the truncus coeliacomesentericus between the superior and inferior mesenteric arteries. The
application seems reasonable, because the ventral
splanchnic arteries connected by the longitudinal anastomotic channels continue as far caudally as the hindgut
region (Fig. 3e). That is to say, the variation is thought
to result from the ontogenetic pattern (Fig. 30 in which
the longitudinal channel betewen both mesenteric arteries remains intact and the ventral splanchnic artery
originally growing into the ordinary inferior mesenteric
artery loses its proximal portion. A similar pattern of
development may also explain the other kind of variation between the superior and inferior mesenteric arteries (Williams and Klop, 1957), in which an unusual
anastomotic branch, named the intermesenteric arterial
communication, was found between both mesenteric arteries (Fig. 3g).
LITERATURE CITED
Adachi, B. (1930) Das Fehlen der A. mesenterica inferior bei einem
Japaner. Anat. Am., 69:431-433.
Gwyn, D.G., and J.S. Skilton (1959) A rare variation of the inferior
mesenteric artery in man. Anat. Rec., 156:235-238.
Mori, Y., I. Ito, S. Hatashita, and K. Yoshikawa (1960) An anomalous
case of the mesenteric arteries, absence of A. mesenterica superior.
J. Osaka Med,,Coll., 2Ot77-79 (in Japanese).
Morita, S. (1935) Uber 3 Falle von seltenen Variationen der A. coeliaca
und A. mesenterica superior. Igaku Kenkyu, 9:1993-2006 (in
Japanese).
Tandler, J. (1903) Zur Entwickelungsgeschichte der menschlichen Darmarterien. Anat. Hefte., 23:187-210.
Tandler, J. (1904) Uber die Varietaten der Arteria coeliaca und deren
Entwickelung. Anat. Hefte., 25473-500.
Williams, G.H., and E.J. Klop (1957) Intermesenteric arterial communications. Univ. Mich. Med. Bull., 23:53-57.
Williams, P.L., and R. Worwick (1980) Gray’s Anatomy, 36th ed.
Churchill Livingstone, Edinburgh, pp. 149-168.
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