Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_1441_Библиотеки_им_академика_М_И_Перельмана.pdf
116 Radiographic appearance of the mesenteryandperitoneum
REFERENCE ATLAS
Using the soware and archive described earlier, we
recently developed a reference atlas for the CT appearance
of the mesentery, as well as associated fascia and perito-
neal reections. e atlas refers to the mesentery from the
duodenojejunal level to the junction between the rectum
and anus. Each panel includes (1) a full color image (high-
lighting either exural or nonexural mesentery, underly-
ing fascia, and associated peritoneal reection) and (2) the
corresponding CT image. is enables the viewer to iden-
tify, within the CT, the shapes corresponding to mesentery,
fascia, and peritoneum [7].
To test the utility of this atlas, we determined rates at
which exural and nonexural mesentery could be identi-
fi d in normality. Radiologists rst examined the atlas and
then serially reviewed abdominal CT scans, which were
known to lack intra-abdominal pathology. Regions corre-
sponding to exural and nonexural mesentery were con-
sistently identiable in all patients (Figure 8.7a throughd).
Hepatic flexure
Hepatic flexure
Splenic flexure(d)
(c)
(b)
(a)
Splenic flexure
Flexures
Figure 8.7 Images taken from the reference atlas of mesenteric radiology. (a) Right mesocolon (coronal view). This is
a nonexural region of the mesocolon (i.e., the mesocolon is attached to the retroperitoneum). (b) The hepatic exure
(axial view). The right mesocolon, hepatic exure, and transverse mesocolon are seen. Continuity is apparent between all
three. (c) Splenic exure (coronal view). The transverse and left mesocolon are evident as is the exural region interposed
between both (i.e., the splenic exure). (d) Left mesocolon on axial view.
References 117
e rate of identication of exural and nonexural regions
of the mesentery increased as one proceeded distally from
the ileocecal to the mesosigmoidal and mesorectum
level[7].
Ideally, all mesenteric (exural and nonexural) regions
should be identiable in all patients. is did not hold in the
study in question and while there was good general agree-
ment between radiologists, there was discordance in a con-
siderable proportion of cases. Future studies should aim to
improve the rates of identication of exural and nonexural
regions based on current anatomic appraisals. is should
initially be conducted in states of normality (prior to pro-
ceeding to disease states) and could employ the reference as a
guide to identication of exural and nonexural regions [7].
IMPLICATIONS FOR THE RADIOLOGIC
APPRAISAL OF ABDOMINAL DISEASE
ere are several implications for the developments
described above. In the rst instance, the reference atlas
generated provides a standard that should aid radiologists
in identifying separate mesenteric regions from the SMA
origin to the anorectal junction. It remains to be validated
in this context. By better identifying normality, one can
improve the radiologic appraisal of abnormality. In keeping
with this, the eff cts of benign and neoplastic processes may
be better staged by taking into account the manner in which
they aff ct the mesentery, underlying fascia, and adjacent
peritoneal reections.
FUTURE STUDIES: ASSEMBLING
A COMPREHENSIVE MODEL
OFABDOMINAL ANATOMY
The ability to reliably identify mesenteric, fascial, and
peritoneal structures on standard abdominal CT enables
one assemble a highly accurate and comprehensive
model of intra-abdominal anatomy in the undisturbed
state. For example, the mesentery (once correctly delin-
eated) could serve as a starting point around which ret-
roperitoneal, omental, intestinal, fascial, and peritoneal
structures can be assembled. It would then be a simple
matter to digitally add or subtract components to the
resultant model.
Th s process could then be repeated in disease settings.
If pathology were present, then it would be feasible for the
radiologist to generate a 3D reconstruction of the intestine,
associated mesentery, retroperitoneum, and greater omen-
tum (and other structures). He or she could then sequen-
tially subtract individual structures to better demonstrate
the 3D features of the pathology in question. In the fi st
instance, this would be an invaluable educational tool. In
addition, however, it would also represent a clinical utility
as it would facilitate planning of interventional radiologic
procedures such as the drainage of an abscess or obtaining
tissue for biopsy.
SUMMARY
e radiologic appearance of the mesenteric organ distal
to the duodenojejunal exure requires reappraisal in view
of recent clarications in structure. In completing one
such appraisal on the CT appearance, a radiologic atlas
was developed for reference in normality. is provides a
reference against which the radiologic appearance of intra-
abdominal disease can be compared. Future studies should
aim to interpret the appearance of intra-abdominal disease
based on comparisons with this standard.
REFERENCES
1. Li, Y. and K. Hauenstein, New imaging techniques
in the diagnosis of inammatory bowel diseases.
Viszeralmedizin, 2015. 31(4): 227–234.
2. Treves, F., Lectures on the anatomy of the intesti-
nal canal and peritoneum in man. Br Med J, 1885.
1(1264): 580–583.
3. Coffey, J.C., Surgical anatomy and anatomic
surgery—Clinical and scientic mutualism. Surgeon,
2013. 11(4): 17 7–182 .
4. Culligan, K. etal., The mesocolon: A prospective
observational study. Colorectal Dis, 2012. 14(4):
421–428; discussion 428–430.
5. Culligan, K. etal., The mesocolon: A histological
and electron microscopic characterization of the
mesenteric attachment of the colon prior to and
after surgical mobilization. Ann Surg, 2014. 260(6):
1048–1056.
6. Sehgal, R. and J.C. Coffey, Historical develop-
ment of mesenteric anatomy provides a universally
applicable anatomic paradigm for complete/total
mesocolic excision. Gastroenterol Rep, 2014. 2(4):
245–250.
7. Coffey, J.C. etal., An appraisal of the computed
axial tomographic appearance of the human
mesentery based on mesenteric contiguity from
the duodenojejunal exure to the mesorectal level.
EurRadiol, 2016. 26(3): 714 –721.
8. Coffey, J.C. and P. Dockery, Colorectal cancer:
Surgery for colorectal cancer—Standardization
required. Nat Rev Gastroenterol Hepatol, 2016.
13(5): 256–257.
9. Coffey, J.C. et al., The mesentery in Crohn’s disease:
Friend or foe? Curr Opin Gastroenterol, 2016. 32(4):
267–273.
10. Oliphant, M. and A.S. Berne, Computed tomography
of the subperitoneal space: Demonstration of direct
spread of intraabdominal disease. J Comput Assist
Tomo g r, 1982. 6(6): 112 7–113 7.
11. Oliphant, M. and A.S. Berne, Mechanism of direct
spread of abdominal neuroblastoma: CT demonstra-
tion and clinical implications. Gastrointest Radiol,
19 8 7. 12(1): 59– 66.
118 Radiographic appearance of the mesenteryandperitoneum
12. Oliphant, M., A.S. Berne, and M.A. Meyers,
The subserous thoracoabdominal continuum:
Embryologic basis and diagnostic imaging of disease
spread. Abdom Imaging, 1999. 24(3): 211–219.
13. Oliphant, M., A.S. Berne, and M.A. Meyers, The
subperitoneal space of the abdomen and pelvis:
Planes of continuity. Am J Roentgenol, 1996. 167(6):
1433–1439.
14. Oliphant, M., A.S. Berne, and M.A. Meyers, Direct
spread of subperitoneal disease into solid organs:
Radiologic diagnosis. Abdom Imaging, 1995. 20(2):
141–147; dis cuss ion 148.
15. Oliphant, M., A.S. Berne, and M.A. Meyers,
Bidirectional spread of disease via the subperitoneal
space: The lower abdomen and left pelvis. Abdom
Imaging, 1993. 18(2): 117–125.
16. Oliphant, M., A.S. Berne, and M.A. Meyers, Spread
of disease via the subperitoneal space: The small
bowel mesentery. Abdom Imaging, 1993. 18(2):
10 9 –116 .
17. Oliphant, M., A.S. Berne, and M.A. Meyers, Imaging
the direct bidirectional spread of disease between
the abdomen and the female pelvis via the sub-
peritoneal space. Gastrointest Radiol, 1988. 13(4):
285–298.
18. Dodds, W.J. etal., The retroperitoneal spaces revis-
ited. Am J Roentgenol, 1986. 147(6): 1155 –1161.
19. Toldt, C., Bau und wachstumsveranterungen
der gekrose des menschlischen darmkanales.
Denkschrdmathnaturwissensch, 1879. 41: 1–56.
20. Charnsangavej, C. etal., CT of the mesocolon. Part
1. Anatomic considerations. Radiographics, 1993.
13(5): 1035 –1045.
21. Charnsangavej, C. etal., CT of the mesocolon. Part
2. Pathologic considerations. Radiographics, 1993.
13(6): 13 09–132 2.
22. Healy, J.C. and R.H. Reznek, The peritoneum, mes-
enteries and omenta: Normal anatomy and patho-
logical processes. Eur Radiol, 1998. 8(6): 886–900.
23. Johnson, P.T., K.M. Horton, and E.K. Fishman,
Nonvascular mesenteric disease: Utility of multide-
tector CT with 3D volume rendering. Radiographics,
2009. 29(3): 721–740.
24. Ramachandran, I. etal., Multidetector computed
tomography of the mesocolon: Review of anatomy and
pathology. Curr Probl Diagn Radiol, 2009. 38(2): 84–90.
25. Coffey, J.C. etal., Terminology and nomenclature in
colonic surgery: Universal application of a rule-based
approach derived from updates on mesenteric
anatomy. Tech Coloproctol, 2014. 18(9): 789–794.
26. Sehgal, R. and J.C. Coffey, The development of
consensus for complete mesocolic excision (CME)
should commence with standardisation of anatomy
and related terminology. Int J Colorectal Dis, 2014.
29(6): 763–76 4.
27. Coffey, J.C. and P. Dockery, Colorectal cancer:
Surgery for colorectal cancer—Standardization
required. Nat Rev Gastroenterol Hepatol, 2016.
13(5): 256–257.
28. Rosset, A. et al., OsiriX: An open-source software for
navigating in multidimensional DICOM images. J Digit
Imaging, 2004. 17(3): 205–216.
29. Spitzer, V. etal., The visible human male: A technical
report. J Am Med Inform Assoc, 1996. 3(2): 118–130.
30. Ackerman, M.J., The visible human project.
JBiocommun, 1991. 18 (2): 14.
31. Juanes J.A. et al., Application of the “Visible Human
Project” in the eld of anatomy: A review. Eur J
Anat, 2003. 7: 147–159.
32. The National Library Of Medicine’s Visible Human
Project. https://www.nlm.nih.gov/research/visible/
visible_human.html, 2016. Web. April 6, 2016.
33. Shamshuddin, S. and H.R. Matthews, Use of OsiriX
indeveloping a digital radiology teaching library.
Clin Radiol, 2014. 69(10): e373–e380.
34. Peirce, C. etal., Digital sculpting in surgery: A novel
approach to depicting mesosigmoid mobilization.
Tech Coloproctol, 2014. 18(7): 653–660.
119
9
Operative nomenclature
J. CALVIN COFFEY, BILL HEALD, AND BRENDAN J. MORAN
If the English language made any sense, lacka-
daisical would have something to do with
A shortage of owers
Doug Larson
AIM
e rst aim is to discuss the general importance of
nomenclature in surgery. e second aim is to summa-
rize the anatomic nomenclature that stems from recent
advancements in our understanding of mesenteric and
peritoneal anatomy. e third aim is to demonstrate how
this is applicable to colorectal surgical procedures and
operations.
INTRODUCTION
Nomenclature is the code used to aid description. An
eff ctive nomenclature comprises elements that are ratio-
nal and, when combined, have a meaning that is greater
than each element in isolation. In chemistry, the elements
are combined to represent molecules and the combina-
tion of these represents chemical interactions. In math-
ematics, symbols are used to represent concepts and their
combination in equation format becomes a function.
Although gastrointestinal surgery is a science, the associ-
ated nomenclature is imprecise. If we are to utilize con-
ventional surgical nomenclature, then an example would
be as follows:
Total mesorectal excision involves mobilization
ofthe mesorectal package conned by the meso-
rectal fascia, by its separation via diathermy, from
extra mesorectal fascial structures.
A further example is
Complete mesocolic excision involves separa-
tion of the parietal and visceral fascia.
Given the confu sion and misconceptions that have sur rounded
mesenteric anatomy, it is not surprising that a broad lexicon
of terminology has been developed by diffe ent clinical and
scientic disciplines [1–6]. While it is correct to say that sur-
geons have long recognized the importance of the mesenteric
package, it was not until the development of total mesorectal
excision, the emergence of laparoscopic and robotic colorec-
tal surgery, and the recent demonstration of mesenteric con-
tinuity that the mesenteric basis of intestinal surgery gained
prominence [7–10]. Not surprisingly, there has been a lag time
in synchronizing surgical operative and technical nomencla-
ture with these developments [1–4]. Terms “total mesorectal
excision,” “complete mesocolic excision,” and “total meso-
colic excision” are relatively new and are increasingly being
adopted into the technical lexicon [1–4,11–26]. ey have yet
to fully substitute terms such as “anterior resection,” “procto-
sigmoidectomy,” and “ileocolic resection.”
e radiological nomenclature utilized in addressing
the mesentery is also hampered by little overall consensus.
Oentimes, the terms Gerota’s fas cia, the “anterior renal fascia,”
and the “anterior pararenal space” are used interchangeably.
Aim 119
Introduction 119
Anatomic terminology 120
In general 120
Pedicles 120
Mesentery 121
Peritoneal reection 125
Fascia 128
Congenital adhesions 128
Surgical adaptation of anatomic terminology 131
Resectional nomenclature in colorectal surgery 131
Technical nomenclature 131
Partial or total right mesocolectomy 133
Application of terminology to radiological
nomenclature 134
Future directions 135
Summary 135
References 135
120 Operative nomenclature
Although mesenteric and mesocolic are increasingly used in
radiologic appraisals of intra-abdominal disease, the terms
Toldt’s fascia and peritoneal reections are infrequently used,
and no distinction is made between exural and nonex-
ural components or attached and mobile components of the
mesocolon [27–30]. Th s stems largely from the diculties
associated with this fi ld. While it may be possible to readily
identify the right and left mesocolon, as well as the mesorec-
tum, separate regions of the mesosigmoid are more dicult
to categorize. In addition, extension of the mesentery at the
intestinal margin means that there is considerable folding and
overlap at this level. ese properties are extremely challeng-
ing for radiologic interpretation and hence for the develop-
ment of appropriate terminology [1,3,4,30–32].
In the absence of consensus, and in the context of recent
observations, a rule-based nomenclature should be generated
that can universally be applied across scientific and clinical
disciplines [1–4,33,34]. Any such nomenclature should be
transferrable from anatomic to surgical and radiological con-
texts. It should be simplistic and clear and thus readily adapt-
able in an intuitive manner. In this chapter, we fi st describe an
intuitive and anatomic-based nomenclature to the mesentery,
peritoneal refl ction, and Toldt’s fascia. We then apply this
nomenclature to surgical and radiological contexts.
ANATOMIC TERMINOLOGY
Although the anatomic terminology has been dealt with in
detail in Chapter 2, a list of terms and associated descrip-
tions will be outlined here.
Root of mesentery: e root of the mesentery occurs
where the superior mesenteric artery emerges from under-
neath the pancreas. From this point, the entire mesentery
distal to the duodenojejunal exure fans out. Overall, it is
packaged in a spiral conformation and compactly plicated
at the intestinal margin (Figure 9.1).
IN GENERAL
Attachment: Where the mesentery becomes apposed with the
retroperitoneum. It does not refer to insertion of the mesen-
tery into the posterior abdominal wall. e mesentery does
not insert into the posterior abdominal wall at any point.
Suspension: Where the mesentery is suspended from the
posterior abdominal wall at points of vascular continuity.
Duodenojejunal exure: e region of small bowel and
associated mesentery where the duodenum changes from
attached to the nonattached (Figure 9.2).
Intestinal mesentery: Structure interposed between the
intestinal tract and the posterior abdominal wall and con-
tiguous with both (Figure9.3).
Flexural mesentery: Mesenteric component of a exure
(Figure 9.4).
Nonexural mesentery: Mesentery between two exures.
An example is the small bowel mesentery (between the duo-
denojejunal and ileocecal exure). Examples include the right
and left esocolon, the mesosigmoid, and mesorectum.
PEDICLES
Adipovascular pedicle: Mesentery surrounding a major ves-
sel. Examples include the superior mesenteric artery (and
its ileocolic extension) and the right, middle, and left colic
arteries. Also included are the inferior mesenteric artery and
its continuation as the superior rectal artery (Figure 9.5).
Posterior
abdominal wall
Mesenteric root
Mesenteric root region
Duodenum
Figure 9.1 View of the anatomic root of the mesentery
in a cadaver. The mesentery fans out from where the
superior mesenteric artery emerges from underneath the
pancreas. This occurs to the right of the fourth part of the
duodenum as indicated.
Duodenum
Duodenojejunal flexure
Duodenojejunal flexure
Jejunum
Figure 9.2 The duodenojejunal exure in a cadaver,
wherethe duodenum changes direction to detach
from the posterior abdominal wall and continues as the
jejunum.
Mesentery 121
Interpedicular (avascular) mesentery: Mesentery between
successive vascular pedicles (Figure 9.6).
MESENTERY
Small bowel mesentery: Mesenteric region associated with
the small intestine.
Intestinal mesenteric margin: Edge of the mesentery
attached to the intestine. Note that a corresponding nonin-
testinal margin is lacking as the mesentery fans out from the
superior mesenteric root region (Figure 9.7).
Ileocecal mesenteric region: Region of mesentery asso-
ciated with terminal ileum and cecum. In this region,
the confluent small intestinal mesentery and right meso-
colon taper toward an apex at the ileocecal junction
(Figure9.8).
Mesoappendix: e mesentery attached to the appendix.
is arises from the under surface of the ileocecal mesen-
teric region (Figure 9.9).
Right mesocolon: Region of mesentery attached to the
right colon. Medially, it is contiguous with the small bowel
mesentery. At the hepatic exure, it continues as the trans-
verse mesocolon. e small bowel peritoneal reection is
the medial limit of the right mesocolon (Figure 9.10).
Ileocecal fl xure: Complex of intestinal, mesenteric, and
peritoneal structures where the ileum continues as the cecum.
Superior
rectal artery in
mesorectum
Mesosigmoid Left mesocolon
Inferior mesenteric adipovascular pedicle
Mesorectum
Inferior
mesenteric
artery
Figure 9.5 Inferior mesenteric artery adipovascular
pedicle as seen following mobilization in a cadaver.
Theinferior mesenteric artery continues distally as
the superior rectal artery once the left colic vessel has
branched off.
Adipovascular pedicle
Intestinal mesentery
Left mesocolon
Mesosigmoid
Mesorectum
Figure 9.3 View of intestinal mesentery in a cadaver.
Theregion demonstrated is the left mesocolon and
mesosigmoid, as well as the adipovascular pedicle of the
inferior mesenteric artery.
Splenic flexure
Mesenteric component
of splenic flexure
Transverse colon
Transverse
mesocolon
Left mesocolon
Peritoneal reflection
Left colon
Mesentery
Legend
Fascia
Colon
Peritoneum
Figure 9.4 (See also QR 9/1 and 2.) 2.5D snapshot of 3D
digital model of splenic exure. The exure has been con-
ceptually removed to demonstrate its component structures.
122 Operative nomenclature
Large intestine and associated mesentery
Transverse mesocolon
(a) (b)
Left
mesocolon
Splenic flexure
Mesosigmoid
Mesorectum
Mesoappendix
Figure 9.7 (a) (See also QR 7/3.) 2.5D snapshot of 3D digital model of large bowel and mesentery. (b) The intestinal
tract has been conceptually removed from the model used in (a), in order to demonstrate the intestinal margin of the
mesentery.
Adipovascular pedicles and avascular interpedicular regions
M
iddle colic pedicle
Right colic pedicle
Ileocolic
pedicle
(a)
(b)
Color code
Red, adipovascular pedicle
Yellow, avascular interpedicular region
Figure 9.6 (a) Postoperative specimen following a total mesocolic excision. Adipovascular pedicles and avascular interpe-
dicular areas are clearly seen. Both regions are highlighted in red and yellow, respectively, in (b).
Mesentery 123
Hepatic exure: Complex of intestinal, mesenteric, and
peritoneal structures where the ascending colon continues
as the transverse colon (Figure 9.11).
Transverse mesocolon: Mesentery attached to transverse
colon. It is formed by merging of the mesenteric compo-
nents of the hepatic and splenic flexu e, and the middle colic
adipovascular pedicle. e mesenteric component of the
hepatic and splenic flexu e coalesce with the adipovascular
pedicle of the middle colic vessel. e transverse mesoco-
lon is suspended at the origin of the middle colic artery and
extends toward its intestinal margin.
Splenic exure: Complex of intestinal, mesenteric, and
peritoneal structures where the transverse colon continues
as the descending colon (Figure 9.12).
Le mesocolon: Mesenteric region attached to the le
colon. e left colon provides a lateral limit. e medial
limit is formed by left edial peritoneal reection.
Proximal sigmoid exure: Complex of intestinal tract,
mesentery, and peritoneal reection where the descending
colon continues as the sigmoid colon (Figure 9.13).
Distal sigmoid exure: Complex of intestinal tract, mes-
entery, and peritoneal reection where the sigmoid colon
continues distally as the rectum (Figure 9.13).
Mesosigmoid: Mesentery attached to sigmoid. It is con-
tiguous above and below with the left mesocolon and meso-
rectum, respectively (Figure 9.14).
Mobile mesosigmoid: Mobile region of mesosigmoidal
mesentery attached to the sigmoid. It converges on the
attached region of the mesosigmoid (Figure 9.14).
Attached mesosigmoid: Region of mesosigmoidal
mesentery attached to (i.e., attened against) the retro-
peritoneum. It is a medial extension of the mobile meso-
sigmoid and the caudal extension of the left mesocolon
(Figure9.14).
Rectosigmoid junction: e transition between sigmoid
colon and upper rectum (Figure 9.15).
Mesorectum: e mesentery associated with the rec-
tum (Figure 9.15). It is a downward extension of the
mesosigmoid.
Mesoappendix(a)
Crohn’s disease
Mesoappendix
Figure 9.9 (a) Postoperative demonstration of the origin of the mesoappendix from the undersurface of the ileocecal
mesenteric conuence. (Continued)
Small intestinal mesente
ry
Right mesocolon
Ileocecal mesenteric region
Figure 9.8 (See also QR 1/1.) 2.5D snapshot of 3D digital
model of right mesocolon and small intestinal mesentery.
These are continuous and represent different regions of
the same structure.
124 Operative nomenclature
Right mesocolon
Section cut
See below
(a)
Peritoneum
Colon
Mesentery
Legend
Figure 9.10 2.5D snapshot of 3D (a) (See also QR 2/1.) digital model demonstrating the mesentery. (Continued)
Small intestiua
l
mesentery
Right
mesocolon
Mesoappendix
(b)
Figure 9.9 (Continued ) (b) View of the mesoappendix and its origin from the nearby mesenteric conuence after
mobilizing this from the posterior abdominal wall.
Peritoneal reection 125
PERITONEAL REFLECTION
e following description is not meant to indicate that
there are separate reections. e peritoneal reection is
continuous and distinct anatomic demarcations are not
apparent between regions. e following are the regions of
the peritoneal reection as they are currently understood.
Small bowel peritoneal refl ction: Peritoneal refl ction at
the base of the small intestinal mesentery where it curves onto
and becomes attached to the retroperitoneum (Figure 9.16).
Ileocecal peritoneal reection: Continuation of the small
intestinal peritoneal reection at the ileocecal exure where
it attaches exural regions to the posterior abdominal wall
(Figure 9.17).
Right peritoneal reection: Cephalad continuation of the
ileocecal peritoneal reection along the right paracolic gut-
ter and toward the hepatic exure (Figure 9.18).
Hepatocolic peritoneal reflection: Continuation of the
right peritoneal ref lection around the hepatic f lexure
where it attaches to the colic component of the flexure
(Figure 9.19).
Omentocolic reection: Peritoneal reection interposed
between the greater omentum and the upper surface of the
transverse colon (Figure 9.20).
Le peritoneal reection: Distal continuation of spleno-
colic reection along the left paracolic gutter (Figures 9.21
and 9.22).
Transverse
mesocolon
Small
intestinal
mesente
ry
Left mesocolon
Right mesocolon(b)
Figure 9.10 (Continued ) 2.5D snapshot of 3D (b) (See also QR 4/1.) right mesocolon.
Mesenteric component
of hepatic flexure
Peritoneal component
of hepatic flexure
Colic component
of hepatic flexure
Hepatic flexure
Legend
Mesentery
Fascia
Colon
Peritoneum
Figure 9.11 (See also QR 11/1,2.) 2.5D snapshot of 3D digital
model of hepatic exure. The exure has been conceptually
removed to demonstrate its component structures.