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328 Mesenteric considerations in ostomyformationand reversal
(a)
Exposed and mobilized
Reversal of ileostomy; mesenteric and peritoneal basis
(b)
Adhesions between
afferent and
efferent mesentery
afferent and
efferent mesentery
Figure 24.4 (a) Intraoperative appearance of a loop ileostomy following its circumferential detachment down to the level
of the true peritoneal cavity. Adhesions led to fusion of the afferent and efferent limb mesenteric surfaces. (b)Adhesiolysis
leads to separation of the afferent and efferent mesenteric surfaces and further exposes all intestinal and mesenteric
anatomy.
Reversal of ileostomy; mesenteric and peritoneal basis
(a)
(e)
Stoma formation and reversal 329
Mobilization of everted e˜ erent ileum
Half strength
Betadine
(d)
(b)
Excision of skin margin
Corner (stay) suture
Repair of serosal tear
(c)
Layer of interrupted seromuscular sutures
Figure 24.5 (a) Mobilization of the everted pole of the stoma by sharp division of adhesions between the skin and the
serosa. (b) Excision of the collar of skin around the stoma. (c) Irrigation of both afferent and efferent limbs with half
strength betadine to highlight any serosal tears or enterotomies. (d) Inverting seromuscular suture placed at the corner.
The orientation of the suture (as demonstrated) in conjunction with its seromuscular positioning leads to mucosal inversion
and serosal apposition. Both these effects are essential in avoiding leakage. (e) Full closure of the stoma enterotomy with
mucosal inversion and sero-serosal apposition throughout.
330 Mesenteric considerations in ostomyformationand reversal
SPECIAL CONSIDERATIONS
Ileostomy formation
Mesenteric anatomy is an important technical consideration in loop ileostomy formation and reversal. e position of a loop ileostomy, generally in the right iliac fossa, is
predicated on the mobility of the small intestine, which in
turn is a function of mesenteric mobility. e mesenteric
zone of attachment (i.e., from the duodenojejunal exure to
the ileocecal junction) is immobile. Mesenteric mobility is
a function of the lengthening that occurs at the intestinal
margin of the mesentery. If this is suciently lengthy, then
the ileum can be readily drawn through an aperture in the
right iliac fossa (i.e., if created as described earlier).
Mesenteric abnormalities can render ileostomy for-
mation technically challenging. In the rst instance, the
mesentery can be quite thickened (as occurs with visceral
adiposity, Crohn’s disease, diverticular disease, and in
intra-abdominal sepsis). ickening leads to a shortening
in radial and longitudinal length. In most circumstances,
a small segment of small intestine and mesentery can be
mobilized suciently to reach the anterior abdominal wall
but this may not be in the right iliac fossa. e nal position
is determined by the extent of mesenteric shortening.
e presence of considerable subcutaneous adiposity (oen accompanied by considerable visceral adiposity) poses a further technical challenge. e combination
of visceral and subcutaneous adiposity may mean that
the intestine and mesentery cannot be brought to the surface in a tension-free manner. One approach in this context is to divide the distal end of ileum and bring through
an end-loop ileostomy. Ileal division exposes the attached
mesentery which now opens out in a hinge-like manner.
e mesentery can be trimmed back a distance or divided
vertically through. ese maneuvers are usually sucient to
enable stoma formation in even the most challenging contexts. e solution to the technical challenge posed by the
combination of subcutaneous and visceral adiposity again
highlights the importance of mesenteric considerations in
colorectal surgery.
A bulky mesentery may impede stoma l eversion. Eversion
is essential in the prevention of stomal ssuring and ulceration. ere are a number of technical tips that help overcome this mesenteric issue. e rst is to ease the blade end
of a pick-ups forceps under the mucosa and compress the
mesentery enough to permit eversion. If this is not possible,
then the mesentery can be supercially desiccated using
diathermy (given it is comprised mainly of adipose tissue).
To achieve this, the coagulation setting is increased, and the
diathermy tip is placed at on the mesenteric surface and
activated. is can lead to a substantial reduction in mesenteric volume.
e bulky mesentery can impede suture placement
during stoma formation. To overcome this, the assistant
uses the blade end of an Adson tissue forceps to deect the
mesentery away from the dermal layer of adjacent skin.
As mentioned earlier, each stoma must be considered in
terms of intestinal and mesenteric components. Diculties
created by the mesenteric component are described earlier.
In general, the intestinal component is collapsible and thus
does not pose many problems. It does become problematic
when the bowel is edematous and, due to increased turgidity,
cannot be everted. is is sometimes seen in Crohn’s disease,
diverticular disease, and in intraperitoneal sepsis. No attempt
should be made to evert this stoma at the rst operation. e
serosa should be wrapped in a paran-based dressing (i.e.,
Jelonet). is is hydrophobic, which means the serosal surface does not dehydrate and ssure. With time, the edema
will settle (assuming the primary surgical issue has been dealt
with), and the stoma may be everted. If it cannot be everted,
then it will ultimately retract over a number of weeks.
Ileostomy reversal
Just as formation of a loop ileostomy is predicated on numerous
mesenteric factors, ileostomy reversal requires that the surgeon
be able to dierentiate mesenteric from subcutaneous fat. e
novice oen fails to make this distinction (dueto similarities
in the appearance of both) and either can be damaged. is is
always associated with bleeding which hinders identication
of planes and further increases the risk to the mesentery (and
hence the bowel). Similarities between the mesothelium of a
parastomal hernial sac and the fascia overlying the musculature
of the anterior abdominal wall further compound the diculty.
Once the stoma has been fully mobilized and exterior-
ized one frequently notes that the mesentery of the aerent and eerent loop have adhered. ese must be separated
bysharp dissection with care being taken to identify the
interface between both, avoiding entry into either. Again,
this requires an awareness of the mesenteric planes. Itmay
be that the adhesions formed between both mesenteric
surfaces are quite dense and that the violation of one
mesenteric surface is unavoidable. is should be limited
as much as possible to prevent vascular compromise and
ensure viability of the associated intestinal tract.
Transverse loop colostomy formation
is procedure is frequently required in the case of an
obstructing distal lesion where neoadjuvant treatment may
improve the oncologic outcome or in the palliative setting where systemic disease rules out obtaining oncologic
clearance. As a result, it is a relatively common procedure.
Notwithstanding this, it is may be poorly performed and
the resulting stoma frequently problematic for the patient.
One of the major challenges lies in dierentiating omental
from transverse mesocolic fat.
e key technical goal is to obtain sucient meso-
colic mobilization in order to enable tension-free delivery of the mesocolon to the abdominal surface. In the
obstructed and palliative context, it is feasible that the
transverse colon and mesocolon may be signicantly
displaced by the pathology in question. is can occur
References 331
in advanced peritoneal carcinomatosis where metastatic
deposits tether the transverse mesocolon to adjacent
structures. In anticipating this possibility, it is useful to
place a coin over the right upper quadrant and obtain a
plain lm of abdomen to determine the position of the
transverse colon relative to the coin. is simple maneuver helps in placement of the initial incision and can
obviate spending a considerable amount of time in locating the transverse colon and mesocolon intraoperatively.
As mentioned earlier, transverse loop colostomy is
generally performed in the right upper quadrant and fundamentally requires that the transverse mesocolon and
transverse colon itself are mobilized sufficiently as to
enable their easy (tension free) delivery on to the anterior abdominal wall surface. Thus, it can be argued that
the most critical point of the procedure is the freeing of
the transverse mesocolon from adjacent attachments.
Asdetailed in Chapter 2, the flexures are comprised of
four anatomic structures centered on a mesenteric confluence (peritoneum, colon, mesentery, and fascia) [6–8].
Inthe case of the hepatic flexure, the hepatocolic reflection
forms the most cephalad structure. It coalesces variably
with the greater omentum in this region. An additional
peritoneal reflection occurs between the greater omentum and transverse colon and further adhesions occur
between the undersurface of the greater omentum and
the cephalad aspect of the transverse mesocolon. Thus,
it is important that the greater omentum and colon (and
transverse mesocolon) are identified and this complex of
structures is carefully separated [9].
Once the transverse mesocolon and colon have been
freed from adjacent structures, the colon must be secured
in place. Approaches include placement of a rod, or red
rubber tube, across the mesentery. To place these, a window is created in the mesentery under direct vision. e
latter is important as the marginal vessel must be avoided.
Ideally, the window should be placed in an avascular
interpedicular region. e tip of an artery forceps is then
slowly introduced across the mesentery, and rather than
splitting the fat here, a nylon tape is grasped and brought
back across the mesentery. Next, the tape is grasped with
a Kocher’s clamp which is rotated anticlockwise. is is
drawn back across the mesentery and as one does so, it is
unwound clockwise. e eect is to atraumatically create a mesenteric channel through which a rod or tube can
be introduced. is technique is of particular importance
in exural regions where marginal vessels are relatively
attenuated and can be inadvertently compromised [2–5].
Difculty mobilizing the transverse colon
As mentioned earlier, patients requiring transverse loop
colostomy for palliative defunctioning may have considerable intraperitoneal disease. Oentimes, the presence
of peritoneal carcinomatosis, peritoneal, and mesothelial
tumor burden can be such that it is not possible to mobilize the transverse mesocolon enough to enable tensionfree delivery to the abdominal surface. If this is the case,
then attempts at mobilizing the transverse mesocolon
should be abandoned as it will lead to intraperitoneal
bleeding. isposes a technical challenge for the surgeon
as the position of the starting laparotomy does not readily
lend itself to ileostomy or sigmoid colostomy formation.
A solution is to extend the incision medially, identify the
small bowel and mesentery. Both are exteriorized enough
to enable dierentiation of aerent and eerent limbs.
Aloop ileostomy can usually then be constructed.
SUMMARY
Technical issues related to mesenteric and peritoneal
anatomy form the cornerstone of the surgical approach to
both stoma formation and reversal.
REFERENCES
1. Rostas, J.W., III, Preventing stoma-related
complications: Techniques for optimal stoma
creation. Seminars Colon Rectal Surg, 2012.
23(1):2–9.
2. Beck, D.E. etal., The ASCRS Textbook of Colon and
Rectal Surgery, 2nd ed. Springer, New York, 2011,
pp. 517–533.
3. Fazio, V.W., J.M. Church, and C.P. Delaney, Current
Therapy in Colon and Rectal Surgery. Elsevier
Mosby, the Curtis Center, Philadelphia, PA, 2005,
pp.549–556.
4. Milsom, J.W. etal., Laparoscopic Colorectal Surgery.
Springer, New York, 2006, pp. 304–313.
5. O’Connell, P.R., R.D. Madoff, and M. Solomon,
Operative Surgery of the Colon, Rectum and Anus,
Sixth Edition. CRC Press, Boca Raton, FL, 2015,
pp.227–344.
6. Culligan, K. etal., The mesocolon: A prospective
observational study. Colorectal Dis, 2012. 14(4):
421–428; discussion 428–430.
7. 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.
8. Coffey, J.C., Surgical anatomy and anatomic
surgery—Clinical and scientic mutualism. Surgeon,
2013. 11(4): 177–182.
9. Coffey, J.C. etal., Mesenteric-based surgery
exploits gastrointestinal, peritoneal, mesenteric and
fascial continuity from duodenojejunal exure to the
anorectal junction—A review. Dig Surg, 2015. 32(4):
291–300.
Mesenteric considerations in reoperative abdominal surgery
J. CALVIN COFFEY AND FEZA REMZI
25
Aims 333
Introduction 333
Special considerations 334
Reoperative surgery: Miscellaneous areas of
technicaldifculty 338
Circle the enemy.
Victor Fazio
AIMS
To demonst rate the importance of mesenteric a nd peritoneal
factors in reoperative abdominal surgery.
INTRODUCTION
Reoperative surgery is technically challenging and for this
reason oen referred onward by many surgeons. Most argue
that it should only be conducted in high-volume centers
where multidisciplinary support mechanisms are in place
[1–5]. e challenge with reoperative abdominal surgery lies
in adhering to a strictly anatomic approach. Multiple factors
contribute to this diculty including inaccurate descriptions
of mesenteric and mesocolic anatomy, diculty in dierentiating mesenteric from retroperitoneal and omental fatty
structures, the formation of adhesional complexes involving
numerous structures, and the displacement of fatty compartments (e.g., the retroperitoneum) into an adhesional complex. e challenges in reoperative intraperitoneal surgery
are compounded by the process of neoperitonealization
(Figure 25.1), where a new mesothelial surface is generated
between apposed structures [6].
If possible, a period of no less than 3 months should
elapse before reentering an abdomen following an operation.
In the setting of previous leak and intraperitoneal sepsis, one
should wait longer. e problem with reentering too early is
that adhesions are dense and vascular and it is not possible to
Reoperative surgery and postoperative complications 338
Reoperative surgery: Finding oneself unexpectedly in
the wrong plane 340
Summary 341
References 341
safely disentangle the intestine and mesentery, without damaging components of it. Over time, adhesions soen enough
to facilitate safe division (Figure 25.2) [7,8].
In considering early steps in reoperative surgery, that is,
laparotomy, it is important to rst focus on gaining entry
into the abdomen in a manner that minimizes serosal tears,
enterotomies, and mesenteric damage. It is best commenced
in a region that has not yet been surgically disrupted. is
is not always possible, and thus, a strategy may be required
to access the peritoneal cavity through an old scar. One
approach is to rst open the fascia (albeit supercially) and
place a Kocher’s clamp on this. e clamp is then lied vertically upward while concurrently displacing intra-abdominal
contents posteriorly (Figure 25.3). Usually, it is possible to
make a few millimeters progress here with the aim being
to separate the plane formed by (1) the underlying bowel
and (2) the overlying peritonealized fascia. Occasionally, it
may not be possible to dierentiate components that make
up this interface. Inthis circumstance, one should defer
further dissection in that region and commence dissection
elsewhere. Two other techniques can help. e rst is water
injection into an adhesion (popularized by Victor Fazio),
which sometimes has the eect of creating a plane at points
of least resistance. A second is to use the tip of a No. 15
blade to divide through the adhesion taking a component
of the fascia. e problem with this lies in the fact that it is
not anatomic, is frequently associated with bleeding, and it
does not aim to separate the components of the interface.
us, while it separates the intestinal tract from the anterior
abdominal wall, it does not permit or facilitate access to the
mesentery and it does not help in separating loops of small
bowel themselves. Nevertheless, when the surgeon cannot
333
334 Mesenteric considerations in reoperative abdominal surgery
Small bowel
Small bowel/neoperitonealization
Ileum
Interloop adhesions resembling fascia
Neoperitoneum
Figure 25.1 Neoperitoneum (adhesions) between small
intestine and anterior abdominal wall.
enter the true peritoneal cavity. It is not uncommon for the
distribution of midline wound-related adhesions to stop a
few centimeters lateral to the midline allowing the surgeon
to place his/her hand around them. In turn, this allows
the surgeon to circumvent regions of dense adhesions and
return to these at a point when greater leverage can be made.
Intuitively, a sound understanding of mesenteric anatomy,
irrespective of the location within the abdominal cavity, facilitates safe and reproducible reoperative surgery. Once mesenteric anatomy has been claried, then by denition so too has
that of the intestinal tract. In order to achieve this, the mesentery must be identied, then separated from adherent structures, without disrupting its integrity (Figure25.4). Although
each reoperative context has individual and specic technical considerations, the overriding importance of mesenteric
mobilization means that generalizations can be made.
It is important in reoperative surgery to withdraw from
further dissection, when it is not possible to safely achieve
complete intestinal and mesenteric mobilization. is is a
technically important decision and does not represent a
surgical failure.
SPECIAL CONSIDERATIONS
Ileum
Ileoileal
adhesions
Figure 25.2 Soft adhesions (readily divided) between
loops of small intestine.
advance further this non-anatomic technical trade-o may
be the only means of progression.
In general, adhesions are most dense in the midline where
laparotomy wound edges were brought into apposition
on closure of the abdomen (Figures 25.1 through 25.3). In
keeping with this and even in the most dicult of reoperative cases, lateral dissection leads the surgeon onto soer
adhesions. When these are divided the surgeon can then
In the above we have detailed the technical approaches to
obtaining safe mesenteric mobilization in the reoperative
context. ere are particular circumstances however in which
it is not possible to separate the mesentery from an adjacent
structure. is occurs whenever a pathological process has
generated an anatomic bridge that cannot be separated without either an en bloc multivisceral resection or disruption of
the pathology itself. A relatively common example is that of
a T4 intestinal cancer, which has extended locally beyond
normal anatomic boundaries to directly involve nearby structures. Further examples occur in advanced Crohn’s disease
where (as a result of stulation or perforation) the broinammatory process has extended into adjacent organs
or fat compartments. It is not uncommon in these circumstances for a stula to develop behind the terminal ileum, and
for this to penetrate through the iliopsoas muscle. A similar
phenomenon occurs in diverticular disease, where perforation through adjacent bladder leads to stula formation.
Several mesothelial phenomenon must be borne in mind
in reoperative surgery. For example, the peritoneum overlying
the mesentery oen thickens. is eect appears more pronounced in lateral peritoneal regions and may be explained by
prolonged and uninterrupted contact between two mesothelial
surfaces (Figure 25.5). Neoperitonealization, or neomesothelialization, create further diculties as newly formed peritoneum may resemble parietal peritoneum. In general, traction
and countertraction in this region demonstrate the interface
formed between neomesothelium and parietal mesothelium
(Figure25.6). Once the interface is identied then its contiguous components can be sharply divided. is can oen take
some time as the neomesothelium/peritoneal interface is oen
extensive and can span entire paracolic regions from pelvis to
upper quadrants.
(a)
(b
(c)
ted posteriorly
Opening the abdomen
Special considerations 335
Entering abdomen
between fingers
Entering abdomen
over ÿngers
Midline fascia
)
Adhesions to midline
laparotomy
Midline fascia
Adherent organs
de°ec
Figure 25.3 (a) Opening the abdomen by diathermy dissecting between two ngers placed beneath the midline wound.
(b) Opening the abdomen by dissecting (using diathermy) onto a nger placed beneath the midline wound. (c) Small
bowel and omentum swept off the undersurface of the midline wound. Sweeping the small bowel away enables the surgeon place ngers beneath the midline wound for opening.
336 Mesenteric considerations in reoperative abdominal surgery
Neoperitonealization II
Ileum
Differentiating mesentery
of adhesion
(countertraction)
Traction/countertraction and sharp division
Mesentery
Plane/interface
Figure 25.4 Small intestinal mesentery after separation
via adhesiolysis. The mesentery had folded back onto
and adhered to itself across adhesions. Once the latter
were divided the mesentery was visualized. Importantly,
adhering to an anatomic and planar dissection meant the
mesentery remained intact and was not breached.
Anterior wall
retracted away
(traction)
Ileum retracted in
opposite direction
Adhesions
exaggerated
Neoperitoneum
Figure 25.5 Neoperitoneum formed at the left lateral
ank, between underlying small bowel and adjacent
abdominal wall.
Not uncommonly, the attachment of neomesothelium
to parietal peritoneum is also thickened. is occurs following radiation exposure, in cases of peritoneal dialysis,
or following a localized postoperative infection (such might
occur aer a contained leak). Neomesothelialization oen
extends over the serosal surface of the intestinal tract and can
Figure 25.6 Demonstration of plane of dissection by trac-
tion on the anterior abdominal wall and countertraction
on the small bowel and mesentery.
resemble peritoneum. Given this overlap in appearance, the
surgeon may inadvertently create a serosal tear or full thickness enterotomy. ese can have major consequences in the
setting of an obstructed bowel. is is because perforation
here is followed by rapid decompression (under pressure) and
widespread intraperitoneal contamination. When operating
in regions of prominent neomesothelization, it is important
to bear intestinal and mesenteric proximity in mind. If adhesions are too dense for component separation, then a technical compromise can be achieved by going outside the parietal
peritoneum and excising this in an en bloc fashion.
ere is a temptation to repair a serosal tear or enter-
otomy immediately, thus minimizing any potential contamination. It is reasonable to close a defect temporarily as
continued dissection may be associated with a widening of
the defect. is also minimizes potential contamination.
If the full anatomic extent of the enterotomy is apparent
it is reasonable to repair it immediately. Before repair, the
mucosa should be trimmed back to healthy mucosa. If the
full anatomic extent of the enterotomy is not apparent, no
attempt should be made to close it at that point. Attempts at
repair, that is, in the absence of complete gastromesenteric
mobilization, are associated with incorporation of either
small bowel or mesentery. is increases collateral tissue
damage and renders further mobilization more dicult.
e strategy in this context should be to gently appose free
Special considerations 337
/
Fascial and peritoneal similarities
(a)
(b
(c)
edges but leave the sutures long. ese serve as a reminder
that once full intestinal and mesenteric mobilization have
been completed, a denitive repair must be conducted.
Adhesions vary in composition and hence appearance.
In some regions they resemble peritoneum (see above for
neoperitonealization) while in others they resemble Toldt’s
fascia (Figure 25.7). is can sometimes lead to confusion
as the fascia ordinarily is conned to the undersurface of
the mesentery where it is adherent to the retroperitoneum.
During reoperative surgery and mobilization of the mesentery, it is important that the surgeon avoids mesenteric
trauma as much as is feasible. One of the main problems with
mesenteric damage lies in loss of hemostasis. While blood
loss itself is not excessive, blood will obscure fascial planes.
As this may be unavoidable, the surgeon must have strategies
set in place to safely clear blood without impeding the surgical process. Frequent irrigation with saline or water (using a
50 mL bladder syringe) usually achieves this. e pressure
of the jet clears the region in question and native anatomy
is more readily identied and dierentiated. In addition,
bleeding vessels can be more readily identied for a targeted
suture ligation.
Occasionally, adhesions can obscure bleeding points from
direct view. It is important to never place sutures in a blind
Adhesions
resembling
fascia
Adhesions
resembling
fascia
)
Adhesions
resembling
peritoneum
re˜ec tion
Figure 25.7 Adhesions resemble either Toldt’s fascia (a and b) or peritoneum (c).