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18 The Failed Anastomosis
283
Weakly associated patient-related risk factors include
age, tobacco and alcohol use, and obesity [
felt to be a risk factor at all in right-sided resections; however, there tends to be a more signifi cant association with
rectal resections [ 21 ]. A combination of risk factors may
yield even more signifi cance. This is likely why a higher
American Society of Anesthesia (ASA) classifi cation (usually scores of 3 or more) is one of the more consistently
found risk factors for leak [ 20 ]. Likewise, patients with
Charleston Comorbidity Index scores of 3 or more have also
been found to have signifi cantly higher anastomotic leaks
[ 17 ]. These and other types of scoring systems might be
more useful indicators of a patient’s risk of anastomotic leak.
20 ]. Obesity is not
Poor Nutritional Status
Key Concept : Nutrition is a potentially modifi able risk factor
that can often be improved prior to surgery . Its impact on
anastomotic leak is somewhat variable , but poor nutrition is
commonly associated with higher rates of leak , specifi cally
for right - sided resections .
Certain preventive measures can be taken even before the
operation is begun to reduce the risk for leak, primarily in the
elective setting. Wexner suggests that these preventive measures are more commonly encountered preoperatively in a
right colectomy and intraoperatively in a left colectomy [ 22 ].
This statement has been further validated by other studies,
including one multicenter prospective trial [ 23 ]. Identifying
those patients who are of poor nutritional status and treating
them preoperatively may reduce the risk for and the morbidity and mortality from anastomotic leaks [ 23 ]. Generally,
poor nutritional status has been defi ned in the literature as
weight loss ≥10 %, serum albumin <3.5, and serum proteins
<5.5 g/dL [ 24 – 27 ]. It is important to defi ne what level of
severity of malnutrition requires preoperative nutritional
support. Most studies have used a weight loss of ≥10 % to
defi ne malnutrition [
this only represents the cutoff value for which complications
are seen to increase [
may be a better indicator of severe malnutrition for which
preoperative nutrition is indicated. Parameters which are
used in the NRS include weight loss in the last 3 months,
decrease in food intake, body mass index, severity of disease, and age. Thus, a 65-year-old patient with colon cancer
who has greater than 15 % weight loss in the last 3 months
and needs a right colectomy would have a score of 5. With
this scoring system, Jie found that in those patients with a
NRS ≥5 and a lower GI resection, preoperative nutrition
decreased the complication rate from 45 % in the control
group to 27 % in those patients with preoperative nutrition
[ 28 ]. An in-depth discussion regarding the impact of nutri-
tional support can be found in Chap.
28 ]. However, according to Jie et al.,
28 ]. The nutritional risk score (NRS)
3 by Dr. Maykel.
Immunosuppression
Key Concept : Patients with malignancy and infl ammatory
bowel disease often require surgical resection and are commonly immunosuppressed or taking immunosuppression
agents preoperatively . You need to have a thorough understanding of how this can impact postoperative morbidity
including anastomotic leaks .
Steroids
Corticosteroids decrease the activation and infi ltration of
infl ammatory cells into wounds along with inhibiting certain
growth factors that are necessary for collagen synthesis [ 29 ].
Intuitively it would seem that corticosteroids impair anastomotic healing; however, their exact effect on anastomotic
leaks is less clear. Multiple studies have shown no increased
risk with preoperative steroid use [
mainly retrospective and include patients with variable dose
and duration of steroid usage and type of operation performed.
A more recent prospective study found that both long-term
and perioperative usage are associated with a higher risk of
anastomotic leakage [
increase the rates of wound infections and septic complications [ 36 , 37 ]. If possible steroids should be weaned preopera-
tively, and you should more readily consider proximal
diversion (especially in the case of a rectal anastomosis).
35 ]. Steroids have also been shown to
30 – 34 ]. These studies are
I n fl iximab, AZA, 6-MP
There does not seem to be an association with anastomotic
leaks or other postoperative complications with the use of
infl iximab, though this is controversial. This holds even
when infl iximab is used in combination with azathioprine or
6-mercaptopurine [ 32 , 36 ]. There does not seem to be any
benefi t in stopping these medications preoperatively or
delaying surgery in Crohn’s patients. However, infl iximab
has been shown to negatively impact outcomes after operations for ulcerative colitis [ 38 ].
Crohn’s Disease
Key Concept : In addition to the pathophysiology of the disease itself , the Crohn ’ s patient is likely to present with other
risk factors for anastomotic leaks including preoperative
malnutrition and immunosuppressive medication use .
Multiple studies have shown a high risk of intra- abdominal
septic complications in patients with Crohn’s disease [ 39 ,
40 ]. Other risk factors which are much more specifi c to
Crohn’s disease include a hand-sewn anastomosis, end-toend anastomoses, histologic positive margins, penetratingtype disease, and the need for sigmoid resection [ 20 , 30 , 34 ,
41 ]. We recommend stapled side-to-side anastomoses
when performing an ileocolostomy and to highly consider
284
N. Smallwood et al.
performing proximal diversion in cases where both small
bowel and sigmoid resections are needed. Grossly histologic
negative margins are almost impossible to achieve in a patient
with Crohn’s disease without causing unnecessary bowel
resection. A grossly negative margin, as indicated by the soft,
thin mesentery at the point of resection, is adequate.
Radiation
Key Concept : Radiation alone may not increase the risk of
leak , and does not mandate the need for diversion , typically ,
unless when combined with chemotherapy .
Neoadjuvant radiotherapy in the pelvis may result in
increased risk of anastomotic leak; however, this belief has
not been defi nitively established in the literature [ 42 ]. A
study that looked at 1,338 patients with rectal cancer over a
30-year period was unable to fi nd any signifi cant association
between neoadjuvant radiotherapy and anastomotic leaks.
Other factors such as location and size of tumor were found
to be of more signifi cance. This has been confi rmed in other
reports, including a fairly large randomized trial [ 43 ]. There
is no need for routine diversion in patients who have received
neoadjuvant radiotherapy alone. If chemotherapy is added to
the radiation, a higher risk is likely, and a diverting stoma is
recommended. As will be further discussed later, proximal
diversion does not prevent a leak but reduces its impact.
Diverticulitis and Emergency Surgery
Key Concept : Although emergent surgery is a well - known
risk factor for complications , diverticulitis may be an independent risk factor for anastomotic leak .
Diverticulitis and emergency operations have previously
been identifi ed as risk factors for anastomotic leaks [ 44 – 47 ].
Emergency operations are at an increased risk of postoperative complications in general, which include wound infections, intra-abdominal abscesses, anastomotic leak, wound
dehiscence, and mortality [ 44 ]. In addition, other risk factors
such as the disease process itself, location of the anastomosis
to be performed, and condition of the patient play a role in the
development of a leak. Diverticulitis commonly involves
some of these same factors but may be an independent risk
factor for leak, even in nonemergent conditions. This
increased risk may be due to persistent infl ammation or unresolved abscesses at the time of the operation and decreased
anastomotic strength due to an increase in wall thickness secondary to muscular hypertrophy and an inappropriate selection of staple height [
is avoiding any retained sigmoid on the rectal stump. An
anastomosis between the left colon and soft rectum is essential to cure diverticulitis and prevent an anastomotic leak.
23 ]. One preventable risk factor for leak
Peritonitis
It is a commonly held belief that an anastomosis created in
the setting of peritonitis will be at increased risk of anastomotic dehiscence [ 48 , 49 ]. However, previous animal studies
and other clinical studies have failed to show any increase in
risk of leaks in the setting of peritonitis [ 49 , 50 ]. There may
be a difference between purulent versus fecal peritonitis
(e.g., Hinchey III vs. IV) and the risk of leak, as previously
reported by Biondo and colleagues [ 50 ]. In a follow-up
study, they were able to perform a primary resection and
anastomosis with a respectable 5.7 % leak rate without the
use of proximal diversion in patients with purulent peritonitis. They excluded those with fecal peritonitis, as well as
ASA IV, and unstable or immunocompromised patients. Of
the remaining 208 patients, 50 % of the patients had peritonitis, of which half of these had diffuse peritonitis. Peritonitis
was not found to be an independently associated risk factor
for anastomotic leaks [ 47 ]. At present it does not appear that
purulent peritonitis alone is a risk factor for anastomotic leak
[ 47 , 50 – 52 ].
“Loaded Colon”
One of the reasons why emergency surgery is felt to be associated with higher leaks is that these operations are performed on the unprepped colon. The “loaded colon” has
been reported to have up to a threefold increase in anastomotic leaks [ 53 ]. This is contradictory to the most recent
studies on mechanical bowel preparation that have concluded that it can be safely omitted. Methods such as intraoperative colonic lavage have been shown to have a positive
effect on anastomotic integrity and collagen metabolism and
can allow for a primary anastomosis to be performed without
diversion in emergency operations for colonic obstruction
[ 49 , 54 ]. Until additional evidence to the contrary emerges, it
is recommended that colonic lavage be performed when distal colon and rectal anastomoses are created in the “loaded
colon.” In contrast, elective operations to remove the left
colon or rectum can be safely performed with only enemas
(without a complete bowel preparation) to empty the stool.
Hemodynamic Instability
Since the healing anastomosis is extremely dependent upon
adequate perfusion, episodes of hypotension, and especially
those requiring vasopressors, should be an absolute indication for preventive measures. In fact, shock was one of the
only two risk factors for which proximal diversion would be
needed, according to an AAST multicenter trial, in the cases
of traumatic injuries to the colon [
55 ].
18 The Failed Anastomosis
285
In the majority of emergency or diverticular operations—
in the absence of either fecal peritonitis or shock—a primary
resection and anastomosis can be performed safely. Lower
rates of anastomotic leak, re-interventions, and other wound
infections are seen with proximal diversion when other risk
factors are present. As previously stated, intraoperative
lavage is recommended for emergency resections involving
the impacted left colon to allow primary anastomosis [
20 ].
Location
The site of the anastomosis has been the most consistent and
signifi cant risk factor for anastomotic leak [ 56 ]. The further
distal an anastomosis is created, the higher the risk of leak.
An ileocolic anastomosis has a leak rate of 2–3 % compared
to a 10–17 % leak rate in coloanal anastomosis. Even in rectal anastomoses, a signifi cant difference can be seen the
closer the staple line gets to the anal verge [ 56 ]. The highest
risk of anastomotic leak can be seen for anastomoses at and
below 5–8 cm from the anal verge [ 23 ].
There are several proposed reasons for the difference in
leak rates between proximal and distal locations including:
1 . Increasing amount of intraluminal bacteria from proxi-
mal to distal colon [ 23 ]
2 . Absence of peritoneal cover in distal rectum [ 23 ]
3 . Compromised vascularity to distal rectal stump espe-
cially posterior [ 23 ]
4 . Increased intraluminal pressure of rectum during a closed
anal sphincter and defecation
Obesity and Male Gender
Key Concept : These two risk factors for leak are primarily
seen in association with a low rectal anastomosis .
Obesity is known to be a risk factor for postoperative
wound infections, prolonged open operations for rectal resection, and conversion from laparoscopic to open [ 57 ]. While
obesity is variably associated with anastomotic leakage, there
is considerable evidence that obesity affects the leak rate for
low rectal anastomoses. In several studies, obesity has been
shown to be the strongest risk factor for the development of a
leak [ 21 , 58 , 59 ]. Additionally, the male gender is mainly
found as a risk factor for problems with low rectal anastomosis and usually is not found to be signifi cant for more proximal anastomoses [ 23 , 60 – 62 ]. Both obesity and male gender,
and more specifi cally the deep narrow male pelvis, can make
low rectal operations signifi cantly more diffi cult. Men also
may be at increased risk of poor anastomotic perfusion. It is
known that men can have altered intestinal microcirculation
in response to hormones and are at an increased risk of
advanced atherosclerosis compared to women [
63 ].
Operative Risk Factors
Key Concept : There is no method of intestinal anastomosis
that is leak free . Although you have a somewhat limited ability to prevent anastomotic leaks , your performance at the
time of the operation can have a major infl uence .
Blood Loss, Transfusions, and Operative Time
Key Concept : One way you can reduce the risk of anastomotic failure during the operation is by limiting intraoperative blood loss and the time it takes to perform the
operation .
While both of these parameters have been confi rmed to
decrease leak rate on multivariate analysis [ 64 , 65 ], the actual
signifi cance is not completely clear, as this has not been uniform across the literature [ 66 , 67 ]. Furthermore, the actual
amount of blood loss or duration of operation that matters is
much less clear. Operative times found to be of signifi cance
ranged from 120 to 270 min [ 17 , 24 , 66 , 67 ], while meaningful
operative blood loss has been defi ned as that which requires
blood transfusion—a highly variable defi nition [ 17 ]. What
seems clearer is that increased operative time leads to more
exposure of the patient to tissue trauma and bacteria [ 25 ] and
correlates with hypothermia in most patients. Primary hypothermia correlates with increased infectious complications and
hospital length of stay [ 68 ]. Even more, increased operative
times and greater amounts of blood loss are surrogate markers
for the degree of diffi culty of the surgery. You must be mindful
of these objective indicators of a more diffi cult operation in
order to accurately decide whether or not to perform proximal
diversion. While occasionally viewed as a “failure,” it is never
wrong to err on the side of diversion.
Intraoperative Complications
Key Concept : Adverse events during the operation , even if
not directly involving the anastomosis , can increase the risk
of anastomotic leak .
Trencheva et al. defi ned an intraoperative complication as
injury to the bowel, other organs, or blood vessels. In addition, stapling device malfunction, hypotension, oxygen saturation less than 90 % for more than 5 min, pH less than 7.3,
and even blood loss requiring intraoperative blood transfusion were also classifi ed as an intraoperative complication.
In their series, any patient with an intraoperative complication was four times as likely to have an anastomotic leak
17 ]. On one hand, this may again be a surrogate for a more
[
diffi cult operation. More appropriately, this highlights the
degree of interconnectivity among all aspects of an operation
and the impact one problem can have on another.
286
N. Smallwood et al.
Total Mesorectal Excision (TME)
Key Concept : Although oncologically sound , TME results in
a lower anastomosis and the potential for loss of blood supply that may increase the leak rate .
During the widespread adoption of total mesorectal excision, there was a substantial rise in leak rates from the previously reported 9 to ~23 % [ 69 ]. Over the next 4 years
following this initial study, the leak rate eventually did return
to the level seen before TME [ 69 ]. A study looking at laparo-
scopic resections showed that the addition of TME more
than doubled the leak rate for upper rectal cancer [ 67 ]. TME
for high rectal cancer may result in insuffi cient blood supply
to the posterior portion of the proximal rectum, which is further evidenced by the fact that tumor-specifi c mesorectal
excisions have lower rates of anastomotic leaks [ 15 , 70 ].
Tension and Splenic Flexure Mobilization
Key Concept : Avoiding tension has been classically viewed
as one of the fundamental principles of a healing anastomosis and remains a signifi cant preventative measure in reducing anastomotic leak .
The colon seems to be especially effected by applied tension, even more so than the small intestine. Blood fl ow did
not return to preoperative levels until the seventh postoperative day following experimentally applied tension in animal
studies [ 71 ]. Mobilization of the splenic fl exure has com-
monly been used to decrease tension in the rectal anastomosis. Karanja et al. found a 9 % leak rate with splenic fl exure
mobilization compared to 22 % without mobilization [ 72 ].
Additional evidence supporting its actual signifi cance is limited. The anastomosis is subjected to other sources of tension
during peristalsis and defecation that result in radial tension
for which splenic fl exure mobilization would seem to provide less benefi t. The major importance in splenic fl exure
mobilization may ultimately be improved blood supply of
the descending colon (rather than the sigmoid) when used for
the colorectal anastomosis.
Drains
Key Concept : Drains may be useful in low extraperitoneal
anastomosis , but are not typically indicated when the anastomosis is intraperitoneal .
The use of drains has been extensively debated over the
last decade, largely because they offer both real and theoretical benefi ts and risks, yet are only one of many factors that
play a role in a proper anastomosis. Furthermore, they are
widely variable in their use, type, and rationale for placement.
There is extensive evidence that draining an intraperitoneal
anastomosis is of no benefi t [
tamination or abscess at the time of resection, the intraperitoneal anastomosis should be created in a less hostile location
and after extensive contamination control. Draining the pelvic anastomosis may be of some benefi t. The pelvis does
seem to be unique as compared to the abdominal cavity in
that fl uid is much more likely to accumulate in the most
dependent area of the pelvis around the anastomosis and the
non-peritonealized pelvic fl oor fails to absorb fl uid effi ciently [
drains remove this fl uid or what impact this has on the healing anastomosis [ 17 , 47 , 74 ]. The other proposed benefi t of
draining the pelvic anastomosis is detection of an anastomotic leak. On one hand, studies have shown that drains
have very poor detection rates and that other clinical signs
are more likely to appear before any change in drain effl uent
[
where drains detected a leak in 80 % of patients and in 40 %
of cases this preceded any other clinical signs [
most recent meta-analysis, there was not enough suffi cient
evidence to indicate that drains are able to prevent anastomotic leaks or other anastomotic complications; however,
the authors acknowledged the need for more randomized
control trials specifi cally looking at lower rectal anastomosis
[ 66 ]. It is our practice to use drains selectively in cases where
build up of fl uid in the pelvis begins during the case despite
good hemostasis or after a very bloody operation where
every vessel could not have been controlled. In general, we
remove the drains once the effl uent is less than 15 cc/day or
if clear.
47 , 73 ]. However, it is unclear how effectively our
61 ]. Others have shown some benefi t in leak detection
69 ]. In the case of gross con-
75 ]. In the
Laparoscopy
Key Concept : Laparoscopic approaches with experienced
surgeons may result in a decrease in leak rates .
A study using the Nationwide Inpatient Sample population database found a decrease in the rate of anastomotic
leak along with a corresponding decrease in wound infection following laparoscopic surgery, despite an increased
leak rate with conversion to open surgery [ 76 ]. The recently
published Danish nationwide cohort study demonstrated an
increase risk of leak with minimally invasive approaches;
however, this study was performed during the period when
the laparoscopic method was fi rst being used [ 77 ]. While no
defi nite conclusion can be drawn, this latter study does
highlight the potential impact that inexperience can play in
leak rates. Interestingly anastomotic leaks have been diagnosed earlier following laparoscopic surgery, and as a result
of the primary operation being laparoscopic, laparoscopic
management of the leak was possible [ 67 ]. A possible cause
of low rectal anastomotic leaks in totally laparoscopic cases
may be the use of multiple fi rings of the endoscopic stapler
18 The Failed Anastomosis
287
to transect the rectum. Crossing staple lines and poor perfusion always put an anastomosis at risk, regardless of the surgical approach.
Omental Wrapping
Key Concept : Wrapping the anastomosis with a well vascularized pedicle of omentum has been associated with
decreased leaks in small studies .
Animal studies have proven the unique ability of the
omentum to adhere to and effectively bridge the anastomosis
[ 78 , 79 ] and allow for absorption of fl uid [ 80 ]. Some have
cautioned its use secondary to the likely negative impact in
cases where the omental pedicle is devascularized [ 80 ]. The
most recent meta-analysis found a signifi cant reduction in
clinical anastomotic leak only. Issues involving blinding and
a small number of patients within each study limited the
strength of the conclusion. Omentoplasty should be left up to
the surgeon’s personal experience.
Simultaneous Liver Resection
Key Concept : Staged resections may decrease the overall
morbidity and leak rate for extensive disease , while simultaneous resection is generally safe in carefully select patients .
Synchronous liver metastases are present in 23–51 % of
newly diagnosed patients [ 81 ], and liver resection remains
the best option for those patients with resectable disease
[ 82 – 84 ]. Staged procedures have been the traditional
approach [ 83 ]. Most studies evaluating safety and effi cacy
are retrospective and therefore suffer from selection bias
resulting in more extensive liver resections in the group of
patients with a staged approach to extensive liver resections [ 83 ]. These studies do show that limited liver resec-
tions can be performed at the same time as the colon
resections with equivalent morbidity and mortality [
84 ]. With more extensive liver resections and in those
70 years or older, the morbidity and mortality signifi cantly
increase, favoring a staged approach [ 82 ]. Age and exten-
sive liver resections seem to be the main factors to consider when deciding upon a staged versus simultaneous
resection. Leak is just one of the many causes of postoperative morbidity and mortality. The only study focused on
anastomotic leak after simultaneous liver resection showed
an operative time greater than 8 h was the most signifi cant
risk factor for anastomotic leak regardless of the extent of
the liver resection. The majority of leaks occurred with
rectal resections (36 % leak rate). Patients with colonic
resections were observed to have a 13 % leak rate, but this
was still higher than those patients who only underwent a
colonic resection [
82 ].
82 –
Proximal Diversion
Key Concept : Understand your goal with diversion , where it
is a crucial part to minimizing morbidity and where it can be
safely avoided . When you feel you need to proximally divert
a patient , it is generally a good idea .
The effectiveness of proximal diversion, whether a
loop colostomy or loop ileostomy, is highly debated. Most
studies have focused on whether proximal diversion can
prevent anastomotic leak. Some have suggested that proximal diversion does not prevent, but only minimizes the
clinical impact of leaks [ 85 ]. In a systematic review by
Montedori, proximal diversion was found to be useful in
preventing both anastomotic leak and the need for urgent
reoperations [ 86 ]. Proximal diversion also minimizes the
clinical impact of leaks by decreasing the leak rate and the
need for laparotomy. Unfortunately, there is also added
morbidity with proximal diversion. Problems ranging
from dehydration and electrolyte abnormalities to
mechanical problems can be as high as 30 % [ 86 ], result-
ing in an 18 % readmission rate [ 87 ]. In addition, there is
a 15–20 % complication rate with ostomy closure [ 88 ,
89 ]. Because of its associated morbidity, proximal diver-
sion should not be routinely performed. The decision for
proximal diversion must be carefully weighed against the
negative impact of leak and the morbidity of an ostomy.
This decision-making process can be simplifi ed by focusing on three key questions.
1 . What is the risk of leak based upon the location of the
anastomosis ?
Extraperitoneal anastomoses and those within
5–8 cm from the anal verge are at the highest risk of a
leak and should generally be diverted [ 23 ]. Leaks at this
level can negatively impact future bowel function and
increase the risk of a permanent stoma [ 90 ]. The deci-
sion to divert more proximal anastomoses should be
based upon the presence of other additional risk
factors.
2 . Can the patient tolerate a leak ?
Older patients and those with multiple medical comorbidities should be considered for proximal diversion.
These patients typically have very little physiologic
reserve to tolerate a leak.
3 . What are the patient wishes ?
It is important to include the patient in your
decision- making. Some patients are adverse to any
stoma, temporary or not. Others may be more
concerned with the complications from a leak than
with having an ostomy. A fully informed patient will
be able to better voice their own concerns and be much
more satisfied with the eventual outcome. Knowing
what the patient wants can simplify intraoperative
decision-making.
288
N. Smallwood et al.
Mechanical Bowel Preparation (MBP)
Key Concept : MBP does not signifi cantly impact anastomotic leak rates in colon resection , but may decrease complications with rectal resections , and likely should be continued
when possible for elective rectal cases .
Multiple studies have concluded that mechanical bowel preparation (MBP) in elective colon resections does not signifi cantly
impact anastomotic leaks [ 91 ]. The evidence is overwhelmingly
in favor of abandoning the use of MBP in colon resections. There
is less evidence for the effectiveness of MBP in rectal resections.
Some studies have shown that MBP can be safely omitted in
rectal resections [ 92 , 93 ], but most studies have excluded patients
with a rectal anastomosis [ 91 ]. A multicenter randomized con-
trolled trial showed a higher risk of infectious complications
without MBP [ 94 ]. They also showed a nonsignifi cant increase
in clinical anastomotic leaks and pelvic sepsis [
would be wise to continue mechanical bowel preparation, when
possible, for planned rectal resections.
The results of these studies also do not address some of
the other potential benefi ts of mechanical bowel preparation.
A well-prepped bowel allows for:
• Better visualization when intraoperative colonoscopy is
needed
• Easier creation, visualization, and leak testing of an anas-
tomosis when using an EEA stapler
• Easier bowel manipulation during laparoscopic surgery
94 ]. For now, it
Prevention
Laser Fluorescence Angiography
Following injection of fl uorescent dye, a mounted camera
with an infrared fi lter is used to view the resected ends or
newly created anastomosis. Special software can be used to
compare two different areas of perfusion. A study showed
that using the IC-View system® (Pulsion Medical System,
Munich, Germany) changed the site of resection in 16 % of
patients [ 97 ]. Other available forms of fl uorescence angiog-
raphy include the Spy Elite® (Lifecell, Bridgewater, NJ) for
open surgeries and the Firefl y TM used in the DaVinci® Si TM
Surgical System Robot (Intuitive Surgical, Sunnyvale, VA).
Intraoperative Air Leak Test
Studies assessing the effectiveness of air leak testing have
shown mixed results [
usefulness and no downside. In a large retrospective cohort
[ 101 ], untested anastomoses had twice the rate of clinical
leak than those that were tested. Patients who underwent
suture repair after a positive air leak test had a clinical leak
rate of 12.2 % compared to 3.8 % for patients with a negative
air leak test. Patients who underwent anastomotic revision or
proximal diversions after a positive air leak test had a 0 %
clinical leak rate [ 101 ]. This study provides signifi cant evi-
dence for the use of intraoperative leak testing. A diverting
ostomy should always be a consideration with positive air
leaks.
98 – 100 ], though typically demonstrate
Dr. Abbas has questioned whether surgeons should continue
to accept the risk of anastomotic leaks [ 95 ]. Surgeons have
been faced with similar questions in the past. Early surgery
for appendicitis was fraught with major diffi culties due to
poor diagnostic methods and no available methods of antisepsis. This was a time period when abdominal surgery was
performed only as a last resort. In 1881, W.A. Byrd stated “I
fail to fi nd any recorded cases in which this procedure (laparotomy) has been attempted with success… medicine is useless in these cases except for the production of euthanasia,
and surgery cannot even accomplish this.” Six years after
this statement, a successful appendectomy was performed by
Thomas Morton [ 96 ]. It is important that we not become
complacent but continually strive to break new barriers.
Intraoperative Anastomotic Assessment
Key Concept : Several methods are available for investigating the integrity of the anastomosis . Whatever method you
choose , it should be , in general , a routine part of your practice for all left - sided anastomosis .
Intraoperative Endoscopic Assessment
Li et al. [ 102 ] looked at the selective versus routine use of
endoscopic examination in bowel resections. Endoscopic
examination with air leak testing was performed on the preresected bowel, the rectal stump, and the post-anastomotic
bowel. This study showed a nonsignifi cant increase in leaks
(5.1 % vs. 0.9 %) with selective versus routine endoscopic
examination. The endoscope compared to the proctoscope
provides better visualization of the anastomosis and likely a
better assessment of its integrity.
Intraoperative Dye Test
Using a 22 French Foley, a mixture of sterile water and blue
dye is injected intraluminally, while the bowel proximal to
the anastomosis is clamped. It takes a volume of 180–
240 mL to adequately distend the anastomosis. A study
using this method found that the dye test allowed for the
easier detection and localization of leaks compared to air
leak testing [
103 ].
18 The Failed Anastomosis
289
Intraluminal Devices
Key Concept : These devices are either early in their experience or have not demonstrated a marked benefi t to reducing
leaks .
Transanal Decompression Devices
These devices are believed to decrease intraluminal pressure
by keeping the anal sphincter open. Rectal tubes, usually a
Foley catheter, are placed 15 cm above the anastomosis.
They provide for both decompression and antibiotic irrigation [ 104 ]. There are no comparative studies evaluating the
use of rectal tubes. Transanal stents are 4 cm in length and
left in place for 5–7 days following insertion [ 105 ]. A pro-
spective randomized study in 2006 was prematurely stopped
due to an increase in leaks in the stent group [ 106 ].
Intraluminal Barriers
Intraluminal barriers prevent the fecal stream from contacting the healing anastomosis. Animal studies have shown that
fecal contact negatively impacts the healing [ 52 ]. In animal
studies, the Coloshield and the Valtrec-Secured Intracolonic
Bypass (VIB) have both been very effective in preventing
leaks. Leaks were prevented even when an incomplete anastomosis was intentionally created [ 105 ]. Both devices are
secured proximal to the anastomosis and are spontaneously
expelled. Multiple small studies have shown a 0–8.7 % anastomotic leak rate with the use of the Coloshield. These
authors claim the Coloshield is a viable alternative to fecal
diversion [ 105 , 107 ]. The VIB device was shown to have an
equal rate of leaks in a head to head comparison with a loop
ileostomy [ 108 ]. The C-seal® (Polyganics Groningen, the
Netherlands) is the newest device and can be attached to the
bowel proximal to the anastomosis with an EEA stapler.
Clinical trials evaluating the C-seal are currently underway.
Compression Anastomosis
A sutureless anastomosis without the associated foreign
body has its theorized advantage. It is not a new concept, as
the idea dates as far back as 1826—long before Murphy’s
button [
109 ]. In the largest study to date, there was a 3.2 %
anastomotic leak rate among 1,180 elective open and laparoscopic colorectal anastomoses [ 109 ]. The authors concluded
that the ColonRing device (novoGI Inc, Netanya, Israel) is
feasible and safe and could be considered as an alternative to
stapled end-end colorectal anastomosis. Further prospective
studies directly comparing the two techniques are needed.
Extraluminal Devices
Methods used to bolster the staple line with bioabsorbable
Seamguard
®
(W.L. Gore & Associates, Flagstaff, AZ) or
meshed AlloDerm® (Lifecell, Bridgewater, NJ) have not
improved the anastomotic strength [
110 , 111 ]. Clinical data
evaluating the use of such tissue-bolstering devices for the
colorectal anastomosis is limited. Staple line reinforcement
has not had the same success in the colorectal anastomosis as
is seen in the gastric bypass or sleeve, where there primary
purpose is reduction in bleeding [ 112 ].
Managing the Failed Anastomosis
Key Concept : Any successful management strategy for anastomotic leak that results in reduced morbidity and mortality
and improves the quality of life emphasizes early diagnosis
and infectious source control through the use of methods that
do not increase the risk of permanent stoma or negatively
impact future bowel function .
Anastomotic Leaks
Anastomotic leaks account for a quarter of all deaths following colorectal surgery [ 45 ]. These mortality rates have
changed very little over the last three decades despite the
continuing improvements in critical care management. The
mortality and morbidity from anastomotic leaks are greatly
infl uenced by the duration of time before a diagnosis is made
and the source of infection controlled [ 45 ]. Unfortunately
many patients will be discharged home before a diagnosis is
made, and others will be treated with more conservative
therapies, both of which delay defi nitive therapy and extend
the duration of infection and sepsis. Aside from morbidity
and mortality, patients with anastomotic leaks can have a signifi cant decrease in their quality of life, which is mainly due
to the high rates of a permanent stoma (up to 72 % in some
studies), especially when end ostomies are performed instead
of proximal diversion [ 113 ].
Clinical Manifestations
Key Concept : Symptoms range widely from nonspecifi c cardiopulmonary and GI complaints to fever and septic shock .
Watching for patients who begin to deviate from the standard
postoperative course will aid in early diagnosis .
The timeframe in which patients present with anastomotic
leaks follows a bimodal distribution, with symptomatic leaks
occurring between 7 and 12 days and asymptomatic leaks
diagnosed months later, usually during the evaluation for
ostomy closure [ 45 , 70 ]. The typical symptoms of an anasto-
motic leak include pulmonary, cardiac, and gastrointestinal
symptoms that unfortunately are not too different from postoperative symptoms in patients without leaks. Indeed since
these symptoms are not specifi c for an anastomotic leak,
patients sometimes are treated by the surgeon for days to
290
N. Smallwood et al.
weeks before the anastomotic leak is fi nally diagnosed [ 114 ].
While cardiac, pulmonary, or gastrointestinal symptoms
(individually) may be fairly nonspecifi c, there is evidence
that the likelihood of an anastomotic leak signifi cantly
increases as a patient develops additional symptoms [
The return of bowel function has always been an important
component in the postoperative management of the colorectal patient. Lack of bowel function beyond 6th postoperative
day is highly predictive of an anastomotic leak, but the presence of bowel function alone is a poor negative predictor
[ 115 ]. Fever and leukocytosis are fairly insensitive during
the initial postoperative stay and are unlikely to reach predictive values while the patient is hospitalized [ 115 ]. Operatively
placed drains can provide clues to the occurrence of a leak,
but surgeons must not be completely dependent on them, as
even patients with benign appearing drainage can have anastomotic leaks. Peritonitis is an obvious clinical sign but may
not be present in diverted patients or those with an extraperitoneal anastomosis. Purulent anal discharge is fairly specifi c,
but can easily go unnoticed by the surgeon or patient.
Sometimes patients may not display any one sign or symptom, but simply fail to follow the standard postoperative
course or meet discharge requirements. These patients which
are “failing to progress” need to be promptly evaluated for an
anastomotic leak.
115 ].
Making a Timely Diagnosis
Key Concept : While several different tests and scoring systems are available to aid in the early diagnosis of leak , the
most important factor is the surgeon ’ s clinical awareness
and acumen .
The importance of a timely diagnosis was shown in the
study by Alves and colleagues [ 45 ] where the mortality
rate increased from 0 to 18 % if the diagnosis was made
after the fi fth postoperative day. Leaks can be diffi cult to
diagnose in the early postoperative period because signs
and symptoms take time to progress. The use of watersoluble contrast enema or computed tomography is not
sensitive enough to be used to screen for leaks. At the
present time, there is ongoing research into other methods
to accurately predict which patients have an anastomotic
leak with the hope that this will prompt an earlier diagnosis. C-reactive protein (CRP) appears to be a very promising marker for anastomotic leaks. Almeida et al. [ 116 ]
showed that serum CRP levels were elevated in all patients
immediately postoperatively on and after the third day in
all patients who had leaks. A total of four studies have all
shown persistently elevated CRP levels after postoperative days 2–4 in colorectal patients diagnosed with anastomotic leaks [
more on postoperative day 3 that fails to decrease in the
following days is a very accurate predictor of anastomotic
leak in colorectal patients [ 118 ]. High levels of sensitivity
116 , 117 ]. A CRP level of 190 mg/L or
(>95 %) and diagnostic accuracy (88.5 %) were seen in
esophageal leaks when using the scoring system, as seen
below, based on the postoperative levels of CRP, WBC,
and albumin [ 119 ].
NUnScore CRP
Another scoring system that used 15 different clinical
and laboratory parameters decreased the delay in diagnosing anastomotic leaks among colorectal patients [ 120 ].
While these studies are promising, the clinical use of these
markers and scoring systems has not been widely established. Currently, the surgeon must rely on a heightened
sense of awareness to signs and symptoms that, when present, should prompt further workup. Computed tomography
with rectal contrast is proven to be better in identifying
anastomotic leaks than water-soluble contrast enema and
also allows for accurate identifi cation of any abscess that
may be amenable to percutaneous drainage [ 74 ]. Some sur-
geons advocate that contrast should be injected down the
distal limb of the ostomy as opposed to through the rectum
to prevent further disunion of the anastomosis [ 121 ]. Some
patients will present with peritonitis and/or and septic
shock and require an urgent laparotomy before any diagnostic studies can be performed. All efforts should be made
to try and evaluate the anastomosis preoperatively, since
intraoperative evaluation can be diffi cult especially when
the leak creates an infl ammatory mass that surrounds the
anastomosis. In cases with no preoperative evaluation, the
anastomosis must be grossly inspected during laparotomy
and with the endoscope. If there is no evidence of any
dehiscence during this inspection, the anastomosis should
then be tested for a leak by insuffl ating air through an endoscope within the anal canal or by injecting Betadine into the
rectum via the endoscope. Not all cases of postoperative
sepsis are due to a leaky anastomosis, and it is important to
correctly identify and control the source of infection to prevent recurrent sepsis. While it is also helpful to identify
these cases preoperatively to avoid negative exploratory
laparotomy, when there is a strong suspicion, the operating
room is almost always the right call (even if no leak is
found).
=+ +11.3894 0.005
WCC albumin
()
0.186 0.174
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×
()
−
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()
Determining the Appropriate Intervention
Key Concept : There are no guidelines , based upon high levels of scientifi c evidence , currently available for the surgeon
to follow . However , adhering to important principles when
faced with this situation will often minimize additional
morbidity and mortality .
18 The Failed Anastomosis
291
Fig. 18.4 Algorithm to treat a symptomatic leak
Anastomotic leaks vary in presentation, as do patients that
suffer from them. Due to this variety seen in patients and the
disease, multiple different types of interventions are possible. This poses a signifi cant challenge to the surgeon when
managing a problem unusual to the practice. The management of leaks has received very little attention in the literature with most studies being retrospective, underpowered,
and suffering from bias. The following guidelines and algorithm, we have provided, are created from an extensive
review of the literature combined with the authors’ own clinical experience. Beyond the literature on colorectal leaks, we
reviewed studies on the management of postoperative sepsis,
damage control laparotomy, infl uence of different management techniques on defi nitive stoma rates, and other less
invasive methods during the acute and chronic period. In
reviewing these studies, in conjunction with our own clinical
experience, we were able to delineate some key fundamental
principles that are necessary in the effective management of
anastomotic leaks which are further illustrated in our management algorithm (Fig.
18.4 ).
Identifi cation and Location
Key Concept : With any peri - anastomotic abscess , you should
rule out a concurrent anastomotic fi stula . One of the most
important fi rst steps is to determine whether a leak is intraperitoneal or completely extraperitoneal .
The fi rst step for any surgeon is to confi rm that there is
indeed a leak and determine its location. An abscess adjacent
to anastomosis is not an anastomotic leak until it is proven to
be so by CT, contrast enema, or in the operating room.
Patients with abscesses, but without evidence of a leak, most
likely can be treated with percutaneous drainage or antibiotics alone. Conversely, if these patients do not respond to
drainage and antibiotics or recur after drain removal, they
should be treated as if they have a leak since both CT and
contrast enema can be falsely negative. Patients with anastomotic leaks located within the peritoneal cavity more often
have diffuse contamination, peritonitis, and present with
sepsis than those patients whose leaks are extraperitoneal.
This is the likely explanation for an increase in mortality
292
N. Smallwood et al.
associated with right-sided colon resections [ 122 ]. Patients
with extraperitoneal leaks usually are already diverted, rarely
benefi t from a laparotomy, and can be treated with less invasive therapies. If a patient does require a laparotomy because
of signifi cant intraperitoneal contamination, it is recommended that the anastomosis be revised or resected only in
the case of severe necrosis and ongoing sepsis. Attempts to
repair or revise a nearly intact anastomosis may be extremely
diffi cult and may cause the patient to have a permanent
ostomy [
115 ].
Symptomatic Versus Asymptomatic
Key Concept : T he presence and degree of symptoms determine your management .
Asymptomatic leaks are usually identifi ed during an evaluation (endoscopy or contrast enema) for ostomy reversal
[ 123 ]. These patients are not acutely at risk of further com-
plications and therefore do not require any immediate intervention. The only therapy is observation. Many asymptomatic
leaks over time will heal on their own. Persistent leaks may
ultimately require some type of intervention. In a low
colorectal anastomosis with ongoing local contamination,
the resulting scar may impact pelvic fl oor and sphincter
function, which unfortunately results in poor quality of life
even though the leak heals [ 124 ]. Surgical judgment is thus
important to avoid this scenario. Symptomatic patients will
always require some form of intervention ranging from percutaneous drainage to exploratory laparotomy depending on
other associated factors.
Postoperative Sepsis
Key Concept : Evidence of sepsis or septic shock will require
the use of more aggressive therapy , as the goal is early infection control and prevention of recurrent sepsis .
Secondary peritonitis occurs in 12–16 % of patients
undergoing elective abdominal operations and carries a high
mortality rate (20–60 %) [ 125 ]. In a patient with postopera-
tive sepsis, the three key components to infection control
consist of draining the infected material, eradicating the
source of infection, and preventing recurrent sepsis [ 126 ].
Early control of the infection improves mortality by minimizing the duration of sepsis and eliminating septic shock
and multiple organ failure [ 127 ]. Diffuse peritonitis requires
laparotomy and washout [ 115 , 121 , 126 ]. Laparoscopy,
washout, and drain placement may be an option in selected
patients treated initially with a laparoscopic resection. The
most debatable issue involves whether a repeat laparotomy
should be predetermined at the time of sepsis control or
based upon signs of an ongoing infection (also referred to as
laparotomy on demand) [ 128 ]. Currently, the best available
evidence favors the use of the laparotomy on demand, where
your goal as a surgeon is to identify and control the source of
infection in a single operation [ 125 ]. The use of planned
repeat laparotomies even though the infectious source has
been controlled provides no additional benefi t and is associated with increased nontherapeutic laparotomies (66 %) and
longer ICU stays [
125 ]. In patients with severe physiological
derangements and hemodynamic instability, an abbreviated
laparotomy is appropriate for initial control of peritonitis.
This will allow for further correction of abnormal physiologic parameters in the intensive care setting while saving
the defi nitive operation once these have been corrected
[
129 ]. The surgeon should also be mindful that in certain
patients, even after a seemingly successful operation, the
infectious source will persist. There are no reliable clinical
indicators for the need for repeat laparotomy other than evidence that the source of infection has not been controlled
based on persistent peritonitis or continued sepsis [
128 ].
This decision should be made within 48 h of the initial operation for secondary peritonitis as patients have been shown to
have a survival benefi t (28 % vs. 77 % mortality rate) over
those patients where the surgeon waited more than 48 h
[
126 ]. Efforts to identify a “hidden source” include intraop-
erative upper and lower endoscopy to insuffl ate air with the
bowel submerged in saline (inner tube test), exploration of
the lesser sac, inspection of every inch of the intestine, and
visualization of the luminal aspect of the anastomosis.
Presence of Diverting Ostomy
Key Concept : Patients with a previously created diverting
ostomy are more likely to be asymptomatic , have an extraperitoneal anastomosis , and less likely to need a laparotomy .
Do not be fooled by the “ contained leak ” in those patients
without a diverting ostomy , as many of these will eventually
need formal laparotomy / laparoscopy .
Patients with symptomatic anastomotic leaks who have a
diverting ostomy are less likely to present clinically with
peritonitis and sepsis (10 % vs. 28 %) or require a laparotomy (8.6 % vs. 25.4 %) [
90 ]. Those who do require a lapa-
rotomy, due to a diffuse leak or severe sepsis, will usually
only need a thorough washout and placement of drains adjacent to the anastomosis [
121 , 130 ].
Symptomatic intraperitoneal leaks in patients that are not
diverted nearly always require a laparotomy [ 121 , 131 ]. In
the subgroup of patients who are not diverted and have contained intraperitoneal leaks, it may be tempting to try percutaneous drainage and antibiotics alone, but evidence shows
that this usually fails and will eventually require a laparotomy [ 131 ].
Extraperitoneal leaks are less likely to present with peritonitis or intra-abdominal sepsis than intraperitoneal anastomosis [ 121 ]. Instead extraperitoneal leaks may present as
urinary symptoms, rectal drainage, and rectovaginal fi stulas
in addition to localized pain and tenderness [
75 , 121 , 124 ].