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_1370_Библиотеки_им_академика_М_И_Перельмана
.pdf
improved outcomes in colon and rectal surgery
The specific type of fecal diversion, ileostomy versus colostomy,
does not influence anastomotic related outcomes.(25)
MECHANICAL BOWEL PREPARATION
Mechanical bowel preparation before elective resection has been
surgical dogma since Halsted’s description of intestinal anastomosis in 1887. Empiric-based practice relies on mechanical bowel
preparation together with oral antibiotics to reduce the bacterial
load of the bowel and, in theory, to decrease the risks of anastomotic leak and surgical site infection. Bowel preparation, far
from innocuous, is inconvenient and unpleasant for patients and
is associated with potentially harmful metabolic and fluid disturbances. For these reasons, and because the purported benefits of
bowel preparation remain unproven, the utility of mechanical
preparation has been questioned.
A Cochrane review evaluating the efficacy of bowel preparation in its ability to reduce postoperative complications included
1,592 patients from nine randomized, controlled trials stratified
to a colectomy group and a low anterior resection group.(26) The
clinical leak rate in the colectomy group with and without bowel
preparation was 2.9% and 1.6%, respectively (p value not significant). The clinical leak rate in the low anterior resection group
with and without bowel preparation was 9.8% and 7.5%, respectively (p value not significant). When the surgical groups were
combined, the 6.2% clinical leak rate in the prepared group was
significantly higher than the 3.2% rate in the unprepared group
(p = 0.003). Meta-analysis of all other infectious complication
rates, including surgical site infection, demonstrated no protective effect of mechanical bowel preparation.
Despite significant evidence that bowel preparation before
elective colorectal resection does not influence infectious complications (and may actually increase the anastomotic leak rate)
surgical tradition and medico-legal pressure continue to heavily influence the practice of colorectal surgery with respect to
mechanical bowel preparation.
ANASTOMOTIC TECHNIQUE
Stapled techniques for low pelvic anastomosis have been rigorously evaluated since their introduction into the armamentarium
of colorectal surgery. A systematic Cochrane review comparing
the outcomes of straight, end-to-end stapled and handsewn colorectal anastomoses pooled data on 1,233 patients from nine randomized, controlled trials.(27) This comprehensive meta-analysis
found no statistically significant difference with regard to clinical
leaks (stapled 6.3% vs. handsewn 7.1%, p value not significant)
or radiologic anastomotic dehiscence (stapled 7.8% vs. handsewn
7.2%, p value not significant).
A similarly conducted Cochrane review of four randomized,
controlled trials comparing stapled versus handsewn ileocolic
anastomoses during colon cancer resection demonstrated significantly fewer clinical leaks in the stapled group (1%) compared to
the handsewn group (4.2%, p = 0.04).(28) Given the fundamental differences between ileocolic and colorectal anastomoses, it is
not surprising that they each may have unique technical requirements to reduce the risks of complications.
In addition to evaluating the mechanics of forming the anastomosis, the configuration of the anastomosis has been studied
with regard to possible reduction in the risk of leak. Of the most
common stapled colorectal anastomotic configurations (end-toend, side-to-end Baker, colonic “J” pouch) there is no optimal
configuration that consistently confers a risk reduction benefit.
(8, 10, 15, 17, 19, 29) It has also been shown that the size of the
circular stapler does not contribute to the leak rate.(14)
OMENTAL PEDICLE
In an effort to quarantine an anastomosis in the event of a leak and
to mitigate the consequences of a leak, many surgeons utilize an
omental pedicle. To reach a pelvic anastomosis, the omentum is
typically mobilized to survive off the left gastroepiploic artery. The
influence of an omental pedicle on anastomotic outcomes was evaluated in a prospective, randomized study of 705 patients undergoing bowel anastomosis and no statistically significant influence on
the rate or severity of leak was observed.(30) Another smaller, randomized, controlled trial of 126 patients demonstrated a protective
effect of an omental pedicle; though, this study could be criticized
for a rather high leak rate (22%) in the group of patients without
an omentoplasty.(31) Both of these studies reported overall leak
rates including clinical and radiologic leaks.
The discrepancy between these two trials is characteristic of
many of the studies investigating anastomotic complications.
Leaks are low frequency events requiring large, homogenous study
populations for accurate evaluation. No firm evidence-based recommendation can be made with regard to omentoplasty and its
potential effects on colorectal anastomotic outcomes; bringing an
omental pedicle to the pelvis should be done according to the
surgeon’s preference.
RADIATION
Neoadjuvant radiotherapy has been evaluated in terms of potentially increasing the risk of dehiscence of pelvic anastomoses.
The proposed mechanism of increasing the leak rate is that pelvic radiation may interfere with healing of the anastomosis due
to toxicity in the pelvis. Radiation changes to the colon side of
the anastomosis are usually not an issue as the irradiated colon
is resected at the time of the proctectomy to ensure that healthy
colon is used to form the anastomosis.
The Dutch Total Mesorectal Excision (TME) trial randomized
1,414 rectal cancer patients to neoadjuvant short-course radiation therapy followed by low anterior resection versus resection
alone and demonstrated no significant difference between the
two groups with respect to clinical anastomotic leak (neoadjuvant group leak rate 11% versus surgery alone leak rate 12%,
p value not significant). However, these results were difficult to
interpret because patients in the radiotherapy group were more
likely to have a diverting stoma.(19, 22) The Swedish rectal cancer trial randomized 1,168 patients to short-course neoadjuvant
radiation followed by surgery versus surgery alone and also demonstrated no significant difference in leak rates between the two
study arms.(32) A nonrandomized study comparing 150 patients
who received long-course chemoradiation (5,040 cGy) followed
by surgery to 531 patients who underwent surgery alone demonstrated similar results with 4% overall leak rate in each group
(p = 0.86).(10) The notion that neoadjuvant radiotherapy
increases the risk of leak is not supported by the majority of the
postoperative anastomotic complications
literature and may be incorrectly based on the fact that low pelvic
anastomoses in the setting of total mesorectal excision are more
likely to leak.(33, 34)
PELVIC DRAINS
Pelvic drains are placed by some surgeons to prevent colorectal
anastomotic leaks and to diagnose leaks sooner with the hope of
initiating treatment before leaking patients clinically decompensate. The possible mechanism whereby pelvic drains, theoretically, may protect against colorectal anastomotic leak relies on the
characteristics of the extra-peritoneal low pelvis in that the peritoneum is absent. Violation of the presacral space during proctectomy leaves a significant raw surface and without the absorptive
abilities of the peritoneum fluid can collect in the dependent dead
space created by total excision of the mesorectum. Further complicating the matter is the potential for negative pressure in the
low pelvis that promotes the accumulation of fluid that can possibly disrupt the anastomosis. A pelvic drain can, possibly, prevent
accumulation of fluid behind the anastomosis. These theoretical
benefits of pelvic drainage together with results of statistically
under-powered trials may explain why many surgeons continue
to drain pelvic anastomoses.
Routine pelvic drainage has been evaluated in retrospective
fashion as well as with randomized, controlled trials with regard
to a possible influence on the occurrence and diagnosis of colorectal anastomotic leak. For example, the data collected in the
prospective, randomized Dutch TME trial was studied after-thefact in retrospective fashion to determine the utility of pelvic
drainage during low anterior resection.(19) Patients in this trial
were randomly assigned whether or not to receive neoadjuvant
radiation therapy before TME. At the time of operation, placement of pelvic drains was decided at the discretion of the operating surgeon. Multiple regression analysis demonstrated that
pelvic drainage was strongly associated with a lower clinical leak
rate (leaks occurred in 9.6% of patients with drains compared
with 23.5% of patients without drains, p < 0.001). Moreover, the
need for re-operation in leaking patients was significantly more
likely in patients without preexisting pelvic drainage (97% of
leaking patients without drains were re-operated versus 74% of
leaking patients with drains, p = 0.006). Other reviews and randomized trials regarding the use of drains have been published
with contradicting results and conclusions; some attributed an
increase in the leak rate to pelvic drainage.(14, 29, 35, 36) Like
the retrospective study reviewed above, many of these papers may
not have accurately evaluated the utility of drains due to lack of
statistical power or suboptimal methodology.
To better evaluate the utility of pelvic drainage after colorectal anastomosis, a Cochrane review tested the hypothesis that
anastomotic drainage after elective colorectal surgery does not
prevent the development of complications.(37) This exhaustive meta-analysis pooled data on 1,140 patients from six randomized, controlled trials. The clinical anastomotic leak rate
for patients with drains versus without drains was 2% and 1%,
respectively (p value not significant). Stratification of the data
according to the height of the anastomosis also showed no benefit of drainage even for low pelvic anastomoses. In addition,
the re-operation rates between patient groups with and without
drains were comparable. This review does not support the practice of routinely draining colorectal anastomoses.
The practice of routinely draining colorectal anastomoses is
not supported by strong scientific evidence. In addition, there is
no compelling literature supporting the notion that pelvic drains
facilitate earlier diagnosis of a leak.
MISCELLANEOUS
Other factors shown to increase the colorectal anastomotic leak
rate include total mesorectal excision (8, 15, 16), height of the
anastomosis from the anal verge (5, 20, 33), male gender (5, 20),
and prolonged operating time (20). Each of these factors is either
difficult or impossible to influence. Due to the large numbers
of patients required to study anastomotic complications, many
variables may never be studied sufficiently in terms of possibly
contributing to anastomotic leak (Table 7.1).
Total mesorectal excision, as it was originally described, left a
relatively ischemic distal rectum after resection for proximal rectal cancer. Tumor specific mesorectal excision for proximal rectal
cancer has become popular as it preserves the distal mesorectum
without compromising oncologic adequacy and decreases the
risk of leak compared with total mesorectal excision.(10, 15, 33,
38) The height of an anastomosis can influence tension across
the tissues and, together with prolonged operating time, is likely
a surrogate marker for more difficult operations especially in the
narrow, male pelvis. It is also postulated that, in low pelvic anastomoses, the proximate anal sphincter increases the intraluminal
pressure across the anastomosis jeopardizing its integrity.
In terms of the surgical approach, the Clinical Outcomes of
Surgical Therapy (COST) trial and others have not demonstrated
an increased anastomotic failure rate with regard to laparoscopic
versus conventional open colectomy.(39–41) Trials evaluating
laparoscopic versus open rectal cancer resection with colorectal
anastomosis are underway.
CLINICAL PRESENTATION
The clinical manifestations of anastomotic dehiscence vary
depending on the location of the leaking anastomosis, the
severity of the leak and whether or not the leak is contained or
walled-off. For these reasons, while many patients with anastomotic dehiscence present acutely with signs and symptoms of
sepsis and an abdominal catastrophe, a subset of patients have
Table 7.1 Factors with conflicting evidence in the literature that
may or may not impact anastomotic leak rates.
Smoking or alcohol abuse (33, 46, 59)
Obesity (8)
Hospital operative caseload (24)
Surgeon subspecialty training and volume (33, 60, 61)
Diabetes (48)
Cardiovascular disease (48)
Steroid use (46, 48)
Malnutrition (46, 62)
Anemia (48)
Blood transfusions (46)
Intraoperative rectal irrigation
ASA score (33)
Field contamination
improved outcomes in colon and rectal surgery
Table 7.2 The time interval between colorectal anastomosis and
diagnosis of a leak.
Post Op Day
Study N of Diagnosis
Rullier 1998 (8) 32 11 2–41
Carlsen 1998 (16) 11 8 4–15
Alves 2002 (47) 43 8.1 4–25
Mäkelä 2003 (46) 44 8 3–25
Hedrick 2006 (4) 14 9b 3–137
Matthiessen 2007 (17) 27 8b 3–18
Nicksa 2007 (45) 36 10.1 2–50
Jung 2008 (6) 35 5.5b 2–15
a. Mean.
b. Median.
a
Range (days)
a more sub-acute, insidious presentation. This is more typical
of walled-off infections and leaks that have sealed on their own.
Possibly contributing to a sub-acute presentation of a leak is the
use of antibiotics during recovery from colorectal surgery (for
pneumonia, urinary tract infection, etc.) that can mask the signs
and symptoms of an occult leak. While the majority of patients
with colorectal anastomotic leak are diagnosed within a week of
operation, a significant proportion of patients are diagnosed well
beyond this timeframe (Table 7.2). Patients with a more delayed
presentation of a leak have often been released from the hospital
only to be diagnosed upon re-admission.(42)
Patients with feculent peritonitis or diffuse purulent peritonitis
typically become acutely ill, often in dramatic fashion, with classic
signs and symptoms of peritonitis, hemodynamic instability and
rapid progression to multisystem organ dysfunction. Meanwhile,
in a considerable number of patients, recognition of an anastomotic leak may be difficult due to the significant overlap between
the signs and symptoms of a leaking patient and those of a typical patient recovering from major abdominal surgery. Patients
may present with any combination of fever, tachycardia, varying
degrees of abdominal pain and distension, ileus, diarrhea, malaise, failure to thrive, bowel obstruction, and septic shock. Some
patients present with symptoms mimicking cardiac complications
such as respiratory failure and chest pain. Leaking patients may
also fail to clinically progress or recover within a usual timeframe,
have increasing narcotic demands, or have decreased urine output
requiring fluid boluses. The physical exam of a leaking patient may
include focal or diffuse abdominal tenderness, rigidity, guarding,
abdominal distension, and evidence of varying degrees of hemodynamic collapse. Patients may have leukocytosis, typically with a
left shift, leukopenia, metabolic acidosis, or thrombocytopenia.
After any intestinal anastomosis, the surgeon must maintain a
high index of suspicion when evaluating patients with unusual
signs of sepsis or patients who fail to meet the clinical milestones
of normal recovery within a typical timeframe. The potential for
delay in diagnosis is significant; delays may impact patient outcomes and have medicolegal ramifications.
DIAGNOSIS
Patients with generalized peritonitis consistent with a leak require
urgent return to the operating room with concomitant intravenous fluid resuscitation and broad-spectrum antibiotics. In this
setting, the time to re-operation is critical and a diagnostic journey with imaging studies will only delay potentially life-saving
abdominal exploration. Meanwhile, patients with a more subtle
clinical presentation do not mandate immediate exploration and
may benefit from imaging studies to confirm the diagnosis and
direct appropriate management.
Although no single radiologic study is ideal for investigating a
possible leak, computed tomography (CT) and contrast enemas
are the tests of choice in this setting. The advantage of triple contrast CT scanning with intravenous, oral, and rectal contrast is
that it may identify other potential underlying pathologies like
ileus, abscess, hematoma, and bowel obstruction. CT scan findings consistent with anastomotic leak include extravasation of
luminal contrast, perianastomotic fluid, ascites, and varying
amounts of extra-luminal gas. With the exception of contrast
extravasation, many of the CT findings in leaking patients are not
specific and overlap considerably with CT scans of nonleaking
patients in the postoperative setting. The mere presence of free air
in the postoperative period is not specific for a leak and has been
demonstrated by CT in control patients without anastomoses up
to 9 days after operation and even later.(43, 44) Depending on the
clinical circumstances, inconclusive CT findings can be followed
up with a contrast enema study, repeat CT or abdominal exploration to exclude anastomotic leak.
According to some of the literature, CT may be superior to
contrast enema when determining the integrity of an anastomosis.(42) Potential shortcomings of enema studies in this setting
are that the water-soluble contrast can dilute out and compromise resolution of a contrast enema and that clinicians may be
reluctant, in the early postoperative period, to introduce a sufficient column of enema contrast to adequately fill the rectum.
On the other hand, some of the retrospective literature strongly
favors contrast enema over CT in terms of diagnosing a pelvic
anastomotic leak outright as well as after a CT scan fails to demonstrate a leak.(9, 45) Extravasation or pooling of rectal contrast
outside of the bowel lumen during an enema study is pathognomonic of leak (Figures 7.1 and 7.2). Water-soluble contrast must
be used when evaluating for a possible anastomotic dehiscence as
extravasated barium increases the severity of a leak by adding to
the inflammatory response in the abdomen. In reality, the choice
of imaging study in a particular patient is influenced by the clinical presentation, institutional expertise, and available resources.
MANAGEMENT
The management of anastomotic dehiscence in a particular
patient depends on the clinical manifestations of the leak and
the condition of the patient (Figure 7.3). Common manifestations of a leak from a colorectal anastomosis are asymptomatic,
leak without abscess, leak with associated abscess, peritonitis, and
colocutaneous fistula.
Asymptomatic
Early in the experience with circular staplers, routine watersoluble contrast enemas demonstrated that as many as half of
patients with pelvic anastomoses demonstrated a radiologic leak
during the first postoperative week. Often these are short, simple sinus tracts originating from the anastomosis. In otherwise
postoperative anastomotic complications
No abscess
No peritonitis
Antibiotics
Bowel rest
No resolution
or
Patient worsens
Anastomotic Leak
Peritonitis
Colocutaneous
Fistula
Abscess
Laparotomy
Antibiotics
Resuscitation
Address any
collections
Drainage
Antibiotics
Leak resolves
Laparotomy
No further
treatment
Worsens
Fistula
Antibiotics
Bowel rest
Nutrition
No resolution
Resolution
No further
treatment
Figure 7.1 Gastrografin enema demonstrating anastomotic leak (black arrows)
from colorectal anastomosis (anterior-posterior view).
Figure 7.3 Management algorithm for patients with anastomotic leak.
asymptomatic patients with an anastomotic leak discovered incidentally, no intervention is required as the leak is not likely of
clinical consequence and will seal spontaneously.
Leak without abscess
Stable patients with mild symptoms, focal abdominal tenderness,
and radiologic evidence of anastomotic leak without abscess may
be initially treated nonoperatively with bowel rest and intravenous fluids and broad-spectrum antibiotics. These are often
minor leaks that can, potentially, seal spontaneously. The duration of treatment is empiric and is based on the clinical response,
the patient’s condition, and the surgeon’s judgment. An initial
Figure 7.2 Gastrografin enema demonstrating leak with contained abscess (white
arrows) from colorectal anastomosis (lateral view).
treatment period of several days is reasonable after which parenteral nutrition or re-operation often need to be addressed.
Clearly, failure to improve or clinical deterioration requires surgical intervention. It is difficult to predict which patients will successfully recover without re-operation in the setting of a leak; this
treatment pathway requires dedicated attention on the part of the
surgeon with frequent hands-on re-evaluation.
Leak with associated abscess
Stable patients with CT evidence of a contained leak with an
abdominopelvic abscess should, initially, be treated with drainage
and appropriate antibiotic therapy (Figures 7.4 and 7.5). Drainage
improved outcomes in colon and rectal surgery
Figure 7.4 Abdominal CT scan demonstrating a large abdominal abscess (arrows
mark cavity).
is usually performed percutaneously or trans-anally through the
anastomotic defect. There are situations where operative drainage is required due to inaccessibility of an abscess by less invasive
routes, but these are quite uncommon. As before, patients who
fail nonoperative treatment require exploration. A contained leak
can rupture freely into the abdomen; depending on the clinical
circumstances, repeat imaging, or urgent exploration would be
required in this situation.
Peritonitis
Patients with generalized peritonitis consistent with a leak require
urgent exploration with aggressive fluid resuscitation and intravenous antibiotic administration on the way to the operating room.
Typically, these patients decompensate quickly and become unstable
and must be treated in urgent fashion. As reviewed earlier, in these
situations, there is no benefit to pursuing diagnostic studies as the
consequences of delaying operative intervention may be dire.
Colocutaneous fistula
Fistulization to the skin, typically through a drain site or skin
incision, may be a late manifestation of anastomotic leak. Once
a fistula is observed clinically, a CT scan is helpful to evaluate for
any undrained collection which would need to be addressed. In
general, once the local sepsis has been controlled, most anastomotic fistulae will close with bowel rest. Optimizing nutritional
status and attention to wound care are important in these patients.
Specific circumstances that may preclude spontaneous resolution
of a fistula are distal obstruction, associated anastomotic stricture, radiation, and steroid therapy. Patients who fail nonoperative treatment may benefit from operative intervention.
OPERATIVE INTERVENTION
The goals of re-operation for anastomotic leak are to control the
source of sepsis, remove any purulence or contamination and
prevent ongoing leak. While preservation of function is important, it must be emphasized that these are life-saving operations.
Figure 7.5 CT scan of a percutaneous drain in an abscess.
There are a number of options available to the surgeon returning
a patient to the operating room to address a leaking anastomosis
and the particular procedure performed is decided at the time of
exploration based on clinical judgment and the unique presentation of the patient on the table.
As most patients undergoing reoperation for suspected leak
require some form of fecal diversion that may be permanent,
potential sites for stoma formation should be marked preoperatively. In the operating room, it is helpful to have the patient in
either split leg position or in lithotomy stirrups to facilitate access
in case proctoscopy is required. In terms of the surgical approach
to re-operation in the setting of a leak, the quickest approach is
likely conventional laparotomy. Laparoscopic exploration has
potential benefits, especially if the original operation was performed laparoscopically or if the diagnosis of anastomotic leak
is not clear, but a minimal-access approach to anastomotic leak
should only be performed by surgeons with expertise in advanced
laparoscopic techniques. Microbial cultures of the peritoneal
fluid encountered during re-operation for anastomotic leak most
often demonstrate polymicrobial flora and are of questionable
benefit in terms of directing patient management.(23)
Resection of the leaking anastomosis and colostomy creation
Traditionally, the surgical approach for a colorectal anastomotic
leak has been to dismantle the anastomosis, bring out the colon
as an end stoma, close the rectum as a Hartmann pouch, washout
the abdomen, and place drains.(12) This modified Hartmann
procedure is very effective at removing the septic source and
alleviating the abdominal sepsis. A major drawback of this operation is that end colostomy reversal is technically challenging
and carries its own risk of morbidity. It is not surprising that
these end colostomies become permanent in a substantial proportion of patients.(4, 23, 46) Exteriorization of the rectal stump
as a mucus fistula (typically described in staged resections for
fulminant proctocolitis) can be considered in the rare circumstance of a difficult to control rectum.(47)
postoperative anastomotic complications
Leaving the leaking anastomosis in place
An alternative to end stoma creation in many instances consists of
abdominal washout, proximal fecal diversion via loop stoma, and
drainage of the anastomotic leak.(19, 23, 45, 46) The benefits of this
approach are that it effectively controls the septic source and allows
the majority of patients to undergo stoma reversal in the future.(4,
6, 17) The main criticism of leaving a leaking anastomosis in place is
that luminal contents proximal to the anastomosis may provide an
ongoing source of contamination and that the anastomosis may stricture or fistulize.(23) Review of the literature does not substantiate the
concern of ongoing contamination and demonstrates that proximal
diversion is safe and has a high rate of anastomotic salvage.
The use of a colostomy versus ileostomy for diversion does not
impact anastomotic outcomes but meta-analysis of 1,204 patients
demonstrated significantly fewer stoma related complications and
postreversal hernias with loop ileostomy.(25) Some advocate lavage
of the proximal colon to eliminate whatever stool is proximal to the
anastomosis and some surgeons describe suturing closed the anastomotic defect in an effort to contain the leak; the utility of these
maneuvers remains empiric. Deciding whether or not to resect or
preserve a leaking anastomosis depends on the surgeon’s experience,
the size of the anastomotic defect, and the viability of the colon.
Repeat anastomosis after resection of the leaking anastomosis
In certain situations, it may be possible to resect a leaking anastomosis and perform a new anastomosis with or without proximal
diversion. This may be technically possible when dealing with a
leak from an ileocolic anastomosis. Colorectal anastomoses are
unlikely to be amenable to immediate reconstruction given the
limitations of reach, especially in a hostile abdomen.
Exteriorization of the leaking anastomosis
Another surgical option for treating a patient with anastomotic
dehiscence is to exteriorize the leaking anastomosis as a stoma. This
removes the septic source from the abdomen and may be performed
rapidly. The potential problems with this damage control approach
are that the anastomosis rarely can reach out to allow exteriorization and that even if the leaking segment can reach out, it will make
for a very bulky and difficult to manage stoma. In addition, this
form of stoma may be fraught with wound-related complications.
The utility and practicality of this approach are questionable.
these reasons that anastomotic leak is the most dreaded complication of colorectal surgery.
Anastomotic leak also carries significant long-term consequences. The quality of life of patients with permanent fecal diversion after a leak and bowel function after experiencing a leak are
significantly impaired.(49) In comparison with patients who did
not leak, patients who undergo stoma reversal after resolution of a
leak have decreased rectal capacity and compliance and more difficulties evacuating.(7) In addition, in a review of nearly 1,400 surgical patients treated for rectal cancer, patients who leaked were less
likely to receive adjuvant chemotherapy and when they did receive
chemotherapy, it was more likely after a substantial delay.(6)
In a multicenter Scottish study of 2,235 patients who underwent curative resection for colorectal cancer, the 5-year overall
survival rate, excluding mortalities within 30-days of operation,
for patients who leaked compared with patients who did not
leak was 42% and 55%, respectively (p < 0.01) (3). The 5-year
cancer-specific survival rate, also excluding postoperative deaths,
for patients who leaked compared with patients who did not leak
was 50% and 68%, respectively (p < 0.001). The increased risk of
cancer-specific death in patients with an anastomotic leak was
most apparent between 2 and 4 years after surgery. Similarly,
other studies have demonstrated increased local recurrence rates
(5) as well as decreased overall and cancer-specific survival (50)
after anastomotic leak. The etiology of these inferior long-term
outcomes in patients who suffer a leak remains speculative.
ANASTOMOTIC STRICTURE
Colorectal anastomotic stricture may occur in up to 10% of patients
depending on how a stricture is defined.(51, 52) From a clinical
standpoint, stricture may be defined as a symptomatic narrowing
of the anastomosis that obstructs the flow of intestinal contents.
(53) Alternatively, a stricture may be defined by the inability to pass
a particular size of proctoscope through an anastomotic narrowing. The vast majority of anastomotic strictures tend to be short
segment stenoses less than a centimeter in length (Figure 7.6).
SHORT AND LONG-TERM IMPLICATIONS OF LEAK
The short-term consequences of an anastomotic leak requiring
operative intervention are substantial. The 30-day mortality rate
associated with anastomotic leak is typically documented in the
10% to 15% range and has been reported to be as high as 36% (3, 5,
42, 46, 47). Indeed, the most common cause of death after colorectal cancer resection is due to anastomotic leak.(4) In comparison to
patients who recover uneventfully, patients who suffer anastomotic
leak consume significantly more healthcare resources. After reoperation for leak, roughly 50% of patients require intensive care
and a number of patients go on to require additional percutaneous
drainage procedures or operations.(4, 17) Also, the average length
of stay of patients with anastomotic leak is considerably prolonged
compared with patients who recover normally from colorectal
resection.(3, 48) In terms of overall morbidity rates, patients who
experience an anastomotic leak are much more likely to experience
further complications than patients who did not leak.(47) It is for
Figure 7.6 Contrast enema demonstrating colorectal anastomotic stricture.
improved outcomes in colon and rectal surgery
(a) (b)
(c)
Figure 7.7 (A) Colonoscopic view of a strictured colorectal anastomosis. (B) Passage of a through-the-scope balloon dilator. (C) Hydrostatic dilation of the stricture.
(D) The dilated anastomosis.
Factors predisposing to anastomotic stricture include anastomotic leak, postoperative pelvic infection, and proximal diversion.
In addition, two meta-analyses concluded that stapling the colorectal anastomosis increases the risk of stricture formation compared with hand sewing the anastomosis.(27, 54) It is hypothesized
that strictures develop due to an inflammatory response or, possibly, from mucosal gaps within a staple line that heal by secondary
intention. Although ischemia is commonly included as a potential etiology of stricture formation, the pathophysiology remains
speculative. Whether or not a smaller diameter circular stapler
increases the risk of stricture formation is not clear; nonetheless,
the convention remains to use the largest diameter stapler that the
bowel can accommodate. Late anastomotic stricture formation is
associated with recurrent cancer, inflammatory bowel disease, and
radiation injury and must be thoroughly investigated.
(d)
DIAGNOSIS AND TREATMENT
While most strictures are likely incidental findings, certain patients
have symptoms such as mechanical obstruction or impaction at
the level of the stricture, constipation, tenesmus, frequent bowel
movements, or diarrhea. In general, asymptomatic strictures in
patients with intestinal continuity are not clinically relevant and
do not require treatment. Meanwhile, symptomatic patients and
asymptomatic patients undergoing evaluation before reversal of
a diverting stoma who demonstrate stenosis require intervention.
Stoma reversal in the face of a stricture risks anastomotic disruption at the site of the stoma takedown and should be avoided.
The majority of colorectal anastomotic strictures that require
intervention are readily salvaged using endoluminal dilating
techniques.(55) Typically, dilation is postponed until the anastomosis has healed and become more pliable; waiting over 4–6
postoperative anastomotic complications
weeks is prudent. Simple methods used to dilate a low anastomosis include gentle digital rectal exam or sequentially sized dilators
(i.e., bougie, Hegar, etc.).
Strictures out of reach for these modalities or that require controlled dilation under direct observation are usually treated with
commercially available through-the-scope (TTS) hydrostatic balloon dilators that control radial expansion using a pressure gauge
(Figure 7.7). Sequential dilation to a diameter >20 mm is usually
accomplished under conscious sedation with or without empiric
antibiotic coverage and has a low complication rate.(56) Balloon
dilation is successful in the majority of cases although repeat dilations may be required. Injecting triamcinolone, a long-acting
corticosteroid, into the stricture or releasing the stricture using
electrocautery or laser in combination with balloon dilation may
decrease the need for repeat dilations without significantly increasing the complication rate.(57) Larger diameter, over-the-wire balloons may require fewer repeat dilations than TTS devices.(55)
The few patients with short anastomotic strictures who do not
respond to repeated dilation and patients with long, irregular
strictures may be candidates for resection with repeat anastomosis. Depending on the height of the stricture, the anastomosis
can be resected and intestinal continuity may be restored with
either colorectal or coloanal anastomosis. To avoid dissecting out
the distal rectum in a reoperative pelvis consideration could be
given to resecting the anastomosis and reconstructing with rectal
mucosectomy and a pull-through operation.(51, 53)
Alternatives to resection to correct an anastomotic stricture
include a number of creative stricturoplasty techniques using transanal endoscopic microsurgery, conventional staplers, or a special
mechanical anastomotic staple cutting device.(58) Individual cases
of endorectal stenting have been reported in the literature but the
utility and long-term outcomes of stenting in the setting of a benign
stricture remain questionable and require further evaluation.
CONCLUSION
Anastomotic complications are difficult to predict and carry significant risks of morbidity and mortality. Attention to detail while
forming a colorectal anastomosis is paramount to reducing the
risk of complications. Tissue sealants, novel compression anastomosis devices, anastomotic buttressing materials, and alternatives
to conventional fecal diversion may each contribute to reducing
anastomotic complications in the future.
REFERENCES
1. Knight CD, Griffin FD. An improved technique for low ante-
rior resection of the rectum using the EEA stapler. Surgery
1980; 88: 710–4.
2. Heald RJ. A new approach to rectal cancer. Br J Hosp Med
1979; 22: 277–81.
3. McArdle CS, McMillan DC, Hole DJ. Impact of anasto-
motic leakage on long-term survival of patients undergoing
curative resection for colorectal cancer. Br J Surg 2005; 92:
1150–4.
4. Hedrick TL, Sawyer RG, Foley EF et al. Anastomotic leak and
the loop ileostomy: friend or foe? Dis Colon Rectum 2006;
49: 1167–76.
5. Branagan G, Finnis D. Prognosis after anastomotic leakage in
colorectal surgery. Dis Colon Rectum 2005; 48: 1021–6.
6. Jung SH, Yu CS, Choi PW et al. Risk factors and oncologic
impact of anastomotic leakage after rectal cancer surgery. Dis
Colon Rectum 2008; 51: 902–8.
7. Nesbakken A, Nygaard K, Lunde OC. Outcome and late functional results after anastomotic leakage following mesorectal
excision for rectal cancer. Br J Surg 2001; 88: 400–4.
8. Rullier E, Laurent C, Garrelon JL et al. Risk factors for anastomotic leakage after resection of rectal cancer. Br J Surg
1998; 85: 355–8.
9. Bruce J, Krukowski ZH, Al-Khairy G et al. Systematic review
of the definition and measurement of anastomotic leak after
gastrointestinal surgery. Br J Surg 2001; 88: 1157–68.
10. Enker WE, Merchant N, Cohen AM et al. Safety and efficacy
of low anterior resection for rectal cancer: 681 consecutive
cases from a specialty service. Ann Surg 1999; 230: 544–54.
11. Lange MM, Buunen M, van de Velde CJ et al. Level of arterial
ligation in rectal cancer surgery. Dis Colon Rectum 2008; 51:
1139–45.
12. Brennan J, Moynagh M, Brannigan AE et al. Routine mobilization of the splenic flexure is not necessary during anterior resection for rectal cancer. Dis Colon Rectum 2007; 50:
302–7.
13. Beard JD, Nicholson ML, Sayers RD et al. Intra-operative air
testing of colorectal anastomoses: a prospective, randomized
trial. Br J Surg 1990; 77: 1095–7.
14. Vignali A, Fazio VW, Lavery IC et al. Factors associated with
the occurrence of leaks in stapled rectal anastomoses: a review
of 1,014 patients. J Am Coll Surg 1997; 185: 105–13.
15. Law WL, Chu KW. Anterior resection for rectal cancer with
mesorectal excision: a prospective evaluation of 622 patients.
Ann Surg 2004; 240: 260–8.
16. Carlsen E, Schlichting E, Guldvog I et al. Effect of the introduction of total mesorectal excision for the treatment of rectal cancer. Br J Surg 1998; 85: 526–9.
17. Matthiessen P, Hallböök O, Rutegård J et al. Defunctioning
stoma reduces symptomatic anastomotic leakage after low
anterior resection of the rectum for cancer. Ann Surg 2007;
246: 207–14.
18. Hüser N, Michalski CW, Erkan M et al. Systematic review
and meta-analysis of the role of defunctioning stoma in low
rectal cancer surgery. Ann Surg 2008; 248: 52–60.
19. Peeters KC, Tollenaar RA, Marijnen CA et al. Risk factors for
anastomotic failure after total mesorectal excision of rectal
cancer. Br J Surg 2005; 92: 211–6.
20. Marusch F, Koch A, Schmidt U et al. Value of a protective
stoma in low anterior resections for rectal cancer. Dis Colon
Rectum 2002; 45: 1164–71.
21. Karanjia ND, Corder AP, Holdsworth PJ et al. Risk of peritonitis and fatal septicemia and the need to defunction the low
anastomosis, Br J Surg 1991; 78: 196–8.
22. Marijnen CA, Kapiteijn E, van de Velde CJ et al. Acute side
effects and complications after short-term preoperative
radiotherapy combined with total mesorectal excision in primary rectal cancer: report of a multicenter randomized trial.
J Clin Oncol 2002; 20: 817–25.
23. Parc Y, Frileux P, Schmitt G et al. Management of post-operative peritonitis after anterior resection. Dis Colon Rectum
2000; 43: 579–89.
improved outcomes in colon and rectal surgery
24. Marusch F, Koch A, Schmidt U et al. Hospital caseload and
the results achieved in patients with rectal cancer. Br J Surg
2001; 88: 1397–402.
25. Tilney HS, Sains PS, Lovegrove RE et al. Comparison of outcomes following ileostomy versus colostomy for defunctioning colorectal anastomoses. World J Surg 2007; 31: 1141–51.
26. Guenaga K, Atallah AN, Castro AA et al. Mechanical bowel
preparation for elective colorectal surgery. Cochrane
Database Syst Rev 2005, 1: CD001544.
27. Matos DDM, Atallah A, Castro A et al. Stapled versus handsewn methods for colorectal anastomosis surgery. Cochrane
Database Syst Rev 2001, 3: CD003144.
28. Choy PY, Bissett IP, Docherty JG et al. Stapled versus handsewn methods for ileocolic anastomoses. Cochrane Database
Syst Rev 2007, 3: CD004321.
29. Yeh CY, Changchien CR, Wang J et al. Pelvic drainage and
other risk factors for leakage after elective anterior resection
in rectal cancer patients: a prospective study of 978 patients.
Ann Surg 2005; 241: 9–13.
30. Merad F, Hay JM, Fingerhut A et al. Omentoplasty in the prevention of anastomotic leakage after colonic or rectal resection. Ann Surg 1998; 227: 179–86.
31. Agnifili A, Schietroma M, Carloni A et al. The value of omentoplasty in protecting colorectal anastomosis from leakage.
Hepatogastroenterology 2004; 51: 1694–7.
32. Swedish Rectal Cancer Study. Initial report from a Swedish
multicentre study examining the role of preoperative irradiation in the treatment of patients with resectable rectal
carcinoma. Br J Surg 1993; 80: 1333–6.
33. Martel G, Al-Suhaibani Y, Moloo H et al. Neoadjuvant therapy
and anastomotic leak after tumor-specific mesorectal excision
for rectal cancer. Dis Colon Rectum 2008; 51: 1195–201.
34. Buie WD, MacLean AR, Attard JP et al. Neoadjuvant chemoradiation increases the risk of pelvic sepsis after radical excision of rectal cancer. Dis Colon Rectum 2005; 48: 1868–74.
35. Merad F, Hay JM, Fingerhut A et al. Is prophylactic pelvic
drainage useful after elective rectal or anal anastomosis?
Surgery 1999; 125: 529–35.
36. Merad F, Yahchouchi E, Hay JM et al. Prophylactic abdominal drainage after elective colonic resection. Arch Surg 1998;
133: 309–14.
37. Jesus EC, Karliczek A, Matos D et al. Prophylactic anastomotic drainage for colorectal surgery. Cochrane Database
Syst Rev 2004, 2: CD002100.
38. Zaheer S, Pemberton JH, Farouk R et al. Surgical treatment of
adenocarcinoma of the rectum. Ann Surg 1998; 227: 800–11.
39. Nelson H, Sargent DJ, Wieand HS et al. A comparison of laparoscopically assisted and open colectomy for colon cancer.
N Engl J Med 2004; 350: 2050–9.
40. Lacy AM, Garcia-Valdecasas JC, Delgado S et al. Laparoscopyassisted colectomy versus open colectomy for treatment of
non-metastatic colon cancer. Lancet 2002; 359: 2224–9.
41. Schwenk W, Haase O, Neudecker J et al. Short terms benefits
for laparoscopic colorectal resection. Cochrane Database
Syst Rev 2005, 2: CD003145.
42. Hyman N, Manchester TL, Osler T et al. Anastomotic leaks
after intestinal anastomosis: it’s later than you think. Ann
Surg 2007; 245: 254–8.
43. Power N, Atri M, Haddad R et al. CT assessment of anastomotic bowel leak. Clin Rad 2007; 62: 37–42.
44. Feingold DL, Widmann WD, Calhoun SK et al. Persistent
post-laparoscopy pneumoperitoneum: expected or cause for
alarm. Surg Endosc 2003; 17: 296–9.
45. Nicksa GA, Dring RV, Johnson KH et al. Anastomotic leaks:
what is the best diagnostic imaging study? Dis Colon Rectum
2007; 50: 197–203.
46. Mäkelä JT, Kiviniemi H, Laitinen S. Risk factors for anastomotic leakage after left-sided colorectal resection with rectal
anastomosis. Dis Colon Rectum 2003; 46: 653–60.
47. Alves A, Panis Y, Trancart D et al. Factors associated with
clinically significant anastomotic leakage after large bowel
resection: multivariate analysis of 707 patients. World J Surg
2002; 26: 499–502.
48. Pickleman J, Watson W, Cunningham J. The failed gastrointestinal anastomosis. J Am Coll Surg 1999; 188: 473–82.
49. Lim M, Akhtar S, Sasapu K et al. Clinical and subclinical
leaks after low colorectal anastomosis: a clinical and radiologic study. Dis Colon Rectum 2006; 49: 1611–9.
50. Walker KG, Bell SW, Rickard MJ et al. Anastomotic leakage
is predictive of diminished survival after potentially curative
resection for colorectal cancer. Ann Surg 2004; 240: 255–9.
51. Garcea G, Sutton CD, Lloyd TD et al. Management of benign
rectal strictures. Dis Colon Rectum 2003; 46: 1451–60.
52. Bannura GC, Cumsille MA, Barrera AE et al. Predictive factors of stenosis after stapled colorectal anastomosis. World J
Surg 2004; 28: 921–5.
53. Schlegel RD, Dehni N, Parc R et al. Results of reoperations in
colorectal anastomotic strictures. Dis Colon Rectum 2001;
44: 1464–8.
54. MacRae HM, McLeod RS. Handsewn versus stapled anastomoses in colon and rectal surgery. Dis Colon Rectum 1998;
41: 180–9.
55. Giorgio PD, Luca LD, Rivellini G et al. Endoscopic dilation
of benign colorectal anastomotic stricture after low anterior
resection. Gastrointest Endosc 2004; 60: 347–50.
56. Nguyen-Tang T, Huber O, Gervaz P et al. Long-term quality of life after endoscopic dilation of strictured colorectal or
colocolonic anastomoses. Surg Endosc 2008; 22: 1660–6.
57. Lucha PA, Fticsar JE, Francis MJ. The strictured anastomosis:
successful treatment by corticosteroid injectors. Dis Colon
Rectum 2005; 48: 862–5.
58. Shimada S, Matsuda M, Uno K et al. A new device for the
treatment of coloproctostomic stricture after double stapling
anastomoses. Ann Surg 1996; 224: 603–8.
59. Sorensen LT, Jorgensen T, Kirkeby LT et al. Smoking and
alcohol abuse are major risk factors for anastomotic leakage
in colorectal surgery. Br J Surg 1999; 86: 927–31.
60. Borowski DW, Kelly SB, Bradburn DM et al. Impact of surgeon volume and specialization on short-term outcomes in
colorectal cancer surgery. Br J Surg 2007; 94: 880–9.
61. Smith JA, King PM, Lane RH et al. Evidence of the effect of specialization on the management, surgical outcome and survival
from colorectal cancer in Wessex. Br J Surg 2003; 90: 583–92.
62. Golub R, Golub RW, Cantu R et al. A multivariate analysis
of factors contributing to leakage of intestinal anastomoses.
J Am Coll Surg 1997; 184: 364–72.
8
General postoperative complications
Scott R Steele and Clifford L Simmang
Financial Disclosure: No outside financial support or provision
of supplies was solicited or received in connection with this work.
Disclosure and Proprietary Statement: This is an original work
by the above author. The opinions expressed are the author’s and
author’s alone. They do not necessarily reflect the opinion of the
U.S. Government, the U.S. Department of Defense, or Madigan
Army Medical Center.
CHALLENGING CASE
A 72-year-old female is scheduled to undergo a low anterior
resection for T3N0M0 rectal cancer. She has been confined to a
wheelchair for the last month due to a fibular fracture. Her comorbidities include diabetes, hypertension, hyperlipidemia, and
she has a 50 pack-year smoking history. Describe the optimal
management for deep venous thrombosis prophylaxis.
CASE MANAGEMENT
The patient falls into a high risk classification as evidenced by
her older age, recent immobility, smoking history, comorbidities, malignancy, and need for pelvic surgery. In addition to the
mechanical measures (e.g., graduated compression stockings or
intermittent pneumatic compression devices and early ambulation) this patient should receive either subcutaneous unfractionated heparin (typically 5,000 IU two or three times per day) or
low molecular weight heparin (~0.5 IU/kg), with higher doses
reserved for those patients within the most at risk group. The first
dose of unfractionated subcutaneous heparin should be given
before induction, preferably 1–2 hours before incision, as some
evidence indicates that venous thrombotic events occur more
commonly during the time of anesthesia induction. Perioperative
use should continue until the patient is fully ambulatory. This
may require patient education on self-injection to continue after
discharge, for up to 10–14 days.
INTRODUCTION
Despite ever-evolving advancements aimed at improving surgical
outcomes, which have included technological innovations, comprehension of perioperative physiology, and implementation of clinical pathways, postoperative complications continue to account for
significant health care costs. Highlighting this, in a study evaluating
the financial impact on surgical site infections alone, development
of one single preventable surgical site infection was associated with
an increased length of stay of almost 11 days, at a resultant cost of
$27,000 for each patient.(1) In addition, lost work days, delayed
functional recovery, and resultant physical deficits are oftentimes
not as easily quantifiable in monetary amounts, yet create an even
larger impact on both patient and society alike. Thus, emphasis
needs to be placed not only on the identification and treatment of
these complications, but also prevention as a major focus in order
to optimize outcomes. In this chapter we will review the current
status of a variety of perioperative parameters surrounding complications encountered with colon and rectal surgery as well as
explore the most recent measures employed for prevention. More
detailed treatment options are found in specific chapters elsewhere
within this text.
PAIN
Although it may seem intuitive that adequate control of postoperative pain is a mandatory and rather easy standard to achieve,
in practice this oftentimes remains a far more difficult objective
to attain. In part, this may be secondary to the lack of having an
accurate way to predict those patients that will have difficulty with
postoperative pain control. In addition, we frequently use primitive measures to quantify pain, relying heavily on devices such as
visual analogue scales and verbal pain scales commonly employed
in the recovery phase, which, due to language and cultural barriers, often do not have adequate correlation amongst patients. This
is especially evident when trying to accurately detect and record
changes in pain level over time, evaluate which pain dimension
the patient is being asked to report (i.e., intensity versus relief), or
to which interval does the pain level correspond (i.e., current level
versus average over a time period).(2) Despite these difficulties,
adequate pain control remains such an important component to
the overall care of the postoperative patient, it is often referred to
as the fifth vital sign. Optimal control of pain continues to be pursued through a multifactorial and multifaceted approach.
Emphasis in recent years has been toward adequate preoperative
and thus preemptive pain control. Medications such as ketorolac,
COX-2 inhibitors, and local anesthesia before the incision have all
been used in attempt to lessen postoperative pain, as well as decrease
reliance on more traditional methods such as narcotics. Sim and
colleagues in a prospective randomized blinded study of 40 patients
undergoing elective colorectal surgery found the perioperative use
of COX-2 inhibitors, which included a single dose 1 hour before
surgery, was associated with a significant decrease in both postoperative narcotic use as well as shorter recovery of bowel function
and earlier discharge.(3) Lack of widespread use of these agents has,
in part, been centered on surgeon concerns regarding the potential
for increased bleeding felt to be associated with use of these medications. Yet this appears to be unfounded. As narcotics are plagued by
side effects such as respiratory depression, constipation, and ileus,
which hinder gastrointestinal recovery following colorectal surgery, methods to decrease their usage seem beneficial in this patient
population. This is not to say that patients following both colorectal
and anal surgery do not require narcotics; However, other classes
of medications may improve pain control, while minimizing the
dependency on them. Other Nonsteroidal Antiinflammatory Drugs
(NSAIDS) have also been evaluated in the postoperative period as
independent pain-controlling agents, yet appear to work better in
Соседние файлы в папке Библиотека им академика М.И. Перельмана