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 / @xirurgi_2025 / @xirurgi_2025 - 279 - файл
.pdf
SMALL BOWEL 167
https://t.me/med1917
LONG-TERM MANAGEMENT
As soon as the patient is stabilized and sepsis is controlled, then longterm management begins, usually starting within 2 days of diagnosis
and lasting months to years. This chronic management consists of
fluid and electrolyte repletion, nutritional optimization, pharmacologic control of effluent volume, and wound care, all of which are
performed in parallel, using multidisciplinary expertise (Fig. 2). With
this treatment, approximately 30% to 35% of EC fistulas will heal
spontaneously within 5 to 6 weeks of diagnosis. Therefore, long-term
management aims to increase the likelihood of spontaneous closure
while also optimizing the patient for possible operative intervention.
Fluid and Electrolyte Repletion
Patients with EC fistulas, particularly high-output EC fistulas, can
develop severe dehydration and electrolyte derangements. Quantifying fistula output and resuscitating adequately are crucial for the acute
FIG. 1 CT scan shows enterocutaneous fistula with no drainable abscesses.
precludes safely running the bowel and identifying the leak. Performing an extensive lysis of adhesions in this state is fraught with danger,
as healthy loops of bowel can be injured, leading to unnecessary
bowel resections or missed enterotomies. If the source of the leak is
identified, bowel resection can be performed; however, an anastomosis should not be created, as the risk of a recurrent leak is substantial.
Similarly, primary repairs tend to not be durable solutions. Surgeons
should have a low threshold to perform fecal diversions and/or leave
drains to create a controlled fistula. It is important to remember that
these are damage-control operations to address intraabdominal sepsis, not to definitively repair the enteric leak.
Once a patient has been stabilized and abscesses have been
drained, antibiotics can be stopped in 4 to 7 days, pending clinical
improvement. Longer courses of antibiotics are unnecessary for
controlled EC fistulas and could lead to multiresistant organisms,
which could make further antimicrobial management difficult. If a
patient develops recurrent fevers, leukocytosis, or abdominal pain,
clinicians should have a low threshold to reimage, as new abscesses
could develop even after initial source control has been obtained.
and long-term management of these patients. Many patients with
high-output EC fistulas utilize total parenteral nutrition (TPN) for
not only nutrition but also volume resuscitation. These patients often
have long-term central access (such as peripherally inserted central
catheters) for TPN, which enables them to also administer extra
intravenous fluid infusions at home if needed based on fistula output.
The most common electrolyte abnormalities are hyponatremia,
hypokalemia, and hypomagnesemia. Hyponatremia often normalizes with fluid resuscitation, and potassium and magnesium should
be aggressively repleted. Patients with duodenal fistulas can develop
metabolic acidosis requiring sodium bicarbonate replacements. After
starting parenteral nutrition or resuming enteral nutrition, patients
must be closely monitored for refeeding syndrome, with frequent
serum phosphorus checks and phosphorus repletion.
Nutritional Optimization
Patients with EC fistulas can develop profound malnutrition, as they
can lose up to 500 g of protein daily. Markers of nutritional status
such as prealbumin, albumin, and transferrin should be monitored
closely. Patients with low-output fistulas require 20 kcal/kg per day
of carbohydrates and fat and 1 g/kg per day of protein, which can
increase to 30 kcal/kg per day and 1.5 to 2.5 g/kg per day for patients
with high-output fistulas.
Fluid and
electrolyte
repletion
Sepsis control and
drainage of abscesses
Nutritional
optimization
• Enteral
• Parenteral
• Fistuloclysis
Spontaneous closure
(approximately 33%)
FIG. 2 Algorithm for the management of enterocutaneous fistulas.
Diagnosis of enterocutaneous
fistula
Use of
pharmacologic
agents to
decrease
fistula output
Determine if low-, moderate-, or
high-output fistula
Wound
care
Operative intervention
(wait at least 6 months)
Characterize
anatomy
fistula
168 MANAGEMENT OF ENTEROCUTANEOUS FISTULAS
https://t.me/med1917
Enteral feeding is preferred to parenteral nutrition because it promotes mucosal integrity, maintains intestinal function, and supports
immune function. However, oral intake can often increase fistula
output substantially, which can be a problem for wound care in some
patients. TPN is usually needed as a bridge to enteral feeding or for
longer-term nutrition in patients who cannot tolerate oral intake.
A common approach for patients with newly diagnosed fistulas is
to attempt a few days of bowel rest, with or without TPN depending
on the patient’s nutritional status, to see if the fistula spontaneously
closes or if the output decreases. If the output persists, then an oral
diet is gradually introduced. If the fistula output increases significantly and there are concerns for malabsorption, then TPN is started.
Pharmacologic measures, as discussed later, should be used to slow
fistula output. As long as fistula output is controlled and wound care
is manageable, most patients are able to continue an oral diet, with
or without TPN for nutritional support. This holds true even for
high-output fistulas, assuming that ostomy appliances are well seated
and capture the output, and assuming that patients can provide
themselves with additional IV fluids as needed.
Fistuloclysis
Fistuloclysis has become a popular method of enteral feeding distal
to the EC fistula. With this technique, the distal limb of the EC
fistula is identified using a fistulogram, which can be performed by
interventional radiology or in the operating room using fluoroscopy
(Fig. 3). The interventional radiologist or surgeon cannulates the
distal limb with a catheter, which can then be used to instill tube
feeds. Ideally, the surgeon tunnels the catheter under the skin, which
enables securing of the catheter more firmly in place and facilitates
easier wound care. For patients with high-volume liquid output,
their effluent can be collected, strained, and then refed into the distal
feeding tube. This method should only be used in patients who have
fistulas that are not expected to close spontaneously, as cannulating
the distal limb of the fistula will prevent it from closing.
Fistuloclysis enables maintenance of mucosal integrity and promotes intestinal adaptation and lengthening, which is beneficial for
patients who will likely require operative intervention. It also enables
patients to wean off parenteral nutrition. Furthermore, fistuloclysis
has been shown to activate an “ileal brake,” in which refeeding of
succus leads to decreases in gastric acid secretion, pancreatic enzyme
secretion, and peristalsis, thereby decreasing EC fistula output.
The careful balance between oral intake, distal tube feeds, succus refeeding, and parenteral nutrition requires collaboration with
nutritionists who follow these patients closely as inpatients and
outpatients and whose expertise is key to the long-term optimization
of these patients.
Pharmacologic Management of Fistula Output
Another key component to the long-term management of EC fistulas is controlling effluent volume. First-line pharmacologic agents
include opiate receptor agonists such as loperamide, diphenoxylate/
atropine, codeine, and distilled tincture of opium, which act on the
circular and longitudinal intestinal muscles to decrease peristalsis.
These medications can be titrated up as needed to slow fistula output.
Proton pump inhibitors and histamine-2 receptor antagonists are
also part of the first-line treatment of high-output EC fistulas, as they
lower the acidity of fistula output, while also decreasing volume due
to their antisecretory effects.
Other agents can be added to the first-line pharmacologic therapies. Amitriptyline is a tricyclic antidepressant that causes constipation via anticholinergic pathways. Clonidine, an alpha 2-adrenergic
agonist, increases mucosal absorption of fluids and electrolytes.
Bulking agents such as psyllium or banana flakes can also be helpful
to thicken enteric contents. Cholestyramine, a bile acid sequestrant,
is useful in decreasing the output of more proximal EC fistulas,
such as those originating from the duodenum or proximal jejunum.
Octreotide, a somatostatin analog, has been recommended for use in
high-output fistulas. It acts by reducing gastric acid and pancreatic
enzyme secretions, as well as enhancing fluid and electrolyte absorption by prolonging intestinal transit time. Numerous studies have
demonstrated that octreotide does not increase the likelihood of
spontaneous fistula closure; however, it does decrease fistula output
and the time it takes for fistulas to close.
With these pharmacologic agents, even high-output EC fistulas
can be slowed to the point that many patients resume oral intake
while keeping fistula output within a goal of <1 to 1.5 L per day.
FIG. 3 Example of a fistulogram, in which a catheter is inserted into the
fistula, enteric contrast is injected, and the bowel is opacified.
Wound Care
The skin surrounding EC fistulas often becomes excoriated due to
spillage of acidic succus, similar to ileostomies that are difficult to
pouch (Fig. 4A). Patients with EC fistulas benefit from the expertise
of wound and ostomy nurses who develop plans for isolating the
fistulas and protecting the surrounding skin. These complex wounds
usually require a combination of stoma paste and powders, barrier
rings, and hydrocolloid dressings, as well as specialty ostomy appliances that can be cut to fit the fistulas (Fig. 4B and 4C). Pouches need
to accommodate fistuloclysis catheters that directly enter the wound,
which is why catheters that tunnel under the skin and come out away
from the wound are preferred. EA fistulas sometimes require sump
drains to collect the effluent and divert it away from the surrounding
skin.
Vacuum dressings can be used to promote granulation of the
surrounding tissues and protect those tissues from effluent. However, they must be used with caution. If vacuum dressings are placed
SMALL BOWEL 169
https://t.me/med1917
ABC
FIG. 4 A patient with multiple enterocutaneous (EC) and enteroatmospheric (EA) fistulas along a prior midline incision. (A) Note the skin excoriation
around the fistulas. There is an ileostomy in the right lower quadrant that was distal to the fistulas. (B) The wound care plan included protecting the surrounding skin with stoma paste and barrier rings molded to the shape of the wound, thus also isolating the main fistulas. (C) Stoma appliances were then
placed over the fistulas and the ileostomy to catch the effluent. Note that the main stoma appliance is further secured by adhesive dressings.
on granulation tissue directly over bowel or on a skin graft directly
over bowel, the suction force could promote the development of new
fistulas. Nevertheless, numerous small studies have demonstrated
that, when used appropriately, vacuum dressings can promote wound
healing and may even accelerate spontaneous closure.
Wound care plans often change over time as the wounds ideally
heal and contract. Wound and ostomy nurses work very closely with
patients and their families, teaching them tips and tricks to care for
their wounds during the months- to years-long process.
Define the Fistula Anatomy
Next, it is critical to characterize the anatomy of the EC fistula,
utilizing imaging studies such as CT scans with oral contrast, upper
gastrointestinal swallow studies with small bowel follow through,
contrast enemas, and fistulograms in which the proximal and distal
limbs of the fistula are cannulated and injected with oral contrast
under fluoroscopy (see Fig. 3). The goal of these studies is to delineate the location of the fistula, how much bowel is proximal and
distal to the fistula, and assess if there are multiple fistulas. They can
also determine if fistuloclysis will be possible. Furthermore, these
studies can assess for distal obstructions, which would make spontaneous closure unlikely, and can help with operative planning.
SPONTANEOUS CLOSURE
Approximately 30% to 35% of EC fistulas will close within 2 months
of diagnosis without operative intervention (Box 2). Fistulas with
tracts longer than 2 cm, defect sizes of <1 cm
2
, and decreasing output
are more likely to heal spontaneously. Distal obstructions, ongoing
sepsis or abscess, and malnutrition are all predictors of requiring operative intervention. EC fistulas caused by Crohn’s disease,
malignancy, radiation, or a foreign body are also less likely to close
spontaneously.
OPERATIVE INTERVENTION
EC fistulas that have not spontaneously closed within 2 months will
likely require operative management. Most surgeons recommend
waiting at least 6 months after the diagnosis of the fistula before
BOX 2 Characteristics Predictive of Spontaneous
Closure of Enterocutaneous Fistulas
Increased Likelihood of Spontaneous Closure
Postoperative etiology
Fistula tract longer than 2 cm
Fistula defect <1 cm
Healthy surrounding bowel
Good nutritional status
Low fistula output
Decreased Likelihood of Spontaneous Closure
Non-postoperative etiology (inflammatory bowel disease,
cancer, radiation)
Distal obstruction
Presence of a foreign body
Continued sepsis or abscess present
Epithelialized fistula tract
Steroid use
Malnourished
High fistula output
considering an operation. Over this period of time, intraabdominal
adhesions soften and become more filmy, thus making the operation
easier and less prone to causing enterotomies. The “pinch test” for EA
fistulas, in which tissue or skin graft overlying bowel is pinched to see
if the underlying bowel separates easily, can also be used to determine readiness for surgery. Surgeons should wait until the patient is
nutritionally optimized, sepsis is controlled, and the patient is at or
close to their baseline functional status.
In the operating room, surgeons should prepare for a difficult,
lengthy procedure. Ideally, the case should start in the morning, and,
for complex fistulas, no other operations should be planned for the
same day. Anesthesiologists should be prepared for high insensible
losses and should resuscitate accordingly, using a urinary catheter for
2
170 MANAGEMENT OF ENTEROCUTANEOUS FISTULAS
AB
https://t.me/med1917
FIG. 5 The same patient from Figure 4 was taken to the operating room for an enterocutaneous (EC) fistula takedown. (A) Opening the wound revealed
multiple loops of small bowel densely adhered to the prior incision, which were the sources of the numerous EC and enteroatmospheric (EA) fistulas. (B)
At the conclusion of the case, a unilateral anterior component separation was used to close the fascia primarily. The loop ileostomy was converted to an
end ileostomy.
accurate recording of urine output. Epidural catheters or transversus
abdominis blocks should be considered for postoperative pain management. The incision should be made away from prior incisions,
if possible, usually subxiphoid, and dissection should be started
away from the EC fistula. An extensive lysis of adhesions with sharp
dissection should be performed and the bowel should be fully mobilized, such that the exact location of the fistula, the amount of bowel
involved in the fistula, and the presence of any other enterotomies
can be identified. It is not uncommon for multiple loops of bowel
to be involved in the inflammatory mass surrounding EC fistulas
(Fig. 5A). Any foreign material such as previous mesh should be
removed. The surgeon should look for any distal obstruction so that
it can be fully addressed. At this point, the amount of bowel to resect
can be determined with the goal of preserving as much small bowel
as possible to prevent future short-gut syndrome. Fistula defects
should not be repaired primarily, as it will likely lead to recurrent
leaks. The amount of remaining bowel should be documented.
Most of these operations require closure of a large abdominal
wall defect. Due to the contamination of the wound, many surgeons
would not recommend placing synthetic mesh to aid in abdominal
closure. Instead, component separations should be used to close the
fascia if simple primary closure is not possible (Fig. 5B). Biologic
mesh can be placed in an underlay fashion if needed. Involving general surgeons or plastic surgeons who specialize in abdominal wall
reconstruction can be beneficial, particularly for large and complex
abdominal wall defects.
Surgeons and patients must be prepared for the possibility of a
frozen abdomen. If it becomes clear that the EC fistula itself cannot
be resected safely, other options include creating a diverting stoma, if
one is not already present, or placing a venting gastrostomy tube and/
or a distal feeding jejunostomy tube.
Though the morbidity and mortality rates of EC fistula takedowns have been improving over time, patients must still be counseled preoperatively on the risks of the procedure and the long
postoperative recovery. Approximately 16% to 36% of EC fistulas
will recur after surgery, though some recent studies quote operative success rates as high as 92%. Mortality has decreased from
approximately 40% in the 1970s to approximately 20% currently,
with some studies citing mortality rates as low as 2%. Nevertheless,
30-day morbidity rates have been reported to be nearly 50% based
on analysis of the American College of Surgeons National Surgical
Quality Improvement dataset. Although significant improvements
have been made over the years, EC fistula takedowns remain complex, morbid operations, and patient expectations should be set
preoperatively.
The postoperative recovery period typically lasts for several
months. Parenteral nutrition can be weaned off as enteral nutrition
improves. Many patients benefit from postoperative physical therapy,
and some require stays in rehabilitation facilities.
SUMMARY
EC fistulas are complex, debilitating conditions that require multidisciplinary, long-term management. By using the algorithm of sepsis
control followed by simultaneous fluid and electrolyte management,
nutritional optimization, decreasing the volume of effluent, and
wound care, approximately one-third of EC fistulas will close on
their own. For patients who require operative intervention, waiting
at least 6 months to allow for preoperative optimization and softening of adhesions has led to decreasing mortality rates and increasing
rates of operative success.
SMALL BOWEL 171
https://t.me/med1917
S u g g e S t e d R e a d i n g S
Bhama AR. Evaluation and management of enterocutaneous fistula. Dis
Colon Rectum. 2019;62(8):906–910.
Christensen MA, Gaitanidis A, Parks J, et al. Thirty-day outcomes in the
operative management of intestinal-cutaneous fistulas: A NSQIP analysis.
Am J Surg. 2021;221(5):1050–1055.
Evenson AR, Fischer JE. Current management of enterocutaneous fistula.
J Gastrointest Surg. 2006;10(3):455–464.
Management of
Radiation-Induced
Injury to the Small and
Large Bowel
Sophia Y. Chen, MD, MPH, and Chady Atallah, MD
INTRODUCTION
Radiation therapy plays an important role in the multimodal management of anorectal, gynecologic, and urogenital pelvic malignancies. Approximately 70% of cancer patients undergo radiation
therapy for the treatment of these malignancies to prolong their
disease-free survival and reduce local recurrence. Although radiation delivery is directed at the target tissue for maximum benefit,
radiation fields required to treat these malignancies may nevertheless include normal small intestine, colon, and/or rectum, leading
to potential injury of otherwise healthy tissue. Radiation-induced
injury to the bowel therefore remains a critical issue requiring careful
management considerations and preventative strategies.
PATHOPHYSIOLOGY AND
HISTOPATHOLOGY
Radiation therapy is most commonly delivered via external beam
radiation therapy (EBRT), which uses a linear accelerator to produce
ionizing radiation. EBRT can directly or indirectly damage DNA within
malignant and normal cells through its interaction with water and the
release of free radicals. Depending on the extent of DNA damage, EBRT
can result in mitotic inhibition or cellular apoptosis. Brachytherapy is
another method of radiation delivery and involves the placement of a
radiation source within the body, often in the form of pellets or beads.
The pathophysiology of radiation damage to the bowel has been
described in the literature via the “target cell” theory, in which acute
effects of radiation-induced injury target cells of the bowel epithelium, whereas chronic effects of radiation-induced injury target
cells with slower turnover, such as endothelial cells and fibroblasts.
Rapidly dividing cells like those in the gastrointestinal (GI) tract are
most susceptible to radiation injury; as such, radiation affects the
cells of the mucosa first, followed by the submucosa, muscularis, and
serosa. Chronic radiation injury to the bowel is often associated with
ischemic injury. Reaction of fibroblasts to cytokines, growth factors,
and chemokines leads to fibrosis. Cellular death leads to intestinal
atrophy and subsequent malabsorption and stricture formation.
Radiation can also result in vascular damage, leading to dilatation of
small blood vessels presenting as telangiectasias. Furthermore, arteriolar constriction can result in bowel ischemia and necrosis.
Ortiz LA, Zhang B, McCarthy MW, etal. Treatment of enterocutaneous fistu-
las, then and now. Nutr Clin Pract. 2017;32(4):508–515.
Teubner A, Morrison K, Ravishankar HR, etal. Fistuloclysis can successfully
replace parenteral feeding in the nutritional support of patients with
enterocutaneous fistula. Br J Surg. 2004;91(5):625–631.
Histopathologically, acute radiation injury to the bowel is often
characterized by extensive mucosal inflammation, crypt atrophy/
abscesses, nuclear atypia with bizarre mitoses, and eosinophilic submucosal infiltration. Chronic radiation injury to the bowel is often
characterized by obliterative enteritis (irregularly shaped endothelial
cells, fibroblasts, myofibroblasts, and foamy cells within arteries),
small-vessel vasculopathy (dilated, thickened, hyalinized blood vessels), ulceration, fibrous induration, and superimposed episodes of
ischemic changes (Fig. 1).
RISK FACTORS
Risk factors associated with radiation-induced bowel injury include
both patient factors and radiation treatment-related factors. Patient
comorbidities associated with an increased risk for radiation-induced
injury include smoking, diabetes mellitus, hypertension, vascular and
collagen disorders, atherosclerosis, coronary artery disease, inflammatory bowel disease, and prior intestinal surgery. Chemotherapy
such as fluoropyrimidines, taxanes, platinum agents, mitomycin C,
gemcitabine, methotrexate, actinomycin D, topotecan, and doxorubicin can act as radiosensitizers and potentiate the effects of radiation.
Low body mass index (BMI) has also been associated with increased
risk for radiation injury due to higher rate of radiation toxicity.
Radiation treatment-related factors associated with increased risk
for radiation-induced injury include higher radiation dose, longer
length of bowel irradiated, fewer dose fractionation, and larger radiation field size.
FIG. 1 Histopathology (magnification ×20) showing submucosal
fibrosis with atypical fibroblasts, endothelial cells, and increased
inflammatory cell infiltrate. (From Theis VS, Sripadam R, Ramani V, Lal S.
Chronic radiation enteritis. Clin Oncol. 2010; 22[1]:70–83.)
172 MANAGEMENT OF RADIATION-INDUCED INJURY TO THE SMALL AND LARGE BOWEL
https://t.me/med1917
RADIATION THERAPY TOXICITY
GRADING SYSTEMS
Although various radiation toxicity grading systems exist in the
literature, the Radiation Therapy Oncology Group (RTOC) and
the European Organization for Research and Treatment of Cancer (EORTC) grading system is one of the most commonly used
(Table 1). The RTOC/EORTC grading system differentiates acute
radiation morbidity (day 1 through 90) from chronic radiation
morbidity (after day 90) on a scale from 0 to 5 based on presenting
symptoms. Although these grading systems provide a standardized
assessment based on patient symptoms, they do not include endoscopic and histopathologic information. Other available grading
systems include the Late Effects Normal Tissue (LENT) system; the
Subjective, Objective, Management, and Analytic (SOMA) grading
system for chronic radiation injury; and the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE).
CLINICAL FEATURES
Acute radiation-induced bowel injury can occur from the time of
radiation treatment up to 6 months after treatment completion.
Because acute radiation damage leads to mucosal inflammation
and damaged mucosal surface, diarrhea is one of the most common
symptoms. Injury to the mucosal barrier also increases the risk for
bacterial translocation and subsequent bacteremia and sepsis. Other
symptoms of acute radiation-induced bowel injury include nausea,
bloating, cramping, abdominal pain, and GI dysmotility. Acute radiation colitis and proctitis can present with additional symptoms of
bleeding, mucus discharge, urgency, and tenesmus.
Chronic radiation-induced bowel injury can continue from
the acute phase or present after a latent period. Chronic radiation
injury symptoms typically present 8 to 12 months after treatment
completion; however, symptoms have been reported up to 30 years
after a latent period. Like acute radiation-induced injury, diarrhea is
one of the most common symptoms. Chronic radiation proctitis can
also commonly present with rectal bleeding due to telangiectasias.
Patients with chronic radiation-induced bowel injury can also have
ulcerations from ischemia, abscesses, and fistula formation. Chronic
ischemic changes can lead to stricture formation and subsequent
bowel obstruction. Full thickness necrosis of the bowel can result in
fistulae or free perforation.
DIAGNOSIS
Acute radiation-induced injury to the small intestine, colon, and
rectum is generally diagnosed based on the patient’s presenting
symptoms and history. Chronic radiation-induced bowel injury is
diagnosed not only by symptoms but also may require additional
imaging such as a CT scan or MR enterography to evaluate the anatomy and assess for strictures, fistulae, or bowel wall thickness abnormalities. Patients with suspicion for radiation colitis or proctitis may
occasionally undergo barium and water-soluble contrast enemas,
which can reveal shortening, narrowing, lack of distensibility, and
absent haustral/mucosal folds of the bowel. Fistulae may need to be
further evaluated with MRI, fistulograms, cystograms, and pelvic
examinations.
Definitive diagnosis can be made endoscopically with biopsies
demonstrating histologic features pertaining to radiation injury,
as described previously. Upper endoscopy may be considered for
suspected radiation injury to the duodenum; however, lower endoscopy may not be effective in reaching more distal areas of radiation
enteritis. Capsule endoscopy should only be considered if intestinal
strictures have been excluded. Lower endoscopy via colonoscopy or
sigmoidoscopy is beneficial in diagnosing radiation colitis and proctitis. These are characterized by neovascularization with fragile vessels on lower endoscopy (Fig. 2). Other features of radiation-induced
bowel injury include pallor and friability. Rectal biopsies should be
performed judiciously, as they have been associated with increased
risk of rectal fistula formation.
MANAGEMENT STRATEGIES
Medical Management
Between 50% and 75% of patients with acute radiation-induced
bowel injury present with symptoms. Fortunately, these symptoms
are often self-limited and can be managed medically. Diarrhea can
be managed with antidiarrheal medications such as loperamide and
fiber supplements, and with dietary modifications (e.g., lactose-free
diet, low-fat diet, low-residue diet, or elemental diet). Patients with
severe diarrhea, dehydration, and nutritional deficits may need to
be admitted to the hospital for intravenous fluids and/or parenteral
nutrition. If first-line antidiarrheals are ineffective, octreotide may
be given. Nausea can be managed with antiemetics. Anticholinergics,
TABLE 1 RTOG/EORTC Radiation Toxicity Grading System
Grade 1 2 3 4 5
Acute radiation
morbidity
(Days 1–90)
Late radiation
morbidity
(Days >90)
RTOG/EORTC, Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer
• Increased frequency or
change in bowel habits
•
Rectal discomfort
• No medication
• Mild diarrhea and
cramping
•
Bowel movement
≤5 times daily
• Slight rectal discharge
or bleeding
• Diarrhea requiring
parasympatholytic
drugs
•
Mucus discharge not
requiring sanitary
pads
•
Rectal or abdomi-
nal pain requiring
analgesics
Moderate diarrhea and
•
cramping
•
Bowel movement
>5 times daily
•
Excessive rectal
mucus or intermittent
bleeding
•
Diarrhea requiring
parenteral support
•
Severe mucus or blood
discharge requiring
sanitary pads
•
Abdominal distension
Obstruction or bleed-
•
ing requiring surgery
• Acute/subacute
obstruction, fistula, or
perforation
•
GI bleed requiring
transfusion
•
Abdominal pain or
tenesmus requiring
tube decompression
or bowel diversion
• Necrosis, perforation,
or fistula
•
N/A
Death
•
SMALL BOWEL 173
https://t.me/med1917
FIG. 2 Endoscopic appearance of radiation proctitis showing tel-
angiectasias. (From Hogan NM, Kerin MJ, Joyce MR. Gastrointestinal compli-
cations of pelvic radiotherapy: medical and surgical management strategies. Curr
Probl Surg. 2013; 50[9]:395–407.)
antispasmodics, bile acid–binding agents like cholestyramine, and
antisecretory agents can also be considered.
Butyrate enemas have been shown to provide some benefit for
the management of acute radiation proctitis due to the provision of
short chain fatty acids as nutrient for colonocytes; however, they have
had mixed results for the management of chronic radiation proctitis. Recent Multinational Association of Supportive Care in Cancer
FIG. 3 Argon plasma coagulation of rectal ulcer.
(From Araujo IK, Muñoz-Guglielmetti D, Mollà M. Radiation-induced damage in the
lower gastrointestinal tract: Clinical presentation, diagnostic tests and treatment
options. Best Pract Res Clin Gastroenterol. 2020; 48–49:101707.)
(MASCC) guidelines for patients with chronic proctitis in patients
with rectal bleeding recommend the use of sucralfate enemas, given
sucralfate’s ability to evoke a protective barrier and promote epithelial healing. Other enemas such as mesalamine (5-ASA) enemas,
short-chain fatty acid enemas, and steroid enemas have had mixed
findings and require further investigation.
neodymium-doped yttrium aluminum garnet (Nd:YAG) laser therapy, radiofrequency ablation, and cryotherapy are alternative endoscopic treatments that can be performed to treat bleeding, they are
now rarely performed due to the effectiveness of APC.
Formalin therapy has been found to be an effective form of
topical treatment for bleeding from chronic radiation proctitis by
chemically cauterizing telangiectasias and ulcers. Formalin (4%–10%
concentration) can be delivered via irrigation with aliquots of 20 to
50 mL for a total volume of 400 to 500 mL or via direct application of
formalin-soaked gauze onto mucosa via rigid proctoscopy. Washout
with formaldehyde is typically recommended after application of formalin. Although formalin therapy is effective, multiple application
sessions may be required. It is important to avoid direct contact of
formalin to the anoderm because this may cause irritation and pain.
Potential complications of formalin therapy include anal/pelvic pain,
stricture, rectal wall necrosis, and fistula formation.
Other medical treatments that can be considered for radiation-induced bowel injury include antioxidants (vitamins E and C),
probiotics, and hyperbaric oxygen to facilitate angiogenesis. A few
studies have suggested that a 4-week course of oral metronidazole
may be associated with decreased bleeding, ulceration, and diarrhea
in radiation proctitis.
Surgical Management
More than 30% of patients with chronic radiation-induced bowel
injury will require surgical intervention. Surgery is indicated for
patients whose symptoms are unable to be managed medically or
endoscopically, as well as for patients with complications including
perforations, fistulae, strictures, obstruction, intractable pain, and
incontinence. Surgery for patients with radiation-induced bowel
injury is fraught with technical challenges and a high potential for
complications. Morbidity and mortality rates after surgical intervention can range from 30% to 65% and 6.7% to 25%, respectively. The
irradiated abdomen can contribute to a hostile operative environment with friable tissue, extensive adhesions, and high risk for bowel
injury and poor healing. Careful preoperative planning based on
individual patient factors in a multidisciplinary/specialized setting
and a structured approach to operative intervention is therefore
critical to achieving safe and effective surgery. It is important to
also appreciate the risk of recurrence or de novo malignancy in the
Endoscopic Management
Endoscopic therapy can play an important role in the treatment of
chronic radiation-induced bowel injury. Argon plasma coagulation
(APC) is currently the treatment of choice for bleeding, before considering the use of formalin therapy. APC has been found to stop
bleeding in 80% to 90% of cases and is a safe approach because it
coagulates at a superficial depth (Fig. 3). Some studies also demonstrate improvement of bowel function after APC. However, like
formalin therapy, patients may require multiple APC treatments. It is
important when performing APC to avoid the dentate line because
contact may result in anorectal pain. Potential complications for
APC include anorectal pain and abdominal cramping. Although
irradiated bowel segment during preoperative planning. Once the
decision to proceed with surgery is made, effort must be made to
correct modifiable factors and optimize the patient preoperatively.
This may entail correcting electrolyte derangements and providing
enteral nutrition for severely malnourished patients. Surgical options
for radiation-induced bowel injury include limited bowel resection,
bypass/exclusion procedures, stricturoplasty, and fecal diversion.
The choice of surgical incision for patients with chronic radiation
injury should be carefully considered because patients who undergo
radiation therapy have impaired wound healing. Some surgeons may
prefer a low transverse incision inferior to the umbilicus to avoid the
irradiated area. Others may prefer a lower midline incision to allow
for adequate exposure and in case further interventions are needed
174 MANAGEMENT OF RADIATION-INDUCED INJURY TO THE SMALL AND LARGE BOWEL
https://t.me/med1917
in the future. A Pfannenstiel incision may be considered for thin
female patients. The role of minimally invasive surgery for radiation-induced bowel injury is controversial. A diagnostic laparoscopy
with abdominal entry via open Hasson technique would determine
whether a minimally invasive approach is feasible, with dense
adhesions or pelvic fibrosis serving as contraindications. Once the
abdomen is entered and the severity of disease is assessed, dissection
should begin proximally, where radiation-induced damage is less
severe, and move distally. Gentle handling and extreme care of tissue
via sharp dissection using Metzenbaum scissors is recommended to
prevent bowel injury. Blunt dissection can be associated with a high
risk of enterotomy and should be avoided.
For patients with extensive, dense adhesions, limited adhesiolysis
should be performed only in the area of interest and only if the bowel
is resectable because there is increased risk for fistula formation and
bowel injury. Patients with pelvic adhesions generally have small
bowel segments adherent in the pelvis; bowel adherent to the sacrum
may be extracted from the pelvis with careful dissection, although it
is important to avoid damage to the presacral veins and to be able to
deal with any ensuing hemorrhage that could occur. Enterotomies
would commit the surgeon to extracting the bowel from the pelvis.
If a bowel segment were fibrosed to the sacrum, it may be safer to
leave this segment attached while applying diathermy to the mucosal
surface. Hydrodissection via saline injection into dense interloop
adhesions can prevent serosal injuries.
Limited bowel resection of the involved segment is generally preferred over other surgical alternatives such as bypass/exclusion because
it is associated with decreased rates of reoperation and increased survival. During bowel resection, careful consideration is necessary when
selecting the two pieces of bowel to be used for bowel anastomosis.
Grossly irradiated bowel can appear pale, mottled, yellowish/gray, or
telangiectatic with features of vascular insufficiency (Fig. 4). However, irradiated bowel can also appear indistinguishable from normal
bowel. Anastomotic leak rates between two pieces of irradiated bowel
can be as high as 50%; as such, anastomosis between nonirradiated
bowel is recommended when possible. If an anastomosis is necessary,
the cecum and terminal ileum should be avoided as these segments
often experience severe radiation injury. Hand-sewn anastomosis is
favored when possible to avoid staple-line ischemia. Because radiation
can lead to friable, thickened, and foreshortened mesentery, it is also
FIG. 4 Intraoperative comparison of radiation-damaged small
bowel (left) with healthy bowel (right). (From Hogan NM, Kerin MJ, Joyce
MR. Gastrointestinal complications of pelvic radiotherapy: medical and surgical
management strategies. Curr Probl Surg. 2013; 50[9]:395–407.)
recommended to over-sew the mesentery with an interlocking heavy
#1 chromic suture between clamps rather than simply ligating the
mesentery with vessel sealers or a clamp, cut, tie technique.
Although bowel resection is preferred, bypass/exclusion can be
considered in patients with extensive adhesions and/or pelvic fixation in which resection is not possible. Bypass is associated with a
decreased risk of bowel or mesenteric injury and lower anastomotic
leak rate compared with bowel resection; however, it increases the
risk of blind loop syndrome and fistula formation from the affected
segment left behind, which can contribute to further complications.
In select cases, stricturoplasty may be considered as an intestine-preserving alternative to more extensive bowel resection or bypass
techniques to reduce risk of short gut syndrome and avoid total
parenteral nutrition (TPN) dependence.
The management of postradiation enteric and pelvic fistulae are
similar to those employed for other types of fistulae, including sepsis management, nutritional optimization, and fistula maturation/
output optimization. Higher pelvic fistulae (rectovaginal, rectourethral) can be treated with proctectomy and anastomosis of colon
to distal nonradiated rectum or anus. Hand-sewn coloanal anastomosis should only be considered in younger patients with intact
sensation, function, and control. Interposition of well-vascularized
tissue (omentum or rectus pedicle flap) between the affected organ
and anastomosis is highly recommended. Lower pelvic fistulae can
be managed similarly or via a perineal (Kraske) or transsphincteric
(York-Mason) approach. Flap reconstruction (gracilis, omentum,
rectus, bulbocavernosus, or Martius) should be considered for better
healing. In severe circumstances, it may be necessary to perform a
pelvic exenteration.
Fecal diversion has been found to be effective in the management
of pain, tenesmus, incontinence, obstruction, and sepsis and for
patients who are not optimal surgical candidates. Because dissection
can be difficult in an irradiated pelvis with greater risk for bowel
injury, loop ileostomies and transverse/descending colostomies may
be safer to perform than sigmoid colostomies.
PREVENTION
The risk of radiation-induced bowel injury can be minimized with
careful attention to radiotherapy planning and radiation delivery
methods. Recent advances in radiation therapy techniques have
sought to maximize radiation dose to the tumor while minimizing
radiation to adjacent normal tissues. One method for doing so is
3D conformal radiation therapy (3DCRT), which utilizes 3D planning via CT and computer technology to plan and deliver radiation
treatment that matches the shape of the tumor, thereby allowing for
higher dose of radiation delivery to the tumor with less effect on normal tissue. Intensity-modulated radiation therapy (IMRT) is another
technology in which varying intensities of radiation are delivered in a
planned field with clear identification of malignant vs. normal tissue.
Brachytherapy is another method that can be used alone or in conjunction with EBRT to reduce normal tissue injury. Proton therapy
is also a new technology being used by certain tertiary centers as an
option to minimize the amount of radiation to structures and organs
surrounding the target anatomy.
Other strategies to reduce radiation injury include prone positioning, protective belly boards, and ensuring that the bladder is
full during radiation delivery. Amifostine, a prodrug that metabolizes into a thiol metabolite that functions as a free radical scavenger, has demonstrated benefit in some studies to prevent symptoms
of acute radiation proctitis, though these findings have largely
been reported in small, single center studies. Operative maneuvers
including the use of omental slings and tissue expanders to fill
the pelvis can be considered if radiation were to be administered
postoperatively.
SMALL BOWEL 175
https://t.me/med1917
S u g g e S t e d R e a d i n g S
Araujo IK, Muñoz-Guglielmetti D, Mollà M. Radiation-induced damage in
the lower gastrointestinal tract: Clinical presentation, diagnostic tests and
treatment options. Best Pract Res Clin Gastroenterol. 2020;48–49:101707.
Ashburn JH, Kalady MF. Radiation-Induced Problems in Colorectal Surgery.
Clin Colon Rectal Surg. 2016;29(2):85–91.
Hogan NM, Kerin MJ, Joyce MR. Gastrointestinal complications of pelvic
radiotherapy: medical and surgical management strategies. Curr Probl
Surg. 2013;50(9):395–407.
Kennedy GD, Heise CP. Radiation colitis and proctitis. Clin Colon Rectal Surg.
2007;20(1):64–72.
Mendenhall WM, McKibben BT, Hoppe BS, Nichols RC, Henderson RH,
Mendenhall NP. Management of radiation proctitis. Am J Clin Oncol.
2014;37(5):517–523.
Raîche I, Moloo H. Radiation, Microscopic, Ischemic Colitis. In: Steele S,
Hull T, Read T, Saclarides T, Senagore A, Whitlow C, (eds). The ASCRS
Textbook of Colon and Rectal Surgery. Cham: Springer; 2016:951–969.
Sarin A, Safar B. Management of radiation proctitis. Gastroenterol Clin North
Am. 2013;42(4):913–925.
Shadad AK, Sullivan FJ, Martin JD, Egan LJ. Gastrointestinal radiation injury:
prevention and treatment. World J Gastroenterol. 2013;19(2):199–208.
Tabaja L, Sidani SM. Management of Radiation Proctitis. Dig Dis Sci.
2018;63(9):2180–2188.
Theis VS, Sripadam R, Ramani V, Lal S. Chronic radiation enteritis. Clin
Oncol. 2010;22(1):70–83.
https://t.me/med1917
Соседние файлы в папке @xirurgi_2025