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Revision
Bariatric Surgery is Surgical Treatment for Failed or Otherwise Complicated
Weight-Loss Operations
There are several reasons why patients may seek out revisional
bariatric surgery. For many patients, a single operation to treat
obesity is sufficient to produce durable, long-term weight loss
without complications. For some patients, however, a weight-loss
procedure may yield less-than-optimal results, either through inadequate
weight-loss, inadequate resolution of co-morbidities, or by medical
complications specifically related to their weight-loss surgery.
You may have heard the adage, "if the only tool one has is
a hammer, every problem ends up looking like a nail". In the
practice of revision bariatric surgery, one needs to make every
tool in the toolbox available, and be open to the concept of using
new tools as they are developed, as well as understanding the diversity
of problems and being able to invent new tools as each situation
demands.
Risk and Results
The decision to undergo revisional bariatric surgery is one not
to be taken lightly, and, as in any other operation, that decision
hinges on weighing the risk against the benefit. Revision bariatric
procedures are inherently higher risk than first-time bariatric
procedures. They are typically longer procedures, often (but not
always) through open incisions, with greater blood loss, and a higher
incidence of leak and infection. The higher leak rate is thought
to be a result of microscopic changes in blood flow to the stomach,
induced by the original surgery. Whereas the results of a revision
bariatric procedure are fairly predictable when treating medical
complications of weight-loss surgery, the results of revision procedures
to further weight-loss are less so. It has been observed that the
weight-loss results of revision surgeries do not seem to be as good
as if the operation was performed as a first-time procedure. This
phenomenon is metabolic in nature; the body appears to undergo metabolic
adaptation to the first bariatric operation making subsequent weight-loss
more difficult, and patients who are particularly metabolically
stubborn are more likely to fail a first-time weight-loss procedure
in the first place. Given these factors, revisional bariatric procedures
are best approached on a highly individualized basis, tailoring
weight-loss surgery to the patient's unique and specific needs.
Revision
Bariatric Surgery: Reasons
- Weight Regain/Inadequate Weight Loss
- Inadequate Resolution of Co-morbidities
- Medical Complications
Revision
Bariatric Surgery: Specific Revision Considerations
- LapBand
- Roux-N-Y Gastric Bypass
- Vertical Banded Gastroplasty (VBG) and Other "Stomach Stapling" Procedures
- Mini-Gastric Bypass
- Vertical/Sleeve Gastrectomy
- Duodenal Switch
- Metabolic Bone Disease
- Vitamin Deficiencies
Weight Regain/Inadequate Weight Loss
This is the most common reason for patients to consider revisional
bariatric surgery. A certain operation may be expected to yield
a certain amount of average weight-loss for the "average"
patient, but not all patients are "average". A particular
patient may not be suited for adapting to the lifestyle required
for success for a particular operation; a particular operation may
not be suited for the patient's particular metabolism; a particular
operation may not maintain its original anatomy over time. All these
are reasons why a bariatric operation may fail.
The first consideration is determining whether it is the patient
or the operation that has failed. Sometimes patients lack insight
into how to make their particular operation work optimally. Getting
"back on track" with proper aftercare and support may
be all such patients need. Many times, however, a patient's body
may be particularly resistant to losing weight after a period of
weight regain, which may limit their ability to lose - for a second
time - the weight that they had previously lost.
In many instances it is the operation that has failed the patient,
whether it be for "mechanical" or for "metabolic"
reasons.
Mechanical reasons for failure encompass those instances where
the anatomy of the original operation has changed over time. A pouch
may stretch out and enlarge; the outlet of a gastric pouch may dilate
to a larger diameter; a gastro-gastric fistula may form between
a gastric pouch and the bypassed stomach; the absorptive capacity
of the intestine may increase beyond that expected; a band may have
slowly slipped, resulting in less restriction. In these cases, re-construction
of the original surgical anatomy may restore the original conditions
that allowed the patient to lose weight in the first place. Re-trimming
of a dilated gastric-bypass pouch is one such approach, or a re-trimming
of a stretched-out vertical sleeve gastrectomy. Placing a band around
a dilated gastric-bypass outlet often makes a suitable remedy for
a dilated outlet. Re-stapling broken down staple-lines of gastroplasty
procedures has been advocated in the past, but are probably best
addressed by conversion to a different bariatric operation, given
the high failure rate of gastroplasty operations long-term.
And then there are those cases of metabolic failure, where the
operation fails to meet the metabolic needs of the patient.
Success after surgery is often more than a simple matter of watching
what one eats; there is a metabolic component to obesity as well,
which explains why some people are able to eat massive amounts of
food and remain lean, while others are stuck in the rubric of "once
on the lips, forever on the hips". "Metabolic failure"
is a case of the operation failing the patient. Whereas remedial
operations for "mechanical failure" aim to restore the
previous anatomy, operations to address "metabolic failure"
involve a paradigm shift directed at converting the patient to a
more metabolically-active operation. One example of this paradigm-shift
thinking would be revising a patient with a stretched out and dysfunctional
Gastric Bypass pouch to a Duodenal Switch, as opposed to re-trimming
the pouch to restore it to its original size.
For more information on these procedures, see the "Specific
Revision Considerations" portion of this section.
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Inadequate Resolution of Co-morbidities
Inadequate resolution of co-morbidities is another reason for consideration
for revision/conversion surgery. These considerations are usually
related to the causes of metabolic failure, as inadequate resolution
of co-morbidities usually parallels inadequate weight-loss, and
co-morbidities are intimately linked to metabolism. These cases
parallel the approach to metabolic failure cases, and often involve
a conversion to a more metabolically active procedure.
For more information on these procedures, see the "Specific
Revision Considerations" portion of this section.
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Medical Complications
Some patients have medical complications as a result of their weight-loss
operations that require revision surgery. Some of these revision
procedures parallel the "mechanical" vs. "metabolic"
paradigm outlined in the previous section, whereas others require
reversal of the original procedure while preserving weight loss.
Conditions potentially requiring revision include ulcer, stricture,
severe dumping, malnutrition, over-malabsorption, metabolic bone
disease, iron deficiency/anemia, vitamin deficiency, vitamin-D deficiency,
and thiamine (vitamin B-1) deficiency.
For more information on these procedures, see the "Specific
Revision Considerations" portion of this section.
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Revision
Bariatric Surgery: Specific Revision Considerations
LapBand
Patients may require revisional bariatric surgery after LapBand
surgery for a variety of reasons. Band slippage may be a slow chronic
condition, or an acute surgical emergency. In either event, the
band fails to function as it should. Remedial options potentially
include band removal, repositioning, or replacement, depending on
the circumstances. Removal of the band, of course, leaves the patient
with the possibility of weight regain, potentially requiring additional
surgery.
Band erosion is another potential complication of LapBand surgery.
This is a condition where the band wears a hole into the stomach,
rendering the band relatively ineffective. Patients may notice a
single episode of vomiting blood as the initial sign of band erosion.
The most common presenting symptom is an infection around the port
site. This occurs as a result of saliva leaking through the hole
in the stomach, tracking along the band tubing, and subsequently
infecting the tissues under the skin around the port. Treatment
consists of removal of the band. This leaves the patient without
a weight-loss operation, making weight regain likely. My recommendation
in these instances is to convert the patient to a Vertical/Sleeve
Gastrectomy based procedure, such as Vertical/Sleeve Gastrectomy,
Duodenal Switch, or VERGITO. These procedures can be performed with
a minimal amount of cutting through the area of erosion, which is
a weakened part of the stomach made more prone to leak as a result
of the erosion.
LapBand failure is another reason for seeking revisional bariatric
surgery. LapBand is essentially a restrictive procedure, and not
all patients are metabolically tuned to be able to lose the necessary
amount of weight with LapBand. Other patients are simply unable
to maintain the appropriate eating behaviors that success with LapBand
demands, which can result in counterproductive, maladaptive eating
patterns, leading to weight regain and failure. Conversion to any
other weight-loss procedure is possible, but it is these cases where
a paradigm-shift in thinking away from restrictive procedures to
more metabolically active procedures is most likely to yield the
best results. There is a fair body of evidence that a well-managed
LapBand is nearly as good as a Gastric-Bypass over time, as both
rely on the maintenance of restrictive eating through similar size
pouches long-term. Conversion to a Gastric-Bypass procedure may
therefore yield only marginal benefit, while putting the patient
at significant risk of leak.
For those patients who still want nothing more than a restrictive
procedure, conversion to Vertical/Sleeve Gastrectomy makes an excellent
option. Their results will still be limited by the metabolic limitations
of their bodies and of the surgery, but there are several ways in
which Vertical/Sleeve Gastrectomy may yield better results than
LapBand over time. For those patients willing to undergo more involved
procedures, proceeding to Duodenal Switch or VERGITO, which build
from the platform of Vertical/Sleeve Gastrectomy, make excellent
choices. These procedures invoke metabolic mechanisms to maintain
weight loss, without relying merely on restriction, and take the
patient one step beyond where they were with the original LapBand
surgery.
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Roux-N-Y Gastric Bypass
Patients with Gastric Bypass are candidates for revision surgery
for two general reasons: failure (weight gain/inadequate weight
loss) and medical complications. Sometimes medical complications
of Gastric Bypass may result in failure as well. The causes of failure
may be either mechanical or metabolic, with consideration of the
patient's eating behaviors as well. Adhering to the principle of
"making the best of what you've got", the first step in
evaluating a post-Gastric Bypass patient with weight-loss failure
is to take a careful inventory of their food intake. Keeping a detailed
food diary is the best way to begin to make such an assessment,
and patients are often surprised to see what their actual daily
intake is. We may have a general idea of what our food intake consists
of - what we believe we are eating - only to look back on an accurate
food diary and be confronted with the truth. If patients are off
track with what they should be doing from a dietary standpoint,
getting them back on track is the next step. What happens next is
variable: some patients are able to get back on track and back to
where they were; some patients get back on track with their eating
without success at weight-loss; some patients are never able to
resume appropriate eating behaviors, which does not necessarily
mean that the patient is "non-compliant". There may be
a mechanical reason for patients having to resort to maladaptive
eating behaviors, such as what occurs when a patient with an anastomotic
stricture falls into the "soft-calorie syndrome" out of
necessity, because soft foods are the only foods that can be tolerated
without vomiting. We must also realize what it means to be "compliant"
with a Gastric-Bypass. What constitutes "appropriate"
eating for a Gastric Bypass patient would be a most unusual pattern
of eating for the rest of humanity; some people just aren't cut
out for that sort of thing, even with the help of a small gastric
pouch, and not necessarily due to any character flaw, either.
Reasons for mechanical failure of Gastric-Bypass include gastro-gastric
fistula, pouch dilation, and anastomotic dilation. Gastro-gastric
fistula is where the stomach pouch grows back and re-connects to
the bypassed stomach. This can occur as a consequence of a pouch
leak, where the resulting local inflammation from the leak disrupts
the staple line of the bypassed stomach where it lies next to the
pouch. More often, though, gastro-gastric fistula formation is a
result of a less acute, slower process. Regardless the cause, gastro-gastric
fistula allows food to pass from the pouch to the bypassed stomach,
effectively partially reversing the Gastric-Bypass. Revision surgery
for this condition may consist of closure of the fistula, restoring
the original surgical Gastric-Bypass anatomy. Conversion to a Vertical/Sleeve
Gastrectomy based procedure is an option as well, especially if
there are reasons other than mechanical failure to explain the patient's
weight gain.
Pouch dilation is a condition where the stomach pouch stretches
out and enlarges; anastomotic dilation is where the connection between
the stomach pouch and the intestine stretches out. Both conditions
result in allowing the patient to eat more than what would be required
to remain successful. Re-trimming the pouch to make it small again
is one approach to treating pouch dilation. Surgical banding and
endoscopic fixation are two approaches to treat an enlarged anastomotic
connection. These approaches to pouch and anastomotic dilation are
both directed at restoring the anatomy of the Gastric-Bypass procedure
back to what it was prior to stretching out. Another approach is
to make a paradigm shift and convert to a more metabolically active
procedure such as Duodenal Switch. Other Vertical/Sleeve Gastrectomy
based procedures are options as well, especially if the patient's
Gastric-Bypass is complicated by nutrient malabsorptive issues,
such as osteoporosis and anemia.
Conversion from Gastric-Bypass to Duodenal Switch is the most definitive
revision procedure for inadequate weight-loss or weight gain after
Gastric-Bypass. This approach addresses the issues of metabolic
failure and maladaptive eating as causes of failure. This conversion
may be done laparoscopically in many cases. A potential concern
with this procedure is that of proper stomach function after surgery.
The bypassed stomach is now brought back into use, and some patients
may have had the nerves to the bypassed stomach cut during their
original Gastric-Bypass procedure. This is rarely a problem, as
the nerves seem to grow back as the bypassed stomach "wakes
up" and resumes working again. Sometimes it may not be safe
to re-connect the gastric pouch to the bypassed stomach due to excessive
scar tissue. If the patient has acceptable protein tolerance and
satisfactory calcium metabolism, conversion to a Scopinaro-type
Bilio-Pancreatic Diversion makes a very satisfactory option.
Medical issues complicating Gastric-Bypass include marginal ulcer,
stricture, and severe dumping syndrome. These conditions may often
be treated conservatively, but when conservative treatment fails,
revision surgery is indicated. Treatment for ulcer or stricture
may involve resection of the ulcerated/strictured connection between
the pouch and the intestine. Another approach is to convert to a
Vertical/Sleeve Gastrectomy-based procedure, as stricture and marginal
ulcer are conditions that arise as a result of the intrinsic physiology
of Gastric-Bypass. This approach is favored for cases of severe
dumping as well, as it is the inherent nature of the Gastric-Bypass
itself that results in the condition. Rarely, reversal of Gastric-Bypass
may be necessary to treat cases of malnutrition, including issues
of vitamin and mineral malabsorption. Reversals for nutrient malabsorption
may be accompanied by revision to a non-malabsorptive weight-loss
procedure, allowing patients to stave off any weight re-gain that
may otherwise result from the reversal of their malabsorption.
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Vertical Banded Gastroplasty (VBG) and Other
"Stomach Stapling" Procedures
Most patients with VBG and other "stomach stapling" procedures
seeking revision surgery do so for two reasons: weight re-gain and
maladaptive eating. Although some of these cases can be successfully
treated by re-stapling and re-banding, most cases are best treated
by conversion to a more definitive procedure. Given the stubbornness
of many patients' bodies at losing weight after failure of a weight-loss
procedure, conversion to a more metabolically active procedure brings
patients out of the difficulty of trying to induce further weight-loss
by relying on restriction alone. Revision to Duodenal Switch is
one such example, and can often be performed laparoscopically. For
patients with previous VBG, removal of the band during revision
to Duodenal Switch is not always necessary. Given the variety of
stomach-stapling procedures, and the various ways in which their
anatomy may change over time, these cases are highly individualized
in their surgical approach.
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Mini-Gastric Bypass
The issues with revision of Mini-Gastric Bypass procedures are
the same as for Roux-n-y Gastric-Bypass. Bile reflux is a potential
condition unique to this type of Gastric-Bypass. Although this is
an uncommon condition (and a concern more theoretical than actual),
revision to Roux-n-y Gastric-Bypass is sufficient to treat this,
and is a relatively straightforward conversion, and is done without
having to disrupt the original connection between stomach pouch
and intestine.
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Vertical/Sleeve Gastrectomy
While highly effective for many, some patients fail to lose adequate
weight with Vertical/Sleeve Gastrectomy, and may seek revision surgery
in order to induce further weight loss. Sometimes failure is a result
of stretching of the stomach, and re-sleeving the stomach may suffice
as a revision procedure. For others, adding metabolic and malabsorptive
components onto the Vertical/Sleeve Gastrectomy "platform",
such as Duodenal Switch and Ileal Transposition, may be indicated.
Whereas most revision operations carry a higher risk than first-time
bariatric procedures, revision of Vertical/Sleeve Gastrectomy to
Duodenal Switch is less risky than performing Duodenal Switch as
an all-at-once, first-time operation. Vertical/Sleeve Gastrectomy
is one component of a Duodenal Switch procedure, so when converting
to a Duodenal Switch procedure, a good portion of the operation
has already been done, resulting in a lesser surgery than performing
Duodenal Switch in its entirety. In addition to weight loss, stretching of the stomach may result in other difficulties as well. The stretching of the stomach tube may not be uniform along its entire length, resulting in parts of the stomach tube being more stretched-out than others. This may result in an “Hourglass Stomach”, where the stomach has a large upstream portion separated from an enlarged downstream portion by an area of relative narrowing. This does not necessarily result in increased eating, but may result in uncomfortable, disordered eating. Patients usually experience reflux symptoms and a generalized difficulty eating. Depending on the constellation of the patient’s symptoms and meal volumes, surgical revision may take a couple of forms, but all result in a more direct passage of food from the upstream to downstream stomach.
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Duodenal Switch
Anywhere from 2-5% of Duodenal Switch patients may be candidates
for revision surgery. As our understanding of how best to balance
the seemingly contradictory demands of weight-loss and malnutrition
improves, the likelihood of a Duodenal Switch patient requiring
revision surgery can be minimized, but not eliminated entirely.
Inadequate weight-loss, excessive weight-loss, and malabsorptive/nutritional
deficiencies comprise the most typical reasons for revision of Duodenal
Switch.
Excessive weight-loss and malabsorptive/nutritional deficiencies
usually go hand-in-hand, and are some of the most straight-forward
issues to surgically correct in Duodenal Switch patients. As in
many endeavors, timing is everything. The overall malabsorptive
effect of Duodenal Switch changes over time, with the intestine
becoming more efficient at absorbing protein calories and nutrients.
It is important to not revise a patient with malabsorptive complications
too early after Duodenal Switch. An earnest attempt at conservative
therapy should be instituted prior to revision, to allow time for
the natural increase of absorptive capacity of the intestine to
manifest itself. If revision is performed too early, patients risk
excessive weight re-gain later on, after the intestine has fully
adapted. Treatment for malabsorptive complications after Duodenal
Switch generally involves adding intestinal length, a process known
as elongation. Specific elongations of the common limb using the
biliopancreatic limb are possible to obtain specific effects. A
fairly common elongation procedure involves an elongation of both
the alimentary limb and the common limb, which allows more surface
area for protein absorption as well as starch and fat absorption.
Increasing the capacity to absorb fat also increases the ability
to absorb fat-soluble vitamins such as vitamin-D. Revision procedures
to treat protein malnutrition and excessive weight-loss therefore
have the added effect of increasing the capacity for fat-soluble
vitamin absorption. The simplest procedure to increase both alimentary
and common limb length involves a single small intestine connection,
known as "entero-enterostomy", known quasi-affectionately
by some as a "kissing-X". With elongation procedures patients
are generally able to maintain some degree of weight-loss due to
the "neuro-endocrine brake" effect, the same mechanism
responsible for weight-loss following Ileal Transposition surgery.
Ileal Transposition used as a method of intestinal elongation may
be used to treat cases of calcium and iron malabsorption following
Duodenal Switch. Unlike a conventional Ileal Transposition, when
used in these instances the Ileal Transposition can be performed
at the level of the duodenum, without having to re-connect the duodenum,
which - after Duodenal Switch - is no small feat. Such "High
Duodenal Ileal Transposition" procedures may use only a portion
of the alimentary limb to accomplish the transposition, using the
remainder of the alimentary limb for a "Parallel Ileal Transposition"
at the level of the biliopancreatic limb, which is at that point
incorporated back into the flow of food as a result of the High
Duodenal Ileal Transposition performed upstream. This approach allows
restoration of calcium and iron absorption without having to completely
reverse the Duodenal Switch procedure.
Occasionally patients have inadequate weight-loss, or weight regain
after a period weight-loss, following Duodenal Switch surgery. Two
conceptual approaches to this problem - assuming that a trial at
non-surgical weight-loss has failed - are to reduce the stomach
size and to shorten the common limb length. Results of these revisions
are variable, and, in North America at least, surgically reducing
stomach size seems to yield better results than common limb shortening.
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Metabolic Bone Disease
For patients suffering from osteoporosis as a result of weight-loss
surgery, there are options for treatment.
With any operation that results in bypassing the duodenum - such
as Gastric-Bypass and Duodenal Switch - malabsorption of calcium
occurs. The duodenum is the site of maximal absorption of calcium,
which is why Gastric-Bypass and Duodenal Switch patients require
calcium supplementation. Despite full supplementation, many patients
still show signs of malabsorptive metabolic bone disease from calcium
malabsorption. Calcium metabolism is monitored post-operatively
by measuring blood levels of calcium, vitamin-D, and parathyroid
hormone (PTH). It is important to maintain a normal vitamin-D level,
as this vitamin is important in maintaining normal calcium levels.
There are a few easily correctable situations that may result
in inadequate calcium absorption after these procedures: taking
the wrong form of calcium and taking iron supplements that interferes
with calcium absorption.
Not all forms of calcium are equally absorbable. Calcium citrate
and calcium apatite are known to be easily absorbed. The most common
form of calcium supplement - calcium carbonate - is actually poorly
absorbed. Many bariatric surgical patients, though, are advised
to take this form of calcium for their calcium needs. Although calcium
carbonate is quite helpful in preventing kidney stones in bariatric
surgical patients, it is a poor choice for preventing osteoporosis.
Patients need to be on a form of calcium that they can absorb.
Iron supplements are known to interfere with calcium absorption
as well. It is generally recommended that iron pills and calcium
pills not be taken within two hours of each other, which can make
scheduling one's supplement routine rather difficult. Iron and calcium
are both maximally absorbed in the duodenum, which is why metabolic
bone disease and anemia often go together in Gastric-Bypass and
Duodenal Switch patients. Many patients with iron deficiency will
push their iron supplementation to the point that it interferes
with their calcium absorption. In their attempt to raise their iron
levels to normal, patients worsen their calcium deficiency, resulting
in both anemia and osteoporosis. Many patients with iron deficiency
require iron infusions when iron pills fail to do the trick. To
many patients in this situation, this can be a cause of concern,
but it is easier to treat iron deficiency this way than it is to
treat calcium deficiency. If the choice is between taking iron pills
while putting calcium absorption at risk, or receiving iron infusions
while allowing calcium pills to be better absorbed, the clear choice
is to take the iron infusions.
Some patients continue to show signs of metabolic bone disease
despite high-dose calcium supplementation and healthy vitamin-D
levels. For these patients, reversal of their operation may be necessary.
Ideally, reversal should be limited to that part of the operation
that affects calcium malabsorption, without resulting in excessive
weight re-gain. For Gastric-Bypass patients, conversion to Vertical/Sleeve
Gastrectomy, with or without Ileal Transposition or Omentectomy,
is an effective way to accomplish this. The result is the re-establishment
of normal flow through the duodenum while adding the neuro-endocrine
brake effect for weight-loss maintenance. For Duodenal Switch patients,
a High Duodenal Ileal Transposition will accomplish the same effect
without having to totally reverse the patient's operation. Although
not the primary goal, revision bariatric surgery for metabolic bone
disease also has the effect of improving iron absorption.
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Vitamin Deficiencies
The two classes of vitamins most likely to be deficient in weight-loss
surgery patients are the fat-soluble vitamins (A, D, E, K) and certain
B-vitamins (B-1/Thiamine, Folate, B-12). Given the effectiveness
of oral supplements and vitamin injections, revision surgery to
treat these conditions is quite uncommon. Fat soluble vitamin deficiencies
are found mainly in Duodenal Switch patients, the most common deficiency
being vitamin-D. Elongation of the common limb, as is done for malnutrition/protein
deficiency, will usually remedy this problem.
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For
a comparison of the procedures our surgeons offer click
here. Please note VERGITO and Vertical/Sleeve Gastrectomy will
be added to chart soon.
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