1 INTRODUCTION
Data from the Ministry of Health show the increasing importance of
obesity in the health of the population. The change in habits has made
Brazil a country with fewer cases of malnutrition to the detriment of
the progressive increase in cases of obesity, with the age group most
affected between 45-64 years and similar distribution between men and
women¹.
Public policies are gradually trying to encourage healthy habits that
impact the population’s diet and lifestyle, as well as investment in
drug therapies to control obesity-related comorbidities¹. However,
conservative therapies have high rates of abandonment and are
ineffective.
Bariatric surgery, although effective, has limited
indications2, in addition to offering a risk of early
and late postoperative complications3. According to
the Brazilian Society of Bariatric and Metabolic Surgery, from 2012 to
2017, the number of bariatric surgeries in the country increased by
46.7%. In the midst of this scenario, this type of surgery has aroused
surgeons’ interest in improving and modernizing their techniques, as
well as in addressing their complications, aiming at a safer and more
effective treatment4.
The most used operative techniques are gastric bypass (Roux-en-Y gastric
bypass) and vertical gastrectomy (Sleeve). Gastric bypass is a mixed
technique, in which the disabsorptive component is provided by the
extension of the intestinal bypass. Several modifications of this
technique were created in an attempt to improve weight loss and reduce
the number of complications5.
Fobi and Capella proposed the placement of a silicone ring in the
gastric reservoir, just above the gastrojejunal anastomosis, in order to
calibrate its diameter and prevent a possible dilation that would cause
weight recovery in the future. Despite the benefit, patients who
underwent gastric bypass surgery with a ring may experience late
complications of the technique such as food intolerance, erosion, or
ring migration5. The classic treatment for
complications is the surgical removal of the ring, but this approach
offers great morbidity and mortality due to possible complications.
However, several techniques have been developed, in order to solve the
cases in a less invasive way, through endoscopic procedures, without the
need for surgical reintervention6.
Among the endoscopic techniques, there is the endoscopic removal of the
ring through the use of accessories (scissors), pneumatic balloon
dilation, and the application of gastric stents (plastic or metallic)
with peculiar and specific indications for each type of complication.
Erosion of the retaining ring is a rare
complication7,8 with an incidence of 1% to 7% of
patients in the postoperative period. The clinical picture can be
asymptomatic as an endoscopic finding or vary from mild symptoms such as
epigastric pain, nausea/vomiting, obstructive symptoms and changes in
weight (recovery or excessive loss), to more serious complications such
as bleeding, intra-abdominal abscess, and fistula
formation9.
When less than 50% of the ring is visible through gastric light, one
can use the prosthesis (metallic or plastic) for a period of one to two
weeks to accelerate the erosion process, which is based on the necrosis
provided by the ischemia in the gastric wall between the prosthesis and
the retaining ring8.
Ring intolerance may be secondary to gastric stenosis promoted by the
ring in its usual position or due to distal sliding. Stenosis can cause
constrictive symptoms; the contrasted examination may show a narrowing
in the region of the device and, on endoscopic examination, an
insurmountable ring constriction or laborious passage of the endoscopy
device is noted8.
The slip corresponds to the displacement of the prosthesis externally to
the gastric pouch in a distal direction that promotes the riding on the
jejunal loop, generating extrinsic compression and the consequent
difficulty in emptying the gastric pouch with an incidence of less than
1%9. Such slippage can be total or partial,
generating a picture with lesser or greater feeding difficulties and
vomiting, respectively. The diagnosis of slippage can be performed by
means of contrasted radiography observing a poor positioning of the ring
in early cases, or even in the identification of late findings such as
the increased diameter of the gastric pouch, hydro-aerial level, and
wide anastomosis. At the endoscopic examination, dilation of the gastric
pouch, gastric residue, esophagitis due to vomiting, the convergence of
jejunal folds, and even mucosal prolapse to the gastric chamber.
The treatment for this condition can be carried out with the rupture of
the ring by the use of a pneumatic balloon dilator or the extraction of
it by the use of stents (plastic or metallic).9 The
dilation mechanism aims at the rupture of the wire inside the ring by
inflating the balloon used for the treatment of achalasia, which has
sufficient radial force to rupture the device. Through endoscopic
examination, the guidewire is passed through the efferent loop, and,
with the aid of fluoroscopy, the pneumatic dilator balloon (30 mm) is
positioned so that it is enclosed by the ring when it is inflated and
its rupture in the ring must be accompanied by
radioscopy.10
The dilation of the esophagogastric transition (TEG) and gastrojejunal
anastomosis should be avoided in case of distal migration of the device
since jejunum loops are not as resistant and offer a high risk of
perforation for the procedure. The success rate of one study revealed
66% of the complete rupture of the ring. However, in the other 34%,
clinical improvement was successful, even without rupture of the
device10.
The use of a gastric prosthesis, whether plastic or metallic, may be
indicated in cases of partial erosion of the band (<50%) or
when there is an indication for ring extraction, but there is no
migration of it to the interior of the gastric chamber8. This procedure
causes progressive erosion of the ring into the lumen of the stomach,
due to the ischemia caused between the prosthesis and the ring due to
the compression of the stomach wall10. In the market
there is no longer the manufacture of plastic stents previously used
(Polyflex - Boston Scientific®), therefore, currently, metallic stents
fully covered for this type of treatment are used.
Prosthesis implantation and extraction procedures are preferably
performed in the operating room, under general anesthesia and with the
aid of fluoroscopy. External markings with radiopaque materials can be
used to facilitate the probable location of the prosthesis, which should
encompass the ring in its middle portion.11 The
proximal end should be located below the level of the diaphragmatic
hiatus to avoid pathological gastroesophageal reflux and the distal end
should be placed in the efferent loop. After a period of 10 to 15 days,
the stents are extracted through the mouth with the aid of grasping
forceps, and in that period more than 50% of the rings are migrated
into the gastric chamber.12 If the ring is not
extracted next to the prosthesis, it can be removed with grasping
forceps similar to the removal of a foreign body13.
However, if it is not extruded, but only apparent in the gastric
chamber, it must also be removed after 30 days, with the aid of
endoscopic scissors and grasping forceps.
In general, complications related to the procedure are mild, such as
nausea/vomiting, abdominal pain, migration, and late stenosis in the
ring region, which can be treated with balloon dilation
later13. Serious complications have not yet been
reported in the literature.
Despite being used to increase the restrictive effect of bariatric
surgeries, the gastric containment ring is prone to complications, such
as slipping and erosion and consequent side effects, such as food
intolerance. One of the modalities used in the endoscopic treatment of
this condition is the endoscopic extraction through the use of Stents
and that configures a minimally invasive, safe and effective alternative
to the detriment of the surgical treatment that is less and less used
due to its higher morbidity and mortality.