DISCUSSION
The IGB treatment is a well-recognized therapy for
overweight/obesity[2,3,12,13] and have been
successfully used for weight loss for the last 20
years.[14] The mechanism of action of IGB is
multifactorial and incompletely understood.[21,22] Theoretically IGB affects both the stretch
receptors and the gastric capacity, increases satiety while decreasing
the residual volume available for food, as well enlarging the gastric
emptying time, and therefore could be considered a restrictive procedure
to treat obesity.[15] Other proposed mechanism
include changes in appetite-regulating hormones (decrease in ghrelin and
leptin and increase in CCK concentrations); however there are
conflicting reports. [21,22] The better results
with IGB occur when the treatment is associated with behavioral
changes.[2,3,12,13]
However, it is not possible to define the ideal balloon size for a
specific patient, as the threshold for nausea, vomiting and/or abdominal
pain are not measurable or predictable.[8]Moreover, a decrease in IGB efficacy in promoting weight loss due to a
reduction of the satiety effect after three months has been demonstrated
in some studies.[15-17]. However, the traditional
IGB have some limitations: a decrease in the efficacy in promoting
weight loss after 2 to 3 months , a maximum length of treatment is
6-month and a significant rate of complications during the early
implantation period (nausea, vomiting, and discomfort), leading balloon
extraction in 4–5% of patients.[5,12, 15-17] It
is not possible to define the ideal balloon size for a specific patient,
as the threshold for nausea, vomiting and/or abdominal pain are not
measurable or predictable.[8] The introduction of
the Spatz3® Adjustable Balloon system offers features
that address these limitations.
The main complication was the early removal of the balloon (removal
before nine months post implantation). However, most of these (n=12,
6.66%) were not due to adaptation symptoms, but for various other
reasons, such as desire to give up the treatment, weight loss considered
insufficient by the patient, and psychological intolerance (desire to
eat, desire to remove the foreign device from the inside of the body).
Only two removals (1.11%) were performed due to severe symptoms
(excessive vomiting) in patients who did not wish to do the downward
adjustment and decided to quit the treatment. The incidence of early
removal in the present study was 7.77%, being similar to that observed
in other studies conducted with Spatz, Machytka et al
(2014)[6] observed 7.79% and Brooks et al
(2014)[14] 5.47%. However, this rate is higher
than the observed in studies conducted with conventional IGB, Genco et
al (2005)[9] observed 0.44%, Lopez-Nava et al
(2011)[12] 0.8% and Sallet et al
(2004)[1] 3.4% . It is important to note that
from the 14 early removals in this study, only 2 (1.24%) were due to
early intolerance, approaching to the results previously described.
Furthermore, patients who underwent downward adjustment (n = 8; 4.44%),
all, without exception, completed the minimum 9 months treatment,
similar to what was observed in other Spatz® IGB
studies.[6,14] Thus, it seems that the downward
balloon adjustment may contribute to a better adaptation and a lower
early removal rate.
There were three cases (1.66%) of spontaneous deflation before nine
months post implantation, the minimum time length established for
treatment, with immediate replacement of the defective balloon and
permanence in the treatment. This index is lower than the observed by
Machytka et al (2011)[8] in
Spatz® initial series (11.11%), but they used first
and second generation Spatz® balloons, while in the
present study we used only the third generation, that was described as
having easier implantation and extraction procedures which are less
complicated with fewer steps.[6] When compared
with the study conducted by Brooks et al
(2014)[14], that also used third generation
Spatz® balloons, the spontaneous deflation index of
the present study (1.66%) was lower (vs. 4.1%).
In one (0.55%) patient it was detected, at the tenth week of treatment,
gas production inside the balloon, when the patient started to vomit
again. An x-ray of the abdomen was performed, being observed air-fluid
level inside the balloon. The balloon was then completely emptied and
filled again with 3% sterile saline plus 10 mL of 4% methylene blue,
the patient remained in the treatment without any problems and without
the need for removal or replacement of the balloon. This complication
has not been reported in any other Spatz® balloon
study, and is believed to have happened, possibly, due to contamination
of the liquid inside the balloon by anaerobic bacteria from the
gastrointestinal tract.
There was one case (0.55%) of upper gastrointestinal bleeding without
hemodynamic repercussions. At the endoscopy, was detected the presence
of a tear in the gastroesophageal junction due to excess vomiting after
an upward balloon adjustment. It was then removed half of the upward
adjustment volume, with prompt improvement in symptoms and permanence in
the treatment, with no need for balloon removal. Machytka et al
(2014)[6] also showed one case (1.29%) of upper
gastrointestinal bleeding, but due to gastric ulcer.
Regarding gastric ulcers, six (3.33%) were diagnosed in the gastric
antrum lesser curvature. One of them (0.55%) needed the removal of the
balloon due to intense pain and depth of the lesion. When asked, the
patient said that was not taking the prescribed proton pump inhibitor
(PPI). Five (2.77%) other ulcers were asymptomatic and were diagnosed
during treatment (during an adjustment procedure) or at the removal of
the balloon. All of them were treated conservatively with increasing PPI
dose and sucralfate, with adequate response and wound healing. The
incidence of ulcers is higher in studies using Spatz®balloons (Machytka et al (2014)[6]- 1.29% and
Brooks et al (2014)[14] – 2.73%) than in studies
using traditional balloons (Genco et al (2005)[2]– 0.2% and Sallet et al (2004)[1] – 0%). This
can be possibly explained by the fact that the Spatz®balloon does not have a completely smooth surface, since it has a tail,
which acts as a compression point on gastric
mucosa[8], and could generate a pressure ulcer.
There was in this study no case of gastric perforation, esophageal
perforation or death.
Weight loss has traditionally been the main outcome measure of the
efficacy of IGB treatment and was observed in the majority of our
patients. The %EWL in the present study was similar or slightly
superior than that observed in other Spatz® series
reported in the literature (Table 5 ).
However the weight loss after the upward adjustment in the present study
was lower than in other Spatz® studies (Table
5 ). This can be possibly attributed to the fact that in our study the
upward adjustment was performed latter (7.12±1.63 months) than in the
studies conducted by Machytka et al (2014)[6] and
Brooks et al (2014)[14] , in which the mean
adjustment time was 4.1 and 5.8 months, respectively, allowing more time
for further weight loss. Or, more feasible, the upward adjustment is not
effective in promoting extra weight loss.
In this study, the upward adjustment was done in all patients in the
upward adjustment group. The incidence of this procedure (47.77%, n=86
of 180) was higher compared to Spatz® series of Genco
et al (2013)[9] and Machytka
(2014)[6], with 22.5% and 19.48% of upward
adjustments, mainly by weight plateau. However, the percent of excess
weight loss of patients that did the adjustment was not significantly
higher when compared to those that did not. Similarly, Genco et al
(2013)[9] reported that final mean BMI of the
patients who did upward adjustment was higher than patients with
Spatz® who did not, but there was no statistical
significance and they highlighted that this observation was in a few
number of patients and needed to be confirmed.
Considering our study model, the sample size is limited, but reasonable
for a prospective study, and larger than other studies with this
balloon. This study has limitations and the major one is the absence of
a sham group, difficult to be done in a private center. However, in our
opinion, the possibility to evaluate the real life tolerance, efficacy
and complications associated with the use of Spatz3®IGB, and the presence of a control group (non adjustment group)
compensate the absence of a sham group.
The long lasting treatment (one year) allows a longer nutritional
counseling, in order to increase patient compliance and to reinforce the
necessity of behavior changes from the very early stages of treatment.
Patients should be aware that is important not only to lose weight, but
to keep a sustained loss, as described by different authors.[18-20] Even with one year treatment, the majority
of the patients still have obesity (final BMI 32.84kg/m² only four
patients with BMI<25kg/m²). The Spatz3® use
does not represent a definitive treatment to obesity and is necessary to
be associated with permanent behavioral changes and probably a second
balloon treatment. At this time, there is no contraindication to use the
Spatz3® for a sequential therapy as traditional
IGBs.[9]
Therefore, this study shows that Spatz3® IGB treatment
is an effective procedure for weight reduction, without mortality but
with higher morbidity rates when compared to tradition IGBs. Currently,
the IGBs offer a safe and effective weight loss option for patients. It
is cristal clear that the downward adjustment reduces the incidence of
early removals due to intolerance. However, it is not clear if the
upward adjustment is effective in promote extra weight loss, since all
the analyzed parameters did not show statistical difference between both
groups. On the other hand, the adjustment group showed a slightly higher
treatment success rate. Additional clinical trials are necessary to
better understand the difficulties and problems with
Spatz3® IGB use, and the efficacy of the upward
adjustment.