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Laparoscopic sleeve gastrectomy: its place in
bariatric surgery for the severely obese patient
Laparoscopic sleeve gastrectomy (LSG) is one of many
bariatric procedures used for weight loss and the resolution of obesity-related
comorbidities in severly obese individuals. It has evolved from a series of
other operations and has become increasingly popular as stand-alone bariatric
procedure.1,2
LSG was initially used as a staging procedure for high-risk
patients undergoing bariatric surgery prior to biliopancreatic diversion with
duodenal switch (BPD-DS) or Roux-en-Y gastric bypass (RYGB). It has now being
increasingly favoured as a single-stage procedure with the major advantage over
other bariatric procedures being that it is less invasive whilst still achieving
comparable weight loss.
At Counties Manukau District Health Board, South Auckland,
over 500 LSG procedures were performed between 2006 and 2011. This article
discusses the use of LSG as a single-stage procedure for the treatment of
obesity and related comorbidities.
MethodsA literature review was conducted independently by two
authors (DPL, PPS). Several medical databases were utilised including MEDLINE,
Scopus, Pubmed and EMBASE from inception to August 2011. The search terms used
were ‘sleeve gastrectomy’, ‘laparoscopic sleeve
gastrectomy’, ‘LSG’, ‘bariatric surgery’,
‘weight loss surgery’, ‘obesity surgery’,
‘obesity’, ‘complications’, ‘outcomes’,
‘weight loss’, ‘comorbidity’ and ‘comorbidity
resolution’. Additional articles were recovered by scrutinising reference
lists in recovered articles by two authors (DPL, SS). There were no specific
exclusion criteria.
The history of the sleeveLSG is vertical gastrectomy to create a tubular stomach
approximately 100–150 ml in volume3
(Figure 1). This concept was initally developed in the setting of anti-reflux
surgery by Lawrence Tretbar who was able to demonstrate weight loss following
fundoplication.4
In 1988, Doug Hess modified this concept by substituting
plication with a vertical gastrectomy to develop a sleeve. This become part of
the BPD-DS,2–5 and had the advantages of
leaving an intact pylorus, which prevented dumping syndrome, and utilising a
dudodenal-enteric anastomosis which helped prevent marginal
ulcers.5
BPD-DS was first attempted laparoscopically in 1999 on
pigs.6 With this proving to be feasible, it was
attempted in humans. However, it was noticed that for patients with higher BMI,
there was an increased incidence of postoperative
morbidity.3 In order to solve this, it was
decided to split the restrictive and malabsorptive components of the procedure
by performing LSG as the first stage followed by the laparoscopic enteric
anastomosis as the second stage.3
Eighteen cases were performed between September 2000 and
September 2001 and there was noted to be a drastic reduction in the incidence of
major morbidity.3.
Figure 1. Diagram of laparoscopic sleeve
gastrectomy
![]() © Albert Maier, Illustration + Graphic
Design.
LSG as a primary procedure was first reported in the
literature in 20037,8 with the report showing
excellent weight loss results. These results have been compared to other more
established bariatric procedures and have been shown to be comparable to
laparoscopic Roux-en-Y gastric bypass (LRYGB) and BPD-DS with less morbidity and
superior weight loss results compared to laparoscopic adjustable gastric banding
(LAGB) 1, 9-12. This weight loss has been
attributed not only to anatomical restriction but also to significant hormonal
suppression inducing early satiety which is not demonstrated after LAGB and more
so than that seen in LRYGB.1,13
Mechanism of weight lossLSG is classified as a restrictive procedure, affecting
weight loss through anatomical restriction.14
As understanding of the factors which regulate appetite increase, it is now also
believed that LSG also affects weight loss through the modulation of gut
hormones.1,9,13
Several studies have demonstrated that circulating levels of
ghrelin, a hormone thought to increase appetite, are significantly decreased
early after LSG leading to earlier satiety.1,13
This is thought to occur as a result of removing the fundus which is where
ghrelin producing cells are located.15
Studies have also been conducted comparing the effects of
LSG versus other bariatric procedures on gut hormones. One study demonstrated
that while ghrelin levels are significantly lower following LSG, LAGB has little
to no effect on circulating levels of
ghrelin.11 It has also been shown that LSG is
superior to LRYGB in its effects on gut hormones, which not only regulate
appetite but also those that regulate glucose
homeostasis.15,16
Selection criteriaEstablished patient selection guidelines exist within the
current literature including the American National Institutes of Health (NIH)
Consensus Statement on Gastrointestinal Surgery for Severe Obesity and the
Interdisciplinary European Guidelines for Surgery for (Morbid)
Obesity.17,18.
Criteria for referral include patients with a body mass
index (BMI) greater than or equal to 40 kg/m2
alone or BMI greater than or equal to 35 kg/m2
with at least one comorbidity which is improved by surgically induced weight
loss, and have tried and failed to lose weight or maintain weight loss despite
appropriate non-surgical care. Individual bariatric centres will also have local
guidelines which may have additional considerations specific to their practice
or institution.
Contraindications to surgery are detailed in these same
guidelines. As detailed in the European guidelines, these include absence of
periods of identifiable medical management, inability to participate in
prolonged follow-up, presence of non-stabilised psychiatric disorders, alcohol
abuse and/or drug dependencies, diseases which are life threatening in the short
term and inability to care for oneself or absence of social
support.18 These conditions are standard for
all bariatric procedures. Currently, there are no specific indications which
would select patients for a specific bariatric procedure.
EfficacyWeight loss—There is an increasing
amount of literature to support the use of LSG as a single stage procedure.
Studies have demonstrated that LSG produces weight loss results in the short
term which are comparable to, and in some cases superior to, other more
established bariatric
procedures.15,19–22
A recent systematic review of LSG found that the mean
percentage excess weight loss (%EWL) at 1 year was 59.8% (range of 46% to
83.3%).23 For follow-up at 2 and 3 years, the
mean %EWL was 64.7% and 66% respectively.23
This compares favourably to weight loss results reported for LRYGB which at 1, 2
and 3-year follow-up achieved a mean %EWL of 62.8%, 54.4% and 66%
respectively.23 However, when compared to %EWL
for LAGB of 37.8%, 45% and 55% at 1, 2 and 3 years respectively, LSG appears to
achieve superior weight loss.23
A randomised controlled trial conducted by Kehagias and
colleagues found LSG and LRYGB to equally safe and effective
procedures.24
Though there is robust evidence demonstrating excellent
short to mid-term weight loss results after LSG, there is a lack of long-term
data to show the durability of these results. Himpens and colleagues reported
follow-up data for 41 out 53 patients who underwent LSG out to 6 years and
showed a mean %EWL of 57.3%, though this had decreased from 72.8% at 3
years.25
Similarly, in a series of 26 patients who underwent LSG,
Bohidjalian and colleagues found a reduction in %EWL from a peak of 60.3% at
2-year follow-up to 55% at 5-year follow-up 26.
The longest follow-up data available from Sarela and colleagues reports %EWL in
19 patients assessed at up to 9 years postoperatively of which 11 had sustained
%EWL greater than 50%.27
It is thought that though LSG affects short-term weight
loss, there is a tendency towards weight regain which has been demonstrated in
series that report follow-up greater than 5
years.28 With this in mind, it is unclear
whether a second stage procedure is required for patients who undergo LSG and
longer follow-up data are required to clarify this.
Comorbidity resolution—The current
literature suggests that LSG is effective at resolving obesity related
comorbidity. Shi and colleagues reported in their systematic review comorbidity
resolution rates of between 45% to 95.3% in patients with type 2 diabetes
mellitus (T2DM) hypertension, obstructive sleep apnoea (OSA), hyperlipidaemia,
osteoarthritis, gastroesophogeal reflux, depression and peripheral oedema at 12
to 24 months follow-up 23. Resolution of
urinary incontinence in women after LSG has also been reported by Srinivasa and
colleagues who found a resolution rate of 90% at 12
months.13
The majority of the literature describes the efficiacy of
LSG at resolving T2DM. Reported resolution rates for T2DM are in the range of
63%-100%.29–31 LSG has been shown to be
not only comparable, but often superior, to other laparoscopic bariatric
procedures with regards to T2DM resolution.
Abbatini and colleagues reported that diabetes resolution
after LSG was 80.9% at three months.30 This
result was comparable to LRYGB at 81.2% and superior to LAGB at
60.8%.30 Omana and colleagues demonstrated
significant resolution of diabetes after LSG with a result of 100%. This was
again vastly superior to LAGB (46%).31
Though the current evidence is consistent that LSG is
superior to LAGB with regards to T2DM resolution, there is still some conjecture
when compared to gastric bypass with a recent randomised controlled trial by Lee
and colleagues showing T2DM resolution to be significantly higher in
laparoscopic mini gastric bypass at 12 months
follow-up.32 How this resolution occurs in LSG
is not well understood. Initially, resolution was attributed to weight loss.
However, biochemical improvement has been shown to occur well before weight
loss,30 and may be related to neuro-hormonal
mechanisms.
There is also substantial evidence describing the efficacy
of LSG with regards to resolution of hypertension and obstructive sleep apnoea.
Complete resolution of hypertension ranges from 55% through to 93% at 6 to
18-month follow-up with a mean resolution rate of 71.7% out to 24
months.23 Similarly, resolution rates of OSA
have shown to be acceptable with rates ranging between 52.6% to 100% with a mean
rate of 83.6% at 24 months follow-up 23.
Other benefits of LSG—Though weight
loss and comorbidity resolution are the most recognised outcomes of this
procedure, LSG also offers other postoperative benefits. These benefits are
described in Box 1.
Box 1. Additional benefits of
LSG
ComplicationsThe postoperative complication rate reported in the
literature varies from 1 to 29% after LSG.33
This may depend on surgical technique (bougie size, amount of antrum excised,
staple-line re-inforcement etc), patient factors, complication definitions and
the follow-up period. This complication rate is comparable to other more
established bariatric procedures.
The major complications associated with single stage LSG are
listed in Box 2. This is not an exhaustive list and the incidence of each of
these complications is low. The Michigan Bariatric Surgery Collaborative
reported on the largest LSG series. This included 854 patients who underwent LSG
between 2006 and 2009 across 25 hospitals and 62 surgeons and they reported a
major complication rate of 2.2%.34
In a retrospective comparative analysis, Lakdawala and
colleagues showed no difference in complication rates between LRYGB and
LSG.21 There have also been shown to be no
significant difference in complication rates when compared to
LAGB.35
Staple line leak—The risk of staple
line leak is the greatest concern for bariatric surgeons and patients. Leak
rates range between 0–7% with a mean occurrence of
2.4%.36 Staple line leak is associated with
significant morbidity, prolonged convalescence and increased risk of mortality.
It is difficult to manage with little consensus in the current literature
regarding an optimal treatment approach.
Most leaks occur relatively early after surgery which often
makes surgical management difficult due to poor tissue quality and
inflammation.37 The placement of endoscopic
stents and percutaneous drains in conjunction with gut rest and parenteral
nutrition is generally the preferred management option though resolution often
takes an extended period of time.36
Box 2. Major postoperative complications
associated with LSG
Effectiveness in the super-obeseSurgical risk is thought to increase significantly with BMI
greater than 50 kg/m2. It is recognised as an
independent predictor of postoperative morbidity and mortality, and this has
been attributed to a greater burden of obesity-related
comorbidity.38–40
Previous studies have investigated postoperative morbidity
in super-obese patients after laparoscopic bariatric surgery and found increased
rates of postoperative complications.41,42 As
mentioned previously, LSG was initially used as the first stage of BPD-DS in
high-risk patients and this stepwise approach was demonstrated to decrease
postoperative mortality.
Though it is thought that LSG is safe in the super-obese
population, it is unclear whether it is effective in producing satisfactory
weight loss in these patients. Several studies have demonstrated that although
LSG affects excellent absolute weight loss in this group of patients, a large
proportion remain with a BMI of more than 40
kg/m2 at follow-up of 12–18
months.9
According to European guidelines, these patients would still
qualify for further bariatric surgery which may suggest that LSG might be more
effective as a staging procedure in this select group of
patients.18 This is supported by a recent
systematic review which found that studies identifying patients as super-obese
or high-risk were likely to have a second stage procedure approximately 2 years
after the initial LSG. More long-term follow-up data are required to clarify
this.20
ConclusionLSG is an increasingly popular stand alone bariatric
procedure. It produces significant and sustainable weight loss in severely obese
patients and effectively cures obesity related comorbidity. It is safe with a
major complication rate which is comparable to other common bariatric
procedures. With the majority of the literature reporting short to mid-term
weight loss results, further research is required to investigate long term
weight loss outcomes. Further research is also required to investigate the
efficacy of LSG in super-obese patients.
Competing interests: None known.
Author information: Daniel P Lemanu,
Research Fellow1; Sanket Srinivasa, Research
Fellow1; Primal P Singh, Research
Fellow1; Andrew G Hill, Professor of
Surgery2; Andrew D MacCormick, Senior Lecturer
in Surgery2
Correspondence: Dr Daniel
Lemanu, Research Fellow, Dept of Surgery, South Auckland Clinical School,
Middlemore Hospital, Private Bag 93311, Otahuhu, Auckland, New Zealand. Fax: +64
(0)9 2760066; email: Daniel.Lemanu@middlemore.co.nz
References:
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