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REVIEW ARTICLE
Imaging in bariatric surgery: service set-up, post-operative
anatomy and complications
1
S SHAH, MRCP,FRCR,
1
V SHAH, MRCP,FRCR,
2
A R AHMED, FRCS and
1
D M BLUNT, MRCP,FRCR
1
Department of Imaging and
2
Department of Bariatric Surgery, Imperial College Healthcare NHS Trust, London, UK
ABSTRACT. Obesity is an increasingly prevalent and costly problem faced by the
healthcare system. The role of bariatric surgery in managing obesity has also increased
with evidence showing a reduction in long-term morbidity and mortality. There are
unique challenges faced by the radiology department in providing an imaging service
for this population of patients, from technical and staffing requirements through to
the interpretation of challenging post-surgical images. We describe these challenges
and provide an overview of the most frequently performed procedures, normal post-
operative imaging findings and the appearance of common complications.
Received 9 January 2010
Revised 1 March 2010
Accepted 3 March 2010
DOI: 10.1259/bjr/18405029
’2011 The British Institute of
Radiology
Obesity
Obesity is a multifactorial disease, which is increasing
in incidence and prevalence. In 2006, 67% of men and
56% of women were classified as being either overweight
or obese in England [1]. Overall, 24% of adults were
classified as obese, an increase from 15% in 1993, and
16% of children aged 2–15 years were classified as obese,
an increase from 11% in 1995. Estimates suggest that at
the current rate of increase, by 2010 there will be 12
million adults and 1 million children categorised as
obese. The body mass index (BMI, kg m
-2
) is the most
widely used measure of obesity; BMI between 25 and 30
signifies being overweight and BMI greater than 30
signifies obesity. BMI greater than 35 with obesity-
related serious comorbidities or greater than 40 with or
without comorbidities is defined as morbid obesity.
It is increasingly recognised that the consequences of
obesity on general health are far reaching. Comorbidities
associated include hypertension, diabetes mellitus,
ischaemic heart disease, dyslipidaemia, osteoarthritis,
obstructive sleep apnoea and psychological morbidity.
As well as a burden on the general health of the
population, there is a huge financial burden associated
with obesity. The Health Select Committee reported that
the cost of obesity and being overweight is between £6.6
and £7.4 billion per year. If current trends in obesity
continue, these costs may rise to between £7.5 and £8.4
billion per year [2]. Therefore, a 1% reduction in the
prevalence of obesity may yield a saving between £66
and £74 million per year.
Lifestyle and pharmacological interventions have been
the main options available to health professionals caring
for this population. However, there is an increasing
volume of literature expounding the benefits of bariatric
surgery. Recent studies suggest that as well as inducing
significant weight loss it may help reverse some of the
metabolic consequences of obesity [3]. In addition, there
is now evidence that bariatric surgery reduces long-term
mortality by 29–40% [4, 5].
The National Institute for Health and Clinical
Excellence (NICE) published updated guidance in 2006
regarding the management of obesity (Table 1) [2]. The
estimated cost of implementing the NICE guidance is £63
million in the first year; the cost savings of a 1%
reduction in obesity prevalence would return this sum.
NICE emphasise the importance of undertaking
surgery only at centres where a multidisciplinary team
approach is used. Optimum outcomes are achieved
where the multidisciplinary team consists of surgeons
trained adequately in the appropriate techniques as well
as allied health professionals such as dieticians, psychia-
trists and specialist nurses. In addition, rigorous selec-
tion criteria should be applied and surgery should only
be undertaken at high-volume centres; these factors may
help reduce in-hospital deaths [6]. NICE also state that
an essential component in a successful service is the
provision of a diagnostic and interventional radiology
service by well-trained radiologists and radiographers.
Service set-up
As with any new service set-up, there is an analysis of
the demand for the service against the costs, health and
financial benefits of providing the service. The commis-
sioners of the service must ensure that the service is
integrated with other local health and weight manage-
ment programmes [2]. They must also ensure that
Address correspondence to: Dr S Shah, Department of Imaging,
Imperial College Healthcare NHS Trust, London, UK. E-mail:
sachit.shah@doctors.org.uk
The British Journal of Radiology, 84 (2011), 101–111
The British Journal of Radiology, February 2011 101
appropriate referral and assessment criteria are estab-
lished, and frequent review of the clinical outcomes is
undertaken to maintain a high-quality service. Under the
new payment by results (PbR) system, a fixed tariff is
paid by the primary care trust (PCT) to the hospital trust
for specific procedures. There is also an additional
inflationary cost added to reflect the local population.
This income is then used to pay the overheads for the
service, recruitment and employment of surgeons and
specialist nurses. Allocated amounts are paid to the
theatres, imaging and pathology departments. Generally,
the income distributed to the imaging department is a
fixed proportion of the surgical department’s income,
regardless of the types of operation being performed.
Whilst some operations require no imaging follow-up,
many do, and the cost of providing the imaging service
has to be met by the fixed income from the surgical
department. In the near future, many imaging depart-
ments may move to a similar PbR-type system, i.e. they
are paid for individual units of work rather than a lump
sum.
The specific challenges faced by the imaging depart-
ment can be divided into three categories: technical
factors, training issues and service provision. With
regards to technical factors there are issues relating to
weight and size limits, image quality and radiation dose
imparted. The weight and size limits of individual pieces
of imaging equipment need to be outlined specifically in
a policy document prior to the initiation of such a
service. Typical and representative examples from our
own department include: diagnostic and fluoroscopic
radiology (weight limit 137 kg), CT (width limit 70 cm,
weight limit 200 kg), MRI (width limit 60 cm, weight
limit 200 kg), interventional radiology (weight limit
200 kg), ultrasound (weight limit 175 kg) and nuclear
medicine (weight limit 175 kg). The width limits usually
refer to the shoulder-to-shoulder distance. However, in
this group of patients, it is often the abdomen which
exceeds the width limit. Being able to acquire images of
diagnostic quality is a further challenge; owing to the
large volume of soft tissue there is increased absorption
of the X-ray beam and higher currents need to be used.
There is also increased scatter of radiation; both these
factors mean that there is an increased radiation dose
imparted on the patients and the operators. The contrast
resolution of these studies is compromised. This is
important because often the key question is whether
there is a leak of water-soluble contrast from the site of
surgery, and detecting small volumes of leaked contrast
may be extremely difficult owing to poor image
resolution. Similarly, ultrasound is often an unsatisfac-
tory modality to use in these patients because of the
absorption and poor reflection of ultrasound waves by
the large volume of soft tissue.
The surgical procedures performed on these patients
are unique and it is important that radiologists are
specifically and adequately trained in the appropriate
imaging techniques and normal and abnormal imaging
appearances. When the service was started at our
institution, the lead surgeon provided a lecture on the
surgical techniques used, their expected normal post-
operative imaging findings and common complications.
Similar to a surgeon learning operative techniques, there
is a learning curve for radiologists in imaging these
patients. For the first 6 months, regular meetings were
held between the surgical and radiology teams to discuss
specific cases with a view to establishing experience and
a ‘‘database’’ of normal and abnormal findings. This is
an important facet in the training of both junior
radiologists and surgeons involved in the service. As
well as the radiologists specifically involved in gastro-
intestinal (GI) imaging, all other radiologists providing
an ‘‘on-call’’ service, radiographers and interventional
radiology nurses needed to be trained in issues speci-
fic to the imaging of bariatric patients. In many parts
of the UK, training of radiologists is moving towards
a modular programme based on tutorials on the Radi-
ology-Integrated Training Initiative (RITI) website [7]. A
module on imaging following bariatric surgery is
currently not available. In light of the increasing use of
these surgical techniques, a module would be extremely
useful for radiology trainees.
There are several logistical factors involved in provid-
ing such a service. Fluoroscopy is one of the main
imaging modalities used in the post-operative period
and commonly patients are imaged in the first 48 hours
following the procedure. There must be adequate space
on the routine fluoroscopy lists to be able to accom-
modate these patients at short notice and if there are no
planned lists there must be fluoroscopy facilities, radio-
graphers and radiologists available to provide the ser-
vice as and when required. This may impact significantly
on the out-of-hours service if there is a high volume
of patients being operated on or if theatre lists are
scheduled for the latter part of the working week.
Similarly, there will be an expected increase in the use
of CT and interventional radiology services for these
patients.
Table 1. National Institute for Health and Clinical Excellence guidance regarding surgical management of obesity [2]
Consider surgery for people with severe obesity if:
BMI >40 kg m
-2
or more, or 35–40 kg m
-2
and other significant disease (e.g. Type II diabetes or hypertension) that could be
improved if they lost weight
All appropriate non-surgical measures have been tried but have failed to achieve or maintain adequate, clinically beneficial
weight loss for at least 6 months
They are receiving or will receive intensive management in a specialist obesity service
They are generally fit for anaesthesia and surgery
They commit to the need for long-term follow-up
Consider surgery as a first-line option for adults with a BMI .50 kg m
-2
in whom surgical intervention is considered appropriate;
consider orlistat before surgery if the waiting time is long.
BMI, body mass index.
S Shah, V Shah, A R Ahmed and D M Blunt
102 The British Journal of Radiology, February 2011
Bariatric surgical procedures
There are three main categories of surgical procedure:
restrictive procedures induce weight loss by substan-
tially reducing gastric capacity and promoting early
satiety, examples include laparoscopic adjustable gastric
banding (LAGB) and sleeve gastrectomy (SG); malab-
sorptive procedures (e.g. jejunoileal bypass and biliopan-
creatic diversion) surgically alter the gut to limit nutrient
absorption from the small intestine, but are not now
commonly performed; and combined restrictive and
malabsorptive approaches include the Roux-en-Y gastric
bypass (RYGB), although the primary mechanism of
weight loss is thought to be restrictive rather than
malabsorptive [8]. Many of the procedures are now
performed laparoscopically with the advantages of
decreased recovery time and reduced number of
complications. Currently, the two most commonly
performed procedures worldwide are RYGB and
LAGB, followed by sleeve gastrectomy [9, 10].
Roux-en-Y gastric bypass
Surgical technique
Originally introduced in the 1960s and 1970s, RYGB is
now the most commonly performed bariatric procedure
in North America [10, 11]. Several variations are
currently in use, but in general involve the following
steps (Figure 1). First, a gastric pouch is formed by
separating it from the rest of the stomach, now referred
to as the gastric remnant. This is achieved by physically
dividing the pouch from the remnant using a cutting
stapler. Next, the jejunum is divided approximately
50 cm distal to the ligament of Treitz, and brought up to
create a gastrojejunostomy with the gastric pouch,
usually via a side-to-side (functionally end-to-side)
anastomosis. This anastomosed jejunal loop is referred
to as the Roux or alimentary limb and can be placed
‘‘retrocolic’’ through an opening created in the trans-
verse mesocolon or ‘‘antecolic’’ in front of the transverse
colon (Figure 2a), it can also be placed ante- or retro-
gastric. To complete the operation a jejunojejunostomy is
created approximately 100–150 cm distal to the gastro-
jejunostomy to connect the alimentary limb and bilio-
pancreatic (BP) limb (i.e. remnant stomach, native
duodenum and proximal jejunum) (Figure 2b). The small
bowel from this point to the terminal ileum is referred to
as the common channel.
Normal post-operative imaging appearance
Upper GI fluoroscopy using an oral water-soluble
contrast is the first line technique to assess for post-
operative complications. The normal post-operative
fluoroscopic anatomy is presented in Figure 1b. As a
rule of thumb the gastric pouch should be of a size
similar to that of a lower thoracic or lumbar vertebral
body (15–20 ml). This comparison allows simple and
reliable detection of a pouch that is either too large or too
small. Contrast may remain in the distal oesophagus and
gastric pouch for a variable period before passing
through the anastomosis and filling the short blind limb
and alimentary (Roux) limb.
(a) (b) (c)
Figure 1. Normal appearances following Roux-en-Y gastric bypass. (a) Schematic illustration; (b) contrast study; P, gastric pouch;
A, alimentary limb; BL, blind limb; (c) CT image; P, gastric pouch; GR, gastric remnant.
Review article: Imaging in bariatric surgery
The British Journal of Radiology, February 2011 103
CT is not commonly performed in the post-opera-
tive assessment following RYGB, but can be useful
when fluoroscopic examinations are equivocal or for
the evaluation of extraluminal complications such as
intra-abdominal fluid collections. Normal post-operative
findings at CT are demonstrated in Figure 1c and
Figure 2.
Complications
The incidence of anastomotic leak after RYGB is
reported to be in the region of 2–5% [11, 12]. It is an
early complication, usually within the first 10 days
following surgery, and most commonly occurs at the
gastrojejunal anastomosis. It is a potentially life-threaten-
ing complication and requires prompt diagnosis. How-
ever, clinical evaluation is difficult as patients may have
no signs of peritonitis and may present with only fever,
tachycardia and abdominal discomfort, which are
relatively non-specific in the immediate post-operative
period [13]. Fluoroscopy typically shows extravasated
contrast material in the left upper quadrant (Figure 3).
Abdominal drains should be scrutinised closely because
some well-controlled leaks are evident only on the basis
of opacification of the drainage catheter. It should also
be noted that, although not commonly left in situ, the
presence of a nasogastric tube with its tip in the ali-
mentary limb may prevent visualisation of leakage from
the anastomosis.
Abdominal fluid collection and subphrenic abscess
occur in fewer than 2% of all bariatric surgery patients,
but are extremely serious complications with a high
morbidity and mortality [12, 14]. Plain radiographs may
show an air-fluid level in the left upper quadrant,
although this finding can be difficult to interpret because
of air in the remnant stomach. However, CT has a critical
role in the work-up as it will readily demonstrate the
fluid collection. In addition, the presence of air-fluid
levels or contrast material is highly suggestive of
anastomotic leak as the underlying cause.
Anastomotic narrowing at the gastrojejunal anastomo-
sis has a reported incidence ranging from 3% to 9% and
is more common with a circular stapled gastrojejunost-
omy [11, 15]. Clinically, this presents with dysphagia,
post-prandial pain and vomiting [14]. Fluoroscopy
demonstrates narrowing at the gastrojejunal anastomo-
sis, expansion of the gastric pouch and delayed passage
of contrast material into the Roux limb. In the immediate
post-operative period this is usually the result of
anastomotic oedema [16] (Figure 4a). In these cases,
follow-up examinations should show improvement if the
delay is caused by oedema. Persisting pouch distension
on follow-up and air/contrast material levels in the
pouch and oesophagus are suggestive of a stricture
(Figure 4b). Stricture at the jejunojejunal anastomosis is
rare, with an incidence of 0.8% [17]. On fluoroscopy,
contrast material is seen in a distended alimentary limb
(Figure 5). It can also result in distension of the
biliopancreatic limb with air-fluid levels within the
(a) (b)
Figure 2. Normal CT appearances following Roux-en-Y gastric bypass. (a) Antecolic position of alimentary limb; A, alimentary
limb; TC, transverse colon; (b) jejunojejunal anastomosis; arrow shows the anastomosis between alimentary and biliopancreatic
(BP) limbs.
Figure 3. Contrast study demonstrating leak at gastrojeju-
nal anastomosis; arrow indicates leak; P, gastric pouch; A,
alimentary limb.
S Shah, V Shah, A R Ahmed and D M Blunt
104 The British Journal of Radiology, February 2011
gastric remnant. Similar findings can also be seen in the
early post-operative period and secondary to anastomo-
tic oedema, endoluminal haematoma or bolus obstruc-
tion at the jejunojejunal anastomosis.
Small-bowel obstruction is reported in 4–5% of
patients [18]. It is usually caused by internal hernias or
adhesions, although other causes include mesocolic
window stenosis, bezoar formation in the gastric pouch
and intussusception [11, 12]. Compared with open
procedures, the laparoscopic approach has reduced the
prevalence of adhesions but has led to an increase in the
prevalence of internal hernia formation. Internal hernias
often develop through the opening in transverse meso-
colon following retrocolic placement of the roux limb,
and antecolic placement appears to have decreased the
prevalence of internal hernias [18]. The herniated bowel
is usually the Roux limb itself with a varying amount of
additional small-bowel loops [12].
It can be difficult to distinguish small-bowel obstruc-
tion caused by adhesions from that caused by internal
hernia on CT. However, clustering of dilated small-
bowel loops in the left upper quadrant is more
suggestive of internal herniation [19]. In the case of
herniation through the transverse mesocolon, the her-
niated cluster of bowel is located posterior to the
stomach and transverse colon.
Stomal ulceration incidence is in the region of 10%. It is
thought to occur as a result of increased acid production
within the pouch and is, therefore, associated with larger
gastric pouches [20]. Patients usually present with severe
dyspepsia, burning retrosternal pain and vomiting. The
diagnosis is usually made endoscopically; however,
imaging studies may detect complications such as
stricture, perforation and gastrogastic fistula.
Gastrogastric fistula is a connection between the
gastric pouch and remnant and is a rare complication,
with a reported incidence of ,1%. It occurs secondary to
leaks or stomal ulcer perforation [21, 22]. The primary
finding on fluoroscopy is detection of contrast material
in the gastric remnant (Figure 6).
(a) (b)
Figure 4. Contrast studies demonstrating narrowing at gastrojejunal anastomosis. (a) Post-operative oedema: arrow indicates
narrowing at gastrojejunal anastomosis; P, gastric pouch; A, alimentary limb; (b) stricture; arrow indicates stricture at
gastrojejunal anastomosis; P, gastric pouch; A, alimentary limb.
Figure 5. Contrast study demonstrating jejunojejunal stric-
ture; arrow indicates stricture at anastomosis between
alimentary and biliopancreatic limbs; arrowhead indicates
oedema in alimentary limb; A, alimentary limb; CC, common
channel.
Review article: Imaging in bariatric surgery
The British Journal of Radiology, February 2011 105
Adjustable gastric banding
Surgical technique
LAGB is a purely restrictive procedure that has
traditionally been popular in Europe, but is now
increasingly performed in North America; recent data
suggest it is now the most commonly performed
technique worldwide [10]. The surgical technique
involves placing an adjustable silicon band around the
proximal stomach, approximately 2 cm distal to the
gastro-oesophageal junction to partition a small gastric
pouch and create an adjustable stoma into the remainder
of the stomach (Figure 7). The anterior gastric wall is
often sutured over the band to the gastric pouch to
decrease the chances of band slippage. The band is then
connected via tubing to a port placed subcutaneously in
the abdomen. Through percutaneous aspiration or
injection of saline or radio-opaque contrast into the port,
the size of the band is decreased or increased, thereby
adjusting the stomal width [23]. In some units a contrast
swallow study is performed at the same time as the band
fill to objectively determine adequacy of band filling.
Normal post-operative imaging appearance
On fluoroscopic studies (Figure 7b), the gastric pouch
should be relatively symmetric in shape and measure
approximately 3–4 cm in maximum dimension when
distended with contrast material. The stoma diameter
should measure approximately 3–4 mm in diameter,
with prompt emptying of the pouch [24]. In addition, the
adjustable band, catheter and subcutaneous port can all
be visualised. Another factor that should be assessed is
the orientation of the gastric band, which should lie
obliquely. This can be more formally measured using the
phi angle, which is the angle created by intersecting a
line drawn parallel to the spinal column with a line
drawn parallel to the plane of the gastric band on an
anteroposterior projection. Normally this angle should
range from 4˚to 58˚[25].
Figure 6. Contrast study demonstrating gastrogastric fistula;
P, gastric pouch; A, alimentary limb; GR, gastric remnant.
(a) (b)
Figure 7. Normal appearances following laparoscopic adjustable gastric banding. (a) Schematic illustration; (b) contrast study
demonstrating phi angle; P, gastric pouch; arrow shows gastric band.
S Shah, V Shah, A R Ahmed and D M Blunt
106 The British Journal of Radiology, February 2011
Complications
Stomal stenosis and acute concentric pouch dilatation
are the most common complications after LAGB [26],
and present with nocturnal reflux, vomiting and upper
abdominal discomfort. It may be due to iatrogenic over-
filling of the band, post-operative stomal oedema or
blockage of the stoma by food bolus. Typical fluoroscopic
findings include a narrowed or obstructed stoma with
proximal concentric pouch dilatation, delayed passage of
contrast material and oesophageal reflux.
Chronic pouch dilatation incidence is 3–8% [26, 27]. In
contrast to acute pouch dilatation, it occurs in the
presence of a normal stoma and is usually owing to
chronic volume overload of the pouch secondary to
overeating. As the pouch gets larger it allows for further
overeating and further dilatation resulting in a ‘‘mega-
pouch’’ (Figure 8). If left untreated it can result in
oesophageal dysfunction and dilatation and eventually
lead to a mega-oesophagus.
Pouch prolapse, also termed band slippage, is the
superior herniation of the distal stomach wall and may
occur despite adequate initial band placement. Incidence
ranges from 3% to 13% and is decreasing with modifica-
tions to the surgical technique [26–29]. Anterior prolapse
is more common and results in lateral eccentric gastric
pouch enlargement, stomal narrowing and a horizontally
orientated band, with a phi angle of greater than 58˚
(Figure 9) [11, 30]. In posterior prolapse, which is now
uncommon, there is medial eccentric gastric pouch
enlargement and a vertically lying band.
Band misplacement is a technical complication rarely
observed. The band may be misplaced in perigastric fat,
over the gastro-oesophageal junction or the lower part of
stomach, and may result in poor weight loss, dysphagia
or gastric outlet obstruction.
Port- and band-related complications are reported in
0–7% of cases, and include leakage, infection and band
erosion [26]. Leakage can occur from the band, catheter
or access port and should be suspected when there is loss
of eating restriction or insufficient deflation volume.
Causes of leak include trauma to the band balloon or
catheter, or a defective device. Band erosion is usually a
rare and late complication and is diagnosed by the
intraluminal position of the band, with contrast outlining
both inside and outside of the band.
Acute gastric perforation is rare, occurring in ,1% of
cases, and is usually owing to surgical trauma to the
stomach wall [26, 28]. It has an extremely variable clinical
presentation and can lead to life threatening sepsis.
Fluoroscopy and CT may demonstrate leak of contrast
into the left upper quadrant.
Sleeve gastrectomy
Surgical technique
The laparoscopic sleeve gastrectomy (SG) is a rela-
tively new technique and was first performed in 1999
[31]. It was originally proposed as the first part of a two-
stage operation in super-obese patients with a BMI
.60 kg m
-2
or in high-risk patients [32]. However, more
recently its use has become more widespread and it now
accounts for approximately 5% of bariatric procedures
[10]. It is an essentially restrictive intervention performed
by vertically dividing the stomach along the greater
curve, thus removing the fundus and greater curvature
and leaving a thin, banana-shaped gastric pouch of
Figure 8. Contrast study demonstrating a megapouch (MP).
Figure 9. Contrast study demonstrating anterior pouch
prolapse and increased phi angle; P, gastric pouch.
Review article: Imaging in bariatric surgery
The British Journal of Radiology, February 2011 107
approximately 100 ml along the lesser curve (Figure 10).
The size of the sleeve is calibrated using a bougie tube
within the stomach and the procedure reduces the size of
the stomach by about 75%.
Normal post-operative imaging appearance
Upper GI fluoroscopy after SG is the first line study to
detect leaks and other post-operative complications. The
normal post-operative fluoroscopic anatomy is presented
in Figure 10b, demonstrating the thin tubular pouch, the
diameter of which varies according to the size of the
bougie tube used. In the majority of cases contrast passes
freely through the sleeve to the antrum, with a slight
delay at the pyloric valve. However, in some cases, there
can be failure to propel contrast with a hold up in the
proximal sleeve [33]. This is thought to be due to gastric
antral malfunction or ‘‘stunning’’ in the early post-
operative period, but usually settles with time and the
aid of a prokinetic agent. A linear streak of contrast may
be seen within non-excised fundus, which may be
mistaken for an extraluminal leak (Figure 11).
Complications
Gastric dilatation is one of the primary drawbacks of
this procedure, and reoperations are required in up to
4.5% of cases [31]. This presents clinically as inadequate
weight loss or weight regain. Fluoroscopy demonstrates
increased diameter of the sleeve, with loss of the normal
tubular appearance.
Gastric leak and abdominal collections as a result of
disruption of the staple line are a potential concern
following SG because of the significant gastric resection
and long staple line, although the literature suggests a
low incidence of approximately 0.9% [31]. The com-
monest site of leak is from the proximal stomach at the
angle of His [34]. Fluoroscopy demonstrates extravasa-
tion of contrast material into the left upper quadrant
(Figure 12a). Intra-abdominal abscess is a potential
sequelae (incidence 0.1%) and may be detected on plain
radiography as an air-fluid level in the left upper
quadrant as there is no remnant stomach. However, CT
is the imaging modality of choice in cases where this is
suspected (Figure 12b).
SG is thought to predispose the patient to post-
operative reflux symptoms because the gastric resection
adversely affects the angle of His. Studies have demon-
strated incidences of up to 21% at 1 year, reducing to 3%
at the 3 year follow-up [35]. Reflux of contrast into the
oesophagus can be readily demonstrated on fluoroscopy,
(a) (b) (c)
Figure 10. Normal appearances following sleeve gastrectomy. (a) Schematic illustration; (b) contrast study; S, gastric sleeve;
(c) CT image; S, gastric sleeve; arrow shows gastric suture line.
Figure 11. Contrast study demonstrating a pitfall in imaging
following sleeve gastrectomy; S, gastric sleeve; arrow indi-
cates intraluminal contrast within fundus mimicking a leak.
S Shah, V Shah, A R Ahmed and D M Blunt
108 The British Journal of Radiology, February 2011
although in the early post-operative period, this may
occur secondary to gastric antral dysfunction as outlined
above.
As the procedure is relatively recent, long-term follow-
up studies are relatively scarce. Other reported compli-
cations include stricture (0.7%), particularly at the
incisura from intra-operative stapling error. There is
also evidence of both delayed and accelerated gastric
emptying following SG. Indeed, the latter is hypothe-
sised to play a central role in the beneficial metabolic
effects seen following surgery [36].
Other techniques
Vertical-banded gastroplasty
This is an older, purely restrictive procedure and its use
has decreased significantly with the popularity of the
RYGB, the advent of laparoscopic adjustable gastric
banding and problems with long-term weight loss [37].
The technique involves vertically partitioning the stomach
to create a small gastric pouch based on the lesser
curvature of the stomach. Using a circular stapler, the
anterior and posterior walls of the stomach are then
stapled together and an incision is made through the
excluded gastric walls to create a circular window,
through which a polypropylene mesh or band is placed
and wrapped around the stomach, creating a small
proximal gastric pouch and a small stoma into the
remainder of the stomach. Imaging is important to help
bariatric surgeons plan revisional surgery.
Jejunoileal bypass
Created by Kremen et al in 1954, the jejunoileal bypass
(JIB) was the original bariatric surgical procedure [38].
Today, the JIB has long since been abandoned because of
the severe malnutritional state and the resultant side-
effects [39]. The general procedure involves creating an
end-to-side jejunoileostomy with a short jejunal limb
approximately 35 cm long anastomosed to the terminal
ileum. Despite the fact that JIB is no longer used to treat
patients who underwent this procedure knowledge of
the procedure is important for radiological imaging.
Role of interventional radiology
One of the most frequently requested interventional
procedures is ultrasound or fluoroscopically guided
percutaneous access to the port for LAGB adjustment,
which cannot be accessed clinically owing to excess
adipose tissue. Indeed, in some centres these are
routinely performed by radiologists. Operators should
be aware that a specialist needle (Huber) should be used
to access the port. This is a non-cutting needle allowing
puncture of the port without damaging the membrane.
Several complications in bariatric-surgery patients can
also be successfully managed with interventional radi-
ology techniques. Indeed, in many cases, image-guided
percutaneous procedures can obviate the need for
emergency surgical exploration, and commonly per-
formed techniques include aspiration and drainage of
abdominal fluid collections. Other techniques that may
be required include imaging-guided placement of jejunal
feeding tubes in cases of gastrojejunal complications in
RYGB, and imaging-guided gastrostomy of the gastric
remnant for temporary decompression in cases of BP
limb distension secondary to obstruction at the jejunoje-
junostomy [40]. Although most often performed via
endoscopy, stenosis at the gastrojejunal anastomosis can
also be dilated with the aid of fluoroscopic guidance [41].
In addition, percutaneous transhepatic techniques can be
used in the management of biliary complications such as
choledocholithiasis in RYGB patients, as conventional
endoscopic access to the biliary tree is limited in this
group [42].
Conclusion
Bariatric surgery is increasingly performed to control
morbid obesity. The imaging of this group of pa-
tients following surgery is a vital component of their
(a) (b)
Figure 12. Post-operative leak from gastric suture line following sleeve gastrectomy. (a) Contrast study; arrow indicates leak
from gastric suture line; S, gastric sleeve; (b) CT; S, gastric sleeve; arrow indicates fluid collection in left upper quadrant.
Review article: Imaging in bariatric surgery
The British Journal of Radiology, February 2011 109
management and presents unique and varied challenges.
We have described the issues faced when setting up such
an imaging service and have presented an overview of
the most frequently performed surgical procedures, the
normal post-operative imaging findings and the details
and appearances of common complications.
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