Bariatric surgery,
since its origin,
had improved and nowadays has generally a general low risk of post-procedural complications; patients,
on average,
are discharged from the hospital 2-3 days after the intervention.
Despite this,
in some patients,
expecially in those with comorbidity and the superobese (those with BMI > 40 kg/m2),
the early complication rate might be higher,
extending recovery times and lenghtening the hospedalization times.
In other patients,
the onset of late complications, related to surgical technique,
eating habits and other factors,
can be observed.
In our centre,
the most frequent bariatric surgery interventions are:
Laparoscopic adjustable gastric banding (LAGB) placement.
The LAGB was approved by the United States Food and Drug Administration (FDA) in June 2001,
for patients who have failed trials of medical weight loss,
and who have a body mass index (BMI) 40 kg/m2,
or a BMI 35 kg/m2 with one or more severe comorbidities,
or weight 100 pounds (about 45 kilograms) above their estimated ideal body weight [1].
Once inserted, the device,
made of a gastric band and a subcutaneous port,
connected by a tube,
creates a restricted gastric opening and a small gastric pouch that limits food consumption and promotes early satiety.
Normally,
the band is positioned about 2-3 cm from the gastro-oesophageal junction (fig.
1).
Fig. 1: Correctly positioned LAGB system; in the image on the left are recognizable the gastric band in the epigastric region and the subcutaneous port against the left iliac fossa. The image on the right shows a frame of the control dynamic x-ray examination in the same patient with prompt and complete contrast medium transit through the neostoma.
References: U.O.C. Radiologia Universitaria, Università degli Studi di Padova, Azienda Ospedaliera di Padova - Padova/IT
Laparoscopic sleeve gastrectomy (LSG) is a restrictive bariatric procedure reducing gastric capacity as a primary mechanism of action.
The size of the gastric remnant is reportedly the key factor for success of the procedure [2-5]. Weight loss after LSG is thought to result from both restrictive and hormonal mechanisms [6-7].
In our centre,
it is currently the most widely practiced intervention; our surgeons use a five-trocar laparoscopic technique.
The operation starts with the dissection of the gastric greater curvature.
LSG is modelled on a 40 Fr oro-gastric bougie,
using sequential firings of laparoscopic linear stapler applied from the proximal antrum to the angle of His.
An intraoperative leak test is always performed with methylene blue.
A peri-gastric drain is always positioned.
At discharge,
normal appearance of gastric remnant is as in fig.
2.
Fig. 2: Normal appearance of the gastric remnant after laparoscopic sleeve gastrectomy (LSG) during a contrast radiography of the upper gastrointestinal tract; frontal (a) and left oblique view (b).
References: U.O.C. Radiologia Universitaria, Università degli Studi di Padova, Azienda Ospedaliera di Padova - Padova/IT
Roux-en-Y gastric bypass (RYGB) entails the use of a stapler-cutter device to create a staple line that partitions the stomach into a small fundal component (gastric pouch) and a much larger excluded component.
The jejunum is then divided 25–50 cm distal to the ligament of Treitz,
and the distal limb (Roux or efferent limb) is brought up and anastomosed to the gastric pouch by a gastrojejunal anastomosis,
creating a short,
blind-ending jejunal stump. Finally,
the proximal limb of the divided jejunum (afferent limb) is anastomosed to the small bowel 75–150 cm distal to the gastrojejunostomy to create a common channel that continues into the ileum [8].
There are some variations,
such as the mini gastric bypass,
similar to classic one but consisting in only one anastomosis between stomach and small bowel.
The normal appearance of the digestive tract after RYGB intervention for bariatric purpose is as in fig.
3.
Fig. 3: Normal postoperative findings after RYGB in frontal (left) and left lateral view (right). The frames show a prompt and complete passage of the contrast medium through the gastric pouch, the gastro-jejunal anastomosis and the afferent jejunal limb.
References: U.O.C. Radiologia Universitaria, Università degli Studi di Padova, Azienda Ospedaliera di Padova - Padova/IT
A well done hydrosoluble contrast medium or barium meal is very often useful to confirm the clinical suspicion of a complication and to interpret patients' symptoms.
In our centre,
an UGS with hydrosoluble contrast medium (Gastrografin 370 mg I/ml,
diatrizoate meglumine + diatrizpate sodium) is always performed at postoperative day 1 in order to rule out early complications; then,
if patients complaint symptoms at any time after discharge,
we perform an examination with hydrosoluble medium or administering an oral suspension obtained with barium diluted in 100 ml of water (Prontobario H.D.,
98.45g of barium sulfate),
depending from the clinical suspicion.
Tip: we suggest to perform a preliminary plain film to identify anatomical and iatrogenic structures (gastric band,
port,
connection tube,
surgical staples,
drainage tubes...),
subdiaphragmatic free gas,
air-fluid levels or obstucion signs,
and then perform dynamic series (1 frame per second) in more projections.
Tip: patients should stand with their back against the fluoroscopy table with the contrast in a glass on their left hand,
away from the abdomen and image intensifier and have to carefully listen to radiologist directions,
in order to obtain best quality images.