Table 1 Bariatric surgeries: mainly types and descriptions

Adjustable gastric band (AGB)

Involves an inflatable band that is placed around the upper portion of the stomach, creating a small stomach pouch above the band, and the rest of the stomach below the band. The size of the stomach opening can be adjusted by filling the inflatable band with sterile saline, which is injected through a port placed under the skin [12].

Sleeve gastrectomy (SG)

Also known as vertical gastrectomy. The procedure removes the gastric fundus and body, leaving a gastric tube along the lesser curve [13].

Duodenojejunal bypass (DJB)

The pylorus is preserved and the length of the biliopancreatic limb is 70 cm from the ligament of Treitz. The Roux limb is 100 cm long. The duodenum and jejunum are bypassed for the nutrient flow. This technique is presently an experimental procedure [9, 14, 15].

Biliopancreatic diversion (BPD)

This technique consist in a reduction of gastric pouch (70±10 mL), an alimentary limb composed of 400 cm, a common limb of 100 cm, and a biliopancreatic limb, the remainder of the small intestine [16].

Biliopancreatic diversion with duodenal switch (BPD-DS)

Adaptation from the biliopancreatic diversion. is a procedure with two components. First, a smaller, tubular stomach pouch is created by removing 70% of portion of the stomach, very similar to the sleeve gastrectomy. Next, a large portion of the small intestine is bypassed [12, 17–19].

Roux-en-Y gastric bypass (RYGB)

Consists in the reduction of the gastric food reservoir (to a capacity of 30 to 50 mL) and excludes the passage of nutrients through the remaining stomach, duodenum, and proximal jejunum, with an isolated Y-shaped jejunal loop being anastomosed to the small stomach pouch [20, 21].