**3.1. Antecolic isoperistaltic RY reconstruction**

A 12-mm trocar is inserted through the umbilical region by the open procedure, and then CO<sup>2</sup> pneumoperitoneum is established. A 12-mm trocar is introduced into the left pre-axillary line 1 cm below the costal margin. A 5-mm trocar is inserted into the left midclavicular line 2 cm above the umbilicus. The second 5-mm trocar is inserted into the right pre-axillary line 1 cm below the costal margin. Another 12-mm trocar is placed by the camera assistant between the patient's legs.

Laparoscopic mobilization of the stomach and lymph node dissection are carried out in a conventional procedure. The duodenum is divided distal to the pylorus with a 60-mm ELS; then, the stomach is divided with two ELSs. The specimen is removed through an extended 4-cm incision in the umbilical port. Following re-establishment of the pneumoperitoneum, the jejunum 20 cm distal to the ligament of Treitz is prepared for Roux limb, and the mesentery of this jejunum is divided for a distance of 8 cm. The prepared jejunum is then divided with an ELS to ensure a gastrojejunostomy without tension. A side-side jejunojejunostomy is fashioned 25 cm distal to the planed gastrojejunostomy using an ELS under direct vision through the umbilical incision. The jejunojejunostomy defect is closed with absorbable suture in an intermittent fashion. Following re-pneumoperitoneum, the jejunal limb is brought to the gastric remnant through an antecolic route. A right-oriented Roux limb is created such that the cut end of the Roux limb faces the greater curvature of remnant stomach. The jejunal limb is anastomosed to the greater curvature of remnant stomach side to side with an ELS; then, the site of entry hole is closed using an absorbable barbed suture. The duodenal stump is embedded with seromuscular suture and then fixed with the alimentary limb on the duodenal stump in a proper radian.

## **3.2. Antecolic antiperistaltic RY reconstruction**

The duodenum and stomach are divided distal to the pylorus with three 60-mm ELSs. The specimen is removed through an extended 4-cm incision in the umbilical port. After re-pneumoperitoneum, the proximal jejunum is identified and divided 25 cm distal to the Treitz ligament, and the mesentery of the jejunum is divided. The jejunum is divided with a 60-mm ELS. Small holes are made at the tips of linear stapler of the greater curvature side of the remnant stomach and distal side of jejunal stump. The gastrojejunostomy is performed between the posterior wall of remnant stomach and antimesenteric border of the distal jejunum with a 60-mm ELS. The common entry hole is closed with a 60-mm ELS. The jejunojejunostomy is performed through an umbilical minilaparotomy with a 60-mm ELS and hand-sewn suture.
