Silastic ring gastric bypass: a comparison of two ring sizes: a preliminary report

The silastic ring (vertical) gastric bypass (SRGB) was introduced by Fobi in 1989, in an effort to combine the advantages of the Roux-en-Y gastric bypass with those of the VBG, while avoiding disadvantages of each. We remain unsure of the ideal ring size.

Sixty-four patients having SRGB between June 1990 and September 1994 had a 5.5 cm ring placed and 24 patients operated between October 1994 and September 1995 had a 6.0 cm ring placed. Weight loss and quality of eating data is compared 12 months after surgery.

Median preoperative per cent excess weight was 113 (range 76-209) in the 5.5 cm group and 106 (range 79-196) in the 6.0 cm group. Weight loss was equivalent at 12 months, with median percent excess weight of 33 (range 8-109) and 27 (range 6-81) in the two groups respectively. Quality of eating data appears better in those with the larger ring size. Nine patients with a 5.5 cm ring have subsequently had their ring removed to improve their quality of eating and a further six may require this in the future. One patient with a 6.0 cm ring has had the ring removed and two others may require this be done.

An SRGB with a 6.0 cm ring achieves equivalent weight loss to one with a 5.5 cm ring, but with better quality of eating, and less prospect of requiring ring removal. However, there remains a small proportion of patients in whom a 6.0 cm ring is poorly tolerated. For this reason a 6.5 cm ring should be tested.