Evolution of the GaBP Ringä (Fobi Ring)
Mal Fobi MD, FACS, FASMBS
Dr. Edward Mason after observing the weight loss from the gastric bypass (GBP) operation, attributed the weight loss to the restrictive capacity of the gastric pouch. This observation led him to introduce a restrictive operation in 1971, the partially transected horizontal gastroplasty with a proximal pouch as small as that of the GBP operation.(1) This was a less invasive operation with less surgical morbidity and no malabsorption or long-term complications as with the GBP. The initial short-term weight loss appeared to be as good as what had been observed with the GBP. This gave birth to various gastroplasty operations from 1971 – 1977 when it became very apparent that the channel between the pouch and the rest of the stomach stretched progressively after the first six months and the operation lost its restrictiveness and therefore its effectiveness.(2) This loss of restrictiveness gave birth to the concept of reinforcement of the gastroplasty stoma, starting with Gomez using a plastic mesh to Kroyer using a Marlex mesh that was ultimately popularized by Dr. Mason in the vertical banded gastroplasty (VBG).(3) Fobi used the VBG starting in 1981 and then switched to the silastic ring gastroplasty (SRVG) in 1983 influenced by the report from Eckhout and Willbanks who had popularized the use of the silastic ring to band the gastroplasty as described by Laws (3). It was about this same time that there were increasing reports of the failures of the gastric bypass operations due to stretching of the pouch and stoma. To address this failure of the gastric bypass due to dilatation of the pouch and stoma, Salmon used a modified gastric bypass operation with a banded gastroplasty within a gastric bypass pouch and Linner used a banded gastric bypass with the silastic ring around the gastroenterostomy.(4) Both modifications were first presented at the annual symposium on surgical treatment of obesity in 1984, a meeting Fobi held in Los Angeles yearly from 1981 to 1992. Fobi tried the Linner modification in 1984 but had almost 100% ring erosion in the first 27 patients and thus abandoned the technique. By 1985 there were a significant number of patients with intact surgical anatomy after either the VBG or SRVG that were revised to GBP as it became apparent that the GBP operation, even with its shortcomings was a better operation for weight loss and weight loss maintenance than any of the gastroplasty operations.
Forty three patients had a revision from a VBG to a GBP in 1985 and 1986 at the Center for Surgical Treatment of Obesity in Los Angeles, California with the gastro-enterostomy made below the level of the Marlex mesh band because it was not safe or difficult to remove the mesh. In 1989 when the weight loss outcomes were evaluated in this subset of patients as compared to the GBP, VBG and SRVG patients these patients lost more weight and had the best weight loss maintenance. These findings were presented at the ASBS meeting that was held in June 1989 in Toronto, Canada. Ilan Charuzi from Israel presented similar results at that meeting from revising VBG to GBP.
This observation resulted in Fobi’s re-introduction of the banded gastric bypass (BGBP) as a primary operation but this time the silastic ring was placed not at the gastro-enterostomy as described by Linner but at least 2cm above the gastroenterostomy.(5) Surgeons from around the world reported superior results with a banded gastric bypass.(6) Howard et al from Albany State University independently carried out a prospective clinical trial of banded gastric bypass using a marlex mesh as a primary operation versus a vertical banded gastroplasty starting in 1986. The reported weight loss outcomes after 9 years of follow up were published in Obesity Surgeryin 1995 and corroborated the superiority of the banded gastric bypass operation over the other GBP modifications.(7) Generally, surgeons performing the banded gastric bypass fashioned their own devices to band the pouch. Fobi used a fashioned silastic ring to band the pouch for his procedures from 1989 to 2002, when he recognized the need for a prefabricated ring that could automatically lock and easily be implanted laparoscopically. This gave birth to the Auto-Lock GaBP Ringä that is now popularly called the Fobi Ring. It is a patented, pre-fabricated, calibrated and sterilized silicone coated implantable device, available in various sizes, that is designed specifically to control the reservoir capacity in gastric bypass, gastroplasty and sleeve gastrectomy operations.(8,9) It currently has a CE Mark for international use and an investigational device exemption classification in the USA where FDA approval is expected in the second quarter of 2013 when the one year follow up reports from the clinical trials are presented.
Figure 1 – The GaBP Ring™ is a prefabricated, sterilized ring designed to band the proximal pouch of the sleeve gastrectomy and gastric bypass.
Writing in Obesity Surgery in 1994, the father of the Roux-en-Y gastric Bypass, Dr. Edward Mason, categorically stated that “as Roux-en-Y Gastric Bypass is primarily a restriction operation, just as with VBG, it is important that the outlet of the pouch does not stretch.”(10)
- Mason EE, Ito C. Gastric bypass. Ann. Surg., 170:329-339 (1969).
- Mason EE. Surgical Management of Morbid Obesity, Marcel Dekker Inc, New York 1987 page 49-69
- Gomez CA. Gastroplasty in the surgical treatment of morbid obesity. Am J. Clin. Nutr., 33(2suppl):406 (1980).
- Laws HJ.. Standardized gastroplasty orifice. Am J. Surg., 141:393 (1981).
- Fobi M.A., Lee H., Holness R., Cabinda D., Gastric bypass operation for obesity. World J Surg. 22:925-935 (1998).
- O’Brien P.E., McPhail T., Chaston T.B., et al. Systematic review of medium-term weight loss after bariatric operations. Obes Surg. 16:1032–40 (2006).
- Howard L., Malone M., Michalek A., et al. Gastric bypass and vertical banded gastroplasty: a prospective randomized comparison and 5-year follow-up. Obes Surg. 5: 55–60 (1995).
- Fobi M.A., Lee H., Felahy B., et al. Fifty Consecutive Patients with the GaBP Ring System Used in the Banded Gastric Bypass Operation for Obesity with Follow Up of at Least 1 Year. SOARD. 1:569-572 (2005).
- Mason EE. Obes Surg. 4:66-72 (1994).
الكاتب : Mal Fobi MD, FACS, FASMBS