Obesity Surgery, 14, 861-865 Concept The Duodenal Switch as an Increasing and Highly Effective Operation for Morbid Obesity Robert A. Rabkin, MD, FACS Pacific Laparoscopy, San Francisco, CA, USA Delivered by Ingenta to Dr. Rabkin (cidIntroduction 44010184) the excess weight must exceed the risks of surgery IP: 67.118.237.210 and anesthesia. It is interesting to note that pub- 2004..08..11..19..27.. lished series show significant increases in the rela- “Morbid Obesity” (ICD 278.01 / BMI >40) is an tive risk associated with obesity at a BMI of 27 entity distinct from “ o b e s i t y ” , the latter term kg/m2, and exponential increases at a BMI of 32 encompassing the broad ra n ge of ove r we i g h t . kg/m2 (the highest bracket reported)8,9 – well below Available treatment modalities as well as outcomes the 35 to 40 kg/m2 often considered minimum for differ substantially over the spectrum of higher surgical intervention. BMI. Representative data for behavior modifica- tion, diet and exercise show at best an average weight loss of 4-7 kg at 2 years, with decreasing benefit in the longer term. 1-3 Categorization of Bariatric Operations The reported maximum of 7 kg is hardly signifi- cant for a morbidly obese individual who might be 1. Purely Malabsorptive Procedures carrying an excess weight 45-75 kg or more. Those morbidly obese patients who do respond to non-sur- The most well-known and widely used purely mal- gical weight loss programs, generally fail to main- absorptive procedure, jejuno-ileal bypass, involved tain the weight loss, with recidivism rates exceeding bypassing all but 45 cm of small bowel.10 It was 95%.4 Behavior modification, diet and exercise have as s o c i a ted with a mortality up to 8% from hepa tic and been found to be ineffective on an intermediate and renal fai l u r e, and has largel y been aba n d o n e d .11 - 1 4 long-term basis for treatment of obesity, particularly morbid obesity. Regain of the lost weight is the rule, 2. Purely Restrictive Operations and more than the initial weight lost is commonly 15 regained.5,6 Laparoscopic adjustable gastric banding and verti- 16 Surgery is the only modality proven to be effec- cal banded gastroplasty are purely restrictive pro- tive in the treatment of morbid obesity;7 however, cedures. As originally developed, the Roux-en-Y surgical treatment entails known finite risks influ- gastric bypass (RYGBP) is also primarily restric- 17 enced by clinical factors. To achieve a beneficial net tive, as weight loss results from constructing a reduction in morbidity and mortality, the risks from very small (15-30 cc) proximal gastric pouch to limit the capacity of oral intake.18 RYGBPs reliance on restriction alone has yielded inadequate long- Presented at the California Technology Assessment Forum, sponsored by Blue Shield of California Foundation, February 11, term maintenance of weight loss in many surgeons’ 2004. ex p e ri e n c e. A c c o rd i n g ly, s u rgeons who offe r Reprint requests to:Robert A.Rabkin, MD, FACS, 2250 Hayes Street, 3rd Floor, San Francisco, CA 94117, USA. Fax: 415-668- RYGBP operations have more recently included 2010;e-mail:[email protected] variable amounts of small-bowel bypass, and revi- © FD-Communications Inc. Obesity Surgery, 14, 2004 861 Robert A. Rabkin sionary surgery for RYGBP failure may include en-Y construction to merge biliopancreatic outflow lengthening of the bypassed limb.19-21 The latter pro- with the food stream. The quality of malabsorption cedures may be termed “distal” Roux-en-Y gastric differs among the procedures based on differing bypass (DRYGBP). lengths of the various Roux limbs. Most important, only the DS preserves the pylorus and thereby 3. Hybrid Procedures affords normal gastric functioning. The DS does not rely on and is free of dumping, excess gastritis, and Th ree commonly perfo rmed operations wh i ch marginal ulceration with its frequently associated incorporate both restriction and malabsorption may microscopic bleeding and secondary anemia. be classified as “hybrid”: Distal Roux-en-y gastric bypass (DRY G B P ) , b i l i o p a n c re atic dive rs i o n (BPD), and duodenal switch (DS). • DRYGBP is constructed similar to RYGBP, with Efficacy of DS for Morbid Obesity a shorter common limb and extended length of Delivered by Ingentabypassed to small bowel. Studies of RYGBP report an average excess weight Dr. Rabkin (cid 44010184)• BPD was developed in the 1970s by Nicola loss in the 65% to 80% ra n ge.2 6 - 2 9 H oweve r, IP: 67.118.237.210 22 2004..08..11..19..27..Scopinaro of Genoa, Italy. Specific lengths of RYGBP is not standardized among facilities, and bypassed small bowel differ between BPD and configuration can differ even among surgeons at the DRYGBP. In BPD, the unused distal portion of same fa c i l i t y. Constructed via lap a ro t o my or the stomach is re s e c t e d, wh e reas in the l ap a ro s c o py, the size and confi g u ration of the DRYGBP the distal stomach is stapled off but RYGBP gastric pouch can vary significantly; small left in the abdomen. Food ingested traverses a intestinal limb lengths and limb positioning also similar route in DRYGBP and BPD. may differ. Technical variations include a prosthetic • The operation known as duodenal switch (DS) ring made of silicone rubber, polypropylene or was developed in 1988 by Doug Hess of Gore-tex® added to the underlying RYGBP struc- Bowling Green, Ohio,23 and was first published t u re.3 0 L o n g - t e rm outcomes of RYGBP diffe r by Marceau et al24 in 1993. Hess incorporated widely because of these variations, confounding an three main components into the DS: 1) Vertical accurate “apples to apples” comparison. Significant gastrectomy with excision of the greater curva- weight regain after RYGBP in some series can occur ture significantly reduces gastric volume and within 3 to 5 years.31 Nonetheless, RYGBP offers thus provides restriction. 2) Division of the significant resolution of co-morbidities, including duodenum between the pyloric valve and the non-insulin-dependent diabetes mellitus, hyperten- sphincter of Oddi allows for a normally func- sion, and sleep apnea.32 tioning but smaller capacity stomach. Food In contrast, performance of the DS is more uni- empties into the small intestine under control of form among DS surgeons. The authors’ published normal pyloric innervation and relaxation. 3) series employing the laparoscopic D/S (LapDS) Bypass of proximal small bowel produces mal- demonstrated an average of 91% excess weight loss absorption and was derived after experience at 2 years.25 Published 10-year data with 93% fol- with the BPD. The first laparoscopic technique low-up demonstrate sustained average loss of 76% for performing DS was developed in 1999 in the of excess weight.33 This applies as well to the super- authors’ facility in San Francisco.25 obese (BMI >50), while the RYGBP is documented Terminology has unfortunately not helped to clar- to be less effective initially and longer term at that ify the anatomical or functional distinctions among level. Multiple reports from others utilizing either DRYGBP, BPD and DS. Intake restriction is present conventional laparotomy or a laparoscopic approach in all three operations, based on the reduction in to DS have confirmed Hess’ long-term weight loss gastric volume, with BPD having the largest resid- data,34-37 although weight regain after 10 years is ual capacity (240 cc) and DRYGBP the smallest rep o rted to be most pronounced in the super- (15-30 cc). DS capacity is intermediate at approxi- obese.38 Both short-term and long-term weight loss mately 120 cc. All three procedures use the Roux- following DS exceeds that of any other operation, 862 Obesity Surgery, 14, 2004 Duodenal Switch Operation with documented benefit for the metabolic syn- Open Laparotomy vs Laparoscopy drome,39 pregnancy40 and proportionate resolution of co-morbidities comparable to the RYGBP. Long conventional abdominal incisions have been superseded in many centers by small incisions, made possible by technical advances in video equip- Increase in Surgeons Performing DS ment and surgical instrumentation.41,42 Patient pref- erence for laparoscopic approaches is based on con- sistently decreased perioperative discomfort, short- DS usage continues to expand, based on patient ened hospital stay and smaller scars. An important demand and growing awareness of the advantages principle of laparoscopic surgery in that the proce- of established hybrid procedures. Currently RYGBP dure performed within the abdomen should remain is the most widely used bariatric operation in the identical whether conventional lap a ro t o my or U.S.A.; however, the number of centers offering the laparoscopy is used. A principle enunciated at the Delivered by IngentaDS is togrowing rap i d ly. The ASBS 2002 time that laparoscopy was adapted to Nissen fundo- Dr. Rabkin (cidMembership 44010184) Roster listed approximately 50 sur- plication – that only the access route will differ – IP: 67.118.237.210geons who offer the DS. The ASBS 2003 has remained a guiding tenet. Other than measures 2004..08..11..19..27..Membership Roster listed 104 surgeons offering the specific to the wound, intermediate and long-term DS. Most bariatric surgeons already have substan- indicators should be the same when comparing tial experience with RYGBP before beginning to laparoscopic with open laparotomy groups.