Jacques Himpens, MD, PhD is a professor of surgery associated with the Université Libre de Bruxelles and chief of bariatric surgery at the CHIREC Delta hospital, Brussels, Belgium. Born February 15, 1953, he graduated as MD cum laude from the Katholieke Universiteit Leuven, Belgium in 1977 and trained at the surgery department of the Leuven university hospitals (1977-1982). After passing the Visa Qualifying Examination to qualify for medical practice in the US, he benefited from additional training with Dr Louis Del Guercio at the New York Medical College and affiliated hospitals from 1982 through 1984. While in New York he was involved with research on hypovolemic shock, which in 1984 resulted in the design of an indwelling oncometer catheter that obtained a worldwide patent. In the mean time he passed his surgical boards with the Belgian public health office in 1984. After 8 years in private practice in Gent, Belgium he joined the “Université Libre de Bruxelles” in 1992 and became an attending surgeon in the gastro-intestinal department at the St Pierre University Hospital Brussels under leadership of Guy-Bernard Cadière. On March 3, 1997 he performed the world’s first “robotic” procedure, which consisted of a laparoscopic cholecystectomy with the Intuitive Surgery “Mona” prototype. Later on, he remained personally actively involved with the first developments of “robotic” surgery and performed numerous “robotic” procedures such as Nissen fundoplication, lysis of adhesions, lumbar sympathectomy, inguinal hernia repair, intrarectal procedures and some adjustable band gatroplasties (AGB). The latter procedures were in line with the developments at the department since Himpens had assisted professor Cadière when he performed the world’s first laparoscopic adjustable band gastroplasty (AGB) in October 1992. Starting in 1993, Dr Himpens combined his academic career with a private practice at the St Blasius Hospital at Dendermonde, Belgium. He founded the bariatric unit at the St Blasius Hospital in 1999 and in 2004 the bariatric department at the Edith Cavell Hospitals (CHIREC) at Brussels, Belgium. After having personally performed some 1000 AGB procedures he performed the first laparoscopic gastric bypass in Belgium in 1999 and the first laparoscopic sleeve gastrectomy, followed by the first biliopancreatic diversion with duodenal switch, both in 2001. Starting 2003, he and his team at the St Blasius Hospital performed close to 2000 laparoscopic bariatric procedures a year, including all “classic” bariatric procedures according to an empirical algorithm he designed and published. By 2018 he had performed over 15000 laparoscopic obesity procedures, many of them revisional. In February 2013 he obtained his doctor’s degree at the University of Maastricht, the Netherlands, under the guidance of professor Jan-Willem Greve with a thesis “ Adjustable Gastric Band, Sleeve Gastrectomy and Roux-en-Y gastric bypass by laparoscopy: long term outcomes and laparoscopic strategies in case of failure”. In addition to his appointment with the Université Libre de Bruxelles he is currently part of the faculty at the Institut pour la Recherché sur les Cancers Digestifs (IRCAD), at Strasbourg, France, where he teaches laparoscopic bariatric surgery. Over the last years his teaching commitment comprised the training of numerous residents and fellows –many from abroad- whom he successfully encouraged to publish in distinguished journals. Recently, in cooperation with professor Francois Pattou he got involved with the research on Natural Orifice Endolumenal Strategy (NOTES) at the university of Lille, France and the use of this technique for the treatment of type 2 diabetes mellitus. To this purpose he developed and co-patented an incisionless anastomotic tool that is manufactured by the Cousin ° company (Wervik, France) and is presently being evaluated in animal tests. He is president of the International Federation for Obesity and Metabolic Diseases (IFSO) 2017-2018. He is a co-opted member of the Belgian society for Obesity and Metabolic Diseases (BeSoms). Because of his achievements in bariatric surgery in 2015 he was awarded the title of honorary fellow of the American Society for Metabolic and Bariatric Surgery (ASMBS). He is an honorary member of the French and the Spanish Society of Obesity Surgery (SOFFCO and SECO, respectively) and will receive the fellowship title of the American College of Surgeons (FACS) in October, 2018. He published over 160 articles in peer reviewed medical journals, authored a substantial number of chapters in surgical books and more specifically in books on bariatric surgery and co-edited four books on bariatric surgery. He is co-editor for the “Obesity Surgery” journal and is a member of the editorial board of “SOARD”.
Selected publications from PubMed
The BARIAlink Global Collaborative Platform: Just Another Educative Tool or a Pioneering Evolution in the Treatment of Metabolic and Obesity-Related Disease?
Wafa A, Himpens J, Torres A, Parmar C, Dillemans B
Obes Facts. 2026 Jul 24;:1 doi: 10.1159/ofa/adzag001.
Global Variability in Children and Adolescent Metabolic Bariatric Surgery Guidelines: A Worldwide IFSO Survey.
Pujol-Rafols J, Felsenreich DM, Carmona-Maurici J, Prager G, Cohen RV, Zundel N, Parmar C, Alqahtani A, Copaescu C, Omelanczuk P, Himpens J, Olbers T, Pouwels S, Shikora SA, Di Lorenzo N, de Luca M, Weiner S, Mazzarella M, D'Arco S, Angrisani L, Uyanik O, Pardina E, Balibrea JM
Obes Surg. 2026 Jul;36(7):3456-3467 doi: 10.1007/s11695-026-08743-w.
Conversion to One-Anastomosis Gastric Bypass versus Roux-en-Y Gastric Bypass for Treatment of Gastroesophageal Reflux Disease after Sleeve Gastrectomy: A Systematic Review and Meta-analysis.
Noel P, Layani L, Parmar C, Himpens J
Obes Surg. 2026 May;36(5):2597-2610 doi: 10.1007/s11695-026-08608-2.
Primary and Revisional One Anastomosis Gastric Bypass: A Systematic Review and GRADE-Based IFSO Position Statement.
De Luca M, Belluzzi A, Monami M, Angrisani L, Carbajo MA, Di Lorenzo N, Himpens J, Kermansaravi M, Merola G, Navarra G, Nimeri A, Petry TBZ, Piatto G, Shikora S, Cohen RV
Obes Surg. 2026 Jan;36(1):253-304 doi: 10.1007/s11695-025-08278-6.
Meta-analysis of randomized controlled trials for the development of the International Federation for Surgery of Obesity and Metabolic Disorders-European Chapter (IFSO-EC) guidelines on multimodal strategies for the surgical treatment of obesity.
De Luca M, Belluzzi A, Angrisani L, Bandini G, Becattini B, Bueter M, Carrano FM, Chiappetta S, Cohen RV, Copaescu C, Di Lorenzo N, Emous M, Felsenreich DM, Fried M, Himpens J, Iannelli A, Navarra G, Nienhuijs S, Olmi S, Parmar C, Prager G, Pujol-Rafols J, Ragghianti B, Ribeiro R, Ruiz-Úcar E, Sakran N, Salminen P, Scoccimarro D, Stenberg E, Stier C, Taskin HE, Puy RV, Monami M, Panel for the IFSO‐EC on the Surgical Treatment of Obesity Using Multimodal Strategies
Diabetes Obes Metab. 2025 Jun;27(6):3347-3356 doi: 10.1111/dom.16352.
Surgery remains the most effective approach in the fight against the ever-increasing disease of obesity. Different approaches are possible. Surgical procedures that reduce the ability to ingest calories per os (what are known as restrictive techniques) have not proven to be effective in the long term. By contrast, reducing the ability to absorb ingested calories (“malabsorption”) appears to provide better and longer lasting outcomes. Historically, the biliopancreatic diversion (BPD) according to Scopinaro, or according to Marceau and Hess, constituted for years the gold standard of malabsorptive operations. These latter techniques, however, were fraught with a substantial incidence of perioperative complications and unwanted outcomes such as malnutrition and diarrhea. Quite logically, newer, less aggressive procedures, including SADI and OAGB emerged. They are the modern versions of malabsorptive procedures. The essential difference with classic BPD is the presence of just one anastomosis, whereas the main difference between the two resides in the incorporation versus the exclusion of the pylorus, respectively. The influence of both procedures on the uptake of carbohydrates, protein and fat as well as micronutrients is examined. The positive impact on obesity and on obesity-linked comorbidities is demonstrated. An essential and critical topic of interest in both operations is the “active” bowel length, i.e. the bowel that is in contact with the nutrient stream. Undesired side effects are described, and the “ad hoc” treatment explained. The conclusion is that SADI and OAGB are very effective procedures in the war on obesity, provided that some essential precautions are taken. Patient compliance and adequate lifelong follow-up are essential for an optimal outcome. Endorsed by: [Image]
With Johnson & Johnson MedTech
Published
May 2021
Gastro-gastric fistula is an uncommon complication of gastric bypass (both Roux-en-Y and single anastomosis). Its symptoms range from none (if the fistula is small) to severe (if the fistula is significant). Severe symptoms include: invalidating gastroesophageal reflux (GERD), and failure to lose weight. The treatment can be postponed when symptoms are mild, but more often than not, revisional surgery needs to be considered. Despite several isolated reports on success with endoscopic treatment, state-of-the-art treatment currently still consists of (laparoscopic) revisional surgery. This case is the laparoscopic revision of such a gastro-gastric fistula after a Roux-en-Y gastric bypass.
With Johnson & Johnson MedTech
Published
Jan 2019
The laparoscopic Roux-en-Y gastric bypass (RYGB) is currently one of the most common bariatric procedures. However, RYGB can cause specific undesired side effects related to the bypassing of a large part of the stomach, duodenum, and the proximal jejunum. These side effects include early dumping syndrome, hypoglycemia, malnutrition, severe diarrhea and excessive nausea, and vomiting. Although these conditions can usually be managed conservatively, occasionally a surgical reintervention may be required. Hence different reversal techniques, including endoscopic approaches, have been described. In extreme cases surgical options include reversal to normal anatomy (NA) or into sleeve gastrectomy or sleeve-like resection (NASG) to address undesired side effects. This procedure usually requires dismantling both the gastrojejunostomy and the jejunojejunostomy, reanastomosing the gastric pouch into a gastric remnant, and the proximal alimentary limb end into a distal biliary limb end. Eventually, concomitant hiatal hernia repair may be required.
With Medtronic
Published
Jan 2018
Clinical Case There is currently no consensus on the total small bowel length that should be bypassed during performance of the Roux-en-Y gastric bypass and on the relative proportion of the biliopancreatic limb and the alimentary limb. The reported lengths of the biliopancreatic limb and the alimentary limb vary widely from 10–250 to 35–250 cm, respectively. Nevertheless, there are no real standard measurement method or standard bowel limb lengths. The lengths reported by different surgeons are very difficult to compare. In bariatric surgery, bowel length determines the caloric absorptive capacity of the bowel and its ability to absorb micronutrients. The ratio between different bowel limb lengths and total small bowel length is of utmost importance for the success of bariatric surgery. An erroneous evaluation can have catastrophic consequences. In this lecture, Jacques Himpens reviews the literature on the the true importance of the length of the alimentary and biliary limbs, its influence on metabolic changes, and the use of a longer alimentary limb in special cases.
Published
Nov 2017
Clinical Case Dr. Aminian , Associate Professor of Surgery at the Cleveland Clinic, discusses a new method for selecting the most appropriate surgical technique for treatment of patients with type 2 Diabetes Mellitus (T2DM). He divides T2DM into 3 validated stages of severity and presents an online calculator ( http://riskcalc.org/Metabolic_Surgery_Score ) that may help in the selection of the surgical procedure for each patient, thus enabling a more tailored treatment of obesity and T2DM . He emphasizes the importance of surgical intervention in early stages of T2DM in order to achieve sustainable results. An international panel of experts from IFSO: Dr. Himpens (IFSO President), Dr. Cohen (Hospital Alemão Oswaldo Cruz, Brazil), Dr. Cummings (University of Washington, USA), Dr. Shikora (Brigham and Women’s Hospital, Boston, USA) and Dr. Lee (Min-Shen General Hospital, Taiwan) discuss Dr. Aminian’s lecture, highlighting the importance of the duration of T2DM on results, the importance of gastroesophageal reflux disease (GERD) on the choice of surgical technique compared with T2DM, and the possible future importance of C-peptide in metabolic surgery. Dr. Lee from Taiwan discusses the results available on the Asian population compared to those presented by Dr. Aminian. Finally, clinical cases are discussed in order to explain the use of the online calculator. [Image]
Published
Oct 2017
Clinical Case The prevalence of Barrett’s esophagus in Europe is around 1.3% to 1.6%. This incidence is claimed to be higher in patients on whom a sleeve gastrectomy has been performed. Dr. Alfredo Genco , from the Department of Surgical Sciences at La Sapienza University in Rome (Italy) argues that evaluating the gastroesophageal reflux after a sleeve on the basis of symptoms only is not enough. He reviews the literature and explains that there is an increase of Barrett’s esophagus from 0% to 14% in the long-term follow-up and that > 70% of the patients have bile reflux when evaluated with gastroscopy. Nearly 80% of patients have esophagitis according to the Los Angeles criteria. All this may be secondary to an intrathoracic migration of the esophago-gastric junction (72% of patients). He concludes that Barrett’s esophagus can progress despite medical therapy, and thus close follow-up including gastroscopy should be mandatory . In order to reduce reflux and its complications, a change of surgical procedure is needed to make sleeve gastrectomy safer. An international panel of experts from IFSO composed by Dr. Genco, Dr. Himpens, Dr. Lakdawala, Dr. Ramos, Dr. Angrisani, Dr. Higa, Dr. Zundel and Dr. Nimeri discuss the importance of GERD after sleeve gastrectomy, the treatment and prevention of Barrett’s esophagus in these patients, and the role of endoscopic follow-up and IBPs in these patients.
Published
Jul 2017
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