WLS World: William B. Inabnet, MD

Duodenal Switch

I would like to share my personal post-op experiences, fact based knowledge and background regarding my surgery which is a combination of the Vertical Sleeve Gastrectomy (VSG) and Duodenal Switch (DS), performed under 1 surgical procedure. It is medically known as a a gastric restriction with partial gastrectomy, pylorus-preserving duodenoileostomy and ileoileostomy to limit absorption. It is known by its formality as a bilio-pancreatic diversion with duodenal switch and abbreviated as BPD/DS or DS. A not so wordy way to say it is sleeve gastrectomy with duodenal switch or just the DS.

I had my laparoscopic duodenal switch procedure on Nov 14th, 2006 for the surgical medical treatment of morbid obesity that can kill you. I am still the same person within, only my outer shell has morph to what I once looked like before this disease imprisoned me. The most important thing that matters is, I have my health back and that means more to me than the actual weight loss.

What is your body if you are not healthy with your respiratory, circulatory, cardiac and digestive system working properly and have mobility to be able to do things on your own, independently with no limitations, no complications or becoming a fatality?

This is what bariatric surgery outcome has done for me, give me my health as well as my life back!

The Duodenal Switch (DS)

The DS procedure has been performed since 1988 and combines restrictive and malabsorptive elements to help achieve and maintain long-term weight loss:

1. by restricting the amount of food that can be eaten through a reduction in stomach size

2. limit the amount of food that is absorbed into the body through a rerouting of the intestines

3. have a metabolic effect induced by manipulating intestinal hormones as a result of intestinal rerouting

The overall effect is that DS patients are able to engage in fairly normal, free eating, while having the benefit of taking on the metabolism of a lean individual.

Saturday, March 8, 2008

William B. Inabnet, MD

Positions and Appointments
2003-present Associate Professor
Clinical Surgery
Columbia University College of
Physicians & Surgeons
New York, NY
2003-present Associate
Attending Surgeon
New York-Presbyterian Hospital
Columbia University Medical Center
New York, NY
2003-present Chief
Endocrine Surgery Section
New York-Presbyterian Hospital
Columbia University Medical Center
New York, NY
2003-present Co-Director
New York Thyroid
Parathyroid Center
New York-Presbyterian Hospital
Columbia University Medical Center
New York, NY

Clinical Specialties
Minimally invasive thyroid and parathyroid surgery
Laparoscopic adrenal and pancreatic surgery
Laparoscopic bariatric surgery

* Appendectomy
* Bariatric Surgery (DS, LapBand, RnY, VSG, Revision)
* Colon Resection Surgery
* Gastrectomy
* Gastroesophageal Reflux Surgery
* Hemorrhoidectomy
* Laparoscopic Cholecystectomy
* Liver Biopsy
* Lumpectomy (Partial Mastectomy)
* Lung Biopsy
* Radical Mastectomy (Total)
* Splenectomy

Education and Training
Nov 1996-Oct 1997 Fellowship
Surgical Endocrinology
Cochin Hospital
Paris, France
Pr Yves Chapuis
July 1992-June 1996 Resident
General Surgery
Rush-Presbyterian -
St. Luke's Medical Center
Chicago, IL
July 1991-June 1992 Intern
General Surgery
Rush-Presbyterian -
St. Luke's Medical Center
Chicago, IL
1991 MD
University of North Carolina
at Chapel Hill
Chapel Hill, NC
1987 BS
University of North Carolina
at Chapel Hill
Chapel Hill, NC

Board Certifications
American Board of Surgery

Professional Experience
1998-2003 Assistant Professor of Surgery
Mount Sinai School of Medicine
New York, NY
1994-1996 Instructor of Surgery
Rush Medical College
Chicago, IL

Professional Honors
Strathmore's Who's Who
2003 Edition

American Registry
Top American Surgical Specialists
2002 & 2003

NY Magazine
Top 100 Laparoscopic Surgeons
2002

SAGES Video Achievement Award
2001

SAGES Video Achievement Award
2000

General Surgery Department Award
Chief Resident of the Year
1996

Chief Administrative Resident
1995-1996

Surgical Sciences Research Award
1994

Surgical Sciences Award
Intern of the Year
1992

Professional Societies
and Committees
Societies

American Association of Endocrine Surgeons
American Association of Tissue Banks
American College of Surgeons
American Society for Bariatric Surgery
American Society of General Surgeons
American Thyroid Association
Association for Academic Surgery
Association Francophone de Chirurgie Endocrinienne
French National Academy of Surgery
French Surgical Association
International Association of Endocrine Surgeons
International Federation for the Surgery of Obesity
International Society of Surgery
New York Surgical Society
Society for Surgery of the Alimentary Tract
Society of American Gastrointestinal Endoscopic Surgeons
Society of Laparoendoscopic Surgeons

Comittees

Chair
American Society for Metabolic and
Bariatric Surgery Research Committee
(ASBS)

Society for Metabolic and
Bariatric Surgery Program Committee
(ASBS)

Executive Council
American College of Surgeons Committee
for Video-Based Education

Selected Publications
Costen E, Gagner M, Pomp A, Inabnet WB.
Decreased bleeding after laparoscopic
sleeve gastrectomy with or without
duodenal switch.
Obesity Surg, in press

Inabnet WB, Quinn T, Gagner M, Urban M,
Pomp A.
Laparoscopic Roux-en-Y gastric bypass in
patients with BMI<50: A prospective randomized
trial comparing short and long limb lengths.
Obesity Surg, accepted.

DiGiorgio M, Daud A, Inabnet WB, Schrope B,
Urban-SkuroM, Restuccia N, Bessler M
Markers of Bone and Calcium Metabolism
Following Gastric Bypass and Laparoscopic
Adjustable Gastric Banding.

Books

Inabnet WB, Ikramuddin S, DeMaria E.
Laparoscopic Bariatric Surgery.
Lippincott, Williams, & Wilkins Sept, 2004

Gagner M, Inabnet WB.
Minimally Invasive Endocrine Surgery.
Lippincott, Williams, & Wilkins March, 2002.

Abstracts

Inabnet WB, Rogula T, Gagner M.
The safety and efficacy of alternative energy
sources in endoscopic thyroidectomy.
Surg Endoscopy 2003, 17:S304.

Comeau E, Gagner M, Inabnet WB, Herron D,
Quinn T, Pomp A.
Symptomatic internal hernias following
laparoscopic bariatric surgery.
Surg Endoscopy 2003, 17:S219.

Kim CK, Kim S, Eskandar Y, Krynyckyi BR,
Inabnet WB, Machac J.
The efficacy of dual-isotope substraction vs
dual phase parathyroid scintigraphy for directing
targeted surgery.
Radiology 2002

Kim CK, Kim S, Eskandar Y, Krynyckyi BR,
Inabnet WB, Machac J.
Any separation between abnormal foci and
the lower pole of thyroid on Pinhole Sestamibi
Parathyroid Imaging is highly suggestive of
Intrathymic/anterior mediastinal Parathyroid
Adenomas.
J Nucl Med 2002

Kim CK, Kim S, Eskandar Y, Krynyckyi BR, Zhang Z,
Knesaurek K, Inabnet WB, Machac J.
Appearance of Descended Superior Parathyroid
Adenoma on SPECT Parathyroid Imaging.
J Nucl Med 2002

Kim CK, Kim S, Eskandar Y, Krynyckyi BR, Haber R,
Machac J, Inabnet WB.
Efficacy of Parathyroid Scintigraphy (PS) vs
ltrasonography (U) for Directing Targeted
Surgery (DTS).
J Nucl Med 2002

Kini S, Gagner M, Gentileschi P, Nandkumar G,
Inabnet WB, Herron D, Pomp A.
Laparoscopic bariatric surgery for
super super obese patients (BMI>60):
a comparison of Roux-en-Y gastric bypass
and biliopancreatic diversion with duodenal switch.
Obes Surg 2001; 11:158.

Quinn T, de Csepel J, Kini S, Gentileschi P, Ren C,
Pomp A, Herron D, Inabnet WB, Gagner M.
Laparoscopic biliopancreatic diversion with
duodenal switch: the early experience.
Surg Endo 2001; 15(Suppl 1):S158.

Inabnet WB, Gagner M.
Endoscopic thyroidecomy: patient selection,
technique and preliminary results.
Surg Endosc 2001;.

Chapuis Y, Dousset B, Inabnet WB, Ozier Y,
Luton JP, Houssin D.
Facteurs prédictifs des complications opératoires
après surrénalectomie trans-péritoneale
vidéo-endoscopique.
Ann Chir 1999; 53:677.

Inabnet WB, Pitre J, Bernard D, Chapuis Y.
Comparison de paramètres hémodynamiques
à l'occasion de l'exérèse par vidéo-endoscopie
et voie traditionelle de phéochromocytomes.
Ann Chir 1999; 53:677.

Inabnet WB, Vogler RC, Arikan E, Sancar A.
Parasites are the most frequent pathogens of
acute gastroenteristis in southeastern Turkey.
Fax 1990; 5:77.

What is the Duodenal Switch?

With the DS procedure:

The stomach, although reduced to 50-75% its original size is fully functional. The duodenum is also fully functional with no bypass mechanism occurring. The entry and exit port of the stomach and the pyloric valve are untouched in its digestive configuration and left originally the same way before and after surgery. Keeping food in the stomach until it is digested prevents dumping, provide satiety and absorption of vitamins and minerals into the body.

This is important, since, the duodenum is the part of the intestine where protein, calcium, iron and vitamin B12 are absorbed and with the Gastric Bypass causes these four nutrients to not be absorb. The DS stomach processes the intrinsic factor that contains polysaccharide and protein components to make cyanocabalamin to be absorb as vitamin B12. The stomach and duodenum organs missing from the digestive system of the Gastric Bypass and is the main reason for pernicious anemia that is an iron deficiency developed due to lack of vitamin B12.

Even though, the DS has a greater malabsorptive factor, it actually has more normal nutritional absorption than the Gastric Bypass because the duodenum, stomach and pylorus are still involved in the digestive process. Therefore, the Gastric Bypass has MORE MALABSORPTION of vitamins and mineral causing greater possibilities of deficiencies, due to the complete removal (bypass) of the stomach and duodenal from its digestive absorption process and to have no function whatsoever.

Restriction
The restrictive part of the DS procedure is known as the vertical sleeve gastrectomy (VSG) and is achieved via partial gastrectomy (removal of the outer/greater curvature of the stomach). It reduces the size of the stomach 25-30% its original size and into a 2-3cm in diameter tubular structure which holds 3-4 ounces (80-120ml), compared to teh Gastric Bypass that holds 15-30ml restriction of food.

The grehlin hormone is also removed and eliminates head hunger, cravings and binging from occurring. The sleeve gastrectomy keeps and maintain the pylorus valve intact for the function in the emptying of the stomach contents to the duodenum at its normal controlled pace for better food tolerance and to limit the amount of food to be eaten.

Malabsorption
The malabsorptive component of the DS procedure is the intestinal bypass known as the duodenal switch. It is achieved by rerouting the small intestine into 2 intestinal tracts known as limbs. One tract separates the flow of food, known as the alimentary limb (or food limb) that measures on average 150-200cm, from the second tract known as the biliopancreatic limb (or digestive limb), where the flow of bile and pancreatic juices comes from the liver and pancreas to process for digestion. Reducing the amount of bile and pancreatic juices the food comes in contact with, reduces the amount of food that is digested and decreases absorption. The digestive limb, eventhough it is an intestinal bypass, is fully functional for processing in the digestive system.

Metabolic Effect

The alimentary limb:

1. absorbs proteins from ingested food

2. secretes the peptide hormone Enteroglucagon or GLP-1, which has 37 amino acids that controls the metabolism of glucose from undigested food. (This is the key reason (along with #4), why a DSer will NOT have Reactive Hypoclycemia occur or Diabetes resurface, even if they gain weight or are years out as post-op).

3. it suppresses the insulin response when carbs is ingested to reduce the amount that is converted to and stored as fat.

4. it increases insulin secretion as it decreases glucagon secretion from the pancreas that helps to treat and cure at a rate of 98.9% with PERMANENT REMISSION for Diabetes, even if there is a regain in weight.

Diabetes (type 2) will not return as per medical research and long-term studies that has been published, documented and recorded in medical journals, with the extremely small and rare exception of 1.1% whose Diabetes was still evident after surgery. With the Gastric Bypass, there is a high possibility that weight gain will cause Diabetes to resurface. It is NLIKELY with the DS to have post-ops with Diabetes or to have Reactive Hypoglycemia, as proven to occur among those with the Roux-en-Y or Gastric Bypass surgical procedure (whether at goal or regained weight), after being post-op for over a year or more.

For a RNY post-op, reactive hypoglycemia disorder does occur in those who never had Diabetes (related or non-related) prior to surgery or in their life. Again, this is NOT an occurrence that will happen with post-ops DSers.

Further down the digestive tract, the two separated limbs of the small intestines are rejoined to be connected at the ileum known as the common channel. This is where the food and digestive juices begin to mix and limit fat absorption, essential for good health to occur. The common channel length varies according to Hess method (100cm) or according to patient's needs, malabsorption level desired, etc., from 50-150cm. The common channel section is the ONLY portion of the intestines that a DSer is able to absorb calories, fats and complex carbohydrates and no where else in the small intestine digestive system.

With the DS, a person eating food will be unable to absorb:
* 50% of calories
* 80% of fats
* 40% of complex carbohydrates
* 0% of simple carbohydrates

Unlike the Gatric Bypass, the Duodenal Switch is an intestinal bypass and NOT a gastric bypass procedure. It is also a gastric restrictive procedure and again NOT considered a gastric bypass, since, digestion begins in the stomach breaking down food and it keeps the pyloric muscle between stomach and small intestine intact, allowing the stomach contents to start their digestive process before food enters the duodenum. This preservation eliminates the symptoms of dumping syndrome, marginal ulcers, strictures and blockages.

The gift of the DS is about OPTIONS. If I do eat anything, the malabsorption level and metabolic effect will prevent me from gaining weight and won't affect my arteries, blood or cholesterol level.

The majority of DSer do not have bathroom (diarrhea) or gas (flatuence) issues. A DSer become very much in tune. listening to their body for signals and its digestive system. You might have to moderate some food, but it does not need to be omitted or considered forbidden. The focus is not on calories, fat and not even on complex carbs as much. The main focus is on protein and nutrients. We must all eat food to survive and fuel our bodies for energy and nourishment.

The malabsorption of the DS is very powerful and will help you lose weight and keep it off long term. Without it, you're just on a diet after diet whether low calorie, low fat, avoiding certain food to not gain weight for life. The DS malabsorption eliminates the need to count fat, calories, certain amount of complex carb or any other diet mentality practices needed to either lose weight or to not regain weight. You eat normally (just smaller portion than a non-WLS) and do not have to deal with issues that it will harm or "punish" you since your stomach is fully functional to properly digest the food.

Gastric Bypass versus Duodenal Switch

In RNY procedure:
The duodenum and pyloric valve are bypassed and the intestines are connected to a newly created stomach pouch, known as a stoma. This digestive configuration is known as a gastric bypass. The stoma is able to hold one ounce of food, but its exit port is always open and does not store food causing it to glide through into the intestines non-stop which causes a possibility of dumping syndrome. Food is held in the pouch, depending on certain texture or bulk may get stuck with difficulties in processing to pass through the stoma, if not chew down to mush consistency. The stoma is similar to a funnel and does not have the ability to process food. Some consider dumping to be a key component of gastric bypass. Yet, it has been medically proven with published scientific report, medical data and research studies that there is no relation between dumping and weight loss. Due to the absence of a functional stomach and duodenum, nutrients are unable to be absorb. The duodenum is the site where most of the breakdown of food passes through and secrete an alkaline mucus that supports the intestinal enzymes and aids in the absorption of nutrients. The stomach is a secretory organ that include digestive enzymes, hormones, hydrochloric acid and intrinsic factor for vitamin B12 absorption are missing with the RNY or gastric bypass.

With the DS procedure:
The stomach, although reduced to 50-75% its original size is fully functional. The duodenum is also fully functional with no bypass mechanism occurring. The entry and exit port of the stomach and the pyloric valve are untouched in its digestive configuration and left originally the same way before and after surgery. This allows food and drink to be consumed at the same time and become iso-osmolar during digestion.

Keeping food in the stomach until it is digested prevents dumping, provide satiety and absorption of vitamins and minerals into the body. This also helps control weight as the DS stomach stretches a bit with time, as it is normally suppose to do. The pylorus stays shut while food and fluid are in the stomach, causing the stomach to work as a hopper and digest the food that provides nutrients as it process, then passes into the duodenum as it continues to absorb nutrients to the body.

This is important, since, the duodenum is the part of the intestine where protein, calcium, iron and vitamin B12 are absorbed and with the RNY causes these four nutrients to not be absorb. The stomach processes the intrinsic factor that contains polysaccharide and protein components to make cyanocabalamin to be absorb as vitamin B12. The stomach and duodenum organs missing from the digestive system of the RnY or gastric bypass is the main reason for vitamin B12 deficiency to occur.

Even though, the DS has a greater malabsorptive factor, it actually has more normal nutritional absorption than the RNY because the duodenum, stomach and pylorus are still involved in the digestive process.

As can be observed in the chart above, the DS is able to provide LESS MALABSORPTION of nutrients compared to the RNY, since a portion of the the true stomach and the duodenum are left intact and in full functional capacity to process in its digestive system.

Therefore, the RNY has MORE MALABSORPTION of vitamins and mineral causing greater possibilities of deficiencies, due to the complete removal (bypass) of the stomach and duodenal from its digestive absorption process and to have no function whatsoever.

The duodenal switch surgical portion has been perform as a stand alone treatment for Diabetes on obese and non-obese patients for over 20 years, based on the mechanics and metabolic process that takes place in the digestive system.

The majority of DSer do not have bathroom (diarrhea) or gas (flatuence) issues. A DSer become very much in tune listening to their body for signals and its digestive system. It all comes down to, the DS does most of the work for me, not me do most of the work to stay healthy or lose/maintain my weight. It is pleasant life to live with no restriction of food or ingredient being denied, considered wrong, not allowed or taboo. You might have to moderate some food, but it does not need to be omitted or considered forbidden.

The focus is not on calories, fat and not even on complex carbs as much. The main focus is on protein and nutrients. We must all eat food to survive and fuel our bodies for energy and nourishment.

The malabsorption of the DS is very powerful and will help you lose weight and keep it off long term. Without it, you're just on a diet after diet whether low calorie, low fat, avoiding certain food to not gain weight for life. The DS malabsorption eliminates the need to count fat, calories, certain amount of complex carb or any other diet mentality practices needed to either lose weight or to not regain weight. You eat normally (just smaller portion than a non-WLS) and do not have to deal with issues that it will harm or "punish" you since your stomach is fully functional to properly digest the food.

Metabolism
The actual duodenal switch in your intestines kick start your metabolism, even after being 5 years post-op. It truly is not easy to regain weight (unless you have mental issues with being non-compliant. Although, living with the DS is a very liberal and lenient lifestyle with hardly any restrictions or complicated regime). Simply stated, with the DS, you have options and it is up to you to what you want to eat if you want without harming your body through averse therapy or dealing with various dieting to lose or maintain weight. There is no drama eating food with the DS.

DS Lifestyle
DSer do not eat a lot of food per se. They may eat more frequently, but it is all basically portioned food every so often as needed. The VSG restricts the amount of food that you have in one sitting. DSers do not require to mandatory eat high fat food. It is an option, if you want. If a DSer is constipated, having the option to eat higher fat contents or even higher carb amount than usual, may help move things along. DSer do not have a lot of or more than normal, frequent daily bowel movement. On average, it is once to three times a day and all depends on what you eat. If you eat higher fat, there might be a possibility, you may go more. DSers do not pass gas all day. It all depends on what you eat.

Usually higher carbs or certain ingredients MAY cause gas to some (not the majority). Bowel and gas issues are the same as with all other WLS post-op individuals and not considered more or extreme. It is a fallacy. DSer are very much in tune to listen to their body and to its digestive system. Simple carbs, you have to moderate, as with all other WLS. Only thing is, you have the freedom to have it if you want, but know your limits.

Complex carbs are malabsorb, so enjoy that potato, corn, beans or favorite cereal. DSers on average malabsorb 40% of the complex carbs. One of the beauty of living the DS lifestyle is you are not freaking out, feeling guilty, having drama or need to count calories or fat from food because it will NOT cause weight gain as compare to other WLS.

You want fritters, that delicious savory sauce or gravy, that juicy marbled fat from a steak with all the au jus streaming down the side, the skin from a fried chicken, have creamy or flavorful oil based salad dressing or smear butter or mayo to your heart content to make whatever you are using it with taste good? Go ahead, it will not cause you to gain weight. If you want a fast food burger or fried chicken from KFC, no regrets. Both are high in protein, regardless of the amount of calories or fat it has because the DS is very forgiving to NOT allow your system absorb 80% of the fat, 50% of the calories and 40% of the complex carbs you eat.

It is all about protein and you more or less disregard the rest. You are also able to eat rice, bread, potatoes, raw vegetables, and because it is complex carb, do malabsorb some of the carbs from it. So, there is peace and no issues with food and most importantly, you want to drink that beverage, whether it is juice or carbonated with your food or meal, go ahead, it's all good (just make it low sugar, sugar free, best if it is caffeine free, too). If you are hungry, go eat and enjoy it. Your grehlin is removed, so you won't feel hungry all the times or have head hunger. If you are hungry, it means you are really hungry, so go eat. Food is no longer an issue because you will have the metabolism of a lean person. You eat because your body is signaling that you are truly hungry. You do not need to a plan a menu according to calories or fat (for yourself) because there is no cut off limit amount per day. Again, you won't be able to eat alot per serving. Food just doesn't become important that you think about it. You only think about protein. But remember, compare to calories, fat, complex carbs and simple carbs. You deal with one of them and that is knowing your limit or moderation to simple carbs. You can have it, including sugary stuff, just don't go buck wild exaggerating the intake amount every day.

Research, if you see any DSers having serious issues that they need to have a revision or having complications that it needs to be revised and especially to another surgery. The DS is very effective and rarely is there any failure due to its intestinal configuration to cause weight gain beyond your control.

Difference with RnY

RnYer have a 50/50 chance of having dumping syndrome and hope to have it to control their eating habits, needing that negative reinforcement for poor eating habits or "forced" to eat healthier or better quality of food. But it does not happen to all and 60% of the RNYers are left with the burden to be stuck on a low calorie, low fat, low carb diet for life on their own mental reinforcement because they did not get the gift of dumping syndrome to enable them to eat healthier with the contribution of their "tool".

This is why ther are some RnY post-ops who repeatedly, go over and over again to try to "recondition" themselves using the 5DPT (5 day pouch test) or the 3DLPT (3 day liquid protein test) as a sort of solution to help them out. But these options are not a weight loss regime or that they will lose weight on it if followed.

With the RNY, there are some side effects that can stop you from continuing on with your day and may even affect your health.

1. One is dumping syndrome, in which there are times the only solution is to go rest and sleep it off to get over the episode.

2. Second is reactive hypoglycemia, that affects your blood level, even if you never had diabetes in your life. It is also due to chromium, niacin, vitamin C and vitamin E not able to regulate the glucose level in their system due to the gastric bypass procedure. Vanadium may be helpful to normalize the metabolism and under a medical doctor supervision.

3. Third is food getting stuck or causing a stoma blockage (such as eating a raw carrot and didn't chew it down well), since you do not have a functional stomach that will grind food for you anymore. Some post-op sort to using meat tenderizer with some water to soften the bulk of food that is stuck or blocking the stoma for breakdown and does not remedy the condition right away.

4. Fourth is strictures, which may be painful and requires a trip to the hospital to have yourself dilated.

5. Fifth is marginal ulcers and especially in the blind stomach that can't be scope for evaluation.

6. Sixth is RnY should never use NSAID because they do not have the digestive acids to help prevent irritation inside the stomach lining.

If a person has a family history of arthritis, lupus, migraines or ulcers, this can be an important factor to decide on having the DS due to the need of NSAID and this means daily and for life.

Unlike the Gastric Bypass, the Duodenal Switch is an intestinal bypass and NOT a gastric bypass procedure. It is also a gastric restrictive procedure and again NOT considered a gastric bypass, since, digestion begins in the stomach breaking down food and it keeps the pyloric muscle between stomach and small intestine intact, allowing the stomach contents to start their digestive process before food enters the duodenum. This preservation eliminates the symptoms of dumping syndrome, marginal ulcers, strictures and blockages.

WLS World

Duodenal Switch

Saturday, March 8, 2008

William B. Inabnet, MD

Sarah'a WLS World

Normal Digestive System Anatomy

Blog Archive

DS medical studies, scientifc data and published research

What is the Duodenal Switch?

Gastric Bypass versus Duodenal Switch

Difference with RnY