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Impact of the Laparoscopic Gastric Bypass Roux Y

The laparoscopic or open gastric-bypass with roux-en-Y limb is associated with minimal but known, potential complications. Prospective patients need to understand the following potential side effects of surgery:


·        Dumping Syndrome:  


One of the physiological mechanisms of the gastric-bypass for generating a sustained weight-loss comes from the rapid passage of the swallowed nutrients from the gastric pouch into the small intestine or jejunum (roux limb). 

This new or bypassed pathway is essential, as the jejunum is simply not made to handle concentrated calories, especially refined sugar.  Consequently, if a patient eats concentrated sugar or fat (such as ice cream or chocolate) after a gastric-bypass, this nutrient, when in the manipulated segment of intestine, will generate a physiological reaction identified as a Dumping Syndrome. 

The patient may experience palpitations (heart racing), a sweaty and clammy feeling, cramping, abdominal pain, and diarrhea, followed by a feeling of weakness. The patient simply must lay down until symptoms pass. 

Dumping Syndrome is not dangerous but is frightening to the uneducated patient. It is a natural and expected consequence of this procedure. Dumping Syndrome is beneficial as it eventually deters patients from ingesting the type of food that should be avoided.  In addition, patients who do experience severe dumping syndrome, always report significant improvement with time.


The Physiology of Dumping Syndrome


There are two phases of the Dumping syndrome: an "early" and "late" phase. Early dumping is caused by the high osmolarity of simple carbohydrates reaching the small bowel. The various types of sugar all have small molecules, so that a gram of (for example) sucrose has many more molecules than a gram of protein, creating a higher concentration of molecules from simple sugars than from other foods. This creates fluid shifts inside the small bowel toward the higher concentration of molecules. If a patient consumes a bite of milk chocolate (lots of sugar), this bite of chocolate inside the Roux limb will promptly attract fluid into the bowel. This rapid filling of the small bowel stretches it causing abdominal cramping. It will then generate a cascade of hormonal changes and neural responses responsible for heart palpitations, a feeling of fatigue, clamminess and sweats. Vomiting or diarrhea may follow, as this fluid will act as a cathartic. 

Late dumping is associated with rapid changes in the blood sugar level during this syndrome. The small bowel absorbs sugar readily prompting a sudden and quick elevation of the blood sugar level. In turn, the pancreas responds to this glucose load by increasing its output of insulin. Because of the Roux en Y limb, the output of insulin released by the pancreas is always disproportionably too high for the sugar load detected by the small bowel. This will produce a transient hypoglycemia (low blood sugar) which will leave the patient temporarily weak, sleepy, and profoundly fatigued.
Dumping is not seen in non-operated individuals as the intact stomach controls and regulates the amount of nutrients and food going into the small bowel at all time. In addition, in a normal individual, by the time the sugar reaches the small bowel it has been mixed with bile, gastric, and pancreatic secretions, which will delay its absorption.


Obviously, surgeons consider dumping syndrome to be a beneficial effect of gastric-bypass. It provides quick and reliable negative feedback for the intake of the "wrong" foods. In practice, most patients do NOT experience full-blown dumping more than once or twice. Most simply say that they have "lost their taste" for sweets. It is however essential for the patient to discuss these symptoms with their surgeons.



·        Mineral Absorption: 


After a Gastric-Bypass with Roux-en-Y Limb, the lower part of the stomach and the upper (proximal) part of the small intestine do not participate in the normal digestion of food. These excluded portions of the gastro-intestinal tract, however, play an important part in the absorption of some minerals (iron, calcium, and to a lesser extent magnesium) and vitamins (vitamin B12 and to a lesser extent B6).  To compensate for this loss of function, patients who have undergone a Gastric-Bypass with Roux-en-Y Limb will need to take multi-vitamins with iron, and supplemental calcium every day for life.  Up to 20% of patients also require supplemental B12, which is taken as a sublingual pill weekly.


·        Lactose Intolerance: 


Lactose ("milk sugar") is a specific type of sugar found in milk and dairy products.  Absorption of lactose requires a particular enzyme that is found in the bypassed segment of intestine.  Many of the patients who did well with milk before surgery will find that after gastric-bypass, dairy products will cause abdominal cramping and flatulence.  Taking Lactaidä, an over-the-counter enzyme supplement, will prevent such problems. Again, an adaptation phenomenon will occur within 6-months after the procedure.


·        Hibernation Syndrome: 


Reduced calorie intake, or deprivation, will generate significant fatigue in 20% of the post-operative patients approximately 1-month after surgery. The energy level of these patients naturally drops generating a sequence of emotional problems including depression. This is a normal phase, which will resolve as soon as this adaptation process is complete.


·        Hair Loss: 


Most patients will report some increase in hair loss about 3-months following surgery.  For some patients this hair loss is dramatic. They describe clumps of hair in their brush, hair covering the shower floor, etc.  This is a secondary effect of the sudden calorie and protein deprivation. The body puts some of its normal maintenance activities "on hold" until appropriate nutrition is again provided. This hair loss is a temporary process. Actually, by the time patients first notice hair loss, their follicles are already regenerating hair. In fact, 18-months after surgery most patients have fuller, healthier hair because the body's hormone balance has been significantly improved.  The best prevention of this hair loss is to maintain a 45 – 50 gr. daily protein intake.


·        Excess Skin: 


Unfortunately, the skin that holds the excess fat before surgery does not entirely shrink with weight loss.  Post-operative exercise is essential to minimize this problem. Most patients are left with large, floppy areas of skin, especially on the abdomen, upper arms, thighs, and breasts. Actual resection or removal of the excess skin by plastic surgery is frequently desired by the patient. Although most insurance companies view this as cosmetic surgery; we do not share this opinion.  We recommend patients wait at least 18 – 24 months following the gastric bypass to undergo surgery for removal of excess skin. At this time the patient’s weight will have stabilized.


·        Gallstones: 


Cycles of weight loss and weight gain predispose the patient to the risk of forming gallstones. As a result, most patients who undergo bariatric surgery have already had their gallbladders removed.  For patients who have their gallbladder, their surgeon will determine (through sonogram, symptoms, etc.), prior to the surgery, if it will need to be removed at the same setting. For prospective patients who have their gallbladder, the rapid weight-loss generated by the bariatric procedure will increase their risk of forming gallstones in the early post-operative period. They will be asked to take Actigallä or URSO™ (a bile thinning medicine) for 6-months after surgery. In our office, only 7 % of the patients who have their gallbladder will require having their gallbladder removed post- laparoscopic gastric-bypass.


·        Marital and Relationship Distress: 


Every interpersonal relationship in which the patient participates will change substantially as dramatic weight-loss occurs.  This includes the marital relationship. 



The Gastric Bypass with Roux-en-Y Procedure has been performed since the late 1960’s; therefore, post-operative side effects related to this procedure are well documented. It is considered the "Gold Standard in bariatric surgery". It is essential the bariatric patient be properly educated as to what to expect after surgery. A well-educated patient is a better surgical patient.

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