Surgical directions for obese patients
Bariatric surgery must be practised in higly-specialized centers which can offer multidisciplinary pre-surgical evaluations to the patients, in the presence of both a surgeon and an anesthesiologist specialized in the types of operation required.
The choice of a specific procedure depends on the degree of obesity, calculated according to the body mass index (BMI). The BMI is the maesure of the patient's weight divided by the square of their height:
BMI (kg/m2) = weight/height2
Surgical requirements for bariatric surgery;
• BMI > 40;
• BMI > 35 with related syndromes;
• Willingness to adhere to a new lifestyle after surgery;
• Awareness of surgical risks;
• Willingness to stand a long opst-surgical follow-up;
• Reticence to drugs or alcohol abuse;
• Absence of significant psychiatric symptoms.
The types of surgical procedures we practise to treat pathological obesity are:
• patients with BMI < 50
adjustable gastric banding
• pazienti with BMI > 50
RYGB gastric bypass surgery
Before the operation, in order to to improve the patient's anamnesis, a number of medical consultation must be planned in the areas of endocrinology, nutrition, psychiatry, anesthesiology, general surgery, pneumology, cardiology and rheumatology, all planned according to the syndromes the patient might be affected by.
Moreover, it is necessary to practise a clinical examination to the patient (with a measurement of their anthropometric values), a complete blood test, a cardiorespiratory test, a gastrointestinal examination with abdominal ultrasonography, esophagus and stomach x-ray examination with water-soluble contrast agents (gastrografin) and finally, in case of symptomatic reflux disease, an esophagus and stomach endoscopy, ph measurement and manometry.
Adjustable gastric banding
A well-established method is the adjustable gastric banding, which allows patients to immediately reduce the intake of food without suffering hunger pangs. Moreover, this is a completely reversible procedure.
That means that, once in good shape, the banding is removed from the patient's stomach.
Who is eligible for this procedure? It depends on a number of factors: in general, the doctor will identify the most suitable method after an evaluation of the patient's age, general health conditions, type of obesity and other factors. Adjustable gastric banding is perfect for young individuals who want to gain back their normal weight without drastic operations on their stomach size. In fact, thanks to this non-invasive technique carried out in laparoscopy, the upper portion of the stomach is tightened up by a silicone ring whose diameter is adjusted by the inflation of saline solution. What results from the procedure is a “pocket of stomach” which significantly reduces the amount of food the patient can ingest. In addition, the adjustable ring also controls the speed at which the food goes through the stomach. The banding method presents several advantages: firstly, no sectioning occurs and the operation is totally reversible (the ring can be removed once weight loss has occured); secondly, it helps to effectively reduce the sensation of hunger, allowing obese patients to modify their habits without suffering. Of course, as a reversible technique, all patients who have lost weight thanks to a gastric banding are seriously advised not to start eating as they used to do before, or their sacrifice will be in vain!
Soon after the operation, for four weeks, the patient's diet will be made of liquid or semiliquid food: vegetable purée, yogurt and anything along those lines. Only at the fifth week will they be able to add foods like meat and fish, but always in homogenized form. As all kinds of food are gruadually added, patients will feel a much reduced sensation of hunger, which will make it easier for them to have small and light meals throughout the day. These will be key to effectively and quite rapidly lose weight.
Of course, there's no sleight of hand: the patient's collaboration is still crucial! Throughout the period of gastric banding, besides strictly following the doctor's diet plan, physical exercise is needed and smoking is forbidden! Moreover, the patients' lifestyles and habits should become as healthy as possible.
Sleeve gastrectomy is a vertical gastrectomy carried out along the greater curvature, which completely eliminates the fundus, resulting in a residual stomach of about 60-150 ml. The integrity of the pylorus antrum and the vagus nerve is preserved.
What determines weight loss is the drastic reduction in stomach size, resulting in an earlier sense of satiety (even after ingesting small amounts of food) and the reduction in the levels of ghrelin, also known as the "hunger hormone". Recent studies have shown sleeve gastrectomy to be very capable of healing diabetes mellitus type 2 (80.3%) and some other preliminary observations of ours suggest this result to be independant of weight loss, given the early appearance of the effect.
It has also been suggested that this surgical procedure, regarded as something merely obstructive until recently, must trigger a hormonal mechanism responsible of controlling glucidic homeostasis.
The technique is employed in bariatric surgery in the first stage of biliopancreatic diversion with duodenal switch. In recent years, our staff and several other researchers have observed that the results accomplished in terms of overweight reduction and healing of related syndromes (especially diabetes mellitus type 2) were satisfying enough to dissuade patients from moving on to the expected second stage.
This resulted in a rising interest for sleeve gastrectomy and in a rapid diffusion of the technique, so much so that it has been officially recognized as a bariatric surgery procedure.
In fact, it presents various advantages compared to other methods: the technique is highly standardized and comparatively easy to perform; it can be carried out through laparoscopy even in case of super-super obesity; there are no anastomoses or mesenteric defects with risk of internal herniae; there are no intestinal bypass; it is not associated with malabsorption or dumping syndrome; the whole gastrointestinal tract remains possible to exolore via endoscopy; there are no prothesis (as it is the case of rings in adjustable gastric banding).
In patients with insufficient or no clinical result, if necessary, a malabsorptive amount (second stage in biliopancreatic diversion) can be added with standard procedures in conditions of reduced surgical risk.
Gastric bypass surgery
A gastric bypass is a hybrid bariatric surgery procedure, as it combines a reduction in size of the stomach with a malabsorpitive mechanism. It is the most frequently performed method in the USA and seems to present the best results in both weight loss and diabetes-type-2 reduction.
The gastric bypass surgery (also known as RYGB) is performed via laparoscopy by means of 6 or 7 trocars. It is carried out with the aim of a 45-millimeter linear suture machinery (green and blue) stitching a little 30-milliliter pocket near the lesser curvature, thus creating a vertical stomach partition up to the angle of his, excluding the fundus.
The malabsorpitive effect of this technique results from the creation of three different digestive loops: a biliopancreatic loop of about 30-60 cm, excluded from the digestive circuit where only liver and pancreas secretions will pass through; a feeding loop of about 100-150 cm anastomized alongside the stomach loop crated before, where food is maldigested in the absence of gastric juices; a common loop which comprises the remainder of the bowels below the Yanastomized loop, where food mixes up with biliopacreatic secretions.
As a result of this surgical implantation, fats are malabsorbed (as they are digested only in the presence of biliar salts). The same applies to proteins, although this happens on a smaller scale.
Carbohydrates, instead, are absorbed in the feeding loop and their large assumption is one of the main reasons for the failure of this surgical procedure. Another anti-hunger mechanism is triggered by the exclusion of the fundus, resulting in a descrease of ghrelin, which has been associated with hunger activation.
Gastric bypass, together with biliopancreatic diversion, are the surgical procedures with the best results in the treatment of overweight and diabetes type 2.
Favorable early results of gastric banding for morbid obesity: the american experience. C.J. Ren, M. Weiner, J.W. Allen, Surgical Endoscopy- 2004- 10-1007.
Sleeve gastrectomy as soel and definitive bariatric procedure: 5 years results for weight loss and ghrelin. A. Bohdjalian et al. Obesity Surgery 2010 20:535-540.
Metabolic Surgery for treatment of type 2 diabetes in patients with BMI<35kg/m2: An integrative review of eary studies. M. Fried et al. Obesity Surgery2010. 20: 776-790.
Minimally invasive bariatric surgery. Philip R. Schauer- Bruce D.Schirmer- Stacy A.- Brethauer- Springer editor.
Bariatric Surgery- Francis A. Farraye/ R. Armour Forse