For a proportion of obese patients, metabolic bariatric surgery is an option that can give very positive results in terms of weight loss even years after surgery, and therefore reduce the risk of important comorbidities including cancer. Naturally, the scalpel is not for everyone: “The path of surgery is reserved for some patients. The selection does not depend only on the physical characteristics of the obese person, but also on the comorbidities they present, on their eating habits, lifestyle and, last but not least, also on their ability to adhere to the therapies once they leave the hospital”. explains Marco Raffaelli, full professor of Surgery at the Catholic University of the Sacred Heart and Director of the UOC Endocrine and Metabolic Surgery of the Agostino Gemelli Polyclinic in Rome. Naturally the BMI (the Body Mass Index, i.e. the ratio between a person’s weight and height) is a good starting point: an individual is considered overweight with a BMI between 25 and 30, has class 1 obesity between 30 and 35, class 2 between 35 and 40, class 3 over 40. In principle, the specialists say, the candidate patient is one who has a BMI between 35 and 40, who has important comorbidities, for example diabetes mellitus type 2, and in which the other ways – such as the pharmacological one – have not given the desired results. But beware: scalpel and chemistry are not antagonists, on the contrary. Effective drugs are available today, and even more targeted molecules are on the way. And the weapon to really fight obesity is often in the synergy between the two strategies. The drugs can be used pre-operatively if the BMI is too high, and represent an aid a few years after the operation if the patient regains a few pounds.
The multidisciplinary team always decides on the type of intervention. The important thing is that the obese patient turns to competent people and certified centers (the Italian Society of Obesity Surgery, for example, regularly checks the characteristics of the accredited centres). Depending on the characteristics of the patient, one of the options available today can be chosen between restrictive operations – which reduce the size of the stomach with less food intake – malabsorptive, which reduce the absorption of nutrients, and mixed which combine the previous characteristics. In 99 percent of cases the interventions are performed in laparoscopy, the “gentle surgery” which no longer involves the traditional cuts but small incisions in the abdomen and which guarantees a better post-operative course.
For example, the adjustable gastric band belongs to the restrictive category, which was very popular in the past and which is less practiced today. It is a ring placed around the stomach, connected by a small tube to a reservoir placed under the skin of the abdominal wall. Thanks to the injection of a saline solution into the tank, it is possible to narrow or widen the ring so as to vary the portion of the stomach. It is the least invasive operation that exists, but it assumes a great adherence of the patient to the good rules of nutrition and lifestyle in the post-operative period, following a supplementation program if necessary.
Still in the context of gastric reduction, the most widespread operation today in Italy and in the world is that of the “sleeve gastrectomy”: the operation involves the removal of about 4/5 of the stomach. An irreversible procedure which, however, has a double action: not only does it reduce the size of the stomach, but it also produces an anorectic effect due to the reduction in the production of neuro-hormones. For this reason the intervention, say the experts, has a great initial effectiveness, but after about a year and a half the anorectic effect disappears and only the restriction remains. Therefore, if the patient has not respected the rules of bariatric surgery, has not stayed away from sugars or has not chewed well, the residual portion of the stomach can dilate and the patient can have a weight gain. Fortunately, there are “lifesavers” such as supportive drug therapy. The important thing is that the patient goes to check-ups regularly.
One of the oldest methods is instead that of gastric bypass, which first of all involves the creation of a small gastric compartment in the upper part which excludes the rest of the stomach, and the exclusion of the duodenum and part of the jejunum thanks to a bypass. It is an operation that gives a good guarantee of medium and long-term results greater than the previous two and is very effective in the case of diabetic patients who very often manage to interrupt the therapy or strongly reduce the insulin dosages with partial or total diabetes. There is also a version similar to the previous one, the “single stomosis bypass”, which adds the exclusion of the large intestine with consequent malabsorption. The 15-year results show that it is more effective than the previous three both for weight loss and for the reduction of comorbidities (hypercholesterolemia, hypertension, diabetes and sleep apnea). However, being an important operation, it is good that the patient adheres closely to the follow-up indications, with at least two years of vitamin supplementation.