TECHNICAL DEBATES:
'LOW BMI' OBESITY SURGERY: IS IT WORTHWHILE ?
The guidelines for bariatric surgery have been established a long time ago: the criteria proposed by the National Institutes of Health -NIH- Consensus Conference in the United States, 1991, have been adopted by all national obesity surgery societies, and by the International Federation for Surgical Obesity (IFSO).The requested BMI for surgery is intangible: 40 kg per square-meter, or between 35 and 40 in case of co-morbidities (related diseases such as diabetes mellitus, hypertension, high cholesterol...).

Real obese patients with a BMI lower than that are not eligible for surgery. Actually a minority of obese patients is actively seeking surgical therapy, but some of them are borderline in terms of BMI and might be  positively impressed by the results of friends or relatives obtaining good results after surgery. It is highly debated wether or not surgeons should respond to such claims, regardless the reimbursement issue (in some countries like France, an application is made to get approval from health authorities).

Italian surgeons had the courage to present their results in patients operated on 'outside of the usual criteria' within the Italian National Registry of Obesity*. This series had 225 patients among 3319 patients operated on all over Italy, which accounts for 6,8% of the bariatric procedures. It has been pointed out that some of these patients had a previous failed bariatric procedure. More than half of the patients (109) had a related comorbidity (mostly psychological disorders...). The vast majority of the patients had the simplest procedure: the lap-banding. The resulting weight-loss was satisfactory, with an average excess-weight-losss of 60% at 5 years. Early complications were expectingly rare, but long-term complications were comparable to those of other bariatric patients: 9%. These late troubles imposed re-interventions for removal of the prosthetic material, and one patient died 20 months after surgery due to a pouch dilatation and subsequent gastric perforation. This makes us question the ethical background of such therapeutic proposals. Prospective and randomized studies should be initiated comparing surgery to other conservative treatments in non morbid obese patients. For the time being, the medical community stands for non surgical options, including diet support. Besides, long-term results of surgical procedures are still debated, and some papers have stressed problems due to the material. Improvement of the quality of life and comorbidities are also under scrutiny. There is no strong consensus so far, and available recommandations from scientific societies are still valid. However, 'less invasive procedures' (such as lap-banding, or gastric stimulation in the near future?) have led some surgeons to more liberality, whereas more invasive techniques (bypass) should be excluded.

* Angrisani L. Lapband system. Results of a multicenter study on patients with BMI<35 kg/m2. IFSO 2002.