Our group at University of Genoa School of Medicine has extensive experience with hypoabsorptive bariatric surgery, and our paper highlights the results of biliopancreatic diversion (BPD) at very long term.
Two main findings emerged from the study: first, hypoabsorptive bariatric surgery is very effective at maintaining a stable weight loss and excellent control of the metabolic comorbidities decades after the initial operation, but second, this comes at high, and ever increasing, clinical cost. At 20 and 30 years after surgery, most patients had experienced at least one or more metabolic complications. The full magnitude of these complications became evident only in the long term.
Whenever we advocate lifelong, chronic follow-up to prevent nutritional or metabolic adverse events, we must understand that, in practice, this is unlikely to be possible. In this series, long term supplementation was either unsustainable, or insufficient to prevent the occurrence of complications. Furthermore, as patients aged, their tolerance to the operation changed, and the effects of this change were difficult to predict.
BPD may have been largely abandoned from clinical practice, but duodenal switch (DS) and single anastomosis duodeno-ileal bypass-with Sleeve Gastrectomy (SADI-S), two increasingly popular hypoabsortive operations, seem to lead to similar results in the medium term, and we are concerned about their long-term outcomes, which may not be apparent yet.
To what extent these long-term outcomes will be bearable for both the patient and the health care system is a matter of contention, as well as whether the benefits obtained with the control of severe obesity and diabetes will offset the complications caused by this type of surgery.
Phase four studies are essential whenever new drugs are investigated. We encourage the metabolic bariatric surgery community to do the same, and we hope not to see a surge in surgical revisions after hypoabsorptive bariatric metabolic operations in an ageing postbariatric population.
