We have read the letter by Bhoyrul et al.  in response to our recently published article Safety and effectiveness of bariatric surgery: Roux-en-Y gastric bypass is superior to gastric banding in the management of morbidly obese patients. We strongly disagree with the content of the letter. There continues to be much often heated debate regarding the potential benefits of laparoscopic banding versus Roux-en-Y bypass. Not infrequently, personal interests and financial incentives bias surgeons considerably regarding the effectiveness and perceived advantages of these procedures. However, it is of cardinal importance that surgeons and other health care professionals unemotionally base their opinion on high-level evidence such as randomized controlled trials and well-performed systematic reviews.
It is a fact that the available high level evidence clearly favours gastric bypass over gastric banding. The only currently available randomized controlled trial comparing laparoscopic banding versus laparoscopic Roux-en-Y bypass  convincingly demonstrates that patients undergoing Roux-en-Y bypass had significantly greater weight loss compared to the banding patients. Conversely, weight loss failure was significantly more prevalent in the gastric banding group. This difference in favour of the laparoscopic gastric bypass group was not only statistically significant but also clinically relevant.
Similarly, the vast majority of comparative studies favour gastric bypass. A recently published, well-researched and well-performed systematic review included 14 studies comparing Roux-en-Y bypass versus gastric banding . This investigation showed that excess body weight loss was consistently and statistically significantly better in patients undergoing laparoscopic Roux-en-Y bypass. Furthermore, the rate of resolution of comorbid diseases such as diabetes, arterial hypertension, dyslipidemia, sleep apnea syndrome, and osteoarthritis was consistently better in the bypass group. Finally, patient satisfaction was significantly higher in the bypass group. Based on these results, the authors of this systematic review concluded that laparoscopic gastric bypass should be the primary bariatric procedure in the management of morbid obesity.
It is surprising and unfortunate that the letter to the Editor by Bhoyrul et al. is not supported by any high-level scientific evidence whatsoever. Conversely, the authors base their opinion mostly on low level evidence such as single-institutional case series (level IV evidence) and expert opinion (level V evidence) . Most surprisingly, the authors do not comment on the only randomized controlled trial comparing laparoscopic Roux-en-Y bypass versus gastric banding, a trial, which clearly favoured gastric bypass. Their letter is itself biased, unsubstantiated, and not supported by the current literature.