LAUSR

I read the paper by Ahuja et al. [1] published recently in BObesity Surgery^ with considerable interest. Authors should be congratulated for this landmark study and their conclusion that 150-cm biliopancreatic limb (BPL) is adequate for patients undergoing one anastomosis gastric bypass (OAGB) is something that I have emphasised at times and again [2, 3], but there are several other important aspects of this study that I would seek your permission to highlight. First of all, it is worth noting that the authors chose a longer BPL for those with higher BMI, uncontrolled diabetes and hypertension, and for those on a non-vegetarian diet. Furthermore, they chose a shorter limb length for younger patients and females in the childbearing age group. This means the subgroups of patients undergoing OAGB with different BPL are likely to be very different. The paper [1] does not provide us with the basic demographics of the three groups making it difficult to ascertain if they are comparable. In particular, I would be interested to know the baseline weight and BMI of different groups as that can profoundly alter the interpretation of any weight loss data. In this relatively small series of 101 patients, authors report one late mortality out of 20 patients who underwent an OAGB with a 250-cm BPL. The patient experienced severe protein deficiency and liver failure and ascites. This is not the first time a mortality has been reported with a BPL of > 200 cm with OAGB either [4]. Authors report another patient in this subgroup of 250-cm BPL who needed parenteral nutrition and a third one who needed iron infusion and blood transfusion for severe anaemia. This is precisely why we advise against [2, 3] the tailoring algorithms where authors [5] have recommended longer BPL lengths for heavier patients undergoing OAGB. This is all the more important because we now know that the efficacy of a gastric bypass is not directly proportional to the length of the small bowel bypassed and that bypassing the first 150 cm of small bowel appears to give optimum results [6]. The group undergoing an OAGBwith a BPL of 180 cm is particularly interesting especially because a recently published consensus statement [7] on this procedure stated that Bit is acceptable to routinely use a standard BPL of up to 200 cm with careful monitoring.^ This recommendation was notwithstanding the fact that historical series on this procedure [8] have shown a 1.1% rate of Bexcessive weight loss with malnutrition^ with a BPL of 180 cm. In this study [1] too, 1/49 (2.0%) patients needed parenteral nutrition for severe protein deficiency. Furthermore, approximately 25.0% of 180-cm BPL group patients developed hypoalbuminaemia compared to 6.5% of the 150-cm BPL group in this study. At the same time, the authors have shown a significantly higher absolute weight loss in kilogrammes at 1 year in patients undergoing a BPL of 180 cm in comparison to those with a BPL of 150 cm. This needs further probing. Given the expected difference in baseline weight and BMI of these patients, I wonder if a comparison of percentage total weight loss might have been more appropriate especially since there was no statistically significant difference in the percentage excess weight loss between the two groups. I would have further liked to see the mean (with standard deviation) and median weight and BMI at 1 year in different groups to understand the weight loss differences better. This is especially important because one patient in the 180-cm BP limb group had lost as much as 134.5 kg. This could have potentially altered the mean total weight in kilogrammes for the whole subgroup in this small series. Despite these minor issues, this paper [1] is the first scientific attempt to study the effect of different BPL lengths in the context of OAGB and authors need to be commended for that. * Kamal K. Mahawar [email protected]