Roux-en-Y gastric bypass (RYGB) with a biliopancreatic limb (BPL) length ≥100cm resulted in higher odds of achieving ≥ 25% total weight loss (TWL) at five years and the beneficial effects of long BPL were also found for achieving long-term improvement in type 2 diabetes and hypertension, according to a study conducted by the Dutch Audit for Treatment of Obesity (DATO) Research Group. Conversely, they found shorter alimentary limb (AL) procedures were associated with worse outcomes in terms of gastro-oesophageal reflux disease (GERD) improvement> They stated that these findings emphasise the importance of considering patient characteristics during limb length decision-making strategies in RYGB.
The study authors noted that there are no criteria regarding the optimal length of the BPL and AL, with many variations of the RYGB procedure incorporating various combinations of limb lengths. Indeed, there is considerable ongoing debate on which limb length combination results in the best outcome. The literature indicates that longer BPL induces extra weight loss, although elongation of the BPL might result in more micro nutritional deficiencies. A meta-analysis that examined T2D improvement rates for different limb length combinations in RYGB and found in meta-regression analysis that BPL ≥ 100 cm was associated with higher T2D improvement rates than BPL < 100 cm, while such an association was not found for the AL.
Given the paucity of data, the DATO researchers used a population-based cohort from the Dutch quality registry and compared patients undergoing RYGB with a long BPL versus a short BPL (defined as BPL≥100 cm and short BPL as BPL<100cm) on achieved weight loss and comorbidity improvement at five years follow-up. For both the primary and the sensitivity analysis they assessed whether the AL length influenced the outcomes, by creating subgroups with long or short AL (long AL defined as >100cm and short AL ≤100cm). As only very few patients received short BPL combined with short AL, the short BPL group was not further subdivided, the noted.
The primary outcome was achieving 25% (TWL) at five years after surgery and secondary outcomes included %TWL on a continuous scale, absolute change in BMI (ΔBMI), percentage excess weight loss (%EWL), postoperative complications and any improvement in DM, hypertension, dyslipidaemia, obstructive sleep apnoea syndrome (OSAS), GERD and musculoskeletal pain at five years follow-up.
A total, 5,051 RYGB patients (87.2%) were included in the analysis and after matching, there were 1,264 patients in both the long and short BPL group. Median BPL length was 150cm in the long BPL group and 70cm in the short BPL group. The median AL length was 100cm in the long BPL group and 150cm in the short BPL group.
Outcomes
At five years follow-up, 65.9% of the matched patients achieved at least 25% TWL, but the odds to achieve 25% TWL was significantly higher for patients in the long BPL group compared with those receiving a shorter BPL (p=0.04). Considering %TWL on a continuous scale, this was 1.26%-points higher in the long BPL cohort (29.7% vs. 28.4%, p<0.01) and %EWL and ΔBMI were also significantly higher.
With respect to comorbidity resolution, patients with a long BPL were more likely to show improvement in DM (p<0.01) and hypertension (p=0.02). There were no significant differences in improvement of the other comorbidities. These results should be interpreted in the context of data completeness of comorbidity status during follow-up, which was over 80% for DM but relatively low for the other comorbidities. Patients receiving long or short BPL had similar risks of postoperative complications (p=0.70).
Patients receiving a longer BPL (median 150cm) combined with a short AL had significantly higher odds to achieve improvement in diabetes and hypertension at five years, but also significantly lower odds to achieve improvement in GERD. Patients receiving long BPL (median 100cm) combined with a long AL did not differ in outcomes at five years from patients receiving a short BPL.
The odds to achieve 25% TWL at the last available follow-up was significantly higher for patients receiving a long BPL (p<0.01). The other weight-related outcomes also showed similar significant differences as in the primary analysis. Long BPL had favourable results on improvement of DM, hypertension, dyslipidaemia and OSAS.
However, patients receiving long BPL had lower odds to achieve improvement in GERD (p<0.01). There were no differences for amelioration of musculoskeletal pain or risk of postoperative complications.
The favourable results for the long BPL group were found in both AL length subgroups for achieving 25% TWL and improvement in DM and OSAS, improvements in hypertension was only seen patients receiving a longer BPL (median 150cm) and short AL. Improvements in dyslipidaemia and musculoskeletal pain was seen for patients receiving long BPL (median 100cm) and long AL. The lower odds to achieve improvement in GERD was only seen for patients receiving a longer BPL and short AL.
“Based on the current results, a BPL of ≥100cm can be advised, but it should be kept in mind that long BPL procedures are frequently accompanied by a shorter AL, which can be undesirable for patients with GERD,” the authors concluded. “Therefore, for these patients, it could be preferable to receive a longer AL, potentially at the cost of a somewhat shorter BPL.”
The findings were reported in the paper, ‘The Impact of Longer Biliopancreatic Limb Length on Weight Loss and Comorbidity Improvement at 5 Years After Primary Roux-en-Y Gastric Bypass Surgery: A Population-Based Matched Cohort Study’, published in Obesity Surgery. To access this paper, please click here
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