Biliopancreatic Limb Length as a Potential Key Factor in Superior Glycemic Outcomes After Roux-en-Y Gastric Bypass in Patients With Type 2 Diabetes: A Meta-Analysis.

BACKGROUND
Optimal length of biliopancreatic (BP) and Roux limb in Roux-en-Y gastric bypass (RYGB) for improved glycemic control are not known.


PURPOSE
To investigate how the lengths of the BP and Roux limbs in RYGB differentially affect postoperative glycemic outcomes in patients with type 2 diabetes.


DATA SOURCES
We conducted a systematic literature search using the PubMed, Embase, and the Cochrane Library databases.


STUDY SELECTION
We included studies that reported glycemic outcomes after RYGB and lengths of the BP and Roux limbs.


DATA EXTRACTION
A total of 28 articles were included for data extraction. Glycemic outcomes after RYGB were assessed on the basis of two definitions: remission and improvement.


DATA SYNTHESIS
We categorized the included studies into four groups according to the BP and Roux limb lengths. The type 2 diabetes remission/improvement rates were as follows: long BP-long Roux group 0.80 (95% CI 0.70-0.90)/0.81 (0.73-0.89), long BP-short Roux group 0.76 (0.66-0.87)/0.82 (0.75-0.89), short BP-long Roux group 0.57 (0.36-0.78)/0.64 (0.53-0.75), and short BP-short Roux group 0.62 (0.43-0.80)/0.53 (0.45-0.61). Meta-regression analysis also showed that a longer BP limb resulted in higher postoperative type 2 diabetes remission and improvement rates, whereas a longer Roux limb did not. There was no significant difference or heterogeneity in baseline characteristics, including diabetes-related variables, among the four groups.


LIMITATIONS
Not all included studies were randomized controlled trials.


CONCLUSIONS
Longer BP limb length led to higher rates of type 2 diabetes remission and improvement by 1 year after RYGB in comparisons with the longer Roux limb length.