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LRYGB superior to LSG for mid-term weight loss
Researchers from West China Hospital, Sichuan University, Chengdu, China, have reported that whilst both Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG) were safe and effective bariatric procedures in a their group of Chinese patients, LRYGB seemed to be superior to LSG in terms of mid-term weight loss. The paper, ‘Laparoscopic sleeve gastrectomy versus Roux-en-Y gastric bypass for morbid obesity: a 1:1 matched cohort study in a Chinese population’, was published in the journal Oncotarget.
The authors explained that bariatric surgery has been perform in China for no more than 20 years and the benefit of the procedures in Eastern populations is still uncertain, with several papers that comparing the two procedures reporting conflicting results.
"...the outcome of this study might be only suitable for Eastern or this Chinese population..."
Therefore, they conducted a retrospective study of patients who received LRYGB or LSG between January 2009 and January 2013, in West China Hospital, Sichuan University in China. They included the basic inclusion criteria for bariatric surgery according to the guideline of the Chinese Society for Metabolic and Bariatric Surgery (CSMBS). Before surgery, they recorded age, gender, education, height, weight, BMI, waist circumference, blood pressure, and details regarding obesity-related comorbidities. The operative time, postoperative complications, and length of hospitalization were also recorded.
Patients were requested to attend follow-up at six, 12, 24, and 36 months after surgery. All patients completed at least one year of follow-up. However, two LRYGB patient and one LSG patient failed to attend follow-up at the end of one years; at the end of three years, an additional two LRYGB patients and two LSG patients were lost to follow-up.
A total of 126 patients were enrolled into this study (n=63 LRYGB and n=63 LSG) and both groups were comparable in terms of sex, age, BMI, waist circumference and comorbidities. The mean operative time was 108.3 ± 21.3 min (range 80-185 min) in the LRYGB group versus 83.2 ± 23.7 min (range 60-160 min) in the LSG group, with a significant difference. The length of hospitalization and major complication rates were similar in both groups. Only one patient (in the LRYGB group) had postoperative gastrointestinal dysfunction, with severe abdominal distention and vomiting; the patient recovered after 24 days with medical treatment.
The maximum weight loss in the two groups was reached at one year after surgery, after that a slight weight regain appeared, but greater was in the LSG group (Figure 1). After surgery, mean BMI values at all follow-up time were significantly lower than preoperative status, and waist circumference changes were also reached significant differences at 12, 24 and 36 months postoperatively.
No significant differences were observed between the two groups in terms of mean %EWL at six, 12, and 24 months (62.4±14.7%, 80.1±10.6%, and 77.4±11.6%, respectively, in LRYGB patients vs. 56.3±17.2%, 76.7±12.9%, and 73.1±10.5%, respectively, in LSG patients). The BMI in the LRYGB group was slightly, but not significantly, lower than that in the LSG group at six, 12, and 24 months (29.8±2.2, 27.9±1.4, and 28.3±1.1, respectively, in the LRYGB group vs. 30.6±2.7, 28.5±1.9, and 28.9±3.1, respectively, in the LSG group).
Similar situation could also be found in terms of waist circumference, which no significant differences occurred between two groups at six and 12 months (92.5±9.3 and 88.7±8.8cm in the LRYGB group vs. 93.3±9.2 and 90.8±8.9 cm in the LSG group). However, at three-year follow-up, the mean %EWL in the LRYGB group was significantly higher than that in the LSG group (76.5±9.2% vs. 65.7±10.3%, p<0.05, Figure 1A), and, consequently the LRYGB group had a significantly lower BMI at three-year follow-up (28.2±1.5 vs. 30.9±2.4, p<0.05, Figure 1B). Also, the mean waist circumference values in the LRYGB group were significantly lower than that in the LSG group at 24 and 36 months follow-up (88.7 ± 6.5 and 89.8 ± 6.9 cm in the LRYGB group vs. 92.5 ± 6.7 and 92.7 ± 6.1 cm in the LSG group, respectively, P < 0.05, Figure 1C).
At follow-up one and three years after surgery, they report good resolution or improvement of obesity-related comorbidities such as T2DM, dyslipidemia, and sleep apnoea in both groups, but the differences were not significant (p>0.05). For T2DM, the remission rates at one year were 81.0% in the LRYGB group versus 68.8% in the LSG group, and at three years 63.2% in the LRYGB group, versus 57.1% in the LSG group.
“The starting and average BMI values of patients were lower than the western reports, which would obviously affect the long term %EWL in favour of a higher percentage,” the researchers note. “Therefore, the outcome of this study might be only suitable for Eastern or this Chinese population….Multi-centre, prospective researches with longer follow-up are required to further elucidate the long-term efficacy and safety of the two procedures.”
Figure 1: Postoperative changes of %EWL, BMI and waist circumference. A. Mean %EWL after LRYGB and LSG (with error bars—shown above mean for LRYGB and below mean for LSG—indicating standard deviation). B. Mean BMI values after LRYGB and LSG (with error bars—shown below mean for LRYGB and above mean for LSG—indicating standard deviation). C. Mean waist circumference values after LRYGB and LSG (with error bars—shown below mean for LRYGB and above mean for LSG—indicating standard deviation). * comparison between pre- and post-operation, P < 0.05. # comparison between LRYGB and LSG, p<0.05
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