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Magnetic anchoring device assisted-LSG is safe and effective

Magnetic anchoring device assisted-laparoscopic sleeve gastrectomy (MLSG) is safe and effective in terms of weight loss, shorter length of stay in hospital, comorbidities remission and improvement of quality of life (QOL), according to researchers from the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China. In this small single-centre study, the investigators compared patients who underwent either conventional LSG (n = 120) or MLSG (n = 115) and followed patients for two-years.

The study authors explained that magnetic-assisted surgery is conducted by using the specially designed magnetic medical instruments or equipment to transform the non-contact magnetic field force between magnetic substances into a force that can play a specific function in clinical diagnosis and treatment. Liver retraction during bariatric procedures enables exposure of the surgical field to be adequate, especially for the visual accessibility to the stomach and gastroesophageal junction. The retraction with the assistance of magnetic anchoring device is a non-invasive and effective strategy.

The CLSG was performed routinely with four or five trocars, while the MLSG was performed with three trocars. Liver retraction of MLSG started by attaching the magnetic tissue clip to the liver lobe (Figure 1). The diameter of the magnetic tissue clip was 12mm ± 0.3mm, which enabled the clips go through the 12mm trocars. Then, the magnetic traction device, which was adjustable and supported by the self-balancing manipulator, was adjusted to approach to the magnetic clips to perform the liver retraction and improve the surgical field with a better visualisation and triangulation.

Figure 1: The magnetic retraction system for surgical field exposure, and intra-operative picture of MLSG.


There were no significant differences between the two groups in terms of age, gender distribution, BMI, abdominal girth and co-comorbidities. The mean age in the CLSG and MLSG groups was 32.83±9.185 and 33.33±8.870 respectively, and the mean pre-operative BMI was 38.76±6.881 and 39.28±6.515 respectively.

No patients required conversion to open surgery. The MLSG group had a slightly shorter mean operative time vs. the CLSG group (72.59±10.86 vs. 76.67±10.67, p=0.0030), the MLSG group had a shorter length of stay in hospital than the CLSG group (5.592±0.974 vs. 5.958±1.337, p=0.0159). There was no significant differences in postoperative complications, the prevalent one in both groups was nausea or vomiting (10% vs. 8.7%, p=0.902). There were no instances of bleeding or wound infection after the surgery. There was no technical event or surgical device fault during all the operations.

Two years after surgery, the mean BMI was 23.39±5.047 in the CLSG group and 23.12±4.795 in the MLSG group and the mean excess body weight loss percentage (EBWL%) in the CLSG group was 39.12±11.04% vs. 40.57±10.83% in the MLSG group. There were no significant differences between the two groups in terms of post-surgery BMI (p=0.6793) or EBWL % (p=0.3117).

All of the patients in both groups had an obvious remission of type II diabetes mellitus, with significant improvement in more than 20% and complete resolution in more than 70%, though there was no significant difference between the two groups (p=0.467). There was a significant improvement and complete hypertension resolution observed in both groups, with 32.5% vs. 36.5%, and 63.3% vs. 58.3% (p=0.472). For OSA, all patients in both groups turned out to be low risk, especially with 88.33 % in CLSG group and 94.8% in MLSG group. In addition, the other main co-comorbidities, such as MASLD, polycystic ovarian syndrome, dyslipidaemia and gastroesophageal reflux disease, also got great remission, with most of the patients even got complete resolution after surgery.

There had no significant differences between CLSG group and MLSG group in terms of the baselines of these three kinds of quality of life (QOL) scores, including mental health score, physical health score and total score. Overall, all of the three kinds of mean QOL score in both groups were increased gradually during the two years after surgery vs. baseline. There was no significant difference between these two groups in terms of mental health score, physical health score or total score at one-year and two-year after surgery. However, at six-month after surgery, the mean mental health score, physical health score and total score of MLCG group were significantly higher than that in CLSG group, with mental health score of 65.20±2.588 vs. 59.40±4.219, physical health score of 67.40±3.507 vs. 57.60±3.912, and total score of 69.00±4.583 vs. 60.60±2.608.

The authors acknowledged that the study had some limitations, including the small sample size, the patient experience including mental and physical experience is very subjective and the effect factors are complexed, besides the operative time and length of stay, trocar number, and number of wounds, there probably exists some other factors, which indeed need further research. They concluded that increasing the sample volume and including more centres would provide additional much needed data.

The findings were reported in the paper, ‘Magnetic anchoring device assisted-laparoscopic sleeve gastrectomy versus conventional laparoscopic sleeve gastrectomy: A retrospective cohort study’, published in Heliyon.

To access this paper, please click here


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