To balloon or to suture, that is the question

Obesity is major health concern in the USA, affecting more than 90 million Americans [1]. Because of obesity-related comorbidities, including but not limited to diabetes, heart disease, and cancer, the healthcare costs associated with obesity may account for up to 21 % of US healthcare expenditure [2] [3].

Current therapies for obesity include lifestyle therapy, pharmacotherapy, endoscopic bariatric therapy, and bariatric surgery. Lifestyle therapy alone is the least effective therapy, with only 3 % – 5 % total body weight loss, and instant recidivism [4]. Bariatric surgery is the most effective therapy, showing a reduction in mortality and resolution of diabetes. Unfortunately, only 1 % – 2 % of patients who qualify for bariatric surgery pursue surgical options, most likely because of the risks, costs, recovery time, and food restrictions associated with bariatric surgery [5]. There is increasing hope that minimally invasive endoscopic procedures will fill the treatment gap between medical therapies and bariatric surgery. Such hope requires awareness of endoluminal opportunities.

“Both ESG and IGB placement have the potential to provide an effective therapy for the many patients with obesity, in particular those patients with a BMI between 30 and 40 kg/m²”

In this issue of Endoscopy, Fayad et al. describe a retrospective study aiming to compare the patient demographics and therapeutic outcomes between intragastric balloon (IGB) placement and endoscopic sleeve gastroplasty (ESG) [6]. ESG is a minimally invasive endoscopic procedure using an endoscopic suturing device that has been approved for tissue apposition and is performed with the patient under general anesthesia. This procedure was devised to achieve a reduction in gastric volume, leading to a delay in gastric emptying without resection of the fundus or body of the stomach, and also to provide volume restriction. The IGB balloons used in the study were two different FDA-approved balloons that can be placed by endoscopy for up to 6 months and are filled with saline, also achieving weight loss by inducing a delay in gastric emptying.

The researchers compared the outcomes of 58 ESG procedures and 47 IGB insertions (using either the ReShape Integrated Dual Balloon System [ReShape Lifesciences, San Clemente, California, USA] or the Orbera Intragastric Balloon System [Apollo Endosurgery, Austin, Texas, USA; previously BioEnterics Intragastric Balloon]), which were performed by a single endoscopist at one US center. Patients chose their own therapy. Both groups were enrolled post-procedure into a comprehensive weight management program. The ESG group had greater weight loss at 6 months (20 % vs. 15 % total body weight loss), as well as at 12 months (21 % vs. 14 %), with a lower total adverse event rate (5 % vs. 17 %).

However, there are several limitations of the study that the authors point out; one should interpret the results with caution as these points need to be addressed before generalizing the conclusions. The two groups were not equal: the IGB group had a lower mean baseline body mass index (BMI; 35 vs. 42 kg/m²) and consisted of a higher percentage of women (98 % vs. 59 %) compared with the ESG group. The comorbidities between the groups were also different. These differences make true comparisons between the two procedures difficult.

It is important to note that these groups were not randomized, so there is an inherent selection bias on the part of both the endoscopist and the patient in choosing the therapy. Out-of-pocket costs for each procedure not only influenced decisions but selected patient populations, meaning socioeconomic groups may also differ between the groups.

When dissecting the results, specifically the difference in weight loss between the groups, there are several points important points to be noted. Although the post-procedure follow-up was reportedly similar, it is critical to know whether the actual follow-up office visits and nutrition sessions were similar between the two groups, as studies have shown that greater contact increases weight loss [7] and a more recent study reported no difference in weight loss between different endoscopic modalities when patients had similar follow-up [8].

When looking at the loss to follow-up in both groups, the percentage of patients followed up diminishes, with almost no follow-up recorded for 50 % of the subjects at the 1-year mark. Moreover, one notices that the IGB group were not followed consistently (between 1 – 5 months); however, > 90 % of patients had a follow-up weight recorded at the time of balloon removal, inferring that the reason the percentage of patients followed up increased at that time point was because of the need for the second procedure (balloon removal). The follow-up in the ESG group was also low, with less than 50 % of patients being followed up at the 6 – and 12-month marks. Therefore, the follow-up for both groups is concerning.

Furthermore, the post-procedural diet will not have been similar between the two groups and is not discussed in the manuscript. The ESG diet consists of a modified diet of liquids for about 6 weeks, and the average weight loss is 6 % – 9 % in that first month. The IGB diet however consists of a rapid transition from liquids to soft food. Therefore, one could argue that, by virtue of post-procedural diet alone, the weight loss will not be equal.

Despite these issues with loss to follow-up and post-procedural care, the reported clinical success rates are in line with previously published studies [5] [9] [10]. It important to remember that no randomized sham trials exist that compare sham or lifestyle with ESG.

Although the adverse event rate in this article is consistent with prior studies, it may be unintentionally inflated. In the IGB group, the authors report a 17 % adverse event rate, including nausea and vomiting, known common problems, especially during the early accommodation period. Careful patient selection for potential balloon placement has been identified as reducing tolerance-related adverse events. We do not know if the IGB patients were screened for potential pre-existing motility issues, underwent selective use of gastric emptying studies, or were questioned specifically about medications known to delay gastric emptying, such as anticholinergics and antidepressive psychotropic medications, all of which impact adverse events. The reported rate of adverse events in the ESG group was lower. This may be due to the retrospective nature of the study, meaning mild symptoms or complaints may not be reported, as previous similar studies have reported 15 % – 20 % of patients with abdominal pain and nausea. Such data are critical to determine the comparability of the adverse events between the groups, as well as documenting their severity.

Endoscopic bariatric therapies have expanded our nonsurgical weight loss treatment options and multiple current therapies exist, but there are few comparative data to guide the choice of therapy. Both ESG and IGB placement have the potential to provide an effective therapy for the many patients with obesity, in particular those patients with a BMI between 30 and 40 kg/m², who may not qualify for bariatric surgery. ESG has the advantage of being a single endoscopic procedure, whereas IGB therapy requires two procedures. Short-term therapy with IGB placement can offer value as a bridging procedure, such as to transplantation, and can be an effective treatment for non-alcoholic fatty liver disease (NAFLD) during this time when NAFLD-specific drug therapy is absent.

The optimal endoscopic bariatric therapy is not currently defined, neither have we clearly defined patient characteristics that can help to select patients for a particular therapy. Comparative studies like this one are helpful to enlighten decision-making about which patients are the best candidates. However, significant superiority of ESG over IGB is not supported by the provided analysis. To understand the implications of the device alone, the patient, diet, and the follow-up must be identical. This study is limited by its retrospective, single-center, single-endoscopist design and observed selection bias. Greater experience in careful patient selection and procedure choice for specific indications will be of keen interest to all.

• References

• 1 Sharaiha RZ, Kumta NA, Saumoy M. et al. Endoscopic sleeve gastroplasty significantly reduces body mass index and metabolic complications in obese patients. Clin Gastroenterol Hepatol 2017; 15: 504-510
• 2 Finkelstein EA, Trogdon JG, Cohen JW. et al. Annual medical spending attributable to obesity: payer-and service-specific estimates. Health Aff (Millwood) 2009; 28: w822-w831
• 3 Cawley J, Meyerhoefer C. The medical care costs of obesity: An instrumental variables approach. J Health Econ 2012; 31: 219-230
• 4 Goyal D, Watson RR. Endoscopic bariatric therapies. Curr Gastroenterol Rep 2016; 18: 26
• 5 Alqahtani A, Al-Darwish A, Mahmoud AE. et al. Short-term outcomes of endoscopic sleeve gastroplasty in 1000 consecutive patients. Gastrointest Endosc 2018; DOI: 10.1016/j.gie.2018.12.012.
• 6 Fayad L, Cheskin LJ, Adam A. et al. Endoscopic sleeve gastroplasty versus intragastric balloon insertion: efficacy, durability, and safety. Endoscopy 2019; 51: 532-539
• 7 Lopez-Nava G, Galvao M, Bautista-Castaño I. et al. Endoscopic sleeve gastroplasty with 1-year follow-up: factors predictive of success. Endosc Int Open 2016; 4: E222-E227
• 8 Gontrand Lopez-Nava TL, Fernandez-Corbelle JP, Rull A. et al. 238 comparison of 4 bariatric endoscopy techniques: is there any one better at 1 year?. Gastrointest Endosc 2018; 87: AB67-AB68
• 9 Sartoretto A, Sui Z, Hill C. et al. Endoscopic sleeve gastroplasty (ESG) is a reproducible and effective endoscopic bariatric therapy suitable for widespread clinical adoption: a large, international multicenter study. Obes Surg 2018; 28: 1812-1821
• 10 Lopez-Nava G, Sharaiha RZ, Vargas EJ. et al. Endoscopic sleeve gastroplasty for obesity: a multicenter study of 248 patients with 24 months follow-up. Obes Surg 2017; 27: 2649-2655