Laparoscopic Adjustable Gastric Banding and Type 2 Diabetes

| March 22, 2010

An Interview with Jaime Ponce, MD, FACS, FASMBS

Dr. Ponce is the Medical Director for the Bariatric Surgery program at Hamilton Medical Center, Dalton, Georgia and Memorial Hospital, Chattanooga, Tennessee. He is the Chair of the ASMBS Insurance Committee, Vice-President of the ASMBS Tennessee State Chapter, and Member-At-Large of the ASMBS Executive Council. Dr. Ponce has extensive experience with the laparoscopic adjustable gastric band procedure.

Bariatric Times. 2010;7(3):16–17

Financial disclosures: Dr. Ponce was a principal investigator for the FDA “C” trial with the Lap-Band® and the U.S. Realize™ Band clinical trial, and uses both bands in his private practice.

As prevalence of obesity continues to rise world-wide, so too does the prevalence of type 2 diabetes (T2D). The staff of Bariatric Times interviewed Dr. Jaime Ponce, an expert on the laparoscopic adjustable gastric band (LAGB), for his opinion on the use of LAGB for treatment of T2D, particularly in patients with lower body mass index (BMI).

What is the approximate percentage of the population that could benefit from diabetes resolution with weight loss surgery?

Diabetes now affects nearly 24 million people in the United States, an increase of more than three million in approximately two years, according to 2007 prevalence data estimates released by the Centers for Disease Control and Prevention (CDC).[1] This means that nearly eight percent of the United States population has diabetes.

In addition to the 24 million with diabetes, another 57 million people are estimated to have pre-diabetes, a condition that puts people at increased risk for diabetes. Also, according to the CDC, more than 30 percent of the United States population is obese, with approximately 4 to 5 percent being obese with diabetes: these individuals can potentially benefit from weight loss surgery.

How do you see the Dixon landmark study on gastric banding and diabetes resolution affecting United States Food and Drug Administration (FDA) approval of LAGB for treatment of T2D in patients with lower BMI?

The Dixon study2 is the first randomized study that compares medical versus surgical therapy for type 2 diabetes (T2D). This study included patients with obesity class I and II who had T2D for less than two-years duration, and the results showed a significant difference in resolution (13% vs. 73%) favoring the surgical treatment. The resolution was very dependant on weight loss, and there was significant evidence that for moderate obesity, LAGB can provide significant weight loss with improvement and resolution of diabetes and metabolic syndrome. At present, there is an ongoing FDA-monitored trial using the Lap-Band® (Allergan, Inc., Irvine, California) on patients with moderate obesity (BMI: 30–40kg/m[2]), and the results should be available in the near future. The FDA should look at other studies, such as the prospective, randomized study by O’Brien et al[3] published in May of 2006 in Annals of Internal Medicine comparing medical versus weight loss surgery in patients with moderate obesity. O’Brien et al showed the safety and effectiveness of the band with a high level of evidence.

My prediction is that the Lap-Band® will be FDA approved for use in this lower BMI population, which is in significant need for alternative therapies.

What can you tell us about the APEX trial related to excess weight loss?

The APEX trial[4] is a multicenter, institutional review board (IRB)-monitored trial using the new Lap-Band® AP in 44 centers with 508 patients enrolled in a prospective manner with five-year follow up. There will be an enormous amount of data that will be obtained. Early results presented during the last American Society for Metabolic and Bariatric Surgery (ASMBS) meeting revealed an excellent excess weight loss (EWL) at 6 and 12 months of 34 and 47.5 percent, respectively. This is the kind of study we clinicians have been requesting the industry to sponsor in order to obtain data on their products. Nowadays, it is very important for new companies to not only release new products, but to be supportive in documenting the effectiveness of the new devices.

Like any other study in the United States, I will suspect that at five years we will have some patients lost to follow up, but we believe valuable information will be obtained regarding the new version of this band. Perhaps the data will establish the advantages that the modifications to the device have provided. Studies on the new Realize™ Band-C are also needed.

What are the benefits of using LAGB for the treatment of T2D compared to bypass surgery?

LAGB has been proven to be an effective treatment for T2D in patients with obesity, especially in patients with less severe disease and shorter duration. In our personal experience, we have seen a significant positive difference in diabetes resolution when the diabetes is less than five-years duration and the weight loss is good. Better weight loss is usually achieved in patients with lower BMI (compared to those with higher BMI), and, in general, patients with diabetes lose less weight than patients with no diabetes. Our experience with the band and Schauer’s[5] experience with the bypass have demonstrated this.

Patients with diabetes in general may have a higher chance to develop complications following any surgical procedure, especially patients with no optimal glycemic control. I believe LAGB is a safer procedure than the bypass, potentially adding a benefit in the perioperative outcome. Otherwise, both procedures in general are very effective in the hands of experienced centers. The bypass may offer additional benefits in patients with more severe diabetes or patients who are insulin users by helping those patients have a faster and better resolution associated with an initial greater weight loss and some theoretical benefits of the gastrointestinal (GI) hormonal changes.

Is there a difference in the remission rate of T2D in patients with a lower BMI compared to patients with a higher BMI who have undergone LAGB? If so, why?

I think in any procedure there is always a difference in weight loss and diabetes resolution when we compare patients with super obesity to patients with morbid obesity. Patients with super obesity are, in general, more resistant to weight loss; therefore, the more malabsorptive procedures can offer an advantage in these patients. Usually, with LAGB, these weight loss-resistant patients require a longer commitment to lose weight, compared to patients who undergo bypass procedures, and a more intense follow up is required with LAGB that sometimes is not adhered to by the patient. Less weight loss in these more difficult patients will ultimately be associated with less resolution of diabetes.

Unfortunately, there are not a lot of studies in the super obese population, but in my experience, these patients will require significant commitment in order to get the best results with LAGB. In addition to more resistant obesity, the patient’s motivation and other potential barriers, including lack of insurance coverage for follow-up, may be the reasons why these patients may not do as well compared to lower BMI patients.

What is the difference in remission rate of T2D in patients who have undergone LAGB compared to bypass? Why is there a difference?

According to the latest systematic review of the literature by Buchwald et al[6] published last year in the American Journal of Medicine, diabetes resolution was greatest for patients undergoing gastric bypass (70.9%) compared to LAGB (58.3%), with two years or more of follow up data.

Two factors can be identified that make this difference. First, the data showed a difference in weight loss with both procedures, with bypass having 63 percent EWL versus 49 percent in band procedures after more than two years of follow up. Better weight loss has been shown to be a factor that influences better diabetes resolution. In my own series, patients with LAGB that had better weight loss had significantly better diabetes resolution rate and O’Brien et al[3] have confirmed this finding as well. Second, it has been observed that the manifestations of T2D can totally clear within days after gastric bypass in about 30 percent of the patients, according to Schauer’s[5] experience, before there is any significant weight loss and after the immediate effect of postoperative starvation on the blood glucose level has dissipated. This finding would suggest that changes in the gut hormonal milieu after bypass of the distal stomach, duodenum, and proximal jejunum can influence the mechanism of T2D, changes that do not exist in the LAGB procedure. Substantiation of this hypothesis comes from the studies of Rubino,[7] who demonstrated that a bypass of the duodenum and upper jejunum in lean diabetic rats would return them to euglycemia, even though they maintained normal weight

So it has been recognized that bypass surgery resolves T2D more quickly, but does the diabetes come back or get worse if bypass patients gain their weight back?

Even though gastric bypass has an initial stronger effect on diabetes, with approximately 30 percent of the patients stopping all medications, I believe that the longer effect on diabetes will be more dependant on weight loss and reduced caloric intake. Clinically, patients that regain weight with any procedure and previously had diabetes may have some recurrence in the need for medications to control hyperglycemia. This finding seemed to occur also in bypass patients who previously had diabetes and then regained weight. Anecdotically, however, this diabetes that reoccurs post-surgery with weight regain, is much more easily controlled. Unfortunately, there are no good studies that establish the frequency and severity of diabetes “recurrence” after bypass weight regain.

What is the mechanism of action of LAGB for resolution of T2D?
The resolution of T2D in LAGB patients is very dependant on weight loss, reduced caloric intake, and preoperative duration of the disease. The long-term maintenance of this resolution will ultimately be associated with long-term weight loss. Our experience showed that patients with diabetes who underwent LAGB and had resolution of T2D in general were patients that achieved more than 45 to 50 percent EWL and had less than five years preoperative duration of diabetes. Patients with weight loss less than 25 percent and with more than five-year duration of diabetes had significantly less resolution of the disease.[8]

What is the average time to complete resolution of T2D in patients undergoing LAGB?
This is a complex question to answer because LAGB patients have shown significant variability in weight loss completion, which depends on preoperative BMI, adherence, band functionality, and tolerance to the restriction. Diabetes resolution may take 1 to 4 years depending on weight loss completion.

Is there an ideal candidate for LAGB?

I think the ideal candidate who can maximize the benefits of the LAGB is a patient with severe or morbid obesity in the lower BMI category that has the ability to understand the band and the eating behavior needed; has no financial, geographic, or personal barriers for adherence; and participates in an experienced and intensive gastric band follow-up program led by an experienced band surgeon. In addition, a younger patient with the ability to establish consistent exercise will have added chances for success.

Of course, this is ideal for any weight loss procedure, but the band may become more dependant on some of the follow-up needs long-term, which become critical for success in patients with higher BMI.

What is the protocol for using fluoroscopy with banding patients?

Band adjustments can be done with fluoroscopic guidance, but the need for adjustments still need to follow the eating zones criteria suggested by O’Brien et al.[3] If we determine that a band patient needs an adjustment, fluoroscopy can assist in different ways: It can facilitate accessing a port that is difficult to palpate; it can help with the evaluation of the band position and orientation; it can help with assessment of the pouch anatomy; it is useful in evaluation of the presence of a hiatal hernia, esophageal dilatation, and stoma tightness; and it even can be used to address incidental asymptomatic findings of advanced erosions.

If a patient is in the “yellow zone” and barium flows easily through the stoma without any other significant abnormality, we can tighten the band while the patient is in the upright position, slowing the barium flow without causing obstruction or significant reflux. Then, the patient will still need to tolerate water before the adjustment is completed. This approach is especially helpful during the first adjustments to get them into the “green zone.”

One of the most important clinical advantages of fluoroscopy is when the patient presents in the “red zone.” It is extremely helpful if fluoroscopy is easily accessible to evaluate a list of differential diagnoses that include slippage, stoma gastritis, hiatal hernia, or just stoma tightness.

What trends do you see in the single-incision laparoscopic surgery approach to LAGB?

The single-incision laparoscopic surgery (SILS) approach for LAGB is a more difficult laparoscopic approach because only one incision is being used, new skills and instrumentation may have to be adapted, and a learning curve may have to be accomplished.

This approach has gained popularity with some surgeons who are trying to demonstrate that laparoscopic surgery can be as “cosmetic” as natural orifice approaches. It is also being used as a “marketing tool” to promote a more cosmetic approach to this procedure, and the industry is being stimulated to develop and create new multi-instrument access ports and flexible/articulating instrumentation and scopes to facilitate the technique.

Many surgeons still question the clinical advantages of this approach and raise the question of safety and ability to accomplish the same procedure in more difficult cases or by less skilled surgeons. Definitively, this approach may not be indicated for patients that are more complex (e.g., have large hiatal hernias, large livers, or significant adhesions), and surgeons should not attempt to complete the procedure by one incision if safety is compromised.

The industry and some surgeons may have responded to the demand for courses, but I think they are also “pushing” a technique and approach that some less skilled surgeons may feel forced to adopt. Marketing can also drive this procedure by patients if they are not well informed and can potentially make them spend more unnecessary time in the opersting room or have a less than optimal procedure.

The trends I see are an increased demand from surgeons to attend courses and participate in some kind of preceptorship; also the industry may facilitate this procedure and may increase the demand for training and use of their products. But the rate of adoption is still low and localized to certain regions in the country. Both surgeons and industry should be careful to not endorse cosmetics over safety.

References
1.    2007 National Diabetes Fact Sheet. http://www.cdc.gov/diabetes/pubs/estimates07.htm#1. Access date: March 15, 2010.
2.    Dixon JB, O’Brien PE, Playfair J, et al. Adjustable gastric banding and conventional therapy for type 2 diabetes: a randomized controlled trial. JAMA. 2008;299(3):316–323.
3.    O’Brien PE, Dixon JB, Laurie C, et al. Treatment of mild to moderate obesity with laparoscopic adjustable gastric banding or an intensive medical program: a randomized trial. Ann Intern Med. 2006;144(9):625–633.
4.    Hansen D, Michaelson R, Ehrlich T, James S. P-15: Clinical evaluation of the Lap-Band AP® System in the severely obese: interim analysis of the APEX study. SOARD. 2009;5(3, Suppl):S28–S29)
5.    Schauer PR, Burguera B, Ikramuddin S, et al. Effect of laparoscopic Roux-en-Y gastric bypass on type 2 diabetes mellitus. Ann Surg. 2003;238:467–485.
6.    Buchwald H, Estok R, Fahrbach K, et al. Weight and type 2 diabetes after bariatric surgery: systematic review and meta-analysis. Am J Med. 2009;122(3):248–256.e5.
7.    Rubino F, Forgione A, Cummings DE, et al. The mechanism of diabetes control after gastrointestinal bypass surgery reveals a role of the proximal small intestine in the pathophysiology of type 2 diabetes. Ann Surg. 2006;244:741-749.
8.     Ponce J, Haynes B, Paynter S, et al. Effect of Lap-Band-induced weight loss on type 2 diabetes mellitus and hypertension. Obes Surg. 2004;14:1335–1342.

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