The Great Debate: Medicine or Surgery

What Is Best for the Patient With Type 2 Diabetes?

David Lautz, MD; Florencia Halperin, MD; Ann Goebel-Fabbri, PHD; Allison B. Goldfine, MD

Disclosures

Diabetes Care. 2011;34(3):763-770. 

In This Article

Bariatric Surgical Procedures

When either recommending surgery to a patient or designing a trial, it is important to consider which surgical procedure to select. There are several options.

The LAGB is a commonly chosen bariatric surgical procedure in the U.S. and has a highly acceptable safety risk profile, making it attractive for less obese patients as an alternative to medical therapy. Thirty-day mortality was zero in 1,198 patients who underwent LAGB placement.[41] Most surgical studies report results as mean percent excess body weight loss calculated as the percent of body weight above Metropolitan Life table "ideal",[42] or alternatively BMI of 25 kg/m2. The mean percent excess body weight loss after LAGB in published series is 46%, and the mean resolution in diabetes is 56%,[2] both substantially lower than after RYGB.[2] Studies that directly compare the RYGB and LAGB also suggest substantially greater weight loss and resolution of comorbidities after RYGB.[43] There are no studies to date suggesting that the LAGB has a specific effect on type 2 diabetes beyond that of inducing caloric restriction and subsequent weight loss. However, as noted above, the only level 1 data comparing medical with surgical interventions specifically for the treatment of type 2 diabetes evaluates LAGB as the surgical procedure. Dixon et al.[6] randomized patients recently diagnosed with type 2 diabetes (diagnosis ≤2 years) with BMI 30–40 kg/m2 (inclusive of some patients whose weight was below current bariatric surgical criteria) to LAGB or an intensive lifestyle modification with medical management, and demonstrated surgically treated patients were more likely to achieve diabetes "remission" (defined as fasting glucose level <126 mg/dL and glycated hemoglobin <6.2% without glycemic therapy) (73 vs. 13%, P < 0.001), with a 5.5 relative risk for remission in the surgically treated group. Notably, the magnitude of weight loss achieved in this study substantially exceeds that typically realized in U.S. clinical practice.[2] Whether with similar techniques and management algorithms the same level of results can be attained in a less obese population with type 2 diabetes in the U.S. remains unknown. The LAGB seems to have the lowest complication and adverse outcome rate among commonly performed bariatric surgical procedures.[41,43] More frequent complications of LABG include gastric erosion or perforation, band slippage or migration, esophageal dilation, port problems, incisional hernias, and acute respiratory distress and pulmonary embolism.[44] Therefore, despite the lack of evidence for a specific effect, with a low-risk profile and impressive results from Dixon and colleagues' prospective randomized series, the LAGB certainly is an attractive therapeutic option. Although, it is important to note that the band will require adjustments, potentially over the patient's lifetime.

The RYGB is also a commonly performed procedure, and despite the lack of randomized clinical trials comparing RYGB with medical intervention, much of the enthusiasm for expansion of BMI criteria for bariatric surgical procedures in type 2 diabetic patients has been fueled by RYGB outcomes demonstrated in multiple large observational studies that show improvement or resolution of diabetes in 80% of patients who undergo this procedure.[2] Despite early concerns over safety profiles, the laparoscopic RYGB has been judged to be an extremely safe procedure. Estimates of early operative mortality, defined as mortality at 30 days or less, vary, but in general are at 0.1–0.33%,[4,45] and this has been supported by a recent large prospective multi-institutional trial involving 2,975 laparoscopic RYGB procedures, showing a 0.2% 30-day postoperative mortality rate.[41] Higher rates exist for open RYGB, with elderly patients and with less experienced surgeons.[46] Complications of RYGB can occur in up to 10% of patients. Other risks include reoperation during the same admission in 6–9%; technical complications, including obstruction, anastomotic, hemorrhagic, wound, and splenic injury in 1–2%; and systemic complications in 3–7%, which most commonly involve the pulmonary system.[4] In addition, the rate of overall hospital admissions in the year after RYGB surgery may be increased twofold, with most admissions for gastrointestinal or surgical-related complications.[45] Many of these risks are continuing to diminish over time with the increasing prevalence of laparoscopic techniques and growing clinical experience and prevalence of bariatric surgical centers of excellence.[47] As discussed above, there is mounting evidence that improvement or resolution of diabetes after RYGB includes mechanisms beyond weight loss alone. Although there are no randomized controlled trials of RYGB compared with nonsurgical interventions, the proven effectiveness and safety profile cautiously support the preferential use of this procedure specifically for type 2 diabetes treatment.

It is important to note there are variations in the specific surgical techniques of the RYGB procedure. These include concomitant vagotomy or vagal-sparing maneuvers[48] at the time of RYGB, as well as variable limb length. With regard to limb lengths, a "standard limb length" RYGB procedure includes a 30–50 cm pancreaticobiliary limb and a 75–100 cm Roux limb.[49] Lengthening the pancreaticobiliary and Roux limbs to 150 cm significantly increases malabsorption and potential complications.[49] Thus, outcomes after RYGB need to be interpreted with differences in surgical technique taken into account.

Several other bariatric surgical procedures options exist. The biliopancreatic diversion and duodenal switch are extremely effective at reducing weight and hyperglycemia but have documented higher perioperative mortality rates and induce substantial malabsorption,[50] which are less appropriate for a population with lower BMI. The laparoscopic sleeve gastrectomy (LSG) is a newer procedure that is rapidly gaining favor nationally. To date, most studies using this procedure on less obese type 2 diabetic patients have been in conjunction with ileal interposition, which significantly increases the complexity of the operation but may contribute positively to effects on the incretin axis.[51] Rapid adoption of the LSG technique in many centers throughout the U.S. is likely to provide relevant data in the near future, and as such, going forward, the LSG may be an important option to be considered in clinical trials.

Novel procedures that have been designed specifically to address type 2 diabetes include the ileal interposition and the DJB, mentioned above.[25] However, there are insufficient human clinical data to justify using them broadly at this time. The DJB involves division and anastomosis of the duodenum and thus also likely carries a higher risk for perioperative morbidity and mortality.[52]

Finally, minimally invasive devices, such as the intraluminal duodenal sleeve, have been demonstrated in preclinical models to effectively reduce weight without malabsorption and improve oral and intraperitoneal glucose tolerance.[53] Early clinical trials suggest similar devices may promote weight loss and glycemic improvements in patients with type 2 diabetes.[54]

Differences in surgical approaches must be considered when weighing the most appropriate intervention at this time either for individual therapy or for study in a prospective trial evaluating surgical approaches directed at type 2 diabetes. To change practice guidelines to use bariatric procedures in lesser degrees of obesity and earlier in the course of diabetes, specifically for diabetes treatment, studies must be conducted to compare surgical with medical management. From a trial perspective, consideration as to the type of surgical procedure(s) to include must also hinge on currently accepted insurance practices. It is unlikely larger trials would have sufficient funding to bear the entire clinical cost of the surgical procedures, and thus would have to rely on some of the clinical costs being covered by multiple funding agencies, including insurers, to successfully complete a large adequately powered outcome study.

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