The advent of bariatric surgery and its widespread adoption created a wide patient pool undergoing elective surgery in a high-risk population. As the number of these procedures increased, so did the direct cost to payers. Both private insurers and the Centers for Medicare and Medicaid Services initially drove the need to objectively identify high-quality providers by requiring centers performing bariatric surgery to be accredited, using their own specific criteria.

As this occurred, surgeons viewed this opportunity to support accreditation in order to build a quality system that could be used to improve patient care by providing widespread data for both scientific investigation and quality improvement projects. Even if some of the provider dynamics have recently changed, surgical quality and accreditation programs have been very successful and widely adopted. In bariatric surgery, the two main providers of accreditation—the American College of Surgeons (ACS) and the American Society for Metabolic and Bariatric Surgery (ASMBS)—have merged their accreditation system to create the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) in 2013 [1]. MBSAQIP has recently released the inaugural standards for their joint accreditation program, and their requirement will be summarized later in this chapter.

Besides the different requirements needed for a particular accreditation, the role and benefit of accreditation itself as a quality metric have been recently debated. Indeed, after having initiated the accreditation requirement for bariatric surgery, CMS (the Centers for Medicare and Medicaid Services) has recently reversed their policy regarding bariatric centers of excellence and no longer require accreditation to perform these procedures. However, the majority of studies published since the implementation of facility certification for bariatric surgery have demonstrated improvement in outcomes.

These studies have shown:

Some studies do suggest that accreditation by itself does not directly improve outcomes, but other metrics like surgeon or institution volume, potentially imbedded in accreditation, are actually more accurate in evaluating quality [8, 9]. They did confirm, however, a relationship with hospital volume, a metric in all accreditation programs including the Michigan Collaborative. In addition, the recent publication by Jafari et al. demonstrated a benefit for bariatric surgery outcomes rendered by accreditation that is independent of volume status [10]. Also, in a 2014 American Surgical Association presentation by Morton et al., a precise advantage of accreditation was demonstrated by accredited centers having superior rates of “failure to rescue” than nonaccredited centers [11]. This advantage makes intuitive sense in that experienced centers with appropriate personnel and resources can readily recognize and treat complications before any potentially fatal event.

As mentioned previously, MBSAQIP has recently released the inaugural standards for their joint accreditation program, (http://​www.​mbsaqip.​org/​docs/​Resources%20​for%20​Optimal%20​Care%20​of%20​the%20​MBS%20​Patient.​pdf).

The requirements for accreditation fall under nine standards and essentially define two tiers in general bariatric accreditation: low-acuity centers and comprehensive centers.

Low-acuity centers perform a minimum annual volume of 25 approved metabolic and bariatric stapling operations on low-acuity patients: i.e., adults under the age 65, males with a BMI < 55 and females with a BMI < 60, and those who do not have either organ failure or history of organ transplant. These centers are not accredited to perform non-emergent revisional procedures but can perform all other approved bariatric procedures in this specific patient population. Comprehensive centers may perform all approved procedures including high-risk patients as well as revisional procedures.

Of the 9 described standards, 7 are core standards and 2 pertain to specific patient age (i.e., adolescents) or procedures (gastric banding). The 7 core standards are applicable to both tiers of accreditation. The differentiation in low-acuity vs. comprehensive centers is solely based on volume: low-acuity centers need to perform a minimum of 25 bariatric stapling cases per year, whereas comprehensive centers are required to perform at least 50 cases annually.

The 7 core standards are:

Standard 1: Case volume—see above

Standard 2: Commitment to quality care

Standard 3: Appropriate equipment and instruments

Standard 4: Critical care support

Standard 5: Continuum of care

Standard 6: Data collection

Standard 7: Continuous quality improvement process

If national guidelines have been used to frame the indications for bariatric surgery, they remain vague as to evaluating patients in order to safely provide the best surgery to each patient. Current National Institutes of Health (NIH) guidelines for bariatric surgery date back over 20 years—1991 consensus conference on gastrointestinal surgery for severe obesity [12]—and do not provide guidance toward adequate patient evaluation. These guidelines require a BMI > 40 or a BMI > 35 and either high-risk comorbid conditions such as life-threatening cardiopulmonary problems, severe diabetes mellitus, or obesity-induced physical problems interfering with lifestyle. They state that patients should be able to demonstrate failed attempts at diet and exercise, be motivated and well informed, and be free of significant psychological disease.

The extent of the preoperative workup in order to assist patient/procedure selection is therefore extremely variable depending on the provider. In our view, an extensive preoperative multidisciplinary workup is necessary to assess the extent of each patient’s comorbidities and guide appropriate preoperative management or procedure selection. Details of the preoperative evaluation are presented in the previous chapters.

The relationship between institution or surgeon volume and outcome has been widely held for multiple complex surgical procedures, and bariatric surgery is no exception. Multiple studies have demonstrated a relationship between outcomes and volume, with reduction in morbidity and mortality in high-volume centers. A recent systematic review covering 24 studies and over 450,000 patients confirmed this association for both institutions and surgeons. While this relationship holds true on average, it does not fully account for outcomes—this will be discussed later in this chapter (composite measures)—and some low-volume centers can have good outcomes or vice versa [2, 10, 13, 14].

An interesting aspect of volume-outcome metrics is the threshold chosen for the determination of low- vs. high-volume centers. When the first accreditation programs for bariatric surgery were established, in 2004–2005, the threshold was somewhat arbitrarily defined at 125 cases/institution/year for the centers of excellence. Today, top tier accreditation as comprehensive center requires less than half that number, and only 25 cases/year are necessary to receive low-acuity center accreditation. The current standards specify that these need to be stapling procedures. This trend is actually supported by the literature: most studies analyzing volume outcomes in bariatric surgery have either chosen 25 cases/year or 50 cases/year as their cutoff for high-volume centers and have demonstrated improved outcomes in the defined high-volume centers. It also demonstrates the enhanced safety profile of bariatric surgery over time and the impact of stapled procedures upon morbidity. Recently, Jafari et al. have studied the Nationwide Inpatient Sample reviewing laparoscopic cases between 2006 and 2010, using the new criteria (> 50 stapling procedures per year): they have demonstrated a 2.5-fold increased mortality rate in low-volume centers. This new threshold could therefore improve access to care while preserving outcomes [10].

One aspect in the improvement of bariatric surgery outcomes is the widespread adoption of laparoscopy: from < 2 % of procedures in 1998 to over 90 % today [15]. If the exact role of laparoscopy in the improvement of outcomes is difficult to quantify, multiple studies have demonstrated the benefits of laparoscopy, both for these procedures and for this specific patient population. By far, the most thoroughly studied procedure is the gastric bypass. From early randomized control trials to large nationwide cohort analysis with > 100,000 patients, studies have demonstrated a wide range of benefits to the laparoscopic approach [16–19]. They include reduced mortality (up to 50 % lower) and morbidity (reduced by a third) and shorter length of stay but also reduced overall cost while maintaining equivalent or better long-term weight loss. Laparoscopy also resulted in the virtual disappearance of wound-related complications such as wound infection (> 10 % in open gastric bypass) or incisional hernia (> 7 % in open gastric bypass).