Comparison of Three Hypoabsortive Surgical Techniques for Treatment of Type IV Morbid Obesity
Condition: Bariatric Surgery; Morbid Obesity
MeSH terms: Obesity; Obesity, Morbid
Study type: Interventional

Summary: 
      Morbid obesity is the first non-traumatic cause of death in the western population and it is
      also progressively beginning to affect the developing countries. Bariatric surgery provides
      better results than pharmacological treatments and lifestyle changes, granting a better
      control of comorbidities.

      Duodenal switch (DS) has proben to be the most effective surgical treatment for grade IV
      morbid obesity and its comorbidities. However, it is not widely used due to its technical
      complexity and the risk of long-term complications. Single Anastomosis Duodenum-Ileal bypass
      with Sleeve gastrectomy (SADI-S) was concieved in 2007 as a one-anastomosis simplification of
      DS, intended to diminish the surgical time and postoperative risks. Recently, another
      simplified hypo-absorptive technique has started to be widely used: the one anastomosis
      gastric bypass (OAGBP), also called mini-gastric gypass. It consists of a gastric pouch
      associated with a gastro-jejunal anastomosis in omega (Billroth II). Despite the potential
      advantages of these emerging surgical techniques (SADI-S and OAGBP), there is no solid
      evidence on its efficacy for the treatment of grade IV obesity in comparison with DS.
      Besides, there is also there is a lack of studies reporting on prospective acid and bile
      reflux after omega digestive reconstructions, suche as "Billroth II-like" (SADI-S) and
      "Billroth II" (OAGBP). Bile reflux is potentially premalignant condition.

      This prospective randomized study aims to compare conventional DS with SADI-S and OAGBP. We
      include all morbidly obese patients with BMI ≥ 50 kg/m2 aged 18 years or more. Exclusion
      criteria are patients who do not fulfill our preoperative bariatric assessment for surgery
      and those with contraindications for hypo absorptive or mixed surgery.

      The main objective of the study is to compare the percentage of excess weight lost at 2 and 5
      years after the three different surgical procedures. As a secondary objective,
      gastroesophageal reflux (GERD) will be compared before and 2 years after surgery, based on
      GERD symptoms test, gastroscopy and a esophageal pH-impedanciometry in selected patients.
      Other secondary objectives are comparison of short-term complications, metabolic
      comorbidities, depositional habit, quality of life and metabolic and nutritional deficiencies
      at two years of surgery.
    

Detailed description: 
      Morbid obesity is the first non-traumatic cause of death in the western population and it is
      also progressively beginning to affect the developing countries. Bariatric surgery provides
      better results than pharmacological treatments and lifestyle changes, granting a better
      control of comorbidities.

      Duodenal switch (DS) has shown to be the most effective surgical treatment for morbid obesity
      and its comorbidities. However, it is not widely used due to its technical complexity and the
      risk of long-term complications. In 2007 Drs. Sánchez-Pernaute and Torres introduced a
      simplified version of the DS technique: Single Anastomosis Duodenum-Ileal bypass with Sleeve
      gastrectomy (SADI-S). SADI-S consists of a vertical gastrectomy (VG) and a duodenum-ileal
      anastomosis preserving the pylorus with jejunal exclusion and a total common-alimentary loop
      originally of 200 cm and later standardized to 300 cm to reduce the risk of nutritional
      deficits. In order to diminish the surgical time and postoperative risks an omega
      reconstruction is performed without an ileo-ileal anastomosis. SADI-S can be performed either
      directly as primary surgery, planned in two stages, or as revisional surgery in case of
      insufficient weight loss or weight regain after VG. In terms of weight loss and comorbidity
      resolution, SADI-S' reported results are similar to those reported in historical DS series,
      but no prospective comparative studies have been published.

      Recently, another simplified hypo-absorptive technique has started to be widely used: the one
      anastomosis gastric bypass (OAGBP), also called mini-gastric gypass. It consists of a gastric
      pouch associated with a gastro-jejunal anastomosis (Billroth II). It was initially described
      by R. Rutledge in 1997 and despite its first publication was in 2001, only lately it has been
      approved as a standard bariatric technique. OAGBP with a 200 cm biliopancreatic limb has
      shown good results in weight loss and control of comorbidities, higher than those achieved by
      VG and proximal Roux-en-Y gastric bypass (RYGBP) with 50 cm biliopancreatic limb and 150 cm
      alimentary limb, as it has been demonstrated in two prospective randomized studies and a
      recent meta-analysis. However, the OAGB results have not been compared with other hypo
      absorptive surgical techniques, such as DS or SADI-S.

      In comparison to the DS, which has a Y-Roux reconstruction, SADI-s and OAGBP have a "Billroth
      II-like" or omega reconstruction. Despite the potential advantages of these emerging surgical
      techniques, bile reflux is the main issue of omega reconstructions. In our most recently
      published series including 440 consecutive patients, we reported that 1.7% of patients
      required conversion to DS due to symptomatic bile reflux. It would be reasonable to expect
      higher incidence of bile reflux in techniques with omega reconstruction that do not preserve
      the pyloric barrier, such as OAGBP. However, some authors claim that with a 200 cm
      biliopancreatic limb most of the bile is reabsorbed by the intestine before it reaches the
      gastro-jejunal anastomosis. This would minimize bile reflux in comparison to the historical
      series of Billroth II reconstruction after gastrectomy for oncological or peptic disease (in
      which the biliopancreatic loop is much shorter, generally around 50 cm). Reported incidences
      of symptomatic bile reflux after OAGBP vary between 0.5% and 1.5%, comparable to our SAID-S
      results. It is worth mentioning that not all bile refluxes are symptomatic and that biliary
      gastritis is a premalignant condition. At present, there is a lack of literature on acid and
      bile reflux after bariatric surgery comparing the 3 digestive reconstruction techniques: (i)
      Roux-en-Y with pyloric preservation (DS), (ii) omega reconstruction with pyloric preservation
      or "Billroth II-like" (SADI-S) and (iii) omega reconstruction without pyloric preservations
      or Billroth II (OAGBP).

      This prospective randomized study aims to compare conventional DS with SADI-S and OAGBP. We
      include all morbidly obese patients with BMI ≥ 50 kg/m2 and candidates to a directly DS
      following our treatment algorithm. Exclusion criteria are patients who do not fulfill our
      preoperative bariatric assessment for surgery and those with contraindications for hypo
      absorptive or mixed surgery.

      The main objective of the investigation is to compare the percentage of excess weight lost at
      2 and 5 years after the three different surgical procedures. For the study of weight
      evolution, both Dietetics' and General Surgery's postoperative standardized routine controls
      at our outpatient centre will be used.

      As a secondary objective, gastroesophageal reflux (GER) will be compared before and 2 years
      after surgery. A GER's symptoms test, gastroscopy and a esophageal pH-impedance analysis in
      selected patients will be employed. Other secondary objectives include the comparison of
      short-term complications, metabolic comorbidities, bowel habit and quality of life two years
      after the surgical procedure. Furthermore, a medium and long term follow up on metabolic and
      nutritional deficiency will be performed.

      For the morbidity and mortality analysis, the patients' electronic medical history records
      will be revised. Short postoperative complications (up to 30th postoperative day) will be
      classified according to Clavien-Dindo classification. Comorbidities' evolution will be
      evaluated following our centre follow-up protocol before and annually after the surgery. Data
      will be collected in a prospective database. The quality-of-life study will be carried out
      with the SF-12 test. The metabolic and nutritional deficit analysis will be carried out
      through the annual analytical data collected during the follow-up of the patients according
      to common clinical practice.
    

Intervention name(s): DS vs. SADI-S vs. OAGBP
Intervention type(s): Procedure
Intervention description(s): Randomizacion of candidates for either conventional DS, SADI-S or OAGBP.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Prospective randomized study comparing three bariatric surgical techniques
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: Bariatric Surgery; Morbid Obesity; Hypoabsortive surgery; Duodenal Switch; SADI-S; One-anastomosis gastric by-pass; Gastro-esophageal reflux