Ileal interposition with sleeve gastrectomy for treatment of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) and obesity have reached epidemic proportions in many countries throughout the world. The global prevalence of diabetes among adults (aged 20–79 years) was estimated at 6.4% in 2010 and is projected to increase to 7.7% by 2030.[1] Currently, India has approximately 50.8 million diabetes patients[2] and the number is slated to increase to 80.9 million in the year 2030.[3] The World Health Organization (WHO) stated that in 2005, an estimated 1.6 billion adults in the world were overweight and at least 400 million were obese.[4] They also predicted that by 2015, 2.3 billion adults would be overweight and >700 million of them will be obese.[4]

Further, diabetes and obesity are strongly linked and often coexist. When coupled together, this diabesity[5] imparts an additive risk and accelerates the progression of cardiovascular complications.[6] To help curb the increasing burden of these diseases on the world health economy, researchers are continually exploring newer methods for achieving sustainable weight loss and remission of diabetes.[5]

Bariatric surgery has evolved as a double-edged tool to manage obesity and related comorbidities like diabetes, hypertension, and hyperlipidemia. Following bariatric surgery, glycemic improvement starts earlier and is disproportionately more than weight reduction.[7] Glycemic improvement is more with malabsorptive surgeries [Roux-en-Y (R-n-Y) gastric bypass and biliopancreatic diversion (BPD)] than with restrictive surgeries (gastric band).[8] Ileal interposition in combination with sleeve gastrectomy (II + SG) is a novel procedure that offers equal metabolic benefit without causing any malabsorption.[9] This has lead to the concept of metabolic surgery. Information about this procedure is available on animals including rats, dogs, and porcine models.[1016] Though sufficient information is available in literature regarding the efficacy of this novel procedure (II + SG) in the treatment of T2DM,[1722] Indian data regarding this procedure are scarce.[18,22] In our recently published report, we evaluated the preliminary results of II + SG treatment and demonstrated its feasibility, safety, and efficacy in T2DM.[18] However, since those findings were based on a small study sample of 10 patients and a short-term follow-up; further long-term data including more number of patients were warranted. All over the world, this procedure is performed in obese as well as nonobese T2DM patients.[1921,23] We too were inspired to include selected nonobese T2DM patients in our current study. We hereby report the results of II + SG treatment in 43 T2DM patients, with a follow-up of 3 years.

MATERIALS AND METHODS

We started this non-randomized, prospective case series to evaluate the effects of II + SG at our center, Kirloskar Hospital, Hyderabad, India, in February 2008. The hospital's ethical committee approved the study, and all patients provided written informed consent after being informed thoroughly about the benefits and risks involved. Nonobese patients were specifically explained about potential benefits of the surgery and limited data available about this procedure for nonobese diabetic patients.[1921,23] Nonobese patients were included selectively on the basis of poor glycemic control despite optimum dosage of insulin ± oral hypoglycemic agents (OHAs), good post-meal C-peptide response, and after exclusion of type 1 diabetes patients and underweight patients with body mass index (BMI) <18.5 kg/m2. We report the data of all the 43 patients, who were operated upon and analyzed till July 2011.

Inclusion and exclusion criteria

The inclusion criteria were patients having T2DM of more than 1 year duration, with age between 25 and 70 years, stable weight for the last 3 months (variation in weight <3%),[1921] BMI ≥18.5 kg/m2, and stimulated C-peptide level >1.5 ng/ml.

The exclusion criteria were type 1 diabetes mellitus, undetectable fasting C-peptide, positive urine ketones, pregnancy, and coexisting severe hepatic, pulmonary, renal, cardiovascular, neurological, and psychiatric diseases, and obesity due to organic illness.

Subjects and preoperative evaluation

Preoperative evaluation included clinical history of T2DM, comorbidities, and complications, followed by thorough physical examination. Patients were diagnosed to have T2DM on the basis of fasting plasma glucose ≥126 mg/dl (fasting is defined as no caloric intake for at least 8 h) or 2-h plasma glucose of ≥200 mg/dl during an oral glucose tolerance test after using a glucose load containing the equivalent of 75 g anhydrous glucose dissolved in water or a random plasma glucose of ≥200 mg/dl in a patient with classic symptoms of hyperglycemia or hyperglycemic crisis.[24] Standing height was measured using a portable stadiometer (Leicester height meter; Child Growth Foundation, UK; range 60–207 cm). Weight was measured using an electric scale (Salter, India) accurate to 100 g. BMI was calculated as weight in kilograms divided by square of height in meters.[25] We decided a cut-off value for BMI >27 kg/m2 to define obesity. Relevant biochemistry tests, urinalysis, and imaging studies (chest radiograph and ultrasound abdomen) were performed for all patients in a single laboratory accredited by national accreditation board for testing and calibration laboratories (NABL). Fully automated clinical chemistry analyzer (Olympus 2700) was used for biochemical analysis. Fasting and post-meal blood glucose was measured by hexokinase method, and cholesterol oxidase method was used for the estimation of lipid profile. Roshe E 601 analyzer was used for the assessment of serum insulin, basal and 1 hour post-meal C-peptide, thyroid profile, and microalbuminuria. Fasting serum samples were subjected to electrochemiluminiscence for insulin level determination. Basal and 1 hour post-meal C-peptide and thyroid profile were measured by chemiluminiscence method. Immunoturbidometry assay was utilized for detection of microalbuminuria in 24-hour urine specimen. Glycated hemoglobin (HbA1C) was checked with high-performance liquid chromatography (HPLC) method using Biorad variant D10. Patients with hypothyroidism were prescribed for thyroxine replacement. They were subjected to surgery after achievement of euthyroid state. Glomerular filtration rate was calculated using the modified Cockgroft–Gault equation.[26,27] Insulin resistance (IR) was assessed from the homeostasis model assessment (HOMA) formula (HOMA-IR) using fasting blood glucose and insulin.[28]

Outcomes

The primary outcome measures

Remission of T2DM, defined as HbA1c <6.5% without requiring oral or parenteral hypoglycemic agents.

Secondary outcome measures

Improvement in glycemic parameters [HbA1C, fasting blood sugar (FBS), post-lunch blood sugar (PLBS)]

Remission or improvement in hypertension

Improvement in other metabolic parameters like lipids, microalbuminuria, and uric acid

Improvement in weight and BMI in obese patients (BMI > 27 kg/m2)

Reduction in insulin and OHA requirement for glycemic control

As per the evaluation by previous studies[19,21] and American Diabetes Association (ADA) proposed criteria,[29] the outcomes were planned to be monitored and analyzed at 6 months interval.

Procedure

The operation was performed under general anesthesia with a standard six-port laparoscopic technique. The surgical procedure involved creation of a 170-cm segment of ileum, starting at 30 cm proximal to the ileo-cecal junction. This segment was interposed into jejunum, which was divided between 20 and 50 cm from the ligament of Treitz. All three anastomoses were performed side by side with an endo-GIA stapler (Ethicon Endo-surgery, Cincinnati, OH, USA) with a 45-mm white cartridge, and the stapler openings were closed by hand with a 3-03=0 polydioxanone suture in two layers. The mesenteric gaps were closed with non-absorbable 3-0 polypropylene sutures to prevent internal herniation. A variable sleeve gastrectomy was performed after devascularization of the greater curvature from the antrum to the fundus area. Figure 1 depicts diagrammatic representation of the procedure. The lumen of the stomach was adjusted by a 32–58 French calibrator (Romsons International, New Delhi, India) that was placed along the lesser curvature. The endo-GIA stapler with 60-mm cartridges was used for resection. Nonobese patients were subjected to only fundectomy, leaving a good volume of residual stomach for normal food intake.

Publication Date: 2014/09/02
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