A randomized controlled trial comparing oral and intravenous iron supplementation after Roux-en-Y gastric bypass surgery.

BACKGROUND: Iron deficiency (ID) is one of the most common postoperative deficiencies that may develop after Roux-en-Y gastric bypass (RYGB). The optimal mode of treatment is uncertain. AIM: To compare the efficacy of oral ferrous fumarate (FF), oral ferrous gluconate (FG), and a single intravenous infusion of ferric carboxymaltose (FCM) in women with ID after RYGB. METHODS: Multicenter randomized controlled trial including 120 women with a serum ferritin <20 µg/l during follow-up after RYGB. They were randomized into three groups: 41 patients were treated with FF 200 mg three times a day (total daily dose: 195 mg elemental iron), 39 received FG 695 mg twice a day (total daily dose: 160 mg elemental iron) for three months, and 39 patients were treated with a single intravenous dose of FCM (1000 mg elemental iron). Serum ferritin levels were measured at six weeks, and three, six and twelve months after the start of supplementation. RESULTS: At three months, persistence of ID was observed in 29.4% and 42.4% of the patients treated with FF and FG, respectively, but in none of those treated with FCM (p < 0.001). Over the next nine months, recurrence of ID was observed in 56.5% of patients treated with FF, in 52.9% treated with FG, and in 27.8% of those treated with FCM. Adverse effects were most common during oral treatment. CONCLUSION: In women developing ID after RYGB, a single dose of intravenous FCM is more effective and better tolerated than the standard treatment with either FF or FG. CLINICAL TRIAL REGISTRY NUMBER AND WEBSITE: The study was registered at clinicaltrials.gov under number NCT02271997.

RBP4 increases lipolysis in human adipocytes and is associated with increased lipolysis and hepatic insulin resistance in obese women.

Retinol-binding protein-4 (RBP4) is elevated in serum and adipose tissue (AT) in obesity-induced insulin resistance and correlates inversely with insulin-stimulated glucose disposal. But its role in insulin-mediated suppression of lipolysis, free fatty acids (FFA), and endogenous glucose production (EGP) in humans is unknown. RBP4 mRNA or protein levels were higher in liver, subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) in morbidly obese subjects undergoing Roux-en-Y gastric bypass surgery compared to lean controls undergoing elective laparoscopic cholecystectomy. RBP4 mRNA expression in SAT correlated with the expression of several macrophage and other inflammation markers. Serum RBP4 levels correlated inversely with glucose disposal and insulin-mediated suppression of lipolysis, FFA, and EGP. Mechanistically, RBP4 treatment of human adipocytes in vitro directly stimulated basal lipolysis. Treatment of adipocytes with conditioned media from RBP4-activated macrophages markedly increased basal lipolysis and impaired insulin-mediated lipolysis suppression. RBP4 treatment of macrophages increased TNFα production. These data suggest that elevated serum or adipose tissue RBP4 levels in morbidly obese subjects may cause hepatic and systemic insulin resistance by stimulating basal lipolysis and by activating macrophages in adipose tissue, resulting in release of pro-inflammatory cytokines that impair lipolysis suppression. While we have demonstrated this mechanism in human adipocytes in vitro, and correlations from our flux studies in humans strongly support this, further studies are needed to determine whether this mechanism explains RBP4-induced insulin resistance in humans.

The True Story on Deficiencies After Sleeve Gastrectomy: Results of a Double-Blind RCT.

BACKGROUND: Since a few years, the laparoscopic sleeve gastrectomy (SG) has become the most performed bariatric operation worldwide. However, as with all bariatric procedures, SG also leads to vitamin and mineral deficiencies post-operatively and standard multivitamin supplements are probably not sufficient. OBJECTIVE: The present study evaluates the effectiveness of a specialized multivitamin supplement for SG patients (WLS Optimum 1.0, FitForMe, Rotterdam, the Netherlands), compared to a standard multivitamin supplement (sMVS). DESIGN: A double-blind randomized controlled trial was performed. For 12 months, patients in the intervention group received WLS Optimum, containing elevated doses of multiple vitamins and minerals. Patients in the control group were provided with sMVS, containing 100% of the recommended dietary allowance. RESULTS: In total, 139 patients were available for analysis (WLS Optimum, n = 69; sMVS, n = 70). Intention-to-treat analyses revealed more folic acid deficiencies and higher serum vitamin B1 levels in the WLS Optimum group. Per protocol analyses showed that in patients using WLS Optimum, serum folic acid and vitamin B1 levels were higher, serum PTH levels were lower, and only one patient (2.6%) was anemic compared to 11 patients (17.5%) using a sMVS (p < 0.05 for all). No differences were found in prevalence of deficiencies for iron, vitamin B12, vitamin D, and other vitamins and minerals. CONCLUSIONS: This optimized multivitamin supplement only affected serum levels of folic acid, PTH and vitamin B1, and anemia rates compared to a sMVS. There is a clear need to further optimize multivitamin supplementation for SG patients. Besides, non-compliance with multivitamin supplements remains an important issue that should be dealt with. CLINICAL TRIAL REGISTRY: The study protocol was registered at the clinical trials registry of the National Institutes of Health (ClinicalTrials.gov; identifier NCT01609387).

A novel abdominal wall entry suction device to increase Veress needle safety: A prospective cohort pilot study.

BACKGROUND: In laparoscopic surgery, the Veress needle technique is most often used to initiate a pneumoperitoneum. Although low, entry-related injuries of the intestines and major vascular structures occur in 0.04-0.1% of cases. Up to 50% of these injuries remain undiagnosed at the time of surgery, resulting in mortality rates between 2.5 and 30%. In an effort to minimize such injuries we objectively assessed a novel abdominal wall entry suction device (AWESD) that was hypothesized to lift the abdominal wall and create an additional post-peritoneum safe margin for safer Veress needle introduction. MATERIALS AND METHODS: A prospective pilot study was conducted in which CT-scans with and without AWESD application (centered above the umbilicus) were assessed to determine its effect on the distance from the linea alba to the intestines, vena cava and abdominal aorta. Paired measurements were subjected to the Wilcoxon signed rank test. RESULTS: Twelve participants were included. The AWESD significantly increased the median distance towards the intestines in the axial and sagittal plane (P = 0.01 and P = 0.006) from 0.93 (Inter Quartile Range (IQR): 0.33-1.51) and 0.85 (IQR: 0.32-1.47) to 1.35 (IQR: 0.39-2.27) and 1.25 (IQR: 0.42-2.10) centimeters, respectively. Similarly, for the median axial distances towards the vena cava and abdominal aorta (both P = 0.002) that were increased from 10.00 (IQR: 7.18-11.12) and 9.33 (IQR: 6.55-10.28) to 13.23 (IQR: 11.76-14.31) and 12.49 (IQR: 10.98-13.32) centimeters, respectively. CONCLUSION: The AWESD significantly increased the distances between the peritoneum and main intra-abdominal structures. However, conclusions on subsequent increased safety cannot be drawn as high-volume studies are required to determine its clinical relevance.

Genetic analysis in the bariatric clinic; impact of a PTEN gene mutation.

BACKGROUND: Pathogenic PTEN gene mutations are known to cause PTEN tumor hamartoma syndrome. Recent studies also suggest a role for PTEN mutations in the pathogenesis of obesity. No PTEN mutations have been reported among bariatric surgery patients and obesity treatment results are unknown. Since preventive screening for associated tumors is offered to patients with molecular proven PTEN hamartoma tumor syndrome, recognition of this condition in the bariatric surgery clinic is important. METHOD: We present a patient with morbid obesity who carries a known pathogenic PTEN mutation, identified at the bariatric surgery clinic using an obesity gene panel consisting of 52 obesity-associated genes. We analyzed the weight loss response during the first 3 years after Sleeve Gastrectomy. RESULTS: At 1, 2 and 3 years after surgery, the patient achieved a Total Body Weight Loss of 39.4%, 48.8% and 44.9%, respectively. This corresponds to the results of a control group of 18 female patients with normal genetic test results. CONCLUSION: Our patient illustrates the importance of recognizing this serious genetic condition for which preventive cancer screening options are available. The positive weight loss results after Sleeve Gastrectomy suggest that this could be a successful treatment option for obesity patients with PTEN mutations.

Correction to: Adequate Multivitamin Supplementation after Roux-En-Y Gastric Bypass Results in a Decrease of National Health Care Costs: a Cost-Effectiveness Analysis.

In the original article, there are some incorrect data in the "Results" section of the Abstract.

Adequate Multivitamin Supplementation after Roux-En-Y Gastric Bypass Results in a Decrease of National Health Care Costs: a Cost-Effectiveness Analysis.

INTRODUCTION: Patients with morbid obesity undergoing metabolic surgery are prone to develop vitamin and mineral deficiencies, which may worsen in time. In order to prevent these deficiencies after metabolic surgery, all patients are advised to take daily multivitamin supplementation. The aim of the study was to assess the cost-effectiveness of specially developed multivitamins (WLS Forte®) for metabolic surgery and over-the-counter (standard) multivitamin supplementation (sMVS). METHODS: This cost-effectiveness analysis was preformed alongside an RCT for the Netherlands. Between June 2011 and March 2012, a total of 148 patients were randomized to one tablet daily of either WLS Forte® or sMVS. The patients were followed for 12 months. Data on costs within the health sector and outside the health sector were collected. The primary outcome is financial and logistic advantages, in terms of less patient visits to the outpatient department and the relevant costs to the employer due to absenteeism. RESULTS: In total, 10 (14%) patients in the WLS Forte® group versus 23 (30%) patients in the sMVS group developed a deficiency. The costs for the WLS forte® supplement were €38 versus €23 for sMVS. Additional return visits and associated costs for medical staff were the largest costs, up to 43% in the sMVS group. Total costs for supplementation with sMVS were €243 versus €134 for WLS Forte®. CONCLUSION: Preventing deficiencies with WLS Forte® seem initially more expensive than sMVS. However, treatment with WLS Forte® resulted in less vitamin and mineral deficiencies, which eventually resulted in less overall costs.

Failed Sleeve Gastrectomy: Single Anastomosis Duodenoileal Bypass or Roux-en-Y Gastric Bypass? A Multicenter Cohort Study.

BACKGROUND: Sleeve gastrectomy (SG) has become the most performed bariatric procedure to induce weight loss worldwide. Unfortunately, a significant portion of patients show insufficient weight loss or weight regain after a few years. OBJECTIVE: To investigate the effectiveness of the single anastomosis duodenoileal (SADI) bypass versus the Roux-en-Y gastric bypass (RYGB) on health outcomes in morbid obese patients who had undergone SG previously, with up to 2 years of follow-up. METHODS: From 2007 to 2017, 140 patients received revisional laparoscopic surgery after SG in four specialized Dutch bariatric hospitals. Data was analyzed retrospectively and included comparisons for indication of surgery, vitamin/mineral deficiencies, and complications; divided into short-, medium-term. To compare weight loss, linear regression and linear mixed models were used. RESULTS: Conversion of a SG to SADI was performed in 66 patients and to RYGB in 74 patients. For patients in which additional weight loss was the main indication for surgery, SADI achieved 8.7%, 12.4%, and 19.4% more total body weight loss at 6, 12, and 24 months compared to RYGB (all p < .001). When a RYGB was indicated in case of gastroesophageal reflux or dysphagia, it greatly reduced complaints almost directly after surgery. Furthermore, a similar amount of complications and nutritional deficiencies was observed for both groups. There was no intra- or post-operative mortality. CONCLUSION: Conversion into a SADI resulted in significantly more weight loss while complications rates and nutritional deficiencies were similar and may therefore be considered the recommended operation for patients in which only additional weight loss is required.

Efficacy of oral compared with intramuscular vitamin B-12 supplementation after Roux-en-Y gastric bypass: a randomized controlled trial.

Background: After Roux-en-Y gastric bypass (RYGB), patients often develop a vitamin B-12 deficiency. Objective: Our objective was to investigate whether oral supplementation increases and normalizes low vitamin B-12 concentrations (vitamin B-12 > 200 pmol/L) in RYGB patients as compared to intramuscular injections. Design: A randomized controlled trial in RYGB patients with subnormal serum B-12 concentrations was performed. One group (IM B-12) received bimonthly intramuscular hydroxocobalamin injections (2000 µg as loading dose and 1000 µg at follow-up) for 6 mo. The second group (oral B-12) received daily doses of oral methylcobalamin (1000 µg). Serum vitamin B-12 was determined at baseline (T0) and at 2 (T1), 4 (T2), and 6 mo (T3) after start of treatment. Concentrations of the secondary markers methylmalonic acid (MMA) and homocysteine (Hcy) were measured at T0 and T3. Results: Fifty patients were included and randomized, 27 in IM B-12 and 23 in oral B-12. The median vitamin B-12 concentration at T0 was 175 pmol/L (range: 114-196 pmol/L) for IM B-12 and 167 pmol/L (range: 129-199 pmol/L) for oral B-12. Vitamin B-12 normalized in all individuals, and there was no significant difference in vitamin B-12 between the two groups. MMA and Hcy concentrations decreased significantly after 6 mo within each group (P < 0.001 and P < 0.001 for MMA and P = 0.03 and P = 0.045 for Hcy, respectively). There was no significant difference between the groups at 6 mo for both MMA and Hcy (P = 0.53 and P = 0.79). Conclusion: The efficacy of oral vitamin B-12 supplementation was similar to that of hydroxocobalamin injections in the present study. Oral supplementation can be used as an alternative to hydroxocobalamin injections to treat RYGB patients with low values of serum vitamin B-12. This trial was registered at clinicaltrials.gov as NCT02270749.

Do specialized bariatric multivitamins lower deficiencies after RYGB?

BACKGROUND: One of the side effects of bariatric surgery is the risk of vitamin and mineral deficiencies. Vitamin B12, vitamin D, folate, and iron deficiencies are especially common among Roux-en-Y gastric bypass patients. OBJECTIVE: To examine the effectiveness of a specialized multivitamin supplement for Roux-en-Y gastric bypass patients on deficiencies the first 3 years postoperatively, retrospectively in a large, prospectively collected cohort. SETTING: Large specialized bariatric hospital. RESULTS: One thousand one hundred sixty patients were included, 883 users and 258 who were nonusers of the specialized multivitamin. Patient characteristics and total weight were comparable. Higher serum concentrations of ferritin (124.7 ± 96.2 µg/L versus 106.0 ± 83.0 µg/L, P = .016), vitamin B12 (347.3 ± 145.1 pmol/L versus 276.8 ± 131.4 pmol/L, P<.001), folic acid (34.9 ± 9.6 nmol/L versus 25.4 ± 10.7 nmol/L, P<.001), and vitamin D (98.4 ± 28.7 nmol/L versus 90.0 ± 34.5 nmol/L, P = .002) were observed in users compared with nonusers after 1 year. Less new deficiencies were found for ferritin (1% versus 4%, P = .029), vitamin B12 (9% versus 23%, P<.001), and vitamin D (0% versus 4%, P<.001) in users compared with nonusers. Two and 3 years after the surgery these findings remained almost identical. CONCLUSIONS: The use of specialized multivitamin supplements resulted in less deficiencies of vitamin B12, vitamin D, folic acid, and ferritin. The study showed that Roux-en-Y gastric bypass patients benefited from the specialized multivitamin supplements and it should be advised to this patient group.

Diagnosing Internal Herniation After Roux-en-Y Gastric Bypass Surgery: Literature Overview, Cadaver Study and the Added Value of 3D CT Angiography.

PURPOSE: The purposes of the study are to outline the complexity of diagnosing internal herniation after Roux-en-Y gastric bypass (RYGB) surgery and to investigate the added value of computed tomography angiography (CTA) for diagnosing internal herniation. MATERIALS AND METHODS: A cadaver study was performed to investigate the manifestations of internal hernias and mesenteric vascularization. Furthermore, a prospective, ethics approved study with retrospective interpretation was conducted. Ten patients, clinically suspected for internal herniation, were prospectively included. After informed consent was obtained, these subjects underwent abdominal CT examination, including additional arterial phase CTA. All subjects underwent diagnostic laparoscopy for suspected internal herniation. The CTA was used to create a 3D reconstruction of the mesenteric arteries and surgical staples (3D CTA). The 3D CTA was interpreted, taking into account the presence and type of internal hernia that was found upon laparoscopy. RESULTS: Cadaveric analysis demonstrated the complexity of internal herniation. It also confirmed the expected changes in vascular structure and surgical staple arrangement in the presence of internal herniation. 3D CTA studies of the subjects with active internal hernias demonstrated remarkable differences when compared to control 3D CTA studies. The blood supply of herniated intestinal limbs in particular showed abnormal trajectories. Additionally, enteroenterostomy staple lines had migrated or altered orientation. CONCLUSION: 3D CTA is a promising technique for diagnosing active internal hernias. Our findings suggest that for diagnosing internal hernias, focus should probably shift from routine abdominal CT examination towards the 3D assessment of the mesenteric vasculature and surgical staples.

Changes in Iron Absorption After Roux-en-Y Gastric Bypass.

INTRODUCTION: Iron deficiency is one of the most common deficiencies that may occur after Roux-en-Y gastric bypass (RYGB). Little is known about the optimal treatment of post-RYGB iron deficiency. AIM: The aim of this study is to evaluate the changes in iron absorption characteristics after RYGB for two oral iron formulations, one presented in tablet form and one as in the form of a solution. METHOD: Iron absorption in 24 obese women was studied before and 1 month after RYGB. Twelve patients were tested with a single dose of 600 mg ferrous fumarate in tablet form (195 mg of elementary iron, group 1), and 12 patients received a single dose of 1390 mg ferrous gluconate as a solution (160 mg of elementary iron, group 2). Serum iron levels were measured before (T0) and every hour after ingestion of the supplement (T1-T9). RESULTS: Before surgery, iron absorption was similar for the two supplements (P = 0.71). However, RYGB was associated with a decrease in fumarate iron absorption (P < 0.001) but did not affect gluconate iron absorption (P = 0.13). Postoperative absorption of fumarate iron was significantly lower than gluconate iron at T1 (P < 0.05), but the overall difference over 9 h did not reach statistical significance (P = 0.53). CONCLUSION: RYGB adversely affects the absorption of ferrous fumarate tablets but not that of solubilized ferrous gluconate. A solubilized supplement is therefore preferred as the supplement of first choice after RYGB.

Long-term nutritional status in patients following Roux-en-Y gastric bypass surgery.

BACKGROUND & AIMS: Roux-en-Y gastric bypass (RYGB) is an effective treatment for obesity. However, it also leads to multiple nutritional deficiencies. Much is known about the short term prevalence, but hardly any long term data is available on deficiencies. The aim of this study was to assess the long term outcome of nutritional status after RYGB. METHODS: We performed a retrospective analysis of prospectively collected data obtained from 51 morbidly obese patients who underwent a primary laparoscopic RYGB. Primary outcomes were iron, vitamin B12 and vitamin D deficiencies. Secondary outcomes were deficiencies of other vitamins and minerals and compliance of the patients to multivitamin use. RESULTS: The mean follow-up was 81 ± 27 months. A total of 35%, 16% and 55% of the patients had deficiencies for iron, vitamin B12 and vitamin D respectively. Sixty-nine percent of patients used a (nonspecific) multivitamin supplement on a daily basis. Patients with multivitamin usage had a lower rate of iron deficiency (26% vs. 56%, p = 0.034), vitamin B12 (11% vs. 25%, p = 0.46) and vitamin D (46% vs. 75%, p = 0.07), compared to non-compliant patients. CONCLUSIONS: Nutritional deficiencies are common after a RYGB operation. Therefore, strict follow-up by a bariatric surgeon, endocrinologist or general practitioner is required, both short and long term.

Treatment of Vitamin and Mineral Deficiencies After Biliopancreatic Diversion With or Without Duodenal Switch: a Major Challenge.

BACKGROUND: Vitamin and mineral deficiencies are a major concern after biliopancreatic diversion (BPD) and BPD with duodenal switch (BPD/DS). Evidence-based guidelines how to prevent or how to treat deficiencies in these patients are currently lacking. The aim of the current study is to give an overview of postsurgical deficiencies and how to prevent and treat these deficiencies. METHODS: Retrospective evaluation of a 1-year structured monitoring and treatment schedule for various deficiencies in 34 patients after BPD or BPD/DS. RESULTS: Patients were introduced into the program 12-90 months after surgery. Vitamin B1, B6, B9, and B12 deficiencies could be prevented by mean daily doses of 2.75 mg, 980 µg, 600 µg, and 350 µg, respectively. However, many patients continued to develop deficiencies of vitamin A, D, iron, calcium, and zinc despite major dose adjustments. Current observations suggest that at least total daily doses of 200 mg Fe in premenopausal women and 100 mg in men, 100 mg of Zinc, 3000 mg of calcium, and weekly doses of at least 50,000 IU solubilized vitamin A and vitamin D are needed to prevent the occurrence of major deficiencies. CONCLUSION: Exceptionally high supplementation doses are needed to prevent and treat vitamin and mineral deficiencies in patients after BPD or BPD/DS. Further refinement and simplification of treatment schedules is needed. Focus on improvement of compliance to treatment is recommended.

Inflammatory Bowel Disease Is Not a Contraindication for Bariatric Surgery.

BACKGROUND: Inflammatory bowel diseases (IBD) are listed as a contraindication for bariatric surgery in various guidelines due to a theoretical higher complication risk. Therefore, little is known about safety and efficacy of bariatric surgery in IBD patients. AIM: We assessed the safety and efficacy of bariatric surgery and postoperative quality of life (QoL) in IBD patients. SETTING: The study was conducted in a large peripheral hospital in the Netherlands. METHODS: All IBD patients who underwent bariatric surgery in our facility were included. Complications, mortality, reoperations, and micronutrient deficiencies were analyzed. Weight loss was assessed 6, 12, and 24 months after surgery. Postoperative QoL was assessed using a disease-specific Inflammatory Bowel Disease Questionnaire (IBDQ). RESULTS: Forty-five patients were included in this study, all diagnosed with IBD (16 ulcerative colitis (UC) and 29 Crohn's disease (CD)) prior to bariatric surgery. Bariatric procedures included Roux-en-Y gastric bypass, sleeve gastrectomy, gastric banding, and revisional surgery. There was no mortality in the entire follow-up period and there were no major perioperative complications. Two major complications in two CD patients occurred during follow-up, gastro-enterostomy bleeding and pyelonephritis with secondary pancreatitis. Mean percentage (± SD) of overall excess weight loss (%EWL) and total body weight loss (%TBWL), 12 months after surgery, were 62.9 ± 27.1 and 26.2 ± 10.6%, respectively. Twenty-four months postoperatively, mean overall %EWL and %TBWL were similar for both UC and CD patients and were 62.9 ± 31.0 and 26.6 ± 12.2, respectively. Mean Bariatric Analysis and Reporting Outcome System (BAROS) score was 3.34 ± 2.42. Median total IBDQ score was 170.8 (min. 77; max. 218). Both scores did not differ significantly between UC and CD patients. CONCLUSION: As bariatric procedures appear safe and effective in this CU and CD population, one could question why bariatric surgery is contraindicated in the patients. Nevertheless, close lifelong monitoring to assure safety and a favorable outcome remains essential.

The Effect of 6 and 12 months Duodenal-Jejunal Bypass Liner Treatment on Obesity and Type 2 Diabetes: a Crossover Cohort Study.

OBJECTIVE: The aim of this research was to study the duodenal-jejunal bypass liner (DJBL) treatment for obesity and type 2 diabetes mellitus (T2DM) in patients after dietary treatment in a cross-over design. BACKGROUND: DJBL treatment has been proven effective for treatment of obesity and T2DM. However, data on safety and efficacy of a 12-month DJBL treatment is limited. METHODS: In 2014, our research group reported on a multicenter randomized clinical trial. Patients were randomized to DJBL or dietary treatment (control group). Twenty-eight patients crossed over after their dietary treatment and received up to 12 months of DJBL treatment. Patient visits were conducted at baseline, during DJBL treatment (1 week, 1-6, 9, 12 months) and 6 months after removal of the liner. Patients underwent a standard physical examination, blood sampling, assessment of adverse events, nutritional and diabetes counseling, and a standardized meal tolerance test. RESULTS: Of the 28 patients included in this study, 24 patients completed 6 months of treatment. Eighteen patients were extended to 12 months of DJBL treatment; 13 patients completed this treatment period. After 6 months of DJBL treatment, a significant increase in excess weight loss (EWL) and decrease in weight, BMI, HbA1c, fasting glucose, cholesterol, HDL and LDL improved significantly. After 12 months of DJBL treatment, these parameters stabilized. CONCLUSIONS: The DJBL is an effective, minimally invasive treatment option. Even after successful treatment with dietary restrictions, the DJBL is still capable of significantly reducing weight and improving cardiovascular and type 2 diabetes mellitus parameters in obese patients.

Risk of Metformin-Associated Lactic Acidosis (MALA) in Patients After Gastric Bypass Surgery.

BACKGROUND: Pharmacokinetic data suggest that the risk of metformin-associated lactic acidosis (MALA) may be increased after Roux-en-Y gastric bypass (RYGB) surgery. The aim of this study was to examine the impact of metformin on plasma lactate levels before and after RYGB surgery. METHODS: Retrospective study of plasma lactate levels before and 3 months after RYGB surgery in patients with type 2 diabetes mellitus (T2DM) not using metformin (MET-0, N = 58), on a stable dose (MET-S, N = 138), or on a decreasing dose (MET-D, N = 85) of metformin. RESULTS: Preoperatively, lactate levels were similar in patients on metformin (1.8 ± 0.05 mmol/L) and those not on metformin (1.7 ± 0.08 mmol/L), P = 0.21. Three months postoperatively, lactate levels had decreased in all groups (P < 0.001) to 1.3 ± 0.07 (SE), 1.4 ± 0.05, and 1.2 ± 0.05 mmol/l in MET-0, MET-S, and MET-D, respectively. Lactate levels differed between the groups (P = 0.03), with the lowest level in MET-D. The number of patients with hyperlactatemia (lactate > 2 mmol/l) decreased from 31 to 14%, from 22 to 8.6%, and from 26 to 4.7% in MET-S, MET-0, and MET-D, respectively. CONCLUSION: Mild hyperlactatemia (lactate > 2 mmol/l) is common in morbidly obese patients with T2DM. It is probably related to increase lactate production by adipocytes. Lactate levels decreased after RYGB-induced weight loss, irrespective of the use of metformin. We therefore conclude that there is no need for routinely lowering of the metformin dose after uncomplicated RYGB surgery, as long as normal renal function is preserved.

Gastric pouch emptying of solid food in patients with successful and unsuccessful weight loss after Roux-en-Y gastric bypass surgery.

BACKGROUND: After Roux-en-Y gastric bypass (RYGB), approximately 10% of patients have insufficient weight loss (excess body mass index loss<50%). Gastric pouch emptying may have a role in weight loss. OBJECTIVES: To compare pouch emptying of patients with poor weight loss and patients with successful weight loss after RYGB. SETTING: A research-intensive nonacademic hospital and center of expertise in bariatric surgery in the Netherlands METHODS: Female patients were included from among patients with the least (poor weight loss group [P-WL]) and the most weight loss (successful weight loss group [S-WL]) in our center 2 years after RYGB. Pouch emptying scintigraphy was performed after ingestion of a radiolabeled solid meal. Emptying curves, intestinal content (IC) at meal completion and after 15, 30, 45, and 60 minutes, half emptying time, and maximal pouch emptying rate were compared. RESULTS: Five individuals were included in P-WL and 5 in S-WL, on average 2.5 ± .3 years after RYGB. Total weight loss was 18 ± 4.1% in P-WL and 44 ± 5.7% in S-WL (P<.001). In P-WL, a fast initial pouch emptying and exponential emptying curve was observed, compared with a slower initial emptying and more linear curve in S-WL. Faster emptying in P-WL was also shown by a larger ICmeal (42 ± 18% versus 4.0 ± 3.3%,), IC15 (76 ± 15% versus 35 ± 22%), and IC30 (85 ± 12% versus 54 ± 25%), and a greater maximal pouch emptying rate (17 ± 4.7 versus 5.6 ± 3.4%/min) compared with S-WL (P<.05). A linear correlation was found between total weight loss and maximal pouch emptying rate (Pearson R = .82, P = .004). CONCLUSIONS: Pouch emptying for solid food was faster in patients with the least weight loss compared with patients with the most weight loss after RYGB. If pouch emptying is an important mechanism in weight loss, altering the pouch outlet may improve poor weight loss management.

Patients' Preoperative Estimate of Target Weight and Actual Outcome after Bariatric Surgery.

BACKGROUND: Evidence about the impact of psychological factors on weight loss after bariatric surgery is scarce. This study explores whether patients' preoperative estimate of target weight influences actual weight loss for different types of bariatric procedures. METHODS: Patients eligible for bariatric surgery were instructed twice on how to calculate their expected target weight. They were divided into three groups based on their percentage excess weight loss (%EWL) and percentage total body weight loss (%TBWL). Weight loss 12 and 24 months after surgery was analyzed for each group and per type of surgery. RESULTS: Six hundred fifty-six patients participated in this study. Types of surgery performed were the Roux-en-Y gastric bypass (RYGB, 75%), sleeve gastrectomy (SG, 8.1%), REDO-RYGB (12.5%), and laparoscopic adjustable gastric banding (LAGB, 4.4%). Data of 622 and 410 patients were available for analysis at 12 and 24 months, respectively. Surprisingly, 415 patients (63.3%) overestimated their expected weight loss as opposed to our calculation, based on our own historic data. One hundred thirty-four patients (20.4%) estimated their weight loss correctly and 107 patients (16.3%) underestimated their weight loss. There was a significant higher %EWL 12 months after RYGB surgery for patients who overestimated their weight loss compared to those who estimated their weight loss correctly (p = 0.001). After 24 months and for other types of procedures, no statistically significant differences were found between the three groups. CONCLUSION: Despite instructions on how to calculate target weight, the majority of patients overestimated their weight loss. Actual %EWL 12 months after RYGB surgery might be influenced by setting a low target weight.

A short or a long Roux limb in gastric bypass surgery: does it matter?

BACKGROUND: The Roux-en-Y gastric bypass (RYGB) still remains the gold standard in bariatric surgery. However, no consensus exists on the optimal limb lengths to induce maximum weight reduction. The aim of the present study was to assess the effect of a longer alimentary limb (AL) length on weight reduction after RYGB. METHODS: A retrospective analysis of a prospectively collected database of patients who underwent a primary laparoscopic RYGB between January 2001 and March 2011 was performed. Patients received a short AL (SAL; 100 cm) or a long AL (LAL; 150 cm). Primary outcome was weight loss, and secondary outcomes were short- and long-term complication rates. RESULTS: A total of 768 patients received a RYGB during the study period. Of these, 730 consecutive patients were included for long-term analysis and had a mean follow-up (FU) of 37 ± 26 [range 0-120] months; 360 (47 %) patients received a SAL RYGB. Overall %TBWL was 33 ± 9 % after 2 years (FU 74 %) and 28 ± 12 % after 5 years (FU 20 %). No significant differences in %TBWL were found between SAL RYGB and LAL RYGB during the study period. The 30-day mortality rate was 0.13, 9 % overall short-term complication rate and 19 % cumulative long-term complication rate. No differences in complications were found between SAL and LAL RYGB patients. CONCLUSION: Lengthening of the alimentary limb from 100 to 150 cm did not affect post-RYGB weight loss. Overall complication rates were low and comparable in this series of RYGB patients.