Differences in Psychological Health and Weight Loss after Bariatric Metabolic Surgery between Patients with and without Pain Syndromes.

PURPOSE: Chronic pain and obesity often co-occur, negatively affecting one another and psychological wellbeing. Pain and psychological wellbeing improve after bariatric metabolic surgery (BMS), however, it is unknown whether psychological wellbeing improves differently after weight loss between patients with and without chronic pain. We investigated whether weight loss is associated with greater psychological wellbeing and functioning change after BMS, comparing patients with and without preoperative pain syndromes. METHODS: Depression, health-related quality of life, self-esteem, self-efficacy to exercise and controlling eating behaviours, physical activity, and food cravings were measured before and 24 months after BMS among 276 patients with obesity. The presence of preoperative chronic pain syndromes was examined as a moderator for the relationship between 24-month weight loss and changes in psychological outcomes. RESULTS: Chronic pain syndromes were present among 46% of patients. Weight loss was associated with greater improvement in health-related quality of life, self-efficacy to exercise and controlling eating behaviours, self-esteem and greater amelioration in food cravings. Pain syndromes only moderated negatively the relationship between the postoperative weight loss and change in self-efficacy to control eating behaviours (b = -0.49, CI [-0.88,-0.12]). CONCLUSION: Patients with and without chronic pain showed similar improvements in weight and psychological wellbeing and behaviours after BMS. The relationship between weight loss and the improvement of self-efficacy to control eating behaviours was weaker among patients with chronic pain syndrome. Further work, measuring pain severity over time, is needed to shed light on the mechanism underlying pain and postoperative change in psychological wellbeing and weight loss.

A Prospective Study on the Diagnoses for Abdominal Pain After Bariatric Surgery: The OPERATE Study.

PURPOSE: Long-term follow-up after bariatric surgery (BS) reveals high numbers of patients with abdominal pain that often remains unexplained. The aim of this prospective study was to give an overview of diagnoses for abdominal pain, percentage of unexplained complaints, number and yield of follow-up visits, and time to establish a diagnosis. MATERIALS AND METHODS: Patients who visited the Spaarne Gasthuis Hospital, The Netherlands, between December 2020 and December 2021 for abdominal pain after BS, were eligible and followed throughout the entire episode of abdominal pain. Distinction was made between presumed and definitive diagnoses. RESULTS: The study comprised 441 patients with abdominal pain; 401 (90.9%) females, 380 (87.7%) had Roux-en-Y gastric bypass, mean (SD) % total weight loss was 31.4 (10.5), and median (IQR) time after BS was 37.0 (11.0-66.0) months. Most patients had 1-5 follow-up visits. Readmissions and reoperations were present in 212 (48.1%) and 164 (37.2%) patients. At the end of the episode, 88 (20.0%) patients had a presumed diagnosis, 183 (41.5%) a definitive diagnosis, and 170 (38.5%) unexplained complaints. Most common definitive diagnoses were cholelithiasis, ulcers, internal herniations, and presumed diagnoses irritable bowel syndrome (IBS), anterior cutaneous nerve entrapment syndrome, and constipation. Median (IQR) time to presumed diagnoses, definitive diagnoses, or unexplained complaints was 16.0 (3.8-44.5), 2.0 (0.0-31.5), and 13.5 (1.0-53.8) days (p < 0.001). Patients with IBS more often had unexplained complaints (OR 95%CI: 4.457 [1.455-13.654], p = 0.009). At the end, 71 patients (16.1%) still experienced abdominal pain. CONCLUSION: Over a third of abdominal complaints after BS remains unexplained. Most common diagnoses were cholelithiasis, ulcers, and internal herniations.

Attachment style and post-bariatric surgery health behaviours: the mediating role of self-esteem and health self-efficacy.

BACKGROUND: Attachment avoidance and anxiety have been linked to overweight and poor health behaviours, yet the mechanisms that underpin the relationship between attachment and health behaviours are not fully understood. Self-esteem and self-efficacy have been found to differ between attachment styles, rendering these variables potential mediators of the relationship. This longitudinal study investigated the serial mediation between preoperative attachment and 2-year post-operative health behaviours through self-esteem and health self-efficacy. METHODS: Participants were 263 bariatric surgery patients (75.7% females, aged 47.7 ± 10.4 years, BMI 38.9 ± 3.6 kg/m2) assessed before the operation and again one and two years after the surgery. Patients completed the Experiences for Close Relationships Brief Scale, Rosenberg Self-esteem scale, Weight Efficacy Lifestyle Questionnaire, Bariatric Surgery Self-Management Questionnaire, Exercise Self-Efficacy Scale and the Exercise Behaviour Scale. RESULTS: Higher preoperative attachment anxiety and avoidance were associated with lower self-esteem one year after bariatric surgery and poorer health self-efficacy two years after the surgery. Self-esteem and health self-efficacy mediated the relationships between preoperative anxious and avoidant attachment and 2- year post-operative diet adherence and physical activity. CONCLUSIONS: Helping patients to feel more worthy and reinforcing their beliefs about their own competences could lead to higher engagement with healthy lifestyle and adherence to treatment protocols, ultimately helping patients to achieve their goals for bariatric surgery. CLINICAL TRIAL REGISTRATION: BARIA: Netherlands Trial Register: NL5837 (NTR5992) https://www.trialregister.nl/trial/5837 . Diabaria: ClinicalTrials.gov identifier (NCT number): NCT03330756.

Is Adherence to Follow-Up After Bariatric Surgery Necessary? A Systematic Review and Meta-Analysis.

The association of adherence to follow-up (FU) after laparoscopic gastric bypass - and gastric sleeve with weight loss (WL) is unclear. The aim of this study was to evaluate this association. Fourteen full text articles were included in the systematic review. Eight studies were included in the meta-analysis concerning FU up to 3 years postoperatively and 3 for the FU between 3 and 10 years postoperatively. Results showed a significant association between adherence to FU 0.5 to 3 years postoperatively and percentage excess WL (%EWL) but did not demonstrate a significant association between FU > 3 years postoperatively and total WL (%TWL). In conclusion, adherence to FU may not be associated with WL and therefore stringent lifelong FU in its current form should be evaluated.

Weight Loss Results and Compliance with Follow-up after Bariatric Surgery.

PURPOSE: The importance of follow-up (FU) for midterm weight loss (WL) after bariatric surgery is controversial. Compliance to this FU remains challenging. Several risk factors for loss to FU (LtFU) have been mentioned. The aim was therefore to evaluate the association between WL and LtFU 3 to 5 years postoperatively and to identify risk factors for LtFU. MATERIALS AND METHODS: A single-center cross-sectional study in the Netherlands. Between June and October 2018, patients scheduled for a 3-, 4-, or 5-year FU appointment were included into two groups: compliant (to their scheduled appointment and overall maximally 1 missed appointment) and non-compliant (missed the scheduled appointment and at least 1 overall). Baseline, surgical, and FU characteristics were collected and a questionnaire concerning socio-economic factors. RESULTS: In total, 217 patients in the compliant group and 181 in the non-compliant group were included with a median body mass index at baseline of 42.0 and 42.9 respectively. Eighty-eight percent underwent a laparoscopic Roux-en-Y gastric bypass. The median percentage total weight loss for the compliant and non-compliant groups was 30.7% versus 28.9% at 3, 29.3% versus 30.2% at 4, and 29.6% versus 29.9% at 5 years respectively, all p>0.05. Age, persistent comorbidities and vitamin deficiencies, a yearly salary <20,000 euro, no health insurance coverage, and not understanding the importance of FU were risk factors for LtFU. CONCLUSION: Three to 5 years postoperatively, there is no association between LtFU and WL. The compliant group demonstrated more comorbidities and vitamin deficiencies. Younger age, not understanding the importance of FU, and financial challenges were risk factors for LtFU.

Smoking Behaviour and Beliefs About Smoking Cessation After Bariatric Surgery.

PURPOSE: Currently, bariatric surgery is the most effective intervention for treating morbid obesity and its complications. Smoking cessation is likely to improve smoking-related comorbidities and decrease postoperative complications. This study evaluated the smoking behaviour and thoughts about smoking cessation of patients more than 18 months after bariatric surgery. MATERIALS AND METHODS: A cross-sectional study was performed in patients who underwent bariatric surgery from July 2012 to December 2013. A questionnaire was used to evaluate smoking status, thoughts about the health benefits of cessation and characteristics of previous quit attempts in current and former smokers. Finally, actual bariatric surgery outcomes were evaluated in current, former and never smokers. RESULTS: Six hundred nine patients (response rate 52.0%) were included. Of them, 101 (16.6%) patients were current smokers, 239 (39.2%) former smokers and 269 (44.2%) patients were lifetime never smokers. Compared with former smokers, current smokers were less aware of the beneficial effects of smoking cessation on their general health; 66.4% of the former smokers thought smoking cessation would be much better for general health, compared with 20.6% of current smokers. Total weight loss was 2.8% higher in current smokers compared with former smokers. Actual long-term bariatric surgery outcomes were not significantly different between the groups. CONCLUSION: Despite advice to quit smoking and temporary quitting before surgery, a considerable group of bariatric surgery patients continues smoking after surgery. These patients were less aware of the beneficial effects of smoking cessation. This study emphasizes the need for better strategies to increase the number of successful cessations.

Outcome expectation and risk tolerance in patients seeking bariatric surgery.

BACKGROUND: Average long-term outcome after laparoscopic Roux-en-Y gastric bypass is 25% total weight loss. The risk of short-term complications (leakage and bleeding), acute internal herniation, and mortality are 4.0%, 2.5%, and .2%, respectively. There is a paucity of evidence on what patients expect in terms of weight loss and to what extent surgical risks are tolerated. OBJECTIVE: To examine the patient's weight loss expectations and acceptance of the morbidity and mortality risk after primary laparoscopic Roux-en-Y gastric bypass. SETTING: Teaching hospital, Amsterdam, the Netherlands. METHODS: Two-hundred patients participated in a standardized survey after completion of an extensive multidisciplinary screening, before surgery. Weight loss expectations, naive assessment, and acceptation of risks of morbidity and mortality were addressed with standard gamble methods. RESULTS: The 200 participants (156 female, 78%) had a mean age of 45.1 years and a mean body mass index of 42.3 kg/m2. Weight loss was overestimated by 151 patients (75.5%), and 79 participants (39.5%) were disappointed with the predicted weight loss. Median accepted risks on short-term complications, acute internal herniation, and mortality were 35.8% (interquartile range, 21.0%-58.0%), 25.1% (interquartile range, 15.9%-50.8%), and 4.5% (interquartile range, 1.0%-10.0%), respectively. CONCLUSION: Patients seeking bariatric surgery seem to have unrealistic weight loss objectives and are willing to accept substantial risks to achieve these goals.

Autocrine negative feedback regulation of lipolysis through sensing of NEFAs by FFAR4/GPR120 in WAT.

OBJECTIVES: Long-chain fatty acids (LCFAs) released from adipocytes inhibit lipolysis through an unclear mechanism. We hypothesized that the LCFA receptor, FFAR4 (GPR120), which is highly expressed in adipocytes, may be involved in this feedback regulation. METHODS AND RESULTS: Liquid chromatography mass spectrometry (LC-MS) analysis of conditioned media from isoproterenol-stimulated primary cultures of murine and human adipocytes demonstrated that most of the released non-esterified free fatty acids (NEFAs) are known agonists for FFAR4. In agreement with this, conditioned medium from isoproterenol-treated adipocytes stimulated signaling strongly in FFAR4 transfected COS-7 cells as opposed to non-transfected control cells. In transfected 3T3-L1 cells, FFAR4 agonism stimulated Gi- and Go-mini G protein binding more strongly than Gq, effects which were blocked by the selective FFAR4 antagonist AH7614. In primary cultures of murine white adipocytes, the synthetic, selective FFAR4 agonist CpdA inhibited isoproterenol-induced intracellular cAMP accumulation in a manner similar to the antilipolytic control agent nicotinic acid acting through another receptor, HCAR2. In vivo, oral gavage with the synthetic, specific FFAR4 agonist CpdB decreased the level of circulating NEFAs in fasting lean mice to a similar degree as nicotinic acid. In agreement with the identified anti-lipolytic effect of FFAR4, plasma NEFAs and glycerol were increased in FFAR4-deficient mice as compared to littermate controls despite having elevated insulin levels, and cAMP accumulation in primary adipocyte cultures was augmented by treatment with the FFAR4 antagonist conceivably by blocking the stimulatory tone of endogenous NEFAs on FFAR4. CONCLUSIONS: In white adipocytes, FFAR4 functions as an NEFA-activated, autocrine, negative feedback regulator of lipolysis by decreasing cAMP though Gi-mediated signaling.

Upper endoscopy after Roux-en-Y gastric bypass: diagnostic yield and factors associated with relevant findings.

BACKGROUND: After laparoscopic Roux-en-Y gastric bypass many patients present with complaints for which an upper endoscopy is performed. However, often no abnormalities are found. OBJECTIVES: To investigate the incidence of relevant findings at upper endoscopy and identify patient characteristics associated with a relevant finding. SETTING: A high-volume bariatric center. METHODS: A retrospective cohort study was performed. All patients presenting with complaints after laparoscopic Roux-en-Y gastric bypass who consequently underwent a diagnostic upper endoscopy were identified from a prospective endoscopic database. Primary outcomes were the number and type of relevant findings at upper endoscopy and its association with patient characteristics. Relevant findings were defined as abnormalities requiring treatment. RESULTS: Ninety-eight (39.2%) of 250 patients had a relevant finding at upper endoscopy, mostly marginal ulcer and stomal stenosis. Male sex (odds ratio [OR] 3.47 [1.12-10.76]), alcohol consumption (OR 7.27 [1.58-33.36]), dysphagia or suspicion of bleeding as referral reason (OR 3.62 [1.54-8.52] and 39.93 [4.96-321.47], respectively, compared with abdominal pain), an abnormal upper gastrointestinal series (OR 6.81 [2.06-22.48]), and no abdominal ultrasound (OR 7.41 [1.48-37.08] compared with a normal ultrasound) were significantly associated with a relevant finding at upper endoscopy. CONCLUSIONS: In this study sex, alcohol consumption, referral reason, and prior imaging studies were associated with a relevant finding at upper endoscopy after laparoscopic Roux-en-Y gastric bypass.

Self-Reported Smoking Compared to Serum Cotinine in Bariatric Surgery Patients: Smoking Is Underreported Before the Operation.

BACKGROUND: Smoking has been associated with postoperative complications and mortality in bariatric surgery. The evidence for smoking is based on self-report and medical charts, which can lead to misclassification and miscalculation of the associations. Determination of cotinine can objectively define nicotine exposure. We determined the accuracy of self-reported smoking compared to cotinine measurement in three phases of the bariatric surgery trajectory. METHODS: Patients in the phase of screening (screening), on the day of surgery (surgery), and more than 18 months after surgery (follow-up) were consecutively selected. Self-reported smoking was registered and serum cotinine was measured. We evaluated the accuracy of self-reported smoking compared to cotinine, and the level of agreement between self-report and cotinine for each phase. RESULTS: In total, 715 patients were included. In the screening, surgery, and follow-up group, 25.6%, 18.0%, and 15.5%, respectively, was smoking based on cotinine. The sensitivity of self-reported smoking was 72.5%, 31.0%, and 93.5% in the screening, surgery, and follow-up group, respectively (p < 0.001). The specificity of self-report was > 95% in all groups (p < 0.02). The level of agreement between self-report and cotinine was 0.778, 0.414, and 0.855 for the screening, surgery, and follow-up group, respectively. CONCLUSIONS: Underreporting of smoking occurs before bariatric surgery, mainly on the day of surgery. Future studies on effects of smoking and smoking cessation in bariatric surgery should include methods taking into account the issue of underreporting.

Hyperspectral imaging for tissue classification, a way toward smart laparoscopic colorectal surgery.

In the last decades, laparoscopic surgery has become the gold standard in patients with colorectal cancer. To overcome the drawback of reduced tactile feedback, real-time tissue classification could be of great benefit. In this ex vivo study, hyperspectral imaging (HSI) was used to distinguish tumor tissue from healthy surrounding tissue. A sample of fat, healthy colorectal wall, and tumor tissue was collected per patient and imaged using two hyperspectral cameras, covering the wavelength range from 400 to 1700 nm. The data were randomly divided into a training (75%) and test (25%) set. After feature reduction, a quadratic classifier and support vector machine were used to distinguish the three tissue types. Tissue samples of 32 patients were imaged using both hyperspectral cameras. The accuracy to distinguish the three tissue types using both hyperspectral cameras was 0.88 (STD = 0.13) on the test dataset. When the accuracy was determined per patient, a mean accuracy of 0.93 (STD = 0.12) was obtained on the test dataset. This study shows the potential of using HSI in colorectal cancer surgery for fast tissue classification, which could improve clinical outcome. Future research should be focused on imaging entire colon/rectum specimen and the translation of the technique to an intraoperative setting.

Can a laparoscopic Roux-en-Y gastric bypass be safely performed by surgical residents in a bariatric center-of-excellence? The learning curve of surgical residents in bariatric surgery.

BACKGROUND: A learning curve (LC) is a graphic display of the number of consecutive procedures performed necessary to reach competence and is defined by complications and duration of surgery (DOS). There is little evidence on the LC of surgical residents in bariatric surgery. Aim of the study is to evaluate whether the laparoscopic Roux-en-Y gastric bypass (LRYGB) can be safely performed by surgical residents, to evaluate the LC of surgical residents for LRYGB and to assess whether surgical residents fit in the LC of the bariatric center which has been established by their proctors. METHODS: Records of all 3389 consecutive primary LRYGB patients, operated between December 2007 and January 2016 in a bariatric center-of-excellence in Amsterdam, were reviewed. Differences in DOS were assessed by means of a linear regression model. Differences in complications (classified as Clavien-Dindo ≥ 2) were evaluated with the χ 2 or the Fisher exact test. Cases were clustered in groups of 70 for comparison and reported for residents with ≥70 cases as primary surgeon. RESULTS: Four surgeons (S1-4) and three residents (R1-3) performed 2690 (88.2%) and 361 (11.8%) of 3051 LRYGBs, respectively. Median (IQR) DOS was 52.0 (42.0-65.0) min for S1-4 versus 53.0 (46.0-63.0) min for R1-3 (p = 0.52). The LC of R1-3 in their first 70 cases (n = 210) differs significantly from the individual (n = 70) LCs of surgeon 1, 2, and 3, with remarkably shorter DOS for the residents (adjusted p < 0.0001; p < 0.001 and p = 0.0002, respectively) and the same amount of surgical complications 5.1% (137/2690) for S1-4 versus 3.0% (11/361) for R1-3 (p = 0.089). CONCLUSION: Laparoscopic Roux-en-Y gastric bypass can be safely performed by surgical residents under supervision of experienced bariatric surgeons. Surgical residents benefit from the experience of their proctors and they fit faultlessly in the LC of the surgical team, as set out by their proctors in a large bariatric center-of-excellence.

Weight-Independent Percentile Chart of 2880 Gastric Bypass Patients: a New Look at Bariatric Weight Loss Results.

BACKGROUND: Percentile charts would be ideal for assessing sufficient weight loss in bariatric surgery. They allow comparing individual results to the outcome of many others, at any postoperative time. Unfortunately, percentile charts can be problematic when comparing unequally heavy peers, a circumstance not uncommon among bariatric patients. We investigate the relevance of this disadvantage and combine new insights to improve the practical use of percentile charts in bariatric surgery. METHODS: Laparoscopic Roux-en-Y gastric bypass outcome expressed with body mass index (BMI), excess weight loss (%EWL), total weight loss (%TWL), and alterable weight loss (%AWL), a new metric rendering outcome independent of baseline BMI, is used to build percentile curves p97/p90/p75/p50/p25/p10/p03 with the lambda-mu-sigma method. We used the %AWL p25 curve as baseline BMI-independent reference for sufficient weight loss and compared it to p25 curves based on common metrics and to traditional criteria ≥50 % EWL, <25 % EWL, and BMI < 35 kg/m2. RESULTS: We operated 2880 patients, with baseline BMI of 43.4 kg/m2, follow-up 71 %, and mean of 23.3 (0-87.6) months. Independent %AWL outcome is presented in one percentile chart. Percentile curves p25/p50/p75 show 40/48/57 % AWL at nadir 15/16/19 months, 35/45/54 % AWL at 3 years, and 30/38/47 % AWL at 7 years. Traditional criteria and p25 curves based on %EWL and BMI match with most sufficient results (high sensitivities), but overlook many insufficient results (low specificities). CONCLUSIONS: We present the first baseline BMI-independent bariatric weight loss percentile chart. It allows comparing heavier patients to lighter peers and vice versa, at any postoperative time, up to 7 years. With these advantages, we compared it to traditional bariatric criteria like ≥50 % EWL and found that they are weak in recognizing insufficient weight loss. The visual aspect of consecutive results plotted on a chart among the percentile curves of peers conveys a strong, intuitive message on the personal progress of postoperative weight loss.

Internal Herniation After Laparoscopic Roux-en-Y Gastric Bypass Surgery: Pitfalls in Diagnosing and the Introduction of the AMSTERDAM Classification.

INTRODUCTION: Internal herniation (IH) probably is the most elusive complication of laparoscopic Roux- en-Y gastric bypass (LRYGB) surgery. This study provides a definition for IH, a diagnosing algorithm, and information on several factors influencing IH formation. METHOD: Baseline characteristics, laboratory findings, imaging studies, operative findings, and follow up data of 1583 patients that underwent LRYGB at our bariatric facility between 2007 and 2013 were recorded. Follow up varied between 3 and 76 months, and 85 % of the data was available for analysis at 12 months. Our surgical technique was standardized. Intermesenteric spaces were not closed until July 2012, where after they were closed. To facilitate comparison, IH cases were matched with controls. RESULTS: Forty patients (2.5 %) had an IH during re-laparoscopy. The modal clinical presentation is acute onset epigastric discomfort, often crampy/colicky in nature. Additional examinations included laboratory testing, abdominal X-ray, abdominal ultrasound, and abdominal CT scanning. Patients who developed an IH lost a significantly higher percentage of their total body weight than their matched controls at every time point. IH incidence was higher in the non-closure group than the closure group. CONCLUSION: The large variation in reported IH incidence is due to the large variation in IH definition. To gain more uniformity in reporting IH prevalence, we propose the use of the AMSTERDAM classification. Post-LRYGB patients with acute onset crampy/colicky epigastric pain should undergo abdominal ultrasound to rule out gallbladder pathology and offered re-laparoscopy with a low threshold. IH incidence is highest among patients with rapid weight loss and non-closure of intermesenteric defects.

Risk Stratification Models: How Well do They Predict Adverse Outcomes in a Large Dutch Bariatric Cohort?

BACKGROUND: Risk prediction models are useful tools for informing patients undergoing bariatric surgery about their risk for complications and correcting outcome reports. The aim of this study is to externally validate risk models assessing complications after laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery. METHODS: All 740 patients who underwent a primary LRYGB between December 2007 and July 2012 were included in the validation cohort. PubMed was systematically searched for risk prediction models. Eight risk models were selected for validation. We classified our complications according to the Clavien-Dindo classification. Predefined criteria of a good model were a non-significant Hosmer and Lemeshow test, Nagelkerke R (2) ≥ 0.10, and c-statistic ≥0.7. RESULTS: There were 85 (7.8 %) grade 1, 54 (7.3 %) grade 2, 5 (0.7 %) grade 3a, 14 (1.9 %) grade 3b, and 14 (1.9 %) grade 4a complications in our validation cohort. Only one model predicted adverse events satisfactorily. This model consisted of one patient-related factor (age) and four surgeon- or center related factors (conversion to open surgery, intraoperative events, the need for additional procedures during LRYGB and the learning curve of the center). CONCLUSIONS: The overall majority of the included risk models are unsuitable for risk prediction. Only one model with an emphasis on surgeon- and center-related factors instead of patient-related factors predicted adverse outcome correctly in our external validation cohort. These findings support the establishment of specialty centers and warn benchmark data institutions not to correct bariatric outcome data by any other patient-related factor than age.

Which baseline weight should be preferred as reference for weight loss results? Insights in bariatric weight loss mechanisms by comparing primary and revision gastric bypass patients.

BACKGROUND: Bariatric weight loss essentially is expressed with reference to the baseline weight, for example, as relative percentages or as absolute body mass index (BMI) points lost from baseline. A different definition of baseline weight would therefore affect all weight loss results. We try to determine which value to prefer for baseline weight in weight loss surgery: the accidental weight at time of operation or the patient-specific steady weight, reflecting a steady personal craving for calories that is independent of the operation. METHODS: Nadir percentage alterable weight loss (%AWL) outcome of all primary gastric bypass patients in our hospital with a 2-year follow-up is compared twice with nadir %AWL outcome of all revision gastric banding-to-bypass patients: relative to their BMI before their banding and before their banding-to-bypass (Mann-Whitney; p < 0.05). RESULTS: Out of 713 gastric bypass patients with a 2-year follow-up, 82 had revision banding-to-bypass. Total mean baseline BMI is 44.1 kg/m2; nadir BMI is 29.2 kg/m2. Difference in mean nadir weight loss between primary (49.4% AWL) and revision patients is not significant if compared to baseline BMI before gastric banding (47.4% AWL) but significant if compared to baseline BMI before revision banding-to-bypass (37.7% AWL). CONCLUSIONS: Revision gastric bypass with removal of gastric banding does not affect the "new" weight after the gastric banding but the "old" weight before the banding. Gastric bypass effectiveness was not added to the gastric banding effectiveness; it replaced it. Therefore, the patient-specific steady weight should be preferred for baseline BMI, reflecting an underlying personal craving for calories that remains constant over time and independent of a bariatric procedure. Baseline BMI can be standardized by using the measured weight at first visit before the primary bariatric procedure, also in revision cases.

The Preceding Surgeon Factor in Bariatric Surgery: a Positive Influence on the Learning Curve of Subsequent Surgeons.

BACKGROUND: The learning curve of laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery has been well investigated. The learning curve is defined by complications and/or by duration of surgery (DOS). Previous studies report an inverse relationship between patient outcome and patient volume. In this study, we investigate whether the learning curve of preceding bariatric surgeons is of additional influence for surgeons who start to perform LRYGB in the same centre. MATERIALS AND METHODS: We retrospectively analysed the records of all 713 consecutive primary LRYGB patients operated in our centre from December 2007 until July 2012. Surgeon 1 and 3 had previous laparoscopic bariatric experience whilst Surgeon 2 and 4 had not. We stratified the data between the four surgeons with different levels of experience and in a chronology of 50 cases. RESULTS: Sixty-seven (9.4 %) complications occurred in the study period. Surgeon 1 had more complications occurring within the first 50 cases than Surgeon 4 (10 versus 1, p < 0.05). There was no difference in complication rate between groups of 50 consecutive cases. None of the patients died. DOS decreased for every consecutive surgeon, irrespective of their experience. The learning curve defined by DOS was steepest for Surgeon 1, followed by Surgeon 2, 3 and 4. CONCLUSION: In this study, we show that the learning curve of the preceding surgeon positively influences the learning curve of latter surgeons, irrespective of their experience. Therefore, the 'preceding surgeon factor' should be taken in account in addition to volume requirements when starting new bariatric facilities.

Fast track care for gastric bypass patients decreases length of stay without increasing complications in an unselected patient cohort.

BACKGROUND: Retrospective studies investigating fast track care involve selected patients. This study evaluates the implementation of fast track care in unselected bariatric patients in a high volume teaching hospital in the Netherlands. METHODS: Consecutive patients who underwent a primary laparoscopic gastric bypass in our center were reviewed in the years before (n = 104) and after implementation of fast track care (n = 360). Fast track involved the banning of tubes/catheters, anesthetic management and early ambulation. Primary outcome was the length of stay. Perioperative times, complications (<30 days), readmissions and prolonged length of stay were secondary outcomes. RESULTS: The median length decreased after implementation of fast track (3 days versus 1 day, p < 0.001). Overall complication rate remained stable after implementation of fast track care (17.3 % versus 18.3 %, not significant). Readmission rate did not differ between groups (4.8 % conventional care versus 8.1 % fast track, not significant). More grades I-IVa complications occurred outside the hospital after the implementation of fast track care (24.8 % versus 51.5 %). Lower age (b = 0.118, 95 % CI: 0.002-0.049, p < 0.05) and the implementation of fast track (b = -0.270, 95 % CI: -1.969 to -0.832, p < 0.001) were the only factors that significantly shortened the length of stay. CONCLUSIONS: Patients that received fast track care had a decreased length of stay. Although more complications occurred after discharge in the fast track care group, this did not lead to adverse outcomes. Fast track does enhance recovery and is suitable for unselected patients. Care providers should select their patients for early discharge and pursue a low threshold for readmission.

Selection of patients for hepatic surgery of colorectal cancer liver metastasis based on genomic aberrations.

BACKGROUND: We investigated whether genomic aberrations in primary colorectal cancer (CRC) can identify patients who are at increased risk of developing additional hepatic recurrence after colorectal liver metastases (CLM) resection. METHODS: Primary tumour DNA from 79 CLM resected patients was analysed for recurrent copy number changes (12x135k NimbleGen(™) aCGH). The cohort was divided into three groups: CLM patients with a recurrence-free survival after hepatic resection of at least 5 years (n = 21), patients who developed intra-hepatic recurrence (n = 32), and patients who developed extrahepatic recurrence (n = 26). By contrasting the primary tumour profiles of recurrence free and the extrahepatic recurrence CLM patients, a classifier, the extra-hepatic recurrence classifier (ERC1), predictive for subsequent extrahepatic-recurrence was developed. RESULTS: The ERC1 had an accuracy of 70 % (95 % confidence interval (CI): 55-82 %, misclassification error 30 %, base error rate: 45 %). This analysis identified a region on Chromosome 12p13 as differentially aberrated between these two groups. The classifier was further optimized by contrasting the extrahepatic recurrence group with the combined group of intrahepatic and no recurrence group, resulting in an extrahepatic prognostic classifier (ERC2) able to classify patients with CLMs suitable for hepatic resection with 74 % accuracy (95 % CI: 62-83 %, misclassification error 26 %, base error rate: 32 %). CONCLUSIONS: Patients with CLM who will develop extrahepatic recurrence may be identified with ERCs based on information in the primary tumour. Risk estimates for the occurrence of extrahepatic metastases may allow a reduction of hepatic resections of colorectal liver metastases for those who are unlikely to develop extrahepatic metastases.

Specific genomic aberrations in primary colorectal cancer are associated with liver metastases.

BACKGROUND: Accurate staging of colorectal cancer (CRC) with clinicopathological parameters is important for predicting prognosis and guiding treatment but provides no information about organ site of metastases. Patterns of genomic aberrations in primary colorectal tumors may reveal a chromosomal signature for organ specific metastases. METHODS: Array Comparative Genomic Hybridization (aCGH) was employed to asses DNA copy number changes in primary colorectal tumors of three distinctive patient groups. This included formalin-fixed, paraffin-embedded tissue of patients who developed liver metastases (LM; n = 36), metastases (PM; n = 37) and a group that remained metastases-free (M0; n = 25).A novel statistical method for identifying recurrent copy number changes, KC-SMART, was used to find specific locations of genomic aberrations specific for various groups. We created a classifier for organ specific metastases based on the aCGH data using Prediction Analysis for Microarrays (PAM). RESULTS: Specifically in the tumors of primary CRC patients who subsequently developed liver metastasis, KC-SMART analysis identified genomic aberrations on chromosome 20q. LM-PAM, a shrunken centroids classifier for liver metastases occurrence, was able to distinguish the LM group from the other groups (M0&PM) with 80% accuracy (78% sensitivity and 86% specificity). The classification is predominantly based on chromosome 20q aberrations. CONCLUSION: Liver specific CRC metastases may be predicted with a high accuracy based on specific genomic aberrations in the primary CRC tumor. The ability to predict the site of metastases is important for improvement of personalized patient management.