Ampullary stenosis and choledocholithiasis post Roux-En-Y gastric bypass: challenges of biliary access and intervention.

BACKGROUND: Ampullary stenosis following Roux-en-Y gastric bypass (RYGB) is increasingly encountered. We describe cases of biliary obstruction from ampullary stenosis and choledocholithiasis to illustrate the associated diagnostic and interventional challenges with this condition. METHODS: We reviewed medical records of patients with prior RYGB who underwent a biliary access procedure or surgery for non-malignant disease from January 2012-December 2018. RESULTS: We identified 15 patients (4 male, 11 female; mean age 53.7 years) who had RYGB on average 11.7 years (range 1-32) years before diagnosis of biliary obstruction. Fourteen patients reported abdominal pain, 5 had nausea/emesis, 12 had elevated liver function tests, and 6 had ascending cholangitis. Mean common bile duct (CBD) diameter at presentation was 16.9 mm (range 4.0-25.0 mm). Operations included 3 transduodenal ampullectomies (2 with biliary bypass), 2 CBD explorations with stone extraction, 1 laparoscopic cholecystectomy alone, 1 Whipple procedure, 1 balloon enteroscopy with sphincterotomy, and 7 transgastric endoscopic retrograde cholangiopancreatography. All ampulla pathology was benign in patients who underwent resection. At follow-up (mean 15.4 months; range 0.23-44.5 months), 12/15 (80%) reported symptom resolution or improvement. DISCUSSION: Ampullary stenosis after RYGB presents challenges for diagnostic evaluation and intervention, often requiring multi-disciplinary expertise. The underlying pathology remains to be elucidated.

Importance of nutrition visits after gastric bypass surgery for American veterans, San Francisco, 2004-2010.

INTRODUCTION: Nutrition counseling is important for veterans undergoing gastric bypass surgery. The aim of this study was to explore the relationship between the number of nutrition visits a patient attended and change in body mass index (BMI) after gastric bypass surgery for the veteran population. METHODS: A retrospective study examined veterans (N = 79) who underwent Roux-en-Y gastric bypass surgery from June 2004 through July 2010. Spearman's correlation and multivariate regression analysis were used to analyze data. RESULTS: A significant correlation was found between the number of postoperative nutrition visits and the change in postsurgery BMI at 2 years (Spearman's ρ = 0.21; P = .017). After adjusting for age, sex, and race, the association between postsurgery nutrition visits and BMI change persisted (ß = 0.255; 95% confidence interval, 0.015-0.581; P = .039). CONCLUSION: Veterans with more nutrition visits following Roux-en-Y gastric bypass surgery experienced greater declines in BMI. This finding underscores the importance of the dietitian on the bariatric surgery team.

Alteration in the gut microbiome is associated with changes in bone metabolism after laparoscopic sleeve gastrectomy.

Laparoscopic sleeve gastrectomy (LSG), the most common bariatric surgical procedure, leads to durable weight loss and improves obesity-related comorbidities. However, it induces abnormalities in bone metabolism. One unexplored potential contributor is the gut microbiome, which influences bone metabolism and is altered after surgery. We characterized the relationship between the gut microbiome and skeletal health in severe obesity and after LSG. In a prospective cohort study, 23 adults with severe obesity underwent skeletal health assessment and stool collection preoperatively and 6 mo after LSG. Gut microbial diversity and composition were characterized using 16S rRNA gene sequencing, and fecal concentrations of short-chain fatty acids (SCFA) were measured with LC-MS/MS. Spearman's correlations and PERMANOVA analyses were applied to assess relationships between the gut microbiome and bone health measures including serum bone turnover markers (C-terminal telopeptide of type 1 collagen [CTx] and procollagen type 1 N-terminal propeptide [P1NP]), areal BMD, intestinal calcium absorption, and calciotropic hormones. Six months after LSG, CTx and P1NP increased (by median 188% and 61%, P < .01) and femoral neck BMD decreased (mean -3.3%, P < .01). Concurrently, there was a decrease in relative abundance of the phylum Firmicutes. Although there were no change in overall microbial diversity or fecal SCFA concentrations after LSG, those with greater within-subject change in gut community microbial composition (ß-diversity) postoperatively had greater increases in P1NP level (ρ = 0.48, P = .02) and greater bone loss at the femoral neck (ρ = -0.43, P = .04). In addition, within-participant shifts in microbial richness/evenness (α-diversity) were associated with changes in IGF-1 levels (ρ = 0.56, P < .01). The lower the postoperative fecal butyrate concentration, the lower the IGF-1 level (ρ = 0.43, P = .04). Meanwhile, the larger the decrease in butyrate concentration, the higher the postoperative CTx (ρ = -0.43, P = .04). These findings suggest that LSG-induced gut microbiome alteration may influence skeletal outcomes postoperatively, and microbial influences on butyrate formation and IGF-1 are possible mechanisms.

Laparoscopic sleeve gastrectomy (LSG), the most common bariatric surgical procedure, is a highly effective treatment for obesity because it produces dramatic weight loss and improves obesity-related medical conditions. However, it also results in abnormalities in bone metabolism. It is important to understand how LSG affects the skeleton, so that bone loss after surgery might be prevented. We studied adult men and women before and 6 mo after LSG, and we explored the relationship between the altered gut bacteria and bone metabolism changes. We found that: Those with greater shifts in their gut bacterial composition had more bone loss.Butyrate, a metabolite produced by gut bacteria from fermentation of dietary fiber, was associated with less bone breakdown and higher IGF-1 level (a bone-building hormone). We conclude that changes in the gut bacteria may contribute to the negative skeletal impact of LSG and reduced butyrate production by the gut bacteria leading to lower IGF-1 levels is a possible mechanism.

Intestinal Calcium Absorption Decreases After Laparoscopic Sleeve Gastrectomy Despite Optimization of Vitamin D Status.

CONTEXT: Laparoscopic sleeve gastrectomy (LSG), now the most commonly performed bariatric operation, is a highly effective treatment for obesity. While Roux-en-Y gastric bypass is known to impair intestinal fractional calcium absorption (FCA) and negatively affect bone metabolism, LSG's effects on calcium homeostasis and bone health have not been well characterized. OBJECTIVE: We determined the effect of LSG on FCA, while maintaining robust 25-hydroxyvitamin D (25OHD) levels and recommended calcium intake. DESIGN, SETTING, PARTICIPANTS: Prospective pre-post observational cohort study of 35 women and men with severe obesity undergoing LSG. MAIN OUTCOMES: FCA was measured preoperatively and 6 months postoperatively with a gold-standard dual stable isotope method. Other measures included calciotropic hormones, bone turnover markers, and bone mineral density (BMD) by dual-energy X-ray absorptiometry and quantitative computed tomography. RESULTS: Mean ± SD FCA decreased from 31.4 ± 15.4% preoperatively to 16.1 ± 12.3% postoperatively (P < 0.01), while median (interquartile range) 25OHD levels were 39 (32-46) ng/mL and 36 (30-46) ng/mL, respectively. Concurrently, median 1,25-dihydroxyvitamin D level increased from 60 (50-82) pg/mL to 86 (72-107) pg/mL (P < 0.01), without significant changes in parathyroid hormone or 24-hour urinary calcium levels. Bone turnover marker levels increased substantially, and areal BMD decreased at the proximal femur. Those with lower postoperative FCA had greater areal BMD loss at the total hip (ρ = 0.45, P < 0.01). CONCLUSIONS: FCA decreases after LSG, with a concurrent rise in bone turnover marker levels and decline in BMD, despite robust 25OHD levels and with recommended calcium intake. Decline in FCA could contribute to negative skeletal effects following LSG.

Prebiotic to Improve Calcium Absorption in Postmenopausal Women After Gastric Bypass: A Randomized Controlled Trial.

CONTEXT: The adverse skeletal effects of Roux-en-Y gastric bypass (RYGB) are partly caused by intestinal calcium absorption decline. Prebiotics, such as soluble corn fiber (SCF), augment colonic calcium absorption in healthy individuals. OBJECTIVE: We tested the effects of SCF on fractional calcium absorption (FCA), biochemical parameters, and the fecal microbiome in a post-RYGB population. METHODS: Randomized, double-blind, placebo-controlled trial of 20 postmenopausal women with history of RYGB a mean 5 years prior; a 2-month course of 20 g/day SCF or maltodextrin placebo was taken orally. The main outcome measure was between-group difference in absolute change in FCA (primary outcome) and was measured with a gold standard dual stable isotope method. Other measures included tolerability, adherence, serum calciotropic hormones and bone turnover markers, and fecal microbial composition via 16S rRNA gene sequencing. RESULTS: Mean FCA ± SD at baseline was low at 5.5 ± 5.1%. Comparing SCF to placebo, there was no between-group difference in mean (95% CI) change in FCA (+3.4 [-6.7, +13.6]%), nor in calciotropic hormones or bone turnover markers. The SCF group had a wider variation in FCA change than placebo (SD 13.4% vs 7.0%). Those with greater change in microbial composition following SCF treatment had greater increase in FCA (r2 = 0.72, P = 0.05). SCF adherence was high, and gastrointestinal symptoms were similar between groups. CONCLUSION: No between-group differences were observed in changes in FCA or calciotropic hormones, but wide CIs suggest a variable impact of SCF that may be due to the degree of gut microbiome alteration. Daily SCF consumption was well tolerated. Larger and longer-term studies are warranted.

Yield and performance characteristics of endoscopic ultrasound-guided fine needle aspiration for diagnosing upper GI tract stromal tumors.

BACKGROUND AND AIMS: EUS-FNA is a means of sampling suspected GI stromal tumors (GIST). However, there are limited published data on factors influencing the sampling yield, and on the performance characteristics of this technique in comparison with resection pathology. We analyzed the yield of EUS-FNA for submucosal lesions of the upper GI tract, and determined the performance characteristics of EUS-FNA for diagnosing GISTs. METHODS: We retrospectively reviewed procedural and pathology data from consecutive patients undergoing EUS-FNA of submucosal lesions from two medical centers over a 4-year period. We analyzed the yield of EUS-FNA, and calculated performance characteristics of EUS-FNA for GIST based on resection pathology. RESULTS: A total of 65 patients underwent EUS-FNA of 66 submucosal lesions during the study period. EUS-FNA was either diagnostic (68%) or suspicious (12%) in a total of 80%. EUS-FNA yielded the following diagnoses: GIST based on cytology and immunohistochemistry (56%), suspected GIST (12%), leiomyoma (9%), other neoplasm (3%), and non-diagnostic (20%). Larger lesion size, gastric location, and presence of on-site cytopathology were associated with higher yield in univariate analysis. Larger needle size and number of FNA passes were not associated with improved yield. Based on resection pathology from 28 specimens, the EUS-FNA performance characteristics for diagnosing GISTs included a sensitivity of 82%, a specificity of 100%, and an overall accuracy of 86%. CONCLUSIONS: EUS-FNA provides a high yield for sampling submucosal lesions and is highly accurate for diagnosing GISTs. EUS-FNA has an important role in the evaluation of suspected GISTs.

Laparoscopic treatment of liver tumours using a two-needle probe bipolar radiofrequency ablation device.

BACKGROUND: Many hepatobiliary centres are increasingly utilizing thermocoagulative devices such as bipolar-radiofrequency ablation (B-RFA). Compared with monopolar-radiofrequency ablation (M-RFA), B-RFA does not require grounding pads, thereby avoiding dermal burn injuries, and does not position probes directly into the tumour but rather on the perimeter. Additionally, B-RFA can precoagulate parenchyma to assist in hepatic resection. Herein, we report our early experience using B-RFA. METHODS: A retrospective review identified 68 patients who underwent M-RFA or B-RFA between June 2004 and September 2010 in an academic centre. Peri-operative metrics were analysed. RESULTS: M-RFA was used to treat 30 patients, whereas B-RFA was used for 17 patients. There were no differences in peri-operative metrics, survival or disease recurrence between M-RFA and B-RFA. Seventeen additional patients underwent B-RFA precoagulation during laparoscopic resection (segmentectomy in eleven patients and multi-segmental resection in six patients). Four patients with multifocal disease underwent procedures that combined B-RFA with resection. CONCLUSIONS: The early experience utilizing B-RFA demonstrates equivalency to M-RFA with respect to peri-operative metrics and survival. Moreover, B-RFA can be utilized to precoagulate tissue during a planned resection, making it not only a useful tool for tumour therapy but also a useful adjunct during surgical resections.

Mesh on the move: a case report of total transmural surgical mesh migration causing bowel obstruction.

We present the case of a 60-year-old man with a complex medical history, presenting to the hospital with generalized weakness and found to be markedly hyperglycemic. Early in the patient's hospital course, he developed abdominal pain and was found to have a small bowel obstruction secondary to intraluminal migrated surgical mesh entrapped in the terminal ileum. The bowel obstruction was relieved surgically with uncomplicated mesh removal and ileocecectomy. Surgical mesh migration is a relatively rare complication of hernia repair and abdominal wall reconstruction, and intraluminal mesh migration is an even more rare variant. Our case demonstrates key clinical and imaging features and serves as an important example of how such cases may present.

The efficacy of medical team training: improved team performance and decreased operating room delays: a detailed analysis of 4863 cases.

OBJECTIVES: Medical team training (MTT) has been touted as a way to improve teamwork and patient safety in the operating room (OR). METHODS: OR personal completed a 1-day intensive MTT training. A standardized briefing/debriefing/perioperative routine was developed, including documentation of OR miscues, delays, and a case score (1-5) assigned by the OR team. A multidisciplinary MTT committee reviewed and rectified any systems problems identified. Debriefing items were analyzed comparing baseline data with 12 and 24-month follow-up. A safety attitudes questionnaire was administered at baseline and 1 year. RESULTS: A total of 4863 MTT debriefings were analyzed. One year following MTT, case delays decreased (23% to 10%, P < 0.0001), mean case score increased (4.07-4.87, P < 0.0005), and both changes were sustained at 24 months. One-year and 24-month follow-up data demonstrated decreased frequency of preoperative delays (16%-7%, P = 0.004), hand-off issues (5.4%-0.3%, P < 0.0001), equipment issues/delays (24%-7%, P < 0.0001), cases with low (<3) case scores (23%-3%, P < 0.0005), and adherence to timing guidelines for prophylactic antibiotic administration improved (85%-97%, P < 0.0001). Surveys documented perception of improved teamwork and patient safety. A major systems issue regarding perioperative medication orders was identified and corrected. CONCLUSIONS: MTT produced sustained improvement in OR team function, including decreased delays and improved case scores. When combined with a high-level debriefing/problem-solving process, MTT can be a foundation for improving OR performance. This is the largest case analysis of MTT and one of the few to document an impact of MTT on objective measures of operating room function and patient safety.

Hyponatremia is associated with more severe biliary disease.

BACKGROUND: Sodium level is an important clinical predictor of complex biliary disease. Hyponatremia has been observed in conjunction with biliary disease, however the nature of this association remains unclear. AIM: To investigate the association between serum sodium and severe biliary disease. METHODS: Of 920 patients with gallstone disease treated at the SFVA Hospital from 1989-2019 were studied. We conducted multivariate analyses of correlation between sodium level and biliary disease severity, the presence/location of biliary bacteria, and other factors. Minimum sodium level pre-intervention was collected. Gallstones, bile, and blood (as relevant) were cultured. Illness severity was characterized: (1) None (no infectious manifestations); (2) Systemic inflammatory response syndrome; (3) Severe illness (gangrenous cholecystitis, cholangitis, necrotizing pancreatitis); and (4) Multiple organ dysfunction syndrome (bacteremia, hypotension, organ failure). Comorbidity was defined using the Charlson Comorbidity Index (CCI). RESULTS: Decreased sodium level significantly correlated with worsening illness severity, ascending bacterial infection, gangrenous changes, elevated CCI score, increasing age, male sex, and glucose. On multivariate analysis, all factors, except age, gender and glucose, independently correlated with sodium level and factors were additive. CONCLUSION: This unique study is the first to explore, with such granularity, the relationship between biliary disease and sodium. No prior studies have examined specific culture and clinical data. It illustrates an inverse, independent correlation between illness severity and sodium. Culture data demonstrate that sodium decreases as infection ascends from gallstone colonization to bactibilia to bacteremia. Patient comorbidity and gangrenous changes also independently correlate with sodium on multivariate analysis. Sodium level is an important clinical indicator of disease severity for patients with biliary disease.

Increases in PYY and uncoupling of bone turnover are associated with loss of bone mass after gastric bypass surgery.

CONTEXT: The gut hormones peptide YY (PYY) and ghrelin mediate in part the metabolic benefits of Roux-en-Y gastric bypass (RYGB) surgery. However, preclinical data suggest these hormones also affect the skeleton and could contribute to postoperative bone loss. OBJECTIVE: We investigated whether changes in fasting serum total PYY and ghrelin were associated with bone turnover marker levels and loss of bone mineral density (BMD) after RYGB. DESIGN, SETTING, PARTICIPANTS: Prospective cohort of adults undergoing RYGB (n=44) at San Francisco academic hospitals. MAIN OUTCOME MEASURES: We analyzed 6-month changes in PYY, ghrelin, bone turnover markers, and BMD by dual-energy x-ray absorptiometry (DXA) and quantitative computed tomography (QCT). We calculated the uncoupling index (UI), reflecting the relative balance of bone resorption and formation. RESULTS: Postoperatively, there was a trend for an increase in PYY (+25pg/mL, p=0.07) and a significant increase in ghrelin (+192pg/mL, p<0.01). PYY changes negatively correlated with changes in spine BMD by QCT (r=-0.36, p=0.02) and bone formation marker P1NP (r=-0.30, p=0.05). Relationships were significant after adjustments for age, sex, and weight loss. No consistent relationships were found between ghrelin and skeletal outcomes. Mean 6-month UI was -3.3; UI correlated with spine BMD loss by QCT (r=0.40, p=0.01). CONCLUSIONS: Postoperative PYY increases were associated with attenuated increases in P1NP and greater declines in spine BMD by QCT. Uncoupling of bone turnover correlated with BMD loss. These findings suggest a role for PYY in loss of bone mass after RYGB and highlight the relationship between intestinal and skeletal metabolism.

Roux-en-Y gastric bypass is a safe and effective option that improves major Co-Morbidities associated with obesity in an older, veteran population.

BACKGROUND: Though over one-third of veterans suffer from obesity and its associated comorbidities, bariatric surgery (deleted: is seldom offered) is less commonly offered than in other populations. METHODS: We reviewed surgical outcomes using CPRS/Vista data of ("deleted 308) 315 Roux-en-Y gastric bypass (RYGB) cases performed at a major VA Medical Center (1995-2017). RESULTS: Patients were 69% male, with an average age 52 (65% over 50), and were followed for an average of 8 years; 158 (51%) underwent laparoscopic surgery, and the remaining open. Outcomes were: 30-day mortality- Open: 1.3%, Lap: 0%; anatomic leak-open: 0.3%, Lap: 0%. A total of 32 (10%) Clavien-Dindo ≥3 complications occurred. At 5 and 15 years, average BMI decreased from 47 preoperatively to 33.3 and 31 respectively, while excess body weight loss was 68%, and 80%, respectively. Co-morbidity resolution rates were between 70 and 80% diabetes, sleep apnea, hyperlipidemia, GERD, (delete - hypertension), and NASH. CONCLUSIONS: RYGB offers sustained, long-term weight loss with significant resolution of major comorbidities in older veterans, with acceptably low morbidity and mortality.

Patient Co-Morbidity and Functional Status Influence the Occurrence of Hospital Acquired Conditions More Strongly than Hospital Factors.

BACKGROUND: Never events (NE) and hospital-acquired conditions (HAC) are used by Medicare/Medicaid Services to define hospital performance measures that dictate payments/penalties. Pre-op patient comorbidity may significantly influence HAC development. METHODS: We studied 8,118,615 patients from the NIS database (2002-2012) who underwent upper/lower gastrointestinal and/or hepatopancreatobiliary procedures. Multivariate analysis, using logistic regression, was used to identify HAC and NE risk factors. RESULTS: A total of 63,762 (0.8%) HAC events and 1645 (0.02%) NE were reported. A total of 99.9% of NE were retained foreign body. Most frequent HAC were: pressure ulcer stage III/IV (36.7%), poor glycemic control (26.9%), vascular catheter-associated infection (20.3%), and catheter-associated urinary tract infection (13.7%). Factors correlating with HAC included: open surgical approach (AOR: 1.25, P < 0.01), high-risk patients with significant comorbidity [severe loss function pre-op (AOR: 6.65, P < 0.01), diabetes with complications (AOR: 2.40, P < 0.01), paraplegia (AOR: 3.14, P < 0.01), metastatic cancer (AOR: 1.30, P < 0.01), age > 70 (AOR: 1.09, P < 0.01)], hospital factors [small vs. large (AOR: 1.07, P < 0.01), non-teaching vs teaching (AOR: 1.10, P < 0.01), private profit vs. non-profit/governmental (AOR: 1.20, P < 0.01)], severe preoperative mortality risk (AOR: 3.48, P < 0.01), and non-elective admission (AOR: 1.38, P < 0.01). HAC were associated with increased: hospitalization length (21 vs 7 days, P < 0.01), hospital charges ($164,803 vs $54,858, P < 0.01), and mortality (8 vs 3%, AOR: 1.14, P < 0.01). CONCLUSION: HAC incidence was highest among patients with severe comorbid conditions. While small, non-teaching, and for-profit hospitals had increased HAC, the strongest HAC risks were non-modifiable patient factors (preoperative loss function, diabetes, paraplegia, advanced age, etc.). This data questions the validity of using HAC as hospital performance measures, since hospitals caring for these complex patients would be unduly penalized. CMS should consider patient comorbidity as a crucial factor influencing HAC development.

Minimal-invasive approach to pancreatoduodenectomy is associated with lower early postoperative morbidity.

OBJECTIVES: We aim to investigate the impact of the operation time for pancreatoduodenectomy (PD) in different surgical approaches. METHODS: The NSQIP database was used to examine the clinical data of patients underwent PD during 2014-2016. RESULTS: We sampled a total of 6151 patients who underwent elective PD. Of these, 452(7.3%) had minimally invasive approaches to PD. Minimally invasive approaches (MIS) to PD was associated with a significant decrease in morbidity of patients (AOR: 0.67, P < 0.01). Following risk adjustment for morbidity predictors, operation length was statistically associated with post-operative morbidity (AOR: 1.002, P < 0.01). Although MIS procedures were significantly longer operations compared to open procedures (443 min vs. 371 min, CI: 53-82 min, P < 0.01), MIS approaches were associated with significantly decreased morbidity in low stage tumors (stage zero-II) (51.3% vs. 56.2%, AOR: 0.72, P = 0.03) and advanced stage disease (stage III-IV) (50% vs. 60.3%, AOR: 0.38, P = 0.04). CONCLUSION: Minimally invasive approaches to PD were associated with decreased post-operative morbidity, even though they were associated with longer operative times. Operation length also significantly correlated with postoperative morbidity.

Changes in Lean Mass, Absolute and Relative Muscle Strength, and Physical Performance After Gastric Bypass Surgery.

Context: Bariatric surgery results in reduced muscle mass as weight is lost, but postoperative changes in muscle strength and performance are incompletely understood. Objective: To examine changes in body composition, strength, physical activity, and physical performance following Roux-en-Y gastric bypass (RYGB). Design, Participants, Outcomes: In a prospective cohort of 47 adults (37 women, 10 men) aged 45 ± 12 years (mean ± SD) with body mass index (BMI) 44 ± 8 kg/m2, we measured body composition by dual-energy X-ray absorptiometry, handgrip strength, physical activity, and physical performance (chair stand time, gait speed, 400-m walk time) before and 6 and 12 months after RYGB. Relative strength was calculated as absolute handgrip strength/BMI and as absolute strength/appendicular lean mass (ALM). Results: Participants experienced substantial 12-month decreases in weight (-37 ± 10 kg or 30% ± 7%), fat mass (-48% ± 12%), and total lean mass (-13% ± 6%). Mean absolute strength declined by 9% ± 17% (P < 0.01). In contrast, relative strength increased by 32% ± 25% (strength/BMI) and 9% ± 20% (strength/ALM) (P < 0.01 for both). There were clinically significant postoperative improvements in all physical performance measures, including mean improvement in gait speed of >0.1 m/s (P < 0.01) and decrease in 400-m walk time of nearly a full minute. Conclusions: In the setting of dramatic weight loss, lean mass and absolute grip strength declined after RYGB. However, relative muscle strength and physical function improved meaningfully and are thus noteworthy positive outcomes of gastric bypass.

Effects of Gastric Bypass Surgery on Bone Mass and Microarchitecture Occur Early and Particularly Impact Postmenopausal Women.

Roux-en-Y gastric bypass (RYGB) surgery is a highly effective treatment for obesity but negatively affects the skeleton. Studies of skeletal effects have generally examined areal bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA), but DXA may be inaccurate in the setting of marked weight loss. Further, as a result of modestly sized samples of mostly premenopausal women and very few men, effects of RYGB by sex and menopausal status are unknown. We prospectively studied the effects of RYGB on skeletal health, including axial and appendicular volumetric BMD and appendicular bone microarchitecture and estimated strength. Obese adults (N = 48; 27 premenopausal and 11 postmenopausal women, 10 men) with mean ± SD body mass index (BMI) 44 ± 7 kg/m2 were assessed before and 6 and 12 months after RYGB. Participants underwent spine and hip DXA, spine QCT, radius and tibia HR-pQCT, and laboratory evaluation. Mean 12-month weight loss was 37 kg (30% of preoperative weight). Overall median 12-month increase in serum collagen type I C-telopeptide (CTx) was 278% (p < 0.0001), with greater increases in postmenopausal than premenopausal women (p = 0.049). Femoral neck BMD by DXA decreased by mean 5.0% and 8.0% over 6 and 12 months (p < 0.0001). Spinal BMD by QCT decreased by mean 6.6% and 8.1% (p < 0.0001); declines were larger among postmenopausal than premenopausal women (11.6% versus 6.0% at 12 months, p = 0.02). Radial and tibial BMD and estimated strength by HR-pQCT declined. At the tibia, detrimental changes in trabecular microarchitecture were apparent at 6 and 12 months. Cortical porosity increased at the radius and tibia, with more dramatic 12-month increases among postmenopausal than premenopausal women or men at the tibia (51.4% versus 18.3% versus 3.0%, p < 0.01 between groups). In conclusion, detrimental effects of RYGB on axial and appendicular bone mass and microarchitecture are detectable as early as 6 months postoperatively. Postmenopausal women are at highest risk for skeletal consequences and may warrant targeted screening or interventions. © 2017 American Society for Bone and Mineral Research.

Gallstones containing bacteria are biofilms: bacterial slime production and ability to form pigment solids determines infection severity and bacteremia.

OBJECTIVE: Gallstone bacteria provide a reservoir for biliary infections. Slime production facilitates adherence, whereas beta-glucuronidase and phospholipase generate colonization surface. These factors facilitate gallstone formation, but their influence on infection severity is unknown. METHODS: Two hundred ninety-two patients were studied. Gallstones, bile, and blood (as applicable) were cultured. Bacteria were tested for beta-glucuronidase/phospholipase production and quantitative slime production. Infection severity was correlated with bacterial factors. RESULTS: Bacteria were present in 43% of cases, 13% with bacteremia. Severe infections correlated directly with beta-glucuronidase/phospholipase (55% with vs 13% without, P < 0.0001), but inversely with slime production (55 vs 8%, slime <75 or >75, P = 0.008). Low slime production and beta-glucuronidase/phospholipase production were additive: Severe infections were present in 76% with both, but 10% with either or none (P < 0.0001). beta-Glucuronidase/phospholipase production facilitated bactibilia (86% with vs 62% without, P = 0.03). Slime production was 19 (+/-8) vs 50 (+/-10) for bacteria that did or did not cause bacteremia (P = 0.004). No bacteria with slime >75 demonstrated bacteremia. CONCLUSIONS: Bacteria-laden gallstones are biofilms whose characteristics influence illness severity. Factors creating colonization surface (beta-glucuronidase/phospholipase) facilitated bacteremia and severe infections; but abundant slime production, while facilitating colonization, inhibited detachment and cholangiovenous reflux. This shows how properties of the gallstone biofilm determine the severity of the associated illness.

Bacteria entombed in the center of cholesterol gallstones induce fewer infectious manifestations than bacteria in the matrix of pigment stones.

PURPOSE: The clinical significance of bacteria in the pigment centers of cholesterol stones is unknown. We compared the infectious manifestations and characteristics of bacteria from pigment stones and predominantly cholesterol stones. METHODS: Three hundred forty patients were studied. Bile was cultured. Gallstones were cultured and examined with scanning electron microscopy. Level of bacterial immunoglobulin G (bile, serum), complement killing, and tumor necrosis factor-alpha production were determined. RESULTS: Twenty-three percent of cholesterol stones and 68% of pigment stones contained bacteria (P < 0.0001). Stone culture correlated with scanning electron microscopy results. Pigment stone bacteria were more often present in bile and blood. Cholesterol stone bacteria caused more severe infections (19%) than sterile stones (0%), but less than pigment stone bacteria (57%) (P < 0.0001). Serum and bile from patients with cholesterol stone bacteria had less bacterial-specific immunoglobulin G. Cholesterol stone bacteria produced more slime. Pigment stone bacteria were more often killed by a patient's serum. Tumor necrosis factor-alpha production of the groups was similar. CONCLUSIONS: Bacteria are readily cultured from cholesterol stones with pigment centers, allowing for analysis of their virulence factors. Bacteria sequestered in cholesterol stones cause infectious manifestations, but less than bacteria in pigment stones. Possibly because of their isolation, cholesterol stone bacteria were less often present in bile and blood, induced less immunoglobulin G, were less often killed by a patient's serum, and demonstrated fewer infectious manifestations than pigment stone bacteria. This is the first study to analyze the clinical relevance of bacteria within cholesterol gallstones.

Bone Marrow Fat Changes After Gastric Bypass Surgery Are Associated With Loss of Bone Mass.

Bone marrow fat is a unique fat depot that may regulate bone metabolism. Marrow fat is increased in states of low bone mass, severe underweight, and diabetes. However, longitudinal effects of weight loss and improved glucose homeostasis on marrow fat are unclear, as is the relationship between marrow fat and bone mineral density (BMD) changes. We hypothesized that after Roux-en-Y gastric bypass (RYGB) surgery, marrow fat changes are associated with BMD loss. We enrolled 30 obese women, stratified by diabetes status. Before and 6 months after RYGB, we measured BMD by dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) and vertebral marrow fat content by magnetic resonance spectroscopy. At baseline, those with higher marrow fat had lower BMD. Postoperatively, total body fat declined dramatically in all participants. Effects of RYGB on marrow fat differed by diabetes status (p = 0.03). Nondiabetic women showed no significant mean change in marrow fat (+1.8%, 95% confidence interval [CI] -1.8% to +5.4%, p = 0.29), although those who lost more total body fat were more likely to have marrow fat increases (r = -0.70, p = 0.01). In contrast, diabetic women demonstrated a mean marrow fat change of -6.5% (95% CI -13.1% to 0%, p = 0.05). Overall, those with greater improvements in hemoglobin A1c had decreases in marrow fat (r = 0.50, p = 0.01). Increases in IGF-1, a potential mediator of the marrow fat-bone relationship, were associated with marrow fat declines (r = -0.40, p = 0.05). Spinal volumetric BMD decreased by 6.4% ± 5.9% (p < 0.01), and femoral neck areal BMD decreased by 4.3% ± 4.1% (p < 0.01). Marrow fat and BMD changes were negatively associated, such that those with marrow fat increases had more BMD loss at both spine (r = -0.58, p < 0.01) and femoral neck (r = -0.49, p = 0.01), independent of age and menopause. Our findings suggest that glucose metabolism and weight loss may influence marrow fat behavior, and marrow fat may be a determinant of bone metabolism. © 2017 American Society for Bone and Mineral Research.

Local resection of ampullary tumors.

There is no consensus on the appropriateness of local resection for ampullary tumors, because malignant recurrence of what were thought to be benign tumors has been reported. This study examined the role of local resection in the management of ampullary tumors. Thirty patients (mean age 66 years) had transduodenal local resections performed at UCSF-Moffitt Hospital or the San Francisco VA Medical Center (February, 1992 to March, 2004). Mean follow-up time was 5.8 years. Preoperative biopsies (obtained in all patients) showed 18 adenomas, four adenomas with dysplasia, five adenomas with atypia, one adenoma with dysplasia and focal adenocarcinoma, and two tumors seen on endoscopy, whose biopsies showed only duodenal mucosa. In comparison with the final pathology findings, the results of frozen section examinations for malignancy in 20 patients, during the operation, were false-negative in three cases. The final pathologic diagnosis was 23 villous adenomas, six adenocarcinomas, and one paraganglioma. On preoperative biopsies, all patients who had high-grade dysplasia and one of five patients with atypia turned out to have invasive adenocarcinoma when the entire specimen was examined postoperatively. Two (33%) adenocarcinomas recurred at a mean of 4 years; both had negative margins at the initial resection. Among the 23 adenomas, three (13%) recurred (all as adenomas) at a mean of 3.2 years; in only one of these cases was the margin positive at the time of resection. Tumor size did not influence recurrence rate. Ampullary tumors with high-grade dysplasia on preoperative biopsy should be treated by pancreaticoduodenectomy because they usually harbor malignancy. Recurrence is too common and unpredictable after local resection of malignant lesions for this to be considered an acceptable alternative to pancreaticoduodenectomy. Ampullary adenomas can be resected locally with good results, but the recurrence rate was 13%, so endoscopic surveillance is indicated postoperatively. Frozen sections were obtained during the operation, but they were less reliable than expected. No adenomas recurred as carcinomas, suggesting that local resection is appropriate for these tumors in the absence of dysplasia or atypia on preoperative biopsies.