Mammographic density changes in surgical weight loss-an indication for personalized screening.

BACKGROUND: Obesity and high radiologic breast density independently increase breast cancer risk. We evaluated the effect of surgical weight loss on mammographic density (MD). METHODS: Patients undergoing bariatric surgery and screening mammography (MG) were identified, data regarding demographics, comorbidities, calculated and genetic breast cancer risk was collected. Patients had a MG before and after surgery. Fellowship-trained breast radiologists assigned Breast Imaging Reporting and Data System density categories. RESULTS: Patients underwent sleeve gastrectomy (n = 56) or gastric bypass (n = 7), 78% had hypertension, 48% had diabetes. Four had deleterious BRCA mutations, four were calculated high risk. Mean weight loss = 28.7 kg. Mean initial BMI = 44.3 kg/m2 (range:33-77), final BMI = 33.6 kg/m2 (range:20-62;p < 0.01). Density was unchanged in 53, decreased in 1, increased in 9. Of these 9(14%), 5 changed from almost entirely fatty to scattered MD, and 4 changed from scattered MD to heterogeneously dense. Mean weight loss of the 9 with increased MD was greater than the cohort (37.7vs.28.7 kg;p < 0.01). CONCLUSIONS: Surgical weight loss increased MD in 14%. Increased MD masks malignancies, patients may benefit from additional screening based on calculated risk assessments that include MD.

Long-term follow-up after bariatric surgery: a systematic review.

IMPORTANCE: Bariatric surgery is an accepted treatment for obesity. Despite extensive literature, few studies report long-term follow-up in cohorts with adequate retention rates. OBJECTIVE: To assess the quality of evidence and treatment effectiveness 2 years after bariatric procedures for weight loss, type 2 diabetes, hypertension, and hyperlipidemia in severely obese adults. EVIDENCE REVIEW: MEDLINE and Cochrane databases were searched from 1946 through May 15, 2014. Search terms included bariatric surgery, individual bariatric procedures, and obesity. Studies were included if they described outcomes for gastric bypass, gastric band, or sleeve gastrectomy performed on patients with a body mass index of 35 or greater, had more than 2 years of outcome information, and had follow-up measures for at least 80% of the initial cohort. Two investigators reviewed each study and a third resolved study inclusion disagreements. FINDINGS: Of 7371 clinical studies reviewed, 29 studies (0.4%, 7971 patients) met inclusion criteria. All gastric bypass studies (6 prospective cohorts, 5 retrospective cohorts) and sleeve gastrectomy studies (2 retrospective cohorts) had 95% confidence intervals for the reported mean, median, or both exceeding 50% excess weight loss. This amount of excess weight loss occurred in 31% of gastric band studies (9 prospective cohorts, 5 retrospective cohorts). The mean sample-size-weighted percentage of excess weight loss for gastric bypass was 65.7% (n = 3544) vs 45.0% (n = 4109) for gastric band. Nine studies measured comorbidity improvement. For type 2 diabetes (glycated hemoglobin <6.5% without medication), sample-size-weighted remission rates were 66.7% for gastric bypass (n = 428) and 28.6% for gastric band (n = 96). For hypertension (blood pressure <140/90 mm Hg without medication), remission rates were 38.2% for gastric bypass ( n = 808) and 17.4% for gastric band (n = 247). For hyperlipidemia (cholesterol <200 mg/dL, high-density lipoprotein >40 mg/dL, low-density lipoprotein <160 mg/dL, and triglycerides <200 mg/dL), remission rates were 60.4% for gastric bypass (n = 477) and 22.7% for gastric band (n = 97). CONCLUSIONS AND RELEVANCE: Very few bariatric surgery studies report long-term results with sufficient patient follow-up to minimize biased results. Gastric bypass has better outcomes than gastric band procedures for long-term weight loss, type 2 diabetes control and remission, hypertension, and hyperlipidemia. Insufficient evidence exists regarding long-term outcomes for gastric sleeve resections.

Proton pump inhibitor prophylaxis after Roux-en-Y gastric bypass: A national survey of surgeon practices.

BACKGROUND: Proton pump inhibitors (PPIs) are frequently used after Roux-en-Y gastric bypass (RYGB) to prevent marginal ulceration. The optimal duration of PPI treatment after surgery to minimize ulcer development is unclear. OBJECTIVES: Assess bariatric surgeon practice variability regarding postoperative PPI prophylaxis. SETTING: Survey of medical directors of Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program-accredited centers. METHODS: Members of the American Society for Metabolic and Bariatric Surgery research committee developed and administered a web-based anonymous survey in November 2021 to bariatric surgeons of Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program-accredited programs detailing questions related to surgeons' use of PPI after RYGB including patient selection, medication, dosage, and treatment duration. RESULTS: The survey was completed by 112 surgeons (response rate: 52.6%). PPIs were prescribed by 85.4% of surgeons for all patients during their hospitalization, 3.9% for selective patients, and 10.7% not at all. After discharge, 90.3% prescribed PPIs. Pantoprazole was most often used during hospitalization (38.5%), while omeprazole was most prescribed (61.7%) after discharge. The duration of postoperative PPI administration varied; it was 3 months in 43.6%, 1 month in 20.2%, and 6 months in 18.6% of patients. Finally, surgeons' practice setting and case volume were not associated with the duration of prophylactic PPI administration after RYGB. CONCLUSIONS: PPI administration practices vary widely among surgeons after RYGB, which may be related to the limited comparative evidence and guidelines on best duration of PPI administration. Large prospective clinical trials with objective outcome measures are needed to define optimal practices for PPI prophylaxis after RYGB to maximize clinical benefit.

Evaluating the success of American Society of Metabolic and Bariatric Surgery research grants.

BACKGROUND: Since 2004 the American Society of Metabolic and Bariatric Surgery (ASMBS) Foundation has funded competitive proposals by ASMBS members that are administered through the ASMBS Research Committee. These grants are intended to further the knowledge in the field of metabolic and bariatric surgery and support the scholarly growth of its members. OBJECTIVES: The aim of this project was to evaluate the factors associated with grant completion success and barriers encountered by investigators. SETTING: ASMBS. METHODS: Members of the ASMBS Research Committee retrospectively reviewed all awarded research grants since 2004. Information captured included research topic, status of awarded grants, and related publications. Further, a web-based survey of grant recipients was administered exploring the perceived factors of successful completion and barriers encountered. RESULTS: Since 2004, ASMBS members have been awarded 28 research grants funded by the ASMBS Foundation totaling $1,033,000. Fifty-seven percent of awardees responded to the survey. Seventeen projects had been completed at the time of the survey leading to 13 publications, while 11 remain in progress. Seventy percent of non-completed grant recipients indicated that a publication was forthcoming in the next 12 months. Overall, 64% received additional funding. Factors reported to influence successful completion of grants included the effectiveness of the research team, principal investigator (PI) perseverance, PI protected time, institutional support and available resources, and mentorship. Over the last decade, the average time from the award to publication was 2 years. CONCLUSIONS: The research grants awarded by the AMSBS are successful at producing peer reviewed publications at a high rate and often lead to further funding suggesting that they boost the career of their recipients. The identified factors of success can help guide future applicants and the ASMBS Research Committee during its grant selection process.

Venous thromboembolism (VTE) prophylaxis after bariatric surgery: a national survey of MBSAQIP director practices.

BACKGROUND: Venous thromboembolism (VTE) is the most common cause of death following metabolic/bariatric surgery (MBS), with most events occurring after discharge. The available evidence on ideal prophylaxis type, dosage, and duration after discharge is limited. OBJECTIVES: Assess metabolic/bariatric surgeon VTE prophylaxis practices and define existing variability. SETTING: Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP)-accredited centers. METHODS: The members of the ASMBS Research Committee developed and administered a web-based survey to MBSAQIP medical directors and ASMBS members to examine the differences in clinical practice regarding the administration of VTE prophylaxis after MBS. RESULTS: Overall, 264 metabolic/bariatric surgeons (136 medical directors and 128 ASMBS members) participated in the survey. Both mechanical and chemical VTE prophylaxis was used by 97.1% of the participants, knee-high compression devices by 84.7%, enoxaparin (32.4% 40 mg every 24 hours, 22.7% 40 mg every 12 hours, 24.4% adjusted the dose based on body mass index) by 56.5%, and heparin (46.1% 5000 units every 8 hours, 22.6% 5000 units every 12 hours, 20.9% 5000 units once preoperatively) by 38.1%. Most surgeons (81.6%) administered the first dose preoperatively, while the first postoperative dose was given on the evening of surgery by 44% or the next morning by 42.2%. Extended VTE prophylaxis was prescribed for 2 weeks by 38.7% and 4 weeks by 28.9%. CONCLUSIONS: VTE prophylaxis practices vary widely among metabolic/bariatric surgeons. Variability may be related to limited available comparative evidence. Large prospective clinical trials are needed to define optimal practices for VTE risk stratification and prophylaxis in bariatric surgery patients.

Cognition and brain oxygen metabolism improves after bariatric surgery-induced weight loss: A pilot study.

Objective: The primary objectives of this pilot study were to assess cognition and cerebral metabolic rate of oxygen (CMRO2) consumption in people with severe obesity before (baseline), and again, 2- and 14-weeks after sleeve gastrectomy bariatric surgery. Methods: Six people with severe/class 3 obesity (52 ± 10 years, five females, body mass index (BMI) = 41.9 ± 3.9 kg/m2), and 10 normal weight sex- and age-matched healthy controls (HC) (48 ± 6 years, eight females, 22.8 ± 1.9 kg/m2). Global CMRO2 was measured non-invasively using MRI and cognition using the Integneuro testing battery. Results: Following a sleeve gastrectomy induced weight loss of 6.4 ± 2.5 kg (% total-body-weight-lost = 5.4) over two-weeks, cognition total scores improved by 0.8 ± 0.5 T-scores (p=0.03, 15.8% improvement from baseline). Weight loss over 14-weeks post-surgery was 15.4 ± 3.6 kg (% total-body-weight-lost = 13.0%) and cognition improved by 1.1 ± 0.4 (p=0.003, 20.6% improvement from baseline). At 14-weeks, cognition was 6.4 ± 0.7, comparable to 6.0 ± 0.6 observed in the HC group. Baseline CMRO2 was significantly higher compared to the HC (230.4 ± 32.9 vs. 177.9 ± 33.9 µmol O2/100 g/min, p=0.02). Compared to baseline, CMRO2 was 234.3 ± 16.2 µmol O2/100 g/min at 2-weeks after surgery (p=0.8, 1.7% higher) and 217.3 ± 50.4 at 14-weeks (p=0.5, 5.7% lower) after surgery. 14-weeks following surgery, CMRO2 was similar to HC (p=0.17). Conclusion: Sleeve gastrectomy induced weight loss was associated with an increase in cognition and a decrease in CMRO2 observed 14-weeks after surgery. The association between weight loss, improved cognition and CMRO2 decrease should be evaluated in larger future studies.

Impact of bariatric surgery on cerebral vascular reactivity and cognitive function: a non-randomized pilot study.

BACKGROUND: Bariatric surgery is an effective long-term weight loss strategy yielding improvements in neurocognitive function; however, the mechanism(s) responsible for these improvements remains unclear. Here, we assessed the feasibility of using magnetic resonance imaging (MRI) to evaluate whether cerebral vascular reactivity (CVR) is impaired in severely obese bariatric surgery candidates compared with normal weight healthy controls and whether CVR improves following bariatric surgery. We also investigated whether changes in CVR were associated with changes in cognitive function. METHODS: Bariatric surgery candidates (n = 6) were compared with normal weight healthy controls of a similar age (n = 10) at baseline, and then reassessed 2 weeks and 14 weeks following sleeve gastrectomy bariatric surgery. Young reference controls (n = 7) were also studied at baseline to establish the range of normal for each outcome measure. Microvascular and macrovascular CVR to hypercapnia (5% CO2) were assessed using blood-oxygen-level-dependent (BOLD) MRI, and changes in the middle cerebral artery (MCA) cross-sectional area, respectively. Cognitive function was assessed using a validated neurocognitive software. RESULTS: Compliance with the CVR protocol was high. Both macro- and micro-cerebrovascular function were highest in the young reference controls. Cognitive function was lower in obese bariatric surgery candidates compared with normal weight controls, and improved by 17% at 2 weeks and 21% by 14 weeks following bariatric surgery. To our surprise, whole-brain CVR BOLD did not differ between obese bariatric surgery candidates and normal weight controls of similar age (0.184 ± 0.101 vs. 0.192 ± 0.034 %BOLD/mmHgCO2), and did not change after bariatric surgery. In contrast, we observed vasoconstriction of the MCA during hypercapnia in 60% of the obese patients prior to surgery, which appeared to be abolished following bariatric surgery. Improvements in cognitive function were not associated with improvements in either CVR BOLD or MCA vasodilation after bariatric surgery. CONCLUSIONS: Assessing CVR responses to a hypercapnic challenge with MRI was feasible in severely obese bariatric patients. However, no changes in whole-brain BOLD CVR were observed following bariatric surgery despite improvements in cognitive function. We recommend that future large trials assess CVR responses to cognitive tasks (rather than hypercapnia) to better define the mechanisms responsible for cognitive function improvements following bariatric surgery.

Development of ASMBS research agenda for bariatric surgery using the Delphi methodology.

BACKGROUND: While the number of research publications related to bariatric surgery have increased remarkably in the past decade, research efforts remain uncoordinated and have limited focus, and numerous important questions remain unanswered. OBJECTIVE: To generate a research agenda in bariatric surgery. SETTING: National survey. METHODS: The membership of the American Society of Metabolic and Bariatric Surgery (ASMBS) was asked to submit research questions needed to advance the field of bariatric surgery. An expert panel grouped and collated submitted questions and redistributed them back to the membership to rate their importance on a 5-point Likert scale using a 3-round modified Delphi methodology. The top research questions were determined based on provided rankings. RESULTS: Two hundred ninety-two research questions were initially submitted that were collapsed to 59 unique questions. The ratings for the top 40 questions ranged from 2.67-4.33 (overall mean, 3.46). The highest-ranked questions centered on the mechanisms of effectiveness of bariatric surgery for weight loss and diabetes resolution, the underlying etiology of weight recidivism, and predictors of success. CONCLUSIONS: A research agenda for bariatric surgery was developed using the Delphi methodology. This research agenda may enhance the ability of investigators and funding organizations, including the ASMBS, to focus attention to areas most likely to advance the field, and by editors and reviewers to assess the merit and relevance of scientific contributions.

LEAP2 changes with body mass and food intake in humans and mice.

Acyl-ghrelin administration increases food intake, body weight, and blood glucose. In contrast, mice lacking ghrelin or ghrelin receptors (GHSRs) exhibit life-threatening hypoglycemia during starvation-like conditions, but do not consistently exhibit overt metabolic phenotypes when given ad libitum food access. These results, and findings of ghrelin resistance in obese states, imply nutritional state dependence of ghrelin's metabolic actions. Here, we hypothesized that liver-enriched antimicrobial peptide-2 (LEAP2), a recently characterized endogenous GHSR antagonist, blunts ghrelin action during obese states and postprandially. To test this hypothesis, we determined changes in plasma LEAP2 and acyl-ghrelin due to fasting, eating, obesity, Roux-en-Y gastric bypass (RYGB), vertical sleeve gastrectomy (VSG), oral glucose administration, and type 1 diabetes mellitus (T1DM) using humans and/or mice. Our results suggest that plasma LEAP2 is regulated by metabolic status: its levels increased with body mass and blood glucose and decreased with fasting, RYGB, and in postprandial states following VSG. These changes were mostly opposite of those of acyl-ghrelin. Furthermore, using electrophysiology, we showed that LEAP2 both hyperpolarizes and prevents acyl-ghrelin from activating arcuate NPY neurons. We predict that the plasma LEAP2/acyl-ghrelin molar ratio may be a key determinant modulating acyl-ghrelin activity in response to body mass, feeding status, and blood glucose.

Variations of weight loss following gastric bypass and gastric band.

OBJECTIVE: To compare and describe the weight loss outcomes from gastric bypass and gastric band so as to define the variation of excess weight loss (EWL) among individual patients, the time to onset of effect, and the durability of weight loss in severely obese adults. SUMMARY BACKGROUND DATA: Gastric bypass and gastric band are the most common operations for obesity performed in the United States, but few reports have compared these 2 procedures. METHODS: Patients (N = 1733, aged 18-65 years) met National Institutes of Health criteria for obesity surgery and underwent either gastric bypass or gastric band between March 1997 and November 2006. The selection of bypass versus band was based on patient/surgeon discussion. The evaluable sample consisted of 1518 patients. The percentage of EWL was assessed over 2 years. Successful weight loss was defined a priori as > or = 40% EWL in each of four 6-month postoperative measurement periods. The analyses included a mixed model and generalized estimating equation (GEE) model with repeated measures. Odds ratios and descriptive analyses were also provided. RESULTS: Gastric bypass was associated with less individual variation in weight loss than gastric band. Both procedures were associated with a significant EWL benefit (Treatment Group effect P < 0.0001), but they differed in terms of time to effect (Treatment Group x Period interaction effect P < 0.0001). The mean EWL for gastric bypass was greater at each measurement period (6, 12, 18, 24 months) compared with gastric band (P < 0.0001). Furthermore, at each of the postoperative measurement periods within each treatment group (bypass and band), the mean EWL was greater for those who had preoperative body mass index (BMI) < or = 50 kg/m2 than for those who had preoperative BMI > 50 kg/m2 (P < 0.0001). Gastric bypass was consistently associated with a greater likelihood of at least a 40% EWL in each of the 6-month postoperative measurement periods (GEE, P < 0.0001). The odds ratio estimates at months 6, 12, 18, and 24 were 18.2, 20.6, 15.5, and 9.1, respectively. Despite these clinically meaningful outcome differences, nearly all (> or = 93%) bypass and band patients who had > or = 40% EWL at 6, 12, or 18 months postoperatively maintained at least this level of success at 2 years. CONCLUSIONS: Gastric bypass produced more rapid, greater, and more consistent EWL across individuals over a 2-year postoperative period than gastric band.

Metabolic response 4 years after gastric bypass in a complete cohort with type 2 diabetes mellitus.

AIMS: To evaluate the long-term remission rates of type 2 diabetes mellitus and associated comorbidities after gastric bypass surgery in a complete cohort, in a real-life clinic setting. METHODS: A retrospective study of all consecutive patients with type 2 diabetes mellitus who underwent gastric bypass at a Veterans Affairs Medical Center from 2003 to 2010. The main outcome was remission of type 2 diabetes mellitus defined as HbA1c <6.5% (49 mmol/mol) without diabetic medication usage. Secondary outcomes were remission of hypertension and hyperlipidemia, weight loss, and long-term complications four years post-gastric bypass. RESULTS: Eighty-four patients with type 2 diabetes mellitus underwent gastric bypass. Four-year follow-up data were available for 92% (77/84) of patients. The patients (73% male; mean age 54 years) had a mean body mass index of 49 kg/m2 ±â€¯8.3. Hypertension and hyperlipidemia prevalence were 92% and 85%, respectively. The mean total body weight decrease over four years was 35 kg ±â€¯21. Remission of type 2 diabetes mellitus occurred in 15% at 6 months and 49% four years after surgery. Diabetes remission was more likely (OR 3.2; 95% confidence interval 1.2-9.7) in patients not using insulin at baseline. Remission rates were 12% (9/74) for hypertension and 16% (11/68) for hyperlipidemia. Long-term surgical complications included reoperation (11%), incisional hernia (10%) and anastomotic ulcer (10%). Forty-four percent of patients had one or more nutritional complications. CONCLUSIONS: The metabolic effects of gastric bypass are significant and durable for at least four years, even in a predominantly male cohort and real-life clinical setting.

Metabolic syndrome remission after Roux-en-Y gastric bypass or sleeve gastrectomy.

BACKGROUND: Bariatric surgery is known to decrease weight and the prevalence of comorbidities, but there is little evidence on the differential effect of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on the remission of the aggregate outcome, metabolic syndrome, 4 years after surgery. The purpose of this study was to determine the effectiveness of RYGB and SG on metabolic syndrome in veterans. METHODS: We retrospectively reviewed consecutive patients who underwent SG and RYGB at the Dallas Veterans Affairs Medical Center from 2003 to 2012. We determined the effect of both the operations on the remission of metabolic syndrome, its individual components, and medium-term morbidity and mortality. A sensitivity analysis was performed using propensity matching. RESULTS: A total of 266 patients were identified (159 RYGB and 107 SG) with 96% follow-up after 4 years. The mean age of the cohort was 51.4 years; the majority of patients were male (59%) and Caucasian (69%). RYGB patients had a greater mean body mass index and were more likely to have hypertension or hypertriglyceridemia. RYGB was associated with a similar metabolic syndrome remission to SG (37.6% vs 26.8%; P=0.09). The percentage of weight loss was 26.5% after RYGB and 10.8% after SG at 4 years post operation (P<0.01). Predictors of metabolic syndrome persistence were male gender, type 2 diabetes, and low high-density lipoprotein. While both the operations were associated with similar mortality (RYGB 4.4%, SG 2.8%; P=0.74), RYGB was associated with a greater rate of morbidity. CONCLUSION: RYGB and SG seem to be associated with similar remission rates of metabolic syndrome at 4 years. RYGB yields greater weight loss with greater medium-term complications.

Brain imaging demonstrates a reduced neural impact of eating in obesity.

OBJECTIVE: This study investigated functional brain response differences to food in women with BMI either <25 kg/m(2) (lean) or >35 kg/m(2) (severe obesity). DESIGN AND METHODS: Thirty women, 18-65 years old, from academic medical centers participated. Baseline brain perfusion was measured with arterial spin labeling. Brain activity was measured via blood-oxygen-level-dependent functional magnetic resonance imaging in response to food cues, and appeal to cues was rated. Subjective hunger/fullness was reported pre- and post-imaging. After a standard meal, measures were repeated. RESULTS: When fasting, brain perfusion did not differ significantly between groups; and both groups showed significantly increased activity in the neo- and limbic cortices and midbrain compared with baseline (P < 0.05, family-wise-error whole-brain corrected). Once fed, the lean group showed significantly decreased activation in these areas, especially the limbic cortex, whereas the group with severe obesity showed no such decreases (P < 0.05, family-wise-error whole-brain corrected). After eating, appeal ratings of food decreased only in lean women. Within groups, hunger decreased (P < 0.001) and fullness increased (P < 0.001) fasted to fed. CONCLUSIONS: While fasting, brain response to food cues in women did not differ significantly despite BMI. After eating, brain activity quickly diminished in lean women but remained elevated in women with severe obesity. These brain activation findings confirm previous studies.

Psychologic issues in bariatric surgery--the surgeon's perspective.

The consensus that obesity surgery is superior to medical intervention is growing and is supported by abundant evidence. Most patients lose a significant amount of weight, maintain their weightloss long-term, and therefore have improved quality of life with decreased comorbidities and enhanced psychosocial functioning. Despite these benefits from surgery, 5% to 30% of patients lose little weight or are unable to maintain their weight loss postoperatively. This article discusses the psychologic issues involved in bariatric surgery and particularly the absence of psychologically related positive or negative predictors of successful outcome.

Cardiac thromboemboli complicating a stab wound to the heart.

A 27-year-old man was noted to have neurologic deficit 4 days following cardiorrhaphy to repair a penetrating cardiac injury. Cerebral computed tomography scan showed multiple embolic infarcts and two-dimensional echocardiography revealed the source as thrombus in the left ventricle. Although this entity has been described following blunt chest trauma and cardiac contusion, it has not been noted in association with penetrating injury. Intracardiac thrombus with systemic emboli should be considered as a possible complication following cardiorrhaphy for penetrating trauma.

Implementation, construct validity, and benefit of a proficiency-based knot-tying and suturing curriculum.

OBJECTIVES: The aim of this proficiency-based, open knot-tying and suturing study was to evaluate the feasibility of implementing this curriculum within a residency program, and to assess construct validity and educational benefit. METHODS: PGY1 residents (n = 37) were enrolled in an Institutional Review Board (IRB)-approved prospective study that was conducted over a 12-week period. Trainees viewed a video tutorial during orientation and as needed; they self-practiced to proficiency for 12 standardized knot-tying, practiced suturing tasks; performed 1 repetition of each task at baseline and posttesting; and completed questionnaires. RESULTS: Curriculum implementation required 376 person-hours, and material costs were $776. All trainees achieved proficiency within allotted 12 weeks. Overall, trainees completed 141 +/- 80 repetitions over 12.7 +/- 5.3 hours in addition to performing 13.4 +/- 12.4 operations. Baseline trainee and expert performance were significantly different for all 12 tasks and composite score (732 +/- 294 vs 1488 +/- 26, p < 0.001), which supported construct validity. Baseline trainees demonstrated significant improvement at posttesting according to composite scores (732 +/- 294 vs 1503 +/- 131, p < 0.001), which validates skill acquisition. CONCLUSIONS: Implementation of this proficiency-based curriculum within the constraints of a residency program is feasible. This curriculum is educationally beneficial and cost effective; our data support construct validity. Evaluation of transferability to the operating room and more widespread adoption of this curriculum are warranted.