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Component separation (CS) techniques have evolved in recent years. How surgeons apply the various CS techniques, anterior component separation (aCS) versus posterior component separation (pCS), by patient and hernia-specific factors remain unknown in the general population. Improving the quality of ventral hernia repair (VHR) on a large scale requires an understanding of current practice variations and how these variations ultimately affect patient care. In this study, we examine the application of CS techniques and the associated short-term outcomes while taking into consideration patient and hernia-specific factors.We retrospectively reviewed a clinically rich statewide hernia registry, the Michigan Surgical Quality Collaborative Hernia Registry, of persons older than 18 y who underwent VHR between January 2020 and July 2021. The exposure of interest was the use of CS. Our primary outcome was a composite end point of 30-d adverse events including any complication, emergency department visit, readmission, and reoperation. Our secondary outcome was surgical site infection (SSI). Multivariable logistic regression examined the association of CS use, 30-d adverse events, and SSI with patient-, hernia-, and operative-specific variables. We performed a sensitivity analysis evaluating for differences in application and outcomes of the posterior and aCS techniques.A total of 1319 patients underwent VHR, with a median age (interquartile range) of 55 y (22), 641 (49%) female patients, and a median body mass index of 32 (9) kg/mThis is the first population-level report of patients undergoing VHR with concurrent posterior or aCS. These data suggest wide variation in the application of CS in VHR and raises a concern for potential overutilization in smaller hernias. Continued analysis of CS application and the associated outcomes, specifically recurrence, is necessary and underway.

Compare adverse outcomes up to 5 years after sleeve gastrectomy and gastric bypass in patients with Medicaid.Sleeve gastrectomy is the most common bariatric operation among patients with Medicaid, however its long-term safety in this population is unknown.Using Medicaid claims, we performed a retrospective cohort study of adult patients who underwent sleeve gastrectomy or gastric bypass from January 1, 2012 to December 31, 2018. Instrumental variables survival analysis was used to estimate the cumulative incidence and heterogeneity of outcomes up to 5 years after surgery.Among 132,788 patients with Medicaid, 84,717 (63.8%) underwent sleeve gastrectomy and 48,071 (36.2%) underwent gastric bypass. 69,225 (52.1%) patients were White, 33,833 (25.5%) were Black, and 29,730 (22.4%) were Hispanic. Compared to gastric bypass, sleeve gastrectomy was associated with a lower 5-year cumulative incidence of mortality (1.29% vs. 2.15%), complications (11.5% vs. 16.2%), hospitalization (43.7% vs. 53.7%), ED use (61.6% vs. 68.2%), and reoperation (18.5% vs. 22.8%), but a higher cumulative incidence of revision (3.3% vs. 2.0%). Compared to White patients, the magnitude of the difference between sleeve and bypass was smaller among Black patients for ED use (5-year aHR 1.01 [95% CI 0.94-1.08] vs. 0.94 [95% CI 0.88-1.00], P0.001) and Hispanic patients for reoperation (5-year aHR 0.95 [95% CI 0.86-1.05] vs. 0.76 [95% CI 0.69-0.83], P0.001).Among patients with Medicaid undergoing bariatric surgery, sleeve gastrectomy was associated with a lower risk of mortality, complications, hospitalization, ED use, and reoperations, but a higher risk of revision compared to gastric bypass. Although the difference between sleeve and bypass was generally similar among White, Black, and Hispanic patients, the magnitude of this difference was smaller among Black patients for ED use and Hispanic patients for reoperation.

As survivorship following kidney transplant continues to improve, so does the probability of intervening on common surgical conditions, such as ventral or incisional hernia, in this population. Ventral hernia management is known to vary across institutions and this variation has an impact on patient outcomes. We sought to evaluate hospital level variation of ventral or incisional hernia repair (VIHR) in the kidney transplant population.We performed a retrospective review of 100% inpatient Medicare claims to identify patients who underwent kidney transplant between 2007 and 2018. The primary outcome was 1- and 3-year ventral or incisional risk- and reliability-adjusted VIHR rates. Patient and hospital characteristics were evaluated across risk- and reliability-adjusted VIHR rate tertiles. Models were adjusted for age, sex, race, and Elixhauser comorbidities.Overall, 139,741 patients underwent kidney transplant during the study period with a mean age (SD) of 51.6 (13.7) years. 84,717 (60.6%) were male, and 72,657 (52.0%) were white. Median follow up time was 5.4 years. 2098 (1.50%) patients underwent VIHR. the 1 year risk- and reliability-adjusted hernia repair rates were 0.49% (95% Conf idence Interval (CI) 0.48-0.51, range 0.31-0.59) in tertile 1, 0.63% (95% CI 0.62-0.63, range 0.59-0.68) in tertile 2, and 0.98 (95% CI 0.91-1.05, range 0.68-2.94) in tertile 3. Accordingly, compared to hospitals in tertile 1, the odds of post-transplant hernia repair tertile 2 hospitals were 1.78 (95% CI 1.37-2.31) and at tertile 3 hospitals 3.53 (95% CI 2.87-4.33).In a large cohort of Medicare patients undergoing kidney transplant, the overall cumulative incidence of hernia repair varied substantially across hospital tertiles. Patient and hospital characteristics varied across tertile, most notably in diabetes and obesity. Future research is needed to understand if program and surgeon level factors are contributing to the observed variation in treatment of this common disease.

A substantial knowledge gap exists in understanding sex as a biological variable for abdominal wall hernia repair, which also extends to hernia repair practices in females of childbearing age. We sought to determine the incidence of mesh repairs in females of childbearing age and to characterize factors associated with mesh use.Using a statewide hernia-specific data registry, we conducted a retrospective study identifying females of childbearing age, defined as 18-44 per CDC guidelines, who underwent clean ventral hernia repair between January 2020 and Dec 2021. The primary outcome was mesh use. Multivariable logistic regression was used to examine factors associated with mesh use. To further delineate whether childbearing status may affect decision to use mesh, we also examined mesh practice stratified by age, comparing women 18 to 44 to those 45 and older.Eight hundred and thirty-six females of childbearing age underwent ventral hernia repair with a mean age of 34.8 (6.2) years. Mesh was used in 547 (65.4%) patients. Mesh use was significantly associated with minimally invasive approach [aOR 29.46 (95% CI 16.30-53.25)], greater hernia width [aOR 1.50 (95% CI 1.20-1.88)], and greater BMI [aOR 1.05 (95% CI 1.03-1.08)]. Age was not significantly associated with mesh use [aOR 1.02 (95% CI 0.99-1.05)]. Compared to 1,461 female patients older than 44 years old, there was no significant association between childbearing age and mesh use [aOR 0.77 (95% CI 0.57-1.04)].Most females of childbearing age had mesh placed during ventral and incisional hernia repair, which was largely associated with hernia size, BMI, and a minimally invasive surgical approach. Neither chronologic patient age nor being of childbearing age were associated with mesh use. Insofar as existing evidence suggests that childbearing status is an important factor in deciding whether to use mesh, these findings suggest that real-world practice may not reflect that evidence.

Despite females accounting for nearly half of ventral and incisional hernia repairs performed each year in the United States, shockingly little attention has been paid to sex disparities in hernia treatment and outcomes. We explored sex-based differences in operative approach and outcomes using a population-level hernia registry.We performed a retrospective review of the Michigan Surgical Quality Collaborative Hernia Registry (MSQC-HR) to identify patients undergoing clean ventral or incisional hernia repair between January 1, 2020 to December 31, 2021. The primary outcomes were risk-adjusted rates of laparoscopic/robotic approach, mesh use, and composite 30-day adverse events stratified by sex. Risk adjustment between sex was performed using all patient, clinical, and hernia characteristics.5269 patients underwent ventral and incisional hernia repair of whom 2295 (43.6%) patients were female. Mean age was 53.9 (14.5) years. Females had slightly larger hernias (3.5 cm vs. 3.0 cm, P 0.001), fewer umbilical hernias (50.9% vs. 73.0%, P 0.001), and a higher prevalence of prior hernia repair (17.9% vs. 13.4%, P 0.001). In a multivariable logistic regression adjusting for differences between males and females, female sex was associated with lower odds of mesh use [aOR 0.62 (95% CI 0.52-0.74)] and higher odds of laparoscopic/robotic repair [aOR 1.26 (95% CI 1.10-1.44)]. In a similar multivariable model, female sex was also associated with significantly higher odds of composite 30-day adverse events [aOR 1.64 (95% CI 1.32-2.02)]. This equates to predicted probabilities of 11.7% (95% CI 10.3-13.0%) vs. 7.6% (95% CI 6.6-8.6%) for adverse events in females compared to males.Despite being younger and having fewer comorbidities, women were more likely to experience adverse events after surgery. Moreover, women were less likely to have mesh placed. Additional work is needed to understand the factors that drive these gender disparities in ventral hernia treatment and outcomes.

One approach to evaluate decision-making is using the concept of decision regret, which measures patient remorse after a healthcare decision. This is particularly important for elective, preference-sensitive conditions with multiple treatment options, such as ventral and inguinal hernia repair. In this study, we assessed decision regret among patients who pursued surgical management of ventral and inguinal hernias.We retrospectively reviewed a statewide registry of adult patients who underwent elective ventral and inguinal hernia repair between January 2017 and March 2020 and completed a validated survey measuring decision regret. 30-day outcomes included complications, emergency department (ED) utilization, readmission, and reoperation. Multivariable logistic regression examined the association of regret with age, sex, race, insurance status, ASA, tobacco use, diabetes, admission status, surgical approach (open vs. laparoscopic vs. robotic), year, and outcomes.8315 patients underwent surgery during the study period with a mean age of 60.5 (14.7) years and 1812 (22%) female patients. Among 2159 patients who underwent ventral hernia repair, 248 (11%) reported regret to undergo surgery, 64 (3%) experienced a complication, 160 (7%) visited an ED, 86 (4%) were readmitted, and 29 (1%) underwent reoperation. Outcomes associated with regret after ventral hernia repair included complications (OR 2.33, 95% CI 1.26-4.29) and readmission (OR 2.67, 95% CI 1.51-4.71). Among 6,156 patients who underwent inguinal hernia repair, 533 (9%) reported regret to undergo surgery, 41 (1%) experienced a complication, 304 (5%) visited an ED, 72 (1%) were readmitted, and 63 (1%) underwent reoperation. Outcomes associated with regret after inguinal hernia repair included ED visits (OR 2.03, 95% CI 1.44-2.87) and readmission (OR 4.23, 95% CI 2.35-7.61).Roughly 1 in 10 patients undergoing hernia repair report regret with their decision to undergo surgery. Developing a better understanding of the factors associated with decision regret after hernia repair may better inform both patients and surgeon decision-making.

Placement of prosthetic mesh during ventral and incisional hernia repair has been shown to reduce the incidence of postoperative hernia recurrence. Consequently, multiple consensus guidelines recommend the use of mesh for ventral hernias of any size. However, the extent to which real-world practice patterns reflect these recommendations is unclear.We performed a retrospective review of the Michigan Surgical Quality Collaborative Hernia Registry (MSQC-HR) to identify patients undergoing clean ventral or incisional hernia repair between January 1, 2020 and December 31, 2021. The primary outcome was mesh use. We used two-step hierarchical logistic regression modeling with empirical Bayes estimates to evaluate the association of hospital-level mesh use with patient, operative, and hernia characteristics.A total of 5262 patients underwent ventral and incisional hernia repair at 65 hospitals with a mean age of 53.8 (14.5) years, 2292 (43.6%) females, and a mean hernia width of 3.2 (3.4) cm. Mean hospital volume was 81 (49) cases. Mesh was used in 4098 (77.9%) patients. At the patient level, hernia width and surgical approach were significantly associated with mesh use. Specifically, mesh use was 6.2% (95% CI 4.8-7.5%) more likely with each additional centimeter of hernia width and 28.0% (95% CI 26.1-29.8%) more likely for minimally invasive repair compared to open repair. At the hospital level, there was wide variation in mesh use, ranging from 38.0% (95% CI 31.5-44.9%) to 96.4% (95% CI 95.3-97.2%). Hospital-level mesh use was not associated with differences in hernia size (β = - 0.003, P = 0.978), surgical approach (β = - 1.109, P = 0.414), or any other patient factors.Despite strong evidence supporting the use of mesh in ventral and incisional hernia repair, there is substantial variation in mesh use between hospitals that is not explained by differences in patient characteristics or operative approach. This suggests that opportunities exist to standardize surgical practice to better align with evidence supporting the use of mesh in the management of these hernias.

Preoperative frailty is a strong predictor of postoperative morbidity in the general surgery population. Despite this, there are a paucity of research examining the effect of frailty on outcomes after ventral hernia repair (VHR), one of the most common abdominal operations in the USA. We examined the association of frailty with short-term postoperative outcomes while accounting for differences in preoperative, operative, and hernia characteristics.We retrospectively reviewed the Michigan Surgery Quality Collaborative Hernia Registry (MSQC-HR) for adult patients who underwent VHR between January 2020 and January 2022. Patient frailty was assessed using the validated 5-factor modified frailty index (mFI5) and categorized as follows: no (mFI5 = 0), moderate (mFI5 = 1), and severe frailty (mFI5 ≥ 2). Our primary outcome was any 30-day complication. Multivariable logistic regression was used to evaluate the association of frailty with outcomes while controlling for patient, operative, and hernia variables.A total of 4406 patients underwent VHR with a mean age (SD) of 55 (15) years, 2015 (46%) females, and 3591 (82%) white patients. The mean (SD) BMI of the cohort was 33 (8) kg/m2. A total of 2077 (47%) patients had no frailty, 1604 (36%) were moderately frail, and 725 (17%) were severely frail. The median hernia size (interquartile range) was 2.5 cm (1.5-4.0 cm). Severe frailty was associated with increased odds of any complication (adjusted Odds Ratio (aOR) 3.12, 95% CI 1.78-5.47), serious complication (aOR 5.25, 95% CI 2.17-13.19), SSI (aOR 3.41, 95% CI 1.58-7.34), and post-discharge adverse events (aOR 1.70, 95% CI 1.24-2.33).After controlling for patient, operative, and hernia characteristics, frailty was independently associated with increased odds of postoperative complications. These findings highlight the importance of preoperative frailty assessment for risk stratification and to inform patient counseling.

To describe national trends in surgical technique and rates of reoperation for recurrence for patients undergoing ventral hernia repair (VHR) in the United States.Surgical options for VHR, including minimally invasive approaches, mesh implantation, and myofascial release, have expanded considerably over the past two decades. Their dissemination and impact on population-level outcomes is not well characterized.We conducted a retrospective cohort study of Medicare beneficiaries undergoing elective, inpatient umbilical, ventral, or incisional hernia repair between 2007 and 2015. Cox proportional hazards models were used to estimate the adjusted proportion of patients who remained free from reoperation for hernia recurrence up to 5 years after surgery.141,261 patients underwent VHR during the study period. Between 2007 and 2018, the use of minimally invasive surgery increased from 2.1% to 22.2%, mesh use increased from 63.2% to 72.5%, and myofascial release increased from 1.8% to 16.3%. Overall, the 5-year incidence of reoperation for recurrence was 14.1% (95% CI 14.0%-14.1%). Over time, patients were more likely to remain free from reoperation for hernia recurrence 5 years after surgery (2007-2009 reoperation-free survival: 84.9% [95% CI 84.8%-84.9%]; 2010-2012 reoperation-free survival: 85.7% [95% CI 85.6%-85.7%]; 2013-2015 reoperation-free survival: 87.8% [95% CI 87.7%-87.9%]).The surgical treatment of ventral and incisional hernias has evolved in recent decades, with more patients undergoing minimally invasive repair, receiving mesh, and undergoing myofascial release. Although our analysis does not address causality, rates of reoperation for hernia recurrence improved slightly contemporaneous with changes in surgical technique.

Despite the advantages of laparoscopic cholecystectomy, major bile duct injury (BDI) rates during this operation remain unacceptably high. In October 2018, SAGES released the Safe Cholecystectomy modules, which define specific strategies to minimize the risk of BDI. This study aims to investigate whether this curriculum can change the knowledge and behaviors of surgeons in practice.Practicing surgeons were recruited from the membership of SAGES and the American College of Surgeons Advisory Council for Rural Surgery. All participants completed a baseline assessment (pre-test) that involved interpreting cholangiograms, troubleshooting difficult cases, and managing BDI. Participants' dissection strategies during cholecystectomy were also compared to the strategies of a panel of 15 experts based on accuracy scores using the Think Like a Surgeon validated web-based platform. Participants were then randomized to complete the Safe Cholecystectomy modules (Safe Chole module group) or participate in usually scheduled CME activities (control group). Both groups completed repeat assessments (post-tests) one month after randomization.Overall, 41 participants were eligible for analysis, including 18 Safe Chole module participants and 23 controls. The two groups had no significant differences in pre-test scores. However, at post-test, Safe Chole module participants made significantly fewer errors managing BDI and interpreting cholangiograms. Safe Chole module participants were less likely to convert to an open operation on the post-test than controls when facing challenging dissections. However, Safe Chole module participants displayed a similar incidence of errors when evaluating adequate critical views of safety.In this randomized-controlled trial, the SAGES Safe Cholecystectomy modules improved surgeons' abilities to interpret cholangiograms and safely manage BDI. Additionally, surgeons who studied the modules were less likely to convert to open during difficult dissections. These data show the power of the Safe Cholecystectomy modules to affect practicing surgeons' behaviors in a measurable and meaningful way.

This Medicare database review tracks the long-term incidence of operative hernia recurrence up to 10 years after surgery among older US adults.

Gastroesophageal reflux (GERD) is common among patients with obesity who undergo bariatric surgery. Although gastric bypass and sleeve gastrectomy are the most common bariatric operations performed in the United States, their long-term comparative effectiveness on GERD medication use is unknown.To compare the long-term effectiveness of gastric bypass and sleeve gastrectomy on use of antireflux medication.National cohort undergoing inpatient bariatric surgery.This is a retrospective study of Medicare beneficiaries undergoing gastric bypass and sleeve gastrectomy between January 1, 2012, and December 31, 2017. A difference-in-differences analysis was conducted to evaluate the differential change in antireflux medication use between groups before and after surgery.A total of 16,640 patients underwent gastric bypass, and 26,724 patients underwent sleeve gastrectomy. Before surgery, GERD medication use was higher among patients who underwent gastric bypass (62.4%; 95% confidence interval [CI]: 62.0%-63.7%) compared with patients who underwent sleeve gastrectomy (60.1%; 95% CI: 59.3%-60.9%). Five years after surgery, GERD medication use was lower in patients who underwent gastric bypass (47.8%; 95% CI: 46.3%-49.3%) compared with patients who underwent sleeve gastrectomy (53.7%; 95% CI: 50.5%-56.9%). The differential decrease from baseline GERD medication use was greater for patients who underwent gastric bypass at 2 years (-4.1 percentage points [pp]; 95% CI: -1.7 to -6.5 pp), 3 years (-4.3 pp; 95% CI: -1.6 to -7.0 pp), 4 years (-6.9 pp; 95% CI: -4.1 to -9.6 pp), and 5 years (-8.3 pp; 95% CI: -3.7 to 12.8 pp) after surgery.Though use of antireflux medication decreased following both procedures, gastric bypass was associated with a greater reduction in antireflux medication use 5 years after surgery compared with sleeve gastrectomy. Understanding the long-term comparative effectiveness of these common bariatric operations may better inform treatment decisions among patients and surgeons.

Instrumental variables can control for selection bias in observational research. However, valid instruments are challenging to identify.To evaluate regional variation in sleeve gastrectomy following insurance coverage implementation as an instrumental variable in comparative effectiveness research.This serial cross-sectional study included adult patients in a national Medicare claims database who underwent sleeve gastrectomy or Roux-en-Y gastric bypass from 2012 to 2017. Data analysis was performed from January to June 2021.Laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass.The association of the instrumental variable with treatment (ie, undergoing sleeve gastrectomy), as well as mortality, complications, emergency department visits, hospitalization, reinterventions, and surgical revision.A total of 76 077 patients underwent bariatric surgery, of whom 44 367 underwent sleeve gastrectomy (mean [SD] age, 56.9 [11.9] years; 32 559 [73.5%] women) and 31 710 underwent gastric bypass (mean (SD) age, 55.9 (11.8) years; 23 750 [74.9%] women). After insurance coverage initiation, there was substantial regional and temporal variation in adoption of sleeve gastrectomy. Prior-year state-level utilization of sleeve gastrectomy was highly associated with undergoing sleeve gastrectomy (Kleibergen-Paap Wald F statistic, 910.3). All but 2 patient characteristics (race and diagnosis of depression) were well-balanced between the top and bottom quartiles of the instrumental variable. Regarding 1-year outcomes, compared with patients undergoing gastric bypass, patients undergoing sleeve gastrectomy had a lower 1-year risk of mortality (0.9%; 95% CI, 0.8%-1.1% vs 1.7%; 95% CI, 1.3%-2.0%), complications (11.6%; 95% CI, 10.9%-12.3% vs 14.1%; 95% CI, 13.0%-15.3%), emergency department visits (48.3%; 95% CI, 46.9%-49.8% vs 53.6%; 95% CI, 52.3%-55.0%), hospitalization (23.4%; 95% CI, 22.4%-24.4% vs 26.5%; 95% CI, 25.1%-28.0%), and reinterventions (8.7%; 95% CI, 8.0%-9.4% vs 12.2%; 95% CI, 11.2%-13.3%). The risk of revision was not different between groups (0.6%; 95% CI, 0.3%-0.8% vs 0.4%; 95% CI, 0.3%-0.6%).In this cross-sectional study of patients undergoing bariatric surgery, there was significant geographic variation in the use of sleeve gastrectomy following initiation of insurance coverage, which served as a strong instrument to compare 2 bariatric surgical procedures. This approach could be applied to other areas of health services research to serve as a complement to clinical trials.

The care of patients who have undergone bariatric surgery is complex and requires a multidisciplinary approach. As such, these patients may be prone to fragmentation of care and differences in healthcare outcomes. We aimed to (1) determine the incidence of fragmentation among patients after Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG), (2) identify risk factors for readmission, and (3) ascertain whether care fragmentation affects outcomes.This is a retrospective cohort study using the National Readmission Database 2016. Patients were included if they had primary bariatric surgery during the index hospitalization using appropriate ICD-10 CM codes. Fragmentation of care was defined as a readmission to a different hospital within 90 days of the index admission. Primary outcome was incidence of fragmentation. Secondary outcomes were impact of fragmentation on (1) in-hospital mortality; (2) resource utilization (length of stay (LOS), total hospitalization charges and costs, in-hospital upper endoscopy (EGD), and abdominal imaging studies; and (3) independent predictors of readmission using multivariate regression analysis.A total of 136,536 subjects were included. 90-day readmission demonstrated a prevalence of fragmentation of 21.1%. Type of surgery was an independent predictor of fragmentation, with RYGB leading to increased risk (OR 1.90 [95% confidence interval (CI) 1.61, 2.25]; p-value 0.0001). RYGB was associated with higher adjusted mean hospitalization costs, which was not explained by increased EGD (OR 0.95, CI 0.68, 1.32) or abdominal imaging (OR 0.52, CI 0.25, 1.06). No differences were found in mortality or LOS.Over 20% of patients following primary bariatric surgery have inpatient readmissions that are fragmented, driven by patients who have undergone RYGB surgery. This may be due to the complexity of this procedure and the need for a multispecialty approach. Additional efforts targeting fragmentation should be made to better coordinate the management of these complex patients and reduce healthcare costs.

Standardization of ventral hernia repair remains elusive. Surgeons use a plethora of techniques, tools, and technology to repair similar defects. Nevertheless, evidence-based principles exist that should be applied to all repairs irrespective of technique allowing standardization and improved outcomes. Six principles are proposed as the basis for complex abdominal wall reconstruction. Resumen La estandarización de la reparación de la hernia ventral sigue siendo difícil de alcanzar. Los cirujanos utilizan una gran cantidad de técnicas, herramientas y tecnología para reparar defectos similares. Sin embargo, existen principios basados en la evidencia que deben aplicarse a todas las reparaciones, independientemente de la técnica que permita la estandarización y mejores resultados. Se proponen seis principios como base para la reconstrucción compleja de la pared abdominal.

A number of studies have demonstrated both low nitric oxide (NO) and l-arginine (l-arg, the substrate for NO synthesis) levels during adult sickle cell vasoocclusive crisis (VOC). L-arg levels, while diminished, are 10-fold higher than the km (3 mM) of endothelial NO synthase (eNOS) and more than sufficient to saturate this enzyme (a state known as the arginine paradox). Diminished l-arg thus cannot directly explain lower NO levels. Two explanations, enhanced arginase activity (catalyzing the conversion of l-arg to ornithine), and inhibition of NOS by increased levels of asymmetric dimethylarginine (ADMA) have been proposed to explain this arginine paradox in VOC. We sought to investigate these mechanisms during adult VOC in the emergency department (ED). L-arg, ornithine, and citrulline (the end product of ADMA metabolism) were measured via ion exchange chromatography from blood obtained from adult ED VOC patients. Citrulline levels were used as an indirect indicator of ADMA and ornithine levels were used as an indicator of arginase activity. Samples from sickle patients in steady-state and from normal healthy volunteers were obtained for comparison. As expected, VOC subjects had significantly lower median l-arg levels (23.16 μM/l, 18.74–29.81 IQR, p