Quality of life measures and cost analysis of biologic versus synthetic mesh for ventral hernia repair: The Preventing Recurrence in Clean and Contaminated Hernias randomized clinical trial

BACKGROUND

Although the most durable method for ventral hernia repairs involves using mesh, whether to use biologic mesh versus synthetic mesh remains controversial. This study aimed to compare synthetic and biologic meshes with respect to patient-reported quality of life scores and costs after ventral hernia repair surgeries.

METHODS

This study is part of the Preventing Recurrence in Clean and Contaminated Hernias (PRICE) pragmatic randomized control trial conducted from March 2014 through October 2018. Patients were randomized 1:1 to undergo ventral hernia repair using either a biologic or synthetic mesh. The coprimary outcomes were 2-year changes in Visual Analog Scale, Activities Assessment Scale, Hernia-Related Quality-of-Life Survey, and Short-Form 36 Health Survey (SF-36) quality-of-life scores from repair. The secondary outcome was the overall cost per patient.

RESULTS

Among the 165 patients included in the study, 82 were randomized to biologic meshes and 83 to synthetic meshes. There were no significant differences in the performance between the 2 mesh types with regard to quality-of-life measures using a mixed model approach. This result was consistent even when performing subgroup analysis based on wound contamination. However, nonparametric tests comparing the differences in quality-of-life measures from preoperative to 24-month postoperative timepoints revealed that the synthetic mesh group showed a greater reduction in disability than biologic mesh for the SF-36 (median [interquartile range] of 20 [5-30] vs 6 [1-20], P = .025). This difference was due to reductions in the physical role limitations (62 [0-100] vs 0 [0-50], P = .018) and the pain (38 [12-50] vs 12 [0-25], P = .012) domains of the SF-36. Overall cost per patient was greater for biologic meshes (mean [95% confidence interval] of $80,420 [$66,485-$94,355] vs $61,036 [$48,946-$73,125], P = .038), regardless of insurance type.

CONCLUSION

In this randomized clinical trial, there were no differences in changes in quality-of-life scores at the 2-year timepoint except for the SF-36, where the synthetic mesh may be associated with less pain and physical role limitations than the biologic mesh. Overall costs per patient were less for synthetic than biologic mesh.

Biologic Versus Synthetic Mesh in Ventral Hernia Repair: Participant-Level Analysis of Two Randomized Controlled Trials at Twenty-Four to Thirty-Six Months

Background: Biologic mesh has been used increasingly in complex ventral hernia repair despite limited evidence at low risk of bias supporting its use. Patients and Methods: We performed a participant-level analysis of published randomized controlled trials (RCTs) comparing biologic to synthetic mesh with complex ventral hernia repair at 24 to 36 months. Primary outcome was major complication (composite of mesh infection, recurrence, reoperation, or death) at 24 to 36 months post-operative. Secondary outcomes included length of index hospital stay, surgical site occurrence, surgical site infection, and death. Outcomes were assessed using both frequentist and Bayesian generalized linear regression models. Results: A total of 252 patients from two RCTs were included, 126 patients randomized to the intervention arm of biologic and 126 patients to the control of synthetic mesh with median follow-up of 29 (23, 38) months. Major complication occurred in 33 (33%) patients randomized to biologic, and 39 (38%) patients randomized to synthetic mesh, (relative risk [RR] 0.91, 95% confidence interval [CI] 0.63-1.31; p value = 0.600). Bayesian analysis demonstrated that compared with synthetic mesh, biologic mesh had similar probability of major complications at 24 to 36 months post-operative. The remainder of outcomes demonstrated slight benefit with synthetic mesh as opposed to biologic mesh except for mesh infection. However, under a frequentist framework, no outcome was statistically different. Conclusions: In patients undergoing open ventral hernia repair, there was no benefit for patients receiving biologic versus synthetic mesh at 24 to 36 months post-operative.

Updated guideline for closure of abdominal wall incisions from the European and American Hernia Societies

BACKGROUND

Incisional hernia is a frequent complication of abdominal wall incision. Surgical technique is an important risk factor for the development of incisional hernia. The aim of these updated guidelines was to provide recommendations to decrease the incidence of incisional hernia.

METHODS

A systematic literature search of MEDLINE, Embase, and Cochrane CENTRAL was performed on 22 January 2022. The Scottish Intercollegiate Guidelines Network instrument was used to evaluate systematic reviews and meta-analyses, RCTs, and cohort studies. The GRADE approach (Grading of Recommendations, Assessment, Development and Evaluation) was used to appraise the certainty of the evidence. The guidelines group consisted of surgical specialists, a biomedical information specialist, certified guideline methodologist, and patient representative.

RESULTS

Thirty-nine papers were included covering seven key questions, and weak recommendations were made for all of these. Laparoscopic surgery and non-midline incisions are suggested to be preferred when safe and feasible. In laparoscopic surgery, suturing the fascial defect of trocar sites of 10 mm and larger is advised, especially after single-incision laparoscopic surgery and at the umbilicus. For closure of an elective midline laparotomy, a continuous small-bites suturing technique with a slowly absorbable suture is suggested. Prophylactic mesh augmentation after elective midline laparotomy can be considered to reduce the risk of incisional hernia; a permanent synthetic mesh in either the onlay or retromuscular position is advised.

CONCLUSION

These updated guidelines may help surgeons in selecting the optimal approach and location of abdominal wall incisions.

Innovations for Incisional Hernia Prevention

Incisional hernias are the most frequent long-term complication of abdominal surgery, resulting in considerable patient morbidity and increased health care costs. These hernias frequently result from excessive tension concentrated at points along the suture line of the abdominal closure. While ample research is focused on developing improved repair materials, the optimal solution to the problem of incisional hernias is prevention. Accordingly, some investigators have postulated that incisional hernias can be prevented by distributing tension more evenly along the fascial closure. Herein we describe two novel and ingenious strategies for the improved distribution of tension when closing abdomens (T-Line® Hernia Mesh and the REBUILD Bioabsorbable™) that were conceived of and developed by surgeons.

Cost-Effectiveness Analysis of Inguinal Hernia Repair With Mesh Performed by Surgeons and Medical Doctors in Ghana

OBJECTIVES

Task-sharing is the pragmatic sharing of tasks between providers with different levels of training. To our knowledge, no study has examined the cost-effectiveness of surgical task-sharing of hernia repair in a low-resource setting. This study has aimed to evaluate and compare the cost-effectiveness of mesh repair performed by Ghanaian surgeons and medical doctors (MDs) following a standardized training program.

METHODS

This cost-effectiveness analysis included data for 223 operations on adult men with primary reducible inguinal hernia. Cost per surgery was calculated from the healthcare system perspective. Disability weights were calculated using pre- and postoperative pain scores and benchmarks from the Global Burden of Disease Study 2017.

RESULTS

The mean cost/disability-adjusted life-year (DALY) averted in the surgeon group was 444.9 United States dollars (USD) (95% confidence interval [CI] 221.2-668.5) and 278.9 USD (95% CI 199.3-358.5) in the MD group (P = .168), indicating that the operation is very cost-effective when performed by both providers. The incremental cost/DALY averted showed that task-sharing with MDs is also very cost-effective (95% bootstrap CI -436.7 to 454.9). The analysis found that increasing provider salaries is cost-effective if productivity remains high. When only symptomatic cases were analyzed, the mean cost/DALY averted reduced to 232.0 USD (95% CI 17.1-446.8) for the surgeon group and 129.7 USD (95% CI 79.6-179.8) for the MD group (P = .348), and the incremental cost/DALY averted increased by 45% but remained robust.

CONCLUSIONS

Elective inguinal hernia repair with mesh performed by Ghanaian surgeons and MDs is a low-cost procedure and very cost-effective in the context of the study. To maximize cost-effectiveness, symptomatic patients should be prioritized over asymptomatic patients and a high level of productivity should be maintained.

Early-life inflammation primes a T helper 2 cell-fibroblast niche in skin

Inflammation early in life can prime the local immune milieu of peripheral tissues, which can cause lasting changes in immunological tone that confer disease protection or susceptibility¹. The cellular and molecular mechanisms that prompt changes in immune tone in many nonlymphoid tissues remain largely unknown. Here we find that time-limited neonatal inflammation induced by a transient reduction in neonatal regulatory T cells causes a dysregulation of subcutaneous tissue in mouse skin. This is accompanied by the selective accumulation of type 2 helper T (T_H2) cells within a distinct microanatomical niche. T_H2 cells are maintained into adulthood through interactions with a fibroblast population in skin fascia that we refer to as T_H2-interacting fascial fibroblasts (TIFFs), which expand in response to T_H2 cytokines to form subcutaneous fibrous bands. Activation of the T_H2-TIFF niche due to neonatal inflammation primes the skin for altered reparative responses to wounding. Furthermore, we identify fibroblasts in healthy human skin that express the TIFF transcriptional signature and detect these cells at high levels in eosinophilic fasciitis, an orphan disease characterized by inflammation and fibrosis of the skin fascia. Taken together, these data define a previously unidentified T_H2 cell niche in skin and functionally characterize a disease-associated fibroblast population. The results also suggest a mechanism of immunological priming whereby inflammation early in life creates networks between adaptive immune cells and stromal cells to establish an immunological set-point in tissues that is maintained throughout life.

Layilin Anchors Regulatory T Cells in Skin

Regulatory T cells (Tregs) reside in nonlymphoid tissues where they carry out unique functions. The molecular mechanisms responsible for Treg accumulation and maintenance in these tissues are relatively unknown. Using an unbiased discovery approach, we identified LAYN (layilin), a C-type lectin-like receptor, to be preferentially and highly expressed on a subset of activated Tregs in healthy and diseased human skin. Expression of layilin on Tregs was induced by TCR-mediated activation in the presence of IL-2 or TGF-β. Mice with a conditional deletion of layilin in Tregs had reduced accumulation of these cells in tumors. However, these animals somewhat paradoxically had enhanced immune regulation in the tumor microenvironment, resulting in increased tumor growth. Mechanistically, layilin expression on Tregs had a minimal effect on their activation and suppressive capacity in vitro. However, expression of this molecule resulted in a cumulative anchoring effect on Treg dynamic motility in vivo. Taken together, our results suggest a model whereby layilin facilitates Treg adhesion in skin and, in doing so, limits their suppressive capacity. These findings uncover a unique mechanism whereby reduced Treg motility acts to limit immune regulation in nonlymphoid organs and may help guide strategies to exploit this phenomenon for therapeutic benefit.

Burden of Ionizing Radiation in the Diagnosis and Management of Necrotizing Pancreatitis

INTRODUCTION

A step-up endoscopic or percutaneous approach improves outcomes in necrotizing pancreatitis (NP). However, these require multiple radiographic studies and fluoroscopic procedures, which use low-dose ionizing radiation. The cumulative radiation exposure for treatment of NP has not been well defined.

METHODS

We conducted a retrospective study of consecutive patients with NP admitted to University of California San Francisco Medical Center from January 2011 to June 2019. We calculated effective doses for fluoroscopic procedures using the dose area product and used the National Cancer Institute tool for computed tomography studies. The primary outcome was the cumulative effective dose (CED). Multivariable logistic regression was used to evaluate risk factors of high exposure (CED > 500 mSv).

RESULTS

One hundred seventy-one patients with NP (mean follow-up 40 ± 18 months) underwent a median of 7 (interquartile range [IQR] 5-11) computed tomography scans and 7 (IQR 5-12) fluoroscopic procedures. The median CED was 274 mSv (IQR 177-245) and 30% (51) of patients received high exposure. Risk factors of high exposure include multiorgan failure (aOR 3.47, 95%-CI: 1.53-9.88, P = 0.003), infected necrosis (adjusted odds ratio [aOR] 3.89 95%-CI:1.53-9.88, P = 0.005), and step-up endoscopic approach (aOR 1.86, 95%-CI: 1.41-1.84, P = 0.001) when compared with step-up percutaneous approach.

DISCUSSION

Patients with NP were exposed to a substantial amount of ionizing radiation (257 mSv) as a part of their treatment, and 30% received more than 500 mSv, which corresponds with a 5% increase in lifetime cancer risk. Severity of NP and a step-up endoscopic approach were associated with CED > 500 mSv. Further studies are needed to help develop low-radiation treatment protocols for NP, particularly in patients receiving endoscopic therapy.

Enhanced Stress Resilience Training in Surgeons: Iterative Adaptation and Biopsychosocial Effects in 2 Small Randomized Trials

OBJECTIVE

To determine the effects of ESRT (an iteratively adapted and tailored MBI) on perceived stress, executive cognitive function, psychosocial well-being (ie, burnout, mindfulness), and pro-inflammatory gene expression in surgical (ESRT-1) and mixed specialty (ESRT-2) PGY-1 volunteers.

SUMMARY OF BACKGROUND AND DATA

Tailored MBIs have proven beneficial in multiple high-stress and high-performance populations. In surgeons, tailored MBIs have been shown to be feasible and potentially beneficial, but whether mindfulness-based cognitive training can improve perceived stress, executive function, well-being or physiological distress in surgical and nonsurgical trainees is unknown.

METHODS

In 2 small single-institution randomized clinical trials, ESRT, a tailored mindfulness-based cognitive training program, was administered and iteratively adapted for first-year surgical (ESRT-1, 8 weekly, 2-hour classes, n = 44) and mixed specialty (ESRT-2, 6 weekly, 90-minute classes, n = 45) resident trainees. Primary and secondary outcomes were, respectively, perceived stress and executive function. Other prespecified outcomes were burnout (assessed via Maslach Burnout Inventory), mindfulness (assessed via Cognitive Affective Mindfulness Scale - Revised), and pro-inflammatory gene expression (assessed through the leukocyte transcriptome profile "conserved transcriptional response to adversity").

RESULTS

Neither version of ESRT appeared to affect perceived stress. Higher executive function and mindfulness scores were seen in ESRT-1, and lower emotional exhaustion and depersonalization scores in ESRT-2, at pre-/postintervention and/or 50-week follow-up (ESRT-1) or at 32-week follow-up (ESRT-2), compared to controls. Pooled analysis of both trials found ESRT-treated participants had reduced pro-inflammatory RNA expression compared to controls.

CONCLUSIONS

This pilot work suggests ESRT can variably benefit executive function, burnout, and physiologic distress in PGY-1 trainees, with potential for tailoring to optimize effects.

Upper Gastrointestinal Endoscopy in an Academic General Surgical Program: Implications for Acute Care Surgeons

Background. Esophagogastroduodenoscopy (EGD) is an important tool in the evolving specialty of acute care surgery (ACS). Understanding the types of nonelective EGDs performed by ACS groups is important for the development of ACS programs and the training of future general surgeons. Methods. We conducted a retrospective review of all EGDs performed by ACS surgeons at a single urban academic center over a 5-year period (January 2013-December 2018). Results. A total of 495 EGDs were performed, of which 129 (26%) were urgent, nonelective procedures. Patients who underwent urgent EGD were younger than those who underwent elective procedures (median 55 vs 60 years, P = .03), had higher American Society of Anesthesiologists (ASA) classes (median ASA 3 vs 2, P = .0002), and longer hospital stays (median 5 days vs 0 days, P < .0001). The most common indications for urgent endoscopies were the management of leak, dysphagia, or stenosis in patients with a history of foregut surgery, followed by the management of esophageal perforation. The success rate of endoscopic therapy was high (median 88%, interquartile range (IQR) 78-89%). However, some patients required multiple interventions (median 1, IQR 1-3), and patients treated for leaks were less likely to be successfully treated with endoscopic therapy alone than patients treated for other indications (success rate 65% vs 88%, P = .003). Conclusions. Our experience suggests that EGD has an important role in current ACS practice and that endoscopic management is safe and effective in a range of urgent surgical scenarios. Future ACS surgeons should be facile with endoscopic techniques.

Outcomes After Inguinal Hernia Repair With Mesh Performed by Medical Doctors and Surgeons in Ghana

Importance

Inguinal hernia is the most common general surgical condition in the world. Although task sharing of surgical care with nonsurgeons represents one method to increase access to essential surgery, the safety and outcomes of this strategy are not well described for hernia repair.

Objective

To compare outcomes after inguinal hernia repair with mesh performed by medical doctors and surgeons in Ghana.

Design, Setting, and Participants

This prospective cohort study was conducted from February 15, 2017, to September 17, 2018, at the Volta Regional Hospital in Ho, Ghana. Following successful completion of a training course, 3 medical doctors and 2 surgeons performed inguinal hernia repair with mesh according to the Lichtenstein technique on 242 men with primary, reducible inguinal hernia.

Main Outcomes and Measures

The primary end point was hernia recurrence at 1 year. The noninferiority limit was set at 5 percentage points. Secondary end points included postoperative complications at 2 weeks and patient satisfaction, pain, and self-assessed health status at 1 year.

Results

Two-hundred forty-two patients were included; 119 men underwent operations performed by medical doctors and 123 men underwent operations performed by surgeons. Preoperative patient characteristics were similar in both groups. Two-hundred thirty-seven patients (97.9%) were seen at follow-up at 2 weeks, and 223 patients (92.1%) were seen at follow-up at 1 year. The absolute difference in recurrence rate between the medical doctor group (1 [0.9%]) and the surgeon group (3 [2.8%]) was -1.9 (1-tailed 95% CI, -4.8; P < .001), demonstrating noninferiority of the medical doctors. There were no statistically significant differences in postoperative complications (34 [29.1%] vs 29 [24.2%]), patient satisfaction (112 [98.2%] vs 108 [99.1%]), severe chronic pain (1 [0.9%] vs 4 [3.7%]), or self-assessed health (85.9 vs 83.7 of 100) for medical doctors and surgeons.

Conclusions and Relevance

This study shows that medical doctors can be trained to perform elective inguinal hernia repair with mesh in men with good results and high patient satisfaction in a low-resource setting. This finding supports surgical task sharing to combat the global burden of hernia disease.

Regulatory T cells use arginase 2 to enhance their metabolic fitness in tissues

Distinct subsets of Tregs reside in nonlymphoid tissues where they mediate unique functions. To interrogate the biology of tissue Tregs in human health and disease, we phenotypically and functionally compared healthy skin Tregs with those in peripheral blood, inflamed psoriatic skin, and metastatic melanoma. The mitochondrial enzyme, arginase 2 (ARG2), was preferentially expressed in Tregs in healthy skin, increased in Tregs in metastatic melanoma, and reduced in Tregs from psoriatic skin. ARG2 enhanced Treg suppressive capacity in vitro and conferred a selective advantage for accumulation in inflamed tissues in vivo. CRISPR-mediated deletion of this gene in primary human Tregs was sufficient to skew away from a tissue Treg transcriptional signature. Notably, the inhibition of ARG2 increased mTOR signaling, whereas the overexpression of this enzyme suppressed it. Taken together, our results suggest that Tregs express ARG2 in human tissues to both regulate inflammation and enhance their metabolic fitness.

Integrating Robotic Technology Into Resident Training: Challenges and Recommendations From the Front Lines

PURPOSE

To develop recommendations for improving the integration of robotic technology into today's apprentice-based resident training.

METHOD

During a national meeting in 2017, 24 robotic surgeons were interviewed about their experiences integrating robotic technology into resident training. Qualitative thematic analysis of interview notes and recordings revealed themes related to challenges and recommendations.

RESULTS

Four themes emerged, each corresponding to a general recommendation for integrating robotic technology into training. The first, surgical techniques versus tools, contrasts faculty's sequential mastery-surgical techniques first, then the robotic tool-with residents' simultaneous learning. The recommendation is to create separate learning opportunities for focused skill acquisition. The second theme, timing of exposure to the robotic tool, describes trainees' initial focus on tool use for basic surgical steps. The recommendation is to increase access to basic robotic cases. The third theme covers the relationship of laparoscopic and robotic surgery. The recommendation is to emphasize similar and dissimilar features during all minimally invasive surgical cases. The fourth theme, use of the dual console (which enables two consoles to operate the robot, the primary determines the secondary's functionality), highlights the unique teaching opportunities this console creates. The recommendation is for surgeons to give verbal guidance so residents completely understand surgical techniques.

CONCLUSIONS

Surgical educators should consider technique versus tool, timing of exposure to the tool, overlapping and varying features of robotic and laparoscopic surgery, and use of the dual console as they develop curricula to ensure thorough acquisition and synthesis of all elements of robotic surgery.

Practice Patterns and Attitudes of Surgeons on the Use of Prophylactic Mesh to Prevent Parastola Hernia: A Cross-sectional Survey

Information about surgeons' attitudes toward using prophylactic mesh (PM) for parastomal hernia (PSH) prevention is limited.

PURPOSE

A survey was conducted to assess attitudes/beliefs and surgical practice related to PM use for preventing PSH.

METHODS

A cross-sectional email survey was conducted during April 2017 among members (surgeons) of the American Hernia Society, European Hernia Society, and International Hernia Collaboration. Survey items included participant demographic characteristics, knowledge about the incidence of PSH, number of permanent stomas created annually, beliefs/opinions (knowledge/interest) regarding the use of PM, and surgical practices (mesh type and position). Data were collected and tallied using SurveyMonkey. Descriptive statistics were used to analyze the data.

RESULTS

Of the 5445 emails sent, 497 responses were received, 235 (47.3%) from the United States and 197 (39.6%) from Europe. The majority of participants were general surgeons (371, 74.6%); a small percentage were colorectal surgeons (37, 7.4%). Most respondents (353, 71.0%) reported at least 11 years of surgical experience, with 37.3% reporting >20 years' experience. The majority of respondents (340, 68.4%) created <15 ostomies per year, more than half (252, 50.7%) consider the incidence of PSH 30% or below, and 107 (22%) use PM. The most common reason for not using mesh was concern about mesh-related complications (141, 41.5%). When asked about type of mesh, most surgeons (153/245, 62.4%) preferred permanent mesh and an open retromuscular approach (97/278, 34.9%).

CONCLUSION

Results of the present survey show ongoing ambiguity regarding the use of PM for PSH prevention. Education to increase awareness about the incidence of PSH and well-designed safety and effectiveness studies of preventive strategies are needed to help surgeons optimize PSH prevention strategies.

Efficacy of Mindfulness-Based Cognitive Training in Surgery: Additional Analysis of the Mindful Surgeon Pilot Randomized Clinical Trial

IMPORTANCE

Mindfulness meditation training has been shown to be feasible in surgical trainees, but affective, cognitive, and performance benefits seen in other high-stress populations have yet to be evaluated.

OBJECTIVE

To explore potential benefits to stress, cognition, and performance in postgraduate year 1 (PGY-1) surgery residents receiving modified mindfulness-based stress reduction (modMBSR).

DESIGN, SETTING, AND PARTICIPANTS

This follow-up study is an analysis of the Mindful Surgeon pilot randomized clinical trial of modMBSR (n = 12) vs an active control (n = 9), evaluated at baseline (T1), postintervention (T2), and 1 year (T3), took place at an academic medical center residency training program among PGY-1 surgery residents. Data were collected between June 2016 and June 2017 and analyzed from June 2017 to December 2017.

INTERVENTIONS

Weekly 2-hour modMBSR classes and 20 minutes of daily home practice during an 8-week period vs an active control (different content, same structure).

MAIN OUTCOMES AND MEASURES

Preliminary evidence of efficacy was explored, primarily focusing on perceived stress and executive function and secondarily on burnout, depression, motor skill performance, and changes in blood oxygen level-dependent functional neuroimaging during an emotion regulation task. Group mean scores were calculated at T1, T2, and T3 and in linear mixed-effects multivariate analysis. Effect size for analysis of covariance is presented as partial η2 with the following cutoff points: small, less than 0.06; medium, 0.06 to 0.14; large, greater than 0.14.

RESULTS

Postgraduate year 1 surgery residents (N = 21; 8 [38%] women) were randomized to a modMBSR arm (n = 12) or an active control arm (n = 9). Linear mixed-effects modeling revealed differences at T2 and T3 in perceived stress (mean [SD] difference at T2: modMBSR, 1.42 [5.74]; control, 3.44 [6.71]; η2 = 0.07; mean [SD] difference at T3: modMBSR, 1.00 [4.18]; control, 1.33 [4.69]; η2 = 0.09) and in mindfulness (mean [SD] difference at T2: modMBSR, 3.08 [3.63]; control, 1.56 [4.28]; η2 = 0.13; mean [SD] difference at T3: modMBSR, 2.17 [3.66]; control, -0.11 [6.19]; η2 = 0.15). Burnout at T2 (mean [SD] difference: modMBSR, 4.50 [9.08]; control, 3.44 [6.71]; η2 = 0.01) and T3 (mean [SD] difference: modMBSR, 5.50 [9.96]; control, 5.56 [9.69]; η2 = 0.01) showed similar increase in both groups. Working memory increased more at T2 in the modMBSR arm (mean [SD] difference, 0.35 [0.60]) than in the control arm (mean [SD] difference, 0.21 [0.74]; η2 = 0.02) and at T3 (modMBSR, 0.68 [0.69]; control, 0.26 [0.58]; η2 = 0.20). Cognitive control decreased more in the control arm at T2 (mean [SD] difference at T2: modMBSR, 0.15 [0.40]; control, -0.07 [0.32]; η2 = 0.13) and at T3 (mean [SD] difference: modMBSR, 0.07 [0.59]; control, -0.26 [0.53]; η2 = 0.16). Mean (SD) circle-cutting time improved more at T2 in the modMBSR arm (-24.08 [63.00] seconds) than in the control arm (-4.22 [112.94] seconds; η2 = 0.23) and at T3 in the modMBSR arm (-4.83 [77.94] seconds) than in the control arm (11.67 [145.17] seconds; η2 = 0.13). Blood oxygen level-dependent functional neuroimaging during an emotional regulation task showed unique postintervention activity in the modMBSR arm in areas associated with executive function control (dorsolateral prefrontal cortex) and self-awareness (precuneus).

CONCLUSIONS AND RELEVANCE

In this pilot randomized clinical trial, modMBSR in PGY-1 surgery residents showed potential benefits to well-being and executive function, suggesting a powerful role for mindfulness-based cognitive training to support resident well-being and performance, as mandated by the Accreditation Council for Graduate Medical Education.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03141190.

Hernia prevention: practice patterns and surgeons' attitudes about abdominal wall closure and the use of prophylactic mesh

PURPOSE

The penetration of hernia prevention techniques into surgical practice remains unknown.

METHODS

A survey about knowledge/attitudes on hernia prevention was sent to the members of hernia societies.

RESULTS

The 497 respondents were mostly from the US (47%) or Europe (40%). Most reported practicing, but not measuring their suture-to-wound length closure of > 4:1 (63%) and practicing but not measuring the number of stitches (58%). Reasons for not using short stitch closure were: does not apply to patient population (19%), not familiar enough with methods to correctly execute (25%), takes too long (13%), not reimbursed (4%), concerned about closure-related complications (27%), and other (22%). Regarding prophylactic mesh, respondents stated they were not familiar with literature (11%), familiar with literature but would not use (24%), familiar with literature and interested in use (45%), familiar with literature and using (15%), and other (5%).

CONCLUSIONS

There appears to be some application of hernia prevention principles related to fascial closure; however, the use of prophylactic mesh still appears to be controversial.

Feasibility of Formal Mindfulness-Based Stress-Resilience Training Among Surgery Interns: A Randomized Clinical Trial

Importance

Among surgical trainees, burnout and distress are prevalent, but mindfulness has been shown to decrease the risk of depression, suicidal ideation, burnout, and overwhelming stress. In other high-stress populations, formal mindfulness training has been shown to improve mental health, yet this approach has not been tried in surgery.

Objective

To test the feasibility and acceptability of modified Mindfulness-Based Stress Reduction (MBSR) training during surgical residency.

Design, Setting, and Participants

A pilot randomized clinical trial of modified MBSR vs an active control was conducted with 21 surgical interns in a residency training program at a tertiary academic medical center, from April 30, 2016, to December 2017.

Interventions

Weekly 2-hour, modified MBSR classes and 20 minutes of suggested daily home practice over an 8-week period.

Main Outcomes and Measures

Feasibility was assessed along 6 domains (demand, implementation, practicality, acceptability, adaptation, and integration), using focus groups, interviews, surveys, attendance, daily practice time, and subjective self-report of experience.

Results

Of the 21 residents included in the analysis, 13 were men (62%). Mean (SD [range]) age of the intervention group was 29.0 (2.4 [24-31]) years, and the mean (SD [range]) age of the control group was 27.4 (2.1 [27-33]) years. Formal stress-resilience training was feasible through cultivation of stakeholder support. Modified MBSR was acceptable as evidenced by no attrition; high attendance (12 of 96 absences [13%] in the intervention group and 11 of 72 absences [15%] in the control group); no significant difference in days per week practiced between groups; similar mean (SD) daily practice time between groups with significant differences only in week 1 (control, 28.15 [12.55] minutes; intervention, 15.47 [4.06] minutes; P = .02), week 2 (control, 23.89 [12.93] minutes; intervention, 12.61 [6.06] minutes; P = .03), and week 4 (control, 26.26 [13.12] minutes; intervention, 15.36 [6.13] minutes; P = .04); course satisfaction (based on interviews and focus group feedback); and posttraining-perceived credibility (control, 18.00 [4.24]; intervention, 20.00 [6.55]; P = .03). Mindfulness skills were integrated into personal and professional settings and the independent practice of mindfulness skills continued over 12 months of follow-up (mean days [SD] per week formal practice, 3 [1.0]).

Conclusions and Relevance

Formal MBSR training is feasible and acceptable to surgical interns at a tertiary academic center. Interns found the concepts and skills useful both personally and professionally and participation had no detrimental effect on their surgical training or patient care.

Trial Registration

ClinicalTrials.gov identifier: NCT03141190.

A Coupled Magnetoelastic Strain Sensor Array for Guiding and Monitoring Hernia Repairs

OBJECTIVE

Ventral hernia repairs using mesh prosthetics suffer from high recurrence rates, with 10%-20% of repairs failing within three years. Uneven distribution of stress within the implanted mesh prosthetic is thought to contribute to the high recurrence rate. We propose a method for providing quantitative guidance and monitoring of hernia repairs using an array of magnetoelastic strain sensors.

METHODS

The magnetoelastic strain sensors presented here are based on a coupled design to achieve measurements with higher signal-to-noise ratio (SNR). A first magnetoelastic element (the transducer) is bonded to the mesh prosthetic and is characterized by a strain-dependent magnetic field. The resonance frequency of a second magnetoelastic element (the resonator) encased in a rigid casing is biased by the transducer element's magneticity and can be measured noninvasively using an external interrogation coil. The coupled magnetoelastic strain sensors are assembled using a combination of photochemical machining, patterning, and heat sealing.

RESULTS

The dynamic range of the coupled sensors can be tuned by altering the transducer geometry. Additional spring elements are integrated onto the transducer element to achieve high dynamic range measurements saturating at 74 millistrains.

CONCLUSION

A coupled magnetoelastic strain sensor combines a transducer with an encased resonator element to measure strain with high SNR on an implantable flexible hernia mesh substrate.

SIGNIFICANCE

This study provides surgeons and researchers with a clinically relevant tool to quantify the strain distributions within implanted mesh prosthetics, with the ultimate goal of reducing the recurrence rate of ventral hernia repairs.

Secondary peritonitis: principles of diagnosis and intervention

Secondary peritonitis accounts for 1% of urgent or emergent hospital admissions and is the second leading cause of sepsis in patients in intensive care units globally. Overall mortality is 6%, but mortality rises to 35% in patients who develop severe sepsis. Despite the dramatic growth in the availability and use of imaging and laboratory tests, the rapid diagnosis and early management of peritonitis remains a challenge for physicians in emergency medicine, surgery, and critical care. In this article, we review the pathophysiology of peritonitis and its potential progression to sepsis, discuss the utility and limitations of the physical examination and laboratory and radiographic tests, and present a paradigm for the management of secondary peritonitis.

Integrating coupled magnetoelastic sensors onto a flexible hernia mesh for high dynamic range strain measurements

Despite better performance over primary repairs, tension-free ventral hernia repairs with mesh still suffer from a high recurrence rate. High stress gradients in the mesh are thought to contribute to hernia recurrence. We propose a postoperative monitoring system based on a coupled pair of magnetoelastic strain sensors to enable patients and physicians to non-invasively measure and track the strain distribution across the hernia mesh. Our design combines an encased resonator with a spring-loaded transducer to achieve high signal amplitude with a wide dynamic range. We also demonstrate a fabrication protocol to integrate the resonant strain sensors with a commercial polypropylene mesh. The packaged sensor is capable of detecting up to 37.5 millistrain, an order of magnitude greater than previously demonstrated.

Lipoprotein-bound LPS induces cytokine tolerance in hepatocytes

Bacterial endotoxin (LPS) elicits dramatic responses in the host including elevated plasma lipid levels due to the increased synthesis and secretion of triglyceride (TG)-rich lipoproteins by the liver. We postulate that this cytokine-induced hyperlipoproteinemia, clinically termed the `lipemia of sepsis', represents an innate, non-adaptive host immune response to infection. Data in support of this hypothesis include the capacity of TG-rich lipoproteins (VLDL and chylomicrons, CM) to bind and neutralize LPS. Herein, we present evidence that CM-bound LPS attenuates the hepatocellular response to pro-inflammatory cytokines. Primary rodent hepatocytes pretreated with CM—LPS complexes for 2 h demonstrated a near 70% reduction in cytokine-induced NO production as compared to non-pretreated control cells ( P ≥ 0.04). Whereas hepatocytes were maximally tolerant to cytokine stimulation 6 h after CM—LPS pretreatment, the cells spontaneously regained cytokine responsiveness within 40 h. The induction of cytokine tolerance in hepatocytes follows the internalization of CM—LPS complexes and is a process regulated by the LDL receptor. CM—LPS complexes failed to induce cytokine tolerance in hepatocytes wherein lipoprotein receptor activity was inhibited with high dose receptor associated protein (30 μg/ml). Similarly, CM-bound LPS did not induce tolerance in hepatocytes from ldlr—/— mice. Thus, the biochemical or genetic inhibition of LDL receptor activity effectively prevented the CM-mediated induction of the cytokine tolerant phenotype. In conclusion, the lipemia of sepsis likely represents a mechanism by which the host combats sporadic, non-life-threatening episodes of endotoxemia. Also, it may indicate a negative regulatory mechanism for the hepatic response to sepsis, serving to effectively down-regulate the acute phase response. A better understanding of how TG-rich lipoproteins modulate the host response to LPS could yield novel biological insights with important clinical implications, including the development of lipid-based therapies for bacterial infections.

Review: The lipemia of sepsis: triglyceride-rich lipoproteins as agents of innate immunity

Bacterial endotoxin (LPS) elicits dramatic responses in the host including elevated plasma lipid levels due to the increased synthesis and secretion of triglyceride (TG)-rich lipoproteins by the liver, and the inhibition of lipoprotein lipase. This cytokine-induced hyperlipoproteinemia, clinically termed the `lipemia of sepsis', was customarily thought to represent the mobilization of lipid stores to fuel the host response to infection. However, since lipoproteins can also bind and neutralize LPS, we hypothesize that TG-rich lipoproteins (VLDL and chylomicrons) are also components of an innate, non-adaptive host immune response to infection. Herein we review data demonstrating the capacity of lipoproteins to bind LPS, protect against LPS-induced toxicity, and modulate the overall host response to this bacterial toxin. Lastly, we propose a pathway whereby lipoprotein-bound LPS may represent a novel, endogenous mechanism for regulating the hepatic acute phase response.

Preoperative FOLFIRINOX for borderline resectable pancreatic cancer: Is radiation necessary in the modern era of chemotherapy?

BACKGROUND

No consensus exists regarding the optimal neoadjuvant treatment paradigm for patients with borderline resectable pancreatic cancer (BRPC), including the respective roles of chemotherapy and radiation.

METHODS

We performed a retrospective analysis, including detailed pathologic and radiologic review, of pancreatic cancer patients undergoing FOLFIRINOX, with or without radiation therapy (RT), prior to surgical resection at a high-volume academic center over a 4-year period.

RESULTS

Of 26 patients meeting inclusion criteria, 22 (84.6%) received FOLFIRINOX alone without RT (median number of treatment cycles = 9). The majority of patients met formal radiographic criteria for BRPC, with the superior mesenteric vein representing the most common vessel involved. R0 resection rate was 90.9%, with 12 patients (54.5%) requiring vascular reconstruction. Treatment response was classified as moderate or marked in 16 patients (72.7%) according to the College of American Pathologists grading system. Estimated median disease-free and overall survival rates are 22.6 months and not reached (NR), respectively.

CONCLUSIONS

This is one of the largest series to describe the use of neoadjuvant FOLFIRINOX, without radiation therapy, in patients with BRPC undergoing surgical resection. Given the high R0 resection rates and favorable clinical outcomes with chemotherapy alone, this strategy should be further assessed in prospective study design. J. Surg. Oncol. 2016;114:587-596. © 2016 Wiley Periodicals, Inc.

Cholecystectomy After Endoscopic Sphincterotomy for Common Bile Duct Stones: Is Surgery Necessary?

It has been more than 30 years since the introduction of endoscopic sphincterotomy for the management of choledocholithiasis. Once introduced, this endoscopic intervention subsequently enabled clinicians to witness the natural history of leaving the gallbladder in situ once the common duct calculi were removed. Because many people were free of symptoms once the common bile duct was cleared of stones, patients and physicians alike soon questioned whether it was necessary to remove the gallbladder at all. Despite more than two decades of clinical research and numerous published reports, the answer to this question remains elusive. Similarly, the management algorithm for choledocholithiasis in patients with an intact gallbladder remains controversial. We review the available key data regarding this question. Importantly, there are only three prospective, randomized trials that have examined the need for cholecystectomy after endoscopic sphincterotomy, with case studies constituting most of the published reports. Consequently, the literature on this topic remains inconclusive, weakened by its retrospective approach, considerable variability between the patients studied, inconsistent inclusion and exclusion criteria, and frequently poor patient follow-up. Nonetheless, the preponderance of data favor removing the gallbladder after endoscopically clearing the common bile duct of gallstones because an estimated 25% of patients will experience recurrent symptoms within a 2-year follow up period. Recognizing the existence of various mitigating clinical factors, we advocate adopting a selective wait-and-see approach for high-risk patients, especially those with a life expectancy of less than 2 years or severely debilitating comorbidities.

Is neoadjuvant chemoradiation important in borderline resectable pancreatic cancer (BRPC)? Clinical and surgical outcomes associated with preoperative FOLFIRINOX alone in BRPC

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Background: Neoadjuvant therapy is recommended to increase the likelihood of margin-negative (R0) resection for BRPC. However, there is no consensus regarding the optimal treatment paradigm, including the respective roles of chemotherapy and radiation (RT), in this setting. Methods: Retrospective analysis was conducted of BRPC pts treated with neoadjuvant FOLFIRINOX followed by surgical resection at a single tertiary care referral center over a 4-year period. Data collected included baseline pt characteristics, toxicity profiles, radiographic and serum CA19-9 response, perioperative complication rate, R0 resection rate, histopathologic response, and frequency and patterns of recurrence. Results: 26 BRPC pts received neoadjuvant FOLFIRINOX, 22 w/o addn RT. Abutment of the SMV (n = 9, 40.9%), SMA (n = 4, 18.2%), CHA (n = 4, 18.2%), and narrowing of the SMV (n = 4, 18.2%) were the most common vascular involvement. 9 (40.9%) pts had both arterial and venous involvement. Median baseline CA19-9 level was 278.5 U/ml. Pts received a median of 9 treatment cycles (range, 4-12). Radiographic response was categorized as shrinkage (n = 11, 50%), stable (n = 9, 40.9%), or progression (n = 2, 9.1%). The Whipple procedure was the most common operation performed (n = 17, 77.3%), with 12 pts (54.5%) requiring vascular reconstruction. Clavien-Dindo complication rates of grade 0, I, II, and IIIa occurred in 25.9%, 11.1%, 44.4%, and 14.8% of pts, respectively. R0 resection rate was 90.9%, with 13 (59.1%) having negative lymph nodes. Treatment response of Evans grade III or IV, corresponding to < 10% residual tumor cells, was seen in 8 pts (36.4%), including one pathologic CR (4.5%). AJCC Stage: ypT3N0 (36.4%), ypT3N1 (18.2%), ypT1N1 (18.2%). With a median f/u time of 22.1 months, 8 pts (36.4%) have progressed, inc 7 (87.5%) with distant disease. Median PFS is 22.5 mos. Conclusions: This is one of the largest series to report on the use of neoadjuvant chemotherapy w/o RT in BRPC pts. FOLFIRINOX alone in this setting is associated with high R0 resection rates and favorable clinical outcomes, and should be further assessed in prospective study design for BRPC.

Towards a full-field strain sensor for guiding hernia repairs

Each year, approximately 400,000 ventral hernia repairs are performed in the United States [1], [2]. Large ventral hernias (hernias that occur in the abdominal wall) are typically treated by suturing in a surgical mesh to cover and overlap the hernia defect. However, in 10-20% of patients, the hernia repair fails, resulting in recurrence of the hernia, along with other complications including infection and intestinal obstruction [3], [4]. One potential cause of hernia recurrence is the unequal distribution of stress across the mesh resulting in high stress concentrations at the tissue-mesh interface, particularly at the site of mesh fixation to the abdominal wall muscles[5], [6]. Strain across the mesh can be used as an indicator for how evenly stress is distributed across the surface of the mesh. To this end, we have built a full-field, 3D strain measurement system to enable physicians to actively identify and address areas of high strain during the surgery, thus decreasing the rate of hernia recurrence. The strain sensor uses an optical technique, called the grid method, in conjunction with the defocused particle image velocimetry (DPIV) technique to measure the 3D strain distribution across the mesh. The system can achieve a limit of detection down to 0.4% strain and across a 50 cm range z-axis displacement using a Canon EOS 7D camera with a pinhole aperture mask.

Memory regulatory T cells reside in human skin

Regulatory T cells (Tregs), which are characterized by expression of the transcription factor Foxp3, are a dynamic and heterogeneous population of cells that control immune responses and prevent autoimmunity. We recently identified a subset of Tregs in murine skin with properties typical of memory cells and defined this population as memory Tregs (mTregs). Due to the importance of these cells in regulating tissue inflammation in mice, we analyzed this cell population in humans and found that almost all Tregs in normal skin had an activated memory phenotype. Compared with mTregs in peripheral blood, cutaneous mTregs had unique cell surface marker expression and cytokine production. In normal human skin, mTregs preferentially localized to hair follicles and were more abundant in skin with high hair density. Sequence comparison of TCRs from conventional memory T helper cells and mTregs isolated from skin revealed little homology between the two cell populations, suggesting that they recognize different antigens. Under steady-state conditions, mTregs were nonmigratory and relatively unresponsive; however, in inflamed skin from psoriasis patients, mTregs expanded, were highly proliferative, and produced low levels of IL-17. Taken together, these results identify a subset of Tregs that stably resides in human skin and suggest that these cells are qualitatively defective in inflammatory skin disease.

Clinical outcomes of biologic mesh: where do we stand?

After review and evaluation of current clinical data, including significant wound complications, a noteworthy failure rate at 1 year, and high product costs, it is difficult to support the continued use of biologic meshes in incisional hernia repair outside of well-designed and rigorously conducted clinical trials. An industry-sponsored, publicly available registry of biologic prosthetic use for ventral hernia repairs is needed. This straightforward mandate, if properly constructed and implemented, would significantly expand knowledge regarding how these intriguing biomaterials are used and their overall clinical efficacy, thus yielding a more robust basis for the continued use of biologic prosthetics in hernia repair than is currently available.

A critical review of biologic mesh use in ventral hernia repairs under contaminated conditions

PURPOSE

We used an evidence-based approach to determine whether the promotions and claims of superiority of biologic mesh over synthetic mesh use in ventral hernia repairs (VHRs) under contaminated conditions were sound and valid.

METHODS

We searched the Medline database to specifically identify review articles relating to biologic mesh and VHR and critically reviewed these studies using an evidence-based approach.

RESULTS

For the past 45 years, four clinical reviews and one systematic review have included biologic meshes as part of a larger discussion on available prosthetics for VHR. All reviews supported biologic mesh use, especially in the setting of contaminated fields. Yet, the primary literature included in these reviews and served as the basis for these conclusions consisted entirely of case series and case reports, which have the lowest level of evidence in determining scientific validity. Furthermore, the FDA has neither cleared nor approved this particular use.

CONCLUSIONS

The cumulative data regarding biologic mesh use in VHRs under contaminated conditions does not support the claim that it is better than synthetic mesh used under the same conditions. The highly promoted and at least moderately utilized practice of placing biologic mesh in contamination is being done outside of the original intended use, and a re-evaluation of or possible moratorium on biologic mesh use in hernia surgery is seriously warranted. Alternatively, an industry-sponsored national registry of patients in whom ventral hernia repairs involved biologic mesh would substantively add to our understanding regarding how these intriguing biomaterials are being used and their overall clinical efficacy.

Heparin protects against septic mortality via apoE-antagonism

BACKGROUND

Apolipoprotein E (apoE), a component of plasma lipoproteins, increases septic mortality in a rodent model of sepsis, presumably by enhancing lipid antigen presentation to antigen-presenting cells via the low-density lipoprotein receptor (LDLR). Downstream, this culminates in natural killer T (NKT) cell activation and cytokine secretion. To determine whether apoE antagonism would protect against septic mortality in mice, apoE-LDLR binding was antagonized using heparin, which can inhibit apoE's LDLR-binding site.

METHODS

C57BL/6 mice underwent cecal ligation and puncture (CLP) and heparin infusion. Serum partial thromboplastin time and alanine aminotransferase were measured at 24 hours, and survival was monitored for 7 days after CLP. LDLR+/+ and LDLR-/- fibroblasts were incubated with apoE and heparin to measure apoE internalization. Hepatic NKT cells and cytokine levels were quantified via fluorescence-activated cell sorting.

RESULTS

Heparin decreased CLP-induced mortality by 50% versus saline-treated controls, independent of anticoagulation. LDLR+/+ fibroblasts displayed decreased uptake of apoE when treated concurrently with heparin for 12 hours. In septic mice, hepatic alanine aminotransferase levels, hepatic NKT cells, and plasma cytokine levels decreased after heparin treatment.

CONCLUSIONS

This study demonstrates that heparin protects against septic mortality independent of its anticoagulant effect. This protective effect is associated with the inhibition of apoE-LDLR binding, diminished NKT proliferation and cytokine production, and hepatic dysfunction. These findings indicate a potential clinical role for apoE antagonism in the treatment of sepsis.

NKT cells: the culprits of sepsis?

Sepsis is currently a leading cause of death in hospital intensive care units. Previous studies suggest that the pathophysiology of sepsis involves the hyperactivation of complex pro-inflammatory cascades that include the activation of various immune cells and the exuberant secretion of pro-inflammatory cytokines by these cells. Natural killer T-cells (NKT) are a sub-lineage of T cells that share characteristics of conventional T cells and NK cells, and bridge innate and adaptive immunity. More recently, NKT cells have been implicated in microbial immunity, including the onset of sepsis. Moreover, apolipoprotein E (apoE), a component of triglyceride-rich lipoproteins, has been shown to be protective in endotoxemia and gram-negative infections in addition to its well-known role in lipid metabolism. Here, we will review the role of NKT cells in sepsis and septic shock, the immunoregulatory role of apoE in the host immune response to infection, and propose a mechanism for this immunoregulation.

Chylomicrons combined with endotoxin moderate microvascular permeability

Triglyceride-rich lipoprotein-bound endotoxin (CM-LPS) inhibits the host innate immune response to sepsis by attenuating the hepatocellular response to pro-inflammatory cytokine stimulation. This 'cytokine tolerance' in hepatocytes is a transient, receptor-dependent process that correlates with internalization of CM-LPS via low density lipoprotein (LDL) receptors. Since endothelial cells are integral to the immune response and similarly express LDL receptors, we hypothesized that CM-LPS could be internalized and ultimately attenuate the deleterious effects of pro-inflammatory molecules like tumor necrosis factor-α (TNF-α) and platelet activating factor (PAF) on endothelial permeability. Here, we show that CM-LPS complexes induce cytokine tolerance in endothelial cells. In rats, TNF-α increased hydraulic conductivity 2.5-fold over baseline and PAF increased it 5-fold; but, pretreatment with CM-LPS or an attenuated analog (CM-LPS*) inhibited these changes. Nuclear/cytoplasmic levels of p65 were reduced after TNF-α-stimulation in endothelial cell monolayers pretreated with CM-LPS, a finding consistent with inhibition of nuclear factor (NF)-κB translocation. Also consistent with inhibition was stabilized intercellular adhesion, as illustrated with antibody to VE-cadherin using confocal microscopy. These results provide additional support for the integral role of lipoproteins in the innate immune response to infection and lend further credence to developing lipid-based therapy for Gram-negative sepsis.

An expanding role for apolipoprotein E in sepsis and inflammation

BACKGROUND

Apolipoprotein E (apoE), a component of plasma lipoproteins, plays an important, but poorly defined role in sepsis. We have shown that injecting apoE increases septic mortality in a rat model of gram-negative bacterial sepsis, with concomitant hepatic natural killer T (NKT) cell proliferation and activation. The presumed mechanism for this apoE-mediated mortality is that apoE can bind and traffic antigens, presumed to include lipopolysaccharide (LPS), and promote activation of dendritic cells (DC) with subsequent NKT activation and cytokine release. Thus, we sought to prove that LPS was the antigen responsible for the increased NKT activation enhanced by the presence of apoE.

METHODS

We isolated murine marrow-derived DCs, pulsed them with lipid antigen (LPS, and positive controls alpha-galactosylceramide [alpha-GalCer] and isoglobotrihexosylceramide 3 [iGb3]) with or without apoE, and then cocultured the DCs with hybridoma NKTs. NKT activation was measured by interleukin-2 (IL-2) supernatant levels using enzyme-linked immunosorbent assay (ELISA).

RESULTS

LPS at different concentrations was a weak stimulus for NKT activation regardless of apoE presence. When apoE was present, iGb3, an endogenous ligand analog, elicited more than a 2-fold increase in IL-2 response when compared with iGb3 alone (P < .05).

CONCLUSIONS

These results indicate an endogenous ligand, not LPS, may be responsible for NKT activation. A molecular remnant similar to iGb3 could act as a damage-associated molecular pattern and play a prominent role in animal models of sepsis.

Prospective randomized trial of LC+LCBDE vs ERCP/S+LC for common bile duct stone disease

OBJECTIVE

To compare outcome parameters for good-risk patients with classic signs, symptoms, and laboratory and abdominal imaging features of cholecystolithiasis and choledocholithiasis randomized to either laparoscopic cholecystectomy plus laparoscopic common bile duct exploration (LC+LCBDE) or endoscopic retrograde cholangiopancreatography sphincterotomy plus laparoscopic cholecystectomy (ERCP/S+LC).

DESIGN

Our study was a prospective trial conducted following written informed consent, with randomization by the serially numbered, opaque envelope technique.

SETTING

Our institution is an academic teaching hospital and the central receiving and trauma center for the City and County of San Francisco, California.

PATIENTS

We randomized 122 patients (American Society of Anesthesiologists grade 1 or 2) meeting entry criteria. Ten of these patients, excluded from outcome analysis, were protocol violators having signed out of the hospital against medical advice before 1 or both procedures were completed.

INTERVENTIONS

Treatment was preoperative ERCP/S followed by LC, or LC+LCBDE.

MAIN OUTCOME MEASURES

The primary outcome measure was efficacy of stone clearance from the common bile duct. Secondary end points were length of hospital stay, cost of index hospitalization, professional fees, hospital charges, morbidity and mortality, and patient acceptance and quality of life scores.

RESULTS

The baseline characteristics of the 2 randomized groups were similar. Efficacy of stone clearance was likewise equivalent for both groups. The time from first procedure to discharge was significantly shorter for LC+LCBDE (mean [SD], 55 [45] hours vs 98 [83] hours; P < .001). Hospital service and total charges for index hospitalization were likewise lower for LC+LCBDE, but the differences were not statistically significant. The professional fee charges for LC+LCBDE were significantly lower than those for ERCP/S+LC (median [SD], $4820 [1637] vs $6139 [1583]; P < .001). Patient acceptance and quality of life scores were equivalent for both groups.

CONCLUSIONS

Both ERCP/S+LC and LC+LCBDE were highly effective in detecting and removing common bile duct stones and were equivalent in overall cost and patient acceptance. However, the overall duration of hospitalization was shorter and physician fees lower for LC+LCBDE.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00807729.

Predicting strangulated small bowel obstruction: an old problem revisited

BACKGROUND

Diagnosing intestinal strangulation complicating a small bowel obstruction (SBO) remains a considerable challenge. Despite decades of experience and numerous studies, no clinical indicators have been identified that reliably predict this life-threatening condition. Our goal was to determine which clinical indicators in patients with SBO can be used to independently predict the presence of strangulated intestine.

METHODS

Medical records were reviewed for 192 adult patients operated on for acute SBO over an 11-year period (1996-2006). Seventy-two preoperative clinical, laboratory, and radiologic findings at admission were examined. Data from patients with strangulated intestine were compared to data from patients without bowel compromise. Likelihood ratios were generated for each significant parameter in a multivariate logistic regression analysis.

RESULTS

Forty-four patients had bowel strangulation requiring bowel resection, and 148 had no strangulation. The most significant independent predictor of bowel strangulation was the computed tomography (CT) finding of reduced wall enhancement, with a sensitivity and specificity of 56% and 94% [likelihood ratio (LR) 9.3]. Elevated white blood cell (WBC) count and guarding were moderately predictive (LR 1.7 and 2.8).

CONCLUSION

Regression analysis of multiple preoperative criteria demonstrates that reduced wall enhancement on CT, peritoneal signs, and elevated WBC are the only variables independently predictive of bowel strangulation in patients with SBO.

Apolipoprotein E-mediated immune regulation in sepsis

Lipids and lipoproteins have emerged as key constituents of the immune response to microbial infection. We, therefore, sought to understand the complex interaction between lipoprotein metabolism and sepsis. Apolipoprotein E (apoE), a component of plasma lipoproteins, has been suggested to bind and traffic Ags for NKT cell activation. However, apoE's role in sepsis has not been demonstrated. In this study, we examined the effect of exogenous apoE in a rat model of septic peritonitis, induced by cecal ligation and puncture. We demonstrate that 48 h after serial injections of apoE, septic mortality increased in a dose-dependent manner. While sepsis resulted in increased splenic and decreased hepatic and circulating NKT cell populations, serial injections of apoE for 24 h after cecal ligation and puncture increased the frequency, cell number, and BrdU uptake in splenic and hepatic NKT cell populations, while concomitantly depleting these populations in the circulation. These changes were correlated with elevated alanine amino transferase levels, an indicator of liver injury. Interestingly, while sepsis increased hepatic T cell apoptosis and necrosis, apoE reversed these changes. apoE also promoted increases in predominantly Th1 cytokine levels in sera and a decrease in IL-4, the main NKT cell-derived Th2 cytokine. Consequently, apoE treatment is associated with increased sepsis-induced mortality, and increased NKT cell frequency and proliferation in the liver and spleen, with concomitant decreases in these NKT cell parameters in the peripheral circulation. apoE treatment also promoted a Th1 cytokine response, increased the degree of liver injury, and decreased apoptosis in hepatic lymphocytes.