Surgery Clerkship Directors' Perceptions of the COVID-19 Pandemic's Impact on Medical Student Education

BACKGROUND

This study assessed the national impact of the coronavirus disease 2019 (COVID-19) pandemic on the education of medical students assigned to surgery clerkship rotations, as reported by surgery clerkship directors (CDs).

STUDY DESIGN

In the spring of 2020 and 2021, the authors surveyed 164 CDs from 144 Liaison Committee on Medical Education-accredited US medical schools about their views of the pandemic's impact on the surgery clerkship curriculum, students' experiences, outcomes, and institutional responses.

RESULTS

Overall survey response rates, calculated as number of respondents/number of surveyed, were 44.5% (73 of 164) and 50.6% (83 of 164) for the spring 2020 and 2021 surveys, respectively. Nearly all CDs (more than 95%) pivoted to virtual platforms and solutions. Most returned to some form of in-person learning by winter 2020, and prepandemic status by spring 2021 (46%, 38 of 83). Students' progression to the next year was delayed by 12% (9 of 73), and preparation was negatively impacted by 45% (37 of 83). Despite these data, CDs perceived students' interest in surgical careers was not significantly affected (89% vs 77.0%, p = 0.09). During the 1-year study, the proportion of CDs reporting a severe negative impact on the curriculum dropped significantly (p < 0.0001) for most parameters assessed except summative evaluations (40.3% vs 45.7%, p = 0.53). CDs (n = 83) also noted the pandemic's positive impact with respect to virtual patient encounters (21.7%), didactics (16.9%), student test performance (16.9%), continuous personal learning (14.5%), engagement in the clerkship (9.6%), and student interest in surgery as a career (7.2%).

CONCLUSIONS

During the pandemic, the severe negative impact on student educational programs lessened, and novel virtual curricular solutions emerged. Student interest in surgery as a career was sustained. Measures of student competency and effectiveness of new curriculum, including telehealth, remain areas for future investigation.

Transforming the Future of Surgeon-Scientists

OBJECTIVE

To create a blueprint for surgical department leaders, academic institutions, and funding agencies to optimally support surgeon-scientists.

BACKGROUND

Scientific contributions by surgeons have been transformative across many medical disciplines. Surgeon-scientists provide a distinct approach and mindset toward key scientific questions. However, lack of institutional support, pressure for increased clinical productivity, and growing administrative burden are major challenges for the surgeon-scientist, as is the time-consuming nature of surgical training and practice.

METHODS

An American Surgical Association Research Sustainability Task Force was created to outline a blueprint for sustainable science in surgery. Leaders from top NIH-sponsored departments of surgery engaged in video and in-person meetings between January and April 2023. A strength, weakness, opportunities, threats analysis was performed, and workgroups focused on the roles of surgeons, the department and institutions, and funding agencies.

RESULTS

Taskforce recommendations: (1) SURGEONS: Growth mindset : identifying research focus, long-term planning, patience/tenacity, team science, collaborations with disparate experts; Skill set : align skills and research, fill critical skill gaps, develop team leadership skills; DEPARTMENT OF SURGERY (DOS): (2) MENTORSHIP: Chair : mentor-mentee matching/regular meetings/accountability, review of junior faculty progress, mentorship training requirement, recognition of mentorship (eg, relative value unit equivalent, awards; Mentor: dedicated time, relevant scientific expertise, extramural funding, experience and/or trained as mentor, trusted advisor; Mentee : enthusiastic/eager, proactive, open to feedback, clear about goals; (3) FINANCIAL SUSTAINABILITY: diversification of research portfolio, identification of matching funding sources, departmental resource awards (eg, T-/P-grants), leveraging of institutional resources, negotiation of formalized/formulaic funds flow investment from academic medical center toward science, philanthropy; (4) STRUCTURAL/STRATEGIC SUPPORT: Structural: grants administrative support, biostats/bioinformatics support, clinical trial and research support, regulatory support, shared departmental laboratory space/equipment; Strategic: hiring diverse surgeon-scientist/scientists faculty across DOS, strategic faculty retention/ recruitment, philanthropy, career development support, progress tracking, grant writing support, DOS-wide research meetings, regular DOS strategic research planning; (5) COMMUNITY AND CULTURE: Community: right mix of faculty, connection surgeon with broad scientific community; Culture: building research infrastructure, financial support for research, projecting importance of research (awards, grand rounds, shoutouts); (6) THE ROLE OF INSTITUTIONS: Foundation: research space co-location, flexible start-up packages, courses/mock study section, awards, diverse institutional mentorship teams; Nurture: institutional infrastructure, funding (eg, endowed chairs), promotion friendly toward surgeon-scientists, surgeon-scientists in institutional leadership positions; Expectations: RVU target relief, salary gap funding, competitive starting salaries, longitudinal salary strategy; (7) THE ROLE OF FUNDING AGENCIES: change surgeon research training paradigm, offer alternate awards to K-awards, increasing salary cap to reflect market reality, time extension for surgeon early-stage investigator status, surgeon representation on study section, focused award strategies for professional societies/foundations.

CONCLUSIONS

Authentic recommitment from surgeon leaders with intentional and ambitious actions from institutions, corporations, funders, and society is essential in order to reap the essential benefits of surgeon-scientists toward advancements of science.

Experience of a single academic institution with the National Accreditation Program for Rectal Cancer and the resulting improvement in care

AIM

The American College of Surgeons Committee on Cancer developed the National Accreditation Program for Rectal Cancer (NAPRC) to reduce variations in rectal cancer care, standardize clinical practice and encourage multidisciplinary approaches. The aim of this study was to analyse if accreditation achieved a higher quality of care at one hospital.

METHOD

The University of California Davis Medical Center was accredited in 2019. A retrospective review of rectal adenocarcinoma patients was performed between the years 2013 and 2018. Patients presenting from 2013 to 2015 were discussed at a gastrointestinal tumour board while patients in 2018 had an accredited rectal cancer tumour board. Patients from 2016 to 2017 were excluded as the programme was still developing. Compliance to the NAPRC standards was compared between the cohorts.

RESULTS

One hundred and thirty patients were evaluated, 88 (68%) in the prerectal tumour board cohort and 42 (32%) in the rectal tumour board cohort. The prerectal tumour board cohort often failed to meet attendance standards. All patients in the rectal tumour board cohort met all criteria. Similarly, clinical service compliance improved in the rectal tumour board cohort for 13 metrics, 10 of which were statistically significant. Although a high proportion of patients in both groups experienced quality surgery, i.e. complete total mesorectal excision and negative margins, the lack of complete pathological reporting in the prerectal tumour board cohort limited analysis.

CONCLUSION

Multidisciplinary rectal cancer tumour boards are associated with improved compliance with recommended care by the NAPRC. Patients discussed at a rectal cancer tumour board were more likely to receive appropriate staging, coordinated care and have better clinical documentation.

Recovering fetal signals transabdominally through interferometric near-infrared spectroscopy (iNIRS)

Noninvasive transabdominal fetal pulse oximetry can provide clinicians critical assessment of fetal health and potentially contribute to improved management of childbirth. Conventional pulse oximetry through continuous wave (CW) light has challenges measuring the signals from deep tissue and separating the weak fetal signal from the strong maternal signal. Here, we propose a new approach for transabdominal fetal pulse oximetry through interferometric near-infrared spectroscopy (iNIRS). This approach provides pathlengths of photons traversing the tissue, which facilitates the extraction of fetal signals by rejecting the very strong maternal signal from superficial layers. We use a multimode fiber combined with a mode-field converter at the detection arm to boost the signal of iNIRS. Together, we can detect signals from deep tissue (>∼1.6 cm in sheep abdomen and in human forearm) at merely 1.1 cm distance from the source. Using a pregnant sheep model, we experimentally measured and extracted the fetal heartbeat signals originating from deep tissue. This validated a key step towards transabdominal fetal pulse oximetry through iNIRS and set a foundation for further development of this method to measure the fetal oxygen saturation.

Surgical Education

This paper summarizes the proceedings of the joint European Surgical Association ESA/American Surgical Association symposium on Surgical Education that took place in Bordeaux, France, as part of the celebrations for 30 years of ESA scientific meetings. Three presentations on the use of quantitative metrics to understand technical decisions, coaching during training and beyond, and entrustable professional activities were presented by American Surgical Association members and discussed by ESA members in a symposium attended by members of both associations.

A bio-instructive parylene-based conformal coating suppresses thrombosis and intimal hyperplasia of implantable vascular devices

Implantable vascular devices are widely used in clinical treatments for various vascular diseases. However, current approved clinical implantable vascular devices generally have high failure rates primarily due to their surface lacking inherent functional endothelium. Here, inspired by the pathological mechanisms of vascular device failure and physiological functions of native endothelium, we developed a new generation of bioactive parylene (poly(p-xylylene))-based conformal coating to address these challenges of the vascular devices. This coating used a polyethylene glycol (PEG) linker to introduce an endothelial progenitor cell (EPC) specific binding ligand LXW7 (cGRGDdvc) onto the vascular devices for preventing platelet adhesion and selectively capturing endogenous EPCs. Also, we confirmed the long-term stability and function of this coating in human serum. Using two vascular disease-related large animal models, a porcine carotid artery interposition model and a porcine carotid artery-jugular vein arteriovenous graft model, we demonstrated that this coating enabled rapid generation of self-renewable "living" endothelium on the blood contacting surface of the expanded polytetrafluoroethylene (ePTFE) grafts after implantation. We expect this easy-to-apply conformal coating will present a promising avenue to engineer surface properties of "off-the-shelf" implantable vascular devices for long-lasting performance in the clinical settings.

Evolution and Variations of the Ovine Model of Spina Bifida

Spina bifida is the most common congenital anomaly of the central nervous system and the first non-fatal fetal lesions to be addressed by fetal intervention. While research in spina bifida has been performed in rodent, nonhuman primate, and canine models, sheep have been a model organism for the disease. This review summarizes the history of development of the ovine model of spina bifida, previous applications, and translation into clinical studies. Initially used by Meuli et al. [Nat Med. 1995;1(4):342-7], fetal myelomeningocele defect creation and in utero repair demonstrated motor function preservation. The addition of myelotomy in this model can reproduce hindbrain herniation malformations, which is the leading cause of mortality and morbidity in humans. Since inception, the ovine models have been validated numerous times as the ideal large animal model for fetal repair, with both locomotive scoring and spina bifida defect scoring adding to the rigor of this model. The ovine model has been used to study different methods of myelomeningocele defect repair, the application of various tissue engineering techniques for neuroprotection and bowel and bladder function. The results of these large animal studies have been translated into human clinical trials including Management of Meningocele Study (MOMS) trial that established current standard of care for prenatal repair of spina bifida defects, and the ongoing trials including the Cellular Therapy for In Utero Repair of Myelomeningocele (CuRe) trial using a stem cell patch for repair. The advancement of these life savings and life-altering therapies began in sheep models, and this notable model continues to be used to further the field including current work with stem cell therapy.

Engineered multi-functional, pro-angiogenic collagen-based scaffolds loaded with endothelial cells promote large deep burn wound healing

The lack of vascularization associated with deep burns delays the construction of wound beds, increases the risks of infection, and leads to the formation of hypertrophic scars or disfigurement. To address this challenge, we have fabricated a multi-functional pro-angiogenic molecule by grafting integrin αvβ3 ligand LXW7 and collagen-binding peptide (SILY) to a dermatan sulfate (DS) glycosaminoglycan backbone, named LXW7-DS-SILY (LDS), and further employed this to functionalize collagen-based Integra scaffolds. Using a large deep burn wound model in C57/BLK6 mice (8-10 weeks old, 26-32g, n = 39), we demonstrated that LDS-modified collagen-based Integra scaffolds loaded with endothelial cells (ECs) accelerate wound healing rate, re-epithelialization, vascularization, and collagen deposition. Specifically, a 2 cm × 3 cm full-thickness skin burn wound was created 48 h after the burn, and then wounds were treated with four groups of different dressing scaffolds, including Integra + ECs, Integra + LDS, and Integra + LDS + ECs with Integra-only as the control. Digital photos were taken for wound healing measurement on post-treatment days 1, 7, 14, 21, 28, and 35. Post-treatment photos revealed that treatment with the Intgera + LDS + ECs scaffold exhibited a higher wound healing rate in the proliferation phase. Histology results showed significantly increased re-epithelialization, increased collagen deposition, increased thin and mixed collagen fiber content, increased angiogenesis, and shorter wound length within the Integra + LDS + ECs group at Day 35. On Day 14, the Integra + LDS + ECs group showed the same trend. The relative proportions of collagen changed from Day 14 to Day 35 in the Integra + LDS + ECs and Integra + ECs groups demonstrated decreased thick collagen fiber deposition and greater thin and mixed collagen fiber deposition. LDS-modified Integra scaffolds represent a promising novel treatment to accelerate deep burn wound healing, thereby potentially reducing the morbidity associated with open burn wounds. These scaffolds can also potentially reduce the need for autografting and morbidity in patients with already limited areas of harvestable skin.

Does the American College of Surgeons New Level I Children's Surgery Center Verification Affect Treatment Efficiency and Narcotic Administration in Treating Pediatric Trauma Patients with Femur Fracture?

BACKGROUND

In 2015, the American College of Surgeons (ACS) created a new hospital improvement program to enhance the performance of pediatric care in US hospitals. The Children's Surgery Verification (CSV) Quality Improvement Program is predicated on the idea that pediatric surgical patients have improved outcomes when treated at children's hospitals with optimal resources. Achieving ACS level I CSV designation at pediatric trauma centers may lead to greater benefits for pediatric trauma patients; however, the specific benefits have yet to be identified. We hypothesize that achieving the additional designation of ACS level I CSV is associated with decreased narcotic use perioperatively and improved efficiency when managing pediatric patients with femur fractures.

STUDY DESIGN

This study is a retrospective analysis of traumatic pediatric orthopaedic femur fractures treated at a verified level I pediatric trauma center before and after CSV designation (2010 to 2014 vs 2015 to 2019). Efficiency parameters, defined as time from admission to surgery, duration of surgery, and duration of hospital stay, and narcotic administration in oral morphine equivalents (OMEs) were compared.

RESULTS

Of 185 traumatic femur fractures analyzed, 80 occurred before meeting ACS level I CSV criteria, and 105 occurred after. Post-CSV, there was a significant decrease in mean wait time from admission to surgery (16.64 hours pre-CSV, 12.52 hours post-CSV [p < 0.01]) and duration of hospital stay (103.49 hours pre-CSV, 71.61 hours post-CSV [p < 0.01]). Narcotic usage was significantly decreased in both the preoperative period (40.61 OMEs pre-CSV, 23.77 OMEs post-CSV [p < 0.01]) and postoperative period (126.67 OMEs pre-CSV, 45.72 OMEs post-CSV [p < 0.01]).

CONCLUSIONS

Achieving ACS level I CSV designation is associated with increased efficiency and decreased preoperative and postoperative narcotic use when treating pediatric trauma patients.

Gender Disparity in Pediatric Surgery: An Evaluation of Pediatric Surgery Conference Participation

BACKGROUND

Leadership in academic conferences is an important factor for academic advancement. Underrepresentation of women in academic surgical conferences has been demonstrated in other subspecialties, but it has not been well-studied in pediatric surgery.

METHODS

This retrospective descriptive study analyzes conference participation at 2 national pediatric surgery annual conference programs from 2003 to 2022. Moderator, speakers, and research presenter sex was collected. The primary outcome was the proportion of female participants in each of these roles. Mann-Kendall trend test was conducted to assess for significance.

RESULTS

Across 29 meetings, a total of 523 sessions were examined. Overall, female participation in all roles increased from 2003 to 2022. There were statistically positive trends of female participation in leadership roles as moderator (p = 0.003) and speaker (p = 0.01), with moderator role demonstrating the largest proportional female increase over time - with a 7-fold increase from 7.1% in 2003 to 50.0% in 2022. There was also a significant increasing trend in female participation as research presenters (p < 0.01) from 25.4% to 46.4%.

CONCLUSION

Gender representation in pediatric surgery conferences has improved over the last two decades. Women now represent approximately half of all participatory roles, and efforts to continue providing equal opportunities for women at pediatric surgery academic conferences should continue.

LEVEL OF EVIDENCE

N/A.

TYPE OF STUDY

Retrospective Descriptive.

In utero delivery of mRNA to the heart, diaphragm and muscle with lipid nanoparticles

Nanoparticle-based drug delivery systems have the potential to revolutionize medicine, but their low vascular permeability and rapid clearance by phagocytic cells have limited their medical impact. Nanoparticles delivered at the in utero stage can overcome these key limitations due to the high rate of angiogenesis and cell division in fetal tissue and the under-developed immune system. However, very little is known about nanoparticle drug delivery at the fetal stage of development. In this report, using Ai9 CRE reporter mice, we demonstrate that lipid nanoparticle (LNP) mRNA complexes can deliver mRNA in utero, and can access and transfect major organs, such as the heart, the liver, kidneys, lungs and the gastrointestinal tract with remarkable efficiency and low toxicity. In addition, at 4 weeks after birth, we demonstrate that 50.99 ± 5.05%, 36.62 ± 3.42% and 23.7 ± 3.21% of myofiber in the diaphragm, heart and skeletal muscle, respectively, were transfected. Finally, we show here that Cas9 mRNA and sgRNA complexed to LNPs were able to edit the fetal organs in utero. These experiments demonstrate the possibility of non-viral delivery of mRNA to organs outside of the liver in utero, which provides a promising strategy for treating a wide variety of devastating diseases before birth.

A bioactive material with dual integrin-targeting ligands regulates specific endogenous cell adhesion and promotes vascularized bone regeneration in adult and fetal bone defects

Significant progress has been made in designing bone materials capable of directing endogenous cells to promote vascularized bone regeneration. However, current strategies lack regulation of the specific endogenous cell populations for vascularized bone regeneration, thus leading to adverse tissue formation and decreased regenerative efficiency. Here, we engineered a biomaterial to regulate endogenous cell adhesion and promote vascularized bone regeneration. The biomaterial works by presenting two synthetic ligands, LLP2A and LXW7, explicitly targeting integrins α4β1 and αvβ3, respectively, expressed on the surfaces of the cells related to bone formation and vascularization, such as mesenchymal stem cells (MSCs), osteoblasts, endothelial progenitor cells (EPCs), and endothelial cells (ECs). In vitro, the LLP2A/LXW7 modified biomaterial improved the adhesion of MSCs, osteoblasts, EPCs, and ECs via integrin α4β1 and αvβ3, respectively. In an adult rat calvarial bone defect model, the LLP2A/LXW7 modified biomaterial enhanced bone formation and vascularization by synergistically regulating endogenous cells with osteogenic and angiogenic potentials, such as DLX5⁺ cells, osteocalcin⁺ cells, CD34⁺/CD45^- cells and CD31⁺ cells. In a fetal sheep spinal bone defect model, the LLP2A/LXW7 modified biomaterial augmented bone formation and vascularization without any adverse effects. This innovative biomaterial offers an off-the-shelf, easy-to-use, and biologically safe product suitable for vascularized bone regeneration in both fetal and adult disease environments.

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Two integrin-binding ligands for constructing vascularized bone biomaterial.

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Extracellular matrix (ECM)-mimicking collagen-based biomaterial with specific integrin binding sites for cell adhesion.

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Biomaterial regulates adhesion of endogenous stem cells with osteogenic and angiogenic potentials.

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Biomaterial promotes vascularized bone formation in adult and fetal bone defects without safety issues.

•

An easy-to-make and off-the-shelf biomaterial for treatment of clinical bone diseases.

Evaluation of a biodegradable polyurethane patch for repair of diaphragmatic hernia in a rat model: A pilot study

INTRODUCTION

Congenital diaphragmatic hernia (CDH) repair is an area of active research. Large defects requiring patches have a hernia recurrence rate of up to 50%. We designed a biodegradable polyurethane (PU)-based elastic patch that matches the mechanical properties of native diaphragm muscle. We compared the PU patch to a non-biodegradable Gore-Tex™ (polytetrafluoroethylene) patch.

METHODS

The biodegradable polyurethane was synthesized from polycaprolactone, hexadiisocyanate and putrescine, and then processed into fibrous PU patches by electrospinning. Rats underwent 4 mm diaphragmatic hernia (DH) creation via laparotomy followed by immediate repair with Gore-Tex™ (n = 6) or PU (n = 6) patches. Six rats underwent sham laparotomy without DH creation/repair. Diaphragm function was evaluated by fluoroscopy at 1 and 4 weeks. At 4 weeks, animals underwent gross inspection for recurrence and histologic evaluation for inflammatory reaction to the patch materials.

RESULTS

There were no hernia recurrences in either cohort. Gore-Tex™ had limited diaphragm rise compared to sham at 4 weeks (1.3 mm vs 2.9 mm, p = 0.003), but no difference was found between PU and sham (1.7 mm vs 2.9 mm, p = 0.09). There were no differences between PU and Gore-Tex™ at any time point. Both patches formed an inflammatory capsule, with similar thicknesses between cohorts on the abdominal (Gore-Tex™ 0.07 mm vs. PU 0.13 mm, p = 0.39) and thoracic (Gore-Tex™ 0.3 mm vs. PU 0.6 mm, p = 0.09) sides.

CONCLUSION

The biodegradable PU patch allowed for similar diaphragmatic excursion compared to control animals. There were similar inflammatory responses to both patches. Further work is needed to evaluate long-term functional outcomes and further optimize the properties of the novel PU patch in vitro and in vivo.

LEVEL OF EVIDENCE

Level II, Prospective Comparative Study.

Development and Characterization of Bioinspired Lipid Raft Nanovesicles for Therapeutic Applications

Lipid rafts are highly ordered regions of the plasma membrane enriched in signaling proteins and lipids. Their biological potential is realized in exosomes, a subclass of extracellular vesicles (EVs) that originate from the lipid raft domains. Previous studies have shown that EVs derived from human placental mesenchymal stromal cells (PMSCs) possess strong neuroprotective and angiogenic properties. However, clinical translation of EVs is challenged by very low, impure, and heterogeneous yields. Therefore, in this study, lipid rafts are validated as a functional biomaterial that can recapitulate the exosomal membrane and then be synthesized into biomimetic nanovesicles. Lipidomic and proteomic analyses show that lipid raft isolates retain functional lipids and proteins comparable to PMSC-EV membranes. PMSC-derived lipid raft nanovesicles (LRNVs) are then synthesized at high yields using a facile, extrusion-based methodology. Evaluation of biological properties reveals that LRNVs can promote neurogenesis and angiogenesis through modulation of lipid raft-dependent signaling pathways. A proof-of-concept methodology further shows that LRNVs could be loaded with proteins or other bioactive cargo for greater disease-specific functionalities, thus presenting a novel type of biomimetic nanovesicles that can be leveraged as targeted therapeutics for regenerative medicine.

Engineered extracellular vesicles with high collagen-binding affinity present superior in situ retention and therapeutic efficacy in tissue repair

Although stem cell-derived extracellular vesicles (EVs) have remarkable therapeutic potential for various diseases, the therapeutic efficacy of EVs is limited due to their degradation and rapid diffusion after administration, hindering their translational applications. Here, we developed a new generation of collagen-binding EVs, by chemically conjugating a collagen-binding peptide SILY to EVs (SILY-EVs), which were designed to bind to collagen in the extracellular matrix (ECM) and form an EV-ECM complex to improve EVs' in situ retention and therapeutic efficacy after transplantation. Methods: SILY was conjugated to the surface of mesenchymal stem/stromal cell (MSC)-derived EVs by using click chemistry to construct SILY-EVs. Nanoparticle tracking analysis (NTA), ExoView analysis, cryogenic electron microscopy (cryo-EM) and western-blot analysis were used to characterize the SILY-EVs. Fluorescence imaging (FLI), MTS assay, ELISA and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to evaluate the collagen binding and biological functions of SILY-EVs in vitro. In a mouse hind limb ischemia model, the in vivo imaging system (IVIS), laser doppler perfusion imaging (LDPI), micro-CT, FLI and RT-qPCR were used to determine the SILY-EV retention, inflammatory response, blood perfusion, gene expression, and tissue regeneration. Results:In vitro, the SILY conjugation significantly enhanced EV adhesion to the collagen surface and did not alter the EVs' biological functions. In the mouse hind limb ischemia model, SILY-EVs presented longer in situ retention, suppressed inflammatory responses, and significantly augmented muscle regeneration and vascularization, compared to the unmodified EVs. Conclusion: With the broad distribution of collagen in various tissues and organs, SILY-EVs hold promise to improve the therapeutic efficacy of EV-mediated treatment in a wide range of diseases and disorders. Moreover, SILY-EVs possess the potential to functionalize collagen-based biomaterials and deliver therapeutic agents for regenerative medicine applications.

The hidden mortality of pediatric firearm violence

INTRODUCTION

Firearms and motor vehicle collisions (MVC) are leading causes of mortality in children. We hypothesized that firearm injuries would have a higher mortality than MVCs in children and a higher level of resource utilization METHODS: Trauma patients <18 years old at a Level 1 pediatric trauma center sustaining gunshot wounds (GSW) or MVCs 2009-2019 were included. The primary outcome was mortality. The secondary outcome was immediate surgery. The California Department of Public Health's Overall Injury Surveillance tool was queried for patients <18 with GSW or MVC 2006-2015 to compare statewide case fatality rates (CFRs), and analyze proportions of GSWs by intent: assault, self-inflicted, and unintentional.

RESULTS

Of 13,840 pediatric trauma patients at our institution, 295 GSWs (2.1%) and 4467 MVCs (32.3%) were included. Mortality was higher for GSWs (7.5% vs. 0.8%, p<0.0001). GSW patients were more likely to require immediate surgery (34.4% vs. 11.2%, p<0.0001). On multivariable analysis, GSW patients were 7.8-times more likely to die than MVC patients (OR 7.83, 95% CI 3.68-16.66, p<0.0001), adjusted for age, sex, and injury severity. Statewide, there were 10,790 pediatric GSWs with 1586 deaths (CFR 14.7%) vs. 710 deaths in 261,363 children in MVCs (CFR 0.3%, p<0.0001). The GSW CFR rose (13.4% to 16.5%, p = 0.05) while the MVC CFR decreased (0.5% to 0.2%, p<0.0001) in 2015 vs. 2006.

CONCLUSION

Firearm violence in pediatric patients is significantly more lethal than MVCs and is resource intensive. The case fatality rate for pediatric firearm violence is rising. Resources must be directed at preventing pediatric firearm injuries.

LEVEL OF EVIDENCE

Prognosis study, Level II.

Impact of Gestational Age on Neuroprotective Function of Placenta-Derived Mesenchymal Stromal Cells

INTRODUCTION

The Management of Myelomeningocele Study demonstrated that in utero repair of myelomeningocele improved motor outcomes compared with postnatal repair. However, even after in utero repair, many children were still unable to walk. We have previously demonstrated that augmentation of in utero repair with early-gestation placental mesenchymal stromal cells (PMSCs) improves motor outcomes in lambs compared with standard in utero repair. The neuroprotective potential of PMSCs of all gestational ages has not been evaluated previously.

METHODS

PMSCs were isolated from discarded first trimester (n = 3), second trimester (n = 3), and term (n = 3) placentas by explant culture. Cytokine array analysis was performed. Secretion of two neurotrophic factors, brain-derived neurotrophic factor and hepatocyte growth factor, was evaluated by enzyme-linked immunosorbent assay. An in vitro neuroprotective assay demonstrated to be associated with in vivo function was performed.

RESULTS

All cell lines secreted immunomodulatory and neuroprotective cytokines and secreted the neurotrophic factors evaluated. Increased neuroprotective capabilities relative to no PMSCs were demonstrated in two of the three first trimester cell lines (5.61, 4.96-6.85, P < 0.0001 and 2.67, 1.67-4.12, P = 0.0046), two of the three second trimester cell lines (2.82, 2.45-3.43, P = 0.0004 and 3.25, 2.62-3.93, P < 0.0001), and two of the three term cell lines (2.72, 2.32-2.92, P = 0.0033 and 2.57, 1.41-4.42, P = 0.0055).

CONCLUSIONS

We demonstrated variation in neuroprotective function between cell lines and found that some cell lines from each trimester had neuroprotective properties. This potentially expands the donor pool of PMSCs for clinical use. Further in-depth studies are needed to understand potential subtle differences in cell function at different gestational ages.

Early investigations into improving bowel and bladder function in fetal ovine myelomeningocele repair

INTRODUCTION

Fetal myelomeningocele (MMC) repair improves lower extremity motor function. We have previously demonstrated that augmentation of fetal MMC repair with placental mesenchymal stromal cells (PMSCs) seeded on extracellular matrix (PMSC-ECM) further improves motor function in the ovine model. However, little progress has been made in improving bowel and bladder function, with many patients suffering from neurogenic bowel and bladder. We hypothesized that fetal MMC repair with PMSC-ECM would also improve bowel and bladder function.

METHODS

MMC defects were surgically created in twelve ovine fetuses at median gestational age (GA) 73 days, followed by defect repair at GA101 with PMSC-ECM. Fetuses were delivered at GA141. Primary bladder function outcomes were voiding posture and void volumes. Primary bowel function outcome was anorectal manometry findings including resting anal pressure and presence of rectoanal inhibitory reflex (RAIR). Secondary outcomes were anorectal and bladder detrusor muscle thickness. PMSC-ECM lambs were compared to normal lambs (n = 3).

RESULTS

Eighty percent of PMSC-ECM lambs displayed normal voiding posture compared to 100% of normal lambs (p = 1). Void volumes were similar (PMSC-ECM 6.1 ml/kg vs. normal 8.8 ml/kg, p = 0.4). Resting mean anal pressures were similar between cohorts (27.0 mmHg PMSC-ECM vs. normal 23.5 mmHg, p = 0.57). RAIR was present in 3/5 PMSC-ECM lambs that underwent anorectal manometry and all normal lambs (p = 0.46). Thicknesses of anal sphincter complex, rectal wall muscles, and bladder detrusor muscles were similar between cohorts.

CONCLUSION

Ovine fetal MMC repair augmented with PMSC-ECM results in near-normal bowel and bladder function. Further work is needed to evaluate these outcomes in human patients.

Efficacy of clinical-grade human placental mesenchymal stromal cells in fetal ovine myelomeningocele repair

BACKGROUND

While fetal repair of myelomeningocele (MMC) revolutionized management, many children are still unable to walk independently. Preclinical studies demonstrated that research-grade placental mesenchymal stromal cells (PMSCs) prevent paralysis in fetal ovine MMC, however this had not been replicated with clinical-grade cells that could be used in an upcoming human clinical trial. We tested clinical-grade PMSCs seeded on an extracellular matrix (PMSC-ECM) in the gold standard fetal ovine model of MMC.

METHODS

Thirty-five ovine fetuses underwent MMC defect creation at a median of 76 days gestational age, and defect repair at 101 days gestational age with application of clinical-grade PMSC-ECM (3 × 10⁵ cells/cm², n = 12 fetuses), research-grade PMSC-ECM (3 × 10⁵ cells/cm², three cell lines with n = 6 (Group 1), n = 6 (Group 2), and n = 3 (Group 3) fetuses, respectively) or ECM without PMSCs (n = 8 fetuses). Three normal lambs underwent no surgical interventions. The primary outcome was motor function measured by the Sheep Locomotor Rating scale (SLR, range 0: complete paralysis to 15: normal ambulation) at 24 h of life. Correlation of lumbar spine large neuron density with SLR was evaluated.

RESULTS

Clinical-grade PMSC-ECM lambs had significantly better motor function than ECM-only lambs (SLR 14.5 vs. 6.5, p = 0.04) and were similar to normal lambs (14.5 vs. 15, p = 0.2) and research-grade PMSC-ECM lambs (Group 1: 14.5 vs. 15, p = 0.63; Group 2: 14.5 vs. 14.5, p = 0.86; Group 3: 14.5 vs. 15, p = 0.50). Lumbar spine large neuron density was strongly correlated with motor function (r = 0.753, p<0.001).

CONCLUSIONS

Clinical-grade placental mesenchymal stromal cells seeded on an extracellular matrix rescued ambulation in a fetal ovine myelomeningocele model. Lumbar spine large neuron density correlated with motor function, suggesting a neuroprotective effect of the PMSC-ECM in prevention of paralysis. A first-in-human clinical trial of PMSCs in human fetal myelomeningocele repair is underway.

Bioactive extracellular matrix scaffolds engineered with proangiogenic proteoglycan mimetics and loaded with endothelial progenitor cells promote neovascularization and diabetic wound healing

Diabetic ischemic wound treatment remains a critical clinical challenge. Neovascularization plays a significant role in wound healing during all stages of the tissue repair process. Strategies that enhance angiogenesis and neovascularization and improve ischemic pathology may promote the healing of poor wounds, particularly diabetic wounds in highly ischemic conditions. We previously identified a cyclic peptide LXW7 that specifically binds to integrin αvβ3 on endothelial progenitor cells (EPCs) and endothelial cells (ECs), activates vascular endothelial growth factor (VEGF) receptors, and promotes EC growth and maturation. In this study, we designed and synthesized a multi-functional pro-angiogenic molecule by grafting LXW7 and collagen-binding peptides (SILY) to a dermatan sulfate (DS) glycosaminoglycan backbone, named LXW7-DS-SILY, and further employed this multi-functional molecule to functionalize collagen-based extracellular matrix (ECM) scaffolds. We confirmed that LXW7-DS-SILY modification significantly promoted EPC attachment and growth on the ECM scaffolds in vitro and supported EPC survival in vivo in the ischemic environment. When applied in an established Zucker Diabetic Fatty (ZDF) rat ischemic skin flap model, LXW7-DS-SILY-functionalized ECM scaffolds loaded with EPCs significantly improved wound healing, enhanced neovascularization and modulated collagen fibrillogenesis in the ischemic environment. Altogether, this study provides a promising novel treatment to accelerate diabetic ischemic wound healing, thereby reducing limb amputation and mortality of diabetic patients.

Long-term safety evaluation of placental mesenchymal stromal cells for in utero repair of myelomeningocele in a novel ovine model

PURPOSE

Augmentation of in utero myelomeningocele repair with human placental mesenchymal stromal cells seeded onto extracellular matrix (PMSC-ECM) improves motor outcomes in an ovine myelomeningocele model. This study evaluated the safety of PMSC-ECM application directly onto the fetal spinal cord in preparation for a clinical trial.

METHODS

Laminectomy of L5-L6 with PMSC-ECM placement directly onto the spinal cord was performed in five fetal lambs at gestational age (GA) 100-106 days. Lambs and ewes were monitored for three months following delivery. Lambs underwent magnetic resonance imaging (MRI) of the brain and spine at birth and at three months. All organs from lambs and uteri from ewes underwent histologic evaluation. Lamb spinal cords and brains and ewe placentas were evaluated for persistence of PMSCs by polymerase chain reaction for presence of human DNA.

RESULTS

MRIs demonstrated no evidence of abnormal tissue growth or spinal cord tethering. Histological analysis demonstrated no evidence of abnormal tissue growth or treatment related adverse effects. No human DNA was identified in evaluated tissues.

CONCLUSION

There was no evidence of abnormal tissue growth or PMSC persistence at three months following in utero application of PMSC-ECM to the spinal cord. This supports proceeding with clinical trials of PMSC-ECM for in utero myelomeningocele repair.

LEVEL OF EVIDENCE

N/A TYPE OF STUDY: Basic science.

National surgical, obstetric, anaesthesia and nursing plan, Nigeria

Recent evidence suggests that strengthening surgical care within existing health systems will strengthen the overall health-care system. However, Nigeria's national strategic health development plan 2018-2022 placed little emphasis on surgical care. To address the gap, we worked with professional societies and other partners to develop the national surgical, obstetric, anaesthesia and nursing plan 2019-2023. The aim was to foster actions to prioritize surgical care for the achievement of universal health coverage. In addition to creating a costed strategy to strengthen surgical care, the plan included children's surgery and nursing: two key aspects that have been neglected in other national surgical plans. Pilot implementation of the plan began in 2020, supported by a nongovernmental organization with experience in surgical care in the region. We have created specific entry points to facilitate the pilot implementation. In the pilot, an electronic surgery registry has been created; personnel are being trained in life support; nurses are being trained in safe perioperative care; biomedical technicians and sterile supplies nurses are being trained in surgical instrument repair and maintenance; and research capacity is being strengthened. In addition, the mainstream media are being mobilized to improve awareness about the plan among policy-makers and the general population. Another development partner is interested in providing support for paediatric surgery, and a children's hospital is being planned. As funding is a key challenge to full implementation, we need innovative domestic funding strategies to support and sustain implementation.

Placental Mesenchymal Stromal Cells: Preclinical Safety Evaluation for Fetal Myelomeningocele Repair

BACKGROUND

Myelomeningocele (MMC) is the congenital failure of neural tube closure in utero, for which the standard of care is prenatal surgical repair. We developed clinical-grade placental mesenchymal stromal cells seeded on a dural extracellular matrix (PMSC-ECM), which have been shown to improve motor outcomes in preclinical ovine models. To evaluate the long-term safety of this product prior to use in a clinical trial, we conducted safety testing in a murine model.

METHODS

Clinical grade PMSCs obtained from donor human placentas were seeded onto a 6 mm diameter ECM at a density of 3 × 105 cells/cm2. Immunodeficient mice were randomized to receive either an ECM only or PMSC-ECM administered into a subcutaneous pocket. Mice were monitored for tumor formation until two study endpoints: 4 wk and 6 mo. Pathology and histology on all tissues was performed to evaluate for tumors. Quantitative polymerase chain reaction (qPCR) was performed to evaluate for the presence of human DNA, which would indicate persistence of PMSCs.

RESULTS

Fifty-four mice were included; 13 received ECM only and 14 received PMSC-ECM in both the 4-wk and 6-mo groups. No mice had gross or microscopic evidence of tumor development. A nodular focus of mature fibrous connective tissue was identified at the subcutaneous implantation pocket in the majority of mice with no significant difference between ECM only and PMSC-ECM groups (P = 0.32 at 4 wk, P > 0.99 at 6 mo). Additionally, no human DNA was detected by qPCR in any mice at either time point.

CONCLUSIONS

Subcutaneous implantation of the PMSC-ECM product did not result in tumor formation and we found no evidence that PMSCs persisted. These results support the safety of the PMSC-ECM product for use in a Phase 1/2a human clinical trial evaluating fetal MMC repair augmented with PMSC-ECM.

Towards Noninvasive Accurate Detection of Intrapartum Fetal Hypoxic Distress

Current intrapartum fetal well-being assessment is performed using electronic fetal monitoring (EFM), technically referred to as cardiotocography (CTG), which transabdominally monitors fetal heart rate (FHR) in relationship to maternal uterine contractions. Sometimes the deceleration in FHR following a uterine contraction can be sign of fetal hypoxic distress, but it may also be a normal physiological response. Multiple studies have shown that EFM has a high false positive rate for detecting fetal hypoxia. This has caused a rise in emergency Cesarean section (C-section) deliveries performed in the US over the years, while the rates of various conditions associated with anoxic brain injury at birth remain unchanged. The underlying problem is that many factors other than hypoxia can cause non-reassuring CTG traces and a more objective measure of oxygen supply to the fetal brain is not conveniently available. We are working to develop a transabdominal fetal pulse oximetry (TFO) system to non-invasively measure fetal arterial blood oxygen saturation (FSpO2) in order to enhance intrapartum fetal monitoring. This paper gives an overview of the past and ongoing work performed to develop TFO, highlights the main engineering and clinical challenges faced and presents preliminary results that demonstrate feasibility of TFO in both pregnant sheep models and human subjects.

A Novel Model of Fetal Spinal Cord Exposure Allowing for Long-Term Postnatal Survival

BACKGROUND

The inherent morbidity associated with fetal ovine models of myelomeningocele (MMC) has created challenges for long-term survival of lambs. We aimed to develop a fetal ovine surgical spinal exposure model which could be used to evaluate long-term safety after direct spinal cord application of novel therapeutics for augmentation of in utero MMC repair.

METHODS

At gestational age (GA) 100-106, fetal lambs underwent surgical intervention. Laminectomy of L5-L6 was performed, dura was removed, and an experimental product was directly applied to the spinal cord. Paraspinal muscles and skin were closed and the fetus was returned to the uterus. Lambs were delivered via cesarean section at GA 140-142. Lambs were survived for 3 months with regular evaluation of motor function by the sheep locomotor rating scale. Spinal angulation was evaluated by magnetic resonance imaging at 2 weeks and 3 months.

RESULTS

Five fetal surgical intervention lambs and 6 control lambs who did not undergo surgical intervention were included. All lambs survived to the study endpoint of 3 months. No lambs had motor function abnormalities or increased spinal angulation.

CONCLUSION

This model allows for long-term survival after fetal spinal cord exposure with product application directly onto the spinal cord.

Impact of the COVID-19 pandemic on surgical trainee education and well-being spring 2020-winter 2020: A path forward

Background

The time course and longitudinal impact of the COVID -19 pandemic on surgical education(SE) and learner well-being (LWB)is unknown.

Material and methods

Check-in surveys were distributed to Surgery Program Directors and Department Chairs, including general surgery and surgical specialties, in the summer and winter of 2020 and compared to a survey from spring 2020. Statistical associations for items with self-reported ACGME Stage and the survey period were assessed using categorical analysis.

Results

Stage 3 institutions were reported in spring (30%), summer (4%) [p < 0.0001] and increased in the winter (18%). Severe disruption (SD) was stage dependent (Stage 3; 45% (83/184) vs. Stages 1 and 2; 26% (206/801)[p < 0.0001]). This lessened in the winter (23%) vs. spring (32%) p = 0.02. LWB severe disruption was similar in spring 27%, summer 22%, winter 25% and was associated with Stage 3.

Conclusions

Steps taken during the pandemic reduced SD but did not improve LWB. Systemic efforts are needed to protect learners and combat isolation pervasive in a pandemic.

Impact of prescription drug monitoring program mandate on postoperative opioid prescriptions in children

PURPOSE

Prescription drug monitoring programs (PDMPs) have been established to combat the opioid epidemic, but there is no data on their efficacy in children. We hypothesized that a statewide PDMP mandate would be associated with fewer opioid prescriptions in pediatric surgical patients.

METHODS

Patients < 18 undergoing inguinal hernia repair, orchiopexy, orchiectomy, appendectomy, or cholecystectomy at a tertiary children's hospital were included. The primary outcome, discharge opioid prescription, was compared for 10 months pre-PDMP (n = 158) to 10 months post-PDMP (n = 228). Interrupted time series analysis was performed to determine the effect of the PDMP on opioid prescribing.

RESULTS

Over the 20-month study period, there was an overall decrease in the rate of opioid prescriptions per month (- 3.6% change, p < 0.001). On interrupted time series analysis, PDMP implementation was not associated with a significant decrease in the monthly rate of opioid prescriptions (1.27% change post-PDMP, p = 0.4). However, PDMP implementation was associated with a reduction in opioid prescriptions of greater than 5 days' supply (- 2.7% per month, p = 0.03).

CONCLUSION

Opioid prescriptions declined in pediatric surgical patients over the study time period. State-wide PDMP implementation was associated with a reduction in postoperative opioid prescriptions of more than 5 days' duration.

Fetal myelomeningocele repair: a narrative review of the history, current controversies and future directions

Fetal surgery is a relatively new field of medicine. The purpose of this narrative review is to present the history of how fetal surgery became the standard of care for myelomeningocele (MMC), the current controversies of this treatment, and active areas of research that may change how MMC is treated. Fetal surgery for MMC emerged out of the University of California, San Francisco in the 1980s in the laboratory of Dr. Michael Harrison. Initial research focused on testing the hypothesis that the in utero repair of MMC could improve outcomes in the ovine model. Evidence from this model suggested that in utero repair decreases the secondary damage to the exposed neural tissue and improves post-natal neurologic outcomes, opening the door for human intervention. This was followed by the Management of Myelomeningocele Study (MOMS), which was a multicenter randomized controlled trial comparing the prenatal versus postnatal MMC repair. The MOMS trial was stopped early due to the improved outcomes of the prenatal repair, establishing the open fetal MMC repair as the standard of care. Since the MOMS trial, two primary areas of controversy have arisen: the operative approach and criteria for the repair. The three operative approaches include open, endoscopic and a hybrid approach combining open and endoscopic. Several of the inclusion and exclusion criteria from the MOMS trial have been challenged, to include body mass index, gestational diabetes, other fetal abnormalities, maternal infections and Rh alloimmunization. New areas of research have also emerged, exploring cell based therapies to improve fetal outcomes, alternatives to fetal surgery and alternatives to primary skin closure of the fetus.

A Survey of the Surgical Morbidity and Mortality Conference in the United States and Canada: A Dying Tradition or the Key to Modern Quality Improvement?

OBJECTIVE

We seek to identify the current role and practices of the surgery morbidity and mortality (M&M) conference in academic surgery departments in the United States and Canada.

DESIGN, SETTING, AND PARTICIPANTS

All members of the Society of Surgical Chairs, a program of the American College of Surgeons, were e-mailed an IRB-approved 28-question electronic survey in fall 2017. Up to 3 reminders were sent.

RESULTS

Responses from 129/186 (69%) departments of surgery were received. Nearly all departments (96%) continue to have a departmental M&M conference. The M&M conference is typically weekly (93%), between 7 and 9 AM (80%), on weekdays during which there are no scheduled elective operations (84%). Attendance is mandatory for residents (98%), but required for faculty in only 49% of departments. Fewer than half of all departments (44%) have written guidelines as to which complications should be reported to M&M. Most conferences are prepared case presentations (89%), but may include unprepared discussions (17%), case-based educational presentations (30%), or a combination (28%). The most common classification category was by root case of the error (60%) and preventability (58%). Most departments keep electronic and/or physical M&M reports, while 21% maintain a relational database and 25% do not retain records. While almost all (96%) departments reported participating in at least one national quality improvement program, these are not often linked to the M&M process.

CONCLUSIONS

M&M is predominantly seen as an educational conference based on a few select cases. Departmental quality is monitored with hospital-driven or national quality improvement efforts. Integration of hospital-based quality metric programs with surgery M&M conference is uncommon and represents an opportunity for hospital-department collaboration.

Causes of early mortality in pediatric trauma patients

BACKGROUND

Trauma is the leading cause of death in children, and most deaths occur within 24 hours of injury. A better understanding of the causes of death in the immediate period of hospital care is needed.

METHODS

Trauma admissions younger than 18 years from 2009 to 2019 at a Level I pediatric trauma center were reviewed for deaths (n = 7,145). Patients were stratified into ages 0-6, 7-12, and 13-17 years old. The primary outcome was cause of death, with early death defined as less than 24 hours after trauma center arrival.

RESULTS

There were 134 (2%) deaths with a median age of 7 years. The median time from arrival to death was 14.4 hours (interquartile range, 0.5-87.8 hours). Half (54%) occurred within 24 hours. However, most patients who survived initial resuscitation in the emergency department died longer than 24 hours after arrival (69%). Traumatic brain injury was the most common cause of death (66%), followed by anoxia (9.7%) and hemorrhage (8%). Deaths from hemorrhage were most often in patients sustaining gunshot wounds (73% vs. 11% of all other deaths, p < 0.0001), more likely to occur early (100% vs. 50% of all other deaths, p = 0.0009), and all died within 6 hours of arrival. Death from hemorrhage was more common in adolescents (21.4% of children aged 13-17 vs. 6.3% of children aged 0-6, and 0% of children aged 7-12 p = 0.03). The highest case fatality rates were seen in hangings (38.5%) and gunshot wounds (9.6%).

CONCLUSION

Half of pediatric trauma deaths occurred within 24 hours. Death from hemorrhage was rare, but all occurred within 6 hours of arrival. This is a critical time for interventions for bleeding control to prevent death from hemorrhage in children. Analysis of these deaths can focus efforts on the urgent need for development of new hemorrhage control adjuncts in children.

LEVEL OF EVIDENCE

Epidemiological study, level IV.

Design and In Vivo Evaluation of a Non-Invasive Transabdominal Fetal Pulse Oximeter

OBJECTIVE

Current intrapartum fetal monitoring technology is unable to provide physicians with an objective metric of fetal well-being, leading to degraded patient outcomes and increased litigation costs. Fetal oxygen saturation (SpO2) is a more suitable measure of fetal distress, but the inaccessibility of the fetus prior to birth makes this impossible to capture through current means. In this paper, we present a fully non-invasive, transabdominal fetal oximetry (TFO) system that provides in utero measures of fetal SpO2.

METHODS

TFO is performed by placing a reflectance-mode optode on the maternal abdomen and sending photons into the body to investigate the underlying fetal tissue. The proposed TFO system design consists of a multi-detector optode, an embedded optode control system, and custom user-interface software. To evaluate the developed TFO system, we utilized an in utero hypoxic fetal lamb model and performed controlled desaturation experiments while capturing gold standard arterial blood gases (SaO2).

RESULTS

Various degrees of fetal hypoxia were induced with true SaO2 values ranging between 10.5% and 66%. The non-invasive TFO system was able to accurately measure these fetal SpO2 values, supported by a root mean-squared error of 6.37% and strong measures of agreement with the gold standard.

CONCLUSION

The results support the efficacy of the presented TFO system to non-invasively measure a wide-range of fetal SpO2 values and identify critical levels of fetal hypoxia.

SIGNIFICANCE

TFO has the potential to improve fetal outcomes by providing obstetricians with a non-invasive measure of fetal oxygen saturation prior to delivery.

Impact of the COVID-19 Pandemic on Surgical Training and Learner Well-Being: Report of a Survey of General Surgery and Other Surgical Specialty Educators

BACKGROUND

The COVID-19 pandemic disrupted the delivery of surgical services. The purpose of this communication was to report the impact of the pandemic on surgical training and learner well-being and to document adaptations made by surgery departments.

STUDY DESIGN

A 37-item survey was distributed to educational leaders in general surgery and other surgical specialty training programs. It included both closed- and open-ended questions and the self-reported stages of GME during the COVID-19 pandemic, as defined by the ACGME. Statistical associations for items with stage were assessed using categorical analysis.

RESULTS

The response rate was 21% (472 of 2,196). US stage distribution (n = 447) was as follows: stage 1, 22%; stage 2, 48%; and stage 3, 30%. Impact on clinical education significantly increased by stage, with severe reductions in nonemergency operations (73% and 86% vs 98%) and emergency operations (8% and 16% vs 34%). Variable effects were reported on minimal expected case numbers across all stages. Reductions were reported in outpatient experience (83%), in-hospital experience (70%), and outside rotations (57%). Increases in ICU rotations were reported with advancing stage (7% and 13% vs 37%). Severity of impact on didactic education increased with stage (14% and 30% vs 46%). Virtual conferences were adopted by 97% across all stages. Severity of impact on learner well-being increased by stage-physical safety (6% and 9% vs 31%), physical health (0% and 7% vs 17%), and emotional health (11% and 24% vs 42%). Regardless of stage, most but not all made adaptations to support trainees' well-being.

CONCLUSIONS

The pandemic adversely impacted surgical training and the well-being of learners across all surgical specialties proportional to increasing ACGME stage. There is a need to develop education disaster plans to support technical competency and learner well-being. Careful assessment for program advancement will also be necessary. The experience during this pandemic shows that virtual learning and telemedicine will have a considerable impact on the future of surgical education.

Minimizing the risk of occupational Q fever exposure: A protocol for ensuring Coxiella burnetii-negative pregnant ewes are used for medical research

Q fever is a worldwide zoonosis caused by Coxiella burnetii that can lead to abortion, endocarditis, and death in humans. Researchers utilizing parturient domestic ruminants, including sheep, have an increased risk of occupational exposure. This study evaluated the effectiveness of our screening protocol in eliminating C. burnetii-positive sheep from our facility. From August 2010 to May 2018, all ewes (N  =  306) and select lambs (N  =  272; ovis aries) were screened twice for C. burnetii utilizing a serum Phase I and Phase II antibody immunofluorescence assay (IFA). The first screen was performed by the vendor prior to breeding, and the second screen was performed on arrival to the research facility. Ewes that were positive on arrival screening were quarantined and retested using repeat IFA serology, enzyme-linked immunosorbent assay, buffy coat polymerase chain reaction (PCR), and amniotic fluid PCR. The overall individual seroprevalence of C. burnetii in the flocks tested by the vendor was 14.2%. Ewes with negative Phase I and Phase II IFA results were selected for transport to the research facility. Upon arrival to the facility, two (0.7%) ewes had positive Phase I IFA results. Repeat testing demonstrated seropositivity in one of these two ewes, though amniotic fluid PCR was negative in both. The repeat seropositive ewe was euthanized prior to use in a research protocol. No Q fever was reported among husbandry, laboratory or veterinary staff during the study period. Serologic testing for C. burnetii with IFA prior to transport and following arrival to a research facility limits potential exposure to research staff.

Fetal Surgery in the Primate 4.0: A New Technique 30 Years Later

INTRODUCTION

Open fetal surgery requires a hemostatic hysterotomy that minimizes membrane separation. For over 30 years, the standard of care for hysterotomy in the gravid uterus has been the AutoSuture Premium Poly CS*-57 stapler.

OBJECTIVE

In this study, we sought to test the feasibility of hysterotomy in a rhesus monkey model with the Harmonic ACE®+7 Shears.

METHODS

A gravid rhesus monkey underwent midgestation hysterotomy at approximately 90 days of gestation (2nd trimester; term = 165 ± 10 days) using the Harmonic ACE®+7 Shears. A two-layer uterine closure was completed and the dam was monitored by ultrasound intermittently throughout the pregnancy. At 58 days after hysterotomy (near term), a final surgery was performed to evaluate the uterus and hysterotomy site.

RESULTS

A 3.5-cm hysterotomy was completed in 2 min 7 s. The opening was hemostatic and the membranes were sealed. Immediately after closure and throughout the pregnancy, ultrasound revealed intact membranes without separation and normal amniotic fluid levels. At term, the scar was well healed without signs of thinning or dehiscence.

CONCLUSIONS

The Harmonic ACE®+7 Shears produced a hemostatic midgestation hysterotomy with membrane sealing in the rhesus monkey model. Importantly, healing was acceptable.

In utero treatment of myelomeningocele with placental mesenchymal stromal cells - Selection of an optimal cell line in preparation for clinical trials

BACKGROUND

We determined whether in vitro potency assays inform which placental mesenchymal stromal cell (PMSC) lines produce high rates of ambulation following in utero treatment of myelomeningocele in an ovine model.

METHODS

PMSC lines were created following explant culture of three early-gestation human placentas. In vitro neuroprotection was assessed with a neuronal apoptosis model. In vivo, myelomeningocele defects were created in 28 fetuses and repaired with PMSCs at 3 × 10⁵ cells/cm² of scaffold from Line A (n = 6), Line B (n = 7) and Line C (n = 5) and compared to no PMSCs (n = 10). Ambulation was scored as ≥13 on the Sheep Locomotor Rating Scale.

RESULTS

In vitro, Line A and B had higher neuroprotective capability than no PMSCs (1.7 and 1.8 respectively vs 1, p = 0.02, ANOVA). In vivo, Line A and B had higher large neuron densities than no PMSCs (25.2 and 27.9 respectively vs 4.8, p = 0.03, ANOVA). Line C did not have higher neuroprotection or larger neuron density than no PMSCs. In vivo, Line A and B had ambulation rates of 83% and 71%, respectively, compared to 60% with Line C and 20% with no PMSCs.

CONCLUSION

The in vitro neuroprotection assay will facilitate selection of optimal PMSC lines for clinical use.

LEVEL OF EVIDENCE

n/a.

TYPE OF STUDY

Basic science.

Developing an Injectable Nanofibrous Extracellular Matrix Hydrogel With an Integrin αvβ3 Ligand to Improve Endothelial Cell Survival, Engraftment and Vascularization

Endothelial cell (EC) transplantation via injectable collagen hydrogel has received much attention as a potential treatment for various vascular diseases. However, the therapeutic effect of transplanted ECs is limited by their poor viability, which partially occurs as a result of cellular apoptosis triggered by the insufficient cell-extracellular matrix (ECM) engagement. Integrin binding to the ECM is crucial for cell anchorage to the surrounding matrix, cell spreading and migration, and further activation of intracellular signaling pathways. Although collagen contains several different types of integrin binding sites, it still lacks sufficient specific binding sites for ECs. Previously, using one-bead one-compound (OBOC) combinatorial technology, we identified LXW7, an integrin αvβ3 ligand, which possessed a strong binding affinity to and enhanced functionality of ECs. In this study, to improve the EC-matrix interaction, we developed an approach to molecularly conjugate LXW7 to the collagen backbone, via a collagen binding peptide SILY, in order to increase EC specific integrin binding sites on the collagen hydrogel. Results showed that in the in vitro 2-dimensional (2D) culture model, the LXW7-treated collagen surface significantly improved EC attachment and survival and decreased caspase 3 activity in an ischemic-mimicking environment. In the in vitro 3-dimensional (3D) culture model, LXW7-modified collagen hydrogel significantly improved EC spreading, proliferation, and survival. In a mouse subcutaneous implantation model, LXW7-modified collagen hydrogel improved the engraftment of transplanted ECs and supported ECs to form vascular network structures. Therefore, LXW7-functionalized collagen hydrogel has shown promising potential to improve vascularization in tissue regeneration and may be used as a novel tool for EC delivery and the treatment of vascular diseases.

Extracellular Matrix Mimicking Nanofibrous Scaffolds Modified With Mesenchymal Stem Cell-Derived Extracellular Vesicles for Improved Vascularization

The network structure and biological components of natural extracellular matrix (ECM) are indispensable for promoting tissue regeneration. Electrospun nanofibrous scaffolds have been widely used in regenerative medicine to provide structural support for cell growth and tissue regeneration due to their natural ECM mimicking architecture, however, they lack biological functions. Extracellular vesicles (EVs) are potent vehicles of intercellular communication due to their ability to transfer RNAs, proteins, and lipids, thereby mediating significant biological functions in different biological systems. Matrix-bound nanovesicles (MBVs) are identified as an integral and functional component of ECM bioscaffolds mediating significant regenerative functions. Therefore, to engineer EVs modified electrospun scaffolds, mimicking the structure of the natural EV-ECM complex and the physiological interactions between the ECM and EVs, will be attractive and promising in tissue regeneration. Previously, using one-bead one-compound (OBOC) combinatorial technology, we identified LLP2A, an integrin α4β1 ligand, which had a strong binding to human placenta-derived mesenchymal stem cells (PMSCs). In this study, we isolated PMSCs derived EVs (PMSC-EVs) and demonstrated they expressed integrin α4β1 and could improve endothelial cell (EC) migration and vascular sprouting in an ex vivo rat aortic ring assay. LLP2A treated culture surface significantly improved PMSC-EV attachment, and the PMSC-EV treated culture surface significantly enhanced the expression of angiogenic genes and suppressed apoptotic activity. We then developed an approach to enable "Click chemistry" to immobilize LLP2A onto the surface of electrospun scaffolds as a linker to immobilize PMSC-EVs onto the scaffold. The PMSC-EV modified electrospun scaffolds significantly promoted EC survival and angiogenic gene expression, such as KDR and TIE2, and suppressed the expression of apoptotic markers, such as caspase 9 and caspase 3. Thus, PMSC-EVs hold promising potential to functionalize biomaterial constructs and improve the vascularization and regenerative potential. The EVs modified biomaterial scaffolds can be widely used for different tissue engineering applications.

Validation of a Novel Transabdominal Fetal Oximeter in a Hypoxic Fetal Lamb Model

Current intrapartum fetal oxygen saturation (SaO2) monitoring methodologies are limited, mostly consisting of fetal heart rate monitoring which is a poor predictor of fetal hypoxia. A newly developed transabdominal fetal oximeter (TFO) may be able to determine fetal SaO2 non-invasively. This study is to validate a novel TFO in determining fetal SaO2 in a hypoxic fetal lamb model. Fetal hypoxia was induced in at-term pregnant ewe by placing an aortic occlusion balloon infrarenally and inflating it in a stepwise fashion to decrease blood flow to the uterine artery. The inflation was held at each step for 10 min, and fetal arterial blood gases (ABGs) were intermittently recorded from the fetal carotid artery. The balloon catheter was deflated when fetal SaO2 fell below 15%, and the fetus was recovered. A total of three desaturation experiments were performed. The average fetal SpO2 reported by the TFO was derived at each hypoxic level and correlated with the ABG measures. Fetal SaO2 from the ABGs ranged from 10.5 to 66%. The TFO SpO2 correlated with the ABG fetal SaO2 (r-squared = 0.856) with no significant differences (p > 0.5). The fetal SpO2 measurements from TFO were significantly different than the maternal SpO2 (p < 0.01), which suggests that the transcutaneous measurements are penetrating through the maternal abdomen sufficiently and are expressing the underlying fetal tissue physiology. The recently developed TFO system was able to non-invasively report the fetal SpO2, which showed strong correlation with ABG measures and showed no significant differences.

Learning curves of open and endoscopic fetal spina bifida closure: systematic review and meta-analysis

OBJECTIVE

The Management of Myelomeningocele Study (MOMS) trial demonstrated the safety and efficacy of open fetal surgery for spina bifida aperta (SBA). Recently developed alternative techniques may reduce maternal risks without compromising the fetal neuroprotective effects. The aim of this systematic review was to assess the learning curve (LC) of different fetal SBA closure techniques.

METHODS

MEDLINE, Web of Science, EMBASE, Scopus and Cochrane databases and the gray literature were searched to identify relevant articles on fetal surgery for SBA, without language restriction, published between January 1980 and October 2018. Identified studies were reviewed systematically and those reporting all consecutive procedures and with postnatal follow-up ≥ 12 months were selected. Studies were included only if they reported outcome variables necessary to measure the LC, as defined by fetal safety and efficacy. Two authors independently retrieved data, assessed the quality of the studies and categorized observations into blocks of 30 patients. For meta-analysis, data were pooled using a random-effects model when heterogeneous. To measure the LC, we used two complementary methods. In the group-splitting method, competency was defined when the procedure provided results comparable to those in the MOMS trial for 12 outcome variables representing the immediate surgical outcome, short-term neonatal neuroprotection and long-term neuroprotection at ≥ 12 months of age. Then, when raw patient data were available, we performed cumulative sum analysis based on a composite binary outcome defining successful surgery. The composite outcome combined four clinically relevant variables for safety (absence of extreme preterm delivery < 30 weeks, absence of fetal death ≤ 7 days after surgery) and efficacy (reversal of hindbrain herniation and absence of any neonatal treatment of dehiscence or cerebrospinal fluid leakage at the closure site).

RESULTS

Of 6024 search results, 17 (0.3%) studies were included, all of which had low, moderate or unclear risk of bias. Fetal SBA closure was performed using standard hysterotomy (11 studies), mini-hysterotomy (one study) or fetoscopy by either exteriorized-uterus single-layer closure (one study), percutaneous single-layer closure (three studies) or percutaneous two-layer closure (one study). Only outcomes for standard hysterotomy could be meta-analyzed. Overall, outcomes improved significantly with experience. Competency was reached after 35 consecutive cases for standard hysterotomy and was predicted to be achieved after ≥ 57 cases for mini-hysterotomy and ≥ 56 for percutaneous two-layer fetoscopy. For percutaneous and exteriorized-uterus single-layer fetoscopy, competency was not reached in the 81 and 28 cases available for analysis, respectively, and LC prediction analysis could not be performed.

CONCLUSIONS

The number of cases operated is correlated with the outcome of fetal SBA closure, and the number of operated cases required to reach competency ranges from 35 for standard hysterotomy to ≥ 56-57 for minimally invasive modifications. Our observations provide important information for institutions looking to establish a new fetal center, develop a new fetal surgery technique or train their team, and inform referring clinicians, potential patients and third parties. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Malignant primitive epithelioid sarcoma with features of rhabdoid tumor presenting in utero with diffusely metastatic disease

Diagnosis of a tumor in utero is a rare occurrence and poses diagnostic and therapeutic challenges. In cases of tumor-associated hydrops, there is significant risk of fetal demise, and prenatal intervention may be considered to avoid this outcome when possible. When fetal intervention is unlikely to improve survival, information can be useful for counseling families. We present a rare case of fetal diagnosis of a primary renal malignancy with widespread metastases and hydrops, with unique immunohistochemical findings consistent with malignant primitive epithelioid sarcoma with features of rhabdoid tumor.

Rapid endothelialization of small diameter vascular grafts by a bioactive integrin-binding ligand specifically targeting endothelial progenitor cells and endothelial cells

Establishing and maintaining a healthy endothelium on vascular and intravascular devices is crucial for the prevention of thrombosis and stenosis. Generating a biofunctional surface on vascular devices to recruit endothelial progenitor cells (EPCs) and endothelial cells (ECs) has proven efficient in promoting in situ endothelialization. However, molecules conventionally used for EPC/EC capturing generally lack structural stability, capturing specificity, and biological functionalities, which have limited their applications. Discovery of effective, specific, and structurally stable EPC/EC capturing ligands is desperately needed. Using the high-throughput One-Bead One-Compound combinatorial library screening technology, we recently identified a disulfide cyclic octa-peptide LXW7 (cGRGDdvc), which possesses strong binding affinity and functionality to EPCs/ECs, weak binding to platelets, and no binding to inflammatory cells. Because LXW7 is cyclic and 4 out of the 8 amino acids are unnatural D-amino acids, LXW7 is highly proteolytically stable. In this study, we applied LXW7 to modify small diameter vascular grafts using a Click chemistry approach. In vitro studies demonstrated that LXW7-modified grafts significantly improved EPC attachment, proliferation and endothelial differentiation and suppressed platelet attachment. In a rat carotid artery bypass model, LXW7 modification of the small diameter vascular grafts significantly promoted EPC/EC recruitment and rapidly achieved endothelialization. At 6 weeks after implantation, LXW7-modified grafts retained a high patency of 83%, while the untreated grafts had a low patency of 17%. Our results demonstrate that LXW7 is a potent EPC/EC capturing and platelet suppressing ligand and LXW7-modified vascular grafts rapidly generate a healthy and stable endothelial interface between the graft surface and the circulation to reduce thrombosis and improve patency. STATEMENT OF SIGNIFICANCE: In this study, One-Bead One-Compound (OBOC) technology has been applied for the first time in discovering bioactive ligands for tissue regeneration applications. Current molecules used to modify artificial vascular grafts generally lack EPC/EC capturing specificity, biological functionalities and structural stability. Using OBOC technology, we identified LXW7, a constitutionally stable disulfide cyclic octa-peptide with strong binding affinity and biological functionality to EPCs/ECs, very weak binding to platelets and no binding to inflammatory cells. These characteristics are crucial for promoting rapid endothelialization to prevent thrombosis and improve patency of vascular grafts. LXW7 coating technology could be applied to a wide range of vascular and intravascular devices, including grafts, stents, cardiac valves, and catheters, where a "living" endothelium and healthy blood interface are needed.

Surface modification of polymeric electrospun scaffolds via a potent and high-affinity integrin α4β1 ligand improved the adhesion, spreading and survival of human chorionic villus-derived mesenchymal stem cells: a new insight for fetal tissue engineering

Cell-biomaterial interactions are primarily governed by cell adhesion, which arises from the binding of cellular integrins to the extracellular matrix (ECM). Integrins drive the assembly of focal contacts that serve as mechanotransducers and signaling nexuses for stem cells, for example integrin α4β1 plays pivotal roles in regulating mesenchymal stem cell (MSC) homing, adhesion, migration and differentiation. The strategy to control the integrin-mediated cell adhesion to bioinspired, ECM-mimicking materials is essential to regulate cell functions and tissue regeneration. Previously, using one-bead one-compound (OBOC) combinatorial technology, we discovered that LLP2A was a high-affinity peptidomimetic ligand (IC50 = 2 pM) against integrin α4β1. In this study, we identified that LLP2A had a strong binding to human early gestation chorionic villi-derived MSCs (CV-MSCs) via integrin α4β1. To improve CV-MSC seeding, expansion and delivery for regenerative applications, we constructed artificial scaffolds simulating the structure of the native ECM by immobilizing LLP2A onto the scaffold surface as cell adhesion sites. LLP2A modification significantly enhanced CV-MSC adhesion, spreading and viability on the polymeric scaffolds via regulating signaling pathways including phosphorylation of focal adhesion kinase (FAK), and AKT, NF-kB and Caspase 9. In addition, we also demonstrated that LLP2A had strong binding to MSCs of other sources, such as bone marrow-derived mesenchymal stem cells (BM-MSCs) and adipose tissue-derived mesenchymal stem cells (AT-MSCs). Therefore, LLP2A and its derivatives not only hold great promise for improving CV-MSC-mediated treatment of fetal diseases, but they can also be widely applied to functionalize various biological and medical materials, which are in need of MSC recruitment, enrichment and survival, for regenerative medicine applications.