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YouTube is the most used platform for case preparation by surgical trainees. Despite its popular use, studies have noted limitations in surgical technique, safety, and vetting of these videos. This study identified the most viewed laparoscopic cholecystectomy (LC) videos on YouTube and analyzed the ability of attendings, residents, and medical students to identify critical portions of the procedure, technique, and limitations of the videos. An incognito search was conducted on YouTube using the term “laparoscopic cholecystectomy.” Results were screened for length, publication date, and language. The top ten most viewed videos were presented to general surgery attendings, residents, and medical students at a single academic institution. Established rubrics were used for evaluation, including the Critical View of Safety (CVS) for LC, a modified Global Operative Assessment of Laparoscopic Skills (GOALS) score, a task-specific checklist, and visual analog scales for case difficulty and operator competence. Educational quality and likelihood of video recommendation for case preparation were evaluated using a Likert scale. Attending assessments were considered the gold standard. Six attending surgeons achieved excellent internal consistency on CVS, educational quality, and likelihood of recommendation scales, with Cronbach alpha (⍺) of 0.93, 0.92, and 0.92, respectively. ⍺ was ≥ 0.7 in all the other scales measured. Attending evaluations revealed that only one of the ten videos attained all three established CVS criteria. Four videos demonstrated none of the CVS criteria. The mean educational quality (mEQ) was 4.63 on a 10-point scale. The mean likelihood of recommendation (mLoR) for case preparation was 2.3 on a 5-point scale. Senior resident assessments (Postgraduate Year (PGY)4 + , n = 12) aligned with attending surgeons, with no statistically significant differences in CVS attainment, mEQ, and mLoR. Junior residents (PGY1-3, n = 17) and medical students (MS3-4, n = 20) exhibited significant difference with attendings in CVS attainment, mEQ, and mLoR for more than half the videos. Both groups tended to overrate videos compared to attendings. YouTube is the most popular unvetted resource used for case presentation by surgical trainees. Attending evaluations revealed that the most viewed LC videos on YouTube did not attain the CVS, and were deemed as inappropriate for case preparation, with low educational value. Senior resident video assessments closely aligned with attendings, while junior trainees were more likely to overstate video quality and value. Attending guidance and direction of trainees to high-quality, vetted resources for surgical case preparation is needed. This may also suggest a need for surgical societies with platforms for video sharing to prioritize the creation and dissemination of high-quality videos on easily accessible public platforms.

The foundational principles of surgical training in the USA are based on didactic education, structured skill training, and experiential learning in surgical patient care with the supervision of surgical faculty. A consortium of professional organizations, academic institutions, and teaching hospitals with surgical faculty provide the structural framework, policies, and curriculum to train and evaluate surgeons capable of independent practice. This manuscript describes the roles of the organizations responsible for surgical training in the USA and highlights areas in evolution in the modern surgical education landscape.

Revisional bariatric operations are associated with increased morbidity and mortality compared with primary bariatric operations. The purpose of this study was to determine if preoperative patient variables are associated with an increased risk of 30-day morbidity and mortality following revisional laparoscopic bariatric surgery for inadequate weight loss or weight recidivism and to generate expected model probabilities in order to risk stratify individual patients undergoing these operations. All patients undergoing revisional laparoscopic Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) from 2015 to 2016 were identified with the American College of Surgeons Metabolic and Bariatric Surgery Quality Improvement Program (ACS-MBSAQIP) database. The association of preoperative patient variables with 30-day morbidity and mortality was investigated using multivariable logistic regression analysis. Predictive outcome models were developed for each outcome of interest. A total of 13,551 patients met inclusion criteria; 5310 (39.2%) underwent revisional RYGB. Each of the available preoperative variables was associated with one or more of the 30-day morbidity and mortality outcomes of interest. The strength of the predictive models, as reflected by the area under the curve, ranged from 0.63 for 30-day unplanned hospital readmission to 0.92 for cardiac events. Preoperative patient and surgical variables are associated with an increased risk of 30-day morbidity and mortality following laparoscopic revisional bariatric surgery. With these results, we have built a risk calculator that can be used as a resource for prehabilitation and patient counseling prior to revisional bariatric surgery.

Surgeon and hospital volume are factors that have been shown to impact outcomes following bariatric surgery. Nevertheless, there is a paucity of literature investigating surgeon training on bariatric surgery outcomes. The purpose of our study was to determine if bariatric specialty training leads to improved short-term outcomes following laparoscopic bariatric surgery using the American College of Surgeons Metabolic and Bariatric Surgery Accreditation Quality Improvement Program (ACS-MBSAQIP) database. All patients undergoing first-time, elective, laparoscopic bariatric surgery from 2015 to 2016 were identified within the ACS-MBSAQIP database. Patients were divided into two groups based on the type of bariatric procedure performed and the surgeon performing the procedure. Thirty-day outcomes were compared between the groups using multivariable logistic regression analysis. A total of 140,340 patients met inclusion criteria. Higher risk patients with more associated comorbidities underwent bariatric surgery by a metabolic and bariatric surgeon. After controlling for these differences, patients who underwent Roux-en-Y gastric bypass (RYGB) had similar 30-day irrespective of the surgeon performing the procedure while patients who underwent sleeve gastrectomy (SG) by a metabolic and bariatric surgeon (MBS) had improved 30-day outcomes. Surgeon type is associated with 30-day morbidity and mortality outcomes for SG but not for RYGB. These differences in 30-day morbidity and mortality outcomes may be facilitated by institutional factors, surgeon experience, and participation in bariatric surgery accredited centers. Standardization of the perioperative process for both surgeons and institutions may improve 30-day morbidity and mortality outcomes for all patients who undergo laparoscopic bariatric surgery.

Dehydration is the most common cause of readmission after laparoscopic sleeve gastrectomy (SG). Bougie size and distance from the pylorus, both of which have been associated with rates of dehydration postoperatively, varies by surgeon and across institutions.To determine if there is an association between bougie size or distance from the pylorus on the rate of dehydration after laparoscopic SG.American College of Surgeons Metabolic and Bariatric Surgery Accreditation Quality Improvement Program database.All patients undergoing first-time, elective laparoscopic SG from 2015-2016 were identified. The association of bougie size and distance from the pylorus on the rate of dehydration within the first 30 days postoperatively was investigated.The inclusion criteria were met by 170,751 patients. The most commonly used bougie size was 36 Fr and the most common distance from the pylorus at which the gastric sleeve was started was 5 cm. Patients were divided into 4 groups based on bougie size and distance from the pylorus (Group 1: bougie size36 Fr, pylorus distance4 cm; Group 2: bougie size ≥36 Fr, pylorus distance4 cm; Group 3: bougie size ≥36 Fr, pylorus distance ≥4 cm; and Group 4: bougie size36 Fr, pylorus distance ≥4 cm). Patients in Group 4 were significantly less likely than any other group to experience dehydration-related complications.Both distance from the pylorus and bougie size are significantly associated with dehydration-related complications after SG. Consideration should be made for standardizing these technical aspects of SG to help reduce the rate of postoperative dehydration and hospital readmission.

Objectives: As the coronavirus disease 2019 (COVID-19) vaccine is introduced, it is critical to recognize that public opinion on vaccines is largely influenced by health communications, with YouTube being a major source of information and misinformation. This analysis graded the accuracy, quality, and reliability of the most viewed YouTube videos depicting COVID-19 and vaccinations over a 6-mo period. Methods: We collected hyperlinks for the 150 most viewed YouTube videos discussing COVID-19 from January through June 2020. Closed captioning data were searched for the term “vaccine,” yielding 32 videos. This sample was evaluated for quality, accuracy, and reliability using a rubric that incorporated existing instruments: Global Quality Scale (GQS), JAMA Benchmark Criteria, and DISCERN. Results: These 32 videos had 139,764,188 views at the time of data collection. The majority of videos received low scores, with network news sources receiving the lowest scores overall. Conclusions: The overall quality of COVID-19 YouTube videos related to vaccines may be low and raises a precautionary alert for the public consuming these videos and for health-care providers working to provide the best information to their patients. Existing scoring tools may not capture the complexities of social media. New tools could allow for a better understanding of the modern landscape of health communications.

Measures to reduce postoperative bleeding (POB) after bariatric surgery is skewed toward laparoscopic sleeve gastrectomy (LSG). We use 2015 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) to characterize the differences in bleeding rates between LSG and laparoscopic Roux-en-Y gastric bypasses (LRYGB). Propensity score matching and multivariable logistic regressions tested for independent differences in POB rates. A total of 168,093 patients from 742 centers were identified in the data set. After selection 36,925 patients with LRYGB and 20,020 patients with LSG were included in the analysis. A total of 710 (1.25%) patient suffered a POB. The independent odds of POB were 38% lower for patients having LSG compared with those having LRYGB (odds ratio, 0.62; 95% confidence interval=0.51-0.76). This difference is more pronounced with intraoperative securing of the staple line. Appropriate measures to reduce POB after each type of bariatric procedure is warranted.

Background: The rates of incidental appendiceal neoplasms after appendectomy performed for acute appendicitis is

Currently, traumatic brain injury (TBI) is detected by medical imaging; however, medical imaging requires expensive capital equipment, is time- and resource-intensive, and is poor at predicting patient prognosis. To date, direct measurement of elevated protease activity has yet to be utilized in order to detect TBI. In this work, we engineered an activity-based nanosensor for TBI (TBI-ABN) that responds to increased protease activity initiated after brain injury. We establish that a calcium-sensitive protease, calpain-1, is active in the injured brain hours within injury. We then optimize the molecular weight of a nanoscale polymeric carrier to infiltrate into injured brain tissue with minimal renal filtration. A calpain-1 substrate that generates fluorescent signal upon cleavage was attached to this nanoscale polymeric carrier to generate an engineered TBI-ABN. When applied intravenously to a mouse model of TBI, our engineered sensor is observed to locally activate in the injured brain tissue. This TBI-ABN is the first demonstration of a sensor that responds to protease activity to detect TBI.

PURPOSE OF REVIEW: Bariatric surgery is a durable and long-term solution to treat both obesity and its associated comorbidities, specifically type 2 diabetes mellitus (T2DM). Many studies have demonstrated the benefits of bariatric surgery on T2DM, but weight recidivism along with recurrence of comorbidities can be seen following these procedures. Patient compliance post-bariatric surgery is linked to weight loss outcomes and comorbidity improvement/resolution. The role of compliance with respect to T2DM medication in bariatric patients specifically has not recently been examined. This article seeks to review the role of bariatric surgery on short- and long-term resolution of T2DM, recurrence, and compliance with T2DM medication following bariatric surgery. RECENT FINDINGS: Seven randomized control trials have examined metabolic surgery versus medical therapy in glycemic control in patients meeting criteria for severe obesity. Six out of seven studies demonstrate a significant advantage in the surgical arms with regards to glycemic control, as well as secondary endpoints such as weight loss, serum lipid levels, blood pressure, renal function, and other parameters. While patient compliance with lifestyle modifications post-bariatric surgery is linked to weight loss outcomes, there are no studies to date that directly evaluate the role of lifestyle modifications and T2DM medication adherence in the management of T2DM post-bariatric surgery. SUMMARY: Bariatric surgery is an effective treatment option to achieve long-term weight loss and resolution of obesity-related medical comorbidities, specifically T2DM. Patient compliance to lifestyle modifications post-bariatric surgery is linked to weight loss outcomes and comorbidity resolution. The role of diabetic care compliance in bariatric patient outcomes, however, is poorly understood. Further studies are needed to elucidate the predictors and associated risk factors for non-compliance in this patient population.

Gastroesophageal reflux disease (GERD) affects two thirds of the American population. Obesity is also a disease that affects two thirds of the population. The pathophysiology of reflux disease is reasonably understood, however, the degree to which obesity affects this disease remains poorly defined. Therefore the approach to GERD in the obese patient requires special attention and its own algorithm. A literature search was conducted to consolidate the current available literature on GERD and its management in the obese. In addition, the authors reviewed the literature and present expert opinion on controversial topics. It is well established that GERD is increased in obesity and the pathophysiology is reviewed. Management options for GERD are discussed, with a focus on the obese population. Management strategies including fundoplication and gastric bypass are discussed. In addition, bariatric surgery in the setting of GERD is also reviewed. Currently this is an extremely controversial topic and this white paper presents a strong review of the literature to help guide the management of this challenging disease in this population. Expert recommendations are given throughout the paper based upon the current available data.

Facebook is a popular online social networking platform increasingly used for professional collaboration. Literature regarding use of Facebook for surgeon professional development and education is limited. The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) has established a Facebook group dedicated to discussion of surgery of the esophagus, stomach, and small intestine—the “SAGES Foregut Surgery Masters Program.” The aim of this study is to examine how this forum is used for professional development, education, and quality improvement. Member and post statistics were obtained from https://grytics.com , a Facebook group analytics service. All posts added to the Foregut forum since its creation in April 2015 through December 2016 were reviewed and categorized for content and topic. Posts were reviewed for potential identifiable protected health information. As of December 2016, there were 649 total members in the group. There have been a total of 411 posts and 4116 comments with a median of 10.1 comments/post (range 0–72). Posts were categorized as operative technique (64%), patient management (52%), continuing education (10%), networking (10%), or other (6%). Video and/or photos were included in 53% of posts with 4% of posts depicting radiologic studies and 13% with intraoperative photos or videos. An additional 40 posts included links to other pages, such as YouTube, journal articles, or the SAGES website. One post (0.2%) contained identifiable protected health information and was deleted once recognized by the moderators of the group. Social media is a unique, real-time platform where surgeons can learn, discuss, and collaborate towards the goal of optimal treatment of surgical disease. Active online surgical communities such as the SAGES Foregut Surgery Masters Program have the potential to enhance communication between surgeons and are a potential innovative adjunct to traditional methods of continuing surgical education. Surgical societies should adopt and promote professional and responsible use of social media.

Background/aims During dermatological forms development, one of the simplest non-invasive techniques used to evaluate cutaneous tolerance of formulations is to monitor the color changes using a tristimulus chromameter. Most published tolerance studies involving chromametric measurements are performed on Caucasian subjects. However, in the context of drug formulation for African-type populations, it is not always relevant to transpose tolerance results obtained on Caucasians populations to African-type ones due to histological ethnic differences of the skin. The goal of this work was to assess whether tristimulus chromameter can be used to highlight color variations following the application of dermatological topics on black skin in order to validate skin tolerance studies made on African-type subjects. Materials and methods After application of two commercial creams with opposite side effects (skin irritation and skin blanching) in both Africans and Caucasians populations, color variations were evaluated using a tristimulus chromameter in L* a* b* color system and compared between both populations. L* indicating color brightness, a* represents green and red directions and b* represents blue and yellow directions. Results While skin irritation resulted in a significant increase of a* parameter in both studied populations, the skin blanching resulted in a decrease of a* associated with an increase of L* . Conclusion We established that tristimulus chromameter can be used to achieve in vivo skin tolerance study of dermatologic formulations in Africans despite their dark skin even though it appeared less sensitive. This study can speed up the development of dermatological forms dedicated to Africans and/or Caucasians subjects.

Objectives To assess a multimodal physician-to-physician communication initiative that is low in cost and impact to daily workflow to reduce blood product wastage. Background Blood product stewardship is an important issue in all hospital systems. Previous studies have proposed low-cost interventions to reduce blood product wastage, but few have evaluated improvements in communication between the blood bank and providers. We undertook a prospective quality improvement project focusing on improving communication to reduce blood product wastage. Methods We conducted a prospective quality improvement project over the first quarter of 2017, identifying patients with issued but unused blood products. Each service overseeing the care of patients identified on the unit status report was contacted through two possible methods: (i) phone or (ii) proprietary Health Insurance Portability and Accountability Act of 1996 compliant digital messaging application. Collected variables included reserved blood product type and participant time spent. Outcomes included the rate of blood product release and changes in wastage compared with historical data tracked by the blood bank. Results Eight hundred and forty products were reserved during the study period, of which 436 (52%) were released. Average participant times ranged from 2 ± 1 min to 15 ± 4 min with no significant differences in time spent between participants (P = 0·194). Compared with the average product wastage 10 months prior to project initiation, there were significant reductions in the average wastage for platelets (5·3 ± 2·5 units vs 2·5 ± 1·5 units, P = 0·05), RBCs (6·1 ± 3·7 units vs 0 ± 0 units, P = 0·01) and overall wastage (58·3 ± 14·9 units vs 40 ± 15·7 units, P = 0·05). Conclusion Efforts focusing on improving provider-to-provider communication can reduce blood product wastage.

Gastroesophageal reflux can cause injury to the normal stratified squamous epithelium of the esophagus. This injury may lead to replacement of the normal esophageal lining by a metaplastic columnar intestinal-like epithelium known as Barrett’s esophagus (BE). The clinical relevance of BE lies in its sequential progression from intestinal metaplasia (IM) to low-grade dysplasia (LGD), high-grade dysplasia (HGD), and, finally, invasive adenocarcinoma. In the absence of dysplasia, BE is associated with a low annual incidence of progression to adenocarcinoma (less than 0.5), but the incidence of progression to adenocarcinoma is up to five times as high when dysplasia is present. The management of BE with dysplasia and early cancer has shifted over the years, moving away from surgical resection (esophagectomy) to diagnostic and therapeutic endoscopy. Endoscopic therapy aims to remove the metaplastic or dysplastic tissue to a depth that destroys all the BE but minimizes damage to the submucosal layer of the esophagus to avoid stricture formation and transmural injury. Several treatment options—endoscopic mucosal resection (EMR) and tissue ablative therapies such as radiofrequency ablation (RFA), photodynamic therapy (PDT), and cryotherapy (CT)—have been recognized as safe and effective therapies to accomplish this and are now the standard of care in many expert centers. This chapter will focus on the role of photodynamic therapy and cryotherapy in the management of BE.

Optoacoustic (OA) microscopy using an all-optical system based on the probe beam deflection technique (PBDT) for detection of laser-induced acoustic signals was investigated as an alternative to conventional piezoelectric transducers. PBDT provides a number of advantages for OA microscopy including (i) efficient coupling of laser excitation energy to the samples being imaged through the probing laser beam, (ii) undistorted coupling of acoustic waves to the detector without the need for separation of the optical and acoustic paths, (iii) high sensitivity and (iv) ultrawide bandwidth. Because of the unimpeded optical path in PBDT, diffraction-limited lateral resolution can be readily achieved. The sensitivity of the current PBDT sensor of 22μV/Pa and its noise equivalent pressure (NEP) of 11.4Pa are comparable with these parameters of the optical micro-ring resonator and commercial piezoelectric ultrasonic transducers. Benefits of the present prototype OA microscope were demonstrated by successfully resolving micron-size details in histological sections of cardiac muscle.

Widespread adoption of minimally invasive surgery (MIS) techniques in pediatric surgery has progressed slowly, and the shift in practice patterns has been variable among surgeons. We hypothesized that a pediatric surgeon committed to MIS could effectively change surgical practice by creating an emphasis on MIS. Annual case volumes from 2000 to 2009 at two tertiary care pediatric hospitals, one with a dedicated minimally invasive pediatric surgeon, were evaluated for trends in MIS for ten different operations. Univariate analyses of the differences between hospitals in the use of the open versus laparoscopic approach were performed. The Breslow–Day test was used to examine differences in use of laparoscopic procedures across hospitals in early versus middle and middle versus late time periods. Between the two hospitals, for 9 of the 10 types of surgery, the number of laparoscopic and open procedures differed significantly (p values ranged from

In the current era, trainees frequently use unvetted online resources for their own education, including viewing surgical videos on YouTube. While operative videos are an important resource in surgical education, YouTube content is not selected or organized by quality but instead is ranked by popularity and other factors. This creates a potential for videos that feature poor technique or critical safety violations to become the most viewed for a given procedure. A YouTube search for “Laparoscopic cholecystectomy” was performed. Search results were screened to exclude animations and lectures; the top ten operative videos were evaluated. Three reviewers independently analyzed each of the 10 videos. Technical skill was rated using the GOALS score. Establishment of a critical view of safety (CVS) was scored according to CVS “doublet view” score, where a score of ≥5 points (out of 6) is considered satisfactory. Videos were also screened for safety concerns not listed by the previous tools. Median competence score was 8 (±1.76) and difficulty was 2 (±1.8). GOALS score median was 18 (±3.4). Only one video achieved adequate critical view of safety; median CVS score was 2 (range 0–6). Five videos were noted to have other potentially dangerous safety violations, including placing hot ultrasonic shears on the duodenum, non-clipping of the cystic artery, blind dissection in the hepatocystic triangle, and damage to the liver capsule. Top ranked laparoscopic cholecystectomy videos on YouTube show suboptimal technique with half of videos demonstrating concerning maneuvers and only one in ten having an adequate critical view of safety. While observing operative videos can be an important learning tool, surgical educators should be aware of the low quality of popular videos on YouTube. Dissemination of high-quality content on video sharing platforms should be a priority for surgical societies.

Electric-field induced physical phenomena, such as thermal, mechanical and electrochemical dynamics, may be the driving mechanism behind bioeffects observed in mammalian cells during exposure to nanosecond-duration electric pulses (nsEP) in-vitro. Correlating a driving mechanism to a biological response requires the experimental measurement and quantification of all physical dynamics resulting from the nsEP stimulus. A passive and electromagnetic interference (EMI) immune sensor is required to resolve these dynamics in high strength electric fields. The probe beam deflection technique (PBDT) is a passive and EMI immune optical method for quantifying and imaging refractive index gradients in liquids and gases, both dynamic and static, with nanosecond temporal resolution. In this work, a probe beam deflection imaging system was designed to acquire 2-D time-lapse images of thermal/mechanical dynamics resulting from monopolar and bipolar nsEP stimulus.

Fluorescent lifetime imaging is an optical technique that facilitates imaging molecular interactions and cellular functions. Because the excited lifetime of a fluorophore is sensitive to its local microenvironment,1, 2 measurement of fluorescent lifetimes can be used to accurately detect regional changes in temperature, pH, and ion concentration. However, typical state of the art fluorescent lifetime methods are severely limited when it comes to acquisition time (on the order of seconds to minutes) and video rate imaging. Here we show that compressed ultrafast photography (CUP) can be used in conjunction with fluorescent lifetime imaging to overcome these acquisition rate limitations. Frame rates up to one hundred billion frames per second have been demonstrated with compressed ultrafast photography using a streak camera.3 These rates are achieved by encoding time in the spatial direction with a pseudo-random binary pattern. The time domain information is then reconstructed using a compressed sensing algorithm, resulting in a cube of data (x,y,t) for each readout image. Thus, application of compressed ultrafast photography will allow us to acquire an entire fluorescent lifetime image with a single laser pulse. Using a streak camera with a high-speed CMOS camera, acquisition rates of 100 frames per second can be achieved, which will significantly enhance our ability to quantitatively measure complex biological events with high spatial and temporal resolution. In particular, we will demonstrate the ability of this technique to do single-shot fluorescent lifetime imaging of cells and microspheres.

Short infrared laser pulses have many physiological effects on cells including the ability to stimulate action potentials in neurons. Here we show that short infrared laser pulses can also reversibly block action potentials. Primary rat hippocampal neurons were transfected with the Optopatch2 plasmid, which contains both a blue-light activated channel rhodopsin (CheRiff) and a red-light fluorescent membrane voltage reporter (QuasAr2). This optogenetic platform allows robust stimulation and recording of action potential activity in neurons in a non-contact, low noise manner. For all experiments, QuasAr2 was imaged continuously on a wide-field fluorescent microscope using a Krypton laser (647 nm) as the excitation source and an EMCCD camera operating at 1000 Hz to collect emitted fluorescence. A co-aligned Argon laser (488 nm, 5 ms at 10Hz) provided activation light for CheRiff. A 200 mm fiber delivered infrared light locally to the target neuron. Reversible action potential block in neurons was observed following a short infrared laser pulse (0.26-0.96 J/cm2; 1.37-5.01 ms; 1869 nm), with the block persisting for more than 1 s with exposures greater than 0.69 J/cm2. Action potential block was sustained for 30 s with the short infrared laser pulsed at 1-7 Hz. Full recovery of neuronal activity was observed 5-30s post-infrared exposure. These results indicate that optogenetics provides a robust platform for the study of action potential block and that short infrared laser pulses can be used for non-contact, reversible action potential block.

The accuracy of surgeons, and surgeons-in-training performing laparoscopic intestinal measurements is unknown. We evaluated the accuracy and precision of laparoscopic length measurements using a box-trainer model with and without the aid of a measuring tool. Surgical attendings, residents, and medical students were studied. A 500 cm length of rope was placed within a laparoscopic box trainer. Subjects completed two length measurements (LM). Participants measured 150 cm of rope for LM #1 and repeated the task using a 10-cm suture as a reference for LM #2. Measurement accuracy was tested by comparing mean LM between training level groups using an independent t test. Measurement precision was tested by comparing the mean deviation of LM from 150 cm. 40 attendings, 40 residents, and 50 medical students were studied. In LM #1, there were no differences in mean length accuracy measured between training level groups. Residents significantly underestimated the true 150 cm length (p

Solid pancreatic pseudopapillary tumors make up 1%-3% of all pancreatic tumors, occur predominantly in females, and usually present in the third and fourth decades of life. Less frequently, these tumors may present in children. Complete surgical excision is the treatment of choice with excellent outcomes. Usage of a laparoscopic approach has become more common for adult patients. However, the laparoscopic approach is not routinely used in the pediatric population.A literature review was performed noting 13 documented cases of solid pancreatic pseudopapillary tumors resected laparoscopically in children. We report our case series of three children with a solid pancreatic pseudopapillary tumor treated through a minimally invasive approach.In the literature, most patients had the tumor in the body or distal pancreas. The most common complication was pancreatic fistula, which was managed with total parenteral nutrition. In addition, there were reports of recurrence after biopsy of the tumor. In our case series 2 of the 3 patients received a splenectomy because of the proximity of the tumor to the spleen. There were no intraoperative or postoperative complications. Follow-up length from 13 to 36 months revealed no evidence of recurrence.In the pediatric population, solid pancreatic pseudopapillary tumors located in the body or tail of the pancreas can be managed with a laparoscopic distal pancreatectomy.

Remote chemically specific detection of trace impurities in the atmosphere from distances on the order of kilometers is an important problem from both an environmental and a national defense viewpoint. A new scheme is discussed consisting of the remote generation of a backward propagating stimulated Raman pulse. This pulse is then used to drive a coherent anti-Stokes Raman scattering scheme, resulting in a strong chemically specific signal propagating back to the detector.

Neonatal extracorporeal membrane oxygenation (ECMO) has been widely used for the last 25 y. The impact of ethno-demographic changes on ECMO outcomes has not been fully examined. We evaluated the Extracorporeal Life Support Organization registry over a 21-y period to understand these trends.A retrospective review of all neonates undergoing noncardiac ECMO in the United States between the years 1990 and 2010 was conducted based on the years of available live birth census data. Demographic, clinical, and outcome data were collated. Patient specifics, ECMO type, ECMO length, arterial blood gases, and mortality were analyzed. Univariate, bivariate, and multivariate analyses were then performed. Changes in ethnic composition of neonates on ECMO were compared with similar ethnic trend in available U.S. live birth data.Data were available for 18,130 neonates. Comparing ethnicity by year, the proportion of Caucasian neonates requiring ECMO dropped from 64.3% in 1990 to 49.5% in 2010, while African-American and Hispanic neonates on ECMO increased from 21.1% and 11.1% to 26.1% and 17.4%, respectively (P0.001). By diagnosis, congenital diaphragmatic hernia surpassed meconium aspiration syndrome as the leading indication for ECMO compared with 1990 (congenital diaphragmatic hernia, 21.5%-28.4%; meconium aspiration syndrome, 47.0%-15.7%; P0.05). ECMO mortality nearly doubled, from 18.5% to 34.0% over the study period. On adjusted analysis, African-Americans were 17% less likely to die on ECMO compared with Caucasian neonates.Neonates of ethnic minorities continue to disproportionally require ECMO support in comparison to their birth rates. Although ethnicity alone does not impact the outcome of these newborns, the increased requirement of ECMO may highlight the need for targeted education, improved prenatal care, and decision making in these groups.

Sternal fractures occur infrequently with blunt force trauma. The demographics and epidemiology of associated injuries have not been well characterized from a national trauma database. The National Trauma Data Bank was queried for patients with closed sternal fractures. The demographics were analyzed by age, gender, mechanism and indicators of anatomic and physiologic injuries. Types of commonly associated injuries were also determined. A total of 23,985 records were analyzed. Males accounted for 68.3 per cent and whites 70.9 per cent. Motor vehicle crash was the leading mechanism. More than 56 per cent had severe injuries based on Injury Severity Score (greater than 15) and 17 per cent with Glasgow Coma Score 8 or less. Crude mortality was 7.9 per cent. The majority (57.8%) and approximately one-third (33.7%) of the patients had rib fractures and lung contusions, respectively, 22.0 per cent with closed pneumothorax, 21.6 per cent had a closed thoracic vertebra fracture, 16.9 per cent with lumbar spine fracture, 3.9 per cent with concussion, and blunt cardiac injury in 3.6 per cent. Sternal fractures are usually associated with severe blunt trauma. Lung contusion remains the leading associated injury followed by vertebral spine fractures. Cardiac injuries are less frequent and vascular injuries less so. Mechanism of injury and presence of sternal fractures should alert providers to these potential associated injuries.

We recently developed a nonlinear optical imaging technique based on second harmonic generation (SHG) to identify membrane disruption events in live cells. This technique was used to detect nanoporation in the plasma membrane following nanosecond pulsed electric field (nsPEF) exposure. It has been hypothesized that similar poration events could be induced by the thermal gradients generated by infrared (IR) laser energy. Optical pulses are a highly desirable stimulus for the nervous system, as they are capable of inhibiting and producing action potentials in a highly localized but non-contact fashion. However, the underlying mechanisms involved with infrared neural stimulation (INS) are not well understood. The ability of our method to non-invasively measure membrane structure and transmembrane potential via Two Photon Fluorescence (TPF) make it uniquely suited to neurological research. In this work, we leverage our technique to understand what role membrane structure plays during INS and contrast it with nsPEF stimulation. We begin by examining the effect of IR pulses on CHO-K1 cells before progressing to primary hippocampal neurons. The use of these two cell lines allows us to directly compare poration as a result of IR pulses to nsPEF exposure in both a neuron-derived cell line, and one likely lacking native channels sensitive to thermal stimuli.

Cells exposed to nanosecond-pulsed electric fields (nsPEF) exhibit a wide variety of nonspecific effects, including blebbing, swelling, intracellular calcium bursts, apoptotic and necrotic cell death, formation of nanopores, and depletion of phosphatidylinositol 4,5-biphosphate (PIP2) to induce activation of the inositol trisphosphate/diacylglycerol pathway. While several studies have taken place in which multiple pulses were delivered to cells, the effect of pulse repetition rate (PRR) is not well understood. To better understand the effects of PRR, a laser scanning confocal microscope was used to observe CHO-K1 cells exposed to ten 600ns, 200V pulses at varying repetition rates (5Hz up to 500KHz) in the presence of either FM 1-43, YO-PRO-1, or Propidium Iodide (PI) fluorescent dyes, probes frequently used to indicate nanoporation or permeabilization of the plasma membrane. Dye uptake was monitored for 30 seconds after pulse application at a rate of 1 image/second. In addition, a single long pulse of equivalent energy (200V, 6 μs duration) was applied to test the hypothesis that very fast PRR will approximate the biological effects of a single long pulse of equal energy. Upon examination of the data, we found strong variation in the relationship between PRR and uptake in each of the three dyes. In particular, PI uptake showed little frequency dependence, FM 1-43 showed a strong inverse relationship between frequency and internal cell fluorescence, and YO-PRO-1 exhibited a “threshold” point of around 50 KHz, after which the inverse trend observed in FM 1-43 was seen to reverse itself. Further, a very high PRR of 500 KHz only approximated the biological effects of a single 6 μs pulse in cells stained with YO-PRO-1, suggesting that uptake of different dyes may proceed by different physical mechanisms.

Time-correlated single photon counting (TCSPC) enables acquisition of fluorescence lifetime decays with high temporal resolution within the fluorescence decay. However, many thousands of photons per pixel are required for accurate lifetime decay curve representation, instrument response deconvolution, and lifetime estimation, particularly for two-component lifetimes. TCSPC imaging speed is inherently limited due to the single photon per laser pulse nature and low fluorescence event efficiencies (

Time-correlated single photon counting (TCSPC) is the most robust method for fluorescence lifetime imaging using laser scanning microscopes. However, TCSPC is inherently slow making it ineffective to capture rapid events due to the single photon product per laser pulse causing extensive acquisition time limitations and the requirement of low fluorescence emission efficiency to avoid bias of measurement towards short lifetimes. Furthermore, thousands of photons per pixel are required for traditional instrument response deconvolution and fluorescence lifetime exponential decay estimation. Instrument response deconvolution and fluorescence exponential decay estimation can be performed in several ways including iterative least squares minimization and Laguerre deconvolution. This paper compares the limitations and accuracy of these fluorescence decay analysis techniques to accurately estimate double exponential decays across many data characteristics including various lifetime values, lifetime component weights, signal-to-noise ratios, and number of photons detected. Furthermore, techniques to improve data fitting, including binning data temporally and spatially, are evaluated as methods to improve decay fits and reduce image acquisition time. Simulation results demonstrate that binning temporally to 36 or 42 time bins, improves accuracy of fits for low photon count data. Such a technique reduces the required number of photons for accurate component estimation if lifetime values are known, such as for commercial fluorescent dyes and FRET experiments, and improve imaging speed 10-fold.

Recently, infrared light has been shown to both stimulate and inhibit excitatory cells. However, studies of infrared light for excitatory cell inhibition have been constrained by the use of invasive and cumbersome electrodes for cell excitation and action potential recording. Here, we present an all optical experimental design for neuronal excitation, inhibition, and action potential detection. Primary rat neurons were transfected with plasmids containing the light sensitive ion channel CheRiff. CheRiff has a peak excitation around 450 nm, allowing excitation of transfected neurons with pulsed blue light. Additionally, primary neurons were transfected with QuasAr2, a fast and sensitive fluorescent voltage indicator. QuasAr2 is excited with yellow or red light and therefore does not spectrally overlap CheRiff, enabling imaging and action potential activation, simultaneously. Using an optic fiber, neurons were exposed to blue light sequentially to generate controlled action potentials. A second optic fiber delivered a single pulse of 1869nm light to the neuron causing inhibition of the evoked action potentials (by the blue light). When used in concert, these optical techniques enable electrode free neuron excitation, inhibition, and action potential recording, allowing research into neuronal behaviors with high spatial fidelity.

A 38-year-old black woman with a medical history significant for hypertension and depression presented to the emergency department with a 2-week history of lower back pain. This visit was her second in 1 week with the same symptoms, after attaining minimal pain relief with cyclobenzaprine.

The underlying mechanism(s) responsible for nanoporation of phospholipid membranes by nanosecond pulsed electric fields (nsEP) remains unknown. The passage of a high electric field through a conductive medium creates two primary contributing factors that may induce poration: the electric field interaction at the membrane and the shockwave produced from electrostriction of a polar submersion medium exposed to an electric field. Previous work has focused on the electric field interaction at the cell membrane, through such models as the transport lattice method. Our objective is to model the shock wave cell membrane interaction induced from the density perturbation formed at the rising edge of a high voltage pulse in a polar liquid resulting in a shock wave propagating away from the electrode toward the cell membrane. Utilizing previous data from cell membrane mechanical parameters, and nsEP generated shockwave parameters, an acoustic shock wave model based on the Helmholtz equation for sound pressure was developed and coupled to a cell membrane model with finite-element modeling in COMSOL. The acoustic structure interaction model was developed to illustrate the harmonic membrane displacements and stresses resulting from shockwave and membrane interaction based on Hooke’s law. Poration is predicted by utilizing membrane mechanical breakdown parameters including cortical stress limits and hydrostatic pressure gradients.

Nanosecond pulsed electric fields (nsPEF) cause the formation of small pores, termed nanopores, in the membrane of cells. Current nanoporation models treat nsPEF exposure as a purely electromagnetic phenomenon, but recent publications showing pressure transients, ROS production, temperature gradients, and pH waves suggest the stimulus may be physically and chemically multifactorial causing elicitation of diverse biological conditions and stressors. Our research group's goal is to quantify the breadth and participation of these stressors generated during nsPEF exposure and determine their relative importance to the observed cellular response. In this paper, we used advanced imaging techniques to identify a possible source of nsPEF-induced acoustic shock waves. nsPEFs were delivered in an aqueous media via a pair of 125 μm tungsten electrodes separated by 100 μm, mirroring our previously published cellular exposure experiments. To visualize any pressure transients emanating from the electrodes or surrounding medium, we used the Schlieren imaging technique. Resulting images and measurements confirmed that mechanical pressure waves and electrode-based stresses are formed during nsPEF, resulting in a clearer understanding of the whole exposure dosimetry. This information will be used to better quantify the impact of nsPEF-induced acoustic shock waves on cells, and has provided further evidence of non-electrical-field induced exposures for elicitation of bioieffects.

Surgery has changed dramatically over the last several decades. The emergence of MIS has allowed pediatric surgeons to manage critically ill neonates, children, and adolescents with improved outcomes in pain, postoperative course, cosmesis, and return to normal activity. Procedures that were once thought to be too difficult to attempt or even contraindicated in pediatric patients in many instances are now the standard of care. New and emerging techniques, such as single-incision laparoscopy, endoscopy-assisted surgery, robotic surgery, and techniques yet to be developed, all hold and reveal the potential for even further advancement in the management of these patients. The future of MIS in pediatrics is exciting; as long as our primary focus remains centered on developing techniques that limit morbidity and maximize positive outcomes for young patients and their families, the possibilities are both promising and infinite.

Random lasers are a developing class of light sources that utilize a highly disordered gain medium as opposed to a conventional optical cavity. Although traditional random lasers often have a relatively broad emission spectrum, a random laser that utilizes vibration transitions via Raman scattering allows for an extremely narrow bandwidth, on the order of 10 cm−1. Here we demonstrate the first experimental evidence of lasing via a Raman interaction in a bulk three-dimensional random medium, with conversion efficiencies on the order of a few percent. Furthermore, Monte Carlo simulations are used to study the complex spatial and temporal dynamics of nonlinear processes in turbid media. In addition to providing a large signal, characteristic of the Raman medium, the random Raman laser offers us an entirely new tool for studying the dynamics of gain in a turbid medium., Unlike conventional lasers that require a uniform resonant cavity to operate, random lasers use a highly disordered gain medium in which scattering is dominant. Hokr et al. report Raman lasing from a bulk three-dimensional disordered medium whose intensity exceeds that of other random lasers by many orders of magnitude.

The requirement of center asymmetry for the creation of second harmonic generation (SHG) signals makes it an attractive technique for visualizing changes in interfacial layers such as the plasma membrane of biological cells. In this article, we explore the use of lipophilic SHG probes to detect minute perturbations in the plasma membrane. Three candidate probes, Di-4-ANEPPDHQ (Di-4), FM4-64, and all-trans-retinol, were evaluated for SHG effectiveness in Jurkat cells. Di-4 proved superior with both strong SHG signal and limited bleaching artifacts. To test whether rapid changes in membrane symmetry could be detected using SHG, we exposed cells to nanosecond-pulsed electric fields, which are believed to cause formation of nanopores in the plasma membrane. Upon nanosecond-pulsed electric fields exposure, we observed an instantaneous drop of ∼50% in SHG signal from the anodic pole of the cell. When compared to the simultaneously acquired fluorescence signals, it appears that the signal change was not due to the probe diffusing out of the membrane or changes in membrane potential or fluidity. We hypothesize that this loss in SHG signal is due to disruption in the interfacial nature of the membrane. The results show that SHG imaging has great potential as a tool for measuring rapid and subtle plasma membrane disturbance in living cells.

The time-temperature effects of laser radiation exposure are investigated as a function of wavelength. Here, we report the thermal response of bulk tissue as a function of wavelength from 700 to 1064 nm. Additionally, Monte Carlo simulations were used to verify the thermal response measured and predict damage thresholds based on the response.

Nonlinear optical probes, especially those involving second harmonic generation (SHG), have proven useful as sensors for near-instantaneous detection of alterations to or ientation or energetics within a substance. This has been exploited to some success for observing conformational changes in proteins. SHG probes, therefore, hold promise for reporting rapid and minute changes in lipid membranes. In this report, one of these probes is employed in this regard, using nanosecond electric pulses (nsEPs) as a vehicle for instigating subtle membrane perturbations. The result provides a useful tool and methodology for the observation of minute membrane perturbation, while also providing meaningful information on the phenomenon of electropermeabilization due to nsEP. The SHG probe Di-4-ANEPPDHQ is used in conjunction with a tuned optical setup to demonstrate nanoporation preferential to one hemisphere, or pole, of the cell given a single square shaped pulse. The results also confirm a correlation of pulse width to the amount of poration. Furthermore, the polarity of this event and the membrane physics of both hemispheres, the poles facing either electrode, were tested using bipolar pulses consisting of two pulses of opposite polarity. The experiment corroborates findings by other researchers that these types of pulses are less effective in causing repairable damage to the lipid membrane of cells.

Despite 30 years of research, the mechanism behind the induced breakdown of plasma membranes by electrical pulses, termed electroporation, remains unknown. Current theories treat the interaction between the electrical field and the membrane as an entirely electrical event pointing to multiple plausible mechanisms. By investigating the biophysical interaction between plasma membranes and nanosecond electrical pulses (nsEP), we may have identified a non-electric field driven mechanism, previously unstudied in nsEP, which could be responsible for nanoporation of plasma membranes. In this investigation, we use a non-contact optical technique, termed probe beam deflection technique (PBDT), to characterize acoustic shockwaves generated by nsEP traveling through tungsten wire electrodes. We conclude these acoustic shockwaves are the result of the nsEP exposure imparting electrohydraulic forces on the buffer solution. When these acoustic shockwaves occur in close proximity to lipid bilayer membranes, it is possible that they impart a sufficient amount of mechanical stress to cause poration of that membrane. This research establishes for the first time that nsEP discharged in an aqueous medium generate measureable pressure waves of a magnitude capable of mechanical deformation and possibly damage to plasma membranes. These findings provide a new insight into the longunanswered question of how electric fields cause the breakdown of plasma membranes.

Blood products containing leukocytes have been associated with negative immunomodulatory and infectious effects. Transfusion-related acute lung injury is partially explained by leucocyte agglutination. The Food and Drug Administration has therefore recommended leukoreduction strategies for blood product transfusion. Our institution has been using leukocyte-reduced blood via filtration for neonates on Extracorporeal Membrane Oxygenation (ECMO). We hypothesized that the use of leukocyte-reduced blood would decrease mortality and morbidity of neonatal ECMO patients.Retrospective review of noncardiac ECMO in neonates from 1984-2011, stratified into year groups I and II (≤1996 and ≥1997). Demographics, duration and type of ECMO, complications, and outcome data were collected. Blood product use data was collected. Univariate, bivariate, and multivariate analyses determined predictors of risk-adjusted mortality by year group.Patients (827) underwent ECMO with 65.3% (540) in group I. Overall median blood product use in mL/kg/d was 36.2 packed red blood cells (pRBC), 8.1 platelets, and 0 cyroprecipitate and/or fresh-frozen plasma. Overall mortality was 16.4%. Median pRBC used or transfused was 42.1 mL/kg/d in group I versus 19.1 mL/kg/d group II (P0.001). On bivariate analysis, there was no difference in crude mortality between the 2 year groups (17.2% versus 16.0%, P = 0.66). However, on multivariate analysis adjusting for demographics, diagnosis, complications, and blood product use other than pRBCs, each additional transfusion of 10 mL/kg/d of pRBC was associated with a 33% increase in mortality in group I (P0.05). Group II also showed an increase in mortality with each additional transfusion (21%) but this was not statistically significant (P = 0.07). Days on ECMO were not associated with pRBC transfusion in group I but increased in group II (additional 3 d for each 10 mL/kg/d transfused). There was no difference in infectious complications between groups I and II.Blood transfusion requirement has diminished in newborns undergoing ECMO at our institution. Transfusion of non leukocyte-reduced blood is associated with an increase in mortality whereas transfusion of leukocyte-reduced blood provided no benefit with a trend toward increased mortality. Further research is recommended to understand these trends.

The study of living cells may require advanced imaging techniques to track weak and rapidly changing signals. Fundamental to this need is the recent advancement in camera technology. Two camera types, specifically sCMOS and EM-CCD, promise both high signal-to-noise and high speed (>100 fps), leaving researchers with a critical decision when determining the best technology for their application. In this article, we compare two cameras using a live-cell imaging test case in which small changes in cellular fluorescence must be rapidly detected with high spatial resolution. The EM-CCD maintained an advantage of being able to acquire discernible images with a lower number of photons due to its EM-enhancement. However, if high-resolution images at speeds approaching or exceeding 1000 fps are desired, the flexibility of the full-frame imaging capabilities of sCMOS is superior.

The optical damaging potential of near-infrared radiation was investigated as a function of wavelength. Higher incident powers can be afforded by using longer wavelength excitation leading to deeper imaging depths.

Nontraumatic symptomatic hypotension in all patients requires prompt diagnosis and appropriate treatment for optimum outcome. The female population specifically has an expanded differential diagnosis that should be considered when these patients present with hemodynamic collapse. While the most common causes of hypotension in pregnant patients are dehydration, ruptured ectopic pregnancy, and placental and uterine abnormalities, less common nonobstetrical etiologies such as hepatic rupture and ruptured abdominal and visceral artery aneurysms should also be considered. Splenic artery aneurysms are associated with high rates of mortality and in cases of pregnancy, maternal and fetal mortality. These high rates can be attributed to the asymptomatic nature of the aneurysm, rapid deterioration after rupture, and frequent misdiagnosis. In patients with hemodynamic collapse, the role of traditional imaging is limited mainly due to the critical condition of the patient. Bedside ultrasound has emerged as a diagnostic imaging resource in patients with undifferentiated hypotension and in patients with traumatic injuries. However, its use has not been studied specifically in the female population. We present two patients with ruptured splenic artery aneurysms, discuss the role of bedside ultrasound in their management, and introduce a new ultrasound protocol for use in reproductive age female patients with hemodynamic collapse.