Evaluation of a Military Global Health Engagement Mission for Critical Wartime Surgical Specialty Readiness.

INTRODUCTION: Surgical volume at Military Treatment Facilities (MTFs) has been gradually decreasing for roughly the past 2 decades. The Knowledge, Skills, and Abilities (KSA) Clinical Readiness Program linked surgical volume and readiness using a tool known as the KSA metric. However, the extent to which military medical missions contribute to the readiness of critical wartime specialties has not been evaluated using this metric. METHODS: In this study, a retrospective analysis was conducted using the surgical case logs from the US Naval Ship (USNS) Comfort missions in 2018 and 2019. The comprehensive case log data were categorized by year, surgeon, procedure, and location. The analysis focused on providing detailed descriptive statistics, including percentages pertaining to the types of procedures performed during these missions. The 2018 mission was 11 weeks in duration, and supported activities in Ecuador, Peru, Colombia, and Honduras. The USNS Comfort mission in 2019 lasted 6 months (June-November 2019), and visited 12 countries in Central America, South America, and the Caribbean. RESULTS: The 2019 mission case log, spanning 6 months, was evaluated using the KSA score in order to assess readiness and compare against 6 months of MTF KSA values within the same calendar year. In 2019, the orthopedic surgeon aboard the USNS Comfort had a total KSA score of 44,006, but the 6-month USNS Comfort mission only contributed 5,364 points (12% of the annual score). The general surgery practice aboard the USNS Comfort produced lower KSA scores compared to each surgeon's respective MTF practice (Table III). Analyzing the cases logged by general surgeons also highlights minimal surgical diversity during these missions, with more than 90% of cases being hernia repairs or laparoscopic cholecystectomies (Table I). In addition, 35% of total procedures performed in 2018 and 2019 were performed laparoscopically. CONCLUSIONS: The analysis of operative data from the 2019 USNS Comfort mission, in comparison with the surgeons' work at their respective MTFs, reveals limited benefit in the ability of hospital-ship missions to bolster surgical readiness as measured by the KSA score. However, this is not a reflection on the value of Global Health Engagement (GHE) itself but a review of the way in which it is leveraged to support surgical readiness. Military surgeons participate in GHE as part of a larger strategy to strengthen relationships with partner nations, improve military medical force interoperability, and bolster partner nation medical capacity and capabilities. The KSA score offers an excellent tool to compare readiness metrics across significantly different GHE missions, and facilitates the opportunity for future prospective studies to improve case volume, diversity, and ultimately readiness.

Complicated retroperitoneal diverticulitis presenting with abscess and acute limb ischemia.

This case highlights a rare presentation of diverticulitis of the sigmoid colon with perforation into the retroperitoneum complicated by abscess, vertebral osteomyelitis and acute lower extremity ischemia. A late 40-year-old man presented to an emergency department with acute ischemia of his left lower extremity. He was tachycardic with a leucocytosis, an unremarkable abdominal exam and a pulseless, insensate and paralysed left lower extremity. Imaging revealed sigmoid thickening, an abscess adjacent to iliac vasculature and occlusion of the left popliteal artery. The abscess came in contact with prior spine anterior lumbar interbody fusion (ALIF) hardware at L5-S1 vertebrae. The patient was taken urgently to the operating room for embolectomy, thrombectomy and fasciotomy. He was started on antibiotics and later underwent operative drainage with debridement for osteomyelitis. Non-operative management of the complicated diverticulitis failed, necessitating open sigmoidectomy with colostomy. 1 year later, he was symptom-free and the colostomy was reversed.

Iatrogenic immunodeficiency-associated lymphoproliferative disorder presenting as small bowel perforation.

A woman in her late 50s on mycophenolate for limited systemic sclerosis presented with abdominal pain. Vital signs and investigative evaluations were normal. Cross-sectional imaging identified gastric and small bowel wall thickening, free fluid, and pneumoperitoneum. In the operating room, a small bowel perforation was found and resected. Postoperatively, immunosuppression was held and she completed a course of amoxicillin/clavulanate. She discharged home and re-presented on postoperative day 8 with seizures and was found to have a frontal brain mass which was biopsied. Pathology from both the resected bowel and brain biopsy demonstrated Epstein-Barr virus-positive B-cell lymphoproliferative disorder with polymorphic B-cell features. The patient's immunosuppression was discontinued, and she was enrolled in a clinical trial for chemotherapy. Lymphoproliferative disorder can present years after immunosuppression initiation with either spontaneous perforation or solid tumour. Pathological assessment determines treatment options. Heightened concern for atypical clinical presentations in immunosuppressed patients is always warranted.

Simple signage and targeted education can lead to process improvement in acute appendicitis care.

INTRODUCTION: An institution-wide protocol for uncomplicated acute appendicitis was created to improve compliance with best practices between the emergency department (ED), radiology and surgery. Awareness of the protocol was spread with the publication of a smartphone application and communication to clinical leadership. On interim review of quality metrics, poor protocol adherence in diagnostic imaging and antimicrobial stewardship was observed. The authors hypothesised that two further simple interventions would result in more efficient radiographic diagnosis and antimicrobial administration. MATERIALS AND METHODS: Surgery residents received targeted in-person education on the appropriate antibiotic choices and diagnostic imaging in the protocol. Signs were placed in the emergency and radiology work areas, immediately adjacent to provider workstations highlighting the preferred imaging for patients with suspected appendicitis and the preferred antibiotic choices for those with proven appendicitis. Protocol adherence was compared before and after each intervention. RESULTS: Targeted education was associated with improved antibiotic stewardship within the surgical department from 30% to 91% protocol adherence before/after intervention (p<0.005). Visible signs in the ED were associated with expedited antimicrobial administration from 50% to 90% of patients receiving antibiotics in the ED prior to being brought to the operating room before/after intervention (p<0.005). Diagnostic imaging after the placement of signs showed improved protocol adherence from 35% to 75% (p<0.005). CONCLUSION: This study demonstrates that smartphone-based applications and communication among clinical leadership achieved suboptimal adherence to an institutional protocol. Targeted in-person education reinforcement and visible signage immediately adjacent to provider workstations were associated with significantly increased adherence. This type of initiative can be used in other aspects of acute care general surgery to further improve quality of care and hospital efficiency.

A Decade of Surgery Aboard the U.S. Naval Ship COMFORT (T-AH 20).

INTRODUCTION: The U.S. Naval Ship COMFORT has performed six humanitarian assistance and disaster relief mission since 2007. This paper describes the surgical volume per surgical specialty for five missions spanning 19 countries. MATERIALS AND METHODS: Raw surgical case logs were analyzed for total case volume, total operating days, unanticipated return to operating room, and percentage of pediatric cases (<18 years old) for each country visited. RESULTS: Total surgical volume for the five missions was 5,142. The countries most frequently visited were Columbia and Haiti with seven and five visits, respectively. General surgery, ophthalmology, and plastic surgery have had consistent volume over time. Orthopedic surgery volume has steadily decreased with the exception of the 2018 mission. CONCLUSION: As volume in military treatment facilities declines, alternative sources of surgical volume for military surgeons are being examined. This paper highlights the historical volume which can inform future personnel planning requirements of U.S. Naval Ship COMFORT missions. With the exception of orthopedic surgery, surgical volume has remained consistent over the last decade. For future best practice, historical case data should be used to determine staffing needs on hospital ships and case logs and operating procedures and follow-up protocols should be standardized.

Risk Factors for Urgent or Emergent Cholecystectomy Mid-workup for Symptomatic Cholelithiasis.

BACKGROUND: Patients who undergo cholecystectomy often do so for diagnoses related to the sequelae of gallstones. Many patients present acutely, requiring urgent removal due to complications of cholelithiasis. This study aims to characterize the patient population likely to present acutely during ongoing workup for cholelithiasis to better identify those who may benefit from expedited care. METHODS: Medical records of all adult patients who underwent cholecystectomy for indications related to cholelithiasis between 2015 and 2016 were reviewed retrospectively. Qualitative data was analyzed using Chi square test and quantitative data was analyzed using independent t-tests. RESULTS: One hundred and seventy-four cholecystectomies were performed. Overall, 74.2% of the procedures were done electively while 25.8% were done urgently. And 42.2% of patients who underwent acute surgical intervention had evidence of prior workup. Patients requiring urgent intervention during ongoing diagnostic evaluation were more likely to have initially presented to an emergency department (ED) than another provider (68.4% vs 31.3%, P < .001) and had an odds ratio of 4.7 for undergoing acute intervention if they initially presented to the ED. They also tended to be more temporally remote from their initial diagnosis (119 ± 142 vs 74.6 ± 68.2 days, P < .19) relative to those who underwent elective operations. DISCUSSION: Patients who require urgent intervention during ongoing workup for cholelithiasis have prolonged courses of care and present to the ED more often for initial evaluation when compared to those who undergo elective intervention. These findings suggest that an emphasis on expedited workup of cholelithiasis and early surgical referral may be warranted, especially for those who initially present in the ED.

To Scan or Not to Scan: Development of a Clinical Decision Support Tool to Determine if Imaging Would Aid in the Diagnosis of Appendicitis.

BACKGROUND: Appendicitis is one of the most common surgically treated diseases in the world. CT scans are often over-utilized and ordered before a surgeon has evaluated the patient. Our aim was to develop a tool using machine learning (ML) algorithms that would help determine if there would be benefit in obtaining a CT scan prior to surgeon consultation. METHODS: Retrospective chart review of 100 randomly selected cases who underwent appendectomy and 100 randomly selected controls was completed. Variables included components of the patient's history, laboratory values, CT readings, and pathology. Pathology was used as the gold standard for appendicitis diagnosis. All variables were then used to build the ML algorithms. Random Forest (RF), Support Vector Machine (SVM), and Bayesian Network Classifiers (BNC) models with and without CT scan results were trained and compared to CT scan results alone and the Alvarado score using area under the Receiver Operator Curve (ROC), sensitivity, and specificity measures as well as calibration indices from 500 bootstrapped samples. RESULTS: Among the cases that underwent appendectomy, 88% had pathology-confirmed appendicitis. All the ML algorithms had better sensitivity, specificity, and ROC than the Alvarado score. SVM with and without CT had the best indices and could predict if imaging would aid in appendicitis diagnosis. CONCLUSION: This study demonstrated that SVM with and without CT results can be used for selective imaging in the diagnosis of appendicitis. This study serves as the initial step and proof-of-concept to externally validate these results with larger and more diverse patient population.

Grilling pains: case series of four patients needing operative intervention after accidental ingestion of a wire bristle.

Accidental ingestion of a grill brush wire bristle is a rare event. Retrieval rarely requires surgical intervention as the wire typically causes symptoms above the gastro-oesophageal junction and can frequently be removed endoscopically. There are few reported cases of gastrointestinal injury due to ingestion of wire bristles lodging past the gastro-oesophageal junction in adults. We present four cases of wire brush bristle ingestion that required operative intervention. Our case series illustrates how the commonly used wire grill brush may cause a serious injury. This diagnosis should be considered in patients who present with abdominal pain, non-specific symptoms and normal labs, with liner radio-opaque imaging findings and a history of grill use. Education as to the dangers of grill wire brushes to clean grills should be provided commercially.

Keeping tabs: Reducing postoperative opioid prescriptions for patients after breast surgical procedures.

BACKGROUND: As the opioid crisis continues, it is critical that health care providers ensure they are not overprescribing opioid medications. At our institution (Walter Reed National Military Medical Center, Bethesda, MD), postoperative patients after breast surgeries are discharged with variable amounts of opioid medications. However, many patients report minimal opioid use. The objectives of this study were to characterize postoperative opioid usage and prescribing practices for patients undergoing various breast surgeries and to recommend the number of opioid pills for discharge for each procedure. METHODS: This was a prospective, single-institution study of all patients undergoing breast surgery from October 2018 to 2019. All patients were enrolled in our institution's enhanced recovery after surgery protocol. Patients were given questionnaires at their 2-week postoperative clinic appointment that evaluated perioperative pain and use of pain medications. The electronic medical record was reviewed to obtain additional information. Appropriate parametric and nonparametric tests were used for analysis. RESULTS: A total of 190 breast surgery patients completed the survey. We observed no significant differences in pain scores except between re-excision and mastectomy. Of these patients, 99% were prescribed opioids; however, only 53% of patients used them. Of those patients who were prescribed opioids, on average, all were prescribed more pills than were used. CONCLUSION: Our study demonstrates that it is possible to discharge all breast surgery patients with fewer than 10 opioid pills, except for special circumstances. This is the first study to provide a set of specific recommended discharge medications. Utilization of an enhanced recovery after surgery protocol with standardized discharge opioids can be used successfully to reduce the number of opioids prescribed to patients.

Technical Note: On maximizing Cherenkov emissions from medical linear accelerators.

PURPOSE: Cherenkov light during MV radiotherapy has recently found imaging and therapeutic applications but is challenged by relatively low fluence. Our purpose is to investigate the feasibility of increasing Cherenkov light production during MV radiotherapy by increasing photon energy and applying specialized beam-hardening filtration. METHODS: GAMOS 5.0.0, a GEANT4-based framework for Monte Carlo simulations, was used to model standard clinical linear accelerator primary photon beams. The photon source was incident upon a 17.8 cm3 cubic water phantom with a 94 cm source to surface distance. Dose and Cherenkov production was determined at depths of 3-9 cm. Filtration was simulated 15 cm below the photon beam source. Filter materials included aluminum, iron, and copper with thicknesses of 2-20 cm. Histories used depended on the level of attenuation from the filter, ranging from 100 million to 2 billion. Comparing average dose per history also allowed for evaluation of dose-rate reduction for different filters. RESULTS: Overall, increasing photon beam energy is more effective at improving Cherenkov production per unit dose than is filtration, with a standard 18 MV beam yielding 3.3-4.0× more photons than 6 MV. Introducing an aluminum filter into an unfiltered 2400 cGy/min 10 MV beam increases the Cherenkov production by 1.6-1.7×, while maintaining a clinical dose rate of 300 cGy/min, compared to increases of ~1.5× for iron and copper. Aluminum was also more effective than the standard flattening filter, with the increase over the unfiltered beam being 1.4-1.5× (maintaining 600 cGy/min dose rate) vs 1.3-1.4× for the standard flattening filter. Applying a 10 cm aluminum filter to a standard 18 MV, photon beam increased the Cherenkov production per unit dose to 3.9-4.3× beyond that of 6 MV (vs 3.3-4.0× for 18 MV with no aluminum filter). CONCLUSIONS: Through a combination of increasing photon energy and applying specialized beam-hardening filtration, the amount of Cherenkov photons per unit radiotherapy dose can be increased substantially.

Instituting a Surgical Skills Competition Increases Technical Performance of Surgical Clerkship Students Over Time.

INTRODUCTION: Surgical skills training varies greatly between institutions and is often left to students to approach independently. Although many studies have examined single interventions of skills training, no data currently exists about the implementation of surgical skills assessment as a component of the medical student surgical curriculum. We created a technical skills competition and evaluated its effect on student surgical skill development. METHODS: Second-year medical students enrolled in the surgery clerkship voluntarily participated in a surgical skills competition consisting of knot tying, laparoscopic peg transfer, and laparoscopic pattern cut. Winning students were awarded dinner with the chair of surgery and a resident of their choice. Individual event times and combined times were recorded and compared for students who completed without disqualification. Disqualification included compromising cutting pattern, dropping a peg out of the field of vision, and incorrect knot tying technique. Timed performance was compared for 2 subsequent academic years using Mann-Whitney U test. RESULTS: Overall, 175 students competed and 71 students met qualification criteria. When compared by academic year, 2015 to 2016 students (n = 34) performed better than 2014 to 2015 students (n = 37) in pattern cut (133s vs 167s, p = 0.040), peg transfer (66s vs 101s, p < 0.001), knot tying (28s vs 30s, p = 0.361), and combined time (232s vs 283s, p = 0.009). The best time for each academic year also improved (105s vs 110s). Fundamentals of Laparoscopic Surgery proficiency standards for examined tasks were achieved by 70% of winning students. CONCLUSIONS: Implementation of an incentivized surgical skills competition improves student technical performance. Further research is needed regarding long-term benefits of surgical competitions for medical students.

Extracorporeal Membrane Oxygenation and Interfacility Transfer: A Regional Referral Experience.

BACKGROUND: The number of adults referred to high-volume centers for extracorporeal membrane oxygenation (ECMO) is increasing. Outcomes of patients requiring transport are not well characterized, and referral guidelines are lacking. This study describes the experience and outcomes of a single high-volume center. METHODS: A retrospective study was performed that included adults undergoing ECMO between June 2009 and December 2015. Patient characteristics and outcomes were acquired from the medical record. Logistic regression was used to identify predictors of survival to hospital discharge. The Kaplan-Meier method was used to depict rates of survival. RESULTS: Of 133 patients, 77 (57.9%) underwent venoarterial (VA) ECMO and 56 (42.1%) underwent venovenous (VV) ECMO. Median transport distance was 88.8 miles (range 0.2-1,434 miles). Median duration of support was 6 days (range, 1-32.5 days). Age older than 60 years, pulmonary hypertension, and body mass index (BMI) greater than 30 were associated with worse survival to discharge for VA ECMO; a history of hypertension and presence of left ventricular (LV) vent were associated with better survival. Age older than 60 years and diabetes were associated with worse survival to hospital discharge for VV ECMO. Survival to decannulation was 66.2% and 76.8%, and to hospital discharge it was 48.1% and 69.6% for VA and VV ECMO, respectively. Of hospital survivors, Kaplan-Meier estimates of 1-year survival were 82.4% and 95.5% for VA and VV, respectively. CONCLUSIONS: Outcomes are favorable after transport to high-volume ECMO centers. Guidelines and infrastructure for short- and long-distance ECMO transport is imperative for the efficient and successful management of these patients.

Microdosimetric and Biological Effects of Photon Irradiation at Different Energies in Bone Marrow.

To ensure reliability and reproducibility of radiobiological data, it is necessary to standardize dosimetry practices across all research institutions. The photoelectric effect predominates over other interactions at low energy and in high atomic number materials such as bone, which can lead to increased dose deposition in soft tissue adjacent to mineral bone due to secondary radiation particles. This may produce radiation effects that deviate from higher energy photon irradiation that best model exposure from clinical radiotherapy or nuclear incidences. Past theoretical considerations have indicated that this process should affect radiation exposure of neighboring bone marrow (BM) and account for reported differences in relative biological effectiveness (RBE) for hematopoietic failure in rodents. The studies described herein definitively estimate spatial dose distribution and biological effectiveness within the BM compartment for (137)Cs gamma rays and 320 kVp X rays at two levels of filtration: 1 and 4 mm Cu half-value layer (HVL). In these studies, we performed: 1. Monte Carlo simulations on a 5 µm resolution model of mouse vertebrae and femur derived from micro-CT images; 2. In vitro biological experiments irradiating BM cells plated directly on the surface of a bone-equivalent material (BEM); and 3. An in vivo study on BM cell survival in irradiated live mice. Simulation results showed that the relative dose increased in proximity to bone at the lower radiation energies and produced averaged values of relative dose over the entire BM volume within imaged trabecular bone of 1.17, 1.08 and 1.01 for beam qualities of 1 mm Cu HVL, 4 mm Cu HVL and (137)Cs, respectively. In accordance with Monte Carlo simulations, in vitro irradiation of BM cells located on BEM and in vivo whole-body irradiation at a prescribed dose to soft tissue of 6 Gy produced relative cell killing of hematopoietic progenitors (CFU-C) that significantly increased for the 1 mm Cu HVL X rays compared to radiation exposures of higher photon energies. Thus, we propose that X rays of the highest possible kVp and filtration be used to investigate radiation effects on the hematopoietic system, as this will allow for better comparisons with high-energy photon exposures applied in radiotherapy or as anticipated in a nuclear event.

Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators.

PURPOSE: Accurate dosimetry is essential when irradiating mice to ensure that functional and molecular endpoints are well understood for the radiation dose delivered. Conventional methods of prescribing dose in mice involve the use of a single dose rate measurement and assume a uniform average dose throughout all organs of the entire mouse. Here, the authors report the individual average organ dose values for the irradiation of a 12, 23, and 33 g mouse on a 320 kVp x-ray irradiator and calculate the resulting error from using conventional dose prescription methods. METHODS: Organ doses were simulated in the Geant4 application for tomographic emission toolkit using the MOBY mouse whole-body phantom. Dosimetry was performed for three beams utilizing filters A (1.65 mm Al), B (2.0 mm Al), and C (0.1 mm Cu + 2.5 mm Al), respectively. In addition, simulated x-ray spectra were validated with physical half-value layer measurements. RESULTS: Average doses in soft-tissue organs were found to vary by as much as 23%-32% depending on the filter. Compared to filters A and B, filter C provided the hardest beam and had the lowest variation in soft-tissue average organ doses across all mouse sizes, with a difference of 23% for the median mouse size of 23 g. CONCLUSIONS: This work suggests a new dose prescription method in small animal dosimetry: it presents a departure from the conventional approach of assigninga single dose value for irradiation of mice to a more comprehensive approach of characterizing individual organ doses to minimize the error and uncertainty. In human radiation therapy, clinical treatment planning establishes the target dose as well as the dose distribution, however, this has generally not been done in small animal research. These results suggest that organ dose errors will be minimized by calibrating the dose rates for all filters, and using different dose rates for different organs.

A feasibility study using radiochromic films for fast neutron 2D passive dosimetry.

The objective of this paper is threefold: (1) to establish sensitivity of XRQA and EBT radiochromic films to fast neutron exposure; (2) to develop a film response to radiation dose calibration curve and (3) to investigate a two-dimensional (2D) film dosimetry technique for use in establishing an experimental setup for a radiobiological irradiation of mice and to assess the dose to the mice in this setup. The films were exposed to a 10 MeV neutron beam via the (2)H(d,n)(3)He reaction. The XRQA film response was a factor of 1.39 greater than EBT film response to the 10 MeV neutron beam when exposed to a neutron dose of 165 cGy. A film response-to-soft tissue dose calibration function was established over a range of 0-10 Gy and had a goodness of fit of 0.9926 with the calibration data. The 2D film dosimetry technique estimated the neutron dose to the mice by measuring the dose using a mouse phantom and by placing a piece of film on the exterior of the experimental mouse setup. The film results were benchmarked using Monte Carlo and aluminum (Al) foil activation measurements. The radiochromic film, Monte Carlo and Al foil dose measurements were strongly correlated, and the film within the mouse phantom agreed to better than 7% of the externally mounted films. These results demonstrated the potential application of radiochromic films for passive 2D neutron dosimetry.