A Reusable Perfused Human Cadaver Model for Surgical Training: An Initial Proof of Concept Study.

OBJECTIVES: Today's surgical trainees have less exposure to open vascular and trauma procedures. Lightly embalmed cadavers may allow a reusable model that maximizes resources and allows for repeat surgical training over time. METHODS: This was a three-phased study that was conducted over several months. Segments of soft-embalmed cadaver vessels were harvested and perfused with tap water. To test durability, vessels were clamped, then an incision was made and repaired with 5-0 polypropylene. Tolerance to suturing and clamping was graded. In a second phase, both an arterial-synthetic graft and an arterial-venous anastomosis were performed and tested at 90 mmHg perfusion. In the final phase, lower extremity regional perfusion was performed and vascular control of a simulated injury was achieved. RESULTS: Seven arteries and six veins from four cadavers were explanted. All vessels accommodated suture repair over 6 weeks. There was minor leaking at all previous clamp sites. In the anastomotic phase, vessels tolerated grafting, clamping, and perfusion without tearing or leaking. Regional perfusion provided a life-like training scenario. CONCLUSIONS: Explanted vessels of soft-embalmed cadavers show adequate durability over time with realistic vascular surgery handling characteristics. This shows promise as initial proof of concept for a reusable perfused cadaver model. Further study with serial regional and whole-body perfusion is warranted.

Geographic distance to pediatric surgical care within the continental United States.

PURPOSE: Geographic proximity to pediatric surgical care has not been evaluated using the Decennial Census nor have racial, ethnic, gender, or urbanization variations been reported. This study's aim is to describe proximity of children living in the continental U.S. to a pediatric surgeon with respect to these variations. METHODS: The 2010 American Pediatric Surgical Association member file and the 2010 Decennial Census were used to calculate straight-line distances between pediatric surgeons' zip code centroids and census block centroids. RESULTS: In 2010, 716 practicing pediatric surgeons were identified, 6,182,882 populated Census blocks were identified, and 73,690,271 children were enumerated. Of white non-Hispanic children, 30.1% lived greater than 40 miles from care. Of Native American children, 40.5% lived more than 60 miles from care. Among children 0-5 years of age, the median (IQR) miles to closest pediatric surgeon was 14.2 (6.2, 39.6), and 3,010,698 of these children lived more than 60 miles from care. CONCLUSION: More than 10 million children lived greater than 60 miles from a pediatric surgeon in 2010. Racial, ethnic, age, and urbanization variations in proximity to pediatric surgeons were present. This method is feasible to describe distance-to-care with the upcoming 2020 Decennial Census and may benefit future allocation of pediatric surgeons. LEVEL OF EVIDENCE: IV.

Larger-Caliber Alternative Devices for Decompression of Tension Hemopneumothorax in the Setting of Hemorrhagic Shock.

BACKGROUND: The 14-gauge (14G) angiocatheter (AC) has an unacceptably high failure rate in treatment of tension pneumothorax (tPTX). Little is known regarding the interplay among hemorrhage, hemothorax (HTX), and tPTX. We hypothesized that increased hemorrhage predisposes tension physiology and that needle decompression fails more often with increased HTX. METHODS: This is a planned secondary analysis of data from our recent comparison of 14G AC with 10-gauge (10G) AC, modified 14G Veress needle, and 3mm laparoscopic trocar conducted in a positive pressure ventilation tension hemopneumothorax model using anesthetized swine. Susceptibility to tension physiology was extrapolated from volume of carbon dioxide (CO2) instilled and time required to induce 50% reduction in cardiac output. Failures to rescue and recover were compared between the 10% and 20% estimated blood volume (EBV) HTX groups and across devices. RESULTS: A total of 196 tension hemopneumothorax events were evaluated. No differences were noted in the volume of CO2 instilled nor time to tension physiology. HTX with 10% EBV had fewer failures compared with 20% HTX (7% versus 23%; p = .002). For larger-caliber devices, there was no difference between HTX groups, whereas smaller-caliber devices had more failures and longer time to rescue with increased HTX volume as well as increased variability in times to rescue in both HTX volume groups. CONCLUSION: Increased HTX volume did not predispose tension physiology; however, smaller-caliber devices were associated with more failures and longer times to rescue in 20% HTX as compared with 10% HTX. Use of larger devices for decompression has benefit and further study with more profound hemorrhage and HTX and spontaneous breathing models is warranted.

The non-visualized appendix and secondary signs on ultrasound for pediatric appendicitis in the community hospital setting.

BACKGROUND: Secondary signs of appendicitis on ultrasound may aid with diagnosis in the setting of a non-visualized appendix (NVA). This role has not been shown in the community hospital setting. MATERIALS AND METHODS: All right lower quadrant ultrasounds performed in children for clinical suspicion of appendicitis over a 5-year period in a single community hospital were evaluated. Secondary signs of inflammation including free fluid, ileus, fat stranding, abscess, and lymphadenopathy were documented. Patients were followed for 1 year for the primary outcome of appendicitis. These data were analyzed to determine the utility of secondary signs in the diagnosis of acute appendicitis when an NVA is reported. RESULTS: Six hundred and seventeen ultrasounds were reviewed; 470 of these had an NVA. Of NVAs, 47 (10%) of patients were diagnosed with appendicitis. Sensitivity and specificity of having at least one secondary were 38.3% and 80%, respectively. The positive and negative predictive values of having at least one secondary sign were 17.3% and 92%, respectively. CONCLUSION: These data suggest that the absence of secondary signs has a strong negative predictive value for appendicitis in the community hospital setting; however, the full utility of secondary signs may be limited in this setting.

Relative device stability of anterior versus axillary needle decompression for tension pneumothorax during casualty movement: Preliminary analysis of a human cadaver model.

BACKGROUND: Tension pneumothorax (tPTX) remains a significant cause of potentially preventable death in military and civilian settings. The current prehospital standard of care for tPTX is immediate decompression with a 14-gauge 8-cm angiocatheter; however, failure rates may be as high as 17% to 60%. Alternative devices, such as 10-gauge angiocatheter, modified Veress needle, and laparoscopic trocar, have shown to be potentially more effective in animal models; however, little is known about the relative insertional safety or mechanical stability during casualty movement. METHODS: Seven soft-embalmed cadavers were intubated and mechanically ventilated. Chest wall thickness was measured at the second intercostal space at the midclavicular line (2MCL) and the fifth intercostal space along the anterior axillary line (5AAL). CO2 insufflation created a PTX, and needle decompression was then performed with a randomized device. Insertional depth was measured between hub and skin before and after simulated casualty transport. Thoracoscopy was used to evaluate for intrapleural placement and/or injury during insertion and after movement. Cadaver demographics, device displacement, device dislodgment, and injuries were recorded. Three decompressions were performed at each site (2MCL/5AAL), totaling 12 events per cadaver. RESULTS: Eighty-four decompressions were performed. Average cadaver age was 59 years, and body mass index was 24 kg/m. The CWT varied between cadavers because of subcutaneous emphysema, but the average was 39 mm at the 2MCL and 31 mm at the 5AAL. Following movement, the 2MCL site was more likely to become dislodged than the 5AAL (67% vs. 17%, p = 0.001). Median displacement also differed between 2MCL and 5AAL (23 vs. 2 mm, p = 0.001). No significant differences were noted in dislodgement or displacement between devices. Five minor lung injuries were noted at the 5AAL position. CONCLUSION: Preliminary results from this human cadaver study suggest the 5AAL position is a more stable and reliable location for thoracic decompression of tPTX during combat casualty transport. LEVEL OF EVIDENCE: Therapeutic study, level III.

"It Happened in Seconds" Firefighter Burn Prevention Program: Evaluation of a "Train the Trainer" Course.

Each year, there are approximately 100 firefighter fatalities and tens of thousands of injuries in the United States. 'It Happened in Seconds' is a firefighter burn injury awareness program offered to firefighters nationwide. The course focuses on situational awareness, personal protective equipment, and burn injury prevention. In order to create more instructors, a 'Train the Trainer' instructor course was developed to prepare experienced firefighters and healthcare providers from around the United States to teach firefighters in their respective communities. This study evaluates trainees' perception of the instructor course. Three instructor courses were held in a period between November 2013 and January 2015. Trainees were asked to complete both precourse/postcourse assessments and provide demographics. In both surveys, trainees rated their confidence to instruct firefighters about burn prevention and their awareness about firefighter-specific burn issues using a 5-point Likert Scale (1 = none and 5 = high). The postassessment asked if trainees thought the course should be mandatory for all firefighters. Pretest and post-test scores were compared using a Wilcoxon's signed-rank test. A total of 140 experienced firefighters and healthcare professionals completed the Train the Trainer course. The average age was 40 ± 9 years, and 41 were women and 99 men. The average trainee had 13.6 ± 9 years experience in his or her respective job and 11 ± 9 years experience in burn care. Trainees reported a significant increase in their confidence to instruct firefighters about burn prevention (2.9/5 precourse vs. 4.5/5 postcourse, P < .0001) and in their current awareness of firefighter-specific burn issues (3.2 precourse vs. 4.4 postcourse, P < .0001). In the postcourse assessment, 139 of 140 respondents agreed that the 'It Happened in Seconds' course should be mandatory for all firefighters. This study showed that experienced firefighters and healthcare professionals thought that the course significantly improved their awareness level of issues specific to firefighter burn injury as well as their confidence in teaching these concepts to firefighters. Based on this positive evaluation, additional instructors will be trained to provide the course to all firefighters nationwide. Additional research must be conducted to evaluate whether the 'It Happened in Seconds' course results in a decreased rate of firefighter burn injuries.

Surgeon-Performed Hemodynamic Transesophageal Echocardiography in the Burn Intensive Care Unit.

The use of transesophageal echocardiography (TEE) for resuscitation after burn injury has been reported in small case studies. Conventional TEE is invasive and often requires a subspecialist with a high level of training. The authors report a series of surgeon-performed hemodynamic TEE with an indwelling, less bulky, user-friendly probe. Records of patients treated in a regional burn center who underwent hemodynamic TEE between October 1, 2012 and May 30, 2014 were reviewed. The clinical course of each patient was recorded. All bedside interpretations were retrospectively reviewed for accuracy by a cardiac anesthesiologist. Eleven patients were included in the study. Median age was 68.5 years (interquartile range, 49.5-79.5). Median burn size was 37% TBSA (interquartile range: 16.3-53%). Seven patients were male, and four suffered inhalation injury. The operator's interpretation matched that of the echocardiography technician and cardiac anesthesiologist in all instances. No complications occurred from probe placement. Four patients underwent hemodynamic TEE to determine volume status during resuscitation. Changes in volume status on echocardiography preceded the eventual changes in urine output and vital signs for one patient. Hemodynamic TEE diagnosed cardiogenic shock and was used to titrate inotropes and vasopressors in seven elderly patients. Hemodynamic TEE is a useful adjunct to manage the burn patient who deviates off the expected course, especially if there is a question of cardiac function or volume status. It is less invasive and can be accurately performed by surgical intensivists when transthoracic echo windows are limited. The role of echocardiography in optimizing routine burn resuscitations needs to be further studied.

The Role of Magnetic Resonance Cholangiopancreatography in the Diagnosis of Choledocholithiasis: Do Benefits Outweigh the Costs?

Endoscopic retrograde cholangiopancreatography (ERCP) is the gold standard in evaluation of the biliary tree for choledocholithiasis. Formal indications for magnetic resonance cholangiopancreatography (MRCP) in suspected choledocholithiasis are lacking. Our objective was to determine if MRCP affects management of patients who otherwise would undergo ERCP. A review was conducted of all MRCPs and ERCPs at our institution from 2008 to 2012 with suspected choledocholithiasis. Patients who underwent MRCP and ERCP were compared with those who underwent ERCP alone. Demographic data were collected and notation of whether a post-MRCP ERCP occurred was the primary variable. MRCP was performed in 107 patients for choledocholithiasis. Eighty-eight patients were negative for choledocholithiasis (82%) and 76 were discharged without ERCP (71%). Thirty-one patients received a diagnosis of choledocholithiasis and were referred for ERCP. Of the 19 patients with MRCP-diagnosed common bile duct stones, 95 per cent were confirmed by ERCP (odds ratio 18.0, P < 0.05; agreement 77%, sensitivity 0.76, specificity 0.86, positive predictive value 0.95, negative predictive value 0.50). Length of stay was similar for all groups. A total of 131 patients underwent ERCP without a preprocedural MRCP. Choledocholithiasis was found in 116 patients (92%), whereas 12 patients (9%) had no common bile duct stones and three had an alternate diagnosis. In conclusion, MRCP significantly affected the management of patients who would have undergone ERCP. MRCP did not increase length of stay and contributed to the 95 per cent positivity rate of subsequent ERCPs. These data illustrate the utility of MRCP in suspected choledocholithiasis patients at a low cost with regard to risk and time.