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.

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.