Johnathon M. Aho

Use of Unmanned Aerial Vehicles for Medical Product Transport

Advances in technology and decreasing costs have led to an increased use of unmanned aerial vehicles (UAVs) by the military and civilian sectors. The use of UAVs in commerce is restricted by US Federal Aviation Administration (FAA) regulations, but the FAA is drafting new regulations that are expected to expand commercial applications. Currently, the transportation of medical goods in times of critical need is limited to wheeled motor vehicles and manned aircraft, options that can be costly and slow. This article explores the demand for, feasibility of, and risks associated with the use of UAVs to deliver medical products, including blood derivatives and pharmaceuticals, to hospitals, mass casualty scenes, and offshore vessels in times of critical demand.

Chest wall thickness and decompression failure: A systematic review and meta-analysis comparing anatomic locations in needle thoracostomy

INTRODUCTION Current Advanced Trauma Life Support guidelines recommend decompression for thoracic tension physiology using a 5-cm angiocatheter at the second intercostal space (ICS) on the midclavicular line (MCL). High failure rates occur. Through systematic review and meta-analysis, we aimed to determine the chest wall thickness (CWT) of the 2nd ICS-MCL, the 4th/5th ICS at the anterior axillary line (AAL), the 4th/5th ICS mid axillary line (MAL) and needle thoracostomy failure rates using the currently recommended 5-cm angiocatheter. METHODS A comprehensive search of several databases from their inception to July 24, 2014 was conducted. The search was limited to the English language, and all study populations were included. Studies were appraised by two independent reviewers according to a priori defined PRISMA inclusion and exclusion criteria. Continuous outcomes (CWT) were evaluated using weighted mean difference and binary outcomes (failure with 5-cm needle) were assessed using incidence rate. Outcomes were pooled using the random-effects model. RESULTS The search resulted in 34,652 studies of which 15 were included for CWT analysis, 13 for NT effectiveness. Mean CWT was 42.79 mm (95% CI, 38.78-46.81) at 2nd ICS-MCL, 39.85 mm (95% CI, 28.70-51.00) at MAL, and 34.33 mm (95% CI, 28.20-40.47) at AAL (P=.08). Mean failure rate was 38% (95% CI, 24-54) at 2nd ICS-MCL, 31% (95% CI, 10-64) at MAL, and 13% (95% CI, 8-22) at AAL (P=.01). CONCLUSION Evidence from observational studies suggests that the 4th/5th ICS-AAL has the lowest predicted failure rate of needle decompression in multiple populations. LEVEL OF EVIDENCE Level 3 SR/MA with up to two negative criteria. STUDY TYPE Therapeutic.

Increased anatomic severity predicts outcomes: Validation of the American Association for the Surgery of Trauma's Emergency General Surgery score in appendicitis

BACKGROUND Determination and reporting of disease severity in emergency general surgery lacks standardization. Recently, the American Association for the Surgery of Trauma (AAST) proposed an anatomic severity grading system. We aimed to validate this system in patients with appendicitis and determine if cross-sectional imaging correlates with disease severity at operation. METHODS Patients 18 years or older undergoing treatment for acute appendicitis between 2013 and 2015 were identified. Baseline demographics, procedure types were recorded, and AAST grades were assigned based on intraoperative and radiologic findings. Outcomes including length of stay, 30-day mortality, and complications based on Clavien-Dindo categories and National Surgical Quality Improvement Program variables. Summary statistical univariate, nominal logistic, and standard least squares analyses were performed comparing AAST grade with key outcomes. Bland-Altman analysis compared operative findings with preoperative cross-sectional imaging to compare assigning grades. RESULTS Three hundred thirty-four patients with mean (±SD) age of 39.3 years (±16.5) were included (53% men), and all patients had cross-sectional imaging. Two hundred ninety-nine underwent appendectomy, and 85% completed laparoscopic. Thirty-day mortality rate was 0.9%, complication rate was 21%. Increased (median [interquartile range, IQR]) AAST grade was recorded in patients with complications (2 [1–4]) compared with those without (1 [1–1], p = 0.001). For operative management, (median [IQR]) AAST grades were significantly associated with procedure type: laparoscopic (1 [1–1]), open (4 [2–5]), conversion to open (3 [1–4], p = 0.001). Increased (median [IQR]) AAST grades were significantly associated in nonoperative management: patients having a complication had a higher median AAST grade (4 [3–5]) compared with those without (3 [2–3], p = 0.001). Bland-Altman analysis comparing AAST grade and cross-sectional imaging demonstrated no difference (−0.02 ± 0.02; p = 0.2; coefficient of repeatability 0.9). CONCLUSIONS The AAST grading system is valid in our population. Increased AAST grade is associated with open procedures, complications, and length of stay. The AAST emergency general surgery grade determined by preoperative imaging strongly correlated to operative findings. LEVEL OF EVIDENCE Epidemiologic/prognostic study, level III.

Free tissue transfer to the traumatized upper extremity: Risk factors for postoperative complications in 282 cases

BACKGROUND Complex traumatic upper extremity injuries frequently possess compromised local vasculature or extensive defects that are not amenable to local flap reconstruction. Free tissue transfer is required to provide adequate soft tissue coverage. The present study aimed to evaluate risk factors that contribute to postoperative complications and flap loss in complex upper extremity reconstruction. METHODS Retrospective chart review was performed for all patients undergoing free tissue transfer for upper extremity reconstruction from 1976 to 2001. Data collected included patient demographic characteristics, timing of reconstruction, location of injury, fracture characteristics, operative interventions, and postoperative complications. Statistical analysis was performed using χ(2) and Fisher exact tests. RESULTS In total, 238 patients underwent 285 free tissue transfers and met inclusion criteria, from which 3 were excluded because of inadequate information (n = 282). Extremities were repaired within 24 h (75 cases; 27%), in days 2-7 (32 cases; 12%), or after day 7 (172 cases; 62%). Timing of reconstruction did not significantly affect postoperative outcomes. Proximal location of injury was significantly associated with superficial (relative risk [RR], 6.5; P < .01) and deep infection (RR, 5.3; P < .01), and osteomyelitis (RR, 4.0; P < .01), although not with flap failure (P = .30). Presence of an open fracture was significantly associated with developing superficial (RR, 3.1; P = .01) and deep (RR, 1.9; P < .01) infection, as well as osteomyelitis (RR, 1.6; P < .01). Having a closed fracture did not negatively influence postoperative outcomes. CONCLUSIONS This study supports the safety of early free tissue transfer for reconstruction of traumatized upper extremities. Injuries proximal to the elbow and open fracture were associated with a significantly higher infection rate. Gustilo grade IIIC fractures, need for interpositional vein grafts, and anastomotic revision at index operation resulted in significantly higher risk of flap loss, whereas the presence of fracture, fracture fixation, and injury location were not predictors of flap failure.

Mentor-Guided Self-Directed Learning Affects Resident Practice

OBJECTIVE Self-directed learning (SDL) can be as effective as instructor-led training. It employs less instructional resources and is potentially a more efficient educational approach. Although SDL is encouraged among residents in our surgical training program via 24-hour access to surgical task trainers and online modules, residents report that they seldom practice. We hypothesized that a mentor-guided SDL approach would improve practice habits among our residents. DESIGN From 2011 to 2013, 12 postgraduate year (PGY)-2 general surgery residents participated in a 6-week minimally invasive surgery (MIS) rotation. At the start of the rotation, residents were asked to practice laparoscopic skills until they reached peak performance in at least 3 consecutive attempts at a task (individual proficiency). SETTING Trainees met with the staff surgeon at weeks 3 and 6 to evaluate progress and review a graph of their individual learning curve. All trainees subsequently completed a survey addressing their practice habits and suggestions for improvement of the curriculum. RESULTS By the end of the rotation, 100% of participants improved in all practiced tasks (p < 0.05), and each reported that they practiced more in this rotation than during rotations without mentor-guided SDL. Additionally, 6 (50%) residents reported that their skill level had improved relative to their peers. Some residents (n = 3) felt that the curriculum could be improved by including task-specific goals and additional practice sessions with the staff surgeon. CONCLUSIONS Mentor-guided SDL stimulated surgical residents to practice with greater frequency. This repeated deliberate practice led to significantly improved MIS skills without significantly increasing the need for faculty-led instruction. Some residents preferred more discrete goal setting and increased mentor guidance.

Every Surgical Resident Should Know How to Perform a Cricothyrotomy: An Inexpensive Cricothyrotomy Task Trainer for Teaching and Assessing Surgical Trainees

OBJECTIVE Emergency cricothyrotomy is a rare but potentially lifesaving procedure. Training opportunities for surgical residents to learn this skill are limited, and many graduating residents have never performed one during their training. We aimed to develop and validate a novel and inexpensive cricothyrotomy task trainer that can be constructed from household items. DESIGN A model was constructed using a toilet paper roll (trachea and larynx), Styrofoam (soft tissue), cardboard (thyroid cartilage), zip tie (cricoid), and fabric (skin). Participants were asked to complete a simulated cricothyrotomy procedure using the model. They were then evaluated using a 10-point checklist (5 points total) devised by 6 general surgeons. Participants were also asked to complete an anonymous survey rating the educational value and the degree of enjoyment regarding the model. SETTING A tertiary care teaching hospital. PARTICIPANTS A total of 54 students and general surgery residents (11 medical students, 32 interns, and 11 postgraduate year 3 residents). RESULTS All 54 participants completed the training and assessment. The scores ranged from 0 to 5. The mean (range) scores were 1.8 (1-4) for medical students, 3.5 (1-5) for junior residents, and 4.9 (4-5) for senior-level residents. Medical students were significantly outperformed by junior- and senior-level residents (p < 0.001). Trainees felt that the model was educational (4.5) and enjoyable (4.0). CONCLUSIONS A low-fidelity, low-cost cricothyrotomy simulator distinguished the performance of emergency cricothyrotomy between medical students and junior- and senior-level general surgery residents. This task trainer may be ideally suited to providing basic skills to all physicians in training, especially in settings with limited resources and clinical opportunities.

Increased anatomic severity in appendicitis is associated with outcomes in a South African population.

BACKGROUND Severity of emergency general surgery (EGS) diseases has not been standardized until recently. The American Association for the Surgery of Trauma (AAST) proposed an anatomic severity grading system for EGS diseases to facilitate communication and quality comparisons between providers and hospitals. Previous work has demonstrated validity of the system for appendicitis in the United States. To demonstrate generalizability, we aim to externally validate this grading system in South African patients with appendicitis. METHODS Patients with acute appendicitis during 2010 to 2016 were identified at multi-institutional sites within South Africa. Baseline demographics and procedure types were recorded, and AAST grades were assigned based on intraoperative findings. Outcomes included duration of stay, mortality, and Clavien-Dindo complications. Summary statistical univariate and nominal logistic regression analyses were performed to compare AAST grade and outcomes. RESULTS A total of 1,415 patients with a median (interquartile range) age of 19 years (14–28 years) were included (55% men). One hundred percent underwent appendectomy: 63.5% completed via midline laparotomy, 36.5% via limited incision (31.8% via McBurney incision and 4.7% via laparoscopy). Overall, 30-day mortality rate was 1.4% with an overall complication rate of 44%. Most common complications included surgical site infection (n = 147, 10.4%), pneumonia (n = 105, 7.4%), and renal failure (n = 64, 4.5%). Distribution of AAST grade is as follows: Grade 0 (10, 0.7%), Grade 1 (247, 17.4%), Grade 2 (280, 19.8%), Grade 3 (158, 11.3%), Grade 4 (179, 12.6%), and Grade 5 (541, 38.2%). Increased median (interquartile range) AAST grades were recorded in patients with complications, 5 (3–5) compared with those without (2 [1–3], p = 0.001). Duration of stay was increased for patients with higher AAST grades: 4 and 5 (10.6 ± 5.9 days) versus I and II (3.6 ± 4.3 days; p = 0.001). Area under the receiver operating characteristic analysis to predict presence of any complication based on AAST grade was 0.90. CONCLUSION The AAST EGS grading system is valid to predict important clinical outcomes in a South African population with an increased degree of severity on presentation. These results support generalizability of the AAST EGS grading system for appendicitis in a developing nation. LEVEL OF EVIDENCE Prognostic, level II.

Infected hardware after surgical stabilization of rib fractures: Outcomes and management experience

BACKGROUND Surgical stabilization of rib fracture (SSRF) is increasingly used for treatment of rib fractures. There are few data on the incidence, risk factors, outcomes, and optimal management strategy for hardware infection in these patients. We aimed to develop and propose a management algorithm to help others treat this potentially morbid complication. METHODS We retrospectively searched a prospectively collected rib fracture database for the records of all patients who underwent SSRF from August 2009 through March 2014 at our institution. We then analyzed for the subsequent development of hardware infection among these patients. Standard descriptive analyses were performed. RESULTS Among 122 patients who underwent SSRF, most (73%) were men; the mean (SD) age was 59.5 (16.4) years, and median (interquartile range [IQR]) Injury Severity Score was 17 (13–22). The median number of rib fractures was 7 (5–9) and 48% of the patients had flail chest. Mortality at 30 days was 0.8%. Five patients (4.1%) had a hardware infection on mean (SD) postoperative day 12.0 (6.6). Median Injury Severity Score (17 [range, 13–42]) and hospital length of stay (9 days [6–37 days]) in these patients were similar to the values for those without infection (17 days [range, 13–22 days] and 9 days [6–12 days], respectively). Patients with infection underwent a median (IQR) of 2 (range, 2–3) additional operations, which included wound debridement (n = 5), negative-pressure wound therapy (n = 3), and antibiotic beads (n = 4). Hardware was removed in 3 patients at 140, 190, and 192 days after index operation. Cultures grew only gram-positive organisms. No patients required reintervention after hardware removal, and all achieved bony union and were taking no narcotics or antibiotics at the latest follow-up. CONCLUSIONS Although uncommon, hardware infection after SSRF carries considerable morbidity. With the use of an aggressive multimodal management strategy, however, bony union and favorable long-term outcomes can be achieved. LEVEL OF EVIDENCE Therapeutic study, level V.

Endovascular treatment of distal thoracic aortic transection associated with severe thoracolumbar spinal fracture

Endovascular repair has become the first line of treatment in most patients with blunt aortic injury. The most common mechanism is deceleration injury affecting the aortic isthmus distal to the origin of the left subclavian artery. Injuries of the distal thoracic aorta are uncommon. We report the case of a 25-year-old male patient who presented with paraplegia and distal thoracic aortic pseudoaneurysm associated with severe thoracolumbar vertebral fracture and displacement after a motocross accident. Endovascular repair was performed using total percutaneous technique and conformable C-TAG thoracic stent-graft (WL Gore, Flagstaff, AZ). Following stent-graft placement and angiographic confirmation of absence of endoleak, thoracolumbar spinal fixation was performed in the same operative procedure. This case illustrates a multispecialty approach to complex aortic and vertebral injury and the high conformability of newer thoracic stent-grafts to adapt to tortuous anatomy.

Lumbar and thoracic perforators: vascular anatomy and clinical implications.

Background: Pedicled perforator flaps in the thoracic and lumbar regions allow reconstruction of the posterior trunk. They enable reconstruction of various local defects without microvascular anastomoses and with minimal donor-site morbidity and excellent cosmesis. The authors examined the locations of perforators in the lumbar and thoracic regions. Methods: Ten cadaver hemithoraces and lumbar regions were freshly harvested and dissected. Intraarterial injections were performed with colored latex, followed by dissection in the suprafascial plane. Perforators with a diameter larger than 0.5 cm were located and measured from the midline and from C7 (thoracic) and coccygeal (lumbar) reference points. The most dominant perforators were injected with radiopaque dye and scanned with high-resolution computed tomography. The patterns were analyzed by the quadrat counting test (based on chi-square statistics) for the null hypothesis of complete spatial randomness. Results: A total of 164 thoracic and 216 lumbar perforators were identified. These were clustered in highest density in two major areas within 10 to 20 cm of the C7 and coccygeal reference points and 10 cm from the midline; this pattern was not a random distribution (p < 0.001). Perforasomes of lumbar perforators in some instances crossed the midline, joining adjacent contralateral lumbar perforators by means of direct and indirect linking vessels. Conclusions: Lumbar and thoracic pedicled perforator flaps provide useful options for reconstructing complex defects. Use of these flaps is aided by anatomical knowledge of the location of major clusters of perforators.