Development of a contrast-enhanced ultrasound guided high intensity focused ultrasound system for coagulation of liver parenchyma.

BACKGROUND: The liver is the most common organ injured in blunt abdominal trauma and makes up roughly 5% of all trauma admissions. Current treatments are invasive and resource-intensive, which may delay care. We aim to develop and validate a contrast-enhanced ultrasound (CEUS)guided noninvasive tool to treat liver lacerations at the bedside. METHODS: Two 1.8 MHz high-intensity focused ultrasound (HIFU) elements were coupled to a C1-6 diagnostic ultrasound probe and a Logiq E10 scanner (GE HealthCare) utilizing a custom enclosure for co-registered imaging and ablation. A phantom was created from polyacrylamide gel combined with thermochromic ink whose color changes above biological ablative temperatures (60 °C). The HIFU wave was focused approximately 0.5 cm below the surface utilizing a 50% duty cycle generating 11.9 MPa for 20, 30, 40, 50, and 60s. Experiments were repeated on ex vivo chicken livers in a water bath. Finally, the livers of 4 live swine underwent up to 6 CEUS-guided treatments using parameters optimized from in vitro work. RESULTS: Treatment of the phantom between 20-60s, produced ablation sizes from 0.016 to 0.4 cm 3 . The relationship between time and size was exponential (R 2 = 0.992). Ablation areas were also well visualized on with ultrasound imaging. The ex vivo liver ablation size at 20s was 0.37 cm 3 , at 30s was 0.66 cm 3 , and at 100 s was 5.0 cm 3 . For the in-vivo swine experiments, the average ablation area measured 2.0x0.75 cm with a maximum of 3.5x1.5 cm. CEUS was utilized with the contrast agent Definity (Lantheus) for identification of lacerations as well as immediate post operative evaluation of therapy. CONCLUSION: These experiments demonstrate the feasibility of CEUS guided transdermal HIFU ablation and the time-dependent size of ablation. This work warrants future investigations into using ultrasound to detect active bleeding and HIFU to coagulate grade III and IV liver laceration. STUDY TYPE: Therapeutic/care management.

Peer Support to Promote Surgeon Well-being: The APSA Program Experience.

BACKGROUND: Peer support programs have evolved to train physicians to provide outreach and emotional first aid to their colleagues when they experience the inevitable challenge of a serious adverse event, whether or not it is related to a medical error. Most pediatric surgeons have experienced the trauma of a medical error, yet, in a survey of APSA membership, almost half said that no one reached out to them, and few were satisfied with their institution's response to the error. Thus, the APSA Wellness Committee developed an APSA-based peer support program to meet this need. METHODS: Peer supporters were nominated by fellow APSA members, and the group was vetted to ensure diversity in demographics, practice setting, and seniority. Formal virtual training was conducted before the program went live in 2020. Trained supporters were surveyed 6 months after the program launched to evaluate their experiences with providing peer support. RESULTS: 15 referrals were made in the first year, 60 % of which were self-initiated. Most referrals were for distress related to adverse events or toxic work environments (33 % each). While only about 25 % of trained supporters had provided formal support through the APSA program, more than 80 % reported using the skills to support colleagues and trainees within their own institutions. CONCLUSION: Our experience in the first year of the APSA peer support program demonstrates the feasibility of building and maintaining a national program to provide emotional first aid by a professional society to expand the safety net for surgeons who are suffering.