Modern trends in minimally invasive versus open hepatectomy for colorectal liver metastasis: an analysis of ACS-NSQIP.

BACKGROUND: Surgical resection of colorectal liver metastasis (CRLM) provides the best opportunity for prolonged survival. Eligibility for metastasectomy has expanded with technical advancements including parenchymal-sparing hepatectomy (PSH). Meanwhile, enthusiasm for minimally invasive surgery (MIS) has increased, though this approach may be preferentially utilized for technically straightforward cases. The purpose of this study is to characterize modern trends in open versus MIS approaches to partial hepatectomy and anatomic hepatectomy for CRLM within a nationwide cohort. METHODS: The American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) was used to investigate trends in MIS versus open hepatectomy for CRLM from 2015 to 2019. We examined baseline clinicopathologic and disease-related characteristics and compared trends in treatments over the study period. RESULTS: A total of 7457 patients undergoing hepatectomy for CRLM were identified (1367 MIS, 6090 open). Patients had similar clinicopathologic features between the two groups. Patients undergoing MIS resection less frequently received neoadjuvant therapy (51.1% vs 64.0%, p < 0.001) or concurrent intraoperative ablation (15.0% vs 21.3%, p < 0.001). Patients with tumors < 2 cm (34.9% vs 26.8%, p < 0.001) or only one to two tumors (82.8% vs 65.0%, p < 0.001) more commonly underwent MIS. MIS and open partial hepatectomies both significantly increased over the study period, but open partial hepatectomy increased at a greater rate than MIS (p < 0.001). Rates of anatomic resections have remained the same, with a greater proportion performed using an open approach (34.9% vs 16.4%, p < 0.001). Rates of operations consisting of > 1 concurrent partial hepatectomy are stable, but significantly more likely to be performed open (p < 0.001). CONCLUSIONS: Hepatectomy for CRLM has increased from a rise in partial hepatectomy, potentially translating to increased use of PSH. Current trends suggest MIS approaches appear to be increasing, but selectively implemented for patients with less technically demanding disease characteristics. Educational efforts should be directed towards increased dissemination of parenchymal-sparing MIS techniques for more complex resections.

Using the Flipped Classroom Model in Surgical Education: Efficacy and Trainee Perception.

OBJECTIVE: To describe the feasibility, efficacy, and learner perception of the flipped classroom model for teaching conferences within surgical training programs. DESIGN: For the flipped classroom conferences, video lectures were prepared by a faculty member, and sent to all attendees at least 2 days prior to lecture. The conference time was then spent going over cases and questions, rather than traditional lecture. We conducted a qualitative survey to assess learner's perceptions and pre-lecture quizzes to assess trainee preparedness. SETTING: The comparison of pre-conference quizzes between flipped classroom and traditional models was carried out at Brooke Army Medical Center (BAMC) in San Antonio, TX, a tertiary care facility with a general surgery residency program. The survey was conducted at BAMC and within the Complex General Surgical Oncology fellowship program at University of Texas MD Anderson Cancer Center, where a flipped classroom model was similarly employed. PARTICIPANTS: Surgical residents BAMC participated in pre-lecture quizzes. BAMC residents and MD Anderson fellows were invited to complete the online survey. RESULTS: Lecture videos did not increase mean preparation time (1.53 vs. 1.46 hours without vs. with video, p = 0.858), but did increase mean quiz scores from 67% to 80% (p = 0.031) with 32/35 learners utilizing videos. Videos increased the proportion of learners who self-reported preparing at all from 42% to 95% (p = 0.28), and preparing for at least one hour for conference from 23% to 49% (p = 0.014). Of survey respondents, 90% said videos were very helpful, 90% would use them weekly if available, and 90% prefer this format to traditional lecture. CONCLUSIONS: Utilization of a flipped classroom method was well received and preferred by surgical trainees, and it increased performance on pre-conference quizzes without increasing preparation time. Although creation of video lectures is work-intensive for lecturers, these results suggest it is more effective for learner preparation. These results could be generalizable to surgical residents nationwide as technology utilization increases in surgical education.

Evaluation of Attenuated Tumor Antigens and the Implications for Peptide-Based Cancer Vaccine Development.

INTRODUCTION: Peptide vaccines offer anti-tumor efficacy with very low toxicity. However, repeat stimulation with an immunogenic peptide leads to activation induced cell death (AICD), decreasing efficacy. We engineered variants of an immunogenic peptide (E39) and tested their ability to induce a robust, sustainable immune response. METHODS: Multiple variants of E39 were created by exchanging 1 or 2 amino acids. We tested the PBMC proliferation, cytokine production and cytolytic activity induced by each variant peptide. RESULTS: Repeated stimulation with E39 likely led to in vitro AICD, while stimulation with E39' led to T-cell proliferation with less evidence of AICD, modest cytokine production and high CTL activity. CONCLUSIONS: E39' appears to be the optimal variant of E39 for inducing effective long-term immunity.

Gaining ground on a cure through synergy: combining checkpoint inhibitors with cancer vaccines.

INTRODUCTION: The approval of multiple checkpoint inhibitors (CPIs) for the treatment of advanced malignancies has sparked an explosion of research in the field of cancer immunotherapy. Despite the success of these medications, a large number of patients with advanced malignancy do not benefit from therapy. Early research indicates that a therapeutic combination of cancer vaccines with checkpoint inhibitors may lead to synergistic effects and higher response rates than monotherapy. Areas covered: This paper summarizes the previously completed and ongoing research on this exciting combination, including the use of the tumor lysate, particle-loaded dendritic cell (TLPLDC) vaccine combined with checkpoint inhibitors in advanced melanoma. Expert commentary: Increasing experience with CPIs has led to improved understanding of which patients may benefit and it is increasingly clear that the presence of a pre-existing immune response to the tumor, along with tumor-infiltrating lymphocytes, is key to the success of CPIs. One exciting possibility for the future is the addition of a cancer vaccine to CPI therapy, eliciting these crucial T cells, which can then be augmented and protected by the CPI. A number of current and future studies are addressing this very exciting combination therapy.