In vivo CRISPR screens reveal the landscape of immune evasion pathways across cancer.

The immune system can eliminate tumors, but checkpoints enable immune escape. Here, we identify immune evasion mechanisms using genome-scale in vivo CRISPR screens across cancer models treated with immune checkpoint blockade (ICB). We identify immune evasion genes and important immune inhibitory checkpoints conserved across cancers, including the non-classical major histocompatibility complex class I (MHC class I) molecule Qa-1b/HLA-E. Surprisingly, loss of tumor interferon-γ (IFNγ) signaling sensitizes many models to immunity. The immune inhibitory effects of tumor IFN sensing are mediated through two mechanisms. First, tumor upregulation of classical MHC class I inhibits natural killer cells. Second, IFN-induced expression of Qa-1b inhibits CD8+ T cells via the NKG2A/CD94 receptor, which is induced by ICB. Finally, we show that strong IFN signatures are associated with poor response to ICB in individuals with renal cell carcinoma or melanoma. This study reveals that IFN-mediated upregulation of classical and non-classical MHC class I inhibitory checkpoints can facilitate immune escape.

In vivo screens using a selective CRISPR antigen removal lentiviral vector system reveal immune dependencies in renal cell carcinoma.

CRISPR-Cas9 genome engineering has increased the pace of discovery for immunology and cancer biology, revealing potential therapeutic targets and providing insight into mechanisms underlying resistance to immunotherapy. However, endogenous immune recognition of Cas9 has limited the applicability of CRISPR technologies in vivo. Here, we characterized immune responses against Cas9 and other expressed CRISPR vector components that cause antigen-specific tumor rejection in several mouse cancer models. To avoid unwanted immune recognition, we designed a lentiviral vector system that allowed selective CRISPR antigen removal (SCAR) from tumor cells. The SCAR system reversed immune-mediated rejection of CRISPR-modified tumor cells in vivo and enabled high-throughput genetic screens in previously intractable models. A pooled in vivo screen using SCAR in a CRISPR-antigen-sensitive renal cell carcinoma revealed resistance pathways associated with autophagy and major histocompatibility complex class I (MHC class I) expression. Thus, SCAR presents a resource that enables CRISPR-based studies of tumor-immune interactions and prevents unwanted immune recognition of genetically engineered cells, with implications for clinical applications.

Healing Exposed Calvarial Hardware Using Negative-Pressure Wound Therapy and Vashe Wound Solution: Case Report.

OBJECTIVE: The management of cranioplasty infections has historically been explantation followed by delayed reimplantation/reconstruction. This treatment algorithm necessitates surgery, tissue expansion, and prolonged disfigurement. In this report, the authors describe a treatment approach consisting of serial vacuum-assisted closure (VAC) with hypochlorous acid (HOCl) solution (Vashe Wound Solution; URGO Medical) as a salvage strategy. METHODS: A 35-year-old man who sustained head trauma, neurosurgical complications, and severe syndrome of the trephined (SOT; devastating neurologic decline treated by cranioplasty) underwent titanium cranioplasty with free flap. Three weeks postoperation, he presented with pressure-related wound dehiscence/partial flap necrosis, exposed hardware, and bacterial infection. Given the severity of his precranioplasty SOT, hardware salvage was critical. He was treated with serial VAC with HOCl solution for 11 days followed by VAC for 18 days and definitive split-thickness skin graft placement over resulting granulation tissue. Authors also conducted a literature review of cranial reconstruction infection management. RESULTS: The patient remained healed 7 months postoperatively without recurrent infection. Importantly, his original hardware was retained, and his SOT remained resolved. Findings from the literature review support the use of conservative modalities to salvage cranial reconstructions without hardware removal. CONCLUSIONS: This study investigates a new strategy for managing cranioplasty infections. The VAC with HOCl solution regimen was effective in treating the infection and salvaging the cranioplasty, thus obviating the complications associated with explantation, new cranioplasty, and recurrence of SOT. There is limited literature on the management of cranioplasty infections using conservative treatments. A larger study to better determine the efficacy of VAC with HOCl solution is underway.

Protective Effects of Authenticity Against Depression, Suicide, and Burnout among Surgeons.

BACKGROUND: Physician burnout and poor mental health are highly prevalent issues within the surgical community. Authenticity, defined as the degree to which individuals align their actions with their true selves, has been identified as a potential factor facilitating positive mental health. This study explores the impact of authenticity on burnout, depression, and suicide among surgeons. STUDY DESIGN: Members of the department of surgery at a large academic medical center were sent an anonymous survey between April to May 2023. The survey evaluated authenticity using Authenticity Scale, depression using Patient Health Questionnaire (PHQ9), burnout using Copenhagen Burnout Inventory, and suicidality using Ask-Suicide Screening Questions (ASQ) tool. RESULTS: Of the 170 surgeons, 94 (55.3%) completed the survey. Higher Authentic Living scores (ALS) correlated with reduced burnout (r=-0.21, p=0.047) and depression (r=-0.37, p=0.0002). Conversely, higher Accepting External Influence (AEI) were associated with increased depression (r=0.23, p=0.023) and higher Self-Alienation (ASA) were associated with increased burnout (r=0.43, p<0.0001) and depression (r=0.48, p<0.0001). While authenticity domain scores were not significantly associated with ASQ, specific AEI and ASA questions indicated an elevated odds ratio (p=0.029 and p=0.010 respectively) of a positive ASQ. ALS increased with advancement in professional rank (p=0.007), while AEI (p=0.0001), ASA (p=0.003), depression (p=0.014), and ASQ (p=0.02) decreased. CONCLUSIONS: In this study, higher authenticity was associated with a lower likelihood of burnout and depression among surgeons. This study contributes valuable insights into the development of targeted intervention and support mechanisms aimed at promoting authenticity and mental health within the surgical profession.

Closed Incision Negative Pressure Therapy in Oncoplastic Surgery Prevents Delays to Adjuvant Therapy.

Breast reductions, including oncoplastic breast surgery (OBS), have high postoperative wound healing complication (WHC) rates, ranging from 17% to 63%, thus posing a potential delay in the onset of adjuvant therapy. Incision management with closed incision negative pressure therapy (ciNPT) effectively reduces postoperative complications in other indications. This retrospective analysis compares postoperative outcomes and delays in adjuvant therapy in patients who received ciNPT on the cancer breast versus standard of care (SOC) after oncoplastic breast reduction and mastopexy post lumpectomy. Methods: Patient demographics, ciNPT use, postoperative complication rates, and time to adjuvant therapy were analyzed from the records of 150 patients (ciNPT = 29, SOC = 121). Propensity score matching was used to match patients based on age, body mass index, diabetes, tobacco use, and prior breast surgery. Results: In the matched cohort, the overall complication rate of ciNPT-treated cancerous breasts was 10.3% (3/29) compared with 31% (9/29) in SOC-treated cancerous breasts (P = 0.096). Compared with the SOC-treated cancerous breasts, the ciNPT breasts had lower skin necrosis rates [1/29 (3.4%) versus 6/29 (20.7%); P = 0.091] and dehiscence rates [0/29 (0%) versus 8/29 (27.6%); P = 0.004]. In the unmatched cohort, the total number of ciNPT patients who had a delay in adjuvant therapy was lower compared to the SOC group (0% versus 22.5%, respectively; P = 0.007). Conclusion: Use of ciNPT following oncoplastic breast reduction effectively lowered postoperative wound healing complication rates and, most importantly, decreased delays to adjuvant therapy.

Comparison of Aesthetic Outcomes of Epidermal Staples vs Sutures in Deep Epigastric Perforator Flap Breast Reconstruction.

Background: A secondary benefit of abdominally based autologous breast reconstruction may be improving the abdominal contour; however, poor scaring can lead to aesthetic dissatisfaction and complications. Although studies have demonstrated favorable aesthetic results and decreased operative time using dermal or subcuticular stapling (Insorb), no reports exist regarding epidermal stapling. Objectives: The aim of this study is to compare the aesthetic abdominal scar outcomes, closure time, and postoperative complications of abdominally based breast reconstruction patients who have undergone suture closure vs epidermal staple closure. Methods: A total of 217 patients who underwent abdominally based autologous breast reconstruction from 2011 to 2022 were included and retrospectively analyzed (staples = 41, suture = 176). Twenty-four patients' postoperative abdominal scar photographs were randomly chosen (staples = 12, sutures = 12) and assessed by 3 board-certified plastic surgeons using a modified patient observer scar assessment scale (POSAS) and visual analog scale (VAS). Closure time (minutes per centimeter) using staples or sutures was also analyzed. Results: The assessment of abdominal scars closed by epidermal staples revealed significant improvements in thickness (P = .033), relief (P = .033), surface area (P = .017), overall opinion (P = .033), POSAS score (P = .034), and VAS scar score (P = .023) in comparison with scars closed by sutures. Closing the abdominal wound with staples was significantly faster than closing with sutures (P < .0001). Staple and suture closure had similar postoperative complication rates. Conclusions: Abdominal donor-site scar quality may be superior and faster using the epidermal staple compared to traditional suture closure.

The Incidence of Retained Objects in Intraoperative X-rays for Missing Counts in Plastic Surgery: We Should Do Better.

Background: In the event of incorrect surgical counts, obtaining X-rays to rule out retained surgical items (RSI) is standard practice. However, these safeguards also carry risk. This study investigates the actual incidence of RSI in plastic reconstructive surgery (PRS) cases as measured on intraoperative X-rays and its associated modifiable risk factors. Methods: X-rays with indication of "foreign body" in PRS procedures from 2012 to 2022 were obtained. Reports with "incorrect surgical counts" and associated perioperative records were retrospectively analyzed to determine the incidence of retained surgical items. Results: Among 257 X-rays, 21.4% indicated incorrect counts during PRS operations. None were positive for RSIs. The average number of staff present was 12.01. This correlated to an average of 6.98 staff turnovers. The average case lasted 8.42 hours. X-rays prolonged the time under anesthesia by an average of 24.3 minutes. Free flap surgery had 49.1% prevalence of missing counts (lower extremity 25.5%, breast 20%, craniofacial 3.6%), followed by hand (14.5%), breast (10.9%), abdominal reconstruction (10.9%), craniofacial (9.1%), and cosmetic (5.4%). Conclusions: Although X-rays for incorrect counts intend to prevent catastrophic sequela of inadvertent RSIs, our results suggest the true incidence of RSI in PRS is negligible. However, intraoperative X-rays have potentially detrimental and pervasive consequences for patients, including increased anesthesia time, radiation exposure, and higher overall cost. Addressing modifiable risk factors to minimize unnecessary intraoperative X-rays is imperative while also considering whether this modality is an effective and appropriate tool in PRS procedures with incorrect surgical counts.