Background & Aims Abdominal surgery often precipitates postoperative ileus (POI), a frequent and severe gastrointestinal (GI) motility disorder, through mechanisms that involve intestinal inflammation. Emerging data show that enteric glia acquire a reactive phenotype that aggravates POI, but how glia exert this effect remains unclear. Enteric glia express connexin-43 hemichannels (gCx43), which are implicated in neurological and inflammatory disorders. Thus, we aimed to decipher contributions of glial connexin-43 (Cx43) in the pathophysiology of POI. Methods We induced POI in mice using in vivo intestinal manipulation and used glial Cx43cKO (Sox10CreERT2;Cx43fl/fl) or RiboTag (Sox10CreERT2/Rpl22HA/+) mice to evaluate Cx43-dependent signaling. Human enteric glial cultures (hEGC) and muscularis externa obtained during intestinal surgery translated findings to patients. Transcriptome analysis, immunofluorescence co-labeling, Western blots, and Cx43 hemichannel activation were used for quantitative analysis. Results Cx43 is the highest expressed connexin in enteric glia in mice and humans. Up-regulation of Cx43 occurs in various disease models linked to POI, GI surgical trauma, inflammation, immune cell activation, and enteric gliosis. In the mouse POI model, glial Cx43-deletion reduces glial reactivity, pro-inflammatory signals, upregulates host protection genes, regulates immune cell activation, and prevents enteric neuropathy. In hEGCs, interleukin (IL)-1β induction opens Cx43 and stimulates release of IL-6 and C-C motif ligand 2 (CCL2). The Cx43 peptide inhibitor, 43Gap26, inhibits glial Cx43 activation, reduces IL-6 release, and blocks upregulation of macrophage activation factors and immune cell regulation factors. Surgical intestinal trauma in patients upregulates Cx43 during inflammation and enteric gliosis in mouse POI. Conclusions Glial Cx43 signaling promotes enteric gliosis, immune cell activation, inflammation, and enteric neuropathy in mice with potential translatability to humans after intestinal surgical trauma and mechanical stress in POI. Interventions that block glial Cx43 activation may be protective against POI development.

The Western diets (WD), high in saturated fats such as palmitic acid (PA), promotes enteric neurodegeneration and motility disorders. Using murine models, in vitro systems, and human myenteric ganglia, we investigated whether a WD and PA drive iron-dependent ferroptotic injury in the enteric nervous system (ENS). Mice were fed a control diet (CD) or a WD for 12 weeks, with or without systemic AAV9-MaCPNS2 delivery of Nfe2l2 to enteric neurons. Colonic motility was assessed by a bead expulsion assay. We assessed ferroptosis using convergent readouts including iron dysregulation (transferrin receptor 1 [TfR1], ferritin heavy chain 1 [FTH1], labile and mitochondrial iron [Fe 2+ ]), lipid peroxidation (C11-BODIPY and 4-hydroxynonenal [4-HNE]), glutathione peroxidase 4 (GPX4) suppression, and pharmacologic inhibition by ferrostatin 1 (Fer-1) in primary enteric neurons, murine myenteric plexuses, and human networks of myenteric ganglia (nhMPG). WD-fed mice exhibited delayed colonic transit, increased TfR1 and FTH1, and vulnerability of nNOS neurons; these changes were reversed by nuclear factor erythroid 2–related factor 2; (Nfe2l2, also known as Nrf2) overexpression. RNA-seq of PA-treated immortalized murine fetal enteric neurons (IM-FENs) revealed disrupted neurotransmitter signaling, reduced mitochondrial and antioxidant programs, and increased iron import and lipid peroxidation signatures. PA increased labile Fe 2+ , mitochondrial ROS, membrane depolarization, Ca 2+ dysregulation, 4-HNE, and mitoferrin 2 (Mfrn2), whereas Fer-1 preserved mitochondrial integrity, viability, and ENS function. In human nhMPG, PA induced enteric neuronal iron loading and ferroptosis, supporting the translational relevance to diet-associated enteric neuropathy.

Background The COVID-19 pandemic disrupted health care delivery, including cancer screening practices. This study sought to determine the impact of the COVID-19 pandemic lockdown on colorectal cancer (CRC) screening relative to social vulnerability. Methods Using the Medicare Standard Analytic File, individuals 65 years old or older who were eligible for guideline-concordant CRC screening between 2019 and 2021 were identified. These data were merged with the Center for Disease Control Social Vulnerability Index (SVI) dataset. Changes in county-level monthly screening volumes relative to the start of the COVID-19 pandemic (March 2020) and easing of restrictions (March 2021) were assessed relative to SVI. Results Among 10,503,180 individuals continuously enrolled in Medicare with no prior diagnosis of CRC, 1,362,457 (12.97%) underwent CRC screening between 2019 and 2021. With the COVID-19 pandemic, CRC screening decreased markedly across the United States (median monthly screening: pre-pandemic [ n = 76,444] vs pandemic era [ n = 60,826]; median Δ n = 15,618; p < 0.001). The 1-year post-pandemic overall CRC screening utilization generally rebounded to pre-COVID-19 levels (monthly median screening volumes: pandemic era [ n = 60,826] vs post-pandemic [ n = 74,170]; median Δ n = 13,344; p < 0.001). Individuals residing in counties with the highest SVI experienced a larger decline in CRC screening odds than individuals residing in low-SVI counties (reference, low SVI: pre-pandemic high SVI [OR, 0.85] vs pandemic high SVI [OR, 0.81] vs post-pandemic high SVI [OR, 0.85]; all p < 0.001). Conclusions The COVID-19 pandemic was associated with a decrease in CRC screening volumes. Patients who resided in high social vulnerability areas experienced the greatest pandemic-related decline.

We implemented a near-peer (resident–student) coaching intervention in 2021–2022 to improve clerkship students’ health system science (HSS) learning and application. This study thus sought to identify implementation barriers and potential facilitators of an effective HSS near-peer coaching program for clerkship students from the resident coach’s perspective at a single tertiary-care institution. A mixed-methods study design was employed. Thirty surgical residents volunteered to serve as HSS coaches for rotating third-year medical students during the 2021–2022 academic year. Coaches were asked to complete an exit survey, and a subset was purposefully sampled to complete semi-structured interviews. Transcripts were coded and analyzed with a framework method to identify emergent themes indicative of the barriers and facilitators of effective implementation of this near-peer HSS coaching program. A total of 20/30 (67

BACKGROUND: There is a scarcity of literature describing outcomes of reoperative Crohn's disease. An in-depth knowledge of these outcomes is critical for managing patient expectations and optimal perioperative planning. We sought to examine outcomes in patients undergoing reoperative surgeries for Crohn's disease compared to index operations. METHODS: A retrospective chart review of surgeries performed from 2018-2023 at a single tertiary care academic institution was performed. A subgroup analysis of index vs. reoperative ileocolic resections was performed to minimize confounding due to the heterogeneity of operations between the index and reoperative groups. RESULTS: Out of 119 patients, 70 (59%) underwent index operations, and 49 (41%) were reoperations. Overall com- plication rates (24.28% vs. 34.69%, P=0.224), EBL (189.5 vs. 193.4 mL, P=0.94), operative time (209 vs. 236 min, P=0.091), length of stay (mean: 7.24 vs. 10.08 days, P=0.0142), utilization of laparoscopy (92.85% vs. 65.3%, P=0.0002) and conversion to open technique (4.61% vs. 9.37%, P=0.392) favored index cases. The laparoscopic approach narrowed the gap in length of stay between the index and reoperative groups from 2.83 to 0.6 days. Subgroup analysis of ileocolic resections (Index: 50, reoperations: 26) also favored the index operations. CONCLUSIONS: The current study provides valuable insight into managing patient expectations and optimal periop- erative planning for reoperative Crohn's disease. Reoperations were associated with longer stays, lower utilization of laparoscopic platforms, and a trend toward higher overall complication rates. Laparoscopy reduces the gap in length of stay between index and reoperations; however, it is associated with a higher reoperation conversion rate.

There is no consensus on whether laparoscopic experience should be a prerequisite for robotic training. Further, there is limited information on skill transference between laparoscopic and robotic techniques. This study focused on the general surgery residents’ learning curve and skill transference within the two minimally invasive platforms. General surgery residents were observed during the performance of laparoscopic and robotic inguinal hernia repairs. The recorded data included objective measures (operative time, resident participation indicated by percent active time on console or laparoscopy relative to total case time, number of handoffs between the resident and attending), and subjective evaluations (preceptor and trainee assessments of operative performance) while controlling for case complexity, patient comorbidities, and residents’ prior operative experience. Wilcoxon two-sample tests and Pearson Correlation coefficients were used for analysis. Twenty laparoscopic and forty-four robotic cases were observed. Mean operative times were 90 min for robotic and 95 min for laparoscopic cases (P = 0.4590). Residents’ active participation time was 66

OBJECTIVEOperative coaching (OC) may facilitate improvement of surgery residents’ competencies by optimizing learning and teaching. We investigated how residents’ operative skills and prospective entrustment (PE) progress throughout the chief year in our OC program, how OC is perceived by participants, and how OC may facilitate learning and teaching.DESIGN, SETTING, AND PARTICIPANTSThis is a mixed-methods study conducted within the Ohio State University Wexner Medical Center General Surgery residency. Validated performance evaluations with procedural-specific skill, general skill (GS), step-specific guidance required (SSG) (an autonomy measure), and PE measures completed by chiefs, faculty coaches, and attending surgeons from 7/2018 to 6/2022 were reviewed. We also interviewed OC participants to understand their experience. Descriptive statistical and qualitative content analysis were applied.RESULTS441 evaluations from 147 OC cases completed by 22 chiefs, 5 faculty coaches, and 24 attendings were included. Overall, resident GS (p = 0.036), SSG (p = 0.023), and PE (p = 0.002) significantly improved throughout the year. PE significantly correlated (all p < 0.0001) with SSG (r = 0.73), followed by procedural-specific skill (r = 0.59), then GS (r = 0.57). On average, chiefs underestimated their surgical skills while attendings overestimated autonomy they permitted to residents. Chiefs, coaches, and attendings reached consensus on chiefs’ PE upon graduation. Five graduated chiefs and 5 attendings were interviewed. Chiefs described OC as effective in improving their self-regulated learning and particularly valued 3 OC elements: neutral authentic feedback, third-party real-time observation, and actionable feedback. Attendings noted OC promoted their engagement in skills assessment and teaching.ConclusionsOur findings suggest chief residents’ skills, autonomy, and PE progress steadily along their OC journey. Despite differences in residents’, coaches’, and attendings’ perceptions of skill, measures of autonomy reliably correlate with entrustment. OC promotes resident learning, faculty teaching, and assessment of resident skills, autonomy, and PE in the OR.

BACKGROUND:Inflammatory bowel disease may affect the pathogenesis and clinicopathologic course of colorectal cancer. We sought to characterize the impact of inflammatory bowel disease on outcomes after colectomy and/or proctectomy for a malignant indication. METHODS:Patients diagnosed with colorectal cancer as well as a pre-existing comorbid diagnosis of Crohn's disease or ulcerative colitis between 2018 and 2021 were identified from Medicare claims data. The postoperative textbook outcome was defined as the absence of complications, as well as no extended hospital stay, 90-day readmission, or mortality. Postdischarge disposition and expenditures were also examined. RESULTS:Among 191,684 patients with colorectal cancer, 4,770 (2.5%) had a pre-existing diagnosis of inflammatory bowel disease. Patients with inflammatory bowel disease-associated colorectal cancer were less likely to undergo surgical resection (no inflammatory bowel disease: 47.6% vs inflammatory bowel disease: 42.1%; P < .001). Among patients who did undergo colorectal surgery, individuals with inflammatory bowel disease were less likely to achieve a textbook outcome (odds ratio 0.64 [95% confidence interval 0.58-0.70]). In particular, patients with inflammatory bowel disease had higher odds of postoperative complications (odds ratio 1.24 [1.12-1.38]), extended hospital stay (odds ratio 1.41 [1.27-1.58]), and readmission within 90 days (odds ratio 1.56 [1.42-1.72]) (all P < .05). Patients with inflammatory bowel disease-associated colorectal cancer were less likely to be discharged to their home under independent care (odds ratio 0.77 [0.68-0.87]) and had 12.2% higher expenditures, which correlated with whether the patient had a postoperative textbook outcome. CONCLUSION:One in 40 patients with colorectal cancer had concomitant inflammatory bowel disease. Inflammatory bowel disease was associated with a lower probability of achieving ideal postoperative outcomes, higher postdischarge expenditure, as well as worse long-term survival after colorectal cancer resection.

BACKGROUND:Left-sided colorectal surgery demonstrates high anastomotic leak rates, with tissue ischemia thought to influence outcomes. Indocyanine green is commonly used for perfusion assessment, but evidence remains mixed for whether it reduces colorectal anastomotic leaks. Laser speckle contrast imaging provides dye-free perfusion assessment in real-time through perfusion heat maps and quantification. OBJECTIVE:This study investigates the efficacy of advanced visualization (indocyanine green versus laser speckle contrast imaging), perfusion assessment, and utility of laser speckle perfusion quantification in determining ischemic margins. DESIGN:Prospective intervention group using advanced visualization with case-matched, retrospective control group. SETTINGS:Single academic medical center. PATIENTS:Forty adult patients undergoing elective, minimally invasive, left-sided colorectal surgery. INTERVENTIONS:Intraoperative perfusion assessment using white light imaging and advanced visualization at 3 time points: T1-proximal colon after devascularization, before transection, T2-proximal/distal colon before anastomosis, and T3-completed anastomosis. MAIN OUTCOME MEASURES:Intraoperative indication of ischemic line of demarcation before resection under each visualization method, surgical decision change using advanced visualization, post hoc laser speckle perfusion quantification of colorectal tissue, and 30-day postoperative outcomes. RESULTS:Advanced visualization changed surgical decision-making in 17.5% of cases. For cases in which surgeons changed a decision, the average discordance between the line of demarcation in white light imaging and advanced visualization was 3.7 cm, compared to 0.41 cm ( p  = 0.01) for cases without decision changes. There was no statistical difference between the line of ischemic demarcation using laser speckle versus indocyanine green ( p  = 0.16). Laser speckle quantified lower perfusion values for tissues beyond the line of ischemic demarcation while suggesting an additional 1 cm of perfused tissue beyond this line. One (2.5%) anastomotic leak occurred in the intervention group. LIMITATIONS:This study was not powered to detect differences in anastomotic leak rates. CONCLUSIONS:Advanced visualization using laser speckle and indocyanine green provides valuable perfusion information that impacts surgical decision-making in minimally invasive left-sided colorectal surgeries. See Video Abstract . UTILIDAD CLNICA DE LAS IMGENES DE CONTRASTE MOTEADO CON LSER Y LA CUANTIFICACIN EN TIEMPO REAL DE LA PERFUSIN INTESTINAL EN RESECCIONES COLORRECTALES DEL LADO IZQUIERDO MNIMAMENTE INVASIVAS:ANTECEDENTES:La cirugía colorrectal del lado izquierdo demuestra altas tasas de fuga anastomótica, y se cree que la isquemia tisular influye en los resultados. El verde de indocianina se utiliza habitualmente para evaluar la perfusión, pero la evidencia sobre si reduce las fugas anastomóticas colorrectales sigue siendo contradictoria. Las imágenes de contraste moteado con láser proporcionan una evaluación de la perfusión sin colorantes en tiempo real a través de mapas de calor de perfusión y cuantificación.OBJETIVO:Este estudio investiga la eficacia de la evaluación de la perfusión mediante visualización avanzada (verde de indocianina versus imágenes de contraste moteado con láser) y la utilidad de la cuantificación de la perfusión con moteado láser para determinar los márgenes isquémicos.DISEÑO:Grupo de intervención prospectivo que utiliza visualización avanzada con un grupo de control retrospectivo de casos emparejados.LUGARES:Centro médico académico único.PACIENTES:Cuarenta pacientes adultos sometidos a cirugía colorrectal electiva, mínimamente invasiva, del lado izquierdo.INTERVENCIONES:Evaluación de la perfusión intraoperatoria mediante imágenes con luz blanca y visualización avanzada en tres puntos temporales: T1-colon proximal después de la devascularización, antes de la transección; T2-colon proximal/distal antes de la anastomosis; y T3-anastomosis completa.PRINCIPALES MEDIDAS DE VALORACIÓN:Indicación intraoperatoria de la línea de demarcación isquémica antes de la resección bajo cada método de visualización, cambio de decisión quirúrgica mediante visualización avanzada, cuantificación post-hoc de la perfusión con láser moteado del tejido colorrectal y resultados posoperatorios a los 30 días.RESULTADOS:La visualización avanzada cambió la toma de decisiones quirúrgicas en el 17,5% de los casos. Para los casos en los que los cirujanos cambiaron una decisión, la discordancia promedio entre la línea de demarcación en las imágenes con luz blanca y la visualización avanzada fue de 3,7 cm, en comparación con 0,41 cm (p = 0,01) para los casos sin cambios de decisión. No hubo diferencias estadísticas entre la línea de demarcación isquémica utilizando láser moteado versus verde de indocianina (p = 0,16). El moteado con láser cuantificó valores de perfusión más bajos para los tejidos más allá de la línea de demarcación isquémica y al mismo tiempo sugirió 1 cm adicional de tejido perfundido más allá de esta línea. Se produjo una fuga anastomótica (2,5%) en el grupo de intervención.LIMITACIONES:Este estudio no tuvo el poder estadístico suficiente para detectar diferencias en las tasas de fuga anastomótica.CONCLUSIONES:La visualización avanzada utilizando moteado láser y verde de indocianina proporciona información valiosa sobre la perfusión que impacta la toma de decisiones quirúrgicas en cirugías colorrectales mínimamente invasivas del lado izquierdo. (Traducción-Dr. Ingrid Melo).

Health systems science (HSS), known as the science of healthcare delivery, is a pillar of medical education. We conducted a needs assessment to investigate clerkship students’ learning expectations and experiences to refine the development and implementation strategy of a health systems science (HSS) curriculum without compromising local clinical workflow. An anonymous paper-based survey was distributed to all 3rd-year medical students during orientation week of the second clerkship ring of the academic year. Survey questions explored three assessment domains: learning and HSS self-efficacy, resource utilization, and career interests. Descriptive statistics and ANOVA were used to analyze the data. A total of 172/197 students (87.3

Surgical artificial intelligence (AI) has the potential to improve patient safety and clinical outcomes. To date, training such AI models to identify tissue anatomy requires annotations by expensive and rate-limiting surgical domain experts. Herein, we demonstrate and validate a methodology to obtain high quality surgical tissue annotations through crowdsourcing of non-experts, and real-time deployment of multimodal surgical anatomy AI model in colorectal surgery.

BACKGROUND:Although malnutrition has been linked to worse healthcare outcomes, the broader context of food environments has not been examined relative to surgical outcomes. We sought to define the impact of food environment on postoperative outcomes of patients undergoing resection for colorectal cancer (CRC). METHODS:Patients who underwent surgery for CRC between 2014 and 2020 were identified from the Medicare database. Patient-level data were linked to the United States Department of Agriculture data on food environment. Multivariable regression was used to examine the association between food environment and the likelihood of achieving a textbook outcome (TO). TO was defined as the absence of an extended length of stay (≥75th percentile), postoperative complications, readmission, and mortality within 90 days. RESULTS:A total of 260,813 patients from 3017 counties were included in the study. Patients from unhealthy food environments were more likely to be Black, have a higher Charlson Comorbidity Index, and reside in areas with higher social vulnerability (all P < .01). Patients residing in unhealthy food environments were less likely to achieve a TO than that of patients residing in the healthiest food environments (food swamp: 48.8% vs 52.4%; food desert: 47.9% vs 53.7%; P < .05). On multivariable analysis, individuals residing in the unhealthy food environments had lower odds of achieving a TO than those of patients living in the healthiest food environments (food swamp: OR, 0.86; 95% CI, 0.83-0.90; food desert: OR, 0.79; 95% CI, 0.76-0.82); P < .05). CONCLUSION:The surrounding food environment of patients may serve as a modifiable sociodemographic risk factor that contributes to disparities in postoperative CRC outcomes.

Supplementary fig 1 Flowchart for trial design

BACKGROUND AND PURPOSE:ET-1 signalling modulates intestinal motility and inflammation, but the role of ET-1/ETB receptor signalling is poorly understood. Enteric glia modulate normal motility and inflammation. We investigated whether glial ETB signalling regulates neural-motor pathways of intestinal motility and inflammation. EXPERIMENTAL APPROACH:We studied ETB signalling using: ETB drugs (ET-1, SaTX, BQ788), activity-dependent stimulation of neurons (high K+ -depolarization, EFS), gliotoxins, Tg (Ednrb-EGFP)EP59Gsat/Mmucd mice, cell-specific mRNA in Sox10CreERT2 ;Rpl22-HAflx or ChATCre ;Rpl22-HAflx mice, Sox10CreERT2 ::GCaMP5g-tdT, Wnt1Cre2 ::GCaMP5g-tdT mice, muscle tension recordings, fluid-induced peristalsis, ET-1 expression, qPCR, western blots, 3-D LSM-immunofluorescence co-labelling studies in LMMP-CM and a postoperative ileus (POI) model of intestinal inflammation. KEY RESULTS:In the muscularis externa ETB receptor is expressed exclusively in glia. ET-1 is expressed in RiboTag (ChAT)-neurons, isolated ganglia and intra-ganglionic varicose-nerve fibres co-labelled with peripherin or SP. ET-1 release provides activity-dependent glial ETB receptor modulation of Ca2+ waves in neural evoked glial responses. BQ788 reveals amplification of glial and neuronal Ca2+ responses and excitatory cholinergic contractions, sensitive to L-NAME. Gliotoxins disrupt SaTX-induced glial-Ca2+ waves and prevent BQ788 amplification of contractions. The ETB receptor is linked to inhibition of contractions and peristalsis. Inflammation causes glial ETB up-regulation, SaTX-hypersensitivity and glial amplification of ETB signalling. In vivo BQ788 (i.p., 1 mg·kg-1 ) attenuates intestinal inflammation in POI. CONCLUSION AND IMPLICATIONS:Enteric glial ET-1/ETB signalling provides dual modulation of neural-motor circuits to inhibit motility. It inhibits excitatory cholinergic and stimulates inhibitory nitrergic motor pathways. Amplification of glial ETB receptors is linked to muscularis externa inflammation and possibly pathogenic mechanisms of POI.