A Propensity Score-Matched Analysis of the Impact of Neoadjuvant Radiation Therapy on the Outcomes of Stage II and III Mucinous Rectal Carcinoma.

BACKGROUND: Patients with mucinous rectal carcinoma tend to present in advanced stage with a poor prognosis. OBJECTIVE: This study aimed to assess the effect of neoadjuvant radiation therapy on outcomes of patients with stage II and III mucinous rectal carcinomas using data from the National Cancer Database. DESIGN: Retrospective analysis of prospective national databases. SETTING: National Cancer Database between 2004 and 2019. PATIENTS: Patients with mucinous rectal carcinoma. INTERVENTION: Patients who did or did not receive neoadjuvant radiation therapy were matched using the nearest-neighbor propensity score method for age, clinical stage, neoadjuvant systemic treatment, and surgery type. MAIN OUTCOME MEASURES: Main outcomes of the study were numbers of total harvested and positive lymph nodes, disease downstaging after neoadjuvant radiation, and overall survival. Other outcomes were hospital stay, short-term mortality, and readmission. RESULTS: A total of 3062 patients (63.5% men) with stage II and III mucinous rectal carcinoma were included, 2378 of whom (77.7%) received neoadjuvant radiation therapy. After 2:1 propensity score matching, 143 patients in the no neoadjuvant group were matched to 286 patients in the neoadjuvant group. The mean overall survival was similar (77.3 vs 81.9 months; p = 0.316). Patients who received neoadjuvant radiation therapy were less often diagnosed with pathologic T3 and 4 disease (72.3% vs 81.3%, p = 0.013) and more often had pathologic stage 0 and 1 disease (16.4% vs 11.2%, p = 0.001), yet with a higher stage III disease (49.7% vs 37.1%, p = 0.001). Neoadjuvant radiation was associated with fewer examined lymph nodes (median: 14 vs 16, p = 0.036) and positive lymph nodes than patients who did not receive neoadjuvant radiation. Short-term mortality, readmission, hospital stay, and positive surgical margins were similar. LIMITATIONS: Retrospective study and missing data on disease recurrence. CONCLUSIONS: Patients with mucinous rectal carcinoma who received neoadjuvant radiation therapy had marginal downstaging of disease, fewer examined and fewer positive lymph nodes, and similar overall survival to patients who did not receive neoadjuvant radiation. See Video Abstract . UN ANLISIS EMPAREJADO POR PUNTUACIN DE PROPENSIN DEL IMPACTO DE LA RADIOTERAPIA NEOADYUVANTE EN LOS RESULTADOS DEL CARCINOMA MUCINOSO DE RECTO EN ESTADIO IIIII: ANTECEDENTES:Los pacientes con carcinoma mucinoso de recto tienden a presentarse en estadio avanzado con mal pronóstico.OBJETIVO:Este estudio tuvo como objetivo evaluar el efecto de la radioterapia neoadyuvante en los resultados de pacientes con carcinomas mucinosos de recto en estadio II-III utilizando datos de la Base de Datos Nacional del Cáncer.DISEÑO:Análisis retrospectivo de bases de datos nacionales prospectivas.PACIENTES:Pacientes con carcinoma mucinoso de recto.AJUSTE:Base de datos nacional sobre el cáncer entre 2004 y 2019.INTERVENCIÓN:Los pacientes que recibieron o no radioterapia neoadyuvante fueron emparejados utilizando el método de puntuación de propensión del vecino más cercano por edad, estadio clínico, tratamiento sistémico neoadyuvante y tipo de cirugía.PRINCIPALES MEDIDAS DE VALORACIÓN:Los principales resultados del estudio fueron el número total de ganglios linfáticos extraídos y positivos, la reducción del estadio de la enfermedad después de la radiación neoadyuvante y la supervivencia general. Otros resultados fueron la estancia hospitalaria, la mortalidad a corto plazo y el reingreso.RESULTADOS:Se incluyeron 3.062 pacientes (63,5% hombres) con carcinoma mucinoso de recto estadio II-III, de los cuales 2.378 (77,7%) recibieron radioterapia neoadyuvante. Después de un emparejamiento por puntuación de propensión 2:1, 143 pacientes del grupo sin neoadyuvancia fueron emparejados con 286 del grupo neoadyuvante. La supervivencia global media fue similar (77,3 vs 81,9 meses; p = 0,316). A los pacientes que recibieron radiación neoadyuvante se les diagnosticó con menos frecuencia enfermedad pT3-4 (72,3% frente a 81,3%, p = 0,013) y con mayor frecuencia tenían enfermedad en estadio patológico 0-1 (16,4% frente a 11,2%, p = 0,001), aunque con una enfermedad en estadio III superior (49,7% vs 37,1%, p = 0,001). La radiación neoadyuvante se asoció con menos ganglios linfáticos examinados (mediana: 14 frente a 16, p = 0,036) y ganglios linfáticos positivos que los pacientes que no recibieron radiación neoadyuvante. La mortalidad a corto plazo, el reingreso, la estancia hospitalaria y los márgenes quirúrgicos positivos fueron similares.LIMITACIONES:Estudio retrospectivo y datos faltantes sobre recurrencia de la enfermedad.CONCLUSIONES:Los pacientes con carcinoma mucinoso de recto que recibieron radioterapia neoadyuvante tuvieron una reducción marginal de la enfermedad, menos ganglios linfáticos examinados y positivos, y una supervivencia general similar a la de los pacientes que no recibieron radiación neoadyuvante. (Traducción- Dr Ingrid Melo ).

Meta-analysis of Randomized Clinical Trials on Long-term Outcomes of Surgical Treatment of Perforated Diverticulitis.

OBJECTIVE: To assess long-term outcomes of patients with perforated diverticulitis treated with resection or laparoscopic lavage (LL). BACKGROUND: Surgical treatment of perforated diverticulitis has changed in the last few decades. LL and increasing evidence that primary anastomosis (PRA) is feasible in certain patients have broadened surgical options. However, debate about the optimal surgical strategy lingers. METHODS: PubMed, Scopus, and Web of Science were searched for randomized clinical trials (RCT) on surgical treatment of perforated diverticulitis from inception to October 2022. Long-term reports of RCT comparing surgical interventions for the treatment of perforated diverticulitis were selected. The main outcome measures were long-term ostomy, long-term complications, recurrence, and reintervention rates. RESULTS: After screening 2431 studies, 5 long-term follow-up studies of RCT comprising 499 patients were included. Three studies, excluding patients with fecal peritonitis, compared LL and colonic resection, and 2 compared PRA and Hartmann procedures. LL had lower odds of long-term ostomy [odds ratio (OR) = 0.133, 95% CI: 0.278-0.579; P < 0.001] and reoperation (OR = 0.585, 95% CI: 0.365-0.937; P = 0.02) compared with colonic resection but higher odds of diverticular disease recurrence (OR = 5.8, 95% CI: 2.33-14.42; P < 0.001). Colonic resection with PRA had lower odds of long-term ostomy (OR = 0.02, 95% CI: 0.003-0.195; P < 0.001), long-term complications (OR = 0.195, 95% CI: 0.113-0.335; P < 0.001), reoperation (OR = 0.2, 95% CI: 0.108-0.384; P < 0.001), and incisional hernia (OR = 0.184, 95% CI: 0.102-0.333; P < 0.001). There was no significant difference in odds of mortality among the procedures. CONCLUSIONS: Long-term follow-up of patients who underwent emergency surgery for perforated diverticulitis showed that LL had lower odds of long-term ostomy and reoperation, but more risk for disease recurrence when compared with resection in purulent peritonitis. Colonic resection with PRA had better long-term outcomes than the Hartmann procedure for fecal peritonitis.

Outcomes of laparoscopic versus robotic-assisted resection of T4 rectal cancer: propensity score-matched analysis of a national cancer database.

BACKGROUND: T4 rectal cancer is a challenging condition owing to the highly invasive nature of the tumour that may compromise R0 resection. The present study aimed to assess the outcomes of laparoscopic versus robotic-assisted resection of non-metastatic T4 rectal adenocarcinoma. METHODS: This was a retrospective propensity score-matched analysis using the National Cancer Database between 2010 and 2019. Patients with pathological T4 non-metastatic rectal adenocarcinoma who underwent laparoscopic or robotic-assisted resection were compared and a propensity score-matched analysis was performed in a 1:1 manner. The main outcome measures were conversion to open surgery, mortality, readmission, resection margins, and overall survival. RESULTS: After propensity score matching, 235 patients were included in each group. There were 260 (55.3 per cent) men and 210 (44.7 per cent) women, with a mean (s.d.) age of 61 (13.2) years. Patients in the robotic group had a statistically significantly lower conversion rate (8.9 per cent versus 17.9 per cent; P = 0.006), shorter median duration of hospital stay (5 versus 6 days; P = 0.007), higher overall survival rate (56.2 per cent versus 43.4 per cent; P = 0.007), and a longer median survival (60.8 versus 43.2; P = 0.025). There were no significant differences between the two groups with regard to positive resection margins, examined lymph nodes, 30-day and 90-day mortality rates, and 30-day readmission rate. CONCLUSIONS: Robotic resections of T4 rectal cancer were associated with a significantly lower conversion rate and shorter duration of hospital stay than laparoscopic resections. The two approaches were comparable with regard to positive resection margins, short-term mortality, and readmission.

Does Completeness of the Mesorectal Excision Still Correlate With Local Recurrence?

BACKGROUND: Total mesorectal excision is the standard surgical procedure for rectal cancer treatment. Several studies have shown a close correlation between the prognosis of patients with rectal cancer and the completeness of the mesorectal specimen. OBJECTIVE: To assess the correlation between macroscopic assessment of mesorectal excision and long-term oncological outcomes. DESIGN: Retrospective analysis of an Institutional Review Board-approved database. SETTINGS: Tertiary referral center. PATIENTS: Patients with rectal cancer who were operated on between March 2016 and October 2019 were classified into 3 groups based on the mesorectal specimen quality: complete, near complete, and incomplete. Only patients with a follow-up of ≥2 years and without signs of preoperative distant disease were included. MAIN OUTCOME MEASURES: Relationship between total mesorectal excision and local and distant recurrence rates in patients with rectal cancer. RESULTS: A total of 124 patients (35.5% females) were included in the analysis, with a mean age of 58.1 (SD 12) years and a mean BMI of 26.4 (SD 4.59) kg/m². Neoadjuvant chemoradiation was administered to 71% of patients, whereas 13.7% received total neoadjuvant therapy. Restorative procedures were performed in 107 patients (86.3%), whereas 17 patients (13.7%) underwent abdominoperineal resection. The majority of mesorectal excision specimens (87.09%) were complete or near complete. Local recurrence rates were 6.3% (1/16) in the incomplete and 7.4% (8/108) in the complete/near complete group ( p = 0.86). Metachronous distant metastases occurred in 6 patients (37.5%) in the incomplete group and in 24 patients (22.2%) in the complete/near complete group (p = 0.18). Thus, specimen quality did not appear to impact disease-free survival. LIMITATIONS: Retrospective, single-center study with relatively short follow-up. CONCLUSIONS: In the era of a multidisciplinary approach and extensive use of neoadjuvant therapy, macroscopic completeness of total mesorectal excision may not be as valuable a prognosticator as in the past. Larger studies with longer follow-ups are needed to clarify these preliminary findings. See Video Abstract at http://links.lww.com/DCR/C129. LA INTEGRIDAD DE LA ESCISIN MESORRECTAL TODAVA SE CORRELACIONA CON LA RECURRENCIA LOCAL: ANTECEDENTES:La escisión total desl mesorrecto es el estándar de oro para el tratamiento del cáncer de recto. Varios estudios han demostrado una estrecha correlación entre el pronóstico de los pacientes con cáncer de recto y la integridad espécimen mesorrectal.OBJETIVO:Evaluar la correlación entre la evaluación macroscópica de la escisión mesorrectal y los resultados oncológicos a largo plazo en pacientes con cáncer de recto.DISEÑO:Análisis retrospectivo de una base de datos aprobada por el IRB.ENTORNO CLINICO:El estudio se realizó en un centro de referencia terciario de una sola institución.PACIENTES:Todos los pacientes con cáncer de recto operados entre 3/2016-10/2019. Los pacientes se clasificaron en 3 grupos, según la calidad del espécimen mesorrectal: completo, casi completo e incompleto. Solo se incluyeron pacientes con seguimiento >2 años y sin signos de enfermedad a distancia preoperatoria.PRINCIPALES MEDIDAS DE RESULTADO:Identificar la relación entre la escisión mesorrectal total y las tasas de recurrencia local y a distancia en pacientes con cáncer de recto.RESULTADOS:Se incluyeron 124 pacientes (35,5% mujeres) con una edad media de 58,1 años (DE 12) y un índice de masa corporal medio de 26,4 (DE 4,59). Se administró quimiorradiación neoadyuvante al 71% de los pacientes, mientras que el 13,7% recibió terapia neoadyuvante total. Se realizaron procedimientos de restauración en 107 pacientes (86,3%), mientras que 17 pacientes (13,7%) se sometieron a resección abdominoperineal. La mayoría (87,09%) de los especímenes de escisión mesorrectal fueron completas o casi completas. Las tasas de recurrencia local fueron 1/16 (6,3%) en el grupo incompleto y 8/108 (7,4%) en el grupo completo/casi completo ( p = 0,86). Se produjeron metástasis a distancia metacrónicas en 6 pacientes (37,5%) en el grupo incompleto y 24 (22,2%) en el grupo completo/casi completo ( p = 0,18). Por lo tanto, la calidad del espécimen no pareció afectar la supervivencia libre de enfermedad.LIMITACIONES:Estudio retrospectivo de un solo centro con pequeño número de casos y seguimiento relativamente corto.CONCLUSIÓN:En la era de un enfoque multidisciplinario y el uso extensivo de la terapia neoadyuvante, la integridad macroscópica de la escisión total del mesorrecto, puede no ser un pronóstico tan valioso como en el pasado. Se necesitan estudios más amplios con períodos de seguimiento más prolongados para aclarar estos hallazgos preliminares. Consulte Video Resumen en http://links.lww.com/DCR/C129 . (Traducción-Dr. Fidel Ruiz Healy ).

The effect of mechanical bowel preparation on postoperative complications in laparoscopic right colectomy: a retrospective propensity score matching analysis.

PURPOSE: To assess whether full bowel preparation affects 30-day surgical outcomes in laparoscopic right colectomy for colon cancer. METHODS: A retrospective chart review of all elective laparoscopic right colectomies performed for colonic adenocarcinoma between Jan 2011 and Dec 2021. The cohort was divided into two groups-no bowel preparation (NP) group and patients who received full bowel preparation (FP), including oral and mechanical cathartic bowel preparation. All anastomoses were extracorporeal stapled side-to-side. The two groups were compared at baseline and then were matched using propensity score based on demographic and clinical parameters. The primary outcome was 30-day postoperative complication rate, mainly anastomotic leak (AL) and surgical site infection (SSI) rate. RESULTS: The original cohort included 238 patients with a median age of 68 (SD 13) and equal M:F ratio. Following propensity score matching, 93 matched patients were included in each group. Analysis of the matched cohort showed a significantly higher overall complication rate in the FP group (28 vs 11.8%, p = 0.005) which was mostly due to minor type II complications. There were no differences in major complication rates, SSI, ileus, or AL rate. Although operative time was significantly longer in the FP group (119 vs 100 min, p ≤ 0.001), length of stay was significantly shorter in the FP group (5 vs 6 days, p = 0.001). CONCLUSIONS: Aside from a shorter hospital stay, full mechanical bowel preparation for laparoscopic right colectomy does not seem to have any benefit and may be associated with a higher overall complication rate.

Immunotherapy in rectal cancer patients-a propensity score matched analysis of the National Cancer Database.

BACKGROUND: Rectal cancer patients with microsatellite instability (MSI-H) are candidates for immunotherapy. However, there is little evidence on its effect on overall survival (OS). METHODS: Retrospective analysis of stage II-IV rectal adenocarcinoma patients in the National Cancer Database (NCDB) between 2010 and 2019. Propensity score matching was adjusted for baseline and treatment confounders. The cohort was divided into patients who received immunotherapy and matched controls. The primary outcome was OS. RESULTS: 5175/206,615 (2.5%) patients with rectal adenocarcinoma underwent immunotherapy. These patients were younger (58 vs 62 years; p < 0.001), more often male (64.4% vs 61.7%; p < 0.001), were more likely to have private insurance (50.8% vs 43.4%; p < 0.001), more metastatic disease at presentation (clinical TNM stage IV-80.8% vs 23.3%; p < 0.001), presented with larger tumors (median: 5 cm vs. 4.2 cm; p < 0.001) and less often underwent surgery (33.7% vs. 69.9%; p < 0.001), radiation therapy (21.5% vs 57.4%; p < 0.001), and standard chemotherapy (38.1% vs 61%; p < 0.001) than controls. After matching, 488 patients were in each group. OS was significantly shorter in the immunotherapy group (mean survival: 56.4 months (95% CI: -53.03-59.86)) compared to controls (mean survival: 70.5 months (95% CI: -66.15-74.92) (p = 0.004)). Cox regression analysis of factors associated with OS demonstrated that immunotherapy was associated with increased mortality (HR 2.16; 95% CI: 2.09-2.24; p < 0.001). After clinical staging stratification, immunotherapy was associated with improved OS in stage IV (HR 0.91, 95% CI: 0.88-0.95; p < 0.001) but lower survival in stage II (HR 2.38; 95% CI: 2.05-2.77; p < 0.001) and stage III (HR 2.43; 95% CI: 2.18-2.7; p < 0.001) patients. CONCLUSION: Immunotherapy showed modest increase in OS in stage IV metastatic rectal cancer. OS was significantly lower in stage II-III disease treated with immunotherapy.

Can preoperative CT/MR enterography preclude the development of Crohn's disease-like pouch complications in ulcerative colitis patients undergoing J pouch surgery?

AIM: We aimed to determine whether ulcerative colitis patients with preoperative negative computed tomography or magnetic resonance enterography (CTE/MRE) were less likely to develop Crohn's disease-like pouch complications (CDLPC) and establish risk factors and predictors for developing CDLPC. METHODS: This was a single centre retrospective analysis of patients with ulcerative colitis (UC) and inflammatory bowel disease unclassified (IBDU) who underwent total proctocolectomy with ileal J-pouch between January 2010 and December 2020. The study group comprised patients with negative preoperative CTE/MRE and the control group included patients operated without preoperative CTE/MRE. RESULTS: A total of 131 patients were divided into the negative CTE/MRE study group (76 [58%] patients) and control group (55 [42%] patients). There were no significant differences in incidence rates (21% vs. 23.6%, p = 0.83), time to developing CDLPC from ileostomy closure (22.3 vs. 23.8 months; p = 0.81), pouchitis rates (23.6% vs. 27.2%; p = 0.68), or pouch failure rates (5.2 vs. 7.2; p = 0.71). Multivariate Cox regression analysis showed backwash ileitis (HR 4.1; p = 0.03, CI: 1.1-15.1), severe pouchitis (HR 3.4; p = 0.039, CI: 1.0-10.9), and history of perianal disease (HR 3.4; p = 0.017, CI: 1.4-39.6) were independent predictors for CDLPC. CONCLUSIONS: Negative findings on MRE/CTE prior to J-pouch surgery in ulcerative colitis should be interpreted with caution as it is does not reliably exclude or predict development of CDLPC. These patients should be preoperatively counselled concerning the possibility of developing CDLPC regardless of lack of positive findings on preoperative CTE/MRE. Patients with backwash ileitis with a previous history of perianal disease should be informed of the potentially increased risk of developing such complications.

Surgical treatment of stomal prolapse: A systematic review and meta-analysis of the literature.

AIM: This study aimed to assess success, recurrence, and overall complication rates among different surgical procedures for stomal prolapse. METHODS: This study was a PRISMA-compliant systematic review. PubMed, Scopus, and Google Scholar were searched until March 2022. Studies that assessed surgical treatments of stomal prolapse in adults were included. The primary outcome was recurrence of stomal prolapse and the secondary outcome was 30-day complications. A random-effect meta-analysis was used to estimate the weighted mean rates of recurrence. RESULTS: Six studies published (111 patients; 103 males) were included. 52 (46.8%) patients had end colostomies, 35 (31.5%) had loop colostomies. Seven procedures were assessed and included local stoma reconstruction (40%), stapled local repair (27%), modified Altemeier technique (10%), mesh strip repair (9%), stoma relocation (6%) redo laparotomy repair (5%), and colectomy and end ileostomy (3%). The weighted mean recurrence rate after local stoma reconstruction was 37.2% (95% CI: -1.8 to 76.3), higher than that after the stapled local repair technique (14.9%; 95% CI: 1.7-28.2). The crude recurrence rate of the modified Altemeier technique was 20%, and of stoma relocation was 66.6%. No recurrence was detected after the mesh strip technique (n = 10). The median follow-up ranged between 7 months and 2.5 years. CONCLUSION: Several surgical techniques are available to treat stomal prolapse. Local stoma reconstruction may be associated with high rates of recurrence while the stapled local repair and modified Altemeier procedure has relatively low recurrence. Further larger studies are needed to compare the efficacy of these techniques.

Gracilis muscle interposition for complex perineal fistulas: A systematic review and meta-analysis of the literature.

AIM: Complex perineal fistulas (CPFs) are among the most challenging problems in colorectal practice. Various procedures have been used to treat CPFs, with none being a panacea. Our study aimed to assess the overall success and complication rates after gracilis muscle interposition in patients with CPF. METHOD: PubMed, Scopus and Google Scholar databases were systematically searched until January 2022 according to PRISMA 2020 guidelines. Studies including children <18 years or <10 patients were excluded, as well as reviews, duplicate or animal studies, studies with poor documentation (no report of success rate) and non-English text. An open-source, cross-platform software for advanced meta-analysis openMeta [Analyst]™ version 12.11.14 and Cochrane Review Manager 5.4® were used to conduct the meta-analysis of data. RESULTS: Twenty-five studies published between 2002 and 2021 were identified. The studies included 658 patients (409 women). Most patients had rectovaginal (50.7%) or rectourethral fistulas (33.7%). The most common causes of CPF were pelvic surgery (29.4%) and inflammatory bowel disease (25.2%). A history of radiotherapy was reported in approximately 18% of the patients. 498 (75.7%) patients with CPF achieved complete healing after gracilis muscle interposition. The weighted mean rate of success of the gracilis interposition procedure was 79.4% (95% CI 73.8%-85%, I2  = 75.3%), the weighted mean short-term complication rate was 25.7% (95% CI 18.1-33.2, I2  = 84.1%) and the weighted mean rate for 30-day reoperation was 3.6% (95% CI 1.6-5.6, I2  = 42%). The weighted mean rate of fistula recurrence was 16.7% (95% CI 11%-22.3%, I2  = 61%). CONCLUSION: The gracilis muscle interposition technique is a viable treatment option for CPF. Surgeons should be familiar with indications and techniques to offer it as an option for patients. Given the relatively infrequent use of the operation, referral rather than performance of graciloplasty is an acceptable option.

How reliable is restaging MRI after neoadjuvant therapy in rectal cancer?

BACKGROUND: Despite the pivotal role of magnetic resonance imaging (MRI) in rectal cancer staging and evaluation, the reliability of restaging MRI after neoadjuvant therapy is still debatable. This study aimed to assess the accuracy of restaging MRI by comparing post-neoadjuvant MRI findings with those of the final pathology. METHODS: This study was a retrospective review of the medical records of adult rectal cancer patients who had restaging MRI following neoadjuvant therapy and prior to rectal cancer resection in a NAPRC-certified rectal cancer centre between 2016 and 2021. The study compared findings of preoperative, post-neoadjuvant MRI with final pathology relative to T stage, N stage, tumour size, and circumferential resection margin (CRM) status. RESULTS: A total of 126 patients were included in the study. We found fair concordance (kappa -0.316) for T stage between restaging MRI and pathology report, and slight concordance for N stage and CRM status (kappa -0.11, kappa = 0.089, respectively). Concordance rates were lower for patients following total neoadjuvant treatment (TNT) or with a low rectal tumour. In total, 73% of patients with positive N pathology status had negative N status in the restaging MRI. Sensitivity and specificity regarding positive CRM in post-neoadjuvant treatment MRI were 45.45% and 70.4%, respectively. CONCLUSION: We found low concordance levels between restaging MRI and pathology regarding TN stage and CRM status. Concordance levels were even lower for patients after TNT regimen and with a low rectal tumour. In the era of TNT and watch-and-wait approach, we should not rely solely on restaging MRI to make post-neoadjuvant treatment decisions.

Risk factors and predictors of 30-day complications and conversion to open surgery after repeat ileocolic resection of Crohn's disease.

BACKGROUND: Repeat ileocolic resection of Crohn's disease (CD) is a challenging procedure that can be followed by a high rate of complications. The present study aimed to identify the factors associated with complications and conversion to open surgery in patients undergoing repeat ileocolic resection for CD. METHODS: This was a retrospective review of an IRB-approved prospective database of CD patients who underwent elective repeat ileocolic resection between 2011 and 2021. Univariate and multivariate analyses were performed to determine the predictive factors of postoperative complications and conversion to open surgery. RESULTS: The present study included 65 patients (47.7% male) with a mean age of 52.5 years. 43.1% of patients developed short-term complications, most of which were of Clavien-Dindo class I-II. Longer operative time was found to be an independent predictor of complications (OR 1.016, p = 0.014). The preoperative use of biological therapy was an independent protective factor from complications (OR 0.243, p = 0.016). The only significant risk factor of a longer operation time was higher BMI (OR 3.11, p = 0.044). Overall, 28.1% of laparoscopic procedures were converted to laparotomy. According to bivariate analysis, previous ileocolic open resection (OR 190, p < 0.0001), longer operation time (OR 1.01; p = 0.036), and takedown of incidental fistula of incidental fistula (OR 3.78, p = 0.04) were associated with higher odds of conversion to open surgery. CONCLUSION: Longer operation time was significantly associated with and predictive of complications after repeat ileocolic resection of CD. Preoperative biological therapy was predictive of a lower rate of complications. Previous ileocolic resection by laparotomy, longer operation time, and takedown of fistula were associated with a higher likelihood of conversion to open surgery.

Outcomes of Local Excision Compared to Radical Excision of Rectal Gastrointestinal Stromal Tumors: A Propensity-Score Matched Analysis of the NCDB.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) account for <1% of gastrointestinal cancers. The present study aimed to assess the outcomes of local and radical excision of non-metastatic rectal GISTs. METHODS: This study was a retrospective cohort analysis of patients with non-metastatic rectal GISTs in the NCDB. Patients were divided according to the surgical approach into local and radical excision and were compared in regard to the baseline characteristics and outcomes. A propensity-score matched analysis was performed to match the two groups for baseline confounders. The main outcomes were 5-year overall survival (OS), surgical margins, hospital stay, short-term mortality, and readmission. RESULTS: 228 patients (54.8% male) with rectal GISTs were included. Before matching, 127 (55.7%) patients underwent local excision and 101 (44.3%) had radical excision. Patients who underwent local excision had more cT1-T2 and low-grade GISTs whereas patients who had radical excision received more neoadjuvant systemic treatment. After matching for clinical T stage, tumor grade, and neoadjuvant systemic therapy, 52 patients were included in each group. Local excision had a significantly higher rate of positive resection margins (42.2% vs. 19.1%, p = 0.02) and a shorter hospital stay (0 vs. 3 days, p < 0.001) than radical excision. The two groups had similar mean OS (139.8 vs. 133.1 months, p = 0.52). CONCLUSIONS: Local excision was associated with a significantly higher incidence of positive resection margins and shorter hospital stay, yet similar overall survival to radical excision.

Segmental and extended resections provide comparable survival for clinically node-negative splenic flexure cancer: a propensity score-matched analysis of the National Cancer Database.

PURPOSE: There is an ongoing debate regarding the extent of resection for splenic flexure tumors (SFT). The purpose of this study was to compare segmental and extended resections in terms of overall survival (OS) and pathologic outcomes. METHODS: Retrospective analysis of all patients surgically treated for SFT in the National Cancer Database (NCDB) for the period 2010-2019. Outcomes of segmental and extended resections were compared and a 1:1 propensity score matching was used to match for confounders. Primary outcome was OS. RESULTS: In total 3498/668,852 (0.5%) patients with clinical stage I-III splenic flexure adenocarcinoma in the NCDB were included. Of these, 1533 (43.8%) underwent segmental resection while 1965 (56.1%) underwent extended resection. After matching, mean OS was similar between the groups (92 vs 91 months; p = 0.94). When survival was stratified by clinical N stage, an 8-month survival benefit was shown in the extended resection group for clinical N-positive status (86 vs 78); however, this difference did not achieve statistical significance (p = 0.078). Median number of harvested lymph nodes was significantly lower in the segmental resection group (16 vs 17; p < 0.001) and the percentage of patients with fewer than 12 harvested nodes was significantly higher (18.4% vs 11.6%; p < 0.001). Length of stay was significantly shorter in the segmental resection group (5 vs 6 days; p = 0.027). There were no significant differences between the groups in terms of 30-day readmission or 30- or 90-day mortality. CONCLUSIONS: While segmental and extended resections were associated with similar OS for clinically node-negative SFT, there might be a survival benefit for extended resection in patients with clinical evidence of lymph node involvement.

A Representational Similarity Analysis of Cognitive Control during Color-Word Stroop.

Progress in understanding the neural bases of cognitive control has been supported by the paradigmatic color-word Stroop task, in which a target response (color name) must be selected over a more automatic, yet potentially incongruent, distractor response (word). For this paradigm, models have postulated complementary coding schemes: dorsomedial frontal cortex (DMFC) is proposed to evaluate the demand for control via incongruency-related coding, whereas dorsolateral PFC (DLPFC) is proposed to implement control via goal and target-related coding. Yet, mapping these theorized schemes to measured neural activity within this task has been challenging. Here, we tested for these coding schemes relatively directly, by decomposing an event-related color-word Stroop task via representational similarity analysis. Three neural coding models were fit to the similarity structure of multivoxel patterns of human fMRI activity, acquired from 65 healthy, young-adult males and females. Incongruency coding was predominant in DMFC, whereas both target and incongruency coding were present with indistinguishable strength in DLPFC. In contrast, distractor information was strongly encoded within early visual cortex. Further, these coding schemes were differentially related to behavior: individuals with stronger DLPFC (and lateral posterior parietal cortex) target coding, but weaker DMFC incongruency coding, exhibited less behavioral Stroop interference. These results highlight the utility of the representational similarity analysis framework for investigating neural mechanisms of cognitive control and point to several promising directions to extend the Stroop paradigm.SIGNIFICANCE STATEMENT How the human brain enables cognitive control - the ability to override behavioral habits to pursue internal goals - has been a major focus of neuroscience research. This ability has been frequently investigated by using the Stroop color-word naming task. With the Stroop as a test-bed, many theories have proposed specific neuroanatomical dissociations, in which medial and lateral frontal brain regions underlie cognitive control by encoding distinct types of information. Yet providing a direct confirmation of these claims has been challenging. Here, we demonstrate that representational similarity analysis, which estimates and models the similarity structure of brain activity patterns, can successfully establish the hypothesized functional dissociations within the Stroop task. Representational similarity analysis may provide a useful approach for investigating cognitive control mechanisms.

Pancreatic injuries following laparoscopic splenic flexure mobilization.

PURPOSE: To call awareness to pancreatic injury occurring following laparoscopic splenic flexure mobilization (LSFM) and to discuss the mechanisms which led to such an injury. METHODS: Retrospective review of patients who underwent LSFM as part of their colectomy procedure and sustained pancreatic injuries at a colorectal surgery referral center during 2014-2021. RESULTS: Of 1022 (0.6%) LSFM performed during the study period, six (0.6%) patients were identified in which clinically significant injuries to the pancreas occurred. Two patients had partial transection of the tail of the pancreas and underwent laparoscopic distal pancreatectomy during the index operation. Three patients developed a post-operative pancreatic fistula after their pancreatic injury went undiagnosed during surgery and required percutaneous drainage, one of whom eventually required a distal pancreatectomy for a persistent pancreatic fistula. Another patient developed a peripancreatic fluid collection which resolved with conservative treatment. CONCLUSIONS: Pancreatic injury is rare and a potentially major complication of LSFM. Anatomical misperception, retroperitoneal bleeding, a large bulky splenic flexure tumor, and a "difficult flexure" were recognized as possible mechanisms of such injury.

Redo ileocolic resection in Crohn's disease - does time passed since previous surgery matter?

AIM: Surgical resection for Crohn's disease (CD) remains noncurative, therefore recurrence is a significant problem. Although numerous factors affecting surgical outcomes in redo ileocolic resection have been previously described, no study has considered the relation between the interval of time from initial ileocolic resection to the redo procedure and its effect on surgical outcomes. The aim of this study was to explore this relationship. METHOD: A retrospective review of all adult patients undergoing redo ileocolic resection for CD between 2011 to 2020 was conducted. Patients were divided into two groups based on time from initial ileocolic resection. Patients operated within 10 years of their initial surgery (≤10 years) were assigned to the early group, while patients operated >10 years after initial surgery were allocated to the late group. Primary outcome was the 30-day postoperative major complication rate. RESULTS: Fifty-eight patients underwent redo ileocolic resection, 24 in the early group and 34 in the late group. Apart from older median age in the late group (56 vs. 46.5 years, p = 0.026), the groups were similar for patient factors, disease site and behaviour, use of immune-suppressing medication and procedural factors. Significant differences in 30-day postoperative morbidity included longer length of stay (6 vs. 5 days, p = 0.035), a higher major complication rate (23.5% vs. 4.1%, p = 0.04) and higher readmission rate (26.4% vs. 4.1%, p = 0.035) in the late group. The overall complication rate remained nonsignificant (37.5% vs. 61.8%, p = 0.1). CONCLUSIONS: Redo ileocolic resection, when performed >10 years from the initial ileocolic resection, may be associated with increased morbidity, specifically higher rates of major postoperative complications, a longer length of stay and more readmissions.

The Dual Mechanisms of Cognitive Control Project.

We describe an ambitious ongoing study that has been strongly influenced and inspired by Don Stuss's career-long efforts to identify key cognitive processes that characterize executive control, investigate potential unifying dimensions that define prefrontal function, and carefully attend to individual differences. The Dual Mechanisms of Cognitive Control project tests a theoretical framework positing two key control dimensions: proactive and reactive. The framework's central tenets are that proactive and reactive control modes reflect domain-general dimensions of individual variation, with distinctive neural signatures, involving the lateral pFC as a central node within associated brain networks (e.g., fronto-parietal, cingulo-opercular). In the Dual Mechanisms of Cognitive Control project, each participant is scanned while performing theoretically targeted variants of multiple well-established cognitive control tasks (Stroop, cued task-switching, AX-CPT, Sternberg working memory) in three separate imaging sessions, that each encourages utilization of different control modes plus also completes an extensive out-of-scanner individual differences battery. Additional key features of the project include a high spatio-temporal resolution (multiband) acquisition protocol and a sample that includes a substantial subset of monozygotic twin pairs and participants recruited from the Human Connectome Project. Although data collection is still continuing (target n = 200), we provide an overview of the study design and protocol, along with initial results (n = 80) revealing evidence of a domain-general neural signature of cognitive control and its modulation under reactive conditions. Aligned with Don Stuss's legacy of scientific community building, a partial data set has been publicly released, with the full data set released at project completion, so it can serve as a valuable resource.

Use of indocyanine green fluorescence guidance in redo ileocolic resection for Crohn's disease.

AIM: Redo ileocolic resection in patients with Crohn's disease (CD) is associated with significant technical challenges that may be associated with high complication rates. The aim of this study was to evaluate the feasibility of near-infrared fluorescence angiography with indocyanine green (ICG), often used to evaluate blood supply to the anastomosis in CD patients undergoing repeat ileocolic resection. METHOD: This study was a retrospective analysis of patients who underwent redo ileocolic resection using ICG bowel perfusion assessment between 2015 and 2021. Patients were matched and compared on a 1:2 basis with a control group undergoing the same procedure without perfusion assessment. RESULTS: Twelve patients underwent redo ileocolic resection with ICG perfusion assessment (ICG group). These were compared with 24 patients who underwent the procedure without ICG (control group). Both groups were similar in demographics and operative characteristics including median operating time (255 vs. 255.5 min, p = 0.39) and conversion rate (22% vs. 36.8%, p = 0.68). Median estimated blood loss was significantly higher in the ICG group [150 (50-400) vs. 100 ml (20-125)]. Successful ICG perfusion assessment was seen in all patients in the ICG group and did not change management in any case. Overall postoperative complication rates were comparable between the groups (58.3% vs. 54.1%, p = 0.72). No anastomotic leaks occurred in the ICG group compared with one (1/24, 4.2%) in the control group (p = 0.99). CONCLUSION: Fluorescence ICG perfusion assessment is feasible and safe in redo ileocolic resection in patients with CD. Larger studies are needed to evaluate whether this technique should be routinely used in these complex surgical interventions.

A Review on Advanced Sensing Materials for Agricultural Gas Sensors.

This work is a comprehensive review of sensing materials, which interact with several target gases pertinent to agricultural monitoring applications. Sensing materials which interact with carbon dioxide, water vapor (relative humidity), hydrogen sulfide, ethylene and ethanol are the focus of this work. Performance characteristics such as dynamic range, recovery time, operating temperature, long-term stability and method of deposition are discussed to determine the commercial viability of the sensing materials considered in this work. In addition to the sensing materials, deposition methods are considered to obtain the desired sensing material thickness based on the sensor's mechanism of operation. Various material classes including metal oxides, conductive polymers and carbon allotropes are included in this review. By implementing multiple sensing materials to detect a single target analyte, the issue of selectivity due to cross sensitivity can be mitigated. For this reason, where possible, it is desirable to utilize more than one sensing material to monitor a single target gas. Among those considered in this work, it is observed that PEDOT PSS/graphene and TiO2-coated g-C3N4 NS are best suited for CO2 detection, given their wide dynamic range and modest operating temperature. To monitor the presence of ethylene, BMIM-NTf2, SWCNTs and PtTiO2 offer a dynamic range most suitable for the application and require no active heating. Due to the wide dynamic range offered by SiO2/Si nanowires, this material is best suited for the detection of ethanol; a gas artificially introduced to prolong the shelf life of the harvested crop. Finally, among all other sensing materials investigated, it observed that both SWCNTs and CNTs/SnO2/CuO are most suitable for H2S detection in the given application.