Time Interval Between the End of Neoadjuvant Therapy and Elective Resection of Locally Advanced Rectal Cancer in the CRONOS Study.

Importance: The treatment for extraperitoneal locally advanced rectal cancer (LARC) is neoadjuvant therapy (NAT) followed by total mesorectal excision (TME). Robust evidence on the optimal time interval between NAT completion and surgery is lacking. Objective: To assess the association of time interval between NAT completion and TME with short- and long-term outcomes. It was hypothesized that longer intervals increase the pathologic complete response (pCR) rate without increasing perioperative morbidity. Design, Setting, and Participants: This cohort study included patients with LARC from 6 referral centers who completed NAT and underwent TME between January 2005 and December 2020. The cohort was divided into 3 groups depending on the time interval between NAT completion and surgery: short (≤8 weeks), intermediate (>8 and ≤12 weeks), and long (>12 weeks). The median follow-up duration was 33 months. Data analyses were conducted from May 1, 2021, to May 31, 2022. The inverse probability of treatment weighting method was used to homogenize the analysis groups. Exposure: Long-course chemoradiotherapy or short-course radiotherapy with delayed surgery. Main outcome and Measures: The primary outcome was pCR. Other histopathologic results, perioperative events, and survival outcomes constituted the secondary outcomes. Results: Among the 1506 patients, 908 were male (60.3%), and the median (IQR) age was 68.8 (59.4-76.5) years. The short-, intermediate-, and long-interval groups included 511 patients (33.9%), 797 patients (52.9%), and 198 patients (13.1%), respectively. The overall pCR was 17.2% (259 of 1506 patients; 95% CI, 15.4%-19.2%). When compared with the intermediate-interval group, no association was observed between time intervals and pCR in short-interval (odds ratio [OR], 0.74; 95% CI, 0.55-1.01) and long-interval (OR, 1.07; 95% CI, 0.73-1.61) groups. The long-interval group was significantly associated with lower risk of bad response (tumor regression grade [TRG] 2-3; OR, 0.47; 95% CI, 0.24-0.91), systemic recurrence (hazard ratio, 0.59; 95% CI, 0.36-0.96), higher conversion risk (OR, 3.14; 95% CI, 1.62-6.07), minor postoperative complications (OR, 1.43; 95% CI, 1.04-1.97), and incomplete mesorectum (OR, 1.89; 95% CI, 1.02-3.50) when compared with the intermediate-interval group. Conclusions and Relevance: Time intervals longer than 12 weeks were associated with improved TRG and systemic recurrence but may increase surgical complexity and minor morbidity.

Aplicación de reconstrucción 3D e inteligencia artificial a la escisión completa de mesocolon y linfadenectomía D3 en el cáncer de colon / Application of 3D-reconstruction and artificial intelligence for complete mesocolic excision and D3 lymphadenectomy in colon cancer

Las técnicas de reconstrucción 3D basadas en algoritmos matemáticos y la inteligencia artificial son una línea de innovación actual en cirugía oncológica colorrectal. El objetivo de este estudio es mostrar la experiencia inicial de un sistema de procesamiento de imagen y reconstrucción 3D en la planificación de escisión completa de mesocolon y linfadenectomía D3 en cáncer de colon. Se aplica en un caso de neoplasia de ángulo esplénico, así como en neoplasia de colon derecho con sospecha de infiltración retroperitoneal. Se empleó el procesamiento de imagen y reconstrucción 3D para delimitar un margen intestinal de 10cm proximal y distal al tumor y delimitar la vascularización correspondiente a la tumoración. En el cáncer de colon derecho se mostró la posición y dimensiones exactas del área de linfadenectomía D3 y posible infiltración de la fascia retroperitoneal. El procesamiento de imagen y reconstrucción 3D permite obtener información valiosa a partir de la tomografía computarizada. Esta podría emplearse en la estrategia quirúrgica y así mejorar los resultados oncológicos y disminuir las complicaciones intraoperatorias. (AU)

Mathematical algorithms 3D-reconstruction techniques and artificial intelligence are a current line of innovation in colorectal surgical oncology. The objective of this study is to show the initial experience of a 3D image processing and reconstruction system to perform complete mesocolic excision and D3-lymphadenectomy in colon cancer. It is applied to a splenic flexure neoplasm and in a right colon cancer with suspected retroperitoneal infiltration. 3D image processing and reconstruction was employed to delimit 10cm proximal and distal intestinal margins to the tumor and define its corresponding vascularization. In right colon cancer it showed position and exact dimensions of D3-lymphadenectomy area and possible retroperitoneal fascia infiltration. 3D image processing and reconstruction allows to obtain valuable information from computerized tomography scan. It could be employed during surgical strategy planification to improve oncological results and reduce intraoperative complications. (AU)

WITHDRAWN: Bacteroides thetaiotaomicron necrotizing fasciitis as presentation of colorectal cancer, with subsequent cutaneous exteriorization.

Ahead of Print article withdrawn by publisher. An 80-year-old woman presented necrotizing fasciitis on the right flank, requiring debridement. Tomography reported ascending colon neoplasm fistulized to the skin. Colonoscopy confirms adenocarcinoma. Intervention postponed due to rejection of surgery during the pandemic and SARS-COV-2 infection, producing progression with exteriorization of the neoplasm. A bloc laparotomic right hemicolectomy was performed (pT4bN0).

Three-dimensional modelling as a novel interactive tool for preoperative planning for complex perianal fistulas in Crohn's disease.

AIM: The aim of this study is to demonstrate the added value of three-dimensional (3D) reconstruction models and artificial intelligence for preoperative planning in complex perianal Crohn's disease. MRI is the gold standard for diagnosis of complex perianal fistulas and abscess due to its high sensitivity, but it lacks high specificity values. This creates the need for better diagnostic models such as 3D image processing and reconstruction (3D-IPR) with artificial intelligence (AI) algorithms. METHOD: This is a prospective study evaluating the utility of 3D reconstruction models from MRI in four patients with perineal Crohn's disease (pCD). RESULTS: Four pCD patients had 3D reconstruction models made from pelvic MRI. This provided a more visual representation of perianal disease and made possible location of the internal fistula orifice, seton placement in fistula tracts and abscess drainage. CONCLUSION: Three-dimensional reconstruction in CD-associated complex perianal fistulas can facilitate disease interpretation, anatomy and surgical strategy, potentially improving preoperative planning as well as intraoperative assistance. This could probably result in better surgical outcomes to control perianal sepsis and reduce the number of surgical procedures required in these patients.

Application of 3D-reconstruction and artificial intelligence for complete mesocolic excision and D3 lymphadenectomy in colon cancer.

Mathematical algorithms 3D-reconstruction techniques and artificial intelligence are a current line of innovation in colorectal surgical oncology. The objective of this study is to show the initial experience of a 3D image processing and reconstruction system to perform complete mesocolic excision and D3-lymphadenectomy in colon cancer. It is applied to a splenic flexure neoplasm and in a right colon cancer with suspected retroperitoneal infiltration. 3D image processing and reconstruction was employed to delimit 10 cm proximal and distal intestinal margins to the tumor and define its corresponding vascularization. In right colon cancer it showed position and exact dimensions of D3-lymphadenectomy area and possible retroperitoneal fascia infiltration. 3D image processing and reconstruction allows to obtain valuable information from computerized tomography scan. It could be employed during surgical strategy planification to improve oncological results and reduce intraoperative complications.

Resultados de una encuesta nacional sobre el uso de stent para el tratamiento de la obstrucción de colon / Results of a national survey on the use of stents for the treatment of colonic obstruction

INTRODUCCIÓN: Difundimos una encuesta con el objetivo de conocer las indicaciones actuales para la utilización del stent de colon para el tratamiento de la obstrucción colónica en España y su adecuación a las guías internacionales. MÉTODOS: Estudio descriptivo de una encuesta distribuida por la Asociación Española de Cirujanos, la Societat Catalana de Cirurgía y la Sociedad Española de Endoscopia Digestiva. RESULTADOS: Se recibieron 340 respuestas válidas, un 25% de médicos digestólogos, y el 75% de cirujanos generales. Durante el último año el 44,4% de los encuestados valoró entre 10 a 20 COC. Un 52,2% indicó menos de 5 stents/año, y de estos el 75% se indicó como paso previo a una cirugía preferente y solo el 25% se realizó con intención paliativa. Un 55,3% de los participantes refirió conocer las guías oficiales. El 64% de los encuestados utilizaría el stent como paso previo a cirugía en ancianos con enfermedad localizada. El 75,9% colocaría stent con fines paliativos en jóvenes con carcinomatosis, y un 61,8% los utilizaría en neoplasias estadio IV en tratamiento con quimioterapia. Solo un 18,1% conocía el riesgo de perforación de colon tras stent en pacientes en tratamiento con antiangiogénicos. CONCLUSIONES: En España la indicación del stent de colon se reserva para casos seleccionados y varía según la especialidad y los años de experiencia del encuestado. La adecuación a las guías internacionales para la mayoría de los encuestados es moderada. Es importante insistir en el alto riesgo de perforación tras angiogénicos, pues la mayoría de profesionales lo desconocen

INTRODUCTION: We distributed a survey in order to determine the current indications for the use of colonic stents to treat colonic obstruction in Spain and its compliance with international guidelines. METHODS: Descriptive study of a survey distributed by the Spanish Association of Surgeons (Asociación Española de Cirujanos), the Catalan Society of Surgery (Societat Catalana de Cirurgia) and the Spanish Society of Digestive Endoscopy (Sociedad Española de Endoscopia Digestiva). RESULTS: 340 valid responses were received: 25% from gastrointestinal specialists, and 75% from general surgeons. During the last year, 44.4% of respondents assessed between 10 and 20 COC. Of these, 52.2% indicated less than 5 stents/year, 75% of which were indicated as a prior step to preferential surgery and only 25% were performed with palliative intent. 55.3% of the participants reported knowing the official guidelines, and 64% of respondents would use the stent as a step prior to surgery in elderly patients with localized disease. 75.9% would place stents as palliative therapy in young patients with carcinomatosis, and 61.8% would use them in stage IV malignancies under treatment with chemotherapy. Only 18.1% knew of the risk of colon perforation after stent placement in patients undergoing treatment with antiangiogenics. CONCLUSIONS: In Spain, the indication for colonic stents is reserved for selected cases and varies according to the specialty and the years of experience of the respondent. The compliance with international guidelines of most respondents is moderate. It is important to insist on the high risk of perforation after angiogenics, which is unknown to most surgeons

Results of a national survey on the use of stents for the treatment of colonic obstruction. / Resultados de una encuesta nacional sobre el uso de stent para el tratamiento de la obstrucción de colon.

INTRODUCTION: We distributed a survey in order to determine the current indications for the use of colonic stents to treat colonic obstruction in Spain and its compliance with international guidelines. METHODS: Descriptive study of a survey distributed by the Spanish Association of Surgeons (Asociación Española de Cirujanos), the Catalan Society of Surgery (Societat Catalana de Cirurgia) and the Spanish Society of Digestive Endoscopy (Sociedad Española de Endoscopia Digestiva). RESULTS: 340 valid responses were received: 25% from gastrointestinal specialists, and 75% from general surgeons. During the last year, 44.4% of respondents assessed between 10 and 20 COC. Of these, 52.2% indicated less than 5 stents/year, 75% of which were indicated as a prior step to preferential surgery and only 25% were performed with palliative intent. 55.3% of the participants reported knowing the official guidelines, and 64% of respondents would use the stent as a step prior to surgery in elderly patients with localized disease. 75.9% would place stents as palliative therapy in young patients with carcinomatosis, and 61.8% would use them in stage IV malignancies under treatment with chemotherapy. Only 18.1% knew of the risk of colon perforation after stent placement in patients undergoing treatment with antiangiogenics. CONCLUSIONS: In Spain, the indication for colonic stents is reserved for selected cases and varies according to the specialty and the years of experience of the respondent. The compliance with international guidelines of most respondents is moderate. It is important to insist on the high risk of perforation after angiogenics, which is unknown to most surgeons.