Larson, David W

Objective: To develop a predictive model for pathological complete response (pCR) after total neoadjuvant therapy (TNT) to inform selection for watch-and-wait (W/W). Summary Background Data: Patient selection for W/W after TNT for locally advanced rectal cancer remains challenging. Methods: An ensemble of tabular foundation models was fine-tuned in adults with clinical stage II or III microsatellite stable primary rectal adenocarcinoma undergoing TNT and total mesorectal excision (TNT+TME) from 2018-2023 to predict pCR, using pre-TNT, post-TNT and pre-TME variables. This model was externally validated on patients having TNT and W/W (TNT+W/W) to predict persistent clinical complete response (pcCR; the absence of local regrowth, distant metastases, or persistent near-cCR). Area under the receiver operator curve (AUROC), area under the precision-recall curve (AUPRC), and Brier score were calculated with 95% confidence intervals (CI). Results: Among 308 patients that underwent TNT+TME (median age 56; 40% female), the model predicted pCR with an AUROC 0.71 (95% CI 0.65-0.77), AUPRC 0.44 (95% CI 0.35-0.57), and was well calibrated with a Brier score of 0.17 (95% CI 0.15-0.20). At external validation in a cohort of 83 patients that are being managed with TNT+W/W (median age 57; 37% female), the model predicted pcCR with an AUROC 0.69 (95% CI 0.57-0.82), AUPRC 0.90 (95% CI 0.82-0.96), and Brier score of 0.30 (95% CI 0.26-0.33), improving to 0.17 with recalibration. Conclusions: This novel predictive model demonstrated good discrimination and calibration for pCR after TNT+TME with utility in TNT+W/W for pcCR after appropriate recalibration, supporting its application for W/W patient selection.

Abstract Introduction Ileal pouch–anal anastomosis (IPAA) is a common surgical procedure for patients with ulcerative colitis or familial adenomatous polyposis. This study compared the outcomes of robotic, laparoscopic, and open IPAA techniques, with a focus on surgical complications and pouch failure rates. Methods A retrospective study was conducted of patients who underwent IPAA at three Mayo Clinic locations between 2015 and 2020. Data on patient demographics, surgical details, and postoperative outcomes were collected and compared across the three surgical approaches. Pouch failure was defined as the need for pouch excision or a diverting loop ileostomy. Results In all, 401 patients underwent IPAA with either an open (149, 37.2%), robotic (145, 36.2%), or laparoscopic (107, 26.7%) technique. The overall rate of pouch failure was 6.5% and did not differ significantly between the three surgical approaches. Compared with laparoscopy, robotic IPAA was associated with a lower conversion rate to open surgery (1.4 versus 17.8%; P < 0.0001) and fewer 30-day readmissions (15.9% versus 28.0%; P = 0.02). However, robotic and laparoscopic IPAA approaches had higher rates of venous thromboembolism/pulmonary embolism and readmission than the open approach. Pouchitis was the most common cause of pouch failure across all surgical techniques. Conclusion Robotic IPAA had lower conversion and reduced 30-day admission rates compared with a laparoscopic approach. However, open surgery had lower rates of 30-day readmission and rates thromboembolism than robotic IPAA. The surgical approach itself does not appear to significantly impact long-term pouch failure rates.

Lay Summary Oral vancomycin shows promise in treating pouchitis in patients with primary sclerosing cholangitis and ulcerative colitis. In this study, vancomycin helped reduce stool frequency, urgency, and incontinence. More research is needed to confirm its long-term benefits and best treatment practices.

Background and Objectives: Perineal wound complications and pelvic fluid collections or abscesses following proctectomy for Crohn’s disease are a common cause of morbidity and might be mitigated by filling the pelvis and occluding the pelvic inlet with a flap. Alternative flap options can be considered when inadequate omentum is available and when avoiding myofasciocutaneous flaps. Materials and Methods: A retrospective review of our Crohn’s proctectomy database was conducted to identify patients who underwent a non-omental or non-myofasciocutaneous local pedicle flap to their pelvis or pelvic exclusion using biological material during surgery. The techniques and outcomes of these alternative techniques are described in detail. Results: 228 patients underwent proctectomy for Crohn’s disease during the 10-year study period. However, only six patients had their pelvis filled or pelvic inlet occluded using a non-omental, non-myofasciocutaneous local pedicled flap or biological material. The techniques identified included two sigmoid mesocolic flaps, one peritoneal, preperitoneal fat and falciform ligament flap, one perivesical fat flap, one Gerota’s fat pad flap, and one bovine pericardial patch assisted pelvic exclusion. These flaps’ clinicopathological and operative characteristics, surgical outcomes, and technical aspects are described. Conclusions: When greater omentum is unavailable or inadequate and myofasciocutaneous flaps need to be avoided, local pedicled flaps using a range of intra-abdominal tissues or biological material can be used to fill the pelvis or occlude the pelvic inlet after proctectomy for Crohn’s disease. These techniques may help to prevent short and long-term complications associated with having a pelvic dead space.

AbstractAimMinimally invasive transanal platforms are now the standard of care for select low‐risk rectal tumours. However, existing platforms come with persistent technical challenges. The da Vinci SP Surgical System™ offers a new alternative designed to work effectively in narrow spaces. This technology has the potential to enhance the feasibility and proximal extent of complex transanal resections. This study aimed to describe the morbidity and technical success in patients undergoing single‐port robotic transanal minimally invasive surgery (SPR‐TAMIS). Secondary outcomes include rates of local recurrence.MethodsA retrospective analysis was conducted on all patients who underwent SPR‐TAMIS at our institution between February 2019 and December 2023.ResultsThe study included 31 patients (19 men, 12 women) with a mean age of 61 ± 13.3 years. The average tumour distance from the anal verge was 10 cm. Thirty patients completed SPR‐TAMIS, with one patient requiring conversion to robotic sigmoidectomy due to location in the mid‐sigmoid colon. The mean operating time was 106 ± 42 min. Twenty‐eight out of 30 patients underwent full‐thickness excision and all but two were successfully closed. All specimens were resected intact, and margins were negative in 93.5% of cases. The average tumour size was 13 ± 34 cm2, with 13 lesions classified as adenomas and 16 as adenocarcinomas. All patients who did not undergo associated procedures were discharged on the day of surgery. Two patients experienced 30‐day morbidity. At a mean follow‐up of 18 months (± 13), no local or systemic recurrences were identified.ConclusionSPR‐TAMIS for excision of low‐risk rectal tumours is associated with high rates of technical success and low 30‐day morbidity. Further research is needed to compare SPR‐TAMIS with other techniques to determine potential advantages over current transanal platforms.

BACKGROUND: Concerns persist regarding the effectiveness of robotic proctectomy compared with open proctectomy for locally advanced rectal cancer with a high risk of circumferential resection margin involvement. OBJECTIVE: Comparison of surrogate cancer outcomes after robotic versus open proctectomy in this subpopulation. DESIGN: Retrospective cohort study. SETTING: Three academic hospitals (Mayo Clinic Arizona, Florida, and Rochester) with data available through the Mayo Data Explorer platform. PATIENTS: Patients at high risk of circumferential resection margin involvement were selected on the basis of the MRI-based definition from the MERCURY I and II trials. MAIN OUTCOME MEASURES: Rate of pathologic circumferential resection margin involvement (≤1 mm), mesorectal grading, and rate of distal margin involvement. RESULTS: Out of 413 patients, 125 (30%) underwent open and 288 (70%) underwent robotic proctectomy. Open proctectomy was significantly associated with a greater proportion of cT4 tumors (39.3% vs 24.8%, p = 0.021), multivisceral/concomitant resections (40.8% vs 18.4%, p < 0.001), and less frequent total neoadjuvant therapy use (17.1% vs 47.1%, p = 0.001). Robotic proctectomy was less commonly associated with pathologic circumferential resection margin involvement (7.3% vs 17.6%, p = 0.002), including after adjustment for cT stage, neoadjuvant therapy, and multivisceral resection (OR 0.326; 95% CI, 0.157–0.670, p = 0.002). Propensity score matching for 66 patients per group and related multivariable analysis no longer indicated any reduction of circumferential positive margin rate associated with robotic surgery ( p = 0.86 and p = 0.18). Mesorectal grading was comparable (incomplete mesorectum in 6% robotic proctectomy patients vs 11.8% open proctectomy patients, p = 0.327). All cases had negative distal resection margins. LIMITATION: Retrospective design. CONCLUSIONS: In patients with locally advanced rectal cancer at high risk of circumferential resection margin involvement, robotic proctectomy is an effective approach and could be pursued when technically possible as an alternative to open proctectomy. See Video Abstract . RESULTADOS COMPARATIVOS ENTRE LA PROCTECTOMÍA ROBÓTICA Y LA PROCTECTOMÍA ABIERTA EN CASOS DE CÁNCER DE RECTO CON ALTO RIESGO DE MÁRGEN DE RESECCIÓN CIRCUNFERENCIAL POSITIVO ANTECEDENTES: Persisten preocupaciones con respecto a la efectividad de la proctectomía robótica en comparación con la proctectomía abierta en casos de cáncer de recto localmente avanzado con un alto riesgo de margen de resección circunferencial positivo. OBJETIVO: Comparar los resultados en la subpoblación de portadores de cáncer luego de una proctectomía robótica versus una proctectomía abierta. DISEÑO: Estudio retrospectivo de cohortes. AJUSTE: Realizado en tres hospitales académicos (Mayo Clinic de Arizona, Florida y Rochester) a través de la plataforma Mayo Data Explorer. PACIENTES: Fueron seleccionados aquellos pacientes con alto riesgo de compromiso sobre el margen de resección circunferencial, según la definición de los Estudios Mercury I-II basada en la Imágen de Resonancia Magnética. MEDIDAS DE RESULTADO PRINCIPALES Y SECUNDARIAS: La tasa de compromiso patológico sobre el margen de resección circunferencial (≤1 mm), la clasificación mesorrectal y la tasa del compromiso del margen distal. RESULTADOS: De 413 pacientes, 125 (30%) fueron sometidos a una proctectomía abierta y 288 (70%) a proctectomía robótica. La proctectomía abierta se asoció significativamente con una mayor proporción de tumores cT4 (39,3% frente a 24,8%, p = 0,021), las resecciones multiviscerales/concomitantes fueron de 40,8% frente a 18,4%, p < 0,001 y una adminstración menos frecuente de terapia neoadyuvante total (17,1). % vs 47,1%, p = 0,001). La proctectomía robótica se asoció con menos frecuencia con la presencia de una lesión sobre el margen de resección circunferencial patológico (7,3% frente a 17,6%, p = 0,002), incluso después del ajuste por estadio cT, de la terapia neoadyuvante y de resección multivisceral (OR 0,326, IC 95% 0,157-0,670, p = 0,002). El apareado de propensión por puntuación en 66 pacientes por grupo y el análisis multivariable relacionado, no mostraron ninguna reducción en la tasa de margen positivo circunferencial asociado con la cirugía robótica ( p = 0,86 y p = 0,18). La clasificación mesorrectal fue igualmente comparable (mesorrecto incompleto en el 6% de los pacientes con RP frente al 11,8% de los pacientes con OP, p = 0,327). Todos los casos tuvieron márgenes de resección distal negativos. LIMITACIÓN: Diseño retrospectivo. CONCLUSIÓN: En pacientes con cáncer de recto localmente avanzado con alto riesgo de compromiso del margen de resección circunferencial, la proctectomía robótica es un enfoque eficaz y podría realizarse cuando sea técnicamente posible como alternativa a la proctectomía abierta. (Traducción—Dr. Xavier Delgadillo )

BACKGROUND: IPAA has become the criterion standard for treating ulcerative colitis, familial adenomatous polyposis, and selected cases of Crohn’s colitis. Robotic surgery promises improved postoperative outcomes and decreased length of stay. However, few studies have evaluated the benefits of robotic IPAA compared to laparoscopy. OBJECTIVE: To compare short-term 30-day postoperative outcomes of robotic versus laparoscopic proctectomy with IPAA and diverting loop ileostomy. DESIGN: Retrospective observational study from a single, high-volume center. SETTINGS: Mayo Clinic, Rochester, Minnesota (tertiary referral center for IBD). PATIENTS: All adult patients undergoing minimally invasive proctectomy with IPAA and diverting loop ileostomy between January 2015 and April 2023. MAIN OUTCOME MEASURES: Thirty-day complications, hospital length of stay, estimated blood loss, conversion rate, 30-day readmission, and 30-day reoperation. RESULTS: Two hundred seventeen patients were included in the study; 107 underwent robotic proctectomy with IPAA and diverting loop ileostomy, whereas 110 had laparoscopic proctectomy with IPAA and diverting loop ileostomy. Operating time was significantly longer in the robotic group (263 ± 38 vs 228 ± 75 minutes, p < 0.0001). The robotic group also had lower estimated blood loss (81.5 ± 77.7 vs 126.8 ± 111.0 mL, p = 0.0006) as well as fewer conversions (0% vs 8.2%, p = 0.003). Patients in the robotic group received more intraoperative fluids (3099 ± 1140 vs 2472 ± 996 mL, p = 0.0001). However, there was no difference in length of stay, 30-day morbidity, 30-day readmission, 30-day reoperation, rate of diverting loop ileostomy closure at 3 months, and surgical IPAA complication rate after ileostomy closure. LIMITATIONS: Retrospective design, single-center study, potential bias because of the novelty of the robotic approach, and lack of long-term and quality-of-life outcomes. CONCLUSIONS: Robotic proctectomy with IPAA and diverting loop ileostomy may offer advantages in terms of estimated blood loss and conversion rate while maintaining the benefits of minimally invasive surgery. Further research is needed to evaluate long-term outcomes. See Video Abstract. NAVEGANDO EL PROGRESO: EXPERIENCIA DE OCHO AÑOS EN UN SOLO CENTRO CON PROCTECTOMÍA MÍNIMAMENTE INVASIVA Y ANASTOMOSIS ANAL-BOLSA ILEAL ANTECEDENTES: La anastomosis anal-bolsa ileal (IPAA) se ha convertido en el estándar de oro para el tratamiento de la colitis ulcerosa, la poliposis adenomatosa familiar y casos seleccionados de colitis de Crohn. La cirugía robótica promete mejores resultados posoperatorios y una menor duración de la estancia hospitalaria. Sin embargo, pocos estudios han evaluado los beneficios de la IPAA robótica en comparación con la laparoscopia. OBJETIVO: Comparar los resultados postoperatorios a corto plazo a 30 días de la proctectomía robótica versus laparoscópica con IPAA e ileostomía en asa de derivación. DISEÑO: Estudio observacional retrospectivo de un único centro de gran volumen. AJUSTES: Mayo Clinic, Rochester, Minnesota (centro terciario de referencia para EII). PACIENTES: Todos los pacientes adultos sometidos a proctectomía mínimamente invasiva con IPAA y DLI entre Enero de 2015 y Abril de 2023. PRINCIPALES MEDIDAS DE RESULTADOS: Complicaciones a los 30 días, duración de la estancia hospitalaria, pérdida de sangre estimada, tasa de conversión, reingreso a los 30 días y reoperación a los 30 días. RESULTADOS: Se incluyeron en el estudio 217 pacientes; 107 se sometieron a proctectomía robótica con IPAA y DLI, mientras que 110 se sometieron a proctectomía laparoscópica con IPAA y DLI. El tiempo operatorio fue significativamente mayor en el grupo robótico (263 ± 38 minutos versus 228 ± 75 minutos, p < 0,0001); la pérdida de sangre estimada (EBL) fue menor en el grupo robótico (81,5 ± 77,7 ml versus 126,8 ± 111,0 ml, p = 0,0006), así como el número de conversiones (0% versus 8,2%, p = 0,003). Los pacientes del grupo robótico recibieron más líquidos intraoperatorios (3099 ± 1140 ml versus 2472 ± 996 ml, p = 0,0001). Sin embargo, no hubo diferencias en la duración de la estancia hospitalaria, la morbilidad a los 30 días, el reingreso a los 30 días, la reoperación a los 30 días, la tasa de cierre del DLI a los tres meses y la tasa de complicaciones quirúrgicas de la IPAA después del cierre de la ileostomía. LIMITACIONES: Diseño retrospectivo, estudio unicéntrico, posible sesgo debido a la novedad del enfoque robótico, falta de resultados a largo plazo y de calidad de vida. CONCLUSIONES: La proctectomía robótica con IPAA y DLI puede ofrecer ventajas en términos de EBL y tasa de conversión, manteniendo al mismo tiempo los beneficios de la cirugía mínimamente invasiva. Se necesita más investigación para evaluar los resultados a largo plazo. (Traducción—Dr. Yesenia Rojas-Khalil)