Colorectal Surgery Research Articles

Shorter interval to surgery after self-expanding metallic stent may result in better oncologic outcomes in colon cancer obstruction

IntroductionColon cancer obstruction is one of the most serious conditions in colorectal surgery. However, the use of self-expanding metallic stent (SEMS) has made it possible to avoid emergency surgery and stoma creation, therefore enabling minimally invasive surgery and one-stage operation. In this study, we aimed to investigate whether there is an optimal interval from SEMS to surgery for the best long-term oncologic outcomes. MethodsObstructive colon cancer patients treated with SEMS insertion and received surgery were included in the study. Patient data were retrospectively reviewed in prospectively collected data. Using the ROC curve, the optimal interval to surgery after SEMS insertion was 10 days; the patients were divided into the early surgery group (≤10 days, ES) and the late surgery group (>10 days, LS). Factors contributing to the 5-year disease-free survival (DFS) and overall survival (OS) were analyzed. Results83 patients were included in this study. Eight patients (9.6 %) had SEMS insertion failure, with 3 perforations and 5 failed expansions. There were no differences between the ES group and the LS group in terms of pathologic characteristics, incidence of stoma creation, and adjuvant chemotherapy. Twenty-six patients (31.3 %) had recurrences; local (Arnarson et al., 2023) [6], peritoneal seeding (Lee et al., 2013) [8], liver (Ho et al., 2017) [11], lung [7], bone (van Hooft et al., 2020) [2], and abdominal wall metastasis (Chen and Sheen-Chen, 2000) [1]. The 5-year DFS rate was significantly better in the ES group than the LS group (74.3 % vs. 55.01 %; p = 0.0394). The 5-year OS was slightly better in the ES group than the LS group (76.11 % vs. 58.75 %; p = 0.0901). In univariable analysis, the ES group showed a lower risk of recurrence than the LS group (OR: 0.447 [0.204–0.984], p = 0.0455), but this was not reproduced in the multivariable analysis. ConclusionThis study has shown that the long-term oncologic outcomes were better in patients who received surgery after SEMS within 10 days. Hence, we propose with caution that elective surgery might be suggested to take place within 10 days from SEMS insertion for better oncologic outcomes.

Neoadjuvant Immunotherapy and Intestinal Microbiota: Unraveling their roles in Anastomotic Leakage and Fistula after Colorectal Cancer Surgery

This comprehensive review explores the multifaceted relationship between neoadjuvant immunotherapy, intestinal microbiota alterations, and anastomotic leakage risk in patients undergoing colectomy for colon neoplasia. With the advent of immunotherapy, remarkably immune checkpoint inhibitors, there has been a significant shift in the treatment paradigms for various cancers, including colon neoplasia. These treatments, while effective, have been associated with changes in the intestinal microbiome, which, in turn, may influence wound healing and the integrity of anastomotic sites. The review delves into the complex interactions between the immune system and the gut microbiota, examining how immunotherapy-induced dysbiosis could disrupt the delicate balance necessary for optimal anastomotic healing. It discusses the role of specific bacterial species in modulating the immune response to cancer and their impact on the efficacy of immunotherapeutic agents. Moreover, the review highlights the potential mechanisms through which the microbiota-immune system interaction could affect surgical outcomes, focusing on the development of anastomotic leaks. The implications of these findings for clinical practice are discussed, including the need for targeted strategies to modulate the gut microbiota in patients undergoing immunotherapy and colectomy. Through this discussion, the review aims to provide insights into improving patient outcomes by integrating microbiome management into colon neoplasia patients' treatment and perioperative care.

Gastrointestinal functions after laparoscopic right colectomy with intracorporeal anastomosis: a pilot randomized clinical trial on effects of abdominal drain, prolonged antibiotic prophylaxis, and D3 lymphadenectomy with complete mesocolic excision

PurposeRoutine use of abdominal drain or prolonged antibiotic prophylaxis is no longer part of current clinical practice in colorectal surgery. Nevertheless, in patients undergoing laparoscopic right hemicolectomy with intracorporeal anastomosis (ICA), it may reduce perioperative abdominal contamination. Furthermore, in cancer patients, prolonged surgery with extensive dissection such as central vascular ligation and complete mesocolon excision with D3 lymphadenectomy (altogether radical right colectomy RRC) is called responsible for affecting postoperative ileus. The aim was to evaluate postoperative resumption of gastrointestinal functions in patients undergoing right hemicolectomy for cancer with ICA and standard D2 dissection or RRC, with or without abdominal drain and prolonged antibiotic prophylaxis.MethodsMonocentric factorial parallel arm randomized pilot trial including all consecutive patients undergoing laparoscopic right hemicolectomy and ICA for cancer, in 20 months. Patients were randomized on a 1:1:1 ratio to receive abdominal drain, prolonged antibiotic prophylaxis or neither (I level), and 1:1 to receive RRC or D2 colectomy (II level). Patients were not blinded. The primary aim was the resumption of gastrointestinal functions (time to first gas and stool, time to tolerated fluids and food). Secondary aims were length of stay and complications’ rate. ClinicalTrials.gov no. NCT04977882.ResultsFifty-seven patients were screened; according to sample size, 36 were randomized, 12 for each arm for postoperative management, and 18 for each arm according to surgical techniques. A difference in time to solid diet favored the group without drain or antibiotic independently from standard or RRC. Furthermore, when patients were divided with respect to surgical technique and into matched cohorts, no differences were seen for primary and secondary outcomes.ConclusionAbdominal drainage and prolonged antibiotic prophylaxis in patients undergoing right hemicolectomy for cancer with ICA seem to negatively affect the resumption of a solid diet after laparoscopic right hemicolectomy with ICA for cancer. RRC does not seem to influence gastrointestinal function recovery.

Surgical Site Infections in Colorectal Cancer Surgeries: A Systematic Review and Meta-Analysis of the Impact of Surgical Approach and Associated Risk Factors.

Surgical site infections (SSIs) represent a noteworthy contributor to both morbidity and mortality in the context of patients who undergo colorectal surgery. Several risk factors have been identified; however, their relative significance remains uncertain. We conducted a meta-analysis of observational studies from their inception up until 2023 that investigated risk factors for SSIs in colorectal surgery. A random-effects model was used to pool the data and calculate the odds ratio (OR) and 95% confidence interval (CI) for each risk factor. Our analysis included 26 studies with a total of 61,426 patients. The pooled results showed that male sex (OR = 1.45), body mass index (BMI) ≥ 25 kg/m2 (OR = 1.09), American Society of Anesthesiologists (ASA) score ≥ 3 (OR = 1.69), were all independent risk factors for SSIs in colorectal surgery. Conversely, laparoscopic surgery (OR = 0.70) was found to be a protective factor. The meta-analysis conducted revealed various risk factors, both modifiable and non-modifiable, associated with surgical site infections (SSIs) in colorectal surgery. These findings emphasize the significance of targeted interventions, including optimizing glycemic control, minimizing blood loss, and using laparoscopic techniques whenever feasible in order to decrease the occurrence of surgical site infections in this particular group of patients.

Participants’ perspectives of being recruited into a randomised trial of a weight loss intervention before colorectal cancer surgery: a qualitative interview study

BackgroundThe period between cancer diagnosis and surgery presents an opportunity for trials to assess the feasibility of behaviour change interventions. However, this can be a worrying time for patients and may hinder recruitment. We describe the perspectives of patients with excess weight awaiting colorectal cancer surgery about their recruitment into a randomised trial of a prehabilitation weight loss intervention.MethodsWe interviewed the first 26 participants from the 8 recruitment sites across England in the ‘CARE’ feasibility trial. Participants were randomised into either usual care (n = 13) or a low-energy nutritionally-replete total diet replacement programme with weekly remote behavioural support by a dietitian (n = 13). The semi-structured interviews occurred shortly after recruitment and the questions focused on participants’ recollections of being recruited into the trial. We analysed data rapidly and then used a mind-mapping technique to develop descriptive themes. Themes were agreed by all co-authors, including a person with lived-experience of colorectal surgery.ResultsParticipants had a mean body mass index (± SD) of 38 kg/m2 (± 6), age of 50 years (± 12), and 42% were female. People who participated in the trial were motivated by the offer of structured weight loss support that could potentially help them improve their surgical outcomes. However, participants also had concerns around the potential unpalatability of the intervention diet and side effects. Positive attitudes of clinicians towards the trial facilitated recruitment but participants were disappointed when they were randomised to usual care due to clinical teams’ overemphasis on the benefits of losing weight.ConclusionsPatients were motivated to take part by the prospect of improved surgical outcomes. However, the strong preference to be allocated to the intervention suggests that balanced communication of equipoise is crucial to minimise disappointment from randomisation to usual care and differential dropout from the trial.Clinical trial registrationISRCTN39207707, Registration date 13/03/2023.

Synergistic prognostic impact of hemoglobin and skeletal muscle index in patients with colorectal cancer

Background & AimsRecent studies have indicated that comorbidities such as sarcopenia and anemia can influence the prognosis of patients with colorectal cancer (CRC). However, the synergistic effects of sarcopenia and anemia on the survival of CRC patients are not yet comprehensively understood. This study aimed to investigate the relationship between anemia and sarcopenia and their synergistic effect on survival in patients with CRC. MethodsA total of 1629 patients who underwent colorectal surgery were retrospectively reviewed. Patients were categorized into four hemoglobin-sarcopenia combined classifications (HS grade) according to their hemoglobin and skeletal muscle index (SMI) levels: hemoglobin low/SMI low (HS1), hemoglobin low/SMI high (HS2), hemoglobin high/SMI low (HS3), and hemoglobin high/SMI high (HS4). Association with overall survival (OS) was analyzed using both univariable and multivariable analyses. ResultsIn total, 1024 patients with stage I-III CRC were analyzed. Patient allocation according to HS grade was 124 (12.1%) in HS1, 298 (29.1%) in HS2, 135 (13.2%) in HS3, and 467 (45.6%) in HS4. The Kaplan-Meier curves of OS showed statistically significant differences according to anemia and sarcopenia status as well as to HS grade (all P < 0.001). Univariable analysis of factors associated with OS revealed statistical significance in absence of anemia (hazard ratio [HR] 0.550, 95% confidence interval [CI] 0.400-0.756, P < 0.001], absence of sarcopenia (HR 0.560, P < 0.001), and HS grade (HS2, HR 0.515, P = 0.002; HS3, HR 0.468, P = 0.006; HS4, HR 0.325, P < 0.001). Multivariable analysis showed that compared to the HS1 group, the HS2 and HS4 groups showed significantly better OS (HS2, HR 0.527, 95% CI 0.340-0.817, P = 0.004; HS4, HR 0.574, 95% CI 0.361-0.912, P = 0.018). ConclusionsSarcopenia, characterized by a low SMI and the presence of anemia before surgery, was associated with reduced OS among patients with non-metastatic CRC.

Early Postoperative Prediction of Complications and Readmission After Colorectal Cancer Surgery Using an Artificial Neural Network.

Early predictors of postoperative complications can risk-stratify patients undergoing colorectal cancer surgery. However, conventional regression models have limited power to identify complex nonlinear relationships among a large set of variables. We developed artificial neural network models to optimize the prediction of major postoperative complications and risk of readmission in patients undergoing colorectal cancer surgery. This study aimed to develop an artificial neural network model to predict postoperative complications using postoperative laboratory values and compare the accuracy of models to standard regression methods. This retrospective study included patients who underwent elective colorectal cancer resection between January 1, 2016, and July 31, 2021. Clinical data, cancer stage, and laboratory data from postoperative days 1 to 3 were collected. Complications and readmission risk models were created using multivariable logistic regression and single-layer neural networks. National Cancer Institute-Designated Comprehensive Cancer Center. Adult patients with colorectal cancer. The accuracy of predicting postoperative major complications, readmissions, and anastomotic leaks using the area under the receiver operating characteristic curve. Neural networks had larger areas under the curve for predicting major complications compared to regression models (neural network 0.811; regression model 0.724, p < 0.001). Neural networks also showed an advantage in predicting anastomotic leak ( p = 0.036) and readmission using postoperative day 1 to 2 values ( p = 0.014). Single-center, retrospective design limited to cancer operations. In this study, we generated a set of models for the early prediction of complications after colorectal surgery. The neural network models provided greater discrimination than the models based on traditional logistic regression. These models may allow for early detection of postoperative complications as early as postoperative day 2. See the Video Abstract . ANTECEDENTES:Los predictores tempranos de complicaciones postoperatorias pueden estratificar el riesgo de los pacientes sometidos a cirugía de cáncer colorrectal. Sin embargo, los modelos de regresión convencionales tienen un poder limitado para identificar relaciones no lineales complejas entre un gran conjunto de variables. Desarrollamos modelos de redes neuronales artificiales para optimizar la predicción de complicaciones postoperatorias importantes y riesgo de reingreso en pacientes sometidos a cirugía de cáncer colorrectal.OBJETIVO:El objetivo de este estudio fue desarrollar un modelo de red neuronal artificial para predecir complicaciones postoperatorias utilizando valores de laboratorio postoperatorios y comparar la precisión de estos modelos con los métodos de regresión estándar.DISEÑO:Este estudio retrospectivo incluyó a pacientes que se sometieron a resección electiva de cáncer colorrectal entre el 1 de enero de 2016 y el 31 de julio de 2021. Se recopilaron datos clínicos, estadio del cáncer y datos de laboratorio del día 1 al 3 posoperatorio. Se crearon modelos de complicaciones y riesgo de reingreso mediante regresión logística multivariable y redes neuronales de una sola capa.AJUSTE:Instituto Nacional del Cáncer designado Centro Oncológico Integral.PACIENTES:Pacientes adultos con cáncer colorrectal.PRINCIPALES MEDIDAS DE RESULTADO:Precisión de la predicción de complicaciones mayores postoperatorias, reingreso y fuga anastomótica utilizando el área bajo la curva característica operativa del receptor.RESULTADOS:Las redes neuronales tuvieron áreas bajo la curva más grandes para predecir complicaciones importantes en comparación con los modelos de regresión (red neuronal 0,811; modelo de regresión 0,724, p < 0,001). Las redes neuronales también mostraron una ventaja en la predicción de la fuga anastomótica ( p = 0,036) y el reingreso utilizando los valores del día 1-2 postoperatorio ( p = 0,014).LIMITACIONES:Diseño retrospectivo de un solo centro limitado a operaciones de cáncer.CONCLUSIONES:En este estudio, generamos un conjunto de modelos para la predicción temprana de complicaciones después de la cirugía colorrectal. Los modelos de redes neuronales proporcionaron una mayor discriminación que los modelos basados en regresión logística tradicional. Estos modelos pueden permitir la detección temprana de complicaciones posoperatorias tan pronto como el segundo día posoperatorio. (Traducción-Dr. Mauricio Santamaria ).

273 Outcomes Reported in Elective Colorectal Cancer Surgery Research for Older Patients: A Scoping Review

Abstract Aim This scoping review aimed to identify outcome measures for assessing the impact of elective colorectal cancer surgery on older patients, given their higher surgical risk and mortality rates. Conventional surgery-specific outcomes, like 5-year mortality rates, may not be appropriate, necessitating a focus on postoperative quality of life. The challenge lies in determining optimal outcomes to assess the effects of colorectal cancer resections in the older population. Method A comprehensive literature search of major electronic databases from inception to March 2023 was conducted. Studies exploring frail or elderly individuals with colorectal cancer undergoing elective surgery and reporting postoperative outcomes were included. Outcomes were classified as surgery-specific versus person-centred and summarised using a narrative synthesis. The type and rate of surgery-specific outcomes were tabulated. Results Of 1366 identified citations, 16 studies focused on person-centred outcomes and 66 exclusively on surgery-specific outcomes. Nine of the 16 ‘person-centred outcome’ studies reported discharge destination, with home discharge being predominant. Postoperative delirium ranged from 8.2% to 18.1% in six studies. Four studies explored geriatric syndromes and three analysed activities of daily living. Three studies reported a significant improvement in quality of life. The 66 ‘surgery-specific outcome’ studies assessed mortality (N=61); length of stay (N=40); postoperative complications (N=47); readmission (N=18); reoperation (N=16); and survival (N=42). Conclusions Person-centred outcomes are underreported, despite their importance in guiding patient management. Older patients require adequate information about their recovery after surgery to manage their lives better. Future research must address this gap to improve care for older patients undergoing elective colorectal cancer surgery.

522 A Snapshot Audit of Incisional Hernia Rates Following Colorectal Cancer Resection

Abstract Aim Incisional hernia is a common complication of colorectal surgery. Recent European Hernia Society guidelines recommend strategies such as small bites closure and off-midline incisions to reduce incisional hernia rates. We aimed to evaluate our centres incisional hernia rate and performance against these categories Method All patients undergoing surgery for colorectal cancer in 2020 were included. Operative details including incision location and closure method were collected. Post-operative CT scans were assessed and correlated with clinic letters to determine presence of incisional hernia. Patients were excluded if they underwent re-operation through the midline within 12 months, or if had no imaging after 12 months. Results 118 patients were included. The incisional hernia rate was 31.4% at a mean follow-up of 24.9 months. Large bites closure (Hughes or loop PDS, n=80) had a higher incisional hernia rate compared to small bite closure ( n=38) (35.0% vs 23.6%). Incisional hernia rates were 44.1% in laparotomy incisions, 37.2% in midline extraction sites, 8% in Pfannensteil extraction sites and 0% in transverse extraction sites. Overall, IH rates in midline incisions were 40.7%, compared to 6.3% in off-midline incisions. Conclusions Incisional Hernia rates remain high following colorectal cancer surgery in our institution. Small bites closure and off-midline incisions appear to reduce this risk, but use of these techniques remains low. Work is ongoing to identify and implement strategies to improve uptake of small bites and off-midline incisions.

Plethysmography Variation Index versus Pulse Pressure Variation as an Indicator of Fluid Responsiveness in Colorectal Surgeries during Immediate Postoperative Period

Abstract Objective Goal directed fluid therapy during major abdominal surgery may reduce postoperative morbidity. The Plethysmography Variability Index (PVI), derived from the pulse oximeter waveform, has been shown to be able to predict fluid responsiveness in a number of surgical circumstances. In this study, we will compare the effectiveness and re liability of Plethysmography variation index (PPV) and Pulse pressure variation (PPV) in prediction of fluid responsiveness in all sedated intubated mechanically ventilated patients admitted for postoperative resuscitation in our surgical ICU. Method 100 patients were placed in two different groups equally where heart rate, PPV, CI, and PVI were recorded on admission. Immediately after volume expansion is performed by infusing saline 500 ml over 30 mins and at the end of volume expansion PPV, CI, PVI will be recorded every 2 hours for the first 24 hours. Results Hundred patients aged from 18 to 64 years who were scheduled for colorectal surgery and were to be transferred to the intensive care unit for postoperative care for the f irst 24 hours post operatively who didn’t have any of the exclusion criteria were included in this prospective randomized comparative single blinded research. 100 patients were divided in to “responders” and “non responders”. Both groups received a volume 500 ml saline over 30 minutes immedietly postoperatively. Fluid responsiveness was tested in both groups using PVI (Plethysmography variability index) and PPV ( pulse pressure variation) using cardiac index as a reference parameter. PVI showed accurate fluid responsiveness in comparison with PPV in responders with mean ranging from ( (-6.66 ± 0.90) and (-5.89 ± 1.93) respectively, with a P-value&amp;lt;0.01 Conclusion This study revealed that after giving a fluid challenge of 500 ml of saline over 30 minutes, a rise in PVI and PPV was demonstrated using cardiac index as a reference for reliability for comparing the effectiveness and accuracy between PVI and PPV.comparing the effectiveness and accuracy between PVI and PPV.PVI and PVI and PPV PPV can be used can be used in assessment of fluid responsiveness of the intubated ventilated sedated patients in assessment of fluid responsiveness of the intubated ventilated sedated patients with sinus rhythm in ICU, and both methods can be performed at the bedside, but with sinus rhythm in ICU, and both methods can be performed at the bedside, but PVI has advantage of being continuousPVI has advantage of being continuous, operator independent, and more reliable, operator independent, and more reliable thanthan PPVPPV.

619 Training the Trainees in Robotic Surgery – a UK Pilot Scheme

Abstract Aim Training the trainees in robotic surgery is a specialised and crucial process, given the precision and complexity involved in performing operations using robotic systems. Robotic training for trainees is challenging due to limited access to robotic systems and the lack of training opportunities. We describe how we implemented a training programme for trainees at West Hertfordshire Teaching Hospitals (WHTH) NHS Trust within a year of the consultants starting their robotics programme. Method Specialist trainees at WHTH who would have been offered training in laparoscopic surgery in colorectal, upper gastrointestinal and general surgery were selected to train as console surgeons on the CMR Surgical Versius system. All trainees had been on a first assist course and had experience in assisting in robotic surgery. Training included online modules, metrics-based virtual training, and technical skills assessment. Live operating was supervised by consultant trainers who sat beside the trainee. Results Six trainees ranging from ST4 to ST8 level were selected to partake in the training programme over a period of six months. Operations were broken down into modular parts and included segmental colectomies, anterior resections, cholecystectomy, and inguinal hernia repair. The trainees have participated in over thirty operations. Feedback from consultant trainers was given verbally and through work-based assessments. No adverse events were reported in training cases. Conclusions Robotic surgical training for specialist trainees can be implemented safely and in a timely manner. Objective metrics such as docking time, console time and volumetric hand motion may help with trainee assessment in the future.

Does chronic kidney disease affect the short-term outcomes and prognosis of colorectal cancer surgery? A propensity score matching analysis.

The aim of this study was to analyze the effect of chronic kidney disease (CKD) on the short-term outcomes and prognosis of colorectal cancer (CRC) patients who underwent primary surgery. CRC patients who underwent radical surgery were included from Jan 2011 to Jan 2020 in a single hospital. The short-term outcomes and prognosis were compared between the CKD group and the Non-CKD group using propensity score matching (PSM) analysis. A total of 4056 patients undergoing CRC surgery were included, including 723 patients in the CKD group and 3333 patients in the Non-CKD group. After 1:1 PSM, there were 666 patients in each group, respectively. No significant difference was found in baseline characteristics between the two groups. (p>0.05). After PSM, the CKD group had a longer postoperative hospital stay (P=0.009) and a higher incidence of overall complications (p=0.050). Cox analysis was performed on matched patients to find predictors of overall survival (OS) and disease-free survival (DFS). We found that age (p<0.01, HR=1.045, 95% CI=1.028-1.062), tumor stage (p<0.01, HR=1.931, 95% CI=1.564-2.385) and overall complications (p<0.01, HR=1.858, 95% CI=1.423-2.425) were independent predictors of OS. Age (p<0.01, HR=1.034, 95% CI=1.020-1.049), tumor stage (p<0.01, HR=1.852, 95% CI=1.537-2.231), and overall complications (p<0.01, HR=1.651, 95% CI=1.295-2.10) were independent predictors of DFS. However, CKD was not an independent predictor of OS or DFS (OS: p=0.619, HR=1.070, 95% CI=0.820-1.396; DFS: p=0.472, HR=1.092, 95% CI=0.859-1.389). CKD prolonged postoperative hospital stay; however, CKD might not affect major postoperative complications, OS or DFS of CRC.

Prediction of anastomotic insufficiency based on the mucosal microbiome prior to colorectal surgery: a proof-of-principle study

Anastomotic leakage (AL) is a potentially life-threatening complication following colorectal cancer (CRC) resection. In this study, we aimed to unravel longitudinal changes in microbial structure before, during, and after surgery and to determine if microbial alterations may be predictive for risk assessment between sufficient anastomotic healing (AS) and AL prior surgery. We analysed the microbiota of 134 colon mucosal biopsies with 16S rRNA V1-V2 gene sequencing. Samples were collected from three location sites before, during, and after surgery, and patients received antibiotics after the initial collection and during surgery. The microbial structure showed dynamic surgery-related changes at different time points. Overall bacterial diversity and the abundance of some genera such as Faecalibacterium or Alistipes decreased over time, while the genera Enterococcus and Escherichia_Shigella increased. The distribution of taxa between AS and AL revealed significant differences in the abundance of genera such as Prevotella, Faecalibacterium and Phocaeicola. In addition to Phocaeicola, Ruminococcus2 and Blautia showed significant differences in abundance between preoperative sample types. ROC analysis of the predictive value of these genera for AL revealed an AUC of 0.802 (p = 0.0013). In summary, microbial composition was associated with postoperative outcomes, and the abundance of certain genera may be predictive of postoperative complications.

Deep Learning-Based Real-Time Ureter Identification in Laparoscopic Colorectal Surgery.

Iatrogenic ureteral injury is a serious complication of abdominopelvic surgery. Identifying the ureters intraoperatively is essential to avoid iatrogenic ureteral injury. We developed a model that may minimize this complication. We applied a deep learning-based semantic segmentation algorithm to the ureter recognition task and developed a deep learning model called UreterNet. This study aimed to verify whether the ureters could be identified in videos of laparoscopic colorectal surgery. Semantic segmentation of the ureter area was performed using a convolutional neural network-based approach. Feature Pyramid Networks were used as the convolutional neural network architecture for semantic segmentation. Precision, recall, and the Dice coefficient were used as the evaluation metrics in this study. We created 14,069 annotated images from 304 videos, with 9537, 2266, and 2266 images in the training, validation, and test data sets, respectively. Concerning ureter recognition performance, the precision, recall, and Dice coefficient for the test data were 0.712, 0.722, and 0.716, respectively. Regarding the real-time performance on recorded videos, it took 71 milliseconds for UreterNet to infer all pixels corresponding to the ureter from a single still image and 143 milliseconds to output and display the inferred results as a segmentation mask on the laparoscopic monitor. UreterNet is a noninvasive method for identifying the ureter in videos of laparoscopic colorectal surgery and can potentially improve surgical safety. Although this deep learning model could lead to the development of an image-navigated surgical system, it is necessary to verify whether UreterNet reduces the occurrence of iatrogenic ureteral injury.

The Learning Curve for Robotic Lateral Pelvic Lymph Node Dissection for Rectal Cancer: A View from the West.

Lateral pelvic lymph-node dissection is performed for selected patients with rectal cancer with persistent lateral nodal disease after neoadjuvant therapy. This technique has been slow to be adopted in the West due to concerns regarding technical difficulty. This is the first report on the learning curve for lateral pelvic lymph node dissection in the US or Europe. The aim of this study was to analyze the learning curve associated with robotic lateral pelvic lymph node dissection. Retrospective observational cohort. Tertiary academic cancer center. Consecutive patients from 2012 to 2021. All patients underwent robotic lateral pelvic lymph node dissection. The primary endpoints were the learning curves for maximum number of nodes retrieved and urinary retention which was evaluated with simple cumulative-sum and two-sided Bernoulli cumulative-sum charts. Fifty-four procedures were included. A single-surgeon (n = 35) and an institutional learning curve are presented in the analysis. In the single-surgeon learning curve, a turning point marking the end of a learning phase was detected at the 12th procedure for the number of retrieved nodes and at the 20th for urinary retention. In the institutional learning curve analysis, two turning points were identified at the 13th and 26th procedures indicating progressive improvements for the number of retrieved nodes and at the 27th for urinary retention. No sustained alarm signals were detected at any time point. The retrospective nature, small sample size and the referral center nature of the reporting institution that may limit generalizability. In a setting of institutional experience with robotic colorectal surgery including beyond TME resections, the learning curve for robotic lateral pelvic lymph node dissection is acceptably short. Our results demonstrate feasibility of acquisition of this technique in a controlled setting, with sufficient case volume and proctoring can optimize the learning curve. See Video Abstract.

Comparison of two bundles for reducing surgical site infection in colorectal surgery: multicentre cohort study.

There is controversy regarding the maximum number of elements that can be included in a surgical site infection prevention bundle. In addition, it is unclear whether a bundle of this type can be implemented at a multicentre level. A pragmatic, multicentre cohort study was designed to analyse surgical site infection rates in elective colorectal surgery after the sequential implementation of two preventive bundle protocols. Secondary outcomes were to determine compliance with individual measures and to establish their effectiveness, duration of stay, microbiology and 30-day mortality rate. A total of 32 205 patients were included. A 50% reduction in surgical site infection was achieved after the implementation of two sequential sets of bundles: from 18.16% in the Baseline group to 10.03% with Bundle-1 and 8.19% with Bundle-2. Bundle-2 reduced superficial-surgical site infection (OR 0.74 (95% c.i. 0.58 to 0.95); P = 0.018) and deep-surgical site infection (OR 0.66 (95% c.i. 0.46 to 0.93); P = 0.018) but not organ/space-surgical site infection (OR 0.88 (95% c.i. 0.74 to 1.06); P = 0.172). Compliance increased after the addition of four measures to Bundle-2. In the multivariable analysis, for organ/space-surgical site infection, laparoscopy, oral antibiotic prophylaxis and mechanical bowel preparation were protective factors in colonic procedures, while no protective factors were found in rectal surgery. Duration of stay fell significantly over time, from 7 in the Baseline group to 6 and 5 days for Bundle-1 and Bundle-2 respectively (P < 0.001). The mortality rate fell from 1.4% in the Baseline group to 0.59% and 0.6% for Bundle-1 and Bundle-2 respectively (P < 0.001). There was an increase in Gram-positive bacteria and yeast isolation, and reduction in Gram-negative bacteria and anaerobes in organ/space-surgical site infection. The addition of measures to create a final 10-measure protocol had a cumulative protective effect on reducing surgical site infection. However, organ/space-surgical site infection did not benefit from the addition. No protective measures were found for organ/space-surgical site infection in rectal surgery. Compliance with preventive measures increased from Bundle-1 to Bundle-2.

Suprapubic versus transurethral catheterization for bladder drainage in male rectal cancer surgery (GRECCAR10), a randomized clinical trial.

Bladder drainage is systematically used in rectal cancer surgery; however, the optimal type of drainage, transurethral catheterization (TUC) or suprapubic catheterization (SPC), is still controversial. The aim was to compare the rates of urinary tract infection on the fourth postoperative day (POD4) between TUC and SPC, after rectal cancer surgery regardless of the day of removal of the urinary drain. This randomized clinical trial in 19 expert colorectal surgery centers in France and Belgium was performed between October 2016 and October 2019 and included 240 men (with normal or subnormal voiding function) undergoing mesorectal excision with low anastomosis for rectal cancer. Patients were followed at postoperative days4, 30, and 180. In 208 patients (median age 66years [IQR 58-71]) randomized to TUC (n = 99) or SPC (n = 109), the rate of urinary infection at POD4 was not significantly different whatever the type of drainage (11/99 (11.1%) vs. 8/109 (7.3%), 95%CI, - 4.2% to 11.7%; p = 0.35). There was significantly more pyuria in the TUC group (79/99 (79.0%) vs. (60/109 (60.9%), 95%CI, 5.7-30.0%; p = 0.004). No difference in bacteriuria was observed between the groups. Patients in the TUC group had a shorter duration of catheterization (median 4 [2-5] vs. 4 [3-5] days; p = 0.002). Drainage complications were more frequent in the SPC group at all followup visits. TUC should be preferred over SPC in male patients undergoing surgery for mid and/or lower rectal cancers, owing to the lower rate of complications and shorter duration of catheterization. ClinicalTrials.gov identifier NCT02922647.

Update on the management of pT1 colorectal cancer

Abstract With the implementation of CRC screening programs, the incidence of pT1 CRC has increased significantly: up to 40% of colon tumors detected in screening colonoscopies are pT1. Traditionally, the treatment of choice for CRC is surgery with lymph node resection, but pT1 CRC has a very good prognosis with 5-year disease-free survival rates greater than 90% and thanks to advanced endoscopy, it can be treated locally with a minimally invasive approach in many cases. After resection of the lesion, an adequate histological description of the specimen will guide us to make the final decision in the management of pT1 CRC: whether endoscopic resection is considered curative or whether additional surgery will be required to prevent local recurrence, lymphatic dissemination and /or distant metastasis. The decision to proceed with additional surgery or surveillance depends primarily on the estimated oncologic benefit of surgery, operative risk, and patient preferences. It must be taken into account that colorectal surgery carries a significant risk of morbidity and mortality for elderly patients. Currently we base our decisions on histological criteria, but the natural history of pT1 CRC resected by endoscopy is really unknown and there are not enough quality prospective studies with results after long-term follow-up of pT1 CRC non-surgically managed, especially in the case of high-risk pT1, which would explain the great variability in the management of these patients. In this thematic review we have analyzed the current state of management of pT1 CRC in the field of endoscopic diagnosis and treatment, histological evaluation and its prognostic implications. We have also reviewed the most recent evidence regarding surveillance: how to carry out adequate follow-up and determine the optimal frequency and the most appropriate surveillance method after local resection of pT1 CRC.

Microbiologic Evaluation of Colorectal Surgical Site Infections to Guide Surgical Prophylaxis Recommendations

Background: Use of a combination of parenteral and oral antimicrobial prophylaxis prior to colorectal surgery is recommended to reduce risk of surgical site infection (SSI). Parenteral antibiotic selection is complicated by the need to target organisms likely to cause infection at the surgery site, while mitigating risk of antimicrobial resistance caused by overuse of broad spectrum agents. This study aimed to evaluate microbiologic data from colorectal surgical site infections across an 11-hospital health system. Microbiologic data from SSI events were used to assess continued appropriateness of health system standard recommendations for parenteral antibiotic prophylaxis in colorectal surgery, consisting of either cefazolin with metronidazole or cefoxitin monotherapy. Methods: This multicenter, retrospective, observational study was conducted from January 1, 2019 to March 31, 2023, using data extracted from the National Healthcare Safety Network (NHSN). Microbiologic data from colorectal SSIs from 2019 to 2022 were evaluated for a descriptive review of pathogen and phenotype trends. SSI data excluded patients age &lt; 18 years, those identified as infection present at time of surgery (PATOS), or outpatient procedures. Results: A total of 8059 colorectal procedures were evaluated. Most SSIs were polymicrobial, with at least one pathogen detected in 65% of cases. The most commonly identified organisms were E. coli (22.5%), Enterococcus spp. (19.7%), P. aeruginosa (6.5%), Streptococcus spp. (4.9%), and C. albicans (4.7%). Change over time in antimicrobial-resistant phenotypes from 2019 to 2022 was not statistically significant for extended-spectrum cephalosporin-resistant E. coli (p=0.335), extended-spectrum cephalosporin-resistant K. oxytoca/pneumoniae (p=0.189), multi-drug resistant P. aeruginosa (0.058), methicillin-resistant S. aureus (p=0.906), or among isolates with no identified antimicrobial-resistance phenotype (p=0.096). Among E. coli, change from 2019 to 2022 in cefazolin non-susceptible, ceftriaxone susceptible isolates was not statistically significant (p=0.177). No carbapenem-resistant Enterobacterales isolates were identified among non-PATOS cases. Conclusions: Data does not support a change to broader spectrum agents for colorectal surgery parenteral antimicrobial prophylaxis. Continued use of cefazolin with metronidazole or cefoxitin as IV antibiotic prophylaxis in colorectal surgery is recommended, with ongoing tracking of microbiologic trends and antimicrobial susceptibility.

Robotic approach to colonic resection: For some or for all patients?

The robotic approach is rapidly gaining momentum in colorectal surgery. Its benefits in pelvic surgery have been extensively discussed and are well established amongst those who perform minimally invasive surgery. However, the same cannot be said for the robotic approach for colonic resection, where its role is still debated. Here we aim to provide an extensive debate between selective and absolute use of the robotic approach for colonic resection by combining the thoughts of experts in the field of robotic and minimally invasive colorectal surgery, dissecting all key aspects for a critical view on this exciting new paradigm in colorectal surgery.