Predicting the risk of anastomotic leakage in left-sided colorectal surgery using a colon leakage score

Machine learning-based preoperative analytics for the prediction of anastomotic leakage in colorectal surgery: a swiss pilot study

BACKGROUND

Anastomotic leakage (AL), a severe complication following colorectal surgery, arises from defects at the anastomosis site. This study evaluates the feasibility of predicting AL using machine learning (ML) algorithms based on preoperative data.

METHODS

We retrospectively analyzed data including 21 predictors from patients undergoing colorectal surgery with bowel anastomosis at four Swiss hospitals. Several ML algorithms were applied for binary classification into AL or non-AL groups, utilizing a five-fold cross-validation strategy with a 90% training and 10% validation split. Additionally, a holdout test set from an external hospital was employed to assess the models' robustness in external validation.

RESULTS

Among 1244 patients, 112 (9.0%) suffered from AL. The Random Forest model showed an AUC-ROC of 0.78 (SD: ± 0.01) on the internal test set, which significantly decreased to 0.60 (SD: ± 0.05) on the external holdout test set comprising 198 patients, including 7 (3.5%) with AL. Conversely, the Logistic Regression model demonstrated more consistent AUC-ROC values of 0.69 (SD: ± 0.01) on the internal set and 0.61 (SD: ± 0.05) on the external set. Accuracy measures for Random Forest were 0.82 (SD: ± 0.04) internally and 0.87 (SD: ± 0.08) externally, while Logistic Regression achieved accuracies of 0.81 (SD: ± 0.10) and 0.88 (SD: ± 0.15). F1 Scores for Random Forest moved from 0.58 (SD: ± 0.03) internally to 0.51 (SD: ± 0.03) externally, with Logistic Regression maintaining more stable scores of 0.53 (SD: ± 0.04) and 0.51 (SD: ± 0.02).

CONCLUSION

In this pilot study, we evaluated ML-based prediction models for AL post-colorectal surgery and identified ten patient-related risk factors associated with AL. Highlighting the need for multicenter data, external validation, and larger sample sizes, our findings emphasize the potential of ML in enhancing surgical outcomes and inform future development of a web-based application for broader clinical use.

Reduced preoperative serum choline esterase levels and fecal peritoneal contamination as potential predictors for the leakage of intestinal sutures after source control in secondary peritonitis

BACKGROUND

The high rate of stoma placement during emergency laparotomy for secondary peritonitis is a paradigm in need of change in the current fast-track surgical setting. Despite growing evidence for the feasibility of primary bowel reconstruction in a peritonitic environment, little data substantiate a surgeons' choice between a stoma and an anastomosis. The aim of this retrospective analysis is to identify pre- and intraoperative parameters that predict the leakage risk for enteric sutures placed during source control surgery (SCS) for secondary peritonitis.

METHODS

Between January 2014 and December 2020, 497 patients underwent SCS for secondary peritonitis, of whom 187 received a primary reconstruction of the lower gastro-intestinal tract without a diverting stoma. In 47 (25.1%) patients postoperative leakage of the enteric sutures was directly confirmed during revision surgery or by computed tomography. Quantifiable predictors of intestinal suture outcome were detected by multivariate analysis.

RESULTS

Length of intensive care, in-hospital mortality and failure of release to the initial home environment were significantly higher in patients with enteric suture leakage following SCS compared to patients with intact anastomoses (p < 0.0001, p = 0.0026 and p =0.0009, respectively). Reduced serum choline esterase (sCHE) levels and a high extent of peritonitis were identified as independent risk factors for insufficiency of enteric sutures placed during emergency laparotomy.

CONCLUSIONS

A preoperative sCHE < 4.5 kU/L and generalized fecal peritonitis associate with a significantly higher incidence of enteric suture insufficiency after primary reconstruction of the lower gastro-intestinal tract in a peritonitic abdomen. These parameters may guide surgeons when choosing the optimal surgical procedure in the emergency setting.

Procalcitonin and C-reactive protein as early predictors in patients at high risk of colorectal anastomotic leakage

OBJECTIVE

To assess the diagnostic value of C-reactive protein (CRP) and procalcitonin (PCT) for anastomotic leakage (AL) following colorectal surgery.

METHODS

We retrospectively analyzed data for patients who underwent colorectal surgery at our hospital between November 2019 and December 2023. CRP and PCT were measured postoperatively to compare patients with/without AL, and changes were compared between low- and high-risk groups. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic accuracy of CRP and PCT to identify AL in high-risk patients.

RESULTS

Mean CRP was 142.53 mg/L and 189.57 mg/L in the low- and high-risk groups, respectively, on postoperative day (POD)3. On POD2, mean PCT was 2.75 ng/mL and 8.16 ng/mL in low- and high-risk patients, respectively; values on POD3 were 3.53 ng/mL and 14.86 ng/mL, respectively. The areas under the curve (AUC) for CRP and PCT on POD3 were 0.71 and 0.78, respectively (CRP cut-off: 235.64 mg/L; sensitivity: 96%; specificity: 89.42% vs PCT cut-off: 3.94 ng/mL; sensitivity: 86%; specificity: 93.56%; AUC: 0.78). The AUC, sensitivity, and specificity for the combined diagnostic ability of CRP and PCT on POD3 were 0.92, 90%, and 100%, respectively (cut-off: 0.44).

CONCLUSIONS

Combining PCT and CRP on POD3 enhances the diagnostic accuracy for AL.

Score prediction of anastomotic leak in colorectal surgery: a systematic review

OBJECTIVE

Predicting the risk of anastomotic leak (AL) is of importance when defining the optimal surgical strategy in colorectal surgery. Our objective was to perform a systematic review of existing scores in the field.

METHODS

We followed the PRISMA checklist (S1 Checklist). Medline, Cochrane Central and Embase were searched for observational studies reporting on scores predicting AL after the creation of a colorectal anastomosis. Studies reporting only validation of existing scores and/or scores based on post-operative variables were excluded. PRISMA 2020 recommendations were followed. Qualitative analysis was performed.

RESULTS

Eight hundred articles were identified. Seven hundred and ninety-one articles were excluded after title/abstract and full-text screening, leaving nine studies for analysis. Scores notably included the Colon Leakage Score, the modified Colon Leakage Score, the REAL score, www.anastomoticleak.com and the PROCOLE score. Four studies (44.4%) included more than 1.000 patients and one extracted data from existing studies (meta-analysis of risk factors). Scores included the following pre-operative variables: age (44.4%), sex (77.8%), ASA score (66.6%), BMI (33.3%), diabetes (22.2%), respiratory comorbidity (22.2%), cardiovascular comorbidity (11.1%), liver comorbidity (11.1%), weight loss (11.1%), smoking (33.3%), alcohol consumption (33.3%), steroid consumption (33.3%), neo-adjuvant treatment (44.9%), anticoagulation (11.1%), hematocrit concentration (22.2%), total proteins concentration (11.1%), white blood cell count (11.1%), albumin concentration (11.1%), distance from the anal verge (77.8%), number of hospital beds (11.1%), pre-operative bowel preparation (11.1%) and indication for surgery (11.1%). Scores included the following peri-operative variables: emergency surgery (22.2%), surgical approach (22.2%), duration of surgery (66.6%), blood loss/transfusion (55.6%), additional procedure (33.3%), operative complication (22.2%), wound contamination class (1.11%), mechanical anastomosis (1.11%) and experience of the surgeon (11.1%). Five studies (55.6%) reported the area under the curve (AUC) of the scores, and four (44.4%) included a validation set.

CONCLUSION

Existing scores are heterogeneous in the identification of pre-operative variables allowing predicting AL. A majority of scores was established from small cohorts of patients which, considering the low incidence of AL, might lead to miss potential predictors of AL. AUC is seldom reported. We recommend that new scores to predict the risk of AL in colorectal surgery to be based on large cohorts of patients, to include a validation set and to report the AUC.

Explainable Model Using Shapley Additive Explanations Approach on Wound Infection after Wide Soft Tissue Sarcoma Resection: "Big Data" Analysis Based on Health Insurance Review and Assessment Service Hub

Background and Objectives: Soft tissue sarcomas represent a heterogeneous group of malignant mesenchymal tissues. Despite their low prevalence, soft tissue sarcomas present clinical challenges for orthopedic surgeons owing to their aggressive nature, and perioperative wound infections. However, the low prevalence of soft tissue sarcomas has hindered the availability of large-scale studies. This study aimed to analyze wound infections after wide resection in patients with soft tissue sarcomas by employing big data analytics from the Hub of the Health Insurance Review and Assessment Service (HIRA). Materials and Methods: Patients who underwent wide excision of soft tissue sarcomas between 2010 and 2021 were included. Data were collected from the HIRA database of approximately 50 million individuals' information in the Republic of Korea. The data collected included demographic information, diagnoses, prescribed medications, and surgical procedures. Random forest has been used to analyze the major associated determinants. A total of 10,906 observations with complete data were divided into training and validation sets in an 80:20 ratio (8773 vs. 2193 cases). Random forest permutation importance was employed to identify the major predictors of infection and Shapley Additive Explanations (SHAP) values were derived to analyze the directions of associations with predictors. Results: A total of 10,969 patients who underwent wide excision of soft tissue sarcomas were included. Among the study population, 886 (8.08%) patients had post-operative infections requiring surgery. The overall transfusion rate for wide excision was 20.67% (2267 patients). Risk factors among the comorbidities of each patient with wound infection were analyzed and dependence plots of individual features were visualized. The transfusion dependence plot reveals a distinctive pattern, with SHAP values displaying a negative trend for individuals without blood transfusions and a positive trend for those who received blood transfusions, emphasizing the substantial impact of blood transfusions on the likelihood of wound infection. Conclusions: Using the machine learning random forest model and the SHAP values, the perioperative transfusion, male sex, old age, and low SES were important features of wound infection in soft-tissue sarcoma patients.

Prediction of symptomatic anastomotic leak after rectal cancer surgery: A machine learning approach

INTRODUCTION

Anastomotic leakage (AL) remains the most dreaded and unpredictable major complication after low anterior resection for mid-low rectal cancer. The aim of this study is to identify patients with high risk for AL based on the machine learning method.

METHODS

Patients with mid-low rectal cancer undergoing low anterior resection were enrolled from West China Hospital between January 2008 and October 2019 and were split by time into training cohort and validation cohort. The least absolute shrinkage and selection operator (LASSO) method and stepwise method were applied for variable selection and predictive model building in the training cohort. The area under the receiver operating characteristic curve (AUC) and calibration curves were used to evaluate the performance of the models.

RESULTS

The rate of AL was 5.8% (38/652) and 7.2% (15/208) in the training cohort and validation cohort, respectively. The LASSO-logistic model selected almost the same variables (hypertension, operating time, cT4, tumor location, intraoperative blood loss) compared to the stepwise logistic model except for tumor size (the LASSO-logistic model) and American Society of Anesthesiologists score (the stepwise logistic model). The predictive performance of the LASSO-logistics model was better than the stepwise-logistics model (AUC: 0.790 vs. 0.759). Calibration curves showed mean absolute error of 0.006 and 0.013 for the LASSO-logistics model and stepwise-logistics model, respectively.

CONCLUSION

Our study developed a feasible predictive model with a machine-learning algorithm to classify patients with a high risk of AL, which would assist surgical decision-making and reduce unnecessary stoma diversion. The involved machine learning algorithms provide clinicians with an innovative alternative to enhance clinical management.

Consensus Guidelines for Perioperative Care for Emergency Laparotomy Enhanced Recovery After Surgery (ERAS®) Society Recommendations Part 2-Emergency Laparotomy: Intra- and Postoperative Care

BACKGROUND

This is Part 2 of the first consensus guidelines for optimal care of patients undergoing emergency laparotomy (EL) using an Enhanced Recovery After Surgery (ERAS) approach. This paper addresses intra- and postoperative aspects of care.

METHODS

Experts in aspects of management of high-risk and emergency general surgical patients were invited to contribute by the International ERAS® Society. PubMed, Cochrane, Embase, and Medline database searches were performed for ERAS elements and relevant specific topics. Studies on each item were selected with particular attention to randomized clinical trials, systematic reviews, meta-analyses, and large cohort studies and reviewed and graded using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Recommendations were made on the best level of evidence, or extrapolation from studies on elective patients when appropriate. A modified Delphi method was used to validate final recommendations. Some ERAS® components covered in other guideline papers are outlined only briefly, with the bulk of the text focusing on key areas pertaining specifically to EL.

RESULTS

Twenty-three components of intraoperative and postoperative care were defined. Consensus was reached after three rounds of a modified Delphi Process.

CONCLUSIONS

These guidelines are based on best available evidence for an ERAS® approach to patients undergoing EL. These guidelines are not exhaustive but pull together evidence on important components of care for this high-risk patient population. As much of the evidence is extrapolated from elective surgery or emergency general surgery (not specifically laparotomy), many of the components need further evaluation in future studies.

Management of Anastomotic Leakage after Colorectal Resection: Survey among the German CHIR-Net Centers

(1) Background: A widely accepted algorithm for the management of colorectal anastomotic leakage (CAL) is difficult to establish. The present study aimed to evaluate the current clinical practice on the management of CAL among the German CHIR-Net centers. (2) Methods: An online survey of 38 questions was prepared using the International Study Group of Rectal Cancer (ISREC) grading score of CAL combined with both patient- and surgery-related factors. All CHIR-Net centers received a link to the online questionary in February 2020. (3) Results: Most of the answering centers (55%) were academic hospitals (41%). Only half of them use the ISREC definition and grading for the management of CAL. A preference towards grade B management (no surgical intervention) of CAL was observed in both young and fit as well as elderly and/or frail patients with deviating ostomy and non-ischemic anastomosis. Elderly and/or frail patients without fecal diversion are generally treated as grade C leakage (surgical intervention). A grade C management of CAL is preferred in case of ischemic bowel, irrespective of the presence of an ostomy. Within grade C management, the intestinal continuity is preserved in a subgroup of patients with non-ischemic bowel, with or without ostomy, or young and fit patients with ischemic bowel under ostomy protection. (4) Conclusions: There is no generally accepted therapy algorithm for CAL management within CHIR-Net Centers in Germany. Further effort should be made to increase the application of the ISREC definition and grading of CAL in clinical practice.

Systematic review of preoperative and intraoperative colorectal Anastomotic Leak Prediction Scores (ALPS)

OBJECTIVE

To systematically review preoperative and intraoperative Anastomotic Leak Prediction Scores (ALPS) and validation studies to evaluate performance and utility in surgical decision-making. Anastomotic leak (AL) is the most feared complication of colorectal surgery. Individualised leak risk could guide anastomosis and/or diverting stoma.

METHODS

Systematic search of Ovid MEDLINE and Embase databases, 30 October 2020, identified existing ALPS and validation studies. All records including >1 risk factor, used to develop new, or to validate existing models for preoperative or intraoperative use to predict colorectal AL, were selected. Data extraction followed CHecklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling Studies guidelines. Models were assessed for applicability for surgical decision-making and risk of bias using Prediction model Risk Of Bias ASsessment Tool.

RESULTS

34 studies were identified containing 31 individual ALPS (12 colonic/colorectal, 19 rectal) and 6 papers with validation studies only. Development dataset patient populations were heterogeneous in terms of numbers, indication for surgery, urgency and stoma inclusion. Heterogeneity precluded meta-analysis. Definitions and timeframe for AL were available in only 22 and 11 ALPS, respectively. 26/31 studies used some form of multivariable logistic regression in their modelling. Models included 3-33 individual predictors. 27/31 studies reported model discrimination performance but just 18/31 reported calibration. 15/31 ALPS were reported with external validation, 9/31 with internal validation alone and 4 published without any validation. 27/31 ALPS and every validation study were scored high risk of bias in model analysis.

CONCLUSIONS

Poor reporting practices and methodological shortcomings limit wider adoption of published ALPS. Several models appear to perform well in discriminating patients at highest AL risk but all raise concerns over risk of bias, and nearly all over wider applicability. Large-scale, precisely reported external validation studies are required.

PROSPERO REGISTRATION NUMBER

CRD42020164804.

Short-Term Outcomes in Patients Undergoing Virtual/Ghost Ileostomy or Defunctioning Ileostomy after Anterior Resection of the Rectum: A Meta-Analysis

BACKGROUND AND OBJECTIVES

Anterior rectal resection (ARR) represents one of the most frequently performed methods in colorectal surgery, mainly carried out for rectal cancer (RC) treatment. Defunctioning ileostomy (DI) has long been chosen as a method to "protect" colorectal or coloanal anastomosis after ARR. However, DI does not rule out risks of more or less serious complications. A proximal intra-abdominal closed-loop ileostomy, the so-called virtual/ghost ileostomy (VI/GI), could limit the number of DIs and the associated morbidity.

MATERIALS AND METHODS

We performed a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) guidelines. Meta-analysis was performed by use of RevMan [Computer program] Version 5.4.

RESULTS

The five included comparative studies (VI/GI or DI) covering an approximately 20-year study period (2008-2021). All included studies were observational ones and originated from European countries. Meta-analysis indicated VI/GI as significantly associated with lower short-term morbidity rates related to VI/GI or DI after primary surgery (RR: 0.21, 95% CI: 0.07-0.64, p = 0.006), fewer dehydration (RR: 0.17, 95% CI: 0.04-0.75, p = 0.02) and ileus episodes after primary surgery (RR: 0.20, 95% CI: 0.05-0.77, p = 0.02), fewer readmissions after primary surgery (RR: 0.17, 95% CI: 0.07-0.43, p = 0.0002) and readmissions after primary surgery plus stoma closure surgery (RR: 0.14, 95% CI: 0.06-0.30, p < 0.00001) than the DI group. On the contrary, no differences were identified in terms of AL after primary surgery, short-term morbidity after primary surgery, major complications (CD ≥ III) after primary surgery and length of hospital stay after primary surgery. Conclusions: Given the significant biases among meta-analyzed studies (small overall sample size and the small number of events analyzed, in particular), our results require careful interpretation. Further randomized, possibly multi-center trials may be of paramount importance in confirming our results.

Fluid management and vasopressor use during colorectal surgery: the search for the optimal balance

BACKGROUND

Although it is known that excessive intraoperative fluid and vasopressor agents are detrimental for anastomotic healing, optimal anesthesiology protocols for colorectal surgery are currently lacking.

OBJECTIVE

To scrutinize the current hemodynamic practice and vasopressor use and their relation to colorectal anastomotic leakage.

DESIGN

A secondary analysis of a previously published prospective observational study: the LekCheck study.

STUDY SETTING

Adult patients undergoing a colorectal resection with the creation of a primary anastomosis.

OUTCOME MEASURES

Colorectal anastomotic leakage (CAL) within 30 days postoperatively, hospital length of stay and 30-day mortality.

RESULTS

Of the 1548 patients, 579 (37%) received vasopressor agents during surgery. Of these, 201 were treated with solely noradrenaline, 349 were treated with phenylephrine, and 29 received ephedrine. CAL rate significantly differed between the patients receiving vasopressor agents during surgery compared to patients without (11.8% vs 6.3%, p < 0.001). CAL was significantly higher in the group receiving phenylephrine compared to noradrenaline (14.3% vs 6%, p < 0.001). Vasopressor agents were used more often in patients treated with Goal Directed Therapy (47% vs 34.6%, p < 0.001). There was a higher mortality rate in patients with vasopressors compared to the group without (2.8% vs 0.4%, p = 0.01, OR 3.8). Mortality was higher in the noradrenaline group compared to the phenylephrine and those without vasopressors (5% vs. 0.4% and 1.7%, respectively, p < 0.001). In multivariable analysis, patients with intraoperative vasopressor agents had an increased risk to develop CAL (OR 2.1, CI 1.3-3.2, p = 0.001).

CONCLUSION

The present study contributes to the evidence that intraoperative use of vasopressor agents is associated with a higher rate of CAL. This study helps to create awareness on the (necessity to) use of vasopressor agents in colorectal surgery patients in striving for successful anastomotic wound healing. Future research will be required to balance vasopressor agent dosage in view of colorectal anastomotic leakage.

Effect of reinforcement suture on anastomotic healing in rectal and sigmoid tumor resections, single-center experience: a retrospective case-controlled study

PURPOSE

Healing of colorectal anastomosis is burdened with a number of risk factors and the development of leak carries with it higher morbidity and mortality associated not only with worse quality of life but also worse oncological outcomes. The purpose of the study was an evaluation of the effect of reinforcement suture in the healing of stapler rectal anastomosis and risk factors for anastomotic leakage in mid, upper rectal and sigmoid tumors.

METHODS

A total of 357 patients who underwent curative resection for rectal or sigmoid tumor over 5 years were analyzed. Risk factors, baseline demographic and clinical data, and presence of leak were recorded. All statistical analyses were carried out at a significance level of P<0.05.

RESULTS

One hundred fifty-one patients met the inclusion criteria for the study. The overall incidence of leak was 2.8% in the group with reinforcement suture and 6.3% in the group without reinforcement suture. Because of the low incidence of leak the results were not statistically significant. Further results also show that none of the monitored parameters (age, weight, body mass index, tumor distance, preoperative radiotherapy, tumor stage, type of surgery) were significant predictors of anastomotic leakage.

CONCLUSION

Although the reinforcement suture is a safe and simple option for anastomosis protection after rectal or sigmoid resections, its statistical significance was not demonstrated in our study.

Predictive Factors for Anastomotic Leakage Following Colorectal Cancer Surgery: Where Are We and Where Are We Going?

Anastomotic leakage (AL) remains one of the most severe complications following colorectal cancer (CRC) surgery. Indeed, leaks that may occur after any type of intestinal anastomosis are commonly associated with a higher reoperation rate and an increased risk of postoperative morbidity and mortality. At first, our review aims to identify specific preoperative, intraoperative and perioperative factors that eventually lead to the development of anastomotic dehiscence based on the current literature. We will also investigate the role of several biomarkers in predicting the presence of ALs following colorectal surgery. Despite significant improvements in perioperative care, advances in surgical techniques, and a high index of suspicion of this complication, the incidence of AL remained stable during the last decades. Thus, gaining a better knowledge of the risk factors that influence the AL rates may help identify high-risk surgical patients requiring more intensive perioperative surveillance. Furthermore, prompt diagnosis of this severe complication may help improve patient survival. To date, several studies have identified predictive biomarkers of ALs, which are most commonly associated with the inflammatory response to colorectal surgery. Interestingly, early diagnosis and evaluation of the severity of this complication may offer a significant opportunity to guide clinical judgement and decision-making.

Inter-Rater Agreement of the Classification of Intraoperative Adverse Events (ClassIntra) in Abdominal Surgery

OBJECTIVE AND SUMMARY OF BACKGROUND DATA

Adverse events in surgical patients can occur preoperatively, intraoperatively, and postoperatively. Universally accepted classification systems are not yet available for intraoperative adverse events (iAEs). ClassIntra has recently been developed and validated as a tool for grading iAEs that occur between skin incision and skin closure irrespective of the origin, that is, surgery, anesthesia, or organizational. The aim of this study is to assess the inter-rater agreement of ClassIntra and assess its predictive value for postoperative complications in elective abdominal surgery.

METHODS

This study is a secondary use of data from the LAParotomy or LAParoscopy and ADhesiolysis (LAPAD) study, with detailed data on incidence and management of intra-operative and post-operative complications. Data were collected in a cohort of elective abdominal surgeries. Two teams graded all recorded events in the LAPAD study according to ClassIntra. Cohen Kappa coefficient was calculated to determine inter-rater agreement. Uni- and multivariable linear regression was used to assess the predictive value of the ClassIntra grades for postoperative complications.

RESULTS

IAEs were rated in 333 of 755 (44%) surgeries by team 1, and in 324 of 755 (43%) surgeries by team 2. Cohen kappa coefficient for ClassIntra grades was 0.87 [95% confidence interval (CI) 0.84-0.90]. Discrepancies in grading were most frequent for intraoperative bleeding and adhesions' associated injuries. At least 1 postoperative complication was observed in 278 (37%) patients. The risk of a postoperative complications increased with every increase in severity grade of ClassIntra. Intraoperative hypotension [mean difference (MD) 23.41, 95% CI 12.93-33.90] and other organ injuries (MD 18.90, 95% CI -4.22 - 42.02) were the strongest predictors for postoperative complications.

CONCLUSIONS

ClassIntra has an almost perfect inter-rater agreement for the classification of iAEs. An increasing grade of ClassIntra was associated with a higher incidence of postoperative complications. Discrepancies in grading related to common complications in abdominal procedures mostly consisted of intraoperative bleeding and adhesion-related injuries. Grading of interoperative events in abdominal surgery might further improve by consensus regarding the definitions of a number of frequent events.

Protective ileostomy creation after anterior resection of the rectum: Shared decision-making or still subjective?

AIM

The choice of whether to perform protective ileostomy (PI) after anterior resection (AR) is mainly guided by risk factors (RFs) responsible for the development of anastomotic leakage (AL). However, clear guidelines about PI creation are still lacking in the literature and this is often decided according to the surgeon's preferences, experiences or feelings. This qualitative study aims to investigate, by an open-ended question survey, the individual surgeon's decision-making process regarding PI creation after elective AR.

METHOD

Fifty four colorectal surgeons took part in an electronic survey to answer the questions and describe what usually led their decision to perform PI. A content analysis was used to code the answers. To classify answers, five dichotomous categories (In favour/Against PI, Listed/Unlisted RFs, Typical/Atypical, Emotions/Non-emotions, Personal experience/No personal experience) have been developed.

RESULTS

Overall, 76% of surgeons were in favour of PI creation and 88% considered listed RFs in the question of whether to perform PI. Atypical answers were reported in 10% of cases. Emotions and personal experience influenced surgeons' decision-making process in 22% and 49% of cases, respectively. The most frequently considered RFs were the distance of the anastomosis from the anal verge (96%), neoadjuvant chemoradiotherapy (88%), a positive intraoperative leak test (65%), blood loss (37%) and immunosuppression therapy (35%).

CONCLUSION

The indications to perform PI following rectal cancer surgery lack standardization and evidence-based guidelines are required to inform practice. Until then, expert opinion can be helpful to assist the decision-making process in patients who have undergone AR for adenocarcinoma.

Is a Defunctioning Stoma Necessary After Left Colectomy in High-risk Patients for Anastomotic Leak?

INTRODUCTION

Left colectomy is associated with a 7% risk of anastomotic leak. In 2011, a prediction score for AL [the colon leakage score (CLS)] was developed. The aim was to evaluate the impact of a defunctioning stoma on AL and its consequences after left colectomy in high-risk patients.

PATIENTS

From January 2012 to June 2019, high-risk patients who underwent a left colectomy with anastomosis were included in this retrospective, single-center study. Two groups of patients were defined: patients undergoing a left colectomy with an anastomosis without a defunctioning stoma (no-stoma group) and those with a defunctioning stoma (stoma group). The primary endpoint was the rate of anastomotic leakage.

RESULTS

Ninety-two patients were included in this study. The anastomotic leakage rate was 16.4% in the no-stoma group and 21.6% in the stoma group ( P =0.5). A conservative approach was applied to 11.2% in the no-stoma group and 50% in the stoma group ( P =0.1). The severe morbidity rate was 14.5% in the no-stoma group and 21.6% in the stoma group ( P =0.4). The rate of unplanned admissions was 7% in the no-stoma group and 27% in the stoma group ( P =0.01).

CONCLUSION

A defunctioning stoma does not appear to reduce the rate of AL in high-risk patients, but its impact on the management of AL remains unclear.

Training prediction models for individual risk assessment of postoperative complications after surgery for colorectal cancer

BACKGROUND

The occurrence of postoperative complications and anastomotic leakage are major drivers of mortality in the immediate phase after colorectal cancer surgery. We trained prediction models for calculating patients' individual risk of complications based only on preoperatively available data in a multidisciplinary team setting. Knowing prior to surgery the probability of developing a complication could aid in improving informed decision-making by surgeon and patient and individualize surgical treatment trajectories.

METHODS

All patients over 18 years of age undergoing any resection for colorectal cancer between January 1, 2014 and December 31, 2019 from the nationwide Danish Colorectal Cancer Group database were included. Data from the database were converted into Observational Medical Outcomes Partnership Common Data Model maintained by the Observation Health Data Science and Informatics initiative. Multiple machine learning models were trained to predict postoperative complications of Clavien-Dindo grade ≥ 3B and anastomotic leakage within 30 days after surgery.

RESULTS

Between 2014 and 2019, 23,907 patients underwent resection for colorectal cancer in Denmark. A Clavien-Dindo complication grade ≥ 3B occurred in 2,958 patients (12.4%). Of 17,190 patients that received an anastomosis, 929 experienced anastomotic leakage (5.4%). Among the compared machine learning models, Lasso Logistic Regression performed best. The predictive model for complications had an area under the receiver operating characteristic curve (AUROC) of 0.704 (95%CI 0.683-0.724) and an AUROC of 0.690 (95%CI 0.655-0.724) for anastomotic leakage.

CONCLUSIONS

The prediction of postoperative complications based only on preoperative variables using a national quality assurance colorectal cancer database shows promise for calculating patient's individual risk. Future work will focus on assessing the value of adding laboratory parameters and drug exposure as candidate predictors. Furthermore, we plan to assess the external validity of our proposed model.

LekCheck: A Prospective Study to Identify Perioperative Modifiable Risk Factors for Anastomotic Leakage in Colorectal Surgery

OBJECTIVE

To assess potentially modifiable perioperative risk factors for anastomotic leakage in adult patients undergoing colorectal surgery.

SUMMARY BACKGROUND DATA

Colorectal anastomotic leakage (CAL) is the single most important denominator of postoperative outcome after colorectal surgery. To lower the risk of CAL, the current research focused on the association of potentially modifiable risk factors, both surgical and anesthesiological.

METHODS

A consecutive series of adult patients undergoing colorectal surgery with primary anastomosis was enrolled from January 2016 to December 2018. Fourteen hospitals in Europe and Australia prospectively collected perioperative data by carrying out the LekCheck, a short checklist carried out in the operating theater as a time-out procedure just prior to the creation of the anastomosis to check perioperative values on 1) general condition 2) local perfusion and oxygenation, 3) contamination, and 4) surgery related factors. Univariate and multivariate logistic regression analysis were performed to identify perioperative potentially modifiable risk factors for CAL.

RESULTS

There were 1562 patients included in this study. CAL was reported in 132 (8.5%) patients. Low preoperative hemoglobin (OR 5.40, P < 0.001), contamination of the operative field (OR 2.98, P < 0.001), hyperglycemia (OR 2.80, P = 0.003), duration of surgery of more than 3 hours (OR 1.86, P = 0.010), administration of vasopressors (OR 1.80, P = 0.010), inadequate timing of preoperative antibiotic prophylaxis (OR 1.62, P = 0.047), and application of epidural analgesia (OR, 1.81, P = 0. 014) were all associated with CAL.

CONCLUSIONS

This study identified 7 perioperative potentially modifiable risk factors for CAL. The results enable the development of a multimodal and multidisciplinary strategy to create an optimal perioperative condition to finally lower CAL rates.

Updates of Risk Factors for Anastomotic Leakage after Colorectal Surgery

Anastomotic leakage is a potentially severe complication occurring after colorectal surgery and can lead to increased morbidity and mortality, permanent stoma formation, and cancer recurrence. Multiple risk factors for anastomotic leak have been identified, and these can allow for better prevention and an earlier diagnosis of this significant complication. There are nonmodifiable factors such as male gender, comorbidities and distance of tumor from anal verge, and modifiable risk factors, including smoking and alcohol consumption, obesity, preoperative radiotherapy and preoperative use of steroids or non-steroidal anti-inflammatory drugs. Perioperative blood transfusion was shown to be an important risk factor for anastomotic failure. Recent studies on the laparoscopic approach in colorectal surgery found no statistical difference in anastomotic leakage rate compared with open surgery. A diverting stoma at the time of primary surgery does not appear to reduce the leak rate but may reduce its clinical consequences and the need for additional surgery if anastomotic leakage does occur. It is still debatable if preoperative bowel preparation should be used, especially for left colon and rectal resections, but studies have shown similar incidence of postoperative leak rate.

The impact of synchronous liver resection on the risk of anastomotic leakage following elective colorectal resection. A propensity score match analysis on behalf of the iCral study group

INTRODUCTION

how best to manage patients with colorectal cancer and synchronous liver metastasis is still controversial, with specific concerns of increased risk of postoperative complications following combined resection. We aimed at analyzing the influence of combined liver resection on the risk of anastomotic leak (AL) following colorectal resection.

METHODS

we reviewed the iCral prospectively maintained database to compare the relative risk of AL of patients undergoing colorectal resection for cancer to that of patients receiving simultaneous liver and colorectal resection for cancer with isolated hepatic metastases. The incidence of AL was the primary outcome of the analysis. Perioperative details and postoperative complications were also appraised.

RESULTS

out of a total of 996 patients who underwent colorectal resection for cancer, 206 receiving isolated colorectal resection were compared with a matched group of 53 patients undergoing simultaneous liver and colorectal resection. Combined surgery had greater operative time and resulted in longer postoperative hospitalization compared to colorectal resection alone. The proportion of overall morbidity following combined resection was significantly higher than after isolated colorectal resection (56.6% vs. 37.9%, p = 0.021). Overall, the two groups of patients did not differ neither on the rate of major postoperative complications, nor in terms of AL (9.4% vs. 6.3%, p = 0.381). At specific multivariate analysis, the duration of surgery was the only risk factor independently associated with the likelihood of AL.

CONCLUSIONS

combining hepatic with colorectal resection for the treatment of synchronous liver metastasis from colorectal cancer does not increase significantly the incidence of AL.

Real-time fluorescence image-guided gastrointestinal oncologic surgery: Towards a new era

Technological improvements are crucial in the evolution of surgery. Real-time fluorescence-guided surgery (FGS) has spread worldwide, mainly because of its usefulness during the intraoperative decision-making processes. The success of any gastrointestinal oncologic resection is based on the anatomical identification of the primary tumor and its regional lymph nodes. FGS allows also to evaluate the blood perfusion at the gastrointestinal stumps after colorectal or esophageal resections. Therefore, a reduction on the anastomotic leak rates has been postulated as one of the foreseeable benefits provided by the use of FGS in these procedures. Although the use of fluorescence in lymph node detection was initially described in breast cancer surgery, the technique is currently applied in gastric or splenic flexure cancers, as they both present complex and variable lymphatic drainages. FGS allows also to perform intraoperative lymphograms or sentinel lymph node biopsies. New applications of FGS are being developed to assist in the detection of peritoneal metastases or in the evaluation of the tumor resection margins. The present review aims to provide a general overview of the current status of real-time FGS in gastrointestinal oncologic surgery. We put a special focus on the different applications of FGS, discussing the main findings and limitations found in the contemporary literature and also the promising near future applications.

Indocyanine Green Fluorescence in Colorectal Cancer

Fluorescence vision using indocyanine green is a surgical tool with increasing applications in colorectal cancer surgery. This tool has received acceptance in several disciplines as a potential method to improve visualization of the surgical field, improve lymph node resection and decrease the incidence of anastomotic leaks (ALs). In colorectal surgery specifically, some studies have shown that intraoperative fluorescence imaging is a safe and feasible method to evaluate anastomotic perfusion, and its use could affect the incidence of anastomotic leaks. Currently, controlled trials are carried out to validate these conclusions, as well as new indications for indocyanine green such as detection and guidance in the management of hepatic colorectal metastases, visualization of ureters and even as tumor marking and improvement the lymph node harvest of early tumors. These advances could offer great value to surgeons and patients, by improving the accuracy and results of cancer resections.

Predictive and Diagnostic Biomarkers of Anastomotic Leakage: A Precision Medicine Approach for Colorectal Cancer Patients

Development of an anastomotic leak (AL) following intestinal surgery for the treatment of colorectal cancers is a life-threatening complication. Failure of the anastomosis to heal correctly can lead to contamination of the abdomen with intestinal contents and the development of peritonitis. The additional care that these patients require is associated with longer hospitalisation stays and increased economic costs. Patients also have higher morbidity and mortality rates and poorer oncological prognosis. Unfortunately, current practices for AL diagnosis are non-specific, which may delay diagnosis and have a negative impact on patient outcome. To overcome these issues, research is continuing to identify AL diagnostic or predictive biomarkers. In this review, we highlight promising candidate biomarkers including ischaemic metabolites, inflammatory markers and bacteria. Although research has focused on the use of blood or peritoneal fluid samples, we describe the use of implantable medical devices that have been designed to measure biomarkers in peri-anastomotic tissue. Biomarkers that can be used in conjunction with clinical status, routine haematological and biochemical analysis and imaging have the potential to help to deliver a precision medicine package that could significantly enhance a patient's post-operative care and improve outcomes. Although no AL biomarker has yet been validated in large-scale clinical trials, there is confidence that personalised medicine, through biomarker analysis, could be realised for colorectal cancer intestinal resection and anastomosis patients in the years to come.

Management of postoperative complications after laparoscopic left hemicolectomy - an approach in modern times after incorporation of indocyanine green (ICG) and full mobilization of the splenic flexure

BACKGROUND

Aim is to report our experience in the management of complications after laparoscopic left hemicolectomy (LLH) after the incorporation in our clinical practice of intraoperative indocyanine green (ICG) fluorescence angiography (FA).

METHODS

In our last period after incorporation of ICG-FA, 277 unselected consecutive patients underwent laparoscopic colorectal surgery with this technology. Ninety-seven (35%) right hemicolectomy, 19 segmental resection of the splenic flexure (6.9%), 54 anterior resection of the rectum (19.5%) and 107 LLH (38.6%) were performed. Complications were graded according to Clavien-Dindo classification, and anastomotic leakages (AL) were graded according to Clavien-Dindo classification and to International Study Group of Rectal Cancer (ISGRC) classification.

RESULTS

Eight surgical and one medical complications (8.4%) were observed. Two AL occurred (1.9%). One drained spontaneously by drainage placed intraoperatively (Clavien-Dindo I, ISGRC A) and one treated by laparoscopic peritoneal lavage, leakage suture and ileostomy (Clavien-Dindo III-b, ISGRC C). Other complications were: wound infection (Clavien-Dindo II)(2); postoperative anemia caused by rectorrhagia (Clavien-Dindo II)(2); pelvic abscess between bladder and uterus (Clavien-Dindo III-a)(1); hemoperitoneum secondary to inferior mesenteric artery bleeding treated with peritoneal lavage and hemostasis (Clavien-Dindo III-b)(1); atrial fibrillation (Clavien- Dindo II)(1). All complications have been resolved.

CONCLUSIONS

The complication rate after LLH after the incorporation of ICG-FA is low, since the number of AL have dramatically decreased in comparison to our previous experience. The management of these patients proved to be safe and effective due to in all cases the complication has been resolved. Further studies are required to standardize the management of these patients.

Reinforcement of rectal anastomoses with a collagen-based haemostatic patch: a case series report

In this case series report of 10 colorectal cancer patients, a polyethylene glycol-coated collagen-based haemostatic patch was applied after rectal resection to reinforce rectal anastomoses and reduce anastomotic leakage. Patients underwent rectal resection and anastomoses were stapled in place. The patch—Hemopatch®—was applied to 75% of the anastomotic circumference. The surgeon judged the simplicity of application using a reinforcement of rectal anastomosis score. Mean age of patients was 68.1 (range 50–94) years. The patch was successfully applied in eight patients; in seven patients, patch application was straightforward or only slightly complex, according to the reinforcement of rectal anastomosis score. Seven of eight patients experienced no leakage or signs of stricture 6 weeks post-surgery. All patients underwent radical resection. It is possible to apply Hemopatch® during colorectal surgery. However, the patch application procedure needs to be standardized and efficacy needs to be evaluated by conducting larger clinical studies.

The usefulness of transanal tube for reducing anastomotic leak in mid rectal cancer: compared to diverting stoma

Purpose

Diverting stoma (DS) and transanal tube (TAT) are the 2 main procedures for reducing anastomotic leak (AL) in rectal cancer surgery. However, few studies have compared the protective effect of the 2 modalities against AL.

Methods

Total of 165 patients with mid rectal cancer, who underwent curative resection from 2012 to 2017, were included. Clinical characteristics and outcomes were compared. Risk factors for AL were identified using multivariate analysis.

Results

The DS group had lower tumor location, higher rates of neoadjuvant concurrent chemoradiotherapy, and longer operative time than the TAT group. However, the level of the anastomosis did not show statistically significant differences (DS: 4.6 cm vs. TAT: 4.9 cm, P = 0.061). AL occurred in 14 of the 165 patients (8.5%), with 10 (10.2%) in the DS group and 4 (6.0%) in the TAT group (P = 0.405). On multivariate analysis, only low body mass index (BMI) and smoking were significantly related to AL. Neither the protection method nor neoadjuvant chemoradiotherapy demonstrated statistical differences in AL. Seven of 10 patients in the DS group who experienced AL were treated conservatively, while all 4 in the TAT group underwent reoperation.

Conclusion

TAT seems to have comparable protective effect against AL to DS. However, in AL, DS appeared to be more effective in preventing reoperation. Therefore, DS is recommended in patients with low BMI or smoking, and with an expected higher probability of morbidity or mortality in case of reoperation. In other cases, TAT may be considered as an alternative to DS.

The assessment of perioperative risk factors of anastomotic leakage after intestinal surgeries; a prospective study

Background

Anastomotic leaks (AL) are among the most serious complications due to the substantial impact on the quality of life and mortality. Inspite of the advance in diagnostic tools such as laboratory tests and radiological adjuncts, only moderate improvement has been recorded in the rate of detected leaks. The purpose of the research was to assess the perioperative risk factors for AL.

Methods

This study was achieved at MUH and MIH/Egypt within the period between January 2016 and January 2019 for the candidates who underwent bowel anastomosis for small intestinal (except duodenal one) and colorectal pathology. The collected data were analyzed using SPSS of V-26.

Results

This study included 315 cases, among them, 27 cases (8.57%) developed AL. The percentage of covering stoma was significantly higher in the non-leakage group vs leakage one (24.3% vs 11.1% respectively). lower albumin, operative timing, perforation, and covering stoma were shown as significant risk factors for leakage, but with multivariate analysis for these factors, the emergency operation, and serum albumin level was the only independent risk factors that revealed the significance consequently (p = 0.043, p = 0.015). The analysis of different predictors of AL on the third day showed that the cut-off point in RR was 29 with 83% sensitivity and 92% specificity in prediction of leakage, the cut-off point in RR was 118 with 74% sensitivity and 87% specificity in prediction of leakage and the cut-off point in CRP was 184.7 with 82% sensitivity and 88% specificity in prediction of AL and all had statistically significant value.

Conclusions

The preoperative serum albumin level and the emergency operations are independent risk factors for anastomotic leakage. Moreover, leakage should be highly suspected in cases with rising respiratory rate, heart rate, and CRP levels.

Review of Colonic Anastomotic Leakage and Prevention Methods

Although surgeries involving anastomosis are relatively common, anastomotic leakages are potentially deadly complications of colorectal surgeries due to increased risk of morbidity and mortality. As a result of the potentially fatal effects of anastomotic leakages, a myriad of techniques and treatments have been developed to treat these unfortunate cases. In order to better understand the steps taken to treat this complication, we have created a composite review involving some of the current and best treatments for colonic anastomotic leakage that are available. The aim of this article is to present a background review of colonic anastomotic leakage, as well as current strategies to prevent and treat this condition, for a broader audience, including scientist, engineers, and especially biomedical engineers.

Analysis of risk factors for anastomotic leakage after lower rectal Cancer resection, including drain type: a retrospective single-center study

Background

We investigated the correlations between surgery-related factors and the incidence of anastomotic leakage after low anterior resection (LAR) for lower rectal cancer.

Methods

A total of 630 patients underwent colorectal surgery between 2011 and 2014 in our department. Of these, 97 patients (15%) underwent LAR and were enrolled in this retrospective study. Temporary ileostomy was performed in each patient.

Results

Anastomotic leakage occurred in 21 patients (21.7%). Univariate analysis showed a significant association between operative duration (p = 0.005), transanal hand-sewn anastomosis (p = 0.014), and operation procedure (p = 0.019) and the occurrence of leakage. Multivariate regression reanalysis showed that underlying disease (p = 0.044), transanal hand-sewn anastomosis (p = 0.019) and drain type (p = 0.025) were significantly associated with the occurrence of leakage. The propensity-score analysis showed that closed drainage were 6.3 times more likely to have anastomotic leakage than open drainage in relation to the amount of postoperative drainage (ml), according to the inverse probability of treatment-weighted analysis.

Conclusions

Our results indicate that underlying disease, transanal hand-sewn anastomosis, and closed drain may be a risk and predictive factors for anastomotic leakage after LAR for lower rectal cancer. The notable finding was that closed drainage was related to the occurrence of anastomotic leakage and closed drainage was correlated with less volume of postoperative drain discharge than open drain.

Colorectal anastomosis dehiscence: a call for more detailed morphological classification

Introduction

A proactive approach is recommended in colorectal anastomosis leak treatment, and early diagnosis is very important. Early postoperative endoscopy would allow rapid diagnosis of anastomotic pathologies and consequent prompt intervention according to anastomotic disruption morphology.

Aim

To evaluate the effectiveness of close endoscopic follow-up of all patients (including asymptomatic ones) in improving diagnosis of acute leak (AL) and reducing its complications.

Material and methods

This study included 124 patients who had undergone rectum resection for rectal cancer with stapled anastomosis. Endoscopy was performed between the 7^th and 10^th postoperative day and 1 month postoperatively. For defect morphology assessment, a classification system was created based on four levels of severity. Photographic findings were evaluated by an independent, experienced gastroenterologist.

Results

Postoperative endoscopy revealed 28 (22.6%) patients with acute leakage. Initial endoscopy confirmed AL in 18 patients. Six (31.6%) patients were asymptomatic and 13 (68.4%) were symptomatic. The second endoscopy revealed another 9 (32.1%) leaks (4 (44.5%) asymptomatic and 5 (55.5%) symptomatic). Sixteen (57.1%) patients had grade A leakages, 7 (25.0%) had grade B leakages, and 5 (17.9%) had grade C leakages. Furthermore, 22 of 27 (81%) defects were located posterior and posterior-laterally. Fifteen (55.5%) defects were smaller than 1/3 the circumference, 7 (25.9%) affected 1/3–1/2 of the circumference, and 5 (18.5%) affected more than 1/2 of the circumference.

Conclusions

Incorporation of early endoscopy in postoperative management allows rapid diagnosis of AL and allows faster intervention, even in leaks that are clinically silent.

Italian multi-society modified Delphi consensus on the definition and management of anastomotic leakage in colorectal surgery

INTRODUCTION

The incidence of anastomotic leak (AL) has not decreased over the past decades and some important grey areas remain in its definition, prevention, and management. The aim of this study was to reach a national consensus on the definition of AL and to identify key points to be applied in clinical practice.

METHODS

A 3-step modified Delphi method was used to establish consensus. Ten representative members of the major Italian surgical scientific societies with proven colorectal expertise were selected after a call to action. After a comprehensive literature search, each expert drew a list of evidence-based statements which were voted in round one by the scientific board. Panel members were asked to mark "totally disagree", "partially agree" or "totally agree" for each statement and provide comments. The same voting method was used for round 2. Round 3 consisted of a final face-to-face meeting.

RESULTS

Thirty-three statements (clustered into 14 topics) were included in round 1. Following the third voting round, a final list of 16 items was formulated, which encompass the following 9 topics: AL definition, patient- and operative-related risk factors, prevention measures, bowel preparation, surgical technique, intraoperative assessment, early diagnosis, radiological diagnosis and management of specific patterns of AL. The overall response rate was 100% for all items in all the three rounds.

CONCLUSIONS

This Delphi survey identified items that expert colorectal surgeons agreed were important to be applied in the prevention, diagnosis, and management of AL. This represents the first consensus involving all relevant national scientific societies, defining important and shared concepts in the diagnosis and management of AL.

Risk prediction models for postoperative outcomes of colorectal cancer surgery in the older population - a systematic review

BACKGROUND

An increasing number of patients with Colorectal Cancer (CRC) is 65 years or older. We aimed to systematically review existing clinical prediction models for postoperative outcomes of CRC surgery, study their performance in older patients and assess their potential for preoperative decision making.

METHODS

A systematic search in Pubmed and Embase for original studies of clinical prediction models for outcomes of CRC surgery. Bias and relevance for preoperative decision making with older patients were assessed using the CHARMS guidelines.

RESULTS

26 prediction models from 25 publications were included. The average age of included patients ranged from 61 to 76. Two models were exclusively developed for 65 and older. Common outcomes were mortality (n = 10), anastomotic leakage (n = 7) and surgical site infections (n = 3). No prediction models for quality of life or physical functioning were identified. Age, gender and ASA score were common predictors; 12 studies included intraoperative predictors. For the majority of the models, bias for model development and performance was considered moderate to high.

CONCLUSIONS

Prediction models are available that address mortality and surgical complications after CRC surgery. Most models suffer from methodological limitations, and their performance for older patients is uncertain. Models that contain intraoperative predictors are of limited use for preoperative decision making. Future research should address the predictive value of geriatric characteristics to improve the performance of prediction models for older patients.

Early Metabolic and Inflammatory Intraperitoneal Changes After Rectum Perforation

Purpose

Anastomotic leakage (AL) is the most dreaded complication in rectal surgery. It has a great impact on postoperative morbidity and mortality. This animal model, in which we have studied postoperative metabolic and inflammatory changes, is designed to imitate an AL.

Methods

Twelve pigs were randomized into 2 groups. In the experimental group, an iatrogenic rectal perforation was performed, with the control group having a sham operation. The 2 groups were followed for 10 hours after operation with regard to vital parameters, arterial lactate, and cytokines interleukin (IL) 1, IL6, and IL10 in the blood and intraperitoneally. Intraperitoneal microdialysis analyses of glucose, lactate, glycerol, and pyruvate were performed and the lactate/pyruvate ratio was calculated.

Results

Glucose levels were lower in the experimental group after 4 hours. After 7 hours, lactate and lactate/pyruvate ratio was higher in the experimental group. At the same time intraperitoneal cytokines IL6 and IL10 were higher in the experimental group. Blood samples showed higher IL6 after 7 hours in the experimental group.

Conclusion

In this study, several significant differences between the groups in metabolic and inflammatory values were detected. Further clinical studies are recommended to evaluate the importance of intraperitoneal metabolic and inflammatory analyses as a diagnostic tool for early identification of an AL.

Development of a Risk Score to Predict Anastomotic Leak After Left-Sided Colectomy: Which Patients Warrant Diversion?

BACKGROUND

Anastomotic leak is a feared complication after left-sided colectomy, but its risk can potentially be reduced with the use of a diverting ostomy. However, an ostomy has its own associated negative sequelae; therefore, it is critical to appropriately identify patients to divert. This is difficult in practice since many risk factors for anastomotic leak exist and outside factors bias this decision. We aimed to develop and validate a risk score to predict an individual's risk of anastomotic leak and aid in the decision.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program Colectomy Targeted PUF was queried from 2012 to 2016 for patients undergoing elective left-sided resection for malignancy, benign neoplasm, or diverticular disease. Multivariable logistic regression identified predictors of anastomotic leak in non-diverted patients, and a risk score was developed and validated.

RESULTS

38,475 patients underwent resection with an overall anastomotic leak rate of 3%. Independent risk factors for anastomotic leak included younger age, male sex, tobacco use, and omission of combined bowel preparation. A risk score incorporating independent predictors demonstrated excellent calibration. There was strong visual correspondence between predicted and observed anastomotic leak rates. 3960 patients underwent resection with diversion, yet over half of these patients had a predicted leak rate of less than 4%.

CONCLUSION

A novel risk score can be used to stratify patients according to anastomotic leak risk after elective left-sided resection. Intraoperative calculation of scores for patients can help guide surgical decision-making in both diverting the highest risk patients and avoiding diversion in low-risk patients.

A Decalogue to Avoid Routine Ileostomy in Selected Patients With Border Line Risk to Develop Anastomotic Leakage After Minimally Invasive Low-Anterior Resection: A Pilot Study

Purpose. Protective ileostomy (PI) during anterior resection (AR) for rectal cancer decreases the incidence of anastomotic leakage (AL) and its subsequent complications, but it may itself be the cause of morbidity. The aim is to report our protocol in the management of selected patients with borderline risk to develop AL after laparoscopic AR and ghost ileostomy (GI) creation. Methods. Patients who underwent AR were stratified based on the risk to develop AL. Steps to avoid PI were splenic flexure mobilization, reduced pelvic bleeding, to employ different stapler charge if neoadjuvant chemo-radiotherapy is performed, to perform a horizontal section of the rectum, to evaluate the anastomotic vascularization with a fluorescence angiography, to perform a side-to-end anastomosis, intraoperative methylene blue test, pelvic and transanal drainage tubes placement, and the GI creation. After surgery, inflammatory blood markers were monitored to detect potential leakages. Results. Twelve patients were included. In one case, the specimen proximal section was changed after fluorescence angiography. There were no conversions in this group of patients. One postoperative AL occurred and was treated with radiological drainage placement, not being necessary to convert the GI. PI was avoided in 100% of cases. Conclusions. Patients' characteristics cannot be changed, but several steps were used to avoid routine PI creation. The present protocol could be a valuable option to avoid PI in selected patients. Further studies with a wider sample size, and defined criteria to stratify the patients based on the risk to develop AL, are required.

Modified Colon Leakage Score to Predict Anastomotic Leakage in Patients Who Underwent Left-Sided Colorectal Surgery

Colon leakage score (CLS) was introduced as a clinical tool to predict anastomotic leakage (AL) in patients who underwent left-sided colorectal surgery, but its clinical validity has not been widely studied. We evaluated the clinical utility of CLS and developed a modified CLS (m-CLS). In total, 566 patients who underwent left-sided colorectal surgery were enrolled and categorized into training (n = 396) and validation (n = 170) sets via random sampling. Using CLS variables, the least absolute shrinkage and selection operator (LASSO) regression model was applied for variable selection and predictive signature building in the training set. The model's performance was validated in the validation set. The predictive powers of m-CLS and CLS were compared by the area under the receiver operating characteristic (AUROC) curve in the overall group. Twenty-three AL events (4.1%) were noted. The AL group had a significantly higher mean CLS than the No Leakage group (12.5 vs. 9.6, p = 0.001). Five clinical variables were selected and used to generate m-CLS. The predictive performance of m-CLS was similar in training and validation sets (AUROC 0.838 vs. 0.803, p = 0.724). In the overall set, m-CLS was significantly predictive of AL and performed better than CLS (AUROC 0.831 vs. 0.701, p = 0.008). In conclusion, LASSO-model-generated m-CLS could predict AL more accurately than CLS.

External validation of anastomotic leakage risk analysis system in patients who underwent colorectal resection

Background/aim

One of the most feared complications after colon resection for carcinoma is anastomotic leakage. Prediction of anastomotic leakage can alter pre- and perioperative management of patients. This study validates an anastomotic leakage prediction system.

Materials and methods

Ninety-five patients who underwent colonic resection between 1 January 2016 and 30 January 2017 were included in the study. Patient records and electronic charting system data were used to calculate anastomotic leakage risk on the http://www.anastomoticleak.com/ website.

Results

Fifty-six (58.9%) patients were male and thirty-nine (41.1%) were female. The mean age was 61.7 (min: 33, max: 90). Six (6.3%) patients had anastomotic leakage. According to the ROC analysis, the area under curve for the prediction system was 0.767.

Conclusion

The prediction system for anastomotic leakage produced significant results for our patient population. It can be effectively utilized in preoperative and perioperative measures to prevent anastomotic leakage.

Laparoscopic surgery may decrease the risk of clinical anastomotic leakage and a nomogram to predict anastomotic leakage after anterior resection for rectal cancer

INTRODUCTION

Anastomotic leakage is still one of the most dreaded complications after anterior resection for rectal cancer. This study aimed to identify risk factors for anastomotic leakage and to create a nomogram for precise prediction of anastomotic leakage after anterior resection for rectal cancer.

METHODS

Two thousand six hundred eighteen consecutive patients who underwent anterior resection for rectal cancer with primary anastomosis, with or without diverting stoma, were retrospectively analyzed as a training dataset. Univariate and multivariable Cox regression analyses were used to determine independent risk factors associated with anastomotic leakage. A nomogram was constructed to predict anastomotic leakage. Data containing 611 patients were prospectively collected as a test dataset. The performance of the nomogram was evaluated by using a bootstrapped-concordance index and calibration plots.

RESULTS

The rate of clinical anastomotic leakage was 9.3% in the training dataset. Multivariate analysis identifies the following variables as independent risk factors for anastomotic leakage: gender (male) (odds ratio (OR) = 2.286), distance of tumor to anal verge (OR = 0.791), tumor size (OR = 1.175), operating time (OR = 1.009), diabetes mellitus (OR = 1.704), laparoscopic surgery (OR = 0.445), anastomotic bleeding (OR = 13.46), and diverting stoma (OR = 0.386). We created a nomogram with high discriminative ability (concordance index, 0.722). The area under the curve value, which evaluated the predictive performance of external validation, was 0.723.

CONCLUSIONS

A protective diverting stoma and laparoscopic surgery significantly decrease the risk of anastomotic leakage. Our nomogram was a useful tool for precise prediction of anastomotic leakage after anterior resection for rectal cancer.

Progress in prevention and treatment of anastomotic leakage after surgery for rectal cancer

Colorectal cancer (CRC) is one of the most common malignant tumors in the world, and its morbidity and mortality both rank third among all malignant tumors in China. Rectal cancer accounts for 60%-70% of cases of CRC. With the in-depth study of the pathogenesis of CRC and the mechanism of tumor metastasis, and the improvement of surgical techniques and methods, anal sphincter surgery for middle and low rectal cancer is increasing gradually. Although the quality of life of the patients improves significantly after anal sphincter preservation for rectal cancer, anastomotic leakage is still one of the most common and serious complications. Studies show that the incidence of anastomotic leakage after surgery for low rectal cancer is 3%-21%, and the death rate is up to 3%. Therefore, a comprehensive assessment of patients and analysis of risk factors before operation is of great significant for reducing the potential risk of anastomotic leakage and choosing surgical approach and appropriate preventive measures to prevent and reduce the occurrence of anastomotic leakage. In this paper, we summarize the recent research on anastomotic leakage after rectal cancer surgery in order to help other clinicians reduce the incidence of anastomotic leakage in clinical practice.

Intraoperative air leak test reduces the rate of postoperative anastomotic leak: analysis of 777 laparoscopic left-sided colon resections

BACKGROUND

The evidence supporting the use of the air leak test (ALT) after laparoscopic left-sided colon resection (LLCR) to test the colorectal anastomosis (CA) integrity aiming at reducing the rate of postoperative CA leakage (CAL) is not conclusive. The aim of this study was to challenge the use of ALT after elective LLCR.

METHODS

It is a retrospective analysis of a prospectively collected database including all patients undergoing elective LLCR with primary CA and no proximal bowel diversion between January 1996 and June 2017. The decision to perform the ALT was based on the individual surgeon routine practice. A multivariate analysis was performed to identify independent risk factors for CAL.

RESULTS

A total of 777 LLCR without proximal diversion were included in the analysis: the CA was tested in 398 patients (ALT group), while intraoperative ALT was not performed in 379 patients (No-ALT group). The two groups were similar in demographic characteristics, indication, and type of procedure. Intraoperative ALT was positive in 20 (5%) patients: a stoma was created in 14 (70%) patients, while 6 (30%) patients had a suture repair alone. Overall, postoperative CAL occurred in 32 patients (4.1%): the postoperative CAL rate was lower in ALT patients (2.5% vs. 5.8%, p = 0.025). A reoperation was needed in 87.5% of cases. No CAL occurred in the 20 patients with intraoperative positive ALT. Multivariate analysis showed that ASA score 3-4 (OR 5.39, 95% CI 2.53-11.51, p < 0.001) and male sex (OR 3.96, 95% CI 1.66-9.43, p = 0.002) were independent risk factors for postoperative CAL, while intraoperative ALT independently reduced the postoperative CAL rate (OR 0.40, 95% CI 0.18-0.88, p = 0.022).

CONCLUSION

Intraoperative ALT allows to detect AL defects after LLCR that can be effectively managed intraoperatively, leading to a significant lower risk of postoperative CAL.

Ghost Ileostomy in Advanced Ovarian Cancer: A Reliable Option

Objective

Diverting ileostomy (DI) has been proposed to reduce the incidence and consequences anastomotic leakage after bowel resection. In colorectal cancer treatment, ghost ileostomy (GI) has been proposed as an alternative to DI. Our objective was to report the results of GI associated with colorectal resection in the treatment of ovarian cancer.

Materials and Methods

This is an observational pilot study performed in a single institution. The main objective sought was to report the results of GI associated with colorectal resection in the treatment of ovarian cancer: 26 patients were included.

Results

Modified posterior exenteration was performed in 24 cases (92.3%) and rectum resection in the 2 cases of relapse (7.7%). After the main procedure GI was created, to check up the anastomosis status, a sequential postoperative rectoscopy was performed on postoperative day 5 ± 1 (range, 4–7). Serum levels were monitored in first and third postoperative days just with a descriptive intention to establish its relationship with the rectoscopy findings. In 2 cases, rectoscopy demonstrated a leakage. During postoperative course, no other complication related with the GI or DI was observed. No case of clinical anastomotic leakage was found.

Conclusions

To the extent of our knowledge, this is the first study in which GI has been performed for the treatment of patients with ovarian cancer. Ghost ileostomy represents a real option that may reduce the number of ileostomies performed in ovarian cancer without increasing the morbimortality. Ghost ileostomy presents the advantages of DI while avoiding its drawbacks. It also seems to be a safe, feasible, and reproducible technique that does not add significant costs to the surgery.

The effect of gender on early colonic anastomotic wound healing

PURPOSE

Clinically, male patients subjected to colorectal surgery are more prone to develop anastomotic leakage than female patients by unknown mechanisms. Our aim was to investigate the impact of gender on anastomotic wound healing using an experimental model.

METHODS

One-layer colonic anastomosis was constructed in 8-week-old 28 male and 32 female Sprague-Dawley rats. Animals of one group (n = 30) were sacrificed immediately after surgery day 0 and the other group (n = 30) on postoperative day 3. Anastomotic breaking strength, total collagen (hydroxyproline), soluble collagen (Sircol), matrix metalloproteinase (MMP)-9, and transforming growth factor (TGF)-β1 were measured.

RESULTS

The anastomotic breaking strength decreased from day 0 to day 3 with no significant gender differences either in the extent of decline (P = 0.122) or absolute day 3 strengths (P = 0.425). Analogously, total collagen concentration in the anastomotic wounds decreased postoperatively and were lower (P = 0.043) in the male compared with the female rats on day 3. MMP-9 levels increased in the anastomoses postoperatively, but they did not differ (P = 0.391) between male and female animals. Soluble collagen levels were lower in the day-3 anastomoses of male versus female rats (P = 0.015) and correlated positively with total TGF-β1 levels (r_S = 0.540, P = 0.006). Although TGF-β1 tended to be lower in male compared with the female rats, the differences did not reach statistical significance.

CONCLUSION

Our findings point towards a less favorable collagen metabolism in colonic anastomoses of male compared with female rats during early wound healing.

Neopterin, kynurenine and tryptophan as new biomarkers for early detection of rectal anastomotic leakage

Introduction

At present, there are no strong predictors, nor a useful scoring system, that clearly identifies patients at risk for anastomotic leakage.

Aim

This study aimed to investigate a new method that assesses this risk by monitoring levels of neopterin, tryptophan, and kynurenine, in bodily fluids.

Material and methods

This prospective study included patients who underwent elective rectal resection for carcinoma. The basic condition for inclusion was rectal anastomosis using the double-stapling technique. Preoperative levels of neopterin, tryptophan, kynurenine, and their ratios, were assessed with blood and urine samples. These levels were then monitored for 6 postoperative days in venous blood, urine, and abdominal drainage fluid.

Results

A total of 42 patients were enrolled in the study. Thirty-six patients underwent a laparoscopic resection and 6 patients had an open procedure. No differences were found among neopterin, tryptophan, and kynurenine serum levels. However, the groups were observed to have significant differences in the urinary neopterin/creatinine ratio: the preoperative neopterin/creatinine ratio was 139.5 μmol/mol in the group with leakage, vs 114.8 μmol/mol in the group without complications, p = 0.037. The same results were observed during the postoperative period, p = 0.012. Additionally, the group with complications had a higher mean value of neopterin in drainage fluid, p = 0.048.

Conclusions

Our study demonstrated that high preoperative levels of urinary neopterin could be interpreted as a risk for anastomotic leakage. Moreover, pathological levels of neopterin in urine and abdominal drainage fluid could be useful for early identification of anastomotic leakage during the postoperative period prior to its clinical development.

Calcification of the iliac arteries: a marker for leakage risk in rectal anastomosis-a blinded clinical trial

PURPOSE

Anastomotic leakage (AL) is associated with increased morbidity and mortality after colorectal surgery. Calcification of the arteries has been identified as a risk factor for cardiovascular events and can be reliably measured on computed tomography using software assistance. The aim of this prospective study was to prove the value of calcium scoring of the iliac arteries as a predictor of AL after rectal anastomosis.

METHODS

Consecutive patients who underwent colorectal resection with rectal anastomosis were analyzed. Diagnostic computed tomography images were used to detect calcification of the arteries supplying the rectal anastomosis. Logistic regression analysis was used to determine the relationship between vascular calcification and AL.

RESULTS

Of 139 included and analyzed patients, AL occurred in 15 (11%). The volume and calcium scores were significantly higher in the infrarenal aorta, the left and right common iliac artery, and the left internal iliac artery. In univariate analysis, calcification of the left internal iliac artery and both internal iliac arteries combined correlated with the occurrence of the primary endpoint. A receiver operating curve analysis led to the cut-off values of 30 and 6 for the volume score and calcium score, respectively. They provide a negative predictive value of 0.97 and a positive predictive value of 0.19.

CONCLUSIONS

Calcification in the iliac arteries appears to be a good marker for the risk of leakage after rectal anastomosis. The calcification scoring system is easy to calculate after computed tomography and may aid in patient selection to create a protective ileostomy.