Definition of colorectal anastomotic leakage: A consensus survey among Dutch and Chinese colorectal surgeons

Double-row staple technology versus triple-row staple technology for colorectal surgery: A systematic review and meta-analysis

BACKGROUND

Some observational data have suggested that anastomotic leak may be reduced with triple-row staple technology compared to double-row staple technology. We aimed to investigate this further by performing a systematic review comparing double- and triple-row staple technology for colorectal anastomoses.

METHODS

This systematic review was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were searched up to November 2023. Articles were eligible for inclusion if they were comparing double-row staple and triple-row staple technology for left-sided colo-colic, colorectal, or coloanal anastomosis. The main outcomes included anastomotic leak, anastomotic hemorrhage, 30-day mortality, and reoperation. Meta-analyses with inverse variance random effects were performed. Certainty of evidence was assessed with Grading of Recommendations, Assessment, Development, and Evaluations.

RESULTS

After reviewing 340 relevant citations, 6 retrospective cohort studies met inclusion. Overall, 19,372 patients (mean age: 60.2 years, 52.7% female sex) had anastomoses with double-row staple technology, and 2,298 patients (mean age: 61.3 years, 50.3% female sex) with triple-row staple technology. Most operations were anterior resections (double-row: 55.3%; triple-row: 43.6%). Across all included studies, the risk of anastomotic leak was reduced with triple-row staple technology (6.3% vs 7.5%, risk ratio 0.54, 95% confidence interval 0.31-0.94, P = .03, I2=75%). There were no significant differences in anastomotic hemorrhage (risk ratio 0.47, 95% confidence interval 0.15-1.49, P = .20, I2 = 57%), 30-day mortality (risk ratio 0.66, 95% confidence interval 0.17-2.55, P = .55, I2 = 0%), or reoperation (risk ratio 1.05, 95% confidence interval 0.42-2.64, P = .91, I2 = 56%).

CONCLUSION

Triple-row staple technology may reduce the risk of anastomotic leak in left-sided colorectal anastomoses.

Predicting Postoperative Length of Stay in Patients Undergoing Laparoscopic Right Hemicolectomy for Colon Cancer: A Machine Learning Approach Using SICE (Società Italiana di Chirurgia Endoscopica) CoDIG Data

The evolution of laparoscopic right hemicolectomy, particularly with complete mesocolic excision (CME) and central vascular ligation (CVL), represents a significant advancement in colon cancer surgery. The CoDIG 1 and CoDIG 2 studies highlighted Italy's progressive approach, providing useful findings for optimizing patient outcomes and procedural efficiency. Within this context, accurately predicting postoperative length of stay (LoS) is crucial for improving resource allocation and patient care, yet its determination through machine learning techniques (MLTs) remains underexplored. This study aimed to harness MLTs to forecast the LoS for patients undergoing right hemicolectomy for colon cancer, using data from the CoDIG 1 (1224 patients) and CoDIG 2 (788 patients) studies. Multiple MLT algorithms, including random forest (RF) and support vector machine (SVM), were trained to predict LoS, with CoDIG 1 data used for internal validation and CoDIG 2 data for external validation. The RF algorithm showed a strong internal validation performance, achieving the best performances and a 0.92 ROC in predicting long-term stays (more than 5 days). External validation using the SVM model demonstrated 75% ROC values. Factors such as fast-track protocols, anastomosis, and drainage emerged as key predictors of LoS. Integrating MLTs into predicting postoperative LOS in colon cancer surgery offers a promising avenue for personalized patient care and improved surgical management. Using intraoperative features in the algorithm enables the profiling of a patient's stay based on the planned intervention. This issue is important for tailoring postoperative care to individual patients and for hospitals to effectively plan and manage long-term stays for more critical procedures.

The impact of anastomotic leakage characteristics on the occurrence of anastomotic stenosis after colorectal resection, a retrospective cohort study

INTRODUCTION

Anastomotic stenosis (AS) is a common complication after colorectal resection. However, the predisposing factors for stricture formation are not fully understood. Previous studies have shown anastomotic leakage (AL) to be a risk factor for the occurrence of AS. Therefore, we aim to investigate the impact of anastomotic leakage characteristics on the occurrence of anastomotic stenosis after colorectal resection.

METHODS

Consecutive patients with AL following elective, sphincter preserving, colorectal resection, with or without diversion ostomy, between January 2009 and March 2023 were identified from a prospectively collected database. The characteristics of the anastomotic leakage, patient baseline and operative characteristics as well as the postoperative outcomes were analyzed using univariate and multivariate logistic regression to identify factors associated with the occurrence of post-leakage AS.

RESULTS

A total of 129 patients developed AL and met the inclusion criteria. Among these, 28 (21.7%) patients were diagnosed with post-leakage AS. There was a significantly higher frequency of patients with neoadjuvant radiotherapy (18% vs 3%; p = .026) and hand-sewn anastomoses (39% vs 17%; p = .011) within the AS group. Furthermore, the extent of the anastomotic defect was significantly higher in the AS group compared with the non-AS group (50%, IQR 27-71 vs. 20%, IQR 9-40, p = 0.011). Similar findings were observed between the study groups regarding age, sex, BMI, ASA score, medical comorbidities, diagnosis, surgical procedure, surgical approach (open vs. minimally invasive), and anastomotic fashioning (side-to-end vs. end-to-end). On multivariate analysis, the extent of the anastomotic defect (OR 1.01; 95% CI 1.00-1.03; p = 0.034) and hand-sewn anastomoses (OR 2.68; 95% CI 1.01-6.98; p = 0.043) were confirmed as independent risk factors for post-leakage AS. No correlation could be observed between the occurrence of post-leakage AS and the ISREC grading of AL, the anastomotic height or the management of AL. Time to ostomy reversal was significantly longer in the AS group (202d, IQR 169-275 vs. 318d IQR 192-416, p = 0.014).

CONCLUSION

The extent of the anastomotic defect and hand-sewn anastomoses were confirmed as independent risk factors for the occurrence of post-leakage AS. No correlation could be observed between the ISREC grading of AL, the anastomotic height or AL management, and the occurrence of post-leakage AS.

Colorectal anastomotic leakage: a narrative review of definitions, grading systems, and consequences of leaks

Background

Anastomotic leaks (ALs) are a significant and feared postoperative complication, with incidence of up to 30% despite advances in surgical techniques. With implications such as additional interventions, prolonged hospital stays, and hospital readmission, ALs have important impacts at the level of individual patients and healthcare providers, as well as healthcare systems as a whole. Challenges in developing unified definitions and grading systems for leaks have proved problematic, despite acknowledgement that colorectal AL is a critical issue in intestinal surgery with serious consequences. The aim of this study was to construct a narrative review of literature surrounding definitions and grading systems for ALs, and consequences of this postoperative complication.

Methods

A literature review was conducted by examining databases including PubMed, Web of Science, OVID Embase, Google Scholar, and Cochrane library databases. Searches were performed with the following keywords: anastomosis, anastomotic leak, colorectal, surgery, grading system, complications, risk factors, and consequences. Publications that were retrieved underwent further assessment to ensure other relevant publications were identified and included.

Results

A universally accepted definition and grading system for ALs continues to be lacking, leading to variability in reported incidence in the literature. Additional factors add to variability in estimates, including differences in the anastomotic site and institutional/individual differences in operative technique. Various groups have worked to publish guidelines for defining and grading AL, with the International Study Group of Rectal Cancer (ISGRC/ISREC) definition the current most recommended universal definition for colorectal AL. The burden of AL on patients, healthcare providers, and hospitals is well documented in evidence from leak consequences, such as increased morbidity and mortality, higher reoperation rates, and increased readmission rates, among others.

Conclusions

Colorectal AL remains a significant challenge in intestinal surgery, despite medical advancements. Understanding the progress made in defining and grading leaks, as well as the range of negative outcomes that arise from AL, is crucial in improving patient care, reduce surgical mortality, and drive further advancements in earlier detection and treatment of AL.

Abdominal drainage after elective colorectal surgery: propensity score-matched retrospective analysis of an Italian cohort

BACKGROUND

In Italy, surgeons continue to drain the abdominal cavity in more than 50 per cent of patients after colorectal resection. The aim of this study was to evaluate the impact of abdominal drain placement on early adverse events in patients undergoing elective colorectal surgery.

METHODS

A database was retrospectively analysed through a 1:1 propensity score-matching model including 21 covariates. The primary endpoint was the postoperative duration of stay, and the secondary endpoints were surgical site infections, infectious morbidity rate defined as surgical site infections plus pulmonary infections plus urinary infections, anastomotic leakage, overall morbidity rate, major morbidity rate, reoperation and mortality rates. The results of multiple logistic regression analyses were presented as odds ratios (OR) and 95 per cent c.i.

RESULTS

A total of 6157 patients were analysed to produce two well-balanced groups of 1802 patients: group (A), no abdominal drain(s) and group (B), abdominal drain(s). Group A versus group B showed a significantly lower risk of postoperative duration of stay >6 days (OR 0.60; 95 per cent c.i. 0.51-0.70; P < 0.001). A mean postoperative duration of stay difference of 0.86 days was detected between groups. No difference was recorded between the two groups for all the other endpoints.

CONCLUSION

This study confirms that placement of abdominal drain(s) after elective colorectal surgery is associated with a non-clinically significant longer (0.86 days) postoperative duration of stay but has no impact on any other secondary outcomes, confirming that abdominal drains should not be used routinely in colorectal surgery.

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.

Single-stapled anastomosis is associated with a lower anastomotic leak rate than double-stapled technique after minimally invasive total mesorectal excision for MRI-defined low rectal cancer

BACKGROUND

After total mesorectal excision, distal rectal transection and anastomosis are critical for short-term, oncological, and functional outcomes, including anastomotic leak. A double-pursestring, single-stapled anastomosis avoids cross-stapling, overcoming the potential drawbacks of transabdominal rectal transection and double-stapled anastomosis. This study aims to compare the anastomotic leak rate in double-stapled and single-stapled anastomoses after minimally invasive total mesorectal excision for magnetic resonance imaging-defined low rectal cancer.

METHODS

Adult patients (>18 years old) undergoing minimally invasive total mesorectal excision for magnetic resonance imaging-defined low rectal cancer with a stapled low anastomosis (below 5 centimeters from the anal verge) between January 2010 and January 2022 at a single institution were allocated to 2 groups according to the anastomosis: double-stapled (abdominal stapled transection and double-stapled anastomosis) or single-stapled (transanal rectal transection and double-pursestring single-stapled anastomosis). The exclusion criteria were nonrestorative procedures or any type of manual anastomosis. The primary endpoint was the rate of 90-day clinical and radiologic anastomotic leak.

RESULTS

In total, 185 single-stapled and 458 double-stapled were included. Clinical and tumor characteristics were comparable between the groups. The 90-day anastomotic leak rate was significantly lower in the single-stapled group (6.48% vs 15.28%; P = .002), with similar rates of grade and timing. Thirty- and 90-day complication rates were higher in the double-stapled group (P = .0001; P = .02), with comparable Clavien-Dindo grades. At multivariable analysis, double-stapled anastomosis (P = .01), active smoking (P = .03), and the presence of comorbidities (P = .01) resulted as independent risk factors for an anastomotic leak.

CONCLUSION

Transanal transection and double-pursestring, single-stapled anastomosis were associated with a lower anastomotic leak rate after minimally invasive total mesorectal excision for magnetic resonance imaging-defined low rectal cancer.

Development of a warning score for early detection of colorectal anastomotic leakage: Hype or hope?

BACKGROUND

Colorectal anastomotic leakage (CAL), a severe postoperative complication, is associated with high morbidity, hospital readmission, and overall healthcare costs. Early detection of CAL remains a challenge in clinical practice. However, some decision models have been developed to increase the diagnostic accuracy of this event.

AIM

To develop a score based on easily accessible variables to detect CAL early.

METHODS

Based on the least absolute shrinkage and selection operator method, a predictive classification system was developed [Early ColoRectAL Leakage (E-CRALL) score] from a prospective observational, single center cohort, carried out in a colorectal division from a non-academic hospital. The score performance and CAL threshold from postoperative day (POD) 3 to POD5 were estimated. Based on a precise analytical decision model, the standard clinical practice was compared with the E-CRALL adoption on POD3, POD4, or POD5. A cost-minimization analysis was conducted, on the assumption that all alternatives delivered similar health-related effects.

RESULTS

In this study, 396 patients who underwent colorectal resection surgery with anastomosis, and 6.3% (n = 25) developed CAL. Most of the patients who developed CAL (n = 23; 92%) were diagnosed during the first hospital admission, with a median time of diagnosis of 9.0 ± 6.8 d. From POD3 to POD5, the area under the receiver operating characteristic curve of the E-CRALL score was 0.82, 0.84, and 0.95, respectively. On POD5, if a threshold of 8.29 was chosen, 87.4% of anastomotic failures were identified with E-CRALL adoption. Additionally, score usage could anticipate CAL diagnosis in an average of 5.2 d and 4.1 d, if used on POD3 and POD5, respectively. Regardless of score adoption, episode comprehensive costs were markedly greater (up to four times) in patients who developed CAL in comparison with patients who did not develop CAL. Nonetheless, the use of the E-CRALL warning score was associated with cost savings of €421442.20, with most (92.9%) of the savings from patients who did not develop CAL.

CONCLUSION

The E-CRALL score is an accessible tool to predict CAL at an early timepoint. Additionally, E-CRALL can reduce overall healthcare costs, mainly in the reduction of hospital costs, independent of whether a patient developed CAL.

Single center experience with salvage surgery for chronic pelvic sepsis

Chronic pelvic sepsis eventually requires salvage surgery in half of all patients. The goal of surgery is to resolve pelvic inflammation while restoring intestinal continuity. Our salvage procedure achieves this by bringing a healthy conduit into the pelvis and creating an anastomosis beyond the source of sepsis. We aimed to review our single center experience with this procedure for the treatment of chronic pelvic sepsis. All patients requiring the procedure from 2010 to 2018 were retrospectively reviewed using a prospective database. Morbidity and mortality were evaluated, and restoration of bowel continuity at 1-year rate was the endpoint. Twenty patients were included. The main indication was pelvic sepsis after anastomotic leak (AL). The median age was 60 (42-86) years and the median BMI was 26 (18-37) kg/m². The median time carrying a stoma before the intervention was 15 months, and median time to intervention was 32 months. All patients had a diverting stoma. There were no death and overall morbidity reached 60%, and AL rate was 10%. At 1 year, 70% of the patients had their intestinal continuity restored. In expert hands, salvage surgery for chronic pelvic sepsis has acceptable morbidity rates, an acceptable rate of AL, and a bowel restoration success rate 70% at 1 year, and is a valuable option for patients failing conservative treatment.

Short-term outcomes in patients undergoing laparoscopic surgery for deep infiltrative endometriosis with rectal involvement: a single-center experience of 168 cases

Purpose

The surgical management of deep infiltrative endometriosis (DE) involving the rectum remains a challenge. The objective of this study was to assess the outcomes from a single tertiary center over a decade with an emphasis on the role of a protective loop ileostomy (PI).

Methods

A retrospective review of outcomes for 168 patients managed between 2008 and 2018 is presented including 57 rectal shaves, 23 discoid excisions, and 88 segmental rectal resections.

Results

The nodule size (mean±standard deviation) in the segmental resection group was 32.7±11.2 mm, 23.4±10.5 mm for discoid excision, and 18.8±6.0 mm for rectal shaves. A PI was performed in 19 elective cases (11.3%) usually for an ultra-low anastomosis <5 cm from the anal verge. All Clavien-Dindo grade III/IV complications occurred after segmental resections and included 5 anastomotic leaks, 6 rectovaginal fistulas, 2 ureteric fistulas, and 1 ureteric stenosis. Of 26 stomas (15.5%), there were 19 PIs, 3 secondary ileostomies (after complications), and 4 end colostomies. The median time to PI closure was 5.8 months (range, 0.4-16.7 months) in uncomplicated disease compared with 9.2 months (range, 4.7-18.4 months) when initial postoperative complications were recorded (P=0.019). Only 1 patient with a recurrent rectovaginal fistula had a permanent colostomy.

Conclusion

In patients with DE and rectal involvement a PI is selectively used for low anastomoses and complex pelvic reconstructions. Protective stomas and those used in the definitive management of a major postoperative complication can usually be reversed.

Defining Anastomotic Leak and the Clinical Relevance of Leaks

Surgeons universally dread gastrointestinal anastomotic leaks, yet the precise definition is not widely agreed on despite international consensus guidelines. Likewise, leaks are not uniformly reported which makes comparisons across studies flawed. Leak rates range from 1 to 3% for ileocolonic, 0.5 to 18% for colorectal, and 5 to 19% for coloanal anastomoses. The sequelae of an anastomotic leak vary but generally correlate with the need for a change in clinical management, from minimal changes to the need for reoperation. Short- and long-term outcomes can be life-altering or life-threatening. Temporary or permanent stomas may be necessary and low pelvic anastomotic leaks may affect bowel function. For cancer patients, leaks can delay treatment and negatively affect oncologic outcomes. In Crohn's patients, leaks are associated with higher recurrence rates. In essence, the lack of agreement on the definition of an anastomotic leak inhibits meaningful understand of its epidemiology, prevention, and treatment.

The use of mesenchymal stem cells in animal models for gastrointestinal anastomotic leak: A systematic review

AIM

Anastomotic leak is the most feared complication of gastrointestinal surgery. Mesenchymal stem cell technology is used clinically to promote wound healing; however, the safety and efficacy of this technology on anastomotic healing has yet to be defined. The aim of this study was to investigate whether mesenchymal stem cells confer any benefit when applied to animal models for gastrointestinal anastomotic leak, identify the methodology and how efficacy is assessed.

METHODS

The MEDLINE, EMBASE, WebofScience and Cochrane Library databases were interrogated between 1 January1947 to 1 May 2020. All studies where mesenchymal stem cells were applied to laboratory animal leak models to demonstrate a healing effect were considered. All experimental and histological outcomes were examined. Compliance to ARRIVE and current International Consensus was assessed.

RESULTS

A total of 1205 studies were screened. Twelve studies reported on 438 gastrointestinal anastomoses in four species using 11 models; seven in the colon. No studies utilised a model with a known leak rate. Significant variance was observed in histological outcomes with efficacy demonstrated in five out of 12 studies. One study demonstrated a benefit in leak rate. Colorectal studies had a greater median ARRIVE compliance, 60.8% (IQR 63.2-64.5) compared to noncolorectal 45.4% (IQR 43.8-49.0).

CONCLUSIONS

Mesenchymal stem cell delivery to an animal anastomosis is safe and feasible. Use may confer benefit but findings are currently limited to surrogate histological outcomes. There is consistency in outcome measures reported but variance in how this is assessed. Poor compliance to ARRIVE but good compliance to current international consensus in leak models of the colon was observed.

Obesity and anastomotic leak rates in colorectal cancer: a meta-analysis

PURPOSE

Anastomotic leak (AL) following colorectal cancer resection is associated with considerable morbidity and mortality with an impact on recurrence rates and survival. The impact of obesity on AL rates is debated. This meta-analysis aims to investigate the relationship between obesity and AL.

METHODS

A search was conducted of the PubMed/MEDLINE, and Web of Science databases and included studies were split into Western and Asian groups based on population-specific body mass index (BMI) ranges for obesity. A meta-analysis was performed to assess the impact of obesity on AL rate following colorectal cancer resection.

RESULTS

Two thousand three hundred and four articles were initially screened. Thirty-one studies totaling 32,953 patients were included. Patients with obesity had a statistically significant increase in AL rate in all Western and Asian study groups. However, this increase was only clinically significant in the rectal anastomotic subgroups-Western: 10.8% vs 8.4%, OR 1.57 (1.01-2.44) and Asian: 9.4% vs 7.4%, OR 1.58 (1.07-2.32).

CONCLUSIONS

The findings of this analysis confirm that obesity is a significant risk factor for anastomotic leak, particularly in rectal anastomoses. This effect is thought to be primarily mediated via technical difficulties of surgery although metabolic and immunological factors may also play a role. Obesity in patients undergoing restorative CRC resection should be discussed and considered as part of the pre-operative counselling.

The importance of rectal contrast in CT assessment to detect anastomotic leakage after colorectal surgery

AIM

Computed tomography (CT) is currently the diagnostic tool most often used to detect anastomotic leakage (AL) after colorectal surgery. The aim of this study was to investigate the value of rectal contrast.

METHOD

All patients who underwent colorectal surgery with a primary anastomosis between 2009 and 2018 were identified from a prospectively maintained database. Patients who underwent postoperative CT scanning in suspicion of AL were included. The clinical and radiological outcomes of patients with and without rectal contrast were compared.

RESULTS

A total of 1183 patient records were reviewed; 225 patients underwent CT-abdomen in suspicion of AL. Of these patients, 175 (77.8%) received rectal contrast. Sensitivity and specificity in this group were 78% and 94%, respectively. The positive predictive value (PPV) was 0.78 and the negative predictive value (NPV) was 0.94. In the group without rectal contrast (n = 50), sensitivity was 47%, specificity 88%, PPV 0.66 and NPV 0.76. In patients who received rectal contrast, contrast reached the anastomosis in 81.7% compared with 26.0% in patients who were given only oral contrast (p < 0.001). The sensitivity increased to 93% in the group of patients with contrast at the anastomosis, the specificity to 97%, the PPV to 0.88 and the NPV to 0.98. No adverse events were observed after the use of rectal contrast.

CONCLUSION

The use of rectal contrast led to a significant increase in the predictive value of CT scanning for AL, especially when it reached the anastomosis. This suggests that rectal contrast is a safe and useful adjunct to CT-abdomen in the detection of AL.

Association of the collagen score with anastomotic leakage in rectal cancer patients after neoadjuvant chemoradiotherapy

BACKGROUND

Collagen changes in the extracellular matrix caused by neoadjuvant chemoradiotherapy are a potential mechanism of anastomotic leakage. We aimed to construct a fully quantitative collagen score to describe collagen structure changes in the extracellular matrix and then develop and validate a prediction model to identify patients who are at a high risk of postoperative anastomotic leakage.

METHODS

This is a retrospective study in which 372 patients were enrolled, and their baseline clinicopathological characteristics were collected. Anastomotic distal and proximal "doughnut" specimens underwent second harmonic generation imaging, and collagen features were extracted. A LASSO regression was used to select significant predictors, and the collagen score was constructed. A prediction model based on collagen score was developed and internally and externally validated.

RESULTS

The primary cohort included 214 consecutive patients, and the anastomotic leakage rate was 8.9%. The validation cohort comprised 158 consecutive patients, and the anastomotic leakage rate was 10.1%. The collagen score was significantly related to anastomotic leakage in both cohorts (P < .001). Multivariate analysis revealed that tumor location, preoperative albumin, and collagen score were independent predictors of anastomotic leakage. These 3 predictors were incorporated into the prediction model, and a nomogram was established. The model showed good discrimination in the primary (area under the curve: 0.954) and validation (area under the curve: 0.928) cohorts. Decision curve analysis demonstrated that the nomogram was clinically useful.

CONCLUSION

The collagen score is associated with anastomotic leakage, and the collagen nomogram based on the collagen score is useful for individualized prediction of anastomotic leakage in rectal cancer patients with neoadjuvant chemoradiotherapy after surgery.

Surgery for Colorectal Cancer: A Trigger for Liver Metastases Development? New Insights into the Underlying Mechanisms

Surgery is a crucial intervention and provides the best chance of cure for patients with colorectal cancer. Experimental and clinical evidence, however, suggests that paradoxically surgery itself may precipitate or accelerate tumor recurrence and/or liver metastasis development. This review addresses the various aspects of surgery-induced metastasis formation and sheds light on the role of inflammation as potential trigger for metastasis development. Understanding these mechanisms may provide potential new perioperative interventions to improve treatment outcomes, and as such could transform the perioperative timeframe from a facilitator of metastatic progression to a window of opportunity to reduce the risk of liver metastasis development. Ultimately, this can potentially improve long-term survival rates and quality of life in patients with colorectal cancer.

End-to-end versus end-to-side anastomosis for low anterior resection: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Numerous randomized controlled trials comparing end-to-end and end-to-side anastomoses after low anterior resection have been performed. Rates of anastomotic leakage and overall postoperative morbidity, as well as reported quality of postoperative bowel function, vary across individual studies. As such, this study meta-analyzes pooled data comparing end-to-end and end-to-side anastomosis after low anterior resection in terms of anastomotic leak rate and postoperative bowel function.

METHODS

A search of Medline, EMBASE, and Cochrane Central Register of Controlled Trials was performed. Articles were included if they were randomized controlled trials that compared end-to-end and end-to-side anastomosis after low anterior resection for benign or malignant disease. The primary outcome was anastomotic leak rate. A pairwise meta-analysis was performed using inverse variance random effects.

RESULTS

From 1,452 citations, 6 randomized controlled trials with 270 patients undergoing end-to-end anastomosis (45.9% female, mean age: 63.5 years) and 268 patients undergoing end-to-side anastomosis (52.4% female, mean age: 64.0 years) met inclusion criteria. Patients undergoing end-to-side anastomosis had a significantly lower rate of anastomotic leak (RR 0.37, 95% CI 0.15-0.93, P = .04, I²=0%). There were no differences in rate of anastomotic stenosis (RR 1.03, 95% CI 0.21-5.19, P = .97) or overall postoperative morbidity (RR 0.60, 95% CI 0.33-1.07, P = .08). Narrative review of postoperative bowel function demonstrated evidence of improved Wexner scores for 6 months postoperatively in patients undergoing end-to-side anastomosis.

CONCLUSION

End-to-side anastomosis significantly reduces the risk of anastomotic leak after low anterior resection. Additional prospective trials are warranted to confirm the findings of this review and to contribute to the growing evidence-base aimed at optimization of bowel function after low anterior resection.

Laparoscopic colorectal resection for deep infiltrating endometriosis: can we reliably predict anastomotic leakage and major postoperative complications in the early postoperative period?

BACKGROUND

Anastomotic leakage (AL) and major complications after colorectal resection for deep infiltrating endometriosis (DIE) have a remarkable impact on patient outcomes. The aim of this study is to assess the predictive value of C-reactive protein (CRP), procalcitonin (PCT), white blood cell count (WBCs) and the Dutch Leakage Score (DLS) as reliable markers in the early diagnosis of AL and major complications after laparoscopic colorectal resection for DIE.

METHODS

262 consecutive women undergoing laparoscopic colorectal resection for DIE between September 2017 and September 2018 were prospectively enrolled. WBCs, CRP, PCT and DLS were recorded at baseline and on postoperative day (POD) 2, 3 and 6 then statistically analyzed as predictors of AL and severe postoperative complications.

RESULTS

The AL rate was 3.2%. The major morbidity rate was 11.2%. No postoperative mortality was recorded. The postoperative trend of DLS and serum levels of CRP and PCT, but not WBCs, were significantly higher in women developing AL and severe complications. DLS had better sensitivity and specificity than biomarkers on all postoperative days as a predictor of AL and major complications. CRP and PCT have a low positive predictive value (PPV) and a high negative predictive value (NPV) for AL and major complications on POD3 and POD6. The risk of malnutrition was significantly related to AL.

CONCLUSIONS

The combination of DLS as a standardized postoperative clinical monitoring system and CRP and PCT as serum biomarkers, allows the exclusion of AL and major complications in the early postoperative period after laparoscopic colorectal resection for DIE, thus ensuring a safe patient discharge.

Outcomes of Intra- versus Extra-Corporeal Ileocolic Anastomosis after Minimally Invasive Right Colectomy for Cancer: An Observational Study

Intracorporeal anastomoses (IA) are increasingly being used in colorectal surgery. Some data suggest that these might confer benefits compared with extracorporeal anastomoses (EA). The aim of this study is to compare the short-term complications associated with IA versus EA for minimally invasive right colectomy. This is a single-centre, retrospective study on a prospective database. Patients who underwent minimally invasive right colectomy for cancer between January 2017 and December 2019 were assessed for inclusion. The primary outcome was global 30-day morbidity. Overall, 189 patients were included, of whom 102 had IA. Global morbidity and medical complications were higher in patients with EA (23.5% vs. 40.2%, p = 0.014; 5.9% vs. 14.9%, p = 0.039, respectively). None of the patients with IA had non-infectious surgical wound complications, compared to 4.6% in the EA group (p = 0.029). No differences were found in anastomotic leakage (9.8% vs. 10.3%, p = 0.55). At multivariable analysis, EA was an independent risk factor for both surgical (OR = 3.71 95% CI: 1.06-12.91, p = 0.04) and overall complications (OR = 3.58 95% CI: 1.06-12.12, p = 0.04). IA lowers the risk for global, medical, and surgical complications with minimum risk for wound complications, without increasing the risk of AL.

Defining Anastomotic Leaks After Colorectal Surgery: Results of a National Survey

BACKGROUND

Anastomotic leaks are a dreaded complication after colorectal surgery. Although anastomotic leak is often used as a metric to compare patient outcomes, a standard definition does not exist.

MATERIALS AND METHODS

A web-based survey was developed and distributed to US surgeons. Respondents were queried on the definition of anastomotic leaks using a 5-point Likert scale to rate different scenarios related to colorectal surgery.

RESULTS

Of potential 2209 respondents, 649 (29%) responded to the survey. The majority of respondents was men (76%) and practiced colon and rectal surgery as their primary specialty (89%). Contrast extravasation at the anastomosis, regardless of timing related to the surgery, is the clinical scenario with greatest consensus (>85%). 50% of surgeons do not believe that an abscess near the anastomosis in an asymptomatic patient defines a leak.

CONCLUSIONS

These results highlight the pressing need for standardization of the anastomotic leak definition given the implications on outcomes measurement, research trials, and health care reimbursement.

Anastomotic Leakage After Laparoscopic Colectomy: Who Will Require Emergency Fecal Diversion?

Background: To identify predictive factors for reoperation because of anastomotic leakage (AL) after colectomy. Methods: Between 2007 and 2016, all patients who developed AL following right or left colectomy in an expert center were included. Patients who were treated surgically (all including fecal diversion) were compared with those who were managed conservatively. Results: Overall, 81 (6.5%) patients developed AL, of which 32 (39%) were managed nonoperatively and 49 (61%) required reoperation. On average, AL was diagnosed on postoperative day 4 (3-8) and mortality reached 4.9% (n = 4). Reoperation included anastomosis resection in 31 (67%) patients of which 26 (100%) had right colectomy and 5 (25%) left colectomy. Reoperation for AL was associated with increased intensive care management (P = .026) and deep abdominal collection (P = .002). T stage >2 and right-sided colectomy were the only independent risk factors associated with the need for reoperation for AL. Stoma reversal was performed in 42 (98%) patients after a median of 4 months. Conclusions: AL after colectomy is more likely to require reoperation with fecal diversion after right-sided colectomy and T > 2 colorectal cancer.

Validation of MTL30 as a quality indicator for colorectal surgery

Background

Valid indicators are required to measure surgical quality. These ideally should be sensitive and selective while being easy to understand and adjust. We propose here the MTL30 quality indicator which takes into account 30-day mortality, transfer within 30 days, and a length of stay of 30 days as composite markers of an uneventful operative/postoperative course.

Methods

Patients documented in the StuDoQ|Colon and StuDoQ|Rectal carcinoma register of the German Society for General and Visceral Surgery (DGAV) were analyzed with regard to the effects of patient and tumor-related risk factors as well as postoperative complications on the MTL30.

Results

In univariate analysis, the MTL30 correlated significantly with patient and tumor-related risk factors such as ASA score (p<0.001), age (p<0.001), or UICC stage (p<0.001). There was a high sensitivity for the postoperative occurrence of complications such as re-operations (p<0.001) or subsequent bleeding (p<0.001), as well as a significant correlation with the CDC classification (p<0.001). In multivariate analysis, patient-related risk factors and postoperative complications significantly increased the odds ratio for a positive MTL30. A negative MTL30 showed a high specify for an uneventful operative and postoperative course.

Conclusion

The MTL30 is a valid indicator of colorectal surgical quality.

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.

Consensus on the definition of colorectal anastomotic leakage: A modified Delphi study

BACKGROUND

Despite the emerging knowledge about colorectal anastomotic leakage (CAL) through the increasing number of clinical and experimental studies, there is no generally accepted definition of CAL. Because of the wide variety of definitions used in literature, comparison of study outcomes and quality of care is complicated.

AIM

To reach consensus on the definition of CAL using a modified Delphi method.

METHODS

The RAND/UCLA appropriateness method was used. The expert panel consisted of international colorectal surgeons and researchers who had published three or more articles about CAL. The consensus process consisted of two online distributed questionnaires and a third round with a recommendation. In the questionnaires participants were asked to rate the appropriateness of statements using a 1-9 Likert scale. Consensus was defined as a panel median between 1-3 or 7-9 without disagreement. In the final round a recommendation was formed regarding the definition of CAL and the expert panel was asked if they agreed or disagreed.

RESULTS

Twenty-three authors participated in the first round and twenty-one finished the second round. After two rounds consensus was reached on 37 items (80%) in nine different categories. The International Study Group of Rectal Cancer definition is the most frequently advised general definition by our panel. Consensus was reached regarding the clinical symptoms of CAL, which serum markers contributes to the suspicion of CAL, which radiological and perioperative findings should be considered as CAL, which grading system is appropriate and if there should be a range of postoperative days in the definition. Eventually, 19 experts completed all three rounds of which 16 (84%) agreed with our final recommendations for the definition of CAL.

CONCLUSION

A consensus-based recommendation for the definition of CAL was formed using our modified Delphi method that can be widely incorporated in the field.

Anastomotic leak in colorectal cancer patients: New insights and perspectives

Anastomotic leak (AL) remains a potentially life-threatening sequela of colorectal surgery impacting on mortality, short- and long-term morbidity, quality of life, local recurrence (LR) and disease-free survival. Despite technical improvements and the identification of several surgery- and patient-related factors associated to the risk of AL, its incidence has not significantly changed over time. In this context, the clarification of the mechanisms underlying anastomotic healing remains an important unmet need, crucial for improving patients' outcomes. This review concentrates on novel key findings in the etiopathogenesis of AL, how they can contribute in determining LR, and measures which may contribute to reducing its incidence. AL results from a complex, dynamic interplay of several factors and biological processes, including host genetics, gut microbiome, inflammation and the immune system. Many of these factors seem to act in concert to drive both AL and LR, even if the exact mechanisms remain to be elucidated. The next generation sequencing technology, including the microbial metagenomics, could lead to tailored bowel preparations targeting only those pathogens that can cause AL. Significant progress is being made in each of the reviewed areas, moving toward translational and targeted therapeutic strategies to prevent the difficult complication of AL.

Experimental fortification of intestinal anastomoses with nanofibrous materials in a large animal model

Anastomotic leakage is a severe complication in gastrointestinal surgery. It is often a reason for reoperation together with intestinal passage blockage due to formation of peritoneal adhesions. Different materials as local prevention of these complications have been studied, none of which are nowadays routinely used in clinical practice. Nanofabrics created proved to promote healing with their structure similar to extracellular matrix. We decided to study their impact on anastomotic healing and formation of peritoneal adhesions. We performed an experiment on 24 piglets. We constructed 3 hand sutured end-to-end anastomoses on the small intestine of each pig. We covered the anastomoses with a sheet of polycaprolactone nanomaterial in the first experimental group, with a sheet of copolymer of polylactic acid with polycaprolactone in the second one and no fortifying material was used in the Control group. The animals were sacrificed after 3 weeks of observation. Clinical, biochemical and macroscopic signs of anastomotic leakage or intestinal obstruction were monitored, the quality of the scar tissue was assessed histologically, and a newly developed scoring system was employed to evaluate the presence of adhesions. The material is easy to manipulate with. There was no mortality or major morbidity in our groups. No statistical difference was found inbetween the groups in the matter of level of peritoneal adhesions or the quality of the anastomoses. We created a new adhesion scoring system. The material appears to be safe however needs to be studied further to prove its' positive effects.

Virtual ileostomy in elective colorectal surgery: a systematic review of the literature

BACKGROUND

Anastomotic leak (AL) following colorectal surgery can be a life-threatening complication. The use of a diverting stoma has been proposed, to prevent or reduce morbidity and mortality associated with AL. Stomas, however, have their own distinct complications. Thus, virtual ileostomy (VI) has been proposed as an alternative to diverting stoma. The aim of the present study was to further evaluate the role of VI through systematic review of existing literature.

METHODS

A systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the Cochrane handbook for systematic reviews of interventions. The primary endpoint of our study was the estimation of the overall VI complication rate. Secondary endpoints included the identification of the VI-specific adverse outcomes, perioperative endpoints such as the length of hospital stay, transfusion and postoperative leak rates, description of the operative variations of VI reported VI operative variations and details regarding the primary operation and previous neoadjuvant therapy.

RESULTS

In total, 11 studies and 554 patients were included in this systematic review. Overall, 158 laparoscopic and 191 open procedures were performed. The AL and VI conversion rates were 11.9% and 10.46%, respectively. The total complication rate was estimated to be 13.9%, while VI-specific adverse events were recorded in 2.1% of all cases.

CONCLUSIONS

VI could be a safe and effective alternative to a diverting stoma. Although currently, VI is not widely used, it could have a widespread application in laparoscopic surgery. However, definitive trials are needed before firm recommendations on the use of VI can be made.

Novel nomogram with microvascular density in the surgical margins can accurately predict the risk for anastomotic leakage after anterior resection for rectal cancer

BACKGROUND

Anastomotic leakage (AL) is a serious complication after anterior resection. The purpose of this study was to determine the role of microvascular density (MVD) in AL and to develop a nomogram to accurately predict AL.

METHODS

This study retrospectively enrolled 477 consecutive patients who underwent anterior resection for rectal cancer from January 2011 to January 2019. Tissue samples of the resection margins were assessed for MVD. Univariate and multivariate regression analyses were used to identify the risk factors for AL.

RESULTS

The incidence of clinical AL was 6.7%. MVD in the distal margin was associated with AL (P < .001). Univariate and multivariate regression analysis identified the following variables as independent risk factors for AL: preoperative albumin ≤35 g/L (odds ratio [OR] = 2.511), neoadjuvant treatment (OR = 3.560), location of tumor ≤7 cm (OR = 3.381), blood loss ≥100 mL (OR = 2.717), and MVD in the distal margin ≤20 (OR = 4.265). Then, a nomogram including these predictors was developed. The nomogram showed good discrimination (AUC = 0.816) and calibration (concordance index = 0.816). The decision curve analysis demonstrated that the nomogram was clinically useful.

CONCLUSIONS

MVD in the distal margin is closely associated with AL. The nomogram can be used for individualized prediction of AL after anterior resection for patients with rectal cancer.

Laparoscopic versus open right hemicolectomy in colon carcinoma: A propensity score analysis of the DGAV StuDoQ|ColonCancer registry

Objective

To assess whether laparoscopy has any advantages over open resection for right-sided colon cancer.

Summary background data

Right hemicolectomy can be performed using either a conventional open or a minimally invasive laparoscopic technique. It is not clear whether these different access routes differ with regard to short-term postoperative outcomes.

Methods

Patients documented in the German Society for General and Visceral Surgery StuDoQ|ColonCancer registry who underwent right hemicolectomy were analyzed regarding early postoperative complications according to Clavien-Dindo (primary endpoint), operation (OP) time, length of postoperative hospital stay (LOS), MTL30 and number of lymph nodes retrieved (secondary endpoints).

Results

A total of 4.997 patients were identified as undergoing oncological right hemicolectomy without additional interventions. Of these, 4.062 (81.3%) underwent open, 935 (18.7%) laparoscopic surgery. Propensity score analysis showed a significantly shorter LOS (OR: 0.55 CI 95%0.47-.64) and a significantly longer OP time (OR2.32 CI 1.98–2.71) for the laparoscopic route. Risk factors for postoperative complications, anastomotic insufficiency, ileus, reoperation and positive MTL30 were higher ASA status, higher age and increasing BMI. The surgical access route (open / lap) had no influence on these factors, but the laparoscopic group did have markedly fewer lymph nodes retrieved.

Conclusion

The present registry-based analysis could detect no relevant advantages for the minimally invasive laparoscopic access route. Further oncological analyses are needed to clarify the extent to which the smaller lymph node harvest in the laparoscopic group is accompanied by a poorer oncological outcome.

Single vs. double purse-string anastomosis during laparoscopic low anterior rectal resection (SINGLE-DOUBLE trial): study protocol for a randomized controlled trial

Background

An inappropriate anastomosis method during laparoscopic anterior rectal resection can increase the risk of anastomotic complications and affect surgical, economic, and oncological outcomes. The aim of this study is to compare the incidence of anastomotic complications and the surgical, economic, and oncological outcomes following single versus double purse-string anastomosis during laparoscopic total mesorectal excision (TME) for low rectal cancer.

Methods/design

This randomized controlled trial (the SINGLE–DOUBLE study) will randomly assign middle and low rectal adenocarcinoma patients to receive either single or double purse-string anastomosis during laparoscopic low anterior rectal resection. Patients will be eligible for inclusion only if they (1) have adenocarcinoma confirmed by preoperative colonoscopy and biopsy, (2) have a tumor situated less than 12 cm from the anal verge, (3) do not have the anal sphincter involved, and (4) do not have distant metastases. The primary endpoint measure will be the incidence of anastomotic complications (leakage, narrowing, and bleeding). The secondary endpoints will be surgical, economic, and oncological outcomes. A total of 500 patients will be enrolled in the study. Sample size calculation was based on previous reports and our retrospective analysis.

Discussion

This randomized single-center controlled trial is expected to demonstrate which anastomosis method (single or double purse-string anastomosis) is better for reducing complications and improving prognosis in rectal cancer patients undergoing laparoscopic TME for low or middle rectal cancer.

Trial registration

Registration number: ChiCTR1800016116. Protocol Registration Receipt: May 13, 2018.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3411-7) contains supplementary material, which is available to authorized users.

Comparison of conventional access routes for right hemicolectomy in colon cancer-data from the DGAV StuDoQ registry

BACKGROUND

Access for right hemicolectomy can be gained by median or transverse incision laparotomy. It is not known whether these routes differ with regard to short-term postoperative outcomes.

METHODS

Patients in the DGAV StuDoQ|ColonCancer registry who underwent open oncological right hemicolectomy by median (n = 2389) or transverse laparotomy (n = 1311) were compared regarding Clavien-Dindo classification (CDC) complications (primary endpoint) as well as specific postoperative complications, operation time, length of stay, and MTL30 status (secondary endpoints).

RESULTS

A total of 3700 StuDoQ registry patients underwent open oncological right hemicolectomy by median (n = 2389) or transverse laparotomy (n = 1311) without additional interventions. The median and transverse access routes did not differ regarding CDC complication rates (CDC &gt; =3a: 13.1% vs. 12.6%; p = 0.90). However, univariate and multivariate analyses showed that operation times (OR 0.71, 95% CI 0.62-0.81; p &lt; 0.001), length of stay (OR 0.69, 95% CI 0.6-079; p &lt; 0.001), and MTL30 (OR 0.7, 95% CI 0.61-0.81, p &lt; 0.001) were significantly reduced in the transverse laparotomy group.

CONCLUSIONS

For oncological right hemicolectomy, open transverse upper abdominal laparotomy appears to be superior to median laparotomy in short-term course.

Effects of anastomotic technique on early postoperative outcome in open right-sided hemicolectomy

Background

Despite recent improvements in colonic cancer surgery, the rate of anastomotic leakage after right hemicolectomy is still around 6–7 per cent. This study examined whether anastomotic technique (handsewn or stapled) after open right hemicolectomy for right‐sided colonic cancer influences postoperative complications.

Methods

Patient data from the German Society for General and Visceral Surgery (StuDoQ) registry from 2010 to 2017 were analysed. Univariable and multivariable analyses were performed. The primary endpoint was anastomotic leakage; secondary endpoints were postoperative ileus, complications and length of postoperative hospital stay (LOS).

Results

A total of 4062 patients who had undergone open right hemicolectomy for colonic cancer were analysed. All patients had an ileocolic anastomosis, 2742 handsewn and 1320 stapled. Baseline characteristics were similar. No significant differences were identified in anastomotic leakage, postoperative ileus, reoperation rate, surgical‐site infection, LOS or death. The stapled group had a significantly shorter duration of surgery and fewer Clavien–Dindo grade I–II complications. In multivariable logistic regression analysis, ASA grade and BMI were found to be significantly associated with postoperative complications such as anastomotic leakage, postoperative ileus and reoperation rate.

Conclusion

Handsewn and stapled ileocolic anastomoses for open right‐sided colonic cancer resections are equally safe. Stapler use was associated with reduced duration of surgery and significantly fewer minor complications.