Reducing anastomotic leak in colorectal surgery: The old dogmas and the new challenges

A review of perioperative immune-modulating and metabolic-modulating nutrition strategies for bowel resection surgery

Focused perioperative nutrition strategies have proven benefits on the outcomes for patients undergoing major abdominal surgery. In this brief article, we will review these strategies and the evidence to support them with a focus on gastrointestinal anastomotic healing. We will elaborate the risks and benefits of enteral feeds, immune- and metabolic-modulating formulas, prebiotics and probiotics, and prehabilitation in preparation for surgery. Additionally, we will discuss the role of fish oils (eicosapentaenoic acid and docosahexaenoic acid) in the surgical patient and new data on specialized proresolving mediators in inflammation resolution. Finally, this article will consider the harmful impact surgical trauma has on the microbiome and the potential for perioperative dietary modulation to attenuate these negative effects.

A nomogram of anastomotic stricture after rectal cancer: a retrospective cohort analysis

BACKGROUND

Anastomotic stricture significantly impacts patients' quality of life and long-term prognosis. However, current clinical practice lacks accurate tools for predicting anastomotic stricture. This study aimed to develop a nomogram to predict anastomotic stricture in patients with rectal cancer who have undergone anterior resection.

METHODS

A total of 1542 eligible patients were recruited for the study. Least absolute shrinkage selection operator (Lasso) analysis was used to preliminarily select predictors. A prediction model was constructed using multivariate logistic regression and presented as a nomogram. The performance of the nomogram was evaluated using receiver operating characteristic (ROC) curves, calibration diagrams, and decision curve analysis (DCA). Internal validation was conducted by assessing the model's performance on a validation cohort.

RESULTS

72 (4.7%) patients were diagnosed with anastomotic stricture. Participants were randomly divided into training (n = 1079) and validation (n = 463) sets. Predictors included in this nomogram were radiotherapy, diverting stoma, anastomotic leakage, and anastomotic distance. The area under the ROC curve (AUC) for the training set was 0.889 [95% confidence interval (CI) 0.840-0.937] and for the validation set, it was 0.930 (95%CI 0.879-0.981). The calibration curve demonstrated a strong correlation between predicted and observed outcomes. DCA results showed that the nomogram had clinical value in predicting anastomotic stricture in patients after anterior resection of rectal cancer.

CONCLUSION

We developed a predictive model for anastomotic stricture following anterior resection of rectal cancer. This nomogram could assist clinicians in predicting the risk of anastomotic stricture, thus improving patients' quality of life and long-term prognosis.

Preliminary results of Polish national multicenter study on colostomy reversal - LICO (Liquidation of Colostomy) study

Introduction

Creation of colostomy is still a commonly performed procedure in emergency settings, when intestinal anastomosis cannot be performed safely. Reversing a stoma has been linked with high rates of morbidity and also mortality.

Aim

The primary goal of the study was to identify the risk of postoperative complications in patients undergoing colostomy liquidation. The secondary goal was to assess perioperative care parameters.

Material and methods

The LIquidation of COlostomy (LICO) study is an open multicenter prospective cohort study that began in October 2022 and will continue until December 2023. Data from 20 Polish surgical departments were collected. Overall 45 patients were reported over the initial 3 months; based on that group we performed a preliminary analysis.

Results

Mean operative time was 163 min. Patients were operated on by specialists in 93.3% of cases. Complications occurred in 15 (33.3%) patients. Wound infection was the most common complication (17.8%). In 3 (6.7%) cases anastomotic leakage was diagnosed, and in 2 of those cases reoperation was required. The overall mortality rate was 2.2%. The mean length of hospital stay was 10.1 days. Preoperative fasting was used in 53.3% of patients, and the mechanical bowel preparation rate was 75.6%. Only in 8.9% of cases was laparoscopic access used for stoma reversal, and only in 1 out of 45 cases was mesh used for incisional peristomal hernia prophylactics. The stoma site was closed by single sutures in 73.3%, and negative pressure assisted closure was performed in 6.7% of patients.

Conclusions

Colostomy liquidation is associated with significant morbidity and minor mortality in the Polish population. Standardized perioperative care should be established for stoma reversal surgery.

Indocyanine green fluorescence angiography in colorectal surgery: A retrospective case-control analysis in Mexico

INTRODUCTION AND AIMS

An anastomotic leak is one of the most dreaded complications in colorectal surgery because it increases postoperative morbidity and mortality. The aim of the present study was to identify whether indocyanine green fluorescence angiography (ICGFA) reduced the anastomotic dehiscence rate in colorectal surgery.

MATERIAL AND METHODS

A retrospective study on patients that underwent colorectal surgery with colonic resection or low anterior resection and primary anastomosis, within the time frame of January 2019 and September 2021, was conducted. The patients were divided into the case group, in which ICGFA was performed for the intraoperative evaluation of blood perfusion at the anastomosis site, and the control group, in which ICGFA was not utilized.

RESULTS

A total of 168 medical records were reviewed, resulting in 83 cases and 85 controls. Inadequate perfusion that required changing the surgical site of the anastomosis was identified in 4.8% of the case group (n = 4). A trend toward reducing the leak rate with ICGFA was identified (6% [n = 5] in the cases vs 7.1% in the controls [n = 6] [p = 0.999]). The patients that underwent anastomosis site change due to inadequate perfusion had a 0% leak rate.

CONCLUSIONS

ICGFA as a method to evaluate intraoperative blood perfusion showed a trend toward reducing the incidence of anastomotic leak in colorectal surgery.

Bowel preparation for elective colectomy in Crohn's disease: results from a global cohort study using the NSQIP database

AIM

The role of bowel preparation before colectomy in Crohn's disease patients remains controversial. This retrospective analysis of a prospective cohort study aimed to investigate the clinical outcomes associated with mechanical and antibiotic colon preparation in patients diagnosed with Crohn's disease undergoing elective colectomy.

METHOD

Data were collected from the American College of Surgeons National Surgical Quality Improvement Program participant user files from 2016 to 2021. A total of 6244 patients with Crohn's disease who underwent elective colectomy were included. The patients were categorized into two groups: those who received combined colon preparation (mechanical and antibiotic) and those who did not receive any form of bowel preparation. The primary outcomes assessed were the rate of anastomotic leak and the occurrence of deep organ infection. Secondary outcomes included all-cause short-term mortality, clinical-related morbidity, ostomy creation, unplanned reoperation, operative time, hospital length of stay and ileus.

RESULTS

Combined colon preparation was associated with significantly reduced risks of anastomotic leak (relative risk 0.73, 95% CI 0.56-0.95, P = 0.021) and deep organ infection (relative risk 0.68, 95% CI 0.56-0.83, P < 0.001). Additionally, patients who underwent colon preparation had lower rates of ostomy creation, shorter hospital stays and a decreased incidence of ileus. However, there was no significant difference in all-cause short-term mortality or the need for unplanned reoperation between the two groups.

CONCLUSION

This study shows that mechanical and antibiotic colon preparation may have clinical benefits for patients with Crohn's disease undergoing elective colectomy.

Indocyanine green fluorescence angiography could reduce the risk of anastomotic leakage in rectal cancer surgery: a systematic review and meta-analysis of randomized controlled trials

AIM

Several papers have shown that use of indocyanine green (ICG) decreases incidence of anastomotic leakage (AL) during colonic surgery, but no clear evidence has been found for rectal cancer surgery. Therefore, with this systematic review and meta-analysis of randomized controlled trials (RCTs) we aimed to assess if ICG could also reduce risk of AL in rectal cancer surgery.

METHOD

PubMed, Scopus, CINAHL and Cochrane databases were searched for RCTs assessing the effect of intraoperative ICG on the incidence of AL of the colorectal anastomosis. Pooled relative risk (RR) and pooled risk difference (RD) were obtained using models with random effects. Risk of bias was evaluated with the Rob2 tool and the quality of evidence was assessed using the GRADE Pro tool.

RESULTS

Four RCTs were included for analysis, with a total of 1510 patients (743 controls and 767 ICG patients). The rate of AL was 9% in the ICG group (69/767) and 13.9% (103/743) in the control group (p = 0.003, RR -0.5, 95% CI -0.827 to -0.172, heterogeneity test 0%, p = 0.460). The RD in terms of incidence of AL was significantly decreased by 4.51% (p = 0.031, 95% CI -0.086 to -0.004, heterogeneity test 28%, p = 0.182) when using ICG.

CONCLUSION

Our meta-analysis suggested that use of ICG during rectal cancer surgery could reduce the rate of AL.

The Impact of Mechanical Bowel Preparation and Oral Antibiotics in Colorectal Cancer Surgery (MECCA Study): A Prospective Randomized Clinical Trial

Background: Colorectal cancer surgery has been associated with surgical site infections (SSIs), leading to an increase in postoperative morbidity, length of stay and total cost. The aim of the present randomized study was to investigate the relationship between the preoperative administration of oral antibiotic therapy and SSI rate, as well as other postoperative outcomes in patients undergoing colorectal cancer surgery. Material and Methods: Patients who underwent colorectal cancer surgery in a university surgical department were included in the present study. Patients were randomized into two groups using the "block randomization" method. The intervention group received three doses of 400 mg rifaximin and one dose of 500 mg metronidazole per os, as well as mechanical bowel preparation the day before surgery. The control group underwent only mechanical bowel preparation the day before surgery. The study has been registered in ClinicalTrials.gov (NCT03563586). Results: Two hundred and five patients were finally included in the present study, 97 of whom received preoperative antibiotic therapy per os (intervention group). Patients of this group demonstrated a significantly lower SSI rate compared with patients who did not receive preoperative antibiotic therapy (7% vs. 16%, p = 0.049). However, preoperative antibiotic administration was not correlated with any other postoperative outcome (anastomotic leak, overall complications, readmissions, length of stay). Conclusions: Preoperative antibiotic therapy in combination with mechanical bowel preparation seemed to be correlated with a lower SSI rate after colorectal cancer surgery.

Validation of an endoscopic anastomotic grading score as an intraoperative method for assessing stapled rectal anastomoses

PURPOSE

Anastomotic leak is a dreaded complication of colorectal surgery. An endoscopic grading score of the perianastomotic mucosa has been previously developed at our institution (UCI) to assess colorectal anastomotic integrity. The objective of this study is to validate the UCI anastomotic score and determine its impact in anastomotic failure.

METHODS

As a follow-up study of the UCI grading score implementation during 2011 to 2014, patients undergoing stapled colorectal anastomoses after sigmoidectomy or proctectomy at a single institution from 2015 to 2018 were retrospectively reviewed. Patients were grouped into three tiers based on endoscopic appearance (grade 1, circumferentially normal mucosa; grade 2, ischemia/congestion < 30% of circumference; grade 3, ischemia/congestion > 30% of circumference).

RESULTS

On the basis of endoscopic mucosal evaluation, grade 1 anastomosis was observed in 299 patients (94%), grade 2 anastomosis in 14 patients (4.4%), and grade 3 anastomosis in 5 patients (1.6%). All grade 3 classifications were immediately and successfully revised intraoperatively with reclassification as a grade 1 anastomosis. The anastomotic leak rate of the follow-up study period from 2015 to 2018 was 6.4% which was lower compared to the anastomotic leak rate of 12.2% in the original study period from 2011 to 2014 (p = 0.07). Anastomotic leak rate for the entire patient series was 8.5%. A grade 2 anastomosis was associated with higher anastomotic leak rate compared to a grade 1 anastomosis (35.7% vs. 7.4%, p < 0.05). None of the five grade 3 anastomoses resulted in an anastomotic leak upon revision.

CONCLUSION

This study further validates the anastomotic grading score and suggests that its systematic implementation can result in a reduction in anastomotic leaks.

Rates and risk factors for anastomotic leak following blunt trauma-associated bucket handle intestinal injuries: a multicenter study

Objectives

The risk factors for anastomotic leak (AL) after resection and primary anastomosis for traumatic bucket handle injury (BHI) have not been previously defined. This multicenter study was conducted to address this knowledge gap.

Methods

This is a multicenter retrospective study on small intestine and colonic BHIs from blunt trauma between 2010 and 2021. Baseline patient characteristics, risk factors, presence of shock and transfusion, operative details, and clinical outcomes were compared using R.

Results

Data on 395 subjects were submitted by 12 trauma centers, of whom 33 (8.1%) patients developed AL. Baseline details were similar, except for a higher proportion of patients in the AL group who had medical comorbidities such as diabetes, hypertension, and obesity (60.6% vs. 37.3%, p=0.015). AL had higher rates of surgical site infections (13.4% vs. 5.3%, p=0.004) and organ space infections (65.2% vs. 11.7%, p<0.001), along with higher readmission and reoperation rates (48.4% vs. 9.1%, p<0.001, and 39.4% vs. 11.6%, p<0.001, respectively). There was no difference in intensive care unit length of stay or mortality (p>0.05). More patients with AL were discharged with an ostomy (69.7% vs. 7.3%, p<0.001), and the mean duration until ostomy reversal was 5.85±3 months (range 2-12.4 months). The risk of AL significantly increased when the initial operation was a damage control procedure, after adjusting for age, sex, injury severity, presence of one or more comorbidities, shock, transfusion of >6 units of packed red blood cells, and site of injury (adjusted RR=2.32 (1.13, 5.17)), none of which were independent risk factors in themselves.

Conclusion

Damage control surgery performed as the initial operation appears to double the risk of AL after intestinal BHI, even after controlling for other markers of injury severity.

Level of evidence

III.

Anastomotic leak in colorectal cancer surgery: Contribution of gut microbiota and prediction approaches

AIM

To monitor prospectively the occurrence of colorectal anastomotic leakage (CAL) in patients with colon cancer undergoing resectional surgery, characterizing the microbiota in both faeces and mucosal biopsies of anastomosis. In a second stage, we investigated the ability to predict CAL using machine learning models based on clinical data and microbiota composition.

METHOD

A total of 111 patients were included, from whom a faecal sample was obtained, as well as biopsy samples from proximal and distal sites in the healthy margins of the tumour piece. The microorganisms present in the samples were investigated using microbial culture and 16S rDNA massive sequencing. Collagenase and protease production was determined, as well as the presence of genes responsible for expressing enzymes with these activities. Machine learning analyses were developed using clinical and microbiological data.

RESULTS

The incidence of CAL was 9.0%, and CAL was associated with collagenase/protease-producing Enterococcus. Significant differences were found in the microbiota composition of proximal and distal biopsy samples, but not in faecal samples, among patients who developed CAL. Clinical predictors of CAL were 5-day C-reactive protein and heart disease, whereas 3-day C-reactive protein and diabetes were negative predictors.

CONCLUSION

Biopsy samples from surgical margins, rather than faecal samples, are the most appropriate samples for exploring the contribution of the intestinal microbiota to CAL. Enterococci are only enriched in the anastomosis after surgery, and their collagenases and proteases are involved in the degradation of the anastomotic scar.

Intraoperative Anastomotic Evaluation Methods: Rigid Proctoscopy Versus Flexible Endoscopy

INTRODUCTION

Rigid proctosigmoidoscopy (RP) and flexible sigmoidoscopy (FS) are two modalities commonly used for intraoperative evaluation of colorectal anastomoses. This study seeks to determine whether there is an association between the endoscopic modality used to evaluate colorectal anastomoses and the rate of anastomotic leak (AL), organ space infection, and overall infectious complication.

METHODS

The 2012-2018 American College of Surgeons National Surgical Quality Improvement Program database was queried for patients undergoing colorectal anastomoses. Anastomotic evaluation method (RP versus FS) was identified by Current Procedural Terminologycoding and used for group classification. Outcomes measured included AL, organ space infections, and overall infection. Multivariable logistic regression analysis for predicting AL was performed.

RESULTS

We identified 7100 patients who underwent a colorectal anastomosis with intraoperative endoscopic evaluation. RP was utilized in 3397 (47.8%) and FS in 3703 (52.2%) patients. RP was used more commonly in diverticulitis (44.5% versus 36.2%, P < 0.01), while FS was used more frequently in malignancy (47.5% versus 36.7%, P < 0.01). Anastomotic evaluation with FS was associated with lower rates of organ space infection (3.8% versus 4.8%, P = 0.025) and AL (2.9% versus 3.8%, P = 0.028) compared to RP. On multivariate logistic regression modeling, anastomotic evaluation with RP was associated with a higher risk of AL (odds ratio 1.403, 95% CI 1.028-1.916, P = 0.033) compared to FS.

CONCLUSIONS

Compared to FS, rigid proctosigmoidoscopic evaluation of a colorectal anastomosis was associated with an increased rate of AL and organ space infection.

Fluorescent ICG angiography in laparoscopic rectal resection - a randomized controlled trial. Preliminary report

Introduction

Anastomotic leakage is one of the most dangerous complications after rectal surgery. It can cause systemic complications, reduce the quality of life and worsen the results of oncological treatment. One of the causes of anastomotic leak is insufficient blood supply to the anastomosis. Intraoperative infrared angiography with indocyanine green (ICG) is expected to improve the assessment of intestinal perfusion and thus prevent anastomotic leakage.

Aim

To present the results of the use of ICG intraoperative angiography during rectal surgery in the prevention of anastomotic leakage.

Material and methods

The study included 76 patients undergoing rectal cancer surgery. Patients were randomized to 2 groups: Group I - 41 patients with ICG intraoperative angiography; and Group II - 35 patients without ICG imaging. Anastomotic leak, length of hospitalization, and complication rate were compared.

Results

Group I patients received intravenous ICG before the anastomosis. Average time of intestinal wall contrasting was 42 s (22-65 s). Average ICG procedure time was 4 min (3.2% of total time of surgery). Three (7.3%) patients after angiography revealed intestinal ischemia requiring widened resection. No anastomotic leak was found post-operatively, and no side effects were observed after administration of ICG. In group II, 3 (8.6%) anastomotic leakages were diagnosed, 2 of which required reoperation.

Conclusions

Intraoperative angiography with ICG in near-infrared light is a safe and effective method of assessing intestinal perfusion. ICG angiography may change the surgical plan and reduce the risk of anastomotic leakage. It is necessary to continue the study until the assumed number of patients is reached.

Three-row versus two-row circular staplers for left-sided colorectal anastomosis: a propensity score-matched analysis of the iCral 2 and 3 prospective cohorts

BACKGROUND

Since most anastomoses after left-sided colorectal resections are performed with a circular stapler, any technological change in stapling devices may influence the incidence of anastomotic adverse events. The aim of the present study was to analyze the effect of a three-row circular stapler on anastomotic leakage and related morbidity after left-sided colorectal resections.

MATERIALS AND METHODS

A circular stapled anastomosis was performed in 4255 (50.9%) out of 8359 patients enrolled in two prospective multicenter studies in Italy, and, after exclusion criteria to reduce heterogeneity, 2799 (65.8%) cases were retrospectively analyzed through a 1:1 propensity score-matching model including 20 covariates relative to patient characteristics, to surgery and to perioperative management. Two well-balanced groups of 425 patients each were obtained: group (A) - true population of interest, anastomosis performed with a three-row circular stapler; group (B) - control population, anastomosis performed with a two-row circular stapler. The target of inferences was the average treatment effect in the treated (ATT). The primary endpoints were overall and major anastomotic leakage and overall anastomotic bleeding; the secondary endpoints were overall and major morbidity and mortality rates. The results of multiple logistic regression analyses for the outcomes, including the 20 covariates selected for matching, were presented as odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

Group A versus group B showed a significantly lower risk of overall anastomotic leakage (2.1 vs. 6.1%; OR 0.33; 95% CI 0.15-0.73; P =0.006), major anastomotic leakage (2.1 vs. 5.2%; OR 0.39; 95% CI 0.17-0.87; P =0.022), and major morbidity (3.5 vs. 6.6% events; OR 0.47; 95% CI 0.24-0.91; P =0.026).

CONCLUSION

The use of three-row circular staplers independently reduced the risk of anastomotic leakage and related morbidity after left-sided colorectal resection. Twenty-five patients were required to avoid one leakage.

Reducing anastomotic leakage in TaTME by mucosal coverage of staple lines: a pilot study with preliminary results

PURPOSE

We have performed a single stapled anastomosis with double purse-string sutures as a Trans anal Total Mesorectal Excision (TaTME) reconstruction for low rectal cancer. We report an attempt to control local infection and reduce anastomotic leakage (AL) at this anastomotic site.

PATIENTS AND METHODS

Fifty-one patients who underwent TaTME for low rectal cancer from April 2021 to October 2022 were included. TaTME was performed by two teams, and reconstruction was performed by anastomosis with a single stapling technique (SST). After the anastomosis was thoroughly cleaned, Z sutures were placed parallel to the staple line to suture the mucosa on the oral and anal side of the staple line and to cover the staple line circumferentially. Data on operative time, Distal Margin (DM), recurrence and postoperative complications including AL were prospectively collected.

RESULTS

The mean age of patients was 67 years. There were 36 males and 15 females. The overall mean operative time was 283.1 min, and the mean Distal Margin was 2.2 cm. Postoperative complications were observed in 5.9% of the patients, but no AL was observed, nor any serious complications with Clavien-Dindo ≥ 3 grade. Of the 49 cases excluding Stage 4, postoperative recurrence was observed in 2 cases (4.9%).

CONCLUSION

In patients with lower rectal cancer who underwent TaTME, additional mucosal coverage of the anastomotic staple line by transanal manipulation after reconstruction may be associated with a reduction in the incidence of postoperative AL. Further studies including late anastomotic complications are needed.

Integration of prolapsing technique and one-stitch method of ileostomy during laparoscopic low anterior resection for rectal cancer: a retrospective study

Background

Prolapsing technique is a type of natural orifice specimen extraction surgery that can overcome the difficulty of precise transection of the distal rectum and subsequent anastomosis in a narrow pelvic space. Currently, protective ileostomy is widely utilized in low anterior resection for low rectal cancer, which may reduce the severe consequences caused by anastomotic leakage. The study aimed to combine the prolapsing technique with a one-stitch method of ileostomy and evaluate the surgical outcomes.

Methods

A retrospective analysis was conducted on patients with low rectal cancer who underwent protective loop ileostomy in laparoscopic low anterior resection between January 2019 and December 2022. The patients were divided into prolapsing technique combined with the one-stitch method of ileostomy (PO) group and traditional method (TM) group, and the intraoperative details and early postoperative outcomes of the two groups were measured.

Results

A total of 70 patients met the inclusion criteria, including 30 patients who underwent PO and 40 patients who underwent the traditional procedure. The PO group had a shorter total operative time than the TM group (197.8 ± 43.4 vs. 218.3 ± 40.6 min, P = 0.047). The time of intestine function recovery in the PO group was shorter than that in the TM group (24.6 ± 3.8 vs. 32.7 ± 5.4 h, P < 0.001). Compared with the TM group, the average VAS score was significantly lower in the PO group (P < 0.001). The incidence of anastomotic leakage in the PO group was significantly lower than that in the TM group (P = 0.034). The operative time of loop ileostomy was 2.0 ± 0.6 min in the PO group, which was significantly less than 15.1 ± 2.9 min in the TM group. Skin irritation was observed in 2 patients in the PO group and 10 patients in the TM group; therefore, there was a significant difference (P = 0.044).

Conclusion

This method is safe and feasible, which reduces the technical difficulty and achieves rapid postoperative recovery with few complications.

The role of preoperative mechanical bowel preparation and oral antibiotics in prevention of anastomotic leakage following restorative resection for primary rectal cancer - a systematic review and meta-analysis

PURPOSE

Anastomotic leakage after colorectal cancer resection is a feared postoperative complication seen among up till 10-20% of patients, with a higher risk following rectal resection than colon resection. Recent studies suggest that the combined use of preoperative mechanical bowel preparation and oral antibiotics may have a preventive effect on anastomotic leakage. This systematic review aims to explore the association between preoperative mechanical bowel preparation combined with oral antibiotics and the risk of anastomotic leakage following restorative resection for primary rectal cancer.

METHODS

Three databases were systematically searched in February 2022. Studies reporting anastomotic leakage rate in patients, who received mechanical bowel preparation and oral antibiotics before elective restorative resection for primary rectal cancer, were included. A meta-analysis was conducted based on the risk ratios of anastomotic leakage.

RESULTS

Among 839 studies, 5 studies met the eligibility criteria. The median number of patients were 6111 (80-29,739). The combination of preoperative mechanical bowel preparation and oral antibiotics was associated with a decreased risk of anastomotic leakage (risk ratio = 0.52 (95% confidence interval 0.39-0.69), p-value < 0.001). Limitations included a low number of studies, small sample sizes and the studies being rather heterogenous.

CONCLUSION

This systematic review and meta-analysis found that the use of mechanical bowel preparation and oral antibiotics is associated with a decreased risk of anastomotic leakage among patients undergoing restorative resection for primary rectal cancer. The limitations of the review should be taken into consideration when interpreting the results.

Comparison of Midline and Off-midline specimen extraction following laparoscopic left-sided colorectal resections: A systematic review and meta-analysis

Aims

This study aims to evaluate comparative outcomes following midline versus off-midline specimen extractions following laparoscopic left-sided colorectal resections.

Methods

A systematic search of electronic information sources was conducted. Studies comparing 'midline' versus 'off midline' specimen extraction following laparoscopic left-sided colorectal resections performed for malignancies were included. The rate of incisional hernia formation, surgical site infection (SSI), total operative time and blood loss, anastomotic leak (AL) and length of hospital stay (LOS) was the evaluated outcome parameters.

Results

Five comparative observational studies reporting a total of 1187 patients comparing midline (n = 701) and off-midline (n = 486) approaches for specimen extraction were identified. Specimen extraction performed through an off-midline incision was not associated with a significantly reduced rate of SSI (odds ratio [OR]: 0.71; P = 0.68), the occurrence of AL (OR: 0.76; P = 0.66) and future development of incisional hernias (OR: 0.65; P = 0.64) compared to the conventional midline approach. No statistically significant difference was observed in total operative time (mean difference [MD]: 0.13; P = 0.99), intraoperative blood loss (MD: 2.31; P = 0.91) and LOS (MD: 0.78; P = 0.18) between the two groups.

Conclusions

Off-midline specimen extraction following minimally invasive left-sided colorectal cancer surgery is associated with similar rates of SSI and incisional hernia formation compared to the vertical midline incision. Furthermore, there were no statistically significant differences observed between the two groups for evaluated outcomes such as total operative time, intra-operative blood loss, AL rate and LOS. As such, we did not find any advantage of one approach over the other. Future high-quality well-designed trials are required to make robust conclusions.

Intraluminal Anastomotic Assessment Using Indocyanine Green Near-Infrared Imaging for Left-Sided Colonic and Rectal Resections: a Systematic Review

BACKGROUND

Indocyanine green fluorescence angiography (ICG-FA) has been used in colorectal surgery to assess anastomotic perfusion and reduce the risks of anastomotic leaks. The main objective of this paper is to review the data on the transanal application of ICG-FA for the intraluminal assessment of colorectal anastomosis.

METHODS

A literature search was conducted for articles published between 2011 and 2021 using PubMed and Cochrane databases, related to the application of ICG for the intraluminal assessment of colorectal anastomosis. Original scientific manuscripts, review articles, meta-analyses, and case reports were considered eligible.

RESULTS

A total of 305 studies have been identified. After abstract screening for duplicates, 285 articles remained. Of those, 271 were not related to the topic of interest, 4 were written in a language other than English, and 4 had incomplete data. Six articles remained for the final analysis. The intraluminal assessment of colorectal anastomosis with ICG-FA is feasible, safe, and may reduce the incidence of leaks.

CONCLUSION

The intraluminal assessment of anastomotic perfusion via ICG-FA may be a promising novel application of ICG technology. More data is needed to support this application further to reduce leak rates after colorectal surgery, and future randomized clinical trials are awaited.

Early and late anastomotic leak after colorectal surgery: A systematic review of the literature

The aim of this study was to review and to assess the quality of the scientific articles regarding early and late anastomotic leak (AL) after colorectal surgery and their risk factors. An electronic systematic search for articles on Colorectal Surgery, AL and its timing was undertaken using the MEDLINE database via PubMed, Cochrane and Embase. The selected articles were thoroughly reviewed and assessed for methodological quality using a validated methodology quality score (MINCIR score). This review was registered in the PROSPERO registry under ID: CRD42022303012. 9 articles were finally reviewed in relation to the topic of early and late anastomotic leak. There is a lack of consensus regarding the exact cut-off in time to define early and late anastomotic leak, but it is clear that they are two differentiated entities. The first, occurring in relation to technical factors; whereas the latter, is related to impaired healing.

The Predictive Value of PCT and Other Infection Indicators in Postoperative Infection of Epithelial Ovarian Cancer

Purpose

To study the early predictive value of WBC, CRP and PCT on infectious complications after epithelial ovarian cancer surgery, draw ROC curves, and construct a nomogram prediction model.

Patients and Methods

The clinical data of patients with epithelial ovarian cancer in Shengjing Hospital from August 2019 to August 2022 were included. The levels of WBC, CRP and PCT were statistically analyzed on the first, third and fifth days after surgery, and the ROC was plotted. Multivariate logistic regression analysis determined independent influencing factors, individualized nomogram model for predicting the occurrence of postoperative infectious complications was constructed, and the correction curve was used for verification.

Results

A total of 116 patients were enrolled. The postoperative test levels of WBC, CRP and PCT were compared between two groups, and the differences on POD3 and POD5 were statistically significant. The ROC area on POD5 was 0.739, 0.838 and 0.804, respectively, better than that on POD3. Among them, CRP has the greatest value; The predicted value of the combined test of WBC, CRP and PCT on POD5 was greater than that of a single index on POD5. The nomogram model on POD5 was constructed, and the ROC analysis showed that it had a good degree of differentiation.

Conclusion

WBC, CRP and PCT can effectively predict the occurrence of postoperative infectious complications, among which CRP alone has the greatest diagnostic value on POD5, and the combined test value of the three indicators is higher than that of a single index. The nomogram model constructed by the combined indicators on POD5 can assess the risk individually.

Assessment of Anastomotic Viability With Spectroscopic Real-time Oxygen Saturation Measurement in a Porcine Study

OBJECTIVE

Anastomotic leakage (AL) is a severe complication following intestinal procedures. Intra.Ox™ by ViOptix Inc (Newark, CA, USA) is a novel, FDA-approved spectroscopic device which enables real-time measurement of mixed tissue oxygen saturation (StO₂). Using a porcine model, this study explores the correlation between StO₂ measurements and AL formation as well as investigates the applicability of Intra.Ox™ in the clinical setting.

METHODS

Eleven female swine were divided into 3 groups to explore AL formation in different ischemic conditions. Group 1: 100% mesenteric-vascular ligation, n = 3; Group 2: 50% ligation, n = 5; Group 3: No mesenteric ligation, n = 3. StO₂ at the anastomotic line was measured before and after vessel ligation and anastomosis. Measurements were taken at 6 distinct locations along afferent and efferent loops. AL was evaluated on postoperative day 5 by re-laparotomy.

RESULTS

AL rate was 100%, 60% and 0% in groups 1, 2 and 3, respectively. Post-anastomotic StO₂ in group 1 (22.9 ± 18.5%) and 2 (39.2 ± 20.1%) were significantly lower than in group 3 (53.1 ± 8.3%, p<.0001). Post-anastomotic StO₂ readings ≤40% indicated AL potential with 100% sensitivity,+ 80% specificity, positive predictive value of 85.7% and negative predictive value of 100%.

CONCLUSION

This study demonstrates the value of Intra.Ox™ in assessing local perfusion and indicate the association between low StO₂ and AL by providing accurate, real-time, noninvasive tissue oxygenation measurements at anastomotic sites. Further studies are required to investigate the clinical application of this novel device in intestinal surgery.

Role of transanal drainage tubes in preventing anastomotic leakage after low anterior resection: a meta-analysis of randomized controlled trials

BACKGROUND

The transanal drainage tube (TDT) is thought to reduce the incidence of anastomotic leakage (AL) in patients with low anterior resection (LAR). However, results from different clinical trials are inconsistent, although nearly all meta-analyses agree on the efficacy. In contrast to results of many previous studies, 2 recent independent randomized controlled trials (RCTs) suggest that the use of TDT does not prevent AL. We performed a meta-analysis including only RCTs to compare patients with TDTs vs. those without TDTs in terms of AL rate.

METHODS

A systematic literature search was performed in the PubMed, Embase, Cochrane Library databases, Clinicaltrials.gov and WHO/ICTRP from inception until February 14, 2022. RCTs that evaluated the role of TDTs in AL prevention in patients who underwent LAR for rectal cancer were included. A meta-analysis was performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. Data were extracted by two authors independently, and random-effects models were implemented. The main outcome was AL, and the secondary outcome was the grade of AL.

RESULTS

Three RCTs were included involving a total of 1115 participants (559 patients in the TDT group and 556 in the non-TDT group). No significant difference in the AL rate was detected (RR = 0.69, 95% confidence interval (CI) 0.42-1.15, p = 0.15, I² = 21%, very low certainty evidence). The incidence of grade C AL was possibly lower in the TDT group (RR = 0.33, 95% CI 0.11-1.01, p = 0.05, very low certainty evidence), while the rate of grade B AL was similar between the two groups (RR = 1.17, 95% CI 0.66-2.08, p = 0.59, very low certainty evidence).

CONCLUSIONS

The present meta-analysis suggests that TDTs are not effective in reducing the overall incidence of AL, but possibly have a potential benefit in reducing the occurrence of grade C AL in patients with LAR. Based on the current limited data and existing heterogeneity, the inclusion of larger populations and the identification of more uniform indications for TDT need to be addressed in future studies.

Mesenteric Vascular Evaluation with Pre-operative Multidetector Computed Tomographic Angiography and Intraoperative Indocyanine Green Angiography to Reduce Anastomotic Leaks after Minimally Invasive Surgery for Colorectal Cancer

Background

The aim of this prospective study was to determine the effect of mesenteric vascular evaluation using pre-operative multidetector computed tomography angiography (MDCTA) and intraoperative indocyanine green (ICG) angiography on reducing the anastomotic leak rate of colorectal cancer patients undergoing minimally invasive resection.

Methods

Twenty-seven consecutive patients with colorectal cancer were studied, 18 males and 9 females, average age 69.1 ± 3.9 years. All patients underwent pre-operative mesenteric vascular evaluation using MDCTA with three-dimensional (3D) reconstruction and intraoperative evaluation of perfusion using ICG angiography. Twelve patients underwent laparoscopic resection (Olympus Visera Elite II OTV-S200) and 15 patients underwent robotic resection (DaVinci Si). Colorectal resection lines and anastomoses were guided by intraoperative ICG perfusion. Postoperative anastomotic leaks were assessed.

Results

Pre-operative MDCTA 3D reconstructions defined the left colic and sigmoid artery anatomy and guided operative planning. The intraoperative ICG angiography resulted in a change of the planned lines of resection in seven patients (26%). The rate of postoperative anastomotic leaks in this study was 0% (0/27), compared to a leak rate of 6.8% at our institution in the preceding two years.

Conclusion

Pre-operative evaluation of mesenteric vascular anatomy using MDCTA with 3D reconstruction and intraoperative evaluation of perfusion using ICG angiography were found to be technically feasible and safe. An appropriately designed study should be undertaken to prove whether it was truly effective at reducing the postoperative anastomotic leak rate in colorectal cancer patients undergoing minimally invasive resection at our institution.

VIVOSTAT ® SYSTEM AS A METHOD OF PREVENTING ANASTOMOTIC LEAKAGE FOLLOWING LOW ANTERIOR RECTAL RESECTION: CLINICAL CASE

Background: According to current literature, anastomosis leakage holds a leading position among all complications of colorectal surgery. A particular area of prevention of this complication in colorectal oncology is the research of the possibilities of using biological adhesive compounds as a universal biological and mechanical barrier to the spread of intraluminal microflora and tumor cells.

Clinical case: A 65-year-old patient (female) was hospitalized with a diagnosis of rectal cancer cT3cN1cM0 (stage III) after neoadjuvant chemoradiotherapy. Surgical treatment was performed: the laparoscopic low anterior resection of the rectum with expanded lymphodissection, protective loop ileostomy. The anastomosis was formed at a height of 4 cm from the anus. Intraoperatively, the anastomosis line was strengthened using the Vivostat R system product. The technology of on-site preparation and application of the compound is described in the paper.. The postoperative period passed without complications.

Conclusion: Due to the possible economic, oncological and postoperative advantages, the use of modern fibrin adhesive compositions is quite promising for introduction into surgical practice. It is required to conduct research aimed at studying the effectiveness of this method of preventing the leakage of colorectal anastomoses.

Application of Transurethral Prostate Resection Instrumentation for Treating Low Rectal Anastomotic Leakage: A Pilot Study

Purpose

To determine an accurate method of inspecting low anastomotic leakages and application of transurethral prostate resection instrumentation for treating low rectal anastomotic leakage.

Patients and Methods

Clinical data of eight patients treated for anastomotic leakage after rectal cancer surgery at Zhangye People’s Hospital (affiliated to Hexi University), from August 2019 to November 2021, were retrospectively analyzed. Transanal prostate resection instrumentation was used to assess the leakage and surrounding conditions. Using prostate resection instrumentation, the presacral and perirectal residual cavities were washed and removed, and indwelling suprapubic presacral, transanal presacral, and rectal drainage tubes were placed. Continuous presacral saline irrigation and drainage and open negative-pressure suction in the rectal cavity were performed until the patients’ fistula healed.

Results

Of the eight patients with anastomotic leakages, one had grade B and seven had grade C International Study Group of Rectal Cancer anastomotic leakage classifications following Dixon operation. Transanal prostate resection instrumentation showed that the leakage of the one patient with grade B was less than a third of the circumference of the anastomosis. Among the seven patients with grade C, one leakage was less than a third of the anastomotic circumference. One patient had complete separation of the anastomosis and one distal colon necrosis, which necessitated immediate descending colostomy. Conservative treatment was successful in six patients; the conservative overall cure rate was 75%, and the median healing time was 43 (21–68) days.

Conclusion

Transanal examination of rectal anastomotic leakage using prostate resection instrumentation is comprehensive, easy to perform, provides clear visualization, accurately guides catheter placement, and can be combined with continuous open negative-pressure drainage, which is a safe, convenient, and effective method for treating low rectal leakage.

The Role of Indocyanine Green Fluorescence in Rectal Cancer Robotic Surgery: A Narrative Review

Background: In rectal cancer surgery, anastomotic leakage (AL) remains the most feared complication, with a frequency of up to 30% in non-high-volume centers. The preservation of proper vascularization is a key factor for successful anastomosis. The use of fluorescence with indocyanine green (ICG) as an intraoperative method to verify optimal perfusion is becoming an interesting tool in rectal surgery. Today, robotic surgery, together with the use of the intraoperative evaluation of the perfusion with ICG, could be a real strategy to deal with AL, allowing for a more delicate and less traumatic surgical technique. This strategy may allow for an extremely accurate surgery, and for optimal control of the proper vascularization of the rectum. Methods: The purpose of this descriptive review is to analyze the impact of fluorescence and robotic surgery on short-term surgical outcomes for rectal cancer. Results: We performed a systematic literature search using the PubMed, Embase and Cochrane library databases. The primary endpoints were to evaluate the application of ICG fluorescence in robotic rectal surgery and the rate of anastomotic leakage when using these technological implementations. The secondary endpoints were to evaluate the dosage of ICG and the timing of application by different surgeons. Conclusions: ICG fluorescence is an inexpensive and quick method to assess bowel perfusion, providing immediate feedback to the surgeon, even if its role has not been proven. A quantitative system must be systematically introduced to minimize the subjectiveness of the visualized image.

Fluorescence angiography likely protects against anastomotic leak in colorectal surgery: a systematic review and meta-analysis of randomised controlled trials

Objective

Observational studies have shown that fluorescence angiography (FA) decreases the incidence of anastomotic leak (AL) in colorectal surgery, but high-quality pooled evidence was lacking. Therefore, we aimed at confirming this preliminary finding using a systematic review and meta-analysis of randomised controlled trials (RCTs) in the field.

Methods

MEDLINE, Embase and CENTRAL were searched for RCTs assessing the effect of intra-operative FA versus standard assessment of bowel perfusion on the incidence of AL of colorectal anastomosis. The systematic review complied with the PRISMA 2020 and AMSTAR2 recommendations and was registered in PROSPERO. Pooled relative risk (RR) and pooled risk difference (RD) were obtained using models with random effects. Heterogeneity was assessed using the Q-test and quantified using the I² value. Certainty of evidence was assessed using the GRADE Pro tool.

Results

One hundred and eleven articles were screened, 108 were excluded and three were kept for inclusion. The three included RCTs compared assessment of the perfusion of the bowel during creation of a colorectal anastomosis using FA versus standard practice. In meta-analysis, FA was significantly protective against AL (3 RCTs, 964 patients, RR: 0.67, 95% CI: 0.46 to 0.99, I²: 0%, p = 0.04). The RD of AL was non-significantly decreased by 4 percentage points (95%CI: − 0.08 to 0, I²: 8%, p = 0.06) when using FA. Certainty of evidence was considered as moderate.

Conclusion

The effect of FA on prevention of AL in colorectal surgery exists but is potentially of small magnitude. Considering the potential magnitude of effect of FA, we advise that future RCTs have an adequate sample size, include a cost-benefit analysis of the technique and better define the subpopulation who could benefit from FA.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-022-09255-1.

The Microbiota and the Relationship with Colorectal Cancer: Surgical Complications—A Review

Colorectal cancer (CRC) is one of the most common cancers and represents a major global health burden. While genetics are implicated in a portion of CRC patients, most cases are sporadic. A new possibility of tumor initiation and promotion might be microbiome composition. It was recently shown that bacteria from the gut microbiome might be used as biomarkers for CRC detection, especially Fusobacterium nucleatum, Peptostreoptococcus stomatis, Parvimonas mica, Solobacterium moorei, and Peptostreptococcus anaerobius. Conversely, the healthy gut microbiome is mostly colonized by Bacterioides (Bacterioides fragilis, vulgatus, uniformis), Firmicutes (Clostridium spp., Ruminococcus faecis, Enterococcus faecium), and Actinobacteria (Bifidobacterium bifidum). Some strains of gut bacteria favor tumor promotion through DNA and RNA damage (directly or through interaction with other known food carcinogens) and through local immune inhibition. It is possible that bacteria (e.g., Bacillus polyfermenticus, Alistipes shahii, Lactobacillus casei) exist with protective functions against tumor promotion. Despite current advances in colorectal cancer treatment, especially in the medical oncology and radiotherapy domains, surgery remains the mainstay of curative treatment for colorectal cancer patients, even in the oligometastatic setting. Surgical complications like anastomotic leakage, excessive blood loss, abscess, and abdominal sepsis can reduce 1-year and 5-year overall survival and increase the recurrence rates for these patients; therefore, we reviewed currently published data focusing on the relationship between gut microbiota and postoperative complications for colorectal cancer patients.

Prophylactic endoluminal vacuum therapy after major gastrointestinal surgery: a systematic review

In the last decade, endoluminal vacuum therapy (eVAC) has emerged as an effective treatment for anastomotic leak (AL); however, little is known regarding its prophylactic use. In this systematic review we evaluated overall outcomes in patients undergoing major gastrointestinal surgery and treated with prophylactic eVAC. A systematic review of English articles on four electronic databases was performed according to the PRISMA statement up until January 2022. References of selected articles were manually screened to identify relevant missing papers. Primary endpoints were AL and mortality rates estimates. Secondary endpoints included analysis of eVAC-associated morbidity, treatment duration, long-term complications, and general indications for the eVAC management in the perioperative period. A total of 11 studies (5 case reports, 5 retrospective case series and a retrospective, case-control study) were included in the analysis. AL ranged from 0 to 25%. No major eVAC-associated complications were observed, except for sponge dislocation or obstruction. Overall mortality ranged between 0 and 12.5%; however, these fatalities were neither related to the use of eVAC, nor to AL-associated complications. The most frequent long-term complication was anastomotic stenosis responsive to endoscopic dilatation in most cases. The operating negative pressure ranged from -25 to -125 mmHg among different papers. In all studies but two, prophylactic eVAC was applied to anastomoses at high risk of dehiscence based on the subjective evaluation of the leading surgeon. In conclusion, prophylactic eVAC is safe and it could lead to potential benefit for prevention of AL, especially in high-risk anastomoses.

Detection of Anastomotic Leakage Following Elective Colonic Surgery: Results of the Prospective Biomarkers and Anastomotic Leakage (BALL) Study

BACKGROUND

Anastomotic leakage (AL) is an infrequent but life-threatening surgical complication following colorectal surgery. Early diagnosis remains clinically difficult but is a necessity to reduce associated morbidity and mortality. Clinical review and radiological modalities for the diagnosis of leakage remain non-specific and often only detect AL once it is well developed. Inflammatory biomarkers however have shown promise in early pre-clinical detection of leakage following colorectal surgery.

METHODS

A multi-center, prospective observational study was conducted across four public hospitals in Auckland and Christchurch, New Zealand. Consecutive adults undergoing elective colectomy were initially recruited over a 3-y period. Perioperative blood samples were collected to measure interleukin (IL)-6, IL-1β, tumor necrosis factor α, IL-10, C-reactive protein (CRP), leukocyte and neutrophil counts. Statistical analysis was performed to compare patients with an uncomplicated recovery with patients with AL.

RESULTS

Sixteen patients developed AL (5.7%), diagnosed at a median post-operative (POD) day 7. CRP and IL-6 were consistently elevated in the early post-operative period in patients with AL, and had the best diagnostic accuracy on POD 3 (area under the curve 0.70; P = 0.02) and POD 1 (area under the curve 0.69; P = 0.02), respectively. IL-10, once adjusted for body mass index and surgical approach, was the sole biomarker significantly elevated in patients with AL on POD 4.

CONCLUSIONS

Early post-operative elevations of CRP and IL-6 provide utility for early detection of AL after elective colectomy. Application of these inflammatory biomarkers and their combinations in daily practice warrants further investigation.

Associations between matrix metalloproteinase, tissue inhibitor of metalloproteinase and collagen expression levels in the adjacent rectal tissue of colorectal carcinoma patients

As the commonest type of cancer in Europe and the third most common type of cancer worldwide, colorectal carcinoma (CRC) poses a challenge for numerous scientific studies. At present, the cause of this disease is remains to be elucidated, but early diagnosis is only one solution to prevent serious health complications. As a structural scaffold, the extracellular matrix (ECM) is in direct contact with tumour cells and significantly interferes with tumour progression. During the process of tumorigenesis, the ECM undergoes structural changes in which collagens serve an important role. Their life cycle is regulated by proteolytic enzymes called matrix metalloproteinases (MMPs), which are controlled by tissue inhibitors of metalloproteinases (TIMPs). The present study analysed the gene expression of MMPs (MMP1-2-8-10-13), TIMPs (TIMP1-2-4) and collagens (COL1A1 and COL3A1) and the correlation with biochemical parameters in the adjacent rectal tissue (ART) of patients with CRC. The patients who underwent standard neoadjuvant pre-therapy showed increased concentrations of collagen in the normal ART. The mRNA levels of COL3A1, TIMP1 and TIMP2 were significantly higher in the ART of CRC patients (with or without pre-therapy) when compared with the control group. This finding suggested that TIMPs served an important role in the regulation of MMPs and in the modification of collagen content in the ECM. Despite the small data set, the present study provided insights into the transcriptomic relationships between the individual genes that are an integral part of the ECM.

Changes in the gut bacterial communities in colon cancer surgery patients: an observational study

Background

Colon surgery has been shown to modulate the intestinal microbiota. Our objective was to characterize these changes using state-of-the-art next generation sequencing techniques.

Methods

We performed a single-centre prospective observational cohort study to evaluate the changes in the gut microbiota, i.e., taxon distribution, before and after elective oncologic colon surgery in adult patients with different antimicrobial prophylaxis regimens (standard prophylaxis with cefuroxime/metronidazole versus carbapenems for extended-spectrum beta-lactamase-producing Enterobacterales [ESBL-E] carriers). We obtained rectal samples on the day of surgery, intraoperative luminal samples, and rectal or stoma samples 3 days after surgery. We performed metataxonomic analysis based on sequencing of the bacterial 16S rRNA gene marker. Similarities and differences between bacterial communities were assessed using Bray–Curtis similarity, visualised using principal coordinates analysis and statistically tested by PERMANOVA. Comparison of taxa relative abundance was performed using ANCOM.

Results

We included 27 patients between March 27, 2019 and September 17, 2019. The median age was 63.6 years (IQR 56.4–76.3) and 44% were females. Most (81%) patients received standard perioperative prophylaxis as they were not ESBL carriers. There was no significant association between ESBL carriage and differences in gut microbiome. We observed large and significant increases in the genus Enterococcus between the preoperative/intraoperative samples and the postoperative sample, mainly driven by Enterococcus faecalis. There were significant differences in the postoperative microbiome between patients who received standard prophylaxis and carbapenems, specifically in the family Erysipelotrichaceae.

Conclusion

This hypothesis-generating study showed rapid changes in the rectal microbiota following colon cancer surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13099-021-00477-7.

Human Colonic Microbiota and Short-Term Postoperative Outcomes in Colorectal Cancer Patients: A Pilot Study

Despite the advances in surgical techniques and perioperative care, the complication rates after colorectal cancer surgery have remained stable. Recently, it has been suggested that colon microbiota may be implicated in several pathways that can lead to impaired colonic homeostasis and, thereby, to the development of complications after colorectal surgery. The aim of this study was to evaluate the potential impact of colonic dysbiosis on postoperative course. This prospective human clinical study recruited patients operated on for left colon, sigmoid colon or rectal cancer. Colon mucosa and fecal samples were collected to study mucosa associated microbiota (MAM) and luminal microbiota (LM), accordingly. Preliminary analysis for the first 25 consecutive patients with V3–V4 16S rRNA metagenomic analysis was performed. Bacterial composition and abundance in patients who developed postoperative complications over a 90-day follow-up period were compared to those without postoperative complications. Abundance and distribution of genera in MAM differed significantly when compared to LM with a significant impact on neoadjuvant therapy on bacterial composition. Preliminary analysis revealed no statistically significant differences in LM nor in MAM composition when individuals with and without postoperative surgical complications were compared. In cases of postoperative complications, LM and MAM showed significantly decreased diversity. Composition of the colonic microbiota is altered by neoadjuvant therapy. Results on the impact of colonic dysbiosis on postoperative complications are pending the end of the present study, with 50 patients enrolled.

Oral and Parenteral vs. Parenteral Antibiotic Prophylaxis for Patients Undergoing Laparoscopic Colorectal Resection: An Intervention Review with Meta-Analysis

This study aims to systematically assess the efficacy of parenteral and oral antibiotic prophylaxis compared to parenteral-only prophylaxis for the prevention of surgical site infection (SSI) in patients undergoing laparoscopic surgery for colorectal cancer resection. Published and unpublished randomized clinical trials comparing the use of oral and parenteral prophylactic antibiotics vs. parenteral-only antibiotics in patients undergoing laparoscopic colorectal surgery were collected searching electronic databases (MEDLINE, CENTRAL, EMBASE, SCIENCE CITATION INDEX EXPANDED) without limits of date, language, or any other search filter. The outcomes included SSIs and other infectious and noninfectious postoperative complications. Risk of bias was assessed using the Cochrane revised tool for assessing risk of bias in randomized trials (RoB 2). A total of six studies involving 2252 patients were finally included, with 1126 cases in the oral and parenteral group and 1126 cases in the parenteral-only group. Meta-analysis results showed a statistically significant reduction of SSIs (OR 0.54, 95% CI 0.40 to 0.72; p < 0.0001) and anastomotic leakage (OR 0.55, 95% CI 0.33 to 0.91; p = 0.02) in the group of patients receiving oral antibiotics in addition to intravenous (IV) antibiotics compared to IV alone. Our meta-analysis shows that a combination of oral antibiotics and intravenous antibiotics significantly lowers the incidence of SSI compared with intravenous antibiotics alone.

Intracorporeal versus Extracorporeal Anastomosis for Laparoscopic Right Hemicolectomy: Short-Term Outcomes

Laparoscopic right hemicolectomy represents an effective therapeutic approach for right colon cancer (RCC). The primary aim of this study was to evaluate bowel function recovery, length of hospital stay, operative time, and the number of general and anastomosis-related postoperative complications from intracorporeal anastomosis (ICA) vs. extracorporeal anastomosis (ECA); the secondary outcome was the number of lymph nodes retrieved. This observational study was conducted on 108 patients who underwent right hemicolectomy for RCC; after surgical resection, 64 patients underwent ICA and 44 underwent ECA. The operative time was slightly longer in the ICA group than in the ECA group, even though the difference was not significant (199.31 ± 48.90 min vs. 183.64 ± 35.80 min; p = 0.109). The length of hospital stay (7.53 ± 1.91 days vs. 8.77 ± 3.66 days; p = 0.036) and bowel function recovery (2.21 ± 1.01 days vs. 3.45 ± 1.82 days; p < 0.0001) were significantly lower in the ICA group. There were no significant differences in postoperative complications (12% in ICA group vs. 9% in ECA group), wound infection (6% in ICA group vs. 7% in ECA group), or anastomotic leakage (6% in ICA group vs. 9% in ECA group). We did not observe a significant difference between the two groups in the number of lymph nodes collected (19.46 ± 7.06 in ICA group vs. 22.68 ± 8.79 in ECA group; p = 0.086). ICA following laparoscopic right hemicolectomy, compared to ECA, could lead to a significant improvement in bowel function recovery and a reduction in the length of hospital stay in RCC patients.

Current Insights: The Impact of Gut Microbiota on Postoperative Complications in Visceral Surgery-A Narrative Review

Postoperative complications are a major problem occurring in up to 50% of patients undergoing major abdominal surgery. Occurrence of postoperative complications is associated with a significantly higher morbidity and mortality in affected patients. The most common postoperative complications are caused by an infectious genesis and include anastomotic leakage in case of gastrointestinal anastomosis and surgical site infections. Recent research highlighted the importance of gut microbiota in health and disease. It is plausible that the gut microbiota also plays a pivotal role in the development of postoperative complications. This narrative review critically summarizes results of recent research in this particular field. The review evaluates the role of gut microbiota alteration in postoperative complications, including postoperative ileus, anastomotic leakage, and surgical site infections in visceral surgery. We tried to put a special focus on a potential diagnostic value of pre- and post-operative gut microbiota sampling showing that recent data are inhomogeneous to identify a high-risk microbial profile for development of postoperative complications.

Risks of anastomotic leakage in patients with colorectal cancer after operation and how to effectively avoid it

Despite the considerable progress in surgical level and imaging examination methods, anastomotic leakage is still the major complication after intestinal surgery with high incidence rate and mortality rate. Moreover, anastomotic leakage has become one of the serious complications threatening the postoperative life safety, prognosis and quality of life. The occurrence of anastomotic leakage involves the changes of a variety of pathophysiological factors, and is affected by intestinal microbiota, inflammation and immune system. Preoperative intestinal preparation will change the type and number of microbial population in the intestine. Intraoperative anastomotic mode and bleeding volume are also closely related to the occurrence of anastomotic leakage. In addition, the occurrence of anastomotic leakage is associated with local recurrence of colorectal cancer after surgery. Intraoperative protective stoma is confirmed to reduce the incidence of anastomotic leakage. Combined preoperative adjustment of nutritional status and inflammatory factors is important for avoiding anastomotic leakage after surgery.

The Role of Heart Rate, Body Temperature, and Respiratory Rate in Predicting Anastomotic Leakage following Surgery for Rectal Cancer

Objective

To explore the value of the heart rate, body temperature, and respiratory rate in the early prediction of anastomotic leakage after rectal cancer surgery.

Methods

Clinical data from patients with rectal cancer who underwent anterior rectal resection in the Department of Gastroenterology, Renmin Hospital of Wuhan University, from January 2017 to December 2019 were collected and analyzed retrospectively. Based on the occurrence of anastomotic leakage after surgery, the patients were divided into two groups: those with and without anastomotic leakage. The quantitative values of the heart rate, body temperature, and respiration rate at day 7 postsurgery were compared between the two groups. The ROC curve was used to analyze their role in the early prediction of anastomotic leakage.

Results

Among 441 patients with rectal cancer, 30 (6.81%) had clinical anastomotic leakage and were diagnosed at 7 ± 3 days postsurgery. Within 7 days postsurgery, the heart rate, body temperature, and respiratory rate in the anastomotic leakage group were higher than those in the nonanastomotic leakage group. The differences in heart rate (1-5 d), body temperature (2-7 d), and respiratory rate (1-7 d) were statistically significant (P < 0.05). The three ROC curves were drawn, respectively. The predictive value of the heart rate is greatest at days 2-3 postsurgery. The predictive value of the body temperature is greatest at days 4-6 postsurgery. The predictive value of the respiratory rate is best at days 1-4 postsurgery.

Conclusion

The changes of vital signs (heart rate, body temperature, and respiratory rate) have a certain value in the early prediction of anastomotic leakage after rectal cancer surgery. Observation of postoperative vital signs at 7 days postsurgery is helpful for the early diagnosis of anastomotic leakage.

Biomaterial-Assisted Anastomotic Healing: Serosal Adhesion of Pectin Films

Anastomotic leakage is a frequent complication of intestinal surgery and a major source of surgical morbidity. The timing of anastomotic failures suggests that leaks are the result of inadequate mechanical support during the vulnerable phase of wound healing. To identify a biomaterial with physical and mechanical properties appropriate for assisted anastomotic healing, we studied the adhesive properties of the plant-derived structural heteropolysaccharide called pectin. Specifically, we examined high methoxyl citrus pectin films at water contents between 17-24% for their adhesivity to ex vivo porcine small bowel serosa. In assays of tensile adhesion strength, pectin demonstrated significantly greater adhesivity to the serosa than either nanocellulose fiber (NCF) films or pressure sensitive adhesives (PSA) (p < 0.001). Similarly, in assays of shear resistance, pectin demonstrated significantly greater adhesivity to the serosa than either NCF films or PSA (p < 0.001). Finally, the pectin films were capable of effectively sealing linear enterotomies in a bowel simulacrum as well as an ex vivo bowel segment. We conclude that pectin is a biomaterial with physical and adhesive properties capable of facilitating anastomotic healing after intestinal surgery.

Continuous negative pressure irrigation with double cannula through the anterior sacral space for treatment of anastomotic fistula after anus-preserving laparoscopic radical resection for ultra-low rectal cancer in elderly patients

BACKGROUND

Ultra-low rectal cancer refers to rectal cancer where the lower edge of the tumor is less than 5 cm from the dentate line. It is mostly caused by genetics, diet, chronic inflammation of the large intestine, and many other factors. Surgery is the main method of treatment for rectal cancer. Although surgery can effectively control the deterioration of the disease and remove the diseased tissue, postoperative complications such as anastomotic leakage often occur, which is not conducive to the prognosis and even threatens the life and health of patients. The prevention and treatment of anastomotic leakage in elderly patients after surgery are a clinical focus and difficulty.

AIM

To evaluate the effect of continuous negative pressure irrigation with double cannula through the anterior sacral space in the treatment of anastomotic fistula after anus-preserving laparoscopic radical resection for ultra-low rectal cancer in elderly patients (over 60 years old).

METHODS

One hundred and eighteen elderly patients with anastomotic fistula after laparoscopic radical resection for ultra-low rectal cancer from November 2018 to October 2020 were selected and classified into either a control group or an experimental group according to the order of admission. The control group (59 cases) underwent single-chamber drainageed, and the experimental group (59 cases) received continuous negative pressure irrigation with double cannula through the presacral space. The efficacy, time to recovery of various indications, postoperative function, and inflammatory factors were compared between the two groups.

RESULTS

The total effective rate in the experimental group (98.31%) was significantly higher than that of the control group (84.75%), and the time to extubation, time to recovery of normal body temperature, healing time, time to disappearance of lower abdominal pain, and hospital stay were significantly shorter than those of the control group (P < 0.05). The visual analogue assessment scale score of the experimental group was significantly lower than that of the control group after 2 wk of treatment, and the granulation growth grade and EORTC quality of life measurement scale score were significantly higher than those of the control group (P < 0.05). After 2 wk of treatment, white blood cell count, erythrocyte sedimentation rate, C-reactive protein, and procalcitonin were significantly lower, and vascular endothelial growth factor level was significantly higher in the experimental group than in the control group (P < 0.05).

CONCLUSION

Double cannula continuous negative pressure flushing through the presacral space is effective in the treatment of anastomotic fistula after anus-preserving laparoscopic radical resection for ultra-low rectal cancer in elderly patients, and it can quickly relieve clinical symptoms, promote the growth of fresh granulation, inhibit the release of inflammatory factors, and improve life quality.

Oxidative Stress Level as a Predictor of Anastomotic Leakage after Rectal Surgery

Background

Early diagnosis of anastomotic leakage (AL) after rectal surgery can reduce the adverse effects of AL, thereby reducing morbidity and mortality. Currently, there are no accepted indicators or effective scoring systems that can clearly identify patients at risk of anastomotic leakage.

Methods

A prospective study with assessment of the diagnostic accuracy of oxidative stress level (CAT, SOD, MDA) in serum and drain fluid compared to white blood cell count (WBC), C-reactive protein (CRP), and neutrophil percentage (NEUT) in prediction of AL in patients undergoing elective rectal surgery with anastomosis.

Results

Most of the oxidative stress indicators we detected are of considerable significance in the diagnosis of anastomotic leakage. The level of MDA on postoperative day (POD)3 (areas under the curve (AUC): 0.831) and POD5 (AUC: 0.837) in the serum and on POD3 (AUC: 0.845) in the drain fluid showed the same excellent diagnostic accuracy as the level of CRP on the POD3 (AUC: 0.847) and POD5 (AUC: 0.896).

Conclusions

The overall level of oxidative stress in serum and drain fluid is a reliable indicator for the early diagnosis of anastomotic leakage after rectal surgery. More specifically, among the redox indicators analyzed, MDA has almost the same predictive value as CRP, which provides another useful biomarker for the early diagnosis of anastomotic leakage.

Timing of Tributyrin Supplementation Differentially Modulates Gastrointestinal Inflammation and Gut Microbial Recolonization Following Murine Ileocecal Resection

BACKGROUND

Gastrointestinal surgery imparts dramatic and lasting imbalances, or dysbiosis, to the composition of finely tuned microbial ecosystems. The aim of the present study was to use a mouse ileocecal resection (ICR) model to determine if tributyrin (TBT) supplementation could prevent the onset of microbial dysbiosis or alternatively enhance the recovery of the gut microbiota and reduce gastrointestinal inflammation.

METHODS

Male wild-type (129 s1/SvlmJ) mice aged 8-15 weeks were separated into single cages and randomized 1:1:1:1 to each of the four experimental groups: control (CTR), preoperative TBT supplementation (PRE), postoperative TBT supplementation (POS), and combined pre- and postoperative supplementation (TOT). ICR was performed one week from baseline assessment with mice assessed at 1, 2, 3, and 4 weeks postoperatively. Primary outcomes included evaluating changes to gut microbial communities occurring from ICR to 4 weeks.

RESULTS

A total of 34 mice that underwent ICR (CTR n = 9; PRE n = 10; POS n = 9; TOT n = 6) and reached the primary endpoint were included in the analysis. Postoperative TBT supplementation was associated with an increased recolonization and abundance of anaerobic taxa including Bacteroides thetaiotomicorn, Bacteroides caecimuris, Parabacteroides distasonis, and Clostridia. The microbial recolonization of PRE mice was characterized by a bloom of aerotolerant organisms including Staphylococcus, Lactobacillus, Enteroccaceae, and Peptostreptococcacea. PRE mice had a trend towards decreased ileal inflammation as evidenced by decreased levels of IL-1β (p = 0.09), IL-6 (p = 0.03), and TNF-α (p < 0.05) compared with mice receiving TBT postoperatively. In contrast, POS mice had trends towards reduced colonic inflammation demonstrated by decreased levels of IL-6 (p = 0.07) and TNF-α (p = 0.07). These changes occurred in the absence of changes to fecal short-chain fatty acid concentrations or histologic injury scoring.

CONCLUSIONS

Taken together, the results of our work demonstrate that the timing of tributyrin supplementation differentially modulates gastrointestinal inflammation and gut microbial recolonization following murine ICR.

Mucosa plication reinforced colorectal anastomosis and trans-anal vacuum drainage: a pilot study with preliminary results

Dehiscence of colorectal anastomosis is a serious complication that is associated with increased mortality, impaired functional and oncological outcomes. The hypothesis was that anastomosis reinforcement and vacuum trans-anal drainage could eliminate some risk factors, such as mechanically stapled anastomosis instability and local infection. Patients with rectal cancer within 10 cm of the anal verge and low anterior resection with double-stapled technique were included consecutively. A stapler anastomosis was supplemented by trans-anal reinforcement and vacuum drainage using a povidone-iodine-soaked sponge. Modified reinforcement using a circular mucosa plication was developed and used. Patients were followed up by postoperative endoscopy and outcomes were acute leak rate, morbidity, and diversion rate. The procedure was successfully completed in 52 from 54 patients during time period January 2019–October 2020. The mean age of patients was 61 years (lower–upper quartiles 54–69 years). There were 38/52 (73%) males and 14/52 (27%) females; the neoadjuvant radiotherapy was indicated in a group of patients in 24/52 (46%). The mean level of anastomosis was 3.8 cm (lower–upper quartiles 3.00–4.88 cm). The overall morbidity was 32.6% (17/52) and Clavien–Dindo complications ≥ 3 grade appeared in 3/52 (5.7%) patients. No loss of anastomosis was recorded and no patient died postoperatively. The symptomatic anastomotic leak was recorded in 2 (3.8%) patients and asymptomatic blind fistula was recorded in one patient 1/52 (1.9%). Diversion ileostomy was created in 1/52 patient (1.9%). Reinforcement of double-stapled anastomosis using a circular mucosa plication with combination of vacuum povidone-iodine-soaked sponge drainage led to a low acute leak and diversion rate. This pilot study requires further investigation.

Registered at ClinicalTrials.gov.: Trial registration number is NCT04735107, date of registration February 2, 2021, registered retrospectively.

Analysis of Cumulative Fluid Balance Impact on the Stability of Gastrointestinal Tract Anastomosis

Anastomotic leakage is a serious postoperative complication following a low anterior resection of rectum. Current research in colorectal surgery focuses on searching for techniques which could minimize the risk of leakage. The main objective of this study was to evaluate the impact of cumulative fluid balance on microcirculatory changes at the anastomotic site.This experimental study used 15 domestic pigs; all of the animals underwent rectal resection. Then the animals were divided into three groups and received IV crystalloids at various rates, i.e. 5 ml/kg/h; 10 ml/kg/h; and 20 ml/kg/h. Large bowel micro-perfusion was measured using laser Doppler flowmetry during and following the surgical procedure.The experiments were successfully performed in all 15 cases. No animal died during the procedure or during the follow-up. We found no differences in micro-perfusion of the bowel between the experimental groups during the surgical procedure and during the follow-up period after the surgery. A significant decrease in micro-perfusion was observed after the transection of the inferior mesenteric artery in all the groups; again, no differences between the groups were observed.We did not confirm the original hypothesis that excessive load of IV crystalloids during the surgery would have a negative effect on bowel micro-perfusion and thus a negative effect on the healing of the anastomosis. However, laser Doppler flowmetry was found to have high accuracy in measuring tissue microcirculation and has the potential to be used in clinical practice.

Hypocalcemia: A possible risk factor for anastomotic leak in digestive surgery

Anastomotic leaks (ALs) remain the most severe complication in digestive surgery, as well as the most consumptive in terms of human and financial resources. There is an abundance of international research which has focused on identifying and correcting risk factors, and on individualized surgical management as well. The most frequent risk factors are male sex, obesity, diabetes, advanced malignant disease, ASA score, perioperative blood loss or perioperative transfusion, long operation time, emergency operation and altered nutritional status. The aim of the present study was to measure the preoperative serum calcium level and to find a possible correlation between calcium levels and the risk of AL occurrence. A retrospective analysis of medical records for 122 patients who underwent surgical gut resection with anastomosis for different pathologies was carried out. Preoperative serum calcium level and the occurrence of AL was noted. The results revealed that the average value of total blood calcium was 8.78 mg/dl, without a significant difference in sex groups. Hypocalcemia was identified in 44 patients (36.1%). AL was identified in 8 patients (6.6%), with a statistically insignificant difference between male and female patients. The average value of blood calcium in the AL patient group was 8.07 mg/dl, while in patients without AL the average value was 8.83 mg/dl. Hypocalcemia, defined as a serum calcium level below 8.5 mg/dl, was observed in 7 of the 8 patients presenting with AL (87.5%) and 37 patients who did not present with AL (32.5%), a significant difference with which to consider and include hypocalcemia in the group of risk factors for AL (P=0.001). In conclusion, preoperative low serum calcium level can represent a risk factor for AL in digestive surgery.