Is the intraoperative air leak test effective in the prevention of colorectal anastomotic leakage? A systematic review and meta-analysis

Usefulness of intraoperative colonoscopy and synchronous scoring system for determining the integrity of the anastomosis in left-sided colectomy: a single-center retrospective cohort study

OBJECTIVES

The aim of this study is to evaluate the utilization of intraoperative colonoscopy (IOC) for determining the integrity of the anastomosis and to establish an IOC scoring system.

METHODS

A retrospective cohort study was conducted from January 2021 to June 2024, we analyzed the clinical data of 160 patients registered in a database who underwent laparoscopic left-sided colectomy at Pusan National University Yangsan Hospital. IOC was performed on all patients, and Mucosal color (MC), stapled line bleeding (BL), proximal redundancy (PR), and bowel preparation (BP) were evaluated and scored as variables. Logistic regression analysis was used to evaluate risk factors for anastomotic leakage (AL) and Cohen's kappa was applied to assess the reproducibility of the evaluation.

RESULTS

Of 160 patients, 10 (6.25%) experienced AL. All the IOC variables had kappa values of 0.8 or higher, indicating good agreement. The logistic regression analysis revealed significant differences in the MC 2 (P = 0.017, OR 12.86), PR 2 (P = 0.001, OR 27.64), BP 2 (p = 0.016, OR 10.50) PR 2 score (P = 0.016, OR 10.50) and the sum of the scores (p = 0.001, OR 3.51).

CONCLUSION

IOC can be performed as a reference procedure to assess the integrity of the anastomosis during left-sided colorectal surgery.

Air Leak Test: Extending the Horizon From the Bowel to Pancreatoduodenectomy

Background Intraoperative air leak test (ALT) is routinely used to check anastomosis of the stomach, small intestine, and rectum. Its advantage is that it repairs the leak at the same time, thus preventing postoperative complications and re-exploration. Method ALT was done by insufflating the stomach with air to check the integrity of gastrojejunal anastomoses (GJ); the same air was pushed into the afferent jejunal limb to distend it up to hepaticojejunostomy (HJ) and pancreaticojejunostomy (PJ), thus testing the leak at all three anastomoses. ALT was performed in 16 patients (group 1) and the results were compared with 52 patients (group 2) who underwent pancreatoduodenectomy (PD) without ALT, between August 2019 and December 2022. Results ALT revealed a GJ leak in two and an HJ leak in one out of 16 patients, all of which were repaired immediately. It did not reveal any PJ leak. No postoperative bile leak was seen in group 1, while postoperative bile leak was seen in five of 52 patients in group 2 on postoperative day (POD) 1. High drain fluid amylase in the left drain on POD 3 was present in 11 patients (69%) in group 1 and 30 patients (44%) in group 2. A right drain was removed two days earlier and a left drain one day earlier in group 1. Reintervention and 30-day mortality were higher in group 2. Hospital stay was shorter (7.4 versus 8.2 days) in group 1. Conclusion Intraoperative ALT identified an anastomotic leak from GJ and HJ but not PJ, facilitating its immediate repair, thus preventing serious postoperative complications following PD. Whether ALT has any role in the detection of a PJ leak needs further validation.

New alternative colorectal anastomotic devices: A systematic review and meta-analysis

BACKGROUND

Colorectal anastomotic devices have been used for nearly a century, with stapled anastomoses being the most common despite leak rates up to 20 ​%. This review aimed to evaluate newer alternative devices.

METHOD

A systematic review and meta-analysis of publications from the last decade were conducted, focusing on devices forming colorectal anastomoses, excluding those facilitating sutured or stapled anastomoses or designed to prevent leaks. Data from MEDLINE, Embase, Cochrane, and ClinicalTrials.gov were analysed.

RESULTS

Eighteen studies (7 human, 10 animal, 1 ex-vivo) involving 955 anastomoses were included. Compression mechanisms were the most common. The pooled complication rate in human studies was 9.7 ​% (95 ​% CI: 4.3-15.2 ​%) with significant heterogeneity (I2 ​= ​81.7 ​%). The leak rate after compression anastomoses was 3.3 ​% (95 ​% CI: 1.9-4.7 ​%) with no heterogeneity (I2 ​= ​0 ​%). A novel device with transanal catheters allowed intraoperative and postoperative assessment.

CONCLUSIONS

Outcomes are comparable to existing methods, with new technologies offering promising advancements.

Is end-to-end or side-to-end anastomotic configuration associated with risk of positive intraoperative air leak test in left-sided colon and rectal resections for colon and rectal cancers?

BACKGROUND

Anastomotic leak after colorectal resection is associated with morbidity, mortality, and poor bowel function. Minimal data exist on the relationship between anastomotic technique, intraoperative leak test, and subsequent clinical leak, particularly on the utility of performing end-to-end anastomosis (EEA) vs non-EEA (NEEA) to avoid postoperative leaks. This study aimed to analyze potential associations between anastomotic construction, intraoperative anastomotic assessments, and clinical leak.

METHODS

This was a retrospective cohort study comparing anastomotic techniques used in patients with colorectal cancer who underwent left-sided colorectal resections with colorectal or coloanal anastomoses at a tertiary care center. The outcomes were rates of intraoperative air leak, incomplete anastomotic donuts, and postoperative clinical leak. Univariate and multivariate analyses were performed to evaluate the potential association between anastomotic technique and intraoperative anastomotic assessments and subsequent leak.

RESULTS

Among 844 patients, 27 (3.2%) had intraoperative leak, 6 (0.7%) had incomplete donuts, and 27 (3.2%) experienced clinical leak. Of note, 500 patients (59.2%) had EEAs, and 344 patients (40.7%) had NEEAs. There were no significant differences in demographics or comorbidities between groups (P >.05) or rates of incomplete donuts (P =.07). EEA was associated with significantly more intraoperative air leaks than NEEA on univariate analysis (4.9% vs 1.2%, respectively; P =.005) and multivariate analysis (odds ratio [OR], 3.6; 95% CI, 1.01-12.50; P =.049). There was no difference in postoperative clinical leak between the groups on univariate analysis (3.0% in EEA vs 3.5% in NEEA; P =.69) or multivariate analysis (OR, 0.97; 95% CI, 0.40-2.34; P =.94).

CONCLUSION

EEA is associated with higher rates of intraoperative air leak than NEEA, even after adjusting for potential confounders.

Is It Necessary to Endoscopically Evaluate the Anastomosis in Robotic or Laparoscopic Surgical Procedures for Colorectal Cancer?

Background: In the surgical treatment of colorectal cancers, disease-free survival and life expectancy are inversely proportional to the increase in complications. We evaluated the superiority of colonoscopy and air and water tests in detecting anastomotic leaks in sigmoid and rectosigmoid junction colon cancers. Methods: Data of patients who underwent robotic/laparoscopic surgical procedures for sigmoid and rectosigmoid junctional colon cancers at a single center between January 2018 and February 24 were retrospectively evaluated. The anastomoses were evaluated by intraoperative colonoscopy (IOC) and intraoperative air leak test (IALT), and two groups were formed. Intraoperative leaks, intraoperative repair techniques, and postoperative anastomotic leaks were evaluated. Results: In our study, there were 125 patients in the IOC group and 148 patients in the IALT group, totaling 273 patients. Leakage was detected in 7 patients (4.7%) in the IALT group and 14 patients (11.2%) in the IOC group (P = .06). In the IALT group, 5 of 7 patients were repaired primary, and the anastomosis was reconstructed in 2 patients. In the IOC group, 10 of 14 patients were repaired primary, 2 patients underwent reanastomosis, and 2 patients needed colostomy. Of these 15 patients with postoperative leakage, 4 had intraoperative leakage (2 patients in the IALT group and 2 patients in the IOC group), and all of them underwent primary repair. Conclusion: In the anastomotic evaluation of sigmoid colon and rectosigmoid junction tumors, we found that IOC detected more leaks than IALT, but in these leaks, reanastomosis and/or diversion ostomy was superior to primary repair.

Clinical Practice Guideline: Recommendations for the Perioperative Management of Pancreatic and Colorectal Cancer Patients

BACKGROUND

Colorectal and pancreatic carcinoma are the most common cancers of the gastrointestinal tract. Their surgical treatment carries a high morbidity: complications arise in 25% to 30% of cases, often prolonging recovery times and delaying the initiation of adjuvant therapy, leading, in turn, to worse oncological outcomes. The goal of multimodal perioperative management (mPOM) is to lower the postoperative complication rate through a combination of perioperative measures.

METHODS

This guideline on the perioperative management of gastrointestinal tumors (POMGAT) meets all requirements for an S3 guideline as specified by the Association of the Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF). These include a systematic literature search, quality assessment of the included publications, an evaluation of the reliability of the evidence according to the GRADE approach, and a structured consensus process.

RESULTS

Meta-analyses have shown that mPOM lowers the complication rates of both pancreatic and colorectal resections (RD 0.96 with 95% confidence interval [0.92; 0.99] and RR 0.66 [0.54; 0.80], respectively). This shortens the hospital stay after pancreatic resections by a median of 2.33 days [-2.98; -1.69] and after colorectal resections by a median of 2.59 days [-3.22; -1.97].

CONCLUSION

Adherence to the POMGAT-S3 guideline for pancreatic and colorectal cancer surgery is associated with improved recovery, which can lead to a faster return to intended oncological treatment (RIOT) and thus to better long-term outcomes. These recommendations are not restricted to gastrointestinal cancer surgery; they can also be applied to visceral surgery for benign conditions, as well as to gynecological and urological operations.

The Value of C-Reactive Protein and Peritoneal Cytokines as Early Predictors of Anastomotic Leak after Colorectal Surgery

OBJECTIVES

The aim of this study was to evaluate the accuracy of serum C-reactive protein (CRP) and intraperitoneal CRP, interleukin-6, and tumor necrosis factor-alpha in early diagnostics of anastomotic leakage in the first 4 postoperative days after colorectal surgery.

METHODS

Between January 2023 and June 2023, one hundred patients with colorectal carcinoma were operated on with primary anastomosis. Ten patients had anastomotic leak (10%).

RESULTS

Based on serum CRP, a patient with a leak will be detected with a 78% probability on postoperative day 3 with values above 169.0 mg/L and on postoperative day 4 with values equal to 159.0 mg/L and above. Intraperitoneal CRP values greater than 56 mg/L on the fourth postoperative day indicate a 78% probability of a diagnosis of leakage. An anastomotic leak will be detected with a 70.0% probability based on an IL-6 value on the first day, at a cut-off value of 42,150. The accuracy of TNF-alpha in predicting anastomotic leak in the first two days is 70% at values higher than 78.00 on the first and 58.50 on the second postoperative day.

CONCLUSION

In this study serum CRP proved to be the most accurate in predicting anastomotic dehiscence after colorectal surgery.

Quadruple Assessment of Colorectal Anastomosis after Laparoscopic Rectal Resection: A Retrospective Analysis of a Propensity-Matched Cohort

Background: Anastomotic leakage (AL) is one of the most feared complications in colorectal surgery, with an incidence of 12-39% and associated risk of mortality of 2-24%. The causes of AL and the ways to prevent it are currently under investigation. This study aims to verify if a quadruple assessment of colorectal anastomosis could reduce AL incidence. Methods: A retrospective analysis of prospectively collected data on rectal cancer surgery performed from January 2015 to December 2017 and from January 2021 to December 2023 at a tertiary referral cancer centre was performed. Demographics, clinicopathological features, short-term outcomes, recurrences, and survival were investigated. Results: A total of 293 patients were enrolled. AL incidence was lower in the quadruple assessment group than in the control group, reaching a statistically significant result (7.7% vs. 16%; p = 0.001). This result was also confirmed after a propensity score match analysis (PSM), in which the AL rate was lower in the quadruple assessment group (5.4% vs. 12.3%; p = 0.01). Conclusions: This study shows how the systematic implementation of a quadruple assessment when performing a colorectal anastomosis could increase awareness on anastomotic success and reduce the incidence of AL.

Poly-ϵ-caprolactone scaffold as staple-line reinforcement of rectal anastomosis: an experimental piglet study

PURPOSE

Rectal anastomoses have a persisting high incidence of anastomotic leakage. This study aimed to assess whether the use of a poly-ϵ-caprolactone (PCL) scaffold as reinforcement of a circular stapled rectal anastomosis could increase tensile strength and improve healing compared to a control in a piglet model.

METHOD

Twenty weaned female piglets received a stapled rectal anastomosis and were randomised to either reinforcement with PCL scaffold (intervention) or no reinforcement (control). On postoperative day five the anastomosis was subjected to a tensile strength test followed by a histological examination to evaluate the wound healing according to the Verhofstad scoring.

RESULTS

The tensile strength test showed no significant difference between the two groups, but histological evaluation revealed significant impaired wound healing in the intervention group.

CONCLUSION

The incorporation of a PCL scaffold into a circular stapled rectal anastomosis did not increase anastomotic tensile strength in piglets and indicated an impaired histologically assessed wound healing.

A Novel Fluorescence-Based Leak Test Method for Rectal Anastomoses Using Aerosolized Indocyanine Green

BACKGROUND

The intraoperative air leak test is commonly performed during rectal surgery to evaluate anastomotic integrity. However, its drawbacks include occasional difficulties in visualizing the exact point of the leak while maintaining the pelvis under saline, the need for repeat testing to identify the leak point, and a lack of continuous visualization of the leak point.

OBJECTIVE

To evaluate the feasibility and clinical applicability of using aerosolized indocyanine green, a fluorescent tracer, for detecting rectal anastomotic leakage.

DESIGN

Animal preclinical study.

SETTING

Animal laboratory at Kagawa University.

PATIENTS

Six healthy adult female beagles were included.

INTERVENTIONS

An anastomotic leakage model with a single air leak point was created in each dog. Indocyanine green was aerosolized using a nebulizer kit with a stream of carbon dioxide flowing at 1.5 to 2.0 L/min. The aerosol was administered into the rectum transanally, and laparoscopic observations were performed.

MAIN OUTCOME MEASURES

Air leak points were observed using a near-infrared fluorescence laparoscope, after which the presence of corresponding indocyanine green fluorescence was verified.

RESULTS

Aerosolized indocyanine green was visualized laparoscopically at all anastomosis sites but not elsewhere. The median time from the administration of the aerosol to its visualization was 4.5 seconds. Pathological examinations were performed 4 weeks postsurgery in all dogs, and no histological abnormalities related to aerosolized indocyanine green administration were observed at the anastomosis sites.

LIMITATIONS

The leak points were surgically created and did not occur naturally.

CONCLUSIONS

Visualization of air leaks at the sites of rectal anastomosis was laparoscopically achievable by administering aerosolized indocyanine green transanally into the rectum in our canine model. This novel fluorescent leak test could be a valid alternative to established methods.

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.

Risk assessment of rectal anastomotic leakage (RAREAL) after DIXON in non-emergency patients with rectal cancer

BACKGROUND

The routine establishment of a diverting stoma (DS) remains controversial in every patient undergoing Dixon operation. We aimed to establish a model for the risk assessment of rectal anastomotic leak (RAREAL) after Dixon in non-emergency patients with rectal cancer, using routinely available variables, by which surgeons could individualize their approach to DS.

METHODS

323 patients who underwent Dixon operation for rectal cancer from January 2015 to December 2018 were taken as the model group for retrospective study. Univariable and multivariable logistic regression analysis was used to determine the independent risk factors associated with anastomotic leakage. We constructed the RAREAL model. 150 patients who underwent Dixon operation due to rectal cancer from January 2019 to December 2020 were collected according to the uniform criteria as a validation group to validate the RAREAL model.

RESULTS

In the model group, multivariable analysis identified the following variables as independent risk factors for AL: HbA1c (odds ratio (OR) = 4.107; P = 0.044), Left colic artery (LCA) non preservation (OR = 4.360; P = 0.026), Tumor distance from the anal margin (TD) (OR = 6.373; P = 0.002). In the model group, the area under the curve (AUC) of the receiver operating characteristic (ROC) for evaluating AL with RAREAL was 0.733, and when RAREAL score = 2.5, its sensitivity, specificity and Youden index were 0.385, 0.973, 0.358, respectively. The AUC was 0.722 in the validation group and its sensitivity and specificity were 0.333 and 0.985, respectively, when RAREAL score = 2.5.

CONCLUSION

The RAREAL score can be used to assess the risk of AL after Dixon operation for rectal cancer, and prophylactic DS should be proactively done when the score is greater than 2.5.

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.

Evaluating Performance of Circular Staplers Using Comparative Test Methods for Evidence-Based Surgery

BACKGROUND

Circular stapler anastomosis is a common surgical procedure. Despite technological advancements, anastomotic leak remains a postoperative concern. Assessment of new technologies is impeded by variations in test methods and analysis, precluding outcome reproducibility and direct comparisons of results across studies. The development of robust and reproducible preclinical test methods is critical to accelerating stapling technology advancements.

METHODOLOGY

Leak pressure, staple line perfusion and security, and device removal force were quantified for triple-row (Tri-staple EEA, TriEEA) and double-row staplers (Echelon Circular Powered, ECP). Leak and perfusion testing were performed in vivo. Device removal force and staple line security testing were performed with synthetic medium using an Instron. Data were analyzed using unpaired student's t-test or Kruskal-Wallis test, with statistical significance defined as P < .05.

RESULTS

Leak pressure was 73% higher in TriEEA vs ECP (P = .016). TriEEA staple line failure force was lower than ECP at 40 and 50 mmHg (P = .001 and P = .023, respectively). Perfusion to the staple line was higher (148%) for TriEEA than for ECP (P = .003) and the force required to remove the device from its stapled anastomosis was 78% lower for TriEEA than for ECP (P < .001).

DISCUSSION/CONCLUSIONS

This report addresses a primary limitation in stapling research by presenting novel methodologies which enhance clinical relevance and provide sufficient detail for reproduction by independent investigators. These methods are applied to a comparison between triple-row and double-row staplers to demonstrate utility of new test methods in assessing key technology design features.

A multidimensional learning curve analysis of totally laparoscopic ileostomy reversal using a single surgeon' s experience

Purpose

Recently, totally laparoscopic ileostomy reversal (TLAP) has received increasing attention and exhibited promising short-term outcomes. The aim of this study was to detail the learning process of the TLAP technique.

Methods

Based on our initial experience with TLAP from 2018, a total of 65 TLAP cases were enrolled. Demographics and perioperative parameters were assessed using cumulative sum (CUSUM), moving average, and risk-adjusted CUSUM (RA-CUSUM) analyses.

Results

The overall mean operative time (OT) was 94 min and the median postoperative hospitalization period was 4 days, and there was an estimated 10.77% incidence rate of perioperative complications. Three unique phases of the learning curve were derived from CUSUM analysis, and the mean OT of phase I (1-24 cases) was 108.5 min, that of phase II (25-39 cases) was 92 min, and that of phase III (40-65 cases) was 80 min, respectively. There was no significant difference in perioperative complications between these 3 phases. Similarly, moving average analysis indicated that the operation time was reduced significantly after the 20th case and reached a steady state after the 36th case. Furthermore, complication-based CUSUM and RA-CUSUM analyses indicated an acceptable range of complication rates during the whole learning period.

Conclusion

Our data demonstrated 3 distinct phases of the learning curve of TLAP. For an experienced surgeon, surgical competence in TLAP can be grasped at around 25 cases with satisfactory short-term outcomes.

Efficacy of air leak test in detection of anastomotic leaks after rectal excision: a retrospective case-controlled study

Purpose

Although its efficacy is uncertain, an intraoperative air leak test (ALT) is commonly used to detect mechanical defects following bowel anastomosis. This study aimed to evaluate the efficacy of ALT to detect anastomotic leakage (AL) following rectal excision.

Methods

We reviewed our database for patients with rectal cancers who had undergone curative surgery between January 2012 and January 2018. Patients were grouped according to whether or not an ALT was performed. Propensity score analyses were performed to compare outcomes for groups in a 1:1 case-matched cohort.

Results

In total, 1,191 patients underwent rectal excision; 438 (219 in each group) formed the case-matched cohort for analysis. The protective stoma rate was 16.0% and 14.6% in the ALT and the no-ALT groups, respectively (P = 0.791). In the ALT group, 2 patients (0.9%) showed a positive result and were treated with rectal tube drainage, resulting in no leakage. There was no significant difference in postoperative AL rate between the groups (ALT group: 4.6% vs. no-ALT group: 4.1%, P > 0.999).

Conclusion

ALT played a minimal role in detecting AL following rectal excision. Further studies are warranted to validate our results and clarify whether AL can be prevented with ALT or alternative methods.

Techniques for Diagnosing Anastomotic Leaks Intraoperatively in Colorectal Surgeries: A Review

Colorectal cancer is one of the most common surgically curable malignancies worldwide, having a good prognosis even with liver metastasis. This improved patient outcome is marred by anastomotic leaks (AL) in operated patients of colorectal cancer despite a microscopically margin-negative resection (R0). Various risk factors have been attributed to causing this. Preoperative non-modifiable factors are age, male sex, cancer cachexia, and neoadjuvant chemo-radiotherapy, and modifiable factors are comorbidities, peripheral vascular disease, anemia, and malnutrition. Intraoperative risk factors include intraoperative surgical duration, blood loss and transfusions, fluid management, oxygen saturation, surgical technique (stapled, handsewn, or compression devices), and approach (open, laparoscopic, or robotic). Postoperative factors like anemia, infection, fluid management, and blood transfusions also have an effect. With the advent of enhanced recovery after surgery (ERAS) protocols, many modifiable factors can be optimized to reduce the risk. Prevention is better than cure as the morbidity and mortality of AL are very high. There is still a need for an intraoperative technique to detect the viability of anastomotic ends to predict and prevent AL. Prompt diagnosis of an AL is the key. Many surgeons have proposed using methods like air leak tests, intraoperative endoscopy, Doppler ultrasound, and near-infrared fluorescence imaging to decrease the incidence of AL. All these methods can minimize AL, resulting in significant intraoperative alterations to surgical tactics. This narrative review covers the methods of assessing of integrity of anastomosis during the surgery, which can help prevent anastomotic leakage.

The Colorectal Anastomosis: A Timeless Challenge

Colorectal anastomosis is a sophisticated problem that demands an elaborate discussion and an elegant solution. "Those who forget the past are condemned to repeat it." George Santayana, Life of Reason , 1905.

Early postoperative endoscopic evaluation of rectal anastomoses: a prospective cross-sectional study

BACKGROUND

Reported incidence of anastomotic leakage (AL) of rectal anastomoses is up to 29% with an overall mortality up to 12%. Nevertheless, there is no uniform evidence-based diagnostic procedure for early detection of AL. The objective of this prospective clinical trial was to demonstrate the diagnostic value of early postoperative flexible endoscopy for rectal anastomosis evaluation.

METHODS

Flexible endoscopy between 5 and 8th postoperative day was performed consecutively in 90 asymptomatic patients. Sample size calculation was made using the two-stage Simon design. Diagnostic value was measured by management change after endoscopic evaluation. Anastomoses were categorized according to a new classification. Study is registered in German Clinical Trials Register (DRKS00019217).

RESULTS

Of the 90 anastomoses, 59 (65.6%) were unsuspicious. 20 (22.2%) were suspicious with partial fibrin plaques (n = 15), intramural hematoma and/or local blood coagulum (n = 4) and ischemic area in one. 17 of these anastomoses were treated conservatively under monitoring. In three a further endoscopic re-evaluation was performed and as consequence one patient underwent endoscopic vacuum therapy. 11 (12.2%) AL were detected. Here, two could be treated conservatively under monitoring, four with endoscopic vacuum therapy and five needed revision surgery. No intervention-related adverse events occurred. A change in postoperative management was made in 31 (34.4%) patients what caused a significant improvement of diagnosis of AL (p < 0.001).

CONCLUSIONS

Early postoperative endoscopic evaluation of rectal anastomoses is a safe procedure thus allows early detection of AL. Early treatment for suspicious anastomoses or AL could be adapted to avoid severe morbidity and mortality.

Intraoperative Colonoscopy in Laparoscopic Rectal Cancer Surgery Reduces Anastomotic Leakage

Objectives:

Anastomotic leakage (AL) is the most severe complication of colorectal surgery and is a frequent cause of postoperative mortality. This study aimed to identify the risk factors for AL, including the type of air leak test (ALT) performed, in patients undergoing laparoscopic colorectal cancer surgery.

Methods:

This study involved a retrospective review of 201 patients who underwent elective laparoscopic procedures using circular stapled anastomosis for colorectal cancer between January 2015 and December 2020 at Kyorin University Hospital, Tokyo, Japan. In all cases, the distance from the anal verge to the anastomotic site was within 15 cm.

Results:

Overall, AL was observed in 16 patients (8.0%). Univariate analysis revealed that the risk factors for AL included diabetes (P = 0.068), tumor location (P = 0.049), level of anastomosis (P = 0.002), number of linear stapler firings (P = 0.007), and intraoperative colonoscopy (IOCS; P = 0.069). Multivariate analysis revealed that the level of anastomosis (P = 0.029) and IOCS (P = 0.039) were significant and independent risk factors for AL. One of the 107 patients undergoing ALT without IOCS and 3 of the 94 patients undergoing ALT with IOCS were proven to be positive for air leak. However, these four patients underwent additional suturing intraoperatively and developed no AL following surgery.

Conclusions:

This study identified the level of anastomosis and ALT with IOCS as predictors for AL. The results of our study indicate that ALT with IOCS may be more effective than ALT without IOCS in the diagnosis and prevention of AL.

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.

Initial experience with intraoperative testing and repair of colorectal anastomosis using a TAMIS approach after a positive leak test

Anastomotic leak is one of the most feared complications of colorectal anastomosis. Different techniques have been described for intraoperative testing of anastomotic integrity. These include air insufflation, methylene blue and endoscopic visualisation. If an anastomotic leak is identified intraoperatively, there are various management options. Redo anastomosis is a possibility, but may be difficult in some cases. Defunctioning is another option, but there is an associated morbidity and signficant detrimental effect on quality of life. Direct transanal repair is only possible when a low anastomosis has been performed. When the anastomotic leak occurs high in the rectum or a partial mesorectal excision is performed a transanal approach is technically very challenging. We present our experience with transanal minimally invasive surgery (TAMIS) approach for anastomotic assessment and repair in four patients. In all cases, a colorectal anastomosis was performed and the air insufflation test was positive. We assessed the anastomosis with TAMIS. In three cases, a defect was found and subsequently sutured. In one case, a scar in the rectal mucosa was found and reinforced with a suture. A protective ileostomy was performed in two cases, while in the other two cases, no stoma was added. All four patients were discharged with no further complications. Both protective ileostomies were taken down after radiological and endoscopic confirmation of anastomotic integrity and all 4 anastomoses remain intact after follow-up. TAMIS intraoperative assessment and repair of anastomotic leak is a safe and feasible technique whcih may avoid the need for a defunctioning stoma.

Impact of change in the surgical plan based on indocyanine green fluorescence angiography on the rates of colorectal anastomotic leak: a systematic review and meta-analysis

BACKGROUND

In the present study, patients with colorectal anastomoses that were assessed with indocyanine green (ICG) fluorescence angiography (FA) were compared to patients who had only white light visual inspection of their anastomosis. The impact of change in surgical plan guided by ICG-FA on anastomotic leak (AL) rates was assessed.

METHODS

PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were queried for eligible studies. Studies included were comparative cohort studies and randomized trials that compared perfusion assessment of colorectal anastomosis with ICG-FA and inspection under white light. Main outcome measures were change in surgical plan guided by ICG-FA and rates of AL. Risk of bias was assessed using RoB-2 and ROBINS-1 tools. Differences between the two groups in categorical and continuous variables were expressed as odds ratio (OR) with 95% confidence interval (CI) and weighted mean difference.

RESULTS

This systematic review included 27 studies comprising 8786 patients (48.5% males). Using ICG-FA was associated with significantly lower odds of AL (OR 0.452; 95% CI 0.366-0.558) and complications (OR 0.747; 95% CI 0.592-0.943) than the control group. The weighted mean rate of change in surgical plan based on ICG-FA was 9.6% (95% CI 7.3-11.8) and varied from 0.64% to 28.75%. A change in surgical plan was associated with significantly higher odds of AL (OR 2.73; 95% CI 1.54-4.82).

LIMITATIONS

Technical heterogeneity due to using different dosage of ICG and statistical heterogeneity in operative time and complication rates.

CONCLUSION

Assessment of colorectal anastomoses with ICG-FA is likely to be associated with lower odds of anastomotic leak than is traditional white light assessment. Change in plan based on ICG-FA may be associated with higher odds of AL. PROSPERO registration number: CRD42021235644.

Anastomotic leakage in colorectal cancer surgery

The safety of colorectal surgery for oncological disease is steadily improving, but anastomotic leakage is still the most feared and devastating complication from both a surgical and oncological point of view. Anastomotic leakage affects the outcome of the surgery, increases the times and costs of hospitalization, and worsens the prognosis in terms of short- and long-term outcomes. Anastomotic leakage has a wide range of clinical features ranging from radiological only finding to peritonitis and sepsis with multi-organ failure. C-reactive protein and procalcitonin have been identified as early predictors of anastomotic leakage starting from postoperative day 2-3, but abdominal-pelvic computed tomography scan is still the gold standard for the diagnosis. Several treatments can be adopted for anastomotic leakage. However, there is not a universally accepted flowchart for the management, which should be individualized based on patient's general condition, anastomotic defect size and location, indication for primary resection and presence of the proximal stoma. Non-operative management is usually preferred in patients who underwent proximal faecal diversion at the initial operation. Laparoscopy can be attempted after minimal invasive surgery and can reduce surgical stress in patients allowing a definitive treatment. Reoperation for sepsis control is rarely necessary in those patients who already have a diverting stoma at the time of the leak, especially in extraperitoneal anastomoses. In patients without a stoma who do not require abdominal reoperation for a contained pelvic leak, there are several treatment options, including laparoscopic diverting ileostomy combined with trans-anal anastomotic tube drainage, percutaneous drainage or recently developed endoscopic procedures, such as stent or clip placement or endoluminal vacuum-assisted therapy. We describe the current approaches to treat this complication, as well as the clinical tests necessary to diagnose and provide an effective therapy.

Impact of intraoperative colonoscopy on anastomotic leakage detection and prevention in colorectal anastomosis for rectal cancer

INTRODUCTION AND AIM

The value of leakage testing during colorectal resections to identify anastomotic leaks or bleeding has not been established. Our aim was to compare the impact of intraoperative colonoscopy (IOC) versus insufflation with a syringe, as leakage testing in lower anterior resection (LAR) for rectal cancer, with respect to the incidence of postoperative leakage (PL).

MATERIALS AND METHODS

A retrospective study utilizing a prospective database of 426 patients with rectal cancer that underwent elective LAR, within the time frame of January 2015 and December 2019, was conducted. The anastomotic leak test was chosen by the surgeon. The incidence of postoperative leakage was compared between patients that underwent IOC and those that had the syringe leak test, utilizing the logistic regression analysis. Propensity score matching was included.

RESULTS

There were no significant differences in the clinical characteristics or morbidity and mortality rates between the two groups. Four patients were excluded, leaving a patient total of 422. Seventy patients with IOC were compared with 352 that had the syringe leak test. The incidence of postoperative leakage was 5.7% in the IOC group and 12.2% in the control group (p = 0.001). After propensity score matching (n = 221), balancing the characteristics between the groups, the incidence of postoperative leakage was 5.7% in the IOC group and 13.9% in the syringe leak test group (p = 0.001).

CONCLUSION

IOC was shown to be a safe method for evaluating the integrity of colorectal anastomosis and was associated with a higher percentage of protective stoma use, appearing to reduce the risk for PL.

Brazilian society of surgical oncology: Guidelines for the surgical treatment of mid-low rectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third leading cause of cancer in North America, Western Europe, and Brazil, and represents an important public health problem. It is estimated that approximately 30% of all the CRC cases correspond to tumors located in the rectum, requiring complex multidisciplinary treatment. In an effort to provide surgeons who treat rectal cancer with the most current information based on the best evidence in the literature, the Brazilian Society of Surgical Oncology (SBCO) has produced the present guidelines for rectal cancer treatment that is focused on the main topics related to daily clinical practice.

OBJECTIVES

The SBCO developed the present guidelines to provide recommendations on the main topics related to the treatment of mid-low rectal cancer based on current scientific evidence.

METHODS

Between May and June 2021, 11 experts in CRC surgery met to develop the guidelines for the treatment of mid-low rectal cancer. A total of 22 relevant topics were disseminated among the participants. The methodological quality of a final list with 221 sources was evaluated, all the evidence was examined and revised, and the treatment guideline was formulated by the 11-expert committee. To reach a final consensus, all the topics were reviewed via a videoconference meeting that was attended by all 11 of the experts.

RESULTS

The prepared guidelines contained 22 topics considered to be highly relevant in the treatment of mid-low rectal cancer, covering subjects related to the tests required for staging, surgical technique-related aspects, recommended measures to reduce surgical complications, neoadjuvant strategies, and nonoperative treatments. In addition, a checklist was proposed to summarize the important information and offer an updated tool to assist surgeons who treat rectal cancer provide the best care to their patients.

CONCLUSION

These guidelines summarize concisely the recommendations based on the most current scientific evidence on the most relevant aspects of the treatment of mid-low rectal cancer and are a practical guide that can help surgeons who treat rectal cancer make the best therapeutic decision.

Indocyanine Green Fluorescence in Colorectal Cancer

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

Efficacy of a robotic stapler on symptomatic anastomotic leakage in robotic low anterior resection for rectal cancer

PURPOSE

Clinical evidence demonstrating risk factors for anastomotic leakage including robotic staplers has remained limited, even though the use of robotic surgery has increased substantially. The purpose of this study was to evaluate the effects of robotic staplers on symptomatic anastomotic leakage in robotic low anterior resection for rectal cancer.

METHODS

A total of 427 consecutive patients with primary rectal cancer who underwent robotic low anterior resection without diverting stoma were investigated retrospectively. Symptomatic anastomotic leakage was defined as anastomotic leakage of Clavien-Dindo Grade ≥ II. We compared the symptomatic anastomotic leakage rates between manual and robotic staplers using propensity score matching and investigated the risk factors for symptomatic anastomotic leakage.

RESULTS

After propensity score matching, 168 pairs of manual and robotic stapler cases were selected. The symptomatic anastomotic leakage rate was significantly higher for manual staplers (6.5%) than for robotic staplers (1.2%, p = 0.02). In a multivariate analysis, the use of a manual stapler (p = 0.04, OR 4.86, 95% CI 1.08-21.8) and anastomosis < 4 cm from the anal verge (p < 0.01, OR 4.36, 95% CI 1.48-12.9) were identified as independent risk factors for symptomatic anastomotic leakage.

CONCLUSIONS

Robotic stapler use was associated with a significantly decreased rate of anastomotic leakage in robotic low anterior resection without diverting stoma for rectal cancer.

Ex vivo comparison of leak testing of canine jejunal enterotomies: Saline infusion versus air insufflation

OBJECTIVE

To compare the ability to detect leakage of enterotomy closures by intraluminal injection of saline or air.

STUDY DESIGN

Ex vivo study.

ANIMALS

Grossly normal jejunal segments (n = 60) from five fresh canine cadavers.

METHODS

Eight-centimeter jejunal segments were randomly assigned to two control (saline control [n = 5], air control [5]) and two treatment groups (injection of saline [n = 25] or air [25] after enterotomies were closed in a simple continuous pattern using 4-0 glycomer 631). Initial leak pressure (ILP, mean ± SD), maximum intraluminal pressure (MIP), and leakage location were compared. For all air insufflation constructs, the volume of air insufflated at the time of initial leakage was recorded.

RESULTS

The ILPs of control segments did not differ whether injected with saline (405.71 ± 56.97 mmHg) or air (376.84 ± 42.54, p = 1.00). Enterotomy closures leaked at lower pressures when injected with air (ILP: 68.52 ± 6.56) compared to saline (87.76 ± 5.20, p = .03). Similar results were obtained when comparing MIPs. A moderate association (r = .51) was identified between volume of air infused and ILPs. The strength of the association improved when stratified by cadaver. The location of leakage-most commonly suture tracks-was identified for all air constructs and for 14 of 25 saline constructs.

CONCLUSION

Enterotomy closures leaked at lower pressures after intraluminal injection of air compared to saline.

CLINICAL SIGNIFICANCE

Intraoperative leak testing of small intestinal enterotomy closures may be rendered more sensitive and precise by the use of air instead of saline as the infusate.

Intraoperative evaluation of colorectal anastomotic integrity: a comparison of air leak and dye leak tests

BACKGROUND

Air leak tests (ALTs) and dye leak tests (DLTs) are the most common techniques for Intraoperative colorectal anastomosis assessment. The aim of our study was to compare the sensitivity of ALT with DLT in intraoperative evaluation of colorectal anastomotic integrity and to quantify the pressures routinely used in these tests.

METHODS

A prospective clinical trial was conducted on patients who had elective colorectal resection and primary anastomosis from November 2017 until July 2019 in a single academic referral center. Each patient underwent both tests. The ALT was a transanal insufflation of CO₂ and inspection of escaping bubbles around the anastomosis immersed in saline. The DLT was a transanal infusion of diluted methylene blue and inspection of dye stains on surgical gauze wrapping the anastomosis. Peak pressures were measured. Primary endpoints were the sensitivity of ALT and DLT in detecting intraoperative leaks, quantification of intraluminal pressure routinely used in these settings and assessment of postoperative complications such as a clinical leak.

RESULTS

Forty patients underwent elective colorectal resection and anastomosis for malignant (67%) or benign n (33%) etiology. Height of anastomoses ranged from 1 to 25 cm (mean ± SD 12 ± 6 cm). Mean pressures measured were 26.5 ± 6.6 mmHg for the DLT and 22 ± 4 mmHg for the ALT (p < 0.01). Twenty percent of the DLTs were positive (8 patients) compared to 2.5% (1 patient) of the ALTs (RR 1.97, CI 1.2-2.7; p = 0.03). All patients who had positive tests had a suture reinforcement of the anastomosis. Only 1 patient, who had a positive DLT and ALT, developed a clinical leak CONCLUSIONS: DLT is more sensitive in detecting anastomotic leak intraoperatively. This is the first study measuring anastomotic tests' pressures used in-vivo in humans demonstrating a range of 20-30 mmHg. Based on our data we believe that a positive DLT with a negative ALT may be treated with suture reinforcement alone.

CLINICAL TRIAL NUMBER

NCT03316677-10/17/2017.

Does intraoperative flexible endoscopy offer any benefit compared to conventional air leak testing after circular stapled left-sided laparoscopic colon surgery?

BACKGROUND

Anastomotic leakage is still a feared complication after left-sided colonic resections. Various types of "anastomotic leak testing methods" are described in current literature. In this study we evaluated the use of intraoperative flexible endoscopy in comparison to conventional air leak testing after performing a circular stapled anastomosis in left-sided laparoscopic colon surgery.

METHODS

A retrospective database consisting of 130 patients with left sided colonic resections between 01/2015 and 12/2019 at our hospital was evaluated. After performing a circular stapled anastomosis flexible endoscopy was done in 69 cases, 61 patients were controlled with a conventional air leak test. Intraoperative and postoperative complications were recorded and retrospectively evaluated.

RESULTS

In the flexible endoscopy group, we observed complications in 13,04%, in the conventional air leak testing group in 9,83%. Postoperative anastomotic leakage was observed in 10,14% in the flexible endoscopy group and 4,91% in the conventional air leak test group. In 10,14% a positive air leak test was seen in the flexible endoscopy group and 11,47% in the conventional air leak testing group. In those cases, we observed no postoperative complications in the first group, in the conventional group we had two anastomotic leakages and one infected haematoma.

CONCLUSIONS

In the case of a positive air leak, flexible endoscopy offered a more exact detection of the leak. In those cases, no anastomotic leakage was observed postoperatively. In our opinion, flexible endoscopy should be recommended for testing the anastomosis intraoperatively in every left-sided colon surgery.

Evaluation of intraoperative leak testing of small intestinal anastomoses performed by hand-sewn and stapled techniques in dogs: 131 cases (2008-2019)

OBJECTIVE

To compare the rate of postoperative dehiscence on the basis of intraoperative anastomotic leak test results (ie, positive or negative for leakage or testing not performed) between dogs that underwent hand-sewn anastomosis (HSA) or functional end-to-end stapled anastomosis (FEESA) of the small intestine.

ANIMALS

131 client-owned dogs that underwent 144 small intestinal anastomoses (94 FEESA and 50 HSA).

PROCEDURES

Medical records were searched to identify dogs that had undergone a small intestinal anastomosis (HSA or FEESA) from January 2008 through October 2019. Data were collected regarding signalment, indication for surgery, location of the anastomosis, surgical technique, the presence of preoperative septic peritonitis, performance of intraoperative leak testing, development of postoperative dehiscence, and duration of follow-up.

RESULTS

Intraoperative leak testing was performed during 62 of 144 (43.1%) small intestinal anastomoses, which included 26 of 94 (27.7%) FEESAs and 36 of 50 (72.0%) HSAs. Thirteen of 144 (9.0%) anastomoses underwent dehiscence after surgery (median, 4 days; range, 2 to 17 days), with subsequent septic peritonitis, including 10 of 94 (10.6%) FEESAs and 3 of 50 (6.0%) HSAs. The incidence of postoperative dehiscence was not significantly different between FEESAs and HSAs; between anastomoses that underwent intraoperative leak testing and those that did not, regardless of anastomotic technique; or between anastomoses with positive and negative leak test results. Hand-sewn anastomoses were significantly more likely to undergo leak testing than FEESAs. Preoperative septic peritonitis, use of omental or serosal reinforcement, preoperative serum albumin concentration, and surgical indication were not significantly different between anastomotic techniques.

CONCLUSIONS AND CLINICAL RELEVANCE

Performance of intraoperative anastomotic leak testing, regardless of the anastomotic technique, was not associated with a reduction in the incidence of postoperative anastomotic dehiscence.

Surgical technique of visceral segmental serosectomy for advanced ovarian cancer

Tumors infiltrating the recto-sigmoid colon are commonly detected during cytoreductive surgery in patients with advanced ovarian cancer. Although radical excision using low anterior resection (LAR) is traditionally needed for optimal cytoreduction in the patients, LAR commonly decrease postoperative quality of life by changes of bowel habit. Since there is increasing evidence that conservative ablation of tumors on the recto-sigmoid colon may be safe and effective like LAR without compromising quality of life, we developed the surgical technique of visceral segmental serosectomy (VSS) as one of conservative ablation methods for complete resection of serosal implants on the recto-sigmoid colon and scrupulous restoration of extended serosal defect after resection. Thus, this video will show the step by step procedure of VSS during cytoreductive surgery for advanced ovarian cancer.

Intra-operative assessment of left-sided colorectal anastomotic integrity: a systematic review of available techniques

AIM

Anastomotic leak (AL) after colorectal resection is associated with increased rates of morbidity and mortality: potential permanent stoma formation, increased local recurrence, reduced cancer-related survival, poor functional outcomes and associated quality of life. Techniques to reduce leak rates are therefore highly sought.

METHOD

A literature search was performed for published full text articles using PubMed, Cochrane and Scopus databases with a focus on colorectal surgery 1990-2020. Additional papers were detected by scanning references of relevant papers.

RESULTS

A total of 53 papers were included after a thorough literature search. Techniques assessed included leak tests, endoscopy, perfusion assessment and fluorescence studies. Air-leak testing remains the most commonly used method across Europe, due to ease of reproducibility and low cost. There is no evidence that this reduces the leak rate; however, identification of a leak intra-operatively provides the opportunity for either suture reinforcement or formal takedown with or without re-do of the anastomosis and consideration of diversion. Suture repair alone of a positive air-leak test is associated with an increased AL rate. The use of fluorescence studies to guide the site of anastomosis has demonstrated reduced leak rates in distal anastomoses, is safe, feasible and has a promising future.

CONCLUSION

Although over reliance on any assessment tool should be avoided, intra-operative techniques with the aim of reducing AL rates are increasingly being employed. Standardization of these methods is imperative for routine use. However, in the interim it is recommended that all anastomoses should be assessed intra-operatively for mechanical failure, particularly distal anastomoses.

Review of Colonic Anastomotic Leakage and Prevention Methods

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

The "Reverse Air-Leak Test" : A New Technique for the Assessment of Low Colorectal Anastomosis

Background

Anastomotic leakage is a fearsome complication in rectal surgery. Surgeons perform the classic air-leak test, although its real effectiveness is still debated. The aim of this study was to describe a personal technique of reverse air leak test in which low colorectal anastomosis were assessed transanally through the intra-rectal irrigation of a few mL of saline solution.

Methods

From October 2014 to November 2019 eleven patients with low rectal cancer (Type 1 in Roullier classification) were included in this study. At the beginning of the procedure, a circular anal dilator (CAD) was inserted into the anus. A side-to-end colorectal anastomosis was performed. A few mL of saline solution were injected into the rectum and the entire anastomotic line was directly explored. The appearance of bubbles was considered as an anastomotic defect and repaired with an interrupted suture. A fluorescence angiography after intravenous injection of Indocyanine green was performed in order to evaluate the perfusion of the anastomosis.

Results

In 4 cases (36.3%) the reverse air-leak test was positive. The defect was repaired and a confirmation test was performed. In all patients, near-infrared evaluation showed not perfusion defect (grade 0) in low colorectal anastomosis. No post-operative fistula was detected in cohort study. A protective stoma was performed in 10 patients. At 90-days there were no complications and stoma closure was performed as planned.

Conclusion

The reverse air-leak test is a simple, feasible and effective procedure to identify anastomotic leak in low colorectal anastomoses.

Utility of intra-operative flexible sigmoidoscopy to assess colorectal anastomosis: a systematic review and meta-analysis

BACKGROUND

Anastomotic leak (AL) after colorectal resection leads to increased oncological and non-oncological, morbidity and mortality. Intra-operative assessment of a colorectal anastomosis with intra-operative flexible sigmoidoscopy (IOFS) has become increasingly prevalent and is an alternative to conventional air leak test. It is thought that intra-operative identification of an AL or anastomotic bleeding (AB) allows for immediate reparative intervention at the time of anastomosis formation itself. We aim to assess the available evidence for the use of IOFS to prevent complications following colorectal resection.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, a systematic review of the literature between January 1980 and June 2020 was performed. Comparative studies assessing IOFS versus conventional air leak test were compared, and outcomes were pooled.

RESULTS

A total of 4512 articles were assessed, of which eight were found to meet the inclusion criteria. A total of 1792 patients were compared; 884 in the IOFS arm and 908 in the control arm. IOFS was associated with an increase in the rate of positive leak test (odds ratio (OR) 5.21, P > 0.001), a decrease in AL (OR 0.45, P = 0.006) and a decrease in post-operative AB requiring intervention (OR 0.40, P = 0.037).

CONCLUSION

In a non-randomized meta-analysis, IOFS increases the likelihood of identifying an anastomotic defect or bleeding intra-operatively. This allows for immediate intervention that decreases the rate of AL and AB. This adds impetus for performing routine IOFS after a left-sided colorectal resection with anastomosis and highlights the need for randomized controlled trial to confirm the finding.

European Society of Coloproctology: guidelines for the management of diverticular disease of the colon

AIM

The goal of this European Society of Coloproctology (ESCP) guideline project is to give an overview of the existing evidence on the management of diverticular disease, primarily as a guidance to surgeons.

METHODS

The guideline was developed during several working phases including three voting rounds and one consensus meeting. The two project leads (JKS and EA) appointed by the ESCP guideline committee together with one member of the guideline committee (WB) agreed on the methodology, decided on six themes for working groups (WGs) and drafted a list of research questions. Senior WG members, mostly colorectal surgeons within the ESCP, were invited based on publication records and geographical aspects. Other specialties were included in the WGs where relevant. In addition, one trainee or PhD fellow was invited in each WG. All six WGs revised the research questions if necessary, did a literature search, created evidence tables where feasible, and drafted supporting text to each research question and statement. The text and statement proposals from each WG were arranged as one document by the first and last authors before online voting by all authors in two rounds. For the second voting ESCP national representatives were also invited. More than 90% agreement was considered a consensus. The final phrasing of the statements with < 90% agreement was discussed in a consensus meeting at the ESCP annual meeting in Vienna in September 2019. Thereafter, the first and the last author drafted the final text of the guideline and circulated it for final approval and for a third and final online voting of rephrased statements.

RESULTS

This guideline contains 38 evidence based consensus statements on the management of diverticular disease.

CONCLUSION

This international, multidisciplinary guideline provides an up to date summary of the current knowledge of the management of diverticular disease as a guidance for clinicians and patients.

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.

Bowel anastomosis leakage following endometriosis surgery: an evidence based analysis of risk factors and prevention techniques

BACKGROUND

Deep endometriosis most commonly involves the rectosigmoid junction and its management often requires a colorectal resection. Anastomotic leakage is a severe complication after resection and affects 1-6% of the cases.

OBJECTIVE

To evaluate the risk factors related to anastomotic leakage following endometriosis sur-gery, its prevention techniques and the role of protective stomas.

METHODS

A comprehensive literature review was carried out for English-language publications in Pubmed and Google Scholar. We included all studies including the following MeSH terms and key words: Anastomotic leakage AND bowel surgery OR Endometriosis OR Colorectal surgery OR Bowel endometriosis. Two authors independently made a selection and analysed relevant abstracts according to the aim of this review.

RESULTS

Risk factors and preventive measures were categorised considering the patient condition, the intra- operative setting and the surgical procedure itself. Level I and II recommendations include modifiable risk factors such as the use of stapled or handsewn anastomosis; intra-operative air leak test to check the integrity of the anastomosis; systematic use of pelvic and trans-anal drainage; application of protective or ghost ileostomy in low rectal resections; vaginal closure before the bowel resection; use of oral antibiotics the day before surgery and performing partial mesorectal resection near the bowel wall. Diverting stomas may decrease the morbidity and the clinical consequences of leakage over 65% of low rectal resections but may cause significant adverse effects.

CONCLUSION

Evidence-based protective actions are crucial to reduce clinical consequences of anastomotic leakage and to minimise the use of protective stomas in endometriosis surgery.

Innovative approaches for induction of gastrointestinal anastomotic healing: an update on experimental and clinical aspects

PURPOSE

In most cases, traditional techniques to perform an anastomosis following gastrointestinal resections lead to successful healing. However, despite focused research in the field, in certain high-risk situations leakage rates remain almost unchanged. Here, additional techniques may help the surgeon to protect the anastomosis and prevent leakage. We give an overview of some of the latest developments on experimental and clinical techniques for induction of anastomotic healing.

METHODS

We performed a review of the current literature on approaches to improve anastomotic healing.

RESULTS

Many promising approaches with a high clinical potential are in the developmental pipeline. Highly experimental approaches like inhibition of matrix metalloproteinases, stem cell therapy, hyperbaric oxygen therapy, induction of the hypoxic adaptive response, and the administration of growth factors are still in the preclinical phase. Other more clinical developments aim to strengthen the anastomotic suture line mechanically while shielding it from the influence of the microbiome. Among them are gluing, seaming the staple line, attachment of laminar biomaterials, and temporary intraluminal tubes. In addition, individualized bowel preparation, selectively reducing certain detrimental microbial populations could become the next stage of bowel preparation. Compression anastomoses are evolving as an equivalent technique additional to established hand-sewn and stapled anastomoses. Fluorescence angiography and flexible endoscopy could complement intraoperative quality control additionally to the air leak tests. Virtual ileostomy is a concept to prepare the bowel for the easy formation of a stoma in case of leakage.

CONCLUSION

A variety of promising diagnostic and prophylactic measures that may support the surgeon in identifying high-risk anastomoses and support them according to their potential deficits is currently in development.

How to Prevent Anastomotic Leak in Colorectal Surgery? A Systematic Review

Anastomosis leakage (AL) after colorectal surgery is an embarrassing problem. It is associated with poor consequence. This review aims to summarize published evidence on prevention of AL after colorectal surgery and provide recommendations according to the Oxford Centre for Evidence-Based Medicine. We conducted bibliographic research on January 15, 2020, of PubMed, Cochrane Library, Embase, Scopus, and Google Scholar. We retained meta-analysis, reviews, and randomized clinical trials. We concluded that mechanical bowel preparation did not reduce AL. It seems that oral antibiotic or oral antibiotic with mechanical bowel preparation could reduce the risk of AL. The surgical approach did not affect the AL rate. The low ligation of the inferior mesenteric artery could reduce the AL rate. The mechanical anastomosis is superior to handsewn anastomosis only in case of right colectomies, with similar results in rectal surgery between the 2 anastomosis techniques. In the case of right colectomies, this anastomosis could be performed intracorporeally or extracorporeally with similar outcomes. The air leak test did not reduce AL. There is no interest of external drainage in colonic surgery but drains reduced the rate of AL and rate of reoperation after low anterior resection. The transanal tube reduced the rate of AL.