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

Large Bowel Obstruction: Etiologies, Diagnosis, and Management

Large bowel obstructions (LBOs) often require urgent surgical intervention. Diagnosis relies on astute history and physical examination, as well as imaging with computed tomography (CT) scan for stable patients. Because of the high mortality associated with colonic perforation in patients with LBOs, decisive surgical decision-making is needed for optimal outcomes. This review seeks to provide an overview of the etiologies of LBO, diagnosis, and general management principles, as well as specific management for the most common etiologies, including colorectal cancer and strictures.

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.

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.

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.

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.

Risk Factors and Preventive Measures for Anastomotic Leak in Colorectal Cancer

Anastomotic leak (AL) represents one of the most detrimental complications after colorectal surgery. The patient-related factors and surgery-related factors leading to AL have been identified in previous studies. Through early identification and timely adjustment of risk factors, preventive measures can be taken to reduce potential AL. However, there are still many problems associated with AL. The debate about preventive measures such as preoperative mechanical bowel preparation (MBP), intraoperative drainage, and surgical scope also continues. Recently, the gut microbiota has received more attention due to its important role in various diseases. Although the underlying mechanisms of gut microbiota on AL have not been validated completely, new strategies that manipulate intrinsic mechanisms are expected to prevent and treat AL. Moreover, laboratory examinations for AL prediction and methods for blood perfusion assessment are likely to be promoted in clinical practice. This review outlines possible risk factors for AL and suggests some preventive measures in terms of patient, surgery, and gut microbiota.

Anastomotic Troubleshooting

Anastomotic leak remains a critical and feared complication in colorectal surgery. The development of a leak can be catastrophic for a patient, resulting in overall increased morbidity and mortality. To help mitigate this risk, there are several ways to assess and potentially validate the integrity of a new anastomosis to give the patient the best chance of avoiding this postoperative complication. A majority of anastomoses will appear intact with no obvious sign of anastomotic dehiscence on gross examination. However, each anastomosis should be interrogated before the conclusion of an operation. The most common method to assess for an anastomotic leak is the air leak test (ALT). The ALT is a safe intraoperative method utilized to test the integrity of left-sided colon and rectal anastomoses and most importantly allows the ability to repair a failed test before concluding the operation. Additional troubleshooting is sometimes needed due to technical difficulties with the circular stapler. Problems, such as incomplete doughnuts and stapler misfiring, do occur and each surgeon should be prepared to address them.

Volume of saline (0.9% NaCl) solution required to reach maximum peristaltic pressure in cadaveric intact jejunal specimens from dogs of various sizes

OBJECTIVE

To compare the volume of saline (0.9% NaCl) solution required to reach a maximum intraluminal peristaltic pressure of 25 mm Hg in dogs of various sizes.

SAMPLES

25 grossly normal jejunal segments from 6 canine cadavers < 20 kg (small dogs) and 25 segments from 5 cadavers ≥ 20 kg (large dogs).

PROCEDURES

Jejunal specimens were obtained within 1.5 hours after euthanasia. Harvested tissue was transected into 12-cm-long segments, mesentery was trimmed, and each segment was measured from the antimesenteric to mesenteric serosal edges. A 10-cm segment was isolated with Doyen forceps, securing a pressure sleeve within the lumen. Intraluminal saline was infused, and the volume was recorded when a pressure of > 25 mm Hg was achieved. Data were analyzed only from specimens in which the pressure remained between 24 and 26 mm Hg for > 5 seconds.

RESULTS

Mean ± SD intestinal measurement for large dogs (17.82 ± 1.44 mm) was greater than that for small dogs (12.38 ± 1.38 mm) as was the volume of saline solution infused (17.56 ± 7.17 mL vs 3.28 ± 1.41 mL, respectively). The volume infused increased by 1.31 mL (95% CI, 1.08 to 1.18) for every 1-mm increase in intestinal measurement and by 1.06 mL (95% CI, 1.052 to 1.068) for every 1-kg increase in body weight.

CONCLUSIONS AND CLINICAL RELEVANCE

The volume of saline solution used for intestinal leak testing should be determined on the basis of patient intestinal measurement or body weight. In vivo studies are necessary to establish the optimal volume for intestinal leak testing.

Intraoperative surgeon probe inspection compared to leak testing for detecting gaps in canine jejunal continuous anastomoses: A cadaveric study

OBJECTIVE

To compare the detection of gaps in jejunal continuous anastomoses by probing (PT) versus leak testing (LT).

STUDY DESIGN

Experimental study.

ANIMALS

Normal jejunal segments (n = 24) from two fresh canine cadavers.

METHODS

Intestinal segments were randomly selected by four volunteers who created six simple continuous anastomoses: two constructs using standard technique with 2-3 mm suture spacing (ST, 8 total), and four constructs with one 4-mm gap (IG, 16 total). All 24 anastomoses were examined with PT (1 volunteer) prior to LT (3 volunteers). LT was performed within a maximal peristaltic pressure range (34-54 cmH₂ O). The presence and location of anastomotic leaks (L_A ) detected with LT were compared with gaps detected with PT.

RESULTS

Nineteen out of twenty-four (79.2%) samples had at least one probe drop, and four out of twenty-three (17.4%) samples leaked. LT results from one sample were excluded due to iatrogenic suture failure. PT was 100% sensitive (95% CI: 51.01, 100%) with a 100% negative predictive value (95% CI: 56.55, 100%) at detecting gaps compared with LT. The location of all L_A was accurately identified with PT and confirmed during LT.

CONCLUSION

PT was highly sensitive at detecting gaps compared with LT. All L_A were accurately detected by PT. None of the segments negative during PT leaked.

CLINICAL SIGNIFICANCE

The diagnostic value of PT appears adequate to recognize gaps in cadaveric small intestinal anastomoses. PT offers surgeons an alternative to detect suture gaps that may contribute to postoperative dehiscence of intestinal anastomoses.

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

BACKGROUND

The aim of this study was to report our experience in the management of complications after laparoscopic left hemicolectomy (LLH) after the incorporation in our clinical practice of intraoperative indocyanine green (ICG) fluorescence angiography (FA).

METHODS

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

RESULTS

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

CONCLUSIONS

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

Experimental Study of Mechanical Integrity Testing in Stapled Large Bowel: Methylene Blue Leak Test Is Not Inferior to Air Leak Test

BACKGROUND/OBJECTIVES

Anastomotic leakage remains the most devastating postoperative complication in colorectal surgery. The mechanical integrity of the newly formed colorectal anastomosis can be evaluated by visual inspection intraoperatively; both air leak and liquid leak tests are also used to evaluate the integrity of stapled colorectal anastomoses. It is not clear whether double-stapled anastomoses are more prone to leaks than single-stapled anastomoses. The aim of our study was to compare the methylene blue and the air leak test in the experimental setting of single-stapled and double-stapled porcine bowels.

METHODS

Twenty-four distal colons were excised from slaughtered pigs without delay. The proximal bowel end was closed with a linear stapler using blue cartridges. The bowels were randomly divided into single-stapled or double-stapled groups. Air leak and methylene blue leak tests were performed. A digital pressure monitor with a gradual pressure increase function was used to both gradually increase pressure within the bowel and to determine the pressure at which the stapler line disintegrated.

RESULTS

Air leakage occurred at a mean pressure of 51.62 (±16.60) mm Hg and methylene blue leakage occurred at 46.54 (±16.78) mm Hg (p = 0.31). The air and methylene blue leaks occurred at comparable pressures in single-stapled bowels and in double-stapled bowels (47.21 [±14.02] mm Hg vs. 50.96 [±19.15] mm Hg, p = 0.6).

CONCLUSIONS

The methylene blue solution leak test is not inferior to the air leak test. There is no significant difference in bursting pressure between single-stapled and double-stapled anastomoses.

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.

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.

Predictive Risk Factors for Postoperative Complications and Its Impact on Survival in Laparoscopic Resection for Colon Cancer

BACKGROUND

Laparoscopic resection is the ideal treatment of colon cancer. The aim of the study was to analyze the predictive factors for postoperative complications and their impact on oncologic outcomes in laparoscopic resections in colon cancer.

MATERIALS AND METHODS

In all patients undergoing elective laparoscopic surgery the number and degree of severity of postoperative complications were recorded and classified according to Clavien-Dindo. A univariate analysis was made of the demographic, surgical, and oncologic variables of patients with and without complications. The statistically significant variables were then entered into a multivariate model. In both groups overall and disease-free survival were analyzed using Kaplan-Meier estimates.

RESULTS

Of 524 patients, 138 (26.3%) experienced some type of complication, 110 less severe (79.7%) and 28 (20.4%) severe. Twenty-nine conversions to open surgery occurred (5.5%) and hospital mortality was 0.2%.In the multivariate analysis, use of corticosteroids [odds ratio (OR): 3.619], oral anticoagulants (OR: 3.49), blood transfusions (OR: 4.30), and conversion to open surgery (OR: 3.93) were significantly associated with the development of complications. However, sigmoid resections were associated with fewer complications (OR: 0.45).Overall 5-year and 10-year survival in both groups, was 83.3%, 74.1%, 76.0%, and 67.1%, respectively (P=0.18). Disease-free survival at 5 and 10 years, excluding stage IV tumors, was 88.6% and 90.4%, respectively (P=0.881).

CONCLUSIONS

The use of corticosteroids, oral anticoagulants, blood transfusions, and conversion to open surgery are all independent predictive factors of postoperative complications. Sigmoid resections are associated with fewer complications. In laparoscopic resections of the colon, complications do not negatively affect long-term oncologic outcomes.

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.

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.

Intraoperative testing of colorectal anastomosis and the incidence of anastomotic leak: A meta-analysis

BACKGROUND

AL remains one of the most threatening complications in colorectal surgery. Significant efforts are put to understand the pathophysiological mechanisms involved in the development of leakage and to create the strategies to prevent it. We aimed to determine whether intraoperative testing of mechanical integrity and perfusion of colorectal anastomosis could reduce the incidence of AL.

METHODS

A systematic review and meta-analysis of papers published before November 2019 on PubMed, Scopus, Web of Science, and Cochrane Library databases and comparing intraoperative testing of the colorectal anastomosis with standard care were conducted. Odds ratios (ORs) and 95% confidence interval (CIs) were used to assess the association between intraoperative testing and AL.

RESULTS

A total of 23 studies totaling 7115 patients were included. Pooled analysis revealed intraoperative tests, for integrity (OR 0.52, 95% CI 0.34-0.82, P < .001) and perfusion (OR 0.40, 95% CI 0.22-0.752, P < .001) of the lower gastrointestinal tract anastomoses are associated with significantly lower AL rate.

CONCLUSIONS

Intraoperative testing for either integrity or perfusion of anastomoses both reduce the AL rate. Studies looking at the combination of these two testing methods of anastomosis, especially intraoperative endoscopy, and indocyanine green fluorescence angiography may be very promising to further reduction of the AL.

Clinical and economic burden of colorectal and bariatric anastomotic leaks

BACKGROUND

Anastomotic leaks cause a significant clinical and economic burden on patients undergoing bariatric and colorectal surgeries. Current literature shows a wide variation in incidence of anastomotic leaks and a significant gap in associated economic metrics. This analysis utilized claims data to quantify the full episode-of-care cost burden of leaks following colorectal and bariatric surgeries.

METHODS

Medicare Fee-for-Service and commercial claims data from a large U.S.-based health plan were queried for cost and utilization of members that underwent bariatric and colorectal surgical procedures between January 1, 2013 and August 31, 2015. Outcomes were collected for members with anastomotic leaks versus those without leaks during the initial hospital stay (index) and within 30 days of the procedure. These outcomes included leak frequency, payer reimbursement, and length of stay (LOS).

RESULTS

The colorectal Medicare analysis identified 239,350 patients undergoing colorectal surgery. For patients with a leak compared to those without, index admission costs were $30,670 greater ($48,982 vs. $18,312; p < 0.0001) and the index LOS was 12 days longer (19 vs. 7 days; p < 0.0001). This finding was similar for the bariatric patients (n = 62,292) where cost was $30,885 higher ($43,918 vs. $13,033; p < 0.0001) and LOS was 15 days longer (17 vs. 2 days; p < 0.0001). Furthermore, readmissions and associated costs were also substantially higher for those with an index leak. The commercial analysis of both the bariatric and colorectal populations trended similarly to the Medicare population in regards to all outcomes measured.

CONCLUSION

Patients experiencing anastomotic leaks during and after bariatric and colorectal surgery have significantly higher costs and longer LOS both at the initial stay and within 30 days of the procedure. It is important that providers and hospitals understand the economic consequences of these procedures and implement technologies and techniques to prevent/reduce anastomotic leaks.

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.

Does intra-operative flexible endoscopy reduce anastomotic complications following left-sided colonic resections? A systematic review and meta-analysis

AIM

Postoperative anastomotic leakage (AL) or bleeding (AB) significantly impacts on patient outcome following colorectal resection. To minimize such complications, surgeons can utilize different techniques perioperatively to assess anastomotic integrity. We aim to assess published anastomotic complication rates following left-sided colonic resection, comparing the use of intra-operative flexible endoscopy (FE) against conventional tests used to assess anastomotic integrity.

METHODS

PubMed/MEDLINE and Embase online databases were searched for non-randomized and randomized case-control studies that investigated postoperative AL and/or AB rates in left-sided colonic resections, comparing intra-operative FE against conventional tests. Data from eligible studies were pooled, and a meta-analysis using Review Manager 5.3 software was performed to assess for differences in AL and AB rates.

RESULTS

Data from six studies were analysed to assess the impact of FE on postoperative AL and AB rates (1084 and 751 patients respectively). Use of FE was associated with reduced postoperative AL and AB rates, from 6.9% to 3.5% and 5.8% to 2.4% respectively. Odds ratios favoured intra-operative FE: 0.37 (95% CI 0.21-0.68, P = 0.001) for AL and 0.35 (95% CI 0.15-0.82, P = 0.02) for AB.

CONCLUSION

This meta-analysis showed that the use of intra-operative FE is associated with a reduced rate of postoperative AL and AB, compared to conventional anastomotic testing methods.

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

Anastomotic leak (AL) constitutes a significant issue in colorectal surgery, and its incidence has remained stable over the last years. The use of intra-abdominal drain or the use of mechanical bowel preparation alone have been proven to be useless in preventing AL and should be abandoned. The role or oral antibiotics preparation regimens should be clarified and compared to other routes of administration, such as the intravenous route or enema. In parallel, preoperative antibiotherapy should aim at targeting collagenase-inducing pathogens, as identified by the microbiome analysis. AL can be further reduced by fluorescence angiography, which leads to significant intraoperative changes in surgical strategies. Implementation of fluorescence angiography should be encouraged. Progress made in AL comprehension and prevention might probably allow reducing the rate of diverting stoma and conduct to a revision of its indications.

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

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

A standardized use of intraoperative anastomotic testing in colorectal surgery in the new millennium: is technology taking over? A systematic review and network meta-analysis

BACKGROUND

Anastomotic leakage (AL) remains the most challenging complication following colorectal resection. There are several tests that can be used to test anastomotic integrity intraoperatively including air leak testing (ALT) and intraoperative colonoscopy (IOC). Indocyanine green (ICG) can be used to visualise blood supply to the bowel used in the anastomosis. However, there is no consensus internationally regarding routine use and which technique is superior. The aim of this study was to determine which intraoperative anastomotoic leak test (IALT) was most effective in reducing AL.

METHODS

A systematic review and network meta-analysis were performed. An electronic systematic search was performed using Pubmed, CENTRAL, and Web of Science, of studies comparing ALT, IOC, and ICG. The inclusion criteria were as follows: (a) patients must have had colorectal surgery with formation of an anastomosis; (b) studies must have compared one or more IALTs; (c) and studies must have clear research methodology.

RESULTS

Eleven articles totalling 3844 patients met the inclusion criteria and were included in this meta-analysis. Point estimation showed that the AL rate in the control group (no IALT) was significantly higher when compared to the ICG group (RR 0.44; Crl 0.14-0.87) and higher, but without reaching statistical significance, when compared to ALT (RR 0.53; Crl 0.21-1.30) and IOC (RR 0.49; Crl 0.10-1.80). Indirect comparison showed that the AL rate in the ICG group was lower, when compared to both ALT (RR 0.44; Crl 0.14-0.87) and IOC (RR 0.44; Crl 0.14-0.87).

CONCLUSIONS

This study suggests that intraoperative testing for a good blood supply using ICG may reduce the AL rate following colorectal surgery.