The problem of colorectal anastomosis safety

Intraoperative left-sided colorectal anastomotic testing in clinical practice: a multi-treatment machine-learning analysis of the iCral3 prospective cohort

BACKGROUND

Current evidence about intraoperative anastomotic testing after left-sided colorectal resections is still controversial. The aim of this study was to analyze the impact of Indocyanine Green fluorescent angiography (ICG-FA) and air-leak test (ALT) over standard assessment on anastomotic leakage (AL) rates according to surgeon's perception of anastomosis perfusion and/or integrity in clinical practice.

METHODS

A database of 2061 patients who underwent left-sided colorectal resections was selected from patients enrolled in a prospective multicenter study. It was retrospectively analyzed through a multi-treatment machine-learning model considering standard visual assessment (NW; No. = 899; 43.6%) as the reference treatment arm, compared to ICG-FA alone (WP; No. = 409; 19.8%), ALT alone (WI; No. = 420; 20.4%) or both (WPI; No. = 333; 16.2%). Twenty-four covariates potentially affecting the outcomes were included and balanced into the model within the subgroups. The primary endpoint was AL, the secondary endpoints were overall morbidity (OM), major morbidity (MM), reoperation for AL, and mortality. All the results were reported as odds ratio (OR) with 95% confidence intervals (95%CI).

RESULTS

The WPI subgroup showed significantly higher AL risk (OR 1.91; 95% CI 1.02-3.59; p 0.043), MM risk (OR 2.35; 95% CI 1.39-3.97; p 0.001), and reoperation for AL risk (OR 2.44; 95% CI 1.12-5.31; p 0.025). No other significant differences were recorded.

CONCLUSIONS

This study showed that the surgeons' perception of both anastomotic perfusion and integrity (WPI subgroup) was associated to a significantly higher risk of AL and related morbidity, notwithstanding the extensive use of both ICG-FA and ALT testing.

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.

Laparoscopic peritoneal lavage versus sigmoidectomy for perforated diverticulitis with purulent peritonitis: three-year follow-up of the randomised LOLA trial

Background

This study aimed to compare laparoscopic lavage and sigmoidectomy as treatment for perforated diverticulitis with purulent peritonitis during a 36 month follow-up of the LOLA trial.

Methods

Within the LOLA arm of the international, multicentre LADIES trial, patients with perforated diverticulitis with purulent peritonitis were randomised between laparoscopic lavage and sigmoidectomy. Outcomes were collected up to 36 months. The primary outcome of the present study was cumulative morbidity and mortality. Secondary outcomes included reoperations (including stoma reversals), stoma rates, and sigmoidectomy rates in the lavage group.

Results

Long-term follow-up was recorded in 77 of the 88 originally included patients, 39 were randomised to sigmoidectomy (51%) and 38 to laparoscopic lavage (49%). After 36 months, overall cumulative morbidity (sigmoidectomy 28/39 (72%) versus lavage 32/38 (84%), p = 0·272) and mortality (sigmoidectomy 7/39 (18%) versus lavage 6/38 (16%), p = 1·000) did not differ. The number of patients who underwent a reoperation was significantly lower for lavage compared to sigmoidectomy (sigmoidectomy 27/39 (69%) versus lavage 17/38 (45%), p = 0·039). After 36 months, patients alive with stoma in situ was lower in the lavage group (proportion calculated from the Kaplan–Meier life table, sigmoidectomy 17% vs lavage 11%, log-rank p = 0·0268). Eventually, 17 of 38 (45%) patients allocated to lavage underwent sigmoidectomy.

Conclusion

Long-term outcomes showed that laparoscopic lavage was associated with less patients who underwent reoperations and lower stoma rates in patients alive after 36 months compared to sigmoidectomy. No differences were found in terms of cumulative morbidity or mortality. Patient selection should be improved to reduce risk for short-term complications after which lavage could still be a valuable treatment option.

Graphical abstract

Imaging PPG for In Vivo Human Tissue Perfusion Assessment during Surgery

Surgical excision is the golden standard for treatment of intestinal tumors. In this surgical procedure, inadequate perfusion of the anastomosis can lead to postoperative complications, such as anastomotic leakages. Imaging photoplethysmography (iPPG) can potentially provide objective and real-time feedback of the perfusion status of tissues. This feasibility study aims to evaluate an iPPG acquisition system during intestinal surgeries to detect the perfusion levels of the microvasculature tissue bed in different perfusion conditions. This feasibility study assesses three patients that underwent resection of a portion of the small intestine. Data was acquired from fully perfused, non-perfused and anastomosis parts of the intestine during different phases of the surgical procedure. Strategies for limiting motion and noise during acquisition were implemented. iPPG perfusion maps were successfully extracted from the intestine microvasculature, demonstrating that iPPG can be successfully used for detecting perturbations and perfusion changes in intestinal tissues during surgery. This study provides proof of concept for iPPG to detect changes in organ perfusion levels.

Comprehensive testing of colorectal anastomosis: results of prospective observational cohort study

BACKGROUND

Anastomotic leakage remains one of the most threatening complications in colorectal surgery. Intraoperative testing of anastomosis may reduce the postoperative anastomotic leakage rates. This study aimed to investigate a novel comprehensive intraoperative colorectal anastomosis testing technique to detect the failure of the anastomosis construction and to reduce the risk of postoperative leak.

METHODS

This multi-centre prospective cohort pilot study included 60 patients who underwent colorectal resection with an anastomosis at or below 15 cm from the anal verge. Comprehensive trimodal testing consisted of indocyanine green fluorescence angiography, tension testing, air-leak, and methylene blue leak tests to evaluate the perfusion, tension, and mechanical integrity of the anastomosis.

RESULTS

Ten (16.7%) patients developed an anastomotic leakage. Trimodal test was positive in 16 (26.6%) patients and the operative plan was changed for all of them. Diverting ileostomy was performed in 14 (87.5%) patients. However, two (12.5%) patients still developed clinically significant anastomotic leakage (Grade B). Forty-four (73.4%) patients had a negative trimodal test, preventive ileostomy was performed in 19 (43.2%), and five (11.4%) patients had clinically significant anastomotic leakage (Grade B and C).

CONCLUSION

Trimodal testing identifies anastomoses with initial technical failure where reinforcement of anastomosis or diversion can lead to an acceptable rate of anastomotic leakage. Identification of well-performed anastomosis could allow a reduction of ileostomy rate by two-fold. However, anastomotic leakage rate remains high in technically well-performed anastomoses.

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.

Indocyanine green fluorescence angiography versus standard intraoperative methods for prevention of anastomotic leak in colorectal surgery: meta-analysis

BACKGROUND

Assessment of anastomotic blood perfusion with intraoperative indocyanine green fluorescence angiography (ICG-FA) may be effective in preventing anastomotic leak compared with standard intraoperative methods in colorectal surgery.

METHODS

MEDLINE, PubMed, Cochrane Central Register of Controlled Trials and the Cochrane Library were searched for RCTs and observational studies on intraoperative ICG-FA to May 2020. Odds ratios (ORs), risk differences and mean differences (MDs) were calculated with 95 per cent c.i. based on intention-to-treat analysis. The number needed to treat for an additional beneficial outcome was also estimated.

RESULTS

Twenty-five comparative studies included a total of 7735 patients. The use of intraoperative ICG fluorescence angiography was linked with a significant reduction in all grades anastomotic leak (OR 0.39 (95 per cent c.i. 0.31 to 0.49), P < 0.001; number needed to treat for an additional beneficial outcome (NNTB) 23) and length of hospital stay (MD -0.72 (95 per cent c.i. -1.22 to -0.21) days, P = 0.006). A significantly lower incidence of grade A (OR 0.33 (0.18 to 0.60), P < 0.001), grade B (OR 0.58 (0.35 to 0.97), P = 0.04) and grade C (OR 0.59 (0.38 to 0.92), P = 0.02) anastomotic leak was demonstrated in favour of ICG-FA. For low or ultra-low rectal resection, the odds of developing anastomotic leakage was 0.32 (0.23 to 0.45) (P < 0.001; NNTB 14). There were no differences in duration of surgery, and no adverse events related to ICG fluorescent injection.

CONCLUSION

The use of ICG-FA instead of standard intraoperative methods to assess anastomosis blood perfusion in colorectal surgery leads to a significant reduction in anastomotic leakage and in the need for surgical reintervention for anastomotic leak, especially in patients with low or ultra-low rectal resections.

Influence of intraoperative vasopressor use on indocyanine green fluorescence angiography: first evaluation in an experimental model

Intraoperative indocyanine green (ICG) fluorescence angiography has gained popularity and acceptance in many surgical fields for the real-time assessment of tissue perfusion. Although vasopressors have the potential to preclude an accurate assessment of tissue perfusion, there is a lack of literature with regards to its effect on ICG fluorescence angiography. An experimental porcine model was used to expose the small bowel for quantitative tissue perfusion assessment. Three increasing doses of norepinephrine infusion (0.1, 0.5, and 1.0 µg/kg/min) were administered intravenously over a 25-min interval. Time-to-peak fluorescence intensity (TTP) was the primary outcome. Secondary outcomes included absolute fluorescence intensity and local capillary lactate (LCL) levels. Five large pigs (mean weight: 40.3 ± 4.24 kg) were included. There was no significant difference in mean TTP (in seconds) at baseline (4.23) as compared to the second (3.90), third (4.41), fourth (4.60), and fifth ICG assessment (5.99). As a result of ICG accumulation, the mean and the maximum absolute fluorescence intensity were significantly different as compared to the baseline assessment. There was no significant difference in LCL levels (in mmol/L) at baseline (0.74) as compared to the second (0.82), third (0.64), fourth (0.60), and fifth assessment (0.62). Increasing doses of norepinephrine infusion have no significant influence on bowel perfusion using ICG fluorescence angiography.

Dynamic Serosal Perfusion Assessment during Colorectal Resection Using Visible Light Spectroscopy

INTRODUCTION

Anastomotic leakage (AL) in colorectal surgery occurs with an incidence of up to 20%. Bowel perfusion is deemed to be one of the most important factors for anastomotic healing. However, not much is known about its variability during colorectal surgery and its impact on the outcome. Therefore, this study aims to evaluate serosal oxygen saturation patterns during colorectal resections with visible light spectroscopy (VLS).

MATERIALS AND METHODS

Bowel perfusion in patients undergoing left-sided colorectal resections was assessed at different timepoints during surgery using VLS on the colonic serosa. The primary outcome parameter was serosal oxygen saturation (StO2) at the anastomosis during different timepoints of surgery.

RESULTS

We included 50 patients who underwent colorectal resection for bowel cancer (58%) and diverticular disease (34%). StO2 at the proximal site of the anastomosis increased significantly throughout the surgery (mean difference 3.61%; 95% CI -6.22 to -1.00; p = 0.008). However, aberrancy from this identified perfusion pattern had no impact on the postoperative outcome.

CONCLUSION

During colorectal resections, we could demonstrate an increase of the colonic StO2 throughout surgery. Appearance of AL was not associated with lower StO2, underlining the multifactorial genesis of developing AL.

Colorectal resection in endometriosis patients: correlation between histopathological findings and postoperative outcome

Introduction

Endometriosis is associated with a high number of chronic pelvic pain and reduced quality of life. Colorectal resections in case of bowel involvement of endometriosis are associated with an unneglectable morbidity in young and healthy patients. There is no linear correlation established between the degree of symptoms and stage of endometriosis. The aim of this study was to correlate the histological findings to preoperative pain scores in colorectal resected patients with endometriosis.

Methods

Twenty-five patients who underwent laparoscopic colorectal resection for endometriosis between 2014 and 2019 were included in this retrospective study. Pain level was assessed preoperatively and postoperatively via phone call in May 2020. Histopathology was correlated to preoperative symptoms and postoperative outcome.

Results

Average follow-up time was 38.68 months (± 19.92). Preoperative VAS-score was 8.32 (± 1.70). We observed a significant reduction of pain level in all patients after surgery (p ≤ 0.005). Pain levels were equal regarding the presence of satellite spots and various degrees of infiltration depth. The resection margins were clear in all patients. Postoperative complications occurred in 6 cases (24%) and anastomotic leakage was observed in 3 patients (12%). Average VAS-score at time of follow-up was 1.70 (± 2.54).

Conclusion

Our data demonstrate that adequate colorectal resection leads to reduction of pain and an increase of quality of life irrespective of histopathological findings. An experienced team is necessary to improve intraoperative outcome and to reduce postoperative morbidity in case of complication.

Risk factors for anastomotic leakage and its impact on long-term survival in left-sided colorectal cancer surgery

Background

Anastomotic leakage (AL) significantly impairs short-term outcomes. The impact on the long-term outcomes remains unclear. This study aimed to identify the risk factors for AL and the impact on long-term survival in patients with left-sided colorectal cancer.

Methods

Nine-hundred patients with left-sided colorectal carcinoma who underwent sigmoid or rectal resection were enrolled in the study. Risk factors for AL after sigmoid or rectal resection were identified, and long-term outcomes of patients with and without AL were compared.

Results

AL rates following sigmoid and rectal resection were 5.1% and 10.7%, respectively. Higher ASA score (III–IV; OR = 10.54, p = 0.007) was associated with AL in patients undergoing sigmoid surgery on multivariable analysis. Male sex (OR = 2.40, p = 0.004), CCI score > 5 (OR = 1.72, p = 0.025), and T3/T4 stage tumors (OR = 2.25, p = 0.017) were risk factors for AL after rectal resection on multivariable analysis. AL impaired disease-free and overall survival in patients undergoing sigmoid (p = 0.009 and p = 0.001) and rectal (p = 0.003 and p = 0.014) surgery.

Conclusion

ASA score of III–IV is an independent risk factor for AL after sigmoid surgery, and male sex, higher CCI score, and advanced T stage are risk factors for AL after rectal surgery. AL impairs the long-term survival in patients undergoing left-sided colorectal surgery.