Does transanal drainage tubes placement have an impact on the incidence of anastomotic leakage after rectal cancer surgery? a systematic review and meta-analysis.

BACKGROUND: Whether Transanal drainage tubes (TDTs) placement reduces the occurrence of anastomotic leakage (AL) after rectal cancer (RC) surgery remains controversial. Most existing meta-analyses rely on retrospective studies, while the prospective studies present an inadequate level of evidence. METHODS: A systematic review and meta-analysis of prospective studies on TDTs placement in RC patients after surgery was conducted. The main analysis index was the incidence of AL, Grade B AL, and Grade C AL, while secondary analysis index was the incidence of anastomotic bleeding, incision infection, and anastomotic stenosis. A comprehensive literature search was performed utilizing the databases Cochrane Library, Embase, PubMed, and Web of Science. We recorded Risk ratios (RRs) and 95% confidence intervals (CI) for each included study, and a fixed-effect model or random-effect model was used to investigate the correlation between TDTs placement and four outcomes after RC surgery. RESULTS: Seven studies (1774 participants, TDT 890 vs non-TDT 884) were considered eligible for quantitative synthesis and meta-analysis. The meta-analysis revealed that the incidence of AL was 9.3% (83/890) in the TDT group and 10.2% (90/884) in the non-TDT group. These disparities were found to lack statistical significance (P = 0.58). A comprehensive meta-analysis, comprising four studies involving a cumulative sample size of 1259 participants, revealed no discernible disparity in the occurrence of Grade B AL or Grade C AL between the TDT group and the non-TDT group (Grade B AL: TDT 34/631 vs non-TDT 26/628, P = 0.30; Grade C AL: TDT 11/631 vs non-TDT 27/628, P = 0.30). Similarly, the incidences of anastomotic bleeding (4 studies, 876 participants), incision infection (3studies, 713 participants), and anastomotic stenosis (2studies, 561 participants) were 5.5% (24/440), 8.1% (29/360), and 2.9% (8/280), respectively, in the TDT group, and 3.0% (13/436), 6.5% (23/353), and 3.9% (11/281), respectively, in the non-TDT group. These differences were also determined to lack statistical significance (P = 0.08, P = 0.43, P = 0.48, respectively). CONCLUSION: The placement of TDTs does not significantly affect the occurrence of AL, Grade B AL, and Grade C AL following surgery for rectal cancer. Additionally, TDTs placement does not be associated with increased complications such as anastomotic bleeding, incision infection, or anastomotic stenosis. TRIAL REGISTRATION: PROSPERO: CRD42023427914.

Redefining Esophagectomy: The Manual Layered Insertion Method That May Reduce Anastomotic Leakage.

INTRODUCTION: Anastomotic leakage post-esophagectomy remains a significant challenge. Despite the use of both mechanical and manual anastomosis, leakage rates remain high. This study evaluated the effectiveness of the manual layered insertion anastomosis technique in addressing this issue. METHODS: A retrospective analysis was conducted on patients who underwent this technique from September 2020 to December 2021. The process involved thoracoscopic release of the esophagus, mediastinal lymph node dissection, laparoscopic stomach release, and its transformation into a tube. The latter was then guided to the neck for anastomosis. The posterior anastomotic wall was reshaped in the neck first for optimal insertion, followed by layered suturing with the gastric conduit. The anterior wall was subsequently sutured and repositioned into the chest. RESULTS: The study included 56 patients (51 men, five women, mean age 65.4 y), with nine having undergone neoadjuvant therapy. All received minimally invasive esophagectomy. Average intraoperative blood loss was 79.8 mL, operation time averaged 331 min, and feeding resumed after an average of 6.3 d. No anastomotic leakages were reported, with reduced incidences of anastomotic stenosis and gastric acid reflux compared to previous studies. CONCLUSIONS: The manual layered insertion anastomosis technique may reduce anastomotic leakage and associated complications, improving the efficacy of esophagectomy, which may improve postoperative results and patient quality of life, suggesting the method's potential suitability for wider clinical application.

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.

Drainage fluid LDH and neutrophil to lymphocyte ratio as biomarkers for early detecting anastomotic leakage in patients undergoing colorectal surgery.

OBJECTIVES: In this study, we investigated the role of several circulating and drainage fluid biomarkers for detecting postoperative complications (PCs) and anastomotic leakage (AL) in patients undergoing colorectal surgery. METHODS: All consecutive patients undergoing colorectal surgery between June 2018 and April 2020 were prospectively considered. On postoperative days (POD) 1, 3, and 5, we measured lactate dehydrogenase (LDH) in drainage fluid, C-reactive protein (CRP) in serum and drainage fluid, and neutrophil to lymphocyte ratio (NLR). RESULTS: We enrolled 187 patients. POD1 patients with AL had higher serum CRP levels, while on POD3 and on POD5 higher NLR and serum CRP. LDH and CRP in drainage fluid were also significantly higher at both time points. The area under the curves (AUCs) of serum and drainage fluid CRP were 0.752 (0.629-0.875) and 0.752 (0.565-0.939), respectively. The best cut-off for serum and drainage fluid CRP was 185.23 and 76 mg/dL, respectively. The AUC of NLR on POD3 was 0.762 (0.662-0.882) with a sensitivity and specificity of 84 and 63 %, respectively, at a cut-off of 6,6. Finally, drainage fluid LDH showed the best diagnostic performance for AL, with an AUC, sensitivity, and specificity of 0.921 (0.849-0.993), 82 %, and 90 % at a cut-off of 2,186 U/L. Trends in serum parameters between patients with or without PCs or AL were also evaluated. Interestingly, we found that NLR decreased faster in patients without PCs than in patients with PCs and patients with AL. CONCLUSIONS: Drainage fluid LDH and NLR could be promising biomarkers of PCs and AL.

Meta-analysis: loop ileostomy versus colostomy to prevent complications of anterior resection for rectal cancer.

PURPOSE: Anastomotic leakage is a serious complication of colorectal cancer surgery, prolonging hospital stays and impacting patient prognosis. Preventive colostomy is required in patients at risk of anastomotic fistulas. However, it remains unclear whether the commonly used loop colostomy(LC) or loop ileostomy(LI) can reduce the complications of colorectal surgery. This study aims to compare perioperative morbidities associated with LC and LI following anterior rectal cancer resection, including LC and LI reversal. METHODS: In this meta-analysis, the Embase, Web of Science, Scopus, PubMed, and Cochrane Library databases were searched for prospective cohort studies, retrospective cohort studies, and randomized controlled trials (RCTs) on perioperative morbidity during stoma development and reversal up to July 2023, The meta-analysis included 10 trials with 2036 individuals (2 RCTs and 8 cohorts). RESULTS: No significant differences in morbidity, mortality, or stoma-related issues were found between the LI and LC groups after anterior resection surgery. However, patients in the LC group exhibited higher rates of stoma prolapse (RR: 0.39; 95%CI: 0.19-0.82; P = 0.01), retraction (RR: 0.45; 95%CI: 0.29-0.71; P < 0.01), surgical site infection (RR: 0.52; 95%CI: 0.27-1.00; P = 0.05) and incisional hernias (RR: 0.53; 95%CI: 0.32-0.89; P = 0.02) after stoma closure compared to those in the LI group. Conversely, the LI group showed higher rates of dehydration or electrolyte imbalances(RR: 2.98; 95%CI: 1.51-5.89; P < 0.01), high-output(RR: 6.17; 95%CI: 1.24-30.64; P = 0.03), and renal insufficiency post-surgery(RR: 2.51; 95%CI: 1.01-6.27; P = 0.05). CONCLUSION: Our study strongly recommends a preventive LI for anterior resection due to rectal cancer. However, ileostomy is more likely to result in dehydration, renal insufficiency, and intestinal obstruction. More multicenter RCTs are needed to corroborate this.

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

INTRODUCTION: Anastomotic stenosis (AS) is a common complication after colorectal resection. However, the predisposing factors for stricture formation are not fully understood. Previous studies have shown anastomotic leakage (AL) to be a risk factor for the occurrence of AS. Therefore, we aim to investigate the impact of anastomotic leakage characteristics on the occurrence of anastomotic stenosis after colorectal resection. METHODS: Consecutive patients with AL following elective, sphincter preserving, colorectal resection, with or without diversion ostomy, between January 2009 and March 2023 were identified from a prospectively collected database. The characteristics of the anastomotic leakage, patient baseline and operative characteristics as well as the postoperative outcomes were analyzed using univariate and multivariate logistic regression to identify factors associated with the occurrence of post-leakage AS. RESULTS: A total of 129 patients developed AL and met the inclusion criteria. Among these, 28 (21.7%) patients were diagnosed with post-leakage AS. There was a significantly higher frequency of patients with neoadjuvant radiotherapy (18% vs 3%; p = .026) and hand-sewn anastomoses (39% vs 17%; p = .011) within the AS group. Furthermore, the extent of the anastomotic defect was significantly higher in the AS group compared with the non-AS group (50%, IQR 27-71 vs. 20%, IQR 9-40, p = 0.011). Similar findings were observed between the study groups regarding age, sex, BMI, ASA score, medical comorbidities, diagnosis, surgical procedure, surgical approach (open vs. minimally invasive), and anastomotic fashioning (side-to-end vs. end-to-end). On multivariate analysis, the extent of the anastomotic defect (OR 1.01; 95% CI 1.00-1.03; p = 0.034) and hand-sewn anastomoses (OR 2.68; 95% CI 1.01-6.98; p = 0.043) were confirmed as independent risk factors for post-leakage AS. No correlation could be observed between the occurrence of post-leakage AS and the ISREC grading of AL, the anastomotic height or the management of AL. Time to ostomy reversal was significantly longer in the AS group (202d, IQR 169-275 vs. 318d IQR 192-416, p = 0.014). CONCLUSION: The extent of the anastomotic defect and hand-sewn anastomoses were confirmed as independent risk factors for the occurrence of post-leakage AS. No correlation could be observed between the ISREC grading of AL, the anastomotic height or AL management, and the occurrence of post-leakage AS.

Minor impact of anastomotic leakage in anterior resection for rectal cancer on long-term male urinary and sexual function.

PURPOSE: Anastomotic leakage after anterior resection for rectal cancer induces bowel dysfunction, but the influence on urinary and sexual function is largely unknown. This cross-sectional cohort study evaluated long-term effect of anastomotic leakage on urinary and sexual function in male patients. METHODS: Patients operated with anterior resection for rectal cancer in 15 Swedish hospitals 2007-2013 were identified. Anastomotic leakage and other clinical variables were retrieved from the Swedish Colorectal Cancer Registry and medical records. Urinary and sexual dysfunction were evaluated at 4 to 11 years after surgery using the International Prostate Symptom Score, International Index of Erectile Function, and European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire CR29. The effect of anastomotic leakage on average scores of urinary and sexual dysfunction was evaluated as a primary outcome, and the single items permanent urinary catheter and sexual inactivity as secondary outcomes. The association of anastomotic leakage and functional outcomes was analyzed using regression models with adjustment for confounders. RESULTS: After a median follow-up of 84 months (interquartile range: 67-110), 379 out of 864 eligible men were included. Fifty-nine (16%) patients had anastomotic leakage. Urinary incontinence was more common in the leakage group, with an adjusted mean score difference measured by EORTC QLQ ColoRectal-29 of 8.69 (95% confidence interval: 0.72-16.67). The higher risks of urinary frequency, permanent urinary catheter, and sexual inactivity did not reach significance. CONCLUSION: Anastomotic leakage after anterior resection had a minor negative impact on urinary and sexual function in men.

Remote ischemic preconditioning versus sham-control for prevention of anastomotic leakage after resection for rectal cancer (RIPAL trial): a pilot randomized controlled, triple-blinded monocenter trial.

PURPOSE: Remote ischemic preconditioning (RIPC) reportedly reduces ischemia‒reperfusion injury (IRI) in various organ systems. In addition to tension and technical factors, ischemia is a common cause of anastomotic leakage (AL) after rectal resection. The aim of this pilot study was to investigate the potentially protective effect of RIPC on anastomotic healing and to determine the effect size to facilitate the development of a subsequent confirmatory trial. MATERIALS AND METHODS: Fifty-four patients with rectal cancer (RC) who underwent anterior resection were enrolled in this prospectively registered (DRKS0001894) pilot randomized controlled triple-blinded monocenter trial at the Department of Surgery, University Medicine Mannheim, Mannheim, Germany, between 10/12/2019 and 19/06/2022. The primary endpoint was AL within 30 days after surgery. The secondary endpoints were perioperative morbidity and mortality, reintervention, hospital stay, readmission and biomarkers of ischemia‒reperfusion injury (vascular endothelial growth factor, VEGF) and cell death (high mobility group box 1 protein, HMGB1). RIPC was induced through three 10-min cycles of alternating ischemia and reperfusion to the upper extremity. RESULTS: Of the 207 patients assessed, 153 were excluded, leaving 54 patients to be randomized to the RIPC or the sham-RIPC arm (27 each per arm). The mean age was 61 years, and the majority of patients were male (37:17 (68.5:31.5%)). Most of the patients underwent surgery after neoadjuvant therapy (29/54 (53.7%)) for adenocarcinoma (52/54 (96.3%)). The primary endpoint, AL, occurred almost equally frequently in both arms (RIPC arm: 4/25 (16%), sham arm: 4/26 (15.4%), p = 1.000). The secondary outcomes were comparable except for a greater rate of reintervention in the sham arm (9 (6-12) vs. 3 (1-5), p = 0.034). The median duration of endoscopic vacuum therapy was shorter in the RIPC arm (10.5 (10-11) vs. 38 (24-39) days, p = 0.083), although the difference was not statistically significant. CONCLUSION: A clinically relevant protective effect of RIPC on anastomotic healing after rectal resection cannot be assumed on the basis of these data.

Bowel preparation for elective colorectal resection: multi-treatment machine learning analysis on 6241 cases from a prospective Italian cohort.

BACKGROUND: Current evidence concerning bowel preparation before elective colorectal surgery is still controversial. This study aimed to compare the incidence of anastomotic leakage (AL), surgical site infections (SSIs), and overall morbidity (any adverse event, OM) after elective colorectal surgery using four different types of bowel preparation. METHODS: A prospective database gathered among 78 Italian surgical centers in two prospective studies, including 6241 patients who underwent elective colorectal resection with anastomosis for malignant or benign disease, was re-analyzed through a multi-treatment machine-learning model considering no bowel preparation (NBP; No. = 3742; 60.0%) as the reference treatment arm, compared to oral antibiotics alone (oA; No. = 406; 6.5%), mechanical bowel preparation alone (MBP; No. = 1486; 23.8%), or in combination with oAB (MoABP; No. = 607; 9.7%). Twenty covariates related to biometric data, surgical procedures, perioperative management, and hospital/center data potentially affecting outcomes were included and balanced into the model. The primary endpoints were AL, SSIs, and OM. All the results were reported as odds ratio (OR) with 95% confidence intervals (95% CI). RESULTS: Compared to NBP, MBP showed significantly higher AL risk (OR 1.82; 95% CI 1.23-2.71; p = .003) and OM risk (OR 1.38; 95% CI 1.10-1.72; p = .005), no significant differences for all the endpoints were recorded in the oA group, whereas MoABP showed a significantly reduced SSI risk (OR 0.45; 95% CI 0.25-0.79; p = .008). CONCLUSIONS: MoABP significantly reduced the SSI risk after elective colorectal surgery, therefore representing a valid alternative to NBP.

Role of visceral fat on postoperative complications and relapse in patients with Crohn's disease after ileocecal resection: Is it overrated?

INTRODUCTION: The role of visceral fat in disease development, particularly in Crohn´s disease (CD), is significant. However, its preoperative prognostic value for postoperative complications and CD relapse after ileocecal resection (ICR) remains unknown. This study aims to assess the predictive potential of preoperatively measured visceral and subcutaneous fat in postoperative complications and CD recurrence using magnetic resonance imaging (MRI). The primary endpoint was postoperative anastomotic leakage of the ileocolonic anastomosis, with secondary endpoints evaluating postoperative complications according to the Clavien Dindo classification and CD recurrence at the anastomosis. METHODS: We conducted a retrospective analysis of 347 CD patients who underwent ICR at our tertiary referral center between 2010 and 2020. We included 223 patients with high-quality preoperative MRI scans, recording demographics, postoperative outcomes, and CD recurrence rates at the anastomosis. To assess adipose tissue distribution, we measured total fat area (TFA), visceral fat area (VFA), subcutaneous fat area (SFA), and abdominal circumference (AC) at the lumbar 3 (L3) level using MRI cross-sectional images. Ratios of these values were calculated. RESULTS: None of the radiological variables showed an association with anastomotic leakage (TFA p = 0.932, VFA p = 0.982, SFA p = 0.951, SFA/TFA p = 0.422, VFA/TFA p = 0.422), postoperative complications, or CD recurrence (TFA p = 0.264, VFA p = 0.916, SFA p = 0.103, SFA/TFA p = 0.059, VFA/TFA p = 0.059). CONCLUSIONS: Radiological visceral obesity variables were associated with postoperative outcomes or clinical recurrence in CD patients undergoing ICR. Preoperative measurement of visceral fat measurement is not specific for predicting postoperative complications or CD relapse.

Impact of hyperoxia on the gut during critical illnesses.

Molecular oxygen is typically delivered to patients via oxygen inhalation or extracorporeal membrane oxygenation (ECMO), potentially resulting in systemic hyperoxia from liberal oxygen inhalation or localized hyperoxia in the lower body from peripheral venoarterial (VA) ECMO. Consequently, this exposes the gastrointestinal tract to excessive oxygen levels. Hyperoxia can trigger organ damage due to the overproduction of reactive oxygen species and is associated with increased mortality. The gut and gut microbiome play pivotal roles in critical illnesses and even small variations in oxygen levels can have a dramatic influence on the physiology and ecology of gut microbes. Here, we reviewed the emerging preclinical evidence which highlights how excessive inhaled oxygen can provoke diffuse villous damage, barrier dysfunction in the gut, and gut dysbiosis. The hallmark of this dysbiosis includes the expansion of oxygen-tolerant pathogens (e.g., Enterobacteriaceae) and the depletion of beneficial oxygen-intolerant microbes (e.g., Muribaculaceae). Furthermore, we discussed potential impact of oxygen on the gut in various underlying critical illnesses involving inspiratory oxygen and peripheral VA-ECMO. Currently, the available findings in this area are somewhat controversial, and a consensus has not yet to be reached. It appears that targeting near-physiological oxygenation levels may offer a means to avoid hyperoxia-induced gut injury and hypoxia-induced mesenteric ischemia. However, the optimal oxygenation target may vary depending on special clinical conditions, including acute hypoxia in adults and neonates, as well as particular patients undergoing gastrointestinal surgery or VA-ECMO support. Last, we outlined the current challenges and the need for future studies in this area. Insights into this vital ongoing research can assist clinicians in optimizing oxygenation for critically ill patients.

Stenosis of the colorectal anastomosis after surgery for diverticulitis: A national retrospective cohort study.

AIM: The aim of this work was to investigate the association between early postoperative anastomotic leakage or pelvic abscess (AL/PA) and symptomatic anastomotic stenosis (SAS) in patients after surgery for left colonic diverticulitis. METHOD: This is a retrospective study based on a national cohort of diverticulitis surgery patients carried out by the Association Française de Chirurgie. The assessment was performed using path analyses. The database included 7053 patients operated on for colonic diverticulitis, with surgery performed electively or in an emergency, by open access or laparoscopically. Patients were excluded from the study analysis where there was (i) right-sided diverticulitis (the initial database included all consecutive patients operated on for colonic diverticulitis), (ii) no anastomosis was performed during the first procedure or (iii) missing information about stenosis, postoperative abscess or anastomotic leakage. RESULTS: Of the 4441 patients who were included in the final analysis, AL/PA occurred in 327 (4.6%) and SAS occurred in 82 (1.8%). AL/PA was a significant independent factor associated with a risk for occurrence of SAS (OR = 3.41, 95% CI = 1.75-6.66), as was the case for diverting stoma for ≥100 days (OR = 2.77, 95% CI = 1.32-5.82), while central vessel ligation proximal to the inferior mesenteric artery was associated with a reduced risk (OR = 0.41; 95% CI = 0.19-0.88). Diverting stoma created for <100 days or ≥100 days was also a factor associated with a risk for AL/PA (OR = 3.08, 95% CI = 2-4.75 and OR = 12.95, 95% CI = 9.11-18.50). Interestingly, no significant association between radiological drainage or surgical management of AL/PA and SAS could be highlighted. CONCLUSION: AL/PA was an independent factor associated with the risk for SAS. The treatment of AL/PA was not associated with the occurrence of anastomotic stenosis. Diverting stoma was associated with an increased risk of both AL/PA and SAS, especially if it was left for ≥100 days. Physicians must be aware of this information in order to decide on the best course of action when creating a stoma during elective or emergency surgery.

SafeHeal Colovac Colorectal Anastomosis Protection Device evaluation (SAFE-2) pivotal study: an international randomized controlled study to evaluate the safety and effectiveness of the Colovac Colorectal Anastomosis Protection Device.

AIM: Although proximal faecal diversion is standard of care to protect patients with high-risk colorectal anastomoses against septic complications of anastomotic leakage, it is associated with significant morbidity. The Colovac device (CD) is an intraluminal bypass device intended to avoid stoma creation in patients undergoing low anterior resection. A preliminary study (SAFE-1) completed in three European centres demonstrated 100% protection of colorectal anastomoses in 15 patients, as evidenced by the absence of faeces below the CD. This phase III trial (SAFE-2) aims to evaluate the safety and effectiveness of the CD in a larger cohort of patients undergoing curative rectal cancer resection. METHODS: SAFE-2 is a pivotal, multicentre, prospective, open-label, randomized, controlled trial. Patients will be randomized in a 1:1 ratio to either the CD arm or the diverting loop ileostomy arm, with a recruitment target of 342 patients. The co-primary endpoints are the occurrence of major postoperative complications within 12 months of index surgery and the effectiveness of the CD in reducing stoma creation rates. Data regarding quality of life and patient's acceptance and tolerance of the device will be collected. DISCUSSION: SAFE-2 is a multicentre randomized, control trial assessing the efficacy and the safety of the CD in protecting low colorectal anastomoses created during oncological resection relative to standard diverting loop ileostomy. TRIAL REGISTRATION: NCT05010850.

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

AIM: Several papers have shown that use of indocyanine green (ICG) decreases incidence of anastomotic leakage (AL) during colonic surgery, but no clear evidence has been found for rectal cancer surgery. Therefore, with this systematic review and meta-analysis of randomized controlled trials (RCTs) we aimed to assess if ICG could also reduce risk of AL in rectal cancer surgery. METHOD: PubMed, Scopus, CINAHL and Cochrane databases were searched for RCTs assessing the effect of intraoperative ICG on the incidence of AL of the colorectal anastomosis. Pooled relative risk (RR) and pooled risk difference (RD) were obtained using models with random effects. Risk of bias was evaluated with the Rob2 tool and the quality of evidence was assessed using the GRADE Pro tool. RESULTS: Four RCTs were included for analysis, with a total of 1510 patients (743 controls and 767 ICG patients). The rate of AL was 9% in the ICG group (69/767) and 13.9% (103/743) in the control group (p = 0.003, RR -0.5, 95% CI -0.827 to -0.172, heterogeneity test 0%, p = 0.460). The RD in terms of incidence of AL was significantly decreased by 4.51% (p = 0.031, 95% CI -0.086 to -0.004, heterogeneity test 28%, p = 0.182) when using ICG. CONCLUSION: Our meta-analysis suggested that use of ICG during rectal cancer surgery could reduce the rate of AL.

Machine learning-based preoperative analytics for the prediction of anastomotic leakage in colorectal surgery: a swiss pilot study.

BACKGROUND: Anastomotic leakage (AL), a severe complication following colorectal surgery, arises from defects at the anastomosis site. This study evaluates the feasibility of predicting AL using machine learning (ML) algorithms based on preoperative data. METHODS: We retrospectively analyzed data including 21 predictors from patients undergoing colorectal surgery with bowel anastomosis at four Swiss hospitals. Several ML algorithms were applied for binary classification into AL or non-AL groups, utilizing a five-fold cross-validation strategy with a 90% training and 10% validation split. Additionally, a holdout test set from an external hospital was employed to assess the models' robustness in external validation. RESULTS: Among 1244 patients, 112 (9.0%) suffered from AL. The Random Forest model showed an AUC-ROC of 0.78 (SD: ± 0.01) on the internal test set, which significantly decreased to 0.60 (SD: ± 0.05) on the external holdout test set comprising 198 patients, including 7 (3.5%) with AL. Conversely, the Logistic Regression model demonstrated more consistent AUC-ROC values of 0.69 (SD: ± 0.01) on the internal set and 0.61 (SD: ± 0.05) on the external set. Accuracy measures for Random Forest were 0.82 (SD: ± 0.04) internally and 0.87 (SD: ± 0.08) externally, while Logistic Regression achieved accuracies of 0.81 (SD: ± 0.10) and 0.88 (SD: ± 0.15). F1 Scores for Random Forest moved from 0.58 (SD: ± 0.03) internally to 0.51 (SD: ± 0.03) externally, with Logistic Regression maintaining more stable scores of 0.53 (SD: ± 0.04) and 0.51 (SD: ± 0.02). CONCLUSION: In this pilot study, we evaluated ML-based prediction models for AL post-colorectal surgery and identified ten patient-related risk factors associated with AL. Highlighting the need for multicenter data, external validation, and larger sample sizes, our findings emphasize the potential of ML in enhancing surgical outcomes and inform future development of a web-based application for broader clinical use.

Efficacy of transanal drainage tube placement in preventing anastomotic leakage after ileal pouch-anal anastomosis in patients with ulcerative colitis.

BACKGROUND: Transanal drainage tube (TDT) is used to prevent anastomotic leakage after surgery for rectal cancer. However, it remains unclear whether intraoperative TDT placement is also useful in preventing anastomotic leakage after ileal pouch-anal or ileal pouch-anal canal anastomosis (IPAA) in patients with ulcerative colitis (UC). This study aimed to evaluate the efficacy of intraoperative TDT placement in preventing anastomotic leakage after IPAA in patients with UC. METHODS: Patients with UC who underwent proctectomy with IPAA in the study institution between January 2000 and December 2021 were enrolled in this retrospective cohort study. The relationship between TDT placement and anastomotic leakage was evaluated by logistic regression analysis. RESULTS: The study population included 168 patients. TDT was placed intraoperatively in 103 of the 168 patients (61.3%). The rate of anastomotic leakage was significantly lower in the TDT group than in the non-TDT group (7.8% vs 18.5%, p = 0.037). Reoperation was not needed in any patient in the TDT group whereas two reoperations were necessary in the non-TDT group (3.1%). By logistic regression analysis, intraoperative TDT placement was an independent protective factor for anastomotic leakage. CONCLUSIONS: TDT placement was significantly associated with anastomotic leakage of IPAA in patients with UC undergoing surgery. Although two-stage surgery with ileostomy is usually preferred in UC surgery, our findings suggest that TDT placement might contribute to the improvement of postoperative outcomes after UC surgery.

Real-time quantification of laser speckle contrast imaging during intestinal laparoscopic surgery: successful demonstration in a porcine intestinal ischemia model.

BACKGROUND: Anastomotic leakage (AL) is a dreaded complication following colorectal cancer surgery, impacting patient outcome and leads to increasing healthcare consumption as well as economic burden. Bowel perfusion is a significant modifiable factor for anastomotic healing and thus crucial for reducing AL. AIMS: The study aimed to calculate a cut-off value for quantified laser speckle perfusion units (LSPUs) in order to differentiate between ischemic and well-perfused tissue and to assess inter-observer reliability. METHODS: LSCI was performed using a porcine ischemic small bowel loop model with the PerfusiX-Imaging® system. An ischemic area, a well-perfused area, and watershed areas, were selected based on the LSCI colormap. Subsequently, local capillary lactate (LCL) levels were measured. A logarithmic curve estimation tested the correlation between LSPU and LCL levels. A cut-off value for LSPU and lactate was calculated, based on anatomically ischemic and well-perfused tissue. Inter-observer variability analysis was performed with 10 observers. RESULTS: Directly after ligation of the mesenteric arteries, differences in LSPU values between ischemic and well-perfused tissue were significant (p < 0.001) and increased significantly throughout all following measurements. LCL levels were significantly different (p < 0.001) at both 60 and 120 min. Logarithmic curve estimation showed an R2 value of 0.56 between LSPU and LCL values. A LSPU cut-off value was determined at 69, with a sensitivity of 0.94 and specificity of 0.87. A LCL cut-off value of 3.8 mmol/L was found, with a sensitivity and specificity of 0.97 and 1.0, respectively. There was no difference in assessment between experienced and unexperienced observers. Cohen's Kappa values were moderate to good (0.52-0.66). CONCLUSION: Real-time quantification of LSPUs may be a feasible intraoperative method to assess tissue perfusion and a cut-off value could be determined with high sensitivity and specificity. Inter-observer variability was moderate to good, irrespective of prior experience with the technique.

Anastomotic tension "Bridging": a risk factor for anastomotic leakage following low anterior resection.

BACKGROUND: Excessive tension at the anastomosis contributes to anastomotic leakage (AL) in low anterior resection (LAR). However, the specific tension has not been measured. We assessed whether "Bridging," characterized by the proximal colon resembling a suspension bridge above the pelvic floor, is a significant risk factor for AL following LAR for rectal cancer. METHODS: This retrospective study reviewed the medical records and laparoscopic videos of 102 patients who underwent laparoscopic LAR using the double stapling technique at Yachiyo Hospital between January 2014 and December 2023. Patients were classified based on whether they had Bridging (tight or sagging) or were in a Resting state of the proximal colon, and the association between Bridging and AL was examined. RESULTS: AL occurred in 31.3% of the Tight Bridging group, 20% of the Sagging Bridging group, and 2.2% of the Resting group (P = 0.002). The incidence of AL was significantly higher in patients with Bridging than in those without (23.2% vs. 2.2%, P = 0.003). Multivariate analysis revealed that Bridging is an independent risk factor for AL (odds ratio = 6.97; 95% confidence interval: 1.45-33.6; P = 0.016). CONCLUSIONS: The presence of Bridging is a significant risk factor for AL following LAR for rectal cancer, suggesting the need for implementing preventive measures in patients with this condition.

C-reactive protein-to-albumin ratio as a risk factor for anastomotic leakage after anterior resection for rectal cancer with intraoperative use of indocyanine green fluorescence imaging.

INTRODUCTION: Indocyanine green fluorescence imaging (ICG-FI) reduces anastomotic leakage (AL) in rectal cancer surgery. However, no studies investigating risk factors for anastomotic leakage specific to the group using ICG-FI have ever previously been conducted. The purpose of this retrospective multicenter study was to ascertain the risk factors for AL in the group using ICG-FI. METHODS: A total of 638 patients who underwent laparoscopic or robotic anterior resection for rectal cancer between April 2018 and March 2023 were included in this study. Patients were divided into two groups: the ICG-FI group (n = 269) and the non-ICG-FI group (n = 369) for comparative analysis. The effects of clinicopathological and treatment-related factors on AL in the ICG-FI group were evaluated using both univariate and multivariate analyses. RESULTS: The incidence of AL in the ICG-FI group was 4.8%. Although there was no significant difference in the incidence of AL between the two groups, it was observed to be lower in the ICG-FI group. A multivariate analysis revealed a preoperative C-reactive protein-to-albumin ratio (CAR) ≥ 0.049 (odds ratio, 3.73; 95% confidence interval, 1.01-13.70; p = 0.048) as an independent risk factor for AL in the ICG-FI group. CONCLUSIONS: In this study, CAR was the only identified risk factor for AL in the ICG-FI group. It was suggested that CAR could be a criterion for early surgical intervention, prior to the escalation of risks, or for considering interventions such as diverting stoma creation.

Quantification of fluorescence angiography for visceral perfusion assessment: measuring agreement between two software algorithms.

BACKGROUND: Indocyanine green fluorescence angiography (ICG-FA) may reduce perfusion-related complications of gastrointestinal anastomosis. Software implementations for quantifying ICG-FA are emerging to overcome a subjective interpretation of the technology. Comparison between quantification algorithms is needed to judge its external validity. This study aimed to measure the agreement for visceral perfusion assessment between two independently developed quantification software implementations. METHODS: This retrospective cohort analysis included standardized ICG-FA video recordings of patients who underwent esophagectomy with gastric conduit reconstruction between August 2020 until February 2022. Recordings were analyzed by two quantification software implementations: AMS and CPH. The quantitative parameter used to measure visceral perfusion was the normalized maximum slope derived from fluorescence time curves. The agreement between AMS and CPH was evaluated in a Bland-Altman analysis. The relation between the intraoperative measurement of perfusion and the incidence of anastomotic leakage was determined for both software implementations. RESULTS: Seventy pre-anastomosis ICG-FA recordings were included in the study. The Bland-Altman analysis indicated a mean relative difference of + 58.2% in the measurement of the normalized maximum slope when comparing the AMS software to CPH. The agreement between AMS and CPH deteriorated as the magnitude of the measured values increased, revealing a proportional (linear) bias (R2 = 0.512, p < 0.001). Neither the AMS nor the CPH measurements of the normalized maximum slope held a significant relationship with the occurrence of anastomotic leakage (median of 0.081 versus 0.074, p = 0.32 and 0.041 vs 0.042, p = 0.51, respectively). CONCLUSION: This is the first study to demonstrate technical differences in software implementations that can lead to discrepancies in ICG-FA quantification in human clinical cases. The possible variation among software-based quantification methods should be considered when interpreting studies that report quantitative ICG-FA parameters and derived thresholds, as there may be a limited external validity.