Machine-learning based preoperative analytics for the prediction of anastomotic insufficiency in colorectal surgery: a single-centre pilot study

Background: Anastomotic insufficiency (AI) is a relatively common but grave complication after colorectal surgery. This study aims to determine whether AI can be predicted from simple preoperative data using machine learning (ML) algorithms. Methods: In this retrospective analysis, patients undergoing colorectal surgery with creation of a bowel anastomosis from the University Hospital of Basel were included. Data was split into a training set (80%) and a test set (20%). The group of patients with AI was oversampled to a ratio of 50:50 in the training set and missing values were imputed. Known predictors of AI were included as inputs: age, gender, BMI, smoking status, alcohol abuse, prior abdominal surgery, leukocytosis, haemoglobin and albumin levels, steroid use, the Charlson Comorbidity Index, the American Society of Anesthesiologists score, and renal function. Results: Of the 593 included patients, 88 experienced AI. At internal validation on unseen patients from the test set, area under the curve (AUC) was 0.64 (95% confidence interval [CI]: 0.44-0.82), calibration slope was 0.21 (95% CI: -0.02-0.46) and calibration intercept was 0.06 (95% CI: 0.01-0.1). We observed a specificity of 0.76 (95% CI: 0.68-0.84), sensitivity of 0.36 (95% CI: 0.08-0.7), and accuracy of 0.72 (95% CI: 0.65-0.8). Conclusion: By using 13 patient-related risk factors associated with AI, we demonstrate the feasibility of ML-based prediction of AI after colorectal surgery. Nevertheless, it is crucial to include multicenter data and higher sample sizes to develop a robust and generalizable model, which will subsequently allow for deployment of the algorithm in a web-based application.

Optimization of anastomotic technique and gastric conduit perfusion with hyperspectral imaging in an experimental model for minimally invasive esophagectomy

ObjectiveTo optimize anastomotic technique and gastric conduit perfusion with hyperspectral imaging (HSI) for total minimally invasive esophagectomy (MIE) with linear stapled anastomosis.Summary Background DataEsophagectomy is the mainstay of esophageal cancer treatment but anastomotic insufficiency related morbidity and mortality remain challenging for patient outcome.MethodsA live porcine model (n=50) for MIE was used with gastric conduit formation and linear stapled side-to-side esophagogastrostomy. Four main experimental groups differed in stapling length (3 vs. 6 cm) and anastomotic position on the conduit (cranial vs. caudal). Tissue oxygenation around the anastomotic site was evaluated using HSI and was validated with histopathology.ResultsThe tissue oxygenation (ΔStO2) after the anastomosis remained constant only for the short stapler in caudal position (−0.4± 4.4%, n.s.) while it dropped markedly in the other groups (short-cranial: -15.6± 11.5%, p=0.0002; long-cranial: -20.4± 7.6%, p=0.0126; long-caudal: -16.1± 9.4%, p<0.0001) Tissue samples from deoxygenated stomach as measured by HSI showed correspondent eosinophilic pre-necrotic changes in 35.7± 9.7% of the surface area.ConclusionsTissue oxygenation at the anastomotic site of the gastric conduit during MIE is influenced by stapling technique. Optimal oxygenation was achieved with a short stapler (3 cm) and sufficient distance of the anastomosis to the cranial end of the gastric conduit. HSI tissue deoxygenation corresponded to histopathologic necrotic tissue changes. These findings allow for optimization of gastric conduit perfusion and anastomotic technique in MIE.Level of EvidenceNot applicable. Translational animal science. Original article.

Comparison of robotic-assisted and open Ivor Lewis esophagectomies in 321 patients of a single center: A case-matched analysis

Objective We introduced robotic-assisted Ivor Lewis esophagectomies (rob-E) using the da Vinci Xi in Oct. 2015. Prior to that, esophagectomies were performed as open Ivor Lewis (open-E) procedures. Aim of this study is to evaluate the safety of rob-E in comparison to open-E procedures regarding perioperative outcomes. Methods Retrospective analysis of prospectively collected data between Feb. 1999 and Dec. 2020. A case-matched analysis, matching open-E to rob-E in a 1:1 manner, was conducted. Cases were matched regarding age, gender, American Society of Anesthesiologists (ASA) score, histological type of tumor, tumor location and stage. Results In the study period 321 patients underwent an esophagectomy. 76 received rob-E and 245 open-E. After matching the cases the comparison of preoperative patient and tumor characteristics revealed no differences between the rob-E and open-E group regarding age at time of operation with a median of 69.5 (35-83) respectively 70 (46-88) years (p = 0.900), gender with 84.2% male in both groups (p = 1.000), ASA score with 68.4% ASA 3 or 4 in both groups (p = 1.000), percentage of tumor stage III of 53.9% respectively 57.9% (p = 0.707), and rate of neoadjuvant treatment of 82.9% in rob-E and 81.6% in open-E (p = 1.000). Conversion from rob-E to open-E was never necessary. For rob-E versus open-E no difference was found regarding overall morbidity with 69.7% versus 60.5% (p = 0.307), major morbidity (Clavien-Dindo &gt; = 3b) with 11.8% versus 14.5% (p = 0.811), incidence of anastomotic insufficiency with 7.9% versus 5.3% (p = 0.745), rate of surgical reintervention with 5.3% versus 7.9% (p = 0.745), and mortality with 2.6% versus 3.9% (p = 1.000). Postoperative details showed no difference including a similar duration of hospitalization with a median of 20 (13-62) respectively 18.5 (13-52) days (p = 0.368) and number of harvested lymph nodes with a median of 24.5 (7-59) in rob-E and 23 (2-64) in open-E (p = 0.203). Conclusion The introduction of rob-E in our institution was safe, as perioperative morbidity and mortality did not differ from the previously performed open-E. Overall, the incidence of major morbidity and anastomotic insufficiency in rob-E and open-E show a satisfactory rate compared to previous reports in literature. Further studies with a larger cohort of rob-E are planned in order to draw more decisive conclusions.

Continuously sutured versus linear-stapled anastomosis in 76 robotic-assisted Ivor Lewis esophagectomies

Objective We introduced robotic-assisted Ivor Lewis esophagectomies (rob-E) using the da Vinci Xi in Oct. 2015. Two anastomotic techniques have been performed – continuously sutured (COSU) and linear-stapled (LIST). Aim of this study is to evaluate the two anastomotic techniques regarding perioperative outcomes in our experience. Methods Retrospective analysis of prospectively collected data between Oct. 2015 and Dec. 2020 including 76 patients. 45 underwent COSU and 31 LIST. Techniques are demonstrated with video material. Minor (Clavien-Dindo &lt; = 3a) and major (Clavien-Dindo &gt; = 3b) morbidity, rate of anastomotic insufficiency, mortality, and duration of hospitalization were compared. Results Patient characteristics were as follows: median age of 69 (35-83) years in COSU and 70 (36-83) years in LIST (p = 0.575), male gender in 84.4% of COSU and 83.9% of LIST (p = 1.000), and physical status with American Society of Anesthesiologists score 3 in 62.2% of COSU and 67.7% of LIST (p = 0.771). Concerning tumor characteristics there were 91.1% adenocarcinomas in COSU and 96.8% in LIST (p = 0.642), whereas the others were squamous cell carcinomas and one neuroendocrine tumor in COSU. The tumors were stage II in 22.2% respectively 32.3% and stage III in 57.8% respectively 48.4% of COSU and LIST (p = 0.555). Comparison of minor morbidity occurring in 60.0% of COSU and 54.8% of LIST (p = 0.813), major morbidity in 8.9% respectively 16.1% (p = 0.473), incidence of anastomotic insufficiency in 8.9% of COSU and 6.5% of LIST (p = 1.000), rate of surgical reintervention necessary in 2.2% respectively 9.7% (p = 0.298) as well as mortality of 2.2% in COSU and 3.2% in LIST (p = 1.000) showed no difference. Median duration of hospitalization of 20 (13-49) days in COSU and 20 (14-62) in LIST (p = 0.423) did not differ. Conclusion In rob-E COSU and LIST show comparable results and a preferable technique cannot be determined yet. Our results do not support the results of previous reports (Cerfolio et al.) that demonstrated a superiority of LIST. While stapling the backside of the anastomosis in LIST impresses as an elegant way to overcome the surgical demanding part of the anastomosis, other disadvantages such as compromising perfusion of the gastric conduit may prevail and limit the benefits. Further studies with a larger cohort are planned in order to draw more decisive conclusions.

Classification and evaluation of anastomotic leaks after esophageal surgery—a tertiary university experience

Summary Background Anastomotic insufficiency of the esophagus is the most feared complication of surgeons, leading to high postoperative morbidity and mortality. However, there is no internationally accepted guideline for its classification and treatment algorithm. Therefore, the aim of this study was to analyze the detection of anastomotic leaks as well as to discuss and validate the classification proposed by the Surgical Working Group on Endoscopy and Ultrasound in late 2018. Methods All patients undergoing surgery for malignancy of the esophagogastric junction between 2013 and 2020 were analyzed. Out of these patients, those diagnosed with an anastomotic insufficiency were extracted and classified according to the classification proposed by the Surgical Working Group on Endoscopy and Ultrasound. Continuous variables were expressed as medians, categorical variables were compared using Fisher’s exact test or chi-square test. Results From 2013 to 2020, all 23 patients (10.84%) who developed an anastomotic leak after esophageal surgery were included in this study. The study revealed a significant increase in median hospital stay, median intensive care unit stay, and overall mortality rate (p = 0.028) with increased classification type. Conclusion The results of this study showed that the classification proposed by the Surgical Working Group on Endoscopy and Ultrasound can be validated and that there is a clear differentiation between the subtypes. Standardized diagnosis and management improve the overall outcome of patients. Main novel aspects This article gives an introduction to classifying anastomotic insufficiencies according to the classification proposed by the Surgical Working Group on Endoscopy and Ultrasound. Results of the classification can be validated, with a clear differentiation of postoperative outcome between subtypes.

The Circular Stapled Esophagogastric Anastomosis in Esophagectomy: No Differences in Anastomotic Insufficiency and Stricture Rates Between the 25 mm and 28 mm Circular Stapler

Background For patients undergoing an Ivor Lewis esophagectomy with a circular stapled anastomosis, the optimal diameter of the used circular stapler to restore continuity is unknown. The aim of this study was to compare the 25 mm stapled versus the 28 mm stapled esophagogastric anastomosis after Ivor Lewis esophagectomy, focusing on anastomotic insufficiency and postoperative anastomotic strictures. Methods Between February 2008 and June 2019, 349 consecutive patients underwent Ivor Lewis esophagectomy with gastric conduit reconstruction and circular stapled anastomosis. Patient characteristics and postoperative results, such as anastomotic insufficiency rates, postoperative anastomotic stricture rates, time to anastomotic stricture rate, and the number of dilatations, were recorded in a prospective database and analyzed. Results In 222 patients (64%), the 25 mm circular stapler was used and in 127 patients (36%) the 28 mm circular stapler was used. There were no differences in baseline characteristics. Anastomotic insufficiency rates were comparable between the 25 mm (12%) and the 28 mm groups (11%) (p = 0.751). There were no differences between postoperative anastomotic strictures in the 25 mm (14%) and the 28 mm groups (14%) (p = 0.863). Within patients with postoperative anastomotic strictures, a median number of 2 dilatations were observed in each group (p = 0.573) without differences in the time to first diagnosis (p = 0.412). Conclusion There were no differences in anastomotic insufficiency and postoperative anastomotic stricture rates between the 25 mm and the 28 mm circular stapled esophagogastric anastomosis after Ivor Lewis esophagectomy. Both the 25 mm and 28 mm stapler can be safely used to create a circular stapled esophagogastric anastomosis to restore continuity after esophagectomy.

Endoscopic filling with polyglycolic acid sheets and fibrin glue of persistent fistula after esophagectomy

Background Treatment of anastomotic leakage in reconstruction after esophagectomy remains challenging. This report presents a new endoscopic filling method for persistent fistula after failure of conservative treatment of leakage caused by anastomotic insufficiency. Methods 10 of 14 patients, in whom post-esophagectomy leakage had failed to resolve after 2 weeks of conservative treatment, underwent endoscopic filling with polyglycolic acid (PGA) sheet and fibrin glue into the anastomotic leakage site, using a delivery tube and endoscopic catheter, respectively. Results Each patient underwent jejunostomy, to secure nutrition. The leakage was resolved in all 10 patients. The mean number of PGA – fibrin glue procedures was 1.7. The mean period from the first application to the resumption of oral intake was 31.6 days, from the final application it was 14.7 days. Conclusions The reported filling method offers a new endoscopic approach for persistent fistula after esophagectomy when conservative treatment of leakage has failed.

A szájüreg baktériumflórájának összefüggése az anastomosiselégtelenség következményeivel nyelőcső- és cardiatumoros betegeknél

Introduction: In the course of anastomotic insufficiency following resection of esophageal cancers the bacterial compound of the esophageal substance has a remarkable, presumable role in the outcome of complications. Aim: The purpose of this study is to compare the consequences of the anastomotic leak with the bacterial flora of patients’ oral cavity. Method: In this prospective study a total of 131 patients were investigated directly before the surgical intervention taking a bacterial sample. Bacterial flora of patients’ oral cavity was analysed; and the correlation between the consequences of the anastomotic leak and the content of the bacterial flora was examined. Results: Pathogenic bacteria in the oral microflora in 50 cases (38.2%) was found. Statistically significant, moderate correlation was found between the severity of the complication and the incidence of pathogenic bacteria (rs = 0.553; p≤0.05). Conclusions: Pathogenic agent in the microbial flora might induce higher risk and more severe outcome in case of anastomotic leakage and it might be evaluated as a determinative factor. Consideration of the bacterial flora of the oral cavity requires more attention in the preoperative preparation than before and it demands the change of the current practice. Orv. Hetil., 2017, 158(1), 25–30.