Artificial intelligence based real-time microcirculation analysis system for laparoscopic colorectal surgery

BACKGROUND Colonic perfusion status can be assessed easily by indocyanine green(ICG)angiography to predict ischemia related anastomotic complications during laparoscopic colorectal surgery.Recently,various parameter-based perfusion analysis have been studied for quantitative evaluation,but the analysis results differ depending on the use of quantitative parameters due to differences in vascular anatomical structure.Therefore,it can help improve the accuracy and consistency by artificial intelligence(AI)based real-time analysis microperfusion(AIRAM).AIM To evaluate the feasibility of AIRAM to predict the risk of anastomotic complication in the patient with laparoscopic colorectal cancer surgery.METHODS The ICG curve was extracted from the region of interest(ROI)set in the ICG fluorescence video of the laparoscopic colorectal surgery.Pre-processing was performed to reduce AI performance degradation caused by external environment such as background,light source reflection,and camera shaking using MATLAB 2019 on an I7-8700k Intel central processing unit(CPU)PC.AI learning and evaluation were performed by dividing into a training patient group(n=50)and a test patient group(n=15).Training ICG curve data sets were classified and machine learned into 25 ICG curve patterns using a self-organizing map(SOM)network.The predictive reliability of anastomotic complications in a trained SOM network is verified using test set.RESULTS AI-based risk and the conventional quantitative parameters including T1/2max,time ratio(TR),and rising slope(RS)were consistent when colonic perfusion was favorable as steep increasing ICG curve pattern.When the ICG graph pattern showed stepped rise,the accuracy of conventional quantitative parameters decreased,but the AI-based classification maintained accuracy consistently.The receiver operating characteristic curves for conventional parameters and AI-based classification were comparable for predicting the anastomotic complication risks.Statistical performance verifications were improved in the AI-based analysis.AI analysis was evaluated as the most accurate parameter to predict the risk of anastomotic complications.The F1 score of the AI-based method increased by 31% for T1/2max,8% for TR,and 8% for RS.The processing time of AIRAM was measured as 48.03 s,which was suitable for real-time processing.CONCLUSION In conclusion,AI-based real-time microcirculation analysis had more accurate and consistent performance than the conventional parameter-based method.

Risk factors for nonclosure of defunctioning stoma and stoma-related complications among low rectal cancer patients after sphincter-preserving surgery

Background::Defunctioning stoma is widely used to reduce anastomotic complications in rectal cancer surgery.However,the complications of stoma and stoma reversal surgery should not be underestimated.Furthermore,in some patients,stoma reversal failed.Here,we investigated the complications of defunctioning stoma surgery and subsequent reversal surgery and identify risk factors associated with the failure of getting stoma reversed.Methods::In total,154 patients who simultaneously underwent low anterior resection and defunctioning stoma were reviewed.Patients were divided into two groups according to whether their stoma got reversed or not.The reasons that patients received defunctioning stoma and experienced stoma-related complications and the risk factors for failing to get stoma reversed were analysed.Results::The mean follow-up time was 47.54(range 4.0-164.0)months.During follow-up,19.5%of the patients suffered stoma-related long-term complications.Only 79(51.3%)patients had their stomas reversed.The morbidity of complications after reversal surgery was 45.6%,and these mainly consisted of incision-related complications.Multivariate analyses showed that pre-treatment comorbidity(HR=3.17,95%CI 1.27-7.96,P=0.014),postoperative TNM stage(HR=2.55,95%CI 1.05-6.18,P=0.038),neoadjuvant therapy(HR=2.75,95%CI 1.07-7.05,P=0.036),anastomosis-related complications(HR=4.52,95%CI 1.81-11.29,P=0.001),and disease recurrence(HR=24.83,95%CI 2.90-213.06,P=0.003)were significant independent risk factors for a defunctioning stoma to be permanent.Conclusions::Defunctioning stoma is an effective method to reduce symptomatic anastomotic leakage,but the stoma itself and its reversal procedure are associated with high morbidity of complications,and many defunctioning stomas eventually become permanent.Therefore,surgeons should carefully assess preoperatively and perform defunctioning stomas in very high risk patients.In addition,doctors should perform stoma reversal surgery more actively to prevent temporary stomas from becoming permanent.