The Role Of 3D Reconstruction Of Inferior Mesenteric Artery Using Multi-slice Spiral Computed Tomography Angiography In Radical Resection Of Rectal Cancer

Objective In this study,image data of the patients’ preoperative multi-slice spiral CT angiography(3D MSCTA)were collected to determine the branch patterns of the inferior mesenteric artery(IMA).With the data compared with those in the operation videos to verify the branch pattern,the data sorted out and a new IMA classification proposed,the goal was to achieve of well comprehending the role of 3D MSCTA in detecting IMA classification preoperatively,as well as its significance in radical resection of rectal cancer.Methods A retrospective analysis was done based on the clinical data of inpatients with rectal cancer or distal sigmoid colon cancer between November 2019 and November 2020 in the Hepatobiliary and Pancreatic Laparoscopic Surgery Department of Affiliated Zhongshan Hospital of Dalian University.The IMA classification criteria in this article are as follow.Type A: each and every sigmoid artery(SA)is derived from superior rectal artery(SRA),left colic artery(LCA)and SA can be plural;Type Bx:certain SA(s)originates from the last LCA,and left colic artery(LCA)and SA can be plural(x is the number of SA(s)from the last LCA,with a minimum of 1);Type Cx:LCA,SA and SRA issue from the same point of IMA,and LCA and SA can be plural(x is the number of SA(s)from the last LCA,with a minimum of 0);Type D: no LCA at all.According to the IMA classification criteria in this article,IMA classification and recording were performed by interpreting 3D MSCTA images,and the interpreted IMA branch patterns were verified by reviewing the surgical videos.Finally,the accuracy of3 D MSCTA’s interpretation of IMA branch patterns is calculated.Results 1.Subjects: A total of 41 patients met the inclusion criteria of this study,including 26 males(63.4%)and 15 females(36.6%).The age range is 34 to 75 years old,and the median is 62 years old.There are 31 patients with rectal cancer,and 13 patients with distal sigmoid colon cancer.The number of IMA in all 41 cases is one,whose origin was all abdominal aorta.2.IMA branch patterns: according to preoperative 3D MSCTA interpretation,16 cases(39.0%)of type A,19 cases of type Bx(all type B1,46.3%),6 cases of type Cx(all type C0,14.6%)),Type D is not seen.The preoperative3 D MSCTA interpretation was compared with the IMA branch patterns seen during the operation.One patient had a Riolan arch variation between the superior mesenteric artery(SMA)and the LCA;one patient was found to have two LCAs during the operation,yet the preoperative 3D MSCTA image had shown only one.3.Accuracy of3 D MSCTA: According to the collated data results,out of all the preoperative interpretation of 41 patients’ branch patterns,40 cases are completely consistent with the results of intraoperative verification.One patient had only one LCA in the 3D MSCTA before the operation;however,two were found during the operation.In this study,the accuracy of 3D MSCTA for IMA classification was 97.6%(40/41).Intraoperative and postoperative conditions: 41 patients successfully underwent laparoscopic radical resection of rectal cancer(Dixon’s style),and no conversion to laparotomy occurred.No patient received blood transfusion,and the patient’s maximum bleeding volume was about 400 ml.Postoperatively,it was confirmed by symptoms and CT results of plain abdominal scan that there was no anastomotic leakage and no deaths occurred.Other complications that occurred include: 3 cases of incision infection and 2 cases of lung infection.The average hospital stay was 13 days,the shortest hospital stay was 11 days,and the longest hospital stay was 25 days.Conclusion Although 3D MSCTA is not 100% accurate in predicting the IMA classification and related variations of patients with rectal cancer preoperatively,it still has a high reference value,together with an important role in radical resection of rectal cancer.The IMA classification proposed in this article has a certain degree of scientificity and wide coverage,and has good practicability.It can provide a certain reference for the game between high ligation and low ligation of radical rectal cancer.The IMA classification proposed in this article exhibits a certain degree of scientificity and wide coverage,and is of good practicability.It can provide a certain reference for the game between high ligation and low ligation in radical rectal cancer.