Value of the multi-slice spiral CT angiography, CT colonography and image fusion technology in preoperative evaluation of laparoscopic right colon cancer

Abstract

Objective To observe the distribution and variation of right colonic vessels, and investigate the clinical value of computed tomography angiography (CTA), computed tomography colonography (CTC) and image fusion technology in preoperative evaluation of laparoscopic right colonic cancer (RCC). Methods The retrospective and descriptive study was conducted. The clinicopathological data of 38 patients who underwent laparoscopic extended radical resection of RCC + D3 lymphadenectomy in the Affiliated Wuxi Second People′s Hospital of Nanjing Medical University between January 2015 and July 2017 were collected. Patients received preoperative plain and enhanced scans of abdominal and pelvic CT. The original images were reconstructed and fused by CTA and CTC, and then coming out with three-dimensional images of blood vessels and gut. Observation indicators: (1) branches of superior mesenteric artery (SMA); (2) positional relationship between SMA and superior mesenteric vein (SMV); (3) composition of gastrocolic venous trunk. Results Scan images of 38 patients had fused with scan images of vessels and primary tumors and reached the diagnostic standard, with a good imaging performance. Distribution of blood vessels of virtual reality (VR) images and were compared with that of naked blood vessels under intraoperative laparoscopy, showing a coincidence rate of 100.0%(38/38). (1) Branches of SMA: results of CTA and intraoperative anatomy showed that the occurrence rate of the right colonic artery, middle colonic artery and ileocolic artery were respectively 94.7%(36/38), 92.1%(35/38) and 100.0%(38/38). A right colonic artery was found in 28 patients. Ten patients had structure variation of right colonic artery, including 3 with 2 right colonic arteries and 2 without right colonic artery. The right colonic artery and middle colonic artery merged into the same trunk and then flowed into SMA were detected in 2 patients; the right colonic artery and ileocolic artery merged into the same trunk and then flowed into SMA were detected in 3 patients. (2) Positional relationship between SMA and SMV: results of CTA and intraoperative anatomy showed that the occurrence rate of both SMA and SMV was 100.0%(38/38). The SMA in 20 patients was located in the ventral side of SMV; SMA in 18 patients was located in the dorsal side of SMV. (3) Composition of gastrocolic venous trunk: results of CTA and intraoperative anatomy showed that 29 of 38 patients had gastrocolic venous trunks, which belonged to four sources, including right colonic vein, middle colonic vein, right gastric epiploic vein and anterior superior pancreaticoduodenal vein. Among 29 patients, 18 had 2- or 3-branch type of gastrocolic trunk that consisted of the right gastric epiploic vein, middle colonic vein and right colonic vein; 3 had 2-branch type of gastric pancreatic trunk that consisted of the right gastric epiploic vein and anterior superior pancreaticoduodenal vein; 8 had 3- or 4-branch type of stomach-pancreas-colon trunk that consisted of right gastric epiploic vein, anterior superior pancreaticoduodenal vein, right colonic vein and middle colonic vein. Conclusion CTA, CTC and image fusion technology can intuitively show the anatomy and variation of right colonic vessels, with a high clinical value. Key words: Colonic neoplasms; Preoperative evaluation; Vascular reconstruction; Computed tomography angiography; Computed tomography colonography; Extend right hemicolectomy; Laparoscopy