Anatomy Of The Inferior Mesenteric Artery And Its Application In Laparoscopic Radical Operation Of Rectal Cancer

Purpose In laparoscopic radical operation of rectal cancer,according to the tie of the inferior mesenteric artery(IMA),it is divided into the high tie(HT)of the IMA at its origin and the low tie(LT)of the IMA below the branch into the left colic artery(LCA)with preservation of the LCA.Both HT and LT are well-known strategies in rectal surgery.The pros and cons of the two methods have been discussed ever since.In laparoscopic radical resection of rectal cancer,IMA root lymph node dissection is necessary,which plays a very important role in the prognosis of patients.The aim of this study was to compare the mean peak flow velocity(Vm)of the marginal arch after clamping the inferior mesenteric artery at a high level and clamping the inferior mesenteric artery at a low level,and to study the vascular anatomy of the IMA and its positional relationship with the inferior mesenteric vein(IMV)to safely and effectively dissect the lymph nodes around the IMA root while preserving the LCA in a laparoscopic procedure for rectal cancer.Methods A non-randomized prospective study was conducted in 53 patients who underwent laparoscopic radical resection of rectal cancer.IMA,LCA,sigmoid artery(SA)and superior rectum artery(SRA)were exposed.Ultrasound was used to measure the Vm of the marginal arch before clamping the IMA,high clamping the IMA and low clamping the IMA.The relationship among the IMA,LCA,SA and SRA was evaluated,and the length from the IMA to the LCA or common trunk of LCA and SA was measured.The relationship between the IMV and the LCA was also evaluated.Results All 53 patients underwent LCA-preserving laparoscopic radical resection of rectal cancer.The Vm of the marginal arch in before clamping the IMA,high clamping the IMA,low clamping the IMA was 9.83±4.42cm/s,7.95±3.28cm/s,13.69±4.64cm/s,respectively.There were significant differences in Vm among the three groups.The Vm of high clamping IMA is lower than before clamping the IMA(p=0.021).The Vm of low clamping IMA is significantly higher than the high clamping IMA and the before clamping the IMA(p <0.01).Three patterns of the bifurcation of the IMA were identified in this study.In type ?,LCA arose independently from IMA(49.1%,n=26);in type ?,LCA and SA branched from a common trunk of the IMA(26.4%,n=14);and in type ?,LCA,SA,and SRA branched at the same location(24.5%,n=13).The length from the IMA to the LCA for all cases were 37.3±6.0mm.The length from the IMA to the LCA in types ?,?,and ? was 37.5±5.6,38.2±8.4,and 36.1±3.2mm,respectively.There was no significant difference between the three types.LCA was located under the IMV in 18 cases and above the IMV in 35 cases.Conclusion This study shows that during laparoscopic radical rectal cancer surgery,the Vm of the marginal arch after low clamping of IMA is higher.This suggests that after LT,the anastomosis may get better blood perfusion.The vascular anatomy of IMA and IMV is essential for laparoscopic radical rectal cancer resection with LCA preservation.Identifying the different branches of the IMA and its positional relationship with the IMV are necessary to clean up the lymph nodes and dissect the blood vessels.LT combined with IMA root lymph node dissection is completely acceptable.