An Anatomical Study Of The Origins Courses And Distributions Of The Dorsal Branches Of Lumbar Arteries

Background:Transforaminal lumbar interbody fusion(TLIF)was proposed in the 19th century.At present,it is widely used in a variety of lumbar fusion,such as degenerative disc disease,lumbar spondylolisthesis and recurrent disc herniation.However,the related literature reported that its complications were as high as 36%.It includes dural tear,infection,nerve injury,screw dislocation,retroperitoneal injury,lumbar artery injury,cauda equina syndrome and pseudoaneurysm.Pseudoaneurysm is an rare complication.Its symptoms are unknown and easy to ignore,which often leads to serious postoperative complications.It is reported that pseudoaneurysms often occur near the transverse process and facet joints after TLIF.Some scholars divide the lumbar artery into lateral branch,dorsal branch,plexus branch and intervertebral disc branch.The dorsal branch of lumbar artery is divided into transverse branch,ascending branch,descending branch and nerve root branch.Then,the anatomy of the dorsal branch of the anterior related artery is still not detailed,but the classification is simply found in the outer area of the intervertebral foramen.There is a lack of specific shape and distribution range of its branches.The shape,distribution and diameter of its branches in the transverse process,facet process and other parts still need to be further explored.Objective:The purpose of this study is to explore the origins and distributions of lumbar artery and its branches at L1-L4 level,especially the dorsal branch,in order to provide detailed anatomical information for reducing related complications with TLIF.Methods:Ten embalmed cadavers were studied after their arterial systems were injected with red latex.The quantity,origin,pathway,distribution range and diameter of the branches were were recorded and photographed.The relationship between the dorsal branch of lumbar artery and peripheral bone structure and nerve was observed and recorded.Results:The lumbar artery was divided into lateral branch,dorsal branch,intervertebral disc branch and spinal branch.The plexus branches of lumbar artery were found in 52 intervertebral foramen,most commonly in L2 segment.Transverse branch,ascending branch and descending branch of the dorsal branch were found in all 80 intervertebral foramen.68 intervertebral foramen showed that the ganglionic branches were sent out from the dorsal branch,which were most common in L3 segment.The transverse branch was divided into 2 types:in type 1,the arteries divided into superior branches and inferior branches;the arteries in type 2 divided into 3 branches(superior,intermedius and inferior branches).In 24(30%)intervertebral foramen,transverse branches were found near the transverse process,which was the most common in L2 segment.Conclusion:The dorsal branch divided into transverse branch,ascending branch,descending branch and ganglionic branch.However,only transverse branches were found in the blood vessels around the transverse process and facet joints.A thorough understanding of the course of the dorsal branch and its branches may be very important to reduce intraoperative bleeding and the occurrence of postoperative pseudoaneurysms.