The Clinical Anatomic Study Of The Lower Segmental Artery

Objective: To explore the method of reducing arterial bleeding in the lower lumbar lateral surgical approach.Methods: We dissected 21 adult corpses under a microscope, to observe the route of the lower lumber arteries, from their origin to the processus transversus----the routes, branches, exterior diameter of these arteries and their relationship with the intervertebral foramen and prezone of processus transversus.Results: The Lower lumbar segmental artery originates from the posterior of the abdominal aorta and goers laterally along the vertebrae. The lower lumbar segmental artery travels in the supersulcus of the concavity lateral to the vertebrae, which is in the deep surface between the greater psoas muscle and the sympathetic trunk. Under the vein is the artery. Besides, under the Lower lumbar segmental artery , some branches of the sympathetic trunk pass side by side with the segmental arteries and veins, whose right side also stretches towards the back of inferior vena cava. 1-3 nourishing arteries project from the vertebrae. Backwards to the foramen intervertebrale , they generate grosser anterior branches of the processus transversus, which then permeate into the greater psoas muscle; still at the back, they generate spinal branches, traveling inwardly to the foramen intervertebrale and nerve root; they also generate dorsal branches while passing the transverse process outwardly towards the back of the lumbar vertebra.Different lumbar arteries appear in different rates here. The appearance rates of L3A and L4A remain constant while that of L5A is quite variable. The main trunks and branches of L3A and L4A are distributed at the rate of 71.43% in the of the lateral border of the pedicle of vertebral arch of L3A and 62.07% in the 1/3 of intervertebral foramen of L4/5A. In the prezone of processus transversus, the anterior branches of L3A and L4A originate mostly from the inner side of point upper 1/3, then slants outward down to the outer side of middle point 1/3 at the rate of 66.67% or from the upper1/3 point down to the lower 1/3 point at the rate of 63.64% .Conclusion: The Lower lumbar segmental arteries runs a relatively constant on the side of in the lower lumbar lateral vertebral body, intervertebral foramen area and prezone of processus transversus. the lower lumbar segmental arteries can be processed on the side of in the lower lumbar lateral vertebral body easily.The starting point of the lower lumbar segmental arteries and their branches are measured. We can identify them more clearly.1. Lower lumbar segmental arteries appear at a high rate here, especially for segment 3 lumbar arteries(92.86%)and segment 4 lumbar arteries (83.33%).2. Lower lumbar segmental arteries usually go along fixed lines, especially when they are lateral to the centrum, where they mainly travel in superfissure. Therefore, if lumbar segmental arteries are injured during the operation, we may dissect the greater psoas muscle and unfold lumbar segmental arteries, upon which haemostasis and hypodesis could be applied.3. A good measurement of the initial point of the Lower lumbar segmental arteries and their branches could help us identify lumbar segmental arteries and take suitable measures.4. Outside the intervertebral foramen, segmental 3 lumbar arteries are mainly distributed laterally along the pedicle of vertebral arch(71.43%), while segmental 4 lumbar arteries are mainly distributed at 1/3 intervertebral foramen of L4/5 (62.07%); In the transverse process prezone, the transverse process anterior ramus of segmental 3 lumbar arteries always start from the upper point 1/3 inside the intervertebral foramen and travel outwardly down to the middle point 1/3 outside the intervertebral foramen(60%), while the transverse process anterior ramus of segmental 4 lumbar arteries always travel from the upper point 1/3 down to the lower point 1/3 (58.33%).Special care should be paid here during operation. As it is close to nerve roots and major blood vessels, hemostasia would be difficult. It may work to alleviate the blooding in the place lateral to the centrum. Therefore, we should pay much attention to the arteries near the intervertebral foramen of lumbar segmental arteries and in the transverse process prezone, Which prove to be a good way to alleviate bleeding.5. Segmental 5 lumbar arteries have several origins, 42.31% from iliolumbar arteries, 34.62% from the lower branches of L4A and others from sacrococcygeal arteries. They pass along quite different ways from each other. When bleeding of undetermined origin happens here during an operation, segmental 5 lumbar arteries may be injured and we could take suitable treatment accordingly.A good treatment of the arteries near the lumbar vertebrae, intervertebral foramen and those in the prezone of processus transversus is an effective way to reduce bleeding in a certain operation...