Objective To observe the complication after embolizing the bilateral internal il iac arteries and the median sacral artery of dogs by different combinations and embolization levels with gelfoam particle, and to provide a reference for safety appl ication of gelfoam in cl inic. Methods Sixteen common grade adult healthy dogs (weighing 10-13 kg, 14 males and 2females) were randomly divided into 5 groups. Under the monitoring of digital subtraction angiography (DSA), the embolization was performed with gelfoam particle (diameter, 50-150 μm) in bilateral internal il iac arteries and the main branch of the median sacral artery (group A, n=3), in bilateral internal il iac arteries and the first branch of the median sacral artery (group B, n=3), in the main branch of bilateral internal il iac arteries (group C, n=3), in the unilateral internal il iac artery and the main branch of the median sacral artery (group D, n=4), and in the main branch of unilateral internal il iac artery (group E, n=3). Under the DSA, the anatomic relationships of the abdominal aorta, bilateral external il iac arteries, bilateral internal il iac arteries, and median sacral artery were observed before embol ization. The survival dogs were observed and the specimens of bladder, rectum, sciatic nerve, and gluteal muscles were harvested for the general and histological observations at 3 days after embolization. Results In dogs, there was no common il iac artery; bilateral external il iac arteries originated from the abdominal aorta and the starting of the median sacral artery had variation. Seven dogs (3 in group A, 3 in group C, and 1 in group D) died within 2 days after embolization, and the others survived to the end of the experiment. In the dead dogs of groups A, C, and D, the darkening and necrosis of the rectum were observed; the bladder presented lamellar obfuscation and focal hemorrhage and edema; and the median urinary volume in bladder was 270.6 mL. In survival dogs, no obvious change was observed in the rectum; the bladder only manifested l ight edema; and the median urinary volume in bladder was 137.0, 220.5, and 28.0 mL, respectively in groups B, D, and E.The rectum and bladder of dead dogs in groups A, C, and D manifested the disrupted cells, generous inflammatory cells infiltration, and desquamation of epithel ial cells; the rectum and bladder of survival dogs in groups B, D, and E manifested l ight inflammatory cells infiltration and edema; the embol ized artery mainly focused on the arterioles whose diameter was 100-200 μm. The sciatic nerve and gluteal muscles of each group had no obvious change except for l ight edema. Conclusion When the internal il iac artery and median sacral artery are embol ized with gelfoam particle with a diameter of 50-150 μm, to ensure the safeness of pelvic organs, the embol ized artery can not exceed the first branch when the 3 arteries are embol ized at the same time, or reserve at least unilateral internal il iac artery when embol ized to the trunk , or it will result in pelvic organ necrosis and perforation.
【摘要】 目的 对骶正中动静脉的位置分布及变异进行解剖观察及实际测量其与周围重要结构的位置关系，为临床医师提高腰骶椎前路手术安全性提供必要的参考信息。 方法 收集2008年5月-2011年1月期间因疾病及意外死亡者新鲜人体尸体标本30例，对其进行解剖学研究，观察并测量骶正中动、静脉的发出点与走行，骶正中动、静脉的数量与缺失情况，以及骶正中动、静脉间的相互走行关系。 结果 ①骶正中动脉在主动脉发出以及走行的位置相对固定，无明显多支与缺失情况；骶正中动脉均为腹主动脉根部背侧发出，未见发出点位于左右髂总动脉。发出后行于左侧髂总静脉后方，跨过腰5/骶1椎间盘下行。骶正中静脉与骶正中动脉伴行的情况占总数的60.0%；②骶正中静脉多支常见，没有发现有骶正中静脉的缺失。1支的占总标本数的66.7%，2支的占30.0%，3支的占3.3%。 结论 当选择分叉下入路，应该特别注意骶正中动静脉的解剖位置。动脉的变异相对较小，而静脉的变异程度非常大，发出点变异，多支的情况多见，这些原因都造成了静脉容易损伤的原因，在手术中应该特别注意。【Abstract】 Objective To investigate the clinical significance of anatomical features of middle sacral artery and vein for lumbar-sacral spinal surgery. Methods We carried out anatomical research on 30 cadavers caused by diseases or accidents collected between May 2008 and January 2011. We dissected the vascular system anterior to lumbar vertebrae to learn their characteristics. The initial point of middle sacral artery and confluent point of veins, and the numbers of, and the companion relationship between middle sacral arteries and veins were chosen as the indexes to be measured. Results The middle sacral arteries started from the aorta, and their locations were relatively fixed without absence or multi-branches. All the middle sacral arteries derived from the dorsal side of abdominal artery root, and were not started from the common iliac artery. Then, the sacral arteries went at the back of left common iliac vein, and went down after traversing the inter-vertebral disk between the fifth lumbar and first sacral vertebra. About 60% of the middle sacral veins were accompanied with the arteries. Multi-branches of the middle sacral veins were frequently seen, and no absence was observed. One-branch, two-branch and three-branch middle sacral veins occupied 66.7%, 30.0% and 3.3% respectively out of the total. Conclusions When choosing downward branch approach during the operation, we should pay special attention to the anatomical locations of the middle sacral arteries and veins. Compared with the arteries, there are greater variations of the veins including variations of the confluent point and branches which can cause the veins to be quite vulnerable.
ObjectiveTo investigate the distance between the screw-out point and the middle sacral artery, and evaluate the safety when the S1 pedicle screw placed by the three cortical fixation techniques.MethodsFrom March to June 2018, randomized CT scan data of 98 adult pelvic angiography were selected to measure the distance from the middle sacral artery to the anterior edge of the vertebral body (a) and the distance from the middle sacral artery to the midline of the vertebral body (b). S1 screw entry point was set as the intersection of lines where extension of S1 facet joint inferior margin and lateral margin cross over. Introversion angles of 10, 15, 20, and 25° were used; the distance between the screw insertion point and the middle sacral artery (d) was measured.ResultsThe middle sacral artery was usually located on the left side of the upper endplate plane of S1. The distance a was (5.40±2.95) mm in 49 males and (4.43±2.32) mm in 49 females, and the difference between the males and females was not statistically significant (t=1.818, P=0.72). The distance b was (12.07±5.42) mm in 45 males and (14.12±4.88) mm in 48 females, and the difference between the males and females was not statistically significant (t=–1.914, P=0.59). The distance d was (12.67±6.00), (9.40±5.17), (7.50±3.76), and (8.10±3.64) mm when the nail was placed at a common internal inclination of 10, 15, 20, and 25°. The differences in the distance d at a common internal inclination of 10° vs. 15°, 10° vs. 20°, 10° vs. 25°, and 15° vs. 20° were all statistically significant (t=16.828, 11.609, 6.073, 6.254; P<0.008 3); there was no statistically significant difference in that at 15°vs. 25°, or 20° vs. 25° (t=2.034, –1.723; P>0.05).ConclusionBy analyzing the relationship between the middle sacral artery and the upper endplate plane of the S1 vertebra, the risk of middle artery injury is small while the biomechanical stability of the screw is increased when using the Lenham method.