Anatomy of sacral hiatus and its importance of caudal epidural block

Caudal epidural block is used for anaesthetic solution into sacral canal via sacral hiatus. Today, caudal anaesthesia is prefered a wider used for prevention of chronic low back pain backache pain, control of intraoperative analgesia such as genitourinary surgical approach and labor pain cases in sacral epidural space approach for the implementation of analgesia. The aim of this study using anatomical structure and differences of the sacral hiatus using the sacral bone guide point to failure criteria for reviewing the caudal epidural anesthesia, and to improve the criteria for success in practice. In this study, detailed morphometric measurements on 87 specimens of sacra, Ege University Faculty of Medicine, Department of Anatomy of Osteology archive was made using digital calipers in 0.01sensitivity. The shapes of the aperture of the sacral hiatus were the inverted U shape often 33.33%, 19.45% often inverted V was detected% 19.45 often irregularly shaped. In addition, 6.9% of cases often sacral hiatus dumbbell shape, while 6.9% 3.45% often lack sacral hiatus and bifida shape were found. The level of the apex sacral hiatus S3 in 10.34%, 70.11% in S4 and 11.49% in S5 were observed. The sacral hiatus was no detected in 6.9% of cases. In this study, base of the sacral hiatus was found as S4 in 2.3% and 82.76% frequency in S5. The level of maximum curvature of sacrum was S3 in 62.07% and S4 in 28.78%. An average length of the sacral hiatus as 28.7 ± 7.1 mm, the average distance of the intercornual distance as 13.48 ± 2.69 mm, the average of the apex sacral hiatus and S2 vertebra hole as 34.68 ± 7.09 mm was measured. The angle measurements were calculated using Image J program. Samples and measured values were compatible with previous studies. Sacralisation often was observed as bilateral in 19.35 %, partial unilateral right edge in 6.45%, partial double-sided in 16.13% was found. Lumbarization was seen as 12.9%. Findings of spina bifida level were found 16.13% often in L5 - S1 segment. Bilateral measurements were determined no statistically significant difference (p> 0.05). The important anatomic landmarks of the caudal epidural anesthesia were sacral cornua, superolateral sacral crests, apex of the sacral hiatus, base of the sacral hiatus, the top portion of the median sacral crest, anteroposterior distance of the of the sacral canal, intercornual distance, distance of apex sacral hiatus to S2 vertebra hole. This guide can be done by considering the points and secure a successful venture. Keywords: morphometry; sacrum; sacral hiatus; caudal epidural block