A Study of Variations in Sacral Hiatus and Its Clinical Significance

The variations of sacral hiatus in dry bone are important as it determines access of sacral hiatus for caudal epidural anesthesia and analgesia. So the present study was conducted on 44 adult dry sacra in department of Anatomy, All India Institute of Medical Sciences,Bhubaneshwar,Odisha,India with the aim to find out the anatomical variations of sacral hiatus(SH) including shape, length, anteroposterior (A-P) diameter at apex and transverse width at base , distance from apex of sacral hiatus to foramina of S2 vertebra and the equilateral triangle formed between the apex of sacral hiatus and the two superolateral sacral crest. Most commonly found shape of sacral hiatus in this study was inverted U/V shape. The most common composition of sacrum in our study was 5 segments in 34 (77.27%) followed by 6 segments having sacralisation in 7(15.91%) and coccyx ankylosis in 3(6.82%). The sacral index in males was 92.42±8.20 and in females 118.81±3.77, which was statistically significant (p<0.0001).Most common position of apex and base of sacral hiatus was at the level of 4and 5 sacral vertebra respectively. The mean length, width and AP diameter at the apex of sacral hiatus were20.42±8.75, 12.31±2.87 and4.89±1.25mmrespectively.It can be concluded that anatomical variations in sacral hiatus are cause of caudal epidural anesthesia failure and procedure related complications. Understanding these variations may improve success of caudal epidural anesthesia and decrease incidence of complications. So this study will be useful to increase success rate of epidural anesthesia.