Morphometric Study of Sacral Hiatus with Significance in Interventional Clinical Procedure

Introduction: The sacral hiatus is an important portal for interventional clinical procedure. Identification of sacral hiatus is usually easy but sometime it becomes difficult particularly in obese person. Aim of present study was to identify additional anatomical landmarks to increase the success rate of trans-sacral hiatal procedure. Methodology: The morphometric study was conducted on 31undamaged adult sacra. The measurements were done with the help of Vernier caliper and goniometer. Results : The posterior superior iliac spines impose upon upper part of lateral sacral crest (superolateral crest). The distance between two superolateral crests was considered as the base and distance from two superolateral crests to apex of sacral hiatus as two sides of the triangle. The base, right side and left side of the triangle were 65.81 mm ± 4.00mm, 66.74 mm ± 6.18 mm and 66.84mm ± 6.07m respectively. The mean depth (AP diameter) of sacral canal at the apex of sacral hiatus was 4.17 mm ± 1.18 mm. An additional important landmark, the mean distance from the level of sacral cornua to the level of S2 foramina was 59.23mm ± 4.77mm. Conclusion: The triangle formed by the two superolateral crests and apex of the sacral hiatus was an equilateral triangle in most of the sacra and this is very important parameter in localization of sacral apex in transacral hiatal procedures. The AP diameter of sacral canal at the apex was adequate for passage of needle and endoscope in most of the specimens.