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Anatomy of the sacral hiatus and its clinical relevance in caudal epidural block

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Abstract

Purpose

Caudal epidural anesthesia (CEB) is widely used for the prevention of chronic lower back pain, the control of intraoperative analgesia such as genitourinary surgery and labor pain cases in sacral epidural space approach for the implementation of analgesia. CEB is an anesthetic solution used into the sacral canal via sacral hiatus (SH). For optimal access into the sacral epidural space, detailed anatomical landmarks of SH are required. This study aims at exploring the anatomical structures and differences of the SH by using the sacral bone as a guide point to failure criteria for reviewing the caudal epidural anesthesia and improving the criteria for success in practice.

Materials and methods

Detailed morphometric measurements of orientation points of the SH were taken in 87 sacral bones. The measurements were taken using digital calipers and calculated with photogrammetric methods using Image J program.

Results

Most commonly encountered shape of the SH was inverted U (33.33%), while 6.9% 3.45% often lack SH and bifida shape were found. The average length of the SH was 28.7 ± 7.1 mm, the average distance of the intercornual distance was 13.48 ± 2.69 mm, the average of the apex of SH and S2 sacral foramen was 34.68 ± 7.09 mm. There was no statistically significant difference determined in bilateral measurements (p > 0.05). Apex and base of SH were most commonly observed against S4 and S5 vertebrae, respectively. The level of maximum curvature of sacrum was S3 in 62.07% and S4 in 28.78%. Findings of spina bifida level were found 16.13% often in L5–S1 segment. Sacral cornua were marked by their bilateral presence in 55.26% and impalpable in 21.05% cases. Minimum distance between the S2 and the apex of the SH was 7.25 mm which suggested that it would not be safe to push the needle beyond 7 mm into the sacral canal so as to avoid dural puncture. In 8.77% cases, the depth of hiatus was less than 3 mm.

Conclusions

Single bony landmark may not help in locating the SH because of the anatomical variations. Important anatomical landmarks of the CEB are the sacral cornu, lateral sacral crests, the apex of the SH, the base of the SH, the top portion of the median sacral crest, anteroposterior distance of the sacral canal, intercornual distance, distance of the apex of the SH to the S2 foramina. Depth of hiatus less than 3 mm may be one of the causes for the failure of needle insertion. Surrounding bony irregularities, different shapes of hiatus and defects in dorsal wall of sacral canal should be taken into consideration before undertaking CEB so as to avoid its failure. This guide can be done by considering the points and securing a successful venture.

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References

  1. Abukawa Y, Hiroki K, Morioka N, Iwakiri H, Fukada T, Higuchi H, Ozaki M (2015) Ultrasound versus anatomical landmarks for caudal epidural anesthesia in pediatric patients. BMC Anesthesiol 14(15):102. doi:10.1186/s12871-015-0082-0.PMID:26169595

    Article  Google Scholar 

  2. Aggarwal A, Aggarwal A, Harjeet, Sahni D (2009) Morphometry of sacral hiatus and its clinical relevance in caudal epidural block. Surg Radiol Anat 31(10):793–800. doi:10.1007/s00276-009-0529-4 (PMID:19578805)

    Article  PubMed  Google Scholar 

  3. Aggarwal A, Kaur H, Batra YK, Aggarwal AK, Rajeev S, Sahni D (2009) Anatomic consideration of caudal epidural space: a cadaver study. Clin Anat 22(6):730–737. doi:10.1002/ca.20832.PMID:19637298

    Article  PubMed  Google Scholar 

  4. Black MG (1949) Anatomic reasons for caudal anesthesia failure. Anesth Analg 28:33–39

    Article  CAS  Google Scholar 

  5. Bush K, Hillier S (1991) A controlled study of caudal epidural injections of triamcinolone plus procaine for the management of intractable sciatica. Spine 16:572–575

    Article  CAS  PubMed  Google Scholar 

  6. Busoni P, Sarti A (1987) Sacral intervertebral epidural block. Anesthesiology 67(6):993–5 (PMID: 3688545)

    Article  CAS  PubMed  Google Scholar 

  7. Chen CP, Tang SF, Hsu TC, Tsai WC, Liu HP, Chen MJ, Date E, Lew HL (2004) Ultrasound guidance in caudal epidural needle placement. Anesthesiology 101(1):181–4. (PMID:15220789)

    Article  PubMed  Google Scholar 

  8. Cicekcibasi AE, Borazan H, Arican S, Yılmaz MT, Sakarya ME (2014) Where is the apex of the sacral hiatus for caudal epidural block in the pediatric population? A radio-anatomic study. J Anesth 28(4):569–575. doi:10.1007/s00540-013-1758-6

    Article  PubMed  Google Scholar 

  9. Crighton IM, Barry BP, Hobbs GJ (1997) A study of the anatomy of the caudal space using magnetic resonance imaging. Br J Anaesth 78(4):391–5 (PMID:9135359)

    Article  CAS  PubMed  Google Scholar 

  10. Cuckler JM, Bernini PA, Wiesel SW (1985) The use of epidural steroids in the treatment of radicular pain. J Bone Joint Surg Am 67:63–66

    Article  CAS  PubMed  Google Scholar 

  11. Hollinshead WH (1982) Anatomy for Surgeons, Vol. 3: The Back and Limbs Third Edition ISBN-13: 978-0061412660$4 ISBN-10: 006141266X, Lippincolt Williams & Wilkins

  12. Kamal A, Ara S, Ashrafuzzaman M, Khatun K, Islam MS (2014) Morphometry of sacral hiatus and its clinical relevance in caudal epidural block. J Dhaka Med Coll 23(1):31–36

    Google Scholar 

  13. Kumar V, Nayak SR, Potu BK, Pulakunta T (2009) Sacral hiatus in relation to low back pain in south Indian population. Kumar Bratisl Lek Listy 110(7):436–441

    PubMed  Google Scholar 

  14. Lanier VS, McKnight HE, Trotter M (1944) Caudal analgesia: an experimental and anatomical study. Am J Obstet Gynaec 47(5):633–641

    Article  Google Scholar 

  15. Martin LVH (1994) Sacral epidural (caudal) block. In: Wildsmith JAW, Armitage EN (eds) Principles and practice of regional anaesthesia. Churchill Livingstone, Edinburgh, pp 127–134

    Google Scholar 

  16. Mourgela S, Anagnostopoulou S, Sakellaropoulos A, Koulousakis A, Warnke JP (2008) Sectioning of filum terminale externum using a rigid endoscope through the sacral hiatus. Cadaver study. J Neurosurg Sci 52(3):71–4 (PMID:18636050)

    CAS  PubMed  Google Scholar 

  17. Mustafa MS, Mahmoud OM, El Raouf HH, Atef HM (2012) Morphometric study of sacral hiatus in adult human Egyptian sacra: their significance in caudal epidural anesthesia. Saudi J Anaesth 6(4):350–7. doi:10.4103/1658-354X.105862.PMID:23493625

    Article  PubMed  PubMed Central  Google Scholar 

  18. Nadeem G (2014) Importance of knowing the level of sacral hiatus for caudal epidural anesthesia. J Morphol Sci 31(1):9–13. doi:10.4322/jms.ao053913

    Article  Google Scholar 

  19. Nagar SK (2004) A study of sacral hiatus in dry human sacra. J Anat Soc India 53(2):18–21

    Google Scholar 

  20. Najman IE, Frederico TN, Segurado AV, Kimachi PP (2011) Caudal epidural anesthesia: an anesthetic technique exclusive for pediatric use? Is it possible to use it in adults? What is the role of the ultrasound in this context? Rev Bras Anestesiol 61(1):95–109. doi:10.1016/S0034-7094(11)70011-3 (PMID:21334512)

    Article  PubMed  Google Scholar 

  21. Nikooseresht M, Hashemi M, Mohajerani SA, Shahandeh F, Agah M (2014) Ultrasound as a screening tool for performing caudal epidural injections. Iran J Radiol 11(2):e13262. doi:10.5812/iranjradiol.13262 (Epub 2014 May 15)

    Article  PubMed  PubMed Central  Google Scholar 

  22. Porzionato A, Macchi V, Parenti A, De Caro R (2011) Surgical anatomy of the sacral hiatus for caudal access to the spinal canal. Acta Neurochir Suppl 108:1–3. doi:10.1007/978-3-211-99370-5_1 (PMID:21107930)

    Article  PubMed  Google Scholar 

  23. Rickenbacher J, Landolt AM, Theiler K (2003) Lanz/Wachsmuth Praktische Anatomie. Rücken in Lehr- und Hilfsbuch der anatomischen Grundlagen ärztlichen Handelns, 2. Springer, ISBN 3540405666, 9783540405665$4

  24. Sekiguchi M, Yabuki S, Satoh K, Kikuchi S (2004) An anatomic study of the sacral hiatus: a basis for successful caudal epidural block. Clin J Pain 20:51–54

    Article  PubMed  Google Scholar 

  25. Senoglu N, Senoglu M, Oksuz H, Gumusalan Y, Yuksel KZ, Zencirci B, Ezberci M, Kizilkanat E (2005) Landmarks of the sacral hiatus for caudal epidural block: an anatomical study. Br J Anaes 95(5):692–695

    Article  CAS  Google Scholar 

  26. Senoglu N, Senoglu M, Ozkan F, Kesilmez C, Kızıldag B, Celik M (2013) The level of termination of the dural sac by MRI and its clinical relevance in caudal epidural block in adults. Surg Radiol Anat 35(7):579–584. doi:10.1007/s00276-013-1108-2 (PMID:23515954)

    Article  CAS  PubMed  Google Scholar 

  27. Shinohara H (1999) The size and position of the sacral hiatus in man. Okajimas Folia Anat Jpn 76(2–3):89–93 (PMID:10502960)

    Article  CAS  PubMed  Google Scholar 

  28. Trotter M (1947) Variations of sacral canal: their significance in the administration of caudal analgesia. Anesth Analg 26(5):192–202

    CAS  Google Scholar 

  29. Wang LZ, Hu XX, Zhang YF, Chang XY (2013) A randomized comparison of caudal block by sacral hiatus injection under ultrasound guidance with traditional sacral canal injection in children. Paediatr Anaesth 23(5):395–400. doi:10.1111/pan.12104 (PMID:23278906)

    Article  PubMed  Google Scholar 

  30. Williams A, Newell RLM, Collins P (2005) Back and macroscopic anatomy of spinal cord. In: Standring S (ed) Gray’s anatomy: the anatomical basis of clinical practice, 39th edn. Elsevier, Churchill Livingstone, Edinburgh, pp 725–773

    Google Scholar 

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Correspondence to Figen Govsa.

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Bagheri, H., Govsa, F. Anatomy of the sacral hiatus and its clinical relevance in caudal epidural block. Surg Radiol Anat 39, 943–951 (2017). https://doi.org/10.1007/s00276-017-1823-1

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