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Surgical Endoscopy

, Volume 21, Issue 12, pp 2207–2211 | Cite as

Anal canal anatomy showed by three-dimensional anorectal ultrasonography

  • F. Sergio P. Regadas
  • Sthela M. Murad-Regadas
  • Doryane M. R. Lima
  • Flavio R. Silva
  • Rosilma G. L. Barreto
  • Marcellus H. L. P. Souza
  • F. Sergio P. Regadas Filho
Article

Abstract

Background

Demonstrate precisely the anatomic configuration of the anal canal and the length and thickness of the anal sphincters using three-dimensional (3-D) anorectal ultra-sonography in both genders.

Methods

Twelve normal volunteer males and 14 females, with a mean age of 52.4 and 50.3 years, respectively, were prospectively enrolled in this study. All individuals from both groups were submitted to anorectal ultra-sonography. The anal canal was analyzed, measuring the length and thickness of the external anal sphincter (EAE), internal anal sphincter (IAS), puborectalis muscle (PR) and the gap (distance from the anterior EAS to the anorectal junction) in the midline longitudinal (ML) and transverse (MT) planes, and the results were compared between quadrants and genders.

Results

The distribution of sphincter muscles is asymmetric in both genders. The anterior upper anal canal is an extension of the rectal wall with all layers clearly identified. The anterior IAS is formed in the distal upper anal canal and is significantly shorter in female than in male in all quadrants. The anterior IAS length is shorter than the posterior and lateral in both genders. The anterior EAS length is significantly shorter (2.2 cm) and the gap is longer (1.2 cm) in female than in male (3.4 cm) (0.7 cm) (p < 0.05), respectively. The posterior and lateral EAS-PR is significant longer in males (3.6 cm) (3.9 cm) than in females (3.2 cm) (3.5 cm) (p < 0.05), respectively. The lateral EAS-PR is significant longer than the posterior part in both genders. The anterior IAS is significantly thicker in males (0.19 cm) than in females (0.12 cm) (p = 0.04).

Conclusion

3-D anal endosonography enabled measurement of the different anatomical structures of the anal canal and demonstrated its asymmetrical configuration. The shorter anterior EAS and IAS associated with a longer gap could justify the higher incidence of pelvic floor dysfunction in females, especially fecal incontinence and anorectocele with rectal intussusception.

Keywords

Anal canal Rectum Anatomy Ultrasound 

References

  1. 1.
    Deen Ki, Kumar D, Williams JG, Ollif J, Keighley MR (1993) The prevalence of anal sphincter defects in fecal incontinence: a prospective endosonic study. Gut 34:685–8CrossRefPubMedGoogle Scholar
  2. 2.
    Cheong DMO, Nogueras JJ, Wexner SD, Jagelman DG (1993) Anal endosonography for recurrent anal fistulas: image enhancement with hydrogen peroxide. Dis Colon Rectum 36: 1158–60CrossRefPubMedGoogle Scholar
  3. 3.
    Deen KI, Madoff RD, Belmonte C, Wong D (1995) Preoperative Staging of Rectal Neoplasms With Endorectal Ultrasonography. Semin Colon Rectal Surg 6(2): 78–85Google Scholar
  4. 4.
    Kim JC, Cho YK, Kim SY, Park SK, Lee MG (2002) Comparative study of three-dimensional and conventional endorectal ultrasonography used in rectal cancer staging. Surg Endosc 16(9): 1280–5CrossRefPubMedGoogle Scholar
  5. 5.
    Oberwalder M, Thaler K, Baig MK, Dinnewitzer A, Efron J, Weiss EG, Vernava AM, Nogueras JJ, Wexner SD (2004) Anal ultrasound and endosonographic measurement of perineal body thickness: a new evaluation for fecal incontinence in females. Surg Endosc 18(4): 650–4CrossRefPubMedGoogle Scholar
  6. 6.
    Gold DM, Bartram CI, Halligan S, Humphries KN, Kamm MA, Kmiot WA (1999) Three-dimensional endoanal sonography in assessing anal canal injury. Br J Surg 86: 365–70CrossRefPubMedGoogle Scholar
  7. 7.
    Williams AB, Bartram CI, Halligan S, Marshall MM, Nicholls RJ, Kmiot WA (2001) Multiplanar anal endosonography – normal anal canal anatomy. Colorectal Dis 3: 169–74CrossRefPubMedGoogle Scholar
  8. 8.
    Bollard RC, Gardiner A, Lindow S, Phillips K, Duthie GS (2002) Normal female anal sphincter: difficulties in interpretation explained. Dis Colon Rectum 45: 171–5CrossRefPubMedGoogle Scholar
  9. 9.
    West RL, Felt-Bersma JF, Hansen BE, Schouten R, Kuipers E (2005) Volume measurements of the anal sphincter complex in healthy controls and fecal-incontinent patients with a three-dimensional reconstruction of endoanal ultrasonography images. Dis Colon Rectum 48(3): 540–47CrossRefPubMedGoogle Scholar
  10. 10.
    Regadas SMM, Regadas FSP, Rodrigues LV, Silva FR, Lima DMR, Regadas-Filho FSP (2005) Importância do Ultra-som Tridimensional na Avaliação Anorretal. Arq Gastroenterol 42: 226–32CrossRefPubMedGoogle Scholar
  11. 11.
    Regadas FSP, Murad-Regadas SM, Wexner SD, Rodrigues LV, Souza MHLP, Silva FR, Lima DMR, Regadas Filho FSP (2006) Anorectal three-dimensional endosonography and anal manometry in assessing anterior rectocele in women: a new pathogenesis concept and the basic surgical principle. Colorectal Dis 9: 80–85CrossRefGoogle Scholar
  12. 12.
    Murad-Regadas SM, Regadas FSP, Rodrigues LV, et al. (2006) Ecodefecografia tridimensional. Nova técnica para avaliação da Evacuação Obstruída. Rev bras coloproct 26(2): 136–42Google Scholar
  13. 13.
    Murad-Regadas SM, Regadas FSP, Rodrigues LV, Silva FR, Soares FA, Escalante RD (2007) A novel 3D Dynamic Anorectal Ultrasonography Technique (Echodefecography) to Assess Obstructed Defecation Syndrome comparing with Defecography. Colorectal Dis (In press)Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • F. Sergio P. Regadas
    • 1
  • Sthela M. Murad-Regadas
    • 1
  • Doryane M. R. Lima
    • 1
  • Flavio R. Silva
    • 1
  • Rosilma G. L. Barreto
    • 1
  • Marcellus H. L. P. Souza
    • 1
  • F. Sergio P. Regadas Filho
    • 1
  1. 1.Department of SurgeryMedical School of the Federal University of Ceara and Hospital Sao CarlosFortalezaBrazil

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