Abstract
Purpose: This study was undertaken to investigate the effects of anal stretching on anal pressures and damage to the external anal sphincter. METHODS: This study was performed on 37 guinea pigs. Animals were divided into three groups: control group, quick stretching group, and continuous overstretching group. Anal stretching was conducted by an 8-F Foley® catheter balloon. RESULTS: It was found that if the muscle was stretched from 100 to 300 percent of its original length, anal resting pressure (ARP) kept relatively steady, but anal contracting pressure (ACP) gradually increased; from 300 to 370 percent, a sharp ARP increase was developed, but ACP gradually decreased to zero; beyond 370 percent, ARP remained unchanged (plateau phase). By histologic examination, it was revealed that when the muscle was stretched at the ARP plateau phase, an ischemic zone of necrosis and an edematous zone of necrosis could be clearly identified in the muscle. CONCLUSION: This study shows that length of the external anal sphincter definitively influences muscle strengths, and severe anal stretching will result in muscle damage. These results imply that the sphincteric muscle complex in high or intermediate anorectal anomalies may be injured during present conventional surgical approaches.
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References
Stephens FD. Imperforate rectum: a new surgical technique. Med J Aust 1953;1:202–3.
Stephens FD, Smith ED. Anorectal malformations in children. Chicago: Yearbook, 1971.
deVries PA, Peña A. Posterior sagittal anorectoplasty. J Pediatr Surg 1982;17:638–43.
Iwai N, Yanagihara J, Tokiwa K,et al. Results of surgical correction of anorectal malformations: a 10–30 year follow-up. Ann Surg 1988;207:219–22.
Ditesheim JA, Templeton JM Jr. Short-termversus long-term quality of life in children following repair of high imperforate anus. J Pediatr Surg 1987;22:581–7.
Wang CL, Li Z, Hou HS, Wang HZ. The anatomical observation on the pelvic of anorectal anomaly. Chin J Pediatr Surg 1983;4:65–7.
Li L, Li Z, Hou HS, Wang LY, Wang HZ. Sensory nerve endings in the puborectalis and the anal region: normal findings in newborn and changes in anorectal anomaly. J Pediatr Surg 1990;25:658–64.
Li L, Li Z, Wang LY, Xiao FD. Anorectal anomaly: neuropathological changes in the sacral spinal cord. J Pediatr Surg 1993;28:880–5.
Li L, Li Z, Wang LY, Hou HX. Motor nerve ending in the puborectalis and the external anal sphincter of anorectal anomalies. Chin J Pediatr Surg 1991;12:89–90.
Pena A, deVries PA. Posterior sagittal anorectoplasty: important technical considerations and new applications. J Pediatr Surg 1982;17:796–811.
Smith ED. The bath water needs changing, but don't throw out the baby: an overview of anorectal anomalies. J Pediatr Surg 1987;22:335–48.
Sonnino RE, Reinberg O, Bensoussan AL, Laberge JM, Blanchard H. Gracilis muscle transposition for anal incontinence in children: long-term follow-up. J Pediatr Surg 1991;26:1219–23.
Chuzo N. The structure of the lung. Vol 2, Tokyo: Igaku Shoin, 1957:144.
Doherty MM, Suh TH, Alexander L. New modification of the benzidine stain for study of the vascular pattern of the central nervous system. Arch Neurol Psycheate 1938;40:158–60.
Somjen GG. Neurophysiology—the essential. Baltimore: Waverly Press, 1983:386.
Lui GW. Cell physiology. Beijing: Piking University Press, 1992:136.
Wilkie DR. Muscle. 2nd ed. London: Edward Arnold, 1976:33.
Schmalbruch H. The morphology of regeneration of skeletal muscle in the rat. Tissue Cell 1976;8:673–92.
Carlson BM. The regeneration of skeletal muscle—a review. Am J Anat 1987;137:119–49.
Rehbein F. Imperforate anus: experiences with abdomino-perineal and abdomino-sacroperineal pullthrough procedures. J Pediatr Surg 1967;2:99–105.
Mollard P, Marechal JM, de Beaujeu MJ. Surgical treatment of high imperforate anus with definition of the puborectalis sling by an anterior perineal approach. J Pediatr Surg 1978;13:499–504.
Li L, Zang JZ, Lui GW, He GR, Lui XH. Tension-stress effects on the growth of the external anal sphincter. Clin J Surg 1995;33:123–6.