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Originally published as JCO Early Release 10.1200/JCO.2008.20.9296 on January 21 2009 © 2009 American Society of Clinical Oncology.
In ReplyDepartment of Surgery, Leiden University Medical Center, Leiden, the Netherlands
Department of Anatomy and Embryology, Academic Medical Center, Amsterdam, the Netherlands
Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, the Netherlands
Department of Surgery, Leiden University Medical Center, Leiden, the Netherlands We would like to thank Kinugasa and Sugihara for their interest in our study.1 First of all, Japanese investigators must be credited for their meticulous description of the fascial structures surrounding the mesorectum.2–6 In our investigation, we did not differentiate between the visceral and prehypogastric nerve fascia. Indeed, the dissection plane described by Kinugasa et al2,3 may be safer with respect to damage to the levator ani nerve (LAN), which might explain the good functional results achieved in Japan. However, these good functional results may also be explained by the low body fat percentage of the Japanese population, which makes it easier to identify and preserve the nerves, compared with the European population. Moreover, no large multicenter trials similar to the Dutch total mesorectal excision (TME) trial,7 in which functional outcome was assessed extensively, have been conducted in Japan. Therefore, the dysfunction rate in daily practice in Japan is still unknown. Kinugasa and Sugihara state that surgical separation of structures is difficult at the most distal part of the rectum, where the smooth muscle containing fascia of the levator ani muscle merges into the anorectal muscle. The authors are dubious that injury at this level could induce functional disorders. In our study, we do not describe surgical dissection and nerve damage at such a low level, but rather at a level approximately 2 cm cranial from the entrance of the rectum through the levator ani muscle. In our investigation, it was evident that the LAN is especially at risk at that level, because the mesorectal fascia and the parietal fascia become inseparable, and the parietal fascia must be removed from the surface of the pelvic floor muscles to preserve the mesorectal package. Therefore, the LAN is in close proximity to the surgical dissection plane. In addition to damage to the LAN at a low level (ie, 6 cm cranial to the anal verge), we found an indication that nerve damage might also occur at a higher level. The anatomic origin of the LAN is closely related to the origin of the pelvic splanchnic nerves. Thus nerve damage at this level holds the risk of combined disruption of the LAN and the pelvic splanchnic nerves. Incontinence problems (possibly indicating a denervated pelvic floor) were associated with difficulty in bladder emptying, suggesting damage to the LAN at its origin, at the level at which the pelvic splanchnic nerves also arise (ie, nerves S3-S4).1 Additional nerve damage at a more proximal level is also expected to occur frequently. Previous reports on the Dutch TME trial have suggested that nerve damage was probably underreported in the Dutch TME trial, and damage to the LAN was not reported, because this nerve was not addressed in this trial.8 However, high rates of erectile disorders and difficulty in bladder emptying (ie, damage to the pelvic splanchnic nerves or pelvic plexus), and ejaculatory disorders (ie, damage to the superior hypogastric plexus or hypogastric nerves) have been found.8,9 AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST The author(s) indicated no potential conflicts of interest. REFERENCES
1. Wallner C, Lange MM, Bonsing BA, et al: Causes of fecal and urinary incontinence after total mesorectal excision for rectal cancer based on cadaveric surgery: A study from the Cooperative Clinical Investigators of the Dutch total mesorectal excision trial. J Clin Oncol 26:4466–4472, 2008. 2. Kinugasa Y, Murakami G, Suzuki D, et al: Histological identification of fascial structures posterolateral to the rectum. Br J Surg 94:620–626, 2007.[CrossRef][Medline] 3. Kinugasa Y, Murakami G, Uchimoto K, et al: Operating behind Denonvilliers' fascia for reliable preservation of urogenital autonomic nerves in total mesorectal excision: A histologic study using cadaveric specimens including a surgical experiment using fresh cadaveric models. Dis Colon Rectum 49:1024–1032, 2006.[CrossRef][Medline] 4. Yabuki Y, Sasaki H, Hatakeyama N, et al: Discrepancies between classic anatomy and modern gynecologic surgery on pelvic connective tissue structure: Harmonization of those concepts by collaborative cadaver dissection. Am J Obstet Gynecol 193:7–15, 2005.[CrossRef][Medline] 5. Arakawa T, Murakami G, Nakajima, et al: Morphologies of the interfaces between the levator ani muscle and pelvic viscera, with special reference to muscle insertion into the anorectum in elderly Japanese. Anat Sci Int 79:72–81, 2004.[CrossRef][Medline] 6. Sato K, Sato T: The vascular and neuronal composition of the lateral ligament of the rectum and the rectosacral fascia. Surg Radiol Anat 13:17–22, 1991.[CrossRef][Medline] 7. Kapiteijn E, Marijnen CA, Nagtegaal ID, et al: Preoperative radiotherapy combined with total mesorectal excision for resectable rectal cancer. N Engl J Med 345:638–646, 2001. 8. Lange MM, Maas CP, Marijnen CA, et al: Urinary dysfunction after rectal cancer treatment is mainly caused by surgery. Br J Surg 95:1028; 2007. 9. Marijnen CA, van de Velde CJ, Putter H, et al: Impact of short-term preoperative radiotherapy on health-related quality of life and sexual functioning in primary rectal cancer: Report of a multicenter randomized trial. J Clin Oncol 23:1847–1858, 2005.
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Copyright © 2009 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
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