Anorectal Anomalies

Abstract

Anorectal malformations are congenital defects that present as a spectrum. In one extreme are malformations with the necessary anatomic structures to undergo a successful surgical reconstruction and have excellent functional results for bowel, urinary, and sexual function. On the other extreme of the spectrum, we see devastating malformations, with severe anatomic deficiencies, which will have serious consequences for life. Based on the follow-up of more than 3000 cases, we can now determine the future functional prognosis in a fairly accurate way during the first 72 h of life, based on a few relatively simple tests. Traditionally, anorectal malformations have been classified into three categories: “High,” “Intermediate,” and “Low.” Since 1980, with the advent of the posterior sagittal approach, it has been possible to see the intrinsic anatomy of these malformations directly and has become evident that this classification was misleading and useless. The new classification is based on therapeutic and prognostic factors, which means that each defect has a specific treatment and a specific functional prognosis. In addition to the specific type of malformation, it is now recognized that the characteristics of the sacrum, measured in an objective manner (sacral ratio), have an enormous influence on the functional prognosis. It is also recognized that the presence of a spinal defect called tethered cord influences the functional prognosis, although not as much as the sacrum. The field of fetal medicine and surgery has been progressing rapidly; we can now detect the most serious congenital anorectal, gynecologic, and urologic malformations in utero. In some specific cases, it is possible to surgically intervene, before the delivery, draining a massively distended vagina to avoid the demise of the baby. In addition, the early diagnosis allows the parents to make important decisions, including the need to deliver the baby in a specialized center to offer him (her) the best possible management. Modern imaging technology (MRI, Rotational CT Scan) allows us to make more accurate diagnoses, which helps in planning the surgical approach and detecting anatomic problems during the long-term follow-up of these patients. The MRI has also a big impact in re-defining the traditional anatomic concepts of the anatomy of the sphincters in normal individuals and patients with malformations. The laparoscopic approach to repair anorectal malformations that traditionally required an abdominal intervention, nowadays allows the repair of those defects in a minimally invasive fashion with many advantages for the patient. We have learned a lot about the importance of detecting and adequately treating associated malformations, including mainly urologic, orthopedic, neurosurgical, gastrointestinal, and cardiac. This encouraged us to create multidisciplinary centers to offer a more comprehensive management to our patients. The long-term follow-up of patients came with a very important revelation: children born with these defects become adults and continue suffering from diverse colorectal, urologic, and gynecologic consequences; when they look for help they feel desolated because they perceive that adult specialists do not know much about these defects. A new concept emerged: “Transitional Care.” It is a model of care that allows pediatric surgeons to interact with their adult specialists, to provide the best possible care to adults born with anorectal malformations. The recognition that at least 25% of all patients born with anorectal malformations, under the best circumstances, suffer from total fecal incontinence lead to the implementation of a Bowel Management Program, designed to improve the quality of life of those patients, by keeping them artificially clean in their underwear. Rectal mucosal prolapse is one of the most common consequences of the treatment of anorectal malformations. A recently described, new surgical approach to this problem is giving very impressive results.