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Journal of Magnetic Resonance Imaging :... Oct 2019The normal function of the anal sphincter complex is crucial for quality of life, as it is the mechanism by which fecal continence is maintained. Additionally, the anal... (Review)
Review
The normal function of the anal sphincter complex is crucial for quality of life, as it is the mechanism by which fecal continence is maintained. Additionally, the anal sphincter complex is an integral part of the coordinated effort of defecation. As imaging plays an important role in assessment of pathologic conditions involving the anal region, understanding the normal anatomy of the anal sphincter complex is important for correct image interpretation and accurate diagnosis. This review discusses the anatomy and function of the anal sphincter complex, important technical considerations for MRI, and various inflammatory, infectious, and neoplastic processes, as well as pathologic structural conditions that affect the anal region. Level of Evidence: 5 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019;50:1018-1032.
Topics: Anal Canal; Anus Diseases; Humans; Magnetic Resonance Imaging
PubMed: 31115134
DOI: 10.1002/jmri.26776 -
Diseases of the Colon and Rectum Jun 2011Anal manometry is routinely used in the assessment of the anal sphincters in patients with fecal incontinence or suspected sphincter injury. Such physiological... (Review)
Review
BACKGROUND
Anal manometry is routinely used in the assessment of the anal sphincters in patients with fecal incontinence or suspected sphincter injury. Such physiological information is complementary to the anatomical assessment provided by anal endosonography. The evolution of 3-dimensional anal endosonography provides more diagnostically useful information in complex cases. Vector volume manometry has been developed to give a 3-dimensional view of the anal sphincters.
OBJECTIVE
We reviewed the published literature on this technique, with the intention of deriving a system of standardization based on the published literature and to summarize the derivation and physiological meaning of the parameters measurable by vector volume studies, as well.
DATA SOURCES
We undertook a MEDLINE search using the terms "vector volume" or "vector manometry" and "anal canal." We also reviewed further publications found from references cited in the original articles identified from the above search.
STUDY SELECTION
Only English language articles of studies performed on humans were reviewed.
INTERVENTION
Anal canal vector volume manometry was the intervention.
RESULTS
With the development of automated puller systems and associated software, parameters such as total vector volume, maximum pressure, mean pressure, anal canal symmetry, anal canal length, and the length of the high-pressure zone can be readily calculated.
LIMITATIONS
There are conflicting studies related to the clinical value of both anal manometry and vector volume manometry, in part, because of the lack of standardization of equipment and technique.
CONCLUSIONS
The vector volume parameters have been shown to correlate with both imaging results and incontinence scores with automated puller systems. The clinical utility of vector volume manometry would be improved further by the standardization of equipment and technique. The main clinical utility may lie in the treatment selection and preoperative assessment of patients awaiting surgery for anal pathology that has yet to be evaluated.
Topics: Anal Canal; Endosonography; Humans; Manometry
PubMed: 21552063
DOI: 10.1007/DCR.0b013e3182113be7 -
Medicina (Kaunas, Lithuania) Nov 2021Anal canal duplication (ACD) is a very rare condition, diagnosed and treated mostly in childhood. Less than 90 cases have been reported in the literature so far. We are...
Anal canal duplication (ACD) is a very rare condition, diagnosed and treated mostly in childhood. Less than 90 cases have been reported in the literature so far. We are presenting a case of a young woman who underwent surgical excision of the duplication when she was 27 years old. The patient was unaware of her condition and was referred from a gynaecological office to the surgical department with a history of perianal discomfort and mucus discharge. Local examination showed an external orifice posterior to the anal opening, on the median line, which had the macroscopic appearance of a secondary anal orifice. The opening was about 0.5 cm in diameter. Exploration of the tract revealed a length of about 4 cm. MRI described the aforementioned tract, parallel to the anal canal, with no other anomalies mentioned. Under spinal anesthesia, with the patient in jackknife position, the accessory anal canal was surgically excised. The pathology report showed the presence of smooth muscle fibers and typical anal glands in the specimen. After a five-year follow-up, the patient showed no recurrence or any other related local symptoms. Absence of perianal abscess from the patient history, along with the macroscopic aspect of the opening similar to a secondary anal orifice on the midline, should raise the suspicion of ACD. Due to the lack of bothersome symptomatology, the patient did not seek any special investigations for her condition until she was in her late twenties. ACD is a very rare condition in adults that might pass unnoticed, but a midline opening posterior to the anus should always raise the suspicion of a secondary anal canal. Surgery is the only cure for this condition with good results after a proper pre-operative workout to reveal others simultaneous malformations.
Topics: Abscess; Adult; Anal Canal; Female; Humans; Magnetic Resonance Imaging; Perineum; Rare Diseases
PubMed: 34833422
DOI: 10.3390/medicina57111205 -
The Surgical Clinics of North America Feb 2010The rectum and anal canal form the last portion of the gastrointestinal tract. The rectum serves as a reservoir for fecal contents, and the anal canal regulates...
The rectum and anal canal form the last portion of the gastrointestinal tract. The rectum serves as a reservoir for fecal contents, and the anal canal regulates continence and defecation via synchronization of events regulated by complex interactions between sympathetic and parasympathetic nerves, striated and smooth muscle, and environmental factors. Normal function can be compromised by various pathologies. Investigation into these pathologies includes a detailed history and thorough physical exam and can be augmented by a number of different studies, including manometry, electromyelography, defecography, nerve stimulation, and compliance. Some of these techniques have incorporated the use of ultrasound and magnetic resonance imaging.
Topics: Anal Canal; Fecal Incontinence; Humans; Mucous Membrane; Muscle, Striated; Pelvic Floor; Rectum
PubMed: 20109629
DOI: 10.1016/j.suc.2009.09.001 -
Pediatric Surgery International Aug 2021Anal canal duplication is a rare malformation characterized by a second perineal opening positioned behind the anus, which is generally observed at 6 o'clock in the...
PURPOSE
Anal canal duplication is a rare malformation characterized by a second perineal opening positioned behind the anus, which is generally observed at 6 o'clock in the lithotomy position. The purpose was to describe six new cases of anal canal duplication (in addition to our previously reported series of six patients) with the aim of providing further clinical information about this anomaly.
METHODS
We described 6 new cases of anal canal duplication in terms of symptoms, anatomical disposition, imaging results, and histopathology. Clinical details of these cases and those already reported (n = 12) were summarized and compared to existing literature.
RESULTS
A total of 12 cases were reported over 34 years. 17% of the patients were male, constituting the only subgroup to present a communication with the digestive tract. A single patient, diagnosed at 12 years, was symptomatic. Half of the patients had at least one associated malformation. All patients underwent surgery, either with a posterior sagittal or perineal approach.
CONCLUSION
Diagnosis of anal canal duplication should be suspected when a perineal opening positioned behind the anus is present, and necessitates further exploration by a comprehensive clinical examination and imaging. Surgery is always required, typically performed via a posterior sagittal approach. The postoperative course is usually uncomplicated.
Topics: Anal Canal; Child; Child, Preschool; Female; Humans; Infant; Magnetic Resonance Imaging; Male; Perineum; Postoperative Period
PubMed: 33900436
DOI: 10.1007/s00383-021-04910-5 -
The Surgeon : Journal of the Royal... Aug 2017To summarise current knowledge of Internal anal sphincter. (Review)
Review
OBJECTIVE
To summarise current knowledge of Internal anal sphincter.
BACKGROUND
The internal anal sphincter (IAS) is the involuntary ring of smooth muscle in the anal canal and is the major contributor to the resting pressure in the anus. Structural injury or functional weakness of the muscle results in passive incontinence of faeces and flatus. With advent of new assessment and treatment modalities IAS has become an important topic for surgeons. This review was undertaken to summarise our current knowledge of internal anal sphincter and highlight the areas that need further research.
METHOD
The PubMed database was used to identify relevant studies relating to internal anal sphincter.
RESULTS
The available evidence has been summarised and advantages and limitations highlighted for the different diagnostic and therapeutic techniques.
CONCLUSION
Our understanding of the physiology and pharmacology of IAS has increased greatly in the last three decades. Additionally, there has been a rise in diagnostic and therapeutic techniques specifically targeting the IAS. Although these are promising, future research is required before these can be incorporated into the management algorithm.
Topics: Anal Canal; Fecal Incontinence; Humans
PubMed: 27881288
DOI: 10.1016/j.surge.2016.10.003 -
Pediatric Surgery International May 2017Anal canal duplication (ACD) is the rarest of gastrointestinal duplications. Few cases have been reported. Most cases present as an opening in the midline, posterior to...
Anal canal duplication (ACD) is the rarest of gastrointestinal duplications. Few cases have been reported. Most cases present as an opening in the midline, posterior to the normal anus. The aim of our revision is to contribute with eight new cases, some of them with unusual presentations: five presented as the typical form, one with a perianal nodule, and two presented as two separate orifices (anal canal triplication). Complete excision was performed in all patients with no complications. ACD is the most distal and the least frequent digestive duplication. Its treatment should be surgical excision, to avoid complications such as abscess, fistulization, or malignization. Anal canal triplication has never been described before.
Topics: Anal Canal; Child; Child, Preschool; Female; Humans; Infant; Male
PubMed: 28255623
DOI: 10.1007/s00383-017-4074-7 -
The Surgical Clinics of North America Feb 2010Anal stenosis occurs most commonly following a surgical procedure, such as hemorrhoidectomy, excision and fulguration of anorectal warts, endorectal flaps, or following... (Review)
Review
Anal stenosis occurs most commonly following a surgical procedure, such as hemorrhoidectomy, excision and fulguration of anorectal warts, endorectal flaps, or following proctectomy, particularly in the setting of mucosectomy. Patients who experience anal stenosis describe constipation, bleeding, pain, and incomplete evacuation. Although often described as a debilitating and difficult problem, several good treatment options are available. In addition to simple dietary and medication changes, surgical procedures, such as lateral internal sphincterotomy or transfers of healthy tissue are other potentially good options. Flap procedures are excellent choices, depending on the location of the stenosis and the amount of viable tissue needed. This article presents the definition, pathophysiology, diagnosis, and treatment of anal stenosis, and methods to prevent it.
Topics: Anal Canal; Constriction, Pathologic; Hemorrhoids; Humans; Physical Examination; Postoperative Complications; Surgical Flaps
PubMed: 20109638
DOI: 10.1016/j.suc.2009.10.002 -
Surgical Endoscopy Dec 2007Demonstrate precisely the anatomic configuration of the anal canal and the length and thickness of the anal sphincters using three-dimensional (3-D) anorectal...
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.
Topics: Anal Canal; Endosonography; Female; Humans; Imaging, Three-Dimensional; Male; Middle Aged; Prospective Studies; Sex Characteristics
PubMed: 17479327
DOI: 10.1007/s00464-007-9339-0 -
Gastroenterology Clinics of North... Mar 2001Anal fissure is a common condition, and although most are short-lived and heal spontaneously, those that persist and require intervention cause considerable morbidity in... (Review)
Review
Anal fissure is a common condition, and although most are short-lived and heal spontaneously, those that persist and require intervention cause considerable morbidity in an otherwise healthy young population. Traditionally, lateral internal sphincterotomy was the gold standard treatment for chronic fissures, but this procedure is associated with a risk of incontinence to some degree in 30% of patients. The discovery of pharmacologic agents that effectively cause a chemical sphincterotomy and heal most fissures has led to approximately two thirds of patients avoiding surgery. Topical 0.2% GTN ointment probably is the most widely used first-line treatment. Other drugs currently under investigation may offer effective treatment with fewer side effects. Another advantage of these novel treatments is that by acting through different pathways, they may be effective in the 30% of cases in which GTN fails, the risks associated with surgery may be avoided. Studies of botulinum toxin injection into the anal sphincter have reported excellent healing rates, although the procedure is more invasive, and patients may find it uncomfortable and less tolerable. Chemical sphincterotomy is particularly suitable in patients with associated inflammatory bowel disease, in whom sphincterotomy for anal fissure generally is contraindicated. When pharmacologic therapy fails or fissures recur frequently and patients have raised resting anal pressure, lateral internal sphincterotomy is the surgical treatment of choice. The results are satisfactory when patients are selected carefully and the incision is limited to the length of the fissure. When chemical sphincterotomy fails and resting anal pressures are not elevated, as is commonly the case with patients developing fissures postpartum, an advancement flap should be considered.
Topics: Anal Canal; Fissure in Ano; Humans
PubMed: 11394029
DOI: 10.1016/s0889-8553(05)70172-2