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Thrombosed hemorrhoid in 57-year-old man with acute lymphoblastic leukemia. Contrast-enhanced fat-suppressed T1-weighted TSE oblique coronal image shows thrombotic material in hemorrhoid as marked hypointensity (arrows) in the anal canal lumen. Asterisk indicates associated cellulitis in anodermal tissue in this neutropenic patient. LA levator ani muscle
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A broad spectrum of disease, from benign processes to life-threatening pathologies, can cause anal pain. MR imaging (MRI) has become increasingly widely used method over the past two decades for the evaluation of individuals with anorectal symptoms. Although imaging is rarely necessary to determine the etiology of the majority of cases, MRI is part...
Citations
... The most common anal canal pathology is perianal fistula by which the anal sphincters are usually breached in most of its types [2]. Traumatic anal canal conditions or surgical interventions can lead to anal sphincteric injuries which in turns lead to sphincteric weakness and fecal incontinence, identification of such injuries is crucial for selection of best therapeutic option for patients with continence problems [3]. Change of muscle thickness of anal sphincteric complex manifested either by muscle atrophy or muscle thickening as seen in hypertrophic myopathy of the IAS can result in defecatory problems as fecal incontinence or constipation, respectively [3]. ...
... Traumatic anal canal conditions or surgical interventions can lead to anal sphincteric injuries which in turns lead to sphincteric weakness and fecal incontinence, identification of such injuries is crucial for selection of best therapeutic option for patients with continence problems [3]. Change of muscle thickness of anal sphincteric complex manifested either by muscle atrophy or muscle thickening as seen in hypertrophic myopathy of the IAS can result in defecatory problems as fecal incontinence or constipation, respectively [3]. Many neoplastic conditions can involve the anal sphincteric complex and are either primarily from the anorectum or secondarily from anal canal metastasis or surrounding pelvic organs malignancies [4]. ...
... Anal sphincteric lesions were classified into: (A) fistula: The sphincteric interruption is identified as a fluid filled or fibrotic tract eliciting high T2/STIR or low T2/STIR, respectively, traversing through only the IAS only (intersphincteric fistula) or both IAS and EAS (trans-sphincteric) [2]. (B) Sphincteric injury: involving the IAS, EAS, or both anal sphincters can be either (i) defect: identified as discontinuity of muscle fibers or (ii) scar: identified by replacement of muscle by low signal scar tissue [3]. (C) Atrophy: identified by thinning out or fat replacement of the muscle. ...
Background
The anal sphincteric complex is formed by internal and external sphincters making two partially overlapping tubes around the anal canal. Anal sphincteric lesions represent a spectrum of entities with different patients’ presentations and surgical managements. Endoanal ultrasound has an increasing role in detection and evaluation of anal sphincteric lesions as compared to MRI of the anal canal. The aim of this work was to compare between the 3D EAUA and external phased array MRI in detection and evaluation of anal sphincteric lesions.
Results
There is almost perfect agreement of 97.92% ( Κ w = 0.972) between 3D EAUS and external phased array MRI in the detection of the internal anal sphincter lesions and fair agreement of 66.67% ( Κ w = 0.37) in the detection of the external anal sphincteric lesions.
Conclusions
3D EAUS and external phased array MRI are comparable imaging techniques in the detection of the internal anal sphincter lesions, while the MRI could detect more external sphincteric lesions than EAUS.
... 14). 45 ...
A variety of tumors involve the anal canal because the anal canal forms the transition between the digestive system and the skin, and this anatomical region is made of a variety of different cells and tissues. Magnetic resonance imaging (MRI) is the modality of choice for diagnosis and local staging of the anal canal and perianal neoplasms. In this pictorial review, we demonstrate the MRI anatomy of the anal canal and perianal region and display the imaging spectrum of tumors in the region along with an overview of its management. Imaging appearances of many tumorlike lesions that can cause diagnostic dilemmas are also demonstrated with pointers to differentiate between them.
... The diagnosis was challenging because it was difficult to diagnose an extreme horseshoe fistula on clinical examination alone. MRI, primarily the axial (transverse) section, made these fistulae's diagnosis relatively easy [ Figures 1-4] [8][9][10][11]. Needless to say, the proper diagnosis was mandatory for successful treatment. A missed circumferential tract would have led to a recurrence. ...
Objectives:
Extreme horseshoe anal fistulas are rare, and there are little data on the diagnosis and management of these fistulas.
Materials and methods:
Patients with horseshoe anal fistula, in which the fistula tract encircled more than 75% of the anal circumference were included in the study. All patients were assessed by a preoperative magnetic resonance imaging (MRI). The patients were managed by a sphincter-sparing procedure. The continence was evaluated by an objective continence scoring system (Vaizey's scores).
Results:
1059 anal fistula patients were operated on over 7-years with a median follow-up of 36 months (range: 5-79 months). There were 47/1059 (4.4%) patients with extreme horseshoe anal fistulas. In 4/47 patients, the fistulas were complete circumanal (encircling anal canal completely). The mean age was 39.5 ± 10.9 years, M/F-41/6. The fistula was supralevator in 12/47 (25.5%), had an associated abscess in 28/47 (59.6%), and was recurrent in 33/47 (70.2%) patients. The tracts were intersphincteric in 27/47, transsphincteric in 2/47, and both (intersphincteric and transsphincteric) in 18/47 patients. All patients (n = 47) were managed by a sphincter-sparing procedure. Four patients were lost to follow-up. The fistula healed completely in 34/43 (79%) patients. There was no significant difference between preoperative and postoperative Vaizey's continence scores 0.031 ± 0.17 and 0.033 ± 0.18 respectively (P=0.90, Mann-Whitney U-test).
Conclusion:
Extreme horseshoe fistulas are rare, with an incidence of about 4% (in a referral practice). The missed diagnosis of circumferential tracts could lead to a recurrence. MRI was pivotal to confirm the diagnosis. Proper identification and management of internal opening and adequate drainage of all tracts were crucial for successfully treating extreme horseshoe fistulas.
... Radiological assessment of anal sphincter involvement MRI and TRUS are the best modalities available to assess the amount of sphincter involvement. 6,7,16,17 The importance of this evaluation cannot be overemphasized, as this plays a major role in deciding the proper management of fistulae and is the prime point in grading fistulae by the latest classifications. 3,18 It is not difficult to understand that evaluation of sphincter involvement especially of the external sphincter, is not possible by clinical examination in all cases. ...
Anal fistulae can be a very difficult disease to manage. The management of complex fistulae is even more challenging. The risk to the fecal continence mechanism due to damage to the anal sphincters and refractoriness to the treatment (high recurrence rate) pose the two biggest challenges in the management of this disease. Apart from these, there are several other challenges in the treatment of complex fistulae. The intriguing and uphill task is that satisfactory solutions to most of these challenges are still not known, and there is hardly any consensus on whatever treatment solutions are available. To summarize, there is no gold-standard treatment available for treating complex anal fistulae, and the search for a satisfactory treatment option is still on. In this review, the endeavor has been to discuss and highlight recent path-breaking updates in the management of complex anal fistulae.
... Magnetic resonance imaging (MRI) is considered the most accurate preoperative technique for classification of anal fistula and is useful for evaluation of the primary track, abscesses, and extensions to adjacent tissues [5][6][7] . More importantly, it is useful to guide clinicians in determining the extent of surgical resection. ...
Background:
Magnetic resonance imaging (MRI) is currently the standard investigation for suspected perianal diseases. Carcinoma arising from anal fistula is very rare, and early diagnosis is often difficult.
Aim:
To describe and summarize the MRI findings of carcinoma arising from anal fistula.
Methods:
In this retrospective study, records of ten patients diagnosed with carcinoma arising from anal fistula and confirmed by surgery (n = 7) or biopsy (n = 3) between June 2006 and August 2018 were analyzed. All patients underwent preoperative pelvic MRI. Morphologic features, signal characteristics, fistula between the mass and the anus, contrast enhancement of mass, signal and enhancement of peritumoral areas, and regional lymphadenopathy were assessed.
Results:
All ten tumors were solitary (8 mucinous adenocarcinomas and 2 adenocarcinomas). The maximum diameter of the tumors ranged from 3.4 cm to 12.4 cm (median: 4.15 cm; mean: 5.68 cm). Eight patients had a fistula between the mass and the anus. Contrast enhancement of the peritumoral areas was noted in three (3/5) patients. Perirectal or inguinal lymphadenopathy was noted in seven patients. Most lesions of mucinous adenocarcinoma were multiloculated and cauliflower-like, with a thin capsule and focally unclear boundary. They were markedly hyperintense on fat-suppressed T2WI, slightly hyperintense with focal hyperintensity on diffusion-weighted imaging (DWI), and hyperintense with focal hypointensity on apparent diffusion coefficient (ADC) map, with progressive mesh-like contrast enhancement. Adenocarcinomas had an infiltrative margin without a capsule and appeared heterogeneously hyperintense or slightly hyperintense on fat-suppressed T2WI, hyperintense on DWI, and hypointense on ADC map, with persistent heterogeneous enhancement.
Conclusion:
Our study highlighted several characteristic and potentially helpful MRI findings to diagnose carcinomas arising from anal fistula.
The evaluation of the anal canal is often necessary for Crohn’s disease patients considering its frequent involvement. The typical pathologic conditions are represented by fistulas and abscesses. MRI of the anal region must be performed through an encoded protocol consisting of T2-weighted, T1-weighted before and after Gadolinium injection and diffusion-weighted scans. Acquisition planes must be set according to the longitudinal and axial axis of the canal. The latter parameters are of the utmost importance not only for the radiological assessment but also in case of surgical planning. Nevertheless, several conditions of various nature, related or not to Crohn’s disease, can be assessed through this technique, from inflammation to malignancies.
Conventionally, in the pathophysiology of anal fistulas, there is only one space considered significant for the spread of pus in the sphincter complex: the intersphincteric space. However, with increasing experience in the high-resolution MRI, and more focus being given on managing fistulas through the intersphincteric space, two additional pathways of fistula spread have been identified. First is a newly described space labelled as the outer-sphincteric space. Second is a known anatomical space (inner intersphincteric space), but this space was considered as irrelevant from the point of view of fistula spread. The conventional intersphincteric space is present in between these two spaces and is referred as ‘middle intersphincteric space’ in this paper. These three distinct spaces have significant clinical implications as the pattern of spread of pus is quite different in each space, and the management also differs for fistula tract in each of these spaces.
Anal pain is a potentially highly debilitating symptom. It is frequently considered as an idiopathic problem but in some cases it could be due to nonfunctional or organic diseases. The manuscript analyzes the most common causes of nonfunctional and functional chronic anal pain, highlighting false beliefs and functional implications. Hemorrhoids rarely are painful unless they became complicated and develop thrombosis or necrosis. Instead, hemorrhoidectomy could develop easily persistent anal pain. The most common cause of anal pain is anal fissure. Also cryptoglandular anal abscess or anal stricture can lead to pain. Chronic anal pain is usually connected with an important anal resting and involuntary hypertonia and leads to a difficult evacuation. Other causes of chronic nonfunctional anal pain are considered and discussed. Rome IV criteria divide anorectal functional pains into proctalgia fugax, unspecified anorectal pain, and levator ani syndrome. These disturbances are examined with their functional, diagnostic, and psychological implications.
Puntos para una lectura rápida
• La incontinencia fecal es un síntoma incapacitante que a menudo asocia aislamiento social, pérdida de autoestima y deterioro en la calidad de vida.
• El aumento en la tasa de detección mediante la entrevista dirigida y el conocimiento de las posibilidades terapéuticas debe ser un objetivo en el ámbito de la atención primaria.
• La consistencia y frecuencia de las deposiciones de los pacientes que lo padecen es uno de los factores más relacionados con la severidad de los síntomas.
• El tratamiento médico conservador consigue altas tasas de mejoría sintomática y debe ser ofrecido como primera línea terapéutica.
