Materiały źródłowe

• #1 Anal Fissures – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK526063/

  An anal fissure is a superficial tear in the skin distal to the dentate line. Anal fissures are common in those with a history of constipation or hard stools, low fiber diet, trauma, and previous anal surgery. […] The majority of acute anal fissures are thought to be due to the passage of hard stools, sexually transmitted infection, or anal injury due to penetration. A chronic anal fissure typically is a recurrence of an acute anal fissure. It is thought to be also caused by the passage of hard stools against an elevated anal sphincter tone pressure, with symptoms lasting greater than 6 weeks. […] The anoderm refers to the epithelial component of the anal canal. The location is inferior to the dentate line. It is a very sensitive area to microtrauma and can tear with repetitive trauma or increased pressure. The high pressures in this area can result in delayed healing secondary to ischemia.

• #1 Anal Fissure: Practice Essentials, Anatomy, Pathophysiology and Etiology

  https://emedicine.medscape.com/article/196297-overview

  The exact etiology of anal fissures is unknown, but the initiating factor is thought to be trauma from the passage of a particularly hard or painful bowel movement. […] Low-fiber diets (eg, those lacking in raw fruits and vegetables) are associated with the development of anal fissures. […] Initial minor tears in the anal mucosa due to a hard bowel movement probably occur often. In most people, these heal rapidly without long-term sequelae. In patients with underlying abnormalities of the internal sphincter, however, these injuries progress to acute and chronic anal fissures. […] The most commonly observed abnormalities are hypertonicity and hypertrophy of the internal anal sphincter, leading to elevated anal canal and sphincter resting pressures. […] The posterior anal commissure is the most poorly perfused part of the anal canal. In patients with hypertrophied internal anal sphincters, this delicate blood supply is further compromised, thus rendering the posterior midline of the anal canal relatively ischemic.

• #1 Innovations in chronic anal fissure treatment: A systematic review

  https://www.wjgnet.com/1948-9366/full/v2/i7/231.htm

  A chronic anal fissure is a common perianal condition. […] The current understanding is that there is an initiating trauma to the anal canal caused by the passage of hard stools or diarrhoea episodes. In susceptible individuals with internal sphincter hypertonia, there is little or no healing of the anal mucosa after the initial trauma. This is due to ischemia of the tissues around the anal fissure, especially the posterior commissure, by compression of the inferior rectal arteries from the internal sphincter. […] The first factor is the presence of persistently high basal internal sphincter tone in the majority of individuals with chronic anal fissures. […] The second factor is the presence of ischemia causing non-healing of the anal fissure. […] In addition to the above two factors, it has been postulated that the pathogenesis of posterior anal fissures is contributed by the repeated preferential over-stretching of the posterior anal sphincter complex and perineum. […] A small subgroup of patients (about 11% of chronic anal fissure patients) develops chronic anal fissures after child delivery.

• #1 Anal fissure – Australian Prescriber

  https://australianprescriber.tg.org.au/articles/anal-fissure.html

  An anal fissure is a longitudinal tear or defect in the skin of the anal canal distal to the dentate line. The classification of anal fissures is based on causative factors. […] Primary fissures are typically benign and are likely to be related to local trauma such as hard stools, prolonged diarrhoea, vaginal delivery, repetitive injury or penetration. Secondary fissures are found in patients with previous anal surgical procedures, inflammatory bowel disease (e.g. Crohns disease), granulomatous diseases (e.g. tuberculosis, sarcoidosis), infections (e.g. HIV/AIDS, syphilis) or malignancy. […] The pathophysiology of anal fissures is not entirely clear. It is probable that an acute injury leads to local pain and spasm of the internal anal sphincter. This spasm and the resulting high resting anal sphincter pressure leads to reduced blood flow and ischaemia, and poor healing. Unless this cycle is broken the fissure will persist.

• #1 Anal fissure – Wikipedia

  https://en.wikipedia.org/wiki/Anal_fissure

  Most anal fissures are caused by stretching of the anal mucous membrane beyond its capability. […] The most common cause of non-healing is spasming of the internal anal sphincter muscle which results in impaired blood supply to the anal mucosa. The result is a non-healing ulcer, which may become infected by fecal bacteria. […] In older adults, anal fissures may be caused by decreased blood flow to the area. […] Some sexually transmitted infections can promote the breakdown of tissue resulting in a fissure: syphilis, herpes, chlamydia and human papilloma virus. […] Other common causes of anal fissures include: childbirth trauma in women, anal sex, Crohn’s disease, ulcerative colitis, and poor toileting in young children. […] Surgical treatment, under general anaesthesia, is either anal stretch (Lord’s operation) or lateral sphincterotomy where the internal anal sphincter muscle is incised. Both operations aim to decrease sphincter spasming and thereby restore normal blood supply to the anal mucosa.

• #1 Anal fissure

  https://pmc.ncbi.nlm.nih.gov/articles/PMC4816871/

  The pathophysiology of anal fissures is not entirely clear. It is probable that an acute injury leads to local pain and spasm of the internal anal sphincter. This spasm and the resulting high resting anal sphincter pressure leads to reduced blood flow and ischaemia, and poor healing. Unless this cycle is broken the fissure will persist. […] It is hypothesised that this predilection for the posterior midline may occur because this portion of the anal canal is poorly perfused. Anterior anal fissures affect approximately 10% of patients and may have a different pathophysiology. They are associated with younger, mostly female, patients often with injury to or dysfunction of the external anal sphincter. […] A small study of completely excised anal fissures found no underlying microscopic features of inflammation in most of the patients. Further, these fissures or defects showed little in the way of ulcer characteristics and appeared to be more consistent with unstable anodermal scar tissue. Additional research is needed to understand the temporal relationship between poor perfusion and lack of inflammation, as well as to identify the best terminology to describe these lesions.

• #1 Anal Fissure: Practice Essentials, Anatomy, Pathophysiology and Etiology

  https://emedicine.medscape.com/article/196297-overview

  Pain accompanies each bowel movement as this raw area is stretched and the injured mucosa is abraded by the stool. The internal sphincter also begins to spasm when a bowel movement is passed. This spasm has two effects: First, it is painful in itself, and second, it further reduces the blood flow to the posterior midline and the anal fissure, contributing to the poor healing rate.

• #1 Identifying the best therapy for chronic anal fissure

  https://www.wjgnet.com/2150-5349/full/v2/i2/9.htm

  Chronic anal fissure (CAF) is a painful tear or crack which occurs in the anoderm. […] This article will examine the method of CAF pathogenesis and consider the decision making process and the appropriate application of therapy. […] Anal fissure has been associated with increased anal tone for many years. This has been substantiated by a highly successful surgical treatment for anal fissure – internal sphincterotomy which reduces resting anal pressure. […] These facts constitute the logical basis for the explanation that microtrauma of the anoderma and AF cause anal pain which provokes a spasm of the IAS and a high anal pressure. This, in turn, leads to a reduction in anodermal perfusion. Ischemia in the fissure region ensues. […] It is widely accepted that the reduction of anal pressure by LIS is associated with an improvement in anodermal perfusion; therefore, we conclude that this surgical procedure promotes anal fissure healing.

• #1 Surgery for Anal Fissure: Background, Indications, Contraindications

  https://emedicine.medscape.com/article/1582334-overview

  An anal fissure is a tear of the squamous epithelium that usually extends from the dentate line to the anal verge. In 90% of cases, the fissure manifests as a painful linear ulcer lying in the posterior midline of the anal canal. […] The exact cause of anal fissures is unknown. Historically, an anal fissure was thought to be a result of mechanical trauma caused by a hard stool tearing the anoderm as it was passed. […] In addition, anal fissures have been associated with increased anal tone for many years. A proposed mechanism for increased anal tone in a study by Lund showed reduced nitric oxide (NO) synthase and, consequently, decreased nitric oxide synthesis in the internal sphincters of patients with anal fissures as compared with control subjects. NO has been known to facilitate smooth-muscle relaxation of the internal anal sphincter.

• #1 Anal fissure • New Medicine 1/2005 • Czytelnia Medyczna BORGIS

  https://www.czytelniamedyczna.pl/1031,anal-fissure.html

  Anal fissure is a benign condition of the anus, most commonly found in the posterior commissure, causing severe rectal pain and bleeding. […] The current approach shows that the condition is caused by an impaired anorectal motor function manifested by, e.g., an exaggerated resting sphincter spasm, a paradoxical sphincter spasm on defecation. […] The theory presented by Gibbons and Read assumes that the fissure formation is mainly due to an impaired motor function of the sphincters. An inflammatory aspect is also worth considering it accounts for an increased prevalence of anal fissure in patients with persistent diarrhoea.

• #1 Chronic Anal Fissure | Abdominal Key

  https://abdominalkey.com/chronic-anal-fissure-2/

  Manometric studies have shown that up to 50% of patients with CAF do not have increased anal pressures. These patients are typically women with anterior midline CAF, which, in small studies, has been associated with vaginal delivery, external sphincter injury/dysfunction, rectocele, and rectoanal intussusception.

• #1 Surgery for Anal Fissure: Background, Indications, Contraindications

  https://emedicine.medscape.com/article/1582334-overview

  Schouten et al proposed that anal fissures were ischemic ulcers and found that patients with anal fissures had significantly higher resting anal sphincter tone and decreased anodermal blood flow in comparison with healthy volunteers. Other studies confirmed that blood supply to the posterior midline of the anoderm is relatively poor when compared with blood supply to the other quadrants. […] This combination of increased tone and poor blood supply likely contributes to the relative ischemia of the posterior midline of the anoderm; however, not all patients with anal fissures have anal sphincter hypertrophy or insufficient blood supply to the anoderm.

• #1 +Bioline International Official Site (site up-dated regularly)

  https://www.bioline.org.br/request?hs07004

  The resting pressure in the anal canal is largely a function of the internal sphincter. The continuous partial contraction of the sphincter is due to an inherent myogenic tone and alpha adrenergic nerve mediated pathways. Patients with chronic anal fissure usually have a raised resting anal pressure due to hypertonicity of the internal sphincter. This compromises perfusion of the anal mucosa as the blood vessels supplying the distal anal canal traversing the internal sphincter en route to the anal mucosa may be compressed by the hypertonic muscle leading to chronic anal fissure. This is why chronic anal fissure has been described as an ischemic ulcer.

• #1 Anal Fissures – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK526063/

  It is well known that the most common location of an anal fissure is the posterior midline because this location receives less than half of perfusion compared to the rest of the anal canal. The perfusion of the anal canal has an inverse relationship to sphincter pressure. […] Other locations of anal fissures, such as lateral fissure, are indicative of an underlying etiology (HIV, tuberculosis, Crohn disease, ulcerative colitis, among others). The cause of this other location is not well known. Anterior fissures are rare and are associated with external sphincter injury and dysfunction.

• #1 Anal Fissure

  https://lacolon.com/patient-education/anal-fissure

  Anal fissures are a common problem, bringing many patients to the colorectal surgeons office with complaints of anal pain. […] Anorectal trauma secondary to the passage of diarrhea or a hard stool is the most common cause of an anal fissure. […] Increased resting internal anal sphincter pressure with resultant ischemia has been postulated to be the main factor in fissure persistence. Healing is slowed as the vascular supply to the local area is compromised by intense sphincter spasm. […] Angiographic studies have demonstrated that the posterior anal midline has the lowest tissue perfusion, consistent with the finding that this location is the most common fissure location. […] It is thought that nitroglycerin acts as a topical anal sphincter smooth muscle relaxant, enabling an increased blood flow to the injured anal area. The mechanism of action may be similar to its action on the coronary arteries during an episode of angina. […] Diltiazem is a calcium channel blocker and may serve to relax the anal sphincter in the same fashion as during its use in the treatment of hypertension or angina.

• #1 Evaluation of anal canal morphology with MRI in cases with anal fissure

  https://epos.myesr.org/poster/esr/ecr2015/C-1670

  Anal fissure is a vertical tear between dentate line and anocutaneous junction. It is located at the posterior midline in the %90 of the cases. One of the reasons of its presence at this location is that the superficial external anal sphincter gets far away from the anus and moves towards the coccyx at the posterior. This part which is called Minor triangle is unsupported and may be damaged during faeces passage. […] The increase of the traction angle (K angle) of the anal canal by the superficial external sphincter to the coccyx may expand the unsupported part (Minor triangle) of anal canal and may have a role in the pathogenesis of anal fissure. It has been thought that length of the anal canal may have a role in the pathogenesis of anal fissure. In the chronic cases, long-standing inflammatory reactions lead to…

• #1 The Italian Unitary Society of Colon-proctology (SIUCP: Società Italiana Unitaria di Colonproctologia) guidelines for the management of anal fissure | BMC Surgery | Full Text

  https://bmcsurg.biomedcentral.com/articles/10.1186/s12893-023-02223-z

  Anal fissure is a common proctologic disease, accounting for up to 10% of anorectal complaints in specialty clinics. […] The etiopathogenesis of the anal fissure is still unclear and probably recognizes a multifactorial origin. The fissure typically occurs after a trauma of the anoderm caused by passage of hard stool or by irritation of diarrhea. The higher prevalence of the posterior location could be explained by the greater mechanical stress caused by the anorectal angle posteriorly. According with studies showing an increased anal tone and a reduction in posterior anoderma vascular blood flow in patients with anal fissures, it has been speculated that the increased sphincter tone caused by the intense anal pain typical of fissuring, predisposes the mucosa to ischemia and impedes the healing of the fissure, generating a vicious cycle.

• #1 Anal fissure – Australian Prescriber

  https://australianprescriber.tg.org.au/articles/anal-fissure.html

  It is hypothesised that this predilection for the posterior midline may occur because this portion of the anal canal is poorly perfused. Anterior anal fissures affect approximately 10% of patients and may have a different pathophysiology. They are associated with younger, mostly female, patients often with injury to or dysfunction of the external anal sphincter. […] A small study of completely excised anal fissures found no underlying microscopic features of inflammation in most of the patients. Further, these fissures or defects showed little in the way of ulcer characteristics and appeared to be more consistent with unstable anodermal scar tissue. Additional research is needed to understand the temporal relationship between poor perfusion and lack of inflammation, as well as to identify the best terminology to describe these lesions.

• #1 Anal Fissure – an extensive update

  https://ppch.pl/seo/article/147879/en

  Madalinski and Kalinowski theorised that in chronic fissures, the stretchability of the anal sphincters is insufficient leading to eruption of tissue in the fissure region during defecation and these erupted tissues release vessel contraction mediators which have a tendency to arrest the healing process by interference with endothelial nitric oxide expression. […] The pathophysiology of anterior fissures may however be different than that of posterior fissures. […] The study showed that the anterior anal fissures are associated with occult external anal sphincter injury, lower maximum squeeze pressure and impaired external anal sphincter function compared with posterior fissures. […] There are other novel reasons published in the literature for a specific set of cases.

• #1

  https://ifnmujournal.com/gmj/article/view/272

  The problem of treatment of chronic complicated anal fissures remains one of the most important in modern proctology. […] To improve the treatment of chronic anal fissures, the effect of microbe biofilm on the basis of pathogenic component was studied, as the ability to form the film is an additional factor of pathogenicity of various microorganisms. […] A comprehensive treatment of CAF should include not only antibacterial therapy against infection found in the mucous defect of the rectum, but also new methods of ethiopathogenetic influence on the biofilm of a certain density formed by the microorganisms found in CAF. […] Bacteria associated in biofilms are more resistant to antimicrobial medicines and antiseptics in comparison with their planktonic forms. It allows to suggest that the ability of microorganisms collected from the mucous membrane of the anal fissures complicates antimicrobial therapy of the disease and defines its chronic development.

• #1 SciELO Brazil – A new theory on the cause of anal fissure – impaction theory A new theory on the cause of anal fissure – impaction theory

  https://www.scielo.br/j/jcol/a/DnJtp7W4MJZWS8hjBdgYjWD/

  The above blocks hinder defecation, which will inevitably lead to excessive opening of the anal caliber. Once the limit is exceeded, the skin of the anal canal will tear and form anal fissure. […] Therefore, we believe that anal fissure is a secondary disease, which can not only be cured by operation, but also by primary disease. Therefore, we put forward a new concept of the etiology of anal fissureimpaction theory. […] The so-called impaction theory refers to the impaction factors (various primary lesions) in anorectum that hinder defecation, cause excessive anal dilatation when defecating, exceed the anal dilatation limit, and open the whole layer of anal skin. […] The typical symptoms are periodic pain, repeated anal dilatation or tear, and fusiform ulcer caused by wound infection, namely anal fissure.

• #1 SciELO Brazil – A new theory on the cause of anal fissure – impaction theory A new theory on the cause of anal fissure – impaction theory

  https://www.scielo.br/j/jcol/a/DnJtp7W4MJZWS8hjBdgYjWD/

  The internal hemorrhoid, rectal tumor, hypertrophic anal papilla, and the fecal mass of the secret knot are regarded as the block of rectal impaction. […] All of the above blocks hinder defecation, which will inevitably lead to excessive opening of anal caliber. Once they exceed the limit, the skin of anal canal will tear and form anal fissure. […] The most fundamental pathological factor is the impaction factor in the primary anorectum.

• #1 Concepts in pathogenesis and treatment of chronic anal fissure–a review of the literature | Health & Environmental Research Online (HERO) | US EPA

  https://hero.epa.gov/hero/index.cfm/reference/details/reference_id/2239273

  Chronic anal fissures are associated with a persistent hypertonia and spasm of the internal anal sphincter. […] All treatments address the anomaly of a high anal pressure. […] Topical glyceryl trinitrate ointment and injection of botulinum toxin into the anal sphincter are advocated as the first-line treatment for chronic anal fissure.

• #1

  https://link.springer.com/article/10.1007/s10151-011-0683-7

  Anal fissure is one of the most common and painful proctologic diseases. […] In the last decades, the understanding of its pathophysiology has led to a progressive reduction of invasive and potentially invalidating treatments in favor of conservative treatment based on anal sphincter muscle relaxation. […] For many years an association with internal anal sphincter (IAS) hypertonia has been evident, although in elderly patients and in postpartum patients cases of anal fissure have been reported that are associated with a normal or hypotonic IAS. […] The basal tone of the IAS is affected by various substances, including nitric oxide (NO). In patients with anal fissures, the synthesis of NO in the IAS is reduced in comparison with the controls. […] This pathogenetic mechanism can explain the achievement of a high rate of healing with medical therapies able to improve blood flow and/or to reduce hypertonia.

• #1 Anal Fissure: New Concepts in Pathogenesis and Treatment

  https://www.periodicos.capes.gov.br/index.php/acervo/buscador.html?task=detalhes&id=W2097476132

  The posterior commissure of the anal canal is less well perfused than the other segments of the anoderm. There is growing evidence that the increased activity of the internal anal sphincter, which is found in almost all patients with a chronic anal fissure, further decreases the anodermal blood supply, especially at the posterior midline. […] Reduction of anal pressure, either by anal dilatation or by lateral internal sphincterotomy, is the most important step in the treatment of chronic anal fissure. However, both procedures frequently result in permanent sphincter defects and subsequent continence disturbances. […] Recently, nitric oxide (NO) has been identified as the chemical messenger mediating relaxation of the internal anal sphincter. It has been shown that local application of exogenous NO donors such as nitroglycerin and isosorbide-di-nitrate reduces anal pressure and improves anodermal blood flow. This dual effect results in fissure healing in more than 80% of patients.

• #1 How to treat anal fissures – THDLAB – COM | THD

  https://www.thdlab.com/patients/treatments/how-to-treat-anal-fissures/anal-fissures-treatment-options

  Anal fissures: remedies and prevention. […] The goal of conservative medical therapy is to promote the healing of the fissure and to reduce the contraction of the surrounding muscles. Excessive contraction of the sphincter causes hypertonia, which worsens the symptoms. […] Hypertonia is the natural defence reaction of the sphincter muscle which contracts due to the exposure of the lesion. This contraction reduces the blood supply in the area and slows healing. […] Nitroglycerin ointments aim to reduce the excessive contraction of the internal sphincter. […] Botulinum toxin injections in the anal sphincter aim to reduce hypertonia. […] Calcium channel blocker ointments act on hypertonia, reducing the maximum sphincter pressure at rest. […] If medical therapies do not give results or if the problem reappears or becomes acute again, surgery may be indicated.

• #1 +Bioline International Official Site (site up-dated regularly)

  https://www.bioline.org.br/request?hs07004

  Anal fissure is a common disease. The internal sphincter spasm is the main factor in the pathogenesis of chronic anal fissure. Therefore the treatment of this condition is aimed to reduce the internal sphincter hypertonia. Lateral internal sphicterotomy is the most frequently performed surgical procedure for treatment of chronic anal fissure which results in healing rate of 90 to 95%. It works by reducing the sphincter hypertonia which is the main etiological factor in the development of chronic anal fissure. […] BTX blocks sympathetic nerve function and myogenic tone of the internal anal sphincter (chemical sphinctrotomy), eliminating the sphincter hypertonia resulting in increase in the local tissue perfusion and healing of the chronic anal fissure. Muscle paralysis occurs within hours and the effect remains for 3-4 months. This prolonged effect allows the fissure to heal. This effect is reversible because it is followed by axonal regeneration and formation of new nerve endings which avoids the risk of permanent injury to the sphincter.

• #1 Anal fissure – Wikipedia

  https://en.wikipedia.org/wiki/Anal_fissure

  Lateral internal sphincterotomy (LIS) is the surgical procedure of choice for anal fissures due to its simplicity and its high success rate (~95%). In this procedure the internal anal sphincter is partially divided in order to reduce spasming and thus improve the blood supply to the perianal area. […] This improvement in the blood supply helps to heal the fissure, and the weakening of the sphincter is also believed to reduce the potential for recurrence.

• #1 How to treat anal fissures – THDLAB – COM | THD

  https://www.thdlab.com/patients/treatments/how-to-treat-anal-fissures/anal-fissures-treatment-options

  Lateral internal sphincterotomy involves the incision of the lateral portion of the anal sphincter. The incision of the sphincter helps to reduce hypertonia and promotes healing. […] In controlled lateral internal sphincterotomy the surgeon can in fact adjust the extent of the incision based on the sphincter length and the hypertonia severity, measured by anorectal manometry.

• #1 Closed anal sphincter manipulation technique for chronic anal fissure | Revista de Gastroenterología de México

  https://www.elsevier.es/es-revista-revista-gastroenterologia-mexico-288-articulo-closed-anal-sphincter-manipulation-technique-13131668

  The procedure proposed by us could be termed as a combination of sphincterotomy and anal stretch, in the sense that the internal sphincter fibers are severed by way of fragmentation leading to a localized division of internal sphincter fibers like that achieved after sphincterotomy using fingers in place of surgical dissection or division. This in turn helps in minimizing the inherent complications accompanying both the procedures i.e., avoidance of surgical wound and its sequel like bleeding, suppuration or fistula formation and averting inadvertent injury to the sphincter fibers caused due to anal stretch. […] The near-total division of internal sphincter allows early healing, while the resultant intramuscular linear fibrosis prevents long-term incontinence.

• #1 HIE Multimedia – Anal fissure

  https://adamcertificationdemo.adam.com/content.aspx?productid=117&pid=1&gid=001130

  Anal fissures are tears in the skin overlying the anal sphincter, usually due to increased tone of the anal sphincter muscles, and a failure of these muscle to relax. Anal fissures cause pain during defecation and bleeding from the anus. […] The goal is to relax the anal sphincter, which allows the fissure to heal. If these methods are ineffective, surgery is necessary. This is called an internal sphincterotomy, a procedure in which the anal sphincter is partially cut, thus allowing it to relax and permitting the fissure to heal. […] Sphincterotomy, when properly performed, is very effective in healing anal fissures.

• #1 .Anal fissure treatment by expert surgeons in Turkey

  https://bi-maristan.com/en/general-surgery/colorectal/chronic-anal-fissure-treatment/

  Most anal fissures result from the passage of a large amount of hard stool from the anal canal and anus. Therefore, all factors that increase the hardness of stool are accused of causing anal fissures, such as: […] Although most painful anal fissures caused by hard stool heal quickly, some people develop greater muscle pressure around the anus (anal sphincter pressure), which reduces blood flow and prevents the skin from healing well. […] Once an anal fissure develops, it will cause extremely severe pain during defecation, which increases the pressure on the anal sphincter more and more and slows down the healing of the anal fissure. […] Chronic anal fissures can lead to scar tissue hyperplasia at the site of the anal fissure.

• #1 Anal fissure: Clinical manifestations, diagnosis, prevention – UpToDate

  https://www.uptodate.com/contents/anal-fissure-clinical-manifestations-diagnosis-prevention

  Anal fissures typically start with a tear to the anoderm within the distal half of the anal canal. The tear then triggers cycles of recurring anal pain and bleeding, which lead to the development of a chronic anal fissure in as many as 40 percent of patients. […] The exposed internal sphincter muscle within the bed of the fissure frequently spasms, which not only contributes to severe pain but also can restrict blood flow to the fissure, preventing its healing.

• #1

  https://link.springer.com/article/10.1007/s11938-003-0007-8

  Diagnosis of chronic anal fissure is easy and common in clinical practice. Little is known about the etiology and pathogenesis of this disorder. Current investigations consider anal sphincteric hypertonia and ischemia as primary factors in the appearance and maintenance of this lesion. […] Recurrence rate after healing is high, so anal fissure may be a chronic disease that evolves depending on sphincteric features.

• #1

  https://fascrs.org/patients/diseases-and-conditions/a-z/anal-fissure

  Fissures are usually caused by trauma to the inner lining of the anus from a bowel movement or other stretching of the anal canal. […] Patients with a tight anal sphincter muscle are more likely to develop anal fissures. […] Less common causes of fissures include inflammatory bowel disease, anal infections, trauma or tumors. […] The goal of surgery is to help the anal sphincter muscles relax which reduces pain and spasms, allowing the fissure to heal. […] Surgical options include Botulinum toxin (Botox) injection into the anal sphincter or surgical division of an inner part of the anal sphincter (lateral internal sphincterotomy). […] Continued hard or loose bowel movements, scarring, or spasm of the internal anal muscle can delay healing. […] Anal fissures do not increase the risk of colon cancer nor cause it.

• #1 CONSERVATIVE TREATMENT FOR ANAL FISSURE – FOR HOW LONG? – REVIEW OF THE LITERATURE AND PERSONAL EXPERIENCE | Șurlin | Facta Universitatis, Series: Medicine and Biology

  https://casopisi.junis.ni.ac.rs/index.php/FUMedBiol/article/view/5234/0

  Anal fissure (AF) is a common proctologic disease and health problem, with potential for chronicity, causing the patient a debilitating suffering. The pathogenesis, in most of the cases consists in a vicious circle of pain-internal anal sphincter (IAS) spasm-decrease blood irrigation of mucosa-delay of healing. […] Treatment should aim to break this mechanism by cutting or relaxing the IAS and restoring adequate blood flow to promote healing.

• #2 Anal Fissure: Practice Essentials, Anatomy, Pathophysiology and Etiology

  https://emedicine.medscape.com/article/196297-overview

  The exact etiology of anal fissures is unknown, but the initiating factor is thought to be trauma from the passage of a particularly hard or painful bowel movement. […] Low-fiber diets (eg, those lacking in raw fruits and vegetables) are associated with the development of anal fissures. […] Initial minor tears in the anal mucosa due to a hard bowel movement probably occur often. In most people, these heal rapidly without long-term sequelae. In patients with underlying abnormalities of the internal sphincter, however, these injuries progress to acute and chronic anal fissures. […] The most commonly observed abnormalities are hypertonicity and hypertrophy of the internal anal sphincter, leading to elevated anal canal and sphincter resting pressures. […] The posterior anal commissure is the most poorly perfused part of the anal canal. In patients with hypertrophied internal anal sphincters, this delicate blood supply is further compromised, thus rendering the posterior midline of the anal canal relatively ischemic.

• #2 Anal Fissures – Anorectal Diseases – Intestinal Diseases – Gastrointestinal Diseases – Gastroenterology – Diseases – McMaster Textbook of Internal Medicine

  https://empendium.com/mcmtextbook/chapter/B31.II.4.23.4.

  An anal fissure is defined as a longitudinal tear in the epithelial lining of the distal anal canal. […] The exact cause of anal fissures is unknown. An initiating traumatic event, such as passage of a hard stool or trauma, causes a tear in the epithelial lining. High resting anal canal pressure (hypertonic sphincter) and reduced blood flow prevent healing and result in mucosal ischemia and fissure formation. […] Some risk factors that may contribute are diets lacking in fiber, previous anal surgery, childbirth, and laxative abuse.

• #2 CONSERVATIVE TREATMENT FOR ANAL FISSURE – FOR HOW LONG? – REVIEW OF THE LITERATURE AND PERSONAL EXPERIENCE | Șurlin | Facta Universitatis, Series: Medicine and Biology

  https://casopisi.junis.ni.ac.rs/index.php/FUMedBiol/article/view/5234/0

  Anal fissure (AF) is a common proctologic disease and health problem, with potential for chronicity, causing the patient a debilitating suffering. The pathogenesis, in most of the cases consists in a vicious circle of pain-internal anal sphincter (IAS) spasm-decrease blood irrigation of mucosa-delay of healing. […] Treatment should aim to break this mechanism by cutting or relaxing the IAS and restoring adequate blood flow to promote healing.

• #2 Anal fissure: Clinical manifestations, diagnosis, prevention – UpToDate

  https://www.uptodate.com/contents/anal-fissure-clinical-manifestations-diagnosis-prevention

  Anal fissures typically start with a tear to the anoderm within the distal half of the anal canal. The tear then triggers cycles of recurring anal pain and bleeding, which lead to the development of a chronic anal fissure in as many as 40 percent of patients. […] The exposed internal sphincter muscle within the bed of the fissure frequently spasms, which not only contributes to severe pain but also can restrict blood flow to the fissure, preventing its healing.

• #2 Concepts in pathogenesis and treatment of chronic anal fissure–a review of the literature | Health & Environmental Research Online (HERO) | US EPA

  https://hero.epa.gov/hero/index.cfm/reference/details/reference_id/2239273

  Chronic anal fissures are associated with a persistent hypertonia and spasm of the internal anal sphincter. […] All treatments address the anomaly of a high anal pressure. […] Topical glyceryl trinitrate ointment and injection of botulinum toxin into the anal sphincter are advocated as the first-line treatment for chronic anal fissure.

• #2

  https://link.springer.com/article/10.1007/s10151-011-0683-7

  Anal fissure is one of the most common and painful proctologic diseases. […] In the last decades, the understanding of its pathophysiology has led to a progressive reduction of invasive and potentially invalidating treatments in favor of conservative treatment based on anal sphincter muscle relaxation. […] For many years an association with internal anal sphincter (IAS) hypertonia has been evident, although in elderly patients and in postpartum patients cases of anal fissure have been reported that are associated with a normal or hypotonic IAS. […] The basal tone of the IAS is affected by various substances, including nitric oxide (NO). In patients with anal fissures, the synthesis of NO in the IAS is reduced in comparison with the controls. […] This pathogenetic mechanism can explain the achievement of a high rate of healing with medical therapies able to improve blood flow and/or to reduce hypertonia.

• #2 Anal fissure pathophysiology – wikidoc

  https://www.wikidoc.org/index.php/Anal_fissure_pathophysiology

  The exact pathogenesis of anal fissure is not fully understood but constipation or anal trauma was supposed to instigate the fissure. […] It is understood that anal fissure is the result of either anal trauma (by hard stools/diarrhea), perfusion defects with ischemia caused due to increased anal pressures and decreased blood flow or increased anal sphincter tone. […] This is believed due to ischemia/poor perfusion of the area by inferior rectal artery (during increased sphincter tone). […] Some studies in 1970-80 have suggested the increased tone of internal sphincter as the basis of anal fissure genesis. […] The increased internal sphincter tone also leads to decreased perfusion. […] Use of anal manometry have suggested hypertonia of internal sphincter as a cause of anal fissure, and also relaxation in chronic anal fissures.

• #2 Surgery for Anal Fissure: Background, Indications, Contraindications

  https://emedicine.medscape.com/article/1582334-overview

  Schouten et al proposed that anal fissures were ischemic ulcers and found that patients with anal fissures had significantly higher resting anal sphincter tone and decreased anodermal blood flow in comparison with healthy volunteers. Other studies confirmed that blood supply to the posterior midline of the anoderm is relatively poor when compared with blood supply to the other quadrants. […] This combination of increased tone and poor blood supply likely contributes to the relative ischemia of the posterior midline of the anoderm; however, not all patients with anal fissures have anal sphincter hypertrophy or insufficient blood supply to the anoderm.

• #2 Anal Fissure

  https://lacolon.com/patient-education/anal-fissure

  Anal fissures are a common problem, bringing many patients to the colorectal surgeons office with complaints of anal pain. […] Anorectal trauma secondary to the passage of diarrhea or a hard stool is the most common cause of an anal fissure. […] Increased resting internal anal sphincter pressure with resultant ischemia has been postulated to be the main factor in fissure persistence. Healing is slowed as the vascular supply to the local area is compromised by intense sphincter spasm. […] Angiographic studies have demonstrated that the posterior anal midline has the lowest tissue perfusion, consistent with the finding that this location is the most common fissure location. […] It is thought that nitroglycerin acts as a topical anal sphincter smooth muscle relaxant, enabling an increased blood flow to the injured anal area. The mechanism of action may be similar to its action on the coronary arteries during an episode of angina. […] Diltiazem is a calcium channel blocker and may serve to relax the anal sphincter in the same fashion as during its use in the treatment of hypertension or angina.

• #2 Anal fissure – Australian Prescriber

  https://australianprescriber.tg.org.au/articles/anal-fissure.html

  It is hypothesised that this predilection for the posterior midline may occur because this portion of the anal canal is poorly perfused. Anterior anal fissures affect approximately 10% of patients and may have a different pathophysiology. They are associated with younger, mostly female, patients often with injury to or dysfunction of the external anal sphincter. […] A small study of completely excised anal fissures found no underlying microscopic features of inflammation in most of the patients. Further, these fissures or defects showed little in the way of ulcer characteristics and appeared to be more consistent with unstable anodermal scar tissue. Additional research is needed to understand the temporal relationship between poor perfusion and lack of inflammation, as well as to identify the best terminology to describe these lesions.

• #2 Anal Fissure – an extensive update

  https://ppch.pl/seo/article/147879/en

  Madalinski and Kalinowski theorised that in chronic fissures, the stretchability of the anal sphincters is insufficient leading to eruption of tissue in the fissure region during defecation and these erupted tissues release vessel contraction mediators which have a tendency to arrest the healing process by interference with endothelial nitric oxide expression. […] The pathophysiology of anterior fissures may however be different than that of posterior fissures. […] The study showed that the anterior anal fissures are associated with occult external anal sphincter injury, lower maximum squeeze pressure and impaired external anal sphincter function compared with posterior fissures. […] There are other novel reasons published in the literature for a specific set of cases.

• #2 Thieme E-Journals – Clinics in Colon and Rectal Surgery / Abstract

  https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-0031-1272820

  Anal fissure is largely associated with high anal sphincter pressures and most treatment options are based on reducing anal pressures. […] The vascular pathogenesis of anal fissures. […] Ischaemic nature of anal fissure. […] Anterior anal fissures are associated with occult sphincter injury and abnormal sphincter function. […] Neuromyogenic properties of the internal anal sphincter: therapeutic rationale for anal fissures. […] A contraction response of the internal anal sphincter to Botulinum toxin: does low-pressure chronic anal fissure have a different pathophysiology?

• #2 SciELO Brazil – A new theory on the cause of anal fissure – impaction theory A new theory on the cause of anal fissure – impaction theory

  https://www.scielo.br/j/jcol/a/DnJtp7W4MJZWS8hjBdgYjWD/

  The internal hemorrhoid, rectal tumor, hypertrophic anal papilla, and the fecal mass of the secret knot are regarded as the block of rectal impaction. […] All of the above blocks hinder defecation, which will inevitably lead to excessive opening of anal caliber. Once they exceed the limit, the skin of anal canal will tear and form anal fissure. […] The most fundamental pathological factor is the impaction factor in the primary anorectum.

• #2 Botox for Anal Fissure: Pathogenesis, Signs & Symptoms | Medica Depot

  https://www.medicadepot.com/blog/botox-for-anal-fissure-pathogenesis-signs-symptoms.html

  Anal fissure refers to the condition where a split or tear occurs in the distal anal canal that extends from the anal verge towards the dente line. […] However, spasm of the internal anal sphincter is known to play a key role in the pathogenesis of the condition. […] This mechanism of action enables the toxin to relax smooth muscle in the gastrointestinal tract, thus disrupting negative feedback loop associated with the development of chronic anal fissure. Due to this, Botox does not just treat the symptoms the toxin stops the pathogenic mechanisms involved in chronic fissure, preventing further progression and enables healing to start.

• #2 How to treat anal fissures – THDLAB – COM | THD

  https://www.thdlab.com/patients/treatments/how-to-treat-anal-fissures/anal-fissures-treatment-options

  Lateral internal sphincterotomy involves the incision of the lateral portion of the anal sphincter. The incision of the sphincter helps to reduce hypertonia and promotes healing. […] In controlled lateral internal sphincterotomy the surgeon can in fact adjust the extent of the incision based on the sphincter length and the hypertonia severity, measured by anorectal manometry.

• #2 About Anal Fissures | Memorial Sloan Kettering Cancer Center

  https://www.mskcc.org/cancer-care/patient-education/about-anal-fissures

  An anal fissure is a small tear or rip in the lining of your anal canal. […] The most common cause of anal fissures is injuring the lining of your anus. This can happen when you: […] The pain may also cause the muscles around your anal canal to spasm. […] This spasm prevents your anal fissure from healing and leads to more pain. This is called the fissure cycle. […] You can prevent anal fissures by avoiding constipation and diarrhea. […] People with colon cancer may develop anal fissures, but anal fissures dont cause colon cancer or increase your risk of getting colon cancer.

• #2 +Bioline International Official Site (site up-dated regularly)

  https://www.bioline.org.br/request?hs07004

  The resting pressure in the anal canal is largely a function of the internal sphincter. The continuous partial contraction of the sphincter is due to an inherent myogenic tone and alpha adrenergic nerve mediated pathways. Patients with chronic anal fissure usually have a raised resting anal pressure due to hypertonicity of the internal sphincter. This compromises perfusion of the anal mucosa as the blood vessels supplying the distal anal canal traversing the internal sphincter en route to the anal mucosa may be compressed by the hypertonic muscle leading to chronic anal fissure. This is why chronic anal fissure has been described as an ischemic ulcer.

• #2 Evaluation of anal canal morphology with MRI in cases with anal fissure

  https://epos.myesr.org/poster/esr/ecr2015/C-1670

  Anal fissure is a vertical tear between dentate line and anocutaneous junction. It is located at the posterior midline in the %90 of the cases. One of the reasons of its presence at this location is that the superficial external anal sphincter gets far away from the anus and moves towards the coccyx at the posterior. This part which is called Minor triangle is unsupported and may be damaged during faeces passage. […] The increase of the traction angle (K angle) of the anal canal by the superficial external sphincter to the coccyx may expand the unsupported part (Minor triangle) of anal canal and may have a role in the pathogenesis of anal fissure. It has been thought that length of the anal canal may have a role in the pathogenesis of anal fissure. In the chronic cases, long-standing inflammatory reactions lead to…

• #3 Anal fissure

  https://pmc.ncbi.nlm.nih.gov/articles/PMC4816871/

  The pathophysiology of anal fissures is not entirely clear. It is probable that an acute injury leads to local pain and spasm of the internal anal sphincter. This spasm and the resulting high resting anal sphincter pressure leads to reduced blood flow and ischaemia, and poor healing. Unless this cycle is broken the fissure will persist. […] It is hypothesised that this predilection for the posterior midline may occur because this portion of the anal canal is poorly perfused. Anterior anal fissures affect approximately 10% of patients and may have a different pathophysiology. They are associated with younger, mostly female, patients often with injury to or dysfunction of the external anal sphincter. […] A small study of completely excised anal fissures found no underlying microscopic features of inflammation in most of the patients. Further, these fissures or defects showed little in the way of ulcer characteristics and appeared to be more consistent with unstable anodermal scar tissue. Additional research is needed to understand the temporal relationship between poor perfusion and lack of inflammation, as well as to identify the best terminology to describe these lesions.

• #3 Anal Fissure – an extensive update

  https://ppch.pl/seo/article/147879/en

  The precise aetiology is still unclear in AF unless the fissure is secondary to some disorder. The initiating factor is thought to be trauma to the anoderm from the passage of particularly hard or large stools, local irritation from diarrhoea, anorectal surgery, and anoreceptive intercourse. […] However, in patients with underlying abnormalities of the internal sphincter, these otherwise minor injuries progress to AF. Studies of the anal physiology have been performed with varied results, but the most commonly observed abnormalities are hypertonicity and hypertrophy of the internal anal sphincter (IAS), leading to elevated anal canal and sphincter resting pressures compared to the pressures in the normal controls. […] The increased internal sphincter tone induces local ischemia that prevents the fissure from healing, creating a chronic wound.

Zobacz więcej