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Anal fistula
What causes anal fistulas?
The most common cause of anal fistula is perianal abscess. Both anal fistula and perianal abscess involve infections at the anal crypts. Typically, an anal fistula forms naturally after a perianal abscess ruptures. Once an anal fistula occurs, it requires prompt surgical treatment. The primary surgical technique is fistulotomy with seton placement, thoroughly removing the local lesion and infection focus to allow fresh granulation tissue to regrow. Anal fistula is a local infectious disease of the anus, generally categorized into simple superficial anal fistula and high-risk complex anal fistula. If a high-position complex anal fistula is suspected, further diagnosis may require additional examination with pelvic MRI or perianal ultrasonography. After the rupture of a perianal abscess, it typically forms a characteristic internal and external opening, with a fistula tract connecting them, thereby forming the typical anal fistula.
causes of anal fistula
Anal fistula is one of the common diseases in proctology. The formation of an anal fistula is caused by infection of the anal sinuses and anal glands. Due to damage to the anal sinuses and anal glands, bacteria from the intestines enter these areas. As immunity weakens, the bacteria cause localized inflammation, which then leads to the formation of an abscess. After the abscess bursts, an anal fistula forms. This is the pathogenesis of anal fistula.
Best treatment method for anal fistula abscess
The best treatment method for anal fistula and perianal abscess is surgical treatment, which is also the only curative method. Conservative treatment using drugs alone can only alleviate local inflammatory symptoms and cannot achieve complete cure. The main surgical method is the cutting and threading technique. This involves threading and ligating the infected area and the sphincter muscle. Through the slow cutting and drainage action of the ligature, the infection focus is removed while protecting the anal sphincter. Postoperatively, it is also important to pay attention to disinfecting and draining the local wound, ensuring proper dressing changes, and preventing poor drainage that could lead to infection or recurrence. It is advised that patients avoid spicy and irritating foods for the first six months after surgery.
How to deal with the internal opening of an anal fistula?
The internal opening of an anal fistula is generally located at the site of inflammation in the anal crypt. The primary reason for the formation of an anal fistula is the repeated outbreaks at the anal crypt, which lead to further infection and the formation of a perianal abscess. When the abscess cavity ruptures, it forms an external opening and the anal fistula. Surgical treatment is required for the internal opening of an anal fistula, generally involving a seton procedure that threads a line through the internal opening and part of the sphincter muscle, gradually cutting and draining the area slowly. If the inflammation at the internal opening is significant, it may also be necessary to excise part of the infected site in the anal crypt. Post-surgery care of the internal opening of an anal fistula primarily involves dressing changes, requiring daily thorough disinfection of the local area, ensuring clear drainage, to allow the granulation tissue at the internal opening to grow freshly, and to slowly heal the wound without infection. (Medication should be taken under the guidance of a doctor.)
What will happen if an anal fistula is not treated?
An anal fistula is a chronic fistula and duct caused by an infection of the anal sinuses. If not treated, an anal fistula may repeatedly flare up. The consequences of repeated occurrences can lead to abscesses, peripheral spreading, and eventually extensive spreading of the loose tissue around the anus, which in severe cases may damage the anal muscles, leading to anal incontinence. If an anal fistula persists for a long time, there is also a possibility of malignant transformation.
Which is more serious, anal fistula or hemorrhoids?
Anal fistulas and hemorrhoids are two different types of common colorectal diseases; neither can be said to be more severe than the other, as the severity of each disease depends on its progression and extent. If it's a simple superficial anal fistula, the severity is generally mild, primarily treated with surgery. However, if a high, complex anal fistula is present, in addition to surgery, a comprehensive pelvic MRI examination is also required to rule out any infections in the deep sphincter and ischioanal fossa. The severity of hemorrhoids primarily involves circular mixed hemorrhoids, or those accompanied by incarceration. If circular mixed hemorrhoids with incarceration occur, it is advisable to undergo surgical treatment as soon as possible to avoid necrosis. If hemorrhoids result in persistent and significant rectal bleeding, surgery should also be performed promptly to prevent anemia in the patient.
Is the probability of anal fistula turning into cancer high?
An anal fistula, formed due to an anal gland infection, carries a higher risk of malignant transformation if the infection and inflammation are recurrent and persistent, particularly over a long period exceeding five years. Therefore, it is strongly recommended that anal fistulas exceeding five years should be given sufficient attention and surgical treatment should be pursued promptly to prevent malignancy.
Anal fistula etiology
The cause of an anal fistula is due to infection of the anal glands. In normal human anatomy, there is a location at the junction of the rectum and the anal canal called the anal sinus or anal gland, which is relatively weak. If it is damaged, intestinal bacteria can enter the anal gland, causing inflammation. Over time, the infected anal gland leads to further abscesses towards the perianal space, causing a perianal abscess. After the perianal abscess ruptures, it further develops into an anal fistula.
How long will it take for a fallen anal fistula seton to heal?
The primary surgical method for anal fistulas is the fistulotomy with seton placement. The duration for which the seton, made of elastic band, remains in place largely depends on the severity of the anal fistula and the amount of sphincter muscle tied. If the fistula is a simple superficial one, the seton usually falls out around seven days. In cases of high, complex anal fistulas, or those with multiple branching fistula tracts and multiple sphincters tied, the seton may take slightly longer to fall out, generally about ten days. If the seton has not fallen out after the local sphincter muscle has fully regenerated, it can be cut by a professional proctologist. However, it is important to note that postoperative care mainly involves dressing changes until the seton falls out, indicating that the wound has largely healed.
Can people with anal fistula drink alcohol?
Patients with anal fistula are advised not to drink alcohol. As an anal fistula already features distinct external and internal openings as well as a fistulous tract, excessive or chronic alcohol consumption can stimulate recurrent local inflammatory episodes. This can cause an increase in the secretions from both openings, leading to varying degrees of anal pain and itching for the patient, worsening the condition, potentially increasing the branches of the fistula, or causing it to spread deeper or to other areas. Therefore, not only should patients with anal fistula abstain from alcohol, but they should also maintain a light diet rich in green vegetables and fruits. Once diagnosed, it is crucial for patients with anal fistula to undergo surgical treatment promptly. The primary surgical approach involves fistulotomy with seton placement. Postoperatively, attention must be paid to the dressing of the local wound to avoid pseudo-healing and infection.