An anal fistula is a chronic, pathological canal between the perianal skin and the rectal canal, often formed after a perianal abscess breaks down or is incised and drained, and is mainly associated with anal gland infection. It is called “anal leakage” in Chinese medicine.
Diagnosis
I. Clinical manifestations
1. Symptoms: recurrent episodes of perianal swelling and pain, pus flow, and fever during the acute inflammation period.
2. Local examination: visual examination shows the shape, location and secretion of the external opening. A superficial anal fistula can be palpated around the anus with a hard striated node and its rows. The internal opening, depressions and nodules can be palpated by rectal palpation; the anal sphincter function can be assessed in general.
3. Ancillary examinations.
(1) Probe examination: preliminary exploration of the fistula tract.
(2) Anorectoscopy: used in conjunction with hydrogen peroxide or methylene blue (concentration), the location of the internal opening can be initially determined.
(3) Fistulography: contrast agents such as pancystic glucosamine can be used, which is particularly informative for the diagnosis of complex anal fistulas.
(4) Endorectal ultrasound: to observe the course of the fistula, the internal orifice, and to determine the relationship between the fistula and the sphincter.
(5) CT or magnetic resonance imaging: used for the diagnosis of complex anal fistula, which can better show the relationship between the fistula and the sphincter.
4. Classification of anal fistula.
(1)Domestic classification.
A. Low anal fistula
Low simple anal fistula: the internal opening is in the anal saphenous fossa, and only one fistula passes through the subcutaneous or superficial part of the external sphincter and communicates with the skin.
Low complex fistula: there are more than two internal or external ports, and the fistula tract is subcutaneous and superficial to the external sphincter.
B. High anal fistula
High simple fistula: the internal opening is in the anal saphenous fossa, and there is only one fistula tract that travels above the deeper layer of the external sphincter.
High complex anal fistula: there are more than two external orifices, connected to the internal orifice through the fistula or with a branched cavity, and its main tube passes above the deep layer of the external sphincter.
(2) Parks classification.
The classification of anal fistulas depends on the relationship between the fistula and the anal sphincter and is divided into: intersphincter type, trans-sphincter type, over-sphincter type, and extra-sphincter type. Fistulas are considered complex when they cross more than 30-50% of the external sphincter (high intersphincter, supra-sphincter, extra-sphincter), anterolateral fistulas in women, multiple fistulas, recurrent fistulas, or fistulas with anal incontinence, which may cause anal incontinence after treatment.
Differential diagnosis
Anal fistulas need to be differentiated from tuberculous anal fistulas, inflammatory bowel disease anal fistulas, purulent sweat glands, perianal subcutaneous cyst infections, perineal urethral fistulas, sacrococcygeal cysts or teratomas combined with infected abscesses, infection of the hidrocystic sinus, rectal endometriosis, and Bartholin’s gland cyst infections. In addition, uncommon infections such as tuberculosis or actinomycetes can also present as specific anal fistulas, and a detailed clinical history and relevant investigations can help to make the correct diagnosis.
Identification
1. Dampness and toxicity within the anus
Pus flowing around the anus, thick pus, anal swelling and pain, local redness, burning, thirst, dyspareunia, short and red urine, heavy body, red tongue with yellowish coating and stringiness of pulse.
2. Positive deficiency of evil
Intermittent flow of pus around the anus, thin pus, dull skin color at the external opening, fistula festering and healing, vague pain in the anus, may be accompanied by fatigue, light tongue with thin coating, moist pulse.
3. Fire and poison accumulation
Sudden swelling and pain around the anus, which continues to increase, accompanied by chills and fever, constipation and short red urine. Redness and swelling around the anus, with obvious tenderness, hard texture and burning surface. The tongue is red, with thin yellow coating and a number of pulse.
Treatment
I. Treatment principles
Surgery is the main treatment for anal fistula. The basic principles are: removal of the lesion, unobstructed drainage, minimizing damage to the anal sphincter and protecting the function of the anus. Due to the complexity of anal fistula and some special pathological background, anal fistula has a certain recurrence rate after surgery. In view of the special pathological and physiological background of high-grade complex anal fistula and the importance of anal function, “survival with fistula” can also be chosen as a principle, and surgical eradication should not be blindly pursued to the neglect of the serious complications it may bring. Chinese medicine treatment is limited to patients who are recovering and not suitable for surgery for the time being.
II. Non-surgical treatment
(A) Chinese medicine treatment
1. Typology and treatment
(1) Dampness and toxicity
Treatment: Clearing heat and detoxification, removing dampness and eliminating swelling.
Example formula: Dioscorea Z and Dampness Soup combined with Five Flavors Disinfection Drink plus reduction.
Commonly used drugs: 30g each of Dioscorea Z and Coix Seed, 12g each of Phellodendron Bark, 15g each of Poria, Dan Pi and Ze Di, 30g each of Slippery Rock, 6g of Tong Cao, 9g of Honeysuckle, 4g each of Wild Chrysanthemum, Zingiber officinale and Dandelion.
(2) Deficiency of the right and evil
Treatment: Tonifying Qi and Blood, supporting the lining and generating muscle.
Example formula: Ten whole tonic soup.
Commonly used herbs: Ginseng, Atractylodes Macrocephala, Poria, Radix et Rhizoma Glycyrrhizae, Radix Angelicae Sinensis, Rhizoma Chuanxiong, Radix Rehmanniae Sinensis, Radix Paeoniae Alba, Radix Astragali, Cinnamon 10g each.
(3) Fire poisoning
Treatment: Removal of fire and toxins, elimination of blood stasis and dispersion of nodules.
Example formula: Wu Wei Disinfectant Drink combined with Xian Fang Livestrong Drink plus or minus.
Commonly used herbs: 10g each of honeysuckle, wild chrysanthemum, dandelion, aster dahurica, 10g each of dahurica, 10g each of frankincense and myrrh, 10g each of soapberry, 10g each of gweiwei.
2. External Chinese medicine
Clearing heat and detoxifying, reducing swelling and relieving pain. For example: bitter ginseng soup, toxin removal soup, etc.
(II) Mucous plugging method
Fibrin glue plugging method is feasible for the treatment of simple non-inflammatory anal fistula, which has the advantages of no sphincter damage, does not affect anal function, and is easy to operate, but the recurrence rate is high.
Surgical treatment
(a) Surgical methods
1. anal fistula incision (removal): applicable to simple anal fistula. Anal fistula incision is better, and anal fistula excision has large trauma and relatively long healing time, and anal incontinence can occur.
2. hanging wire: reasonable choice of cutting wire and drainage wire. First-stage cutting and hanging: it is suitable for high anal fistula involving most of the external anal sphincter above the superficial part. Second-stage cutting and hanging wire: it is suitable for some high anal fistulas combined with difficult residual cavity, or requiring secondary surgery and postoperative drainage. Long-term drainage hook-ups: for patients with high trans-sphincteric Crohn’s disease fistulas to prevent recurrent abscess formation and to maintain anal function. Short-term drainage line: Although short-term drainage line has been reported to be effective in the treatment of anal fistula, which completely preserves the sphincter and does not lead to anal incontinence, it should be applied with caution because of its high recurrence rate.
3. Mucosal flap nudging: It is suitable for patients with high anal fistula with clear internal orifice and no serious infection and for women with anterolateral anal fistula.
The organic combination of incision, absolution, hanging and suturing can also be used to reduce trauma.
(II) Postoperative complications
In particular, complications such as anal displacement, mucosal ectasia, anal canal defect and anal incontinence may occur after surgery for high complex anal fistula. The trauma should be minimized during surgery, and anal sphincter repair or flap surgery is feasible if necessary.
(C) Management of special patients
1. Crohn’s disease anal fistula
The treatment should be as conservative as possible along with systemic treatment. Asymptomatic Crohn’s fistula: no need for surgery; low Crohn’s fistula: use fistulotomy; complex Crohn’s fistula: can be long-term hanging line for palliative treatment. If the real intestinal mucosa is largely normal to the naked eye, a mucosal flap can be used to close the inner mouth.
2. Tuberculous fistula
It is necessary to combine systemic anti-tuberculosis treatment (isoniazid, rifampin, ethambutol, streptomycin, etc.) with the local use of traditional Chinese medicine (including herbal creams and sitz baths), the components of which are: Phellodendron, Comfrey, Amaranthus, bitter ginseng, dahurica, angelica, ku alum,: superficial fistula is the main, there is a possibility of self-healing, non-surgical ineffective can choose to incision.