I. Overview of perianal abscess
Perianal and perirectal abscess, often referred to as perianal abscess in clinical practice, refers to the abscess formed by the infection of anal glands and the spread of pus to the anal canal and rectum, which is equivalent to the abscess formed by acute and chronic infection in the perirectal space in Western medicine. It is characterized by rapid onset, severe pain and high fever in most young adults aged 20 to 40. It is a clinical emergency and should be treated as early as possible to avoid aggravation of the condition.
The etiology and pathogenesis of perianal abscess
Chinese medicine believes that this disease is mostly due to excessive consumption of fatty, sweet, spicy, alcoholic wine and other things, dampness and turbidity do not dissolve, heat is contained and injected into the large intestine, poison blocks the meridians, stagnation of blood and stasis, and the flesh rots into pus and becomes carbuncle and gangrene due to heat victory.
Western medicine believes that this disease is mainly due to anal gland infection. Most of the clinical occurrence of anal canal and rectal abscess is closely related to the infection and suppuration of anal gland.
Diagnosis and classification of perianal abscess
(I) Clinical manifestations
The disease is more common in men than women, especially in young adults. First, they feel a lump around the anus with slight pain, or they feel stinging or swelling pain in the anus, and then the pain increases, the lump around the anus increases, redness, swelling, tenderness, hardness, accompanied by different degrees of fever, lethargy, loss of appetite, constipation and other symptoms. Abscesses can be formed locally in about a week, and there can be local fluctuation after abscess formation. If the abscess breaks down by itself or after incision, yellowish-white pus may flow out, after which the pain may gradually be relieved or disappear and the body temperature may drop. Other symptoms may also be relieved.
The symptoms vary depending on the location and depth of the abscess. For example, the interstitial abscess above the anal raphe is deep and hidden, with heavy systemic symptoms but light local symptoms, while the interstitial abscess below the anal raphe is shallow, with obvious local redness, swelling and heat pain but light systemic symptoms.
1.Para-anal subcutaneous abscess occurs in the subcutaneous tissue around the anus and is the most common. The abscess is usually small, and the systemic symptoms are not obvious, but the local pain is heavy, mostly persistent or throbbing pain. There is obvious redness, hardness and tenderness in the perianal area. If the abscess has become purulent, there is a fluctuating sensation. Difficulty in urination may occur if the abscess is located on the anterior side. Examination reveals a slightly red raised mass on the anal side with inconspicuous boundaries and obvious tenderness.
2.Sciatorectal interstitial abscess Occurring between the anus and the sciatic tuberosity, located in the sciatorectal interstitial space, the abscess is extensive and deep. Initially, it only feels discomfort or slight pain and soreness in the anus. Systemic symptoms of toxicity are obvious, with high fever, chills, headache, weakness, difficulty in urination and loss of appetite. Subsequently, the local symptoms worsen. Skin swelling, redness and dull pain appear on the anal side of the affected area, and throbbing pain after abscess formation. The pain increases during defecation, coughing, walking, and even sitting and lying down. There are localized hard nodules and obvious pressure pain on palpation. There is pressure pain and fluctuating sensation in the anal canal or rectal wall corresponding to the anorectal hiatus of the patient by anal finger diagnosis.
3.Pelvic rectal interstitial abscess Located above the anal raphe and below the peritoneum. Mostly formed due to abscesses in the sciorectal space, which are not drained by surgery in time and the pus penetrates upward into the anal raphe. It is also formed directly by the spread of inflammation of the anal sinus and anal gland. Because the abscess is deep and hidden, the symptoms of systemic infection are very serious, while the local symptoms in the anus are not obvious. Due to the deep abscess site, it takes longer time to break down by itself. On finger palpation, a bulging mass can be palpated on the rectal wall, with pressure pain and fluctuating sensation.
4.Posterior rectal space abscess Discomfort in defecation is an early symptom. At the initial stage, there is malignant chill and fever, and there is obvious feeling of swelling in the rectum, and the pain in the perineum is dull and can be radiated to the lower limbs. As the lesion continues to develop, the systemic symptoms may worsen, and there is obvious deep pressure pain between the tailbone and the anus. The finger palpation in the anus can be done after the anal canal, below the level of the anal canal rectal ring, and a limited hard nodule or mass can be palpated with fluctuation.
5. Rectal submucosal abscess is located in the submucosal space between the rectal mucosa and the internal sphincter. Initial symptoms often include a feeling of heaviness or fullness in the rectum, and pain is obvious when defecating or walking. Generally, the systemic symptoms are obvious, while there are no obvious local symptoms in the anus, and superficial masses can be palpated under the mucosa with pressure pain and fluctuating sensation during the internal finger examination.
6.Tuberculous perianal abscess often starts slowly, the swelling and pain are light, and the pus is clear and thin or with cheese-like material after the pus is broken or incised, often accompanied by low fever, night sweats, zygomatic redness, physical wasting and other symptoms.
(B) Other auxiliary examinations
1.Laboratory examination According to the total number of white blood cells and the classification count, the degree of infection can be judged.
2.Ultrasonic examination is helpful to understand the size and location of abscess and the connection with anal canal and rectum.
3.Pathological examination The nature of the lesion can be determined by taking the tissue of the abscess cavity wall for examination.
4.Abscess puncture For abscess with deeper site, it is difficult to judge whether it has become pus or not, the diagnosis can be confirmed by puncturing and aspirating at the center of abscess or the most obvious place of pressure pain with thick lumbar puncture needle under local anesthesia.
5.CT examination For patients with repeated attacks, CT examination should be conducted to clarify the specific location and size of the lesion.
IV. Treatment of perianal abscess
The treatment principle of perianal abscess is mainly to control the spread of infection and reduce the pain of patients. A few perianal abscesses can be dissipated with antibiotics, hot water sitz baths and local physiotherapy, but most of them need surgical treatment. That is to say, when the abscess is not formed, that is, when cryptitis is present, conservative therapy can still be considered, applying effective antibiotics intravenous drip or enema, using Chinese herbal medicine for evidence-based treatment, the use of local suppositories and Chinese herbal sitz baths, etc., which can achieve more satisfactory results.
Once an abscess is formed, the most aggressive method is timely incision and drainage. It has even been asserted that surgery for perianal abscess is inevitable and there is no need to wait for a sense of local fluctuation to occur to avoid the spread of inflammation. The incision for incision and drainage varies, but the aim is to allow adequate fluent drainage of pus. Since most of the primary lesions are anal glands in the anal fossa in the dentate line area of the anal canal, the search and excision of the internal opening is extremely important.
There are two types of surgery: one is a simple abscess incision and drainage, and the second is a one-time surgery, in which the abscess is incised and drained while the internal orifice is treated to avoid the formation of an anal fistula. There are advantages and disadvantages to both procedures, but the chance of forming an anal fistula after simple incision and drainage is very high, and reoperation is still required. The decision of which procedure to use depends on whether the internal orifice is found after incision, the location of the abscess, the patient’s general condition and the operator’s level of experience, and should not be made arbitrarily in advance.
We emphasize here that in acute inflammation, when there is difficulty in finding the internal opening, one should not blindly look for it to avoid spreading inflammation or forming a false tract, and only make an incision to drain the abscess and wait for the formation of an anal fistula.
(I) Internal treatment method
In the early stage, most of the evidence is actual and hot, the treatment is to clear the heat and detoxify, cool the blood and dispel blood stasis, soften the hardness and disperse the knots. In the middle stage, when the pus becomes evil and remains, the treatment should be to support the righteousness and detoxification, and the main treatment should be the method of tor. In the later stage, when the toxin is exhausted and the body is deficient, the treatment should be to nourish the qi and blood, strengthen the spleen and permeate dampness, nourish the liver and kidney, and the main treatment is tonic.
(II) External treatment method
1, dressing Initially, the actual evidence is applied externally with Dazheng paste (Shandong Province Hospital of Traditional Chinese Medicine in-hospital preparation), Jinhuang paste, Huanglian paste, and for deep location, Jinhuang San can be mixed into a paste for enema, and the deficiency evidence is applied externally with Chonghe paste or Yang and Xingying paste. After pus is formed, early incision and drainage is appropriate. After festering, use red oil paste gauze to drain or medicine line to drain, and change to use raw muscle san gauze when pus is exhausted.
2, fumigation is mostly used after the abscess is ulcerated, it has the function of clearing heat and detoxification, relieving swelling and pain, astringent and stopping bleeding, dispelling dampness and itching, and dispelling rot and creating muscle. Commonly used in bitter ginseng soup, dispel poison soup, detoxification lotion (Shandong Provincial Hospital in-hospital preparation) and 1:5000 potassium permanganate solution, etc.
(C) Surgical treatment
1.One-time incision method for abscesses Applicable to shallow abscesses.
2.One-time incision and hanging method Applicable to high abscesses, abscesses in the sciatic rectal fossa, abscesses in the pelvic rectal space, abscesses in the posterior rectal space and horseshoe abscesses.
3.Split operation Applicable to patients with deep abscesses who are weak or unwilling to be hospitalized.
For patients with large swelling, obvious systemic symptoms, or weakness, or one-time surgery, effective antibiotics can be used to control and prevent infection.
V. Characteristics and treatment of various interstitial perianal abscesses
(I) Non-fistulous perianal abscess
Non-fistulous perianal abscess mainly includes five types of perianal intradermal abscess, perianal subcutaneous abscess, rectal submucosal abscess, pelvic rectal gap abscess and posterior rectal gap abscess. The main points of treatment are to choose a reasonable incision, to carry out adequate drainage inside and outside the anus, and to apply antibiotics appropriately according to the characteristics of the infection.
1.Para-anal intradermal abscess Para-anal intradermal abscess is non-anal glandular and basically the same as abscesses of other parts of the skin, mainly caused by infection of hair follicles or sebaceous glands of the skin. It can be cured by external application of tincture of iodine before suppuration. In larger cases, hot compresses or hot water baths are given to encourage suppuration. If pus is formed, the pus head can be removed or cauterized with a toothpick dipped in a little carbolic acid. There are more treatment methods and the treatment is relatively simple.
2.Para-anal subcutaneous abscess Non-fistulizing perianal subcutaneous abscesses are mostly developed from intradermal abscesses, but they are larger and more painful than perianal intradermal abscesses. The best treatment is incision and drainage, and the general treatment is the same as for paranal subcutaneous abscesses. A paranal subcutaneous abscess that forms an anal fistula is called a fistulous paranal subcutaneous abscess and is caused by an infection of the anal glands.
3, rectal submucosal abscesses Submucosal abscesses of the lower rectal segment are mostly due to improper injection of drugs or insertion of drugs into the nucleus of the hemorrhoid, which usually do not cause anal fistula. There are also clinical cases of pelvic abscess caused by the rupture of the intestinal wall due to the injection of drugs too deeply, and this treatment is relatively complicated and should be sufficiently alert. The treatment of rectal submucosal abscess is based on conservative therapy, and the application of high doses of effective antibiotics is effective. At present, ceftriaxone and metronidazole combined with intravenous drip, or quinolones intravenous drip, etc. are mainly used. It can also be directly incised or hung. If treatment is delayed, endogastric fistula is often formed clinically, but rarely involves other perianal interstices, and treatment is relatively simple.
4.Pelvic-rectal interstitial abscess The main cause of pelvic-rectal interstitial abscess is infection in the abdominal cavity and infection of pelvic organs, although there are many reference books that believe that it has the same cause as perianal-rectal abscess, but this is obviously not the main one. This means that the vast majority of pelvic-rectal interstitial abscesses are not caused by anal gland infections. There is often a delay in the diagnosis of pelvic-rectal gap abscesses in the early stages, because in the early stages patients only have a feeling of heavy fall of the rectum, or discomfort in the anal canal during defecation, and in the heavier cases there is a feeling of frequent or incomplete defecation and poor urination.
Once a pelvic-rectal interstitial abscess is diagnosed, it must be drained promptly. There are two ways of drainage: one is to drain into the rectal cavity through the rectal wall; the other is to drain through the skin to the outside of the body. Modern medicine believes that the latter is better, because internal drainage due to the role of the anal sphincter, there is often a certain amount of pressure, so that the drainage is not smooth, while the pus cavity often suffer from fecal contamination, may prolong the drainage time, so it is not desirable.
Using external anal drainage, the success rate of surgery is only about 50%, and the other half forms anal fistulas, which some people attribute to the fact that it is not easy to find the internal opening. The author’s practice shows that most of the causes of this type of abscess are as described above, but of course it is not easy to find the internal port, because most of them do not have one. The reason for the difficulty in healing is poor drainage, and it is difficult to solve a highly located abscess with a single drainage port through the anal sphincter. The multi-port drainage advocated by the author is able to solve this problem, such as counter-port drainage.
5.Posterior rectal space abscess The posterior rectal space is basically at the same level as the pelvic rectal space, only separated by the lateral rectal ligament, so the posterior rectal space abscess is similar to the pelvic rectal space abscess, which is generally not caused by anal gland infection. This type of abscess is less common clinically. There are two ways of treatment, i.e. intra-anal drainage or external drainage, the latter being preferable. Anal fistulas formed by improper treatment of this type of abscess have their own specificity, which makes clinical treatment difficult and often recurs. The author clinically found that this type of perianal abscess is the main cause of recurrence of high anal fistula or abscess treated by incision and hanging.
(II) Fistulous perianal abscess
Fistulous perianal abscesses mainly include four types of perianal subcutaneous abscesses, abscesses within the rectal wall, abscesses in the colorectal fossa and abscesses in the deep space behind the anal canal. The main points of treatment are to find the obvious internal opening and remove it thoroughly, and to drain the abscess cavity adequately.
Most of the paranal subcutaneous abscesses are caused by anal canal rupture such as anal fissure and anal cryptitis, and the infection spreads outward through the subcutaneous part of the external sphincter to form subcutaneous interstitial abscesses. This includes superficial anterior and posterior anal canal abscesses. It is most common clinically. The internal orifice is usually at the anal saphenous fossa and, to a lesser extent, at the intersphincteric sulcus. Treatment is best by incision and drainage. If an obvious internal orifice can be found during surgery, it should be incised together with the external orifice, otherwise an anal fistula may form. If the internal opening cannot be found, about half of them may form an anal fistula. Surgery for anal fistulae should be performed 3 weeks after the fistula has formed, which can reduce local damage to the anus. It is also possible to see patients with paranal subcutaneous abscesses that have not recurred for many years by simple incision.
2, rectal wall abscesses Rectal wall abscesses include submucosal abscesses in the lower rectum and abscesses located between the longitudinal rectal muscle and the circular muscle, mainly caused by anal saphenous or anal gland infection upstream. The abscesses often form endogastric fistulas after self-rupture. Treatment of submucosal abscesses of the lower rectum has been described previously. Abscesses located between the longitudinal and circumferential rectal muscles are usually cured by surgery with an incision or hanging thread from the internal port upwards.
3.Sciorectal fossa abscesses Sciorectal fossa abscesses are the most common clinically, with heavy symptomatic manifestations. One side of the sciorectal fossa has a volume of 40-90 ml, and both sides can be connected via the anterior and posterior anal gaps. It is characterized by the fact that the internal opening of these abscesses is mostly near the dentate line of the anal canal, and the abscesses in the deep posterior anal canal space have less obvious symptoms in the initial stage, and the volume of the posterior anal canal space is small. The possibility of this abscess penetrating upward through the anal raphe to form a pelvic rectal hiatus or posterior rectal hiatus abscess is extremely small, so there is no need to artificially probe for a higher location. Incision and drainage remains the best option. If the surgical experience is insufficient, the safest method is to still perform the surgery in stages, i.e., incision and drainage first, followed by anal fistula surgery.
4, deep posterior anal canal abscesses Deep posterior anal canal abscesses are mostly caused by infection of the anal glands located in the posterior anal saphenous fossa. Due to the characteristics of the deep posterior anal canal space, abscesses are formed and soon communicate with the sciatic rectal fossa on one or both sides, resulting in abscesses in the sciatic rectal fossa. It is often clinically confused with simple sciorectal fossa abscess. The greatest point of differentiation is that the former can form a high hoof-shaped anal fistula, whereas the latter only forms a low anal fistula. The treatment of deep posterior anal canal abscesses also has its own special features because the lower border is the caudal ligament, and care should be taken to protect this ligament during incision and drainage of the positive posterior anal canal. Drainage on both sides of the posterior anal canal space and drainage of the corresponding colorectal fossa are generally used with excellent clinical results.
(C) Special types of perianal abscess
Traumatic perianal abscess refers to purulent infection of the perianal space caused by trauma around the anus, which can form a sinus tract or an anal fistula connected with the rectum. The internal opening of this type of fistula is not limited to the anal saphenous and can be anywhere in the rectum of the anus. The treatment method is mostly based on the characteristics of the wound, using treatment such as debridement, incision and drainage, and hanging thread.
2.Foreign body perianal abscess Most of the perianal abscesses are caused by misuse of foreign bodies or piercing around the anus. Common foreign bodies include denture, fish bone, chicken bone taken by mistake, bamboo spikes, needles, glass fragments and other small metal objects pierced into the anus, etc. In addition, it has been reported that pinworms cause perianal abscesses, which are caused by death and ulceration of pinworms in the anal glands through the anal fossa, leading to infection by intestinal pathogenic bacteria. The treatment mainly adopts methods such as incision and drainage and removal of foreign bodies.
3, diabetic perianal abscess is one of the complications of diabetes, abscesses are often multiple, thin pus. It is difficult to be cured by incision and drainage alone, and diabetes should be treated actively, generally so that blood sugar control is around 8mmol/L, which can not affect the wound healing. However, after this type of patient is cured once, there is often recurrence, and clinical attention should be paid.
4.Leukemic perianal abscess Leukemia can easily lead to perianal abscess because of the disease characteristics and chemotherapy, which makes the systemic anti-infection ability decrease. This type of abscess can spread to the whole perianal area, and it is relatively difficult to control and treat. When conditions permit, chemotherapy should be temporarily discontinued and a large amount of antibiotics or Chinese herbal medicine should be applied to identify the evidence for internal use and external washing, which can achieve certain results.
5.Tuberculous perianal abscess Tuberculous perianal abscess can be divided into two kinds: secondary and primary. Most of them are secondary to open pulmonary tuberculosis or tuberculosis of adjacent organs, and are infected by bloodstream, lymphatic dissemination or pus infusion. Primary anal and rectal tuberculosis is extremely rare, and is usually caused by a decrease in systemic and local immune function after there is damage to the anal skin or rectal mucosa, coupled with the misuse or misuse of food or drinks containing large amounts of tuberculosis bacteria, resulting in the growth and multiplication of Mycobacterium tuberculosis in the anal and rectal areas and the formation of tuberculous perianal abscess. The clinical features of this abscess are: easy self-rupture, flat and depressed wounds, thin secretions, and nodule-like growths around the wounds, which often recur. The diagnosis is usually confirmed by X-ray chest film, pathological examination, pus smear, sputum culture and PCR tuberculosis DNA test. The principle of treatment is mainly rational anti-tuberculosis treatment. If surgery is needed, it should be performed after anti-tuberculosis treatment to stabilize the disease or intensive treatment for 2 to 4 weeks.
6.Founier syndrome and perineal necrotizing fasciitis Founier syndrome and perineal necrotizing fasciitis are closely related to anal diseases, and are mixed infections, often showing symptoms of perianal abscess; perianal abscess can not be controlled by incision and drainage, and spreads rapidly to the perianal area, perineum and scrotum. After the diagnosis is confirmed, the disease should be treated quickly, with extensive and thorough removal of necrotic lesions and high-dose application of effective antibiotics to control the infection. The disease is dangerous and can be life-threatening, so clinical attention should be paid to it.
7.Perianal abscess causes other diseases Comprehensive reports show that high perianal abscess can lead to scrotal abscess and right lower abdominal wall abscess; perianal abscess can be complicated by liver abscess, etc.
Prevention and care of perianorectal abscess
Perianorectal abscess brings great pain to patients, if you don’t want to be attacked by the disease or reduce the pain, then please pay attention to the following matters.
1.Actively prevent and treat other anorectal diseases, such as anal sinusitis, anal papillomegaly, anal fissure, inflammatory hemorrhoids, proctitis, etc. Once found, timely, correct and effective treatment can be provided to avoid and reduce the occurrence of perianal infection, abscess and anal fistula;
2, prevention and control of constipation and diarrhea is important for the prevention of perianal infection, which can avoid and reduce the damage or inflammation of the mucosa and epithelial tissue in the anorectal area, and can reduce the incidence of abscesses and anal fistula;
3, timely treatment of systemic diseases that can cause perianorectal abscesses, such as ulcerative colitis, intestinal tuberculosis, Crohn’s disease, etc.;
4, keep the anus clean and hygienic, change underwear regularly, adhere to the daily cleaning of the anus after the stool, to prevent infection has a positive role;
5, the usual active physical exercise, enhance physical fitness, can enhance and improve the anal blood circulation, so that the local resistance to disease, can prevent the occurrence of infection;
6, once the anorectal infection occurs, should be early to the regular hospital, and the use of effective anti-infection measures, including systemic and local treatment, can prevent the spread of inflammation, spread, do not believe in the so-called “ancestral” propaganda of wandering doctors and delay the diagnosis and treatment.