Both pilonidal sinus and pilonidal cyst are collectively called pilonidal sinus disease, which is a chronic sinus or cyst in the soft tissue of sacrococcygeal fissure, characterized by hair embedding. It can also be manifested as an acute abscess in sacrococcygeal region, which forms a chronic sinus after perforation, or temporarily heals and finally penetrates, so it can recur. Cysts are accompanied by granulation tissue and fibrous hyperplasia, and often contain a tuft of hair. Although the disease can occur after birth, it mostly occurs at the age of 20 ~ 30 after puberty, and symptoms appear only because of the increased activity of hair fat glands. The main diagnostic signs of pilonidal sinus and pilonidal cyst are acute abscess in sacrococcygeal region or secretion in chronic sinus, and local acute inflammation. The pilonidal cavity can be seen in the midline during examination, and the pilonidal sinus can be easily diagnosed by symptoms and signs. Treatment measures-Non-surgical treatment of sacrococcygeal fossa does not need treatment, because there is only a depression in sacrococcygeal joint, lower sacrum and tip of coccyx, which has no symptoms and no clinical significance. If the sacrococcygeal pilonidal sinus and sacrococcygeal swelling infection, anti-inflammatory treatment should be carried out to keep the local clean. If the abscess reappears, incision and drainage should be performed. However, the sacrococcygeal skin and subcutaneous tissue are thick and hard, and there is no obvious manifestation in the early stage. Inflammation often spreads to surrounding tissues, leading to cellulitis. Deep tissue necrosis should be treated by early incision and drainage. Sclerotherapy is to inject corrosive drugs into the sinus, destroy the epithelium in the sinus and capsule, and seal the cavity and sinus. Since 1960, some people have used phenol solution injection therapy, but few people have used it, because the pure phenol solution is used and the pain is severe. Later, it was switched to 80% concentration and performed under general anesthesia. Inject glue into the sinuses to protect the surrounding skin. Hegge( 1987) was slowly injected into the sinuses with 80% phenol solution 1~5ml, about 1 ~ 5ml. Slow injection can prevent complications such as skin burn, fat necrosis or severe pain. This method can be repeated every 4 ~ 6 weeks 1 time, about half of the patients can be cured by injecting 1 time, and 12% needs to be injected more than 5 times. 43 cases were followed up for more than 1 year, and only 3 cases (6%) recurred. Stansby (1989) injected 80% phenol solution into the sinus under general anesthesia, kept 1min, and scraped the sinus three times. 104 cases, 4 cases developed aseptic abscess, 1 case developed cellulitis, and there were no other complications. Compared with 65 cases of surgical resection, the treatment rate; Excision was 86% and phenol injection was 75%. The average follow-up period was 8 months (from 3 months to 4 years), and 10 cases were resected and 12 cases were injected. Surgery is the main treatment, but it is taboo when there is inflammation, and surgery should be performed after the inflammation subsides. There are several surgical methods: 1. One-stage suture surgery removes all diseased tissues, free muscles and skin, and completely sutures the wound to make it heal in the first stage. In order to eliminate the deep luteal fissure and its negative pressure, and reduce the wound dehiscence, hematoma and abscess, Z plasty is feasible (figure 1). It is suitable for cysts and small sinuses with uninfected midline, and the recurrence rate is 0% ~ 37%. Its advantages are short healing time, soft scar activity in gluteal groove, and soft tissue between scar and sacrum, which can tolerate injury. Figure 1 Make an oval incision at the pilonidal sinus. Left: Make an oval incision at the pilonidal sinus. Middle image: the full-thickness flap is separated and displaced; Right: skin suture. 2. Remove the diseased tissue by partial suture. The skin on both sides of the wound was sutured to the sacral fascia, which made most of the wounds heal in the first stage and the granulation tissue in the middle part healed. It is suitable for cases with many ostia and sinuses, and the effect is the same as that of primary suture, but the healing time is longer. 3. Open secondary suture is suitable for cases of severe infection and cases of primary suture incision drainage infection. 4. Incision is suitable for cases where the wound is too large to be sutured and the operation recurs. The operation is simple, but the healing period is long, the scar is extensive, and only a thin layer of epithelium adheres to the sacrum. If there is an injury, the scar will break easily. 5. Bag suture was used to remove the surface part and upper skin of sinus wall, and the wound was healed with catgut or absorbable artificial suture. Careful postoperative care can often bring satisfactory results. This is the most common case where the pilonidal sinus cannot be resected or recurred. Results of various treatment methods Keighley( 1993) analyzed the recurrence rate of seven treatment methods in the literature: ① only open treatment was 7% ~ 24%; ② 0% ~ 22% for resection and open surgery; ③ Excision plus suturing accounted for 7% ~13%; ④ resection and primary suture were 65438 0% ~ 46%; ⑤ 0% ~ 10% is resection and z-shaped plastic surgery; ⑥ Resection of rhombic skin flap accounts for 3% ~ 5%; ⑦ 0% ~ 5% is used for excision and layered skin transplantation. The real cause of the disease is unknown. There are two theories. A congenital skin inclusion caused by residual medullary canal or sacrococcygeal suture deformity. However, the precursor lesions of hidden diseases are rare in the shallow concave area behind the anus at the midline of infants, but more common in adults. It is considered that sinus cyst is a granulomatous disease caused by trauma, operation, foreign body stimulation and chronic infection. Recently, it has been confirmed that the main reason is that the hair enters from the outer fold. Luteal fissure has negative attraction, which can make the shed hair penetrate into the skin. There are too many hairs in the cracks, and the hair tips can filter and soften the skin. Hair penetrates into the skin, forming a short path, and then goes deep into a sinus. When the hair root falls off and enters the sinus, the hair shaft can also penetrate, and the movement changes can be seen at the onset (Figure 2), but only half of the cases can find hair. This disease is more common in patients with hirsutism, excessive sebum activity, deep hip fissure and frequent hip injury. The sacrococcygeal skin of drivers is often damaged by long-term bumps, which can make sebaceous glands and debris accumulate in the capsule and cause inflammation. This disease occurs more frequently in the US Army. It is called Jeep Disease. Common pathogens are anaerobic bacteria, staphylococcus, streptococcus and Escherichia coli. Rainsbury and Southan analyzed the problem of static storage, and found that less than half were single bacteria, and 58% were anaerobic bacteria. Strangely, staphylococcus is not common, and most aerobic bacteria are gram-negative bacteria. Fig. 2 Formation and natural evolution of pilonidal sinus On the right: there are pits in the groove, and the hair gradually penetrates; Right: The hair permeates a lot. Because of the secondary inflammation, the skin sinus finally forms clinical manifestations. If there is no secondary infection, pilonidal cysts are often asymptomatic, but the sacrococcygeal part is prominent, and some feel pain and swelling in the sacrococcygeal part. Usually, the main and first symptom is acute abscess in sacrococcygeal region, which is characterized by acute inflammation such as redness, swelling, heat and pain. Most of them automatically break through the outflow of pus or the inflammation subsides after surgical drainage, and a few drainage openings can be completely closed, but most of them show recurrent attacks or frequent running water to form sinuses or fistulas. Irregular pores with a diameter of about 1 mm ~ 1 cm can be seen in the skin of sacrococcygeal midline during the static period of pilonidal sinus. The surrounding skin is red, swollen and hard, often scarred, and some can still see hair. The probe can probe into 3 ~ 4 mm, some can probe into 10cm, and there is a thin and smelly liquid discharged during extrusion. In acute attack, there is acute inflammation, tenderness and redness, more purulent secretions, and sometimes abscesses and cellulitis. Differential diagnosis should be differentiated from furuncle, anal fistula and granuloma. Furuncle grows on the skin, protrudes from the skin and turns yellow at the top. Carbuncle has multiple external pores and necrotic tissue inside. The external orifice of anal fistula is close to * * *, and the fistula runs to * * *. The diagnosis is that there is a cord, the anal canal has an internal orifice, and there is a history of rectal abscess. However, the trend of the pilonidal sinus is mostly toward the cranial side and rarely downward (Figure 3). Tuberculous granuloma is connected with bone. X-ray examination showed bone destruction and tuberculous lesions in other parts of the body. Syphilitic granuloma has a history of syphilis and syphilis serum is positive. Fig. 3 the course of pilonidal sinus note: 93% of the sinuses go out of the skin fossa to the cranial side; 7% can walk around under * * *. Prognostic cancer rarely occurs in the pilonidal sinus, and Phipshen( 198 1) only examined 32 cases. Most of the lesions were well-differentiated squamous cell carcinoma. The change of wound should cause suspected canceration, such as the ulcer is easy to break, grows fast, leaves the sedan chair and has mold-like edges. Extensive resection should be the first choice Because wounds are widely treated with skin grafts or skin flaps. Abdominal and femoral lymph node lesions should be biopsied to rule out metastasis. If there is metastasis, the prognosis is not good. Literature reports that the 5-year survival rate is 565,438+0%. The recurrence rate was 50%. Metastasis of abdominal cavity and femoral lymph nodes was found at the first diagnosis, accounting for 14%.