Intramuscular hematoma of the rectus sheath

　　Firstly, etiology

　　The etiology of the disease is not yet clear, and the following factors may be the causes or triggers of hematoma within the rectus sheath.

　　1. Anatomical factors: The artery within the rectus sheath is curved, the lower part of the rectus muscle is surrounded by a strong muscle cell membrane, and there is a longer distance before the artery branches into the muscle. The Hessel's triangle area below the posterior sheath of the rectus muscle is a weak point, with poor protective and supportive effects on the abdominal wall blood vessels. When the muscle contracts strongly, the blood vessels in this area are prone to be torn, becoming a local anatomical factor of the disease.

　　2. Direct or indirect local trauma.

　　3. Muscle degeneration or myositis.

　　4. Local vascular degeneration due to arteriosclerosis.

　　5. Low tension of the abdominal rectus muscle in obese individuals.

　　6. The influence of estrogen in pregnant women, as well as the excessive contraction of abdominal muscles during childbirth.

　　7. The influence of long-term use of antimetabolites, antihypertensive drugs, and anticoagulants.

　　Secondly, pathogenesis

　　When blood vessels in the rectus muscle area rupture due to some factors, the blood cannot develop along the longitudinal axis due to the adhesion of the rectus muscle tendinous band and the anterior sheath, forming a hematoma locally.

　　Accompanied by lower abdominal peritoneal irritation signs.

　　Generally, it can be caused by abdominal infection, perforation, obstruction, bleeding from visceral injury, and other reasons. The peritoneum has abundant nerves and blood vessels, and patients usually manifest severe, intolerable abdominal pain, excessive sweating, high fever, general weakness and fatigue, and unresponsiveness. Peritoneal irritation signs can be caused by a variety of diseases. The onset is acute, and the vast majority can be cured, while a very few can die due to untimely treatment.

　　After coughing, vomiting, or strong contraction of the abdominal muscles, lower abdominal pain may occur with nausea and vomiting, followed by the appearance of an abdominal mass. The mass is usually confined to one side of the rectus muscle, does not cross the midline, and the infiltration of blood into the muscle makes it hard, forming a sausagelike mass. A palpable, immovable, tender mass can be felt, and it can still be palpated when the abdominal muscles contract. If the hematoma extends downward beyond the Douglas peritoneal ring, the accumulated blood can spread along the extraperitoneal tissue and cause peritoneal irritation signs in the lower abdomen.

　　The etiology of this disease is unclear, and its possible factors include local tissue anatomy, direct or indirect local trauma, muscle degeneration or myositis, local vascular degeneration due to arteriosclerosis, low abdominal rectus muscle tension in obese individuals, the influence of estrogen in pregnant women, as well as the excessive contraction of abdominal muscles during childbirth, the long-term use of antimetabolites, antihypertensive drugs, and anticoagulants. Therefore, the main focus of prevention is to address its causes:

　　1. Maintain smooth defecation to avoid exerting force to increase abdominal pressure during defecation.

　　2. For diseases such as hypertension and hyperlipidemia that cause vascular fragility, active treatment should be given to avoid bleeding caused by vascular rupture.

　　3. When giving birth, wait until the cervix is fully dilated before exerting force to avoid increasing negative pressure and causing this disease.

　　4. Regular detection of coagulation function is needed for patients taking anticoagulant drugs for a long time.

　　I. Imaging examination:

　　1. Abdominal X-ray:The lateral view can show the image of the widened rectus sheath.

　　2. Ultrasound or CT scan:It can be found that the mass is located inside the rectus sheath of the abdominal wall, with low density, clear boundaries, and not communicating with the peritoneum.

　　II. Abdominal wall puncture:

　　If abdominal organ injury cannot be ruled out, abdominal wall puncture can be performed, and the local aspiration of blood-like fluid is the most important diagnostic method for this disease.

　　III. Blood examination:

　　The total white blood cell count is normal or slightly high, and the neutrophils generally do not change.

　　1. Pay attention to a light diet and regular eating habits.

　　2. Diet should be reasonable according to the doctor's advice.

　　3. There are no great taboos for this disease in diet, and a reasonable diet is sufficient.

　　I. Treatment

　　Within 24 hours of onset, if abdominal organ injury can be ruled out, conservative therapy can be performed, and local cold compress and pressure bandage can be used at the same time as the treatment of the primary disease. If the diagnosis of this disease is accurate and the treatment is timely, unnecessary laparotomy can be avoided. If it cannot be ruled out, abdominal puncture or lavage can be performed to help differentiate, but if the hematoma continues to expand, surgical treatment should still be considered. The purpose of surgery is to incise the hematoma, remove blood clots, and ligate the bleeding vessels; if there is oozing bleeding, a drain can be placed, and it can be removed after 24 to 48 hours. Pay attention to the protection of the abdominal wall after surgery and the treatment of the primary disease. If it is confirmed that it is not a hematoma of the abdominal wall, further exploration can be performed inside the abdomen.

　　II. Prognosis

　　The prognosis of this disease is good, and attention should be paid to the protection of the abdominal wall after surgery.