White line hernia

　　The white line is located between the xiphoid process and the pubic symphysis, forming a tendinous strip interwoven between the left and right rectus abdominis muscles by the tendinous fibers of the three layers of flat muscles (external oblique, internal oblique, and transversus abdominis) on the anterior and lateral abdominal wall. It is wider at the top and narrower at the bottom, with a width of 1.25 to 2.5 cm above the navel, narrow and thick below the navel, with a width of only about 0.1 cm most of the time. Abdominal white line hernia occurs most often above the navel, rarely below the navel, which may be related to this important factor.

　　The inner and outer surfaces of the linea alba have different structural characteristics. On the outer surface, the crossed peritoneal fibers are uniform in thickness and tightly interwoven, with only small holes for the passage of small blood vessels and nerve branches. On the inner surface, the tendinous fascicle fibers are uneven in thickness, often forming thick bundles or plates, and their direction is not very regular. There are holes, pits, or fissures in the interlacing fibers through which nerve and blood vessel branches pass, creating defects in the inner layer of the linea alba, which are the weak parts of the linea alba. If the intra-abdominal pressure increases, the extraperitoneal fat and peritoneum are pushed into the larger defects by the abdominal pressure, forming a linea alba hernia. All the peritoneal fibers of the anterior and lateral abdominal wall muscles cross obliquely at the linea alba to form small 'diamond-shaped gaps', which can expand into the hernia ring. The area 4 cm below the navel and the edge of the half-circle line is a weak point on the linea alba, and linea alba hernias below the navel often occur here. It can be seen that linea alba hernias are related to two major factors: reduced abdominal wall strength and increased intra-abdominal pressure.

　　1. Weakened wall strength

　　It belongs to anatomical structural reasons and is the basis for the occurrence of hernias, which can be classified into congenital and acquired conditions. Congenital conditions include incomplete closure of the peritoneal processus, a high inferior border of the internal oblique muscle, a wide inguinal triangle (Hesselbach), incomplete closure of the umbilical ring, defects in the abdominal linea alba, and some normal anatomical phenomena, such as the spermatic or uterine round ligaments passing through the inguinal canal, and the femoral arteries and veins passing through the femoral canal area, which can also weaken the strength of the abdominal wall at this location. Acquired causes include poor healing of surgical incisions and drain sites, trauma, inflammation, infection, surgical interruption of abdominal wall nerves, excessive fat infiltration in overweight individuals, muscle atrophy and degeneration in the elderly, and abnormal collagen metabolism, which causes the firm fascial tissue to be replaced by a loose connective tissue layer or fat with microscopic pores.

　　2. Increased intra-abdominal pressure

　　It is a predisposing factor with many causes, such as chronic cough (such as in smokers and elderly bronchitis patients), chronic constipation, ascites, late pregnancy, difficulty in urination (prostatic hypertrophy, phimosis), frequent crying in infants, weightlifting, frequent vomiting, and abdominal tumors, among others.

　　Patients with linea alba hernia generally have a good prognosis, with no special complications. The omentum is prone to adhere to the hernia sac, forming a refractory hernia that is difficult to recur, and rarely becomes incarcerated. Although linea alba hernia rarely incurs incarceration or strangulation, 10% of patients may still experience refractory phenomena, causing discomfort and even the risk of strangulation. Therefore, patients with larger linea alba hernias, or those with refractory, incarcerated, or strangulated hernias, should undergo surgical treatment if the diameter is greater than 0.5 cm and they have symptoms.

　　The linea alba is formed by the merging of the anterior and posterior sheaths of the lateral rectus muscles on both sides, where the sheath fibers interlace to form a reticular pattern. The larger openings in this pattern become the weak points on the linea alba, which are prone to causing hernias. The clinical symptoms mainly include the following.

　　1. Abdominal pain

　　The most common symptom of patients with epigastric hernia is upper abdominal pain. Most patients only present with localized, mild pain in the upper abdomen, while a few patients present with severe deep pain. The mechanism of abdominal pain is mainly due to the compression of the intercostal nerve fibers passing through the epigastric line by the hernia mass, causing localized pain. The omentum and round ligament are pulled, causing deep pain. Abdominal pain can radiate to the lower chest and back. The degree of pain is related to posture, eating, and heavy physical labor. Changes in posture, especially when lying flat, often alleviate or disappear the pain, while eating or heavy physical labor can worsen it. The severity of abdominal pain is not proportional to the size of the hernia, often with small hernias and severe clinical symptoms.

　　2. Nausea and vomiting

　　In addition to abdominal pain, some patients with white line hernia may also experience symptoms such as nausea and vomiting. The pathogenesis is:

　　① The traction of the prolapsed omentum and round ligament of the liver can cause deep pain and reflexive symptoms such as nausea and vomiting.

　　② The traction of the omentum and round ligament of the liver can lead to pyloric spasm, resulting in symptoms such as nausea and vomiting.

　　3. Abdominal wall mass

　　An abdominal wall mass is the main sign of epigastric hernia. Since the vast majority of epigastric hernias occur between the umbilicus and the xiphoid process, the hernia mass is usually located on the epigastric line between the xiphoid process and the umbilicus, and can be off the midline. The mass is more obvious when standing or after meals. The diameter of the hernia mass is generally about 2-4 cm, and some scholars have reported that the largest hernia mass has a diameter of up to 15 cm. A few patients have a small hernia mass, which is just a soft rounded protuberance under the skin and is not easy to detect. Obese patients are even more difficult to find. After the hernia contents are reduced, the edge of the fascial hernia ring hole at the epigastric line can be felt.

　　4. Positive Litten sign

　　During physical examination, place the fingers on the patient's suspected hernia site and ask them to cough while standing. Often, a cracking sound can be felt with the cough, indicating a positive Litten sign.

　　5. Inducing pain

　　By holding the mass with the thumb and index finger and pulling it outward, abdominal pain is often induced due to the traction of the round ligament of the liver, peritoneum, or omentum, which Moure et al. believe is a specific clinical sign of epigastric hernia.

　　Long-term physical labor, trauma, pregnancy, obesity, and a large amount of ascites can all be predisposing factors for white line hernia. When the diaphragm and the upper abdomen undergo unsynchronized, strong simultaneous contraction, such as during a severe cough or when holding one's breath, the force generated by the upward pull of the diaphragm and the lateral pull of the tendinous intersections is greatest at the midpoint between the xiphoid process and the umbilicus, so this is the most common site for the occurrence of white line hernia. Therefore, the main measure to prevent white line hernia is to prevent the causes that may lead to white line hernia.

　　The contents of the epigastric hernia mass are mostly fatty tissue, omentum, and small intestine, which are respectively presented as moderate echo, slightly high echo, and disordered echo in ultrasound, and the intestinal shape can be seen. Therefore, ultrasound is of great help in determining the nature of the hernia contents. In addition, ultrasound examination has the characteristics of low cost, convenience, and good reproducibility, and can be used as the first choice for diagnosing epigastric hernia. Ultrasound examination can be divided into general ultrasound examination and high-frequency ultrasound examination.

　　1. When performing an ultrasound examination for an incision hernia, due to the content of the mass being fat and omentum, it often suggests clear boundaries, lobulated shape, and uniformly hyperechoic masses, which are ultrasound signs of lipomas. This can cause some interference in the correct diagnosis and is usually considered to be a lipoma, or considered to be a subcutaneous fibroma of the abdominal wall, sebaceous adenoma, etc., which is prone to misdiagnosis.

　　2. The method of high-frequency ultrasound local direct exploration is simple, easy to perform, and painless. Since it can clearly display the stratified structure of the abdominal wall, the contents of the hernia, and the condition inside the abdominal cavity, as well as the hernia ring, hernia sac, hernia contents, and their relationship with surrounding tissues, combined with Valsalva maneuver and color Doppler blood flow information, it can clearly diagnose whether the hernia is incarcerated and the degree of incarceration, which can provide reliable evidence for the clinical formulation of treatment plans. Therefore, this examination can be used as a routine imaging examination for incision hernia diagnosis.

　　For patients with unclear ultrasound diagnosis of incision hernia of the abdominal linea alba, three-dimensional CT examination can be performed, which can not only accurately measure the size of the hernia defect but also visually display the hernia image and detect hidden hernias.

　　Patients with incision hernia can have fluid food such as rice gruel, thin lotus root powder, vegetable juice, and fruit juice within 6 to 12 hours after surgery. On the second day, soft food or regular food can be consumed, such as soft rice, noodles, egg cake, chopped and cooked vegetables and meat, etc., focusing on nutrition-rich, easy-to-digest, and light diet.

　　In terms of diet, it is advisable to eat more nutritious foods. Eat more roughage foods such as chives, celery, cabbage, coarse grains, beans, bamboo shoots, and various fruits. Keep the bowels smooth and use jellyfish, bitter melon, sweet potatoes, etc.

　　An incision hernia protruding through the abdominal linea alba is also known as an epigastric hernia. The abdominal linea alba is formed by the interweaving of the two sides of the rectus sheath of the abdomen along the midline of the abdomen. Generally, traditional Chinese medicine practitioners will adopt the following methods for treatment:

　　1. Take Xian Qi Ne Xiao Wan twice a day, 9 grams each time.

　　2. Take Ju She Wan twice a day, 9 grams each time.

　　3. Take Bu Zhong Yi Qi Wan three times a day, 9 grams each time.