Indirect inguinal hernia in children

　　The failure of the peritoneal processus vaginalis (Nuck tube) to close and regress is the pathological basis of inguinal hernia in children. In the 5th week of embryogenesis, the primordium of the testis originates from the mesonephros, located behind the second to third lumbar vertebrae. By the 8th week, the testis forms, and by the 12th week, the mesonephros regresses. After that, the testis descends gradually with the development of the embryo. By the 28th week, the testicular ligament forms, connecting the lower pole of the testis to the scrotum. With the traction of the ligament and the transmission of intra-abdominal pressure, the testis also descends, passing through the internal and external ring orifices of the inguinal canal to the scrotum. At the internal ring orifice, with the descent of the testis, the peritoneum bulges outward to form a憩室-like tubular process, called the processus vaginalis. Normally, the distal end of the processus vaginalis wraps around the testis to form the tunica vaginalis of the testis, and after the testis passes through the external ring orifice, the processus vaginalis is also pulled into the scrotum. When the testis descends completely, the processus vaginalis is usually closed and regresses. If the processus vaginalis does not close completely, it can form an indirect hernia or hydrocele. In girls, the inguinal canal contains the round ligament, from the uterus to the labium majus, and at the time when the male fetus's testis descends, there is also a peritoneal processus vaginalis, called the Nuck tube, which passes through the inguinal canal and descends into the labium majus, with the same closure status as in boys. Due to different ages, the thickness of the processus vaginalis also varies, and it is extremely thin at the neonatal stage.
　　Increased intra-abdominal pressure and weak abdominal wall muscles are predisposing factors for inguinal hernia. Some reports indicate that 80% to 90% of newborns have an open peritoneal processus vaginalis at birth, and the time and mechanism of closure are not yet clear. However, the incidence of inguinal hernia in newborns after birth is not high. Therefore, it is believed that the presence of the processus vaginalis is only the basis for the occurrence of inguinal hernia, and there are still other predisposing factors such as increased intra-abdominal pressure, ascites, and weak abdominal wall muscles in premature infants, which promote the occurrence of inguinal hernia. Sometimes, after peritoneal dialysis or lateral ventricle-peritoneal shunting, it can cause children who previously had no symptoms to develop inguinal hernia or hydrocele.

　　Inguinal hernia in children can be complicated by acute mechanical intestinal obstruction. If a strangulated hernia forms, the intestinal tract can necrose, leading to peritonitis, and in severe cases, can cause infectious shock. Intestinal incarceration and strangulation are the most serious complications. Once intestinal incarceration occurs, systemic symptoms are severe, and there may be symptoms such as bilious vomiting and marked abdominal distension. The herniated organ appears black or dark blue, with rapid progression of the condition. In severe cases, there may be symptoms of poisoning, such as tachycardia, left shift of the nucleus, and disturbance of electrolytes and acid-base balance.

　　Most inguinal hernias in children occur before the age of 2, and symptoms and signs usually appear within a few months after birth, even at the first cry after birth. The initial main manifestation is a reducible mass in the inguinal region, which can significantly increase in size when crying, fussing, or due to other reasons causing increased intra-abdominal pressure. After quieting down, lying flat, or sleeping, the mass can shrink or completely disappear. Generally, it does not interfere with activity or affect the normal development of the child, unless there is an incarcerated hernia content. There is rarely pain or discomfort, and older children may report a feeling of坠胀.

　　The main signs are the reducible mass in the inguinal region, which is of varying sizes, smooth, and soft. Smaller masses are often located within the inguinal canal or protrude from the inguinal canal to the beginning of the scrotum,呈椭圆形. Larger ones can protrude into the scrotum, causing the scrotum to swell. Regardless of the location of the mass within the scrotum or the spermatic cord, there is no obvious boundary with the inguinal canal and the inguinal internal ring, as if there is a pedicle leading to the abdominal cavity. The contents are mostly intestinal, and the mass can be pushed back into the abdominal cavity by gently pushing upwards with the hand, and sometimes bowel sounds can be heard during the process. After the hernia contents are reduced, the external ring can be felt to be larger and relaxed. When stimulating infants and young children to cry or older children to cough, and at the same time inserting the finger into the external ring, a sense of impact can be felt. When pressing the inguinal canal internal ring with the fingertips, the mass cannot be prolapsed, and after removing the finger, the mass reappears. For children with a history of protrusion of a mass in the inguinal region who have consulted and were not found to have a hernia mass, careful examination of the local area can reveal that the affected side of the inguinal region is fuller than the opposite side, and the hernia contents can drop into the scrotum, making the affected side of the scrotum larger than the opposite side. When the index finger is placed above the spermatic cord at the external ring and moved left and right, the affected side of the spermatic cord can be felt to be thicker than the healthy side, and there is a feeling of silk friction.

　　Incidentally, children with incarcerated inguinal hernia often have a sudden increase and hardening of the hernia mass after a period of severe crying and coughing, which cannot be reduced and is painful. The contents of the incarcerated hernia are mostly intestinal, and after incarceration, symptoms such as abdominal pain, distension, vomiting, and cessation of排气 and defecation may occur. In cases with late consultation and绞窄, the scrotum may have swelling, redness, increased skin temperature, and tenderness. There may also be systemic manifestations such as fever, increased white blood cells, electrolyte imbalance, acid-base imbalance, and toxic shock.

　　Most hernias in children with inguinal hernia cannot be prevented, but it is possible to reduce the recurrence of hernias. The following suggestions can help reduce the recurrence of hernias:

　　1. Maintain a healthy weight and avoid overfeeding to cause obesity in infants and young children.

　　2. Drink more water regularly to keep the bowels open. For children over 3 months old, it is appropriate to increase the intake of soup and chopped vegetables to improve the smoothness of defecation.

　　The general symptoms of inguinal hernia in children are normal in routine examinations, but if there are systemic toxic symptoms, there may be infectious blood count, significantly increased white blood cells, and decreased platelets. This disease can be examined by ultrasound to determine the nature of the mass in the inguinal region. Patients can also undergo light transmission test and X-ray examination to assist in diagnosis and differential diagnosis.

　　Children with inguinal hernia should maintain regular and reasonable diet, mainly high-protein and high-vitamin foods. Choose high-nutritional value plant or animal proteins, such as milk, eggs, fish, lean meat, various bean products, and various fresh vegetables and fruits rich in vitamins and high nutritional value. If breastfed, the mother should pay attention to the above diet.

In theory, inguinal hernia in children has the possibility of spontaneous healing, and there are also a few cases of spontaneous healing in clinical practice. However, waiting for spontaneous healing is not advisable. The treatment of this disease includes non-surgical and surgical methods.

1. Non-surgical therapy

1. Hernia belt therapy:This method involves using a hernia belt to compress the internal ring and inguinal area, thereby preventing the hernia content from herniating, waiting for the peritoneal processus vaginalis to continue to close after birth, in the hope of increasing the chance of 'healing' of the hernia.

This method is often used for infants, but for larger hernias or children over 3 or 4 months old, the possibility of curing the hernia is extremely small. Moreover, cotton rope or hernia belts for infants and young children are not easy to fix, are prone to be soiled by urine and feces, and can compress or rub the skin. Long-term use not only makes the neck of the hernia sac frequently rubbed and become thick and tough, increasing the incidence of incarcerated hernia, but also may affect testicular blood flow or lead to local adhesions in the inguinal canal, thereby increasing the difficulty of surgery and complications. For infants under 6 months of age or those with serious diseases who are not suitable for surgery, hernia belt treatment can be adopted.

When fixing the hernia belt, attention should be paid to whether there is hernia content herniation and whether the tightness is appropriate. For unilateral hernia, the affected side is fixed first, and for bilateral hernia, both sides can be fixed in turn. After wearing the hernia belt, the child can walk around freely, without affecting urination and defecation. If there is contamination, it should be cleaned promptly. If the belt is not fitted properly or there is hernia content herniation, it should be refixed. The buttocks should be loosened and cleaned daily before wearing the belt again.

The hernia belt is generally fixed for 2 to 3 weeks in neonates and infants, and it is considered cured when there is no hernia content herniated. If herniation occurs again, continue to wear and fix for another month and repeat the examination. For children over 1 year old, it takes 2 to 3 months, and the hernia belt is loosened for about 1 week without herniation, which indicates that the hernia has closed. If there is still herniation, it can be fixed again. For older children with weak abdominal muscles and large hernial rings, if there is still herniation after 3 to 4 months of fixation, it is advisable to switch to surgical treatment.

2. Manual reduction for incarcerated hernia:Due to the short inguinal canal, weak abdominal muscles, and less abdominal muscle pressure on the inguinal canal in children, the neck of the hernia sac and the internal ring are softer than in adults, and the fibrous tissue at the external ring orifice is also more tender, with good vascular elasticity, and other anatomical and physiological characteristics, the venous return is often obstructed after incarceration, while the arterial blood flow is less affected. The pathological process from incarceration to necrosis of the hernia contents is relatively slow, which is conducive to manual reduction. Moreover, the edema around the hernia sac after incarceration makes the anatomical relationship unclear, making the already thin and easily torn hernia sac wall more fragile, which increases the difficulty of surgery. Therefore, for those incarcerated for 12 hours or less, surgery is generally not urgent, and manual reduction can be attempted.

However, the following situations should be considered as contraindications to manual reduction: those with incarceration exceeding 12 hours; those who have failed to undergo manual reduction treatment; neonatal incarcerated hernia, where it is difficult to determine the time of incarceration; those with local or scrotal redness and pain; those with symptoms of strangulation such as hematochezia, or those with poor general condition, severe dehydration, acidosis, and signs of peritonitis; the incarcerated hernia contents are solid organs, especially in female infants, the incarcerated hernia contents are often ovaries and fallopian tubes, which are difficult to reduce and are prone to injury.

Second, surgical treatment

It is currently believed that surgery is the best method for treating inguinal hernia. As children grow older, the hernia mass gradually increases, and it can become incarcerated or strangulated at any time, affecting testicular development and even posing a threat to life. Therefore, in principle, early surgical treatment is recommended after the diagnosis of an indirect inguinal hernia, and the common surgical methods are as follows.

1. High Ligation of Hernia Sac:The inguinal canal of infants and young children is short, and the hernia sac can be ligated at a high position without cutting the external ring. Therefore, it is usually incised at the lower abdominal skin transverse crease below the lateral edge of the rectus muscle on the affected side, or at the lateral side of the pubic tubercle and the surface projection of the external ring. Cut the skin, subcutaneous tissue, and fascia, expose the spermatic cord, and cut the cremaster muscle to find the hernia sac in front of the spermatic cord. After cutting the hernia sac and exploring it, cut it transversely, separate the proximal part to the neck of the hernia sac, suture it with a purse-string or '8' shaped suture, remove the excess hernia sac, and leave the distal part open. After stopping the bleeding, suture the incision in layers and reconstruct or narrow the external ring. Since the incomplete closure or incomplete closure of the peritoneal processus vaginalis and increased abdominal pressure are the main causes of infantile indirect inguinal hernia, the weakened abdominal wall is not the main cause. High ligation of the hernia sac at the neck can cure it. Especially for infants and young children, high ligation of the hernia sac is the most commonly used treatment.

2. Intra-abdominal Hernia Sac Dissection (LaRaque Procedure):Make a transverse incision below the lateral edge of the rectus muscle on the affected side, cut the skin, subcutaneous tissue, and fascia, and separate the muscles layer by layer. Make a transverse incision in the peritoneum above the internal ring to expose the internal ring. Make a transverse incision in the peritoneum below and behind the internal ring to connect the upper and lower incisions of the internal ring, completely separate the hernia sac from the peritoneal cavity, separate the spermatic vessels and vas deferens, and suture the peritoneum continuously with silk thread (the hernia sac is left outside the peritoneal cavity), and then suture the incision layer by layer. This method is easy to find the hernia sac and ligate it at a high position, without the disadvantage of low ligation position. However, this method is more invasive locally and in the abdominal cavity than the previous method, and there is a risk of abdominal adhesion. Therefore, it is only suitable for small infants and young children with hernias that are difficult to find the hernia sac through the conventional extraperitoneal approach and (or) recurrent hernias.

3. Ferguson Hernia Repair:It is suitable for large hernias with weakened abdominal wall that require strengthening the anterior wall of the inguinal canal.

4. Bilateral Hernia SurgeryAdditional operation may be required, and a transverse incision across both sides of the external ring or separate incisions on both sides for high ligation of the hernia sac can be chosen. If bilateral hernia repair is required, oblique incisions should be made on both sides to perform the operation.