Adult inguinal hernia

　　One, Etiology

　　1. Anatomical defects in the inguinal canal area are the basis for the occurrence of adult indirect inguinal hernia.

　　2. Acquired damage and the loss of physiological defense function of the muscle in the inguinal canal area are one of the bases for the occurrence of adult indirect inguinal hernia.

　　Additionally, when the transversalis fascia and transversus abdominis muscle contract, the inguinal ligament and the internal ring are pulled outward and upward together, thus closing the internal ring of the inguinal canal deep to the internal oblique muscle, preventing the formation of the hernia sac. Due to various reasons, when the occlusive action of the transversus abdominis muscle and the internal oblique muscle on the internal ring is weakened or lost, it can also lead to the occurrence of acquired indirect inguinal hernia.

　　3. Increased Intra-abdominal Pressure Increased intra-abdominal pressure is one of the important factors promoting the occurrence of various abdominal hernias. Normally, when a person stands upright, the internal organs sag into the lower abdomen and pelvis, and the pressure on the abdominal wall in the inguinal area is three times greater than when lying flat, which has the effect of promoting the formation of indirect inguinal hernia. In certain physiological and pathological conditions (such as heavy physical labor, chronic constipation, liver cirrhosis ascites, chronic bronchitis, emphysema, etc.), the increased abdominal pressure persists, which is bound to destroy the anatomical structure and physiological defense function of the inguinal area. At the same time, high intra-abdominal pressure can cause the internal organs to break through the internal ring directly, enter the inguinal canal, and form an indirect inguinal hernia.

　　4. Abnormalities in Biology Abnormalities in biology are auxiliary factors leading to the occurrence of indirect inguinal hernia. Clinical practice has confirmed that some people with anatomical defects of the inguinal canal and those with long-term increased intra-abdominal pressure do not develop indirect inguinal hernia, on the contrary, many people who do not have congenital anatomical defects or increased intra-abdominal pressure, and engage in light physical labor or intellectual labor, can also suffer from indirect inguinal hernia. It is obvious that congenital anatomical defects and long-term increased intra-abdominal pressure are difficult to fully explain the pathogenesis of indirect inguinal hernia.

　　Two, Pathogenesis

　　Although the peritoneal pouch of the adult has been sealed off, the inguinal canal area is a vulnerable spot on the abdominal wall without muscular protection. Due to the passage of the spermatic cord or uterine round ligament, a spiral stair-like structure of the inguinal canal is formed here, and the canal does not have a truly complete wall. There is a certain distance between the arch-shaped edge formed by the lower edge of the internal oblique muscle and the transversalis fascia arch of the upper wall of the inguinal canal and the inguinal ligament of the lower wall of the inguinal canal, generally 0.5 to 2.0 cm (about 15% of people above 2.0 cm), with an average of 0.7 cm, making the inguinal canal area a vulnerable spot without protection from the abdominal muscles. Especially the internal ring, that is, the inner opening of the inguinal canal, is a gap without a complete structure formed on the transversalis fascia when the spermatic cord or uterine round ligament passes through it, which is an important weakness of the lower abdominal wall. When the pressure on the internal organs is sufficient, it is easy to break through this opening into the inguinal canal to become an indirect hernia. Since the internal ring and inguinal canal of women are relatively narrow, they rarely develop indirect hernias.

　　When the aponeurosis arch of the transversus abdominis and the insertion point of the internal oblique muscle are high or underdeveloped, muscle damage, incisions in the abdominal wall causing nerve damage, leading to muscle atrophy affecting its contraction, as well as inflammation adhesions limiting its movement, it becomes difficult for it to approach the inguinal ligament, resulting in the failure of its physiological protective effect. When the pressure inside the abdomen is sufficient to break through this orifice into the inguinal canal, even though the peritoneal processus vaginalis has been sealed, the parietal peritoneum can protrude through the inguinal canal to form a new hernia sac, leading to the occurrence of acquired indirect inguinal hernia.

　　Whether it is a child or an adult with an indirect inguinal hernia, intra-abdominal hypertension plays an important role in its occurrence and development. Moreover, intra-abdominal hypertension and the weakness of the abdominal wall resistance are often the true causes of acquired indirect inguinal hernia. The incarceration of an indirect inguinal hernia is also the result of a sudden increase in intra-abdominal pressure.

　　Since the composition of the inguinal canal is mostly composed of fascia, aponeurosis, and ligaments, etc., the strength of these tissues is related to collagen metabolism. Therefore, in the past 20 years, many scholars have conducted a large number of studies on the etiology and pathogenesis of inguinal hernia from the biological perspective of tissues. The results show that the amount of hydroxyproline in the tissue of inguinal hernia patients is reduced, collagen production is low, and the proliferation rate of fibroblasts is suppressed. Some scholars have studied the collagen fibers in the anterior sheath of the rectus abdominis muscle near the inguinal area of inguinal hernia patients and found that the diameter of the collagen fibers near the inguinal area of the anterior sheath of the rectus abdominis muscle in the former is thin and weak, with less collagen content, and the content and binding rate of hydroxyproline are also significantly lower than those in the latter; in the fibroblast culture test, the proliferation rate of the latter is higher than that of the former.

　　Cannon and Read (1981) found that severe smokers not only have a high incidence of emphysema and lung cancer, but also a high incidence of inguinal hernia. They believe that smoking can cause a decrease in the concentration of inhibitory proteins that dissolve in the blood (such as alpha-1-antitrypsin), leading to an increase in collagen decomposition. At the same time, protein-dissolving enzymes (including elastase) produced in the lungs enter the blood circulation, causing damage to the body's collagen and elastic fibers, leading to emphysema in the lungs. In the inguinal area, it also destroys the transversalis fascia and the aponeurosis of the transversus abdominis muscle, causing the occurrence of hernia. Some people also believe that inguinal hernia may be a local manifestation of systemic collagen metabolic disorder. An abnormal state where collagen decomposition exceeds synthesis metabolism is bound to cause the connective tissue structure that constitutes the inguinal canal to become weak, becoming the pathological basis of inguinal hernia.

　　1. Incarcerated hernia:It is a common complication of inguinal hernia. Patients (some may not have a history of inguinal hernia) experience a sudden increase and hardening of the hernia mass, which cannot be reduced into the abdominal cavity under conditions of intense exertion, severe coughing, or defecation, resulting in significant and severe pain. If the incarcerated hernia content is the intestine, abdominal colic, nausea, vomiting, constipation, and abdominal distension, etc., symptoms of intestinal obstruction may occur.

　　2. Strangulated hernia:If an incarcerated hernia is not treated in time, further development will lead to strangulated hernia, causing serious complications such as intestinal perforation, peritonitis, etc. Strangulated hernia usually occurs when the incarcerated time exceeds 24-48 hours, but in a few severe cases, it can occur before 24 hours. Strangulated hernia often has toxicemia manifestations, such as fever, rapid pulse, and even toxic shock; severe water, electrolyte, and acid-base disturbances; local skin redness, swelling, pain, and other inflammatory manifestations. In the late stage, the intestinal wall may undergo ischemic necrosis and perforation, with extravasation of intestinal contents, initially causing intracystic infection, followed by acute cellulitis or abscess of the covering layers, and infection extending to the peritoneum can cause acute diffuse peritonitis.

　　1. Mass in the inguinal region:The important clinical manifestation of inguinal hernia is a mass protruding in the inguinal region. In the early stage, the mass is small and can be confined to the inguinal region. With the progression of the disease, the mass gradually increases and enters the scrotum, forming a typical inguinal hernia mass similar to a pear shape, with a narrow upper end and an oblique entry into the inguinal canal, and a wide and丰满 lower end. Easily reducible inguinal hernia, the mass often appears when standing, walking, working, or coughing, and automatically retracts into the abdominal cavity during rest or lying down, or disappears after massage. Incompletely reducible inguinal hernia is due to the frequent friction between the hernia contents and the inner wall of the hernia, which causes mild inflammation and gradually forms adhesions between them, so that the hernia contents cannot be completely pushed back into the abdominal cavity. Therefore, the mass only shrinks to varying degrees and does not completely disappear with changes in body position or abdominal pressure, and is common in patients with long course and large hernia sac.

　　2. Local distension and pain:Incompletely reducible inguinal hernia, in addition to the mass in the inguinal region, usually has no special symptoms, occasionally feels local distension and pain, and even causes hidden pain in the upper abdomen or around the umbilicus. Incompletely reducible inguinal hernia is characterized by varying degrees of acid distension and坠感，these symptoms occur with the appearance of the mass and subside when the mass disappears.

　　3. Dyspepsia or chronic constipation:This symptom is more common in sliding inguinal hernia. Since the cecum, sigmoid colon, or bladder and other organs have become part of the hernia sac, patients often have some 'dyspepsia' and chronic constipation, as well as symptoms of incomplete urination. Sliding hernias are generally large masses, more common in men over 40 years old, and more common on the right side than the left.

　　1. Change bad living habits and cultivate a healthy lifestyle

　　(1) Quit smoking: Smoking not only causes chronic cough and increases intra-abdominal pressure but also inhibits the synthesis of collagen fibers and promotes degenerative changes in the abdominal muscles, which is one of the important predisposing factors for inguinal hernia in the elderly. Therefore, the elderly are best not to smoke or reduce smoking.

　　(2) Maintain smooth defecation: Constipation is one of the important causes of increased intra-abdominal pressure, so maintaining smooth defecation is an effective method for preventing inguinal hernia. The elderly should eat more vegetables and fruits, drink water in a fixed amount, and develop the habit of regular defecation.

　　2. Actively prevent and treat diseases that increase intra-abdominal pressure

　　Chronic bronchitis, emphysema, benign prostatic hyperplasia, and so on.

　　A small number of patients, due to small sacs and不明显突出肿块, may not attract attention or be palpated, and they often experience pain in the lower abdomen or inguinal region of unknown cause, as well as the coexistence of other hernias or special types of indirect hernias, such as Richter, Littre hernias, etc., making timely diagnosis very difficult. For these cases, the following auxiliary examinations can be used for assistance.

　　1. Herniography (Herniography):It can diagnose early inguinal hernia and is the best method for differential diagnosis for patients with pain in the inguinal region of unknown cause. Before surgery, it can accurately diagnose the type and number of hernias to assist in choosing the surgical method, effectively reducing the occurrence of residual hernias. After surgery, hernia angiography can not only diagnose recurrent inguinal hernia but also accurately differentiate residual hernias, new hernias, or true recurrent hernias, providing a more objective basis for effective surgical treatment.

　　2. Ultrasound examination:Color Doppler can detect the bilateral lower abdominal wall arteries in inguinal hernia patients and determine whether the patient has an indirect or direct hernia based on whether the sac neck and sac are located on the inside or outside of the lower abdominal wall artery. It can also observe the blood supply of the hernia contents, blood flow velocity, to understand whether there is strangulation or necrosis.

　　3. Standing X-ray film:It shows intestinal bloating, stepped gas-liquid levels, and signs of intestinal obstruction, which help clarify the diagnosis in incarcerated inguinal hernia.

　　4. CT scan:It has important value in the diagnosis and differential diagnosis of indirect inguinal hernia between the inguinal canal and the abdominal wall, femoral hernia, and obturator hernia.

　　1. Generally, patients can consume fluid foods such as congee, thin lotus root powder, vegetable juice, and fruit juice within 6 to 12 hours after surgery. On the second day, they can switch to soft or regular foods, such as soft rice, noodles, egg cakes, and chopped and cooked vegetables and meats, focusing on nutritious, easy-to-digest, and light meals.

　　2. In terms of diet, you can eat more nutritious foods and more coarse fiber foods, such as leeks, celery, cabbage, coarse grains, beans, bamboo shoots, and various fruits.

　　3. Keep the bowels smooth, and you can use jellyfish, bitter melon, sweet potatoes, etc.

　　4. Avoid foods that can cause intestinal bloating after surgery, such as milk, soy milk, eggs, etc.

　　5. Avoid smoking, drinking, greasy, fried, moldy, and salted foods.

　　6. Avoid spicy foods such as garlic and mustard.

　　First, treatment

　　1. Wearing a hernia belt:Adult indirect inguinal hernia cannot heal spontaneously and may lead to incarceration or strangulation, so surgical treatment should be performed. However, in special cases where surgery is not advisable, it can be temporarily delayed. During the temporary delay period, a hernia belt can be worn to tightly compress the hernia ring. Because long-term wearing of a hernia belt can cause adhesion between the hernia contents and the neck of the hernia sac, it is easy to lead to a recurrent hernia, so it is generally not recommended.

　　(1) Temporary delay conditions: ① Pregnant women over 6 months, as the uterus often pushes the intestinal loops upward to the upper abdomen, the chance of hernia occurrence is less; ② Patients with extreme weakness or serious cardiovascular and liver, kidney, and other important organ diseases who cannot tolerate anesthesia and surgery; ③ Patients with skin diseases at the surgical site; ④ Patients with obvious triggers of hernia occurrence that have not been controlled, such as benign prostatic hyperplasia, liver cirrhosis ascites, chronic bronchitis, emphysema, etc.; ⑤ Patients with active stages of multiple diseases, such as diabetes, tuberculosis, etc. (Patients who must undergo surgical treatment for hernia incarceration or strangulated hernia are excluded); ⑥ Patients with soft tissue infection foci in the inguinal region.

　　(2) Contraindications of hernia belt: The following situations should be considered as contraindications for the use of a hernia belt: ① Irreversible, incarcerated, intestinal obstruction, and strangulated hernia are absolute contraindications; ② Large hernias or those with very large sac orifices; ③ Patients with hydrocele of the cord or incomplete descent of the testes are not suitable for hernia belt treatment.

　　(3) Method of using a hernia belt: The hernia belt must be customized according to the patient's body shape and the size of the hernia sac orifice. When using it, first return the hernia contents to the peritoneal cavity, cover the hernia cap over the inguinal canal internal ring at the inguinal canal, so that the inguinal canal is exactly closed to prevent the hernia mass from protruding, and then fix the waistband. The hernia belt is generally worn during the day and removed at night.

　　2. Surgical treatment:If the indirect inguinal hernia is not treated in time, the defect in the abdominal wall will gradually worsen, not only affecting labor capacity but also making it difficult for future surgical treatment.

　　The surgical principle of indirect inguinal hernia is mainly: high ligation and reinforcement of the hernia sac, and repair of the inguinal canal wall.

　　(1) High ligation of hernia sac: High ligation refers to ligating above the neck of the hernia sac, resecting the proximal hernia sac, and the distal hernia sac can be resected or left in place according to the size of the hernia sac. It is only applicable to adult patients with strangulated indirect hernia with intestinal necrosis. The purpose of high ligation is to eliminate the residual peritoneal processus vaginalis and restore the normal state of the peritoneal cavity in the inguinal region.

　　Operation method: Incise the hernia sac, examine and return the contents, then strip the hernia sac to the neck of the hernia sac, suture the inner purse-string, and fix it to the deep surface of the oblique abdominal muscle.

　　Some people do not open the hernial sac when performing high-position hernial sac ligation. Irving adopts the method of not removing the hernial sac, flipping it into the abdominal cavity and suturing it outside. Potts twists the hernial sac before ligation to achieve the purpose of high-position ligation. There are also reports that it is necessary to cut the inner sheath of the spermatic cord, separate to the pre-peritoneal fat level, or confirm the level of the internal ring and the inferior epigastric artery to achieve the purpose of high-position ligation, but it requires certain experience and skill. Generally speaking, no matter 'inner pouch', 'outer pouch', or other methods of treatment, as long as the ligature is cut and the residual end can retract to the deep surface of the transversalis muscle and no longer appear in the surgical field, it is acceptable. It is not appropriate to pass the ligature through the transversalis muscle and the internal oblique muscle and fix it, as this not only makes the muscle fibers prone to tearing in the future, but also affects the movement of these muscles and loses some of the occlusive function.

　　(2) Repair of the inguinal canal wall: The repair of the inguinal canal wall actually utilizes different adjacent tissues to strengthen the defects in the anterior or posterior wall of the inguinal canal, that is, the weak part of the abdominal wall, and to close the protruding channel of the inguinal canal to seal the indirect inguinal hernia. Due to the different use of adjacent tissues and repair methods, a large number of surgical methods have been derived and named after the founders of the methods. Clinically, there are four commonly used traditional methods.

　　①Ferguson method: After ligation of the hernial sac at a high position, suture the inferior margin of the internal oblique muscle, the transversalis aponeurosis arch, and the conjoint tendon to the inguinal ligament on the superficial surface of the spermatic cord to strengthen the anterior wall of the inguinal canal and eliminate the weak area between the two. This method is suitable for small indirect inguinal hernia with no obvious defect in the transversalis aponeurosis arch and a healthy posterior wall of the inguinal canal.

　　②Bassini method: After ligation of the hernial sac at a high position, free the spermatic cord and lift it up, suture the inferior margin of the internal oblique muscle, the transversalis aponeurosis arch, and the conjoint tendon to the inguinal ligament on its deep surface to strengthen the posterior wall of the inguinal canal, and displace the spermatic cord between the internal oblique muscle and the external oblique aponeurosis. It is suitable for adults and indirect inguinal hernia with significant weakening of the posterior wall of the inguinal canal. To judge the strength of the posterior wall of the inguinal canal, the transversalis aponeurosis, and the transversalis fascia, you can use your fingers to extend into the internal ring to the lateral abdominal wall and push it out towards the body surface to feel its strength. This operation is currently more commonly used.

　　③Halsted method: Free the spermatic cord and lift it up, suture the inferior margin of the internal oblique muscle, the transversalis aponeurosis arch, and the conjoint tendon to the inguinal ligament on its deep surface, and then overlap or overlap the superior and inferior leaves of the external oblique aponeurosis on the deep surface of the spermatic cord. The spermatic cord is displaced to the subcutaneous tissue. Compared with Bassini, this method strengthens the posterior wall of the inguinal canal, but the spermatic cord is under the skin, which may affect its and testicle development, so it is not suitable for adolescents and is often used for elderly patients and indirect inguinal hernia with severe weakness of the abdominal wall muscles.

　　④McVay method: At the posterior wall of the inguinal canal, incise the transversalis fascia at the superior margin of the inguinal ligament, suture the superior margin of the incision along with the inguinal aponeurosis arch and conjoint tendon to the pubic tubercle ligament behind the spermatic cord, and repair the suture site deep to the superior branch of the pubic bone. In addition to strengthening the posterior wall of the inguinal canal, it also changes the direction of propagation of abdominal intra-pressure, strengthens the inguinal triangle, and indirectly seals the femoral ring. It is suitable for large indirect inguinal hernia and direct inguinal hernia.

　　However, it must be noted that this surgical method does not have the function of closing the internal ring. For those with a significantly enlarged internal ring, it is still necessary to repair the internal ring or suture the superior margin of the transversalis fascia to the anterior wall of the femoral sheath to reduce the internal ring to a size that can only pass the spermatic cord. This method of repair is deep in the location, and attention should be paid to avoid injury to the femoral vessels.

　　Since the modern era, many scholars have conducted in-depth research on the anatomy, physiology, pathogenesis, and pathophysiology of inguinal hernia, and proposed that traditional inguinal hernia repair techniques represented by Bassini, Halsted, Ferguson, and McVay have many defects: A. Traditional hernia repair only pays attention to strengthening the anterior or posterior wall of the inguinal canal, but does not include the transversalis fascia layer, especially the repair of the internal ring (leaving an enlarged internal ring), which fails to correct or close the defect where the hernia occurs. According to Pascal's principle of physics, the defect with the largest content pressure after closing the window, hence it retains the basis for postoperative recurrence; B. Traditional hernia repair, especially McVay surgery, often has a large tension after suture repair, which is easy to cause tissue tearing or affect healing due to poor blood circulation; C. Traditional hernia repair often uses the inguinal ligament as a fulcrum for repair, while the ends of this ligament have a large span, forming a suspension structure, which often cannot pull the 'conjoint tendon' to one side of the ligament, but rather bring them close together. Such suture repair with a certain tension can only maintain for a few months; D. The inguinal ligament is actually part of the aponeurosis of the external oblique muscle in the anatomical level, and it is sutured to the inferior margin of the internal oblique muscle arch and the transversalis aponeurosis arch above the plane of the defect, which is a repair at two different anatomical levels, and it disrupts the normal anatomy of the inguinal canal; E. Traditional inguinal hernia repair surgery can cause displacement and fixation of the internal oblique and transversus abdominis muscle arc, which disrupts the normal physiological defense mechanism of the inguinal canal produced by the contraction of these muscles; F. Traditional inguinal hernia repair surgery can lead to the occurrence of femoral hernia. According to Glassow (1970), more than 25% of patients with femoral hernia have a history of inguinal hernia repair surgery because traditional inguinal hernia surgery uses the inguinal ligament for repair, and the ligament is pulled up and sutured with tension, causing the femoral ring to open up, providing an easy way for hernia protrusion.

　　The current view of hernia repair is to focus on the repair of the internal ring, emphasizing tension-free suture at the same anatomical level to restore the pathoanatomical structure of the hernia to a normal anatomical structure. At the same time, considering the physiological defense mechanism of the inguinal region, efforts should be made to restore its normal physiological function. Since the transversalis fascia is the main barrier to prevent hernia occurrence, pathological anatomical changes of the transversalis fascia appear first and are the most severe after the hernia occurs. Therefore, in recent years, the focus of hernia repair has been on repairing the damaged transversalis fascia to restore its anatomical integrity and continuity. The surgical methods have also been improved on the basis of traditional surgery.

　　(3) Shouldice method: Created by Canadian Shouldice and his collaborators (1950-1953), hence also known as the Canadian hernia repair. The key points of repair are to incise the transversalis fascia from the internal ring to the pubic tubercle, divide it into two leaves, suture the edges of the internal ring to reduce its size, and first suture the lower leaf to the deep surface of the upper leaf. Then overlap the upper leaf on the shallow surface of the lower leaf and suture it to the inguinal ligament, which is the key point of the operation. The external surface will suture the transversus abdominis muscle and the arcuate margin of the internal oblique muscle in two layers to the inguinal ligament, a total of 4 layers of sutures.

　　Operation method: Free and lift the spermatic cord, use fingers to probe the degree and extent of the weakness of the transversalis fascia through the internal ring, incise the transversalis fascia from the internal ring to the pubic tubercle along the direction of the inguinal ligament, and remove its weak part. Free the lower lobe to the inguinal ligament, and the upper lobe to the deep inner side of the transversus abdominis muscle to reach the posterior fascia of the rectus abdominis muscle.叠瓦式缝合健全的上下叶，即下叶切缘从耻骨结节处连续向外缝合于上叶的深面，直到构成一个较紧的内环，以恰能通过精索为度，然后将缝线再按相反方向把上叶的切缘缝合到腹股沟韧带上，并返回到耻骨结节处与第1针缝线的另一端打结。再将腹内斜肌下缘、腹横腱膜弓和联合腱缝合于腹股沟韧带和腹外斜肌腱膜的深面，最后在精索的浅面缝合腹外斜肌腱膜。This method emphasizes the role of the transversalis fascia in hernia repair and is suitable for indirect inguinal hernia with a weak posterior wall, thin transversalis fascia, and dilated internal ring.

　　(4) Madden method: Focuses on incising the posterior wall of the inguinal canal, removing the weak part of the transversalis fascia, and intermittently suturing the transversalis fascia to reconstruct the internal ring and the posterior wall.

　　(5) Panka method: Emphasizes the precise exposure and repair of the internal ring. Find the transversalis aponeurosis arch deep to the arcuate margin of the internal oblique muscle, suture it to the iliopectineal ligament, and then suture it to the inguinal ligament to strengthen the repair.

　　(6) Preperitoneal hernia repair: First introduced by Nyhus, its advantage is that it can ligate the hernial sac at a higher position without changing or destroying the anatomical structure and physiological closure mechanism of the inguinal canal, and without incising the transversalis fascia at the inguinal canal, the lower edge of the internal oblique muscle, the transversalis aponeurosis arch, and the conjoint tendon can be sutured to the inguinal ligament or pubic tubercle ligament.

　　Operation method: Make a transverse incision 3 to 4 cm above the pubic tubercle above the inner ring, with one-third of the incision in front of the rectus abdominis muscle. Incise the subcutaneous tissue, anterior sheath of the rectus abdominis muscle, external oblique muscle, internal oblique muscle, and transversus abdominis muscle, and pull the rectus abdominis muscle inward. Incise the transversalis fascia transversely to enter the pre-peritoneal space, exposing the hernial sac and pubic tubercle ligament, iliopectineal ligament, inguinal ring, and other structures. After ligating the hernial sac at a high position, the iliopectineal ligament can be sutured to the pubic tubercle ligament to close the inguinal ring. For indirect inguinal hernia and direct inguinal hernia, after suture of the anterior and posterior feet of the transversalis fascia suspension band, the transversalis aponeurosis is sutured to the iliopectineal ligament or Cooper ligament.

　　(7) Tension-free hernia repair (tension-free repair of hernia): In order to repair the weak part of the inguinal region, traditional hernia repair techniques often suture together tendons, fascia, muscular tissue, or mucosal tissue of different anatomical levels, resulting in the destruction of the local tissue structure after repair, increased tissue tension, and tissue metabolic disorders, which become one of the factors leading to surgical failure or hernia recurrence. In the 1980s, based on the theory that the defect and destruction of the transversalis fascia are the fundamental causes of inguinal hernia, Lichtenstein et al. proposed the concept of tension-free hernia repair by using a local implantable synthetic polymer mesh instead of traditional repair. Over 20 years of clinical practice have proven that tension-free hernia repair has the advantages of not disturbing the local anatomical relationship, no suture tension, small trauma, mild postoperative pain and discomfort, quick recovery, and low recurrence rate.

　　①Stoppa method (pre-peritoneal mesh laying technique): French doctor Stoppa (1975) used polyester as the material, folded a large non-absorbable patch into an umbrella shape, inserted it through the internal ring orifice into the space between the peritoneum and transversalis fascia (underlay), expanded it around the internal ring orifice, and attached it to the abdominal wall with the pressure of the abdominal cavity, to strengthen the fragile transversalis fascia. After fibrous hyperplasia, it is fixed to the tissue. According to the range of the defect, the patch covers the pre-peritoneal space below the arcuate line on the unilateral or bilateral side, and should extend below the pubic muscle hiatus without suture.

　　Due to its longer surgical incision and extensive anatomical dissection range, it is also known as the 'giant prosthetic reinforcement of the visceral sac surgery (giant prosthetic reinforcement of the visceral sac, GPRVS)'. It is often used for recurrent hernias, giant hernias (including incisional hernias, umbilical hernias, and stoma adjacent hernias) and bilateral hernias.

　　②Lichtenstein method (flat patch repair technique): The high ligation of the hernia sac and the free margin are the same as the traditional technique, repairing the internal ring orifice, placing the mesh flatly on the posterior wall of the inguinal canal after freeing the spermatic cord, and making continuous suture around the mesh edge.

　　Lichtenstein et al. (1989-1993) performed Lichtenstein surgery on 3125 adult inguinal hernia patients, with only 4 recurrences in 9 years, making it the most commonly used tension-free hernia repair technique in foreign countries (small hernia).

　　③Meshplug method (mesh plug filling repair technique): Based on the characteristics of a smaller inguinal hernia ring and a sound posterior wall, Shulman and Lichtenstein (1994) used a rolled patch of polypropylene to repair the defect, with the edge of the 'plug' fixed around the periphery with 2 to 5 non-absorbable sutures. They advocate the use of the mesh plug filling method for recurrent inguinal hernias and direct hernias with a diameter less than 3.5 cm.

　　④ Rutkow method (tension-free hernia repair with hernial ring filling): The high-position free sac is similar to the traditional method, exposing the hernial ring orifice. If the sac is small, it does not need to be ligated; if the sac is too large, it can be transected 4-5cm from the hernial ring, the proximal sac sutured closed, and the distal sac carefully hemostatized and left in place. The sac is reversed from the hernial ring orifice and returned to the peritoneal cavity, a conical filling plug (plug) is placed in the hernial ring orifice, and the conical base of the filling plug is below the hernial ring orifice. The outer leaf edge of the conical filling plug is sutured and fixed to the transversalis fascia; the spermatic cord is freed, and a shaped mesh (mesh) is placed flatly behind the spermatic cord. A hole is left in the mesh for the spermatic cord to pass through, and the mesh is sutured and fixed around the surrounding tissue to prevent the mesh from curling. This procedure is simple, minimally invasive, has few complications, a low recurrence rate, can be completed under local anesthesia, and allows for early ambulation and quick return to daily activities and work, and has become a classic tension-free hernia repair technique.

　　⑤ Prolene hernia system (PHS): The Prolene hernia system is a standardized product consisting of three parts: the bottom layer, which applies preperitoneal repair methods to the pubic muscle orifice; the middle body, resembling a conical 'plug', used to repair the hernial ring; and the top layer, used to repair the posterior wall of the inguinal canal.

　　(8) Laparoscopic repair of indirect inguinal hernia: Based on the theoretical basis of tension-free repair and the advent of tissue-compatible high-molecular material meshes, it provides the necessary conditions for the implementation of laparoscopic hernia repair.

　　① Sac neck ligation: Through the umbilical laparoscopic observation port, the hernial orifices in both inguinal regions are observed. External pressure with fingers in the external inguinal canal helps to locate the hernial orifice. If there is hernial content, it is reduced externally. After confirming that the sac is empty, another puncture incision is made at the semilunar line at the same level as the umbilicus on the same side, a 12mm trocar and cannula are inserted, and a stapler is inserted through it. The lateral end of the hernial orifice is clamped with forceps, and a clip is installed every 5-6mm to close the hernial orifice until close to the spermatic cord.

　　② Transabdominal preperitoneal laparoscopic herniorrhaphy: This procedure is based on Stoppa's open preperitoneal repair, where the peritoneum above the defect is cut open under the laparoscope through the abdominal cavity, the preperitoneal space is dissected, the sac is excised, and an appropriately sized patch is selected to cover the internal ring orifice and the direct hernia triangle area, and then the patch is fixed with staples.

　　This method is simple to operate, can avoid secondary injury caused by open surgery, has fast recovery, mild pain, and can simultaneously handle bilateral hernias or contralateral subclinical hernias during surgery. The postoperative complications are few and the recurrence rate is low, especially suitable for complex hernias and hernias that recur multiple times. The main complications include hydrocele of the sac, urinary retention, hematoma and emphysema in the inguinal region, scrotal hematoma, etc.

　　③ Intraperitoneal onlay mesh hernioplasty (intraperitoneal onlay mesh hernioplasty): This method covers the inner surface of the defect in the peritoneum with a polypropylene patch directly after the hernia contents are returned by laparoscopy and fixed. The surgery has minimal injury, simple operation, and satisfactory short-term efficacy. However, due to direct contact between the patch and the viscera, it can cause intestinal adhesion or even fistula. This technique was once abandoned, but with the introduction of anti-adhesion patches (e-PTFE), it is now widely used again.

　　④ Totally extraperitoneal hernioplasty (totally extraperitoneal hernioplasty): The main difference of this technique from the preperitoneal repair through the abdomen is the establishment of 'pneumoperitoneum' outside the peritoneum and the completion of the separation operation of the preperitoneal space, avoiding various complications caused by intraperitoneal operations. It also has the advantages of preperitoneal repair, and its application in clinical practice is increasing. However, due to the risk of injury caused by anatomical scar and adhesion in patients with a history of abdominal surgery and recurrent hernias, it is particularly cautious to choose the totally extraperitoneal repair method.

　　Laparoscopic hernia repair, as a completely new surgical technique, is gradually being carried out worldwide. This type of surgery causes minimal postoperative discomfort, mild pain, and rapid recovery, and can simultaneously check and treat bilateral inguinal hernias and femoral hernias. Laparoscopic hernia repair can avoid the occurrence of nerve injury and ischemic orchitis caused by the original approach in recurrent hernias, and an increasing number of patients and surgeons are choosing laparoscopic hernia repair surgery.

　　3. Surgical complications:In addition to the common complications of general surgical operations, the following main complications may occur after inguinal hernia surgery.

　　(1) Hematoma or residual hernia sac fluid: Hematomas often occur when the sac is large and free, with a large stripping surface. If the stripping is limited to the sac neck area and the sac body is left in place, the incidence can be reduced. If the sac body is originally left in place but the incision is too small, it may lead to fluid accumulation within the sac. Both hematoma and residual sac fluid can manifest as a mass in the surgical area or scrotum early after surgery, which may be mistaken for a failure of hernia repair and recurrence, but the mass does not extend into the abdomen and its upper boundary is identifiable. Small hematomas can be absorbed spontaneously, while large ones often require aspiration. Residual sac fluid rarely absorbs spontaneously and can be tried by aspiration; if ineffective, surgery is often required to open the fluid sac, making it easier for the fluid to be absorbed by surrounding tissues.

　　(2) Burning pain in the inguinal region: The site of burning pain may involve the root of the penis, upper scrotum (female mons pubis, labia majora), and the upper inner skin of the thigh. Walking, bending over, and hyperextension of the hip can worsen the burning pain. The causes of concurrent burning pain include injury to the ilioinguinal nerve and the genital branch of the genitofemoral nerve (including ligation, suture, scar traction, or compression, etc.). The former often occurs during the incision of the lateral aponeurosis of the external oblique muscle, the external ring, or during the incision or suture of the cremaster muscle fascia; the latter is often related to the incision or suture of the cremaster muscle fascia.

　　(3) Weakness of Abdominal Muscles in the Surgical Area: This is usually a consequence of iliohypogastric or ilioinguinal nerve injury and becomes one of the causes of recurrence after inguinal hernia surgery. The most common site of iliohypogastric nerve injury is after freeing the superior upper lobe of the oblique aponeurosis after incising it, and it can also occur when lifting the residual neck of the hernia sac that has been ligated and fixing it deep to the transversus abdominis muscle, as the fixing suture may tie the nerve located on the surface of the internal oblique muscle.

　　(4) Testicular Cord Injury: Dissection of the hernia sac and dissection of the testicular cord for strengthening the posterior wall of the inguinal canal can both cause testicular cord injury. If the internal artery of the testicular cord (testicular artery) is damaged, it will lead to ischemic orchitis or atrophy of the testicle, because the spermatocutaneous artery, which is matched with it, is small and not sufficient to maintain the blood supply needs of the testicle alone. In addition, if the reconstructed internal and external rings in the hernia repair operation are too narrow to compress the testicular cord vessels and the dissected testicular cord is twisted, it can lead to poor blood flow in the testicular cord.

　　(5) Bladder Injury: When the conjoined tendons are sutured to the inguinal ligament or pubic tubercle ligament during the repair operation, there is a possibility of piercing the bladder if the needle is inserted too deeply. If the neck of the hernia sac is dissected too high and exceeds the level of the hernia orifice, it may damage the bladder hidden in the preperitoneal fat. If the bladder, as part of the sliding hernia, is not identified, it can also be damaged during the dissection of the hernia sac. Bladder injury is more likely to occur when the bladder is full.

　　(6) Vascular Injury: There are some large blood vessels passing through the inguinal region, which can be damaged due to rough handling, needle piercing, and suture tearing, and the vessels with atherosclerosis have a higher chance of being damaged. The operation in the inguinal ring area (such as relief of incarceration, reduction of the inguinal ring, repair of the transversalis fascia, etc.) can damage the inferior epigastric artery; when exposing the pubic tubercle ligament and performing McVay-type repair, the femoral vein can be damaged; during the repair surgery using the inguinal ligament, deep needle insertion during suture can damage the external iliac artery or femoral artery. When these blood vessels are damaged, bleeding is often very profuse, and it is difficult to stop the bleeding by compression, and it requires sufficient exposure and ligation or repair.

　　(7) Laparoscopic Port Hernia: With the advent of laparoscopic hernia repair surgery, in recent years, there have been some reports of abdominal wall hernias at the laparoscopic entry sites. In fact, this is a type of incisional hernia, often manifested as an interstitial hernia. Because the hernia orifice is not large, this hernia may become incarcerated. To avoid its occurrence, the orifice should be sutured after the laparoscope is removed.

　　Second, Prognosis

　　Most patients recover well after surgery, but there is a recurrence rate of 4% to 10%.