The Surgical Hernia and Abdominal Wall Surgery Group of the Chinese Medical Association (CMA) prepared and revised the Surgical Treatment Protocol for Adult Inguinal Hernia and Femoral Hernia (hereinafter referred to as “the Protocol”) in 2001 and 2003 respectively, which played an important role in promoting the development of hernia and abdominal wall surgery in China. In recent years, with the advancement of surgical techniques, material science and evidence-based medical research, the clinical evidence of hernia and abdominal wall surgery has been accumulating, and there is now a consensus on the principles and methods of diagnosis and treatment. For this reason, the Hernia and Abdominal Wall Surgery Group of the Chinese Society of Medical Surgeons held repeated discussions on the above “protocol” in 2011, and completed a comprehensive revision in May 2012, and renamed it as “Guidelines for the Treatment of Inguinal Hernia in Adults”. It is now published as follows.
1. Definition
An inguinal hernia is an extra-abdominal hernia that occurs in the inguinal region, i.e., a hernia sac structure exists in the inguinal region that protrudes toward the body surface, and organs or tissues in the abdominal cavity can enter the sac through congenital or acquired abdominal wall defects. A typical inguinal hernia has a hernia ring, hernia sac, hernia contents and hernia cover. According to the anatomical concept of “musculo-pubic foramen”, inguinal hernia includes hiatal hernia, straight hernia, femoral hernia and the rare anterior and lateral femoral vascular hernia.
2. Etiology and pathophysiology of inguinal hernia
(1) Etiology
This is a congenital factor for the development of inguinal hernia.
② Intra-abdominal pressure changes: intra-abdominal pressure and instantaneous intra-abdominal pressure changes are the driving force for the occurrence of extra-abdominal hernias.
③ Weakness of the abdominal wall: various causes of weakness of the abdominal wall due to changes in tissue collagen metabolism and composition, such as changes in tissue collagen composition and atrophy of abdominal wall muscles in the elderly, are associated with the development of inguinal hernia.
④Other: genetic factors, smoking, obesity, and low incision in the lower abdomen may be related to the occurrence of hernia.
(2) Pathophysiology
When organs or tissues in the abdominal cavity enter the hernia sac, the presence of the hernia ring can compress the hernia contents and form an incarcerated hernia. In case of intestine, it can cause mechanical obstruction of the intestine and produce a series of clinical manifestations and pathophysiological changes. With the prolongation of the compression time, edema, exudation and blood flow disorders of the intestine may occur, which may lead to necrosis and perforation of the hernia contents, serious peritonitis and even endanger the patient’s life if not treated in time.
3. Classification and typing of inguinal hernia
The purpose of classification and typing of hernia is to accurately describe the condition, select the appropriate treatment and compare and evaluate the effects of various treatment methods.
Classification according to the anatomical location of the hernia
Inguinal hernia can be classified into hiatal hernia, straight hernia, femoral hernia, compound hernia, etc. (this is the most common clinical classification).
(1) Hiatal hernia: a hernia that enters the inguinal canal from the internal ring.
(2) Direct hernia: hernia that protrudes from the triangle of direct hernia.
(3) Femoral hernia: a hernia that enters the femoral canal through the femoral ring.
(4) Compound hernia: hernia with two or more of the above types present at the same time.
(5) Perifemoral hernia: A hernia that enters the anterior or lateral aspect of the femoral vessels, which is rare in clinical practice.
The hernias can be classified according to the condition of the hernia contents into the hernia sac.
(1) easily recurring hernia: the hernia often appears during standing activities and can be retracted into the abdominal cavity after lying down at rest or being pushed by hand. (2) Refractory hernia: the hernia cannot be completely retracted, but the hernia contents are not organically pathologically altered. Sliding hernia is a type of refractory hernia, which means that the abdominal viscera (such as cecum, sigmoid colon, bladder, etc.) form part of the hernia sac.
(3) Incarcerated hernia: the hernia contents are compressed at the hernia ring and cannot be returned, but blood flow disorders have not yet occurred. (4) Strangulated hernia: the continuation of the course of an incarcerated hernia, the hernia contents become obstructed in blood flow and if not treated in time, serious complications may occur, even life-threatening due to intestinal perforation and peritonitis.
Special type of hernia
Due to the relatively special contents entering the hernia sac, they have a certain impact on the development and treatment of the disease, including
(1) Richter hernia. (1) Richter’s hernia, in which the contents are only part of the intestinal wall and the clinical manifestations may be without complete intestinal obstruction, despite the presence of impaction or strangulation.
(2) Littre’s hernia. The contents of an incarcerated hernia are diverticula of the small intestine (usually Meckel’s diverticula). These hernias are also prone to strangulation.
(3) Maydl hernia. Two or more intestinal collaterals enter the hernia sac and the intervening collaterals remain in the abdominal cavity in the shape of a “W”. The blood flow of the collaterals located in the hernia sac may be normal, but the intra-abdominal collaterals may be necrotic and require a complete examination.
(4) Amyand’s hernia. The content of the hernia is the appendix, and the repair is affected by infection and abscess of the appendix.
Classification
To date, there are more than 10 types of inguinal hernia typologies at home and abroad, which mainly describe the status of abdominal wall defects with anthropogenic factors, and the ones that are still in use are CHARTS, Nyhus, Bendavid, Stoppa, EHS and the Hernia and Abdominal Wall Surgery Group of the Chinese Society of Medical Surgery (2003), but none of them is widely accepted and However, none of them is widely accepted and used, and none of them is supported by sufficient evidence-based medical evidence. At present, the Hernia and Abdominal Wall Surgery Group of the Chinese Society for Surgery has not reached a complete consensus on the staging of inguinal hernia. Therefore, there is no particular recommendation on which typing method to use.
4. Diagnosis and differential diagnosis
The diagnosis of a typical inguinal hernia can be determined on the basis of history, symptoms (the presence of a reversible mass in the inguinal region, i.e., it appears on standing and retracts or disappears after lying down) and physical examination. When the diagnosis is unclear or difficult, imaging examinations such as ultrasound, MRI or CT can be used to assist in the diagnosis. A definitive diagnosis of inguinal hernia can be obtained with imaging techniques of hernia sac reconstruction.
Diseases that need to be identified in the presence of a mass in the inguinal region include enlarged lymph nodes, aneurysms, varicose veins (saphenous veins), soft tissue tumors, abscesses, ectopic testes, and endometriosis.
Diseases to be identified when there is local pain and discomfort in the groin area include adductor tendinitis, pubic osteochondritis, hip osteoarthritis, iliopsoas bursitis, radiation lumbago, endometriosis, etc.
5.Treatment
In adults, inguinal hernia is not likely to heal on its own once it is formed. Non-surgical methods such as local injection lack both theoretical basis and clinical evidence to support them, and surgery remains the only means and method of cure at present.
Asymptomatic inguinal hernia
can be followed up and observed. However, if the hernia is a femoral hernia (with a higher chance of entrapment and strangulation) or if the hernia sac is recently found to be enlarged, surgery should be performed promptly. For those who cannot tolerate surgery due to old age and frailty, conservative treatment with a hernia brace can be chosen.
Symptomatic inguinal hernias should be operated on electively.
Emergency surgery should be performed for incarcerated and strangulated hernias. Tension-free hernia repair is currently the mainstay of surgical treatment. Evidence-based studies have shown that tension-free hernia repair reduces postoperative pain, shortens recovery time, and decreases hernia recurrence rates. Patch insertion requires strict aseptic principles. The use of patches in emergency surgery for incarcerated hernias is still controversial, and repair of contaminated surgical wounds with patches that cannot be absorbed by the body is not advisable.
Surgical treatment of recurrent hernia
Avoidance of anatomic ambiguity and increased surgical difficulty caused by previous surgical trauma is a priority in the surgical treatment of recurrent hernias. If the previous surgery was a conventional open surgery, the recurrence is repaired with a posterior approach or laparoscopic surgery. In addition, the operator’s experience is another factor to be considered in the choice of recurrent hernia treatment modality.
Surgical approach
The surgical approach to inguinal hernia can be divided into the following categories according to the principle of surgery and the level of repair.
Classical suture repair to strengthen the posterior inguinal wall, such as Bassini, Shouldice, etc. Tension-free hernia repairs that strengthen the posterior inguinal wall, such as simple flat-piece repairs (Lichtenstein, Trabucco, etc.) and mesh plug plus flat-piece repairs (Rutkow, Millikan, etc.).
Tension-free hernia repair of the anterior peritoneal space such as Kugel, Gilbert, Stoppa, etc. Laparoscopic inguinal hernia repair
(1) Transperitoneal extraperitoneal pathway repair (TEP).
(2) Transperitoneal preperitoneal repair (TAPP).
(3) Intraperitoneal patch repair (IPOM)
Perioperative management
(1) In addition to the routine preoperative examination, preoperative cardiac, pulmonary and renal functions and blood glucose levels need to be understood and checked in elderly patients.
(2) Geriatric patients with chronic medical diseases should be evaluated for risk before surgery, especially for those with respiratory and circulatory diseases, which require relevant treatment and management before surgery.
(3) Those with factors causing increased intra-abdominal pressure, such as severe ascites, prostatic hypertrophy, constipation and chronic cough, should be given aggressive medical management before surgery to obtain symptomatic relief and improvement.
(4) If the hernia defect is huge and the medical condition is unstable, it is advisable to postpone the surgical treatment.
Use of antibiotics
The prophylactic use of antibiotics for routine inguinal hernia surgery is currently controversial. Evidence suggests that prophylactic antibiotics in high-risk groups may reduce the rate of infection. Risk factors for the presence of infection include advanced age, diabetes, obesity, chronic respiratory infections, multiple recurrent hernias, post-chemotherapy or radiation therapy and other causes that can lead to immunocompromise. The timing of prophylactic antibiotic application should be started intravenously 30 to 45 min before skin incision.
Early complications
include surgical site hematoma and seroma, scrotal hematoma, scrotal effusion, bladder injury, vas deferens injury, urinary retention, early wound pain, and incisional infection.
Late complications
include chronic pain, spermatic cord and testicular complications (ischemic orchitis, testicular atrophy, etc.), late deep patch infections, etc.
Recurrence
Recurrence is still possible with the various surgical methods currently available to treat inguinal hernias, with an overall surgical recurrence rate of about 1 to 3 %. The causes of hernia recurrence can be summarized as both patient’s own factors and surgical operation: improper surgical operation (e.g. patch displacement); patient’s collagen metabolism disorder, chronic metabolic diseases and increased abdominal pressure are all factors contributing to postoperative recurrence.