The Hernia and Abdominal Wall Surgery Group of the Chinese Society of Medical Surgeons and the Hernia and Abdominal Wall Surgery Committee of the Chinese Physicians Association of Surgeons Branch have different affiliations but the same goal, that is, to improve the diagnosis and treatment of hernia and abdominal wall surgery in China.
To this end, the two groups collaborated with each other to prepare and revise the Guidelines for the Treatment of Inguinal Hernia in Adults (2014 Edition) (hereinafter referred to as the “Guidelines”) from 2013 to early 2014.
It should be noted that the predecessor of the “Guidelines” was the “Guidelines for the Treatment of Inguinal Hernia in Adults (2012 Edition)”, and this revision added some articles based on the recent progress of related disciplines at home and abroad and the national conditions in China, with the aim of emphasizing the specialization and standardization of inguinal hernia surgical treatment and improving the treatment water of hernia surgery in China.
1. Definition of inguinal hernia
Inguinal hernia refers to an extra-abdominal hernia occurring in the inguinal region, that is, there is a defect in the abdominal wall in the inguinal region with a hernia sac structure protruding to the body surface, and organs or tissues in the abdominal cavity can enter the hernia sac through the congenital or acquired formation of the abdominal wall defect.
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 hernias include hiatal hernia, straight hernia, femoral hernia and, more rarely, anterior and lateral femoral vascular hernias.
2. Etiology and pathophysiology of inguinal hernia
(1) Etiology
(1) Unclosed sphincter: a congenital factor for the occurrence of inguinal hernia.
(2) Intra-abdominal pressure: intra-abdominal pressure and instantaneous intra-abdominal pressure changes are the driving force for the occurrence of extra-abdominal hernias.
3) Local weakness of the abdominal wall: various causes of weakness of the abdominal wall due to changes in collagen metabolism or composition of the tissues of the abdominal wall in the inguinal region are associated with the development of inguinal hernia.
(4) Others: genetic factors, long-term smoking, obesity, and low incisions in the lower abdomen may be associated with the occurrence of inguinal 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. If the contents are intestinal canal, it can cause mechanical obstruction of the intestinal canal and produce a series of clinical manifestations and pathophysiological changes.
With prolonged compression, edema and exudation of the intestinal canal and blood flow disorders of the embedded intestine may occur, which may lead to necrosis and perforation of the hernia contents and then serious peritonitis and even life-threatening if not treated in time.
(3) Classification and typing of inguinal hernia
The purposes of classification and typing of inguinal hernia include: (1) to accurately describe the condition; (2) to select the appropriate treatment plan; and (3) to compare and evaluate the therapeutic effects of different methods.
1) Classification
Classification according to the anatomical location of the hernia
Inguinal hernia can be classified into hiatal hernia, straight hernia, femoral hernia, compound hernia, etc.
(1) Hiatal hernia: a hernia that enters the inguinal canal from the internal ring.
(2) Direct hernia: hernias that protrude from the triangle of direct hernia.
(3) Femoral hernia: hernia entering the femoral canal through the femoral ring.
(4) Compound hernia: hernia in which two or more of the above types are present at the same time.
(5) Perifemoral hernia: a hernia located in front or outside of the femoral vessels, which is rare in clinical practice.
(2) Classification according to the condition of hernia contents into the hernia sac
(1) Easily recurring hernia: the hernia often appears when standing or moving, and can be retracted into the abdominal cavity after lying down and resting or after pushing by hand.
(2) Refractory hernia: the hernia cannot be completely retracted, but the hernia contents do not undergo organic pathological changes. Sliding hernia is a type of refractory hernia because part of the hernia sac is made up of abdominal viscera (e.g., cecum).
(3) Incarcerated hernia: the hernia contents are compressed at the hernia ring and cannot be retracted; some clinical symptoms (such as abdominal pain and manifestations of gastrointestinal obstruction) may be present but blood flow disorders have not yet occurred.
(4) strangulated hernia: the continuation of the course of incarcerated hernia, the hernia contents have blood flow obstruction, if not treated in time, serious complications may occur, even life-threatening due to intestinal perforation and peritonitis.
(3) Special type of hernia
The contents entering the hernia sac are relatively special and have a certain impact on the development and treatment of the disease, including the following types.
(1) Richter’s hernia: the contents of an incarcerated hernia are only part of the intestinal wall, and there can be no clinical manifestation of intestinal obstruction even though incarceration or strangulation has occurred.
(2) Littre’s hernia: the embedded hernia contents are diverticula of the small intestine (usually Meckel’s diverticula). These hernias are prone to strangulation.
(3) Maydll hernia: a retrograde incarcerated hernia in which two or more intestinal loops enter the hernia sac and the intervening loops remain in the abdominal cavity in the shape of a “W”.
(4) Amyand’s hernia: The content of the hernia is the appendix, which is often complicated by inflammation, necrosis and septicemia and affects the repair.
(4) Typing
Based on the classification of hernia, a more detailed division of hernia conditions is made. There are more than 10 types of inguinal hernia staging at home and abroad, but there is still a lack of clinical evidence as to whether the criteria are appropriate. Therefore, the existing typing system is still imperfect and somewhat subjective.
At the present stage, CHARTS, Nyhus, Bendavid, Stoppa, EHS and other typing systems are still in use. In this revision, it is considered that the existing typing systems can be referred to, but not recommended as the standard.
3. Diagnosis and differential diagnosis of inguinal hernia
(1) Diagnosis
The diagnosis of a typical inguinal hernia can be established based on history, symptoms and physical examination. If the diagnosis is unclear or difficult, imaging such as B-mode ultrasound, MRI and/or CT can be used to help establish the diagnosis. Reconstruction of the hernia sac in imaging can often lead to a definitive diagnosis of inguinal hernia.
(2) Differential diagnosis
It is recommended that when a diagnosis of inguinal hernia is made, a differential diagnosis should also be routinely performed, with comprehensive consideration to prevent the occurrence of hernia surgery in patients with non-hernias.
(1) Differential diseases that need to be identified in the presence of a mass in the inguinal region: including large lymph nodes, arteriovenous (static) aneurysms, soft tissue tumors, abscesses, ectopic testes, round ligament cysts, endometriosis, etc.
(2) Diseases that need to be identified when there are local symptoms of pain and discomfort: including enthesopathy, pubic osteochondritis, hip osteoarthritis, iliopubic bursitis, radiation lumbago, endometriosis, etc.
4.Treatment of inguinal hernia
Almost all inguinal hernias are cured clinically through surgery. There are still certain non-surgical treatments in the domestic medical market, such as “local injection of hernia” and other non-surgical treatments, which are not in line with scientific principles and can bring a series of complications and adverse reactions to patients and should be discarded. In terms of surgical modalities and methods, surgeons should choose according to the patient’s condition and the skills they have acquired.
(1) Principles of treatment and indications for surgery
(1) Asymptomatic inguinal hernia can be observed on a follow-up basis or treated with elective surgery based on evidence from evidence-based medicine. If the hernia is a femoral hernia (prompt surgical treatment is recommended for those who have a higher probability of incarceration and strangulation or those who have recently found significant hernia sac enlargement). For those who cannot tolerate surgery due to old age and frailty, etc., conservative treatment with a hernia support is also available.
2) Elective surgery should be chosen for symptomatic inguinal hernias.
3) Emergency surgery should be performed for incarcerated and strangulated hernias.
4) Surgical treatment of recurrent hernias: avoidance of anatomical difficulties caused by trauma of the previous surgery is an issue to be considered (e.g., if the previous surgery was a conventional open surgery, the recurrence should be repaired by posterior entry or laparoscopic surgery). In addition, the qualification and experience of the physician is also a factor to be considered when choosing a recurrent hernia treatment modality.
(2) Contraindications and precautions for surgery
(1) Non-emergency inguinal hernia is an aseptic procedure; therefore, the presence of infected lesions in the surgical area should be considered a contraindication to surgery.
2) Relative contraindications and precautions: Those with factors causing increased intra-abdominal pressure, such as severe ascites, prostatic hypertrophy, constipation and chronic cough, need to be treated accordingly before surgery to reduce the occurrence of complications such as early postoperative recurrence.
(3) For patients with huge abdominal wall defects and huge hernia cystic cavity, a multidisciplinary treatment model is recommended. Multidisciplinary consultations such as orthopedics, respiratory and intensive care departments are requested to participate and develop the surgical plan to prevent the occurrence of inter-abdominal compartment syndrome.
(4) Surgical risk assessment, the use of the American Society of Anesthesiologists surgical risk assessment criteria is recommended.
(3) Qualification and training of surgeons
(1) Routine inguinal hernia repair is not a “simple minor surgery” and should be performed by surgeons who are licensed to practice medicine and have completed their residency and appropriate surgical training.
(2) Physicians performing lumpectomy hernia repair need to complete and pass the appropriate lumpectomy skills training and examination in addition to the above.
(3) Hernia and abdominal wall surgeon training: completed at a training center with appropriate qualifications (according to the relevant regulations of the Chinese Medical Association or the Chinese Medical Association).
(4) Inguinal hernia repair materials
Tension-free hernia repair using repair materials is currently the main method of surgical treatment. There is medical evidence that surgery using repair materials can reduce postoperative pain, shorten recovery time, and decrease the recurrence rate of hernias.
(1) Hernia repair materials are classified into absorbable, partially absorbable and non-absorbable materials.
(2) The implantation of repair materials requires strict implementation of the principle of asepsis. The use of materials is not recommended for emergency surgery of incarcerated hernia, and the use of non-absorbable materials for repair is not recommended for surgery with the possibility of contamination.
(5) Surgical operation method
Surgical treatment of inguinal hernia can be divided into two categories: conventional surgery and lumpectomy.
(1) Conventional surgery can be further divided into tissue-to-tissue tension suture repair (also called classical surgery), such as Bassini and Shouldice, and tension-free hernia repair using hernia repair materials.
Tension-free hernia repairs include those that strengthen the posterior inguinal wall: e.g., simple flat-piece repair (Lichtenstein, Trabucco, etc.) and mesh-piece repair (e.g., Rutkow, Millikan, etc.), as well as tension-free hernia repairs that target the anterior peritoneal space of the “musculo-pubic foramen”: e.g., Kugel, Grabucco, etc. (2) Laparoscopic inguinal hernia repair: Kugel, Gilbert, Stoppa, etc.
(2) Laparoscopic inguinal hernia repair is divided into the following three categories according to the surgical approach and principles: (1) transperitoneal extraperitoneal approach (TEP), which has the advantage of less disturbance to intra-abdominal organs because it does not enter the abdominal cavity. ② Transperitoneal preperitoneal repair (TAPP), which enters the abdominal cavity and makes it easier to detect bilateral hernias, compound hernias and occult hernias. It also facilitates the observation and management of cases of incarcerated hernia and hernia contents that are not easily retractable.
(3) Intraperitoneal patch repair (IPOM), which is used when the above two methods are difficult, is not recommended as the preferred method for laparoscopic surgery for the time being. When repairing by this method, the repair material should be used with anti-adhesion effect.
(6) Perioperative treatment
(1) General management: (1) In addition to the routine preoperative examination, the heart, lung and kidney functions and blood glucose level should be understood and checked in elderly patients before surgery. ②For elderly patients with chronic medical diseases, their risk should be evaluated before surgery, especially for patients with respiratory and circulatory system diseases, which need to be treated and managed before surgery.
(2) Regarding the use of antibiotics: it is debated whether inguinal hernia surgery is routinely performed with prophylactic antimicrobials. There is evidence that prophylactic application of antibiotics to high-risk groups can reduce the probability of infection.
①High-risk factors: including advanced age, diabetes, obesity, wasting, multiple recurrent hernias, post-chemotherapy or radiotherapy and other immunocompromised conditions.
(2) Timing of prophylactic antibiotic application: It is recommended to start intravenous administration 30min to 1h before skin incision.
(7) Complications
(1) Early complications: including surgical site hematoma and seroma, scrotal hematoma, scrotal effusion, bladder injury, vas deferens injury, urinary retention, early wound pain, incisional infection injury, etc.
2) Late complications: chronic pain, spermatic cord and testicular complications (ischemic orchitis, testicular atrophy, etc.), delayed patch infection, patch displacement, etc.
(3) Recurrence: The various surgical methods currently available to treat inguinal hernias still have the potential for recurrence, with an overall surgical recurrence rate of 1% – 3%.
The causes of hernia recurrence can be summarized into two aspects: surgical operation and patients themselves: incomplete separation of the hernia sac during surgery, improper fixation of the patch, postoperative hematoma and infection are all factors of recurrence; patients with collagen metabolism disorders, chronic metabolic diseases and increased intra-abdominal pressure are also factors of recurrence.
5. Versions and updates
This guideline was completed and published in 2014 and is therefore called the “Practice for the management of inguinal hernia in adults (2014 edition)”. In the future, as medical progress and clinical evidence accumulate and update, we will discuss, revise and update the Guidelines periodically, and the newer version will automatically replace the previous one.