The Hernia and Abdominal Wall Surgery Committee of the Chinese Physicians’ Association of Surgeons jointly developed the “Hernia and Abdominal Wall Surgery Group of the Chinese Medical Association of Surgery” and the “Hernia and Abdominal Wall Surgery Committee of the Chinese Physicians’ Association of Surgeons”, which have different affiliations but the same goal The two groups are committed to improving the level of hernia and abdominal wall surgery in China. To this end, they collaborated with each other and started the preparation in 2013 and organized the revision and joint discussion at the beginning of this year to finalize the Guidelines for the Treatment of Inguinal Hernia in Adults (2014 Edition). (hereinafter referred to as the “Guidelines”). It should be noted that the predecessor of the “Guidelines” was the “Guidelines for the Treatment of Inguinal Hernia in Adults (2012 Edition)”[1]. The purpose of this revision is to emphasize the specialization and standardization of inguinal hernia surgical treatment and to improve the treatment level of hernia surgery in China.
I. Definition
An inguinal hernia is an extra-abdominal hernia that occurs in the inguinal region, i.e., there is a defect in the abdominal wall in the inguinal region with a hernial sac structure protruding to the body surface, and organs or tissues in the abdominal cavity can enter the hernial sac through the congenital or acquired formed 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.
Etiology and pathophysiology
1. Etiology
(1) Insufficiency of the sphincter is a congenital factor in the development of inguinal hernia.
(2) Intra-abdominal pressure and instantaneous intra-abdominal pressure changes are the driving force for the production of extra-abdominal hernias.
(3) Local weakness of the abdominal wall caused by various alterations in the collagen metabolism or composition of the tissues of the abdominal wall in the inguinal region is associated with the development of inguinal hernias.
(4) Other genetic factors, long-term smoking, obesity, and low incision in the lower abdomen may be associated with the development 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. In case of intestinal canal, it can cause mechanical obstruction of the intestinal canal and produce a series of clinical manifestations and pathophysiological changes. With the prolongation of the compression time, edema and exudation of the intestinal canal and blood flow obstruction of the embedded intestine will occur.
Classification and typing
The purpose of classification and typing of inguinal hernia is threefold: to accurately describe the condition; to select an appropriate treatment plan; and to compare and evaluate the effectiveness of different treatment methods. To compare and evaluate the therapeutic effect of different methods.
1. Classification
(1) According to the anatomical site of hernia, inguinal hernia can be divided into hiatal hernia, straight hernia, femoral hernia, compound hernia, etc.
(1) Oblique hernia: hernia from the internal ring into the inguinal canal.
(2) Direct hernia: hernia protruding from the triangle of direct hernia.
③ Femoral hernia: hernia that enters 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: hernia located in front or outside of the femoral vessels, which is rare in clinical practice.
(2) According to the condition of hernia contents into the hernia sac, it can be divided into
(1) Easily reversible 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., appendix).
(iii) Incarcerated hernia: the hernia contents are compressed at the hernia ring and cannot be retracted; some clinical symptoms (e.g., 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 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.
(3) Special types of hernias have an impact on the development and treatment of the disease because of the relatively special contents entering the hernia sac.
Treatment has certain implications, including
(1) Richter hernia: the embedded contents are only part of the intestinal wall, and even though there is an impaction or strangulation, there may be no clinical manifestation of intestinal obstruction.
② Littre’s hernia: the embedded hernia contents are diverticula of the small intestine (usually Meckel’s diverticula). These hernias are also prone to strangulation.
Maydl hernia: a retrograde incarcerated hernia in which 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 collaterals located in the hernia sac may have normal blood flow, but the intra-abdominal collaterals may be necrotic and require a thorough examination.
Amyand’s hernia [2]: the content of the hernia is the appendix, which can be complicated by inflammation, necrosis and septicemia that can affect the repair.
2. Staging is a more detailed division of hernia conditions based on the classification of hernia. There are more than 10 types of inguinal hernia staging at home and abroad, but there is still a lack of clinical evidence on whether the criteria are appropriate. Therefore, the existing typing system is still imperfect and somewhat subjective. At this stage, CHARTS, Nyhus, Bendavid, Stoppa, EHS and other typing systems are still in use [3, 4], and it is considered in this revision that: the existing typing systems can be referred to, but not recommended as a standard.
IV. Diagnosis and differential diagnosis
1. Diagnosis
The diagnosis of a typical inguinal hernia can be established based on history, symptoms and physical examination [5, 6]. If the diagnosis is unclear or difficult, B-mode ultrasound, MRI/CT and other imaging examinations 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 [7].
2. Differential diagnosis is recommended when the diagnosis of inguinal hernia is made, and differential diagnosis should also be routinely performed and considered comprehensively to prevent the occurrence of hernia surgery on non-herniated patients [8].
(1) Differential diseases that need to be identified in the presence of a mass in the inguinal region include: enlarged lymph nodes, arteriovenous (static)
aneurysms, soft tissue tumors, abscesses, ectopic testes, garden ligament cysts, endometriosis, etc.
(2) Diseases that need to be differentiated when there is local pain and discomfort include: adductor tendinitis, pubic
osteochondritis, hip osteoarthritis, iliopubic bursitis, radiation lumbago, endometriosis, etc.
V. Treatment
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 side effects to patients and should be discarded. In terms of surgical modalities and methods, surgeons should choose according to the patient’s condition and their own skills.
1, treatment principles and surgical indications
(1) Asymptomatic inguinal hernia can be observed on a follow-up basis or treated with elective surgery based on evidence from evidence-based medicine [9, 10]. In the case of femoral hernia (prompt surgical treatment is recommended for those with a higher chance of incarcerated or strangulated hernia or those with a recently detected enlarged hernia sac). For those who cannot tolerate surgery due to old age and frailty, conservative treatment with a hernia support is also an option.
(2) Symptomatic inguinal hernia should be operated electively.
(3) Emergency surgery should be performed for incarcerated and strangulated hernias.
(4) Surgical treatment of recurrent hernias to avoid the anatomical difficulties caused by the trauma of the previous surgery is an option to be considered. (If the previous surgery was a conventional open surgery and the recurrence is repaired by posterior entry or laparoscopic surgery). In addition, the qualification and experience of the surgeon is another factor to be considered in the choice of recurrent hernia treatment.
2. Contraindications and precautions for surgery
(1) Non-emergency inguinal hernia is an aseptic procedure; therefore, the presence of infected lesions in the operative 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 medicine and intensive care are invited to participate and develop surgical plans to prevent the occurrence of abdominal compartment syndrome (ACS).
(4) Surgical risk assessment, using the American Society of Anesthesiologists (ASA) surgical risk assessment criteria is recommended.
3. Surgeon qualifications and training
(1) Routine inguinal hernia repair is not a “simple minor surgery” and the surgeon’s qualifications include licensure, residency and appropriate surgical training.
(2) Physicians who perform lumpectomy hernia repair need to complete and pass the appropriate lumpectomy skills training in addition to the above, and pass the examination.
(3) Training for hernia and abdominal wall surgeons is completed at a training center with appropriate qualifications (according to the relevant regulations of the medical society or physician association).
(4) Tension-free hernia repair using repair materials is currently the mainstay of surgical treatment for inguinal hernia repair. Evidence-based medicine shows that surgery using repair materials reduces postoperative pain, shortens recovery time, and decreases the rate of hernia recurrence [12, 13]
(1) Hernia repair materials are classified as absorbable, partially absorbable and non-absorbable materials.
(2) The implantation of repair materials requires strict implementation of the principle of asepsis. In emergency surgery for incarcerated hernia, the use of materials is not recommended.
The use of non-absorbable materials is not recommended for repairing 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 surgery using hernia repair materials. Tension-free hernia repairs include those that strengthen the posterior inguinal wall: e.g., simple flat patch repair (Lichtenstein, Trabucco, etc.) and mesh-flat patch 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, Gilbert, Stoppa, etc. (For details, please refer to the Appendix)
(2) Laparoscopic inguinal hernia repair is divided into the following three categories according to the surgical route and principles (see the Annex for details)
(1) Repair by the extraperitoneal route (TEP), which has the advantage of less interference with intra-abdominal organs because it does not enter the peritoneal cavity. [14, 15].
② Transperitoneal preperitoneal repair (TAPP) is more likely to detect bilateral hernias, compound hernias and occult hernias because it enters the peritoneal cavity. It also facilitates observation and management of cases of incarcerated hernia and hernia contents that cannot be easily returned. [14, 15].
(iii) Intraperitoneal patch repair (IPOM) is used as the above two methods when there are difficulties in their implementation and is not recommended as the preferred method for lumpectomy for the time being [16]. When repairing by this method, the repair material must be used with an anti-adhesive effect.
6. Perioperative treatment
(1) General treatment
(1) In addition to the routine preoperative examination, heart, lung and kidney function and blood glucose level should be checked in elderly patients.
② Elderly patients with chronic medical diseases should be evaluated for risk before surgery, especially for patients with respiratory and circulatory system diseases, which should be treated and managed before surgery.
(2) About the use of antibiotics
It is debated whether inguinal hernia surgery is routinely performed with prophylactic antimicrobials [17]. There is evidence that prophylactic application of antibiotics to high-risk groups may reduce the chance of infection [18].
(i) High-risk factors include advanced age, diabetes, obesity, wasting, multiple recurrent hernias, post-chemotherapy or radiotherapy and other immunocompromised conditions.
(ii) The timing of prophylactic antibiotic application is recommended to start intravenous administration 30 min to 1hr before skin incision.
7.Complications
(1) Early complications include 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.), late patch infection, patch displacement, etc.
(3) Recurrence There is still a possibility of recurrence 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 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 abdominal pressure are also factors of recurrence.