1.Basic causes of inguinal hernia
The basic causes of inguinal hernia occurrence include two major factors, congenital and acquired. Congenital factors include.
(1) unclosed or incomplete atresia of the sphincter formed by the peritoneum descending with the testis;
(2) Structural defects of the spermatic cord or round ligament through the internal ring;
(3) Weakness of the closed structure of the triangle of direct hernia of the muscopubic foramen.
Acquired factors are.
(1) uprightness in humans, resulting in higher pressure bearing in the inguinal region ;
(2) degenerative changes in the histological structure of the inguinal region, resulting in decreased pressure-bearing capacity. This is particularly evident in straight hernias, the proportion of which in inguinal hernias increases with age. Due to the different causes, inguinal hernias differ in their age presentation, with childhood hernias being more often associated with unclosed or incomplete atresia of the peritoneal sheath and those occurring in young adulthood being more often associated with structural defects of the internal ring.
True adult hernias generally tend to occur after 30 years of age, often with structural defects coexisting with degenerative changes in the closure structure, and in older adults, with degenerative changes in the closure structure of the musculo-pubic foramen. Corresponding to the strategy of surgical treatment, the surgical strategy should be different in different age groups.
2. Different principles and history of hernia repair
In 40 AD, Celsus used inguinal canal incision to allow inflammation and scar healing, and later even burned the wound with a soldering iron to form more scar to treat inguinal hernia, showing the initial concept of hernia surgical treatment, which is considered the beginning of hernia treatment. 16~19th century modern anatomical theory was gradually established, and by the mid-19th century modern anesthesia appeared and was clinically applied These advances cleared the anatomical and pain barriers for the development of surgery.
In 1877, Vincinz Czerny first described the steps of hernia surgery: ligation of the external ring, removal of the hernia sac and reduction of the internal ring. 1887, Bassini reported his classical hernia repair, which consisted of high ligation of the hernia sac, freeing and displacing the spermatic cord, incision of the transverse abdominal fascia, repair of the internal ring and strengthening of the posterior wall of the inguinal canal to eliminate the hernia gap by suturing the bowed margin to the inguinal ligament. The hernia gap was eliminated by suturing the bowed edge to the inguinal ligament.
Considering that the average life expectancy of the European population in the mid-19th century was only in the 40s and pediatric surgery was not widespread, most inguinal hernias in the Bassini era were congenital hiatal hernias that were not treated in childhood and continued into adulthood, i.e., predominantly hiatal hernias. The pathologic anatomy of the hernia is mainly an abnormal channel formed by the unclosed sphincter, with changes in the internal ring and transversus abdominis fascia as a subsequent secondary change and relatively less pronounced degeneration of the transversus abdominis fascia.
With the understanding of the disease characteristics at that time, the closure of the herniated channel should be a reasonable choice of approach. Since then, as the average human lifespan has increased and pediatric hernias have been treated promptly, adult hernias with degenerative tissue changes in the inguinal region have gradually become the mainstream in clinical practice. In addition, due to errors in the initial dissemination of the Bassini procedure, followed by a supposedly high postoperative recurrence rate or other deficiencies, more than 200 modified surgical approaches have emerged since the early 20th century.
Some of the more influential ones are the Halsted procedure (1889), the Furguson anterior wall repair (1890), and McVay (1948), who proposed a procedure in which the united tendons and transverse abdominal fascia were sutured to the pubic commissure ligament, as well as hernioplasty. In addition, the Shouldice procedure utilizes overlapping sutures of the transversus abdominis fascia to achieve a minimal tension repair to distinguish it from other classical tension repairs. However, none of these procedures is characterized by an effective and firm closure of the hernia orifice, emphasizing the use of thick nonabsorbable threads or even wires.
Surgical approaches characterized by closure of the hernia orifice suffer from the following shortcomings.
(1) Forced pulling together of the adjacent tissues with existing defects, high suture tension and long postoperative recovery time;
(2) Mutual incompatibility of non-identical tissues after forced suturing, which does not easily produce true healing;
(3) Recurrence rate is as high as 10%-20%, with higher recurrence rate in elderly patients;
(4) Except for the Shouldice procedure, for true adult hernias, the design of the procedure is generally poorly recognized for degenerative changes in the transversal abdominal fascia.
Repair and reconstruction of the internal ring and/or transverse abdominal fascia – tension-free hernia repair has improved dramatically in the 20th century, with effective early management of childhood hernias and a significant decrease in the number of hernia continuations from childhood to adult hernia. At the same time, because the average life expectancy of human beings has greatly increased, adult hernias with degenerative tissue changes in the inguinal region as the main cause have become mainstream, and the prevention of recurrence has become a major concern for surgeons when treating the repair.
Since the middle of the last century, many scholars have tried to perform hernia repair with artificial materials, but they all ended up in failure due to serious defects such as poor patch compatibility and susceptibility to infection. in 1969, Usher first reported the use of Marlex polypropylene patch reinforcement on top of traditional hernia repair, which is actually a hernioplasty. in 1989, Lichtenstein [2] reported In 1989, Lichtenstein [2] reported the Marlex patch repair of the posterior wall of the inguinal canal o introduced the concept of “tension-free repair”, thus bringing hernia repair surgery into the era of tension-free repair using patches.
The tension-free repair differs from previous hernioplasty in that it avoids the closure mechanism of suturing the joint tendon to the inguinal ligament and theoretically focuses on repairing the transverse abdominal fascia lesion by strengthening and replacing the transverse abdominal fascia for therapeutic purposes, which is the core concept of Lichtenstein’s “tension-free” repair concept. Based on this concept, Gilbert and Rutkow refined it and later introduced the three-dimensional mesh hernia repair and the hernia ring-filled repair, respectively.
Currently, the concept and technique of tension-free repair is widely accepted by hernia surgeons, but there are still problems with access injuries and associated complications such as chronic pain, hematoma formation, seroma, skin numbness and scarring tumors, as well as complications related to artificial materials such as foreign body sensation, patch infection, pain and even intestinal fistula. The current consensus is that tension-free hernia repair is not the simple procedure that it is commonly thought to be and that physicians require specialized training, with a surgical training load of 100 or more cases for hernia specialists, based on the experience of various hernia surgery centers.
With the advancement of anatomical understanding, the concept of “myopubic foramen” was introduced. The inner border of the myopubic foramen is the rectus abdominis muscle, the outer border is the iliopsoas muscle, the upper border is the internal oblique muscle and the transversus abdominis muscle, and the lower border is the pubic bone branch and the pubic comb ligament. It is a structurally weak area in the inguinal region.
The congenital structural weakness of this area and the degenerative changes of the transverse abdominal fascia are considered to be the root cause of the hernia. The inguinal hernia is characterized by the fact that no matter how large the hernia sac is, the maximum diameter of the hernia ring usually does not exceed the long diameter of the myopubic foramen, which limits the size of the hernia patch size parameters.
3. Inguinal hernia repair strategies in the elderly
The age limit for the elderly is currently defined as 60 years and older, but 65 years is now more commonly used as the defining criterion for the elderly. Elderly patients can be divided into 3 categories according to their actual age: younger elderly patients aged 65 to 75 years; elderly patients aged 76 to 85 years; and older elderly patients aged 85 years or older. According to statistics, the average life expectancy of the global population in 2015 was 71 years, of which 73 years for women and 68 years for men; the average life expectancy of the Chinese population was 74 years for men and 77 years for women. more than 10% of China’s elderly population was over 65 years old in 2015, and it is expected that the elderly population over 65 years old will be as high as 11.31% by 2020.
There are more than 100 million elderly people over 60 years old in China, and if the prevalence rate of elderly men is estimated at 5%, about 2.5 million elderly inguinal hernia patients need surgical treatment every year, so the volume of treatment is very large, and how to make good overall decisions for elderly hernia is a problem that hernia surgeons cannot ignore.
Elderly inguinal hernia patients generally have the following characteristics.
(1) Almost all hernias are caused by the degeneration of the musculo-pubic foramen closure structure and are often bilateral and coexistent;
(2) A high percentage of co-morbidities, such as coronary heart disease, diabetes mellitus, and chronic obstructive pulmonary disease are common;
(3) oral anticoagulants are often taken;
(4) local progression is faster once the hernia appears, the proportion of huge hernia sacs is higher, and the proportion of postoperative local complications is correspondingly higher in those with huge hernia sacs; therefore, waiting for observation is not the best strategy for elderly hernia, but early surgery should be performed. Inguinal hernias in the elderly should be treated surgically unless there is a clear contraindication to surgery.
Due to the significant structural degeneration of the muscopubic foramen, it is not suitable for traditional Bassini surgery and artificial material repair is the main surgical approach. Generally speaking, posterior laparoscopic surgery can be considered for young and old patients, and anterior local anesthesia surgery is safer for elderly people over 75 years old.
4. Summary and outlook
Reviewing the history of inguinal hernia treatment, its treatment principle has gone through three different stages: “closure of the hernia hole”, “reconstruction and strengthening of the transversus abdominis fascia” and “muscle-pubic foramen closure”. Although they are all effective for inguinal treatment, myopubic foramen sealing is closer to the human abdominal wall structure and conforms to human physiology.
In the future, it is expected that more personalized 3D blocking devices will emerge, allowing for easier operation and thus a shorter learning curve. Improvements in artificial materials will focus on solving the problems of material deformation, contact with internal organs without adhesions and secondary damage, and good fixation to prevent drift, so that the treatment of inguinal hernia will move towards a true era of minimally invasive treatment.