Incisional hernias of the abdominal wall are not hernias based on the presence of inherently weak anatomical structures, and they are often more diverse and complex than we can imagine. In clinical practice we can find thousands of inguinal hernias that are structurally very similar or similar, but it is rare to encounter two structurally identical incisional hernias. The fact that each patient with an incisional hernia has a different primary pathology, the original surgical management by the surgeon, and the differences in the healing process of the patient’s incision, result in a wide variety of incisional hernias and often a world of difference in the ease of their surgery. It is for this reason that we need to treat each case of incisional hernia carefully. Today, we will discuss the diagnosis and treatment of incisional hernia in the hope of arousing the attention and thinking of the majority of practitioners. Although the etiology of incisional hernia of the abdominal wall is complex and diverse, some factors cannot be changed by the surgeon, such as advanced age, weight, nutritional status, changes in abdominal pressure, etc. The essence of incisional hernia is still a medical disease. The essence of incisional hernia is still a disease of medical origin. In other words, if a patient does not have surgery, he or she will not develop an incisional hernia. What we can do as practitioners, as physicians, is: the choice of incision, the suturing of the incision to close the technical and operative details, which are also closely related to the occurrence of incisional hernia. Admittedly, we still lack relevant clinical evidence to prove which incision closure suture technique is superior, and there are even doubts whether the reduction suture of the abdominal wall can prevent the occurrence of incisional hernia, but we clearly know that the occurrence of incisional hernia is closely related to the infection and fat liquefaction of the incision, therefore, it is more important to emphasize the protection of the abdominal incision during surgery, the concept of asepsis, the importance of cleaning the incision that may have contamination, and Replacement of gloves and instruments focus on specific operational details such as materials used during suturing. II. Diagnosis and classification of incisional hernia – complexity and diversity As far as diagnosis is concerned, the vast majority of incisional hernias are diseases that can be both seen and felt, and there is no difficulty in diagnosing incisional hernias. However, the diagnostic classification of incisional hernia has not yet obtained a unified consensus and index worldwide. If the diagnosis is simply written as “incisional hernia”, it often does not reflect the nature and objective status of these diseases. As stated at the beginning of this article, incisional hernia is not a hernia based on an inherent weakness in the abdominal wall anatomy. The complexity and diversity of incisional hernias is greater than we can imagine. The complexity and diversity of incisional hernias often lie in the fact that patients with incisional hernias have undergone one or more abdominal surgeries, and previous surgeries or complications resulting from surgeries, such as intra-abdominal infections, anastomotic fistulas, etc., can add to the complexity of repairing incisional hernias, especially in patients with malignant gastrointestinal tumors who should also be aware of the current stability of the patient’s disease and the presence of recurrence or metastasis. Therefore, we need to consider the following three aspects in the diagnosis of incisional hernia: 1) Classification according to the size of the abdominal wall defect: i.e. (a) small incisional hernia: maximum diameter of the hernia ring <4 cm; (b) medium incisional hernia: 8 cm="">12 cm, or the ratio of the hernia sac volume to the abdominal cavity volume >15% (regardless of the maximum diameter of its hernia ring). 2) Classification according to the location of the hernia defect: namely (a) incisional hernia in the central region of the anterior abdominal wall (at or near the midline) (including supra- and infra-umbilical incisional hernia, and transverse (up and down incisional hernia around the umbilicus). (b) Incisional hernia in the marginal region of the anterior abdominal wall (subxiphoid, suprapubic, subcostal and proximal inguinal area incisional hernias, etc.). (c) Lateral abdominal wall and back (intercostal iliac and lumbar incisional hernias). 3) Classification based on whether it is a recurrent hernia or not: that is, it is divided into primary incisional hernia and recurrent incisional hernia. Therefore, to make a correct and complete diagnosis of incisional hernia, it is necessary to include a clear description of the above-mentioned classification aspects. Unlike inguinal hernia, surgical treatment of incisional hernia does not emphasize the principle of “tension-free”. This is because there is always some tension in the abdominal wall itself to maintain its approximately barrel-like shape. What should be emphasized are the two most basic goals of incisional hernia repair surgery, namely, to surgically re-establish the integrity of the abdominal wall and to restore the functionality of the abdominal wall. The so-called “integrity” here means the surgical elimination of the hernia sign and the absence of a “second abdominal cavity”. The so-called “functionality” means that the abdominal wall can still maintain its original functions after surgery, such as extension, contraction, and synergistic regulation of important physiological functions such as respiration, circulation, and defecation. The abdominal wall does not become a “solid piece” after the repair, which makes the contraction and extension of the abdominal wall difficult. In order to achieve and realize these two basic objectives, surgeons should pay special attention to the following two aspects when dealing with large incisional hernias and giant incisional hernias: 1) focus on suturing the fascial tissue of the repaired muscles and avoid “bridging” the abdominal wall defect with only one layer of patch. Only by repairing the fascial tissue of the abdominal wall muscles can the integrity and functionality of the abdominal wall be reestablished. The use of componentseparationtechnique (CST) is a technique to be advocated in cases where suture repair of the fascial tissue of the muscle is difficult, because the CST approach allows both the volume of the abdominal cavity to be expanded and the abdominal wall defect to be re-protected by the muscle. (2) The choice of repair material should take into account the “compliance” of the postoperative abdominal wall, especially for large incisional hernias, by choosing a “lightweight”, “large mesh” patch, or a fully absorbable biopatch. The author is not convinced that the biologic patches that are still in use should be used. The author has always had doubts about the efficacy of the “thick”, large composite non-absorbable patches still in use (e.g., PP plus ePTFE) and firmly believes that they will eventually be retired from history because such “thick” materials have no doubt about the integrity of the abdominal wall. The integrity of the abdominal wall is not in doubt, but the function of the abdominal wall is affected by the scarring and “stiffening” of the patch after surgery, which can even lead to some insurmountable symptoms. With regard to the Chinese name of “Lossofabdominaldomin”, “giant incisional hernia with abdominal wall insufficiency “It is important to remind the surgeon that in this condition, the surgery of a patient with a giant incisional hernia is very risky and can be life-threatening if not handled properly, therefore, it is necessary to be fully aware and to make the necessary preoperative preparations. We know that the normal function of the abdominal wall is maintained by 4 pairs of muscles (rectus abdominis, external oblique abdominis, internal oblique abdominis and transversus abdominis) together with the diaphragm, and that thoracic and abdominal pressures interact and coordinate, participating and regulating important physiological processes such as respiration and iatrogenic blood flow. When there is a defect in the abdominal wall (incisional hernia), the defective part of the abdominal wall loses the control and restraint of the abdominal muscles and the diaphragm. In the case of a small incisional hernia, the defect in the abdominal wall is compensated by the remaining abdominal muscles and the diaphragm. However, the incisional hernia (hernia sac volume) gradually increases with the duration of the disease under the continuous action of thoracic and abdominal pressure. If not treated and controlled, it can eventually be lost. The ratio of the hernia sac volume to the abdominal cavity volume can be used clinically to measure the disease state of an incisional hernia, and when the ratio exceeds a certain value (>15%-20%), it can pose a threat to the respiratory and circulatory systems of the body. This state is called “massive incisional hernia with loss of abdominal wall function”, when the patient may have two main physiological changes: (1) respiratory and circulatory system, due to the huge abdominal wall defect, both the abdominal muscles and the diaphragm are restricted during respiration. The huge protrusion of the abdomen causes the diaphragm to shift downward, the abdominal viscera to shift outward, the intrathoracic pressure to decrease, the lung volume to decrease, and the return blood volume to decrease, further reducing the cardiopulmonary function and reserve function. 2) The abdominal organs are mainly cavernous organs, especially the intestines and bladder. The herniation and displacement of the internal organs and the reduction of abdominal pressure tend to dilate the cavernous organs and affect their blood circulation and their own peristalsis, which, together with the restricted function of the abdominal muscles, often cause difficulty in defecation and urination. Therefore, when dealing with such patients, due to the large number of intestinal tubes, omentum and other intra-abdominal organs herniated out of the abdominal cavity for a long time (not restrained by the abdominal muscles and diaphragm), the patient’s diaphragm shifts down, the patient’s hernia sac is huge, and the volume of the abdominal cavity is relatively reduced. If the patient’s diaphragm is simply retracted into the abdominal cavity during surgery, it may cause a rapid rise in intra-abdominal pressure, a decrease in lung volume, a decrease in cardiac return blood volume, and a decrease in renal blood flow, posing a threat to the respiratory and circulatory systems of the organism and subsequently producing inter-abdominal compartment syndrome and endangering the patient’s life. Therefore, for giant incisional hernia, it requires not only a certain level of clinical experience of the operator, but also a certain level of relevant hospital departments such as ICU, which is the only way to effectively ensure the life safety of the patient. Giant incisional hernia often means challenging for the surgeon, but challenging if not handled well the outcome is catastrophic for the patient and requires the practitioner to act with caution.