Introductory Chapter: Abdominal Wall Hernias and Prosthetic Material

1. Introduction

It is the displacement and protrusion of the intra-abdominal structure and organs from weak places on the abdominal wall. While there are many varieties, it most often occurs in the inguinal. Umbilical hernias follow. Due to the presence of intestine in the hernia sac, it is important because intestinal obstructions (knotting), fluid-electrolyte incompatibility and death are seen.

Hernias that occur in areas of abdominal surgery called inguinal, umbilical and incisional hernia are anterior abdominal wall hernias. Hiatal hernias, which are called as gastrocoele and cause reflux, are hernias at the junction of the stomach and esophagus.

It is observed in both sexes, but more in men.

As the causes of hernia; Sudden, severe increase in intra-abdominal pressure, infections with lung problems due to smoking, and in cases where chronic intra-abdominal pressure increases by coughing continuously, the anterior abdominal wall weakens and coughing time is prolonged

• Those with chronic obstructive pulmonary disease (COPD)

• In cases of increased intra-abdominal pressure in pregnant women

• In obese people (especially in people who have the weak anterior abdominal wall)

• In kidney patients who are dialyzed their peritoneal

• Abdominal wall hernia may develop in those with collagen vascular disease.

Anterior abdominal wall hernias; consist of a wide range of hernias including incision site, umbilical, epigastric and suprapubic hernias. Morbid obesity, accompanying diseases, immunosuppression and prostate diseases accompanied by urination disorders are known important factors in the formation of incisional hernias (IH). Although the first 5 years after surgery is the most critical time for the development of IHs, it can also develop later on [1]. After minimal invasive treatments commonly come into use, shorter hospital stays, reductions in wound site infections and recurrence rates have led to the increasing frequency of use of these methods [2, 3, 4]. A more comfortable view is provided by the magnification effect of the telescope in addition to the advantages such as laying the graft by seeing the minimal tissue trauma, graft and surrounding healthy tissue in detail in laparoscopic surgery, but experience is required for successful results together with these advantages. In a meta-analysis performed by Castro et al., it was found that laparoscopy reduced the postoperative hospital stay and the infection rate in the perioperative period, but increased the operative time, enterotomy, and postoperative pain [5]. Similarly, it was found that the duration of hospital stay, recurrence, complication and infection rates were lower in the laparoscopic group, but that the operation time was also shorter in the laparoscopic group in the study of Itani et al. [6].

Abdominal wall hernias (inguinal, femoral, umbilical, epigastric and incisional) require emergency surgery with a frequency of 5–13% due to incarceration. Following emergency surgery in incarcerated hernias, the risk of morbidity is still high despite advances in anesthesia, antisepsis, antibiotherapy, and fluid therapy [7, 8]. They reported 2% mortality in elective hernia operations, while this rate was 16% in emergency hernia operations in the research done by Williams and Hale [9]. There are many similar studies in the literature [10, 11].

Spigelian hernia is rarely seen and is also known as lateral ventral hernia. Spigelian hernia is the herniation of the peritoneal sac containing preperitoneal fat, peritoneal sac or rarely visceral from the Spigelian region. The Spigelian region is bounded laterally by the muscular fibers of the internal oblique and medially by the lateral edge of the anterior lamina of the rectus sheath. Spigelian hernia may be congenital or acquired. Although congenital Spigel hernia has been reported, it is mostly considered an acquired hernia. It constitutes 1–2% of all abdominal wall hernias. Incidence of incarceration and strangulation of Spigelian hernia is high [12, 13, 14]. Spigelian hernias are mostly observed in women. It was reported that it was found in women with a rate of 88% in some series [15]. The incidence probability of incarceration and strangulation is high because the neck of the hernia sac is narrow [16]. The need for emergency operation increases up to 20% [17]. Spigelian hernia should be treated surgically because of its high complications [18, 19, 20]. The closure can be done through the primary suture, patch or laparoscope [21].

Obturator hernia comprises for only 0.05–1.4% of all hernias [22]. Women are 6 to 9 times more at risk than men because of the wider pelvis. Conditions that increase intra-abdominal pressure such as advanced age, weight loss, constipation and chronic lung disease or ascites are other risk factors. Diagnosis of obturator hernia is usually difficult. Physical examination, ultrasonography, CT scan, laparoscopy, and laparotomy are useful. Early diagnosis of obturator hernia prevents complications such as strangulation and perforation, and thereby reduces mortality and morbidity. In respect to treatment of obsturator hernia, abdominal, retropubic, obturator, and inguinal surgical approaches have been used in case of non-emergency. However, in case of emergency, the abdominal approach should be preferred to research complications such as strangulation or perforation. The hernia sac should be attached by turning upside down after the sac shrinks. The stump should be repaired with mesh, Teflon, fascial flap, or primary sutures. It may also be covered by a segment of the omentum. For obturator hernia, laparoscopic approaches have also been described in the last 20 years [23, 24].

Supravesical hernias develop at the supravesical fossa between the remnants of the urachus and the left or right umbilical artery. They are often the cause of intestinal obstruction. The supravesical fossa is the abdominal wall area between the remnants of the urachus (median umbilical ligament) and the left or right umbilical artery (medial umbilical ligament) [25, 26]. The remnant of the urachus divides into the right and left fossa. There are two variants of supravesical hernias: an external form caused by the laxity of the vesical preperitoneal tissue, and an internal one with a growing hernia sac from back to front and above the bladder in a sagittal paramedian direction [25, 27]. External supravesical hernia often occurs as a direct inguinal hernia.

Congenital anomalies of the diaphragm are the result of fusion defects of the diaphragm, or these are due to intestinal developmental disorders accompanied with diaphragmatic closure problems. Congenital Diaphragmatic Hernias (CDH) are classified as Bochdalek (posterior-lateral), Morgagni (anterior-retrosternal) and septum transversum defects. Bochdalek Hernia is a congenital diaphragmatic anomaly that occurs in one in 2000–12,500 live births [28]. Surgical treatment of CDH can be performed by laparotomy, thoracotomy, laparoscopy, thoracoscopy and/or a combination of these procedures. Diaphragm defects can be closed with or without a prosthesis. Generally, closure of these defects with primary sutures is usually impossible due to the size of the defect. Various grafts can be used in this kind of hernias. Yet, although polyprolene mesh support provides for tissue growth, it is a theoretically accepted risk for this mesh to erode the gastrointestinal organs. By virtue of less adhesion formation in polytetrafluoroethylene and other dual prostheses, these grafts are more preferred [29].

After coming into use of laparoscopic techniques in general surgery in the 1990s, it has been reported that the first inguinal hernia repair was performed by method of minimal invasive in 1992 [30]. Transabdominally (TAPP) and Total extraperitoneal (TEP) methods are two important laparoscopic repair methods of inguinal hernia. The main difference between the TAPP and TEP method is the access to the preperitoneal space. TEP method is more suitable for patients with intra-abdominal adhesions due to not entering the abdomen [31]. Because of the advantage of abdominal exploration, the TAPP method may be more suitable for laparoscopic repair of strangulated hernias [31]. The learning curve in the TAPP method is shorter than the TEP method [32]. While using the TEP method, in case of technical problems, it may be turned the TAPP method instead of the open method. Success in inguinal hernia repair is associated with long-term recurrence rates, and these rates have been reported in the range of 1–2% for the TEP method and 0–3% for the TAPP method [33, 34]. It is considered that the TEP is more appropriate in patients with intra-abdominal adhesions, and the TAPP method in cases where extensive exploration.

2. Prosthetic material

As well as the surgery, developed by Italian surgeon Eduardo Bassini in the nineteenth century and called own name, opened an era in hernia surgery, the especially long-term results of hernia repairs were not at an acceptable level until the 1990s, when patch repair started to become popular. Likewise in such old methods, the individual’s own tissues were brought closer to each other with suture and a serious distention was formed in the operation area. This distention caused severe pain and discomfort in the early postoperative period, delayed return to normal activities and work, and recurrence of the disease in the long term. In hernia surgeries, the fact that the results of traditional repairs performed by suturing the tissues each other are not sufficient, in other words, the high recurrence rate of hernia has led surgeons to consider different methods over time. Today, the patches used in hernia repairs (mesh) are mostly synthetic materials. In a word, it is a kind of prosthesis made of inorganic materials (prosthetic material).

3. Ideal patch

A patch to be placed on the human body for hernia surgeries should have certain features:

• The patch should be able to be produced in the desired structure, shape and size.

• It should be made from a non-carcinogenic substance that is to say not cause cancer.

• It should not cause allergic and hypersensitivity reactions.

• It should be able to integrate into human tissue, but not cause excessive inflammation and foreign reaction.

• It should have the strength to withstand the mechanical stress due to intra-abdominal pressure and abdominal wall movements.

• It should be chemically inert, that is to say, it should not react with tissue fluids.

• It should be able to sterilize.

Standard polypropylene (plastic) patch still takes the largest share among synthetic patches used in hernia surgeries. The standard polypropylene patch is a “small pore and high weight” prosthetic material. Compound patches are made partly from polypropylene and partly from materials that are absorbed and lost by body fluids over time. The solute may be polyglycolic acid or polyglecapron. Compound patches have sufficient resistance in all cases and can be used safely in the treatment of abdominal wall hernias. These patches find use especially in surgical incision hernias that require large patches.

In patches of dual mesh/composite mesh, the main material is usually polypropylene or sometimes polyester. The interior surface of the patch that will come into touch with the intestines is covered with some non-adhesive materials in order to prevent these risks. Because this process requires special technology, the cost of this kind of patches is high. Such expensive patches must use in the laparoscopic repair of ventral hernias (umbilical, epigastric, incisional, Spigelian). In addition, these patches are also needed for the open repair of hernias in which a part of the abdominal wall is lost or the tissues are impossible being closed up each other.

Biological patches are produced from donor tissue with advanced technology in a laboratory environment. Living tissues used for this purpose today are human, pig and bovine skin, pig small intestine submucosa tissue, bovine and horse pericardium (heart membrane). The grafts (patches) used in this approach, which can be called a kind of graft, are designed to form a suitable basis for later collagen production and storage, as well as they are rich in collagen material that will provide strength.