The diagnosis of eventration and abdominal wall hernias is usually clinical, and a physical examination is sufficient in most cases. However, in cases of complicated hernias or atypical locations and in obese patients or in those with a history of previous abdominal surgery, the clinical diagnosis may be difficult.

Imaging techniques effectively establish the diagnosis in these uncertain cases, differentiating other situations that may look like hernias or eventrations, such as asymmetries, muscle atrophy and paralysis, bruising, or tumors of abdominal wall. Also, imaging allows for evaluation of related complications, abdominal volume, and hernia sac volume; helps in terms of assessing the availability of the aponeurotic muscle plane; and assists with choosing the best therapeutic options.

The development of imaging techniques in recent years has allowed us to obtain very precise and quantifiable information regarding hernia orifices, location, content, and muscle condition.

Ultrasound is a technique that has a variable sensitivity and specificity as demonstrated in published series, since it depends upon the skill and experience of the operator and also depends on the physical characteristics of the patient. It is an imaging technique that, due to its noninvasive features, is considered a technique of choice for pediatric patients.

Computerized Tomography (CT) is currently the most widely used technique in the overall assessment of the condition of the abdominal wall. It is an effective technique in the detection of hernias and allows classification with low operator variability. Also, with the current multi-detector equipment, it is an extraordinarily rapid test that can be performed in just a few seconds. Although there are different imaging protocols, it is normally recommended to obtain reconstructed images with a thickness less than 3 mm, which would allow for obtaining high-quality multiplane images (sagittal, coronal, oblique) later.

In studies of abdominal wall with CT, it is not required to systematically use intravenous contrast media, although its use is indispensable for performing the test to evaluate possible complications and to study the vascularization of the abdominal wall. The positive oral contrast (iodinated or barium) can help with the identification of small bowel herniated loops and differentiate hernias from seromas or other liquid content collection.

Magnetic Resonance Imaging (MRI) is a safe imaging technique that uses magnetic properties of protons to produce high contrast resolution images. Compared to CT, MRI is less available, has lower spatial resolution, has more sensitivity to motion artifacts, and takes longer to perform; therefore, most centers use it less than CT to evaluate the abdominal wall.

It is recommended that CTs and MRIs be carried out with the Valsalva ¹ maneuver, since the supine position reduces intra-abdominal pressure, therefore reducing the herniated content and even decreasing the orifice diameters (see Fig. 47.1a, b).

Surgical repair of large hernias requires the preparation of the patient to receive the visceral content from the hernia sac into an abdominal cavity reduced by the retraction of anterolateral abdominal muscles and the secondary loss of the diaphragm muscle’s function that cannot find support to recover its concavity after contracting due to the loss of the abdominal wall’s tone.

To make the reduction of hernia content possible without the negative consequences of the increased intra-abdominal pressure and the respiratory restriction that would cause its immediate reduction, the PPP is used.

The Argentine surgeon Iván Goñi Moreno (1905–1976) (Fig. 47.2) noticed the abdominal distension that occurred in some patients after accidental air leakage into the peritoneal cavity during the diagnostic retro-pneumoperitoneum that was performed at the time as double contrast technique to study kidneys and adrenal glands, reporting its usefulness to repair large eventrations in the XII Argentine Congress in October 1940 and publishing his experiences years later (1946). Since then, the preoperative progressive pneumoperitoneum has been used to increase the size of the abdominal cavity in the repair of large eventrations, facilitating the reduction of the hernia sac content and the closure of the abdominal wall without tension. It has avoided space conflicts, high intra-abdominal pressure, and its most severe consequence, the Abdominal Compartment Syndrome (ACS).

The way to conduct the pneumoperitoneum may vary, but it basically consists of the introduction of environment air through a catheter that is placed in the peritoneal cavity through the abdominal wall. At our hospital, an eight French catheter is introduced, with the guidance of ultrasound, into the peritoneal cavity at one of the sides of the abdomen, based on the characteristics and location of the eventration. Usually patients are admitted 7–10 days before surgical intervention in order to conduct progressive pneumoperitoneum. The preoperative progressive pneumoperitoneum is intended to stabilize the diaphragm muscle, stimulating its function, and to dissect lax adherences inside the hernia sac by the action of introduced air. To prevent the air from distending only the hernia sac, where it will usually settle itself because of its lower pressure, an abdominal binder will be placed on the patient, allowing air distribution in the abdominal cavity and increasing the efficacy of the procedure as the total volume of air required is reduced, shortening the duration of the procedure.

The increase in the abdominal cavity affecting anterolateral muscles of the abdominal wall requires the procedure to be longer, in the experience of Dr. León Herszage (Fig. 47.3), no less than 30 days.

In our experience, admitting the patient 7–10 days before the surgical intervention is sufficient to achieve the first two objectives of developing the pneumoperitoneum: give functional support to the diaphragm muscle and promote a pneumatic dissection of the hernia content, achieving its partial or complete reduction to the abdominal cavity. To increase the capacity of this cavity, we have always been confident in the use of autoplastic techniques, with good results. During the preoperative period, a functional respiratory study and chest physiotherapy should be conducted.

Some medical schools, such as those in Mexico, combine performing the PPP with the use of Botulinum Toxin on the muscles of the abdominal wall, so that the pneumoperitoneum results are more effective due to muscle paralysis.

This is a technique described by Dr. Tomás Ibarra (Fig. 47.4) in 2007 and published in 2009. The botulinum toxin type A is used by infiltrating it in the side muscles of the abdomen (transverse and oblique of both sides) in order to cause a temporary paralysis, reducing therefore the pressures that tend to separate the rectus muscles and enlarge the hernia defects, allowing also an increase of the abdominal cavity volume up to a maximum of 20 % of its initial capacity in a period of 30 days [1].

The effect of the toxin is to block the release of acetylcholine at the motor plate of the nerve ending. This effect is complete and fully reversible in a period of 5–8 months. Subsequently, the release of acetylcholine will return to its previous values with no adverse effect on muscle contractility.

The right place for the infiltration of the toxin is determined by electromyography, locating the sites with more electrical activity. There are 5 points in which, constantly and in most patients, a total paralysis of the 3 muscles can be induced with post-infiltration electromyography control. The points are located as follows: two at the midaxillary line, equidistant between the lower costal edge and the iliac crest, and another three points at the level of anterior axillary line. Nowadays Dr. Ibarra and cols. They determine these five points using anatomical references with the help of transverse CT images to measure the distance from the skin to the muscle planes in both abdominal sides (see Fig. 47.5).

For this technique, 50 U of the toxin is infiltrated in each of the five specific points of the right side and five of the left side, for a total of 500 U. The toxin is prepared by diluting the lyophilized powder in 10 ml of saline solution (1 ml = 50 U) or, if preferred, in 20 ml (2 ml = 50 U).

Total paralysis of the muscles is achieved during the first 10 days, and dilatation of the abdominal wall and the reduction of the hernia defect horizontally, without compromising the trunk movements or respiratory function, will commence. Usually, patients have no discomfort, and only some of them referred to feeling a slight flaccidness at the sides of abdomen. The maximum muscle relaxation is reached within 30 days, with an average of 20 % of volume gain, and, according to the authors’ experience, there are no more volume increases afterwards (see Fig. 47.6).

It is therefore suggested that the wall repair procedure be performed after 30 days, with the advantage of still having 5–6 months of toxin effect so as to protect the suture line of the repair, which should always be reinforced with a mesh.

Another option to achieve progressive distension of lateral muscles prior to surgical repair is placing silicone expanders between the bellies of the oblique muscles. The tissue expansion obtained provides autologous tissue, as well as vascularized, with contractile capacity for the repair of defect in the abdominal wall. This procedure can be combined with the use of Botulinum Toxin.

In 1989, Henry Stephenson Byrd, a surgeon from Texas, published on the use of expanders in children with congenital abdominal abnormalities (bladder exstrophy and absence of lower half of the abdominal wall) [2]. Paul Creighton Hobar in 1994 published on the first case of abdominal wall reconstruction of an acquired defect.

The skin incision should be performed to ensure that there are no injuries in the neurovascular bundles that supply the abdominal wall, strictly respecting the anatomical planes. Normally, expanders are placed between the external oblique and the internal oblique deep complex and the fascia transversalis, this being one of the safest areas to place the expander, without interrupting blood supply or innervations of abdominal wall muscles.

A transversal incision has to be made, not a vertical one, in the costal margin, through the fascia of external oblique, so that no nerves or vessels are affected; at this plane level, between the fascia of the external oblique and the internal oblique, the pocket where the expander is placed is formed, limiting its lower edge with the inguinal ligament, medially with the lateral margin of the rectus, laterally with the midaxillary level, where the neurovascular perforating vessels of the external oblique can be found, and at superior level, with the costal margin (see Fig. 47.7).

The first expansion is started within 3 weeks, and the total process lasts approximately between 6 and 12 weeks until there is enough tissue; at that moment, the expander is removed and we proceed with the advance of the flap. Later, a layered closure without tension of the obtained tissue will be performed. The frequency and volume of the expansion will depend on the tolerance level of the patient, and it is normally performed every 2 weeks. The expansion at both sides of the abdominal wall defect will speed up the resolution time.

However, it is obvious that this procedure should be done in selected patients with good skin coverage.

In May 1946, Dr. Alfonso R. Albanese (1906–2008) (Fig. 47.8) operated on a 4-year-old patient who had a large midline hernia with an 8–10 cm diameter hernial ring due to a surgery done 8 months before in order to repair the obstructive symptoms that caused the peritoneal bands on the duodenum after an intestinal malrotation (Ladd’s bands).

Dr. Albanese worked in the Surgery Department of the Hospital Rawson (Buenos Aires), and the chief was Dr. Ricardo Finochietto. There they usually applied the Quénu-Noble technique to repair incisional hernias. Albanese also was an assistant in the Department of Topographical Anatomy of the University of Buenos Aires where he prepared anatomical materials for the classes of Professor Eugenio A. Galli. Albanese had passion for anatomy, a dedication that made him the creator of various surgical procedures, pioneering surgical repair of cardiac malformations in addition to the surgical technique for repairing large abdominal hernias.

His technique is designed to free the rectus muscle from the lateral traction of the oblique muscles as a result of the loss of continuity of the oblique muscles on each other.

With the completion of three longitudinal incisions in every hemiabdomen—one over the aponeurosis of the external oblique muscle (Fig. 47.9a), the second one in the anterior lamina of the internal oblique muscle just on the outer edge of the rectus muscle (Fig. 47.9b), and the third one on the inner third of the anterior sheath of rectus muscle (Fig. 47.9c)—this technique: