Operative surgery & topographical anatomy of the abdomen. Surgical anatomy of the inguinal canal and spermatic cord. Surgical anatomy of the inguinal canal and spermatic cord. Topographical peculiarities of the inguinal hernias.The descendense of the testicle, formation of scrotal layers. Boundaries: Superior boundary is formed by the margins of the costal arches (arcus costae) and xyphoid process Inferior boundary is formed by the inguinal folds, which are coincide with inguinal ligaments and pubic symphysis The lateral boundaries are the middle axillary (Lesgaft’s) lines. By two horizontal lines the anterior wall is divided into 3 regions: 1. Epigastrium 2. Mesogastrium 3. Hypogastrium The first horizontal line is between the lower points of the 10th pair of ribs and is called bicostal line (linea bicostarum) The second horizontal line is between spinae iliacae anteriores superiores and is called bispinal line (linea bispinarum) By two vertical lines which pass from the lower points of the 10th pair of ribs to the pubic tubercles the mesogastrium and hypogastrium are divided into three regions . The mesogastrium – into umbilical, right and left abdominal lateral regions, the hypogastrium – into pubic, right and left inguinal regions. So there are formed seven regions. If there will be drawn two vertical lines which coincide with the midclavicular lines to the pubic tubercles the epigastrium also can divided into three regions – the epigastric, right and left hypochondric regions. So nine regions are formed. Layers of anterior abdominal wall: 1. Skin is thin, elastic, moveable, except umbilical region, is covered by hair only in the pubic and inguinal parts, with sebaceous and sweat glands. In lateral parts rich with elastic fibres, which run from up to down, from lateral to medial sides. This fact is considered in abdominal surgery. 2. Subcutaneous fatty tissue (panniculus adiposus), is well developed. In inferior part of anterior abdominal wall it is much expressed, especially for fatty persons, but in umbilical ring it is absent. Below the umbilicus subcutaneous fatty tissue by the superficial fascia is divided into superficial and deep layers, the superficial fatty tissue has cellular structure, the deep one is continuous fat (acellular). 3. The superficial fascia is the continuation of the general superficial fascia of the body, in the inferior part of the wall consists of two layers that contain a variable amount of fat. In the inferior part of the wall, the layers of the superficial fascia are superficial and deep: a. A fatty superficial layer (Camper’s fascia) is extended to other regions as a superficial fascia of the whole body. b. A membranous deep layer (Thomson’s fascia) is started from the level of umbilical ring and attached to the inguinal ligament. From the pubic symphisis it continuous to the scrotum and perineum as superficial fascia. The well developed proper fascia in anterior abdominal wall is absent, but the thin connective tissue membrane is covered the each muscle of this region. In the margin between the muscular fibres and aponeurosis it fuses with the last one. The musculoaponeurotic layers accomplish the tonus of the abdominal cavity and intraabdominal pressure. 4. The external oblique (m. obliquus abdominis externus) is a superficial flat muscle; starts from the lower 8 ribs (5-12 ribs), the fibres are intercrossed with the fibres of the latissimus dorsi muscle and anterior serrate muscle, with which it covers the inferior parts of the thorax. Then it descends to the abdominal lateral and anterior parts. The muscular fibres are directed from up to down, from lateral to medial. At the lateral margin of the rectus abdominis muscle the external oblique muscle fibres are replaced by aponeurosis, which participate in formation of the sheath of rectus abdominis muscle. In the lateral margin of the inguinal region the inferior part of aponeurosis is thickened and form the inguinal ligament (lig. inguinale s. Puparti), its fibers pass inferomedially and attached to the spina iliaca anterior superior and tuberculum pubicum. The length of inguinal ligament is 12-16 cm. In the inferior angle of inguinal region the aponeurosis of the external oblique muscle is divided into two parts called crura (superior and inferior). Superior crus is attached to the symphisis pubis and inferior one - to the tuberculum pubis. Between the superior and inferior crura the intercrural fibres (fibrae intercrurales) are located. This kind of fibers we can find also in the inferior part again between the pedicles. The ligament is called Colles’ ligament (lig. reflexum s. Collesi). Superior and inferior crura, intercrural fibers and reflex ligament form the superficial inguinal ring (annulus inguinalis externus s. subcutaneous). Inferiorly the external oblique muscle fibres are attached to the anterior 2/3 of the iliac crest. 5. The internal oblique (m. obliquus abdominis internus) is the intermediate flat muscle. Its fibers have fan-like direction. They run at right angle (from down to up, from lateral to medial) to those of the external oblique in the upper part. In the middle part they run horizontally. In the lower part they pass downwards (same as external oblique muscle fibres) and are attached to the anterior part of the iliac crest and to the lateral half of the inguinal ligament. Posteriorly it starts from the thoracodorsal (thoracolumbar) fascia. Superiorly it begins from the lower parts of the costal arch. Medially the muscular fibres are replaced by aponeurosis, which subdivided into two lamins. Anterior lamina participate in formation of anterior wall of rectus muscle sheath, while the posterior lamina – in posterior wall of rectus muscle sheath. In 2-5 cm below the umbilicus the aponeurosis without subdivision runs in front of rectus muscle and participate in formation of anterior wall of rectus muscle sheath. In inguinal region the muscular fibres do not reach the inferior margin and freely hang in some distance. 6. The transversus abdominis (m. transversus abdominis) is the innermost flat muscle; its fibers except the inferior ones, run more or less horizontally. Superiorly it starts from posterior surfaces of lower 6 ribs, where it interlace with the diaphragm. Posteriorly it continuous from the anterior lamina of thoracodorsal fascia. Medially the muscular fibres are replaced by aponeurosis. Till the level of 2-5 cm below the umbilicus the aponeurosis runs posteriorly from the rectus muscle, below this level it goes anteriorly from the rectus muscle and participate in formation of rectus muscle sheath. In the inferior margin of inguinal region the muscular fibres remains freely hang in some distance. Inferiorly laterally the transversus abdominis muscle attached to the iliac crest. 7. Rectus muscle of the abdomen (m. rectus abdominis) has vertical direction to two sides from the midline. Starts from the xiphoid process and external surfaces of 5-7 rib cartilages and costal arch to the pubic symphisis. Pyramidal muscle is located medial to the rectus muscle in the inferior part and starts from the superior margin of the pubic bone to the linea alba, which can absent in 16-17 %. The muscle is interrupted by 3 tendinous intersections (intersectiones tendineae) on its extent, which are located at the level of the xiphoid process, umbilicus and halfway between these two structures. All three flat muscles end medially in a strong sheet like aponeurosis. The fibers of each aponeurisis interlace at the linea alba abdominis with their fellows of the opposite side to form the sheath of the rectus muscle. The rectus sheath is different above and below the umbilicus. The anterior wall of the sheath in its superior part consists of the aponeuroses of the external oblique and the anterior layer of the internal oblique muscles. Posterior wall consists of the posterior layer of internal oblique and transversus abdominis aponeuroses. The anterior wall of the inferior part (2-5 cm below umbilicus) consists of aponeuroses of the external oblique, internal oblique and transversus abdominis muscles. Posteriorly from the rectus muscle 2-5 cm below umbilicus remains the linea arcuata s.Duglas’s line. Inner surface of the rectus muscle is covered only by transversalis fascia. At level of the costal arches anteriorly from the rectus muscle is the aponeurosis of the external oblique muscle and posteriorly it attaches to the 5-7 rib cartilages. Laterally from the rectus muscle, at the place, where muscular fibres of three flat muscles are continuous by aponeurosis is formed the semilunar line, linea semilunaris s. Shpigel’s line, one of the delicate places of the anteriorabdominal wall. linea alba abdominis continuous from the xyphoid process till the pubic symphisis, by length 30-40 cm. Above umbilicus it is broad (1-2 cm width) and flat, while below umbilicus it become thicker and narrower. Above umbilicus linea alba is formed by fusion of anterior and posterior walls of rectus muscle sheath, that’s why the vaginas of rectus muscles are not communicated each other, and besides the single part of one vagina of rectus muscle does not communicate with neighbor parts because the tendinous intersections are fused with the wall of rectus muscle sheath. It is important for localized purulent process. 2-5 cm below the umbilicus linea alba is formed by fusion of anterior walls of rectus muscle sheath (aponeurosis of oblique external, internal and transverse muscles), so the right and left vaginas of rectus muscles are communicated each other. Superiorly in the sheath of the rectus muscle posterior to the muscle two arteries are located: a. epigastrica superior (branch of a.thoracica interna) with double veins. 8. A firm membranous sheet fascia transversalis is the part of the endoabdominal fascia, which covers the abdominal wall from inside. This fascia covers the deep surface of the transversus abdominis muscle and its aponeurosis, so here it is called transversalis fascia.