“approved”
Скачати 32.91 Kb.
|
|
Ministry of Health of Ukraine Bukovinian State Medical University “APPROVED”on methodical meeting of the Department of Anatomy, Topographical anatomy and Operative Surgery “………”…………………….2008 р. (Protocol №……….) The chief of departmentprofessor ……………………….……Yu.T.Achtemiichuk “………”…………………….2008 р. METHODICAL GUIDELINESfor the 3d-year foreign students of English-spoken groups of the Medical Faculty (speciality “General medicine”) for independent work during the preparation to practical studiesthe Theme of studies “Clinical anatomy and operative surgery of the umbilical, femoral and linea alba hernias” MODULE I Topographical Anatomy and Operative Surgery of the Head, Neck, Thorax and Abdomen Semantic module 3 “Topographical Anatomy and Operative Surgery of the Abdomen” Chernivtsi – 2008 1. Actuality of theme: The topographical anatomy and operative surgery of the abdomen are very importance, because without the knowledge about peculiarities and variants of structure, form, location and mutual location of abdominal anatomical structures, their age-specific it is impossible to diagnose in a proper time and correctly and to prescribe a necessary treatment to the patient. Surgeons usually pay much attention to the topographo-anatomic basis of surgical operations on the abdomen. ^ 2 working hours. 3. Objectives (concrete purposes): To know the definition of regions of the abdomen. To know classification of surgical operations on the abdomen. To know the topographical anatomy and operative surgery of the organs of the abdomenal cavity. ^
^ 5.1. Table of contents of the theme: The Linea Alba and Rectus Sheath. These structures have been mentioned several times and have been briefly described; however, owing to their clinical importance, a more detailed description and summary of the rectus sheath and its relationship to the linea alba follows. The rectus sheath is the strong, incomplete fibrous compartment of the rectus abdominis muscle. It forms by the fusion an separation of the aponeuroses of the flat abdominal muscles. At its lateral margin, the internal oblique aponeurosis split: into two layers, one passing anterior to the rectus muscle an the other passing posterior to it. The anterior layer joins with the aponeurosis of the external oblique to form the anterior wall of the rectus sheath. The posterior layer joins with the aponeurosis of the transversus abdominis muscle to form the posterior wall of the rectus sheath. The fibers of the anterior and posterior walls of the sheath interlace in the anterior median line to form a complex tendinous raphe, called the linea alba, which is an intermixture of the aponeurotic fibers of this oblique and transverse abdominal muscles. It is narrow inferior to the umbilicus, but is wide superior to it A groove is visible in the skin superficial to it in thin muscular persons. The linea alba lies between the two parts of the rectus abdominis muscle; the umbilicus is located just inferior to its midpoint. Superior to the costal margin, the posterior wall of the rectus sheath is deficient because the transversus abdominis muscles passes internal to the costal cartilages and the internal obliqus muscle is attached to the costal margin. Hence, superior to the costal margin, the rectus muscle lies directly on the thoracic wall. The inferior one-fourth of the rectus sheath is also deficient because the internal oblique aponeurosis does not split here to enclose the rectus muscle. The inferior limit of the posterior wall of the rectus sheath is marked by a crescentic border called the arcuate line. The position of this line is usually midway between the umbilicus and the pubic crest. Inferior to the arcuate line, the aponeuroses of this three flat muscles pass anterior to the rectus muscle to form this anterior layer of the rectus sheath. ^ in addition to this rectus abdominis muscle, are the superior and inferior epigastrh vessels, and the terminal parts of the inferior five intercostal and subcostal vessels and nerves. Umbilical Hernia Umbilical hernia, is associated with failure of complete closure of the umbilical orifice during the 1st year of postnatal life. It is often noticed when the infant cries, which raises the intra-abdominal pressure and causes protrusion of part of the intestine. Surgery becomes essential when the defect is relatively large and persists beyond the age of 4, or becomes incarcerated. In the adult, umbilical hernia may develop more commonly in women, usually postpartum, and a pose serious danger due to the rigid walls of the linea alba, which predisposes the hernial sac to strangulation and incarceration. Herniation immediately above or below the umbilicus is known as paraumbilical hernia, and occurs in women with multiple pregnancies. It is usually prone to incarceration and usually contains part of the greater omentum. Omphalocele Omphalocele is a rare but severe congenital umbilical hernia in which part of a visceral organ protrudes through the umbilical ring into the base of the umbilical cord. This condition begins when the cranial limb of the gut loop coils and rapidly increases in length, protruding through the umbilical ring into the extraembryonic coelomic cavity. This physiological herniation occurs around the 6th week of development, followed by the return of the protruding part of the gut into the enlarged abdominal cavity around the 10th week. Retention of the herniated gut outside the abdomen beyond the 10th week of development is designated as omphalocele. The hernial sac in this case is covered by the combination of a thin layer of peritoneum and by the amnion. In a study involving a large number of consecutive births, the overall survival rate was much lower for omphalocele than for gastroschisis. The same study confirmed that omphalocele is usually associated with older maternal age pregnancies, and is more often complicated by threatened abortion. ^ A femoral hernia presents a hernial sac that protrudes anterior to the pectineal (Cooper’s) ligament and through the femoral canal, a potential space between the lacunar ligament and the femoral vein. The femoral ring, which is the upper margin of the femoral canal, is the medial portion of the lacuna vasorum. It is bounded anteriorly by the extension of the transversalis fascia, and posteriorly by the continuation of the pectineal fascia. The neck of the hernial sac is always distal and lateral to the pubic tubercle, a bony landmark between the site of inguinal and femoral hernia. The fundus of the hernial sac (lower part) usually occupies themedial part of the femoral triangle. The hernial sac traverses the femoral canal and descends vertically posterior to the inguinal ligament, displacing the femoral vein, to exit through the saphenous opening. It tends to ascend from this point proximally, by following the superficial epigastric vessels anterior to the inguinal ligament and the lower part of the external oblique. The hernial sac may turn medially and toward the scrotum or major labium. It may also descend anterior (prevascular hernia) or posterior (retrovascular hernia) to the femoral vessels. It is prevented from descending further down by the attachment of the femoral sheath and the superficial fascia of the thigh to themargins of the saphenous opening. The course of progression of the hernial sac should be taken into consideration and reduction of femoral hernia should be directed in the reverse direction with the thighs passively flexed. Femoral hernia is more common in female than male at the ratio of 3:1. It affects approximately 35% of the female population particularly in women over 50 years of age. This gender-based difference is attributed to the unique shape of the pelvis, the size of the ring, and the dramatic changes exerted during pregnancy. Its incidence is far lower than that of inguinal hernia and can be easily missed during physical examination. There is a dramatic correlation between inguinal hernial repair and the incidence of femoral hernia. The scientists reported a 15-fold greater incidence of femoral hernia postinguinal herniorrhaphy compared with spontaneous incidence. Due to the rarity of the femoral hernia in children and the similarity of its manifestations to that of the indirect inguinal hernia, femoral hernia in this population remains a challenging clinical problem. Misdiagnosis of femoral hernia may be perpetuated by the presence of a patent processus vaginalis and incidental indirect inguinal hernia. A variety of conditionsmust be excluded in the differential diagnosis of femoral hernia such as lipoma, psoas abscess, obturator hernia, lipoma, and hydrocele. The femoral hernial sac consists of the parietal peritoneum, femoral septum (extraperitoneal tissue), femoral sheath, cribriform fascia (covers the saphenous opening), superficial fascia, andskin. It frequently contains the small intestine and omentum, but the presence of an inflamed appendix, Meckel’s diverticulum, or portion of the bladder should also be expected. Occasionally the ureter or broad ligament of the uterus may also be found. Femoral hernial sac becomes irreducible when it attains a large size, protruding anterior to the inguinal ligament. Due to the ligamentous boundaries, the hernial sac carries a higher risk of strangulation and should be considered part of the differential diagnosis in pregnant women and in individuals with intestinal obstruction. The strangulation is a frequent manifestation at the saphenous opening, the femoral ring, or at the junction of the inguinal ligament and falciform margin of the saphenous opening. An incisional hernia is a protrusion of an organ or tissue through a surgical incision. The surgeon who has a thorough knowledge of the anatomy of the anterolateral abdominal wall and makes incisions accordingly will only occasionally have to operate on this kind of hernia. However, if the muscular and tendinous layers of the abdomen do not heal properly, an incisional hernia can result. Infection and/or obesity are predisposing factors. Because the inferior intercostal nerves (T11 and T12) and the iliohypogastric and ilioinguinal nerves (LI) supply the abdominal musculature, injury to them during surgery or an accident could result in weakening of muscles in the inguinal region, creating a predisposition to development of direct inguinal hernia. The ilioinguinal nerve also gives off motor branches to the fibers of the internal oblique muscle, which are inserted into the lateral border of the conjoint tendon. Division of this nerve paralyzes these fibers and weakens the conjoint tendon; this may also result in a direct inguinal hernia. ^
^
Literature 1. Snell R.S. Clinical Anatomy for medical students. – Lippincott Williams & Wilkins, 2000. – 898 p. 2. Skandalakis J.E., Skandalakis P.N., Skandalakis L.J. Surgical Anatomy and Technique. – Springer, 1995. – 674 p. 3. Netter F.H. Atlas of human anatomy. – Ciba-Geigy Co., 1994. – 514 p. 4. Ellis H. Clinical Anatomy Arevision and applied anatomy for clinical students. – Blackwell publishing, 2006. – 439 p. |
Схожі:
 | “approved” | | “approved” |
| “approved” | | “approved” |
| “approved” | | “approved” |
| “approved” | | “approved” |
| Approved | | Approved |
| “approved” |