Ministry of Healthcare of Ukraine Danylo Halytsky Lviv National Medical University
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MINISTRY OF HEALTHCARE OF UKRAINE DANYLO HALYTSKY LVIV NATIONAL MEDICAL UNIVERSITY DEPARTMENT OF SURGERY #1 ABDOMINAL HERNIA CLASSIFICATION. ETIOLOGY AND PATHOGENESIS. CLINICAL PRESENTATION. PRINCIPELS OF SURGICAL TREATMENT. COMPLICATIONS Guidelines for Medical Students LVIV – 2019 Approved at the meeting of the surgical methodological commission of Danylo Halytsky Lviv National Medical University (Meeting report № 56 on May 16, 2019) Guidelines prepared: GERYCH Igor Dyonizovych – PhD, professor, head of Department of Surgery #1 at Danylo Halytsky Lviv National Medical University VARYVODA Eugene Stepanovych – PhD, associate professor of Department of Surgery #1 at Danylo Halytsky Lviv National Medical University STOYANOVSKY Igor Volodymyrovych – PhD, assistant professor of Department of Surgery #1 at Danylo Halytsky Lviv National Medical University CHEMERYS Orest Myroslavovych – PhD, assistant professor of Department of Surgery #1 at Danylo Halytsky Lviv National Medical University Referees: ANDRYUSHCHENKO Viktor Petrovych – PhD, professor of Department of General Surgery at Danylo Halytsky Lviv National Medical University OREL Yuriy Glibovych - PhD, professor of Department of General Surgery at Danylo Halytsky Lviv National Medical University Responsible for the issue first vice-rector on educational and pedagogical affairs at Danylo Halytsky Lviv National Medical University, corresponding member of National Academy of Medical Sciences of Ukraine, PhD, professor M.R. Gzegotsky I. Background A hernia is an abnormal protrusion of a viscus or part of a viscus through a defect either in the containing wall of that viscus or within the cavity in which the viscus normally is situated. In abdominal hernias, the ‘wall’ refers to the anterior and posterior muscle layers of the abdomen, the diaphragm, and the walls of the pelvis. Hernias are composed of a sac, the parts of which are described as the neck, body and fundus, and the hernial contents. The sac consists of peritoneum which protrudes through the abdominal wall defect or ‘hernial orifice’, and envelopes the hernial contents. The neck of the sac is situated at the defect. Hernias with a narrow or rigid neck are more likely to obstruct and strangulate. The body is the widest part of the hernial sac, and the fundus is the apex or furthest extremity. Viscera most likely to enter a hernial sac are those normally situated in the region of the defect and those which are mobile, namely the omentum, small intestine and colon. Some hernial contents have been ascribed generic names. II. Learning Objectives 1. To study the etiological factors of disease, classification of hernias, clinical signs, diagnostic methods, treatment and complications (α = I). 2. To know the main causes of the disease, typical clinical course and complications, diagnostic value of laboratory and instrumental methods of examination and the principles of the modern conservative and surgical treatment (α = II). 3. To be able to collect and analyze the complaints and disease history, thoroughly perform physical examination, determine the order of the most informative examination methods and perform their interpretation, establish clinical diagnosis, justify the indications for surgery, choose adequate method of surgical intervention (α = III). 4. To develop creativity in solving complicated clinical tasks in patients with atypical clinical course or complications of hernias (α = ІV). III. Purpose of personality development Development of professional skills of the future specialist, study of ethical and deontological aspects of physicians job, regarding communication with patients and colleagues, development of a sense of responsibility for independent decision making. To know modern methods of treatment of patients with hernias and its complications. IV. Interdisciplinary integration Subject To know To be able Previous subjects 1. Anatomy and Anatomical structure, Determine the structure of Physiology innervation and of the inguinal and femoral chanels imguinal area 2. Pathomorphology Etiological factors of Describe different types of and Pathophysiology disease hernias 3. Propedeutics of Sequence of patient’s Determine the patients internal diseases survey and physical complaints, medical history examination of the of the disease, perform abdominal cavity superficial and deep palpation of the abdomen 4. Pharmacology Groups and Prescribe conservative representatives of treatment of patient with antibiotics, spasmolytics, hernias analgesics, antiinflammatory drugs, colloid and crystalloid solutions 5. Radiology Efficiency of radiological Indications and descrition of investigation in patients x-ray, ultrasound, computed with hernias tomography examination Future subjects Anesthesiology and Clinical signs urgent Determine the symptoms of Critical Care conditions that occur in urgent conditions, differential Medicine patients with diagnosis and treatment complications of hernias, methods of diagnosis and pharmacotherapy Intradisciplinary integration 1. Acute pancreatitis Clinical picture of acute Check Mondor’s, Grey- pancreatitis Turner’s, Cullen’s, Mayo- Robson’s signs 2. Acute cholecystitis Clinical picture of acute Check Ortner’s, Kehr’s, cholecystitis Merphy’s, Mussy’s signs 3. Peptic ulcer of Clinical picture of peptic Check Blumberg’s sign, stomach and ulcer of stomach and describe plain abdominal film duodenum duodenum in patient with peptic ulcer perforation 4. Acute bowel Clinical picture of acute Describe x-ray signs of acute obstruction bowel obstruction bowel obstruction 5. Renal colic Clinical signs of renal Check Pasternasky’s sign colic V. Content of the topic and its structuring Classification of hernias due to International Classification of Diseases 1. Inguinal hernia (code K 40). 2. Femoral hernia (code K 41). 3. Umbilical hernia (code K 42). 4. Abdominal wall hernia (code K 43). 5. Diaphragmatic hernia (code K 44). 6. Other hernia of abdominal cavity (code K 45). 7. Unspecified hernia of the abdominal cavity (code K 46). Richter’s hernia Only part of the circumference of the bowel (usually the anti-mesenteric border) is trapped within the hernial sac. The herniated part may become ischaemic. Because the lumen of the bowel is not occluded, intestinal obstruction does not occur, and there are few symptoms until the ischaemic part perforates. Littre’s hernia A Meckel’s diverticulum lies within the hernial sac. Littr´e’s hernia occurs most commonly in a femoral or inguinal hernia. Maydl’s hernia The hernial sac contains two loops of intestine. The loop of intestine within the abdominal cavity may become obstructed or strangulated, and this may not be recognised unless the hernial contents are inspected and returned to the abdominal cavity (‘reduced’) completely. Predisposing factors A hernia occurs because of (a) weakness or defect in the abdominal wall, and (b) positive intra-abdominal pressure (IAP) (which is often raised) forces the viscus into the defect. Sites of weakness in the abdominal wall Weaknesses in the abdominal wall may be: - Congenital (i.e. present at birth) – e.g. patent processus vaginalis or canal of Nuck, posterolateral or anterior parasternal diaphragmatic defect, patent umbilical ring in children. - Where a normal anatomical structure passes through the abdominal wall – e.g. oesophageal hiatus, umbilical ligament in adults, obturator foramen, sciatic foramen. - Acquired – e.g. surgical scar, site of an intestinal stoma, muscle wasting with increasing age, fatty infiltration of tissues because of obesity. Increased intra-abdominal pressure Raised intra-abdominal pressure (IAP) stretches the abdominal vertically and horizontally, thereby increasing the circumference of any defect. Also, high IAP forces abdominal contents through a defect. Sudden or sustained increases in IAP are due to several causes: - Coughing - Vomiting - Straining during urination or defecation - Pregnancy and childbirth - Occupational heavy lifting or straining, and strenuous muscular exercise - Obesity - Ascites - Continuous ambulatory peritoneal dialysis (CAPD) - Gross organomegaly COMPLICATIONS Most hernias are uncomplicated at presentation. The three important complications of hernias are, in order of progression, irreducibility, obstruction and strangulation. Irreducibility A hernia is ‘irreducible’ when the sac cannot be emptied completely of contents. Irreducibility is caused by (i) adhesions between the sac and its contents, (ii) fibrosis leading to narrowing at the neck of the sac, or (iii) a sudden increase in IAP that causes transient stretching of the neck and forceful movement into the sac of contents, which cannot subsequently return to their original location. Generally, irreducible hernias should be operated on soon after presentation. Although irreducibility is not an indication for urgent operation, it is the step before obstruction supervenes. In addition, irreducible hernias are usually painful. Obstruction A hernia becomes obstructed when the neck is sufficiently narrow to occlude the lumen of the intestine contained within the sac. Obstructed hernias are nearly always irreducible and, if not treated, may become strangulated. Often, there is a history of a sudden increase in IAP that has pushed intestine or other contents into the sac. The patient presents with symptoms and signs of intestinal obstruction (abdominal colic, vomiting, constipation, abdominal distension), together with a tender irreducible hernia. Failure to examine the hernia orifices in a patient with intestinal obstruction