42) Hernias скачать в хорошем качестве

42) Hernias

Hernias - an abd. protrusion of a part or whole of viscus through an abnormal openings in the wall of the cavity, which contains it. Aetiology –mainly 2 factors play in causing a hernia - 1)weakness of the abd. muscles & 2)increased abd. pressure which forces the content out through the normal abd. musculature. 1)weakness of the abd. muscles – a) Congetial, b) Acquired. a) Congetial weakness- i)presistent of processus vaginalis – causes indirect complete ingui. hernia. ii)similarelly patent canal of nuck in females- causes indirect complete ingui. hernia. iii)incomplete obliteration of umbilicus – may lead to infantile umbilical hernia. b)Acquired weakness- i)extensive fat in the abd. – causes weakness of abd. musculature fat. -fat separates muscle fibres - causes direct ingui. Hernia, para umbilical or hiatus hernia. ii)muscle weakness –followed by repeated pregnancy. iii)Surgical incision - may lead to division of nerve fibres -causes muscle weakness for example - a direct hernia may develops following appendicectomy due to division of ilio – inguinal nerve. iv)incisional hernia- developes through weakened abd. Muscles. -mostly protection in the early post operative period or excessive fat in the abd. wall predisposes incisional hernia. 2)Increased abd. Pressure -e.g. – i)whooping caugh in the children, ii) chronic cough in bronchitis, tuburculosis, etc.. iii)bladder neck obstruction or urthral stricture, iv)Enlarged prostate causing dysurea, v)Poerful muscular effort or straining during lifting heavy weight, vii)vomiting, vii)repeated pregnancy, viii)constipation. Pathology- A hernia conssist of 3 parts- I) the sac, II) the contents of the sac, III) the coverings the sac. i)the sac- -is a pouch of peritoneum which comes out through the abd. musculature. four parts of sac- (a) a mouth , (b) neck, (c) the body,(d) fundus . a)mouth – the opening of the sac, contents enter in the sac. b) neck – most constricted part of the sac. c)body – main portion of the sac. d) fundus -which is most redundant part of the sac. II)the contents – -the viscous which lies with in the sac of a hernia is called the contents of a hernia. -Depending on the contents, the hernia is variously named – e.g.- a)omentocele or epiplocele – the content is omentum. b) enterocele – the content is a loop of intestine. c) Richter’s hernia – portion of the circumference of the intestine. d)Littre’s hernia – content is meckle’s diverticulum . e)Maydl’s hernia- two loops of small intestine remain in the manner of ‘W’. f)Portion of bladder is sometimes present in a direct or sliding inguinal or a femoral hernia. g)Ovary with or without the fallopian tube. h)Fluid – slight fluid is almost always present more in ascites & blood stained when hernia is strangulated. iii)coverings - are the layers of the abd. wall which cover the hernial sac. -This includes the skin & muscles of the abd. Classification – i)reducible, ii)irreducible, iii)obstructed or incarcerated or iv)strangulated, v)inflamed. i)Reducible hernia- -when a hernia reduces itself as the patient lies down or can be reduced by the patient or by the surgen. ii)Irreducible hernia- -when the contents of the hernia cannot be returned back to the abdomen.. Various causes of irreducibility – i)adhensions of it’s contents to each other , ii)adhesions of contents with the sac, iii)narrowing of neck, iv)pressure of omentum in sac, v)massive hernia inside the scrotum (scrotal abdomen ) . femoral & umbilical hernia are often irreducible, irreducible hernia is dangerous & may lead to strangulation. obstructed or incarcerated hernia-it is a irreducibility plus intestinal obstruction. -obstructed hernia means that the hernia is associated with intestinal obstruction due to occlusion of the lumen of the bowel. Features of obstructed hernia – i)expansile coughing impulse is not present, ii)patient does not compalain of pain, iii)the hernia is irreducible, iv) the hernia is lax and not tender, v)features of intestinal obstruction. Strangulated hernia -(irreducibility + obstruction + arrest of blood supply of the contents ) -content becomes gangreous -neck of the sac is very much constricted. Pathology – -in the enterocele the venous return is first impeded . -The intestine becomes congested & bright red. -Serous fluid is seen oozing out into the sac. -As venous stasis increases, the arterial supply is also impaired. -Ecchymoses appear in the secrosa. -Serous layer becomes dull and covered with fibrinous exudate. -Gradually the intestine looses its tone and it feels flabby, -the viability of the intestine diminishes and this favours migration of bacteria through the intestinal wall and the fluid within the sac becomes full of bacteria & toxins. -In places of gangrene the colour changes from purple to black . Clinical features – -pain & vomiting, -such pain will only cease with the onset of gangrene & paralytic ileous .