Appendicitis
Appendix is a vestigial organ present at a site where terminal ileum joins the cecum i.e. at ileocecal valve, at that region appendix lie at terminal end of the cecum.Surface anatomy
At right iliac fossa, at point of junction between the medial two third & lateral one third on a line join the umbilicus with anterior superior iliac spine, at this point appendix lie & called Mc burni point.
Blood supply
From superior mesenteric artery, terminal part of ileocecal artery gives ant. & post. cecal artery and those give branch to appendix called appendicular artery.
N.B: the terminal two third of appendicular artery lie in intimate contact with appendix.
Venous drainage
To superior mesenteric artery which go to portal vein.
Lymph node
Lymph node on colon called epicolic and on the side called paracolic and those on center of mesentery called central lymph node (A & B).
N.B: the important one here is paracolic lymph node.
Operative landmark of appendix
You find the cecum (there is no tinea on it) so you follow the tinea the point where tinea meet each other this is appendix.
Sometimes appendix is retroperitoneal, so you hook the cecum with your finger & feel the appendix under it.
Locations of appendix
There is 5 locations: preileal, post ilial, pelvic, retrocecal & paracecal & they are important in clinical presentation.
This difference occur in embryological stage, hind gut is midline organ then rotate to the right side & descend through this maneuver the difference occur, so either be in front of ileum or behind it or free in the pelvis or on the site of cecum or underneath cecum (retrocecal).
Most of the time appendix is peritonised but the tip of the appendix may be extra peritoneal.
In some times gut rotate but not descend so appendix lie in right hypochondrium so put it in differential diagnosis of cholecystitis.
Acute Appendicitis
Inflammation of appendix is one of the most common disease surgeon could face & among commonest operations perform daily.
Etiology
There is no single m.o could be named to be the cause of appendicitis, it's mixture of m.o mainly E.coli & anaerobe m.o.
pathogensis
There is theory said appendicitis mainly due to obstruction of the lumen of appendix by forign body called fecolith or appendicolith but this appendicolith not always present for that reseon this theory failed.
If we by accident see appendicolith this a sign to do prophylactic appendicectomy.
This fecolith is either Ca phosphate, fecal material or bacteria.
Catarrhal theory
There is mucosal inflammation mainly due to viral infection lead to inflammation & permeation to the aggregation of lymphatic lead to swelling & edema so lumen of the appendix closed because it's narrow lumen(matchstick) lead to entrapment of secretion & nourishing of normal flora , those m.o lead to increase the inflammatory process & lead to increase the intraluminal pressure so mucosa ulcerate & through ulceration, permeation of m.o through the wall occur. We said that two third of appendicular artery in intimate contact with appendix, so m.o reach the artery & thrombosis occur so the appendix will be ischemic & this will end in rupture of appendix.
Clinical presentation
Age incidence : Appendicitis is rare in neonate & old age because in neonate appendix is not well formed yet & in old age it's atrophied. In children male to female ratio is equal while in teenage & adult male is more affected than female.
The patient will complain central abdominal pain which either dull or colicky:
Colicky pain (intermittent) is due to presence of fecolith.
Dull pain (continuos) is not due to obstruction.
Periumbilical pain is due to embryological origination. at this stage the inflammation is still in somatic not reach parietal region. when it reach parietal region, it will cause peritonism & pain will shift from umbilical to right iliac fossa . This called shifting pain.
Anorexia, nausea & vomiting : The most important is anorexia accompanied by nausea ± once or twice vomiting.
Fever : at the beginning there is no raise of temperature. but when it raise to 38c or more, this mean patient have complication (peritonitis).
N.B: most of case came late (with complication).
Examination
On inspection : thoracic respiration & abdomin is silent i.e there is no thoraco-abdominal respiration, this mean acute abdomen.
By palpation:
Pointing sign: the patient put his hand on Mcburni point when asked him about painful area.
Cough: pain increase with coughing (increase intra abdominal pressure will increase the pain).
Palpation divided into :
superficial:
On right side you will see rigidity, guarding & maximum tenderness.
Rovsing sign: press on the left side & pain on right side occur & this occur because the air on right side will go to cecum & iliocecal valve is competent in one direction from ilium to cecum So pressure in cecum increased lead to increase pressure in appendix so pain increased. This called shifting tenderness.
Deep palpation: when you press gradually on Mcburni point & attract patient attention by talking to him, all of the sudden you release your hand
either: from the start the patient will feel severe pain under your hand, this mean patient has abscess.
or: when you release your hand suddenly the patient will jump from the bed, this because the anterior abdominal wall have the same resilience but peritoneum differ, so when you release your hand, anterior abdominal wall will return but peritoneum will lag then will return alone & stretch suddenly i.e elicit severe pain. This called rebound tenderness which is pathognomonic.
There is 3 things to do also:
If you see the patient flex his right hip, you make it straight , if he feel pain this mean he has "retrocecal appendix" because appendix lie on iliopsoas muscle, So when relaxed pain disappear & when contract it will cause pain. This called psoas sign.
If this not occur, we tell patient to lie on bed flex hip & internally rotate it, if he feel pain this mean appendix is in intimate contact with obturator muscle. This called obturator sign.
If psoas & obturator sign is negative, we must do PR , it's important when appendix lie free in the pelvis.
Percussion: The abdomen is resonant because there is pseudo intestinal obstruction & also we note maximum tenderness on Mcburni point.
Auscultation : It's not pathognomonic, in non complicated appendicitis auscultation is not relevant. In complicated case abdominal sound decrease because of peritonism & paralytic ilius.
N.B: you must auscultate heart & lung because basal pleurisy may misdiagnosed as appendicitis.
Fate of Appendicitis
If immunity is good or patient receive antibiotic & antispasmotic at cellular stage, appendix will resolve.
Appendicular mass: if inflammatory process reach parietal peritoneum and there is m.o on it or there is minute small perforation, greater omentum, small bowel, cecum & ant. Abdominal wall adhere to each other form a mass.
Appendicular abscess: if immunity is not very good & leaking is moderate or m.o is very virulent this will lead to abscess.
Generalized peritonitis and its complication (with high mortality and morbidity) most common morbidity is fibrosis, adhesion and repeated intestinal obstruction.
Complication of appendicitis
Acute appendicitis:Generalized peritonitis.
Appendicular mass.
Appendicular abscess.
Pelvic abscess.
Subdiaphramatic abscess.
Intestinal obstruction.
Late and chronic: intestinal obstruction due to band.
Written by: omer saadallah