appendicitis

Berengario DaCarpi, a physician-anatomist, made the first description of the appendix in 1521 Leonardo DaVinci demonstrated the appendix in drawings made in 1492 but not published until the 18th century. Lorenz Heister gave the first unequivocal account of appendicitis in 1711 The appendix is clearly illustrated in De Humani Corporis Febrica Liber V by Andreas Vesalius published in 1543
Vesalius A. De Humani Corporis Fabrica Liber V. Basel: Iohannis Oporini; 1543.

APPENDICITIS

History


Heister, a student of Boerhaave, described a perforation of the appendix with a small abscess adjacent to a gangrenous appendix Heister speculated that the appendix might be the site of acute inflammation. He described the autopsy on the body of a criminal Francois Melier, a Parisian physician, described 6 cases of appendicitis at autopsy and first suggested the possibility of removing the appendix in 1827

APPENDICITIS

History


Claudius Amyand, Sergeant Surgeon to George II, performed the first known appendectomy in 1735. He operated on an 11-year-old boy with a right scrotal hernia and a fistula. He identified the appendix, perforated by a pin, within the scrotum. He ligated the appendix and removed it.
Shepherd JA. Acute appendicitis: a historical survey. Lancet 1954;2:299-302.


APPENDICITIS

History

Fitz – 1886Proposed that the appendix is the cause of most inflammatory disease of the right lower quadrant. He went on to describe the clinical features of appendicitis and, importantly, proposed early surgical removal of the appendix Fitz RH. Perforating inflammation of the vermiform appendix: with special reference to its early diagnosis and treatment. Am J Med Sci 1886;92:321-46.

APPENDICITIS

History


In 1889, McBurney of New York published the first of several important papers regarding the appendix. He suggested early operative intervention and developed the muscle-splitting incision that bears his name and is commonly used today
McBurney C. Experience with early operative interference in cases of disease of the vermiform appendix. NY Med J 1889;50:676-84. McBurney C. The incision made in the abdominal wall in cases of appendicitis, with a description of a new method of operation. Ann Surg 1894;20:38-43.

APPENDICITIS

History


Lifetime risk – 6% to 7%Peak age – Adolescents and young adultsUncommon <5 and >50 yrs1 in 35 men1 in 50 womenMale:Female 1.3:1

APPENDICITIS

Introduction


More common in industrialised nations (refined, low fibre diet) Presumably, this diet leads to hard stool, higher intracolic pressure and faecolith formation Familial association is simply due to similar environment and dietary habits

APPENDICITIS

Introduction


Small lumen to length ratio Predisposed to closed loop obstruction, especially with proximal swelling or faecolith Ongoing mucosal secretion leads to elevated intraluminal pressure Venous pressure is exceeded and ischaemia develops Hypoxic mucosa begins to ulcerate Bacterial translocation


APPENDICITIS

Pathophysiology

Begins as peri-umbilical discomfort – poorly localised and unrelieved by stools.Loss of Appetite (80%)Nausea (+- vomiting)Diarrhoea (uncommon)6-12 hours later localised to RIF (localised peritonism)Less tenderness in retrocaecal or pelvic appendixPyrexia (37.5 to 38) – 25% to 50% have temp <37.5

APPENDICITIS

Clinical Features


Leukocytosis…Cardall and colleagues showed that fever and leukocytosis were not always present and cannot be wholly relied upon in the diagnosisPieper and colleagues reported 493 patients in which only 67% had a leukocyte count greater than 11.0CRP Cardall T, Glasser J, Guss DA. Clinical value of the total white blood cell count and termperature in the evaluation of patients with suspected appendicitis. Acad Emerg Med 2004;11:1021-7 Pieper R, Kager L, Nasman P. Acute appendicitis: a clinical study of 1018 cases of emergency appendectomy. Acta Chir Scand 1982;48:51-62.

APPENDICITIS

Clinical Features

APPENDICITIS

Clinical Features

PSOAS SIGN

The psoas sign. Pain on passive extension of the right thigh. Patient lies on left side. Examiner extends patient's right thigh while applying counter resistance to the right hip.
Anatomic basis for the psoas sign: inflamed appendix is in a retroperitoneal location in contact with the psoas muscle, which is stretched by this manoeuvre.

APPENDICITIS

Clinical Features

OBTURATOR SIGN

Pain on passive internal rotation of the flexed thigh. Examiner moves lower leg laterally while applying resistance to the lateral side of the knee resulting in internal rotation of the femur.
Anatomic basis for the obturator sign: inflamed appendix in the pelvis is in contact with the obturator internus muscle, which is stretched by this manoeuvre.


APPENDICITIS


Occurs in 20%-30% Longer duration of symptoms before presentation Age <3yrs and >50yrs Increasing abdominal pain (severity and sight) Temperature > 38 The morbidity of a negative appendectomy is preferable to the morbidity of perforated appendicitis

APPENDICITIS

Perforation - Clinical Features


Occurs in 10%Scenario – Develops RIF pain and fever for 1-2 days then resolves, then recurs 7-10 days laterPalpable massUltrasound or CT to confirm diagnosisAvoid surgery if possible, especially if appendix is difficult to find (discussed later)

APPENDICITIS

Peri-appendiceal Abscess - Clinical Features


Debatable existence Sinanan has shown it to be a real entity Recurrent attacks of RIF pain If interval appendectomy not done after medical Rx, 10-80% recurrence Histology in recurrent pain pts- chronic AND acute inflammation
Sinanan M. Acute Abdomen and Appendix. In: Greenfield LJ, Mulholland MW, Oldham KT, Zelenock GB, editors. Surgery: Scientific Principles and Practice. Philadelphia: JB Lippincott; 1993, pp 1120-42.


APPENDICITIS

Recurrent Appendicitis

Chronic RIF painIf appendectomy relieves pain, and histology shows chronic inflammation – Diagnosis is made retrospectively

APPENDICITIS

Chronic Appendicitis


3 factors…1) Extremes of age2) Variable appendiceal position3) Associated conditions (e.g. pregnancy, Crohn’s, antibiotics, steroids, recent abdominal surgery)

APPENDICITIS

Atypical Presentations


3 factors…1) Extremes of age Age 1-5 has 70% perforation rateAge < 1yr has almost 100% perforation rateREASONS…CommunicationShorter, incompletely formed omentum

APPENDICITIS

Atypical Presentations


3 factors…3) Associated conditions (e.g. pregnancy, Crohn’s, antibiotics, steroids, recent abdominal surgery) Pregnancy causes delays in diagnosisAbdominal pain, nausea, vomiting, leukocytosis all ‘normal’ for pregnancyAppendix moves to RUQ in 3rd trimester

APPENDICITIS

Atypical Presentations



Extra-abdominal – (Otitis, pneumonia, meningitis, URTI – can all present with abdominal pain, nausea, vomiting.Diarrhoea – usually suggestive of gastroenteritisMesenteric LymphadenitisMeckel’s diverticulitisIntussusception (Tender mass and red-currant stools)Typhlitis (neutropaenic child) CHILDREN…

APPENDICITIS

Differential Diagnosis


If the diagnosis is apparent from the history, examination and lab findings – then surgery is indicated without imaging.Imaging is reserved for doubtful diagnosis A SHORT NOTE…

APPENDICITIS

Imaging


Faecolith (5-8%) Gas in the appendix Localised paralytic ileus Loss of caecal shadow Blurring of R Psoas R scoliosis of lumbar spine Free air (rare)
PLAIN RADIOGRAPHS…

APPENDICITIS

Imaging


Study of 821 patients… no x-ray was sensitive or specific Use to rule out other condition (obstruction, renal calculus, perforation)Overall – not cost effective PLAIN RADIOGRAPHS… Rao PM, Rhea JT, Rao JA, Conn AK. Plain abdominal radiography in clinically suspected appendicitis: diagnostic yield, resource use, and comparison with CT. Am J Emerg Med 1999;17:325-8.

APPENDICITIS

Imaging


Deutsch and Leopold visualised appendix in 1981 Graded pressure technique (compresses the bowel overlying the appendix) Immobile, non-compressible, blind-ending structure consisting of an anechoic lumen surrounded by an echogenic mucosa and hypoechoic thickened wall adjacent to the caecum.
ULTRASOUND
Deutsch A, Leopold GR. Ultrasonic demonstration of the inflamed appendix: case report. Radiology 1981;140:163-4.

APPENDICITIS

Imaging

The diagnostic accuracy of graded compression ultrasound has been reported to range from 71% to 97%, with sensitivities and specificities in the 76% to 96% and 47% to 94% ranges, respectively Operator dependent Normal appendix must be visualised to rule out appendicitis (60-82%) Retrocaecal appendix difficult to visualise

ULTRASOUND

APPENDICITIS

Imaging

Appendicitis features – Appendiceal diameter > 6-7mm (sensitivity 100%, specificity 64%)Target signLoculated peri-caecal fluid (rupture)AppendicolithAbsence of gas in appendix lumen ULTRASOUND

APPENDICITIS

Imaging


Disadvantages…Low specificityDiscomfort for patient with probe pressureAdvantages…InexpensiveNon-invasiveNo radiationCan find other abdominal pathology ULTRASOUND - summary

APPENDICITIS

Imaging


Accuracy of 93-98% Sensitivity 87-100% Specificity 95-99% Enlarged appendix Appendiceal wall thickening Peri-appendiceal fat stranding Appendiceal wall enhancement
CT SCAN… Rao PM, Rhea JT, Novelline RA. Sensitivity and specificity of the individual CT signs of appendicitis: experience with 200 helical appendiceal CT examinations. J Comput Assist Tomogr 1997;21:686-92.

APPENDICITIS

Imaging



Study of 908 patients…Drop in perforation rate (22% to 14%)Drop in negative appendectomy rate (20% to 7%) CT SCAN… Rao P, Rhea JT, Rattner DW, Wenus LG, Novelline RA. Introduction of appendiceal CT: impact on negative appendectomy and appendiceal perforation rates. Ann Surg 1999;229:344-9. .

APPENDICITIS

Imaging


CT advantages… Higher diagnostic accuracyOperator independenceCT DisadvantagesContrast problemsRadiationCost CT vs. ULTRASOUND…

APPENDICITIS

Imaging


Large meta-analysis of 9576 patients Proven to prevent wound infection and intra-abdominal abscess Cover Gram negative and anaerobic organisms
Andersen BR, Kallehave FL, Andersen HK. Antibiotics versus placebo for prevention of postoperative infection after appendicectomy. Cochrane Database Syst Rev 2004;4:1-64

APPENDICITIS

Antibiotics

Generally indicated unless…Symptoms resolved when patient presentsPeri-appendiceal abscess without peritonitis – percutaneous drainageInterval appendectomyOptimise patient before surgery

APPENDICITIS

Surgery


Normal appendix?Check Caecum, ileum (and sigmoid) for diverticular disease. Check for Meckel’s Gall BladderIiflammatory Bowel DiseasePerforated Duodenal UlcerGUT (females – PID, follicular cysts, ectopic)Mesenteric lymphadenpathyNB – if ++ pus, full exploration required

APPENDICITIS

Open Appendectomy



Normal appendix?Do appendectomy anyway (presence of the scar, etc.)Exception is diseased caecum (e.g. Crohn’s) where a fecal fistula may form

APPENDICITIS

Open Appendectomy


CT or Sonar guided percutaneous catheter7-10 days of drainageInterval appendectomy at 6-8 weeksIf laparotomy done…Open abscessAppendectomy only if safeIf caecum friable, leave it and do interval appendectomy (10% to 80% risk of recurrence)

APPENDICITIS

Peri-appendiceal Abscess


Kurt Semm 1983 Major meta-analysis, still major controversy Dependent on expertise and equipment Allows for better visualisation of the abdomen

APPENDICITIS

Laparoscopic Appendectomy


Lack of surgeon’s experienceInability to tolerate GARefractory coagulopathyDiffuse peritonitis with haemodynamic compromisePrevious abdominal surgery (relative)Portal Hypertension (relative)Advanced pregnancy (relative)Severe cardiac failure (relative) CONTRA-INDICATIONS…

APPENDICITIS

Laparoscopic Appendectomy


2.8
2.6
6.5
58
68
86
167
Ortega et al (1995)
4.8
3.4
8.3
45
55
104
106
Macarulla et al (1997)
1.2
1.1
7.4
67
82
23
27
Minne et al (1997)
3.2
3.5
0
25
51
42
42
Reiertsen et al (1997)
4
3
0
31
35
82
87
Klinger et al. (1998)
2
2
5.3
41
31
21
19
Heikkinen et al (1998)
2
2
12
35
60
256
244
Hellberg et al (1999)
3.7
1.6
— 38
28
35
35
Ozmen et al (1999)
2
2
23
40
60
301
282
Pedersen et al (2001)
3.4
2.6
16
91
107
105
93
Long et al (2002)
0
L
O
L
0
L
OR Time Conversion rate(%) LOS
number
Reference

Selected randomized trials of laparoscopic versus open appendectomy

Laparoscopic longer by 15-20 minutes5% - 25% conversionHospital stay same or 1 day in favour of laparoscopicReturn to normal activity 5-7 days earlierResults of complication rates mixedNo difference in cost (equipment/length vs. hospital stay)‘Jury is still out

APPENDICITIS

Laparoscopic Appendectomy