A.      SKIN

B.       SUPERFICIAL FATTY LAYER OF CAMPER

C.       SUPERFICIAL FIBROUS LAYER OF SCARPA

D.       EXTERNAL OBLIQUE APONEUROSIS

E.       INTERNAL OBLIQUE MUSCLE

F.       TRANSVERSE ABDOMINIS MUSCLE

G.     TRANSVERSALIS FASCIA

H.      EXTRA PERITONEAL FAT

I.        PARIETAL PERITONEUM

Ideally in this age group I would perform diagnostic laparoscopy as clinical diagnosis of acute appendicitis is incorrect in about 30 to 45 % of young females as gynaecological causes of right iliac fossa pain are more common. If acute appendicitis is confirmed, depending upon surgeons preference, appendicectomy can be performed laparoscopically or the procedure converted to an open appendicectomy.

Informed consent should be obtained before the procedure, warning her specifically that she will end up with a scar. She should be told of risks of infection and of the possibility that the appendix might be normal.

Patient is positioned supine under general anaesthesia with an endotracheal tube. Abdomen is prepared with povidone iodine from umbilicus to pubis and draped to expose right lower quadrant involving right ASIS, umbilicus and midline.

Skin is incised using a lanz incision centred on a point about two thirds of the way from the umbilicus to right ASIS. Subcutaneous fat and scarpas fascia is divided down to external oblique aponeurosis. The external oblique is opened in line of its fibres and muscle layers (internal oblique and transversus abdominis) are split using straight Mayo scissors to expose the peritoneum. Peritoneum is picked between two clips and after ensuring that there is nothing stuck to it, peritoneum is opened with a knife and the opening is extended with scissors.

If pus is evident a culture swab is taken for microbiological assessment. Specimen of peritoneal fluid is taken for microbiological culture.