DESCRIBE AN OPERATION – APPENDICECTOMY Valerie See 29 th September 2014

EMBRYOLOGY AND ANATOMY Appendix

Embryology 8 th week gestation Narrow diverticulum of the caecal bud Caecum descends from RUQ to RLQ with development of lateral wall > medial wall Appendix base lies at the posteromedial wall of the caecum Langman’s Medical Embrology 9 th Ed.

Anatomy Blind-ending tube of variable length True diverticulum of the caecum Externally: Base identified by convergence of 3 taenia coli -> longitudinal muscular layer Surface anatomy: McBurney’s point = 1/3 rd along the line from R) ASIS to umbilicus Appendix tip – variable Retrocaecal (or retrocolic) and intraperitoneal (most common) Subcaecal, pre-ileal, post-ileal, pelvic Retroperitoneal

Mesoappendix – triangular fold of peritoneum Contains appendicular a. Blood supply: appendicular a. – branch of posterior caecal a. – terminal branch of ileocolic a. (corresponding vv.) Lymphatic drainage: nodes assoc. with ileocolic a.

Zollinger’s Atlas of Surgical Operations 9 th Ed.

APPENDICECTOMY

Acute Appendicitis Appendicitis = inflammation of the vermiform appendix Epidemiology Peak incidence between 2 nd -3 rd decade Rare in infants Lifetime incidence in Male: female = 8.6: 6.7 Pathogenesis Aetiology ? Luminal obstruction ↑ luminal and intramural pressure Thrombosis and occlusion of small vessels with lymphatic stasis Localised ischaemia and necrosis Bacterial overgrowth

Pre-operative Preparation IV fluids +/- IDC IV antibiotics – gram negative bacilli and anaerobic cocci Anti-pyrexials DVT prophylaxis

LAPAROSCOPIC APPENDICECTOMY

Position and Preparation Position Patient: Supine Right arm extended Left arm at patient’s side General anaesthesia with endotracheal intubation Surgeon and assistant: Left side of patient Equipment Laparoscopic tower – fibreoptic light cable, gas tubing – to head of table Video monitor – across from operating team Electrocautery and suction irrigator – toward foot of table Scrub nurse and Mayo instrument tray – toward foot of table Preparation Empty bladder – Foley catheter Abdomen is prepared with an appropriate anti-septic solution

Incision 3 port insertion Umbilicus (videoscope port) Vertical or transverse skin incision just above or below umbilicus Open Hasson technique Pneumoperitoneum established 2 x 5mm ports under direct vision (+/- infiltration with LA) Left lower quadrant Midline suprapubic Patient is re-positioned Trendelenberg’s position Rotated right side up Diagnostic laparoscopy – 4 quadrant examination

Procedure Visualisation of the appendix and its mesentry Conversion to open if unable to visualise the appendix, mesoappendix and base of the caecum Laparoscopic removal of the appendix Appendix tip grasped with atraumatic forceps and lifted toward abdominal wall Window created in mesoappendix – dissecting forceps or diathermy Appendicular vessels coagulated or ligated using clip applicator (endovascular linear stapler) Appendix base cleared of surrounding tissue Appendix base divided above absorbable loop ligature or using an endoscopic cutting linear stapler

Closure Ports are removed under vision Abdomen decompressed and Hasson port removed Fascial defect closed with figure-of-eight sutures using 0 absorbable sutures Skin closed with subcuticular absorbable sutures

OPEN APPENDICECTOMY

Position and Preparation Position Supine General anaesthesia with endotracheal intubation Preparation Abdomen is prepared with an appropriate anti-septic solution

Incision and Exposure Tranvserse skin incision at McBurney’s point External oblique fascia opened along line of fibres Internal oblique and transversus adominis mm. fibres identified and split Peritoneum is grasped and a small incision made

Procedure Caecum is delivered into the wound Appendix identified and grasped with a Babcock clamp Small window created in mesoappendix Vessels ligated Appendix base crushed with a clamp and ligated using 2- 0 absorbable suture -> transected with a scalpel Appendiceal stump may be inverted using a purse-string suture

Closure Peritoneum – 3-0 continuous absorbable suture Transversus and internal oblique mm. – 2-0 absorbable sutures External oblique fascia – continuous 0-0 absorbable suture Skin – subcuticular suture or staples

Zollinger’s Atlas of Surgical Operations 9 th Ed.