General Principles of Laparoscopic Abdominal Surgery Carlos Cabalag

Presentation Outline Background Patient Selection and Preparation Historical perspective Laparascopy in general surgery Patient Selection and Preparation Pre-operative Preparation Basic equipment Patient Positioning Anaesthetic Issues Access and Port Placement Complications of Laparascopic Surgery General Post-operative Care Summary

Background Lapro (the flank) + skopein (to examine) Use of speculum-type intracorporeal viewing devices from the Greco-Roman period (Hippocrates 460 – 377 BCE). Light transmission and optical clarity was a limitation. Major breakthrough – Thomas Edison incandescent bulb and 3-lens optical system by Nitze and Reinecke (1879) First performed by George Kelling Germany in a dog (1901) First performed in humans by Hans Christian Jacobaeus thoracoscopy in humans (1910)

Advantages Rapid recovery time Minimal immune response Minimal scar tissue formation Decreased post-operative pain Reduction in the incidence of post-op ileus Early mobilisation

Contraindications Absolute (rare): Relative: Unfit for general anaesthesia Pregnancy Relative: Severe ischaemic or valvular heart disease Increased intracranial pressure Hypovolemia / shock

Patient Selection and Preparation Preoperative Evaluation: Cardiopulmonary disease Specific factors: Prior incisions, umbilical abnormalities, positioning limitations, ascites, Hx of DVT Preparation: Pre-op antibiotics DVT prophylaxis Premedication CV and respiratory systems review are ESSENTIAL because of the potential effects of pneumoperitoneum and patient positioning. Morbidly obese patients also need to be r/v by the anaesthetist due to increased risk of respiratory failure. Premedications usually not necessary unless patient is very anxious – e.g. with benzos. Otherwise H2 blockers or PPIs given to patients with increased risk of aspiration (e.g. hiatus hernia and obesity) as studies have shown, decreased the risk of pneumonitis if aspiration occurs.

Pre-operative Preparation Basic equipment: Insufflation device Imaging system Irrigation/aspiration unit Electrocautery unit

The ‘Insufflator’

Patient positioning Trendelenburg position (head down) usually for gynaecological procedures or Reverse trendelenburg (head up) for upper GI surgery. Trendelenburg: Greater respiratory effects including further reduction in FRC, more V/Q mismatch and greater risk of atelactasis. Initial increase in VR may not be tolerated in patients with compromised myocardial compliance. Reverse Trendelenburg: More marked effects on CV system due to decreased VR and CO therefore low BP. 3 most common patient positions: supine – for majority of procedures including cholecystectomy, appendectomy, gastric small bowel, colonic and vascular proceures. Modified lithotomy position used for procedures in pelvis. Allen stirrups used to hold leg in position. Lateral decubitus position most often used for splenectomy, adrenalectomy and thoracoscopic procedures.

Access and Port Placement Laparoscopic trochar has two components an inner obturator to facilitate entry – sharp cutting edge and an outer sheath by which instruments can pass through. Outer sheath contains a valve or membrane through which instruments may be introduced without loss of pneumoperitoneum. Hasson’s trochar –used to achieve pneumoperitoneum via the open technique. Closed technique via the use of a Veress needle through the umbilicus is rarely used due to its risk of injury to bowel major blood vessels and bladder. Open technique – “mini-laparotomy” – under vision. Vertical or semi-lunar incision made inferior or superior umbilical fold. S/c tissues separated by blunt dissection down to linea alba. Kocher clamps placed on two lateral edges and retracted. Peritoneum can be entered via blunt or sharp dissection. Finger inserted through incision to sweep any surrounding adhesions/bowel.

Access and Port Placement Umbilicus is the primary port for the camera and initial insufflation for pneumoperitoneum. It is often located directly above or cephalad to the aortic bifurcation and also consistently located cephalad to where the left common iliac vein crosses the midline. Aortic bifurcation is located more caudal if the patient is in the Trendelenburg position. Distance of aorta from umbilicus ranges from 0.1 cm in thin patients to 2.7 cm in obese patients. Trocar injuries to the abdominal viscera occur if the viscera are unusually close to the point of insertion such as in thin patients and those patients with prior incisions such as midline incisions and suprapubic tranverse incisions. Adhesions may contain sections of bowel closer to the surface. To avoid this, surgeon usually raises the abdominal wall at the umbilicus with towel clips.

Anaesthetic Issues Effects of pneumoperitoneum Heat loss Haemodynamic changes Respiratory changes Heat loss End-organ perfusion ↓ circulatory support to intra-abdominal organs ↓ renal f(x) and urine output Neurological Pneumoperitoneum: Decreases preload and CO Inc. HR, MAP, SVR, Pulmonary resistance (All secondary to stimulation of vasopressin and RAAS) Significant reduction in cardiac index is seen with intra-abdominal pressures > 12 mmHg. Higher increases and impair diaphragmatic movement in respiration, impairing ventilation and also increasing risk of PE. Use of CO2 causes hypercapnia and respiratory acidosis (due to CO2 reabsorption into circulation) Incr. intrathoracic pressure, decrease in thoracic wall compliance and incr. in airway resistance + bibasal atelactasis  increasing physiological dead space and causes ventilation-perfusion mismatch. (Use of PEEP to help gas exchange) Heat loss: End-organ perfusion: Decreased circulatory support to intra-abdominal organs overall Compression of renal parenchyma + renal vessels  activates RAAS  renal vasoconstriciton. Decr. Circulation in hepatoportal system  LFTs may be deranged post-op esp. with prolonged operations Neurological: ICP increase + decrease in cerebral perfusion pressure (CPP) especially if decr. CO

Complications Visceral organs – most common is small bowel followed by colon and bladder injuries. Most injuries to the SB and colon can go significantly unrecognized for > 24 hours and there is a huge mortality, up to 26% in some cases, from secondary faeculent peritonitis and subsequent sepsis. One case series in America identified 13% of deaths occurring from visceral injury. Vascular injury -

Complications Structural injuries Gas embolism ( < 0.6%) Vascular (epigastric vessels > greater omentum) Visceral (Small bowel > Large bowel > Liver) Gas embolism ( < 0.6%) Pneumothorax/mediastinum/pericardium More common in upper-GI surgery Fever and/or abdominal tenderness may be the first signs of bowel perforation. Gas embolism: Suspect when decr. End tidal CO2, drop in SpO2 or CO or if fatal ECG changes Can occur through direct puncture of vessel with Veress needle or Trocar (importance of minimal flow rate to achieve pneumoperitoneum). Intraoperative injury Rare: Increase intrabdominal gas pressure. Things that can increase intraabdominal gas pressure: Laser: 1 to 5L/min Argon (electrosurgery): 0.5 to 3L/min Tissue glue: 3 to 10L/min Irrigation: 0.5 to 5L/min Use of CO2 minimises gas embolism. Must inject 2 ml/kg/min of CO2 to cause fatal effects. Mx: STOP – Trendelenburg with left lateral tilt (limit gas flow from R) ventricle to pulm. Circulation)  Stop N20 100% O2 ventilation if no effect, CVC to aspirate gas.

Post-operative Care PONV (↑ incidence) Incisional pain Shoulder pain Ondansetron and other serotonin-receptor antagonists Dexamethasone 5 – 10 mg as a prophylactic Incisional pain > 3 days need to consider infection/hernia Shoulder pain Post-operative hydroceles Post-laparoscopic hernia repairs and pelvic LN dissections. Increased incidence of post-operative nausea and vomiting due to gastric stasis, distension and the effects of the pneumoperitoneum itself. Incisional pain > 3 days (generally speaking) consider hernias for incisional sites > 10 mm, especially in obese patients. Other considerations: bowel obstruction, perforation, intra-abdominal abscess or incarcerated hernia Shoulder pain: CO2 gas does not get completely released from peritoneal cavity. Takes days to get reabsorbed. As patient recovers, irritates diaphragm and gets shoulder tip pain (Kerr’s sign) Hydroceles – scrotal accumulations of irrigating fluid and hematoma from the procedure itself may not be noticeable until the patient is ambulatory. Typically, echymosis and swelling of scrotum and base of penis on Day 2 post-op. Quite uncomfortable. But if massive and increasing pain, need surgical evacuation.

In Summary Advantages of laparoscopic surgery Special considerations in pre-operative workup Post-operative Cx and considerations

References Bhayrul S, Vierra MA. “Trocar injuries in laparoscopic surgery. J Am Coll Surg. 2001; 192: 677-83 Buunen M. “Stress response to laparoscopic surgery.” Surg Endosc. 2004; 18:1022-28. Chandler JG. “Three spectra of laparoscopic entry access injuries.” J Am Coll Surg. 2001; 192:478-90 Gutt CN. “Fewer adhesions induced by laparoscopic surgery?” Surg Endosc. 2004; 18: 898-906 Jones, DB. “Laparoscopic Surgery: Principles and Procedures.” 2nd edition. 2004. Novitsky YW. “The net immunlogic advantage of laparoscopic surgery.” Surg Endosc. 2004; 18: 1411-19

Room Setup Radiological unit (optional) Laparascopic unit Anaesthetic unit Laparascopic unit – extra monitors Instrument table Electrocautery Operating table