Minimally Invasive and Operative Technique
This domain tests laparoscopic physiology, instrument and energy-device choice, robotic principles and intraoperative judgement. Many questions describe an unexpected event during laparoscopy and ask for the immediate response.
Laparoscopic access and pneumoperitoneum
- Access by Veress needle (blind) or Hasson open technique; the open technique is preferred in previous laparotomy and adhesions.
- Carbon dioxide insufflation to 12–15 mmHg; CO2 is used because it is non-flammable and highly soluble, reducing the risk of embolism.
- Physiological effects: hypercapnia and respiratory acidosis, reduced venous return, raised systemic vascular resistance, raised intracranial pressure, diaphragmatic splinting and atelectasis.
- Vagal bradycardia and hypotension during insufflation are treated by desufflation, deepening anaesthesia and atropine if needed.
- Trendelenburg position improves pelvic views but raises intracranial and intraocular pressure; reverse Trendelenburg is used for upper abdominal work.
Instruments and energy devices
- Monopolar diathermy uses the patient as the return electrode, with risk of direct and capacitive coupling burns; bipolar confines current between forceps and is safer near bowel and nerves.
- Ultrasonic and advanced bipolar vessel-sealing devices coagulate and cut with limited thermal spread; they are useful near the ureter and bile duct.
- Staplers, clips and loop ligatures each have a defined role; know the staple height and the need to check the anvil.
- The 30-degree scope improves angled views of the hiatus and pelvis.
Robotic and advanced techniques
- Robotic platforms offer three-dimensional vision, tremor filtration, articulated instruments and better ergonomics; they lack haptic feedback, so visual cues replace touch.
- Disadvantages: cost, setup time, training requirements and access limitations.
- Conversion to open is a sound intraoperative decision, not a complication; document the reason.
- Safe cholecystectomy relies on achieving the critical view of safety before clipping any structure.
Worked example
During laparoscopic cholecystectomy, the patient becomes bradycardic at 40 beats/min with a fall in blood pressure soon after insufflation. This is a vagal response to peritoneal stretch. Desufflate, inform anaesthesia, deepen anaesthesia and give atropine if bradycardia persists; do not proceed to open conversion for this alone.
Traps that lose marks
Continuing dissection without the critical view of safety; using monopolar energy close to the bowel serosa; ignoring rising end-tidal CO2 as a sign of CO2 embolism; treating conversion as failure.