Laparoscopic Cholecystectomy: Step-by-Step with Calot's Triangle & Critical View of Safety

Step 1 — Patient Positioning & Setup

• Position: Supine, one arm tucked (to allow intraoperative cholangiogram access if needed)
• Bed: Patient well secured for steep reverse-Trendelenburg positioning — gravity drops bowel away from the operative field
• Prep/drape: Lower chest to abdomen, prepared to accommodate conversion to open if needed
• An orogastric tube decompresses the stomach for better upper-abdominal visualization

Step 2 — Port Placement (Standard 4-Port Configuration)

Port diagram: 12-mm periumbilical camera port + three 5-mm working ports (right anterior axillary line, right midclavicular line, subxiphoid).

Step 3 — Gallbladder Retraction & Exposure

• The lateral port grasper elevates the fundus cephalad toward the right shoulder — this opens the porta hepatis and stretches the cystic structures
• The midclavicular port grasper retracts the infundibulum/Hartmann's pouch inferolaterally — this is the key maneuver that unfolds the triangle of Calot and puts the cystic duct under tension
• If the gallbladder is tense/distended (acute cholecystitis), decompression via needle aspiration through the fundus is performed first
• Adjacent structures (omentum, duodenum, colon) that are adherent to the gallbladder are gently peeled off bluntly in a plane parallel to the gallbladder wall

Step 4 — Anatomy of Calot's Triangle

Step 5 — Dissection of the Hepatocystic Triangle

• Using a Maryland dissector or hook, the peritoneum overlying both the anterior and posterior aspects of the hepatocystic triangle is scored and dissected
• The fibrofatty and areolar tissue within the triangle is cleared away
• Dissection is kept high on the gallbladder wall (at the infundibulum), not deep into the porta hepatis
• The goal is to skeletonize the two structures that enter the gallbladder: the cystic duct and cystic artery

Step 6 — Critical View of Safety (CVS)

Three criteria — ALL must be met simultaneously:

"Critical view of safety is defined as two and only two structures entering the gallbladder, the lower third of the gallbladder dissected from the liver to expose cystic plate, and a cleared hepatocystic triangle." — Sabiston Textbook of Surgery, p. 1839

Labels: (1) Hepatocystic triangle cleared, (2) Cystic plate exposed, (3) Two structures entering gallbladder.

Window A = space between cystic duct (inferiorly) and cystic artery (superiorly). Window B = space between cystic artery and liver bed.

Step 7 — Clipping and Division

1. A clip applier places 2 clips proximally (toward the patient — away from gallbladder) and 1 clip distally on the cystic duct, then transects between
2. Similarly, 2 proximal + 1 distal clip on the cystic artery, then transected
3. Key technical tip: ensure both jaws of the clip applier are fully visible before closing — prevents incomplete occlusion

Step 8 — Gallbladder Dissection from Liver Bed

• The gallbladder is dissected off the cystic plate (liver bed) using electrocautery (hook or spatula)
• Dissection proceeds from infundibulum toward fundus in a "top-down" (retrograde) manner
• Venous drainage from the gallbladder goes directly into the liver bed through venules — meticulous hemostasis is required
• Just before completing fundic dissection, the clip sites on the cystic duct and artery are re-inspected (the superior traction of the fundus at this stage provides an excellent final view of the porta hepatis)

Step 9 — Specimen Retrieval & Closure

• The gallbladder is placed into a specimen retrieval bag inside the abdomen
• Extracted through the umbilical (12-mm) port, enlarged if needed
• Any spilled stones must be retrieved — left-behind stones can cause late perihepatic abscess
• Ports are removed under vision, pneumoperitoneum deflated, fascia closed at the 12-mm site, skin closed

Adjuncts: When Anatomy Is Uncertain

Bailout Strategies When CVS Cannot Be Achieved

• Subtotal cholecystectomy — partial resection leaving the posterior wall adherent to the liver; cystic duct orifice closed from within
• Fundus-first (dome-down) approach — dissect from fundus toward infundibulum when the neck is too inflamed
• Cholecystostomy tube — drain first, operate electively 6–8 weeks later