Laparoscopic surgery is known as "keyhole surgery", which relies on tiny incisions to set up working accesses. As the primary instrument for this purpose, trocars determine surgical smoothness, patient safety and postoperative recovery quality.

I. Basic Structure and Classification of Trocars

A trocar consists of two core components: a sharp inner obturator and an outer hollow cannula. The obturator penetrates the abdominal wall, while the cannula remains indwelling as a passage for endoscopic instruments after the obturator is removed. By tip design, trocars are divided into conical, pyramidal and blunt types. Based on safety lock mechanisms, there are spring-shielded and push-pull safety styles. Spring-protected trocars are the most widely used clinically: once the tip enters the peritoneal cavity, a spring automatically extends a shield to cover the sharp obturator and prevent visceral laceration.

II. Standard Operating Steps in Laparoscopic Procedures

• Preoperative preparation and patient positioning The patient is placed supine under general anesthesia, followed by routine skin disinfection and sterile draping. Surgeons mark puncture sites according to surgical demands; the periumbilical area is the primary entry point, with alternative sites along the lateral edge of the rectus abdominis. The bladder is emptied preoperatively, and a gastric tube is placed if needed to relieve gastric distension.
• Pneumoperitoneum establishment A 10–12 mm small incision is made at the umbilicus. A Veress needle is inserted into the peritoneal cavity; after correct positioning is confirmed, carbon dioxide is insufflated to stabilize intra-abdominal pressure at 12–15 mmHg. Distension lifts the abdominal wall away from viscera for safe trocar penetration.
• Primary trocar insertion (first access, critical step) One hand elevates the abdominal wall manually or with lifting retractors; the other grips the trocar and advances it vertically or slightly obliquely with rotating wrist motions. Two distinct "give" sensations mark penetration through fascia first, then peritoneum-advancement stops immediately afterward. The obturator is withdrawn; audible gas outflow verifies intraperitoneal placement. A laparoscope is inserted instantly to inspect for adhesions or hidden injury beneath the puncture site.
• Secondary auxiliary trocar insertion (second, third ports) Additional sites (McBurney's point, subcostal area, etc.) are selected under direct laparoscopic visualization. Small skin cuts are made, then trocars are advanced slowly under real-time monitoring to avoid inferior epigastric arteries, intestines and other vital structures. Obturators are removed, leaving cannulas for graspers, electrocautery hooks and other operative devices.

III. Core Manipulation Skills and Safety Principles

• Puncture technique: Violent stabbing is forbidden. Rotational, wrist-driven advancement leverages cutting geometry of the tip instead of blunt impact. For obese patients with thick abdominal walls, a modest adjustment of insertion angle is allowed, with constant tactile control of tip depth.
• Safety prerequisites: All trocar punctures must follow pneumoperitoneum creation to create safe separation between the wall and internal organs. Patients with prior abdominal surgical scars require port placement far from old incisions, or open Hasson entry to prevent injury to adherent bowel loops.
• Cannula fixation: After successful placement, cannulas are secured to the skin with sutures or dedicated locking fixtures to prevent intraoperative slippage or dislodgement. Sealing valves are checked for intactness to sustain stable pneumoperitoneum without gas leakage.

IV. Common Complications and Management

• Abdominal wall vascular injury: Most often inferior epigastric artery laceration during lateral port placement. Prevention involves transillumination of the abdominal wall under laparoscopy to avoid vascular trajectories; hemostasis is achieved via electrocoagulation or sutured ligation if bleeding occurs.
• Port-site hernia: Fascial defects from trocars ≥10 mm are prone to bowel incarceration if unrepaired. Routine fascial closure is mandatory postoperatively for large-bore ports.
• Visceral perforation: The most severe adverse event, usually caused by dense adhesions or reckless manipulation. Immediate open conversion is required for surgical repair once bowel or hollow organ damage is identified.

Conclusion

Proficiency in trocar handling forms the foundational skill set for laparoscopic surgeons. Mastery of standardized workflows, precise puncture techniques and strict safety protocols is essential training for all minimally invasive practitioners. Disposable safety trocars have become mainstream nowadays, yet clinical judgment, thorough anatomical knowledge and careful operative discipline remain irreplaceable pillars of safe surgery.