Evolution Of Trocar Needles in Laparoscopic And Endoscopic Minimally Invasive Surgery

From Veress to Optical Trocars in Reducing Punctures/Port Placements

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Although the phrase "reducing core passes" is mostly seen in the biopsy field, the core value of trocars in minimally invasive surgery (laparoscopy/arthroscopy/endoscopy) similarly manifests as reducing the number of puncture (port placement) operations. By placing a trocar cannula with a sealing cap in a single insertion to establish a working channel, scopes, graspers, scissors, and suture devices can be repeatedly introduced and removed without making new incisions for each step-this shares the same philosophy as the coaxial biopsy trocar's "one puncture, multiple samples."

Classic laparoscopy first uses a Veress needle to establish CO₂ pneumoperitoneum, then punctures the abdomen with a bladed or bladeless trocar of 5 mm/10 mm/12 mm diameter. The modern trend favors optical trocars, whose obturator features a transparent conical tip that connects to a camera for direct visualization of layer-by-layer abdominal wall penetration. This markedly reduces accidental vascular/organ injury and often eliminates the need for a preliminary Veress step, compressing the total operational steps of establishing pneumoperitoneum and exploration. Arthroscopy (shoulder/knee/wrist) uses fine-diameter trocars (2–4 mm) to first establish irrigation-drainage channels before exchanging for working sheaths, likewise conforming to the "reduced operation" logic.

In endoscopy, translumenal endoscopic surgery (NOTES) and EUS-guided FNA/biopsy have transplanted the coaxial trocar concept into "rapid-exchange trocar sheaths"-19G/22G FNA needles incorporate a trocar-style occluding stylet to prevent lumen blockage. After puncturing the lesion, the stylet is withdrawn to apply negative pressure for cytological aspiration or to advance a micro-biopsy forceps through the outer sheath for tissue core sampling, all without repeatedly traversing the full thickness of the gastrointestinal wall, thereby lowering perforation risk and reducing operation counts.

It is worth noting that reducing operation counts directly correlates with complication rates: studies show optical trocars reduce major vascular injury rates from 0.3% to <0.1% compared to blind puncture; coaxial biopsy trocars reduce bleeding and needle tract seeding as previously described. For equipment departments and distributors, distinguishing between "surgical trocars (with valve seals, reusable/single-use)" and "biopsy coaxial trocars (thin-walled, valveless, paired with standard biopsy needles)" is crucial-their diameter labeling systems (French vs. Gauge), length specifications, and sterilization methods differ, and confusion leads to clinical complaints. Future directions include integrated pressure sensing to prevent over-penetration, biodegradable coatings to reduce adhesions, and robotic-assisted trocar positioning systems, further advancing "operation count reduction" toward intelligence and standardization.