30 µm – When a needle begins with a surgeon's request

From needles that were never meant for surgery

The story of KONO SEISAKUSHO – the Crownjun brand – begins in Ichikawa, Chiba, Japan. The company was founded in February 1949 to make needles for measuring instruments. In September 1964 it entered the field of medical devices [4].

Years later, that skill in making very small things met a new request. Not from a product plan. From a surgeon.

“Can you make a needle even smaller?”

In April 2004, a hand surgeon at Teikyo University asked KONO SEISAKUSHO for a needle finer than 80 µm – already the smallest the company could make [2].

Behind the request was a very specific clinical need. According to Crownjun, the demand for finer needles came from strong requests by doctors, particularly for young patients and patients with rare diseases [3].

For a suture needle, size is more than a number. The thicker the needle, the larger the hole it leaves and the more likely bleeding at the needle hole becomes [2]. So “can it be smaller?” became a problem that surgeons placed in the hands of engineers.

When 80 µm was not the final limit

At the time, KONO SEISAKUSHO did not have machinery precise enough to make the needle the surgeon wanted [3]. But making an ultra-fine needle was never only about machines.

One of the greatest difficulties was choosing the material. Then came another challenge: how to attach the thread to such a tiny needle. The company went through many rounds of trial and error [3].

A request from the operating room became an engineering problem. The engineering problem was tested, adjusted and tested again. And in April 2004, the 30 µm needle – 0.03 mm – was launched [4].

A needle 0.8 mm long

In the Crownjun catalogue, code NDH00Y is a needle 0.8 mm long and 30 µm in diameter, with 12-0S suture. The thread is monofilament polyamide 6.6. According to the catalogue, size 12-0S is used for vessels of 0.1–0.3 mm [1, 2, 5].

Crownjun describes these as “the smallest suture needles in the world” [1]. This is Crownjun's statement about the needle, not about the diameter of the thread.

Behind the 30 µm figure lies another story: a clinical need that was listened to and turned into a precise engineering requirement.

When surgeons and engineers start from the same idea

The 30 µm story reflects KONO SEISAKUSHO's philosophy of medical–engineering cooperation: listening to surgeons' ideas [1]. A surgeon sees what is missing in practice. A manufacturer takes up the request. Then materials, engineering and trial and error are placed on the same journey.

Until, in the end, an idea from a surgeon becomes a needle just 0.03 mm across.

MGI Medical is the exclusive distributor of CROWNJUN Nylon microsurgical and supermicrosurgical sutures in Vietnam. Product: CROWNJUN Nylon microsurgical and supermicrosurgical suture · Brand: Crownjun (KONO SEISAKUSHO CO., LTD) · Origin: Japan.

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