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In acupuncture practice, inserting a long needle (with its shaft measuring 40 mm or more) by only holding the needle handle without touching the shaft represents a significant challenge. The long fine needle shaft can easily bend (also known as ‘buckle’) during insertion. Although one may use a guide tube or a needle inserter to help the initial insertion, buckling will still occur when advancing the needle in soft tissue to reach the depth required for therapeutic effect. In a recent study we reported that the buckling of the acupuncture needle could be significantly reduced by changing the design of its handle.1 However, as shown in figure 1A–C, it is impossible to prevent long needles from buckling by simply having a stiffer handle, even after using conventional guide tubes for the initial insertion. Consequently, some clinicians use the other hand to hold the lower part of the needle shaft to assist further insertion. However, this approach would violate the guidelines for clean and safe clinical practice of acupuncture stipulated by the WHO, the Chinese Medicine Board of Australia and other professional bodies.2–5
There have been previous attempts to solve the buckling problem, a notable example being the invention of a ‘puncturing guidance tube’.6 This consists of a cylindrical body with two parts of different diameters. The upper portion has a large diameter with a funnel-shaped rim at the top which allows the needle to be put through easily. The lower portion, with a small diameter, is to prevent the needle from buckling during insertion. However, such a complex device would be expensive for single use and unhygienic for multiple applications.
As a follow-up to our recent investigations on commonly used acupuncture needles,1 ,7 we aim to propose and demonstrate a simple method for preventing long acupuncture needles from buckling and contamination during insertion. The new method can be implemented easily and inexpensively as it will only involve a slight modification to the widely used rigid plastic guide tube shown in figure 1D.
We took three commonly used types of sterile single-use acupuncture needles, all with shafts made of stainless steel. The main difference among these needles was in the handles. The first type was the Hwato needle (Suzhou Medical Appliance Factory, Suzhou, China) with a flexible copper coil handle (figure 1A), the second was the J-type Seirin needle (Seirin Corporation, Shizuoka, Japan) with a less flexible plastic handle (figure 1B) and the third was the L-type Seirin needle (Seirin Corporation) with a relatively stiff stainless steel handle (figure 1C). All the needles had the same nominal shaft diameter of 0.25 mm and shaft length of 60 mm. To simulate human tissue for needle insertion we used multilayered foam (Padject, Sydney, Australia) which was designed to simulate the human tissue (skin, fat and muscle) and is used by nursing students to practise needle injection techniques.
For the purpose of demonstrating the feasibility and effectiveness of the proposed concept of having a deformable guide tube, we used a plastic straw attached to a soft drink carton (Chrysanthemum Tea Drink, Vitasoy International Holdings, Hong Kong). As shown in figure 2, such a straw is similar to the conventional guide tube, the main difference being in the thickness of the tube wall. The walls of conventional guide tubes from Hwato and Seirin range from 0.50 to 0.75 mm, while that of the plastic straw was around 0.25 mm. So, while conventional guide tubes are quite rigid, the plastic straw could be easily compressed laterally.
By squeezing the guide tube (plastic straw) firmly as shown in figure 2C, a needle of any length can be gripped and advanced in the tissue without either buckling or becoming contaminated. The guide tube should, of course, be lifted off the skin before being squeezed.
For a deformable guide tube to be effective it must satisfy three requirements: (1) it should be transparent (like most existing guide tubes) so that the clinician can clearly see the needle inside the tube and estimate how far the needle has penetrated into the tissue; (2) it must be sufficiently flexible to be compressed easily from side to side; and (3) it should not be too flexible—it must be stiff enough to remain straight when the needle is tapped from the top for the initial insertion (figure 2B). The thin-walled plastic straw shown in figure 2 is only one example of various possible deformable tubes that would satisfy these requirements. A drawback of the present thin-walled plastic straw is the sharp edge at the bottom of the tube which might cause patient discomfort. To overcome this problem, one could also consider using other deformable materials (such as rubber) of appropriate hardness. The deformable guide tubes should of course be sterilised, like the conventional guide tubes.
Alternatively, a clinician could put a cotton ball, swab or other clean material around the needle to support it while advancing it, but using a deformable guide tube would be more convenient and straightforward.
We believe your readers will be interested in this idea of a deformable guide tube as a new and simple method for preventing long acupuncture needles from buckling and becoming contaminated during insertion. We recommend that needle manufacturers could readily implement the proposed device by simply reducing the thickness or modifying the hardness of current guide tubes.
Contributors YMX and CSZ initiated the research, designed and conducted the experiments, and drafted the manuscript. ALZ and CCX provided critical comments and contributed to the revision of the draft. All authors read and approved the final manuscript.
Competing interests None.
Provenance and peer review Not commissioned; internally peer reviewed.
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