JSUR Journal

Background

The microscope has long played an essential equipment for ear surgery. Recently the adaptation of Endoscopic Ear Surgery (EES) has become more popular. Not only does the endoscope provide a wider field of view, but it also allows surgeons to look around corners during surgery, making it more suitable for a small, complex structure such as the ear. Clinical

studies have also shown that the surgical results of EES in various type of otological operations are comparable to those of using a microscope [1-3]. The history of EES can be traced back to three decades ago [4]. Cohen et al. proposed a classification system of three waves on the use of endoscopy in otology [5]. The first wave (Cohen class 1) was about an endoscope used for inspection without dissection. It mainly described the diagnostic and documentary aspects of the endoscope. Nomura demonstrated the use of an endoscope in the examination of the middle ear in 1982. [6] The second wave (Cohen class 2) was mixed dissection, in which an endoscope was used as part of the dissection. Here, the endoscope was used as an aid adjunct to the microscopic removal of the disease. An example of this was Badr-el-Dine, who demonstrated the value of an endoscope in cholesteatoma surgery [7]. The third wave (Cohen class 3) was about ourely endoscopic procedures. It demonstrated the use of an endoscope as the main workhorse for ear surgery.

As early as 1992, Dr. El-Guindy from Egypt had increased the likelyhood of using endoscope in performing myringoplasty [8]. Nowadays, the endoscope is increasingly used for various type of ear surgeries such as cholesteatoma surgery [7], endoscopic tympanoplasty [9], endoscopic stapedotomy, and ossiculoplasty etc. [10, 11].However, EES also has its problems. During EES, the operating surgeon must use one hand to hold the endoscope, which means that only one hand is available to hold the instruments [12]. This inevitably increases the operating time and the risk of possible complications by frequent switching of instruments. Functional endoscopic sinus surgery was introduced earlier than EES and encountered the same obstacles during its development. During FESS, when involves heavy bleeding that impairs vision of the surgeon, or when the tissue needs to be held under tension so that it can be dissected cleanly, it is always best to use both hands. The bimanual technique, involving two trained endoscopists was proposed early on to solve this problem [13].

More recent development is the use of an endoscope holding arm so that only one trained endoscopist is needed during the surgery [14]. However, it is still challenging to develop a holder with sufficient accuracy and effectiveness for use in middle ear surgery [13]. Several endoscopic instruments have been modified for use in ESS meanwhile [15].Surgeons have been using the LASER in microscopic ear surgery for long [16-19]. It has enabled hemostasis and non-contact ablation of tissue. Nowadays, there are also more and more established roles for LASERs in the EES era [20]. Although LASERs are undoubtedly excellent tools in EES, there are many challenges in applying this technique in EES given the fact that only one hand is available. In common practice, the use of smokegenerating devices such as LASER and diathermy requires suction to ensure a good view of the surgical field. Also, minor bleeding might still be encountered during LASER application that prevent the application of further LASERs. Suction is needed during the whole procedure.

But in the situation where one hand is occupied with an endoscope, it is difficult to use LASER and suction at the same time. In single-handed endoscope-guided surgery, an assistant would most often need to hold a sucker in the meatus. Either inefficient suctioning of the smoke or there is an increased risk of the suction device accidentally advancing into the stapes [15]. The single-handed LASER-suction system with suction was first described in 2006 [21] and was developed to avoid such a scenario. It is similar to the concept of suction diathermy, where one device contains both diathermy and suction functions. Yet, the device was very bulky that cannot be fit into the ear canal. This time, we can build this simple device ourselves instead of using a prefabricated production from the manufacturers. It is a device made from readily available materials and can be easily constructed even by inexperienced hands. Considering the short time required to train and build the device, there is no doubt that it can be easily out into practice.

Description of Technique

The innovative Single-Handed LASER-suction-Y connecting (LASY) System. To build the instrument for the single-handed LASY system, only simple instruments that are commonly seen in an operating theatre were needed. That include a plastic or Silicon suction catheter, an 18-gauge (for 300mm LASER fiber) or 16-gauge (for 400mm LASER fiber) intravenous (IV) cannula, a disposable Zoellner suction tube, a fine tip of 18-gauge and a LASER device with LASER fiber (the TruBlue LASER system is used here for demonstration).

The intravenous (IV) cannula (here we use the 18-gauge for demonstration) is inserted into the plastic suction tube towards the end attaching to the Zoellner suction tube and withdraw the introducer.

 Leaving the plastic cannula inside the suction tube (Figure 1).

Figure 1:The intravenous (IV) cannula (here we use the 18-gauge for demonstration) is inserted into the plastic suction tube towards the end attaching to the Zoellner suction tube, and withdraw the introducer. Leaving the plastic cannula inside the suction tube.

The LASER fiber (here we use 300nm LASER fiber for demonstration purposes) is inserted into the lumen of the suction tube via the IV cannula. Continue to advance the fiber, until approximately 20 cm of the fiber emerges from the funnel port (Figure 2).

Figure 2: The LASER fiber (here we use 300nm LASER fiber for demonstration purposes) is inserted into the lumen of the suction tube via the IV cannula. Continue to advance the fiber, until approximately 20 cm of the fiber emerges from the funnel port.

Gradually insert the disposable Zoellner suction tube, thread the fiber and then the fine tip of 18-gauge along the LASER fiber like a guide wire and connect it to the funnel connector. Adjust the length of the exposed laser fiber to about 3 mm from the fine tip to facilitate suctioning of blood and fluid (Figures 3,4) showed the intraoperative view when applying this LASY system.

Figure 3: Gradually insert the disposable Zoellner suction tube, thread the fiber and then the fine tip of 18-gauge along the LASER fiber like a guide wire and connect it to the funnel connector. Adjust the length of the exposed laser fiber to about 3 mm from the fine tip to facilitate suctioning of blood and fluid.

Figure 4: Intraoperative view of using the LASER-suction system.

Methods

In this a multicentered prospective study in 4 different university-affiliated tertiary hospitals in Hong Kong, including Prince of Wales Hospital, Alice Ho Miu Ling Nathersole Hospital, Tseung Kwan O Hospital and United Christian Hospital. From April 2023 to October 2023, doctors and nurses from the operating room were recruited for the study. The first author demonstrated the assembly techniques to the staff. They were given questionnaires to complete, in which they were asked to state their professional experience of between 1 and more than 10 years. They were either assembling the device for the first time or only had some experience of assembling instruments. The entire process was staggered over time and the level of difficulty of assembly was rated on a scale of very easy, easy, moderately difficult, difficult and very difficult.

Results

43 healthcare professionals, including 34 nurses and 9 doctors, were included in the study. 12 (27.9%) of them who have less than 5 years of experience, 15 (34.9%) have 5-10 years of experience and 16 (37.2%) had more than 10 years of experience (Table 1).

Table 1. Characteristics of the Health Professionals

The mean time to set up this device for the first time was only 109.9 seconds (less then 2 minutes) and the time to set-up dropped significantly with experience (Table 2).  

Table 2: Mean time used to assemble the single-handed LASER-suction system

The results show a steep learning curve for setting up the device (Figure 5)

Figure 5: The mean time to set up the device decreases significantly with experience

As the mean time for the 3rd time assembling the device dropped to 60.7 seconds (1 minute). From the 3rd time onward, the curve begins to plateau and kept the average time to finish setting up at around 1 minute. 35 (81%) of the participants considered it easy or very easy, the remaining 8 (19%) considered it moderately difficult and none of them think it was difficult or very difficult (Figure 6).