The otolaryngologist will find in this article a direct and frank discussion and useful advice for how to get started performing solely endoscopic ear surgery for abnormalities of the middle ear. The author provides discussion and photos based on his experience with this procedure. Presented herein are selection of the endoscope, how to approach the first fully endoscopic procedure, patient selection, preoperative planning, setting up the operating room, pitfalls typically encountered, and how to gain skills to perform this procedure successfully.
Key points
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Endoscopic ear surgery allows a minimally invasive approach to the middle ear.
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The technique has a different learning curve than traditional techniques; training is useful to allow more consistent progress when getting started.
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It can be useful to collaborate with other, more experienced surgeons who are more familiar with endoscopic ear surgery.
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A high-resolution computed tomography scan is useful before any middle ear procedure whereby the endoscopic approach is to be used.
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It is vital to discuss whether more invasive surgery may need to be undertaken should the endoscopic approach not be successful at the first instance.
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Undertaking endoscopic ear surgery through a narrow external auditory meatus can be challenging, but there are several techniques that will help considerably and allow for the wide view of the endoscope to be used to maximum advantage.
Instrumentation and equipment
Overview
Undertaking endoscopic ear surgery uses techniques similar to those of standard microscopic ear surgery, but does so through a very different approach to the middle ear and to abnormalities therein. The instruments required are similar to those used in standard ear surgery with the exception that certain dissectors and a forceps need to be adapted so as to take advantage of the endoscope’s ability to “see round corners.” The most basic instrument sets will be sufficient to undertake simple cholesteatoma and tympanoplasty surgery, but as the surgeon becomes more confident and experienced in the technique of endoscopic ear surgery, so will the requirement for more advanced tools increase.
Despite the fact that the instruments used during endoscopic middle ear surgery are very similar to those for standard ear surgery, the way in which they are used differs considerably. Because the entrance to the ear canal is not constrained by a speculum, the surgeon is allowed a far wider angle of approach when using instruments in the more inaccessible areas of the middle ear such as the hypotympanum or retrotympanum.
Perhaps the most major departure in technique is the one-handed nature of endoscopic ear surgery. The endoscope is held in the nondominant hand while the opposite hand undertakes the majority of the surgery. Although this seems somewhat difficult and perhaps strange at first, on analysis, the function of the nondominant hand during traditional surgery is usually to maintain suction and remove blood from the operative field while the dominant hand still undertakes the majority of the delicate surgery. Given that an endoscopic approach is considerably less traumatic than a standard approach to the middle ear, there is usually far less bleeding, so the need for suction is reduced considerably.
Choice of Endoscope
Endoscopes come in a wide array of lengths, diameters, and angles of view. Each has its own advantages and disadvantages, but the general rule is that the larger the diameter of the endoscope, the better the field of view and the better is the illumination delivered by the light bundles carried alongside the lens. As a result, a longer, wider endoscope is the preferred instrument for work in the middle ear. Most middle ear endoscopic surgeons will undertake the majority of their surgeries using a 14- to 18-cm, 3-mm diameter 0° Hopkins rod and scope (the same endoscope used for sinus surgery). In fact, it is unusual to need to change to a larger angle to achieve a good view of all of the middle ear. Sometimes, particularly in the sinus tympani, it may be necessary to change to a 30° endoscope or, even more rarely, a 45° endoscope, but this is unusual given the very wide field of view available using low-angle endoscopes. The length is important as well, given that additional endoscopes used to augment the microscopic approach to the middle ear are normally very short. An important advantage of using a longer endoscope is that the surgeon’s two hands will be at different distances from the ear canal, and thus are less likely to interfere with one another during surgery ( Fig. 1 ).
Although a high-quality Hopkins rod is paramount, it is also vital to ensure that the digital camera attached to the endoscope is also of very high specifications. One of the most important considerations is that the camera needs to be a 3CCD (triple charge-coupled device) camera rather than a single-chip camera. The reason for this is that single-chip cameras are prone to “red-out” when they are used in a very small area that contains areas of bleeding. Even though there is not much bleeding during endoscopic ear surgery, the field tends to get reddened; this causes complete saturation of the camera and the entire field takes on an orange hue, which makes the identification of anatomic structures very difficult. Undertaking surgery with a single-chip camera is not advisable, particularly for a beginner.
Collaboration
With the technique of endoscopic ear surgery expanding rapidly across the world of otology, it can be useful to collaborate with other, more experienced surgeons who are more familiar with this type of surgery. Although most experienced otologic surgeons will require no formal training to begin endoscopic ear surgery, attending a course on the technique can be of considerable value. Most courses are based around cadaveric dissection of fresh-frozen or partially preserved cadavers; unrestricted dissection of cadaveric specimens allows surgeons to experiment with the endoscope and gain the skills required to gain maximum benefit from the extended view that comes with an endoscopic view.
Although getting started right away with simpler cases is perfectly reasonable, making a clinical visit to a surgeon who is already using the technique extensively can steepen the learning curve for endoscopic ear surgery. Many small technical tips can be of considerable value when undertaking endoscopic ear surgery, and these “pearls” are best learned at the elbow of an experienced surgeon who has garnered these skills over a career focused on this technique.
Instrumentation and equipment
Overview
Undertaking endoscopic ear surgery uses techniques similar to those of standard microscopic ear surgery, but does so through a very different approach to the middle ear and to abnormalities therein. The instruments required are similar to those used in standard ear surgery with the exception that certain dissectors and a forceps need to be adapted so as to take advantage of the endoscope’s ability to “see round corners.” The most basic instrument sets will be sufficient to undertake simple cholesteatoma and tympanoplasty surgery, but as the surgeon becomes more confident and experienced in the technique of endoscopic ear surgery, so will the requirement for more advanced tools increase.
Despite the fact that the instruments used during endoscopic middle ear surgery are very similar to those for standard ear surgery, the way in which they are used differs considerably. Because the entrance to the ear canal is not constrained by a speculum, the surgeon is allowed a far wider angle of approach when using instruments in the more inaccessible areas of the middle ear such as the hypotympanum or retrotympanum.
Perhaps the most major departure in technique is the one-handed nature of endoscopic ear surgery. The endoscope is held in the nondominant hand while the opposite hand undertakes the majority of the surgery. Although this seems somewhat difficult and perhaps strange at first, on analysis, the function of the nondominant hand during traditional surgery is usually to maintain suction and remove blood from the operative field while the dominant hand still undertakes the majority of the delicate surgery. Given that an endoscopic approach is considerably less traumatic than a standard approach to the middle ear, there is usually far less bleeding, so the need for suction is reduced considerably.
Choice of Endoscope
Endoscopes come in a wide array of lengths, diameters, and angles of view. Each has its own advantages and disadvantages, but the general rule is that the larger the diameter of the endoscope, the better the field of view and the better is the illumination delivered by the light bundles carried alongside the lens. As a result, a longer, wider endoscope is the preferred instrument for work in the middle ear. Most middle ear endoscopic surgeons will undertake the majority of their surgeries using a 14- to 18-cm, 3-mm diameter 0° Hopkins rod and scope (the same endoscope used for sinus surgery). In fact, it is unusual to need to change to a larger angle to achieve a good view of all of the middle ear. Sometimes, particularly in the sinus tympani, it may be necessary to change to a 30° endoscope or, even more rarely, a 45° endoscope, but this is unusual given the very wide field of view available using low-angle endoscopes. The length is important as well, given that additional endoscopes used to augment the microscopic approach to the middle ear are normally very short. An important advantage of using a longer endoscope is that the surgeon’s two hands will be at different distances from the ear canal, and thus are less likely to interfere with one another during surgery ( Fig. 1 ).
