TEMPORAL BONE ANATOMY EDUCATION AND SURGERY TRAINING

To gain surgical competency leading to appropriate surgical outcomes and improved patient safety, high-quality anatomy education and surgical training are crucial. The foundation of optimal surgical performance is an in-depth knowledge of each individual patient’s anatomy.

Traditionally in otological surgical training, cadaveric dissections have been considered as the gold-standard training method (George and De, 2010). In TB cadaveric dissection training, the bone is positioned on a fixator to simulate the real-life surgical position of the patient. Another way to simulate operating room conditions is that the surgical field is magnified with an operating microscope and the dissection is performed with a motorized high-speed drill with irrigation to locate and expose the

anatomical landmarks pivotal for successful surgery (Dedmon et al., 2017) (Figure 9). Training is supplemented with lectures, 2D image illustrations, a variety of dissection manuals and guided practice during live surgery in the operating theater under the supervision of an experienced otologic

surgeon. In addition, TB-dissection courses have been a mainstay for gaining surgical competency and anatomical knowledge. Generally, these courses combine lectures and expert guided hands-on cadaveric dissection training in focused training, spanning several full days.

Figure 9. Wet lab and temporal bone dissection training. (Published with courtesy of Microsurgery Center of Eastern Finland, Kuopio University Hospital)

2.3.1Challenges of traditional training

In recent decades, due to the increased demands on productivity, the hours available for experienced otologic surgeons to participate in training residents and novice otologic surgeons have become severely reduced as these individuals themselves have to spend most of their time in the clinic (Ghosh, 2017; Reznick and MacRae, 2006). Additionally, the opportunities for cadaveric dissections have significantly decreased due to the limited access to TBs, facilities, and training resources (Frithioff et al., 2018a; Mills and Lee, 2003).

If the surgeon is to obtain a profound mental concept of the anatomy of the TB and valid preoperative planning skills, he/she needs to extract the information from 2D images and illustrations describing the anatomy of the TB and combine it with the acquired pre-existing knowledge of the 3D

conducted an extensive amount of repetitive surgical rehearsals and also have experience in preoperative planning, radiological image viewing, and live surgery (Ericsson, 2004; Halm et al., 2002). Thus, it has been reported that both residents and novice otologic surgeons in the early stages of their career often struggle with gaining an in-depth understanding of 3D anatomy from 2D images (e.g., cross-sections of CT) and illustrations (e.g., dissection manuals) (Bergman et al., 2011; Gnanasegaram et al., 2020;

Nicholson et al., 2006; Triepels et al., 2020). Hence, complementary, and new effective training and educational methods are needed.

2.3.2Assessment of surgical performance and training

A realistic assessment of effective learning methods, surgical skills and performance has become more and more essential in modern medicine.

Nonetheless, the lack of objective standardized and validated evaluation methods and assesment tools poses a challenge i.e. how to measure a trainee’s competence and whether some new method would be able to improve his/her performance. There are few tools available with which to conduct an evidence-based and validated assessment, however a growing number of investigators have started to address this issue in recent years.

In otology, several performance assessment tools especially aimed at mastoidectomy have been introduced (Sethia et al., 2017). The objective structured assessment of technical skill (OSATS) developed by Martin et al.

is a performance-based assessment of technical skills and has been validated in other surgical fields (Martin et al., 1997). Since then, different modifications of OSATS to evaluate mastoidectomy performance in the laboratory and in operating room capable of validly assessing both

performance have been introduced (Francis et al., 2010; Laeeq et al., 2009).

The Welling scale is another scale used in the performance assessment of mastoidectomy in cadaveric and simulation training; this was first

introduced by Butler and Wiet (Butler and Wiet, 2007), and it has

subsequently been modified. The Welling scale has been used in multiple studies, which have demonstrated its validity (Andersen et al., 2015, 2016;

Wijewickrema et al., 2015; Yi C. Zhao et al., 2011). However, the scale has

been criticized, since it does not include some crucial surgical landmarks (e.g., antrum, facial recess) and does not assess the entire surgical process (Sethia et al., 2017).

While OSATS and the Welling scale and their modifications are

considered as the current leaders in the field, they are still claimed to need refinement and in overall large multicenter studies are still needed in order to increase the validity and feasibility of different scales prior to their universal acceptance (Sethia et al., 2017).

In recent years, surgical simulation training has introduced the

possibility for repeated and distributed training with immediate feedback or guidance and summative score at the final stage of the procedure.

Objective automated assessment tools for mastoidectomy have been under vigorous development in various VR simulator platforms (Al- Shahrestani et al., 2019), as it has been claimed that they could lead to significant time and resource savings in comparison to the traditional, and often subjective, assessment of surgical competence. However, there is no general consensus for their general acceptance; at present, there is

insufficient evidence of their validity and reliability and therefore further studies are necessary (Al-Shahrestani et al., 2019; Andersen et al., 2019).