Comparing the Clinical Orientation Benefits of Endoscopic demonstration on the Nose, Paranasal Sinuses, and Skull Base Versus Cadaveric Dissection for First-Year Medical Undergraduates

Abstract

The study aims to evaluate the advantages of using endoscopic demonstrations to teach nose, paranasal sinuses, and skull base anatomy compared to traditional cadaveric demonstrations. Traditional dissection methods do not provide an accurate representation of in vivo visualization of these anatomical areas. The goal is to align the teaching approach with the perspective students will have during clinical practice for better clinical orientation. In this study, 100 first-year medical students were split into two groups: Group A and Group B, each with 50 students. Group A received teaching through endoscopic demonstrations, while Group B had cadaveric demonstrations, both focused on nose, paranasal sinuses, and skull base anatomy. To assess comprehension and clinical orientation, both groups completed a questionnaire with clinically relevant questions, and their responses were collected and compared for analysis. Students who received endoscopic training showed better accuracy in addressing clinical queries than those only exposed to cadaveric dissection. Many participants favored incorporating endoscopic instruction, either as a replacement or addition to traditional cadaveric dissection, for the studied topics. The endoscopically trained group performed better in understanding anatomical landmarks, mentally reconstructing 3D images, and conceptualizing surgical approaches for the targeted anatomical areas. Incorporating endoscopic training for the nasal cavity, paranasal sinuses and skull base into the undergraduate medical curriculum would substantially augment students’ clinical understanding and provide a more profound grasp of the dynamic anatomy in these areas.

Introduction

Dissection has long been recognized as a powerful tool for teaching medical professionals about the internal structures of the human body. While it provides a valuable orientation to various anatomical features, it comes at the cost of significant tissue damage. Traditional dissection practices mainly focus on demonstrating normal anatomy, neglecting the utilization of dissection techniques for understanding surgical approaches. Certain anatomical areas, such as the Nasal cavity, Paranasal sinuses, and structures around the Skull base, present challenges for effective demonstration using traditional dissection methods. Despite extensive dissection and sectioning in cadavers, interpreting three-dimensional images of these structures remains difficult. An alternative approach using endoscopic visualization in cadavers has shown promise in demonstrating and comprehending the normal anatomy in this region [1, 2].

The endoscopic approach holds great potential for teaching undergraduates prior to embarking on dissection, enabling them to gain a better understanding of normal anatomy [3]. Additionally, it can aid practicing surgeons in refining their surgical skills and mastering surgical techniques [4]. By comparing gross and endoscopic anatomy through dissection steps, surgeons can develop an in-depth knowledge and understanding of anatomical landmarks. Therefore, a combined approach of endoscopic and cadaveric dissection will create a three-dimensional mental image, enhancing the comprehension of the anatomy in this area and providing invaluable assistance in managing complex surgical situations [5].

In order to perform endoscopic surgeries of the Nose and Paranasal sinuses, a profound understanding of the anatomical structures around the base of the skull is crucial. This training necessitates developing a strong sense of orientation and correlating anatomical and endoscopic views of the structures. Numerous endoscopic surgeries and training programs are conducted in various institutes to train postgraduates, residents, and consultant surgeons. These workshops typically employ cadavers to familiarize surgeons with the topography of structures as visualized endoscopically. The endoscopic endonasal approach is commonly employed to demonstrate and practice surgical skills in and around the cranial cavity, including the nasal cavity, paranasal sinuses, orbit, and venous sinuses of the cranial cavity, structures around the basi-occiput, and vascular structures at the base of the skull [6–10]. Existing literature predominantly focuses on honing the surgical skills of surgeons and postgraduates, offering limited guidance for orienting undergraduates in developing these skills during their initial years of anatomy coursework. Incorporating endoscopic demonstrations of anatomical structures before dissection would provide undergraduates with an additional advantage in comprehending anatomy and later applying it clinically during surgical postings, thereby refining their surgical skills [11].

The primary objective of this study was to evaluate the supplementary advantages that students acquire through an endoscopic approach in comprehending the anatomy of the Nasal cavity, Paranasal sinuses, and anterior skull base. Furthermore, the study aimed to assess the clinical familiarity gained by students with respect to these areas through the use of endoscopy.

Methodology

This study was aimed to orient first-year MBBS students of [XXXX] to the endoscopic visualization of concealed structures around the nasal cavity and skull base that are not visible during routine dissection. These areas were routinely taught to the students by various sagittal, parasagittal and coronal sections of head and neck. The study was designed to provide endoscopic teaching of these areas before regular dissection. A total of 15 h of teaching was provided, divided into five lectures of three hours each. The batch of 100 students was divided into two groups: Group-A and Group-B, each consisting of 50 students. The group assignment were randomized by calling out numbers 1 and 2 alternately. All students calling out number 1 were placed in Group-A, while those calling out number 2 were assigned to Group-B. Group-A received additional exposure to the endoscopic approach for the mentioned areas before cadaveric dissection, while Group-B had exposure through routine cadaveric dissection only. A pre-questionnaire and a post-questionnaire were given to Group A and Group B before the start and at the end of each topic, to assess any benefits gained from the endoscopic approach. The questionnaires were customized according to the anatomical structure taught or shown in the lecture. Apart from the general questions some clinical questions were also asked in post-questionnaire with every topic to evaluate their understanding by two different methods. Pre questionnaire were given to Group-A and Group-B containing five questions each, before they were exposed to endoscopy (Pro forma 1A) (Fig. 1) or cadaveric (Pro forma 2A) (Fig. 1) dissection respectively. Pre questionnaire contained questions regarding their exposure to prior cadaveric or endoscopic methods of concerned areas, their level of understanding about the way of teaching of the areas under study, surgical approach to these areas and their prior thoughts in preference to any of the two methods of teaching. Responses from them were collected in Google forms. After the endoscopic exposure of each topic the post questionnaire containing ten questions was shared with Group-A (Pro forma 1B) (Fig. 1) through Google forms and the responses were collected and the data was compiled. Further after the cadaveric dissection of the respective topics the post questionnaire was shared through Google forms with Group-B (Pro forma 2B) (Fig. 1), the responses were collected and the data was compiled. Data compiled from Group-A and Group-B was compared to see for the beneficial effect of one method of teaching over another. After the cadaveric dissection exposure of whole batch the post questionnaire was again shared with Group-A (Pro forma 1C) (Fig. 1). This response recorded from Group-A was after the endoscopic exposure and cadaveric dissection.

Fig. 1.

Pre and post questionnaires for endoscopic and cadaveric teaching

The post exposure questionnaire contained questions regarding the briefing about the method of exposure and the concerned areas that students are going to be taught, their understanding of basic steps their orientation regarding identification of anatomical landmarks. Students were also accessed on Likert’s scale in terms of their level satisfaction for identifying anatomical landmarks, their ability to mentally reconstruct spatial orientation and their insight about how to surgically approach the concerned areas. Three clinical oriented questions were also asked to both Group-A and Group-B separately to assess any benefit of clinical knowledge attainted of any Group over the other. Lastly a question was asked whether to replace the teaching of the concerned areas with some other or additional method. This data was also compiled to see for any beneficial effects of the combined approach in teaching these areas.

The study was aimed to orient the students regarding the following areas:

Endonasal endoscopic approach to Nasal cavity, to Paranasal sinuses (Maxillary, Ethmoid, Frontal, and Sphenoidal), to Anterior Skull base, to Orbit and Optic nerve and to Lacrimal Sac. Before the routine dissection of the relevant parts, the anatomy of the structures were demonstrated endoscopically to the Group-A as visualized during surgical procedures.

The instruments required for the demonstrations included Endoscopic camera system, Rigid nasal endoscopes (4 mm 0, 30 and 70 degree), Halogen Light source, Laptop, Suction machine, Hand instruments for endoscopic sinus surgeries.

The inclusion criteria to be a participant in the study was that the students must be enrolled in the first-year MBBS course and the students should not have prior exposure to endoscopic teaching. Students who were unwilling to attend and participate in the course were excluded.

Observation

After comparing the Pre questionnaire of cadaveric and endoscopic exposure it was observed that none of the students have any exposure of endoscope prior to this project and only 2% of students were exposed to cadavers before but not the areas under study. Approximately 90% of the population in both Group A and Group B were unaware of the fact that the areas under study are seen in live patients through endoscope and during cadaveric study, by showing various sections of head. Approximately three quarter of the population in Group A believed that the endoscopic visualization will improve their understanding of relevant clinical approach. One fourth of the students in Group B believed that endoscopic teaching of the concerned areas should replace the cadaveric teaching. The percentage of students believing the same was less (approximately one fifth) in Group A students.

On comparing the Question 4 of pro forma 1A with Questions 7, 8 and 9 of Pro forma 1B of Endoscopic exposure it was observed that there was remarkable improvement in the Group A regarding the clinical orientation of the concerned areas. The students who have been exposed to the endoscopic orientation were able to answer the clinical questions more correctly than the students exposed to only cadaveric dissection. In about one third population, the students who gave the correct answers were actually more than the number who initially believed that endoscopic visualization will improve their relevant clinical approach in pre questionnaire (Question 4 of Pro forma 1A). On comparing the Question 5 of Pro forma 1A with Questions 10 of Pro forma 1B of Endoscopic exposure it was observed that significant number of students believed that the endoscopic teaching of the areas under study should actually replace the cadaveric dissection (Table 1).

Table 1.

Association between clinical orientation of the participants before and after cadaveric and endoscopic exposure

Category	Sub category	Cadaveric		p Value	Endoscopic		p Value
		PRE	POST		PRE	POST
Anterior skull base	Q7	74.5	19.4	< 0.001	74.2	52.2	0.018
	Q8		51.6	0.034		91.3	0.024
	Q9		38.7	0.0013		34.8	< 0.001
Lacrimal	Q7		16.7	< 0.001		86.7	0.082
	Q8		16.7	< 0.001		38.3	0.0001
	Q9		50.0	0.025		50.0	0.006
Nasal	Q7		40.0	0.009		78.7	0.557
	Q8		30.0	0.0001		75.4	0.878
	Q9		33.3	0.0003		86.9	0.076
Orbit	Q7		25.0	< 0.001		64.7	0.273
	Q8		40.0	0.0009		39.2	0.0002
	Q9		40.0	0.0009		64.7	0.273
Paranasal	Q7		46.7	0.012		26.3	< 0.001
	Q8		26.7	0.0001		63.2	0.195
	Q9		13.3	< 0.001		49.1	0.005
Anterior skull base	Q10	25.5	80.6	< 0.001	19.4	87.0	< 0.001
Lacrimal			83.3	< 0.001		85.0	< 0.001
Nasal			90.0	< 0.001		88.5	< 0.001
Orbit			87.5	< 0.001		82.4	< 0.001
Paranasal			83.3	< 0.001		84.2	< 0.001

Significant p values are highlighed in bold

On comparing the Question 4 of Pro forma 2A with Questions 7, 8 and 9 of Pro forma 2B of Cadaveric exposure it was observed that clinical orientation was not good for the areas under study. The percentage of students who gave the correct answers to clinically oriented questions was much less in Group B compared to Group A. In whole of the Group B population, the students who gave the correct answers were much less than the number who initially believed that cadaveric exposure will improve their relevant clinical approach in pre questionnaire (Question 4 of Pro forma 2A). On comparing the Question 5 of Pro forma 2A with Question 10 of Pro forma 2B of Cadaveric exposure it was observed that significant number of students believed that and additional or alternative means to orient the areas under study is needed apart from cadaveric dissection (Table 2).

Table 2.

Comparison of clinical orientation of participants after cadaveric and endoscopic exposure

Category	Sub category	POST		p Value
		Cadaveric	Endoscopic
Anterior skull base	Q7	19.4	52.2	0.0040
	Q8	51.6	91.3	0.0001
	Q9	38.7	34.8	0.7270
Lacrimal	Q7	16.7	86.7	< 0.001
	Q8	16.7	38.3	0.0369
	Q9	50.0	50.0	1.000
Nasal	Q7	56.7	78.7	0.0289
	Q8	30.0	75.4	< 0.001
	Q9	33.3	86.9	< 0.001
Orbit	Q7	25.0	64.7	0.0001
	Q8	40.0	39.2	0.9380
	Q9	40.0	64.7	0.0190
Paranasal	Q7	46.7	26.3	0.0550
	Q8	26.7	63.2	0.0012
	Q9	13.3	49.1	0.0010
Anterior skull base	Q10	80.6	87.0	0.4480
Lacrimal		83.3	85.0	0.8340
Nasal		90.0	88.5	0.8300
Orbit		87.5	82.4	0.5328
Paranasal		83.3	84.2	0.9130

Significant p values are highlighed in bold

On comparing the Questions 4, 5 and 6 of Pro forma 1B and 2B in Post questionnaires of Cadaveric and Endoscopic exposure it was observed that the difference in Group A and Group B were statistically not significant in most of the answers. The results were comparatively better in the endoscopically exposed group regarding the student’s ability to understand the anatomical landmarks, to mentally reconstruct three dimensional image and how to surgical approach the concerned area under study (Table 3).

Table 3.

Comparison of anatomical spatial and surgical orientation and between cadaveric and endoscopic exposure

Category		Q4					Q5					Q6
		Cadaveric		Endoscopic		p Value	Cadaveric		Endoscopic		p Value	Cadaveric		Endoscopic		p Value
		FREQ	%	FREQ	%		FREQ	%	FREQ	%		FREQ	%	FREQ	%
Anterior skull base	0.00	0	0.0	0	0.0	0.906	0	0.0	0	0.0	0.402	0	0.0		0.0	0.219
	1.00	0	0.0	0	0.0		8	10.3	2	4.3		8	10.3	3	6.5
	2.00	48	61.5	27	58.7		1	1.3	2	4.3		2	2.6	0	0.0
	3.00	14	17.9	8	17.4		52	66.7	29	63.0		51	65.4	26	56.5
	4.00	16	20.5	11	23.9		17	21.8	13	28.3		17	21.8	17	37.0
Lecrimal	0.00	2	2.4	0	0.0	0.782	3	3.6	0	0.0	0.590	2	2.4	1	1.7	0.018
	1.00	3	3.6	2	3.3		13	15.5	7	11.7		16	19.0	2	3.3
	2.00	50	59.5	35	58.3		2	2.4	2	3.3		2	2.4	0	0.0
	3.00	18	21.4	13	21.7		50	59.5	39	65.0		51	60.7	39	65.0
	4.00	11	13.1	10	16.7		16	19.0	12	20.0		13	15.5	18	30.0
Nasal	0.00	2	2.5	0	0.0	0.009	1	1.3	0	0.0	0.147	1	1.3	0	0.0	< 0.001
	1.00	0	0.0	2	3.3		8	10.0	3	4.9		12	15.0	1	1.6
	2.00	50	62.5	35	57.4		2	2.5	2	3.3		2	2.5	0	0.0
	3.00	16	20.0	4	6.6		52	65.0	32	52.5		53	66.3	27	44.3
	4.00	12	15.0	20	32.8		17	21.3	24	39.3		12	15.0	33	54.1
Orbit	0.00	1	1.1	1	2.0	0.333	0	0.0	0	0.0	0.264	0	0.0	0	0.0	0.145
	1.00	59	63.4	29	56.9		15	16.1	3	5.9		14	15.1	2	3.9
	2.00	20	21.5	8	15.7		6	6.5	2	3.9		1	1.1	0	0.0
	3.00	13	14.0	13	25.5		54	58.1	36	70.6		56	60.2	32	62.7
	4.00	0	0.0	0	0.0		18	19.4	10	19.6		22	23.7	17	33.3
Paranasal	0.00	2	2.5	0	0.0	0.525	1	1.3	0	0.0	0.635	2	2.5	0	0.0	0.027
	1.00	1	1.3	0	0.0		10	12.5	4	7.0		13	16.3	3	5.3
	2.00	49	61.3	35	61.4		2	2.5	3	5.3		1	1.3	1	1.8
	3.00	14	17.5	14	24.6		50	62.5	36	63.2		50	62.5	31	54.4
	4.00	14	17.5	8	14.0		17	21.3	14	24.6		14	17.5	22	38.6

Significant p values are highlighed in bold

In this study, we did not include a comparison between the combined Pro forma 1C approach and each of the individual exposure methods due to concerns about managing the extensive amount of data. However, the combined exposure approach led to notable enhancements in spatial orientation, surgical approach, and clinical comprehension of the relevant anatomy. It was clearly demonstrated to be superior to any singular approach for educational purposes.

Discussion

Obscured anatomy of the nasal cavity, paranasal sinuses, anterior skull base and the neighboring important structures make it really difficult to teach these areas by cadaveric dissection. Orienting the students with various section of head and radiological images help understand normal anatomy to some extent but even then they are not familiar to surgical approach to these areas. Present study was planned to teach the students in a way they will be seeing these areas later in the patients. Now a days almost all surgeries performed on nasal cavity, paranasal sinuses, and anterior skull base are done by endonasal endoscope. An effort was made to teach the first year MBBS Students with endonasal endoscope the normal anatomy and important surgical landmarks. The evolution of teaching and learning approaches, transformative shifts in healthcare delivery, and the swift advancement of technology have posed challenges to the conventional methods of developing clinical skills. Consequently, this has given rise to the establishment of clinical skills laboratories to adapt and enhance medical education for medical students [12]. Allowing undergraduate students to actively engage in learning adds value by enhancing image orientation and interpretation, and the clinical experience further fuels enthusiasm during the session [13] With advancing technology and new concepts of teaching being introduced it has now become an need of the hour to implement the newer techniques and deliver the knowledge to medical students in a more clinical oriented manner. The best way to learn is by having regular teaching sessions throughout the education period, where we can practice and be hands-on during the sessions [14]. In order to enhance academic success, optimize the effective management of learner time, maximize future surgical competencies, and improve the retention of anatomical knowledge, we believe it is essential to integrate new teaching practices into the educational framework. The utilization of a model employing diverse learning techniques in anatomy education has consistently been praised by fellow anatomists, particularly for guiding medical students in a clinical context [15]. Students exposed to clinical anatomy showed notably superior performance in the final examinations compared to those who were not which emphasis on clinical anatomy education and integrate it seamlessly into the gross anatomy curriculum [16]. Up to this point, diverse approaches have been employed in the teaching of Anatomy. These encompass didactic lectures, prosection or dissection, diagrams and body paintings, as well as paper, plastic, and resin models. Additionally, methods such as plastinated specimens, 3D printing, radiology, and virtual simulation have been utilized [17, 18]. Though the proper clinical orientation is efficiently demonstrated by the Ultrasound teaching and radiological imaging. There have been multiple studies indicating the efficiency of these techniques in enhanced understanding of clinical anatomy [19–22].

Our study is pioneering in its approach, utilizing the endonasal endoscope for instructing on the intricacies of the nose, paranasal sinuses, and the surrounding regions of the skull base. The endonasal endoscope has been employed primarily in cadaveric contexts for aiding the instruction and skill refinement of surgeons, particularly in the fields of ENT (Ear, Nose, and Throat)—head and neck surgery and Neurosurgery. The aim of our study was to introduce undergraduate students to the spatial understanding of these concealed regions from the outset, aligning with what they would encounter in live patients, where endoscopes are routinely used for diagnostic and surgical purposes. We observed a significant enhancement in the students' clinical knowledge when exposed endoscopically to these areas before engaging in traditional dissection. While the majority of students did not advocate for a complete replacement of cadaveric teaching with endoscopic instruction for these regions, nearly all were in favor of integrating endoscopic teaching alongside cadaveric dissection to achieve a more comprehensive clinical orientation.

Conclusion

Endonasal endoscopes are a standard tool employed by both neurosurgeons and otolaryngologist head and neck surgeons for surgical procedures involving the nasal passages, paranasal sinuses, and the skull base. Additionally, neurosurgeons have increasingly adopted this approach for intracranial surgeries. Unfortunately, medical students are typically not exposed to these anatomical structures as they appear during endoscopic surgical procedures. Integrating endonasal endoscope training into the undergraduate medical curriculum would significantly enhance students' clinical comprehension and deepen their understanding of the dynamic anatomy within these regions. While it cannot replace traditional cadaveric dissection education, it can effectively serve as a complementary tool to augment clinical orientation and enrich the learning experience.

Author Contributions

ST and RDA—concept, supervision, critical review. JT—Design. MR—Writing, Literature search. AS—Literature search.

Funding

No funding was received to assist with the preparation of this manuscript.

Declarations

Conflict of interest

Authors have no financial interests that are directly or indirectly related to the work submitted for publication. The research did not involve human participants. Institutional Ethical Committee exemption review was obtained vide AIIMSRPR/IEC/2018/203.