Integrating a Cadaver Review Session into the Existing Regional Anesthesia Training for Anesthesiology Residents: An Initial Experience

Abstract

The Department of Anesthesiology’s Acute Pain Service (APS) places ultrasound-guided peripheral nerve blocks (PNBs) to manage acute peri-operative pain. PNB success is dependent on detailed anatomical knowledge which residents may not have formally reviewed since medical school. This study describes the integration of a cadaver review session (CRS) that reintroduces PNB-related anatomy into the existing APS rotation. During each CRS, an anatomist reviewed the major nerve and surrounding structures, while an APS attending integrated the anatomy with PNB techniques. During the pilot, 1st- and 3rd-year clinical anesthesia (CA) residents (9 CA1s, 7 CA3s) completed pre- and post-session surveys and rated the CRS’s perceived value and impact on self-confidence with anatomical knowledge. Following the pilot, an additional 17 CA1s and 9 CA3s participated in the CRS and completed post-session surveys. Descriptive statistics were used to summarize responses and unpaired t tests were used to compare pre- and post-session responses and responses between cohorts. All participants were overwhelmingly positive about the CRS and its value to the APS rotation, with 98% agreeing they recommend the CRS and found it accessible. Residents believed participation would improve board exam (average = 4.83 ± 0.66) and clinical performance (average = 4.86 ± 0.65), and self-reported increases in confidence with anatomical knowledge. Residents in the pilot group reported significantly greater confidence (p < 0.01) in their perceived anatomical knowledge after the CRS. The CRS positively impacted resident confidence in their anatomical knowledge and perceived ability to identify anatomical structures. Residents reported the CRS was a highly valued addition to regional anesthesia training.

Background

Our anesthesiology Acute Pain Service (APS) assists in the management of peri-operative pain using multiple modalities, including regional anesthesia techniques such as peripheral nerve blocks (PNBs). In the past, PNBs were primarily performed using landmark-based techniques and nerve stimulation, but with the greater availability of ultrasound imaging, ultrasound-guided PNBs have become increasingly popular [1]. Ultrasound guidance allows for real-time visualization of nerves and associated structures, needle placement, and the spread of local anesthetic around desired structures resulting in improved success by novice providers, shorter times for block placement, fewer needle passes, less local anesthetic volume used, fewer complications, and improved effectiveness [1–4]. Post-operatively, patients report greater satisfaction due to improved pain control, reduced nausea and vomiting, shorter hospital stays, and a quicker return to daily activities [1, 5]. From the hospital’s perspective, PNBs help to reduce some of the costs of patient care and help reduce the risk of opioid dependency and abuse [5, 6].

However, even with ultrasound guidance, PNBs are not risk-free. All PNB placements include the rare risk of local anesthetic systemic toxicity and injury to associated vascular and nervous structures [5]. Although many of these complications can be minimized through ultrasound, the incidence of errors and the associated morbidity is of great concern. In the 2007 Joint Commission Wrong-Site Surgery Summit, the anesthesiology specialty was reported to have experienced a significant increase in errors, primarily from PNBs [7]. Between 1995 and 2005, PNBs comprised 2% of all anesthesiology-related errors, but spiked to 16% by 2006 and then to 20% by 2007 [7, 8]. In some subspecialties, such as non-spinal orthopedic surgeries, regional anesthesia is still involved in 26% of error claims [9]. Even with the increased usage of ultrasound for PNB guidance, the incidence of injury has remained fairly stable [10, 11].

The anesthesiology residency curriculum outlined by the Accreditation Council for Graduate Medical Education requires a 1-month-long regional anesthesia rotation [12]. During this rotation, residents learn and perform a minimum number of neuraxial, truncal, plexus, and peripheral nerve blocks but there is no specification as to where or how those blocks should be placed. With an increase in the number of blocks in regional anesthesia and pain medicine (RAPM) literature, and no increase in training time, it follows that experience across the RAPM spectrum is probably diluted. Blocks may be placed successfully without a solid understanding of associated anatomy, which can lead to problems when placing blocks in patients with variant anatomy [13, 14].

We proposed that review activities, such as a cadaver review session (CRS), integrated into the existing residency curriculum, would complement anesthesiology residency training and provide residents with the gross anatomy knowledge and context necessary to perform PNBs with fewer complications. For this project, our purpose was to develop, pilot, and evaluate the perceived benefits of a regularly occurring CRS incorporated into an existing RAPM training program.

Materials and Methods

Development of the Cadaver Review Session for APS Residency Training

The cadaver review session (CRS) was offered on a trial basis March to August 2017, during which time anecdotal feedback was uniformly positive, and used to refine and standardize the session. For example, additional dissections were completed (e.g., posterior abdominal wall anatomy to demonstrate a quadratus lumborum block; paraspinal anatomy to demonstrate an erector spinae block) and less relevant regions was removed or deemphasized. The standardized CRS was offered monthly beginning September 2017, as part of the APS residency program curriculum.

The 2-h instructor-led CRS is held monthly in the human anatomy laboratory on the University of Colorado Anschutz Medical Campus, using a specially dissected cadaver that highlighted the major truncal, plexus, neuraxial and PNB-related nerves. Each CRS consisted of 2–4 residents from the APS, an expert anatomist, and RAPM-trained anesthesiology attending and/or fellow. During each CRS, the expert anatomist identified and reviewed the origin, function, and key relationships of PNB-related nerves in accordance with the pre-determined learning objectives (see Table 1). At the same time, the anesthesiology attending or fellow integrated the anatomy with PNB procedures and clinical cases. To promote active learning during the review session, residents were asked to identify anatomical structures directly on the cadaver, recall pertinent information when questioned, describe PNB procedures, and in turn, ask questions of the experts to deepen their understanding as a PNB practitioner. No specific advanced preparation was required, since all participants were currently engaged in the APS rotation of their anesthesiology residency program.

Table 1.

APS cadaver review session learning objectives

Learning objective
1	List the spinal segments levels that contribute to the major peripheral nerves and plexuses of the human body.
2	Describe the structure of the major peripheral nerves and plexuses of the human body.
3	Describe the landmarks and relationships associated with the major peripheral nerves and plexuses of the human body.
4	Describe the cutaneous and dermatome innervation maps of the major peripheral nerves and plexuses of the human body.
5	List the major muscles and joints supplied by the major peripheral nerves and plexuses of the human body.
6	Identify the major peripheral nerves and plexuses of the human body on a cadaver or cadaveric images.

Evaluation of the Cadaver Review Session

Exempt status for this educational study was obtained from the Colorado Institutional Review Board at the University of Colorado Anschutz Medical Campus (COMIRB Protocol #17-1427). The CRS was formally evaluated for 18 months (September 2017 to March 2019). During this time, 42 1st- and 3rd-year clinical anesthesia (CA) residents rotating on the APS (26 CA1s, 16 CA3s) participated in the CRS, and all (100%) completed the voluntary anonymous post-session online survey administered in Qualtrics©. During the initial 6-month pilot phase (September 2017–February 2018), resident participants were also invited to complete a voluntary online pre-session survey. Surveys were distributed immediately before or after each CRS session, using computers adjacent to the teaching area.

The surveys included a mixture of open, closed, multiple choice, and Likert-scaled questions to collect participant demographics (age, sex, title, and residency year) and past experiences with gross anatomy as well as evaluate participant reactions to the CRS. The Likert-scale items (5-point scale; 1 = strongly disagree, 5 = strongly agree) measured participants’ reactions in terms of the perceived value of the CRS and its impact on their confidence across seven domains of anatomical knowledge, plus perceived impact on board scores and clinical performance. Anatomical knowledge was not measured directly using the surveys.

Descriptive statistics were used to analyze survey responses, with APS residents analyzed as a pooled sample, as well as separate CA1 and CA3 cohorts. Unpaired t tests (alpha = 0.05 for statistical significance) were used to compare responses between cohorts, and between pre- and post-session responses during the pilot phase. Comparisons between cohorts (CA1 vs CA3) and samples (first 6 months vs last 12 months) were also completed using unpaired t tests, to determine equivalency of groups. All analyses were conducted using Microsoft Excel © (version 16.15, 2018).

Results

Participant Demographics

The 42 total residents surveyed in this study included 26 CA1s (Program Year 2) and 16 CA3s (Program Year 4). The resident pool was composed of 12 females and 30 males, with an average age of 31.3±6.0 years, and were on average 6.0 ±1.6 years removed from their last human gross anatomy course. All participants reported past experiences with cadaveric anatomy prior to attending the CRS.

Pre- vs Post-Session Comparison (Pilot Phase, September 2017 to February 2018)

Sixteen residents (9 CA1s, 7 CA3s) participated in the pilot phase of the CRS from September 2017 to February 2018, and all completed matched pre- and post-session surveys. Results for the pilot group are reported in Table 2 and summarized below. Prior to CRS participation, both CA1 and CA3 cohorts reported similar low to moderate self-confidence across four anatomical topics (nerve origins, cutaneous innervation, muscle innervation, key regional relationships), and in their ability to identify anatomy relevant to core PNBs on a cadaver; the cohort means were not significantly different from one another (p > 0.05). Prior to the CRS, CA3 participants reported significantly greater self-confidence than CA1s in identifying relevant anatomy on illustrations ($\overline{\mathrm{x}}$ = 3.86±0.38 vs $\overline{\mathrm{x}}$ = 2.78±1.09 respectively, p = 0.02) and on ultrasound images ($\overline{\mathrm{x}}$ = 4.14±0.69 vs $\overline{\mathrm{x}}$ = 3.22±0.97 respectively, p = 0.04). Both cohorts reported similarly high confidence that CRS participation would positively impact their board scores and clinical performance (p > 0.05). For all items on the post-session survey, no significant differences were observed between the CA1 and CA3 cohort responses (p > 0.05).

Table 2.

Pilot phase results of the cadaver review session

		Pre-survey comparison		Post-survey comparison		Pre vs post
Survey themes		CA1 (n = 9)	CA3 (n = 7)	CA1 (n = 9)	CA3 (n = 7)	Pre (n = 16)	Post (n = 16)
Impact on self-reported confidence	I felt more confident in my knowledge of ____ after the CRS.
	Nerve origins	2.78 ± 1.0 (33.3)	3.43 ± 0.79 (57.1)	4.33 ± 0.50 (100)	4.43 ± 0.53 (100)	3.06 ± 1.00 (43.8)	4.38 ± 0.50 (100)
		p = 0.19		p = 0.72		p < 0.01
	Cutaneous innervations	2.78 ± 0.97 (22.2)	3.14 ± 0.90 (42.9)	4.33 ± 0.50 (100)	4.43 ± 0.79 (85.7)	2.94 ± 0.93 (31.3)	4.38 ± 0.62 (93.8)
		p = 0.45		p = 0.79		p < 0.01
	Muscle innervations	2.67 ± 1.00 (22.2)	3.29 ± 0.95 (57.1)	4.33 ± 0.50 (100)	4.29 ± 0.49 (100)	2.94 ± 1.00 (37.5)	4.31 ± 0.48 (100)
		p = 0.23		p = 0.851		p < 0.01
	Key relationships	2.78 ± 1.20 (33.3)	3.86 ± 0.90 (85.7)	4.33 ± 0.50 (100)	4.57 ± 0.53 (100)	3.25 ± 1.18 (56.3)	4.44 ± 0.51 (100)
		p = 0.06		p = 0.38		p < 0.01
	I felt more confident identifying nerves and associated structures on ____ after the CRS.
	Illustrations	2.78 ± 1.09 (33.3)	3.86 ± 0.38 (85.7)	4.56 ± 0.53 (100)	4.57 ± 0.53 (100)	3.25 ± 1.00 (56.3)	4.56 ± 0.51 (100)
		p = 0.02		p = 0.95		p < 0.01
	Cadavers	2.67 ± 1.00 (22.2)	3.57 ± 0.79 (71.4)	4.56 ± 0.53 (100)	4.57 ± 0.53 (100)	3.06 ± 1.00 (43.8)	4.56 ± 0.51 (100)
		p = 0.06		p = 0.95		p < 0.01
	Ultrasound	3.22 ± 0.97 (44.4)	4.14 ± 0.69 (85.7)	4.56 ± 0.53 (100)	4.33 ± 0.82 (83.3)	3.63 ± 0.96 (62.5)	4.47 ± 0.64 (93.3)
		p = 0.04		p = 0.57		p < 0.01
Perceived value	The gross anatomy knowledge I learned in the CRS will help me improve performance on ____.
	Clinical duties	4.22 ± 1.30 (88.8)	4.86 ± 0.38 (100)	4.89 ± 0.33 (100)	4.86 ± 0.38 (100)	4.50 ± 1.03 (93.8)	4.88 ± 0.34 (100)
		p = 0.19		p = 0.86		p = 0.18
	Board exams	4.33 ± 1.32 (88.8)	4.86 ± 0.38 (100)	4.89 ± 0.33 (100)	4.86 ± 0.38 (100)	4.56 ± 1.03 (93.8)	4.88 ± 0.34 (100)
		p = 0.28		p = 0.86		p = 0.26
	I found the CRS accessible and easy to understand.			4.89 ± 0.33 (100)	5.00 ± 0.00 (100)
				p = 0.35
	I would recommend the CRS to other anesthesiology residents.			5.00 ± 0.00 (100)	5.00 ± 0.00 (100)

All survey items used the same 5-point Likert scale: 5 = strongly agree, 1 = strongly disagree. Percentage of residents who agreed (4) or strongly agreed (5) with the statements is reported in parentheses. Comparison of pre-session and post-session ratings were performed using the unpaired t test

Comparisons of pre- versus post-session responses demonstrate the impact of the CRS on residents’ perceptions of their self-confidence in anatomy and the value of the session (Table 2). Residents reported significantly greater confidence in their anatomical knowledge after the CRS: perceived ability to identify nerve origins ($\overline{\mathrm{x}}$_Pre = 3.06±1.00 vs $\overline{\mathrm{x}}$_Post = 4.38±0.50, p < 0.01), cutaneous innervations ($\overline{\mathrm{x}}$_Pre = 2.94±0.93 vs $\overline{\mathrm{x}}$_Post = 4.38±0.62, p < 0.01), muscle innervations ($\overline{\mathrm{x}}$_Pre = 2.94±1.00 vs $\overline{\mathrm{x}}$_Post = 4.31±0.48, p < 0.01), and key relationships ($\overline{\mathrm{x}}$_Pre = 3.25±1.18 vs $\overline{\mathrm{x}}$_Post = 4.44±0.51, p < 0.01). Residents also reported increases in their confidence with likely ability to identify anatomical structures on illustrations ($\overline{\mathrm{x}}$_Pre = 3.25±1.00 vs $\overline{\mathrm{x}}$_Post = 4.56±0.51, p < 0.01), on cadavers ($\overline{\mathrm{x}}$_Pre = 3.06±1.00 vs $\overline{\mathrm{x}}$_Post = 4.56±0.51, p < 0.01), and on ultrasound ($\overline{\mathrm{x}}$_Pre = 3.63±0.96 vs $\overline{\mathrm{x}}$_Post = 4.47±0.64, p < 0.01). After the CRS, there was no significant change in residents’ perceptions that the CRS would improve their board scores ($\overline{\mathrm{x}}$_Pre = 4.56±1.03 vs $\overline{\mathrm{x}}$_Post = 4.88±0.34, p > 0.05) and clinical performance ($\overline{\mathrm{x}}$_Pre = 4.50±1.03 vs $\overline{\mathrm{x}}$_Post = 4.88±0.34, p > 0.05).

Post-Session Survey—Resident Reactions to the CRS

From March 2017 to March 2018, CRS resident participants completed a post-session survey only, which was identical to the post-session survey from the pilot. Results are reported in Table 3. No significant differences (p > 0.05) were found between CA1 and CA3 post-session responses. All residents held overwhelmingly positive views of the session, both in terms of its perceived value to their residency training and its impact on anatomical knowledge. The majority of residents (98%) found the CRS easy to understand ($\overline{\mathrm{x}}$=4.88±0.63) and would recommend it ($\overline{\mathrm{x}}$=4.90±0.62). After the session, residents also believed the CRS would improve their board exam scores ($\overline{\mathrm{x}}$=4.83±0.66) and their clinical performance ($\overline{\mathrm{x}}$=4.86±0.65). Moreover, 98% of residents agreed they “felt more confident” in their knowledge of nerve origins ($\overline{\mathrm{x}}$=4.62±0.73), muscle innervations ($\overline{\mathrm{x}}$=4.62±0.73), and key anatomical relationships ($\overline{\mathrm{x}}$=4.64±0.73), and 95% agreed they “felt more confident” in their knowledge of cutaneous innervations ($\overline{\mathrm{x}}$=4.63±0.76), after participating in the CRS. Regarding identification of anatomical structures using different learning media, 98% of residents reported feeling more confident with identifying structures on anatomical illustrations ($\overline{\mathrm{x}}$=4.69±0.72) and on cadavers ($\overline{\mathrm{x}}$=4.74±0.70), while 95% indicated they felt more confident with identifying structures on ultrasound ($\overline{\mathrm{x}}$=4.68±0.76) as a result of completing the CRS.

Table 3.

Post-session survey results of the cadaver review session

		Post-survey only (n = 26)		Overall (comparative + post only groups)
Survey themes		CA1 (n = 17)	CA3 (n = 9)	CA1 (n = 26)	CA3 (n = 16)	Total (n = 42)
Impact on self-reported confidence	I felt more confident in my knowledge of ____ after the CRS.
	Nerve origins	5.00 ± 0.00 (100)	4.33 ± 1.32 (88.9)	4.77 ± 0.43 (100)	4.38 ± 1.02 (93.8)	4.62 ± 0.73 (97.6)
		p = 0.17		p = 0.16
	Cutaneous innervations	5.00 ± 0.00 (100)	4.44 ± 1.33 (88.9)	4.77 ± 0.43 (100)	4.44 ± 1.09 (87.5)	4.63 ± 0.76 (95.2)
		p = 0.25		p = 0.26
	Muscle innervations	5.00 ± 0.00 (100)	4.44 ± 1.33 (88.9)	4.77 ± 0.43 (100)	4.38 ± 1.02 (93.8)	4.62 ± 0.73 (97.6)
		p = 0.25		p = 0.16
	Key relationships	5.00 ± 0.00 (100)	4.33 ± 1.32 (88.9)	4.77 ± 0.43 (100)	4.44 ± 1.03 (93.8)	4.64 ± 0.73 (97.6)
		p = 0.17		p = 0.24
	I felt more confident identifying nerves and associated structures on ____ after the CRS.
	Illustrations	5.00 ± 0.00 (100)	4.33 ± 1.32 (88.9)	4.85 ± 0.37 (100)	4.44 ± 1.03 (93.8)	4.69 ± 0.72 (97.6)
		p = 0.17		p = 0.15
	Cadavers	5.00 ± 0.00 (100)	4.56 ± 1.33 (88.9)	4.85 ± 0.37 (100)	4.56 ± 1.03 (93.8)	4.74 ± 0.70 (97.6)
		p = 0.35		p = 0.30
	Ultrasound	5.00 ± 0.00 (100)	4.44 ± 1.33 (88.9)	4.85 ± 0.37 (100)	4.40 ± 1.12 (80.0)	4.68 ± 0.76 (95.1)
		p = 0.25		p = 0.15
Perceived value	The gross anatomy knowledge I learned in the CRS will help me improve performance on ____.
	Clinical duties	5.00 ± 0.00 (100)	4.56 ± 1.33 (88.9)	4.96 ± 0.20 (100)	4.69 ± 1.01 (93.8)	4.86 ± 0.65 (97.6)
		p = 0.35		p = 0.30
	Board exams	5.00 ± 0.00 (100)	4.44 ± 1.33 (88.9)	4.96 ± 0.20 (100)	4.63 ± 1.02 (93.8)	4.83 ± 0.66 (97.6)
		p = 0.25		p = 0.21
	I found the CRS accessible and easy to understand.	5.00 ± 0.00 (100)	4.56 ± 1.33 (88.9)	4.96 ± 0.20 (100)	4.75 ± 1.00 (93.8)	4.88 ± 0.63 (97.6)
		p = 0.35		p = 0.42
	I would recommend the CRS to other anesthesiology residents.	5.00 ± 0.00 (100)	4.56 ± 1.33 (88.9)	5.00 ± 0.00 (100)	4.75 ± 1.00 (93.8)	4.90 ± 0.62 (97.6)
		p = 0.35		p = 0.33

All survey items used the same 5-point Likert scale: 5 = strongly agree, 1 = strongly disagree. Percentage of residents who agreed (4) or strongly agreed (5) with the statements is reported in parentheses

Free-text comments were received from 13 residents (31% of total participants) on the post-session survey. The free-text comments were uniformly positive and suggest the CRS was popular, appreciated, and relevant to APS clinical practice. After attending the CRS, one CA1 resident commented: “Extremely high yield, this truly helps me visualize the anatomy that I will be seeing with ultrasound. Incredibly helpful to see the brachial plexus for interscalene anatomy. Will actually use this tomorrow in the OR.” A CA3 resident remarked: “This is one of the most valuable learning experiences of residency. These sessions have directly affected the way I practice regional anesthesia. Our program is so lucky to have this!!!!!!!!”.

Discussion

The CRS was developed to integrate anatomy education with clinical training after APS clinicians felt that residents would benefit from additional teaching of the anatomy associated with the blocks. Post-session survey results over 18 months showed that residents overwhelmingly found the session to be easy to understand, would recommend it to peers, and believed completing the session would improve their future board scores and clinical performance (Table 3). Such a positive reaction can be viewed as satisfaction with the new training program, which represents Level 1 of the Kirkpatrick evaluation framework [15]. Monitoring participant reactions is important, since negative reactions have the potential to hinder learning, while positive reactions can help stimulate learning [15]. The results presented here demonstrate high satisfaction with the CRS, a new educational offering designed to enhance the existing APS rotation within the anesthesiology residency curriculum.

Feedback from the residents surveyed indicates they appreciated the cadaver-based format for the anatomy review. After completing the CRS, a CA3 participant stated “It was very helpful to see the anatomy in 3D/in person. It helped me to correlate the different ligaments/bones on ultrasound.” An informal poll of our residents showed that 22 out of 30 (73%) residents would prefer a cadaver-based anatomy review versus an online module, which is consistent with previous studies [16–18]. In a review of teaching practices, Estai et al. determined both students and experts preferred traditional cadaver-based anatomy because it is more “fit for purpose” in meeting the needs and learning outcomes of the future clinician [16]. Unlike digital anatomy, cadaveric anatomy provides tactile feedback, 3D interaction with preserved tissue planes, anatomical variations, and opportunities to practice spatial reasoning [16]. Particularly for regional anesthesia, experience with real 3D anatomy and spatial reasoning is of the utmost importance because application of PNBs requires movement of a needle in three dimensions [19]. As noted by Rizzolo et al., this training is best provided by cadaveric anatomy because even with incredibly faithful digital 3D renderings, the learner is still burdened with understanding a complex 3D subject through a 2D screen [17]. Furthermore, in-person sessions allow participants to emphasize areas of interest such as the anatomy related to a recent or upcoming procedure or a new block from a journal article, in addition to the core curriculum (see learning objectives, Table 1). For adult learners, self-directed learning in a meaningful context is especially powerful for promoting deep understanding and long-term retention.

While our residents appeared to enjoy the in-person and cadaver-based format of the CRS, survey results also show residents perceived the CRS to fill a gap in content knowledge. Both CA1 and CA3 resident cohorts reported low to moderate confidence in anatomical abilities before the CRS (Table 2). Residents at our institution participate on the APS in their first and third years of residency training, which is on average 6 years removed from their last gross anatomy class. In 1 year after a gross anatomy course, the average medical student had already lost 14.7%±11.7 of his or her anatomical knowledge [20]. Upon entering residency 3 years later, anatomical knowledge had declined even further to roughly 50% and continued to slowly decline throughout their careers unless actively retrieved [20, 21]. Our CA1 residents participated in the CRS halfway through their 4-week APS rotation, which is a mixture of hands-on learning of regional blocks pertinent to clinical workload. Our CA3s usually attended the CRS during their elective month on the APS after their CA2 year in sub-specialty training, which rarely involves RAPM. Our residents may have difficulty consolidating their learning in RAPM due to variations in clinical workload, which may further impact their knowledge and confidence in PNB-related anatomy. While residents can access a plethora of learning resources, the CRS provided an alternate way of presenting a learning experience that may fulfill the needs of the individual learner. Comparisons of pre-versus post-session survey responses showed significant increases in resident self-confidence across all domains of anatomical knowledge after participating in the CRS (Table 2), which suggests that the CRS was effective in addressing a knowledge gap.

At a national level, gross anatomy contact hours have been reduced in the medical school curriculum, leading to a growing concern in the medical education community that the teaching of gross anatomy has declined to potentially dangerous levels [22, 23]. A lack of knowledge with gross anatomy has been implicated as a major source of complications in surgery [24, 25]. Between 1990 and 2000, the Medical Defence Union of the United Kingdom found that 32% of all reported claims in general and vascular surgery were caused by “damage to underlying structures,” which Ellis believes stems primarily from a lack of anatomical knowledge [24]. Another study in 2008 attributed 29.6% of surgical complications to poor judgment, 29.3% to inattention to detail, and 22.7% to incomplete understanding of the problem [25]. It follows that technical procedures in anesthesiology would be similarly impacted by declining anatomy contact hours. The survey results presented here show that both resident cohorts reported low to moderate confidence in relevant anatomical abilities before the CRS, and that their perceived confidence improved significantly after the CRS (Table 2).

Having confidence alone is not necessarily a desirable attribute. A study conducted by Bowyer et al. suggests that residents are not always accurate when self-assessing, which can lead to misplaced confidence and mistakes [26]. Senior surgical residents were found to rate their anatomical knowledge and confidence in associated surgical skills significantly higher than scores given them by expert evaluators, who determined that 65–86% of the residents would not be successful without assistance [26]. However, an individual’s self-perceived confidence has been shown to have a strong relationship with actual knowledge and skills in that subject. In a study by Lufler et al. on fourth-year medical students involved in a near-peer teaching program, actual knowledge and self-perceived knowledge (i.e., confidence) of anatomy were found to be significantly positively correlated on both pre- and post-tests [27]. Similarly, Favazzo et al. found a significant positive correlation between microbiology knowledge and self-reported confidence among undergraduate microbiology students [28]. Additionally, Clanton et al. found a strong association between post-training ratings of self-confidence from medical students and their surgical skills assessed by experts [29]. Having appropriate self-confidence allows a resident to seek out opportunities to demonstrate entrustable skills and develop autonomy [27–30].

In summary, the new CRS supplement to the APS rotation in the anesthesiology residency program was well-received, perceived as beneficial to improving confidence with a range of relevant anatomical topics, and perceived as beneficial to improving future board scores and clinical performance. At our academic medical center, with a gross anatomy laboratory and willed body program, and local expertise in anatomy and dissection, it was feasible and cost-effective to offer a monthly cadaver review session on-site. The cost of conducting the CRS at our institution is outlined in Table 4, and includes the procurement, dissection, and maintenance of a cadaver, supplies, as well as the professional time of an anatomist. The monthly sessions serve approximately 30 CA1 and CA3 residents annually during the APS rotation (in addition to other interested individuals), which amounts to a per-resident cost of $227.50 per year. This cost is lower than the costs of attending anatomy-focused workshops offered through national organizations. An Internet search for cadaver-based RAPM courses brings up multiple 1- or 2-day courses for approximately $1000 +, which does not include travel, accommodation, other per diem costs, or the time off to attend the event. Residents can more easily attend this monthly on-site opportunity, compared with the more logistically and financially demanding off-site workshops.

Table 4.

Costs of the cadaver review session (2 years)

Item	Cost
Cadaver	$1900
Anatomy lab fee	$100
Supplies (gloves, dissection tools, towels and bags, preservation solution)	$250
Dissection fee*	$3000
Anatomist fee (teaching, preparation, supervision of student dissectors, weekly care/maintenance of cadaver and anatomy workstation)	$8400
Total (every 2 years)	$13,650

Approximate breakdown of costs for offering the Cadaver Review Session at our institution for 2 years. Note that all fees and costs are institution-specific and should be negotiated with appropriate local representatives and departments. We paid graduate students enrolled in a master’s degree in anatomy at our institution to complete the dissections of pre-determined regions. The rate is $20/h, and dissection time is approximately 75 h per side. To maximize preservation of the cadaver, one side was dissected each calendar year. The State Anatomical Board of Colorado requires that cadavers be returned for cremation within 2 calendar years

This study demonstrates that anesthesiology residents rotating through the APS feel they can derive great benefit from the integration of gross anatomy into the residency curriculum using a complementary review activity such as the CRS. The CRS, originally designed to add an extra dimension to resident training, has proven more popular than expected. Multiple residents have attended the sessions in addition to their required program training, and both attendings and fellows from our pediatric program and VA hospital have also participated, as well as rotating students in medicine, anesthesiology assistant and nurse anesthetist training programs.

Limitations

During the CRS trial period (March to August 2017), resident perceptions were only collected verbally as anecdotal feedback due to the continuously evolving status of the CRS. As a result, comparisons of resident perceptions between the early CRS iterations and the current CRS are not possible. Moving forward, resident feedback for the CRS and its future iterations will continue to be collected formally through the post-session online survey for further analysis and improvement.

Additionally, because of the monthly rollout of the CRS as part of on-going RAPM training, the residents who participated in the CRS did so at different stages of their training (CA1 and CA3) and at different times across the year (e.g., month 1 vs month 12 of any residency year). This introduces some variability in the level of clinical and related anatomical knowledge in the participant pool. Combined with the small number of monthly resident participants, we opted not to collect baseline knowledge data.

The study asked all residents who participated to rate their confidence in seven domains of gross anatomy. All participants reported an improvement in confidence regarding their knowledge after attending the CRS (Table 3), but an actual improvement in anatomical knowledge, in the short or long term, was not assessed in this study. Residents already experience a high burden of testing throughout their training, and given the potential variability in our participants’ clinical and anatomical knowledge due to their different stages of training, we prioritized the limited time reserved for the CRS to providing a high-quality active learning experience rather than completing another set of assessments.

Conclusions

This study has shown that the longitudinal integration of gross anatomy into the graduate medical curriculum at our institution is highly popular and improves residents’ confidence in their ability to understand the anatomy during RAPM training. The incorporation of regular cadaver-based anatomy reviews during residency training can be relatively inexpensive and accessible at an academic medical center. Cadaver review sessions can be a worthwhile addition to an already full residency training experience in anesthesiology.

Compliance with Ethical Standards

Conflict of Interest

The authors declare that they have no conflicts of interest.

Ethical Approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institution (Colorado Institutional Review Board, ID# 17-1427) and with the 1964 Helinski declaration and its later amendments or comparable ethical standards.

Informed Consent

Informed consent was obtained from all individual participants included in the study.