Colleges of veterinary medicine have an obligation to provide veterinary students a curriculum that includes training in a variety of technical and nontechnical (eg, business and communication) skills. Balancing these requirements is challenging, and in many programs, surgical skills training may lose footing. However, veterinarians in private practice have indicated that general and elective surgical skills are among the most important skills new graduates should possess.1,2 Given this, it is imperative that CVMs train their students in basic surgical skills in preparation to meet the needs of hiring practitioners.3–6 However, surgical skills can be difficult to teach, and the best methods for evaluating students for competency in surgical skills are unclear.7–9 Furthermore, there is little evidence on what constitutes adequate practice time to meet the needs of students and the expectations of future employers.
In many CVMs in the United States, OHE of a dog or cat is the first live-animal surgery a veterinary student performs. Ovariohysterectomy is a complex surgical procedure that requires understanding of and proficiency in many component skills, including familiarity with handling surgical instruments, aseptic technique, basic suturing skills, entering a body cavity safely, and ligating vessels,10,11 making it an excellent training procedure for veterinary students.
Unfortunately, the best way to prepare veterinary students for their first live-animal surgery has not been well-defined, although it is known that the emotions—positive or negative—students experience while performing their first live-animal surgery can have an effect on motivation, learning, and memory.12 In a study12 of veterinary students undergoing their first live-animal surgery, the main source of positive emotions was an ability to practice and prepare well beforehand, whereas the main source of negative emotions was a lack of self-confidence.
Preclinical skills laboratories have been shown to increase student confidence and decrease student anxiety when performing these skills in context,13,14 and research has shown that to effectively learn a complex surgical procedure, such as OHE, the procedure should be deconstructed into its component skills.15–20 Learning component skills independent of the whole procedure has been shown to improve task performance,15,17–22 and there is increasing evidence that simulation, repetition, and frequent feedback are important for clinical skill development.15,17,20
In 2009, the Washington State University CVM restructured its surgical skills curriculum to introduce students to basic surgical skills and knowledge earlier in their training and provide opportunities for students to individualize their learning efforts on the basis of their own circumstances, goals, and learning styles. As a part of this, the CSST course was moved to the fall semester of the first year of the veterinary curriculum (from the spring semester of the second year). In addition, beginning in the spring semester of 2011, an OCSL was implemented to strengthen students' conceptual and technical knowledge of surgical principles and skills and allow for consistent self-driven practice in preparation for live-animal surgery.23
Quantifying the impact of curricular changes is challenging, particularly for complex tasks such as surgery. From a hiring practitioner's point of view, the time it takes new graduates to complete an OHE is an important measure of surgical skills proficiency. Unfortunately, to date, there are no clear guidelines for new graduates to measure themselves against when it comes to time to complete common surgical procedures such as OHE.
The present study was designed to determine the impact of the revised surgical skills curriculum on performance of veterinary students during their third-year surgery course. Specifically, the purpose of the study reported here was to determine total surgery time and incision closure time among veterinary students performing OHE of a dog during the third-year surgery course and to determine whether participation in the OCSL was associated with shorter times.
Materials and Methods
Data for veterinary students from the classes of 2012, 2013, and 2014 at the Washington State University CVM were used in the study. An OCSL was offered to students in all 4 years of the veterinary curriculum beginning in the spring semester of 2011. Students in the 2012 class, therefore, did not have access to the OCSL prior to their third-year surgery course, students in the 2013 class had access to the OCSL during spring semester 2011 (4 laboratory sessions were offered), and students in the 2014 class had access to the OCSL during spring semester 2011, fall semester 2011, and spring semester 2012 (weekly laboratory sessions were offered during fall semester 2011 and spring semester 2012). Also, when the CSST course was moved from the second to the first year of the curriculum, the laboratory portion of the course was decreased from six 3-hour laboratory sessions during the semester to six 2-hour sessions. Students in the 2012 class completed the CSST course during the second year of their training; students in the 2013 and 2014 classes completed the CSST course during the first year of their training.
Students in all 4 years of the veterinary curriculum were permitted to make use of the OCSL.23 Attendance at OCSL sessions was voluntary, and sessions were scheduled at times during the week that did not conflict with core curriculum courses. During OCSL sessions, students could practice whatever surgical skills they desired. Practice models, surgical instruments, suture material, and cadavers were provided. Laboratory sessions were 3 hours long, but students could come and go as they pleased. Attendance was tracked with a sign-in sheet. During spring semester 2011, laboratory sessions were supervised by a board-certified surgeon who was available to answer questions and provide feedback; during subsequent semesters, sessions were supervised by student TAs (generally, second- and third-year veterinary students), although a board-certified surgeon was also available to answer questions and mentor the student TAs as needed.
At the time of the study, all veterinary students at the Washington State University CVM were required to take and pass a junior surgery course during the third year of their curriculum. Students performed an OHE on a dog from a regional animal shelter during the course and were required to pass an oral and practical skills examination before they were admitted into the course. Students in the course were assigned to groups of 3 students each and rotated roles as primary surgeon, assistant surgeon, and anesthesiologist. In addition, students were assigned to blocks (A through D) of 3 to 4 weeks' duration and performed the OHE during their assigned block.
For each student, total surgery time and incision closure time were recorded when the student acted as primary surgeon. Total surgery time was defined as the time from the start of the skin incision to the placement of the last skin suture. Incision closure time was defined as the time from placement of the first suture in the body wall to placement of the last skin suture. Times were recorded by the student acting as the anesthesiologist during the surgery.
Additional information that was gathered for each student included the number of previous OHEs performed on dogs and cats, number of OCSL sessions attended, and whether the student was enrolled in the Applied Anatomy course (an elective course that students could take during the fall semester of their third year and that included extensive clinical skills training). During the initial part of the study, the number and type of complications encountered during the OHE procedure were recorded. However, because this information was not consistently recorded, these data were eliminated from the study.
One-way ANOVA followed by Scheffe all-pairwise comparison tests was performed to compare total surgery time and incision closure time between classes. For the classes of 2013 and 2014, linear regression was used to test whether number of OCSL sessions attended differed significantly between classes, and linear regression was used to test, for each class separately, whether total surgery time or incision closure time was associated with number of OCSL sessions attended. Finally, t tests were used to determine, for students in the classes of 2013 and 2014 separately, whether total surgery time differed between males and females, between students with or without previous experience performing OHE, or between students who were or were not enrolled in the Applied Anatomy elective course. A 1-way ANOVA was used to detect any difference in times between students in blocks A and B (ie, students who performed an OHE early in the semester) versus students in blocks C and D (ie, students who performed an OHE later in the semester). All analyses were performed with standard softwarea; values of P < 0.05 were considered significant.
The Washington State University Office of Research Assurances determined that the study satisfied the criteria for exempt research. All cadavers used in the OCSL sessions had been euthanized in accordance with AVMA and Institutional Animal Care and Use Committee guidelines. No animals were euthanized solely for the purposes of the OCSL, and no animals were euthanized at Washington State University.
Results
One student from the class of 2014 operated on a dog that had previously been spayed, and data for this student were removed from the analysis. In addition, data were missing for 4 students in both the class of 2013 and the class of 2014. Thus, data were available for 97 students in the class of 2012 (ie, students who had no access to the OCSL prior to their third-year surgery course), 93 students in the class of 2013 (ie, students who had access to 4 OCSL sessions during spring semester 2011), and 91 students in the class of 2014 (ie, students who had access to 4 OCSL sessions during spring semester 2011 and to weekly OCSL sessions during fall semester 2011 and spring semester 2012).
Total surgery time for students in the class of 2012 (mean, 144 minutes; range, 85 to 220 minutes) was not significantly (P = 0.27) different from total surgery time for students in the class of 2013 (mean, 136 minutes; range, 80 to 222 minutes). However, total surgery time for students in the class of 2014 (mean, 118 minutes; range, 65 to 200 minutes) was significantly (P < 0.001) shorter than times for students in the other 2 classes. Incision closure time for students in the class of 2012 (mean, 54 minutes; range, 15 to 94 minutes) was identical to that for students in the class of 2013 (mean, 54 minutes; range, 25 to 90 minutes). However, incision closure time for students in the class of 2014 (mean, 41 minutes; range, 15 to 70 minutes) was significantly (P < 0.001) shorter than times for students in the other 2 classes.
Number of OSCL sessions attended was significantly different between the classes of 2013 (mean, 1.15 sessions; range, 0 to 4 sessions) and 2014 (mean, 4.9 sessions; range 0 to 30 sessions). For students in the class of 2013, number of OSCL sessions attended was not significantly (P = 0.94) associated with total surgery time or incision closure time. However, for students in the class of 2014, number of OCSL sessions attended was significantly associated with both total surgery time (P = 0.003; r2 = 0.097) and incision closure time (P = 0.021; r2 =0.059), with times decreasing as number of OCSL sessions attended increased (Figure 1).
Scatterplot of total surgery time for students in the Washington State University CVM class of 2014 performing an OHE during their third-year surgery course versus number of OCSL sessions attended during the 3 semesters prior to the third-year surgery course. The solid line represents the linear regression line (P = 0.003; r2 = 0.097).
Citation: Journal of the American Veterinary Medical Association 248, 6; 10.2460/javma.248.6.630
Scatterplot of total surgery time for students in the Washington State University CVM class of 2014 performing an OHE during their third-year surgery course versus number of OCSL sessions attended during the 3 semesters prior to the third-year surgery course. The solid line represents the linear regression line (P = 0.003; r2 = 0.097).
Citation: Journal of the American Veterinary Medical Association 248, 6; 10.2460/javma.248.6.630
Scatterplot of total surgery time for students in the Washington State University CVM class of 2014 performing an OHE during their third-year surgery course versus number of OCSL sessions attended during the 3 semesters prior to the third-year surgery course. The solid line represents the linear regression line (P = 0.003; r2 = 0.097).
Citation: Journal of the American Veterinary Medical Association 248, 6; 10.2460/javma.248.6.630
For students in the class of 2013, total surgery times did not differ significantly (P = 0.432) between those who were or were not enrolled in the Applied Anatomy elective course. However, for students in the class of 2014, total surgery time for those enrolled in the Applied Anatomy course (mean, 110 minutes; range, 68 to 160 minutes) was significantly (P = 0.020) shorter than time for those not enrolled in the course (mean, 123 minutes; range, 65 to 200 minutes).
For both the 2013 and the 2014 classes, total surgery time was not significantly (P = 0.075 and 0.167, respectively) different between male and female students. Similarly, total surgery time was not significantly (P = 0.067 and 0.269, respectively) different between students with versus without previous experience performing an OHE on a dog or cat. For both classes, total surgery time was not significantly (P = 0.457 and 0.052, respectively) different between students assigned surgery blocks later in the semester (blocks C and D) versus students assigned surgery blocks earlier in the semester (blocks A and B).
Discussion
Results of the present study suggested that attendance in an OCSL was associated with improvements in surgical performance of veterinary students, as reflected in faster total surgery and incision closure times while performing an OHE during the third-year surgery course. Taken together, the findings indicated that the OCSL was an effective addition to the surgical skills curriculum.
A previous study24 found that mean time for third-year veterinary students to complete their first OHE was 145 minutes, which was consistent with total surgery times of 144 minutes for students in the class of 2012 and 136 minutes for students in the class of 2013 in the present study. Implementation of the OCSL was associated with significantly faster times, with a significant decrease in total surgery time for students in the class of 2014 (mean, 118 minutes), who had access to OCSL sessions for 3 semesters prior to their third-year surgery course. Because student participants were blinded to their role in the present study and were not actively made aware of their surgical times, we believe that the potential for bias was minimized and that the significant decreases in total surgery and incision closure times represented a true effect of the change in curriculum.
During individual OCSL sessions, students were allowed to practice any surgical skills they desired, but time to complete those skills was not emphasized. Rather, students were encouraged to practice for accuracy while learning foundational skills, as hurried and unfocused practice can lead to deficits in foundational skills.15,18 Because time was not an explicit focus of any aspect of the students' surgical skills training, we believe that differences in times between classes represented increases in efficiency and proficiency.
One finding of the present study was that maximum total surgery time for students in the class of 2014 (200 minutes) was approximately 10% shorter than maximum times for students in the classes of 2012 (220 minutes) and 2013 (222 minutes). This suggested that as a result of access to the OCSL, component skills were further developed even among those students in the class of 2014 who needed the most time to complete their first OHE.
Improving clinical performance can be difficult, and the lack of linear improvement as a function of practice time can be a source of frustration. Learning curves for technical skills are typically sigmoidal,25 with little initial improvement despite extensive practice, followed by a period of faster improvement as students are able to build on individual skills. In the present study, students in the class of 2012 did not have a structured outlet for focused practice beyond the traditional classroom blocks and therefore entered the third-year surgery course at the base of the learning curve. However, students in the class of 2014, even though they spent less time in laboratory sessions during the CSST, compared with students in the class of 2012, had access to the OCSL for 3 semesters prior to beginning their third-year surgery course. We speculate, therefore, that students in the class of 2014 had moved past the initial learning plateau by the time they entered the third-year surgery course and were able to use their learned component skills in the context of a complete procedure more effectively and efficiently. The OCSL provided students an opportunity to practice component skills, potentially allowing them to overcome the initial learning plateau earlier in their careers and possibly leading to greater gains during their training program.18,26
Although students in the class of 2012 likely practiced their surgical skills at home prior to the third-year surgery course, unsupervised practice may lead to errors and entrenchment of bad habits. In contrast, the supervised format of the OCSL provided targeted, immediate feedback, allowing students to know whether their skills were satisfactory and identify areas in need of improvement.27 In this way, knowledge and skill could be refined before students moved onto learning more challenging skills or began to integrate skills into procedures.15 To provide adequate feedback, particularly during early skill development, it is crucial that there be a low student-to-instructor ratio, which may be difficult to obtain in formal instructional laboratories.28 The OCSL provided an environment with unobtrusive supervision and feedback that steered students toward development of fundamental skills.16,23
The authors realize that the present study represented a single surgical procedure performed early in the course of students' veterinary careers and that time is not the only important surgical outcome. Nevertheless, we believe our results provided evidence of the benefits of student access to the OCSL. The next step in evolving the OCSL is to find ways to allow students unlimited repetition of complex surgical procedures. Repetition is an important learning principle that moves students further up the learning curve and allows for exposure to more complex scenarios, such as anatomic variations, complications, and variations in incision size. This could potentially be accomplished by developing models (low-fidelity versions and virtual reality programs) and expanding spay-neuter clinics.
The effects of practicing component skills versus performing entire procedures on competence in surgery are unclear. For both the 2013 and 2014 classes in the present study, total surgery time was not significantly different between students with versus without previous experience performing an OHE, suggesting that previously performing the entire procedure did not reduce surgery time. In contrast, students in the class of 2014 as a whole had significantly shorter surgery times than did students in the class of 2013. It could be argued that students in the class of 2014 were able to acquire competency in component skills through attendance at OCSL sessions and subsequently efficiently integrated them when performing their first OHE.
Although the OCSL had a significant impact on both total surgery time and incision closure time in the present study, individual times were highly variable, reflecting individual student differences in confidence, risk tolerance, and previous exposure to surgery. In addition, for students in the class of 2014, enrollment in the Applied Anatomy course was associated with decreased surgical times. The Applied Anatomy elective course included hands-on laboratory sessions that highlighted basic and more advanced surgical procedures with in-the-moment performance feedback.
Factors related to the third-year surgery course itself could also help account for individual variability in surgery times, such as number of check-in points during the surgery, experience of the supervising clinicians, and occurrence of complications. Many students assigned surgery blocks earlier in the semester (blocks A and B) were not enrolled in the Applied Anatomy course, whereas most of the students assigned surgery blocks later in the semester (blocks C and D) were, and this may have confounded our results. Students in block A, who performed their OHEs at the beginning of the semester, reported that there were more required check-ins by a clinician during surgery (up to 8 separate steps), potentially prolonging surgery time, as clinician approval was required before proceeding with the surgery. By comparison, students in block D reported as few as 3 check-ins during surgery. Given these findings, programs that endeavor to use OHE outcomes as a metric of curriculum performance may want to consider the value in greater standardization.
Additional limitations of the present study should be considered. For example, attendance at OCSL sessions was determined from the student sign-in sheets, which may not have been reliable. Also, the sign-in sheet did not track the specific amount of time each student spent practicing or the quality of effort expended. The retrospective design of the study limited our ability to assess associations between total surgery time and OCSL attendance for the classes of 2012 and 2013. Also, the surgical skills curriculum changed in more than 1 aspect during the time of the study, making it difficult to draw absolute conclusions. Nevertheless, our data appeared useful in identifying important trends. Comparisons of the classes of 2013 and 2014 may be more reliable, in that the curriculum did not change as drastically. Also, total surgery times for the classes of 2012 and 2013 were closely aligned with times reported from a different institution,24 indicating times reported here may be a useful baseline for students performing their first live-animal OHE.
Although the shorter surgery times for the class of 2014 in the present study were encouraging, further monitoring is indicated to determine whether there will be a long-term impact on proficiency. Surgical time was chosen as the factor of interest because it is easily measured, but performing a surgery quickly and performing a surgery competently are not necessarily the same thing. Other factors associated with competence should also be measured, including complication rate, complexity of the procedure (eg, prepubescent vs pregnant animals), and anxiety levels of students performing the procedure. Additional measures of surgical skill could include appearance of the closure, ability to isolate the uterus and ligate the pedicles, and severity of postoperative pain or incisional bruising. Although the authors believe that self-confidence affects students' ability to handle the stress of their first live-animal surgery competently, total surgery time is not necessarily the most accurate measure of that variable. Students were able to improve their confidence by practicing their skills in the OCSL, thus gaining greater familiarity with instrument handling, suture patterns, and basic hemostasis. A study assessing self-assessed stress levels before and after practice and surgery could provide important insights into student confidence. Finally, complication rates and surgical difficulties should be monitored through consistent, accessible, and detailed record keeping.
In the present study, access to an OCSL was significantly associated with decreased total surgery and incision closure times for students performing an OHE during their third-year surgery course. Students who are competent in surgical skills will likely perform better in working interviews, will likely be better able to find employment following graduation, and will likely be more profitable to their employers. Allowing students opportunities to practice their surgical skills in a low-stress, controlled environment is something that all CVMs can incorporate into their curriculum.
Acknowledgments
Pilot data were presented in abstract form at the International Veterinary Simulation in Teaching conference, Calgary, AB, Canada, August 2012
The authors thank Drs. Bonnie Campbell and Bill Dernell for technical support.
ABBREVIATIONS
| CSST | Compulsory surgical skills training |
| CVM | College of Veterinary Medicine |
| OCSL | Optional clinical skills laboratory |
| OHE | Ovariohysterectomy |
| TA | Teaching assistant |
Footnotes
Statistix, version 9.0, Analytical Software, Tallahassee, Fla.
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