MICROSURGERY

An Economical Training Model to Teach and Practice Deep Inferior Epigastric Artery Perforator Dissection Matthew Nykiel, MD, Ryan Wong, MD, and Gordon Lee, MD Introduction: Modern surgical training has placed a larger focus on procedural competency base training for surgical specialties. Although various simulators are in existence to teach laparoscopic skills, plastic surgery has a paucity of surgical training models. Methods and Materials: We developed a low-cost teaching model for the steps and techniques required in the deep inferior epigastric perforator f lap and assessed the utility of this model with the resident surgeons using presurvey and postsurvey. Results: A total of 13 residents participated in the surgical skill exercise. The residents felt this exercise increased their proficiency in the steps and techniques required for a deep inferior epigastric perforator flap harvest [4 (0.4)]. Conclusions: Overall, residents felt this exercise should be included in the postgraduate years 1 and 2 educational curriculum. Key Words: microsurgery education, surgical education, medical education, perforator flap dissection, surgical techniques, DIEP flap, breast reconstruction, abdominal free flap (Ann Plast Surg 2014;72: S66YS70)

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he history of surgery has been dynamic with the field fluidly evolving alongside new technologies and ideas. However, training of surgical residents has been fairly regimented and constant. Traditionally, surgery has been taught as an apprenticeship model. Modern training still has elements of the apprenticeship model. However, training programs have to continually change to stay in compliance with the Accreditation Council for Governing Medical Education.1 These shifts have placed a larger focus on procedural competencyYbased training for the surgical specialties. At the same time, the increasingly stringent duty hour restrictions have further commoditized time; thus, making it more challenging to train residents in procedures and placed a premium on efficiency in education. Certain aspects of surgical education have been addressed by software, Web-based, and computer virtual training.2Y13 The best known is probably the minimal invasive surgery training program.14 The general surgery, urology, and obstetrics/gynecology residencies have embraced this program into their curriculum.15 Although various simulators are in existence to teach laparoscopic skills, plastic surgery has a paucity of surgical training models. As an initial step toward developing surgical teaching models for plastic surgery, we first developed a low-cost model of the abdominal wall to recreate the steps and techniques required in perforator dissection for a deep inferior epigastric perforator (DIEP) f lap. We then assessed the utility of this model and the extent to which the residents found it useful. Received March 2, 2010, and accepted for publication, after revision, September 2, 2010. From the Stanford University, Division of Plastic Surgery, Stanford, CA. Conflicts of interest and sources of funding: none declared. Reprints: Matthew Nykiel, MD, Stanford University, Stanford, CA. E-mail: [email protected]. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www.annalsplasticsurgery.com). Copyright * 2014 by Lippincott Williams & Wilkins ISSN: 0148-7043/14/7201-S066 DOI: 10.1097/SAP.0000000000000176

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METHODS Model Fabrication We created a model of the anterior abdominal wall through products found at a local craft store (Figs. 1Y3). We used foam board, yarn (crimson for muscle, red for arteries, blue for veins, and yellow for nerves), felt (brown for skin and yellow for subcutaneous fat), and a hot glue gun. The yarn was placed in multiple layers to represent the muscle fibers. The perforators were then woven through the muscle and into the deep inferior epigastric vessel. The models are created with the various vascular branching patterns that have been previously described in the literature by Rozen et al,16 as either having a single branch (type I), medial and lateral row (type II), or medial, intermediate, and lateral rows (type III). We then weaved the intercostal bundles into the muscle. The intercostal bundle was randomly anastomosed with the lateral row perforators. To recreate clinical scenarios, the intercostal vessels were also randomly the dominant vessel of individual lateral perforators. Finally, we intertwined the continuing intercostal bundles among the perforator row branch (type I, II, or III). This was done so residents could decide if the intercostal bundle needed to be divided for either exposure or isolation of the main vessel (Fig. 4).

Simulated Surgical Dissection We then developed an exercise for residents that simulates the actual surgical steps in perforator identification and dissection (Video 1, http://links.lww.com/SAP/A111). Essentially, the exercise involved elevating the ‘‘flap’’ from lateral to medial. Then, residents must identify the edge of the rectus muscle and the perforators. Next, residents isolate the main pedicle (deep inferior epigastric artery and vein) and trace the pedicle antegrade into the rectus muscle. The resident must decide which perforator(s) will support the flap based on the relative location and size. Residents then dissect the perforator(s) in a retrograde fashion toward the main pedicle. If a lateral row perforator is chosen, he/she must make sure that the perforator is not from an intercostal vessel.

Assessment of Model Utility To determine the need and the effectiveness of the model, a Likert scale (1Y5) presurvey and postsurvey was adopted from prior studies (Figs. 5 and 6) and was given to the residents using the model exercise.17,18 The presurvey asked the residents to evaluate if they felt there was a need for a model that emphasized operative techniques in f lap perforator harvest. The survey then went on to ask their perceived proficiency of local anatomy, knowledge of operative steps, and ability to perform the operation independently. The postsurvey had the residents rate the direct inf luence (negative or positive) that this exercise had on local anatomy, operative steps, and independently performing the operation.

RESULTS A total of 13 residents participated in the surgical skills exercise and assessment. Figures 7 and 8 display the results of the presurvey and postsurvey data. When examining the presurvey data, on average, the residents agreed [4 (0.9)] they needed to improve their knowledge of how to perform the operation. The junior residents (PGY 1Y3) did not feel they could independently perform a DIEP flap [2 (0.7)]. Annals of Plastic Surgery

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Training Model to Teach Perforator Dissection

FIGURE 3. DIEP model showing a lateral to medial view of the elevate ‘‘f lap’’ approaching the perforators. In addition the intercostal vessels, deep inferior epigastric vessels and rectus muscle are visible.

residents felt the model exercise improved their proficiency of the operative steps [4 (0.5) and 4 (0.8), respectively]. FIGURE 1. DIEP model showing anterior abdominal wall skin.

They also agreed that this model exercise would improve their proficiency in the operation [4 (0.8)]. The senior residents (PGY 4Y6) were more comfortable performing the operation independently the on their own [4 (0.8)]. As one would expect, the confidence to perform the operation independently increases with each PGY year. The small sample size limits the ability to calculate a meaningful P value and, therefore, the calculation was not done. The senior residents both participated and observed more than 15 DIEP f laps. When reviewing the posttest, the residents felt the exercise increased their proficiency in the DIEP f lap [4 (0.4)], the exercise was clear [4 (0.4)], easy to understand the format [4 (0.7)], did not require and excessive amount of time [2 [0.4)], and overall should be included in the curriculum of the PGY 1 and 2 resident training. The junior-level residents felt the exercise increased their anatomic knowledge of the abdominal wall [4 (0.8)], perforators [4 (0.8)], and intercostal vessels [4 (0.5)]. Both the junior- and senior-level

FIGURE 2. DIEP model showing lateral elevation with the intercostal bundle, deep inferior epigastric vessels, and illioinguinal ligament. * 2014 Lippincott Williams & Wilkins

DISCUSSION Performing a successful surgical operation contains many steps that need to be executed in the appropriate sequence. Teaching this skill to residents is not without challenges in the current educational environment. Issues with patient safety and the need for greater supervision to ensure patient safety does not allow for residents to practice on patients. Faculty are ultimately responsible for ensuring the patients achieve satisfactory outcomes, and at the same time teach surgical skills to trainees. In that regard, the use of surgical simulators has become an attractive method of training the next generation of surgeons. The ideal surgical simulator needs to be cost effective, replicate the surgical environment to make it as realistic as possible, and be readily accessible to faculty and trainees. Current models used in other specialties fall short of this idea. Many programs use cadaver dissection laboratories, but human cadavers are expensive, require appropriate facilities, and are in limited supplies. In perforator dissections, cadaver tissue is not similar to tissue encountered in live environment. Thus, it fails to reinforce the concepts and techniques in perforator dissections. Computer simulators can demonstrate graphical representations of operations, but do not allow the trainee to physically interact with the model as is so important when it comes to surgical procedures. Plastic or rubber prefabricated models of anatomic body parts are theoretically possible to create, but are costly to manufacture for a

FIGURE 4. DIEP model showing intercostal vessels giving partial contribution to a lateral perforator. Residents will need to ‘‘dissect’’ this bundle to visualize the full perforator and the lateral row branch. www.annalsplasticsurgery.com

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FIGURE 5. Preexercise survey.

FIGURE 6. Postexercise survey. S68

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FIGURE 7. Preexercise survey results.

FIGURE 8. Postexercise survey. * 2014 Lippincott Williams & Wilkins

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focused specialty. Despite the limitation of surgical simulation, the literature supports the concept that surgical models accelerate technical skills, translate from the laboratory or model environment to the clinical environment, and help to establish technically competent residents.15,17Y20 Given the positive impact on training, the Accreditation Council for Governing Medical Education and several subspecialties (General Surgery, Urology, and Obstetrics and Gynecology) have adopted procedural exercises into their residency curriculum. In fact, studies have been performed recommending that residency programs restructure their education to include procedure trainers.21 Unfortunately, to date, there does not exist standardized procedural trainers across the Plastic Surgery Residency programs in the country. A major drawback to some of the current models is the lack of fidelity in recreating the actual surgical environment and condition. Furthermore, these models may be cost-prohibitive for many institutions. Despite their inherent limitations, the usefulness of these models in other specialties has clearly been demonstrated.15,17Y20 We feel that there is a need in Plastic Surgery residency to have standardized procedural trainers that are cost effective and educational. Indeed, in our preliminary study, we found that residents universally perceived a need for procedural trainers, especially in perforator f lap dissections. Furthermore, we created 5 complete models for $30.00. This simple and cost-effective exercise was felt to be clear and helpful to the residents. The exercise increased the junior residents’ level of anatomic proficiency as a whole. More importantly, it helped to increase their understanding of the intercostal vascular anatomy. This is especially important when determining the source of blood supply to lateral perforators and the remaining blood supply to caudal ends of the remaining rectus abdominus. In addition, this exercise increased the junior- and senior-level residents’ proficiency of understanding the operative steps in the DIEP f lap and perforator dissection. As stated previously, there have been a number of studies that have shown that training modules allow the residents to increase their fine motor skills; however, unlike our training model, these models are complex and costly.15,17Y19,21,22 Overall, the cost-effective DIEP training module was well received by the residents. They found the exercise easy to follow, clear to understand, and helpful. Not surprisingly, the model had a greater impact on the junior residents (PGY 1Y3); where it increased the resident’s understanding of the anatomy of the abdominal wall, the vascular pedicle, specific perforator, and the intercostal vessels. In addition, both the junior and senior residents increased their proficiency in understanding and outlining the operative steps of the DIEP flap. As a whole, the residents felt this would be useful and should be included in the PGY 1Y2 educational curriculum. Our training module does have some limitations. The current prototype could be more realistic in design. This is a major area where we could improve the training. In the models current state, we believe this is a great adjunct when used with cadaver dissections. The cadaver allows for the realistic anatomical approach and the model allows reinforcement of the techniques required in perforator dissection in vivo.

training models and simulation exercises to teach and improve understanding of specific operations and techniques. We have created an economical model that is easy to use, clear to follow, and impacts the level of proficiency of the residents regardless of PGY level. Finally, after using the training module, the residents feel this exercise should be included in their PGY 1 and 2 curriculums to help explain the operation and the techniques required in the perforator flap harvest.

CONCLUSIONS

20. Wanzel KR, Hamstra SJ, Anastakis DJ, et al. Effect of visual-spatial ability on learning of spatially-complex surgical skills. Lancet. 2002;359:230Y231.

In summary, this was a pilot study to help elucidate if (1) there was a need in plastic surgery residency for procedural trainers/models and (2) to determine if an economical model could be developed that would positively impact the resident’s understanding of perforator operations and techniques. We believe, as seen by our resident’s surveys and when examining the literature, there is a need for procedural

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An economical training model to teach and practice deep inferior epigastric artery perforator dissection.

Modern surgical training has placed a larger focus on procedural competency base training for surgical specialties. Although various simulators are in...
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