Setting up a Neurosurgical Skills Laboratory and Designing Simulation Courses to Augment Resident Training Program
Correspondence Address: Source of Support: None, Conflict of Interest: None DOI: 10.4103/0028-3886.344633
Source of Support: None, Conflict of Interest: None
Keywords: Cadaver training, resident training, skills laboratory, surgical skills
Training in neurosurgery aims at imparting clinical knowledge as well as the highest levels of surgical skills to deal with a wide spectrum of disorders of the brain and spine. The traditional surgical training was based on the Halstedian principle of the apprenticeship model. In the current era, several modifications have been made in the resident teaching curriculum considering patient safety, duty time limitations, medico-legal issues, and the number of residents posted in the operating theater (OT)., This may compromise their surgical skills and they may lack confidence by the time they finish their residency program. Simulation training outside the OT is helpful for the residents to learn surgical anatomy operative steps. Therefore, training in the skills laboratory is becoming an essential part of the modern neurosurgery resident teaching program.,, Such a laboratory should simulate the OT and must be equipped with the necessary surgical armamentarium. At present, there are only a few neurosurgery departments in India equipped with skills training center facilities., Such simulation training has not been included in the neurosurgery teaching curriculum in our country. The Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, has one of the largest referral neurosurgery centers in northwest India. A surgical skills lab was established at the Department of Neurosurgery, PGIMER, Chandigarh, in 2018, which is the first of its kind in this region to improve surgical training of the neurosurgery residents.
In this paper, we have discussed our experience in establishing this neurosurgery skills laboratory. A training course has been formulated with simulation practice modules and cadaveric dissection modules for the neurosurgery residents.
The surgical skills laboratory setting
The skills lab was funded by the institute. The existing resident teaching hall with an area of 500 square meters was utilized for setting this 'in-house laboratory.' Nine skills stations were organized at the periphery of the hall with three on each side. Approximately, a 20 square meter space was utilized to set one skill station with adequate space between the stations. A central screen was placed in the front wall for the projection of the operative techniques being performed on the master table. The skills lab practice for neurosurgery residents was approved from institutional ethical committee,PGIMER on 19.03.2019.
Every station is equipped like the OT with a table, operating microscope, endoscope, high-speed electric drill, vacuum suction machine, and a set of microsurgical and endoscopic instruments [Figure 1]. Each station has a separate screen, adjacent to the table, projecting the operating view from the microscope/endoscope. As the skills stations were located at the periphery of the hall, the central space with a seating capacity of 50 was also utilized for the daily resident teaching purposes.
The table is compact with a small base and fixed height which is a stationary unit. However, the surgeon's chair has a rotating base and facility for height adjustment to work ergonomically. An adjustable pin-based head holder system and bone fixators are available at each station so as to mount the module/cadaveric head and cervical spine on the table. The table and fixators are custom-made at a low cost.
Each station is equipped with an HS Hi-R-700 microscope (Moller Wedel), having a compact, rollable 360-degree floor stand, and a 1:6 zoom ratio, motorized magnification lens system 1.5X to 15X. The working distance is 200–400 mm, and the handgrips have buttons for motorized focus, zoom, illumination, and electromagnetic brakes. This is a basic model without assistant port and advanced adjuncts.
A Karl Storz endoscope (zero degrees 4 mm internal diameter and 18 cm length) with full high-definition (HD) three-chip camera head and xenon light system is attached with each table. These are the basic endoscope without an additional port for endoscopic instrumentations. There is a 26-inch monitor with a recording system connected with each endoscope.
One high-speed electric drill with multiple attachment systems (Aesculap) is placed at each station. Drill bits both cutting and drilling variety are made available to be used as per the surgical procedure.
A mobile suction system with a 2 L × 5 L canister and vacuum up to − 98 kPa is also kept at each station.
A separate wet laboratory room is set outside the main hall with a washbasin for cleaning the used instruments. We have collaborated with the Department of Anatomy for getting donated cadavers and embalmed and appropriately stored.
Cadaver fixation process
Preservation of the cadaveric heads for skills lab training has three end goals— the tissue should be fixed to arrest decomposition, be non-infectious, and provide a lifelike learning experience. The first two goals are fully achieved by conventional embalming. The embalming fluid contains formalin and ethanol which fix the tissue, and along with phenol and thallium crystals act as a disinfectant and keep the tissue safe for handling. But at the same time, formalin also causes tissue shrinkage and hardening, which changes the haptic properties of the tissue, thus compromising the optimal surgical training. In order to improve the degree of realism in surgical simulations, modified embalming fluid was used to embalm the cadavers for a surgical skills lab. The ratio of formalin, alcohol, phenol, and glycerin was modified so that the end result was fixed safe cadavers with a near-lifelike texture and mechanical properties. Moreover, our modified embalming technique leads to better preservation of the tissue planes ensuring fidelity in surgical simulation. The preservation was excellent so that we were able to repeatedly use the same cadaveric heads for different procedures and maximally utilize them.
The duration of the neurosurgery residency program at PGIMER is for 36 months as per the institution's protocol. Every 6 months, a new batch of residents join this training course. A graded training program was planned where the junior trainees were taught about the basics of instrument handling on non-cadaver modules and senior trainees were allowed to practice on cadaveric modules. The residents in their initial three semesters were grouped for non-cadaveric simulation practice (microneurosurgery, high-speed drilling, and essential neuroendoscopy). Similarly, the surgical skills practice on the cadaver was designed for residents beyond the third semester. This included conventional craniotomies and approaches through various corridors. For ease of preparation, alternate Sundays were scheduled for non-cadaveric simulation course and cadaveric training, respectively. This skills lab was also used for conducting several cadaveric workshops where resident and junior faculty from other institutions got an opportunity for hands-on practice. At the end of 1 year of skills practice, feedback was obtained from the trainees in a blinded manner.
Non-cadaveric simulation procedures
Microvascular anastomosis on chicken wings was practiced for learning microneurosurgical skills [Figure 2]a. The specimen was fixed on a paraffin tray. Under an operating microscope, the brachial artery (BA) was first defined using sharp dissection and followed distally. The two divisions radial (RA) and ulnar (UA) were also dissected. The RA was cut and an end to side anastomosis using interrupted suturing technique between the RA and BA was performed. The suturing was started at the toe then the heel of the graft followed by the posterior and anterior wall. Then, the anastomosis was examined for spacing between the sutures for any kinking and patency of the anastomosis.
The residents were allowed to practice the surgical procedure for the next 2 h. The entire session was supervised by a senior faculty member.
After demonstrating the technical aspect of the electrical drill, the residents were taught to perform drilling on eggshell and sheep scapula [Figure 2]b and [Figure 2]c. In the initial two sessions, eggshell drilling was practiced to have control over the high-speed drill system. Any image/name was asked to draw by drilling over the eggshell without violating the inner amniotic membrane. Later on, various drilling maneuvers were practiced on the sheep scapula after fixing it on a bone fixator to stabilize the specimen.
In this session, the trainees were taught to handle the neuroendoscope, light source, and allowed to assemble the endoscopic instruments. A zero-degree scope is used for visualization inside the capsicum. The removal of capsicum seeds with endoscopic guidance was practiced [Figure 2]d. Endonasal anatomy and ventricular anatomy were demonstrated on sectioned plastic models procured for the lab [Figure 3].
Surgical training on cadavers
The cadavers were arranged by the Department of Anatomy. The residents were advised to maintain dignity in the skills lab similar to that in the OT and handle the cadavers respectfully. A single cadaver head was used for performing all possible types of craniotomies in different sessions. The residents were asked to perform the respective surgical procedures with the use of microsurgical instruments available in each station under the guidance of a faculty member. The operative site was then sutured properly and the cadaver head was handed over to the anatomy department for storage and reuse in a separate session.
Non-cadaveric simulation practice
Eighteen residents in three groups had participated in this program for the academic year 2019–2020. Each group attended three sessions of microvascular anastomosis, high-speed drilling, and neuroendoscopy. In two sessions, end to side and end to end microvascular anastomosis on the chicken wings were practiced. During the high-speed drilling session, hand stabilization skill was imparted on eggshell drilling. In the latter two sessions, bony drilling was carried out on sheep scapula, while preserving the underlying structures (simulated by rubber bands) [Figure 2]c. Hand-eye coordination was emphasized during the endoscopic removal of capsicum seeds. At the end of three sessions, all the residents learned to assemble the entire endoscopic system independently.
Surgical training on cadavers
Twenty-six residents participated and 12 sessions were conducted in the cadaveric training session during the academic year 2019–2020 [Table 1]. Complete 10 sets of cadavers were used for this training. Two residents did the dissection practice at each station and everyone got the opportunity to perform the craniotomy and tissue dissection under the operating microscope independently [Figure 4]a and [Figure 4]b. The operative images were then stored and properly labeled for resident teaching classes [Figure 5] and [Figure 6].
Workshops and national activities
Three cadaveric workshops (craniovertebral junction surgery, expanded endoscopic endonasal procedure, and open-skull base procedure for petrosectomy and clinoid drilling) were conducted during this period. Senior faculty from other national institutes were also invited as demonstrators. All these programs were updated in the website of the National Neurosurgical Society so that the trainees from the other neurosurgical centers got an opportunity to participate. In each session, 20 residents and junior faculty from 5 other institutions participated in the hands-on workshop. Four senior faculty from other institutions participated after getting approval from their parent center. After demonstrating the scheduled procedure, they actively interacted with the trainees and discussed the operative nuances. A majority of the trainees did not have experience of skills lab hands-on practice before. The residents and junior faculty from the other institutes suggested to conduct a structured regular cadaveric hands-on training course, as a majority of neurosurgical centers lack such skills lab facility.
The response from 25 residents was obtained at the completion of 1 year of the training program [Table 2]. The skills lab training sessions were helpful for all the residents to understand the surgical anatomy and also provided an opportunity to get familiar with the neurosurgical instruments. Everybody was of the opinion that this skills lab practice should be an essential part of the neurosurgery resident training program.
In recent times, the diversification of the neurosurgical sub-specialties, the increasing expectations of outcome from the community, medico-legal concerns, and work-hour reforms among the trainees have, however, impacted the training models among the neurosurgical residents. Again, the residents must practice the surgical steps repeatedly in a sequential manner under the supervision of a senior faculty to attain optimum operative skills. Henceforth, the surgical skills training in the lab is rapidly becoming a vital aspect of the training program for resident doctors.,
However, such skills labs are not common in developing countries due to financial constraints. A lecture theater or resident classroom space can be utilized for setting an 'in-house lab' with limited stations, thereby, avoiding the need for a separate building. The instruments previously used in the OT can be used for skills practice in the laboratory. Wherever possible, infrastructures like tables, chairs, and fixators can be custom-made at a low cost. A basic microscope and endoscope with reasonably standard optics reduce the cost significantly without compromising the hand-eye coordination practice.
The cadaver storage facility is always a major concern for the surgical skills laboratory. This requires a completely separate technical team apart from other ethical challenges. The collaboration with the anatomy department can facilitate the proper utilization and storage of the cadavers. Wherever feasible, the Department of Neurosurgery must work coherently with the Department of Anatomy for the smooth running of the skills lab.
Several simulating modules can be used for skills practice at a very low cost like chicken wings, capsicum, and sheep scapula as practice modules, which are easy to procure and easy to use and reduce the recurring cost significantly. The use of jeweler's forceps, microscissors, ophthalmological microinstruments with gauge, and latex gloves as training modules have also been documented for low-cost simulation practice. Again, tissue dissection and vessel manipulation under a microscope simulate actual surgery to a great extent. The practice on the capsicum helped the trainees to hold the endoscope ergonomically and allowed them in achieving proper hand-eye coordination. These essential but straightforward surgical steps are most effective for the neurosurgery residents in the beginning. Therefore, we have designed these non-cadaveric simulation curriculums for the initial phase of residency.
The surgical training on animal models provides real hands-on practice. We are using chicken wings and sheep scapula as animal models where residents are allowed to learn basic instrument handling. Then the residents are graduated to practice on the cadaveric modules. We feel direct practice on the cadaver provides a more accurate experience like that in the OT. The surgical dissection practice on the cadavers is considered one of the best ways to learn complex procedures. Patient positioning and craniotomy are some of the most important steps that can be learned in the skills lab. Again, trainees get sufficient time to understand and practice complex craniotomies like single-piece fronto-orbito-temporo-zygomatic craniotomy and skull base procedures like clinoid drilling and petrosectomy. As each trainee gets the opportunity for an independent hands-on session, they can analyze their own mistakes and learn the technical nuances from the experts. Additionally, several toolboxes have been designed to objectively assess the technical skill of the trainee.,,, By this, the residents can recognize their weaker aspects and the skills lab provides a platform to repeatedly practice and improve their surgical skills.
The neurosurgery residency does not ensure uniform skill acquisition at the end of the residency. Therefore, it is the responsibility of the apex institutes where the skills laboratory facility is available to conduct cadaveric workshops periodically so that trainees from other institutes get equal opportunities to learn surgical skills. Such training sessions at regular intervals help to improve the surgical skills of the trainees and junior neurosurgeons. We are also planning to incorporate various advanced training modules with spinal instrumentation set in our skills lab training.
In the present scenario, a structured skills lab training program should be incorporated into the resident teaching curriculum to augment their operative skills. An in-house neurosurgery skills lab can be planned utilizing the regular classroom space. Further, using the basic microscope, endoscope, custom-made tables, chairs, and fixators significantly reduces the cost of setting these labs.
We are thankful to Mr Anil, Mr Rahul and Mr Navdeep for preparing the skills stations before each practice session.
Financial support and sponsorship
This study partly funded by intramural project sanctioned from PGIMER, Chandigarh, No 71/2Edu-2016/540. Dr Sushant kumar Sahoo as the principal investigator and Dr Sunil k Gupta as Co-principal investigator.
Conflicts of interest
There are no conflicts of interest.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]
[Table 1], [Table 2]