An Affordable Neurosurgical Training System for Neurosurgical Residents; The Indian Perspective
Correspondence Address: Source of Support: None, Conflict of Interest: None DOI: 10.4103/0028-3886.304122
Source of Support: None, Conflict of Interest: None
Keywords: Microsurgery, microsuturing, neurosurgery, training
Neurosurgery as a discipline, has a steep learning curve. A curve that one may ascend with patience, determination, and most importantly practice. The importance of continued practice to improve one's dexterity under the microscope cannot be overemphasised and forms the cornerstone of improving microsurgical skills., Unfortunately, neurosurgical practice exercises require access to a sophisticated microscope and intricate instruments , which are well beyond the means of an Indian resident. Few institutes in India offer a skills lab for neurosurgical residents, other institutes are limited by the expenses involved with such an endeavor and the inherent logistics.
Authors in other countries have described cost-effective training systems,, however these cannot be readily applied to the Indian scenario as they involve locally sourced instruments and parts that are not readily available in our country. We have developed a system comprising of cost-effective tools that, in our opinion, readily simulate most neurosurgical exercises. We believe that this system may make neuro/micro-surgical training better available.
The aim of this study was to establish a sustainable, functional, and relatively inexpensive neurosurgical training system.
The components that we focussed on were a training microscope, microinstruments, training models, and the requirements for each training model.
Familiarity and hand–eye coordination under a microscope are an essential component of the neurosurgeons armamentarium. A training microscope usually requires a magnification of around 25Õ with a working distance of 200–300 mm. Most microsurgical microscopes, training or otherwise offer these specifications. However, these microscopes are expensive to own and operate.
As a substitute, we chose a standard Stereo Trinocular dissection microscope. A stereoscopic microscope uses two separate optical paths with two objectives and eyepieces to provide slightly different viewing angles to the left and right eyes. This arrangement produces a three-dimensional visualization of the object being examined.
The microscope that we chose was the Radical RSM9F microscope manufactured by Radical Scientific Equipments, purchased via an online marketplace. The microscope comes equipped with a 10Õ Eye piece and a magnification range from 7Õ to 45Õ, importantly the microscope has a suitable working distance of 200 mm. Additionally, a 0.5Õ objective lens adapter was provided, this allowed for the magnification to be adjusted to 3Õ to 22.5Õ, which is sufficient for most microsurgical exercises as well as a more graded control over the magnification. The instrument also came with a LED ring illuminator for illumination which was sufficient. The cost of the microscope was 40,250 INR (inclusive of shipping).
Setting up the microscope
The microscope was nearly assembled at the time of delivery and a few simple steps was all that was required to set up the microscope. The entire process took less than an hour. The relatively compact nature of the microscope allowed for it to be set up on a standard desk allowing for ample room to continue using the rest of the desk, a significant advantage over standard training microscopes which usually require a dedicated space as well as a formal mounting process [Figure 1]. Moreover, the microscope was small enough that it could be transported with ease, allowing for versatility in the training process [Figure 2].
Microsurgical instruments are another portion of the training simulator that requires significant investment. Most instruments that are available in the operating room are precision instruments that are made of titanium or titanium alloy and are quite expensive.
For training purposes, the instruments that we chose were a pair of stainless-steel jeweller's forceps, and a micro-scissor. Conventionally instruments for microsurgery vary from 8 to 13.5 cm, with longer instruments costing more. Our instruments were sourced from a local dealer in Chennai dealing with ophthalmological instruments (supplied mainly to ophthalmological residents). These instruments were not as finely machined or as precise as regular instruments; however, their tip width was approximately 3 mm and approximation (as visualized under magnification) was adequate for gripping and driving fine sutures such as 9-0 and 10-0 Nylon. The instruments were 11 cm in length. Unfortunately, microneedle holders are expensive and with limited resources at our disposal we substituted jeweller's forceps for the same. For further reduction in the cost of equipment some authors advocate substituting a micro-scissor, not micro needle holder with an Iris scissor, as both offer a similar cutting surface and point.
For vessel clamps, alligator clips used in electronics for wired connections with their edges filed down to prevent damage during occlusion were used. These clamps are readily available at any hobby or electrical store. It is of paramount importance to choose the smallest clamps that are available with a length of less than 3 mm and a tip of less than 2 mm.
9-0 and 10-0 Nylon sutures are both expensive and difficult to obtain. The cost of these sutures varies , but usually range around 500 INR for a single suture of 30 cm. This is troublesome as early in the training phase a significant amount of material is wasted. It is estimated that in experienced hands as well, approximately 0.5 cm of material is required for one suture. To overcome this hurdle, we chose to order our suture materials from an online Chinese vendor. These sutures listed as “make-up accessories” are in reality non-sterile nylon sutures. The added advantage being that they came with two needles for each suture of 30 cm allowing us to construct two 15 cm strands. The total cost was 25 USD for 20 packs (approximately 90 INR for each unit).
Gauze sutures [Figure 3]
A simple yet effective training exercise is to suture adjacent fibres of standard surgical gauze. Under magnification, sequential 9-0 or 10-0 nylon sutures are placed to approximate adjacent strands, emphasis is placed on placing the needle through the centre of the fibre with stabilization being offered by the non-dominant hand. This is a simple easily constructed model that is extremely economical.
Glove models [Figure 4]
Rubber latex allows for a naturally pliable and versatile material that simulates the vessel wall and allows for placement of sutures in a more “natural feeling” substance. Moreover, with the easy availability of surgical gloves, this again is an affordable model. The techniques to prepare this model range from simple exercises, such as suturing of two ends of a rent to more complicated models that better simulate vascular anastomosis.,
Chicken wing preparations
The chicken wing preparation is slightly more expensive and more difficult to construct but falls within the realm of economically feasible. The model maybe constructed in an intact chicken wing/leg or after some dissection to harvest the brachial or femoral vessels to construct a model for anastomosis.,, This allows for performing end-to-end and end-to-side anastomoses in natural vessels of calibre comparable to human cerebral vessels.
Other more complex models such as live rat models, human placental models, human cadaveric vessels, human cadaver models, and models using silicone microtubes were not used due to their cost and ethical considerations.
This training system allowed for residents at our institution to practice microsurgery on a day-to-day basis. The cost-effective nature of the entire construct and the limited effort in setting up the instruments as well as the compact nature of the setup allowed for easy access to the simulator. Simple exercises such as suturing on gloves and gauze required minimal preparation and allowed residents to commit time towards practicing microsurgery. Within a matter of weeks, residents had improved in terms of both speed and accuracy with an overall increase in efficiency under the microscope, both while practicing and in routine surgery. The ease of the system allowed for repeated practice sessions to be performed at the resident's convenience without affecting regular duties.
Training in a simulated environment is a prerequisite for any surgical discipline, more so in one as demanding as neurosurgery. The learning curve as well as the actual amount of time spent in surgery, especially in the role of the principal operator remain as hurdles to the successful application of skills in day-to-day practice.
While simulator labs have been a part of residency programs in more developed countries, the prohibitive expenditure involved, as well as the logistics in initiating and maintaining such a lab, remain significant hurdles in setting up such facilities in neurosurgical training centres in India. Residents in such institutions are then limited to train in the few centres that offer such courses, usually as a short-term endeavor ranging from as little as 5 days to a month. Alternatively, workshops offered in conferences shorten this training period to a few hours. This is problematic as the entire “practice session” is limited and that it involves the resident being away from the routine curriculum for this period. Moreover, intense training over such a short period without reapplying the acquired skills results in poor reproducibility. It is estimated that to successfully perform a procedure as complex as a STA-MCA bypass, a novice has to perform as many as 2,000 practice sutures. The progression of skills and surgical ability with practice has not only been documented, it has also been measured., In this scenario, an economical training model for microsurgery is required.
Our aim was to establish an easily reproducible and economic training system using products readily available in India. For appropriate magnification, a stereoscopic microscope was used. These microscopes commonly used in the field of electronics are useful as they provide adequate magnification (up to 45Õ in this case). Of particular importance was choosing a microscope with a comfortable working distance as most microscopes designed for this purpose, usually, have a working distance of 100 mm which is insufficient. The 200 mm working distance in this microscope allowed for operator comfort and a better simulation experience. Operators should be made aware of the fact that as the magnification increases the working distance of the microscope decreases. The microscope was provided with a 0.5Õ auxiliary lens which limited the magnification to a maximum of 22.5Õ but increased the working distance. Most training exercises do not usually require a magnification higher than this, however if so, desired the auxiliary lens may be removed to achieve such high magnification.
Instruments were another point of concern as most neurosurgical microinstruments are expensive. To circumvent this problem, we chose a “Bare bones” setup of two jeweller's forceps and a micro-scissors. Although ophthalmological instruments are less than 8 cm in length, upon request the manufacturer agreed to provide us with instruments that were 11 cm in length (albeit at a slightly higher cost). Though these instruments are not as precise as conventional instruments, they suit the purpose admirably. Prior to purchasing such an instrument, it is preferable to inspect it under a microscope to ensure that the “jaws” of the instrument approximate appropriately and are able to firmly grasp a hair follicle. Although a microneedle holder is desirable, suturing may also be performed with jeweller's forceps. The relative difficulty of the jeweller's forceps makes using a microneedle holder easier during regular surgery.
The training modules required limited preparation and as noted by numerous authors allow for adequate simulation of the operative environment. The simplicity and ease of access allows for residents to practice on a daily basis and continue this practice well beyond their residency, allowing for precision motor control and surgical finesse. While biological models and more complex simulators are superior, they do not offer the convenience or the cost-effectiveness of this model, which is imperative for sustained use and ready access.
While vessel anastomosis simulation, as offered by this model, does not encompass the whole of microneurosurgery and the number of surgeries performed have decreased following the outcome of the international cooperative study of external/internal arterial anastomosis published in 1985. However , not only are anastomotic procedures required in aneurysms with complex anatomy, tumors that require a bypass procedure for complete excision and selected cases of cerebral ischemia, the process of manipulating delicate suture material under magnification with microinstruments allows the resident to be familiarized with operating under the microscope, developing the hand–eye coordination and the precise motor control required for neurosurgery and the art of appropriate tissue handling.
In conclusion, the inexpensive nature of this training system and its inherent simplicity allows for a larger portion of neurosurgical residents in India, without access to sophisticated skills labs, to practice their skills in a controlled environment, without compromising on their ward duties. This would allow them to become proficient and confident during their residency and beyond.
We would like to thank Dr. M.D. Ravi for proof reading the article and for his valued suggestions.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]