The advent of the endovascular surgery dates back to 1995 when the Guglielmi Detachable
coils were approved by the Food and Drug Administration (FDA).[1] This fascinating new approach to the neurovascular disease facilitated the treatment
of the same vascular lesion via an endoluminal technique within the blood vessel.
The realization of less morbidity and mortality by this approach due to its minimal
invasive nature has made this technique a favorable one in treating most of the neurovascular
diseases. Simultaneous trials began to validate the efficacy and safety of this new
modality in aneurysm treatment, and in a short span of 10 years, the new modality
shined enough to start eclipsing the gold standard procedure of the time, namely “clipping.”
ISAT (International Subarachnoid Aneurysm Trial) and BRAT (Barrow Ruptured Aneurysm
Trial) trials started the discussion of coiling versus clipping, and the evidence-based
studies started leaning in favor of coiling. The response of the surgical community
was natural, and reactionary opposition as the coiling was not done by most neurosurgeons.[2]
[3]
[4]
[5] The situation seemed ripe for the pharmaceutical companies that started investing
huge amounts of money to develop the hardware needed, and this led to the rapid advancement
in the endovascular techniques. Technological advances included a variety of the devices
incorporated in the armamentarium, including various types of coils, balloon catheters,
access catheters, embolization materials, flow diverters, stents, and so on. On the
other hand, surgical techniques of aneurysm coiling remained static and nothing significant
changed over the last couple of decades. The spectrum of the vascular lesions treated
by the endovascular intervention progressively increased from coiling of aneurysms
to management of fistula, arteriovenous malformations, vascular tumors, and stroke.
However, the application of this technique to the aneurysm revolutionized the approach
by which an aneurysm is dealt in an altogether different way. Analyzing the inevitable
takeover by endovascular modalities, many neurosurgeons started training in this new
specialty with the concept that they will be better than others in managing aneurysm.
This assumption was based on the fact that all the patients of subarachnoid hemorrhage
(SAH) have been managed by neurosurgeons for decades, be it simple clipping or any
complication of the SAH—like hydrocephalus, hematoma evacuation, or decompressive
craniotomy—as the need may be. Even in many salvage procedures following complications
in coiling, a neurosurgeon has to step in. Therefore, endovascular technique started
becoming a popular choice among neurosurgical residents. Incorporation of the basic
endovascular skills in the curriculum of the trainees is the need of the hour. The
American Board of the Neurosurgical Survey has already made this mandatory. Residents
should be well acquainted with the knowledge of the neurovascular anatomy and be familiar
with the basic devices and angiographic equipment. They should be able to perform
four-vessel angiogram and be research oriented. These basic skills will help the trainees
master the technique quickly in their future fellowship. Conversely, the residents
who will not acquire basic endovascular skills have to overcome the steep learning
curve and may not be able to perform the endovascular procedures by the completion
of their fellowship program.[6]
The need of the hour is the making of the hybrid neurosurgeon who is well versed in
both microvascular surgery and endovascular techniques. The important point to mention
is that the two techniques should not be viewed as diametrically opposite treatment
modalities but collaborative and supplemented taking into full consideration the natural
history of the disease and the risk-benefit ratio of the procedure. To achieve competence,
trainees will require an exposure to a variety of the vascular lesions during training
along with adjuncts like training in cadaveric dissection, microsurgical and endovascular
skill laboratories, and animal procedure simulators. This issue needs to be addressed
in the new training program. Most neurosurgeons perceive and consider microsurgical
procedure to have a steeper learning curve than endovascular techniques; thus, the
hybrid neurosurgeon shows a greater tendency toward endovascular technique due to
the less time required to master. Equal time and training skills should be provided
to trainees in both techniques to eliminate this bias.
Chalouhi et al studied the preparedness of U.S. neurosurgery graduate trainees for
neuroendovascular fellowship. This study's results suggest potential gaps in the training
of neurosurgery residents regarding endovascular neurosurgery. In an era of minimally
invasive therapies, changes in residency curricula may be needed to keep pace with
the ever-changing field of neurosurgery.[7] In our institute, once our department decided to start the program, I and one more
faculty member went for training in the endovascular procedures. Since then we could
start coiling of the aneurysms and our residents are now getting the training simultaneously
in both conventional neurosurgery and endovascular surgery.
Most studies and the research in Europe and North America regarding the incorporation
of dual-training program in the curriculum of the neurosurgical residents have proven
to be beneficial. The landscape of the neurovascular disease is ever changing. Therefore,
there has to be a rapid paradigm shift in the training and the resident education.
Although the hybrid training is a norm in North America, in our country, the integration
of such endovascular surgery is still in infancy. The complexity of the microsurgical
technique with time restriction has made it intensely difficult to concentrate on
both fields. It is an uphill task to master both techniques during training so what
seems feasible is learning the basic skill of both during the training program. This
can be accomplished by making it mandatory for neurosurgical trainees to learn four-vessel
angiogram, be well versed in the neurosurgical anatomy, and acquire learning skill
in the endovascular and microsurgical laboratory. However, this requires a good financial
support and sponsorship, which can be a major obstacle in a developing country such
as India. These training programs should be scrutinized and monitored and critical
evaluation of the outcome should be done.[6]
[7]
Conclusion
In developing countries, in both the fields of preparing the curriculum and monitoring
the training program for hybrid neurosurgeons, various neurosurgical societies in
the country can take a lead role. This is important, as the clipping will continue
to be used in most patients, as the affordability is a major concern in this part
of the world. Nevertheless, the growing middle class will be the patient population
who will be moving toward endovascular interventions as the demand for minimally invasive
procedures is growing in all the surgical specialties and neurosurgery is no exception.
The ultimate goal should be to make a proficient hybrid neurosurgeon, one who would
be well versed in all the treatment modalities and their consequences. This can be
achieved by extensive endovascular and microsurgical exposure during training. Ultimately,
the progression to mastery of the expertise will depend on the dedication of the concerned
surgeon.
