The field of neurovascular surgery was born with Walter Dandy’s description of the treatment of an intracranial aneurysm with surgical clip ligation.¹ Since its genesis, numerous advances have propelled the evolution the field of neurovascular surgery. For example, the assimilation of the operating microscope has allowed improved visualization and understanding of the anatomic substrate. A further result of magnifying and illuminating the microvascular surgical field are the advances in the ergonomics and design effectiveness of instruments. The recent focus on outcomes has led to the codification of a set of psychomotor skills that are essential for the successful operative treatment of neurovascular disorders. In the current sports parlance, the microscope has caused us to focus on our “short game.” Indeed, common terms associated with this skill set include among others “touch” and “soft hands.” The long tee shot may be analogous to the postoperative angiogram showing obliteration of the aneurysm, whereas low scores (good neurologic outcome) result from that delicate touch around perforators and short temporary clip times.

Although some of the basic underlying mechanisms of neurovascular physiology are yet to be completely elucidated at the cellular or molecular levels, concurrent advances in science and medicine have led to modern concepts of the field, including brain ischemia, stroke, cerebral vasospasm, and cellular and molecular mechanisms of neuronal injury and death. However, neurovascular surgery, and indeed neurosurgery itself, continues to change at an escalating pace driven by technological, social, and economic progress.^2–5 Indeed, these changes have called into question the very definition of the neurovascular surgeon. It follows that the training paradigm for the modern and future neurovascular surgeon must be similarly reexamined and restructured to reflect these changes to remain effective. In this chapter, we review the elements that characterize the effective training and development of the traditional microvascular neurosurgeon. From this starting point, the major forces that are driving the evolution of neurovascular surgery are examined, including the changing paradigms and scope of practice of the field, the forces affecting neurosurgical training within the context of residency education generally, and the evolving issues that relate to credentialing and fellowship accreditation. Consideration of these issues raises many important questions, the answers of which will no doubt impact the training of the modern neurovascular surgical specialist into the future.

The development of the microvascular neurosurgeon ideally begins with the identification of suitable individuals to undergo the training process.⁶ We have yet to specifically define the aptitudes necessary for cerebrovascular surgery; thus, we must rely on the process that generates the entire pool of neurosurgical residents. For the most part, cerebrovascular practitioners are selfselected, as are other neurosurgical subspecialists. The criterion for that selection is solely based on interest, which frequently is dependent on association with a role model. Assuming the self-selection process works, the burden is then on the training program to develop the competencies that produce a satisfactory level of performance. The success of any training program can be considered to be measured by achieving competency in the following areas: (1) patient care, (2) medical knowledge, (3) practice-based learning and improvement, (4) interpersonal and communication skills, (5) professionalism, and (6) systems-based practice.

The Ideal Characteristics of a Microvascular Neurosurgeon

The ideal characteristics of a microvascular neurosurgeon are similar to those demanded of other highly technical disciplines that involve a high level of risk.⁶ A consensus conference on surgical education has developed a set of personality traits that correlate with an agreed-upon ideal. Emotional control is a key characteristic of a microvascular surgeon. The ability to remain even-tempered and maintain flexibility during stressful situations exemplifies that control. A strong sense of self-efficacy is integral; this promotes the decisiveness needed to enable the kind of prioritization necessary for complex tasks. Aggression tempered by compassion allows for the ideal balance between “pushing the envelope” of skill maximization while remaining cognizant of some safety limits. Of course, individual personality traits will ultimately serve as the basis for the development of important interpersonal and communication skills for effective practice.

Given the level of risk often associated with neurovascular operations, a high degree of integrity is absolutely required; honest self-assessment is required throughout the development of the neurovascular surgeon to ultimately ensure the delivery of compassionate patient care. Improvement in patient care occurs through practice-based learning that involves investigation and an honest evaluation of an individual’s own patient care and appraisal and assimilation of scientific evidence. Integrity is also critical for the trainee to develop an understanding of the practice and implications of cerebrovascular surgery in the larger context of the health care system in general.

Along with ideal personality traits, aptitude for cerebrovascular surgery includes superior manual dexterity with multilimb coordination.⁶ There are few areas of surgery where maneuvers spanning less than a millimeter can result in such devastating disability. However, vascular procedures by nature can be long and complex, so efficiency and coordination of subtasks is equally important to good outcomes. The technology to select for these skills is lacking; hence, they must be inferred from other information. To the extent that at the medical student level, some operating room (OR) experience has been witnessed or a research experience has been gained that included some psychomotor surgical skills, evidence of aptitude may be forthcoming. In its absence, inference of bimanual skills can conceivably be gained by the candidates’ performance in athletics or musical instrumentation, endeavors where individual performers with special potential are similarly identified for training.⁷ Indeed, during a recent lecture by the senior author to a group that can be considered “experts” in microvascular neurosurgery, the majority had engaged in either or both music performance or athletics at a high level. Elite athletes and musicians, by virtue of the preparation needed for their performances develop or inherently manifest both a resistance to boredom and physical and mental stamina. Given the nature of surgical training, which still amounts to apprenticeship, it is easy to see how these two characteristics would be highly valued in a cerebrovascular trainee. Finally, the intellectual endowment of the trainee that is critical to the conceptualization, ordering, and execution of complex cerebrovascular treatment plans must be established through academic performance in credible institutions, awards, board scores, leadership roles, letters of recommendation, research, and personal motivation as reflected in personal statements.

Into the middle level of training, skills for independent management decisions are acquired, and the trainee begins to focus on outcome generation and to check his or her own actions appropriately. Observation of local practices is considered within the context of the current literature and information from organized conferences, leading to the initial development of critical thinking. With an increasing supervisory role, the mid-level trainee develops individual personality traits for effective leadership. In addition, increased clinical responsibilities require an increasing sense of urgency and prioritization skills for multiple, concurrent problems. At this point, the operative skill set is also expanded to include the use of frameless stereotactic neuronavigational systems. The mid-level trainee begins to assist in all cases, allowing for first-hand observation of the basic surgical techniques required for cerebrovascular surgery such as the Sylvian fissure split, carotid endarterectomy, aneurysm dissection and clipping, and arteriovenous malformation (AVM) dissection.

So far, the discussion has been limited to the period of initial development of the neurovascular surgeon. From this point, a progression occurs sequentially through increasing levels of expertise.⁶ The focus of the residency- training program is to bring the novice to the level of competence. Within the context of surgical skills, competence is acquiring the ability to perform procedures safely within a reasonable time. Society demands this level of expertise. As further training and practice is acquired, proficiency is achieved, where performance is expert in terms of task quality, efficiency, and outcome. In our current educational system, enrollment in a fellowship program is a key factor in accelerating the process. Aptitude, environment, and opportunity may coalesce in the development of the expert, who by virtue of his or her level of knowledge and skill is recognized as an authority. The ultimate level of master is reserved for those who produce masterpieces

The learning of neurovascular surgery can be understood from the perspective of the cognitive psychologist.⁶ Indeed, in FITT’s (Frequency, Intensity, Type, and Time) Stages of Cognitive Skill, the initial conceptualization stage is marked by the acquisition of skills and understanding of tasks (Fig. 27-1). This is the role of the residency and fellowship. Next, control processes are developed and strategies refined in the associative stage. Many refer to this stage as “experience gaining.” The implication is that this stage, to the extent that it is lengthy, results in increasing expertise. Clearly, that is wrong or the oldest surgeons would invariably have the best results. Finally, the proficiency stage is reached when automatic processing is achieved.

Automatic processing of a psychomotor skill occurs when the physical procedure is performed efficiently, ostensibly without the mental component. Shifting a standard transmission in an automobile is an example. Automatic processing of highly evolved skills that then produce repeatedly the desired result is what has been termed in sports “being in the zone.”^8,9 The expert or master cerebrovascular surgeon should at least occasionally experience that level.

FIGURE 27-1 The figure depicts FITT’s (Frequency, Intensity, Type, and Time) stages of cognitive skill.