Multiple transparent control areas

In our future we anticipate a more thoughtfully arranged environment with individual, high visibility control areas, not only for the interventionalist and the physician extenders who will work side by side with the interventionalist, but also for technical, anesthesiology and nursing staff within the procedure room. These highly visible individual and accessible control areas will be designed and positioned to negate or minimize the need for wearing lead protective garments. Much of the construction will likely be open feel with generous use of optically transparent shielding, rather than the separate and isolated control rooms that are the current standard.

Until we are able to perform most of our procedures without using ionizing radiation, we need to concentrate on protecting our radiation workers, both mechanically and spatially. We can shield ourselves and our colleagues in their own open sided control areas within the procedure room, instead of asking them to participate in procedures, as we currently do, in large open rooms, protected by clumsy, haphazardly placed movable shields. Although the immediacy of access may be slightly reduced with multiple individual open sided control areas, there are obvious advantages for nursing staff who need rapid access to medications and to nursing supplies such as are contained in current PYXIS systems. Individual open sided control areas avoid the inconvenience of multiple departures from the procedure room to procure necessary medications and medical supplies during the course of a procedure. Similarly, the current method of requiring the anesthesiologist to use suboptimal semi-portable monitoring systems, and providing radiation protection with clumsy, movable barriers that are difficult to position creates an ad hoc environment which does not conform to a best practice setting. A separate anesthesiology control area provides an ideal environment that provides the anesthesiologist with all the necessary monitoring equipment and supplies in a planned, ergonomic, fixed configuration. This approach can benefit from the expertise and planning of the most experienced anesthesiologists, based on their knowledge of the logistics of providing sedation and from the expertise of biomedical engineers and architects in designing such environments, rather than depending on the variable expertise of individual anesthesiologists to place movable radiation shields, carts and monitors in inconsistent locations which may not effectively serve their needs.

Integrative modular multimodality capability

Future rooms will more effectively accommodate dynamically changing imaging and therapeutic technologies through modular design. Diagnostic imaging and therapeutic technologies can be plugged and unplugged as needed and integrated into the unified image displays. At the extremes of sophistication, these NIS environments may include the investment of large sums in the marriage of minimally invasive surgery and large capital equipment imaging, and some of these rooms may be designed to include technologies such as robotic transcranial stereotaxy and flexible neuroendoscopy.

As procedures in traditional ORs have evolved to include less invasive approaches such as endoscopic procedures, a corollary trend of more aggressive percutaneous interventions in non-OR environments has led to a convergence of methods. When considering the range of procedures that could be performed in the NIS room of the future, two philosophical approaches exist. The first approach contemplates complex, highly invasive, long duration procedures that can be performed in this procedural environment, with a view to a wide range of novel procedures. The second approach involves designing the environment for maximal throughput of short duration procedures and contemplates a much narrower range of procedures that can be performed with high efficiency. The high throughput suites will predominate as we move towards progressively more sophisticated minimally invasive approaches. Potentially, these procedural environments could become more similar to surgical ORs in terms of infection control infrastructure, requiring scrub only access and including multiple air exchanges, especially if the design considerations will include open surgical cases. For environments that evolve to include open surgical cases, these traditional surgical infrastructure needs will be as important as the need for enhanced imaging and diagnosis. The more ambitious open surgery compatible neurosurgical operating rooms of the future will likely incorporate a variety of therapeutic and imaging tools, including, but not limited to, CT, MRI and positron emission tomography,4 will permit craniotomies for aneurysm or arteriovenous malformations or tumors and will be equipped to meet the necessary specifications for open surgery, such as specified rates for air exchanges.5

Space planning for proximities

NIS procedures are part of the continuum of care that includes not only the intraprocedural component of care but also preprocedure care, workflow, postprocedure care and proximity to other necessary services. Within the procedure room, medical support issues include sedation and anesthesiology, nursing and technical support, fluid and environmental support and the various processes and systems which enable the safest procedure with the best potential outcome. The success of NIS procedures hinges on appropriate patient selection, preparation and postprocedure care. With demands for increased efficiency, consistency and safety, we may choose to pay greater attention to the operations management and workflow advantages of placing our procedure rooms inside the main OR envelope or adjacent to ICUs, or to placing our procedure rooms in specialized multispecialty centers. The choice of location or service line showcasing will likely be determined in large part by the scope and type of the institution. It is conceivable that a stroke–neurology driven practice has a greater need for immediately available adjoining MRI or proximity to an emergency department than a surgical driven practice focusing mainly on aneurysm treatment that has a greater need for proximity to the neuro-ICU. Similarly, a practice focusing on pain management and spinal interventions may benefit from proximity to appropriate outpatient centers from which these patients are referred, rather than occupying valuable space adjoining the MRI suite or a neuro-ICU.

Apronless worker protection

Radiation shielding design will have to be completely reconsidered and new approaches developed.6 The current paradigm of physicians and staff wearing ergonomically cumbersome lead protective garments exposes their spines and musculoskeletal systems to chronic injury and leads to occupational hazards including time inefficiencies and early curtailment of careers due to spinal disabilities.7 This is economically disadvantageous as the need for larger numbers of these highly trained operators and technologists are required.

Radiation dosage to operators will be reduced with technique optimization, with adherence to guidelines from professional societies, and with more consistent quality maintenance programs. High visibility shielding will likely be supported by alternative suspension systems. Low dose fluoroscopy loops will be recorded, in place of many higher dose digital fluorography runs, as we move towards ever lower doses and greater avoidance of ionizing radiation. It is likely that non-ionizing imaging techniques such as ultrasound and optical coherence tomography or radiofrequency localization will be used to co-register images and to perform desired complementary imaging or guide catheter placement following initial road mapping. As an example, it may not be necessary to use continuous fluoroscopy if a three-dimensional angiogram is stored. Navigation of the vascular tree could be performed through co-registered endovascular ultrasound or radiofrequency tool localization if the necessary co-registration technologies are incorporated into the instrumentation tools. Patient radiation dose is already becoming a critical issue as more and more radiologic procedures with high exposures are performed.6 It is ironic that despite advances in multiple technologies in various areas of non-ionizing imaging, ionizing radiation is still the core of sophisticated intravascular interventional work. Germinal efforts with MR guidance for endovascular and percutaneous interventions may be expected to advance although our progress has been extremely slow in this area. Interventional MRI will prove useful for many procedures and patients where the physiologic or parenchymal effects of ablative or resection therapies need to be visualized in near real time.8

Integrative monitors

Although we seek access to progressively greater amounts of intraprocedural imaging and physiologic information, current procedure rooms are not particularly well suited to simultaneously viewing and comprehension of large amounts of data. In current state of the art rooms, for example, a neurointerventionalist may be presented with information that is displayed on eight large ceiling suspended monitors simultaneously: lateral and frontal reference angiograms, lateral and frontal live fluoroscopy, lateral and frontal road maps, a physiologic monitor and a three-dimensional reference image of the vasculature or lesion. This visual information is displayed across such a wide visual angle that full visualization is possible only by turning one's head. If we are to improve our comprehension of the visual information delivered in the suite, a way is needed to integrate this information into a smaller visual space that can be viewed interactively. Evolution in the understanding of psychological ergonomics has led to marked changes and advances in information visualization and processing for other environments which are data rich and critical to safety, such as jet fighter cockpits.9–11 These changes reduce the mental effort of understanding and using multiple visual information streams. This discipline of ergonomic multistream visualization necessitates an understanding of the needs of the operator and the utility of the multiple converging streams of information. The operator must be able to incorporate and understand the visual information in the context of the specific target and therapeutic intention during the entire course of a dynamic and complex procedure. At the same time, redundant or superfluous information must be minimized.

Our graphic user displays will include a greater number of imported multiple datastreams in the form of multimodal and physiologic information from both endovascular and computational sources. The proceduralist will use this information dynamically throughout the course of the procedure with the assistance of the physician extenders and technologists. The information will include such diverse scalar information as the individual territorial functional MRI and somatosensory information for a targeted arteriovenous malformation pedicle selected for potential embolization, the dynamic real time flow and pressure physiology (with dangerous changes highlighted) for an individual aneurysm during aneurysm treatment, the objective characteristic plaque contents within a targeted atherosclerotic lesion that might modify the proceduralist's selection of therapeutic modality or the dynamic changes in three-dimensional penumbra with specific reference to eloquent cortical areas during the course of a stroke revascularization.

Robotic intermediaries and simulation

For improved operator performance, it would be helpful to have consistent and robust room controls and interfaces with greater uniformity among manufacturers, so that the interventionalist is familiar and comfortable with equipment from all manufacturers. Some progress has already been made in this area. However, inconsistent interfaces and evolving input devices with varying and arbitrary layouts demand ongoing operator relearning which interferes with the development of optimized expertise.

As simulation technology is advanced and incorporated into the teaching process, one possible outcome may be increased utilization of virtual space interactions with operator interfaces or haptic feedback.12 13 If current procedural methods and feedback become inadequate, specifically twisting/pushing/pulling/telescoping tubular and wire-like elements manually, we may then anticipate changing the effector method with added movable mechanical or electromechanical elements at the tips of our instruments actuated by new and more effective operator interfaces that incorporate knobs, sliders, handles, buttons and sophisticated graphical user interfaces. Initial implementations of versions of robotic angiography exist where the operator is separated from the patient in order to protect the operator from the radiation environment. These systems use input devices and motions that do not replicate our current twisting, pushing and pulling.14

Simulation can be an effective first step in transforming conceptual procedures to procedural reality. It is easy to imagine testing of principles and input devices in simulation models prior to actually using them with patients. This is analogous to the aviation industry where the widespread use of flight simulators preceded the creation of fly by wire aircraft, in which there is no direct mechanical connection between the pilot and the engines and control surfaces. As pilots became more comfortable in the simulation environment, their insistence on their physical bellcrank and pushtube connection to the airplane control surfaces disappeared.15 Although there are current efforts underway to develop robotic methods for angiography, perhaps our improvements in simulators will help us more quickly evolve beyond our current tools to robotic intermediaries which add novel abilities, rather than simply providing remote control.16 17 Advanced NIS simulation techniques, with the integration of new software techniques, will ultimately result in the use of intelligent navigation. This may eventually permit pointing and clicking on a stylized image of an artery as physician operators supervise the semi-automated process and watch the catheter and wire automatically engage and enter the selected vessels and act as directed. The tools may well incorporate MEMS (Micro Electronic Mechanical Systems) technologies with micro fabrication and piggy backing of various ablative and in vitro diagnostic tools on a multi-capable catheter package. Additional benefits of this technology will be the development of simulations built on graphic user interfaces as a practical training tool and testing instrument.13 By developing simulations of complications and disaster scenarios, future physicians will learn how best to respond before actually encountering these critical situations in live patients. This is the same approach currently used to train individuals in disciplines as different as aviation and anesthesiologists.

Datastream and scrub technologists

There are evolving needs for two types of assistants with divergent skill sets. The first is the need for individuals with expertise and ability at importing and displaying information from multiple physiologic and anatomic data streams in a manner which optimizes procedural workflow, and the second is the need for individuals with expertise and ability at preparing procedural tools and supplies and assisting the interventionalist. The former individual fulfills the role of an imaging postprocessing technologist who manages and manipulates the stream of imaging and data, and the latter individual fulfills a role similar to that of the traditional intraoperative scrub nurse. Although it is possible that future data postprocessing needs may be met by improved interfaces and automated depiction systems, even our current needs for intraprocedural image processing indicate an increasing requirement for technologist presence and ability. Similarly, although preparation and assembly of interventional tools and products may become more streamlined and simplified over time, the use of physician extender scrub assistants for intraprocedural assistance may become commonplace in order to maximize efficiency, safety and throughput while permitting interventionalists to focus on their own specialized tasks.

Multiple datastream importation

NIS initially established itself as a discipline through a detailed understanding of neurovascular anatomy as the fundamental basis for understanding therapeutic neurovascular needs and physiologic states. A primary focus in the interventional laboratory of the future will be the integration of information from multiple imaging modalities in a seamless manner so that information gained from one anatomic or physiologic imaging technique enhances and is incorporated in an additive manner to information acquired by other techniques. As imaging has evolved, it has grown to encompass direct assessment of physiology. As an example, regional cerebral blood flow is now measurable with isotopic imaging, MRI, CT perfusion and ultrasound based assessment. As we seek to improve our physiologic understanding at the scale of brain regions and tissues, we have worked to address ever smaller volumes of tissue, extending our vision even to populations of cells. We may, as an example, be interested in objectively measuring and understanding the postprocedure increased blood flow through an angioplastied vessel. Much thought and work has been focused on understanding computational flow dynamics and the physiologic basis for neurovascular disease states. These directed investigations have included assessment of diseases such as high flow vascular malformations and intracranial aneurysms.18 It is possible to use computational approaches to demonstrate wall shear stress and shear stress gradients in three-dimensional aneurysm models. These approaches hold promise at helping us understand how aneurysms grow, which aneurysms are at risk for rupture, how we may decrease or increase risk of aneurysm rupture as we intervene on aneurysms and change the internal flow characteristics, and at what point in treatment we can confidently characterize an aneurysm as having been successfully protected. We will likely expect to apply real time physiologic analysis to our intraprocedural analysis and visualization of aneurysms and other disease states during the course of our interventions.

As an example of current limitations, there are currently multiple modalities that permit assessment and visualization of blood vessels and vascular structures. At present, each of these modalities is interpreted independently of the others. Fusion of these vascular imaging data sets would permit an optimized pre- or intraprocedural perspective. As we learn progressively more about vessel wall components, and move down the spatial scale from macro tissue scales towards the cellular scale, we may find it beneficial to have intraprocedural compositional information regarding the vessel wall and pressure and physiologic flow information. Understanding plaque and vessel wall composition and lesion morphology may determine which therapies are most likely to be successful.19 20 Specifically, intraplaque hemorrhage, vulnerable or free lipid pool components, distribution and density of calcification, ulcerations, fibroproliferative responses to prior interventions and other variables contributing to procedural success, failure or modification will likely become more fully and routinely characterized.21 Intravascular tools such as ultrasound, dual photon spectroscopy, near infrared spectroscopy and optical coherence tomography will likely gain further in utility21–26 and will complement molecular imaging for direct imaging of pathophysiologic processes such as plaque inflammation.26 Potentially, these instruments could be integrated into multimodal tools.

Current state of the art NIS suites include packages permitting integration of different imaging modalities (fluoroscopy, ultrasound, CT, MRI) in limited ways although these tools are not sufficiently facile or robust to be used for real time volumetric guidance. Currently, imaging workstations in our procedure suites utilize complicated, non-intuitive software packages which permit multimodality fusion.22 Unfortunately, the packages have not been designed with a realistic understanding of the interventionalists needs during NIS procedures, and these packages are not yet intended to permit dynamic intraprocedural utilization of fused datasets.

The ability to import and fuse large volumes of physiological information such as blood flow, electrical activity or metabolic and cellular imaging could dramatically enhance and expand intraprocedural therapeutic latitude and operator confidence while increasing safety. As a representative example, consider embolizing a feeding branch supplying a high flow vascular malformation of the brain in a suite permitting one to import functional MRI and cortical electrophysiologic information into a volume rendered brain image that is superimposed on angiographic images. The fused information may help determine whether intentional occlusion of a particular superselectively catheterized branch would result in a complication of injury to eloquent cortex.

Satisfying such disparate needs as hemodynamic monitoring, billing, hospital information and archiving will require a much greater and more rapid level of integration and development of IT to achieve necessary efficiencies. As we have also seen with the advent of smart phones, iPads and the cloud, evolution implies that novel IT will become progressively thinner with concentration on applications, as dependent hardware is progressively outsourced with very different capitalization and rental models from our current systems.

Demographic data will be entered automatically rather than manually, and just once; in addition, all images will be retrievable on hospital and network office computers and system PDAs for immediate review. By avoiding errors associated with manual data entry, billing and archiving will be simplified. Efficiency is improved as information resides in one primary integrated database instead of several disparate locations although backup systems for IT disasters will also need to be in place. Implementation of an electronic health record will make it possible to rapidly retrieve data and images from examinations performed at other hospitals and institutions. Patient satisfaction will increase as there will no longer be a need to answer the same informational and historical questions multiple times as the patient progresses from admitting, through the procedure, to recovery. Similarly, as with patients, practitioners will likely be automatically identified by systems analogous to radiofrequency identification tags as a natural extension of our swipable IDs or smartphones, and elements as disparate as the physicians exposure information and practice connectivity will be automated and integrated, probably permitting customizable practice preference, including procedure tools, setup and imaging displays that automatically adjust to individual operators as the workday progresses.

Quality and performance monitoring/measuring/exporting

Procedural rooms of the future will need to address the ergonomic and safety needs of NIS, in addition to the safety and efficacy demands of society. Societal expectations will be for pooled knowledge where maximal value is gained from each learning opportunity. Multiple communicating databases are likely to become universalized with de-identified and automated input of anatomic, physiologic, molecular and genetic information from the largest possible number of patients to respond to the needs of science, regulators and payers. Databases will also include practitioner information, potentially including procedural efficiency and motion graded scoring, and could be part of a seamless educational effort directing the practitioner to appropriate self-assessment modules as lifelong learning becomes second nature.

Perhaps because of the germinal nature of our specialty and the relatively small number of cases each of us is exposed to as a practitioner, we have not been successful as a specialty in aggregating our experiences and patients into universalized or large scale databases. We have not yet recognized the utility of learning from each patient in the broadest possible manner as a valuable opportunity for organized collective learning. Aggregation of information systems and the mandatory consolidation of information into national databases could provide a number of advantages, and may be centrally dictated by third party payers and the federal government. Quality assurance will likely demand benchmarking on a national scale, and potentially also require automated information input. This type of widespread information gathering may be perceived as a necessary ingredient in the development of comparative effectiveness pathways and outcomes analyses. There is historical precedent, as the National Surgical Quality Improvement Plan (NSQIP) and Database evolved out of the VA system, and has since become widely accepted.27 In the future, both government and private insurers will likely require all interventionalists to submit radiation use and procedural data for quality and outcomes analysis, and will connect this to reimbursement levels. Such efforts would be undertaken with the intent of ensuring better patient outcomes and appropriate case selection, and will likely include dynamic and real time public reporting as defining valid quality and appropriateness criteria becomes progressively more data driven.28

Utilization trajectory matched automated inventory systems

With an ever increasing greater range of inventory, and with increasing numbers of progressively more costly implantable devices in a variety of sizes and shapes, inventory management is a significant challenge. The laboratory manager and administration will be confronted with conflicting requirements as the pressures to limit cost increases collide with the need for competitive investments in large assortments of expensive tools. At a time of diminishing reimbursement, it has become progressively more difficult for institutions to sink significant capital sums into supplies with limited shelf life. Integrated inventory management, billing and scheduling systems are not only a fundamental operational requirement but also essential tools for financial viability in the efficient laboratory of the future. Flexible purchasing arrangements with industry, including contingency based purchasing, will be necessary to prevent the expiration of infrequently used disposables from becoming an unaffordable cost. Just in time inventory management and stocking to usage trends will be necessary to control inventory costs.

Interventions in previously inaccessible anatomic spaces

When we consider unmet needs in clinical practice there are new opportunities for neurointerventional surgeons to explore, including transvascular and intracisternal procedures. Transvascular procedures utilize arteries or veins as access conduits to extravascular spaces, similar to NOTES (natural orifice transluminal endovascular surgery) which uses novel extraluminal access pathways to perform minimally invasive endoscopic surgery. As examples of transluminal NIS, both the parenchyma and cisterns may be potentially accessed with transarterial or transvenous extraluminal therapies as direct parenchymal or CSF pathway access is sought from arterial or venous access.29 Intracisternal therapies may also be realized through direct puncture CSF pathway instrumentation from thecal sac or transcranial microportals, and may be more fully explored if and when neurointerventional surgeons decide to pursue the potential applications of flexible neuroendoscopy.30 With such methods, it is easy to imagine using transvascular neurologic approaches as platform technologies to perform deep electrode placement, functional neurosurgery, stem cell placement or small and large territory tissue bed ablation or resection.

Depending on the specific application, technologies such as MRI or functional MRI may be necessary to confirm or visualize the effect of therapies for movement disorder treatment, intraprocedural real time visualization of therapy or resection, and visualization of injectate dispersion and tissue implantation. Procedural spaces may also need to house cross sectional imaging methods for validation of treatment or effect, such as intraprocedural MRI or positron emission tomography. For these procedures it may be helpful, and possibly essential, to integrate multimodality imaging.