Keywords

FormalPara Case Presentation

A 70-year-old gentleman with a history of coronary artery disease status post coronary artery bypass grafts ×3 presented as a transfer to our institution for a ruptured infrarenal abdominal aortic aneurysm with hypotension and back pain. The patient arrived intubated and was brought emergently to the hybrid operating room for endovascular repair. Both the anesthesia and operative team were present in the operating room to receive the patient on transfer.

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Introduction

The use of minimally invasive interventions to treat vascular disease has increased over the last few decades [1] due to decreased length of stay and post-operative morbidity with comparable results to open surgical procedures [2]. The angiography suite now serves as the primary location for vascular surgeons and other interventionalists to provide appropriate and expedited care as a part of their clinical practice. Though endovascular procedures have shown benefits for patients, interventionalists must recognize and address potential hazards associated with angiography and take the necessary precautions to reduce radiation exposure and workplace-associated injuries. This chapter serves to describe the process of setting up an efficient and safe angiography suite, as well as coordinating care to maximize utility of the suite in a hospital system.

Layout

There are a variety of factors to consider when planning for the installation of an angiography suite or hybrid operating room (OR) including, but not limited to, location, room set-up, adjunctive equipment, supplies, and imaging system [3, 4].

Location

Ideally, the angiography suite or hybrid room should be placed either near other interventional suites or the ORs in order to facility transportation of equipment, tools, and personnel. If the interventional suites are in a separate location from the ORs, it is preferred that a hybrid room be located next to the other ORs to allow for the immediate availability of surgical instruments and equipment, as well as anesthesia and operating room staff [5]. It is noted that this may not be possible due to structural or engineering limitations of the facility.

Room Set-Up

Booms

One or more moveable booms should be installed in order to maximize working space, organize equipment, and improve efficiency. The moveable aspect of the booms allows for flexibility of the angiography suite in order to accommodate various types interventions. Furthermore, the availability of electrical outlets, connectors, and gas/air outlets also facilitate the workflow. A separate boom may be necessary for the anesthesia team in order to further improve efficiency and organization.

Lighting

It is important to have both appropriate surgical lighting as well as ambient lighting during vascular interventional procedures. The lights will typically be ceiling mounted to improve adjustability and provide adequate lighting during open surgical approaches [6]. However, care must be taken in order to avoid frequent collisions with the display monitors and the imaging system. The ambient room lighting must provide the ability to dim as this is often helpful during fluoroscopy for improved visualization.

Monitors

Adequate imaging visualization is crucial in the setting of endovascular procedures. As such, high-quality monitors are essential for appropriate visualization by the operator and the assistant personnel. Ceiling mounted monitors provide the ability for greater range of motion in order to adjust and improve operator ergonomics. Multiple monitors are preferred to visualize the intervention as well as vitals and anesthesia metrics during the procedure.

Operating Table

There are a variety of factors to consider with operating tables. First, radiolucency of the table is necessary during fluoroscopic procedures with carbon fiber being the preferred material due to its lightweight and radiolucent properties. Floating tabletops will provide the ability for fast and precise movements during interventional procedures [7]. The addition of lead skirts surrounding the table will also help to reduce radiation scatter to the operator and assistants. Additional positioning aids, such as cushioned padding and radiolucent arm boards, are also necessary for specific vascular interventions such as dialysis access interventions or upper extremity fluoroscopy. Finally, the addition of side rails will allow for the mounting of surgical retractors that are sometimes necessary for more extensive open surgical interventions.

Storage

Adequate storage capacity with high-level organization is imperative in the angiography suite in order to ensure quick access to the necessary equipment and tools for a variety of interventions. Built-in storage cabinets will not only reduce workspace clutter, but also improve organizational design. Commonly used sheaths, catheters, wires, balloons, stents, closure devices and surgical equipment should be stored within these cabinets for ease of access during both fluoroscopic and hybrid procedures.

Control Room

The presence of a control room separate from the sterile operating field is ideal for additional visualization of images, operative case planning, supervision, and observation for trainees.

Adjunctive Equipment

Ultrasound

The use of ultrasound guidance for venous and arterial percutaneous access has been shown to reduce the incidence of complications at the entry site [8, 9]. Furthermore, duplex ultrasound is required for performance of certain interventions, such a venous ablation procedure [10].

Intravascular Ultrasound

The use of intravascular ultrasound serves as a important supplement in the setting of venous as well as aortic dissection interventions due to its ability to provide intraluminal visualization both pre and post-stent placement [4]. It is also a necessary adjunct to performing interventions for iliac venous occlusive disease [11]. Others have also suggested benefit for some peripheral interventions to more accurately identify stenoses and to assist with sizing for angioplasty or stent deployment [12, 13].

Power Injector

Utilization of a power injector allows for the operator to be positioned further from the radiation source and thereby reducing the exposure to the operative staff without sacrificing image quality or intervention time [14]. In the case of aortic imaging, the increased injection rate may also offer improved timing and visualization of critical structures while at the same time minimizing contrast load. The power injector can be mounted onto the operating table for added efficiency.

Carbon Dioxide Injector

With the prevalence of chronic kidney disease and contrast allergies within the population requiring vascular interventions, carbon dioxide (CO2) has established a role as a substitute for standard iodonated contrast. Therefore, the use of a CO2 injector proves to be a necessary adjunct in modern day vascular interventions [15].

Suction Thrombectomy Systems

Endovascular intervention for acute arterial and venous thrombus are increasingly utilized in modern vascular interventions [16, 17]. With the development of catheter-directed suction thrombectomy, there has been increased utilization of this technology in the setting of acute limb ischemia, iliofemoral deep venous thrombosis, pulmonary embolism, and even mesenteric or visceral vessel thrombosis. The purchase of the suction thrombectomy system may potentially reduce the long-term costs of repeat catheter-directed interventions in exchange for an increased overhead cost of the initial purchase.

Commonly Used Supplies

In comparison to open surgical procedures, which utilize a standard set of reusable instruments and clamps for most cases, there is a significant added cost to having adequate disposable supplies for endovascular interventions. Physicians within the system and practice should therefore collaborate in order to standardize and simplify the necessary equipment and supplies. This can allow for in-bulk purchasing or contract agreements with supply companies to reduce the cost of supplies. Table 4.1 summarizes the broad categories of necessary equipment and supplies needed for a range of endovascular procedures [4].

Table 4.1 Commonly used equipment for various procedure types
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Imaging System

There are a wide variety of imaging systems available for use. Rather than focusing on the advantages and disadvantages of specific systems, this section will highlight various features that may be important for optimal imaging during endovascular interventions.

Mounting

A ceiling-mounted systems provides the benefit of reducing the amount of space occupied, however, this comes in exchange for potential interference with lights, booms, and monitors as well as the potential decreased sterility due to dust or particle trapping within the system itself. Floor-mounted systems may occupy additional floor space, but can often times be moved during non-fluoroscopic portions of the operation and are suggested to be more hygienic by some authors [3].

Image Detection

Most, if not all, fixed imaging systems now come equipped with flat panel detectors, which produce higher image quality and resolution are compared to image intensifiers, with some systems providing resolution at four times the conventional systems (over 2000 pixels resolution) [18]. Flat panel detectors also produce a larger field of view, which may prove to be essential in the setting of advanced endovascular interventions, such as fenestrated endovascular aortic aneurysm repair. The dimensions of the flat panel detector among commonly used systems are 30 × 38 cm for maximum field of view with certain broad detectors reaching up to 41 × 41 cm [18,19,20]. Additionally, these imaging systems may be equipped with 3D fusion imaging and reconstruction (i.e., EVAR Assist 2® from GE, SmartCT Angio® from Philips, and EVAR-3D Guidance® from Siemens) [21,22,23] to provide the ability to improve real-time intervention planning, to obtain real-time 3D image acquisition, as well as to decrease radiation exposure, contrast volume, and operative time by outlining vessels and optimizing angulation for precise device deployment.

The Benefits of a Hybrid Operating Room

The advancement in endovascular technologies has helped change the treatment paradigm of vascular therapy toward novel approaches that require both open surgical and endovascular interventions to address complex vascular disease. This approach has led to the development of a new working environment [24]. An updated, conventional angiography suite can aide in delivery of modern vascular care. Furthermore, a number of studies have demonstrated that a hybrid room with an endovascular suite integrated within a traditional OR offers significant benefits over both a conventional angiography suite and the use of a portable C-arm imaging system [25,26,27]. The benefits of a hybrid OR and limitations of a portable C-arm in a traditional operating room are listed below in Tables 4.2 and 4.3. A hybrid OR with an integrated imaging system provides the ability to seamlessly perform open surgical procedures and endovascular procedures during the same intervention. Often, complex endovascular interventions are assisted by an open surgical intervention, such as femoral endarterectomy, or vessel exposure, such as a brachial artery cutdown, to allow for endovascular interventions that would otherwise be difficult via a standard percutaneous approach. Furthermore, the ability to convert to an open surgical intervention in setting of unanticipated access or other complications during endovascular intervention provides an efficient manner to address these potential issues. The well-controlled conditions within the OR also serve to improve sterility and potentially reduce the risk of infection of implantable devices [28]. A mounted system provides the benefit of improved ergonomics and decreased radiation exposure to both the patient and the operator due to the improved imaging capabilities and safety measures when compared to the portable system used as an adjunct in the OR.

Table 4.2 The benefits of a hybrid operating room
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Table 4.3 Limitations of OR adaptations via portable C-arm system
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Examples of Hybrid Room Set-Up

Below we provide an example of a set up during an endovascular aortic repair of a ruptured aneurysm in the hybrid OR at our institution (Figs. 4.1 and 4.2). The layout of the hybrid room has been set up with the floor-mounted imaging system at the head of the table adjacent to the anesthesia staff in order to maximize operative space and field of view. Multiple ultrasound machines are available for both the anesthesia staff as well as the interventionalists to establish intravascular access for resuscitation, intraoperative monitoring, and procedural access. A Foley kit and bovie pads are also available for pre-procedural placement. The angiography table is placed in a neutral position with the monitor at, or below the eye level of the interventionalist.

Fig. 4.1
A photo of the hybrid operating room consists of the surgical table, radiology devices, angiography equipment, anesthesia delivery systems, and monitoring and recording systems.

Hybrid operating room design and set-up prior to endovascular abdominal aneurysm repair (EVAR)

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Fig. 4.2
3 photos of vascular intervention supplies and surgical instruments for E V A R include guidewires, catheters, sheaths, delivery systems, stent-grafts, angiography equipment, balloon catheters, and closure devices.

Vascular intervention supplies and surgical instruments for EVAR

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A micro-puncture vascular access kit has been opened and prepped in anticipation of percutaneous access to the common femoral arteries. In addition to basic wires (hydrophobic and hydrophilic), both selective and flush catheters have been opened and prepped in order to obtain an aortogram. Sheaths of various sizes (5–8 Fr) are available with additional larger bore sheaths and stiff wires on standby in case an aortic occlusion balloon is necessary for proximal control. The remainder of the stent grafts, closure devices and adjunctive supplies remain unopened, but within the room for quick and easy access. Furthermore, a tray of vascular surgical instruments along with bovie and suction equipment have been laid out in anticipation of potential open surgical exposure of access vessels in the setting of poor anatomy for percutaneous access or closure.

As highlighted by the clinical scenario, it is imperative to have a trained team with experience in both endovascular and open interventions assisting in a hybrid procedure, including circulating nurses, scrub techs, scrub nurses, and interventional assistants, such as physician assistants, residents, fellows, or surgical assistants in order to expedite the operative intervention and optimize patient outcomes.

Coordination with Other Specialties

Given the high overhead costs of constructing an angiography suite or hybrid operating room and the potential loss of revenue associated with only part-time use, it may be essential to coordinate with other interventional services (i.e., interventional radiology, cardiology, and cardiac surgery) in order to maximize the utility of the room with a variety of other interventional procedures such as cardiac catheterization and transcatheter aortic valve replacement. Therefore, an appropriate professional relationships should be established between various specialties in order to establish a comprehensive and interdisciplinary environment for cardiovascular intervention and patient care.

Ergonomics

While significant advances have been made in terms of radiation safety in the domain of fluoroscopic interventions, much less has been done to improve ergonomics. Interventionalists are at a high risk of orthopedic injuries often due to poor body mechanics and posture secondary to the burden of protective equipment and the poor ergonomic design of interventional suites [29,30,31,32]. Prior data from interventional radiologist and cardiologists have shown a high incidence of spinal complaints (cervical, thoracic, and lumbar) as well as axial skeleton complaints with an association to decreased longevity of their interventional careers [33]. This can contribute to work absences, poor overall health, and even affect procedural outcomes.

Effect of Ergonomic Challenges

A recently published study of interventional cardiologist demonstrated that approximately 9–33% of all participants reported missing work days due to their musculoskeletal complaints [34]. The increased need for leave of absences interrupts the workflow and may also lead to early retirement thus decreasing the long-term workforce. This trend is similarly reflected among vascular surgeons, with the majority of those surveyed by the Society of Vascular Surgery reporting pain after a day of open or endovascular procedures and a significant portion seeking medical care or even surgical intervention [35]. Furthermore, there is growing evidence suggesting that female surgeons and interventionalists are at an increased risk of musculoskeletal injuries compared to their male counterparts, particularly in the upper extremities [36, 37]. Finally, the pain associated with musculoskeletal injuries has been associated with self-reported burnout amongst vascular surgeons in a study by Davila et al. [38], which can have long-term detrimental physical and psychological effects on providers. Norasi et al. demonstrated both the neck and the trunk were at high risk of developing musculoskeletal disorders due to awkward posturing during surgical procedures. There was a more prominent risk in open operative procedures, especially when using visual aids such as loupes [39].

Radiation Shielding

The term “interventional disc disease” has been developed over the years to emphasize the trend of orthopedic work-related complaints. These complaints were more prominent amongst those using fluoroscopy as compared to other operative surgical specialties not using fluoroscopy suggesting a correlation with chronic lead apron use [33]. Appropriate fit and weight distribution of lead garments are essential to reduce the likelihood of musculoskeletal injury and fatigue. The introduction of two-piece garments as well as wrap-around lead has reduced axial strain and improved weight distribution. Additionally, the transition to composite or lead-free alternative protective garments further reduces overall weight, however, there have been some reported differences in terms of the amount of shielding provided compared to their lead equivalents [40, 41]. The development of a fully suspended radiation protection system equipped with radiation shielding from head to calf that eliminates the weight bearing component on the operator while maintaining mobility and maneuverability holds some promise for the future [42].

Room Design

Adjustments within the operating and procedure rooms must be tailored to maximize proceduralist ergonomics. Display monitors during fluoroscopic procedures as well as other imaging adjuncts should be placed in front of the interventionalist and in line with their shoulders allowing for neutral neck position with a slight downward (15°) angle thus reducing cervical spine strain [34]. Table height should also be adjusted in order to minimize prolonged muscle activation. Studies have shown that table and hand positioning at 70–80% of elbow height appears to reduce back discomfort [43]. Furthermore, additional adjuncts such as cushioned floor mats and the use of shoe insoles may also have a preventative effect on axial skeletal strain. Figure 4.3 demonstrates the example of ergonomics within the angiography suite as highlighted by Knuttinen et al. [34] Table height is adjusted according to the operator at near elbow height, duplex ultrasound and display monitors are positioned in the line of vision of the operator at a slight downward angle to avoid excessive neck strain during the intervention. Finally, while mobile lead shielding is essential in reducing radiation dose, it is important to account for postural changes involved in the use of the shielding in order to reduce the incidence of ergonomically unfavorable positions. Ergonomic strategies are summarized in Table 4.4 [34].

Fig. 4.3
2 photos of the operating setup in the lateral and frontal views. The surgeons operate on the right brachial artery in the dissected abdomen of the patient on the surgical table.

Proper ergonomic positioning during lower extremity angiography via right brachial approach, (a) side view of intra-procedural positioning with monitor in line of vision, table at elbow height and slight downward tilt of neck, (b) frontal view of intra-procedural posturing

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Table 4.4 Ergonomic strategies to reduce the risk of musculoskeletal injuries
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Case Presentation

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Once the patient was appropriately positioned with adequate access, his abdomen and groins were prepped in the standard sterile fashion. Bilateral femoral artery access was obtained simultaneously via micro-puncture access kits under duplex ultrasound guidance. After appropriate sheath placement, all operators moved to the right side of the patient and the monitor and table were adjusted for optimal visualization. The room lights were dimmed appropriately to improve visualization of the display without impeding the scrubs techs’ abilities to prepare the instruments and devices on the back table. The monitors were positioned at just below operator eye level to reduce cervical strain during the intervention. Each operator and assistant also wore fitted two-piece lead aprons to reduce thoracic and lumbar spine strain during the procedure. The floating tabletop in the hybrid suit allowed for rapid patient movement during the intervention to adequately visualize both proximally into the aorta and distally into the iliac arteries. A 32 cm Medtronic Endurant® endograft was deployed with iliac extensions bilaterally (Fig. 4.4). The storage capacity of the hybrid suite allowed for rapid access to the necessary catheters and balloons to ensure appropriate cannulation of endograft and deployment of the iliac limbs. The use of a power injector along with the improved magnification and resolution of the integrated imaging system allowed for precise deployment of the endograft while minimizing contrast use and radiation. Both femoral accesses were closed with the pre-deployed ProGlides® without complications, though surgical instruments were opened and prepared in the hybrid suite for expedited femoral cutdowns and arterial repair in case of closure device failure. The patient was brought ICU for resuscitation and recovery in stable condition. He was extubated on post-operative day one and only had a transient acute kidney injury that resolved during his hospital course with appropriate urine output throughout. He was discharged home on post-operative day 6.

Fig. 4.4
An angiographic image of the abdominal aorta exhibits the swelling and rupture of the aortic wall in a dark shade.

Completion angiography after successful EVAR of ruptured abdominal aortic aneurysm

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