Hybrid Angiography-CT Room: A Unique Environment for Expanding the Frontiers of IR

Dr. Carlos Abath

INTRODUCTION

The evolution of Interventional Radiology (IR) began over 60 years ago with a simple question. Could be used the same diagnostic imaging tools that have revolutionized the practice of medicine to guide the real-time treatment of disease? It became obvious that imaging could be used better to enable certain patients to undergo targeted procedures, eliminating the need for major surgery, and others could undergo procedures for previously unsolvable problems. Since its advent, IR has expanded to encompass treatment of various diseases across multiple body systems.
Dr. Carlos Abath, Head of Interventional Radiology at Real Hospital Português
Interventional procedures are minimally invasive, based on image-guided techniques, such as US, CT, MRI, or DSA, and can be classified as vascular and non-vascular procedures. Vascular interventions are performed by an endovascular route, utilizing catheters, wires, and special devices to reach the target and achieve the treatment objective. The techniques used include: angioplasty and stenting of a stenotic or occluded vessel, implant of vena cava filter to prevent pulmonary embolism, delivery of embolic agents for tumor shrinkage, to stop bleeding and to occlude aneurysms and vascular malformations, or endoprosthesis introduction for aortic aneurysm repair. All these interventions are done with DSA, in an angiographic sterile operating room. Non-vascular procedures include percutaneous direct stick of cavities, organs, ducts, or tumors, for purposes of drainage, stenting, biopsy, or ablation. These types of procedures are more frequently guided by US, CT, or a combination of both. They are usually carried out in the Diagnostic Imaging Department.
Therefore, the IR teams performing all the spectrum of interventional procedures, like ours, are obliged to split their professional activities into two different and separate ambiances, resulting in a considerable logistic problem for professionals and patients.

Diagnostic Imaging Department × Cath Lab

Normally, imaging facilities are designed to receive many patients, allocated in several rooms that each contain a specific diagnostic imaging modality, such as X-ray, ultrasound, CT, MRI or densitometry. Most diagnostic imaging exams, even the more sophisticated, are quick and simple, with a high turn-over of patients. In contrast, some non-vascular interventions, performed under general anesthesia, can last morethan one hour, which can slow the flow of the imaging facility. Alongside this, if complications occur, like inadvertent arterial branch puncture with bleeding, the patient must be transferred urgently from the diagnostic imaging environment to the Cath Lab for embolization. So, the potential advantages of doing non-vascular interventions in the Cath Lab are obvious: sterile ambiance, trained team, equipment facilities, and catheters and devices availability to manage complex cases and life-threatening complications (Figure 1).
Figure 1c, d: Superselective catheterization and coil embolization of the false aneurysm

Alphenix 4D CT, a rational solution

Figure 2: Alphenix 4D CT , installed at Hospital Português do Recife
This is a powerful hybrid imaging system which has a fully operational ceiling mounted angiography system combined with an advanced dynamic volume CT scanner. It is an elegant and practical solution for more complex image- guided interventional procedures. The 4D CT has a specially designed extendable top table that easily slides into position during imaging for either the angiography C-arm or the CT scanner. The uniqueness of the 4D CT is the ability of clinicians to prioritize the patient experience and streamline their workflow during interventional procedures in a single clinical setting. The combination of both systems within one integrated imaging suite enables physicians to eliminate patient transfer during intricate procedures and confirm the effectiveness of the procedure.
The Real Hospital Português de Recife, which was founded in 1855, is the biggest private hospital in the Brazilian Northeast region. It has 850 beds. It’s Department of Cardiovascular and Interventional Radiology has always been at the cutting-edge of IR, and it is one of the most active reference centers on medical assistance and training in Brazil. Four angiography systems are currently in operation at Hospital, but only one of them incorporates a CT scanner: the Alphenix 4D CT system produced by Canon Medical Systems Corporation, Japan. This system was installed in October 2020, to meet the Hospital’s needs in the rapidly expanding field of IR, and provide facilities for all kinds of interventional procedures in just one single dedicated operating room. From October 2020 until June 2022, almost 1,700 patients were treated in this hybrid room (Figure.2).
Figure 2: Alphenix 4D CT , installed at Hospital Português do Recife

Emergency clinical cases: When time really matters

There are a special set of patients, with life-threatening clinical conditions, for whom prompt and precise interventional procedures can save lives and prevent disabling sequelae.
This group, represented by patients who present with multiple traumas, massive pulmonary embolism, ruptured aortic aneurysm, major gastrointestinal bleeding, and others, require rapid diagnostic confirmation and treatment strategy planning based on CT findings, followed by an immediate endovascular intervention in the Cath Lab. The Alphenix 4D CT is an unbeatable workflow, in order to avoid wasting time with the transfer of the patient from the CT room to the Angio suite and change of the respective professional team.
At our Hospital we are trying to modify the PERT (Pulmonary Embolism Response Team) protocol, for patients with suspected massive and sub massive pulmonary embolism. They are then directly admitted in the hybrid room, where they can receive CT scans and immediate endovascular thrombus aspiration and thrombectomy (Figure. 3).
A patient with ruptured aortic aneurysm submitted to the Alphenix 4D CT, for detailed anatomical evaluation, measurements, and EVAR planning and execution (Figure. 4).

Precision, efficacy and safety

IR has advanced in precision, efficacy and safety, thanks to the development of diagnostic imaging equipment that can identify culprit lesions, guide catheters and needles to the target, and evaluate treatment effectiveness.
The Canon Medical 4D CT has transformed our ability to perform interventional oncology procedures. Now, we can acquire high quality CT images quickly, that are not possible to obtain using “cone beam” technology.
In this way, we can accurately confirm treatment areas and recognize sources of non-target embolization, by performing fluoroscopic selective catheterization of the arterial branch that is believed to feed the lesion, and moving the table to obtain CT axial images, after intra-arterial administration of diluted iodinated contrast. If the tumoral nodule is not completely opacified, it means that another arterial feeder exists and must be found, catheterized and embolized, to avoid an incomplete response to the treatment (Figure. 5). However, if the CT scan shows opacification of a normal vital tissue or organ, a more selective catheterization must be done to avoid non-target ischemic complications.
Another advantage of the Alphenix 4D CT is the possibility to carry out multiple sequential procedures in the same room. It enables two or more Interventional procedures that require guidance through different imaging modalities to be performed without moving the patient from the table. The best example is the approach of certain HCCs that could benefit from the association of TACE and CT guided ablation (Figure. 5).

Final considerations

From left to right Dr. Jailton Luiz Cordeiro Junior (Anaesthetist), Dr. Ruth da Silva Pinheiro (IR), Dr. Carlos Abath, Dr. John Christian Alva Saavedra (IR).
Hybrid Room Angiography – CT technology is bringing Interventional Radiology to a new level of performance.
This is the perfect environment for a full-time interventional team, that cover all the spectrum of vascular and visceral interventional procedure. There is need to travel between the Diagnostic Imaging Department to the Cath Lab, and vice-versa, which wastes time and money, and exposes patients to unnecessary risks. In addition, the use of a high-quality CT integrated to DSA, provides an opportunity to implement new and innovative approaches for various diseases across multiple body systems. The correlation of CT, US and angiographic findings enable the physician to have a better comprehension of the pathologic process and rigorous judgement of the treatment effectiveness. Maybe, in the future, this technology will help to develop new treatment protocols, algorithms, and workflows, after scientific validation of the cumulative data.
Definitively, this hybrid CT-Angiography room will expand the horizons of Interventional Radiology, empowering even more the specialty among the population and medical community. //
From left to right Dr. Jailton Luiz Cordeiro Junior (Anaesthetist), Dr. Ruth da Silva Pinheiro (IR), Dr. Carlos Abath, Dr. John Christian Alva Saavedra (IR).
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