By Yuang-Seng Tsuei
Strictly speaking, the concept of hybrid operating rooms (ORs) in the field of neurosurgery is not new, but it has not been clearly defined. The term “hybrid ORs” is generally used to describe operating rooms designed to integrate diagnosis and surgery at the same time in a single room. Hybrid ORs allow the use of mobile C-arm fluoroscopy, which has been the mainstay of OR imaging since the late 1970s, as well as intraoperative CT scan and intraoperative MR, which have been widely applied since the late 1990s.
The modern hybrid OR can be divided into three types based on its facilities and surgical purpose, as follows: (1) digital angiography is used for neurovascular surgery and spinal surgery; (2) CT scan or MRI scan is applied in brain tumour surgery; (3) the O-arm system is specifically used in spinal surgery. A configuration of multimodality imaging tools, such as MRI, CT, and angiography in one room or an adjacent room may seem ideal for a wide variety of purposes, but high cost and inconvenience of application will limit its usage.
A neurosurgical hybrid OR equipped with an advanced digital angiography system may be considered to provide true “hybrid cerebrovascular surgery”, combining traditional open surgery and endovascular surgery simultaneously. Hybrid cerebrovascular surgery is a good alternative for treatment of cases considered difficult in the past and a less invasive approach to treat complex cerebrovascular disorders.
In our article (Shen SC et al, Journal of NeuroInterventional Surgery, 2015), we presented a case of intracerebral haemorrhage at the left cerebellum secondary to deep-seated dural arteriovenous fistula in the posterior fossa, Cognard type IV, with numerous tiny feeders from the ascending pharyngeal artery branches but without adequate arterial or venous route for endovascular embolisation. The hybrid surgery, combining keyhole pterional craniotomy and embolisation with n-butyl cyanoacrylate glue (NBCA) injection via direct cannulation of the periclival venous plexus obliterated the dural AVF. In another report (Shih YT et al, Neurosurgery, 2013), we described how we successfully revascularised the occluded internal carotid artery in three symptomatic cases using the hybrid technique, combining carotid endarterectomy and carotid stenting in the neurosurgical hybrid OR. These reports illustrate the usefulness of neurosurgical hybrid ORs for the treatment of complex cerebrovascular disorders, including haemorrhagic and ischaemic disorders.
In 2009, the neurosurgical hybrid OR with advanced imaging tools was established in our institution and it allows us efficient complementary application in various cerebrovascular surgeries. We summarise the potential advantages of hybrid OR as follows:
It allows real-time intraoperative angiography for aneurysm clipping or AVM/DAVF surgery, providing sufficient information to confirm surgical results, and thereby reducing the need for subsequent surgical revisions. Although intraoperative angiography can also be performed in conventional ORs with the mobile C-arm digital subtraction angiography system, modern hybrid ORs equipped with advanced imaging tools can provide high-quality intraoperative 2D/3D digital subtraction angiography images and a wide range of image-guided neurovascular procedures more conveniently.
It provides an effective, minimally invasive, alternative approach for treatment of cases considered difficult with either open surgery or endovascular intervention alone within a single session.
It can provide good rescue backup for open surgery and endovascular surgery, especially when a complication occurs during a neuroendovascular procedure. With conventional surgery, patients must be transported quickly from the traditional angiography suite to the OR for further rescue management. In such scenarios, both the transport itself and the delay in management can endanger the patient. In the modern hybrid OR, intraprocedural complications, such as arterial perforation during coiling, can be managed by quick conversion to open surgery without moving the patient. A zero mortality rate and a good neurological outcome (mRS ≤2) were achieved in our five cases.
It can provide real-time intraoperative CT-like images (Dyna-CT) at any time during surgery without the need to move the patient, thereby enabling the surgeon to react to complications or to confirm the proper position of implants or devices during the same session without the need for later revision.
We consider that microsurgical and endovascular therapies are complementary techniques for managing complex cerebrovascular disorders. It is important for cerebrovascular surgeons in training to master both microsurgical and endovascular techniques. Dual-trained vascular neurosurgeons who are expert in multiple treatment modalities can safely combine treatments when beneficial, as well as recognise the limitations of each therapeutic modality. The hybrid OR therefore requires the skills of dual-trained vascular neurosurgeons. Demand for hybrid ORs is expected to continue to increase, given the growing numbers of dual-trained vascular neurosurgeons and patients with complex neurovascular diseases requiring treatment that can best be delivered in a hybrid OR configuration.
In the development of an integrated operating room, good workflow and treatment quality depend on close cooperation among neurosurgeons, neuroradiologists, anaesthesiologists, medical engineers, and nurses. All staff need to modify the workflow to accommodate the integration of equipment in the hybrid OR.
In conclusion, the hybrid OR with an advanced angiography system allows new possibilities in joint open surgery and neuroendovascular surgery with high-quality intraoperative imaging for a wide range of image-guided neurovascular procedures which can be performed without moving the patient. It has the potential to be useful in the management of complex cerebrovascular diseases and can provide safe and effective treatment of neurosurgical patients.
Yuang-Seng Tsuei is the director of the Division of NeuroInterventional Surgery, Taichung Veterans General Hospital, Taiwan