Cerebral arteriotomy to retrieve an entrapped microcatheter after a partial cerebral arteriovenous malformation embolization
Correspondence Address: Source of Support: None, Conflict of Interest: None DOI: 10.4103/0028-3886.258029
Source of Support: None, Conflict of Interest: None
Embolization is one of the most common interventions to treat a cerebral arteriovenous malformation (AVM), and microcatheters are indispensable for this procedure. A microcatheter entrapment by Onyx or other embolic glue is an intraoperative complication occurring during cerebral AVM embolization, that has been reported in 2 out of 44 patients in one series. Usually, neurosurgeons manage this complication individually without surgical guidance. The overwhelming majority of these entrapped microcatheters are left in vivo, but the potential risk associated with this procedure is relatively high. So far, only one case has been reported, in which the entrapped microcatheter was removed through a microsurgical approach., Studies of the less reported approaches have been limited and outcomes are still elusive. The current report discusses a patient with an entrapped microcatheter after cerebral AVM embolization, from whom it was retrieved through a cerebral arteriotomy.
A 19-year old and previously healthy female patient presented with abrupt headaches and a brief episode of unconsciousness in November 2016. On the same day, she underwent an emergent cranial computed tomography (CT), which showed an intracerebral hematoma of around 25 cm3 in size in her left temporal and occipital lobe [Figure 1]a and [Figure 1]b. During the following days, she was treated mainly with intravenous mannitol, and several cranial CT scans confirmed the gradual absorption of the hematoma. In December 2016, she was referred to our institution. A moderate visual field defect affecting bilateral eyes was detected on a Humphrey visual field test, but there were no other signs or symptoms. A cerebral digital subtraction angiography (DSA) was used for further diagnosis, and an AVM was found in the left temporal and occipital lobe with two feeding arteries [left distal middle cerebral artery (MCA) and left distal posterior cerebral artery (PCA)] [Figure 1]a,[Figure 1]b,[Figure 1]c,[Figure 1]d,[Figure 1]e,[Figure 1]f,[Figure 1]g,[Figure 1]h,[Figure 1]i,[Figure 1]j. Accordingly, an endovascular embolization was used to treat this lesion and the distal MCA was first embolized, during which 1.1 mL of Onyx 18 (eV3 Inc., Irvine, CA, USA) was released into the AVM through a SONIC1, 2F25 microcatheter (Balt Extrusion, Montmorency, France), not exceeding a rate of 0.15 mL/min. The cerebral digital subtraction angiography (DSA) through the 6-Fr guiding catheter showed that blood flow into the AVM from the left distal MCA had been completely blocked [Figure 1]e, while blood flow into the AVM from the left distal PCA was still occurring [Figure 1]f. However, an attempt to gently withdraw the microcatheter under fluoroscopy [Figure 1]g failed, which suggested that its tip had been entrapped by the Onyx plug. Embolization was ceased and the microcatheter was transected at the level of the groin and pushed into the femoral artery. The intracranial microcatheter was detected by the cranial CT scan after AVM embolization [Figure 1]h,[Figure 1]i,[Figure 1]j,[Figure 1]k. In consideration of the thromboembolic risk due to the entrapped microcatheter in vivo, anticoagulation and antiplatelet agents were required. However, this increased the risk of hemorrhage from the partial embolized AVM. Subsequently, the patient's doctors decided to perform a cerebral arteriotomy to retrieve the entrapped microcatheter. As the blood flow to the residual AVM was markedly reduced after the first embolization, a staged embolization was scheduled to be performed rather than AVM resection.
The microcatheter retrieval surgery was performed with the patient under general anesthesia. A left tempoparietal craniotomy was performed with a 5 cm × 6 cm bone window. Under OH5 microscopy (Leica, Vizna, Germany), a cortical vessel located within the temporal lobe and congested by the Onyx plug was found [Figure 2]b, and then an intraoperative ultrasound was used to detect the signal of the microcatheter from the surface of a sulcus anterior to this vessel [Figure 2]a. After dissection of this sulcus, the silver-like microcatheter was visualized extravascularly [Figure 2]c and [Figure 2]d. The tip of the microcatheter tip was released from the Onyx plug sharply after the cerebral arteriotomy, and it was then withdrawn cranially [Figure 2]e and [Figure 2]f. At first, no resistance was felt but after around 20 cm of the microcatheter had been removed, the tip could no longer be moved. Accordingly, we tried to lengthen the incision proximally by several millimeters of the cerebral artery. Fortunately, the resistance disappeared and it was possible to withdraw the microcatheter further. This maneuver of gradual withdrawal was performed several times until the microcatheter was retrieved completely [Figure 2]g. As there were no visible branches originating from the incised segment of the artery, the proximal incision was clipped rather than sutured with a permanent aneurysm clip (Aesulcap, Tuttlingen, Germany) [Figure 2]h and [Figure 2]i. The length of the segment in vivo and the segment ex vivo were measured to ensure a complete retrieval. A total of 88 min were required to retrieve the entrapped microcatheter that had a length of 97 cm [Figure 2]j.
The patient had no any neurological deficits, such as hemiparesis and aphasia after the microcatheter retrieval, and had no other postoperative complications (in a follow-up duration of 2 months). The cranial CT scan on the day of the operation did not show an intracranial hematoma [Figure 1]l,[Figure 1]m,[Figure 1]n,[Figure 1]o. She took a dose of 100 mg oral aspirin per day for 2 weeks and 20 mg intravenous nimodipine per day for 1 week. She received other routine medications and nursing care as well. The cranial CT angiography, 1 week after the microcatheter retrieval, showed visible cerebral arteries with a normal lumen and a residual AVM. During the 2 months of postoperative follow-up, her outcome has been evaluated as modified Rankin scale (mRS) grade 0.
The causes of intravascular foreign body retainment are classified into three main categories: improper manipulation and usage, device defects, and the other individual factors. The risk of retrieving them is usually considered as being greater than the risk of leaving them in vivo; however, this factis not currently clear as yet. The potential risk of an unretrieved intravascular foreign bodies could be very high, and this problem can be lethal. Intravascular foreign bodies can cause thromboembolic events, which are particularly hazardous to the cerebral artery. Foreign bodies can also move and damage a vital organ or blood vessel. The U.S. Food and Drug Administration (FDA) has issued a warning regarding the dangers imposed by an unretrieved device fragment (FDA Patient Safety News: Show #71).
Management of these intravascular foreign bodies includes the administration of anticoagulation and antiplatelet regimens, and their endovascular and microsurgical retrieval. There are plenty of reports that foreign bodies in the peripheral artery or heart have been removed surgically. However, the reports of foreign body retrieval within the cerebral artery through an arteriotomy are extremely limited. The mechanisms of intravascular foreign body retainment include the breakage and migration of small segments of the microcatheter, migration of the embolic glue, and the presence of a misplaced coil following an AVM embolization or aneurysm coiling.,,, To the best of our knowledge, this is the second case of microcatheter retrieval after an AVM embolization through an arteriotomy, and also has some difference with respect to the first reported case, in which a microcatheter was found accidentally and withdrawn through the AVM rather than through the feeding artery.
There has been no commonly acknowledged indication for a microcatheter retrieval through a cerebral arteriotomy. In addition, there are not enough reports regarding the complications encountered due to microcatheter retrieval through a cerebral arteriotomy, and based on the existing reports, cerebral arteriotomy is a safe and effective procedure.,, As arterial injury, especially endothelium damage or dysfunction, is a potential complication, antiplatelet agents were used empirically by the authors.
We reported the second known case in whom a microcatheter that had become entrapped after AVM embolization was successfully retrieved through a cerebral arteriotomy and the patient had no postoperative neurological deficits or postoperative complications. However, this management strategy is still deemed controversial and more investigations must be completed in patients who develop the same complication during an AVM embolization.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
National Natural Science Foundation of China (No. 81760223,81560206).
Conflicts of interest
There are no conflicts of interest.
[Figure 1], [Figure 2]