Balloon-assisted technique for trapped microcatheter retrieval following onyx embolization. A case report

Retrieval of a Fractured Marathon Microcatheter Entrapped in Onyx Using a Novel Stentriever-Assisted Technique

BACKGROUND AND IMPORTANCE

Endovascular embolization using Onyx has been a major advancement in the treatment of cerebrovascular malformations. Microcatheter entrapment in Onyx is a procedural complication which can pose a thromboembolic risk to patients. There have been 4 retrieval techniques for intact microcatheters entrapped in Onyx previously described in the literature, which are summarized in this report. We present the first case using a novel stentriever-assisted technique to successfully and safely retrieve a fractured microcatheter entrapped in Onyx.

CLINICAL PRESENTATION

An adult patient with a Cognard IIa + b dural arteriovenous fistula (dAVF) underwent Onyx embolization. The microcatheter became entrapped and fractured while initially attempting removal. A stentriever was used off label to capture the fractured microcatheter and then a larger caliber microcatheter was railroaded over it. Retrieval of the fractured microcatheter by the stentriever was then facilitated by counter traction on the Onyx cast using the larger microcatheter.

CONCLUSION

This novel stentriever-assisted technique is a safe and effective rescue maneuver for retrieving a fractured microcatheter trapped in Onyx during embolization of dAVF. There is a need for further research and development of novel devices for retrieval of entrapped microcatheters.

Safety of the APOLLO Onyx delivery microcatheter for embolization of brain arteriovenous malformations: results from a prospective post-market study

BACKGROUND

Catheter retention and difficulty in retrieval have been observed during embolization of brain arteriovenous malformations (bAVMs) with the Onyx liquid embolic system (Onyx). The Apollo Onyx delivery microcatheter (Apollo) is a single lumen catheter designed for controlled delivery of Onyx into the neurovasculature, with a detachable distal tip to aid catheter retrieval. This study evaluates the safety of the Apollo for delivery of Onyx during embolization of bAVMs.

METHODS

This was a prospective, non-randomized, single-arm, multicenter, post-market study of patients with a bAVM who underwent Onyx embolization with the Apollo between May 2015 and February 2018. The primary endpoint was any catheter-related adverse event (AE) at 30 days, such as unintentional tip detachment or malfunction with clinical sequelae, or retained catheter. Procedure-related AEs (untoward medical occurrence, disease, injury, or clinical signs) and serious AEs (life threatening illness or injury, permanent physiological impairment, hospitalization, or requiring intervention) were also recorded.

RESULTS

A total of 112 patients were enrolled (mean age 44.1±17.6 years, 56.3% men), and 201 Apollo devices were used in 142 embolization procedures. The mean Spetzler-Martin grade was 2.38. The primary endpoint was not observed (0/112, 0%). The catheter tip detached during 83 (58.5%) procedures, of which 2 (2.4%) were unintentional and did not result in clinical sequelae. At 30 days, procedure related AEs occurred in 26 (23.2%) patients, and procedure-related serious AEs in 12 (10.7%). At 12 months, there were 3 (2.7%) mortalities, including 2 (1.8%) neurological deaths, none of which were device-related.

CONCLUSION

This study demonstrates the safety of Apollo for Onyx embolization of bAVMs.

CLINICAL TRIAL REGISTRATION

CNCT02378883.

Embolic Agents and Microcatheters for Endovascular Treatment of Cerebral Arteriovenous Malformations

Endovascular embolization of cerebral arteriovenous malformations (AVMs) originally entailed delivery of N-butyl cyanoacrylate glue to the nidus via a flow-directed microcatheter. Within the past decade, several new liquid embolic agents and novel microcatheter technologies have become available that have improved the ease of use and efficacy of endovascular therapies for AVMs. Nonadhesive copolymers, such as Onyx and Precipitating Hydrophobic Injectable Liquid, have largely replaced N-butyl cyanoacrylate given a lower risk of catheter entrapment. The emergence of balloon microcatheters has allowed for improved protection of the normal cerebral vasculature and has improved the penetration of liquid embolics into large AVMs, ultimately reducing procedure times and radiation exposure. Finally, several detachable tip microcatheters have been developed to facilitate removal of the catheter from hardened liquid embolic cast, preventing the morbidity associated with distal catheter entrapment. This article reviews the embolic agents and microcatheters currently available for the treatment of cerebral AVMs in the United States as well as the data demonstrating the safety and efficacy of these devices.

Occurrence and Management Strategies for Catheter Entrapment with Onyx Liquid Embolization

In June 2012, Food and Drug Administration (FDA) issued a warning about the risk of catheter entrapment associated with Onyx embolization. We used our experience, literature review, and FDA Manufacturer and User Facility Device Experience (MAUDE) data review to identify five strategies to address catheter entrapment: 1/. Surgical resection of vessel at point of entrapment of catheter and retraction from exterior portion at the femoral region; 2/. Advancing and closing the loop of snare over the entrapped catheter followed by retraction; 3/. Advancing the distal access catheter over the entrapped catheter and retraction with forward movement of the distal access catheters; 4/. Inflation of balloon catheter coaxial to the entrapped catheter with subsequent retraction; and 5/. Intravascular retention and internalization of microcatheter. In the MAUDE data, there were 77 reports of catheter entrapment with Onyx embolization; microcatheter was retracted by surgical excision in 15, endovascular snare or other retriever devices in 5, deliberately entrapped inside the vessel using stent in 1, and left without intervention within intravascular compartment in 27 patients.

Liquid embolization of brain arteriovenous malformation using novel detachable tip micro catheter: a technical report

BACKGROUND AND IMPORTANCE

Liquid embolization using Onyx® of brain arteriovenous malformations (AVMs) is sometimes limited by micro catheter retention by Onyx® cast during the disengagement process. Use of the new detachable tip micro catheter is presented in this report.

CLINICAL PRESENTATION

Two feeding arteries of a previously ruptured brain AVM in a 62-year-old man were embolized by Onyx 18 prior to surgery using the new Apollo™ micro catheter with the detachable-tip (30 mm) was utilized. The arterial feeders were accessed without difficulty by micro catheter, guided by 0.010" microwire. Onyx reflux around the distal end of the micro catheter was necessary for effective embolization of arteriovenous fistulous components of brain AVM. The micro catheter was successfully retracted after embolization in both feeding arteries, with distal end detachment seen in one but not the other arterial embolization. No arterial thrombosis, vasospasm, dissection, or rupture was seen at respective sites of disengagement.

CONCLUSION

Use of the new micro catheters with detachable-tip design allowed prolonged Onyx® injection times, safe micro catheter disengagement, without any limitations in accessing target arterial feeders.

Transarterial coil-augmented Onyx embolization for brain arteriovenous malformation. Technique and experience in 22 consecutive patients

Onyx has been widely adopted for the treatment of arteriovenous malformations (AVMs). However, its control demands operators accumulate a considerable learning curve. We describe our initial experience using a novel injection method for the embolization of AVMs. We retrospectively reviewed the data of all 22 patients with brain AVMs (12 men, 10 women; age range, 12-68 years; mean age, 43.2 years) treated by the transarterial coil-augmented Onyx injection technique. The size of the AVMs ranged from 25 mm to 70 mm (average 35.6 mm). The technical feasibility of the procedure, procedure-related complications, angiographic results, and clinical outcome were evaluated. In every case, endovascular treatment (EVT) was completed. A total of 31 sessions were performed, with a mean injection volume of 6.1 mL (range, 1.5-16.0 mL). An average of 96.7% (range 85%-100%) estimated size reduction was achieved, and 18 AVMs could be completely excluded by EVT alone. The results remained stable on follow-up angiograms. A procedural complication occurred in one patient, with permanent mild neurologic deficit. Our preliminary series demonstrated that the coil-augmented Onyx injection technique is a valuable adjunct achieving excellent nidal penetration and improving the safety of the procedure.

Entrapment of a micro-guidewire during stenting of basilar stenosis

Entrapment of a microwire related to intracranial endovascular therapy is an uncommon complication. A 64-year-old man with symptomatic basilar artery stenosis was treated with stenting. A 300 cm Synchro microwire became trapped in the P1 segment of the left posterior cerebral artery during the procedure. The decision was made to leave the microwire in place, considering that aggressive retrieval procedures could cause injury to the cerebral vasculature. The entrapped microwire was later inadvertently dislocated and removed while pulling the microwire back into the femoral artery with a looped catheter from the left femoral access. This demonstrates that, although entrapment of a microwire during endovascular therapy is a rare event, an optimal salvage technique needs to be explored further.

Entrapment of a micro-guidewire during stenting of basilar stenosis

Entrapment of a microwire related to intracranial endovascular therapy is an uncommon complication. A 64-year-old man with symptomatic basilar artery stenosis was treated with stenting. A 300 cm Synchro microwire became trapped in the P1 segment of the left posterior cerebral artery during the procedure. The decision was made to leave the microwire in place, considering that aggressive retrieval procedures could cause injury to the cerebral vasculature. The entrapped microwire was later inadvertently dislocated and removed while pulling the microwire back into the femoral artery with a looped catheter from the left femoral access. This demonstrates that, although entrapment of a microwire during endovascular therapy is a rare event, an optimal salvage technique needs to be explored further.

Safety of retained microcatheters: an evaluation of radiofrequency heating in endovascular microcatheters with nitinol, tungsten, and polyetheretherketone braiding at 1.5 T and 3 T

BACKGROUND

The use of ethylene-vinyl alcohol copolymer for liquid embolization of cranial vascular lesions has resulted in microcatheter fragments entrapped in patients following endovascular procedures. Undergoing subsequent diagnostic MRI examinations poses a safety concern due to the possibility of radiofrequency heating of the metallic braid incorporated into the microcatheter. Heating of nitinol, tungsten, and polyetheretherketone (PEEK) braided microcatheters was assessed and compared using a phantom model.

METHODS

Microcatheters coupled with fluoroptic temperature probes were embedded in a polyacrylamide gel within a head and torso phantom. Experiments were performed at 1.5 T and 3 T, analyzing the effects of different catheter immersion lengths, specific absorption rate (SAR) levels, short clinical scans, long clinical scans, and microcatheter fragment lengths.

RESULTS

The maximal increase in temperature for the nitinol braided microcatheter during a 15 min scan was 3.06°C using the T1 fast spin echo sequence at 1.5 T and 0.45°C using the balanced steady state free precession sequence at 3 T. The same scans for fragment lengths of 9, 18, 36, and 72 cm produced maximal temperature rises of 0.68, 0.80, 1.70, and 1.07°C at 1.5 T, respectively. The temperature changes at 3 T for these fragment lengths were 0.66, 0.83, 1.07, and 0.72°C, respectively. The tungsten and PEEK braided microcatheters did not demonstrate heating.

CONCLUSIONS

Substantial heating of nitinol braided microcatheters occurred and was a function of SAR level and geometric considerations. SAR and time limitations on MR scanning are proposed for patients with this microcatheter entrapped in their vasculature. In contrast, tungsten and PEEK braided microcatheters showed potential safe use in MRI.

Retained microcatheter after onyx embolization of intracranial arteriovenous malformation

Endovascular embolization is being increasingly used to treat intracranial arteriovenous malformations (AVMs). However, we experienced two patients with retained microcatheters after AVM embolization using Onyx.

Transarterial balloon assisted Onyx embolization of pericallosal arteriovenous malformations

SUMMARY

Preliminary experience using a balloon assisted technique (BAT) for embolization of arteriovenous malformations (AVM) is reported. Two patients with large pericallosal AVMs were successfully embolized with Onyx under Scepter C balloon catheter flow arrest.

CLINICAL PRESENTATION

One patient presented with a large intraventricular hemorrhage and hydrocephalus. The second patient presented with a long history of seizures and a small intracerebral hemorrhage. Both patients demonstrated extensive interhemispheric AVMs with multiple arterial feeders, predominantly from the pericallosal arteries.

INTERVENTION

A Marathon microcatheter was navigated into the target arterial feeders and a Scepter C occlusion balloon catheter was inflated immediately proximal. Under flow arrest, Onyx was injected via the microcatheter with excellent nidal penetration. In both cases, there was complete angiographic obliteration of the treated component of the AVM.

CONCLUSIONS

Onyx embolization under balloon catheter flow arrest allows for greater nidal penetration of embolic material and improved reflux control. The technique is limited by the current deliverability of balloon catheters and the potential risk for earlier embolization of dangerous anastomosis.