Balloons in endovascular neurosurgery: history and current applications

Pseudoaneurysm formation following transarterial embolization of traumatic carotid-cavernous fistula with detachable balloon: An institutional cohort long-term study

BACKGROUND

The goal of therapy for traumatic carotid-cavernous fistula (TCCF) is the elimination of fistula while maintaining patency of the parent artery. The treatment for TCCF has evolved from surgery to endovascular management using detachable balloons, coils, liquid embolic agents, covered stents, or flow-diverter stent through arterial or venous approaches. Despite the withdrawal of detachable balloons from the market in the United States since 2004, transarterial embolization with detachable balloons has currently remained the best initial treatment for TCCF in several countries. However, the pseudoaneurysm formation following transarterial detachable balloon embolization has rarely been observed in long-term follow-up.

AIM

To determine the occurrence and long-term follow-up of pseudoaneurysm after transarterial detachable balloon for TCCF.

METHODS

Between January 2009 and December 2019, 79 patients diagnosed with TCCF were treated using detachable latex balloons (GOLDBAL) of four sizes. Pseudoaneurysm sizes were stratified into five grades for analysis. Initial and follow-up assessments involved computed tomography angiography at 1 month, 6 month, 1 year, and longer intervals for significant cases. Clinical follow-ups occurred semi-annually for 2 years, then annually. Factors analyzed included sex, age, fistula size and location, and balloon size.

RESULTS

In our cohort of 79 patients treated for TCCF, pseudoaneurysms formed in 67.1%, with classifications ranging from grade 0 to grade 3; no grade 4 or giant pseudoaneurysms were observed. The majority of pseudoaneurysms did not progress in size, and some regressed spontaneously. Calcifications developed in most large pseudoaneurysms over 5-10 years. Parent artery occlusion occurred in 7.6% and recurrent fistulas in 16.5%. The primary risk factors for pseudoaneurysm formation were identified as the use of specific balloon sizes, with balloon SP and No. 6 significantly associated with its occurrence (P = 0.005 and P = 0.002, respectively), whereas sex, age, fistula size, location, and the number of balloons used were not significant predictors.

CONCLUSION

Pseudoaneurysm formation following detachable balloon embolization for TCCF is common, primarily influenced by the size of the balloon used. Despite this, all patients with pseudoaneurysms remained asymptomatic during long-term follow-up.

Long Vascular Sheaths for Transfemoral Neuroendovascular Procedures in Children

PURPOSE

To evaluate the safety and efficacy of long vascular sheaths for transfemoral neuroendovascular procedures in children.

MATERIALS AND METHODS

A retrospective evaluation of transfemoral neuroendovascular procedures in children <18 years, using long sheaths was undertaken analyzing procedure type, fluoroscopic times, technical success, access site and systemic complications. Twenty-seven consecutive procedures were included over a 2-year period. Mean age was 8.4 years (standard deviation [SD] 6.3) (range 17.0 months-16.3 years).

RESULTS

Patients were 44% female and mean weight was 35.0 kg (SD 22.8) (range 9.8-72.2 kg). A third of the procedures were performed in ≤15 kg children. The most common procedure was for embolization (n=13, 48.1%) and the most common indication was dual microcatheter technique (52%). The most common device used was the 5 Fr Cook Shuttle sheath. Mean fluoroscopy time was 61.9 minutes (SD 43.1). Of these procedures, 93% were technically successful. Femoral vasospasm, when present, was self-limiting. Complications (3/27, 11.1%) included groin hematoma (n=1), neck vessel spasm that resolved with verapamil (n=1), and intracranial thromboembolism (n=1), with no significant difference between the ≤15 kg and >15 kg subcohorts. There were no aorto-femoro-iliac or limb-ischemic complications.

CONCLUSION

Long vascular sheaths without short femoral sheaths can be safely used for pediatric neuroendovascular procedures as they effectively increase inner diameter access without increasing the outer sheath diameter. This property increases the range of devices used and intracranial techniques that can be safely performed without arterial compromise, thus increasing the repertoire of the neurointerventionist.

Balloon-Assistance for the Transcirculation Access of a Remodeling Balloon for Coiling of Wide-Necked Aneurysms: Report of Two Cases

Balloons are valuable tools in the armamentarium of a neurointerventionist. In this report, we describe 2 cases in which a balloon aided in the navigation of a second remodeling balloon through difficult vascular anatomy. The first case was a patient with a ruptured proximal posterior inferior cerebellar artery aneurysm and the second case was a patient with a ruptured anterior communicating artery aneurysm. In both cases, the coiling microcatheter and the remodeling balloon catheters were advanced through different vessels. The remodeling balloon reached the target location using a transcirculation approach, and the navigation of the remodeling balloon was aided by utilizing a second balloon. Challenging vascular anatomy is often encountered when performing neuroendovascular procedures. The strategy of using balloon assistance for the transcirculation access of a remodeling balloon can be used successfully in difficult situations to manage complex aneurysms.

Carotid cavernous fistula (CCF) treatment approaches: A systematic literature review and meta-analysis of transarterial and transvenous embolization for direct and indirect CCFs

BACKGROUND

Carotid Cavernous Fistulas (CCFs) are the result of an abnormal communication between the carotid artery and its branches and the venous system of the cavernous sinus. The mainstay of therapy for CCFs consists of transarterial or transvenous embolization, while other treatment options such as open surgery or radiosurgery are still utilized as second-line or adjuvant therapeutic options.

OBJECTIVE

Our aim was to systematically review and summarize available data regarding short- and long-term outcomes of all available treatment modalities for CCFs.

METHODS

This systematic review was conducted according to the PRISMA guidelines. A random effects model meta-analysis was conducted.

RESULTS

Fifty-seven studies comprising 1575 patients were included in this systematic review. Transarterial embolization for direct and indirect CCFs offered a complete obliteration rate of 93.93% (N = 589/627) and 81.51% (N = 119/146), respectively. Transvenous embolization for direct and indirect lesions achieved obliteration in 91.67% (N = 33/36) and 86.03% (N = 425/494) of patients, respectively. Comparison between transarterial and transvenous embolization did not reveal statistically significant differences in terms of fistula obliteration for direct (OR: 1.42; 95% CI: 0.23-8.90; I² 0.0%) and indirect CCFs (OR: 0.62; 95% CI: 0.31-1.23; I² 0.0%).

CONCLUSIONS

Endovascular embolization techniques are the preferred treatment modality for the management of CCFs. No differences were identified between transarterial and transvenous embolization by synthesizing studies with available data. Future prospective cohorts are warranted to compare the different materials and techniques implemented especially within the rapidly expanding realm of endovascular approaches.

Non-compliant and compliant balloons for endovascular rescue therapy of cerebral vasospasm after spontaneous subarachnoid haemorrhage: experiences of a single-centre institution with radiological follow-up of the treated vessel segments

BACKGROUND

For endovascular rescue therapy (ERT) of cerebral vasospasm (CVS) due to spontaneous subarachnoid haemorrhage (sSAH), non-compliant (NCB) and compliant (CB) balloons are used with both balloon types bearing the risk of vessel injury due to specific mechanical properties. Although severe delayed arterial narrowing after transluminal balloon angioplasty (TBA) for CVS has sporadically been described, valid data concerning incidence and relevance are missing. Our aim was to analyse the radiological follow-up (RFU) of differently TBA-treated arteries (CB or NCB).

METHODS

Twelve patients with utilisation of either NCB or CB for CVS were retrospectively analysed for clinical characteristics, ERT, functional outcome after 3 months and RFU. Compared with the initial angiogram, we classified delayed arterial narrowing as mild, moderate and severe (<30%, 30%-60%, respectively >60% calibre reduction).

RESULTS

Twenty-three arteries were treated with CB, seven with NCB. The median first RFU was 11 months after TBA with CB and 10 after NCB. RFU was performed with catheter angiography in 18 arteries (78%) treated with CB and in five (71%) after NCB; magnetic resonance angiography was acquired in five vessels (22%) treated with CB and in two (29%) after NCB. Mild arterial narrowing was detected in three arteries (13%) after CB and in one (14%) after NCB. Moderate or severe findings were neither detected after use of CB nor NCB.

CONCLUSION

We found no relevant delayed arterial narrowing after TBA for CVS after sSAH. Despite previous assumptions that CB provides for more dilatation in segments adjacent to CVS, we observed no disadvantages concerning long-term adverse effects. Our data support TBA as a low-risk treatment option.

Comaneci Device for Temporary Coiling Assistance for Treatment of Wide-Necked Aneurysms: Initial Case Series and Systematic Literature Review

BACKGROUND

Coiling of wide-necked aneurysms requires high-density packing of coils within the aneurysm, which necessitates adequate microcatheter access and navigability. The Comaneci device, introduced in the United States in 2019, is a retrievable stent that can be used as an adjunct to coiling of a wide-necked aneurysm without limiting flow. We present a case series and systematic review of use of this device.

METHODS

All cases involving use of the device at our institute between May 1, 2019, and April 30, 2020, were reviewed. A comprehensive systematic review of the literature was conducted using PubMed and EMBASE and a review of eligible article bibliographies.

RESULTS

Five patients underwent Comaneci-assisted wide-necked aneurysm coiling during the study period; 4 were treated via a radial artery approach, and 1 was treated via a femoral artery approach. Two patients presented with subarachnoid hemorrhage: 1 had a ruptured posterior inferior cerebellar artery aneurysm (Hunt-Hess 5, Fisher 4), and 1 had a ruptured middle cerebral artery aneurysm (Hunt-Hess 2, Fisher 1). Mean aneurysmal neck size was 4.4 ± 0.8mm; mean aspect ratio was 1.2 ± 0.3. Raymond-Roy 1 occlusion was achieved in all aneurysms except the posterior inferior cerebellar artery aneurysm. Systematic literature review identified 4 articles that found use of the Comaneci device to treat wide-necked aneurysms to be effective.

CONCLUSIONS

This device can be used with transfemoral and transradial approaches, allowing for continued flow through the parent vessel during the coiling procedure while providing a scaffold for dense coiling of the aneurysm and its neck.

Comparing Occlusive Balloon Performance Using 3-Dimensional Printed Models of Intracranial Aneurysmal Defects

OBJECTIVE

Balloon remodeling microcatheters are essential in assisting endovascular coiling of brain aneurysms, but the performance and pressure requirements of different balloon types when used in aneurysmal defects are currently unknown.

METHODS

We used Tinkercad (Autodesk, Montreal, Quebec) to create model vessels with aneurysmal defects and 3-dimensionally printed these designs with polylactic acid using the Ultimaker2 (Ultimaker, Geldermalsen, Netherlands). We constructed a pressurized box capable of reaching physiologic pressures that housed our vessels and then tested compliant remodeling balloons under fluoroscopy from 3 manufacturers: Hyperglide (Medtronic, Minneapolis, Minnesota, USA), Transform (Stryker Neurovascular, Fremont, California, USA), and Scepter C (Microvention, Tustin, California, USA). Each balloon was inflated to a nominal and supranominal point at each defect, and at each inflation the maximum diameter of the balloon and internal balloon pressure were recorded. The Phillips Intellivue (Phillips, Amsterdam, The Netherlands) monitor was adapted for internal balloon pressure monitoring. A multivariate linear regression analysis was performed to model balloon compliance (balloon diameter divided by pressure).

RESULTS

Multivariate regression modeling demonstrated the Scepter balloon had significantly greater compliance compared with both the Hyperglide and Transform balloons (P < 0.001). In addition, we found that Scepter balloons had higher compliance in larger defects compared with the other types of balloons and performance differences based on vessel size.

CONCLUSIONS

Scepter balloons require less pressure compared with their counterparts to adequately deform through model defects, specifically in larger aneurysm necks in smaller vessel diameters. This result could inform operators of optimal balloon type and size when trying to minimize balloon pressure in fragile brain aneurysms.

National Trends in the Treatment of Ruptured Cerebral Aneurysms in Korea Using an Age-adjusted Method

BACKGROUND

Two primary treatment methods are used for ruptured cerebral aneurysms, surgical clipping and endovascular coiling. In recent decades, endovascular coiling has shown remarkable progress compared to surgical clipping, along with technological developments. The aim of this study was to investigate the recent trends in treatments for ruptured cerebral aneurysms in Korea.

METHODS

The data were obtained from the National Health Insurance database. We evaluated the trends in endovascular coiling and surgical clipping for ruptured aneurysms for the period 2000-2017. We obtained the number of prescriptions with International Classification of Diseases, 9th Revision, clinical modification codes related to nontraumatic subarachnoid hemorrhage and prescription codes S4641/4642 for surgical clipping and M1661/1662 for endovascular coiling. The medical expenses for each prescription were also obtained. The primary outcomes included the cumulative number of patients, patient rates per 100,000 people, and the correlation between patient rates and the percentage of the population in each age group.

RESULTS

In the case of surgical clipping, there were no increasing or decreasing trends in the cumulative number of patients when the population/age group was ignored. When examining the trends in patient rates per 100,000 population at each year in male, there was no increasing or decreasing trend in the number of surgical clippings between the age groups, in spite of a decreasing tendency in the number of surgical clipping in male in their 40s and older than 60. In females, the surgical clipping rates tended to decrease only in patients older than 60 years, but there was no tendency to increase or decrease in the other ages. In contrast, the cumulative number of patients who underwent endovascular coiling for ruptured cerebral aneurysms increased year by year regardless of the population/age group. In both male and female, there was no increasing or decreasing trend only in the group aged 40 or younger and there was an increasing tendency in the rest of the age groups. In the trend of medical expenses, both the cost of surgical clipping and endovascular coiling showed increases. Specifically, the medical expense trend in endovascular coiling increased more rapidly than that for surgical clipping.

CONCLUSION

There was a significant increase in the proportion of patients with ruptured aneurysms undergoing endovascular coiling between 2010 and 2017, whereas the use of surgical clipping decreased. The endovascular coiling was significantly increased in all age groups and surgical clipping was decreased in all age groups, especially in patients under 50 years of age.

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.

Advances in endovascular aneurysm management: coiling and adjunctive devices

Endovascular coil embolisation continues to evolve and remains a valid modality in managing ruptured and unruptured cerebral aneurysms. Technological advances in coil properties, adjunctive devices and interventional techniques continue to improve long-term aneurysm occlusion rates. This review elaborates on the latest advances in next-generation endovascular coils and adjunctive coiling techniques for treating cerebral aneurysms.

Use of a Polytetrafluoroethylene-Coated Vascular Plug for Focal Intracranial Parent Vessel Sacrifice for Fusiform Aneurysm Treatment

BACKGROUND

Fusiform intracranial aneurysms are challenging due to the circumferential nature of the disease. Endovascular parent vessel sacrifice with coils may be a treatment option, but typically requires a long vessel segment to induce complete cessation of flow.

OBJECTIVE

We evaluate early clinical experience with the intracranial use of the microvascular plug (MVP; Medtronic, Dublin, Ireland) device and to compare to previous coil-only techniques for vertebral artery sacrifice for fusiform vertebral aneurysm.

METHODS

We reviewed patients treated with the MVP for intracranial aneurysms at our institution. As a case-control study, we located 6 control patients who underwent coiling alone for vertebral artery sacrifice. The number of implants, fluoroscopy time, and procedural charges were compared using unpaired t -tests.

RESULTS

Twelve patients underwent vessel sacrifices with MVP. Eight were for vertebral artery dissecting aneurysms. Comparing only vertebral aneurysms, the mean implants was 7 in the MVP group (n = 8) and 19.5 in the coiling group (n = 6; P = .0015). Mean fluoroscopy time was 17.62 min in the MVP group compared to 24.2 min in the coiling group ( P = .07). Procedural costs were less in the MVP group ($19 667.38) compared to coiling ($44 909.50, P = .05). There were no technical failures and no cases with persistent flow in the parent vessel at the end of the procedure.

CONCLUSION

The MVP is a cost-effective device for focal intracranial vessel occlusion in select patients. This is an important tool for cerebrovascular surgeons, particularly in cases of ruptured dissecting vertebral aneurysms.

Injection of N‑butyl Cyanoacrylate Through a Dual-Lumen Balloon for Embolization of High-flow Intranidal Fistulas in Brain Arteriovenous Malformations: Technical Note

PURPOSE

N-butyl cyanoacrylate (NBCA) glue is a valuable liquid embolic agent for the endovascular treatment of brain arteriovenous malformations (BAVM). The use of NBCA carries a risk of embolic agent reflux and distal migration with ensuing possibility of venous drainage compromise. The aim of this technical note is to describe a single center case series of high-flow intranidal fistulas embolized though a dual lumen balloon under local flow-arrest conditions.

METHODS

This article presents a retrospective description of a case series including five NBCA injections through a dual lumen balloon performed by a single operator in three patients with BAVM. Demographic, clinical, imaging and procedure-related data are reported.

RESULTS

The three patients presented with ruptured BAVMs. Of the patients, one underwent proximal flow-related ruptured aneurysm coiling before planned BAVM embolization. In the three patients, staged BAVM embolization as a first line treatment was decided. Preliminary embolization of high-flow BAVM fistulas by NBCA using a dual lumen balloon under local flow-arrest conditions was performed and five separate injections were carried out without any complications. No balloon entrapment or rupture was observed.

CONCLUSION

High-flow BAVM fistulas can be treated with NBCA embolization using a dual lumen balloon under local flow-arrest conditions.

Characterization of a reversible thermally-actuated polymer-valve: A potential dynamic treatment for congenital diaphragmatic hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a fetal defect comprising an incomplete diaphragm and the herniation of abdominal organs into the chest cavity that interfere with fetal pulmonary development. Though the most promising treatment for CDH is via interventional fetoscopic tracheal occlusion (TO) surgery in-utero, it has produced mixed results due to the static nature of the inserted occlusion. We hypothesize that a suitable noninvasively-actuatable, cyclic-release tracheal occlusion device can be developed to enable dynamic tracheal occlusion (dTO) implementation.

OBJECTIVE

To conduct an in-vitro proof-of-concept investigation of the construction of thermo-responsive polymer valves designed for targeted activation within a physiologically realizable temperature range as a first step towards potential development of a noninvasively-actuatable implantable device to facilitate dynamic tracheal occlusion (dTO) therapy.

METHODS

Six thermo-responsive polymer valves, with a critical solution temperature slightly higher than normal physiological body temperature of 37°C, were fabricated using a copolymer of n-isopropylacrylamide (NIPAM) and dimethylacrylamide (DMAA). Three of the valves underwent ethylene oxide (EtO) sterilization while the other three served as controls for EtO-processing compatibility testing. Thermal response actuation of the valves and their steady-state flow performances were evaluated using water and caprine amniotic fluid.

RESULTS

All six valves consisting of 0.3-mole fraction of DMAA were tested for thermal actuation of caprine amniotic fluid flow at temperatures ranging from 30-44°C. They all exhibited initiation of valve actuation opening at ~40°C with full completion at ~44°C. The overall average coefficient of variation (CV) for the day-to-day flow performance of the valves tested was less than 12%. Based on a Student t-test, there was no significant difference in the operational characteristics for the EtO processed versus the non-EtO processed valves tested.

CONCLUSIONS

We successfully fabricated and demonstrated physiological realizable temperature range operation of thermo-responsive polymer valves in-vitro and their suitability for standard EtO sterilization processing, a prerequisite for future in-vivo surgical implantation testing.

Onyx embolization of a pial AV fistula with a giant venous varix using a flow-directed Scepter balloon catheter: Technical note

BACKGROUND AND IMPORTANCE

Pial arteriovenous fistulas (AVFs) of the brain are treacherous lesions that can be challenging to treat because of high risk of hemorrhage. We report on a rare case of a pial AVF with a giant venous varix as a draining vein treated successfully with flow-directed balloon-assisted Onyx embolization.

CLINICAL PRESENTATION

A 56-year-old female with headaches underwent brain magnetic resonance imaging, which demonstrated a 4 cm aneurysmal malformation in the right temporal lobe. A diagnostic cerebral angiogram demonstrated a right temporal pial AVF fed by an enlarged right posterior cerebral artery with drainage into a giant venous varix. Onyx embolization was curative using a flow-directed Scepter balloon catheter.

CONCLUSION

Flow-directed balloon-assisted Onyx embolization can be highly successful for the curative embolization of pial AVFs. Balloon application changes the nature of the lesion from high-flow-high risk to no-flow-low-risk. Using a flow-directed technique with balloon microcatheters may help minimize the risk of intracranial vascular injury.

Delayed massive epistaxis from traumatic cavernous carotid false aneurysms: A report of two unusual cases

Introduction Blunt head trauma can injure the cavernous segment of the internal carotid artery (ICA). This may result in a carotid cavernous fistula (CCF). Rarely, a traumatic aneurysm may bleed medially causing massive epistaxis. Case presentation We present two cases of traumatic intracavernous carotid pseudoaneurysms with delayed massive epistaxis. The patients were managed with endovascular treatment involving coil embolization with parent vessel sparing and detachable balloon occlusion with carotid sacrifice. Early clinical outcome was good in both patients. Wherever possible, the CARE¹ guidelines were followed in the reporting. Conclusion These cases illustrate the delayed nature of traumatic aneurysms and the need for a high index of suspicion in the presence of skull base fractures. The use of endovascular detachable balloon occlusion and coil embolization treatment with parent vessel preservation is shown.

Early Experience with the TransForm™ Occlusion Balloon Catheter: A Single-Center Study

BACKGROUND AND OBJECTIVE

Balloon-assisted coil embolization has become an important adjunct in the endovascular treatment of intracranial aneurysms. The management of broad-necked cerebral aneurysms is technically perplexed due to a variety of factors, which include the difficulty in defining the aneurysm-parent vessel interface angiographically and problems in achieving complete aneurysmal occlusion. This could later predispose to regrowth or recanalization. We sought to determine the safety and efficacy of the TransForm™ occlusion balloon catheter (TOBC) for the coiling of intracranial aneurysms at our institute.

METHODS

A retrospective review was performed to identify TOBC cases between May 1, 2013, and April 30, 2014.

RESULTS

A total of 24 TOBC cases were identified. In 23 cases, the TOBC was used for balloon-remodeled coil embolization, and in 1 case, it was used for vasospasm treatment alone. Out of the total 24 cases in which the TOBC was used, 16 (66.6%) were ruptured aneurysms. Stents were used in 6/23 (26%) cases. In all cases, the balloon could be placed as intended. The inflation and deflation times ranged from 3 to 4 s. No serious complications were noted. In the experience of the authors, the balloon performed the intended role in most cases.

CONCLUSIONS

This series shows that the TOBC is feasible, safe and useful in the treatment of cerebral aneurysms. The balloon was traceable to the intended site and the preparation, inflation and deflation times were short. We believe that the TOBC has effective utility in treating broad-necked and small aneurysms.