Part 2: The development and advancement of the detachable balloon catheter; a historical and technical review

Abstract

The detachable balloon catheter (DBC) was a revolutionary technique for the treatment of cerebrovascular pathologies. It was used to treat carotid cavernous fistulas (CCFs), vertebro-jugular fistulas, arteriovenous malformations (AVMs), and aneurysms. The DBC became the foundation for neurointerventional techniques, leading to the development of coil embolization and bioactives. Our team selected relevant articles from PubMed published between 1974 and 2023. Articles were excluded if they did not discuss the use or development of the detachable balloon catheter or subsequent technologies. The DBC was used to occlude vessels, either temporarily or permanently. Dr Gerard Debrun implemented findings from Dr Fedor Serbinenko's research to develop an intravascular detachable balloon technique. He developed many variations using type I and type II balloon catheters that differed in size, length, and material, allowing for the personalization of treatment based on the lesion. This revolutionary thinking showed that every pathology has a different shape and anatomy that require a unique approach. The DBC would offer the first alternative to the conventional practice of carotid occlusion in CCF treatment at the time. The DBC would later be used in aneurysm occlusion and the embolization of AVMs, with additional benefit in traumatic vascular sacrifice. Although the DBC has largely been replaced, it is still useful in a small subset of patients, and has financial incentive as it is more affordable than coils. This technique was a monumental stride in the history of neurointervention and helped propel the specialty to the current era of patient-specific interventions.

Introduction

NeuroInterventional surgery is a relatively novel subspecialty that began to expand in the 1970s. In 1939, Werner et al. reported on what is thought to be the first endovascular treatment of a large, cavernous carotid artery aneurysm, using roughly 30 feet of silver wire to fill the lesion. ¹ Reports of the first detachable vascular balloon catheter can be traced back to the 1960s when it was introduced in multiple studies. ² In 1964, Luessenhop and Velasquez successfully performed the first microcatheterization for temporary balloon occlusion of a posterior communicating artery aneurysm. ³ The majority of the Russian studies released at this time were preliminary reports of an intravascular balloon catheter used to treat various cerebral pathologies, including vascular lesions and cerebral neoplasms. ⁴

A monumental study in 1974 proved the safety and efficacy of balloon catheters in the occlusion of cerebral vessels in over 300 patients. ⁵ Dr Fedor Serbinenko of the Burdenko Neurosurgical Institute used four different sized balloons to occlude the internal carotid artery (ICA), all the way to the branches of the anterior (ACA), middle (MCA), and posterior cerebral arteries. The balloon could be used to temporarily or permanently occlude a vessel based on the pathology being treated and was thought to be the foundation of endovascular neurosurgical treatment.

The Burdenko Institute became a hot spot for foreign physicians who wanted to observe novel NeuroInterventional techniques. ⁶ Having worked on his own version of a detachable latex balloon catheter, Dr Gerard Debrun visited the institute to learn from Serbinenko. Debrun's detachable balloon would soon be used in the treatment of carotid cavernous fistulas (CCFs) and giant intracavernous aneurysms. ² Although this technique has since been replaced by the Guglielmi detachable coil, this was a monumental stride in the history of neurointervention. ⁷ This article is a follow up to Part 1: Pushing the Boundaries of NeuroInterventional Surgery; A Historical Review of the Work of Dr Gerard Debrun, which described the historical development of neuroendovascular surgery and its early techniques. The goal of this article is to discuss the development and advancement of the detachable balloon catheter and its impact on the interventional treatment of various cerebral vascular pathologies.

Methods

Our team selected relevant articles from PubMed published between 1974 and 2023. Various archived blueprints and patents from our institution were also reviewed. Articles were excluded if they did not discuss the use or development of the detachable balloon catheter or subsequent technologies. All included articles discuss the development and use of the detachable balloon catheter for various cerebral vascular pathologies.

Discussion

Background

The detachable balloons were made from sleeves composed of materials such as latex or silicone, with a narrow proximal section that attached to the catheter and an expandable distal section that varied in shape. The diameter of the balloon tips ranged from 0.3 to 2.0 mm. Some of the sleeves contained an additional flap for the inclusion of a small cylinder so that the course of the balloon can be followed on fluoroscopy, without the balloon having to be inflated with contrast. ⁸ The detachable balloon technique involves an inflatable balloon that is fitted over a delivery catheter. Typically, the diameter of the balloon measures larger than the chosen vessel to ensure proper occlusion (Figure 1).

Figure 1.

Design blueprint for one of Dr. Debrun's homemade detachable balloon catheters, which varied based on size, length, and material (Courtesy Department of Neurosurgery, University of Illinois Chicago).

Once the balloon is positioned intravascularly, contrast is injected via the catheter to inflate the balloon. After the initial contrast injection, the contrast is withdrawn, deflating the balloon. Following this, a polymerizing substance (such as silicone) is injected, to re-inflate the balloon. After aspirating the contrast, there is a small amount of contrast that remains in the catheter that cannot be aspirated, which is referred to as “dead space.” When the polymerizing agent is injected, it pushes the remaining contrast into the balloon again. To avoid this issue, a dual lumen catheter can be used to detach a balloon only filled with the polymerizing agent. Once inflated and satisfactory position and stability of the balloon has been confirmed, the balloon is ready for detachment. ⁸ The earlier catheters can be characterized into type I and type II, each serving a distinct purpose as well as a unique method of detachment (Figure 2).

Figure 2.

(A) Type I catheters had a balloon that detached without requiring a second catheter. (B) Type II catheters were more durable, did not carry risk of detaching prematurely, and required the use of a second catheter for detachment (Gerard Debrun: Treatment of Carotid Cavernous and vertebral fistula; Vascular Malformations, edited by R. R. Smith, A. Haerer and E.F. Russel. Raven Press, New York, 1982).

Type I catheters were used by Serbinenko and offered the ability of detachment and maneuverability. The latex sleeve is introduced to the Silastic tube and attached using its intrinsic elasticity. The balloon can be easily detached from the catheter by simply pulling back on the catheter, which unfavorably poses the risk of detaching prematurely and damaging the vascular lesion. Since earlier versions did not have the balloon physically tied to the catheter, detachment was a real risk if the balloon was not glued to the tip of the tubing, as multiple inflations and deflations led to the loss of the latex sleeve's elasticity.

In 1974, Serbinenko et al. reported the largest case series to date of patients (n = 304) treated with type I detachable balloon catheterization and the occlusion of major vessels. In this study, self-manufactured, silicone, or latex balloon catheters compatible with ordinary angiographic needles that were used to access the carotid artery directly were used. This technique involved the use of two balloons; one balloon was used solely for vessel occlusion, while the other was used for occlusion or the passage of liquids such as contrast via a second lumen. ACA catheterization, for example, would involve the use of one balloon to occlude the main branch of the MCA to allow for passage of contrast into the ACA for superior visualization. Detachment of the balloon could be performed by pulling traction on the catheter. ⁹

Serbinenko obtained remarkable results, with only two patients dying due to middle cerebral artery thrombosis. ⁵ This study emphasized the utility of the balloon catheter in a variety of settings including: (1) occlusion of the ICA to allow angiography of the external carotid artery (ECA), (2) occlusion of the ECA branches, (3) investigating arteriovenous (AV) and CCFs, (4) aneurysm occlusion, and (5) prevention of blood flow to aneurysms and fistulas. The use of balloon catheters to occlude cerebral vessels avoided various complications such as decreased cerebral blood supply or undesirable carotid sinus reflex reactions. ⁵

Type II balloon catheters were much more durable and did not hold a risk of detaching prematurely but required the use of a second catheter to detach the balloon. The proximal portion is tied with latex thread to the tip of a Teflon catheter, which is inserted into a curved polyethylene catheter built for maneuverability. To detach a type II balloon, the second coaxial catheter is slid over the first catheter until it contacts the base of the balloon, thus securing it in place. Once this has been done, the first catheter can be withdrawn while the second catheter maintains position of the balloon, subsequently securing and detaching the balloon. If the procedure involves glue embolization, the second catheter may be unnecessary if the balloon is glued into place. Both systems are continually flushed with heparinized saline, with the addition of systemic heparinization to decrease clot formation inside the system. Hypocoagulability is reversed at the end of the procedure with protamine sulfate.

Debrun's detachable catheters were completely homemade, as well as sterilized in-house. He had designed many different molds for the balloons that varied based on size, length, and material, allowing for the personalization of treatment, as can be seen in part 1. Based on the patients, their lesion, and subsequent anatomy, Debrun would use the appropriately sized mold to make the most efficacious balloon (Figure 1(A)). In 1979, Polish engineer Leopold Plowiecki of the medical device company Balt Extrusion, would be one of the first to commercially manufacture balloons and their delivery catheters with the help of Dr Serbinenko and Dr Merland from Paris. ¹⁰ The newer, commercially manufactured balloons used two balloons that are placed back-to-back, proximally and distally. The purpose of the proximal balloon is to minimize the migration of the distal balloon, designating it as a “safety net.” When satisfactory position and inflation are achieved in the target vessel, the distal balloon can be detached by pulling back on the catheter, while the proximal balloon ensures flow arrest, and is also removed following the detachment of the distal balloon. ⁸

The Gold Valve detachable balloon was one of the first name-brand balloons available, although this balloon is no longer available in the United States. After this, the Gold Balloon was created by Balt and would become available for use in Europe, becoming one of the only commercially available detachable balloons on the market due to its flexibility for use with various microcatheters. The commercialization of balloon catheters allowed for the continued popularization and use of this technique all around the world. ¹¹

Carotid-cavernous and vertebro-jugular fistulas

After visiting the Burdenko institute in 1974, Debrun implemented findings from Serbinenko's research to develop an intravascular detachable balloon technique of his own for the treatment of CCFs and vertebro-jugular fistulas (Figure 1(B)). Using the dual catheter technique (type II balloon), 20 patients with CCFs were treated, 17 of which were posttraumatic. To detach the balloon, a second catheter was introduced over the first catheter to the base of the balloon, securing it in place. Once this has been done, the first catheter can be withdrawn until the balloon is felt to detach. All patients were treated successfully with only one complication and no mortality. In addition, three patients with vertebral fistulas were also successfully treated with the use of detachable balloons, all three being asymptomatic at the time of follow up.

Efforts to continue developing and expanding the applications of the detachable latex and newer silastic balloon catheters led to a 1981 study comparing outcomes between three approaches for detachable balloon occlusion of CCFs: (A) endarterial route; (B) venous route through the jugular vein, the inferior petrosal sinus, and the cavernous sinus; or (C) surgical exposure of the cavernous sinus ¹² (Figure 3). Debrun et al. proposed superiority of the endarterial approach due to reduced invasiveness and superior rates of CCFs occlusion when compared to the transvenous approach. The detachable calibrated leak-balloon system proved to be effective in allowing for the superselective catheterization of the distal branches of the ECA, while minimizing the risk of dissection and vasospasm.^13,14

Figure 3.

(A) Left ICA angiogram (anteroposterior) and lateral and (B) demonstrating a direct CCF with severe venous congestion and retrograde cortical venous reflux. (C) Fluoroscopic imaging after detachable balloon placement in the cavernous sinus (white arrow). (D) Right ICA angiogram (anteroposterior) and lateral and (E) after embolization of the CCF with detachable balloon showing no evidence of any early venous drainage. (Permission to reproduce granted from Neurosurgery Journal, Wolters Kluwer Health, Inc. CCF: carotid cavernous fistula; ICA: internal carotid artery).

In 1988, Debrun published a seminal study assessing the optimal treatment for CCFs based on the type A–D classification system introduced by Barrow et al. in 1985. ¹³ This study provided evidence supporting the use of detachable balloon catheters as the optimal treatment method for type A fistulas (direct connection between the ICA siphon and the cavernous sinus through a single arterial tear) by obliterating the connection using the detachable balloon itself. Type B fistulas (fed by meningeal branches of ICA) were not encountered in the study. Type C fistulas (supplied exclusively by ECA feeder vessels) were better treated by embolization of the ECA branches. Type D fistulas (supplied by meningeal feeder vessels from both the ICA and ECA, often bilaterally) proved to be the most challenging, typically requiring the use of both embolization and an open, surgical approach. ¹⁵ In 1989, Dr Debrun and his colleagues introduced a novel transvenous approach to the cavernous sinus accomplished by advancing a detachable balloon catheter through the superior ophthalmic vein. In the report they described the approach as a safe and effective treatment of CCFs in cases which were not suitable for treatment by standard techniques of endoarterial balloon occlusion or embolization. ¹⁵

The treatment of CCFs with a balloon catheter did not go without its share of complications. Three separate complications were reported: the development of a pseudoaneurysm, stenosis or occlusion of the ICA, and balloon rupture. The authors attribute the pseudoaneurysm to extravasation of contrast through the balloon, while the occlusion of the ICA occurred during introduction and filling of the balloon. As the balloon enters a narrow fistula, there is a very high risk of balloon rupture, as the narrow entrance does not allow for the balloon to inflate symmetrically. ¹⁶ Another issue that occasionally arose while treating CCFs was that a small proportion of the fistulas were unable to be treated by the standard endovascular treatment alone, necessitating the support of an open surgical approach. This was highlighted by Debrun et al. in 1989, who reported 10 patients out of a cohort of 143 CCFs that required additional surgical interventions. ¹⁷ This was due to various causes including: (1) incomplete closure of the fistula due to an issue with the balloon (deflation, migration) with ICA occluded (n = 3), (2) failure to occlude fistula after both arterial and venous approaches were attempted (n = 1), (3) hairpin loop of cervical ICA (n = 1), (4) failure of previous trapping procedures (n = 3), and (5) failure to cure spontaneous CCF of the dural type and ECA embolization feeder vessels (n = 2) (Figure 4). All 10 patients were treated appropriately, although complications such as contralateral hemiparesis and ocular proptosis temporarily occurred, but eventually resolved in all patients. This case series demonstrated that treatment of CCFs is complex, with each case presenting a unique challenge based on the anatomy of the fistula and its surrounding tissues and vessels.

Figure 4.

(A) Right ICA angiogram (anteroposterior) and lateral and (B) showing a direct CCF and early opacification of both cavernous sinuses with no antegrade flow beyond the cavernous sinus. Because the patient had no neurological symptoms with no contribution from the right ICA, no balloon test occlusion was performed before sacrifice of the ICA. (C) Fluoroscopic view of the neck showing the placement of three detachable balloons (white arrows) in the cervical ICA and into the cavernous sinus. (D) Right common carotid artery angiogram confirming complete occlusion of the right ICA with no reconstitution of the cavernous fistula from the external carotid artery. (E) Contralateral left ICA injection. Both hemispheres are filling from the left ICA injection. No retrograde filling of the fistula is seen. (Permission to reproduce granted from Neurosurgery Journal, Wolters Kluwer Health, Inc. CCF: carotid cavernous fistula; ICA: internal carotid artery).

Arteriovenous malformations

An additional application for detachable balloon catheters included treatment of cerebral arteriovenous malformations (AVMs). The preferred intervention for the treatment of AVMs involves the complete surgical resection of the malformation, therefore the endovascular approach alone was employed only when surgery was contraindicated. When treating endovascularly, two balloon types could be implemented. The first was a twin-lumen balloon catheter, while the second was a single-lumen catheter with a latex or silicone graduated-leak balloon.

Graduated or calibrated leak refers to a leak through the tip of the balloon once it has been inflated to a particular pressure. To add a calibrated-leak mechanism to the balloon, the narrow aspect of the balloon is cut and perforated by a small gauge needle. When injecting a liquid through the lumen into the balloon, the pressure initially inflates the balloon, while its intrinsic elasticity keeps the tip closed. As the pressure continues to increase, the leak can open, allowing for the leakage of contrast material or in this case, an embolizing agent. ¹⁴ In the treatment of cerebral AVMs, the second type of catheter was preferred, as the polymerizing agent had a propensity to stick to catheters of the first type, preventing withdrawal. ¹⁴ There are two technical options for the embolization of AVM: a latex detachable calibrated-leak balloon with a Teflon catheter and a latex nondetachable calibrated-leak balloon with a silastic catheter. The latex detachable calibrated-leak balloon with a Teflon catheter was primarily used for the embolization of ECA branches but was too stiff to navigate the segments of the ICA. The pliable nature of the nondetachable balloon with a silastic catheter allowed for intracranial embolization.

If the balloon was composed of latex, the optimal time frame for injection of an embolizing agent was 1 mL over 3 to 5 seconds. This allowed for the maintenance of an inflated balloon, as well as adequate delivery of the agent in a short period of time. On the other hand, if the balloon was composed of silicone, the injection rate should be 1 mL over 20 to 30 seconds to reduce the risk of rupture. Latex balloons were preferred due to their ability to be inflated and deflated multiple times without a decrease in compliance or integrity. ¹⁸

The goal of cerebral AVM embolization is to chemically occlude afferent feeder vessels as well as the lesion itself to prevent collateral revascularization. The most efficient way to accomplish this is to release an embolizing agent that polymerizes rapidly within the interior of the targeted malformation. The microcatheter can be advanced distally by using various techniques, including rapid injection of contrast, saline, or dextrose propulsion, or manipulating the introducer. ¹⁸ Once the balloon has been positioned as close as possible to the nidus of the lesion, it can be inflated to occlude the AVM's feeder vessels and prevent the flow of blood. The embolization agent can be injected safely, while sparing the proximal arteries.^8,19 As the embolizing agent is injected into the balloon causing an increase in pressure, the leakage occurs distally into the AVM. The flow arrest caused by the balloon prevents the agent from traveling and embolizing into the lungs.

Following the embolization, the detachable balloon is secured with the embolizing agent, and the catheter is quickly withdrawn to detach, while the nondetachable catheter is deflated and withdrawn to prevent imprisonment within the lesion. ²⁰ The embolization of the lesion can be considered successful if the balloon is withdrawn and empty without evidence of the embolization particles at the tip, there is no evidence of the agent refluxing proximally, or if the removal of the balloon or catheter was deemed easy. ²⁰

In 1982, Debrun et al. compared the treatment of AVMs in three groups; group I consisted of 22 patients with AVMs embolized with a silastic calibrated-leak balloon, group II had 13 patients with AVMs treated with intraoperative embolization, and group III consisted of 11 patients with AVMs embolized with the latex calibrated-leak balloon. Of the 39 patients that underwent embolization, nine achieved complete embolization. The remaining 30 were partially embolized, 8 of whom underwent subsequent surgical resection, without evidence of delayed rebleeding. Of all patients treated, there was one death in the silastic balloon group. This study showed the efficacy of embolization, as well as the increase in success of surgical resection after a patient has undergone partial embolization. ²¹ Another case series by Vinuela et al. corroborated the safety and efficacy of the embolization of AVMs using the detachable calibrated-leak balloon system. ²²

Embolization can uncommonly result in neurological deficits, although this can vary based on the anatomy and severity of the AVM. These deficits are usually transient but can also be permanent. A study of 63 patients undergoing AVM embolization in 1991 reported 7 cases of hemorrhage secondary to treatment, with 2 patients dying and 1 patient left with a significant residual neurological deficit. ²³

Aneurysms

Early treatment of intracranial aneurysms involved acutely occluding the neck of an aneurysm, effectively removing it from circulation and preserving blood flow in the parent vessel. Using a latex detachable balloon catheter attached to a Teflon coaxial system, the balloon is positioned at the base of the aneurysm. The balloon is inflated, occluding the vessel and the patient is monitored. If tolerated, a second balloon is introduced under the first balloon to prevent it from becoming a distal embolus in the event that the first balloon detaches prematurely. Of a report of 14 carotid aneurysms treated using this technique, 2 patients died, 1 from aneurysm rupture and another from postoperative complications, and 2 patients experienced residual hemiplegia following the procedure. ¹⁴ Serbinenko also suggested the treatment of cerebral aneurysms by using two balloons. The first balloon was distal while the other balloon was proximal to the opening of the aneurysm, allowing for the injection of an embolizing agent through the proximal balloon's double-lumen catheter. ⁵ For balloon embolization of an intracranial aneurysm, the size and shape of the lesion must be determined. Interventional Therapeutics Corp. (South San Francisco, CA) developed a balloon that ranges from 0.85 × 44.10 to 1.80 × 7.60 mm uninflated, and 3.80 × 9.00 to 10.00 × 23.00 mm inflated.

The balloon was used in conjunction with a polyethylene catheter that can be steam-formed into different shapes based on the anatomy and lesion. ²⁴

The endovascular treatment of unclippable cerebral aneurysms using a No. 16 Debrun latex detachable balloon catheter for proximal artery occlusion was reported in 68 patients by Fox et al. in 1987. In this cohort, 37 patients had carotid artery aneurysms below the level of the ophthalmic artery, 21 aneurysms arose from the supraclinoid portion, 6 at the basilar artery trunk, and 1 distal vertebral artery aneurysm. Of the 68 patients with unclippable aneurysms, permanent occlusion was obtained in 65. All 37 patients with aneurysms below the level of the ophthalmic artery were found to have complete obliteration of the aneurysm. ²⁵ These results demonstrated that balloon occlusion of the proximal arteries was a safe and effective technique for the treatment of unclippable aneurysms but encountered a limitation due to inability of using the balloon occlusion technique in the supraclinoid carotid artery, distal vertebral artery, or higher segments due to the immense risk of occluding a perforating artery leading to major infarction. Another study by Romodanov et al. showed that the use of the balloon occlusion technique in patients that were postsubarachnoid hemorrhage (SAH) could lead to severe vasospasm and a mortality rate upwards of 22%. ²⁶

The use of detachable balloons to treat cerebral arterial aneurysms led to various issues. To start, the balloon cannot spontaneously enter an aneurysm, as it does with AV fistulas, which can lead to leaks when attempting to keep the balloon inflated. More importantly, since aneurysms are treated with intrasaccular balloons, inflating the balloon to the total aneurysmal volume is difficult, and poses a dangerously high risk of aneurysmal rupture. In 1990, a study by Higashida et al. reported a cohort of 84 patients who underwent percutaneous balloon embolization for the treatment of inoperable intracranial aneurysms. ²⁴ The results of this study revealed a myriad of complications directly related to the balloon embolization conducted in these patients. Notably, there were 15 deaths that were directly involved with the aneurysm treatment. Ten of these deaths were due to rupture secondary to incomplete occlusion of the aneurysm, leading to SAH, with 6 patients ultimately dying within 5 days of rupture. Other deaths were due to rupture of the balloon or valve leakage during polymerization, leading to the occlusion of distal vessels. Nine patients suffered a stroke directly related to complications encountered during treatment. Ultimately, this led to a morbidity rate of 11% and a mortality rate of 18%.

Postballoon era

The high complication rate of balloon embolization led investigators to pursue different methods for treating cerebral pathologies endovascularly. In 1989, Italian endovascular neurosurgeon Dr Guido Guglielmi introduced a groundbreaking study highlighting a promising alternative. Molded from ideas introduced throughout the decade, Guglielmi had developed detachable coils which could be delivered into an aneurysm atraumatically. ²⁷ Employing the basis of electrochemistry, Guglielmi was able to perform electrothrombosis by detaching a platinum coil from the delivery system and effectively occluding the aneurysm.

In 1990, Guglielmi used this technique on 15 patients with high-risk saccular aneurysms, leading to intra-aneurysmal thrombosis rates of 70% to 100% in all cases. ²⁸ The study reported no neurological complications after short-term follow up. Long-term follow up was limited by its recent development. This technique was rapidly adopted by the endovascular community and became the gold standard of treatment for intracranial aneurysms that were poor surgical candidates.^24,29

This new era for endovascular neurosurgery led to advancements in coil delivery, as well as large scale studies that further proved the safety and efficacy of coil embolization. The international subarachnoid aneurysm trial (ISAT) compared a large cohort of patients undergoing aneurysm clipping versus endovascular coiling, ultimately showing an absolute risk reduction of 7.4% (95% CI 3.6–11.2, P = 0.0001) with those who underwent endovascular treatment. ³⁰ The Barrow Ruptured Aneurysm Trial further established the safety of coil embolization, as well as the decreased follow-up complications. ³¹ As the years progressed, the ability to best treat cerebrovascular lesions in a patient-specific manner improved with advancements in neuroendovascular techniques and devices. Other techniques such as flow diversion and bioactive coils have been employed to aid in healing, which is expected to result in positive outcomes for patients in the long term.^32,33

Although the detachable balloon catheter technique has since been replaced by other techniques, balloons still hold a place in the treatment of certain cerebrovascular pathologies. The balloon is a versatile tool in the endovascular neurosurgeon's arsenal, allowing for augmentation with various other procedures. Despite its limited commercial availability, the detachable balloon can be used in vessel sacrifice, as well as AVM embolization, and embolization of traumatic CCFs. ³⁴ In Niu et al.'s study of 24 patients with traumatic CCFs, 2 underwent balloon embolization with 10 undergoing the double balloon technique. Of the patients that underwent balloon embolization, 81% were successfully treated on the first attempt, while the remaining patients were successfully treated on the second attempt. The detachable balloon, especially the double balloon technique, was shown to be safe and effective in the treatment of traumatic CCFs. ³⁵

Conclusion

Reports of the first detachable vascular balloon catheter can be traced back to the early 1960s. The detachable vascular balloon catheter enabled improvements in treatment of CCFs, vertebro-jugular fistulas, AVMs, and aneurysms. This technique would offer the first alternative to the conventional but unfavorable practice of carotid occlusion in CCF treatment. The balloon catheter would later be used in aneurysm occlusion and the subsequent calibrated-leak balloon catheter in selective angiography and embolization of AVMs. Although this technique has since been replaced by the detachable coils, bioactive devices, and flow diversion, this was a monumental stride in the history of NeuroIntervention and helped propel the specialty to the current era of patient-specific interventions.