Transradial access for pediatric teenage neurointervention: A single-center case series

Abstract

Transradial access is widely used in cardiological adult interventions and less in pediatrics. In recent years, this access has become more popular in the neuroradiological community in adult patients since it has fewer complications and is more comfortable for the patient after the procedure. We present a single-center case series of 52 transradial access neurointerventions (43 angiographies and 9 therapeutic procedures) in pediatric patients, with a failure of 4 cases (7.7%) in which we could not puncture the artery, crossing over to transfemoral access. Since in five cases we did angiography followed by therapeutic intervention, thus doing only one puncture access for both procedures, then our access failure rate was 10.6%. The 34 successful transradial access solely angiographies had a median radiation exposure of 887 mGy (interquartile range 628–1352), median fluoroscopy time of 9.5 min (interquartile range 7.5–15.3), and median procedure time of 28 min (interquartile range 24–33 min) Therapeutic procedure diagnosis were: one ruptured saccular aneurysm, two juvenile nasopharyngeal angiofibromas, and five arteriovenous malformations. The transradial access neurointerventions for pediatric population older than 11 years is safe and feasible, having previous experience in adults. Younger population should be considered on a case-to-case basis, depending on ultrasound measurement of the arterial diameter and the materials available.

Introduction

Transradial access (TRA) has been successfully used in cardiological interventions in adults. The first case series using this approach in neuroradiology was published in the year 2000. ¹ In the following years more case series have been published,^2–4 since then it has slowly been adopted becoming more popular recently. The first case series of TRA for coronary angiography was published in 1989. ⁵ Since then it has become widely adopted in the cardiological community, promoting and supporting a “radial first” approach in recent years. ⁶ Less vascular and bleeding complications, as well as patient comfort, are the major advantages over the transfemoral approach (TFA). ⁶ Nevertheless, there is a paucity of literature on pediatric cardiac and neuroradiological TRA interventions. We present a single-center case series of TRA in pediatric cerebral angiography and neurointerventions.

Material and method

We did a retrospective review of our prospectively filled database of neuroradiological cases managed at our hospital. Institutional Review Board and Regional Ethics Committee approval was obtained for the study. All TRA patients 18 years or younger between December 2012 and April 2021 were included. Demographic data, diagnosis, comorbidity, height, and weight were collected, as well as fluoroscopy time, radiation dose, and vessels catheterized. The procedure time was calculated from the recorded time of radial access until the last angiographic acquisition was done. The use of rotational three-dimensional (3D) was also recorded. Procedure complications were registered, with special characterization if they caused a neurological deficit. Statistical analysis was done with STATA 14.0 software. Considering the period of the study, we had an upgrade from a CCD camera image intensifier Siemens Axiom Artis FC monoplane angiography system to a flat panel image intensifier Philips Allura XPR FD20 monoplane.

Procedure

All operators had previous experience in TRA procedures in adults. Patients were under general anesthesia or with local anesthesia, and anesthesiological vigilance. The ulnar-palmar arch patency was evaluated using the Barbeau test. ⁷ The radial artery was palpated and punctured with a 20 gauge needle. If we failed to cannulate the radial artery then we crossed over to the femoral access. A 5 Fr radial introducer sheath (Radiofocus, Terumo) was inserted over a 0.021-inch guidewire. After verifying arterial blood reflux through the sheath, we injected intraarterial Verapamil 0.1 mg/kg up to a maximum of 5 mgr., and Heparin 70 I.U/kg, our standard “radial cocktail.” In the interventional cases, we loaded with 70 I.U/kg intravenous Heparin to double the basal activating clotting time (ACT) and controlled it during the procedure adding more Heparin as needed to keep this ACT target. In the angiography cases, we used a 5 Fr Simmons 2 hydrophilic diagnostic catheter (Terumo) over a 0.035-inch hydrophilic guidewire (Terumo) advanced under fluoroscopy. In the interventional cases, we used a 5 Fr or a 6 Fr radial introducer sheath. A 5 Fr Simmons 2 hydrophilic diagnostic catheter (Terumo) over a 260 cm hydrophilic guidewire (Terumo) was advanced to reach the desired vessel. Through an exchange maneuver, leaving the guidewire in place, we advanced the 5 or 6 Fr guide catheter under fluoroscopy to the designated vessel. After the procedure, it was not necessary to reverse the effect of Heparin, since the sheath was removed and TR-Band (Terumo) was left in place.

Results

In this period, 52 TRA pediatric procedures were done, of these 4 (7.7%) failed because we could not puncture the radial artery, crossing over to transfemoral access (TRF). If we consider that in five cases we did angiography followed by the therapeutic procedure in the same event, thus considering just one arterial puncture for both interventions (angiography and endovascular therapeutic intervention), we had a 10.6% access failure rate. No distal radial access was used. The mean age was 14.86 years (range 11–18 years), 36.5% were female and 63.5% were male. Mean height and weight were 165 cm (range 149–182) and 62.6 kg (range 42–100), respectively.

The five patients mentioned above are analyzed separately from the rest because we could not separate the radiation exposure dose and fluoroscopy time for each procedure, since the therapeutic intervention followed immediately the diagnostic angiography in the same event. The mean procedure time, mean fluoroscopy time, and mean radiation exposure correspond to 165 min (range 100–234), 45 min (range 24.1–68.1), and 3552 mGY (range 1492–5071), respectively. Diagnosis in this group was, two ruptured arteriovenous malformations (AVM) (Figure 1), one subarachnoid hemorrhage secondary to a carotid bifurcation ruptured saccular aneurysm (Figure 2), and two juvenile nasopharyngeal angiofibroma. Resume of the data listed in Table 1. In one of these cases, the patient presented with a ruptured left temporal-occipital AVM. We did a partial embolization, occluding the posterior circulation feeding arteries. When the patient recovered from anesthesia he presented with a right brachial motor deficit. Brain MRI showed no restriction on diffusion-weighted imaging and no signs of new bleeding. Buy ∼1 h he had a full recovery. Since he had not been on anticonvulsive therapy, and the imaging studies disclosed no new lesions, the event was interpreted as a focal seizure.

Figure 1.

(A) Cathether coming from the right subclavian artery reaching the left internal carotid artery (black arrow) in a patient with a temporal-insular arteriovenous malformations (AVM). (B) Same patient showing left temporo-insular AVM nidus with intranidal aneurysm pre-treatment and post-glue embolization (C).

Figure 2.

Unsubtracted antero-posterior image of catheter coming from right subclavian artery (black arrow) and pack of embolization coils (white arrow) of the left carotid bifurcation ruptured aneurysm. (B) Anteroposterior pre- and (C) post-embolization, subtracted angiography of ruptured left carotid bifurcation aneurysm (black arrow).

Table 1.

Summary of demographic patient characteristics and procedural data for pediatric transradial procedures.

Variable	Result
Age (years)	Mean 14.86; range 11–18
Sex	36.5% female 63.5% male
Weight (kg)	Mean 62.6; range 42–100
Height (cm)	Mean 165; range 149–182
Procedures	Diagnostic angiography = 39 Therapeutic interventions = 9 AVM 6 Intracranial aneurysm 1 JNA 2

AVM: arteriovenous malformations; JNA: juvenile nasopharyngeal angiofibroma.

Four interventional procedures had the diagnostic angiography done previously. All of these were ruptured AVM, their mean procedure time was 162 min (range 124–206), mean fluoroscopy time was 57 min (range 25–70), and mean radiation exposure was 7104 mGy.

There were 34 successful TRA solely diagnostic angiographies done in 30 patients. A total of six 3D rotational angiographies were done (range 0–2). The median radiation exposure was 887 mGy (interquartile range (IQR) 628–1352). The median fluoroscopy time was 9.5 min (IQR 7.5–15.3). The median procedure time was 28 min (IQR 24–33 min) with a mean time of 4.5 min/vessel (range 1.85–8.4). No puncture site complications, neurological deficit, or radial artery spasm were encountered. Selective injections involved the following arteries: right common carotid artery (CCA) (n = 33), left CCA (n = 31), right internal carotid artery (ICA) (n = 26), left ICA (n = 25), right external carotid artery (ECA) (n = 23), left ECA (n = 22), right vertebral artery (VA) (n = 24), left VA (n = 26), right subclavian artery (SCA) (n = 0), left SCA (n = 0), and super-selective injection (n = 4). Summarized data are listed in Table 2.

Table 2.

Procedural data for only diagnostic pediatric transradial angiographies.

Procedural time (min.)	Median 28; IQR 24–33
Fluoroscopy time (min.)	Median 9.5; IQR 7.5–15.3
Radiation exposure (mGy)	887; IQR 628–1352
Time per vessel (min)	Mean 4.5; range 1.85–8.4
Complications	None

Discussion

The TRA is a safe route with important advantages over the TFA, having fewer complications as demonstrated in cardiology. ⁸ The access point is easy to visualize for after-procedure monitoring. The patient can move freely without the risk of bleeding since you can easily use a patent hemostasis compression device that stays in place for the closure site. This last point is a big advantage in pediatric patients since otherwise, you would need to keep them sedated and/or immobilized. Another advantage is that Heparin does not need to be reversed when a therapeutic intervention is done.

In the cardiology community, the TRA has long been used in adults, but there is scarce literature on pediatric patients ⁹ being the first case series in 2009. ¹⁰ In neuroradiology, even though the first case series were published more than fifteen years ago, it has slowly been incorporated into regular practice for adult interventions. The first pediatric neurointervention multi-institutional case series was published in 2020. ¹¹ This series showed that radial access under ultrasound guidance in the pediatric population is safe and feasible, crossing over to TFA in 8.2% of the cases because of vasospasm. Up to our knowledge, we present the largest single-center pediatric case series, having a similar cross over to TFA of 7.7%, though in our case we failed to catheterize the artery thus having an access failure rate of 10.6%. This higher failure rate is explained since at our institution we do not use ultrasound guidance as a standard of practice for vascular access in cardiological or neurointerventional procedures. We did not encounter local vasospasm. The standard use of the “radial cocktail” in our center for all TRA cases could be the explanation of the absence of local vasospasm in our series.

The difference of radiation dose between the angiography plus therapeutic intervention in the same event versus the solely therapeutic intervention group might be explained by the diagnosis encountered in this last group, all of these patients had AVM. This pathology requires a more laborious intervention with longer fluoroscopy time, and more angiographic runs, thus with more radiation exposure. At the same time, we must consider the different technology of the angiography equipment passing from a CCD camera image intensifier to a flat panel detector, having a considerable radiation dose reduction with a good image quality the latter. ¹²

The major fear for the TRA in the pediatric population is the size of the artery. This concern was approached recently in a prospective study that measured the diameter of radial arteries in children mean age 8.9 ( + /−) 5.8 years (range, 29 days to 18 years), finding no statistical difference between females and males, and that children older than 12 years approached adult size diameter. ¹³

Once you have catheterized the radial artery the supra-aortic vessel access is rather straightforward unless you encounter an anatomical variation, thus pediatric therapeutic interventions can also be done through this access as shown in previous publications^11,14 as well as in our series.

The TRA for the pediatric population is safe, it presents a rather low complication ¹⁵ and failure rate, that may be enhanced with the use of ultrasound guidance for artery access ¹⁶ and antispasmodic “radial cocktail” or other interventions before puncture such as local Nitroglycerin.^17–20 A “radial first” approach should be considered in the pediatric population once you have acquired experience in adults.