Abstract
Background
Transradial coronary angiography/intervention (TRA/TRI) is associated with reduced rates of bleeding, vascular complications, and major adverse cardiovascular events as compared to the transfemoral approach, but remains underutilized in the United States (U.S.). Small radial caliber is often cited as a technical impediment, however radial artery diameter (RAD) has not yet been systematically studied in the U.S. population using routine, prospective radiobrachial angiography.
Methods
Consecutive patients (pts) with radiobrachial angiography acquired during TRA/TRI from September 2015 to August 2016 were retrospectively analyzed. Quantitative angiography (QA) was performed on digital subtraction angiograms. RAD measurements at distal (dRAD), mid (mRAD), and proximal (pRAD) segments, as well as minimum (minRAD) and maximum (maxRAD) diameters were indexed to radial arterial sheath size and tabulated. RAD measurements were adjudicated by 2 expert operators. Descriptive statistics and regression analyses were performed using STATA (College Station, TX).
Results
Of 175 radiobrachial angiograms, 2 were excluded due to uninterpretable QA. Woman had smaller RAD versus men: pRAD (3.11 vs 3.33 mm, p = 0.021), minRAD (2.36 vs 2.59 mm, p = 0.006), and maxRAD (3.32 vs 3.53 mm, p = 0.0195). Univariate analysis showed correlation between minRAD and gender ( p = 0.012), age ( p = 0.019), and weight ( p = 0.008). However, after multivariate analysis, only gender was associated with minRAD ( p = 0.05).
Conclusion
This is the first study to describe the clinical determinants of RAD using prospective post-vasodilator, radiobrachial angiography in a U.S. population. Women had significantly smaller RAD across proximal, minimum, and maximum segments. Sex was the only multivariate predictor of minRAD.
Highlights
- •
Radial artery diameter has not yet been systematically studied in a United States population.
- •
Women had smaller proximal, maximal, and minimal radial artery diameters than men.
- •
In a multivariate analysis, sex was significantly different with respect to minimum radial artery diameter
1
Introduction
Over the past 30 years, percutaneous coronary intervention (PCI) has grown in complexity and technical sophistication, incorporating the routine use of lesion modification tools such as cutting/scoring balloons and atherectomy devices and utilizing complex, multi-stent strategies. Early versions of these therapeutic devices often necessitated the use of larger sheaths and guide catheters which were effectively beyond the range of sizes accommodated by most patients’ radial arteries. Interestingly, however, although therapeutic coronary devices have undergone steady, progressive miniaturization over the past one and a half decades, with most modern devices now compatible with 0.071 in. inner-diameter, 6 French guide catheters, many operators in the United States (U.S.) continue to cite the inability to use equipment large enough to perform complex PCI as a reason to eschew the transradial approach [ ].
Small radial artery (RA) caliber is often cited as a technical impediment, however radial artery diameter (RAD) has not yet been systematically studied in the U.S. population using mandatory (as opposed to provisional), prospective, radiobrachial angiography. Several prior retrospective studies have determined RA caliber in Japanese and Southeast Asian patients using noninvasive vascular ultrasonography, however, little data exist to address RAD in the U.S. population, which is presumably more heterogeneous than the aforementioned study groups with respect to various relevant parameters such as height, weight, body mass index (BMI), and ethnicity. Furthermore, to our knowledge, RAD has not yet been measured using a real-time, in vivo approach via radiobrachial angiography, thus adding to the novelty of this study.
1.1
Study aim
We sought to assess the distribution of RA caliber in a contemporary population of U.S. patients undergoing coronary angiography and/or intervention, using routine, prospective radiobrachial angiography.
2
Methods
This single-center, observational study sought to assess various RA characteristics in a heterogeneous population of U.S. patients via the use of routine, prospective radiobrachial angiography. Between September 2015 to August 2016, 175 consecutive adult patients who underwent transradial coronary angiography and/or intervention at a single, large academic medical center were identified from a database of vascular access procedures performed in the cardiac catheterization laboratory. Patients were eligible for inclusion in this study if they underwent conventional (proximal) transradial catheterization with digital subtraction angiography (DSA) of the radiobrachial vasculature performed at the beginning of the procedure (per the preference of the operator), following sheath insertion and administration of spasmolytics, and before any wires or catheters were introduced into the body. Accordingly, patients were excluded if they did not or could not receive vasodilators (due to hypotension, etc.) or if radiobrachial angiography was performed on a provisional basis (i.e. in response to difficulty with catheter manipulation, inability to navigate a guidewire into the central circulation, etc.) or if interpretable images inclusive of the tip of the radial sheath were not obtained. Patients with known vascular anomalies, prior failed radial procedures or distal radial (“anatomic snuffbox”) access were also excluded from this study.
The electronic medical record was reviewed for pertinent demographic, clinical, and procedural information. Operative reports, radiobrachial angiograms and coronary angiograms were reviewed. Information was stored in a secure electronic database.
2.1
Transradial access
Two high-volume transradial interventional operators at our institution performed the majority of cardiac catheterizations included in this study. Decisions relating to technical aspects of radial access, such as patient selection, left versus right radial approach, use of ultrasound guidance for radial puncture, choice of access technique, micropuncture access, administration of tumescent anesthesia, etc., were left to the discretion of the interventional operator. Conscious sedation was routinely administered prior to arterial access with intravenous fentanyl and/or midazolam to ensure patient comfort and reduce incidence of radial vasospasm. After 2% lidocaine was injected subcutaneously, access was usually obtained with either a 20-gauge angiocath or 21-gauge, 4 cm micropuncture needle, approximately 2–3 cm proximal to the styloid process, at the point of maximal pulsation. Hydrophilic Terumo Glidesheaths (Terumo Interventional Systems, Somerset, NJ) were used in all cases, the majority of which were 6 French standard sheaths, and a minority of which were Glidesheath 6/5 French Slender sheaths. The choice of sheath was left to operator discretion.
After the RA was accessed and the sheath was secured in place, a spasmolytic/anticoagulant drug “cocktail” was diluted with aspirated blood and administered via the sidearm of the sheath. The cocktail typically consisted of 50 units/kg bodyweight of unfractionated heparin and a minimum of 200 μg of nitroglycerin ± 2.5 mg verapamil (as permitted by heart rate, blood pressure and systolic function). Immediately after administration of the aforementioned medications, a 3 frame-per-second, DSA of the radiobrachial vasculature was obtained with a portion of the inserted sheath visible in the image (as this was required for calibration prior to measurement of quantitative images). Cardiac catheterization and coronary intervention (if indicated), were then performed per standard of care.
2.2
Quantitative radial angiography
Integrated quantitative angiography (QA) software (GE Centricity Cardiology CA1000 2.0, GE Healthcare, Milwaukee, WI) was utilized to make offline RAD measurements. Assessments were performed by two trained reviewers, independent from the interventional operators, and subsequently adjudicated in a blinded fashion by two expert radial operators to ensure quality and reproducibility.
The still frame from the radiobrachial angiogram that demonstrated maximal arterial filling was used for QA calibration and interpretation. The still images were magnified to twice their original size for optimal vessel border detection and tracing. The outer borders of the radial sheath were identified and point-to-point calibration was performed using manufacturer-provided specifications of the radial sheath diameter. For example, the outer diameter of a 6 French Terumo Glidesheath (Terumo Interventional Systems, Somerset, NJ) as reported by Terumo is 2.62 mm, therefore the distance between the lateral and medial outer borders of the arterial sheath was calibrated to 2.62 mm using point-to-point edge detection. Once the system was appropriately calibrated, the RAD could then be determined using the automatic border detection function.
The RAD was measured at several points along the course of the vessel, beginning at the distal-most point (dRAD) immediately proximal to the visible tip of the sheath and proceeding to the proximal origin of the RA from the brachial artery, typically seen in the antecubital fossa. The proximal radial artery (pRAD) segment was measured at a point immediately distal to the beginning of the brachial artery, and the mid segment of the radial artery (mRAD) was measured midway between the dRAD point and the pRAD point. In addition, along the course of the vessel, minimum radial artery diameter (minRAD) and maximum radial artery diameter (maxRAD) were measured.
2.3
Statistical analysis
Comparisons between study indications and clinical variables were performed using an unpaired Student’s t -test for continuous variables with a level of significance of p < 0.05. Categorical variables were compared using Chi-square and Fisher’s exact tests. Univariate predictors of minRAD were entered into a multivariate regression model and analyzed with STATA (College Station, TX). A p -value of <0.05 was considered statistically significant. Cumulative distribution frequency curves were plotted using Microsoft Excel (Redmond, WA).
2
Methods
This single-center, observational study sought to assess various RA characteristics in a heterogeneous population of U.S. patients via the use of routine, prospective radiobrachial angiography. Between September 2015 to August 2016, 175 consecutive adult patients who underwent transradial coronary angiography and/or intervention at a single, large academic medical center were identified from a database of vascular access procedures performed in the cardiac catheterization laboratory. Patients were eligible for inclusion in this study if they underwent conventional (proximal) transradial catheterization with digital subtraction angiography (DSA) of the radiobrachial vasculature performed at the beginning of the procedure (per the preference of the operator), following sheath insertion and administration of spasmolytics, and before any wires or catheters were introduced into the body. Accordingly, patients were excluded if they did not or could not receive vasodilators (due to hypotension, etc.) or if radiobrachial angiography was performed on a provisional basis (i.e. in response to difficulty with catheter manipulation, inability to navigate a guidewire into the central circulation, etc.) or if interpretable images inclusive of the tip of the radial sheath were not obtained. Patients with known vascular anomalies, prior failed radial procedures or distal radial (“anatomic snuffbox”) access were also excluded from this study.
The electronic medical record was reviewed for pertinent demographic, clinical, and procedural information. Operative reports, radiobrachial angiograms and coronary angiograms were reviewed. Information was stored in a secure electronic database.
2.1
Transradial access
Two high-volume transradial interventional operators at our institution performed the majority of cardiac catheterizations included in this study. Decisions relating to technical aspects of radial access, such as patient selection, left versus right radial approach, use of ultrasound guidance for radial puncture, choice of access technique, micropuncture access, administration of tumescent anesthesia, etc., were left to the discretion of the interventional operator. Conscious sedation was routinely administered prior to arterial access with intravenous fentanyl and/or midazolam to ensure patient comfort and reduce incidence of radial vasospasm. After 2% lidocaine was injected subcutaneously, access was usually obtained with either a 20-gauge angiocath or 21-gauge, 4 cm micropuncture needle, approximately 2–3 cm proximal to the styloid process, at the point of maximal pulsation. Hydrophilic Terumo Glidesheaths (Terumo Interventional Systems, Somerset, NJ) were used in all cases, the majority of which were 6 French standard sheaths, and a minority of which were Glidesheath 6/5 French Slender sheaths. The choice of sheath was left to operator discretion.
After the RA was accessed and the sheath was secured in place, a spasmolytic/anticoagulant drug “cocktail” was diluted with aspirated blood and administered via the sidearm of the sheath. The cocktail typically consisted of 50 units/kg bodyweight of unfractionated heparin and a minimum of 200 μg of nitroglycerin ± 2.5 mg verapamil (as permitted by heart rate, blood pressure and systolic function). Immediately after administration of the aforementioned medications, a 3 frame-per-second, DSA of the radiobrachial vasculature was obtained with a portion of the inserted sheath visible in the image (as this was required for calibration prior to measurement of quantitative images). Cardiac catheterization and coronary intervention (if indicated), were then performed per standard of care.
2.2
Quantitative radial angiography
Integrated quantitative angiography (QA) software (GE Centricity Cardiology CA1000 2.0, GE Healthcare, Milwaukee, WI) was utilized to make offline RAD measurements. Assessments were performed by two trained reviewers, independent from the interventional operators, and subsequently adjudicated in a blinded fashion by two expert radial operators to ensure quality and reproducibility.
The still frame from the radiobrachial angiogram that demonstrated maximal arterial filling was used for QA calibration and interpretation. The still images were magnified to twice their original size for optimal vessel border detection and tracing. The outer borders of the radial sheath were identified and point-to-point calibration was performed using manufacturer-provided specifications of the radial sheath diameter. For example, the outer diameter of a 6 French Terumo Glidesheath (Terumo Interventional Systems, Somerset, NJ) as reported by Terumo is 2.62 mm, therefore the distance between the lateral and medial outer borders of the arterial sheath was calibrated to 2.62 mm using point-to-point edge detection. Once the system was appropriately calibrated, the RAD could then be determined using the automatic border detection function.
The RAD was measured at several points along the course of the vessel, beginning at the distal-most point (dRAD) immediately proximal to the visible tip of the sheath and proceeding to the proximal origin of the RA from the brachial artery, typically seen in the antecubital fossa. The proximal radial artery (pRAD) segment was measured at a point immediately distal to the beginning of the brachial artery, and the mid segment of the radial artery (mRAD) was measured midway between the dRAD point and the pRAD point. In addition, along the course of the vessel, minimum radial artery diameter (minRAD) and maximum radial artery diameter (maxRAD) were measured.
2.3
Statistical analysis
Comparisons between study indications and clinical variables were performed using an unpaired Student’s t -test for continuous variables with a level of significance of p < 0.05. Categorical variables were compared using Chi-square and Fisher’s exact tests. Univariate predictors of minRAD were entered into a multivariate regression model and analyzed with STATA (College Station, TX). A p -value of <0.05 was considered statistically significant. Cumulative distribution frequency curves were plotted using Microsoft Excel (Redmond, WA).
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
