Usefulness of hydrophilic coating on arterial sheath introducer in transradial coronary intervention

Radial Artery Spasm-A Review on Incidence, Prevention and Treatment

Radial artery spasm (RAS) is a common complication associated with transradial access (TRA) for coronary interventions, particularly affecting elderly patients in whom radial access is preferred due to its benefits in reducing bleeding complications, improving clinical outcomes, and lowering long-term costs. This review examines the incidence, prevention, and treatment of RAS. Methods included an online search of PubMed and other databases in early 2024, analyzing meta-analyses, reviews, studies, and case reports. RAS is characterized by a sudden narrowing of the radial artery due to psychological and mechanical factors with incidence reports varying up to 51.3%. Key risk factors include patient characteristics like female sex, age, and small body size as well as procedural factors such as emergency procedures and the use of multiple catheters. Preventive measures include using distal radial access, hydrophilic sheaths, and appropriate catheter sizes. Treatments involve the intraarterial administration of nitroglycerine and verapamil as well as mechanical methods like balloon-assisted tracking. This review underscores the need for standardizing RAS definitions and emphasizes the importance of operator experience and patient management in reducing RAS incidence and improving procedural success.

Radial artery occlusion after aneurysm treatment using the rist guide catheter: Single center cohort study

BACKGROUND AND PURPOSE

Delayed radial artery occlusion (dRAO) is a frequent complication after transradial access (TRA) for neurointervention when using standard large guide catheters. The RIST 079 guide catheter (RIST GC) is the first catheter designed for TRA in neurointervention. We aimed to assess the rate of dRAO after intracranial aneurysm (IA) treatment using the RIST GC.

METHODS

Patients treated for an IA using TRA and the RIST GC between June 2021 and November 2022 were referred to a systematic US-doppler assessment of the radial artery patency at 3-month follow-up. Patients with and without dRAO were compared to identify risk factors.

RESULTS

Twenty-two patients were included in the analysis. At 3-months follow up, 6 patients (27.3 %) presented with dRAO. Four patients were asymptomatic and 2 experienced post-operative radial hematoma and wrist pain. There was a tendency towards younger age, longer procedure duration and higher rate of forearm hematoma in patients with dRAO. Navigation using the RIST GC was successful in 90.9 % of cases. Intracranial access failures and navigation complications were all related to left internal carotid artery navigation.

CONCLUSIONS

At 3-month follow up, 27.3 % of patients treated for IA using TRA with the RIST GC presented dRAO.

Use of the Sheathless Eaucath Is an Effective Strategy to Overcome Resistant Severe Radial Spasm

Objectives

We aimed to assess the effectiveness of the sheathless Eaucath guiding catheter (SEGC) in overcoming severe spasm.

Background

Radial spasm is a frequent challenge in transradial access (TRA) and can be difficult to manage.

Methods

We performed a prospective observational study of 1000 consecutive patients undergoing coronary angiography with or without percutaneous coronary intervention. Patients with primary transfemoral access (TFA) or primary use of a sheathless guide catheter were excluded. Patients who developed angiographically confirmed severe spasm were treated with further sedation and vasodilators. If the conventional catheter would still not advance, it was exchanged for a SEGC. The primary endpoint was the successful passage of the SEGC through the radial with successful engagement of the coronary artery in patients with resistant severe spasm.

Results

Primary TFA access was used in 58 (5.8%) and primary radial access with a SEGC in 44 (4.4%) patients. Of the remaining 898 patients, 888 (98.9%) had a radial sheath successfully inserted. Of these, 49 (5.5%) developed severe radial spasm with inability to advance the catheter. Following treatment with additional sedation and vasodilators, the severe spasm resolved in 5 (10.2%) patients. Passage of a SEGC was attempted in the remaining 44 patients with resistant severe spasm. Passage of the SEGC and engagement of coronary arteries were successful in all cases. There were no complications related to use of the SEGC.

Conclusions

Our findings suggest that use of the SEGC for resistant severe spasm is highly effective, safe, and may reduce the need for conversion to TFA.

Risk Assessment and Regulatory Exploration of the Lubrication Coating on Intravascular Medical Devices

Lubricious polymer coatings are increasingly used on intravascular devices to facilitate application processes. Although increasing reports about the detachment and subsequent embolism of polymer particles, this iatrogenic polymer embolism has not been paid enough clinical attention for many years. This article reviews the hazard of coating separation and the difficulty to find it. Furthermore, this proposes the scientific evaluation concept and regulatory exploration to solve the problems.

Foreign body reaction toward hydrophilic polymer at the site of endovascular procedure: A report of two cases

Hydrophilic polymer-coated devices have been increasingly utilized for various endovascular procedures, however not been without adverse effects. We report two cases of subacute cutaneous lesions on the neck encountered in our dermatology clinic. Histopathologic findings were significant for a nodular aggregate of epithelioid histiocytes and lymphocytes with numerous foreign body giant cells in the dermis. The granulomatous infiltrate was associated with an amorphous basophilic non-polarizable material. Further chart review reveals both patients receiving a central venous procedure in the past, thus attributing the hydrophilic polymers as the likely source of the foreign material found at the insertion site. Our cases contrast to the more commonly reported distal embolization by these hydrophilic polymer layers. We suspect the incidence of retained hydrophilic polymer at the site of prior endovascular procedures may be underreported in the literature with the more inconspicuous presentations. Therefore, retained foreign material should be considered by both treating physicians and dermatopathologists in presenting cases of lesions that occur at common sites of endovascular procedures.

Radial artery spasm: reviews and updates

Elective and emergent coronary interventions via transradial access (TRA) are been used increasingly as they carry a reduced risk of complications. Percutaneous coronary intervention via TRA may lead to radial artery spasms (RAS) that may result in prolonged procedure time, cross-over of access site, and other complications. This review article discusses the recent definitions, incidences, pathophysiology, predictive score calculator, efficacy, the safety of the radial cocktails, and treatment of the RAS.

Comparison of optical microscopy and optical coherence tomography as quality assurance methods for evaluating lubricious hydrophilic coatings surrounding catheter shafts

Cardiac catheters are a vital tool in medicine due to their widespread use in many minimally invasive procedures. To aid in advancing the catheter within the patient's vasculature, many catheters are coated with a lubricious hydrophilic coating (HPC). Although HPCs benefit patients, their delamination during use is a serious safety concern. Adverse health effects associated with HPC delamination include pulmonary and myocardial embolism, embolic stroke, infarction, and death. In order to improve patient outcomes, more consistent manufacturing methods and improved quality assurance techniques are needed to evaluate HPC medical devices. The present work investigates the efficacy of two novel methods to image and evaluate HPCs post-manufacturing, relative to industry-standard scanning electron microscopy (SEM)-based methods. We have shown that novel evaluation approaches based on optical microscopy (OM) and optical coherence tomography (OCT) are capable of imaging HPC layers and quantifying HPC thickness, saving hours of time relative to SEM sample preparation and imaging. Additionally, the nondestructive nature of OCT avoids damage and alteration to the HPC prior to imaging, leading to more reliable HPC thickness measurements. Overall, the work demonstrated the feasibility and advantages of using OM and OCT to image and measure HPC thickness relative to industry-standard SEM methods.

Analysis: Intravascular Devices with a Higher Risk of Polymer Emboli: The Need for Particulate Generation Testing

Hydrophilic polymer coatings on intravascular devices lower friction between the device and vasculature, thereby reducing trauma during interventional procedures. Polymer coating embolism-the detachment and downstream embolism of polymer particles-has been reported as an iatrogenic complication of coated interventional devices affecting the vasculature and various organs. The Food and Drug Administration (FDA) acknowledges this complication and continues to work with stakeholders to close gaps in performance testing and standards related to polymer coating integrity. Recent innovations within interventional technologies have led to development of new hydrophilic-coated devices with expanded indications for use. The 2018 FDA draft guidance for intravascular guidewires expands the application of particulate generation testing to most devices and recommends labeling changes to increase industry awareness. This article highlights current procedural trends where the phenomenon of polymer coating embolism may be more prevalent. It describes the mechanisms of polymer separation, reported clinical sequelae, and risk factors for relevant indications. These procedural trends and associated risk factors articulate the need for particulate testing and support the FDA's draft guidance recommendations for performance testing of applied coatings. If standardized, particulate assessments may allow characterization and comparisons of coating integrity among devices from various manufacturers, and are an important foundation for setting particulate limits. As hydrophilic coatings enable endovascular treatment for a range of patient populations, setting particulate limits or finding alternative solutions without compromise to device function may be essential. Particulate testing is relevant to physicians, regulators, and manufacturers for the purposes of product development and quality improvement of interventional devices.

Analysis: Particulate Limits for Intravascular Devices: Considerations for Polymer Coating Embolism

Lubricious polymer coatings are increasingly used on intravascular devices to facilitate easier access and navigation through tortuous blood vessels. Recent reports highlight the separation and downstream embolism of polymer particles affecting the vasculature and various organs. The Food and Drug Administration (FDA) acknowledges polymer coating embolism as an iatrogenic complication of intravascular devices and continues to close gaps in standards related to coating integrity. The Association for the Advancement of Medical Instrumentation established particulate testing as an industry standard for evaluating coating integrity of intravascular devices. The FDA recognizes this standard; however, challenges exist in setting particulate limits that may compromise device function without sufficient clinical data. The microscopic nature of polymer emboli not visible with available imaging modalities has impacted reporting. This has also resulted in a reduced number of manufacturer-driven product development projects related to coating integrity. On the other hand, recent procedural trends have supported the innovation of coated devices with expanded indications, requiring particulate evaluations and release limits. This article proposes a methodology to set particulate limits for intravascular devices given existing clinical, regulatory, and manufacturing challenges. The approach with standardization requirements enables characterization, comparison, and evaluation of lubricious coatings from various manufacturers. It incorporates a step-by-step procedure that adds scrutiny to the application of coatings while ensuring device function is not impacted. Together with particulate assessments, clinicopathologic and animal studies permit an understanding of particulate ranges from commercially available devices and setting of particulate limits for new device evaluations.

Comparison of Radial Artery Occlusion Following Transradial Access for Percutaneous Coronary Intervention Using Sheath-based versus Sheathless Technique

We compared the risk of radial artery occlusion (RAO) in patients undergoing coronary intervention with introducer sheath (SG) or without introducer sheath (SLG). 1251 consecutive patients, from 2 tertiary care center in Pennsylvania, USA, undergoing percutaneous coronary interventions (PCI) between 2008-2013 formed the study cohort (SLG: 161 patients, SG: 1090 patients). Radial artery patency was assessed using plethysmography. The association between sheath use and RAO was assessed using unadjusted, adjusted and propensity macthed logistic regression analyses. Mean age: 65 years, men: 63%, diabetics: 37%. SG was associated with lower RAO at band removal [unadjusted (OR: 0.31, 95% CI: 0.21-0.46), adjusted (OR: 0.10, 95% CI: 0.05-0.20) and propensity matched (OR: 0.20, 95% CI: 0.13-0.32)], at 24 hours [unadjusted (OR: 0.20, 95% CI: 0.12-0.34), adjusted (OR: 0.12, 95% CI: 0.06-0.24) and propensity matched (OR: 0.13, 95% CI: 0.07-0.25)] and 30 days [unadjusted (OR: 0.28, 95% CI: 0.14-0.54), adjusted (OR: 0.22, 95% CI: 0.10-0.50) and propensity matched (OR: 0.18, 95% CI: 0.10-0.40)], compared to SLG. Sheath use during radial access for PCI is associated with less RAO. It is unclear if use of introducer sheath during radial access for PCI reduces incidence of RAO. In this prospective cohort study involving 1251 concecutive patients undergoing PCI via radial access between 2008-2013, we assessed the difference in incidence of RAO between the SG (n = 1090) and the SLG (n = 161 patients) groups. SG group experienced lower incidence of RAO at band removal, 24 hours and 30 days post PCI in the unadjusted, adjusted, and propensity matched analyses compared to the SLG group. In conclusion sheath use during radial access for PCI is associated with less RAO.

Procedural sedation during transradial coronary angiography to prevent spasm

AIM

Radial artery spasm is common during transradial procedures and is the most common cause of procedural failure. The objectives of this study were to assess whether the routine administration of sedation at the beginning of transradial coronary angiography with the use of hydrophilic-coated and smaller sheaths/catheters would reduce the incidence of radial artery spasm.

PATIENTS AND METHODS

Patients undergoing transradial coronary angiography were prospectively randomized to receive midazolam during the procedure or no sedative treatment. The primary endpoint was angiographically confirmed radial artery spasm. Stenosis of the radial artery was measured with a computer-assisted quantification method.

RESULTS

In all, 150 patients were randomized into a treatment group and a control group. Spasm occurred in 15 patients of the treatment group (20 %) versus 16 in the control group (21.3 %). There were no differences between the two groups regarding the incidence of spasm and the distribution of spasm severity (p > 0.05). No significant differences were observed between the two groups in terms of 30-day mortality or repeat hospitalization for any cause (p > 0.05).

CONCLUSION

Routine use of midazolam could not reduce the occurrence of radial artery spasm during transradial coronary angiography.

Radial Artery Access, Hemostasis, and Radial Artery Occlusion

Radial artery access is usually achieved using a micropuncture system. Hydrophilic introducers are used to improve comfort, probably by reducing spasm. A vasodilator cocktail should be administered to prevent severe spasm and anticoagulation; usually, unfractionated heparin is administered to prevent subsequent radial artery occlusion (RAO). Hemostasis at the radial artery puncture site is easily achievable by local compression. Application of local compression frequently leads to interruption of radial artery flow and subsequent occlusion. Careful attention to maintenance of radial artery patency during hemostatic compression has been shown to decrease the risk of RAO without increasing access-related bleeding complications.

Cardiac catheterization: consequences for the endothelium and potential for nanomedicine

Cardiac catheterization results in interactions between the catheter and surfaces and the artery lumen, which is lined by the endothelium. These interactions can range from minor rubbing to severe mechanical injury. Further, in the case of radial access, even atraumatic interactions have consequences ranging from clinical complications, such as radial spasm and radial occlusion, to lasting endothelial cell dysfunction. These consequences may be underappreciated; however, endothelial cells play a central role in maintaining vascular homeostasis via nitric oxide production. Existing treatment paradigms do not address endothelial dysfunction or damage and, thus, novel therapeutic approaches are needed. Nanomedicine, in particular, offers great potential in the form of targeted drug delivery, via functionalized coatings or nanocarriers, aimed at increased nitric oxide bioavailability or reduced inflammation.

Complete "in situ" avulsion of the radial artery complicating transradial coronary rotational atherectomy

BACKGROUND

Transradial percutaneous access (TR) is promoted because of increased patient comfort and convenience as well as a lower risk of access site and cardiac complications in the literature. Increased use of the TR purports a new set of possible complications for which the vascular surgeon must be capable to recognize and manage.

METHODS

A 48-year-old, devout Jehovah's Witness, woman with a history of coronary artery bypass surgery presented with a non-ST-segment elevation acute myocardial infarction. Pretransfer catheterization demonstrated a heavily calcified, 90% distal left main stenosis with an occluded left internal mammary artery graft to the left anterior descending coronary artery. To minimize the risk of bleeding requiring a blood transfusion, a coronary rotational atherectomy via a TR was performed. A nonhydrophilic, 7F sheath was used to accommodate the larger rotational atherectomy burr sizes. The coronary procedure was successful, but the sheath removal was complicated by significant resistance to pullback while the patient complained of severe pain. Post procedure she developed a hematoma with motor and neurological deficits of her hand.

RESULTS

Emergent surgical exploration with fasciotomy was planned. The radial artery was explored and found to be redundant and pulseless, prompting proximal evaluation and revealing complete avulsion of the radial artery at its origin. An intraoperative arteriogram revealed that the brachial and ulnar arteries and interosseous branches were patent and filled the palmar arch and surgical ligation of the radial artery was conducted.

CONCLUSION

Vascular surgeons need to be aware of potential complications related to TR which are likely to increase as this method is more widely disseminated.

Impact of length and hydrophilic coating of the introducer sheath on radial artery spasm during transradial coronary intervention: a randomized study

OBJECTIVES

The aim of this study was to assess the impact of length and hydrophilic coating of the introducer sheath on radial artery spasm, radial artery occlusion, and local vascular complications in patients undergoing transradial coronary procedures.

BACKGROUND

Radial artery spasm is common during transradial procedures and the most common cause for procedural failure.

METHODS

We randomly assigned, in a factorial design, 790 patients scheduled for a transradial coronary procedure to long (23-cm) or short (13-cm) and hydrophilic-coated or uncoated introducer sheaths. The primary outcome measure was clinical evidence of radial artery spasm, and secondary outcome measures were patient discomfort and local vascular complications.

RESULTS

Procedural success was achieved in 96% of the cases, and radial artery spasm accounted for 17 of 33 failed cases. There was significantly less radial artery spasm (19.0% vs. 39.9%, odds ratio [OR]: 2.87; 95% confidence interval [CI]: 2.07 to 3.97, p < 0.001) and patient reported discomfort (15.1% vs. 28.5%, OR: 2.27; 95% CI: 1.59 to 3.23, p < 0.001) in patients receiving a hydrophilic-coated sheath. No difference was observed between long and short sheaths. Radial artery occlusion was observed in 9.5% of the patients and was not influenced by sheath length or coating. A local large hematoma or arterial dissection was seen in 2.6% of the patients with no difference in groups allocated at randomization. Younger age, female sex, diabetes, and lower body mass index were identified as independent predictors of radial artery spasm.

CONCLUSIONS

Hydrophilic sheath coating, but not sheath length, reduces the incidence of radial artery spasm during transradial coronary procedures.

Acute compartment syndrome of the forearm that occurred after transradial intervention and was not caused by bleeding or hematoma formation

Recently, transradial angiography and intervention have been performed with high success rates and low rates of vascular complications. The incidence of compartment syndrome after the transradial approach seems to be very low. However, bleeding in the arm can occur and may lead to the devastating complication of compartment syndrome of the forearm, which if not treated early, can evolve into a disability of the arm. In fact, most cases of such complications are caused by guidewire- or catheter-induced damage to small arterial branches that are considerably proximal to the puncture site. However, we encountered a case of compartment syndrome that was not caused by bleeding or hematoma formation and required urgent fasciotomy for its treatment. The forearm wounds were left open to allow the edema to resolve and closed after 1 week. The patient recovered and was discharged, with full movement of his forearm and hand. We suspect that an arterial spasm induced by the radial sheath or catheter resulted in ischemia of the forearm muscles. To our knowledge, this is the first reported case in which acute compartment syndrome of the forearm occurred after transradial intervention and was not due to bleeding or hematoma formation.

Impact of Introducer Sheath Coating on Endothelial Function in Humans After Transradial Coronary Procedures

Background— The aim of this study was to compare the impact of transradial catheterization with hydrophilic-coated catheter sheaths versus uncoated sheaths on NO-mediated endothelial-dependent and -independent vasodilator function.

Methods and Results— Thirty-five subjects undergoing transradial catheterization were recruited and assessed before and the day after catheterization. A subgroup was also assessed 3 to 4 months after catheterization. Subjects received hydrophilic-coated sheaths (n=15) or uncoated sheaths (n=20). Radial artery flow-mediated dilatation and endothelium- and NO-dependent arterial dilatation were assessed within the region of sheath placement. Glyceryl trinitrate endothelium-independent NO-mediated function was also assessed. The noncatheterized arm provided an internal control. Flow-mediated dilatation in the catheterized arm decreased from 10.3�3.8% to 5.3�3.3% and 8.1�2.4% to 5.2�3.7% in the coated and uncoated groups, respectively ( P <0.01). These values returned toward baseline levels ≈3 months later (coated, 6.4�1.4%; uncoated, 9.4�4.1%; P <0.05) versus postprocedure. Glyceryl trinitrate decreased from 14.8�7.2% to 9.5�4.1% ( P <0.05) in the coated group and from 12.2�4.6% to 7.5�4.2% ( P <0.01) in the uncoated group. Values returned to baseline at ≈3 months (coated, 16.6�5.6%; uncoated, 12.1�3.9%; P <0.05). There was no difference in the magnitude of decrease in flow-mediated dilatation or glyceryl trinitrate between coated and uncoated groups. No changes in function occurred in the noncatheterized arm.

Conclusions— Placement of a catheter sheath inside the radial artery disrupts vasodilator function, which recovers after 3 months. No differences were evident between hydrophilic-coated and uncoated sheaths.

Prevention of arterial spasm during percutaneous coronary interventions through radial artery: The SPASM study

AIMS

Radial artery spasm remains the major limitation of transradial approach for percutaneous coronary interventions. The aim of our study was to evaluate the efficacy of vasodilators in the prevention of radial artery spasm during percutaneous coronary interventions.

METHODS AND RESULTS

1,219 patients were consecutively randomized to receive placebo (n = 198), molsidomine 1 mg (n = 203), verapamil 2.5 mg (n = 409), 5 mg (n = 203) or verapamil 2.5 mg and molsidomine 1 mg (n = 206). All drugs were administered through the arterial sheath. The primary end point was the occurrence of a radial artery spasm defined by the operator as severe limitation of the catheter movement, with or without angiographic confirmation. Main characteristics including age, sex, wrist and arterial sheath diameters and procedure duration were identical across the groups. The rate of radial artery spasm was lowest in patients receiving verapamil and molsidomine (4.9%), compared to verapamil 2.5 mg or 5 mg (8.3 and 7.9%), or molsidomine 1 mg (13.3%); and placebo (22.2%) (P < 0.0001).

CONCLUSION

Radial artery spasm during transradial percutaneous interventions was effectively prevented by the administration of vasodilators. The combination of verapamil 2.5 mg and molsidomine 1 mg provided the strongest relative risk reduction of spasm compared to placebo and should therefore be recommended during percutaneous coronary interventions through the radial approach.

Radial versus femoral approach for percutaneous coronary diagnostic and interventional procedures; Systematic overview and meta-analysis of randomized trials

OBJECTIVES

We sought to compare, through a meta-analytic process, the transradial and transfemoral approaches for coronary procedures in terms of clinical and procedural outcomes.

BACKGROUND

The radial approach has been increasingly used as an alternative to femoral access. Several trials have compared these two approaches, with inconclusive results.

METHODS

The MEDLINE, CENTRAL, and conference proceedings from major cardiologic associations were searched. Random-effect odds ratios (ORs) for failure of the procedure (crossover to different entry site or impossibility to perform the planned procedure), entry site complications (major hematoma, vascular surgery, or arteriovenous fistula), and major adverse cardiovascular events (MACE), defined as death, myocardial infarction, emergency revascularization, or stroke, were computed.

RESULTS

Twelve randomized trials (n = 3,224) were included in the analysis. The risk of MACE was similar for the radial versus femoral approach (OR 0.92, 95% confidence interval [CI] 0.57 to 1.48; p = 0.7). Instead, radial access was associated with a significantly lower rate of entry site complications (OR 0.20, 95% CI 0.09 to 0.42; p < 0.0001), even if at the price of a higher rate of procedural failure (OR 3.30, 95% CI 1.63 to 6.71; p < 0.001).

CONCLUSIONS

The radial approach for coronary procedures appears as a safe alternative to femoral access. Moreover, radial access virtually eliminates local vascular complications, thanks to a time-sparing hemostasis technique. However, gaining radial access requires higher technical skills, thus yielding an overall lower success rate. Nonetheless, a clear ongoing trend toward equalization of the two procedures, in terms of procedural success, is evident through the years, probably due to technologic progress of materials and increased operator experience.

Eversion endarterectomy complicating radial artery access for left heart catheterization

The use of the radial artery for arterial access for left heart catheterization is gaining popularity. We report the first case of traumatic eversion endarterectomy following the removal of the arterial sheath after the cannulation of the radial artery. The patient has no long-term vascular compromise of the limb and did not require surgical intervention.

Transradial coronary angiography in patients with contraindications to the femoral approach: An analysis of 500 cases

The transradial approach to coronary angiography is considered by some to be a route of choice, by others to be a route that should be used only where there are relative contraindications to the femoral approach. We present the largest series to date of patients in whom transradial coronary angiography was undertaken specifically because of contraindications to the femoral approach. Since 1995, patients at this cardiothoracic center have been considered for a transradial approach to coronary angiography if there were relative contraindications to the femoral route. Data from 500 patients was prospectively collected. Patients were aged 66 +/- 9 years; 72% were male. Indications for the radial approach included peripheral vascular disease (305), therapeutic anticoagulation (77), musculoskeletal (59), and morbid obesity (32). Sixty-eight patients (14%) required a radial procedure following a failed femoral approach. Access was right radial 291 (58%), left radial 209 (42%). Eighteen operators were involved, but two operators undertook 355 (71%) of the cases. Catheter gauge was 6 Fr (n = 243; 49%), 5 Fr (219; 43%), and 4 Fr (29; 6%). The procedure was successful in 463 cases [92.6%; 88.2% for nonmajority vs. 94.4% (P < 0.05) for the two majority operators]. Success in males (93.6%) significantly exceeded that in females (90.1%; P < 0.05). In-catheter-laboratory duration was 45 +/- 17 min; fluoroscopy time, 7.5 +/- 6 min; radiation dose, 40 +/- 23 CGy. The procedure was without incident in 408 cases (82%). There were procedural difficulties in 18% of cases, including radial artery spasm (12%) and vasovagal response (5%). The incidence was higher with 6 Fr catheters (23%) than with 5/4 Fr (15%; P < 0.05). Major procedural complications occurred in three cases: brachial artery dissection in one and cardiac arrest in two. Postprocedure major vascular complications numbered three: claudicant pain on handgrip in one, ischemic index finger (with subsequent terminal phalanx amputation due to osteomyelitis) in one, and ischemic hand for 4 hr in one. Patients with contraindications to the femoral approach form a high-risk group. In these patients, transradial cardiac catheterization can be performed successfully and with a low risk of major complications. Minor adverse features remain frequent, occurring in one in five cases, though difficulties are minimized both with increasing operator experience and smaller sheath diameter.