Digital subtraction angiography of the abdominal aorta and lower extremities: carbon dioxide versus iodinated contrast material

Comparing the accuracy and safety of automated CO2 angiography to iodine angiography in peripheral arterial disease with chronic limb ischemia: a prospective cohort study

Introduction

Diagnostic angiography of peripheral arteries using carbon dioxide (CO2) is feasible in nearly all areas below the diaphragm. Using carbon dioxide as a contrast material in angiography provides the highest quality diagnostic results in the vascular segments above the knee. However, its diagnostic reliability decreases as it moves toward the distal side of the vessels below the knee. This study investigated the diagnostic accuracy and consistency between CO2 and iodine contrast angiography in patients with peripheral vascular disease (PVD) with chronic limb ischemia (CLI).

Methods

The study prospectively enrolled 35 patients with PVD and CLI and performed both CO2 and iodine contrast angiography, comparing the results for each patient. Image quality, stenosis severity, and anatomical location were analyzed.

Results

In this study, a total of 35 patients (19 male) with an average age of 56.91 ± 10.73 were examined. Among them, 13 patients (37.1%) had involvement in the femoral region, 8 patients (22.9%) in the popliteal region, 8 patients (22.9%) in the tibial region, and 6 patients (17.1%) in the foot region. CO2 angiography produced excellent image quality in 40% of cases, with good quality in another 25.7%. The quality decreased in the popliteal and foot regions. While stenosis assessment was comparable between the two methods in the femoral, popliteal, and tibial regions, there was a significant difference in the foot region. The sensitivity, specificity, positive predictive value, and negative predictive value of CO2 angiography were all 100% in the femoral and popliteal areas. However, these values were lower in the tibial and foot areas.

Discussion

The study concluded that the use of CO2 angiography, particularly for vascular lesions above the popliteal cavity, is a valuable and safe method for peripheral vascular examination of the lower limbs. It can serve as an alternative to iodine contrast angiography, especially in patients with kidney failure.

Safety and Effectiveness of Carbon Dioxide Contrast Medium in Infra-Inguinal Endovascular Interventions for Patients With Chronic Threatening Lower Limb Ischemia and Renal Impairment: A Multicentric Trial

PURPOSE

To assess the safety and effectiveness of using carbon dioxide (CO2) contrast in both supra- and infra-genicular endovascular interventions in patients with renal impairment.

MATERIAL AND METHODS

This is a multicentric prospective observational study conducted over a period of 3 years from 2017 to 2020; the study included 114 patients presented with chronic threatening limb ischemia (CTLI) and renal impairment (lowest serum creatinine levels ≥1.3 mg/dL) for whom endovascular procedures were done using CO2 as a contrast medium. Endovascular angiography was guided by CO2 either exclusively (zero contrast) or with the aid of small amount of supplementary iodinated contrast media (ICM) injections. The qualitative assessment of the angiographic images in both supra- and infra-genicular fields were reported and scaled.

RESULTS

The qualitative diagnostic images were excellent in 86.5% in the supra-genicular and 66.5% in infra-genicular images. There were no significant changes in mean serum creatinine levels from baseline to first and fifth days post procedural (mean 1.8 mg/dL vs mean 1.9 mg/dL and mean 1.7 mg/dL).

CONCLUSION

CO2 is a non-nephrotoxic alternative to traditional ICM that could be safely used and well tolerated during endovascular interventions for peripheral arterial disease in patients with renal impairment. Primary safety and efficacy endpoints were achieved in 100% of cases. The use of automated injector system provides adequate delivery, optimizes the dose, and avoids air contamination. For infra-genicular segment opacification, we recommend super-selective injections and some changes in angiographic techniques from contrast preparation to image post-processing.

CLINICAL IMPACT

Co2 is a non-nephrotoxic alternative to traditional ICM that could be safely used and well tolerated during peripheral endovascular interventions in patients with renal impairment. The use of automated injector system would provide adequate delivery, optimizes the dose and avoids air contamination. For infra-genicular segment opacification, its recommended to use selective injection as close to the target artery as possible and some changes in angiographic techniques from contrast preparation to image post-processing.

Carbon dioxide-angiography for patients with peripheral arterial disease at risk of contrast-induced nephropathy

Patients with peripheral arterial disease (PAD) and critical limb ischemia are at risk for limb amputation and require urgent management to restore blood flow. Patients with PAD often have several comorbidities, including chronic kidney disease, diabetes mellitus, and hypertension. Diagnostic and interventional angiography using iodinated contrast agents provides excellent image resolution but can be associated with contrast-induced nephropathy (CIN). The use of carbon dioxide (CO₂) as a contrast agent reduces the volume of iodine contrast required for angiography and reduces the incidence of CIN. However, CO₂ angiography has been underutilized due to concerns regarding safety and image quality. Modern CO₂ delivery systems with advanced digital subtraction angiography techniques and hybrid angiography have improved imaging accuracy and reduced the incidence of CIN. Awareness of the need for optimal imaging conditions, contraindications, and potential complications have improved the safety of CO₂ angiography. This review aims to highlight current technological advances in the delivery of CO₂ in vascular angiography for patients with PAD and critical limb ischemia, which result in limb preservation while preventing kidney damage.

Current status of carbon dioxide angiography

OBJECTIVE

Unfamiliarity of endovascular surgeons with carbon dioxide (CO₂) angiography is one of the main reasons for its limited use. This review is intended to familiarize the reader with the principles and applications of that modality.

METHODS

We conducted a comprehensive review of contemporary literature related to CO₂ angiography and its use in the field of vascular and endovascular surgery, including technical details and diagnostic and interventional applications.

RESULTS

Cardinal physicochemical characteristics of CO₂ include buoyancy, ultralow viscosity, and nonmixing with blood. Because of the risk of neurotoxicity, intra-arterial CO₂ angiography should only be performed below the diaphragm. Venous CO₂ angiography can be performed anywhere in the torso and extremities. Ultralow viscosity enables intraprocedural imaging during vascular interventions without the need to exchange for an angiographic catheter. Benefits, advantages, and emerging applications of CO₂ angiography are listed. Potential complications and their avoidance and troubleshooting are discussed.

CONCLUSIONS

CO₂ holds promise as an effective and versatile angiographic contrast agent. It is also a valuable modality for the guidance of endovascular interventions. Current availability of easy to use, safe, and portable CO₂ delivery systems will likely expand the use of that modality even beyond the traditional indications of renal insufficiency and iodinated contrast allergy.

Lowering iodinated contrast concentration in infrainguinal endovascular interventions: a three-armed randomized controlled non-inferiority trial

Objectives

To determine the influence of lowering iodinated contrast concentration on confidence of interventional radiologists in diagnosing and treating lesions during endovascular interventions in patients with symptomatic peripheral arterial disease (PAD).

Methods

A randomized controlled non-inferiority trial was performed in 60 patients. Intervention was performed with contrast concentrations (in mg of iodine per mL, mgI/mL) of 300 (standard), 240, or 140 mgI/mL. Primary outcome was confidence (score 0-100 %) of radiologists in diagnosing and treating arterial lesions. Secondary outcomes were procedural iodine load and image quality (i.e. non-diagnostic, limited, diagnostic, exemplary).

Results

Median confidence scores in diagnosing lesions were 100 % (range 81-100 %) for the 300 group (n = 21), 100 % (range 82-100 %) for the 240 group (n = 19), and 100 % (range 91-100 %) for the 140 group (n = 20) (both p = 1.00 compared to the 300 group). Median scores for treating lesions in the 240 and 140 groups, 100 % (range 79-100 %, p = 0.40), and 100 % (range 63-100 %, p = 0.25), respectively, were not lower compared to the 300 group (median 100 %, range 78-100 %). Procedural iodine load was lower in the 240 (24.3 ± 7.6 g, p = 0.022) and 140 groups (17.8 ± 5.6 g, p < 0.001) compared to the 300 group (29.7 ± 6.3 g). Image quality was diagnostic for all groups.

Conclusion

Using iodine contrast of 140 mgI/mL for diagnosis and interventions in PAD patients significantly reduces administered iodine load without compromising image quality. Future use of lower iodine dose is recommended.

Key Points

• Lower iodinated contrast concentration during endovascular intervention does not decrease radiologist’s confidence.

• Image quality of standardized angiographies remains diagnostic using 140 mgI/mL iodinated contrast concentration.

• Iodine load during intervention can be decreased by >40 % when using 140 mgI/mL.

• Implementing the use of a lower iodinated contrast concentration will reduce the costs of the procedure.

Automated Carbon Dioxide Angiography for the Evaluation and Endovascular Treatment of Diabetic Patients With Critical Limb Ischemia

PURPOSE

To test the safety, efficacy, and diagnostic accuracy of automated carbon dioxide (CO2) angiography (ACDA) for the evaluation of diabetic patients with critical limb ischemia (CLI) and baseline renal insufficiency and compare ACDA with iodinated contrast medium (ICM) during endovascular treatment.

METHODS

From November 2014 to January 2015, 36 consecutive diabetic patients (mean age 74.8±5.8 years; 27 men) with stage ≥3 chronic kidney disease (CKD ≥3) and CLI underwent lower limb angiography with both CO2 and ICM followed by balloon angioplasty in a prospective single-center study. The primary outcome measure was the safety and efficacy of ACDA as the exclusive agent to guide angioplasty in this cohort. The secondary outcomes were the safety and diagnostic accuracy of ACDA injection as compared with ICM digital subtraction angiography (DSA) for invasive evaluation of these patients.

RESULTS

ACDA safely and effectively guided angioplasty in all patients without complications. Transcutaneous oxygen pressure improved from 11.8±6.3 to 58.4±7.6 mm Hg (p<0.001). There were no complications related to ACDA during diagnostic imaging and no significant changes in the estimated glomerular filtration rate from baseline to 24 hours (44.7±13.3 vs 47.0±0.8 mL/min/1.73 m(2); nonsignificant). The diagnostic accuracy of CO2 was 89.8% (sensitivity 92.3%; specificity 75%; positive predictive value 95.5%; negative predictive value 63.1%). There was no statistically significant difference in the qualitative diagnostic accuracy between the media (p=0.197).

CONCLUSION

ACDA is an accurate, safe, and effective technique that can be utilized to guide endovascular interventions in diabetics with CLI and baseline CKD ≥3. Larger multicenter randomized studies are needed to validate these results.

Diabetes revealed: multisystem danger

OBJECTIVE

The purpose of this article is to review the role of diagnostic imaging in the evaluation of women with diabetes.

CONCLUSION

Diabetic patients present a challenging population for the performance of various imaging studies and special considerations need to be made to obtain adequate studies. Imaging plays a significant role in assessing the multisystem morbidity of diabetes. Furthermore, diabetes in women may have some unique features and consequences and imaging studies can aid in the correct management of these patients.

Comparison of intra-arterial digital subtraction angiography using carbon dioxide by 'home made' delivery system and conventional iodinated contrast media in the evaluation of peripheral arterial occlusive disease of the lower limbs

To prospectively compare the feasibility, safety and diagnostic role of carbon dioxide (CO(2)) digital subtraction angiography (DSA) using a 'home made' delivery system with iodinated contrast medium (ICM) DSA in the evaluation of peripheral arterial occlusive diseases (PAOD) of lower limbs. Twenty-one patients (27 limbs; all men; mean age, 47.6 years) who presented with PAOD of lower limbs underwent DSA using both intra-arterial CO(2) and ICM. Conventional ICM DSA was performed first and used as gold standard. Carbon dioxide was then injected by hand using a locally improvised home made plastic bag delivery system. Patient tolerance was assessed subjectively. Arteries from aortic bifurcation to the ankle were independently evaluated by two radiologists and graded for stenosis using a five-point scale. For each patient, the quality of CO(2) DSA images were compared with the corresponding images of ICM DSA and an overall grade of 'good', 'acceptable' or 'poor' was assigned. Cohen's kappa coefficient was used to determine inter-observer agreement. Carbon dioxide opacified 86.2% (188/195) of major arteries and depicted stenosis adequately in 84.5% (191/226) of arterial segments. A good or acceptable image quality of CO(2) DSA was obtained in over 95% of patients. Infrapopliteal arteries were inadequately visualized. Mild pain was seen in six (28.6%) patients with both contrast agents; one patient developed severe pain during CO(2) DSA. Inter-observer agreement was good (k > 0.75) at 70% of the segments. Administration of CO(2) into lower limb arteries is well tolerated. Carbon dioxide DSA using the locally improvised home made delivery system is a feasible and safe alternative to ICM DSA in the evaluation of PAOD. It provides adequate imaging of arteries of lower extremities except infrapopliteal segments.

Upper-extremity venography: CO2 versus iodinated contrast material

PURPOSE

To determine prospectively the diagnostic performance of CO(2) venography, by using conventional venography with iodinated contrast material as the reference standard, for the preoperative evaluation of upper-limb and central veins before creation of fistulas for hemodialysis access.

MATERIALS AND METHODS

The study was approved by the institutional review board, and informed consent was obtained from all patients. Twenty-two patients underwent comparative CO(2) and conventional venography of upper-extremity and central veins. Two independent observers evaluated the opacification of the veins and grade of stenosis, if present. Interobserver agreements were estimated with the Cohen kappa coefficient. Calculations of sensitivity, specificity, and accuracy were used for intertechnique observations.

RESULTS

For CO(2) venography, global interobserver agreement was good, with a kappa value of 0.90 (range, 0.71-1.00; 95% confidence interval: 0.84, 0.95). A kappa value of 0.96 (range, 0.86-1.00; 95% confidence interval: 0.93, 0.99) was calculated for global interobserver agreement for conventional venography. The sensitivity, specificity, and accuracy of CO(2) venography for all vein segments were 97%, 85%, and 95%, respectively.

CONCLUSION

CO(2) venography had a sensitivity of 97% and a specificity of 85% in the assessment of upper-limb and central vein patency and stenosis, with conventional venography used as the reference standard.

The Current Status of the Use of Carbon Dioxide in Diagnostic and Interventional Angiographic Procedures

Since the first description of carbon dioxide (CO(2)) angiography the indications for using CO(2) have been changing and the applications of CO(2) angiography evolving. This review covers the contemporary role of CO(2) angiography. CO(2) angiography can be considered according to whether it is likely to be better, equivalent to or worse than conventional iodinated contrast medium (ICM). Areas where CO(2) angiography offers distinct advantages over ICM will be emphasized. The limitations to using CO(2) and specific caveats will be discussed. The basic physical properties of CO(2) and avoidance of the complications of gas angiography will be considered. CO(2) gas is cheap, non-allergenic, and is not nephrotoxic. Unfortunately it is not a panacea, angiographic quality is reduced, it is not tolerated by every patient, and it cannot be used in every location. It is important to be pragmatic and to use conventional contrast or alternative imaging rather than struggling with suboptimal CO(2) angiography.

Estudo angiográfico de fístula arteriovenosa utilizando gás carbônico como meio de contrante

OBJETIVO: Este estudo tem por finalidade obter um método diagnóstico angiográfico alternativo que possa ser utilizado em doentes com alto risco ao uso de meio de contraste iodado. MATERIAIS E MÉTODOS: Foram estudados 26 doentes com insuficiência renal crônica, que tiveram suas fístulas analisadas, submetidos à angiografia digital - na primeira fase, utilizando o meio de contraste iodado e, na segunda fase, gás carbônico como meio de contraste, com registro em filme angiográfico. A angiografia foi avaliada por dois médicos independentes, que analisaram a opacificação, o diagnóstico radiológico e o calibre dos vasos; a análise comparativa das medidas da artéria, da veia e da freqüência respiratória antes e após a injeção de contraste foi realizada pelo autor. RESULTADOS: Os resultados obtidos pela analise estatística utilizando coeficiente kappa apresentaram concordância entre os dois médicos, referente à opacificação, de 0,3217, referente ao diagnóstico radiológico, de 0,5583, e referente à analise de calibre dos vasos, de 0,4298. A análise das medidas da artéria e da veia não apresentou diferença significativa pela medida de posição e dispersão, mostrando concordância na regressão linear, com p-valor de 0,3657 e de 0,2041; para a freqüência respiratória, as análises das medidas de posição e dispersão não apresentaram diferença significativa. CONCLUSÃO: Concluímos ser este método uma alternativa no estudo angiográfico em pacientes com antecedente alérgico ou com risco nefrotóxico.

Cost-effectiveness targets for multi-detector row CT angiography in the work-up of patients with intermittent claudication

PURPOSE

To determine the costs, sensitivity for detection of significant stenoses, and proportion of equivocal multi-detector row computed tomographic (CT) angiography results in the work-up of patients with intermittent claudication that would make this imaging examination cost-effective compared with gadolinium-enhanced magnetic resonance (MR) angiography.

MATERIALS AND METHODS

A decision model was used to compare the societal cost-effectiveness of a new imaging modality with that of gadolinium-enhanced MR angiography. Main outcome measures were quality-adjusted life years (QALYs) and lifetime costs. By using threshold analysis of a given willingness to pay per QALY, target values for costs, sensitivity for detection of significant stenoses, and proportion of cases requiring additional work-up with intraarterial digital subtraction angiography owing to equivocal results of the new modality were determined. The base case evaluated was that of 60-year-old men with severe intermittent claudication and assumed an incremental cost-effectiveness threshold of 100,000 US dollars per QALY.

RESULTS

If treatment were limited to angioplasty, a new imaging modality would be cost-effective if the costs were 300 US dollars and the sensitivity was 85%, even if up to 35% of patients needed additional work-up. When both angioplasty and bypass surgery were considered as treatment options, a new imaging modality was cost-effective if the costs were 300 US dollars, the sensitivity was higher than 94%, and 20% of patients required additional work-up.

CONCLUSION

Multi-detector row CT angiography, as compared with currently used imaging modalities such as MR angiography, has the potential to be cost-effective in the evaluation of patients with intermittent claudication.

X-ray digital subtraction angiography with 1 mol/L gadobutrol: results from a comparative porcine study With iodinated contrast agents

RATIONALE AND OBJECTIVES

To evaluate prospectively diagnostic accuracy of 1 mol/L gadobutrol as a contrast agent for intraarterial x-ray digital subtraction angiography (DSA) in comparison to iodinated, nonionic contrast media and 0.5 mol/L gadolinium-DTPA.

METHODS

Flush arteriograms (ascending, descending, abdominal aorta, iliac, and femoral arteries) and selective angiograms (carotid, renal, and visceral arteries) were obtained from bilateral femoral arterial access (5 F sheaths) in 10 domestic pigs (70 kg body weight). Digital subtracted angiograms were obtained during injection of undiluted 1 mol/L gadobutrol, 300 mg I/mL iopromide, or 0.5 mol/L gadopentetate. Injection parameters (volume and velocity) were similar for all three contrast agents. In paired arteries, two different contrast media were used during the same angiographic run. Diagnostic quality and accuracy of the angiograms were evaluated on a three-step scale by three independent blinded investigators.

RESULTS

Sufficient nonselective angiographic images were obtained in 90% of cases using iodinated contrast material. Gadobutrol achieved sufficient nonselective angiograms in 64%. Selective angiograms were sufficient in 98% using iodinated contrast material, 90% using 1 mol/L Gadobutrol and 48% using 0.5 mol/L Gd-DTPA. Adverse reactions to any of the used contrast agents were not noted.

CONCLUSION

One mol/L Gadobutrol solution allows x-ray digital subtraction angiography with a diagnostic accuracy equivalent to 300 mg/mL iodinated contrast media, if selective injections are performed. Flush aortograms are of inferior image quality to iodinated contrast material.

The use of gadolinium chelates for X-ray digital subtraction angiography

RATIONALE AND OBJECTIVES

To evaluate the feasibility and safety of using gadolinium chelates for x-ray digital subtraction angiography (DSA) in patients with contraindications to iodinated contrast material.

METHODS

We performed 30 DSAs in 22 patients (5 females, 17 males; mean age 64.9 years) with contraindications to iodinated contrast media (renal insufficiency: n = 28; hyperthyroidism: n = 1; contrast allergy: n = 2). Gadolinium chelates were administered as 0.5 mol/L solutions (mean volume of gadolinium chelates per patient was 34 +/- 19 mL). Gadolinium chelates were the sole contrast agent in 17 examinations, were used in conjunction with carbon dioxide (CO2) in 8 studies, (mean 212 +/- 226 mL), and were combined with the restricted use of nonionic iodinated contrast (mean 12.8 +/- 4.7 mL) in 6 examinations. We carried out 15 diagnostic angiographies and 15 percutaneous transluminal angioplasties.

RESULTS

Use of gadolinium chelates allowed us to obtain diagnostic angiographic images in all cases. However, the quality of angiograms was inferior compared with that obtained with iodinated contrast agents and superior compared with CO2 as the contrast material. Adverse events were not noted. Mean serum creatinine was 2.6 +/- 1.5 mg/dL before and 2.3 +/- 1.0 mg/dL after DSA. No patient developed contrast-induced nephropathy.

CONCLUSIONS

Gadolinium chelates produce an x-ray DSA intermediate in image quality between iodinated contrast and CO2. Digital subtraction angiography with intra-arterial gadolinium chelate administration may offer an alternative to iodinated contrast material in patients with contraindications to iodine.