An evaluation of the use of carbon dioxide angiography in endovascular aortic aneurysm repair

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.

Fully Ultrasound-Assisted Endovascular Aneurysm Repair (EVAR): preliminary report

BACKGROUND

Reducing fluoroscopy times and iodine contrast administration during endovascular exclusion (EVAR) of infrarenal aortic aneurysms (AAA) remains a challenge. The purpose of this study was to evaluate the preliminary results of a fully ultrasound-assisted EVAR without iodine contrast administration.

METHODS

Twentyseven consecutive patients, underwent an elective IVUS-assisted EVAR with final CEUS control of correct aneurysm exclusion. In no case intraprocedural injection of iodine contrast medium was performed. The primary study's endpoints were the overall duration of the procedure, duration of fluoroscopy, cumulative radiation dose, the length of intraoperative CEUS control and the comparison of findings between intraoperative CEUS and CT-scan at one month.

RESULTS

Mean duration of the procedure was 130 ± 35 minutes. Overall duration of fluoroscopy was 22 ± 18 minutes. Mean radiation dose was 66 mGy (range, 24 - 82). The mean length of CEUS final control was 8 ± 2 minutes. No type I or type III endoleak was detected either at CEUS or at angio-CT scan at one month from EVAR. CEUS revealed a type II endoleak in 6 patients (22%) , compared to 9 type II endoleaks (33%) detected at angio-CT scan one month after the procedure (p = 0.5).

CONCLUSIONS

Fully ultrasound (IVUS and CEUS) -assisted EVAR is safe, feasible and reliable, completely eliminating the need for iodine contrast medium and reducing the radiation exposure for both patients and surgeons.

CO2 Automated Angiography in Endovascular Aortic Repair Preserves Renal Function to a Greater Extent Compared with Iodinated Contrast Medium. Analysis of Technical and Anatomical Details

BACKGROUND

Contrast induced nephropathy occurs in up to 7.5% of cases in endovascular aortic repair (EVAR). Carbon dioxide (CO₂) has been proposed as an alternative agent to iodinated contrast medium (ICM); however, specific protocols are not universally adopted, and the visualization of the renal arteries may be suboptimal in some cases. The aim of this study was to analyze our CO₂-EVAR experience with automatic injections, in order to identify the anatomical characteristics associated with the best visualization of all the aortic vessels, with particular attention to the lowest renal artery (LoRA).

METHODS

From 2016 to 2019, all EVAR performed with either CO₂ or ICM were analyzed and compared. CO₂-EVAR was performed using an automated injector (600 mm Hg pressure; 100 cc volume); a small amount of ICM was injected in case of difficulty in LoRA visualization or doubts at the completion angiogram. Clinical and CT-Scan preoperative characteristics were considered. The study endpoints were technical success, amount of ICM and radiation dose, postoperative renal function and possible CO₂-related adverse events. Statistical analysis was by Fisher's exact, t-Student, Mann-Whitney tests and ROC curve.

RESULTS

In the considered period, 321 EVAR procedures, 72 (22.4%) with CO₂ and 249 (77.6%) with ICM, were performed. The 2 groups were similar for clinical characteristics and preoperative renal function. ICM was injected in a significantly lower amount in the CO₂-EVAR group (52.8 ± 6.1 vs. 88.1 ±9.2 cc, P < 0.001), which received a significantly higher mean radiation dose (Total DAP: 500,550.8 ± 377,394.6 mGy/cm² CO₂-EVAR vs. 332,301.8 ±230,139.3 mGy/cm² ICM-EVAR, P = 0.001). Postoperative eGFR decreased significantly less in the CO₂-EVAR (2.3 ± 1.1 mL/min) compared with the ICM-EVAR group (10.6 ±5.3 mL/min), P < 0.001. LoRA was correctly visualized in 50/72 (69.4%) cases of CO₂-EVAR, which had a significantly longer proximal neck (Median [IQR]: 30 [14] vs. 18 [15] mm, P = 0.001). At ROC curve, a proximal neck length >24.5 mm was predictive of LoRA visualization (72.1% sensitivity, 73.8% specificity). Three CO₂-EVAR cases had intraoperative transient hypotension with no consequences. Sixteen/72 (22.2%) CO₂-EVAR procedures were performed using 0 cc of ICM.

CONCLUSIONS

CO₂-EVAR by automated injections is safe and requires a lower amount of ICM if compared with ICM-EVAR, with a consequent significant benefit on postoperative renal function. If specific anatomical situations are present, ICM may be completely unnecessary. The radiation dose is however significantly higher, therefore procedural protocols need further refinements.

Percutaneous Endovascular Aortic Aneurysm Repair with INCRAFT Endograft Guided by CO2 Digital Subtraction Angiography in Patients with Renal Insufficiency

Iodinated contrast is the most common contrast agent used during endovascular abdominal aneurysm repair (EVAR). However, its use may worsen kidney function in patients with renal insufficiency. Previous studies have demonstrated the safety and effectiveness of carbon dioxide (CO₂)-EVAR. Here, we report cases of three male patients with mild renal insufficiency (mean age: 79 years) that successfully underwent CO₂-EVAR using INCRAFT ultra-low profile endografts. CO₂ angiography provided the necessary vascular roadmap for safe and effective percutaneous EVAR, eliminating the need for iodinated contrast media and preventing contrast-induced nephropathy.

Peroperative Intravascular Ultrasound for Endovascular Aneurysm Repair versus Peroperative Angiography: A Pilot Study in Fit Patients with Favorable Anatomy

BACKGROUND

The aim of this study was to compare intravascular ultrasound (IVUS) assistance for endovascular aortic aneurysm repair (EVAR) to standard assistance by angiography.

METHODS

From June 2015 to June 2017, 173 consecutive patients underwent EVAR. In this group, 69 procedures were IVUS-assisted with X-ray exposure limited to completion angiography for safety purposes because an IVUS probe does not yet incorporate a duplex probe (group A), and 104 were angiography-assisted procedures (group B). All IVUS-assisted procedures were performed by vascular surgeons with basic duplex ultrasound (DUS) training. The primary study endpoints were mean radiation dose, duration of fluoroscopy, amount of contrast media administered, procedure-related outcomes, and renal clearance expressed as the glomerular filtration rate (GFR) before and after the procedure. Secondary endpoints were operative mortality, morbidity, and arterial access complications.

RESULTS

Mean duration of fluoroscopy time was significantly lower for IVUS-assisted procedures (24 ± 15 min vs. 40 ± 30 min for angiography-assisted procedures, P < 0.01). Moreover, mean radiation dose (Air KERMA) was significantly lower in IVUS-assisted procedures (76m Gy [44-102] vs. 131 mGy [58-494]), P < 0.01. IVUS-assisted procedures required fewer contrast media than standard angiography-assisted procedures (60 ± 20 mL vs. 120 ± 40 mL, P < 0.01). The mean duration of the procedure was comparable in the two groups (120 ± 30 min vs. 140 ± 30 min, P = 0.07). No difference in renal clearance before and after the procedure was observed in either of the two groups (99.0 ± 4/97.8 ± 2 mL/min in group A and 98.0 ± 3/97.6 ± 5 mL/min in group B) (P = 0.28). The mean length of follow-up was nine months (6-30 months). No postoperative mortality, morbidity, or arterial access complications occurred. No type 1 endoleak was observed. Early type II endoleaks were observed in 21 patients (11%), 12 in the angiography-assisted group (11%) and nine in the IVUS-assisted group (12%). They were not associated with sac enlargement ≥5 mm diameter and therefore did not require any additional treatment.

CONCLUSIONS

Compared with standard angiography-assisted EVAR, IVUS significantly reduces renal load with contrast media, fluoroscopy time, and radiation dose while preserving endograft deployment efficiency. Confirmation from a large prospective study with improved IVUS probes will be required before IVUS-assisted EVAR alone can become standard practice.

The Assessment of Carbon Dioxide Automated Angiography in Type II Endoleaks Detection: Comparison with Contrast-Enhanced Ultrasound

Introduction

Iodinated contrast media completion angiography (ICM-A) may underestimate the presence of type II endoleak (ELII) after endovascular aortic repair (EVAR), particularly if they are at low flow. Contrast-enhanced ultrasound (CEUS) has been proposed as the gold standard in ELII detection during EVAR follow-up. Intraprocedural carbon dioxide (CO₂) angiography has been shown to be useful in this setting; however no comparative studies including these three techniques are currently available. Our aim was to investigate the accuracy of a new automated CO₂ angiographic (CO₂-A) system in the detection of ELII, by comparing it with ICM-A and CEUS.

Methods

A series of consecutive patients undergoing EVAR for abdominal aortic aneurysm (AAA) were enrolled and submitted to ICM-A and CO₂-A during the procedure. The iodinated contrast media were delivered through an automatic injector connected to a pigtail catheter in the suprarenal aorta. CO₂ was delivered through a recently available automatic injector connected to a 10 F sheath positioned in the external iliac artery. All patients were blindly evaluated by CEUS within postoperative day 1. The ICM-A and CO₂-A ability to detect ELII was compared with that of CEUS through Cohen's concordance Index (K).

Results

Twenty-one patients were enrolled in the study. One (5%), seven (33%), and four (19%) ELII were detected by ICM-A, CO₂-A, and CEUS, respectively. The only ELII detected by ICM-A was also detected by CO₂-A and CEUS. Three cases of ELII detected by CO₂-A were not detected by CEUS. All ELII detected by CEUS were visualized by CO₂-A. CEUS and ICM-A showed a poor agreement (Cohen's K: 0.35) while CEUS and CO₂-A showed a substantial agreement (Cohen's K: 0.65) for ELII detection.

Conclusion

CO₂-A is safe and effective method for ELII detection in EVAR, with a significantly higher agreement with CEUS if compared with ICM-A. This trial is registered with 155/2015/U/Oss.

Use of carbon dioxide as an intravascular contrast agent: A review of current literature

Use of X-ray contrast allows us to differentiate between two or more adjacent structures on radiographic studies. The X-ray contrast agent can be the one with increase X-ray absorption, like iodine and a barium X-ray contrast agent or the one with decrease X-ray absorption like air and carbon dioxide contrast agent. Each contrast agent possesses different risks and benefits in various ways. Carbon dioxide as an intravascular contrast agent can be used as an alternative intravascular contrast agent and has superior results in some cases. In patients with renal dysfunction or iodinated contrast allergy, the use of Iodinated Contrast Agent poses the risk of considerable morbidity. Similarly, use of Gadolinium is discouraged in subject with severe renal dysfunction. Use of carbon dioxide (CO₂) as an intravascular contrast, offers an alternative in such patients for certain procedures, as it is not nephrotoxic and it does not incite allergic reactions. It is inexpensive, readily available and due to its unique physical properties, it can be used to image a wide variety of vascular beds and chambers. The aim of this paper is to systemically review the current literature to describe the indications, contraindications, adverse effects, instruments, precautions, latest methodologies and data supporting for the use of CO₂ as a contrast agent.

Contrast induced-acute kidney injury following peripheral angiography with carbon dioxide versus iodinated contrast media: A meta-analysis and systematic review of current literature

OBJECTIVE

We conducted a meta-analysis to compare the incidence of acute kidney injury (AKI) with carbon dioxide (CO₂ ) versus iodinated contrast media (ICM).

BACKGROUND

Contrast induced-acute kidney injury (CI-AKI) is a known complication following endovascular procedures with ICM. CO₂ has been employed as an alternative imaging medium as it is nontoxic to the kidneys.

METHODS

Search of indexed databases was performed and 1,732 references were retrieved. Eight studies (7 observational, 1 Randomized Controlled Trial) formed the meta-analysis. Primary outcome was AKI. Fixed effect model was used when possible in addition to analysis of publication bias.

RESULTS

In this meta-analysis, 677 patients underwent 754 peripheral angiographic procedures. Compared with ICM, CO₂ was associated with a decreased incidence of AKI (4.3% vs. 11.1%; OR 0.465, 95% CI: 0.218-0.992; P = 0.048). Subgroup analysis of four studies that included granular data for patients with chronic kidney disease (CKD) did not demonstrate a decreased incidence of AKI with CO₂ (4.1% vs. 10.0%; OR 0.449, 95% CI: 0.165-1.221, P = 0.117). Patients undergoing CO₂ angiography experienced a higher number of nonrenal events including limb/abdominal pain (11 vs. 0; P = 0.001) and nausea/vomiting (9 vs. 1; P = 0.006).

CONCLUSIONS

In comparison to ICM, CO₂ use is associated with a modestly reduced rate of AKI with more frequent adverse nonrenal events. In studies that use CO₂ as the primary imaging agent, the average incidence of AKI remained high at 6.2%-supporting the concept that factors other than renal toxicity from ICM may contribute to renal impairment following peripheral angiography. © 2017 Wiley Periodicals, Inc.

Endoleak visualized with carbon dioxide angiography during endovascular aneurysm repair using the Endurant stent-graft

PURPOSE

To make interventionists aware of the potential for type IV endoleak on completion carbon dioxide (CO2) angiography during endovascular aneurysm repair (EVAR) using the Endurant stent-graft.

CASE REPORT

A 74-year-old man with chronic kidney disease underwent EVAR with an Endurant stent-graft using CO2 angiography to guide graft placement. Completion CO2 angiography demonstrated immediate accumulation of CO2 in the aneurysm sac suggestive of an endoleak, but confirmatory angiography with conventional iodinated contrast showed no evidence of an endoleak. We speculate that this is a type IV endoleak, and graft porosity may be responsible.

CONCLUSION

Interventionists should be alerted to the possibility of visualizing these endoleaks through Endurant stent-grafts under CO2 angiography. Further work should be done to elucidate the exact mechanism of the endoleak.

Carbon dioxide digital subtraction angiography as an option for detection of endoleaks in endovascular abdominal aortic aneurysm repair procedure

OBJECTIVE

The purpose of this study was to evaluate carbon dioxide digital subtraction angiography (CO2-DSA) as an option for the detection of endoleaks (ELs) in the endovascular abdominal aortic aneurysm repair (EVAR) procedure.

METHODS

Forty patients with abdominal aortic aneurysm who were scheduled to undergo EVAR were enrolled in the study. There were 35 men and five women (mean age, 77.9 years). All patients had both iodinated contrast conventional DSA (C-DSA) and CO2-DSA immediately after EVAR. The sensitivity and specificity were calculated for the ability of CO2-DSA to detect ELs. We also correlated with computed tomography findings 6 months after EVAR.

RESULTS

C-DSA showed that 27 of the 40 patients (68%) had 28 ELs (type I, four; type II, 20; type III, three; type IV, one). CO2-DSA showed that 16 of the 40 patients (40%) had 17 ELs (type I, four; type II, 10; type III, three; type IV, none). For the prediction of direct ELs (type I and type III) with use of C-DSA as the criterion standard, CO2-DSA has a sensitivity of 1.0 and a specificity of 1.0. For the detection of persistent type II ELs (n = 11) with use of computed tomography findings 6 months from EVAR as the criterion standard, CO2-DSA has a sensitivity of 0.87 and a specificity of 0.97. C-DSA has a sensitivity of 0.82 and a specificity of 0.64.

CONCLUSIONS

CO2-DSA is reliable for the detection of direct ELs and persistent type II ELs in EVAR. CO2-DSA can be an option to detect ELs in the EVAR procedure.

A prospective study of carbon dioxide digital subtraction versus standard contrast arteriography in the detection of endoleaks in endovascular abdominal aortic aneurysm repairs

BACKGROUND

The objective of this study is to compare intraoperative endoleak detection by carbon dioxide digital subtraction angiography (CO(2)-DSA) during endovascular aortic aneurysm repair (EVAR) with standard iodinated contrast angiography (ICA).

METHODS

Between 2006 and 2010, 76 patients with abdominal aortic aneurysms undergoing EVAR were enrolled in a prospective study. After EVAR, both an ICA and CO(2)-DSA completion study were performed. Two blinded vascular surgeons who were not involved with the EVAR separately interpreted the ICA and CO(2)-DSA results for the presence or absence of an endoleak. Identified endoleaks were classified by types. A third, "tie-breaker" blinded observer was used to resolve differences in interpretations. The sensitivity, specificity, negative predictive value, and positive predictive value were calculated for the ability of CO(2)-DSA to detect endoleaks. Cohen's κ statistic was used to assess interobserver agreement between the 2 initial interpreting surgeons.

RESULTS

Of the 76 patients undergoing EVAR, 66 were men with average age of 76 years, a mean aneurysm size of 5.8 cm (range, 4-10 cm), and creatinine of 1 (standard deviation, 0.33). ICA identified 35 type I and 15 type II endoleaks, respectively, while CO(2)-DSA identified 40 type I and 10 type II endoleaks. Overall, CO(2)-DSA had a sensitivity of 0.84, specificity of 0.72, positive predictive value of 0.86, and negative predictive value of 0.69 of intraoperative endoleak detection, with respect to ICA as the criterion standard. The interobserver κ between surgeons for ICA was 0.56, for detection of any endoleak or type I endoleak with CO(2)-DSA was 0.58, and for detection of type II endoleak with CO(2)-DSA was 0.29.

CONCLUSIONS

Interobserver agreement for the detection of endoleaks is superior with ICA compared to CO(2)-DSA. However, the sensitivity for detecting any endoleak and both the sensitivity and specificity for detecting type I endoleaks using CO(2)-DSA are acceptable. For detecting type II endoleaks using CO(2)-DSA, the sensitivity and positive predictive value are poor. Compared to ICA, CO(2)-DSA provides adequate images for endoleak detection during EVAR and is an acceptable alternative to ICA in patients at risk for contrast-related nephrotoxicity.

Endovascular abdominal aortic aneurysm repair in the geriatric population

Abdominal aortic aneurysm (AAA) is a relatively common pathology among the elderly. More people above the age of 80 will have to undergo treatment of an AAA in the future. This review aims to summarize the literature focusing on endovascular repair of AAA in the geriatric population. A systematic review of the literature was performed, including results from endovascular abdominal aortic aneurysm repair (EVAR) registries and studies comparing open repair and EVAR in those above the age of 80. A total of 15 studies were identified. EVAR in this population is efficient with a success rate exceeding 90% in all cases, and safe, with early mortality and morbidity being superior among patients undergoing EVAR against open repair. Late survival can be as high as 95% after 5 years. Aneurysm-related death over long-term follow-up was low after EVAR, ranging from 0 to 3.4%. Endovascular repair can be offered safely in the geriatric population and seems to compare favourably with open repair in all studies in the literature to date.

Endovascular aortic aneurysm repair with carbon dioxide-guided angiography in patients with renal insufficiency

OBJECTIVE

Renal dysfunction following endovascular abdominal aortic aneurysm repair (EVAR) remains a significant source of morbidity and mortality. We studied the use of carbon dioxide (CO(2)) as a non-nephrotoxic contrast agent for EVAR.

METHODS

Recorded data from 114 consecutive patients who underwent EVAR with CO(2) as the contrast agent over 44 months were retrospectively analyzed. CO(2) was used exclusively in 72 patients and in an additional 42 patients iodinated contrast (IC) was given (mean, 37 mL). Renal and hypogastric artery localization and completion angiography were done with CO(2) in all patients, including additional arterial embolization in 16 cases. Preoperative National Kidney Foundation glomerular filtration rate (GFR) classification was normal in 16 patients, mildly decreased in 52, moderate to severely decreased in 44, and two patients were on dialysis.

RESULTS

All graft deployments were successful with no surgical conversions. CO(2) angiography identified 20 endoleaks (two type 1, 16 type 2, and two type 4) and three unintentionally covered arteries. Additional use of IC in 42 patients did not modify the procedure in any case. When compared with a cohort of patients who underwent EVAR using exclusively IC, the operative time was shorter with CO(2) (177 vs 194 minutes; P = .01); fluoroscopy time was less (21 vs 28 minutes; P = .002), and volume of IC was lower (37 vs 106 mL; P < .001). Postoperatively, there were two deaths, two instances of renal failure requiring dialysis, and no complications related to CO(2) use. Among patients with moderate to severely decreased GFR, those undergoing EVAR with IC had a 12.7% greater decrease in GFR compared with the CO(2) EVAR group (P = .004). At 1, 6, and 12-month follow-up, computed tomography angiography showed well-positioned endografts with the expected patent renal and hypogastric arteries in all patients and no difference in endoleak detection compared with the IC EVAR group. During follow-up, eight transluminal interventions and one open conversion were required, and no aneurysm-related deaths occurred.

CONCLUSIONS

CO(2)-guided EVAR is technically feasible and safe; it eliminates or reduces the need for IC use, may expedite the procedure, and avoids deterioration in renal function in patients with pre-existing renal insufficiency. A prospective trial comparing CO(2) with IC during EVAR is warranted.