CO2 Digital Subtraction Angiography Research Articles

Carbon Dioxide Pyelography: A Convenient and Safe Alternative to Both Room Air and Iodinated Contrast Pyelography During Endourologic Procedures.

Introduction/Background: There are increasing reports of serious complications related to the air pyelography technique, which raise concerns about the safety of room air (RA) injection into the renal collecting system. Carbon dioxide (CO2) is much more soluble in blood than nitrogen and oxygen and thus considerably less likely to cause gas emboli. Iodinated contrast medium (ICM) is expensive, and supplies may not be as reliable as previously assumed. CO2 pyelography (CO2-P) techniques using standard fluoroscopy and digital subtraction fluoroscopy (CO2 digital subtraction pyelography [CO2-DSP]) are described. Materials and Methods: During the endourologic stone cases, 15 to 20 mL of CO2 gas was typically injected into the renal pelvis through a catheter or sheath. Imaging was usually obtained with endovascular CO2 digital subtraction angiography settings using either a traditional fluoroscopy system (TFS) or robotic arm multiplanar fluoroscopy system (RMPFS) (Artis Zeego Care+Clear®; Siemens). Results: CO2-P was performed in 22 endoscopic stone treatment cases between March 2021 and August 2022, primarily using digital subtraction settings in 20 cases. CO2-DSP overall provided higher quality images of the renal pelvis and collecting system than CO2-P, but with a relatively higher radiation dose. Following a quality intervention, fluoroscopy doses for CO2-DSP cases were decreased by 81% overall. The use of CO2-P avoided fluoroscopic or intraoperative CT (ICT) artifacts seen with intraluminal ICM. Conclusions: CO2-P allows the urologist to obtain imaging of the renal collecting system without ICM and with much lower risk of air embolism compared with RA pyelography. CO2 is a nearly cost-free alternative to ICM. Because CO2 is widely available and the technique is easy to perform, we propose that CO2-P should be favored over traditional air pyelography to improve patient safety.

Endovascular Aneurysm Repair Assisted by CO2 Digital Subtraction Angiography and Intraoperative Contrast-Enhanced Ultrasonography: Single-Center Experience

Allergy to iodinated contrast (IC) agent and advanced chronic kidney disease are major limitations to endovascular repair (EVAR) of abdominal aortic aneurysms (AAAs). We describe our experience combining CO2-assisted EVAR with intraoperative contrast-enhanced ultrasound (CEUS) in an attempt to avoid contrast-induced allergy or nephropathy. Observational cohort study using prospectively acquired data on patients undergoing CO2-assisted EVAR in single institution. EVAR planning was performed using computed tomographic angiography or magnetic resonance aortography in patients contraindicated for IC. Patients were considered if their estimated glomerular filtration rate was <40mL/min and anatomically suitable for conventional infrarenal EVAR. Outcomes of interest included technical success rate and reintervention rates, total radiation dose, length of hospital stay, and graft kinking or migration. Fifteen patients (10 male) were treated across a 5-year period. Technical success was achieved in all cases. Completely IC-free EVAR was performed in 9 cases, whereas the remaining 6 required IC administration for adjunct procedures. CO2 completion angiography detected all type I endoleaks (2 Ia and 1 Ib) but was less sensitive to type II. Intraoperative CEUS confirmed all type I and 2 cases of type II endoleaks. Median hospital stay was 4days. No significant deterioration in renal function was seen postoperatively. In patients with abdominal aortic aneurysms and with contraindication for IC, a combined approach of using CO2 digital subtraction angiography and CEUS can be used safely and efficiently to minimize or obviate the need for IC agents with satisfactory mid-term results.

Physiology of Intraluminal Administration of Carbon Dioxide as a Contrast Medium.

Carbon dioxide (CO2) exists in nature around us. In the middle of the 20th century, the intraluminal injection of CO2 demonstrated similar results to those of Digital Subtraction Angiography (DSA) with an iodinated contrast agent (ICA). Since then, the technology behind CO2 DSA has developed significantly. The aim of this study is to inform physicians about the unique properties of CO2 and its physiology after intraluminal injection. An extensive search for English literature on the properties of CO2 and the physiology of intraluminal administration was conducted using Pubmed. There is sufficient literature on the properties of CO2 and the physiology of CO2 DSA. A review of this literature explains what happens to the human organism after the injection of CO2. There is enough evidence that CO2 DSA is both effective, diagnostic and safe, but the properties of CO2 should be taken under consideration as complications occur, although rarely.

Utilization of Carbon Dioxide Angiography and Percutaneous Balloon Angioplasty for Treatment of Transplant Renal Artery Stenosis

Transplant renal artery stenosis (TRAS) may lead to graft dysfunction and failure. Progressive deterioration of renal allograft function may be exacerbated by contrast-induced nephrotoxicity during iodine contrast administration for renovascular imaging of allografts. We present our institutional experience of endovascular management for TRAS using CO2 digital subtraction angiography (CO2-DSA) and balloon angioplasty to manage failing renal transplants. Four patients with renal allografts from March 2017-May 2018 were referred for graft dysfunction and pending renal transplant failure. Indications for referral included refractory hypertension, decreasing renal functioning, and elevated renovascular systolic velocities. Median age of the four patients was 41.5 years (22-60 years). There were two male and female patients. Chronic hypertension and type 2 diabetes mellitus were the most common comorbidities. An average total of 75mL of CO2 was used, supplemented with 17.4mL of iodinated contrast. All patients had improvements in renal function following intervention with a mean decrease in systolic and diastolic blood pressure of 25.8% and 21.4%, respectively. We also observed a mean decrease of BUN by 13.6% and creatinine by 37.4%. Additionally, eGFR increased by 37.7%. All allografts survived after surgery, and only one patient required repeat angioplasty for recurrence. CO2-DSA with balloon angioplasty can be successfully utilized to salvage deteriorating kidney allograft function in patients with TRAS.

Standardization of a Carbon Dioxide Automated System for Endovascular Aortic Aneurysm Repair

Endovascular aortic repair (EVAR) is presently the preferred treatment for abdominal aortic aneurysm; however, it requires the injection of a contrast medium, which can hamper the renal function. Other nontoxic agents such as carbon dioxide (CO2) havebeen sporadically tested in this setting with uncertain results. The aim of the study is to investigate the efficacy of a new standardized CO2 injection method in standard EVAR procedures. Between August and October 2016, 31 consecutive patients (median age 76.1 [interquartile range {IQR}: 7.4] years) were submitted to standard EVAR. Proximal and distal endograft landing zones were identified by the injection of 100mL of CO2 at 300mm Hg, through an 11cm 10F femoral sheath by a specifically manufactured automated injection device (Angiodroid Srl, San Lazzaro, Bologna, Italy). Before EVAR deployment, a confirmative injection with a conventional contrast medium was accomplished. The possibility of precisely visualizing the proximal and distal landing zones by CO2 digital subtraction angiography (DSA) was evaluated considering the contrast medium injection obtained in the same procedure as a gold standard. Similarly, the possible presence of endoleak was assessed at the end of the procedure by the 2 techniques. CO2 DSA allowed to identify the juxtarenal landing zone of the endograft in 19/31 cases (61%) and the distal one in 31/31 (100%). In 12 (39%) cases, CO2 injection failed to visualize at least the lowest renal artery. This occurred in large aneurysms with scarce thrombotic apposition and a luminal volume greater than 95.9 (IQR: 25.2) mm3. Completion CO2 DSA detected type II endoleaks (ELIIs) in 10 cases compared with 2 of conventional contrast media. The injection of nontoxic CO2 through an automated device allowed to perform EVAR procedures effectively, in the majority of cases. In some cases, a single injection of a minimum amount of conventional contrast medium can be used to overcome the lack of renal artery visualization by CO2. ELIIs are more frequently visualized with CO2 compared with standard contrast medium. Although the CO2 injection technique needs further amelioration particularly in the renal arteries detection, this technique appears promising and possibly substitutive of the standard contrast medium, with significant benefit for the renal function.

Accuracy and safety of CO2 digital subtraction angiography during endovascular treatment of symptomatic peripheral artery occlusive disease. A prospective study on Egyptian patients

PurposeTo study the efficacy, safety and clinical outcome of carbon dioxide DSA during angioplasty procedures for patients with predominant femoropopliteal segment occlusive lesions, aiming to reduce possible allergic reactions and potential nephrotoxicity. Materials and methodsThe study included eighteen Egyptian patients in a prospective manner, with evidence of predominant femoropopliteal arterial occlusive disease by Duplex study. All the selected patients had borderline renal functions with serum creatinine levels between 1.5 mg/dL and 2 mg/dL. Every patient was scheduled for a percutaneous endovascular therapy during which CO2 DSA and small volume injections of ICM DSA of the diseased segment and distal arterial tree were done. We analyzed our results emphasizing the technical success, CO2 DSA related complications, allergic reactions and intolerance. We also correlated the amount of contrast injected with the serum creatinine levels as well as the degree of opacification of the diseased segment. ResultsWe were able to achieve technical success in 88% of our cases except in two patients who had TASC D lesions. The average fluoroscopy time in our study was about 100 min. There were no CO2 related complications or allergic reactions. Five patients were intolerant to CO2 injection related pains and repeated injections were performed with smaller volumes. The injected mean volume of CO2 was 76.1 mL while the mean volume of ICM used per patient was 24 mL. Most patients showed non-significant rise of serum creatinine levels at both samples. Moreover, the results of the “Good” score & the “Fair” score for the CO2 DSA image quality plotted by the interobserver agreement was about 40% & 33% respectively from the total number of patients included in the study. ConclusionCO2 DSA is a non-nephrotoxic alternative to traditional ICM DSA that could be safely used and well tolerated during endovascular management of lower extremity symptomatic arterial disease. When selectively delivered to the femoropopliteal segment, CO2 provides superior quality images that would cancel or markedly reduce the ICM volume required for prompt visualization and decision making during the revascularization procedure.

Abstract No. 332 - Carbon dioxide digital subtraction angiography: an alternative for detection endoleaks at endovascular abdominal aortic aneurysm repairs procedure

The purpose of this study is to evaluate CO2- digital subtraction angiography (CO2-DSA) as an alternative for detection endoleak (EL) at EVAR procedure, comparing with iodinated conventional DSA (C-DSA).

Invited commentary

Although in use for digital subtraction angiography (DSA) since about the 1970s,1Hawkins I.F. Carbon dioxide digital subtraction arteriography.AJR Am J Roentgenol. 1982; 139: 19-24Crossref PubMed Scopus (158) Google Scholar carbon dioxide remains a very useful contrast medium in our ever-growing population of patients with renal insufficiency and/or significant iodinated-contrast sensitivity. With the present report, Criado et al add to the existing support for use of CO2 DSA in endovascular aortic aneurysm repair (EVAR). Providing support for alternate imaging methods to deliver endovascular therapy safely is particularly important, considering improving technologies will extend therapy to more patients who are at risk of renal compromise. As others have,2Chao A. Major K. Kumar S.R. Patel K. Trujillo I. Hood D.B. et al.Carbon dioxide digital subtraction angiography-assisted endovascular aortic aneurysm repair in the azotemic patient.J Vasc Surg. 2007; 45: 451-458Abstract Full Text Full Text PDF PubMed Scopus (66) Google Scholar, 3Bush R.L. Lin P.H. Bianco C.C. Lumsden A.B. Gunnoud A.B. Terramani T.T. et al.Endovascular aortic aneurysm repair in patients with renal dysfunction or severe contrast allergy: utility of imaging modalities without iodinated contrast.Ann Vasc Surg. 2002; 16: 537-544Abstract Full Text PDF PubMed Scopus (39) Google Scholar, 4Lee A.D. Hall R.G. An evaluation of the use of carbon dioxide angiography in endovascular aortic aneurysm repair.Vasc Endovasc Surg. 2010; 44: 341-344Crossref PubMed Scopus (19) Google Scholar Criado et al demonstrate that CO2 DSA is safe, and results are comparable with procedures performed with iodinated contrast. The single element that sets this paper apart from previous ones is that radiation times were shorter for CO2 than iodinated contrast; this is inexplicable based even on our own experience. Furthermore, settings are modified for CO2 DSA by increasing the frame rate, a maneuver that tends to increase the radiation dose. In their paper, the authors conclude with a rhetorical question; why should procedures be performed with iodinated contrast if results are equivalent? There are multiple reasons for this: 1) as CO2 is delivered by hand injection, there is significant potential for increased radiation exposure as the interventionalist is always at the table, and this becomes even more relevant if indeed the radiation times are longer as described by previous authors. 2) The potential for complications with air emboli is also increased by the fact that no system is completely sealed; the plastic bag system (AngioFlush 111, AngioDynamics, Queensbury, NY) is being discontinued due to a Food and Drug Administration mandate following a serious complication, where the bag was filled with O2 rather than CO2.5Cho K.J. Hawkins Jr, I.F. Discontinuation of the plastic bag delivery system for carbon dioxide angiography will increase radiocontrast nephropathy and life-threatening complications.AJR Am J Roentgenol. 2011; 197: W940-W941Crossref PubMed Scopus (4) Google Scholar There is some instruction and expertise required to avoid potentially serious complications. 3) In order to prevent overestimating disease, when injecting in the aorta a bolus of 40 to 60 mL of CO2 is required, which can lead to “trapping” of CO2 within a branch, ultimately leading to ischemic insult. This can be somewhat mitigated by patient positioning, but only experience or adequate instruction will prompt such maneuvers.6Spinosa D.J. Matsumoto A.H. Angle J.F. Hagspiel K.D. Hooper T.N. Transient mesenteric ischemia: a complication of carbon dioxide angiography.J Vasc Interv Radiol. 1998; 9: 561-564Abstract Full Text PDF PubMed Scopus (39) Google Scholar In a larger review of cases, complication rates were minor in 7% and major in 1.1% of cases.7Rundback J.H. Shah P.M. Wong J. Babu S.C. Rozenblit G. Poplausky M.R. Livedo reticularis, rhabdomyolysis, massive intestinal infarction, and death after carbon dioxide arteriography.J Vasc Surg. 1997; 26: 337-340Abstract Full Text Full Text PDF PubMed Scopus (54) Google Scholar The authors briefly described alternate imaging modalities such as intravascular ultrasound (IVUS), but did not include another very valuable way of avoiding contrast, by performing preoperative magnetic resonance angiography (MRA). This MRA can be imported into a system capable of c-arm computed tomography (CT) image acquisition (dynaCT, XperCT). The imported image is thereafter fused with the c-arm CT acquisition and can then serve as a 3D overlay, which can precisely guide the EVAR. Furthermore, it is important to consider that the operative phase is only a small segment of what is a lifetime of imaging for patients with EVAR. In the pre- and postoperative phase, it is imperative that we continue to keep the patients from iodinated contrast exposure and perform studies either with MR (depending on stent), noncontrast CT, or by ultrasound either with or without contrast enhancement. Endovascular aortic aneurysm repair with carbon dioxide-guided angiography in patients with renal insufficiencyJournal of Vascular SurgeryVol. 55Issue 6PreviewRenal dysfunction following endovascular abdominal aortic aneurysm repair (EVAR) remains a significant source of morbidity and mortality. We studied the use of carbon dioxide (CO2) as a non-nephrotoxic contrast agent for EVAR. Full-Text PDF Open Archive

CO2 digital subtraction angiography for renal artery angioplasty in high-risk patients.

The efficacy of CO2 digital subtraction angiography for performing renal artery angioplasty in high-risk patients was evaluated. From January 1997 to July 1998, 21 high-risk patients underwent 29 renal artery angioplasties using carbon dioxide as the principal contrast agent. Six patients had a known allergy to iodinated contrast material and 15 had elevated levels of creatinine. Iodinated contrast material was used only if necessary. All periprocedural allergic reactions were recorded. Before and 24 hr after the procedure, serum creatinine levels were obtained. If the creatinine level had become significantly elevated (>0.5 mg/dl), the creatinine level was acquired a second time. Twenty-one patients (13 men and eight women) underwent 29 angioplasties (two were bilateral and six were repeated). Four kidney transplantation patients had ostial stenosis and the remaining 17 patients had nonostial stenosis. For all patients except one angioplasty initially was a technical success, as defined by a residual stenosis of less than 30%. Supplemental iodinated contrast material was used in only six patients (average dose, 8.5 ml). A range of 80-200 ml of carbon dioxide per procedure was used (average dose, 114.6 ml). One renal artery dissection occurred, which was unrelated to the carbon dioxide. There were no allergic reactions. The level of serum creatinine remained the same after 11 procedures, decreased after 12 procedures, and increased minimally after four procedures (<0.5 mg/dl). On the basis of our preliminary findings in a small group of patients, using carbon dioxide as an intravascular contrast agent to perform renal artery angioplasty in patients who have an allergy to iodinated contrast material or who suffer from renal insufficiency is safe and efficacious.

Carbon Dioxide Digital Subtraction Angiography for Renal Artery Stent Placement

To determine the efficacy of renal artery stent placement with use of carbon dioxide as the primary contrast agent. Seventeen hypertensive patients with renal ostial stenosis were evaluated and underwent stent placement with use of CO2 digital subtraction angiography (DSA). Besides hypertension, 11 patients had decreased renal function, three had iodinated contrast material allergy, one patient had both, and two had neither. Supplemental iodinated contrast material (25 mL or less) was used in five patients. Preprocedure and postprocedure serum creatinine levels were obtained to evaluate the effect of CO2 on renal function. Arteriography was used to evaluate stent positioning. Twenty-three Palmaz stents were placed in 17 patients. Six placements were bilateral, with a total of nine right and 14 left. No additional stents were required to correct malposition. One patient had a mildly significant, yet transient, rise in the postprocedure creatinine level. This patient received 10 mL of iodinated contrast material in addition to CO2. There were no allergic reactions. The utilization of CO2 DSA facilitates the accurate placement of renal artery stents by eliminating the concern for contrast material-associated nephropathy and allergy. These attributes, coupled with the benefit of low viscosity, permit unrestricted imaging, guidance, and precise positioning not afforded by iodinated contrast material.

Densitometric analysis of eccentric vascular stenoses: Comparison of CO 2 and iodinated contrast media

The authors compared the accuracies of CO2 and iodinated contrast material in the densitometric quantification of eccentric vascular stenoses. Five precision-machined eccentric phantom stenoses of 50%, 60%, 70%, 80%, and 90% cross-sectional area narrowing were integrated into a pulsatile ex vivo flow model, imaged with digital subtraction angiography (DSA), and analyzed with densitometry. Relationships between the actual and measured (densitometric) degree of cross-sectional area narrowing were evaluated by using linear regression analysis and paired Student t tests. Comparison measurements were obtained in en face and profile projections. In addition, the effect of iodinated contrast material concentration was evaluated over a range of dilutions (47-282 mg iodine per milliliter). CO2 yielded significantly more accurate results than did iodinated contrast material (282 mg iodine per milliliter) in the 50%, 60%, and 70% stenosis models when imaging was performed en face (P < .005). The best overall correlation was observed with CO2 DSA when imaging in profile (slope = 0.91, intercept = 2.42% actual stenosis, r = .99). The accuracy of densitometric stenosis estimation was inversely related to the concentration of iodinated contrast material. CO2 DSA densitometry, under the conditions of these experiments, yields quantitative measures of relative cross-sectional area narrowing that are comparable with, and under some circumstances surpass, those obtained with iodinated contrast material-based DSA. In this model, CO2 was more useful than iodinated contrast material in 50%-70% stenosis when imaging in the least-optimal plane of stenosis quantification, the en face projection.