Journal of Vascular Surgery
Volume 33, Issue 3 , Pages 646-649, March 2001

Carbon dioxide angiography for endovascular grafting in high-risk patients with infrarenal abdominal aortic aneurysms☆☆☆

Heidelburg, Germany

From the Department of Surgery, Division for Vascular Surgery,a and the Department of Radiology,b Ruprecht-Karls University of Heidelberg

Received 28 February 2000; accepted 21 August 2000.

Article Outline

Abstract 

Allergic reactions to contrast media, preexisting renal dysfunction, and hyperthyroidism are relative contraindications for angiography with conventional contrast medium. Carbon dioxide (CO2) angiography is an alternative method in high-risk patients because CO2 is nontoxic, without allergic potential, and not iodic. CO2-related complications are extremely rare. Because renal insufficiency often occurs in vascular patients, this method will become increasingly important for endovascular surgery. We report on three consecutive patients with asymptomatic infrarenal aortic aneurysm and concomitant renal dysfunction or allergic reactions to standard contrast media. Aortic stent grafts were deployed under CO2 angiographic control without complications or worsening of renal function. (J Vasc Surg 2001;33:646-9.)

 

Compared with iodinated contrast media, carbon dioxide (CO2) angiography has some remarkable advantages: the gas is not toxic, it has no allergic potential, and it is not ionic. In addition, it is inexpensive and easily available. In patients with abdominal aortic aneurysm (AAA) and preexisting renal failure who are candidates for endovascular surgery, which is associated with a considerable amount of contrast material, angiography may be performed with CO2 as a contrast agent to prevent major acute renal dysfunction and dialysis.1, 2, 3 When allergic reactions to conventional contrast media are known and preexisting hyperthyroidism is also a factor, CO2 might also be used as a contrast material, instead of intensive medical pretreatment.3

We report on three high-risk patients (ASA III) with infrarenal AAAs who required therapy to prevent rupture. In all cases, an AAA morphology suitable for endovascular exclusion was confirmed by means of a preoperative evaluation.4 Although CO2 angiography is proven to be safe in combination with vascular interventions, to our knowledge there are no data available about CO2-assisted aortic stent graft placement.5

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Methods 

Intraoperative CO2 angiography was performed with an automatic gas administration set (CO2JECT, Medex Medical, Klein-Winternheim, Germany) to ensure reproducible gas volume flow in all cases. All CO2-assisted angiographic procedures were done with an 80 mL/s gas flow rate and 100 mL gas volume. Preoperative AAA evaluation, morphologic classification, and postoperative controls were performed by means of magnetic resonance angiography (MRA) imaging.

All procedures were performed in an interventional operating room with a state-of-the-art angiography unit (Philips Integris V 5000; Philips Medizin Systems, Hamburg, Germany). CO2 serves as a negative contrast medium. Although CO2 angiography can be performed on a standard fluoroscopy unit, the results are considerably improved by special acquisition and postprocessing software, which is standard for all major types of angiography units.

CO2 was administered with a dedicated power injector, which allows controlled injection of the gas at constant and reproducible flow rates and volumes. A integrated constant saline drip avoided intermittent contamination with room air and air embolism. The gas line to the angiography catheter and the catheter itself were automatically flushed before the diagnostic injection, thus avoiding uncontrollable explosive liberation of CO2. Finally, the injection was electrocardiogram gated, providing a homogeneous arterial contrast in the low-flow diastole. Most of these features cannot be achieved by means of manual injection devices such as bags and syringes, which are known to have a high risk of room air contamination.

The CO2JECT Injector Model is available for DM 65,000 (DM 65,000 is approximately US $32,000). In addition, the mandatory special CO2 catheter set (CO2 Connect, Medex Medical) must be purchased for DM 130. The costs are comparable with those of conventional catheter material.

On the basis of collected morphometric data, an AAA classification with possible graft configuration was described earlier.4 All the cases presented were classified on the basis of this classification system.

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Case 1 

A 47-year-old man with an asymptomatic infrarenal AAA (type IIb) with a maximum diameter of 5 cm (Fig 1)4, 6 had polycystic kidneys (autosomal-dominant disease) and resulting renal dysfunction, although the disease was stable (Fig 1).

His AAA was first diagnosed during routine abdominal ultrasonography for his huge polycystic kidneys. After preoperative morphologic evaluation for transluminal endovascular placed graft (TPEG), the patient underwent general anesthesia, and the TPEG was placed and controlled by means of CO2 angiography (Excluder Bifurcation stent; W.L. Gore, Flagstaff, Ariz; Fig 2). The preoperative creatinine level was compensated at 2.5 mg/dL and remained unchanged during and after the procedure. There were no notable adverse effects. The procedure had no complications. No primary leakage could be observed in the CO2-assisted angiography after correct placement. A correctly placed bifurcation stent starting exactly below the renal arteries was shown by means of postoperative gadolinium-enhanced MRA (Fig 3).

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Case 2 

An asymptomatic infrarenal AAA with a maximum diameter of 7.5 cm, starting 2 cm distal to the renal arteries, was revealed by means of routine abdominal ultrasonography in a 69-year-old man.4, 6 The common iliac arteries reached normal sizes 3 cm proximal to the iliac bifurcation on both sides. The patient had had a severe allergic reaction to conventional contrast medium during previous peripheral angiography and a coexisting renal dysfunction in a compensated status (creatinine level, 1.4 mg/dL; urea level, 43 mg/dL). Therefore, preoperative evaluation for a TPEG was performed by means of MRA. The infrarenal AAA was classified as type IIb, according to the Allenberg classification, with an adequate proximal neck and distal anchoring in the common iliacs (Fig 4).4, 6

  • View full-size image.
  • Fig. 4. 

    Morphometric AAA definitions and possible graft configurations. Type I, proximal neck > 15 mm and distal cuff > 10 mm (tubular endograft); type IIA, proximal neck > 15 mm and AAA down to aortic bifurcation (bifurcated endograft); type IIB, proximal neck > 15 mm and aneurysmal involvement of the proximal common iliac arteries (bifurcated endograft); type IIC, proximal neck > 15 mm and AAA down to the iliac bifurcation (open surgery); type III, proximal neck > 15 mm and distal AAA expansion (open surgery).6

Other risk factors were diabetes mellitus (type IIb), hypertension, and obesity.

After preoperative evaluation for TPEG, the patient underwent general anesthesia, and the TPEG (Vanguard Bifurcation stent; (Boston Scientific Corp, Oakland, NJ) was placed and controlled by means of CO2 angiography. Preoperative creatinine and urea levels remained unchanged during and after the procedure. There were no notable adverse effects. The procedure was performed without any notable complications. TPEG could be accurately placed just below the renal arteries down to the iliac bifurcation. No primary leakage could be visualized by means of the CO2-assisted completion angiography, which was confirmed by means of MRA after 2 days.

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Case 3 

A 75-year-old man had an asymptomatic infrarenal AAA (type IIa)4, 6 with a maximum diameter of 6 cm. The proximal aortic neck was shown to be suitable for endovascular stent graft placement (2.5 cm below renal arteries) by means of preoperative magnetic resonance imaging (MRI). The AAA ended at the level of aortic bifurcation, and the renal arteries showed no stenosis by means of the MRI. The known risk factors were hypertension and type 1 diabetes mellitus. Diabetes mellitus was first diagnosed in the patient 5 years earlier, and he had diabetes-related renal dysfunction and stable disease. The preoperative creatinine level was stable at 3.0 mg/dL, and the urea level was 82 mg/dL. The TPEG (Vanguard bifurcation stent; Boston Scientific Corp) was placed without changing the renal function, and the preoperative creatinine level remained unchanged during and after the procedure.

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Discussion 

There is a high risk of renal failure after angiography with iodinated contrast medium, especially in patients with preexisting renal dysfunction. However, there is a significantly higher comorbidity for renal dysfunction in vascular patients because of the higher number who have diabetes mellitus and renovascular arteriosclerosis. Hernandez-Richter et al2 demonstrated that diabetes mellitus is an established risk factor (8.7%) in vascular and AAA patients.

Martin-Paredero et al1 described acute renal dysfunction (ARD) in 11.3% of patients who underwent abdominal and runoff angiography (n = 400). Of the group of patients with normal renal function before the procedure, 8.2% had ARD. However, only 0.8% of patients required dialysis after angiography with iodinated contrast material. Patients with earlier abnormal renal function had a 41.7% incidence of ARD, and 8.3% of them required dialysis as a result of angiography. For patients with known severe allergic reactions, severe renal dysfunction, or both, the last two statements have to be taken into consideration when deciding on the interventional treatment of AAA, because a high amount of contrast material is required for TPEG placement.

Allergic reactions may occur in as many as 10% of patients after angiography with iodine contrast material. However, severe allergic reactions requiring therapy were only observed in 2.2% of patients. When allergic reactions to iodinated contrast material is a known factor, pretreatment with corticosteroids and antihistamine medication is mandatory so that the risk of severe reactions is minimized.3 Severe allergic reactions in patients not known to have a predisposition for such reactions are very rare.

In addition to its allergic potential and capacity for causing renal function impairment, the application of contrast material in patients with chronic or acute heart failure or unknown hyperthyroidism can be critical, so pretreatment or posttreatment is required. Therefore, the negative contrast material CO2 can be used as a good alternative, because it has some remarkable advantages in selected cases, such as those presented. However, its use requires a special gas application system for adequate gas flow and volume control. A special postprocessing software for the angiography machines improves the fluoroscopy results significantly and is standard in all major angiography units. One case was published in which a CO2-related death occurred after aortography after gas injection by hand.7 In patients with AAA and preexisting renal failure, it seems reasonable to perform angiography with CO2 as a contrast agent to prevent major acute renal dysfunction and dialysis. A combination of CO2 and conventional contrast material for major angiographies may reduce the amount of conventional contrast material required. However, the presented cases were performed without any additional iodinated contrast medium.

When the patient has known severe allergic reactions to conventional contrast media and hyperthyroidism, it is advisable to use CO2 angiography instead of intensive medical pretreatment. CO2 digital subtraction angiography is already established in the evaluation of renal arteries, the imaging of renal allograft dysfunction, and the follow-up of renal artery bypass grafts.8, 9, 10, 11, 12 CO2 has been shown to be a safe contrast agent for vascular imaging in patients with impaired renal function who require definitive vascular imaging or therapy.8

Aortic stent graft placement for infrarenal AAA has been safe, easy to perform, and without complications. In particular, there have been no negative effects on preexisting renal insufficiency, as in our cases. In our patients, the adverse effects described in the literature, such as abdominal pain, nausea, and vomiting, were not noted.13

Reduced contrast is a known disadvantage of CO2 angiography, but this can be improved significantly with special postprocessing imaging software and continuous gas flow. Hand application techniques (syringes, bags) can lead to inhomogeneous, unreproducible gas flow, resulting in a reduction in the image quality and bearing the risk of invisible room air contamination. Therefore, we recommend automatic CO2 application to avoid these problems. The reduction in image contrast compared with conventional angiography with iodinated contrast material did not have an influence on accurate stent placement in our cases.

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Conclusion 

CO2 angiography is a good alternative in vascular patients with contraindications for ionic iodinated contrast material (eg, renal insufficiency, allergic reactions, and hyperthyroidism). Because renal insufficiency often occurs in vascular patients and the increased number of endovascular procedures, CO2 angiography may play a major role in the future. Despite the reduced contrast enhancement compared with iodine contrast mediums, CO2 angiography is a safe method for aortic stent graft placement. CO2 should be applied by an automatic gas administration set to ensure reproducible gas-volume flow.

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References 

  1. Martin-Paredero V, Dixon SM, Baker D, Takiff H, Gomes AS, Busuttil RW, et al.  Risk of renal failure after major angiography. Arch Surg. 1983;118:1417–1420
  2. Hernandez-Richter T, Schardey HM, Klueppelberg U, Tutsch-Bauer E, Lauterjung L, Schildberg FW. Ist ein heterogener Alpha-1-Antitrypsinmangel ein risikofaktor in der ätiologie des aortenaneurysmas?. Chirurg. 1997;68:513–516
  3. Lasser EC, Berry CC, Talner LB, Santini LC, Lang E, Gerber FH, et al.  Pretreatment with corticosteroids to alleviate reactions to intravenous contrast material. N Engl J Med. 1987;317:845–849
  4. Allenberg JR, Schumacher H, Robbie P. Computer-assisted evaluation of aortic aneurysm morphology for choosing the method of therapy. Langenbecks Arch Chir Suppl Kongressbd. 1998;115:105–107
  5. Kummer-Kloes D, Kloes W, Marienhoff N, Schütz M, Zwaan M, Weiss HD. Interventionsbegeitende angiographie mit kohlendioxid (CO2) (Carbonangiographie) bei patienten mit erhöhtem kontrastmittelrisiko. Zentralbl Chir. 1997;122:725–729
  6. Schumacher H, Eckstein HH, Kallinowski F, Allenberg JR. Morphometry and classification in abdominal aortic aneurysms. J Endovasc Surg. 1997;4:39–44
  7. Rundback HJ, Shah PM, Wong J, Babu SC, Rozenblit G, Poplausky MR. Livedo reticularis, rhabdomyolosis, massive intestinal infarction, and death after carbon dioxide arteriography. J Vasc Surg. 1997;26:337–340
  8. Kuo PC, Petersen J, Semba C, Alfrey E, Dafoe D. CO2 angiography—a technique for vascular imaging in renal allograft dysfunction. Transplantation. 1996;61:652–654
  9. Harward TRS, Smith S, Hawkins IF, Seeger JM. Follow-up evaluation after renal artery bypass surgery with use of carbon dioxide arteriography and color-flow duplex scanning. J Vasc Surg. 1993;18:23–30
  10. Schreier DZ, Weaver FA, Frankhouse J, Papanicolaou G, Shore E, Yellin E, et al.  A prospective study of carbon dioxide-digital subtraction vs standard contrast arteriography in the evaluation of renal arteries. Arch Surg. 1996;131:503–508
  11. Hawkins IF, Mladinich CR, Storm B, Croker BP, Wilcox CS, Akins EW, et al.  Short-term effects of selective renal arterial carbon dioxide administration on the dog kidney. J Vasc Interv Radiol. 1994;5:149–154
  12. Hawkins IF, Wilcox CS, Kerns SR, Sabatelli FW. CO2 digital angiography: a safer contrast agent for renal vascular imaging?. Am J Kidney Dis. 1994;24:685–694
  13. Caridi JG, Hawkins IF. CO2 digital subtraction angiography: potential complications and their prevention. J Vasc Interv Radiol. 1997;8:383–391

☆ Competition of interest: nil.

☆☆ Reprint requests: Dr Johannes Gahlen, Chirurgische Universitätsklinik Heidelberg, Kirschnerstraße 1, D-69120 Heidelberg, Germany (e-mail: johannes_gahlen@med.uni-heidelberg.de ).

PII: S0741-5214(01)89325-3

doi:10.1067/mva.2001.111746

Journal of Vascular Surgery
Volume 33, Issue 3 , Pages 646-649, March 2001

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