Geoffrey A. Gardiner

Salvage of occluded arterial bypass grafts by means of thrombolysis

Seventy-two thrombosed peripheral arterial bypass grafts in 62 patients were treated by local intraarterial thrombolytic infusion. The initial success rate was 69% (50 of 72 grafts). Graft material and location had no significant effect on the initial results. Urokinase was used in 43 cases with a 84% success rate, and streptokinase was used in 29 cases with a 48% success rate. After a follow-up period that ranged from 2 to 58 months, 27 grafts remained patent, with an average patency duration of 15 months (median 8 months). Overall graft patency at the end of 1 year was 60% applying life-table analysis. Factors that were evaluated to determine their effect on long-term patency included graft age and material, graft location, and the presence or absence of an underlying correctable lesion. The most significant factor in long-term patency was the presence of a lesion that was correctable by surgical revision or balloon angioplasty. In 25 grafts with underlying stenotic lesions, the 1-year patency was 86% after successful treatment. Twenty-five grafts without detectable lesions had 37% 1-year patency.

Venography with carbon dioxide as a contrast agent

PurposeThe purpose of this study was to evaluate the feasibility, safety, and potential role of carbon dioxide (CO2) as a contrast agent for venography.MethodsConsecutive patients with contraindications to iodinated contrast agents or with unsatisfactory iodinated contrast studies underwent CO2 digital subtraction venography. The images were rated by three experienced angiographers. Image quality and complications were assessed.ResultsOver a 14-month period, 66 vein segments were studied in 21 patients. There was good correlation between experienced angiographers on CO2 image quality (Ri = 0.80) and good agreement on diagnosis (k = 0.62). In 91% of the vein segments evaluated with CO2 there was interobserver agreement on the diagnosis. Upper extremity veins were adequately imaged with CO2 alone in all (6/6) patients with contraindications to iodinated contrast. Following suboptimal iodinated contrast studies in six patients, CO2 produced significantly better quality upper extremity central vein images (p < 0.05). Pain following injection into peripheral veins was the only CO2-related complication. Inferior vena cava (IVC) filters were successfully deployed with CO2 alone in 78% (7/9) of patients; two required iodinated contrast.ConclusionBased upon initial experience, CO2 venography can be recommended in patients with contraindications to iodinated contrast or unsatisfactory iodinated contrast studies.

Vascular applications of laser

The authors review the current experimental and clinical literature relating to the use of lasers in peripheral vascular disease. During the past few years, significant strides have been made in effective harnessing of laser energy for percutaneous revascularization. However, the role of lasers in treating vascular disease is not yet clear. Thus current application of laser technology in this area should be considered experimental until adequate clinical studies confirm its efficacy.

Osteochondroma: An Unusual Cause of Vascular Disease in Young Adults

Vascular complications such as pseudoaneurysm, arterial thrombosis, luminal stenosis due to extrinsic compression, deep venous thrombosis, and arteriovenous fistula are known complications of osteochondroma. The authors describe three cases of vascular injury caused by osteochondroma: popliteal artery impingement, popliteal artery pseudoaneurysm formation, and superficial femoral artery pseudoaneurysm with peripheral occlusion of the tibial and peroneal arteries due to embolization. Fifty-six cases of vascular complications due to osteochondroma from the English literature are also reviewed. This entity should be considered in young patients with evidence of peripheral vascular insufficiency or in patients with known osteochondroma who develop symptoms of local pain and swelling in the involved extremity.

US, CT, and MR evaluation of accessory renal arteries and proximal renal arterial branches*

RATIONALE AND OBJECTIVES The purpose of this study was to compare color Doppler ultrasound (US), computed tomographic (CT) angiography, and magnetic resonance (MR) angiography for the evaluation of accessory renal arteries and proximal branches of the main renal artery. MATERIALS AND METHODS Fifty-six subjects who had undergone conventional arteriography of the renal arteries participated in a prospective comparison of Doppler US (45 patients), CT angiography (52 patients), and nonenhanced MR angiography (28 patients). Conventional arteriography depicted 28 accessory renal arteries and 21 proximal branches of the main renal artery within 2 cm of the aorta. RESULTS US depicted five of 24 accessory renal arteries seen at arteriography but no proximal arterial branches. CT angiography depicted 24 of 26 accessory renal arteries and 13 of 17 proximal arterial branches, as well as 15 additional accessory renal arteries not seen at conventional arteriography. MR demonstrated 11 of 15 accessory arteries, as well as four additional accessory arteries not seen at conventional arteriography. MR did not depict any of nine proximal arterial branches seen at conventional arteriography. CONCLUSION When compared with US or nonenhanced MR angiography, CT is the preferred method for evaluation of accessory renal arteries and proximal branches of the renal artery.

Comparison of Doppler US and CT angiography for evaluation of renal artery stenosis

Rationale and Objectives. The authors compared Doppler ultrasound (US) with computed tomographic (CT) angiography in the evaluation of stenosis of the main renal artery. Materials and Methods. Fifty-six patients who had undergone conventional angiography of the renal arteries participated in a prospective comparison of Doppler US (45 patients) and CT angiography (52 patients). US evaluation included both the main renal artery and segmental renal arteries. Results. There were 27 main renal arteries with at least 50% stenosis in 20 patients. In 36 patients, there was no significant stenosis. All cases of main renal artery stenosis detected with Doppler US of the segmental arteries were also identified with Doppler US of the main renal artery. The by-artery sensitivity (63%) of US of the main renal artery was greater than that (33%) of US of the segmental arteries. CT angiography was more sensitive (96%) than Doppler US (63%) in the detection of stenosis, but the specificity of CT (88%) was similar to that of US (89%). The difference in the area under the receiver operating characteristic curve (AUC) between CT (AUC = 0.94) and US (AUC = 0.82) was statistically significant (P = .038). Conclusion. Doppler US of the main renal artery is more sensitive than Doppler US of segmental arteries in the detection of stenosis. CT angiography is more accurate than Doppler US in the evaluation of renal artery stenosis.

Intravascular Ultrasound as an Alternative to Positive-contrast Vena Cavography prior to Filter Placement

PURPOSE In a nonconsecutive series of patients, intravascular ultrasound (IVUS) was investigated for safety and efficacy as an alternative to positive-contrast vena cavography for evaluating the inferior vena cava (IVC) prior to filter placement. MATERIALS AND METHODS In a 6.5-year period, 30 patients (15 women, 15 men) ranging in age from 22 to 98 years old (mean, 56 years) underwent vena cava filter placement without conventional positive-contrast vena cavography, after IVUS evaluation of the IVC with use of a 6.2-F, 12.5- or 20-MHz monorail catheter system. The rationale for using IVUS included contraindications to iodinated contrast material in 14 patients with renal insufficiency and in four patients with previous life-threatening anaphylactoid reaction to iodinated contrast material; limitations to radiation exposure in four pregnant patients; and inability to otherwise image the IVC of eight morbidly obese patients who exceeded the weight limits of available angiographic equipment. IVUS completely replaced positive-contrast vena cavography, although not fluoroscopy in the four pregnant patients and in the 18 patients with contrast material contraindications. In two of the eight obese patients, IVUS was the only imaging modality. RESULTS In all 30 patients, IVUS successfully determined the patency of the filter delivery route veins and the vena cava, the absence of thrombus, the location of renal veins, the absence of anatomical variants, and the vena cava diameter at the desired filter deployment level. Successful filter placement was confirmed in all 30 patients either with plain film alone (n = 12), IVUS alone (n = 3), computed tomography alone (n = 1), external ultrasound alone (n = 1), IVUS and another imaging modality (n = 10), or by combinations of other imaging modalities (n = 3). There were no complications. CONCLUSIONS IVUS is a safe and effective alternative to conventional positive-contrast vena cavography for imaging the IVC prior to filter placement in patients with contraindications to iodinated contrast material or ionizing radiation.

Intraarterial Chemotherapy with Limb-sparing Resection of Large Soft-Tissue Sarcomas of the Extremities

Fifteen patients with large (average, 15-cm), high-grade soft-tissue sarcomas of the extremities received prolonged selective intraarterial infusions of chemotherapeutic agents in an attempt to permit limb-sparing resection of these tumors, which would otherwise have required amputation. There were seven malignant fibrous histiocytomas, four liposarcomas, two fibrosarcomas, one leiomyosarcoma, and one rhabdomyosarcoma; 73% were grade III. Seven patients underwent two catheterizations, for a total of 22 infusions, which averaged 11.3 days each. There were four catheterization-related complications, including catheter occlusion or dislodgement in one patient each and two cases of arterial thromboembolism in patients in whom anticoagulant dose was not adequate. Both of the latter patients required thrombectomy; one developed gangrene, which precluded limb-sparing surgery. Thirteen of the 15 patients underwent limb-sparing resections, and two underwent amputations. No wound complications occurred. With a median follow-up of 36 months (mean, 34 months), life-table analysis indicates overall and disease-free survivals of 72% and 59%, respectively, at 2 years and 64% and 59% at 3 years. In comparison to other reported therapies, this technique permits limb salvage in most patients without the high wound complication rate associated with preoperative radiation therapy, with equivalent local disease control and survival.

Feasibility of three-dimensional intravascular ultrasonography: preliminary clinical studies.

The aim of this study was to demonstrate the clinical utility of reconstructed three‐dimensional intravascular ultrasonography using a voxel‐based volume rendering technique. Three‐dimensional reconstruction of intravascular ultrasonographic data was performed in 12 patients with various vascular abnormalities during interventional radiology procedures. A stepping motor device was used to pull either a 12.5 or a 20 MHz catheter‐based transducer through the lumen of a variety of vessels at a rate of 1.5 mm/s. Images were downloaded to a Life Imaging System for three‐dimensional reconstruction. The value of three‐dimensional ultrasonographic imaging was evaluated in comparison to conventional intravascular ultrasonography. A variety of abnormalities were demonstrated in reconstructed three‐dimensional ultrasound imaging, including arterial atheroma and plaque, aneurysm and pseudoaneurysm, aortic dissection and stenosis (May‐Thurner syndrome). The vascular branches and accessory vessels, as well as their relationships to each other, were easily demonstrated on three‐dimensional imaging by selecting an appropriate angle, plane, and section of the image. The dimensions and shapes of the vascular lumen were determined in the longitudinal view. Three‐dimensional information proved useful for determining the distribution and type of plaque in vessels. Reconstructed three‐dimensional imaging allows for global evaluation of the dissection entry site, extent of the flap, and the false lumen of a pseudoaneurysm. Intravascular three‐dimensional ultrasonography provides information complementary to that obtained with two‐dimensional imaging. It supplies information about spatial relationships of anatomic structures that cannot be evaluated using conventional imaging methods.

Quantification of Elastic Recoil after Balloon Angioplasty in the Iliac Arteries

PURPOSE Elastic recoil of the arterial wall has been shown to be responsible for a significant loss of luminal area after balloon angioplasty in the coronary arteries, but it has not been well studied in the peripheral arteries. Because elastic recoil depends on the presence of elastin in the arterial wall, and the amount of elastin varies by artery and proximity to the aorta, the importance of this response to angioplasty may be different in peripheral arteries. The purpose of this study is to document the degree of elastic recoil in the iliac arteries, and analyze variables that might influence the results. MATERIALS AND METHODS A series of 19 patients with 25 iliac artery stenoses underwent balloon angioplasty followed by placement of a Palmaz stent with the same-sized angioplasty balloon. The minimum luminal diameter of the lesion was measured before treatment, immediately after balloon angioplasty, and again after stent placement. The arterial diameter after stent placement was defined as the diameter of the inflated balloon. The degree of recoil was correlated with nine variables: patient age and sex, lesion location and length, lesion severity (as percent stenosis), the balloon:artery ratio, and three factors related to lesion morphology--complex versus simple, eccentric versus concentric, and calcified versus noncalcified. RESULTS Elastic recoil averaged 36% +/- 11% and ranged from 19% to 54% in this series of patients. The only variable that significantly influenced the degree of elastic recoil was the balloon:artery ratio (P =.039), which was directly related. CONCLUSION Elastic recoil is a significant limitation of balloon angioplasty in the iliac arteries. This study illustrates the importance of techniques that limit recoil, such as vascular stents, in angioplasty of the iliac arteries.