Contrast Enhanced Ultrasound can Replace Computed Tomography Angiography for Surveillance After Endovascular Aortic Aneurysm Repair.

OBJECTIVE/BACKGROUND: Surveillance after endovascular aortic aneurysm repair (EVAR) is mandatory and computed tomography angiography (CTA) is considered the standard imaging modality, although patients are exposed to ionizing radiation and nephrotoxic contrast medium. The primary aim of this study was to determine the diagnostic efficacy of duplex ultrasound (DUS) and contrast enhanced ultrasound (CEUS) using CTA as the gold standard. The secondary aim was to determine the clinical consequences of endoleaks missed by DUS and CEUS, or CTA. METHODS: All patients with EVAR for an aorto-iliac aneurysm between 1 August 2011 and 31 October 2014 were prospectively and consecutively enrolled. CEUS was added to the existing surveillance protocol, which included DUS, plain abdominal X-ray, and CTA at 3 and 12 months after stent implantation. RESULTS: In 278 patients, endoleaks were detected in 68, 69, and 46 cases by CTA, CEUS, and DUS, respectively. The sensitivity and specificity of DUS and CEUS were 46% and 93%, and 85% and 95%, respectively. CEUS and CTA were diagnostically equivalent, as opposed to DUS and CTA (p = .002). Endoleaks detected by CTA led to re-intervention in 11 (4%) patients. These endoleaks were also detected by CEUS; however, three out of 11 patients were missed by DUS and underwent re-intervention: limb extension, re-cuff, and attempt to coil lumbar leaks. Endoleaks missed by CEUS or CTA were type II endoleaks without sac expansion. CONCLUSION: In surveillance programs after EVAR a diagnostic CEUS examination may replace CTA.

Endograft limb occlusion in EVAR: iliac tortuosity quantified by three different indices on the basis of preoperative CTA.

OBJECTIVE: To assess the incidence and outcome of graft limb occlusions after endovascular aortic repair (EVAR) of abdominal aortic aneurysm (AAA) in a high volume single centre. To quantify iliac artery tortuosity in patients with AAA and correlate this with limb occlusion. DESIGN: Data were collected consecutively and prospectively, and analyzed retrospectively. MATERIALS: Patients treated with Zenith bifurcated stent grafts from January 2000 to December 2010 at a tertiary referral vascular unit were analyzed. Routine regular office follow-up with computed tomography angiography (CTA) and, subsequently, duplex ultrasound imaging was performed. Patients with limb occlusions were identified. For each index patient, two controls were obtained, one immediately preceding and one following the index patient in the consecutive cohort of EVAR patients. METHODS: Demographics and CTA data on limb graft occlusions were recorded and compared with a defined control group. Three different indices were used to describe the tortuosity of the iliac vessels based on preoperative CTA: pelvic artery index of tortuosity (PAI), common iliac artery index of tortuosity (CAI), and a visual description of vessel tortuosity - the double iliac sign (DIS). Demographic data and indices were correlated for later occurring limb occlusion. RESULTS: 504 patients underwent EVAR and 18 patients experienced graft limb occlusion during a median follow-up of 28 months (range 0-133). Primary graft patency was 97% at 1 year and 96% at 3 years. Logistic regression showed that iliac artery tortuosity (DIS) (p = .001) and body mass index (p = .007) had a significant impact on graft patency. CONCLUSION: A tortuous vessel on the preoperative CTA is associated with an increased risk of limb occlusion after EVAR. Adjunctive stenting of iliac segments deemed at risk is suggested, which is achieved without compromise of the aneurysm repair.

The use of intravascular ultrasound for intraoperative assessment during semiclosed thromboendarterectomy.

To evaluate the application of intravascular ultrasound (IVUS) for intraoperative assessment of semiclosed thromboendarterectomy (TEA), IVUS images of the iliofemoral segment in 20 patients were obtained. The configuration and size of residual atherosclerotic material were evaluated. Stenoses in the artery proximal to the endarterectomized area were measured and, along with any remaining material, related to patency. Patency was evaluated at clinical controls after 3, 6, 12 and 24 months with duplex scanning and ankle-brachial index. In 10 cases (50%), material left behind from the endarterectomy was detected in the artery by IVUS. The material was removed in five cases. The part of the iliac artery proximal to the endarterectomized segment was visualized in 14 cases and showed minor stenoses in 10 cases. After follow-up at a median of 8 months (range 1-24), occlusion had occurred in one of 20 patients and restenosis (> 50%) had developed in two (10%). At this point, patency cannot be related to IVUS findings. We conclude that IVUS is a feasible method for intraoperative assessment of semiclosed TEA. The rate of early failures due to residual material might be reduced by this new application of IVUS.

Quantification of iliac artery stenoses: a methodological comparative study between intravascular ultrasound, arteriography and duplex scanning.

Two morphological methods for quantifying the degree of stenoses in the iliac arteries, intravascular ultrasound (IVUS) and arteriography, were compared with duplex scanning, a method of evaluating the haemodynamic importance of the stenosis. A total of 38 patients, 20 women and 18 men, median age 66 y, admitted for either PTA (n=18) or femoro-femoral crossover bypass surgery (n=20), were examined by IVUS, single plane arteriography and duplex scanning. The predictive value, sensitivity, specificity and kappa value of IVUS were higher than the corresponding values for arteriography. Logistic regression analysis found that IVUS had a predictive value (p=0.0003) for diagnosing significant stenosis as defined by duplex scanning, but arteriography did not (p=0.1). However, this difference in usefulness as predictors did not reach significance. The agreement between arteriography and IVUS was relatively good. The conclusion is that IVUS seems to be superior to single-plane arteriography in predicting hemodynamically significant stenoses as defined by duplex scanning.

[Intravascular ultrasound]. / Intravaskulaer ultralyd.

Intravascular ultrasound (IVUS) is a new imaging modality for the study of cardiovascular disease, which enables us to visualize the structure of the wall and the inner surface of the vessel. The instrument consists of a small very high frequency ultrasound transducer (12.5-40 MHz) mounted on the tip of a catheter, which can be introduced into the vessel. By rotating either the transducer itself or a mirror situated proximal to the transducer, cross-sectional images of the vessel wall with a high resolution are obtained. IVUS can distinguish between the different layers of the vessel and between different kinds of atherosclerotic plaques. Furthermore, the changes created by various interventional procedures may be visualised. These qualities of IVUS begin to comply with the rising demands for a better assessment of the results of the interventions--demands that cannot be fulfilled by arteriography. Moreover, IVUS may contribute to vascular diagnostics without the use of x-ray and contrast media, but is limited by its invasive nature and, until now, high costs.

[Pseudoaneurysm of the femoral artery treated with color Doppler ultrasonography-guided compression]. / Pseudoaneurisme i arteria femoralis behandlet med farve Doppler UL-vejledt kompression.

Conventional treatment of iatrogenic pseudoaneurysms of the femoral artery after puncture during arteriography with or without additional balloon-angioplasty consists of surgical exposure and suture of the defect. The present paper describes colour-Doppler guided compression treatment of 10 femoral pseudoaneurysms. The aneurysm and its connection to the femoral artery is identified by ultrasound-colour-Doppler technique and using the transducer, pressure is applied on the aneurysm such that in- and outflow is stopped without disrupting the blood flow in the underlying femoral artery. In nine cases, where the pseudoaneurysms were less than two weeks old, treatment was successful in all cases. In the remaining patients, the pseudoaneurysm had developed shortly after arteriography and remained constant for one year. In this case, compression did not result in thrombosis. It is concluded that iatrogenic puncture-derived >>young<< pseudoaneurysms of the femoral artery should be treated by colour-Doppler compression except in cases of a rapidly developed large haematoma and circulatory instability. The latter cases should be operated immediately.

[Intravascular ultrasound and percutaneous transluminal angioplasty. Preliminary results]. / Intravaskulaer ultralyd og perkutan transluminal angioplastik. Praeliminaere resultater.

Intravascular ultrasound is a new imaging modality which enables cross-sectional images of blood vessels. These preliminary results of intravascular ultrasound used before and after percutaneous transluminal angioplasty (PTA) in 19 patients, confirm earlier reports of the ability to distinguish between the three different layers of the vessel wall. Atherosclerotic plaques may also be assessed as well as a quantification of the stenosis. After PTA changes in the plaques such as intimal fractures, flaps and dissections could be recognized, and the effect of the intervention could be quantified by measuring the reduction of stenosis and increment of the luminal area. The increased luminal area following PTA was partly due to stretching of the artery and partly due to compression of the atheroma. We found a correlation between the amount of calcium in the plaque and the size of the dissection after PTA. Comparing IVUS with angiography revealed an acceptable agreement in quantifying stenoses before the intervention but not after. We conclude that IVUS is a feasible method to evaluate stenosis in blood vessels before and after PTA. By supplying additional information to angiography, it may improve the selection and outcome after PTA.

[Percutaneous transluminal angioplasty of iliac occlusions]. / Perkutan transluminal angioplastik af iliacaokklusioner.

Percutaneous transluminal angioplasty (PTA) has become an established treatment modality for iliac artery stenosis. PTA of iliac artery occlusions, however, remains a topic of controversy due to difficulties with mechanical recanalization, a lower patency rate and a higher complication rate than obtained after PTA of iliac artery stenosis. During a three year period, we performed 31 PTA's of iliac artery occlusions. The primary recanalization rate was 71% (22 occlusions). Stents were applied in 16 patients. The cumulated patency rates were 95% and 85% after one and six months respectively. There was one late reocclusion after two years. We found a tendency towards inferior patency in the longer occlusions (> or = 5cm). The complication rate was 10% due to three episodes of distal embolisation, all of which were successfully treated immediately with additional PTA and stenting. These results are in accordance with the results of international studies, and suggest that PTA is a useful alternative to surgical treatment of iliac artery occlusions, albeit long occlusions involving both the common and the external iliac artery should be excluded.

Does Dopplersignal enhancement with Levovist improve the diagnostic confidence of duplex scanning of the iliac arteries?--(A pilot study with correlation to intravascular ultrasound).

OBJECTIVE: To evaluate whether echo-enhancement with Levovist improves the diagnostic confidence of duplex scanning of the iliac arteries. METHODS: Sixteen patients admitted for either PTA (n=7) or femoro-femoral cross-over bypass (n=9) were examined with duplex scanning before and after Levovist injection. The diagnostic confidence was noted before and after the echo-enhancement on a visual analog scale. The following day, intraoperatively, an IVUS examination of the iliac artery was performed. The agreement between duplex scanning before and after enhancement compared to IVUS was evaluated by kappa statistics, and sensitivity-specificity calculations. RESULTS: The diagnostic confidence improved in 50% of the patients, remained unchanged in 44%, and deteriorated in one (6%) patient. The agreement with IVUS was moderate before enhancement (kappa=0.48) and good after the enhancement (kappa=0.63). Sensitivity rose from 64% (before) to 73% (after) Levovist while the specificity was unchanged (100%). These values are not as good as reported by others after fasting of the patients and comparing the results with arteriography. CONCLUSION: Levovist improves the diagnostic confidence of duplex scanning, but marginally. In inconclusive duplex scannings echo-enhancement can supply decisive informations.

The clinical importance and prediction of steal following femoro-femoral cross-over bypass: study of the donor iliac artery by intravascular ultrasound, arteriography, duplex scanning and pressure measurements.

OBJECTIVES: to evaluate the clinical significance of the steal phenomenon following femoro-femoral bypass, and whether the addition of intravascular ultrasound (IVUS) to the established examinations of the donor iliac artery can improve the prediction of patients who will develop steal. DESIGN: prospective study. MATERIAL AND METHODS: twenty-eight patients, aged 73 (50-81) years, scheduled for femoro-femoral bypass surgery in the period from 1994 to 1997, had the donor iliac artery examined by single-plane arteriography, duplex scanning, IVUS and femoral-artery blood pressure measurements (FABP)+/-papaverine. Three patients were excluded due to simultaneous thromboendarterectomy (TEA) of the donor iliac artery. The clinical stage and the ankle-brachial index (ABPI) were measured pre-, postoperatively and prospectively 1, 6, 12 and 24 months after discharge. RESULTS: two patients developed clinical steal, while an additional five had a measurable (>0.1) decline in the donor ABPI postoperatively, but no symptoms (subclinical steal). The clinical stage of the donor limb did not deteriorate further during the follow-up period (median 8 months) in these seven patients. The decline in donor ABPI correlated with the FABP and the IVUS measurements, but not to duplex scanning or arteriography. FABP after papaverine injection and IVUS examination showed equal sensitivities and and specificities. CONCLUSION: a clinical steal phenomenon following femoro-femoral bypass surgery seems relatively uncommon, although a subclinical steal is more frequent. Both can be predicted by FABP or IVUS. Further follow-up is required to evaluate whether subclinical steal has any consequences in the long term.

Prediction of outcome after femoropopliteal balloon angioplasty by intravascular ultrasound.

OBJECTIVE: To evaluate intravascular ultrasound (IVUS) as a control procedure after femoropopliteal percutaneous transluminal angioplasty (PTA), and compare it with arteriography. DESIGN: Descriptive study. MATERIAL: Arteriographic and intravascular ultrasound data obtained from 18 patients (20 limbs) undergoing PTA of the superficial femoral or popliteal artery. The degree of stenosis, the diameter and area of the lumen and the morphological changes in the plaque were related to the short-term patency of the intervention, as evaluated by duplex scan and ankle branchial index. RESULTS: Fifteen arteries remained patent. Two occlusions and two stenoses developed during the first 3 months after the intervention and one occlusion occurred after 1 year. The following IVUS parameters were related to a favourable patency: presence of calcification; dissection or plaque rupture and residual stenosis of less than 70%. The arteriographically determined diameter reduction did not show predictive value. CONCLUSION: This study shows that in contrast to arteriography, IVUS revealed parameters predictive for patency following PTA.

Near-infrared spectroscopy during peripheral vascular surgery.

Near-infrared spectroscopy was performed perioperatively on the dorsum of the foot in 14 patients who underwent infrainguinal bypass surgery using a prosthesis or the greater saphenous vein. Dual-wavelength continuous light spectroscopy was used to assess changes in tissue saturation before, during and after the operation. Following the use of peripheral vascular grafts an immediate postoperative increase in tissue saturation of median 28 (range -10 to +81) arbitrary units was noted (P < 0.01). Following distal clamping of the common femoral artery, maximal ischaemia corresponding to a median reduction in tissue saturation of 61 (range 6-94) units was reached after 26 (range 8-95) min (P < 0.01). The maximal tissue saturation following declamping was median 27 (range -16 to +100) units higher than the preoperative level (P < 0.01) and was reached after median 42 (range 8-125) min. The results indicate that near-infrared spectroscopy is appropriate for perioperative monitoring during vascular grafting.

The use of intravascular ultrasound as control procedure for the deployment of endovascular stented grafts.

OBJECTIVE: To assess whether intravascular ultrasound (IVUS), used systematically in a series of patients with abdominal aortic aneurysms (AAA), is a feasible control procedure to ensure correct transfemoral placement of endovascular stent grafts (TPEG). DESIGN: Descriptive study. MATERIALS AND METHODS: Fourteen patients with infrarenal aortic aneurysms were treated by the placement of one tube graft, 10 aorto-uni-iliac and three aorto-bi-iliac grafts. Arteriography and IVUS were performed before, during and after deployment of the graft to ensure correct placement in relation to side branches, and proper adaptation of the stents to the aortic wall. Postoperative CT-scan and arteriography served as control procedures. RESULTS: IVUS identified both renal arteries before graft deployment in eight of 13 (62%) patients. In the remaining patients only one renal artery was visualised due to interference from guidewires or the introducer system. Imaging during stent deployment was abandoned after IVUS catheter damage in two of three cases. Postprocedural IVUS was able to evaluate the expansion of the stents and the adaptation to the aortic wall in all instances. In four (29%) cases a leak was identified. Additional intervention included deployment of a further stent (n = 2) or redilation (n = 2). Covering of the renal arteries could only be indirectly determined by IVUS. CONCLUSION: IVUS can provide important decisive information before and after stented graft deployment, with the limitations that guidewires, introducer system and stents may cause interference. Contemporary IVUS designs are unsuitable for monitoring stent deployment.

Primary gastrointestinal non-Hodgkin's lymphoma in adults: a population-based clinical and histopathologic study.

OBJECTIVES: To analyse the clinical course and the histopathology of primary gastrointestinal non-Hodgkin's lymphoma (GI-NHL) in adult patients and to investigate a possible impact of Helicobacter pylori. DESIGN/SETTING: Retrospective study of all adult patients in Copenhagen county diagnosed during a 6-year period with NHL. SUBJECTS: A total of 55 patients with GI-NHL diagnosed during the period from 1985 to the end of 1990. RESULTS: Twenty-eight patients had primary lymphoma in the stomach, 14 in the small intestine, 11 in the large intestine and two patients had multifocal involvement. The dominant presenting symptoms were abdominal pain, weight loss, diarrhoea, constipation and fatigue. Acute emergency problems such as severe haemorrhage or perforation at initial presentation were unusual. According to the revised European-American lymphoma (REAL) classification, diffuse large B-cell lymphoma was the most frequent histologic subtype comprising 53% of the cases. Helicobacter pylori infection was documented in 15 of 25 evaluable patients (60%) with gastric lymphomas and was not associated with any specific histological subtype. Endoscopic procedures and barium X-rays were the diagnostic approaches with highest sensitivity. In total, 30 patients (58%) achieved complete remission, 10 (19%) achieved partial remission, and 12 (23%) did not respond to treatment. The overall 5 year survival rate was 0.36 without statistically significant difference between the histological subtypes. Likewise the presence of Helicobacter pylori did not affect survival. CONCLUSION: Primary GI-NHL is a heterogeneous disease entity with considerable therapeutic controversies. No specific clinical or histological phenotype was associated with the presence of Helicobacter pylori.