Follow-up on Small Abdominal Aortic Aneurysms Using Three Dimensional Ultrasound: Volume Versus Diameter.

OBJECTIVES: Rupture risk in abdominal aortic aneurysms (AAAs) is assessed using AAA diameter; yet 10% of ruptures occur in a small aneurysm. This underlines the inadequacy of diameter as a standalone parameter. In this prospective follow-up study, ultrasound determined aneurysm diameter was compared with aneurysm volume determined by three dimensional ultrasound (3D-US) in a group of 179 AAAs. DESIGN: This was a prospective cohort study with repeated diameter and volume measurements by 3D-US. MATERIAL AND METHODS: In total, 179 patients with small infrarenal AAAs (diameter 30-55 mm) were enrolled consecutively. At enrolment and at 12 month follow-up, maximum diameter, using dual plane technique, and three dimensional volume were measured. Based on a previous accuracy study, significant change in diameter and volume were defined as an increase exceeding the known range of variability (ROV) of each US technique; ±3.7 mm and ±8.8 mL, respectively. Post-hoc Kaplan-Meier analysis was performed to estimate time to conversion to treatment after the conclusion of the follow-up period between two groups. RESULTS: In total, 125 patients (70%) had an unchanged diameter during follow-up. In this group, 50 patients (40%) had an increasing aortic volume. Forty-five (83%) of the 54 patients with an increasing aortic diameter showed a corresponding volume increase. During a median follow-up of 367 days (364-380 days), a mean increase in diameter of 2.7 mm (±2.6 mm) and a mean increase in volume of 11.6 mL (±9.9 mL) were recorded. In post-hoc analysis, it was found that more AAAs with a stable diameter and a growing volume than AAAs with a stable diameter and volume were undergoing aortic repair during follow-up, based on the maximum diameter. CONCLUSION: In this cohort of small AAAs, 40% of patients with a stable diameter had an increasing volume at 12 month follow-up. From this perspective, 3D-US could have a future supplemental role in AAA surveillance programmes.

The haemodynamic effect of carotid endarterectomy.

OBJECTIVES: to assess the haemodynamic effect of carotid artery surgery, and to relate postoperative changes to the state of cerebral circulation before revascularisation. MATERIALS AND METHODS: using transcranial Doppler we studied bilateral middle cerebral artery (MCA) flow velocities before and on 1st day, 2nd or 3rd day and 4th or 5th day and 3 months after carotid surgery in 61 patients. In addition, ipsilateral MCA flow velocity was monitored continuously during surgery. Data were related to the internal carotid artery (ICA) perfusion pressure (cerebral perfusion pressure index, CPPI), measured directly before ICA clamping. RESULTS: postoperatively, MCA flow velocities increased significantly overall (p<0.01), mainly due to pronounced and longer lasting flow velocities in the group of 18 patients with CPPI<0.7 (p<0.05). Flow velocities peaked - absolute as well as relative - on the first postoperative day and then gradually levelled off to reach preoperative values after 4-5 days in patients with high CPPI, whereas MCA flow velocities remained increased in the group of patients with low CPPI. At 3 months flow velocities in both groups were normalised. New neurological symptoms occurred in four patients, who all had low CPPI preoperatively (22% (4/18) vs 0%; Fisher's exact test: p=0.006). CONCLUSION: some degree of hyperperfusion was seen in most patients, but the changes were significantly more pronounced in patients with preoperative hypoperfusion, who also suffered significantly more neurological complications.

Real-time spatial compound imaging: application to breast, vascular, and musculoskeletal ultrasound.

Real-time spatial compound imaging (SonoCT) is an ultrasound technique that uses electronic beam steering of a transducer array to rapidly acquire several (three to nine) overlapping scans of an object from different view angles. These single-angle scans are averaged to form a multiangle compound image that is updated in real time with each subsequent scan. Compound imaging shows improved image quality compared with conventional ultrasound, primarily because of reduction of speckle, clutter, and other acoustic artifacts. Early clinical experience suggests that real-time spatial compound imaging can provide improved contrast resolution and tissue differentiation that is beneficial for imaging the breast, peripheral blood vessels, and musculoskeletal injuries. Future development of real-time spatial compound imaging will help address the bulk of general imaging applications by extending this technology to curved array transducers, tissue harmonics, panoramic imaging, and three-dimensional sonography.

[Lipid lowering treatment of patients with atherosclerotic disease of the lower extremities]. / Lipidsaenkende behandling af patienter med aterosklerotisk sygdom i underekstremiteterne.

Patients with critical peripheral ischaemia have a significant mortality rate of up to 50% within 4-5 years of surgical vascular reconstruction. This poor survival rate is due to concomitant coronary and cerebrovascular atherosclerotic disease. Large randomised trials have shown that dyslipidaemia is easily modifiable in patients both with and without established coronary artery disease, with significant reductions in cardiovascular morbidity and mortality. Although none of these trials directly measured peripheral vascular status, there is every indication that conclusions submitted for patients with ischaemic heart disease can be translated to patients with peripheral arterial disease (PAD). The object of this review was therefore to divulge the current evidence available, which supports active treatment of dyslipidaemia in patients with PAD.

Eversion carotid endarterectomy generates fewer microemboli than standard carotid endarterectomy.

OBJECTIVES: to test whether the occurrence of microembolism differed between eversion and standard carotid endarterectomy (CEA). DESIGN: prospective, non-randomised transcranial Doppler (TCD) monitoring study of 61 patients. MATERIALS AND METHODS: eversion CEA was performed in 27 and standard CEA in 34 patients. Surgery was performed under general anaesthesia. Three (5%) patients had a shunt inserted based on continuous EEG monitoring. Continuous middle cerebral artery TCD monitoring (EME, TC-4040) was performed intraoperatively and for 45 min postoperatively on day 1, day 2-3, day 4-5 and after 3 months. Unidirectional signals lasting >25 ms, having intensities of >9 dB were considered to represent embolic events. RESULTS: intraoperative embolic events were detected in 50 (93%) of 54 patients in whom successful intraoperative TCD monitoring was achieved. Events occurred most frequently immediately following clamp release (85%), without difference between the two techniques. Embolic events were encountered postoperatively in four (15%) and 16 (48%) patients having eversion and standard CEA, respectively (p< 0.02). Four patients developed new neurological symptoms equally distributed between eversion and standard CEA. Two (3%) deficits were permanent and two transient. The patency of the carotid bifurcation was confirmed in all instances with duplex scanning. CONCLUSION: we identified a surprisingly high number of postoperative embolic events as detected with transcranial Doppler in patients who had undergone carotid surgery using standard endarterectomy, as compared to patients who underwent eversion endarterectomy. Whether this difference has any clinical implication has yet to be proved.

[Follow-up after infraligamental PTA treatment]. / Followup efter infraligamentaer PTA-behandling.

A total of 48 percutaneous transluminal angioplasties (PTAs) of the superficial femoral and popliteal artery performed between 1993 and 1998 were evaluated with ultrasound duplex scanning and ankle-arm pressure. Twenty-seven (60%) patients presented with claudication and 18 (40%) had limb-threatening ischaemia. Three patients had bilateral PTA. The PTAs were initially successful, corresponding to an early patency rate of 87.5% within the first four weeks. The 12 month patency rate, calculated by life table method, was 68% and 72%, respectively (non-significant). The mortality was 4% and 33% respectively during the first year (p < 0.05). In spite of the size of the material, PTA of the femoropopliteal arterial segment is considered as a valid alternative treatment to vascular surgery in patients presenting with claudication and in patients presenting limb-threatening ischemia.

[Variation of Doppler ultrasonography of carotid arteries]. / Variationen af UL-Doppler undersøgelse af a. carotis.

The variation of ultrasound examination of the carotid arteries performed at two different hospitals was examined by retrospective analysis. Eighty-one patients were primarily examined by ultrasound at their local hospital on the suspicion of carotid stenosis. Following referral, they underwent a further scanning at the Dept. of Vascular Surgery, Rigshospitalet. Results for 143 carotid arteries were available for comparison. The overall agreement between the two examinations was only 59%. In nine of 40 (22%) cases an originally diagnosed minor stenosis was found to be significant and 3/19 (16%) with shown occlusion were found to be patent at the later examination. In order to draw clinical conclusions validation of each individual laboratory performing ultrasound examination of extracranial cervical arteries is necessary.

[Occurrence of carotid stenosis in patients with cerebrovascular symptoms]. / Forekomsten af carotisstenose hos patienter med cerebrovaskulaere symptomer.

Stenosis of the internal carotid artery is a well known risk factor and is estimated to be the cause of 20-30% of all strokes. As ultrasonography easily can demonstrate arterial stenosis and causal surgical treatment is available we found it of interest to investigate the occurrence of stenosis found among consecutive non selected patients with focal neurological symptoms. Results of duplex scanning from consecutive patients with various symptoms were collected. Seventeen percent of the patients who had had transient ischaemic attacks were found to have stenosis of 50% or greater. For the patients with persistent central neurological symptoms (stroke) we found stenosis greater than 50% in 23%. Only a few patients with uncharacteristic, non focal symptoms were found to have stenoses. Carotid stenosis is found in approximately 20% of patients with focal neurological symptoms. Hence ultrasound investigation is indicated for patients suited for surgical treatment.

[Carotid stenosis--is arteriography necessary in investigation and treatment]. / Carotisstenose--Er arteriografi nødvendig ved udredning og behandling?

The present study was undertaken in order to evaluate whether arteriography changed the planned treatment (carotid endarterectomy) of patients with symptomatic carotid artery disease, who had been investigated primarily by ultrasound Duplex scanning. The material was comprised of 50 consecutive patients admitted for arteriography. All patients were symptomatic and were by ultrasound examination found to have lesions of the relevant internal carotid artery (ICA). In three cases arteriography was performed because ultrasound examination was inconclusive. Of the remaining 47 cases, arteriography only changed the planned treatment in three. In one case, arteriography showed a long stenosis continuing into the intracranial part of the ICA, which was not observed by ultrasound. In two cases of minor disease ultrasound overestimated the degree of stenosis. The study concludes that carotid endarterectomy may be performed based on ultrasound duplex scanning, without prior arteriography, if the degree of stenosis is 70% or greater and if the distal end of the stenosis is clearly extracranial.

[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.

[Color Doppler ultrasound examination of carotid arteries]. / Ultralyd farve-Doppler-undersøgelse af arteria carotis. Prospektiv sammenligning med arteriografi.

Eleven hundred and thirty-eight patients suspected of carotid artery disease were examined prospectively by ultrasound-Doppler. In 39 cases, intra-arterial digital subtraction arteriography was performed as well as well and compared to ultrasound Doppler examination. The overall accuracy was 80% (kappa: 0.65). Discrimination between normal and diseased vessels could be made with an accuracy of 93% (kappa: 0.70) and the accuracy when separating vessels into greater or less than 50% stenosis was 88% (kappa: 0.74). Sources of error are discussed and the paper concludes that colour-Doppler examination is an accurate method for assessment of the carotid artery.

[Ultrasound Doppler examination of the carotid artery]. / Ultralyd-Doppler-undersøgelse af arteria carotis.

Ultrasound-Doppler examination of the carotid artery is employed to an increasing extent in investigation of patients with cerebrovascular disease. The diagnostic criteria and results achieved with the various forms: continuous wave Doppler, duplex scanning and colour-Doppler, are described. In the two latter methods, the accuracy is high in the diagnosis of occlusions, quantitating of all degrees of stenosis and also in identification of normal vessels. On comparison with arteriography, the accuracy is stated to be typically 85-95%. The reproducibility of the method is high and equivalent to the results obtained by assessment of the same arteriography by two independent radiologists. The sources of error are discussed and it is concluded that ultrasound-Doppler examination of the carotid artery should replace arteriography in the primary investigation of patients with cerebrovascular disease.