Thrombolysis for acute lower limb ischaemia--a prospective, randomised, multicentre study comparing two strategies.

OBJECTIVES: To test if initial high-dose, pulse-spray thrombolysis improves the early and late outcome of lower limb ischaemia as compared with low-dose infusion alone. DESIGN: Prospective randomised multicentre study. MATERIAL AND METHODS: Patients with acute and sub-acute (<30 days) lower limb ischaemia were randomised following angiography. Group 1 (n=58) received pulse-spray infusion of recombinant plasminogen activator (rt-PA, 15 mg/h) for 2h followed by low-dose infusion if needed. Group 2 (n=63) were only treated with low-dose infusion (0.5mg/h) of rt-PA for 48 h. Underlying lesions were corrected if required. RESULTS: The study was stopped prematurely. Complications were equally frequent in both groups. More than 75% lysis was accomplished in 78 versus 67% of the patients (p=0.21). Primary endpoints (re-occlusion, incomplete lysis, life-threatening complication, amputation, or death) were reached in 24 versus 32% of the patients (p=0.35). Neither vascular patency nor clinical parameters differed during the first year, but re-interventions tended to be more frequent (p=0.040 at 1 month; p=0.090 at 1 year) and of a greater magnitude (p=0.028) in group 2. CONCLUSIONS: There was no obvious advantage with initial high-dose thrombolysis, which may be a type-2 error. A reduction of major re-interventions was recorded.

Does an adjuvant AV-fistula improve the patency of a femorocrural PTFE bypass with distal vein cuff in critical leg ischaemia?--a prospective randomised multicentre trial.

INTRODUCTION: A lack of suitable veins can cause serious problems when attempting to revascularise critically ischaemic legs. Prosthetic grafts have much worse patency in the femocrural position, despite the use of distal anastomotic cuffs. The use of adjuvant AV-fistula at the distal anastomosis should increase the graft flow above the thrombotic threshold velocity and thus increase prosthetic graft patency. AIM: The aim of the study was to evaluate the benefit of an adjuvant AV-fistula on the patency of a femorocrural PTFE bypass with a distal vein cuff. MATERIALS AND METHODS: This prospective randomised multicentre trial was conducted in four centres. A total of 59 patients with critical leg ischaemia and no suitable veins for grafting were randomised to receive a femocrural PTFE bypass and distal vein cuff, with or without an adjuvant AV-fistula. Thirty-one patients were randomised to the AV-fistula group (AVFG) and 28 to the control group (CG). Six patients were lost to follow-up during the 2-year study time. RESULTS: There were six immediate occlusions in each treatment group, but half of these were saved by re-operation. The mean postoperative ankle-brachial index (ABI) was 0.85 in the AVFG and 0.94 in the CG. The primary and secondary patency rate at 2 years was 29 and 40% for the AVFG and 36 and 40% for the CG (NS). Leg salvage at 2 years was 65 and 68%, respectively (NS). CONCLUSION: Adjuvant AV-fistula does not improve the patency of a femorocrural PTFE bypass with a distal vein cuff.

Imaging of aortoiliac arterial disease. Duplex ultrasound and MR angiography versus digital subtraction angiography.

PURPOSE: To evaluate and compare the diagnostic accuracy of duplex ultrasound (US) and MR angiography (MRA) at 1.0 T in aortoiliac arterial disease using digital subtraction angiography (DSA) as the reference standard. In addition, a comparison of the 2D time-of-flight (TOF) and 3D contrast-enhanced MRA (CE MRA) techniques was performed. MATERIAL AND METHODS: Prospectively, 39 patients with symptoms of lower-extremity arterial occlusive disease were examined using US, TOF MRA, CE MRA and DSA. Significant lesions (stenosis > or =50%) and occlusions were evaluated blindly for each method. RESULTS: For all segments, the sensitivity for US, TOF MRA and CE MRA with regard to significant lesions was 0.72, 0.81 and 0.81, respectively, and the specificity for each was 0.97, 0.91 and 0.92, respectively. For significant lesions above the inguinal ligament the corresponding sensitivity was 0.84, 0.89 and 0.94 and the specificity 0.93, 0.82 and 0.73, respectively. The specificity was higher when the two MRA methods were combined. TOF MRA overgraded 7 segments as occluded. In most cases, the length of the occlusions was correctly determined on CE MRA, overestimated on TOF MRA and uncertain on US. CONCLUSION: Neither US nor MRA were sufficiently accurate to fully replace angiography. MRA was preferable to US as a non-invasive test when vascular intervention was contemplated. Although CE MRA was superior to TOF MRA, the most accurate results were achieved when the two methods were combined.

Percutaneous placement of stents in chronic iliac and aortic occlusive disease.

OBJECTIVES: to evaluate the long-term results of stenting in iliac and aortic occlusive disease and identify factors predicting clinical outcome. DESIGN: retrospective study. MATERIALS AND METHODS: 82 patients (87 limbs) with stenoses (n =63) and occlusions (n =24) in the aortoiliac segment were treated with stents. 81 lesions involved the iliac arteries, 3 the infrarenal aorta and 3 the aortic bifurcation. Primary stenting was performed in 57 limbs (complex stenotic lesions and occlusions). Stents were placed following failed PTA in 30 limbs. Median follow-up was 13.2 months (1-66 months). RESULTS: technical success was 99% and clinical success 89%. Cumulative primary and secondary patency of stented iliac atherosclerotic lesions at 1 and 3 years was 75 and 61%, and 83 and 75% respectively. The factors predicting outcome of primary patency identified in Cox multivariate analysis were ankle-brachial index (ABI) prior stenting (p =0.03) and length of the lesion (p =0. 007). Major non-fatal complications occurred in 7.4% of the patients and there were no deaths attributed to the treatment. The 30-day mortality was 3.7%. CONCLUSION: stenting of complex aortoiliac stenoses and chronic occlusions is a safe and effective treatment modality. Long lesions and lower pre-procedure ABIs were found to negatively influence outcome.

Cranial nerve injuries after carotid artery surgery. A prospective study of 663 operations.

OBJECTIVE: To establish the incidence of cranial nerve injuries caused by carotid artery surgery. METHODS: During the years 1982 to 1992, 689 carotid artery operations were performed at Malmö General Hospital. Of these 656 were pre- and postoperatively examined at the Department of Phoniatrics concerning the function of the cranial nerves IX, X, and XII. RESULTS: There was injury to one or more of the examined nerves after 75 operations (11.4%). In 70 (10.7%) operations the hypoglossal nerve was injured, in eight (1.2%) the recurrent laryngeal nerve, in two (0.3%) the glossopharyngeal nerve and in two (0.3%) the superior laryngeal nerve. Seven patients complained of postoperative hoarseness, but had no injuries. One hypoglossal and one recurrent nerve injury was permanent. Nerve injury was more frequent in operations performed with a shunt (p = 0.05), with patch closure (p = 0.01) and by a junior surgeon (p = 0.05). CONCLUSION: In a prospective series, the incidence of cranial nerve injuries after carotid surgery was significant but the vast majority were reversible.

CT assessment of subarachnoid haemorrhage. A comparison between different CT methods of grading subarachnoid haemorrhage.

A number of different CT classifications of subarachnoid haemorrhage (SAH) were applied to a consecutive series of 50 patients with aneurysmal SAH. The best correlation with delayed ischaemic deficits (DID) was obtained with a score formed by the sum of the individual cisternal grades except that of the cortical subarachnoid space. The findings emphasize the significance of the extent of the SAH, rather than the presence of a localized cisternal clot with regard to the development of DID.

Pressure measurements as predictors for peroperative neurologic deficits in carotid surgery.

Forty-eight carotid endarterectomies were performed using local anaesthesia. The need for an intra-operative shunt was estimated from the development of neurological symptoms during a test clamping period of 1 min. Two patients developed symptoms during test clamping but four others developed symptoms after 11 to 20 min of clamping. The internal carotid back pressure was 30 to 40 mmHg in all these cases and significantly lower than among patients not developing symptoms. A better prediction of the need for a shunt was developed from a combination of the stump index (SI = internal carotid artery stump pressure/systemic pressure x 100) and the carotid index (CI = carotid pressure before clamping/systemic pressure x 100). The combination of SI less than 30 and CI greater than 85 predicted in a highly significant way the need for a shunt during operation. With this method a group of patients with a higher risk of postoperative stroke may also be detected.

Local versus general anaesthesia in carotid surgery. A prospective, randomised study.

A randomised, prospective study was performed to compare local (LA) and general anaesthesia (GA) in carotid surgery with special emphasis on complications and the need for intra-operative shunting. Fifty-six patients were randomised to LA and 55 to GA. Eight patients in the LA group required a GA for various reasons. During the same period 14 patients were not randomised. Seven perioperative neurological deficits occurred (5.6%), four in the LA group, two in the GA group, and one in the non-randomised group (NS). Selective shunting was used, in the Ga group according to stump pressure or in cases with a previous stroke and in the LA group according to the appearance of neurological symptoms. In the GA group 25 patients were shunted and in the LA group five patients (P less than 0.001) needed a shunt. If strict pressure criteria for shunting had been used in the LA patients, ten would have been shunted and three of the patients who developed symptoms during clamping would not have been shunted. During surgery the highest recorded systolic pressure was significantly higher in the LA group (210 mmHg versus 173 mmHg, P less than 0.001). LA for carotid endarterectomy is comparable with general anaesthesia regarding peroperative complications but produces significantly higher blood pressures than general anaesthesia. On the other hand it allows the possibility of neurologic monitoring of the patient and leads to significantly less use of an intra-operative shunt.

Long-term results after carotid artery surgery.

This study presents the results from a follow-up after 414 carotid reconstructions performed on 352 patients during the years 1971-82. At the end of the follow-up period 267 patients were alive (75.8%) and 253 patients remained asymptomatic. The median follow-up time was 35 months (6 months-12 years). Patients with coronary artery disease (CAD) had a significantly lower survival than patients without signs of CAD. Coronary artery disease was significantly more frequent among patients with bilateral carotid lesions compared to patients with unilateral lesions. The actuarial stroke frequency, operative morbidity included, on the operated side was 2.5%/year. However, from 6 months postoperatively up to 8 years the stroke frequency was 1%/year. In the stroke frequencies all neurological deficits of more than 24 h duration are accounted for. Although there was a trend toward higher stroke rates among older patients there were no significant differences between age groups. Assuming a 10% stroke frequency during the first year after a TIA and a 6% annual stroke rate thereafter our results would cross even such a natural course curve at 18 months.

Risk factors in carotid artery surgery: an evaluation of 414 operations.

Four hundred and fourteen carotid reconstructions performed on 352 patients during the years 1971-82 were analysed retrospectively. Fifty-eight percent of the patients were operated on because of hemispheric transient ischaemic attacks (TIA). Twenty-eight percent had suffered a stroke before surgery. The overall combined mortality and morbidity was 7.7%. The procedure mortality was 2.9% with a slightly higher mortality i.e. 5.9% in the stroke group although not significantly higher than among non-stroke patients with a mortality of 1.4%. Patients of more than 70-years had a significantly higher operative mortality (11.1%) than the rest of the patients (1.7%). Non-fatal strokes occurred in 20 patients (4.8%). No correlation was found with the degree of stenosis of the contralateral artery.

Cranial nerve injuries associated with carotid endarterectomy. A prospective study.

To determine the incidence and nature of cranial nerve damage in connection with carotid artery surgery, 139 patients were studied before and after 162 operations. Nerve damage was detected in association with 19.8% of the operations. The hypoglossal nerve was most commonly affected. The injuries were of benign character and usually resolved within 4 to 6 weeks. Apart from damage to the great auricular nerve, all lesions resolved within 5 months. The incidence of nerve disturbance was greater than that found in a retrospective study from the same hospital. Gentleness of technique is important in carotid artery surgery, in order to avoid nerve damage.