European journal of vascular surgery最新文献

Aims:

To determine whether the new technique of CT-angiography was accurate in displaying the complex anatomy of the aorta and its major branches.

Methods:

Seventeen patients with a variety of aortic pathology were examined. Using a spiral CT-scanner a volumetric scan was made during injection of 150 cc of i.v. contrast. Depending on the chosen CT technique, a body volume with a length ranging between 25–100 cm could be examined in one 50 second spiral scan. On the resulting transverse slices vascular lumina and extent of thrombus were studied. Subsequently, the transverse slices were reconstructed in the coronal or sagittal plane in order to appreciate the craniocaudal relations of the vascular anatomy. Finally, three-dimensional reconstructions were made of vascular lumina and thrombus.

Results:

In aortic aneurysms the extent of the aneurysmal dilatation and of the adherent thrombus could be accurately located relative to the origins of renal and visceral branches proximally, and iliac bifurcation distally. In cases of severe elongation, dissection or complex anatomy, a detailed preoperative insight into the individual anatomy could be obtained. The two-dimensional axial and multiplanar reconstructions offered excellent anatomic detail. The three-dimensional reconstructions, being based on a considerable data reduction, offered an efficient means of providing an overall view of complex anatomic relations.

Conclusion:

The advantage of CT-angiography is that, based on a single spiral scan, the vascular structures in the examined body volume can be displayed in any desired plane using multiplanar reconstructions. Alternatively, three-dimensional renderings can be created. The combination of multiplanar reconstructions and three-dimensional reconstructions makes CT-angiography an accurate technique for displaying even the most complex aortic anatomy.

Near infrared spectroscopy is a non-invasive method for continuous monitoring of tissue oxygenation. In 11 patients undergoing unilateral carotid endarterectomy, changes in cerebral oxygenation following carotid cross-clamping and declamping detected by a near infrared spectrometer were compared with corresponding changes in ipsilateral middle cerebral artery flow velocity measured by transcranial Doppler ultrasonography. Spectroscopic traces were obtained in all patients but adequate Doppler signals in only eight. Changes in cerebral haemoglobin oxygenation correlated closely (r = 0.908, p < 0.001) with changes in middle cerebral artery velocity. The near infrared spectrometer was also sensitive to the changes in cerebral haemodynamics due to intraoperative hypo- and hypertensive episodes. No evidence of cerebral intracellular hypoxia was seen and all patients made an uneventful recovery. Near infrared spectroscopy compares well with transcranial Doppler ultrasound as a monitor of cerebral function during carotid endarterectomy and may have a future role in the elucidation of cerebral perfusion and oxygenation changes following surgery.

Objectives:

Aortic dilatation, dissection and rupture are among the major causes of death in subjects with Marfan's syndrome. The aim of the study was to investigate the mechanical properties or compliance of the aorta in these subjects and compare them with a healthy age- and sex-matched reference population.

Materials and methods:

An ultrasound phase-locked echo-tracking system was used to determine diameter and pulsatile diameter change of the infrarenal aorta in nine subjects with Marfan's syndrome which were then compared with the values for 165 healthy individuals. Compliance, defined as the inverse of Ep (pressure strain elastic modulus) or stiffness (β), was calculated from pulsatile diameter change and blood pressure obtained by the auscultatory method with a sphygmomanometer. For statistical analysis confidence intervals (95%) obtained from the healthy controls were used for comparison. Analysis of covariance (ANCOVA) was performed for the female patients. The sample size for males (n = 2) was too small for the latter analysis.

Results:

Compared with normal subjects and their confidence intervals, subjects with Marfan's syndrome had an increased Ep and stiffness (β) and decreased strain (fractional diameter change) in the infrarenal aorta. Furthermore, ANCOVA in the female patients showed increased β (p < 0.01) and Ep (p < 0.01) and a decreased strain (p < 0.001). Aortic diameters, MAP, as well as the pulse pressure, were similar in the two groups.

Conclusion:

This investigation demonstrates alterations in the mechanical properties of the aorta in Marfan's syndrome in the form of increased stiffness of the aortic wall. This may be of importance in the pathogenesis of aortic dissection and rupture.

The use of human omentum as an alternative to veins as a source of cells for seeding onto small-caliber vascular prostheses has awakened controversy as to the identification of the predominant cell type derived from this source. Mesothelial cells from omentum were extracted by collagenase digestion, and cultured until a monolayer was formed. These cells showed positivity for monoclonal antibodies specific for endothelial cells (anti-CD34 QBEND10), antibodies to intermediate filaments (anti-vimentin and anti-desmin) and anti-smooth muscle cell antibodies (anti-actin and anti-total actin). The mesothelial cells behaved like endothelial cells derived from vein when seeded onto polytetrafluoroethylene prostheses, showing high levels of prostacyclin production. This report provides additional evidence of the non-endothelial origin of the cells derived from human omentum.

Ninety-five infrainguinal polytetrafluoroethylene (PTFE) bypass grafts were performed in 90 patients. Indications for surgery were severe claudication in 23 limbs (24%) and rest pain or tissue necrosis in 72 limbs (76%). Sixty-seven grafts (71%) were to the above knee popliteal artery and 28 (29%) to the infragenicular vessels. The primary, primary assisted and secondary graft patencies at 2 years in limbs with rest pain or tissue necrosis were 37, 42 and 46% respectively with a limb salvage rate of 65%. A univariate analysis was performed to identify preoperative risk factors which affected graft patency. Smoking, an ankle systolic pressure of less than 50 mmHg, presentation with rest pain or tissue necrosis and single vessel run-off all had a significant adverse effect on graft patency. However, multivariate analysis revealed that smoking was the only significant adverse variable. These findings support the view that PTFE grafts for limb salvage are worthwhile even if the distal anastomosis is below the knee and run-off is via a single vessel provided that the patient stops smoking.

Over an 80 month period, 53 transthoracic endoscopic sympathectomies were performed in 34 patients. The indications for surgery were palmar hyperhidrosis in 20 procedures (38%), palmar and axillary hyperhidrosis in eight procedures (15%), Raynaud's phenomenon in 23 procedures (43%), and combined palmar hyperhidrosis and Raynaud's phenomenon in two procedures (4%). Follow-up data, obtained by a self-assessment postal questionnaire, was available for 47 procedures in 30 patients (91%). Fourteen out of 15 procedures (93%) performed for palmar hyperhidrosis, all eight procedures (100%) for palmar and axillary hyperhidrosis and 14 out of 22 procedures (64%) performed for Raynaud's phenomenon produced an immediate improvement in symptoms. These improvements were sustained in 13 procedures (87%) performed for palmar hyperhidrosis, all procedures performed for palmar and axillary hyperhidrosis (100%) but only 10 procedures (45%) performed for Raynaud's phenomenon at a median follow-up of 16, 34 and 44.5 months respectively. There were no deaths nor postoperative Horner's syndrome in these patients. The only minor complications were two small pneumothoraces. Compensatory sweating was observed after 24 procedures (51%). These results confirm that transthoracic endoscopic sympathectomy is a simple, safe and effective procedure. In patients with hyperhidrosis, the results are excellent and prolonged, in patients with Raynaud's phenomenon, immediate improvement can be achieved but the symptoms may return with time.