Complications of cerebral angiography

Characteristics of highly cited articles in cerebral angiography

OBJECTIVE

To present and analyze the characteristics of the 100 most cited articles that used cerebral angiography for clinical evaluation and intervention.

METHOD

Two researchers independently extracted articles from multiple databases and ranked them by citation count to create the "top 100 most-cited" list.

RESULTS

The top 100 articles received a total of 115,243 citations. Twenty-one of the top 100 articles were published between 2006 and 2010. Most studied disorder was ischemic stroke (n = 35), and cerebral angiography was used most frequently for diagnosis (n = 88).The United States was affiliated with the highest number of articles (n = 62), with Stroke publishing most articles (n = 22). Public sources funded 39 articles, private sources funded 35, and 38 articles reported conflicts of interest. Thirty-six studies were randomized controlled trials, and male authors held the majority of both first (n = 90) and senior (n = 88) authorship positions.

CONCLUSION

Within the scope of this study, the following features may define a typical highly cited article-a randomized controlled clinical trial conducted in the United States that studied ischemic stroke, used cerebral angiography for diagnosis, and was published relatively recently in a high-impact journal by male first and senior authors.

Spectrum of Complications and Complication Rates After Diagnostic Catheter Angiography in Neuroradiology

PURPOSE

To retrospectively evaluate the total complication rates and type of complications after diagnostic cerebral and spinal catheter angiography.

METHODS

Data from 2340 patients undergoing diagnostic angiography over a period of 10 years in a neuroradiologic center were retrospectively evaluated. Local, systemic, neurological, and technical complications were analyzed.

RESULTS

A total of 75 clinically noted complications occurred. The risk for clinical complications was increased when the angiography was performed under emergency conditions (p = 0.009). The most common complication was groin hematoma (1.32%). Neurological complications occurred in 0.68% of patients, of which 0.13% were stroke with permanent disability. Technical complications without noticeable clinical symptoms of the patients occurred in 2.35% of the angiographic procedures. Deaths caused by angiography did not occur.

CONCLUSION

There is a definite risk for complications after diagnostic angiography. Although a very broad spectrum of complications was considered, complications in the individual subgroups showed a low incidence.

Incidence, Clinical Significance, and Longitudinal Signal Characteristics of Ischemic Lesions Related to Diagnostic Cerebral Catheter Angiography

PURPOSE

Cerebral DSA is a routine procedure with few complications. However, it is associated with presumably clinically inapparent lesions detectable on diffusion-weighted MRI imaging (DWI lesions). However, there are insufficient data regarding incidence, etiology, clinical relevance, and longitudinal development of these lesions. This study prospectively evaluated subjects undergoing elective diagnostic cerebral DSA for the occurrence of DWI lesions, potentially associated clinical symptoms and risk factors, and longitudinally monitored the lesions using state-of-the-art MRI.

MATERIALS AND METHODS

Eighty-two subjects were examined by high-resolution MRI within 24 h after elective diagnostic DSA and lesion occurrence was qualitatively and quantitatively evaluated. Subjects' neurological status was assessed before and after DSA by clinical neurological examination and a perceived deficit questionnaire. Patient-related risk factors and procedural DSA data were documented. Subjects with lesions received a follow-up MRI and were questioned for neurological deficits after a median of 5.1 months.

RESULTS

After DSA, 23(28%) subjects had a total of 54 DWI lesions. Significantly associated risk factors were number of vessels probed, intervention time, age, arterial hypertension, visible calcified plaques, and less examiner experience. Twenty percent of baseline lesions converted to persistent FLAIR lesions at follow-up. After DSA, none of the subjects had a clinically apparent neurological deficit. Self-perceived deficits were nonsignificantly higher at follow-up.

CONCLUSION

Cerebral DSA is associated with a considerable number of postinterventional lesions, some persisting as scars in brain tissue. Presumably because of the small lesion size and inconsistent location, no clinically apparent neurological deficits have been observed. However, subtle self-perceived changes may occur. Therefore, special attention is needed to minimize avoidable risk factors.

Neurotoxicity Associated with Radiological Contrast Agents Used during Coronary Angiography: A Systematic Review

Contrast media enhances the visualization of the anatomic structures in radiological studies, allowing internal tissues such as blood vessels, kidney, ureters, adrenals and other organs to be identified. The evolution of contrast media highlights the efforts to develop less toxic chemical agents that possess low viscosity and osmolality. However, adverse effects such as idiosyncratic reactions, and organ specific damage are well characterized. Neurotoxicity, an important and dose related effect, appears to be due to disruption of the blood-brain-barrier by the high osmolarity of the contrast agent. From devastating cortical blindness to paralysis and seizures, an array of neurological manifestations has been described. In this systematic review, we describe the contrast-induced neurologic injury following coronary angiography and discuss the proposed mechanisms of injury leading to neurotoxicity.

Cerebral Panangiography in Spontaneous Subarachnoid Hemorrhage from Intracranial Aneurysms

Cerebral panangiography was performed in 594 patients with subarachnoid hemorrhage from intracranial aneurysms. Aneurysm of the middle cerebral arteries was the most frequent location of aneurysms in this material. Multiple aneurysms of the middle cerebral arteries are far more frequent than the combination of other locations. Judged from this material there is a 7 per cent possibility of finding a contralateral aneurysm of the middle cerebral arteries if one is found. Multiple aneurysms were found in 51 (8.6%) of the 594 patients. We conclude that the results of this study are typical for Norwegians, although some selection exists since the patients were first admitted to other hospitals. The frequency of complications with cerebral panangiography in subarachnoid hemorrhage was less than that of cerebral angiography in patients with other diseases.

Angio negative spontaneous subarachnoid hemorrhage: Is repeat angiogram required in all cases?

BACKGROUND

In some cases of spontaneous subarachnoid hemorrhage (SAH), the cause of bleed remains obscure on initial evaluation. These patients may harbor structural lesions. We aim to determine the utility of repeat angiogram in these subsets of patients.

METHODS

In this prospective study, patients with SAH with a negative computed tomographic angiogram (CTA) and digital subtraction angiogram (DSA) were included. A repeat angiogram was done after 6 weeks of initial angiogram. Patients were divided into perimesencephalic SAH (PM-SAH) and diffuse classic SAH (Classic-SAH) groups. Outcome was determined by modified Rankin score (mRS).

RESULTS

A total of 22% (39/178) of all SAH were angio-negative. A total of 90% (n = 35) of these were in Hunt and Hess grade 1-3. A total of 22 patients had PM-SAH and 17 had a Classic-SAH. Repeat angiogram did not reveal any pathology in the PM-SAH group, whereas two patients with Classic-SAH were found to have aneurysms. At 6 months follow-up, 95% patients of PM-SAH and 83.3% of Classic-SAH had mRS of 0.

CONCLUSION

Repeat angiogram is probably not necessary in patients of PM-SAH and they tend to have better outcome. Classic-SAH pattern of bleed is associated with fair chances of an underlying pathology and a repeat angiogram is recommended and these cases and they have poorer outcome.

Advances in functional X-ray imaging techniques and contrast agents

X-rays have been used for non-invasive high-resolution imaging of thick biological specimens since their discovery in 1895. They are widely used for structural imaging of bone, metal implants, and cavities in soft tissue. Recently, a number of new contrast methodologies have emerged which are expanding X-ray's biomedical applications to functional as well as structural imaging. These techniques are promising to dramatically improve our ability to study in situ biochemistry and disease pathology. In this review, we discuss how X-ray absorption, X-ray fluorescence, and X-ray excited optical luminescence can be used for physiological, elemental, and molecular imaging of vasculature, tumors, pharmaceutical distribution, and the surface of implants. Imaging of endogenous elements, exogenous labels, and analytes detected with optical indicators will be discussed.

Complications of cerebral angiography: a prospective analysis of 2,924 consecutive procedures

INTRODUCTION

Cerebral angiography is an invasive procedure associated with a small, but definite risk of neurological morbidity. In this study we sought to establish the nature and rate of complications at our institution among a large prospective cohort of consecutive patients. Also, the data were analysed in an attempt to identify risk factors for complications associated with catheter angiography.

METHODS

Data were prospectively collected for a consecutive cohort of patients undergoing diagnostic cerebral angiography between January 2001 and May 2006. A total of 2,924 diagnostic cerebral angiography procedures were performed during this period. The following data were recorded for each procedure: date of procedure, patient age and sex, clinical indication, referring specialty, referral status (routine/emergency), operator, angiographic findings, and the nature of any clinical complication or asymptomatic adverse event (arterial dissection).

RESULTS

Clinical complications occurred in 23 (0.79%) of the angiographic procedures: 12 (0.41%) significant puncture-site haematomas, 10 (0.34%) transient neurological events, and 1 nonfatal reaction to contrast agent. There were no permanent neurological complications. Asymptomatic technical complications occurred in 13 (0.44%) of the angiographic procedures: 3 groin dissections and 10 dissections of the cervical vessels. No patient with a neck dissection suffered an immediate or delayed stroke. Emergency procedures (P = 0.0004) and angiography procedures performed for intracerebral haemorrhage (P = 0.02) and subarachnoid haemorrhage (P = 0.04) were associated with an increased risk of complications.

CONCLUSION

Neurological complications following cerebral angiography are rare (0.34%), but must be minimized by careful case selection and the prudent use of alternative noninvasive angiographic techniques, particularly in the acute setting. The low complication rate in this series was largely due to the favourable case mix.

Complications associated with selective high-dose intraarterial cisplatin and concomitant radiation therapy for advanced head and neck cancer

PURPOSE

To describe the incidence and severity of complications associated with intraarterial cisplatin and concomitant radiation therapy for advanced head and neck cancer.

MATERIALS AND METHODS

One hundred five patients treated between June 1993 and March 1998 were studied. Forty-seven (44%) had T4 lesions and 40 (37%) had bulky (N2/3) nodal disease. Three hundred eighty-five procedures were performed. All patients were treated with selective intraarterial tumor-directed cisplatin (150 mg/m(2) weekly x 4), simultaneous intravenous thiosulfate (9 g/m(2)) for systemic neutralization of cisplatin, and conventional external-beam radiation to the primary tumor and nodal disease (total dose of 66-74 Gy).

RESULTS

One hundred five patients were evaluated for complications. Twenty-two (5.7%) groin hematomas occurred, none of which needed therapy. Two asymptomatic common carotid artery dissections were reported. Two patients experienced acute occlusion of the external iliac artery requiring a femorofemoral bypass. Overall, there were 41 grade III/IV chemotoxic events related to treatment. Chemotoxic events included 29 mucosal events, nine hematologic events, two otologic events, and one gastrointestinal event. No renal events occurred. There were three permanent and three transient neurologic events.

CONCLUSION

Selective high-dose intraarterial cisplatin and concomitant radiation therapy for advanced head and neck cancer can be performed safely with a relatively low complication rate compared to standard intravenous chemotherapy treatment protocols.

Neurologic complications of cerebral angiography: prospective analysis of 2,899 procedures and review of the literature

PURPOSE

To prospectively identify risk factors for neurologic complications related to cerebral angiography.

MATERIALS AND METHODS

A total of 2,899 consecutive cerebral digital subtraction angiograms obtained with nonionic contrast material were prospectively evaluated. Neurologic complications were categorized as transient (<24 hours), reversible (24 hours to 7 days), and permanent (>7 days). The neurologic complication rate was correlated with patient age, type of indication for catheter angiography, medical history, fluoroscopic time, number and size of catheters, type and number of vessels injected, operator experience, and the quartile in which the study was performed. The correlations were statistically analyzed with Fisher exact tests and a multiple logistic regression model.

RESULTS

There were 39 (1.3%) neurologic complications in 2,899 procedures; 20 were transient (0.7%), five (0.2%) were reversible, and 14 (0.5%) were permanent. Neurologic complications were significantly more common in patients 55 years of age or older (25 of 1,361; 1.8%) (P =.035), in patients with cardiovascular disease (CVD) (20 of 862; 2.3%) (P =.004), and when fluoroscopic times were 10 minutes or longer (24 of 1,238; 1.9%) (P =.022). The neurologic complication rate was higher in procedures performed by fellows alone (24 of 1,878; 1.3%) compared with that when staff alone performed the procedures (three of 598; 0.5%), but the difference was not significant (P =.172). Neurologic complications were lower in the fourth quartile of the study (six of 171; 0.9%) compared with the first quartile (16 of 776; 2.1%), which was likely due to fewer patients being examined for carotid stenosis or ischemic stroke and fewer patients with CVD (P =.085).

CONCLUSION

Age-related vascular disease accounted for the failure to lower the neurologic complication rate of cerebral angiography despite technical advances.

Carotid angiography in conjunction with amytal testing of epilepsy patients

Angiography is carried out as a basic part of the sodium amobarbital procedure in most institutions in order to predict the distribution of the amobarbital before the procedure itself is performed. This paper presents details of cerebral circulation to provide a framework that will help investigators who are not radiologists to interpret angiography results. The application of angiography specifically to the amobarbital procedure and the implications of different patterns of arterial filling for interpretation of speech and memory test results are discussed.

Does a safe size-limit exist for unruptured intracranial aneurysms?

Of 1076 patients with intracranial ruptured aneurysms (RA) included in the Danish Aneurysm Study, 948 had the RA verified by angiography. Of these cases 908 RA had a maximum diameter less than 25 mm. 162 RA were < 5 mm, 474 and 272 were between 5-10 mm and 11-24 mm, respectively. The average diameter of the RA according to the day of angiography after the aneurysm rupture did not differ significantly within the first 10 days. In these circumstances, using this indirect method for estimation of aneurysm rupture according to the size, we also recommend that unruptured aneurysms with a size 10 mm or less should be seriously considered for operation.

Magnetic resonance angiography in the preoperative evaluation of abdominal aortic aneurysms

Magnetic resonance angiography (MRA) and magnetic resonance imaging (MRI) are noninvasive techniques of visualizing blood vessels without the use of intravenous contrast or ionizing radiation. This prospective study assessed preoperative MRA and MRI in the evaluation of 28 patients with abdominal aortic aneurysm (AAA). MRI and MRA accurately predicted the extent of cephalad AAA, the patency of the superior mesenteric artery, and the course of the left renal vein, but were less accurate in defining the extent of caudal AAA, flow of the inferior mesenteric artery, and multiple renal arteries. This study suggests that MRI and MRA are alternatives to the combination of angiography and computed tomographic scan in the preoperative evaluation of patients with suspected AAA and no evidence of mesenteric or renal ischemia. When combined with preoperative segmental Doppler arterial studies, an accurate surgical plan may be formulated. Further refinements in image acquisition and postprocessing software analysis will advance the use of MRI and MRA for complete evaluation prior to elective AAA repair.

Persistent hypoglossal artery: An anomaly leading to false-positive carotid duplex sonography

Duplex ultrasonography is becoming increasingly popular as the sole diagnostic test in the evaluation of carotid artery bifurcation disease. We present a patient with a persistent hypoglossal artery, a rare primitive internal carotid-basilar anastomosis, masquerading as an internal carotid artery stenosis on ultrasound. The operative management of this anomaly is reviewed.

A case of intracerebral air embolism secondary to the insertion of a Hickman line

Complications following the insertion of intravenous catheters are relatively uncommon. We report a potentially serious, hitherto unrecognized complication of Hickman line insertion, and discuss the condition.

Neurologic complications of axillary and brachial catheter arteriography in atherosclerotic patients: predictive factors

Catheter arteriography by the axillary or brachial route can be responsible for central neurologic complications. The objectives of this prospective study were to define the predictive factors of these complications and determine their incidence. This report is based on 288 consecutive arteriography sessions performed between January 1985 and June 1987. All patients had arterial atheromatous pathology. Ten central neurologic complications (3.5%) occurred, two of which (0.7%) were permanent. Four factors were significantly associated with increased incidence of central neurologic complications: antecedent transient ischemic attack (p less than 0.001); tight (greater than 80%) stenosis of at least one internal carotid artery (p less than 0.02); angina pectoris (p less than 0.05); age over 80 years old (p less than 0.001). Seldinger's or Dos Santos' techniques are preferable to axillary or brachial catheter techniques for investigation of the lower limbs and the abdominal aorta. The former obviates the need to catheterize the aortic arch and reduces the risk of embolism to the supraaortic arteries. Digital venous arteriography is an alternative to aortic arch catheterization when investigating the supraaortic arteries in the presence of risk factors.

Clinical features, pathogenesis and management of drug-induced seizures

Many classes of pharmacological agents have been implicated in cases of drug-induced seizures. The list includes antidepressant drugs, lithium salts, neuroleptics, antihistamines (H1-receptor antagonists), anticonvulsants, central nervous system stimulants, general and local anaesthetics, antiarrhythmic drugs, narcotic and non-narcotic analgesics, non-steroidal anti-inflammatory drugs, antimicrobial agents, antifungal agents, antimalarial drugs, antineoplastic drugs, immunosuppressive drugs, radiological contrast agents and vaccines. For each of these classes of drugs, this article offers a revision of the literature and emphasises in particular the frequency of the adverse reaction, its clinical presentation, its presumed epileptogenic mechanism and the therapeutic strategy for the management of drug-induced seizures. An attempt is also made to distinguish seizures induced by standard dosages from those provoked by accidental or self-induced intoxication. For some classes of drugs such as antidepressants, neuroleptics, central nervous system stimulants (e.g. theophylline, cocaine, amphetamines) and beta-lactam antibiotics, seizures are a well recognised adverse reaction, and a large body of literature has been published discussing exhaustively the major aspects of the issue; sufficient data are available also for the other classes of pharmacological agents mentioned above. In contrast, several other drugs [e.g. allopurinol, digoxin, cimetidine, protirelin (thyrotrophin releasing hormone), bromocriptine, domperidone, insulin, fenformin, penicillamine, probenecid, verapamil, methyldopa] have not been studied thoroughly under this aspect, and the only source of information is the occasional case report. This review does not address the issue of seizures induced by drug withdrawal.

Cerebral angiographic risk in mild cerebrovascular disease

We review the eight prospective and seven retrospective studies from which it is possible to derive the complication rate of conventional cerebral angiography for patients with mild ischemic cerebrovascular disease who are potential candidates for carotid endarterectomy. Three studies of intravenous and one of intra-arterial digital subtraction angiography are also examined. An overview of the results suggests that the risk of a neurological complication (TIA or stroke) is about 4% and that a permanent neurological deficit (disabling stroke) occurs in about 1%. The mortality rate is very low (less than 0.1%). Systemic complications are not infrequent, particularly with intravenous digital subtraction angiography. The complication rate of cerebral angiography must be considered when evaluating the risks of carotid endarterectomy in patients with ischemic cerebrovascular disease.

Safe extracranial vascular evaluation and surgery without preoperative arteriography

Carotid surgery without preoperative arteriography was performed in 101 consecutive patients with an average age of 68.5 years and almost equal sex distribution. This prospective study analyzed risk factors, operative approach, bruits, indications for surgery, and outcome. All patients were studied by real-time B-mode ultrasound and spectral analysis and none were referred for arteriogram. The majority of patients had a standard carotid endarterectomy, and the findings at surgery correlated with noninvasive imaging. No mortality was recorded in this series of patients; a 1% rate of neurologic morbidity was noted. These results suggest that one can safely operate on the basis of a duplex scan. A preoperative arteriogram is not always necessary for carotid evaluation.

Relative safety of intravenous digital subtraction angiography over other methods of carotid angiography and impact on clinical management of cerebrovascular disease

Data from a multicentre survey based on three London teaching hospitals on the relative safety and clinical utility of intravenous carotid digital subtraction angiography (DSA) over intra-arterial DSA and conventional carotid angiography are presented. The incidence of stroke during intra-arterial DSA was 0.7% (n = 538) and during conventional angiography was 0.8% (n = 780). The incidence of stroke during intravenous DSA was zero (n = 3710). When it constituted the initial investigation, intravenous DSA achieved a 93.8% replacement value over intra-arterial studies as a whole (n = 474) and 89% replacement value for patients having carotid endarterectomy (n = 99). It was also noted that the installation of DSA equipment at one unit coincided with a sixfold increase in the number of carotid angiographic examinations and an almost threefold increase in carotid endarterectomies.

Vertebrobasilar insufficiency revealed by xenon-133 inhalation SPECT

A study of cerebral and cerebellar blood flow reactivity to acetazolamide by xenon-133-inhalation single photon emission computed tomography (133Xe SPECT) was carried out in a patient with bouts of transient basilar ischemia, whose neurological examination, computed tomographic scan, and auditory evoked potentials were normal. Though the patient was symptom-free at the time of the study, 133Xe SPECT demonstrated vertebrobasilar insufficiency by showing an impaired vasodilatory response in both the occipital lobes and the right cerebellar hemisphere. Three weeks later, the patient suffered an extensive stroke in these same areas. We therefore suggest that this method could be of great value in the assessment of vertebrobasilar insufficiency.

Nonconvulsive status epilepticus following cerebral angiography

A 64-year-old man developed lethargy and aphasia immediately following cerebral arteriography with iothalamate meglumine. An electroencephalogram showed continuous epileptiform activity. The patient was treated with intravenous phenytoin with complete resolution of clinical symptoms and electroencephalographic epileptiform abnormalities. The diagnosis of nonconvulsive status epilepticus should be considered in cases of altered consciousness following cerebral arteriography.

Cerebral angiography for cerebrovascular disease: the risks

Cerebral angiography is still suggested as a first line investigation for patients with putative transient ischaemic attacks (TIA) and it is considered by most surgeons as a necessary prelude to carotid endarterectomy. That conventional cerebral angiography involves risk is well known, although the magnitude of this risk is not. Prospective studies of cerebral complications from this technique, published over the last decade, have been analysed to show that the major stroke rate after conventional cerebral angiography for patients with TIAs is likely to be about 2.4 per cent. This must be taken into account if the true morbidity of carotid endarterectomy is to be appreciated (assuming conventional angiograms have been used). Furthermore, since many sufferers are assessed by angiography but not submitted to surgery, a policy of conventional angiography for patients with TIAs puts a far greater number at risk than that actually having carotid endarterectomy.

The limitations of diagnosis of carotid occlusion by Doppler ultrasound

Duplex scanning has been advocated as an acceptable alternative to angiography in the preoperative evaluation of carotid artery stenosis. To evaluate the accuracy of carotid Doppler in differentiating severe carotid stenosis from occlusion, we compared the results of angiography with duplex scanning in 124 carotid arteries (62 patients) and with continuous-wave Doppler in 662 carotid arteries (331 patients). The specificity was 95-99%, sensitivity was 86-96%, and accuracy was 95-98%. Duplex scanning wrongly identified occlusion in four arteries and failed to detect occlusion in one artery. In making decisions prior to carotid endarterectomy, even infrequent errors are unacceptable. We recommend angiography of all surgical candidates with apparent severe stenosis when the internal carotid artery cannot be clearly identified on duplex, or to distinguish apparent occlusion from undetectably low blood flow.

Complications in cerebral angiography with iohexol (Omnipaque) and meglumine metrizoate (Isopaque cerebral)

The complications of cerebral angiography have been recorded in 1509 examinations with metrizoate (Isopaque Cerebral) and in 1000 examinations with iohexol (Omnipaque). The frequency of complications was 2.0 percent for metrizoate and 1.3 percent for iohexol. Permanent sequelae were seen in 4 patients, 3 in the metrizoate and one in the iohexol group. One of these patients died, probably from thromboembolism. Blood coagulation parameters were studied during the angiography in 22 patients and only minor, probably clinically insignificant changes were found, with no difference between the two contrast media.

Clinical events following neuroangiography: a prospective study

Clinical events following cerebral angiography were prospectively evaluated in 1,002 procedures. The ischemic event rate between 0 and 24 hours was 1.3% (0.1% permanent). This incidence was higher (2.5%) in patients investigated for cerebrovascular disease, but the difference was not significant. In addition, 1.8% of the patients suffered ischemia (0.3% permanent) between 24 and 72 hours after angiography. Cerebral ischemic events occurred as a recurrence or worsening of a preexisting phenomenon. twice as often as de novo. All permanent ischemia was a worsening of a preexisting phenomenon. There was a significant increase in the incidence of neurologic events between 0 and 24 hours when the procedure lasted longer than 60 minutes and when there was systolic hypertension. Trends toward higher incidence were noted with the use of increased volume of contrast, with increased serum creatinine, when transient ischemic attacks or stroke were the indications, and when 3 or more catheters were used. The incidence of neurologic events between 24 and 72 hours increased significantly with the increase in the amount of contrast used, with age, and with diabetes. The occurrence of nonneurologic events (mostly hematomas) was significantly increased by multiple factors. This study shows that events can and do occur beyond the usual observation period of 24 hours but confirms the low risk of cerebral angiography when performed judiciously.

Neurological complications of cerebral angiography

We report a prospective study of 218 consecutive patients undergoing cerebral diagnostical angiography, before during and 24 hours after the procedure, to identify the neurological complication rate and the risk factors related to the patients and to the procedure. We observed 15 neurologic accidents (6.9%) with permanent sequelae in one case (0.4%). Two risk factors proved to correlate significantly with accidents, i.e. the time that the catheter remained within a vessel and difficulty in performing the procedure.

Particulate contamination in eye surgery

Flushing fluid from microsponges (surgical spears) and solutions for irrigation (balanced salt solution and Ringer solution) as well as other medicaments for intraocular use during surgery (solutions of Zolyse, solutions of Miochol and Healon) have been examined for particulate contamination. The method used to collect and analyse the particles involved scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDAX) in order to determine elements within the range of atomic number 9-93 in the periodic system. The investigation disclosed particulate contamination of all solutions examined. Particle number (greater than 5 microns) per ml varied from 15 to 400 and the size from 5 microns-800 microns. Microsponges released particles in numbers from 25-90 in a size range of 5-3000 microns per ml flushing fluid (Total flushing volume 20 ml). More than half of the particles were below 10 microns in all specimens examined. The irrigation solutions and solutions of medicaments contained only few particles above 40 microns. Most of the particles were of organic material which is not detectable with EDAX. This analytical system disclosed a wide range of inorganic elements, being present in the examined solution in the form of particles or as solutes.

The influence of noninvasive tests on the selection of patients for carotid angiography

To assess the impact of noninvasive testing of the carotid vessels upon patient management, we analyzed the angiographic findings in 494 patients studied between 1978 and 1983 for suspected extracranial cerebrovascular disease. This longitudinal study revealed two changes in the pattern of angiographic results after introduction of noninvasive testing in the final months of 1979. The proportion of examinations that revealed less than 49% stenosis decreased significantly from 49% in 1978 to 19% in 1983 (p less than 0.001). During the same time, the proportion of examinations identifying 75-99% stenosis increased from 20% to 62% (p less than 0.001). The referring physicians and their patient population appeared to remain unchanged over these years. We believe the decline in patients with little or no disease is a consequence of better patient selection due to screening with noninvasive tests. We credit the increase in patients with 75-99% disease to additional patients identified by noninvasive tests. This study also points out that the role of noninvasive studies will necessarily be restricted because of inherent limitations in the techniques and that clinical judgment will remain the final arbiter with regard to the management of patients at risk for stroke.

[Cerebral angiography in complicated migraine--reactions, incidents]

Seventy-one patients (ages: 15-58 years) suffering from complicated migraine were investigated by means of cerebral angiography which was not performed during an attack. Angiography was carried out to exclude stenoses or occlusions of the cranio-cervical vessels and above all vascular malformations (arterial aneurysms, arteriovenous angiomas). In 18 cases (25.4%) organic lesions were found, including three vessel malformations (4.2%). Thirty-one patients (43.7%) suffered from headache reactions or other complications during or within 24 h following angiography. In 15 cases (21.1%) attacks of complicated migraine were observed, three patients (4.2%) suffered from headache and bilateral flickering visual disturbances, another 11 patients (15.5%) developed headache and vegetative symptoms requiring therapeutic management. One patient (1.4%) got an epileptic seizure, another patient (1.4%) developed a generalized urticaria exanthema. There were more headache reactions in women than in men. However, the highest percentage of reactions was observed in patients in whom migraine headache had occurred clearly set off from the transient cerebral functional disturbances. Neurological complications (transient functional disturbances) occurred in 16 of 71 patients (22.5%). The neurological complication rate was significantly (P less than 0.001) higher than that in an unselected group of patients (3.0%).(ABSTRACT TRUNCATED AT 250 WORDS)

Digital subtraction angiography in patients with cerebral ischaemic attacks and normal continuous wave Doppler studies

The cervico-cranial arteries were studied using digital subtraction angiography in 50 patients with reversible cerebral ischaemic attacks and normal continuous wave Doppler examination. Digital subtraction angiography was able to visualise the arteries satisfactorily in 45 patients (90%), and revealed minor arterial abnormalities in 12 patients (24%). However, neither occlusions nor stenoses greater than 50% of the diameter of the vessel lumen were found. Although digital subtraction angiography is more accurate than continuous wave Doppler examination in detecting arterial lesions, it did not provide alternative therapeutic choices in any of these patients.

Cerebral air embolism occurring at angiography and diagnosed by computerized tomography. Case report

A case of air embolism complicating cerebral angiography is presented. The presence of the embolism was confirmed with high-resolution computerized tomography scans using appropriate window settings.

Encephalopathy following arteriography: a possible toxic effect of contrast agents

Three elderly men being evaluated for cerebrovascular disease developed acute confusional states following arteriography with approximately 50 ml of meglumine iothalamate. Two patients became stuporous. All recovered in several days, and no specific cause was found for the disorder. In the absence of other demonstrated abnormalities, we suggest that in each patient the encephalopathy may have been a toxic reaction to the contrast agent.

Neurotoxicity of radiological contrast agents

The most important complications of intravascular administration of contrast agents include idiosyncratic (anaphylactoid) reactions, shock, congestive heart failure, cardiac arrhythmias, acute renal failure, and neurotoxic effects. The incidence of serious neurotoxic effects is low. Entry of contrast agents into the central nervous system normally is limited but may be increased by osmotic opening of the blood-brain barrier with cerebral arteriography or arch aortography. Most neurotoxic effects are thought to represent direct effects of the contrast agent on brain or spinal cord. Adverse effects with arteriography include seizures, transient cortical blindness, brain edema, and spinal cord injury. Most cases of focal brain deficit (other than cortical blindness) are attributed to embolism secondary to the catheter. Seizures may occur with intravenous administration, especially in patients with brain tumors or other processes disrupting the blood-brain barrier. The most important adverse effects observed with myelographic agents include acute and chronic meningeal reactions with iophendylate, and seizures and transient encephalopathy with metrizamide.

Right brachial angiography with compression. Review of the literature

A technique for performing right brachial angiography by compressing the right anterior-inferior part of the neck is proposed, as a result of studying the left carotid circulation without puncturing the left carotid artery. A success was obtained in about 75% of cases. The success of the technique depends mainly on the anatomical nature of the innominate artery. When the technique is successful both left carotid arteries in the neck and their intracranial branches can be satisfactorily visualized. In some cases visualization of the left vertebral artery was also obtained. Attention is drawn also on the increased diagnostic possibilities of studying the vessels in the neck with a greater dilution of the contrast medium.

The role of vertebral angiography in the investigation of third nerve palsy

The association between intracranial aneurysm and third nerve palsy in a series of fifty patients presenting to this unit over a six year period has been studied. All aneurysms causing a third nerve palsy were found to be in the anterior circulation and all were adequately demonstrated by carotid angiography alone. None of the thirty cases of posterior circulation aneurysm was associated with a third nerve palsy. Vertebral angiography carries a higher risk of serious complications than carotid angiography. We feel that the added risk of vertebral angiography is not justified for the investigation of an isolated third nerve palsy.

The role of computed tomography in the diagnosis and management of brain tumors

This review article emphasizes the role of computed tomography in the diagnosis and management of brain tumors. The head CT scan has become one of the most precise noninvasive tests in the neurosciences. It has given clinicians more information than they were able to obtain in the past. The subject is covered by subdividing it into several categories: detection of true tumor extent, radiation treatment planning, the immediate postoperative period, treatment responses, failure patterns, detection of radiation-induced damage, and the potential to predict histopathology. The paper is illustrated with examples that emphasize the advantages and some of the limitations of computed tomography as it exists today.

Right retrograde brachial cerebral angiography with simultaneous compression of the left carotid artery

Right retrograde brachial angiography with simultaneous compression of the left common carotid artery was performed in 12 patients, invariably resulting in filling of the right vertebral and the basilar artery. In all but one patient, the right carotid artery and its branches were also filled. Retrograde filling of the left internal carotid artery occurred in 8 patients. Furthermore, retrograde filling of the intracranial part of the left vertebral artery was obtained in 5 of 12 patients. A complete four-vessel cranial angiography was thus obtained in one third of the patients. The method may be considered as a safe and valuable adjunct to other angiographic techniques.