Spontaneous dissection of the internal carotid artery

The arteriographic diagnosis of spontaneous, nontraumatic dissection of the internal carotid artery was made in 19 patients and confirmed at operation in ten. The tapered narrowing beginning in or about the carotid bulb and ending at the bony canal was a consistent finding. Four patients had associated aneurysm formation. All but one patient developed an acute hemispheric neurologic deficit as the initial symptom. The deficit was transient in ten and prolonged in eight. The dissection occurred in the outer layers of the media. None of the surgical specimens showed atherosclerosis. Surgical methods of management included segmental resection and grafting, thrombectomy and intimectomy, dilation, and simple ligation. Considerable improvement of luminal diameter occurred in six of seven patients whose arteries were left undisturbed.     

Ophthalmologic manifestations of internal carotid artery dissection

PURPOSE: To report the ophthalmologic symptoms and signs associated with extracranial internal carotid artery dissection. METHODS: One hundred forty-six consecutive patients with extracranial internal carotid artery dissection were evaluted; 29 were studied retrospectively from 1972 to 1984 and 117 prospectively from 1985 to 1997. RESULTS: Sixty-two percent of patients (91/146) with extracranial internal carotid artery dissection had ophthalmologic symptoms or signs that were the presenting symptoms or signs of dissection in 52% (76/146). Forty-four percent (65/146) had painful Horner syndrome, which remained isolated in half the cases (32/65). Twenty-eight percent (41/146) had transient monocular visual loss, which was painful in 31 cases, associated with Horner syndrome in 13 cases, and described as "scintillations" or "flashing lights"-often related to postural changes or exposure to bright lights-suggesting acute choroidal hypoperfusion in 23 cases. Four patients had ischemic optic neuropathy; one had diplopia. Among the 76 patients with ophthalmologic symptoms or signs as the presenting features of carotid dissection, a nonreversible ocular or hemispheric stroke later occurred in 27, within a mean of 6.2 days (range, 1 hour to 31 days). Eighteen patients had a stroke within the first week after the onset of neuro-ophthalmic symptoms and signs, and 24 had a stroke within the first 2 weeks. CONCLUSION: Ophthalmologic symptoms or signs are frequently associated with and are often the presenting features in internal carotid artery dissection. Painful Horner syndrome or transient monocular visual loss should prompt investigations to diagnose carotid artery dissection and begin early treatment to prevent a devastating ocular or hemispheric stroke.     

Medium-term patency and anatomic changes after direct bronchial artery revascularization in lung and heart-lung transplantation with the internal thoracic artery conduit

OBJECTIVE: To examine the relationship of estrogen-induced changes in lipids and lipoproteins with alterations in the coagulation system. METHODS: Coagulation and lipid indices were measured in 31 postmenopausal women, ages 40-60 years, after a 3-month course of 0.625-mg conjugated equine estrogen. We analyzed changes in variables from baseline to 3 months using t tests for paired samples or the Wilcoxon matched-pairs signed-rank test. RESULTS: Unopposed estrogen replacement therapy produced statistically significant decreases in antithrombin-III antigen (P = .006) and activity (P = .001) and total protein S (P = .003) and a significant increase in protein C antigen (P = .017). C4b-binding protein also decreased significantly from baseline to 3 months (P < .001). Mean fibrinogen level decreased by 18.2 mg/dL, not a statistically significant change (P = .213). Estrogen produced the expected statistically significant changes in lipids and lipoproteins. Several correlations between changes in lipids and lipoproteins and coagulation indices were statistically significant. Protein C antigen and activity changes correlated directly with high-density lipoprotein cholesterol changes (r = .52, P < or = .005; r = .38, P < or = .05; respectively), and protein C antigen also correlated directly with increases in apoprotein A-I (r = .54, P < or = .005). Triglyceride changes correlated directly with changes in protein C antigen (r = .36, P < or = .05) and activity (r = .49, P < or = .005) and inversely with C4b-binding protein (r = -.58, P < or = .01). Apoprotein B was correlated with free protein S (r = .48, P < or = .01). CONCLUSIONS: Although several estrogen-induced changes may decrease atherosclerotic potential and hypercoagulability, others may promote coagulability. These divergent effects may be manipulated pharmacologically by other estrogen compounds or by the addition of various progestins.     

Stenting of symptomatic stenosis of the intracranial internal carotid artery

Sarcoidosis presenting solely as a granulomatous colitis is rare and appears identical to Crohn's disease. A 56-yr-old woman developed a Crohn's-like illness, which remitted after 5-ASA therapy. Two months later, she developed fever, adenopathy, muscle weakness, and peripheral neuropathy. A diagnosis of sarcoidosis was made after an extensive search for an infectious or rheumatological cause. This case illustrates the utility of serum angiotensin converting enzyme level in differentiating sarcoidosis from Crohn's disease.     

Pain as the only manifestation of internal carotid artery dissection

Internal carotid artery dissection is a major cause of ischemic stroke in the young. Pain is the leading symptom and is associated with other focal signs such as Horner's syndrome and painful tinnitus or with signs of cerebral or retinal ischemia. We report two patients with angiographically confirmed extracranial internal carotid artery dissection presenting with cephalic pain as the only manifestation. The first patient had a diffuse headache and a latero-cervical pain lasting for 12 days, reminiscent of carotidynia. The second patient experienced an exploding headache suggestive of subarachnoid hemorrhage, which was ruled out by computed tomography of the head and cerebrospinal fluid study. These patients demonstrate that recognition of carotid artery dissection as a cause of carotidynia and headache suggestive of subarachnoid hemorrhage may permit an earlier diagnosis and possibly the prevention of a stroke through the use of anticoagulation.     

Transcranial Doppler in the evaluation of internal carotid artery dissection

BACKGROUND AND PURPOSE: A subject with dissection of the internal carotid artery (ICA) may present with a variety of symptoms, from headache to stroke. Thus far, it has not been possible to identify the subset of patients at risk for cerebral ischemia. Because the majority of these ischemic events are secondary to embolic phenomena, we used transcranial Doppler (TCD) evaluation with emboli monitoring to study 17 consecutive patients with ICA dissection treated at Harborview Medical Center, Seattle, Wash, during a 2-year period from 1992 until 1994. METHODS: Ten patients with ICA dissection secondary to trauma and seven with spontaneous ICA dissection were diagnosed by carotid angiography and studied by TCD from the time of diagnosis through initiation of therapy. Emboli monitoring was performed in the middle cerebral artery (MCA) ipsilateral to the dissection at the initial evaluation and intermittently thereafter to ensure that the emboli stopped with treatment. RESULTS: Emboli were detected in the MCA distal to the dissection in 10 of 17 patients (59%). Patients with microemboli detected by TCD presented with a stroke (70%) much more frequently than those without emboli (14%) (P=.0498). The presence of a pseudoaneurysm did not increase the risk of either microemboli or stroke. CONCLUSIONS: We have demonstrated a high incidence of intracranial microemboli in the MCA distal to carotid dissections and a significant correlation between the presence of emboli and stroke. TCD can therefore be used as an adjunctive tool to manage patients with suspected carotid dissection and may prove useful in evaluating the efficacy of treatment in reducing microemboli and subsequent stroke.     

Stroke patterns of internal carotid artery dissection in 40 patients

BACKGROUND and PURPOSE: Internal carotid artery dissection (ICAD) is a frequent cause of ischemic stroke in young patients. Whether cerebral ischemia is of embolic or hemodynamic origin remains to be determined. Heparin is often administered in ICAD; however, a drug trial can hardly be conducted because of the low recurrence rate after the acute stage. Therefore, the best therapeutic approach should be determined on the basis of the presumed mechanism of cerebral ischemia. One way to approach the mechanism of stroke in ICAD is to determine stroke patterns. We postulated that most cortical and large subcortical infarcts (>/=15 mm) are of embolic origin and that small subcortical infarcts (<15 mm) and junctional infarcts are not. The aim of our study was to determine the stroke patterns in 40 consecutive patients with ICAD. METHODS: The patients (26 women and 14 men; mean age, 42.8 years) had a total of 65 ICADs. Seventeen patients were free of any vascular risk factor. CT scans, MRI scans, and angiographic features were analyzed by observers who were blinded to the clinical findings. RESULTS: We found 34 cortical infarcts, 25 large subcortical infarcts, 1 small subcortical infarct, and 5 junctional infarcts. CONCLUSIONS: Most infarcts related to ICAD are cortical infarcts or large subcortical infarcts; small subcortical infarcts and junctional infarcts are infrequent. Therefore, these findings suggest that most infarcts occurring in carotid artery dissection (CAD) are probably embolic rather than hemodynamic in origin. According to this presumed mechanism, anticoagulation seems a logical treatment at the early stage of CAD.     

Aortic dissection decades following internal carotid artery dissection--report of two cases

BACKGROUND: In patients with cirrhosis, portosystemic shunts allow intestinal bacteria and endotoxin to enter the systemic circulation. Endotoxemia may induce increased synthesis of nitric oxide, thereby contributing to arterial vasodilation. OBJECTIVE: To test the hypothesis that the antibiotic norfloxacin blocks the effects of nitric oxide. DESIGN: Placebo-controlled, double-blind, crossover study. SETTING: Alfred Hospital, Melbourne, Australia. PATIENTS: 9 patients with alcohol-related cirrhosis and 10 healthy controls. INTERVENTION: Norfloxacin, 400 mg twice daily, for 4 weeks. MEASUREMENTS: Peripheral blood flow was measured by using forearm venous occlusion plethysmography. RESULTS: Basal forearm blood flow was higher in patients with cirrhosis than in controls (3.69 +/- 0.27 mL/100 mL per minute and 2.47 +/- 0.40 mL/100 mL per minute; P = 0.014) but returned toward normal after norfloxacin was given (2.64 +/- 0.31 mL/100 mL of tissue per minute in patients with cirrhosis). Responses to NG-monomethyl-L-arginine were greater in patients with cirrhosis but returned to normal after norfloxacin was given. CONCLUSION: Bacterial endotoxemia in patients with cirrhosis induces increased synthesis of nitric oxide that can be corrected with norfloxacin.     

Greater contractility of internal mammary artery bifurcation: possible cause of low patency rates

Coronary artery bypass grafting using bifurcation of the internal mammary artery (IMA) has been reported to have a poor patency rate. To test the hypothesis that the contractility (tendency for spasm) is greater at the bifurcation than at the main IMA, segments of the bifurcation and the distal section of IMA taken from patients with coronary artery bypass grafts were studied in organ baths. The IMA rings were set up at a physiologic pressure. Concentration-response curves were established for norepinephrine, endothelin-1, U46619, potassium, and glyceryl trinitrate (precontracted with 10 nmol/L U46619). Contraction forces were standardized (gram per mm circumference) at a pressure of 100 mm Hg. The diameter was 1.50 +/- 0.08 mm (n = 38) for the bifurcation and 2.03 +/- 0.07 (n = 42) for the main IMA (p < 0.0001). The standardized contraction force was greater in the bifurcation than in the main IMA for norepinephrine (0.82 +/- 0.06 versus 0.54 +/- 0.1; p = 0.02) and endothelin-1 (1.07 +/- 0.11 versus 0.69 +/- 0.07; p = 0.02). No differences were seen for potassium, U46619, or glyceryl trinitrate, whereas the effective concentration that induced 50% of maximal effect for U46619 was 6.17-fold lower in the bifurcation than in the main IMA (9.14 +/- 0.28 versus 8.35 +/- 0.09 -log M; p = 0.003), indicating higher sensitivity in the bifurcation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of aprotinin on bleeding during and graft patency after coronary artery bypass grafting

The case of an incarcerated gravid fibroid uterus in a 32-year-old woman is presented. This rare complication of pregnancy is readily identified by specific symptoms, physical examination, and ultrasound findings. If the condition is undiagnosed and untreated, spontaneous abortion and preterm labor often occur.     

Isolated vagal nerve palsy associated with a dissection of the extracranial internal carotid artery

A 40-year-old man had paralysis of the right vocal cord. Imaging showed a dissection of the extracranial internal carotid artery, and physical examination disclosed paresis of the right side of the soft palate. To our knowledge, this is only the second report of carotid dissection presenting as an isolated vagal neuropathy. Most often, multiple lower cranial nerves are involved. The CT, MR imaging, and MR angiographic findings are presented and the topic is reviewed.     

Bilateral optic disk pallor after unilateral internal carotid artery occlusion

Bilateral pallor of the optic disks was observed in a 52-year-old man after dissection of an internal carotid artery. Diffuse pallor of the ipsilateral optic disk reflected infarction of the ipsilateral optic nerve and "bow-tie" atrophy of the contralateral optic disk reflected infarction of the ipsilateral optic tract. The findings were due to an occlusion of the internal carotid artery proximal to the origin of the ophthalmic artery, resulting also in insufficiency in the area of supply of the anterior choroidal artery.     

Head pain associated with sixth-nerve palsy: spontaneous dissection of the internal carotid artery

BACKGROUND: Iodixanol (Visipaque, Nycomed Imaging AS, Oslo, Norway) is a new non-ionic and isotonic X-ray contrast medium. OBJECTIVE: To assess its safety and efficacy for paediatric excretory urography. MATERIALS AND METHODS: A three-centre trial in which 72 patients were randomised into three parallel groups: iodixanol 270 mgI/ml, iodixanol 320 mgI/ml and iohexol 300 mgI/ml (Omnipaque, Nycomed Imaging, Oslo, Norway). Doses ranging from 1 to 3 ml/kg never exceeded 50 ml. Pulse rate and blood pressure were recorded before, during, and after the examination. Adverse events, including injection associated discomfort, were recorded during and up to 24 h after the examination. The diagnostic quality of the urograms was assessed on a four-level scale. RESULTS: No serious adverse event occurred in any of the three groups. One patient who was given iodixanol 270 mgI/ml, three who received iodixanol 320 mgI/ml, and one who received iohexol 300 mgI/ml experienced transient adverse events. More than 80 % of the urograms in all three groups were rated "good" or "excellent". CONCLUSION: Iodixanol, either 270 mgI/ml or 320 mgI/ml, is well tolerated and efficacious for excretory urography in children.     

Early postoperative flow rates after internal thoracic artery grafting for the left coronary artery system

OBJECTIVE: The low perioperative flow rates of internal thoracic artery (ITA) conduits have been regarded as a limitation of their use in critical coronary situations with a high myocardial blood demand. To clarify whether these restrictions are justified, early postoperative flow rates were determined. METHODS: Following bilateral ITA grafting, 48 of 106 patients (April 1993-September 1994) underwent recatheterization. Subsequent to control angiography between days 8 and 12, 20 of these patients were studied by intravascular Doppler techniques applied for ITA grafts supplying the left anterior descending artery (LAD) and branches of the circumflex system (CX) (n = 20). Doppler spectral analysis allowed for determination of the average peak velocity and diastolic-systolic velocity ratio. Vascular diameters were assessed by simultaneously performed quantitative angiography and mean flow rates were calculated. All parameters were recorded at rest and following selective stimulation with nitroglycerin (0.2 mg) and papaverine (12.5 mg) to evaluate the graft flow capacity. RESULTS: Baseline values of average peak velocity at rest were 24.6 +/- 11.5 cm/s for ITA-LAD conduits and 21.9 +/- 6.8 cm/s for ITA-CX pedicles. Following dilative stimulation with papaverine, a significant increase in average peak velocities were obtained for both locations (ITA-LAD: 47.3 +/- 17.1 cm/s, ITA-CX: 42.3 +/- 11.8 cm/s). The application of nitroglycerin had a similar effect (ITA-LAD: 42.6 +/- 15.3 cm/s, ITA-CX: 40.3 +/- 10.7 cm/s). The vascular diameters of ITA conduits remained unchanged on nitroglycerin stimulation, whereas papaverine effected significant dilatation in both locations. Flow rates at rest were not significantly different (ITA-LAD: 51.0 +/- 34.2 ml/min, ITA-CX: 44.7 +/- 16.4 ml/min) and maximal flow increase was observed following papaverine stimulation of the LAD conduits (116.1 +/- 90.6 ml/min). Dilative stimulation effected an increase in diastolic-systolic velocity ratios from average values at rest in a range between 34% and 41.7% for both groups and substances. CONCLUSIONS: The basic blood flow in functioning ITA grafts appears to be similar in conduits supplying the LAD and marginal branches. Flow rates between 50 and 60 ml/min at rest should meet myocardial demands, even in the LAD position. Increased flow rates were predominantly based on higher flow velocities with an increased diastolic flow proportion. Enlargement of the graft diameter may exert additional effects, at least following papaverine stimulation at a particular concentration.