Blood blisterlike aneurysms of the internal carotid artery

1. The effects of ryanodine, procaine, and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) on noradrenaline (NA)- and caffeine-induced contractions of human vas deferens were investigated. 2. In the presence of nifedipine (1 microM), NA ( 100 microM) evoked biphasic contractions. Caffeine (20 mM) evoked repeatable tonic contractions. 3. Ryanodine (30 microM) inhibited the initial but not the secondary component of NA contractions. Procaine (1 and 10 mM) inhibited both components. Contractions induced by caffeine were unaffected by ryanodine or procaine. 4. The calmodulin antagonist W-7 (100 microM) reduced, in a reversible manner, both components of NA-induced response. Caffeine-induced contractions were also reduced in most preparations (8 of 11). In all preparations, contractions induced by caffeine were markedly inhibited after the washout of W-7. Higher doses of W-7 (300 microM) induced an increase in basal tension. 5. These results indicate that NA contracts the longitudinal muscle of human vas deferens by a ryanodine-sensitive calcium-induced calcium release (CICR) mechanism and, in addition, a ryanodine-insensitive pathway: both are sensitive to procaine. In contrast, contraction induced by caffeine is mediated by a pathway that is atypically insensitive to either ryanodine or procaine. The sensitivity of NA- and caffeine-induced contraction to W-7 suggests a role for calcium and its interaction with calmodulin in the response to both agents. The paradoxical action of W-7 is discussed.     

Internal carotid artery agenesis and multiple aneurysms in the posterior communicating artery

Internal carotid artery agenesia is a rare anomaly of the embryonic development. We present a case with this anomaly and a vascular feeding of this territory out of the contralateral carotid system and the posterior vascular system. There were multiple aneurysms in the right posterior communicating artery, never described before in association with carotid agenesia, that are similar to the angiographic image of the fibromuscular dysplasia ("atypical" pattern). We review and discuss the embryonic development of this anomaly and its relationship with the hemodynamic stress and aneurysm formation.     

Spontaneous occlusion of supraclinoid aneurysms after the creation of extra-intracranial bypasses using long grafts: report of two cases

OBJECTIVE: We describe two cases of giant supraclinoid aneurysms, treated by means of saphenous vein grafting between the external carotid artery and the middle cerebral artery, which unexpectedly spontaneously occluded. CLINICAL PRESENTATION: Two patients presented with subarachnoid hemorrhage and headache, respectively. In the first case, angiography showed an aneurysm of the right internal carotid artery (ICA), which had been treated by clipping. Repeat angiography showed a giant aneurysm of the right ICA, the formation of which was probably caused by sliding of the clip that had been applied during the previous operation. The patient was operated on again, but it was impossible to exclude the aneurysm because no clear neck could be identified. In the second case, magnetic resonance imaging and cerebral angiography showed a large, partially thrombosed aneurysm of the supraclinoid segment of the left ICA. TECHNIQUE: In view of the patients' ages and the statuses of compensatory circulation, each patient underwent cerebral revascularization with a long saphenous vein graft placed between one branch of the middle cerebral artery and the external carotid artery, in anticipation of subsequent endovascular treatment of the aneurysm and/or closure of the ICA in the neck. Postoperative angiography demonstrated spontaneous occlusion of the aneurysms. CONCLUSION: Thrombosis of an aneurysm may occur spontaneously or after explorative surgery. However, it should be remembered that spontaneous occlusion of an aneurysm may be induced or favored by hemodynamic vascular alterations that take place inside the aneurysm after a high-flow extra-intracranial bypass has been created.     

Surgical treatment of internal carotid and posterior communicating artery aneurysms

Saccular aneurysms of the subarachnoid segment of the internal carotid artery (ICA) are very common. Although some of the aneurysms arising from the subarachnoid ICA have earned the reputation of easy to treat surgically, aneurysms in this region may be complex and quite difficult to repair. Even a simple aneurysm associated with the posterior communicating artery may harbor surprises for the unwary or inexperienced surgeon. This article details the pertinent anatomy of the subarachnoid internal carotid artery and associated saccular aneurysms, provides a guide to their diagnosis and surgical treatment, and briefly reviews some of the published surgical results. Pitfalls and technique tips are highlighted.     

Effect of Guglielmi detachable coils on experimental carotid artery aneurysms in primates

BACKGROUND AND PURPOSE: Clinical experience has established that intravascularly placed metal coils can be a useful treatment for cerebral vascular aneurysms. However, the mechanism by which the coils induce occlusion of the aneurysm is unclear. Appropriate use of this promising treatment modality requires basic understanding of the occlusive process. We used an animal model system of experimentally induced carotid aneurysms to investigate the initial events induced by Guglielmi detachable coils (GDCs), as well as the subsequent vascular changes induced by the coils over time. METHODS: We induced 23 aneurysms in the carotid arteries of 16 Japanese monkeys. Nineteen aneurysms were then occluded with GDCs placed via endovascular surgery; 4 aneurysms served as controls. We then used gross and microscopic pathological examination, angiography, and scanning electron microscopy to assess the effects of the GDC. RESULTS: In the first few hours after placement of the GDC in the experimental aneurysms, we observed leukocyte attachment and deposition of fibrinlike materials and other proteins. By 4 days after coil placement, leukocytes and fibroblasts were observed in the thrombus. By 2 weeks after coil placement, there was evidence of an endothelial-like covering of the coils. At 3 months after coil placement, we observed development of an arterial media in the occluded aneurysms. CONCLUSIONS: The GDCs initiated a cellular response within several hours of aneurysm occlusion. By 2 weeks after coil placement, endothelialization was proceeding, and by 3 months after occlusion, remodeling of the aneurysm had progressed to produce a media-like structure in the former aneurysm.     

Surgical results and the related topographic anatomy in paraclinoid internal carotid artery aneurysms

Paraclinoid internal carotid artery aneurysms arising between the roof of the cavernous sinus and the origin of the posterior communicating artery are of considerable interest with regard to their anatomical variations and technical surgical challenges. Twenty-seven patients with 30 paraclinoid aneurysms were treated surgically through pterional intradural approach. Neck clipping was performed in 22 (73%) of the 30 aneurysms, coating in seven, and trapping in one. The surgical outcome was excellent in 24 patients (24/27, 89%), with two patients showing ipsilateral partial visual field defect (2/27, 7%). There was one death (4%) due to infarction after unintended carotid artery trapping. The characteristic topographic anatomical features which we considered to pose technical difficulties and to be responsible for the complications or failure in neck clipping were aneurysmal dome extending into the anterior clinoid process, atheroma at the neck, multiple paraclinoid aneurysms, ophthalmic artery originating at the neck, and marked supero-medial shift of the C2 segment of the carotid artery. pre-operative depiction of the topographical anatomy around the paraclinoid aneurysm is essential but not always possible on the basis of conventional angiography. Magnetic resonance or three-dimensional computerized tomographic angiography, and their axial source imaging, were useful in delineating the topography with unusual aneurysmal growth, overlap of aneurysm with the parent artery, and uncommon variations of the surrounding structures.     

Endovascular stent treatment of cervical internal carotid artery aneurysms with parent vessel preservation

BACKGROUND: Aneurysms involving the cervical portion of the internal carotid artery (ICA) frequently result from prior trauma or dissection. CASE DESCRIPTIONS: Two patients are reported with cervical internal carotid artery aneurysms. In both cases, disease involving the contralateral ICA precluded safe treatment of the aneurysms by ICA occlusion. Endovascular stents placed across the diseased portion of the artery resulted in thrombosis of the aneurysm with preservation of the parent artery. CONCLUSION: Endovascular stent placement should be considered for treatment of aneurysms involving the cervical ICA when preservation of the parent vessel is necessary.     

Clinical analysis of internal carotid artery aneurysms with reference to classification and clipping techniques

OBJECTIVE: To determine the differential effects of parental major depression (MDD) on psychopathology of childhood, adolescent, and early-adult onset in offspring. METHOD: One hundred eighty-two offspring from 91 families in which one or more parents or neither parent had MDD were followed for more than 10 years and blindly reassessed by means of a structured diagnostic instrument. RESULTS: Parental MDD is associated with increased risk in offspring of childhood-onset MDD (eightfold), anxiety disorder (threefold), conduct disorder (fivefold), and early-adult-onset MDD (fivefold) but not adolescent-onset MDD, where there is a marked increase in risk, particularly in girls, regardless of parental diagnosis. These findings were not explained by parental comorbidity, but the association with MDD was explained by parental age at onset of MDD--there was a 13-fold increase in childhood-onset MDD and a 7-fold increase in adult-onset MDD in offspring of parents with MDD of early (before age 30 years) onset. CONCLUSION: Childhood- and early-adult-onset MDD may be etiologically homogeneous and familial subtypes. The reason for the high incidence of adolescent-onset MDD, particularly in girls, regardless of parental diagnosis, needs to be determined. The childhood offspring of depressed parents are a potential target for evaluation, especially when the parent had an early-onset depression.     

Interlocking-clipping technique for giant aneurysms of the internal carotid artery: technical case report

OBJECTIVE AND IMPORTANCE: Direct clipping of giant intracranial aneurysms is sometimes difficult. A unique technique using multiple fenestrated clips for closing a giant aneurysm is described. CLINICAL PRESENTATION: A 65-year-old woman presented with a 10-month history of headache and gait disturbance. Cerebral angiography disclosed an unruptured giant aneurysm of the right internal carotid artery. INTERVENTION: Surgical exposure confirmed the presence of a giant aneurysm with the splaying and incorporation of the parent artery and a number of perforating arteries originating from the dome. Four angled and three straight fenestrated clips were applied in tandem to the aneurysm to reconstruct the parent artery and preserve the perforating vessels. Through their blades and heads, the closely arranged clips were successfully interlocked. CONCLUSION: This "interlocking-clipping" technique is a modification of the tandem clipping technique. The aim of this approach is to enhance closing pressure and allow a more stable "seating" of the clips in giant cerebral aneurysms.     

Noninavasive angiography for the diagnosis of carotid artery disease using Doppler ultrasound (carotid artery Doppler)

To detect stenosis in the carotid artery with a bidirectional continuous-wave Doppler ultrasound device, the following noninvasive procedure, applied on 800 patients and compared with 249 angiograms of 186 patients, has proved to be about 90% reliable. Measurements of flow signals were taken over the terminal branches of the ophthalmic artery (supratrochlear and supraorbital arteries) and averaged. Compression of superficial temporal and facial arteries revealed flow direction and common carotid artery compression revealed the supplying blood vessel and the effectiveness of the circle of Willis. Measurements over the common carotid arteries were used to evaluate peripheral resistance. A set of eight criteria was used; the diagnostic value of each criterion was calculated by comparing 138 pathological Doppler findings in 123 patients with the angiograms. If reverse flow direction in supratrochlear or supraorbital artery was used alone, only 43% correct diagnoses would have resulted. A more severe stenosis is not necessarily correlated with a more weighted criterion; a subset of criteria is less efficient than the combination of all criteria. Application during 32 extracranial endarterectomies on 28 patients informed the surgeon immediately about the hemodynamic effect of the surgical intervention. Rethrombosis was diagnosed in two patients by postoperative Doppler examination.     

The microsurgical treatment of large and giant aneurysms of the internal carotid artery located parasphenoidally

Internal carotid aneurysms in the ophthalmic area presents a challenge in cerebrovascular neurosurgery. The study was undertaken to provide evidence for the application of intravascular aspiration during direct surgical interventions and to outline their variants used at the N. N. Burdenko Institute of Neurosurgery. The study included 4 (3 females and 1 male) patients with large and giant internal carotid aneurysms of parasphenoidal site who were treated at the Institute. Clipping of the aneurysmal neck was made by employing intravascular blood aspiration from the aneurysm. The technique proved to be effective in proximal monitoring the carotid artery at surgery. It substantially reduced aneurysmal blood flow and wall tension, thus favouring aneurysmal dissection to make clipping.     

Biomechanics of human common carotid artery and design of novel hybrid textile compliant vascular grafts

Entorhinal cortex lesion (ECL) leads to anterograde degeneration of perforant path axons and is known to induce a rapid and intense reaction of astrocytes and microglial cells in the deafferented dentate gyrus. Phagocytosis of degenerating axons involves the establishment and maintenance of cell-matrix and cell-cell interactions by activated glial cells. It was thus our aim to investigate whether the process of axon phagocytosis is accompanied by the expression of adhesion molecules on activated microglial cells or reactive astrocytes, as such molecules mediate bot cell-matrix and cell-cell interactions. We found that the integrin adhesion molecules leukocyte function antigen-1 (LFA-1), very late antigen-4 (VLA-4), and the ligand for LFA-1, intercellular adhesion molecule-1 (ICAM-1), were expressed on microglial cells accumulating in the outer molecular layer of the deafferented dentate gyrus. This upregulation of adhesion molecule expression on microglial cells showing morphological criteria of activation occurred rapidly following ECL, reached its peak at 3 days post lesion (dpl), and gradually returned to control levels after 9 dpl. Astrocytes were never labeled by antibodies directed against these adhesion molecules. Prelabeling of the perforant path with a fluorescent tracer and subsequent ECL led to phagocytosis of fluorescent-labeled axonal debris by cells that were located in the outer molecular layer and showed typical microglial morphology. Double-fluorescence labeling demonstrated that microglial cells engaged in the phagocytosis of axonal debris expressed LFA-1, VLA-4, and the LFA-1-ligand ICAM-1. In conclusion, our results demonstrate that anterograde degeneration of perforant path axons results in adhesion molecule expression on activated microglial cells engaged in axon phagocytosis. The expression of such molecules could represent a mechanism that retains activated microglia in areas of axonal degeneration and perhaps enables the interaction of microglial cells with each other or with other immunocompetent cells.     

Endosaccular occlusion of basilar artery bifurcation aneurysms using electrically detachable coils

Thirteen patients with basilar artery bifurcation aneurysms, treated by electrothrombosis using electrically detachable coils, are presented. Nine of them presented after hemorrhage, two with mass effect, and two were found coincidentally with other ruptured aneurysms. Selection for endovascular therapy was based on the following criteria: 1) poor clinical condition (Hunt and Hess III-V); 2) high surgical risk; 3) age and poor medical condition; 4) morphological features (small necked aneurysms). With endovascular Guglielmi detachable coils aneurysm occlusion ranging from 70-100% was achieved in all cases. All five small necked and two large broad necked aneurysms were totally occluded. Two large aneurysms had a 95% occlusion and two other large aneurysms were 90% occluded. In another patient with a large broad based aneurysm only an 80% occlusion was achieved, because of tortuosity of the vertebrobasilar system. Our last patient, who presented as grade V clinically, was partially treated with a 70% aneurysmal occlusion. The clinical results were excellent in 10 and good in 2. The only poor outcome was seen in the grade V patient. There was no morbidity or mortality related to therapy. The only complication was an asymptomatic dissecting aneurysm at the origin of the vertebral artery. Angiographic follow up time ranged from 6 to 20 months with a mean of 9 months. Four patients were treated too recently to have their angiographic follow up at 6 months. Two patients were lost to follow up. Clinical follow up ranged from 1 to 17 months with a mean of 8.9 months. The analysis of our cases clearly shows that aneurysms, which were densely packed with coils, especially if small necked, were less likely to be reperfused and showed a longlasting stable result. Large broad based aneurysms were more likely to be reopened by blood flow after the first procedure, especially if loosely filled with coils, and needed up to 3 interventions to achieve a satisfying result, whereas later in the series a high percentage rate of occlusion was seen after the first procedure. We consider now also a less than 100% occlusion acceptable, because most of the aneurysms will rupture at the dome, which was occluded in all our cases. We conclude, that this new endovascular method is a viable alternative in the treatment of posterior circulation aneurysms with a high surgical risk, in old patients and those in poor clinical and medical condition.     

Late occlusion of microvascular vein grafts in replantation

Two cases are described in which patients presented 16 and 17 years, respectively, after complete or incomplete amputation/replantation of the arm. In case 1, the patient complained of coldness, pain, and tingling in the replanted arm in the previous 24 hours and noticed that his fingers had gone white. Arteriography and subsequent surgery revealed obliteration of the vein graft (inserted in the distal brachial artery) by neointimal thickening and atherosclerotic plaque, which was confirmed in a subsequent morphologic examination. In case 2, the patient presented with discomfort and a pulsatile swelling on the inner aspect of his upper arm. Arteriography and surgery revealed an aneurysm in the previously inserted vein graft in the brachial artery, with some atherosclerotic degeneration. Both vein grafts were successfully replaced with a fresh autologous vein graft and the patients remain well several years later. The 2 cases suggest that as part of replantation surgery of a limb, it is essential to maintain postoperative clinical monitoring for signs of graft degeneration in all patients with long-term vein graft insertion.     

Prevention of focal intimal hyperplasia in rat vein grafts by using a tissue engineering approach

The present study focused on the role of blood flow in the formation of focal intimal hyperplasia in vein grafts, as well as the development of an engineering approach that can be used to eliminate disturbed blood flow and prevent blood flow-related focal intimal hyperplasia. A rat vein graft model was constructed by interposing a jugular vein into the abdominal aorta with end-to-end anastomoses. Locally disturbed flow was identified by analyzing particle streak-lines in methyl salicylate-cleared and perfused vein grafts in vitro with a physiological Reynolds number. At day 10, 20, and 30 after surgery, focal intimal hyperplasia of the vein grafts was examined using a histological approach and the density of alpha-actin positive cells was determined using immunohistological and fluorescent approaches. Results showed that apparent eddy blood flow formed at the proximal, but not at the distal, end of the vein grafts due to graft-host diameter mismatch and local geometric distortions, and was associated with apparent focal intimal hyperplasia. The thickness of the alpha-actin positive layers of the proximal vein grafts was significantly higher than that of the distal grafts (192 +/- 27 vs. 94 +/- 18 microm, 278 +/- 55 vs. 124 +/- 20 microm, and 288 +/- 24 vs. 131 +/- 23 microm for day 10, 20. and 30, respectively). The density of the alpha-actin positive cells, however, was similar between the proximal and the distal regions (3569 +/- 361 vs. 3285 +/- 343 cells/mm2, 5540 +/- 650 vs. 5376 + 887 cells/mm2, and 5465 +/- 791 vs. 5278 +/- 524 cells/mm2 for day 10, 20, and 30, respectively). When eddy blood flow was eliminated by matching the graft-host diameters using a tissue engineering approach, the average thickness of the alpha-actin positive layers of the proximal (71 +/- 15, 86 +/- 16, and 85 +/- 14 microm for day 10, 20, and 30, respectively) and the distal vein grafts (68 +/- 13, 80 +/- 14, and 79 +/- 13 microm for day 10, 20, and 30, respectively) was reduced significantly. The density of the alpha-actin positive cells was also reduced significantly in the proximal (2946 +/- 359, 3261 +/- 295, 3472 +/- 599 cells/mm2 for day 10, 20, and 30, respectively) and in the distal regions (3151 +/- 511, 3466 +/- 687, 3593 +/- 688 cells/mm2 for day 10, 20, and 30, respectively). The thickness of the alpha-actin positive layers and the density of the alpha-actin positive cells were not significantly different between the proximal and distal regions of the engineered vein grafts at each observation time. These results suggest that eddy flow may develop in vein grafts and may facilitate the formation of focal intimal hyperplasia, and the vascular tissue engineering approach developed in this study may be used to prevent blood flow-related focal intimal hyperplasia in vein grafts.     

Value of CT angiography for postoperative assessment of patients with iliac artery aneurysms who have received endovascular grafts

OBJECTIVE: To determine the pathologic outcome in human immunodeficiency virus (HIV)-seropositive individuals with nonspecific bronchoalveolar lavage (BAL) cytology. STUDY DESIGN: The study group consisted of 126 cytologically negative or nonspecific BAL specimens from HIV-seropositive adults. Concurrent microbial cultures and transbronchial biopsies, as well as subsequent pulmonary cytology, lung biopsy or autopsy results were reviewed. Additionally, the cytologic morphology of specimens from patients found to have a potential bacterial pathogen was reviewed. RESULTS: In the 126 cases with nonspecific BAL cytology, a potential pulmonary pathogen was identified from a concurrent or subsequent pathologic specimen in 27% of cases, while no pathogen was identified in 73% of cases. Bacteria and fungi were the most common pathogens identified. Microbial cultures alone identified the pathogen in 59% of cases, while transbronchial biopsy added information in only 9%. Specimens with marked acute inflammation often yielded bacterial pathogens on microbial culture. CONCLUSION: A potential pulmonary pathogen can be identified in 27% of HIV-seropositive individuals with negative BAL cytology using other diagnostic modalities. Bacterial pathogens are most common and are usually identified by microbial culture. Marked acute inflammation in a BAL specimen is often associated with bacterial pneumonia.     

Giant fusiform basilar artery aneurysm: endovascular treatment by flow reversal in the basilar artery

We report a patient presenting with subarachnoid haemorrhage due to rupture of a giant fusiform aneurysm of the proximal basilar artery. The aneurysm was successfully treated by reversing blood flow in the basilar artery by balloon occlusions of both vertebral arteries proximal to the posterior inferior cerebellar artery origins. Substantial thrombosis and regression of the aneurysm was evident 4 months later.     

Biodegradation of glutaraldehyde-tanned human umbilical vein grafts

A retrospective analysis of the long-term behavior of 111 glutaraldehyde-tanned human umbilical vein (HUV) grafts implanted between September 1977 and December 1993 was conducted. A total of 81 patients, with a mean age of 68.7 years, received the grafts and were followed up for between 1 and 131 months. The 5-year primary cumulative patency rate for above-knee femoropopliteal bypass was 83.1%, whereas that of other bypasses was 60.9%. An aneurysm of the graft was defined as a physically apparent localized dilatation, with diffuse ectasia being excluded. There were 11 aneurysms found in 9 grafts, 2 of which arose at the factory-made suture lines. The accumulated incidence of aneurysms had reached 21.9% by the 6th year. One aneurysm compressed the graft and resulted in limb-threatening ischemia and another resulted in frank rupture. Moreover, reinforcement of the mesh could not prevent aneurysm development, the repair of which is mandatory due to the risk of rupture and acute thrombosis. The HUV grafts showed an acceptable patency rate in the above-knee location, but the incidence of aneurysm formation after 5 years was abnormally high. Thus, both the risks and benefits of HUV grafts must be taken into account when considering their clinical application.