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PubMed2005

Plasmalemmal vesicle-associated protein (PLVAP) is expressed by tumour endothelium and is upregulated by vascular endothelial growth factor-A (VEGF).

Vascular endothelial growth factor-A (VEGF) is an important regulator of vascular permeability. In preclinical studies, VEGF induces endothelial fenestrations in pre-existing and neo-vasculature, while inhibition of VEGF leads to a reduction in endothelial fenestrations. Recently, vascular regression in response to VEGF inhibition has been shown to correlate with the presence of endothelial fenestrations. Plasmalemmal vesicle-associated protein (PLVAP) is believed to be a component of diaphragmed endothelial fenestrations, but a direct relationship with VEGF signalling has not been established. The aim of this study was to characterize the expression pattern of PLVAP and investigate whether PLVAP is a transcriptional target of VEGF signal transduction. The expression pattern of PLVAP was characterized in normal and neoplastic human tissues by in situ hybridization and/or immunohistochemistry. The role of VEGF signal transduction in the regulation of PLVAP expression was investigated in vitro using receptor-selective engineered forms of VEGF, a neutralizing monoclonal antibody against VEGF, and inhibitors of downstream signalling pathways. PLVAP mRNA and protein were widely expressed in the endothelium of normal and neoplastic tissues. In cultured endothelial cells, VEGF signalling through receptor 2 stimulated expression of PLVAP total RNA and protein. This induction could be blocked with an anti-VEGF monoclonal antibody and by inhibitors of phosphatidylinositol 3-kinase (LY294002) or p38 mitogen-activated protein kinase (SB203580), but not by PD98059, a mitogen-activated protein/extracellular signal-regulated kinase 1 inhibitor. These data show that PLVAP is more widely expressed in the vasculature of normal tissues than previously thought and that it is expressed in the vasculature of most human tumours. We suggest that PLVAP is a downstream target of VEGF signalling. This work solidifies the association between VEGF and the appearance and maintenance of fenestrations by providing a potential mechanistic link.

Carrier Proteins↗
PubMed1996

Differential permeability of blood microvasculatures in various sympathetic ganglia of rodents.

The ultrastructure of capillaries and their permeability to lanthanum ion and horseradish peroxidase (HRP) in various rodent sympathetic ganglia were investigated in this study. Electron microscopic observation revealed that most capillaries surrounding the principal neurons in these ganglia were of the continuous (non-fenestrated) type, while the fenestrated capillaries were consistently associated with the small granule-containing (SGC) cells in rat and hamster superior cervical ganglia and the coeliac-mesenteric ganglia (CMG) complex. Both of the capillaries surrounding the principal neurons and adjacent to SGC cells in various gerbil sympathetic ganglia or in rat and hamster thoracic ganglia were of the non-fenestrated type. After lanthanum perfusion, lanthanum tracer was limited to the blood-vessel lumen but was apparently obstructed by the tight junctions of capillaries. No lanthanum was visible in the extravascular space surrounding the principal neurons of rodent superior cervical and thoracic ganglia. By contrast, lanthanum extravasation was observed in the luminal, abluminal and perivascular surface of capillaries in the CMG complex and near SGC cells in the superior cervical ganglion. Injecting HRP showed that all blood vessels in various sympathetic ganglia were impermeable to HRP. HRP-DAB reaction product was limited to the lumen of capillaries, blocked by tight junctions and obstructed by fenestral diaphragms of fenestrated capillaries close to SGC cells. We conclude that: (1) the capillaries surrounding the principal neurons in rodent superior cervical and thoracic ganglia are more restrictive to HRP and lanthanum ion than those anywhere in the CMG complex or in regions containing SGC cells of superior cervical ganglia; (2) according to the results of lanthanum and HRP experiments, the existence of different blood-barrier properties are present among different rodent sympathetic ganglia or within the same ganglion.

Animals↗
PubMed1992

Effect and distribution of intravenously injected 125I-endothelin-1 in rat kidney and lung examined by electron microscopic radioautography.

The morphological effect of endothelin-1 (ET-1) and the distribution of endothelin-binding sites on the kidney and lung was investigated ultrastructually by intravenous injection of [125I]-ET-1 into rats. About 10% decrease of the diameter of glomeruli was observed at 10 min after the injections of ET-1 or [125I]-ET-1 (1.3-2.4 nmole/kg). When localization of [125I]-ET-1 in the kidney was examined by light and electron microscopic radioautography, silver grains were preferably localized on the fenestrated endothelial cells of glomeruli and peritubular capillary endothelial cells. Some grains were also localized on the interdigitating processes of urinary tubules. Quantitative analysis of silver grains in the glomeruli showed that 83% of grains were located on the fenestrated endothelial cells, 12% on the podocytes of visceral cells, and 5% on mesangial cells at 10 min. After 60 min, 50% of silver grains were incorporated into the cytoplasm of fenestrated endothelial cells. In contrast to glomeruli, silver grains were rare on the arteries and large arterioles. However, a few silver grains were often observed on the smooth muscle cells of small arterioles (8-20 microns in diameter). In the lung, 70% of silver grains were located on the alveolar capillary endothelial cells. These results indicate the abundance of ET receptors on the glomerular fenestrated endothelium, peritubular fenestrated endothelium and alveolar capillary endothelium.

Animals↗
PubMed2000

Shunt-independent surgical treatment of middle cranial fossa arachnoid cysts in children.

The best operative intervention for children with arachnoid cysts remains the subject of controversy. Recent reports stress that craniotomy for cyst fenestration is associated with a low incidence of morbidity and mortality and may leave the child shunt-independent. Among a total of 66 intracranial arachnoid cysts operated on in the authors' department from 1985 to 1997, 44 cases (67%) were located in the middle cranial fossa. A higher incidence in the first decade of life (53 cases) and a marked male predominance (45 cases) were recognized. Headache, cranial deformities, symptoms of raised intracranial pressure, and seizures constituted the most frequent features of the clinical presentation. To determine which treatment provides the greatest benefit with the lowest incidence of complications, the records of the 44 patients with arachnoid cysts in the middle cranial fossa were reviewed. The mean age of these patients was 4.6 years (range 0-16 years). Different types of initial surgical procedures were performed. In 33 patients with middle cranial fossa arachnoid cysts (MCFAC) the initial surgery took the form of craniotomy with excision of the cyst walls and fenestration into the basal cisterns. Shunting procedures were performed in 9 patients: cysto-peritoneal shunts (CPS) were placed in 4 patients and ventriculo-peritoneal shunts (VPS), in 3 patients, and cyst excision was performed in addition to CPS in 2 patients. Excision of the cyst membrane alone without fenestration was performed in 2 patients. The initial treatment was successful in terms of reduced symptoms and decreased cyst size, with no additional treatment needed for the cyst, in 79% (26/33) of patients who had undergone excision of the cyst walls and fenestration into the basal cisterns, compared with 66% (6/9) of patients who had undergone shunting procedures. Cyst membrane excision was not successful in any of the patients who underwent this procedure alone. No significant difference in morbidity was noted between these different treatment options. On follow-up CT scan and MRI, cysts of types I and II (Galassi classification) exhibited a steady tendency to reduction or obliteration. These results confirm that radical excision of the outer and inner membranes of the cyst wall with fenestration into the basal cistern is a safe and effective shunt-independent procedure for MCFAC, especially for those of types I and II.

Adolescent↗
PubMed2004

Laparoscopic palliation of polycystic liver disease.

The role of laparoscopic surgery in the management of polycystic liver disease (PCLD) is not well defined. The authors hypothesized that laparoscopic fenestration for PCLD relieves symptoms caused by polycystic liver disease. In this study, 11 patients underwent 20 laparoscopic cyst fenestration operations as treatment for symptoms of their PCLD. Symptoms leading to surgery were pain and pressure in 15 (75%) and early satiety in 12 (60%) patients. The median hospital stay was 1 day. The symptoms resolved postoperatively in all the patients. An additional laparoscopic fenestration was required in six (55%) patients for recurrent symptoms. The average time to reoperation was 22 +/- 16 months. Two patients required hepatic transplantation. Initial symptom resolution occurred in all the patients undergoing redo fenestration. The authors conclude that laparoscopic fenestration for PCLD is safe, results in minimal "down" time and relieves the symptoms caused by PCLD. Symptomatic relief usually is temporary, and repeat surgery is required for recurring symptoms in half of the patients.

Adult↗
PubMed2004

Surgical therapy of symptomatic arachnoid cysts - an outcome analysis.

BACKGROUND: Arachnoid cysts may present with various symptoms and in different locations. Optimal treatment is still controversial, although cyst fenestration or shunt insertion are recognized as standard procedures. In this retrospective analysis the authors sought to determine which factors influence the outcome after surgery of symptomatic arachnoid cysts. METHODS: 37 patients (24 male, 13 female, mean age 40.2 years) were treated within a ten year period in our institution. Mean follow-up was 39 months; follow-up was done on an ambulatory basis. For analysis patient charts were reviewed and cranial CT scans or MR investigations were examined to determine pre- and postoperative cyst volumes. Clinical outcome was graded into four subgroups using a scale based on the patients self-rating of success. Different factors were studied concerning their influence on outcome. FINDINGS: Fenestration was performed in 28 cases, cysto-peritoneal or cysto-atrial shunting in 9 cases. A favourable outcome (subgroups 3 and 4) was achieved in 19 of 28 patients (fenestration) and in 6 of 9 patients (shunting), respectively. Mean reduction of the cyst volumes was 58% after fenestration and 74% after shunting revealing both methods to be effective. Degree of cyst volume reduction correlated significantly with clinical outcome. Patients with infratentorial cysts had more often a favourable outcome. Headache as the only symptom did not influence outcome. CONCLUSIONS: Surgery of symptomatic arachnoid cysts resulted in favourable outcome in two thirds of the patients. Both standard procedures, fenestration and shunting, are equally effective for treatment. Factors that influence outcome are the rate of volume reduction and cyst location.

Adolescent↗
PubMed1993

Optic nerve sheath decompression for visual loss in patients with acquired immunodeficiency syndrome and cryptococcal meningitis with papilledema.

Visual dysfunction developing in association with acquired immunodeficiency syndrome (AIDS) can be multifactorial. Two patients with this syndrome and cryptococcal meningitis had papilledema and visual loss. Both were treated by optic nerve sheath fenestration. One patient had bilateral nonsimultaneous optic nerve sheath fenestrations; visual function improved in one eye. The other patient had bilateral visual improvement after a unilateral optic nerve sheath fenestration. Cryptococcal organisms were present in the dural sheath specimens of both patients despite ongoing therapy with antifungal medication. Postoperative orbital infectious complications did not occur. Autopsy examination of one patient showed that the sites of fenestration were patent. Medical treatment of cryptococcal meningitis associated with AIDS has a guarded prognosis. Optic nerve sheath fenestration offers a treatment alternative for papilledema and visual loss that occur with cryptococcal meningitis.

AIDS-Related Opportunistic Infections↗
PubMed1995

Univentricular repair. Early and midterm results.

A total of 202 patients (62 with tricuspid atresia and 140 without tricuspid atresia) underwent univentricular repair at our unit from January 1990 to September 1994. Of these patients, 182 had nonfenestrated and 20 had fenestrated interatrial baffles. Early mortality was 15.9% (29/182) in the group with nonfenestrated baffles and 5% (1/20) in the group with fenestrated baffles. The follow-up period ranged from 2 to 58 months. Seven late deaths occurred, and five patients were lost to follow-up. Of 160 patients who have been evaluated in the outpatient department in the past 3 months, 142 (88.75%) required no cardiac medicines and were in functional class I. Risk factors analyzed for early mortality and significant effusion were age, preoperative diagnosis, type of Fontan modification, cardiopulmonary bypass time, aortic crossclamp time, pulmonary artery size, associated pulmonary arterioplasty, takedown of systemic-pulmonary artery shunt, and pulmonary artery debanding, along with the Fontan operation. Bypass time exceeding 120 minutes was associated with a higher early mortality (12/47 vs 18/155; p = 0.0187). Bypass time exceeding 120 minutes (p = 0.0456) and aortic crossclamp time exceeding 60 minutes (p = 0.0278) were associated with significant postoperative effusion. Other factors were not associated with any significantly increased risk for early mortality or postoperative effusions. Fenestration of the interatrial baffle appeared to decrease early mortality, although the numbers are too small to be statistically significant. The prevalence of effusions did not differ significantly between the group with fenestrated baffles and the group without fenestrated baffles.

Cardiopulmonary Bypass↗
PubMed1999

Endoscopic surgery for monoventricular hydrocephalus.

BACKGROUND: Monoventricular hydrocephalus is usually treated with extrathecal shunting. However, today endoscopic fenestration of the septum pellucidum seems to be a very useful and less invasive technique. METHODS: Five patients with monoventricular hydrocephalus have been treated with neuroendoscopic techniques. In three cases with an excluded lateral ventricle due to contralateral shunt overdrainage, the normal-sized ventricle was first cannulated and fenestration of the septum pellucidum from the normal to the enlarged lateral ventricle was performed. RESULTS: Complete remission of intracranial hypertension symptoms and decrease in size of the enlarged ventricle were observed in all five patients. CONCLUSIONS: Endoscopic fenestration of the septum pellucidum is the technique of choice for treating monoventricular hydrocephalus. We advise first cannulating the normal lateral ventricle and then performing a septostomy from it to the enlarged ventricle. This approach allows one to easily recognize the protruding septum pellucidum and perform fenestration without difficulty using a direct trajectory. In exceptional cases of choroid plexus cyst obstructing one foramen of Monro, fenestration of the cyst wall is sufficient.

Adolescent↗
PubMed2003

The Fontan-operation: from intra- to extracardiac procedure.

PURPOSE: For treatment of univentricular heart, the Fontan operation has been established as the definitive palliation. The current controversy is mainly based on the high incidence of arrhythmias after an intra-atrial lateral tunnel Fontan operation. METHODS: From January 1995 until April 2002, 46 children underwent a Fontan-type operation with or without a small fenestration. In 33 patients (group I) an intracardiac tunnel and in 13 patients (group II) an extracardiac conduit procedure was performed. PRINCIPAL FINDINGS: There was no perioperative mortality. All patients showed postoperative a significant increase of arterial oxygen saturation, from 76 to 86% after surgery with fenestration, or to 90.5% without fenestration respectively. In patients with fenestration procedure, the saturation rose to 90% after closure of fenestrations 9 to 12 months after operation. CONCLUSIONS: Modified Fontan operations can be performed in normothermia on the beating heart with acceptable mortality. The extracardiac conduit Fontan procedure has the benefits of less surgical injury and a higher intraoperative flexibility.

Adolescent↗
PubMed1997

Management of the univentricular connection: are we improving?

OBJECTIVE: To assess the impact of the bidirectional cavopulmonary shunt, total cavopulmonary connection, and baffle fenestration on outcome of the Fontan operation in our unit. METHOD: We reviewed 123 bidirectional cavopulmonary shunts and 264 Fontan operations performed from 1980 to 1995. Analysis of pulmonary artery size (right and left main and lower lobe branches) before and after bidirectional cavopulmonary shunt was performed. Outcome of the Fontan operation was analysed in various time periods to assess the effect of prior bidirectional cavopulmonary shunt, use of the lateral tunnel, and fenestration. RESULTS: Operative risk for the bidirectional cavopulmonary shunt was 4% (CI = 2-10%) with a survival of 89% (CI = 83-95%) at 36 months. Probability of conversion to Fontan operation at 36 months was 49% (CI = 38-61%). Pulmonary artery size (Nakata and lower lobe indices) fell after bidirectional cavopulmonary shunt (P = 0.0006). Fontan risk dropped from 8.5% (1980-1987) to 1.8% (1988-1995) (P = 0.02), coinciding with the use of the bidirectional cavopulmonary shunt. There was no further risk reduction after introduction of the lateral tunnel and baffle fenestration, although these comparisons are limited by relatively small numbers. Duration of hospital stay related to pleural effusions was lowest for patients with a fenestrated lateral tunnel operation (P < 0.05). CONCLUSION: The bidirectional cavopulmonary shunt is a suboptimal stimulus for pulmonary artery enlargement, but may reduce the risk of Fontan operation in selected children. Fenestrated lateral tunnel operations have reduced the duration of postoperative pleural effusions.

Adolescent↗
PubMedDate not supplied

Percutaneous creation of acute type-B aortic dissection: an experimental model for endoluminal therapy.

PURPOSE: To evaluate the feasibility of a percutaneously created type-B aortic dissection as an experimental model for percutaneous therapy. This model was used to evaluate the hemodynamic effects of single-balloon fenestration of the intimal flap. MATERIALS AND METHODS: Acute type-B dissections were created in descending aortae of 15 swine via a femoral (n = 6) or carotid (n = 9) approach. The initial subintimal tear was made with use of a Colapinto needle. The dissections were extended to a predefined position in the aorta. The proximal and distal tears were balloon dilated. The mural flap was balloon fenestrated in six animals, just above the celiac artery. Aortograms were obtained to establish the presence and extent of the dissection. Manometry was performed in both lumina to evaluate the hemodynamics of the dissected aorta and the effects of balloon fenestration in this model. Pathologic specimens were also examined. RESULTS: Creation of dissection was successful in 11 of 15 animals, with six developing true lumen narrowing (group A). The other five animals (group B) had flow in both lumina without evidence of true lumen narrowing. After the creation of a single-balloon fenestration in the group A swine, the arteriograms revealed no evidence of blood admixture between the true and false lumina, and there was no change in the intravascular pressures. Examination of the explanted aortae showed a more extensive circumferential dissection in group A animals as compared with group B. CONCLUSION: The percutaneously created acute type-B aortic dissection is a feasible model for experimentation. The hemodynamics of the aorta did not change after single-balloon fenestration in this model.

Aortic Dissection↗
PubMed1987

The anionic sites at luminal surface of peritubular capillaries in rats.

Anionic sites have been demonstrated in the basement membranes of peritubular capillaries. The anionic barrier function of peritubular capillary wall has been ascribed to these sites. Fenestrated capillaries in other organs have anionic sites in the endothelial cell glycocalyx and at the luminal surface of the fenestral diaphragms. The purpose of this study was to map anionic sites at the luminal surface of peritubular capillaries and to assess whether a concentration gradient for albumin exists across the endothelium. Partial chemical characterization of these anionic sites was done by in vivo enzymatic degradation. The difference in distribution of albumin following enzyme digestion was also studied. The binding of cationized ferritin to the luminal surface indicated that the rat peritubular capillaries have anionic sites along the entire luminal surface of the endothelial cell, including the fenestral diaphragms. Partial biochemical characterization of these sites shows that the sites in the glycocalyx are mainly from neuraminic acid, while the fenestral diaphragms have mainly heparan sulfate proteoglycans. Intravascular albumin extended to the endothelial luminal plasmalemma and to the luminal surface of fenestral diaphragms. Digestion with heparitinase was associated with the leakage of albumin outside the capillary wall. These findings suggest that the anionic surface of fenestrae constitutes a charge barrier of the peritubular capillaries.

Animals↗
PubMed2000

Treatment of osteoarthritis of the elbow: a comparison of open and arthroscopic debridement.

PURPOSE: To assess the effectiveness of open and minimally invasive techniques in the debridement of osteoarthritis of the elbow, we compared the Outerbridge-Kashiwagi (O-K) procedure with an arthroscopic modification in which arthroscopic debridement and fenestration of the olecranon fossa was performed. TYPE OF STUDY: The study took the form of a nonrandomized control trial in which subjects were allocated to a treatment depending on the hospital of presentation. MATERIALS AND METHODS: Assessment using the Mayo Clinic elbow function chart enabled comparison of the outcome in 18 cases treated by the O-K procedure and 26 patients treated by arthroscopic debridement and fenestration of the olecranon fossa. Mean follow-up was 35.3 months (minimum 12 months). Of the patients treated by the O-K procedure, 14 were men and 4 were women with a mean age of 55 years. In 83% of patients, the diagnosis was primary osteoarthritis, with the remainder post-traumatic arthritis. The patients treated by arthroscopic debridement and fenestration of the olecranon fossa included 24 men and 2 women with a mean age of 46 years, and a diagnosis of primary osteoarthritis in 91% and post-traumatic arthritis in the remainder. No patients were excluded from the study or refused to be included. RESULTS: Both procedures were shown to be effective, with no major complications. Patients treated by arthroscopic debridement and fenestration of the olecranon fossa achieved better relief of pain (P <.10), whereas those patients undergoing the O-K procedure achieved significantly greater improvement in range of flexion (P <.05). No difference between the procedures in terms of patient-perceived overall effectiveness of the surgery was found. CONCLUSIONS: In conclusion, in the treatment of osteoarthritis of the elbow, arthroscopic debridement and fenestration of the olecranon fossa may be a more suitable procedure when painful symptoms predominate. In contrast, the O-K procedure is a significantly better procedure for improving the range of flexion where this is a particular problem.

Adult↗
PubMed2001

Leptin induces vascular permeability and synergistically stimulates angiogenesis with FGF-2 and VEGF.

Most endocrine hormones are produced in tissues and organs with permeable microvessels that may provide an excess of hormones to be transported by the blood circulation to the distal target organ. Here, we investigate whether leptin, an endocrine hormone, induces the formation of vascular fenestrations and permeability, and we characterize its angiogenic property in the presence of other angiogenic factors. We provide evidence that leptin-induced new blood vessels are fenestrated. Under physiological conditions, capillary fenestrations are found in the leptin-producing adipose tissue in lean mice. In contrast, no vascular fenestrations were detected in the adipose tissue of leptin-deficient ob/ob mice. Thus, leptin plays a critical role in the maintenance and regulation of vascular fenestrations in the adipose tissue. Leptin induces a rapid vascular permeability response when administrated intradermally. Further, leptin synergistically stimulates angiogenesis with fibroblast growth factor (FGF)-2 and vascular endothelial growth factor (VEGF), the two most potent and commonly expressed angiogenic factors. These findings demonstrate that leptin has another new function-the increase of vascular permeability.

Adipose Tissue↗
PubMed2000

Morphological changes of capillaries in the rat soleus muscle following experimental tenotomy.

We examined the structural changes of capillaries in the rat soleus muscle 4, 7, 14, and 35 days after experimental limb tenotomy. In the soleus muscles after tenotomy, muscle fibres degenerated and some of them were destroyed; the muscle did not seem to recover until the 35th day. On the 14th day, some small muscle fibres, probably regenerating muscle fibres, started forming within the basal-lamina tube and remained after necrosis of a pre-existing muscle fibre. Most capillaries at each stage were of the continuous type. However, about 10% of the capillaries around degenerated muscle fibres at days 4, 7 and 14 consisted of endothelial cells with a small number of fenestrae bridged by a single-layered diaphragm. On the 14th day, capillaries around small regenerating muscle fibres also often had a small number of fenestrations. Even on the 35th day, capillaries occasionally had fenestrations. Additionally, some of the fenestrated capillaries formed small pores at the fenestrated portion of the endothelial cells. The untreated muscles contained only continuous capillaries. These findings suggest that fenestrations in the endothelial cells may occur in intramuscular capillaries not only around degenerated muscle fibres but also around regenerating muscle fibres after tenotomy.

Achilles Tendon↗
PubMed1999

Endoscopic treatment of symptomatic septum pellucidum cysts: with some preliminary observations on the ultrastructure of the cyst wall: two technical case reports.

OBJECTIVE AND IMPORTANCE: We describe two patients with symptomatic septum pellucidum cysts managed by endoscopic fenestration. In each case, tissue from the cyst wall was studied to define the origin of the cyst wall and fluid. CLINICAL PRESENTATION: The patients, a 6-year-old boy and a 42-year-old man, each presented with headaches and a syncopal episode. Imaging studies demonstrated large septum pellucidum cysts with obstruction of the foramina of Monro. INTERVENTION: The patients underwent endoscopic transventricular cyst fenestration with a 4-mm steerable fiberscope. The fenestrations were created to allow communication with the right and left lateral ventricles. In one patient, adhesions between the cyst wall and the foramen of Monro were lysed with endoscopic monopolar cautery. Tissue from the cyst walls was removed for examination by electron microscopy. Postoperatively, the headaches and syncopal episodes resolved in both patients. CONCLUSION: Endoscopic fenestration of symptomatic septum pellucidum cysts produces immediate relief of the mass effect of the cyst and resolution of associated symptoms. Cannulation of the lateral ventricle before cyst fenestration prevents inadvertent injury to the fornices, thalamus, internal capsule, caudate nucleus, and septal and thalamostriate veins. The endoscopic approach allows the surgeon to ensure communication within the ventricular system, thus avoiding placement of a shunt. Preliminary ultrastructural analysis indicates that the cyst walls derive from the septum pellucidum rather than the choroid plexus or arachnoid. The cellular machinery necessary for fluid secretion was identified in some specimens.

Adult↗
PubMed1991

Duplication of the vertebro-basilar system.

During the examination of 75 fixed brains and 2086 vertebral angiograms we encountered two cases of fenestration of the vertebral artery and two cases of partial duplication of the basilar artery. In the first case, an 81 year old male, there was fenestration, of the basilar artery at the union of the two vertebral arteries. The fenestration was 9mm long with no associated vascular disease. The other partial duplication of the basilar artery was observed in the upper portion of the artery in a 54 year old male patient investigated angiographically for subarachnoid haemorrhage. The fenestration of the third case was demonstrated in the intracranial part of the right vertebral artery of a 50 year old female patient during digital subtraction angiography for subarachnoid haemorrhage. In the fourth case, the fenestration was found angiographically at the atlanto-axial level in the extracranial portion of the left vertebral artery in a 37 year old female patient with subarachnoid haemorrhage from an arteriovenous malformation in the left cerebral hemisphere. The embryonic, histological and radiological implications of the duplication are discussed.

Adult↗