Carlo Bortolotti

Are parenchymal AVMs congenital lesions

A long-held dogma in neurosurgery is that parenchymal arteriovenous malformations (AVMs) are congenital. However, there is no strong evidence supporting this theory. An increasing number of documented cases of de novo formation of parenchymal AVMs cast doubt on their congenital nature and suggest that indeed the majority of these lesions may form after birth. Further evidence suggesting the postnatal development of parenchymal AVMs comes from the exceedingly rare diagnosis of these lesions in utero despite the widespread availability of high-resolution imaging modalities such as ultrasound and fetal MRI. The exact mechanism of AVM formation has yet to be elucidated, but most likely involves genetic susceptibility and environmental triggering factors. In this review, the authors report 2 cases of de novo AVM formation and analyze the evidence suggesting that they represent an acquired condition.

Endovascular management of intracranial dural arteriovenous fistulae.

Endovascular embolization is the primary therapeutic modality for intracranial dural arteriovenous fistulae. Based on access route, endovascular treatment can be schematically divided into transarterial, transvenous, combined, and direct/percutaneous approaches. Choice of access route and technique depends primarily on dural arteriovenous fistulae angioarchitecture, pattern of venous drainage, clinical presentation, and location. Individualized endovascular approaches result in a high degree of cure with a reasonably low complication rate.

Aneurysms Associated with Brain Arteriovenous Malformations

SUMMARY: Brain arteriovenous malformations are frequently associated with the presence of intracranial aneurysms at a higher-than-expected incidence based on the frequency of each lesion individually. The identification of intracranial aneurysms in association with AVMs has increased due to improvement in diagnostic techniques, particularly 3D and superselective conventional angiography. Intracranial aneurysms may confer a higher risk of hemorrhage at presentation and of rehemorrhage in patients with AVMs and therefore may be associated with a more unfavorable natural history. The association of AVMs and intracranial aneurysms poses important therapeutic challenges for practicing neurosurgeons, neurologists, and neurointerventional radiologists. In this report, we review the classification and radiology of AVM-associated intracranial aneurysms and discuss their clinical significance and implications for treatment.

Thrombosed giant intracavernous aneurysm with subsequent spontaneous ipsilateral carotid artery occlusion

SummaryWe report a case of a 47-year-old man with a giant thrombosed aneurysm of the right cavernous internal carotid artery who initially presented with headache, double vision and trigeminal numbness. He experienced subsequent asymtomatic proximal occlusion of the parent vessel, revealed by follow-up angiography. This case illustrates the possibility that a giant thrombosed aneurysm may exert enough compression upon the parent vessel to induce flow stasis with resultant intraluminal thrombosis progressing to occlude the entire parent artery.

Emergent endovascular treatment with direct carotid puncture for exsanguinating carotid blowout syndrome

AbstractIntroduction: Carotid Blowout Syndrome (CBS) carries an exceedingly high mortality rate. Various established endovascular techniques are successful in treating less acute CBS, but exsanguinating patients with hemodynamic compromise continue to pose a significant clinical challenge.n Methods: We report a 53-year-old male with squamous cell carcinoma of the anterior tongue presented with a sentinel hemoptysis followed by a massive oral hemorrhage. The patient suffered a cardiac arrest secondary to acute blood loss, from which he was successfully resuscitated.n Results: An occlusion technique is presented involving direct carotid puncture for successful treatment of hemodynamically unstable, exsanguinating patients.n Conclusion: This technique accomplishes rapid arrest of exsanguination, minimal hemorrhage site manipulation, and successful carotid occlusion.

Recurrent Brain Arteriovenous Malformations (AVMs): A Systematic Review

OBJECTIVEnRisk factors for the recurrence of surgically excised brain arteriovenous malformations (AVMs) are poorly understood. In addition, ideal follow-up imaging paradigms to catch AVM recurrences are not well defined. We present a systematic review on risk factors for the recurrence of surgically resected AVMs and identify potential theories of recurrence.nnnMETHODSnA literature search was performed by a reference librarian, and after screening, 14 case reports and 16 case series were left for inclusion in the review. All possible data were abstracted by 2 authors, and the results were tabulated and descriptive statistics (mean, range; and proportions) were reported. No formal statistical analysis was performed as part of this study.nnnRESULTSnSystematic review of the literature revealed 73 patients with a surgically resected AVM that recurred. The average age of first AVM presentation was 13.8 years, and most patients presented with hemorrhage (90%). After angiographically confirmed complete surgical resection, average time to AVM recurrence was 4.2 years. Rate of recurrence was 2.7% in adult series or case reports (nxa0= 8). When we analyzed only pediatric case reports or series (nxa0= 12), the average rate of recurrence was 9.5% but was as high as almost 14% in a series with compulsory short-term follow-up serial imaging. Four (5.5%) patients experienced re-recurrence of AVM after complete surgical excision of first AVM recurrence.nnnCONCLUSIONSnAVM recurrence after complete surgical resection is a recognized risk that occurs primarily in children. Follow-up imaging within 1 year of surgery is strongly indicated for pediatric patients with surgically resected AVMs, even with postoperative angiographically confirmed complete excision.

Unruptured Versus Ruptured AVMs: Outcome Analysis from a Multicentric Consecutive Series of 545 Surgically Treated Cases

BACKGROUNDnRecent literature strongly challenged indications to perform preventive surgery in unruptured arteriovenous malformation (AVM) claiming that invasive AVM treatment is associated with a significant risk of complications and thus conservative management may be a preferable alternative in many patients. On the other hand, the recent improvement of surgical instrumentation and treatment strategies (both surgical and interventional) yielded better outcomes than those achieved only a decade ago. Therefore, even among specialists, a wide variety of opinions, concerning the treatment of unruptured AVM, can be found.nnnMETHODSnThis multicenter retrospective study analyzes a consecutive series of 545 surgically treated AVMs in 10 different hospitals in Italy.nnnRESULTSnPatients with AVMs treated after hemorrhage had an unfavorable (modified Rankin Scale score >1) outcome in more than one third (37.69%) of the cases. Conversely, with proper indications, unruptured AVMs treated preventively have a good outcome in 93.8% of cases, increasing to 95.7%, with no death, if only Spetzler-Martin grades 1-3 are considered (P < 0.05). Outcomes on discharge significantly (P < 0.05) improve at 6 months with the disappearance of many of the initial neurologic deficits that turn out to be transient.nnnCONCLUSIONSnIn unruptured low-risk AVMs (Spetzler-Martin grades 1-3), over time, the risk of surgery-associated neurologic deficits becomes lower than that linked to spontaneous hemorrhage, with a crossover point at 6.5 years. Because the average bleeding age is less than 45 years, preventive surgery can be advocated to safeguard the patient and overcome the risks associated with the natural history of AVMs.

Spinal Arteriovenous Vascular Malformations in Patients with Neural Tube Defects

BACKGROUND AND PURPOSE: Neural tube defects, such as tethered cord, intradural lipoma, or myelomeningocele may coexist with spinal vascular malformations. The coexistence of these 2 rare entities is suggestive of a causal relationship between them, which may lead to further understanding of their pathogenesis. We present a series of 6 patients with epidural spinal arteriovenous fistulas associated with neural tube defects. MATERIALS AND METHODS: We retrieved cases of spinal vascular malformations associated with neural tube defects seen at our institution. The clinical presentation, MR imaging/MRA and angiographic imaging, treatment outcomes, and long-term neurologic outcomes were analyzed. Descriptive statistical analyses are reported. RESULTS: Six patients with epidural arteriovenous fistulas and neural tube defects were included in this study. The mean age at presentation was 42 years, and the most common presenting symptoms were lower extremity weakness followed by sensory disturbances and bladder/bowel dysfunction. In most cases (5/6), the fistulas were located at the sacral level. All cases were fed by the lateral sacral artery (6/6). Four patients had prior spine surgery, but the fistula was in the operative bed in 2 cases. All fistulas were extradural with secondary intradural venous drainage. Five patients underwent transarterial embolization with Onyx, and 1 patient had a treatment-related complication. CONCLUSIONS: It is conceivable that there is a pathophysiologic link between neural tube defects and development of spinal vascular malformations. Delayed neurologic deterioration or high conus signal in a patient with a neural tube defect should suggest the possibility of such an association.

Seeding of a cavernous angioma with Mycoplasma hominis: Case report [1] (multiple letters)

To the Editor: We have read with great interest the article by House et al. (4). We agree that static or slow venous flow within a preexisting cavernous angioma (CA) contributed to focal bacterial deposition and abscess formation in this particular patient. The finding of a disproportionate cerebral edema surrounding the malformation is a good clue, as suggested by the authors, of a secondary infection that should be carefully checked at operation. However, in general, the problem may be more intriguing, and not only “superinfection” but also direct promotion (de novo or growth) of the malformation should be considered. Fender et al. (3) described a de novo genesis of two CAs after bacterial meningitis and subdural empyema. They suggested that thrombophlebitis of small veins and ensuing venous hypertension could be initiating factors promoting a capillary proliferation evolving into a CA. This is a sort of “convergent” disease leading to the formation of a de novo malformation (9). The origin of CAs is multifactorial: genetic causes, irradiation, and infection (viral or bacterial) have been implicated and may be variably connected (2). Viruses may be significant cofactors for angiogenic processes and activation of cerebrovascular malformations. We are particularly interested in infective pathogenesis of CAs (7). The main issue is whether the infection might be involved directly, and not through an indirect mechanism, in the formation of the angioma. The polyoma virus, a member of the papovavirus family, is associated with the induction of multiple CAs in immunodeficient rats (2). It is probably not coincidental that some de novo CAs occur in children irradiated for leukemia and lymphomas (5, 6). We found the deoxyribonucleic acid of cytomegalovirus, a member of the herpesvirus family, by in situ hybridization in the intercavernous matrix of some CAs (7); it is noteworthy that the cytomegalovirus infection of fibroblasts may induce an endothelial cell growth factor and promote angiogenesis (1). This may partly correlate with the expression of angiogenic factors observed by several authors in CAs (8). Strong angiogenic activity of the human immunodeficiency virus was recently suggested in an arteriovenous malformation (10). The activity of basic fibroblast growth factor and vascular endothelial growth factors is augmented in human immunodeficiency virus-infected patients, and antiretroviral therapy may inhibit the virusinduced angiogenic stimulation (10). In conclusion, cerebrovascular malformations, and CAs in particular, may be a target of infection that may interfere with the development of the lesion: this issue has scarcely been investigated but constitutes a promising field of study and research.