An experimental study of vascular damage in estrogen-induced embolization

Neurological Complications in Pregnancy and the Puerperium: Methodology for a Clinical Diagnosis

Neurological complications in pregnancy and the puerperium deserve particular attention from specialists due to the worsening of the clinical picture for both the mother and the fetus. This narrative review of existing data in the literature aims to analyze the most common "red flag symptoms" attributable to neurological complications such as pre-eclampsia (PE), eclampsia, HELLP syndrome, posterior reversible encephalopathy syndrome (PRES), cerebral vasoconstriction syndrome (RCVS), stroke, CVS thrombosis, pituitary apoplexy, amniotic fluid embolism and cerebral aneurysm rupture, with the aim of providing a rapid diagnostic algorithm useful for the early diagnosis and treatment of these complications. The data were derived through the use of PubMed. The results and conclusions of our review are that neurological complications of a vascular nature in pregnancy and the puerperium are conditions that are often difficult to diagnose and manage clinically. For the obstetrics specialist who is faced with these situations, it is always important to have a guide in mind in order to be able to unravel the difficulties of clinical reasoning and promptly arrive at a diagnostic hypothesis.

Cerebral cavernous malformation: Management and outcome during pregnancy and puerperium. A systematic review of literature

INTRODUCTION

Cerebral cavernomas malformations (CCMs) are vascular malformations that occur with an incidence of 0,4-0,8 % in general population. The most feared complication is cerebral hemorrhage. Currently there are no guidelines for pregnant women with CCMs. Some authors claimed that many physiological changes related to pregnancy could be linked to an high risk of rupture and bleeding of the cerebral cavernoma. However, more recent studies highlight that the presence of cerebral cavernomatosis is not a contraindication for pregnancy and that the risk of bleeding is similar in pregnant and in non-pregnant women.

AIM OF THE STUDY

The purpose of our work is to analyze, through the study of controversial findings in literature, all the information currently available trying to establish a common approach for management of women with cerebral cavernomatosis in pregnancy, during childbirth and in the puerperium.

FINDINGS

In accordance with existing literature, pregnancy does not appear to be a significant risk factor for the worsening of clinical manifestations associated with the presence of CCMs. Vaginal delivery is not contraindicated in patients with CCMs and there is no indication to perform cesarean section to reduce the incidence of hemorrhage. The only indication for neurosurgery of CCMs in pregnancy is the presence of rapidly progressive symptoms and should be postponed to the puerperium if arises after 30 weeks. The puerperium is a critical time for the woman with cavernomas for the possibility of bleeding and clinical observation must be continued.

CONCLUSION

The patients with a diagnosis of a CCMs can have a pregnancy without any particular risk to themselves and the fetus but should be addressed to highly specialized obstetrics center to assesses the initial individual risk related to their pathology and to follow the pregnancy.

Cavernous angioma presenting as pregnancy-related seizures

PURPOSE

To determine the reason that one-quarter to one-third of epileptic women experienced an increased number of seizures during pregnancy. The cause of this increase is not always clearly understood and the principle emphasis of the literature is on the pregnancy-associated changes of anticonvulsant pharmacokinetics.

METHODS

Two patients presented with recurrent seizures occurring only during pregnancy. Both had MRI findings typical of cavernous angiomas of the temporal lobe.

RESULTS

In addition to changes in anticonvulsant pharmacokinetics, potential mechanisms underlying the exacerbation of seizures from a vascular malformation during pregnancy include effects of estrogen on temporal structures critically involved in epileptogenesis and changes within the malformation itself secondary to direct actions of estrogen and the hemodynamic changes of pregnancy.

CONCLUSIONS

The possibility of an occult lesion such as cavernous angioma should be considered for seizures occurring during pregnancy. Even in the presence of a normal CT scan, an MRI investigation should be pursued, despite the ill-defined fears of MRI in pregnancy.

Embolic materials for endovascular treatment of cerebral lesions

Recently developed soft microcatheters can be maneuvered endovascularly into the brain, permitting treatment of lesions without conventional neurosurgery. Progress in biomaterial science has contributed significantly to the development of this new therapeutic modality termed intravascular neurosurgery or interventional neuroradiology. Although embolic materials play an important role, ideal materials have yet to be devised. Various embolic materials in clinical use are reviewed, such as cyanoacrylates, ethylene-vinyl alcohol copolymer mixtures, Ethibloc, ethanol, estrogen, poly(vinyl acetate), cellulose acetate polymer, poly(vinyl alcohol), gelatin sponges, microfibrillar collagen, surgical silk sutures, detachable balloons, and coils. The materials are reviewed in the context of treatment application for various brain lesions, such as arteriovenous malformations, cerebral aneurysms, and head and neck tumors. Further developments in biomaterial polymer science can bring about progress against brain diseases.

Should meningiomas involving the cavernous sinus be totally resected?

BACKGROUND

The surgical strategy for meningiomas involving the cavernous sinus (CS) is still controversial because of the difficult surgical approach and the risks of injury to the cranial nerves or the internal carotid artery. We evaluated the efficacy of subtotal removal of meningiomas involving the CS following chemical embolization, preserving cranial nerve functions.

METHODS

We analyzed the histology, embolization material, recurrence rate, and neurologic complications in 19 fresh cases with meningioma involving the CS, who received subtotal removal surgery and were followed over 1 year. Patients were 6 men and 13 women aged from 30 to 69 years (mean, 52.2 years) on admission. All patients received preoperative chemical embolization of the feeding arteries to reduce intraoperative bleeding. In the 11 earlier patients, we used estrogen (Est) as the embolization material, but changed to estrogen with 25% alcohol+polyvinyl acetate (Est+PVac) for the latter 8 patients.

RESULTS

Fourteen patients were recurrence free after 1-16 (6.5 +/- 5.5) years. The performance status of the survivors was good. Five patients, including two cases of malignant meningioma, developed recurrence, with a mean recurrence-free period of 1.7 +/- 0.5 years. Patients who received embolization with Est showed a higher recurrence rate than Est+PVac.

CONCLUSIONS

These results suggest that subtotal resection following Est+PVac embolization is a safe and effective strategy for this tumor.

Successful treatment of an arteriovenous malformation by chemical embolization with estrogen followed by conventional radiotherapy

A case of the successful treatment of a thalamic arteriovenous malformation (AVM) by chemical embolization with conjugated estrogen followed by conventional radiotherapy is described. A 22-year-old woman suddenly developed headache, nausea, and consciousness disturbance. Computed tomographic scans revealed left thalamic and ventricular bleeding. Angiograms disclosed a left thalamic AVM with a maximum diameter of 2 cm. The AVM was fed mainly by the left medial posterior choroidal artery and drained into the basal vein. Chemical embolization with 300 mg of conjugated estrogen via a leak balloon catheter was carried out. Although the size of the nidus of the AVM was unchanged immediately after embolization, it became smaller 9 days later. In spite of the further reduction in size, the AVM still existed 2 years later. Conventional radiotherapy with a total dose of 30 Gy was performed. Follow-up angiograms 40 months after radiotherapy demonstrated disappearance of the AVM. This case report suggests progressive and stable embolizing capabilities of chemical embolization with conjugated estrogen and its suitableness for following radiotherapy, including stereotactic radiosurgery.

Surgical excision of giant cerebellar hemispheric arteriovenous malformations following preoperative embolization. Report of two cases

The authors present two cases of giant cerebellar hemispheric arteriovenous malformation (AVM) managed with staged preoperative embolization and surgical resection. A new embolization technique is described, combining injection of estrogen alcohol and polyvinyl acetate into AVM's by superselective catheterization of feeding arteries. Polyvinyl acetate proved to be an ideal liquid embolic material; because it polymerizes quickly and remains in a gelatinous state after injection, there was no difficulty in cutting and retracting the obliterated AVM during surgery. Intraoperative digital subtraction angiography was useful for confirming complete excision of the large and complex AVM.

Histopathological studies of a new liquid embolization method using estrogen-alcohol and polyvinyl acetate. Experimental evaluations with a model of cortical arterial cannulation in the canine brain

This experimental report evaluates the histopathological effects of a new embolization method using estrogen-alcohol (E-A) and polyvinyl acetate solution (PVac) as tested on 21 mongrel dogs. Three other animals treated with normal saline served as controls. All agents were introduced through an isolated cortical artery. Estrogen-alcohol induced immediate occlusion of small vessels (less than 20 microns), and then progressive obstruction of larger ones (200-300 microns) within several days. Animals treated with PVac showed vascular obliteration (greater than 100 microns) and moderate chronic fibrosis. The effects of embolization using E-A followed by PVac were found to have the combined advantages of both materials, showing diffuse occlusion of the vascular network with less tissue reaction. Hyalinization of embolized vessels with extensive fibrosis occurred afterward. For 6 weeks there was no evidence of recanalization or foreign body giant cell reaction. This study shows that E-A and PVac are capable of producing vascular occlusions with only mild tissue reaction. Because they are easily controllable and have no adverse effects, they may be suitable for intravascular application in the central nervous system.

Transvenous copper wire insertion for dural arteriovenous malformations of cavernous sinus

Therapeutic embolization by means of transvenous copper wire insertion was performed in five patients with dural arteriovenous malformations (AVM's) of the cavernous sinus. In each case, angiograms had shown that the AVM's were supplied from both internal and external carotid arteries, which was thought to render complete transarterial embolization difficult. A No. 2.5 French Teflon catheter was introduced into the affected cavernous sinus through the superior ophthalmic or internal jugular vein with the aid of a flexible mini guide wire. Copper wires were pushed by the guide wire into the cavernous sinus until the disappearance or a sufficient decrease in the arteriovenous shunt was noted. The patients' symptoms resolved or improved without any severe complications. Angiography revealed complete disappearance of the lesion immediately after treatment in three cases and follow-up angiography taken within 8 months showed no arteriovenous shunt in any patient. This method is a promising treatment for dural AVM's when conventional transarterial embolization is thought to be difficult.