Conjoined lumbosacral nerve roots: observations on three cases and review of the literature.

Lumbosacral nerve root anomalies are a rare group of congenital anatomical anomalies. Various types of anomalies of the lumbosacral nerve roots have been documented in the available international literature. Generally speaking, these anomalies may consist of a bifid, conjoined structure, of a transverse course or of a characteristic anastomized appearance. Firstly described as an incidental finding during autopsies or surgical procedures performed for lumbar disk herniations and often asymptomatic, lumbosacral nerve root anomalies have been more frequently described in the last years due to the advances made in radiological diagnosis (metrizamide myelography and CT, MRI). Our study comprised three patients with conjoined lumbosacral nerve roots, representing 0.25% of a total of 1200 patients who underwent lumbosacral CT/MRI procedures in the Addolorata Hospital and in the Service of Neuroradiology of the University of Rome "La Sapienza" during the last three years (March 2001-March 2004). We report our experience with three cases of conjoined lumbosacral nerve roots and analyze the most important literature on this topic. MR imaging is a better diagnostic procedure (in comparison to CT) for the differentiation of nerve root anomalies and, in particular, coronal sections furnish a precise definition of the profile of the conjoined/enlarged rootlets. In fact, the accurate information derived from MRI of multiple planes may be priceless for the preoperative and diagnostic evaluation of lumbosacral nerve root anomalies.

Role of electrothrombosis in aneurysm treatment with Guglielmi detachable coils: an in vitro scanning electron microscopic study.

BACKGROUND AND PURPOSE: In the 1990s, the introduction of the Guglielmi detachable coil (GDC) system in clinical practice was followed by extensive clinical use of this endovascular device in the treatment of brain aneurysms. This technology is based on electrothrombosis and electrolytic detachment of platinum coils. Despite the extensive use of this treatment technique, the role of electrothrombosis has not been fully investigated and clarified. An in vitro electron microscopic study of human blood was performed to elucidate the role that electrothrombosis might play in triggering the biologic response of thrombosis of the aneurysmal sac. METHODS: Human blood from five patients was used to fill plastic containers in which GDCs had been deposited. These five patients had subarachnoid hemorrhage and were similar in age and clinical presentation. Electron microscopic studies were performed on GDCs that had been electrically charged and on GDCs that had not. RESULTS: All electron microscopic studies revealed that the electrically charged GDCs were covered by blood elements and fibrin adherent to the surface of the coil. Noncharged GDCs did not have deposits or adhesions of these blood constituents. CONCLUSION: These findings demonstrated that passage of electric current through the GDC induces attraction of blood constituents. This attraction may trigger a thrombotic reaction on the surface of the coil. The greater the time of current application, the more pronounced the cellular reaction and the deposition of fibrin and blood cells on the GDC.

Long saphenous-vein grafts for extracranial and intracranial internal carotid aneurysms amenable neither to clipping nor to endovascular treatment.

BACKGROUND: In the treatment of patients with unclippable, uncoilable internal carotid artery aneurysms it may be necessary to use high-flow bypass grafts. The indications, surgical techniques and complications are discussed. METHODS: During a 12- year period, 20 saphenous vein grafts were performed in 20 patients. The 20 aneurysms were located in the prepetrous or intrapetrous internal carotid artery in 7 cases, the intracavernous in 9 and intracranial internal carotid artery in 4. All aneurysms were symptomatic. The vein graft was interposed between the internal carotid artery at the neck and the intrapetrous carotid, from the internal carotid artery at the neck to a branch of the middle cerebral artery, or from the external carotid artery and a branch of the middle cerebral artery, according to the collateral circulation assessed with a 30-minute the balloon test occlusion during electroencephalographic recording. RESULTS: Only one of the 20 grafts occluded. One patient died from a large postoperative cerebral infarction. One patient had cerebral ischemia with transient hemiparesis; and three patients had mixed aphasia that resolved completely within two weeks. Radiological follow-up monitoring was by magnetic resonance imaging, magnetic resonance angiography or digital angiography. Postoperative follow-up ranged from 1 to 12 years (mean 3.7 years). CONCLUSIONS: Our experience in this series suggests that the indications for cerebral revascularization should be widened, even to include patients with adequate collateral circulation, particularly those who have a long life expectancy.

Regression of an internal carotid artery pseudoaneurysm after therapeutic embolization of a post-traumatic carotid-cavernous fistula secondary to gunshot injury.

A case is reported of a 53-year-old woman who was hit by a bullet which penetrated the skull base and caused a left carotid-cavernous fistula of the direct type and a pseudoaneurysmal dilation of the high cervical portion of the left internal carotid artery. The fistula was successfully embolized by positioning a balloon into the fistula itself by means of the Debrun technique: unexpectedly the size of the pseudoaneurysm decreased after the embolization; the possible explanations for this event are discussed.

Computed tomography in the management of spinal cord arteriovenous malformations.

This is a report of two cases of intramedullary arteriovenous malformations (AVMs) where computed tomography (CT) was used as a complementary diagnostic investigation. CT scan features in these two cases are briefly discussed.

Benign extramedullary foramen magnum tumors: diagnosis by computed tomography.

This paper reports two cases of benign extramedullary tumors of the foramen magnum studied by computed tomography (CT). The first case was a neurinoma; the second was a meningioma. Several different CT findings allowed a correct preoperative diagnosis of the location and nature of the tumors. In view of the invasiveness of traditional diagnostic methods and of the encouraging, although limited, experience of the present cases, the role of CT in the diagnosis of these lesions is promising.