Biomedical subjects

Jafar J Jafar

Publications and source records attributed to Jafar J Jafar.

10 recordsLinked to original sources

PubMed2006

Revascularizing the upper basilar circulation with saphenous vein grafts: operative technique and lessons learned.

BACKGROUND: The purpose of this study was to report our operative technique and lessons learned using saphenous vein conduits to revascularize the rostral basilar circulation (ie, bypass to the posterior cerebral or superior cerebellar arteries). We also review the evolution of this technique for the treatment of vertebrobasilar insufficiency (VBI) and complex posterior fossa aneurysms. METHODS: Data were collected retrospectively for 8 consecutive patients undergoing rostral basilar circulation saphenous vein bypass grafts at our institution between 1989 and 2004 for the treatment of VBI or in conjunction with Hunterian ligation of complex posterior circulation aneurysms. The indications for treatment, pre- and postoperative neurologic status, angiographic results, operative complications, and long-term clinical outcomes were analyzed for each patient. RESULTS: With clinical and angiographic follow-up ranging from 3 months to 15 years, 7 of 8 bypasses remained patent, 3 of 3 aneurysms remained obliterated, and 4 of 5 patients with VBI experienced resolution of their preoperative symptoms. There were no surgery-related deaths, but 2 patients did experience major neurologic morbidity. The outcomes for the 217 total patients reported in the literature were as follows: 135 excellent (62%), 26 good (12%), 30 poor (14%), and 26 dead (12%). CONCLUSIONS: Despite the risk of serious neurologic complications with this procedure, when one considers the natural history of untreated patients, saphenous vein revascularization of the rostral basilar circulation remains an acceptable option. Although surgical technique has varied, patient selection criteria, graft patency, and patient outcomes have been relatively constant over the past 25 years.

Aged↗

PubMed2006

Perfusion and diffusion tensor imaging in a patient with locked-in syndrome after neurosurgical vascular bypass and endovascular embolization of a basilar artery aneurysm: case report.

OBJECTIVE AND IMPORTANCE: Locked-in syndrome is a state of preserved consciousness in the setting of quadriplegia, anarthria, and usually also includes lateral gaze palsy. It is most commonly associated with upper brainstem infarction variably sparing the third cranial nerve nucleus. There are likely many etiologies that contribute to this clinical syndrome. These are incompletely understood, and the syndrome remains a rare but devastating complication that can occur after neurosurgical and neurovascular interventions. Advanced magnetic resonance imaging techniques such as perfusion and diffusion tensor imaging may help to elucidate the mechanism behind locked-in syndrome. To the authors' knowledge, there are no reports in the literature of perfusion and diffusion tensor findings in patients with this syndrome. A postprocedural case of locked-in syndrome is described with abnormalities on perfusion and diffusion tensor imaging in the absence of any changes in conventional magnetic resonance imaging. CLINICAL PRESENTATION: A 57-year-old man who presented with acute onset headache, ataxia, and other nonspecific symptoms was found on imaging to have a giant fusiform basilar artery aneurysm. INTERVENTION: A saphenous vein graft bypass between the proximal right external carotid artery and P2 segment of the right posterior cerebral artery followed immediately by endovascular embolization of the aneurysm sac and distal left vertebral artery was performed. CONCLUSION: Postprocedural angiography demonstrated patency of the bypass graft, and diffusion weighted imaging showed no evidence for acute brainstem infarction. Nevertheless, despite technically successful procedures and the absence of abnormalities on conventional magnetic resonance imaging, the patient developed quadriplegia and anarthria and remained in a locked-in state until he expired. Abnormalities were, however, seen on both perfusion and diffusion tensor imaging, where hypoperfusion, increased mean diffusivity, and decreased fractional anisotropy were observed in the ventral brainstem. The findings suggested a disruption of pontine white matter tracts. Advanced imaging techniques may allow us to image important microstructural changes that were previously not discernable and assist in the evaluation of patients with complex neurological sequelae such as locked-in syndrome.

Basilar Artery↗

PubMed2006

Intratumoral hydrogen peroxide injection during meningioma resection.

OBJECTIVE: Meningiomas, although histologically benign, pose a particular challenge to the neurosurgeon because of their extensive and exuberant vascularity. They often bleed extensively during resection until separated from their blood supply. There are a wide variety of hemostatic agents available to the neurosurgeon. Most of these means of hemostasis involve some sort of chemical, electrical, or compressive action. Although anecdotally known to be useful, the use of hydrogen peroxide as an intracranial hemostatic agent in meningioma surgery has not been formally reported. We report a technique of meningioma resection that uses intratumoral hydrogen peroxide injection, reducing the potential for blood loss and shortening resection times. METHODS: Seventy-five patients underwent resection of a meningioma using the direct intratumoral H2O2 injection technique. The locations of these meningiomas included convexity and cranial-based lesions. None of the patients underwent preoperative endovascular embolization. RESULTS: The use of this technique greatly facilitated the removal of these tumors. No evidence of air embolism occurred during Doppler surveillance and no other significant side effects attributable to H2O2 application were observed. CONCLUSION: We demonstrate a previously unreported technique of meningioma resection that uses direct intratumoral hydrogen peroxide injection, potentially reducing blood loss, shortening resection times, and obviating the need for preoperative embolization.

Cerebral Hemorrhage↗

PubMed2006

Recent steps toward a reconstructive endovascular solution for the orphaned, complex-neck aneurysm.

OBJECTIVE: The purposes of this article are to summarize recent developments and concerns in endovascular aneurysm therapy leading to the adjunctive use of endoluminal devices, to review the published literature on stent-supported coil embolization of cerebral aneurysms, and to describe our experience with this technique in a limited subgroup of problematic complex aneurysms over a medium-term follow-up period. METHODS: Between January 2003 and June 2004, 28 individuals among 157 patients with cerebral aneurysms we evaluated were identified as harboring aneurysms with exceptionally broad necks. Out of these 28 patients, 16 were treated with a combination of stents and detachable coils, preserving the parent artery. Recorded data included patient demographics, the clinical presentation, aneurysm location and characteristics, procedural details, and clinical and angiographic outcome. RESULTS: Over an 18-month period, 16 patients with large cerebral aneurysms additionally characterized by neck sizes between 7 and 14 mm were treated, using combined coil embolization of the aneurysm with stent reconstruction of the aneurysm neck. Thirteen out of the 16 aneurysms were occluded at angiographic reevaluation between 11 and 24 months (mean angiographic follow-up, 17.5 mo). There were no treatment-related deaths or clinically evident neurological complications. Thirteen patients experienced excellent clinical outcomes, with good outcomes in two patients and a poor visual outcome in one patient (mean clinical follow-up, 29 mo). A single technical complication occurred, involving transient nonocclusive stent-associated thrombus, which was treated uneventfully with abciximab. CONCLUSION: Stent-supported coil embolization of large, complex-neck cerebral aneurysms seems to provide superior medium-term anatomic reconstruction of the parent artery compared with historic series of aneurysms treated exclusively with endosaccular coils. In the near future, increasingly sophisticated endoluminal devices offering higher coverage of the neck defect will likely enable more definitive endovascular treatment of complex cerebral aneurysms and further expand our ability to manipulate the vascular biology of the parent artery.

Blood Vessel Prosthesis↗

PubMed2005

Role of uncal resection in optimizing transsylvian access to the basilar apex: cadaveric investigation and preliminary clinical experience in eight patients.

OBJECTIVE: The pretemporal approach has gained popularity for the treatment of basilar apex aneurysms. However, it requires the sacrifice of anterior temporal bridging veins to allow posterior temporal lobe retraction and, for patients with dominant pretemporal venous drainage, has the attendant risk of venous hypertension, hemorrhagic venous infarction, or seizures postoperatively. Alternatively, we have found that splitting the sylvian fissure, resecting the uncus, and applying posterolateral retraction to the medial temporal lobe provides a similar exposure to the basilar apex while preserving the anterior temporal bridging veins. To evaluate the transsylvian, trans-uncal approach to the basilar apex, we report our initial clinical results using this exposure in eight consecutive patients. A morphometric cadaveric analysis comparing this approach with the pretemporal approach was also performed. METHODS: For the clinical study, all hospital charts and imaging studies were retrospectively reviewed for patients undergoing the transsylvian, trans-uncal approach for the treatment of an upper basilar trunk aneurysm between July 2000 and July 2002. In the anatomic study, six formalin-fixed cadaver specimens were used. Two sequential exposures of the basilar apex were performed on each specimen side. First, the pretemporal exposure was performed with anteroposterior temporal lobe retraction. Next, after the temporal lobe had been allowed to return to normal anatomic position, the retractor was repositioned on the medial aspect of the temporal lobe superficial to the uncus, and a 10 x 10 x 15-mm volume of uncus was removed. Morphometric measurements were performed for each exposure. RESULTS: Four basilar bifurcation and four superior cerebellar segment aneurysms in eight consecutive patients were successfully clip-ligated by use of the transsylvian, trans-uncal approach. All patients had temporal bridging veins that were preserved, as documented by angiography and operative reports. No patient developed a venous infarction or new postoperative seizures, with a mean follow-up of 9.75 months (range, 0.5-28 mo). The cadaveric analysis revealed that in addition to providing a similar exposure of the upper basilar complex, the transsylvian, trans-uncal approach provided additional exposure of the ipsilateral posterior cerebral and superior cerebellar arteries compared with the pretemporal approach. CONCLUSION: When approaching the basilar bifurcation, the transsylvian, trans-uncal approach provides superior exposure of the ipsilateral superior cerebellar and posterior cerebral arteries compared with the pretemporal approach, while preserving the anterior temporal bridging veins. This approach is most valuable in patients with dominant temporal venous drainage or when additional exposure of the ipsilateral posterior cerebral or superior cerebellar arteries is required.

Adult↗

PubMed2003

Smaller cerebral aneurysms producing more extensive subarachnoid hemorrhage following rupture: a radiological investigation and discussion of theoretical determinants.

OBJECT: The goal of this study was to determine the relationship between aneurysm size and the volume of subarachnoid hemorrhage (SAH). METHODS: One hundred consecutive patients who presented with acute SAH, which was diagnosed on the basis of a computerized tomography (CT) scan within 24 hours postictus and, subsequently, confirmed to be aneurysmal in origin by catheter angiography, were included in this study. The data were collected prospectively in 32 patients and retrospectively in 68. The volume of SAH on the admission CT scan was scored in a semiquantitative manner from 0 to 30, according to a previously published method. The mean aneurysm size was 8.3 mm (range 1-25 mm). The mean SAH volume score was 15 (range 0-30). Regression analysis revealed that a smaller aneurysm size correlated with a more extensive SAH (r(2) = 0.23, p < 0.0001). Other variables including patient sex and age, intraparenchymal or intraventricular hemorrhage, multiple aneurysms, history of hypertension, and aneurysm location were not statistically associated with a larger volume of SAH. CONCLUSIONS: Smaller cerebral aneurysm size is associated with a larger volume of SAH. The pathophysiological basis for this correlation remains speculative.

Adult↗

PubMed2002

Interactive use of cerebral angiography and magnetoencephalography in arteriovenous malformations: technical note.

OBJECTIVE: To minimize the risks associated with treating cortical cerebral arteriovenous malformations (AVMs), we developed a technique combining functional imaging and cerebral angiography. The functional loci obtained by performing magnetoencephalography (MEG) are projected onto stereoscopic pairs of a stereotactically derived digital subtraction angiogram. The result is a simultaneous three-dimensional perspective of the angioarchitecture of an AVM and its relationship to the sensorimotor cortex. METHODS: Eight patients underwent multimodality brain imaging, including magnetic resonance imaging, functional mapping via MEG, and stereotactic angiography using a modified Compass fiducial system (Compass International, Rochester, MN). The coordinates derived by performing MEG were superimposed onto stereotactic, stereoscopic, angiographic pairs using custom-made distortion correction and coordinate transfer software. RESULTS: The magnetoencephalographic angiogram allowed simultaneous viewing of the angioarchitecture of the AVM nidus, the feeding vessels, and the draining veins and their relationship to the normal cerebral vasculature and functional cortex. This imaging technique was particularly valuable in identifying en passant vessels that supplied functional cortex and was used during the treatment of these lesions. CONCLUSION: The techniques of MEG and cerebral angiography were combined to provide simultaneous viewing of both modalities in a three-dimensional perspective. This technique can aid in risk stratification in the management of patients with cerebral AVMs. In addition, this technique can facilitate the selective targeting of vessels, thus potentially reducing the risks associated with embolization of these formidable lesions.

Adolescent↗

PubMed2002

Treatment of giant intracranial aneurysms with saphenous vein extracranial-to-intracranial bypass grafting: indications, operative technique, and results in 29 patients.

OBJECTIVE: The treatment of giant intracranial aneurysms is a challenge because of the limitations and difficulty of direct surgical clipping and endovascular coiling. We describe the indications, surgical technique, and complications of saphenous vein extracranial-to-intracranial bypass grafting followed by acute parent vessel occlusion in the management of these difficult lesions. METHODS: Between January 1990 and December 1999, 29 patients with giant intracranial aneurysms underwent 30 saphenous vein bypass grafts followed by immediate parent vessel occlusion. There were 11 men and 18 women with a mean follow-up period of 62 months. Twenty-five patients harbored aneurysms involving the internal carotid artery, 2 had middle cerebral artery aneurysms, and 2 had aneurysms in the basilar artery. Serial cerebral or magnetic resonance angiograms were obtained to assess graft patency and aneurysm obliteration. RESULTS: All 30 aneurysms were excluded from the cerebral circulation, with 28 vein grafts remaining patent. Two patients had graft occlusions: one because of poor runoff and the other because of misplacement of a cranial pin during a bypass procedure on the contralateral side. Other surgical complications included one death from a large cerebral infarction, homonymous hemianopsia from thrombosis of an anterior choroidal artery after internal carotid artery occlusion, and temporary hemiparesis from a presumed perforator thrombosis adjacent to a basilar aneurysm. CONCLUSION: With appropriate attention to surgical technique, a saphenous vein extracranial-to-intracranial bypass followed by acute parent vessel occlusion is a safe and effective method of treating giant intracranial aneurysms. A high rate of graft patency and adequate cerebral blood flow can be achieved. Thrombosis of perforating arteries caused by altered blood flow hemodynamics after parent vessel occlusion may be a continuing source of complications.

Cerebral Arteries↗

PubMed2002

Role of frameless stereotaxy in the surgical treatment of cerebral arteriovenous malformations: technique and outcomes in a controlled study of 44 consecutive patients.

OBJECTIVE: To describe a frameless stereotactic technique used to resect cerebral arteriovenous malformations (AVMs) and to determine whether frameless stereotaxy during AVM resection could decrease operative times, minimize intraoperative blood losses, reduce postoperative complications, and improve surgical outcomes. METHODS: Data for 44 consecutive patients with surgically resected cerebral AVMs were retrospectively reviewed. The first 22 patients underwent resection without stereotaxy (Group 1), whereas the next 22 patients underwent resection with the assistance of a frameless stereotaxy system (Group 2). RESULTS: The patient characteristics, AVM morphological features, and percentages of preoperatively embolized cases were statistically similar for the two treatment groups. The mean operative time for Group 1 was 497 minutes, compared with 290 minutes for Group 2 (P = 0.0005). The estimated blood loss for Group 1 was 657 ml, compared with 311 ml for Group 2 (P = 0.0008). Complication rates, residual AVM incidences, and clinical outcomes were similar for the two groups. CONCLUSION: Frameless stereotaxy allows surgeons to 1) plan the optimal trajectory to an AVM, 2) minimize the skin incision and craniotomy sizes, and 3) confirm the AVM margins and identify deep vascular components during resection. These benefits of stereotaxy were most apparent for small, deep AVMs that were not visible on the surface of the brain. Frameless stereotaxy reduces the operative time and blood loss during AVM resection.

Adolescent↗

PubMed2002

Neurological deterioration after coil embolization of a giant basilar apex aneurysm with resolution following parent artery clip ligation. Case report and review of the literature.

The authors present the case of a patient who suffered from progressive cranial nerve dysfunction, radiographically documented brainstem compression, and peduncular hallucinosis after undergoing endosaccular coil placement in a giant basilar apex aneurysm. Symptom resolution was achieved following clip ligation of the basilar artery. The pathogenesis of aneurysm mass effect due to coil placement is discussed and the pertinent literature is reviewed.

Basilar Artery↗