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Biomedical subjects

Howard A Riina

Publications and source records attributed to Howard A Riina.

12 recordsLinked to original sources

Vasospasm in aneurysmal subarachnoid hemorrhage: diagnosis, prevention, and management.

Cerebral vasospasm is a major cause of morbidity and mortality associated with subarachnoid hemorrhage (SAH). Advances in neuroimaging and development of newer intraparenchymal monitoring devices have improved the prediction and diagnosis of cerebral vasospasm significantly. Recent experimental and clinical trials have increased the armamentarium of preventive and treatment strategies for cerebral vasospasm. Vasospasm refractory to medical therapy usually is treated endovascularly with percutaneous transluminal balloon angioplasty (PTA) for proximal vessel vasospasm and vasodilator infusion for distal vessel vasospasm. Although vasospasm usually does not recur after PTA, recurrence is frequent after vasodilator infusion. The development of newer microballoon catheters has led to improvements in treatment of not only proximal but also distal vessel vasospasm with balloon angioplasty. This article reports on current knowledge in the diagnosis, prediction, prevention, and management of cerebral vasospasm.

Humans↗

Is routine intraoperative angiography in the surgical treatment of cerebral aneurysms justified? A consecutive series of 147 aneurysms.

OBJECTIVE: The role of intraoperative angiography (IA) in the surgical treatment of cerebral aneurysms has remained extremely controversial. We determine the frequency and predictors of unanticipated findings necessitating clip adjustment established on postoperative angiography (PA) in a consecutive series of 147 aneurysms. On the basis of published series, we discuss the utility, safety, accuracy, and cost effectiveness of adjunct IA in the surgical treatment of cerebral aneurysms. METHODS: We retrospectively examined the charts of 124 consecutive patients harboring 147 aneurysms that were surgically clipped between December 2000 and March 2005 and had PA available for review. Patient demographics, aneurysm size, location, Hunt and Hess score, Fisher grade, mode of aneurysm discovery, time between discovery and surgery, and PA results, as determined by a blinded independent neuroradiologist, were recorded. RESULTS: PA demonstrated two (1.4%) unexpected residuals, four anticipated residuals (2.7%), and four (2.7%) vessel compromises. Of the six unanticipated outcomes, two of two (100%) unexpected residuals and three of four (75%) vessel compromises were from large aneurysms (P = 0.0001 each). Middle cerebral artery aneurysms comprised 5 of 10 (50%) imperfect outcomes (three expected remnants and two vessel occlusions), which trended toward significance (P = 0.06). CONCLUSION: IA is recommended during the surgical clipping of complex or large aneurysms and some middle cerebral artery aneurysms. High cost-benefit ratio, false-negative rate, and moderate risk, however, preclude routine use. With future technological advances, IA may warrant broader use by replacing postoperative studies in the neurosurgical management of intracranial aneurysms.

Adolescent↗

Preoperative embolization in the treatment of choroid plexus papilloma in an infant. Case report.

The authors report a case of preoperative embolization and resection of a choroid plexus papilloma of the lateral ventricle in a 4-month-old boy. These vascular tumors of the central nervous system present a significant intraoperative bleeding risk. Attempts at preoperative embolization to reduce the bleeding risk have rarely succeeded because of the small and tortuous vessels feeding these tumors in infants. The case presented here supports the feasibility of preoperative embolization as a therapeutic adjunct in infants.

Blood Loss, Surgical↗

Advances in endovascular aneurysm treatment: are we making a difference?

Recent advancements in endovascular aneurysm repair, including bioactive and expansile coils and intracranial stents, hold promise for improved aneurysm occlusion rates. We report the immediate and midterm clinical and angiographic outcomes of a consecutive series of patients treated since the advent of these technologies. Clinical and radiological records of 134 patients with 142 aneurysms treated between 2001 and 2004 were retrospectively evaluated by an independent neurologist. Endovascular procedures were analyzed by an independent neuroradiologist blinded to all clinical information. Seventy-two ruptured and 60 un-ruptured saccular aneurysms, nine fusiform and one post-traumatic aneurysm were treated. Matrix coils were used in 53% of saccular aneurysms and HydroCoils in 13% of all aneurysms. Neuroform stents were deployed in 19% of aneurysms. Angiographic total or subtotal occlusion was achieved in 76% of cases and in 96% at last follow-up. Aneurysm recanalization was observed in 14% over a mean follow-up of 12 months, and 18% of aneurysms were retreated. Clinically relevant complications occurred in 6.0%, resulting in procedure-related morbidity of 0.6% and 0.6% mortality at 6 months. No aneurysm bled over a cumulative 1,347 months of observation. Newer embolization technologies can be exploited successfully even in more complex aneurysms with very low morbidity and mortality.

Adult↗

Endovascular procedures for treating wide-necked aneurysms.

Wide-necked aneurysms remain difficult to treat by either open microneurosurgical or endovascular procedures. Recent advances in the latter technology, including intracranial stents and bioactive coils, now allow an endovascular treatment option for cases in which this was not previously available. In this report the authors describe the new developments in endovascular technologies that make the treatment of wide-necked aneurysms possible. This includes discussion of intracranial stents and bioactive coils designed to promote obliteration of the aneurysm lumen. In addition, methods for coil insertion in wide-necked aneurysms are described, including balloon remodeling and various stent placement procedures. Wide-necked aneurysms previously thought to be untreatable by endovascular means can now be obliterated, thanks to new devices specifically designed for intracranial use.

Balloon Occlusion↗

Mechanical embolectomy.

Mechanical embolectomy in acute ischemic stroke employs the use of novel endovascular devices to revascularize occluded intracerebral arteries. Devices like the Merci Retiever and other endovascular snares, laser thrombectomy and rheolytic/obliterative microcatheters, intracranial balloon angioplasty and stenting, and intra-arterial and transcranial ultrasound-enhanced chemical thrombolysis are intended to improve tissue rescue and diminish reperfusion hemorrhage while broadening the population eligible for therapy. Patient selection with MRI- and CT-based stroke protocols can detect tissue at risk and may obviate the classic limitations of the stroke therapeutic time window. These devices are being developed and modified at a rapid pace, requiring mounting endovascular expertise, and are being used successfully alone or in conjunction with chemical thrombolysis with relative safety.

Brain Ischemia↗

Intracranial capillary hemangioma: case report and review of the literature.

BACKGROUND: Capillary hemangiomas are benign vascular lesions that commonly present at birth or in early infancy on the face, scalp, back, or chest. The authors present an exceedingly rare case of an intracranial capillary hemangioma arising in an adult. Only 4 biopsy-proven cases have been reported in the pediatric population previous to this case report. CASE DESCRIPTION: A 31-year-old pregnant woman presented at 38 weeks of gestation with severe headaches, nausea, and vomiting. Imaging revealed an extra-axial mass lesion arising from the tentorium with both supra- and infratentorial components. The patient underwent a resection of her tumor, which was diagnosed as a capillary hemangioma by histopathologic examination. The patient required 2 further resections after the lesion exhibited a rapid regrowth from residual tumor in the left transverse sinus. The patient has remained free of disease 41 months out from her third surgery. CONCLUSIONS: Intracranial capillary hemangiomas are exceedingly rare entities, with a capability for rapid growth. When gross total resection cannot be achieved, these patients should be observed closely, and the use of adjuvant radiotherapy should be considered.

Adult↗

Anterior communicating artery aneurysms.

ANTERIOR COMMUNICATING ARTERY aneurysms are complex lesions for which surgical success requires extensive preoperative and intraoperative planning. Adherence to the tenets of aneurysm surgery, including vascular control and preservation of perforating arteries, is essential for their exclusion from the circulation.

Brain↗

February 2002: 29-year-old woman with a skull mass for 2 months.

A 29-year-old woman had a 2-month history of an enlarging lesion over her left frontal bone following minor trauma. CT scan showed an osteolytic lesion with an overlying soft tissue mass, thought to be an unhealed skull fracture with pseudomeningocele. Left frontal craniotomy revealed a soft tissue mass, which was resected. Histologic examination revealed multinucleated giant cells mixed with Langerhan's cells that showed the characteristic "coffee bean nuclei." Eosinophils were scant. Immunostaining for CD1a and S100 revealed strong positive staining primarily in the Langerhans' cells while giant cells and inflammatory cells were negative. Immunostaining for CD68, in contrast, stained the osteoclast-like giant cells and macrophages. Electron microscopy confirmed the presence Birbeck granules. The final diagnosis was Langerhans' cell histiocytosis (histiocytosis X) of the skull.

Adult↗

Modified classification of spinal cord vascular lesions.

The literature on spinal vascular malformations contains a great deal of confusing terminology. Some of the nomenclature is inconsistent with the lesions described. Based on the experience of the senior author (R.F.S.) in the treatment of more than 130 spinal cord vascular lesions and based on a thorough review of the relevant literature, the authors propose a modified classification system for spinal cord vascular lesions. Lesions are divided into three primary or broad categories: neoplasms, aneurysms, and arteriovenous lesions. Neoplastic vascular lesions include hemangioblastomas and cavernous malformations, both of which occur sporadically and familially. The second category consists of spinal aneurysms, which are rare. The third category, spinal cord arteriovenous lesions, is divided into arteriovenous fistulas and arteriovenous malformations (AVMs). Arteriovenous fistulas are subdivided into those that are extradural and those that are intradural, with intradural lesions categorized as either dorsal or ventral. Arteriovenous malformations are subdivided into extradural-intradural and intradural malformations. Intradural lesions are further divided into intramedullary, intramedullary-extramedullary, and conus medullaris, a new category of AVM. This modified classification system for vascular lesions of the spinal cord, based on pathophysiology, neuroimaging features, intraoperative observations, and neuroanatomy, offers several advantages. First, it includes all surgical vascular lesions that affect the spinal cord. Second, it guides treatment by classifying lesions based on location and pathophysiology. Finally, it eliminates the confusion produced by the multitude of unrelated nomenclatural terms found in the literature.

Aneurysm↗

Endovascular management of dolichoectasia of the posterior cerebral artery report.

Congenital or nonatherosclerotic dolichoectasia is a rare condition; its etiology, natural history, and indications and technique of treatment are not yet clarified. During a workup for recent headaches and left-sided paresthesia in a 48 year-old female patient, brain MR imaging and cerebral angiography showed a large dolichoectasia of the P2 segment of the right posterior cerebral artery (PCA). The patient passed endovascular testing for occlusion of P2 with both balloon test occlusion and selective amytal testing. Endovascular coil occlusion of the right PCA dolichoectasia was successfully performed with hydrogel coils.

Amobarbital↗