Search PubMed⌕ Search

Biomedical subjects

F G Diaz

Publications and source records attributed to F G Diaz.

At least 73 records · Page 4Linked to original sources

Intracranial vertebral endarterectomy.

Intracranial vertebral endarterectomy was performed on six patients with vertebrobasilar insufficiency in whom medical therapy failed. The patients underwent operations for stenotic plaque in the intracranial vertebral artery with the opposite vertebral artery being occluded, hypoplastic, or severely stenosed. In four of the patients, the stenosis was mainly proximal to the posterior inferior cerebellar artery (PICA). In this group, after endarterectomy, the vertebral artery was patent in two patients, and their symptoms resolved; in one patient the endarterectomy occluded, but the patient's symptoms improved; and in one patient the endarterectomy was unsuccessful, and he continued to have symptoms. In one patient, the plaque was at the origin of the PICA. The operation appeared technically to be successful, but the patient developed a cerebellar infarction and died. In one patient the stenosis was distal to the PICA. During endarterectomy, the plaque was found to invade the posterior wall of the vertebral artery. The vertebral artery was ligated, and the patient developed a Wallenburg syndrome. The results of superficial temporal artery to superior cerebellar artery anastomosis are better than those for intracranial vertebral endarterectomy for patients with symptomatic intracranial vertebral artery stenosis. The use of intracranial vertebral endarterectomy should be limited to patients who have disabling symptoms despite medical therapy, a focal lesion proximal to the PICA, and a patent posterior circulation collateral or bypass.

Aged↗

Superficial temporal and occipital artery bypass pedicles to superior, anterior inferior, and posterior inferior cerebellar arteries for vertebrobasilar insufficiency.

Eighty-three patients underwent 85 intracranial to extracranial pedicle bypass anastomosis procedures to the posterior circulation. There were 15 patients with occipital artery (OA) to posterior inferior cerebellar artery (PICA) anastomosis, 20 patients with OA to anterior inferior cerebellar artery (AICA) anastomosis, and 50 patients with superficial temporal artery (STA) to superior cerebellar artery (SCA) anastomosis. All patients had transient ischemic attacks (TIA's) suggestive of vertebrobasilar ischemia. Twenty-seven patients had crescendo TIA's or stroke in evolution and were considered to be clinically unstable. All patients had severe bilateral distal vertebral artery or basilar artery disease. Twenty-two patients had bilateral vertebral artery occlusion and three had basilar artery occlusion. In this series, 69% had complete resolution of symptoms; the mortality rate was 8.4% and the morbidity rate 13.3%. Clinically stable patients did better than unstable patients. The STA-SCA anastomosis was well tolerated and technically less demanding than the OA-PICA or OA-AICA anastomosis procedures. Patients with symptomatic severe bilateral vertebral or basilar artery disease have a grave prognosis and the option of a surgical arterial pedicle revascularization procedure should be offered to them.

Adult↗

Posterior inferior to posterior inferior cerebellar artery anastomosis combined with trapping for vertebral artery aneurysm. Case report.

A case is presented in which a giant intracranial vertebral artery aneurysm gave rise to an associated ipsilateral posterior inferior cerebellar artery (PICA) from its waist. Proximal vertebral artery ligation at C-1 was achieved. The aneurysm filled from the opposite vertebrobasilar junction. Direct intracranial trapping of the right vertebral aneurysm was followed by successful anastomosis of the proximally sectioned right PICA to the adjacent left PICA in an end-to-end fashion.

Adult↗

Uterine rupture: are intrauterine pressure catheters useful in the diagnosis?

The usefulness of the intrauterine pressure catheter in the diagnosis of uterine rupture was assessed by review of 76 cases of uterine rupture, 39 of which were monitored with an intrauterine pressure catheter. The classic description of a loss of intrauterine pressure or cessation of labor was not observed in any of the patients. However, an increase in baseline intrauterine pressure was observed in four patients with an intrauterine pressure catheter. The increase in pressure was associated with severe variable decelerations such that by itself the intrauterine pressure catheter added little to the diagnosis of uterine rupture.

Adult↗

Management of cerebral aneurysms: further facts and additional myths.

In 1985 we reviewed 17 misconceptions or myths surrounding the treatment of aneurysmal subarachnoid hemorrhage that may contribute to the dismal outcome from these lesions. Since that time, significant new data, or facts, have become available regarding the influence of early aneurysm surgery on rebleeding, the efficacy of treatments for symptomatic arterial narrowing, improvements in surgical techniques such as temporary arterial clipping, and measures to protect the brain from ischemic injury. However, additional myths have become apparent which continue to limit our ability to improve the outcome of these patients. We review these facts and myths and discuss management of the patient with aneurysmal subarachnoid hemorrhage.

Antifibrinolytic Agents↗

Hemodynamic vertebrobasilar insufficiency as an adverse effect of antihypertensive therapy.

A 63-year-old white male with a 25-year history of hypertension experienced the onset of intermittent diplopia and gait disturbance 24 hours after a change in antihypertensive medication from atenolol 50 mg/d to enalapril 5 mg bid. Three weeks later, the patient was admitted with a worsening of symptoms. Cerebral arteriography revealed significant bilateral vertebral artery stenosis. Symptoms continued to progress in the hospital, and at the time of posterior circulation revascularization the patient had a persistent bilateral internuclear ophthalmoplegia and right ptosis. The need for a neurovascular workup and adjustment of therapy in patients with antihypertensive-associated cerebral ischemia is discussed.

Antihypertensive Agents↗

Surgical alternatives in the treatment of cavernous sinus aneurysms.

Direct surgery on aneurysms in the cavernous sinus is a formidable technical procedure. The intimate relationship of the intracavernous carotid artery to the venous structures and to the cranial nerves make surgical access difficult at best. Thirty-two of 356 aneurysm patients presented with symptomatic aneurysms originating from the intracavernous internal carotid artery. Twenty-one patients had aneurysms contained entirely within the cavernous sinus, and in 11 others the aneurysms arose within the cavernous sinus and extended into the subarachnoid space. Of the purely intracavernous aneurysms there were five small aneurysms (less than 25 mm) and 16 giant (greater than or equal to 25 mm) aneurysms. Fifteen patients with purely intracavernous lesions had a superior orbital fissure syndrome, and six had a variety of other symptoms. Of 11 patients with subarachnoid extension, five had a subarachnoid hemorrhage (Grade I or II), five had ipsilateral visual loss, and one had periorbital pain. The aneurysms were treated as follows: Group 1 received progressive ligation of the internal carotid artery in the neck with a Selverstone clamp and a surface superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis (purely intracavernous in nine, and with subarachnoid extension in one); Group 2 underwent trapping of the internal carotid artery and a deep STA-MCA anastomosis (purely intracavernous in seven); and Group 3 had direct clipping of the aneurysm (purely intracavernous in five, and with subarachnoid extension in 10). The cavernous sinus was entered directly through its roof by a pterional craniotomy with radical removal of the optic canal, lesser sphenoid wing, and lateral and superior orbital walls. Proximal control of the internal carotid artery was obtained through a cervical incision. Two patients in Group 1 developed transient neurological deficits, which resolved. Two patients in Group 2 developed a cerebral infarction, one of whom died; in both of these patients, the anastomosis was completed after the internal carotid artery occlusion. Two patients in Group 3 progressed from marked visual loss to blindness of the same side, and one developed an intraventricular hemorrhage during induction of anesthesia and died without surgery. It is proposed that a direct approach to symptomatic aneurysms in the cavernous sinus is the best initial alternative. When this approach is not feasible, a trapping procedure preceded by a high-flow extracranial-intracranial anastomosis may be considered. Although the authors have been able to clip aneurysms of various sizes, this has not been possible in all patients. Further work is needed in this area.

Cavernous Sinus↗

Surgical management of aneurysms in the cavernous sinus.

A series of 32 patients with aneurysms in the cavernous sinus region is presented. All of them have been operated upon through an intradural pterional approach and the aneurysms directly attacked. Only in 6 patients was the complete dissection of the internal carotid artery and of the aneurysm impossible because of the size of the aneurysms. In these cases the aneurysm has been traped by ligation of the internal carotid artery in the neck and its supraclinoid course and at the same time and extracranial intracranial anastomosis performed. One patient died from massive cerebral infarction after a trapping procedure and another died from a transoperative haemorrhage; another two developed a moderate hemiparesis which resolved within the first six postoperative weeks, and in two patients a preoperative severe visual impairment progressed postoperatively to complete visual loss. All others had a complete resolution of their preoperative symptoms and remained well. The advantages and disadvantages of the different approaches to intracavernous carotid artery aneurysms are discussed and the related literature reviewed.

Cavernous Sinus↗

Pitfalls during carotid endarterectomy.

It is estimated that between 1971 and 1987 the number of carotid endarterectomies has increased from 15,000 to over 85,000 per year. Unless the procedure can be performed safely with a combined morbidity and mortality which is below the yearly risk of stroke (5%) for patients with symptomatic carotid artery disease, one should reconsider this operation as a therapeutic option. We review our experience with 891 carotid endarterectomies performed between January 1979 and June 1987. There were 579 (65%) men and 312 (35%) women of ages from 34 to 82 (median 65); risk factors included diabetes mellitus 213 (14%), hypertension 603 (68%), and smoking 630 (70%). Clinical presentation consisted of transient ischemic attacks 506 (57%), cerebral infarction with minimal neurological residual 252 (28%), stroke in evolution 3 (0.3%) and, asymptomatic stenosis 130 (15%). All patients were operated on under endotracheal anesthesia with transoperative monitoring of intra-arterial pressure, central venous pressure and arterial blood gases. Thiopental (3-5 mg/kg) and lidocaine (1 mg/kg) were given for induction and at 15 minute intervals during carotid cross-clamping. Intraluminal shunts were used in 13 (2%). A conventional (open) endarterectomy was performed in 561 (63%) and a limited endarterectomy (closed) in 330 (37%). Complications included 11 (1%) deaths, 26 (3%) developed a major neurological deficit that persisted, 30 (3%) had perioperative TIA's which resolved completely. Of the patients with preoperative neurological deficits, 33 (4%) recovered. Therefore, at one month after surgery, 854 (96%) were either as well or better than preoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Cerebrovascular occlusive disease in children: a survey.

Eight cases of stroke in children treated with surgery are reported. Four of the patients had Moya-moya disease and presented with TIA. They were treated by surgically creating collaterals through the STA-MCA bypass, encephalomyosyangiosis and encephalomyoarteriosynangiosis operations. Three patients with traumatic or idiopathic carotid artery stenosis or occlusion presented with TIA and were treated with STA-MCA bypass. One patient with idiopathic carotid artery stenosis presented with a complaint of a continuous swishing noise in the ear and had a STA-MCA bypass followed by carotid artery ligation. Although stroke in children is usually secondary to systemic disease, there is a group of children with surgically treatable disease who need to be identified and treated. The potential benefit of surgery may depend on the promptness with which a definitive diagnosis is reached.

Adolescent↗

Freeze-fracture cytochemistry of cholesterol content in neuronal plasma membrane following cerebral ischaemia.

Minor changes on the neuronal perikaryon cytoplasm and large alterations in neuronal processes have been demonstrated with transmission electron microscopy after 60 minutes of focal and selective cerebral ischaemia. The distribution of cholesterol in neuronal plasma membrane and perikarya plasmalemma of normal and ischaemic caudate nucleus was investigated with the polyene antibiotic filipin, a morphological probe for membrane cholesterol domains in freeze-fracture replicas. After filipin incubation of prefixed vibratome slices, filipin-cholesterol complexes appeared as 20-30 proturberances and pits on P- and E-faces. Distinct patterns of filipin-cholesterol complexes were found in non-ischaemic and ischaemic neuronal membrane. The filipin-treated specimens showed a 35-40% drop in cholesterol content in the neuronal plasmalemma one hour after cerebral ischaemia.

Animals↗

Anomalies and variations of the middle cerebral artery: a microanatomical study.

The microvascular anatomy of the main trunk and divisions of the middle cerebral artery was studied in 104 unfixed brain hemispheres injected with polyester resin and dissected under the operating microscope. The following anomalies and variations of the middle cerebral artery were found: fenestration (1 case; 1%), located on the first 4 mm of the main trunk of the middle cerebral artery; duplication (1 case; 1%), with vessels arising from the internal carotid artery; accessory middle cerebral artery (2 cases; 2%), originating on the A1 segment of the anterior cerebral artery; single-trunk type of middle cerebral artery (4 cases; 4%), with no division of its main trunk; quadrifurcation (4 cases; 4%), in which the main trunk of the middle cerebral artery divided into four secondary trunks. The clinical implications of these anatomical findings are discussed, and photographs of representative specimens illustrate the anomalies.

Cerebral Arteries↗

Tandem bypass: occipital artery to posterior inferior cerebellar artery side-to-side anastomosis and occipital artery to anterior inferior cerebellar artery end-to-side anastomosis--a case report.

A unique example of posterior fossa revascularization is presented. A tandem bypass was performed by anastomosing the midoccipital artery to the posterior inferior cerebellar artery in a side-to-side fashion followed by anastomosis of the distal occipital artery to the anterior inferior cerebellar artery in an end-to-side fashion. The operation was designed to revascularize two separate vascular territories that were isolated in a patient thought to have an extremely compromised posterior circulation. The patient is doing well and is asymptomatic 3 years postoperatively.

Brain Stem↗

Microanatomy of the premamillary artery.

The premamillary artery was studied in 50 unfixed human brain hemispheres (51 vessels were found) which were injected with polyester resin and dissected under the operating microscope. In one hemisphere there was duplication of the premamillary artery. There were premamillary arteries arising from the posterior communicating artery (PCoA) in 49 cases and from the posterior cerebral artery in the remaining two. The arteries originated from the superior and lateral surfaces of the PCoA and coursed superiorly, laterally, and posteriorly to enter a triangular perforated space limited by the mamillary body and tuber cinereum medially, the optic tract anterolaterally, and the cerebral peduncle posterolaterally. This space is called the paramedian perforated substance. The premamillary artery had an outer diameter of 0.6 +/- 0.2 mm on the right side and 0.6 +/- 0.1 mm on the left. The length of the premamillary artery was 12.0 +/- 2.0 mm on the right side and 12.7 +/- 1.9 mm on the left. Sixty-three percent of the premamillary arteries gave off branches that supplied the cerebral peduncles, optic tract, and paramedian perforated space. The clinical importance of these anatomical data in the symptomatology and management of vascular and neoplastic diseases in and around the posterior circle of Willis is discussed.

Cerebral Arteries↗

Geriatric neurosurgery.

The "elderly," aged 65 and over, represent a rapidly growing proportion of the American population. Their percentage among the neurosurgical admissions at Henry Ford Hospital increased from 14.4% in 1978 to 22.4% in 1984. Occlusive cerebrovascular disease was the most frequent pathology seen, representing 40% of the population studied. Spinal degenerative myeloradiculopathy represented 14%, tumors 7%, trauma 5.4%, and intracranial hematomas represented 4% of the population. Vascular anomalies represented 3.3% of the patient group, with almost the same number of patients presenting with intracranial hemorrhage. The percentage of patients who were surgically treated was 58%. Mortality was 6.5%, with only 2.5% of the patients requiring special-care-facility placement following release from the hospital. An older group, aged 85 and over, represented 4% of our geriatric population. In the age 85+ group, occlusive cerebrovascular disease was the leading pathology (18% of the population), followed by subdural hematomas (15%), spinal degenerative myeloradiculopathy (11.6%), trigeminal neuralgias (7%), hydrocephalus (4%), vascular anomalies (4%), and tumors (4%). Patients in the age 85+ group were surgically treated in 41% of the cases, with a mortality of less than 10%. In the past, older age (greater than 65 years) was believed to be a contraindication to surgery, however, the increased life expectancy, number, and health of this population made reconsideration of this arbitrary age limit essential. We feel that age alone is not a barrier to proper neurosurgical treatment when other risk factors are adequately managed.

Age Factors↗