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Biomedical subjects

H H Batjer

Publications and source records attributed to H H Batjer.

At least 55 records · Page 3Linked to original sources
PubMed1993

Cerebral protective effects of etomidate: experimental and clinical aspects.

Reduction of cerebral blood flow below a critical threshold for a protracted time interval results in irreversible metabolic events culminating in cell death. The development of agents capable of extending the tolerable ischemic interval is of great importance as such agents may allow time for therapeutic measures to be accomplished which could restore cerebral perfusion. This issue is of particular pertinence in the treatment of complex cerebrovascular diseases when local (or global) cerebral blood flow must be interrupted during vascular reconstruction. Thiopental achieved great popularity once protective properties were demonstrated experimentally. Unfortunately, serious cardiovascular depression associated with high-dose barbiturates as well as prolonged duration of action may decrease collateral flow and limit their utility. Etomidate is a nonbarbiturate carboxylated imidazole which is capable of similar cerebral metabolic suppression without significant cardiac side effects. Accumulating experimental evidence supports the protective properties of this drug and suggests that it may be valuable clinically for this purpose. Significant adrenal suppression is a major toxic effect that must be treated if large doses or protracted administration is planned.

Animals↗
PubMed1992

The transcranial Doppler appearance of acute carotid artery occlusion.

Transcranial Doppler ultrasound is a noninvasive technique of cerebral blood velocity measurement that is being increasingly used to detect untoward hemodynamic changes. In this report, we describe striking transcranial Doppler ultrasound changes occurring in 2 patients after cervical carotid artery occlusion that led to cerebral infarction. These changes consist of the sudden appearance of a Doppler signal of extremely low pulsatility and moderately high velocity in the middle cerebral artery distribution. In 1 patient, this signal was the first sign of carotid occlusion. We suggest that these transcranial Doppler ultrasound changes can provide an early warning of carotid artery compromise.

Acute Disease↗
PubMed1992

The use of acetazolamide-enhanced regional cerebral blood flow measurement to predict risk to arteriovenous malformation patients.

Regional hemodynamic disturbances may complicate the treatment of certain cerebral arteriovenous malformations (AVM) and occasionally produce life-threatening situations. Acetazolamide-enhanced quantitative regional cerebral blood flow studies were performed preoperatively in 35 patients to determine if patterns of vasoreactivity could be identified that might be markers for postoperative morbidity. Ipsilateral and contralateral regions of hypoperfusion were identified on resting studies, and a steal index was calculated by dividing the regional cerebral blood flow in the steal region by the flow in a normal cerebellar region. Flow in these regions of interest was again quantitated after the administration of acetazolamide, a known cerebral vasodilator. A delta value was calculated by subtracting the resting index values from the acetazolamide indices. Abnormally enhanced vasoreactivity (vasodilation) to acetazolamide stimulation was noted in these threatened territories in AVM that had perforating vessel feeding and angiographic steal phenomena, that developed hyperemic disturbances, and that resulted in poor outcomes. These findings call into question traditional theories of AVM-related hemodynamic decompensation and suggest unique smooth muscle derangements in cerebral vasculature in some AVM patients.

Acetazolamide↗
PubMed1992

Arteriovenous malformations of the brain: choosing embolic materials to enhance safety and ease of excision.

The authors report their experience with surgical resection of 108 previously embolized arteriovenous malformations (AVM's). Embolization was performed via only transfemoral catheterization in 70 lesions and via the surgical exposure of feeding vessels in 32. The remaining six patients were referred for resection following silicone sphere embolization elsewhere. Materials used included polyvinyl alcohol (PVA) foam, platinum microcoils, detachable silicone balloons, surgical silk, a mixture of 33% ethanol and microfibrillar collagen, and isobutyl cyanoacrylate (IBCA). It is believed that proximal arterial occlusion with balloons is an inferior choice for preresection embolization, because the technical difficulty of placement is high and the nidus of the AVM is unaffected. Vascular coagulation and section and AVM retraction are more difficult with IBCA; therefore, this is also considered an inferior choice. Among the materials studied, the combination of PVA for distal occlusion and microcoils for proximal occlusion appears to be the superior choice. Fewer complications (stroke or hemorrhage) are seen when intraarterial Amytal (amobarbital) testing is used to guide the embolization. Data regarding toxicity, oncogenicity, and vascular metabolism or recanalization associated with PVA, IBCA, and n-butyl cyanoacrylate are reviewed.

Bucrylate↗
PubMed1992

Management controversy. Medical versus surgical therapy for spontaneous intracerebral hemorrhage.

The controversy surrounding the management of intracranial hemorrhage seems to have been quieted by a large group of recent studies. Future efforts must focus on expansion of the current population screening projects for early detection of hypertension. Whereas some potential exists for new innovative surgical techniques to offer some benefit, it should be kept in mind that most of these patients suffer from end-stage cardiovascular, cerebrovascular, and peripheral vascular disease.

Cerebral Hemorrhage↗
PubMed1991

Sickle cell disease and aneurysmal subarachnoid hemorrhage.

While neurological complications are common in sickle cell disease, aneurysmal subarachnoid hemorrhage has been rarely reported. A case is presented of a young man with sickle cell disease and subarachnoid hemorrhage found to have two mid-basilar aneurysms, the largest of which had bled. Available literature suggests that this patient may be quite representative as nearly one half of documented cases have been noted to harbor multiple aneurysms, and posterior circulation involvement appears to be common. These anatomic features may relate to the pathophysiology of arterial destruction common in sickle cell disease.

Adult↗
PubMed1991

Emergent aneurysm surgery without cerebral angiography for the comatose patient.

Neurologically based clinical grading scales offer excellent prognostic information for the patient suffering diffuse subarachnoid hemorrhage (SAH). These grading scales are less applicable to patients with life-threatening intraparenchymal hematomas after aneurysmal rupture. During the last 3 years, four patients in a comatose state with brain stem compression syndromes documented by computed tomographic scans have undergone emergent operation in our neurosurgical service. Each patient was so critically ill that we believed it unwise to delay craniotomy for diagnostic angiography. The average delay from the onset of coma to skin incision was 3.02 hours (range, 1.67-6.5 hours), and the average delay from arrival in our unit until skin incision was 1.8 hours (range, 0.75-2.5 hours). The condition of two arousable patients deteriorated while they were in the emergency room, presumably from new bleeding. Each patient underwent craniotomy for hematoma evacuation, definitive aneurysm clipping, and lobectomy for decompression. Temporary clipping was employed in one patient, and intraoperative rupture occurred in two others. Three patients survived but retain significant disability. Emergent craniotomy with empiric exploration of appropriate subarachnoid cisterns after hematoma decompression may be life-saving in some cases. The delay imposed for diagnostic angiography may be avoided in attempts to save vital minutes of severe brain stem compression.

Adult↗
PubMed1991

Intraarterial sodium amytal administration to guide preoperative embolization of cerebral arteriovenous malformations.

In preoperative embolization of cerebral arteriovenous malformation (AVM), one difficulty frequently encountered is assessment of the risk of ischemic deficit, posed by proceeding with embolization. One technique to assist prediction of tolerance of devascularization involves superselective injection of sodium amytal into cerebral arteries, prior to and during embolization. Since September, 1985, we have performed 119 embolization procedures in 77 patients with cerebral AVM. Of these, 89 procedures in 60 patients involved superselective intracerebral catheterization and embolization with either polyvinyl alcohol (PVA) alone or in combination with platinum microcoils, surgical silk, or a mixture of ethanol and microfibrillar collagen. In 50 of these procedures, we superselectively administered sodium amytal intraarterially immediately prior to embolization, for purposes of functional testing. Groups of patients undergoing testing were compared to groups not tested prior to embolization, for development of transient or permanent neurologic deficits or cerebral hemorrhage, subsequent to embolization. Significantly better results, both in absolute numbers and severity of complications, were found when testing was employed. No complications of amytal administration were seen. In four cases, embolization was altered or discontinued based on development of a deficit at the time of amytal administration. We conclude that the brief anesthetic effect of intraarterial testing with sodium amytal is a safe and important adjunct during preoperative embolization of cerebral AVMs.

Journal Article↗
PubMed1991

Management of hemorrhagic complications from preoperative embolization of arteriovenous malformations.

Endovascular embolization procedures have undergone dramatic evolution and improvement in recent years. Despite these advances, controversy remains regarding the optimal role of these procedures in treating cerebral arteriovenous malformations (AVM's) and whether their purpose should be as a presurgical adjunct or as primary therapy. This controversy risks fragmentation between disciplines in the broader efforts to improve management of cerebrovascular disorders. The authors report seven cases of life-threatening hemorrhages that occurred during staged invasive therapy for AVM's which illustrate the value of a unified team approach to optimize patient care. Each patient underwent at least one embolization procedure using polyvinyl alcohol particles, followed in two cases by the occlusion of proximal feeding vessels by platinum microcoils and in one case by the attempted detachment of an endovascular balloon. In three patients, catheter penetration into the subarachnoid space resulted in subarachnoid hemorrhage. One patient suffered rupture of a large feeding vessel during balloon inflation. The final three patients sustained intracranial hemorrhage 2 hours, 8 hours, and 5 days, respectively, following embolization. All but two patients underwent emergency craniotomy at the time of the complication. These cases underscore the advantages of interdisciplinary management optimizing decision-making and providing expeditious care when life-threatening complications develop.

Adult↗
PubMed1991

The effects of etomidate on cerebral metabolism and blood flow in a canine model for hypoperfusion.

The effects of etomidate, a nonbarbiturate cerebral metabolic depressant, on cerebral metabolism and blood flow were studied in 29 dogs during cerebral hypoperfusion. Three groups of animals were studied during a 45-minute normotensive and a 30-minute hypotensive period: 10 control animals without etomidate, 11 animals receiving a 0.1-mg/kg etomidate bolus followed by an infusion of 0.05 mg/kg/min etomidate (low-dose group), and eight animals receiving doses of etomidate sufficient to suppress electroencephalographic bursts (high-dose group). The mean arterial pressure fell to similar levels (p less than 0.05) during hypotension in all three groups (40 +/- 5, 38 +/- 3, and 27 +/- 6 mm Hg, respectively). The mean cerebral oxygen extraction fraction rose (p less than 0.05) from 0.23 +/- 0.02 to 0.55 +/- 0.08 in the five control animals tested and from 0.33 +/- 0.02 to 0.53 +/- 0.02 in the seven animals tested in the low-dose group, but did not increase (p greater than 0.05) in the four animals tested in the high-dose group (0.24 +/- 0.03 to 0.23 +/- 0.05). Mean cerebral blood flow levels decreased in all groups during hypotension (p less than 0.05): 42 +/- 3 to 21 +/- 4 ml/100 gm/min (52% +/- 12% decrease) in the five animals tested in the control group, 60 +/- 8 to 24 +/- 6 ml/100 gm/min (56% +/- 13% decrease) in the four animals tested in the low-dose group, and 55 +/- 8 to 22 +/- 3 ml/100 gm/min (60% +/- 4% decrease) in the four animals tested in the high-dose group. In summary, the cerebral oxygen extraction fraction increased in the control animals and low-dose recipients during hypotension, suggesting the presence of threatened cerebral tissue. In contrast, the cerebral oxygen extraction did not change during hypotension when high-dose etomidate was administered. It is concluded that high-dose etomidate may preserve the cerebral metabolic state during hypotension in the present model.

Animals↗
PubMed1990

Failure of surgery to improve outcome in hypertensive putaminal hemorrhage. A prospective randomized trial.

Hypertensive putaminal hemorrhage remains a major cause of hemorrhagic stroke carrying extremely high morbidity. Considerable controversy remains regarding the optimal form of therapy. Between 1983 and 1989 we conducted a prospective randomized trial with three treatment strategies: best medical management, best medical management plus intracranial pressure monitoring, and surgical evacuation. Only patients with significant deficit harboring a putaminal hematoma at least 3.0 cm in diameter were entered. The study was interrupted after 21 patients had been studied (9, best medical management; 4, intracranial pressure monitoring; and 8, surgical evacuation). No differences were found among groups for age, admission blood pressure, and time interval between onset of symptoms and arrival at hospital. None of the subjects were capable of returning to prestroke activity. Fifteen (71%) died or remained vegetative at 6 months, and only 4 (19%) were capable of independent life at home. Of the 9 patients in the best medical management arm, 7 were dead or vegetative. In the surgical group, 4 patients died and only 2 were capable of independent life. These results suggest that current medical and neurosurgical therapies remain ineffective in preventing the devastating neurologic consequences of hypertensive putaminal hemorrhage.

Adult↗
PubMed1990

Focal subarachnoid hematoma: an unusual cause of delayed third cranial nerve paralysis.

We report a case of delayed onset of ultimately permanent oculomotor nerve palsy following a focal aneurysmal hemorrhage into the adjacent interpeduncular cistern. Operative inspection revealed no direct nerve compression by the aneurysmal fundus. Third cranial neuropathies following subarachnoid hemorrhage can occur independently of direct aneurysmal mechanical compression.

Aged↗
PubMed1990

Transcranial Doppler ultrasound as a guide to graded therapeutic occlusion of the carotid artery.

Although gradual carotid artery occlusion is an accepted and effective treatment for some surgically inaccessible intracranial aneurysms, there are no specific guidelines to determine the optimal amount of carotid artery narrowing at each adjustment. The technique of transcranial Doppler ultrasound, however, allows continuous measurement of blood velocity in the middle cerebral artery as the carotid artery is narrowed, so that hemodynamic effects and development of collateral flow can be immediately assessed at the bedside at each adjustment of the carotid artery diameter. This case report describes the use of transcranial Doppler to guide the rate of carotid occlusion in a patient with an unclippable giant aneurysm of the carotid artery. Sudden carotid occlusion and gradual occlusion at the usual rate were not tolerated by the patient, but repeatedly tightening the clamp until the first signs of attenuation of the Doppler signal allowed an expedient occlusion without complication. Transcranial Doppler ultrasound can provide a useful dynamic guide to gradual therapeutic carotid occlusion.

Carotid Arteries↗
PubMed1990

Resolution of a recurrent/residual bacterial aneurysm during antibiotic therapy.

Management of patients harboring infectious intracranial aneurysms remains controversial because of the technical problems associated with the obliteration of these lesions as well as their frequent regression during antibiotic therapy. A case of a ruptured bacterial aneurysm of the distal middle cerebral artery in which a segment of the artery was found to be inflamed and necrotic is presented. The ruptured portion of the sac was clipped, leaving a small tag of aneurysmal tissue. Five days later, this tag was found to have expanded into a second aneurysm. This second lesion resolved with antibiotic therapy. Because of the responsiveness of infected cerebral arteries to the appropriate antibiotics, a less than radical surgical tactic may be a successful alternative to excision of the diseased arterial segment followed by distal revascularization in treating these lesions.

Aneurysm, Infected↗
PubMed1990

Enlarging thrombosed aneurysm of the distal basilar artery.

The case of a 65-year-old man who had partial left third nerve palsy is reported. Radiographic examination disclosed a completely thrombosed giant suprasellar aneurysm. Although an angiogram appeared to indicate that his aneurysm arose from the distal basilar artery, he was also noted to have an unusual and ectatic distal internal carotid artery on the left side, and this was also felt to be a potential source of the aneurysm. Operative exploration was performed and confirmed the basilar artery as the sight of origin, and definitive therapy was deferred. The patient's progress was monitored, and for 3 years his neurological course was stable and there was no change in his radiographic abnormalities. During the 6 months following this period, the patient developed signs and symptoms of progressing hydrocephalus and was found to have significant enlargement of his still completely thrombosed giant aneurysm. This complicated case highlights the controversy regarding the management of this difficult condition, particularly with regard to endovascular therapies, and also provides insight into the evolution of this dynamic disease process.

Aged↗
PubMed1990

Transcranial Doppler pulsatility in vasodilation and stenosis.

Although blood velocity in the major intracranial vessels is readily measured with transcranial Doppler ultrasound (TCD), the interpretation of velocity changes is by no means straightforward. For example, a velocity increase can arise from either a local stenosis or a decrease in downstream resistance, and these mechanisms have contradictory implications for blood flow. To determine whether TCD pulsatility might distinguish these two mechanisms, Doppler ultrasonic readings were taken from an artificial vascular model under conditions of either stenosis or distal dilation. In addition, TCD studies of nine patients with unihemispheric arteriovenous malformations (AVM's) and 16 TCD studies of seven patients with unihemispheric aneurysmal vasospasm were reviewed, and pulsatilities of the AVM's (representing decreased resistance) were compared with those of the vasospastic vessels (representing stenosis). The average percentage drop in pulsatility in the vasodilated configuration of the model/percentage increase in velocity was 0.38 +/- 0.08 (+/- standard error of the mean), while that for stenosis was 0.20 +/- 0.01. Similar comparisons of the patient population yielded 0.67 +/- 0.16 for the AVM group and 0.26 +/- 0.04 for the vasospasm group. These differences were significant (p less than 0.05). The fall in pulsatility associated with a given increase in velocity is significantly greater when the velocity increase arises from diminished downstream resistance than from stenosis.

Cerebrovascular Circulation↗
PubMed1990

Retrograde suction decompression of giant paraclinoidal aneurysms. Technical note.

Giant paraclinoidal carotid artery aneurysms frequently require temporary interruption of local circulation to facilitate safe occlusion. Due to brisk retrograde flow through the ophthalmic artery and cavernous branches, simple trapping of the aneurysm by cervical internal carotid artery clamping and intracranial distal clipping may not adequately soften the lesion. The authors describe a retrograde suction method of aspiration of this collateral supply which they have used in over 40 cases. After temporary trapping, a No. 18 angiocatheter is inserted into the cervical internal carotid artery. This catheter is then connected to a wall suction point allowing rapid aneurysm deflation. This technique, accomplished by the surgical assistant, permits the surgeon the freedom to use both hands in dealing quickly with the aneurysm.

Carotid Artery Diseases↗