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Biomedical subjects

O H Reichman

Publications and source records attributed to O H Reichman.

At least 19 recordsLinked to original sources
PubMed1999

Optimal clip application and intraoperative angiography for intracranial aneurysms.

BACKGROUND: The actual incidence of residual aneurysm after clipping is unknown. The natural history of residual aneurysm can be regrowth and hemorrhage. Intraoperative angiography offers a cost-effective, safe interdiction to the problem of residual aneurysm and parent vessel stenosis. METHODS/RESULTS: Forty consecutive patients harboring 54 aneurysms underwent 42 operative procedures to clip 52 aneurysms, during which 220 intraoperative angiographic runs were performed. Ninety-three percent of the procedures were performed on patients with acute subarachnoid hemorrhage. There were 4 giant (>2.5 cm, 4/52 = 8%, all anterior circulation), 21 large (1.0-2.5 cm, 21/52 = 40%, 16/ 21 = 76% anterior circulation, 6/21 = 28% posterior circulation), and 27 small (<1.0 cm, 27/52-52%, 22/27 = 81% anterior circulation, 5/27 = 18% posterior circulation) aneurysms. Intraoperative angiography led to clip adjustment in 18/52 = 34% of aneurysms (4/18 = 22% for parent artery stenosis, 8/18 = 44% for residual aneurysm and 6/18 = 33% for both). Of the 18 adjustments made, 16 = 88% were made on giant or large aneurysms and two were small (one was a complex anterior communicating and one was a vertebral junction aneurysm). Follow-up angiography was performed on 26/42 = 62% of operative cases. Postoperative angiography confirmed intraoperative angiography in all cases. Two complications occurred during 220 angiographic runs: one embolic stroke and one incident of equipment failure. CONCLUSION: A grading scale was applied to test the relationship between anatomical site and size as they relate to the necessity for clip adjustment for complete aneurysm obliteration and/or parent artery compromise. Significance was related to site (basilar bifurcation, anterior communicating, middle cerebral bifurcation, and ophthalmic) and size (>1.0 cm), both as independent and codependent variables. An analysis of the cost-effectiveness of intraoperative angiography was demonstrated.

Adult↗
PubMed1997

Venous drainage of the inferolateral temporal lobe in relationship to transtemporal/transtentorial approaches to the cranial base.

OBJECTIVE: Intimate to the application of lateral transtemporal approaches to the cranial base are the identification, manipulation, and/or the sacrifice of the venous anatomy of the inferolateral temporal lobe and the superior petrosal sinus and the transection of the tentorium. This study demonstrates the relationship and variability of the venous drainage of the lateral and inferior surfaces of the temporal lobe. METHODS: Twenty-one specially prepared, injected cadaver specimens yielded 40 temporal lobes for examination. The venous systems in these specimens were traced from their origins on the temporal lobe (venous drainage complexes) to the transverse/petrosal sinuses, and the geometry of these venous complexes (venous configuration) was noted. The measurements of each complex's entry to the sinuses were noted. RESULTS: Four distinct venous drainage complexes were identified: 1) the lateral complex, 2) the anteroinferior complex, 3) the medial-inferior complex, and 4) the posteroinferior complex. Three basic venous configurations were found: 1) the candelabra of veins uniting to form one large draining vein, 2) multiple independent draining veins, and 3) venous lakes running in the tentorium before entering the sinuses. The lateral complex, incorporating the classic "vein of Labbé," was present in 100% of the specimens. However, in the majority of cases, it did not represent the dominant venous drainage of the lateral and inferior surfaces of the temporal lobe. CONCLUSION: An understanding of the complexity and diversity of the venous drainage complexes and their configurations is necessary to avoid venous complications during lateral cranial base surgery.

Cerebral Veins↗
PubMed1996

The need for neurological surgery programs to be departments.

The Decade of the Brain has brought recognition of the contributions neurological surgery has made to modern medicine, and neurological surgery training programs are a cornerstone of these achievements. While neurosurgeons are celebrating their achievements, however, a number of social, political, and administrative issues threaten to undermine the future of these programs. We discuss the ramifications of departmental status to the future of neurological surgery. These include the implications for operative experience-for example, carotid endarterectomy, spine instrumentation, acoustic tumors-the economic impact of a department versus a division, the ability to direct research, administrative input at the institutional level, and self-determination. We discuss the requirements for programmatic change and recommendations for national support.

Education, Medical↗
PubMed1995

Berry aneurysm.

Aneurysmal subarachnoid hemorrhage in a pregnant woman is a rare catastrophic situation that places both the mother and the fetus at high risk. When this situation arises, numerous relevant issues must be individualized in the effort to reduce hazards threatening both the mother and the fetus. These issues have been addressed in terms of the published experience and in terms of modern obstetric, anesthetic, and neurologic surgery technology.

Anesthesia, General↗
PubMed1995

Inhibition of in vitro meningioma proliferation after growth factor stimulation by calcium channel antagonists: Part II--Additional growth factors, growth factor receptor immunohistochemistry, and intracellular calcium measurements.

We have previously reported that calcium channel antagonists can block both the growth of meningiomas in culture and the potent growth stimulation of meningioma cells by epidermal growth factor (EGF) and platelet-derived growth factor (PDGF). This study further defines the nature of this growth inhibition. Primary meningioma cultures were established, and cells were characterized. Fibroblast growth factor or insulin-like growth factor-I growth stimulation in the presence of calcium channel antagonists was examined. In addition, the effects of ethylene glycol-bis-(aminoethylether) N,N,N',N"-tetraacetic acid and Bay K 8644, a calcium channel agonist, on the growth factors were analyzed. Growth factor receptor immunohistochemistry was performed on the original tumors and the in vitro meningioma cells. Twelve of 17 (71%) meningiomas in this study were positive for the EGF receptor, and 14 of 17 (82%) were positive for the PDGF receptor. Five of six (83%) of the culture cells were positive for the EGF receptor, and four of five (80%) were positive for the PDGF receptor. Intracellular calcium changes were quantified using the intracellular calcium-chelating, fluorescent dye, Fura-2. The growth stimulation of fibroblast growth factor and insulin-like growth factor-I on meningioma cells in culture was decreased in a dose-dependent manner by calcium channel antagonists. The growth stimulation of fibroblast growth factor and insulin-like growth factor-I was not affected by a reduction of extracellular calcium, whereas the growth stimulation of EGF and PDGF was. Interestingly, intracellular calcium was not increased after exposure to growth factors but was increased after serum stimulation. This increase could be blocked by preincubation with verapamil. Calcium channel antagonists can inhibit proliferation of meningioma cells in culture after stimulation with a number of growth factors. These drugs might disrupt intracellular calcium homeostasis or interfere with key elements of the growth factor signal transduction pathways. These mechanisms as well as the potential clinical relevance of these findings are discussed.

Adult↗
PubMed1994

Vascular considerations and complications in cranial base surgery.

The technical evolution of cranial base surgery has resulted in approaches that allow more radical surgical extirpation of complex cranial base lesions. Our service has extensively applied these cranial base approaches for lesions of the cranial base. A subgroup of 100 patients who had cranial base tumors involving potential manipulation or sacrifice of carotid arteries underwent 20-minute balloon test occlusions coordinated with vascular assessments consisting of a combination of the following: 1) four-vessel cerebral angiogram with compression studies; 2) occlusion transcranial Doppler ultrasonography; 3) occlusion single-photon emission computed tomography perfusion studies; and 4) xenon-133 cerebral blood flow studies. Transient neurological deficits associated with balloon test occlusion occurred in 7 of 100 patients (7%). Subsequently, 18 patients underwent permanent carotid occlusion by endovascular detachable balloons. Delayed ischemic complications (> 72 h) occurred in 4 of 18 (22%) patients. Additionally, a number of vascular complications not predicted by the balloon occlusion tests and vascular assessments were experienced. Repeat vascular assessments defined the causes and guided treatment of ischemic patients. Ischemic complications were caused by hemodynamic insufficiency, embolization, vasospasm, radiation vasculopathy, and venous anomaly. Our experience leads us to believe that no vascular assessment exists today that can predict the occurrence of vascular complications accurately. The current enthusiasm for cranial base surgery must be tempered with the sober reality that management of cerebrovascular anatomy and physiology remain significant limitations. Consideration of potential cerebrovascular complications is paramount to successful outcome and implementation of cranial base surgery.

Adult↗
PubMed1994

Venous infarction following translabyrinthine access to the cerebellopontine angle.

Between July 1988 and August 1992, 141 tumors of the cerebellopontine angle were surgically removed through a variety of transtemporal approaches. Superior petrosal sinus resection was performed in 44 of these patients with either large tumors in the vertical dimension or contracted mastoid anatomy, in an effort to enhance intradural tumor exposure and facial nerve identification. Three patients who underwent superior petrosal sinus resection developed early postoperative temporoparietal venous infarction with transient expressive aphasia. The ipsilateral cavernous sinus was entered and packed during tumor dissection in all three cases, and one patient also had sacrifice of the petrosal vein. This report reviews intradural cortical venous anatomy as it relates to transtemporal access to the cerebellopontine angle. Three cases of postoperative venous infarction are presented to emphasize the importance of the venous collateral circulation to the cavernous sinus in patients having undergone superior petrosal sinus resection.

Adult↗
PubMed1993

Skull base approaches to complex cerebral aneurysms.

The authors used skull base approaches to improve the surgical treatment of cerebral aneurysms. These approaches facilitate aneurysm surgery by allowing early proximal and distal vascular control, shortening and widening of the operative field, increasing the range of the surgeon's operative view and motion, and alleviating brain retraction. Twenty-two patients with ruptured giant or complex aneurysms were operated upon acutely using skull base approaches appropriate for their location: (1) the orbitocranial approach for anterior circulation, ophthalmic artery, and intracavernous lesions (n = 10); (2) the orbitozygomatic approach for aneurysms of the upper third of the basilar artery (n = 6); (3) the petrosal approach for aneurysms of the middle third of the basilar artery (n = 2); and (4) the far lateral-transcondylar approach for vertebrobasilar aneurysms (n = 4). Clipping and dissection of the aneurysms was facilitated by the skull base approaches. No surgical mortality occurred in this series of patients; transient cranial nerve paresis was the only morbidity related to the approaches. We compare the three-dimensional spatial geometry of skull base and conventional approaches, and discuss the advantages and nuances of skull base approaches.

Adult↗
PubMed1993

Use of vascularized fat from the rectus abdominis myocutaneous free flap territory to seal the dura of basicranial tumor resections.

Resection of large skull base tumors may sometimes result in extirpation defects that are not amenable to local tissue closure. Patients with these tumors require free tissue transfer for closure of the intracranial space after basicranial tumor extirpation. The deep inferior epigastric artery supplies the rectus abdominis muscle and the skin and subcutaneous tissue of the lower abdomen. The closure of massive, central defects can be performed with a free flap designed from the ample rectus abdominis vascular territory. This free tissue donor site has abundant and reliable well-vascularized skin and subcutaneous tissue that can be customized to seal these tenuous areas and provide three-dimensional reconstruction. We have modified the rectus abdominis myocutaneous free flap in seven patients for reconstruction of the skull base. The subcutaneous fat was sculptured to form a soft, vascularized "cork" and was used for obliteration of the irregular deep portions of defects at the midcranial base against the repaired or unrepaired dura. All patients who had the vascularized fat used to obliterate the deep space had successful closure of the defect without cerebral spinal fluid leak. There were two wound infections and one donor-site hernia in this group. The judicious use of the vascular territory of the deep inferior epigastric vessels can accomplish secure three-dimensional reconstruction of the skull base. The flap can be reliably transferred, and the vascularized subcutaneous fat can be used to sequester and seal the dura repair.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1993

Photodynamic therapy for intracranial neoplasms: investigations of photosensitizer uptake and distribution using indium-111 Photofrin-II single photon emission computed tomography scans in humans with intracranial neoplasms.

Photodynamic therapy is being investigated as an adjuvant treatment for intracranial neoplasms. The efficacy of this therapy is based on the uptake of photosensitizer by neoplastic tissue, its clearance from surrounding brain tissue, and the timing and placement of photoactivating sources. Photofrin-II is the photosensitizer most actively being investigated. We labeled Photofrin-II with Indium-111 and studied the uptake and distribution of this agent in 20 patients with intracranial neoplasms, using single photon emission computed tomography (SPECT) with volume rendering in three dimensions. Of these patients, 16 had malignant glial tumors, 2 had metastatic deposits, 1 had a chordoma, and 1 had a meningioma. Anatomical-spatial data correlated well between the SPECT images and contrast-enhanced computed tomography or magnetic resonance images. Regions of focal uptake on SPECT images correlated with the surgical histopathological findings of the neoplasm. The kinetics of photosensitizer uptake varied according to the tumor's histological findings, the patient's use of steroids, and among patients with similar types of tumor histology. Peak ratios of target-to-nontarget tissue varied from 24 to 72 hours after injection. The study data show that, to be most effective, photodynamic therapy may need to be tailored for each patient by correlating SPECT images with anatomical data produced by computed tomography or magnetic resonance images. Photoactivating sources then can be placed, using computer-assisted stereotactics, to activate a prescribed volume of photosensitized tumor at the optimal time for treatment.

Adult↗
PubMed1993

Photodynamic therapy for intracranial neoplasms: development of an image-based computer-assisted protocol for photodynamic therapy of intracranial neoplasms.

Photodynamic therapy is being studied as an adjuvant therapy for malignant gliomas. Therapeutic efficacy is based on photosensitizer uptake kinetics and the ability to deliver adequate light doses to an appropriate treatment volume at the optimal time. Our laboratory has developed an image-based, computer-assisted treatment-planning protocol to study the treatment variables leading to optimizing photodynamic therapy for intracranial neoplasms. Fifteen patients with recurrent malignant glial tumors underwent 16 treatments in the developmental phase of the project in which light treatment volume was progressively expanded. Group I (n = 4) received postresection intracavitary photoillumination only, Group II (n = 3) received limited interstitial/intracavitary photoillumination, and Group III (n = 9) received multiple interstitial/intracavitary photoillumination. Between 3 and 18 interstitial fiber probes were placed through optically lucent tumor access catheters. Computed three-dimensional image-based treatment planning provided reproducible data-based tumor volumes, treatment volumes, and stereotactic accuracy for tumor volume resection and interstitial light fiber insertion. Initial observations include: 1) treatment failures occur outside of the effective light treatment volumes; 2) effective light volumes can be expanded safely with multiple stereotactically implanted interstitial light fibers; and 3) optimal treatment involves individualized tailoring of light dose volume and geometry. This protocol allows standardized scientific study of the variables affecting the application of photodynamic therapy for intracranial neoplasms.

Adult↗
PubMed1993

Refinements using free-tissue transfer for complex cranial base reconstruction.

Resection of skull base tumors may sometimes result in massive extirpation defects that are not amenable to local tissue closure. Closure of large basicranial defects can be performed with either a myocutaneous, a deepithelialized myocutaneous, or a simple muscle free flap designed from the ample rectus abdominis vascular territory. This free-tissue donor site has abundant and reliable well-vascularized tissue that can easily be customized to seal these tenuous areas. The rectus abdominis muscle and its vascularized territory were used in 18 of 19 consecutive patients at our center to close basicranial ablation defects. Of these, 6 were rectus abdominis muscle flaps, 5 were myocutaneous rectus abdominis flaps, and 7 were deepithelialized rectus abdominis muscle flaps. All free flaps survived. The intracranial space was sealed successfully in all but one patient. This patient underwent reconstruction with a muscle free flap and had a postoperative cerebrospinal fluid leak. This complication could have been avoided by using a deepithelialized myocutaneous flap to obliterate the central dead space with the vascularized subcutaneous fat. Two patients experienced minor wound infections, and one had a subdural abscess that was fully contained by a free flap placed over the duraplasty. One patient had a donor-site hernia. There was no incidence of meningitis. Knowledge of the anatomy of the vascular territory of the deep inferior epigastric vessels can be used judiciously to secure three-dimensional reconstruction of the skull base. The donor site supplies ample tissue for reconstruction and allows individual tailoring for obliteration of geometrically complex extirpation defects in and around the cranial base without the need to reposition the patient.

Adolescent↗
PubMed1992

Neurotologic considerations in the treatment of advanced clival tumors.

Head and neck manifestations of advanced clival tumors result from subtle, yet progressive mass effect or direct involvement of multiple cranial nerves. Misinterpretation of clinical or radiographic findings in these patients may result in inappropriate treatment planning, increased patient morbidity, and probable tumor recurrence. Our combined experience in managing 21 patients with advanced clival tumors has shown that preoperative loss of vision, diplopia, or facial hypesthesia suggests superior parasellar disease. Facial twitching or neurotologic symptoms result from posterior central tumor growth, while inferior extension of disease leads to basal cranial nerve deficits with associated speech, voice, and swallowing dysfunctions. The purpose of this article is to correlate the complex anatomy of the clivus, brainstem, and cranial base and the various neurotologic findings associated with neoplasms in this region. Lateral skull base surgical procedures, based on preoperative clinicoradiographic assessment, will be detailed with particular emphasis on preservation of critical neurovascular structures.

Adolescent↗
PubMed1992

Improved cerebral blood flow and CO2 reactivity after microvascular anastomosis in patients at high risk for recurrent stroke.

The medical community has not yet identified cerebrovascular pathophysiological factors that distinguish patients at high risk for stroke or aid in selecting patients for microvascular cerebral bypass. In this study, we describe the courses of 13 patients, all of whom suffered recurrent episodes of transient cerebral ischemia after previous cerebral infarction. These patients underwent regional cerebral blood flow studies using xenon inhalation with a CO2 challenge before and at various times after extracerebral-to-intracerebral microvascular anastomosis. Collateral circulation was assessed in all patients before surgery using four-vessel cerebral angiography. Patients were followed for a mean of 30 months (range, 1-7 yr) after the anastomosis. Measurements of mean cortical cerebral blood flow, as measured using the initial Slope Index, and CO2 cerebrovascular reactivity of these 13 patients were compared with those in a group of 20 patients designed as controls. Hemispheric cortical blood flow was significantly depressed in these patients before surgery compared with those in the control group (P less than 0.05). After the bypass, the mean resting Initial Slope Index in these patients increased 14% (P = 0.0005). Cerebral blood flow both before and after CO2 inhalation improved significantly in these patients after surgery (P = 0.001). Detectors bordering computed tomographic or magnetic resonance image documented infarctions, identified as peri-infarct regions, and demonstrated significant mean increases in both cerebral blood flow (38.8-43.2 ml/min/100 g, P = 0.05) and CO2 cerebrovascular reactivity in these patients after bypass (1.71 + 1.91% to 4.00 + 2.38% change Initial Slope Index/mm Hg CO2, P = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Traumatic intracavernous aneurysm in children: massive epistaxis without ophthalmic signs.

Traumatic intracavernous aneurysms are a distinctly uncommon lesion in children. They usually present with compressive symptoms of the III, IV, V, or VI cranial nerves rather than epistaxis. Epistaxis is rare and usually minor and brief in duration. A child with severe head injury and basal skull fracture, who did not have any preceding symptoms or signs of ophthalmoplegia or exophthalmus, developed massive epistaxis as a leading symptom of the ruptured intracavernous aneurysm. Since there are no reported pediatric cases with fatal epistaxis as a presenting sign, we would like to share our experience.

Adolescent↗
PubMed1990

Sustained increased cerebral blood flow with prophylactic hypertensive hypervolemic hemodilution ("triple-H" therapy) after subarachnoid hemorrhage.

Delayed cerebral ischemia is the major cause of death and disability in patients who initially survive an aneurysmal subarachnoid hemorrhage (SAH). In the present study, a protocol for prophylactic hypertensive hypervolemic hemodilution ("triple-H" therapy) was utilized in the treatment of SAH, and the response of cerebral blood flow (CBF) was evaluated. Serial CBF measurements, f1 and CBF15, were performed using the xenon-133 inhalation technique to maximize therapy. Surgery within 24 hours of subarachnoid hemorrhage was preferred. In 43 patients with SAH, mean hemoglobin and hematocrit were lowered 3.0 +/- 0.3 g/dL and 8.9 +/- 0.5%, respectively, over the first 24 hours. Mean f1 and mean CBF15 over the same period increased 34.2 +/- 5.8% and 21.2 +/- 3.6%, respectively. The maximum mean increase in CBF was 47.2 +/- 4.7% for f1 and 30.1 +/- 3.2% for CBF15. Cerebral blood flow remained elevated during the 21 days after SAH, irrespective of neurological grade on admission, age, sex, or angiographic arterial narrowing. This is the first report of a consistent method for establishing sustained improvement in CBF after SAH. All patients managed in total compliance with the protocol remained neurologically stable or improved. Two patients developed delayed ischemia and infarction because of the inability to sustain protocol requirements. Thirty-six of the 43 patients (84%) were discharged capable of an independent lifestyle. Triple-H therapy is a safe and effective modality for elevating and sustaining CBF after SAH. In combination with early aneurysm surgery, it can minimize delayed cerebral ischemia and lead to an improved overall outcome.

Adult↗