Frederick A. Simeone

The results of operations on the lumbar spine in patients who have diabetes mellitus.

The results for sixty-two patients who had had a diagnosis of diabetes mellitus and lumbar disc disease or spinal stenosis and had been managed with a posterior decompressive procedure were compared, in a retrospective study, with those for sixty-two age and sex-matched non-diabetic (control) patients who had had similar operative procedures. Forty-four of the sixty-two diabetic patients and fifty-five of the non-diabetic patients were available for long-term follow-up (mean, five and seven years, respectively). Among the diabetic patients, there were high rates of postoperative infection and prolonged hospitalization compared with the rates for the control group. The long-term result was excellent or good for seventeen (39 per cent) of the forty-four patients who had diabetes mellitus and for fifty-two (95 per cent) of the fifty-five non-diabetic patients. The poor results in the diabetic patients may have been related to coexisting diabetic neuropathy, to the associated microvascular disease that affects the spinal nerve roots in diabetic patients, or to the failure of the nerve roots of these patients to recover after decompressive procedures.

Arterial Obstruction and Ocular Neovascularization

A series of 12 patients (13 eyes) with neovascular glaucoma in association with arterial obstructive disease is presented. Appropriately characterized as having an ocular ischemic syndrome, the anterior segment findings in each included aqueous flare and rubeosis iridis. Posterior segment manifestations included midperipheral intraretinal hemorrhages (venous stasis retinopathy), narrowed retinal arteries, often a cherry red spot, and neovascularization of the disc and/or retina. Most eyes with the ocular ischemic syndrome have either ipsilateral common carotid artery obstruction or severe bilateral obstruction of the internal carotid arteries.

Comparison of smoking habits between patients with surgically confirmed herniated lumbar and cervical disc disease and controls.

There have been numerous studies that implicate cigarette smoking as a risk factor for the development of back pain or disc disease. The purpose of this article is to review patients who underwent surgery for cervical or lumbar radiculopathy and to investigate the relationship between cigarette smoking and development of surgical disc disease. A cigarette smoking study of 205 surgical patients with lumbar and cervical disc diseases was done, with the surgical patients compared to 205 age-sex-matched inpatient controls during 1987-1988. This study was conducted at the Pennsylvania Hospital in Philadelphia, Pennsylvania. There were 163 patients with lumbar disc disease and 42 patients with cervical disc disease. The ratio of men to women was 1.5:1 for lumbar disc and 2.5:1 for cervical disc disease. Smoking history (current and ex-smokers) was strikingly increased in both prolapsed lumbar intervertebral disc (56% vs. 37% of controls, p = 0.00029) and cervical disc disease (64.3% vs. 37% of controls, p = 0.0025). Calculated relative risks for smokers were 2.2 for lumbar disc and 2.9 for cervical disc diseases. This association between cigarette smoking and disc disease was more significant when comparing between current smokers versus nonsmokers (p = 0.000011 for lumbar disc disease, and p = 0.00064 for cervical disc disease). Relative risks for current smokers were 3.0 for lumbar disc and 3.9 for cervical disc diseases. This correlation was significant for both males (p = 0.000068 for lumbar disc disease, p = 0.043 for cervical disc disease) and females (p = 0.018 for lumbar disc disease, p = 0.006 for cervical disc disease).(ABSTRACT TRUNCATED AT 250 WORDS)

Cervical radiculopathy: a review

This paper is a review of current information on cervical radiculopathy. The focus is on the natural history of the process, the accuracy of diagnostic tests to determine etiology, the differential diagnosis involved, and the surgical tactics available. The most important conclusions are the criteria for patient selection for surgery and a statistical demonstration of the adequacy of both the anterior and the posterior approaches for decompression of the cervical nerve root.

Ischemic brain edema: comparative effects of barbiturates and hypothermia.

The effect of pentobarbital and hypothermia on the development of ischemic brain edema was studied in 23 rhesus monkeys undergoing transorbital middle cerebral artery occlusion. Fifteen additional animals served as undipped controls. Regional cortical cerebral blood flow (rCBF), arteriovenous oxygen content difference (AVDOa), and regional cortical metabolic rate of O2 (rCMROa) were measured hourly until sacrifice 11 hours postocclusion, at which time ischemic cerebral edema was measured. In 8 animals no treatment followed the occlusion, and these developed significant edema. In 7 animals pentobarbital 14 mg/kg was administered intravenously 30 min after occlusion and 7 mg/kg every 2 hours thereafter. In this group ischemic brain edema was negligible. In 8 animals, hypothermia to 25.9 ± 0.5°C was started 30 min after occlusion and maintained until sacrifice; ischemic brain edema was not significantly altered from untreated-clipped animals. On the basis that both pentobarbital and hypothermia produced similar changes in rCBF, AVDOj, and rCMRO2, but only pentobarbital prevented edema, it is postulated that the mode of action of barbiturates in preventing ischemic brain edema is not entirely related to their known effect on blood flow and metabolism.

Thoracic disc herniation. Re-evaluation of the posterior approach using a modified costotransversectomy

A consecutive series of 23 thoracic disc herniations in 21 patients treated between 1980 and 1988 were reviewed. All patients were decompressed through a posterolateral approach (costotransversectomy or transpedicular). Pain and weakness were the most common presenting symptoms. Twenty-one thoracic disc herniations in 19 patients were available for long-term follow-up, averaging 58.1 months. Sixteen patients had an excellent or good result. Three patients had a fair result. There were no poor results. All six patients with significant preoperative lower extremity weakness improved. Pain was relieved in 16 patients and reduced in three. There were no significant neurologic complications associated with the procedure. Posterolateral decompression for thoracic disc herniation remains a viable alternative without the inherent risk and morbidity of the transthoracic approach.

Experimental hypervolemic hemodilution: physiological correlations of cortical blood flow, cardiac output, and intracranial pressure with fresh blood viscosity and plasma volume.

Rheological, cerebrovascular, and cardiovascular alterations induced by serial plasma volume (PV) expansion were evaluated in splenectomized dogs. Seven dogs received two infusions of autologous plasma within 120 minutes; each infusion equaled 20% of the respective dogs total blood volume (TBV). The PV increased 31% and then another 26% after the two respective infusions, and the hematocrit (Hct) was obligatorily decreased by 22% during the experiment. The fresh blood viscosity at the shear rate of 10 sec-1 varied inversely with the TBV and the PV and correlated directly with the Hct after these plasma infusions. Cardiac output (CO) increased 71% after the two infusions without significant alterations in mean arterial blood pressure. Additionally, CO was inversely related to both Hct and blood viscosity. Although the 15% rise in regional cortical blood flow (rCoBF) in the territory of the middle cerebral artery did not reach statistical significance, the rCoBF was related inversely to both Hct and blood viscosity and directly to TBV, PV, and CO after the plasma infusions. Cortical vascular resistance (CVR) decreased 18% after the two infusions. The CVR correlated inversely with PV and directly with Hct and blood viscosity. Our data suggest that hypervolemic hemodilution with expansion of PV increases CO more than cerebral blood flow in normal brain. Fresh blood viscosity seems to be a major factor determining CO and cerebral perfusion after IV expansion. This study adds support to the hypothesis that reductions of blood viscosity account for the direct relationship between cerebral blood flow and CO observed after intravascular volume expansion with hemodiluting agents. Hypervolemic hemodilution with plasma reduces CVR, possibly secondary to its effect on blood viscosity, and also raises intracranial pressure.

upper Lumbar Disc Herniations

This study reviews the presentation, diagnosis, and outcomes of upper lumbar disc herniations (L1-2, L2-3, L3-4). One hundred forty-one patients operated upon at three centers between 1980 and 1990 were analyzed (102 men, 39 women; 3 L1-2, 21 L2-3, 117 L3-4; average age 51.6 years; 10.4% of all lumbar discectomies performed). Preoperative signs and symptoms were highly variable. Sensory, motor, and reflex testing was variable and potentially misleading in suggesting a level of herniation. In analyzing radiographic studies (noncontrast CT, myelography, MRI) individually and using other radiographic studies and operative findings as a standard for comparison, a high false-negative rate was found for all studies when considered individually, especially at the higher L2-3 level. Intraoperative radiographs were employed with increasing frequency as the level of herniation ascended. Six operative complications (4.3%) were identified, all of which were treated and were resolving at the time of discharge. Follow-up obtained at an average of 2.2 years in 87% of patients by chart review showed no reoperations or late complications. Noncompensation patients had a significantly higher percentage of good/excellent results (86%) than those with compensation or legal claims pending (45% good/excellent results). Based upon these data, we recommend myelogram with postmyelogram CT and/or MRI in the workup of these patients and intraoperative radiographs in all cases when decompressing an upper lumbar disc herniation. Patients with compensation/legal claims should be approached cautiously, because their subjective results are significantly worse than those of noncompensation patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Attenuation of ischemic brain edema by pentobarbital after carotid ligation in the gerbil.

The efficacy of pentobarbital in the treatment of ischemic cerebral edema was evaluated in 160 gerbils. Animals underwent carotid ligation under ether or pentobarbital (50 mg/kg) anesthesia. The pentobarbital anesthetized group received an additional dose of 30 mg/kg 4 h after ligation. Animals were evaluated for neurologic deficit at 4 and 8 h post-ligation, then sacrificed. Water content of each hemisphere and swelling percentage were calculated from the wet and dry weights of the hemispheres. Swelling percentage in animals anesthetized with ether was 6.374 ± 0.89 SE, whereas gerbils who underwent sham carotid ligation showed a negligible (0.491 ± 0.15) swelling percentage (p < 0.01). Pentobarbital animals had a swelling percentage of 3.359 ± 0.68. This represents a significant edema reduction compared to ether-anesthetized animals (p < 0.01). Neurologic deficit was decreased by 56.7< (17/60 vs 30/60) in pentobarbital animals compared with ether animals (p ± 0.025). Mortality at 8 hours was reduced by 75< (2/60 vs 8/60) in pentobarbital animals (p < 0.05).

Herniated Lumbar Disc in Patients Over the Age of Fifty

Fifty patients ranging in age between 50-78 years (mean, 56) underwent surgery for a herniated lumbar disc between January 1986 and July 1988. All had objective clinical and radiographic evidence of a herniated disc. All had had failure during an appropriate period of conservative treatment. Far lateral herniation occurred in 8%, and 28% had disc herniations at L2 or L3. Surgical results were 64% excellent, 28% good, 6% fair, and 2% poor. Complications including urinary tract infection, wound infection, myocardial infarction, and pulmonary embolism were observed in 8% of patients. Lumbar disc herniation in the elderly is common. After thorough evaluation to exclude neoplasm or infection, decompression of neural structures can lead to 90% good to excellent results. Spinal stenosis must be carefully considered both preoperatively and intraoperatively. Also, a higher incidence of more cephalad lumbar herniations and far lateral herniations was observed in older patients.