Thomas K. Pilgram

Natural History of Stenosis From Intracranial Atherosclerosis by Serial Angiography

BACKGROUND AND PURPOSE Knowledge of the natural history of stenoses due to intracranial atherosclerosis may be useful for evaluating possible treatments such as angioplasty. METHODS We retrospectively reviewed records over a 7-year period to identify patients with intracranial atherosclerotic stenoses and serial angiograms. Quantitative measurements of stenoses were made in a blinded manner, and clinical outcomes were reviewed. RESULTS We identified 21 patients with 45 intracranial stenoses who underwent repeat angiography at an average interval of 26.7 months. The average stenosis for all intracranial lesions was 43.9% initially and 51.8% on follow-up (P=.032). The average stenosis in the intracranial internal carotid artery (ICA) was stable (51.2% versus 52.6%). The average stenosis in the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) progressed from 32.4% to 49.7% (P=.037). Based on a minimum 10% change, 20% of intracranial ICA lesions progressed compared with 61% of ACA, MCA, and PCA lesions. Regression occurred in 14% of the intracranial ICA group and 28% of the ACA-MCA-PCA group. Cerebrovascular events were infrequent during this period, with 4 transient ischemic attacks and 1 intracerebral hemorrhage. CONCLUSIONS Intracranial atherosclerotic stenoses are dynamic lesions demonstrating both progression and regression.

Long-Term Outcome After Chemoembolization and Embolization of Hepatic Metastatic Lesions from Neuroendocrine Tumors

OBJECTIVE Hepatic artery chemoembolization and hepatic artery embolization (HAE) are accepted treatments of patients with hepatic metastasis from neuroendocrine tumors. Long-term outcome data are limited. We present our experience in the use of hepatic artery chemoembolization in the treatment of patients with hepatic metastasis from neuroendocrine tumors. MATERIALS AND METHODS Forty-six patients with carcinoid (n = 31) or islet cell (n = 15) tumors were treated. Overall and progression-free survival times starting with the first treatment were calculated. Potential factors affecting survival, including presence of extrahepatic disease and resection of the primary lesion, were analyzed. Relief of symptoms was subjectively determined for tumors with hormonal secretion. RESULTS The 46 patients underwent 93 hepatic artery chemoembolization or HAE sessions. The mean overall survival time for the entire group was 1,273 +/- 185 days. The mean overall survival times for the carcinoid (1,255 +/- 163 days) and islet cell tumor (1,311 +/- 403 days) subgroups were similar (p = 0.66). The progression-free survival times for the carcinoid (602 +/- 144 days) and islet cell (501 +/- 107 days) tumor subgroups also were similar (p = 0.72). The survival time of patients without known extrahepatic metastasis (n = 18; 1,571 +/- 291 days) trended toward significance compared with that of patients with known extrahepatic disease (n = 26; 770 +/- 112 days; p = 0.08). Resection of the primary tumor in 19 of 46 patients did not affect survival (resection survival, 1,558 +/- 400 days; nonresection survival, 1,000 +/- 179 days; p = 0.44). Twenty of 25 patients with hormonally active tumors had relief of symptoms after one cycle of treatment. The 30-day mortality was 4.3%. CONCLUSION The overall survival time after hepatic artery chemoembolization or HAE among patients with neuroendocrine tumors is approximately 3.5 years. The progression-free survival time approaches 1.5 years. The presence of extrahepatic metastasis or an unresected primary tumor should not limit the use of hepatic artery chemoembolization or HAE.

Sagittal craniosynostosis outcome assessment for two methods and timings of intervention.

A retrospective quantitative analysis of 40 infants who underwent surgery for sagittal craniosynostosis was conducted to determine whether any difference in outcome, with respect to cranial index (cranial width/cranial length x 100), could be associated with either the age at surgery or the extent of the operation. Children < or = 13 months old at surgery and for whom there were archived computed tomography digital data preoperatively, perioperatively, and 1 year postoperatively were studied. For statistical analysis, the operation was classified as either extended strip craniectomy or subtotal calvarectomy, and the age at operation was either < or = 4 months or > 4 months. Twenty-eight patients underwent extended strip craniectomy at a mean age of 5.1 months. Their mean cranial index preoperatively was 67 versus 71 at 1 year postoperatively (p < 0.0001). Of extended strip craniectomy patients, 15 were operated on at age < or = 4 months (mean = 2.9 months) and 13 at age > 4 months (mean = 7.6 months). Mean cranial indices for age at operation groups did not achieve age-appropriate normal range values 1 year postoperatively for either group, and there was no significant difference between the mean percentages of improvement achieved (p = 0.143). Twelve patients underwent subtotal calvarectomy at a mean age of 5.2 months. Their mean cranial index preoperatively was 66 versus 74 at 1 year postoperatively (p < 0.0001). The mean cranial index in this group reached age-appropriate normal range values 1 year postoperatively. The percentage improvement in cranial index 1 year after subtotal calvarectomy was greater than after extended strip craniectomy (p = 0.003). Extended strip craniectomy for sagittal craniosynostosis does not achieve normal cranial width:length proportions, even when performed before 4 months of age. Subtotal calvarectomy for sagittal craniosynostosis does achieve normal cranial width:length proportions in the majority of the children, at least when performed within the first 13 months of life.

Speech, cognitive, and behavioral outcomes in nonsyndromic craniosynostosis

Background: The neuropsychological morbidity of nonsyndromic craniosynostosis is incompletely understood. The purpose of this study was to establish the prevalence of speech-language, cognitive, and behavioral abnormalities in this population and to stratify the findings on the basis of the affected suture and age of diagnosis with speech-language or psychological abnormalities. Methods: Charts of all patients with nonsyndromic craniosynostosis evaluated between 1978 and 2000 were reviewed, noting diagnoses of speech-language, cognitive, or behavioral abnormalities. Findings were statistically analyzed for variance with regard to affected suture and diagnosis of abnormalities. Results: Two hundred fourteen patients with nonsyndromic craniosynostosis had documented follow-up evaluations with an average age of 6 years 4 months at last visit. Speech, cognitive, and/or behavioral abnormalities were manifest in 49 percent of the patients with specific rates for each suture as follows: right unilateral coronal, 61 percent; bilateral coronal, 55 percent; multiple, 47 percent; metopic, 57 percent; left unilateral coronal, 52 percent; lambdoid, 44 percent; and sagittal, 39 percent. This prevalence of abnormalities was a statistically significant increase from the general population. Logistic regression demonstrated that as patient age increased, the percentage of abnormal diagnoses also increased. Conclusions: Nonsyndromic craniosynostosis is often associated with cognitive, speech, and/or behavioral abnormalities. The etiopathology of this association is unknown. Furthermore, the proportion of children diagnosed with cognitive and behavioral dysfunction increases with age. Therefore, longitudinal cognitive, behavioral, and speech assessment and treatment are integral to the care of these patients.

Effect of antiplatelet therapy on thromboembolic complications of elective coil embolization of cerebral aneurysms.

BACKGROUND AND PURPOSE: Thromboembolic events are the most common complications of elective coil embolization of cerebral aneurysms. Administration of oral clopidogrel and/or aspirin could lower the thromboembolic complication rate. MATERIALS AND METHODS: Records over a 10-year period were reviewed in a retrospective cohort study. For 369 consecutive elective coil embolization procedures, 25 patients received no antiplatelet drugs, 86 received antiplatelet drugs only after embolization, and 258 received antiplatelet drugs before and after embolization. RESULTS: Symptomatic thromboembolic complications (transient ischemic attack or stroke within 60 days) occurred in 4 (16%) of 25 when no antiplatelet drugs were given, in 2 (2.3%) of 86 when antiplatelet drugs were administered only after embolization, and in 5 (1.9%) of 258 when antiplatelet drugs were administered before and after embolization. The lower symptomatic thromboembolic complication rate in the patients who received any antiplatelet therapy was statistically significant (P = .004). Clots were visible intraprocedurally in 5 (4.5%) of 111 when no antiplatelet drugs were administered before procedures and in 4 (1.6%) of 258 when they were (P value not significant). None of the 9 was symptomatic postprocedurally, but 7 were lysed or mechanically disrupted. Extracerebral hemorrhagic complications occurred in 0 (0%) of 25 when no antiplatelet drugs were given and in 11 (3.2%) of 344 when they were (P value not significant). CONCLUSION: Oral clopidogrel and/or aspirin significantly lowered the symptomatic thromboembolic complication rate of elective coil embolization of unruptured cerebral aneurysms. There were trends toward a lower rate of intraprocedural clot formation in patients given antiplatelet drugs before procedures and a higher hemorrhagic complication rate in patients given antiplatelet drugs. Benefits of antiplatelet therapy appear to outweigh risks.

Quantifying Effects of Plaque Structure and Material Properties on Stress Distributions in Human Atherosclerotic Plaques Using 3D FSI Models

BACKGROUND Atherosclerotic plaques may rupture without warning and cause acute cardiovascular syndromes such as heart attack and stroke. Methods to assess plaque vulnerability noninvasively and predict possible plaque rupture are urgently needed. METHOD MRI-based three-dimensional unsteady models for human atherosclerotic plaques with multi-component plaque structure and fluid-structure interactions are introduced to perform mechanical analysis for human atherosclerotic plaques. RESULTS Stress variations on critical sites such as a thin cap in the plaque can be 300% higher than that at other normal sites. Large calcification block considerably changes stress/strain distributions. Stiffness variations of plaque components (50% reduction or 100% increase) may affect maximal stress values by 20-50%. Plaque cap erosion causes almost no change on maximal stress level at the cap, but leads to 50% increase in maximal strain value. CONCLUSIONS Effects caused by atherosclerotic plaque structure, cap thickness and erosion, material properties, and pulsating pressure conditions on stress/strain distributions in the plaque are quantified by extensive computational case studies and parameter evaluations. Computational mechanical analysis has good potential to improve accuracy of plaque vulnerability assessment.

Hepatic arterial chemoembolization for hepatocellular carcinoma: comparison of survival rates with different embolic agents.

PURPOSE The optimal embolic agent for transhepatic arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) has not been identified. This study reports outcomes of TACE for HCC with Gelfoam powder and polyvinyl alcohol (PVA). MATERIALS AND METHODS Eighty-one patients underwent 152 TACE sessions with Gelfoam powder (n = 41) or polyvinyl alcohol (PVA) and Ethiodol (n = 40) as the embolic agent. Chemotherapeutic drugs were the same for all patients (50 mg cisplatin, 20 mg doxorubicin, 10 mg mitomycin-c). The groups were compared based on number of TACE sessions, maximum tumor size, bilirubin level, aspartate and alanine aminotransferase levels, Child-Pugh score, Model for End-stage Liver Disease score, and hepatitis B or C virus positivity. The number of cases of each Child class in each group was also evaluated. Survival starting from the first TACE session was calculated according to Kaplan-Meier analysis. Forty-eight patients died during the study period, 19 received transplants, and 14 were alive at the end of the study period. RESULTS The groups were statistically similar in all categories regarding liver function, Child-Pugh score, tumor size, hepatitis status, and percentage of patients with Child class A, B, and C disease. The number of TACE sessions was significantly greater for the Gelfoam powder group (mean, 2.2) versus the PVA group (mean, 1.6; P = .01). Overall survival was similar between groups whether patients who received transplants were included in the analysis (mean, 659 days +/- 83 with Gelfoam powder vs 565 days +/- 71 with PVA; P = .42) or were excluded (mean, 519 days +/- 80 with Gelfoam powder vs 511 days +/- 75 with PVA; P = .93). CONCLUSION In similar patient groups, survival after treatment of HCC with TACE with Gelfoam powder or PVA and Ethiodol was similar.

Validation of Magnetic Resonance Imaging (MRI) multispectral tissue classification

The application of NASA multispectral image processing technology for analysis of Magnetic Resonance Imaging (MRI) scans has been studied. Software and hardware capability has been developed, and a statistical evaluation of multispectral analysis application to MRI scans of the head has been performed.

the Effect of Surgeon Experience on Velopharyngeal Functional Outcome following Palatoplasty: Is There a Learning Curve?

&NA; There is little information in the cleft palate literature concerning the relationship between surgeon volume and clinical outcomes. It is unknown whether such a relationship applies specifically to velopharyngeal dysfunction and the need for secondary physical management of the velopharynx. The purpose of this paper was to explore the concept of an operative learning curve for different surgeons with respect to palatoplasty. Impact of case volume and procedure type on the occurrence of secondary palatal management (the main outcome measure) was assessed. The charts of 472 consecutive palatoplasty patients were reviewed by one speech and language pathologist to determine when the palatoplasty was performed, which surgeon (n = 9) performed the palatoplasty, whether velopharyngeal status was documented at a minimum of 6 years of age, and whether secondary palatal management was prescribed. The results were analyzed by year of palatoplasty, by surgeon, and by number of operations per surgeon to determine total and individual surgeon rates of secondary palatal management. There were 401 palatoplasties (85 percent recovery) with adequate documentation of velopharyngeal status by at least 6 years of age. Palatoplasty rates ranged between 1 and 258 palatoplasties per surgeon. Over the 12 years reviewed, secondary palatal management was performed for 92 patients (23 percent) of the study population. Examination of the proportion of palatoplasty patients receiving secondary palatal management by surgeon and by year showed only one surgeon with a pattern suggesting a learning curve. The proportion of patients receiving secondary palatal management was plotted against the total number of surgeries the surgeon performed. There was a strong relationship between experience and success. The number of procedures this surgeon performed per year increased at approximately the same time as the success rate improved. The categories of “total procedures” and “procedure per year” were highly correlated with each other. Success rates were analyzed by number of procedures performed per year, and there was a clear association between the two variables. To separate the effect of the two variables, a multiple regression model was constructed. The category of “total procedures” was statistically significant in the model, whereas procedures per year was not, suggesting that the key to the dominant surgeons improvement was cumulative experience rather than frequency of performance of the operation. Palatoplasties performed by high‐volume surgeons are more likely to result in better postoperative outcomes (i.e., lower rates of secondary palatal management) as compared with palatoplasties performed by low‐volume surgeons. The influence of the surgeons cumulative experience on improvement seems to be more important than the frequency of performance of primary palatoplasty. (Plast. Reconstr. Surg. 102: 1375, 1998.)

Comparison of computed tomography myelography and magnetic resonance imaging in the evaluation of cervical spondylotic myelopathy and radiculopathy

STUDY DESIGN A cross-sectional retrospective radiologic study. OBJECTIVES To establish concordance rates between interpretations of computed tomography myelography and magnetic resonance imaging in patients with degenerative cervical spine disease. SUMMARY OF BACKGROUND DATA Observed discrepancies in interpretation of computed tomography myelography and magnetic resonance imaging question the reliability of comparisons between these two methods. METHODS This study blindly and randomly evaluated cervical computed tomography myelography and magnetic resonance imaging in 20 patients referred for clinically diagnosed cervical spondylotic radiculopathy, myelopathy, or both. The discovertebral joints, facet joints, lateral recesses, cord size, spinal canal, and neural foramina also were evaluated with graded scales. All results were subjected to the kappa statistic for strength of agreement. RESULTS Agreement for interpretation of the discovertebral junction occurred in 144 of 240 sites (60%), indicating only moderately good intermethod concordance (kappa = 0.44). Intermethod agreement on the characterization of facet joint disease was only moderately good (143 of 160 sites; 89.4%; kappa = 0.52), and on characterization of lateral recess disease was poor (125 of 160 sites; 78.1%; kappa = 0.20). On degree of spinal canal compromise, there was agreement within one grade in 199 of 240 sites (82.9%; kappa = 0.42). Intermethod agreement on neural foraminal encroachment and cord size was only moderately good (kappa = 0.42 and 0.46, respectively). Computed tomography myelography tended to upgrade the spinal canal narrowing and neural foraminal encroachment. CONCLUSIONS For most parameters of interpretation, the degree of concordance between computed tomography myelography and magnetic resonance imaging is only moderately good, with discrepancies noted especially in the differentiation of disc and bony pathology. These methods should be viewed as complementary studies.