[Impaired cerebral autoregulation in asymptomatic patients with carotid artery stenosis: comparison of acetazolamide-SPECT and transcranial CO(2)-dopplersonography]. / Störung der zerebralen Perfusionsreserve.

PURPOSE: The indication for operation in patients with asymptomatic high-grade carotid artery stenosis is still under debate. Since impaired cerebrovascular autoregulation is associated with an increased risk for ischaemic events, assessment of cerebral vascular reactivity might be a valuable selection criterion for surgery. The aim of our study was therefore to evaluate the incidence of impaired autoregulation in asymptomatic patients with acetazolamide-single photon emission computed tomography (ACZ-SPECT) and transcranial CO (2)-dopplersonography (CO (2)-TCD). Furthermore, both methods were compared in regard to results and clinical practicability. METHODS: In 42 patients with high-grade (> 70 %) asymptomatic carotid artery stenosis, cerebral perfusion and vascular reactivity were assessed with resting and ACZ-enhanced SPECT scans. In 31 of these patients the CO (2) reactivity of cerebral perfusion was determined by TCD and expressed as normalized autoregulation reserve (NAR). RESULTS: Cerebral perfusion was decreased in 14.3 %. In ACZ-SPECT 26 % and in CO (2)-TCD 28 % revealed an impaired vascular reactivity. Conformity of both methods was high (kappa = 0.93). TCD was superior in practicability, but only applicable in 81 % due to a missing temporal bone window for insonation. CONCLUSION: In accordance ACZ-SPECT and CO (2)-TCD could detect impaired vascular reactivity in a quarter of asymptomatic patients. Both TCD and SPECT could be of value for preoperative selection in this group of patients, whereby sonography is recommended for daily diagnostic work-up.

[Sentinel lymph node diagnosis in prostatic carcinoma: II. Biokinetics and dosimetry of 99mTc-Nanocolloid after intraprostatic injection]. / Sentinel-Lymphknoten-Diagnostik beim Prostatakarzinom: Teil II: Biokinetik und Dosimetrie von 99mTc-Nanokolloid nach intraprostatischer Injektion.

AIM: To visualise the sentinel lymph nodes (SLNs) of the prostate we injected the radiotracer into the parenchyma of the prostate. The activity was deposited in liver, spleen, bone marrow, urinary bladder and regional lymphatic system. The aim of this work is to determine biokinetical data and to estimate radiation doses to the patient. METHODS: The patients with prostate cancer received a sonographically controlled, transrectal administration of 99mTc-Nanocoll, injected directly into both prostate lobes. In 10 randomly selected patients radionuclide distribution and its time course was determined via regions of interest (ROIs) over prostate, urinary bladder, liver, spleen and the lymph nodes. The uptake in the SLNs was estimated from gamma probe measurements at the surgically removed nodes. To compare tumour positive with tumour free lymph nodes according to SLN-uptake and SLN-localisation we evaluated 108 lymph nodes out of 24 patients with tumour positive SLN. For calculating the effective dose according to ICRP 60 of the patients we used the MIRD-method and the Mirdose 3.1 software. RESULTS: The average uptake of separate organs was: bladder content 24%, liver 25.5%, spleen 2%, sum of SLN 0.5%. An average of 9% of the applied activity remained in the prostate. The residual activity was mainly accumulated in bone marrow and blood. Occasionally a weak activity enrichment in intestinal tract and kidneys could be recognized. The effective dose to the patient was estimated to 7.6 microSv/MBq. The radioactivity uptake of the SLN varied in several orders of magnitude between 0.006% and 0.6%. The probability of SLN-metastasis was found to be independent from tracer uptake in the lymph node. The radioactivity uptake of the SLNs in distinct lymph node regions showed no significant differences. CONCLUSION: The radiotracer is transferred out of the prostate via blood flow, by direct transfer via the urethra into the bladder and by lymphatic transport. Injecting a total activity of 200 MBq leads to a mean effective dose of 1.5 mSv. It is not recommended to use the tracer uptake in lymph nodes as the only criterion to characterize SLNs.

[Sentinel lymph node diagnosis in prostatic carcinoma: I: Method and clinical evaluation]. / [Sentinel lymph node diagnosis in prostatic caricnoma: I: Technique and clinical evaluation]

AIM: Evaluation of the significance of lymphoscintigraphy and intraoperative probe measurement for the identification of the sentinel lymph node (SLN) in prostate cancer. PATIENTS AND METHOD: In 117 patients with prostate cancer scintigrams in various projections were acquired till approximately 6 hours p.i. after ultrasound guided transrectal intraprostatic injection of 99mTc-Nanocoll. On the following day the SLNs were identified in the operation theatre with a gamma probe and removed. Pelvic standard lymph node dissection followed SLNE. RESULTS: In three of 117 patients with preoperative lymphoscintigraphy no SLN was scintigraphically detectable. These three patients had antecedent transurethral resection of the prostate. In 113 of the residual 114 patients SLN could be intraoperatively localized. In the mean four SLNs per patient were removed. 28 of 117 patients had pelvic lymph node metastases. In 25 cases SLN were right-positive, in one false-negative and in one intraoperatively not detectable. In one patient we found macrometastasis of up to 4 cm diameter (one SLN was tumour positive). In 15 cases only the SLN was bearing tumour. CONCLUSION: The SLNE with preoperative lymphoscintigraphy and intraoperative gamma probe measurement is suitable for detecting lymph node metastasis in prostate cancer. SLNE is superior to the surgical techniques commonly used in pelvic lymphadenectomy.

Medical therapy or coronary artery bypass graft surgery for chronic stable angina: an update using decision analysis.

PURPOSE: Randomized trials comparing medical and surgical therapies for the treatment of chronic stable angina were completed in the early 1980s. Therapies developed since then have decreased mortality and myocardial infarction rates from coronary artery disease. Using decision analysis and incorporating current recommendations for treatment, we simulated a trial comparing coronary artery bypass graft surgery and medical therapy. METHODS: A Markov decision analysis model was constructed to compare the 5-year and 10-year outcomes of a simulated trial of medical therapy versus bypass surgery for stable chronic angina. Baseline data were obtained from a meta-analysis of trials comparing the two treatments. Data on risk reduction from contemporary therapies were obtained from randomized trials and meta-analyses. RESULTS: All subgroups experienced modest gains in survival with current therapies. At 5 years, the survival rate was 90% in the medical group (an absolute gain of 6%) and 94% in the surgical group (an absolute gain of 4%). Similar results were obtained for patients with triple-vessel disease. Among patients with a low ejection fraction, the 5-year survival rate was 85% for medical patients and 92% for surgical patients. Sensitivity analyses did not substantially affect the conclusions. CONCLUSION: Advances in the treatment of chronic stable angina have improved the outcome both for patients treated initially with surgery and for those treated initially with medical therapy. The improvements were of similar magnitude in both groups, so the fundamental conclusions of the bypass trials are unchanged.

Trends in treatment and outcomes for acute myocardial infarction: 1975-1995.

PURPOSE: To review the trends in treatment and survival for patients with acute myocardial infarction over the last 20 years. MATERIAL AND METHODS: Studies were identified through MEDLINE searches and review of study bibliographies. Additional data were obtained from the Health Care Financing Administration including data from Medicare claims files (part A). Thirty-day mortality rates were calculated using Medicare data and case fatality rates from the National Hospital Discharge Survey. Published meta-analyses were used to determine treatment effects. Published studies were included if they reported the use of therapies for acute myocardial infarction at a population level. Trends in the demographic characteristics of the patients as well as infarct characteristics, medication use, and revascularization were recorded. RESULTS: The use of acute treatments that are known to improve survival among patients with myocardial infarction has increased markedly during the last 20 years, leading to an estimated 9.6% reduction (from 27.0% to 17.4%) in 30-day mortality. After adjusting for potential interactions between therapies, the increase in use of aspirin, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, and reperfusion can explain 71% of the decrease in the 30-day age- and sex-adjusted mortality rate from 1975 to 1995. The greatest effect of a given therapy was that of aspirin, which accounted for 34% of the decrease in 30-day mortality, followed by thrombolysis (17%), primary angioplasty (10%), beta-blockers (7%), and ACE inhibitors (3%). If other treatments (such as heparin or nonprimary angioplasty), whose effects on mortality are less certain, are included, up to 90% of the decrease in 30-day mortality can be explained by changes in treatment. CONCLUSIONS: The primary reason for the decrease in early mortality from myocardial infarction during the last 20 years appears to be increased use of effective treatments.

Power Doppler imaging: initial evaluation as a screening examination for carotid artery stenosis.

PURPOSE: To evaluate power Doppler imaging as a possible screening examination for carotid artery stenosis. MATERIALS AND METHODS: In the principal pilot study, a prospective, blinded comparison of power Doppler imaging with duplex Doppler imaging, the reference-standard method, was conducted in 100 consecutive patients routinely referred for carotid artery imaging at a large, private multispecialty clinic. In the validation pilot study, a prospective, blinded comparison of power Doppler imaging with digital subtraction angiography, the reference-standard method, was conducted in 20 consecutive patients routinely referred at a teaching hospital. Using conservative assumptions, the authors performed cost-effectiveness analysis. RESULTS: Power Doppler imaging produced diagnostic-quality images in 89% of patients. When the images of the patients with nondiagnostic examinations were regarded as positive, power Doppler imaging had an area under the receiver operating characteristic curve, A(z), of 0.87, sensitivity of 70%, and specificity of 91%. The validation study results were very similar. The cost-effectiveness of screening and, as indicated, duplex Doppler imaging as the definitive diagnostic examination and endarterectomy was $47,000 per quality-adjusted life-year. CONCLUSION: The A(z) value for power Doppler imaging compares well with that for mammography, a generally accepted screening examination, and with most other imaging examinations. Power Doppler imaging is likely to be a reasonably accurate and cost-effective screening examination for carotid artery stenosis in asymptomatic populations.

[Clinical value of scintigraphy for gastrointestinal bleeding. Experiences in a large community hospital]. / Klinische Wertigkeit der gastrointestinalen Blutungsszintigraphie. Erfahrungen an einem grossen kommunalen Krankenhaus.

BACKGROUND AND OBJECTIVE: In the majority of cases of gastrointestinal bleeding the site and cause can be determined by gastroscope. If this is unsuccessful, radiological and nuclear-medical tests are available. This study was undertaken to determine the value of scintigraphy in diagnosing of the site of gastrointestinal bleeding. PATIENTS AND METHODS: The data on 155 patients who, between 1984 and 1988, had undergone 161 scintigraphies (with 99mTc-labelled erythrocytes, 5 with 99mTc-Sn colloid) were retrospectively analysed. The results were compared with other diagnostic tests that had been performed, with the definitive diagnosis and, where applicable, the findings at surgery. RESULTS: 78 scintigrams (47%) provided positive results. The site of bleeding had been demonstrated ca. 20 hours after the diagnostic studies had begun. In 47 of the cases the diagnosis was confirmed by additional tests. The intestine was the most common site of bleeding. Localization of the source of bleeding by scintigraphy and other diagnostic tests succeeded in 34 cases, with a 82% concordance between the tests. No bleeding was demonstrated in 88 scintigrams (53%), including all those done with Sn-colloid. In 13 cases the final diagnosis suggested that there had been no previous bleeding and in 43 cases the source of bleeding could not be determined. In 32 scintigraphically negative cases the source of bleeding was demonstrated by other tests. But only 2 of the 13 angiograms and none of the 33 double-contrast studies of the small intestine gave positive results. Among the total number of cases in which bleeding was demonstrated, scintigraphy had a sensitivity of 71%. CONCLUSION: Because of the long duration of observation, scintigraphy with 99mTc-labelled erythrocytes proved superior to other diagnostic tests in the demonstration of the bleeding. By localizing the source of bleeding in a definite part of the gastrointestinal tract, scintigraphy points the way to choosing other diagnostic methods or treatment. If the initial endoscopy has failed, scintigraphy, a method of low invasiveness, should be included when further tests are planned.

[Sentinel lymph node detection by preoperative lymphoscintigraphy and intraoperative gamma probe guidance in malignant melanoma]. / Nachweis des Sentinel-Lymphknotens mittels präoperativer Lymphszintigraphie und intraoperativer Gammasondenmessung bei malignem Melanom.

AIM: The purpose of this work was to prove the clinical significance of nuclear medical procedures in pre- and intraoperative detection of the SLN. METHODS: In the past 4 years, we did preoperative lymphoscintigraphy in 214 patients (pts.). Intraoperative localisation of the SLN with a hand-held gamma probe followed in 150 pts. RESULTS: In 214 pts. 247 lymphatic draining regions were found by preoperative scintigraphy. In 3 pts. with melanoma of the cheek no lymphatics/lymph nodes could be detected. 14 pts. showed interval lymph nodes. In 150 pts. gamma probe guided SLNE was done. In 2 pts. with supraclavicular primary tumor 4 SLN had been defined by preoperative scintigraphy but only 2 could be found intraoperatively. In all other cases (98.7%) the sentinel node was detected correctly by the gamma probe and then removed. In 19 of 150 pts. (12.7%) metastases were detected in the pathologic specimen. The incidence of lymph node metastases showed a continuous increase from 0% at tumor stage pT1 to 44% at stage pT4. CONCLUSION: SLNE is an accurate method to determine nodal involvement in melanoma and minimizes operative invasiveness in melanoma surgery.

Cost-effectiveness of screening for carotid stenosis in asymptomatic persons.

BACKGROUND: The Asymptomatic Carotid Atherosclerosis Study (ACAS) showed that carotid endarterectomy was beneficial for symptom-free patients with carotid stenosis of 60% or more. This finding raises the question of whether widespread screening to identify cases of asymptomatic carotid stenosis should be implemented. OBJECTIVE: To determine whether a screening program to identify cases of asymptomatic carotid stenosis would be a cost-effective strategy for stroke prevention. DESIGN: Cost-effectiveness analysis using published data from clinical trials. SETTING: General population of asymptomatic 65-year-old men. INTERVENTION: Patients who were screened for carotid disease with duplex Doppler ultrasonography were compared with patients who were not screened. If ultrasonography found significant carotid stenosis (> or = 60%), disease was confirmed by angiography before carotid endarterectomy was done. MEASUREMENTS: Quality-adjusted life-years, costs, and marginal cost-effectiveness ratios. RESULTS: When the conditions and results of ACAS were modeled and it was assumed that the survival advantage produced by endarterectomy would last for 30 years, the lifetime marginal cost-effectiveness of screening relative to no screening was $120,000 per quality-adjusted life-year. Sensitivity analysis showed that marginal cost-effectiveness decreased to $50,000 or less per quality-adjusted life-year only under implausible conditions (for example, if a free screening instrument with perfect test characteristics was used or an asymptomatic population with a 40% prevalence of carotid stenosis was found). CONCLUSIONS: Surgery offers a real but modest absolute reduction in the rate of stroke at a substantial cost. A program to identify candidates for endarterectomy by screening asymptomatic populations for carotid stenosis costs more per quality-adjusted life-year than is usually considered acceptable.

Prediction of outcome for critically ill patients with unexplained hypotension.

OBJECTIVES: To determine the clinical variables that affect the prognosis of critically ill patients with sustained unexplained hypotension. A further goal was to develop a prognostic scoring system based on clinical data available at the onset of hypotension. DESIGN: Prospective cohort study. SETTING: The intensive care units (ICUs) of an academic medical center. PATIENTS: One hundred one adult ICU patients with sustained (> 60 mins) unexplained hypotension. Using the initial 50 patients (derivation set), a prognostic score was developed that was then tested in the next 51 patients (validation set). INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: The main outcome variable was death or hospital discharge. The overall hospital mortality in the combined sets was 58%. Using a multivariable model we identified three independent (p < .05) predictors of hospital mortality, including the Acute Physiology and Chronic Health Evaluation (APACHE) II score at the time of hypotension, the time from hospital admission to hypotensive episode, and hospital admission for surgery or treatment of malignancy. These variables were weighted and combined to create a Hypotension Score which separated patients in the combined sets into three prognostic groups: a) Hypotension Score of < 40, mortality 7%, (n = 27); b) Hypotension Score of 40 to 64, mortality 70%, (n = 50); and c) Hypotension Score of > or = 65, mortality 92%, (n = 24). The area under the receiver operating characteristic curve was .85 for the derivation set and .83 for the validation set vs. .76 for the APACHE II score alone. CONCLUSIONS: The prognosis of hypotension in the critical care setting is highly variable, but can be predicted from patient characteristics.

Echocardiographic score as a predictor of in-hospital cost in patients undergoing percutaneous balloon mitral valvuloplasty.

Percutaneous balloon mitral valvuloplasty (PBMV) is an effective means of palliating mitral stenosis, but it sometimes leads to adverse clinical outcomes and exorbitant in-hospital costs. Because echocardiographic score is known to be predictive of clinical outcome in patients undergoing PBMV, we examined whether it could also be used to predict in-hospital cost. Preprocedure echocardiographic scores, baseline clinical characteristics, and total in-hospital costs were examined among 45 patients who underwent PBMV between January 1, 1992, and January 1, 1994. Patients ranged in age from 18 to 71 years and had preprocedure echocardiographic scores that ranged from 4 to 12. Following PBMV, mean mitral valve area increased from 1.1 +/- 0.3 to 2.4 +/- 0.6 cm2 (p = 0.0001), and mean pressure gradient decreased from 18.3 +/- 5.9 to 6.7 +/- 2.7 mm Hg (p = 0.0001). In-hospital cost for the 45 patients ranged from $3,591 to $70,975 (mean $9,417; median $5,311). Univariate and multiple linear regression analyses demonstrated that among the variables examined, echocardiographic score (p = 0.0007), age (p = 0.01), and preprocedure mitral valve gradient (p = 0.03) were associated with in-hospital cost. Regression modeling suggested that every increase in preprocedure echocardiographic score of one grade was associated with an increase in in-hospital cost of $2,663. Because echocardiographic score is predictive of both clinical outcome and in-hospital cost, we conclude that patients with elevated scores should be considered for alternative therapy.

Impact of the operating physician on costs of percutaneous transluminal coronary angioplasty.

The hospital charts and billing records of 250 consecutive admissions for percutaneous transluminal coronary angioplasty (PTCA) at a university hospital were reviewed. Clinical characteristics, performing physician, angiographic features of the dilated lesion, procedural outcome, length of stay, and total and departmental hospital costs were recorded for each patient. We identified several independent predictors of hospital cost, including the physician ($4,400 increase from highest- to lowest-cost physician, p=0.004), age ($790 increase per 10-year increase in age, p=0.002), urgency of the procedure ($4,100 increase for urgent vs elective, p < 0.001), and combined angiography and PTCA ($850 increase vs separate angiography, p=0.04). Independent predictors of catheterization laboratory cost included the physician ($1,280 increase from highest- to lowest-cost physician, p=0.03), American College of Cardiology/American Heart Association lesion type B2 or C ($320 increase, p=0.03), and combined angiography and PTCA ($430 increase, p=0.003). Expensive operators used more catheterization laboratory resources than inexpensive operators; however, there are no significant differences in success rate or need for emergent bypass surgery between physicians. PTCA cost is determined by both patient characteristics and the performing physician. The increase in cost due to the physician was not explained by patient variables, lesions characteristics, success rate, or complications.

[Interstitial radiotherapy with 125I seeds in non-operable and non-radioiodine retaining local recurrences of differentiated and undifferentiated thyroid cancers]. / Interstitielle Strahlentherapie mit 125I-Seeds bei nicht operablen und nicht radiojodspeichernden lokalen Rezidiven differenzierter und undifferenzierter Schilddrüsenkarzinome.

The use of interstitial radiation therapy in the treatment of local recurrence of anaplastic and other carcinomas of the thyroid is discussed on the basis of four cases. 125I seeds were used except in 1 case. All tumours showed no uptake of radioiodine and could not be completely removed by surgery. In three patients local control of the tumour was achieved (longest follow-up 41 months); one patient died 2 months after therapy due to local recurrence.

Contrast echocardiography: a method to visualize changes in regional myocardial perfusion in the dog model for CABG surgery.

The ability of contrast echocardiography to assess regional myocardial perfusion during cardiopulmonary bypass in a dog model for coronary artery bypass surgery was evaluated. Sonicated Renograffin-76 microbubbles (meglumin diatrigoate and sodium diatrigoate) were injected into an aortic root proximal to an aortic occlusion clamp root while dogs were on cardiopulmonary bypass, with the heart arrested in diastole. Echocardiographic contrast-enhanced regions of myocardial perfusion were easily visualized. Differences in contrast-enhanced myocardial regions depended on coronary artery occlusion or patency. The contrast-enhanced images of myocardial perfusion showed that, for a given myocardial segment of the supplying vessel, the presence or absence of contrast effect reliably predicted vessel occlusion or patency (P less than .01). In the future contrast echocardiography may allow the direct assessment of regional myocardial perfusion in the operating room.