Conversion factors for effective dose and organ doses with the air kerma area product in patients undergoing percutaneous transhepatic biliary drainage and trans arterial chemoembolization

Conversion factors used to estimate effective (E) and organ doses (H_T) from air Kerma area product (KAP) are required to estimate population doses in percutaneous transhepatic biliary drainage (PTBD) and trans arterial chemoembolization (TACE) interventional procedures. In this study, E and H_T for ten critical organs/tissues, were derived in 64 PTBD and 48 TACE procedures and in 14,540 irradiation events from dosimetric, technical and geometrical information included in the radiation dose structured report using the PCXMC Monte Carlo model, and the ICRP 103 organ weighting factors. Conversion factors of: 0.13; 0.19; 0.26 and 0.32 mSv Gy^-1 cm^-2 were established for irradiation events characterized by a Cu filtration of 0.0; 0.1; 0.4 and 0.9 mm, respectively. While a single coefficient of conversion is not able to provide estimates of E with enough accuracy, a high agreement is obtained between E estimated through Monte Carlo methods and E estimated through E/KAP conversion factors accounting separately for the different modes of fluoroscopy and the fluorography component of the procedures. An algorithm for the estimation of effective and organ doses from KAP has been established in biliary procedures which considers the Cu filtration in the X-ray irradiation events. A similar algorithm could be easily extended to other interventional procedures and incorporated in radiation dose monitoring systems to provide dosimetric estimates automatically with enough accuracy to assess population doses.

Delivery of selective internal radiation therapy complicated by variant hepatic vascular anatomy

“Difficult vascular anatomy” is a challenge for Interventional Radiologists especially in liver directed therapies such as trans arterial radio embolization.

Trans arterial radio embolization is a long and difficult procedure in which the basic knowledge of hepatic and gastro-enteric vascularization, with its high degree of variations, is very important in order to correctly administer the therapeutic drug selectively.

In this report, we present a case of an atypical patient affected by an unresectable hepatocellular carcinoma, candidate for Radio-embolization treatment.

His vascular anatomy was very difficult to manage, but the Interventional Radiologist was not only able to go over the “difficult anatomy,” but also to take advantage of it.

Hepatic artery aneurysm treatment with heparin-bonded covered stent: a case report

The hepatic artery is the second most common site for aneurysms formation within the splanchnic circulation. Most hepatic artery aneurysms (HAA) are diagnosed incidentally by a computed tomography(CT) scan or a Doppler ultrasonography. We present the case of a HAA diagnosed preoperatively in a 82-year old man, who was treated with an endovascular procedure. An abdominal ultrasonography revealed by chance the presence of a HAA. The abdominal CT scan confirmed an aneurysm of the common hepatic artery, specifically at the origin of the gastroduodenal artery. The gastroduodenal artery was embolized using coils then a heparin-bonded covered stent was deployed into the common hepatic artery to exclude the aneurysm. Final arteriogram documented the regular patency of the stent and the complete exclusion of the aneurysm. No complication occurred and the patient was discharged on the second postoperative day. Six months later, a follow-up with a Duplex scan confirmed the regular patency of the stent, and the patient was in good clinical conditions.

Abdominal aortic aneurysm treatment: minimally invasive fast-track surgery and endovascular technique

In our department we started a program in order to offer a mini-invasive approach to all patients affected by abdominal aortic aneurysms (AAAs), trying to offer this option also to patients not eligible for endovascular aneurysm repair (EVAR) due to unfavorable anatomy, age under 65 years and aorto-iliac occlusive disease, considering nowadays EVAR is the gold-standard for the mini-invasive treatment of AAAs. The aim of this study was to compare endovascular versus fast-track surgical treatment in patients undergoing elective surgery for AAAs. We wanted to verify if it was possible to be totally mini-invasive in the treatment of AAAs. A total of 128 patients were chosen for the study. Ninety-four patients were enrolled in the OPEN group and 34 were enrolled in the EVAR group. This study demonstrates that minimally invasive treatment with the fast-track protocol may be a valid alternative to EVAR.

[Prognostic stratification after acute uncomplicated myocardial infarction: exercise test, echo-dobutamine test or both?]

OBJECTIVES

The aims of this study were: 1) to assess the relative prognostic value of predischarge dobutamine echocardiography (DE) and exercise electrocardiography (EE) in patients after a first uncomplicated acute myocardial infarction (AMI), and 2) to evaluate the optimal prognostic strategy by using the two tests in different combinations.

METHODS

DE (dobutamine infusion 5 to 40 micrograms/kg/min plus atropine 0.25 to 1 mg, if needed) and symptom-limited bicycle EE were performed in 208 patients (mean age 58 +/- 9 years, 90% males), on different days and in random order, 12 +/- 4 days after a first uncomplicated AMI and after pharmacological washout. A stress-induced dyssynergy and ST segment depression > 1 mm were considered criteria of positivity for DE and EE, respectively. Only spontaneous cardiac events were considered: cardiac death, reinfarction (= hard events), and unstable angina requiring hospitalization (= soft events).

RESULTS

Thirty-eight events occurred during follow-up (16 +/- 13 months; range: 1-44 months); 5 cardiac deaths, 6 reinfarctions and 27 unstable angina. Patients with a positive DE had a twofold increase in all event rates (26 vs 12%, p < 0.01) and a fourfold increase in the rate of hard events (9 vs 2%, p < 0.05). In contrast, no statistically significant difference was observed in the distribution of the same events between patients with positive and negative EE. Both tests showed similar negative (DE 88%, EE 85%) and positive (DE 26%, EE 24%) predictive values. Among six different strategies (performing either DE or EE only in all patients; EE in all patients; EE in all patients and DE only in those with a positive EE; and DE only in those with a negative EE; EE in all patients and DE only in those with anterior AMI), EE only in patients with inferior or non-Q AMI and DE only in those with anterior AMI), performing DE only in patients with a positive EE gave the highest predictive accuracy-74% (95% confidence intervals 68 to 80) for all events and 77% (95% confidence intervals 71 to 83) for hard events.

CONCLUSIONS

In patients with a first uncomplicated AMI, DE is useful in identifying patients at high and low risk of future spontaneous cardiac events. The optimal strategy for prognostication of these patients is to perform EE in all and DE only in the ones with a positive EE.

Prognostic value of dobutamine echocardiography early after uncomplicated acute myocardial infarction: a comparison with exercise electrocardiography

OBJECTIVES

This study sought to assess the relative prognostic power of dobutamine echocardiography and exercise electrocardiography after acute myocardial infarction.

BACKGROUND

The prognostic value of dobutamine echocardiography early after acute myocardial infarction has not yet been reported.

METHODS

One hundred seventy-eight patients (mean age 58 +/- 9 years) with a first uncomplicated acute myocardial infarction underwent predischarge dobutamine echocardiography (5 to 40 micrograms/kg body weight per min, plus atropine if needed) and symptom-limited bicycle exercise electrocardiography and were followed up for 17 +/- 13 months. Stress-induced dyssynergy and ST segment depression > 1 mm were considered criteria of positivity for dobutamine echocardiography and exercise electrocardiography, respectively.

RESULTS

Dobutamine echocardiography was positive in 83 patients and exercise electrocardiography in 60. At follow-up there were 5 deaths, 6 nonfatal myocardial infarctions (11 hard events) and 20 cases of unstable angina. Dobutamine echocardiography and exercise electrocardiography had similar negative predictive values both for all events (88% and 86%, respectively) and for hard events (98% and 95%, respectively). The hard events rate was significantly higher in patients with positive rather than negative dobutamine echocardiography (relative risk [RR] 5.15, 95% confidence interval [CI] 1.14 to 23.16), although there was no difference between patients with positive and negative exercise electrocardiograms. When Cox analysis was performed, dobutamine echocardiography had an independent prognostic value both for all events (RR 2.88, 95% CI 1.37 to 6.08) and for hard events (RR 6.56, 95% CI 1.42 to 30.46).

CONCLUSIONS

After uncomplicated acute myocardial infarction, dobutamine echocardiography and exercise electrocardiography have a similar high negative predictive value for both all events and hard events only. Positive dobutamine echocardiography, but not positive exercise electrocardiography, identifies a group of patients at higher risk of subsequent cardiac events.

[Relationship between blood pressure determination anxiety and hypertensive complications]

To assess the clinical significance of the reaction to blood pressure measurement, 1,013 (889 men) borderline to severe hypertensive patients, enrolled between 1984 and 1993, were studied. Their mean age (+/- SE) was 33.6 +/- 0.46 (range 16-75 years) and their mean office blood pressure (+/- SE) was 152.3 +/- 0.56/95.5 +/- 0.39 mmHg. All subjects underwent ambulatory blood pressure monitoring, ECG and fundoscopy. On the basis of the latter two tests a target organ damage score was calculated, from 0 (no abnormalities) to 5 (maximum severity). In 731 patients an echocardiogram was also performed. The white-coat effect was assessed by measuring the regression of office blood pressure on ambulatory blood pressure and calculating the residual office blood pressure. The subjects with high residual blood pressure showed a greater degree of age-adjusted target organ damage compared to those with intermediate or low residual blood pressure (systolic p < 0.0001; diastolic p = 0.04). Age-adjusted left ventricular mass was influenced by residual diastolic blood pressure (p < 0.0001). In a stepwise multiple regression analysis, where age, ambulatory blood pressure levels, sex and duration of hypertension were added to the model, residual blood pressure showed a relationship with the degree of target organ damage and left ventricular mass. In conclusion, the present results show that the white-coat-effect is not innocent, as it is associated with a high degree of cardiovascular abnormalities.

[Clinical significance of blood pressure response to posture]

To assess the clinical significance of the blood pressure reaction to orthostatic posture, 55 normotensives and 369 subjects with different degrees of hypertension were studied with non-invasive 24-hour blood pressure monitoring. During the recordings blood pressure response to standing was evaluated at 8 a.m., and at 2, 4 and 7 p.m. All subjects were attributed a target organ damage score on the basis of ECG, chest x-ray and fundoscopic findings. To assess whether the orthostatic reaction may represent a marker for the severity of hypertension, subjects were divided into 4 classes of increasing blood pressure levels, and each class was further subdivided into two groups of subjects with orthostatic reaction above and below the mean value. On average, blood pressure rose by 2.7 +/- 9/7.2 +/- 7 mmHg while standing up, an increase which was inversely correlated to that of heart rate (p < 0.05). The orthostatic response was substantially constant throughout daytime hours. The systolic orthostatic change from lying to standing was directly correlated with age (p < 0.02) and average daytime blood pressure (p < 0.01), and inversely correlated with lying blood pressure immediately before standing up (p < 0.001). Both systolic (p < 0.05) and diastolic (p < 0.01) pressure responses to standing were related to the day-night blood pressure difference and to the standard deviation from mean daytime blood pressure. The degree of target organ damage was not significantly greater in the 4 groups of subjects with high orthostatic response compared to those with low response. The present results show that the pressure reaction to orthostatic stress is constant throughout daytime, even though a large intraindividual variability in the extent of the response is present. Orthostatic pressure change seems to be an important determinant of diurnal pressure rhythm, while it is not a marker for the severity of hypertension.

Clinical relevance of nighttime blood pressure and of daytime blood pressure variability

BACKGROUND

The purpose of this study was to assess whether hypertensive target organ damage is related to average nighttime blood pressure (BP) and to BP variability.

METHODS

Sixty-seven normotensive subjects and 171 borderline, 309 mild, 140 moderate, and 41 severe hypertensive patients were studied with noninvasive ambulatory BP monitoring. Each subject was assigned a target organ damage score of 0 to 5 on the basis of funduscopic changes and degree of left ventricular hypertrophy calculated from electrocardiogram and chest roentgenogram.

RESULTS

When the 728 subjects were subdivided into five classes of increasing daytime BP, in each class a significantly higher degree of target organ damage was present in the subjects with higher nighttime diastolic BP. A similar, although nonsignificant, trend was observed in the subjects with higher nighttime systolic BP. In particular, higher nighttime BP levels were accompanied by a more severe degree of left ventricular hypertrophy. As for variability, subjects with higher daytime systolic BP SD, but not with higher daytime diastolic SD, displayed a more severe degree of target organ damage; this was accounted for by a higher degree of retinal abnormalities. The association between target organ damage and systolic BP SD was present both in men and women, while that with nighttime BP was present only in men. No relationship was found between degree of cardiovascular complications and peaks of pressure.

CONCLUSIONS

These results suggest that a reduced day-night BP difference and an increased daytime BP variability, evaluated as the SD, are associated with a higher degree of hypertensive cardiovascular complications. Whether this BP profile is the cause or the consequence of target organ damage remains to be established.

Ambulatory blood pressure monitoring in the assessment of antihypertensive treatment: 24-h blood pressure control with lacidipine once a day

Ambulatory blood pressure monitoring gives a more representative blood pressure profile than office blood pressure measurements and is free of any placebo effect. It is therefore useful for studying the effect of antihypertensive agents. Although ambulatory blood pressure is less variable than office blood pressure, spontaneous fluctuations have been found in whole-day blood pressure when repeated measurements are taken. In the multicentre Triveneto Study, the mean difference between 24-h blood pressure recordings taken 3 months apart in 85 mild hypertensives was -0.1/-0.7 mmHg and the coefficient of repeatability (2 s.d.) was 17.3/12.6 mmHg. The corresponding values for office blood pressure were -8.7/-2.0 and 29.8/16.5 mmHg, respectively. This reduction in inter-measurement variability with ambulatory blood pressure monitoring makes it possible to reduce the sample size required to prove the effect of an antihypertensive agent in pharmacological trials. However, in the individual subject, the results of ambulatory blood pressure monitoring should be considered with caution, as 24-h blood pressure averages and profiles are subject to a degree of variability. This technique was used in 21 mild-to-moderate hypertensives to test the antihypertensive effect of lacidipine given once a day (4-6 mg) versus placebo. The drug proved effective throughout the day and night, showing a 24-h effect on blood pressure without reflex tachycardia or other intolerable side effects.

[Effect of high and low altitude exposure on the blood pressure response to physical exercise]

Altitude exposure is known to cause an increase in adrenergic activity, blood pressure (BP) and heart rate (HR) in resting conditions. Much less is known on the effects of the hypoxic environment on the BP and HR response to physical exercise. Five physically trained young normotensive subjects underwent a 1-hour long bicycle ergometric test to exhaustion at sea level and after 24 hours of low (1322 m) and high (3322 m) altitude exposure. HR, BP and Hb oxygen (HbO2) saturation were measured throughout the test and the recovery period. The values obtained at 60, 70, 80, 90 and 100% maximum HR were calculated. Resting BP increased by 17.9/20.9 mmHg at 3322 m (p = 0.062/0.012) and by 10.0/12.8 mmHg at 1322 m (NS). However, the BP difference present at rest gradually flattened throughout effort and at peak exercise similar BP values were obtained during the 3 tests. HbO2 saturation was lower at 3322 m compared to the other 2 settings (91.5% vs 96.7% at sea level; p less than 0.0001) and this difference progressively and remarkably increased throughout the ergometric test. At 3322 m a lower workload was reached (189 +/- 39.4 vs 240 +/- 54.8 W; p less than 0.05). In agreement with previous results these data show that exposure to both high and low altitude causes an increase in resting BP and HR; however, during strenuous exercise maximum BP and HR do not exceed the levels attained at sea level, probably on account of the lower workload that may be reached in the hypoxic environment.

[The normal limits of arterial pressure registered with portable methods: an approach to the problem]

In the present paper the problem of the normalcy limits of whole-day ambulatory blood pressure has been faced by evaluating the difference between casual and ambulatory blood pressure in a population of 522 subjects with blood pressure values covering the whole blood pressure range. On the basis of the casual blood pressure levels, 60 subjects were normotensives, 110 borderline hypertensives, 214 mild, 103 moderate and 35 severe hypertensives. The differences between casual and median 24-hour blood pressure averaged 18.4/9.6 mmHg. The difference between casual and median day-time was 14.2/6.7 mmHg. This difference was independent from the ambulatory blood pressure values and unrelated to the sex or age of subjects. The upper normal limits of ambulatory blood pressure were established by subtracting the above differences from the normal limits established by the WHO for casual blood pressure (140/90 mmHg). For 24-hour blood pressure the upper limits were 121.6/80.4 mmHg and for day-time blood pressure these were 125.8/83.3 mmHg. Contrary to previous studies conducted on normotensive populations with this approach the selection of patients based on casual blood pressure is avoided and the WHO normalcy limits are taken into account.

[Clinical significance of nocturnal blood pressure and blood pressure variability: analysis of 522 cases]

Purpose of the study was to investigate whether and to what extent blood pressure variability and average night-time blood pressure are related to cardiovascular complications in hypertension. To this aim 60 normotensive and 462 hypertensive subjects were studied by means of non-invasive 24 hour blood pressure monitoring, using either the Avionics, or the ICR Spacelabs, or the Takeda system. Each subject was attributed a target organ damage score on the basis of 12-lead electrocardiogram, chest X-ray and fundoscopy, starting from 0 (no damage) up to 5 (maximum degree of damage). The 522 subjects were subsequently subdivided into 5 classes of increasing average daytime diastolic blood pressure. In each class a higher degree of cardiovascular complications was present in the subjects with the higher blood pressure variability and the higher average night-time blood pressure. From these results it may be inferred that both blood pressure variability and night-time blood pressure are related to the degree of target organ damage in hypertension. This stresses the importance of recording blood pressure throughout the 24 hours.

[The pancreatico-respiratory syndrome. Problems of intensive therapy and illustration of 5 clinical cases]

A short account of the mechanisms responsible for pleuropulmonary affections in the course of pancreatitis is followed by the presentation of personal cases observed over the previous four years and reference is made to the relatively high frequency of pleuropneumopathy. Lastly, mention is made of the treatment of pancreatitis. Recent criteria lay down that this should be conservative and medico-intensive in the acute stage. Surgery should be left for cases of peritonitic abdomen (exploratory laparotomy) and chronic pancreatitis.

[Immediate treatment of pleuropulmonary complications of inflammations of the pancreas]

Seven cases of pancreatic pleuropneumopathy are presented and the relevant literature is examined. Treatment of this unusual complications is an offshoot of the modern management of the underlying disease. Attention is drawn to the possibility of serious and sudden acute chest pictures with a clinical picture reminiscent of pancreatic storm. Resuscitation, pneumological and surgical management is required. The histological data for the series shows that a pleural response to the action of matter excreted by the pancreas was responsible. Early local treatment and physiotherapy may be followed by a surprising degree of functional recovery.