High incidence of cardiovascular complications in pheochromocytoma

Excess of catecholamines in pheochromocytoma is usually accompanied with classical symptoms and signs. In some cases, severe cardiovascular complications (e. g., heart failure, myocardial infarction) may occur. We performed a retrospective analysis focused on the incidence of cardiovascular complications (classified as follows: arrhythmias, myocardial involvement or ischemia and atherosclerosis, cerebrovascular impairment) before the establishment of diagnosis of pheochromocytoma among 145 subjects treated in our hospital. Cardiovascular complications occurred in 28 subjects, but these subjects did not differ significantly from subjects without complications in age, gender, body mass index, paroxysmal symptoms, symptom duration, tumor dimension, catecholamine secretory phenotype, and incidence of hypertension or diabetes mellitus. Arrhythmias occurred in 15 subjects (2 arrhythmia types in 2 subjects): atrial fibrillation in 9 subjects, supraventricular tachycardia in 3 cases, and ventricular tachycardia in 2 patients. Significant bradycardia was noted in 3 cases. Five subjects presented with heart failure with decreased systolic function (takotsubo-like cardiomyopathy found in 2 cases). One subject suffered from hypertrophic obstructive cardiomyopathy. Seven subjects presented with non-ST-segment elevation myocardial infarction, 2 patients with ST-segment myocardial infarction, and 1 subject underwent coronary artery bypass grafting. Two subjects suffered from significant peripheral atherosclerosis. Among cerebrovascular complications, transient ischemic attack was found in 3 cases, 2 subjects suffered from stroke, and subarachnoidal bleeding occurred in 1 patient. One subject suffered from diffuse neurological impairment due to multiple ischemic white matter lesions. These data show relatively high incidence of cardiovascular complications (19.3%) in subjects with pheochromocytoma. Early diagnosis is mandatory to prevent severe complications in pheochromocytoma.

[Diagnostic of secondary hypertension in clinical practice]

Arterial hypertension is a common worldwide disease with a prevalence of approximately 26%. Secondary cause is known in 5-10% of patients with hypertension. We should think of secondary hypertension in all patients with resistant hypertension, in patients with sudden deterioration in the control of hypertension and in patients with laboratory and clinical signs of diseases associated with secondary hypertension. It is important to distinguish between secondary hypertension and pseudo-resistance (noncompliance to treatment, white coat syndrome). Secondary causes of hypertension can be divided into endocrine (primary aldosteronism, pheochromocytoma, hypercortisolism, hyperparathyreoidism), renal - renovascular and renal parenchymal hypertension, and other causes as sleep apnoe syndrome, hypertension in pregnancy, coarctation of the aorta and intracranial tumors.

Pulse wave velocity in primary hyperparathyroidism and effect of surgical therapy

The study was aimed at investigating the arterial stiffness assessed by aortic pulse wave velocity (PWV) in the presence of primary hyperparathyroidism (PH), with and without concomitant hypertension. Subsequently, we examined the effect of parathyroidectomy (PTX) on arterial stiffness. A total of 28 patients with PH and concomitant hypertension, and 16 with PH without hypertension were investigated in comparison with 28 essential hypertensive patients and 18 healthy controls, respectively. Patients were matched for age, blood pressure (BP), body mass index, lipid profile and fasting glucose. Six months after PTX, 15 patients were examined again (hypertensive as well as normotensive). PWV was obtained using the SphygmoCor applanation tonometer (AtCor Medical, West Ryde, Australia). PWV was significantly higher in patients with PH and hypertension when compared with patients with essential hypertension (10.1 vs. 8.5 ms(-1), P=0.013). PWV remained significant even after adjustment for age and BP (P=0.02). Similarly, PWV was significantly higher in PH patients without hypertension in comparison with healthy controls (7.6 vs. 5.8 ms(-1), P<0.001). Six months after surgery, in addition to a normalization of calcium metabolism, a significant decrease in systolic BP (131 vs. 123 mmHg, P=0.004) and PWV (9.1 vs. 8.5 ms(-1), P=0.024) was observed. After adjusting for BP reduction, the decrease in PWV appeared non-significant. Our data indicate that PH increases PWV as a marker of arterial stiffness, in both hypertensive and non-hypertensive patients. However, neither the calcium serum level nor the parathyroid hormone level has been associated with PWV. Specific treatment by PTX significantly decreases PWV, which may be determined primarily by improved BP control after surgery.

The prevalence of metabolic syndrome and its components in two main types of primary aldosteronism

Metabolic syndrome (MS) is frequent clinical condition in patients with hypertension. Primary aldosteronism (PA) is a common form of secondary hypertension. This study was aimed at investigating the prevalence of the MS and its components in the two major forms of PA, in unilateral aldosterone-producing adenoma (APA) and bilateral aldosterone overproduction because of idiopathic hyperaldosteronism (IHA). The diagnosis of the particular form of PA was based on adrenal venous sampling and/or successful surgery confirmed by histopathological examination. We analyzed clinical and laboratory data from 100 patients with PA (50 patients with IHA and 50 patients with APA) and from 90 patients with essential hypertension (EH). Metabolic profiles of patients with bilateral form of PA (because of IHA) were similar to EH, but differed from those in patients with unilateral form of PA (APA). The prevalence of the MS (62% in IHA, 34% in APA and 56% in EH), the body mass index value (30±4 kg m(-2) in IHA, 27±5 kg m(-2) in APA and 29±5 kg m(-2) in EH) and triglycerides levels (1.9±0.9 mmol l(-1) in IHA,1.4±0.8 mmol l(-1) in APA and 2.01±1.39 mmol l(-1) in EH) were all significantly (P<0.05) higher in IHA compared with APA patients. Metabolic profile of patients with bilateral form of PA (because of IHA) is similar to EH in contrast to unilateral form of PA (APA).

Factors influencing arterial stiffness in pheochromocytoma and effect of adrenalectomy

The aim of the study was to evaluate arterial stiffness and its modulating factors measured by carotid-femoral pulse wave velocity (PWV) and central augmentation index (AI) in patients with pheochromocytoma (PHEO) before and after surgery. Forty-five patients with PHEO and 45 healthy controls were investigated using an applanation tonometer (SphygmoCor, AtCor Medical). The gender, age, BMI and lipid profiles were comparable among both groups. The main difference in basic characteristic was as expected for fasting plasma glucose (P<0.001) and all blood pressure modalities. PWV in PHEO was significantly higher than in controls (7.2+/-1.4 vs. 5.8+/-0.5 ms(-1); P<0.001). Between-group difference in PWV remained significant even after the adjustment for age, heart rate, fasting plasma glucose and each of brachial (P<0.001) and 24 h blood pressure parameters (P<0.01). The difference in AI between groups did not reach the statistical significance (19+/-14 vs. 16+/-13%; NS). In multiple regression analysis, age (P<0.001), mean blood pressure (P=0.002), high-sensitive C-reactive protein (hs-CRP) (P=0.007) and 24 h urine norepinephrine (P=0.007) were independently associated with PWV in PHEO. In addition, 27 patients with PHEO were studied 1 year after tumor removal. Successful tumor removal led to a significant decrease in PWV (7.0+/-1.2 vs. 6.0+/-1.1 ms(-1); P<0.001). In conclusion, patients with PHEO have an increase in PWV, which is reversed by the successful tumor removal. Age, mean blood pressure, hs-CRP and norepinephrine levels are independent predictors of PWV.

Life-threatening arrhythmia caused by primary aldosteronism

BACKGROUND

Arrhythmias are one of the typical complications of primary aldosteronism (PA), is commonly characterized by hypertension and hypokalemia.

CASE REPORT

In this report, we present 3 cases of subjects in whom primary aldosteronism manifested with life-threatening arrhythmias. In 2 subjects, after excluding organic heart disease, an implantable cardioverter defibrillator was inserted and, only after the second episode of polymorphic ventricular tachycardia accompanied with low plasma potassium levels, the diagnosis of primary aldosteronism was made.

CONCLUSIONS

It is important to include diagnosis of primary aldosteronism in the diagnostic work-up of hypertensive subjects without any structural cardiovascular impairment who present with malignant arrhythmia and hypokalemia. Appropriate treatment of primary aldosteronism may avoid insertion of an implantable cardioverter defibrillator.

[Pheochromocytoma: diagnosis and treatment]

Pheochromocytoma (pheo) is adrenal or less frequently extraadrenal tumour of chromafine tissue. Pheos are rare, but cardiovascular and metabolic abnormalities are common. Unrecognised pheo may lead to fatal hypertensive crisis during anesthesia or other stresses. Proper diagnosis of pheo is thus of utmost importance. 24-h blood pressure (BP) monitoring may contribute to the diagnosis of pheo due to increased BP variability and absence of night BP decline. Pheo contains large amount of enzyme catechol-O-methyl transpherase (COMT) with subsequent excessive production of COMT metabolites like metanephrines. Measurement of plasma free metanephrines or urinary fraccionated metanephrines has usually higher sensivitivity and specificity compared with plasma or urinary catecholamines. Morphological diagnosis of adrenal/extraadrenal pheo is based on CT/MR visualisation and 123I-metaiodobenzylguanidin (MIBG) or PET 18F-fluorodeoxyglucose scan. Genetic analysis should be performed in all confirmed pheo cases, especially in younger subjects below 50 years of age in order to detect mutations of following genes: von Hippel-Lindau (VHL), RET- protooncogen, genes encoding B, C and D subunit of mitochondrial sukcinat dehydrogenaze (SDHB, SDHC, SDHD) and neurofibromatosis type I gene. Pharmacological treatment is based on alpha blockers with subsequent (after 24-48 hours) administration of beta-blockers/especially in patients with tendency to tachycardia/. Following this therapy normalisation of BP is common and laparoscopic excision of pheo tumour can be realised. Malignant pheos are difficult to treat due to early occurrence of metastasis and lack of response to chemotherapy or iradiation in most cases.

Adrenalectomy improves arterial stiffness in primary aldosteronism

BackgroundAldosterone has been shown to substantially contribute to the accumulation of different types of collagen fibers and growth factors in the arterial wall, which increase wall stiffness. We previously showed that arterial wall stiffness is increased in primary aldosteronism (PA) independently of concomitant hypertension. This study was aimed at assessing the effects of specific treatment of PA on the arterial stiffness.MethodsTwenty-nine patients with confirmed PA (15 with aldosterone-producing adenoma treated by unilateral laparoscopic adrenalectomy, 14 treated with spironolactone (mainly idiopathic aldosteronism) were investigated by Sphygmocor applanation tonometer (using measurement of carotid-femoral pulse wave velocity (PWV) and augmentation index (AI)) at the time of the diagnosis and then approximately 1 year after the specific treatment.ResultsThe office blood pressure (BP) decreased from 167 +/- 18/96 +/- 9 to 136 +/- 12/80 +/- 7 mm Hg after adrenalectomy (P = 0.001), and from 165 +/- 21/91 +/- 13 to 151 +/- 22/88 +/- 8 mm Hg (not significant (n.s.)) on spironolactone. The mean 24-h BP decreased from 150 +/- 18/93 +/- 11 mm Hg to 126 +/- 17/80 +/- 10 mm Hg after adrenalectomy (P < 0.01), and from 155 +/- 16/94 +/- 12 to 139 +/- 18/88 +/- 8 mm Hg (n.s.) on spironolactone. The PWV significantly decreased after surgery from 9.5 +/- 2.7 m/s to 7.6 +/- 2 m/s (P = 0.001), and the AI (recalculated for heart rate 75/min) decreased significantly from 27 +/- 10 to 19 +/- 9% (P < 0.01). On the other hand, we did not find significant change of arterial stiffness indices in patients treated with spironolactone (PWV: 9.3 +/- 1.6 m/s vs. 8.8 +/- 1.3 m/s (n.s.); AI: 25 +/- 9% vs. 25 +/- 8% (n.s.)).ConclusionsSurgical but not conservative treatment of PA led to a significant decrease of BP and arterial stiffness parameters.American Journal of Hypertension (2008). doi:10.1038/ajh.2008.243American Journal of Hypertension (2008); 21, 10, 1086-1092. doi 10.1038/ajh.2008.243.

Relationship between clinical, 24-hour, average day-time and night-time blood pressure and measures of arterial stiffness in essential hypertension

Arterial wall stiffness is considered an independent cardiovascular risk factor. Aim of this study was to evaluate relationship between clinical, 24-hour, average day-time and night-time blood pressure (BP) and measures of arterial stiffness assessed by pulse wave velocity (PWV) (using SphygmoCor applanation tonometer) in essential hypertension (severe-resistant (RH, n=29) and moderate hypertension (EH, n=35)) and in normotensive control subjects (n-29) (NCS) matched by age. After multiple regression analysis, PWV remains significantly correlated mainly with night-time pulse pressure and to a lesser extent with age. PWV was significantly higher in RH compared to moderate EH and NCS.

Increased intima–media thickness of the common carotid artery in primary aldosteronism in comparison with essential hypertension

BACKGROUND

Aldosterone contributes to the accumulation of collagen fibers and extracellular matrix in arterial wall. The aim of this study was to compare intima-media thickness (IMT) of the common carotid artery and carotid bifurcation in patients with primary aldosteronism, essential hypertension and healthy controls.

METHODS

Carotid ultrasound studies were carried out in 33 patients aged 42-72 years with primary aldosteronism, 52 patients with essential hypertension and in 33 normotensive controls.

RESULTS

The patients with primary aldosteronism had significantly higher IMT of the common carotid artery than patients with essential hypertension and controls (0.987 +/- 0.152 mm; 0.892 +/- 0.154 mm versus 0.812 +/- 0.124 mm; P < 0.001; P < 0.05). There was also significantly higher IMT of the common carotid in patients with essential hypertension compared to control group (0.892 +/- 0.154 mm versus 0.812 +/- 0.124 mm; P < 0.01). The differences between both hypertensive groups remained statistically significant after adjustment for age and 24-h systolic blood pressure (P = 0.001). The differences of the IMT in the carotid bifurcation were statistically significant only between patients with primary aldosteronism and controls (1.157 +/- 0.243 mm versus 0.994 +/- 0.199 mm; P <0.05).

CONCLUSION

Patients with primary aldosteronism have increased common carotid IMT compared to the patients with essential hypertension. This finding could be caused by the deleterious effects of aldosterone excess on the fibrosis and thickening of the arterial wall, mainly in the straight segments of vessels.

Impact of essential hypertension and primary aldosteronism on plasma brain natriuretic peptide concentration

INTRODUCTION

Brain natriuretic peptide (BNP) has important role in the diagnosis and management of heart failure. Data on the impact of blood pressure (BP) on BNP are controversial. In primary aldosteronism (PA), BNP production can be affected by both hypertension and specific endocrine mechanisms. This study was aimed at investigating the impact of hypertension and hyperaldosteronism on plasma BNP levels.

METHODS

Plasma BNP concentration, casual and 24-h BP and echocardiographic indices were assessed in 40 patients with moderate to severe essential hypertension (EH), 40 BP-matched patients with PA, and 40 age- and sex-matched healthy controls.

RESULTS

BNP levels in PA and EH groups did not differ significantly and were higher compared with those in controls [median and interquartile range 26 (13-48) pg/ml, p = 0.01, and 23 (9-32) pg/ml, n.s., vs 14 (6-26) pg/ml in controls]. Remarkably elevated BNP was observed only in three PA and two EH patients, all having significant left ventricular (LV) hypertrophy. BNP levels in PA and EH groups correlated weakly with casual and 24-h BP, interventricular septal thickness and LV mass index (LVMI). Diastolic BP and LVMI were identified as the strongest independent determinants of BNP (p = 0.002 and p = 0.01, respectively).

CONCLUSIONS

Both PA and EH patients had modest and mutually comparable elevation of BNP, which was independently determined by diastolic BP and LVMI. Both subtypes of PA (aldosterone-producing adenoma and bilateral adrenal hyperplasia) had similar effect on BNP production. Specific impact of hyperaldosteronism on BNP was not confirmed.

[Diagnostic and therapeutic procedures in pheochromocytoma: current trends]

Pheochromacytoma is a relatively rare cause of arterial hypertension. Untreated pheochromacytoma may however lead to a fatal hypertensive crisis during anaesthesia or another form of stress. It is therefore important to correctly diagnose this disease. 24-hour monitoring of blood pressure (BP) can already contribute to the diagnosis of pheochromacytoma based on the frequent occurrence of BP variability and the absence of a night-time fall in BP. 5 gene mutations have so far been identified that may be responsible for the familial form of pheochromacytoma: mutation of the von Hippel-Lindau (VHL) gene, leading to the onset of VHL syndrome, mutation of the RET-proto-oncogene in multiple endocrine adenomatosis type 2, mutation of the type 1 gene for neurofibromatosis, which is associated with von Recklinghausen's disease and finally mutation of the genes encoding the B and D subunits of succinated hydrogenase (SDHB, SDHD), which are associated with familial paragangliomas and pheochromacytoma. Genetic analysis should therefore be carried out for all confirmed cases of pheochromacytoma, especially for young people under 50 years of age. Biochemical diagnostics relies mainly on measurements of free metanephrines in plasma or urine, which usually has greater diagnostic weight than plasma, or catecholamines in urine. The diagnosis of extraadrenal or multiple forms can use not only CT/MR but also imaging using the radiopharmaceutical 123I-Metaiodobenzylguanidine (MIBG) or 18F-fluorodopamine PET (only available in the USA). Pharmacological treatment using alpha or beta receptor blockers with subsequent laparoscopic excision of the tumor is usually successful in benign forms of pheochromocytoma. Unfortunately, there are still no convincingly effective therapeutic procedures available for malign forms.

Elevated inflammation markers in pheochromocytoma compared to other forms of hypertension

OBJECTIVE

To investigate the effect of long-term catecholamine excess in pheochromocytoma on leukocyte and platelet count and on proteins of acute-phase response.

METHODS

Fifteen subjects with pheochromocytoma, 16 with primary aldosteronism, 18 with essential hypertension and 17 healthy controls were studied. Sixteen subjects with pheochromocytoma were investigated after tumor removal. Leukocyte, neutrophil and platelet count, as well as C-reactive protein were measured in all subjects, while fibrinogen, alpha(1)-antitrypsin, alpha(2)-macroglobulin, orosomucoid, transferrin and prealbumin were only measured in subjects with pheochromocytoma, primary aldosteronism and essential hypertension.

RESULTS

Subjects with pheochromocytoma showed significantly higher leukocyte [7.5 +/- 0.9 10(9)/l, p < 0.001 vs. primary aldosteronism (5.4 +/- 0.9 10(9)/l) and healthy controls (5 +/- 0.9 10(9)/l), p = 0.04 vs. essential hypertension (6.3 +/- 1.6 10(9)/l)], neutrophil (p < 0.001 vs. primary aldosteronism and healthy subjects) and platelet counts (p < 0.001 vs. primary aldosteronism; p = 0.01 vs. essential hypertension) compared to the other groups of subjects. Similar results were obtained for positive proteins of acute-phase response in subjects with pheochromocytoma [C-reactive protein: 0.62 +/- 0.52 mg/dl, p < 0.001 vs. healthy subjects (0.08 +/- 0.08 mg/dl), p = 0.001 vs. primary aldosteronism (0.17 +/- 0.19 mg/dl), p = 0.04 vs. essential hypertension (0.31 +/- 0.26 mg/dl); fibrinogen: p = 0.02 vs. primary aldosteronism; orosomucoid: p = 0.005 vs. primary aldosteronism; alpha(2)-macroglobulin: p = 0.009 vs. primary aldosteronism]. No significant differences were found in plasma levels of alpha(1)-antitrypsin, transferrin and prealbumin. Tumor removal led to a significant decrease in leukocyte (p = 0.004), neutrophil (p = 0.007) and platelet count (p = 0.003) and also to a significant decrease in acute-phase proteins (C-reactive protein: p = 0.03, fibrinogen: p = 0.008, alpha(1)-antitrypsin: p = 0.003, orosomucoid: p = 0.04).

CONCLUSIONS

Chronic catecholamine excess in pheochromocytoma is accompanied by an increase in inflammation markers which was reversed by the tumor removal.

Increased arterial wall stiffness in primary aldosteronism in comparison with essential hypertension

BACKGROUND

Aldosterone has been shown to substantially contribute to the accumulation of collagen fibers and growth factors in the arterial wall, which can increase wall stiffness. This study aimed at comparing arterial stiffness between patients with primary aldosteronism (PA), essential hypertension (EH), and normotensive controls using carotid-femoral pulse wave velocity (PWV) and central augmentation index (AI).

METHODS

Thirty-six patients with confirmed PA, 28 patients with EH, and 20 normotensive subjects were investigated by Sphygmocor applanation tonometer.

RESULTS

The office blood pressure (BP) at the time of the measurement (PA 167+/-34/92+/-12 mm Hg; EH 166+/-19/91+/-10 mm Hg), age, body mass index (BMI), cholesterol, triglyceride, blood glucose levels were comparable between PA and EH groups. The patients with PA had significantly higher PWV than the EH patients and control subjects (9.8+/-2.6 m/sec v 7.5+/-1.0 m/sec v 5.9+/-0.7 m/sec, respectively; all mutual differences P<.001). The difference in PWV between PA and EH remained statistically significant also after the adjustment for all clinical variables including 24-h BP using multivariate analysis (P=.001).

CONCLUSIONS

Arterial wall stiffness is independently increased in PA compared to EH. This could be caused by the deleterious effects of aldosterone excess (potentially modulated by hypernatremia) on the fibrosis and remodeling of the arterial wall.

Increased blood pressure variability in pheochromocytoma compared to essential hypertension patients

OBJECTIVE

Catecholamines are responsible for short and long-lasting blood pressure (BP) elevations in pheochromocytoma. We investigated whether in patients with pheochromocytoma this catecholamine excess would result in higher BP variability in comparison with patients suffering from essential hypertension (EH).

DESIGN

We examined retrospectively 54 (26 treated with alpha1-blockers) patients with pheochromocytoma (30 patients also investigated after tumour removal) and 108 (42 treated with alpha1-blockers) patients with EH. They all underwent 24-h ambulatory BP monitoring. To assess the BP variability, coefficient of BP variability (SD of average BP/average BP) was used.

RESULTS

In subjects with pheochromocytoma, a higher coefficient of BP variability was shown compared with EH during the 24-h period (0.12 +/- 0.03 versus 0.10 +/- 0.02, P = 0.003 for systolic BP in the treated group) and mainly during the daytime (0.11/0.13 +/- 0.04/0.03 versus 0.09/0.11 +/- 0.03/0.04, P = 0.007/0.06 for systolic/diastolic BP in the untreated group and 0.12/0.13 +/- 0.04/0.04 versus 0.09/0.12 +/- 0.04/0.02, P < 0.001/0.01 in the treated group). Tumour removal resulted in a decrease of the previously increased 24-h (0.11 +/- 0.03 versus 0.10 +/- 0.03, P = 0.04) and daytime (0.11 +/- 0.03 versus 0.09 +/- 0.03, P = 0.03) coefficient of systolic BP variation. Twenty-seven subjects with pheochromocytoma and inverted circadian BP rhythm (night-time BP > daytime BP) had a significantly higher 24-h (0.13 +/- 0.03 versus 0.10 +/- 0.03, P < 0.001 for systolic BP) and daytime coefficient of BP variation (0.13/0.15 +/- 0.04/0.03 versus 0.09/0.12 +/- 0.02/0.02, P < 0.001/<0.001) and also a higher occurrence of the isolated excretion of norepinephrine (14 versus seven subjects, P = 0.05) compared with the 27 subjects with pheochromocytoma without inverted circadian BP rhythm.

CONCLUSION

The excess of catecholamines in patients with pheochromocytoma is associated with higher long-term BP variability in comparison with patients suffering from EH especially in subjects with inverted circadian BP rhythm. Tumour removal resulted in the amelioration of the previously increased BP variability.

Biochemical markers of endothelial dysfunction in patients with endocrine and essential hypertension

The aim of our study was to evaluate potential differences in the concentration of biochemical markers of endothelial dysfunction between essential hypertension, endocrine hypertension (pheochromocytoma, primary hyperaldosteronism) and control healthy group and to assess a potential relationship between these markers of endothelial dysfunction and vasopressor substances overproduced in endocrine hypertension. We have investigated 21 patients with moderate essential hypertension, 29 patients with primary hyperaldosteronism, 24 subjects with pheochromocytoma and 26 healthy volunteers. Following parameters of endothelial dysfunction were measured, von Willebrand factor (vWf), plasminogen activator (t-PA) and E-selectin (E-sel). Clinical blood pressure was measured according to the European Society of Hypertension recommendations. We found significantly higher levels of the von Willebrand factor in patients with essential hypertension in comparison with a control group (114+/-20 IU/dl vs 90+/-47 IU/dl; P=0.04) and patients with primary hyperaldosteronism (114+/-20 IU/dl vs 99+/-11 IU/dl; P=0.01). Patients with endocrine hypertension revealed increased levels of vWF compared to the control group, but these differences did not reach statistical significance. Levels of t-PA were increased in patients with pheochromocytoma in comparison with the control group (4.6+/-1.9 ng/ml vs 3.4+/-0.9 ng/ml; P=0.01) and with primary hyperaldosteronism (4.6+/-1.9 ng/ml vs 3.4+/-1.1 ng/ml; P<0.01). In case of E-selectin we found lower levels in patients with pheochromocytoma in comparison with other groups, but they differed significantly only with primary hyperaldosteronism (40.2+/-15.0 ng/ml vs 51.3+/-23.0 ng/ml; P=0.05). Our study did not reveal any convincing evidence of differences in the levels of biochemical markers of endothelial dysfunction between essential and endocrine hypertension. No correlation between the biochemical markers of endothelial dysfunction and vasopressor substances activated in endocrine hypertension was found.

Does the treatment of primary hyperaldosteronism influence glucose tolerance?

Primary hyperaldosteronism (PH) is frequently considered to be a secondary form of diabetes mellitus (DM). In our previous study we attempted to evaluate the prevalence of DM among patients with PH compared to control subjects with essential hypertension (EH). We have noted a relatively high prevalence of DM and impaired glucose tolerance in PH, but the differences between the PH and EH groups did not reach statistical significance. We performed this study to assess whether the effective treatment of PH (surgical and conservative) would improve the glucose tolerance. We have studied 24 patients with PH of the following two subtypes: aldosterone-producing adenoma (APA) treated with adrenalectomy and idiopathic hyperaldosteronism (IHA) treated with spironolactone. No significant changes of glucose levels were found in the 60th and 120th min of the oral glucose tolerance test (OGTT) in the APA group. On the other hand, fasting glucose levels were decreased significantly after adrenalectomy. Plasma glucose levels were significantly increased in the 60th min, but no differences were found in fasting values and in the 120th min in the IHA group. There was a significantly higher incidence of impaired glucose tolerance (36 per cent before, 45 per cent after treatment) and DM (9 per cent, 18 per cent) in the IHA group compared to the APA group (8 per cent, 32 per cent; DM 0 per cent, 0 per cent). In conclusion, the treatment of PH does not improve glucose tolerance. Mild worsening of glucose tolerance after treatment could be explained by an increase of the body mass index. These data, in accordance with our previous study, do not support the idea that PH is a secondary form of diabetes mellitus.

Diurnal blood pressure variationin pheochromocytoma, primary aldosteronism and Cushing's syndrome

We examined circadian blood pressure (BP) variation (expressed as a relative night-time BP decline) in subjects with primary aldosteronism (78 patients), pheochromocytoma (n=45) and Cushing's syndrome (n=18). Subjects with aldosterone-producing adenoma (n=21) and pheochromocytoma (n=27) were also investigated after the tumour removal. In all, 65 patients with essential hypertension served as a control group. The night-time BP decline was significantly attenuated in all three forms of endocrine hypertension compared to the control group (primary aldosteronism P<0.0001, pheochromocytoma P<0.0001 for systolic and diastolic BP and Cushing's syndrome P<0.0001/<0.001 vs essential hypertension). In the case of pheochromocytoma, the absence of the night-time BP decrease was more prominent compared to the primary aldosteronism group (P=0.003/0.001) and for the diastolic BP also in comparison with the Cushing's syndrome group (P=0.03). Tumour removal led in both groups to the restoration of the previously altered circadian rhythm (aldosterone-producing adenoma: P=0.0005/0.0009; pheochromocytoma: P=0.001/0.0007). Our study demonstrates a blunted circadian BP variation in all forms of adrenal hypertension in comparison with essential hypertension. This reduction of the night-time BP decrease was more prominent in pheochromocytoma than in primary aldosteronism or Cushing's syndrome.

Prevalence of primary hyperaldosteronism in moderate to severe hypertension in the Central Europe region

Recently published studies from different parts of the world report significantly higher prevalence of primary hyperaldosteronism (PH) in hypertensives (ranging from 5 to 25%) than the previously accepted figures. There have been no data so far about the prevalence of PH in Central Europe. Therefore, we have undertaken this study to evaluate the prevalence of PH in patients with moderate to severe hypertension referred to a hypertension unit in the Czech Republic, together with the determination of the percentage of different subtypes of PH including familial forms. In addition to that, we have evaluated the prevalence of other types of secondary forms of hypertension.A total of 402 consecutive patients (230 females and 172 males) with hypertension, referred to our hypertension unit, were studied. Positive aldosterone/renin ratio (ARR, (ng/100 ml)/(ng/ml/h)) >/=50 as a more strict marker of PH was found in 87 patients (21.6%), 30% of them were normokalaemic. The diagnosis of PH was later confirmed in 77 cases (89%); the total prevalence of PH was thus 19%. PH consisted of the following forms: idiopathic hyperaldosteronism 42%, unilateral aldosterone-producing adenoma 36%, unilateral hyperplasia 7%, nonclassifiable PH (refused operation/adrenal venous sampling) 13%, familial hyperaldosteronism type 1.2%. The prevalence of other types of secondary hypertension was as follows: pheochromocytoma 5%, renovascular 4.5%, hypercortisolism 2%, renal 0.75%. In conclusion, we have noted that PH in the Central Europe region (Czech Republic) is the most frequent form of endocrine hypertension with a considerably high prevalence in moderate to severe hypertension. Application of more strict criteria raises the probability of correct diagnosis of PH including the early normokalaemic stages of PH.

Can primary hyperaldosteronism be considered as a specific form of diabetes mellitus?

Aldosterone-producing adenoma (aldosteronoma)--the most frequent form of primary hyperaldosteronism (PH)--is considered a specific form of diabetes mellitus (DM). In a previous study we demonstrated insulin resistance in patients with PH. We have therefore undertaken a study to evaluate the incidence of abnormalities of glucose metabolism in patients with PH (36 subjects) compared to control subjects with essential hypertension (EH) (21 patients). The following parameters were measured in all studied subjects: office blood pressure (by mercury sphygmomanometer in the sitting position), body mass index (BMI), plasma potassium, plasma glucose and insulin levels during oral glucose tolerance test (OGTT) (0, 60, 120 min), plasma renin activity and plasma aldosterone. Although patients with PH tended to have higher stimulated plasma glucose levels after 60 and 120 min compared to EH, these differences did not attain statistical significance. Patients with EH tended to have higher insulin levels at each measured interval, but due to a high variability these differences were again not significant. There were no significant differences between PH and EH in the proportion of diabetics (20% vs. 14%) or patients with impaired glucose tolerance (18% vs. 10%). In conclusion, we have found the absence of significant differences in the frequency of diabetes mellitus, impaired glucose tolerance and insulin resistance in patients with EH and PH. Our data thus do not support the idea of primary hyperaldosteronism as a specific type of diabetes mellitus. Furthermore, our results indicate that glucose metabolic characteristics in essential hypertension and primary hyperaldosteronism tend to be similar. The definitive conclusion with respect to the possible causal relationship between DM and PH, however, can be obtained only on larger groups of subjects, in particular after the evaluation of the effect of surgical/pharmacological treatment of primary hyperaldosteronism.

Autologous Schwann cells drive regeneration through a 6-cm autogenous venous nerve conduit

Peripheral nerve regeneration is a complex series of events, involving bi-directional interactions between regenerating axons and Schwann cells. These authors have demonstrated in their laboratory that nerves will regenerate through a 3-cm autogenous venous nerve conduit (AVNC) in an animal model and, with Dr. David Chiu, a similar distance in the human. They have shown that the upper limit of nerve regeneration in an empty AVNC was 3 cm, with no evidence of nerve growth at the 6-cm mark (no-growth model). Most recently, they have demonstrated rapid growth at 1 month in a 3-cm AVNC filled with Schwann cells, compared to poor-to-no-regrowth at 1 month in controls. While, in theory, Schwann-cell-derived growth factor should be sufficient to supplant the requirement for Schwann cells, in practice, therapies with growth factors have failed in clinical trials, with some resulting in severe morbidity and mortality for the subjects. The present study showed excellent nerve regeneration through a 6-cm AVNC with the addition of autologous Schwann cells, breaking the barrier in the previous no-growth model. In the first stage, autologous Schwann cells were harvested from the contralateral peroneal nerve of the rabbit and expanded in culture. The Schwann cells were purified to >99 percent homogeneity using differential adhesion and antibody-compliment-mediated cytolysis. In the second stage, 6 cm of gluteal vein were harvested and used as a conduit that was filled with either Matrigel or a slurry of Matrigel and 10(6)/ml autologous Schwann cells (n=6 control and 6 experimental animals). The non-donor side peroneal was exposed and transected, leaving a gap of 6 cm. The filled gluteal vein graft (AVNC) was then anastomosed to the proximal and distal peroneal nerve stumps, and the rabbits were allowed to recover. Four months postoperatively, the animals were subjected to transcardiac perfusion with EM grade fixative. The grafts were analyzed at the light and electronmicroscopic levels, and showed excellent growth of nerve at 6 cm, the distal end of the AVNC.

Effects of pulsed magnetic energy on a microsurgically transferred vessel

This article reports the findings of a study that attempted to elucidate whether pulsed magnetic energy stimulates neovascularization in vivo, using a microsurgically created arterial loop model in a prospective randomized trial of 108 rats (n = 12/group). Pulsed magnetic energies of 0.1 and 2.0 gauss were applied immediately postoperatively and for 4, 8, and 12 weeks, respectively, with a statistically significant increase in neovascularization among the treated animals compared with control rats. The study provides a starting point for future study and evaluation of the stimulation of angiogenesis with the use of pulsed magnetic energy and suggests a possible use of this modality to increase the quality of revascularized tissue.

Use of nerve conduits in peripheral nerve repair

Studies on nerve conduits for peripheral nerve regeneration have concentrated on the manipulation of various conduit materials to avoid sacrificing native nerve in the clinical situation. With the proliferation of available nerve growth-stimulating factors, the focus is shifting experimentally toward molecular biologic manipulation, with the addition of these materials as substrates within the conduit. The clinical use of conduits has concentrated on the use of autogenous tissue, with a few examples of polyglactin (PGA) mesh and silicone. Ultimately, as yet, conduit material does not seem to have a profound effect on outcome. Substrate manipulation has not yet had clinical application. An important problem that remains, both experimentally and clinically, is overriding the size of the maximal gap that can be bridged successfully, as well as obtaining good functional sensory and motor recovery, compared with the use of nerve grafts. Advances in molecular biology may reveal further details about the nerve growth phenomenon, the precise sequencing of the substrate materials that are effective in promoting nerve growth, and when they should be applied. Advances in chemical engineering may provide additional biologically stable materials that have the ability to integrate growth-enhancing agents or factors into the lumen of the conduit.

Delayed primary closure using Silastic vessel loops and skin staples: description of the technique and case reports

The use of Silastic vessel loops and skin staples for closure of surgical wounds, with or without tissue loss, is a relatively simple technique that can be done at the patient's bedside or in an office setting, using local anesthesia. The vessel loops are tightened or additional staples are placed, as required, until the skin edges are approximated. In a variety of wounds, use of Silastic vessel loops eliminates the need for skin grafting or secondary wound closure and minimizes the morbidity associated with these procedures.

Mammography in the evaluation of masses in breasts reconstructed with TRAM flaps

Patients with transverse rectus abdominis musculocutaneous (TRAM) flaps may develop physical findings, such as palpable masses, irregularities, and areas of increased tenderness that are suggestive of fat necrosis or recurrent malignancy. The purpose of this study was to evaluate these findings with mammography in an attempt to rule out recurrent malignancy in the autogenously reconstructed breast. Fifteen patients on whom mammography was performed as an aid in the evaluation of suspicious post-TRAM flap findings were reviewed. Common mammographic findings included calcifications believed to demonstrate fat necrosis, benign dermal calcifications, calcified hematoma, and clustered microcalcifications. Areas of increased or decreased density without calcifications were also identified and appeared to be related to surgical changes and fat necrosis. Twenty percent of patients had clustered microcalcifications, and 20% had detectable masses on mammography. One patient had a suspicious mass associated with clustered microcalcifications, leading to a biopsy that revealed fat necrosis. The majority of findings were consistent with normal fat within the TRAM flaps. This study supports mammography as a useful diagnostic tool in patients who have undergone TRAM flap breast reconstruction and who present postoperatively with suspicious physical findings.

A re-evaluation of hypopharyngeal reconstruction: pedicled flaps versus microvascular free flaps

Reconstruction of hypopharyngeal defects can be accomplished with the use of pedicled myocutaneous flaps or with microvascular free flaps. The authors contrast their results using the trapezoidal paddle pectoralis major myocutaneous flap with the reported results of two published series of free jejunal flaps. The severity of the defects, preprocedure irradiation, and mix of primary and secondary reconstruction were comparable between series. The benefits, complications, and functional results of either technique also seem to be comparable. However, the authors recommend the trapezoidal paddle pectoralis major myocutaneous flap for its ease of performance, rapidity of surgery, and absence of intraperitoneal approach. With the current effort to achieve comparable results with shorter procedures, and with greater conservation of patient and public resources, the pedicled flap should be reconsidered.

Analysis of bone formation after cranial osteotomies with a high-speed drill

Ten New Zealand white 22-week-old rabbits were divided into two groups of five each. The Midas Rex drill with a C-1 drill bit was used to make a full-thickness sagittal osteotomy 2 cm in length. A B-5 bit and footplate attachment were used to make a 2-cm linear osteotomy parallel to the first. Four drill holes 1 mm in diameter were made over the nasal bones on the ipsilateral side. In Group A animals, half of the skull had no irrigation; the other half of the skull was irrigated with room temperature saline. In Group B animals half of the skull was irrigated with iced saline irrigation; the other half of the skull was irrigated with room temperature irrigation fluid, and the osteotomy sites were filled with bone wax. Specimens were harvested at 8 weeks and evaluated grossly and histologically. The results showed that all the drill holes closed in the nasal bones regardless of the type of irrigation used or whether bone wax was used. Iced saline irrigation and room temperature irrigation had similar positive effects on bone formation in contrast to the no-irrigation group, which had inferior bone formation. Bone wax appeared also to have a detrimental effect on bone formation.

1457 years of microsurgical experience

Microsurgery is a relatively new field of surgery involving various methods and practices that are currently evolving. Our goal was to register the current practices employed by the members of the American Society for Reconstructive Microsurgery. A survey was mailed to the 319 members of the society, resulting in a response rate of 33 percent (106 of 319). The data reflect the combined experience of 10,839 free-tissue transfers and 3487 digital and upper and lower extremity replants over a 4-year period between 1990 and 1994. Practices employed, such as pharmacologic adjuvant therapy, monitoring techniques, flap types, and success rates reported by the members of the American Society for Reconstructive Microsurgery, were analyzed.

The ten test

The authors describe a new test for clinical sensibility, initiated in response to the need of the senior author for a rapid, reliable method to evaluate sensibility. Using this test, the patient develops a ratio between normal light moving touch and diminished moving touch. Subsequent determinations can detect serial changes. The ratios obtained can be compared with a standard scale of sensibility with a high degree of validity and reliability. The interexaminer and intraexaminer results obtained are reliable and repeatable. Statistical evaluations substantiating the validity of the test are presented. Simplicity and depend-ability recommend this test for use in a busy clinical setting.

Determining the maximal length of a vein conduit used as an interposition graft for nerve regeneration

Although autogenous veins have been used as nerve conduits (AVNCs) both experimentally and clinically for short nerve gaps up to 3 cm, investigators have not as yet determined the maximal effective length for functional nerve regeneration. In addition, the role of the distal nerve stump on subsequent nerve growth remains unclear. A rabbit peroneal nerve AVNC model was used to study axonal regeneration through nerve gaps of 1 to 6 cm. After allowing ample time for nerve regeneration, clinical, electophysiologic and neurohistologic studies were performed to evaluate nerve growth and functional muscle reinnervation. Comparisons were made with 6-cm conventional nerve grafts. Excellent growth and function were found with AVNCs up to 3 cm in length, with increasing incapacity for regeneration at lengths greater than 3 cm. The distal nerve stump is believed to play a vital role in nerve regrowth.

The effect of epigastric vessel ligation on the vascular territories of the pig rectus muscle

In a pig model, unilateral ligation of the inferior epigastric vessels caused an initial decrease in normal vascularity, followed by an increase toward normal vascularity, in the inferior portion of the rectus muscle over 42 days. Ligation appeared to dilate the choke vessels between the superior and inferior arterial territories. The results indicate that by ligation of the inferior epigastric vessels, the vascular territory, which is normally tenuous, can undergo a transposition without vascular compromise.

Free fibula flap mandible reconstruction for oral obstruction secondary to giant fibrous dysplasia

Fibrous dysplasia is a disorder of bone that may be associated with endocrinopathies and skin pigmentation. The pathologic, proliferative expansion and distortion of the skeleton is of unknown etiology. Craniofacial involvement that includes the mandible can exhibit gigantic disproportions and dysfunction. Treatment has evolved to include more aggressive strategies of resection and sophisticated reconstructive techniques. The reported case is noteworthy for the unrelenting growth of craniofacial fibrous dysplasia in an adult female with endocrinopathies, progressing to oral obstruction that required urgent treatment utilizing immediate free bone-flap reconstruction. The free fibula flap was employed to restore mandibular continuity after palliative subtotal mandibulectomy. Bony healing to dysplastic tissue occurred in the remaining mandibular segment. This case illustrates that fibrous dysplasia has the capacity for virulent regrowth subsequent to conservative resection. Defects following radical surgery for giant fibrous dysplasia of the mandible can be reconstructed with a microsurgical bone-flap technique.

[Video technology and the personal computer in the therapy simulator]

PURPOSE

Technical progress in the development of radiation therapy simulators provided valuable addition of electronically stored images and monitor indicators for individual radiation parameters. One can store as well as print these data as a treatment plan. The possibility of supplementing older simulators with these technical options will be reported in the following paper.

METHODS

The modification of our simulator installation was done simply. The new equipment needed to expand our simulator facility was almost exclusively derived from the fields of entertainment and home electronics (Visualizer/video camera, video tape recorder, video mixer, additional monitor; personal computer and printer).

RESULTS

With these modifications we reached the technical standards of the latest simulator generation. In addition, we succeeded in implementing additional technical options: e.g. image inversion with contrast alignment to diagnostic displays, complete magnetic tape recording of the entire x-ray process with possible repetition, electronic overlapping of the simulator image and the diagnostic image (e.g. NMR; angiograms) to determine the treatment volume, automation in x-ray documentation.

CONCLUSION

Increased precision and rational work steps employing readily available equipment will lead to further improvement in the quality of radiotherapy.

Monobloc correction of external nasal deviations

Nine patients (7 men, 2 women) with external nasal deviation underwent corrective procedures using a monobloc nasal osteotomy technique. The deformities ranged from mild to severe. Eight patients had post-traumatic deviations, whereas 1 had a unilateral cleft nasal deformity. For this monobloc technique, osteotomies were performed at unequal levels to correct the height difference, no periosteal undermining was performed, and septal dissection was undertaken only after monobloc repositioning. There was no need for grafts or microplate fixation. Minimum follow-up was 8 months. All patients had improvement in their external deviation, 1 patient was mildly undercorrected, and only 1 patient (cleft nasal) required a radical submucosal resection.

Pharyngeal flap revisions: flap elevation from a scarred posterior pharynx

Twenty-one consecutive patients who had earlier superiorly based pharyngeal flap surgery and persistent velopharyngeal insufficiency were seen between 1976 and 1991. Patients were divided into two treatment groups, depending on the results of videofluoroscopic and nasopharyngoscopic assessment. The first group consisted of 18 patients who had bilateral port insufficiency and required a complete reconstruction of a new superiorly based pharyngeal flap that was elevated from a scarred posterior pharyngeal wall. After an average follow-up of 6.2 years, 15 patients had normal resonance, 2 patients had improvement but continued hypernasality, and 1 patient was hyponasal. The second group consisted of 3 patients who had "patch" flaps to a unilateral port insufficiency. Postoperatively, all 3 of those patients had normal resonance. Indications for the decision to "redo" or patch flaps are described.

The use of pentoxifylline in microvascular surgery

The authors studied the effect of pentoxifylline (Trental), a hemorrheologic agent that increases erythrocyte flexibility and augments microcirculatory blood flow, on the patency of a known thrombosis model. In Sprague-Dawley rats, a double-blind study was performed, with animals receiving either intraperitoneal injections of pentoxifylline (20 mg/kg/day) or saline in an equivalent volume, 4 weeks prior to surgery and continued for 1 week postoperatively. In all animals, the left femoral artery was used for a 2-mm arterial inversion graft (AIG), and the contralateral femoral artery for a 2-mm crush injury model. In the control group, patency of the AIG was 0 percent (0/19) and that of the crush model 31 percent (6/19). The pentoxifylline-treated group showed an AIG patency of 37 percent (7/19) and a crush model patency of 84 percent (16/19). p values were .004 and .005, respectively. Furthermore, hematoma formation was associated with none of the control sides (0/38) and only with 5 percent (2/38) of the pentoxifylline-treated animals. This study demonstrated statistically significant improvement on microvascular patency in animals treated with pentoxifylline, whether they were in the crush or the arterial inversion graft groups. The clinical ramifications of using a hemorrheologic agent that improves microvascular circulation, without effecting changes in coagulation, are apparent.

Distraction of the frontal bone outside the cranial plane: a rabbit model

Distraction of the frontal bone outside the cranial plane using the Ilizarov principle was performed in 17 22-week-old New Zealand white rabbits. Five rabbits had frontal bone osteotomy only and were in the control group; 5 rabbits were placed in the sham control group and had frontal bone osteotomy plus application of a customized headgear appliance; and 7 rabbits were placed in the experimental group, which underwent frontal bone osteotomy application of the headgear and distraction. The frontal bone was elevated 1 mm every other day for a period of 8 weeks, and the animals were then killed. Cephalometry was performed both preoperatively and at the end of the 8-week period. Histological examination of the skulls was also performed. The experimental group showed a significantly elevated frontal bone compared to the sham control group (p < 0.05). Callous bone filled the distracted segment, which united the frontal bone with the cranial plane. Therefore, frontal bone advancement by distraction osteogenesis is possible using this rabbit model.