Randomized clinical trial comparing scan-directed unilateral versus bilateral cervical exploration for primary hyperparathyroidism due to solitary adenoma.

BACKGROUND: It was shown in a previous retrospective study that scan-directed unilateral cervical exploration for primary hyperparathyroidism (HPT) can be carried out without an increase in the incidence of persistent or recurrent hypercalcaemia. This randomized clinical trial was conducted to test the hypothesis that focused unilateral operation leaves the patient no more vulnerable to persistent HPT than standard bilateral neck exploration. METHODS: Patients with HPT routinely underwent preoperative dual-isotope subtraction scintigraphy in an attempt to localize the presumed solitary parathyroid adenoma. Individuals with a positive scan (one residual focus of activity following subtraction) were deemed suitable for focused unilateral cervical exploration. At operation, if a single tumour was identified at the site suggested by the scan, the patient was randomized to unilateral or bilateral neck exploration. RESULTS: Between April 1998 and December 2003, 190 patients underwent first-time cervical exploration for HPT. Of these, 100 qualified for randomization. Fifty-four patients were randomized to unilateral neck exploration and 46 to bilateral operation. All 100 patients were cured following operation, as assessed by return of the serum calcium level to normal. Two patients randomized to bilateral exploration were found to have an unsuspected additional enlarged parathyroid on the contralateral side. CONCLUSION: Scan-directed unilateral cervical exploration for HPT does not significantly increase the incidence of persistent hypercalcaemia compared with standard bilateral operation.

Pre-operative sestamibi-technetium subtraction scintigraphy in primary hyperparathyroidism: experience with 156 consecutive patients.

AIM: The aim of this study was to assess the usefulness of pre-operative sestamibi-technetium subtraction scintigraphy in a large cohort of patients with primary hyperparathyroidism (HPT). MATERIALS AND METHODS: A group of 156 consecutive patients with biochemically proven HPT underwent sestamibi-technetium subtraction scintigraphy before cervical exploration. Images were interpreted and reported prospectively and influenced the extent of surgical exploration. The intraoperative findings were compared retrospectively with the pre-operative scintigram reports in 154 individuals with technically satisfactory scintigrams. RESULTS: Of the 154 patients with satisfactory scintigrams, 122 (78.2%) demonstrated a single focus of activity following subtraction, 31 (19.9%) had negative findings and the remaining scintigram showed four foci of activity. At operation 138 (89.6%) solitary adenomas were removed, 13 patients (8.4%) had multi-gland disease and in three individuals (2.0%) no abnormal parathyroid tissue was found. The pre-operative scintigram accurately localized 91 of 98 (92.9%) solitary tumours weighing > 500 mg but only 18 of 35 (51.4%) adenomas weighing < 500 mg, (P < 0.0001). Overall sensitivity of sestamibi-technetium scintigraphy for localizing single parathyroid adenomas was 83.7%. CONCLUSION: Sestamibi-technetium subtraction scintigraphy will accurately localize a high proportion of solitary parathyroid adenomas but its usefulness is diminished by its inability to consistently identify smaller tumours.

Emotional expression and feeling in schizophrenia: effects of specific expressive behaviors on emotional experiences.

The purpose of this study was to investigate the relationship between emotional expression and experience in schizophrenia by manipulating expressive behaviors directly and then assessing subsequent emotional feelings. In Study 1, facial expressions and bodily postures were manipulated in a sample of normals, the results of which replicate findings from previous studies of peripheral feedback effects on emotions. In Study 2, the same procedures were used with matched groups of outpatient schizophrenic men, patients with depression, and nonpsychiatric controls. Schizophrenia patients showed the usual effects from their facial expressions of sadness, fear, happiness, and surprise, but only from their postures of anger, whereas patients with depression showed the same effects only from their expressions and postures of sadness, and normal controls only from their expressions and postures of anger. These patterns may reflect those aspects of the emotional response system that are functional and dysfunctional in schizophrenia and depression.

Chronic pulmonary artery balloon counterpulsation in sheep via percutaneous route.

BACKGROUND: In clinical practice pulmonary artery balloon counterpulsation (PABC) has been utilized only in the operative setting with the balloon housed in a graft attached to the pulmonary artery. Clearly, percutaneous insertion of a dedicated pulmonary artery balloon is a desirable goal for patients requiring temporary assist for right ventricular failure. METHODS: To address the question of right sided cardiopulmonary tolerance for a chronic indwelling pulmonary artery balloon, six adult ewes underwent percutaneous placement of an 11 ml pulmonary artery balloon, via the femoral vein. Effective pumping and timing were monitored for 48 hours at which time the animals were sacrificed. At autopsy gross and microscopic study of all right heart structures, the pulmonary arteries and the lungs were studied for adverse effects. RESULTS: There were inconsequential minor abrasions to right heart structures in most animals. The pulmonary artery in five of six animals revealed ecchymoses and some transmural hemorrhage, but no necrosis or perforation. There was no pulmonary injury that could not be ascribed to postoperative atelectasis. CONCLUSIONS: This study demonstrates that chronic pulmonary artery balloon counterpulsation can be carried out for a period of 48 hours without significant injury to right heart and pulmonary structures in the ovine model

Localization of neuroendocrine tumours with [111In] DTPA-octreotide scintigraphy (Octreoscan): a comparative study with CT and MR imaging.

A wide variety of neuroendocrine tumours express somatostatin receptors, and can be visualized by radiolabelled somatostatin analogue scintigraphy. To investigate the value of [111In]-octreotide scintigraphy (Octreoscan), 48 patients (37 with proven carcinoid, pancreatic endocrine and medullary carcinoma of thyroid tumours, 11 with neuroendocrine syndromes multiple endocrine neoplasia (MEN-I) and Zollinger-Ellison syndrome (ZES) were examined with 111In-DTPA-D-Phe1-octreotide. Scintigrams were obtained at 24 and 48 h, and the results were compared with CT and magnetic resonance imaging (MRI). Thirty-five of 48 patients had positive [111In]-octreotide scintigraphy (23/25 (92%) carcinoids, 8/9 (89%) PETs, 4/11 (36%) MEN-I & ZES). Of the 42 lesions located by conventional imaging techniques, 37 (88%) were also identified by Octreoscan. Unexpected lesions (40 sites), not detected by CT or MR imaging were found in 24/48 (50%) patients. [111In]-octreotide scintigraphy has a higher sensitivity for tumour detection, and is superior to MR imaging and CT scanning in the identification of previously unsuspected extraliver and lymph node metastases. It may also be helpful for the localization of clinically suspected tumours in patients with MEN-I and ZES.

Accurate encoding and decoding of emotional facial expressions in schizophrenia.

This is a study of the encoding and decoding of emotional facial expressions by people diagnosed as schizophrenic. The results of most previous investigations have shown that schizophrenics are worse than other psychiatric and normal comparison groups at adopting and recognizing facial expressions of emotion. This study is the first in which both abilities were tested within the same group of outpatient subjects. In contrast to earlier findings, the results of this study indicate that this group of schizophrenics was equally proficient, as compared with unipolar depressive and normal medical control subjects, in the encoding and decoding of facial expressions of anger, sadness, fear, happiness, disgust, and surprise. Encoding and decoding responses in all three groups were largely unrelated. Some of the potential explanatory factors for these unusual findings include the older age of this sample and the use of a rating procedure in the decoding task that is more similar to the nature of decoding decisions made in social situations than those typically used by other investigators. The general conclusion that schizophrenics are deficient relative to comparison groups in the encoding and decoding of emotional facial expressions is not supported by these results.

The role of pre-operative thallium-technetium subtraction scintigraphy in the surgical management of patients with solitary parathyroid adenoma.

Since 1985 we have practised scan directed unilateral cervical exploration for patients with primary hyperparathyroidism (HPT) on the basis of a solitary parathyroid adenoma, and who had a pre-operative thallium-technetium subtraction scintigram demonstrating one focus of activity (positive scan). Between 1985 and 1993, a total of 160 patients with proven HPT and a technically satisfactory scintigram underwent neck exploration. Of these, 96 had positive preoperative scans, 81 (84.4%) of which accurately predicted the site of the tumour subsequently retrieved at operation. Seventy-four (77.6%) with positive scans, and 80 of the entire group, underwent unilateral cervical exploration with removal of a presumed single adenoma. Seventy-eight (97.5%) of these patients were cured of their HPT; two patients demonstrated mild persistent hypercalcaemia. Median operating time was significantly reduced for patients having unilateral as opposed to bilateral operation. Our results suggest that, when positive, thallium-technetium subtraction scintigraphy will accurately predict the site of a solitary parathyroid adenoma in a high proportion of patients and will thus permit a unilateral parathyroid exploration in these individuals. The usefulness of the technique is limited by its low sensitivity for small tumours.

Dynamic hepatic scintigraphy in the screening of psoriatic patients for methotrexate-induced hepatotoxicity.

We report the use of dynamic hepatic scintigraphy in the assessment of the hepatic status of psoriatic patients before and during methotrexate therapy. Eighty-seven paired dynamic scans and percutaneous liver biopsies were performed in 63 patients. The liver biopsies were graded according to Warin et al. with fibrosis of grade 2 or worse being a strong indication for withdrawal of methotrexate. The sensitivity of dynamic hepatic scintigraphy in detecting fibrosis of grade 2 or worse was 83.3% and the specificity was 81.5%. The predictive value of a normal scan for fibrosis of grade 0-1 was high (98.5%) although the predictive value of an abnormal scan for fibrosis of grade 2 or worse was low (25%). Dynamic hepatic scintigraphy may therefore offer a means to reduce the number of liver biopsies necessary in patients receiving methotrexate for psoriasis.

Scan-directed unilateral cervical exploration for parathyroid adenoma: a legitimate approach?

Thallium-Technetium isotope subtraction scanning was used routinely as a preoperative localization investigation in 90 patients with primary hyperparathyroidism who were submitted to "first-time" cervical exploration from 1985 to 1988. When the scintigram demonstrated a single focus of activity suggesting the site of a solitary parathyroid adenoma, a scan-directed exploration was carried out. If the tumor was found at the location suggested by the scan, it was then removed and the ipsilateral normal parathyroid was biopsied. The contralateral side of the neck was not explored in these patients. A total of 48 patients underwent unilateral cervical exploration while the remaining 42 individuals had a standard bilateral neck operation performed. The difference in operating times for patients who had a solitary adenoma and who underwent unilateral and bilateral neck exploration, respectively, was statistically highly significant (71 minutes versus 97 minutes, p less than 0.001). At mean follow-up of 16.8 months, no patient who had a unilateral neck exploration performed for solitary parathyroid adenoma demonstrated persistent or recurrent hypercalcemia.

Thallium-technetium isotope subtraction scanning in primary hyperparathyroidism.

Between January 1983 and March 1986, 75 consecutive patients underwent cervical exploration for primary hyperparathyroidism. Each patient had a thallium-technetium subtraction isotope scan of the neck performed preoperatively. Of 71 patients with technically satisfactory scans, 68 came to 'first-time' neck exploration while three underwent reoperation for persistent hypercalcaemia. At primary cervical operation 53 of the 68 patients each had a solitary adenoma as the cause of their hyperparathyroidism. In 28 (53%) of these individuals the scintigram accurately predicted the site of the parathyroid tumour ('helpful' scans). The technique was 'unhelpful' in 17 patients (32%) with false-positive scans and in eight patients (15%) with false-negative scans. There was a highly significant difference between the median weight of adenomas removed from patients with helpful scans (1.05 g) and that of adenomas retrieved from individuals with unhelpful scans (0.47 g), (P less than 0.001). Since 1 January 1985 we have adopted a policy of 'scan-directed' unilateral neck exploration for patients with hyperparathyroidism on the basis of solitary adenoma and in whom the isotope scan was positive. The mean operating time for these patients (n = 18, mean operating time 1.24 h) was significantly shorter than that for patients with unhelpful scans (n = 14, mean operating time 1.55 h, P less than 0.01) who were submitted to standard bilateral cervical operation. Subtraction scanning was helpful, in terms of localization of enlarged parathyroid glands, in only three of eight patients with multigland hyperplasia. The investigation was of positive help in locating the adenoma in two of three individuals submitted to cervical re-exploration for persistent hyperparathyroidism.

Quantification of arteriolar density and embolization by microspheres in rat myocardium.

We developed a technique for in vitro determination of arteriolar densities. Hearts, obtained from anesthetized rats and perfused by the Langendorff method, were fully dilated with adenosine and were arrested with an elevated potassium concentration. After a stabilization period, the hearts were perfused with a buffered fixative for some minutes to obtain a nonvital vasculature. After fixation, perfusion was switched back to control for some minutes. The hearts were then perfused with a medium containing a low concentration of microspheres: either pollen grains [Urtica dioica (15.4 microns), Betula (23.5 microns), or Phleum pratense (36.5 microns)] or polystyrene microspheres (15 microns). The perfusion was switched back to the standard medium after flow had been reduced to between 83 and 57% of control flow. Microscopic observations of microsections revealed that the percentages of arterioles embolized by one microsphere were 64% for the 15.4-microns, 74% for the 15-microns, 78% for the 23.5-microns, and 72% for the 36.5-microns microspheres. The percentages of arterioles embolized with two microspheres were 20, 15, 15, and 16%, respectively. The arteriolar densities were calculated from the total fractional reduction in coronary flow, the amount of microspheres injected, the wet heart weight, and the degree of occupancy, which corrects for the multiple embolization of the arterioles. The arteriolar densities in the rat hearts were 162.4 +/- 54.9 mg-1 (N = 6) for polystyrene microspheres of 15 microns, 161.5 +/- 81.1 mg-1 (N = 15) for 15.4-microns microspheres, 31.6 +/- 7.8 mg-1 (N = 9) for 23.5-microns microspheres, and 13.0 +/- 2.4 mg-1 (N = 8) for 36.5-microns microspheres.

99Tcm-MDP bone scanning of injuries of the carpal scaphoid.

Clinical injuries of the carpal scaphoid are frequently seen at accident and emergency departments. Some exhibit delayed radiographic visualization of a fracture. The radioisotope bone scan is a sensitive test and increased uptake is observed in healing fractures. Twenty-three patients with an initial diagnosis of clinical fractures of the scaphoid were studied clinically, radiologically and independently by 99Tcm-MDP isotope scans. Three-quarters of the patients required only 1 month's management. Their corresponding bone scans were normal or not suggestive of a fracture. The remaining 25 per cent, who clinically required a more prolonged treatment (greater than or equal to 5 weeks' immobilization), were noted independently to have positive scans whether a fracture was observed or not. It is concluded that there is a stronger correlation between clinical examination and a bone scan than with a standard radiographic examination. It is proposed that patients still tender at 3 weeks should have a carpal isotope bone scan to identify if there is an important wrist injury and appropriate treatment commenced.

What is the significance of the abnormal oesophageal scintigram?

In a review of 52 oesophageal scintigrams carried out in 46 patients with a variety of oesophageal problems, there was no correlation between the results of this test and the findings in other tests of oesophageal function, or between the scintigram results and the patients' symptoms, with the possible exception of regurgitation. We conclude that the test is of little value.

Indium-111 autologous leukocyte imaging in pancreatitis.

Thirty-nine patients with acute pancreatitis have been assessed using a prognostic factor grading system, abdominal ultrasound, and autologous leukocyte imaging. Both prognostic factor grading and leukocyte imaging can accurately assess the severity of the disease early in its course. All patients with a negative indium-labeled leukocyte image recovered without sequelae, whereas five of the 12 patients with a positive image developed complications, including two deaths. Abdominal ultrasound is of no value in assessing severity, but is a useful method of detecting those patients with gallstone-associated disease. In patients with suspected abscess formation following acute pancreatitis, indium leukocyte imaging does not differentiate between fat necrosis and abscess formation. In this situation, computerized tomography should be carried out before laparotomy is undertaken.

Coronary circulation in the presence of vascular disease.

This paper discusses three specific aspects of coronary circulation as they relate to the patient with coronary artery disease. Firstly, the normal autoregulatory and metabolic control of the coronary circulation is considered in the light of current understanding of the relevant processes. Secondly, the implications of microcirculatory heterogeneities are discussed. Thirdly, the implications of the current debate on the impact of cardiac contraction for our understanding of the perfusion of the myocardium in compromised circumstances are analysed in an attempt to provide the clinician with a tool for assessing current therapy.

Meta-iodobenzylguanidine in metastatic phaeochromocytoma.

A case of metastatic phaeochromocytoma is presented. Meta-iodobenzylguanidine was used to locate the tumour but failed to show two functioning abdominal metastatic deposits. Although meta-iodobenzylguanidine appears to be highly specific for phaeochromocytoma, a negative scan does not exclude a functioning tumour with confidence.

Oxygen and coronary vascular resistance during autoregulation and metabolic vasodilation in the dog.

The hypothesis that tissue oxygen tension controls coronary vascular resistance during changes in perfusion pressure and oxygen consumption was expressed in a simplified mathematical form capable of making quantitative predictions. The predictive value of this formulation of the hypothesis was tested in experiments on anaesthetized mongrel dogs subjected to constant-pressure perfusion of the left main coronary artery, with measurements of coronary blood flow and arterio-venous oxygen content differences. Coronary venous oxygen content was used as an index of tissue oxygenation. The responses of coronary blood flow and arterio-venous oxygen content difference, made over a range of perfusion pressures (which caused autoregulation) and heart rates (which caused metabolic regulation) were predicted qualitatively by the model. Coronary vascular conductance was positively related to metabolic rate only during metabolic regulation (heart rate changes); during autoregulation the relationship between these two variables was inverse. Coronary vascular conductance and resistance values taken from both interventions (both perfusion pressure and heart rate variations) were closely related to coronary venous oxygen content and calculated PO2. These findings suggest that further examination of oxygen tension, as the controller of the coronary vascular bed under physiological conditions should be considered.