CT- or sonography-guided biopsy of the liver in the presence of ascites: frequency of complications

The presence of ascites has been considered a contraindication to percutaneous biopsy of the liver. To determine the validity of this assumption, we performed percutaneous biopsies of the liver under CT or sonographic guidance in 28 patients who had ascites and in 28 patients who did not have ascites and compared the complication rates in the two groups. Twenty-two patients (79%) in the group with ascites and 19 patients (68%) in the group without ascites had biopsies to determine the cause or extent of chronic liver disease. The remainder were oncologic patients who had biopsies to determine the cause of a focal hepatic mass. The complication rate in the patients who had ascites (32%) was less than that in the patients who did not have ascites (43%) (the difference did not reach statistical significance, p less than .30). In the ascites group, complications included transient hypotension (five patients), a mild-to-moderate fall in hematocrit (three patients), and a small leak of ascites from the biopsy site (one patient). In the control group, minor complications included transient hypotension (three patients), a mild-to-moderate fall in hematocrit (seven patients), and a small subcapsular hematoma (one patient). One major complication occurred in the control group: a patient required a blood transfusion because of the fall in his hematocrit. We conclude that the complication rate in liver biopsies guided by CT or sonography in the presence of ascites is not higher than similar biopsies done in the absence of ascites. Ascites should not be considered a contraindication for performing such biopsies.     

Functional innervation of the striatum by ventral mesencephalic grafts in mice with inherited nigrostriatal dopamine deficiency

Weaver mutant mice are characterized by a decrease in striatal dopamine (DA), which is associated with a progressive loss of DA neurones in the substantia nigra. This mutant thus provides the opportunity to examine the functional effects of DA neurones grafted to the striatum in a genetic model of parkinsonism. Ventral mesencephalic tissue from normal foetuses was placed on the surface of the right dorsal striatum of adult weaver mutants. After grafting, animals were tested for methamphetamine-induced circling behaviour. Mutants with DA containing grafts displayed a significant circling bias toward the left, non-grafted side. Mutants without grafts did not display any rotational bias to either side. These results demonstrate that grafted DA containing neurones establish a functional innervation of the weaver striatum and suggest that grafting of neural tissue is a viable approach in restoring function in genetic degenerative disorders of the nigrostriatal system.     

Comparison of iohexol 300 and diatrizoate meglumine 60 for body CT: image quality, adverse reactions, and aborted/repeated examinations.

Six hundred patients were prospectively randomized and given either diatrizoate meglumine 60 or iohexol 300 during dynamic contrast-enhanced body CT in order to compare image quality, contrast reactions, and the number of aborted studies or studies in which images had to be repeated. Three hundred two patients received iohexol 300, and 298 patients received diatrizoate meglumine 60. Thirty-nine percent (119/302) of the patients given iohexol 300 and 63% (188/298) of the patients given diatrizoate meglumine 60 had at least one adverse reaction thought to be related to contrast material during, or within 24 hr of, the body CT scan. When reactions of discomfort (heat or warmth, flushing, bad taste) were excluded, 16% (48/302) of the patients who received iohexol and 33% (99/298) of the patients who were given diatrizoate meglumine 60 had at least one adverse reaction. The differences in both types of reactions between the two agents were significant (p less than .001). Among scans evaluated for study quality, 71% (214/302) of the iohexol 300 group and 62% (184/298) of the diatrizoate meglumine 60 group had optimal enhancement (p = .02). However, when the optimal and adequate categories were combined, 301 of 302 patients given iohexol 300 and 292 of 298 patients given diatrizoate meglumine 60 had diagnostic-quality studies (no statistical difference). Studies were not terminated nor were images repeated in 97% (292/302) of the patients given iohexol 300 and in 94% (280/298) of those given diatrizoate meglumine 60. The CT study was repeated because of movement during the contrast injection or aborted because of contrast-related reactions in 0.7% of the patients given iohexol 300 and in 3.0% of the patients given diatrizoate meglumine 60. This difference was statistically significant (p = .04). Our results suggest that the difference in image quality, number of adverse reactions, and number of aborted/repeated CT scans performed with iohexol 300 or diatrizoate meglumine 60 are not sufficiently different to warrant conversion to nonionic agents for body CT scans.     

Transesophageal echocardiography-guided cardioversion of atrial fibrillation. Selection of a low-risk group for immediate cardioversion.

INTRODUCTION: In patients (pts) with atrial fibrillation (AF) of more than 48 hours' duration, electrical cardioversion (ECV) should only be performed after 3 weeks of effective anticoagulation. Transesophageal echocardiography (TEE) allows earlier ECV; however, despite exclusion of thrombi in the atrium and left atrial appendage (LAA), cases of thromboembolism related to ECV have been documented in AF. To define a low-risk group for cardioversion without previous anticoagulation, pts were selected for immediate ECV if no thrombi or dynamic spontaneous echo contrast (auto-contrast) were found after TEE and if LAA velocity was more than 0.25 m/sec. METHODS AND RESULTS: We performed TEE in 31 consecutive pts referred for ECV for AF of more than 48 hours' duration and without previous anticoagulation. After TEE the pts eligible for immediate ECV began anticoagulation with low molecular weight heparin (enoxaparin), subcutaneously in therapeutic doses, together with warfarin immediately before cardioversion. Enoxaparin was continued until an INR of over 2 was reached. Based on the TEE findings, the pts were divided in 2 groups: immediate ECV, group A, 20 pts with a mean age of 62 +/- 13 years, 6 female; and conventional therapy with warfarin before ECV, group B, 11 pts, mean age of 67 +/- 10 years (p < 0.05), 2 female. None of the pts in either group had mitral stenosis or previous episodes of thromboembolism. The mean transverse diameter of the left atrium in the 31 pts was 47 +/- 4.5 mm, without statistically significant differences between the 2 groups. Of the 11 pts in group B, 3 had a thrombus in the LAA, 6 dynamic spontaneous echo contrast and the remainder LAA velocities of less than 0.25 m/sec. ECV was achieved in all the pts, with no complications. Oral anticoagulation was maintained for at least a month. At one month, sinus rhythm was maintained in 75% of group A and 45% of group B (p < 0.01). CONCLUSION: In pts with AF of more than 48 hours' duration and no previous history of thromboembolism, the use of our exclusion criteria during TEE enabled stratification of a low-risk population for immediate ECV, which was accomplished effectively and safely in 2/3 of the pts. This strategy is associated with early symptomatic improvement, and may contribute to maintenance of sinus rhythm after one month, which was significantly better than in the pts who had prolonged therapy with warfarin before ECV, despite the differences found in age and left ventricular function.     

Blood Flow Increase by Cervical Spinal Cord Stimulation in Middle Cerebral and Common Carotid Arteries

The effect of spinal cord stimulation (SCS) on cerebral blood flow (CBF) has, in the past, been evaluated by semiquantitative techniques, but has not been used to treat CBF diseases. The aim of this study was to assess the effect of cervical SCS on regional blood flow by both semiquantitative and quantitative methods. Thirty‐five patients with cervical SCS‐implanted devices were enrolled. The following parameters were measured before and after cervical SCS: systolic and diastolic velocity (cm/s) in the middle cerebral artery (MCA) by transcranial Doppler (TCD) and volume blood flow quantification (ml/min) in the common carotid artery (CCA) by color Doppler. During cervical SCS there was a significant and bilateral increase in systolic (21%) and diastolic (26%) velocity in the MCA and in CCA blood flow (50%). We conclude that cervical SCS increases blood flow in the middle cerebral artery and common carotid artery. The consistent increase supports the potential usefulness of cervical SCS as an adjuvant treatment for cerebral blood flow diseases.     

Interventional computed tomography

Due to the development and refinement of computed tomography (CT), sonography, and interventional techniques, the field of interventional radiology has seen tremendous growth in recent years. In particular, the precise anatomic detail provided by CT and sonography has allowed percutaneous biopsies and abscess drainages to be performed safely and effectively. Percutaneous biopsies are now becoming the most common interventional radiographic procedures in many institutions. The usual indications for a biopsy are to determine the etiology of a mass, neoplasm, or inflammation, and to determine whether masses in known oncologic patients represent scarring or residual viable tumor. Accuracy rates for most percutaneous CT-directed biopsies are well over 90%, and the complication rate is very low. CT-directed percutaneous abscess drainages are also safe and effective and, in most cases, will be preferable to surgical drainage. The initial indications for percutaneous drainage (single, unilocular fluid collections) have been greatly expanded to include multiloculated collections, interloop abscesses, periappendiceal abscesses, and even percutaneous cholecystotomies. Biopsy and drainage procedures, together with their accuracy rates, indications and complications, are reviewed in this monograph.     

Generation and survival of midbrain dopaminergic neurons in weaver mice

Generation and survival of midbrain dopaminergic (DA) neurons were investigated using tyrosine hydroxylase (TH) immunocytochemistry combined with tritiated thymidine autoradiography at appropriate anatomical levels throughout the anteroposterior (A/P) axes of the substantia nigra pars compacta (SNc) and the ventral tegmental area (VTA). The wild-type (+/+) and homozygous weaver (wv/wv) mice used here were the offspring of pregnant dams injected with the radioactive precursor when the mesencephalic neurons were being produced (gestational days 11-15). Data reveal that, at postnatal day 90, depletion of TH-stained cells in the wv/wv presented an A/P pattern of increasing severity and, therefore, the DA cells located in posterior parts of the SNc or the VTA appear to be more vulnerable than the settled anterior neurons. When the time of neuron origin is inferred for each level of these cell groups, it is found that the neurogenesis span is similar for both experimental groups, although significant deficits in the frequency of wv/wv late-generated neurons were observed in any level considered. On the other hand, it has been found that TH-positive neurons were settled along the extent of the SNc and the VTA following precise and differential neurogenetic gradients. Thus, the acute rostrocaudal increase in the proportion of late-generated neurons detected in both+/+DA-cell groups is disturbed in the weaver homozygotes due to the indicated A/P depletion.     

Serotonin content is elevated in the dopamine deficient striatum of the weaver mutant mouse

In the present study, we measured the striatal serotonin content of weaver and control mice at different ages. Overall, weaver mutant mice exhibited 50% more striatal serotonin than controls. Neither a rostrocaudal gradient nor an age effect was found for either genotype. An analysis of serotonin content across the dorsoventral extent of the striatum revealed that in the dorsal striatum of the weaver, serotonin content was increased 200%, and in the ventral striatum, the increase amounted to 50% relative to control mice. Serotonin immunocytochemistry also revealed an increase in the dorsal striata of weaver mice. The major increase in striatal serotonin content seen in the weaver striatum occurs in the same region that exhibits the severest dopamine depletion. This observation is consistent with the notion that the increase in serotonin levels may be secondary to the decrease in dopamine content and may play an adaptive or compensatory role.     

The role of radiology in assessing patients with pathological obesity submitted to modified Mason's vertical gastroplasty. A study of 322 cases

PURPOSE: Mason's vertical banded gastroplasty (VBG) is one the most popular surgical techniques for the treatment of morbid obesity because it is effective and easy to perform and presents a low incidence of long-term complications. We report our personal results in 322 Mason's VBG patients who were followed-up radiologically. MATERIAL AND METHODS: 322 patients submitted to modified Mason's VBG underwent radiological follow-up, preferably with single contrast, to assess the shape and volume of the pouch and the presence of postoperative complications. The patients were 272 women and 50 men whose average weight was 124 kg (range: 78 to 218 kg). The women's average age was 37 years (range: 17 to 69) and the men's 36 (range: 19 to 64). We performed a double contrast examination, adapting the dosage of effervescent powders to the gastric pouch capacity, only in particular cases where a more detailed study of pouch surface was required. The examinations were performed at 1 month and 12 months postoperatively to evaluate the pouch shape and volume, in order to correlate surgical results with weight loss. Premature or unscheduled examinations were necessary only in some cases due to suspected complications or unsatisfactory weight loss. First we perform right anterior oblique projections with the patient standing, with a direct preliminary study of the epigastric region to locate the two metal clips. The patient is given barium in small swallows because large amounts might obscure the pouch by filling the fundus of the excluded stomach. Then we take left anterior oblique views to depict the neopylorus and the staple lines, and left posterior oblique projections in lateral and supine recumbency. RESULTS: We observed early postoperative complications such as pseudopylorus edema (8 patients) and intragastric hemorrhage (1 patient), and late complications such as pseudopylorus adherence to the gallbladder bed (1 patient), pseudodiverticular extroversion (1 patient), and axial enlargement (4 patients) of the pouch. The only two cases of staple-line dehiscence were both identified radiographically. In 305 patients with satisfactory weight loss no complications were observed with a pouch size of 45-70 mL (at 1 month) and 58-70 mL (at 12 months). DISCUSSION AND CONCLUSIONS: Upper gastrointestinal radiological studies permit to detect both early and late postoperative complications in Mason's VBG patients. They also provide data on the neostomach and permit to correlate the pouch volume with weight loss.