Distal lateral ventricular atrium: reevaluation of normal range.

PURPOSE: To reassess the mean size of the lateral cerebral ventricular atrium in the fetus. MATERIALS AND METHODS: Measurements were obtained from axial ultrasound (US) images of 500 fetuses by using the standard criteria, and they were reviewed for consistency. Eleven fetuses had ventricular atrial measurements of 10 mm or more, and they were also followed up. Postnatal evaluation consisted of US examinations of the head in three patients and clinical examination of all 11 patients. RESULTS: The mean size of the ventricular atrium was 6.6 mm with a standard deviation (SD) of 1.4 mm. However, the mean plus 2.5 SD would yield an upper normal limit of 10.1 mm. Findings at the postnatal examinations of the 11 fetuses with isolated lateral ventriculomegaly (three with measurements of 13 mm or less and eight with measurements at 10 mm) were normal. CONCLUSION: Use of 10 mm (mean from this study plus 2.5 SD) as the upper limit of normal for the ventricular atrial measurement should be continued. Measurements of 10 mm or above should prompt a careful search for associated fetal abnormalities and consideration of amniocentesis.

Proximal fetal cerebral ventricle: description of US technique and initial results.

PURPOSE: To establish adequacy and ease of visualization of the proximal ventricle, normal range of measurements of the proximal ventricle, and distance of the proximal choroid plexus from the lateral ventricular wall. MATERIALS AND METHODS: With use of an angled technique, ultrasound (US) evaluation of the proximal fetal ventricle was attempted in 439 fetuses during routine obstetric US examination. Ease of examination, additional time required, mean measurements, and standard deviation (SD) were calculated. RESULTS: Visualization and measurement of the proximal ventricle were performed without difficulty in 77% of cases and with difficulty in 19%, and were impossible in 4%. Average additional time required was 4.2 minutes. The upper limit of normal for the midportion of the proximal ventricle was 8 mm (mean + 2.5 SD). In no normal pregnancy was the proximal ventricle separated from the choroid plexus by greater than 3 mm. CONCLUSION: Visualization and measurement of the proximal fetal cerebral ventricle can be performed during routine obstetric US examination in little additional time and can be used to detect abnormalities that might otherwise be overlooked because of fetal position.

Refinement of a technique for thermocholecystectomy in an animal model.

RATIONALE AND OBJECTIVES: A modification of a thermal ablation system was tested for improved cystic duct occlusion and gallbladder mucosa ablation in an animal model. METHODS: Fourteen domestic swine were included in group 1 with thermal treatment of the cystic duct to 75 degrees C for 15 minutes, followed by heating of the gallbladder lumen with a catheter/heating device to 54 degrees C for 30 minutes. One swine served as a control (group 2). A ligature was placed around the cystic duct without thermal treatment of the cystic duct and with the catheter/heating device placed into the gallbladder for 30 minutes without thermal treatment. All animals were killed after 3 weeks with histologic examination of the gallbladder, cystic duct, and surrounding organs. RESULTS: In group 1, technical failure due to catheter clogging occurred in the first three animals, which were killed immediately. Eleven animals were treated with a redesigned catheter system. Three weeks after treatment, 10 of the 11 animals had complete cystic duct occlusion and complete obliteration of the cystic duct mucosa. One of the 11 animals experienced partial cystic duct ablation. Nine of the 11 treated animals experienced complete mucosal ablation of the gallbladder. Five of the 11 animals had no residual lumen, whereas 6 of the 11 had a luminal volume that averaged 4 mL compared to 35 mL before treatment. In group 2, the control subject had a gallbladder volume of 50 mL and normal gallbladder and cystic duct mucosa. CONCLUSIONS: This study demonstrates improvement in both cystic duct occlusion and gallbladder mucosa ablation with standardization of the technique for thermocholecystectomy in an animal model. However, a better system is required to promote complete obliteration of the gallbladder lumen.

Percutaneous cholecystostomy for suspected acute cholecystitis in the hospitalized patient.

PURPOSE: The authors evaluated the outcome of 49 hospitalized patients with sepsis and possible acute cholecystitis in whom emergency percutaneous cholecystostomy was attempted on 50 occasions. PATIENTS AND METHODS: All cholecystostomy procedures were performed with ultrasound (US) guidance by using either the trocar (n = 35) or the Seldinger (n = 15) technique. Forty of the 50 cholecystostomies (80%) were attempted at the patients' bedside, and 49 of the 50 catheters (98%) were placed successfully. RESULTS: Twenty-five of these patients eventually died of other causes (51%), but there was clinical improvement in 31 of the 49 patients (63%) based on a 72-hour decrease of temperature to less than 37.3 degrees C, normalization of white blood cell count, and/or resolution of abdominal pain. US findings were correlated with clinical response. Clinical improvement occurred most frequently after cholecystostomy in patients with either a distended gallbladder (74%), pericholecystic fluid (80%), or gallstones (92%). Forty-three of the 49 patients underwent cholecystostomy alone (88%), and six required further procedures (12%). There were six complications (12%) including catheter dislodgment (n = 3), hematoma (n = 1), and severe pain (n = 2). No deaths were directly attributed to percutaneous cholecystostomy. CONCLUSION: Percutaneous cholecystostomy performed in septic hospitalized patients is a low-risk procedure that may be helpful in the treatment of some patients with suspected acute cholecystitis.

Hepatic ablation with use of radio-frequency electrocautery in the animal model.

The potential of percutaneous radio-frequency (RF) electrocautery hepatic ablation was evaluated in the animal model. RF hepatic ablation was performed under ultrasound (US) guidance in the liver of 10 swine with use of a specifically designed needle. The needle was placed through the liver capsule, and ablation was performed after isolating the liver at laparotomy. Animals were killed immediately (n = 4), at 1 week (n = 1), 2 weeks (n = 3), or at 5 weeks (n = 2). The US findings were correlated with the pathologic results in the animal livers. RF hepatic ablation was successfully performed in the animal model without complications. Lesions in the animal livers were typically 1 x 2 cm, which initially appeared highly echogenic on US scans. These images corresponded to an area of hepatic necrosis. The lesions became less echogenic shortly after initial treatment but could still be visualized with US at 5 weeks. At histologic study at 5 weeks, the treated livers showed central debris, a larger area of necrotic liver, and a zone of granulation tissue surrounded by a fibrotic capsule. No complications were encountered. RF hepatic ablation shows future promise in treatment of hepatic neoplasms.