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Biomedical subjects

S E Mitchell

Publications and source records attributed to S E Mitchell.

At least 91 records · Page 5Linked to original sources
PubMed1984

A comparison of computed tomography and sonography in choledocholithiasis.

A comparison was made of sonography and computed tomography (CT) for the diagnosis of choledocholithiasis. Sonography correctly diagnosed nine of 49 patients with choledocholithiasis for a sensitivity rate of 18%. The accuracy rate for sonography was 19%; there were five false-positive examinations. CT correctly identified common duct stones in 26 of 30 patients for a sensitivity rate of 87%. The accuracy rate was 84%; there was one false positive. Sonography is limited in its ability to image calculi in the distal common bile duct. CT is effective for imaging common duct stones and is superior to sonography for diagnosing this cause of biliary obstruction.

Diagnosis, Differential↗
PubMed1984

Tailored approach for evaluation of peripheral vascular disease: intravenous digital subtraction angiography.

A tailored approach for evaluating patients with peripheral vascular disease has been developed using intravenous digital subtraction angiography (IV DSA). This approach includes a history, physical examination, and correlation with Doppler pressure measurements to predict the location of the dominant lesion. In 60 patients, two views of the aortoiliac segment plus three or four views of the femoral and runoff circulation in the most symptomatic leg were obtained. Of the 60 patients, 36% had percutaneous transluminal angioplasty as a primary form of therapy, 32% were treated surgically, and 32% were followed clinically. Only 10% of these patients required further evaluation by conventional angiography. By omitting inpatient arteriography, considerable financial savings and increased patient comfort result.

Aortic Diseases↗
PubMed1983

Pulmonary arteriovenous malformations. Physiologic observations and results of therapeutic balloon embolization.

Pulmonary arteriovenous malformations can result in severe hypoxemia and dyspnea. We measured pulmonary function, arterial blood gases, and hemodynamics in 10 patients with such malformations. Pulmonary-function tests were normal, but hypoxemia was associated with chronic hyperventilation at rest (mean, 12 liters per minute; mean carbon dioxide tension, 28 mm Hg). With exercise, ventilation increased more than expected for the level of carbon dioxide production. Balloon embolization of 58 of the 71 visible vascular malformations in the 10 patients resulted in an increase in arterial oxygen tension (43 vs. 64 mm Hg; P less than 0.001) and hemoglobin saturation (79 vs. 92 per cent; P less than 0.001). Nine patients had improved exercise tolerance. Forty-eight to 72 hours after correction of the hypoxemia, resting ventilation had decreased but was still above normal (mean, 9.3 liters per minutes; mean carbon dioxide tension, 29 mm Hg). We conclude that ventilatory responses in these patients are similar to those of people from sea-level areas who are acclimated to high altitudes and that dyspnea is due to inappropriately high levels of ventilation for a given workload under hypoxic conditions.

Adult↗
PubMed1983

Intraarterial digital subtraction angiography: a comparative view.

Intraarterial digital subtraction angiography (IA DSA) was performed in 122 patients undergoing a variety of diagnostic and interventional angiographic procedures. Owing to the increased contrast resolution of DSA, diluted contrast material in concentrations of from 12-19% could be employed, thereby significantly reducing contrast material doses compared to doses used with conventional film-screen angiography or intravenous DSA. Patient discomfort was convincingly reduced due to the injection of dilute contrast material. Subtracted digital images could be viewed immediately on a cathode ray tube (CRT) resulting in faster procedures with less catheter time. Savings in film costs relative to conventional angiography were also achieved.

Angiography↗
PubMed1983

Percutaneous transluminal angioplasty of aortic graft stenoses.

Postoperative aortic graft anastomotic stenoses at nine sites in eight patients were successfully treated with percutaneous transluminal angioplasty. There was a decrease in peak systolic pressure gradient in all eight patients, and in seven of the eight patients symptoms of claudication disappeared immediately after angioplasty. Four of the eight patients remained asymptomatic at follow-up. Ankle/arm indices were obtained before and after angioplasty in five patients, with postangioplasty improvement in all five.

Aged↗
PubMed1983

Treatment of restenosis of coarctation by percutaneous transluminal angioplasty.

Percutaneous transluminal angioplasty (PTA) was used successfully to treat coarctation restenosis in seven patients. The patients were 10 months to 17 years old at the time of the angioplasty, and the initial coarctation repair had been performed 10 months to 16 1/2 years previously. PTA reduced the systolic pressure gradient across the coarctation from a mean of 58 mm Hg before the procedure to a mean of 13 mm Hg immediately after PTA. Follow-up has been from 1 to 14 months and indicates that the decrease in the systolic pressure gradient is persistent.

Adolescent↗
PubMed1983

Angioarchitecture of pulmonary arteriovenous malformations: an important consideration before embolotherapy.

Seventeen patients with 91 pulmonary arteriovenous malformations were evaluated by superselective angiography. Seventy-two (79%) of the malformations consisted of a simple type characterized by a single feeding artery draining into a bulbous, nonseptated aneurysmal communication with a single draining vein. The other 19 (21%) were complex, consisting of two or more pulmonary artery branches communicating with a bulbous septated aneurysmal part with two or more draining veins. Two patients had diffuse pulmonary arteriovenous malformations confined to multiple lobes of the lung. Balloon embolotherapy was effective in permanently obliterating the malformations in 14 patients treated. Therapy provided a sustained rise in arterial PO2 in the sitting position from a mean value of 44 mm Hg before occlusion to 65 mm Hg after occlusion. In three patients the process was too diffuse and/or the malformations too large for therapy to be effective. Complex pulmonary arteriovenous malformations required occlusion of all feeding arteries. Balloon embolotherapy provided an effective treatment for pulmonary arteriovenous malformations regardless of anatomic type.

Adolescent↗
PubMed1982

The hypoechoic caudate lobe: an ultrasonic pseudolesion.

The hypoechoic caudate lobe may occur as a normal variant because of acoustic shadowing in patients with more than the usual amounts of fat or fibrous tissue along the fissure of the ligamentum venosum. The use of a lower frequency transducer may cause the shadowing to decrease or disappear and the caudate lobe to appear more normal. The problem may also be resolved by angling the static scanner from the side or by using a real-time scanner. If pathologic lesions are still suspected, correlation with computed tomography is recommended.

Aged↗
PubMed1981

CT of malignant pleural mesothelioma.

Malignant pleural mesothelioma is a rare tumor. Although the chest film findings of pleural mesothelioma are well described, there are few descriptions of the findings of computed tomography (CT). This report describes the CT findings in five cases of pleural mesothelioma. In each case the CT showed an extensive, irregular, pleural-based mass surrounding the lung, spreading into the fissures, and extending into the mediastinum. In two cases there was also extension into the contralateral chest, and in one case each there was extension into the abdomen and chest wall. In each case the chest radiographs underestimated the extent of disease, when compared to CT. When an irregular, pleural-based mass involving most of the hemithorax is identified on CT, the diagnosis of mesothelioma can be suggested and at the same time the extent of the tumor may be evaluated. This is important because the diagnosis of mesothelioma is difficult and because treatment and prognosis may depend on the extent of the disease.

Aged↗
PubMed1981

Percutaneous catheter biliary decompression.

Percutaneous catheter biliary decompression was performed in 42 patients with obstructive jaundice. Internal drainage was accomplished in 27 patients (64.3%), and external drainage in 15 patients (35.7%). Serum bilirubin levels decreased at a mean rate of 1.4 mg/dl/day. Tissue diagnosis was obtained by percutaneous aspiration biopsy in nine patients (21.4%). Complications occurred in 10 patients (23.8%): septic shock, two; bilious pleural effusion, one; hepatic subcapsular hematoma, one; sepsis, six. There was one death related to the procedure. The catheter management problems encountered included pain, catheter dislodgement or migration, lumen occlusion, and external bile leakage.

Aged↗
PubMed1979

Complications of central venous catheterization.

The complications of central venous catheterization are discussed in a review of experience and of the literature. The anatomy surrounding the subclavian and internal jugular veins is described. Indications and contraindications of catheterization are reported. Common and unusual complications are discussed and illustrated. Laceration of pleura, subclavian artery puncture, hematoma, catheter malposition, fragment embolization, air embolism, venous thrombosis, and infection are included. The radiologist is responsible for recognizing immediate, as well as delayed, complications of central venous catheterization.

Blood Vessels↗
PubMedDate not supplied

Percutaneous transluminal atherectomy of the superficial femoral and popliteal arteries: long-term results in 48 patients.

PURPOSE: Evaluate retrospectively the long-term primary patency of directional atherectomy (DA) in the femoropopliteal arteries. MATERIALS AND METHODS: DA was used alone in 59 patients (47%) or in combination with predilatation to allow passage of the device (43%) or after thrombolysis (10%) to treat 127 (93%) excentric atherosclerotic stenoses and nine (7%) occlusions of the femoropopliteal arteries. Forty-eight patients were followed by telephone interview, scheduled outpatient visits, color-flow Doppler evaluation, and angiography for 1-36 months (mean 16.9 months). RESULTS: Technical success (reduction of the stenosis or occlusion to less than 30% luminal diameter) was achieved in 110 lesions (80.3%) during 48 procedures in 37 patients. Mean luminal diameter was increased 54% with a concomitant increase in mean ankle/brachial indices of 0.33. According to Kaplan-Meier survival curves, patency at 12 and 24 months was 88% and 75%, respectively. When patients who retained patency but developed restenosis were excluded, the probability of patency at 12, 24, and 36 months was 76%, 58%, and 32%, respectively. Major and minor complications occurred in 15 (21.4%) procedures each for a total complication rate of 42.8%. CONCLUSION: Based on our results, DA is an effective method for percutaneous treatment of atherosclerotic disease involving the femoropopliteal arteries. It has similar patency but a relatively high complication rate compared with PTA.

Actuarial Analysis↗
PubMedDate not supplied

Atrial septostomy: stationary angioplasty balloon technique--experimental work and preliminary clinical applications.

A new approach to creating an interatrial communication using a stationary fixed-diameter angioplasty balloon is presented. Stationary balloon septostomy was used to create an atrial communication in 19 young swine using a transseptal technique through a closed atrial septum, and in 18 newborn lambs through a patent foramen ovale. In animals with an intact septum, there was persistent patency of the atrial communication using balloons larger than 12 mm in diameter. The average diameter of the atrial communication was 96% of the expanded diameter of the angioplasty balloon. For newborn lambs with a patent foramen, a smooth oval atrial communication was noted by 4 weeks, and there was persistent patency of the opening using balloons larger than 15 mm in diameter. The average diameter of the opening was 81% of the diameter of the angioplasty balloon used. The new procedure was used successfully in five patients. All five showed resolution of the clinical symptomology. In conclusion, stationary angioplasty balloon atrial septostomy has been effective in producing interatrial communications, which remained patent for 4-14 weeks, in animals with intact septum, as well as in those with a patent foramen ovale.

Angioplasty, Balloon↗