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Biomedical subjects

J D Baker

Publications and source records attributed to J D Baker.

At least 127 records · Page 7Linked to original sources
PubMed1983

Congenital arteriovenous malformations. The role of transcatheter arterial embolization.

We treated 11 patients with congenital arteriovenous malformations (AVMs) with staged transcatheter arterial embolization of their lesions. In nine patients, the AVM involved an extremity. One patient had multiple pulmonary AVMs, another an AVM of the pancreas. Embolization was performed using polyvinyl alcohol sponge (Ivalon) particles and Gianturco-Wallace colls. Nine patients had a systemic response to embolization, characterized by pain, fever, leukocytosis, and elevated enzyme levels. Complications (three major, two minor) developed in five patients. A total of 28 staged embolizations were performed, with follow-up to 36 months. We found transcatheter embolization a useful palliative therapy in treating congenital AVMs. It should be considered as a therapeutic alternative for patients with unresectable AVMs, those for whom amputation would be required, and those who are otherwise poor surgical candidates.

Adolescent↗
PubMed1983

Risk of renal failure after major angiography.

In 400 patients who underwent major aortography, acute renal dysfunction (ARD) occurred in 11.3%. Of the group with normal renal function before the procedure, 8.2% had ARD and 0.8% required dialysis. Patients with prior abnormal renal function had a 41.7% incidence of ARD, and 8.3% required dialysis as a result of angiography. Vigorous intravenous hydration was used in all patients but did not completely prevent renal problems. Two risk factors not previously emphasized were the injection site (higher risk with abdominal aortic studies) and presence of congestive heart failure requiring treatment with digoxin. Other notable risk factors included contrast load and age. These results emphasized that even with modern contrast agents and application of current concepts of treatment, there remains a risk of renal injury with major angiography.

Acute Kidney Injury↗
PubMed1983

Cause and noninvasive detection of restenosis after carotid endarterectomy.

The incidence of significant restenosis after carotid endarterectomy was studied with ocular pneumoplethysmography. Of 105 operations, symptomatic restenosis occurred in 4.8 percent and asymptomatic restenosis in 6.6 percent. No preoperative factors were identified to be associated with subsequent recurrence. However, technical problems with the end-point of the endarterectomy were associated with restenosis. Half of the restenoses occurred in the first 6 months of operation. The results focus on the need for special attention to the technical management of end-point problems and the need for early noninvasive follow-up to detect a substantial proportion of early restenoses.

Arterial Occlusive Diseases↗
PubMed1983

Fate of aortic graft removal.

Reoperation to remove an aortic graft was performed in 18 patients. The need for removal was infection in the majority. A changing flora was seen in aortic graft infection with gram-negative organisms predominating. Despite a standardized approach with total graft removal, aortic closure, and extraanatomic reconstruction, amputation and mortality rates remain unacceptably high. A new approach to this problem is needed, and further trials with autogenous reconstruction appear warranted.

Aged↗
PubMed1983

Aortic saddle embolus. A twenty-year experience.

Clinical experience with aortic saddle embolus (ASE) is not extensive due to the relative infrequent lodging of emboli at the aortic bifurcation. During the period 1962-1982, 26 patients (mean age, 56 years) were treated at the UCLA Medical Center for ASE and followed from 2 to 158 months (mean, 45 months). These cases were reviewed in order to identify features of diagnosis, anticoagulation, and operation which impact on results. All 26 patients presented with bilateral lower extremity ischemia with or without extension of clot to the iliac bifurcation. Ninety-six per cent of emboli were of cardiac origin and one-third occurred in patients who had previous symptoms of chronic lower extremity ischemia. Rest pain and motor/sensory deficits were main complaints in 92% of the patients, but did not become manifest until more than 6 hours, unlike more distal emboli which have an earlier presentation. Preoperative angiography, even in the patient with a history of claudication, has a small role in planning the surgical approach to patients with ASE and, although performed in 11 patients, it influenced operation in only two. Operation within the "golden period" of 6 hours after embolization did not significantly influence outcome after ASE, since 20 patients were operated on more than 6 hours after embolization, with results similar to six patients who were operated on less than 6 hours after embolization. Early high-dose heparinization, used in all patients and maintained for a mean of 12 days, may have contributed to this effect. In 22 patients (85%) Forgarty catheter extraction via bilateral groin approaches was used with a mortality of 14%; only one death was directly attributed to the catheter embolectomy. In 15% of patients, a direct approach on the aorta was selected with a zero mortality rate. Postoperative functional result was excellent with an amputation rate of only 2% (one limb). Re-embolization occurred in seven patients (27%) after discharge, five of whom had not been maintained on Coumadin and two who were not anticoagulated adequately. The authors conclude that the keys to successful treatment of ASE include high dose heparin which is maintained through the perioperative period, embolectomy without preoperative angiography, and maintenance of long-term oral anticoagulation.

Adult↗
PubMed1982

Natural history of nonstenotic, asymptomatic ulcerative lesions of the carotid artery. A further analysis.

The natural history of 153 asymptomatic, nonstenotic ulcerative lesions of the carotid bifurcation in 141 patients was reviewed. A technique for quantitatively defining small (A), large (B), and compound (C) ulcers was developed. During the course of study, extending up to ten years, 3% of patients with A ulcers, 21% with B ulcers, and 19% with C ulcers had hemispheric strokes without antecedent transient ischemic attacks (TIAs), on the side appropriate to the lesion. The interval annual stroke rate was 4.5% for B ulcers and 7.5% for C ulcers. Because these interval stroke rates are comparable to the 6% annual stroke rate occurring in patients with TIAs, a well-accepted indication for operation, we recommend prophylactic operation for these lesions in good surgical candidates, to be performed by surgeons who have demonstrably low operative stroke rates.

Actuarial Analysis↗
PubMed1982

Evaluation of extracranial cerebrovascular disease in the hypertensive patient with ocular pneumoplethysmography at 500 mm Hg.

OPG-300 is a reliable noninvasive method of detecting hemodynamically significant stenoses of the internal carotid circulation. An important limitation of the method is that patients with systemic blood pressure greater than 160 mm Hg cannot be studied; in our laboratory this represented 55 percent of the patients referred for testing. The addition of the 500 mm Hg vacuum modification now allows us to reliably test 95 percent of patients referred to our laboratory for evaluation of the extracranial cerebrovascular circulation.

Blood Pressure↗
PubMed1982

Diagnosis of carotid stenosis by bruit spectral analysis.

Bruit spectral analysis provides an improved noninvasive method of quantifying the severity of carotid stenosis, and the method of Lees estimates the residual luminal diameter. Although the analysis required is complex, the test can be easily performed using the Spectraview, a microcomputer-based device which records and processes the sound information. The present study evaluated 44 cervical bruits in patients and found that in 84 percent of the vessels the estimated luminal size was within 1 mm of the angiographic lumen. Although substantial experience is required to obtain the maximum diagnostic accuracy, work with the technique during 18 months indicates that is provides more information from arterial bruits thn traditional phonoangiography.

Aged↗
PubMed1982

Femoropopliteal tibial bypass: what price failure?

The consequences of failure in 235 femoropopliteal and femorotibial operations are reviewed and compared with the benefits of success so that an accurate perspective of risk-benefit analysis can be achieved. In 72 operations performed for claudication, 10 grafts thrombosed early. The cost included nine reoperations to achieve eight patent grafts and a 12 day average increase in hospital stay. There were no deaths. The benefit obtained was 70 of 72 (97 percent) asymptomatic limbs. In 163 grafts placed for limb salvage, there were 58 initial thromboses. Reoperation in 28 produced an additional 14 patent grafts. The cost of thrombosis was an increase in mortality from 5.6 to 10.7 percent, a 12 day average increase in hospital stay, and raising of preoperative predicted amputation level from below to above the knee in 11 patients with thrombosed grafts whose distal anastomoses were below the knee. This contrasted with a 73 percent limb salvage rate in 104 patients whose preoperative predicted amputation level was below the knee, and a 54 percent limb salvage and a 12 percent lowering of amputation level in 39 patients whose preoperative amputation level was above the knee. Of patients with patent grafts, 89 percent achieved limb salvage. We conclude that the benefits of success in attempted vascular reconstruction for threatened limb loss far outweigh the risks of failure and that the combined results were far superior to the expected outcome in comparable patients undergoing primary amputation.

Amputation, Surgical↗
PubMed1981

Carotid artery stenosis - hemodynamic significance and clinical course.

Two hundred fifteen patients with a history of either stroke, transient ischemic attack (TIA), or asymptomatic carotid bruit underwent noninvasive carotid artery testing using oculopneumoplethysmography. Of patients with hemodynamically significant stenosis, 51 (40.8%) underwent endarterectomy, and 74 (59.2%) were treated nonoperatively. The incidence of stroke in the nonoperated group was 12/74 (16.2%) compared with only 1/51 (1.9%) in the operated group. Similarly, recurrent TIA occurred in 29/74 (39.2%) of the nonoperated group vs 9/51 (17.6%) of the operated. In nonhemodynamically significant carotid stenosis, the risk of cerebrovascular death and stroke was exceedingly low: 2/90 (2.2%). Patients with hemodynamically significant stenosis treated nonoperatively have a greater risk of cerebrovascular death, stroke, and TIA than patients treated with carotid endarterectomy.

Arterial Occlusive Diseases↗
PubMed1981

Evaluation of internal carotid stenosis with the Chronopulse, an automated ocular pulse arrival time recorder.

The diagnostic value of ocular pulse time measurement with the Chronopulse was evaluated in 67 patients who had carotid arteriography. The diagnostic accuracy of 85.5 percent was comparable to that obtained by two other groups using a different timing device. Identification of bilateral stenosis was the major problem encountered and resulted from measuring the external carotid circulation at the ear. Ocular pneumoplethysmography performed in the same patients yielded a higher diagnostic accuracy than the pulse timing, and combining the two did not enhance the results. Therefore, we recommend that the Chronopulse not be used as part of the routine ocular pneumoplethysmographic examination but that it be reserved for selective application.

Blood Pressure↗
PubMed1981

Variability of Doppler ankle pressures with arterial occlusive disease: an evaluation of ankle index and brachial-ankle pressure gradient.

The variability of Doppler ankle pressures was studied in 35 men with clinically stable claudication. An average of 6.8 measurements was obtained from each man. The mean range of ankle index was 0.18 with a mean standard deviation of 0.07. The brachial-ankle pressure gradient had a wider spread, with a mean range of 38 mm Hg and a standard deviation of 13.9. The amount of variation in a given patient was unrelated to mean blood pressure or mean ankle index. The results of this study show that the ankle index must change at least 0.15 before it can be considered significant. Based on the variability found, we recommend that multiple baseline determinations be obtained on patients who are to be followed longitudinally.

Ankle↗
PubMed1980

Adenoid cystic carcinoma of the lacrimal gland in a child.

An unusual case of adenoid cystic carcinoma of the lacrimal gland occurred in an 11-year-old child. Clinical, echographic, and histopathologic characteristics, as well as the management of this usually fatal disease, are discussed. The subtle signs and symptoms of this tumor were noted at the age of 9 years. A review of the literature reveals this to be the youngest patient in whom this tumor has been reported.

Carcinoma, Adenoid Cystic↗
PubMed1980

Early-onset accommodative esotropia.

Twenty-one patients had esotropia diagnosed before age 12 months. In all of these patients esotropia was eliminated, at least initially, by antiaccommodative therapy consisting of either full hypermetropic spectacles or miotics, or both. Clinical findings evaluated in these patients were comparable to similar clinical factors studied in a larger series of patients with accommodative esotropia, most with onset after 12 months of age. In approximately 50% of these patients early-onset accommodative esotropia deteriorated to a nonaccommodative esotropia that required surgery despite aggressive antiaccommodative therapy. All but one of the surgically treated patients continued to need hypermetropia spectacles postoperatively to maintain alignment.

Accommodation, Ocular↗
PubMed1980

Ocular pneumoplethysmography in the evaluation of carotid stenosis.

Ocular pneumoplethysmography is a noninvasive technique for detecting carotid stenosis by measurement of ophthalmic artery pressure. The results of the test were studied in 227 patients who underwent biplane angiography. The overall accuracy was 93% in the correct identification of hemodynamically significant stenosis (defined as a 60% or greater decrease in luminal diameter). The good result of this single test makes it our choice of noninvasive methods for both screening and follow-up study of carotid occlusive disease.

Carotid Arteries↗
PubMed1979

Monofixational intermittent exotropia.

The surgical correction of intermittent exotropia occasionally results in a monofixational sensory pattern. Stereopsis as a measure of bifixation was studied preoperatively and postoperatively in 39 cases of intermittent exotropia. Of 26 patients with bifixation, 25 remained so after surgery. Of 13 patients with monofixation, 11 remained unchanged by surgery, one improved, and one lost all binocularity. The presence of preoperative monofixational intermittent exotropia, to explain a monofixation result from intermittent exotropia surgery, is proposed.

Adolescent↗
PubMed1979

Late results of extra-anatomic bypass.

Clinical progress and results were reviewed in 100 consecutive patients who underwent extra-anatomic bypass procedures for brachiocephalic and aortoiliac occlusive disease during the past 15 years. Of 113 procedures in this group, extra-anatomic bypass of the brachiocephalic vessels, axillo-femoral bypass, and femorofemoral bypass were performed. Although these procedures were performed in high-risk patients to avoid intrathoracic and intra-abdominal reconstruction or to circumvent undesirable anatomic areas, a low operative mortality was achieved. Symptomatic improvement, augmented Doppler ankle pressure index, and high limb-salvage rate were noted. Life-table analysis has confirmed prolonged five-year graft patency. The suspected high-risk characteristic in this group was corroborated by high progressive mortality observed particularly after axillo-femoral bypass and was due primarily to the severity of associated diseases. Analysis of the late results of extraanatomic bypass confirms the safety and effectiveness of this procedure in poor-risk patients.

Adult↗