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Biomedical subjects

D Waldman

Publications and source records attributed to D Waldman.

15 recordsLinked to original sources
PubMed2000

Mechanical versus chemical thrombolysis: an in vitro differentiation of thrombolytic mechanisms.

PURPOSE: To assess differing mechanisms of thrombolysis determining time to reperfusion, completeness of thrombus dissolution, and embolic potential. MATERIALS AND METHODS: An in vitro perfusion model designed to mimic arterial flow conditions was created. Bifurcated limbs allowed continuous flow through one channel and the placement of radiolabeled (iodine-125) thrombus housed in a 5-cm segment of polytetrafluoroethylene graft in the other. The three experimental groups consisted of a standard continuous urokinase infusion, a pulsed pressurized injection of saline, and a similar injection with urokinase. A continuous infusion of 5% dextrose served as a control group. Time to reflow (as assessed with ultrasonic flow monitoring), completeness of thrombus dissolution (I-125 liberated into solution), and the number and size of embolic particles produced (detected by a series of graduated filter sizes) were analyzed. RESULTS: Time to reflow was significantly faster for both groups when pressurized injections were used (P < .001). There was no reflow in the control arm at 90 minutes. Completeness of thrombus dissolution was higher when a continuous infusion of urokinase was used in comparison to either of the power injection groups or the control (P < .05). The amount of embolic debris produced was significantly lower with a continuous infusion of urokinase compared with either of the power lysis groups (P < .05), but significantly greater than the control arm (P < .001). The size of the embolic particles in the power pulsed lysis groups was significantly decreased by the addition of urokinase (P < .05). CONCLUSIONS: Reflow is more rapidly established by the use of mechanical means. However, a less complete dissolution of thrombus in conjunction with a greater amount of embolic debris is achieved with this approach. The size of the embolic particles produced is reduced by the addition of a thrombolytic agent.

Blood Vessel Prosthesis↗
PubMed2000

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Journal Article↗
PubMed2000

Claviculectomy for subclavian venous repair: long-term functional results.

OBJECTIVES: The purpose of this study was to determine the long-term functional results after medial claviculectomy and venous patch angioplasty or bypass grafting using internal jugular vein after incomplete thrombolysis of effort thrombosis of the subclavian vein. METHODS: The records of 11 patients with effort thrombosis who were treated over the past 9 years were reviewed. Patients have been followed up between 3 and 9 years at 6-month intervals with duplex imaging and contrast venography when indicated and have had an orthopedic evaluation of their shoulder function. RESULTS: All reconstructed veins are patent, and only one patient complains of any arm swelling after prolonged usage. This patient is one of three with postphlebitic changes at the site of repair and has similar findings in her basilic vein. All patients have returned to their prethrombosis vocation without limitation. Four of the 11 patients have jobs requiring heavy physical labor. No patient describes any limitations of shoulder function, but one man who works as a diesel mechanic complains of shoulder aching with overuse with repetitive pulling. Three patients describe upper extremity paresthesias when lying on the operated side. Two patients (one man and one woman) are bothered by the large scar and indentation at the site of the incision. Every patient considers the overall result completely successful from a functional standpoint. CONCLUSIONS: Early subclavian venous repair performed through a medial claviculectomy is a durable operation with excellent long-term functional results. Half of the patients noted minor but significant symptoms, but all are uniformly able to return to normal function.

Adolescent↗
PubMed2000

An endoluminal method of hemorrhage control and repair of ruptured abdominal aortic aneurysms.

PURPOSE: To report our initial experience with endovascular grafting to treat ruptured abdominal aortic aneurysms (AAAs). METHODS: Three consecutive patients with severe comorbid illnesses and symptoms of aneurysm rupture and hemodynamic instability were treated with aortomonoiliac grafts. The Z-stent-based devices were implanted with the assistance of an occlusion balloon placed in the distal descending thoracic aorta. RESULTS: All patients survived the procedure with successfully excluded AAAs. Two patients had relatively short hospital stays (4 and 14 days), while the third required prolonged treatment for pre-existing conditions. All patients required blood transfusions; 2 developed significant coagulopathies. Definitive management was delayed significantly by imaging protocols and graft construction. CONCLUSIONS: Endovascular repair of ruptured aortic aneurysms is feasible. Proximal aortic control is readily attainable with the use of an aortic occlusion balloon placed through the left axillary artery. The absence of a laparotomy, extensive retroperitoneal dissection, and aortic cross-clamping likely contributes to patient survival; however, the delay in operative therapy to obtain adequate imaging and construct an endograft could be a hindrance to the ultimate success of this approach. The concepts of alternative aortic imaging techniques and endograft design, construction, and storage must be addressed.

Aged↗
PubMed1999

Photoplethysmography and calf muscle pump function after subfascial endoscopic perforator ligation.

OBJECTIVE: Subfascial endoscopic perforator surgery (SEPS) results in acceptable healing and recurrence rates. The role of hemodynamic venous testing in this situation, however, is poorly understood and inconsistently used. Our ongoing experience was reviewed to explore how SEPS affects the photoplethysmographic assessment of the leg. METHODS: Preoperative and postoperative venous refill times (VRTs) were measured with photoplethysmography in 30 limbs in 28 patients who underwent SEPS and superficial ablation, when indicated, with complete clearing of the anterolateral surface of the tibia, thus opening the deep posterior compartment from mid calf to close to the malleolus. Postoperative healing and duplex scanning were used to assess clinical and anatomic success, respectively. The VRTs were classified as "interpretable" if the leg emptied or "uninterpretable" if the calf could not empty. The "interpretable" study results were further classified as "normal" if the refill took 20 seconds or more or "abnormal" if less. RESULTS: Before the patients underwent SEPS, six study results (20%) showed inability of the calf to empty and thus were judged uninterpretable. After the patients underwent SEPS, 12 study results (40%) were uninterpretable (NS; P =.09 with the chi(2) test). Of the 24 preoperative interpretable study results, two (8%) were normal, and of the 18 postoperative interpretable study results, seven (39%) were normal (P <.03). With the consideration of only interpretable study results, the mean VRT increased slightly from 12.0 +/- 5.1 seconds (mean +/- standard deviation) to 14.3 +/- 8.1 seconds (NS). Seventeen of 19 ulcers (89%) had healed at a mean follow-up period of 8.6 +/- 4.8 months. CONCLUSION: Although VRT is unpredictably affected by SEPS, the most consistent finding is the inability of the calf to empty, which invalidates the remainder of the test. In addition, most ulcers heal, even with uninterpretable or abnormal postoperative VRTs. This suggests that photoplethysmography is a poor method of assessment of venous reflux after SEPS.

Adult↗
PubMed1999

Treatment of transplant ureteral stenosis with endoureterotomy.

PURPOSE: The safety and efficacy of treating renal transplant ureteral stenosis with the Acucise endoureterotomy catheter are described. MATERIALS AND METHODS: We treated 4 women and 3 men 31 to 63 years old (mean age 45) with Acucise endoureterotomy for distal (6) and proximal (1) ureteral stenosis. Diagnosis was based on increasing serum creatinine and hydronephrosis on ultrasound, and confirmed by antegrade nephrostogram. One patient had recurrence and, therefore, 8 procedures were performed. Mean followup was 13 months (range 7 to 21). RESULTS: Technical success was 100%. One patient had a recurrent stricture and was successfully re-treated. Of the patients 3 had chronic rejection and renal failure, and 4 had stable renal function. All ureters remain patent to date. CONCLUSIONS: Treatment of short ureteral stenosis with Acucise endoureterotomy in a renal transplant is safe and effective. Furthermore, it can be performed in an ambulatory setting with minimal morbidity. This procedure should be considered as the initial approach for distal ureteral stenosis in the transplanted kidney.

Adult↗
PubMed1998

A model for merging vascular surgery and interventional radiology: clinical and economical implications.

BACKGROUND: The traditional separation of vascular surgery and interventional radiology into distinct units is associated with inefficiencies in patient care, practice management, and training. Traditional departmental politics, discrepant clinical backgrounds and philosophies, fear of decreasing remuneration, and basic differences in education, training, and practice have all rendered mergers difficult. METHODS: We have implemented a model that incorporates all the clinical, fiscal, and educational activities of the 2 former entities into a single unit. A 5-physician vascular surgery group, its noninvasive laboratory, and a 3-physician interventional radiology group were unified. The revenue was deposited into a single account from which all the expenses were paid. The net income of the joint unit was apportioned on a predetermined pro rata basis, with scaled percentages for each practitioner. In an effort to separate clinical decision making from economic pressures, the individual physician remuneration was not on the basis of productivity. Clinical volume, gross revenue, and remuneration were compared with the 12-month period that immediately preceded the merger and contrasted to the previous 3-year historical trend (HT). RESULTS: The number of vascular surgical procedures fell after the merger (-9.3%; HT, +4.7%). By contrast, the number of interventional radiology procedures rose (+56.1%; HT, +15.2%), as did the number of noninvasive testing (+9.2%; HT, +3.5%). In concordance with the number of procedures, the gross revenue of vascular surgery fell (-23.7%; HT, +1.1%) and that of interventional radiology rose (+53.5%; HT, +46.0%). The increased efficiencies allowed the total expenses of the 2 units to fall (-13.2%; HT, +7. 5%), and, despite the reduced revenue, the vascular surgeon remuneration was preserved (+0.7%; HT, -3.9%) and the radiology remuneration rose (+22.3%; HT, +8.3%). The merger allowed the vascular surgery fellows to actively participate in 26 interventional cases per month and the interventional radiology fellows to actively participate in 8 open surgical cases per month. CONCLUSION: The merger of vascular surgery and interventional radiology resulted in a decrease in the surgical procedures and revenue, with a corresponding increase in the interventional radiology procedures and revenue. Despite these effects, the physician remuneration increased as a result of the improved efficiencies in practice management and the reduction in expenses. The merger of the 2 units excludes the economic pressures from clinical decision making and appears to be warranted on the basis of the fiscal and educational benefits that are achieved.

Hospital Departments↗
PubMed1998

Endovascular treatment of renal artery thrombosis caused by umbilical artery catheterization.

Renal arterial thrombosis, usually in association with aortic thrombosis, has been reported as a result of prolonged neonatal umbilical artery catheterization. A case of renal artery thrombosis attributable to umbilical artery catheterization, resulting in malignant renovascular hypertension, in a 15-day-old neonate, treated by catheter-directed thrombolysis through the involuting umbilical artery, was studied. Resolution of systemic hypertension and partial return of right renal function followed rapid thrombus dissolution.

Catheterization↗
PubMed1998

Endovascular and open surgical treatment of brachiocephalic arterial disease.

The treatment of occlusive lesions in the innominate, subclavian, and axillary arteries has, until recently, been entirely surgical. Recently, advances in endovascular technologies have provided an alternative means of therapy. The advent of balloon angioplasty has resulted in some turmoil between medical specialties regarding patient selection and acceptable applications. Innovations in imaging, guidewire, catheter, stent, and balloon technology allow one to obtain percutaneous access and perform therapeutic procedures in a relatively safe manner. However, the excellent and time-tested results of surgery remain a standard for developing new procedures. Despite the appeal of less invasive techniques, the morbidity, mortality, and durability of novel treatments must equal or exceed those standards set by surgical procedures. Proponents of the endovascular options must familiarize themselves with advantages and disadvantages of surgical procedures. In a similar manner, surgeons have an obligation to understand the less invasive technologies as well. The clinician must uphold the best interests of the patient as a fundamental factor in the determination of a particular form of therapy. This paradox is well illustrated by consideration of occlusive lesions in the upper extremity.

Angioplasty, Balloon↗
PubMed1997

MRI meningeal enhancement with intracranial hypotension caused by lumbar puncture.

A 12-year-old girl with recent history of pseudotumor cerebri developed severe postural headache due to intracranial hypotension after lumbar puncture. Meningeal enhancement and thickening were demonstrated on magnetic resonance imaging. Repeated imaging 3 months later disclosed no abnormalities. This is the first report of a child with evident meningeal enhancement on magnetic resonance imaging related to lumbar puncture.

Child↗
PubMed1997

Prohibitive failure rate of the total articular replacement arthroplasty at five to ten years.

Five- to 10-year follow-up was obtained on a series of total articular replacement arthroplasties performed at a single university-affiliated teaching hospital. Eighty arthroplasties were performed on 64 patients. Twelve patients (accounting for 14 hip arthroplasties) died. Follow-up was obtained on 62 of the 66 remaining hips (94%). Thirty-five hips had been revised (56%), 32 for acetabular loosening and 3 for femoral loosening, 1 of which led to femoral stem fracture. The average time to revision was 72 months (22 to 132 months). The revision procedures were extensive in terms of operative time, blood loss, and necessity of acetabular bone grafting. Follow-up of the 27 that had not been revised averaged 84 months and revealed 1 hip excellent, 5 good, 1 fair, and 20 poor results. The overall clinical failure rate (revisions plus clinically poor results) was 89% (55/62 hips). These results are far inferior to conventional total hip replacement, and the extent of the revision procedures indicates that this is not a conservative alternative to conventional total hip replacement.

Acetabulum↗
PubMed1978

Treatment of chronic childhood asthma with beclomethasone dipropionate aerosols: II. Effect on pituitary-adrenal function after substitution for oral corticosteroids.

The effects of beclomethasone, dipropionate aerosol (DBA) (400 microgram/day) on clinical course, pulmonary function, and pituitary-adrenal function was studied in 34 steroid-dependent asthmatic children. Asthma severity was assessed by daily symptom and medication scores, peak flow measured three times a day, and weekly spirometry. Pituitary-adrenal function was evaluated by diurnal cortisol levels, cortisol responses to intravenous (IV) corticotropin (ACTH), and steroid responses to IV metyrapone. After 12 weeks of BDA therapy, 30 of 34 patients no longer required prednisone. Mean weekly symptom and medication scores and the number of attacks decreased significantly (P less than .01)). A significant improvement was demonstrated in the patients' peak flow (P less than .01), forced expiratory volume in one second, and maximum midexpiratory flow rates (P less than .01). Thirty of the 34 patients initially had abnormal metyrapone responses, 28 had abnormal diurnal cortisol levels, whereas only 14 had abnormal IV ACTH response tests. Although significant improvement was noted in the mean metyrapone and diurnal cortisol tests, only partial recovery of pituitary-adrenal function was observed in 20 patients, complete recovery in 5, and no change in 9. BDA was found to be therapeutically superior to oral steroids in the group of steroid-dependent asthmatic children and produced no serious adverse effects.

Administration, Oral↗
PubMed1977

Pulmonary vascular disease after systemic-pulmonary arterial shunt operations.

More than 1,100 patients underwent a systemic-pulmonary arterial shunt operation at the Children's Memorial Hospital, Chicago, from 1946 to 1974. Of these patients, 294 were studied to assess the presence of pulmonary vascular disease and the time of its occurrence after surgery. They were selected either because lung tissue was available for histologic grading of pulmonary vascular disease (114 patients) or because hemodynamic studies were performed after the shunt operation (180 patients). The shunts, all patent at the time of the study, ranged in duration from 1 month to 23 years. After a subclavan-pulmonary arterial shunt (75 patients) there was little evidence of advatients) pulmonary vascular disease in either histologic C2 of 25 patients) or hemodynamic (1 of 50 patients) studies. After an aortic-pulmonary arterial shunt (44 Waterston, 175 Potts) there was small likelikhood of advanced pulmonary vascular disease with a shunt duration of less than 5 years (1 of 35 histologic, 0 of 27 hemodynamic studies). With a shunt duration of more than 5 years the incidence of advanced pulmonary vascular disease increased significantly (15 of 54 histologic, 17 of 103 hemodynamic studies). A mean pulmonary arterial pressure of 50 mm Hg or greater strongly suggests the presence of advanced pulmonary vascular disease. When a systemic-pulmonary arterial shunt has provided effective palliation with decreased pulmonary pressure there is small likelihood that advanced pulmonary vascular disease will develop, even with a long shunt duration of 20 to 25 years.

Aorta↗
PubMedDate not supplied

Nonoperative treatment of double lateral ligament tears of the ankle.

In this article the objective evaluation of 39 cases of double lateral ligament tears of the ankle treated by cast immobilization is described. Such treatment resulted in a 79.5% success rate as determined by repeat stress roentgenograms. In addition, a statistical method which may aid the orthopaedist in deciding whether to use nonoperative or operative treatment is presented.

Adolescent↗