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Biomedical subjects

B T Katzen

Publications and source records attributed to B T Katzen.

At least 55 records · Page 3Linked to original sources
PubMed1989

Noncoronary angioplasty.

PTA is an established method of revascularization in a variety of medical conditions. It is performed for specific morphologic and clinical indications. PTA is the procedure of choice in Fontaine stage IIB through IV lower extremity ischemia due to iliac and/or femoropopliteal stenosis or short occlusion. Its role is less certain in infrapopliteal disease, although current studies have begun to establish long-term effectiveness. PTA is the procedure of choice for renal revascularization in renovascular hypertension due to fibromuscular disease or non-ostial atherosclerosis, selected cases of renal artery stenosis associated with renal insufficiency, and transplant renal artery stenosis. It is also useful in treating the renovascular component of complex hypertension and may be indicated in severe renal artery stenosis (75%-99%), even in the absence of clinically demonstrable RVHTN. PTA has limited applications in the venous system and only short-term success in the treatment of stenoses in dialysis access fistulas. PTA often serves as an important adjunct to surgical revascularization by providing improved inflow or outflow. PTA is the procedure of choice when anatomically feasible in subclavian steal syndrome. The role of PTA in carotid artery disease, particularly atheromatous disease of the internal carotid artery, is uncertain. The same may be said of PTA for vertebral artery stenosis, although the overwhelming majority of vertebral artery stenoses are morphologically suitable for PTA. PTA and surgery are both effective in the treatment of abdominal angina. There are more data available to verify the long-term patency of thromboendarterectomy and bypass grafts than PTA for mesenteric ischemia. However, since the technical success for PTA is high and since coronary co-morbidity is the most common cause of perioperative mortality in surgical series, PTA should be seriously considered as the procedure of first choice. Serious complications of PTA occur in approximately 5% of cases. Two to three percent of PTA patients have complications requiring surgery or causing a prolongation or alteration of hospital course. The morbidity, mortality, and cost associated with PTA are low. The discomfort is minor, and postprocedural recovery rapid. The major limitations of PTA include its unsuitability for some lesions (long-segment occlusions and stenoses, orifice lesions, eccentric lesions) and postangioplasty restenosis. These problems are being addressed by ongoing laboratory and clinical research. In the near future, it is likely that endoluminal transmural sonography of the vessel wall will help guide our interventions.

Angioplasty, Balloon↗
PubMed1989

Developing an interventional radiology practice in a community hospital: the interventional radiologist as an equal partner in patient care.

Development of an interventional radiology practice or section depends first on the commitment and ability of the interventionalist but is also contingent on an appropriate environment. Moreover, the interventionalist must attempt to change long-standing concepts and referral patterns with aggressive dissemination of information. He or she must be an advocate of the procedures offered, as well as their benefits to the patient and the health care system. One must actively include outpatient visits and admissions as part of services offered. Allies in this effort include primary care physicians, internists, hospital administration, and third-party payers. In addition, organized radiology can now offer some assistance through the Society of Cardiovascular and Interventional Radiology and the American College of Radiology. All of these factors will contribute significantly to the success of interventional radiology in both teaching and community hospital settings.

Hospital Departments↗
PubMed1989

Blue toe syndrome: treatment with percutaneous atherectomy.

"Blue toe syndrome" refers to digital ischemia of the foot in the presence of palpable or Doppler audible pedal pulses. This clinical syndrome is caused by microembolization to small vessels from a proximal source. The use of percutaneous transluminal atherectomy is described in the treatment of embologenic superficial femoral artery lesions in seven patients. All seven had prompt healing of the ischemic toes, and none required surgical revascularization or amputation. One patient developed a recurrent stenosis at the atherectomy site and had a second episode of digital ischemia, which was treated by means of atherectomy with a larger device. Histologic study of atherectomy specimens suggests that emboli arise from adherent fibrinoplatelet aggregates or thrombus and less often from cholesterol-rich atheromatous plaque. Although either percutaneous transluminal angioplasty or atherectomy can be used to treat the underlying stenosis, percutaneous atherectomy offers the advantage of nonsurgical removal of embologenic material and provides material for histologic study. Percutaneous atherectomy is an effective method of treating embologenic superficial femoral stenoses in patients with ipsilateral blue toe syndrome.

Adult↗
PubMed1988

Technique and results of "low-dose" infusion.

The results of 125 urokinase (UK) infusions in 108 patients were analyzed. Results showed total clot lysis in 61% of patients, partial lysis in 24%, and no lysis in 15%. Predictably, patients with acute occlusions had the highest incidence of complete clot lysis. However, clots older than 3 weeks had a surprisingly high lysis rate of 57%. None of the patients had a fibrinogen level below 100 mg/dL. Overall incidence of bleeding (major and minor) was 15%; patients having the most severe bleeding were on concomitant anticoagulation. We conclude that UK is a safe and effective therapeutic option in patients with acute and chronic obstruction. Significant bleeding episodes are uncommon during UK therapy and are related primarily to ongoing anticoagulation.

Arterial Occlusive Diseases↗
PubMed1987

Use of digital subtraction angiography for evaluation of vascular access for hemodialysis.

We used digital subtraction angiography (DSA) with conventional methods of contrast injection to evaluate 13 failing vascular accesses in 12 patients undergoing hemodialysis. DSA results were confirmed in all cases by surgical findings and/or clinical follow-up. The DSA technique is extremely flexible and rapid and requires the injection of only small amounts of dilute contrast with much less patient discomfort. DSA is an excellent alternative to film screen angiography for the evaluation of vascular access complications.

Angiography↗
PubMed1987

Urokinase versus streptokinase in local thrombolysis.

In a retrospective analysis, the efficacy of lysis, the degree of systemic thrombolytic effect, and the rate of complications during local thrombolytic therapy with either streptokinase (SK) or urokinase (UK) were compared in 47 patients. There were 24 infusions of each agent; one patient in the UK group received two infusions. The overall efficacy of lysis was better in the UK-treated group (80% vs. 63%). The UK group had a lower frequency of systemic thrombolytic effect and of bleeding complications. SK antibody titers were measured in all patients who received infusions. Patients with high titers who were treated with SK responded poorly (20% lysis); patients with low titers responded at a rate equal to that of UK-treated patients. Three patients with high titers of SK antibodies did not respond to SK, but subsequent successful lysis did occur with UK. In conclusion, UK is believed to be preferable to SK for local thrombolytic therapy due to increased efficacy of lysis and decreased rate of systemic fibrinolytic effect and bleeding complications.

Antibodies↗
PubMed1987

Treatment of carotid-cavernous fistulas with detachable balloon catheter occlusion.

Intravascular occlusion of traumatic carotid cavernous fistulas, originally performed under direct visualization with fascia and/or muscle, has evolved into the use of catheters with pressure-sensitive detachable balloons that can be deflated and repositioned prior to final inflation and separation from the catheter. The balloon is filled with contrast material and can be identified with follow-up x-rays. Proptosis is often relieved immediately after this treatment. Detailed pre- and posttreatment ophthalmic evaluations of three consecutive patients with carotid-cavernous fistulas successfully treated with detachable balloon occlusion with a minimum 1-year follow-up are presented. Indications and timing of treatment are discussed. Following blunt head trauma, these patients presented with proptosis, decreased vision, orbital bruit, conjunctival chemosis, diplopia, orbital pain, ocular pulsations and diplopia; they often complained of "a ringing" in the ear on the involved side.

Adult↗
PubMed1985

Impassable urethral strictures: percutaneous transvesical catheterization and balloon dilatation.

Urethral strictures that are impassable in retrograde fashion present a special problem to the urologist because they cannot be managed by standard dilatation techniques or direct-vision internal urethrotomy. Open urethroplasty is usually required. We describe a technique to catheterize the urethra in an antegrade fashion and dilate the strictures. Our study involved six patients with impassable urethral strictures that were successfully traversed and dilated. Percutaneous transvesical antegrade catheterization and balloon dilatation are beneficial for patients with bladder outlet obstruction.

Aged↗
PubMed1984

Low-dose direct fibrinolysis in peripheral vascular disease.

One hundred thirty patients underwent low-dose, catheter-directed fibrinolytic therapy for arterial and graft occlusions present for various periods of time. In 65 consecutive patients the therapeutic parameters were identical, and a careful hematologic evaluation was performed. In the subsequent 65 patients, varying doses of fibrinolytic agents were employed. Fibrinolytic therapy was found to be beneficial in a diverse group of clinical situations and in patients whose occlusions had occurred at varying lengths of time. Early study demonstrated that effective fibrinolysis can be achieved at approximately one-twentieth of the systemic level and that systemic effects could be avoided in all patients during 24-hour infusions and in many patients infused up to 96 hours. Bleeding complications occurred only in patients in whom concomitant heparinization was employed, and this was thought to be the causative factor. Therapeutic success and avoiding complications are strongly dependent on close monitoring of patients and joint decision making by the vascular surgeon and radiologist.

Arterial Occlusive Diseases↗
PubMed1984

Percutaneous transluminal angioplasty for arterial disease of the lower extremities.

Percutaneous transluminal angioplasty has become an effective method of restoring blood flow and relieving symptoms of peripheral arterial disease in the lower limbs. It has the advantages of less pain, morbidity, and cost compared with surgery. Best results are in short stenotic lesions where the patency rate at 2 years in iliac, superficial femoral-popliteal arteries, and popliteal arteries is 85%-90%, 50%-75%, and 70%-80%, respectively. Complications of distal embolization, thrombosis, and perforation occur in 3%-5% of attempts and require immediate surgery. Some considerations for the selection of patients, approach, technique, and use of drugs to control arterial spasm and thrombosis are reviewed briefly.

Angiography↗