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Biomedical subjects

B T Katzen

Publications and source records attributed to B T Katzen.

At least 37 records · Page 2Linked to original sources
PubMed1992

Intravascular stents. Status of development and clinical application.

A variety of intravascular stents are currently under investigation and in various stages of achieving governmental approval for clinical application. The Palmaz balloon-expandable stent has recently been approved for use in the iliac arteries based on specific indications for application. Stents are generally described according to their method of deployment and are either balloon-expandable or self-expanding. Clinical application has been proved in the iliac arteries, where the use of stents has greatly enhanced the treatment of patients with total occlusions, complex dissections, and restenoses. Additionally, there is promise that stents will enhance the percutaneous treatment of renal artery ostial lesions, infrainguinal arterial lesions, and strictures in large veins. Clearly, the increasing application of intravascular stents has ushered in a new era of percutaneous intervention.

Arterial Occlusive Diseases↗
PubMed1992

Low-dose urokinase regimen for the treatment of lower extremity arterial and graft occlusions: experience in 132 cases.

In a retrospective review, a low-dose urokinase (UK) infusion regimen (mean, 87,000 U of UK per hour and 100 U of heparin per hour) was evaluated for lower extremity arterial and graft occlusions. Results of 132 infusions in 111 patients were analyzed to determine efficacy, limb salvage, and complications. Angiographic success was achieved with 126 infusions (95%), and amelioration of presenting signs and symptoms was achieved after 116 infusions (88%). Patients who underwent additional percutaneous procedures were more likely to have a successful outcome. There was no significant difference in success rates for patients receiving low-dose heparin through the arterial sheath (n = 101) versus those receiving concomitant systemic heparinization (n = 29), (P = .08) [corrected]. Of 88 threatened extremities (with rest pain, cold, ulcers, or gangrene), nine were amputated (limb salvage = 90%), accounting for 82% (nine of 11) of amputations in the overall study. Patients with zero- or one-vessel runoff before infusion were more likely to require limb amputation compared with the group with two- or three-vessel runoff before infusion (P less than .01). Major periprocedural complications occurred in nine of 132 (7%) infusions, five of which necessitated specific surgery and/or transfusion for bleeding. Pericatheter thrombosis was not encountered in either subgroup. This standard local low-dose infusion represents a safe and effective treatment for lower extremity arterial and graft occlusions.

Aged↗
PubMed1992

Superior mesenteric artery embolism: treatment with intraarterial urokinase.

Four patients with a superior mesenteric artery (SMA) embolism were successfully treated with intraarterial urokinase. Angiography showed partial SMA occlusion by intraluminal thrombus in two cases and almost total occlusion in two cases. Laparotomy was performed in the latter two cases, one of which required resection of infarcted bowel. Several additional reports of partially occluding SMA emboli treated successfully with streptokinase were found in the literature. The use of intraarterial thrombolytic drugs is an important addition to the treatment of mesenteric embolism that, in some cases, can eliminate or simplify surgical management.

Aged↗
PubMed1992

Neutralized lidocaine: use in pain reduction in local anesthesia.

The effect of pH neutralization on the pain experienced during intradermal lidocaine administration was investigated in a prospective blind study of 20 adult volunteers. A plain solution (pH congruent to 6.1) and three different buffered solutions of 1% lidocaine (pH values of 6.8, 7.0, and 7.2) were prepared, and a 0.5-mL intradermal injection of each was administered to the volar aspect of the forearm. Pain associated with lidocaine infiltration was rated with a linear visual analogue scale. Solutions with a pH of less than 6.8 (unbuffered lidocaine in this study) predictably produced a burning pain sensation on injection. However, buffering of 1% lidocaine above a pH of 6.8 significantly (P less than .05) reduced the mean quantitative pain estimates compared with the nonbuffered controls.

Adult↗
PubMed1992

Technical advances in transjugular intrahepatic portosystemic shunts.

A transjugular intrahepatic portosystemic shunt (TIPS) can be created percutaneously with the Palmaz balloon-expandable stent. This article describes a transjugular-only approach with a 16-gauge needle. A functional and efficacious shunt can be achieved in most cases with stent diameters of 8-10 mm. Occasionally, a 12-mm-diameter shunt is necessary for effective variceal decompression. The procedure is considered successful when the portosystemic gradient is lowered to 12 mm Hg or less after stent placement. Hepatic vein stenosis in the shunt outflow can develop after the TIPs procedure. This complication has been treated successfully with additional stent placement. TIPS can undoubtedly be performed successfully and safely with a transjugular-only approach; however, the full impact of TIPS on the treatment of portal hypertension remains to be determined.

Esophageal and Gastric Varices↗
PubMed1992

Current status of intravascular ultrasonography.

Intravascular ultrasonography provides unique diagnostic information about vessel wall structure and underlying disease. It has been shown to be superior in both the detection of atherosclerotic plaque and in the quantification of extended disease. Future applications will include three-dimensional ultrasound and integration into interventional devices. It has been of particular clinical value in the performance of percutaneous atherectomy and intravascular stent deployment.

Arterial Occlusive Diseases↗
PubMed1991

Percutaneous transjugular portosystemic shunt.

OBJECTIVE: --To determine the effectiveness of the Palmaz balloon expandable stent for the creation of a transjugular intrahepatic portosystemic shunt. The device is designed to achieve portal decompression in patients with variceal hemorrhage secondary to portal hypertension. DESIGN: --Transjugular intrahepatic portosystemic shunting was performed in eight patients during a 9-month period. Mean follow-up was 5 months. PATIENTS: --All patients had cirrhosis with portal hypertension and varices. Bleeding occurred in seven patients from esophageal varices and in one patient from hemorrhoids. MAIN OUTCOME MEASURES: --Shunt patency and recurrent variceal hemorrhage. RESULTS: --Shunts created from a transjugular approach between a hepatic and a portal vein (diameters of 8 to 12 mm) lowered the average portosystemic pressure gradient from 36 to 11 mm Hg. Mean postoperative hospital stay was 7.7 days. Complete variceal decompression after transjugular intrahepatic portosystemic shunt placement was identified endoscopically in all eight patients. The patient treated for hemorrhoids rebled and was treated successfully by transfemoral balloon expansion of the shunt diameter from 8 to 12 mm. All shunts were patent at 1 to 9 months (mean, 5 months) of follow-up. CONCLUSION: --Initial results suggest that transjugular intrahepatic portosystemic shunt is a safe and effective method of portal decompression for the treatment of variceal hemorrhage.

Angioplasty, Balloon↗
PubMed1991

Percutaneous placement of a balloon-expandable intraluminal graft for life-threatening subclavian arterial hemorrhage.

A balloon-expandable intraluminal graft was percutaneously deployed in the left subclavian artery of a 43-year-old woman. This graft was made of a stainless steel, 30-mm Palmaz balloon-expandable iliac stent completely covered with a thin coat of silicone. The procedure was successful in managing and preventing life-threatening hemorrhage as a large-bore catheter was removed from the subclavian artery via its subcutaneous tunnel. Surgical repair of the high brachial-axillary sheath insertion site was required after percutaneous deployment of the graft. However, the grafting procedure succeeded in obviating a thoracotomy. At follow-up of 6 months, despite diminution in brachial pulse volume recordings, the patient is asymptomatic at rest. She experiences mild fatigue with extremes of upper extremity exercise and declines angiographic follow-up and further intervention.

Adult↗
PubMed1991

Compact contrast material bolus with a new 5-F angiographic catheter.

The conventional pigtail catheter was compared with the 5-F Tennis Racquet catheter for abdominal aortography with digital subtraction angiography. Resulting aortograms were judged on the basis of the quality of aortic opacification and renal artery visualization. The authors concluded that the Tennis Racquet catheter produces a more compact contrast material bolus, and its use is associated with acquisition of superior abdominal aortograms.

Angiography, Digital Subtraction↗
PubMed1991

Relative cost-effectiveness of urokinase versus streptokinase in the treatment of peripheral vascular disease.

A retrospective case control study of 271 patients with peripheral arterial occlusion (PAO) who were treated with urokinase (UK) or streptokinase (SK) at two clinical centers, Alexandria Hospital and the Cleveland Clinic, was performed. The primary objective was to evaluate the relative cost-effectiveness of thrombolytic therapy with SK or UK in the treatment of PAO. A secondary objective was to identify factors to which any major differences in cost-effectiveness between these two agents could be attributed. All available patients hospitalized at the two centers for PAO who underwent treatment with UK or SK from 1979 to 1987 were included. Therapeutic success was defined as complete clot lysis or partial clot lysis judged to be of clinical benefit by the attending physician, with no major bleeding or other serious complication such as renal insufficiency or death. Success rates with UK were higher than those with SK at both centers. The advantage with UK could not be explained by baseline patient characteristics. A cost-effectiveness ratio--dollars expended on medical care for up to 2 days after infusion per therapeutic success--was calculated for each of the treatments. Overall, at Alexandria Hospital, $10,700 was expended per therapeutic success with UK therapy compared with $14,500 for successful SK therapy. At the Cleveland Clinic, differences were more pronounced, with $15,000 expended per therapeutic success for UK treatment and $46,400 per success for SK treatment. Support for preference of UK therapy is provided by the consistency of results in favor of UK cost-effectiveness for subgroups of patients that were determined according to site of occlusion and type of therapy following lysis. The cost-effectiveness of UK was not dependent on the definition of patient costs associated with PAO.

Aged↗
PubMed1991

Palmaz stent in atherosclerotic stenoses involving the ostia of the renal arteries: preliminary report of a multicenter study.

Palmaz balloon-expandable stents were placed in 28 hypertensive patients with atherosclerosis involving the ostia of the renal arteries. Stents were placed to treat elastic recoil immediately after conventional angioplasty in 20 patients and restenosis after percutaneous transluminal angioplasty in eight patients. Technical success (greater than 30% residual stenosis) was achieved in 27 patients. Complications occurred in five patients. At follow-up (1-25 months), hypertension was cured in three patients and improved in 15 patients, with a cumulative cure or improvement of 64% at 6 months. Of 14 patients with a serum creatinine level of 1.5 mg/dL (132.6 mumol/L) or greater before the placement of stents, five demonstrated improved renal function, five showed stabilization of their condition, and four demonstrated deterioration. Follow-up angiography (2-18 months) was performed in 18 patients. Restenosis was present in seven patients and was accompanied by a relapse of hypertension in only three patients. Of the other four patients with restenosis, two had no initial improvement and two had an initial response without a relapse of hypertension. In this preliminary study, renal stents were beneficial in many patients with poor results from conventional angioplasty for ostial atheroma.

Aged↗
PubMed1990

Directional atherectomy in the treatment of stenotic dialysis access fistulas.

Directional atherectomy has proved useful in the treatment of peripheral vascular occlusive disease, and the authors have begun using this modality in the treatment of patients with failing hemodialysis access fistulas. The authors describe their initial experience with 13 patients in whom directional atherectomy was used to treat stenotic hemodialysis fistulas. Directional atherectomy was the sole treatment modality for eight patients. Three patients underwent atherectomy after unsuccessful percutaneous transluminal angioplasty (PTA). In two patients, unsuccessful atherectomy necessitated subsequent PTA. Directional atherectomy was successful in 10 of 13 patients. In seven of these 10 patients who are still alive, the dialysis fistulas remain patent. Directional atherectomy is a safe and useful technique in the percutaneous treatment of hemodialysis fistula stenosis. Early data indicate patency rates that may be higher than those reported with PTA.

Arteriosclerosis↗
PubMed1990

The cause of superior vena cava syndrome: diagnosis with percutaneous atherectomy.

The cause of superior vena cava syndrome (SVCS) in two patients was identified by means of endovascular biopsy of the superior vena cava (SVC) performed with a percutaneous atherectomy catheter. In both cases, the extracted tissues were neoplastic, therefore obviating additional invasive procedures. After a specific diagnosis was established, external-beam radiation therapy was used to treat the SVCS. The atherectomy catheter was used in conjunction with other percutaneous techniques, including balloon angioplasty and endovascular stenting of the SVC.

Adenocarcinoma↗