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Biomedical subjects

T A Matalon

Publications and source records attributed to T A Matalon.

At least 19 recordsLinked to original sources
PubMed2000

Thrombolytic therapy with use of alteplase (rt-PA) in peripheral arterial occlusive disease: review of the clinical literature. The Advisory Panel.

PURPOSE: The clinical literature describing the use of alteplase in the treatment of peripheral arterial occlusive (PAO) disease is reviewed. MATERIALS AND METHODS: The literature database was acquired by a MEDLINE search using the Boolean keyword string: tissue plasminogen activator and/or rt-PA and peripheral not animal. A review was performed to identify the dose range of alteplase, technique of infusion, use of anticoagulation, clinical success rates, and risk of complications. RESULTS: Forty-six clinical studies were identified. There are few prospective, randomized clinical trials and a lack of standardized protocols and endpoints. Use of catheter-directed infusions of recombinant tissue plasminogen activator (rt-PA) may be beneficial versus surgery in the initial management of acute limb ischemia (< 14 days) and in reducing the magnitude of subsequent surgical or percutaneous revascularization. For patients with chronic limb ischemia (> 14 days), irreversible acute limb ischemia, or advanced diabetic arteriopathy, catheter-directed infusion of rt-PA or other plasminogen activators may be unsuitable. The risk of adverse bleeding appears related to the overall dose and duration of infusion. These risks appear similar to those of urokinase. The role of heparin in increasing adverse bleeding during rt-PA therapy is unclear. CONCLUSIONS: There is no generally accepted dose or technique for administering catheter-directed thrombolysis using alteplase; however, several studies have demonstrated its clinical safety and efficacy. Formal studies will be required to determine the optimal dose, technique of infusion, the role of anticoagulation, and complication rates when alteplase is used for PAO disease.

Arterial Occlusive Diseases↗
PubMed2000

Hydrodynamic thrombectomy system versus pulse-spray thrombolysis for thrombosed hemodialysis grafts: a multicenter prospective randomized comparison.

PURPOSE: To evaluate the safety and efficacy of a hydrodynamic thrombectomy system in a prospective, multicenter randomized comparison with pulse-spray thrombolysis in hemodialysis grafts. MATERIALS AND METHODS: Nine centers enrolled 120 adult patients with recently (</=14 days) thrombosed hemodialysis grafts. Graft venography was used to confirm occlusion in 62 patients randomly assigned to thrombectomy and 58 to thrombolysis. For thrombolysis, a mixture of 5,000 U of heparin and 250,000 U of urokinase was distributed throughout the thrombus, first to the venous then to the arterial graft end. For thrombectomy, the catheter was passed in the same sequence. Technical success was removal of 80% or more of thrombus. Clinical success was technical success plus the ability to dialyze. Also assessed were total procedure time, thrombus treatment time, procedure-related blood loss, other complications, and 30- and 90-day outcomes. RESULTS: Patient demographics were comparable. Technical success rates were 95% (59 of 62) for thrombectomy and 90% (52 of 58) for thrombolysis (P: =.31). Clinical success rates were 89% (55 of 62) and 81% (47 of 58), respectively (P: =.24). At 30 days, 69% (43 of 62) and 66% (38 of 58), respectively, could be dialyzed through the graft (P: =.70); at 90 days, the rates were 40% (25 of 62) and 41% (24 of 58), respectively (P: =.91). None of these differences or those for procedure-related blood loss and early and late complications were statistically significant. Thrombus treatment times of 16.8 minutes for thrombectomy and 23.4 minutes for thrombolysis were significantly different (P: <.01). CONCLUSION: The hydrodynamic thrombectomy system is at least as efficacious and safe as pulse-spray thrombolysis but shortens thrombus treatment time.

Adult↗
PubMed1999

Transjugular intrahepatic portosystemic shunt (TIPS) for Budd-Chiari syndrome or portal vein thrombosis: review of indications and problems.

OBJECTIVE: The aim of this study was to evaluate the role of transjugular intrahepatic portosystemic shunt (TIPS) in patients who present with portal vein thrombosis (PVT) or Budd-Chiari Syndrome (BCS). METHODS: Nine patients with recent PVT and four patients with BCS underwent TIPS. The diagnosis was confirmed by color Doppler ultrasound and by angiogram in most patients. Patients were followed clinically and had TIPS checked periodically for patency. The end point was mortality, subsequent surgical shunting or orthotopic liver transplantation (OLT). RESULTS: TIPS was placed in 13 of 15 (87%) patients with BCS or PVT. The mean decrease in pressure gradient was 56%. Median and mean follow-up were 14 months and 16.9 months. Procedure related complications occurred in two of 13 (15%), both in the PVT group. Direct procedural mortality was one of 13 (8%). The majority of patients with PVT (five of eight) underwent OLT. Of the remaining three, one patient subsequently developed a cavernous transformation of portal vein but is stable, one patient is stable, without further variceal bleeding, and one patient died because of multiple organ failure. In patients with BCS, three of four (75%) did well with TIPS, but one patient required immediate surgical shunting after occlusion of the TIPS. Two patients underwent OLT and the fourth patient is stable 2 yr later but has cirrhosis on biopsy. CONCLUSIONS: In patients with BCS, TIPS placement is effective and can be used as a bridge to liver transplantation. TIPS in the noncavernous PVT group should only be recommended when cirrhosis and uncontrollable variceal bleeding are present.

Adult↗
PubMed1996

Feasibility of using a swine portal vein containing a metallic stent for creating a portacaval shunt.

RATIONALE AND OBJECTIVES: We evaluated the feasibility of using a metallic stented portal vein as a conduit for portacaval shunt in pigs. METHODS: A metallic self-expanding stent was placed in the portal vein of five pigs under combined ultrasound and fluoroscopic guidance via a percutaneous transhepatic approach. After 6 weeks, a portacaval shunt was performed using the stented portal vein as a conduit. A single angiogram followed immediately by sacrifice and histologic examination was performed on each pig at a varying time interval postshunt. RESULTS: One pig died 3 days after the shunt procedure because of a presumed surgical technical failure and a consequent thrombosed portal vein. Angiographic patency of the portacaval shunt was confirmed in the four remaining pigs. Postmortem histologic evaluation showed more complete endothelialization and subintimal organization in the more chronic stents. Thrombus occurred only in the stent of the pig that died. There was no significant luminal obstruction in the other four stents. CONCLUSION: Our results suggest that a stented portal vein can be used successfully as a conduit for portacaval shunt in pigs.

Angiography↗
PubMed1995

Transjugular intrahepatic portosystemic shunt in nonliver transplant candidates: is it indicated?

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) is an effective treatment of severe portal hypertension complications. Liver transplantation (LT) candidacy has not been a prerequisite to TIPS placement in some medical centers. OBJECTIVES: To investigate the outcome and survival of non-LT candidates after TIPS. METHODS: From November 1991 to February 1994, all patients referred for TIPS placement were evaluated for LT candidacy. Exclusions for LT included: age (> 70 yr), other significant medical conditions, or noncompliance. Indications for TIPS included refractory variceal bleeding during an acute bleed, recurrent bleeding after more than or equal to four sessions of sclerotherapy, or refractory ascites. RESULTS: Sixty patients received TIPS. Nineteen were considered non-LT candidates. Over a 2-yr follow-up, 14 of these non-LT candidates did not survive. Their median age was 63.5 compared with 56.5 yr for LT candidate nonsurvivors (p < 0.05). Among the 14 non-LT candidate nonsurvivors, 10 were Childs C class, and eight had emergent TIPS placement. The 2-year mortality rate was 84% for non-LT candidates versus 24% for LT candidates. Median survival time for non-LT candidates was 2.6 months compared with 20 months in the LT candidates (p < 0.001). Only one death was due to a TIPS-related complication. CONCLUSIONS: TIPS is unquestionably an advancement in the management of patients with portal hypertension complications. Non-LT candidates, compared with LT candidates, tended to be older and of a Child-Pugh C class, and they had survival rates often less than 90 days post-TIPS. Given these high mortality rates, we need to address whether TIPS is indicated in these non-LT candidates.

Esophageal and Gastric Varices↗
PubMed1992

Percutaneous transluminal angioplasty for transplant renal artery stenosis.

A recent report has challenged the efficacy and safety of percutaneous transluminal angioplasty (PTA) for the treatment of transplant renal artery stenosis (TRAS). From January 1983 to December 1990, 24 PTA procedures were performed for TRAS in 18 patients. The stenoses were anastomotic in two cases, in the main renal artery in 14, and segmental in eight. After PTA, the residual stenosis was less than 20% in 14 (58%), 20%-50% in four (17%), and greater than 50% in six (25%). The mean diastolic blood pressure decreased from 106 mm Hg 1 day prior to PTA to 82 mm Hg 1 day after PTA. Long-term follow-up mean diastolic blood pressure (at 2-32 months) was 93 mm Hg (P less than .01). Eleven of the 18 patients (63%) had a 10% or greater reduction in diastolic blood pressure on long-term follow-up. Major complications occurred in two patients; one groin hematoma required surgical evacuation, and one polar infarct led to hypertension that was difficult to control. No surgical revisions of the transplant renal artery were necessary. The authors' data indicate that PTA should remain the treatment of choice for nonanastomotic TRAS.

Adult↗
PubMed1991

Ultrarapid urokinase in hemodialysis access occlusion.

Over a 3-month period, 14 consecutive hemodialysis access occlusions were treated with 1-1.25 million IU of urokinase (UK) delivered at a rate of 20,000 IU/min. After systemic heparin administration, lytic infusion via the crossed-catheter technique was performed with use of pediatric microdrip pumps, with determination of success within 1 hour. Patency was established radiographically in 11 of 14 occlusions, for a 79% immediate success rate. At 285-day mean follow-up, 9% (one of 11) remained patent without further radiologic or surgical intervention; graft survival was 64% (seven of 11). No significant complications occurred with use of ultrarapid UK. The 1-hour outpatient procedure safely allowed for rapid triage between surgical and radiologic intervention, minimal catheter manipulation or physician dependency, shorter duration compression of any bleeding venipuncture sites during UK administration, and greater patient comfort because of shortened procedure times.

Arteriovenous Shunt, Surgical↗
PubMed1991

Biliary strictures in hepatic transplantation.

Between August 1985 and December 1990, 198 liver transplantations were performed. Among 18 patients, 20 biliary strictures were identified, which were categorized as anastomotic (n = 6), nonanastomotic central hilar (n = 8), and nonanastomotic peripheral (n = 6). Pretransplant disease, hepatic artery patency, presence of acute or chronic rejection, and donor cold ischemia times were tabulated for each case. Among the six patients with peripheral strictures, three had sclerosing cholangitis prior to transplantation. Three patients with nonanastomotic strictures experienced chronic rejection. The mean cold ischemia time for patients with nonanastomotic strictures was 9.75 hours versus 8.1 hours for nonstrictured transplants (P = .025). Balloon dilation was performed in 13 patients; follow-up longer than 6 months was available for nine patients. Dilation was successful in four cases. Among the five failures, only one patient has needed surgery. An association was noted between nonanastomotic biliary strictures and prolonged donor cold ischemia time, between peripheral nonanastomotic strictures and pretransplant sclerosing cholangitis, and between nonanastomotic strictures and chronic rejection. Percutaneous balloon dilation was found useful in the treatment of the strictured transplant.

Biliary Tract Diseases↗
PubMed1990

Embolization of a giant renal arterial aneurysm.

A 49-year-old man presented with right flank pain. Angiography revealed a giant right renal arterial aneurysm. Giant renal arterial aneurysms are typically treated by nephrectomy. In this patient the aneurysm was embolized successfully with multiple Gianturco-Wallace coils and polyvinyl alcohol. This case indicates that embolization may be a reasonable alternative to nephrectomy.

Aneurysm↗
PubMed1990

US guidance of interventional procedures.

Advances in ultrasound (US) machine and transducer design have improved the ability of US to guide interventional procedures. Though affording excellent guidance without radiation and at relatively low cost, US remains underutilized because of lack of understanding and experience in this technique. This article illustrates the role that US has in interventional radiology and explains how to place a needle in a target under US guidance.

Biopsy, Needle↗