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J J Bookstein

Publications and source records attributed to J J Bookstein.

194 records · Page 11Linked to original sources
PubMedDate not supplied

Transcatheter manipulation of asymmetrically opened titanium Greenfield filters.

PURPOSE: The problem of asymmetric opening of the modified hook titanium Greenfield inferior vena cava filter necessitating transcatheter manipulation was evaluated in a retrospective study. PATIENTS AND METHODS: Titanium Greenfield filters were placed in 166 patients over a 36-month period. The radiographic reports of all patients were reviewed to identify cases in which the filter failed to open symmetrically after deployment and catheter or wire manipulation of the filter was performed. The reports and angiograms from these patients were reviewed with respect to the circumstances surrounding filter placement and methods to achieve more symmetric opening. RESULTS: Transcatheter manipulation of asymmetrically opened filters was performed in 15 of 166 cases (9%). In 12 of these patients, acceptable and uneventful opening of the filter was achieved with a guide wire, pigtail catheter, or occlusion balloon catheter. In one case manipulation only partly improved orientation of the limbs, while in another case successful manipulation was complicated by distal migration. In the final case, the asymmetric filter covered only part of the lumen of the vena cava despite manipulations and a second filter was placed for optimal caval interruption. No specific cause for incomplete expansion was identified in any case. CONCLUSION: Marked asymmetry in opening of the modified hook titanium Greenfield filter that warrants manipulation occurs infrequently, but recognition and proper management may be important to ensure optimal caval interruption.

Catheterization, Central Venous↗
PubMedDate not supplied

Use of a direct thrombin inhibitor (argatroban) during pulse-spray thrombolysis in experimental thrombosis.

PURPOSE: To evaluate the effectiveness of intravenous and intrathrombic injection of the thrombin inhibitor argatroban during pulse-spray pharmacomechanical thrombolysis (PSPMT) in experimental venous thrombosis. MATERIALS AND METHODS: Clots were produced in the inferior vena cava in 52 rabbits by placement of steel coils and balloon injury to the vessel wall. Two days later, clots were treated with PSPMT. Several treatment methods were used: intrathrombic saline, intrathrombic tissue plasminogen activator (t-PA), intrathrombic t-PA with intrathrombic and intravenous heparin, intrathrombic t-PA with intravenous argatroban, and intrathrombic t-PA with intrathrombic and intravenous argatroban at two different doses. After treatment, the rabbits were killed and residual clot was weighed. Pretreatment clot weight was estimated and clot lysis was assessed. RESULTS: PSPMT with t-PA and adjunctive intrathrombic heparin resulted in greater lysis than PSPMT with only t-PA (percentage of residual clot, 59% +/- 14 vs 81% +/- 28; P = .02). Addition of intravenous argatroban did not increase lysis, but adjunctive intrathrombic argatroban significantly increased lysis at low doses (37% +/- 16; P = .02) and high doses (34% +/- 6; P = .006) compared with t-PA and intrathrombic heparin. CONCLUSION: In a rabbit model of venous thrombosis, the use of intrathrombic argatroban during PSPMT with t-PA significantly improved clot lysis.

Animals↗
PubMedDate not supplied

Experimental investigation of hypercoagulant conditions associated with angiography.

PURPOSE: To evaluate changes in blood coagulability after high-velocity intravascular fluid injections under conditions relevant to angiography. MATERIALS AND METHODS: In 101 rabbits, fluids were injected at 1,000 psi (6,890 kPa) via a multiple-side-hole catheter in the abdominal aorta, while blood was simultaneously aspirated via a second downstream catheter. The fluids injected included saline, contrast media, blood, tissue plasminogen activator, and heparin. The aspirate was evaluated for clotting time with an activated clotting time (ACT) device, for elevated levels of plasma hemoglobin to confirm capture of at least part of the injection bolus in the sample, and sometimes for hematocrit or fibrin degradation products (FDP). RESULTS: A single high-pressure injection of 2 mL of saline briefly accelerated the ACT of a blood-saline bolus (mean, 38% +/- 4). The mean volume of the hypercoagulable bolus was 15 mL. Systemic FDP levels became elevated within a few minutes after initial injection, suggesting activation of the fibrinolytic system by intravascular clot formation. Subsequent injections produced less hypercoagulability, probably reflecting the anticoagulant effects of FDP. Pressure-injected contrast agents had anticoagulant effects. The ACT was accelerated by up to 80% after injection of blood that had remained within the catheter for 3-10 minutes. Glove powder or gauze lint from wiping the guide wire markedly accelerated intracatheter clotting. Hypercoagulability after injection of clotting blood was partially prevented by injections with contrast agent and was completely inhibited by low-dose systemic heparinization. CONCLUSION: A hypercoagulable bolus may occur after angiographically relevant high-pressure fluid injections. The major contributing factors appear to be high jet velocities and injection of small amounts of clotting blood. Heparinization provides a simple and effective means of prevention.

Angiography↗
PubMedDate not supplied

Augmented pulse-spray thrombolysis with tPA by early pulsed intrathrombic plasminogen enrichment.

PURPOSE: This study was designed to evaluate the efficacy of plasminogen enrichment of subacute thrombus in further accelerating pulse-spray pharmacomechanical thrombolysis (PSPMT) with urokinase (UK) or tissue plasminogen activator (tPA) in a rabbit model. MATERIALS AND METHODS: With use of a subacute rabbit inferior vena cava (IVC) thrombosis model, 78 rabbits were divided into eight groups according to the agents used for thrombolysis: (i) controls (IVC thrombosis, no lysis performed), (ii) pulse-spray thrombolysis with saline only, (iii) PSPMT with UK, (iv) PSPMT with UK, plus interim pulse-spray plasminogen enrichment after 14 minutes, (v) pulse-spray plasminogen enrichment, followed at 10 minutes by PSPMT with UK, (vi) PSPMT with tPA, (vii) PSPMT with tPA, plus interim plasminogen enrichment, and (viii) pulse-spray plasminogen enrichment, followed at 10 minutes by PSPMT with tPA. RESULTS: Intrathrombic pulsed injection of glu-plasminogen after 14 minutes of tPA PSPMT demonstrated significant augmentation of lysis (approximately 31% decrease in residual thrombus) compared with tPA alone (P = .006). Lysis was not augmented significantly when plasminogen was sprayed into thrombus before tPA, or before or after UK. CONCLUSION: Plasminogen enrichment of thrombus after onset of PSPMT with tPA significantly accelerated thrombolysis in a subacute in vivo rabbit model. A clinical trial of this method may be warranted.

Animals↗
PubMedDate not supplied

Comparative efficacy of coronary vasodilatory methods.

The relative efficacy and sequelae of several coronary vasodilator methods were compared in dogs. Maximal coronary vasodilation with least apparent side effect was achieved with infusion of adenosine triphosphate (ATP) at the rate of approximately 600 microng/minute (approximately 20 microng/kg/minute). This method increased conductance to 7 to 8 times control levels and may have fully depleted vasodilator reserve. Bolus injections of ATP or papaverine alone increased conductances three to four fold and approximated the effects of 15 seconds of occlusion of the circumflex coronary artery. Duration of effect was variable. Diatrizoate injections were somewhat less effective vasodilators and produced greater electrocardiographic and systemic effects. Bolus injections of mixtures of ATP and papaverine demonstrated additive effects, and increased conductance 5 to 6 times control levels. In further exploring the diagnostic value of vasodilatory redistribution of myocardial blood flow or appearance of collateral circulation as a sign of a hemodynamically significant stenosis, selective intracoronary infusion of ATP is a promising vasodilatory method.

Adenosine Triphosphate↗
PubMedDate not supplied

Comparative hemodynamic effects of coronary vasodilators and contrast material on the normal and ischemic canine myocardium: determination of the optimal agent for clinical augmentation of coronary blood flow.

The systemic hemodynamic and myocardial effects of potent vasodilators administered directly into the left coronary artery were determined and compared with the actions of contrast material in 10 anesthetized dogs in the normal state and in the presence of segmental myocardial ischemia. Contrast material (Renografin 76) caused systemic hypotension, rise in left ventricular diastolic pressure and decreases in LV dp/dt and dp/dt/LVP in both states. Doses of ATP (7.2 microgram/kg and 20 microgram/kg/min) which are maximally effective in augmenting coronary blood flow caused only mild arterial hypotension and minimal inotropic effects in both states. Nitroglycerin (3 microgram/kg and 10 microgram/kg/min) induced no inotropic effects but slightly greater arterial hypotension than ATP in both states. On the other hand, papaverine HCl (300 microgram/kg and 800 microgram/kg/min) induced profound increases in LV dp/dt and dp/dt/LVP, decreases in LVEDP and arterial hypotension in the non-ischemic state. In the presence of segmental ischemia, papaverine HCl caused significantly less increases in LV dp/dt and dp/dt/LVP, paradoxical increases in LVEDP in 5 dogs and ventricular fibrillation in 3 dogs. Thus, maximally effective vasodilatory doses of ATP causes only small alterations in hemodynamics and myocardial contractile state of the normal and ischemic heart. Similar doses of papaverine induce profound positive inotropic effects which are apparently deleterious to the ischemic heart.

Adenosine Triphosphate↗
PubMedDate not supplied

Non-occlusive ischemic colitis: angiographic aspects in a canine model.

A model of non-occlusive colonic ischemia (NCI) was produced in the dog, incorporating both moderately decreases systemic pressure and increased intralumenal colonic pressure. These factors may play an etiologic role in human NCL. When differences between mean systemic and mean distention pressures were 30 mmHg or less, severe mucosal injury occured. In no case was the muscularis injured. Moderate systemic hypotension alone, or moderate colonic distention alone, did not produce significant colonic ischemic injury. Colonic distention with pressures of 60 mmHg alone resulted in colonic mucosal necrosis, but these pressures are beyond those ordinarily encountered clinically, even in large bowel obstruction. Angiography may be useful in demonstrating reduced flow to the colon during development of colonic ischemic injury. However, angiography is not a sensitive method in the diagnosis of nonocclusive colonic ischemic injury, once that injury has been established and inciting factors have subsided.

Angiography↗
PubMedDate not supplied

The effect of vasospasm on perfusion radionuclide imaging in experimental pulmonary embolism.

Experiments were conducted to further evaluate previously observed discrepancies between postembolic perfusion scans and angiograms, and the relationship of these discrepancies to pulmonary vasospasm. Nonresorbable emboli were formed from Ivalon, muscle, or heated autologous clot. Scans and angiograms were compared at 24-hour intervals for two to eight days. During the first two days after embolism, angiographic-scan discrepancies occurred in most dogs, characterized by decreased size of scintigraphically demonstrated perfusion defects at the same times that the angiogram showed stable or even progressive obstruction. This discordant behavior of scan and angiogram is thought to reflect subsidence of postembolic vasospasm. In the 17 experimental dogs, 13 showed evidence of vasospasm, and four did not. In those that developed spasm, direct angiographic evidence of such spasm was present in all but one, manifest as diffuse constriction of small arteries and diminished parenchymal stain in vascular beds that were not directly obstructed mechanically. Although spasm diminished rapidly during the first 6 hours, there was continued and appreciable further resolution for over 48 hours in some dogs. This study reconfirms the frequent existence of vasospasm in three different embolic models, and indicates subsidence of spasm over a much longer time frame than was formerly supposed. Regression of spasm over an interval of several days suggests that perfusion scans should be performed clinically as soon as possible after a suspected embolic episode, prior to subsidence of spasm, in order to exploit the added sensitivity provided by spasm.

Angiography↗