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PubMed1982

Intracoronary streptokinase in clinical practice.

The candidacy for streptokinase (SK) infusion was studied in 95 patients displaying ECG evidence of acute or impending infarction who were catheterized within 5 hours of the onset of chest pain. Intracoronary SK was administered to 84 patients in whom occlusions of the infarct-related vessel were identified, with early recanalization having been achieved in 74 (88%). Because of completeness of studies, a data base of 72 patients was employed for further analysis. Recanalization was sustained at follow-up in 45 of 55 patients (82%). Spontaneous thrombolysis was demonstrated at follow-up in five patients (8%) initially resistant to SK, and rethrombosis occurred in 10 patients (18%). Preservation of R waves relative to Q wave depth was limited to patients with less than 90% residual stenosis. Eight of nine patients with continuing thrombolysis and patients with recanalized occlusions of the left anterior descending coronary artery displayed more impressive increases in mean (+/- SEM) ejection fraction (47% +/- 4% to 53% +/- 5% [p less than 0.05], and 47% +/- 3% to 52% +/- 5, respectively). The ejection fraction also increased significantly in 15 patients with pre-SK values of less than 50% (41% +/- 2% to 48% +/- 3%; p less than 0.05). Ventricular function deteriorated in SK failures. Reperfusion arrhythmias occurred in 28 of 62 recanalized patients (45%). Minor bleeding tendencies were displayed in 18 of 72 patients (25%). Major hemorrhages, one of which may have been fatal, occurred in four patients (5.6%). Of 84 patients, four (4.7%) died, two of whom were in cardiogenic shock when first seen. In contrast, there were 11 deaths (11.8%) in a consecutive simultaneously enrolled series of 93 control patients with similar entry criteria (p less than 0.05). Two additional SK-treated patients died, 16 and 30 days after treatment, both more than a week after surgical revascularization. It is concluded that SK recanalization is a promising new therapy that may decrease mortality and preserve myocardial function in certain circumstances. Its efficacy in a setting closer to the mainstream of cardiologic practice extends the favorable experience issuing from earlier clinical investigations.

Adult↗
PubMed1992

Relationship between the preexistent coronary collateral circulation and successful intracoronary thrombolysis for acute myocardial infarction.

The purpose of this study was to evaluate whether the existence of coronary collateral circulation influences recanalization rates of intracoronary thrombolysis. The study population consisted of 85 consecutive patients undergoing intracoronary thrombolysis within 6 hours after the onset of the first acute myocardial infarction, all of whom had a complete occlusion of the infarct-related coronary artery. Intracoronary thrombolysis with high-dose urokinase (960,000 IU) was attempted at a rate of 24,000 IU/min. Of 18 patients (group A) who had good angiographic collateral circulation to the area perfused by the infarct-related coronary artery, the obstructed artery was recanalized to a residual luminal diameter stenosis of less than or equal to 90% (successful recanalization) in only five (28%). In contrast, of 67 patients (group B) with poor or no collateral circulation, recanalization was successful in 40 (60%) (p less than 0.05). Antegrade flow of infarct-related arteries was observed following thrombolysis in 12 (67%) of 18 group A patients and in 56 (84%) of 67 group B patients (p = NS). It was concluded that (1) the presence of collaterals correlates with the presence of high-grade stenosis; (2) the presence of collaterals correlates with the presence of high-grade stenosis; (2) the presence of collaterals is inversely related to the efficacy of thrombolytic therapy; and (3) the difference in successful recanalization rates observed between the two groups probably reflects the impact of underlying stenosis severity on the effectiveness of lytic therapy.

Adult↗
PubMed1986

Intracoronary prostaglandin E1 plus streptokinase in acute myocardial infarction.

Fourteen patients with acute myocardial infarction (duration of chest pain 5 +/- 2 hours) received intracoronary infusion of prostaglandin E1 (PGE1) and streptokinase. Intracoronary PGE1 was followed by intracoronary streptokinase in 10 patients (group A), with successful recanalization in all patients. Of 4 patients in whom recanalization failed with intracoronary streptokinase given first (group B), 2 had successful recanalization after addition of intracoronary PGE1. Immediately after successful recanalization, left ventricular ejection fraction increased from 50 +/- 9% to 62 +/- 10% (p less than 0.0008), left ventricular end-diastolic pressure decreased from 20 +/- 10 to 16 +/- 10 mm Hg (p less than 0.05) and stroke volume index increased from 34 +/- 10 to 44 +/- 12 ml/m2 (p less than 0.02). Infarct segment shortening improved from 9 +/- 5 to 18 +/- 4% (p less than 0.0002). Transient hypotension in 1 patient was the only complication. Follow-up catheterization in recanalized patients at 2 to 10 days showed maintained improvement in left ventricular global and infarct segment function. Reocclusion occurred in 1 patient. Thus, intracoronary infusion of PGE1 was effective in establishing reperfusion in all patients when followed by streptokinase and was associated with immediately improved left ventricular global and regional function. PGE1 deserves further evaluation in acute myocardial infarction.

Adult↗
PubMed1996

Evaluation of time-dependent thresholds of cerebral blood flow and transit time during the acute stage of cerebral embolism: a retrospective study.

BACKGROUND: Neurons within the ischemic penumbra are thought to be in a potentially reversible state of ischemic challenge. One therapeutic approach that is being actively explored is the recovery of function of cells within the ischemic penumbra through endovascular recanalization of cerebral arteries occluded with embolus. The purpose of this study was to determine the time-dependent hemodynamic threshold for the prevention of irreversible ischemia in patients with acutely symptomatic internal and middle cerebral artery (MCA) embolism. METHODS: Thirty-six patients admitted within 6 hours of the onset of symptoms of acute cerebral ischemia, due to embolic occlusion of the major trunk of one of the arteries of the anterior cerebral circulation, were studied. On admission, both cerebral blood flow (CBF) and mean transit time (MTT) measurements were obtained following plain computed tomography (CT). All patients were treated by intraarterial administration of urokinase. MTT in the territory of the affected MCA divided by that in the territory of the unaffected MCA was defined as %MTT. RESULTS: A significant negative correlation was found between MTT and CBF. In patients with at least 19 mL/100 g/minute CBF and a maximum of 1.6 %MTT, no cortical infarction occurred whether or not recanalization was obtained. Cortical infarction did not appear in patients with 9 mL/100 g/minute residual CBF and infinite %MTT in whom recanalization was achieved within 2 hours of onset, in patients with 13 mL/100 g/minute residual CBF and 3.7 %MTT in whom recanalization was achieved within 2.5 hours of onset, and in patients with 14 mL/100 g/minute residual CBF and 2.8 %MTT in whom recanalization could be achieved within 3.5 hours of onset. CONCLUSIONS: CBF and MTT thresholds for conversion of reversible to irreversible ischemia can be rapidly determined by CT-based technologies. This type of information should be clinically relevant to guiding the management of patients with cerebral embolism.

Aged↗
PubMed2001

Optimal time for predicting myocardial viability after successful primary angioplasty in acute myocardial infarction: a study using myocardial contrast echocardiography.

This study sought to elucidate serial changes in microvascular integrity during papaverine-induced hyperemia in the risk area for myocardial infarction. In addition, we attempted to determine the optimal time for predicting myocardial viability. Seventy-two patients who underwent serial myocardial contrast echocardiography (MCE) before and shortly after (day 1), 1 day (day 2), and 3 weeks (day 21) after recanalization were studied. In 18 of 72 patients, MCE was performed at baseline and during hyperemia using selective intracoronary infusion of papaverine. Both the peak grayscale ratio (PGSR) within the risk area, and the no- and low-reflow ratio (LR ratio) were analyzed in each stage. Left ventricular regional wall motion (RWM) was determined 6 months after recanalization. The correlation coefficient between PGSR with papaverine on day 1 and that on day 2 was 0.54 (p = 0.02); it was 0.50 (p = 0.04) between day 1 and day 21, and 0.82 (p = 0.001) between day 2 and day 21. On day 1, the correlation coefficient between the LR ratio with papaverine and RWM was 0.60 (p = 0.02), which changed to 0.72 (p = 0.003) on day 2 and 0.54 (p = 0.04) on day 21, respectively. The best time to predict viable myocardium was established on day 2 by receiver operating characteristics curves. ST-segment re-elevation, elapsed time from onset to recanalization, and antecedent angina pectoris were independent factors for PGSR on day 2 using stepwise and multiple linear regression analysis. This study suggests that the optimal time to estimate microvascular integrity for predicting myocardial viability might be 1 day after recanalization, which is neither shortly after recanalization nor during the convalescent stage.

Aged↗
PubMed2000

Acceleration of thrombolysis with ultrasound through the cranium in a flow model.

Thrombolysis is an efficient therapy for hyperacute stroke within a limited time window. Neurological outcome depends on the recanalization time of the occluded vessel. Nonthermal effects of low-frequency ultrasound (US) accelerate enzymatic fibrinolysis in vitro. We examined the effects of transcranially applied US on recombinant tissue plasminogen activator (rt-PA)-mediated thrombolysis in a flow model in vitro. Pure fibrin clots were placed in a continuous-pressure flow model and treated with rt-PA during 1-MHz US exposure (0.5 W/cm(2); spatial peak, temporal peak intensity). Transcranial and direct US application in combination with rt-PA significantly (p<0.001) shortened recanalization time, increased perfusion flow and reperfusion rate in comparison with rt-PA-mediated thrombolysis alone. Recanalization rate within 30 min was 90-100% in the US-exposed clots vs. 30% in the clots treated only with rt-PA. Our results suggest that transcranial application of 1-MHz US may accelerate reperfusion and recanalization rate of occluded intracerebral vessels by enhancing rt-PA-mediated thrombolysis. Shortening of recanalization time could contribute to optimizing effects of acute thrombolytic stroke therapy.

Blood Flow Velocity↗
PubMed1986

Laser angioplasty with angioscopic guidance in humans.

An experimental study was conducted in 11 patients to evaluate the immediate effects of laser recanalization during peripheral arterial bypass surgery. Angioscopy allowed precise localization and identification of the occlusion. A 1 or 2 mm optical fiber probe was used. Laser energy was regulated using the least amount of energy necessary for recanalization. New vascular channels were made in 10 of the 11 patients. After recanalization the arterial segment was excised for histologic evaluation. Smaller channel diameters were made with the 1 mm probe (1.5 +/- 0.6 mm) than with the 2 mm probe (3 +/- 0.3 mm) (p less than 0.05). Flow through channels (mean pressure 80 mm Hg) made with the 2 mm probe was greater than that through channels made with the 1 mm probe (150 +/- 102 versus 19.7 +/- 10 cc/min) (p less than 0.05). The amount of debris formed was small with both probes. Vascular perforations were less frequent with the 2 mm probe (two of nine arteries) compared with the 1 mm probe (four of four arteries). Successful recanalization with flow rates expected to maintain vascular patency was achieved only with the 2 mm probe. Histologic studies at nonperforated sites demonstrated that the elastica of the artery appeared to be preserved whereas the overlying plaque and underlying media were thermally disrupted. This suggests that the elastic tissue acts as an optical window allowing the argon beam to go through it without causing morphologic damage. Except for fresh thrombus, atheromas including calcific plaque and old organized thrombus were readily vaporized. These results are encouraging for the use of the laser for vascular recanalization in humans.

Aged↗
PubMed1997

Induction of cytokine expression in leukocytes in acute myocardial infarction.

OBJECTIVES: This study sought to investigate whether cytokine expression in leukocytes may be induced by plasma from the reperfused heart of patients with an acute myocardial infarction (MI). BACKGROUND: Reperfusion in acute MI is associated with deleterious local and systemic inflammatory responses that are regulated by cytokines. Induction of cytokine expression in resident leukocytes could contribute to inflammatory responses of the ischemic and reperfused heart. METHODS: Blood samples of 10 patients with an acute MI were obtained simultaneously from the coronary sinus and the aorta before and 5 min after recanalization of the coronary occlusion. Ten patients with elective percutaneous transluminal coronary angioplasty served as a control group. We incubated leukocytes from healthy donors with plasma samples and analyzed mRNA expression of interleukin (IL)-1 beta, IL-6, IL-8 and tumor necrosis factor-alpha (TNF-alpha) by Northern blot analysis. RESULTS: In patients with an acute MI, plasma obtained from the coronary sinus after recanalization increased the mRNA expression of IL-1 beta and IL-8 compared with that of plasma before recanalization (median [quartiles] difference before vs. after recanalization: 34.5 [4, 137], p = 0.017, for IL-1 beta; 18.5 [4, 35], p = 0.032, for IL-8) and simultaneously obtained aortic plasma (median [quartiles] coronary sinus-aortic differences after recanalization: 45.5 [-3, 115], p = 0.021, for IL-1 beta; 16 [4, 52], p = 0.005, for IL-8). No induction of IL-6 and TNF-alpha expression could be observed. No changes found in the study patients were detectable in the control group. CONCLUSIONS: Plasma from the ischemic and reperfused heart stimulates the expression of IL-1 beta and IL-8 in leukocytes. Therefore, leukocyte-derived cytokines may contribute to the regulation of cardiac inflammatory responses in patients with an acute MI.

Adult↗
PubMed1997

Recovery of myocardial perfusion in acute myocardial infarction after successful balloon angioplasty and stent placement in the infarct-related coronary artery.

OBJECTIVES: This study sought to investigate changes in myocardial perfusion after direct percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (MI). BACKGROUND: After initially successful recanalization of the infarct-related artery, coronary perfusion may deteriorate as a result of reocclusion, distal embolization of platelet aggregates formed at the dilated plaque or microvascular reperfusion injury. This change could offset the benefit from early intervention. METHODS: The study included 19 patients in whom the infarct-related artery was successfully recanalized by PTCA with Palmaz-Schatz stent placement within 24 h after the onset of pain. Basal and papaverine-induced coronary blood flow were assessed by Doppler flow velocity measurements and quantitative coronary angiography. In addition, basal and adenosine-induced myocardial blood flow were measured by nitrogen-13 ammonia positron emission tomography (PET). RESULTS: Immediately after completion of the intervention, the average coronary flow reserve (CR) in the recanalized vessel was 1.56 +/- 0.51; it increased to 2.04 +/- 0.65 at 1 h (p = 0.013) and to 2.66 +/- 0.72 at 2 weeks after reperfusion (p = 0.008, n = 16). PET studies in 12 patients revealed that perfusion defect size and CR in the infarct region (2.19 +/- 0.89 vs. 2.33 +/- 0.86) did not change significantly between day 2 after recanalization and 2 weeks. However, we found significant (p < 0.03) increases in basal (by 26%) and adenosine-induced (by 40%) blood flow in the infarct region. CONCLUSIONS: Despite the persistence of a perfusion defect after successful recanalization of the occluded artery in acute MI, CR of the infarct region improves in most patients within 1 h and further improves within 2 weeks.

Adult↗
PubMed2001

[Long iliac artery occlusions: Feasibility, short- and mid-term outcome].

PURPOSE: It was the aim of the following study to determine the feasibility of the recanalization of long occlusions in iliac arteries and to establish its patency rate. MATERIAL AND METHODS: We retrospectively evaluated the data of 23 patients (15 male and 8 female) with occlusions of the iliac arteries with a mean length of 12 cm (range: 9-15 cm). The occlusions were situated either in the common iliac artery (CIA) (n = 3), in the external iliac artery (EIA) (n = 12) or in both CIA and EIA (n = 7). In one patient three vessels, the common femoral artery included, were involved. The recanalization procedure was performed with wire and catheter from retrograde and, in case of a failure, from antegrade in a cross-over technique. RESULTS: Recanalization succeeded in all patients. Technical success defined as residual stenosis < 30 % was seen in 20 of 23 patients. Early reocclusions were seen in four patients, in three of whom, the stent dilatation had been incomplete. Late reocclusions were observed in three patients, one of whom had already had early reocclusion. The reason was stent breakage in one, stent dehiscence in the second and restenosis in the third patient. All of the patients with reocclusion either early or late, had received covered stents. In four patients restenosis developed within 30 months: It was successfully treated by ballon dilatation or stent. Embolism during the recanalization procedure was observed in six patients. Embolism was observed on the ipsilateral side in five, and on the contralateral side in one patient. In each patient who had experienced embolism, balloon dilatation had been performed before stent implantation. CONCLUSION: 1) There is some evidence that the recanalization of long iliac artery occlusions is feasible. 2) The main reason for early and late reocclusions is either rest stenosis or restenosis. 3) Covered stents should only be used in selected cases. 4) Primary stenting is the treatment of choice in order to prevent embolism.

Adult↗
PubMed2004

[Long-term hemodynamic compromise in internal carotid artery dissection: quantitative blood volume flow evaluation using 2D Cine phase-contrast MR imaging].

PURPOSE: To use the magnetic resonance (MR) phase-contrast technique as a non-invasive method to determine blood volume flow in internal carotid artery (ICA) dissection, which has variable initial volume flow reduction and long term hemodynamic compromise. ICA dissection can lead to partial or complete recanalization or persistent occlusion, and strong clinical motivation exists for reliable assessment of the blood flow, in particular blood volume flow, in the carotid artery circulation after ICA dissection. MATERIALS AND METHODS: Blood volume flow in the carotid artery circulation was quantified in 28 patients with unilateral ICA dissection and 20 age-matched normal controls. Blood volume flow was measured in the ICAs and the common carotid arteries (CCAs) using 2D cine phase-contrast MR imaging. Final measurements were performed until after at least 6 months the hemodynamic compromise showed no changes by ultrasound and MRA. RESULTS: In long term follow up, 11/28 patients demonstrated remaining vessel occlusion, 10/28 partial and 7/28 complete recanalizations. Patients with ICA occlusion showed a significant contralateral volume flow increase (mean 56 %, p < 0.001) in comparison to normal controls. Patients with partial recanalization demonstrated volume flow rates between 24 ml/min and 188 ml/min in the dissected ICA and a less but significant (p < 0.001) increase in the contralateral volume flow. In patients with complete recanalization, normal volume flow conditions were found for both ICAs and CCAs. CONCLUSION: In ICA dissection, quantitative volume flow determination using 2D cine phase-contrast MR imaging is helpful in the initial assessment and long term follow-up of hemodynamic compromise. ICA dissection demonstrated a partial or complete recanalization in nearly (2/3) of the investigated patients and a persisting vessel occlusion in little more than (1/3). Compensatory contralateral increase in volume flow was found.

Adult↗
PubMed2002

Endovascular obliteration of saphenous reflux: a multicenter study.

OBJECTIVE: The objective of this study was to assess the differences in clinical outcomes in patients treated with endovenous saphenous vein obliteration with technical outcome of either complete occlusion (CO), near complete occlusion (NCO), defined as < or =5-cm segment of flow in treated vein, or recanalization, defined as >5-cm segment of flow in treated vein. STUDY DESIGN: The study was designed as a prospective registry with follow-up at intervals through 24 months. The subjects were 286 patients from 30 clinical sites with saphenous vein reflux as measured with duplex scanning. A total of 319 limb treatments were performed. Intervention included endovenous catheter obliteration of insufficient saphenous veins with temperature controlled radiofrequency heat, without high ligation of the saphenofemoral junction. The main outcome measures were status of occlusion of treated vein segments, presence of varicose veins and reflux, clinical symptoms scores, physician evaluation of procedure success, and patient satisfaction. RESULTS: At 12 months, 83.6% of treated limbs were classified as CO, 5.6% were categorized as NCO, and 10.8% were recanalized. At 24 months, 85.2% of treated veins were CO, 3.5% were NCO, and 11.3% were recanalized. Varicose veins were present in 95% of limbs before treatment. The presence of varicose veins in limbs with CO was 10.5%, 7.3%, 5.7%, and 8.3% at 1 week, 6 months, 12 months, and 24 months, respectively. The presence of varicose veins in NCO limbs was similar at each interval. Overall, 91.4% of 232 limbs followed to 12 months and 90.1% of 142 limbs at 24 months were free of saphenous vein reflux, regardless of technical outcome. Paresthesia was reported in 3.9% of limbs at 1 year and in 5.6% at 2 years. The pretreatment mean symptom severity score was 2.0. Mean posttreatment symptom scores decreased to 0.07, 0.0, and 0.50 for CO, NCO, and recanalized limbs, respectively, at 6 months. At 12 months, the mean scores were 0.06, 0.0, and 0.32 for CO, NCO, and recanalized limbs, respectively; at 24 months, the scores were at 0.10, 0.40, and 0.63. Patient satisfaction was achieved in 195 of 212 patients (92%) at 1 year and in 121 of 128 (94.5%) at 2 years. CONCLUSION: Endovenous vein obliteration without high ligation dramatically reduces the presence of varicosities and reflux and, when performed with the prescribed pull-back methodology, is comparable with vein stripping at 1 and 2 years. Patient satisfaction with the procedure is high at 2 years, regardless of technical outcome. At 2 years, the closure procedure is a viable alternative to stripping.

Female↗
PubMedDate not supplied

Diagnosis and thrombolytic therapy of acute basilar artery occlusion: a review.

Acute basilar artery (BA) occlusion is associated with an extremely high mortality. The pathogenesis in younger patients is usually embolism form cardiac sources or less frequently from vertebral artery dissection. Local atherothrombosis is more common in elderly patients. Differently to the carotid territory, for the vertebrobasilar territory there are no placebo controlled studies proving efficacy of thrombolytic treatment. Furthermore, neither the best route of administration nor the best fibrinolytic agent have been evaluated. Several uncontrolled series, however, indicate that intraarterial thrombolysis reduces mortality of patients with BA occlusion. Recanalization rates average 60% and are associated with occlusions of embolic etiology. Mortality with an average rate of 40-60% is significantly lower in the recanalization group in most series. Other independent variables affecting mortality are identified as length of obstruction, proximal BA occlusion, collateralization, high age, and initial poor clinical state. Time from onset of symptoms to start of intraarterial thrombolysis, however, is not associated with recanalization or mortality rate. This indicates that differently from thrombolytic treatment in the anterior circulation there is no fixed time window in BA thrombosis. Rate ofparenchymal hemorrhage seems to be lower with an average of 6% compared with systemic thrombolytic therapy in hemispheric stroke. Recanalization of the BA is clinically beneficial under certain circumstances only: (1) BA occlusion should affect only one segment; (2) an effective collateral supply is essential; and (3) the patient should not already be tetraplegic or comatose for a longer period of time. Clinical outcome and assessment of quality of life on follow-up of survivors with successful recanalization encourage thrombolysis in acute BA occlusions of embolic origin.

Acute Disease↗
PubMed1993

Diagnosis and treatment of proximal tubal obstruction by fluoroscopic transcervical fallopian tube catheterization.

The efficacy of fluoroscopic transcervical Fallopian tube catheterization in treating patients with proximal tubal obstruction was investigated. In 11 (15.9%) of the 69 patients who entered the study, patency of the proximal Fallopian tubes was shown by a pre-treatment hysterosalpingogram or an ostial selective salpingogram. Transcervical Fallopian tube catheterization attested to the success of recanalization in at least one of the obstructed tubes in 41 of our 58 patients (70.7%). Of 92 obstructed tubes, 56 (60.9%) were successfully recanalized. However, normal tubal visualization was possible in only 13 tubes (23.2%). Most of the recanalized tubes were considered to be peritubal adhesions (64.3%). Eight of 36 (22.2%) patients who had been successfully recanalized achieved pregnancies; 12 patients demonstrated normally appearing salpingograms after the procedure, and five (41.7%) had an intra-uterine pregnancy. Suspected peritubal adhesions were exhibited on post-operative salpingograms of 24 patients, one of whom had an intra-uterine pregnancy, while two had tubal pregnancies. Transcervical Fallopian tube catheterization is a simple and effective method for evaluating and treating proximal tubal obstruction. Most of the patients (70.7%) in whom recanalization was successful showed significant signs of distal tubal damage. This procedure can also be used to arrive at a prognosis regarding conception.

Adult↗
PubMed1991

True ablation of atheromatous plaques with laser energy. A phase I safety study.

A laser system coupling pulsed dye laser to a 2-mm fiberoptic catheter with incorporated angioscope has been developed for recanalization of occluded arteries. Nine patients with superficial femoral artery occlusions of 4.5 to 49 cm in length were operated on and the recanalized artery harvested for pathologic examination. There were two arterial perforations. The ease of recanalization was determined by plaque composition. Heavily calcified and yellow fibro-fatty lesions were rapidly removed. Smooth white fibrous lesions resisted laser ablation. Direct angioscopy often disclosed discontinuous areas of occlusion that were more susceptible to recanalization. These were not seen on preoperative arteriograms. Microscopic examination of the specimens showed a central core of ablation. There was no evidence of acute damage to the vessel wall, with intact internal elastic lamina demonstrated in the recanalized segments. It appears that fibrous lesions will require a different laser for ablation; however, the delivery/angioscope systems function satisfactorily.

Arteriosclerosis↗
PubMed1993

Treatment of refractory coronary occlusions with a new excimer laser catheter: preliminary clinical observations.

BACKGROUND: Total coronary occlusion is a frequent cause of procedural failure after coronary angioplasty, often because of the inability to recanalize the occluded segment with a conventional coronary guidewire. The novel excimer laser catheter described in this report contains a highly efficient, pulsed excimer laser guidewire designed to create a small channel within the occluded coronary segment. A preliminary report of the safety and efficacy of this excimer laser catheter is provided. METHODS: Ten patients with refractory coronary occlusions that could not be crossed by experienced operators using conventional guidewire techniques were treated using a novel laser catheter system. The laser catheter consisted of a densely packed, multiple fiber, helical guidewire measuring 0.020 inches (0.51 mm) in diameter, interfacing a 308 nm excimer laser system and delivering 70-80 mJ/mm2 of energy to the output surface. After the laser guidewire had been advanced to the occlusion site, laser energy was applied to ablate a channel as the wire was advanced through the occlusion. Once the occlusion had been recanalized, standard concentric laser or balloon angioplasty was performed. RESULTS: Complete recanalization was achieved in three total occlusions, and partial recanalization was established in a further three; thus, normal coronary perfusion was attained in six out of 10 patients after adjunct excimer laser or balloon angioplasty. The final minimum lumen diameter averaged 1.51 mm and the final residual stenosis diameter was 27%. In two patients the procedure was unsuccessful but without significant complications; two other patients developed limited coronary perforations without clinical sequelae. CONCLUSION: Refractory coronary occlusions were successfully recanalized in six out of 10 patients using a novel excimer laser catheter. Treatment failures in four patients were not associated with major complications, although limited coronary perforation occurred in two patients.

Angioplasty, Balloon, Coronary↗
PubMed1997

Different flow patterns in infarction of the middle cerebral artery.

Difficulties exist in distinguishing patients with currently recanalized mainstem occlusion of the middle cerebral artery (MCA) from branch occlusion. Thirty-five patients, 8 women and 27 men, at a mean age of 64 +/- 15 (standard deviation) years, with clinical signs of infarction in the MCA territory confirmed by computed tomography (CT), were evaluated by repeated clinical and transcranial Doppler sonography within 2 days of the event, 2 to 5 days later, and at 2 weeks after admission. The quotient MCA I/MCA C, derived to evaluate side differences, is defined as mean velocity (MV) in the MCA on the infarcted (I) side divided by MV in the MCA on the contralateral (C) side. Occlusion of the MCA was found in 13 of 35 patients at the first examination. A very high MV of 94 +/- 6 cm/sec with an abnormal turbulent flow pattern was found in 3 patients at the first examination, consistent with pseudostenosis after recanalization. The remaining 19 patients with a patent MCA had a lower MV in the affected side compared to the healthy side (37 +/- 15 and 54 +/- 20 cm/sec, p < 0.001). Five (38%) of 13 patients with acute MCA mainstem occlusions demonstrated recanalization at the second examination, within 1 week after the onset of stroke, with a MV of 82 +/- 44 cm/sec and pulsatility index (PI) of 0.68 +/- 0.38, which differed (p < 0.05) from the MV of 46 +/- 19 cm/sec and PI of 0.99 +/- 0.20 in the remainder. The MCA I/MCA C quotient revealed a difference (p < 0.01) between primarily patent vessels and recanalization at the second examination. A tendency to a better prognosis was found in originally patent or later recanalized vessels. Progression of neurological signs was noted in 3 (23%) of 13 patients with MCA occlusion and in 1 (4%) of 22 with nonoccluded MCAs.

Blood Flow Velocity↗
PubMedDate not supplied

A review of selective salpingography and fallopian tube catheterization.

Use of selective salpingography and fallopian tube recanalization has revolutionized the diagnosis and treatment of infertility. Selective salpingography, a diagnostic procedure in which the fallopian tube is directly opacified through a catheter placed in the tubal ostium, has been used since the late 1980s to differentiate spasm from true obstruction and to clarify discrepant findings from other tests. In fallopian tube recanalization, a catheter and guide wire system is used to clear proximal tubal obstructions. The recanalization procedure is simple for interventional radiologists to perform and is successfully completed in most patients (71%-92%). Pregnancy rates after the procedure have been variable, with an average rate of 30%. The combination of selective salpingography with fallopian tube recanalization has improved the overall management of infertility caused by tubal obstruction. The same catheterization technique used in fallopian tube recanalization is currently being explored for use in tubal sterilization.

Catheterization↗