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PubMed2003

Percutaneous treatment of complications occurring during hemodialysis graft recanalization.

INTRODUCTION/OBJECTIVE: To describe and evaluate percutaneous treatment methods of complications occurring during recanalization of thrombosed hemodialysis access grafts. METHODS AND MATERIALS: A retrospective review of 579 thrombosed hemodialysis access grafts revealed 48 complications occurring during urokinase thrombolysis (512) or mechanical thrombectomy (67). These include 12 venous or venous anastomotic ruptures not controlled by balloon tamponade, eight arterial emboli, 12 graft extravasations, seven small hematomas, four intragraft pseudointimal 'dissections', two incidents of pulmonary edema, one episode of intestinal angina, one procedural death, and one distant hematoma. RESULTS: Twelve cases of post angioplasty ruptures were treated with uncovered stents of which 10 resulted in graft salvage allowing successful hemodialysis. All arterial emboli were retrieved by Fogarty or embolectomy balloons. The 10/12 graft extravasations were successfully treated by digital compression while the procedure was completed and the graft flow was restored. Dissections were treated with prolonged Percutaneous Trasluminal Angioplasty (PTA) balloon inflation. Overall technical success was 39/48 (81%). Kaplan-Meier Primary and secondary patency rates were 72 and 78% at 30, 62 and 73% at 90 and 36 and 67% at 180 days, respectively. Secondary patency rates remained over 50% at 1 year. There were no additional complications caused by these maneuvers. DISCUSSIONS AND CONCLUSION: The majority of complications occurring during percutaneous thrombolysis/thrombectomy of thrombosed access grafts, can be treated at the same sitting allowing completion of the recanalization procedure and usage of the same access for hemodialysis.

Angioplasty↗
PubMed1987

Improvement of left ventricular contraction and relaxation synchronism after recanalization of chronic total coronary occlusion by angioplasty.

Twenty patients with a chronic total coronary artery occlusion were studied before and 1 to 48 months (mean 9) after successful recanalization by angioplasty and compared with a group of 20 normal subjects. Before angioplasty, 19 of these 20 patients had angina. Collateral vessels to the distal part of the occluded vessel were visible in all 20 patients. A previous myocardial infarction was documented in 14 patients (9 with a Q wave and 5 with a non-Q wave infarction). At the time of follow-up, three patients were symptomatic: one had unstable angina and two had a positive stress test. The follow-up angiogram showed a significant restenosis in six patients and reocclusion in two. The mean ejection fraction had improved slightly from 59 +/- 11% to 63 +/- 9% (p less than 0.05). Left ventricular wall motion synchronism was studied using two variables for 128 shortening segments: the "time of peak contraction" and the "time of peak relaxation," as obtained from biharmonic Fourier transformation for each segment. Their respective standard deviations reflect the synchronism of contraction and relaxation. The mean standard deviations of the two variables expressed in degrees of one cardiac cycle (360 degrees) were respectively: 5.5 +/- 0.4 degrees for the time of peak contraction and 6.0 +/- 0.5 degrees for the time of peak relaxation in the 20 normal subjects, 11.7 +/- 1.7 degrees and 23.0 +/- 3.0 degrees before recanalization and 9.6 +/- 1.8 degrees and 12.5 +/- 2.2 degrees at follow-up in the group of 20 patients. These values were significantly higher (p less than 0.05) in the patients than in the normal group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1998

The pattern of alteration in flow velocity in the recanalized artery is related to left ventricular recovery in patients with acute infarction and successful direct balloon angioplasty.

OBJECTIVES: We evaluated the relationship between alterations in coronary flow velocity during the acute phase of acute myocardial infarction (AMI) and the recovery of left ventricular wall motion in patients who underwent successful primary angioplasty. BACKGROUND: The status of the coronary microcirculation is the major determinant of the prognosis of patients who have had successful reperfusion after AMI. Animal studies have shown that dynamic changes in regional flow are associated with the extent of infarction. Evaluation of alterations in coronary flow velocity in infarcted arteries may provide information about microcirculatory damage. METHODS: Flow velocity of the distal anterior descending artery was continuously monitored with the use of a Doppler guide wire immediately after recanalization for 18 +/- 4 h in 19 patients who underwent successful primary angioplasty after anterior AMI. Subjects were divided into two groups on the basis of the time course of alterations in average peak velocity (APV). Group D consisted of patients who had progressive decreases in APV through the next day (n = 9), and Group I comprised patients with an increase in APV after a transient decline (n = 10). Ejection fraction (EF) and regional wall motion (RWM) were assessed by left ventriculography performed on admission and at discharge. RESULTS: The APV at the end of monitoring was greater in group I than in group D. In group I, EF and RWM were significantly improved at discharge. The change in EF was greater in group I than in group D (17 +/- 9% vs. 4 +/- 9%, p = 0.007), as was the change in RWM (0.96 +/- 0.23 vs. 0.13 +/- 0.36 SD/chord, p < 0.0001). CONCLUSIONS: The alteration in flow velocity in recanalized infarcted arteries is related to left ventricular recovery. A progressive decrease in velocity after angioplasty implies no reflow, which is associated with a poor recovery of left ventricular function. Reperfusion injury may account in part for this phenomenon.

Aged↗
PubMed1999

A randomized trial of elective stenting after balloon recanalization of chronic total occlusions.

OBJECTIVES: The aim of this study was to assess the role of Wiktor stent implantation after recanalization of chronic total coronary occlusions with regard to the clinical and angiographic outcome after six months. BACKGROUND: Beside the common use of stents in clinical practice, the number of stent indications proven by randomized trials is still limited. METHODS: Eighty-five patients with a thrombolysis in myocardial infarction grade 0 chronic coronary occlusion were examined. After standard balloon angioplasty, the patients were randomly assigned to stent implantation, or percutaneous transluminal coronary angioplasty (PTCA) alone (no further intervention). Quantitative coronary angiography was performed at baseline and after six months. RESULTS: The minimal lumen diameter did not differ immediately after recanalization (stent group 1.61 +/- 0.30 mm vs. PTCA group 1.65 +/- 0.36 mm), and increased after stent implantation to 2.51 +/- 0.41 mm. After six months, the stent group still had a significantly greater lumen (1.57 +/- 0.59 vs. 1.06 +/- 0.90 mm; p < 0.01) and a significantly lower restenosis and reocclusion rate (32% and 3%) compared with the PTCA group (64% and 24%); restenosis analysis according to treatment was 72% (PTCA) versus 29% (stent, p < 0.01). Late loss was equal in both groups. At follow-up, the stent patients had a better angina class (p < 0.01), and fewer cardiac events (p < 0.03). A meta-analysis including this trial and three other controlled trials with the Palmaz-Schatz stent showed concordant results. CONCLUSIONS: Stent implantation after reopening of a chronic total occlusion provides a better angiographic result, corresponding to a better clinical outcome with fewer recurrence of symptoms and reinterventions after six months.

Adult↗
PubMed2002

Dissolution of tungsten coils does not produce systemic toxicity, but leads to elevated levels of tungsten in the serum and recanalization of the previously occluded vessel.

AIM: To evaluate the failure of mechanically detachable spirals produced from tungsten (MDS, Balt, Montmorency, France) and the toxicity of elevated levels of tungsten in the serum subsequent to their implantation. METHODS: We reviewed findings in 21 patients in whom tungsten coils had been used to occlude pathologic vessels, aneurysms and fistulas between 1996 and 1999. We achieved clinical follow-up, and measured renal and hepatic function, in 14 of the 21 patients. RESULTS: Decreased radiopacity of the coils was observed in 9 of 13 patients who had follow-up fluoroscopy during repeat cardiac catheterization. Repeat angiography of the vessel occluded by the coil was performed in 7 patients, 5 of whom showed recanalization. Levels of tungsten in the serum were analyzed 6 to 35 months after implantation of coils in 8 patients. The mean concentration was 6.43 micrograms/l, with a range from 2 to 14.4 micrograms/l, normal values being less than 0.2 microgram/l. CONCLUSION: Tungsten coils may dissolve over time and lead to markedly elevated levels of tungsten in the serum, with recanalization of previously occluded vessels. Despite lack of clinical and laboratory data in patients with elevated levels of tungsten in the serum, our study suggests that the clinical use of mechanically detachable coils produced from tungsten should no longer be recommended.

Adolescent↗
PubMed2006

Patency or recanalization of the arterial duct after surgical double ligation and transfixion.

OBJECTIVE: The frequency of residual shunting or recanalization was investigated in patients in whom a persistently patent arterial duct had been doubly ligated and transfixed during surgical closure. METHODS: We investigated in retrospective fashion for any residual shunting 325 patients who, between January 1990 and December 2004, had undergone surgical double ligation and transfixion of a persistently patent arterial duct. Shunting was discovered in 10 patients, of whom four male and six female. RESULTS: Of those with residual shunting. 4 patients had initially exhibited only persistent patency of the duct, while the other 6 had associated mild cardiac lesions. The mean age at operation was 5.5 years, with a range from 0.5 to 17.9 years. Postoperatively, the mean period for detecting the residual shunt was 22.8 months, with a range from 2 days to 72 months. The frequency of residual shunting amongst our patients, therefore, was 3.1%. We detected the residual shunt by colour-flow Doppler mapping in all patients, although a continuous murmur was heard in only one patient on physical examination. CONCLUSION: Our findings suggest that clinical sensitivity of detecting residual shunting subsequent to surgical closure of the persistently patent arterial duct is low, and hence that colour-flow Doppler interrogation should be a part of follow up. Residual shunting, or recanalization, may occur even after double ligation and transfixion of the duct. Since the residual flow may emerge after months, or even years, follow-up is needed for longer periods.

Adolescent↗
PubMed2002

Isolated esophageal atresia with spontaneous recanalization: case report.

Isolated esophageal atresia is characterized by a long segment between the 2 esophageal pouches. The authors describe a case of pure esophageal atresia that showed spontaneous recanalization in the waiting period for primary esophageal anastomosis. Regurgitation of gastrostomy formula surprisingly was seen in her mouth. The patency of the esophagus was confirmed with thoracic computed tomography (CT) and an esophagogram. A strictured area in the proximal upper third of the esophagus was managed with baloon dilatation. She was discharged in normal condition, feeding by mouth, and with a normal esophagogram. This interesting event led us to speculate about a different type of pure esophageal atresia with the feasibility of the ends recanalizing after some events such as inflammation. This could be the subtype II5 of type 2 in Kluth's atlas of esophageal atresia in which they described 2 blind esophageal ends and a cyst occupying the intervening space. Another speculation about this subject is the presence of double membranes associated with esophageal atresia with a normal outer appearance of the esophagus as was first described by A. F. van Loosbroek.

Esophageal Atresia↗
PubMed2001

Microwave recanalization: thermal effects with nitinol and stainless-steel stents.

BACKGROUND AND STUDY AIMS: A previous study we conducted evaluated the thermal effects of microwave irradiation when attempting recanalization of a nitinol stent occluded by tumor ingrowth. The present study evaluates the thermal effects of microwave irradiation on different stents in vitro. METHODS: The thermal response to microwave energy was evaluated in a muscle-equivalent phantom containing a nitinol (Accuflex) or stainless-steel stent (Wallstent). The phantom temperature was monitored continuously at different distances from an electrode, with either stent type in place. The tip of the electrode was either in contact with the stent or not in contact with it. RESULTS: The steel stent showed a smaller temperature increase than nitinol at 2 mm from the electrode. Without electrode contact, the stents did not differ significantly during the first 40s of irradiation. The stents did not differ significantly with regard to temperatures further from the electrode. When the electrode was in contact with the stent, the rise in temperature was significantly greater with the stainless-steel stent than with the nitinol one, but the phantom temperature did not exceed 45 degrees C with either of the stents. CONCLUSIONS: In patients with a Wallstent stainless-steel stent, microwave coagulation therapy to recanalize stent occlusions appears to be feasible in the same conditions as with an Accuflex nitinol stent.

Alloys↗
PubMed2002

[Intravascular ultrasound thrombolysis for recanalization of peripheral arteries: evaluation of an in vitro model and results of a pilot-study].

OBJECTIVES: To evaluate the effectiveness of ultrasound thrombolysis in vitro in comparison with thrombectomy, and in vivo as a pilot-study for the treatment of thrombotic occlusions of peripheral arteries. METHODS: Under standardized conditions, one-day-old and five-day-old thrombi of whole blood, thrombin-induced thrombi and old organized thrombi of human blood were treated with ultrasound thrombolysis and Amplatz thrombectomy device (ATD). Four patients with arterial occlusive disease of Fontaine stage IIb-III underwent intraarterial ultrasound-thrombolysis, applied to long segmental occlusions of the superficial femoral or iliac artery ranging in duration from three days to one year. RESULTS: The weight of the thrombi after ultrasound thrombolysis was 1.5 g +/- 0.53 (ATD: 0 g) compared to 3.65 g +/- 0.34 without treatment, with more weight reduction in five-day-old thrombi than in one-day-old thrombi. In vivo, partial recanalization was achieved in a three-day-old femoral occlusion. There was no effect in the other three patients. Urokinase thrombolysis with subsequent PTA and stenting resulted in complete recanalization in three patients. CONCLUSIONS: Ultrasound thrombolysis in vitro was significantly less effective than ATD. The results of ultrasound thrombolysis were influenced by the age of the thrombus and its in vitro formation. Intravascular ultrasound thrombolysis alone was insufficient to treat occluded peripheral arteries in vivo.

Aged↗
PubMed1994

[Retrograde catheter recanalization of long-range occlusion of the superficial femoral artery].

In a prospective study between March 1992 and October 1993, 50 consecutive patients (47 men, three women; mean age 59.7 [42-73] years) with a total of 52 occlusions of the superficial femoral artery underwent retrograde recanalization via the popliteal artery. The patients were in clinical stage IIa (n = 7), IIb (n = 38) or III (n = 5). The mean Doppler ratio (ankle/arm) was 0.51 +/- 0.14, mean length of occlusion 19 +/- 9 [4-40] cm. Popliteal puncture was successful in all patients but one. The occlusion was passed by guide-wire in 38, subsequently by balloon catheter in 37. Additional laser angioplasty had to be performed in five patients, while stent implantation was necessary in another five. 35 of 52 vessels (in 33 patients) remained open and free of significant stenosis after the procedure. The mean ankle/arm Doppler ratio was 0.5 +/- 0.13 immediately before the angioplasty, 0.72 +/- 0.17 (P < 0.05) immediately afterwards. There were no complications ascribable to the technique except in two cases in which an asymptomatic arteriovenous fistula developed. These results indicate that retrograde recanalization of the superficial femoral artery is a relatively reliable and successful catheter technique in patients who would otherwise have to be treated by surgery.

Adult↗
PubMed1988

[Opening of chronic coronary artery occlusions with a recanalization catheter].

Percutaneous transluminal angioplasty for recanalization was attempted for 44 chronic coronary arterial occlusions in 41 patients (two occluded vessels in three patients). In 11 instances the occlusion could be passed with a guide-wire. In the other 33 this was not possible. In 25 of them a 3, 4 or 5 F recanalization catheter, its end tapered to 2 or 3 F, was used. In this way re-opening was possible in 17 cases (68%). The catheter made it possible to splint or stiffen the guidewire to keep it straight, superselectively inject contrast medium, measure the pressure distal to the occlusion, and gradually bougie-like enlarge the resulting subtotal stenosis. A total of 28 of 44 coronary occlusions were re-opened (64%). All these patients were functionally improved. At subsequent angiography (a mean of 3.6 months later) 22 of 25 vessels had remained open, but ten had narrowed and three had become re-occluded.

Adult↗
PubMed1983

[Recanalization of an acutely occluded coronary bypass: combined local and systemic streptokinase administration].

Renewed severe angina occurred in a 57-year-old patient 14 months after a quadruple aortocoronary graft. Angiography demonstrated acute occlusion of a posterolateral graft. After 120 minutes of local streptokinase infusion (2000 IU/min) there was partial recanalization, with complete thrombolysis and graft recanalization after subsequent intravenous streptokinase infusion (30 000 IU/min for 90 minutes). Contrary to the situation in early postoperative graft thrombosis, acute late occlusion can be successfully lysed without increased risk of bleeding (haemopericardium).

Coronary Angiography↗
PubMed1983

[Direct recanalization with transluminal angioplasty in acute myocardial infarct].

Treatment of acute cardiac infarction by invasive recanalization permits simultaneous removal of stenosis and occlusion: this is achieved by direct transluminal angioplasty, passage of the occlusion with the folded balloon catheter and dilatation of the stenosis. In a 42-year-old patient with anterior wall infarction and cardiogenic shock a high subtotal occlusion of the interventricular anterior branch with a thrombus beyond the 99% occlusion was seen. Due to the life-threatening state of the patient the narrowing was directly passed and relieved by dilatation. The patient survived the severe cardiogenic shock. In a second patient with posterior wall infarction complete occlusion of the right coronary artery occurred. A balloon catheter was passed without prior manipulation of the guide wire, and the occlusion was passed without difficulty. After dilatation, only moderate narrowing could be observed. Both cases demonstrate that recanalization and simultaneous removal of stenosis is possible when transluminal angioplasty is used from the beginning.

Adult↗
PubMed2004

Late coronary artery recanalization effects on left ventricular remodelling and contractility by magnetic resonance imaging.

AIMS: To assess the recanalization effects of post-myocardial infarction (MI) on left ventricular (LV) remodelling and contractility in relation to conservative therapy. METHODS AND RESULTS: Thirty-six patients with occluded infarct-related artery between 12 h and 14 days post-anterior MI were randomized to percutaneous coronary intervention (PCI group) or conservative therapy (no-PCI group). Magnetic resonance imaging was performed at enrollment and after 6 months. The left ventricle was divided into infarct, adjacent, and remote segments. There was no difference in relation to LV volume between groups at the 6 month follow-up. Change in LV ejection fraction was favourable to the PCI group: 5.00% vs. -0.76%, P=0.012. Change in circumferential shortening (Ecc) of the remote segments in the PCI group was significantly better than in the no-PCI group: -1.67+/-6.30% vs. 0.29+/-6.02%, P<0.001. Infarct size and LV mass were similar between groups. CONCLUSIONS: Late recanalization improved LV ejection fraction and myocardial contractility in late follow-up, but did not change the ventricular volumes. Improvement in the left ventricle global and regional contractility may benefit the long-term outcome in post-MI patients with sustained patency of the infarct-related artery.

Angioplasty, Balloon, Coronary↗
PubMed1990

Delayed improvement of myocardial function after recanalization of a chronic coronary occlusion in a patient with intractable heart failure.

This case report describes the delayed improvement of left ventricular function by recanalization of an occluded coronary artery in a patient with intractable heart failure and three-vessel disease. The left anterior descending coronary artery was occluded distal to the first septal branch, the dominant right coronary artery had a diameter stenosis of 70-80% in its middle part, and the circumflex artery a proximal stenosis of 50%. Ventriculography revealed globally depressed left ventricular function with an ejection fraction of 16%. Successful recanalization and angioplasty of the occluded coronary artery resulted in a slow improvement of left ventricular function. Ultimate recovery of systolic performance (increase of ejection fraction from 16% to 48-51%) required more than half a year. It is speculated that stunned myocardium following chronic ischaemia is a consequence of vascular dysfunction.

Angioplasty, Balloon, Coronary↗
PubMed1992

Fallopian tube recanalization by selective salpingography: an alternative to more invasive techniques?

Selective salpingography was used in a total of 64 patients, engaged in evaluation for infertility and in whom standard hysterograms showed no tubal passage of contrast medium. Fallopian tube catheterization was successful in 92% of the cases; a peritoneal spill of contrast medium was obtained in 74% of the cases by manual injection. Recanalization of an obstructed oviduct was successful in 61% of the cases. Thus, after the procedure, 82% of the patients had at least one patent tube. We conclude that selective tubal catheterization, and recanalization when needed, should be included in the therapeutic procedures for tubal infertility, prior to in-vitro fertilization or tubal microsurgery.

Adult↗
PubMed1999

Percutaneous endoscopic recanalization of the catheter: a new technique of proximal shunt revision.

OBJECTIVE: Proximal ventricular catheter obstruction by the choroid plexus is a frequent occurrence in children with shunted hydrocephalus. In some cases, the flow is obstructed owing to membranous occlusion by a small amount of tissue. It has been shown that only a few of the multiple catheter openings need be patent to maintain adequate shunt function. Recent advances in technology have improved our ability to perform intraluminal endoscopic catheter dissection and minimize the morbidity associated with shunt maintenance. METHODS: Percutaneous endoscopic shunt recanalization was performed in 20 cases (18 children) under institutional review board study protocol. The mean age was 32 months, and all children had signs and symptoms of shunt malfunction, confirmed by computed tomography and magnetic resonance imaging and verified by shunt taps. Under aseptic conditions in the operating room, the Rickham reservoir was entered with a 16-gauge intravenous catheter, and the obstruction was visualized with a fiber endoscope (0.5-0.8 mm). Intraluminal dissection using electrocautery was performed with endoscopic guidance to visualize the catheter and flushing of the valve. RESULTS: At a mean follow-up time of 20 months (range, 15-29 mo), the children are doing well, with computed tomographic and magnetic resonance imaging confirmation of adequate ventricular decompression in the 17 successful cases (85%). There were three failures in the study, necessitating a standard open shunt revision. CONCLUSION: The percutaneous endoscopic shunt recanalization procedure can be used successfully to treat proximal shunt malfunction.

Cerebrospinal Fluid Shunts↗
PubMed2002

New grading system for angiographic evaluation of arterial occlusions and recanalization response to intra-arterial thrombolysis in acute ischemic stroke.

OBJECTIVE: The Thrombolysis in Myocardial Infarction (TIMI) grading scheme and other classification systems are limited because they do not account for occlusion location or collateral circulation. A new scheme for angiographic classification of arterial occlusion and recanalization response to intra-arterial thrombolysis in acute ischemic stroke was designed because of limitations in existing grading systems. METHODS: The proposed scheme assigns a score from 0 to 5 on the basis of occlusion site and collateral supply. The pre- and post-thrombolysis angiograms of 15 patients with acute ischemic stroke were independently graded by three neurointerventionists according to TIMI perfusion grade (0-3), a grading scheme developed by Mori et al. (Mori E, Tabuchi M, Yoshida T, Yamadori A: Intracarotid urokinase with thromboembolic occlusion of the middle cerebral artery. Stroke 19:802-812, 1988) (0-4), and the proposed scheme (0-5); and interobserver agreement was assessed. The effect of severity of initial arterial occlusion on outcomes of good recovery (National Institutes of Health Stroke Scale score of < or =4) or death at 7 days after thrombolysis according to the proposed and TIMI grading schemes was also assessed in 60 patients with acute ischemic stroke. Multivariate analyses were performed to assess these relationships after adjusting for patient age, sex, time interval between symptom onset and treatment, and thrombolytic agent used. RESULTS: Interobserver agreement was higher for pre- and posttreatment grading of angiographic images using the new classification scheme (kappa = 0.73) than with either TIMI perfusion grade (kappa = 0.68) or Mori et al. grade (kappa = 0.68). The proposed grading scheme was inversely associated with good recovery at 7 days (odds ratio, 0.4; 95% confidence interval, 0.2-0.9) and directly associated with 7-day mortality (odds ratio, 2.0; 95% confidence interval, 1.1-3.6) after treatment. Initial TIMI grade did not correlate with either good recovery or death at 7 days. An inverse trend was observed between initial severity of angiographic occlusion as determined by the proposed scheme and complete recanalization after treatment (odds ratio, 0.6; 95% confidence interval, 0.4-1.02). CONCLUSION: Application of the new classification scheme for assessing pretreatment occlusion and response to intra-arterial thrombolysis resulted in high interobserver agreement and correlated with 7-day outcomes. The six grades used in this scheme allowed precise angiographic evaluation of perfusion changes.

Aged↗