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The kidney can remain viable even in anuric renal failure. Arteriography and hippuran scanning were not helpful in determining renal viability in a 41-year-old man. Interestingly, a high-grade stenotic lesion of the renal artery had resolved during a three-month period probably by recanalization. This illustrates that conservative management may result in preservation of viable renal parenchyma.
Chronic total occlusion remains a relative contraindication and the main cause of failure of coronary angioplasty. Previously available hydrophilic guidewires had numerous limitations. The Crosswire is a new 0.014" hydrophilic nitinol guidewire which can be accommodated by very-low-profile balloon catheters and has a shapeable and highly radiopaque platinum-iridium coiled tip. This guidewire was used in 55 patients with 56 chronic coronary occlusions in which recanalization by conventional guidewires had failed. Clinical success was 79%. Coronary perforation occurred in two cases, one of them requiring pericardiocentesis for tamponade. These results illustrate the usefulness of this new guidewire in the treatment of chronic total occlusions.
Treatment of subclavian artery stenosis by percutaneous balloon angioplasty and adjunctive stent placement was shown to be safe and efficacious, but it may be limited in tight stenoses and long occlusions. We describe the case of a patient who experienced progressive angina pectoris associated with signs of cerebrovertebral insufficiency 9 yr after bypass surgery, including left internal mammary artery (LIMA) grafting to the left anterior descending coronary artery. Angiography showed reversed flow through the LIMA graft into the subclavian artery and a 4-cm occlusion beginning at the origin of the left subclavian artery, representing a rare coronary-subclavian steal syndrome. After a conventional approach failed, recanalization was performed successfully using laser guide wire angioplasty with adjunctive stent placement in a combined radial and femoral approach.
The current status of new techniques for percutaneous arterial recanalization, including laser, thermal and mechanical angioplasty techniques, is described. The reported results, potential advantages and possible future developments are discussed.
An unusually prolonged course of recovery of severely impaired left ventricular (LV) function (EF 32%) was observed in a patient after recanalization of a chronically occluded LAD. Despite persistent vessel patency, LV function remained depressed for almost 2 years after the percutaneous transluminal coronary angioplasty until complete recovery (EF 82%) could be observed. The possibility of a delayed recovery should be considered when assessing new therapeutic strategies to improve LV function of chronically ischemic myocardium.
Congenital isolated local atresia of the aortic isthmus is anatomically similar and morphogenetically related to congenital coarctation of the aorta and was encountered in 4 out of 26 consecutive adult patients selected for coarctation angioplasty at our center. Anterograde recanalization of the atresia was safely and successfully accomplished in all four patients, using a brachial approach. Balloon dilation in the four patients, with ancillary stent implantation in one patient, resulted in reduction of translesion gradient from 84 +/- 11 mm Hg to 9 +/- 7 mm Hg without complications. Angiography in the three non-stented patients after a mean follow-up of 13 months showed no evidence of restenosis, dissection or aneurysm formation, though one patient had mild dilatation of the posterior aspect of the aortic isthmus. The clinical presentation of patients with isolated local aortic atresia, and their short- to mid-term response to percutaneous treatment, is similar to that of patients with isolated severe coarctation of aorta.
Recanalization of two occluded posterior tibial arteries was successfully achieved by utilizing a retrograde approach via a posterior tibial artery cutdown at the level of the ankle. Both cases were previously unsuccessfully attempted by using an antegrade approach. Thus, the choice of access vessel (arterial entry site) becomes a crucial determinant of angioplasty success.
To diminish the restenosis rate after successful recanalization of chronic total coronary occlusion, we have implanted the Palmaz-Schatz stent in 6 patients. All procedures were successfully done without major complications. The angiographic follow-up at 6 months showed restenosis in one asymptomatic patient who had had 2 stents implanted. Five other patients had no evidence of restenosis.
A novel radiofrequency ablative system (40 msec-train pulses with twenty 200 msec pulses at the carrier frequency of 750 KHz and 1 Hz repetition rate) aimed at recanalizing totally occluded peripheral arteries was investigated by means of in vitro tissue ablation from human postmortem arterial wall samples. The samples were submitted to irradiation with a guidewire 150 cm long, maximum diameter of ceramic tip 0.033 inch positioned perpendicular to the tissue surface in saline, contrast medium or blood using varying generator power. Ablation efficacy was determined as the depth of vaporization per pulse delivered. Electrical current for the train duration was measured as voltage at the 1 ohm-resistor. In saline, the ablation efficacy increased from 8 to 65 microns/pulse with generator power increasing from 11 W to 27.5 W. There was no significant difference in the ablation efficacy between saline and blood. In contrast medium, the ablation efficacy was significantly lower. For the same generator power, the electrical current varied during the ablation procedure from 1.3 +/- 0.2 A at the beginning of the procedure to 1.1 +/- 0.2 A after the first pulses and to 2.0 A before artery wall perforation occurred. Neither tissue ablation nor current variations were observed when radiofrequency energy was emitted on calcified tissue. The diameter of craters was 0.89 +/- 0.1 mm (range: 0.85-0.96 mm). No major thermal injury such as carbonization or charring was observed.(ABSTRACT TRUNCATED AT 250 WORDS)
Five patients undergoing distal saphenous vein bypass had an attempt at intraoperative laser vaporization of a proximal coronary stenosis. Laser treatment of three patients was technically successful. One patient's successfully treated native vessel was competing with the graft at angiographic restudy 25 days after the procedure. This first human intraoperative laser recanalization trial generated questions regarding the energy source, power parameters, and catheter modifications required for satisfactory clinical laser therapy. The trial is directing future experiments toward more efficient and complete laser vaporization of atherosclerotic plaques in the human coronary vasculature.
A variety of techniques has been used to relieve the obstructive symptoms of pyloric stenosis. Endoscopic dilatation using hydrostatic balloon dilators, multiple-diameter bougies, and electrocautery with a sphincterotome have been described. The neodymium yttrium aluminum garnet laser also has been used, with both noncontact and contact probes. We describe a new technique using a guidewire-directed contact probe for laser recanalization of pyloric stenosis in a patient with radiation-induced gastric outlet obstruction.
The aim of this study was to evaluate whether streptokinase (SK) may produce beneficial effects at the level of microvascular circulation in addition to coronary recanalization. Twenty mongrel dogs weighing 28.4 +/- 4.6 kg were randomized to receive SK (16,000-72,000 U/kg) or 20 ml saline (control) in an open-chest anterior descending artery occlusion (3 h) and reperfusion (2 h) model. Myocardial blood flow was measured by the radioactive microsphere technique and the state of microvascular circulation (red blood cell containing capillary counts and tissue red blood cell content) was evaluated in the infarcted subendocardial zone using computerized image analysis. The percentage (mean +/- SE) of cell-containing vessels normalized to nonischemic control areas was 166.5 +/- 7.5 in SK-treated infarcts while in untreated control infarcts it was more variable (130.0 +/- 15.6%) (2P > 0.1). The red blood cell content of infarcts treated with 2.0 megaunits SK was 3.9 +/- 0.6% compared with 6.7 +/- 0.9% in untreated control infarcts (2P = 0.029). Plasma viscosity was slightly reduced in SK-treated dogs (2P = 0.05), but no significant changes in blood fibrinogen, hemoglobin, blood flow, and high energy phosphate levels between control and SK-treated infarcts were observed. SK reduces congestion and results in more even reperfusion of the microvasculature in severely ischemic myocardium to which blood flow has been restored. This effect may be beneficial in the salvage and healing of clinical infarctions.
Vascular recanalizing techniques only recently became methods of some clinical importance. Angioplasty of the subclavian artery in cases with subclavian steal syndrome has now been performed in so many instances that it can be judged safe. Angioplasty at the origin of the vertebral artery has not yet been performed in as many cases. However, even there this method is obviously less hazardous than surgery. Local intraarterial fibrinolytic therapy is the only therapy providing some success in progressive stroke from vertebrobasilar thrombosis. In contrast to the vertebrobasilar territory local fibrinolytic therapy within the carotid territory has to be strictly limited to some special indications.
This report details the clinical course and angiographic findings of a patient with intermittent vertebrobasilar insufficiency. Recanalization of the basilar artery was demonstrated during anticoagulant therapy. A review of the literature failed to disclose a previous report of this occurrence.
We present the case of a 42-year-old female, who suffered an embolic occlusion of the right middle cerebral artery (MCA). Recanalization was achieved with tissue plasminogen activator (t-PA) within 7 h after onset of stroke. Post-t-PA infusion angiographic and CT examinations revealed fragmentation of the thrombus and a small putaminal haemorrhage associated with early reperfusion of the MCA. No clinical deterioration was observed and complete recovery occurred within 10 days.
A 70-year-old woman suffered paresis of the left hand with dysaesthesia of the head lasting about 12 hours. The Doppler-flow study and duplex scan of the carotid arteries performed 14 days later showed an occluded right internal carotid artery. She refused angiography. However, 7 days later she was willing to undergo further investigation. This time the Doppler flow study and duplex scan demonstrated regular flow without stenosis, which suggested spontaneous recanalization of the formerly occluded right internal carotid artery.
We studied 7 patients with internal carotid occlusion following spontaneous arterial dissection. All presented strokes, in one associated with Horner's syndrome. The doppler examination showed carotid occlusion, but only angiography established the diagnosis of vascular disease. Spontaneous recanalization was observed in 6 cases, treated only by antiplatelet drugs.
A 47-year-old woman presented with disabling right arm claudication 10 weeks after Sones cardiac catheterization via a brachial artery cut-down. A technique of extraluminal recanalization of the brachial artery occlusion, used to treat this patient, is described.