Vessel sizing wire: accurate vessel measurement using digital subtraction arteriography

A simple method of measuring vessel diameters using intraarterial digital subtraction angiography has been designed. With a catheter in place within the vessel of interest, a segmented guide wire with known dimensions is advanced into the catheter in the area to be measured. We have used the method successfully for balloon angioplasty as well as balloon embolization.     

Intravascular MR imaging-guided balloon angioplasty with an MR imaging guide wire: feasibility study in rabbits

PURPOSE: To develop a technique for intravascular magnetic resonance (MR)-guided balloon angioplasty with use of an MR imaging guide wire. MATERIALS AND METHODS: An MR imaging guide wire (0.6-mm loopless antenna) that could be placed within a balloon catheter was manufactured. The guide wire was expected to function as either an MR receiver probe in real-time MR imaging or a guide wire for use with interventional devices. Laparotomy was performed in eight rabbits, and a dilatable stenosis was created at the upper abdominal aorta. Balloon angioplasty, validated at pre- and postoperative MR aortography with renal contrast enhancement was performed by using a 1.5-T MR unit with a fast spoiled gradient-echo pulse sequence, short repetition and echo times, and a rate of three frames per second. RESULTS: During MR tracking, the entire length of the MR imaging guide wire was always visible as a band of high signal intensity. In all cases, the MR imaging guide wires were passed through the aortic stenoses dilated by means of balloon inflation. Before balloon angioplasty, flow in the aorta distal to the stenosis was decreased, which caused mild contrast enhancement in each kidney. After balloon angioplasty, distal flow was restored, resulting in substantial renal enhancement. CONCLUSION: The MR imaging guide wire is a potential tool for use in endovascular interventional MR imaging.     

Guide-wire reinforcement and lengthening with coaxial locking guide wires: the crimping technique

The authors developed a technique to increase the size of a guide wire and permit single-step placement of catheters and large sheath systems over previously inserted small-caliber guide wires. The technique involves compression of metal cannula against a smaller in-dwelling wire or inner cannula. It has been used successfully during laser-assisted balloon angioplasty and percutaneous nephrolithotomy.     

Design and testing of a high-flow autoperfusion catheter: an experimental study.

An autoperfusion catheter is similar to an angioplasty balloon catheter with side holes in the guide-wire lumen proximal to the balloon. When the balloon of the autoperfusion catheter is deployed and inflated in an artery, the guide wire is removed, and the hub of the guide-wire lumen is capped. The catheter then allows passive distal perfusion by using ambient pressure to drive blood into the guide-wire lumen, through the balloon, and out the end hole. This article discusses the requirements and constraints of a high-flow autoperfusion catheter, summarizes attempts to modify standard angioplasty catheters for use as an autoperfusion catheter, and describes the design and testing of a custom autoperfusion catheter capable of delivering approximately 3 mL/sec at physiologic pressures. In a model of canine acute renal artery occlusion lasting 90 minutes, the custom autoperfusion catheter provided marked protection from acute tubular necrosis compared with conventional percutaneous transluminal angioplasty catheters. The authors conclude that the high-flow autoperfusion catheter may be useful as a temporary stent in cases of rupture, dissection, or penetrating wounds involving large arteries.     

Pull-through approach to percutaneous angioplasty of totally occluded common iliac arteries

A method has been developed to increase the probability of success of percutaneous transluminal balloon angioplasty of total occlusions of the common iliac artery when conventional methods have failed. In 10 patients with a totally obstructed iliac artery, a guide wire was passed through a catheter placed from the contralateral side around the aortic bifurcation and antegrade through the total obstruction. The end of the wire was either snared by a retrieval basket or guided through a sheath in the ipsilateral common femoral artery, thus providing a firmly anchored pathway for subsequent manipulations. Balloons were then inserted retrograde through both common femoral arteries and dilated. In the first five patients, ipsilateral retrograde passage of a guide wire had failed despite multiple attempts with a variety of devices. In the other five patients, the contralateral antegrade approach was used initially. The new method was successful in all 10 patients with totally obstructed common iliac arteries.     

Wire-directed detachable balloon. Work in progress

A new silicone detachable balloon has two self-sealing valves. The proximal valve grips the catheter tip, and the distal valve allows a guide wire to pass through. The balloon is advanced over the guide wire. Detachment is performed after the wire is withdrawn. Five balloons were successfully placed in the intended arteries and veins of three dogs. This wire-directed detachable balloon is placed more easily and accurately than the conventional detachable balloons that are placed with the flow-directed method.     

Superior mesenteric artery angioplasty with the TEGwire: usefulness and technical difficulties.

The TEGwire percutaneous transluminal angioplasty balloon on a guide wire was used successfully for dilation of a proximal superior mesenteric arterial stenosis that was not well suited to dilation by conventional angioplasty catheters. After the stenosis was dilated, however, the balloon deflated only partially due to a kink in the TEGwire as it coursed over the acute angle between the aorta and the superior mesenteric artery. Several unsuccessful attempts to correct this problem were made; finally, the partially deflated balloon and the guide catheter had to be withdrawn. Although the TEGwire was used within the guidelines and recommendations of the product, this experience supports the manufacturer's recommendation that the TEGwire system should not be used with narrow-radius vascular curves such as that formed between the superior mesenteric artery and the aorta.     

New balloon-through-balloon angioplasty technique for the treatment of segmental lesions

A new balloon catheter on a wire that can be passed through standard 5- and 7-F angioplasty catheters recently became available. This capability allowed the authors to dilate segmental arterial lesions in which different balloon sizes were required without multiple catheter exchanges. Six patients were successfully treated with this technique, without complications.     

Arterial occlusive disease below the knee: treatment with percutaneous transluminal angioplasty performed with low-profile catheters and steerable guide wires

In 98 patients with arterial occlusive disease below the knee who were candidates for limb salvage surgery, percutaneous transluminal angioplasty (PTA) was performed with a low-profile balloon catheter and steerable guide wire system. Sixteen patients had bilateral disease; thus, there were 114 endangered limbs and 145 diseased vessels, including 19 with a single stenosis, 94 with multiple stenoses, and 32 with total occlusions. Primary anatomic success was achieved in all stenosed vessels and in 28 occluded vessels. Initial limb healing without amputation was achieved in 88% of limbs. In four patients occluded vessels could not be recanalized; thus, the four affected limbs were amputated. Two years after PTA, 32 of 37 patients available for follow-up had viable pain-free extremities. Cumulative limb salvage rate at 2 years was 86%. At this time, below-the-knee PTA is still recommended only for limb salvage candidates. However, with this new catheter and guide wire system, success rates have been increased and complication rates decreased. PTA may be useful in selected patients with severe claudication.     

Benign prostatic hypertrophy: retrograde transurethral dilation of the prostatic urethra in humans. Work in progress

Retrograde transurethral balloon dilation of the prostatic urethra was performed in five human volunteers with benign prostatic hypertrophy. Each patient underwent cystoscopy, uroflow studies, voiding cystourethrography, retrograde urethrography, and magnetic resonance imaging before dilation and at defined intervals afterward. The longest follow-up to date is 8 months. Patients were given topical anesthetics and mild sedatives, and dilation was performed with a 25-mm urethroplasty balloon catheter inflated at 3-6 atm for 10 minutes. All catheter manipulations were done with a guide wire and under fluoroscopic control. Significant resolution of symptoms of prostatism was seen in four patients. The unsatisfactory results in the last patient were believed to be caused by ineffectual dilation of predominantly middle lobe hypertrophy--a condition that is now regarded as a contraindication to dilation. This technique has promise to replace transurethral resection of the prostate as the treatment of choice for this common male ailment.     

A newly designed angioplasty catheter: “The gemini balloon”

A triple-lumen angioplasty composite balloon polyethylene catheter that incorporates a central lumen to ultimately accomodate a 0.035-inch wire is described. The two additional lumens are responsible for either simultaneous or independent expansion of the angioplasty balloons. Balloon dimensions vary from 3 mm through 8 mm, with any of the combinations being possible. Its principal indication will be in those extremely tight lesions that initially require dilation with the lower-profile balloon followed by the more appropriate, largersized, balloon, thus eliminating the necessity of catheter exchange and an additional balloon.     

Selective hepatic angiography using a balloon catheter guide

A 3-F balloon catheter guide was successfully used instead of a conventional guide wire for selective hepatic angiography in 30 patients. The technique provides an easy way to advance the catheter without complications.     

Recanalization of arterial occlusions using a specially designed steering catheter

Guide wires alone and straight or general purpose angiography catheters can be poorly directed when used for the recanalization of atherosclerotic occlusions of lower extremity arteries. To overcome this problem, a special catheter was designed to improve the steering of guide wires. The catheter has a 5F diameter and a lumen for a 0.035 inch guide wire. A metallic mesh layer within the wall provides good torque control and a soft and angled low profile tip allows steering of the guide wire by rotation of the catheter. This catheter was tested in 48 patients; 3 having iliac artery occlusions, 40 superficial femoral artery occlusions and 5 popliteal artery occlusions. The primary recanalization success rate was 88%. This type of catheter has proven to be very helpful in routine recanalization and balloon dilatation.     

Esophageal strictures in children. Treatment by balloon dilatation

The authors describe a new technique for dilatation of an esophageal stricture in a child. Under fluoroscopic control, a small guide wire is passed through the narrowed area. Dilation is accomplished with the Grüntzig balloon catheter.     

Angioplasty balloon inflation pressures during treatment of hemodialysis graft-related stenoses

PURPOSE: This two-part prospective investigation was designed to determine the balloon inflation pressures required to dilate stenoses associated with hemodialysis grafts and evaluate the burst pressures of five different angioplasty balloons. MATERIALS AND METHODS: Eighty-nine patients with dysfunctional hemodialysis grafts were enrolled and underwent fistulography. The diagnostic studies revealed 104 stenoses, which were treated with balloon angioplasty. The characteristics of these stenoses and the balloon inflation pressures required to dilate the lesions were recorded. In part two of this investigation, the burst pressures of five different angioplasty balloons were evaluated immediately after their use during angioplasty procedures. Twenty-five balloons of each type were inflated until the balloon burst or 30 atm of pressure was achieved. Several different statistical tests were used to analyze the data set. RESULTS: The mean balloon inflation pressure required to dilate all 104 stenoses was 17.2 atm. Subgroup analysis revealed that the mean balloon inflation pressure required to dilate 75 venous anastomotic stenoses was 17.9 atm and that a mean pressure of 15.6 atm was required to dilate 29 stenoses located within the native outflow veins. The angioplasty balloon burst pressure experiments revealed that the majority of the tested balloons can be inflated to pressures 5-6 atm greater than the manufacturers' rated burst pressures. However, the margin of safety for overinflation was variable among the balloons tested, and angioplasty balloons experience fatigue with repeated inflations. CONCLUSION: The majority of stenoses associated with hemodialysis grafts can be successfully dilated with use of available high-pressure angioplasty balloons.     

MR-guided angioplasty of renal artery stenosis in a pig model: a feasibility study

PURPOSE: To test the hypothesis that magnetic resonance (MR) imaging can guide the percutaneous treatment of renal artery stenosis in a pig model. MATERIALS AND METHODS: Ameroid constrictors were surgically placed around six renal arteries in four pigs. After 30-36 days, all stenoses were documented by conventional x-ray aortograms. MR-guided renal angioplasty was attempted for three stenoses. For these pigs, MR angiography was performed with use of contrast-enhanced three-dimensional (3D) techniques. The authors visualized catheters by filling them with dilute 4% gadolinium and imaging with two-dimensional (2D) and 3D MR fast spoiled gradient recalled echo techniques. Under MR guidance, the authors advanced a selective catheter into the affected renal artery and crossed the stenosis with a nitinol guide wire. Angioplasty was performed with a balloon catheter filled with dilute gadolinium. Stenosis and luminal diameter measurements were compared before and after angioplasty. RESULTS: After ameroid constrictor placement, four significant stenoses, one mild stenosis, and one occlusion developed. Under MR guidance, the authors achieved technical success in performing three of three (100%) attempted dilations. After MR-guided angioplasty, the mean reduction in stenosis was 35% and the mean increase in luminal diameter was 1.6 mm. CONCLUSION: Use of MR guidance for the angioplasty of renal artery stenosis in pigs is feasible.     

Percutaneous transluminal laser angioplasty. Progress over the past two years

The progress in percutaneous transluminal laser angioplasty (PTLA) over the past two years is presented. The technical development includes the application of new equipments to laser sources, delivery systems and monitors. We review new experimental research in rapidly establishing animal models and human postmortem specimens, as well as efforts to select adequate wave length and irradiation time for laser energy with suitable infusion media. A summary of clinical trials is given on expanding usage, complication rates and long-term patency of PTLA. The current trends in PTLA respecting guide wire assisted balloon angioplasty and other recanalization methods are described.     

Fracturing and stretching of angioplasty balloon catheters under bending with tension

Eight catheters from five manufacturers have been subjected to tests which combined bending and tension. Three failure mechanisms have been identified. These included separation of the balloon from its proximal attachment to the shaft, fracture of the shaft at its junction with the balloon, and undue ductility of the shaft. It is concluded that good catheter design should ensure that there is no sudden change in stiffness along the length of the catheter, and that the optimum relationship of ductility to stiffness has not yet been defined for catheters. Recommendations relating to these characteristics could be included in the British Standards relating to angioplasty balloon catheters.     

Laser catheter thermal angioplasty: technique and early results in 34 patients

The laser catheter is a nylon vascular catheter with a metal tip that has an end hole as well as side holes. The metal tip is heated by laser energy delivered through an optical fiber embedded in the catheter wall. The catheter may be advanced over a guidewire for use as an adjunct to balloon angioplasty or for use in smaller vessels as the exclusive method of recanalization. We used the catheter to treat 34 patients with 54 discrete vascular lesions in 35 extremities. Twenty patients were treated for clinically significant claudication and 14 for ischemic changes. Laser catheter-assisted balloon angioplasty was used to treat six iliac artery occlusions, two iliac artery stenoses, 10 superficial femoral artery occlusions, 12 superficial femoral stenoses, four popliteal artery occlusions, and three popliteal stenoses. Initial technical and clinical success in these patients, with follow-up periods of 3-6 months, was equivalent to the results of previous reports of laser probe-assisted balloon angioplasty. In 11 patients, 15 of 17 popliteal or tibial-peroneal lesions were treated with the laser catheter without subsequent balloon angioplasty. The treatment was successful in eight of these patients, with follow-ups for up to 6 months. Our results suggest that the laser catheter is a useful device for the treatment of vascular stenosis or occlusion when used either as an adjunct to balloon angioplasty or in smaller vessels as the exclusive method for angioplasty.     

Experience with new retrieval forceps for foreign body removal in the vascular, urinary, and biliary systems

A new type of foreign body retrieval forceps recently has become available. It consists of single- or multiple-tooth forceps mounted on a flexible stainless steel 0.038-inch shaft. The authors have successfully used this device in the vascular system (three cases), in the urinary tract (seven cases), and in the biliary system (two cases) without complications. Foreign bodies removed include a catheter fragment, angiographic guide wire, detachable balloon, stone retrieval basket, and various stents. All the procedures were performed quickly and without difficulty. For the authors, these forceps have become the first choice in many retrieval situations.