A novel approach to the placement of Palmaz-Schatz biliary stents in saphenous vein grafts

The placement of Palmaz-Schatz biliary stents has become a successful method to treat stenoses in large saphenous vein grafts. Unlike coronary stents, the biliary stents are not routinely delivered with a selective delivery sheath and may be more difficult to deliver and prone to detachment from the balloon and even embolization during delivery. In order to enhance the ability to deliver these stents, a guide-within-a-guide system was developed. A 7F guiding catheter was used as a selective delivery sheath within a standard guiding catheter. Nineteen biliary stents were successfully placed in vein grafts in 15 patients using this system. One procedure was complicated by an embolic event documented angiographically following intragraft delivery of urokinase but prior to stent implantation.

Adaptor device for shortening guide catheters to access distal lesions in coronary angioplasty

One of the challenges in interventional cardiology is accessing distal stenoses in both native coronary arteries and bypass grafts. This article reports the fabrication and use of an adaptor device that can be connected to the proximal segment of a shortened guide catheter for easier and safer access to these distal lesions.

Balloon angioplasty of chronic total coronary artery occlusions: what does it cost in radiation exposure, time, and materials?

Coronary angioplasty of chronic total occlusions is known to have a lower success rate and higher frequency of restenosis than angioplasty of subtotal stenoses, but there are no data describing the additional time, resources, and radiation exposure associated with this procedure. The purpose of this study was to compare these features in 90 consecutive patients who underwent angioplasty of a total occlusion (group 1) to those of 100 consecutive patients who underwent angioplasty of a subtotal stenosis (group 2). Angioplasty was successful in 60% of group 1 and in 94% of group 2 patients. Procedures were longer in group 1 and significantly more guide catheters, angioplasty balloon catheters, and guide wires were required per patient compared to group 2. The volume of contrast media used in each group was similar. Estimates of radiation entry exposure, calculated from fluoroscopy exposure times and using data from phantom studies, were 53 R (roentgen) per patient in group 1 vs. 34 R in group 2. These procedures were performed using pulsed progressive fluoroscopy; radiation exposure would be considerably higher using conventional fluoroscopic systems. Cineangiographic radiation exposures were similar for each group and accounted for an average additional exposure of 14-22 R for each procedure. Total radiation exposure was reduced in both groups when the angioplasty procedure was combined with the diagnostic angiogram. These observations should be considered when dilation of a total occlusion is planned. Efforts to reduce the amount of radiation exposure should remain a priority in interventional catheterization laboratories.

Relation of stenosis morphology and clinical presentation to the procedural results of directional coronary atherectomy

BACKGROUND

Directional coronary atherectomy has recently become available to treat coronary stenoses. This study was performed to determine the relation of patient characteristics and stenosis morphology to procedural outcome with directional coronary atherectomy to gain insight into which patients might be best treated with this device.

METHODS AND RESULTS

Four hundred stenoses from 378 patients consecutively treated at six major referral institutions were analyzed. Angiographic data were assessed at a central angiographic laboratory using standardized morphological criteria and computer-assisted quantitative dimensional analyses. Procedural success was achieved in 87.8% of stenoses, and major ischemic complications (death, myocardial infarction, and emergency bypass surgery) occurred in 6.3% of patients. Lesion success and complications were closely correlated with recognized modified American College of Cardiology/American Heart Association Task Force lesion morphological criteria. Observed for type A stenoses were 93% success and 3% complication rates; for type B1 stenoses, 88% success and 6% complication rates; and for type B2 stenoses, 75% success and 13% complication rates, respectively. There were too few type C stenoses treated to analyze. Furthermore, multivariate testing demonstrated stenosis angulation (multivariate p less than 0.001), proximal tortuosity (p less than 0.001), decreased preatherectomy minimum lumen dimension (p = 0.032), and calcification (p = 0.041) to correlate independently with adverse outcome and complex, probably thrombus-associated stenoses to have a favorable outcome (p = 0.055). Operator experience (p = 0.020) and a history of restenosis (p = 0.022) also favorably influenced outcome.

CONCLUSIONS

The procedural outcome of directional coronary atherectomy is highly associated with coronary stenosis morphology. Furthermore, after appropriate stratification for morphology and clinical presentation, overall atherectomy procedural outcome may be similar to that achieved with coronary angioplasty. However, specific subsets of patients may have relatively better outcome with either atherectomy or balloon angioplasty.

A randomized comparison of the nephrotoxicity of iopamidol and diatrizoate in high risk patients undergoing cardiac angiography

Three hundred seven high risk patients with renal impairment (serum creatinine greater than or equal to 1.5 mg/dl) were randomized in a double-blind manner to either iopamidol (a nonionic, low osmolar radiocontrast agent) or diatrizoate (a conventional radiocontrast agent) at cardiac angiography with subsequent follow-up study of renal function. Baseline clinical and angiographic variables were similar in the iopamidol (n = 155) and diatrizoate (n = 152) groups. Change in renal function after angiography was less pronounced with iopamidol compared with diatrizoate as measured by mean ( +/- SD) increase in 24 h serum creatinine (0.11 +/- 0.2 versus 0.22 +/- 0.26 mg/dl, p less than 0.001), mean maximal increase in serum creatinine (0.2 +/- 0.44 versus 0.38 +/- 0.73 mg/dl, p less than 0.0001) and percent of patients with a maximal increase in serum creatinine greater than 0.5 mg/dl (8% versus 19%, p less than 0.01). Such differences could not be documented in diabetic patients using insulin. There was no significant difference between agents in the number of patients developing clinically severe acute renal dysfunction. It is concluded that iopamidol is less nephrotoxic than diatrizoate in high risk patients at cardiac angiography. However, the difference in nephrotoxicity is small, of no major clinical significance in the majority of high risk patients and could not be documented in insulin-using diabetic patients. Iopamidol may be the preferred agent in certain patients with advanced renal impairment, but further study is warranted.

Coronary atherectomy: first 50 patients at the Mayo Clinic

The safety and efficacy of a novel coronary atherectomy device were evaluated in the first 50 patients who underwent 53 such procedures at the Mayo Clinic. This treatment was used for atheromatous lesions in 27 patients and for restenosis after percutaneous transluminal coronary angioplasty in 23; in 3 patients, it was repeated for recurrent stenosis (2) or a persistent intimal flap (1). Successful results, defined as a reduction of the stenosis by 40% or more in association with removal of tissue, absence of Q-wave infarction, and no need for a bypass surgical procedure during in-hospital follow-up, were achieved in 47 of the 53 procedures (89%). Atherectomy reduced the stenoses from a mean of 87% to 15%. Failures occurred in 6 of the 53 procedures (11%). Three of these patients subsequently underwent successful conventional balloon angioplasty, and three required surgical treatment. Six patients had minor complications--embolization of atheromatous material in two, intimal dissection in two, and side-branch occlusion and transient thrombosis in one each. Coronary atherectomy with use of this device promises to be a relatively safe and efficient treatment of coronary artery stenosis.