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Objectives: This study sought to determine whether infrapopliteal transcatheter interventions can salvage ischemic limbs in diabetic patients referred for below the knee amputation at our institution., Background: The value of transcatheter interventions in diabetic crural arteries is controversial. Tissue oxygen partial pressure (TCO2) levels < 40 mm Hg predict poor wound healing., Methods: Percutaneous interventions were performed in 29 consecutive diabetic patients in need of limb salvage. Technical success was defined as < 20% residual vessel stenosis. Clinical success was defined as the avoidance of amputation and achievement of wound healing. At hospital discharge, patients were treated with Coumadin and aspirin. Ankle-brachial index (ABI) and TCO2 measurements were obtained before and after the intervention., Results: After 12-month follow-up, six patients had presistent wounds, whereas 23 experienced wound healing. Forty of the 50 infrapopliteal arteries successfully dilated were occluded, with a mean (+/-SD) lesion length of 18.0 +/- 3.5 cm. After the procedure, TCO2 improved from 27.82 +/- 9.97 mm Hg (95% confidence interval [CI] 23.95 to 31.69) to 54.5 +/- 14.73 mm Hg (95% CI 48.79 to 60.21, p < 0.0001), whereas the ABI did not (p > 0.2). TCO2 predicted procedural and clinical success (p < 0.0182)., Conclusions: Infrapopliteal transcatheter interventions in diabetic patients may salvage the majority of limbs doomed to amputation. Although TCO2 measurements are valuable in predicting wound healing and success after interventions, ABI measurements are not.

The vast majority of failures of transcatheter interventions in patients with peripheral vascular disease are due to inability to cross the lesion with a guidewire. Although the use of the Glidewire has clearly improved the success rate, failures with especially chronic total occlusions still occur. We describe a new technique using the very stiff backend of the Glidewire, which we have found very successful, when conventional techniques fall in crossing highly resistant lesions.

This report introduces a new technique for monitoring and understanding the mechanical events taking place during coronary balloon angioplasty. A standard inflation syringe is instrumented with transducers to record intra-balloon pressure and volume during stenosis dilatation. The theoretical and practical aspects of obtaining and interpreting PTCA "pressure-volume" curves are described. Based on mechanical principles, this method may provide the PTCA operator with information regarding the stiffness and resilience of each stenosis, the mechanism of dilatation, and a measure of adequacy of lumen enlargement even before the balloon is deflated.

The effect of percutaneous transluminal coronary angioplasty (PTCA) on myocardial perfusion reserve has not been previously determined. Accordingly, 11 patients underwent positron imaging with [13N]ammonia or 82Rb at rest and following dipyridamole + handgrip stress before and after PTCA. The ratio of stress to rest activity (S:R) was determined for each region of interest. Relative myocardial perfusion reserve by positron tomography (RMPR) was calculated by dividing S:R of the stenotic area by a corresponding value from a normal reference area of the same patient. Automated quantitative coronary arteriography was used to objectively measure the percent diameter (%D) and the percent area narrowing (%A) of the stenoses. In nine patients with successful PTCA, %D and %A improved (68 +/- 10 to 49 +/- 15% and 92 +/- 3 to 72 +/- 5%) and RMPR increased from 0.79 +/- 0.07 to 0.96 +/- 0.05. In the two patients in whom PTCA was unsuccessful, RMPR was unchanged. Changes in RMPR correlated inversely with changes in %D (r = -0.68) and %A (r = -0.92) and directly with improved coronary flow reserve derived from all stenosis measurements (r = 0.73, p less than 0.001 for each). This study suggests that dipyridamole + handgrip stress imaging with PET can be used to assess changes in myocardial perfusion reserve before and after PTCA with the potential for determining restenosis noninvasively.

Currently there is no accepted method for measurement of myocardial infarct size in humans. Analysis of both global and regional left ventricular function provides an indirect indication of extent of myocardial necrosis. Acute coronary occlusion results in cessation of function and in some cases dilatation of the involved myocardial segment. Often there is reciprocal hyperfunction of the non-ischemic segments resulting in little impairment of global ventricular function. Average global left ventricular function does not change from hospital admission through hospital discharge in patients with acute myocardial infarction, treated conventionally. With successful coronary reperfusion, however, both regional and global ventricular function have been reported to improve over several weeks after the initial ischemic insult. Improvement in ventricular function is most likely to occur in patients with collaterals or some preservation of antegrade flow to the involved myocardial segment who successfully undergo reperfusion. Return of function occurs in 82% of patients successfully treated within two hours after onset of chest pain. Approximately 50% of patients successfully treated two to 18 hours after onset of chest pain have demonstrated significant improvement in function. Patients admitted with normal ventricular function are less likely to demonstrate improved global ventricular function than those admitted with ejection fractions less than 45%. Acute PTCA with or without thrombolysis may result in a greater return in function than thrombolysis alone. Delayed revascularization more than 48 hours after successful reperfusion does not appear to affect ventricular function a late follow-up but may improve probability of survival. Patients discharged with ejection fractions greater than 45% clearly have an improved prognosis compared to those with depressed ejection fractions post-myocardial infarction.