Standalone cutting balloon angioplasty for the treatment of stent-related restenosis: acute results and 3- to 6-month angiographic recurrent restenosis rates

Despite excellent acute reperfusion results, 20%-30% of patients who undergo coronary stent implantation will develop angiographic restenosis and may require same additional treatments. Cutting Balloon angioplasty (CBA) causes less histological damage outside of the incised area than a regular balloon. However, regular plain old balloon angioplasty is sometimes required before CBA, as is adjunctive stenting and adjunctive angioplasty. These adjunctive strategies may negate the advantages of CBA. There is little data available on CBA as a standalone therapy for stent-related restenosis (SRS). The aim of this study was to evaluate the acute and 3- to 6-month angiographic recurrent restenosis rates following standalone CBA in a patient population treated for SRS and in whom optimal acute results were obtained. In this study, 40 patients with SRS (54 lesions) underwent standalone CBA with optimal acute results. For all lesions, coronary angiography was conducted before and after a standalone CBA procedure for SRS and systematically during 3-6 months to assess recurrent angiographic restenosis rates in the study population. In the study lesions, SRS was either diffuse disease (> 15 mm; 52%) or focal type (48%). Cutting Balloon diameter was 3.20 +/- 0.44 mm and maximal inflation pressure 8.7 +/- 1.2 atm. Ratio of Cutting Balloon diameter to restenotic stent diameter was 0.996 +/- 0.487. Multiple inflations (6 +/- 3 times) were performed. Number of used Cutting Balloon was 1.02 +/- 0.14. Complications were as follows; one non-Q-wave MI (1.9%); 0 death (0%), and 17 repeat target lesion revascularizations (TLRs; 32%). Follow-up coronary angiography (CAG) was not attained for one patient. The angiographic recurrent restenosis rate was 34%, with a higher rate observed when the SRS was diffuse type, 50% vs. 16% for focal-type SRS (P < 0.01). The recurrent restenosis rate for smaller vessels (vessel diameter < or = 3.0 mm) was the same as for larger ones. At follow-up CAG, diffuse-type recurrent restenosis (56%) presented nearly as frequently as that presenting in the original SRS lesions (52%). But four diffuse-type SRS (29%) changed into focal-type recurrent stenosis. In this study, standalone CBA for SRS with optimal acute results was associated with an angiographic restenosis rate of 34%. Diffuse-type disease had a higher recurrent restenosis rate. When CBA achieves acute optimal results, adjunctive stenting or adjunctive PTCA are not always necessary, particularly when the SRS is focal. As a result of CBA, some diffuse-type SRS may change into focal-type recurrent stenosis by the time of the next intervention.

Serial intravascular ultrasound assessment of the efficacy of intracoronary gamma-radiation therapy for preventing recurrence in very long, diffuse, in-stent restenosis lesions

BACKGROUND

The efficacy of coronary gamma-irradiation in preventing recurrent in-stent restenosis (ISR) is well established. However, brachytherapy may be less effective in very long, diffuse ISR lesions.

METHODS AND RESULTS

We used serial intravascular ultrasound (IVUS) to study patients with long, diffuse ISR lesions (length, 36 to 80 mm) who were enrolled in (1) Long WRIST (Washington Radiation In-Stent Restenosis Trial), a double-blind, placebo-controlled trial of intracoronary gamma-irradiation (15 Gy at 2 mm from the source) and (2) high-dose (HD) Long WRIST, a registry that used a dose prescription of 18 Gy at 2 mm from the source. IVUS was performed using automated pullback (0.5 mm/s). Stent, lumen, and intimal hyperplasia were measured at 2-mm intervals. Complete postintervention and follow-up IVUS imaging was available in 30 irradiated and 34 placebo patients from Long WRIST and in 25 patients from HD Long WRIST. Stent length was longer in HD Long WRIST than in placebo or treated patients in Long WRIST (P=0.0064 and P=0.0125, respectively). Otherwise, baseline measurements were similar. At follow-up, the minimum lumen area was largest in the HD Long WRIST patients (4.0+/-1.4 mm(2)); areas were 2.9+/-1.0 mm(2) in irradiated patients in Long WRIST and 1.9+/-1.1 mm(2) in placebo patients in Long WRIST (P<0.005 for all comparisons).

CONCLUSIONS

- Serial IVUS analysis shows that gamma-irradiation reduces recurrent in-stent neointimal hyperplasia in long, diffuse ISR lesions; however, it is even more effective when given at a higher dose.

Long-term surveillance by duplex scanning of nonrevised infragenicular graft stenosis

To define the prognosis of nonrevised graft stenosis, we studied 68 infragenicular bypass grafts in patients entered into our duplex surveillance program between 1986 and 1987. Patients were grouped according to the grade of stenosis as follows: grade I = < 50% stenosis, grade II = 50% to 75% stenosis, and grade III = 75% to 99% stenosis. Time until maximum stenosis was stratified into three intervals (< 3 months, between 3 and 12 months, and > 12 months). Cumulative patency rates from the time of maximum stenosis to failure were calculated using Kaplan-Meier analysis. Fifty-three grafts (78%) developed stenoses: 10 with grade I, 25 with grade II, and 18 with grade III stenosis. Eighty-nine percent of the 18 graft occlusions occurred within 2 years. Two grafts occluded after 2 years without any severe stenosis or preceding clinical signs. During follow-up 15 nonrevised stenosed grafts (four with grade I, five with grade II, and six with grade III stenosis) remained patent longer than 2 years with a mean follow-up of 72 months. Statistical analysis for graft failure determined that grade II to III stenoses led to graft occlusion significantly earlier than grade 0 to I stenoses (p = 0.017). If graft failures resulting from revision were separated from the analysis, the time interval from operation to maximum stenosis (within 1 year) remained marginally significant for predicting occlusion, whereas no correlation was found between the grade of maximum stenosis and occlusion. Thus the prognosis for graft stenosis depends on the grade of stenosis and on the time interval from operation to stenosis. Therefore duplex surveillance seems to be most important within the first 24 months only, but is of little use in predicting impending graft failure beyond 2 years in asymptomatic patients.

Intra-arterial thrombolytic therapy: a combined approach with angioplasty and/or minor surgery

Low-dose intra-arterial treatment was performed in 124 patients who underwent a total of 142 procedures. The series included 87 occluded arteries and 55 occluded grafts. In only 29 instances (21%) was thrombolysis alone sufficient. In another 77 procedures (54%) the thrombolysis was followed by either angioplasty or minor surgery. In the remaining 36 treatments (25%) lysis of the occlusion failed. A successful end result of combined treatment was achieved in 67 of 77 (87%) procedures. Including the 29 patients in whom thrombolysis alone sufficed, a total of 96 of the 142 procedures (67%) were successful, with the overall success rate being better in grafts (78%) than in arteries (61%). The suprainguinal lesions had a significantly better response compared to the infra-inguinal ones. The evaluation of all procedures was done at the time of discharge from hospital. Complications were related either to local or systemic hemorrhage or distal embolization. Death related to treatment occurred in three patients.

Thrombolysis in peripheral arterial graft occlusion

Acute thrombosis of arterial bypass grafts in the lower extremities poses a significant risk for limb loss. Graft salvage in patients affected by this complication remains a challenge. The vascular surgeon must consider the spectrum of treatment options (thrombolysis, thrombectomy, graft replacement) in managing acute graft thrombosis. Oral anticoagulants should be considered in patients with low-flow polytetrafluoroethylene (PTFE) grafts and after successful thrombolysis, with or without revision. The role of thrombolytic therapy for occluded vein grafts is less clear, but successful lysis is likely in patients who present within 48 hours of graft thrombosis and the etiology includes a correctable graft stenosis.

[Etiology and classification of arterial stenosis of transplanted kidney]

Stenosis of the artery of a transplanted kidney, which developed in late-term periods after allogeneic kidney transplantation, was revealed in 30 patients, which accounts for 6% of the total number of patients who underwent transplantation. The authors discuss the etiology of this complication in detail and suggest their own classification.