JACC Vnl . 17 . No. I Innuoy 1911 :90 -9
94
Percutaneou; Coronary Excimer Laser-Assisted Balloon Angioplasty* Initial Clinical and Quantitative Angiographic Results in 50 Patients TIMOTHY A . SANBORN, MD, SABINO R . TORRE, MD, SAMIN K, S HARMA . M D . RONNIE A . HERSHMAN, MD, MARC COHEN, MD, FACC, WARREN SHERMAN, MD, FACC, JOHN A. AMBROSE, MD . FACC Nea , York, Nee York
The initial clinical experience and quantitative aoglographk re. salts of pereutaneous coronary excimer laser-assisted balloon angioplasty we described for 55 lesions In 50 patients . With use of a strain chloride (300 nm) recliner lager generator and L .5 Se 1 .75 mm catheters, esdmer laser migilplaely was attempted at 135 as pulse width, 25 to 40 He repetition rate, 2 to 5 s laser delivery time and 30 to 60 snJ/mm= energy tuence. Laser success (>20% reduction in absolute percent diameter sleneols) was addeved In 41 (75%) of 55 lesions, with 100% subsequent balloon anglupksly success ('_00 absolute reduction
in
the previous percent diam-
9h
J > VIIOaN ar Al. . lulllNARY I:si nai
a
tACC VOL 17,N . 1 JunaarY 1991 94_J
I ASLIi-A .SSI51'rl] AN(i101'LASlY
success was achieved in only four (50%) of the first eight patients . However, it was observed that an increase in energy fluence by as little as
70
mJ/mmc could result in laser
success when the initial fluenco (30 tnJlmm t ) was unsuccess-
Figure 1 . Angiogrums of a combined excimer laser and balloon angioplasty of a genesis in an 0 year old saphennus vein bypass graft to an ohinse marginal artery .
Top,
Initial
8A%
stenosis in the
body of the saphenous vein bypass. Middle, Residual 26% stenosis alter two passes of a 1.75 mm excimer laser catheter through the lesion at 40 mJ .'mm'- energy fluence . 25 Hz repetition rate and 74 and
pulses, respectively, for laser delivery times of approximately 3 s each . aoeom, Final 12% stenosis after subsequent dilation with a 3 .5 mm balloon catheterr 72
eter stenosis. Balloon angioplasty success was defined as 1 min between attempts were used ; these procedures evolved as a result of experimental and clinical investigations (1,10,11) of several coronary laser systems including the laser probe, the laser balloon catheter and the excimer laser catheter . The one episude of excimer laser-related coronary vasospasm in this series occurred after a 4 s laser delivery time in a bend of a distal left circumflex coronary artery ; thus, mechanical trauma could also explain this event . In contrast to the practice of obstructing coronary blood flow during a balloon angioplasty procedure, the lack of ischemic events (angina, electrocardiographic changes or arrhythmias) during excimer laser angioplasty is probably related to the fact that the laser catheter never obstructed flow for more than a few seconds . Optimal number of loser passes . An additional aspect of laser treatment that requires further investigation is the optimal number of passes that should be made throu f,h the lesion. Initially, the excimer laser angioplasty procedure was considered complete after the lesion was ira.erecei a single
5ACC Vo1, 17. No. I tannery 1991'94-9 time . Later, it was found that repeat pastes through a lesion provided smoother passage with each subsequent attempt as well as a greater reduction in the percent diameter stenosis . Thus, tactile feedback m the operator as well as angiographic appearance entered into the decision of when to cominuc or conclude the eacimer laser angioplasty procedure . Additional factors such as the pressure gradient across the lesion or the ultrasonic or angioscopic appearance of the lesion may aid in assessing the result of ezcimer laser angioplasty . This additional information may help determine when to stop the eacimer laser procedure to prevent vascu . tar trauma of dissection or perforation . At present with angiographic analysis alone, it is impossible to determine to what extent luminal improvement is due to true laser vaporization versus a mechanical (that is, Dotter) effect, Perhaps intraluminal ultrasonography will help answer this issue . Fellaw-up results. Our preliminary clinical [DROW-Up results are encouraging; however, the observation time is short. The maturity at patients arc just now returning for 6 month follow-up angiography . The clinical follow-up data of these patients are currently the subject of a multicenter registry (12). The effects of various procedural factors such as the size of the fiber-optic device and the residual stenosis after ezcimer laser angioplasty will be examined . Conclusions. Percutaneouscoronary excimerUser angioplasty appears to be a feasible and safe procedure in a highly selected group of patients : however, the fiberoptic catheters, laser-operating variables and angioplasty techniques are all undergoing significant development and modification . Once the equipment and techniques have become more established, randomized trials should be initiated to compare ezcimer laser angioplasty or excimer laser-assisted balloon angioplasty with conventional balloon angioplasty to determine whetherthis teehoology improves angioplasty safety or restenosis rates. However, on the hosts of present results .
SANBORN El. AL. CORONARY F%CIMER LASER-ASSISrLO ANOIOFLASiY
99
randomized clinical trials are not worth considering until a larger channel can be created by laser vaporization to result in greater reduction in the atenosis to
94
Percutaneou; Coronary Excimer Laser-Assisted Balloon Angioplasty* Initial Clinical and Quantitative Angiographic Results in 50 Patients TIMOTHY A . SANBORN, MD, SABINO R . TORRE, MD, SAMIN K, S HARMA . M D . RONNIE A . HERSHMAN, MD, MARC COHEN, MD, FACC, WARREN SHERMAN, MD, FACC, JOHN A. AMBROSE, MD . FACC Nea , York, Nee York
The initial clinical experience and quantitative aoglographk re. salts of pereutaneous coronary excimer laser-assisted balloon angioplasty we described for 55 lesions In 50 patients . With use of a strain chloride (300 nm) recliner lager generator and L .5 Se 1 .75 mm catheters, esdmer laser migilplaely was attempted at 135 as pulse width, 25 to 40 He repetition rate, 2 to 5 s laser delivery time and 30 to 60 snJ/mm= energy tuence. Laser success (>20% reduction in absolute percent diameter sleneols) was addeved In 41 (75%) of 55 lesions, with 100% subsequent balloon anglupksly success ('_00 absolute reduction
in
the previous percent diam-
9h
J > VIIOaN ar Al. . lulllNARY I:si nai
a
tACC VOL 17,N . 1 JunaarY 1991 94_J
I ASLIi-A .SSI51'rl] AN(i101'LASlY
success was achieved in only four (50%) of the first eight patients . However, it was observed that an increase in energy fluence by as little as
70
mJ/mmc could result in laser
success when the initial fluenco (30 tnJlmm t ) was unsuccess-
Figure 1 . Angiogrums of a combined excimer laser and balloon angioplasty of a genesis in an 0 year old saphennus vein bypass graft to an ohinse marginal artery .
Top,
Initial
8A%
stenosis in the
body of the saphenous vein bypass. Middle, Residual 26% stenosis alter two passes of a 1.75 mm excimer laser catheter through the lesion at 40 mJ .'mm'- energy fluence . 25 Hz repetition rate and 74 and
pulses, respectively, for laser delivery times of approximately 3 s each . aoeom, Final 12% stenosis after subsequent dilation with a 3 .5 mm balloon catheterr 72
eter stenosis. Balloon angioplasty success was defined as 1 min between attempts were used ; these procedures evolved as a result of experimental and clinical investigations (1,10,11) of several coronary laser systems including the laser probe, the laser balloon catheter and the excimer laser catheter . The one episude of excimer laser-related coronary vasospasm in this series occurred after a 4 s laser delivery time in a bend of a distal left circumflex coronary artery ; thus, mechanical trauma could also explain this event . In contrast to the practice of obstructing coronary blood flow during a balloon angioplasty procedure, the lack of ischemic events (angina, electrocardiographic changes or arrhythmias) during excimer laser angioplasty is probably related to the fact that the laser catheter never obstructed flow for more than a few seconds . Optimal number of loser passes . An additional aspect of laser treatment that requires further investigation is the optimal number of passes that should be made throu f,h the lesion. Initially, the excimer laser angioplasty procedure was considered complete after the lesion was ira.erecei a single
5ACC Vo1, 17. No. I tannery 1991'94-9 time . Later, it was found that repeat pastes through a lesion provided smoother passage with each subsequent attempt as well as a greater reduction in the percent diameter stenosis . Thus, tactile feedback m the operator as well as angiographic appearance entered into the decision of when to cominuc or conclude the eacimer laser angioplasty procedure . Additional factors such as the pressure gradient across the lesion or the ultrasonic or angioscopic appearance of the lesion may aid in assessing the result of ezcimer laser angioplasty . This additional information may help determine when to stop the eacimer laser procedure to prevent vascu . tar trauma of dissection or perforation . At present with angiographic analysis alone, it is impossible to determine to what extent luminal improvement is due to true laser vaporization versus a mechanical (that is, Dotter) effect, Perhaps intraluminal ultrasonography will help answer this issue . Fellaw-up results. Our preliminary clinical [DROW-Up results are encouraging; however, the observation time is short. The maturity at patients arc just now returning for 6 month follow-up angiography . The clinical follow-up data of these patients are currently the subject of a multicenter registry (12). The effects of various procedural factors such as the size of the fiber-optic device and the residual stenosis after ezcimer laser angioplasty will be examined . Conclusions. Percutaneouscoronary excimerUser angioplasty appears to be a feasible and safe procedure in a highly selected group of patients : however, the fiberoptic catheters, laser-operating variables and angioplasty techniques are all undergoing significant development and modification . Once the equipment and techniques have become more established, randomized trials should be initiated to compare ezcimer laser angioplasty or excimer laser-assisted balloon angioplasty with conventional balloon angioplasty to determine whetherthis teehoology improves angioplasty safety or restenosis rates. However, on the hosts of present results .
SANBORN El. AL. CORONARY F%CIMER LASER-ASSISrLO ANOIOFLASiY
99
randomized clinical trials are not worth considering until a larger channel can be created by laser vaporization to result in greater reduction in the atenosis to
