Catheterization and Cardiovascular Diagnosis 262319-322 (1992)
Basic Investigation
Percutaneous Vascular Hemostasis Device for Intervent ional Procedures Alvaro Merino, MD, Catherine Faulkner, RN, Alejandro Corvalan, MD, and Timothy A. Sanborn, MD A new 11.5F over-the-wire vascular hemostasis device was compared to conventional manual compression in normal swine femoral arteries. Using percutaneous techniques, the collagen was deposited and hemostasis achieved in 7 vessels after 1 minute total, plus 4 minutes partial compression, while control manual compression required more than 5 minutes total compression to avoid hematoma formation. One month follow-up of treated arteries (n = 4) and controls (n = 3) showed no impairment in distal pulse or differences in histology at the puncture site in the control and treated arteries. Thus, the vascular hemostasis device technique is safe and effective, achieves hemostasis with less compression time and complications, and does not interfere with arterial wall healing or compromise the lumen. 1992 Wllay-Llsa. Inc
Key words: angiography, angioplasty, normal swine femoral arteries
INTRODUCTION
500 mg of ketamine (Ketasel, Bristol Laboratories) given intramuscularly, and anesthesia was induced with Invasive cardiovascular techniques sustain a small but 200 mg of intravenous pentobarbital with a booster of constant rate of vascular complications which although 130 mg every 45 minutes thereafter. The pig was then not fatal [ 11, can produce significant patient discomfort, intubated and mechanically ventilated with a Harvard and in some cases require blood transfusion or surgical respirator. No anticoagulation was used. Management intervention. Although improvements in catheter and and procedures performed on experimental animals were sheath technology have reduced the complication rate of approved by the Internal Review Board of the Institution, the percutaneous approach and even permitted outpatient and conformed to the position of the American Heart catheterization [3-5 J, vascular complications related to Association on Research Animal Use. hemostasis ranged from 4% to 12% in several recent studies [2,6-91. In addition, interventional techniques Vascular Hemostasis Device Technique performed after thrombolysis, or requiring greater size The hemostasis device (Datascope, Oakland, NJ) concatheters as with atherectomy, have been associated with sists of three parts (Fig. 1): a blunt tip dilator, an 11.5F higher complication rates [6,7,10-141. Thus, a safe and sheath, and 50 mg of collagen material positioned at the effective technique for reliably obtaining hemostasis proximal end of a cartridge. The procedure for placing could decrease the patient discomfort of conventional manual compression, permit earlier ambulation, and reduce the risk of vascular complications. From the Division of Cardiology, Department of Medicine and DeA novel vascular hemostasis device (VHD) for the partment of Pathology, Mount Sinai Medical Center, New York; Datapercutaneous deposition of collagen at the arterial punc- scope Corp., Oakland, NJ, in association with the New York Cardiac ture site was applied after percutaneous sheath insertion Center, Englewood Cliffs, NJ. in normal swine femoral arteries and compared to conReceived December 16, 1991; revision accepted March 1 I . 1992. ventional manual compression. The feasibility, safety, and efficacy of the technique were determined. The ad- Address reprint requests to Timothy A . Sanborn, M.D., Cardiology aptation of hemostatic material to the arterial surface and Division, Starr 4, New York Hospital-Cornell Medical Center, 525 E. 68th Street, New York, NY 10021. the healing process were studied by histology. MATERIALS AND METHODS Animal Model
A total of eight normal Yorkshire albino pigs (aged 3-5 months; weight 30-50 kg) were sedated with 0 1992 Wiley-Liss, Inc.
Presented as an abstract at the 64th annual scientific sessions of the American Heart Association, Anaheim, CA, November 1991. Dr. Merino is the recipient of an NIH-Fogarty International Fellowship Award. Dr. Sanborn is the Arthur Ross Scholar in Cardiovascular Medicine. Supported in part by a grant from Datascope Corp., Oakland, NJ.
320
Merino et al.
Fig. 1. Vascular hemostasis device: (Top) collagen loaded cartridge, (Middle) cartridge in sheath, (Bottom) blunt dilator over 0.035 inch guidewire.
the device consists of two independent operations which are required to achieve proper collagen placement and hemostasis. First, a 6F sheath (USCI, Billerica, MA), which had previously been implanted into the femoral artery, was removed over a 0.035" guidewire while hemostasis was maintained by manual compression of the artery. Then, the 11.5F dilator and the sheath were introduced over the guidewire up to the arterial puncture site until resistance was encountered (Fig. 2A). The guidewire and the dilator were then removed while maintaining total arterial compression. The collagen loaded cartridge was placed into the proximal end of the sheath and the collagen was advanced and pushed out of the sheath toward the puncture site (Fig. 2B). The sheath was held in place, and then slowly pulled back as the cylinder of collagen was discharged. After I minute of total manual compression, the sheath was removed and gentle upstream compression was maintained for another 4 minutes. After 5 minutes, all compression ceased and hemostasis was assessed (Fig. 2C). Acute Studies
First, in order to visualize the sequence and hemostatic function of the technique most completely, 5 femoral arteries were exposed by surgical dissection and canulated by Seldinger technique with a 6F sheath. Then, the hemostasis device was exchanged over a 0.035" guidewire for the original 6F sheath at the puncture site to assess the feasibility of the technique. In another 3 arteries, a 6F sheath was placed percutaneously in the femoral artery, the hemostasis device was applied, and hemostasis was achieved. Then, the animals were sacrificed with an overdose of pentobarbital and the artery was removed, rinsed, and stored in glutaraldehyde-formaldehyde for histological analysis. Chronic Study The arterial healing process was studied in 4 animals. After percutaneous femoral artery cannulation with a 6F
COMMON'FEMORAL
COLLAGEN
COMMON FEMORAL
ARTERY Fig. 2. Technique for the application of the vascular hernostasis device. See text for explanation.
sheath, the VHD was placed in 4 arteries, with another 3 vessels serving as control. One femoral artery could not be successfully cannulated with the 6F sheath, and therefore was excluded from analysis. The animals were allowed to recover from anesthesia and were followed with visual inspection of the inguinal area, and distal pulses were assessed after I month. The animals were sacrificed as described above and the femoral arteries were removed, rinsed, and stored in glutaraldehyde-formaldehyde for histological study. RESULTS Acute Study
With the artery exposed, the technique was found to be reproducible and feasible in five attempts. There were no protrusions of the dilator into the arterial lumen. In all five cases, the collagen material was easily advanced to the surface of the artery without introducing it into the vessel. In contact with blood, the collagen was transformed into a gelatinous mass that spread over the punc-
Percutaneous Vascular Hemostasis Device
321
ture site producing a seal of the arteriotomy. Percutaneous placement of the VHD was also easily performed in three vessels. The only technical requirement was that the track through the skin and subcutaneous tissue had to be enlarged with a hemostat prior to initial needle puncture in order to accept the device’s 11.5F sheath. No hematoma was detected after 1 minute total and 4 minutes partial compression in the treated animals. Macroscopic analysis demonstrated precise placement of the collagen material at the puncture site without protrusion of the collagen into the arterial lumen. Chronic Study No hematoma developed in four device-treated arteries after 1 minute total and 4 minutes partial compression, contrary to three control vessels that required more than 5 minutes total compression to achieve hemostasis without hematoma formation. At 1 month follow-up, no encapsulation, foreign body reaction, or infection was found at the puncture site. The distal pulses were normal. When surgical dissection was performed to examine the arteries, minimal fibrous scar tissue was found on the arterial surface, which was indistinguishable in control and treated animals. Furthermore, there was no evidence of thrombosis in the arterial lumen. Histological analysis of the puncture site showed an intact lumen, normal intimal and medial layers, and a fibrous adventitial cap. At the puncture site, an increase in collagen fibers was observed at the external part of the tunica media in both control and treated vessels (Fig. 3A,B). DISCUSSION Device Feasibility and Efficacy In this preclinical evaluation, a new vascular hemostatic device for percutaneous procedures was tested and found to be easy to use by persons experienced with conventional catheterization technique. The device achieved hemostasis in less than 5 minutes compression, without producing hematomas or compromising the arterial lumen or distal circulation. Histological sections from both acute and chronic studies demonstrated the patency of the artery in all the cases. In histological analysis after 1 month follow-up, total absorption of the collagen on the arterial surface was noted, with normal intimal and medial layers and no differences in the healing response between control and treated vessels. Safety In this initial evaluation, tactile feedback was used to detect resistance as the dilator and sheath were advanced to contact the artery. Using this tactile sense as a guide, no protrusion of the collagen into the arterial lumen was observed on gross inspection. In order to further decrease
Fig. 3. Micrographs of swine femoral artery, 1 month after percutaneous cannulation with a 6F sheath. A: Control artery. Hemostasis was achieved with conventional manual compression. A fibrous cap is seen surrounding the artery. lntimal and medial layers are intact. 8 : Treated artery. The vascular hemostasis device was applied. Fibrous tissue is seen covering the puncture site. lntimal and medial layers are preserved. Trichrome stain, x 10.
the risk of accidental injection of the collagen into the artery, the depth of the artery at the time of the initial arterial puncture can be marked on the percutaneous needle at the level of the skin entry site. Newer equipment intended for human use will have color coded markings on the external surface of the sheath to facilitate the assessment of the depth of the artery and thus permit collagen placement precisely on the puncture site. This is the major advantage of this system, because the undesirable introduction of a significant amount of collagen into the artery would almost certainly lead to vessel occlusion. Although a possible complication, infection of the collagen material at the puncture site was not present in any case at 1 month follow-up in our study, nor has it been reported in ongoing clinical trials [ 151.
322
Merino et al.
Potential Clinical Applications
Routine use of the vascular hemostatic device after cardiac catheterization could certainly reduce the percentage of bleeding complications, as well as the arterial compression time. But the advantages of the VHD will be best demonstrated when used after interventional techniques, especially after coronary atherectomy, in which up to 11F guiding catheters are required and vascular complications are more frequent [ 13,141. Another potential application for the VHD is in patients who have angioplasty after thrombolysis. Although this is not a frequent association after the publication of the TAMI- 1, TIMI 11, and European Cooperative studies [ 10-121, the complications related to significant bleeding at the arterial puncture site were extremely high in these trials, ranging from 10% to 18%. CONCLUSIONS
This vascular hemostatic device can achieve hemostasis with shorter compression time than conventional manual compression. The placement of the collagen on the exterior of the artery did not produce luminal compromise or reduction of distal circulation. This device may be a useful clinical tool for decreasing the risk of vascular complications after percutaneous procedures. ACKNOWLEDGMENTS
The authors are deeply grateful to Renee Hill for her excellent technical assistance. REFERENCES I . Lozner EC. Johnson LW, Johnson S. et al.: Coronary arteriography 1984-1987: A report of the Registry of the Society for Cardiac Angiography and interventions. 11. An analysis of 218 deaths related to coronary arteriography . Cathet Cardiovasc Diagn 17:11-14, 1989.
2. Block PC, Ockene I, Goldberg RJ, et al.: A prospective randomized trial of outpatient versus inpatient cardiac catheterization. N Engl J Med 319:1251-1255, 1988. 3. Kern MJ, Cohen M, Talley JD, et al.: Early ambulation after 5 french diagnostic cardiac catheterization: results of a multicenter trial. J Am Coll Cardiol 15:1475-1483, 1990. 4. Pink S. Fiutowski L. Gianelly RE: Outpatient cardiac catheterizations: Analysis of patients requiring admission. Clin Cardiol 1:375-378. 1989. 5 . Johnson LW, Lozner EC, Johnson S, et at.: Coronary arteriography 1984-1987: A report of the Registry of the Society for Cardiac Angiography and Interventions. I. Results and complications. Cathet Cardiovasc Diagn 17:5-10, 1989. 6. Wyman RM. Safian RD, Portway V, Skillman JJ. McKay RG. Baim DS: Current complications of diagnostic and therapeutic cardiac Catheterization. J Am Coll Cardiol 12:1400-1406, 1988. 7. Muller DWM, Podd J , Shamir KJ: Vascular access site complications in the era of complex percutaneous coronary interventions. (abstr). Circulation 82(Suppl II1):111-510. 1990. 8. Lemarbre L, Hudon G, Coche G, Bourassa MG: Outpatient peripheral angioplasty: Survey of complications and patients’ perceptions. Am J Radio1 148:1239-1240, 1987. 9. Folland ED, Oprian C, Giacomini J, et al.: VA Cooperative Study on Valvular Heart Disease. Complications of cardiac catheterization and angiography in patients with valvular heart disease. Cathet Cardiovasc Diagn 17:15-21, 1989. 10. Topol El, Califf RM, George BS, et al.: and the TAM1 Study Group. A randomized trial of immediate vs delayed elective angioplasty after intravenous tissue plasminogen activator in acute myocardial infarction. N Engl J Med 317581-588, 1987. 1 I . TIMI Research Group: Immediate vs delayed catheterization and angioplasty following thrombolytic therapy for acute myocardial infarction. JAMA 260:2849-2858, 1988. 12. Simoons ML, Arnold AER, Betriu A, et al.: Thrombolysis with rt-PA in acute myocardial infarction: no beneficial effects of immediate PTCA. Lancet 1:197-203. 1988. 13. Safian RD, Gelbfish JS, Erny RE, Schnitt SJ, Schmidt DA, Baim DS: Coronary atherectomy. Clinical, angiographic, and histological findings and observations regarding potential mechanisms. Circulation 82:69-79, 1990. 14. Hinohara T, Selmon MR. Robertson GC, Braden L. Simpson JS: Directional atherectomy. Circulation 8 I (Suppl IV):IV-79-IV-91. 15. Ernst J. Kloos R , Schrader R, Kaltenbach M. Sigwart U. Sanborn TA: Immediate sealing of arterial puncture sites after catheterization and PTCA using a vascular hemostasis device with collagen: an International Registry. (abstr). Circulation 84:II-68, 1991.
Basic Investigation
Percutaneous Vascular Hemostasis Device for Intervent ional Procedures Alvaro Merino, MD, Catherine Faulkner, RN, Alejandro Corvalan, MD, and Timothy A. Sanborn, MD A new 11.5F over-the-wire vascular hemostasis device was compared to conventional manual compression in normal swine femoral arteries. Using percutaneous techniques, the collagen was deposited and hemostasis achieved in 7 vessels after 1 minute total, plus 4 minutes partial compression, while control manual compression required more than 5 minutes total compression to avoid hematoma formation. One month follow-up of treated arteries (n = 4) and controls (n = 3) showed no impairment in distal pulse or differences in histology at the puncture site in the control and treated arteries. Thus, the vascular hemostasis device technique is safe and effective, achieves hemostasis with less compression time and complications, and does not interfere with arterial wall healing or compromise the lumen. 1992 Wllay-Llsa. Inc
Key words: angiography, angioplasty, normal swine femoral arteries
INTRODUCTION
500 mg of ketamine (Ketasel, Bristol Laboratories) given intramuscularly, and anesthesia was induced with Invasive cardiovascular techniques sustain a small but 200 mg of intravenous pentobarbital with a booster of constant rate of vascular complications which although 130 mg every 45 minutes thereafter. The pig was then not fatal [ 11, can produce significant patient discomfort, intubated and mechanically ventilated with a Harvard and in some cases require blood transfusion or surgical respirator. No anticoagulation was used. Management intervention. Although improvements in catheter and and procedures performed on experimental animals were sheath technology have reduced the complication rate of approved by the Internal Review Board of the Institution, the percutaneous approach and even permitted outpatient and conformed to the position of the American Heart catheterization [3-5 J, vascular complications related to Association on Research Animal Use. hemostasis ranged from 4% to 12% in several recent studies [2,6-91. In addition, interventional techniques Vascular Hemostasis Device Technique performed after thrombolysis, or requiring greater size The hemostasis device (Datascope, Oakland, NJ) concatheters as with atherectomy, have been associated with sists of three parts (Fig. 1): a blunt tip dilator, an 11.5F higher complication rates [6,7,10-141. Thus, a safe and sheath, and 50 mg of collagen material positioned at the effective technique for reliably obtaining hemostasis proximal end of a cartridge. The procedure for placing could decrease the patient discomfort of conventional manual compression, permit earlier ambulation, and reduce the risk of vascular complications. From the Division of Cardiology, Department of Medicine and DeA novel vascular hemostasis device (VHD) for the partment of Pathology, Mount Sinai Medical Center, New York; Datapercutaneous deposition of collagen at the arterial punc- scope Corp., Oakland, NJ, in association with the New York Cardiac ture site was applied after percutaneous sheath insertion Center, Englewood Cliffs, NJ. in normal swine femoral arteries and compared to conReceived December 16, 1991; revision accepted March 1 I . 1992. ventional manual compression. The feasibility, safety, and efficacy of the technique were determined. The ad- Address reprint requests to Timothy A . Sanborn, M.D., Cardiology aptation of hemostatic material to the arterial surface and Division, Starr 4, New York Hospital-Cornell Medical Center, 525 E. 68th Street, New York, NY 10021. the healing process were studied by histology. MATERIALS AND METHODS Animal Model
A total of eight normal Yorkshire albino pigs (aged 3-5 months; weight 30-50 kg) were sedated with 0 1992 Wiley-Liss, Inc.
Presented as an abstract at the 64th annual scientific sessions of the American Heart Association, Anaheim, CA, November 1991. Dr. Merino is the recipient of an NIH-Fogarty International Fellowship Award. Dr. Sanborn is the Arthur Ross Scholar in Cardiovascular Medicine. Supported in part by a grant from Datascope Corp., Oakland, NJ.
320
Merino et al.
Fig. 1. Vascular hemostasis device: (Top) collagen loaded cartridge, (Middle) cartridge in sheath, (Bottom) blunt dilator over 0.035 inch guidewire.
the device consists of two independent operations which are required to achieve proper collagen placement and hemostasis. First, a 6F sheath (USCI, Billerica, MA), which had previously been implanted into the femoral artery, was removed over a 0.035" guidewire while hemostasis was maintained by manual compression of the artery. Then, the 11.5F dilator and the sheath were introduced over the guidewire up to the arterial puncture site until resistance was encountered (Fig. 2A). The guidewire and the dilator were then removed while maintaining total arterial compression. The collagen loaded cartridge was placed into the proximal end of the sheath and the collagen was advanced and pushed out of the sheath toward the puncture site (Fig. 2B). The sheath was held in place, and then slowly pulled back as the cylinder of collagen was discharged. After I minute of total manual compression, the sheath was removed and gentle upstream compression was maintained for another 4 minutes. After 5 minutes, all compression ceased and hemostasis was assessed (Fig. 2C). Acute Studies
First, in order to visualize the sequence and hemostatic function of the technique most completely, 5 femoral arteries were exposed by surgical dissection and canulated by Seldinger technique with a 6F sheath. Then, the hemostasis device was exchanged over a 0.035" guidewire for the original 6F sheath at the puncture site to assess the feasibility of the technique. In another 3 arteries, a 6F sheath was placed percutaneously in the femoral artery, the hemostasis device was applied, and hemostasis was achieved. Then, the animals were sacrificed with an overdose of pentobarbital and the artery was removed, rinsed, and stored in glutaraldehyde-formaldehyde for histological analysis. Chronic Study The arterial healing process was studied in 4 animals. After percutaneous femoral artery cannulation with a 6F
COMMON'FEMORAL
COLLAGEN
COMMON FEMORAL
ARTERY Fig. 2. Technique for the application of the vascular hernostasis device. See text for explanation.
sheath, the VHD was placed in 4 arteries, with another 3 vessels serving as control. One femoral artery could not be successfully cannulated with the 6F sheath, and therefore was excluded from analysis. The animals were allowed to recover from anesthesia and were followed with visual inspection of the inguinal area, and distal pulses were assessed after I month. The animals were sacrificed as described above and the femoral arteries were removed, rinsed, and stored in glutaraldehyde-formaldehyde for histological study. RESULTS Acute Study
With the artery exposed, the technique was found to be reproducible and feasible in five attempts. There were no protrusions of the dilator into the arterial lumen. In all five cases, the collagen material was easily advanced to the surface of the artery without introducing it into the vessel. In contact with blood, the collagen was transformed into a gelatinous mass that spread over the punc-
Percutaneous Vascular Hemostasis Device
321
ture site producing a seal of the arteriotomy. Percutaneous placement of the VHD was also easily performed in three vessels. The only technical requirement was that the track through the skin and subcutaneous tissue had to be enlarged with a hemostat prior to initial needle puncture in order to accept the device’s 11.5F sheath. No hematoma was detected after 1 minute total and 4 minutes partial compression in the treated animals. Macroscopic analysis demonstrated precise placement of the collagen material at the puncture site without protrusion of the collagen into the arterial lumen. Chronic Study No hematoma developed in four device-treated arteries after 1 minute total and 4 minutes partial compression, contrary to three control vessels that required more than 5 minutes total compression to achieve hemostasis without hematoma formation. At 1 month follow-up, no encapsulation, foreign body reaction, or infection was found at the puncture site. The distal pulses were normal. When surgical dissection was performed to examine the arteries, minimal fibrous scar tissue was found on the arterial surface, which was indistinguishable in control and treated animals. Furthermore, there was no evidence of thrombosis in the arterial lumen. Histological analysis of the puncture site showed an intact lumen, normal intimal and medial layers, and a fibrous adventitial cap. At the puncture site, an increase in collagen fibers was observed at the external part of the tunica media in both control and treated vessels (Fig. 3A,B). DISCUSSION Device Feasibility and Efficacy In this preclinical evaluation, a new vascular hemostatic device for percutaneous procedures was tested and found to be easy to use by persons experienced with conventional catheterization technique. The device achieved hemostasis in less than 5 minutes compression, without producing hematomas or compromising the arterial lumen or distal circulation. Histological sections from both acute and chronic studies demonstrated the patency of the artery in all the cases. In histological analysis after 1 month follow-up, total absorption of the collagen on the arterial surface was noted, with normal intimal and medial layers and no differences in the healing response between control and treated vessels. Safety In this initial evaluation, tactile feedback was used to detect resistance as the dilator and sheath were advanced to contact the artery. Using this tactile sense as a guide, no protrusion of the collagen into the arterial lumen was observed on gross inspection. In order to further decrease
Fig. 3. Micrographs of swine femoral artery, 1 month after percutaneous cannulation with a 6F sheath. A: Control artery. Hemostasis was achieved with conventional manual compression. A fibrous cap is seen surrounding the artery. lntimal and medial layers are intact. 8 : Treated artery. The vascular hemostasis device was applied. Fibrous tissue is seen covering the puncture site. lntimal and medial layers are preserved. Trichrome stain, x 10.
the risk of accidental injection of the collagen into the artery, the depth of the artery at the time of the initial arterial puncture can be marked on the percutaneous needle at the level of the skin entry site. Newer equipment intended for human use will have color coded markings on the external surface of the sheath to facilitate the assessment of the depth of the artery and thus permit collagen placement precisely on the puncture site. This is the major advantage of this system, because the undesirable introduction of a significant amount of collagen into the artery would almost certainly lead to vessel occlusion. Although a possible complication, infection of the collagen material at the puncture site was not present in any case at 1 month follow-up in our study, nor has it been reported in ongoing clinical trials [ 151.
322
Merino et al.
Potential Clinical Applications
Routine use of the vascular hemostatic device after cardiac catheterization could certainly reduce the percentage of bleeding complications, as well as the arterial compression time. But the advantages of the VHD will be best demonstrated when used after interventional techniques, especially after coronary atherectomy, in which up to 11F guiding catheters are required and vascular complications are more frequent [ 13,141. Another potential application for the VHD is in patients who have angioplasty after thrombolysis. Although this is not a frequent association after the publication of the TAMI- 1, TIMI 11, and European Cooperative studies [ 10-121, the complications related to significant bleeding at the arterial puncture site were extremely high in these trials, ranging from 10% to 18%. CONCLUSIONS
This vascular hemostatic device can achieve hemostasis with shorter compression time than conventional manual compression. The placement of the collagen on the exterior of the artery did not produce luminal compromise or reduction of distal circulation. This device may be a useful clinical tool for decreasing the risk of vascular complications after percutaneous procedures. ACKNOWLEDGMENTS
The authors are deeply grateful to Renee Hill for her excellent technical assistance. REFERENCES I . Lozner EC. Johnson LW, Johnson S. et al.: Coronary arteriography 1984-1987: A report of the Registry of the Society for Cardiac Angiography and interventions. 11. An analysis of 218 deaths related to coronary arteriography . Cathet Cardiovasc Diagn 17:11-14, 1989.
2. Block PC, Ockene I, Goldberg RJ, et al.: A prospective randomized trial of outpatient versus inpatient cardiac catheterization. N Engl J Med 319:1251-1255, 1988. 3. Kern MJ, Cohen M, Talley JD, et al.: Early ambulation after 5 french diagnostic cardiac catheterization: results of a multicenter trial. J Am Coll Cardiol 15:1475-1483, 1990. 4. Pink S. Fiutowski L. Gianelly RE: Outpatient cardiac catheterizations: Analysis of patients requiring admission. Clin Cardiol 1:375-378. 1989. 5 . Johnson LW, Lozner EC, Johnson S, et at.: Coronary arteriography 1984-1987: A report of the Registry of the Society for Cardiac Angiography and Interventions. I. Results and complications. Cathet Cardiovasc Diagn 17:5-10, 1989. 6. Wyman RM. Safian RD, Portway V, Skillman JJ. McKay RG. Baim DS: Current complications of diagnostic and therapeutic cardiac Catheterization. J Am Coll Cardiol 12:1400-1406, 1988. 7. Muller DWM, Podd J , Shamir KJ: Vascular access site complications in the era of complex percutaneous coronary interventions. (abstr). Circulation 82(Suppl II1):111-510. 1990. 8. Lemarbre L, Hudon G, Coche G, Bourassa MG: Outpatient peripheral angioplasty: Survey of complications and patients’ perceptions. Am J Radio1 148:1239-1240, 1987. 9. Folland ED, Oprian C, Giacomini J, et al.: VA Cooperative Study on Valvular Heart Disease. Complications of cardiac catheterization and angiography in patients with valvular heart disease. Cathet Cardiovasc Diagn 17:15-21, 1989. 10. Topol El, Califf RM, George BS, et al.: and the TAM1 Study Group. A randomized trial of immediate vs delayed elective angioplasty after intravenous tissue plasminogen activator in acute myocardial infarction. N Engl J Med 317581-588, 1987. 1 I . TIMI Research Group: Immediate vs delayed catheterization and angioplasty following thrombolytic therapy for acute myocardial infarction. JAMA 260:2849-2858, 1988. 12. Simoons ML, Arnold AER, Betriu A, et al.: Thrombolysis with rt-PA in acute myocardial infarction: no beneficial effects of immediate PTCA. Lancet 1:197-203. 1988. 13. Safian RD, Gelbfish JS, Erny RE, Schnitt SJ, Schmidt DA, Baim DS: Coronary atherectomy. Clinical, angiographic, and histological findings and observations regarding potential mechanisms. Circulation 82:69-79, 1990. 14. Hinohara T, Selmon MR. Robertson GC, Braden L. Simpson JS: Directional atherectomy. Circulation 8 I (Suppl IV):IV-79-IV-91. 15. Ernst J. Kloos R , Schrader R, Kaltenbach M. Sigwart U. Sanborn TA: Immediate sealing of arterial puncture sites after catheterization and PTCA using a vascular hemostasis device with collagen: an International Registry. (abstr). Circulation 84:II-68, 1991.
