The techniques and tools for percutaneous removal of

Initial Experience With Larger Laser Sheaths for the Removal of Transvenous Pacemaker and Implantable Defibrillator Leads Laurence M. Epstein, MD; Charles L. Byrd, MD; Bruce L. Wilkoff, MD; Charles J. Love, MD; T. Duncan Sellers, MD; David L. Hayes, MD; Christopher Reiser, PhD Background In a previous randomized trial, the 12F laser sheath removed pacing leads via the implant vein more successfully than traditional mechanical tools alone. Two larger sizes of laser sheath, the 14F and 16F models, were developed to extract defibrillator leads and large-diameter pacing leads implanted for the chronic. These devices use pulsed ultraviolet laser light to core though fibrotic tissue grown over the lead body to free the lead from the vasculature. A mandatory prospective registry studied the safety and effectiveness profiles of the larger laser sheaths vis-à-vis the 12F laser sheath. Methods and Results In this study, 863 patients underwent extraction of 1285 leads at 52 sites. Patients treated with the 14F device tended to have older leads than the 12F population; the 16F population, which comprised mostly defibrillator patients, were younger, had younger leads, and were more often male than the 12F population. Clinical success (extracting the entire lead or the lead body minus the distal electrode) was observed in 91% to 92% of cases for all device sizes. The overall complication rate was 3.6%, with 0.8% perioperative mortality. Incidence of complications was independent of laser sheath size. Conclusions The 14F and 16F laser sheaths offer an extraction option for larger long-term transvenous pacemaker and defibrillator leads that is as safe and effective as the 12F laser sheath. (Circulation. 1999;100:516-525.) Key Words: heart-assist device pacemakers lasers defibrillation The techniques and tools for percutaneous removal of transvenous leads have undergone considerable development over the past 2 decades. The use of locking stylets and telescoping sheaths to free transvenous leads from encapsulating scar tissue has become standard. 1 Recently, a randomized trial compared the use of standard techniques to the 12F laser sheath for removal of chronic transvenous pacemaker leads. 2,3 Use of the laser sheath resulted in a significantly higher success rate. A major limitation of this technique was the small size of the 12F laser sheath, which did not accommodate larger transvenous pacemaker leads and implantable cardioverter-defibrillator (ICD) leads. Although transvenous pacemaker leads have decreased in diameter over time, there are still a significant number of older, larger leads in the general population. In addition, the results of recently completed trials have expanded the indication for and may dramatically increase the implantation of ICDs. Physicians will increasingly be faced with the prospect of removing these larger transvenous leads. In this study, we report on the initial experience with larger, 14F and 16F, laser sheaths for extraction of chronic transvenous leads. Methods Patients with chronic transvenous leads of 1-year implantation duration were eligible for this prospective registry. Inclusion criteria required that a lead be accessible from the subclavian, internal or external jugular, or cephalic vein; the patient be able to give informed written consent; mandatory or necessary indications for lead removal existed (as described in Reference 1); all necessary extraction equipment be present; and cardiothoracic surgical backup be available. Exclusion criteria included the inability to use fluoroscopy, a recent history of pulmonary embolus, an unacceptable risk for emergent thoracotomy, no lead in the generator pocket, and a lead too large for the largest laser sheath. The 40-cm working section of the laser sheath consisted of thin inner and outer polymer walls between which a layer of optical fibers had been spirally wrapped. 4 At the distal end of the sheath, the fibers presented a single circumferential ring of light sandwiched between the inner and outer walls of the tip. At the proximal end of the sheath, the fibers passed through a connecting cable to the XeCl excimer laser (CVX-300, Spectranetics Inc). The excimer laser emitted 135-ns pulses of ultraviolet light (308-nm wavelength) at a repetition rate of 40 Hz. The fluence (output energy per unit area of fiber) at the distal tip of the device was set to 60 mj/mm 2. The laser-tissue interaction consisted of a combination of photochemolysis and photothermal ablation, which caused the layer of tissue immediately Received December 11, 1998; revision received May 5, 1999; accepted May 5, 1999. From the Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Mass; Broward General Medical Center, Fort Lauderdale, Fla; the Cleveland Clinic Foundation, Cleveland, Ohio; Ohio State University, Columbus, Ohio; Memorial Hospital, Colorado Springs, Colo; Mayo Clinic and Mayo Foundation, Rochester, Minn; and Spectranetics Corporation, Colorado Springs, Colo. Correspondence to Laurence M. Epstein, MD, Cardiovascular Division, Beth Israel Deaconess Medical Center, East Campus, 330 Brookline Ave, Boston, MA 02215. E-mail lepstein@bidmc.harvard.edu 1999 American Heart Association, Inc. Circulation is available at http://www.circulationaha.org 516

Epstein et al Larger Laser Sheaths 517 TABLE 1. Patient Characteristics 14F Sheath 16F Sheath 12F Sheath Patients, n 248 177 438 Leads, n 413 201 671 Age (range), y 64 18 (4 93) 61 17 (9 87)* 64 18 (7 103) Male, n (%) 157 (63) 140 (79) 247 (56) Indication for extraction, % Sepsis 10 11 10 Endocarditis 3 6 5 Pocket infection 23 26 24 Nonfunctioning lead 50 52 38 Patient morbidity 20 28 38 Implant duration (range), mo 83 50 (2 365)* 63 56 (2 277)* 79 47 (3 285) Location, n (%) Ventricular 240 (58) 174 (87)* 360 (54) Atrial 173 (42) 26 (13)* 307 (46) Coronary sinus 0 (0) 1 (0) 0 (0) Fixation, n (%) Active 124 (30)* 34 (17)* 255 (38) Passive 249 (60)* 140 (70)* 380 (57) Unknown/none 40 (10)* 27 (13)* 36 (5) Manufacturer, n (%) Medtronic 192 (46)* 73 (36) 199 (30) Pacesetter 67 (16) 1 (0)* 88 (13) CPI/Guidant 24 (6) 103 (51)* 48 (7) Telectronics 39 (9)* 4 (2)* 202 (30) *P 0.05 vs control. in contact with the device tip to disintegrate into particles typically 5 m in diameter. 5 Because the penetration depth of 308-nm light in vascular tissue is 100 m, the laser light is completely absorbed by the tissue immediately in contact with the tip. This produces controlled and precise removal of only the encapsulating fibrous tissue directly surrounding the lead body that is in contact with the tip of the laser sheath. The internal and external diameters of the 14F and 16F laser sheaths are 10.2/14.5F and 12.5/16.8F, respectively. In a typical procedure, the pocket was opened, and the generator (pacemaker or ICD) was removed if present. The lead(s) was then dissected free from the scar tissue in the pocket, and a locking stylet was placed in the lead if possible. In most cases, a polymer outer sheath was preloaded over the laser sheath before the stylet and lead were threaded through the assembly. The laser and outer sheaths were passed over the lead body until the first binding site was reached. Excimer laser energy (5-second bursts) combined with gentle advancement pressure on the laser sheath and withdrawal traction on the locking stylet resulted in ablation of the encapsulating tissue and allowed the sheaths to advance to the next binding site. The sheath assembly was advanced over the lead until the lead was freed from all binding tissue or until the sheath tip reached a point a few millimeters from the heart wall. In the latter case, the outer sheath was advanced, and countertraction was applied to remove the lead. Anticoagulation if present was stopped before the procedure, and intraoperative heparin was not administered because of the risk of potential bleeding complications. The primary end point was complete removal of the lead via the implant vein. The secondary end point was partial lead removal, leaving behind only the electrode with or without a short segment of conductor coil. Clinical success resulted when either the primary or secondary end point was reached. Procedure failure was defined as failure to extract the lead, the occurrence of a complication, or abandonment of a superior approach for a femoral or thoracic approach. Because no conventional telescoping sheaths were available to remove the largest of the leads in this study, a randomized trial of larger laser sheaths versus conventional techniques, as in the Pacemaker Lead Extraction with the Excimer Sheath (PLEXES) trial, 3 was not undertaken. After completion of the PLEXES trial, all subsequent patients undergoing extraction with all sizes of laser sheath were prospectively tracked in a registry. Registry patients treated with the 12F device were used as a control group to evaluate registry experience with the larger sheaths. All subjects were enrolled after granting informed written consent at sites with institutional review board approval of the study. Patient rights were safeguarded according to the Declaration of Helsinki. Data were recorded on paper forms and forwarded to the data coordination center for computerized statistical analysis (SAS/Stat, SAS Institute). A short follow-up questionnaire was completed 1 month after the procedure after either a clinical visit or telephone contact with the patient. Results are presented as mean SD. During data analysis, means of continuous variables were compared by use of a t test at 95% CIs, whereas differences in categorical variables were significant if a 2 test yielded P 0.05. Results From October 1996 until August 1998, 863 patients underwent extraction of 1285 leads at 52 sites by use of a laser sheath. Patient and lead characteristics are given in Table 1. Extraction was attempted in 248 patients with 413 leads in the 14F group, 177 patients with 201 leads in the 16F group, and 438 patients with 671 leads in the 12F group. The mean age

518 Circulation August 3, 1999 TABLE 2. Results 14F Sheath 16F Sheath 12F Sheath Leads, n 413 201 671 Complete success, n (%) 357 (86) 180 (90) 596 (89) Partial success, n (%) 19 (5) 4 (2) 20 (3) Failure, n (%) 37 (9) 17 (8) 55 (8) Procedure time (range), min 13 21 (1 270) 15 25 (1 195) 13 23 (1 260) Patients, n 248 177 438 Complications, n (%) 11 (6) 10 (6) 11 (3) Perioperative deaths, n (%) 4 (1.6) 1 (0.6) 2 (0.5) of the patients was 64 18, 61 17, and 64 18 years for the 14F, 16F, and 12F groups, respectively, with the 16F group slightly but significantly younger than the 12F and 14F groups. Most patients were male in all groups, and the mean implant duration was 83 50, 63 56, and 79 47 months for the 14F, 16F, and 12F groups, respectively, with the 14F group having a significantly longer and the 16F group having a significantly shorter implant duration than the 12F group. More than 1 indication for extraction could be present in a given patient. Indications most often involved infection, nonfunctioning leads, or patient morbidity, which referred to any situation in which the investigator felt that leaving the lead in place subjected the patient to significant morbidity. Recalled leads fell into this category. Although most leads were ventricular for the 14F and 16F groups (58% and 87%), they were nearly evenly split in the 12F group (54% ventricular). In addition, most leads had passive fixation in all groups, but a significantly higher percentage of active fixation leads were found in the 12F group (30%, 17%, and 38% for the 14F, 16F, and 12F groups, respectively). The differences in lead manufacturers were due mostly to a significantly higher percentage of CPI/Guidant leads in the 16F group and Telectronics leads in the 12F group. These differences can be accounted for by the use of the 16F sheath to extract ICD leads (117 patients with 128 leads) and the 12F sheath to extract Accufix (Telectronics) leads. The complete and partial success rates were similar for all 3 groups (Table 2). In the 14F group, the complete and partial success rates were 86% and 5%, for an overall clinical success rate of 91%. For the 16F group, the results were 90% and 2%, for an overall clinical success rate of 92%. Finally, in the 12F group, 89% of leads were completely removed and 3% were partially removed, for an overall clinical success rate of 92%. In some cases, initial sheath size did not allow successful extraction, and upsizing to a larger sheath was required. A 14F sheath was used for 22 leads that were initially treated with a 12F sheath. Additionally, there were 3 instances of upsizing from a 12F to a 16F sheath and 12 instances of upsizing from a 14F to a 16F sheath. These cases were classified according to the largest laser sheath used. A fluoroscopic image from a typical extraction can be seen in Figure 1. The 16F sheath had been advanced over the proximal portion of the distal shocking coil of an ICD lead. Investigators were not asked to provide information on alternative approaches when laser extraction was unsuccessful. Although this information would have been valuable, it is unavailable. Figure 1. Anterior-posterior fluoroscopic image from typical lead extraction. A 16F laser sheath can be seen over proximal portion of distal shocking electrode of ICD lead.

Epstein et al Larger Laser Sheaths 519 TABLE 3. Follow-Up at 1 Month 14F Sheath 16F Sheath 12F Sheath Patients, n 244 177 438 Follow-up received, n (%) 200 (82) 143 (81) 357 (82) Any late complication, n (%) 8/200 (4.0) 1/143 (0.7) 5/357 (1.4) Death at 1 month, n (%) 3/200 (1.5) 0 4/357 (1.1) Although a high success rate was achieved, use of the laser did not eliminate the significant complications associated with transvenous lead extraction. Eleven (4%), 10 (6%), and 11 (3%) patients suffered significant complications associated with death in 4, 1, and 2 patients in the 14F, 16F, and 12F groups, respectively (Table 2). Cardiac tamponade was the most common complication. occurring in 13 patients. Additional acute complications included hemothorax caused by vascular perforation above the pericardial reflection, air embolus, myocardial avulsion, and vascular avulsion. The most common vascular injury was perforation of the superior vena cava (5 total), which occurred during attempts to reimplant new leads after extraction. Complication rates for atrial (2.8%) and ventricular (3.2%) leads were similar (P 0.79). In addition, there did not appear to be a significantly increased risk of complication in the cases in which upsizing of the laser sheath was required (5.4% with versus 3% without upsizing, P 0.71), although the number of observations is small, giving low statistical power to this comparison. Follow-up forms were received for 82% of patients overall, as shown in Table 3. The most common complications observed at follow-up were vein thrombosis and arm swelling (7 patients total). Pocket hematoma was observed in 2 patients, and pericardial effusion without sequelae was seen in another 2 patients. A total of 7 patients had died at the time of follow-up, all from comorbid conditions. Because the follow-up was short, late infections would not be captured by this study. There were no significant differences between groups in follow-up observations. Discussion This is the first full report of the use of laser sheaths to remove larger long-term transvenous pacemaker and ICD leads. The overall clinical success rate was 90% for all groups, in concert with preliminary experience. 6 There were no significant differences in success or complications for the 3 sheath sizes used in this study. The differences in patient and lead characteristics between the groups are due to the size of various leads. Larger ICD leads require the 16F sheath for extraction. Therefore, differences between this group and the others would be expected to reflect the differences between pacemaker and ICD patient populations. ICD patients are more often male, are more likely have ventricular leads, and are younger than the mean for pacemaker patients. Because transvenous ICD leads were introduced in the early 1990s, immediately before this study, the implant duration is shorter than for pacing leads. In the 14F group, the implant duration was significantly longer than for the other groups, probably because the older transvenous Figure 2. Photograph of 25-year-old biaxial pacemaker lead after extraction. Note large fragment of calcified fibrosis adherent to lead (arrow). 16F sheath was required to encompass both lead and fibrotic tissue. pacing leads were significantly larger than current leads (see Appendix). In many cases, these older leads will not fit within a 12F sheath and required the 14F sheath for extraction. A higher percentage of leads in the 12F group had active fixation because of the concomitant recall of Telectronics Accufix leads during the registry period. Despite these differences, the results were uniform with regard to efficacy and safety, suggesting that the laser sheath can be applied to a wide range of transvenous leads requiring extraction. The need for larger laser sheaths was not limited to larger leads. In some cases, the advancement of the sheath resulted in snowplowing of the encapsulating fibrous tissue or lead insulation, leading to an inability to advance the sheath. In rare cases, calcified fibrosis prevented sheath advancement. The larger diameter of the 14F and 16F sheaths can allow sheath advancement around the obstruction, with subsequent successful extraction. An example of this technique is shown in Figure 2, in which a 25-year-old biaxial transvenous lead was extracted with the 16F laser sheath. Note the large piece of calcified fibrosis adherent to the lead remnant.

520 Circulation August 3, 1999 Regardless of technique, transvenous lead extraction carries a small but significant risk of serious complications. Cardiac perforation or tear and vascular damage are the most common serious complications. In this study, the overall acute complication rate was 3.6% per patient, or 2.5% per lead; total perioperative mortality was 0.8%. These frequencies are very close to expectations for lead removal. 7,8 A significant number of complications were not related to the extraction procedure directly but were associated with lead reimplantation. It is unclear whether the laser sheath makes the vascular wall more susceptible to perforation. However, this complication can be avoided by using care and a long peel-away introducer to implant a new lead into the channel vacated by the extracted lead. Given the risk of life-threatening complications, lead extractions should be performed only with appropriate equipment and personnel required to address all potential situations, including thoracotomy, sternotomy, and cardiopulmonary bypass. Previous Studies In a recently reported randomized trial, the 12F laser sheath was successful in completely removing 230 of 244 (94%) of leads and partially removing an additional 6 (2.5%), for an overall clinical success of 96.5%. 3 Clinical success in the present study was slightly lower at 91% and 92% for the 14F and 16F leads, respectively. In addition, the success rate for the 12F registry was 92%. The lower overall success rate may reflect several factors. The randomized trial included only 9 investigators experienced in lead extraction, whereas the present study included 52 sites with investigators having a wide range of experience. All patients meeting the inclusion criteria for lead explant at participating sites were randomized in the previous trial, including the leads easily removed with merely a few moments of gentle traction. Such patients were not included in this registry because the laser was not used; this biases the registry toward more difficult cases. Mean implant duration in the randomized study was 65 months, significantly shorter than for the 12F and 14F groups reported here. Longer implant duration is typically associated with lower explant success. 7 Lead populations also differed between the randomized trial and this registry. Study Limitations At participating sites, it was not mandatory to use the laser sheath on patients presenting for lead explant. Patients treated with other means or referred to surgery were not followed up in this study. It is not possible to determine from the data collected how representative of the total pacing and ICD population this registry might be. Limited follow-up was performed in this study. Observation of unanticipated longerterm sequelae of laser sheath usage remains an unanswered question. This study was undertaken to define the value of a lead extraction tool. Additional study is required to reassess the clinical indications for lead removal and to help balance the risk of lead removal and its benefits. Conclusions Investigators chose laser sheath size according to the size of the lead selected for explant (Appendix) Accordingly, lead descriptions and patient populations varied slightly for each laser sheath size. Despite these differences, the rate of clinical success and the incidence of complications were independent of laser sheath size. The 14F and 16F laser sheaths are as safe and effective as the 12F device. Because complications can be life-threatening, prompt surgical backup is mandatory for lead extraction procedures. References 1. Byrd CL, Schwartz SJ, Hedin N. Lead extraction: indications and techniques. Cardiol Clin. 1992;10:735 748. 2. Byrd CL. Extracting chronically implanted pacemaker leads using the Spectranetics excimer laser: initial clinical experience. Pacing Clin Electrophysiol. 1996;19(suppl II):567. Abstract. 3. Wilkoff BL, Byrd CL, Love CJ, Hayes DL, Sellers TD, Schaerf RH, Parsonnet V, Epstein LM, Sorrentino RA, Reiser C. Pacemaker lead extraction with the laser sheath: results of the Pacing Lead Extraction With the Excimer Sheath (PLEXES) trial. J Am Coll Cardiol. 1999;33:1671 1676. 4. Reiser C, Taylor K, Lippincott R. Large laser sheaths for pacing and defibrillator lead removal. Lasers Surg Med. 1998;22:42 45. 5. Cross FW, Bowker TJ. The physical properties of tissue ablation with excimer lasers. Med Instrum. 1987;21:226 230. 6. Wilkoff BL, Byrd CL, Sellers TD, Schaerf RH, Reiser C. Transvenous lead extraction: PLEXES trial results for larger laser sheaths. Circulation. 1997;96(suppl I):I-695. Abstract. 7. Smith HJ, Fearnot NE, Byrd CL, Wilkoff BL, Love CJ, Sellers TD. Five-years experience with intravascular lead extraction. Pacing Clin Electrophysiol. 1994;17:2016 2020. 8. Wilkoff BL, Byrd CL, Love CJ, Sellers TD, Reeves RC, Kutalek SP, Turk KT, Crevey BJ, Young RA, Van Zandt HJ. Risks of intravascular extraction of chronic pacemaker and ICD leads: a multicenter analysis of 1895 patients. Pacing Clin Electrophysiol. 1998;21(suppl II):826. Abstract.

Epstein et al Larger Laser Sheaths 521 Appendix. Leads Requiring 14F or 16F Laser Sheath Manufacturer Model No. Name OD, mm OD, F Sheath, F American Pacemaker Corp 3179 3.3 9.9 16 3180 3.3 9.9 16 3193 3.3 9.9 16 212-600 3.3 9.9 16 214-612 3.3 9.9 16 Biocontrol Technology/Coratomic BL-11 Low-Flex 3.3 9.9 16 L-40 EndoLoc 2.9 8.7 14 Biotronik JP45-BP JP 2.6 7.8 14 JP53-BP JP 2.6 7.8 14 PX45-JBP PolyRox 2.6 7.8 14 TIJ53-BP TIJ 2.6 7.8 14 Cardiac Control Systems AT-332 PolySafe A-track 3.3 9.9 16 AT-333 PolySafe A-track 3.3 9.9 16 AT-334 PolySafe A-track 3.3 9.9 16 AT-342 PolySafe A-track 3.3 9.9 16 AT-343 PolySafe A-track 3.3 9.9 16 AT-442 PolySafe A-track 3.3 9.9 16 AT-443 PolySafe A-track 3.3 9.9 16 AT-444 PolySafe A-track 3.3 9.9 16 CPI-Guidant 20 SVC 3.2 9.6 16 30 K 54 3 9 16 40 A 67 3.3 9.9 16 41 L 67 3.3 9.9 16 60 Endotak C 3.95 11.85 16 62 Endotak C 3.95 11.85 16 64 Endotak C 3.95 11.85 16 70 Endotak 70 3.95 11.85 16 72 Endotak C 3.95 11.85 16 74 Endotak C 3.95 11.85 16 4000 SRT 3.2 9.6 16 4001 SRT 3.2 9.6 16 4002 SRT 3.2 9.6 16 4209 3.2 9.6 16 4210 3.2 9.6 16 4211 3.2 9.6 16 4218 3.2 9.6 16 4225 3.2 9.6 16 4226 3.2 9.6 16 4227 3.2 9.6 16 4229 3.2 9.6 16 4230 3.2 9.6 16 4231 3.2 9.6 16 4312 3 9 14 4313 3 9 14 4315 3 9 14 Daig Corp BCT 210 3.3 9.9 16 14 BCT 211 3.3 9.9 16 BCT 211 3.3 9.9 16 BCT 212 3.3 9.9 16 A total of 145 leads required a 14F sheath, and 77 required a 16F sheath.

522 Circulation August 3, 1999 Appendix. Continued Manufacturer Model No. Name OD, mm OD, F Sheath, F BCT 213 3.3 9.9 16 BCT 216 3.3 9.9 16 BCT 217 3.3 9.9 16 Daig/Medcor 6100 2.6 7.8 14 6101 2.6 7.8 14 6200 Microtip 2.6 7.8 14 6201 Microtip 2.6 7.8 14 P56-MTF Microtip 2.6 7.8 14 P65-2 2.6 7.8 14 P65-MTF 2.6 7.8 14 P85-2 2.6 7.8 14 Intermedics Inc 420-01 Biopore TM 3 9 14 420-02 3 9 14 420-03 3 9 14 421-01 Biopore MR 3 9 14 421-02 MR 3 9 14 421-03 Biopore MR 3 9 14 432-01 2.7 8.1 14 432-01T 2.7 8.1 14 432-02 Biopore 2.7 8.1 14 466-01 Lifeline 3.2 9.6 16 476-01 Lifeline TLE 3.2 9.6 16 482-01 483-05 27 8.1 14 483-05 2.7 8.1 14 483-08 2.7 8.1 14 484-01 Lifeline TLE 2.7 8.1 14 490-01 Polyflex 2.7 8.1 14 492-01 Polyflex 2.7 8.1 14 492-02 2.7 8.1 14 492-03 2.7 8.1 14 Medtronic Inc 4001 Spectraflex 2.67 8.01 14 4002 Spectraflex 2.67 8.01 14 4003 CapSure 2.67 8.01 14 4003M CapSure 2.67 8.01 14 4004M CapSure 3 9 14 4012 Target Tip 3 9 14 4016 3.4 10.2 16 4016A 3.4 10.2 16 4057 3 9 14 4057M 3 9 14 4067 CapSureFix 2.7 8.2 14 4058 3 9 14 4058M 3 9 14 4067 CapSureFix 2.7 8.0 14 4068 CapSureFix 2.7 8.2 14 4078 2.6 7.8 14 4082 Target Tip 3 9 14 4502 Spectraflex 2.7 8.0 14 4503 CapSure 2.5 7.6 14

Epstein et al Larger Laser Sheaths 523 Appendix. Continued Manufacturer Model No. Name OD, mm OD, F Sheath, F 4503M CapSure 2.5 7.6 14 4504 CapSure 3 8.9 14 4504M CapSure 3 8.9 14 4512 Target Tip 3 9 14 4557 3 9 14 4557M 3 9 14 4558M 2.7 8.2 14 4582 Target Tip 2.6 7.8 14 5024 CapSure SP 2.8 8.5 14 5024M CapSure SP 2.8 8.5 14 5026 CapSure 3.1 9.2 14 5028 Target Tip 2.8 8.4 14 5032 CapSure VDD 3.3 9.8 16 5032L CapSure VDD 3.3 9.8 16 5032S CapSure VDD 3.3 9.8 16 5034 CapSure Z 2.8 8.4 14 5058 CapSure Fix 2.7 8.2 14 5062 Target Tip 3.1 9.2 14 5064 Target Tip 3.2 9.6 16 5067 CapSureFix 2.7 8.0 14 5068 CapSureFix 2.7 8.2 14 5524 CapSure SP 2.8 8.5 14 5524M CapSure SP 2.8 8.5 14 5534 CapSureZ 2.8 8.4 14 5562 Target Tip 3.3 9.9 16 5568 CapSureFix 2.7 8.2 14 5815A Pediatric 2.7 8.1 14 5816 Stop at Ring 3.8 11.4 16 5818 3.8 11.4 16 5819 3.8 11.4 16 5821 3.8 11.4 16 5824 3.8 11.4 16 5824A 3.8 11.4 16 6901 3.1 9.4 14 6901R 3.1 9.4 14 6902 Tenax 3.2 9.5 16 6904 3.2 9.5 16 6904A 3.2 9.5 16 6905 2.6 7.8 14 6907 2.7 8.1 14 6907R 2.7 8.1 14 6909 2.6 7.8 14 6912 Target Tip 2.9 8.8 14 6917T 2.7 8.2 14 6917AT 2.7 8.2 14 6936 Transvene-RV 3.3 9.9 16 6950 Tenax 3.1 9.4 14 6951 Tenax 2.6 7.8 14 6954 Stop at Tip 3.2 9.6 16 6957 Spectraflex 3.4 10.1 16

524 Circulation August 3, 1999 Appendix. Continued Manufacturer Model No. Name OD, mm OD, F Sheath, F 6957J Spectraflex 3.4 10.1 16 6959 2.8 8.4 14 6961 Tenax 2.7 8.0 14 6962 Tenax 3.1 9.4 14 6971 Spectraflex 2.7 8 14 6972 Spectraflex 2.7 8 14 6990 Spectraflex 3.1 9.4 14 6990U Spectraflex 2.7 8 14 6991 Tenax 3.3 9.9 16 6992 Cornary Sinus 3.1 9.4 14 6992A Cornary Sinus 3.1 9.4 14 6994 3.3 9.9 16 Oscor Medical Corp KY Bi Fixed Screw Silicone 2.7 8.1 14 RX Bi J Silicone 2.7 8.1 14 RX Bi Straight Silicone 2.7 8.1 14 ZYBi Silicone 2.7 8.1 14 ZY J Bi Silicone 2.7 8.1 14 Pacesetter/St. Jude 816 3.3 9.9 16 818 3.2 9.6 16 820 2.9 8.7 14 1018T 2.8 8.4 14 1028T Fast Pass 2.8 8.4 14 1148T 2.8 8.4 14 1188T Tendril 2.7 8.0 14 404B 2.6 7.8 14 Sorin Biomedical Inc S80 T Bi 2.7 8.1 14 S 80 J Bi 2.7 8.1 14 S 83 S Tripolar 2.7 8.1 14 S 83 M Tripolar 2.7 8.1 14 S 83 L Tripolar 2.7 8.1 14 S 100/4 Bi 2.7 8.1 14 S 200B Bi 2.7 8.1 14 S200AB Bi 2.7 8.1 14 Telectronics/St. Jude 030-203 3.2 9.6 16 030-206 3.2 9.6 16 030-209 2.6 7.8 14 030-211 3.2 9.6 16 033-486 2.7 8.1 14 033-486F 2.7 8.1 14 033-488 2.7 8.1 14 033-488F 2.7 8.1 14 321-100A Hi-Flex 2.6 7.8 14 321-100P Hi-Flex 2.6 7.8 14 321-101A Hi-Flex 2.6 7.8 14 321-101P Hi-Flex 2.6 7.8 14 322-153 2.7 8.1 14 322-155 2.7 8.1 14 322-163 2.7 8.1 14 322-164 2.7 8.1 14 322-165 2.7 8.1 14

Epstein et al Larger Laser Sheaths 525 Appendix. Continued Manufacturer Model No. Name OD, mm OD, F Sheath, F 322-366 Uni-Silicone 3 9 14 323-543 2.7 8.1 14 323-551 2.7 8.1 14 324-343 ELWRTE 2.7 8.1 14 324-351 Nine-Turn 2.7 8.1 14 324-443 Nine-Turn 2.7 8.1 14 324-451 Nine-Turn 2.7 8.1 14 324-543 2.7 8.1 14 324-551 ELWRTE 2.7 8.1 14 324-556 ELWRTE 2.7 8.1 14 324-643 ELWRTE(peds) 2.7 8.1 14 324-756 Coronary Sinus 2.6 7.8 14 324-856 2.7 8.1 14 325-156 3.2 9.6 16 325-160 3.2 9.6 16 425-161 3.2 9.6 16 325-162 3.2 9.6 16 328-152 2.6 7.8 14 Vitatron Medical Inc IMP 15Q Brilliant 2.65 7.95 14 IMP 16Q Brilliant 2.65 7.95 14 IMP 17Q Brilliant 2.65 7.95 14