Ethylene oxide on electrophysiology catheters following resterilization: implications for catheter reuse

Reprocessing of electrophysiology material in EHRA countries: an EHRA Young EP survey

Data on reprocessing of electrophysiology (EP) materials are sparse. Reprocessing of catheters and other materials in daily routine varies through countries and may depend on specific material characteristics, supplier, or federal law. The aim of this study was to collect data on reprocessing usage through EHRA countries. An online survey consisting of 27 questions was distributed to EHRA Young EP members and members of national EP working groups. Two hundred and two participants from 34 EHRA countries completed the survey. One hundred and seven respondents (53.0%) reported having used and using reprocessed EP material, 30 (14.9%) respondents have used reprocessed EP material in the past but not at the time of the survey, 65 (32.2%) had never used reprocessed EP material. The most reprocessed EP materials include cables (70%), diagnostic EP catheters with deflectable (64%) or fixed curve (63%), non-irrigated ablation catheters (51%), and other conventional diagnostic catheters (41%). The most durable material was diagnostic EP catheters with a fixed curve (61%), the most sensitive material was ablation catheters with contact force sensors (21%). Important benefits were seen in reducing costs for the providing hospital (65%) and the healthcare provider (42%) and making EP procedures available for a greater number of patients (42%). Main concerns were on quality aspects (58%), contamination (52%), and loss of precision (47%). Reprocessing of EP materials is heterogeneously managed among EHRA countries. The present survey shows that European electrophysiologists consider the use of reprocessed EP material as generally safe and cost-effective.

Guidance on reuse of cardio-vascular catheters and devices in India: A consensus document

Reuse of medical device is accepted worldwide. Benefits of reuse include not only cost saving but a favorable impact on environment. However, certain requirements should be met for reuse to be safe and effective. The devices, which can be reused, should be clearly defined, a meticulous process for dis-infection and sterilization followed and its functionality ascertained before use. Further, an appropriate consent should be obtained where necessary and the cost saving entailed should be directly passed on to the patient.

Sterility and Microbiological Assessment of Reused Single-Use Cardiac Electrophysiology Catheters

Objective.

To assess the performance and limitations of a reprocessing protocol for nonlumen electrophysiology catheters by testing the sterility of reprocessed devices and defining the maximum number of reprocessing cycles sustainable by the device in hygienically safe conditions.

Design.

Simulated use, reprocessing, and testing of the catheters.

Setting.

Microbiology and virology department of a public health diagnostic laboratory.

Interventions.

Seventy-three catheters were collected after clinical use on patients. The first group of devices was tested for sterility after 1 cycle of reprocessing. By the repetition of simulated use (blood inoculated with bacteria) and reprocessing (decontamination, cleaning, and hydrogen peroxide gas plasma sterilization), we obtained 39 sample devices reprocessed 2 times, 26 reprocessed 3 times, 28 reprocessed 4 times, 36 reprocessed 5 times, and 22 reprocessed 6 times. Devices were cultured for 28 days in trypticase soy broth.

Results.

We tested 208 catheters with 6 cycles of reprocessing and 4 inoculated bacteria species. No devices tested positive for the inoculated strains until the fourth cycle of reprocessing. One of 35 catheters showed the growth of the inoculated strain Bacillus subtilis after 5 cycles of reprocessing, and 1 of 22 catheters showed growth of this organism 6 cycles. After the second reprocessing, 7 of 36 devices showed growth of gram-negative bacteria other than the strain inoculated.

Conclusions.

Reprocessing according to the reprocessing protocol was insufficient to guarantee device sterility after 5 reuses. Cleaning with enzymatic solution revealed good cleaning properties with efficient bioburden reduction. Storage intervals of longer than 24 hours during reprocessing should be avoided to limit contamination or bacterial overgrowth. Technical considerations suggest the introduction of reprocessing procedures only in hospitals with considerable workloads.

The cost of open heart surgery in Nigeria

Introduction

Open Heart Surgery (OHS) is not commonly practiced in Nigeria and most patients who require OHS are referred abroad. There has recently been a resurgence of interest in establishing OHS services in Nigeria but the cost is unknown. The aim of this study was to determine the direct cost of OHS procedures in Nigeria.

Methods

The study was performed prospectively from November to December 2011. Three concurrent operations were selected as being representative of the scope of surgery offered at our institution. These procedures were Atrial Septal Defect (ASD) Repair, Off Pump Coronary Artery Bypass Grafting (OPCAB) and Mitral Valve Replacement (MVR). Cost categories contributing to direct costs of OHS (Investigations, Drugs, Perfusion, Theatre, Intensive Care, Honorarium and Hospital Stay) were tracked to determine the total direct cost for the 3 selected OHS procedures.

Results

ASD repair cost $ 6,230 (Drugs $600, Intensive Care $410, Investigations $955, Perfusion $1080, Theatre $1360, Honorarium $925, Hospital Stay $900). OPCAB cost $8,430 (Drugs $740, Intensive Care $625, Investigations $3,020, Perfusion $915, Theatre $1305, Honorarium $925, Hospital Stay $900). MVR with a bioprosthetic valve cost $11,200 (Drugs $1200, Intensive Care $500, Investigations $3040, Perfusion $1100, Theatre $3,535, Honorarium $925, Hospital Stay $900).

Conclusion

The direct cost of OHS in Nigeria currently ranges between $6,230 and $11,200. These costs compare favorably with the cost of OHS abroad and can serve as a financial incentive to patients, sponsors and stakeholders to have OHS procedures done in Nigeria.

Sterilization of bacterial spores by using supercritical carbon dioxide and hydrogen peroxide

It was hypothesized that supercritical carbon dioxide (SC-CO(2)) treatment could serve as an alternative sterilization method at various temperatures (40-105 degrees C), CO(2) pressures (200-680 atm), and treatment times (25 min to 6 h), and with or without the use of a passive additive (distilled water, dH(2)O) or an active additive (hydrogen peroxide, H(2)O(2)). While previous researchers have shown that SC-CO(2) possesses antimicrobial properties, sterilization effectiveness has not been shown at sufficiently low treatment temperatures and cycle times, using resistant bacterial spores. Experiments were conducted using Geobacillus stearothermophilus and Bacillus atrophaeus spores. Spore strips were exposed to SC-CO(2) in commercially available supercritical fluid extraction and reaction systems, at varying temperatures, pressures, treatment times, and with or without the use of a passive additive, such as dH(2)O, or an active additive, such as H(2)O(2). Treatment parameters were varied from 40 to 105 degrees C, 200-680 atm, and from 25 min to 6 h. At 105 degrees C without H(2)O(2), both spore types were completely deactivated at 300 atm in 25 min, a shorter treatment cycle than is obtained with methods in use today. On the other hand, with added H(2)O(2) (<100 ppm), 6 log populations of both spore types were completely deactivated using SC-CO(2) in 1 h at 40 degrees C. It was concluded from the data that large populations of resistant bacterial spores can be deactivated with SC-CO(2) with added H(2)O(2)at lower temperatures and potentially shorter treatment cycles than in most sterilization methods in use today.

Efficiency in endotoxin removal by a reprocessing protocol for electrophysiology catheters based on hydrogen peroxide plasma sterilization

Electrophysiology and ablation cardiac catheters, which come in contact with blood during clinical use, are required to be non-pyrogenic (<20 endotoxin units (EU)/device). This study aimed to quantify the residual endotoxin load in reprocessed devices as a mandatory step to guarantee safe reuse. We monitored the pyrogenic status of the device (n=61) in three fundamental steps of the reprocessing protocol: after clinical use, after decontamination-cleaning treatments and after complete reprocessing, including sterilization by hydrogen peroxide gas plasma. Finally, a depyrogenation test was produced for evaluating the depyrogenation efficiency of the sole hydrogen peroxide sterilization treatment. Results showed that standard clinical use did not represent a source for endotoxin contamination, while the use of tap water and manual cleaning processing could increase the pyrogenic load in a significant way. The introduction of the sterilization by hydrogen peroxide gas plasma resulted in effective reduction of the endotoxin contamination and in safe reprocessing of 15 of 15 clinically used catheters. In addition, tests conducted on in vitro spiked catheters showed that initial pyrogenic loads of 40, 80, 200EU/device were reduced to less than 11EU/device. Depyrogenation testing demonstrated efficiency in endotoxin reduction of more than 62 times (1.8log). These results show the determining role of hydrogen peroxide gas-plasma sterilization in the reduction of pyrogenic load on medical devices. Considering actual hygienic requirements at single-use device reprocessing, hydrogen peroxide gas-plasma sterilization can be considered as an efficient treatment at non-lumen cardiac electrophysiology catheter reprocessing.

Catheter interventions for congenital heart disease in third world countries

The term "Third World" loosely encompasses a group of middle- and low-income countries. Considerable differences exist in health care delivery and health indices among these countries. The vast majority of children in the Third World do not have health insurance for congential heart disease (CHD). Catheter interventions for CHD are expensive because of installation costs of expensive biplane equipment, the requirement of dedicated personnel, and the need to stock a large inventory of expensive hardware. As a result, many catheter intervention procedures are beyond the reach of the average patient in the developing world. The following cost-effective strategies have evolved in selected institutions that have attempted to perform catheter interventions for CHD at an affordable cost: sharing of space, equipment, and support personnel with a busy adult cardiology program; use of single plane equipment; the development of sedation protocols to reduce the need for anesthesiologists; strategies to reduce procedure time; reuse of hardware through ethylene oxide sterilization; improvisations to use adult hardware items for CHD interventions; judicious case selection; and improvised alternatives to occlusive devices. These strategies may help reduce costs and allow a larger proportion of patients in developing countries with CHD to undergo interventions. However, the safety of these strategies and the cost savings need to be carefully evaluated prospectively.

Safety issue of re-sterilization of polyurethane electrophysiology catheters: a cytotoxicity study

The reuse of electrophysiology catheters could result in significant cost savings. However, re-sterilization of catheters could lead to several adverse consequences, including toxicity related to potential chemical reactions that occur during sterilization due to toxic residues remaining on the surface of catheters. The objective of this study was to investigate in vitro cytotoxicity of polyurethane (PU)-based catheter extracts on macrophages after their re-sterilization. We have compared three sterilization methods: steam autoclave, ethylene oxide (EtO) and hydrogen peroxide plasma (Sterrad system). Our results showed that the viability of cells varied from 90% to 99% as a function of incubation time and number of sterilization cycle. While there was no statistical difference based on the sterilization procedure, the number of sterilization cycles (up to 10 cycles) presents a statistically significant effect on the viability of J774 macrophages. However, extract obtained after resterilization of PU-based catheters had a low cytotoxic effect on J774 macrophages, since the overall cell mortality remained under 10%. An inhibitory effect on cell growth was also observed, which was not significant either as a function of incubation time, sterilization technique or the number of sterilization cycles. Finally, extracts of PU-based catheters had no statistically significant effect on TNF-alpha release by J774 macrophage. Even though there were some statistically significant differences between the control and processed samples, and among processed samples, our data suggest that one single reprocessing of PU-based catheters may not induce clinically significant changes in their cytotoxicity behaviour.

In vitro cytotoxicity testing of AB-polymer networks based on oligo(?-caprolactone) segments after different sterilization techniques

Recently developed versatile biodegradable polymeric biomaterial offer new therapeutic options in numerous medical fields. Biocompatibility is a crucial requirement for the biomedical application of biomaterials, including the sterilization of these materials with the use of accepted protocols. Ethylene-oxide (EO) and low-temperature plasma (LTP) sterilization are frequently used low-temperature sterilization technologies for heat-sensitive materials. The agarose diffusion assay is a recommended cell-screening test to assess the cytotoxicity of biomaterials in vitro. The sensitivity of the agarose assay can be increased by using a modified computer-based image-analysis system. The influence of EO and LTP sterilization on the cytotoxicity of a versatile polymer system of shape-memory polymer networks based on oligo (epsilon-caprolactone) dimethacrylate and n-butyl acrylate was investigated. Statistically significant differences in the rate of cell lysis after EO and LTP sterilization of the polymer samples were detected by using this modified quantification system. The influence of the different sterilization techniques on the cytotoxicity of the polymeric material, as well as the clinical relevance of the described differences, are discussed.

Change of the mechanical properties of two different balloon catheters with increasing numbers of cycles of resterilization

An increasing number of centers are reusing PTCA catheters even though manufacturers warrant single use only. This prospective bench laboratory trial addresses the quality of PTCA balloon catheters after up to three resterilization cycles in order to determine whether a larger trial is warranted to discern whether catheters should be reused. Forty PTCA catheters from two different manufacturers (nominal diameters 1.5 and 3.0 mm) were taken from the shelf. An independent institute tested mechanical properties such as burst pressure, nominal diameter, crossing profile, and balloon surface. The crossing profile increased by 22.5%-39.2% with no additional deterioration after repeated sterilizations. The nominal diameter either increased or decreased by a maximum of 47%. In all 1.5 mm balloons, the burst pressure remained above the manufacturers' values, whereas in the 3.0 mm balloons, the value dropped below the rated burst pressure in 40%-50% of the trials. In conclusion, in both catheter types analyzed, reuse was associated with a considerably worse quality, which puts in question their routine clinical use.

In vitro performance characteristics of reused ablation catheters

BACKGROUND

Prior studies have found that there is a widespread practice of catheter reprocessing in cardiac electrophysiology laboratories. Effects of reprocessing of ablation catheters on temperature sensing and mechanical deflection are not fully known.

METHODS

Twenty-four new and used ablation catheters were studied. Deviation of temperature sensing by catheters from the temperature of a heated saline bath was measured. The angle of deflection of digitally scanned catheters at 75% and 100% handle deflection was also measured. New and used catheters were compared with respect to their temperature sensing accuracy and deflection characteristics.

RESULTS

Overall, there was 0.7 +/- 0.1 degrees C (mean +/- standard error) deviation of the sensed temperature from the bath temperature, with no significant difference between new and used catheters. Similarly, there was no significant difference in the angle of deflection between new (66.7 degrees +/- 6.2 degrees and 24.3 degrees +/- 6.8 degrees at 75% and 100% deflections, respectively) and used (59.6 degrees +/- 5.6 degrees and 28.7 degrees +/- 9.9 degrees at 75% and 100% deflections, respectively) catheters. The difference in the angle of deflection between matched new and used catheters was 18.9 degrees +/- 4.2 degrees and 10.9 degrees +/- 2.4 degrees at 75% and 100% deflections, respectively, with a relatively broad range (5.0 degrees -35.6 degrees and 0.4 degrees -19.0 degrees at 75% and 100% deflections, respectively).

CONCLUSIONS

This study found no significant overall difference in temperature sensing accuracy and deflection angle of new and used ablation catheters. Nevertheless, individual differences in deflection characteristics between new and used catheters are occasionally seen and warrant screening of reprocessed catheters prior to their reuse.

Plasma-based sterilization: effect on surface and bulk properties and hydrolytic stability of reprocessed polyurethane electrophysiology catheters

Plasma-based sterilization is a promising alternative to ethylene oxide (EO) for reprocessing of electrophysiology catheters. To assess its safety in terms of material damage, modifications of surface and bulk properties as well as hydrolytic stability of sterilized catheters were evaluated. Polyurethane (PU) single-use electrophysiology catheters were subjected to one, five, and ten sterilization cycles by Sterrad-100S and Plazlyte, as well as by pure EO for comparison. Surface analysis techniques (ATR-FTIR, XPS, DCA) showed oxidation limited to the near-surface layer induced by both plasma-based sterilizers, whereas EO induced slight but deeper alkylation. Using bulk analysis techniques (RP-HPLC, SEC), oligomer alteration was observed after all three sterilization techniques, without modification of molecular weights. Hydrolytic stability of catheters was slightly changed by plasma-based sterilization, with a small increase in released oligomers. Finally, although Plazlyte and Sterrad are both plasma-based techniques, they induced different impacts on catheters, such as the degradation of an additive with Sterrad, and a clear difference in coloration with Plazlyte.

The safety of reusing ablation catheters with temperature control and the need for a validation protocol and guidelines for reprocessing

The objective of this study was to evaluate the safety of reusing ablation catheters with temperature control, which has not previously been reported. A review of previously conducted studies on the feasibility of reusing electrode catheters is also presented. From September 1994 to December 1997, 74 deflectable ablation catheters with temperature control (Cordis-Websters and Osypkas) were used during mean 7.6 +/- 8.0 ablation sessions. The catheter tests included visual inspection for surface defects using a magnification glass, impedance measurements, evaluation of the catheter deflection capability, and the integrity of the thermistor and thermocouple. The catheters were sterilized by Sterrad after each use. A total of 41 catheters were rejected after an average 9.1 +/- 8.8 uses (range 1-31). The main reasons for rejection were inaccurate temperature measurements by the thermistor or thermocouple (19%), breakage of or defect in the internal pulling wire (12%), loss or disturbance of electrogram (9%), and loss of deflection capability (8%). The reuse of the catheters has not resulted in any major catheter failures or any major adverse clinical complications. There were no local or systemic infections. It can be concluded that these types of ablation catheters will sustain repeated uses and resterilizations without untoward harm to the patient provided that a thorough validation protocol and guidelines for quality control and rejection of catheters are used. There seems to be no rational for setting a limit for the number of reuses, since most failures occurred at any time of reuse.