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Prevention of Percutaneous Driveline Infection After Left Ventricular Assist Device Implantation: Prophylactic Antibiotics Are Not Necessary

Stulak, John M.*; Maltais, Simon; Cowger, Jennifer; Joyce, Lyle D.*; Daly, Richard C.*; Park, Soon J.*; Aaronson, Keith D.; Pagani, Francis D.

doi: 10.1097/MAT.0b013e3182a9e2a5
Adult Circulatory Support

Infection is a major source of morbidity and mortality after ventricular assist device (VAD) implantation. The percutaneous driveline is the most common site of infection in these patients and often serves as a portal to deeper pump infections. There are no data defining the role of prophylactic antibiotics in preventing these infections. We compared all patients who underwent primary HeartMate II VAD implantation at two different institutions employing two different driveline infection prevention strategies between February 2007 and September 2011. While all patients received perioperative antibiotics, driveline maintenance strategies included sterile dressing changes with Hibiclens application without continued prophylactic antibiotics (Abx) (Mayo Clinic, n = 141, No Abx) and sterile dressing changes with continued prophylactic antibiotics (University of Michigan Hospital, n = 144, Abx). Although gender was similar between cohorts (Abx: 79% male vs. No Abx: 84% male, p = 0.25), median age at implant (Abx: 59 vs. No Abx: 64, p = 0.001) and destination therapy as indication for VAD (Abx: 22% vs. No Abx: 60%, p < 0.001) were significantly different. Follow-up was available in all late survivors (Abx: 140 patients, No Abx: 127 patients). Median duration of support was similar between groups (Abx: 12.3 months vs. No Abx: 11 months, p = 0.44). Total patient-years of device support were 172 years for 140 patients in the Abx cohort and 146 years for 127 patients in the No Abx cohort. Driveline drainage/infection was observed in 25 of 140 patients (18%) in the Abx group and 16 of 127 (13%) in the No Abx group (p = 0.15). Device exchange for major driveline infection was performed in seven patients in the Abx group and 0 patients in the No Abx group. Total driveline infection events per patient-years of support were 0.15 for the Abx group and 0.11 in the No Abx group (p = 0.43). There was no significant difference in the raw incidence of major driveline infections or driveline infections per patient-years of support in patients who were maintained on prophylactic antibiotics compared with those who were not. These data suggest that other factors may be more important than prophylactic antibiotics in preventing driveline infections.

From the *Mayo Clinic College of Medicine, Rochester, MN; Vanderbilt University Hospital, Nashville, TN; and University of Michigan Health System, Ann Arbor, MI.

Submitted for consideration May 2013; accepted for publication in revised form July 2013.

Disclosure: The authors have no conflicts of interest to report.

Reprint Requests: John M. Stulak, MD, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905. Email: stulak.john@mayo.edu.

Following from the demonstration that left ventricular assist devices (LVADs) are effective therapy for advanced heart failure,1 recent reports have documented a fivefold increase in LVAD implants from 2007 to 2011.2 Current LVADs require a percutaneous driveline for power supply, and this represents an interface between the device and the patient’s internal tissues with the contaminated, external environment. Infection of the percutaneous driveline remains the most common site of LVAD-related infection and, if progressive, this tract may predispose to deeper infection and lead to involvement of the device itself.3,4

Several reports have focused on identifying patient factors which increase risk of percutaneous driveline infections (DLIs), including younger age,5 obesity,6 diabetes,7 acuity of illness,8 and immunosuppression.4 In addition, others have identified procedural and postoperative factors that may contribute to DLI, including length of operation, blood product administration, and duration of postoperative length of stay.9,10 In contrast, very little data exist in the literature investigating whether long-term prophylactic antibiotic administration plays a role in preventing late DLI.

The aim of this study was to compare two different practices in the prevention of DLI (long-term prophylactic antibiotics versus no antibiotics) and analyze outcomes in terms of freedom from DLI and its impact on late survival.

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Methods

The data collection process and analysis was performed after informed patient consent and approved by the University of Michigan and Mayo Foundation Institutional Review Board. From February 2007 to September 2011, 285 patients (233 men) underwent primary ventricular assist device (VAD) implantation with a HeartMate II at University of Michigan Health System and Mayo Clinic College of Medicine (MC). Median age at operation was 60 years (range, 18–79 years). While all patients received perioperative antibiotic prophylaxis, differing strategies of long-term prevention of percutaneous driveline infection were employed. All patients were educated and trained to perform daily percutaneous driveline site care utilizing Hibiclens cleansing under sterile conditions; this was the sole infection prevention strategy at Mayo Clinic (n = 141) (No Abx cohort), whereas practice at University of Michigan added daily administration of oral Doxycycline and Levofloxacin (n = 144) (Abx cohort).

Preoperative clinical characteristics are presented in Table 1; there were significant differences between the No Abx and Abx cohort, including age (64 vs. 59, respectively, p = 0.001), destination therapy (60% vs. 22%, p < 0.001), and preoperative intraballoon pump therapy (40% vs. 63%, p < 0.001). Preoperative laboratory values are presented in Table 2; there were significant differences between the No Abx and Abx cohort, including white blood cell count (9.0 vs. 7.7, respectively, p < 0.001), platelet count (170 vs. 189, p = 0.04), and creatinine (1.6 vs. 1.3, p < 0.001).

Table 1

Table 1

Table 2

Table 2

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Statistical Analysis

Demographic and other patient-related data were obtained from the University of Michigan and Mayo Clinic medical record and our prospectively collected clinical database. Follow-up information was obtained from subsequent clinic visits, and written correspondence from local physicians. Data were expressed either as mean ± standard error of the mean for normally distributed data or median with range for non-normally distributed data. Data between two groups were compared using Student’s paired t-test or Chi-square for continuous and dichotomous variables, respectively. Actuarial survival was determined using Kaplan–Meier analysis and compared by log rank. Statistical significance was considered at p < 0.05. Early operative mortality was defined as death occurring within 30 days of operation or at any time during the index hospitalization.

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Results

All patients underwent HeartMate II implantation through a midline sternotomy, and all patients received perioperative prophylactic antibiotics; the regimen was at the discretion of the implanting surgeon. Intraoperative findings and data are presented in Table 3; there were significant differences between the No Abx and Abx cohorts, including redo sternotomy (48% vs. 32%, respectively, p = 0.004), cardiopulmonary bypass time (102 vs. 75 minutes, p < 0.001), and concomitant valve procedure (54% vs. 35%, p < 0.001). There were 14 (10%) early deaths in the No Abx group and 4 (3%) in the Abx group (p = 0.01). Significant early nonfatal morbidity in the No Abx and Abx cohort, respectively, included right ventricular failure in 28 (20%) and 14 (10%) patients (p = 0.01), renal failure requiring dialysis in 15 (11%) and 12 (8%), and stroke in 16 (11%) and 14 (10%) (p = 0.34).

Table 3

Table 3

There were 127 and 140 early survivors in the No Abx and Abx cohorts, respectively, and late follow-up was available in 100%. Median length of support at last follow-up was 11 months in the No Abx cohort and 12.3 months in the Abx cohort (p = 0.26). Total patient-years of support in the early survivors was 146 in the No Abx cohort and 172 in the Abx cohort (p = 0.26). The raw incidence of late percutaneous DLI was 13% in the No Abx cohort and 18% in the Abx cohort (p = 0.15); events per year of support were 0.11 and 0.15, respectively (p = 0.43). Hospital readmissions for evaluation of and treatment for percutaneous DLI were six in the No Abx group and 19 in the Abx group (p < 0.001). Device exchange was performed to treat major percutaneous DLI in 0 patients in the No Abx group compared with seven (5%) in the Abx group (p = 0.01).

Freedom from late percutaneous DLI for the entire cohort was 90% at 1 year, 83% at 2 years, and 73% at 3 years (Figure 1A). There was no statistically significant difference between cohorts (p = 0.80) (Figure 1B). Overall survival for the entire cohort was 86% at 1 year, 72% at 2 years, and 65% at 3 years (Figure 2A). There was no statistically significant difference in survival between study groups (p = 0.15) (Figure 2B).

Figure

Figure

Figure

Figure

Two-thirds of all late percutaneous DLI occurred in patients who had the pump implanted as destination therapy, and on multivariate analysis, duration of support was independently associated with increased risk of developing late percutaneous DLI; this risk rose 4% for each month on support. When analyzed as a time-dependent covariate, development of a late percutaneous DLI did not significantly affect late survival in either the No Abx group (HR: 0.164, [0.022, 1.21], p = 0.076) or the Abx group (HR: 0.21, [0.03, 1.6], p = 0.131).

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Comment

This study demonstrates that raw incidence of and time-related freedom from late percutaneous DLI was similar in patients who received chronic prophylactic antibiotics after VAD implantation compared with those who did not receive chronic prophylactic antibiotics. Similar to a new report,11 we found that length of support after VAD implant was most predictive of development of late percutaneous DLI, and not surprisingly, the majority of percutaneous DLI occurred in destination therapy patients. In contrast to other studies,5 we did not observe a negative impact on survival in patients who developed a late percutaneous DLI.

Although this is the first study to specifically compare patients receiving antibiotics for DLI prevention with those who did not, it outlines that the likelihood that other factors play a more influential role for the development of DLI. For instance, trauma has consistently been identified as an important causative factor for the development of DLI.12,13 An adherent interface between the velour of the driveline and the patient’s tissues is critical for the protection against entry of microorganisms and subsequent infection. As patients become increasingly mobile after LVAD implantation, shearing and torsion of this site can disrupt this intact surface and continued sliding of the driveline prevents future readherence. This promotes a new tract adjacent to the driveline, which can then hypothetically serve as a portal for deeper infection.4 All patients in this series were educated not only in sterile driveline site care but also of the importance of driveline immobilization. Although not uniform between the two institutions participating in this study or all the operating surgeons, the following are some maneuvers we employ to prevent mechanical stress on the driveline exit site. Early postoperatively, an anchoring stitch is placed on the skin and the driveline is secured to this area approximately 6 inches from the exit site. This point of fixation serves to protect against tugging in the early postoperative period as tension will be exerted at this point and not the exit site while it is healing and becoming incorporated. In addition, a pursestring suture is also fashioned in the subdermal layer immediately at the exit site to encourage sealing of the skin to the driveline itself. In addition, we avoid allowing this site to become wet until well after it has become healed and the skin incorporated onto the driveline. We believe that these maneuvers are likely far more critical than antibiotic prophylaxis in the prevention of late percutaneous DLI. Certainly, patient compliance with daily site care and “buy-in” to the importance of avoidance of trauma will play a crucial role in reducing the incidence of these events in the future.

When a patient has a suspected percutaneous DLI, we favor readmission to the hospital and instituting intravenous antibiotic therapy as soon as possible. We obtain blood cultures as well as a driveline site swab for culture. Consistent with others,4,7 staphylococci were present in the majority of cultures we obtain from driveline swab site swab. It is well documented that organisms found in the bloodstream can match those found at the driveline exit site and vice versa.14–16 Computerized tomography can be obtained to evaluate for deeper fluid collections; however, in our experience, interference from the device makes definitive evaluation challenging. Ultrasonography can also be used to evaluate the patient for abscesses or deeper fluid collections.

Progression of a superficial percutaneous DLI to a deeper pump pocket infection is a significant concern and may result in the need for device exchange or urgent transplantation.17–19 Furthermore, device exchange or transplantation for significant driveline infection is much less morbid than for a pump pocket infection. Device exchange for infection can be performed with low morbidity and low rate in reinfection if performed before development of a frank pump pocket infection.19 As a result, one institution (University of Michigan Health System) in this study is aggressive at device exchange, whereas the other (MC) has been successful in local treatment of these infections, including vacuum-assisted therapy20,21 and even local surgical debridement.22 Although the approaches to treatment of percutaneous DLI differed between institutions, the prevention strategies employed before developing the infection was the focus of this study.

Although percutaneous DLI is recognized as the “Achilles’ Heel” of LVAD therapy, prevention is the best intervention for addressing this complication rather than treating the complication itself once it develops. In our practice, thorough patient education includes respecting the importance of driveline immobilization, daily driveline site care, and early recognition of possible percutaneous DLI. Routine follow-up evaluation after LVAD implantation with inspection of the driveline exit site is also critical. If an infection develops, the aforementioned interventions are employed for early diagnosis and treatment. A multidisciplinary approach with involvement of surgeons, nursing staff, VAD coordinators, cardiologists, and infectious disease specialists optimizes effective management of these patients.

As mentioned earlier, this was a comparison of two different institutions and thus reflects two different practices. This was responsible for some of the disparate findings between cohorts and between outcomes. The majority of patients at University of Michigan Health System were implanted as bridge to transplant, whereas most at MC were destination therapy, and this also reflects why the cohort from MC was older. Other preoperative clinical characteristics were generally equivalent. There were more redo sternotomies, concomitant valve procedures, and longer operative times at MC, and despite these differences, late DLI was still similar compared with the University of Michigan Health System cohort. This emphasizes the point that while these factors have been identified as risk factors for increased risk of percutaneous DLI, the most important factor is likely maintenance of the site and avoidance of trauma. Chronic prophylactic antibiotics did not seem to play a significant role in preventing percutaneous DLI in this study.

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Limitations

This study has several important limitations that need acknowledged. Although this data was prospectively collected, it was retrospectively analyzed. In comparing the practices of two different institutions, differences in patient populations were also encountered. These differences existed in preoperative characteristics, operative data, and early postoperative outcomes. Despite this, interestingly, outcomes of primary interest, specifically percutaneous DLI was similar between the groups. We were not able to confirm a history of trauma as a cause of DLI in the majority of patients. Also, importantly, while all patients received perioperative prophylactic antibiotics, there was a wide variation in practices in this regard as to the types of antibiotics and duration postoperatively.

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Summary

In summary, we demonstrate similar incidence of percutaneous DLI in patients receiving chronic antibiotic prophylaxis in addition to daily site care compared with those who only performed daily site care without antibiotics. The development of DLI did not negatively impact late survival in these patients. Duration of support was identified as the highest risk factor for development of percutaneous DLI after LVAD implant.

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References

1. Rose EA, Gelijns AC, Moskowitz AJ, et al.Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure (REMATCH) Study Group. Long-term use of a left ventricular assist device for end-stage heart failure. N Engl J Med. 2001;345:1435–1443
2. Kirklin JK, Naftel DC, Kormos RL, et al. The Fourth INTERMACS Annual Report: 4,000 implants and counting. J Heart Lung Transplant. 2012;31:117–126
3. Sun BC, Catanese KA, Spanier TB, et al. 100 long-term implantable left ventricular assist devices: The Columbia Presbyterian interim experience. Ann Thorac Surg. 1999;68:688–694
4. Gordon RJ, Quagliarello B, Lowy FD. Ventricular assist device-related infections. Lancet Infect Dis. 2006;6:426–437
5. Goldstein DJ, Naftel D, Holman W, et al. Continuous-flow devices and percutaneous site infections: Clinical outcomes. J Heart Lung Transplant. 2012;31:1151–1157
6. Raymond AL, Kfoury AG, Bishop CJ, et al. Obesity and left ventricular assist device driveline exit site infection. ASAIO J. 2010;56:57–60
7. Simon D, Fischer S, Grossman A, et al. Left ventricular assist device-related infection: Treatment and outcome. Clin Infect Dis. 2005;40:1108–1115
8. Pereda D, Conte JV. Left ventricular assist device driveline infections. Cardiol Clin. 2011;29:515–527
9. Schaffer JM, Allen JG, Weiss ES, et al. Infectious complications after pulsatile-flow and continuous-flow left ventricular assist device implantation. J Heart Lung Transplant. 2011;30:164–174
10. Topkara VK, Kondareddy S, Malik F, et al. Infectious complications in patients with left ventricular assist device: Etiology and outcomes in the continuous-flow era. Ann Thorac Surg. 2010;90:1270–1277
11. Sharma V, Deo SV, Stulak JM, et al. Driveline infections in left ventricular assist devices: Implications for destination therapy. Ann Thorac Surg. 2012;94:1381–1386
12. Zierer A, Melby SJ, Voeller RK, et al. Late-onset driveline infections: The Achilles’ heel of prolonged left ventricle assist device support. Ann Thorac Surg. 2007;90:1270–1277
13. Jarvik R, Westaby S, Katsumata T, Pigott D, Evans RD. LVAD power delivery: A percutaneous approach to avoid infection. Ann Thorac Surg. 1998;65:470–473
14. Sivaratnam K, Duggan JM. Left ventricular assist device infections: Three case reports and a review of the literature. ASAIO J. 2002;48:2–7
15. Vilchez RA, McEllistrem MC, Harrison LH, McCurry KR, Kormos RL, Kusne S. Relapsing bacteremia in patients with ventricular assist device: An emergent complication of extended circulatory support. Ann Thorac Surg. 2001;72:96–101
16. Herrmann M, Weyand M, Greshake B, et al. Left ventricular assist device infection is associated with increased mortality but is not a contraindication to transplantation. Circulation. 1997;95:814–817
17. Argenziano M, Catanese KA, Moazami N, et al. The influence of infection on survival and successful transplantation in patients with left ventricular assist devices. J Heart Lung Transplant. 1997;16:822–831
18. Prendergast TW, Todd BA, Beyer AJ 3rd, et al. Management of left ventricular assist device infection with heart transplantation. Ann Thorac Surg. 1997;64:142–147
19. Stulak JM, Cowger J, Haft JW, Romano MA, Aaronson KD, Pagani FD. Device exchange after primary left ventricular assist device implantation: Indications and outcomes. Ann Thorac Surg. 2013;95:1262–1267; discussion 1267
20. Baradarian S, Stahovich M, Krause S, Adamson R, Dembitsky W. Case series: Clinical management of persistent mechanical assist device driveline drainage using vacuum-assisted closure therapy. ASAIO J. 2006;52:354–356
21. Yuh DD, Albaugh M, Ullrich S, Conte JV. Treatment of ventricular assist device driveline infection with vacuum-assisted closure system. Ann Thorac Surg. 2005;80:1493–1495
22. Argenta LC, Morykwas MJ. Vacuum-assisted closure: A new method for wound control and treatment: Clinical experience. Ann Plast Surg. 1997;38:563–576; discussion 577
Keywords:

infection; driveline; mechanical circulatory support

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