Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Late outcomes of subcostal exchange of the HeartMate II left ventricular assist device: a word of caution

Late outcomes of subcostal exchange of the HeartMate II left ventricular assist device: a word of... Abstract OBJECTIVES Previous studies have shown the usefulness of the subcostal exchange of the HeartMate II left ventricular assist device for device malfunction. However, long-term data are still limited. METHODS Between March 2004 and July 2017, 41 of 568 (7.2%) patients who had received a HeartMate II implant at our institution had a device exchange via a subcostal incision. We summarized early and late outcomes. RESULTS Forty-one patients had a total of 48 subcostal pump exchanges. Indications for device exchange included device thrombosis (n = 31, 76%), driveline infection (n = 2, 5%) and driveline injury (n = 8, 19%). All of the procedures were successful, and there were no in-hospital deaths. A Kaplan–Meier survival curve showed 30-day and 1-year survival rates after subcostal exchange of 100% and 94.6%, respectively. However, 10 (25%) patients had left ventricular assist device-related infections following subcostal exchange that included 7 pump pocket infections and 3 driveline infections. Freedom from left ventricular assist device-related infection at 1 year after subcostal exchange was 79.3%. Thirteen (32%) patients had device malfunction due to pump thrombosis that required a 2nd device exchange. Seven patients had recurrent thrombosis. Three (7%) patients had a stroke. Freedom from device thrombosis and from a stroke event at 1 year was 74.4%. CONCLUSIONS Subcostal pump exchange can be safely performed. However, there is a substantial risk of infection and recurrent thrombosis. Careful follow-up for late complications is mandatory. Ventricular assist device , Subcostal exchange , Device thrombosis , Device infection INTRODUCTION Device malfunction including device thrombosis is a not uncommon and potentially fatal complication during continuous-flow left ventricular assist device (LVAD) support. Since the initial reports of the abrupt increase in the incidence of device thrombosis with the HeartMate II (HM II, Abbott, Abbott Park, IL, USA) [1, 2], a yearly thrombosis rate of about 10% has been noted by the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) reports [3]. The most recent report showed a higher incidence of device malfunctions involving the controller, battery and cable in addition to failure of the pump itself [4]. Once device malfunction is confirmed, early device exchange rather than watchful waiting is recommended to minimize the risk of adverse events [5]. The subcostal approach has been reported to be the preferred method for device exchange for patients who do not have inflow and outflow issues, because it is a less invasive procedure associated with shorter intensive care unit times and fewer postoperative complications than resternotomy [6–8]. However, data on the long-term clinical outcomes of this procedure are limited. In this study, our aim was to assess for late outcomes of patients who had subcostal HM II exchange. MATERIALS AND METHODS Patient selection This study was approved by the institutional review board of the Columbia University Medical Center. Between March 2004 and July 2017, 60 of 568 (10.6%) patients who had received a HM II implant at Columbia University Medical Center received a device exchange. Among them, the 41 (7.2%) patients who underwent subcostal exchange comprise our cohort of interest. Indication and surgical technique for subcostal exchange Once device malfunction is suspected, analysis of the log file is routinely performed. Radiographs are taken to detect driveline injury. Computed tomography angiography is used preoperatively to assess for kinking, malposition and thrombus in the inflow and outflow cannulas [9, 10]. For patients who have suspected device thrombosis, we routinely perform an echocardiographic ramp study [11] in addition to measuring serial serum lactate dehydrogenase and plasma-free haemoglobin levels. Our treatment algorithm for device thrombosis was reported previously [5]. Since June 2011, we have elected to perform a subcostal incision over a resternotomy for device exchange, unless there is a need to access the outflow or inflow cannulas (due to thrombus, infection or kinking of the graft) or to perform a concomitant cardiac procedure requiring sternotomy. Our surgical technique for subcostal HM II exchange was reported previously [6]. Briefly, a reverse J-shaped incision is made from the xiphoid process to the left mid-clavicular line to expose the pump from the bend relief site to the inflow arm. Cardiopulmonary bypass is initiated via femoral vessel cannulation. Most recently, a more limited incision (2 separate incisions) has been applied in order to minimize delayed wound healing (Fig. 1). Figure 1: View largeDownload slide A limited incision consisting of 2 separate incisions is now applied in order to minimize wound healing delay after subcostal exchange. Figure 1: View largeDownload slide A limited incision consisting of 2 separate incisions is now applied in order to minimize wound healing delay after subcostal exchange. Data collection and follow-up Medical records were reviewed for collection of baseline characteristics, postoperative complications and outcomes. Median support duration from initial subcostal exchange to time of analysis was 1876 days (1309–2292). Follow-up information was available and collected until 31 July 2017 for all patients. Postoperative complications included right ventricular failure, acute kidney injury, ventricular arrhythmia, gastrointestinal bleeding, LVAD-related infection, stroke and device thrombosis according to INTERMACS definitions. Driveline and pump pocket infections were confirmed by wound culture and radiological observation of fluid collections [12]. Stroke was confirmed by a brain imaging study. Duration to heart transplant was calculated as time from initial subcostal exchange. Statistical analysis Continuous variables are reported as mean ± standard deviation. The 95% confidence intervals (CIs) are additionally represented. Kaplan–Meier analysis was used to calculate survival rates and freedom from device complications with plots truncated after 3 years due to limited observations at later time points. Statistical significance was defined as a 2-sided α ≤ 0.05. Statistical analysis was performed using Stata 14 software (Stata Corp, College Station, TX, USA). RESULTS Patient baseline characteristics Baseline characteristics are summarized in Table 1. The mean age was 54.6 ± 13.5 years; 80% were men; 32% had ischaemic and 61% had dilated aetiologies; 63% were designated for bridge to transplant. Table 1: Baseline characteristics at the time of the primary subcostal device exchange n = 41 Age (years) 54.6 ± 13.5 Male (%) 33 (80) BMI (kg/m2) 27.3 ± 5.4 BSA (m2) 2.0 ± 0.2 Intention to treat  BTT 26 (63)  DT 15 (37) Aetiology of cardiomyopathy  Dilated 25 (61)  Ischaemic 13 (32)  Other 3 (7) Hypertension 21 (51) Diabetes mellitus 12 (29) Hyperlipidaemia 15 (37) Indication for exchange  Device thrombosis 31 (76)  Driveline infection 2 (5)  Driveline injury 8 (19) Incisional approach  Extended J-shaped incision 35 (85)  Modified 2-incision approach 6 (15) Support duration to subcostal exchange (days) 462 (178–778) Preoperative laboratory values  WBC (×1000/ml) 7.3 ± 2.0  Haemoglobin (g/dl) 10.6 ± 2.0  Haematocrit (%) 32.5 ± 5.5  Platelets (×1000/ml) 178.2 ± 68.0  LDH (U/l) 1080 (420–1753)  INR 1.6 (1.2–1.9)  BUN (mg/dl) 22.0 (15.0–31.0)  Creatinine (mg/dl) 1.3 (1.0–1.6) Pump parameters  Pump flow (l/min) 5.3 ± 0.9  Pump speed (rpm) 9150 ± 500  Pulsatility index 4.9 ± 1.8  Power (W) 5.8 ± 1.5 CPB time (min) 22 (12–27) Length of ICU stay (days) 5 (4–8) n = 41 Age (years) 54.6 ± 13.5 Male (%) 33 (80) BMI (kg/m2) 27.3 ± 5.4 BSA (m2) 2.0 ± 0.2 Intention to treat  BTT 26 (63)  DT 15 (37) Aetiology of cardiomyopathy  Dilated 25 (61)  Ischaemic 13 (32)  Other 3 (7) Hypertension 21 (51) Diabetes mellitus 12 (29) Hyperlipidaemia 15 (37) Indication for exchange  Device thrombosis 31 (76)  Driveline infection 2 (5)  Driveline injury 8 (19) Incisional approach  Extended J-shaped incision 35 (85)  Modified 2-incision approach 6 (15) Support duration to subcostal exchange (days) 462 (178–778) Preoperative laboratory values  WBC (×1000/ml) 7.3 ± 2.0  Haemoglobin (g/dl) 10.6 ± 2.0  Haematocrit (%) 32.5 ± 5.5  Platelets (×1000/ml) 178.2 ± 68.0  LDH (U/l) 1080 (420–1753)  INR 1.6 (1.2–1.9)  BUN (mg/dl) 22.0 (15.0–31.0)  Creatinine (mg/dl) 1.3 (1.0–1.6) Pump parameters  Pump flow (l/min) 5.3 ± 0.9  Pump speed (rpm) 9150 ± 500  Pulsatility index 4.9 ± 1.8  Power (W) 5.8 ± 1.5 CPB time (min) 22 (12–27) Length of ICU stay (days) 5 (4–8) Values are represented as mean ± SD, median (Q1–Q3) or n (%). BMI: body mass index; BSA: body surface area; BTT: bridge to transplant; BUN: blood urea nitrogen; CPB: cardiopulmonary bypass; DT: destination therapy; ICU: intensive care unit; INR: international normalized ratio; LDH: lactate dehydrogenase; WBC: white blood cells. Table 1: Baseline characteristics at the time of the primary subcostal device exchange n = 41 Age (years) 54.6 ± 13.5 Male (%) 33 (80) BMI (kg/m2) 27.3 ± 5.4 BSA (m2) 2.0 ± 0.2 Intention to treat  BTT 26 (63)  DT 15 (37) Aetiology of cardiomyopathy  Dilated 25 (61)  Ischaemic 13 (32)  Other 3 (7) Hypertension 21 (51) Diabetes mellitus 12 (29) Hyperlipidaemia 15 (37) Indication for exchange  Device thrombosis 31 (76)  Driveline infection 2 (5)  Driveline injury 8 (19) Incisional approach  Extended J-shaped incision 35 (85)  Modified 2-incision approach 6 (15) Support duration to subcostal exchange (days) 462 (178–778) Preoperative laboratory values  WBC (×1000/ml) 7.3 ± 2.0  Haemoglobin (g/dl) 10.6 ± 2.0  Haematocrit (%) 32.5 ± 5.5  Platelets (×1000/ml) 178.2 ± 68.0  LDH (U/l) 1080 (420–1753)  INR 1.6 (1.2–1.9)  BUN (mg/dl) 22.0 (15.0–31.0)  Creatinine (mg/dl) 1.3 (1.0–1.6) Pump parameters  Pump flow (l/min) 5.3 ± 0.9  Pump speed (rpm) 9150 ± 500  Pulsatility index 4.9 ± 1.8  Power (W) 5.8 ± 1.5 CPB time (min) 22 (12–27) Length of ICU stay (days) 5 (4–8) n = 41 Age (years) 54.6 ± 13.5 Male (%) 33 (80) BMI (kg/m2) 27.3 ± 5.4 BSA (m2) 2.0 ± 0.2 Intention to treat  BTT 26 (63)  DT 15 (37) Aetiology of cardiomyopathy  Dilated 25 (61)  Ischaemic 13 (32)  Other 3 (7) Hypertension 21 (51) Diabetes mellitus 12 (29) Hyperlipidaemia 15 (37) Indication for exchange  Device thrombosis 31 (76)  Driveline infection 2 (5)  Driveline injury 8 (19) Incisional approach  Extended J-shaped incision 35 (85)  Modified 2-incision approach 6 (15) Support duration to subcostal exchange (days) 462 (178–778) Preoperative laboratory values  WBC (×1000/ml) 7.3 ± 2.0  Haemoglobin (g/dl) 10.6 ± 2.0  Haematocrit (%) 32.5 ± 5.5  Platelets (×1000/ml) 178.2 ± 68.0  LDH (U/l) 1080 (420–1753)  INR 1.6 (1.2–1.9)  BUN (mg/dl) 22.0 (15.0–31.0)  Creatinine (mg/dl) 1.3 (1.0–1.6) Pump parameters  Pump flow (l/min) 5.3 ± 0.9  Pump speed (rpm) 9150 ± 500  Pulsatility index 4.9 ± 1.8  Power (W) 5.8 ± 1.5 CPB time (min) 22 (12–27) Length of ICU stay (days) 5 (4–8) Values are represented as mean ± SD, median (Q1–Q3) or n (%). BMI: body mass index; BSA: body surface area; BTT: bridge to transplant; BUN: blood urea nitrogen; CPB: cardiopulmonary bypass; DT: destination therapy; ICU: intensive care unit; INR: international normalized ratio; LDH: lactate dehydrogenase; WBC: white blood cells. Indications for subcostal exchange included device thrombosis (n = 31, 76%), driveline infection (n = 2, 5%) and driveline injury (n = 8, 19%). The extended J incision was used in 35 (85%) patients, whereas 6 underwent a modified 2-incision approach. Median duration on LVAD support until subcostal exchange was 462 (178–778) days. Early outcomes There were no in-hospital deaths after subcostal exchange. Early postoperative complications included right ventricular failure (n = 2), acute kidney injury (n = 4), ventricular tachycardia (n = 5), gastrointestinal bleeding (n = 2) and amiodarone-induced thyrotoxicosis (n = 1). Follow-up complications Freedom from LVAD-related infection 30 days and 1 year after subcostal exchange was 95.1% and 79.3%, respectively (Fig. 2A). Ten (25%) patients had pump pocket or driveline infection following subcostal exchange (Table 2). Two patients had early pump pocket infection during the indexed hospitalization and underwent surgical incision and drainage. The remaining 8 LVAD-related infections occurred a mean of 462 (95% CI 22–903) days after subcostal exchange, with 3 patients who developed infection after 1 year. Four required incision and drainage with vacuum-assisted closure therapy, all of whom had chronic infection and required later surgical debridement. One patient had an LVAD explant and subsequent reinsertion 2 weeks after the infection resolved. The other 3 patients who had isolated driveline infection were managed with long-term antibiotic therapy and did not have recurrent infection. Staphylococcus genus and Pseudomonas aeruginosa were the most commonly detected pathogens on wound culture (Table 2). Table 2: Left ventricular assist device-related infection after subcostal exchange n = 10 LVAD-related infection  Driveline infection 3  Pump pocket infection 7 Pathogens  Staphylococcus   Methicillin-sensitive 1   Methicillin-resistant 1   Staphylococcus lugdunensis 1  Pseudomonas aeruginosa 3  Serratia marcescens 2  Enterococcus faecalis (formerly Enterobacter faecalis) 1  Culture negative 1 n = 10 LVAD-related infection  Driveline infection 3  Pump pocket infection 7 Pathogens  Staphylococcus   Methicillin-sensitive 1   Methicillin-resistant 1   Staphylococcus lugdunensis 1  Pseudomonas aeruginosa 3  Serratia marcescens 2  Enterococcus faecalis (formerly Enterobacter faecalis) 1  Culture negative 1 LVAD: left ventricular assist device. Table 2: Left ventricular assist device-related infection after subcostal exchange n = 10 LVAD-related infection  Driveline infection 3  Pump pocket infection 7 Pathogens  Staphylococcus   Methicillin-sensitive 1   Methicillin-resistant 1   Staphylococcus lugdunensis 1  Pseudomonas aeruginosa 3  Serratia marcescens 2  Enterococcus faecalis (formerly Enterobacter faecalis) 1  Culture negative 1 n = 10 LVAD-related infection  Driveline infection 3  Pump pocket infection 7 Pathogens  Staphylococcus   Methicillin-sensitive 1   Methicillin-resistant 1   Staphylococcus lugdunensis 1  Pseudomonas aeruginosa 3  Serratia marcescens 2  Enterococcus faecalis (formerly Enterobacter faecalis) 1  Culture negative 1 LVAD: left ventricular assist device. Figure 2: View largeDownload slide Freedom from adverse events: (A) left ventricular assist device-related infection; (B) device thrombosis and stroke. CI: confidence interval. Figure 2: View largeDownload slide Freedom from adverse events: (A) left ventricular assist device-related infection; (B) device thrombosis and stroke. CI: confidence interval. Freedom from device thrombosis and a stroke event 30 days and 1 year after subcostal exchange was 100% and 74.4%, respectively (Fig. 2B). Three (7%) patients suffered a stroke at 17, 28 and 86 days after the exchange. Thirteen (32%) patients had recurrent device malfunction requiring surgical interventions at a mean of 454 (95% CI 118–789) days after the initial subcostal exchange. Twelve had device thrombosis, 7 of whom had recurrent thrombosis (the indication for the initial and 2nd device exchanges was device thrombosis). These patients required a 2nd device exchange via a subcostal exchange (n = 6), a device exchange via resternotomy (n = 4) or a heart transplant (n = 2). One patient had driveline injury after the exchange and required a resubcostal exchange. Freedom from recurrent device malfunction at 1 year was 88%. Late outcomes Of 41 patients, 21 (51%) had a heart transplant a mean of 268 (95% CI 175–361) days after the initial subcostal exchange. The Kaplan–Meier survival curve showed 30-day and 1-year survival rates after subcostal exchange of 100% and 94.6%, respectively (Fig. 3). Figure 3: View largeDownload slide Survival after subcostal exchange. CI: confidence interval. Figure 3: View largeDownload slide Survival after subcostal exchange. CI: confidence interval. DISCUSSION We examined early and late outcomes after subcostal device exchange for HM II device malfunction. Many studies have reported the subcostal technique to be a procedure with a low early mortality rate [13, 14]. Likewise, there were no in-hospital deaths with the subcostal exchange in our study, further supporting the safeness of this surgical technique when device exchange is warranted. However, LVAD-related infections and recurrent device malfunction are major causes of morbidity during the late follow-up period. With the rising frequency and duration of support on LVAD therapy, preventive measures and appropriate management of these device complications are necessary. Device-related infection is one of the most common causes for readmission for patients on LVAD support, with a reported incidence in up to 59% of patients [15–20]. Driveline infection is the most common LVAD-related infection [17] because it is often the site of entry for pathogens. Staphylococci are the most common pathogens reported, followed by pseudomonads [17, 21, 22]. If it is not properly treated, infection of the driveline can subsequently invade the pump pocket and cause systemic bloodstream complications, which can result in death. Although device-related infections are well-described in the literature, our study is the first to assess the incidence of infection as a consequence of device exchange. In our cohort, 25% of patients had an LVAD-related infection after subcostal exchange. Notably, 70% of these patients suffered from pump pocket infection that was not related to driveline infection, including 2 patients who had early pocket infection. Furthermore, it is important to note that the majority of device-related infections occurred after the patients were discharged following subcostal exchange. Prior studies have mentioned that most LVAD infections occur out of the hospital as a result of trauma at the driveline site [21, 22]. This result speaks to the fact that, whereas device exchange is an invasive procedure that can increase the susceptibility of patients to infection, the high rate of infection is inevitable largely due to the percutaneous nature of the HM II devices. Techniques to stabilize the driveline and minimize trauma are currently in development [23, 24]. Moreover, we thought that some of the late pocket infections were related to delayed wound healing resulting from the extended J incision with transection of the rectus muscles, fascia and ribs. These patients returned with probable pump pocket contamination from the incision. Based on our observations, we now perform a more limited 2-incision approach, as was done for 6 patients in this study, to minimize the opportunity and entry site for infection. Since we implemented this technique, we have not seen any type of pump pocket infection. The best treatment for LVAD-associated infections is device explant and/or heart transplant [25], but this option is often not available. Overall, patients in our study with driveline and pump pocket infections were managed successfully with antibiotic therapy and surgical debridement with or without vacuum-assisted closure. Device thrombosis is another detrimental complication of LVAD therapy that has become of particular concern in recent years. Since 2011, the incidence of HM II device thrombosis has increased [1, 2]. Adherence to a standardized practice for clinical management was shown to reduce the risk of early device thrombosis in the PREVENT clinical trial [26]; however, many thromboembolic events also occur as late complications in patients on LVAD support. Once device thrombosis occurs, early device exchange should be considered rather than a watch and wait approach [5]. Although subcostal exchange is our preferred technique for device exchange, this approach carries the risk of missing a thrombus outside the pump. Furthermore, when pump thrombosis is precipitated by anatomical abnormalities of the device (such as inflow malpositioning or outflow kinking), a resternotomy can help to correct the anomaly and minimize the risk of recurrence. We previously reported a high rate of recurrent thrombosis (31%) in patients who had a prior device exchange (subcostal or sternotomy) for thrombosis [27]. Similarly, in this study, 7 of 29 (24%) patients had a recurrent thrombotic event and underwent 2nd device exchange or explant. Recent studies suggest that device positioning, particularly inflow graft angulation and pump pocket depth, influence the risk of device thrombosis; hence a careful surgical technique should be used to ensure proper positioning of the LVAD at time of implant [28]. Moreover, there is an association between these 2 major complications of device exchange. Heightened inflammation as a result of infection can predispose a patient to a procoagulant status and increase the risk of having a thromboembolic event [29, 30]. Among the 12 patients who had device thrombosis requiring recurrent device exchange, 3 (25%) had a device-related infection within 2 months prior to the thrombotic event. Limitations Our study has several limitations. First, it is a single-centre retrospective study. Second, there are currently no standard criteria for infection in patients on LVAD support; hence the criteria for infection remains largely variable among studies. A consistent definition is needed in order to develop a better method for prevention and management of LVAD-associated infections. Furthermore, although we have focused only on device-specific complications, several other factors including gastrointestinal bleeding and systemic infection are large contributors to the morbidity and mortality of patients on LVAD support. CONCLUSION In conclusion, subcostal exchange is a safe procedure that can be performed with no in-hospital deaths and good long-term outcomes. However, a high prevalence of device-associated infections and thromboembolism persist following device exchange. Careful management of these complications is mandatory. Conflict of interest: Yoshifumi Naka has received consulting fees from Abbott Inc. The remaining authors have no conflicts of interest to disclose. REFERENCES 1 Starling RC , Moazami N , Silvestry SC , Ewald G , Rogers JG , Milano CA et al. Unexpected abrupt increase in left ventricular assist device thrombosis . N Engl J Med 2014 ; 370 : 33 – 40 . Google Scholar CrossRef Search ADS PubMed 2 Kirklin JK , Naftel DC , Kormos RL , Pagani FD , Myers SL , Stevenson LW et al. Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) analysis of pump thrombosis in the HeartMate II left ventricular assist device . J Hear Lung Transplant 2014 ; 33 : 12 – 22 . Google Scholar CrossRef Search ADS 3 Kirklin JK , Naftel DC , Pagani FD , Kormos RL , Stevenson LW , Blume ED et al. Seventh INTERMACS annual report: 15,000 patients and counting . J Hear Lung Transplant 2015 ; 34 : 1495 – 504 . Google Scholar CrossRef Search ADS 4 Kormos RL , McCall M , Althouse A , Lagazzi L , Schaub R , Kormos MA et al. Left ventricular assist device malfunctions: it is more than just the pump . Circulation 2017 ; 136 : 1714 – 25 . Google Scholar CrossRef Search ADS PubMed 5 Levin AP , Saeed O , Willey JZ , Levin CJ , Fried JA , Patel SR et al. Watchful waiting in continuous-flow left ventricular assist device patients with ongoing hemolysis is associated with an increased risk for cerebrovascular accident or death . Circ Heart Fail 2016 ; 9 : e002896 . Google Scholar CrossRef Search ADS PubMed 6 Ota T , Yerebakan H , Akashi H , Takayama H , Uriel N , Colombo PC et al. Continuous-flow left ventricular assist device exchange: clinical outcomes . J Hear Lung Transplant 2014 ; 33 : 65 – 70 . Google Scholar CrossRef Search ADS 7 Soleimani B , Stephenson ER , Price LC , El-Banayosy A , Pae WE. Clinical experience with sternotomy versus subcostal approach for exchange of HeartMate II left ventricular assist device . Ann Thorac Surg 2015 ; doi:10.1016/j.athoracsur.2015.05.033. 8 Gaffey AC , Chen CW , Chung JJ , Philips E , Wald J , Williams ML et al. Improved Approach with subcostal exchange of the heartmate ii left ventricular assist device: difference in on and off pump? Ann Thorac Surg 2017 ; doi:10.1016/j.athoracsur.2017.04.047. 9 Raman SV , Sahu A , Merchant AZ , Louis LB , Firstenberg MS , Sun B. Noninvasive assessment of left ventricular assist devices with cardiovascular computed tomography and impact on management . J Heart Lung Transplant 2010 ; 29 : 79 – 85 . Google Scholar CrossRef Search ADS PubMed 10 Mishkin JD , Enriquez JR , Meyer DM , Bethea BT , Thibodeau JT , Patel PC et al. Utilization of cardiac computed tomography angiography for the diagnosis of left ventricular assist device thrombosis . Circ Hear Fail 2012 ; 5 : e27 – 30 . Google Scholar CrossRef Search ADS 11 Uriel N , Morrison KA , Garan AR , Kato TS , Yuzefpolskaya M , Latif F et al. Development of a novel echocardiography ramp test for speed optimization and diagnosis of device thrombosis in continuous-flow left ventricular assist devices: the Columbia ramp study . J Am Coll Cardiol 2012 ; 60 : 1764 – 75 . Google Scholar CrossRef Search ADS PubMed 12 Hannan MM , Husain S , Mattner F , Danziger-Isakov L , Drew RJ , Corey GR et al. Working formulation for the standardization of definitions of infections in patients using ventricular assist devices . J Hear Lung Transplant 2011 ; doi:10.1016/j.healun.2011.01.717. 13 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 – 8 . Google Scholar CrossRef Search ADS PubMed 14 Adamson RM , Dembitsky WP , Baradarian S , Chammas J , May-Newman K , Chillcott S et al. HeartMate left ventricular assist system exchange: results and technical considerations . ASAIO J 2009 ; doi:10.1097/MAT.0b013e3181bd446a. 15 Akhter SA , Badami A , Murray M , Kohmoto T , Lozonschi L , Osaki S et al. Hospital readmissions after continuous-flow left ventricular assist device implantation: incidence, causes, and cost analysis . Ann Thorac Surg 2015 ; 100 : 884 – 9 . Google Scholar CrossRef Search ADS PubMed 16 Hasin T , Marmor Y , Kremers W , Topilsky Y , Severson CJ , Schirger JA et al. Readmissions after implantation of axial flow left ventricular assist device . J Am Coll Cardiol 2013 ; 61 : 153 – 63 . Google Scholar CrossRef Search ADS PubMed 17 Gordon RJ , Weinberg AD , Pagani FD , Slaughter MS , Pappas PS , Naka Y et al. Prospective, multicenter study of ventricular assist device infections . Circulation 2013 ; 127 : 691 –702. Google Scholar CrossRef Search ADS PubMed 18 Miller LW , Pagani FD , Russell SD , John R , Boyle AJ , Aaronson KD et al. Use of a continuous-flow device in patients awaiting heart transplantation . N Engl J Med 2007 ; 357 : 885 – 96 . Google Scholar CrossRef Search ADS PubMed 19 Slaughter MS , Rogers JG , Milano CA , Russell SD , Conte JV , Feldman D et al. Advanced heart failure treated with continuous-flow left ventricular assist device . N Engl J Med 2009 ; 361 : 2241 – 51 . Google Scholar CrossRef Search ADS PubMed 20 Chamogeorgakis T , Koval CE , Smedira NG , Starling RC , Gonzalez-Stawinski GV. Outcomes associated with surgical management of infections related to the HeartMate II left ventricular assist device: implications for destination therapy patients . J Hear Lung Transplant 2012 ; 31 : 904 – 6 . Google Scholar CrossRef Search ADS 21 Topkara VK , Kondareddy S , Malik F , Wang IW , Mann DL , Ewald GA 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 – 7 . Google Scholar CrossRef Search ADS PubMed 22 Zierer A , Melby SJ , Voeller RK , Guthrie TJ , Ewald GA , Shelton K et al. Late-onset driveline infections: the Achilles’ heel of prolonged left ventricular assist device support . Ann Thorac Surg 2007 ; 84 : 515 – 20 . Google Scholar CrossRef Search ADS PubMed 23 Stahovich M , Sundareswaran KS , Fox S , Hallian W , Blood P , Chen L et al. Reduce driveline trauma through stabilization and exit site management: 30 days feasibility results from the multicenter RESIST Study . ASAIO J 2016 ; 62 : 240 – 5 . Google Scholar CrossRef Search ADS PubMed 24 Singh A , Russo MJ , Valeroso TB , Anderson AS , Rich JD , Jeevanandam V et al. Modified HeartMate II driveline externalization technique significantly decreases incidence of infection and improves long-term survival . ASAIO J 2014 ; 60 : 613 . Google Scholar CrossRef Search ADS PubMed 25 Argenziano M , Catanese KA , Moazami N , Gardocki MT , Weinberg AD , Clavenna MW et al. The influence of infection on survival and successful transplantation in patients with left ventricular assist devices . J Heart Lung Transplant 1997 ;16:822–31. 26 Maltais S , Kilic A , Nathan S , Keebler M , Emani S , Ransom J et al. PREVENtion of HeartMate II Pump Thrombosis Through Clinical Management (PREVENT) . J Hear Lung Transplant 2016 ; 35 : S161 – 2 . Google Scholar CrossRef Search ADS 27 Levin AP , Uriel N , Takayama H , Mody KP , Ota T , Yuzefpolskaya M et al. Device exchange in HeartMate II recipients . ASAIO J 2015 ; 61 : 144 – 9 . Google Scholar CrossRef Search ADS PubMed 28 Taghavi S , Ward C , Jayarajan SN , Gaughan J , Wilson LM , Mangi AA. Surgical technique influences HeartMate II left ventricular assist device thrombosis . Ann Thorac Surg 2013 ; 96 : 1259 – 65 . Google Scholar CrossRef Search ADS PubMed 29 Shah P , Mehta VM , Cowger JA , Aaronson KD , Pagani FD. Diagnosis of hemolysis and device thrombosis with lactate dehydrogenase during left ventricular assist device support . J Hear Lung Transplant 2014 ; 33 : 102 – 4 . Google Scholar CrossRef Search ADS 30 Uriel N , Han J , Morrison KA , Nahumi N , Yuzefpolskaya M , Garan AR et al. Device thrombosis in HeartMate II continuous-flow left ventricular assist devices: a multifactorial phenomenon . J Hear Lung Transplant 2014 ; 33 : 51 – 9 . Google Scholar CrossRef Search ADS © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices) http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png European Journal of Cardio-Thoracic Surgery Oxford University Press

Late outcomes of subcostal exchange of the HeartMate II left ventricular assist device: a word of caution

Loading next page...
 
/lp/ou_press/late-outcomes-of-subcostal-exchange-of-the-heartmate-ii-left-oJPlKF4Rir
Publisher
Oxford University Press
Copyright
© The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
ISSN
1010-7940
eISSN
1873-734X
DOI
10.1093/ejcts/ezy159
Publisher site
See Article on Publisher Site

Abstract

Abstract OBJECTIVES Previous studies have shown the usefulness of the subcostal exchange of the HeartMate II left ventricular assist device for device malfunction. However, long-term data are still limited. METHODS Between March 2004 and July 2017, 41 of 568 (7.2%) patients who had received a HeartMate II implant at our institution had a device exchange via a subcostal incision. We summarized early and late outcomes. RESULTS Forty-one patients had a total of 48 subcostal pump exchanges. Indications for device exchange included device thrombosis (n = 31, 76%), driveline infection (n = 2, 5%) and driveline injury (n = 8, 19%). All of the procedures were successful, and there were no in-hospital deaths. A Kaplan–Meier survival curve showed 30-day and 1-year survival rates after subcostal exchange of 100% and 94.6%, respectively. However, 10 (25%) patients had left ventricular assist device-related infections following subcostal exchange that included 7 pump pocket infections and 3 driveline infections. Freedom from left ventricular assist device-related infection at 1 year after subcostal exchange was 79.3%. Thirteen (32%) patients had device malfunction due to pump thrombosis that required a 2nd device exchange. Seven patients had recurrent thrombosis. Three (7%) patients had a stroke. Freedom from device thrombosis and from a stroke event at 1 year was 74.4%. CONCLUSIONS Subcostal pump exchange can be safely performed. However, there is a substantial risk of infection and recurrent thrombosis. Careful follow-up for late complications is mandatory. Ventricular assist device , Subcostal exchange , Device thrombosis , Device infection INTRODUCTION Device malfunction including device thrombosis is a not uncommon and potentially fatal complication during continuous-flow left ventricular assist device (LVAD) support. Since the initial reports of the abrupt increase in the incidence of device thrombosis with the HeartMate II (HM II, Abbott, Abbott Park, IL, USA) [1, 2], a yearly thrombosis rate of about 10% has been noted by the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) reports [3]. The most recent report showed a higher incidence of device malfunctions involving the controller, battery and cable in addition to failure of the pump itself [4]. Once device malfunction is confirmed, early device exchange rather than watchful waiting is recommended to minimize the risk of adverse events [5]. The subcostal approach has been reported to be the preferred method for device exchange for patients who do not have inflow and outflow issues, because it is a less invasive procedure associated with shorter intensive care unit times and fewer postoperative complications than resternotomy [6–8]. However, data on the long-term clinical outcomes of this procedure are limited. In this study, our aim was to assess for late outcomes of patients who had subcostal HM II exchange. MATERIALS AND METHODS Patient selection This study was approved by the institutional review board of the Columbia University Medical Center. Between March 2004 and July 2017, 60 of 568 (10.6%) patients who had received a HM II implant at Columbia University Medical Center received a device exchange. Among them, the 41 (7.2%) patients who underwent subcostal exchange comprise our cohort of interest. Indication and surgical technique for subcostal exchange Once device malfunction is suspected, analysis of the log file is routinely performed. Radiographs are taken to detect driveline injury. Computed tomography angiography is used preoperatively to assess for kinking, malposition and thrombus in the inflow and outflow cannulas [9, 10]. For patients who have suspected device thrombosis, we routinely perform an echocardiographic ramp study [11] in addition to measuring serial serum lactate dehydrogenase and plasma-free haemoglobin levels. Our treatment algorithm for device thrombosis was reported previously [5]. Since June 2011, we have elected to perform a subcostal incision over a resternotomy for device exchange, unless there is a need to access the outflow or inflow cannulas (due to thrombus, infection or kinking of the graft) or to perform a concomitant cardiac procedure requiring sternotomy. Our surgical technique for subcostal HM II exchange was reported previously [6]. Briefly, a reverse J-shaped incision is made from the xiphoid process to the left mid-clavicular line to expose the pump from the bend relief site to the inflow arm. Cardiopulmonary bypass is initiated via femoral vessel cannulation. Most recently, a more limited incision (2 separate incisions) has been applied in order to minimize delayed wound healing (Fig. 1). Figure 1: View largeDownload slide A limited incision consisting of 2 separate incisions is now applied in order to minimize wound healing delay after subcostal exchange. Figure 1: View largeDownload slide A limited incision consisting of 2 separate incisions is now applied in order to minimize wound healing delay after subcostal exchange. Data collection and follow-up Medical records were reviewed for collection of baseline characteristics, postoperative complications and outcomes. Median support duration from initial subcostal exchange to time of analysis was 1876 days (1309–2292). Follow-up information was available and collected until 31 July 2017 for all patients. Postoperative complications included right ventricular failure, acute kidney injury, ventricular arrhythmia, gastrointestinal bleeding, LVAD-related infection, stroke and device thrombosis according to INTERMACS definitions. Driveline and pump pocket infections were confirmed by wound culture and radiological observation of fluid collections [12]. Stroke was confirmed by a brain imaging study. Duration to heart transplant was calculated as time from initial subcostal exchange. Statistical analysis Continuous variables are reported as mean ± standard deviation. The 95% confidence intervals (CIs) are additionally represented. Kaplan–Meier analysis was used to calculate survival rates and freedom from device complications with plots truncated after 3 years due to limited observations at later time points. Statistical significance was defined as a 2-sided α ≤ 0.05. Statistical analysis was performed using Stata 14 software (Stata Corp, College Station, TX, USA). RESULTS Patient baseline characteristics Baseline characteristics are summarized in Table 1. The mean age was 54.6 ± 13.5 years; 80% were men; 32% had ischaemic and 61% had dilated aetiologies; 63% were designated for bridge to transplant. Table 1: Baseline characteristics at the time of the primary subcostal device exchange n = 41 Age (years) 54.6 ± 13.5 Male (%) 33 (80) BMI (kg/m2) 27.3 ± 5.4 BSA (m2) 2.0 ± 0.2 Intention to treat  BTT 26 (63)  DT 15 (37) Aetiology of cardiomyopathy  Dilated 25 (61)  Ischaemic 13 (32)  Other 3 (7) Hypertension 21 (51) Diabetes mellitus 12 (29) Hyperlipidaemia 15 (37) Indication for exchange  Device thrombosis 31 (76)  Driveline infection 2 (5)  Driveline injury 8 (19) Incisional approach  Extended J-shaped incision 35 (85)  Modified 2-incision approach 6 (15) Support duration to subcostal exchange (days) 462 (178–778) Preoperative laboratory values  WBC (×1000/ml) 7.3 ± 2.0  Haemoglobin (g/dl) 10.6 ± 2.0  Haematocrit (%) 32.5 ± 5.5  Platelets (×1000/ml) 178.2 ± 68.0  LDH (U/l) 1080 (420–1753)  INR 1.6 (1.2–1.9)  BUN (mg/dl) 22.0 (15.0–31.0)  Creatinine (mg/dl) 1.3 (1.0–1.6) Pump parameters  Pump flow (l/min) 5.3 ± 0.9  Pump speed (rpm) 9150 ± 500  Pulsatility index 4.9 ± 1.8  Power (W) 5.8 ± 1.5 CPB time (min) 22 (12–27) Length of ICU stay (days) 5 (4–8) n = 41 Age (years) 54.6 ± 13.5 Male (%) 33 (80) BMI (kg/m2) 27.3 ± 5.4 BSA (m2) 2.0 ± 0.2 Intention to treat  BTT 26 (63)  DT 15 (37) Aetiology of cardiomyopathy  Dilated 25 (61)  Ischaemic 13 (32)  Other 3 (7) Hypertension 21 (51) Diabetes mellitus 12 (29) Hyperlipidaemia 15 (37) Indication for exchange  Device thrombosis 31 (76)  Driveline infection 2 (5)  Driveline injury 8 (19) Incisional approach  Extended J-shaped incision 35 (85)  Modified 2-incision approach 6 (15) Support duration to subcostal exchange (days) 462 (178–778) Preoperative laboratory values  WBC (×1000/ml) 7.3 ± 2.0  Haemoglobin (g/dl) 10.6 ± 2.0  Haematocrit (%) 32.5 ± 5.5  Platelets (×1000/ml) 178.2 ± 68.0  LDH (U/l) 1080 (420–1753)  INR 1.6 (1.2–1.9)  BUN (mg/dl) 22.0 (15.0–31.0)  Creatinine (mg/dl) 1.3 (1.0–1.6) Pump parameters  Pump flow (l/min) 5.3 ± 0.9  Pump speed (rpm) 9150 ± 500  Pulsatility index 4.9 ± 1.8  Power (W) 5.8 ± 1.5 CPB time (min) 22 (12–27) Length of ICU stay (days) 5 (4–8) Values are represented as mean ± SD, median (Q1–Q3) or n (%). BMI: body mass index; BSA: body surface area; BTT: bridge to transplant; BUN: blood urea nitrogen; CPB: cardiopulmonary bypass; DT: destination therapy; ICU: intensive care unit; INR: international normalized ratio; LDH: lactate dehydrogenase; WBC: white blood cells. Table 1: Baseline characteristics at the time of the primary subcostal device exchange n = 41 Age (years) 54.6 ± 13.5 Male (%) 33 (80) BMI (kg/m2) 27.3 ± 5.4 BSA (m2) 2.0 ± 0.2 Intention to treat  BTT 26 (63)  DT 15 (37) Aetiology of cardiomyopathy  Dilated 25 (61)  Ischaemic 13 (32)  Other 3 (7) Hypertension 21 (51) Diabetes mellitus 12 (29) Hyperlipidaemia 15 (37) Indication for exchange  Device thrombosis 31 (76)  Driveline infection 2 (5)  Driveline injury 8 (19) Incisional approach  Extended J-shaped incision 35 (85)  Modified 2-incision approach 6 (15) Support duration to subcostal exchange (days) 462 (178–778) Preoperative laboratory values  WBC (×1000/ml) 7.3 ± 2.0  Haemoglobin (g/dl) 10.6 ± 2.0  Haematocrit (%) 32.5 ± 5.5  Platelets (×1000/ml) 178.2 ± 68.0  LDH (U/l) 1080 (420–1753)  INR 1.6 (1.2–1.9)  BUN (mg/dl) 22.0 (15.0–31.0)  Creatinine (mg/dl) 1.3 (1.0–1.6) Pump parameters  Pump flow (l/min) 5.3 ± 0.9  Pump speed (rpm) 9150 ± 500  Pulsatility index 4.9 ± 1.8  Power (W) 5.8 ± 1.5 CPB time (min) 22 (12–27) Length of ICU stay (days) 5 (4–8) n = 41 Age (years) 54.6 ± 13.5 Male (%) 33 (80) BMI (kg/m2) 27.3 ± 5.4 BSA (m2) 2.0 ± 0.2 Intention to treat  BTT 26 (63)  DT 15 (37) Aetiology of cardiomyopathy  Dilated 25 (61)  Ischaemic 13 (32)  Other 3 (7) Hypertension 21 (51) Diabetes mellitus 12 (29) Hyperlipidaemia 15 (37) Indication for exchange  Device thrombosis 31 (76)  Driveline infection 2 (5)  Driveline injury 8 (19) Incisional approach  Extended J-shaped incision 35 (85)  Modified 2-incision approach 6 (15) Support duration to subcostal exchange (days) 462 (178–778) Preoperative laboratory values  WBC (×1000/ml) 7.3 ± 2.0  Haemoglobin (g/dl) 10.6 ± 2.0  Haematocrit (%) 32.5 ± 5.5  Platelets (×1000/ml) 178.2 ± 68.0  LDH (U/l) 1080 (420–1753)  INR 1.6 (1.2–1.9)  BUN (mg/dl) 22.0 (15.0–31.0)  Creatinine (mg/dl) 1.3 (1.0–1.6) Pump parameters  Pump flow (l/min) 5.3 ± 0.9  Pump speed (rpm) 9150 ± 500  Pulsatility index 4.9 ± 1.8  Power (W) 5.8 ± 1.5 CPB time (min) 22 (12–27) Length of ICU stay (days) 5 (4–8) Values are represented as mean ± SD, median (Q1–Q3) or n (%). BMI: body mass index; BSA: body surface area; BTT: bridge to transplant; BUN: blood urea nitrogen; CPB: cardiopulmonary bypass; DT: destination therapy; ICU: intensive care unit; INR: international normalized ratio; LDH: lactate dehydrogenase; WBC: white blood cells. Indications for subcostal exchange included device thrombosis (n = 31, 76%), driveline infection (n = 2, 5%) and driveline injury (n = 8, 19%). The extended J incision was used in 35 (85%) patients, whereas 6 underwent a modified 2-incision approach. Median duration on LVAD support until subcostal exchange was 462 (178–778) days. Early outcomes There were no in-hospital deaths after subcostal exchange. Early postoperative complications included right ventricular failure (n = 2), acute kidney injury (n = 4), ventricular tachycardia (n = 5), gastrointestinal bleeding (n = 2) and amiodarone-induced thyrotoxicosis (n = 1). Follow-up complications Freedom from LVAD-related infection 30 days and 1 year after subcostal exchange was 95.1% and 79.3%, respectively (Fig. 2A). Ten (25%) patients had pump pocket or driveline infection following subcostal exchange (Table 2). Two patients had early pump pocket infection during the indexed hospitalization and underwent surgical incision and drainage. The remaining 8 LVAD-related infections occurred a mean of 462 (95% CI 22–903) days after subcostal exchange, with 3 patients who developed infection after 1 year. Four required incision and drainage with vacuum-assisted closure therapy, all of whom had chronic infection and required later surgical debridement. One patient had an LVAD explant and subsequent reinsertion 2 weeks after the infection resolved. The other 3 patients who had isolated driveline infection were managed with long-term antibiotic therapy and did not have recurrent infection. Staphylococcus genus and Pseudomonas aeruginosa were the most commonly detected pathogens on wound culture (Table 2). Table 2: Left ventricular assist device-related infection after subcostal exchange n = 10 LVAD-related infection  Driveline infection 3  Pump pocket infection 7 Pathogens  Staphylococcus   Methicillin-sensitive 1   Methicillin-resistant 1   Staphylococcus lugdunensis 1  Pseudomonas aeruginosa 3  Serratia marcescens 2  Enterococcus faecalis (formerly Enterobacter faecalis) 1  Culture negative 1 n = 10 LVAD-related infection  Driveline infection 3  Pump pocket infection 7 Pathogens  Staphylococcus   Methicillin-sensitive 1   Methicillin-resistant 1   Staphylococcus lugdunensis 1  Pseudomonas aeruginosa 3  Serratia marcescens 2  Enterococcus faecalis (formerly Enterobacter faecalis) 1  Culture negative 1 LVAD: left ventricular assist device. Table 2: Left ventricular assist device-related infection after subcostal exchange n = 10 LVAD-related infection  Driveline infection 3  Pump pocket infection 7 Pathogens  Staphylococcus   Methicillin-sensitive 1   Methicillin-resistant 1   Staphylococcus lugdunensis 1  Pseudomonas aeruginosa 3  Serratia marcescens 2  Enterococcus faecalis (formerly Enterobacter faecalis) 1  Culture negative 1 n = 10 LVAD-related infection  Driveline infection 3  Pump pocket infection 7 Pathogens  Staphylococcus   Methicillin-sensitive 1   Methicillin-resistant 1   Staphylococcus lugdunensis 1  Pseudomonas aeruginosa 3  Serratia marcescens 2  Enterococcus faecalis (formerly Enterobacter faecalis) 1  Culture negative 1 LVAD: left ventricular assist device. Figure 2: View largeDownload slide Freedom from adverse events: (A) left ventricular assist device-related infection; (B) device thrombosis and stroke. CI: confidence interval. Figure 2: View largeDownload slide Freedom from adverse events: (A) left ventricular assist device-related infection; (B) device thrombosis and stroke. CI: confidence interval. Freedom from device thrombosis and a stroke event 30 days and 1 year after subcostal exchange was 100% and 74.4%, respectively (Fig. 2B). Three (7%) patients suffered a stroke at 17, 28 and 86 days after the exchange. Thirteen (32%) patients had recurrent device malfunction requiring surgical interventions at a mean of 454 (95% CI 118–789) days after the initial subcostal exchange. Twelve had device thrombosis, 7 of whom had recurrent thrombosis (the indication for the initial and 2nd device exchanges was device thrombosis). These patients required a 2nd device exchange via a subcostal exchange (n = 6), a device exchange via resternotomy (n = 4) or a heart transplant (n = 2). One patient had driveline injury after the exchange and required a resubcostal exchange. Freedom from recurrent device malfunction at 1 year was 88%. Late outcomes Of 41 patients, 21 (51%) had a heart transplant a mean of 268 (95% CI 175–361) days after the initial subcostal exchange. The Kaplan–Meier survival curve showed 30-day and 1-year survival rates after subcostal exchange of 100% and 94.6%, respectively (Fig. 3). Figure 3: View largeDownload slide Survival after subcostal exchange. CI: confidence interval. Figure 3: View largeDownload slide Survival after subcostal exchange. CI: confidence interval. DISCUSSION We examined early and late outcomes after subcostal device exchange for HM II device malfunction. Many studies have reported the subcostal technique to be a procedure with a low early mortality rate [13, 14]. Likewise, there were no in-hospital deaths with the subcostal exchange in our study, further supporting the safeness of this surgical technique when device exchange is warranted. However, LVAD-related infections and recurrent device malfunction are major causes of morbidity during the late follow-up period. With the rising frequency and duration of support on LVAD therapy, preventive measures and appropriate management of these device complications are necessary. Device-related infection is one of the most common causes for readmission for patients on LVAD support, with a reported incidence in up to 59% of patients [15–20]. Driveline infection is the most common LVAD-related infection [17] because it is often the site of entry for pathogens. Staphylococci are the most common pathogens reported, followed by pseudomonads [17, 21, 22]. If it is not properly treated, infection of the driveline can subsequently invade the pump pocket and cause systemic bloodstream complications, which can result in death. Although device-related infections are well-described in the literature, our study is the first to assess the incidence of infection as a consequence of device exchange. In our cohort, 25% of patients had an LVAD-related infection after subcostal exchange. Notably, 70% of these patients suffered from pump pocket infection that was not related to driveline infection, including 2 patients who had early pocket infection. Furthermore, it is important to note that the majority of device-related infections occurred after the patients were discharged following subcostal exchange. Prior studies have mentioned that most LVAD infections occur out of the hospital as a result of trauma at the driveline site [21, 22]. This result speaks to the fact that, whereas device exchange is an invasive procedure that can increase the susceptibility of patients to infection, the high rate of infection is inevitable largely due to the percutaneous nature of the HM II devices. Techniques to stabilize the driveline and minimize trauma are currently in development [23, 24]. Moreover, we thought that some of the late pocket infections were related to delayed wound healing resulting from the extended J incision with transection of the rectus muscles, fascia and ribs. These patients returned with probable pump pocket contamination from the incision. Based on our observations, we now perform a more limited 2-incision approach, as was done for 6 patients in this study, to minimize the opportunity and entry site for infection. Since we implemented this technique, we have not seen any type of pump pocket infection. The best treatment for LVAD-associated infections is device explant and/or heart transplant [25], but this option is often not available. Overall, patients in our study with driveline and pump pocket infections were managed successfully with antibiotic therapy and surgical debridement with or without vacuum-assisted closure. Device thrombosis is another detrimental complication of LVAD therapy that has become of particular concern in recent years. Since 2011, the incidence of HM II device thrombosis has increased [1, 2]. Adherence to a standardized practice for clinical management was shown to reduce the risk of early device thrombosis in the PREVENT clinical trial [26]; however, many thromboembolic events also occur as late complications in patients on LVAD support. Once device thrombosis occurs, early device exchange should be considered rather than a watch and wait approach [5]. Although subcostal exchange is our preferred technique for device exchange, this approach carries the risk of missing a thrombus outside the pump. Furthermore, when pump thrombosis is precipitated by anatomical abnormalities of the device (such as inflow malpositioning or outflow kinking), a resternotomy can help to correct the anomaly and minimize the risk of recurrence. We previously reported a high rate of recurrent thrombosis (31%) in patients who had a prior device exchange (subcostal or sternotomy) for thrombosis [27]. Similarly, in this study, 7 of 29 (24%) patients had a recurrent thrombotic event and underwent 2nd device exchange or explant. Recent studies suggest that device positioning, particularly inflow graft angulation and pump pocket depth, influence the risk of device thrombosis; hence a careful surgical technique should be used to ensure proper positioning of the LVAD at time of implant [28]. Moreover, there is an association between these 2 major complications of device exchange. Heightened inflammation as a result of infection can predispose a patient to a procoagulant status and increase the risk of having a thromboembolic event [29, 30]. Among the 12 patients who had device thrombosis requiring recurrent device exchange, 3 (25%) had a device-related infection within 2 months prior to the thrombotic event. Limitations Our study has several limitations. First, it is a single-centre retrospective study. Second, there are currently no standard criteria for infection in patients on LVAD support; hence the criteria for infection remains largely variable among studies. A consistent definition is needed in order to develop a better method for prevention and management of LVAD-associated infections. Furthermore, although we have focused only on device-specific complications, several other factors including gastrointestinal bleeding and systemic infection are large contributors to the morbidity and mortality of patients on LVAD support. CONCLUSION In conclusion, subcostal exchange is a safe procedure that can be performed with no in-hospital deaths and good long-term outcomes. However, a high prevalence of device-associated infections and thromboembolism persist following device exchange. Careful management of these complications is mandatory. Conflict of interest: Yoshifumi Naka has received consulting fees from Abbott Inc. The remaining authors have no conflicts of interest to disclose. REFERENCES 1 Starling RC , Moazami N , Silvestry SC , Ewald G , Rogers JG , Milano CA et al. Unexpected abrupt increase in left ventricular assist device thrombosis . N Engl J Med 2014 ; 370 : 33 – 40 . Google Scholar CrossRef Search ADS PubMed 2 Kirklin JK , Naftel DC , Kormos RL , Pagani FD , Myers SL , Stevenson LW et al. Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) analysis of pump thrombosis in the HeartMate II left ventricular assist device . J Hear Lung Transplant 2014 ; 33 : 12 – 22 . Google Scholar CrossRef Search ADS 3 Kirklin JK , Naftel DC , Pagani FD , Kormos RL , Stevenson LW , Blume ED et al. Seventh INTERMACS annual report: 15,000 patients and counting . J Hear Lung Transplant 2015 ; 34 : 1495 – 504 . Google Scholar CrossRef Search ADS 4 Kormos RL , McCall M , Althouse A , Lagazzi L , Schaub R , Kormos MA et al. Left ventricular assist device malfunctions: it is more than just the pump . Circulation 2017 ; 136 : 1714 – 25 . Google Scholar CrossRef Search ADS PubMed 5 Levin AP , Saeed O , Willey JZ , Levin CJ , Fried JA , Patel SR et al. Watchful waiting in continuous-flow left ventricular assist device patients with ongoing hemolysis is associated with an increased risk for cerebrovascular accident or death . Circ Heart Fail 2016 ; 9 : e002896 . Google Scholar CrossRef Search ADS PubMed 6 Ota T , Yerebakan H , Akashi H , Takayama H , Uriel N , Colombo PC et al. Continuous-flow left ventricular assist device exchange: clinical outcomes . J Hear Lung Transplant 2014 ; 33 : 65 – 70 . Google Scholar CrossRef Search ADS 7 Soleimani B , Stephenson ER , Price LC , El-Banayosy A , Pae WE. Clinical experience with sternotomy versus subcostal approach for exchange of HeartMate II left ventricular assist device . Ann Thorac Surg 2015 ; doi:10.1016/j.athoracsur.2015.05.033. 8 Gaffey AC , Chen CW , Chung JJ , Philips E , Wald J , Williams ML et al. Improved Approach with subcostal exchange of the heartmate ii left ventricular assist device: difference in on and off pump? Ann Thorac Surg 2017 ; doi:10.1016/j.athoracsur.2017.04.047. 9 Raman SV , Sahu A , Merchant AZ , Louis LB , Firstenberg MS , Sun B. Noninvasive assessment of left ventricular assist devices with cardiovascular computed tomography and impact on management . J Heart Lung Transplant 2010 ; 29 : 79 – 85 . Google Scholar CrossRef Search ADS PubMed 10 Mishkin JD , Enriquez JR , Meyer DM , Bethea BT , Thibodeau JT , Patel PC et al. Utilization of cardiac computed tomography angiography for the diagnosis of left ventricular assist device thrombosis . Circ Hear Fail 2012 ; 5 : e27 – 30 . Google Scholar CrossRef Search ADS 11 Uriel N , Morrison KA , Garan AR , Kato TS , Yuzefpolskaya M , Latif F et al. Development of a novel echocardiography ramp test for speed optimization and diagnosis of device thrombosis in continuous-flow left ventricular assist devices: the Columbia ramp study . J Am Coll Cardiol 2012 ; 60 : 1764 – 75 . Google Scholar CrossRef Search ADS PubMed 12 Hannan MM , Husain S , Mattner F , Danziger-Isakov L , Drew RJ , Corey GR et al. Working formulation for the standardization of definitions of infections in patients using ventricular assist devices . J Hear Lung Transplant 2011 ; doi:10.1016/j.healun.2011.01.717. 13 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 – 8 . Google Scholar CrossRef Search ADS PubMed 14 Adamson RM , Dembitsky WP , Baradarian S , Chammas J , May-Newman K , Chillcott S et al. HeartMate left ventricular assist system exchange: results and technical considerations . ASAIO J 2009 ; doi:10.1097/MAT.0b013e3181bd446a. 15 Akhter SA , Badami A , Murray M , Kohmoto T , Lozonschi L , Osaki S et al. Hospital readmissions after continuous-flow left ventricular assist device implantation: incidence, causes, and cost analysis . Ann Thorac Surg 2015 ; 100 : 884 – 9 . Google Scholar CrossRef Search ADS PubMed 16 Hasin T , Marmor Y , Kremers W , Topilsky Y , Severson CJ , Schirger JA et al. Readmissions after implantation of axial flow left ventricular assist device . J Am Coll Cardiol 2013 ; 61 : 153 – 63 . Google Scholar CrossRef Search ADS PubMed 17 Gordon RJ , Weinberg AD , Pagani FD , Slaughter MS , Pappas PS , Naka Y et al. Prospective, multicenter study of ventricular assist device infections . Circulation 2013 ; 127 : 691 –702. Google Scholar CrossRef Search ADS PubMed 18 Miller LW , Pagani FD , Russell SD , John R , Boyle AJ , Aaronson KD et al. Use of a continuous-flow device in patients awaiting heart transplantation . N Engl J Med 2007 ; 357 : 885 – 96 . Google Scholar CrossRef Search ADS PubMed 19 Slaughter MS , Rogers JG , Milano CA , Russell SD , Conte JV , Feldman D et al. Advanced heart failure treated with continuous-flow left ventricular assist device . N Engl J Med 2009 ; 361 : 2241 – 51 . Google Scholar CrossRef Search ADS PubMed 20 Chamogeorgakis T , Koval CE , Smedira NG , Starling RC , Gonzalez-Stawinski GV. Outcomes associated with surgical management of infections related to the HeartMate II left ventricular assist device: implications for destination therapy patients . J Hear Lung Transplant 2012 ; 31 : 904 – 6 . Google Scholar CrossRef Search ADS 21 Topkara VK , Kondareddy S , Malik F , Wang IW , Mann DL , Ewald GA 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 – 7 . Google Scholar CrossRef Search ADS PubMed 22 Zierer A , Melby SJ , Voeller RK , Guthrie TJ , Ewald GA , Shelton K et al. Late-onset driveline infections: the Achilles’ heel of prolonged left ventricular assist device support . Ann Thorac Surg 2007 ; 84 : 515 – 20 . Google Scholar CrossRef Search ADS PubMed 23 Stahovich M , Sundareswaran KS , Fox S , Hallian W , Blood P , Chen L et al. Reduce driveline trauma through stabilization and exit site management: 30 days feasibility results from the multicenter RESIST Study . ASAIO J 2016 ; 62 : 240 – 5 . Google Scholar CrossRef Search ADS PubMed 24 Singh A , Russo MJ , Valeroso TB , Anderson AS , Rich JD , Jeevanandam V et al. Modified HeartMate II driveline externalization technique significantly decreases incidence of infection and improves long-term survival . ASAIO J 2014 ; 60 : 613 . Google Scholar CrossRef Search ADS PubMed 25 Argenziano M , Catanese KA , Moazami N , Gardocki MT , Weinberg AD , Clavenna MW et al. The influence of infection on survival and successful transplantation in patients with left ventricular assist devices . J Heart Lung Transplant 1997 ;16:822–31. 26 Maltais S , Kilic A , Nathan S , Keebler M , Emani S , Ransom J et al. PREVENtion of HeartMate II Pump Thrombosis Through Clinical Management (PREVENT) . J Hear Lung Transplant 2016 ; 35 : S161 – 2 . Google Scholar CrossRef Search ADS 27 Levin AP , Uriel N , Takayama H , Mody KP , Ota T , Yuzefpolskaya M et al. Device exchange in HeartMate II recipients . ASAIO J 2015 ; 61 : 144 – 9 . Google Scholar CrossRef Search ADS PubMed 28 Taghavi S , Ward C , Jayarajan SN , Gaughan J , Wilson LM , Mangi AA. Surgical technique influences HeartMate II left ventricular assist device thrombosis . Ann Thorac Surg 2013 ; 96 : 1259 – 65 . Google Scholar CrossRef Search ADS PubMed 29 Shah P , Mehta VM , Cowger JA , Aaronson KD , Pagani FD. Diagnosis of hemolysis and device thrombosis with lactate dehydrogenase during left ventricular assist device support . J Hear Lung Transplant 2014 ; 33 : 102 – 4 . Google Scholar CrossRef Search ADS 30 Uriel N , Han J , Morrison KA , Nahumi N , Yuzefpolskaya M , Garan AR et al. Device thrombosis in HeartMate II continuous-flow left ventricular assist devices: a multifactorial phenomenon . J Hear Lung Transplant 2014 ; 33 : 51 – 9 . Google Scholar CrossRef Search ADS © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices)

Journal

European Journal of Cardio-Thoracic SurgeryOxford University Press

Published: Apr 10, 2018

References