Christoph Haller

Double tunnel technique for the LVAD driveline: improved management regarding driveline infections

A driveline exit site infection is a serious and common complication in long-term left ventricular assist device (LVAD) support. To reduce the incidence and severity of late driveline infections, we modified our surgical technique (double tunnel), and compared it to the conventional short and straight driveline tunnel technique (conventional). We analyzed 43 consecutive patients (37 HeartMate II; 6 Ventrassist) regarding late onset driveline exit site infections after using the surgical driveline tunnel technique after successful LVAD implantation. Of these 43 patients, 11 were treated with the conventional short and straight driveline tunnel technique (conventional), while 32 patients were treated with the modified long subfascial, C-shaped technique (double tunnel). We observed slightly fewer superficial driveline exit site infections in the double tunnel group, even though the difference was not statistically significant (0.638 vs. 1.148 infections/1,000 patient-days; Pxa0=xa00.22). There were also insignificantly fewer surgical interventions because of exit site infections in the double tunnel group (0.159 vs. 0.581 revisions/1,000 patient-days; Pxa0=xa00.18). The double tunnel technique offers more surgical options in the case of driveline exit site infections. Due to the long subfascial tunnel, the infected site can be separated from the new driveline exit site, and vacuum-assisted closure therapy can be applied to the infected area. In conclusion, we recommend using the double tunnel driveline technique because of the low infection rate and better treatment options in the case of driveline exit site infection.

Impella 5.0 Support in INTERMACS II Cardiogenic Shock Patients Using Right and Left Axillary Artery Access

The catheter-based Impella 5.0 left ventricular assist device (LVAD) is a powerful and less invasive alternative for patients in cardiogenic shock. The use of this device as a primary mechanical circulatory support strategy in INTERMACS II patients should be evaluated. From April 2014 to August 2014, eight Impella 5.0 devices were implanted in seven patients via the axillary artery access (six right and two left). We analyzed the outcome of the four patients in whom the Impella 5.0 device was implanted for the purpose of primary stabilization of cardiogenic shock (INTERMACS II). The remaining three patients had a contraindication for a permanent LVAD and received the device for prolonged weaning from extracorporeal life support (ECLS) system. The implantation of the Impella 5.0 was technically successful in all patients and resulted in the stabilization of the clinical situation. All four patients could be bridged to a long-term device (nu2009=u20093) or to cardiac recovery (nu2009=u20091). In one patient, 2 days of ECLS support was necessary because of pump thrombosis after 31 days of Impella 5.0 support. One patient with bronchopneumonia had the Impella 5.0 exchanged from the right to the left axillary artery after 22 days of support because of the progressive loss of purge flow and the need for longer bridging to a permanent LVAD. The last patient was supported for giant-cell myocarditis for 22 days and bridged to cardiac recovery. All patients were transferred to the intensive care unit with the Impella device in place. In INTERMACS II situations, the implantation of the Impella 5.0 via the right or left axillary access allowed additional time for decision making. Early patient mobilization, including walking with the Impella device in place, optimized the conditions for either weaning or the implantation of a permanent LVAD. This novel technique of left axillary approach leads to more flexibility in the case of anatomical- or device-related contraindications to right-side access, or when the device needs to be exchanged while continuous support is necessary.

Extracorporeal life support prior to left ventricular assist device implantation leads to improvement of the patients INTERMACS levels and outcome

Background The objective of this study was to evaluate the outcome of left ventricular assist device (LVAD) implantation after initial extracorporeal life support (ECLS) in patients with cardiogenic shock and the incidence of post implantation right ventricular failure. Methods & results All patients on ECLS therapy for cardiogenic shock prior to LVAD implantation (n = 15) between October 2011 and January 2014 were analyzed. Baseline patient characteristics, as well as detailed pre-operative treatment and postoperative outcome data were collected retrospectively. At time of admission to our unit all patients were classified INTERMACS II or higher (12 [80%] INTERMACS I). Improvement to INTERMACS III temporary cardiac support (TCS) at time of LVAD implantation was successful in 14 patients (93.3%). End-organ function recovered during ECLS support. No patient needed ongoing ECLS or additional right ventricular support after LVAD implantation. Both in-hospital and 30-day mortality was 6.7% (n = 1). The median duration of LVAD support was 687.9 ± 374.5 days. At the end of the study (follow-up 810.7 +/- 338.9 days), 13 (86.7%) patients were alive. The majority of patients (10 [66.7%]) remained on LVAD support. Transplantation could be performed in 1 (6.7%) patient, 2 (13.3%) patients could be successfully weaned. Conclusion LVAD implantation in ECLS patients leads to improvement of INTERMACS level to INTERMACS III TCS status. Excellent mid-term survival comparable to true INTERMACS III-IV patients could be shown. ECLS prior to LVAD as a bridge-to-bridge therapy may help to lower mortality in primarily unstable patients.

Cell-Wall Glycolipid Mutations and Their Effects on Virulence of E. faecalis in a Rat Model of Infective Endocarditis

Enterococci are among the major pathogens implicated in cardiac infections and biofilm formation. E. faecalis has been shown to play an important role in infectious endocarditis. Several distinct mechanisms for biofilm formation have been identified in E. faecalis. Our group has previously characterized two distinct bacterial glucosyltransferases playing key roles in the production of the major cell wall glycolipids and leading to reduced biofilm production. To assess if this mechanism is involved in the pathogenesis of enterococcal endocarditis we compared the wild-type strain of E. faecalis 12030 with two mutants in gene EF2891 and EF2890 respectively in a rat model of infective endocarditis. The results showed less endocarditic lesions and reduced colony counts per vegetation in the two mutants. indicating that the modification of bacterial surface lipids results in significantly reduced virulence in infective endocarditis. These results underscore the important role of biofilm formation in the pathogenicity of enterococcal endocarditis and may indicate an interesting target for novel therapeutic strategies.

One-staged aptamer-based isolation and application of endothelial progenitor cells in a porcine myocardial infarction model.

A multitude of stem cell types has been extensively studied and used for myocardial regenerative therapy. Amongst these endothelial progenitor cells form a promising source. In our present study, we investigated a one-staged approach for isolation and application of autologous endothelial progenitor cells in a pig model of myocardial infarction. Endothelial progenitor cell isolation was performed by immediately preprocedural bone marrow aspiration and consecutive positive selection by aptamer-based magnetic cell sorting. Animals were divided in three groups receiving endothelial progenitor cells, saline, or no intramyocardial injection respectively. Postprocedural follow-up consisted of weekly echocardiographic evaluations. Postmortem histological analysis after four weeks focused on detection of transplanted PKH26-positive endothelial progenitor cells and neovascularization within the infarcted myocardium. A significant difference in left ventricular ejection fraction could not be shown between the three groups. PKH26-stained endothelial progenitor cells could be found in the endothelial progenitor cells transplanted group, although detection was scarce. Large-sized capillaries were found to be significantly more in endothelial progenitor cells treated myocardium. The one-stage approach of endothelial progenitor cells isolation and application presented herein offers a new therapeutic concept. Even though a beneficial impact on myocardial function could not be assessed, increased neovascularization may indicate positive effects on remodeling processes. Being able to harvest endothelial progenitor cells right before application provides a wider scope of action in urgent cases.

Geometry and growth of the reconstructed aorta in patients with hypoplastic left heart syndrome and variants

Objective: The interdigitating technique in aortic arch reconstruction in hypoplastic left heart syndrome and variants (HLHS) reduces the recoarctation rate. Little is known on aortic arch growth characteristics and resulting clinical impact. Methods: A total of 139 patients with HLHS underwent staged palliation between 2007 and 2014; 73 patients underwent arch reconstruction. Dimensions of ascending aorta, transverse arch, interdigitating anastomosis, and descending aorta in pre‐stage II and pre‐Fontan angiograms were measured. Aortic arch dimensions were analyzed. Ventricular and atrioventricular valve function were assessed. Results: Diameters increased in all segments between pre‐stage II and pre‐Fontan (P < .0005). The z scores remained unchanged in all segments but the descending aorta that was significantly larger pre‐Fontan (P = .039). Dimensions and z scores between pre‐stage II and pre‐Fontan correlated in proximal segments, but not at and distal to the interdigitating anastomosis. Pronounced tapering occurred between the transverse arch and the interdigitating anastomosis. Arch intervention of any type was performed in 7 (9.6%), and intervention for recoarctation in 3 (4.1%) patients. Conclusions: The aortic arch after reconstruction with the interdigitating technique differs from normal. Growth was proportional with no further geometrical distortion. Recoarctation and reintervention rate is low. Further improvement may be achieved by optimizing patch configuration and material.

Impella 5.0 as a Second-Line Mechanical Circulatory Support Strategy After Extracorporeal Life Support.

The catheter-based Impella 5.0 left ventricular assist device is a powerful and less invasive alternative for patients in cardiogenic shock. The use as second-line therapy in patients with precedent extracorporeal life support (ECLS) has not been described before now. We analyzed our experience of consecutive patients treated with this alternative strategy. From April 2014 to December 2014, eight patients had been implanted as a second-line option after ECLS support. The reason for the change from ECLS to Impella 5.0 was absence of cardiac recovery for primary weaning and complications of ECLS therapy. The mean time of ECLS support prior to Impella implantation was 12u2009±u20097 days. The implantation of the Impella 5.0/CP was technically successful in all patients, and the ECLS could be explanted in all eight patients who received Impella implantation as a second-line treatment. The second-line Impella 5.0 therapy resulted in two patients who turned into left ventricular assist device (LVAD) candidates, two primary weaning candidates, and four patients who died in the setting of sepsis or absent cardiac recovery and contraindications for durable LVAD therapy. Thereby, the overall hospital discharge survival as well as the 180-day survival was 50% for Impella 5.0 implantations as second-line procedure after ECLS. The latest follow-up survival of this second-line strategy after ECLS was three out of eight, as one patient died after 299 days of LVAD support due to sepsis. The use of Impella 5.0 constitutes a possible second-line therapeutic option for those patients who do not show cardiac recovery during prolonged ECLS support or suffer from complications of ECLS therapy. This treatment allows additional time for decisions regarding cardiac recovery or indication for durable LVAD therapy.

Hemocompatibility of Axial Versus Centrifugal Pump Technology in Mechanical Circulatory Support Devices.

The hemocompatible properties of rotary blood pumps commonly used in mechanical circulatory support (MCS) are widely unknown regarding specific biocompatibility profiles of different pump technologies. Therefore, we analyzed the hemocompatibility indicating markers of an axial flow and a magnetically levitated centrifugal device within an in vitro mock loop. The HeartMate II (HM II; nu2009=u20093) device and a CentriMag (CM; nu2009=u20093) adult pump were investigated in a human whole blood mock loop for 360u2009min using the MCS devices as a driving component. Blood samples were analyzed by enzyme-linked immunosorbent assay for markers of coagulation, complement system, and inflammatory response. There was a time-dependent activation of the coagulation (thrombin-antithrombin complexes [TAT]), complement (SC5b-9), and inflammation system (polymorphonuclear [PMN] elastase) in both groups. The mean value of TAT (CM: 4.0u2009μg/L vs. 29.4u2009μg/L, Pu2009<u20090.001; HM II: 4.5u2009μg/L vs. 232.2u2009μg/L, Pu2009<u20090.05) and PMN elastase (CM: 53.4u2009ng/mL vs. 253.8u2009ng/mL, Pu2009<u20090.05; HM II: 28.0u2009ng/mL vs. 738.8u2009ng/mL, Pu2009<u20090.001) significantly increased from baseline until the end of the experiments (360u2009min). After 360u2009min, TAT and PMN values were significantly higher in the HM II group compared with the values in the CM adult group. The values of SC5b-9 increased from baseline to 360u2009min in the CM group (CM: 141.8u2009ng/mL vs. 967.9u2009ng/mL, Pu2009<u20090.05) and the HM II group. However, the increase within the HM II group (97.3 vs. 2462.0, Pu2009=u20090.06) and the comparison of the 360-min values between CM group and HM II group did not reach significance (Pu2009=u20090.18). The activation of complement, coagulation, and inflammation system showed a time-dependent manner in both devices. The centrifugal CM device showed significantly lower activation of coagulation and inflammation than that of the HM II axial flow pump. Both HM II and CM have demonstrated an acceptable hemocompatibility profile in patients. However, there is a great opportunity to gain a clinical benefit by developing techniques to lower the blood surface interaction within both pump technologies and a magnetically levitated centrifugal pump design might be superior.

Beneficial Effects On Cardiac Performance and Cardioprotective Properties of Milrinone after Cold Ischemia

Background: Cold Ischemia-Reperfusion Injury (CIRI) is regarded as the major cause of early graft dysfunction after cardiac transplantations and is associated with rejection episodes. Consequently, it is one of the main therapeutic targets in order to improve survival after heart transplantation. The aim of this study was to evaluate hemodynamic effects of milrinone and its influence on the markers of myocardial damage when used in a piglet working heart model with a cold ischemia-reperfusion setting. nMethods: Hearts of 18 piglets were examined in a homologous blood-perfused, working heart model to get baseline measurements. After hypothermic cardioplegic arrest and storage on ice for 60 minutes, the hearts received either milrinone or served as controls. All hearts were examined for 45 minutes in the working heart model. Hemodynamic parameter changes, h-FABP levels and myocardial oxygen consumption were assessed. nResults: Significant difference between the groups was observed in cardiac output (MIL +14% vs. CON -33%; p<0.05), coronary sinus blood flow (MIL +84% vs. CON +17%; p<0.05) and relaxation (MIL +5% vs. CON -22%; p<0.01). In addition, significantly higher h-FABP (heart fatty acid binding proteine) levels after cold ischemia were measured in CON group (CON: 18.75 ng/ml; MIL 6.29 ng/ml; p<0.01). nConclusions: Milrinone has a positive effect on cardiac function after cardioplegic cardiac arrest with following cold-ischemia period in an isolated piglet heart model. Its use in a heart transplantation setting induces an improved hemodynamic performance and a better preservation from reperfusion injury.

Concomitant mitral valve replacement and re-re-repair of severe pectus deformity correction in a patient with Marfan syndrome.

CLINICAL SUMMARY The patient underwent a modified Nuss procedure at the age of 11 years. The deformity recurred and osteomyelitis had developed postoperatively. A second reoperation aggravated the deformity. Owing to a tolerable clinical state, further surgical therapy was not performed. The patient had a long history of paroxysmal cardiac arrhythmias diagnosed in the 1980s. The diagnosis of mitral valve insufficiency and mild aortic root ectasia was also made and followed up regularly. After years of unsuccessful drug therapies, cardioversions, and catheter ablations, the mitral valve insufficiency had worsened owing to ruptured chordae tendineae and surgical therapy was indicated. Inasmuch as the patient had an extreme type of chest deformity, correction of the cardiac defect without addressing the pectus excavatum did not seem promising (Figure 1, A). We thus decided to replace the mitral valve and to correct the deformity by median sternotomy. We started by preparing the pectoral muscles, separating them from the underlying ribs. The sternum was divided with an oscillating saw. Inasmuch as the deformity made it impossible for us to raise the parted bone, we had to cut ribs 4 to 8 bilaterally in the midclavicular portion. We introduced a sternal retractor with 2 elevating plates usually used for the preparation of the internal thoracic artery (Schollhorn thoracic retractors, IMA Elevating Plate; Karl Storz GmbH & Co, Tuttlingen, Germany) (Figure 2). The heart–lung machine was connected via an arterial cannulation of the ascending aorta and a separate cannula in the superior and inferior venae