Expanded polytetrafluoroethylene membranes to wrap surfaces of circulatory support devices in patients undergoing bridge to heart transplantation.

OBJECTIVE:Because of a lack of donor hearts, an increasing number of patients with heart failure must now undergo bridge to cardiac transplantation with a mechanical circulatory support device. Moreover, support periods have become longer. As a result, pericardial adhesions may develop while the support device is implanted, increasing the risk of injury at resternotomy and bleeding after transplantation. Use of expanded polytetrafluoroethylene (ePTFE) pericardial substitutes (membranes) may prevent such adhesions. PATIENTS AND METHODS:From January 1997 to December 1999, ePTFE membranes were used in 23 patients to wrap portions of an implanted left ventricular assist device (LVAD) or total artificial heart (TAH). Any complications during mechanical support or at cardiac transplantation were recorded. Six ePTFE membranes removed at transplantation were studied histologically. RESULTS AND CONCLUSIONS:At resternotomy for transplantation, the plane of dissection between tissues, ePTFE membranes, and surfaces of the mechanical support device were easily discerned. No adhesions were observed between tissues and membranes. There were no injuries during resternotomy and no patient had to undergo reoperation because of bleeding. One patient given a TAH had an infection during circulatory support that was controlled by antibiotic therapy. In another patient, clots developed between the device and an ePTFE membrane; these were removed successfully. Histologic studies of removed ePTFE membranes showed no infiltration of the membranes interstices by collagen or cellular components. Use of ePTFE membranes in patients undergoing bridge to transplantation with either an LVAD or a TAH limited adhesions between tissues and device surfaces without increasing the risk of infection.

Leprince P ，Rahmati M ，Bonnet N ，Bors V ，Rama A ，Léger P ，Gandjbakhch I ，Pavie A ... -  《EUROPEAN JOURNAL OF CARDIO-THORACIC SURGERY》

Outcomes of expanded polytetrafluoroethylene pericardial membrane implantation in left ventricular assist device explantation and heart transplantation.

Redo sternotomy and explantation of left ventricular assist devices (LVAD) for heart transplantation (HT) involve prolonged dissection, potential injury to mediastinal structures and/or bleeding. Our study compared a complete expanded polytetrafluoroethylene (ePTFE) wrap versus minimal or no ePTFE during LVAD implantation, on outcomes of subsequent HT. Between July 2005 and July 2018, 84 patients underwent a LVAD implant and later underwent HT. Thirty patients received a complete ePTFE wrap during LVAD implantation (Group 1), and 54 patients received either a sheet of ePTFE placed in the anterior mediastinum or no ePTFE (Group 2). Baseline characteristics were similar between Groups 1 and 2. Surgeons reported subjective improvements in speed, predictability, and safety of dissection with complete ePTFE compared with minimal or no ePTFE. Time from incision to initiation of cardiopulmonary bypass (CPB) were similar between groups (97 ± 38 vs. 89 ± 29 min, p = .3). Injury to mediastinal structures during the dissection was similar between groups (10% vs. 11%, p > .9). While surgeons reported less intraoperative bleeding in Group 1 (43% vs. 61%), this trend did not reach significance (p = .1). In-hospital mortality, intensive care unit length of stay and hospital length of stay were similar between both groups. In patients undergoing LVAD explant-HT, there was a trend toward reduced surgeon reported intraoperative bleeding with ePTFE placement. Despite qualitatively reported greater ease and speed of mediastinal dissection with ePTFE membrane placement, time to initiation of CPB did not differ, likely because surgeons remained cautious, allowing extra time for unanticipated difficulties.

An KR ，Christakis N ，Jegatheeswaran A ，Cusimano RJ ，Rao V ，Badiwala M ，Yau TM ... -  《-》

Comparison of total artificial heart and biventricular assist device support as bridge-to-transplantation.

The use of left ventricular assist devices (LVAD) has increased significantly in the last decade. However, right heart dysfunction remains a problem despite the improved outcomes with continuous-flow LVADs. Surgical options for bridge to transplantation (BTT) in patients with biventricular failure are total artificial heart (TAH) or biventricular support (BiVAD). This study examines the differences in pre- and post-transplantation outcomes and survival in patients with TAH or BiVAD support as BTT. The United Network of Organ Sharing database was retrospectively queried from January 2005 to December 2014 to identify adult patients undergoing heart transplantation (n = 17,022). Patients supported with either TAH (n = 212) or BiVAD (n = 366) at the time of transplantation were evaluated. Pre- and post-transplantation Kaplan-Meier survival curves were examined. Cox regression model was used to study the hazard ratios of the association between TAH versus BiVAD support and post-transplant survival. The median age of the study groups was 49.8 ± 12.9 (TAH) and 47.2 ± 13.9 (BiVAD) years (range 18-74 years). There were more men, 87% versus 74%, in the TAH group (p < 0.0001) with greater body mass index, 27.3 ± 5.2 versus 25.6 ± 4.7 (p < 0.0001), compared to those with BiVADs. Creatinine was higher, 1.7 + 1.2 versus 1.3 + 0.8 mg/dL (p < 0.0001), in the TAH group before transplant. The 30-day, one-, and three-year post-transplantation survival was 88%, 78%, and 67%, respectively, for patients with TAH support versus 93%, 83%, and 73% (p = 0.06) for patients with BiVAD support. Cox regression model shows pre-transplant creatinine (HR = 1.21, p = 0.008) is associated with a lower post-transplant survival. TAH is not associated with a worse post-transplant survival (p = 0.1). There was no difference in wait-list survival in patients supported with TAH or BiVAD (p = 0.8). Although there has been a recent increase in the use of the TAH as BTT, BiVAD support remains a viable option with similar post-transplant survival.

Cheng A ，Trivedi JR ，Van Berkel VH ，Massey HT ，Slaughter MS ... -  《-》

Left ventricular assist devices as bridge to heart transplantation: The Niguarda Experience.

Congestive heart failure is the leading cause of death in Western countries. Heart transplantation currently is the only accepted therapy for patients with end-stage heart failure, but the supply of donor hearts is inadequate, and different mechanical circulatory support systems have been investigated as bridges to heart transplant. Since April 1992, 53 patients (47 men, 6 women, aged 12 to 61 years) received left ventricle mechanical circulatory support as bridge to heart transplant. The two principal devices used were: the Novacor LVAS in 31 patients and the DeBakey VAD in 11 patients. All patients survived the operation. Mean duration of LVAD support was 2.8 +/- 5.6 months. Thirty-seven patients (71.1%) underwent heart transplantation. Twelve major bleeding episodes occurred in nine patients (16.9%). Globally, major and minor neurologic events occurred in 13 patients (24.5%). Ten patients (19.9%) assisted with the Novacor Wearable LVAS device were discharged at home while waiting for heart transplant (HTx). The mean follow-up of the 34 discharged transplanted patients was 45.3 +/- 37 months. Actuarial survival of transplanted patients while on LVAD was 91.0 +/- 4.9% and 83.4 +/- 8.5% at 1 and 5 years, respectively. No differences in post-transplant long-term survival and rejection and allograft vasculopathy occurred between patients transplanted with or without LVAD implanted. LVAD therapy proved to be effective in bridging patients with end-stage heart failure to HTx. While on LVAD support, patients assisted with implantable wearable devices could be discharged at home, ameliorating their quality of life. The excellent survival rate after HTx is concomitant with a low incidence of rejection and cardiac allograft vasculopathy.

Vitali E ，Lanfranconi M ，Bruschi G ，Russo C ，Colombo T ，Ribera E ... -  《JOURNAL OF CARDIAC SURGERY》

Gender differences in continuous-flow left ventricular assist device therapy as a bridge to transplantation: a risk-adjusted comparison using a propensity score-matching analysis.

The purpose of this study was to evaluate gender differences regarding outcome after continuous-flow left ventricular assist device (cfLVAD) implantation. The study was a retrospective review of prospectively collected data. Included were 24 consecutive female cfLVAD recipients and 24 male recipients (62.5% HeartMate II, 37.5% HeartWare) who received their devices between July 2007 and May 2013. Subjects were matched using propensity score analysis based on age, diagnosis, body surface area, preoperative mechanical circulatory support, heart failure severity score (INTERMACS class), and comorbidities. Female patients were significantly sicker before operation. After propensity score matching, there were no statistically significant differences in demographics or clinical baseline characteristics between male and female LVAD recipients. Also, there was a trend towards a longer postoperative intensive care unit stay in the female group (median 9 days [interquartile range 5-17] versus 15 days [interquartile range 8-33]; P < 0.061) and higher postoperative bilirubin values (median 14 mmol/L [interquartile range 10-17] versus 21 mmol/L [interquartile range 13-30]). However, there were no significant differences between the two groups in terms of outcome (P < 0.569). The overall survival was comparable between the two groups (log rank P < 0.389). Half (50%) of female patients required inotropic support for more than 7 days compared with 21.7% in the male group (P < 0.048). Half (50%) of female recipients required short-term postoperative right ventricular assist device implantation compared with 16.7% in the male group (P < 0.014). In conclusion, cfLVAD implantation as a bridge to transplantation is associated with longer duration of inotropic support and higher requirement for postoperative mechanical right ventricular support in women with similar survival rates. Further studies are required to identify additional demographic and clinical factors that modulate outcomes and will enhance the ability to risk-stratify cfLVAD recipients.

Weymann A ，Patil NP ，Sabashnikov A ，Mohite PN ，García Sáez D ，Amrani M ，Bahrami T ，De Robertis F ，Wahlers T ，Banner NR ，Popov AF ，Simon AR ... -  《-》