A distractions capture tool for cardiac surgery and lung transplantation: impact on outcomes.

OBJECTIVES: Surgical distractions are associated with worse patient outcomes. Lung transplantation and cardiac surgery's multi-disciplinary nature, and their inherent complexities render them more vulnerable to distractions. We aim to use a novel distractions capture tool to evaluate the severity of distractions during cardiac surgery (CS) and lung transplantation (LTx) and assess its impact on post-operative complications. METHODS: A prospective 'blinded' study was undertaken by direct observation of distractions during CS and LTx. Events were identified using the Imperial College Error Capture tool (ICECAP). Number and severity of distractions were correlated with post-operative outcomes (ICU & hospital stay, bleeding and anastomotic complications). RESULTS: In LTx, we observed 2059 distractions within 287 h across 41 surgeries. In CS, we observed 1089 distractions within 192 h across 62 surgeries. Surgeons were consciously aware of 19.2% (LTx) and 21.3% (CS) of recorded events. Distractions consisted of procedure-independent pressures (61% LTx vs 56% CS), equipment problems (15% LTx vs 23%CS), communication (12% LTx vs 12% CS), technical problems or patient safety concerns (12% LTx vs 9% CS). In CS, 91% of procedure-independent pressures were non-operative distractions whilst LTx recorded 83%. Staff absences at a critical moment of surgery were recorded at 9% (LTx) and 7% (CS). The number and severity of distractions correlated with bleeding (CS p < 0.001, LTx p < 0.01), prolonged ICU stay (CS p = 0.002, LTx p = 0.002), hospital stay (CS p < 0.001) and anastomotic complications(LTx p < 0.03). CONCLUSIONS: ICECAP as a novel surgical distractions capture tool was effective & applicable to both elective cardiac and urgent transplant surgeries. Surgeons were unaware of a large number of distractions & interruptions. Distractions were associated with longer ICU stay and higher rate of bleeding.

Paediatric donation after circulatory determined death heart transplantation using donor normothermic regional perfusion and ex situ heart perfusion: A case report.

This is a report of a unique DCD paediatric heart transplant whereby normothermic regional perfusion was used to assess DCD heart function after death followed by ex situ heart perfusion of the graft during transportation from donor to recipient hospitals. The DCD donor was a 9-year-old boy weighing 84 kg. The recipient was 7-year-old boy with failing Fontan circulation and weighed 23 kg. It was an ABO-compatible heart transplantation. The DCD heart was reperfused and assessed using normothermic regional perfusion followed by portable ex situ heart perfusion during transportation. The orthotopic heart transplantation was successful with good graft function and no evidence of rejection on endomyocardial biopsy at 30 days post-transplant. At 1-year follow-up, excellent graft function is maintained, and he is attending school with a good quality of life. DCD heart transplantation in children is a promising solution to reducing paediatric waiting times. The case demonstrates the feasibility of using normothermic regional perfusion in the donor and ex situ heart perfusion during graft transportation. This combination allowed a functional assessment whilst minimizing warm ischaemia resulting in a successful outcome. More research and long-term follow-up are needed in order to benefit from the huge potential that paediatric DCD heart transplantation has to offer.

Profiling inflammation and tissue injury markers in perfusate and bronchoalveolar lavage fluid during human ex vivo lung perfusion.

Objectives: Availability of donor lungs suitable for transplant falls short of current demand and contributes to waiting list mortality. Ex vivo lung perfusion (EVLP) offers the opportunity to objectively assess and recondition organs unsuitable for immediate transplant. Identifying robust biomarkers that can stratify donor lungs during EVLP to use or non-use or for specific interventions could further improve its clinical impact. Methods: In this pilot study, 16 consecutive donor lungs unsuitable for immediate transplant were assessed by EVLP. Key inflammatory mediators and tissue injury markers were measured in serial perfusate samples collected hourly and in bronchoalveolar lavage fluid (BALF) collected before and after EVLP. Levels were compared between donor lungs that met criteria for transplant and those that did not. Results: Seven of the 16 donor lungs (44%) improved during EVLP and were transplanted with uniformly good outcomes. Tissue and vascular injury markers lactate dehydrogenase, HMGB-1 and Syndecan-1 were significantly lower in perfusate from transplanted lungs. A model combining IL-1ß and IL-8 concentrations in perfusate could predict final EVLP outcome after 2 h assessment. In addition, perfusate IL-1ß concentrations showed an inverse correlation to recipient oxygenation 24 h post-transplant. Conclusions: This study confirms the feasibility of using inflammation and tissue injury markers in perfusate and BALF to identify donor lungs most likely to improve for successful transplant during clinical EVLP. These results support examining this issue in a larger study.

Pregnancy in cardiac transplant recipients.

PURPOSE: Successful pregnancy following cardiac transplantation has been described, although outcome data from individual centers are relatively sparse. We investigated maternal and fetal outcomes including change in left ventricular (LV) function and calcineurin inhibitor (CNI) dose in women who became pregnant from our institution. METHODS: We identified every female patient <49 years at the time of transplant who survived >3 months post-surgery, between 1985 and 2014. Those who conceived had a review of their medical records and transplant charts. Those currently alive were interviewed. RESULTS: There were 22 pregnancies in 17 women with 20 live births (91%). Mean time from transplantation was 98±62.4 months. Rejection complicated one pregnancy, and LV function remained normal in all others. Hypertension complicated 3 (13.6%), preeclampsia 3 (13.6%), and cholestasis 1 (4.5%). Mean birthweight was 2447±608 grams at 34.1±3.6 weeks. Four women died following pregnancy. A significant increase in total daily dose of tacrolimus and cyclosporine A was required to maintain therapeutic levels through pregnancy (CyA, P<.001; and Tac, P=.001), with no deterioration in serum creatinine. CONCLUSIONS: We report a 91% live birth rate post-cardiac transplantation. Meticulous individualized care with frequent monitoring of CNI levels and LV function is necessary to optimize the maternal and fetal outcomes.

An Extended Role of Continuous Flow Device in Pediatric Mechanical Circulatory Support.

BACKGROUND: Mechanical circulatory support in the pediatric population is currently limited to pulsatile ventricular assist devices (VAD). In recent years, the use of durable, newer generation, continuous flow devices have increased substantially among adults with end-stage heart failure. We examined the extended role of this device in the pediatric population (aged less than 18 years). METHODS: Between 2010 and 2015, 12 patients (median age 7.1 years; range, 3.7 to 17.0; one third of patients were aged 5 years or less) received a HeartWare ventricular assist device (HVAD; HeartWare, Framingham, MA), 11 for cardiomyopathy and 1 for posttransplant rejection. Right VAD support (n = 5; 42%) was provided by a short-term device (Levitronix, Zurich, Switzerland). RESULTS: Overall, 1 patient died (day 638), 8 patients (67%) underwent transplantation, 1 patient (8.3%) recovered, and 2 patients (17%) remain on HVAD. The mean length of support was 150 days (range, 16 to 638). Four patients (33.3%) were discharged home (all left VAD). In the left VAD group (n = 7), 3 patients subsequently received transplants (days 185, 201, and 234, respectively), 1 recovered (day 149), 1 died (day 638), 1 remained on HVAD (day 198), and 1 needed conversion to biventricular assist device (BIVAD [day 73]). In the BIVAD group (n = 5), right VAD was weaned in 3 (60%), all subsequently received transplants, and 2 remained on BIVAD support until transplant (days 16 and 17, respectively). One BIVAD patient required conversion to central cannulation for longer-term support. Four BIVAD patients (80%) were in Interagency Registry for Mechanically Assisted Circulatory Support level 1 before VAD compared with 2 (29%) in the left VAD group (p = not significant). The actuarial survival rate was 100% at 1 year with no neurologic events. CONCLUSIONS: The third-generation, continuous flow device can provide durable support in the pediatric population. The selection strategy for patients who benefit most from the device continues to evolve. It is anticipated that a smaller design in the future will benefit an even wider pediatric population with heart failure.

Development of de novo aortic valve incompetence in patients with the continuous-flow HeartWare ventricular assist device.

BACKGROUND: In this study we investigated the development of aortic incompetence (AI) and change in aortic root and left ventricular dimensions after implantation of the continuous-flow HeartWare ventricular assist device (HVAD) in our adult patient cohort. METHODS: A retrospective analysis of serial echocardiograms was performed on patients implanted with an HVAD between July 2009 and July 2013. Data from echocardiograms performed before and at 1 and 2 years (±3 months) were analyzed. Patients with native aortic valves (AoVs) with no previous intervention and HVAD in situ for ≥6 months were included. RESULTS: A total of 73 HVADs in 71 patients with a mean duration of support of 624 ± 359 days were included in our study. One patient developed moderate AI at 1 year (1.9%). Mild or greater AI was more likely in those with a closed or intermittently opening AoV at 1 year (p = 0.005). Aortic annulus dimensions increased significantly at 1 and 2 years, regardless of extent of AI. At 2 years, in those with mild or worse AI, the sinuses of Valsalva were also larger (p = 0.002). Left ventricular end-diastolic dimension (LVEDD) was significantly reduced in those with no or trace AI at 1 and 2 years (p = 0.012 and p = 0.008, respectively), but remained unchanged in those with AI at both time-points. CONCLUSIONS: The development of more than mild AI is rare in HVAD patients at our center. When encountered, it is more common with a closed AoV. Dilation of the aortic annulus, and root dilation in those with mild or more AI, is seen with HVAD support over time.

Durable ventricular assist device support for failing systemic morphologic right ventricle: early results.

BACKGROUND: The systemic morphologic right ventricle (RV) in congenitally corrected transposition of the great arteries or after atrial switch for transposition of the great arteries is associated with late ventricular failure. Although the role of the left ventricular assist device (LVAD) in supporting the failing LV is established, the indications and outcomes of using LVAD in a systemic RV remain unclear. We assessed the role of a third-generation LVAD for systemic RV support. METHODS: Seven patients (mean age, 36 years) received the HeartWare (HeartWare International Inc, Framingham, MA) VAD for systemic RV failure (congenitally corrected transposition of the great arteries in 1 and after atrial switch in 6). Four patients (57%) had severe subpulmonic LV failure, and aggressive perioperative diuresis with or without hemofiltration was used to offload the subpulmonic LV. The indications of VAD were (1) bridge to transplant in 3 and (2) bridge to decision for a high transpulmonary gradient in 4. Transplantation outcome was compared with systemic RV failure without VAD bridge in 19 patients (years 1989 to 2013). RESULTS: Systemic RV support alone was achieved in all patients, with no early deaths (≤30 days). Overall, 6 (86%) returned home, 3 (44%) received a transplant, 2 (28%) died of noncardiac causes, and 2 (28%) continue on VAD support (median support, 232 days). Repeat catheterization (n = 4) showed an improved median transpulmonary gradient in 3 patients (median 18.5 mm Hg pre-VAD vs 8.0 mm Hg post-VAD). Two bridge-to-decision patients received transplants at 640 and 685 days. The stroke rate on VAD support was 43% (2 thromboembolic and 1 hemorrhagic; 3 with satisfactory recovery). De novo aortic regurgitation was 29% (n = 2; 1 valve replacement). All patients (n = 3) survived transplantation (vs 10.5% early mortality without VAD bridge; p = 1.00) and were well at follow-up (range, 53 to 700 days). CONCLUSIONS: The third-generation VAD provides durable support for systemic RV failure as a bridge to transplant and as a strategy to reduce pulmonary vascular resistance. Although concomitant subpulmonic LV failure is common, systemic RV support alone was achieved in all patients.

Four-year outcomes with third-generation centrifugal left ventricular assist devices in an era of restricted transplantation.

OBJECTIVES: Third-generation ventricular assist devices (VADs) are associated with improved outcomes, though in recent clinical trials bridge-to-transplant (BTT) rates are ∼30% at 6 months, so that transplantation can be used as a 'bail out' for serious complications. In the UK, there was a significant reduction in heart transplantation rates over the last decade, so that transplantation from VADs is much less frequent. The objective of this study was to determine outcomes and their predictors in this situation of low BTT rates, and as patients were exposed to long-term support, the incidence and outcomes of VAD thrombosis. METHODS: We analysed outcomes for 102 consecutive patients between 2009 and 2013 (mean age 47 ± 13; VentrAssist n = 6 and HeartWare n = 96). The median duration of support was 462 ± 426 days. RESULTS: Survival rates on the device were 75 and 66% at 1 and 2 years, respectively. Older age and more acute INTERMACS groups were significantly related to reduced survival within the first 90 days (P = 0.030 and 0.010, respectively). Poor preoperative right ventricular (RV) function had a negative effect on survival after 1 year (P = 0.009), though not earlier. VAD thrombosis (n = 24 HeartWare and n = 1 VentrAssist) occurred at 0.18 events per patient-year for HeartWare and 0.07 for VentrAssist devices at a median time of onset at 404 ± 281 days. There was no significant effect of VAD thrombosis on survival. Only 14 of 102 patients were transplanted at a median of 334 ± 347 days, and only 3 were transplanted within the first 6 months. CONCLUSIONS: Third-generation left ventricular assist device implants with a low rate of transplantation have similar survival to destination therapy, and are susceptible to long-term complications of VAD thrombosis and right heart failure.

The effect of ex vivo lung perfusion on microbial load in human donor lungs.

BACKGROUND: Ex vivo lung perfusion (EVLP) has emerged as a technique to potentially recondition unusable donor lungs for transplantation. Beneficial effects of EVLP on physiologic function have been reported, but little is known about the effect of normothermic perfusion on the infectious burden of the donor lung. In this study, we investigated the effect of EVLP on the microbial load of human donor lungs. METHODS: Lungs from 18 human donors considered unusable for transplantation underwent EVLP with a perfusate containing high-dose, empirical, broad-spectrum anti-microbial agents. Quantitative cultures of bacteria and fungi were performed on bronchoalveolar lavage fluid from the donor lung before and after 3 to 6 hours of perfusion. The identification of any organisms and changes in number of colony forming units before and after EVLP were assessed and anti-microbial susceptibilities identified. RESULTS: Thirteen out of 18 lungs had positive cultures, with bacterial loads significantly decreasing after EVLP. Yeast loads increased when no anti-fungal treatment was given, but were reduced when prophylactic anti-fungal treatment was added to the circuit. Six lungs were ultimately transplanted into patients, all of whom survived to hospital discharge. There was 1 death at 11 months. CONCLUSIONS: Our study shows that EVLP with high-dose, empirical anti-microbial agents in the perfusate is associated with an effective reduction in the microbial burden of the donor lung, a benefit that has not previously been demonstrated.

Management issues during HeartWare left ventricular assist device implantation and the role of transesophageal echocardiography.

Left ventricular assist devices (LVAD) are increasingly used for mechanical circulatory support of patients with severe heart failure, primarily as a bridge to heart transplantation. Transesophageal echocardiography (TEE) plays a major role in the clinical decision making during insertion of the devices and in the post-operative management of these patients. The detection of structural and device-related mechanical abnormalities is critical for optimal functioning of assist device. In this review article, we describe the usefulness of TEE for optimal perioperative management of patients presenting for HeartWare LVAD insertion.

Vascular anastomotic complications in lung transplantation: a single institution's experience.

OBJECTIVES: Lung transplant recipients were reviewed to compare our early and current experience of vascular complications. Since 1995, we have had a policy of early identification and intervention. METHODS: We undertook a retrospective review of all adult lung transplants performed at our centre. Patients with pulmonary vascular complications before and after 1995 were identified and reviewed to determine changes in management and outcome. RESULTS: We identified a total of 13 patients with either pulmonary artery or venous obstruction out of a total of 720 adult lung transplants (1.8%). There were 9 females and 4 males with an age range of 25-64 years. Complications were more common in patients with fibrotic lung disease and involved 15 vascular anastomoses, most commonly the pulmonary arterial anastomosis. Prior to 1995, 5 cases were identified, all postoperatively. In this group, the mean time for identification of the complication was 9.4 (range 4-14) days. Only 1 patient survived to discharge. After 1995, vascular complications were identified intraoperatively in 4 cases and corrected immediately. Four cases were identified postoperatively (at <1-17 days) by a computed tomography pulmonary angiogram. Three were treated surgically within 24 h of diagnosis (using cardiopulmonary bypass with cold preservation). One patient was managed conservatively. Among patients identified after 1995, 5 survived to discharge. CONCLUSIONS: Though rare, pulmonary vascular complications after lung transplantation carry high mortality. In our opinion, early identification and intervention improves outcome. Intraoperative assessment by pressure gradient measurement and transoesophageal echocardiography is recommended. Despite this, mortality remains high and prevention is better than cure.

An alternative approach to explantation and exchange of the HeartWare left ventricular assist device.

OBJECTIVES: Left ventricular assist device (LVAD) explantation and exchange is a relatively infrequent but potentially complex procedure. Patients requiring such procedures have multisystem suboptimal physiological reserve due to end-stage heart failure and are prone to complications. Less-invasive procedures are believed to facilitate postoperative recovery and early mobilization. We describe an alternative approach to explantation and exchange of the HeartWare LVAD through left thoracotomy. METHODS: Six patients (M = 4, F = 2, mean age = 49.16 years) underwent device explant/exchange or initial implant (explant = 2, exchange = 3, initial implant = 1) through left thoracotomy utilizing cardiopulmonary bypass and induced ventricular fibrillation (VF). The mean bypass time and mean VF arrest time were 82 and 3 min, respectively. A new outflow graft was anastomosed to the previous outflow graft in 3 cases of device exchange and to the descending aorta in 1 case of initial implant. RESULTS: One patient died in the intensive care unit due to unrelated causes (gram-negative sepsis) after device exchange. All others were discharged alive and currently remain on follow-up. The mean length of hospital stay was 40.66 days. CONCLUSIONS: On-pump approach through single thoracotomy incision is safe and equally suitable for device explant, exchange and initial implant. However, structural heart defects requiring surgical correction and the requirement of simultaneous right ventricular assist device are the limitations of this approach.

Comparison of single lung transplant with and without the use of cardiopulmonary bypass.

OBJECTIVES: Many centres avoid using cardiopulmonary bypass (CPB) for lung transplant due to concerns over aggravated lung reperfusion injury and excessive blood loss. We reviewed our 23-years' experience of single lung transplantation. METHODS: A retrospective review of single lung transplants at our institution (1987-2010), examining differences in allograft function and postoperative complications between CPB and non-bypass (non-CPB) cases. RESULTS: Two hundred and fifty-nine single lung transplants were undertaken. Fifty-three (20.5%) with CPB. There was no difference demographically between the two groups. No difference existed in preoperative PO(2)/FiO(2). At 1 and 24 h, the postoperative PO(2)/FiO(2) ratio was no different (mean 2.95 and 3.24 in non-CPB cases; 3.53 and 3.75 in CPB patients, P = 0.18 and P = 0.34, respectively). Extubation time was not influenced by the use of CPB. Postoperative blood loss was greater in the CPB group. The usage of fresh frozen plasma and platelets was similar (P = 0.64 and 0.41, respectively). More blood was transfused during postoperative care of CPB patients (P = 0.02). CONCLUSIONS: Fears of poor postoperative lung function after CPB appear unfounded. We could detect no difference in function or extubation time. Although the use of CPB increases postoperative bleeding and the need for transfusion, it may be used safely to facilitate lung transplantation.

Invasive biopsy is effective and useful after lung transplant.

BACKGROUND: Transbronchial biopsy (TBB) is widely used after lung transplant but may not be diagnostic. Our group has used invasive approaches, open lung biopsy (OLB) or video-assisted thoracoscopy (VAT), to establish a definitive diagnosis in unexplained clinical deterioration. We sought to demonstrate the risks and benefits of this approach. METHODS: A retrospective review was made of the case notes of the patients undergoing OLB or VAT during a 12-year period from August 1996. RESULTS: During a 12-year period in 442 recipients, there were 51 invasive biopsies in 45 patients (6 had 2 procedures), of which 41 (80%) were OLB and 10 (20%) were VAT. Time of biopsy ranged from 7 days to 11 years after transplant. Thirty-seven (73%) took place in the first year, including 12 (24%) within the first 30 days. Nine patients died within 30 days of biopsy; 7 of them were already ventilated. Overall, biopsy provided a new unsuspected diagnosis in 37% of patients and confirmed the diagnostic suspicion in 47%. In only 16% of patients did it fail to provide a result that was clinically useful. The results of 29 (57%) biopsies led to a change in treatment. Sixty-three percent of new diagnoses and 71% where clinical suspicion was confirmed resulted in a treatment change. In all but 2 cases, a change was made to medication. CONCLUSIONS: In this large series of invasive biopsies, there was a high rate of useful results, with a frequent change in treatment. Invasive biopsies are a safe intervention in ambulatory patients.