How to counteract the lack of donor tissue in cardiac surgery? Initial experiences with a newly established homograft procurement program

Homograft heart valves may have significant advantages and are preferred for the repair of congenital valve malformations, especially in young women of childbearing age, athletes and in patients with active endocarditis. A growing problem, however, is the mismatch between tissue donation and the increasing demand. The aim of this paper is to describe the initiation process of a homograft procurement program to attenuate the shortage of organs. A comprehensive description of the infrastructure and procedural steps required to initiate a cardiac and vascular tissue donation program combined with a prospective follow-up of all homografts explanted at our institution. Between January 2020 and May 2022, 28 hearts and 12 pulmonary bifurcations were harvested at our institution and delivered to the European homograft bank. Twenty-seven valves (19 pulmonary valves, 8 aortic valves) were processed and allocated for implantation. The reasons for discarding a graft were either contamination (n = 14), or morphology (n = 13) or leaflet damage (n = 2). Five homografts (3 PV, 2 AV) have been cryopreserved and stored while awaiting allocation. One pulmonary homograft with a leaflet cut was retrieved by bicuspidization technique and awaits allocation, as a highly requested small diameter graft. The implementation of a tissue donation program in cooperation with a homograft bank can be achieved with reasonable additional efforts at a transplant center with an in-house cardiac surgery department. Challenging situations with a potential risk of tissue injury during procurement include re-operation, harvesting by a non-specialist surgeon and prior central cannulation for mechanical circulatory support

Paediatric aortic valve replacement using decellularized allografts

OBJECTIVES: Options for paediatric aortic valve replacement (AVR) are limited if valve repair is not feasible. Results of paediatric Ross procedures are inferior to adult Ross results, and mechanical AVR imposes constant anticoagulation with the inherent risks.METHODS: The study design was a prospective, multicentre follow-up of all paediatric patients receiving decellularized aortic homografts (DAHs) for AVR in 8 European centres.RESULTS: A total of 106 children (77 boys) were operated (mean age 10.1 +/- 4.8 years, DAH diameter 20.5 +/- 3.8 mm). A total of 60 (57%) had undergone previous surgical interventions: 34 with 1, 15 with 2 and 11 with >3. There was one early death in a 12-year-old girl, who underwent her fourth aortic valve operation, due to intracerebral haemorrhage on extracorporeal membrane oxygenation after coronary reimplantation problems following 3-sinus reconstruction 1 year earlier. One 2-year-old patient died due to sepsis 2 months postoperatively with no evidence for endocarditis. In addition, a single pacemaker implantation was necessary and a 2.5-year-old girl underwent successful HTx due to chronic myocardial failure despite an intact DAH. After a mean follow-up of 3.30 +/- 2.45 years, primary efficacy end points mean peak gradient (18.1 +/- 20.9 mmHg) and regurgitation (mean 0.61 +/- 0.63, grade 0-3) were very good. Freedom from death/explantation/endocarditis/bleeding/stroke at 5 years was 97.8 +/- 1.6/85.0 +/- 7.4/100/100/100% respectively. Calculated expected adverse events were lower for DAH compared to cryopreserved homograft patients (mean age 8.9 years), lower than in Ross patients (9.4 years) and in the same range as mechanical AVR (12.8 years).CONCLUSIONS: Even though the overall number of paediatric DAH patients and the follow-up time span are still limited, our data suggest that DAHs may present a promising additional option for paediatric AVR.Thoracic Surger

Paediatric aortic valve replacement using decellularized allografts: a multicentre update following 143 implantations and five-year mean follow-up

OBJECTIVES: Decellularized aortic homografts (DAH) were introduced in 2008 as a further option for paediatric aortic valve replacement (AVR). METHODS: Prospective, multicentre follow-up of all paediatric patients receiving DAH for AVR in 8 European centres. RESULTS: A total of 143 DAH were implanted between February 2008 and February 2023 in 137 children (106 male, 74%) with a median age of 10.8 years (interquartile range 6.6–14.6). Eighty-four (59%) had undergone previous cardiac operations and 24 (17%) had undergone previous AVR. The median implanted DAH diameter was 21 mm (interquartile range 19–23). The median operation duration was 348 min (227–439) with a median cardiopulmonary bypass time of 212 min (171–257) and a median cross-clamp time of 135 min (113– 164). After a median follow-up of 5.3 years (3.3–7.2, max. 15.2 years), the primary efficacy end-points peak gradient (median 14 mmHg, 9–28) and regurgitation (median 0.5, interquartile range 0–1, grade 0–3) showed good results but an increase over time. Freedom from death/explantation/endocarditis/bleeding/thromboembolism at 5 years were 97.8 ± 1.2/88.7 ± 3.3/99.1 ± 0.9/100 and 99.2 ± 0.8%, respectively. Freedom from death/explantation/endocarditis/bleeding/thromboembolism at 10 years were 96.3 ± 1.9/67.1 ± 8.0/93.6 ± 3.9/ 98.6 ± 1.4 and 86.9 ± 11.6%, respectively. In total, 21 DAH were explanted. Seven were replaced by a mechanical AVR, 1 Ross operation was performed and a re-do DAH was implanted in 13 patients with no redo mortality. The calculated expected adverse events were lower for DAH compared to cryopreserved homograft patients (mean age 8.4 years), and in the same range as for Ross patients (9.2 years) and mechanical AVR (13.0 years). CONCLUSIONS: This large-scale prospective analysis demonstrates excellent mid-term survival using DAH with adverse event rates comparable to paediatric Ross procedures.Thoracic Surger

Five-year results from a prospective, single-arm European trial on decellularized allografts for aortic valve replacement-the ARISE Study and ARISE Registry Data

OBJECTIVES: Decellularized aortic homografts (DAH) were introduced as a new option for aortic valve replacement for young patients.METHODS: A prospective, EU-funded, single-arm, multicentre study in 8 centres evaluating non-cryopreserved DAH for aortic valve replacement.RESULTS: A total of 144 patients (99 male) were prospectively enrolled in the ARISE Trial between October 2015 and October 2018 with a median age of 30.4 years [interquartile range (IQR) 15.9–55.1]; 45% had undergone previous cardiac operations, with 19% having 2 or more previous procedures. The mean implanted DAH diameter was 22.6mm (standard deviation 2.4). The median operation duration was 312min (IQR 234–417), the median cardiopulmonary bypass time was 154min (IQR 118–212) and the median cross-clamp time 121min (IQR 93–150). No postoperative bypass grafting or renal replacement therapy were required. Two early deaths occurred, 1 due to a LCA thrombus on day 3 and 1 due ventricular arrhythmia 5h postoperation. There were 3 late deaths, 1 death due to endocarditis 4months postoperatively and 2 unrelated deaths after 5 and 7years due to cancer and Morbus Wegener resulting in a total mortality of 3.47%. After a median follow-up of 5.9years [IQR 5.1–6.4, mean 5.5 years. (standard deviation 1.3) max. 7.6 years], the primary efficacy end-points peak gradient with median 11.0mmHg (IQR 7.8–17.6) and regurgitation of median 0.5 (IQR 0–0.5) of grade 0–3 were excellent. At 5years, freedom from death/reoperation/endocarditis/bleeding/thromboembolism were 97.9%/93.5%/96.4%/99.2%/99.3%, respectively.CONCLUSIONS: The 5-year results of the prospective multicentre ARISE trial continue to show DAH to be safe for aortic valve replacement with excellent haemodynamics.Thoracic Surger

Impact of postoperative necrotizing enterocolitis after neonatal cardiac surgery on neurodevelopmental outcome at 1 year of age

ObjectivesWe analyzed the impact of postoperative necrotizing enterocolitis (NEC) after cardiac surgery in neonatal age on neurodevelopmental (ND) outcome at 1 year of age.MethodsUsing data from the Swiss Neurodevelopmental Outcome Registry for Children with Congenital Heart Disease (ORCHID), we analyzed perioperative variables including postoperative NEC (Bell's stage ≥2) and 1-year ND outcome (Bayley III).ResultsThe included patients (n = 101) had congenital heart disease (CHD), categorized as follows: 77 underwent biventricular repair for CHD with two functional chambers, 22 underwent staged palliation until the Fontan procedure for CHD with single ventricle physiology (n = 22), or 4 underwent single ventricle palliation or biventricular repair for borderline CHD (n = 4). Neonatal cardiopulmonary bypass (CBP) surgery was performed at a median age (IQR) of 8 (6) days. NEC occurred in 16 patients. Intensive care unit (ICU) length of stay (LOS) and the total duration of the hospitalization were longer in children with NEC than those in others (14 with vs. 8 days without NEC, p < 0.05; 49 with vs. 32 days without NEC, p < 0.05). The Bayley III scores of the analyzed patients determined at an age of 11.5 ± 1.5 months showed cognitive (CCS) (102.2 ± 15.0) and language scores (LCS) (93.8 ± 13.1) in the normal range and motor composite scores (MCS) (88.7 ± 15.9) in the low-normal range. After adjusting for socioeconomic status and CHD type, patients with NEC had lower CCS scores [β = −11.2 (SE 5.6), p = 0.049]. Using a cumulative risk score including NEC, we found a higher risk score to be associated with both lower CCS [β = −2.8 (SE 1.3), p = 0.030] and lower MCS [β = −3.20 (SE 1.3), p = 0.016].ConclusionsPostoperative NEC is associated with longer ICU and hospital LOS and contributes together with other complications to impaired ND outcome at 1 year of age. In the future, national and international patient registries may provide the opportunity to analyze large cohorts and better identify the impact of modifiable perioperative risk factors on ND outcome. Clinical Trial RegistrationClinicalTrials.gov identifier: NCT05996211