Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

An experimental approach to analyze aerosol and splatter formations due to a dental procedure

Throughout 2020 and beyond, the entire world has observed a continuous increase in the infectious spread of the novel coronavirus (SARS-CoV-2) otherwise known as COVID-19. The high transmission of this airborne virus has raised countless concerns regarding safety measures employed in the working conditions for medical professionals. Specifically, those who perform treatment procedures on patients which intrinsically create mists of fine airborne droplets, i.e., perfect vectors for this and other viruses to spread. The present study focuses on understanding the splatter produced due to a common dentistry technique to remove plaque buildup on teeth. This technique uses a high-speed dentistry instrument, e.g., a Cavitron ultrasonic scaler, to scrape along the surface of a patient's teeth. This detailed understanding of the velocity and the trajectory of the droplets generated by the splatter will aid in the development of hygiene mechanisms to guarantee the safety of those performing these procedures and people in clinics or hospitals. Optical flow tracking velocimetry (OFTV) method was employed to obtain droplet velocity and trajectory in a two-dimensional plane. Multiple data collection planes were taken in different orientations around a model of adult mandibular teeth. This technique provided pseudo-three-dimensional velocity information for the droplets within the splatter developed from this high-speed dental instrument. These results indicated that within the three-dimensional splatter produced there were high velocities (1-2 m/s) observed directly below the intersection point between the front teeth and the scaler. The splatter formed a cone-shape structure that propagated 10-15 mm away from the location of the scaler tip. From the droplet trajectories, it was observed that high velocity isolated droplets propagate away from the bulk of the splatter. It is these droplets which are concerning for health safety to those performing the medical procedures. Using a shadowgraphy technique, we further characterize the individual droplets' size and their individual velocity. We then compare these results to previously published distributions. The obtained data can be used as a first step to further examine flow and transport of droplets in clinics/dental offices.

Safety of emergency, elective and day case operating during the winter period at East Suffolk and North Essex NHS Foundation Trust: lessons from the outcomes of 4,254 surgical patients from the first COVID-19 wave

BACKGROUND

There is limited evidence on perioperative outcomes of surgical patients during the COVID-19 pandemic to inform continued operating into the winter period.

METHODS

We retrospectively analysed the rate of 30-day COVID-19 transmission and mortality of all surgical patients in the three hospitals in our trust in the East of England during the first lockdown in March 2020. All patients who underwent a swab were swabbed on or 24 hours prior to admission.

RESULTS

There were 4,254 patients and an overall 30-day mortality of 0.99%. The excess surgical mortality in our region was 0.29%. There were 39 patients who were COVID-19 positive within 30 days of admission, 12 of whom died. All 12 were emergency admissions with a length of stay longer than 24 hours. There were three deaths among those who underwent day case surgery, one of whom was COVID-19 negative, and the other two were not swabbed but not suspected to have COVID-19. There were two COVID-19 positive elective cases and none in day case elective or emergency surgery. There were no COVID-19 positive deaths in elective or day case surgery.

CONCLUSIONS

There was a low rate of COVID-19 transmission and mortality in elective and day case operations. Our data have allowed us to guide patients in the consent process and provided the evidence base to restart elective and day case operating with precautions and regular review. A number of regions will be similarly affected and should perform a review of their data for the winter period and beyond.

82 A Case of Recurrent Calcifying Aponeurotic Fibroma of the Hand: Managing a Rare Hand Tumour in an Evolving Healthcare Landscape

Introduction

Calcifying Aponeurotic Fibroma (CAF) is a rare benign tumour originating from the aponeuroses of tendons and their bony insertions. Our case illustrates the technical challenges and considerations of removing a large, recurrent CAF of the hand.

Case Report

A 15-year-old student presented to his GP with a one-year history of a progressively enlarging painless swelling on the dorsum of the middle phalanx of the left middle finger. Plain radiographs identified a calcified soft tissue swelling with no bony involvement. The lesion was excised by the local paediatric orthopaedic service and recurred rapidly. Histology confirmed the diagnosis. He was referred to our specialist hand surgery service and the lesion was excised with the overlying skin (which demonstrated histological but not clinical disease). At six months, there was no clinical evidence of recurrence.

Conclusions

CAF may present atypically, and a high index of suspicion is warranted with calcified soft tissue hand lesions. Excision with conservative margins, and we newly suggest, the overlying skin, is recommended to preserve hand function but minimise recurrence (very common). Hand surgery provision in the UK is changing with adoption of the hub and spoke model and hand tumours may be more appropriately managed at specialist centres.

Reflecting on success in trauma research: experiences from the SGCNS and SIR studies

The inclusion of British Service Personnel (SP) lacking capacity into research studies from the point of injury through to medium-term rehabilitation had not previously been undertaken until work to support operations in Afghanistan (2001-2014). The Surgeon General's Casualty Nutrition Study and the Steroids and Immunity from Injury through to Rehabilitation Study sought to address the nutrition, endocrine and immune responses in a military patient cohort. A fundamental part of research is to feedback to patients, their relatives and ward staff on data collection and outcomes, and how future research may be improved to better support both injured SP and trauma patients in the UK. This paper will provide an experiential view on the delivery, operations and infrastructure requirements that should be considered when developing military research at a role-3 facility, before, during and after a study.

1044 Adequate Sleep is Associated with Improved Diabetes Knowledge and HbA1c

Introduction

Although 55 % of the people with T2DM have low quality of sleep that may affect their physical and emotional wellbeing, and present challenges to the management of their condition, many Diabetes Self-Management Education Programs (DSME) that aim to improve knowledge of T2DM, don’t include information on healthy sleep. This study will examine the relationship between adequate sleep on improved T2DM knowledge and diabetes maintenance (HbA1c).

Methods

The Sleep Integrated with Diabetes Education (SLIDE) Trial tests whether including four brief healthy sleep hygiene sessions within an existing traditional Diabetes Self-Management Education Program improves healthy sleep, motivation for change, and biopsychosocial outcomes for 50 patients with DM who are under and uninsured. This study uses descriptive and ANOVAs to examine the relationship between adequate sleep and change in diabetes knowledge (Diabetes Knowledge Test) using self-report. EMR was used to link HbA1c and other biological measures.

Results

Fifty patients with T2DM (mean HbA1c = 8.79 ± 2.42) participating in a DSME Program at a southern urban community nonprofit hospital were randomly assigned to DSME classes or DSME classes + four 15-minute presentations (video and powerpoint) highlighting healthy sleep hygiene practices. The majority of these patients were obese (mean BMI=38.56±8.20). Only 11% reported normal sleep, with 41% reporting short sleep (<6 hours) and 7% long sleep (>8 hours). Patients who reported adequate sleep were more likely to improve diabetes knowledge (81% score vs. 68% score, p<.001) and HbA1c (1.1 vs. -.03, p<.001).

Conclusion

There is a relationship between adequate sleep and improving diabetes knowledge and maintenance for patients with T2DM. Future research could further explore this relationship and determine barriers and facilitators to adequate sleep and what role adequate sleep plays in improving T2DM knowledge and maintenance.

Support

Bon Sequor Foundation

Petrifilm™ Rapid S. aureus Count Plate Method for Rapid Enumeration of Staphylococcus aureus in Selected Foods: Collaborative Study

A rehydratable dry-film plating method for Staphylococcus aureusin foods, the 3M™ Petrifilm™ Rapid S. aureus Count Plate method, was compared with AOAC® Official MethodSM 975.55 (Staphylococcus aureus in Foods). Nine foods—instant nonfat dried milk, dry seasoned vegetable coating, frozen hash browns, frozen cooked chicken patty, frozen ground raw pork, shredded cheddar cheese, fresh green beans, pasta filled with beef and cheese, and egg custard—were analyzed for S. aureus by 13 collaborating laboratories. For each food tested, the collaborators received 8 blind test samples consisting of a control sample and 3 levels of inoculated test sample, each in duplicate. The mean log counts for the methods were comparable for pasta filled with beef and cheese; frozen hash browns; cooked chicken patty; egg custard; frozen ground raw pork; and instant nonfat dried milk. The repeatability and reproducibility variances of the Petrifilm Rapid S. aureus Count Plate method were similar to those of the standard method.

2418Th17 signature, autoimmunity and differentially expressed genes in cardiomyopathy and heart failure

Background

Cardiomyopathy may occur due to viral infections or drug induced heart damage. Cardiac myosin released from damaged heart has been shown to be a damage associated molecular pattern which binds to TLR2 or TLR8 and can act as an adjuvant to induce a strong autoimmune response against the heart. The result is autoimmunity against the heart which can lead to apoptosis, fibrosis and heart failure.

Purpose

Immune biomarkers of the early stages of heart failure are needed to identify individuals who develop progressive heart failure, do not recover their ejection fraction and may be candidates for immunotherapies.

Methods

Forty-one patients with myocarditis and heart failure <6 months after onset were followed for 12 months and compared to age matched controls. Peripheral blood mononuclear cells were analyzed by FACS analysis and serum analyzed by ELISA for autoantibodies and cytokines. Statistical analysis was determined by Mann Whitney test. Peripheral blood of 10 patients with dilated cardiomyopathy (DCM) vs 19 healthy controls were analyzed for gene expression by RNA sequencing and pathway analysis using Reactome.

Results

Autoantibodies against human cardiac myosin and the beta-adrenergic receptor were significantly elevated in our cohort and functionally acted on cardiomyocytes to activate protein kinase A. Concomitantly, a Th17+ immunophenotype was significantly elevated in blood as well as in cardiac biopsies. CD4+IL17+ T cells (p=0.0008) and Th17-promoting cytokines TGF beta (p<0.0001), IL-6 (p<0.0001), IL-23 (p=0.0001), GMCSF (p=0.0336) and GMCSF-secreting CD4+ T cells (p=0.0006) were significantly elevated in blood. A Th17 immunophenotype was significantly associated with heart failure primarily in males (p=0.029). Persistent heart failure (NYHA class III and IV) and non-recovery of left ventricular function were associated with significantly higher percentages of IL17A-producing T cells at baseline, 6 and 12 months after onset, and IL-17A (p=0.019) and elevated Th17-promoting cytokines IL-6 (p=0.0001) and TGF-beta (p=0.0076). Decreased T regulatory immunosuppressive cells were significantly (p=0.0006) decreased and correlated with elevated Th17 cytokines in heart failure. Overrepresentation analysis of differentially expressed genes (adj p<0.05) in blood of patients with DCM >1year were identified using Reactome which revealed significant (FDR = 1.52E-13) enrichment of neutrophil degranulation (48 genes).

Conclusion

Our study illustrates a strong Th17 signature in more severe heart failure early in disease with elevated anti-cardiac myosin autoantibodies in non-recovery of left ventricular function. We observed a strong correlation with Th17-related neutrophil degranulation pathways in later disease, which may be biomarkers of fibrosis progression and disease severity in patients with heart failure. Cardiomyopathy with a Th17 signature might be treated with preventive immunomodulatory therapies such as anti-IL17A.

Acknowledgement/Funding

National Heart Lung and Blood Institute, Bethesda, MD, USA

P945Abnormalities in ankle-brachial indices are independently associated with new-onset atrial fibrillation

Introduction

Lower extremity physiologic studies are an important non-invasive diagnostic tool in peripheral arterial disease (PAD). PAD and atrial fibrillation (AF) are associated with increased cardiovascular and all-cause mortality.

Purpose

To evaluate the association between PAD and new-onset AF and the risk of stroke.

Methods

We performed a study of all patients without AF undergoing ankle-brachial index (ABI) for any indication between January 1996 to June 2018. The ABI cut-off were as follows: abnormal ABI (0–0.99), normal ABI (1.00–1.39) and poor vessel compressibility (PC) (1.40+). Demographic, comorbidity, and outcome variables were extracted using the electronic medical record.

Results

Overall, 34,441 patients (mean age 66.8±14.3, 57.3% male, 88.2% white) were included in the study with a median follow-up of 7.2 years (interquartile range, 3.0–12.9 years). Multivariate Cox proportional hazard analysis showed increased risk of new-onset AF for male sex, older age, hypertension, coronary artery disease, cerebrovascular disease, chronic kidney disease stage III or greater, congestive heart failure, chronic obstructive pulmonary disease, and cancer (all p<0.0001). After adjustment, ABI results were significantly associated with new-onset AF, particularly poorly-compressible vessels (adjusted HR: 1.42 (1.30–1.55), p<0.0001) compared to abnormal ABI (adjusted HR: 1.12 (1.05–1.20), p=0.0012). Patients with atrial fibrillation were more likely to experience ischemic stroke (39.2% versus 16.1%, p<0.0001).

Conclusion

Abnormalities in ABI results, particularly poorly-compressible vessels, are independently associated with new-onset atrial fibrillation in a large ambulatory cohort. While the mechanism cannot be assessed, common inflammatory mechanisms and increased vascular stiffness may play an important role. Identification of AF in these at-risk patients may improve cardiovascular outcomes.

Experimental platform to facilitate novel back brace development for the improvement of spine stability

The spine or 'back' has many functions including supporting our body frame whilst facilitating movement, protecting the spinal cord and nerves and acting as a shock absorber. In certain instances, individuals may develop conditions that not only cause back pain but also may require additional support for the spine. Common movements such as twisting, standing and bending motions could exacerbate these conditions and intensify this pain. Back braces can be used in certain instances to constrain such motion as part of an individual's therapy and have existed as both medical and retail products for a number of decades. Arguably, back brace designs have lacked the innovation expected in this time. Existing designs are often found to be heavy, overly rigid, indiscrete and largely uncomfortable. In order to facilitate the development of new designs of back braces capable of being optimised to constrain particular motions for specific therapies, a numerical and experimental design strategy has been devised, tested and proven for the first time. The strategy makes use of an experimental test rig in conjunction with finite element analysis simulations to investigate and quantify the effects of back braces on flexion, extension, lateral bending and torsional motions as experienced by the human trunk. This paper describes this strategy and demonstrates its effectiveness through the proposal and comparison of two novel back brace designs.

Measurement of micro-scale soil deformation around roots using four-dimensional synchrotron tomography and image correlation

This study applied time lapse (four-dimensional) synchrotron X-ray computed tomography to observe micro-scale interactions between plant roots and soil. Functionally contrasting maize root tips were repeatedly imaged during ingress into soil columns of varying water content and compaction. This yielded sequences of three-dimensional densiometric data, representing time-resolved geometric soil and root configurations at the micronmetre scale. These data were used as inputs for two full-field kinematic quantification methods, which enabled the analysis of three-dimensional soil deformation around elongating roots. Discrete object tracking was used to track rigid mineral grains, while continuum digital volume correlation was used to track grey-level patterns within local sub-volumes. These techniques both allowed full-field soil displacements to be quantified at an intra-rhizosphere spatial sampling scale of less than 300 µm. Significant differences in deformation mechanisms were identified around different phenotypes under different soil conditions. A uniquely strong contrast was observed between intact and de-capped roots grown in dry, compacted soil. This provides evidence that functional traits of the root cap significantly reduce the amount of soil disturbance per unit of root elongation, with this effect being particularly significant in drier soil.

Weight loss interventions for adults with overweight/obesity and chronic musculoskeletal pain: a mixed methods systematic review

Worldwide prevalence of adult overweight and obesity is a growing public health issue. Adults with overweight/obesity often have chronic musculoskeletal pain. Using a mixed-methods review, we aimed to quantify the effectiveness and explore the appropriateness of weight loss interventions for this population. Electronic databases were searched for studies published between 01/01/90 and 01/07/16. The review included 14 randomized controlled trials that reported weight and pain outcomes and three qualitative studies that explored perceptions of adults with co-existing overweight/obesity and chronic musculoskeletal pain. The random-effects pooled mean weight loss was 4.9 kg (95%CI:2.9,6.8) greater for intervention vs control. The pooled mean reduction in pain was 7.3/100 units (95%CI:4.1,10.5) greater for intervention vs control. Study heterogeneity was substantial for weight loss (I²  = 95%, tau = ±3.5 kg) and pain change (I²  = 67%, tau = ±4.1%). Meta-regression slopes for the predictors of study quality, mean age and baseline mean weight on mean study weight reduction were shallow and not statistically significant (P > 0.05). The meta-regression slope between mean pain reduction and mean weight lost was shallow, and not statistically significant, -0.09 kg per unit pain score change (95%CI:-0.21,0.40, P = 0.54). Meta-synthesis of qualitative findings resulted in two synthesized findings; the importance of healthcare professionals understanding the effects of pain on ability to control weight and developing management/education programmes that address comorbidity.

Eficacia reducida de derquantel y abamectina en ovinos y caprinos con Haemonchus sp resistentes a lactonas macrocíclicas

<p>Se presentan las observaciones efectuadas sobre la actividad de una combinación antihelmíntica conteniendo un nueva droga, el derquantel (spiroindoles) adicionada con abamectina (lactonas macrocíclicas) en ovinos y caprinos naturalmente parasitados por <em>Haemonchus sp</em>. En el conteo de huevos, la eficacia de la combinación mostró porcentajes de reducción variables y dependientes de los estadios parasitarios intervinientes al momento del tratamiento y al <em>status </em>previo de resistencia a las lactonas macrocíclicas. Se observó una eficacia alta (mayor al 99%) frente a la oviposición de estadios maduros de <em>Haemonchus sp </em>o cuando los antecedentes de las poblaciones parasitarias indicaban resistencia no marcada a las lactonas macrocíclicas. Por el contrario, eficacias inferiores (76 al 83%) se observaron cuando las poblaciones de este parásito mostraban resistencia severa a las lactonas macrocíclicas y los estadios inmaduros constituían la mayor parte de la población parasitaria al momento del tratamiento. Las combinaciones antihelmínticas tienen un interesante potencial de uso frente a poblaciones parasitarias de <em>Haemonchus sp </em>resistentes a los antihelmínticos, pero las presentes observaciones enfatizan la necesidad de evaluar a nivel de cada establecimiento la actividad de todos los antiparasitarios, sean estos formulados con viejas o nuevas drogas, si se pretende instaurar programas racionales para el control de estos nematodes</p>

New onset diabetes after kidney transplantation is associated with increased mortality-A retrospective cohort study

OBJECTIVE

Clinical outcomes in individuals with new onset diabetes after transplantation (NODAT) and the optimal treatment for this complication are poorly characterized. This study was intended to better define these issues.

METHODS

Patients who underwent kidney transplantation and did not have diabetes prior to transplantation were included in the study. Clinical outcomes were compared between those who developed NODAT and those who did not. In those who developed NODAT, oral therapy was compared with insulin based therapy.

RESULTS

A total of 266 kidney transplant recipients were included, of which 71 (27%) developed NODAT during the time of the follow-up. Using Cox multivariate analysis adjusted for age and gender, hazard ratio for overall mortality among patients with NODAT versus those without NODAT was 2.69 (95% CI 1.04-7.01). Among patients who developed NODAT, 29 patients (40%) were treated with an insulin-based regimen. At the end of follow-up, no difference was found in mean HbA1c, and therapy regimen was not associated with greater mortality.

CONCLUSIONS

New onset diabetes in kidney transplanted patients is associated with increased mortality compared with kidney transplanted patients without NODAT.

Plant exudates may stabilize or weaken soil depending on species, origin and time

We hypothesized that plant exudates could either gel or disperse soil depending on their chemical characteristics. Barley (Hordeum vulgare L. cv. Optic) and maize (Zea mays L. cv. Freya) root exudates were collected using an aerated hydroponic method and compared with chia (Salvia hispanica L.) seed exudate, a commonly used root exudate analogue. Sandy loam soil was passed through a 500-μm mesh and treated with each exudate at a concentration of 4.6 mg exudate g-1 dry soil. Two sets of soil samples were prepared. One set of treated soil samples was maintained at 4°C to suppress microbial processes. To characterize the effect of decomposition, the second set of samples was incubated at 16°C for 2 weeks at -30 kPa matric potential. Gas chromatography-mass spectrometry (GC-MS) analysis of the exudates showed that barley had the largest organic acid content and chia the largest content of sugars (polysaccharide-derived or free), and maize was in between barley and chia. Yield stress of amended soil samples was measured by an oscillatory strain sweep test with a cone plate rheometer. When microbial decomposition was suppressed at 4°C, yield stress increased 20-fold for chia seed exudate and twofold for maize root exudate compared with the control, whereas for barley root exudate decreased to half. The yield stress after 2 weeks of incubation compared with soil with suppressed microbial decomposition increased by 85% for barley root exudate, but for chia and maize it decreased by 87 and 54%, respectively. Barley root exudation might therefore disperse soil and this could facilitate nutrient release. The maize root and chia seed exudates gelled soil, which could create a more stable soil structure around roots or seeds.

HIGHLIGHTS

Rheological measurements quantified physical behaviour of plant exudates and effect on soil stabilization.Barley root exudates dispersed soil, which could release nutrients and carbon.Maize root and chia seed exudates had a stabilizing effect on soil.Physical engineering of soil in contact with plant roots depends on the nature and origin of exudates.

Image-guided genomics of phenotypically heterogeneous populations reveals vascular signalling during symbiotic collective cancer invasion

Phenotypic heterogeneity is widely observed in cancer cell populations. Here, to probe this heterogeneity, we developed an image-guided genomics technique termed spatiotemporal genomic and cellular analysis (SaGA) that allows for precise selection and amplification of living and rare cells. SaGA was used on collectively invading 3D cancer cell packs to create purified leader and follower cell lines. The leader cell cultures are phenotypically stable and highly invasive in contrast to follower cultures, which show phenotypic plasticity over time and minimally invade in a sheet-like pattern. Genomic and molecular interrogation reveals an atypical VEGF-based vasculogenesis signalling that facilitates recruitment of follower cells but not for leader cell motility itself, which instead utilizes focal adhesion kinase-fibronectin signalling. While leader cells provide an escape mechanism for followers, follower cells in turn provide leaders with increased growth and survival. These data support a symbiotic model of collective invasion where phenotypically distinct cell types cooperate to promote their escape.

The mechanisms linking phenotypic heterogeneity to collective cancer invasion are unclear. Here the authors develop an image-guided genomic technique to select and amplify leader and follower cells from in vitro invading cell packs and find a cooperative symbiotic relationship between these two cell populations.

Umbilical cord blood graft engineering: challenges and opportunities

We are entering a very exciting era in umbilical cord blood transplantation (UCBT), where many of the associated formidable challenges may become treatable by ex vivo graft manipulation and/or adoptive immunotherapy utilizing specific cellular products. We envisage the use of double UCBT rather than single UCBT for most patients; this allows for greater ability to treat larger patients as well as to manipulate the graft. Ex vivo expansion and/or fucosylation of one cord will achieve more rapid engraftment, minimize the period of neutropenia and also give certainty that the other cord will provide long-term engraftment/immune reconstitution. The non-expanded (and future dominant) cord could be chosen for characteristics such as better HLA matching to minimize GvHD, or larger cell counts to enable part of the unit to be utilized for the development of specific cellular therapies such as the production of virus-specific T-cells or chimeric-antigen receptor T-cells which are reviewed in this study.