Sternal Bone Marrow Harvesting and Culturing Techniques from Patients Undergoing Cardiac Surgery

Background: Mesenchymal stromal cells (MSCs) are the most prominent cell type used in clinical regenerative medicine and stem cell research. MSCs are commonly harvested from bone marrow that has been aspirated from patients’ iliac crest. However, the ethical challenges of finding consenting patients and obtaining fresh autologous cells via invasive extraction methods remain to be barriers to MSC research. Methods: Techniques of harvesting sternal bone marrow, isolating and culturing MSCs, MSC surface phenotyping, and MSC differentiation are described. Samples from 50 patients undergoing a sternotomy were collected, and the time taken to reach 80% confluency and cell count at the second splitting of MSC were measured. Results: MSC isolated from the sternal bone marrow of patients undergoing cardiac surgery demonstrated successful MSC surface phenotyping and MSC differentiation. The mean cell count at the time of the second split was 1,628,025, and the mean time taken to reach the second split was 24.8 days. Conclusion: Herein, we describe the first reported technique of harvesting sternal bone marrow from patients already undergoing open-chest cardiac surgery to reduce the invasiveness of bone marrow harvesting, as well as the methods of isolating, culturing, and identifying MSCs for the clinical application of constructing autologous MSC-derived biomaterials.

A rare case of fat embolism syndrome secondary to abdominal liposuction and gluteal fat infiltration

Fat embolism syndrome (FES) is a rare, life-threatening condition habitually associated with traumatic events such as fractures and, less commonly, burns, liposuction and bone marrow harvesting and transplant [ 1]. The biochemical theory for this condition suggests that fat droplets embolize and convert into fatty acids, eventually leading to toxic injury and inflammation, which results in increased vascular permeability, edema and hemorrhage [ 2]. FES may have an asymptomatic interval lasting 12–72 hours after the insult; however, in some cases, signs have also been seen intraoperatively. Pulmonary signs and symptoms are customarily the earliest and manifest in 75% of patients. Nevertheless, neurologic and dermatologic manifestations are also characteristic, and most severe cases could perhaps present with disseminated intravascular coagulation, right ventricular dysfunction, shock or death. The following case consists of a 37-year-old patient that presented with fat embolism syndrome during liposuction and gluteal fat infiltration.

Late-onset coronary thrombosis and thrombocytosis following G-CSF treatment in a healthy donor: A Case Report

Granulocyte colony stimulating factor (G-CSF) has been widely used as a mobilizing agent to rapidly increase peripheral blood stem and progenitor cells. Limited data is available for G-CSF-associated late-onset coronary thrombosis and thrombocytosis. We report a case of a 23-year-old Chinese Han patient who presented with acute myocardial infarction and thrombocytosis after finishing bone marrow harvesting and peripheral blood stem cell collection following G-CSF treatment several days later. By using antiplatelet drugs and undergoing percutaneous transluminal coronary angioplasty, the patient’s symptoms were relieved and his platelet level decreased to normal. This is the first suspected case report of late-onset coronary thrombosis and thrombocytosis related to G-CSF. Caution should be taken for the delayed adverse reactions in patients undergoing G-CSF mobilizing.

The effect of a single consecutive volume aspiration on concentrated bone marrow from the proximal humerus for clinical application

Background Low aspiration volumes have been recommended to allow for higher concentrations of progenitor cells during bone marrow harvesting. However, these guidelines then require multiple aspiration attempts in order to maximize cellular yield. The purpose of this study was to investigate the effect of a single, high-volume aspiration with four consecutive aliquots on the number of nucleated cells (NCs) and colony-forming units (CFUs) in concentrated bone marrow aspirate (cBMA) taken from the proximal humerus. Methods cBMA was taken from the proximal humerus of patients undergoing arthroscopic rotator cuff surgery. Four 12-mL double syringes were used consecutively from a single trocar to obtain four 10 cc aliquots. Each then underwent centrifugation to create a fractionated layer rich in nucleated cells. Following cellular separation, NCs were counted and CFUs were evaluated after incubation of 7–10 days. Cellular comparisons between each aliquot were performed along with their interaction with patient age and sex. Results Twenty-nine patients (55.9 ± 4.6 years) were included in this study. The number of NCs and CFUs showed significant differences between the four aliquots of aspirate, with the first 10 cc aliquot providing the highest amount (p < 0.001, respectively). No significant differences were found between the sum of the three sequential aliquots compared to the initial 10 cc sample. There were no significant differences between male and female patients (p > 0.05). Increasing age resulted in no significant decrease in the number of NCs and CFUs across the four consecutive aliquots (p > 0.05). Conclusion In conclusion, while the initial aliquot provided the greatest number of nucleated cells and cultured CFUs, the addition of each sequential volume aspirate yielded similar amounts in total. This demonstrates the potential effectiveness of obtaining of higher volume aspirates from the proximal humerus during rotator cuff repair.

Outcomes of autologous blood collection prior to bone marrow harvest for matched unrelated donors.

e18535 Background: Autologous (auto) blood collection prior to bone marrow (BM) harvest is a common procedure however there is little data to say whether this is beneficial. Methods: This is a retrospective study evaluating the efficacy of pre-op auto blood collection in healthy unrelated donors who underwent BM harvesting at our institution between 9/2009 and 8/2017. Unrelated donors aged 18 or older who underwent their first BM harvest were included. Comparisons were made using two sample t-tests. Results: Among the 73 BM donors, 54 (74%) underwent auto blood collection resulting in 78 units collected. The cohorts with and without auto blood collected were similar in age and gender (mean age 31.0 vs 30.2; female 59% vs 41%). Those with auto blood collected donated larger volumes of marrow (mean 1395 mL vs 799 mL, p = 0.0002). Baseline hemoglobin (Hb) was similar between the cohorts (mean 14.1 g/dL vs 14.0 g/dL, p = 0.87). However, those with auto blood collected had lower pre-harvest (mean 13.1 g/dL vs 13.8 g/dL, p = 0.0430) and post-harvest Hb (mean 10.0 g/dL vs 11.3 g/dL, p = 0.0120). Of the 78 auto blood units collected, 45 units (58%) were used with 92% of women and 56% of men receiving their auto blood post-op. 33 (42%) auto blood units were discarded. Donors who were given back their auto blood were more likely to be female and have lower pre- and post-harvest Hb. Reasons for auto blood transfusion were blood availability (31%), donor post-op symptoms (i.e. hypotension, dizziness, syncope, and bleeding; 23%), intra-operative transient hypotension (26%), post-op anemia (11%) and patient request (9%). None of the patients who were transfused auto blood, or donors without auto blood collection, required allogeneic blood. Conclusions: Based on our results, collection of auto blood prior to bone marrow harvest leads to lower pre-op Hb and increases the likelihood of post-op blood transfusion. In addition, availability of auto blood can lead to over transfusion which may be detrimental to donor health. Although there may be a subset of donors who might benefit, routine auto blood collection prior to bone marrow harvesting is unnecessary and can be potentially hazardous to donors.