Academic literature on the topic 'Blood Preservation – instrumentation'

The “Hummer” microdebrider is a powered rotary shaving device with continuous suction. Its use in functional endoscopic sinus (FES) surgery allows precise and delicate removal of diseased tissue. Traditional FES instruments frequently cause trauma to non-diseased mucosa or inadvertently strip mucous membranes, both of which are counter to the functional concepts. The “Hummer” facilitates preservation of mucosa and vital structures, such as the middle turbinate, by resecting diseased, obstructive tissue with very limited blood loss. Simultaneous continuous suction at the operative site is a marked benefit of this instrument, which helps overcome the well-recognized problem of blood pooling that increases the potential for operative morbidity. Polypectomies are performed in a more precise manner with very little blood loss so that visibility is usually unimpaired, even in patients with cystic fibrosis. The instrument is applicable to most FES cases and is the authors’ preferred technique, even for small pediatric patients. Accelerated healing and reduced synechiae were observed in these patients.

It is well known that hemodynamic factors, such as blood pressure and flow, exert an important influence on native morphology of various animal organs. However, information about the significance of ultrastructures which are revealed by conventional preparation methods has been limited, because routine chemical fixation of cells and tissues takes considerable time, during which their morphology could easily change. Therefore, morphological studies with routine immersion or perfusion fixation have not revealed real ultrastructures of functioning animal organs with normal blood circulation.2 The ultimate goal of morphological study is that all features to be examined should reflect the physiological meaning under investigation. For that purpose, the preservation of cells and tissues in functioning organs is necessary for studies to define their ultrastructures. Most cryotechniques have been based on the use of prior excised tissues. Such small specimens are commonly frozen within several seconds following the excision of the tissues.

Prosthetic mechanical heart valves (MHVs) made from pyrolytic carbon (PYC) are a highly successful biomaterial application due to their excellent durability and clinically adequate blood compatibility. Their thromboresistance has been attributed to a combination of hemodynamics, material inertness, and surface properties which minimize platelet adhesion and activation. These surface properties include that polished PYC is smooth and that it strongly adsorbs plasma albumin, which is well known to reduce platelet adhesion. However, recent evidence suggests that this explanation is incomplete. Low voltage SEM shows that PYC valve leaflets are actually quite rough at submicron scales and that PYC induces extensive platelet spreading in vitro in the presence of albumin. Surprisingly few studies have examined MHVs explanted from humans or research animals for platelet adhesion and thrombosis using SEM. Moreover, in most studies it appears that even routine sample preparation methods for the preservation of biological samples for SEM,

Abstract: The purpose of this study was to determine whether a polymer could be formed from relatively innocuous monomeric ingredients and, if so, if it might serve as a suitable embedding medium for maximizing antigen retention. Such a polymer, HACH, was made up from a mixture of 2-hydroxyhexanedial and carbohydrazide. It polymerized spontaneously at room temperature within 24 hr. Preservation of protein antigenicity and subsequent immunocytochemical localization were demonstrated by three methods. To determine whether protein antigens were retained up to the polymerization stage, we studied hemoagglutination of red blood cells using antibodies directed against their protein antigens. In these trials, HACH-treated cells exhibited the same agglutination responses as control, untreated cells. Second, a guinea pig antibody was used to immunodecorate insulin in β cells of the islets of Langerhans. The number of gold particles, indicating sites where the antibody was bound, was several-fold greater in HACH- than in Lowicryl K4M-embedded pancreatic β cells. To assess the limit of detection of protein antigens in thin sections, an example of a protein present in mitochondria, lipoamide dehydrogenase, was also studied. An indirect procedure for immunodecoration, employing rabbit immunoglobulin G followed by gold-tagged secondary antibody, indicated that the enzyme was present at several sites within cross-sectioned mitochondria. The results suggest that the HACH polymer will be useful for the localization of antigens that are present in relatively few copies.

Abstract This operative video demonstrates a C1 lateral mass instrumentation technique that is an alternative to the traditional Goel and Harms techniques.1,2 The advantages of the alternative technique include minimized blood loss from the rich venous plexus surrounding the C2 dorsal root ganglia (DRG), avoidance and preservation of the C2 DRG, and placement of a robust fully threaded screw without risking neuralgia. These are discussed in detail and presented through a case of atlantoaxial instability. Patient's consent was obtained for creating this surgical video. The patient is a 50-yr-old woman with a 17-yr history of rheumatoid arthritis. She presented with 1 yr of neck pain that failed conservative measures. Flexion-extension radiographs demonstrated an atlantodental index (ADI) that reduced from 7 mm on flexion to 0 mm on extension. The patient underwent a C1-C2 posterior instrumented fusion using the alternative technique of C1 lateral mass instrumentation.2 The steps of this technique are explained in great detail through a microsurgical video. The patient's postoperative course was uneventful. Postoperative radiographs and computed tomography (CT) scan demonstrated reduction of ADI and well-placed instrumentation and fusion construct. Her neck pain was completely resolved by 3 mo following surgical stabilization. In the senior author's experience with placing over 120 C1 lateral mass screws with this alternative technique, there have been no instances of vascular injury, sacrifice of C2 DRG, or instrumentation failure. The alternative technique for placement of C1 lateral mass screw is safe, efficient, and holds certain advantages in comparison to the traditionally described method. Images within the video have been reproduced from AOSpine section of the AO Surgery Reference, www.aosurgery.org, with permission from AO Surgery. Copyright by AOSpine International, Switzerland; and reprinted from World Neurosurgery, 78(1-2), Kang MM et al, C2 Nerve Root Sectioning in Posterior C1-2 Instrumented Fusions, 170-177, Copyright 2012, with permission from Elsevier.

A number of operative techniques have been described for the treatment of herniated thoracic discs. The transfacet pedicle-sparing approach allows for complete disc removal with limited spinal column disruption and soft-tissue dissection. Fifteen cadaveric spinal columns were used for evaluation of exposure, development of thoracic microdiscectomy instrumentation, and establishment of morphometric measurements. This approach was used to remove eight thoracic discs in six patients. Levels of herniation ranged from T-7 through T-11. Preoperatively, all patients had moderate to severe axial pain, and three (50%) of the six had radicular pain. Myelopathy was present in four (67%) of the six patients. Through a 4-cm opening, the ipsilateral paraspinal muscles were reflected, and a partial facetectomy was performed. The disc was then removed using specially designed microscopic instrumentation. Postoperatively, the radiculopathy resolved in all patients. Axial pain and myelopathy were completely resolved or significantly improved in all patients. The minimal amount of bone resection and muscle dissection involved in the operation allows for: 1) decreased operative time and blood loss; 2) diminished perioperative pain; 3) shorter hospitalization time and faster return to premorbid activity; 4) avoidance of closed chest tube drainage; and 5) preservation of the integrity of the facet-pedicle complex, with potential for improvement in outcome related to axial pain. This technique appears best suited for the removal of all centrolateral discs, although it has been used successfully for treating a disc occupying nearly the entire ventral canal. The initial experience suggests that this approach may be used to safely remove appropriately selected thoracic disc herniations with good results.

✓ A number of operative techniques have been described for the treatment of herniated thoracic discs. The transfacet pedicle-sparing approach allows for complete disc removal with limited spinal column disruption and soft-tissue dissection. Fifteen cadaveric spinal columns were used for evaluation of exposure, development of thoracic microdiscectomy instrumentation, and establishment of morphometric measurements. This approach was used to remove eight thoracic discs in six patients. Levels of herniation ranged from T-7 through T-11. Preoperatively, all patients had moderate to severe axial pain, and three (50%) of the six had radicular pain. Myelopathy was present in four (67%) of the six patients. Through a 4-cm opening, the ipsilateral paraspinal muscles were reflected, and a partial facetectomy was performed. The disc was then removed using specially designed microscopic instrumentation. Postoperatively, the radiculopathy resolved in all patients. Axial pain and myelopathy were completely resolved or significantly improved in all patients. The minimal amount of bone resection and muscle dissection involved in the operation allows for: 1) decreased operative time and blood loss; 2) diminished perioperative pain; 3) shorter hospitalization time and faster return to premorbid activity; 4) avoidance of closed chest tube drainage; and 5) preservation of the integrity of the facet—pedicle complex, with potential for improvement in outcome related to axial pain. This technique appears best suited for the removal of all centrolateral discs, although it has been used successfully for treating a disc occupying nearly the entire ventral canal. The initial experience suggests that this approach may be used to safely remove appropriately selected thoracic disc herniations with good results.

Abstract Introduction Nitric oxide (NO) released by endothelial cells interacts with platelets in which it stimulates soluble guanylate cyclase (sGC), thereby increasing platelet cyclic guanosine monophosphate (cGMP) and inhibiting platelet activation. Stimulation of sGC in other cells has been suggested as an attractive target for intervention in a range of diseases including pulmonary arterial hypertension, heart failure, and diabetes mellitus. Riociguat, the first FDA-approved sGC stimulator, potently increases platelet cGMP and inhibits platelet aggregation in washed platelets. Because riociguat binds to plasma proteins, higher concentrations of riociguat are required to inhibit platelet function in whole blood. However the potential synergistic inhibition of platelet function by riociguat and NO has not been well studied. Goal To investigate the possible synergistic effects of riociguat and NO on platelet inhibition and to determine the effects of protein binding. Methods Platelet-rich plasma (PRP) was prepared from citrate (3.2%) anticoagulated whole blood collected from healthy donors following informed consent. Riociguat (10 mM) in DMSO and DETA-NONOate 10 mM (an NO donor) in 10 mM NaOH were stored at -80°C until use. PRP was diluted 10-fold in either HEPES-Tyrode's buffer or platelet poor plasma (PPP), then incubated with vehicle or riociguat 1, 10, or 100 µM, alone or in combination with DETA-NONOate 16, 31, or 250 µM for 30 minutes, then analyzed by flow cytometry. Platelet surface activated GPIIb-IIIa (detected by monoclonal antibody PAC1) and platelet surface P-selectin were measured with and without activation by ADP 5 µM or thrombin receptor activating peptide (TRAP) 5 µM. For light transmission platelet aggregation (LTA) and 96-well platelet aggregation, PRP was used without dilution. Results For PRP diluted in buffer, riociguat and DETA-NONOate each produced concentration-dependent inhibition of ADP- and TRAP-stimulated platelet activation, as reported by platelet surface activated GPIIb-IIIa (Figure A) and P-selectin, and a synergistic inhibitory effect was observed when riociguat and DETA-NONOate were combined (for platelet surface activated GPIIb-IIIa, 40% inhibition with 1 µM riociguat alone; 30% inhibition with 31 µM DETA-NONOate alone; 90% inhibition with 1 µM riociguat and 31 µM DETA-NONOate combined). In contrast, when PRP was diluted in PPP, the concentrations of riociguat alone and DETA-NONOate alone needed to inhibit activation were dramatically increased and the combination of 1 µM riociguat and 31 µM DETA-NONOate produced less than 10% inhibition of platelet surface activated GPIIb-IIIa (Figure B). Synergistic inhibition in plasma was observed when DETA-NONOate was increased to 250 µM. Based on these results, a sub-threshold concentration of DETA-NONOate was chosen for investigation of the effects of riociguat on platelet aggregation. Using ADP 5 µM, TRAP, 2 µM, or collagen 2 µg/mL, riociguat alone at 10 µM (Figure C) and DETA-NONOate alone at 31 µM showed no inhibition of platelet aggregation. However, in the presence of 31 µM DETA-NONOate, riociguat showed a concentration-dependent inhibition of aggregation by each agonist (Figure C). Conclusions Platelets exposed to riociguat in combination with sub-threshold concentrations of NO, such as may occur in microvessels adjacent to the endothelial layer, are inhibited from undergoing platelet activation and aggregation. The presence of plasma proteins blunts the effects of riociguat and has even larger effects on the NO donor, DETA-NONOate. Taken together, these data suggest that NO potently synergizes with riociguat to inhibit platelet activation and aggregation, but in vivo this effect likely only occurs immediately adjacent to endothelial cells where NO concentrations are highest. Figure. Figure. Disclosures Michelson: Alnylam, Instrumentation Laboratory, Surface Oncology: Consultancy; AstraZeneca, Chiesi, Dova, Janssen, LightIntegra, Megakaryon, Remora: Other: Scientific Advisory Board; Baxalta, Cellular Preservation Technologies, Ionis, Ironwood, Medtronic, Megakaryon, Pfizer, Sysmex: Research Funding. Frelinger:Surface Oncology: Consultancy; Cellular Preservation Technologies, Ironwood, Ionis, Medtronic, Megakaryon, Pfizer and Sysmex: Research Funding.

Object. Patients with metastatic spine tumors often have multicolumn involvement and high-grade epidural compression, requiring circumferential decompression and instrumentation. Secondary medical and oncological issues add morbidity to combined approaches. The authors present their experience in using the single-stage posterolateral transpedicular approach (PTA) to decompress the spine circumferentially and to place instrumentation. Methods. From September 1997 to February 2004, 140 patients with spine metastases underwent the PTA. Magnetic resonance imaging revealed high-grade spinal cord compression in 120 patients (86%) and lytic vertebral body destruction in all patients. Preoperatively 84 patients (60%) received radiotherapy directed to the involved level and 42 (30%) underwent tumor embolization. Following circumferential decompression, all patients underwent anterior reconstruction with polymethylmethacrylate and Steinmann pins, and posterior segmental fixation. The median operative time was 5.1 hours, the median blood loss was 1500 ml, and the median hospital stay was 9 days. Ninety-six percent of the patients experienced postoperative pain improvement and improvement in or stabilization of neurological status. In 51 nonambulatory patients with poor Eastern Cooperative Oncology Group grades, 75% regained the ability to walk. One month postoperatively 90% of patients achieved good-to-excellent performance scores. The overall median patient survival time was 7.7 months. Patients with colon and lung carcinomas had significantly shorter survival times. Major operative complications occurred in 20 patients (14.3%). Wound complications occurred in 16 patients (11.4%), but this was not correlated with preoperative radiation treatment. Conclusions. The PTA allows circumferential epidural tumor decompression and the placement of anterior and posterior spinal column instrumention. Immediate spinal stability is achieved without the use of brace therapy. This technique achieved a high success rate for pain palliation, neurological preservation, and functional improvement, while avoiding the morbidity associated with combined approaches.

e14675 Background: Cancer can affect the bone marrow, cause anemia and internal or excess bleeding, requiring blood or plasma transfusion. Fresh frozen plasma (FFP) should be thawed before transfusing to patients but it must be monitored closely to avoid contamination, uncontrolled or prolonged thawing which may subsequently lead to plasma protein denaturation. In this study, we compared and evaluated the effect of two different thawing methods on clotting factor activities as well as factors such as throughput and turnaround time. Methods: Over a period of approximately one month, November 6 to December 3, 2018, our testing laboratory at the UCSD School of Medicine received three sets of samples for a total of 197 freshly collected (pre-freeze) or freshly thawed plasma samples (standard commercial thawing device and the new dry ZipThaw device) that had been collected and processed in accordance with a San Diego Blood Bank protocol described elsewhere. The Lab conducted over 1,782 tests on these plasma for the following factors: Prothrombin time (PT), International Normalized Ratios (INR), Activated Partial Thromboplastin time (aPTT) Factor VIII activity, Factor V activity, Protein C activity, Protein S antigen, Von Willebrand activity and Thrombin Antithrombin Complex (TAT) concentration. The assays were carried out on an ACL TOP 700 Hemostasis Analyzer (Instrumentation Laboratory, Bedford, MA, USA) using manufacturer’s reagents and automated protocols. The ACL TOP 700 has validated precision CV of 5- 10%. All assays were completed within 4 hours of collection or, if frozen, within 4 hours of thawing. The statistical analysis method employed is two-tailed, student t-test. Results: We observed 100% concordance with no statistically significant differences between the pre-freeze group and the two different post thaw groups, except for a slight increase in the mean TAT complex concentration. Overall, the means of all three groups were well within the normal range defined by the assay kits (1-10 ng/ml). Further, the increased mean TAT is more notable with standard method (33%, p = 0.004) than with the ZipThaw (18%, p = 0.054). Conclusions: We report for the first time non-inferiority between the new ZipThaw device and the leading commercial predicate in plasma thawing while preserving coagulation and anticoagulation proteins and minimizing activation of clotting cascade. The results provide support for the use of ZipThaw device in clinical settings.

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Medicine in the branch of Anaesthesiology Johannesburg, 2019
Background Anaesthesia frequently involves administration of refrigerated intravenous drugs to patients. Often overlooked, maintenance of the cold chain forms a key component of pharmacovigilance for anaesthetists. However the South African national Department of Health guidelines on: “Cold Chain and Immunisation Operations Manual”, does not detail specific requirements for medically validated cold boxes. Consequently the risk of iatrogenic harm to patients from heat-sensitive pharmaceuticals in inappropriately temperature regulated cold boxes exists. Methods The research design was that of a descriptive, prospective and contextual study. Part I study population comprised the ambient air temperatures of the refrigerator and cold boxes used for storage of heat-sensitive pharmaceuticals in theatre at CHBAH taken at one minute intervals over eight hours. Part II study population was newly purchased cold boxes and cold packs for the purpose of assessing individual cold box thermal performance over eight hours. Results In Part I, only a single cold box (polystyrene box number 19) was able to maintain the recommended temperature range of 2 − 8°C for the eight hour period (4.35%). The refrigerator temperature time plot showed a significant deviation of temperature at approximately 30 minutes. In Part II, only fabric and polystyrene cold boxes with three cold packs in situ were able to maintain the recommended temperature of 2 − 8°C. Conclusion This study highlighted the failure of non-medically validated cold boxes to reliably maintain the temperature of heat-sensitive pharmaceuticals.
E.K. 2019