Use of Floseal®, a human gelatine-thrombin matrix sealant, in surgery: a systematic review

Is Totally Tubeless Percutaneous Nephrolithotomy a Safe and Efficacious Option for Complex Stone Disease?

Background: Percutaneous nephrolithotomy is the gold standard treatment for large, complex intrarenal stones. Historically, this was performed using a nephrostomy tube (PCN) and/or internalized ureteral stent at the end of the procedure. However, totally tubeless nephrolithotomy (tt-PCNL) is a novel technique where no tubes (no stent nor nephrostomy tube) are left post-operatively. We review the literature on this subject regarding peri-operative outcomes, post-operative outcomes, and potential complications of the procedure, discuss our technique, and make recommendations on implementation for centers not currently utilizing the procedure. Materials and methods: We performed a comprehensive search of the literature on totally tubeless nephrolithotomy using MEDLINE database search. Our search included prior review articles, meta-analyses, systematic reviews, primary research articles, case reports, and case studies. Results: In comparison to prior approaches where a stent or nephrostomy tube is placed, tt-PCNL has a similar complication rate and better post-operative outcomes. Totally tubeless PCNL has similar operative times and similar changes in hemoglobin. However, it had shorter length of stays across all studies. The mean difference in length of stay in the studies reviewed was 1.96 days. Additionally, tt-PCNL had decreased post-operative analgesic requirements and pain scores. Conclusions: This review highlights totally tubeless percutaneous nephrolithotomy as a safe and feasible surgical technique with improved outcomes in properly selected patients.

Topical Hemostatic Agents and Risk of Postoperative Hemorrhage After Transoral Robotic Surgery

Objective: Postoperative hemorrhage is the most common complication of transoral robotic surgery (TORS). The available research literature on topical hemostatic agents is deficient, despite their wide use. This study aims to evaluate the frequency and severity of hemorrhagic events after TORS procedures, performed with various topical hemostatic agents. Methods: This study was planned as a retrospective review to identify postoperative hemorrhage events in a database of all consecutive adult patients who required TORS from January 1, 2015, to April 1, 2020. All procedures were performed in one single institution by the same surgeon. In 2017, bovine gelatin matrix with thrombin (BgMT) was replaced by the porcine gelatin matrix with thrombin (PgMT) for all procedures. Postoperative hemorrhage was identified, along with hemostatic agents employed and other variables. Results: A cohort of 80 TORS procedures was obtained from a population of 78 individuals (60 males:18 females). BgMT was used in 28 procedures (35%), and five cases of postoperative hemorrhage were identified (17.8%), two of them were severe. PgMT was used in 52 procedures (65%) just observing one minor hemorrhagic event (1.92%). Although a significant difference was observed for total events between groups (P = .0183), there was no difference between major or severe hemorrhagic events (P = .1196). The overall rate of major and severe postoperative hemorrhage in the study population was 2.5% (n = 80). Conclusions: This is the first study to evaluate topical hemostatic agents during TORS procedures. The PgMT group had a reduced incidence of total postoperative hemorrhages, although there was no difference in the number of severe hemorrhagic events. The overall simplicity and cost-effectiveness of these agents would support their use, particularly considering the potential risk associated with airway hemorrhage.

Effectiveness of a thrombin-gelatin flowable for treating severe liver bleeding: an experimental study

BACKGROUND

Current scientific evidence has pointed out the relevance of hemostatic products for improving clinical outcomes in liver trauma, including increased survival rates and reductions in bleeding-related complications. The purpose of this study was to compare the use of the gelatin-thrombin flowable (Flowable) versus the standard technique of Packing in a new experimental liver injury model.

METHODS

Twenty-four swine were prospectively randomized to receive either Flowable or standard packing technique. We used a novel severe liver injury model, in which the middle and left suprahepatic veins were selectively injured, causing an exsanguinating hemorrhage. The main outcome measure was the percentage of lost blood volume.

RESULTS

The median total percentage of total blood volume per animal lost, from injury to minute 120, was significantly lower in the Flowable group (15.2%; interquartile range: 10.7-46.7%) than in the Packing group (64.9%; Interquartile range: 53.4-73.0%) (Hodges-Lehmann median difference: 41.1%; 95% CI: 18.9-58.0%, p = 0.0034). The 24-hour survival rate was significantly higher in the Flowable group (87.0%) than in the Packing group (0.0%) (Hazard ratio (HR) 0.08; 95% confidence interval 0.102 to 0.27; p < 0.0001). Mean-arterial pressure was significantly lower at minute 60 and 120 in the Flowable group than in the packing group (p = 0.0258 and p = 0.0272, respectively). At minute 120, hematocrit was higher in the Flowable than in the packing group (Hodges-Lehmann median difference: 5.5%; 95%CI: 1.0 to11.0, p = 0.0267). Finally, the overall-surgical-procedure was significantly shorter with Flowable than with Packing (Hodges-Lehmann median difference: 39.5 s, 95% CI: 25.0 to 54.0 s, p = 0.0004).

CONCLUSIONS

The use of the Flowable was more effective in achieving hemostasis, reducing blood loss, and improving survival rates than standard packing in a severe porcine-liver bleeding model.

Thrombin and Thrombin-Incorporated Biomaterials for Disease Treatments

Thrombin, a coagulation-inducing protease, has long been used in the hemostatic field. During the past decades, many other therapeutic uses of thrombin have been developed. For instance, burn treatment, pseudoaneurysm therapy, wound management, and tumor vascular infarction (or tumor vasculature blockade therapy) can all utilize the unique and powerful function of thrombin. Based on their therapeutic effects, many thrombin-associated products have been certificated by the Food and Drug Administration, including bovine thrombin, human thrombin, recombinant thrombin, fibrin glue, etc. Besides, several thrombin-based drugs are currently undergoing clinical trials. In this article, the therapeutic uses of thrombin (from the initial hemostasis to the latest cancer therapy), the commercially available drugs associated with thrombin, and the pros and cons of thrombin-based therapeutics (e.g., adverse immune responses related to bovine thrombin, thromboinflammation, and vasculogenic "rebounds") are summarized. Further, the current challenges and possible future research directions of thrombin-incorporated biomaterials and therapies are discussed. It is hoped that this review may provide a valuable reference for researchers in this field and help them to design safer and more effective thrombin-based drugs for fighting against various intractable diseases.

Expert panel recommendations for topical hemostatic agent use in varied bleeding sites and situations during neuro-spine surgeries

Intraoperative bleeding poses a substantial challenge, particularly in neuro-spine surgeries leading to complications such as hematomas, infections, and hemodynamic instability. Despite their proven efficacy, use of topical hemostatic agents (THAs) lacks comprehensive published literature and guidelines particularly in the Indian setting. The present study provides the first-ever Indian expert panel recommendations for effective adjunct THA use in different intraoperative bleeding sites and situations in neuro-spine surgeries. A comprehensive approach, encompassing a literature review, followed by experience sharing in a meeting using a survey helped integrate expert opinions in the form of practical algorithms to guide THA selection. Our survey results revealed a strong inclination towards specific THAs, flowable gelatin + thrombin being choice of THA for difficult to access and problematic bleeding situations during tumor removal/resection, transsphenoidal hypophysectomy and skull-based procedures. Both oxidized regenerated cellulose (ORC)/Fibrillar and flowable gelatin + thrombin were recommended for continuous oozing. ORC/Fibrillar was preferred for arteriovenous and cavernous malformations. This expert-panel guidance on THA use aims to optimize hemostat use practices and improve surgical outcomes in neuro-spine surgery.

Comparison of a gelatin thrombin versus a modified absorbable polymer as a unique treatment for severe hepatic hemorrhage in swine

There are many surgical techniques (packing, Pringle maneuver, etc.) and hemostatic agents to manage hepatic bleeding in trauma surgery. This study compares the effectiveness of two different types of hemostatic agents, one is an active flowable hemostat and the other is a passive hemostat made of modified absorbable polymers [MAP]. Both surgical technique and hemostatic agents can be used together as a means of controlling bleeding. We have hypothesized that a single hemostatic agent might be as effective as a unique hemostatic surgical technique. Twenty swine were prospectively randomized to receive either active Flowable (Floseal) or passive MAP powder (PerClot) hemostatic agents. We used a novel severe liver injury model that caused exsanguinating hemorrhage. The main outcome measure was total blood loss volume. The total volume of blood loss, from hepatic injury to minute 120, was significantly lower in the Flowable group (407.5 cm3; IqR: 195.0-805.0 cm3) compared to MAP group (1107.5 cm3; IqR: 822.5 to 1544.5 cm3) (Hodges-Lehmann median difference: - 645.0 cm3; 95% CI: - 1144.0 to - 280.0 cm3; p = 0.0087). The rate of blood loss was significantly lower in the flowable group compared with the MAP group as measured from time of injury to minutes 3, 9, 12, and 120 (except for 6 min). The mean arterial pressure gradually recovered in the flowable group by 24 h, whereas in the MAP group, the mean arterial pressure was consistently stayed below baseline values. Kaplan-Meier survival analysis indicated similar rates of death between study groups (Logrank test p = 0.3395). Both the flowable and the MAP hemostatic agents were able to effectively control surgical bleeding in a novel severe liver injury model, however, the flowable gelatin-thrombin agent provided quicker and better bleed control.

Ruggedized Self-Propelling Hemostatic Gauze Delivers Low Dose of Thrombin and Systemic Tranexamic Acid and Achieves High Survival in Swine With Junctional Hemorrhage

INTRODUCTION

Hemorrhage is responsible for 91% of preventable prehospital deaths in combat. Bleeding from anatomic junctions such as the groin, neck, and axillae make up 19% of these deaths, and reports estimate that effective control of junctional hemorrhage could have prevented 5% of fatalities in Afghanistan. Hemostatic dressings are effective but are time-consuming to apply and are limited when proper packing and manual pressure are not feasible, such as during care under fire. CounterFlow-Gauze is a hemostatic dressing that is effective without compression and delivers thrombin and tranexamic acid into wounds. Here, an advanced prototype of CounterFlow-Gauze, containing a range of low thrombin doses, was tested in a lethal swine model of junctional hemorrhage. Outcomes were compared with those of Combat Gauze, the current dressing recommended by Tactical Combat Casualty Care.

MATERIALS AND METHODS

CounterFlow-Gauze containing thrombin doses of 0, 20, 200, and 500 IU was prepared. Swine received femoral arteriotomies, and CounterFlow-Gauze was packed into wounds without additional manual compression. In a separate study using a similar model of junctional hemorrhage without additional compression, CounterFlow-Gauze containing 500 IU thrombin was tested and compared with Combat Gauze. In both studies, the primary outcomes were survival to 3 h and volume of blood loss.

RESULTS

CounterFlow-Gauze with 200 and 500 IU had the highest 3-h survival, achieving 70 and 75% survival, respectively. CounterFlow-Gauze resulted in mean peak plasma tranexamic acid concentrations of 9.6 ± 1.0 µg/mL (mean ± SEM) within 3 h. In a separate study with smaller injury, CounterFlow-Gauze with 500 IU achieved 100% survival to 3 h compared with 92% in Combat Gauze animals.

CONCLUSIONS

An advanced preclinical prototype of CounterFlow-Gauze formulated with a minimized thrombin dose is highly effective at managing junctional hemorrhage without compression. These results demonstrate that CounterFlow-Gauze could be developed into a feasible alternative to Combat Gauze for hemorrhage control on the battlefield.

Effects of Thrombin-Based Hemostatic Agent in Total Knee Arthroplasty: Meta-Analysis

The effectiveness of Floseal, a thrombin-based hemostatic matrix, in total knee arthroplasty (TKA) in minimizing blood loss and transfusion requirements remains a topic of debate. This meta-analysis aims to evaluate the up-to-date randomized controlled trials (RCTs) on the efficacy and safety of Floseal in TKA. A comprehensive search was conducted in electronic databases to identify relevant RCTs. The methodological quality of the included studies was assessed, and data extraction was performed. The pooled effect sizes were calculated using standardized mean difference (SMD) or odds ratios (OR) with 95% confidence intervals (CIs). Eight studies involving 904 patients were included in the meta-analysis. The use of a thrombin-based hemostatic agent significantly reduced hemoglobin decline (SMD = -0.49, 95% CI: -0.92 to -0.07) and the risk of allogenic transfusion (OR = 0.45, 95% CI: 0.25 to 0.81) but showed no significant difference in the volume of drainage or total blood loss. Funnel plots showed no evidence of publication bias. This meta-analysis provides robust evidence supporting the effectiveness of Floseal in reducing hemoglobin decline and transfusion in TKA. Further well-designed RCTs with longer follow-up periods are warranted to assess long-term efficacy and safety.

Long-term Intense 18F-FDG Uptake by the Homeostatic Matrix-associated Inflammatory Response May Mimic Malignancy Recurrence

A 70-year-old man underwent right upper lobectomy for lung adenocarcinoma. During the operation, hemostatic matrix (as known Floseal®) was used to prevent pulmonary laceration-associated bleeding. When 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography was performed for staging after surgery, intense 18F-FDG uptake was observed in the cicatricial fibrotic tissue in the operation area, and no significant change was observed in that area during the 4-year follow-up. Because it remained stable for several years without treatment, this finding was thought to be due to a foreign body reaction caused by the homeostatic material.

Short Peptide Nanofiber Biomaterials Ameliorate Local Hemostatic Capacity of Surgical Materials and Intraoperative Hemostatic Applications in Clinics

Short designer self-assembling peptide (dSAP) biomaterials are a new addition to the hemostat group. It may provide a diverse and robust toolbox for surgeons to integrate wound microenvironment with much safer and stronger hemostatic capacity than conventional materials and hemostatic agents. Especially in noncompressible torso hemorrhage (NCTH), diffuse mucosal surface bleeding, and internal medical bleeding (IMB), with respect to the optimal hemostatic formulation, dSAP biomaterials are the ingenious nanofiber alternatives to make bioactive neural scaffold, nasal packing, large mucosal surface coverage in gastrointestinal surgery (esophagus, gastric lesion, duodenum, and lower digestive tract), epicardiac cell-delivery carrier, transparent matrix barrier, and so on. Herein, in multiple surgical specialties, dSAP-biomaterial-based nano-hemostats achieve safe, effective, and immediate hemostasis, facile wound healing, and potentially reduce the risks in delayed bleeding, rebleeding, post-operative bleeding, or related complications. The biosafety in vivo, bleeding indications, tissue-sealing quality, surgical feasibility, and local usability are addressed comprehensively and sequentially and pursued to develop useful surgical techniques with better hemostatic performance. Here, the state of the art and all-round advancements of nano-hemostatic approaches in surgery are provided. Relevant critical insights will inspire exciting investigations on peptide nanotechnology, next-generation biomaterials, and better promising prospects in clinics.

A prospective randomised controlled trial evaluating prophylactic Floseal, a gelatin and thrombin-based haemostatic matrix, in postoperative drain output and blood transfusion in transforaminal lumbar interbody fusion surgery

PURPOSE

To evaluate the prophylactic use of Floseal in reducing postoperative blood loss in patients undergoing Transforaminal Lumbar Interbody Fusion (TLIF). TLIF is a lumbar spine decompression and fusion procedure with potential for postoperative blood loss. Prophylactic application of Floseal, a gelatin and thrombin-based haemostatic matrix to the surgical wound before closure was shown to be effective in reducing postoperative drain output in anterior cervical discectomy and fusion. This study postulated that prophylactic use of Floseal before wound closure would reduce postoperative blood loss in patients who underwent TLIF.

METHODS

Randomised controlled trial comparing prophylactic use of Floseal and control in patients undergoing single level or two-level TLIF. Primary outcomes included postoperative drain output within 24 h and postoperative transfusion rate. Secondary outcomes included days of drain placement, length of stay and haemoglobin level.

RESULTS

A total of 50 patients was recruited. Twenty six patients were allocated to the Floseal group and 24 were allocated to the control group. There were no baseline characteristic differences between the groups. There were no statistically significant differences in primary outcomes which included postoperative drain output within 24 h and postoperative transfusion rate between patients who received prophylactic Floseal and control. There were no statistically significant differences in secondary outcomes which included haemoglobin level, days of drain placement and length of stay between the two groups.

CONCLUSION

Prophylactic use of Floseal was not shown to reduce postoperative bleeding in single level or two-level TLIF.

Effect of Gelatin-Based Hemostats on Fibroblasts and Relevant Growth Factors in Wound Healing

Gelatin-based hemostats have been used in various surgical fields and showed advantageous effects on central aspects of wound healing when compared to cellulose-based hemostats. Nevertheless, the influence of gelatin-based hemostats on wound healing has not been fully explored yet. Hemostats were applied to fibroblast cell cultures for 5, 30, 60 min, 24 h, 7 and 14 days and measurements were taken at 3, 6, 12, 24 h and 7 or 14 days, respectively. Cell proliferation was quantified after different exposure times and a contraction assay was conducted to measure the extent of the extracellular matrix over time. We further assessed quantitative levels of vascular endothelial growth factor and basic fibroblast growth factor using enzyme-linked immunosorbent assay. Fibroblast counts decreased significantly at 7 and 14 days independent of the application duration (p < 0.001 for 5 min application). The gelatin-based hemostat did not have a negative impact on cell matrix contraction. After application of gelatin-based hemostat, the basic fibroblast growth factor did not change; yet, the vascular endothelial growth factor significantly increased after a prolonged 24 h application time when compared to controls or to a 6 h exposure (p < 0.05). Gelatin-based hemostats did not impair contraction of the extracellular matrix or growth factor production (vascular endothelial growth factor and basic fibroblast growth factor), while cell proliferation diminished at late time points. In conclusion, the gelatin-based material seems to be compatible with central aspects of wound healing. For further clinical assessment, future animal and human studies are necessary.

Haemostatic efficacy and inflammatory response of a novel beta-chitin patch in a cerebral small vessel injury model - A pilot study

OBJECTIVE

Rapid and efficacious haemostasis is paramount in neurosurgery. Assessing the efficacy and short- and long-term safety of haemostatic agents utilised within cerebral tissue is essential. This pilot study investigates the haemostatic efficacy and long-term safety of a novel beta-chitin patch against traditionally used agents, bipolar and Floseal, within cerebral tissue.

METHODS

Eighteen Merino sheep underwent standardised distal cortical vessel injury via temporal craniotomy. Sheep were randomised to receive 2 mls Floseal, 2 cm novel beta-chitin patch, or bipolar cautery to manage bleeding. All sheep underwent cerebral magnetic resonance imaging (MRI) at three months, before euthanasia and brain harvesting for histological assessment.

RESULTS

Beta-chitin demonstrated a trend towards a faster mean time to haemostasis (TTH) compared to Floseal (223.3 ± 199 s v. 259.8 ± 186.4 s), albeit non-significant (p = 0.234). Radiologically, cerebrocortical necrosis (p = 0.842) and oedema (p = 0.368) were noted slightly more frequently in the beta-chitin group. Histologically, severe fibrotic (p = 0.017) and granulomatous changes at the craniotomy sites were only present in the beta-chitin group (p = 0.002). Neuronal degeneration was seen in all with Floseal, but beta-chitin showed a trend towards more severe reaction when present. Bipolar use predominantly showed an inflammatory cortical reaction with substantial microvascular proliferation, and Floseal showed worse severity and depth of subpial oedema, however no statistical significance was reached.

CONCLUSION

All haemostats controlled bleeding, with beta-chitin demonstrating a non-inferior TTH compared to Floseal. However, it resulted in intense granulomatous and fibrotic changes, including degenerative neuronal reactions. More extensive studies are needed to assess these trends, to make further clinical inferences.

Tissue adhesive hemostatic microneedle arrays for rapid hemorrhage treatment

Blood loss by hemorrhaging wounds accounts for over one-third of ∼5 million trauma fatalities worldwide every year. If not controlled in a timely manner, exsanguination can take lives within a few minutes. Developing new biomaterials that are easy to use by non-expert patients and promote rapid blood coagulation is an unmet medical need. Here, biocompatible, and biodegradable microneedle arrays (MNAs) based on gelatin methacryloyl (GelMA) biomaterial hybridized with silicate nanoplatelets (SNs) are developed for hemorrhage control. The SNs render the MNAs hemostatic, while the needle-shaped structure increases the contact area with blood, synergistically accelerating the clotting time from 11.5 min to 1.3 min in vitro. The engineered MNAs reduce bleeding by ∼92% compared with the untreated injury group in a rat liver bleeding model. SN-containing MNAs outperform the hemostatic effect of needle-free patches and a commercial hemostat in vivo via combining micro- and nanoengineered features. Furthermore, the tissue adhesive properties and mechanical interlocking support the suitability of MNAs for wound closure applications. These hemostatic MNAs may enable rapid hemorrhage control, particularly for patients in developing countries or remote areas with limited or no immediate access to hospitals.

Predictors for hemostatic thrombin-gelatin matrix usage in spine surgery: a multicenter observational study

STUDY DESIGN

A prospective cohort study.

OBJECTIVES

Thrombin-gelatin matrix (TGM) is a rapid and potent hemostatic agent, but it has some limitations, including the cost and its preparation time. The purpose of this study was to investigate the current trend in the use of TGM and to identify the predictors for TGM usage in order to ensure its proper use and optimized resource allocation.

METHODS

A total of 5520 patients who underwent spine surgery in a multicenter study group within a year were included in the study. The demographic factors and the surgical factors including spinal levels operated, emergency surgery, reoperation, approach, durotomy, instrumented fixation, interbody fusion, osteotomy, and microendoscopy-assistance were investigated. TGM usage and whether it was routine or unplanned use for uncontrolled bleeding were also checked. A multivariate logistic regression analysis was used to identify predictors for unplanned use of TGM.

RESULTS

Intraoperative TGM was used in 1934 cases (35.0%), among which 714 were unplanned (12.9%). Predictors of unplanned TGM use were female gender (adjusted odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.02-1.43, p = 0.03), ASA grade ≥ 2 (OR: 1.34, 95% CI: 1.04-1.72, p = 0.02), cervical spine (OR: 1.55, 95% CI: 1.24-1.94, p < 0.001), tumor (OR: 2.02, 95% CI: 1.34-3.03, p < 0.001), posterior approach (OR: 1.66, 95% CI: 1.26-2.18, p < 0.001), durotomy (OR: 1.65, 95% CI: 1.24-2.20, p < 0.001), instrumentation (OR: 1.30, 1.03-1.63, p = 0.02), osteotomy (OR: 5.00, 2.76-9.05, p < 0.001), and microendoscopy (OR: 2.24, 1.84-2.73, p < 0.001).

CONCLUSIONS

Many of the predictors for unplanned TGM use have been previously reported as risk factors for intraoperative massive hemorrhaging and blood transfusion. However, other newly revealed factors can be predictors of bleeding that is technically challenging to control. While routine usage of TGM in these cases will require further justification, these novel findings are valuable for implementing preoperative precautions and optimizing resource allocation.

Effectiveness of a Gelatin-Thrombin Matrix Sealant (Floseal®) for Reducing Blood Loss During Microendoscopic Decompression Surgery for Lumbar Spinal Canal Stenosis: A Retrospective Cohort Study

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To investigate the effectiveness and safety of a gelatin-thrombin matrix sealant (GTMS) during microendoscopic laminectomy (MEL) for lumbar spinal canal stenosis (LSCS).

METHODS

This study included 158 LSCS cases on hemostasis-affecting medication who underwent MEL by a single surgeon between September 2016 and August 2020. Patients were divided into 2 groups depending on whether GTMS was used (37 cases, Group A) or not (121 cases, Group B). Perioperative data related to bleeding or postoperative spinal epidural hematoma (PSEH) was investigated. Clinical outcomes were evaluated using the Japanese Orthopedic Association (JOA) score for low back pain.

RESULTS

The mean intraoperative blood loss per level was greater in Group A (26.0 ± 20.3 g) than in Group B (13.6 ± 9.0 g), whereas the postoperative drainage volume was smaller in Group A (79.1 ± 42.5 g) than in Group B (97.3 ± 55.6 g). No revision surgeries for PSEH were required in Group A, while 2 (1.7%) revisions were required in Group B (P = .957). The median JOA score improved significantly from the preoperative period to 1-year postoperatively in both Group A and B (total score, 16.0-23.5 and 17.0-25.0 points, respectively).

CONCLUSIONS

The use of GTMS during MEL for LSCS may be associated with a reduction in postoperative drainage volume. The revision rate for PSEH was not affected significantly by the use of GTMS. Clinical outcomes (represented by the JOA score) were significantly improved after the surgery, regardless of GTMS use during MEL.

Efficacy and safety of CounterFlow in animal models of hemorrhage

LAY SUMMARY

The efficacy of current hemostatic technologies is limited by several factors. Outward blood flow washes hemostatic drugs away from the wound, and hemostatic drugs often require focus, training, and time to use correctly, are highly specific to one type of injury, or pose severe safety risks. CounterFlow is a novel product that could potentially save military and civilian lives by stopping heavy bleeding from a variety of organs and other bodily locations that current technology cannot easily treat. Upon contact with blood, CounterFlow releases bursts of gas to safely self-propel bio-degradable clot-forming and clot-stabilizing drugs against blood flow, delivering them to the source of bleeding. This unique mechanism allows CounterFlow to be applied quickly to a wide assortment of wounds and to act effectively with little management after application. CounterFlow was tested in multiple animal models representing common and deadly bleeding scenarios, including internal bleeding, care under fire without compression, and surgical bleeding, and it was found to outperform current care options by stopping bleeds faster and increasing survival times. CounterFlow is also safe to use and biocompatible. This narrative review summarizes studies testing the effectiveness and safety of CounterFlow, discusses useful applications, and describes future plans for the product.

Time-dependent effects of cellulose and gelatin-based hemostats on cellular processes of wound healing

INTRODUCTION

Oxidized regenerated cellulose-based (ORC - TABOTAMP), oxidized non-regenerated cellulose-based (ONRC - RESORBA CELL), and gelatin-based (GELA - GELITA TUFT-IT) hemostats are commonly used in surgery. However, their impact on the wound healing process remains largely unexplored. We here assess time-dependent effects of exposure to these hemostats on fibroblast-related wound healing processes.

MATERIAL AND METHODS

Hemostats were applied to fibroblast cell cultures for 5-10 (short-), 30 and 60 min (intermediate-) and 24 h (long-term). Representative images of the hemostat degradation process were obtained, and the pH value was measured. Cell viability, apoptosis and migration were analyzed after the above exposure times at 3, 6 and 24 h follow-up. Protein levels for tumor necrosis factor α (TNF-α) and transforming-growth factor β (TGF-β) were assessed.

RESULTS

ORC and ONRC reduced pH values during degradation, while GELA proved to be pH-neutral. Hemostat structural integrity was prolonged for GELA (vs. ORC and ONRC). TGF-β and TNF-α levels were reduced for ORC and ONRC (vs. GELA and control) (p < 0.05). Further, exposure of ORC and ONRC for longer than 5-10 min reduced cell viability vs. GELA and control at 3 h post-exposure (p < 0.05). Similarly, cell migration was impaired with ORC and ONRC exposure longer than 60 min at 24 h follow-up (p < 0.05).

CONCLUSIONS

Short-term exposure to ORC and ONRC impairs relevant wound healing-related processes in fibroblasts, and alters protein levels of key mediating cytokines. GELA does not show similar effects. We conclude that GELA may be preferred over ORC and ONRC over short-, intermediate- and long-term exposures. Future validation of the clinical relevance is warranted.

Gelatin-based hemostatic agents for medical and dental application at a glance: A narrative literature review

Uncontrolled bleeding is linked to higher treatment costs, risk of post-surgical infection and increased disease and death. Hemostatic agents are used to treat excessive bleeding. A good hemostatic agent controls bleeding effectively, reduces the need for blood transfusion, removes the need for systemic drugs to control bleeding, results in shorter surgery time, and reduces the cost and length of hospital stay of the patient. Gelatin-based hemostatic agents have been widely used in medical and dental procedures, owing to their biodegradability and biocompatibility, as well as availability and low cost of raw materials. In this narrative literature review, we discuss the background and different types of gelatin-based hemostatic agents in medical and dental procedures, the comparison of gelatin-based and non-gelatin-based hemostatic agents, and the usage and development of enhanced or novel gelatin-based hemostatic agents. Gelatin-based hemostatic agents are effective and important part of bleeding control, as evidenced by its wide application in medicine and dentistry. The development of novel combination gelatin-based hemostatic agents has much potential for effective control of excessive bleeding.

Endoscopy-assisted resection of a sphenoid-wing meningioma using a 3D-printed patient-specific pointer in a dog: A case report

A 9-year-old female mixed-breed dog presented for treatment of a presumed sphenoid-wing meningioma. Clinical signs included tonic-clonic seizures lasting &lt;1 min, which had started 3 months previously. The physical examination results were unremarkable. An eccentrically located neoplastic cystic structure in the right sphenoid bone region suggestive of a meningioma and peritumoural brain oedema was observed in pre-operative magnetic resonance imaging (MRI). Prior to surgery, a three-dimensional (3D) patient-specific pointer (PSP) was designed using computed tomography (CT) images and computer-aided 3D design software. After a targeted approach and exposure of the lateral part of the right temporal lobe by a craniectomy guided by the 3D-PSP, complete macroscopic piecemeal resection of the meningioma could be performed using endoscopy-assisted brain surgery. Post-operative MRI confirmed complete excision of the tumor. Anticonvulsive therapy was discontinued after 90 days, and the dosage of anticonvulsants was tapered 2 weeks after surgery. At a follow-up examination 225 days post-operatively, recurrence of seizures was not observed, and the absence of tumor recurrence was confirmed by a repeat MRI examination. To the best of our knowledge, this is the first report in veterinary medicine describing a successful resection of a sphenoid-wing meningioma using a 3D-PSP. 3D-PSP-assisted craniectomy may be a surgical option for some canine skull-based tumors, such as sphenoid wing meningiomas.

Recent advances in biopolymer-based hemostatic materials

Hemorrhage is the leading cause of trauma-related deaths, in hospital and pre-hospital settings. Hemostasis is a complex mechanism that involves a cascade of clotting factors and proteins that result in the formation of a strong clot. In certain surgical and emergency situations, hemostatic agents are needed to achieve faster blood coagulation to prevent the patient from experiencing a severe hemorrhagic shock. Therefore, it is critical to consider appropriate materials and designs for hemostatic agents. Many materials have been fabricated as hemostatic agents, including synthetic and naturally derived polymers. However, compared to synthetic polymers, natural polymers or biopolymers, which include polysaccharides and polypeptides, have greater biocompatibility, biodegradability, and processibility. Thus, in this review, we focus on biopolymer-based hemostatic agents of different forms, such as powder, particles, sponges, and hydrogels. Finally, we discuss biopolymer-based hemostats currently in clinical trials and offer insight into next-generation hemostats for clinical translation.

Floseal-induced small bowel obstruction

Floseal is a haemostatic agent designed to augment the body’s natural clotting cascade response. We describe the first case in over a decade, and the first case with intra-operative images of early post-operative small bowel obstruction (SBO) associated with Floseal use in general surgery. A previously well man in his 30s underwent laparoscopic appendicectomy for clinical acute appendicitis. Floseal was applied to the right lateral abdominal wall for haemostasis. He developed a mechanical SBO, with diagnostic laparoscopy confirming a transition point between the caecum and terminal ileum, adherent to the area of the previously applied Floseal. He underwent adhesiolysis and uneventful recovery. We propose Floseal may exacerbate early post-operative inflammation and provide a nidus for early adhesion formation. We recommend removing excess Floseal not incorporated in the haemostatic clot and to consider Floseal as a differential in early post-operative SBO.

Medical Adhesives and Their Role in Laparoscopic Surgery—A Review of Literature

Laparoscopic surgery is undergoing rapid development. Replacing the traditional method of joining cut tissues with sutures or staples could greatly simplify and speed up laparoscopic procedures. This alternative could undoubtedly be adhesives. For decades, scientists have been working on a material to bond tissues together to create the best possible conditions for tissue regeneration. The results of research on tissue adhesives achieved over the past years show comparable treatment effects to traditional methods. Tissue adhesives are a good alternative to surgical sutures in wound closure. This article is a review of the most important groups of tissue adhesives including their properties and possible applications. Recent reports on the development of biological adhesives are also discussed.

VIBe Scale: Validation of the Intraoperative Bleeding Severity Scale by Spine Surgeons

BACKGROUND

The Validated Intraoperative Bleeding Scale (VIBe Scale) was initially validated with surgeons who operate on cardiothoracic, abdominal, and pelvic cavities and fulfilled criteria for a clinician-reported scale. However, there is a need for a tool to aid in intraoperative blood management during spine surgeries. The purpose of the present study was to establish the reliability and consistency of the VIBe Scale as a tool for spine surgeons to assess intraoperative bleeding.

METHODS

Orthopedic (n = 16) and neurological (n = 9) spine surgeons scored videos depicting surgical bleeding and assessed the VIBe Scale's relevance and clarity. Inter- and intraobserver agreement (Kendall's W) were calculated for all surgeons and pooled with responses from the original study to establish agreement across specialties.

RESULTS

All of the spine surgeons indicated that the scale was clinically relevant for evaluating hemostasis and could be implemented in a clinical study. Twenty-two spine surgeons (88%) reported that the scale represents the range of bleeding site sizes and severities expected in their practice. Twenty-four spine surgeons (96%) indicated that the scale would be useful in communicating bleeding severity with other members of the surgical team. Interobserver agreement was acceptable (0.79) for orthopedic specialists, appreciable (0.88) for neurological specialists, and appreciable (0.88) for the combined specialists. Intraobserver agreement was excellent for orthopedic (0.91) and neurological (0.91) spine surgeons and excellent (0.96) for the combined specialists.

CONCLUSIONS

The results highlight the reliability of the VIBe Scale and potential utility for quantifying intraoperative blood loss in spine surgery.

LEVEL OF EVIDENCE: 3

CLINICAL RELEVANCE

The VIBe Scale may be useful for evaluating the efficacy of untested intraoperative hemostatic agents and for comparing the relative efficacy of 2 or more analogous agents. It may also prove useful for intraoperative staff by quantifying ongoing intraoperative blood loss and correlating losses with the potential transfusion and intraoperative hemostatic agent requirements.

Evaluation of the effects of different hemostatic agent applications on mental nerve

PURPOSE

Evaluating the effect of ABS (Ankaferd Blood Stopper^®), Tranexamic Acid (Transamin^®) and Thrombin-Containing Hemostatic Matrix (Floseal^®) on the mental nerve of rats by using histopathologic and immunohistochemical analyses.

MATERIALS AND METHODS

40 Wistar Albino rats were used. Rats were randomly selected into 4 groups as Control (G1), ABS (G2), Tranexamic Acid (G3) and Thrombin-Containing Hemostatic Matrix (G4). In the control group G1, the left mental nerve was exposed and 0.3 ml of sterile saline was applied for 5 min, then closed with suture. In the other three groups, the left mental nerve was exposed and 0.3 ml ABS, Tranexamic Acid and Floseal was applied to groups, respectively. After 5 min, wounds were closed with suture. Immunohistochemical and histopathologic examinations were performed on mental nerves after 28 days.

RESULTS

The total histopathologic and immunohistochemical semiquantitative scores were significantly higher in ABS (G2) compared to Control (G1), Tranexamic Acid (G3) and Thrombin-Containing Hemostatic Matrix (G4) (P < 0.05). Myelin thickness were significantly lower in G2 compared to G1, G2 and G3 (P < 0.05). G3 has the most reliable results compared to G2 and G4 (P < 0.05).

CONCLUSION

The study results suggest that ABS has neurotoxic effects and should not be used close to the nerve, and thrombin-containing hemostatic matrix should be used carefully. Tranexamic acid, on the other hand, was found to be the most reliable hemostatic agent for use in close proximity to neural tissues. Further studies are required to determine the efficacy of the hemostatic agents on peripheral nerve degeneration.

Percutaneous delivery of self-propelling thrombin-containing powder increases survival from non-compressible truncal hemorrhage in a swine model of coagulopathy and hypothermia

BACKGROUND

Non-compressible truncal hemorrhage (NCTH) remains a leading cause of preventable death on the battlefield. Definitively managing severe NCTH requires surgery within the first hour after injury, which is difficult when evacuating casualties from remote and austere environments. During delays to surgery, hemostatic interventions that are performed prehospital can prevent coagulopathy and hemorrhagic shock and increase the likelihood that casualties survive to receive definitive care. We previously reported that a self-propelling thrombin-containing powder (SPTP) can be delivered percutaneously into the abdomen as a minimally invasive intervention and can self-disperse through pooled blood to deliver the hemostatic agents thrombin and tranexamic acid (TXA) locally to noncompressible intracavitary wounds. We hypothesized that in swine with massive NCTH, dilutional coagulopathy and hypothermia, delivering SPTP could extend survival times.

METHODS

Ten swine (n = 5 per group) underwent NCTH from a Grade V liver injury following a midline laparotomy. The laparotomy was closed with sutures afterwards, creating a hemoperitoneum, and animals were managed with crystalloid fluid resuscitation, or crystalloid resuscitation and SPTP. SPTP was delivered into the closed abdomen using a CO2-powered spray device and a catheter placed into the hemoperitoneum, entering through the upper right quadrant using the Seldinger technique. Survival to one and three hours was recorded. In an additional animal, hemorrhage was created laparoscopically and SPTP was imaged in-situ within the abdomen to visually track dispersion of the particles.

RESULTS

SPTP dispersed as far as 35 +/- 5.0 cm within the abdomen. SPTP increased survival to one and three hours (Kaplan-Meier p = 0.007 for both). The median survival time was 61 minutes with SPTP and 31 minutes without (p = 0.016).

CONCLUSION

SPTP effectively disperses medications throughout a hemoperitoneum and increases survival in a model of NCTH. SPTP is a promising strategy for nonsurgical management of NCTH, warranting further testing of its safety and efficacy.

LEVEL OF EVIDENCE

Basic Science, N/A.

Percutaneous delivery of self-propelling hemostatic powder for managing non-compressible abdominal hemorrhage: a proof-of-concept study in swine

INTRODUCTION

Non-compressible intra-abdominal hemorrhage (NCIAH) is a major cause of preventable death on the battlefield and in civilian trauma. Currently, it can only be definitively managed with surgery, as there are limited strategies for controlling ongoing NCIAH in the prehospital environment. We hypothesized that a self-propelling thrombin-containing powder (SPTP) could increase survival in a swine model of NCIAH when delivered percutaneously into the closed abdomen using an engineered spray system.

MATERIALS AND METHODS

Nineteen swine underwent surgical laparotomy followed by a Grade V liver injury that created massive hemorrhage, before closing the abdomen with sutures. Animals either received treatment with standard of care fluid resuscitation (n=9) or the SPTP spray system (n=10), which consisted of a spray device and a 14 Fr catheter. Using the spray system, SPTP was delivered into a hemoperitoneum identified using a focused assessment with sonography in trauma (FAST) exam. Lactated Ringer's solution was administered to all animals to maintain a mean arterial pressure (MAP) of >50 mmHg. The primary outcome was percentage of animals surviving at three hours following injury.

RESULTS

In the swine model of NCIAH, a greater percentage of animals receiving SPTP survived to three hours, although differences were not significant. The SPTP spray system increased the median survival of animals from 1.6 hr in the fluid resuscitation group to 4.3 hr. The SPTP spray system delivered a total mass of 18.5 ± 1.0 g of SPTP. The mean change in intra-abdominal pressure following SPTP delivery was 5.2 ± 1.8 mmHg (mean ± SEM). The intervention time was 6.7 ± 1.7 min. No adverse effects related to the SPTP formulation or the spray system were observed. SPTP was especially beneficial in animals that had either severely elevated lactate concentrations or low mean arterial pressure of <35 mmHg shortly after injury.

CONCLUSIONS

This demonstrates proof-of-concept for use of a new minimally invasive procedure for managing NCIAH, which could extend survival time to enable patients to reach definitive surgical care.

The Efficacy of Thrombin-Gelatin Matrix in Hemostasis for Large Breast Tumor after Vacuum-Assisted Breast Biopsy

Background: Vacuum-assisted breast biopsy (VABB) for benign breast tumor excision is a developing trend in breast surgery. The most common complication of VABB is hematoma. We assessed the efficiency of the thrombin-gelatin matrix (TGM) for hemostasis after VABB. Methods: From December 2013 to June 2017, 147 patients with breast tumors > 2 cm in size were treated with a 7-gauge ultrasound-guided EnCor EnSpire® breast biopsy system. After VABB, the TGM was applied using an iron-tube device. After injection, brief external compression for 15 min and postoperative bandage compression for approximately 12 h were applied. The medical records were reviewed and analyzed for hematoma and acute bleeding at 1 and 3 months after VABB. Results: A total of 72 patients received hemostasis via TGM, and 75 patients received hemostasis by compression. The rates of postoperative acute bleeding in the TGM group were significantly lower than those in the non-TGM group (5.5% vs. 22.7%, p = 0.003). Among patients with hematoma, there was no statistically significant difference between the two groups (25% vs. 26.7%, p = 0.85). Conclusions: This is the first cohort study to apply the TGM hemostatic matrix for post-VABB hemostasis. The TGM hemostatic matrix could be an option for patients with large breast tumors.

The effect of local injection of tranexamic acid into peri-articular tissue versus drain clamping in total knee arthroplasty: a randomized controlled trial

Background

Tranexamic acid (TXA) is used as a synthetic anti-fibrinolytic agent for total knee arthroplasty (TKA) to reduce postoperative bleeding. Though the effects on bleeding reduction of several methods of administering TXA have been demonstrated, the optimal method remains controversial. Recently, the hemostatic effect of periarticular local injection of TXA during TKA was reported. Although this method can be expected to suppress postoperative bleeding without placing a drain, its hemostatic effect has not yet been assessed in comparison with local injection and other methods of administering TXA. The aim of this randomized, prospective study was to assess the efficacy of local injection of TXA during TKA.

Methods

To confirm the effect of the local injection of TXA, drain clamping was set as the control. The subjects included a prospective series of 109 patients randomly divided into 2 groups: the local injection (group L) and the drain clamping (group D). The main outcome measure was postoperative bleeding. Secondary outcomes included pain, physical measurements, and laboratory findings.

Results

The calculated total blood loss (CTBL) in groups L and D was nearly equal and did not show the non-inferiority of group L to group D (883 ± 248 vs. 841 ± 257 ml, P = .564). Drained blood loss was significantly higher in group L than in group D (395 ± 130 vs 276 ± 78.8 ml, P < .0001). There was no significant difference in hidden blood loss between the groups (488 ± 269 vs 565 ± 261 ml, P = .131). The other laboratory findings and physical measurements were identical between the groups.

Conclusions

Although CTBL in group L did not show non-inferiority to group D, the local injection of TXA was considered to be superior for suppressing bleeding considering the risk of the adverse effects of using a drain.

Trial registration

This was a randomized, prospective study registered with UMIN Clinical Trials Registry (Registration number: UMIN000036146, date of disclosure: 10/3/2019).

MRI appearance of adjunct surgical material used in spine surgery

BACKGROUND CONTEXT

Early postoperative MR images are frequently necessary after spine surgery. The appearance of commonly used adjunct hemostatic agents and dural sealants in MR images has not been systematically evaluated.

PURPOSE

The purpose of this experimental study was to systematically analyze and describe the characteristics of the most commonly applied hemostatic agents and dural sealants in spine surgery on early postoperative MR images.

STUDY DESIGN

Cadaver Study METHODS: Four commonly applied dural sealants (Duraseal, Bioglue, Tachosil, Tisseel) and five commonly used hemostatic agents (Surgiflo, Bonewax, , Spongostan, Gelfoam, Avitene) were investigated. The experimental setting involved a human cadaver where a standard left-sided laminotomy was performed on nine levels of the thoracolumbar spine, and the materials were separately applied and mixed with fresh blood or water for hemostatic and dural sealants, respectively. The cadaver model was scanned at a 3 Tesla MRI and the imaging findings for all materials were compared to the surrounding tissue and systematically reported.

RESULTS

All investigated dural sealants and hemostatic agents were distinguishable from the surrounding tissue on MR images with different appearances on the MR sequences. A detailed atlas for the identification of the materials in postoperative spine MRI was established.

CONCLUSION

Commonly used hemostatic agents and dural sealants can be successfully identified on early postoperative spine MRI.

CLINICAL SIGNIFICANCE

Knowledge about MRI appearances of commonly used adjunct surgical materials helps in interpretation of postoperative imaging and supports clinical decision making.

Hemostatic biomaterials to halt non-compressible hemorrhage

Non-compressible hemorrhage is an unmet clinical challenge, which occurs in inaccessible sites in the body where compression cannot be applied to stop bleeding. Current treatments reliant on blood transfusion are...

Polymeric Materials for Hemostatic Wound Healing

Hemorrhage is one of the greatest threats to life on the battlefield, accounting for 50% of total deaths. Nearly 86% of combat deaths occur within the first 30 min after wounding. While external wound injuries can be treated mostly using visual inspection, abdominal or internal hemorrhages are more challenging to treat with regular hemostatic dressings because of deep wounds and points of injury that cannot be located properly. The need to treat trauma wounds from limbs, abdomen, liver, stomach, colon, spleen, arterial, venous, and/or parenchymal hemorrhage accompanied by severe bleeding requires an immediate solution that the first responders can apply to reduce rapid exsanguinations from external wounds, including in military operations. This necessitates the development of a unique, easy-to-use, FDA-approved hemostatic treatment that can deliver the agent in less than 30 s and stop bleeding within the first 1 to 2 min at the point of injury without application of manual pressure on the wounded area.

Safety and efficacy of sFilm-FS, a novel biodegradable fibrin sealant, in Göttingen minipigs

Bleeding during surgical procedures is a common complication. Therefore, hemostatic agents have been developed to control bleeding, and fibrin sealants have several benefits. sFilm-FS is a novel fibrin sealant that comprises a biodegradable co-polymeric film embedded with human fibrinogen and thrombin. Herein, the safety and efficacy of sFilm-FS were compared using a liver and spleen puncture model of Göttingen minipigs with those of the standard hemostatic techniques (control animals) and EVARREST^®, a reference fibrin sealant. Hemostasis and reduced blood loss were more effectively achieved with sFilm-FS than with the standard techniques in the control animals and comparable to those achieved with EVARREST^®. No treatment-related adverse effects were observed in any of the groups. Histopathological evaluation indicated that sFilm-FS was slightly and moderately reactive at the liver puncture site and spleen, respectively, compared with the standard techniques in the control animals. These changes are expected degradation reactions of the co-polymeric film and are not considered as adverse events. No treatment-related abnormalities were noted in the other evaluated organs. Additionally, no evidence of local or systemic thromboses was noted. These results support the use of sFilm-FS for hemostasis in humans.

Efficacy and Safety of a Thrombin-Containing Collagen-Based Hemostatic Agent in Spinal Surgery: A Randomized Clinical Trial

OBJECTIVE

When common hemostatic methods, such as suturing, cautery, and compression, fail to arrest bleeding during surgery, various local hemostatic agents are used. We aimed to evaluate the hemostatic efficacy and safety of CollaStat (Dalim Tissen Co. Ltd., Seoul, Korea), a novel thrombin-containing, collagen-based topical haemostatic agent used in spinal surgery, by comparing it with Floseal (Baxter Healthcare, Deerfield, Illinois, USA).

METHODS

We performed a randomized controlled trial in 78 patients who underwent spinal surgery. The participants were randomly assigned to either an intervention group (use of CollaStat) or a control group (use of Floseal). We compared successful haemostasis rate, time to hemostasis, length of hospital stay, amount of fluid drainage, and rate of adverse events between the 2 groups.

RESULTS

The hemostasis success rate was 94.87% in the intervention group and 97.44% in the control group. The hemostatic efficacy and safety of CollaStat were found to be noninferior to those of Floseal since the higher limit (11.09%) of the confidence interval (CI) for the difference with Floseal was greater than the prespecified noninferiority margin of -13%. There were no statistically significant differences at the 5% level in hemostasis time, number of hemostatic agents used, hospitalization period, and amount of drainage between the 2 groups. Also, there was no incidence of medical device-related serious adverse events or adverse events in both groups.

CONCLUSIONS

The hemostatic efficacy and safety of CollaStat were found to be noninferior to those of Floseal. Therefore CollaStat can be safely and effectively used in spinal surgery.

Use of Gelatin-thrombin Hemostatic Matrix for Control of Ruptured Cerebral Aneurysm

BACKGROUND

 The use of thrombin-based hemostatic agents (TBHAs) has become common practice in most neurosurgical procedures, both cranial and spinal.

METHODS

 We present the case of a 40-year-old woman who was referred to our institution with intense headache and Fisher grade 3 subarachnoid hemorrhage (SAH) mainly at the level of the right sylvian fissure, caused by a 5.71-mm right middle cerebral artery (MCA) bifurcation aneurysm, with hourglass morphology and a bleb on the bottom. Cerebral angiography demonstrated aneurysm enlargement, compared with the prior angiographic computerized tomography scan.

RESULTS

 A right pterional craniotomy was performed. After initial arachnoid dissection to get proximal vascular control, but before we obtained it, we witnessed profuse bleeding from the aneurysm. Floseal, a gelatin-thrombin matrix sealant, was sprayed over the breach of the aneurysm, and cottonoids were gently pressed with a self-retaining spatula, stopping the hemorrhage. After that, we obtained proximal control with an extradural clinoidectomy and temporary clipping of the right internal carotid artery (ICA) and MCA. Finally, aneurysm dissection and final clipping were performed with the application of two clips. The postoperative course was uneventful, and the patient was discharged on postoperative day 10.

CONCLUSION

 Intraoperative aneurysm rupture (IAR) is a dangerous event that carries great risks-even death. Proper use of TBHAs is a useful and safe way to stop the bleeding, take a deep breath, and achieve proximal vascular control. To the best of our knowledge, this is the first report of the use of TBHA during aneurysm clipping.

A novel predictive model of intraoperative blood loss in patients undergoing elective lumbar surgery for degenerative pathologies

BACKGROUND CONTEXT

Intraoperative blood loss (IOBL) is unavoidable during surgery; however, high IOBL is associated with increased morbidity and increased risk for requiring allogenic blood transfusion, itself associated with poorer outcomes.

PURPOSE

Here we sought to develop and validate a predictive calculator for IOBL that could be used by surgeons to estimate likely blood loss.

STUDY DESIGN/SETTING

Retrospective cohort.

PATIENT SAMPLE

Series of consecutive patients who underwent elective lumbar spine surgery for degenerative pathologies over a 27-month period at a single tertiary care center.

OUTCOME MEASURES

Primary outcome was IOBL. Secondary outcome was the occurrence of "major intraoperative bleeding," defined as IOBL exceeding 1 L.

METHODS

Charts of included patients were reviewed for medical comorbidities, preoperative laboratory data, surgical plan, and anesthesia records. Univariate linear regressions were performed to find significant predictors of IOBL, which were then subjected to a multivariate analysis to identify the final model. Model training was performed using 70% of the included cohort and external validation was performed using 30% of the cohort. Results of the model were deployed as a freely available online calculator.

RESULTS

We identified 1,281 patients who met inclusion/exclusion criteria. Mean age was 60±15 years, mean Charlson Comorbidity score was 1.1±1.6, and 51.8% were male. There were no significant differences between the training and validation cohorts with regard to any of the demographic variables or intraoperative variables; tranexamic acid use and surgical invasiveness were also similar in both cohorts. Multivariate analysis identified body mass index (βₙ=7.14; 95% confidence interval [3.15, 11.13]; p<.001), surgical invasiveness (βₙ=29.18; [24.62, 33.74]; p<.001), tranexamic acid use (βₙ=-0.093; [-0.171, -0.014]; p=.02), and surgical duration (βₙ=2.13; [1.75, 2.51]; p<.001) as significant predictors of IOBL. The model had an overall fit of r=0.693 in the validation cohort. Construction of a receiver-operating curve for predicting major IOBL showed a C-statistic of 0.895 within the validation cohort.

CONCLUSION

Here we identify and validate a model for predicting IOBL in patients undergoing lumbar spine surgery. The model was a moderately strong predictor of absolute IOBL and was demonstrated to predict the occurrence of major IOBL with a high degree of accuracy. We propose it may have future utility when counseling patients about surgical morbidity and the probability of requiring transfusion.

Efficacy and safety of regenerated cellulose topical gauze haemostats in managing secondary haemostasis: a randomised control trial

OBJECTIVE

To compare the efficacy and safety of HemoStyp (United Health Products, US), a neutralised oxidised regenerated cellulose (NORC) and Surgicel (Johnson & Johnson, US), an oxidised regenerated cellulose (ORC), in the management of bleeding of surgical wounds during abdominal, thoracic and vascular surgeries.

METHOD

This study was a prospective, non-inferiority, multicentre, randomised, open-label trial. Surgical procedures were performed according to expected standard of care and in compliance with all relevant laws and institutional guidelines. Patients who developed Lewis Bleeding Scale grade 1 and grade 2 bleeds not controlled through conventional techniques were randomised to either the NORC or ORC treatment arms. Bleeding was measured every 30 seconds after treatment, ending at five minutes after haemostasis was achieved or at 10 minutes if haemostasis was not achieved.

RESULTS

A total of 236 patients were included in the study. There was a total of seven adverse events in the study, none of which had causality related to either the NORC or ORC. For all surgical procedures, haemostasis was achieved more quickly with the NORC than the ORC (p<0.0001). In addition, haemostasis for all patients was achieved in under two minutes for the NORC compared with 81% of patients in the ORC groups. For Lewis Bleeding Scale grade 1 bleeds, the median time to control bleeding was 24 seconds in the NORC group and 51 seconds for the ORC group. For grade 2 bleeds, time to control bleeding was 76 seconds and 116 seconds, respectively.

CONCLUSION

For patients in this study, haemostasis was achieved more quickly in the NORC treatment group compared with the ORC group, in patients with Lewis grade 1 or 2 bleeds caused by surgical wounds generated during abdominal, thoracic and vascular surgeries.

Advances in Topical Hemostatic Agent Therapies: A Comprehensive Update

Severe hemorrhage causes significant metabolic and cellular dysfunction secondary to deficient tissue perfusion and oxygen delivery. If bleeding continues, hemodynamic destabilization, hypoxemia, multiple organ failure, and death will occur. Techniques employed to promote hemostasis include surgical suture ligatures, cautery, chemical agents, self-assembling nanoparticles, and physical methods, like mechanical pressure. Improved understanding of the natural clotting cascade has allowed newly designed agents to become more targeted for clinical and military use. Topically-applied hemostatic agents have enormous clinical applications in achieving hemostasis. This manuscript describes currently available and developing topical hemostatic materials, including topical active agents, mechanical agents, synthetic/hemisynthetic hemostatic agents, and external hemostatic dressings for clinical practice.

Effectiveness of Gelatin-Thrombin Matrix Sealants (Floseal®) on Postoperative Spinal Epidural Hematoma during Single-Level Lumbar Decompression Using Biportal Endoscopic Spine Surgery: Clinical and Magnetic Resonance Image Study

Background

Symptomatic postoperative spinal epidural hematoma (PSEH) is a devastating complication that could develop after lumbar decompression surgery. PSEH can also develop after biportal endoscopic spine surgery (BESS), one of the recently introduced minimally invasive spine surgery techniques. Gelatin-thrombin matrix sealant (GTMS) is commonly used to prevent PSEH. This study aimed at analyzing the clinical and radiological effects of GTMS use during BESS.

Methods

A total of 206 patients with spinal stenosis who underwent decompression by BESS through a posterior interlaminar approach from October 2015 to September 2018 were enrolled in this study. Postoperative magnetic resonance imaging (MRI) was performed in all patients for evaluation of PSEH. Patients in whom GTMS was not used during surgery were assigned to Group A, and those in whom GTMS was used were classified as Group B. In the clinical evaluation, the visual analog scale (VAS) of the leg and back, Oswestry Disability Index (ODI), and modified MacNab criteria were used. The incidence rate and degree of dural compression of PSEH on postoperative MRI were measured.

Results

The average age of the patients was 68.1 ± 11.2 (42–89) years. The overall incidence rate of PSEH was 20.9% (43/206). The incidence rates in Groups A and B were 26.4% and 13.6%, respectively, showing a significant difference (p = 0.023). The VAS-leg and ODI improvement was significantly different depending on the intraoperative use of GTMS. However, there was no statistically significant difference between the two groups in terms of the VAS-back improvement. Groups A and B showed “good” and “excellent” rates according to the modified MacNab criteria in 79.4% and 87.6% of patients, respectively, showing statistically significant difference (p = 0.049). In Group A, two patients underwent revision surgery due to PSEH, while none in Group B had such event.

Conclusion

Intraoperative use of GTMS during BESS may be related to reduction in the occurrence rate of PSEH. Specifically, patients with GTMS appliance showed marked decrease in the occurrence of PSEH and had better clinical outcomes.

Use of hemostatic agents for surgical bleeding in laparoscopic partial nephrectomy: Biomaterials perspective

In recent years, there was an abrupt increase in the incidence of renal tumors, which prompt up the appearance of cutting-edge technology, including minimally invasive and organ-preserving approaches, such as laparoscopic partial nephrectomy (LPN). LPN is an innovative technique used to treat small renal masses that have been gaining popularity in the last few decades due to its promissory results. However, the bleeding control remains the main challenge since the majority of currently available hemostatic agents (HAs) used in other surgical specialities are inefficient in LPN. This hurried the search for effective HAs adapted for LPN surgical peculiarities, which resulted on the emergence of different types of topical HAs. The most promising are the natural origin HAs because of their inherent biodegradability, biocompatibility, and lowest toxicity. These properties turn them top interests' candidates as HAs in LPN. In this review, we present a deep overview on the progress achieved in the design of HAs based on natural origin polymers, highlighting their distinguishable characteristics and providing a clear understanding of their hemostat's role in LPN. This way it may be possible to establish a structure-composition properties relation, so that novel HAs for LPN can be designed to explore current unmet medical needs.

Valutazione dell’utilizzo di Floseal®, un agente emostatico topico, in chirurgia cardiotoracica

Introduction:

Achieving haemostasis is critical in surgical procedures. Surgical bleeding is associated with an increased risk of mortality and morbidity with consequences at both clinical and organizational level, and with significant economic implications. In addition to conventional methods for controlling intraoperative bleeding, many topical adjunctive hemostatic products are available; among them Floseal® (Baxter Healthcare Corporation), a gelatin-based hemostatic matrix.

The aim of this study is to provide an updated systematic literature review of Floseal® in cardiac surgery and estimate its associated economic impact in an Italian hospital.

Methods:

A literature search was conducted in MEDLINE and the Cochrane Library over the period 2013-2016 to identify new publications related to Floseal® in cardiac surgery, in addition to those already included in the systematic review of Echave et al. Furthermore, we investigated the economic impact of the use of Floseal® adapting the model elaborated by Tackett et al. to the Italian NHS. Four new studies were selected.

Results:

High variability in surgical procedures, choice of hemostatic products compared to Floseal® and outcome definition is confirmed. Clinical, organizational, and economics endpoints were investigated. A cost-consequence analysis estimated relevant savings. A scenario analysis, despite showing a high variability in patient level savings (€ 441-2.831), confirmed economic advantages associated with Floseal®.

Discussion:

Results support prior research both in terms of heterogeneity of evidence on the effectiveness of Floseal® in cardiac surgery and cost implications. The use of Floseal® achieves substantial cost savings in a hypothetical Italian hospital with a cardiac surgery unit.

Three-dimensional (3D) brain microphysiological system for organophosphates and neurochemical agent toxicity screening

We investigated a potential use of a 3D tetraculture brain microphysiological system (BMPS) for neurotoxic chemical agent screening. This platform consists of neuronal tissue with extracellular matrix (ECM)-embedded neuroblastoma cells, microglia, and astrocytes, and vascular tissue with dynamic flow and membrane-free culture of the endothelial layer. We tested the broader applicability of this model, focusing on organophosphates (OPs) Malathion (MT), Parathion (PT), and Chlorpyrifos (CPF), and chemicals that interact with GABA and/or opioid receptor systems, including Muscimol (MUS), Dextromethorphan (DXM), and Ethanol (EtOH). We validated the BMPS platform by measuring the neurotoxic effects on barrier integrity, acetylcholinesterase (AChE) inhibition, viability, and residual OP concentration. The results show that OPs penetrated the model blood brain barrier (BBB) and inhibited AChE activity. DXM, MUS, and EtOH also penetrated the BBB and induced moderate toxicity. The results correlate well with available in vivo data. In addition, simulation results from an in silico physiologically-based pharmacokinetic/pharmacodynamic (PBPK/PD) model that we generated show good agreement with in vivo and in vitro data. In conclusion, this paper demonstrates the potential utility of a membrane-free tetraculture BMPS that can recapitulate brain complexity as a cost-effective alternative to animal models.

Topical biomaterials to prevent post-tonsillectomy hemorrhage

Despite advances in surgical technique, postoperative hemorrhage remains a common cause of mortality and morbidity for patients following tonsillectomy. Application of biomaterials at the time of tonsillectomy can potentially accelerate mucosal wound healing and eliminate the risk of post-tonsillectomy hemorrhage (PTH). To understand the current state and identify possible routes for the development of the ideal biomaterials to prevent PTH, topical biomaterials for eliminating the risk of PTH were reviewed. Alternative topical biomaterials that hold the potential to reduce the risk of PTH were also summarized.

Evaluation of a novel collagen hemostatic matrix in a porcine heart and cardiac vessel injury model

Background

Flowable hemostatic agents may be more advantageous than nonflowable hemostats, as they have capability to cover irregular wound surfaces, fill deep lesions, and easily remove excess materials with irrigation. In this study, we evaluated the hemostatic efficacy of the collagen hemostatic matrix (CHM) compared to FloSeal^® via incisions in the heart and cardiac vessels in a porcine model.

Methods

In each of the two female pigs, a total of two incisions were made in seven locations: right atrium (RA), right ventricle (RV), and cardiac vessels, such as the innominate vein (IV), superior vena cava (SVC), pulmonary artery (PA), coronary artery (CA), and aorta. Hemostatic agents were applied directly to the bleeding wounds. In certain location, one incision was treated with the CHM and the other with FloSeal^®, and the time to hemostasis and the degree of bleeding of the two agents were assessed and compared. One week after surgery, the animals were sacrificed, and specimens were collected for histologic evaluation.

Results

Bleeding from the vessels with relatively low pressure (the IV, SVC, and RA) was controlled within 1-2 minutes using both a CHM and FloSeal^®. Bleeding from the vessels with high blood pressure (the RV, PA, CA, and aorta) was controlled within 3-10 minutes with the CHM. However, hemostasis in the PA and CA was not achieved with FloSeal^®. Histological analysis revealed that the use of both the CHM and FloSeal^® resulted in foreign body reactions of similar severity.

Conclusions

The hemostatic effect and safety of the CHM may be similar to that of FloSeal^®. Further clinical studies must be conducted to validate our results.

Effects of Combined Use of Ultrasonic Bone Scalpel and Hemostatic Matrix on Perioperative Blood Loss and Surgical Duration in Degenerative Thoracolumbar Spine Surgery

How to decrease intraoperative bleeding, shorten surgical time, and increase safety in spinal surgery is an important issue. Ultrasonic bone removers and FloSeal have been proven to increase safety, reduce the surgical duration, and decrease intraoperative bleeding in skull base surgery. Therefore, we aimed to compare the surgical duration, blood loss, and complications during spinal surgery with or without the use of FloSeal and an ultrasonic bone scalpel. Therefore, we retrospectively reviewed 293 patients who underwent thoracolumbar spinal surgery with decompression and instrumented fusion performed by a single surgeon. We divided these patients into three groups, including nonuse of FloSeal nor a bone scalpel (group A), use of FloSeal only (group B), and use of FloSeal and a bone scalpel (group C) intraoperatively after pairing in terms of age, sex, and surgical level. The surgical duration, blood loss, and occurrence of complications were all recorded. The mean surgical duration in group A was 160 mins, in group B it was 167 mins, and in group C it was 134 mins. The mean blood loss was 700 ml in group A, 682 ml in group B, and 383 ml in group C. Six patients sustained intraoperative dura injuries in total, 3 in group A, 2 in group B, and 1 in group C. No postoperative neurologic defects or occurrences of hematoma were recorded. According to our results, we concluded that combined use of FloSeal and bone scalpels is recommended during primary thoracolumbar spinal surgery to reduce the intraoperative blood loss and shorten the surgical duration.

An Efficacy Comparison of Two Hemostatic Agents in a Porcine Liver Bleeding Model: Gelatin/Thrombin Flowable Matrix versus Collagen/Thrombin Powder

Purpose: Management of bleeding during surgery can be aided by the application of topical hemostatic agents. This study compared the hemostatic efficacy of a new powder agent containing collagen, chondroitin sulfate, and thrombin (PCCT) with a flowable gelatin-thrombin matrix with smooth particles (SmGM) in a porcine liver bleeding model. Materials and Methods: Lesions 4-6 mm deep and ∼10 mm in diameter were created in porcine livers and treated with either SmGM or PCCT. Bleeding rate and grade were quantified before and 3, 7, and 11 minutes after treatment. Results: Thirty-two lesions each were treated with SmGM or PCCT; the median (Q1, Q3) initial bleeding rate was comparable between the two groups (8.43 [6.18, 10.68] g/min and 7.15 [5.16, 9.63] g/min, respectively). The residual bleeding rate was significantly lower at all time-points post treatment for SmGM compared with PCCT (3 minutes: 0.14 [0.07, 0.21] versus 0.46 [0.20, 1.20] g/min, p < 0.0001; 7 minutes: 0.07 [0.04, 0.11] versus 0.12 [0.08, 0.39] g/min, p = 0.001; 11 minutes: 0.05 [0.03, 0.08] versus 0.07 [0.05, 0.12] g/min, p = 0.043). Bleeding grade at 3 minutes was also significantly lower for SmGM compared with PCCT (median [Q1, Q3] 0.0 [0.0, 0.0] versus 1.0 [1.0, 2.0], p < 0.0001). PCCT required reapplication in approximately one-third of applications due to insufficient hemostasis 4 minutes after initial application and showed a tendency to stick to the wet gauze during approximation. Conclusions: In this bleeding model, treatment with SmGM resulted in reduced blood loss, no need for reapplication and was easier to apply compared with PCCT.