Acute in-vivo evaluation of bleeding with GelfoamTM plus saline and Gelfoam plus human thrombin using a liver square lesion model in swine

Coagulant Protein-Free Blood Coagulation Using Catechol-Conjugated Adhesive Chitosan/Gelatin Double Layer

Since the discovery of polyphenolic underwater adhesion in marine mussels, researchers strive to emulate this natural phenomenon in the development of adhesive hemostatic materials. In this study, bio-inspired hemostatic materials that lead to pseudo-active blood coagulation, utilizing traditionally passive polymer matrices of chitosan and gelatin are developed. The two-layer configuration, consisting of a thin, blood-clotting catechol-conjugated chitosan (CHI-C) layer and a thick, barrier-functioning gelatin (Geln) ad-layer, maximizes hemostatic capability and usability. The unique combination of coagulant protein-free condition with CHI-C showcases not only coagulopathy-independent blood clotting properties (efficacy) but also exceptional clinical potential, meeting all necessary biocompatibility evaluation (safety) without inclusion of conventional coagulation triggering proteins such as thrombin or fibrinogen. As a result, the CHI-C/Geln is approved by the Ministry of Food and Drug Safety (MFDS, Republic of Korea) as a class II medical device. Hemostatic efficacy observed in multiple animal models further demonstrates the superiority of CHI-C/Geln sponges in achieving quick hemostasis compared to standard treatments. This study not only enriches the growing body of research on mussel-inspired materials but also emphasizes the potential of biomimicry in developing advanced medical materials, contributing a promising avenue toward development of readily accessible and affordable hemostatic materials.

Evaluation of the validated intraoperative bleeding scale in liver surgery: study protocol for a multicenter prospective study

Background

Surgical hemostasis has become one of the key principles in the advancement of surgery. Hemostatic agents are commonly administered in many surgical specialties, although the lack of consensus on the definition of intraoperative bleeding or of a standardized system for its classification means that often the most suitable agent is not selected. The recommendations of international organizations highlight the need for a bleeding severity scale, validated in clinical studies, that would allow the selection of the best hemostatic agent in each case. The primary objective of this study is to evaluate the VIBe scale (Validated Intraoperative Bleeding Scale) in humans. Secondary objectives are to evaluate the scale's usefulness in liver surgery; to determine the relationship between the extent of bleeding and the hemostatic agent used; and to assess the relationship between the grade of bleeding and postoperative complications.

Methods

Prospective multicenter observational study including 259 liver resections that meet the inclusion criteria: patients scheduled for liver surgery at one of 10 medium-high volume Spanish HPB centers using an open or minimally invasive approach (robotic/laparoscopic/hybrid), regardless of diagnosis, ASA score <4, age ≥18, and who provide signed informed consent during the study period (September 2023 until the required sample size has been recruited). The participating researchers will be responsible for collecting the data and for reporting them to the study coordinators.

Discussion

This study will allow us to evaluate the VIBe scale for intraoperative bleeding in humans, with a view to its subsequent incorporation in daily clinical practice.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT05369988?term = serradilla&draw = 2&rank = 3, [NCT0536998].

Effectiveness of Hemopatch® versus Surgicel® Original to control mild and moderate liver bleeding

Background

Adjunct hemostats can be of use in certain surgical settings. We compared the effectiveness of two hemostats, Hemopatch® and Surgicel® Original in controlling bleeding from liver lesions in an experimental model.

Methods

Control of grades 1 (mild) and 2 (moderate) bleeding (according to the Validated Intraoperative Bleeding [VIBe] SCALE) was assessed for 10 min after Hemopatch® (n = 198) or Surgicel® Original (n = 199) application on 397 liver surface lesions. The primary endpoint was hemostatic success (reaching VIBe SCALE grade 0 at 10 min). The secondary endpoint was time to hemostasis (time to reach and maintain grade 0). A generalized linear mixed model and an accelerated failure time model were used to assess the primary and secondary endpoints, respectively.

Results

The overall hemostatic success rate of Hemopatch® was statistically significantly superior to that of Surgicel® Original (83.8% versus 73.4%; p = 0.0036; odds ratio [OR] 2.38, 95% confidence interval [CI] 1.33–4.27) and time to hemostasis was reduced by 15.9% (p = 0.0032; 95% CI 0.749–0.944). Grade 2 bleeds treated with Hemopatch® had statistically significantly higher hemostatic success (71.7% versus 48.5%; p = 0.0007; OR 2.97, 95% CI 1.58–5.58) and shorter time to hemostasis (49.6% reduction, p = 3.6 × 10^–8); differences for grade 1 bleeds (hemostatic success rate or time to hemostasis) were not statistically significant.

Conclusions

Hemopatch® provided better control of VIBe SCALE bleeding compared to Surgicel® Original for Grade 2 bleeds in this porcine model, highlighting the importance of choosing a suitable hemostat to optimize control of bleeding during surgery.

Applicability and reproducibility of the validated intraoperative bleeding severity scale (VIBe scale) in liver surgery: A multicenter study

BACKGROUND

Bleeding is an intraoperative and postoperative complication of liver surgery of concern, and yet evidence to support utility and reproducibility of bleeding scales for liver surgery is limited. We determined the reproducibility of the clinician-reported validated intraoperative bleeding severity scale and its clinical value of implementation in liver surgery.

METHODS

In this descriptive and observational multicenter study, we assessed the performance of liver surgeons instructed on the clinician-reported intraoperative bleeding severity scale using training videos that covered all 5 grades of bleeding severity. Surgeons were stratified according to years of surgical experience and number of surgeries performed per year based on a median split in low and high values. Intraobserver and interobserver agreement was assessed using Kendall's coefficient of concordance (Kendall's W).

RESULTS

Forty-seven surgeons from 10 hospitals in Spain participated in the study. The overall intraobserver concordance was 0.985, and the overall interobserver concordance was 0.929. For "high experience" surgeons, the intraobserver and interobserver agreement values were 0.990 and 0.941, respectively. For "low experience" surgeons, the intraobserver and interobserver agreement was 0.981 and 0.922, respectively. Regarding the annual number of surgeries, intraobserver and interobserver agreement values were 0.995 and 0.940, respectively, for surgeons performing >35 surgeries per year, with 0.979 and 0.923, respectively, for surgeons who perform ≤35 surgeries year.

CONCLUSION

The clinician-reported intraoperative bleeding severity scale shows high interobserver and intraobserver concordance, suggesting it is a useful tool for assessing severity of bleeding during liver surgery; years of surgical experience and number of annual procedures performed did not affect the applicability of the clinician-reported intraoperative bleeding severity scale.

Comparison of hemostatic efficacy of topical Ankaferd Blood Stopper on heparinized and nonheparinized rats in bleeding related to liver injury

PURPOSE

In this study, hemostatic efficacy of Ankaferd Blood Stopper (ABS), a new generation hemostatic agent, was compared in the presence of heparin effect.

METHODS

Forty-eight Wistar albino rats were divided into two main groups as heparinized and nonheparinized, and these two main groupswere divided into six subgroups as control, Surgicel and ABS (n = 8). Grade 2 liver injury was performed on rats as standard. All groups were compared in terms of weight, laceration surface area, prothrombin time (PT), activated partial thromboplastin time (aPTT), international normalized ratio (INR), bleeding time, bleeding amount, hemoglobin (Hb) levels, macroscopic and microscopic reactions to the agent used.

RESULTS

Whereas there was no statistically significant difference between weight, laceration surface area, PT, INR and preoperative Hb values in the heparinized and nonheparinized groups, postoperative Hb, bleeding time, bleeding amount and aPTT values were statistically different (p < 0.05). In the heparin-hemostat interaction, the ABS group had the lowest bleeding in the heparinized group in terms of the amount of bleeding compared to the control and Surgicel groups (F = 0.764; p = 0.047). In macroscopic and microscopic comparison, there was no difference between the groups in terms of cell necrosis andfresh bleeding (p > 0.05), it was found that the Surgicel group had statistical significantly higher reaction scores (p < 0.05) than the other groups in terms of other parameters.

CONCLUSIONS

Ankaferd Blood Stopper can be safely and effectively used in surgical practice and in patients with additional diseases requiring heparinization, since it causes minimal reaction in the liver and decreases the amount of bleeding especially in the heparinized group.

Dual inhibition of factor XIIa and factor XIa as a therapeutic approach for safe thromboprotection

Clinical practice shows that a critical unmet need in the field of medical device-associated thrombosis prevention is the availability of an anticoagulant therapy without hemorrhagic risk. In the quest for new drugs that are at least as effective as those currently available, while avoiding bleeding complications, molecules that target nearly every step of the coagulation pathway have been developed. Among these molecules, inhibitors of factor XII (FXII) or factor XI (FXI) are promising alternatives as deficiencies in these factors protect against thrombosis without causing spontaneous hemorrhage, as revealed by epidemiological and preclinical data. Ixodes ricinus-contact phase inhibitor (Ir-CPI), a new anticoagulant candidate with an innovative mechanism of action could be this ideal anticoagulant agent for safe prevention from clotting on medical devices. This protein, which selectively binds to FXIIa, FXIa, and plasma kallikrein and inhibits the reciprocal activation of FXII, prekallikrein, and FXI in human plasma, was shown to prevent thrombosis in an ovine cardiopulmonary bypass system associated with cardiac surgeries. Furthermore, as opposed to unfractionated heparin, Ir-CPI appears to be devoid of bleeding risk. This review outlines the rationale for targeting upstream coagulation factors in order to prevent medical device-associated thrombosis; examines the novel approaches under development; and focuses on Ir-CPI, which shows promising properties in the field of thrombosis prevention.

Comparison of the efficacy of five standard topical hemostats: a study in porcine liver and spleen models of surgical bleeding

Background

Several topical hemostats are available to help control surgical bleeding. Cutanplast is a highly absorbent and porous gelatin product that is available in Fast sponge and powder forms. This study investigated the hemostatic efficacy of Cutanplast Standard and Fast gelatin sponge and powder and Emosist oxidized regenerated cellulose (ORC) gauze in porcine liver and spleen surgical bleeding models.

Methods

Cutanplast Standard and Fast gelatin sponge and Emosist ORC gauze were tested in liver abrasion/incision, liver puncture and spleen incision/puncture injuries, and Cutanplast Standard and Fast gelatin powder products were tested in liver abrasion/incision injuries. There were 13 liver injury (five abrasion, five incision and three puncture) and six spleen injury (three puncture and three incision sites) sites per animal.

Results

Rapid hemostasis (≤ 2–5 min) was achieved in the liver abrasion and incision models with all Cutanplast gelatin sponge and powder products and Emosist ORC gauze, except in the liver incision model, time to hemostasis was > 5 min with Cutanplast Standard gelatin powder and Emosist ORC gauze. Rapid hemostasis occurred with Cutanplast Fast gelatin sponge and Emosist ORC gauze in the liver puncture and spleen puncture and incision models. In the spleen incision model, Cutanplast Standard gelatin sponge had a time to hemostasis approaching 10 min.

Conclusion

Cutanplast gelatin sponge and powder products and Emosist ORC gauze may be suitable for surgical applications involving parenchymal organ bleeding, but certain products may perform better than others, including Cutanplast gelatin powder in diffuse mild bleeding (such as liver abrasion), and Cutanplast Fast gelatin sponge and Emosist ORC gauze for splenic bleeding.

SPOT GRADE II: Clinical Validation of a New Method for Reproducibly Quantifying Surgical Wound Bleeding: Prospective, Multicenter, Multispecialty, Single-Arm Study

The SPOT GRADE (SG), a Surface Bleeding Severity Scale, is a unique visual method for assessing bleeding severity based on quantitative determinations of blood flow. This study assessed the reliability of the SG scale in a clinical setting and collected initial data on the safety and efficacy of HEMOBLAST Bellows (HB), a hemostatic agent, in abdominal and orthopedic operations. Twenty-seven patients were enrolled across 3 centers and received the investigational device. Bleeding severity and hemostasis were independently assessed by 2 surgical investigators at baseline and at 3, 6, and 10 minutes after application of HB and compared for agreement. The mean paired κ statistic for assignment of SG scores was .7754. The mean paired κ statistics for determining eligibility for participation in the trial based on bleeding severity and the mean paired κ statistics determining the presence of hemostasis were .9301 and .9301, respectively. The proportion of patients achieving hemostasis within 3, 6, and 10 minutes of HB application were 50.0%, 79.2%, and 91.7%, respectively. There were no unanticipated adverse device effects and one possible serious adverse device effect, as determined by the Independent Data Monitoring Committee (IDMC). The reliability of the SG scale was validated in a clinical setting. Initial data on the safety and efficacy of HB in abdominal and orthopedic operations were collected, and there were no concerns raised by the investigators or the IDMC.

Safety and feasibility of PuraStat® in laparoscopic colorectal surgery (Feasibility study)

Introduction: Haemorrhage remains a major cause of morbidity and death in all surgical specialties. The aim of this study was to analyse the feasibility of PuraStat^®, a new synthetic haemostatic device, made of self-assembling peptides in laparoscopic colorectal surgery.Material and methods: This was a prospective observational non-randomised study. Consecutive patients undergoing laparoscopic colorectal surgery were enrolled. Inclusion criterion was the need employ a secondary method of haemostasis when traditional methods such as conventional pressure or utilization of energy devices to control the bleeding were either insufficient or not recommended.Results: Twenty patients were enrolled. The mean time to apply the product was 40 secs (±17 secs), whereas the mean time to achieve haemostasis was 17.5 secs (±3.5 secs). There were no post-operative complications in this cohort of 20 patients. Mean operative time overall was 185 mins (±45.2 mins). None of the patients experienced delayed post-operative bleeding and the mean hospital stay was five days (±3,4).Conclusions: We demonstrated that PuraStat^® can be easily used in laparoscopic surgery and it is a safe, effective haemostatic agent. This is a feasibility study and additional controlled studies would be useful in the future.

Evaluation of the safety and efficacy of a new hemostatic powder using a quantitative surface bleeding severity scale

AIMS OF THE STUDY

The safety and efficacy of a hemostatic powder (HP) versus a control agent, absorbable gelatin sponge and thrombin (G + T), were assessed, using a validated, quantitative bleeding severity scale.

METHODS

Subjects were randomized to receive HP (256 subjects) or G + T (132 subjects) for treatment of minimal, mild, or moderate bleeding at 20 investigational sites. The primary efficacy endpoint was non-inferiority of HP relative to G + T for success at achieving hemostasis within 6 minutes. Secondary endpoints in rank order included: superiority of HP relative to G + T in mean preparation time; non-inferiority of HP relative to G + T for achieving hemostasis within 3 min; superiority of HP relative to G + T for achieving hemostasis within 6 min; and superiority of HP relative to G + T for success for achieving hemostasis within 3 min.

RESULTS

A total of 388 subjects were included in the primary efficacy analysis. At 6 min, hemostasis was achieved in 93.0% (238/256) of the HP group compared to 77.3% (102/132) of the G + T group (non-inferiority P < 0.0001, superiority P < 0.0001). All secondary endpoints were met. Complications were comparable between treatment groups.

CONCLUSIONS

HP had superior rates of hemostasis, shorter preparation time, and a similar safety profile compared to G + T in this prospective, randomized trial using quantitative bleeding severity criteria.

Hemostatic Comparison of a Polysaccharide Powder and a Gelatin Powder

Purpose/Aim: Powdered hemostats have been widely adopted for their ease-of-use; however, their efficacy has been limited resulting in applications restricted to low-level bleeds. This study investigates the use of bovine-derived gelatin particles (BGP) as a standalone hemostatic powder and compare BGP to commercially available microporous polysaccharide hemospheres (MPH). Materials and Methods: The powders were investigated for their hemostatic efficacy in a heparinized pre-clinical bleeding model limited to grade 1 and 2 bleeds on a validated intraoperative bleeding scale, which represents the accepted, clinical use of hemostatic powders. Results: At 10 minutes, the hemostatic success of lesions treated with BGP were 78% while MPH were 22%. The odds ratio for hemostatic success of BGP relative to MPH was 15.18 (95% CI: 7.37, 31.27). The 95% lower limit of the odds ratio was greater than 1. This indicates that BGP are superior to MPH (p < 0.001). The median time to hemostasis for BGP was 1.6 minutes and MPH was 14.5 minutes. The ratio for time to hemostasis of MPH relative to BGP was 9.23 (95% CI: 6.99, 12.19). This indicates that BGP achieve significantly faster time to hemostasis (p < 0.001). Conclusions: Characterization of tissue explant ultrastructure, particle size, and swelling revealed differences in the materials. BGP, in addition to absorbing fluid and concentrating clotting factors and platelets, integrate into the clot and stabilize the fibrin matrix. BGP have advantages over MPH in terms of speed and efficacy. BGP are a favorable biomaterial for further research that greatly improve the limited efficacy of powdered hemostats.

Next Generation Hemostatic Materials Based on NHS-Ester Functionalized Poly(2-oxazoline)s

In order to prevent hemorrhage during surgical procedures, a wide range of hemostatic agents have been developed. However, their efficacy is variable; hemostatic devices that use bioactive components to accelerate coagulation are dependent on natural sources, which limits reproducibility. Hybrid devices in which chain-end reactive poly(ethylene glycol) is employed as active component sometimes suffer from irregular cross-linking and dissolution of the polar PEG when blood flow is substantial. Herein, we describe a synthetic, nonbioactive hemostatic product by coating N-hydroxysuccinimide ester (NHS)-functional poly(2-oxazoline)s (POx-NHS) onto gelatin patches, which acts by formation of covalent cross-links between polymer, host blood proteins, gelatin and tissue to seal the wound site and prevent hemorrhage during surgery. We studied different process parameters (including polymer, carrier, and coating technique) in direct comparison with clinical products (Hemopatch and Tachosil) to obtain deeper understanding of this class of hemostatic products. In this work, we successfully prove the hemostatic efficacy of POx-NHS as polymer powders and coated patches both in vitro and in vivo against Hemopatch and Tachosil, demonstrating that POx-NHS are excellent candidate polymers for the development of next generation hemostatic patches.

Improved bleeding scores using Gelfoam(®) Powder with incremental concentrations of bovine thrombin in a swine liver lesion model

Topical hemostatic agents are used intra-operatively to prevent uncontrolled bleeding. Gelfoam(®) Powder contains a hemostatic agent prepared from purified pork skin gelatin, the efficacy of which is increased when combined with thrombin. However, the effect of increasing concentrations of thrombin on resultant hemostasis is not known. This study sought to evaluate the ability of various concentrations of thrombin in combination with Gelfoam Powder to control bleeding using a swine liver lesion model. Ten pigs underwent a midline laparotomy. Circular lesions were created in the left medial, right medial, and left lateral lobes; six lesions per lobe. Gelfoam Powder was hydrated with Thrombin-JMI(®) diluted to 250, 375, and 770 IU/mL. Each concentration was applied to two lesion sites per lobe. Bleeding scores were measured at 3, 6, 9, and 12 min using a 6-point system; comparison of bleeding scores was performed using ANOVA with the post hoc Tukey test. The bleeding scores with thrombin concentrations at 770 IU/mL were significantly lower than at 250 and 375 IU/mL at all four time points. The percentage of biopsies with a clinically acceptable bleeding score rose from 37.9, 46.6, and 71.2 % at 3 min to 55.2, 69.0, and 88.1 % at 12 min in the 250, 375, and 770 IU/mL thrombin groups, respectively. The study showed that the hemostatic response to thrombin was dose-related: using higher concentrations of thrombin with Gelfoam Powder yielded improved hemostasis, as determined by lower bleeding scores.

Use of Monsel solution to treat obstetrical hemorrhage: a review and comparison to other topical hemostatic agents

Peripartum hemorrhage accounts for 8% of maternal deaths in the United States, and nearly 27% worldwide. A growing need exists for tactics to spare morbidity given a rise of abnormal placentation that contributes to excessive blood loss at the time of delivery. Approaches such as compression sutures, balloon tamponade, and pelvic artery embolization are not without side effects and potential implications for future fertility. The use of topical hemostatic agents has become widespread in gynecologic and obstetric surgery despite a paucity of distinct studies in the field, and may allow providers to increasingly avoid cesarean hysterectomy. A variety of topical hemostatic agents exist along a wide cost continuum, each characterized by specific efficacy, advantages, drawbacks, and often gaps in long-term data to support safety and impact on future fertility. Herein, we comprehensively review these agents and illustrate a nontraditional use of Monsel solution applied directly to the placental bed in a case of focal placenta accreta. This ultimately contributed to successful uterine preservation with no known adverse sequelae. Monsel solution may have a role in establishing hemostasis in the setting of abnormal placentation, and may be a particularly attractive alternative in resource-poor nations.

Randomized, controlled comparison of advanced hemostatic pads in hepatic surgical models

Blood loss during hepatic surgery leads to poor patient outcomes. This study investigates the hemostatic efficacy of a novel sealing hemostatic pad (polyethylene glycol-coated collagen, PCC) and a fibrin sealant pad (fibrin-thrombin coated collagen, FTC) in a leporine hepatic segmentectomy and a porcine hepatic abrasion model. A segmentectomy was used to compare hemostatic success and hematoma incidence in 20 rabbits (10/group). Hepatic abrasions were used to compare hemostatic success up to 10 min after application in six pigs (42 lesions/group). In the segmentectomy model, PCC achieved 100% hemostatic success within 2 min (95% CI: 72.3% to 100%) and FTC achieved 80% hemostatic success within 3 min (49.0% to 94.3%). PCC had lower hematoma incidence at 15 min (0.0 versus 11.1%) and 24 h (20.0 versus 66.7%). In the abrasion model, PCC provided superior hemostatic success at 3 (odds ratio: 24.8, 95% CI: 8.86 to 69.2, P < 0.001), 5 (66.3, 28.5 to 153.9, P < 0.001), 7 (177.5, 64.4 to 489.1, P < 0.001), and 10 min (777.6, 148.2 to 4078, P < 0.001) leading to statistically significant less blood loss. The novel sealing hemostat provides faster and more sustained hemostasis than a fibrin sealant pad in a leporine hepatic segmentectomy and a porcine hepatic abrasion model of hepatic surgery.

Comparison of regenerated and non-regenerated oxidized cellulose hemostatic agents

Background

Oxidized cellulose is a well known and widely used surgical hemostat. It is available in many forms, but manufactured using either a nonregenerated or regenerated process.

Objective

This study compares the fiber structure, pH in solution, bactericidal effectiveness, and hemostatic effectiveness of an oxidized nonregenerated cellulose (ONRC; Traumastem^®) and an oxidized regenerated cellulose (ORC; Surgicel^® Original).

Methods

In vitro, fiber structures were compared using scanning electron microscopy, pH of phosphate buffer solution (PBS) and human plasma were measured after each cellulose was submerged, and bactericidal effect was measured by plating each cellulose with four bacteria. In vivo, time to hemostasis and hemostatic success were compared using a general surgery nonheparinized porcine liver abrasion model and a peripheral vascular surgery heparinized leporine femoral vessel bleeding model.

Results

Ultrastructure of ONRC fiber is frayed, while ORC is smooth. ORC pH is statistically more acidic than ONRC in PBS, but equal in plasma. No difference in bactericidal effectiveness was observed. In vivo, ONRC provided superior time to hemostasis relative to ORC (211.2 vs 384.6 s, N = 60/group) in the general surgery model; and superior hemostatic success relative to ORC at 30 (60 vs. 15 %; OR: 13.5; 95 % CI: 3.72–49.1, N = 40/group), 60 (85 vs. 37.5 %; OR: 12.3; 95 % CI: 3.66–41.6), and 90 s (97.5 vs 70.0 %; OR: 21.1, 95 % CI: 2.28–195.9) in the peripheral vascular model.

Conclusion

ONRC provides superior hemostasis and equivalent bactericidal effectiveness relative to ORC, which is likely due to its fiber structure than acidity.

Comparison of two gelatin and thrombin combination hemostats in a porcine liver abrasion model

Background:

Surgical hemostasis is achieved using adjunctive hemostats when conventional methods fail.

Objective:

This study compares the effectiveness of two adjunctive gelatin-thrombin hemostats.

Hypothesis:

To determine effectiveness, hemostats were compared in vivo, in vitro, and using scanning electron microscopy (SEM).

Methods:

In vivo, a heparinized porcine liver abrasion model was used to compare hemostatic success, degree of bleeding, and blood loss at 2, 5, and 10 minutes post-treatment. In vitro, thrombin in the supernatant of each hemostat and Red Blood Cells (RBC'S) in the supernatant of clots formed by each was compared.

Results:

Ultrastructure of one gelatin was smooth and the other stellate. In vivo, smooth gelatin provided superior hemostatic success at 5 (85% vs. 60%; OR: 5.3; 95% CI: 1.66 to 17.9) and 10 mins (72.5% vs. 47.5%; OR: 5.0; 95% CI: 1.55 to 16.1). Smooth gelatin had a statistically different degree of bleeding at 5 (0.58 ± 0.87 [Mean ± SD] vs. 1.03 ± 1.12; OR: 3.36; 95% CI: 1.34 to 8.41) and 10 mins (1.13 ± 1.14 vs. 1.65 ± 1.05; OR: 3.87; 95% CI: 1.62 to 9.21). Mean blood loss was less with smooth gelatin at 2 (0.07 ± 0.19 vs. 0.13 ± 0.63 ml/min), 5 (0.04 ± 0.13 vs. 0.23 ± 0.45 ml/min), and 10 mins (0.09 ± 0.24 vs. 0.21 ± 0.32 ml/min). In vitro, supernatant of smooth gelatin had significantly less thrombin (6.81 vs. 10.9 IU/ml, p = .001), and significantly less RBC's than stellate gelatin (0.07 vs. 0.09 × 10⁶/ul, p = .0085).

Conclusion:

Smooth gelatin has an increased ability to retain thrombin and RBC's in vitro which may explain why it provides superior hemostatic effectiveness, superior control of bleeding, and greater reduced blood loss in vivo.

Hemostatic Agents in Hepatobiliary and Pancreas Surgery: A Review of the Literature and Critical Evaluation of a Novel Carrier-Bound Fibrin Sealant (TachoSil)

Background. Despite progress in surgical techniques applied during hepatobiliary and pancreas (HPB) surgery, bleeding and bile leak remain significant contributors to postoperative mortality and morbidity. Topical hemostatics have been developed and utilized across surgical specialties, but data regarding effectiveness remains inconsistent and sparse in HPB surgery. Methods. A comprehensive search for studies and reviews on hemostatics in HPB surgery was performed via an October 2011 query of Medline, EMBASE, and Cochrane Library. In-depth evaluation of a novel carrier-bound fibrin sealant (TachoSil) was also performed. Results. The literature review illustrates multiple attempts have been made at developing different topical hemostatics and sealants to aid in surgical procedures. In HPB surgery, efforts have been directed at decreasing bleeding, biliary leakage, and pancreatic fistula. Conflicting scientific evidence exists regarding the effectiveness of these agents. Critical evaluation of the literature demonstrates TachoSil is a valuable tool in achieving hemostasis, and possibly biliostasis and pancreatic fistula prevention. Conclusion. While progress has been made in topical hemostatics for HPB surgery, an ideal agent has not yet been identified. TachoSil is promising, but larger randomized, controlled clinical trials are required to more fully evaluate its efficacy in reducing bleeding, biliary leakage, and pancreatic fistulas in HPB surgery.

Hemostatic Agents in Hepatobiliary and Pancreas Surgery: A Review of the Literature and Critical Evaluation of a Novel Carrier-Bound Fibrin Sealant (TachoSil)

Background. Despite progress in surgical techniques applied during hepatobiliary and pancreas (HPB) surgery, bleeding and bile leak remain significant contributors to postoperative mortality and morbidity. Topical hemostatics have been developed and utilized across surgical specialties, but data regarding effectiveness remains inconsistent and sparse in HPB surgery. Methods. A comprehensive search for studies and reviews on hemostatics in HPB surgery was performed via an October 2011 query of Medline, EMBASE, and Cochrane Library. In-depth evaluation of a novel carrier-bound fibrin sealant (TachoSil) was also performed. Results. The literature review illustrates multiple attempts have been made at developing different topical hemostatics and sealants to aid in surgical procedures. In HPB surgery, efforts have been directed at decreasing bleeding, biliary leakage, and pancreatic fistula. Conflicting scientific evidence exists regarding the effectiveness of these agents. Critical evaluation of the literature demonstrates TachoSil is a valuable tool in achieving hemostasis, and possibly biliostasis and pancreatic fistula prevention. Conclusion. While progress has been made in topical hemostatics for HPB surgery, an ideal agent has not yet been identified. TachoSil is promising, but larger randomized, controlled clinical trials are required to more fully evaluate its efficacy in reducing bleeding, biliary leakage, and pancreatic fistulas in HPB surgery.

Iatrogenic cerebral venous sinus occlusion with flowable topical hemostatic matrix

Object

The use of commercially available topical hemostatic adjuncts has increased the safety profile of surgery as a whole. Cranial surgery has also benefited from the development of numerous agents designed to permit more rapid achievement of hemostasis. Flowable topical hemostatic agents applied via syringe injection are now commonly employed in many neurosurgical procedures, including cranial surgery. Intravascular use of these strongly thrombogenic agents is contraindicated, but in certain settings, inadvertent intravascular administration can occur, resulting in vascular occlusion, thrombosis, and potential dissemination. To date, there have no reports detailing the presence and incidence of this complication.

Methods

The authors conducted a retrospective review of all cranial surgeries performed at Presbyterian University Hospital by members of the University of Pittsburgh Medical Center's Department of Neurological Surgery between 2007 and 2009. Cases complicated by vascular occlusion due to inadvertent intravascular administration of flowable topical hemostatic matrix (FTHM) were identified and analyzed.

Results

Iatrogenic vascular occlusion induced by FTHM was identified in 5 (0.1%) of 3969 cranial surgery cases. None of these events occurred in 3318 supratentorial cases, whereas 5 cases of cerebral venous sinus occlusion occurred in 651 infratentorial cases (0.8%). The risk of accidental vessel occlusion was significantly associated with infratentorial surgery, and all events occurred in the transverse and/or sigmoid sinus. No episodes of inadvertent vascular occlusion occurred during endoscopic surgery. No cases of arterial occlusion were identified. Of the 5 patients with FTHM-related cerebral venous sinus occlusion, none developed long-term neurological sequelae referable to the event.

Conclusions

Inadvertent intravascular administration of FTHM is a rare complication associated with cranial surgery that occurs most commonly during infratentorial procedures around the transverse and/or sigmoid sinuses. Modifications in the choice of when to use an FTHM and the method of application may help prevent accidental venous sinus administration.

State-of-the-Art Review: Hemostats, Sealants, and Adhesives II: Update As Well As How and When to Use the Components of the Surgical Toolbox

The goal of this submission is to describe how and when to best use hemostats, sealants, and adhesives as well as to compare their characteristics and to update the surgical toolbox with respect to any new products approved by the Food and Drug Administration (FDA) as of this date (November 2009). The materials will be presented in 3 major groups each containing specific categories: (1) hemostats; mechanical, active, flowable, and fibrin sealant, (2) sealants; fibrin sealant, polyethylene glycol polymer, and albumin and glutaraldehyde, (3) adhesives; cyanoacrylate, albumin and glutaraldehyde, and fibrin sealant. The categories will be used for comparisons based on safety, efficacy, usability, and cost. Recommendations with respect to how and when to best use these materials will be presented. A review of the recent literature is also provided with respect to the most recent uses of these materials in specific surgical specialties.

Topical recombinant thrombin at a concentration of 1000 IU/mL reliably shortens in vivo TTH and delivers durable hemostasis in the presence of heparin anticoagulation and clopidogrel platelet inhibition in a rabbit model of vascular bleeding

Background

This study was designed to evaluate the effect of recombinant human thrombin (rThrombin) concentration on time to hemostasis (TTH), clot durability, and clot strength in settings that replicate the heparinization and platelet inhibition often found in surgical populations.

Methods

A modified, anticoagulated rabbit arteriovenous shunt preparation was selected to model vascular anastomotic bleeding. Rabbits were treated with heparin or heparin + clopidogrel and TTH was measured after applying a range of topical rThrombin concentrations or placebo, in combination with absorbable gelatin sponge, USP. Treatments (placebo, rThrombin) were randomly assigned and the investigator was blinded to treatment. TTH was evaluated with the Kaplan-Meier method. After hemostasis was achieved, clot burst assessment was performed for heparin + clopidogrel treated animals. Clot viscoelastic strength and kinetics were measured in ex-vivo samples using thromboelastography (TEG) methods.

Results

TTH decreased with increasing concentrations of rThrombin in heparin-treated animals and was shorter after treatment with 1000 IU/mL rThrombin (73 seconds) than with 125 IU/mL rThrombin (78 seconds; p = 0.007). TTH also decreased with increasing concentrations of rThrombin in heparin + clopidogrel treated animals; again it was significantly shorter after treatment with 1000 IU/mL rThrombin (71 seconds) than with 125 IU/mL rThrombin (177 seconds; p < 0.001). Variability in TTH was significantly smaller after treatment with 1000 IU/mL rThrombin than after 125 IU/mL rThrombin, indicating greater reliability of clot formation (p < 0.001 for heparin or heparin + clopidogrel treatments). Clot durability was examined in heparin + clopidogrel treated animals. Clots formed in the presence of 1000 IU/mL rThrombin were significantly less likely to rupture during clot burst assessment than those formed in the presence of 125 IU/mL rThrombin (0% versus 79%, p < 0.001). In vitro clot strength and clot kinetics, as determined by TEG in heparin + clopidogrel samples, were positively associated with the amount of rThrombin activity added for clot initiation.

Conclusion

In an animal model designed to replicate the anti-coagulation regimens encountered in clinical settings, topical rThrombin at 1000 IU/mL more reliably controlled the pharmacological effects of heparin or heparin + clopidogrel on hemostasis than rThrombin at 125 IU/mL. Results from in vitro assessments confirmed a positive relationship between the amount of rThrombin activity and both the rate of clot formation and clot strength.