Objectives

To evaluate the effects of different local hemostatic agents in a new high flow vascular experimental bleeding model.

Design

Bovine thrombin combined with collagen matrix (bTcM), microporous polysaccharide hemospheres (MPH), freeze-dried rFVIIa with and without the combination of MPH were compared to a control group (solely compression) in a randomized fashion (20 animals/group). Primary endpoint was hemostasis, and secondary endpoints were time to hemostasis, blood loss, and blood pressure at hemostasis.

Methods

The common carotid artery of heparinized rats was ligated proximally and transected. Compression was applied for one minute followed by application of the topical hemostatic agent. Compression was maintained for another two minutes followed by re-evaluation of hemostasis: if bleeding continued additional compression was applied and thereafter bleeding was checked every minute until hemostasis.

Results

All animals in the bTcM group obtained hemostasis compared to 20% in the control group (p < 0.0001). The combination of MPH and rFVIIa (70% hemostasis) also showed a significant hemostatic capacity compared to control group (p < 0.001). None of the other active treatment groups differed compared to control group. Animals treated with bTcM had a significantly shorter time to hemostasis compared to animals in the other active treatment groups. No significant difference in blood loss and blood pressure at hemostasis was detected.

Conclusions

The most effective hemostatic agent was bTcM, followed by the combination of rFVIIa and MPH, while neither MPH nor rFVIIa alone displayed any hemostatic capacity compared to compression only.

Abstract

Objectives

To evaluate the use of Hemostatic Fibrin Glue in parotidectomy without the use of surgical drains.

Study design

Prospective cohort study of 10 patients undergoing parotidectomy. Surgery as a one day admission without the use of surgical drains was planned. The complication and duration of the hospital stay were obtained.

Methods

Parotidectomy was undertaken by one surgeon. Prior to wound closure, the skin flap and wound bed were approximated using Tisseel tissue sealant. Data regarding the incidence of any complication and the duration of the hospital stay were obtained. Patients were followed to assess surgical outcome and document any complications. The mean follow-up period was 8 months (range 4–12 months).

Results

There were no major surgical complications. Two patients had facial nerve weakness due to adherence of the tumour in the facial nerve, in there was which complete recovery after few months. All patients were discharged the next day. None of the patients felt that the discharge had been premature.

Conclusions

Parotidectomy can be undertaken safely without the need for surgical drains, therefore, allowing the patients to leave the hospital on the first postoperative day.

Abstract

Hemorrhage remains a leading cause of early death after trauma, and infectious complications in combat wounds continue to challenge caregivers. Although chitosan dressings have been developed to address these problems, they are not always effective in controlling bleeding or killing bacteria. We aimed to refine the chitosan dressing by incorporating a procoagulant (polyphosphate) and an antimicrobial (silver). Chitosan containing different amounts and types of polyphosphate polymers was fabricated, and their hemostatic efficacies evaluated in vitro. The optimal chitosan-polyphosphate formulation (ChiPP) accelerated blood clotting (p = 0.011), increased platelet adhesion (p = 0.002), generated thrombin faster (p = 0.002), and absorbed more blood than chitosan (p < 0.001). Silver-loaded ChiPP exhibited significantly greater bactericidal activity than ChiPP in vitro, achieving a complete kill of Pseudomonas aeruginosa and a >99.99% kill of Staphylococcus aureus consistently. The silver dressing also significantly reduced mortality from 90% to 14.3% in a P. aeruginosa wound infection model in mice. Although the dressing exerted severe cytotoxicity against cultured fibroblasts, wound healing was not inhibited. This study demonstrated for the first time, the application of polyphosphate as a hemostatic adjuvant, and developed a new chitosan-based composite with potent hemostatic and antimicrobial properties.

Abstract

Efficacious hemostatic agents have significant potential for use in rapid exsanguinating hemorrhage control by emergency medical technician or military medic nowadays. Unfortunately, the topical hemostats currently available in market still have various disadvantages. In this study, a series of macroporous chitosan coated mesoporous silica xerogel beads (CSSX) with good biocompatibility were developed. They consisted of mesoporous silica xerogel cores and chitosan layers with macroporous structure by using modified sol-gel process and PEG molecular imprinting technique. The textural properties of the CSSX beads were optimized by in vitro and in vivo evaluation for promoting blood clotting and the results indicated that the prepared CSSX beads can significantly accelerate the contact activation pathway of coagulation cascade and produce desirable hemostasis, with the best efficiency from the CSSX prepared with 2% chitosan and 5% PEG. Furthermore, these CSSX beads were observed to create no exothermic reaction and the subsequential tissue thermal injury by histological examination, and exhibited no obvious cytotoxicity even after 7 days. The results of the present study forward CSSX bead as a safe hemostatic system and present a platform for further optimization studies of materials with enhanced hemostatic capabilities for specific injury types.

Abstract

A case of early postoperative small bowel obstruction (SBO) after intraoperative use of hemostatic agents during laparoscopic staging for endometrial cancer is reported. A 46-year-old woman underwent a laparoscopic staging procedure for endometrial cancer during which hemostatic agents were used in the management of an iatrogenic injury to the inferior vena cava. The patient returned on postoperative day 6 with SBO and was taken to the operating department. She required a small bowel resection in the specific area where the hemostatic agents were used. Pathology showed extensive fibrotic changes caused by a foreign material that was suggestive of a thrombin-related product. Use of hemostatic agents should be considered as a cause in the differential diagnosis of patients with early postoperative SBO.

Abstract

Effective hemorrhage control becomes increasingly significant in today's military and civilian trauma, and current available local hemostatic agents have been reported to have various drawbacks and side effects. Herein in this study, a silver exchanged calcium doped ordered mesoporous silica sphere (AgCaMSS) with good degradability and antibacterial properties was developed for hemorrhage control. The well-ordered and symmetry hexagonal AgCaMSS with pore size of 3.2 nm, BET surface area of 919 m²/g and pore volume of 0.74 m³/g was prepared by one-step based catalyzed self-assembly and subsequent ion-exchange procedures. The degradation behaviors in Tris–HCl solution indicated that the addition of calcium and silver facilitated the dissolution and the weight loss of the prepared AgCaMSS could attain more than 40% after 42 days. The results obtained demonstrated that the optimal AgCaMSS formulation could significantly promote the blood clotting, activate the intrinsic pathway of coagulation cascade, induce platelet adherence. Consequently, effective hemostasis with low exothermic effects was achieved and the mortalities in femoral artery and liver injury models were reduced. The antibacterial experiment using broth culture method revealed that the prepared AgCaMSS had better antibacterial activities against Escherichia coli and Staphylococcus aureus. Based on these results, it can be concluded that the AgCaMSS developed here would be a promising material platform for designing hemostats in more extensive clinical application.

Abstract

A well-defined mesoporous structure of wollastonite with high specific surface area was synthesized using surfactant P123 (triblock copolymer) as template, and its composite scaffolds with poly(?-caprolactone) (PCL) were fabricated by a simple method of solvent casting-particulate leaching. The measurements of the water contact angles suggest that the incorporation of either mesoporous wollastonite (m-WS) or conventional wollastonite (c-WS) into PCL could improve the hydrophilicity of the composites, and the former was more effective than the later. The bioactivity of the composite scaffold was evaluated by soaking the scaffolds in a simulated body fluid (SBF) and the results show that the m-WS/PCL composite (m-WPC) scaffolds can induce a dense and continuous layer of apatite after soaking for 1 week, as compared with the scattered and discrete apatite particles on the c-WS/PCL composite (c-WPC) scaffolds. The m-WPC had a significantly enhanced apatite-forming bioactivity compared with the c-WPC owing to the high specific surface area and pore volume of m-WS. In addition, attachment and proliferation of MG₆₃ cells on m-WPC scaffolds were significantly higher than that of c-WPC, revealing that m-WPC scaffolds had excellent biocompatibility. Such improved properties of m-WPC should be helpful for developing new biomaterials and may have potential use in hard tissue repair.