Fate of fibrin sealant in pericardial space

Reprograming Clots for In Vivo Chemical Targeting in Traumatic Brain Injury

Traumatic brain injury (TBI) is a critical public health concern, yet there are no therapeutics available to improve long-term outcomes. Drug delivery to TBI remains a challenge due to the blood-brain barrier and increased intracranial pressure. In this work, a chemical targeting approach to improve delivery of materials to the injured brain, is developed. It is hypothesized that the provisional fibrin matrix can be harnessed as an injury-specific scaffold that can be targeted by materials via click chemistry. To accomplish this, the brain clot is engineered in situ by delivering fibrinogen modified with strained cyclooctyne (SCO) moieties, which incorporated into the injury lesion and is retained there for days. Improved intra-injury capture and retention of diverse, clickable azide-materials including a small molecule azide-dye, 40 kDa azide-PEG nanomaterial, and a therapeutic azide-protein in multiple dosing regimens is subsequently observed. To demonstrate therapeutic translation of this approach, a reduction in reactive oxygen species levels in the injured brain after delivery of the antioxidant catalase, is achieved. Further, colocalization between azide and SCO-fibrinogen is specific to the brain over off-target organs. Taken together, a chemical targeting strategy leveraging endogenous clot formation is established which can be applied to improve therapeutic delivery after TBI.

In vivo near-infrared fluorescent fibrin highlights growth of nerve during regeneration across a nerve gap

SIGNIFICANCE

Exogenous extracellular matrix (ECM) proteins, such as fibrinogen and the thrombin-polymerized scaffold fibrin, are used in surgical repair of severe nerve injuries to supplement ECM produced via the injury response. Monitoring the dynamic changes of fibrin during nerve regeneration may shed light on the frequent failure of grafts in the repair of long nerve gaps.

AIM

We explored whether monitoring of fibrin dynamics can be carried out using nerve guidance conduits (NGCs) containing fibrin tagged with covalently bound fluorophores.

APPROACH

Fibrinogen was conjugated to a near-infrared (NIR) fluorescent dye. NGCs consisting of silicone tubes filled with the fluorescent fibrin were used to repair a 5-mm gap injury in rat sciatic nerve ( n = 6 ).

RESULTS

Axonal regeneration in fluorescent fibrin-filled NGCs was confirmed at 14 days after implantation. Intraoperative fluorescence imaging after implantation showed that the exogenous fibrin was embedded in the early stage regenerative tissue. The fluorescent signal temporarily highlighted a cable-like structure within the conduit and gradually degraded over two weeks.

CONCLUSIONS

This study, for the first time, visualized in vivo intraneural fibrin degradation, potentially a useful prospective indicator of regeneration success, and showed that fluorescent ECM, in this case fibrin, can facilitate imaging of regeneration in peripheral nerve conduits without significantly affecting the regeneration process.

Long-term effects of pleural defect repair using sheet materials in a canine model

OBJECTIVE

A sheet material is widely used to repair pleural defects due to its excellent pressure resistance. We examined the long-term effects of sheet materials using an animal pleural defect model.

METHODS

Beagles were used for this study. The 5-mm circular pleural defects were created at 2 sites on each of the anterior, medial, and posterior lobe and repaired using a 2 cm square sheet material. The frequency of adhesion of those sheets to the thoracic walls and histological changes was examined after 6 months. In this study, three types of sheet materials were examined: polyglycolic acid, nano-polyglycolic acid, and oxidized regenerated cellulose where each sheet was tested with or without coating with fibrin glue, for a total of 6 groups. Each group contained an equal number of defect sites and evaluation of 12 defect sites was conducted.

RESULTS

Adhesion was observed in 16 of 72 sites (22%). Presence or absence of adhesion was not affected by the repair method or by the type of sheet material used. However, the use of fibrin glue significantly reduced the occurrence of adhesion (p = 0.023). At the defected sites, the posterior lobe showed significantly less adhesion (p = 0.019). Histologically, the sheet materials caused a thickening of the pleural wall 6-10 times thicker than the normal pleural wall.

CONCLUSION

No statistically significant differences regarding the presence or absence of adhesion to the thoracic wall were found among the sheet materials. The use of fibrin glue significantly reduced the adhesion to the thoracic wall.

Haemostasis with fibrin glue injection into the pericardial space for right ventricular perforation caused by an iatrogenic procedural complication

An 89-year-old woman with severe aortic valve stenosis and bradycardia presented with circulatory shock due to cardiac tamponade. We performed pericardiocentesis, and then diagnosed right ventricular perforation by echocardiography with microcavitation contrast medium just before inserting a drainage tube. We then inserted the drainage tube in the appropriate position and withdrew blood-filled fluid. The patient was haemodynamically stabilised, but haemorrhage from the perforation site continued for a few days. We injected fibrin glue into the pericardial space through the drainage tube and achieved haemostasis. Thus, we avoided surgery to close the perforation in this high-risk patient. There was no recurrence of haemorrhage. She subsequently had elective aortic valve replacement at another hospital. No adhesions in the pericardial space were seen during surgery.

Non-invasive in vivo tracking of fibrin degradation by fluorescence imaging

Fibrin-based sealants consist of natural coagulation factors involved in the final phase of blood coagulation, during which fibrinogen is enzymatically converted by thrombin to form a solid-phase fibrin clot. For applications in tissue regeneration, a controlled process of matrix degradation within a certain period of time is essential for optimal wound healing. Hence, it is desirable to follow the kinetics of fibrinolysis at the application site. Non-invasive molecular imaging systems enable real-time tracking of processes in the living animal. In this study, a non-invasive fluorescence based imaging system was applied to follow and quantify site-specific degradation of fibrin sealant. To enable non-invasive tracking of fibrin in vivo, fibrin-matrix was labelled by incorporation of a fluorophore-conjugated fibrinogen component. Protein degradation and release of fluorescence were, in a first step, correlated in vitro. In vivo, fluorophore-labelled fibrin was subcutaneously implanted in mice and followed throughout the experiment using a multispectral imaging system. For the fluorescent fibrin, degradation correlated with the release of fluorescence from the clots in vitro. In vivo it was possible to follow and quantify implanted fibrin clots throughout the experiment, demonstrating degradation kinetics of approximately 16 days in the subcutaneous compartment, which was further confirmed by histological evaluation of the application site.

In vitro antimicrobial activity of fibrin sealants containing antimicrobial agents

BACKGROUND

Antimicrobial prophylaxis is required to prevent surgical site infections (SSIs). However, it is difficult to maintain prolonged antimicrobial activity in the surgical incision. Fibrin sealants are used primarily for hemostasis, suture support, or the adhesion of tissues. The aim of this study was to develop fibrin sealants that exhibit antimicrobial activity due to the addition of an antimicrobial agent.

METHODS

We determined the potencies and activities of cefazolin, ampicillin-sulbactam, vancomycin, teicoplanin, and arbekacin eluted from fibrin sealants. The antimicrobial activity was evaluated using methicillin-resistant Staphylococcus aureus (MRSA), multi-drug-resistant Pseudomonas aeruginosa (MDRP), and multi-drug-resistant Acinetobacter baumannii (MDRAB), which are the major pathogens responsible for hospital-acquired infections.

RESULTS

Each antimicrobial agent eluted continuously from the fibrin clots for approximately two weeks. All eluates from fibrin clots containing antimicrobial agents maintained antimicrobial activity against MRSA for at least 7 d. The eluates from fibrin clots containing ampicillin-sulbactam inhibited the growth of both MDRP and MDRAB for at least 5 d.

CONCLUSION

Our data suggest that the addition of an antimicrobial agent to fibrin sealants is a useful method to prevent SSIs caused by bacteria, including antimicrobial-resistant strains.

Intra-pericardial thrombin injection for post-infarction left ventricular free wall rupture

Left ventricular free wall rupture (LVFWR) is a fatal complication of acute myocardial infarction. Different modalities of treatment were previously described, including surgical intervention and medical treatment. We report a case treated with intra-pericardial thrombin injection that gave a favourable outcome for a patient who presented with LVFWR and cardiac tamponade, following acute myocardial infarction.

Paste-pinch-cut conjunctivoplasty: subconjunctival fibrin sealant injection in the repair of conjunctivochalasis

PURPOSE

To describe a new surgical technique for the repair of conjunctivochalasis (CCh) using subconjunctival injection of fibrin sealant followed by conjunctival resection and to present a case series demonstrating our experience with the paste-pinch-cut technique.

METHODS

A total of 139 eyes of 70 patients (43 women, 27 men) with CCh unresponsive to medical therapy received the described surgical treatment. The procedure consists of 3 primary steps-paste: fibrin sealant is injected subconjunctivally in a line inferior to the limbus; pinch: the conjunctiva is grasped with curved ptosis forceps, gathering the excess conjunctiva into a ridge, which is held, allowing the sealant to polymerize; and cut: the ridge of excess conjunctiva and sealant is resected. Subjective symptoms were assessed after surgery.

RESULTS

Conjunctival redundancy was absent postoperatively in all eyes, resulting in a smooth conjunctival surface and restored tear meniscus. At the 3-month follow-up visit, 91.4% of patients reported improvement in symptoms. There were no recurrences or significant complications.

CONCLUSIONS

The present retrospective, noncomparative, consecutive, interventional case series study introduces paste-pinch-cut conjunctivoplasty as a simple and an effective surgical treatment for the repair of CCh in symptomatic patients.

Determination of porcine fibrinogen in rat and dog plasma after intraperitoneal injection of a porcine-derived fibrin glue by fluorescein-labeled assay method: Comparison with isotope-labeled assay method

A sensitive and specific fluorescein isothiocyanate (FITC) label coupled with size-exclusion high-performance liquid chromatography-fluorescence detection (SE-HPLC-FLD) method was developed and validated for the estimation of the pharmacokinetic profiles of porcine fibrinogen after intraperitoneal injection of a porcine-derived fibrin glue (FG) to SD rats and beagle dogs with three single doses. Porcine fibrinogen, the major composition of the FG, was labeled with FITC. The FG containing FITC-labeled porcine fibrinogen was intraperitoneally administered to SD rats at three single dosages (100, 200, 400mg/kg of porcine fibrinogen), and the collected plasma was then detected by SE-HPLC-FLD method. The present technique was compared to the previously introduced isotope-labeled assay method for the pharmacokinetic studies in SD rats. The pharmacokinetic studies in SD rats showed that the correlation coefficient between the FITC-labeled assay and (125)I-labeled assay methods was r(2)=0.989. Thus, this FITC-labeled assay method performed well and demonstrated high concordance with the previous (125)I-labeled assay method, suggesting that FITC-labeled assay could substitute the (125)I-labeled assay as a method of choice for quantification in beagle dogs. Then the plasma levels of porcine fibrinogen in beagle dogs were studied by the FITC-labeled assay method with three single doses (15, 30, 60mg/kg of porcine fibrinogen). The method validation showed that the FITC label coupled with SE-HPLC-FLD method was suitable for the quantification of porcine fibrinogen in plasma samples with satisfactory linear (r(2)>0.999), precision (<12%), accuracy (95.5-104.9%) and recovery (>88%). The results showed linear disposition of porcine fibrinogen at the examined dosage range in SD rats or beagle dogs.

Outcome of percutaneous intrapericardial fibrin-glue injection therapy for left ventricular free wall rupture secondary to acute myocardial infarction

Left ventricular free wall rupture (LVFWR) is a fetal complication of acute myocardial infarction. This study was conducted to test the feasibility of percutaneous intrapericardial fibrin-glue injection therapy (PIFIT) for LVFWR after acute myocardial infarction and to assess its clinical outcome. From January 2000 to December 2004, LVFWR was confirmed by echocardiography in 22 patients. Thirteen patients showing abrupt hemodynamic collapse failed to recover from resuscitation maneuvers and died <2 hours after LVFWR. The remaining 9 patients (5 women, mean age 73 +/- 10 years) underwent PIFIT. Pericardiocentesis was performed from the subxiphoid process, and a 6Fr pigtail catheter was introduced into the pericardial space. After bloody fluid was drained from the catheter, the fibrin glue was injected into the pericardial space. There were no complications relating to pericardiocentesis and PIFIT. One patient underwent surgical repair on the day of PIFIT because of uncontrollable bleeding from pericardial drainage. In-hospital death as a result of rerupture occurred in 2 patients on days 4 and 7 after PIFIT. Echocardiography during follow-up revealed no evidence of pseudoaneurysm or left ventricular restriction. On follow-up at a median of 4.0 years (interquartile range 3.1 to 4.8), 1 noncardiac death occurred at 3.3 months. The other 5 patients were free of cardiovascular events and in New York Heart Association functional class I. In conclusion, PIFIT is a simple, effective, and less invasive technique for the management of LVFWR and thus can be an alternative to surgical repair for LVFWR after acute myocardial infarction.

Glutamine Administration Enhances the Healing of Lung Parenchymal Injuries and Reduces Air Leakage in Rats

Beneficial effects of glutamine on wound healing are well known. Parenchymal injuries in the lung cause air leakage that resolves with wound healing. We aimed to determine the effect of glutamine on the healing of lung injuries. Wistar albino female rats were randomized in three groups. One group (control, n = 7) received intraperitoneal injection of 0.9% sodium chloride (1.5 ml /day), while other group (GLN, n = 7) received glutamine (1.5 g/kg/day), beginning two days prior to the operation for total four days. After thoracotomy, a lung parenchymal lesion was made with a scalpel in the right upper lobe. Only thoracotomy was performed to sham group (n = 4). Air leakage was observed in the isolated lungs of control group, but not GLN and sham groups, at 5 cm H(2)O of positive airway pressure (p < 0.001). The threshold of positive airway pressure for air leakage was 4.85 +/- 0.37 and 19.42 +/- 4.54 cm H(2)O for control and GLN groups, respectively (p < 0.001). For measurement of collagen content in the healing parenchyma, digital images were processed to calculate the stained area percentage (SAP). SAP for immature collagen, a marker for wound healing, was 0.36 +/- 0.18% and 1.48 +/- 0.83% (p = 0.02) in control and GLN groups, respectively, but no significant difference was noted in SAP for mature collagen. The grade of inflammation was not significantly different between control and GLN groups. We conclude that glutamine enhances lung parenchymal healing by increasing immature collagen secretion.

Wound healing and degradation of the fibrin sealant Beriplast P following partial liver resection in rabbits

The objective of this study was to investigate the degradation kinetics of the fibrin sealant (FS) Beriplast P in an experimental liver surgery model in rabbits. A partial liver resection was performed in 21 rabbits, and the wound area covered with Beriplast P to ensure hemostasis. Wound healing of the resection sites was evaluated morphologically over 11 weeks. Degradation of the FS was evaluated by measuring the thickness of the remaining fibrin layer. Plasma samples were analyzed for antibodies against fibrinogen, albumin, thrombin, fibrin, and factor XIII. No postoperative hemorrhage was observed, indicating successful hemostasis throughout. The FS was degraded with a half-life of about 25 days postapplication and was completely replaced by granulation tissue within 9 weeks. The FS degradation and tissue development followed the general stages of wound healing: inflammation and resorption, proliferation, organization and production of collagen, maturation, and scarring. An immune reaction was elicited against the main four human proteins of the FS. The antibody titers peaked on day 14, with a gradual decrease thereafter. We conclude that the FS accomplished hemostasis, facilitated healing in accordance with natural processes, and was completely degraded over time. In humans, the reduced immunogenicity of the FS would potentially increase its degradation half-life.

A new method for establishing an intrapulmonary tumor in the rabbit

OBJECTIVES

Local treatments against malignant intrapulmonary tumors, such as radiotherapy, photodynamic therapy, and laser ablation therapy, are sometimes used in preference to surgery or chemotherapy. The efficacy of such treatments is dependent not only on the pathological type of the primary tumor, but also on loco-regional settings such as location of the lesion and relationship between the tumor and surrounding organs as well as tissues. Therefore, in order to evaluate the efficacy of a newly developed local treatment, it is essential to have a model in which a tumor can be established at an intended location. In this study, we developed a model for the establishment of an intrapulmonary tumor, using the rabbit.

METHODS

After induction of general anaesthesia, a catheter was inserted via the airway into the lung of a Japanese white rabbit, under X-ray guidance. The lung was then inoculated with a collagen gel matrix containing a suspension of VX2 cells derived from rabbit skin squamous cell carcinoma. Subsequent tumor growth was evaluated with X-ray imaging and pathological examination.

RESULTS

Growth of a solitary tumor at the target site was pathologically confirmed in 9 of 12 rabbits that were inoculated with 1 x 10(8) cells. In addition, tumor growth could be followed in 8 of 9 rabbits by chest X-ray examination. That is, a solitary intrapulmonary tumor could be established in 8 of 12 animals (67%).

CONCLUSION

The rabbit model reported here enables establishment of a solitary intrapulmonary tumor and thus can provide a suitable experimental setting for evaluation of local treatments of intrapulmonary tumors.

Long-term usefulness of percutaneous intrapericardial fibrin-glue fixation therapy for oozing type of left ventricular free wall rupture: a case report

This report describes a long-term survival case of left ventricular free wall rupture treated with percutaneous intrapericardial fibrin-glue fixation therapy. A 82-year-old woman was admitted to the emergency room because of vomiting and syncope diagnosed as acute posterolateral myocardial infarction complicated by cardiac tamponade. After her hemodynamic condition was stabilized by drawing off the bloody pericardial effusion, fibrin-glue was injected into pericardial space with the expectation that the glue would cover the oozing site of the left ventricular epicardium. After this therapy, the patient recovered and did not have any no recurrent cardiac events for 1 year. Serial echocardiographic studies revealed a preserved left ventricular function and no development of left ventricular restriction. This case suggests that percutaneous intrapericardial fibrin-glue fixation therapy is an effective treatment for the oozing type of left ventricular free wall rupture and that there is no risk of left ventricular restriction during long-term follow-up.

Comparison of the topical haemostatic agents for the prevention of suture hole bleeding. An experimental study

OBJECTIVE

using a rabbit vascular graft model we investigated the use of fibrin glue (FG), gelatin-resorcinol-formaldehyde (GRF), and collagen (C) as a means of reducing suture hole bleeding.

MATERIALS AND METHODS

twenty-eight rabbits were divided into four groups: fibrin glue, gelatin-resorcinol-formaldehyde, collagen and control. A 1 cm incision was made in the abdominal aortic wall of each animal. Incisions were covered with a polytetrafluoroethylene patch sutured with a 7-0 polypropylene. Fibrin Glue, GRF, and C were applied to cover suture holes in the groups 1, 2 and 3, respectively, but nothing in controls (group 4). The fibrin clot was allowed to achieve strength for 3 minutes before the clamps were reopened. After reopening the clamps, blood was collected from the surgical site using a syringe for a total of 2 min.

RESULTS

mean blood loss was significantly lower in the FG, GRF, and C compared with control group (p=0.0022, p=0.0022, and p=0.0017, respectively). The volume of blood lost and the time of haemostasis in the group 1 (FG) was less than those in groups 2 and 3 (GRF and C, respectively) (p=0.001). The haemostasis (defined 2 min later) was achieved only in group 1 (FG) (p=0.00067).

CONCLUSIONS

FG, GRF and C all reduce blood loss. Fibrin glue containing factor XIII was the most effective.