An Experimental Study of Histopathologic Effects of Hemostatic Agents Used in Spinal Surgery

Topical hemostatic agents in spinal surgery

Spinal surgery can be associated with significant intraoperative blood loss which may lead to various complications. As the number of patients undergoing spinal surgery increases over time, accurate and effective hemostasis becomes critically important. Despite various surgical hemostatic techniques, conventional interventions such as compression, suture, ligation, and heat-generating cautery, are not suitable for osseous and epidural venous plexus bleeding during spinal procedures. Therefore, a variety of hemostatic agents have been developed to promote hemostasis. As they differ in terms of mechanism, form, application and potential adverse reactions, it is important to understand the natural features of existing agents. Here we comprehensively review currently available topical hemostatic agents from different sources and summarize their mechanisms of action, applications, and current or potential utilization in spinal surgery. We found hemostatic agents from different sources exert hemostatic actions through different mechanisms. In addition, topical hemostatic agents play various roles in spinal surgery including as hemostatic agent, dura mater repair, drug-carrier, skin closure, and fibrosis prevention. Compressive neurological complications are the most common complications of these hemostatic agents. Therefore, optimal use in spinal environments should match their features, indications, and efficacy with clinical conditions.

Spinal epidural fibrosis following hemostatic agent employment

OBJECTIVE

Failed Back Surgery Syndrome (FBSS) refers to a subset of patients who have new or persistent pain after spinal surgery for back or leg pain. Epidural fibrosis (EF) is a common cause of FBSS. Many agents aiming to prevent EF have been tested. However, hemostatic agents are readily available at hospitals, easy to reach and frequently used. For these reasons, oxidized regenerated cellulose, polysaccharide hemostat, hemostatic thrombin-gelatin matrix and chitosan linear polymer were evaluated for their effects on epidural fibrosis on rats after laminectomy.

METHODS

40 Sprague-Dawley rats were randomly divided into 5 equal groups including the control group where only the laminectomy was performed. The other 4 groups received hemostatic agents after laminectomy. The rats were euthanized 45 days later and were assessed by a blinded observer to grade the fibrosis level.

RESULTS

The study revealed that oxidized regenerated cellulose, polysaccharide hemostat and hemostatic thrombin-gelatin matrix lowered the epidural fibrosis grade which was statistically significant (p < 0.001). Although chitosan linear polymer created fibrosis similar to the control group it was not proven to be statistically significant (p = 0.8999). However, when compared with other hemostatic agents it resulted in a higher fibrosis grade (p < 0.001).

CONCLUSION

The results obtained from this experimental study revealed that Pahacel, Sealfoam and Surgiflo, were effective in reducing epidural fibrosis after laminectomy in rats.

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.

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.

Efficacy and Complications of Unilateral Biportal Endoscopic Spinal Surgery for Lumbar Spinal Stenosis: A Meta-Analysis and Systematic Review

OBJECTIVE

As an emerging minimally invasive endoscopic technique, unilateral biportal endoscopic spinal surgery (UBESS) has the advantages of flexibility, a wide and clear field of view, and less soft tissue damage. However, the clinical evidence is insufficient and controversy exists regarding UBESS for the treatment of lumbar spinal stenosis (LSS). In the present meta-analysis, we investigated the clinical efficacy and complications of UBESS for the treatment of LSS.

METHODS

The PubMed, Embase, Web of Science, and Cochrane Library databases were searched through to June 1, 2021 to identify all reported studies on UBESS for LSS. Only English-language studies with original reported data from ≥30 cases were considered for inclusion. The patient demographics, operative time, hospital stay, complications, visual analog scale (VAS) score, Oswestry disability index, and Macnab criteria were extracted. Quality assessment was performed using the Cochrane collaboration tool for randomized controlled trials and the Newcastle-Ottawa scale for retrospective studies. A meta-analysis was performed using a random or fixed effect model according to the heterogeneity.

RESULTS

Thirteen studies with 586 patients and 607 operation levels were included. The mean single-level operative time, hospital stay, and follow-up duration were 61.10 minutes, 2.32 days, and 14.7 months, respectively. At the final follow-up visit, the mean VAS score for leg pain had decreased from 7.23 preoperatively to 1.83 postoperatively, the mean VAS score for back pain had decreased from 6.30 to 1.95, and the mean Oswestry disability index had significantly improved from 56.99 to 17.83. The average satisfied outcome (excellent or good using the Macnab criteria) was 86%. The overall complication rate was 5%, and the most common complication was a dural tear, with an incidence of 2%, followed by epidural hematoma with an incidence of 1%. The remaining complications were nerve root injury, inadequate decompression, and postoperative headache.

CONCLUSIONS

From the available clinical results and experience from reported studies, UBESS for LSS is a feasible and effective approach and a worthwhile choice for clinicians. However, the complications associated with the procedure should also be seriously considered.

Topical hemostatic agents in neurosurgery, a comprehensive review: 15 years update

Hemostasis in neurosurgery is of utmost importance. Bleeding management is one of the crucial steps of each neurosurgical procedure. Several strategies, namely thermal, mechanical, electric, and chemical, have been advocated to face blood loss within the surgical field. Over time, countless hemostatic agents and devices have been proposed. Furthermore, the ever-growing recent technological innovation has made available several novel and interesting tools. Pursuant to their impact on surgical practice, we perceived the imperative to update our previous disclosure paper. Therefore, we reviewed the literature and analyzed technical data sheets of each product in order to provide an updated and comprehensive overview in regard to chemical properties, mechanisms of action, use, complications, tricks, and pitfalls of topical hemostatic agents.

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.

The histopathological effects of reabsorbable polyethylene glycol hydrogel (Coseal) on epidural fibrosis in an experimental postlaminectomy model in rats

Background/aim

To investigate the histopathological effects of reabsorbable polyethylene glycol hydrogel (RPGH, Coseal) on epidural fibrosis (EF) following laminectomy in rats.

Materials and methods

A total of 24 rats were equally divided into three groups. In the first group, no treatment was applied after laminectomy (control group, Group 1). In the second group, hemostasis was achieved after laminectomy, and 2 mm absorbable gelatin sponge soaked in saline was placed over the epidural space and the wound was closed (Group 2). In the third group, hemostasis was achieved following laminectomy, and 0.5 mL RPGH (Coseal, Group 3) was squeezed over the dura mater, and the wound was closed. A histopathological examination was undertaken to evaluate arachnoidal invasion and EF.

Results

The results of EF in the Group 2 and Group 3 were significantly lower compared to the Group 1 (p = 0.023 and p = 0.002, respectively). No statistically significant difference was found between the Group 2 and Group 3 in terms of EF (p = 0.957). There was also no statistically significant difference between the mean arachnoidal invasion of the three groups (p > 0.171). However, the rate of arachnoidal invasion was the lowest in the Group 3.

Conclusion

Intraoperative Coseal, a polyethylene glycol polymer, tends to reduce the risk of epidural fibrosis, although this is not statistically significant.

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.

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.

Immunohistochemical Grading of Epidural Fibrosis with CD105 Antibody

OBJECTIVE

Grading of epidural fibrosis (EF) is usually performed by histopathologic staining in experimental studies. Immunohistochemical methods for grading are not available in routine practice yet. In our study, the effect of tranexamic acid (TXA), a commonly used hemostatic agent in surgical interventions, was evaluated for use against the development of EF with classical histopathologic methods and immunohistochemistry using the CD105 antibody, a marker of angiogenesis.

METHODS

Sixteen rats were used. The rats were assigned to 2 groups, control and TXA. Laminectomy was performed on the control group. In the treatment group, laminectomy + topical TXA was applied. After sacrificing the rats in the sixth week, histopathologic and immunohistochemical examinations and grading of the EF tissue were performed.

RESULTS

Conventional histopathologic parameters of fibroblast count, intensity of fibrosis density, and inflammatory cell density, as well as immunohistochemical evaluation with CD105, showed that the grading of EF was comparable between groups I and II (P < 0.001).

DISCUSSION

The results of our study have demonstrated that CD105 is compatible with the conventional histopathologic grading methods and can be used as a marker to determine the grades of angiogenesis and fibrosis in experimental studies. The results of our study have also shown that TXA, administered locally for hemostasis, reduces the grade of EF in rats following laminectomy. TXA has been observed to cause no toxic effects on neural tissue as it is already commonly used in clinical practice.

Effect of platelet-rich fibrin on epidural fibrosis and comparison to ADCON® Gel and hyaluronic acid

Objective

In this experimental study, PRF (Platelet Rich Fibrin), HA (Hyaluronic Acid) gel and ADCON® Gel were compared in terms of preventing epidural fibrosis.

Methods

Twenty-eight Sprague–Dawley rats (mean weight, 400–450 g) were divided into 4 groups. L3-L4 laminectomy was performed in each group. Following laminectomy, Adcon® Gel, HA gel and PRF were applied onto the surgery site locally in Group 1, 2 and 3, respectively. Group 4 was maintained as control without any local application. After five weeks, L3-L4 vertebrae were removed totally and taken to histopathological evaluation for epidural fibrosis, acute inflammatory cell density, chronic inflammatory cell density, hemorrhage, angiogenesis and new bone formation.

Results

Acute inflammation cell density, angiogenesis, and new bone formation levels were comparable among the study groups (p > 0.05). However, new bone formation was higher in the PRF group. Epidural fibrosis and chronic inflammatory cell density were significantly lower in the PRF group (p < 0.05).

Conclusion

We concluded that PRF contributed to hemostasis and prevented epidural fibrosis.

Topping Phenomenon with Recurrent Spinal Stenosis and Epidural Fibrosis Prevented with Oxidized Cellulose - a Case Report

Lumbar spinal stenosis is a condition where the neural structures are compressed in the narrowed spinal canal and often situated only within a single specific segment of the spine, most frequently in the lumbar spine. A case report demonstrates a surgical solution of lumbar spinal stenosis with using oxidized cellulose as a prevention of post-operative adhesions and failed back syndrome. A female patient (68) with a significant pain of the lumbar spine lasting for a number of months due to advanced spondylosis, failing to respond to conservative treatment underwent instrumented, posterolateral fusion of affected segments. The patient re-arrived with pain due to spinal stenosis in another segments after 4 and then after 3 years. We repeatedly performed spinal fusion of the affected segments and applied an antiadhesive gel to the dural sac and the decompressed nerve roots to prevent the development of post-operative adhesions and the "failed back syndrome". Last surgical solution included mobilisation of the simultaneously constricted dural sac through laminectomy. This time we covered the sac using a haemostat made of oxidized cellulose (Traumacel FAM). After this treatment, the patient was again without significant difficulties.

Impact of sorafenib on epidural fibrosis: An immunohistochemical study

AIM

To determine if sorafenib, an antineoplastic agent, could prevent the development of spinal epidural fibrosis (EF).

METHODS

The study used CD105 and osteopontin antibodies in an immunohistochemical approach to quantify EF that occurred as a consequence of laminectomy in rats. Wistar albino rats (n = 16) were divided into two groups: control (L1-2 level laminectomy only) and sorafenib treatment (L1-2 level laminectomy + topical sorafenib). The animals were euthanatized after 6 wk, and the EF tissues were examined for histopathological changes after immunohistochemical staining. The EF grades were assigned to the tissues, and the treatment and control groups were compared.

RESULTS

The EF thickness, inflammatory cell density, and arachnoid adherences determined by light microscopy were significantly higher in the control group compared to the sorafenib-treated group. Based on fibrosis scores, the extent of EF in the treatment group was significantly lower than in the controls. Immunohistochemical staining for CD105 to identify microvessels revealed that the EF grades based on vessel count were significantly lower in the treatment group. Staining for osteopontin did not show any significant differences between the groups in terms of the extent of EF. The staging of EF based on vascular counts observed after immunohistochemical staining for CD105, but not for osteopontin, was compatible with conventional staging methods. Neither toxic effects on tissues nor systemic side effects were observed with the use of sorafenib.

CONCLUSION

Local administration of sorafenib significantly reduced post-laminectomy EF. Decreased neovascularization in spinal tissue may be due to the sorafenib-induced inhibition of vascular endothelial growth factor.

Does topical hemostatic agent (Floseal®) have a long-term adverse effect on erectile function recovery after nerve-sparing robot-assisted radical prostatectomy?

OBJECTIVES

To investigate the long-term effects of Floseal^® on erectile function recovery (EFR) after nerve-sparing robot-assisted radical prostatectomy (RALP).

METHODS

We prospectively collected results of the self-administered International Index Erectile Function Questionnaire 1-5 and 15 (IIEF 1-5 and 15) of 532 consecutive patients who underwent RALP for prostate cancer in our institution between October 2007 and December 2015. Patients were divided into two groups according to Floseal^® application after prostatectomy. They were enrolled according to the following criteria: (a) bilateral nerve-sparing procedure; (b) preoperative IIEF ≥ 17; adherence to our erectile rehabilitation protocol; (c) 1-year follow-up. Outcomes were measured as mean IIEF score, EFR (IIEF < 17 or ≥17), grade of ED: severe (IIEF < 17), moderate (17-21), mild (22-25) and no ED (>25).

RESULTS

A total of 120 patients were enrolled. Group A included 40 consecutive patients who received traditional hemostasis, and Group B included 80 consecutive patients in which Floseal^® was additionally used. No differences were observed in terms of preoperative mean IIEF score (p = 0.65). Group B patients showed a trend toward a higher mean IIEF score 3 months after surgery (p = 0.06) but no differences in terms of EFR (p = 1.000). Long-term results (6, 9, 12 months after surgery) showed a significantly and progressively higher mean IIEF score (p = 0.04, 0.003, 0.003) and EFR (p = 0.043, 0.027, 0.004) in Group A patients. Comparison between the groups in terms of severe, moderate, mild and no ED becomes significant at 9 and 12 months (p = 0.002, 0.006).

CONCLUSION

The results of our study suggest that local use of Floseal^® worsens the long-term erectile function recovery in patients selected for nerve-sparing RALP.