Microporous Polysaccharide Hemospheres Research Articles

Vascular hemostasis bandage compared to standard manual compression after cardiac catheterization in children

Femoral venous and arterial approaches are the commonly used to obtain vascular access for pediatric cardiac catheterization. Hemostasis after catheter removal is usually obtained by manual compression. However, this technique is time consuming and at times painful. Although several closure devices are available for adults, they are not widely applicable in children. To evaluate the safety and efficacy of a microporous polysaccharide hemospheres hemostasis (MPH) bandage compared to manual compression. Prospective randomized study, involving 112 children after cardiac catheterization. One group received the MPH bandage, another manual compression. Compression time was predetermined by the size of sheath plus one minute. Success was defined as no bleeding or hematoma formation. If bleeding continued, compression was continued as needed and time to hemostasis recorded. Informed consent was obtained prior to randomization. Group comparisons were performed with a Student's t, Pearson's Chi Square, and Fisher's exact test as appropriate. Fewer children required a compression time of >15 min (P = 0.006) and more had a shorter time to hemostasis (P = 0.003) in the MPH group for venous access control. Time to hemostasis was also shorter in the MPH (P = 0.048) in arterial access cases, but the number of children requiring a compression time >15 min was the same. Complications including hematoma formation in each group were similar. The MPH bandage allows a shorter time to achieve hemostasis compared to manual compression. This improves turnaround time and laboratory efficiency.

Commentary on “Microporous Polysaccharide Hemospheres (MPH) for Cerebral Hemostasis: A Preliminary Report”

Commentary on “Microporous Polysaccharide Hemospheres (MPH) for Cerebral Hemostasis: A Preliminary Report”

Early Experience With Combined Use of Two Plant-Based Hemostatic Agents

Bleeding from anastomoses, which is more effectively controlled with topical hemostatic agents than with sutures, has been one of the major problems in cardiovascular surgery. We describe a novel hemostatic technique using microporous polysaccharide hemosphere (Arista; Medafor Inc, Minneapolis, MN) in conjunction with a patch of oxidized regenerated cellulose (Nu-Knit; Ethicon, Johnson & Johnson, Somerville, NJ). Both of them are plant-based products and eliminate the risk of animal-borne or human-borne contaminants and have bactericidal advantages.

Nasal dressings after endoscopic sinus surgery: what and why?

Nasal dressings are commonly used following endoscopic sinus surgery in an attempt to prevent ongoing bleeding and to modulate the wound healing process. Experience with nasal dressings in the otolaryngologic literature spans more than half a century; however, despite this, there is still little agreement between surgeons on the optimal choice of nasal dressings following endoscopic sinus surgery, or whether nasal dressings are required at all. This paper briefly reviews the past research and examines recent advances in the area of nasal dressings. The ideal nasal dressing is one that is absorbable, hemostatic and improves healing. Although a number of currently available materials may address one of these features, none address all. Currently available dressings that achieve hemostasis worsen wound healing outcomes. However, recent research shows promise with microporous polysaccharide hemospheres and chitosan gel having promising effects on hemostasis, and chitosan gel showing a significant adhesion prevention effect. The sinus surgeon must be aware of the potential advantages and limitations of currently available nasal dressings. The area of wound healing and adhesion prevention remains an area of active research and more prospective controlled trials are needed to define any benefits biomaterials may have.

Radiological and histopathological comparison of microporous polysaccharide hemospheres and oxidized regenerated cellulose in the rabbit brain: a study of efficacy and safety

Topical hemostatic agents are widely used in brain surgery but they have some disadvantages such as foreign body reaction, being a focus for infection and causing artifacts in radiological examinations. The purpose of this study is to compare the effectiveness and safety of microporous polysaccharide hemospheres (MPH) with a well known agent, oxidized regenerated cellulose (ORC), histopathologically and radiologically. Standard brain lesions (4x1mm) were created in 24 hemispheres in 12 New-Zealand rabbits. Animals were divided into three groups; control, ORC and MPH. Twenty-four hours later, all rabbits magnetic resonance brain imaging. After imaging, the animals were sacrificed and the brains were removed for histopathological analysis. Histopathological analysis showed no significant difference between the groups. Radiological examination showed no significant difference between the MPH and ORC groups in terms of edema but the edema in control group was significantly prominent than MPH and ORC groups (p < 0.001). A new agent (MPH) provides safe and effective hemostasis in the brain in this study. The most important advantage of microporous polysaccharide hemospheres is their rapid clearance from the surgical field and therefore having the potential of causing less imaging artifacts.

Microporous polysaccharide hemospheres as hemostatic agents in total knee arthroplasty: a prospective randomized study

Objective To evaluate the safety and efficacy of microporous polysaccharide hemi-spheres (MPH) in controlling blood loss in total knee arthroplasty (TKA). Methods A total of 80 pa-tients with osteoarthritis who would undergo unilateral TKA were randomized prospectively into 2 equal groups. In trial group, during TKA, MPH was sprayed into the capsule and on the muscle and tendons to control bleeding. In control group, patients did not receive MPH. The blood loss (overt and occult), postoperative decrease in hemoglobin, volume of blood transfusion, time for active straight-leg raising, time for 90-degree knee flexion, range of active motion, deep vein thrombosis (DVT) and incision complications were recorded and compared between the 2 groups. Results The overt and occult blood loss and postoperative decrease in hemoglobin were lower in the trial group than in the control group. The trial group required less blood transfusion than the control group. In the range of active motion on the 7th, 15th and 19th days postoperatively, the trial group was better. In the trial group, 2 patients had wound effusion and 6 had DVT; in the control group, 2 pa-tients had wound effusion and 7 had DVT. The differences were insignificant. Conclusion Intraoperative MPH usage is safe and effective in controlling intra- and postoperative bleeding. Key words: Arthroplasty, replacement, knee; Hemostatics; Hemostasis

Effect of microporous polysaccharide hemospheres (MPH) on bleeding after endoscopic sinus surgery: Randomized controlled study

Objectives Absorbable hemostatic agents are commonly used after endoscopic sinus surgery (ESS). MPH (microporous polysaccharide hemospheres) is a novel hemostatic powder that is rapidly absorbed. The goal of this study was to examine the effects of MPH on bleeding after ESS. Study Design Randomized, controlled, single-blinded. Setting Tertiary university hospital. Subjects and Methods Patients undergoing bilateral (symmetric) ESS for CRS by the same surgeon were randomized to unilateral treatment with MPH at surgical conclusion. The untreated opposite side served as a control. All patients received standard postoperative management. Patients completed symptom diaries using visual analog scales (VAS, scored out of 100) at baseline and through postoperative day (POD) 30. Outcomes including bleeding, pain, obstruction, and nasal discharge were recorded separately for left and right sides. Results Forty patients (19 men, 21 women) with an average age of 48.3 years were included. There were no complications, and all patients were discharged home the same day. The mean bleeding score on POD one for MPH-treated sides was 22.5 vs 39.0 for untreated controls (mean reduction 16.5, P < 0.0001, 95% CI −23.2 to −9.7). The scores for bleeding at baseline and at all other post-treatment days were not significantly different ( P > 0.05). There were no other significant differences between MPH-treated and control sides in any other variables measured. Conclusion The use of MPH after ESS results in significantly less bleeding in the early postoperative period with no increase in pain, obstruction, or nasal discharge. Patients treated with MPH follow a normal postoperative recovery otherwise.

Microporous Polysaccharide Hemospheres Do Not Enhance Abdominal Infection in a Rat Model Compared with Gelatin Matrix

Residual topical hemostatic material can serve as a nidus for infection or enhance infection in an already contaminated wound. A newly approved agent, Microporous Polysaccharide Hemospheres (MPH) (Arista AH), has rapid degradation properties, which may reduce the chance of surgical site infection. With institutional approval, 170 Wister rats underwent standardized anesthesia and abdominal surgery. An Echerichia coli inoculum was added to the incision, and MPH, gelatin matrix, or no agent (control) was placed in the site. After 72 h, the animals were sacrificed, and colony-forming units (cfu)/g were counted in the harvested tissue. Application of gelatin matrix resulted in more cfu/g of tissue and an 87% infection rate, with fewer cfu/g of tissue and a 14% and 24% infection rate in the control and MPH groups, respectively. The use of MPH in this rat abdominal infection model did not enhance infection. Gelatin matrix was associated with a greater infection rate than MPH. The rapid degradation of MPH may account for these results, making it a good hemostat in the presence of infective sources.

Topical Haemostatics in Renal Trauma—An Evaluation of Four Different Substances in an Experimental Setting

Damage control is valuable in hemodynamically unstable trauma patients. To improve the hemostasis of packing, topical hemostatic agents have been suggested. The effects of such agents are unclear in trauma situations. The purpose of this study was to investigate the hemostatic capacity, and the stability of the hemostatic clot, of four substances with different mode of action in an experimental traumatic bleeding model. A standardized heminefrectomy was performed in 180 heparinized and normotensive Sprauge-Dawley rats. Four different substances were studied (separately and in combinations) in a randomized fashion: gelatin (sponge and matrix), bovine thrombin, freeze-dried recombinant factor VIIa (rFVIIa), and microporous polysaccharide hemospheres. Eight treatment groups (15 animals/group) were considered, primary endpoint was hemostasis within 20 minutes of observation. The effective treatment groups were evaluated in a second set in the same experimental model, but with a prolonged observation time after hemostasis (60 minutes) to control the stability of the clot. Those animals treated with gelatin in the comparative study, with and without thrombin or rFVIIa, obtained hemostasis. Thrombin and rFVIIa alone did not have any hemostatic capacity. Only 20% to 25% of the animals obtained hemostasis with microporous polysaccharide hemospheres alone or in combination with rFVIIa. In the prolonged observation study, gelatin alone and in combination with thrombin or rFVIIa was studied. On average, 34% (20%-54%) of the animals rebled with no significant difference between the treatment groups. Gelatin-containing products provided a fast hemostasis in this experimental model. One third of the animals rebled, regardless of whether thrombin or rFVIIa was added. Further studies are demanded to confirm these results clinically.

COMPARATIVE SAFETY AND EFFICACY OF TOPICAL HEMOSTATIC AGENTS IN A RAT NEUROSURGICAL MODEL

Adequate hemostasis is extremely important in neurosurgery, commonly requiring the use of topical hemostatic agents. Apart from variable efficacy, the residual presence of these agents may cause foreign body reaction, infection, and delayed bone growth. This study compares the safety and efficacy of commonly used agents with a newly approved agent, Arista (microporous polysaccharide hemospheres; Medafor, Inc., Minneapolis, MN). A brain tissue defect was created in 228 Wistar outbred rats, and either no agent (negative control), Arista, Surgicel (oxidized cellulose; Ethicon, Inc., Somerville, NJ), Avitene (microfibrillar collagen; Alcon, Inc., Humacao, PR), FloSeal (gelatin matrix thrombin sealant; Baxter Healthcare Corp., Deerfield, IL), or kaolin (positive control) was implanted. Time to hemostasis was documented. The animals were sacrificed at different intervals up to 28 days, and presence of residual material and foreign body reaction was determined. Arista, Avitene, FloSeal, and Surgicel performed better (defined as complete hemostasis within 1 minute) than control (no treatment). Residual material was not present at any time with Arista, markedly contrasting with the presence of residual material in 100% of lesions in the Avitene, FloSeal, and Surgicel groups on Day 14. Avitene and FloSeal also demonstrated a propensity for causing granuloma formation, whereas Arista and Surgicel showed no such evidence. Each of these hemostatic agents was effective in controlling bleeding in the majority of standardized neurosurgical lesions. Arista degrades more rapidly than Surgicel, Avitene, and FloSeal and does not result in any foreign body reaction.

Hemostatic Agent Microporous Polysaccharide Hemospheres (MPH) Does Not Affect Healing or Intact Sinus Mucosa

Absorbable hemostatic agents are used routinely following sinus surgery. Recent studies suggest that current biomaterials, such as FloSeal Matrix Hemostatic Sealant (Fusion Medical Technologies, Mountain View, CA) may interfere with mucosal regeneration. This study was designed to evaluate the effects of Microporous Polysaccharide Hemospheres (MPH, Medafor, Inc., Minneapolis, MN), a novel rapidly-absorbing hemostatic powder, on healing and intact sinus mucosa. Prospective, controlled study using the rabbit model. Both maxillary sinuses of 14 New Zealand white rabbits were surgically opened. The mucosa of 10 rabbits were stripped bilaterally, and the left sinus of each was then treated with either MPH or FloSeal. The mucosa of four additional rabbits were incised but otherwise remained undisturbed. Again, the left sinus of each of the four additional rabbits was treated with either MPH or FloSeal. The right sinus served as an untreated control (stripped or intact) in both arms of the study. Animals were recovered and euthanized 2 weeks later. Specimens were examined by a blinded pathologist using light microscopy. Untreated regenerated mucosa showed expected areas of sparse cilia, mild serous gland reduction, and fibrosis. MPH-treated sinuses showed no significant changes compared to respective controls, and no MPH substance was identified. In contrast, regenerating mucosa treated with FloSeal showed extensive loss of cilia, inflammation, and fibrosis. Residual FloSeal particles were present within the sinus cavity and grossly incorporated within healing mucosa. Unexpectedly, intact mucosa exposed to FloSeal showed similar findings. Absorbable hemostatic materials have starkly different effects on mucosal healing. Unlike other agents, MPH is rapidly cleared and has no negative effects on healing or intact sinus mucosa.

Renal Injury and the Application of Polysaccharide Hemospheres: A Laparoscopic Experimental Model

Microporous polysaccharide hemospheres (MPH) are hemostatic beads engineered from purified plant starch. MPH accelerates the natural clotting cascade by concentrating clotting factors and proteins on their surface while absorbing aqueous and low molecular weight components from blood. The purpose of this study was to determine the efficacy of MPH in achieving hemostasis in the setting of laparoscopic renal injury. In four domestic pigs, 16 laparoscopic renal trocar injuries were created (8 each of 12 and 5 mm). A standard hand-assisted laparoscopic approach was used to each kidney so that two lesions per kidney were randomly created. MPH was applied to each treatment lesion with light pressure maintained for 60 seconds. Four of the 16 lesions, two each of 12 and 5 mm, were allowed to bleed as controls. Hemostasis was defined as no active bleeding or oozing. The animals were sacrificed at the conclusion of the procedure. The mean time to hemostasis for the 12-mm MPH and control lesions was 196.2 +/- 53.3 and 372.0 +/- 225.6 seconds, while the average blood loss was 8.3 +/- 3.7 and 12.0 +/- 4.9 g, respectively. For the 5-mm MPH and control lesions, the average time to hemostasis was 100.2 +/- 24.8 and 247.0 +/- 134.4 seconds, while the average blood loss was 8.3 +/- 3.8 and 9.0 +/- 0.7 g, respectively. The median number of applications of the MPH for the 5- and 12-mm injuries was 1 and 2, respectively. MPH provided a rapid and effective means of hemostasis for laparoscopic renal parenchymal injuries in this model. Additional evaluation is warranted, however, before general application is advisable.

Microporous Polysaccharide Hemospheres Do Not Inhibit Bone Healing Compared to Bone Wax or Microfibrillar Collagen

Topical hemostats may reduce bone bleeding but the presence of residual matter may inhibit bone growth. We compared a recently approved hemostat, microporous polysaccharide hemospheres (Arista AH, Medafor Inc, Minneapolis, Minnesota), with conventional hemostatic agents in a rabbit calvarial model. Standard defects were created and microfibrillar collagen (Avitene; C.R. Bard Inc, Murray Hill, New Jersey), bonewax, or microporous polysaccharide hemospheres was applied. Bone growth was evaluated after fluorescent labeling the mineralization front. At 7 weeks bonewax and microfibrillar collagen had reduced bone growth compared to control or microporous polysaccharide hemospheres. Microporous polysaccharide hemospheres and control animals also had reduced rabbit calvarial defects compared to bonewax or microfibrillar collagen.

Microporous polysaccharide hemospheres for management of laparoscopic trocar injury to the spleen

Background Management of iatrogenic injuries during laparoscopy can be arduous. Recent advancements in surgical hemostatic agents have provided beneficial therapeutic alternatives. This project evaluates microporous polysaccharide hemospheres (MPH), with demonstrated efficiency achieving topical hemostasis, in the setting of intracorporeal laparoscopic splenic injury. Methods Four domestic female pigs were subjected to reproducible laparoscopic 12-mm and 5-mm trocar splenic injuries. Each surgery was an identical transperitoneal hand-assisted laparoscopic procedure. Hemostasis, or no bleeding after treatment, was achieved by measured dose applications of MPH. Results The MPH successfully achieved hemostasis for all splenic injuries except in 1 case, where a 12-mm lesion transected the splenic artery. The mean time to hemostasis, applications of MPH, and estimated blood loss for the 5- and 12-mm injuries were 165.3 ± 45.7 and 200.7 ± 106.5 seconds, 1.3 ± .5 applications for both, and 12.0 ± 4.6 and 17.7 ± 9.1g, respectively. Conclusions MPH represents a powerful hemostatic agent that demonstrated complete hemostasis for iatrogenic splenic injury.

Hydrophilic Polymers with Potassium Salt and Microporous Polysaccharides for Use as Hemostatic Agents

BACKGROUND Postoperative bleeding can lead to complications such as hematoma, infection, dehiscence, and an unscheduled office visit. Topical hemostatic agents can be used to aid in hemostasis. OBJECTIVE The objective is to familiarize physicians with topical hemostatic agents—hydrophilic polymers with potassium salts (Urgent QR powder) and microporous polysaccharide hemispheres (Bleed-X). METHODS Two hemostatic agents, microporous polysaccharide hemospheres and hydrophilic polymers with potassium salt, are discussed. The literature is reviewed. RESULTS Numerous types of hemostatic agents exist. Topical hemostatic agents are safe, cost-effective, and efficient. CONCLUSION Microporous polysaccharide hemospheres and hydrophilic polymers with potassium salts can be an adjunct to hemostasis after cautery and ligation. Patients can apply hemostatic agents if they experience any bleeding leading to decreased office visits. Hemostatic agents used intraoperatively shorten bleeding time and enable the physician to use less cautery. Using hemostatic agents can lead to fewer hematomas, infections, and office visits.

Hydrophilic Polymers with Potassium Salt and Microporous Polysaccharides for Use as Hemostatic Agents

Postoperative bleeding can lead to complications such as hematoma, infection, dehiscence, and an unscheduled office visit. Topical hemostatic agents can be used to aid in hemostasis. The objective is to familiarize physicians with topical hemostatic agents--hydrophilic polymers with potassium salts (Urgent QR powder) and microporous polysaccharide hemispheres (Bleed-X). Two hemostatic agents, microporous polysaccharide hemospheres and hydrophilic polymers with potassium salt, are discussed. The literature is reviewed. Numerous types of hemostatic agents exist. Topical hemostatic agents are safe, cost-effective, and efficient. Microporous polysaccharide hemospheres and hydrophilic polymers with potassium salts can be an adjunct to hemostasis after cautery and ligation. Patients can apply hemostatic agents if they experience any bleeding leading to decreased office visits. Hemostatic agents used intraoperatively shorten bleeding time and enable the physician to use less cautery. Using hemostatic agents can lead to fewer hematomas, infections, and office visits.

Hemostatic effects of Microporous Polysaccharide Hemosphere® in a rat model with severe femoral artery bleeding

An appropriate hemostatic dressing for prehospital use should lower mortality due to uncontrolled hemorrhage. In this study, the investigators explored the hemostatic effects of Microporous Polysaccharide Hemosphere (MPH) applied in a rat model with severe femoral artery bleeding. Twelve rats were randomly assigned to MPH and control groups: The femoral artery of each rat was pierced to initiate bleeding. Then, 0.25 g MPH was poured into the bleeding site. A 200-g scale weight was placed over the bleeding site for 30 sec. At 30-sec intervals, the scale weight was removed, and hemostasis was assessed visually. After 30 sec, if the bleeding had ceased, the test was scored and checked as "passed at 30 sec." If the bleeding had not stopped, the same procedures were repeated a maximum of 3 times. If hemostasis could not be achieved even after the third application, the test was scored as failed. The same sequence of procedures was repeated for the control group without use of MPH and with only standard compression. Application of MPH resulted in complete control of bleeding in 2 of 6, 4 of 6, and 6 of 6 rats at 30, 60, and 90 sec, respectively. In the control group, however, hemostasis could not be achieved in all 6 rats, even at 90 sec. The difference between the 2 groups was statistically significant (P=.007). Application of MPH and compression with a scale weight significantly decreased the time of hemostasis in the rat model with femoral arterial bleeding.

Various Local Hemostatic Agents with Different Modes of Action; an in vivo Comparative Randomized Vascular Surgical Experimental Study

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

Hemostatic Dressings for the First Responder: A Review

The military is interested in finding a hemostatic dressing that is effective in controlling hemorrhage from combat wounds, relatively inexpensive, and easy to transport. The fibrin dressing has existed for decades, but the military has been reluctant to use the dressing because it is not Food and Drug Administration approved, fairly expensive, and difficult to apply on certain wounds. Newer dressings such as the microporous polysaccharide hemosphere (TraumaDEX), mineral zeolite (QuikClot), poly-N-acetylglucosamine (HemCon), and microporous hydrogel-forming polyacrylamide (BioHemostat) dressings have addressed these deficiencies in that they are relatively inexpensive, easy to transport, and easy to apply. However, the effectiveness of these new dressings on wounds sustained in combat is still questionable according to studies and anecdotal reports from Operation Iraqi Freedom. More research is needed to draw definite conclusions about the effectiveness of these dressings in a combat setting.

EVALUATION OF MICROPOROUS POLYSACCHARIDE HEMOSPHERES AS A NOVEL HEMOSTATIC AGENT IN OPEN PARTIAL NEPHRECTOMY: FAVORABLE EXPERIMENTAL RESULTS IN THE PORCINE MODEL

Microporous polysaccharide hemospheres (MPH, Medafor, Minneapolis, Minneapolis) are a novel hemostatic agent made from purified plant starch. MPH activates the clotting cascade and hyperconcentrates platelets and coagulation proteins, while enhancing a hemostatic plug. We evaluated the hemostatic efficacy of MPH compared with standard surgical technique in a porcine open partial nephrectomy model. Standardized lower pole partial nephrectomy was consecutively performed in each kidney of 12 female pigs. Each pig was randomized to 2 groups, namely treatment with MPH application or control with the conventional surgical technique (oxidized cellulose with bolster sutures). The right kidney was harvested 1 half-hour after hemostasis was achieved and the left kidney was harvested after 7 days. Mean animal and resected renal tissue weight were comparable. Ischemic and hemostasis times were significantly decreased in the MPH treated group (2.67 and 4.67 minutes, respectively) vs the control group (8.33 and 7.75 minutes, respectively) (each p = 0.004). Blood loss was equivocal (0.88 gm in the treatment group vs 2.09 gm in the control group, p = 0.07). No hemostatic complications were noted in either group. No evidence of residual foreign material was found in the MPH group at 1 week. MPH provided rapid, effective and durable hemostasis in the porcine open partial nephrectomy model. Additional experimental and clinical evaluation is warranted to define the role of MPH assisted partial nephrectomy in humans.