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Vascular thromboxane formation in hemostasis mechanism: correlation between bleeding time and vascular TXB2 in a patient with congenital platelet cyclo-oxygenase deficiency.

We encountered a patient with congenital platelet cyclo-oxygenase deficiency with normal ability to synthesize vascular prostaglandin I2 (PGI2) and thromboxane A2 (TXA2). The patient's peripheral blood monocytes did not show cyclo-oxygenase (COX) activity, but cultured bone marrow fibroblasts showed COX activity. To determine the mechanism of primary hemostasis in this patient, we examined the effect of oral administration of aspirin (1 g) on bleeding time and thromboxane B2 (TXB2), 6-keto prostaglandin F1 alpha (6-keto-PGF1 alpha) production in the blood emerging from the incision in this patient. The bleeding time was markedly prolonged by the administration of aspirin, and this prolongation was associated with the inhibition of TXB2 in the effluent blood, which seemed to be derived from the vessel wall. These findings suggest that vascular TXA2 production plays an important role in the maintenance of hemostasis.

6-Ketoprostaglandin F1 alpha↗

A unified hypothesis for the genesis of cerebral malaria: sequestration, inflammation and hemostasis leading to microcirculatory dysfunction.

A unifying hypothesis for the genesis of cerebral malaria proposes that parasite antigens (released by replication in blood, surface molecules on parasitized erythrocytes, or merozoites) activate platelets that, in turn, contribute to the activation of the inflammatory response and increased levels of endothelial cell adhesion molecules (eCAMs). Increased levels of eCAMs result in further parasitized-erythrocyte sequestration and marked local inflammation that might disrupt the brain microvasculature, which cannot be repaired by the hemostasis system because of its procoagulant state. Disruption of the brain microvasculature can result in vascular leak and/or hemorrhaging into the brain; similar processes can occur in other vascular beds, including the lung. The blockage of functional capillaries by parasitized and/or unparasitized erythrocytes with decreased deformability or rosettes is also a key interaction between hemostasis and mechanical obstruction leading to pathogenesis. The events resulting in the development of cerebral malaria complications are multi-factorial, encompassing a dynamic interaction between three processes, thereby explaining the complexity of this deadly syndrome.

Animals↗

Image-guided acoustic hemostasis for hemorrhage in the posterior liver.

We investigated the use of ultrasound image-guided high intensity focused ultrasound (HIFU) to stop bleeding from injuries in the posterior liver. A HIFU transducer with focal length of 3.5 cm and frequency of 3.2 MHz was integrated with an intraoperative high-resolution ultrasound-imaging probe. Wedge tissue extractions, 30-mm long, 5-mm wide and 8-mm deep, were made in the posterior liver surface of five pigs to induce bleeding. The device was positioned on the anterior surface of the liver and HIFU was applied using ultrasound image-guidance. Hemostasis was achieved in 66 +/- 18 s (mean +/- standard deviation) for 17 HIFU treatments. During 7 min of sham HIFU treatment, none of the control incisions (n = 7) became hemostatic. Ultrasound image-guided HIFU offers a promising method for hemostasis in surgical settings in which the hemorrhage site is hidden and/or not accessible.

Animals↗

Hemostasis success rates and local complications with collagen after femoral access for cardiac catheterization: analysis of 6007 published patients.

Since the first clinical studies regarding sealing of arterial puncture sites with collagen with the use of the vascular hemostatic device (VHD) and the hemostatic puncture closing device (HPCD) in the early 1990s were performed, no analysis summarizing the published patients has been reported. Therefore we performed a Medline search of data as far back as 1990 and included abstracts presented at the major scientific meetings in the United States (American Heart Association, American College of Cardiology), Europe (European Society of Cardiology), and Germany (German Society of Cardiology). A total of 6007 patients were found to have been enrolled in studies with VHD (4448 patients) or with HPCD (1559 patients). Parameters analyzed in this review were hemostasis success rates and local complications. To assess the impact of the sealing devices on local complications, studies without control groups were excluded. The hemostasis success rates immediately after deployment seemed to be higher for HPCD, but at 2' to 5' after sheath removal, they were in the same range for VHD and HPCD. In controlled studies minor local complications occurred at a rate of 7.6% in the VHD group and in 6.7% of the HPCD group. Because the control group in the HPCD studies showed a considerably higher rate of minor complications than the VHD group (11.7% vs 5.7%), the reduction in minor complications was statistically significant for HPCD, whereas VHD did not reduce minor local complications. Major local complications were reported in 3.8% of the VHD group but in only 1.8% of the HPCD group. The increase of major local complications was statistically significant with VHD (control, 1.7%) but not with HPCD (control, 1.4%). Our analysis shows that some differences between collagen devices may exist, but neither device has been proven to reduce major local complications.

Cardiac Catheterization↗

Randomized, prospective study of cyanoacrylate injection, sclerotherapy, or rubber band ligation for endoscopic hemostasis of bleeding canine gastric varices.

The purpose of this randomized, nonblinded study was to compare the effectiveness, safety, and technical ease of three different endoscopic techniques for the treatment of bleeding gastric varices in a canine model. Twenty dogs with large, bleeding gastric varices underwent endoscopic hemostasis with rubber band ligation, sclerotherapy, and cyanoacrylate injection. The time and number of attempts required to achieve definitive hemostasis were evaluated for each technique, and each method was assessed for ease of use. Ulceration rates, ulcer size and depth, and stigmata of ulcer hemorrhage were assessed at 1 week. Intravariceal sclerotherapy was the fastest and easiest to perform. Rubber band ligation was intermediate in technical ease, but it caused the largest and deepest ulcers and had the highest rates of stigmata of ulcer hemorrhage and secondary bleeding. Cyanoacrylate injection was the most cumbersome endoscopic method to perform. All three treatments were effective for controlling gastric variceal bleeding. Intravariceal sclerotherapy had the most favorable results overall because of its technical ease, efficacy, and modest complication rates.

Animals↗

Progestin-regulated expression of tissue factor in decidual cells: implications in endometrial hemostasis, menstruation and angiogenesis.

Expression of tissue factor (TF), the primary initiator of hemostasis via thrombin formation, is induced during progesterone (P4)-stimulated decidualization of human endometrial stromal cells (HESCs), and remains elevated in decidualized HESCs of luteal and gestational endometrium. In HESC monolayers, progestins elevate TF mRNA and protein levels and estradiol (E2) plus progestin further enhance TF levels for weeks despite no response to E2 alone. This in vitro model mimics the chronic differential ovarian steroid upregulation of TF levels associated with in vivo decidualization. After incubation of HESCs with E2 plus progestin to elevate TF expression, the antiprogestin RU486 completely reversed this upregulation. Thus, progesterone withdrawal transformed decidualization-associated hemostasis of the luteal phase endometrium to the hemorrhagic milieu of menstruation. Transient transfections with TF promoter constructs containing SP and EGR-1 binding sites before and after inactivation by site-directed mutagenesis revealed that Sp1 mediates basal and progestin-enhanced TF transcriptional activity. Progesterone receptor involvement in TF expression was further confirmed since RU486 was a pure antagonist of progestin-enhanced TF mRNA and protein expression, and progestin-enhanced, but not basal, Sp1-mediated transcriptional activity. Enhanced TF mRNA and protein levels in HESCs require co-incubation with progestin and epidermal growth factor receptor (EGFR) agonist indicating that the EGFR mediates progestin-enhanced TF expression. A peak in the primary angiogenic agent, vascular endothelial growth factor (VEGF) in luteal phase endometrium may be indirectly regulated by P4. Neither E2, nor progestin, nor E2 plus progestin affected VEGF expression in glandular epithelial and stromal cells, whereas thrombin enhanced VEGF mRNA and protein levels in decidualized HESCs, but not in the epithelial cells. Transudation of clotting factors to perivascular decidual cell TF in the luteal phase would generate thrombin, enabling it to act as an autocrine enhancer of VEGF in decidualized HESCs. Abnormal uterine bleeding complicates long-term progestin only contraceptive use. After Norplant administration, endometrial VEGF levels are elevated and TF levels are selectively enhanced in decidualized HESCs at bleeding sites. Over-expressed VEGF causes blood vessels to become leaky, increasing clotting factor access to decidualized HESC-expressed TF to promote feed-forward thrombin and VEGF formation. Since thrombin and VEGF induce angiogenesis via separate endothelial cell receptors, they may synergize to elicit aberrant angiogenesis, and ultimately lead to focal bleeding.

Decidua↗

The scrotal hitch for hemostasis and edema prevention in scrotal surgery.

Postoperative hematoma, edema, and echymosis are the most common complications in scrotal surgery. Without proper hemostasis intraoperatively or appropriate scrotal compression postoperatively, significant morbidity, including re-exploration and prolonged convalescence, can occur. The scrotal hitch provides hemostasis, minimizes edema and hematomas, and reaffirms other clinicians' findings.

Bandages↗

Liver hemostasis using high-intensity focused ultrasound.

Liver hemorrhage, the major cause of death in hepatic trauma, is notoriously difficult to control. We report on the use of high-intensity focused ultrasound (HIFU) to arrest the bleeding from incisions made in rabbit livers. A HIFU transducer, with a spherically curved aperture of 6.34 cm2 area, a focal length of 4 cm and a frequency of 3.3 MHz was used. In approximately 94% of the incisions, the hemorrhage was reduced to a slow oozing of blood in less than 2 min. The maximum temperature of liver tissue around the incision area, during HIFU application, was measured to be 86 degrees C. The mechanism of hemostasis, confirmed by histological examination, appears to be coagulative necrosis of a volume of liver tissue around the incision. We believe that acoustic hemostasis, with the unique characteristic of "volume cauterization," offers a novel method for the management of liver hemorrhage and, thus, has major clinical implications.

Animals↗

Hemostasis changes during cardiopulmonary bypass surgery.

A number of hemostasis parameters were studied in a total of 63 patients undergoing cardiopulmonary bypass (CPB) for open heart surgery. In 33 patients fibrinogen, Factors II, V, VIII:C, X, XI, antithrombin, plasminogen, alpha 2-antiplasmin, and platelet counts were assayed before surgery, during maximal hypothermia, at the end of the bypass procedure, before and after protamine sulfate infusion, in the intensive care unit, and 48 hours postoperatively. All factors assayed decreased markedly when the patients were placed on the bypass machine, the drop fairly well paralleling the decrease in hematocrit. During bypass the factors remained low, although a slight tendency toward an increase was noted. Only platelet counts remained low with a decreasing trend until the end of bypass. In the intensive care unit a second decrease in fibrinogen, Factors II and V and antithrombin was noted. This drop was unrelated to four patients who experienced a greater blood loss during this time than the others. Forty-eight hours postoperatively, a marked increase could be found in all clotting factors and near normal levels were measured. Platelet counts remained low, however. The decrease in factors rarely dropped into a range where one would expect a compromised hemostasis (less than 30%). Although antithrombin levels decreased below 60%, no difficulties with heparinization were encountered. Several factors were assayed manually and by automated analyzer (Multistat III), and excellent correlations were found between both procedures. Also a good correlation was found between the activated whole blood clotting times and quantitative heparin assays. In 30 additional patients platelet function was studied before surgery, after thoracotomy, after heparin administration, after initiation of bypass, at maximal hypothermia, before and after protamine sulfate infusion, and 24 hours postoperatively. Platelet counts once again decreased as patients were placed on the CPB machine and remained low throughout the procedure. Mean platelet volumes were unchanged until protamine was given. At that time, a significant drop in mean platelet volume was recorded. Twenty-four hours postoperatively the volumes were normal again. Platelet aggregation studies were performed on a whole blood aggregometer using two concentrations of ADP, collagen, and ristocetin as aggregation inducers. A significant decrease in aggregability was seen when the patients were connected to the CPB apparatus.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

Endoscopic hemostasis by injection therapy and electro-hydro-coagulation in high-risk patients with active gastroduodenal bleeding ulcer.

For the purpose of arresting hemorrhage from bleeding gastric or duodenal ulcers we developed, in 28 high-risk patients, a new method of endoscopic local injection of epinephrine (1:10,000) followed by electro-hydro monopolar coagulation and injection of Polidocanol (1%). Nine patients had signs of shock at the time of admission. The average blood requirements were 3.9 units in the first 24 hours. All patients had important factors militating against surgery, namely age and serious primary disease. In 26 out of 28 patients (92.8%) hemostasis was accomplished during endoscopy. Three patients (10.7%) rebled within the first 36 hours, requiring emergency surgery. Thus definitive hemostasis was achieved in 23 patients (82.1%). There were no complications as a result of endoscopic treatment.

Aged↗

Endoscopic electrocoagulation--an alternative to operative hemostasis in active gastroduodenal bleeding?

Endoscopic electrocoagulation was considered in 69 patients with active gastroduodenal bleeding including 60 patients with peptid ulcer. Permanent hemostasis was achieved in 56 patients (81%), including 16 patients with clinical indication for surgical intervention. Electrocoagulation failed or could not be applied in 13 patients, requiring operative hemostasis in 11 patients. Though no replacing emergency, endoscopic electrocoagulation can be successful, especially if it is applied in quiescent phase of massive, life-threatening hemorrhage, and should be considered before a possible emergency operation, especially in patients with no previous ulcer disease, in the presence of some other severe illness, or in patients of advanced age.

Adolescent↗

A comparison of laparoscopic bipolar vessel sealing devices in the hemostasis of small-, medium-, and large-sized arteries.

INTRODUCTION: The development of new energy sources for hemostasis has facilitated advanced laparoscopic procedures. Few studies, however, have documented the strength of the vessels sealed or the extent of surrounding lateral thermal injury, two important factors in maintaining hemostasis while preventing injury to surrounding structures. This study compared the burst pressure and extent of thermal injury of vessels sealed with the 5-mm laparoscopic PlasmaKinetics trade mark sealer (PK) (Gyrus Medical, Maple Grove, Minnesota) and the 5-mm laparoscopic LigaSure trade mark sealing device (LS) (Valleylab, Boulder, Colorado). METHODS: Arteries in three sizes (2-3 mm, 4-5 mm, and 6-7 mm) were harvested from domestic pigs. Eight to 17 specimens from each size were randomly sealed with the PK, and the same number with the LS. Burst pressures were measured in mm Hg. The extent of thermal injury, determined by coagulation necrosis, was measured microscopically in millimeters after staining the transected vessels with hematoxylin and eosin. Descriptive statistics, including means and standard deviations, are reported. Student's t-test and ANOVA were performed to determine significance (P <.05). RESULTS: The mean bursting pressures of the PK and the LS were equal in the 2-3 mm vessels (397 vs. 326 mm Hg, P =.49). The PK bursting pressures were significantly less than the LS in the 4-5 mm (389 vs. 573 mm Hg, P =.02) and the 6-7 mm groups (317 vs. 585 mm Hg, P =.0004). As vessel size increased, the PK was associated with significantly lower burst pressures, while the LS was associated with progressively higher burst pressures (P =.035). Thermal spread was not significantly different between the PK and the LS in the 2-3 mm (1.5 vs. 1.2 mm, P =.27), the 4-5 mm (2.4 vs. 2.4 mm, P =.79), or the 6-7 mm vessel size groups (3.2 vs. 2.5 mm, P =.32). Increasing vessel size, regardless of instrument used, was associated with increased thermal injury (P <.0001). CONCLUSION: The LS produces supraphysiologic seals with significantly higher bursting pressures than the PK in vessels ranging from 4 to 7 mm. The PK seals become progressively weaker while the LS seals increase in strength as the vessel size increases. Although thermal spread increases with vessel size, the degree of lateral thermal injury is no different between the two instruments.

Animals↗

Ostene, a new water-soluble bone hemostasis agent.

Traditional formulations of bone wax are composed largely of beeswax and are well known to interfere with bone healing and cause inflammatory reactions. Ostene, a newly available bone hemostasis agent made of water-soluble alkylene oxide copolymers, was evaluated. The soft tissue response to Ostene was compared with bone wax and a polyethylene control after implantation into the paravertebral muscles of three rabbits. After 2 weeks, Ostene elicited no fibrous response, the polyethylene elicited a thin (less than 0.5 mm) fibrous response, and the bone wax was encased in a fibrous capsule 0.6 to 1.0 mm thick infiltrated with inflammatory cells. The effects of Ostene were compared with bone wax in a femur defect model in eight rabbits. Ostene showed no evidence of an adverse response in the cortical defect site, medullary cavity, or the surrounding tissue at 4 and 8 weeks. In contrast, bone wax at both time intervals elicited a foreign body response consisting of fibrous tissue infiltrated by macrophages, giant cells, and lymphocytes at the sites of the bone defects. Bone wax also displaced the bone marrow and interfered with bone ingrowth into the defects. Ostene provides the clinician a water-soluble bone hemostasis material that does not demonstrate the adverse tissue response or the interference with bone healing seen with the use of bone wax.

Animals↗

The argon beam coagulator provides rapid hemostasis of experimental hepatic and splenic hemorrhage in anticoagulated dogs.

The argon beam coagulator (ABC) delivers radiofrequency electrical energy to tissue across a jet of argon gas, providing noncontact, monopolar, electrothermal hemostasis. This study compared the efficacy of the ABC with conventional techniques for control of traumatic hepatic and splenic hemorrhage. Standardized lacerations were made to the liver and spleen of 6 heparinized dogs. Control of bleeding was attempted with the ABC (150 W), the Nd:YAG laser (90 W, noncontact), horizontal mattress suture, microcrystalline collagen, and regenerated cellulose. If bleeding had not been controlled within 3 minutes, coagulation was attempted with the ABC in order to prevent exsanguination. Tissue from both the liver and spleen was assessed histologically for damage induced by the ABC. Delayed injury and early healing after ABC coagulation was studied in six additional dogs killed 1 and 3 weeks postoperatively. The ABC stopped bleeding from 25/25 hepatic lacerations in 48 +/- 8 seconds (mean +/- SEM) and from 18/18 splenic lacerations in 28 +/- 3 seconds. The Nd:YAG laser, mattress sutures, and topical hemostatic agents failed to control bleeding in 14 of 15 applications after 3 minutes. The ABC successfully salvaged all failures in less than 1 minute. The depth of splenic and hepatic thermal injury with the ABC ranged from 2 to 7 mm and was proportional to the duration of application. Postoperatively wound healing progressed normally without bleeding or infection at the coagulation site. The ABC appears to be a excellent instrument for achieving hemostasis in solid organ injury, and may be especially valuable in managing patients with coagulation deficits.

Animals↗

Nonoperative salvage of computed tomography-diagnosed splenic injuries: utilization of angiography for triage and embolization for hemostasis.

OBJECTIVES: The aims of this study were to determine if angiographic findings can be used to predict successful nonoperative therapy of splenic injury and to determine if coil embolization of the proximal splenic artery provides effective hemostasis. METHODS: Splenic injuries detected by diagnostic imaging between 1981 and 1993 at a level I trauma center were prospectively collected and retrospectively reviewed after management by protocol that used diagnostic peritoneal lavage, computed tomography (CT), angiography, transcatheter embolization, and laparotomy. Computed tomography was performed initially or after positive diagnostic peritoneal lavage. Angiography was performed urgently in stabilized patients with CT-diagnosed splenic injuries. Patients without angiographic extravasation were treated by bed rest alone; those with angiographic extravasation underwent coil embolization of the proximal splenic artery followed by bed rest. RESULTS: Patients (172) with blunt splenic injury are the subject of this study. Twenty-two patients were initially managed operatively because of associated injuries or disease (11 patients) or because the surgeon was unwilling to attempt nonoperative therapy (11 patients) and underwent splenectomy (17 patients) or splenorrhaphy (5 patients). One hundred fifty of 172 consecutive patients (87%) with CT-diagnosed splenic injury were stable enough to be considered for nonoperative management. Eighty-seven of the 90 patients managed by bed rest alone, and 56 of 60 patients treated by splenic artery occlusion and bed rest had a successful outcome. Overall splenic salvage was 88%. It was 97% among those managed nonoperatively, including 61 grade III and grade IV splenic injuries. Sixty percent of patients received no blood transfusions. Three of 150 patients treated nonoperatively underwent delayed splenectomy for infarction (one patient) or splenic infection (two patients). CONCLUSIONS: (1) Hemodynamically stable patients with splenic injuries of all grades and no other indications for laparotomy can often be managed nonoperatively, especially when the injury is further characterized by arteriography. (2) The absence of contrast extravasation on splenic arteriography seems to be a reliable predictor of successful nonoperative management. We suggest its use to triage CT-diagnosed splenic injuries to bed rest or intervention. (3) Coil embolization of the proximal splenic artery is an effective method of hemostasis in stabilized patients with splenic injury. It expands the number of patients who can be managed nonoperatively.

Adolescent↗

Multicenter evaluation of a bilayer polymer blood collection tube for coagulation testing: effect on routine hemostasis test results and on plasma levels of coagulation activation markers.

We compared the results of different hemostasis tests obtained in an evacuated bilayer polymer tubes (Vacuette, Greiner Bio-One) and in a siliconized glass tubes containing the same citrate concentrations (0.109 M and 0.129 M). For that purpose, blood was collected in five centers from 60 untreated patients and from patients on oral anticoagulant (n = 168), unfractionated heparin (n = 111) or a low molecular weight derivative (n = 108). Test results obtained in polymer tubes were not significantly different from those in glass tubes, except for INR when a high ISI thromboplastin was used (p < 0.0001 for tubes containing 0.129 M sodium citrate) and for APTT (p < 0.05 for both citrate concentrations). However, these differences had no clinical relevance (Bland-Altman analysis). In addition, no effect of aging of the polymer tubes on the test results could be demonstrated. The plasma levels of F1+2 and TAT, measured in a subset of 30 untreated patients, were significantly lower when blood was collected in polymer than in glass tubes, for both citrate concentrations. These results suggest that samples collected into the Vacuette polymer tubes allow accurate routine hemostasis testing both in untreated patients and in patients on traditional anticoagulant treatment during the whole shelf-life indicated by the manufacturer.

Blood Coagulation Factors↗

Comparison of poly-N-acetyl glucosamine with commercially available topical hemostats for achieving hemostasis in coagulopathic models of splenic hemorrhage.

BACKGROUND: The hemostatic quality of the poly-N-acetyl glucosamine (p-GlcNAc) patch was compared with a fibrin sealant, fibrin bandage, and cellulose patch. METHODS: A 2 x 2-cm capsular strip to a depth of 3 mm of the swine spleen was used as a source of bleeding. Splenic lacerations were created in hemophilia B dogs and treated with p-GlcNAc and Surgicel. Wounds were created in rabbits and treated with p-GlcNAc at 37degreesC and after keeping body core temperature at 29degreesC. RESULTS: Poly-N-acetyl glucosamine was able to achieve hemostasis with greater efficacy than either of the fibrin-based bandages. In the hemophilia B dog study, p-GlcNAc significantly outperformed Surgicel, with p-GlcNAc achieving hemostasis in 75% of the treated wounds compared with 17% for the cellulose patch. The hypothermia study demonstrated that p-GlcNAc is equally effective at 29degreesC and at 37degreesC. CONCLUSION: Poly-N-acetyl glucosamine was effective at controlling bleeding in animals with experimentally induced or genetic coagulopathic disorders.

Acetylglucosamine↗

Randomized double-blind studies of polysaccharide gel compared with glue and other agents for hemostasis of large veins and bleeding canine esophageal or gastric varices.

BACKGROUND: The safety and efficacy of poly-N-acetyl glucosamine (p-GlcNAc) gels were compared with standard agents in three different dog studies to assess abdominal venous collaterals, bleeding esophageal varices, and bleeding gastric varices. METHODS: Adult dogs with prehepatic portal hypertension and large abdominal venous collaterals, esophageal varices, or gastric varices were studied. RESULTS: Significantly higher sclerosis rates were seen with F2 or F4 p-GlcNAc gels and standard sclerosants. F2 and F4 gels had high rates of permanent hemostasis, low rates of secondary ulceration, and significant reductions in esophageal and gastric variceal size. These results were either equivalent to or significantly better than the most commonly used gastric varix hemostatic agent (glue) or other sclerosing agents. CONCLUSION: F2 and F4 poly-N-acetyl glucosamine gels are promising therapeutic agents for venous and variceal hemostasis.

Acetylglucosamine↗