Full Heparinization Research Articles

Recombinant factor VIIa while on extracorporeal membrane oxygenator support: a word of caution

We read with interest the article by Chapman et al. [1]. They showed that patients receiving recombinant factor VIIa (rFVIIa) for intractable bleeding after cardiac surgery are not at an increased risk of thromboembolic events. Therefore, they concluded that this effective haemostatic agent can be used with an acceptable safety profile in this patient population. We would like to ask the authors whether, among the 236 patients receiving rFVIIa, they had patients supported by extracorporeal membrane oxygenator (ECMO). Bleeding is a major problem in postoperative ECMO implantation for post-cardiotomy cardiogenic shock [2]. Severe haemorrhage requiring re-exploration occurs in up to 58% of cases [3] and carries a dismal prognosis. Among patients who returned to the operating theatre, a surgical source of bleeding is not identified in more than half of the patients [1]. Hence, the off-label use of rFVIIa represents an attractive haemostatic agent for controlling bleeding attributed to a disseminated intravascular coagulation-like phenomenon [4]. We entirely agree with their opinion about the effectiveness of rFVIIa as a haemostatic agent, and we would like to report an exceptional thrombotic complication that we recently encountered: a native non-calcified aortic valve thrombosis in a patient on ECMO support who received rFVIIa for massive bleeding after coronary artery bypass grafting (CABG) surgery. A 60-year old male patient was admitted on an elective basis for CABG surgery. His past medical history included hypertension and multiple sclerosis. Coronary angiogram revealed triple vessel disease. Transthoracic echocardiography disclosed a normal aortic valve and an ejection fraction at 45%. The patient had a normal hepatic and renal function and a normal coagulation profile before surgery. Cardiopulmonary bypass (CPB) was established through median sternotomy. The obtuse marginal artery was not identified during surgery due to severe adherence between the lateral aspect of the left ventricle and the pericardium while the right coronary artery and the left anterior descending artery were bypassed. Weaning from CPB was unsuccessful, and femoro-femoral ECMO was instituted. The patient was transported to the angiography laboratory where a drug eluting stent was successfully implanted in the proximal circumflex artery. Massive bleeding from the chest tube was recorded. Therefore, a 90-μg/kg of rFVIIa was infused, and bleeding decreased. Heparin infusion was commenced 18 h after the surgery. On postoperative day (POD) 1, a transoesophageal echocardiogram (TEE) revealed severely depressed contractility of the left ventricle and thrombus formation on the three cusps of the aortic valve on the aortic side. Despite full heparinization, a complete thrombosis of the aortic valve was disclosed on POD 3, and no clots were noted in the ECMO tubing. His family refused permission for further treatment and he died after the removal of the support. In view of our experience with this drug, we recommend caution when rFVIIa is used in the postoperative period after cardiac surgery in the setting of ECMO support; careful patient management by routinely performing TEE and maintaining inotropic support for ventricular contractility and cusps mobility is mandatory to prevent thrombus formation on the aortic cusps.

Lung transplant surgery on cardiocirculatory support: Extracorporal membrane oxygenation outcompetes cardiopulmonary bypass

Objectives: In early 2010, we changed our standard for implementation of cardiopulmonary bypass in lung transplantation (LuTx). Before March 2010, standard cardiopulmonary bypass (CPB) was used after full heparinization (ACT >400s) and central cannulation in selected patients with severe pulmonary artery hypertension (PHT) or other important reasons for the use of CPB. After March 2010 all patients undergoing LuTx and fulfilling the same criteria received extracorporeal membrane oxygenation (ECMO) after single bolus injection of 5000 IE heparine and femoral arterial and venous transcutaneous cannulation. Here, we wished to analyze the impact of this change of strategy on outcome. Methods: Between 08/2008 and 02/2010, 43 consecutive patients underwent LuTx with CPB and thereafter 41 consecutive patients with ECMO. In 2009 (CPB era), 44.4% of all LuTx were performed on cardiocirculatory support. In the ECMO era, this percentage was 38.7%. Preoperatively, more ECMO than CPB patients had primary PHT (44 vs. 12%, p=0.002), were admitted to the intensive care unit (ICU) (34 vs. 12%, p=0.01), or already had ECMO support before surgery (29 vs. 12%, p=0.04). More ECMO than CPB patients underwent minimally invasive surgery (76 vs. 46%, p=0.006) and left the OR with running veno-arterial ECMO support (46 vs. 2%, p<0.001). Results: Intra-operatively, CPB patients required more blood transfusions (12±11 vs. 7±8 units, p=0.01) and platelet concentrates (2.5±1.6 vs. 1.4±1 bags, p<0.001). Postoperatively, more CPB patients needed secondary ECMO (28 vs. 5%, p=0.005) or presented acute renal failure requiring dialysis (42 vs. 14%, p=0.006). CPB patients showed, even if not statistically significant, longer mechanical ventilation and ICU times (days) (19±27 vs. 15±20, p=0.4 and 27±31 vs. 20±19, p=0.2, respectively), a higher incidence of rethoracotomy for bleeding (37% vs. 22%, p=0.1) and higher primary graft dysfunction scores (PGD) at 24 hours (PGD 2–3: 39% vs. 34%, p=0.4). After a mean follow-up of 12±11 months, survival at 1, 3 and 9 months was 79±6 vs. 98±2%, 70±7 vs. 84±6% and 58±7 vs. 84±6%, in the CPB and ECMO groups, respectively (p=0.006). Conclusions: The intra-operative use of ECMO in LuTx to substitute CPB is a superior alternative and allows for better postoperative hemodynamic and respiratory management especially in critically ill patients, such as those with primary PHT. Moreover, it confers a survival benefit and reduces postoperative complications.

Abrupt formation of intracardiac thrombus during cardiopulmonary bypass with full heparinization -A case report-

Intracardiac thrombus during cardiopulmonary bypass (CPB) with full heparinization is very rare but fatal. A 60-year-old woman was scheduled for aortic and mitral valve repairs with a maze procedure for mixed aortic and mitral valvular heart disease with atrial fibrillation. Preoperative transthoracic echocardiography and cardiac computed tomography showed moderate aortic regurgitation and moderate mitral stenosis with regurgitation. There was no intracardiac thrombus. Aortic and mitral valve repairs with the maze procedure were successfully performed without unexpected events. During CPB weaning, a mobile hyper-echogenic mass in the left atrium was detected on transesophageal echocardiography. After cardiac arrest, it was surgically removed. On completion of the operation, weaning from CPB was accomplished uneventfully. The patient fully recovered and was discharged from the intensive care unit on her third postoperative day.

Formation of intracardiac thrombus during cardiopulmonary bypass despite full heparinization and adequate activated clotting time -A case report-

We reports a case of a newly formed thrombus in the left atrial appendage during cardiopulmonary bypass detected by transesophageal echocardiography in a patient with chronic atrial fibrillation and mitral stenosis. This case alerts the anesthesiologists of possible thrombus formation despite full heparinization during cardiac surgery and the importance of a comprehensive echocardiography examination.

Neuraxial Anesthesia and Timing of Heparin Administration in Patients Undergoing Surgery for Congenital Heart Disease Using Cardiopulmonary Bypass

The goal of this review was to add to the existing literature documenting the safety of performing neuraxial techniques in patients who are subsequently fully heparinized, with particular emphasis on the timing of heparin administration. This will help improve risk estimation and possibly lead to a more widespread use of neuraxial anesthesia in patients undergoing cardiac surgery. Retrospective chart review. Single tertiary-care university hospital. All patients undergoing surgery for congenital heart diseases during a 5-year period. The medical records of all patients undergoing surgery for congenital heart diseases during a 5-year period were reviewed for any complications related to the use of neuraxial anesthesia. Furthermore, the interval from neuraxial anesthesia to heparinization for cardiopulmonary bypass was examined. In total, 714 patients were identified who had neuraxial anesthesia administered before full heparinization for cardiopulmonary bypass. No cases of symptomatic spinal or epidural hematomas occurred. Further analysis showed that the interval from neuraxial anesthesia to full heparinization was <1 hour in 466 patients. No complications related to neuraxial anesthesia were found in a series of 714 patients undergoing surgery for congenital heart disease using cardiopulmonary bypass, including 466 patients in whom the interval from neuraxial anesthesia to full heparinization was <1 hour.

In Vivo Evaluation of a New Surfactant Polymer Coating Mimicking the Glycocalyx of Endothelial Cells

The purpose of this study was to demonstrate that a proprietary surfactant polymer (SP) coating does not adversely affect the hemodynamic performance of cardiopulmonary bypass (CPB) or gas exchange in oxygenators. The new coating was applied to a CPB circuit including cannulae, reservoir, oxygenator, and blood pump implanted into 12 pigs, divided into groups with either coated or noncoated pumps. CPB flow was maintained at a fixed level of approximately 2.4 L/min for 6 hours with full heparinization. Hemodynamic data and pump performance were recorded every hour, and blood samples were taken every 2 hours. After sacrifice, the CPB circuit and major organs were macroscopically examined. There was no significant difference in the oxygen transfer rate between the two groups. The coating did not adversely affect oxygenator inlet or outlet pressures. There was no significant difference between the two groups in microthrombi seen in the oxygenators. No thromboemboli were noted in the major organs on gross or histologic examination. In conclusion, this new SP coating did not decrease gas exchange performance, and its biocompatibility evaluations revealed no differences between coated and noncoated groups under aggressive heparin use.

Hypothermic circulatory arrest for acute traumatic aortic rupture associated with shock

Hypothermic circulatory arrest is considered to be a contraindication in acute traumatic aortic rupture (TAR) because full heparinization and hypothermia may lead to fatal bleeding if concomitant hemorrhagic injuries are present. However, in extremely emergent situations, rapid volume infusion via cardiotomy vacuums and the institution of hypothermic circulatory arrest appears to be the only method for saving patients with uncontrollable bleeding. In this study, we evaluate the feasibility of hypothermic circulatory arrest for treating patients with TAR with hemorrhagic shock. Ten patients (nine men and one woman; mean age, 35 ± 18 years), with acute TAR caused by blunt chest trauma and in a shock state, underwent surgery between 1999 and 2007. All ten patients exhibited rupture of the isthmus, and polytraumatism was frequent. Any life-threatening blood loss from other injuries was surgically treated before aortic surgery. All patients were operated on with standard cardiopulmonary bypass under hypothermic circulatory arrest. All patients received prosthetic graft replacement. The overall hospital mortality was 10.0% (1/10). One patient died of intraabdominal and pulmonary bleeding during surgery, and the other nine were discharged without complications. There was no evidence of any new or increased hemorrhagic complications during heparinization in the nine surviving patients. Mean operation and circulatory arrest times were 305 ± 44 min and 27 ± 7 min, respectively. Hypothermic circulatory arrest is feasible for saving TAR patients with unstable hemodynamics resulting from rupture, provided associated injuries are properly treated in advance.

O-032 “Y” and “X” stent-assisted coiling of wide-necked intracranial bifurcation aneurysms

PurposeStent-assisted endovascular treatment of intracranial aneurysms is currently performed in many endovascular centers. Unfortunately, some parent vessel bifurcation aneurysms are not treatable with single-stent-assisted coiling. Recently, small series presented a...

Perioperative management of partial face transplantation involving a heparin antibody-positive donor

Heparin-induced thrombocytopenia (HIT) is an immunologic condition that may lead to thrombosis. We present a case of face transplantation from a donor who had suffered a severe stroke, possibly from HIT, during cardiac surgery. The procedure was planned to include full heparinization. The anesthesia team was involved in the early planning phase and had detailed access to the donor's medical history; alternative anticoagulation for the donor and recipient was suggested so as to avoid a possible complication.

Is the ACT two minutes after heparin injection reliable?

Blood for activated clotting time (ACT) measurement to verify the effect of the initial dose of heparin before cannulation in heart surgery has traditionally been drawn 5 minutes (min) after injection of the heparin. However, there has been an increasing demand to reduce the waiting time. The aim of this study was to investigate if ACT measured 1, 2, 3 and 4 min after heparin injection is as reliable as ACT measured 5 min after heparin injection. Fifty adult patients undergoing routine cardiac surgery with a heart-lung machine. Heparinization was obtained with unfractioned porcine heparin. The ACT was measured with 5 Hemochron® Jr. machines 1, 2, 3, 4 and 5 min after the heparin injection. Full heparinization was defined as an ACT >400 seconds. At 1 and 2 min, 94% (n=47) of the ACTs were > 400. All ACTs >400 seconds after 2 min remained >400 seconds at 3, 4 and 5 min. Mean values declined from 533 to 498. ANOVA analysis showed statistically significantly higher values at 1, 2 and 3 min, compared to 5 min, but not at 4 min. However, the estimated differences were small: 3.7-36 seconds. There was no significant difference between variances for the five sample times. Standard deviation declined from 123 to 100. Values at 2 min correlated as well as those at 5 min with mean 1-5 min values. The range of the ACT values tends to diminish over time and, consequently, the reliability of the results increases. However, the difference is small and has little or no clinical relevance. Giving time for the circulation to distribute the heparin in the bloodstream, we recommend measuring the ACT two min after heparin administration.

Safety profile of tinzaparin versus subcutaneous unfractionated heparin in elderly patients with impaired renal function treated for acute deep vein thrombosis: The Innohep® in Renal Insufficiency Study (IRIS)

IntroductionTrials comparing the use of full dose unfractionated heparin (UFH) or low molecular weight heparins (LMWHs) in very elderly patients with impaired renal function are lacking. IRIS aimed to assess whether LMWH is at least as safe as UFH in this population. Materials and methodsThe study included renally impaired patients ≥70years with acute symptomatic lower limb deep vein thrombosis (DVT). Patients were randomized to initial treatment with either tinzaparin 175IU/kg once daily (n=269) or activated partial thromboplastin time-adjusted UFH twice daily (n=270). After acute management both groups received vitamin K antagonist to day 90. ResultsThe trial was stopped prematurely due to a difference in mortality favoring the UFH group (11.5 vs. 6.3%; p=0.035). Rates of clinically relevant bleedings by day 90 were similar in the tinzaparin (11.9%) and UFH (11.9%) groups, as were rates of confirmed recurrent venous thromboembolism (VTE) (2.6 vs. 1.1%; p=0.34). As the mortality difference could not be explained by bleedings or recurrent VTE, a post-hoc analysis was performed. This identified six baseline characteristics significantly correlated with mortality, of which five were over-represented in the tinzaparin group. ConclusionThe IRIS study was a challenging study involving patients (mean age 83years) usually excluded from clinical studies, but its early termination has left questions unanswered. The mortality difference observed with tinzaparin vs. UFH in elderly, renally-impaired patients with DVT cannot be explained on the basis of bleedings or recurrent VTE, and may reflect an imbalance of mortality risk factors at baseline.

Thoracic Epidural Anesthesia for Cardiac Surgery: A Randomized Trial

The addition of thoracic epidural anesthesia (TEA) to general anesthesia (GA) during cardiac surgery may have a beneficial effect on clinical outcomes. TEA in cardiac surgery, however, is controversial because the insertion of an epidural catheter in patients requiring full heparinization for cardiopulmonary bypass may lead to an epidural hematoma. The clinical effects of fast-track GA plus TEA were compared with those of with fast-track GA alone. A randomized controlled trial was conducted in 654 elective cardiac surgical patients who were randomly assigned to combined GA and TEA versus GA alone. Follow-up was at 30 days and 1 yr after surgery. The primary endpoint was 30-day survival free from myocardial infarction, pulmonary complications, renal failure, and stroke. Thirty-day survival free from myocardial infarction, pulmonary complications, renal failure, and stroke was 85.2% in the TEA group and 89.7% in the GA group (P = 0.23). At 1 yr follow-up, survival free from myocardial infarction, pulmonary complications, renal failure, and stroke was 84.6% in the TEA group and 87.2% in the GA group (P = 0.42). Postoperative pain scores were low in both groups. This study was unable to demonstrate a clinically relevant benefit of TEA on the frequency of major complications after elective cardiac surgery, compared with fast-track cardiac anesthesia without epidural anesthesia. Given the potentially devastating complications of an epidural hematoma after insertion of an epidural catheter, it is questionable whether this procedure should be applied routinely in cardiac surgical patients who require full heparinization.

A simple bypass technique for superior vena cava reconstruction☆

Superior vena cava (SVC) clamping can be required during thoracic surgery for SVC replacement or repair. In such cases, bypass techniques can be necessary to avoid hemodynamic instability, cerebral venous hypertension and hypoperfusion. Here, we report a novel and simple SVC bypass technique which does not require full systemic heparinization, specialized cannulation techniques or pumping devices and which can be applied percutaneously in the preoperative phase or intraoperatively. The preoperative shunt consisted in two Swan-Ganz catheters inserted in the jugular and femoral veins and connected by perfusion tubing with a three way stopcock. The intraoperative shunt consisted of a Pruitt(®)-catheter inserted in the left innominate vein and connected to a femoral Swan-Ganz catheter by perfusion tubing. We validated our system in seven patients undergoing SVC reconstruction. We monitored the systemic arterial blood pressures, the heart rate and vasoactive peptide requirements throughout the procedure. We also determined the neurological status and the in-hospital morbidity and mortality for each patient. Using this bypass, SVC clamping caused no hemodynamic instability, no neurological impairments and no in-hospital complications or deaths. This simple temporary SVC bypass procedure is safe and avoids hemodynamic instability and cerebral venous hypertension.

Influência do ácido épsilon aminocapróico no sangramento e na hemotransfusão pós-operatória em cirurgia valvar mitral

The epsilon aminocaproic acid is an antifibrinolytic used in cardiovascular surgery to inhibit the fibrinolysis and to reduce the bleeding after CPB. [corrected]To analyze the influence of the using of epsilon aminocaproic acid in the bleeding and in red-cell transfusion requirement in the first twenty-four hours postoperative of mitral valve surgery.Prospective studying, forty-two patients, randomized and divided in two equal groups: group #1 control and group #2--epsilon aminocaproic acid. In Group II were infused five grams of EACA in the induction of anesthesia, after full heparinization, CPB perfusate after reversal of heparin and one hour after the surgery, totaling 25 grams. In group I, saline solution was infused only in those moments.Group #1 showed average bleeding volume of 633.57 ± 305,7 ml, and Group #2, an average of 308.81 ± 210.1 ml, with significant statistic difference (P = 0.0003). Average volume of red-cell transfusion requirement in Groups 1 and 2 was, respectively, 942.86 ± 345.79 ml and 214.29 ± 330.58 ml, with significant difference (P < 0.0001).The epsilon aminocaproic acid was able to reduce the bleeding volume and the red-cell transfusion requirement in the immediate postoperative of patients submitted to mitral valve surgery.

Intraoperative angiography during microsurgical removal of arteriovenous malformations in children

Confirming the successful management of pediatric arteriovenous malformations (AVMs) requires high-quality postoperative digital subtraction angiography. Although the role of intraoperative angiography during the microsurgical removal of AVMs is well established in adults, the technique has several limitations including poor image quality, uniplanar image acquisition, and absent full heparin protection. Here, the authors report on their experience with high-quality intraoperative angiography during the surgical management of pediatric AVMs in their image-guided therapy (IGT) facility. The authors retrospectively reviewed the demographic, clinical, and radiological characteristics of 22 patients who underwent the surgical management of AVMs at the Hospital for Sick Children in Toronto, with the aid of high-quality intraoperative or immediate postresection cerebral angiography via a transfemoral approach. Between January 2000 and August 2009, 18 children (mean age 13.05 ± 4.04 years, range 4-21 years) underwent both surgical management of an AVM and intraoperative cerebral angiography at an IGT facility. An additional 4 children underwent angiography immediately after surgery in the regular operating room while under the same anesthesia. The mean AVM size was 2.55 ± 1.43 cm (range 1-6 cm) with a mean Spetzler-Martin grade of 2.27 (range 1-4). Intraoperative angiography in 4 of the 18 patients demonstrated residual AVM requiring additional resection. One patient demonstrated residual AVM on immediate postoperative angiography and underwent immediate reoperation. Successful excision of the residual AVM was confirmed on angiography the following day in that case. Procedural complications occurred in connection with 1 (3.3%) of 30 angiograms, including asymptomatic transient nonfilling of an ophthalmic artery, which was resolved on follow-up angiography. Negative intraoperative angiograms were confirmed with follow-up angiograms in 15 (93.75%) of 16 patients at a mean of 9.93 ± 5.70 months. One patient with a negative intraoperative angiogram demonstrated a tiny residual AVM on follow-up angiography at 8 months (false-negative rate 6.25%), but had a negative preoperative angiogram 1 year later in the IGT facility. No patient with a negative intraoperative angiogram required further AVM-directed treatment. Intraoperative angiography is a safe and effective adjunct to the surgical management of AVMs in children. This novel approach allows the pre-, intra-, and postoperative acquisition of high-quality images, which can help guide the resection of AVMs, especially those that are small, diffuse, or of a complex angioarchitecture.

ROTEM and multiplate – a suitable tool for POC?

The early recognition of perioperative coagulation disorders is essential to identify non-surgical reasons of bleeding, to initiate appropriate haemostatic treatment and finally to reduce perioperative blood loss. Conventional laboratory coagulation tests include prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen levels and platelet counts. Although these parameters are frequently assessed, their value has been challenged at least in the setting of acute perioperative bleeding [1]. PT and aPTT are performed in an artificial ‘in vitro’ system, i.e. in plasma separated from whole blood, which is then warmed to 37 C and buffered to a pH of 7AE4. These standardized conditions often do not reflect the patient’s situation [2]. Plasmatic ‘in vitro’ tests merely reflect the time elapsing until the activation of thrombin, but provide only marginal information about the functional state of the coagulation system (e.g. platelet function, interaction of plasmatic coagulation factors with platelets and red blood cells, clot firmness, fibrinolysis). Routine coagulation tests are mostly performed in the central laboratory, i.e. remote from the operating theatre. As a consequence, test results are often not available in time or with a considerable delay [3]. Current devices designed for point-of-care (POC) monitoring of coagulation have been designed for the assessment of coagulation directly at the bedside, so that results could be available earlier. Moreover, POC tests are usually performed in whole blood, thereby comprising interactions between cellular components (i.e. platelets and red blood cells) and plasmatic coagulation factors. Commonly used POC devices for assessment of plasmatic coagulation and platelet function are listed in Table 1. This review focuses on rotation thrombelastography (ROTEM ) as a global coagulation test and multiple electrode aggregometry (MEA, Multiplate ) for assessment of platelet function. Rotation thrombelastometry (ROTEM )

Experimental use of an elastomeric surgical sealant for arterial hemostasis and its long-term tissue response

Reliable suture line hemostasis should improve the outcome of aortic surgery. We examined the hemostatic effect and the tissue response of a novel elastomeric surgical sealant. Using porcine internal carotid arteries, we performed 16 end-to-end anastomoses with four stitches of simple interrupted sutures under full heparinization. The anastomoses were divided into two groups (eight anastomoses per group). Either novel sealant or fibrin glue was applied. The amount of bleeding was measured during the 30 s period after removing the vascular clamp. In a separate experiment, we applied the novel sealant around the abdominal aorta of rabbits (n=6) to assess the effect of the elastomeric property of the sealant on arterial wall histology. For comparison, we applied cyanoacrylate, which has no elastomeric property (n=6). A histological study was performed three months after the operation. The novel sealant prevented arterial bleeding. The amount of bleeding from the anastomoses applied with novel sealant and fibrin glue was 0.12+/-0.03 g vs. 91.8+/-16.5 g, respectively (P<0.001). Thinning of the rabbit aortic wall was observed in the cyanoacrylate-treated abdominal aorta, whereas no thinning was observed in the novel sealant group. Histological examination revealed neither cell death nor necrosis in the novel sealant group. The novel sealant effectively prevented arterial bleeding from the anastomosis under full heparinization. In addition, the elastomeric property of the sealant prevented thinning of the aortic wall. The novel sealant may be a promising hemostatic agent for arterial anastomosis.

Endoscopic application of hemostatic thrombin-gelatin matrix (FloSeal®) in anticoagulated pigs

Flexible endoscopy is the method of choice for the diagnosis and therapy of upper gastrointestinal bleeding, but there are still problems during therapy of patients with coagulation disorders. FloSeal® is a hemostatic matrix largely independent of the body's own clotting system. A newly developed endoscopic applicator for FloSeal® was tested in a survival study on pigs with impaired clotting. In a total of eight pigs ulcerous lesions Forrest Ib were induced and the bleeding stopped by applying FloSeal®. Thirty minutes before intervention six pigs were given full weight-adjusted heparinization or a maximum dose of ASS in advance. The Hb course was monitored over the next 48 hours and a postmortem examination was performed. In each case, FloSeal® was successfully applied and all bleedings could be stopped. In both groups (except the control group) spontaneous extraintestinal bleeding occurred, but in only one case in the ASS group a gastrointestinal bleeding happened. The Hb course was stable in all other animals. FloSeal® can also be used endoscopically using the applicator being presented here for the first time. It is suited for primary hemostasis of excavated sources of bleeding especially in situations where coagulation is impaired.

Heparin-Induced Thrombocytopenia: Comparison Between the Standard Gel-Particle Assay (PaGIA) and the Functional Flow Cytometric Assay.

Abstract 5060 Background Heparin-induced thrombocytopenia and thrombosis (HIT) is an immune-mediated complication that may develop in patients sensitized to heparin. Approximately 5% of patients treated with full dose heparin develop clinical HIT, with about half develop thrombosis that may be associated with severe morbidity and death. However, antibodies may be detected in up to 30% of patients. Thus, current antibody-detection methods carry certain limitations, which pose a serious clinical dilemma in the diagnosis and treatment of HIT. Objectives To compare the gel-particle immuno-assay (PaGIA) for the detection of antibodies against heparin-PF4 complex, with the functional flow cytometric assay (FCA) which determines the capacity of the patient's serum to activate platelets in the presence of heparin, similar in concept to the gold-standard, the radioactive Serotonin-release assay. Methods Sequential samples from patients clinically suspected for HIT were tested by both PaGIA and the FCA (Tomer 1997, 1999). Results 118 samples were tested. Positive: 9 (7.6%) patients tested positive by PaGIA, compared to 19 (16.1%) by the FCA. 7,out of the 9 (77.8%) PaGIA -positive samples were also positive by the FCA (relative sensitivity). Negative: 97 out of 109 gel-negative samples (89.0%) were also negative by the FCA (relative specificity). Thrombosis occurred in 3 of the 9 PaGIA-positive (33%) patients, and in 7 of the 19 FCA-positive (36.8%) patients. Of the 12 PaGIA -negative but FCA-positive patients, 4 (33%) had thrombosis. Death rate was also higher among FCA-positive (n=3) compared to PaGIA-positive (n=1) patients. Of the two PaGIA -positive but FCA-negative patients, one had APLA syndrome (APS) with chronic thrombocytopenia, and one had sepsis with cardiogenic shock and multiorgan failure. ROC-Plot: Overall, the FCA showed significantly higher correlation with the clinical presentation of HIT (4Ts score), compared to the PaGIA (AUC 0.86 vs. 0.62, p&lt;0.001) Conclusion The functional FCA demonstrates superior sensitivity and specificity compared to the antibody- detection PaGIA gel-particle assay. The feasible functional FCA (results in 1.5 hr) might be useful for initial diagnosis of HIT, and particularly for confirmation of HIT in patients with confounding presentation, including negative antibody-detection assay. Disclosures No relevant conflicts of interest to declare.

Massive axial herniation after posterior fossa infarction following vertebral artery dissection

A 35-year-old woman presented with recurrent dizziness, nausea, and headache for 2 weeks. Cranial MRI showed multiple bilateral cerebellar infarctions and caliber changes suggesting a dissection of right vertebral artery. Immediate full heparinization was performed and symptoms completely remitted after 2 days. After subsequent subacute deterioration resulting in unconsciousness 6 hours later, suboccipital craniectomy and extensive osmotic …