Use Of Systemic Anticoagulation Research Articles

VV extracorporeal life support for the Third Millennium: will we need anticoagulation?

Since the late 1600's medicine and science have entertained the idea of extracorporeal circulation. With this technology to allow for cardiac and pulmonary support came the development of anticoagulation. Although this advanced the technology and capabilities of extracorporeal life support, it was not without complications and risks. The most common complications in extracorporeal life support (ECLS) present day are related to hemorrhage and thrombus due to the need for systemic anticoagulation and the challenges associated with it. This review focuses on present day techniques for anticoagulation for ECLS and what future surface modifications may do to obviate the use of systemic anticoagulation entirely.

The Successful Use of Extracorporeal Membrane Oxygenation in Systemic Lupus Erythematosus-Induced Diffuse Alveolar Haemorrhage.

Diffuse alveolar haemorrhage (DAH) is a catastrophic pulmonary complication of systemic lupus erythematosus. It can result in refractory hypoxaemia despite mechanical ventilation. Increasing lung compliance and worsening pulmonary hypertension can potentiate cardiogenic shock from acute right ventricular failure. In such patients with cardiopulmonary collapse, veno-arterial (V-A) ECMO maybe a viable option that can provide the required haemodynamic support. However, the use of V-A ECMO in such patients is limited due to an associated increased risk of bleeding. Our case report describes the successful use of V-A ECMO without the use of systemic anticoagulation in a patient with DAH. Despite the absence of systemic anticoagulation, no thrombotic complications within the circuit were noted.LEARNING POINTSDiffuse alveolar haemorrhage (DAH) complicating systemic lupus erythematous can present dramatically with sudden cardiopulmonary collapse.Extracorporeal membrane oxygenation (ECMO) can provide temporary haemodynamic support until conventional medical therapy can take effect.Despite the historical increased bleeding risk associated with ECMO, it can be safely used in patients with DAH to provide time for underlying organ recovery.

Extracorporeal membrane oxygenation without systemic anticoagulation for complex multi-organ system trauma patient

Introduction: Use of ECMO has been shown to be an acceptable intervention for patients with respiratory failure refractory to optimal ventilator management. As experience with ECMO grows the indications for its use are also expanding. Case: Our patient is a 20-year-old female who was found lying on the roadside after being hit by a moving vehicle. She was rushed into the trauma room where she was intubated for low Glasgow coma scale, CT head, chest, abdomen and pelvis showed severe head injury with possible diffuse axonal injury, blunt chest injury, blunt abdominal injury with splenic injury was admitted under the care of TICU, repeat CT head showed multiple hemorrhagic contusions. Ventriculostomy with ICP monitoring device was inserted. She was aggressively treated for severe brain injury by neuroprotective interventions. Over following days had severe ARDS. Despite appropriate antibiotic therapy, lung protective ventilation, HFOV, patient had severe hypoxemia. Patient was evaluated for ECMO despite her severe neurological injury with ICH, possible poor neurological recovery. After discussions involving primary team, ECMO was considered initiated using femoral-Jugular cannulation. No systemic anticoagulation was used. Tracheostomy was placed and was weaned off ECMO over next week. ECMO decannulation was performed on 7th day. Patient had multiple interventions by the orthopaedic, weaned off decannulation in 18 days and tracheostomy was closed. Patient had neurological recovery was discharged to the rehabilitation. Discussion: ECMO is an established salvage therapy for profound respiratory failure and the need for systemic anticoagulation has often contraindicated its use in patients with severe intracranial pathology, and in particular, recent hemorrhage like our patient. Advances in circuit and oxygenator technology have challenged this concern and cases of ECMO support with intracranial pathology have been recently described. Risks and benefits of systemic anticoagulation need to be considered during ECMO support. Conclusions: Extracorporeal membrane oxygenation is an acceptable therapy for patients with profound respiratory failure secondary to trauma and intracranial pathology contraindicating the use of systemic anticoagulation.

Are our cornea waiting lists dynamic enough?

The purpose of this study was to evaluate the dynamic reality of the corneal transplant (CT) waiting list and if the CT candidates are really eager to operation. We evaluated the response of consecutive 96 CT candidates to call for operation. The age, functional visual acuity, CT indication, waiting period, and the excuse of refusal for candidates that postponed the operation were also evaluated. The patients were classified into two groups according to the availability (Group 1, available; Group 2, unavailable). To find an available candidate for transplantation of 48 consecutive corneal tissues, 96 patients had to be called. The mean age of the patients was 57.49±18.75. The mean age of Group 1 and Group 2 was 54.28±18.12 (13-80) and 60.44±19.01 (9-88) years, respectively (p=0.108). It was found that the call refusal was higher in patients elder than age 70 (p=0.04). The mean time between being added to the list and the call was 22.96±7.80 (9-39) months for Group 1, 27.02±8.25 (9-53) months for Group 2 (p=0.015). The estimation point for waiting period was 22months (p=0.044). The most common reasons of excuse were inconvenience of timing, giving up operation, and secondary health problems, whereas anticoagulant use was the most common reason for postponement. As the waiting period gets longer and CT candidates get older, they tend to give up operation. The secondary health problems and use of systemic anticoagulants are important problems that might cause postponing the CT surgery and ruin the dynamicity of the waiting lists.

A Descriptive Study of the Risk Factors Associated With Catheter-Related Bloodstream Infections in the Home Parenteral Nutrition Population.

Home parenteral nutrition (HPN) is increasingly used for nutrition support after patients are discharged from the hospital. Catheter-related bloodstream infections (CR-BSI) are a common and potentially fatal complication of HPN. The risk factors for development of CR-BSI in the outpatient setting are poorly understood. We conducted an observational, retrospective study of 225 patients discharged from Barnes-Jewish Hospital on HPN between January 1, 2007, and December 31, 2009. HPN complications were defined as any cause that led to either premature discontinuation of HPN therapy or catheter replacement. CR-BSI events were identified by provider documentation. We calculated the overall complication rate and the complication rate specifically due to CR-BSI. Backward stepwise Cox regression analyses were used to assess for independent predictors of catheter-related complications. In total, 111 of 225 patients (49%) developed complications while receiving HPN (incidence = 5.06 episodes/1000 catheter days). Sixty-eight of 225 patients (30%) required catheter removal for CR-BSI (incidence = 3.10 episodes/1000 catheter days). Independent predictors of line removal specifically due to infection included anticoagulant use, ulcer or open wound, and Medicare or Medicaid insurance. The following risk factors were associated with catheter-associated complications and/or CR-BSI: the presence of ulcers, the use of systemic anticoagulants, public insurance (Medicare or Medicaid), and patient age. Independent predictors of line removal for any complication included age and anticoagulant use. Catheter-related complications were extremely common in patients receiving HPN. Healthcare providers caring for individuals who require HPN should be aware of risk factors for complications.

Retrospective Evaluation Of Novel Percutaneous Left Atrial Appendage Ligation Using The LARIAT Suturing Device: Single Center Initial Experience.

The left atrial appendage (LAA) is the source of considerable thromboemboli responsible for embolic strokes in patients with atrial fibrillation (AF). The LARIAT™ suturing device has been used to ligate the LAA and negate the use of systemic anticoagulation. However, its efficacy and stroke outcome is still unknown. We retrospectively evaluated the clinical status and risk of occurrence of systemic emobolic events, strokes, transient ischemic attacks, and procedure related complications in patients after LAA ligation using the LARIAT™ device. Permanent suture was successfully delivered in 21 patients. Mean follow up time was 17.2+-3.3 months. The average HAS-BLED score was 3.3+/-1.1. Only 1 patient developed clinical symptoms of stroke 7 days post procedure. One patient had uncomplicated perioperative bleeding not requiring blood transfusion. One patient developed transient ECG changes of ischemia during mapping for ablation following the LAA ligation and subsequently, underwent bypass surgery. Three patient developed post-procedural pericarditis and were medically managed. Three patients died from non-LAA ligation related conditions including congestive heart failure, lung cancer, and severe coronary disease. We observed a 32% and 30% reduction in the annual risk of stroke when compared to the expected risk of stroke based on the CHADS2 and CHA2DS2-VASc score respectively. LAA ligation using the LARIAT™ suturing device is clinically feasible in carefully selected patients. This study has the longest follow up period to date, however further studies are required to determine the efficacy of stroke reduction and long-term clinical outcomes.

Response to Letter Regarding Article, “Management of Severe Mitral Stenosis During Pregnancy”

HomeCirculationVol. 126, No. 1Response to Letter Regarding Article, “Management of Severe Mitral Stenosis During Pregnancy” Free AccessReplyPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessReplyPDF/EPUBResponse to Letter Regarding Article, “Management of Severe Mitral Stenosis During Pregnancy” Rebecca S. Norrad, MBBS, BSc (Hon) and Omid Salehian, MSc, MD, FRCPC, FACC, FAHA Rebecca S. NorradRebecca S. Norrad Search for more papers by this author and Omid SalehianOmid Salehian Search for more papers by this author Originally published3 Jul 2012https://doi.org/10.1161/CIRCULATIONAHA.112.110841Circulation. 2012;126:e16We appreciate the interest shown by Dr Harikrishnan and colleagues in our article.1 We agree with them that percutaneous balloon mitral valvuloplasty in pregnant women should be reserved for those patients in whom aggressive medical therapy fails and in patients for whom the benefits of intervention outweighs its risks. Certainly decreasing the heart rate is the main goal of medical therapy in patients with symptomatic mitral stenosis. Our patient was on very high dose of metoprolol (100 mg TID) and continued to be significantly symptomatic despite complete bed rest. In our experience, further addition of atrioventricular nodal blocking agents such as digoxin would not provide significant reduction in heart rate to provide adequate improvement in valve hemodynamics and symptoms.We also agree with the importance of reduction in radiation exposure and fetal protection during the procedure. In our institution, it is routine practice to minimize fluoroscopy time, and to provide lead shielding to cover the lower abdominal segment, as well, which would not be readily visible on fluoroscopy images performed during balloon inflation. However we do routinely perform invasive hemodynamics during our valve procedures, because, in certain cases, important information can be obtained with no increase in fluoroscopy time.With respect to anticoagulation in patients with rheumatic mitral stenosis, current American College of Chest Physicians guidelines2 recommend use of systemic anticoagulation if the left atrial diameter exceeds 55 mm, even if the patient is in sinus rhythm (albeit a grade 2C recommendation). Furthermore, American College of Chest Physicians guidelines for the antithrombotic therapy in pregnancy3 recommend the use of low-molecular-weight heparin over unfractionated heparin during pregnancy because of its improved safety profile. Needless to say, anticoagulation therapy during pregnancy needs to be individualized based on the overall risk/benefit assessment, patient preferences, and availability of resources, among other things.Finally, by virtue of the fact that this article was published in the Images in Cardiovascular Medicine section of the Circulation, it is by no means meant to be comprehensive. Many areas in the care of patients with rheumatic heart disease were not covered. This case was presented to highlight some of the challenges in taking care of these patients during pregnancy.Rebecca S. Norrad, MBBS, BSc (Hon)Omid Salehian, MSc, MD, FRCPC, FACC, FAHA Division of Cardiology Department of Medicine McMaster University Hamilton, Ontario, CanadaDisclosuresNone.

The Association of Septic Thrombophlebitis with Septic Pulmonary Embolism in Adults

Background: There have been an increasing number of pediatric reports of septic pulmonary embolism in the setting of septic thrombophlebitis adjacent to a primary infectious source.Methods: Retrospective review at an urban hospital. A total of five adults with a documented primary infectious source, adjacent septic thrombophlebitis and septic pulmonary embolism were identified between 2000 and 2011.Results: The predominant symptoms on presentation were fever and pleuritic chest pain, followed by chills and cough. S. aureus was the pathogen in 4 patients. Only one case had echocardiographic evidence of endocarditis. All patients received IV antibiotics and anticoagulation therapy. No new embolic events or central nervous system complications were noted.Conclusions: The triad of extrapulmonary infection, contiguous septic thrombophlebitis and septic pulmonary embolism is present in adult as well as pediatric populations. The use of systemic anticoagulation with appropriate antibiotics resulted in clinical and radiologic improvement but no significant complications.

Treatment of Pulmonary Embolism Using Ultrasound-Accelerated Thrombolysis Directly Into Pulmonary Arteries

Traditional therapy for pulmonary embolism includes systemic anticoagulation, systemic thrombolysis, catheter-directed thrombolysis / suction catheter thrombectomy, and surgical thromboembolectomy. Currently, the standard treatment for submassive and massive pulmonary embolism involves the use of systemic anticoagulation. However, unlike systemic anticoagulation there is no standard treatment algorithm for the use of thrombolytics to aggressively treat pulmonary embolism and its sequelae. This case report discusses the successful use of thrombolytics using the EKOS EkoSonic Ultrasound-Accelerated Thrombolysis System in the treatment of bilateral submassive pulmonary emboli along with a saddle pulmonary embolus. The EKOS ultrasound-accelerated thrombolysis procedure resulted in rapid substantial clinical improvement, resolution of bilateral pulmonary emboli along with resolution of the saddle pulmonary embolus, restoration of pulmonary blood flow with resolution of pulmonary hypertension, and normalization of pulmonary embolism-related cardiac dysfunction. This novel application of ultrasound-accelerated thrombolytic infusion directly into the pulmonary arteries for pulmonary embolism provides a potential new treatment option and a valuable addition to the treatment algorithm for the management of both submassive and massive pulmonary embolism.

A review of therapeutic strategies for the management of cerebral venous sinus thrombosis

Although initially described in the 19th century, cerebral venous sinus thrombosis (CVST) remains a diagnostic and therapeutic dilemma. It has an unpredictable course, and the propensity for hemorrhagic infarction produces significant consternation among clinicians when considering anticoagulation. It is the purpose of this review to analyze the evidence available on the management of CVST and to provide appropriate recommendations. A thorough literature search was conducted through MEDLINE and PubMed, with additional sources identified through cross-referencing. A classification and level of evidence assignment is provided for recommendations based on the American Heart Association methodologies for guideline composition. Of the publications identified, the majority were isolated case reports or small case series. Few prospective trials have been conducted. Existing data support the use of systemic anticoagulation as an initial therapy in all patients even in the presence of intracranial hemorrhage. Chemical and/or mechanical thrombectomy, in conjunction with systemic anticoagulation, is an alternative strategy in patients with progressive deterioration on heparin therapy or in those who are moribund on presentation. Mechanical thrombectomy is probably preferred in patients with preexisting intracranial hemorrhage. Effective treatments exist for the management of CVST, and overall outcomes are more favorable than those for arterial stroke. Further research is necessary to determine the role of individual therapies; however, the rarity of the condition poses a significant limitation.

Up to 151 days of continuous animal perfusion with trivial heparin infusion by the application of a long-term durable antithrombogenic coating to a combination of a seal-less centrifugal pump and a diffusion membrane oxygenator

We developed a new coating material (Toyobo-National Cardiovascular Center coating) for medical devices that delivers high antithrombogenicity and long-term durability. We applied this coating to an extracorporeal membrane oxygenation (ECMO) system, including the circuit tube, cannulae, a seal-less centrifugal pump, and a diffusion membrane oxygenator, to realize prolonged cardiopulmonary support with trivial anticoagulant infusion. The oxygenator consisted of a hollow-fiber membrane made of polymethylpentene, which allows the transfer of gas by diffusion through the membrane. The centrifugal pump was free of seals and had a pivot bearing. We performed a venoarterial bypass in a goat using this ECMO system, and the system was driven for 151 days with trivial anticoagulant infusion. Plasma leakage from the oxygenator did not occur and sufficient gas-exchange performance was well maintained. In the oxygenator, thrombus formation was present around the top and the distributor of the inlet portion and was very slight in the outlet portion. In the centrifugal blood pump, there was some wear in the female pivot region and quite small amounts of thrombus formation on the edge of the shroud; the pivot wear seemed to be the cause of the hemolysis observed after 20 weeks of perfusion and which resulted in the termination of the perfusion. However, no significant amounts of thrombus were observed in other parts of the system. This ECMO system showed potential for long-term cardiopulmonary support with minimal use of systemic anticoagulants.

Systemic Anticoagulant Prophylaxis for Central Catheter–Associated Venous Thrombosis in Cancer Patients

To review the literature regarding the incidence of thrombosis in cancer patients with central venous catheters (CVCs) and weigh the evidence supporting thromboprophylaxis in this patient population. Clinical literature was identified by searching MEDLINE (1966-February 2007) using the key search terms malignancy, cancer, catheters, prophylaxis, thrombosis, and central venous catheters. An evaluation of retrospective and prospective clinical trials that studied the use of systemic anticoagulants (eg, warfarin, heparin, and low-molecular-weight heparin [LMWH]) to prevent thrombosis with CVCs was performed. Different patient populations, including those manifesting with solid tumor or hematologic malignancy and those undergoing hematopoietic stem cell transplant, were evaluated for this review. Thrombosis associated with CVCs is a common complication in cancer patients. Most CVC thrombosis will occur within 30 days after placement, with a majority within 8 days. The incidence may depend on the type of CVC and location of the catheter tip. Despite recommendations against the use of systemic anticoagulation for prophylaxis against CVC thrombosis, a potential role continues to be explored in selected settings. Several variables are noted between published clinical trials, making any comparisons difficult to determine whether any benefit exists. Generally, the use of mini-dose warfarin, LMWH, or low-dose unfractionated heparin did not consistently reach significance in reporting a reduction in CVC thrombosis. Available data do not support the routine use of anticoagulants for thromboprophylaxis to prevent CVC-related thrombosis. However, several inconsistencies can be found in the studies done to date. More studies are needed to identify subsets of cancer patients who are at higher risk of developing CVC thrombosis and may benefit from prophylactic systemic anticoagulation.

At least thirty-four days of animal continuous perfusion by a newly developed extracorporeal membrane oxygenation system without systemic anticoagulants.

We developed an extracorporeal membrane oxygenation (ECMO) system with high antithrombogenicity and durability characteristics for prolonged continuous cardiopulmonary support. The oxygenator consists of a special hollow-fiber-type polyolefin gas-exchange membrane, which has an ultrathin dense layer in contact with the blood, in order to prevent plasma leakage during protracted use (Platinum Cube NCVC). The centrifugal pump (RotaFlow) is free of seals. The entire blood-contacting surface of the system is coated with a newly developed heparin material (Toyobo-NCVC coating). We performed a venoarterial bypass in a goat, and the ECMO system was driven for 34 days without systemic anticoagulants. Plasma leakage from the oxygenator did not occur, and sufficient gas exchange performance was maintained. Thrombus formation was hardly observed in the ECMO system except in the casing margins of the oxygenator. This ECMO system showed potential for long-term cardiopulmonary support with minimal or no use of systemic anticoagulants.

Intravascular ultrasound-guided optimized stent deployment. Immediate and 6 months clinical and angiographic results from the Multicenter Ultrasound Stenting in Coronaries Study (MUSIC Study)

A study was set up to validate the safety and feasibility of intravascular ultrasound-guided stenting without subsequent anticoagulation, and its impact on the 6 months restenosis rate. The study was designed to be multicentred, prospective, and observational. One hundred and sixty-one patients with stable angina and a de novo coronary artery lesion were enrolled. In four patients, the implantation of a Palmaz-Schatz (with spiral bridge) stent had failed. One of these four patients died 3 days following bypass surgery. In two other patients, intravascular ultrasound assessment was not performed. One hundred and twenty-five of the remaining 155 patients (81%) were treated with aspirin (100 mg x day(-1)), because all three criteria for optimized stent expansion were met. Twenty-two of the remaining 38 patients (25%), in whom at least one criterion was not met were treated with aspirin and acenocoumarol (3 months, INR 2.5-3.5), while 16 patients only received aspirin. Stent thrombosis was documented in two patients (1.3%) for which repeat angioplasty was performed. During the hospital stay, there were no deaths or Q-wave myocardial infarctions. Five patients (3.2%) sustained a non-Q-wave myocardial infarction. During the follow-up period (198+/-38 days, complete for all patients, except one), one patient (0.6%) sustained a Q-wave myocardial infarction, one (0.6%) underwent bypass surgery, and repeat angioplasty was performed in nine patients (5.7%). In two of the nine patients, repeat angioplasty involved another lesion. Therefore, the target lesion revascularization rate during follow-up was 4.5% (seven patients). At quantitative coronary angiography, the minimal lumen diameter (mean+/-SD) increased from 1.12+/-0.34 mm before to 2.89+/-0.35 mm after stenting. Repeat angiography at 6 months was performed in 144 patients (92%). The minimal lumen diameter at follow-up was 2.12+/-0.67 mm. Restenosis (diameter stenosis of 50% or more) was documented in 12 patients or 8.3%. When the two patients with documented stent thrombosis are included, the restenosis rate amounts to 97%. These data confirm that, in selected patients, stents can safely be implanted without the use of systemic anticoagulation, provided optimal stent expansion is achieved. The exact role of intravascular ultrasound in the achievement of these results needs to be established by appropriately designed studies. In the meantime, intravascular ultrasound coupled with the Palmaz-Schatz stent incorporating a spiral bridge, may have contributed considerably to the immediate angiographic outcome, which in turn may explain the favourable clinical and angiographic outcome at 6 months.

Lesiones vasculares yatrogénicas tras cateterismo cardíaco

The increase in vascular complications after cardiac catheterizations is rising due to the increase in the total number of these procedures. The purpose of this report is to determine the incidence of this complication and to identify the variables which are related to the presence of vascular complications which required surgical repair. Retrospective review of the 3,723 cardiac catheterizations made by the interventional cardiology department during a period between June 1992 to August 1996. Thirty two vascular complications were detected (0.9%), which required surgical reparation. There was no statistical difference in age, sex, presence of vascular risk factors, cardiac indication for catheterization and vascular approach between those patients who had a vascular complication and those who did not. The presence of obesity [RR: 2.5, IC 95% (1.2-5)], use of catheter sheath, superior or equal to 8F [RR: 0.3, IC 95% (0.14-0.62)] and use of systemic anticoagulation [RR: 4.8, IC 95% (2.1-10.8)], increase the risk of vascular complications. Two patients died (6.2%) due to cardiac complications and there were minor complications in 23% after surgical repair. Vascular complications after cardiac catheterization continue to be a significant problem. There are several variables which influence the presentation of vascular complications. Continued surveillance of cardiac catheterization complications is necessary to minimize problems and improve results.

Periadventitial delivery of heparin in the prevention of microvenous thrombosis

Purpose: In spite of advances in technique and instrumentation, microvascular free tissue transfer remains associated with a persistent risk of flap failure. The use of systemic anticoagulants to overcome the formation of vasoocclusive thrombi at reactive anastomotic sites is associated with a high rate of flap hematoma and is ill advised in the operative setting. The purpose of this study was to investigate the use of a biodegradable, nontoxic polymer gel (polyvinyl alcohol, PVA) to effect a sustained localized release of perivascular heparin around thrombogenic venous anastomoses. Materials and Methods: A modified adventitial inclusion model was created in the femoral vein of 64 adult female Sprague-Dawley rats. Animals were divided into four experimental groups: 1) no treatment (controls), 2) periadventitial PVA gel contained in a vicryl chamber, 3) periadventitial PVA gel mixed with heparin, and 4) systemic heparin (intravenous pump). Patency rates in the femoral vein were checked at 10 minutes, 1 hour, 1 day, and 4 days after surgery. Systemic coagulation parameters and histology (scanning electron microscopy, SEM) were assessed in representative animals from all groups. Results: Patency rates for experimental groups showed a significant improvement in animals treated with PVA/heparin and systemic heparin over controls. Wound hematomas occurred in 7 of 16 animals in group 3, and in 4 of 16 animals in group 4. Activated partial thromboplastin times were elevated in group 4 only (>150 seconds). Conclusions: Continuous release of periadventitial heparin using a polymeric delivery system may represent an efficient means of attenuating the reactivity of microvenous anastomoses without affecting systemic coagulation parameters. In this model, however, its use was associated with a high rate of local wound hematoma.

Femoral veno-arterial extracorporcal life support with minimal or no heparin

Recent technological advances in cardiopulmonary bypass circuits achieving surface bonding with heparin have permitted prolonged extracorporeal life support (ECLS) in experimental studies without the use of systemic anticoagulation. Excessive bleeding and the need for massive transfusions after extended ECLS with systemic heparinization have often led to the development of sepsis and multisystem organ failure. The Carmeda bioactive surface circuit, along with a Bio-Medicus centrifugal pump (Bio-Pump) and the femoral veno-arterial route, were used successfully in 3 patients requiring ECLS between April 1992 and December 1992. In 2 patients the need for ECLS was acute allograft dysfunction after orthotopic cardiac transplantation with no evidence of cellular rejection. Both patients were receiving multiple inotropes and intraaortic balloon counterpulsation; their condition continued to deteriorate rapidly before the initiation of ECLS. The third patient failed to be weaned from cardiopulmonary bypass after myocardial rcvascularization for ischemic cardiomyopathy. Time on ECLS ranged from 57 to 128 hours. No systemic anticoagulation was used. One patient received no heparin, and the other 2 patients received intermittent heparin infusion to maintain an average activated clotting time of 195 and 214 seconds. Multisystem organ dysfunction present before initiation of ECLS was rapidly reversed, and all patients were weaned successfully without any immediate major complications. The ability to conduct prolonged ECLS without systemic anticoagulation and without repeat sternotomy opens new avenues for the use of this procedure in profound heart failure.

Maintenance of patency after vascular trauma by topical irrigation with a peptide homologous to the carboxy-terminus of the fibrinogen gamma chain

Synthetic peptides with amino acid sequences homologous to the carboxy-terminal sequence of the gamma chain of human fibrinogen were evaluated for their capacity to inhibit thrombus development. A 21-residue peptide effectively inhibited surface-mediated fibrin clot propagation in vitro. Since this effect was localized to the surface, we proceeded with in vivo evaluation, using site-specific topical application only. In a rat model of arterial trauma and microvascular repair, topical application of the 21-residue peptide significantly reduced the rate of thrombosis to 17%, as compared with a control rate of 83%; in comparison, a 12-residue homologue reduced the thrombosis rate only modestly to 61%, which was not significant compared with the control rate. These results indicate the feasibility of antithrombotic therapy with topically applied agents, an approach that may obviate the use of systemic anticoagulation in extremity-replantation surgery.

Venous Bypass in Clinical Liver Transplantation

A venous bypass technique (BP) that does not require the use of systemic anticoagulation is used routinely at our institution in all adult patients during the anhepatic phase of liver transplantation (LT). Complete cardiopulmonary profiles were obtained in a subset of 28 consecutive cases. During the anhepatic phase while on bypass, mean arterial pressure, central venous pressure, and pulmonary arterial wedge pressure were maintained at prehepatectomy levels. Oxygen consumption fell secondary to a decrease in temperature and the removal of the liver. Consequently, cardiac index fell without an increase in arterial-venous O2 content difference, reflecting adequate tissue oxygenation. Compared with 63 patients in a previous series given LT without bypass (NBP), the 57 total BP patients experienced better postoperative renal function (p less than 0.001), required less blood use during surgery (p less than 0.01), and had better survival 30 days after LT. The equivalency of 90-day survival in these groups results from the lack of effect of BP on the long-term survival of patients considered at high risk for metabolic reasons. BP patients at high risk for technical considerations, however, survived LT whereas NBP patients did not. BP offers other advantages important in establishing LT as a service-oriented procedure.

Percutaneous transfemoral coronary arteriography without systemic anticoagulation--a review of 648 consecutive procedures.

Experience with 648 consecutive percutaneous transfemoral coronary arteriograms and left ventriculograms performed in a teaching laboratory without the use of systemic anticoagulation during the procedure was reviewed. Only 1 death was felt to be related to a procedure, and this occurred 3 weeks after a myocardial infarction. There were 10 myocardial infarctions or emboli, 8 cerebral vascular accidents, and 7 femoral artery complications. Only 1 patient experienced a residual neurologic change following a procedure-related cerebral vascular accident, and this was a mild visual field defect. Clotting of the catheter without sequelae but necessitating procedural changes occurred in 10 instances. The transient nature of the neurologic deficits and the low mortality suggest that the emboli which occurred in these patients were small, possibly platelet-fibrin accumulations. It is postulated that with the use of careful technic larger emboli capable of producing myocardial infarction with shock or disabling cerebral vascular accidents can be prevented, even in a training situation. However, smaller embolic phenomena probably cannot be completely avoided by the use of careful technic, and it is for prevention of small emboli that systemic anticoagulation with heparin may be of value.