Continuous Intravenous Heparin Research Articles

Anesthetic management in pregnant women with Fontan circulation: a case series.

Given the advances in medicine, women with Fontan circulation are now reaching childbearing age. However, data on the mode of delivery and anesthetic management of these patients are limited. We report the cases of five pregnant women with Fontan circulation. The mean age at delivery was 28 ± 3years, and the mean gestational period was 34weeks and 3days. Anticoagulation therapy was switched from warfarin and aspirin to continuous intravenous heparin. The modes of delivery were scheduled cesarean section (C/S) in one, emergency C/S in three, and vaginal delivery with epidural labor analgesia in one patient. Three patients underwent C/S under regional anesthesia; one received general anesthesia. The perinatal complications were heart failure, worsening valve regurgitation, and postoperative hematoma in three, four, and two patients, respectively. For C/S in women with Fontan circulation, regional anesthesia should be considered. Epidural labor analgesia can help prevent the decrease in pulmonary blood flow due to straining. We initiated labor analgesia or C/S with regional anesthesia at the appropriate time in four patients.

Antithrombin Levels and Heparin Responsiveness during Venoarterial Extracorporeal Membrane Oxygenation: A Prospective Single-center Cohort Study.

Unfractionated heparin, administered during venoarterial extracorporeal membrane oxygenation to prevent thromboembolic events, largely depends on plasma antithrombin for its antithrombotic effects. Decreased heparin responsiveness seems frequent on extracorporeal membrane oxygenation; however, its association with acquired antithrombin deficiency is poorly understood. The objective of this study was to describe longitudinal changes in plasma antithrombin levels during extracorporeal membrane oxygenation support and evaluate the association between antithrombin levels and heparin responsiveness. The hypothesis was that extracorporeal membrane oxygenation support would be associated with acquired antithrombin deficiency and related decreased heparin responsiveness. Adults receiving venoarterial extracorporeal membrane oxygenation were prospectively included. All patients received continuous intravenous unfractionated heparin using a standardized protocol (target anti-Xa 0.3 to 0.5 IU/ml). For each patient, arterial blood was withdrawn into citrate-containing tubes at 11 time points (from hour 0 up to day 7). Anti-Xa (without dextran or antithrombin added) and antithrombin levels were measured. The primary outcome was the antithrombin plasma level. In the absence of consensus, antithrombin deficiency was defined as a time-weighted average of antithrombin less than or equal to 70%. Data regarding clinical management and heparin dosage were collected. Fifty patients, including 42% postcardiotomy, were included between April 2020 and May 2021, with a total of 447 samples. Median extracorporeal membrane oxygenation duration was 7 (interquartile range, 4 to 12) days. Median antithrombin level was 48% (37 to 60%) at baseline. Antithrombin levels significantly increased throughout the follow-up. Time-weighted average of antithrombin levels was 63% (57 to 73%) and was less than or equal to 70% in 32 (64%) of patients. Overall, 45 (90%) patients had at least one antithrombin value less than 70%, and 35 (70%) had at least one antithrombin value less than 50%. Antithrombin levels were not significantly associated with heparin responsiveness evaluated by anti-Xa assay or heparin dosage. Venoarterial extracorporeal membrane oxygenation support was associated with a moderate acquired antithrombin deficiency, mainly during the first 72 h, that did not correlate with heparin responsiveness.

Intravenous enoxaparin as alternative ECMO anticoagulation over a period of 94 days: a case report

BackgroundUnfractionated heparin is used worldwide as a standard anticoagulation therapy for extracorporeal membrane oxygenation (ECMO) machines. However, its use brings about significant bleeding and thrombotic complications for critically ill patients. This case report shows that low molecular weight heparin together with ECMO-produced primary haemostasis pathology can be used as an alternative way of ECMO anticoagulation.Case presentationThis paper presents the case of a patient with respiratory failure who subsequently suffered from cardiac failure and spent 94 days on combined V-V and V-A ECMO devices (two ECMO devices running simultaneously on one patient) with intravenous enoxaparin used instead of unfractionated heparin anticoagulation. No life-threatening bleeding/thrombotic events happened during this period, nor did any technical problems with ECMO occur.ConclusionsIn this case report, continuous intravenous low molecular weight heparin anticoagulation was used as a safe alternative to ECMO anticoagulation.

KOUNIS SYNDROME, THE ALLERGIC HEART ATTACK

<h3>Introduction</h3> Seldom do allergic reactions progress to involve the heart. Kounis Syndrome is the occurrence of acute coronary syndrome associated with conditions of mast cell activation such as allergy hypersensitivities (1). Here, we describe a case in which an allergic reaction to injected Lidocaine and Kenalog leads to myocardial infarction. <h3>Case Description</h3> A 67-year-old female with cardiac risk factors and osteoarthritis underwent injection of her right ankle with Lidocaine and Kenalog. She developed diffuse erythematous rash with symptoms of lightheadedness, altered mentation, and chest discomfort. Upon admission, she received epinephrine. Electrocardiogram (EKG) demonstrated ST-segment elevation in inferior leads II, III, and aVF. Labs revealed serum tryptase level of 74.8 ug/L. The patient received intravenous (IV) Norepinephrine, IV diphenhydramine, IV Famotidine, IV methylprednisolone, Aspirin, and continuous IV heparin for emergent coronary angiography. The distal right coronary artery revealed occlusive thrombus burden, causing 95% stenosis. Percutaneous coronary intervention was performed with drug-eluting stent placement. Her symptoms resolved, and she was referred to an outpatient allergist. <h3>Discussion</h3> This case illustrates the type II variant of Kounis Syndrome in which inflammatory mediators from an allergic reaction induce atherosclerotic plaque destabilization and rupture in underlying coronary artery disease (CAD). Cardiovascular manifestations associated with allergic conditions are more common than initially perceived, suggesting a causal relationship between allergies and heart disease. This remains underdiagnosed by clinicians in practice (1,2). Biomarkers in allergies, such as serum tryptase, may provide a potential marker of CAD. Novel medications that stabilize mast cells and reduce inflammation known to control allergies may ultimately reduce cardiovascular events (4).

Monitoring of Unfractionated Heparin Therapy in the Intensive Care Unit Using a Point-of-Care aPTT: A Comparative, Longitudinal Observational Study with Laboratory-Based aPTT and Anti-Xa Activity Measurement.

Continuous intravenous unfractionated heparin (UFH) is administered routinely in the intensive care unit (ICU) for the anticoagulation of patients, and monitoring is performed by the activated partial thromboplastin time (APTT) or anti-Xa activity. However, these strategies are associated with potentially large time intervals before dose adjustments, which could be detrimental to the patient. The aim of the study was to compare a point-of-care (POCT) version of the APTT to (i) laboratory-based APTT and (ii) measurements of anti-Xa activity in terms of correlation, agreement and turnaround time (TAT). Thirty-five ICU patients requiring UFH therapy were prospectively included and followed longitudinally for a maximum duration of 15 days. UFH was administered according to a local adaptation of Raschke and Amanzadeh’s aPTT nomograms. Simultaneous measurements of POCT-APTT (CoaguCheck® aPTT Test, Roche Diagnostics) on a drop of fresh whole blood, laboratory-based APTT (C.K. Prest®, Stago) and anti-Xa activity (STA®Liquid anti-Xa, Stago) were systematically performed two to six times a day. Antithrombin, C-reactive protein, fibrinogen, factor VIII and lupus anticoagulant were measured. The time tracking of sampling and analysis was recorded. The overall correlation between POCT-APTT and laboratory APTT (n = 795 pairs) was strongly positive (rs = 0.77, p < 0.0001), and between POCT-APTT and anti-Xa activity (n = 729 pairs) was weakly positive (rs = 0.46, p < 0.0001). Inter-method agreement (Cohen’s kappa (k)) between POCT and laboratory APTT was 0.27, and between POCT and anti-Xa activity was 0.30. The median TATs from sample collection to the lab delivery of results for lab-APTT and anti-Xa were 50.9 min (interquartile range (IQR), 38.4–69.1) and 66.3 min (IQR, 49.0–91.8), respectively, while the POCT delivered results in less than 5 min (p < 0.0001). Although the use of the POCT-APTT device significantly reduced the time to results, the results obtained were poorly consistent with those obtained by lab-APTT or anti-Xa activity, and therefore it should not be used with the nomograms developed for lab-APTT.

Leriche syndrome diagnosed due to polytrauma: a case report

BackgroundLeriche syndrome is caused by atherosclerosis and is often characterized by symptoms such as intermittent claudication and numbness and coldness of the lower limbs. Its exact prevalence and incidence are unknown because it is a rare disease. We report a case of Leriche syndrome diagnosed incidentally on trauma pan-scan computed tomography (CT).Case presentationA 61-year-old Asian male was driving a passenger car and had a head-on collision with a dump truck that required an emergency call. The patient was transported to our hospital in a doctor’s helicopter. Physical examination revealed the following vital signs: respiratory rate, 23 breaths per min; SpO2, 98% under a 10-L administration mask; pulse rate, 133 beats per min; blood pressure, 142/128 mmHg; Focused Assessment with Sonography for Trauma, positive; Glasgow Coma Scale assessment, E3V5M6; and body temperature, 35.9 °C.Trauma pan-scan CT showed bilateral mandibular fractures, bilateral multiple rib fractures, bilateral pneumothorax, sternal fractures, hematoma around thoracic spine, small bowel perforation, mesenteric injury, right clavicle fracture, right ankle debridement injury, and thrombotic occlusion from just above the abdominal aortic bifurcation to the bilateral common iliac arteries. Although thrombotic occlusion needed to be differentiated from traumatic aortic injury, the presence of collateral blood vessels led to the diagnosis of Leriche syndrome, and conservative treatment was performed.Damage control surgery was required for the small bowel injuries. From the second day of admission, the patient was treated with continuous intravenous heparin and prostaglandin preparations. However, impaired blood flow and reperfusion injury in the right lower extremity progressed. On the fifth day of admission, right thigh amputation was performed. The patient required renal replacement therapy for 2 weeks starting from the third day of admission.ConclusionsIn this case, conservative therapy was initially chosen for Leriche syndrome. However, the complex factors in the acute phase of trauma led to development of hemorrhagic necrosis, requiring amputation of the lower extremity. Our findings indicate the need to carefully consider the unique factors affecting Leriche syndrome patients when considering treatment indications and choices for trauma.

Pheochromocytoma Rupture Associated With Systemic Anticoagulation: A Case Report

Background: Pheochromocytoma rupture is a rare endocrine emergency. There have been approximately 85 documented cases, and the mortality rate for patients who require emergent surgery is as high as 34% (1). Clinical Case: A 30-year-old man with no past medical history presented to the Emergency Department with abdominal pain and vomiting. He was hypertensive, tachycardic, and hypoxic. CT Chest Angiogram revealed bilateral pulmonary emboli and a 6.5 x 5.5 x 6.4 cm left heterogenous adrenal mass. His plasma free metanephrines were elevated to 31,173 pg/mL (n<62 pg/mL) with normetanephrines >50,000 pg/mL (n<145 pg/mL). His pulmonary emboli was treated with continuous intravenous heparin, and he was also treated with intravenous fluids and phentolamine due to concern for pheochromocytoma. Within hours, he became hypotensive, and his hemoglobin downtrended from 16.4 g/L to 7.3 g/L (n 14–18 g/L). Repeat CT showed that the adrenal mass had ruptured, enlarging to 15.4 x 9.7 x 10.0 cm. He was taken for an emergent laparotomy with piecemeal resection of the mass; surgical pathology confirmed a pheochromocytoma. Fortunately, the patient recovered well after surgery. After 6 months, his plasma free metanephrines normalized to 15 pg/mL with normetanephrines of 80 pg/mL. His DOTATATE scan was negative for malignancy and his genetic testing was negative. Conclusion: The patient’s systemic anticoagulation and critical illness likely increased his risk for pheochromocytoma rupture. Standard preoperative pheochromocytoma management, to include aggressive fluid resuscitation and alpha blockade, is important in reducing risk of morbidity and mortality. Biochemical follow up is required, as there is a 16% risk of recurrence. Reference: (1) Kobayashi T, Iwai A, Takahashi R, Ide Y, Nishizawa K, Mitsumori K. Spontaneous rupture of adrenal pheochromocytoma: Review and analysis of prognostic factors. Journal of Surgical Oncology. 2005;90(1).

Midline catheter placement in an obese patient with difficult venous access

Rationale: Obesity is a risk factor for difficult venous access, catheter-related blood stream infections and thrombosis. All venous access devices have some disadvantages in obese patients. The Michigan Appropriateness Guide for Intravenous Catheters recommends choosing the optimal venous access device for each patient individually. Recently, the midline catheter has been considered an attractive alternative to the peripherally inserted central catheter. The appropriateness of midline catheters as venous access devices in obese patients needs further evaluation. Patient concerns: A 76-year-old woman was diagnosed with right breast cancer and scheduled for total mastectomy. The patient was obese (body mass index 37) and had difficult venous access. Diagnosis: After multiple failures of peripheral venous access, cellulitis developed in the left forearm. Interventions: Under ultrasound guidance, a relatively large (7 mm in diameter) and deep (3 cm in depth) basilic vein was found in the left arm and a midline catheter was smoothly placed into the vein (catheter vein ratio 6.3%). Surgery was performed with no adverse events. After surgery the patient was medicated with continuous intravenous administration heparin for thromboprophylaxis due to her having paroxysmal atrial fibrillation. Outcomes: The midline catheter was indwelled for 10 days. The patient was discharged without complications. Lessons: There is no single best choice for venous access in obese patients. The midline catheter is not recommended for venous access in all obese patients. However, some disadvantages may be overcome by careful placement and a strategy to prevent catheter-related thrombosis.

91-Year-Old Man With Upper Extremity Ecchymoses

91-Year-Old Man With Upper Extremity Ecchymoses

Heparin-Induced Thrombocytopenia in Healthy Individuals with Continuous Heparin Infusion.

The risk for developing heparin-induced thrombocytopenia in healthy individuals is thought to be low, but monitoring recommendations remain controversial. Therefore, a retrospective cohort study was conducted to identify the incidence of thrombocytopenic events in a healthy research population exposed and re-exposed to continuous intravenous (IV) unfractionated heparin. The Division of Sleep Medicine and the Centre for Clinical Investigations at Brigham and Women's Hospital, Boston, Massachusetts, United States, instituted a standardized platelet monitoring procedure for all research protocols that involved heparin to detect platelet count decreases. Protocol-related frequent blood sampling required use of continuous IV unfractionated heparin infusion (5,000 unit/L in 0.45% saline at 40 mL/h) to maintain line patency over extended periods of IV access. From the years 2009 to 2012, a total of 273 healthy volunteers enrolled in Sleep Medicine research protocols met study criteria as having been exposed and/or re-exposed to continuously infused intravenous heparin for at least 4 hours. The mean continuous heparin exposure time was 88 ± 82 SD hours with a total of 397 heparin exposure and re-exposure events. Platelet count measurements were obtained on 629 occasions, representing a range from 2 to 9 draws per participant. No platelet count decrease of more than 50% was detected. There were no detected adverse bleeding or thrombotic events. In this retrospective study of healthy volunteers involved in a rigorously applied inpatient platelet monitoring protocol, heparin exposure and re-exposure did not lower platelet concentration and, therefore, does not appear to be associated with increased risk of HIT in this population.

Recurrent cerebral attack caused by thrombosis in the pulmonary vein stump in a patient with left upper lobectomy on anticoagulant therapy: case report and literature review

BackgroundThrombus formation in the pulmonary vein stump after pulmonary resection has recently been identified as a cause of systemic thrombosis including brain infarction. However, there is limited research focusing on the clinical course of pulmonary vein stump thrombus, and optimal treatment and prevention strategies of this important complication have not been established.Case presentationA 77-year-old woman was diagnosed with lung cancer of the left upper lobe, cT4N2M0, cStage IIIB. As the tumor was considered to be completely resectable, the patient underwent a left upper lobectomy with angioplasty of the left pulmonary artery. The final pathological stage was pT4N2M0, pStage IIIB. The patient developed paralysis of the right upper limb and dysarthria on the 8th postoperative day. Diffusion-weighted magnetic resonance imaging (MRI) of the brain showed multiple high-intensity signals in the area of the left middle cerebral artery, which were not detected on preoperative MRI. She was diagnosed with a cerebral infarction and started on acute-phase treatment including anticoagulation with continuous intravenous heparin infusion. The neurological symptoms improved the following day. Contrast-enhanced chest CT scan revealed thrombus in the left superior pulmonary vein stump measuring 10 mm in diameter. She had no comorbidity related to the cerebral attack. After the treatment was initiated, her symptoms became stable. However, symptoms of altered consciousness, dysarthria, and hemiparesis re-occurred on the 19th postoperative day and improved within an hour. The thrombus in the left superior pulmonary vein stump disappeared on follow-up contrast-enhanced chest CT performed the same day.ConclusionsThis is the first report of recurrent brain attack caused by thrombosis in the pulmonary vein stump in a patient receiving anticoagulant therapy. The present case suggests the possibility of thrombus mobilization causing recurrent systemic thrombosis, and this important complication needs to be considered in future clinical practice.

Novel Treatments in Neuroprotection for Aneurysmal Subarachnoid Hemorrhage.

New neuroprotective treatments aimed at preventing or minimizing "delayed brain injury" are attractive areas of investigation and hold the potential to have substantial beneficial effects on aneurysmal subarachnoid hemorrhage (aSAH) survivors. The underlying mechanisms for this "delayed brain injury" are multi-factorial and not fully understood. The most ideal treatment strategies would have the potential for a pleotropic effect positively modulating multiple implicated pathophysiological mechanisms at once. My personal management (RFJ) of patients with aneurysmal subarachnoid hemorrhage closely follows those treatment recommendations contained in modern published guidelines. However, over the last 5years, I have also utilized a novel treatment strategy, originally developed at the University of Maryland, which consists of a 14-day continuous low-dose intravenous heparin infusion (LDIVH) beginning 12h after securing the ruptured aneurysm. In addition to its well-known anti-coagulant properties, unfractionated heparin has potent anti-inflammatory effects and through multiple mechanisms may favorably modulate the neurotoxic and neuroinflammatory processes prominent in aneurysmal subarachnoid hemorrhage. In my personal series of patients treated with LDIVH, I have found significant preservation of neurocognitive function as measured by the Montreal Cognitive Assessment (MoCA) compared to a control cohort of my patients treated without LDIVH (RFJ unpublished data presented at the 2015 AHA/ASA International Stroke Conference symposium on neuroinflammation in aSAH and in abstract format at the 2015 AANS/CNS Joint Cerebrovascular Section Annual Meeting). It is important for academic physicians involved in the management of these complex patients to continue to explore new treatment options that may be protective against the potentially devastating "delayed brain injury" following cerebral aneurysm rupture. Several of the treatment options included in this review show promise and could be carefully adopted as the level of evidence for each improves. Other proposed neuroprotective treatments like statins and magnesium sulfate were previously thought to be very promising and to varying degrees were adopted at numerous institutions based on somewhat limited human evidence. Recent clinical trials and meta-analysis have shown no benefit for these treatments, and I currently no longer utilize either treatment as prophylaxis in my practice.

Use of systemic low-dose unfractionated heparin in microvascular head and neck reconstruction: Influence in free-flap outcomes

Background: Intravenous heparin administration is used to prevent thrombosis in free-flap transfer. However, it is unknown whether the use of heparin affects free-flap survival. The purpose of this study is to investigate the effect of heparin in free flap transfer. Methods: Two hundred and six patients who received ablative surgery for head and neck cancer were classified into three groups. Group A received ablative surgery, neck dissection, and free-flap reconstruction, and postoperatively they were administered continuous intravenous unfractionated heparin (5000–10 000 units/day) until postoperative day 7 (POD7); group B received the same procedures as group A but without heparin; group C received only ablative surgery and neck dissection without heparin. As indicators of coagulation time, the prothrombin time-international normalised ratio (PT-INR) and the activated partial thromboplastin time (APTT) were measured, before surgery and on POD1, 3, and 7. Flap failure, bleeding, haematoma formation, re-exploration, and thromboembolic events were recorded. Results: The PT-INR and APTT were 1.3–1.5-times longer in group A (p < 0.01), and 1.3-times longer (p < 0.01) in group B. The PT-INR and APTT were higher in groups A and B than C (p < 0.01). The free-flap success rate was not affected. Only the incidence of haematoma was increased in group A (p = 0.04). Conclusion: Heparin increased the haematoma formation, but did not change the incidence of free-flap failure. Thus, the intravenous low-dose heparin use does not affect microvascular flap survival.

Improvements for Continuous Intravenous Heparin Management Practice through Application of HOAP (Heparin Order &amp; Administration Program)

Improvements for Continuous Intravenous Heparin Management Practice through Application of HOAP (Heparin Order &amp; Administration Program)

A Marantic Endocarditis Complicating a Metastatic Gastric Adenocarcinoma Initially Resistant to Low-molecular Weight Heparin: A Case Report

Background: Marantic endocarditis is a rare paraneoplastic syndrome which results from an hypercoagulate state. It can be associated with several tumors, particularly gastric cancer, and histology of adenocarcinoma. Mucines secreted by adenocarcinoma contribute to the activation of the coagulation pathway. Case presentation: We present the case of a patient with a marantic endocarditis complicating a metastatic gastric adenocarcinoma. He was hospitalised for a thoracic pain. At the physical examination, we found swelling, redness, and warmth of the right lower limb, suspected for a deep vein thrombosis that was confirmed at the echo doppler ultrasound. CT scan documented a severe bilateral pulmonary embolism, a splenic infarction, and multiple liver metastases. Laboratory tests were normal. Despite a Low-Molecular Weight Heparin (LMWH) treatment, the patient presented a cerebral stroke, confirmed at the MRI. Trans-thoracic echocardiography found a small vegetation of the mobile end of the mitral valve with a normal left ventricular contractile function. LMWH was switched by continuous intravenous Unfractionated Heparin (UFH). PET scan showed multiple liver metastases and a pathological gastric hypermetabolism. Liver biopsy confirmed a metastasis of a HER-2 negative gastric adenocarcinoma. Because of the stop of heparin treatment during this procedure, the patient presented a new brain stroke. A systemic palliative chemotherapy was started by FOLFOX-4 regimen and it is now ongoing. Conclusion: The particularity of this case relies on the impossibility to initially switch UFH by another anticoagulant treatment. Chemotherapy represents the only possibility to decrease mucine production and thrombi formation.

Pulmonary thromboembolism in lung surgery: use of unfractionated heparin

While thoracic surgeons occasionally encounter pulmonary thromboembolism, the use of unfractionated heparin may cause adverse effects. We assessed a series of 323 consecutive pulmonary operations performed during 4 years from 2008 to 2011. All patients were given elastic stockings and intermittent pneumatic compression. During the first 2 years (2008-2009), none of the 169 patients received unfractionated heparin. In the second 2-year period (2010-2011), 135/154 patients received subcutaneous unfractionated heparin, either 5000 units (n = 37) or 2500 units (n = 93) twice daily for 3 days, or continuous intravenous unfractionated heparin (n = 5). The epidural catheters were withdrawn 6 h or more after unfractionated heparin use. Among patients without postoperative unfractionated heparin, 8 (42.1%) had a bleeding risk and 5 (26.3%) had limited operative time. One (0.6%) patient developed pulmonary thromboembolism during 2008-2009, but none had this complication during 2010-2011. The adverse outcome of intrathoracic bleeding occurred in one (2.7%) of the patients given 5000 units of unfractionated heparin, but no epidural hematomas occurred in these patients. Patients undergoing thoracic surgery at low risk of bleeding may receive unfractionated heparin to prevent pulmonary thromboembolism while avoiding epidural complications.

Transient cortical blindness after spinal surgery as initial presenting sign of hereditary thrombophilia

Sir, Cortical blindness is a rare complication of spine surgery,[1] and is followed by a period of recovery due to resolution of inflammation and edema around the lesion and to the re-activation of partially damaged perilesional tissue.[2,3] Bilateral occipital abnormalities caused by hypotension, ischemia and infarction are associated with poor prognosis. Herein, we report complete recovery of a case with cortical blindness, despite having an ischemic infarct. A 33-year-old female patient who was otherwise healthy underwent uneventful simple discectomy operation. In the immediate postoperative period, she had a syncopal attack and was hypotensive for 5-6 min. After emergency aid, she regained consciousness and complained that she could not see. On neurologic examination, both pupils were isocoric and equally reactive to light and accomodation. There was perception of hand motion. Fundoscopic examination was normal. Cranial magnetic resonance imaging (MRI) revealed hypodense areas involving the occipital lobes bilaterally [Figs. ​[Figs.1,1, ​,2a2a and ​andb].b]. D-dimer test was positive. Deep vein thrombosis in the right popliteal vein was detected ultrasonographically. In spiral computerized tomography (CT) of the thorax scan, there were patchy consolidation areas. Her electrocardiogram showed sinusal tachycardia with an incomplete right bundle-branch block. There were moderate tricuspid insufficiency and mild pulmonary hypertension echocardiographically. She was diagnosed to have massive pulmonary embolism and cortical blindness, and was admitted to the intensive care unit. Treatment was started with continuous intravenous heparin infusion. The patient's vision gradually began to improve within 24 h. Radiological cure with normal thoracal CT was seen on the seventh day. Her vision restored to its preoperative level on the 25th day. After 2 months, there were relative deficits in the right lower temporal quadrant and in the left lower hemifield in visual field examination. Contrast sensitivity evaluation showed losses at high frequencies in the right eye and at all spatial frequencies in the left eye. Color vision assessment revealed low pattern discrimination. For excluding any prothrombotic state, a haemotologic evaluation revealed heterozigousity for factor V Leiden R506Q, protrombin G20210A and MTHFRC677T. Anticoagulant therapy was initiated. In the 3rd year follow-up of the patient, near-complete regression of the infarct area was found in the MRI and improvement of visual field defects was observed [Fig. 3]. Color vision was near-perfect in both eyes. Contrast sensitivity was slightly improved. Figure 1 Diffusion-weighted image showing diffusion restriction compatible with the acute infarct involving the striate and extrastriate cortex (arrows) Figure 2 (a and b) Axial T2-weighted images showing hyperintense areas compatible with the acute infarct involving the striate and extrastriate cortex (arrows) Figure 3 Axial T2-weighted control image showing near-complete regression. There is an encephalomalasic area in the anterior part of the right occipital lobe Visual impairment in cortical blindness is highly variable, and deficits between the hemifields may be different.[4] In our patient, the infarct area was mainly in the cuneus, and corresponding visual field defects were in the lower hemifields. Besides, infarct area comprised both striate and extra-striate visual cortex initially and corresponding abnormalities in color vision and contrast sensitivity recovered with regression of the infarct area. Occipital lobe infarcts were reported to be frequently associated with a prothrombotic state, and were seen more frequently in younger patients and in patients of the female sex.[5] In young patients with cortical blindness, screening for thrombophilia should be made. Because visual loss may be reversible with initiation of immediate anticoagulation therapy, awareness, evaluation and prompt management of this rare complication is critical.

Initial Experience with a Juvenile Sheep Model for Evaluation of the Pediatric Intracorporeal Ventricular Assist Services

There is a scarcity of source material available in animal models appropriate to test pediatric-size blood pump design for assisting the left ventricle. A juvenile ovine animal model was developed to evaluate two pediatric ventricular assist devices (VADs). The child-size Jarvik 2000 and CircuLite VADs were tested with this model. The 33 in vivo experiments were retrospectively studied to evaluate the reliability of the animal model. Dorset hybrid juvenile sheep (20~36 kg) were used to evaluate the small pediatric VADs. Under general anesthesia, a left lateral thoracotomy was performed through the fifth intercostal space. The devices were implanted between the left ventricle apex and the descending aorta without cardiopulmonary bypass. Heparin was infused continuously for anticoagulation therapy. Support duration averaged 26.7 ± 19.6 days. Completion of 75.7% (25/33) experiments was done as intended. The animals were docile and did not require sitters beyond the immediate operative period. Complication includes leg injury, graft infection, gastrointestinal bleeding, intravenous line disconnection, weight loss, renal failure, red urine, (one for each) and pulmonary failure in two. Activated clotting time was adjusted via continuous intravenous heparin to 150-200 seconds. Reliable hemodynamics and biocompatibility data were collected for evaluate pediatric intracorporeal VADs in the animal model. The juvenile sheep model is reliable, reproducible, and translatable for testing pediatric VADs. These experiments provided vital information for improvement of the devices and for clinical application in the future.

Salvage of compromised free flaps in trauma cases with combined modalities

Using the microsurgical technique for reconstruction in trauma cases represents a challenge for the reconstructive surgeon. Several methods of salvaging of a compromised free flap have been reported, among them: intravenous heparin washing, thrombolitic therapy, thrombectomy, use of grafts and others. Here, we present our experience from nine cases and a review of the literature regarding the use of various modalities for free flap salvage in trauma cases, and their results. Data was collected from trauma cases in our institutions over a period of 2 years, where reconstruction was performed using microsurgical techniques, and where subsequent complications required some type of salvage procedure. The techniques that were used for the salvage included: intravascular irrigation with heparin, papaverine and lidocaine; administration of continuous intravenous heparin, use of the Fogarty catheter, flap washing with streptokinase, and adventitia stripping. The free flaps used were latissimus dorsi, serratus anterior, and the anteromedial thigh flap. Either vein or artery thromboses were identified during the procedure or immediately after surgery in seven patients. Two patients had prolonged spasms of the recipient artery with low flow. In all cases, the No. 2 Fogarty catheter was used for thrombectomy and also for release of the vessel spasm. There was only one complete failure among these patients, and partial necrosis was encountered in three. From our experience and review of the literature, we offer an algorithm for determining treatment strategies in a range of flap salvage situations.

Endovascular repair of symptomatic abdominal aortic aneurysm complicated by postoperative acute myocardial infarction with cardiogenic shock

Dr. Reinhard Kopp, MD Chirurgische Klinik und Poliklinik LMU Munchen – Klinikum Groshadern Marchioninistr. 15 81377 Munich, Germany Sirs: Abdominal aortic aneurysms mostly occur in patients having positive cardiovascular risk factors. Its prevalence increases dramatically with age and is often associated with atherosclerosis and coronary artery disease. Thus perioperative mortality is mainly determined by cardiac events and is much higher in case of emergency. We report on the association of a symptomatic infrarenal aortic aneurysm combined with the most severe cardiac complication, a postoperative myocardial infarction based on a left main stenosis with a cardiogenic shock. A 79-year-old male patient presented with the past medical history of an abdominal aortic aneurysm, multivessel coronary artery disease, recent myocardial infarctions, congestive heart failure, terminal renal failure and diabetes mellitus type 2. His continuous medication consisted of a therapy according to the guidelines with aspirin, -blocker (Carvedilol), statin (Atorvastatin), ACE inhibitor (Ramipril) and diuretics (Furosemide). The patient was admitted in December 2004 to a regional district hospital with acute onset of flank and back pain. The treatment with different analgetics was without success. The patient was transmitted to our hospital with the suspicion of a symptomatic abdominal aortic aneurysm. The CT scan showed an acute expansion of the abdominal aortic aneurysm (max. 7.8×8.0×11.3 cm) without dissection or rupture (Fig. 1). The patient was immediately prepared for the vascular intervention and transferred to the operating room. Although the infrarenal aortic neck was short (less than 10 mm) an endovascular aneurysm repair (EVAR) with implantation of a monoiliac stent graft (Cook Zenith 32 mm diameter) occluding the contralateral common iliac artery was performed in combination with a femoro-femoral alloplastic cross-over bypass surgery (Fig. 2). The intervention was performed in general anesthesia and under continuous intravenous heparin application. Intraoperative angiography and also CT angiography 6 days after the EVAR showed complete exclusion of Abbreviations