Systemic Administration Of Heparin Research Articles

Evaluating the Effectiveness of Systemic Heparin During Arteriovenous Fistula Creation by Emulating a Target Trial.

Most of the 800,000 people living with end-stage kidney disease in the United States rely on a functioning vascular access to provide life-sustaining hemodialysis, yet one-third of arteriovenous fistulas experience early failures. Determining the safety and effectiveness of systemic heparin during fistula creation could improve the quality and quantity of life for these vulnerable patients. In this paper, a pragmatic randomized trial was emulated to assess the effect of systemic heparin administration (vs. none) during radiocephalic arteriovenous fistula creation on early bleeding and thrombosis using data from two international multicenter randomized trials performed between 2014 and 2019. Marginal risks were estimated using inverse probability weighted parametric survival analysis and confidence intervals were generated with bootstrapping. A total of 914 patients were enrolled and 61% received systemic heparin; median (IQR) age was 58 (49, 67) years and 45% were on hemodialysis at enrollment. No difference in the risk of bleeding events was observed, with a risk difference (95% CI) at 14 days of -0.1% (-1.6, 1.4). The risk of access thrombosis was lower in the heparin group, with a risk of 3.7% (2.6, 4.8) after heparin and 5.3% (3.4, 7.4) without heparin at 14 days (risk ratio 0.72, 95% CI 0.50, 0.98).

Evidence-Based Approaches to Anticoagulation in Reconstructive Microsurgery-A Systematic Literature Review.

This systematic review addresses the crucial role of anticoagulation in microsurgical procedures, focusing on free flap reconstruction and replantation surgeries. The objective was to balance the prevention of thrombotic complications commonly leading to flap failure, with the risk of increased bleeding complications associated with anticoagulant use. A meticulous PubMed literature search following Evidence-Based-Practice principles yielded 79 relevant articles, including both clinical and animal studies. The full-texts were carefully reviewed and evaluated by the modified Coleman methodology score. Clinical studies revealed diverse perioperative regimens, primarily based on aspirin, heparin, and dextran. Meta-analyses demonstrated similar flap loss rates with heparin or aspirin. High doses of dalteparin or heparin, however, correlated with higher flap loss rates than low dose administration. Use of dextran is not recommended due to severe systemic complications. In animal studies, systemic heparin administration showed predominantly favorable results, while topical application and intraluminal irrigation consistently exhibited significant benefits in flap survival. The insights from this conducted systematic review serve as a foundational pillar towards the establishment of evidence-based guidelines for anticoagulation in microsurgery. An average Coleman score of 55 (maximum 103), indicating low overall study quality, however, emphasizes the need for large multi-institutional, randomized-clinical trials as the next vital step.

Review of Topical Sodium Heparin 1000 IU/g Gel in Symptomatic Uncomplicated Superficial Thrombophlebitis.

Heparin, a mixture of sulfated polymorphic polysaccharides (glycosaminoglycan) chains of variable lengths and weights and a natural anticoagulant, is widely used in medical practice to prevent intravascular blood coagulation. Heparin has demonstrated antithrombotic and anti-inflammatory activity, and it is mostly administered systemically (intravenously or subcutaneously) for primary or secondary prevention of venous thromboembolism after surgical interventions, or immobilized patients, or on short-term antithrombotic therapy of patients with atrial fibrillation who must undergo treatment. However, since systemic administration of heparin could be, in certain cases, linked to an increased risk of bleeding, topical heparin is widely used for the prevention and treatment of local symptoms of peripheral vascular disorders, such as venous insufficiency, varicose veins, or superficial thrombophlebitis. This review summarizes the main safety and efficacy characteristics of the topical formulation of Heparin in Gel form (1000 International Units of Heparin/g Gel) currently in use, which has demonstrated an excellent efficacy and tolerability profile in reducing signs and symptoms of peripheral vascular disease, e.g., varicose syndromes and their complications, phlebothrombosis, thrombophlebitis, superficial periphlebitis, varicose ulcers, for post-operative varicophlebitis, sequelae of saphenectomy, for traumas and contusions, local edemas and infiltrates, subcutaneous hematoma and for traumatic affections of musculotendinous and capsuloligamentous apparatuses.

Microsurgical training in vein anastomoses: the use of systemic heparin in a rat model.

To investigate whether the use of systemic heparin could be useful for vein microvascular anastomoses in microsurgical training on rats. Femoral end-to-end venous anastomoses were performed on both thighs of 40 wistar rats by two microsurgery trainees from October 2018 to February 2019 (80 anastomoses in total). We divided the rats into 2 groups of 20 specimens (40 femoral end-to-end anastomoses) each: group A received no heparin administration; group B received subcutaneous systemic heparin administration before starting dissection. We compared both vein patency after the procedures. Patency tests showed no difference between the two groups after 5 minutes. At the delayed test after 120 minutes, vein patency was significantly better in the systemic heparin group (85,0% vs 55,0%). Even though both trainees judged practicing on both groups very instructive, they found useful performing anastomoses when heparin was administrated. We suggest including the use of systemic heparin in microsurgery training programs, especially for the beginners. Systemic heparin administration in rat models is educative for trainees.

The Impact of Heparin on Mortality Following Open Ruptured Abdominal Aortic Aneurysm Repair

Systemic administration of heparin is widely used in patients undergoing open elective abdominal aortic aneurysm (AAA) repair. However, no clear consensus exists in the use of intraoperative heparin during open ruptured AAA (rAAA) repair. In this study, we assessed the safety of intravenous heparin administration in patients undergoing open rAAA repair. A retrospective cohort study comparing patients who received and did not receive heparin during open rAAA repair in the Vascular Quality Initiative database between 2003 and 2020 was conducted. The primary outcomes were 30-day and 10-year mortality. The secondary outcomes included estimated blood loss, number of packed red blood cells transfused, early postoperative transfusions, and postsurgical complications. Propensity score matching was used to adjust for potentially confounding variables. The outcomes were compared between the 2 groups using relative risk for binary outcomes and paired t-test and the Wilcoxon rank-sum test for normally and non-normally distributed continuous variables, respectively. Survival was examined using Kaplan-Meier curves and compared using a Cox proportional hazards model. A total of 2,410 patients who underwent open rAAA repair between 2003 and 2020 were studied. Of the 2,410 patients, 1,853 patients received intraoperative heparin and 557 did not. Propensity score matching on 25 variables yielded 519 pairs for the heparin to no heparin comparison. Thirty-day mortality was lower in the heparin group (risk ratio: 0.74; 95% confidence interval [CI]: 0.66-0.84) and in-hospital was also lower in the heparin group (risk ratio: 0.68; 95% CI: 0.60-0.77). Furthermore, estimated blood loss was 910mL (95% CI: 230mL to 1,590mL) lower in the heparin group and the mean number of packed red blood cells transfused intraoperatively and postoperatively were 17 units lower in the heparin group (95% CI: 8-42). Ten-year survival was higher for patients who received heparin, and their rate of survival was approximately 40% higher than those who did not receive heparin (hazard ratio: 0.62; 95% CI, 0.53-0.72; P<0.0001). In patients who received systemic heparin administration at the time of open rAAA repair, there were significant short-term and long-term survival benefits within 30days and at 10years. Heparin administration may have afforded a mortality benefit or been a surrogate for healthier and less moribund patients at the time of the procedure.

Systemic Heparin Administration Versus No Heparin in Open Ruptured Abdominal Aortic Aneurysm Repair: A Propensity Score-matched Analysis

The role of systemic heparin administration at the time of open ruptured abdominal aortic aneurysm repair remains unknown. Our objectives were to compare postoperative outcomes in patients receiving nonfractionated heparin versus no heparin at the time of open ruptured abdominal aortic aneurysm (rAAA) repair in the Vascular Quality Initiative database. All patients who underwent open repair of rAAA between 2003 and 2020 in the Vascular Quality Initiative database were identified. 1:1 propensity score (PS) matching on 25 clinically relevant covariates was performed to match patients who received heparin to those who did not receive heparin. The primary outcome was all-cause mortality. The secondary outcomes were safety end points and included postoperative mortality, blood loss volume, number of packed red blood cell (pRBC) transfused, and complications (cardiac, renal, and respiratory). Survival was examined using Kaplan-Meier curves and compared using a Cox-proportional hazard model. Of 2410 patients that underwent open rAAA between 2003-2020, 1853 received heparin and 557 did not receive heparin. Before PS matching, patients that received heparin were younger (71.4 years vs 73.1 years), and less likely to present a American Society of Anesthesiologists class V at the time surgery (37.5% vs 48.7%). After PS matching, 519 pairs of patients had similar baseline characteristics and presentation (Table). Postoperative mortality was lower in the heparin group (37.6% vs 55.3%; P < .001). Estimated blood loss was 850 mL (95% confidence interval [CI], –350 to –1375 mL) lower in the heparin group and the median number of pRBC transfused was 2 units lower in the heparin group (interquartile range, –1 to –2.5; P < .001). There were no differences in postoperative renal dysfunction, respiratory failure, or congestive heart failure between the two groups. Overall, long-term survival was higher for patients who received heparin (hazard ratio, 0.62; 95% confidence interval, 0.53-0.72; P < .0001) at 10 years (Figure). Patients who received systemic heparin administration at the time of open rAAA repair showed significant survival benefit within 30 days and at 10 years. Heparin administration may have afforded a mortality benefit or been a surrogate for healthier and less moribund patient at the time of the procedure. Importantly, the administration of heparin did not result in increased bleeding or postoperative complications in this high-risk cohort.TableBaseline characteristics of patients before and after propensity score (PS) matchingAll patientsPS-matched patientsNo heparin (n = 557)Heparin (n = 1853)SMDNo heparin (n = 519)Heparin (n = 519)SMDDemographics Age, years, mean (SD)73.13 (8.73)71.47 (9.55)0.1872.99 (8.82)72.98 (9.10)<0.001 Female139 (25.0)421 (22.7)0.052131 (25.2)125 (24.1)0.027 Race0.0480.055Non-Whitea26 (7)103 (5.6)24 (4.6)19 (3.7)White509 (91.4)1668 (90.0)473 (91.1)475 (91.5)Unknown22 (3.9)82 (4.4)22 (4.2)25 (4.8) BMI, kg/m2, mean (SD)28.19 (5.80)28.14 (6.16)0.00928.22 (5.88)28.35 (6.30)0.021Comorbidities Hypertension421 (75.6)1426 (77.0)0.032391 (75.3)392 (75.5)0.004 Congestive heart failure44 (7.9)161 (8.7)0.02943 (8.3)41 (7.9)0.014 Chronic obstructive pulmonary disease162 (29.1)599 (32.3)0.07158 (30.4)156 (30.1)0.008 Preoperative creatinine, mg/dL, mean (SD)1.44 (0.83)1.38 (0.75)0.0691.44 (0.86)1.44 (0.74)0.01 Dialysis5 (0.9)12 (0.6)0.0295 (1.0)7 (1.3)0.036 Preoperative smoking status0.2690.055Never110 (19.7)297 (16.0)101 (19.5)105 (20.2)Prior175 (31.4)604 (32.6)166 (32.0)176 (33.9)Current238 (42.7)922 (49.8)228 (43.9)216 (41.6)Missing34 (6.1)30 (1.6)24 (4.6)22 (4.2) Prior coronary revascularization0.4410.088None283 (50.8)1207 (65.1)274 (52.8)265 (51.1)PCI or CABG81 (14.5)351 (18.9)79 (15.2)96 (18.5)Missing193 (34.6)295 (15.9)166 (32.0)158 (30.4) Prior aortic surgery40 (7.2)220 (11.9)0.1640 (7.7)39 (7.5)0.007Clinical presentation Hemoglobin, mg/dL, mean (SD)11.11 (2.29)11.68 (2.37)0.24511.15 (2.30)11.15 (2.28)0.004 Maximum AAA diameter, mm, mean (SD)79.82 (18.96)78.01 (31.77)0.06979.83 (19.12)81.55 (48.98)0.046 Concomitant iliac aneurysm115 (20.6)405 (21.9)0.03110 (21.2)121 (23.3)0.051 Mental status at presentation0.5240.032Normal298 (53.5)1425 (76.9)291 (56.1)292 (56.3)Disoriented108 (19.4)229 (12.4)102 (19.7)107 (20.6)Unconscious151 (27.1)199 (10.7)126 (24.3)120 (23.1) Systolic blood pressure <70 mm Hg278 (49.9)1361 (73.4)0.499274 (52.8)275 (53.0)0.004 Cardiac arrest150 (26.9)161 (8.7)0.491118 (22.7)110 (21.2)0.037 ASA class0.490.03811 (0.2)4 (0.2)1 (0.2)1 (0.2)22 (0.4)12 (0.6)2 (0.4)3 (0.6)320 (3.6)123 (6.6)19 (3.7)21 (4.0)4164 (29.4)886 (47.8)161 (31.0)159 (30.6)5271 (48.7)695 (37.5)251 (48.4)253 (48.7)Missing99 (17.8)133 (7.2)85 (16.4)82 (15.8) Time from symptom onset to incision, hours, mean (SD)16.65 (55.41)22.01 (47.19)0.10417.16 (57.28)16.45 (28.89)0.016Preoperative medications Aspirin203 (36.4)758 (40.9)0.092190 (36.6)199 (38.3)0.036 P2Y12 antagonist30 (5.4)176 (9.5)0.15730 (5.8)29 (5.6)0.008 Statin220 (39.5)780 (42.1)0.053205 (39.5)215 (41.4)0.039 Beta blocker229 (41.1)810 (43.7)0.053217 (41.8)212 (40.8)0.02 Anticoagulant or ACE-I/ARB0.480.03No216 (38.8)963 (52.0)211 (40.7)217 (41.8)Yes130 (23.3)574 (31.0)127 (24.5)128 (24.7)Missing211 (37.9)316 (17.1)181 (34.9)174 (33.5)Values are reported as number (%) unless otherwise indicated.AAA, Abdominal aortic aneurysm; ACE-I, angiotensin-converting enzyme inhibitor; ARB, angiotensin II receptor blocker; ASA, American Society of Anesthesiologists; BMI, body mass index; CABG, coronary artery bypass graft; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; PCI, percutaneous coronary intervention; P2Y12, purinergic receptor; SD, standard deviation; SMD, standardized mean difference.aNon-White race includes Asian, Black, American Indian, Alaskan Native, Native Hawaiian, or other Pacific Islander. Open table in a new tab

Effectiveness of antithrombotic prophylaxis in paediatric cardiosurgical patients

Aim. To evaluate the effectiveness of prevention measures for thrombotic catheter-associated events in the perioperative management of patients undergoing cardiac surgery.Methods. A total of 433 paediatric and neonatal patients were included in the study during the period from January to December 2018. All patients received antithrombotic prophylaxis via systemic heparin administration.Results. Thirty-six patients displayed signs of thrombosis during the postoperative period (8.31%): 28 patients had venous thrombosis, while 6 had the Blalock-Taussig shunt thrombosis, and 2 had arterial thrombosis. The mortality rate was higher in the group with registered thrombosis than in the group without thrombosis (p = 0.01).Conclusion. The dosage regimen for children and neonatal patients should be according to age-associated antithrombotic drug standards. It requires an integral approach for evaluating the effectiveness of preventive and therapeutic measures. Received 25 August 2020. Revised 18 December 2020. Accepted 22 December 2020. Funding: The study did not have sponsorship. Conflict of interest: Author declares no conflict of interest.

SS15. Short- and Long-term Cost and Outcome Comparison of Systemic Heparin Therapy Versus Catheter-Directed Thrombolysis for the Treatment of Massive and Submassive Pulmonary Embolism

Pulmonary embolism (PE) is a significant disease process that affects an estimated 117 cases per 100,000 person-years. Long-term complications are associated with acute PE; the most serious of these complications is chronic pulmonary hypertension, which has a significant cost to treat, ranging from US $98,000 to $117,000. This study evaluated catheter-directed thrombolysis (CDT) compared with systemic heparin administration in regard to patient outcomes, short-term cost, and long-term cost in a single center. The objective of this study was to compare systemic heparin administration and CDT and to evaluate whether there are advantages in expense or outcomes in one group over the other. A retrospective chart review was conducted of 341 patients who presented with massive or submassive PE and were treated with either systemic heparin therapy or CDT from January 2011 to November 2018. Total costs were determined as the sum of the hospital and professional bills, with long-term cost analysis using a standardized 100-patient model. The groups were then compared for initial and 5-year costs based on the data collected in the study, using chronic pulmonary hypertension rates and expenses determined from the study cohort. Patient outcomes were significantly better for those treated with CDT, with fewer bleeding complications (4.2% vs 13.8%; P = .005), a shorter length of stay (3.44 days vs 6.47 days; P < .001), a greater percentage of patients returning to their prior living conditions (89.0% vs 79.3%; P = .042), and a lower rate of pulmonary hypertension at 12 months (6.3% vs 15.9%; P = .030). The expense of initial admission was significantly higher in the CDT group compared with heparin, with a difference of approximately US $31,000 (P = .001), although analysis showed the heparin group to have a higher cost over time. Analysis showed that the cost to treat a standardized group of 100 patients had an approximated difference of US $1.7 million when the total cost to treat is evaluated at the 5-year time point with a 3.2-year cost to recover. For patients with massive or submassive PE, this study demonstrated a significant long-term cost savings and improved outcomes for patients treated with CDT compared with systemic heparin administration.

Acute Limb Ischemia.

Acute limb ischemia (ALI) is a rapid decrease in lower limb blood flow due to acute occlusion of peripheral artery or bypass graft, and in ALI not only limbs but also life prognosis will be poor unless quick and appropriate treatment is given. The etiology is broadly divided into embolism and thrombosis with various comorbidities. The symptoms of ALI are abrupt with pain, numbness, and coldness of lower limb, and paresthesia, contracture, and irreversible purpura will appear with the exacerbation of ischemia. Severity and treatment strategy should be determined based on physical findings and image findings. Considering life prognosis, limb amputation should be done without hesitation when the limb was diagnosed as irreversible. ALI can be treated by means of open surgical revascularization, endovascular, or hybrid approach with rapid systemic administration of heparin. In any cases, evaluating the lesions by intraoperative angiography and appropriate additional treatment are important. ALI is a serious disease requiring urgent treatment, and it is essential to promptly perform the best initial treatment that can be performed at each facility. (This is a translation of Jpn J Vasc Surg 2018; 27: 109–114.)

Systemic administration of heparin ameliorates radiation-induced oral mucositis\u2014preclinical studies in mice

PurposeThe present study investigates the impact of systemic application of heparins on the manifestation of radiation-induced oral mucositis in a well-established mouse model.Materials and methodsMale C3H/Neu mice were irradiated with either single-dose or fractionated irradiation protocols with 5 × 3 Gy/week, given over one (days 0–4) or two (days 0–4, 7–11) weeks. All fractionation protocols were concluded by a local test irradiation (day 7/14) using graded doses to generate complete dose–effect curves. Daily doses of unfractionated or low molecular weight heparin (40 or 200 I.U./mouse, respectively) were applied subcutaneously over varying time intervals. The incidence and the time course of mucosal ulceration, corresponding to confluent mucositis in patients (RTOG/EORTC grade 3), were analysed as clinically relevant endpoints.ResultsSystemic application of heparins significantly increased the iso-effective doses for the induction of mucosal ulceration, particularly in combination with fractionated irradiation protocols. Moreover, a tentative prolongation of the latent time and a pronounced reduction of the ulcer duration were observed.ConclusionThese data provide the first evidence for a protective and/or mitigative effect of heparins for radiation-induced oral mucositis. Further studies are ongoing investigating the underlying mechanism.

THE EFFICACY OF PLASMA SORPTION (LIVER SUPPORT) IN LIVER FAILURE IN PATIENTS WITH MECHANICAL JAUNDICE

Background: New methods of extracorporeal hemocorrection and detoxification in liver failure of patients with mechanical jaundice need an assessment of their efficacy and safety, especially with consideration of baseline hypocoagulation and systemic heparin administration. Aim: To assess the efficacy of plasma sorption with Plasorba BR-350 in liver failure patients with mechanical jaundice. Materials and methods: The study was conducted in 12 patients (aged from 47 to 67 years) with mechanical jaundice as a consequence of biliary obstruction (choledocholithiasis). At baseline, total bilirubin level was from 101.9 to 611 µmol/l. Extracorporeal hemocorrection (The Liver Support procedures) was carried out with the Octo Nova device (Asahi Kasei Medical, Japan) and Plasorba BR-350 sorbent based on were measured prior, during and upon termination of a procedure. Results: By the end of the procedure, there was a trend towards decrease in total bilirubin level by 18.6 ± 3.8% (p = 0.13), conjugated bilirubin by 14.6 ± 6.4% (p = 0.06), unconjugated bilirubin by 16.9 ± 9.8% (p = 0.17), and aspartate aminotransferase by 18.67 ± 2.3% (p = 0.077), with a statistically significant decrease in alanine aminotransferase 17.07 ± 3.4% (p = 0.002). Other blood chemistry parameters did not show any changes. There were no changes in hemoglobin and platelets throughout the study and no negative changes in the international normalized ratio, activated partial thromboplastin time, and fibrinogen, prothrombin, and anti-thrombin III levels. During hemosorption procedures no bleeding complications were noted in any patient. Conclusion: Plasma sorption (Liver Support) allows for correction of hyperbilirubinemia in liver failure patients with mechanical jaundice without a significant influence on other blood chemistry parameters. Due to the absence of bleeding complications during the procedure and lack of chang- es in the coagulogram after the procedure, this method of the liver support can be recommended for patients with high bilirubin levels in mechanical jaundice during preparation for surgical treatment for the bile ducts obstruction and postoperatively.

Recent advancements in and views on the donor operation in living donor liver transplantation: a single-center study of 886 patients over 13 years.

Donor safety remains an important concern in living donor liver transplantation (LDLT). In the present study, we assessed recent advancements in the donor operation for LDLT through our experience with this procedure. A total of 886 donor hepatectomies performed between January 1999 and December 2012 were analyzed. Three chronological periods were investigated: the initial period (1999-2004, n = 239), the period in which the right liver with middle hepatic vein reconstruction was primarily used (2005-2010, n = 422), and the period in which the right liver with a standardized protocol, including a preoperative donor diet program, an evaluation of steatosis with magnetic resonance spectroscopy, no systemic heparin administration or central venous pressure monitoring, exact midplane dissection, and incremental application of minimal incisions, was exclusively used (2011-2012, n = 225). The proportion of patients > 50 years old increased (2.5% versus 4.7% versus 8.9%), whereas the proportion of patients with a remnant liver volume ≤ 30% (6.5% versus 13.9% versus 6.3%) and with macrosteatosis ≥ 10% (7.9% versus 11.1% versus 4.4%) decreased throughout the periods. The operative time (292.7 versus 290.0 versus 272.8 minutes), hospital stay (12.4 versus 11.2 versus 8.5 days), and overall morbidity rate (26.4% versus 13.3% versus 5.8%), including major complications (>grade 3; 1.7% versus 1.9% versus 0.9%) and biliary complications (7.9% versus 5.0% versus 0.9%), were markedly reduced in the most recent period. No intraoperative transfusion was required. No cases of irreversible disability or mortality were noted. In conclusion, the quality of the donor operation has recently been standardized through a large volume of experience, and the operation has been proven to have minimal risk. However, a constant evaluation of our experience is critical for remaining prepared for any unavoidable crisis.

A strategy to improve current MSC-based therapies (TECH1P.833)

Abstract Mesenchymal stem cell (MSC) hold promise in the therapy of many inflammatory and degenerative disease. However, result from recent clinical trials using these cells are disappointing, suggesting that current MSC-based therapies need to be improved. We previously demonstrated that, immediately after their contact with serum following infusion, MSCs active complement of the innate immunity and are injured by the activated complement despite the presence of native cell surface complement regulators. In this work, we found that systemic administration of heparin, a widely used drug which is also a potent complement inhibitor, protects MSCs from serum-mediated damage after i.v. infusion. To minimize the side effects of systemic heparin administration, we also developed a method to paint heparin onto the surface of MSCs, We found that chemically modified heparin can be painted onto MSCs, and that these heparin-painted MSCs are better protected from serum (complement)-medicated attack and retain better immunosuppressive activity than regular MSCs. These data suggest that the cell surface engineering of MSC with heparin would be a simple and effective approach to improve the outcomes of current MSC-based clinical trials.

Outcomes After Heparin-Induced Thrombocytopenia in Patients With Propaten Vascular Grafts

Heparin-induced thrombocytopenia (HIT) can result in a life- or limb-threatening condition that can be reversed with early detection and prompt discontinuation of systemic heparin. The advent of heparin-bonded grafts may introduce a new level of complexity in some patients with a suspected diagnosis of HIT. This review evaluates the outcomes of patients who received the Gore Propaten vascular graft with a subsequent suspicion of HIT. This is a retrospective analysis of cases with suspected type II HIT after implant of the Propaten vascular graft that were reported to W.L. Gore & Associates. Data reviewed included clinical studies, including physician-sponsored studies, both inside and outside the United States; published literature; and Gore's product surveillance records. Overall, as of June 2011, there have been 27 cases (27 patients and 30 vascular grafts) of suspected HIT after graft implant. Of these 27 patients, 18 were tested for HIT antibodies (enzyme-linked immunosorbent assay, heparin-induced platelet activation test, serotonin release assay, drug-induced platelet activation test, platelet aggregation test, an HIT panel, or an unknown HIT test), with a positive test result in 17 of the 18 cases. In 5 of the 18 cases, patients were tested with two distinct HIT assays, resulting in one positive and one negative test. Among patients with available data, the mean preoperative heparin dose was 4850 ± 1634 U, and four patients had a postoperative heparin drip. The mean preoperative platelet count was 227,000 ± 71,616. Mean platelet count at time of diagnosis of HIT was 53,429 ± 36,832. For the majority of those patients known to have had heparin discontinued once HIT was suspected, Argatroban was the anticoagulant of choice. Sixteen patients had grafts that remained implanted and in circulation, eight patients had grafts that were explanted, two patients had grafts that were ligated in situ, and the outcome was unknown for one patient. Among the 16 patients with grafts remaining in circulation, four grafts required thrombectomy for occlusion. Two patients died, one other patient had a remote thrombotic event, and the remaining patients had no reported adverse events. Among the 10 patients with graft removal or ligation, six had a graft occlusion, four required an amputation, and two died. Among the cases in which the recovery of platelet count was reported after systemic heparin was discontinued, the majority were cases in which the grafts were left in circulation. Analysis of the cases of suspected HIT in patients with implanted Propaten vascular grafts reveals that the HIT observed appears to be related to the systemic administration of heparin. After discontinuation of systemic heparin, platelet counts normalized in the presence of patent Propaten vascular grafts. Hence, based on current data, our recommendation would be to tailor treatment to individual patients. Functioning grafts in patients with or without thrombotic events and return of platelet count to normal values may not require grafts to be explanted in the presence of HIT.

Pediatric Airway Scope Is Available for Gastric Tube Insertion in Adult Patients

To the Editor: In our anesthetic management of coronary artery surgery, gastric tube (GT) insertion is a routine practice after intubation. Occasionally, a small mucosal injury caused by the blind insertion of a GT (including postcricoid ulceration and vocal cord paralysis 1 ) may induce massive hemorrhage because of the systemic administration of heparin during cardiac surgery. To avoid this complication, the GT insertion preferably should be performed under visual control during the GT advancement. Until recently, most visualization devices, including the Airway Scope (AWS; Pentax-AWS, Hoya, Tokyo, Japan), limited the oropharyngeal manipulations because narrowing of the oropharyngeal space by the endotracheal tube interferes with the advancement of the laryngoscope and decreases visibility of the posterior larynx. Recently, a new AWS blade for children, which is smaller than that for adults, has been made available for pediatric endotracheal intubation. This blade also can pass through a narrow upper airway and visualize the hypopharynx in adult anesthetized, endotracheally intubated patients. We report the use of this new pediatric blade for the insertion of the GT in an endotracheally intubated adult patient. A 73-year old woman (height, 1.71 m; weight, 53.1 kg) was scheduled to undergo cardiac surgery. After anesthesia induction and paralysis, the trachea was intubated with an 8.0-mm internal diameter orotracheal tube. For oral insertion of the GT, a 16 F, 122 cm, Argyle Salem Sump tube (Coviden, Dublin, Ireland) was attached to the main channel of the pediatric blade of the AWS (Fig 1). The pediatric blade was placed smoothly into the oral cavity and advanced to the hypopharynx. When a good view of the hypopharynx was obtained, the GT was advanced under the arytenoid cartilage through the inlet of the esophagus and introduced into the stomach. No mucosal injury or bleeding was noted during withdrawal of the blade. Successful placement of the GT was checked by aspiration of the gastric juice using vacuum suction. Ikeno et al 2 reported that the AWS facilitated GT placement in anesthetized patients. The AWS blade for adults might be placed between the endotracheal tube and the epiglottis. In such cases, a view of the hypopharynx, including the inlet of the esophagus, cannot always be obtained. Therefore, a small and compact pediatric blade is more suitable for oropharyngeal manipulations and viewing of the hypopharynx.

Regional citrate anticoagulation for hemorrhage experiments in rats

IntroductionHemorrhage alone without concomitant trauma often results in a hypercoagulable state that makes it difficult to prevent clotting within the blood withdrawal catheters. Although systemic administration of heparin can ameliorate this problem, heparin use has many additional actions that may confound interpretation of the hemorrhage experiments. The problem can be resolved by the use of a dual lumen catheter that anticoagulates only the blood within the withdrawal circuit. We describe the design of such a catheter and evaluate its function in studies of hemorrhagic shock in rats. Materials and methodsConstruction directions are provided for the dual lumen catheter along with a commercial source. The catheters were connected to computer controllable infusion syringes. Either citrate or heparin was used for regional extracorporeal anticoagulation. Rats were anesthetized and hemorrhaged to 40mmHg for more than 15min through the use of a computer program written in Labview. Ionized calcium measurements were obtained pre- and posthemorrhage. ResultsThe catheters remained patent throughout the experiments. There was no significant difference in the ionized calcium whether citrate or heparin was used for extracorporeal anticoagulation. ConclusionThe dual lumen catheters are suitable for the study of hemorrhagic shock in rats without the need for systemic anticoagulation. The catheters can be used with computer-controlled hemorrhage procedures.

Erratum to: No need for systemic heparinization during laparoscopic donor nephrectomy with short warm ischemia time

Systemic heparin administration during laparoscopic donor nephrectomy (LDN) may prevent microvascular thrombus formation following warm ischemia. We herein present our experience with and without systemic heparinization during LDN.We retrospectively reviewed donor complications and graft outcomes in 119 consecutive live donor kidney transplantations between January 2005 and December 2009. Systemic heparin was administered to the first 65 donors. LDN was carried out by 2 surgeons using a pure laparoscopic technique.Total operating time for LDN was significantly longer in the heparin group (202 vs. 157 min). The incidence of renal artery multiplicity was significantly higher in the heparin group. Mean warm ischemia time was 160 s, and mean hospital stay was 5 days with no differences between groups. Postoperative hemorrhage occurred in 3 donors with systemic heparinization and in 1 without heparinization. Two donors received blood transfusions, and 2 underwent laparoscopic reexploration. Three grafts were lost in the heparin group and 1 in the non-heparin group. Graft loss was due to early vascular thrombosis (n = 3) and due to acute rejection (n = 1). Overall, 1-year graft survival was 96.6%, and 1-year serum creatinine was 1.41 mg/dl (P = n. s. between groups).Abandoning systemic donor heparinization in LDN with short warm ischemia has a low complication rate without adverse effects on short- and long-term graft outcomes.

SS6. Predictors of Late Mortality Using Propensity Score Matched Comparison of Open and Endovascular Revascularization for Chronic Mesenteric Ischemia

gated in situ in 1, and the outcome was unknown for 1 patient. Among patients with grafts remaining in circulation (16), 2 expired, 3 others required thrombectomy for graft occlusion, and the other 11 patients had no reported adverse events. Among the 7 patients with graft removal/ligation, 3 required an amputation (2 major, 1 minor) and 2 different patients expired secondary to a pulmonary embolism. Conclusions: Analysis of the cases with implanted propaten grafts reveals that the HIT appears to be related to the systemic administration of heparin, as the platelet count normalized following discontinuation of the systemic heparin. Hence, based on current data, our recommendation would be to tailor treatment to individual patients. Functioning grafts in patients with or without thrombotic events and return of platelet count to normal values may not require grafts to be explanted.

No need for systemic heparinization during laparoscopic donor nephrectomy with short warm ischemia time

Systemic heparin administration during laparoscopic donor nephrectomy (LDN) may prevent microvascular thrombus formation following warm ischemia. We herein present our experience with and without systemic heparinization during LDN. We retrospectively reviewed donor complications and graft outcomes in 119 consecutive live donor kidney transplantations between January 2005 and December 2009. Systemic heparin was administered to the first 65 donors. LDN was carried out by 2 surgeons using a pure laparoscopic technique. Total operating time for LDN was significantly longer in the heparin group (202 vs. 157min). The incidence of renal artery multiplicity was significantly higher in the heparin group. Mean warm ischemia time was 160s, and mean hospital stay was 5days with no differences between groups. Postoperative hemorrhage occurred in 3 donors with systemic heparinization and in 1 without heparinization. Two donors received blood transfusions, and 2 underwent laparoscopic reexploration. Three grafts were lost in the heparin group and 1 in the non-heparin group. Graft loss was due to early vascular thrombosis (n=3) and due to acute rejection (n=1). Overall, 1-year graft survival was 96.6%, and 1-year serum creatinine was 1.41mg/dl (P=n. s. between groups). Abandoning systemic donor heparinization in LDN with short warm ischemia has a low complication rate without adverse effects on short- and long-term graft outcomes.

Postoperative pulmonary embolism in a three year old with Klippel&amp;ndash;Trenaunay syndrome

Massive pulmonary embolism (PE) in a small child is a rare event and unified guidelines for its treatment are missing. Timely diagnosis and management of massive pulmonary embolism is of crucial importance for a good outcome. We describe a unique management of PE causing oxygenation failure using a combination of catheter extraction technique, and regional thrombolysis on top of systemic heparin administration and inferior vena cava filter placement. Pulmonary hypertension was treated with inhaled nitric oxide. We believe that catheter extraction technique and regional thrombolysis is an option to consider provided that resources and expertise are available. Preoperative placement of an inferior vena cava filter should be contemplated in such high risk situations.