Venous thrombosis after long-haul flights

BACKGROUND: The risk for venous thromboembolism after long-haul flights represents a controversial issue. The aim of our study was to assess the incidence of venous thrombosis associated with long-haul flights in a prospective, controlled cohort study. METHODS: We included 964 passengers returning from long-haul flights (flight duration, > or =8 hours) and 1213 nontraveling control subjects. We excluded participants who were being treated with anticoagulant drugs or who used compression stockings. Main outcome measures were the incidence of ultrasonographically diagnosed thrombosis in the calf muscle and deep veins, symptomatic pulmonary embolism, and death. RESULTS: We diagnosed venous thrombotic events in 27 passengers (2.8%) and 12 controls (1.0%) (risk ratio [RR], 2.83; 95% confidence interval [CI], 1.46-5.49). Of these, 20 passengers (2.1%) and 10 controls (0.8%) presented with isolated calf muscle venous thrombosis (RR, 2.52; 95% CI, 1.20-5.26), whereas 7 passengers (0.7%) and 2 controls (0.2%) presented with deep venous thrombosis (RR, 4.40; 95% CI, 1.04-18.62). Symptomatic pulmonary embolism was diagnosed in 1 passenger with deep venous thrombosis (P =.44). All of these individuals had normal findings at baseline ultrasonography. Passengers with isolated calf muscle venous thrombosis or deep venous thrombosis had at least 1 risk factor for venous thrombosis (>45 years of age or elevated body mass index in 21 of 27 passengers). The follow-up after 4 weeks revealed no further venous thromboembolic event. CONCLUSIONS: Long-haul flights of 8 hours and longer double the risk for isolated calf muscle venous thrombosis. This translates into an increased risk for deep venous thrombosis as well. In our study, flight-associated thrombosis occurred exclusively in passengers with well-established risk factors for venous thrombosis.     

The LONFLIT4-Venoruton Study: a randomized trial--prophylaxis of flight-edema in venous patients

The aim of this independent study was to evaluate the protective effects, on the development of flight edema, of Venoruton. The study included patients with venous disease traveling in economy in long-haul flights (9 hours). Edema is a relevant aspect of long-haul flights affecting both patients with venous disease and normal subjects. Microcirculatory variations during flights cause a microangiopathy and biochemical and coagulation alterations. This condition may be defined as flight microangiopathy. A group of 203 subjects with chronic venous disease (uncomplicated varicose veins) at low-medium risk for DVT were contacted; 43 subjects were excluded for several nonmedical, travel-related problems or inconvenient evaluation time; the remaining 160 were randomized, after informed consent, into 2 groups to evaluate 2 prophylaxes in 7-8-hour, long-haul flights: The treatment group received Venoruton (hydroxyethyl rutosides) 1 g twice daily for 3 days (2 days before the flight and the day of the flight). The control group received comparable placebo. The edema score was based on the edema tester, ankle circumference, volume measurements, subjective swelling, and discomfort score. Items 1, 4, and 5 are based on an analogue scale line (1 to 10) directly defined by the subjects before and after the flights. Of the 160 included subjects 139 completed the study. Dropouts (21) were due to poor compliance, traveling, and/or connection problems (11 in the control group, 10 in the treatment group). Age and sex distribution were comparable in the 2 groups as were risk factors distributions. The level of edema at inclusion was comparable in the 2 groups of subjects. After the flight there was an average score of 7.2 (sd 2) in the control group, while in the Venoruton group the score was on average 3.2. (sd 1.1) (p < 0.05), 2.25 times lower than in the control group (p < 0.05). In the control group 89% of the subjects had an evident increase in ankle circumference and volume, which was clearly visible at inspection and associated with discomfort. In the Venoruton group edema was clearly present in 12% of subjects (associated with discomfort between 5 and 7 on the analogue scale line) and it was mild-moderate, not associated with symptoms (pain, discomfort between 2 and 4 on the analogue scale line). Therefore, the control of flight edema with Venoruton was clear both considering parametric data (circumference and volume) and nonparametric (analogue scale lines) measurements. The combined evaluation of the edema score is significantly favorable for patients treated with Venoruton. No deep vein thrombosis or superficial vein thrombosis was observed in this study.     

Travel, venous thromboembolism, and thrombophilia

Current evidence indicates that prolonged air travel predisposes to venous thrombosis and pulmonary embolism. An effect is seen once travel duration exceeds 6 to 9 hours and becomes obvious in long-haul passengers traveling for 12 or more hours. A recent records linkage study found that increase in thrombosis rate among arriving passengers peaked during the first week and was no longer apparent after 2 weeks. Medium- to long-distance travelers have a 2- to 4-fold increase in relative thrombosis risk compared with nontravelers, but the averaged absolute risk is small (approximately one symptomatic event per 2 million arrivals, with a case-fatality rate of approximately 2%) and there is no evidence that thrombosis is more likely in economy class than in business- or first-class passengers. It remains uncertain whether and to what extent thrombosis risk is increased by short-distance air travel or prolonged travel by motorcar, train, or other means. Most travelers who develop venous thrombosis or pulmonary embolism also have one or more other predisposing risk factors that may include older age, obesity, recent injury or surgery, previous thrombosis, venous insufficiency, malignancy, hormonal therapies, or pregnancy. Limited (though theoretically plausible) evidence suggests that factor V Leiden and the prothrombin gene mutation predispose to thrombosis in otherwise healthy travelers. Given that very many passengers with such predispositions do not develop thrombosis, and a lack of prospective studies to link predisposition with disease, it is not now possible to allocate absolute thrombosis risk among intending passengers or to estimate benefit-to-risk ratios or benefit-to-cost ratios for prophylaxis. Randomized comparisons using ultrasound imaging indicate a measurable incidence of subclinical leg vein thrombosis after prolonged air travel, which appears to increase with travel duration and is reduced by graded pressure elastic support stockings. Whether this surrogate outcome measure translates into clinical benefit remains unknown, but support stockings are likely to be more effective and have less adverse effects than the use of aspirin.     

Prevention of venous thrombosis and thrombophlebitis in long-haul flights with pycnogenol.

The aim of this study was to evaluate the occurrence of deep venous thrombosis (DVT) and superficial vein thrombosis (SVT) and its prophylaxis with an oral anti-edema and antithrombotic agent (Pycnogenol, Horphag, Research Management SA, Geneva, Switzerland) in long-haul flights, in subjects at moderate to high-risk of DVT and SVT. The study pre-included 244 pre-selected subjects; 211 were included (33 were excluded for several reasons due to logistic problems) and 198 completed the study; 13 subjects were lost for follow-up at the end of the flight, all for non-medical problems (i.e., for difficult connections). All subjects were scanned within 90 minutes before the flight and within 2 hours after disembarking. Subjects were supplemented with 100 mg Pycnogenol per capsule. Treatment subjects received two capsules between 2 and 3 hours before flights with 250 mL of water; two capsules were taken 6 hours later with 250 mL of water and one capsule the next day. The control group received comparable placebo at the same intervals. The flight duration was on average 8 hours and 15 minutes (SD 55 min) (range, 7.45-12.33). In the control group there were five thrombotic events (one DVT and four superficial thromboses) while only nonthrombotic, localized phlebitis was observed in the Pycnogenol group (5.15% vs. no events; p<0.025). The ITT (intention to treat) analysis detects 13 failures in the control group (eight lost to follow up + five thrombotic events) of 105 subjects (12.4%) vs. five failures (4.7%; all lost, no thrombotic events) in the treatment group (p<0.025). No unwanted effects were observed. In conclusion, this study indicates that Pycnogenol treatment was effective in decreasing the number of thrombotic events (DVT and SVT) in moderate-to-high risk subjects, during long-haul flights.     

Incidence of air travel-related pulmonary embolism at the Madrid-Barajas airport

BACKGROUND: Prolonged air travel and the associated immobilization are risk factors for venous thromboembolism. The occurrence of pulmonary thromboembolism (PTE) under these circumstances is referred to as economy class syndrome. We assessed the incidence of symptomatic PTE in passengers on long-haul flights arriving at Madrid-Barajas Airport, Madrid, Spain, and the association with the number of flight hours. METHODS: We retrospectively reviewed cases of PTE among international travelers arriving at Madrid-Barajas Airport between January 1995 and December 2000. Patients presenting with symptoms of deep venous thrombosis but without symptoms of PTE were excluded. Pulmonary thromboembolism was identified using an algorithm of diagnostic tests. The incidence of PTE and the association with flight duration was assessed. RESULTS: The average number of passengers per year who arrived at the airport on flights originating abroad in the period analyzed was 6 839 222. Sixteen cases of PTE were detected over the 6-year period. All patients with travel-associated PTE had flight durations of greater than 6 hours. The overall incidence of PTE was 0.39 per 1 million passengers (95% confidence interval [CI], 0.20-0.58). On flights that lasted between 6 and 8 hours, the incidence was 0.25 per 1 million passengers (95% CI, 0-0.75), while on flights longer than 8 hours, the incidence was 1.65 per 1 million passengers (95% CI, 0.81-2.49) (P<.001). CONCLUSIONS: Air travel is a risk factor for PTE, and the incidence of PTE increases with the duration of the air travel. However, the low incidence of PTE among long-distance passengers, similar to that observed in other international airports, does not justify social alarm.     

Venous thrombosis from air travel: the LONFLIT3 study--prevention with aspirin vs low-molecular-weight heparin (LMWH) in high-risk subjects: a randomized trial

The LONFLIT1 and 2 studies established that in high-risk subjects after long (>10 hours) flights, the incidence of deep venous thrombosis (DVT) may be between 4% and 6%, The LONFLIT3 study aimed to evaluate methods of prevention in high-risk subjects. Of 467 subjects contacted for the study, 300 were included. These 300 subjects at high risk for DVT were randomized, after informed consent, into three groups: 1) a control group that had no prophylaxis; 2) an aspirin treatment group, in which patients were treated with 400 mg (tablets of oral, soluble aspirin; one dose daily for 3 days, starting 12 hours before the beginning of the flight); and 3) a low-molecular-weight heparin (LMWH) group, in which one dose of enoxaparine was injected between 2 and 4 hours before the flight. The dose was weight-adjusted (1,000 IU [equivalent to 0.1 mL per 10 kg of body weight). Subjects with potential problems due to prophylaxis with aspirin or LMWH or at risk of drug interactions were excluded. Of the 100 included subjects in each group, a total of 249 subjects completed the study (dropouts due to low compliance or traveling/connections problems were 17%). Age and sex distribution were comparable in the three groups as well as risk distributions. Mean age was 47 (range, 28-75; SD, 11; 65% males). Of the 82 subjects in the control group, there were 4.82% of subjects with DVT with two superficial thromboses. In total 4.8% of limbs suffered a thrombotic event. Of 84 subjects in the aspirin treatment group, there were 3.6% of patients with DVT and three superficial thrombosis. In total 3.6% of limbs had a thrombotic event. In the LMWH group (82 subjects), there were no cases of DVT. One superficial thrombosis was documented. In total only 0.6% of limbs had a thrombotic event (p<0.002 in comparison with the other two groups). DVT was asymptomatic in 60% of subjects; 85% of DVTs were observed in passengers in non-aisle seats. Mild gastrointestinal symptoms were reported in 13% of patients taking aspirin. One dose of LMWH is an important option to consider in high-risk subjects during long-haul flights.     

Thrombin activatable fibrinolysis inhibitor and the risk for deep vein thrombosis

Thrombin activatable fibrinolysis inhibitor (TAFI, or procarboxypeptidase B) is the precursor of a recently described carboxypeptidase that potently attenuates fibrinolysis. Therefore, we hypothesized that elevated plasma TAFI levels induce a hypofibrinolytic state associated with an increased risk for venous thrombosis. To evaluate this hypothesis, we developed an electroimmunoassay for TAFI antigen and used this assay to measure TAFI levels in the Leiden Thrombophilia Study, a case-control study of venous thrombosis in 474 patients with a first deep vein thrombosis and 474 age- and sex-matched control subjects. In 474 healthy control subjects, an increase of TAFI with age was observed in women but not in men. Oral contraceptive use also increased the TAFI concentration. TAFI levels above the 90th percentile of the controls (> 122 U/dL) increased the risk for thrombosis nearly 2-fold compared with TAFI levels below the 90th percentile (odds ratio, 1.7; 95% confidence interval, 1.1-2.5). Adjustment for various possible confounders did not materially affect this estimate. These results indicate that elevated TAFI levels form a mild risk factor for venous thrombosis. Such levels were found in 9% of healthy controls and in 14% of patients with a first deep vein thrombosis. Elevated TAFI levels did not enhance the thrombotic risk associated with factor V Leiden but may interact with high factor VIII levels. (Blood. 2000;95:2855-2859)     

Clinical presentations,risk factors,treatment and outcomes in patients with splanchnic vein thrombosis: a single-center experience

Splanchnic vein thrombosis (SVT) is an uncommon form of venous thrombosis. Management can be challenging due to underlying conditions, increased bleeding risk, and lack of evidence from clinical trials. We sought to characterize the presentation and management of patients with SVT at a large tertiary hospital. A total of 43 patients’ electronic medical records were reviewed. Median age at diagnosis was 43 (18–71). Sixteen patients had isolated portal vein thrombosis (37.2 %), and 16 (37.2 %) had thrombosis involving multiple splanchnic veins. Abdominal pain was the most common clinical presentation (67.4 %). Thrombophilia was present in 18 patients (41.9 %), nine had underlying liver disease (20.9 %) and seven had inflammatory bowel disease (16.3 %). Thirty-nine (90.7 %) patients were treated with anticoagulation, and 11(25.6 %) of these patients underwent interventional procedures. Thirty (69.8 %) patients remained on indefinite anticoagulation. Results of follow-up imaging at least 1 month after diagnosis were available for 29 patients; imaging showed chronic, stable thrombosis in 14 patients (48.3 %), resolution of thrombosis in 13 patients (44.8 %) and asymptomatic progression in two patients (6.9 %). Recurrent thrombosis occurred in four patients (9.3 %). Major bleeding occurred in eight patients who received anticoagulation (18.6 %), including fatal subdural hematoma in one patient. In this cohort of patients managed by hematologists and gastroenterologists, the majority of patients were treated with anticoagulation. Interventional procedures were higher than in previously reported series. Our study strongly supports the interdisciplinary management of splanchnic venous thrombosis.     

Up close and personal with deep vein thrombosis

Deep vein thrombosis - the formation of clots in one of the body's deep veins (usually in the lower extremities) - develops as a result of vascular damage to the vein wall, venous stasis, and hypercoagulability (Virchow's triad). Among the many problems it can cause, the condition can escalate the challenge of healing a chronic wound. If a patient presents with pain, swelling, warmth, muscle cramps, and/or redness, the clinician should consider deep vein thrombosis, even if the patient does not initially appear to be at risk. Because approximately 2 million Americans have deep vein thrombosis every year (including otherwise healthy adults, the elderly, and persons with and without a history of venous insufficiency), prompt attention to symptoms is warranted. Diagnosis takes into consideration risk factors such as hypercoagulability, estrogen contraception, and Factor V Leiden mutation and is confirmed via compression ultrasonography and duplex ultrasound. Management includes anticoagulation therapy and thrombolytic therapy; prevention focuses on avoiding long periods of sitting, wearing compression hose when necessary and, for persons at risk, prophylactic anticoagulant therapy. Prescribed bedrest as a result of deep vein thrombosis provided one clinician/patient who did not consider herself to be at risk the opportunity to explore the condition in depth.     

Hyperhomocysteinemia in cerebral vein thrombosis

High plasma levels of total homocysteine (tHcy) are a risk factor for deep vein thrombosis. Because no information on the relationship between cerebral vein thrombosis and hyperhomocysteinemia is available, a case-control study of 121 patients with a first episode of cerebral vein thrombosis and 242 healthy control subjects was carried out. Fasting plasma levels of tHcy and their postmethionine load (PML) increments, together with other laboratory markers of thrombophilia, were measured in plasma or DNA. Hyperhomocysteinemia (high fasting tHcy and/or PML increments) was diagnosed in 33 patients (27%) and 20 control subjects (8%) (odds ratio, 4.2; 95% confidence interval [CI], 2.3-7.6). Low levels of serum folate and the 677TT methylene tetrahydrofolate reductase were associated with hyperhomocysteinemia, but in a multivariate model hyperhomocysteinemia only was associated with an increased risk of cerebral vein thrombosis. Oral contraceptive intake was associated with the disease with an odds ratio of 6.1 (95% CI, 3.3-11.0). The combined presence of the latter and hyperhomocysteinemia increased the risk of the disease with an odds ratio of 19.5 (95% CI, 5.7-67.3). In conclusion, hyperhomocysteinemia is associated with a 4-fold increased risk of cerebral vein thrombosis; whether or not its correction with vitamins reduces the risk of the disease remains to be demonstrated.     

Acute splanchnic vein thrombosis in patients with COVID-19: A systematic review

There is increasing evidence that coronavirus disease 2019 (COVID-19) is associated with a significant risk of venous thromboembolism. While information are mainly available for deep vein thrombosis of the lower limb and pulmonary embolism, scarce data exist regarding acute splanchnic vein thrombosis (SVT) in this setting. PubMed, EMBASE and Google Scholar English-language articles published up to 30 January 2021 on SVT in COVID-19 were searched. Overall, 21 articles reporting equal number of patients were identified. 15 subjects presented with portal vein thrombosis, 11 with mesenteric vein thrombosis, four with splenic vein thrombosis, and two with Budd-Chiari syndrome. Male sex was prevalent (15 patients), and median age was 43 years (range 26–79 years). Three patients had a history of liver disease, while no subject had known myeloproliferative syndrome. Clinical presentation included mainly gastrointestinal symptoms. Anticoagulation was started in 16 patients. Three patients underwent bowel resection. Ten subjects developed gastric or bowel ischemia, seven of whom underwent bowel resection, and four died after SVT diagnosis.Although rare, SVT should be seen as a complication of COVID-19. Patients with severe gastrointestinal symptoms should be screened for SVT, as rapid recognition and correct management are essential to improve the outcome of these patients.     

The LONFLIT4--Concorde Deep Venous Thrombosis and Edema Study: prevention with travel stockings

BACKGROUND: The LONFLIT1+2 studies have established that in high risk subjects after long flights (> 10 hours) the incidence of deep venous thrombosis (DVT) is between 4% and 6%. The LONFLIT4 study was designed to evaluate the control of edema and DVT in low-medium risk subjects. The aim of this study was to evaluate edema and its control with specific stockings (ankle pressure between 20 and 30 mm Hg) in long-haul flights. The first part of the study included flights lasting 7-8 hours and the second part included flights lasting 11-12 hours. Ultrasound scans were used to assess thrombosis before and after the flights and a composite edema score was used to evaluate edema and swelling. A group of patients with microangiopathy associated to edema (diabetes, venous hypertension, anti-hypertensive treatment) were also included to evaluate the preventive effects of stockings during flight. Part I: DVT evaluation: Of the 74 subjects in the stocking group and 76 in the control group (150), 144 completed the study. Dropouts were due to low compliance or traveling and connection problems. Age and gender distribution were comparable in the 3 groups as was risk factor distribution. In this part of the study there were no DVTs. Edema Evaluation: The level of edema at inclusion was comparable in the two groups of subjects. After the flight there was an average score of 6.9 (1) in the control group. In the stocking group, the score was on average 2.3 (1), three times lower than in the control group (p < 0.05). Part II: DVT evaluation: Of the 66 included subjects in the stocking group and 68 in the control group (134), 132 completed the study. Dropouts were due to low compliance or connection problems. Age and gender distribution were comparable in the two groups. In the stocking group no DVT was observed. In the control group, 2 subjects had a popliteal DVT and 2 subjects had superficial venous thrombosis (SVT); in total 4 subjects (6%) in the control group had a thrombotic event; the incidence of DVT was 3%. The difference (p < 0.02) is significant. EDEMA EVALUATION: The composite edema score at inclusion was comparable in the two groups. After the flight there was a score of 7.94 (2) in the control group, while in the treatment group the score was 3.3 (1.2). MICROANGIOPATHY STUDY: In all these subjects, the level of edema was very high in the control group and significantly lower in the compression stocking group. Stockings are effective in controlling edema during flights even in subjects with microangiopathy and edema. Compression was well tolerated in normal subjects and in patients. CONCLUSION: The Kendall Travel Socks (Tyco Healthcare, Mansfield, MA, USA) which provide 20-30 mm Hg pressure at the ankle, are effective in controlling edema and reducing the incidence of DVT in both low-medium-risk subjects and in patients with microangiopathy and edema in long-haul flights (7-11 hours).     

Hypercoagulability and hypofibrinolysis and risk of deep vein thrombosis and splanchnic vein thrombosis: similarities and differences

In this review, we provide an overview of the risk factors for venous thromboembolism, focusing on hypercoagulability and hypofibrinolysis. In the first part of this review, we discuss the risk factors for commonly occurring venous thrombosis, in particular deep vein thrombosis and pulmonary embolism. In the second part, we provide an overview of the risk factors for the Budd-Chiari syndrome and portal vein thrombosis. These are rare, life-threatening forms of venous thromboembolism located in the splanchnic veins. There are many similarities in the risk profiles of patients with common venous thrombosis and splanchnic vein thrombosis. Inherited thrombophilia and hypofibrinolysis increase the risk of both common venous thrombosis and splanchnic vein thrombosis. However, there are also apparent differences. Myeloproliferative neoplasms and paroxysmal nocturnal hemoglobinuria have a remarkably high frequency in patients with thrombosis at these unusual sites but are rarely seen in patients with common venous thrombosis. There are also clear differences in the underlying risk factors for Budd-Chiari syndrome and for portal vein thrombosis, suggesting site specificity of thrombosis even within the splanchnic venous system. These clear differences in underlying risk factors provide leads for further research on the site specificity of venous thrombosis and the development of thrombosis at these distinct sites.     

Long-haul flights and deep vein thrombosis: a significant risk only when additional factors are also present

To address the association between travel and deep vein thrombosis (DVT) we examined the risk factors for DVT in 568 consecutive patients with suspected DVT attending King's College Hospital in London. No significant link between DVT and long-haul travel was demonstrable in this cohort, with an odds ratio of 1.3 (CI 0.6-2.8). Risk of DVT was only increased in long-haul travellers if one or more additional risk factors were present, with an odds ratio of 3.0 (CI 1.1-8.2). Such individuals may benefit from prophylactic measures to minimize risk.     

Portal vein thrombosis in a patient with hyperhomocysteinemia

The authors present the case of a 18-year-old boy examined on account of accidentally detected splenomegaly and suspected venous convolute in the region of the porta hepatis. Coeliacography revealed cavernous reconstruction of the portal vein due to an old thrombosis and thrombosis of the lineal vein. At the time of assessment of this diagnosis the patient had no apparent risk factor for the development of venous thromboembolic disease. With regard to the serious character of the finding and the patients age later detailed haemocoagulation, biochemical and genetic examinations were made. The only risk factor for the development of thrombosis which was detected was medium severe hyperhomocysteinaemia (46.7 mumol/l) with C677T mutation in the gene for 5,10-methylene tetrahydrofolate reductase in the homozygous state. Although hyperhomocysteinaemia was identified already in the past as an important risk factor for the development of venous thromboembolic disease, in the available literature so far no case of portal vein thrombosis was described in a patient with hyperhomocysteinaemia as the only apparent risk factor.     

Portal venous thrombosis after umbilical vein catheterization.

PURPOSE: Portal vein thrombosis has been associated with umbilical venous catheterization. This prospective study was done to determine the incidence of neonatal portal venous thrombosis associated with catheterization of the umbilical vein . METHODS: Neonates who had undergone umbilical vein catheterization for exchange transfusion between March 2003 and March 2004 in Children's Hospital of Tabriz, Iran, were included. Doppler ultrasonography was performed within 1-2 weeks after the removal of the catheter. In the cases with portal venous thrombosis, subsequent serial ultrasonography was performed at intervals of every 1-2 months until clot resolution. Risk factors, if any were identified and correlated with catheter-related thrombi. RESULTS: Ultrasonography detected clinically silent portal venous thrombosis in 17 (34%) of 50 neonates. Follow-up ultrasonography was available in 13 of 17 babies, and revealed complete or partial resolution in all the cases. Sepsis was identified as a significant risk factor (p < 0.001). CONCLUSION: Umbilical venous catheter-associated thrombosis is common, and spontaneous resolution occurs in most cases.     

Combined liver vein and spleen pulp pressure measurements in patients with portal or splenic vein thrombosis

BACKGROUND: Patients with thrombosis of the portal or splenic vein may develop portal hypertension with bleeding from oesophageal or gastric varices. The relevant portal pressure cannot be measured by liver vein catheterization or transhepatic puncture of the portal vein because the obstruction is peripheral to the accessible part of the portal system. METHODS: Liver vein catheterization was combined with percutaneous splenic pressure measurement in 10 patients with portal or splenic vein thrombosis and no cirrhosis, and 10 cirrhotic patients without thrombosis. The splenic pressure was measured by percutaneous puncture below the curvature of the ribs with an angle of the needle to skin of 30 degrees in order to minimize the risk of cutting the spleen if the patient took a deep breath. RESULTS: None of the patients in whom the described procedure was followed had complications. Pressure measurements in the spleen pulp and splenic vein were concordant. The pressure gradient across the portal venous system (splenic-to-wedged hepatic vein pressure) was -1.3 to 8.5 mmHg (median, 2.8 mmHg) in cirrhosis patients and 0-44 mmHg (median, 18 mmHg) in thrombosis patients, the variation reflecting various degrees of obstruction to flow in the portal venous system. Peripheral portal pressure (splenic-to-free liver vein pressure gradient) was 1.1-28 mmHg (median, 17 mmHg) in cirrhotic patients and 11-52 mmHg (median, 23 mmHg) in thrombosis patients. CONCLUSIONS: Liver vein catheterization combined with percutaneous splenic pressure measurement is feasible in quantifying pressure gradient across a thrombosis of the portal/splenic vein and in quantifying portal pressure peripheral to this kind of thrombosis.     

Submassive pulmonary embolism and muscular calf vein thrombosis after complicated hip fracture

The clinical relevance of distal deep vein thrombosis is discussed controversly. A 26-year-old man presented with dyspnea on exertion and pleuritic pain since the day before. Five weeks ago, he sustained multiple fractures at an accident--among others a complicated hip fracture needing screw fixation. He stopped the antithrombotic prophylaxis three days before admission. Our examinations showed calf muscle vein thrombosis and submassive bilateral pulmonary embolism. Due to our own clinical experiences, we support an anticoagulation treatment with compression therapy for isolated calf muscle vein thrombosis in patients with coexisting risk factors for venous thromboembolism.     

Utilization of partition analysis to evaluate the incidence on deep vein thrombosis following esophagectomy

Background

We performed a retrospective observational study to examine the involvement of suspicious factors and causes of deep vein thrombosis using cases of esophagectomy that were done to treat esophageal carcinoma.

Methods

The 144 patients received esophagectomy in Okayama University Hospital from January 2005 to June 2007. All patients had an enhanced CT or an ultrasound examination after their operations. The incidence of deep vein thrombosis was then determined. For cases that found deep vein thrombosis, the anticoagulant treatment was strengthened. When the thrombosis was already so large to be seen in the inferior vena cava, the IVC filter was left to prevent a pulmonary embolism. Using JMP5.0.1 statistical analysis software, we analyzed the relationship between various clinical factors and the incidence of deep vein thrombosis.

Results

Using JMP5.0.1, factors causing deep vein thrombosis were analyzed and partitioning was done. The most significant risk factor causing deep vein thrombosis is leaving the central venous catheter inserted into the inguinal femoral area. Logistic analysis also showed that only the catheter if inserted from the inguinal femoral area, was significantly related to cause deep vein thrombosis (p < 0.0055). No other factor was a significant risk to cause deep vein thrombosis.

Conclusions

We analyzed the relationship between suspicious factors and the causes of deep vein thrombosis in cases of esophagectomy. The most relevant factors were inserting the central venous catheter from the inguinal femoral route. This evidence can be applied to both pre-operative and postoperative management to prevent deep vein thrombosis.     

Deep vein thrombosis and pulmonary embolism in two cohorts: the longitudinal investigation of thromboembolism etiology

PURPOSE: To determine the incidence of deep vein thrombosis and pulmonary embolism in two cohorts representing regions of the United States. METHODS: The sample comprised 21,680 participants of the Atherosclerosis Risk in Communities study and the Cardiovascular Health Study. Subjects were aged >/=45 years, resided in six communities, and were followed for 7.6 years. All hospitalizations were identified and thromboses were validated by chart review. RESULTS: The age-standardized incidence of first-time venous thromboembolism was 1.92 per 1000 person-years. Rates were higher in men than women, and increased with age in both sexes. There was no antecedent trauma, surgery, immobilization, or diagnosis of cancer for 48% (175/366) of events. The 28-day case-fatality rate was 11% (29/265) after a first venous thromboembolism and 25% (17/67) for cancer-associated thrombosis. The recurrence rate 2 years after a first venous thromboembolism was 7.7% per year (95% confidence interval [CI]: 4.5% to 10.9% per year). Cancer was the only factor independently associated with 28-day fatality (relative risk [RR] = 5.2; 95% CI: 1.4 to 19.9) or recurrent thrombosis (RR = 9.2; 95% CI: 2.0 to 41.7). CONCLUSION: The incidence of venous thromboembolism in this cohort of middle- and older-aged subjects was similar to that observed in more geographically homogeneous samples. Half of cases were idiopathic. Short-term mortality and 2-year recurrence rates were appreciable, especially among subjects with cancer. Based on this study we estimate that 187,000 cases of first-time venous thromboembolism are diagnosed yearly in the United States among those aged 45 years or older.