Incidence of and risk factors for childhood thrombosis: a single-center experience in Ankara, Turkey

Incidence and Management of Thromboembolism in Patients with Acute Leukemia

Thromboembolic events (TE) in childhood are relatively rare but, serious complications of acute leukemia. The aim was to define the incidence and risk factors of thrombosis in children with leukemias. The electronic files of pediatric denovo/relapsed acute leukemia patients aged below 18 years, treated between 2011 and 2021 were retrospectively evaluated for thrombotic attacks. Thirty out of 469 patients developed 35 thrombotic events. The median age at the time of the TE was 11.8 (2-17.6) years, and the median time from diagnosis to TE was 9 (0-58) months. The frequency of TE was found at 7.4% (n = 35/469). When catheter related (n = 13) events, superficial venous events (n = 10), and arterial central nervous system thrombosis (n = 1) were excluded, the frequency of TE was decreased to 2.3% (n = 11/469). Children older than 10 years old (13.8%; n = 21/152) had significantly higher thromboembolic events than the others (4.4%; n = 14/317) (p = 0.03). The majority of attacks were symptomatic 66% (n = 23/35). The most common complaints were local pain, swelling, and redness 52% (n = 12/23). The majority of attacks in patients with relapsed (75%; 6/8) and newly diagnosed acute lymphoblastic leukemia (40%; 10/25%) developed during the induction phase. Thrombosis recurred in 13.3% (n = 4/30) of cases more than once. Thrombotic attacks were successfully treated with low molecular weight heparin 60% (n = 21/35), and recombinant tissue plasminogen activator 17% (n = 6/35). None of the children were lost due to thrombosis. Thrombosis is an important complication during acute leukemia treatment. Successful results are obtained with early diagnosis and treatment attempts by creating awareness.

Association between polymorphism of MTHFR c.677C>T and risk of cardiovascular disease in Turkish population: a meta-analysis for 2.780 cases and 3.022 controls

Cardiovascular diseases (CVDs) remain the main cause of morbidity and mortality around the world. A common polymorphism c.677C>T has been identified in the gene coding for methylenetetrahydrofolate reductase (MTHFR), which is involved in the remethylation of homocysteine, and may predispose to CVDs. A meta-analysis was performed to estimate the risk of CVDs associated with MTHFR c.677C>T in Turkish population. Published studies were retrieved from PubMed, Science Citation Index/Expanded, Google Scholar, Turkish Medline, and the Turkish Council of Higher Education Theses Database. For each study, we calculated odds ratios and 95 % confidence intervals (CI), assuming frequency of allele and homozygote comparison, dominant and recessive genetic models. Thirty-one separate studies were included and 2.780 cases/3.022 controls were involved in the current meta-analysis. Significant association was found between c.677C>T polymorphism and risk of CVD when all studies pooled with random-effects model for T versus C (OR 1.33; 95 % CI 1.11-1.59; p = 0.002), TT vs. CC (OR 1.87; 95 % CI 1.35-2.60; p = 3.53E-04), TT+CT vs. CC (OR 1.32; 95 % CI 1.06-1.64; p = 0.014) and TT vs. CT+CC (OR 1.75; 95 % CI 1.29-2.37; p = 6.57E-04). Further analysis indicated the significant association between methylenetetrahydrofolate reductase (MTHFR) TT genotype and groups with venous thrombosis, peripheral arterial thrombosis, acute MI/MI. No publication bias was observed in any comparison model. Our results of meta-analysis suggest that MTHFR c.677C>T polymorphism is associated with the CVDs in Turkish population.

Femoral arterial thrombosis after cardiac catheterization in infancy: impact of Doppler ultrasound for diagnosis

Femoral arterial thrombosis (FAT) is a nonnegligible complication after cardiac catheterization (CC) in infancy. The aim of this study was to evaluate the impact of Doppler ultrasound (US) for diagnostic work-up after catheterization. We compared standard follow-up (FU) without Doppler US by relying on clinical signs of FAT with advanced FU using Doppler US of the femoral vessels. Between January and December 2009, we evaluated the rate of FAT in infants <12 months of age using a multicenter, prospective observational survey. We analysed 171 patients [mean age 4.1 ± 3.3 (SD) months; mean body weight 5.3 ± 1.8 kg] from 6 participating centres. The mean duration of catheter studies was 57.7 ± 38.0 min. The overall rate of FAT based on clinical diagnosis was 4.7% and was comparable in both groups [3.4% undergoing standard FU vs. 7.4% undergoing advanced FU (p = 0.15)]. However, the overall rate of thrombosis as screened by Doppler US was greater at 7.1 %, especially in patients after advanced FU [18.5% advanced vs. standard FU 1.7% (p < 0.01)]. In conclusion, FAT remains a relevant and underestimated complication after catheterization in young infants when relying only on clinical signs of FAT. Therefore, to start effective treatment as soon as possible, we recommend Doppler US to be performed the day after CC.

Pediatric intracardiac thrombus: a diagnostic and therapeutic dilemma

This case highlights the challenges in treating children with intracardiac thrombosis. We describe a teenager who developed an unsuspected de novo intracardiac thrombus. She was treated initially medically and surgically, but required subsequent surgery to treat a life-threatening recurrence. This case demonstrates an unusual presentation, as well as imaging, diagnostic, and therapeutic dilemmas. More significantly, it emphasizes the importance of a multidisciplinary approach for successful treatment of intracardiac thrombus.

Thromboembolism and venous thrombosis of the deep veins in surgical children--an increasing challenge?

Children share many known predisposing risk factors for venous thromboembolism and deep venous thrombosis but appears less common and is probably underestimated. Fatal pulmonary embolism is rare but may also be missed because of low level of clinical awareness. The aim of this study was to investigate children with thromboembolism of deep veins to evaluate risk factors and highlight their danger.

METHODS

This was a retrospective review of all children (<13 years old) diagnosed with a venous thromboembolism (1993-2009). Clinical and radiologic features and any risk factors were documented. Venous thromboembolism was diagnosed on clinical suspicion together with compressive Doppler studies, spiral computed tomography, or magnetic resonance scan.

RESULTS

Eighteen children with a consistent clinical picture were identified (painful unilateral limb swelling). Their mean age was 9.3 years with a male/female ratio of 3.5:1. Predisposing factors were identified in 17 (95%). These included infective conditions (n = 11), previous femoral line (n = 3), trauma (n = 2), and complicated appendicitis (n = 2). Chronic infective and inflammatory conditions included tuberculosis (n = 4), HIV (n = 3), staphylococcal septicemia (n = 2), and Takayasu arteritis (n = 1). Pulmonary embolism occurred in 5 (28%), and 1 presented later with a post-phlebitic leg. Elevated factor VIII was seen in 3.

CONCLUSION

This study identified an association with known risk factors in most children with venous thromboembolism and suggests that those with femoral venous access or ongoing chronic infective states (eg, TB/HIV) are particularly at risk.