A histological and functional description of the tissue causing chronic postthrombotic venous obstruction.

BACKGROUND: Postthrombotic intraluminal tissue causing postthrombotic syndrome (PTS) has not been well described. This study defines its histological characteristics and assess whether tissue function evolves over time. METHODS: Specimens from 18 common femoral veins (CFV) from 16 patients obtained during CFV endovenectomy and iliocaval recanalization were examined. Phase 1 used hematoxylin and eosin and Masson's trichrome stains for collagen, immunohistochemical, and Von Kossa stains. Phase 2 examined young (≤ one year) and mature (≥10years from acute DVT) specimens to evaluate evolution of endothelial function. Antibodies to four biomarkers were used to examine specific functions of endothelial cells lining neovessels and recanalization channels (RC). RESULTS: Phase 1: Specimens demonstrated 80-90% of collagen type I, 10-20% of collagen type III, and dystrophic calcification. Neovessels and RC were in close proximity to each other. Thrombus and smooth muscle cells were absent, but white blood cells were present. Phase 2: VEGFR2 receptor uptake was more abundant in neovessels than RC and more prominent in younger specimens. Neovascular, nonchannel cells were observed more frequently in young specimens. CD-31 was similar in young and mature specimens. TIE-2 and von Willebrand factor antibodies had greater uptake in mature specimens. CONCLUSION: Tissue causing chronic postthrombotic venous obstruction is predominantly type I collagen. Neovascularization and recanalization occur in close proximity. The biomarker for neovascularization and angiogenesis (VEGFR2) was more prominent in young specimens whereas TIE-2, a stabilizing biomarker and vWF were more frequently observed in mature specimens.

Aortic mural thrombus in the normal or minimally atherosclerotic aorta.

BACKGROUND: Aortic mural thrombus in a nonaneurysmal minimally atherosclerotic or normal aorta is a rare clinical entity and an uncommon cause of peripheral arterial embolization. Both anticoagulation therapy and aortic surgery are commonly used as primary treatment, but there are no consensuses or clinical guidelines to outline the best management strategy for this unusual problem. This systematic review compares the outcomes of these different strategies for the treatment of aortic mural thrombus. METHODS: An extensive search of the literature was conducted, and all relevant publications were reviewed, with individual patient data pooled in this meta-analysis. The outcome variables included were persistence or recurrence of aortic thrombus, recurrence of peripheral embolization, mortality, and a composite end point of complications consisting of stroke, limb loss, and bowel resection. Chi-square test and logistic regression analysis were used to compare groups and to find any predictors of adverse outcome. RESULTS: Two hundred patients from 98 articles were considered. Of these, 112 patients received anticoagulation and 88 underwent aortic surgery as primary treatment. Smoking was more prevalent in the surgery group, but no other significant differences in demographics, comorbidities, or mode of presentation were seen between groups. The surgery group was more likely to have aortic thrombus located in the arch, but there were no differences in terms of the mobility or size of the thrombus between groups. Aortic thrombus persisted or recurred in 26.4% of the anticoagulation group and in 5.7% of the surgery group (P < 0.001). Recurrence of peripheral arterial embolization was seen in 25.7% of the anticoagulation group and 9.1% of the surgery group (P = 0.003). Mortality rates were similar at 6.2% and 5.7% for the anticoagulation group and the surgery group, respectively (P = 0.879). Complications were noted in 27% of the anticoagulation group and 17% of the surgery group (P = 0.07), and major limb amputation rates were 9% for the anticoagulation group and 2% for the surgery group (P = 0.004). Logistic regression analysis established thrombus location in the ascending aorta (odds ratio [OR]: 12.7; 95% confidence interval [CI]: 2.3-238.8) or arch (OR: 18.3; 95% CI: 2.6-376.7), mild atherosclerosis of the aortic wall (OR: 2.5; 95% CI: 1-6.4), and stroke presentation (OR: 11.8; 95% CI: 3.3-49.5) as important predictors of recurrence. CONCLUSIONS: The results of our meta-analysis seem to favor the surgical management of aortic mural thrombus in the normal or minimally diseased aorta. Anticoagulation as primary therapy is associated with a higher likelihood of recurrence, a trend toward a higher incidence of complications, and a higher incidence of limb loss. Aortic surgery should be considered as primary treatment, particularly for those patients at high risk for recurrence considered to be good operative candidates.