Depiction of the vasa vasorum during carotid endarterectomy by intraoperative videoangiography.

BACKGROUND: The aim of the study was to investigate the depiction of the carotid artery by fluorescein sodium (FS) videoangiography compared with indocyanine green (ICG) videoangiography, focusing on how the vasa vasorum of the carotid artery is depicted. METHODS: Thirty-five patients (19 FS patients, 16 ICG patients, mean age 69.4 ± 5.1 years, mean degree of stenosis 78.7% ± 11.7%) who underwent a carotid endarterectomy (CEA) were enrolled. FS (5-6 mg/kg) or ICG (.2-.3 mg/kg) was injected intravenously as a bolus before the arterectomy during the CEA. The intravascular fluorescence signal was recorded with a digital video camera integrated on a microscope. Magnetic resonance imaging black-blood (BB) T1-weighted imaging (WI) was preoperatively performed using a 1.5-T whole-body imager, and the signal intensity ratio relative to the ipsilateral sternocleidomastoid muscle on BB-T1WI (BB-SIR) was calculated. We also performed an immunohistochemistry study using CD31 and CD68 antibodies for plaque specimens. RESULTS: In the FS videoangiography series, the vasa vasorum of carotid adventitia was depicted first, followed by augmentation of FS of the wall and partially the inner lumen (pattern A) in 6 cases. Augmentation of FS of the wall and inner lumen prior or simultaneous to the depiction of the vasa vasorum of the carotid adventitia (pattern B) were observed in 13 cases. The average BB-SIR value of the pattern B cases was significantly higher than that in the pattern A group (P < .05). Most of the plaques with BB-SIR values higher than 1.25 also belonged to the pattern B group (90.9%). Microvessels stained by CD31 and macrophages stained by CD68 were more frequently observed in the high-BB-SIR plaques. In contrast, the ICG videoangiography uniformly showed pattern B in all 16 cases, because of the fluorolucency of the carotid wall revealed by the ICG. CONCLUSIONS: The early depiction of adventitial vasa vasorum in FS videoangiography was inversely associated with the BB-SIR values of the plaques, along with many microvessels and macrophages that have been reported to have a tendency of intraplaque hemorrhage or symptoms. The present results may support the idea of an intimal origin of the neovascularization in vulnerable carotid plaques, and they demonstrated the potential of intraoperative plaque imaging by FS videoangiography.

Quantitative analysis of carotid plaque vasa vasorum by CEUS and correlation with histology after endarterectomy.

BACKGROUND: Intraplaque neovascularization and vasa vasorum (VV) proliferation contribute in the progression and rupture of atherosclerotic lesions. Contrast enhanced ultrasonography (CEUS) has been reported to attain data regarding intraplaque neovessels and VV. However, whether the detection of microbubbles by CEUS within atherosclerotic plaques truly represents microvessels is a point of concern. We aimed to evaluate stable and unstable carotid artery plaque (CAP) VV pattern by CEUS and its correlation with histology and immunochemistry. PATIENTS AND METHODS: Patients with CAP scheduled for plaque endarterectomy were enrolled. CAP was initially identified by conventional ultrasonography and subsequently CEUS (harmonic ultrasound imaging with simultaneous intravenous contrast agent injection) was performed. The recorded image loops were evaluated by a semi-automated method. Plaque specimens were excised and underwent histological and immunochemical (for CD34, Vascular Endothelial Growth Factor, CD68 and CD3 antibodies) analysis. RESULTS: Fourteen patients (67.6 ± 10.2 years, 10 males) with a 86.9 ± 11.5 % degree of carotid artery stenosis were evaluated. Histology showed that half of the plaques were unstable. Enhancement of plaque brightness on CEUS was significant for both stable and unstable plaque subgroups (p = 0.018 for both). Immunochemistry showed that microvessels, as assessed by CD34 antibody, were more dense in unstable vs. stable plaques (36.6 ± 17.4 vs. 13.0 ± 7.2 respectively, p = 0.002). However, correlation between plaque brigthness enhancement on CEUS and microvessel density was significant only for stable (r = 0.800, p = 0.031) plaques. CONCLUSIONS: The identification of brightness enhacement during CEUS in carotid atherosclerotic plaques may not always reflect the presence of VV.

Vagina vasorum dissection during D2 lymphadenectomy for gastric carcinoma.

AIM: To explore the relationship between metastasis and vagina vasorum in the progress of gastric carcinoma and to find some facts and references for gastric surgeons. METHODS: One hundred and seven specimens of left or right gastric arteries (55 left and 52 right) were gathered from 59 patients undergoing radical gastrectomy for gastric carcinoma. All the frozen specimens were cut into 3 microm-thick sections and stained with hematoxylin-eosin (HE) and immunohistochemical method separately. Cytokeratin (CK) and mesothelial cells (MC) were stained with immunohistochemical method. Cancer cells inside vagina vasorum were detected and the structure of artery wall was observed under microscope. RESULTS: Metastatic cancer cells or tubercles were found inside vagina vasorum in some stage III or IV specimens, but not in stage I or II specimens. Tumor cells in vagina vasorum were CK positive in 26 specimens of 14 tumors. Among them, stage III was found in 4 specimens of 2 tumors, and stage IV in 22 specimens of 12 tumors. None of these specimens was positive for MC. The positive rate of CK increased with TNM staging. Compared with the lower part, tumors in the upper and middle parts of stomach were more likely to metastasize into vagina vasorum. CONCLUSION: Vagina vasorum dissection should be performed during D2 lymphadenectomy for TNM stage III or IV gastric carcinoma.

Uncommon presentation of Behçet's syndrome: aortic aneurysm and dissection due to Behçet's syndrome.

Aneurysm and dissections localized to the ascending aorta are usually encountered in patients with atherosclerosis and hypertension. Behçet's syndrome is a rare vasculitic syndrome occasionally responsible for inflammation in small to large vessels. Aneurysm formation and dissection in the ascending aorta due to Behcet's disease is an even rarer presentation of this vasculitis that will be discussed in conjunction with a case presentation.

Bypass surgery for occluded internal carotid artery revascularized by vasa vasorum--case report.

A 47-year-old woman presented with two transient ischemic attacks due to occlusion of the left internal carotid artery. The affected artery was revascularized by vasa vasorum. Angiography showed occlusion of the left common carotid artery including the origin of the internal carotid artery. The distal internal carotid artery was revascularized by vasa vasorum at the level of the second cervical vertebral body. Left subclavian artery-internal carotid artery bypass surgery using a saphenous vein graft was performed successfully, during which the narrowed but patent lumen of the internal carotid artery was confirmed. Follow-up angiography showed enlargement of the left internal carotid artery distal to the patent bypass. Reconstructive bypass surgery is a possible treatment for patients with occluded internal carotid artery revascularized by vasa vasorum. Angiographic detection of the lumen of the internal carotid artery is important for surgical consideration.

Medial necrosis and acute alterations in aortic distensibility following removal of the vasa vasorum of canine ascending aorta.

OBJECTIVE: It is known that the outer layers of the thoracic aorta receive substantial blood flow through vasa vasorum. This study was undertaken to test the hypothesis that removal of vasa vasorum flow will alter the elastic properties of the ascending aorta. METHODS: Distensibility of the ascending aorta was determined before and 30 min after careful removal of the periaortic fat network which contains the vasa vasorum in 10 acutely instrumented dogs (experimental group) and the results were compared with those obtained from six weight matched sham operated control dogs. Aortic distensibility was measured using the formula: distensibility = 2 x pulsatile changes in aortic diameter divided by (diastolic aortic diameter x pulse pressure). Aortic pressures were measured directly from the ascending aorta by a pressure gauge. Aortic diameters were simultaneously determined by an elastic air filled ring connected to a transducer. The efficacy of the technique for the interruption of vasa vasorum blood supply to the aortic wall was proved in six additional animals by histology of transverse blocks of aortic wall from the area of interest. Histology was performed before vasa vasorum removal in two animals, 30 min after vasa vasorum removal in another two, and 15 d after vasa vasorum removal in the remainder. RESULTS: At baseline, there was no difference in the measured variables between the two groups. Aortic distensibility decreased significantly in the experimental group after vasa vasorum removal by 0.90(SEM 0.17) 10(-6).cm2.dyn-1 (p < 0.001), while it remained unchanged in the control group during the experiment. Complete removal of vasa vasorum of the ascending aorta was found in experimental group animals which were killed 30 min after operation, while ischaemic medial necrosis was observed in those killed 15 d after operation. CONCLUSIONS: Vasa vasorum removal led to an acute decrease in the distensibility of the ascending aorta. Lack of blood supply to the outer part of the aortic wall is most likely to have accounted for these findings.

Early changes in dissected small vessels: experimental study on rat arteries and veins.

This study was undertaken to investigate the cause of the early endothelial damage that is seen at sites of microvascular anastomosis and in particular to study the possibility of a connection between damage to the vasa vasorum and subsequent endothelial denudation. Rat femoral vessels were subjected to a variety of experimental injuries, including simple dissection, clamping, and ligation. The vessels were examined in longitudinal section by light microscopy at intervals ranging from 5 minutes to 1 day. The endothelial cells were counted and the numbers were analyzed statistically. In addition, the anatomy of the vasa vasorum was studied using india ink perfusion. Simple dissection of the femoral vessels and excision of the vasa vasorum without interruption of blood flow were followed by ischemic lesions of the tunica media with subendothelial edema and ballooning and exfoliation of endothelial cells. Endothelial denudation reached a maximum level in 30 minutes. Adherence of leukocytes was found on damaged endothelial cells. Mural thrombi were seen in 13.6 percent of arteries and in 40 percent of veins following simple dissection.

Vein to artery grafts. A quantitative study of revascularization by vasa vasorum and its relationship to intimal hyperplasia.

Iliolumbar vein to iliac artery grafts were placed in 40 rats by microsurgical technique. Groups of animals were perfused with fixative at eight intervals between one and 20 weeks after operation, and sections of the graft and control arteries (the opposite iliacs) were analyzed microscopically. The revascularization of the graft by capillaries commenced within the first postoperative week. The level of vascularity (capillaries per cross-sectional mm2) increased during the first four weeks, maintained a constant level and declined after week 16. The grafts of the 17--20 week group were substantially less vascular than the earlier groups. Intimal thickening commenced at three to four weeks after operation, i.e. during the period of increasing graft vascularity. The mean intimal proportion of the graft was 14% at four to five weeks and at 17--20 weeks was 35% of the cross-sectional area of the graft wall. However, the actual thickness of the intima did not increase significantly with time, rather the whole graft wall tended to become thinner. At 17--20 weeks grafts which showed a high degree of intimal thickening had significantly fewer capillaries within their walls. Quantitative evidence is presented to suggest that the continued growth of the graft intima may not be supported by a similar increase in the number of vasa vasorum. Therefore, it is suggested that the reduced level of vascularity in grafts with hyperplastic intimae may form an ischemic basis for degenerative changes which are known to take place in some long-term grafts.

Lymphaticolymphatic anastomosis.

Lymphaticovenous anastomosis has proved valuable in the treatment of obstructive lymphedema. Histological studies of this anastomosis have shown the lymphatic component to be almost inactive in anastomotic healing. In order to clarify the role of the lymphatics, experimental lymphaticolymphatic anastomoses were performed in canine femoral lymphatics. The technique developed calls for eight to ten 19 mu sutures to prevent vessel wall collapse, and preservation of the vasa vasorum. Vessels were harvested from one hour to six weeks after anastomosis. Scanning electron microscopy and conventional light histology revealed the lymphatics to have active healing of the intima with complete reendothelialization by two weeks. The techniques developed in this study are directly applicable to human lymphaticovenous anastomosis.