Saphenous vein valve assessment utilizing upright CT to potentially improve graft assessment for bypass surgery.

Saphenous veins (SVs) are frequently employed as bypass grafts. The SV graft failure is predominantly seen at the valve site. Avoiding valves during vein harvest would help reduce graft failure. We endeavored to detect SV valves, tributaries, and vessel size employing upright computed tomography (CT) for the raw cadaver venous samples and in healthy volunteers. Five cadaver legs were scanned. Anatomical analysis showed 3.0 (IQR: 2.0-3.0) valves and 13.50 (IQR: 10.00-16.25) tributaries. The upright CT completely detected, compared to 2.0 (IQR: 1.5-2.5, p = 0.06) valves and 9.5 (IQR: 7.5-13.0, p = 0.13) tributaries by supine CT. From a total of 190 volunteers, 138 (men:75, women:63) were included. The number of valves from the SF junction to 35 cm were significantly higher in upright CT than in supine CT bilaterally [upright vs. supine, Right: 4 (IQR: 3-5) vs. 2 (IQR:1-2), p < 0.0001, Left: 4 (IQR: 3-5) vs. 2 (IQR: 1-2), p < 0.0001]. The number of tributaries and vessel areas per leg were also higher for upright compared with supine CT. Upright CT enables non-invasive detection of SV valves, tributaries, and vessel size. Although not tested here, it is expected that upright CT may potentially improve graft assessment for bypass surgery.

Backscattered Scanning Electron Microscopy Approach for Assessment of Microvessels under Conditions of Normal Microanatomy and Pathological Neovascularization.

We evaluated the efficiency of an original method for studying of the microvascular bed under conditions of normal microanatomy and pathological neovascularization. The blood vessels, tissues surrounding the stent in the pulmonary artery and subcutaneously implanted titanium nickelide plate, atherosclerotic plaque, and vascular stent with restenosis were examined. The specimens were fixed in formalin and stained in OsO4, embedded into fresh epoxy resin, grinded, polished, and counterstained with uranyl acetate and lead citrate. Numerous vasa vasorum were found in all native vessels. Around the pulmonary artery stent and metal plates, numerous newly formed vessels of small diameter were seen. The intensity of neovascularization in atherosclerosis and carotid stent restenosis differed significantly. Our technique can be successfully used for evaluation of the microvascular bed.

Assessment of posterior accessory great saphenous vein of the leg using ultrasonography: a preliminary study.

PURPOSE: To assess the frequency and anatomic distributions of the posterior accessory great saphenous vein of the leg (PAGSVL) and its insufficiency rate using ultrasonography (US) in patients who presented with clinical, etiologic, anatomic, and pathophysiologic (CEAP) scores of 1 and above. METHODS: A prospective US study on 200 limbs of 100 consecutive patients with CEAP scores of 1 and above. RESULTS: Right PAGSVL was seen in 45 % (45 cases), whereas left PAGSVL was seen in 54 % (54 cases) of the patients [49.5 % (99 limbs) in total] (p < 0.05). PAGSVL insufficiency was present in 6 % (6 cases) of the patients [6 limbs in total (6.06 %)]. The type of PAGSVL joining to the great saphenous vein (GSV) was above the knee level in 4 % (4 limbs), at the knee level in 14 % (14 limbs), and below the knee level in 74 % of patients (74 limbs). The relationship between posterior tibial perforators and PAGSVL was seen in 3.03 % of cases (3 limbs). There was no statistically significant relationship between PAGSVL insufficiency and the presence of posterior tibial perforators (p = 0.55) or between the presence of PAGSVL and the GSV insufficiency. CONCLUSION: PAGSVL was seen in half of the limbs with CEAP scores of 1 and above. The frequency of PAGSVL was more common in the left limbs than the right limbs. There was no statistically significant relationship between the presence of PAGSVL, GSV insufficiency, and different CEAP scores. The PAGSVL often joined to the GVS below the knee, but could also join above the knee.

Functional and morphologic assessment of saphenous veins harvested with minimally invasive techniques using a modified laryngoscope.

BACKGROUND: Minimally invasive saphenous vein harvesting techniques have been shown to reduce postoperative morbidity. Commercially available and often disposable instruments add significant costs to the operation. To lower expenses and to reduce postoperative morbidity, we used an ordinary laryngoscope fitted with a modified # 3 Heine blade for harvesting the greater saphenous vein for coronary artery bypass surgery. OBJECTIVE: To assess the integrity and function of the autologous, undistended, long saphenous vein harvested by a modified laryngoscope. METHODS: Morphology was examined by light and scanning electron microscopy. Endothelial function was assessed by vascular reactivity in an isolated organ bath. Veins, randomly taken and prepared traditionally, served as a control group. Contractile function was measured in response to potassium chloride. Endothelium-dependent relaxation was assessed by use of acetylcholine and calculated as percentage relaxation. RESULTS: There were no significant differences, in response to the constricting or dilating agent, in vein rings taken with the modified laryngoscope compared with the traditional 'open' technique (n = 10, p > 0.05 by ANOVA). Histologic examination by light and scanning electron microscopy showed no significant damage to the endothelial layer. CONCLUSION: Minimally invasive saphenous vein harvesting, using a modified laryngoscope yields morphologically and biologically intact veins.

An assessment of long saphenous venography to evaluate the saphenous vein for femoropopliteal bypass.

A long saphenous venogram was performed on a consecutive series of 42 patients (5 bilateral) though in 4 the vein was not satisfactorily demonstrated. In all cases the long saphenous vein was dissected out and its suitability for use for a femoropopliteal bypass compared to the radiological findings. Eleven veins were unusable for a bypass and radiologically these were narrower (mean diameter 2.8 mm) than the veins which functioned satisfactorily (mean diameter 5.0 mm), and had more tributaries (mean 5) than the suitable veins (mean 2). Preoperative venography is a useful technique to identify veins that will be unsuitable for a femoropopliteal bypass and thereby save an unnecessary dissection.

The radiologic assessment of vessel wall thickness.

A method allowing accurate and repeated measurements of vessel wall thickness has been developed. It consists of permanent opacification of the outer wall with tantalum in conjunction with magnification angiography. The technique was tested in a model, in human saphenous vein specimens, and in long-term experiments in rabbit blood vessels. Eighteen rabbits underwent exploratory surgery, after which the abdominal aorta, inferior vena cave, and the femoral and carotid arteries were coated with tantalum paste. Subsequently, magnification angiograms were performed from one to 14 months later. The wall thickness ranging between 100 and 300 micron was clearly visualized. While no gross inflammatory or foreign body reaction was seen, small granulomata adjacent to the blood vessels were frequently identified. The method described can be valuable in studying the natural history of the atherosclerotic process, particularly the behavior of vascular grafts.