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At least 577 records · Page 32Linked to original sources
PubMed2006

Indicators of the maximum radiation dose to the skin during percutaneous coronary intervention in different target vessels.

OBJECTIVES: To evaluate whether the maximum radiation dose to the patient's skin (MSD) can be estimated during percutaneous coronary intervention (PCI) procedures, we investigated the relationship between the MSD and fluoroscopic time, dose-area product (DAP), and body weight, separately analyzing the relationships for different target vessels. BACKGROUND: Many cases of skin injury caused by excessive radiation exposure during cardiac intervention procedures have been reported. However, real-time maximum-dose monitoring of the skin is unavailable for many cardiac intervention procedures. METHODS: We studied 197 consecutive PCI procedures that involved a single target vessel and were conducted. The DAP was measured, and the MSD was calculated by a skin-dose mapping software program (Caregraph). The target vessels of the PCI procedures were divided into four groups based on the AHA classification system: AHA 5-10, left anterior descending artery domain (LAD), AHA 11-15, left circumflex artery domain (LCx), AHA 1-3 = R 1-3, and AHA 4 = R 4. RESULTS: The correlation coefficient (r) between the MSD and fluoroscopic time was higher for the right coronary artery (RCA) vessels (R 1-3, 0.852; R 4, 0.715) than for the left coronary artery (LCA) vessels (LAD, 0.527; LCx, 0.646), and the r value between the MSD and DAP was higher for the RCA vessels (R 1-3, 0.871; R 4, 0.898) than for the LCA vessels (LAD, 0.628; LCx, 0.694). Similarly, the correlation coefficient between the MSD and weight x fluoroscopic time (WFP) was higher for the RCA vessels (R 1-3, 0.874; R 4, 0.807) than for the LCA vessels (LAD, 0.551; LCx, 0.735). CONCLUSIONS: The DAP and WFP can be used to estimate the MSD during PCI in the RCA but not in the LCA, especially the LAD.

Adult↗
PubMed2002

Vascular response to laser photothermolysis as a function of pulse duration, vessel type, and diameter: implications for port wine stain laser therapy.

BACKGROUND AND OBJECTIVE: Treatment of port wine stains (PWS) by photothermolysis can be improved by optimizing laser parameters on an individual patient basis. We have studied the critical role of pulse duration (t(p)) on the treatment efficacy. STUDY DESIGN/MATERIALS AND METHODS: The V-beam laser (Candela) allowed changing t(p) over user-specified discrete values between 1.5 and 40 milliseconds by delivering a series of 100 microsecond spikes. For the 1.5 and 3 millisecond pulses, three spikes were observed at intervals t(p)/2 and for t(p)> or =6 milliseconds, four spikes separated by t(p)/3. The ScleroPlus laser (Candela) has a smooth output over its fixed 1.5 milliseconds duration. Blood vessels in the chick chorioallantoic membrane (CAM) were irradiated at fixed wavelength (595 nm), spot size (7 mm), radiant exposure (15 Jcm(-2)), and at variable t(p). The CAM contains an extensive microvascular network ranging from capillaries with diameter D<30 microm to blood vessels of D approximately 120 microm. The CAM assay allows real-time video documentation, and observation of blood flow in pre-capillary arterioles (A) and post-capillary venules (V). Vessel injury was graded from recorded videotapes. Mathematical modeling was developed to interpret results of vessel injury when varying t(p) and D. A modified thermal relaxation time was introduced to calculate vessel wall temperature following laser exposure. RESULTS: Arterioles. For increasing t(p), overall damage was found to decrease. For fixed t(p), damage decreased with vessel size. Venules. For all D, damage was smaller than for corresponding arterioles. There was no dependence of damage on t(p). For given t(p), no variation of damage with D was observed. Photothermolysis due to spiked (V-beam) vs. smooth (Scleroplus) delivery of laser energy at fixed t(p) (1.5 milliseconds), showed similar vessel injuries for al values of D (P>0.05). CONCLUSIONS: The difference between initial arteriole and venule damage could be explained by the threefold higher absorption coefficient at 595 nm in (oxygen-poor!) arterioles. In human patients, PWS consist of ectatic venules (characterized by higher absorption), so that these considerations favor the use of 595-nm irradiation for laser photothermolysis. For optimal treatment of PWS it is proposed that t(p) be between 0.1 and 1.5 milliseconds. This is based on a modified relaxation time tau'(d), defined as the time required for heat conduction into the full thickness of the vessel wall, which is assumed to have a thickness DeltaD approximately 0.1D. The corresponding tau'(d) will be a factor of about six smaller than given in the literature. For vessels with D between 30 and 300 mum, tau'(d) ranges from 0.1 to 1.5 milliseconds.

Humans↗
PubMed2006

Magnetic resonance angiography of collateral vessel growth in a rabbit femoral artery ligation model.

Collateral vessel growth was visualized in a rabbit femoral artery ligation model by serial contrast-enhanced magnetic resonance angiography (MRA) at 1.5 T in comparison with X-ray angiography (XRA). XRA and MRA were performed directly after femoral artery ligation (day 0+) and after 7 and 21 days. XRA (in-plane resolution, 0.3x0.3 mm) was performed with arterial catheterization for fast injection of iodinated contrast agent just proximal to the aortic bifurcation. MRA (in-plane, 0.6x0.6 mm) was performed at 1.5 T with a five-element phased-array coil and slow injection of gadolinium-based MR contrast agent into an ear vein. Collateral vessel scores on two-dimensional XRA projections and on three-dimensional digitally subtracted rotational MRA maximum intensity projections were obtained by two observers and compared. Collateral vessel counts and minimal detectable vessel diameters for MRA and XRA were combined in a computational flow model to interpret differences in spatial detection limits between imaging modalities in terms of flow. Collateral vessel scores were significantly higher in the ligated limb at day 7 (P < 0.05) and more so at day 21 (P < 0.001), in comparison with day 0+ or in the non-ligated control limb on both XRA and MRA. Significantly more (smaller) vessels were visualized with XRA than with MRA, particularly on day 21 (P < 0.05). Inter-observer agreement was high for both XRA (kappa = 0.82) and MRA (kappa = 0.78). The flow model showed that collateral vessels with diameters > 0.3 mm scored by XRA as well as MRA represent nearly 100% of the total blood flow, whereas smaller (0.1-0.3 mm diameter) vessels that can only be detected with XRA contribute little to the blood flow. Serial contrast-enhanced MRA can non-invasively visualize sub-millimeter collateral vessels that represent nearly 100% of the restored blood flow, in a femoral artery ligation model.

Animals↗
PubMed1988

Oxygen reaction vessels.

Transcutaneous oxygen electrodes were modified to be more suitable as a component of oxygen reaction vessels. The temperature control system was removed from the transcutaneous electrode to decrease the thickness and improve the stability. The temperature control system was incorporated in the metal sleeve surrounding the glass reaction vessel to shorten the distance between the magnetic stirrer and stirring bar, enabling smooth stirring with a short magnetic bar. With these modifications, we have succeeded in reducing the vessel volume to about 0.5 ml, or two to four times smaller than reaction vessels incorporating unmodified transcutaneous electrodes (vessel volume = 1-2 ml) and about twenty times smaller than reaction vessels using rod-shaped Clark electrodes (vessel volume about 10 ml). In another vessels modified as above, two optical guides were connected to the metal sleeve for irradiating the solution and receiving transmitted light simultaneously to enable simultaneous measurements of oxygen concentration absorption spectra. The relationship between oxygen concentration and absorption spectra of Hb is described as an application of this vessel.

Electrodes↗
PubMed1980

Unusual blood vessels in the cochlea of the squirrel monkey.

Unusual blood vessels in the cochlea of the squirrel monkey are reported. The blood vessels in Reissner's membrane and basilar membrane are occasionally found in the course of the experimental middle ear study. The blood vessel of Reissner's membrane derives from a radiating arteriole in the upper spiral ligament and takes a straight course down to the inner surface of the spiral limbus, running on the scala vestibuli side of Reissner's membrane, and finally joins the venous vessel of the spiral limbus. Two blood vessels are noted in the basilar membrane of basal turn, running fairly parallel to each other from the tympanic lip to the basilar crest of the spiral ligament in the same cochlea. It is confirmed that these unusual blood vessels derive from the radiating arterioles in the osseous spiral lamina and connect with the venules of the basilar crest in the spiral ligament. Although unusual blood vessels in both Reissner's membrane and basilar membrane are thought to be vestigial structures, they contain a remarkable amount of alkaline phosphatase in their walls. This suggests that these unusual vessels have actually functioned until their death. Multiple occurrence of unusual blood vessels in both Reissner's membrane and basilar membrane of the cochlea of various animals, including man, has not yet been reported in the literature as far as we have been able to ascertain. Incomplete devascularization in the developing process of the cochlea may possibly be the cause of such unusual conditions after birth.

Animals↗
PubMed2001

[Imaging the smallest tumor vessels using color Doppler ultrasound in an experiment].

PURPOSE: We present an experimental, statistical approach to estimate the size required for small vessels to become detectable with color Doppler sonography. MATERIALS AND METHODS: A murine experimental tumor was examined with color Doppler sonography after injection of 1.5 ml of the contrast medium Levovist. Histologically, we measured vessel diameters inside the tumor as well as other, clearly identifiable locations. RESULTS: With color Doppler at a transmit frequency of 7 MHz, vessels were only detected in the tumor's environment, but not inside. From the 95% quantiles of the vessel diameter distribution found histologically, we estimate that vessels 80-140 microns in diameter or above may be detectable with color Doppler sonography, while vessels 40 microns in diameter or smaller are indetectable. CONCLUSIONS: Although a direct sonographic--histologic correlation is impossible for small vessels, a systematic assessment of the size distribution in clearly identifiable regions permits to estimate the sensitivity of color Doppler to detect blood flow in small vessels. According to our results, capillary blood flow is indetectable, and precapillary vessels may be detected only under optimal conditions.

Animals↗
PubMedDate not supplied

Neoplasms containing normal hepatic vessels: imaging features.

BACKGROUND: We investigated the incidence and imaging features of hepatic neoplasms containing normal hepatic vessels. METHODS: Among 3183 patients with various hepatic neoplasms, we found nine patients with normal hepatic vessels traversing hepatic neoplasms. The presence of mass effect on the vessel traversing hepatic neoplasms was evaluated. Other suggestive findings of neoplasms such as altered hepatic contour, portal vein thrombosis, mass effect on extratumoral vessel, and bile duct dilatation were analyzed. RESULTS: Thirteen hepatic vessels (nine hepatic veins and four portal veins) extended through hepatic neoplasms in nine patients. Undisturbed hepatic vessels within the neoplasms were found in five patients with either primary or metastatic hepatic neoplasm. In one patient with undisturbed hepatic vessels within the neoplasm, there were no associated abnormal findings such as biliary dilatation, change of hepatic contour, or any changes involving the vessels external to neoplasms. CONCLUSION: Although rare, various primary and secondary hepatic neoplasms can have normal hepatic vessels passing through them without mass effect. However, correct diagnosis in most neoplasms would be possible with careful examination of associated findings.

Adolescent↗
PubMed1999

Increase of segments of elastic-type blood vessel walls in fetal placental stem villi during pre-eclampsia at term.

In recent studies we described the presence of elastic-type blood vessels within trunci and rami chorii of human placental stem villi. For systemic and pulmonary hypertension it is known that elastic fibres are enhanced in arteries. The aim of our study was, therefore, to examine whether pre-eclampsia may lead to an increase of elastic tissue fibres in blood vessel walls of placental stem villi and whether there are differences in the thickness of blood vessel walls within these villi when compared to normotensive pregnant women. Twenty-six women with uncomplicated pregnancies and 25 patients with pre-eclampsia were investigated. Unfixed cryostat serial sections were processed for conventional orcein staining and for the demonstration of alpha-actin-immunoreactivity. The intensity of orcein staining of stem villus blood vessel walls was evaluated by a semiquantitative score method. Significant higher intensities of orcein staining (P<0.00001) were calculated for blood vessel walls of placentae with pre-eclampsia. The amount of thick stem villus vessels (>41 microm) increased during pre-eclampsia from 39 gestational weeks onwards. Our study demonstrates that segments of thick blood vessel walls and elastic-type vessel walls are increased in placental stem villi of patients with pre-eclampsia. This reaction may protect the fetal placental vessels and avert an increase of the fetal hypertension.

Chorionic Villi↗
PubMed1987

Effects of dihydropyridines on tension and calcium-45 influx in isolated mesenteric resistance vessels from spontaneously hypertensive and normotensive rats.

Contractile tension responses to norepinephrine and depolarizing potassium (80 mM K+), as well as calcium-45 influx stimulated by these agents, were studied in isolated mesenteric resistance vessels (each 100 microM internal diameter) from spontaneously hypertensive rats (SHRs) and from normotensive Wistar Kyoto rats (WKYs). Inhibitory effects of 2 dihydropyridine Ca++ antagonists, PN 200-110 (isradipine) and nisoldipine, on these parameters were also determined. Contractile responses to 80 mM K+ were inhibited by both Ca++ antagonists with the same potency and efficacy in SHR compared with WKY vessels (PN 200-110 IC50 = 2.8 +/- 1.3 X 10(-8) M in SHRs and 2.5 +/- 1.5 X 10(-8) M in WKYs; nisoldipine IC50 = 1.1 +/- 0.4 X 10(-8) M in SHRs and 1.2 +/- 0.9 X 10(-8) M in WKYs). However, contractile responses to norepinephrine (10(-4) M) were inhibited less potently by nisoldipine in SHR vessels (IC50 = 2.2 +/- 0.3 X 10(-9) M) compared with WKY vessels (IC50 = 1.6 +/- 0.6 X 10(-10) M). Similarly, PN 200-110 tended to be less (but not significantly less) potent in SHR vessels (IC50 = 3.3 +/- 1.8 X 10(-8) M) than in WKY vessels (IC50 = 3.4 +/- 0.9 X 10(-9) M); its efficacy was significantly depressed in the SHR vessels (by approximately 20%). When norepinephrine-stimulated calcium-45 influx was determined in the presence of these Ca++ antagonists, a similar profile emerged with respect to a comparison of SHR and WKY vessels. These results support a previously hypothesized alteration in receptor-activated Ca++ influx pathways in SHR mesenteric resistance vessels.

Animals↗
PubMed1986

Nature of the bleeding vessel in recurrently bleeding gastric ulcers.

An unselected consecutive series of 826 patients admitted for acute upper gastrointestinal bleeding underwent urgent endoscopy. Peptic ulcers were found in 402 (49%). Of the 329 ulcer craters that could be fully examined, visible vessels were identified in 156 (47%), other stigmata of recent hemorrhage in 66, and no stigmata of recent hemorrhage in 107. One hundred twenty-nine patients with stigmata of recent hemorrhage (93 of whom had visible vessels) randomly allocated to no endoscopic treatment were observed for evidence of further bleeding. Fifty-four of the 93 patients (58%) with visible vessels rebled, compared with 2 of 36 (6%) with other stigmata of recent hemorrhage. No patient without stigmata of recent hemorrhage rebled. Twenty-seven patients in whom a visible vessel in a gastric ulcer was identified at endoscopy underwent urgent partial gastrectomy because of recurrent bleeding. The vessel identified at endoscopy was found in 26 of 27 resection specimens (96%). The arterial vessel wall protruded above the surface of the ulcer crater in 10 specimens, and clot in continuity with a breach in the vessel wall protruded in a further 10 specimens. Postoperative angiography, when technically possible, showed that the breached artery ran across the base of the ulcer in all of these specimens. Pathological changes were common in the bleeding artery and included arteritis in 24 of 29 (83%) eroded arteries found in these specimens, with aneurysmal dilatation in 14 of 27 (52%) bleeding points that could be fully examined. The ulcer had penetrated to serosa in 13 specimens (45%). The bleeding artery had a mean external diameter of 0.7 mm with a range of 0.1-1.8 mm. This study provides new information about the nature of the bleeding vessel in gastric ulcers, and some of this information is relevant in planning studies of endoscopic therapy for bleeding peptic ulcers. It validates the endoscopic identification of a visible vessel, and confirms that such identification has a high predictive value for the development of recurrent hemorrhage.

Arteries↗
PubMedDate not supplied

Relationship between catecholamine neurons and cerebral blood vessels studied by their simultaneous fluorescent revelation in the rat brainstem.

In order to study the relationship between catecholamine neurons and cerebral blood vessels, a technique was developed which permitted the simultaneous visualization of blue-green fluorescent catecholamine neurons and red fluorescent stained blood vessels in the brain of the normal rat. Sympathetic nerve fibers were found on the major arteries and in the pia-arachnoid at the base of the brainstem and also along paramedia and lateral perforating arteries as small as 10-12 microns within the brain. Running within the parenchyma, central catecholamine nerve fibers occasionally approached and intersected smaller blood vessels, either arterioles or venules of 8-12 microns, and infrequently climbed along or encircled these vessels for a limited distance, particularly within the lateral tegmentum. Across the nuclei of the brainstem, no overall contiguity of catecholamine terminals with capillaries was apparent, and no correlation between the density of catecholamine varicosities and that of capillaries existed. Only in regions with a high density of both catecholamine varicosities and capillaries, such as in the principal olivary nucleus, did a significant overlap of the two occur. But in most cases of moderately to densely innervated and vascularized regions, such as the solitary tract nuclei, the greatest concentration of terminals appeared over the parenchyma. Regarding the blood supply to the catecholamine neurons, their perikarya did not receive a particularly dense capillary supply relative to other nuclei. However, a special relationship of catecholamine cells to blood vessels was suggested, particularly in the case of dopamine neurons in the substantia nigra by the close apposition of cellular processes to adjacent small vessels. This morphological study was undertaken to determine whether central catecholamine neurons may significantly innervate cerebral blood vessels and accordingly, may function analogously to the peripheral sympathetic adrenergic neurons in the regulation of the vascular system. Although a limited number of associations between central catecholamine nerve terminals and small blood vessels suggested the possibility of an innervation in a few regions, the lack of an overall correspondence and correlation between the two across brainstem nuclei indicated that the analogy of central catecholamine neurons to the sympathetic nervous system was inappropriate. On the other hand, evidence of contact with vessels by presumed dendrites of the catecholamine neurons suggested a possible vascular sensory function.

Adrenergic Fibers↗
PubMed1996

Extracellular superoxide dismutase in vessels and airways of humans and baboons.

Extracellular superoxide dismutase (EC SOD) is generally the least abundant SOD isozyme in tissues, while the intracellular Cu,Zn SOD is usually the most abundant isozyme. The biological significance of EC SOD is unknown. Immunolocalization studies show that EC SOD is in the connective tissue surrounding smooth muscle in vessels and airways within the lung. Endothelium derived relaxing factor, thought to be a nitric oxide (NO) species, is a primary mediator of vascular relaxation. During NO.'s diffusion between the endothelium and smooth muscle, extracellular superoxide would be the most efficient scavenger of NO(.). High levels of extracellular superoxide dismutase in vessels could, therefore, be essential to enable NO. to modulate vascular tone. To evaluate the hypothesis that vessel walls are functionally rich in extracellular superoxide scavenging capacity, this study quantitates the EC SOD levels in pulmonary and systemic vessels and in airways. Both pulmonary and systemic arteries in humans and baboons were found to contain high activities of EC SOD. The level of EC SOD in all human and baboon arteries examined is greater than or equal to the level of intracellular Cu,Zn SOD, and EC SOD accounted for over 70% of the total SOD activity in some vessels examined. Immunolocalization of EC SOD in human and baboon vessels show similar distributions of this enzyme in pulmonary and systemic vessels. EC SOD is located beneath the endothelium, surrounding smooth muscle cells, and throughout the adventitia of vessels. The high level of EC SOD in vessels, and its localization between endothelial and smooth muscle cells, suggest that regulation of superoxide may be particularly important in this region, possibly in regulating vascular tone.

Aged↗
PubMed2004

Complete versus culprit vessel percutaneous coronary intervention in multivessel disease: a randomized comparison.

BACKGROUND: The purpose of this study was to compare the safety, efficacy, and costs of complete versus "culprit" vessel revascularization in multivessel coronary artery disease treated with percutaneous coronary interventions (PCI). METHODS: Patients with multivessel disease and an identified culprit vessel were randomly assigned to complete revascularization of vessels > or =50% stenoses (n = 108) versus revascularization limited to the culprit vessel (n = 111). The primary end point, major adverse cardiac events (MACE), were defined as cardiac or noncardiac death, myocardial infarction, need for coronary artery bypass graft surgery, and repeat PCI up to 1 year. RESULTS: Despite equal MACE at 24 hours (6.3% vs 7.4%), strategy success was higher in the culprit vessel than in the complete revascularization group (93.7% vs 81.5%, P =.007). MACE rates at 1 month (14.4% vs 9.3%), 1 year (32.4% vs 26.9%), and 4.6 +/- 1.2 years (40.4% vs 34.6%) were similar in both groups. Repeat PCI was performed more often in the culprit vessel group (31.2% vs 21.2%, P =.06). A lower consumption of medical material was associated with lower procedural costs in the culprit vessel group (5784 vs 7315 Euros; P <.001). However, between 1 year and the end of follow-up, costs had equalized in both groups. CONCLUSIONS: Complete versus culprit vessel revascularization in multivessel coronary disease treated with PCI was associated with a lower strategy success rate, similar MACE rates, and initially higher costs. However, over the long term, more repeat PCIs were conducted in patients treated by culprit revascularization only, mostly because of the need to treat lesions initially left untreated. As a consequence, incremental costs had equalized within 1 year. The decision of whether to perform culprit vessel or complete revascularization can be made on an individual basis.

Adult↗
PubMed2004

Algorithm in choosing recipient vessels for perforator free flap in breast reconstruction: the role of the internal mammary perforators.

INTRODUCTION: Although the internal mammary (IM) vessels are our first choice as recipient vessels for free flap breast reconstruction, attempts to reduce surgical morbidity led us to adopt an algorithm when choosing recipient vessels. MATERIALS AND METHODS: The IM vessels give direct perforators to the breast. They can be found either superficial or deep to the pectoralis major muscle. If they are of a reasonable calibre they can be considered as recipient vessels. When the perforators are not suitable, the IM vessels are used for the microanastomosis. This protocol was adopted for our patients between June 1999 and December 2002. RESULTS: Breast reconstruction with free flaps was performed on 298 patients with perforator flaps. IM and thoracodorsal (TD) vessels are used in 88% and 3% of cases, respectively. IM perforators were successfully used in 30 cases (9%). The IM perforators used were located at the level of the second and third intercostal space in nine (30%) and 21 (70%) cases, respectively. The average diameters of those perforators were 1 mm (0.5-1.3 mm) for the artery and 1.7 mm (1-3 mm) for the vein. CONCLUSIONS: The IM perforators can be used as recipient vessels for free flaps. This spares the IM vessels for eventual cardiac bypass surgery, avoiding recipient site morbidity and decreasing the postoperative discomfort.

Algorithms↗
PubMed2005

Forest representation of vessels in cone-beam computed tomographic angiography.

Cone-beam computed tomographic angiography (CBCTA) provides a fast three-dimensional (3D) vascular imaging modality, aiming at digitally representing the spatial vascular structure in an angiographic volume. Due to the finite coverage of cone-beam scan, as well as the volume cropping in volumetric image processing, an angiographic volume may fail to contain a whole vascular tree, but rather consist of a multitude of vessel segments or subtrees. As such, it is convenient to represent multitudinal components by a forest. The vessel tracking issue then becomes component characterization/identification in the forest. The forest representation brings several conveniences for vessel tracking: (1) to sort and count the vessels in an angiographic volume, for example, according to spatial occupancy and skeleton pathlength; (2) to single out a vessel and perform in situ 3D measurement and 3D visualization in the support space; (3) to delineate individual vessels from the original angiographic volume; and (4) to cull the forest by getting rid of non-vessels and small vessels. A 3D skeletonization is used to generate component skeletons. For tree construction from skeletons, we suggest a pathlength-based procedure, which lifts the restrictions of unit-width skeleton and root determination. We experimentally demonstrate the forest representation of a dog's carotid arteries in a CBCTA system. In principle, the forest representation is useful for managing vessels in both 2D angiographic images and 3D angiographic volumes.

Angiography↗
PubMed2004

Invasion of blood vessels as significant prognostic factor in radically resected T1-3N0M0 non-small-cell lung cancer.

OBJECTIVES: Radical resection is the therapy of choice in non-small-cell lung cancer (NSCLC). However, even in early stages (T1N0, T2N0) up to 35% of patients will experience recurrence. The aim of this retrospective study was to evaluate the prognostic influence of lymph vessel or blood vessel invasion in N0 patients. METHODS: A total of 72 patients (male, 49; female, 23; median age 59; range 40-72) with NSCLC entered the study. The stages were T1-3N0 (T1, 25; T2, 41; T3, 6). Thirteen pneumonectomies and 59 lobectomies or bilobectomies with systematic lymphadenectomy and R0 resection were performed. Histologically, 24 adenocarcinomas, 31 squamous cell carcinomas and 14 subtypes of large cell carcinoma were found. In 22 cases microscopic invasion of the lymphatic vessels and in 11 invasions of blood vessels were found. Six patients showed invasion of either structure. RESULTS: The patients were followed up for at least 5 years or until death. During the follow-up period 27 patients died (21 because of recurrence and 6 because of diagnosis not related to NSCLC). The 5 years overall survival amounted to 62.5%. In cases with invasion of the blood vessels the survival rate was 23.5%, in cases without invasion 74.5% (P< or = 0.01), whereas lymph vessel invasion had no significant impact on survival. Multivariate analysis covering T stages, histological subtypes, location of the tumor, grading, age, sex, and invasion of the lymphatic or the blood vessels showed invasion of the blood vessels as the only factor with significant prognostic impact in the study population. CONCLUSIONS: In resectable N0 patients with NSCLC the microscopic invasion of blood vessels should be considered as an additional prognostic parameter.

Adult↗
PubMed2000

Experimental studies of indocyanine green dye-enhanced photocoagulation of choroidal neovascularization feeder vessels.

PURPOSE: To report a model of choroidal neovascularization feeder vessels that reconciles current histologic, angiographic, and clinical data, and to report experimental studies that investigate the potential of indocyanine-green-dye-enhanced photocoagulation to improve feeder-vessel treatment. METHODS: A model of choroidal neovascularization feeder vessels was conceived to account for current histologic and angiographic data. Based on that model, experimental studies of the efficacy of indocyanine green-dye-enhanced photocoagulation were performed, using pigmented rabbit eyes as a model system. A Zeiss fundus camera was modified to permit visualization of choroidal blood flow by high-speed indocyanine green angiography and to permit simultaneous delivery of 810-nm-wavelength diode laser photocoagulation pulses to specific choroidal vascular targets during indocyanine green-dye bolus transit. RESULTS: Choroidal neovascularization feeder vessels appear to originate in the Sattler layer (that is, that portion of the choroidal vasculature consisting of medium-diameter vessels) and enter the choriocapillaris in close proximity to the small capillary-like vessels that penetrate Bruch membrane and communicate with the choroidal neovascularization. The rabbit eye experiments demonstrated that the presence of high indocyanine green dye concentration in circulating blood enhances uptake of near-infrared laser energy (three eyes); injection of sequential indocyanine green dye boluses results in gradually decreased efficiency of dye-enhanced photocoagulation (two eyes); and by application of laser energy during the initial transit of small-volume, high-concentration indocyanine green dye boluses, dye-enhanced photocoagulation of large diameter choroidal arteries can be accomplished with relatively little concomitant retinal tissue damage (three eyes). CONCLUSIONS: Although future trials will be necessary to substantiate these initial findings in the clinical arena, it appears that the efficiency of choroidal neovascularization feeder-vessel photocoagulation may be enhanced, while minimizing concomitant damage to overlying retinal tissue, by delivery of 810-nm wavelength laser energy immediately upon arrival of a high-concentration indocyanine green dye bolus in a targeted feeder vessel. However, molecules of dye adhering to vessel walls or lying in tissue interstitial spaces appear to divert laser energy from the photocoagulation process, so efficiency of indocyanine green dye-enhanced photocoagulation gradually diminishes as the number of injected dye boluses increases.

Animals↗
PubMed2004

Inhibition of vascular endothelial growth factor (VEGF) signaling in cancer causes loss of endothelial fenestrations, regression of tumor vessels, and appearance of basement membrane ghosts.

Angiogenesis inhibitors are receiving increased attention as cancer therapeutics, but little is known of the cellular effects of these inhibitors on tumor vessels. We sought to determine whether two agents, AG013736 and VEGF-Trap, that inhibit vascular endothelial growth factor (VEGF) signaling, merely stop angiogenesis or cause regression of existing tumor vessels. Here, we report that treatment with these inhibitors caused robust and early changes in endothelial cells, pericytes, and basement membrane of vessels in spontaneous islet-cell tumors of RIP-Tag2 transgenic mice and in subcutaneously implanted Lewis lung carcinomas. Strikingly, within 24 hours, endothelial fenestrations in RIP-Tag2 tumors disappeared, vascular sprouting was suppressed, and patency and blood flow ceased in some vessels. By 7 days, vascular density decreased more than 70%, and VEGFR-2 and VEGFR-3 expression was reduced in surviving endothelial cells. Vessels in Lewis lung tumors, which lacked endothelial fenestrations, showed less regression. In both tumors, pericytes did not degenerate to the same extent as endothelial cells, and those on surviving tumor vessels acquired a more normal phenotype. Vascular basement membrane persisted after endothelial cells degenerated, providing a ghost-like record of pretreatment vessel number and location and a potential scaffold for vessel regrowth. The potent anti-vascular action observed is evidence that VEGF signaling inhibitors do more than stop angiogenesis. Early loss of endothelial fenestrations in RIP-Tag2 tumors is a clue that vessel phenotype may be predictive of exceptional sensitivity to these inhibitors.

Animals↗