SEARCH · PubMed Health

Results for “VESSELS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources

PubMed1991

Salvage of branch vessels during bifurcation lesion angioplasty: acute and long-term follow-up.

To evaluate angiographic success, frequency of branch vessel loss and salvage, and long-term outcome, we studied the early and late outcomes of 56 consecutive patients who underwent PTCA of bifurcation lesions, which involved the left anterior descending or left circumflex coronary artery, with stenoses greater than 70% in both the parent and an involved branch vessel. In 35 patients (63%), the PTCA strategy was attempted dilation of both the main vessel and the involved branch vessels using predominantly a double-wire, sequential balloon technique; in 21 (27%) the PTCA attempt was confined to the main vessel alone. Transient angiographic occlusion of the branch vessel occurred in 32% of patients in whom dilation of both vessels was attempted, and in 38% in whom the main vessel alone was dilated (p = NS); 91% of the occluded branch vessels were the salvaged when sequential angioplasty of both vessels had been initially planned, compared to only 38% when the initial strategy had been dilation of the main vessel alone (p less than .05). Predischarge exercise testing showed residual ischemia in 6% of patients who had both vessels successfully dilated, versus 37% in those in whom dilatation was confined to the main vessels (p less than .01). Clinical restenosis, defined as late (greater than 6 weeks) recurrence of angina or a positive exercise test, occurred in 42% of patients who had both vessels successfully dilated. Thus although bifurcation lesion angioplasty frequently results in transient branch vessel loss, these branches can usually be salvaged using a double-wire technique but tend to have a higher late restenosis than conventional single vessel PTCA.

Angioplasty, Balloon, Coronary↗

PubMed2005

Choice of recipient vessels in delayed TRAM flap breast reconstruction after radiotherapy.

This study compared the use of the internal mammary and thoracodorsal recipient vessels in a uniform group of patients who underwent delayed TRAM flap reconstruction after radiotherapy, focusing on usability rates and outcomes. The authors identified 123 delayed TRAM flap patients who had undergone postmastectomy radiotherapy from a prospective database (1990 to 2001). Recipient vessel unusability rates were calculated on the basis of reports of inspection of a vessel, either by direct intraoperative dissection or by findings from color Doppler examination (internal mammary vessels only). Charts were reviewed for outcomes including flap loss, vascular complications, fat necrosis, and lymphedema; t-test and chi-square analyses were performed to compare outcomes and unusability rates, and multiple regression analysis was performed to determine factors influencing outcome. Of the 123 planned free TRAM flaps, 106 were completed as free flaps and 17 were performed as pedicled flaps because of unusable recipient vessels. Of the free flaps, 45 were anastomosed to the internal mammary vessels, 55 to the thoracodorsal vessels, and six to other vessels. The internal mammary and thoracodorsal groups did not differ significantly in body mass index, abdominal scars, smoking history, time delay between irradiation and TRAM flap reconstruction, or flap ischemia time. Radiation doses to the axilla (thoracodorsal), internal mammary chain, and supraclavicular fossa were similar between the groups. The internal mammary vessels were rejected in 11 (20 percent) of 56 cases, and the thoracodorsal vessels were rejected in 19 (26 percent) of 74 cases (p = 0.42). In cases with unusable internal mammary vessels, 46 percent (n = 5) had inadequate veins, 27 percent (n = 3) had inadequate arteries, and in 27 percent (n = 3) both vessels were inadequate. In the 19 cases with unusable thoracodorsal vessels, 84 percent (n = 16) were excessively scarred, 11 percent (n = 2) had inadequate vessels, and 5 percent (n = 1) were absent. Outcomes were similar regardless of recipient vessels used (internal mammary versus thoracodorsal): total flap loss, 0 percent versus 4 percent (p = 0.20); vascular complications, 6.7 percent versus 11 percent (p = 0.46); arm lymphedema, 4.4 percent versus 9 percent (p = 0.37); partial flap loss, 9 percent versus 6 percent (p = 0.54); and fat necrosis, 18 percent versus 15 percent (p = 0.69). Multivariate analysis revealed a trend for higher complication rates in smokers and with the use of the thoracodorsal vessels as the recipients. Overall, no discernible unusability or outcome differences were detected between the internal mammary and thoracodorsal groups.

Adult↗

PubMedDate not supplied

Effects of vessel curvature on dose distributions in catheter-based intravascular brachytherapy for various radionuclides.

PURPOSE: When radioactive sources are used to treat restenosis, the blood vessels are usually curved. In catheter-based intravascular brachytherapy systems, this curvature introduces dose deviations from the idealized situation used for treatment planning, in which both blood vessels and sources are assumed to be straight. Because of the different depth characteristics of different radionuclides, it is foreseeable that the curvature effects on dosimetry might vary with the different types of radionuclides. In this study, curvature effects on dose distributions along and around a blood vessel were investigated for different gamma and beta emitters. MATERIALS/METHODS: A blood vessel was modeled as a cylinder that could be curved as a circular arc of different degrees. Dose calculations were performed on the cylindrical surfaces of the model vessel for the radioactive sources of (192)Ir, (125)I, (103)Pd, (188)Re, (32)P, and (90)Y/Sr. The radius of the vessel was assumed to be 1.0, 1.5, 2.0, and 2.5 mm, respectively. A catheter-based radiation delivery system was simulated to consist of a line source with a length of 2 cm. The dose rate at a point in space produced by the radioactive source was computed by integrating the point dose rate kernel of the corresponding radionuclide over the entire radioactive line, which was assumed to curve with the blood vessel along its central axis. Dosimetric calculations were performed for different curvature angles. The curvature effects on the dosimetry were characterized with two quantities, LDU and ADU, where LDU described the longitudinal dose uniformity (LDU) along blood vessels and ADU described the azimuthal dose uniformity (ADU) from the expected delivery dose around blood vessels. RESULTS: Vessel and source curvatures barely changed the LDU for the gamma emitters (within 2%). The curvature effects on the LDU were relatively larger for the beta emitters (less than 5%). The dose deviations caused by curvature around a blood vessel were more significant. Depending on the radius of the vessel and degree of curvature, the deviation could be as much as 25% for the gamma emitters and 30% for the beta emitters. The curvature effects became larger with the increase of vessel radius and, obviously, with the increase of curvature. There seemed to be no significant differences in the curvature effects among different types of gamma emitters and among different types of beta emitters. CONCLUSIONS: Curvature-induced effects on dose distribution are similar for both the gamma and the beta emitters. The LDU along the vessels does not change significantly with curvature. The dose changes around the vessels are more pronounced and can be as high as 30%.

Blood Vessels↗

PubMed2003

Dose distributions in bifurcated coronary vessels treated with catheter-based photon and beta emitters in intravascular brachytherapy.

The dose distributions in the bifurcated vessels treated with intravascular brachytherapyline sources are complicated and depend on the bifurcation geometry consisting of a main and a branch vessel at different angles. To investigate the dosimetric effects at the bifurcation, calculations were performed on branching vessels of various bifurcation angles ranging from 20 degrees to 90 degrees. Two catheter based delivery systems were considered in the calculations using a 40 mm long radioactive sources of 192Ir or 90Sr/Y. It was assumed that the bifurcated vessel was treated in twoseparate source insertions, once for the main vessel and later for the branch vessel. Calculations were performed for different values of source gap from 0 to 9 mm, at the junction of main and branch vessels. Our results indicate that main vessel always receives a higher dose (up to 200%) when the branch vessel is also treated. Hot spots at portions of the main vessel near the junction cannot be totally avoided without severely underdosing the branch vessel. For bifurcation angle greater than 45 degrees, a 4 mm source gap can almost ensure that overdosing of the main vessel does not exceed 60% and underdosing of the branch vessel does not exceed 10% for 192Ir. However, for 90Sr/Y, the same is not possible unless the bifurcation angle is larger than 70 degrees. Dose heterogeneity using 90Sr/Y is more sensitive to the value of source gap than 192Ir because 90Sr/Y source provides a sharper dose-fall-off than 192Ir. For both photon and beta emitters, there is no acceptable solution for bifurcation angles less than 30 degrees, where the activity of the line source has a uniform distributions. Appropriate choice of gap at the junction can only help to reduce either overdosing of the main vessel or underdosing of the branch vessel, but not both.

Beta Particles↗

PubMed2004

High LYVE-1-positive lymphatic vessel numbers are associated with poor outcome in breast cancer.

PURPOSE: The clinical significance of intratumoral or peritumoral lymph vessel density is not known. LYVE-1, a lymphatic endothelium-specific hyaluronan receptor, is a novel lymphatic vessel marker that is expressed on lymph vessel endothelial cells of both normal and neoplastic tissues. EXPERIMENTAL DESIGN: We investigated expression of LYVE-1 by immunohistochemistry in 180 unilateral, invasive ductal breast carcinomas and assessed the presence and density of lymph vessels within the tumor and at the tumor periphery. RESULTS: A minority (12%) of breast carcinomas had intratumoral lymph vessels, whereas peritumoral lymph vessels were identified in almost all cases (94%). No substantial association was found between the number of LYVE-1-positive vessels and the number of CD31 or vascular endothelial growth factor receptor-3-positive vessels, or vascular endothelial growth factor-C expression. The number of metastatic axillary lymph nodes increased in parallel with increasing lymph vessel counts (P = 0.033). A higher than the median lymph vessel count at the tumor periphery was significantly associated with unfavorable distant disease-free survival and overall survival. Women with high peritumoral lymph vessel density had only 58% (95% confidence interval, 46-70%) 5-year distant disease-free survival as compared with 74% (66-83%) among those with a low peritumoral lymph vessel density (P = 0.0088). In contrast, the presence of intratumoral lymph vessels was associated with neither axillary nodal status nor survival. Lymph vessel density was not an independent prognostic factor in a multivariate survival analysis. CONCLUSIONS: A high peritumoral lymph vessel density is associated with a poor outcome in ductal breast cancer.

Adult↗

PubMed1983

Comparison of blood vessel wall dimensions in normotensive hypertensive rats by histometric and morphometric methods.

The histometric method is often used in hypertension studies in order to reconstruct, from cross-sectional profiles of vessels in the contracted state, a hypothetical relaxed state of the vessels based on the measured length of the internal elastic lamina (IEL). In this study, the accuracy of the histometric method was tested by comparing values obtained with the histometric method from contracted vessels versus values from morphometric measurements of vessels of the same calibre but maximally relaxed. Mesenteric arteries from spontaneously hypertensive and normotensive Wistar-Kyoto rats were used. We found that the lumen size of the vessels was dependent on the methods of measurement and preparation. Lumen size, determined with the histometric method from contracted vessels, tended to be underestimated mainly because the IEL became shortened during contraction of the vessels. When vessels were prepared by perfusion fixation, a high perfusion flow rate (7.6 ml/min) caused expansion of the lumen in muscular (lumen diameter 120--250 microns) and arteriolar vessels (40--100 microns), but not in the elastic arteries (400--700 microns). The cross-sectional area of the vessel wall, however, remained unchanged when the vessels were either contracted with norepinephrine or expanded with high transmural pressure, so morphometric measurements of the vessel wall and its components can be done on both contracted and relaxed vessels. Our results suggest that the use of the histometric method for the estimation of relaxed lumen size from the contracted vessels is of very limited value. We also suggest that, for an accurate comparison of vessel wall dimensions between hypertensive and normotensive animals, cross-sectional area should be used instead of wall thickness alone.

Animals↗

PubMed1997

Identification of lymphatic vessels by using a monoclonal antibody specific for the human thoracic duct.

Light microscopic identification of lymphatic vessels of the human small intestine was studied immuno-histochemically with a monoclonal antibody specific for human thoracic duct (mAb-D) and rabbit anti-human laminin antibody (anti-L). Two types of vessels were observed with anti-L; one strongly reacted with regularly outlined vessels and the other weakly reacted with irregularly outlined vessels and thin walls. Immunoreactivity to mAb-D was strong in the weakly reacting vessels, and the strongly reacting vessels did not react to mAb-D. Immunoreactivity of lymphatic vessels to anti-L has been reported to be weaker than that of the blood vessels; only irregularly outlined vessels which were weakly immunostained with anti-L reacted to mAb-D and no cross-reaction to mAb-D was observed in the regularly outlined vessels. This indicates that the vessels strongly reacting with anti-L are blood vessels and the vessels immunostained with mAb-D must be lymphatics. The study shows that it is possible to identify lymphatic vessels light microscopically by mAb-D. This method will be useful in studying the fine distribution of lymphatic vessels in normal tissue and also in pathological tissue such as metastasis of malignant tumors.

Aged↗

PubMed1978

[The vessels of the inner ear (author's transl)].

The inner ear as an example of a highly specialized sensory organ also possesses a highly specialized vascularisation. This represents an impressive example for a reasonable adaption of the terminal blood vessels to a specific function of the organ fulfilling more than only the nutrition. In this paper the microvascular bed of the cochlea is examined using both the injection method of the vessels and the biomicroscopic observation in vivo. The combination of these technics supported by histologic and stereoscan microscopic examinations has made it possible to give an account of the functional morphology of the inner ear vessels. As a detailed structural analysis of the vessels morphology with the help of dyes that fill the whole of the vessels space (i.e. Berlin blue) is not possible, perfusion experiments with silver nitrate were performed on the inner ear. After the perfusion the vessels are cleaned again, the silver however imbibes the intercellular reticular substances and after exposure produces a continous and sharp framework of the endothelium and--when present--muscular cells, thus showing the angioarchitectural contours. There is a very clear division of the cochlear vessels in a three dimensional space: The arterial and venous vessels are vividly separated from one another, forming two systems of microvascular units in the lateral wall and the spiral lamina. Each unit begins with special blood vessel convoluts in the modiolus, consisting of loops of arterioles. They are weakly muscularized whereas no muscle structures are seen elsewhere in the other parts of the inner ear vessels. There are no a.-v. anastomoses or sphinkters at all. The function of the vessel loops in the modiolus is to flatten the pulse wave as well as to regulate the blood flow in the microvascular bed by vasomotion. This was proved by statistical examinations of 1200 measurements of the widths of the vessels at several points of the cochlea in a blind study with and without vasoactive drugs. The terminology of the vessels is not standardized. The nomenclature in this paper has regard to the classification of the vessels, the course and the topographic localisation. Silver staining reveals changes in the form of the endothelium cells from the arterial towards the venous end. While the arteries show a long stretched spinle or lancet like form they change over blunt, oval, triangular or rhomboid forms into polygonal cells with spiked border lines at the venules. All experiments together give an account that the blood supply of the inner ear is in close correlation with the blood supply of the brain and too possesses autoregulative mechanisms, which must be localized in the convoluts at the beginning of every microvascular unit of the cochlear vessels.

Arterioles↗

PubMed1993

Prevalence and risk factors for aortopulmonary collateral vessels after Fontan and bidirectional Glenn procedures.

OBJECTIVES: The purpose of this study was to evaluate the prevalence of and risk factors for aortopulmonary collateral vessels in patients who have undergone a bidirectional Glenn or Fontan procedure, or both. BACKGROUND: Aortopulmonary collateral vessels are frequently observed angiographically in patients after a bidirectional Glenn or Fontan procedure. These vessels may provide a source of pulmonary blood flow competitive with anterograde cavopulmonary flow. METHODS: We performed a retrospective study of all patients (n = 196) who underwent catheterization between January 1, 1988 and February 29, 1992 (n = 268) after bidirectional Glenn or Fontan procedures and reviewed clinical, hemodynamic and angiographic phone data. RESULTS: Collateral vessels were diagnosed in 36% of patients. Patients who underwent the bidirectional Glenn procedure were more likely to have collateral vessels than patients who underwent the Fontan procedure (65% vs. 30%, respectively; p < 0.0001). Patients with a history of a Blalock-Taussig shunt were more likely to have collateral vessels than those without (50% vs. 24%, respectively; p = 0.0006). Discretely identifiable collateral vessels were measurable in 54 (20%) of 268 catheterizations. The total estimated cross-sectional area of these vessels averaged 10.7 +/- 7.2 mm2. In patients who underwent the bidirectional Glenn procedure, a step-up in oxygen saturation from the superior vena cava to the distal pulmonary arteries or an upper lobe filling defect, or both, on pulmonary angiogram predicted total estimated cross-sectional area of collateral vessels. Most collateral vessels originated from the internal mammary arteries (34%) and the thyrocervical trunks (22%). Only 9% of collateral vessels arising from the brachiocephalic vessels were visualized by aortogram; the remainder required selective angiography in the subclavian or more distal arteries. CONCLUSIONS: Aortopulmonary collateral vessels are common after bidirectional Glenn and Fontan procedures. Aortograms often fail to diagnose their presence. The left to right shunt carried by these vessels is associated with a step-up in oxygen saturation in the distal pulmonary arteries. The clinical significance and indications for closure of these vessels are not known.

Adolescent↗

PubMed1995

Percutaneous transluminal coronary angioplasty as a first revascularization procedure in single-, double- and triple-vessel coronary artery disease.

OBJECTIVES: We sought to compare in-hospital and long-term outcome after angioplasty in patients with single-, double- and triple-vessel disease. BACKGROUND: Coronary angioplasty is increasingly used in patients with multivessel disease. METHODS: The source of data was the clinical data base at Emory University. Patients who had previous coronary revascularization or who underwent angioplasty in the setting of acute myocardial infarction were excluded. RESULTS: Of 10,783 patients, 71% had one-vessel, 24% two-vessel and 5% three-vessel disease. Age, male gender, diabetes, hypertension, history of previous myocardial infarction, Canadian Cardiovascular Society class III or IV angina and congestive failure all increased with severity of disease. Complete revascularization was achieved in most patients with one-vessel disease, in a minority with two-vessel disease and rarely in those with three-vessel disease. Emergency coronary bypass surgery increased from 1.7% with one-vessel disease to 3.2% with three-vessel disease. Q wave myocardial infarctions could not be shown to vary significantly with severity of disease. The mortality rate increased from 0.2% with one-vessel disease to 1.2% with three-vessel disease. The number of vessels diseased was a multivariate correlate of in-hospital and long-term mortality. The 1-, 5- and 10-year survival was 0.99, 0.93 and 0.86 for one-vessel disease and 0.97, 0.89 and 0.76 for two-vessel disease, respectively. The 1-, 5- and 9-year survival was 0.95, 0.85 and 0.70 in three-vessel disease, respectively. Freedom from myocardial infarction, coronary bypass surgery and repeat angioplasty was also lower with more severe disease. CONCLUSIONS: Patients have increasing in-hospital and long-term mortality as the severity of disease increases. There is also an increased incidence of myocardial infarction and revascularization procedures with more severe disease.

Aged↗

PubMed1996

The fate of bypass grafts to angiographically occult runoff vessels detected by magnetic resonance angiography.

PURPOSE: Magnetic resonance angiography (MRA) is a noninvasive vascular imaging technique that is more sensitive than contrast arteriography (CA) for the detection of patent distal runoff vessels. This technique has facilitated performance of MRA-directed bypass procedures for patients who were believed not to be bypass candidates because of the absence of a suitable target vessel on the preoperative CA. The fate of bypasses to these angiographically occult runoff vessels is unknown, however, and it has been proposed that patients with angiographically occult runoff may have aggressive occlusive disease, rendering bypass procedures ultimately futile. METHODS: Between April 1992 and February 1995, 212 autogenous vein infrageniculate bypasses were performed for limb-salvage indications, 22 (12%) to angiographically occult runoff vessels. Results of bypasses performed to angiographically occult vessels were compared with those of bypasses to CA-detected runoff vessels. Life-table analysis of graft-patency and limb-salvage rates was performed. RESULTS: The accuracy of the MRA-predicted patency of angiographically occult vessels was confirmed in every case by the operative findings. Life-table analysis revealed no significant difference in primary graft patency (p > 0.05) or limb-salvage (p > 0.05) rates between patients with bypasses to runoff vessels seen by MRA alone. At 35 months after surgery, the primary graft patency rate was 68% for bypasses to CA-detected vessel bypass and 67% for MRA-detected vessels. The limb salvage rate was 83% for CA-detected vessel bypass patients and 78% for patients with angiographically occult runoff. CONCLUSIONS: MRA can accurately identify patent runoff vessels not visualized by CA. Results of bypasses performed to angiographically occult runoff vessels are similar to those of bypasses performed to vessels detected by CA. MRA should be performed in patients in whom CA fails to reveal runoff vessels suitable for use in a limb-salvage procedure. The greater sensitivity of MRA may facilitate successful bypass surgery and improve the overall limb-salvage rate.

Aged↗

PubMed2006

Selecting earlywood vessels to maximize their environmental signal.

The anatomical features of earlywood vessels often reflect information about past climatic conditions. We examined the relationships between mean monthly temperature and mean vessel lumen area (MVA) in various categories of earlywood vessels. Subsets of earlywood vessels of chestnut (Castanea sativa Mill.) were selected from a previously reported dataset based on several progressive size-related procedures. To include all earlywood vessels, the minimum size considered was 10,000 microm2. Changes in the correlations between MVA and the mean air temperature in March are described and discussed. The results show that not all vessels embody the same information. The MVA of a proportion of the largest earlywood vessels in each annual ring was most closely related to March temperature, whereas MVA of the smallest earlywood vessels was better correlated with June temperature. This difference is probably a result of the vessels being formed at different times: early spring for the largest earlywood vessels and later in spring for the smallest earlywood vessels. Analyses combining large and small vessels yielded lower correlations between MVA and monthly temperature. The number, size and distribution of vessels can vary greatly from ring to ring. In making year-to-year comparisons, the best information is provided by observations on vessels of contemporaneous ontogenesis. Criteria for the selection and analysis of vessels in the assessment of temperature during the season of wood formation are proposed and discussed.

Climate↗

PubMed1994

Restenosis following elective implantation of single Palmaz-Schatz stents in de-novo lesions in native vessels.

BACKGROUND: Restenosis is the main limitation of long-term success after coronary angioplasty. Intracoronary stent implantation may reduce restenosis by producing a larger initial lumen and eliminating recoil. The objective of this study was to determine the frequency of and features associated with restenosis after elective single Palmaz-Schatz stent implantation in de-novo lesions in native vessels. METHODS: Eighty consecutive patients were studied. Angiographic follow-up was performed in 79 out of 80 (99%) 6.5 +/- 3.4 months after the procedure. Angiographic measurements were performed using an automated computerized quantitative angiographic analysis system. RESULTS: Restenosis (> or = 50% stenosis) at follow-up occurred in 26 out of 79 patients (33%). The frequency of complex lesion morphology was higher (50% versus 19% American College of Cardiology/American Heart Association classification B2; P = 0.005), the reference vessel diameter larger (3.0 +/- 0.5 mm versus 2.8 +/- 0.6 mm, P = 0.049), and the lesion length longer (10.9 +/- 3.5 mm versus 8.5 +/- 3.5 mm, P = 0.009) in the restenosis group compared with the non-restenosis group. The population was divided into three groups according to the reference vessel diameter: (1) greater than 3.0 mm (n = 27), (2) 2.5-3.0 mm (n = 29), and (3) less than 2.5 mm (n = 22). One patient was excluded from this subgroup analysis because of difficulty in determining the reference vessel diameter before the procedure. The restenosis rates were 52%, 37%, and 11%, respectively, for the three groups (P = 0.02). The relative acute gain was greater in the smaller vessels, (0.66 in the < 2.5 mm vessels, 0.53 in the 2.5-3.0 mm vessels, and 0.48 in the > 3.0 mm vessels; P = 0.006). This was associated with a relative oversizing of the final stent balloon in the smaller vessels (balloon-to-vessel ratio of 1.33 in the vessels < 2.5 mm diameter, 1.16 in the 2.5-3.0 mm vessels, and 0.98 in the > 3.0 mm vessels; P = 0.001). CONCLUSION: The frequency of restenosis in single electively implanted Palmaz-Schatz stents in de-novo lesions in native vessels was 33%. The degree of restenosis was lower in smaller vessels, in which a better initial result was associated with relative oversizing of the final stent balloon. More aggressive dilation within the stented segment may result in a lower restenosis rate.

Aged↗

PubMed2003

An outcome analysis comparing the thoracodorsal and internal mammary vessels as recipient sites for microvascular breast reconstruction: a prospective study of 100 patients.

The thoracodorsal vessels have been the standard recipient vessels for the majority of surgeons performing free transverse rectus abdominis musculocutaneous (TRAM) flap reconstructions. Recently, the internal mammary vessels have been recommended as the first-choice recipient vessels for microvascular breast reconstruction. This approach requires a shorter pedicle length, allows for central placement of flap tissue, and avoids axillary scarring. The use of the internal mammary vessels may provide for a shorter operative time and a higher-quality aesthetic reconstruction. The authors performed a prospective trial examining the differences in operative and aesthetic outcomes between each recipient site. A prospective trial of 108 consecutive free-tissue transfers was conducted in 100 patients. The first 60 TRAM flap patients were randomized so that 30 flaps were anastomosed to the internal mammary vessels and 30 were anastomosed to the thoracodorsal vessels, whereas the recipient vessels for the remaining 40 patients were left to the discretion of the surgeon. Of the 40 nonrandomized patients, 10 patients underwent reconstruction using the internal mammary vessels and 30 patients underwent reconstruction using the thoracodorsal vessels. The patients' medical history and hospital course were noted. To evaluate aesthetic outcome, a group of five blinded nonmedical observers and three blinded plastic surgeons graded the reconstructions in the 60 TRAM flap patients for symmetry and overall aesthetic result on a scale of 1 to 5. Blinded practitioners administered postoperative questionnaires to patients regarding recovery time and satisfaction with the aesthetic result. Forty-three flaps were transferred to the internal mammary vessels and 65 were transferred to the thoracodorsal vessels. No significant differences existed between groups with regard to age of preoperative risk factors. Average operative time was 6 hours in each group. Average hospital stay was 5.8 days in each group. Conversion from initial recipient vessel to a secondary recipient site occurred in 12.5 percent of internal mammary reconstructions and 7 percent of thoracodorsal reconstructions. All converted internal mammary cases occurred in left-sided reconstructions and were attributable to problems with the veins. Overall, 20 percent of left-sided internal mammary reconstructions were found to have an inadequate recipient vein. Unusable thoracodorsal vessels were found only in delayed reconstructions, at a rate of 15 percent in the delayed setting. All flaps from converted procedures survived without complications. Average follow-up was 20 months, during which time there was one flap loss in the thoracodorsal group. There were no significant differences in complication rates between groups. Average aesthetic grade was 3.6 in each group. Postoperative recovery time and overall patient satisfaction were not significantly different between groups. Either recipient site can provide for a safe and acceptable result; however, surgeons should be aware of conversion rates and plan appropriately if recipient vessels appear unusable for free-tissue transfer.

Anastomosis, Surgical↗

PubMed2005

Sturge-Weber syndrome: altered blood vessel fibronectin expression and morphology.

Sturge-Weber syndrome presents with vascular malformations of the brain, skin, and eye. Fibronectin has potent effects on angiogenesis, vessel remodeling, and vessel innervation density. To determine fibronectin expression in the blood vessels of Sturge-Weber syndrome brain and skin tissue and to quantify the density and circumference of Sturge-Weber syndrome blood vessels by type compared with controls, we performed in situ hybridization for fibronectin messenger ribonucleic acid (RNA) expression on six Sturge-Weber syndrome cortical brain samples, six epilepsy brain samples, skin from two port-wine stain skin lesions, and two normal skin samples from two subjects with Sturge-Weber syndrome. Fibronectin messenger RNA was expressed in blood vessels and endothelial cells in the parenchyma of both Sturge-Weber syndrome and control brain tissues and in skin samples. Fibronectin expression was significantly reduced by 23% in the Sturge-Weber syndrome meningeal vessels compared with the epilepsy controls (P < .01). Fibronectin expression was significantly increased by 19% in the Sturge-Weber syndrome parenchymal vessels compared with the epilepsy controls (P < .05). No difference was found in the expression of fibronectin in port-wine stain skin blood vessels. The density of leptomeningeal blood vessels in the Sturge-Weber syndrome brain tissue samples was 45% greater than in the epilepsy samples (P < .05). Blood vessel circumference was significantly decreased in the Sturge-Weber syndrome meningeal vessels compared with the controls (27%; P < .05). When blood vessels from different brain regions were compared, fibronectin expression was decreased in Sturge-Weber syndrome meningeal vessels and was increased in the parenchymal vessels. Altered blood vessel fibronectin expression in Sturge-Weber syndrome could contribute to abnormal vascular structure and function in this disorder.

Brain↗

PubMedDate not supplied

Central nervous control of venous tone. III. Responses of capacitance and resistance vessels of skin to bulbar and hypothalamic stimulation.

Electrical stimulation of 350 points in the bulbar formation of 35 dogs under chloralose anaesthesia demonstrated the presence of sites producing increase or decrease of systemic arterial pressure (SAP) in the same general morphological limits of bulbar pressor and depressor regions as described by earlier authors. Simultaneous recording of pressure changes in the cutaneous vessels however demonstrated that pressure changes in these vessels did not correspond to the pressor or depressor effects of the SAP. Instead, responses were obtained in which pressures in cutaneous capacitance and resistance vessels followed a trend which was opposite in direction and magnitude to that of SAP. Thus there were 30 depressor sites which produce increase in cutaneous vessel pressure and 23 pressor sites which produced a fall in cutaneous vessel pressure. For a marked rise in the SAP, only 62 sites elicited equally marked increase in both capacitance and resistance vessel pressure, while another 52 elicited only a small increase of equivalent magnitude in the capacitance and resistance vessels. Stimulation of 84 points produced dissimilar effects on capacitance and resistance vessels out of which 38 elicited moderate increase in resistance vessel tone with minimal changes in the capacitance vessel tone, while 46 points elicited moderate increase in capacitance vessel tone with only a small increase in the resistance vessel tone. These points were diffusely admixed in the bulbar reticular formation. Effects which were exclusive to the capacitance and resistance vessels of skin, singly or in combination, without affecting the SAP were elicited from 12 points while another 28 points produced marked rise or fall of systemic arterial pressure without affecting the cutaneous vessels. These observations suggest that the neuronal organisation regulating cardiovascular activities at the bulbar level is quite complex having the capacity to generate varying activities in different components of the vascular circuits by differentially altering the discharge of the efferent sympathetic fibres on the one hand, and marked selectivity of action on any particular vascular bed or circulatory component on the other hand. Stimulation of 93 points in the hypothalamus produced similar patterns of response as obtained from medulla oblongata. In addition, stimulation of 6 points in the anterior hypothalamus produced a distinctive response accompanied by dilatation of cutaneous resistance and capacitance vessels with marked increase in respiratory rate and minimal changes in the SAP. This type of response which resembled the physiological response employed for heat loss was not obtained from any stimulation site in the medulla oblongata.

Animals↗

PubMed2004

Accuracy of quantitative MR vessel wall imaging applying a semi-automated gradient detection algorithm--a validation study.

UNLABELLED: Magnetic resonance imaging (MRI) is uniquely suited to study the pathophysiology of arteriosclerosis. So far, magnetic resonance (MR) measurements of vessel dimensions have mainly been done by manual tracing of vessel wall contours. However, such data postprocessing is very time-consuming and has limited accuracy due to difficulties in precise tracing of the thin vessel wall. PURPOSE: To assess the accuracy and reproducibility of quantitative vascular MR imaging applying a data analysis method based on (1) vessel wall unwrapping, followed by (2) a gradient detection algorithm for MR data postprocessing. Vascular MR imaging studies were done both in vessel phantoms and in healthy volunteers (n=29) on a clinical 1.5 T MR scanner. A dark blood double-inversion turbo spin echo sequence with fat suppression was applied, with proton-density-weighted and breath-hold acquisition for aortic imaging and T2-weighted acquisition for carotid imaging. Intraobserver and interobserver variability were systematically evaluated by two independent observers. A repeat study within 10 days of the first MRI was performed in 10 of these subjects for assessment of interstudy reproducibility. RESULTS: The semiautomated edge detection software revealed a clear view of the inner and outer vessel wall boundaries both in the phantoms and in the volunteers studied. There was close agreement between MR-derived measurements and phantom dimensions (mean difference of 1.1+/-16.9 mm2, 8.0+/-19.9 mm2, 9.0+/-12.1 mm2 for vessel wall cross-sectional area, inner vessel area, and total vessel area, respectively). Quantification of vessel dimensions was feasible in all 29 healthy volunteers studied. Semiautomated quantification of cross-sectional vessel wall area (mean+/-SD, 253.6+/-208.4 mm2) revealed close correlation for repeated measurements by one or two observers (r=0.99 each). Both intraobserver and interobserver variability of vessel wall area MR measurements were low (mean difference 7.5+/-16.7 mm2 and 14.4+/-24.6 mm2 , respectively). In the repeat study of 10 volunteers, MRI with semiautomated postprocessing quantitation revealed a high correlation and agreement of vessel dimensions between the two scans (r=0.994, mean difference 2.6+/-25.1 mm2). CONCLUSION: Semiautomated analysis methods can provide approaches that benefit from the human understanding of the image and the computer's ability to measure precisely and rapidly. Thus, by combining the latest MRI methods and semiautomated image analysis methods, we are now able to reproducibly determine the geometric parameters of blood vessels.

Adult↗

PubMed1994

Influence of coronary vessel size on renarrowing process and late angiographic outcome after successful balloon angioplasty.

BACKGROUND: Although coronary angioplasty is increasingly applied in the treatment of multivessel disease and a broadening range of vessel size, the influence of vessel size itself on the late results of intervention is unresolved. An influence of vessel size on late outcome would carry implications for the application and evaluation of interventional devices, which are selectively used in larger or smaller vessels. The purpose of the present study was to investigate the influence of vessel size on both the restenosis process and late angiographic outcome in a large homogeneous patient group after successful percutaneous transluminal coronary angioplasty (PTCA). METHODS AND RESULTS: The study population comprised 3072 patients with 3736 successfully dilated native primary coronary artery lesions and satisfactory quantitative angiographic analysis in multiple identical projections before and after PTCA and at a 6-month follow-up. Late luminal loss, minimal luminal diameter (MLD) at follow-up, and net luminal gain, as well as percent diameter stenosis at follow-up, net gain in percent diameter stenosis, restenosis rates (according to three definitions), and net gain index, were all compared among nine equally sized groups (noniles) according to vessel size. A direct influence of vessel size on continuous measures of late result was also evaluated by linear regression. These evaluations provided conflicting information with no consistent influence of vessel size emerging. To elucidate the independent influence of vessel size on the restenosis process (late loss) and late angiographic outcome (MLD at follow-up), multiple linear regression analysis was performed taking into account luminal gain, preprocedural MLD, and lesion location. In this manner, vessel size was found to be exert a significantly positive influence on MLD at follow-up (P < .0001) and an equally negative effect on loss. Correcting for vessel size by using percent stenosis measurements led to an anticipated neutralization of this influence. Lesion location in the left anterior descending coronary artery was found to be independently associated with greater loss and smaller MLD at follow-up (P < .0001). CONCLUSIONS: Increasing coronary vessel size was found to be independently predictive of decreasing late luminal loss and increasing follow-up MLD after successful balloon angioplasty. Apparently superior or inferior late angiographic results of new interventional devices may thus be explained in part by preferential use in larger or smaller vessels, respectively. Devices that can safely optimize the short-term result of intervention may realize their ultimate long-term value in larger coronary vessels.

Aged↗