Vessel Diameter In Patients Research Articles

Pre-operative exercise therapy to increase blood vessel diameter in patients undergoing radiocephalic arteriovenous fistula creation

Background Post-operative upper extremity exercise is recommended to patients with arteriovenous fistulas. It is postulated that increased blood flow to vessels improves maturation and patency rates. Recent studies favour pre-operative exercise therapy to improve the outcomes of arteriovenous fistula creation. Objectives To investigate if pre-operative exercise therapy increases vessel diameter and maturation in patients undergoing distal arteriovenous fistula creation. Methods 34 patients planned for radiocephalic arteriovenous fistula creation were recruited at a tertiary university hospital Vascular Surgery Unit. Patients underwent a 6-week period of self-directed daily upper extremity exercises before surgery. Patients were reviewed up to 6 months post-surgery. The primary outcome investigated was change in venous and arterial diameters following exercise intervention. The secondary outcome investigated was the primary failure rate of the newly created arteriovenous fistulas. Results After exercise therapy, mean hand grip strength increased from 20.3 ± 6.62 kg to 21.9 ± 7.16 kg ( p=.01). There was a statistically significant increase in basilic vein diameter amongst those who demonstrated strict compliance to at least 42 days of pre-operative exercise therapy by 0.51 mm from 3.23 ± 1.09 mm to 3.74 ± 1.31 mm ( p=.03). Primary failure rate of newly created radiocephalic arteriovenous fistulas was 25% (7 of 28), comparable to our previous series of 436 distal arteriovenous fistulas created which had a failure rate of 26%. Conclusions There was a trend of increase in vein diameters after pre-operative exercise therapy. Although not statistically significant, patients with successful arteriovenous fistula creation had longer mean completion of exercise days.

Changes and significance of retinal blood oxygen saturation and oxidative stress indexes in patients with diabetic retinopathy.

BACKGROUNDDiabetic retinopathy (DR) is a diabetic complication that can severely affect the patients’ vision, eventually leading to blindness. DR is the most important manifestation of diabetic micro-vasculopathy and is mainly related to the course of diabetes and the degree of blood glucose control, while the age of diabetes onset, sex, and type of diabetes have little influence on it. AIMTo explore the changes in blood oxygen saturation and oxidative stress indices of retinal vessels in patients with DR.METHODSIn total, 94 patients (94 eyes) with DR (DR group) diagnosed at Jianyang people’s Hospital between March 2019 and June 2020, and 100 volunteers (100 eyes) (control group) without eye diseases, were included in this study. Arterial and venous blood oxygen saturation, retinal arteriovenous vessel diameter, and serum oxidative stress indicators in the two groups were compared. Based on the stage of the disease, the DR group was divided into the simple DR and proliferative DR groups for stratified analysis. RESULTSThe oxygen saturation of the retinal vessels in the DR group was significantly higher than that in the control group (P < 0.05). The retinal vessel diameters between the DR and control groups were not significantly different. The serum malondialdehyde (MDA) and 8-hydroxydehydroguanosine (8-OHdG) levels in the DR group were significantly higher than those in the control group (P < 0.05). The serum superoxide dismutase (SOD) and reduced glutathione (GSH) levels in the DR group were significantly lower than those in the control group (P < 0.05). The oxygen saturation of the retinal vessels in the patients with proliferative DR was significantly higher than that in the patients with simple DR (P < 0.05). The retinal vessel diameter in patients with proliferative DR was not significantly different from that of patients with simple DR (P > 0.05). Serum MDA and 8-OHdG levels in patients with proliferative DR were significantly higher than those in patients with simple DR (P < 0.05). Serum SOD and GSH levels in patients with proliferative DR were significantly lower than those in patients with simple DR (P < 0.05).CONCLUSIONIncreased blood oxygen saturation of retinal arteries and veins and increased oxidative stress damage in patients with DR may be associated with decreased retinal capillary permeability and arterial oxygen dispersion, possibly reflecting the patient’s condition.

Short-term effect of angiotensin-converting enzyme inhibitor on retinal vessel diameter in patients with systemic hypertension

Purpose To determine the retinal vessel diameter changes after angiotensin-converting enzyme (ACE) inhibitor treatment in a group of hypertensive patients. Methods This study included 60 treatment-naive hypertensive patients who were treated with ACE inhibitor. Sixty healthy volunteers served as control group. An optical coherence tomography scan protocol including the measurement of peripapillary retinal vessel diameters was performed at baseline and at 1st month. The diameters of superior temporal artery (STA), inferior temporal artery (ITA), superior temporal vein (STV), inferior temporal vein (ITV), superior nasal artery (SNA), inferior nasal artery (INA), superior nasal vein (SNV) and inferior nasal vein (INV) were statistically compared. Results The baseline diameters of the STA, ITA, SNA, and INA were significantly decreased in the patient group compared with the control group (all p < 0.05). There was a significant increase at 1st month after the treatment in comparison to baseline measurements (all p < 0.05). When compared with the controls, only the diameter of SNV showed a significant decrease at baseline (p = 0.031). After the treatment, the diameters of SNV and INV were significantly increased compared with baseline measurements (p = 0.049 and p = 0.035, respectively). There were no significant differences between the control group and the patient group at 1st month (all p > 0.05). Conclusion Short-term treatment with ACE inhibitor led to a significant improvement in the retinal vessel diameters of patients with hypertension.

Retinal oxygen saturation and vessel diameter in patients with chronic kidney disease.

To investigate changes in retinal oximetry and the diameter of retinal vasculature in patients with chronic kidney disease (CKD) and relationships between retinal vasculature and the estimated glomerular filtration rate (eGFR), provide a scientific basis for the early detection and diagnosis of CKD. Eighty-three patients with CKD and 103 healthy individuals were included after providing informed consent. All participants were examined using a noninvasive technology (Oxymap Inc., Reykjavik, Iceland) for measuring the arterial (SaO2 ) and venous (SvO2 ) oxygen saturation and the arteriovenous difference in oxygen saturation (Sa-vO2 ). The corresponding retinal vessel diameters of these arterioles (D-A) and venules (D-V) were measured. The eGFR of patients with CKD was calculated from the serum creatinine concentration. In general, patients with CKD had higher mean SaO2 values than healthy individuals (100.15±4.68% versus 97.14±4.22%; p<0.001, mean±SD). The mean SaO2 in the superior temporal, superior nasal and inferior nasal quadrants significantly increased. There was no significant difference measured in the SvO2 when patients with CKD (63.66±5.29%) and healthy individuals (62.70±5.27%) were compared. The mean Sa-vO2 of the CKD group (36.49±4.98%) was increased compared with normal subjects (34.44±4.76%) (p=0.005). The retinal arteriole diameter was narrower in patients with CKD than in normal individuals (117.53±14.88μm versus 126.87±14.98μm; p<0.001, mean±SD), and the arteriovenous ratio was smaller than in normal individuals (0.71±0.09 versus 0.77±0.09; p<0.001, mean±SD). Pearson's two-tailed correlation showed a significant correlation between the SaO2 and eGFR (R=-0.363, p=0.001), and narrower retinal arterial calibre was significantly associated with a lower eGFR (R=0.415, p<0.001). Based on our results, there were alterations in retinal oxygen saturation and vascular diameter in patients with CKD. Further studies are needed to determine whether such changes play a role in the development of CKD.

Analysis of Foveal and Parafoveal Microvascular Density and Retinal Vessel Caliber Alteration in Inactive Graves' Ophthalmopathy.

Purpose We aimed to evaluate foveal and parafoveal density using optical coherence tomography angiography and the alteration on the retinal vessel diameter in patients with inactive Graves' ophthalmopathy compared to age-matched normal population. Materials and Methods. Patients with inactive Graves' ophthalmopathy (study group) and healthy individuals (control group) were enrolled in the cross sectionally designed study. The optical coherence tomography angiography parameters and retinal vessel diameter measurements were assessed between the study and control groups. Foveal and parafoveal microvascular density in the retina was measured using optical coherence tomography angiography. Retinal artery and vein diameter and artery/vein ratio were assessed for retinal vessel caliber changes. Results Patients with inactive Graves' ophthalmopathy had higher values of intraocular pressure, proptosis, and axial length (P=0.001, P=0.001, P=0.001, P=0.001, P=0.001, P=0.001, P=0.001, P=0.001, P=0.001, P=0.001, P=0.001, Conclusion Optical coherence tomography angiography could be a novel and promising noninvasive diagnostic technique in patients with inactive Graves' ophthalmopathy to detect foveal and parafoveal vessel density changes compared to healthy subjects. The decrease of retinal vessel diameter might be observed in patients with inactive graves ophthalmopathy.

Short-time effect of intravitreal injections on retinal vascular oxygenation and vessel diameter in patients with diabetic macular oedema or neovascular age-related macular degeneration.

PurposeTo investigate the short‐time effect of intravitreal injections (IVI) of the vascular endothelial growth factor inhibitors ranibizumab and aflibercept on retinal arterial and venous oxygen saturation (SO2a and SO2v), arteriovenous oxygen saturation difference (AVD) and vessel diameter (VDa and VDv) in patients with diabetic macular oedema (DME) and patients with choroidal neovascularization (CNV) due to age‐related macular degeneration.MethodsUncontrolled prospective observational study in 100 eyes. Retinal vessel oxygen saturation and diameters were assessed using a retinal oximeter before and minutes after IVI of ranibizumab or aflibercept.Results40 eyes with CNV and 34 eyes with DME were included in the analysis. At baseline, SO2a and SO2v were significantly higher in DME (p = 0.043 and p = 0.009, respectively). After IVI, SO2a significantly decreased in CNV and DME eyes by 2.6% (p = 0.016) and 4.6% (p = 0.002) and SO2v decreased by 14.0% (p = 0.004) and 12.4% (p = 0.017), respectively. However, a significant increase in AVD was only found in CNV (15.7%, p = 0.001). VDa decreased significantly only in DME by 5.7% (p = 0.010). No medication‐specific disease effect was found and vice versa.ConclusionsThe observed changes can be interpreted as signs of increased metabolic demand during the physiological stress after an IVI. The abnormal arterial constriction and the abolished increase in AVD seen only in eyes with DME indicate an impairment of vascular autoregulation and oxygen distribution and a reduced neuroretinal metabolism in the diabetic retina with a significant impact on inner retinal oxygen consumption shortly after IVI.

Changes in Retinal Vascular Caliber after Intravitreal Aflibercept Treatment for Diabetic Macular Oedema

Diabetic retinopathy is characterised by impaired retinal vascular autoregulation with signs of early retinal hyperperfusion and subsequent capillary drop out and peripheral ischemia. Initial retinal vascular dilation indicates disease progression and subsequent constriction signals a proliferative state. In this pilot study, we examined the effect of intravitreal aflibercept on retinal vessel diameter in patients with diabetic macular oedema. Twelve eyes of nine treatment-naive patients with diabetic macular oedema were examined during the first three months of treatment with aflibercept. The calibers of retinal arteries and veins and the central retinal arterial and vein equivalent were registered over the course of treatment. The evolution of the diabetic macular oedema was also registered and correlated to the retinal vascular caliber. During treatment, there was a significant reduction in the diameter of retinal arteries as well as in the central retinal arterial equivalent. The calibers of the retinal veins were also reduced, but not significantly. Macular oedema was significantly reduced, which however did not correlate with the vascular caliber changes. This pilot study demonstrates for the first time a possible significant reduction in retinal arterial caliber under aflibercept treatment for diabetic macular oedema. Further studies are needed to verify whether this response to intravitreal anti-VEGF treatment also signifies an improvement in retinal vascular homeostasis.

Supervised preoperative forearm exercise to increase blood vessel diameter in patients requiring an arteriovenous access for hemodialysis: rationale and design of the PINCH trial.

Failure of maturation occurs in 30%-60% of arteriovenous fistula (AVF) creation for hemodialysis, with highest rates in distal radiocephalic fistulas. This is partly due to initial small blood vessel size with limited blood flow capacity. Forearm exercise has shown potential as stimulus for increasing blood vessel size in patients with end-stage renal disease (ESRD) and may promote maturation of AVFs in the upper limb when applied postoperatively. However, it is unknown if forearm exercise increases blood vessel size pre-operatively, which may contribute to more distal AVF creation and raise success rates of AVF surgery. This study will investigate these issues. The PINCH trial (refers to 'pinching') is an investigator-initiated, multicenter, single-blinded, randomized controlled trial with 1:1 randomization to perform supervised forearm exercises compared to no exercise 6 weeks pre-operatively before creation of an AVF. Forty patients receiving an AVF will be included. The main study endpoints are blood vessel diameter (cephalic or basilic vein and radial and ulnar artery), AVF surgical plan (radiocephalic or brachiobasilic/cephalic), and three-month (assisted) maturation rate. The burden of the performed forearm exercises will be evaluated using Kidney Disease Quality of Life (KDQOL-SF Dutch version 1.2) and exercise specific questionnaires. The PINCH trial is planned to start in November 2017. Enrollment is expected to be completed at the end of 2019. The PINCH study is the first trial to evaluate the effect of pre-operative, supervised forearm exercises on vein diameter and fistula maturation in hemodialysis patients. NTR6382.

Effects of intravitreal aflibercept and ranibizumab on retinal vessel diameter measured using fluorescein angiography

PurposeTo investigate the effect of intravitreal (IVT) aflibercept and ranibizumab on retinal vessel diameter in patients with neovascular age‐related macular degeneration (N‐AMD).MethodsForty eyes of 40 consecutive participants with treatment‐naïve N‐AMD were included. Two groups of 20 eyes received three consecutive monthly treatments of IVT aflibercept or ranibizumab. Retinal vessel diameter was measured using fluorescein angiography (FA) before the first IVT injection and 1 month after the third injection. Central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) were calculated to represent average retinal vessel diameters.ResultsRetinal vessel diameter significantly decreased in aflibercept‐treated patients; CRAE and CRVE reduced from 106.7 ± 22.9 μm to 96.1 ± 24.1 μm (P = 0.028) and from 148.8 ± 19.6 μm to 140.8 ± 19.6 μm (P = 0.003), respectively. Pre‐injection and post‐injection arteriovenous ratios were 0.71 ± 0.08 and 0.71 ± 0.11, respectively (P = 0.733). However, retinal vessel diameter was not significantly reduced in ranibizumab‐treated patients; CRAE changed from 107.1 ± 23.3 μm to 104.4 ± 22.0 μm (P = 0.073) and CRVE from 139.0 ± 13.8 μm to 139.2 ± 14.2 μm (P = 0.794). Pre‐injection and post‐injection arteriovenous ratios in the ranibizumab‐treated group were 0.74 ± 0.14 and 0.72 ± 0.14, respectively (P = 0.163).ConclusionsIVT aflibercept treatment had a significant vasoconstrictive effect in eyes treated for N‐AMD; on the other hand, IVT ranibizumab did not significantly affect retinal vessel diameter. The aflibercept‐mediated reduction in diameter was not vessel‐specific.

Effects of two different doses of intravitreal bevacizumab on subfoveal choroidal thickness and retinal vessel diameter in branch retinal vein occlusion.

To investigate the effects of two different doses of intravitreal bevacizumab on subfoveal choroidal thickness (SFChT) and retinal vessel diameter in patients with branch retinal vein occlusion. An interventional, restrospective study of 41 eyes of 41 patients who had completed 12mo of follow-up, divided into group 1 (1.25 mg of bevacizumab, 21 eyes of 21 patients) and group 2 (2.5 mg of bevacizumab, 20 eyes of 21 patients). Complete ophthalmic examination, fluorescein angiography, enhanced depth imaging optical coherence tomography and measurement of retinal vessel diameter with IVAN software were performed at baseline and follow-up. The SFChT changed from 279.1 (165-431) µm at baseline to 277.0 (149-413) µm at 12mo in group 1 (P=0.086), and from 301.4 (212-483) µm to 300.3 (199-514) µm in group 2 (P=0.076). The central retinal arteriolar equivalent (CRAE) changed from 128.8±11.2 µm at baseline to 134.5±8.4 µm at 12mo in group 1, and from 134.6±9.0 µm to 131.4±12.7 µm in group 2 (P=0.767). The central retinal venular equivalent (CRVE) changed from 204.1±24.4 µm at baseline to 196.3±28.2 µm at 12mo in group 1, and from 205.8±16.3 µm to 194.8±18.2 µm in group 2 (P=0.019). The mean central macular thickness (P<0.05) and average best-corrected visual acuity (BCVA; P<0.05) improved in both groups. Changes in the SFChT are not statistically significant and not different according to the doses of bevacizumab. The CRAE did not show significant change, however, the CRVE showed significant decrease regardless of the dose.

Age-based analysis of choroidal thickness and choroidal vessel diameter in primary open-angle glaucoma.

We aimed to assess choroidal thickness and vessel diameter in patients with primary open-angle glaucoma (POAG) using enhanced depth imaging (EDI) optical coherence tomography (OCT) with age-based analysis. Fifty-four patients with a confirmed diagnosis of POAG and 44 age-sex matched healthy subjects were included into the study. A masked physician performed measurements of largest choroidal vessel diameter and choroidal thicknesses (subfoveal, nasal, and temporal) using EDI OCT. Subgroup analyses were performed to compare choroidal measurements based on age (with a cut point of 70years). The study cohort comprised 54 patients with POAG (mean age of 63.2±8.8years) and 44 healthy control subjects (mean age of 62.9±8.5years) (P=0.870). We found no significant differences in terms of choroidal measurements (P>0.05) between the glaucoma and control groups. However, in the glaucoma group, patients with an age≥70years had significantly thinner subfoveal and nasal choroid compared to those of the patients with <70years of age (P=0.017, 0.002 respectively). In the control group, choroidal thickness and vessel measurements showed no significant difference when the subjects were subgrouped according to the age cut point (P>0.05). Choroidal thickness and vessel caliber seem not to differ between patients with POAG and healthy controls. However, an age≥70years might be associated with thinning in subfoveal and nasal choroid in patients with POAG. Further studies are needed to elucidate whether choroidal thinning is a cause or result in POAG.

Variation of choroidal thickness and vessel diameter in patients with posterior non-infectious uveitis.

BackgroundChoroidal thickness (CTh) and choroidal vessel diameter (VD) in the Haler’s layer were evaluated as markers of inflammatory insult in non-infectious uveitis (NIU). Spectral-domain optical coherence tomography (Spectralis®, Heidelberg Engineering Inc.) scans were acquired from 23 normal subjects (39 eyes – group 1), 7 subjects with high myopia (14 eyes – group 2), and 19 patients with NIU (23 eyes – group 3). In groups 1 and 2, CTh and VD were measured at 3 different points of the same horizontal OCT scan passing through the fovea and a mean calculated. Mean CTh and VD were calculated in 2 other locations, 2 mm superior and inferior from the chosen foveal horizontal scan. In group 3, three measurements of CTh and VD were obtained within 1 mm of a horizontal scan passing through a retinal lesion; mean CTh and VD were then computed. A ratio (R) between the VD and the corresponding CTh was calculated.ResultsGroup 1, 2 and 3 mean age was 29.6, 29.1 and 45.9 years, respectively. Sixteen normal subjects, three myopic subjects and six NIU patients were male.. Group 1 mean CTh did not differ from group 2 (261.6±45.6 vs. 260.2±50.6 µm µm; p>0.05); mean VD was marginally higher in Group 2 (159.8±32.2 vs. 163.2±33.2 µm; p>0.05). Group 3 demonstrated thinner CTh (193.6±54.6 µm) than Groups 1 and 2 (p = 0.02 and <0.001). Group 3 mean VD (123.6±37.4 µm) was also less than that in Groups 1 and 2; the difference was statistically significant only when compared to group 2, p = 0.01. R did not differ across groups (p-values >0.05), indicating that variations in CTh and VD followed the same trend.ConclusionsThe study reports potential quantitative OCT-derived parameters that may be explored in future trials of non-infectious uveitis. Thinning of choroid and decrease of vessel diameter are observed in patients with chronic NIU compared to controls.Electronic supplementary materialThe online version of this article (doi:10.1186/s12348-014-0014-z) contains supplementary material, which is available to authorized users.

DIAMETER OF RETINAL VESSELS IN PATIENTS WITH DIABETIC MACULAR EDEMA IS NOT ALTERED BY INTRAVITREAL RANIBIZUMAB (LUCENTIS)

To investigate the effect(s) of intravitreally injected ranibizumab on retinal vessel diameter in patients with diabetic macular edema. Participants of this prospective study were 14 men and 16 women (30 eyes) aged 60 ± 11 years (mean ± standard deviation), all with clinically significant diabetic macular edema. Treatment comprised 3 intravitreal injections of ranibizumab given at 4-week intervals. Examinations were conducted before the first (baseline), before the second (Month 1), before the third (Month 2) injections, and 3 months after baseline (Month 3). Measured parameters included systemic blood pressure, static retinal vessel analysis (central retinal artery equivalent and central retinal vein equivalent), and dynamic retinal vessel analysis, as measured by the change in vessel diameter in response to flicker stimulation during three measurement cycles. Flicker stimulation was accomplished using a 50-second baseline recording, followed by an online measurement during 20-second flicker stimulation and 80-second online measurements in both arteriolar and venular vessel segments. Static retinal vessel analysis showed a reduction of central retinal artery equivalent from 186.25 ± 51.40 μm (baseline) to 173.20 ± 22.2 μm (Month 1), to 174.30 ± 27.30 μm (Month 2), and to 170.56 ± 22.89 μm (Month 3), none of which was statistically significant (P = 0.23, 0.12, and 0.14, respectively). Central retinal vein equivalent was reduced from 216.21 ± 25.0 μm (baseline) to 214.48 ± 25.4 μm (Month 1), to 214.80 ± 24.30 μm (Month 2), and to 211.41 ± 24.30 μm (Month 3), revealing no statistically significant differences between examination time points (P = 0.54, 0.06, and 0.24, respectively). Dynamic vessel analysis yielded a mean retinal arterial diameter change of +1.47% ± 2.3 (baseline), +1.91% ± 2.5 (Month 1), +1.76% ± 2.2 (Month 2), and +1.66% ± 2.1 (Month 3), none of which showed statistically significant differences (P = 0.32, 0.49, and 0.70, respectively). Mean retinal venous diameter changes were +3.15% ± 1.7 (baseline), +3.7% ± 2.3 (Month 1), +4.0% ± 2.0 (Month 2), and +4.95% ± 1.9 (Month 3), none of which showed statistically significant differences (P = 0.12, 0.17, and 0.14, respectively). Central retinal thickness, as measured by spectral domain optical coherence tomography, decreased significantly from 435.2 ± 131.8 μm (baseline) to 372.3 ± 142.8 μm (Month 3), P = 0.01. Regression analysis of arteriolar and venular diameters indicated that there was no significant correlation between these 2 parameters (r = 0.053; P = 0.835 and r = 0.06; P = 0.817, respectively). Also, no significant correlation was observed between the difference in the central retinal thickness and change in arteriolar or venular dilatation (r = 0.291, P = 0.241 and r = 0.06, P = 0.435, respectively). Intravitreally applied ranibizumab did not significantly affect retinal vessel diameter in patients with diabetic macular edema. Decline in the central foveal thickness after ranibizumab therapy, as measured by spectral domain optical coherence tomography, was not linked to any change in retinal vessel diameter or dilatatory response, neither for arterioles nor venules.

Phenylephrine 5% added to Tropicamide 0.5% eye drops does not influence retinal oxygen saturation values or retinal vessel diameter in glaucoma patients

To test whether adding topical phenylephrine 5% to tropicamide 0.5% eye drops in the protocol for pupil dilation affects the retinal vessel oximeter measurements in patients with glaucoma. To test whether phenylephrine 5% has an influence as a vasoconstrictor on the retinal vessel width and can improve the proportion of high-quality retinal images in patients with glaucoma. Retinal images of 66 patients with chronic open-angle glaucoma were obtained before and after the administration of phenylephrine 5% eye drops to patients already dilated with tropicamide 0.5% with the Oxymap Retinal Oximeter (Oxymap ehf, Reykjavik, Iceland). Specialized software, Oxymap Analyzer, analysed the images and measured the oxygen saturation and vessel diameter. Oxygen saturation was measured in first- and second-degree vessels. A Mann-Whitney U-test was used to compare both groups. Quality of the images was assessed, and a Fisher's exact test was used to compare the proportion of high- and poor-quality images. There was no significant difference in arterial and venous oxygen saturation in patients with glaucoma whether dilated by tropicamide alone or a combination of tropicamide and phenylephrine (97 ± 6% versus 96 ± 5%, p = 0.88 for arterial saturation and 66 ± 6% versus 67 ± 6%, p = 0.78 for venous saturation, n = 27). There was no significant difference in vessel diameter between both conditions for the different vessels (p = 0.61 for arterial saturation and p = 0.51 for venous saturation, n = 27). The proportion of high-quality images was significantly higher after the combination regimen compared with tropicamide only (p = 0.0001). The addition of topical phenylephrine 5% after tropicamide 0.5% improved the proportion of high-quality retinal oximetry images without influencing the retinal oxygen saturation values or the retinal vessel diameter in patients with glaucoma.

Effect of intraarterial papaverine or nimodipine on vessel diameter in patients with cerebral vasospasm after subarachnoid hemorrhage

Introduction. Papaverine (P) and nimodipine (N) are the most widely used vasodilators when angiographic and symptomatic vasospasm is present after subarachnoid aneurysmatic hemorrhage (SAH). Their effect is only short-lived and no direct comparisons have been undertaken to evaluate the action of both substances directly. We retrospectively assessed the effect of either P or N on angiographic diameter reduction and capillary blood flow. Methods. Fifteen SAH patients with secured aneurysms and cerebral vasospasm received intraarterial P, fifteen similar patients received N. As the primary endpoint, pre- and post-infusion arterial diameters and capillary blood flow were rated retrospectively on angiographies and compared by RM-ANOVA. Secondary endpoints were the difference in the modified Rankin Scale between the two groups on admission and at discharge, the occurrence of delayed cerebral ischemia, the separate effects on angiographic diameter and capillary blood flow and the overall response rate to the vasodilator infusion. Results. Angiographic resolution of diameter reduction and angiographically assessed capillary blood flow together differed not significantly between both groups. P infusion dilated all angiographic demonstrable vessels while N infusion was ineffective in 16% of the patients. Capillary flow on pre- and post-infusion angiographies was not different between the two groups. Conclusion. P and N seem to differ in the effect on cerebral diameter reduction in patients with vasospasm after SAH. The clinical implications remain to be established. A multimodal approach, perhaps combining different agents for intraarterial infusion in such patients, needs to be evaluated.

Cerebral artery restenosis following transluminal balloon angioplasty for vasospasm after subarachnoid hemorrhage.

Background:Although percutaneous transluminal angioplasty (PTA) is a widely used less invasive method to treat coronary artery stenosis, 10% of treated patients experience restenosis. Restenosis also occurs in approximately 5% of patients subjected to carotid artery stenting. Animal and human data suggested that restenosis is a response to injury incurred during PTA. As PTA has come into wide use to manage symptomatic cerebral vasospasm after subarachnoid hemorrhage (SAH) we studied the incidence of restenosis after PTA for cerebral vasospasm.Methods:Our study population consisted of 32 patients who had undergone PTA. They were followed by cerebral or 3DCT angiography or MRA for 6 126 months post-PTA (mean 48.65 months) to diagnose restenosis of the cerebral artery. We compared the size of the cerebral artery on the PTA and the contralateral side.Results:All 32 patients underwent successful PTA of 38 vascular territories and all manifested angiographic improvement of vasospasm. None suffered restenosis during the follow up period.Conclusion:PTA resulted in a significant improvement in the vessel diameter in patients with vasospasm after SAH and they did not suffer restenosis in the course of prolonged follow-up.

Influence of muscle training on resting blood flow and forearm vessel diameter in patients with chronic renal failure

Blood flow and vessel diameter are predictors of the success of vascular access procedures. This study investigated whether a simple exercise programme could influence these variables. Twenty-three patients with chronic kidney disease were prescribed a simple exercise programme for one arm only; the investigators were blinded to the patients' choice. All underwent arterial and venous duplex imaging, handgrip strength and blood pressure measurements before and 1 month after the exercise programme. Twelve patients exercised their dominant and 11 their non-dominant arm. In the trained arm, the exercise programme resulted in a significant increase in handgrip strength, by a median (interquartile range) of 4 (0-8) kg (P < 0.001), and in the diameter of the brachial artery (0.2 (0.1-0.3) mm; P < 0.001), radial artery (0.3 (0.2-0.4) mm; P < 0.001), and cephalic vein (0.6 (0.4-1.2) mm in the forearm and 1.1 (0.4-1.2) mm above the elbow; P < 0.001). There was an increase in brachial artery mean velocity (3 (1-7) cm/s; P = 0.009) and peak systolic velocity (8 (1-15) cm/s; P = 0.020), despite a marginally lower systolic blood pressure (-8 (-16 to 0) mmHg; P = 0.007). There was no change in any of these parameters in the non-exercised arm. In patients with chronic kidney disease, forearm exercise increased blood flow and vessel diameters. This may be beneficial before vascular access formation.

ANGIOGRAPHIC AND HEMODYNAMIC EFFECT OF HIGH CONCENTRATION OF INTRA-ARTERIAL NICARDIPINE IN CEREBRAL VASOSPASM

Nicardipine has been used to treat cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage. Intra-arterial (IA) infusion of high concentrations of nicardipine decreases procedure time, but it may affect hemodynamic parameters. In addition, a quantitative measurement of improvement of vessel diameter on the angiograms has not been performed. We conducted a single-center, retrospective database analysis of consecutive patients with symptomatic vasospasm after aneurysmal subarachnoid hemorrhage who failed medical management and received IA nicardipine between September 2005 and June 2006. Nicardipine (1 mg/mL/min) was infused intra-arterially by microcatheter. Blood pressure, heart rate, and intracranial pressure were recorded during the infusion. The effect of IA nicardipine on the vessel's diameter was measured on angiography by two blinded investigators. Forty-six treatment sessions were performed in 22 consecutive patients (13 women; age, 56.4 +/-13 years). Fourteen patients received IA nicardipine alone, and 8 patients had additional angioplasty. The average nicardipine dose was 12 +/- 10 mg (range, 2-25 mg). The mean decrease of systolic, diastolic, and mean blood pressure was 17.4 +/- 18.3 mm Hg, 7.7 +/- 10.4 mm Hg, and 10.9 +/- 11.6 mm Hg, respectively. There was no change in intracranial pressure. Measurement of 49 vessels in the 14 patients treated with nicardipine alone showed a significant increase in arterial diameters (range, 1-74%; P < 0.0001). At the time of discharge, 11 patients (50%) were functionally independent (modified Rankin Scale score, 0-2). High concentrations of IA nicardipine infusion have a reversible effect on blood pressure and heart rate. IA nicardipine results also in a significant improvement in vessel diameter in patients with vasospasm after aneurysmal subarachnoid hemorrhage.

Effects of cilostazol in patients with Raynaud's syndrome

Raynaud's syndrome (RS), which is characterized by recurrent episodes of vasospasm with exposure to cold, may occur alone (primary RS) or in association with connective tissue diseases or other underlying conditions (secondary RS). We investigated the effect of cilostazol on vessel wall responses in RS. Patients were diagnosed (primary or secondary RS associated with connective tissue diseases) and randomized to placebo or cilostazol 100 mg twice daily for 6 weeks in a double-blind manner. Brachial artery vasoreactivity, laser Doppler fluxmetry, and cold pressor testing (CPT) were performed at study initiation and completion. Symptoms were assessed using standardized questionnaires. Forty subjects completed the study (19 with primary RS and 21 with secondary RS). Cilostazol significantly increased the mean brachial artery diameter at 6 weeks (primary RS, p = 0.006; secondary RS, p = 0.06). There was no change in median flow-mediated dilation (FMD) with cilostazol in primary RS (25th, 75th percentiles) (4.06% [2.5, 6.1] to −0.77% [−2.4, 3.4] or secondary RS (2.2% [0.05, 6.3] to 2.95% [1.7, 7.4]). There were no changes in nitroglycerin-mediated dilation or microvascular flow indexes in either cohort. In patients with primary RS, cilostazol treatment yielded a positive change in the slope of brachial responsiveness to CPT (increase of 0.32 mm/min; p = 0.002 vs placebo). Cilostazol treatment remained significantly associated with increased brachial artery diameter when controlling for baseline values (p = 0.018). Cilostazol increased conduit vessel diameter in patients with primary and secondary RS, with a favorable impact on conduit vessel responsiveness to cold in patients with primary RS without affecting microvascular flow or symptoms.

Implications of small reference vessel diameter in patients undergoing percutaneous coronary revascularization

OBJECTIVESThe purpose of this study was to determine whether small reference diameter of the culprit coronary artery influences the outcome of an attempted percutaneous revascularization procedure in the current era of interventional cardiology.BACKGROUNDAlthough the interventional strategy is largely determined by the size of the culprit coronary artery, earlier quantitative studies have not shown a worse acute outcome for small reference vessel diameter (≤2.5 mm).METHODSA total of 2,306 patients undergoing percutaneous coronary revascularization was divided in groups with reference diameters ≤2.5 mm (n = 813) or >2.5 mm (n = 1,493). Success and in-hospital major adverse cardiac event (death, Q-wave myocardial infarction and emergency coronary artery bypass graft) rates between both groups were compared.RESULTSPatients with lesions in small vessels were older and presented more frequently with female gender, diabetes mellitus, heart failure, peripheral vascular, multivessel coronary disease and American Heart Association/American College of Cardiology (AHA/ACC) lesion type C (p ≤ 0.01, each). Further, utilization of interventional devices differed markedly. In contrast to stents (18.5% vs. 41.9%) and directional atherectomy (3.7% vs. 13.5%), conventional balloon angioplasty (73% vs. 50%) and rotational atherectomy (16.1% vs. 8.3%) were used more often in smaller vessels (p ≤ 0.0001, each). Success rate was lower in the small vessel group (92% vs. 95%; p = 0.006). Major adverse cardiac events occurred more frequently in small than large vessels (univariate 3.4% vs. 2.0%, p = 0.03; multivariate odds ratio 2.1, p = 0.02), particularly when proximal coronary segments were compared.CONCLUSIONSLesions in vessels with small reference diameter represent a distinct group with respect to clinical and morphologic characteristics as well as device utilization. These lesions have lower chances of successful percutaneous intervention and carry relatively higher risks, specifically when located in proximal coronary segments.