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Patency Rate (patency + rate)
Kinds of Patency Rate Selected AbstractsTreatment of long ureteric strictures with buccal mucosal graftsBJU INTERNATIONAL, Issue 10 2010Darko Kroepfl Study Type , Therapy (case series) Level of Evidence 4 OBJECTIVE To describe the reconstruction of long ureteric strictures using buccal mucosal patch grafts and to report the intermediate-term functional outcome. PATIENTS AND METHODS Between November 2000 and October 2006 reconstruction of seven long ureteric strictures using buccal mucosal patch grafts and omental wrapping was performed in five women (one with bilateral strictures) and one man. The surgical steps of stricture reconstruction and wrapping with omentum are described in detail. Stricture recurrence was defined as persistent impaired ureteric drainage as displayed by imaging techniques or the necessity to prolong JJ stenting. Patency rates and stricture recurrence-free survival rates are provided. RESULTS With a median follow up of 18 months five of the seven strictures were recurrence-free. Graft take was good in all patients. In one asymptomatic patient, there was impaired ureteric drainage on the reconstructed side, and in one patient with reconstruction of both ureters prolonged JJ stenting of one side was necessary. In both patients, the impaired drainage was caused by persistent stricture below the reconstructed ureteric segments. CONCLUSIONS At intermediate-term follow-up in a small group of patients with long ureteric strictures, treatment with buccal mucosal patch grafts and omental wrapping showed good functional outcome. [source] Intima-media thickness of radial artery is associated with early access failure in hemodialysis patientsHEMODIALYSIS INTERNATIONAL, Issue 1 2005Y.O. Kim Objective:,We have reported that intimal hyperplasia, which is the pathologic change of the radial artery, is associated with early failure of arteriovenous fistula (AVF) in hemodialysis (HD) patients (Am J Kidney Dis, 41:422,428, 2003). Intima-media thickness (IMT), which represents the whole thickness of arterial wall, can be easily measured by ultrasonography, unlike intima thickness. This study was performed to investigate the impact of IMT of radial artery on early failure of AVF in HD patients. Methods:,Ninety HD patients undergoing radiocephalic AVF operation were included in this study. The AVF was constructed in an end vein,to,side artery fashion at the wrist by one vascular surgeon. During the operation, 10-mm long partial arterial walls were removed with elliptical form for microscopic analysis. Specimens were stained with trichrome and examined by a pathologist blinded to the clinical data. AVF patency was prospectively followed up for 1 year after the operation. Results:,Mean age of the patients was 56 ± 13 years and the number of females was 44 (48.9%). Mean IMT was 430 ± 132 ,m (133,760 ,m). Of the total 90 patients, 31 patients (34.4%) had AVF failure within 1 year after the operation. Mean IMT was higher in the failed group (n = 31) than in patent group (n = 59)(486 ± 130 ,m vs. 330 ± 178 ,m, p = 0.004). Using a threshold of 500 ,m of IMT, AVF patency rate was compared between these two groups using Kaplan-Meier method with log rank test. The AVF patency rate within 1 year after the operation was higher in patients with IMT , 500 ,m (n = 26) than in patients with IMT < 500 ,m (n = 64)(p < 0.001). The patients with IMT , 500 ,m were older and had higher incidence of diabetes mellitus, compared to the patients with IMT < 500 ,m. There was no difference in sex, smoking, hypertension, total cholesterol and albumin levels between the two groups. Conclusion:,Our data suggest that increased intima-media thickness of radial artery is associated with early failure of radiocephalic arteriovenous fistula in hemodialysis patients. [source] Microsurgical vasoepididymostomy with sperm cryopreservation for future assisted reproductionINTERNATIONAL JOURNAL OF UROLOGY, Issue 12 2000Hatsuki Hibi Abstract Background Although obstructive azoospermia is treatable with microscopic seminal reconstruction, the number of patients who choose to undergo vasoepididymostomy is limited because of recent advances in assisted reproductive technology (ART). We attempted to define the outcome of surgical reconstruction in patients with suspected epididymal obstruction and no previous history of vasectomy. Methods We described 40 eligible end-to-side vasoepididymostomy procedures performed on 24 azoospermic patients who had either bilateral or unilateral epididymal obstruction. Results The overall patency rate following surgery was 54% (13/24) and for four patients (17%), natural intercourse resulted in pregnancy. Two pregnancies were initiated with intracytoplasmic sperm injections using frozen sperm collected during vasoepididymostomy. Conclusions In the era of modern ART, microsurgical vasoepididymostomy with cryopreservation of sperm collected during the operation is recommended for patients with epididymal obstructions. [source] The Blalock-Taussig ShuntJOURNAL OF CARDIAC SURGERY, Issue 2 2009Shi-Min Yuan M.D. This warrants us a zest in making a comprehensive survey on this subject. Methods: Articles were extensively retrieved from the MEDLINE database of National Library of Medicine USA if the abstract contained information relevant to the B-T shunt in terms of the conduit options, modified surgical techniques, surgical indications, short- and long-term results, complications, and prognosis. Further retrieval was undertaken by manually searching the reference list of relevant papers. Results: Classical or modified B-T shunts, either on ipsilateral or contralateral side to the aortic arch, can be performed on patients of any age with minimum postoperative complications and low operative mortality. Expended polytetrafluoroethylene has gained satisfactory long-term patency rate in the construction of the modified B-T shunt. Excellent pulmonary artery growth was observed in the patients with a modified B-T shunt, and it has shown superb prognosis over the classic with regard to hemodynamics, patency rate, and survival. Conclusions: The modified B-T shunt that was developed on basis of the classic fashion remains the preferable palliative procedure aiming at enhancing pulmonary blood flow for neonates and infants with complicated cyanotic congenital heart defects. The modified B-T shunt is technically simpler with less dissection, and blood flow to the respective arm is not jeopardized. It has been proved to be of low risk, excellent palliation, and is associated with excellent pulmonary artery growth, has become the most effective palliative shunt procedure of today. [source] Does Mediastinitis Affect the Graft Patency?JOURNAL OF CARDIAC SURGERY, Issue 3 2005Denyan Mansuro, lu M.D. There are many studies that have focused on the graft patency. But, till now, no study has been done to detect the effects of mediastinitis to graft patency. So, we aimed to detect the effect of mediastinitis on the graft patency in patients who have undergone coronary artery bypass surgery. Sixteen of 45 patients who have been operated upon for coronary artery bypass surgery and developed mediastinitis, which was treated with open drainage and mediastinal irrigation with late wound closure, were included in the study. The mean age of the patients was 55 ± 11 (range 35,69) and nine of the patients were male. The graft patency was evaluated with control coronary angiographies after a mean period of 30.42 ± 43.17 months (range 1,132). The left internal thoracic artery was patent in all patients (100%). Right internal thoracic artery patency rate was 50% (1/2). One individual bypassed radial artery was patent, whereas the sequential bypassed graft was occluded. The patency ratio of radial artery anastomosis was 33% (1/3). Twelve of the 17 saphenous vein grafts were patent (70.58%). The total number of patent distal anastomosis was 30/38 (78.94%). When compared with the graft patency of patients without infection, it was found that mediastinitis does not affect the graft patency rates adversely. [source] Cryopreserved iliac artery is indispensable interposition graft material for middle hepatic vein reconstruction of right liver graftsLIVER TRANSPLANTATION, Issue 6 2005Shin Hwang Cryopreserved iliac vein grafts (IVGs) have often been used for reconstruction of middle hepatic vein (MHV) branches in right liver grafts, but their storage pool has often been exhausted in our institution due to the low incidence of deceased donor organ procurement. To overcome this shortage of IVG, we started to use cryopreserved iliac artery graft (IAG). During September and October 2004, we carried out 41 cases of adult living donor liver transplantation, including 29 right lobe grafts with MHV reconstruction. Interposition vessel grafts were autologous vein (n = 6), IVG (n = 13), and IAG (n = 10). IAG was used in 3 (21%) of 13 cases during the first month. For the next month, it was more frequently used (7 [44%] of 16) because handling of cryopreserved IAG was not difficult and its outcome was favorable. On follow-up with computed tomography for 3 months, outflow disturbance occurred in 1 (17%) of 6 autologous vein cases, in 2 (15%) of 13 IVG cases, and in 1 (10%) of 10 IAG cases. Two-month patency rate of IAG was not lower than that of IVG. In conclusion, we feel that cryopreserved IAG can be used as an interposition vessel graft for MHV reconstruction of right liver graft when cryopreserved IVG is not available. (Liver Transpl 2005;11:644,649.) [source] Training program and learning curve in experimental microsurgery during the residency in plastic surgeryMICROSURGERY, Issue 4 2007Ioan Lascar M.D., Ph.D. This article presents a comparison of microsurgical training of groups with different background. A protocol based on the rat femoral arterial anastomoses was used to provide an objective representation of the microsurgical skills progress. The performance is assessed by consistent (×4) patency of a standardized anastomosis. Three groups of beginner residents with progressive microsurgical experience and one group of experienced surgeons were observed. The patency curve of the beginner-groups was as an abrupt learning curve, and then a plateau was reached. There was no statistically significant difference in the patency rate between the beginner-groups after their first 32 anastomoses. No statistically significant difference was noted when the patency of the advanced group was compared with beginner-groups after different numbers of anastomoses (inverse proportional with their training experience). A slight or a plateau learning curve was found among the experienced group. The learning curve is a useful adjunct in the assessment of training. © 2007 Wiley-Liss, Inc. Microsurgery 2007. [source] Long-term frontal sinus patency after endoscopic frontal sinusotomy,THE LARYNGOSCOPE, Issue 6 2009Yvonne Chan MD Abstract Background: The frontal recess is the drainage pathway that connects the frontal sinus to the anterior ethmoid sinus. Mechanical obstruction is the primary cause of chronic frontal sinusitis with or without a secondary inflammatory process. Eosinophilic inflammation is one of the underlying causes for chronic rhinosinusitis. Objectives/Hyphothesis: To evaluate long-term frontal sinus patency after endoscopic frontal sinusotomy in chronic rhinosinusitis patients and to assess the effect of eosinophilic inflammation on frontal sinus patency. Study Design: Retrospective chart review. Symptom assessment and archived endoscopic photographs were prospectively collected on patients who underwent frontal sinusotomy between 7-1-1999 and 12-31-2000. Subjective symptom improvements were evaluated using the SNOT-20 = 20-item Sino-Nasal Outcome Test. Objective findings of endoscopic frontal sinus patency were documented by archived digital photography. Results: A total of 161 patients with 294 frontal sinuses who underwent endoscopic frontal sinus surgery in the 18 months had an average follow-up of 45.9 months. The patient population was divided into two groups: 58 patients had eosinophilic CRS (ECRS), and 103 patients had CRS without eosinophils (non-ECRS). The mean follow-up for patients with ECRS is 61.6 months and 37.0 months for non-ECRS patients. The non-ECRS patients had a documented endoscopic frontal sinus patency of 90%, and the ECRS patients had an endoscopic frontal sinus patency of 85%. The overall frontal ostium patency rate for all patients was 88.0%. Conclusions: Long-term endoscopic confirmation of frontal ostium patency demonstrates that endoscopic frontal sinusotomy can yield high quality, durable results. There was no significant difference in patency results between ECRS and non-ECRS patients. Laryngoscope, 2009 [source] Long-Term Results after Endoscopic Sinus Surgery Involving Frontal Recess DissectionTHE LARYNGOSCOPE, Issue 4 2006Michael Friedman MD Abstract Objective: To assess long-term follow-up on a cohort of patients who underwent endoscopic frontal sinus surgery with identification and preservation of the natural frontal outflow tract. Study Design and Settings: Retrospective chart review, telephone interview, and endoscopic evaluation on a previously studied cohort of patients at a university affiliated medical center. Results: Two hundred patients who underwent endoscopic frontal sinus surgery were previously studied and reported after short-term (mean = 12.2 mo) follow-up. One hundred fifty-two (76%) patients were available for long-term (mean 72.3 mo) follow-up and assessment of subjective symptoms. Fifty-seven of 152 (37.5%) patients also had nasal endoscopy for evaluation of objective findings. The percentage of patients responding to telephone interview reporting overall improvement after surgery was 92.4%. Endoscopic assessment revealed patency of the frontal sinus in 67.6% of the patients after initial surgery. Thirteen additional patients had patent sinuses after revision procedures, bringing overall patency rate to 71.1%. We found statistically significant correlation of asthma and smoking and poor subjective and objective outcome. Conclusion: Long-term assessment of subjective and objective findings in our previously reported cohort of patients who underwent frontal sinus surgery indicates that the frontal sinus, similar to any other sinus, can be successfully treated surgically by preserving the natural frontal sinus outflow tract. [source] Experimental Evaluation of a New Antithrombogenic Stent Using Ion Beam Surface ModificationARTIFICIAL ORGANS, Issue 6 2009Yoichi Sugita Abstract A new antithrombogenic stent using ion beam surface modification nanotechnology was evaluated. The ion stent is being developed to inhibit acute and chronic stent-related thrombosis. Thirty self-expanding mesh stents were fabricated from Ti-Ni metal wires with a dimension of 4 mm (diameter) × 25 mm (length) × 0.15 mm (thickness). Twenty stents were coated with type I collagen and irradiated with a He+ ion beam at an energy of 150 keV with fluences of 1 × 1014 ions/cm2 (ion stent group). Ten stents had no treatment (non-ion stent group). The self-expanding stents were implanted into the right and left peripheral femoral arteries of 15 beagle dogs (vessel diameter approximately 3 mm) via a 6Fr catheter under fluoroscopic guidance. Heparin (100 units/kg) was administered intravenously before implantation. Following stent implantation, no antiplatelet or anticoagulant drugs were administered. The 1-month patency rate for the non-ion stent group was 10% (1/10), and for the ion stent group it was 80% (16/20) with no anticoagulant or antiplatelet drugs given after stent implantation (P = 0.0004 by Fisher's exact test). Ten stents remain patent after 2 years in vivo with no anticoagulant or antiplatelet drugs. These results indicate that He+ ion-implanted collagen-coated Ti-Ni self-expanding stents have excellent antithrombogenicity and biocompatibility. This ion stent is promising for coronary and cerebral stent applications. [source] Development and Validation of Small-diameter Vascular Tissue From a Decellularized Scaffold Coated With Heparin and Vascular Endothelial Growth FactorARTIFICIAL ORGANS, Issue 3 2009Min Zhou Abstract To overcome shortcomings of current small-diameter vascular prostheses, we developed a novel allogenic vascular graft from a decellularized scaffold modified through heparin immobilization and vascular endothelial growth factor (VEGF) coating. The VEGF coating and release profiles were assayed by enzyme-linked immunosorbent assay, the biological activity of modified surface was validated by human umbilical vein endothelial cells seeding and proliferation for 10 days in vitro. In vivo, we implanted either a modified or a nonmodified scaffold as bilateral carotid allogenic graft in canines (n = 15). The morphological examination of decellularized scaffolds showed complete removal of cellular components while the extracellular matrix structure remained intact. After modification, the scaffolds possessed local sustained release of VEGF up to 20 days, on which the cells cultured showed significantly higher proliferation rate throughout the time after incubation compared with the cells cultured on nonmodified scaffolds (P < 0.0001). After 6 months of implantation, the luminal surfaces of modified scaffolds exhibited complete endothelium regeneration, however, only a few disorderly cells and thrombosis overlay the luminal surfaces of nonmodified scaffolds. Specifically, the modified scaffolds exhibited significantly smaller hyperplastic neointima area compared with the nonmodified, not only at midportion (0.56 ± 0.07 vs. 2.04 ± 0.12 mm2, P < 0.0001), but also at anastomotic sites (1.76 ± 0.12 vs. 3.67 ± 0.20 mm2, P < 0.0001). Moreover, modified scaffolds had a significantly higher patency rate than the nonmodified after 6 months of implantation (14/15 vs. 7/15, P = 0.005). Overall, this modified decellularized scaffold provides a promising direction for fabrication of small-diameter vascular grafts. [source] Late Results of Gelatin,Resorcin,Formalin Glue-aided Repair in Acute Type A Aortic DissectionARTIFICIAL ORGANS, Issue 12 2006Motomi Shiono Abstract:, Gelatin,resorcin,formalin (GRF) glue has been used to obliterate the false lumen of dissected aortas, resulting in reduced mortality. However, because of the cytotoxicity of formalin, the application of GRF remains controversial. In this study, a total of 138 consecutive patients with acute type A dissection since 1995, who underwent emergency graft replacement, were reviewed. The mean age was 65.5 years. The hospital mortality rate was 6.5%. In-hospital re-exploration rate and patency rate of the false lumen were 6.5% and 24.7%, respectively. The actuarial survival rates were 81.5% after 5 years and 54.8% after 10 years. Reoperation-free rates were 87.9% after 5 years and 72.3% after 10 years. Tissue necrosis or aneurismal degeneration was not demonstrated at reoperation. In conclusion, GRF glue demonstrats excellent tissue adhesion and hemostasis capability, and contributes to improve surgical results. [source] Computational Fluid Dynamics and Vascular AccessARTIFICIAL ORGANS, Issue 7 2002Ulf Krueger Abstract: Anastomotic intimal hyperplasia caused by unphysiological hemodynamics is generally accepted as a reason for dialysis access graft occlusion. Optimizing the venous anastomosis can improve the patency rate of arteriovenous grafts. The purpose of this study was to examine, evaluate, and characterize the local hemodynamics and, in particular, the wall shear stresses in conventional venous end-to-side anastomosis and in patch form anastomosis (Venaflo) by three-dimensional computational fluid dynamics (CFD). We investigated the conventional form of end-to-side anastomosis and a new patch form by numerical simulation of blood flow. The numerical simulation was done with a finite volume-based algorithm. The anastomotic forms were constructed with usual size and fixed walls. Subdividing the flow domain into multiple control volumes solved the fundamental equations. The boundary conditions were identical for both forms. The velocity profile of the patch form is better than that for the conventional form. The region of high static pressure caused by flow stagnation is reduced on the vein floor. The anastomotic wall shear stress is decreased. The results of this study strongly support patch form use to reduce the incidence of intimal hyperplasia and venous anastomotic stenoses. [source] Intravasal azoospermia: a surgical dilemmaBJU INTERNATIONAL, Issue 9 2000Y.R. Sheynkin Objectives,To determine the incidence of intravasal azoospermia (IVA) and evaluate which factors before and during surgery influence outcome, by prospectively and intentionally performing bilateral vasovasostomies (VVs) only in men with intraoperative IVA. Patients and methods,Using a multilayer technique, 472 men underwent microsurgical reconstructive procedures. Intravasal fluid was examined for sperm by the surgeon and a pathologist. Strict enrolment criteria included total absence of sperm or sperm parts and bilateral VV as a treatment procedure. Patients were followed up by semen analysis and paternity assessed only by naturally conceived pregnancies. Results,Of the 472 patients, 27 (5.7%) had bilateral IVA; 15 of these patients were available for a follow-up of 1,47 months. Eleven patients had identical gross appearance of intravasal fluid bilaterally. Of these patients, five had sperm in the ejaculate after surgery (three with clear intravasal fluid and two with no fluid). Bilaterally different vasal fluid was found in four men. Unilateral clear fluid was present in three patients, two of whom had sperm in semen analysed after VV. Overall, there was sperm in the ejaculate in seven of 15 patients with IVA; five of these seven had clear fluid in at least one vas deferens. One patient with unilaterally clear fluid achieved paternity by a naturally conceived pregnancy. The difference between the mean (sem) obstruction interval in men who had sperm in a semen sample after VV, at 16.7 (3.30) years, and in persistently azoospermic patients, at 15.5 (1.89) years, was not statistically significant (P = 0.741). Conclusion,The results of VV in patients with IVA are unsatisfactory; the patency rate is higher in men with copious clear fluid in at least one vas. The obstructive interval in patients with IVA does not appear to influence the outcome of VV. [source] Selective use of ultrasonographic vascular mapping in the assessment of patients before haemodialysis access surgeryBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 11 2005A. C. Wells Background: Use of routine preoperative ultrasonography to determine the optimum site for haemodialysis access surgery increases the number of distal arteriovenous fistulas formed and improves overall patency rates. Nevertheless its use in all patients is time consuming and costly. This study examined whether clinical parameters could be used to determine the requirement for preoperative ultrasonography. Methods: Between March 2002 and October 2003, 145 consecutive patients were reviewed in the vascular access clinic. Patients were first assessed clinically, a site for vascular access surgery was proposed, and the need for radiological mapping studies recorded. A second, blinded, clinician determined the site for vascular access surgery using ultrasonography. The correlation between clinical and ultrasonographic findings was then examined. Results: Ultrasonography was considered unnecessary using clinical criteria in 106 patients. Subsequent ultrasonographic mapping altered the management of only one patient. In contrast, the management of 18 of the 39 patients in whom ultrasonography was thought necessary was influenced by radiological imaging. A 1-year primary patency rate of 77·0 per cent was achieved following vascular access surgery on the study population. Conclusion: Clinical parameters could be used to determine the need for preoperative vascular ultrasonographic mapping; imaging was not required in the majority of patients. Copyright © 2005 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] Impact of angioplasty on infrainguinal bypass for critical ischaemia of the legBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 4 2001D. Evoy Background: Both angioplasty and infrainguinal bypass procedures may be used to achieve limb salvage in patients with critical ischaemia. The authors investigated the effect of the introduction of angioplasty on the frequency with which infrainguinal bypass was performed and, second, the changes in outcome of infrainguinal bypass following the introduction of angioplasty. Methods: All patients had critical ischaemia of the leg. Three patient groups were studied: 215 patients undergoing infrainguinal bypass before the introduction of angioplasty (1986,1991), 216 patients who had infrainguinal bypass after the introduction of angioplasty (1993,1998) and 193 patients undergoing angioplasty in the same 5-year interval (1993,1998). Results: The age and risk profile of the three groups was identical. The overall caseload increased by 19 per cent following the introduction of angioplasty. Primary and secondary patency rates were superior for bypass compared with angioplasty, but were similar for the two bypass groups (5-year primary patency rate 60 per cent versus 18-month primary patency rate 45 per cent; 5-year secondary patency rate 80 per cent versus 18-month secondary patency rate 60 per cent). By 18 months 26 per cent of patients having angioplasty had gone on to have bypass. The limb salvage rate of 90 per cent at 1 year was similar for all groups. Survival was significantly higher in the group of patients undergoing bypass from 1993 to 1998 compared with the other two groups (80 versus 60 per cent; P < 0·0002). Conclusion: The introduction of angioplasty has increased overall workload. Angioplasty has a lower patency rate than bypass but a comparable limb salvage rate, making it a suitable alternative to bypass in the management of patients with critical ischaemia. © 2001 British Journal of Surgery Society Ltd [source] Contribution of Nitric Oxide Synthase to Improved Early Graft Patency in Human Saphenous Vein Graft Harvested by a Novel ,No-Touch' TechniqueJOURNAL OF CARDIAC SURGERY, Issue 6 2002JCS Tsui Aim: Saphenous vein (SV) is the most commonly used conduit in bypass procedures but has a one-year occlusion rate of 15-30%. A new ,no-touch' technique where the SV is harvested with a cushion of surrounding tissue with no distension has led to improved early patency rates of 5% at 18-months. Nitric oxide (NO), synthesised by nitric oxide synthase (NOS) has properties beneficial to graft patency. Our aim was to study the distribution of NOS in SV harvested by this technique and the effect of distension and removal of perivascular tissue on NOS content of SV. Methods: Following ethical committee approval and patients' informed consent, SVs were harvested from ten patients undergoing coronary artery bypass grafting. A segment of vein was harvested by the conventional technique (surrounding tissue stripped and vein distended with saline); another part was stripped but not distended (,control') and the remaining parts harvested by the ,no-touch' technique. Samples of each segment were taken and transverse sections prepared for NOS identification using 3[H]L-NG nitroarginine (NO Arg) autoradiography and NADPH-diaphorase histochemistry. NOS isoforms were studied using standard immunohistochemistry. Endothelial cells and nerves were also identified using immunohistochemistry with CD31 and NF200 respecitvely, to confirm sources of NOS. Morphometric analysis of NADPH-diaphorase staining was carried out to study tissue NOS content. Results: NO Arg binding representing NOS was preserved on the lumen of ,no-touch' vessels whilst that on conventional and control vessels was reduced. NOS was also localised to the medial smooth muscle cells of all vein segments and to the intact adventitia of ,no-touch' segments. This was confirmed by NADPH-diaphorase staining, which revealed a mean reduction of NOS by 19.5% (p < 0.05, ANOVA) in control segments due to stripping of surrounding tissue alone and a reduction of 35.5% (p < 0.01, AVNOVA) in conventional segments due to stripping and distension, compared to ,no-touch' segments. Adventitial NOS sources in ,no-touch' vessels corresponded to vasa vasorum and paravascular nerves. All three NOS isoforms contributed to the preserved NOS in ,no-touch' vessels. Conclusions: Apart from preserved lumenal NOS, NOS sources are also located in the media and adventitia of SV grafts. These are reduced by both adventitial damage and vein distension during conventional vein harvesting. The ,no-touch' technique avoids these procedures, preserving NOS sources. This may result in improved NO availability in SV harvested by this technique, contributing to the improved patency rates reported. [source] Comparison study of Doppler ultrasound surveillance of expanded polytetrafluoroethylene-covered stent versus bare stent in transjugular intrahepatic portosystemic shuntJOURNAL OF CLINICAL ULTRASOUND, Issue 7 2010Qian Huang MD Abstract Objective. This prospectively randomized controlled study aimed to assess with Doppler ultrasound (US) the shunt function of expanded polytetrafluoroethylene (ePTFE)-covered transjugular intrahepatic portosystemic shunt (TIPS) stent versus bare stent and to evaluate the usefulness of routine TIPS follow-up of ePTFE-covered stents. Methods. Sixty consecutive patients were randomized for bare or covered transjugular TIPS stenting in our institution between April 2007 and April 2009. Data of follow-up Doppler US, angiography, and portosystemic pressure gradient measurements were collected and analyzed. Results. The follow-up period was 8.34 ± 4.42 months in the bare-stent group and 6.16 ± 3.89 months in the covered-stent group. Baseline clinical characteristics were similar in both groups. Two hundred three US studies were performed in 60 patients, with a mean of 3.4 per patient, and demonstrated abnormalities in 28 patients (21 bare stents, 7 ePTFE-covered stents), 19 of them (13 in bare-stent group, 6 in covered-stent group) showing no clinical evidence of recurrence. Ten of 13 patients in the bare-stent group underwent balloon angioplasty or additional stent placement, whereas only one of six patients in the covered-stent group needed reintervention for intimal hyperplasia. The average peak velocity in the midshunt of ePTFE-covered stent was 139 ± 26 cm/s after TIPS creation and 125 ± 20 cm/s during follow-up, which was significantly higher than the bare-stent group (p < 0.05). The main portal vein and hepatic artery showed higher flow velocities in the ePTFE-covered stent group than in the bare-stent group. ePTFE-covered stents maintained lower portosystemic pressure gradient than bare stents (9.5 ± 2.9 versus 13.2 ± 1.5 mmHg, p < 0.05). Conclusions. ePTFE-covered stents resulted in higher patency rates and better hemodynamics than bare stents. Routine US surveillance may not be necessary in patients with ePTFE-covered TIPS stent. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound 38:353-360, 2010 [source] Endovascular Interventions in Iliac and Infrainguinal Occlusive Artery DiseaseJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 6 2004JOHANNES RUEF M.D., M.Sc. Percutaneous endovascular procedures are increasingly applied to treat symptomatic peripheral occlusive artery disease. While the primary technical success and recanalization rates in iliac and infrainguinal interventions are high, differences in the long-term patency rates exist with respect to the anatomic localization, separating the iliac, femoropopliteal, and infrapopliteal arterial regions. In iliac arteries, even complex lesions can be recanalized with good long-term patency rates, especially when using self-expanding nitinol stents. In the infrainguinal arteries the method of choice is still under debate (e.g., balloon angioplasty vs stent implantation). A high restenosis rate represents one of the major limitations in femoropopliteal and infrapopliteal interventions. Therefore, additional methods and treatment strategies for peripheral interventions with the potential for future applications are under investigation and will be discussed such as drug-eluting stents, brachytherapy, subintimal angioplasty, laser angioplasty, atherectomy/thrombectomy, cutting balloon, polytetrafluoroethylene (PTFE)-covered stent grafts, biodegradable stents, and cryoplasty. The increasing amount of data on successful peripheral interventions supports the necessity to adapt and reevaluate the current consensus guidelines that were put together in 2000. [source] The natural history of parallel transjugular intrahepatic portosystemic stent shunts using uncovered stent: the role of host-related factorsLIVER INTERNATIONAL, Issue 5 2006Ahmed Helmy Abstract: Objectives: Parallel shunts (PS) are used in the management of transjugular intrahepatic portosystemic stent-shunt (TIPS) insufficiency, a major limitation of the technique. This study describes the natural history of PS, and uses them as a model to assess the role of host factors in the development of primary shunt insufficiency. Methods: Out of 338 patients with TIPS, 40 (11.8%) patients required insertion of a PS. Baseline and follow-up data of these patients were collected. Regular shunt surveillance involved biannual clinic visits and transjugular portography. Results: The non-PS group (group 1; n=298) and the PS group (group 2; n=40) had similar baseline demographic and disease characteristics. Index shunts of both groups and the PS produced a significant portal pressure gradient drop (P<0.001), which was less in the index shunts of Group 2 (P<0.02 for both). PS had similar cumulative shunt patency rates to those of the index shunts of Group 1, and both were greater than those of index shunts in Group 2 (P<0.001 for both). The intervention rate (number of interventions/number of check portograms × 100) was similar for PS and the index shunts of Group 1 (38.7% and 43% respectively), but was significantly higher in the index shunts of Group 2 (85.6%; P<0.01 for both). In Group 1 and Group 2, 144 patients (48.3%) and 21 patients (52.5%) died during follow-up after a median period of 23.4 and 8.9 months respectively. Conclusions: These findings do not support the hypothesis that shunt insufficiency is related to host factors. [source] Transjugular intrahepatic portosystemic shunt: an analysis of outcomesANZ JOURNAL OF SURGERY, Issue 10 2009Timothy P. Kurmis Abstract Background:, Transjugular intrahepatic portosystemic shunts (TIPS) are utilized for the management of complications of portal hypertension, particularly diuretic-resistant ascites and recurrent variceal bleeding. It has also been applied in Budd,Chiari syndrome and hepatorenal syndrome. We report the results in a small series, over 9 years, from a single centre, and compare these to those published in the literature. Methods:, A retrospective case note review of 20 consecutive TIPS procedures performed at Flinders Medical Centre from January 1997 to December 2005 was completed. All indications were included in the analysis. Underlying liver disease, peri-procedure complications, relief of symptoms and patient survival were recorded. Data on type of TIPS, shunt patency and method of follow-up were recorded. Results:, Thirty-six TIPS were performed in 20 subjects. All initial TIPS attempts were successful. Indications were: refractory ascites (18), acute variceal bleeding (12) and hepatorenal syndrome (2). There were no peri-procedure deaths, however. Ninety-day mortality was 20%. Outcomes in model of end-stage liver disease score and biochemical characteristics post-TIPS were comparable to those reported. Overall, TIPS dysfunction rate was 35% at 1 year. TIPS follow-up and patency surveillance was an ad hoc combination of Doppler ultrasound and venography. Conclusion:, TIPS procedure outcomes in our centre are similar to those reported in the literature from large centres. TIPS patency rates may be improved with regular monitoring and early intervention when stenosis occurs. [source] MANAGEMENT OF POPLITEAL ARTERY ANEURYSMSANZ JOURNAL OF SURGERY, Issue 10 2006Maher Hamish Background: Popliteal artery aneurysms (PAA) are the most common peripheral aneurysm and are recognized as ,the silent killer of the leg circulation'. The timing and type of interventions used in their treatment is still controversial. This review examines the published data on the natural history, epidemiology, clinical presentation and management options available. The aim of this study is to try and reach a consensus with regards to the best management of PAA. Method: A systematic review of data in the English published works since 1980. Results: The authors include 53 studies containing 2854 patients with 4291 PAA. Most published data involves retrospective studies and personal experience, with one multicentre study. No randomized controlled studies exist regarding the management of PAA. Conclusions: 1. Although most PAA are of atherosclerotic origin in old patients, trauma, infection and family history are the main causes in young patients. 2. Great vigilance is needed for diagnosis as only approximately five patients are seen each year by a major vascular centre. There is no place for screening programmes to detect PAA. 3. Approximately 45% of patients are asymptomatic at the time of initial diagnosis. Aortic aneurysms are found in 40% and bilateral PAA in 50% of patients. More than 95% of patients are men with a mean age of 65 years and 45% have hypertension. 4. Surgical reconstruction is recommended for all symptomatic and asymptomatic aneurysms larger than 2 cm. Five-year graft patency rates after surgical repair range from 30 to 97%, with 5-year limb salvage ranging from 70 to 98%. Patient survival rates at 5 and 10 years are 75 and 46%, respectively. 5. If carried out carefully, intra-arterial thrombolysis can safely prepare patients presenting with acute ischaemia from occluded PAA, for surgical revascularization to restore distal run-off. 6. Endovascular repair of a PAA is a feasible option, although little evidence is yet available. 7. Lifelong, careful patient surveillance is essential to detect and treat new aneurysms at other sites. [source] Alcohol Pretreatment of Small-diameter Expanded Polytetrafluoroethylene Grafts: Quantitative Analysis of Graft Healing Characteristics in the Rat Abdominal Aorta Interposition ModelARTIFICIAL ORGANS, Issue 7 2009Erman Pektok Abstract Long-term patency rates of small-diameter expanded polytetrafluoroethylene (ePTFE) vascular prostheses are unsatisfactory. Treatment of ePTFE grafts by alcohol before implantation was reported to increase hydrophilic properties, yielding better endothelialization and cellular in-growth, thus improving graft healing. The effect of alcohol pretreatment on ePTFE grafts and postoperative healing characteristics of wet ePTFE grafts were evaluated in this study. Ten sterile ePTFE grafts (2 mm ID, 30 µ thru-pore, 12 mm long) were implanted in the infrarenal aorta of male Sprague-Dawley rats (324,380 g). Five grafts were treated with ethanol 70% and soaked with saline solution before implantation (wet); five nontreated grafts served as control. All rats were sacrificed after digital subtraction angiography and sampling of the graft for histological investigation after 3 weeks. Histomorphometric analysis was performed for endothelial coverage, cellular in-growth, and intimal hyperplasia. All grafts were patent at the end of 3 weeks in both groups. Histological evaluation revealed significantly better endothelial coverage and prominent infiltration by fibroblasts and lymphocytes in the wet group. Endothelial coverage (31.03 ± 10.61% vs. 13.03 ± 9.46%, P = 0.03) and cellular infiltration of grafts (50.91 ± 8.55% vs. 39.29 ± 10.70%, P = 0.11) were higher in the wet group. Area of intimal hyperplasia per graft length was also higher in the wet group (5.32 ± 4.75 µm2/µm vs. 2.69 ± 3.41 µm2/µm, P = 0.36). Wetting of ePTFE grafts with ethanol 70% pretreatment before implantation might have a beneficial effect on long-term patency of small-diameter vascular grafts due to facilitated graft healing. [source] Changes in Vein Dynamics Ranging from Low to High Pressure Levels as a Determinant of the Differences in Vein Adaptation to Arterial Hemodynamic ConditionsARTIFICIAL ORGANS, Issue 7 2007Yanina Zócalo Abstract:, The causes of the regional differences in venous grafts patency rates are partially understood. Differences in vein dynamics during physiological situations could determine differences in veins' capability to face arterial conditions and could contribute to the dissimilar performance of veins as arterial grafts. In vitro pressure and diameter were measured in four different veins during physiological and arterial (graft) pressure conditions. A diameter,pressure transfer function was designed. Compliance, viscous and inertial properties; circumferential stresses and deformation; and buffering function were calculated. Regional differences in veins' dynamics, but not in buffering function were found during physiological and arterial conditions. The back vein (femoral) showed the least changes when submitted to arterial conditions. Arterial conditions represent different changes in vein dynamics depending on the segment considered. The regional differences in vein dynamics, both at physiological and graft conditions, could contribute to explain the dissimilar results of venous grafts. [source] Selective use of ultrasonographic vascular mapping in the assessment of patients before haemodialysis access surgeryBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 11 2005A. C. Wells Background: Use of routine preoperative ultrasonography to determine the optimum site for haemodialysis access surgery increases the number of distal arteriovenous fistulas formed and improves overall patency rates. Nevertheless its use in all patients is time consuming and costly. This study examined whether clinical parameters could be used to determine the requirement for preoperative ultrasonography. Methods: Between March 2002 and October 2003, 145 consecutive patients were reviewed in the vascular access clinic. Patients were first assessed clinically, a site for vascular access surgery was proposed, and the need for radiological mapping studies recorded. A second, blinded, clinician determined the site for vascular access surgery using ultrasonography. The correlation between clinical and ultrasonographic findings was then examined. Results: Ultrasonography was considered unnecessary using clinical criteria in 106 patients. Subsequent ultrasonographic mapping altered the management of only one patient. In contrast, the management of 18 of the 39 patients in whom ultrasonography was thought necessary was influenced by radiological imaging. A 1-year primary patency rate of 77·0 per cent was achieved following vascular access surgery on the study population. Conclusion: Clinical parameters could be used to determine the need for preoperative vascular ultrasonographic mapping; imaging was not required in the majority of patients. Copyright © 2005 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] Impact of angioplasty on infrainguinal bypass for critical ischaemia of the legBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 4 2001D. Evoy Background: Both angioplasty and infrainguinal bypass procedures may be used to achieve limb salvage in patients with critical ischaemia. The authors investigated the effect of the introduction of angioplasty on the frequency with which infrainguinal bypass was performed and, second, the changes in outcome of infrainguinal bypass following the introduction of angioplasty. Methods: All patients had critical ischaemia of the leg. Three patient groups were studied: 215 patients undergoing infrainguinal bypass before the introduction of angioplasty (1986,1991), 216 patients who had infrainguinal bypass after the introduction of angioplasty (1993,1998) and 193 patients undergoing angioplasty in the same 5-year interval (1993,1998). Results: The age and risk profile of the three groups was identical. The overall caseload increased by 19 per cent following the introduction of angioplasty. Primary and secondary patency rates were superior for bypass compared with angioplasty, but were similar for the two bypass groups (5-year primary patency rate 60 per cent versus 18-month primary patency rate 45 per cent; 5-year secondary patency rate 80 per cent versus 18-month secondary patency rate 60 per cent). By 18 months 26 per cent of patients having angioplasty had gone on to have bypass. The limb salvage rate of 90 per cent at 1 year was similar for all groups. Survival was significantly higher in the group of patients undergoing bypass from 1993 to 1998 compared with the other two groups (80 versus 60 per cent; P < 0·0002). Conclusion: The introduction of angioplasty has increased overall workload. Angioplasty has a lower patency rate than bypass but a comparable limb salvage rate, making it a suitable alternative to bypass in the management of patients with critical ischaemia. © 2001 British Journal of Surgery Society Ltd [source] Hepatocellular carcinoma with main portal vein tumor thrombusCANCER, Issue 6 2009Treatment with 3-dimensional conformal radiotherapy after portal vein stenting, transarterial chemoembolization Abstract BACKGROUND: Hepatocellular carcinoma (HCC) with main portal vein tumor thrombus (MPVTT) is often associated with poor prognosis. We retrospectively assessed the effectiveness of percutaneous transhepatic portal vein stenting and transarterial chemoembolization (PTPVS-TACE) combined with or without 3-dimensional conformal radiotherapy (3-DCRT) for HCC with MPVTT. METHODS: Forty-five patients with HCC complicated by MPVTT were treated with PTPVS-TACE. Among them, 16 patients (group A) received 3-DCRT with 30-60Gy as daily 2Gy fractions. The remaining 29 patients (group B) received no radiotherapy. The tumor responses, complications, stent patency rates, and cumulative survival rates were evaluated, and the Kaplan-Meier method and log-rank test were used for survival analysis. RESULTS: No severe complications were associated with PTPVS-TACE and 3-DCRT. The objective response rate (CR and PR) was 35.6%. The 60-, 180-, and 360-day cumulative stent patency rates were 93.3%, 62.2%, and 34.6% in group A, and 58.6%, 21.7%, and 10.8% in group B, respectively, showing significant difference between the 2 groups (P < .01). The mean patency time was 475.20 ± 136.97 and 199.58 ± 61.40 days, respectively. The 60-, 180-, and 360-day cumulative survival rates were 93.8%, 81.3%, and 32.5%, respectively, for group A, 86.2%, 13.8%, and 6.9%, respectively, for group B. Significant statistical differences were detected between the 2 groups (P < .01). CONCLUSIONS: These findings suggest that sequential therapy by PTPVS-TACE-3-DCRT is possibly an effective treatment modality for HCC complicated by main portal vein tumor thrombus. Cancer 2009. © 2009 American Cancer Society. [source] Drug eluting stents for below the knee lesions in patients with critical limb ischemia,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 1 2008Long-term follow-up Abstract Objectives: The purpose of this study was to assess the long-term limb preservation and/or healing of ulcers in patients with critical limb ischemia (CLI) and severe infrapopliteal atherosclerotic disease treated with drug eluting stents (DES). Background: Percutaneous revascularization has become an effective treatment for CLI in patients with infrapopliteal atherosclerotic disease. Recent reports using DES in patients with CLI have documented excellent short-term infrapopliteal vessel patency. Higher primary patency rates in infrapopliteal vessels treated with DES could translate into better long-term clinical outcomes and improved limb salvage rates. Methods: Twenty-four consecutive patients with CLI (defined as rest pain, nonhealing ulcers, or gangrene) because of severe infrapopliteal disease were treated with DES from August 2004 to June 2006. Results: Procedural success was achieved in 96% (27/28) of targeted lesions. There were no procedure-related deaths, acute vessel thrombosis events, or need for urgent surgical intervention. There was one case of distal embolization. Clinical follow up, ranging 8,34 months, is available for 100% of patients of which 83% (20/24) achieved limb preservation and healing. Angiographic and/or sonographic follow up, ranging 6,34 months, is available in 79% (19/24) of patients of which 95% (18/19) had patent target vessels. Conclusions: DES is a safe and effective long-term option for CLI due to severe infrapopliteal arterial disease. Long-term vascular patency led to a high rate of limb preservation and low amputation rate. A multicenter trial should further elucidate the role of DES in the treatment of CLI. © 2008 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||