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Objectives: Constantly increasing number of procedures performed – endovascular or hybrid in patients with aortoiliac occlusive disease during the last decades finds its explanation in the lower morbidity and mortality rates, compared to bypass surgery. The purpose of the current survey was to estimate patients’ radiation exposure in aortoiliac segment after endovascular or hybrid revascularization and to study the main factors which have direct contribution. Methods: A retrospective study of 285 procedures conducted with the help of a mobile C-arm system in 223 patients was performed. Procedures were grouped according to criteria such as: type of intervention, vascular access, level of complexity and operating team. Different analyses were performed within the groups and dose values. Results: The median values of kerma–air product (KAP), the number of series and the peak skin dose (PSD) significantly increase with the increasing number of vascular accesses: for one access (16.68 Gy.cm2, 6 and 336 mGy), for two (56.93 Gy.cm2, 11 and 545 mGy), and for three (102.28 Gy.cm2, 15 and 781 mGy). Significant dependence was observed in the case of single access site between the type of access and the dose values: hybrid and retrograde common femoral artery/superficial femoral artery (CFA/SFA) endovascular accesses, 10.06 Gy.cm2/301 mGy and 13.23 Gy.cm2/318 mGy respectively, in contrast with the contralateral CFA and left brachial access, 33 Gy.cm2/421 mGy and 38.33 Gy.cm2/448 mGy respectively. Conclusion: The results demonstrate that the most important factors increasing the dose values are number and type of vascular accesses, followed by the combination and number of implanted stents with the complexity of the procedure. The PSD values for a single procedure were between 2 and 12 times lower than those IAEA proposed as trigger levels for radiation-induced erythema. This study shows that trigger levels were not reached even for patients with repeated procedures in the same segment in 1-year period. Advances in knowledge: The study gives important understanding and clarity on the growing awareness for dose-modifying factors during endovascular and hybrid revascularization of aortoiliac segment.

Objectives: To assess the feasibility of whole-body dual-energy computed tomographic angiography (DECTA) at 40 keV with 50% reduced iodine dose protocol. Methods: Whole-body CTA was performed in 65 patients; 31 of these patients underwent 120 kVp single-energy computed tomographic angiography (SECTA) with standard iodine dose (600 mgI/kg) and 34 with 40 keV DECTA with 50% reduced iodine dose (300 mgI/kg). SECTA data were reconstructed with adaptive statistical iterative reconstruction of 40% (SECTA group), and DECTA data were reconstructed with adaptive statistical iterative reconstruction of 40% (DECTA-40% group) and 80% (DECTA-80% group). CT numbers of the thoracic and abdominal aorta, iliac artery, background noise, signal-to-noise ratio (SNR), and arterial depiction were compared among the three groups. The CT dose index volumes (CTDIvol) for the thorax, abdomen, and pelvis were compared between SECTA and DECTA protocols. Results: The vascular CT numbers and background noise were found to be significantly higher in DECTA groups than in the SECTA group (p < 0.001). SNR was significantly higher in the order corresponding to DECTA-80%, SECTA, and DECTA-40% (p < 0.001). The arterial depiction was comparable in almost all arteries; however, intrapelvic arterial depiction was significantly worse in DECTA groups than in the SECTA group (p < 0.0001–0.017). Unlike the pelvic region (p = 0.055), CTDIvol for the thorax (p < 0.0001) and abdomen (p = 0.0031) were significantly higher in the DECTA protocol than in the SECTA protocol. Conclusion: DECTA at 40 keV with 50% reduced iodine dose provided higher vascular CT numbers and SNR than SECTA, and almost comparable arterial depiction, but had a degraded intrapelvic arterial depiction and required a larger radiation dose. Advances in knowledge: DECTA enables 50% reduction of iodine dose while maintaining image quality, arterial depiction in almost all arteries, vascular CT numbers, and SNR; however, it does not allow clear visualization of intrapelvic arteries, requiring a slightly larger radiation dose compared with SECTA with standard iodine dose.

BACKGROUND Peripheral vascular disease and iliac arterial calcification are prevalent in kidney transplant candidates and jeopardize graft outcomes. We report our experience with computed tomography (CT) screening for iliac arterial calcification. MATERIAL AND METHODS We retrospectively reviewed electronic medical records of 493 renal transplant candidates from protocol initiation in 2014. Non-contrast CT was performed or retrospectively reviewed if any of the following criteria were present: diabetes, ESRD >6 years, 25 pack-years of smoking or current smoker, diagnosis of peripheral vascular disease, parathyroidectomy, and coronary artery disease intervention. Differences in evaluation and transplant outcomes between groups were compared with chi-squared analysis. Multivariate logistic regression identified predictive criteria for presence of iliac arterial calcification. RESULTS Of 493 candidates evaluated, CTs were reviewed in 346 (70.2%). Iliac arterial calcification was identified in 119 screened candidates (34.4%). Of candidates with iliac arterial calcification identified on CT, 16 (13.4%) were excluded for CT findings, and 9 (7.6%) had their surgical management plan changed. Overall, 91 (76.5%) candidates with iliac arterial calcification on CT were approved, compared to 203 (89.4%) without calcification (P

Objective: To assess the safety and efficacy of transcatheter arterial embolization (TAE) of the inferior mesenteric artery (IMA) for the management of post-partum hemorrhage (PPH). Methods: A retrospective analysis was performed regarding eight patients (mean age, 34.4 y; age range, 31 – 40 y) who underwent TAE of the IMA for PPH between March 2001 and September 2018. Obstetric records, including maternal characteristics, clinical manifestations, complications, and clinical outcomes, as well as TAE details were obtained. Results: All eight patients had primary PPH and the vaginal delivery mode. CT scans of two patients showed active bleeding from the lower uterus or hematoma and with the origin of contrast extravasation abutting the adjacent rectum. In seven patients, an aortogram or IMA arteriogram following persistent vaginal bleeding after sufficient embolization of the bleeding focus from the bilateral iliac arteries, found the bleeding focus of the IMA, while in one patient, the IMA bleeding focus was found at the second session 4 h after the first session. TAE of the IMA was technically successful in all eight patients and cessation of bleeding without repeated TAE or additional hemostatic surgery was achieved in all patients after TAE of the IMA. There were neither procedure-related complications nor bowel ischemia during follow-up. Conclusion: TAE of the IMA for PPH was safe and effective with successful hemostasis. Bleeding from the IMA should be suspected when there is persistent vaginal bleeding after sufficient embolization of bleeders from the bilateral iliac arteries. Advances in knowledge: Bleeding from the IMA should be suspected when there is persistent vaginal bleeding after sufficient embolization of bleeders from the bilateral iliac arteries.

// Sylvia Otto 1 , Kristin Jaeger 1 , Frank D. Kolodgie 2 , Diana Muehlstaedt 1 , Marcus Franz 1 , Sabine Bischoff 3 , Harald Schubert 3 , Hans R. Figulla 1 , Renu Virmani 2 and Tudor C. Poerner 1 1 Department of Medicine 1, Division of Cardiology, University Hospital of Jena, Thuringia, Germany 2 Institute for Laboratory Animal Science and Animal Protection (IVuT), University Hospital of Jena, Thuringia, Germany 3 CV Path Institute Inc., Gaithersburg, MD, USA Correspondence to: Sylvia Otto, email: // Keywords : PPARg, ciglitazone, endothelium, vascular remodeling, drug-eluting stents, Pathology Section Received : July 16, 2016 Accepted : August 20, 2016 Published : August 24, 2016 Abstract Aim: Peroxisome proliferator-activated receptor-gamma (PPARg) agonists have known pleiotropic cardiovascular effects with favourable properties in vascular remodeling, and specifically in suppression of vascular smooth muscle cell proliferation. A novel vascular stent coating using the PPARg ligand ciglitazone (CCS) was investigated regarding its effects on endothelialization after 7 and 28 days. Methods: Microporous bare metal stents (BMS) were coated with ciglitazone by ultrasonic flux with a load of 255 μg ciglitazone/stent. SixteenNew Zealand white rabbits, fed a with high cholesterol diet, underwent stent implantation in both iliac arteries. Everolimus-eluting stents (EES) and BMS were comparators. Histology (CD 31 immunostaining, confocal and scanning electron microscopy, morphometry) was performed after 7 and 28 days and by OCT (optical coherence tomography) in vivo after 28 days. Results: Microscopy showed comparable results with near complete endothelialization in CCS and BMS (%CD31 above stent struts after 7 days: 67.92±36.35 vs. 84.48±23.86; p = 0.55; endothel % above stent struts: 77.22±27.9 vs. 83.89±27.91; p = 0.78). EES were less endothelialized with minimal fibrin deposition, not found in BMS and CCS (% CD 31 above struts after 28 days, BMS: 100.0±0.0 vs. EES: 95.9±3.57 vs. CCS: 100.0±0.0; p = 0.0292). OCT revealed no uncovered struts in all stents after 28 days. Conclusions: Polymer-free coating with ciglitazone, a PPARg agonist is feasible and stable over time. Our data prove unimpaired endothelial coverage of a ciglitazone-coated vascular stent system by histology and OCT. Thus, this PPARg agonist coating deserves further investigation to evaluate its potency on local neointimal suppression.

Objective:We evaluated the risk factors for massive bleeding based on angiographic findings in patients with placenta previa and accreta who underwent balloon occlusion of the internal iliac artery (BOIA) during cesarean section.Methods:We performed a retrospective analysis using the clinical records of 42 patients with placenta previa and accreta who underwent BOIA during cesarean section between 2006 and 2017 in Gunma university hospital. We reviewed incidence of collateral arteries to the uterus on the initial aortography. We evaluated the visualization of the ovarian artery arising directly from the abdominal aorta, round ligament artery arising from the external iliac artery/inferior epigastric artery, and the iliolumbar artery. In addition, the clinical characteristics were reviewed. Patients with an estimated blood loss during delivery of >2500 ml, >4 packed red blood cell transfusions, uterine artery embolization after delivery, or hysterectomy were defined as the massive bleeding group. We compared between the massive and non-massive bleeding groups.Results:20 patients (48%) had a massive bleeding. No procedure-related severe complications were observed. The massive and non-massive bleeding groups differed in terms of operation time (p < 0.001), hysterectomy (p < 0.001), post-operative hospital stay (p < 0.05), and visualization of round ligament arteries to the uterus [15/20 (75%) patients, p < 0.01].Conclusion:The incidence of collateral blood supply from a round ligament artery to the uterus may be a risk factor for massive bleeding in patients with placenta previa and accreta who have undergone BOIA during cesarean section.Advances in knowledge:Angiographic visualization of collateral circulation from the round ligament artery to the uterus may be a risk factor for massive bleeding in patients with placenta previa and accreta who have undergone BOIA during cesarean section.

BACKGROUND: A 68 year-old female is referred to the Gastroenterology consultation service from the Emergency Department (ED) for brisk gastrointestinal bleeding. Five months prior, she was admitted for multiple intra-abdominal abscesses from perforated appendix, requiring right hemicolectomy and small bowel resection. She was also known for deep vein thrombosis on low-molecular-weight heparin and ovarian cancer considered in remission. AIMS: Case report and review of the literature METHODS: See above RESULTS: She presented to the Royal Victoria Hospital for witnessed syncope and significant hematochezia of acute onset. She was profoundly hypotensive, requiring aggressive fluid resuscitation. Her physical exam showed mild epigastric and right lower quadrant pain, as well as bright red blood on the digital rectal examination. Her initial hemoglobin of 80 dropped to 32, with ongoing hematochezia. Nasogastric tube insertion was unsuccessful. A gastroscopy showed normal mucosa with no blood seen up to the distal duodenum. Overnight, she suffered from a recurrent episode of brisk hematochezia, requiring the activation of a massive transfusion protocol. Given her ongoing blood loss, she was sent for a mesenteric angiogram which identified an actively-bleeding fistula from the right external iliac artery to the transverse colon. The interventional radiologist decided to deploy a balloon-assisted covered stent to close off the fistula. Immediately after deployment, the patient’s hemodynamics improved. The vascular surgery team decided against operative management in view of a suspected low operative success from multiple prior surgeries and radiation therapy. Asymptomatic, she was discharged eleven days after her presentation. CONCLUSIONS: This rare case highlights the importance of early recognition of life-threatening conditions, such as arterioenteric fistulas (AEF). It also illustrates a rare mechanism of fistula formation. Most cases of AEFs are described as secondary, namely as a complication of prior aortic reconstruction. Approximately 250 cases of primary AEF have been reported in the published literature, of which only 15% affected the colon. In our patient’s case, the main risk factors for primary AEF were encasing peri-iliac abscesses, subsequent bowel manipulation and prior radiation therapy. Prompt investigation is a key component of AEF prognosis. Angiography permits direct AEF visualization and potential placement of a covered stent graft, either as a bridge to open surgery or as a definitive therapy for patients with high operative risk. However, stent placement harbours significant rebleeding rates and infectious complications. Optimal management in these cases remains controversial, such as the use of prophylactic antibiotics or serial imaging. Even though high-quality evidence is scarce, angiography with endovascular intervention is considered first-line treatment in patients with hemodynamic instability. FUNDING AGENCIES: None

Occlusion of the internal iliac artery (IIA) may be necessary prior to endovascular aneurysm repair (EVAR) to prevent endoleak Type II. We compared efficacy and clinical outcome after proximal occlusion of an unaffected IIA (ProxEmbx) using an Amplatzer vascular plug (AVP) I vs distal occlusion of aneurysmatic IIA with coils and plugs (DistEmbx).Between 2009 and 2012, 22 patients underwent EVAR. In 9 patients with unaffected IIA, occlusion was performed by a single AVP. In 13 patients with aneurysmatic IIA, more distal embolization (DistEmbX) was conducted by using several coils and additional AVPs. Retrospectively, technical success, clinical outcome and complications were evaluated.Embolization of the IIA was successful in all patients. Three patients with more DistEmbX of aneurysmatic IIAs suffered from new onset of sexual dysfunction after occlusion without statistically significant difference (p 0.05). Transient buttock claudication was observed in three patients in each group. Bowel ischaemia did not occur. The procedure time (p = 0.013) and fluoroscopy time (p = 0.038) was significantly lower in the ProxEmbx group than in the DistEmbx group.Proximal occlusion of an unaffected IIA and more distal occlusion of an aneurysmatic IIA prior to EVAR had the same technical and clinical outcome. However, proximal plug embolization of an unaffected IIA prior to EVAR was associated with shorter procedure and fluoroscopy time in comparison with more DistEmbX of aneurysmatic IIAs. Advances in knowledge: Proximal embolization of unaffected IIA and DistEmbX of aneurysmatic IIA before EVAR are both effective in preventing Type II endoleaks and have the same technical and clinical outcome.

Bioresorbable scaffolds have the potential to overcome several problems associated with metallic stents. Bioresorbable poly-L-lactic acid (PLLA) scaffold implantation for the treatment of peripheral artery disease has already been reported in animal models and clinical trials; however, no studies comparing PLLA scaffolds and bare metal stents (BMSs) with regard to early vascular morphological changes, identified using intravascular ultrasound (IVUS) analysis, have been reported. In this study, PLLA scaffolds and BMSs were implanted bilaterally in iliac arteries of five miniature pigs. Digital subtraction angiography and IVUS were performed before and immediately after stent implantation and at 6-week follow-up. All PLLA scaffolds and BMSs were patent at 6-week follow-up. Per IVUS analysis, the percent area stenosis did not significantly differ between PLLA scaffolds and BMSs (65.7% vs. 67.2%, P = .761). Furthermore, percent vessel lumen change also did not differ significantly. Neointima formation (the neointimal area plus medial area) was significantly less with PLLA scaffolds than with BMSs (15.65 mm2 vs. 25.69 mm2, P < .001). In conclusion, based on IVUS results, short-term results after stent implantation in porcine iliac arteries were comparable between PLLA scaffolds and BMSs. Therefore, PLLA scaffolds are safe and feasible for implantation in peripheral arteries.

Perfusion CT may have the potential to quantify the degree of angiogenesis of solid tumours in vivo. This study aims to identify the practical and technical challenges inherent to the technique, and evaluate its feasibility in colorectal tumours.51 patients from 2 institutions prospectively underwent a single perfusion CT on 2 different multidetector scanners. The patients were advised to breath-hold as long as possible, followed by shallow breathing, and were given intravenous buscopan to reduce movement. Numerous steps were explored to identify the challenges.43 patients successfully completed the perfusion CT as per protocol. Inability to detect the tumour (n=3), misplacement of dynamic sequence co-ordinates (n=2), failure of contrast injection (n=2) and displacement of tumour (n=1) were the reasons for failure. In 14 cases excessive respiratory motion displaced the tumour out of the scanning field along the temporal sequence, leading to erroneous data capture. In nine patients, minor displacements of the tumour were corrected by repositioning the region of interest (ROI) to its original position after reviewing each dynamic sequence slice. In 20 patients the tumour was stable, and data captured from the ROI were representative, and could have been analysed by commercially available Body Tumor Perfusion 3.0® software (GE Healthcare, Waukesha, WI). Hence all data were manually analysed by MATLAB® processing software (MathWorks, Cambridge, UK).Perfusion CT in tumours susceptible to motion during acquisition makes accurate data capture challenging and requires meticulous attention to detail. Motion correction software is essential if perfusion CT is to be used routinely in colorectal cancer.

Several studies demonstrated feasibility of visual assessment of the common femoral artery Doppler waveform, in an indirect evaluation of aorto-iliac segment stenosis. Patients with cardiac diseases referred for echocardiography often have coexistent arterial pathology. Since many of them are potential candidates for endovascular procedures, we decided to study, whether echocardiography can be useful for detection of aorto-iliac occlusive disease. We evaluated 92 patients with abdominal aortic aneurysm or peripheral artery occlusive disease, referred from the vascular surgery department for cardiac evaluation before surgery. At the end of an echocardiographic examination, evaluation of flow in the distal external iliac arteries with an echocardiographic probe was performed. The Doppler waveform was classified into normal--with early diastolic flow reversal or abnormal--without early diastolic flow reversal. Echocardiographic results were compared in a blinded fashion with reports from computed tomography angiography. Overall there were 58 iliac segments with significant (≥70%) area stenosis or occlusion and 126 iliac segments without significant disease on computed tomography angiography. Abnormal Doppler waveform was found in 56 out of 58 abnormal iliac segments-sensitivity 97%, and normal waveform was found in 106 out of 126 normal iliac segments-specificity 84%. Positive predictive value of abnormal Doppler waveform for significant iliac disease was 74%, and negative predicting value was 98%. Detection of significant stenoses in aorto-iliac segments is feasible with echocardiography. Further studies are necessary to evaluate its potential utility in a population of patients with cardiac disease referred for echocardiographic study.

Objective: We investigated the potential of low-dose CT angiography for accurate assessment of in-stent restenoses (ISRs) of the iliac artery. Method: A Rando anthropomorphic phantom (Alderson Research Labs, Stanford, CA), custom-made wax simulating hyperplastic tissue and a nitinol stent were used to simulate a patient with clinically relevant iliac artery ISRs. The cylindrical lumen was filled with a solution of iodine contrast medium diluted in saline, representing a patient’s blood during CT angiography. The phantom was subjected to standard- and low-dose angiographic exposures using a modern multidetector (MD) CT scanner. The percentage of ISR was determined using the profile along a line normal to the lumen axis on reconstructed images of 2 and 5 mm slice thickness. Percentage ISRs derived using the standard- and low-dose protocols were compared. In a preliminary study, seven patients with stents were subjected to standard- and low-dose MDCT angiography during followup. The resulting images were assessed and compared by two experienced radiologists. Results: The accuracy in measuring the percentage ISR was found to be better than 12% for all simulated stenoses. The differences between percentage ISRs measured on images obtained at 120 kVp/160 mAs and 80 kVp/80 mAs were below 6%. Patient image sets acquired using low-exposure factors were judged to be of satisfactory diagnostic quality. The assessment of ISR did not differ significantly between image sets acquired using the standard factors and those acquired using the low-exposure factors, although the mean reduction in patient effective dose was 48%. Conclusion: A reduction in exposure factors during MDCT angiography of the iliac artery is possible without affecting the accuracy in the determination of ISRs.

Aim: to investigate effects of Losartan on expression of connexin 40 and 43 (Cx40 and Cx43), in arteries at the early stage of atherosclerosis in a rabbit model. Methods: A total of 28 male New Zealand white rabbits were divided into following groups: control group, high fat diet group, and Losartan group (10 mg/kg/day). Losartan was administrated in food for two weeks. Iliac arteries were obtained for immunohistochemistry, transmission electron microscopy, Western blot, and reverse transcriptase-polymerase chain reaction (RT-PCR). Results: Transmission electron microscopy revealed abundant gap junctions between neointimal smooth muscle cells (SMCs), which were markedly reduced by treatment. RT-PCR and Western blot assay showed that the mRNA and protein expression of Cx40 and Cx43 were elevated in the neointimal area at the early stage of atherosclerosis. The mRNA and protein expression of Cx43 were significantly down-regulated by losartan treatment but those of Cx40 were not markedly changed. Conclusion: Cx40 and Cx43 in the neointimal SMCs were up-regulated at the early stage of atherosclerosis. Losartan (an angiotensin-converting enzyme inhibitor) could reduce neointima proliferation and down-regulate the elevated protein expression of Cx43, suggesting the rennin-angiotensin system (RAS) plays an important role in the remodeling of gap junction between ventricular myocytes under pathological conditions.

Contains fulltext : 152926.pdf (Publisher’s version ) (Closed access) A persistent clinical demand exists for a suitable arterial prosthesis. In this study, a vascular conduit mimicking the native 3-layered artery, and constructed from the extracellular matrix proteins type I collagen and elastin, was evaluated for its performance as a blood vessel equivalent. A tubular 3-layered graft (elastin-collagen-collagen) was prepared using highly purified type I collagen fibrils and elastin fibers, resembling the 3-layered native blood vessel architecture. The vascular graft was crosslinked and heparinised (37 +/- 4 mug heparin/mg graft), and evaluated as a vascular graft using a porcine bilateral iliac artery model. An intra-animal comparison with clinically-used heparinised ePTFE (Propaten(R)) was made. Analyses included biochemical characterization, duplex scanning, (immuno)histochemistry and scanning electron microscopy. The tubular graft was easy to handle with adequate suturability. Implantation resulted in pulsating grafts without leakage. One week after implantation, both ePTFE and the natural acellular graft had 100% patencies on duplex scanning. Grafts were partially endothelialised (Von Willebrand-positive endothelium with a laminin-positive basal membrane layer). After one month, layered thrombi were found in the natural (4/4) and ePTFE graft (1/4), resulting in occlusion which in case of the natural graft is likely due to the porosity of the inner elastin layer. In vivo application of a molecularly-defined tubular graft, based on nature's matrix proteins, for vascular surgery is feasible.

Background: Various techniques for vascular control have been used during urologic laparoscopic procedures. The importance of optimizing the vessel length and securing reliable vascular control are critical for procedures like laparoscopic donor nephrectomy. We aimed to determine the length of vessel lost by using 4 common techniques of vascular control in a fresh human cadaveric vascular model. Methods: The techniques include application of 2 nonabsorbable polymer-ligating clips (10-mm Hem-o-Lok MLX Weck Closure Systems, Research Triangle Park, NC), Endo-GIA II stapler (30-mm length, 2.5-mm staples, Auto Suture, US Surgical, Norwalk, CT), Endopath ETS35 stapler (35mm length, 2.5mm staples, Ethicon Endo-Surgery), and the Endo Ta-30 stapler (30-mm length, 2.5-mm staples, Auto Suture, US Surgical, Norwalk, CT). Results: The Endo-TA-30 stapler and the polymer clips resulted in significantly less compromise of the vessel length, when compared with the other methods of vascular control. Conclusions: The Endo-TA-30 stapler and the polymer clips can be applied during laparoscopic procedures where optimizing vascular length is important.

Objective: Neointimal hyperplasia is a major complication of endovascular stent placement with consequent in-stent restenosis or occlusion. Improvements in the biocompatibility of stent designs could reduce stent-associated thrombosis and in-stent restenosis. We hypothesised that the use of a diamond-like carbon (DLC)-coated nitinol stent or a polyethylene glycol (PEG)-DLC-coated nitinol stent could reduce the formation of neointimal hyperplasia, thereby improving stent patency with improved biocompatibility. Methods: A total of 24 stents were implanted, under general anaesthesia, into the iliac arteries of six dogs (four stents in each dog) using the carotid artery approach. The experimental study dogs were divided into three groups: the uncoated nitinol stent group (n58), the DLC-nitinol stent group (n58) and the PEG-DLC-nitinol stent group (n58). Results: The mean percentage of neointimal hyperplasia was significantly less in the DLC-nitinol stent group (26.7i7.6%) than in the nitinol stent group (40.0i20.3%) (p50.021). However, the mean percentage of neointimal hyperplasia was significantly greater in the PEG-DLC-nitinol stent group (58.7i24.7%) than in the nitinol stent group (40.0i20.3%) (p50.01). Conclusion: Our findings indicate that DLC-coated nitinol stents might induce less neointimal hyperplasia than conventional nitinol stents following implantation in a canine iliac artery model; however, the DLC-coated nitinol stent surface when reformed with PEG induces more neointimal hyperplasia than either a conventional or DLCcoated nitinol stent.

Laparoscopic hernioplasty is a technique which can present a number of specific complications. This paper reviews the complications that can occur during laparoscopic hernia repair and ways to avoid them; it also describes the surgical technique used successfully in over 1000 cases. Initial experience suggests that complications can be avoided with adequate knowledge, attention to surgical anatomy and the proper technique of laparoscopic hernioplasty. Early recurrences are rare and invariably result from inadequate surgical technique. Inadequate fixation of the mesh, inadequate mesh size, and failure to cover unidentified wall defects (hernias which have never been repaired), are the main causes of early recurrence of hernia. Experience, knowledge of complications and how to avoid them, adequate training and attention to the anatomy of the inguinal region are the most important factors in correcting inguinal hernia successfully by laparoscopy.

The purposes of this study were (1) to evaluate the actual distance between the obturator artery and the ischial osteotomy site when performing periacetabular osteotomy via an anterior approach and (2) to determine a safe method to avoid injuring the obturator artery during this procedure. Twenty-nine hemipelves from cadavers were used in this study. The mean distance between the obturator artery and the ischial osteotomy site was 35.6 ± 7.5 mm and always exceeded 20 mm. Therefore, the procedure can be performed safely when a chisel blade of 20 mm or shorter is used.

Synthetic peptides corresponding to the Gap 26 and Gap 27 domains of the first and second extracellular loops of the major vascular connexins (Cx37, Cx40 and Cx43), designated as (43)Gap 26, (40)Gap 27, (37,40)Gap 26 and (37,43)Gap 27 according to Cx homology, were used to investigate the role of gap junctions in the spread of endothelial hyperpolarizations evoked by cyclopiazonic acid (CPA) through the wall of the rabbit iliac artery. Immunostaining and confocal microscopy demonstrated that gap junction plaques constructed from Cx37 and Cx40 were abundant in the endothelium, whereas Cx43 was the dominant Cx visualized in the media. None of the Cx-mimetic peptides affected endothelial hyperpolarizations evoked by CPA directly. When administered individually, (40)Gap 27, (37,40)Gap 26 and (37,43)Gap 27, but not (43)Gap 26, attenuated endothelium-dependent subintimal smooth muscle hyperpolarization. By contrast, only (43)Gap 26 and (37,43)Gap 27 reduced the spread of subintimal hyperpolarization through the media of the rabbit iliac artery. The site of action of the peptides therefore correlated closely with the expression of their target Cxs in detectable gap junction plaques. The findings provide further evidence that the EDHF phenomenon is electrotonic in nature, and highlight the contribution of myoendothelial and homocellular smooth muscle communication via gap junctions to arterial function.

The present study aimed to investigate the response of lumbar sympathetic nerve activity (LSNA) to the onset of rapid eye movement (REM) sleep and its contribution to the regulation of muscle blood flow during REM sleep in rats. Electrodes for the measurements of LSNA, electroencephalogram, electromyogram and electrocardiogram and a Doppler flow cuff for the measurements of blood flow in the common iliac and mesenteric arteries, also catheters for the measurements of systemic arterial and central venous pressures were implanted chronically. REM sleep resulted in a step increase in LSNA, by 22 ± 9% (mean ±s.e.m., P < 0.05), a reduction of iliac vascular conductance, by −16 ± 3% (P < 0.05) and a gradual increase in systemic arterial pressure, reaching a maximum value of 8.1 ± 2.0 mmHg (P < 0.05) at 89 s after onset of REM sleep, while mesenteric vascular conductance increased simultaneously by 5 ± 2% (P < 0.05). There was a significant (Pearson's correlation coefficient = 0.94, P < 0.05) inverse linear relationship between LSNA and the iliac blood flow. Unilateral lumbar sympathectomy blunted the reduction of iliac blood flow induced by the onset of REM sleep. The present observations suggest that the onset of REM sleep appears to be associated with a vasodilation in viscera and a vasoconstriction in skeletal muscle, such that systemic arterial pressure increases during REM sleep in rats.

Dehydroepiandrosterone has been implicated in vascular disease and its associated insulin resistance and hypertension, though little is known about its vascular effects. We have recently shown in prepubertal anaesthetized pigs that intravenous infusion of dehydroepiandrosterone caused coronary vasoconstriction through the inhibition of a vasodilatory beta-adrenergic receptor-mediated effect related to the release of nitric oxide. The present study was designed to investigate the effect of dehydroepiandrosterone on mesenteric, renal and iliac vascular beds. In prepubertal pigs of both sexes anaesthetized with sodium pentobarbitone, changes in superior mesenteric, left renal and left external iliac blood flow caused by intravenous infusion of dehydroepiandrosterone were assessed using electromagnetic flowmeters. Changes in heart rate and arterial blood pressure were prevented by atrial pacing and by connecting the arterial system to a pressurized reservoir containing Ringer solution. In 22 pigs, infusion of 1 mg h(-1) of dehydroepiandrosterone decreased mesenteric, renal and iliac blood flow. In a further 10 pigs, dose-response curves were obtained by graded increases in the infused dose of hormone between 0.03 and 4 mg h(-1). The mechanisms of the above response were studied in the 22 pigs by repeating the experiment after haemodynamic variables had returned to the control values observed before infusion. Blockade of alpha-adrenoceptors with intravenous phentolamine (five pigs) did not affect the dehydroepiandrosterone-induced mesenteric, renal and iliac vasoconstriction. This response was abolished by blockade of beta(2)-adrenoceptors with intravenous butoxamine (five pigs) and by blockade of mesenteric, renal and iliac nitric oxide synthase with intra-arterial administration of N(omega)-nitro-L-arginine methyl ester (seven pigs), even after reversing the increase in local vascular resistance caused by the two blocking agents with intravenous infusion of papaverine. In five pigs, the increase in measured blood flow caused by intravenous infusion of isoproterenol (isoprenaline) was significantly reduced by infusion of dehydroepiandrosterone. The present study showed that intravenous infusion of dehydroepiandrosterone primarily caused mesenteric, renal and iliac vasoconstriction. The mechanisms of this response were shown to be due to the inhibition of a vasodilatory beta(2)-adrenergic receptor-mediated effect, which possibly involved the release of nitric oxide.

The purpose of the present study was to obtain insight into the natural development of adaptive intimal thickening and atherosclerosis in the arterial tree of human species. The morphometry and composition of the intimal layer were studied in the arterial system of elderly individuals. Post mortem, a total of 703 arterial segments were dissected from 24 subjects (age 81.9 +/- 9.9 years). From each subject, segments were dissected from 31 different arteries. Area stenosis [(plaque area/vessel area) x 100%] was determined in each segment. By (immuno)histochemistry, lipid content and the presence of inflammatory cells (macrophages) were assessed in the coronary, common carotid, brachial, radial and internal iliac arteries. Adaptive intimal thickening or advanced atherosclerosis was observed in all studied artery types. Area stenosis was highest in the coronary arteries (median, 30%) and lowest in the arteries supplying the brain (median,or = 7%). Plaques hiding a lipid-rich core and plaques with macrophage infiltration were observed in all five selected artery types. In summary, the present observation demonstrates that intimal thickening is a systemic process involving most artery types. Within elderly humans, features of advanced atherosclerotic disease, a lipid-rich core and macrophages, can be observed in the intimal layer of artery types that are recognised for their relation with clinical syndroms as well as artery types that remain clinically silent.

1. The role of a constitutively active population of alpha(1D)-adrenoceptors was analysed in arteries obtained from spontaneously hypertensive rats (SHR) and controls (WKY) divided into three groups: young prehypertensive, adult hypertensive, and adult animals chronically treated with captopril (50 mg kg(-1) per day orally) in order to prevent the hypertensive state. 2. In adult SHR, a significant increase in BMY 7378 potency (not in prazosin potency) was observed in aorta, mesenteric artery, and the first and second branches of the small mesenteric arteries with respect to WKY rats. This difference was not observed in iliac and tail arteries, which suggests an increased functional role of alpha(1D)-adrenoceptors only in some vessels of SHR. 3. The increase in the resting tone (IRT) observed in absence of agonist, inhibited by BMY 7378, that represents the constitutively active population of alpha(1D)-adrenoceptors, was also significantly greater in aorta and mesenteric artery from adult SHR. 4. In young and captopril treated adult animals, no differences between strains with respect to BMY 7378 potency, or IRT were observed. 5. The increase in the functional role of alpha(1D)-adrenoceptors and their constitutive activity observed in hypertension is prevented by captopril treatment. The pathological consequence of this change is the slower rate of recovery of the basal tone after removal of an adrenergic stimulus, observed in vessels from hypertensive animals that had shown an increase in the functionality of constitutively active alpha(1D)-adrenoceptors. This change was not observed in prehypertensive or captopril treated animals.

1. We examined the effect of ischaemia on the neurogenic and nitric oxide (NO)-mediated urethral relaxation. 2. Rabbits were divided into control and urethral ischaemia (UI) groups, which was prepared by the partial occlusion of bilateral iliac arteries using blood vessel occluders. 3. Neurogenic and NO-mediated proximal urethral relaxation induced by electrical field stimulation (EFS) was greatly impaired in the UI group, while relaxation by sodium nitroprusside (SNP) as a NO donor showed no difference between the two groups. Pretreatment with L-arginine significantly improved but did not normalize the impaired relaxation in the UI group. Not only basal level, but also stimulated production of cyclic GMP with EFS, were significantly decreased in the UI group. 4. The tissue contents of N(G)-methyl-L-arginine (L-NMA) and asymmetric N(G), N(G)-dimethyl-L-arginine (ADMA) in the proximal urethra were increased following ischaemia. While L-arginine and symmetric N(G), N'(G)-dimethyl-L-arginine (SDMA) contents remained unchanged. Exogenously applied authentic L-NMA and ADMA (1 -- 100 microM) concentration-dependently inhibited the EFS-induced urethral relaxation in the control group. The inhibition with L-NMA and ADMA was undetectable in the presence of 3 mM L-arginine. 5. The Ca(2+)-dependent NOS activity in the urethra from the UI group was significantly lower than that from the control group and was not restored by an addition of 3 mM L-arginine. 6. These results suggest that the impaired neurogenic and NO-mediated urethral relaxation with ischaemia is closely related to the increased accumulation of L-NMA and ADMA and decreased NOS activity, which would result in an accelerated reduction in NO production/release.

All our patients with a recent thromboembolic occlusion of limb arteries treated with streptokinase have been reviewed retrospectively. Clearing of the main artery, as judged by arteriography or reappearance of arterial pulsations, occurred more often when treatment was started early. If only patients with an iliac, femoral, or popliteal artery occlusion are considered, those who received a lower initial dose had a significantly higher clearing rate and a significantly lower mortality than those who received a high initial dose (500,000 units of streptokinase or more). Therefore an initial standard dose of 1,200,000 units of streptokinase is no longer recommended in these conditions, and even an individually titrated initial dose of more than half a million units could be hazardous. If no neurological abnormalities were present on admission amputation was never necessary, even if clearing of the main artery did not occur. If there was sensory loss of at least part of a limb, amputation was avoided only if the pulsations returned in at least one artery of hand or foot.