Level Of Renal Arteries Research Articles

Protective Effect of Melatonin on Infrarenal Aortic Occlusion: This Effect Is Related to Anti-inflammatory Effect and Antioxidant Effect

Aortic cross-clamping is frequently exerted during surgery of the abdominal aorta (AA). Ischemia–reperfusion (IR) damage, which is observed in the surgery of AA, is a complex situation and is considered not only in lower extremities but also in remote tissues and organs like the lungs, kidneys, heart, and liver [1–6]. IR damage leads to important morbidity and mortality because of its systemic complications [7, 8]. Acute renal dysfunction, which is one of the most important complications following elective surgery of AA, is still a frequently seen condition (15– 22%), but acute kidney injury (AKI) is relatively rare (1.8– 4 %) [9, 10]. Infrarenal clamping of the aorta has been shown to decrease renal blood flow especially in patients who postoperatively developed renal failure [11–13]. This clamping procedure can cause vasoconstriction in renal arteries by forming turbulent flow in the aorta at the level of renal arteries [13]. The mechanisms underlying IR-induced organ damage are likely multifactorial and interdependent, involving hypoxia, inflammatory responses, and free radical damage [14–17]. Two of the most important factors in the pathophysiology of IR injury are reactive oxygen species (ROS) andmassive secretion of systemic inflammatorymediators, which especially increase in the reperfusion phase [18–20]. The endogenous antioxidants which are responsible for protecting against ROS during reperfusion have an important role in decreasing IR injury [18]. Melatonin, the main indolamine produced by the pineal gland, has been demonstrated to be an effective antioxidant and free radical scavenger [21–24]. Additionally, it has also shown an anti-inflammatory effect, which is suppression of proinflammatory cytokines like tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 [25– 30]. Melatonin has a small size and high lipophilicity; therefore, it crosses biological membranes easily and reaches all sections of the cell [22, 31, 32]. In this study, we aimed to investigate the anti-inflammatory, antioxidant, and protective effects of melatonin in IR damage developing in kidneys following infrarenal aortic occlusion–reperfusion in rat models and in preventing kidneys from this kind of damage.

Anesthetic management of descending thoracic aortobifemoral bypass for aortoiliac occlusive disease: Our experience

Background:Complete obstruction of the abdominal aorta at the renal artery level is a difficult surgical problem. Aortic clamping and declamping can lead to profound haemodynamic changes, myocardial infarction, ventricular failure or even death may result. These complications are important challenges in anesthetic management of these patients.Methods:Between August, 2010 and April, 2012, descending thoracic aorta to femoral artery bypass grafting was used to revascularize lower limbs in 11 patients in our institute. The anesthetic management of these patients is described here. Epidural catheter placement was done in T 5-6 or T 6-7 space for post operative pain relief. Induction was done by, Inj. Glycopyrolate 0.2 mg, Inj. Fentanyl 5 μg/kg., Inj. Pentothal sodium 5 mg/kg, Inj. Rocuronium 0.9 mg/kg, IPPV done. Left sided double lumen tube was inserted, Maintenance of Anesthesia was done by O2 + N2 O (30:70). Increments of Vecuronium and Fentanyl were given Monitoring of Heart rate, arterial pressure, central venous pressure were continuously displayed. The available pharmacological agents were used when there is deviation of more than 15% from base line.Results:In our study, inspite of measures taken to control rise in blood pressure during aortic cross clamping, a rise of 90 mm of Hg in one patient and 60-80 mm of Hg in four patients was observed, which was managed by sodium nitropruside infusion. At the end of surgery seven patients were extubated on the operation table. In remaining four patients DLT was replaced by single lumen endotracheal tube and were shifted to ICU on IPPV. They weaned off gradually in 3-5 hours. In our series blood loss was 400 ml to 1000 ml. There was no mortality in the first 24 hours. Postoperative bleeding was reported in one case which was re-explored and stood well.Conclusion:The anesthetic technique during aortic surgery is directed at minimizing the hemodynamic effects of cross clamping in order to maintain the myocardial oxygen supply demand ratio.

Positional relationships of abdominal aorta landmarks for angiography: observations from the intravascular space

To clarify the positional relationships of abdominal aorta (Ao) landmarks by way of observations from the intravascular space to facilitate angiography. A total of 95 donated Japanese cadavers were observed. We excluded 32 cadavers with anatomical variation at the celiac trunk (CT) or superior mesenteric artery (SMA), with flexure exceeding 5° in the aorta located cranially to the renal artery (RA), and with flexure exceeding 60° in the aorta located caudal to the RA. The maximum longitudinal diameter of the left (Lt.) RA was measured and the Ao was incised by frontal section to acquire photographs of the intravascular space. The inner diameter of the Ao at the Lt. RA level was investigated. The distances between the inferior borders of the CT, SMA, and Lt. RA were also used as the hypotenuse of a right-angled triangle. Lines parallel to the longitudinal diameter of the Ao and those parallel to the transverse diameter of the right-angled triangle were measured by a computer, and expressed as relative distance indexes using the transverse diameter of the aorta at the Lt. RA level as a reference point. The angle between the transverse axis of the Ao and the line connecting the CT to the SMA was also investigated. The mean diameter of the aorta was 20.6±2.0mm. The indexes between each blood vessel (longitudinal/transverse) were as follows: Lt. RA to CT 1.69/0.41, Lt. RA to SMA 0.86/0.51, and CT to SMA 0.82/0.13. The mean angle between the transverse axis of the Ao and CT to SMA was 81.9°±9.5°. These indexes should contribute to improving skills for workers new to angiography, and may reduce patient risk.

Radiologic findings of thoracic scoliosis due to giant ganglioneuroma

A 28-year-old male with scoliosis presented with complaints of dyspnea and vomiting. His medical history revealed a mediastinal ganglioneuroma resection at the age of 2. After the surgery, he had not been followed up until his admission to our hospital. Computed tomography and MRI showed severe scoliosis of the thoracic spine and a paravertebral mass extending from the upper thoracic level to the level of renal arteries. Based on its radiological findings and the patient's history, the tumor was considered to be a recurrent ganglioneuroma. Paravertebral ganglioneuromas may cause progressive scoliosis, and a careful examination for patients with progressive scoliosis is mandatory.

Positional relationships among the celiac trunk, superior mesenteric artery, and renal artery observed from the intravascular space

To clarify the positional relationships among the celiac trunk (CT), the superior mesenteric artery (SMA), and the renal artery (RA) observed from the intravascular space to facilitate angiography. After excluding six cadavers in which anatomic variation was found in the CT or SMA and four cadavers in which a curvature of 5° or more was observed in the aorta from 30 Japanese donor cadavers, we used the abdominal aortas of the remaining 20 cadavers as specimens. We made an incision in the maximum longitudinal diameter of the left RA (Lt. RA) and acquired an image of the intravascular space using a digital camera. The distance between the inferior borders of each vessel was used as the hypotenuse of a right-angled triangle. Lines parallel to the longitudinal diameter of the aorta and those parallel to the transverse diameter of the right-angled triangle were measured by a computer and expressed as relative distance indexes using the transverse diameter of the aorta at the Lt. RA level as a reference point. The transverse diameter of the aorta was 20.1±2.9mm, and the relative distance indexes for longitudinal/transverse lines between each vessel were 1.61/0.35 between Lt. RA and CT, 0.84/0.48 between Lt. RA and SMA, and 0.78/0.13 between CT and SMA. The angle between the transverse axis of the abdominal aorta and the linear line connecting CT and SMA was 80.2°±9.4°. The branching point of CT in relation to SMA was located at the upper left in 80% (n=16), on the same line in 15% (n=3), and at the upper right in 5% (n=1) of the subjects. The relative distance indexes determined in this study will facilitate navigation during catheter insertion, particularly for those with little angiography experience, and thus reduce patient risk.

Treatment of a rapidly expanding thoracoabdominal aortic aneurysm after endovascular repair of descending thoracic aortic aneurysm in an old patient

BackgroundAortic pathology progression and/or procedure related complications following endovascular repair should always be considered mostly in older patients. We herein describe a hybrid procedure for treatment of rapidly expanding thoracoabdominal aneurysm following endovascular treatment of a descending thoracic aortic aneurysm in an older patient.Case presentationA 82-year-old man at 18 months after endovascular surgery for a contained rupture of descending thoracic aortic aneurysm revealed a type IV thoracoabdominal aneurysm with significant increase of the aortic diameters at superior mesenteric and renal artery levels. A hybrid approach consisting of preventive visceral vessel revascularization and endovascular repair of entire abdominal aorta was performed. Under general anaesthesia and by xyphopubic laparotomy, the infrarenal aneurysmatic aorta and common iliac arteries were replaced by a bifurcated woven prosthetic graf. From each of the prosthetic branches two reverse 14x7 mm bifurcated PTFE prosthetic grafts were anastomized to both renal arteries and to the celiac axis and superior mesenteric artery, respectively. Vessel ischemia was restricted to the time required for anastomosis. Three 10 cm Gore endovascular stent-grafts for a total length of 15 cm, were used. The overlapping of the stent-grafts was carried out from the bottom upwards, starting from the aorto-iliac prosthetic body up to the healthy segment of thoracic aorta, 40 mm from the previous stent-grafts.The patient was discharged on the 9th postoperative day.ConclusionThis technique offers the advantage of a less invasive treatment, reducing the risk of paraplegia, visceral ischaemia and pulmonary complications, mostly in older patients.

Characteristic of duplex doppler renal hemodynamics in patients with diabetes mellitus type 1

34 patients with diabetes mellitus type 1, who have been diagnosed diabetic nephropathy varying degrees of severity were examined. Assessment of renal hemodynamics with the help of ultrasound examination of the renal arteries with the use of the Doppler techniques. Revealed violations of the high-speed indicators at the level of interlobar and arc renal arteries, which as the progression of diabetic nephropathy will be revealed in the blood vessels of the kidney over a large caliber (segmental and stem). Significant difference of the resistance index compared with the control group were not found .

Pigtail catheter fracture and embolization into the abdominal aorta

Coronary angiography is a widely used diagnostic method for coronary artery disease. In clinical practice, although complications of the procedure often involve the vascular access point, there is no previous report of the fracture and embolization of the distal tip of a pigtail catheter. Herein, we present the case of a 51-year-old woman whose left ventriculography was interrupted by fracture of the curved tip of a pigtail catheter, which remained at the renal artery level in the abdominal aorta.

Short-Term Effects of Ankaferd Hemostat for Renal Artery Embolization: An Experimental Study

Renal artery embolization (RAE) is a minimally invasive therapeutic technique that is utilized in a number of disorders. Ankaferd is a novel hemostatic agent with a new mechanism of action independent of clotting factors. We used Ankaferd for RAE in a sheep model. Seven adult female sheep were included in the study. Selective renal arteriogram using 5-F diagnostic catheter was performed to make sure that each kidney was fed by a single renal artery and the animal had normal renal vasculature. Coaxial 2.7-F microcatheter was advanced to the distal main renal artery. Under fluoroscopic guidance, 2 mL of Ankaferd mixed with 2 mL of nonionic iodinated contrast agent was slowly injected. Fluoroscopy was used to observe the deceleration of flow and stagnation. Control renal angiograms were performed just after embolization. After the procedure, the animals were observed for 1 day and then sacrificed with intravenous sodium thiopental. The technical success was observed in seven of the seven animals.. After embolization procedure, none of the animals died or experienced a major systemic adverse event. On macroscopic examination of the embolized kidneys, thrombus at the level of main renal artery formed after Ankaferd embolization was more compact compared with the thrombi that was not Ankaferd-associated, which was observed elsewhere. Microscopically, majority of the renal tubular cells (80-90 %) were necrotic, and there was epithelial cell damage in a small portion of the cells (10-20 %). RAE was safe and effective in the short-term with Ankaferd in studied animals. Further studies should be conducted to better delineate the embolizing potential of this novel hemostatic agent.

Variations of Renal Artery in 820 Patients Using 64-Detector CT-Angiography

Purpose: Renal artery variations are important for clinical reasons. The aim of this study is to determine the originating level and variations of renal arteries with 64-channel multidetector computed tomography (MDCT). Materials and methods: In a university hospital, 820 patients who underwent MDCT angiography of the abdominal aorta were retrospectively evaluated. The number, early division (ED), and originating level of renal artery were evaluated retrospectively. Variations of the renal artery on both sides, the difference between the genders with variations of the renal artery, were compared with chi-square test. Results: Renal artery originating from the level of L1–L2 intervertebral disc was found in 37.0% and 38.9% of patients on the right and left sides, respectively. Renal artery variations, including extrarenal artery (ERA), were found in 27% and ED in 26.7% of the patients. Significant differences were found in ED and ERA prevalence for genders (p = 0.006 and p = 0.043, respectively). The prevalence of both variations is higher in males. Conclusions: An awareness of renal vascular variations is very important for both surgeons and radiologists. In this series, renal arterial variations were found in approximately one-fourth of the study population.

Elective visceral hybrid repair of type III thoracoabdominal aortic aneurysm

According to the classification given by Crawford et al. type III thoracoabdominal aortic aneurysm (TAAA) is dilatation of the aorta from the level of the rib 6 to the separation of the aorta below the renal arteries, capturing all the visceral branch of aorta. Visceral hybrid reconstruction of TAAA is a procedure developed in recent years in the world, which involves a combination of conventional, open and endovascular aortic reconstruction surgery at the level of separation of the left subclavian artery to the level of visceral branches of aorta. We presented a 75-years-old man, with elective visceral hybrid reconstruc tion of type III TAAA. Computerized scanning (CT) angiography of the patient showed type III TAAA with the maximum transverse diameter of aneurysm of 92 mm. Aneurysm started at the level of the sixth rib, and the end of the aneurysm was 1 cm distal to the level of renal arteries. Aneurysm compressed the esophagus, causing the patient difficulty in swallowing act, especially solid food, and frequent back pain. From the other comorbidity, the patient had been treated for a long time, due to chronic obstructive pulmonary disease and hypertension. In general endotracheal anesthesia with epidural analgesia, the patient underwent visceral hybrid reconstruction of TAAA, which combines classic, open vascular surgery and endovascular procedures. Classic vascular surgery is visceral reconstruction using by-pass procedure from the distal, normal aorta to all visceral branches: celiac trunk, superior mesenteric artery and both renal arteries, with ligature of all arteries very close to the aorta. After that, by synchronous endovascular technique a complete aneurysmal exclusion of thoracoabdominal aneurysm with thoracic stent-graft was performed. The postoperative course was conducted properly and the patient left the Clinic for Vascular Surgery on postoperative day 21. Control CT, performed 3 months after the surgery showed that the patient's vascular status was uneventful with functional visceral by-pass and with good position of a stent-graft without a significant endoleak. Visceral hybrid reconstruction represents a complementary surgical technique to that with open reconstruction of TAAA. This approach is far less traumatic to a patient, and is especially important in patients with lot of comorbidities, because there is no need for thoracotomy, and ischemic-reperfusion injury of the body is reduced to a minimum.

Influence of Respiratory Cycle on Proximal Renal Artery Motion: An Angiographic Study in Patients Undergoing Endovascular Aneurysm Repair

Background : The purpose of our study was to evaluate the influence of respiratory cycle on proximal renal artery (RA) motion in twenty consecutive patients with abdominal aneurysm and the potential impact on endograft deployment during endovascular aneurysm repair (EVAR).Methods : Prior to the device introduction, a preoperative angiography to define the location of the RAs was performed by a calibrated pigtail catheter. A measuring tape on the table served as the reference point for all measurements. Images of RA levels were acquired during expiration (E) and inspiration (I) cycles. In order to have homogenous comparative values for each patient during inhalation, the anaesthesiologist maintained a controlled inspiration with a uniform pressure of 30 cm of water. Motion of the RAs was defined as the changes in distance between E and I measures, adjusted to the calibrated pigtail.Results : The median right proximal RA motion was 3.0 mm (IQR 2.4 mm; range: 0 to 5.6 mm). The median left proximal RA motion was 3.1 mm (IQR 2.2 mm; range: 0.54 to 5.6 mm). The current results demonstrate the proximal RAs motion during breath with a median magnitude of 3 mm, without significant differences between both RA (P = .83). Conclusion : Our data confirm the RAs motion during respiratory cycle. More than the predictive absolute value of the RA motion between inspiratory and expiratory phases, it is the motion itself which is important. This unrecognized condition, even if it interests only a minority of patients, could potentially have clinical disastrous consequences: potential stenosis or covering of RAs.

A Case of Takayasu's arteritis with Acute Heart Failure Due to Severe Aortic Regurgitation

On April 27, 2011, a 42-year-old woman visited our outpatient clinic complaining of dyspnea. Conventional examinations including echocardiography (EC) revealed acute heart failure due to severe aortic regurgitation (AR). The laboratory data showed systemic inflammation (C-reactive protein 4mg/dL). After her emergent admission, contrast-enhanced computed tomography detected the dissection of abdominal aorta at the level of superior mesenteric artery and left renal artery and total occlusion of left subclavian artery, being compatible with approximately 60mmHg lower blood pressure in her left arm than in right arm.

Modified quadruple inversion recovery prepulse for arterial spin labeling angiography without the need of subtraction

Arterial Spin Labeling (ASL) is a well-known technique that allows the non-invasive acquisition of angiograms without the need of a contrast agent [1][2]. ASL angiography is still clinically underused because of several challenges [3]: ASL requires two acquisitions (labeled and non labeled dataset) thereby doubling scan time. The need of subtraction increases the sensitivity to spatial misregistration and the need of the choice of an optimal inversion delay for best blood-to-background contrast introduces some “operator dependence”. An alternative technique not requiring image subtraction has been proposed (Figure ​(Figure1)1) [4]. This approach is based on a double inversion (DIR-ASL) prepulse and provides good background suppression if the surrounding tissues have similar T1 values (Figure ​(Figure1).1). However, DIR-ASL has only one optimal inversion delay and thus there is a trade-off between background suppression and visualized vessel extent. Our goal was to develop an ASL technique with improved background suppression and without the need of subtraction. Figure 1 Double inversion bright-blood MR angiography sequence Methods The proposed method is a modified Quadruple Inversion Recovery [5] sequence (mQIR-ASL), which provides excellent background signal suppression according to our simulations (Figure ​(Figure2).2). The first pair of RF pulses consists of a non-selective inversion RF pulse followed by a selective reinversion pulse and a navigator-restore pulse. The second pair of RF pulses consists of a non-selective inversion pulse followed by a navigator-restore pulse. With this configuration, the upstream labeled blood only “experiences” the second non-selective inversion pulse, while the static tissue “experiences” both non-selective inversion pulses. With the right choice of TI1 and TI2, signal from static tissue can be suppressed over a wide T1 range while maintaining the signal of target blood (Figure ​(Figure2).2). This pre-pulse was implemented on a 3T Achieva Gyroscan MR scanner (Philips Healthcare, Best, NL) and tested in 5 subjects. Figure 2 mQIR-ASL sequence, NS: Adiabatic Non-Selective Inversion Pulse. R: Selective Inversion Pulse, NR: Navigator Restore Pulse, N: Naviagtor, AQ: Acquisition Results Renal arteries including small branches were successfully visualized in all subjects with excellent suppression of background (Figure ​(Figure33,​,4).4). The plan scan and the maximum projection angiogram (MIP) are shown in Figure ​Figure3.3. Improved background suppression was observed with mQIR-ASL compared to DIR-ASL (Figure ​(Figure44). Figure 3 In vivo result with mQIR-ASL (TR/TI1/TI2 = 1000/480/162 ms). A- Planning procedure; B- and C- MIPs of aorta and renal arteries Figure 4 Transverse slice at the renal artery level demonstrating improved background suppression with mQIR-ASL (TW/TI1/TI2 = 480/162 ms) © compared with DIR-ASL (Inversion time (TI) of 300 ms (A) and 600 ms (B)). L=liver; M=muscle; K=kidneys. Conclusions We demonstrate a new ASL approach for non-contrast enhanced MR angiography with excellent background tissue suppression and without the need of subtraction. In comparison to DIR-ASL, mQIR-ASL yielded better background suppression and improved vessel delineation.

Clinical Practice Guidelines for Endovascular Abdominal Aortic Aneurysm Repair: Written by the Standards of Practice Committee for the Society of Interventional Radiology and Endorsed by the Cardiovascular and Interventional Radiological Society of Europe and the Canadian Interventional Radiology Association

From the Department of Radiology, Division of Vascular Imaging and Intervention (T.G.W., S.P.K., K.Y., S.W.), Massachusetts General Hospital, Boston, Massachusetts; Department of Medical Imaging (S.K.), Scarborough General Hospital, Toronto, Ontario, Canada; Department of Interventional Radiology (P.D.), West Allis Memorial Hospital, Milwaukee, Wisconsin; Department of Radiology, Division of Interventional Radiology (B.J.D.), University of Maryland Medical Center, Baltimore, Maryland; Department of Radiology (S.C.R.), University of California San Diego Medical Center, San Diego, California; and Department of Radiology (J.F.C.), Geisinger Health System, Danville, Pennsylvania. Received May 4, 2010; final revision received May 24, 2010; accepted July 11, 2010. Address corre-

INFLUENCE OF DIETARY SODIUM ON RENAL NITRIC OXIDE INHIBITION AND RENAL BLOOD FLOW IN HYPERTENSIVE CAUCASIANS: 2D.02

Objective: Nitric oxide (NO) plays an important role in renal hemodynamics. We investigated the influence of dietary sodium on renal blood flow and renal NO-synthesis, by determining renal levels of NO inhibitors asymmetric dimethylarginine (ADMA) and L-NG-monomethylarginine (L-NMMA), ADMAs isoform symmetric dimethylarginine (SDMA), NO-precursor l-arginine and NO co-product citrulline. Design and Methods: We included 133 moderately hypertensive patients (all Caucasian) who were scheduled for renal angiography on suspicion of renal artery stenosis, mostly because of resistant hypertension. Patients with renal artery stenosis, fibromuscular dysplasia or proteinuria were excluded. Patients were assigned to adhere to either a sodium-rich diet (>200 mmol/24 h) (n = 56) or a sodium-restricted diet (<55 mmol/24 h) (n = 57) during the week preceding the study. All antihypertensive medication was discontinued 3 weeks before the study. After an overnight fast, patients consecutively underwent selective blood sampling from the aorta and both renal veins, renal flow measurements using 133Xenon washout and renal angiography. In the obtained blood samples we determined levels of ADMA, SDMA, L-NMMA, l-arginine and citrulline (all using high-performance liquid chromatography) and levels of creatinine and renin (using standard methods). 24 h urine was collected to determine urinary sodium excretion. Results: There were no significant differences in renal arterial and renal venous levels of ADMA, SDMA, L-NMMA, l-arginine, citrulline, creatinine and renin between both groups. Neither were there differences in blood pressure or renal blood flow. Renal elimination of ADMA and L-NMMA however, was significantly lower in the high sodium group compared to the low sodium group (11.6% vs. 14.6 %; p = 0.031 and 0.7% vs. 7.6%; p = 0.033 respectively). There was no significant correlation between 24 h urinary sodium excretion and any of the studied parameters. Conclusion: In hypertensive Caucasians, short-term moderate-high dietary sodium does not influence renal blood flow or intrarenal levels of arginines. However, renal elimination of ADMA and L-NMMA is significantly lower in comparison to a low sodium diet, which may result in long-term renal NO-inhibition.

Acute Aortic Occlusion Due to False-Lumen Expansion After Repair of Abdominal Aortic Rupture in Type B Acute Aortic Dissection

We describe a patient with aortic occlusion due to false-lumen expansion after repair of abdominal aortic rupture in acute type B aortic dissection. A 70-year-old man presented to a nearby hospital with severe lower back pain, and was subsequently referred to our hospital with a diagnosis of abdominal aortic rupture. Computed tomography scanning on admission revealed type B aortic dissection with concomitant false-lumen rupture at the level of pre-existing infrarenal abdominal aortic aneurysm. The patient underwent abdominal aortic replacement with the true lumen reconstructed using a bifurcated knitted Dacron graft. On postoperative day 2, the patient developed severe lower body ischemia. Computed tomography scanning revealed complete true-lumen occlusion at the renal artery level because of false-lumen expansion. The patient underwent open fenestration by opening the bulging flap with a transverse graftotomy distal to the proximal graft anastomosis. After fenestration, the patient developed severe metabolic complications (i.e., myonephropathic-metabolic syndrome) and died a day later of cardiac arrest resulting from hyperkalemia. Abdominal aortic replacement with true-lumen reconstruction in patients with abdominal aortic rupture in type B acute aortic dissection could also lead to acute aortic occlusion due to re-dissection or true-lumen compromise accompanying retrograde propagation of false-lumen thrombosis. This lethal sequela after true-lumen reconstruction might be prevented by an adjuvant procedure such as concomitant fenestration.

Intraaortic Pulse Pressure Amplification in Subjects at High Coronary Risk

Peripheral (brachial) pulse pressure normally exceeds central (aortic) pulse pressure but is a less powerful predictor of cardiovascular risk. The difference between the 2 variables, called pulse pressure amplification, has never been specifically studied between the proximal and distal aorta in coronary patients. Our goal was to determine aortic pulse pressure amplification in subjects at high coronary risk, with emphasis on associated renal and inflammatory factors. Blood pressure was measured invasively in the ascending aorta, abdominal aorta (at the level of kidneys), and iliac artery in 101 subjects (mean age, 63+/-11 years; 61 men) undergoing coronary angiography. Independently of age, sex, and the presence of coronary stenosis, the increase of pulse pressure between the ascending and terminal aorta was over 10 mm Hg (P<0.001), whereas mean blood pressure remained unchanged. Pulse pressure amplification did not differ significantly between patients with and without coronary artery stenosis. Irrespective of confounding variables, high pulse pressure measured in the ascending aorta and at the level of renal arteries (but not in the iliac artery) was independently related to proteinuria. The increase in pulse pressure from the ascending aorta to the renal level was negatively associated with leukocyte count, even after multivariate adjustment (beta coefficient, -0.19; 95% CI, -0.39 to 0.0; P<0.05). Increased plasma creatinine and aortic pulse wave velocity were independently and positively correlated (beta coefficient, 0.36; CI, 0.18 to 0.54; P<0.001). Independently of coronary atherosclerosis, aortic pulse pressure integrates the predictive value of aortic, inflammatory, and renal factors.

Relation of Common Carotid Artery Lumen Diameter to General Arterial Dilating Diathesis and Abdominal Aortic Aneurysms: The Tromso Study

In a cross-sectional, population-based study in Tromsø, Norway, the authors investigated correlations between lumen diameter in the right common carotid artery (CCA) and the diameters of the femoral artery and abdominal aorta and whether CCA lumen diameter was a risk factor for abdominal aortic aneurysm (AAA). Ultrasonography was performed in 6,400 men and women aged 25-84 years during 1994-1995. An AAA was considered present if the aortic diameter at the level of renal arteries was greater than or equal to 35 mm, the infrarenal aortic diameter was greater than or equal to 5 mm larger than the diameter of the level of renal arteries, or a localized dilation of the aorta was present. CCA lumen diameter was positively correlated with abdominal aortic diameter (r = 0.3, P < 0.01) and femoral artery diameter (r = 0.2, P < 0.01). In a multivariable adjusted model, CCA lumen diameter was a significant predictor of AAA in both men and women (for the fifth quintile vs. the third, odds ratios were 1.9 (95% confidence interval: 1.2, 2.9) and 4.1 (95% confidence interval: 1.5, 10.8), respectively). Thus, CCA lumen diameter was positively correlated with femoral and abdominal aortic artery diameter and was an independent risk factor for AAA.

Experience With the Endologix Powerlink Endograft in Endovascular Repair of Abdominal Aortic Aneurysms With Short and Angulated Necks

Endovascular aortic aneurysm repair (EVAR) for anatomically suitable abdominal aortic aneurysms (AAAs) has gained wide acceptance in the past decade, and EVAR for anatomically challenging or unsuitable AAAs such as short and angulated neck AAAs has become a hotly debated subject. The objective of this study is to summarize the unique experience of EVAR for short / angulated neck AAAs with Powerlink unibody bifurcated stent-graft. Data were retrospectively analyzed from 519 patients in our single unit from February 1999 to December 2007 who underwent EVAR using the Powerlink endograft, and had short or angulated necks. Short neck was defined as < or = 15 mm for the infrarenal neck length, and it was divided into 2 groups: Group A (short neck), 54 cases with the length 11 to 15 mm; and Group B (very short neck), 26 cases with the length < or = 10 mm. Angulated neck of 37 cases which was defined as > or = 60 degrees angulation between the longitudinal axis of infrarenal aorta and the aneurysm. The unique strategy of treating short / angulated neck AAAs is to build up the endoluminal exclusion system from the native aortic bifurcation to the renal artery level with suprarenal fixation. The Powerlink unibody bifurcated stent graft was implanted anatomically fixed on the aortic bifurcation and a long suprarenal cuff was built up to the renal arteries. A Palmaz stent can be used for proximal fixation and sealing enhancement in the most challenging necks. The follow-up imaging was performed at 1 month, 6 months, and yearly thereafter. The technical success rate was 97.4% (114/117). Intraoperative complications included 3 conversions due to delivery access problems, 6 proximal type I endoleaks, and 5 type II endoleaks. The 30-day mortality was 1.7% (2/117). The 2.6-year follow-up showed 4 (3.4%) proximal type I endoleaks, which were revised with proximal cuff and/or Palmaz stent. Limb occlusion occurred in 2 cases, and the total re-intervention rate was 5.3%. Three (2.6%) type II endoleaks were left in observation. There were 3 (2.6%) partial renal infarctions, no stent-graft distal migration, and no post-EVAR ruptures. Our experience demonstrates that building up the endoluminal exclusion system from the abdominal aortic bifurcation to the renal artery level using the Powerlink fully supported unibody bifurcated stent-graft with a long suprarenal cuff, and a Palmaz stent when needed, proved safe and effective in treating AAAs with short and angulated necks.