Artery And Vein Research Articles

Comparison of renal function between the artery and vein clamp and artery-only clamp in robot-assisted partial nephrectomy for moderate- to high-complexity renal masses: A propensity-matched study.

Artery and vein (AV) clamps can control venous bleeding in the surgical field and prevent carbon dioxide embolism, especially when large veins are expected to open. However, whether AV clamps cause more renal damage than artery-only (AO) clamps remains unclear. This study aimed to compare renal function and blood loss in surgeries using AO and AV clamps based on high RENAL nephrometry scores (RNS) in robot-assisted partial nephrectomy (RAPN). We retrospectively analyzed the medical records of 500 patients who underwent RAPN between March 2016 and December 2021. We performed 1:1 propensity matching for these patients. A total of 340 patients with pathological malignancies who were followed up for at least 12 months were included in this analysis. A total of 291 patients with AO clamping and 49 patients with AV clamping were included. Overall, the AV clamp group had higher total RNSs and larger diameters than the AO clamp group. Propensity score-matched analysis included 37 patients in each clamp group. The median warm ischemia times of the AV and AO clamps were 25 and 22 min, respectively, with no significant difference. There were no statistically significant differences between the groups in the amount of blood loss, rate of acute kidney injury (AKI), or renal function at 1, 3, or 12 months post-RAPN. Compared with the AO clamp, the AV clamp did not have a detrimental impact on blood loss or renal dysfunction. Consequently, AV clamps may be considered for patients presenting with moderate-to-high-complexity RNSs.

Concurrent OCT and OCT angiography of retinal neurovascular degeneration in the 5XFAD Alzheimer's disease mice.

.Significance: As one part of the central nervous system, the retina manifests neurovascular defects in Alzheimer’s disease (AD). Quantitative imaging of retinal neurovascular abnormalities may promise a new method for early diagnosis and treatment assessment of AD. Previous imaging studies of transgenic AD mouse models have been limited to the central part of the retina. Given that the pathological hallmarks of AD frequently appear in different peripheral quadrants, a comprehensive regional investigation is needed for a better understanding of the retinal degeneration associated with AD-like pathology.Aim: We aim to demonstrate concurrent optical coherence tomography (OCT) and OCT angiography (OCTA) of retinal neuronal and vascular abnormalities in the 5XFAD mouse model and to investigate region-specific retinal degeneration.Approach: A custom-built OCT system was used for retinal imaging. Retinal thickness, vessel width, and vessel density were quantitatively measured. The artery and vein (AV) were classified for differential AV analysis, and trilaminar vascular plexuses were segmented for depth-resolved density measurement.Results: It was observed that inner and outer retinal thicknesses were explicitly reduced in the dorsal and temporal quadrants, respectively, in 5XFAD mice. A significant arterial narrowing in 5XFAD mice was also observed. Moreover, overall capillary density consistently showed a decreasing trend in 5XFAD mice, but regional specificity was not identified.Conclusions: Quadrant- and layer-specific neurovascular degeneration was observed in 5XFAD mice. Concurrent OCT and OCTA promise a noninvasive method for quantitative monitoring of AD progression and treatment assessment.

Effect of unilateral renal ischemia on the contralateral kidney assessed by Caspase 3 expression.

BackgroundStudies have demonstrated with histological analysis and Doppler flow measurement analysis that unilateral renal ischemia, which is performed in some surgeries, interfered with the contralateral kidney, identifying the phenomenon of kidney-kidney crosstalk.ObjectivesTo identify the effects on the ischemic and contralateral kidney of renal ischemia induced by two types of clamping technique by analyzing the volume of kidney cells positive for Caspase 3.MethodsSixteen pigs were divided into 2 groups, as follows: A (n = 8) – clamping of left renal artery only and AV (n = 8) – clamping of left renal artery and vein. Immunohistochemical analyses (anti Caspase 3) were conducted with biopsy specimens collected from the ischemic and contralateral kidney at 0, 30, 60, and 90 minutes of ischemia and morphometric analysis was performed, taking the mean to represent the volume of the Caspase 3 positive area (%).ResultsMorphometric analysis of specimens collected at 30, 60, and 90 minutes of ischemia showed that the mean area marked for Caspase 3 was statistically larger in the contralateral kidney than the ischemic kidney in both groups: clamped renal artery (A) and clamped renal artery and vein (AV). Comparing the ischemic and contralateral kidney, there was no statistically significant difference in the area marked for Caspase 3 between the two types of clamping.ConclusionsIn the experimental model of unilateral renal ischemia, the non-ischemic kidney exhibited cell damage, demonstrated by Caspase 3 expression. The type of hilum clamping does not appear to influence the area marked for Caspase 3.

Comparison of clamping strategies in minimally invasive partial nephrectomy for cT1 tumors

Objectives To determine whether artery only (AO) clamping promises any advantage over artery and vein (AV) clamping in patients undergoing partial nephrectomy with minimally invasive surgical techniques. Material and methods We retrospectively analyzed the data of 68 partial nephrectomy patients who were treated with minimally invasive techniques (robot-assisted laparoscopic or pure laparoscopic) for solitary, unilateral, cT1 renal masses during the period of 2008–2019 in a single institution. Patients were divided into two groups according to clamping strategy (AO and AV). The two groups were compared to each other in terms of perioperative outcomes and long-term functional results. Results The mean patient age and median follow-up period were 56.8 ± 10.8 years and 13.5 (9–44.5) months, respectively. Warm ischemia time, estimated blood loss, transfusion rate and length of hospital stay were similar between the two groups, while operative time was significantly higher in the AO clamping group (p = .726, p = .604, p = .675, p = .103, and p = .038, respectively). Patients who underwent AV clamping had a significantly lower estimated glomerular filtration rate (eGFR) and higher chronic kidney disease rates six months postoperatively (p = .001 and p = .044, respectively) and at the last follow-up (p = .020 and p = .048, respectively). The percentage of eGFR change at six months and the last follow-up was higher in the AV clamp group but the difference was not statistically significant (p = .056 and p = .082, respectively). Conclusions Our findings suggest AO clamping is safe and comparable to AV clamping. In our study, AO clamping was found to be superior to AV in terms of long-term eGFR preservation.

Comparison of Hilar Clamping Techniques in Partial Nephrectomy: Is Artery Only Clamping Beneficial?

Hilar clamping is widely adopted in open partial nephrectomy, which is a treatment option for small renal cancer to reduce blood loss and improve surgical exposure, but whether to clamp either only artery or both artery and vein remains controversial. The purpose of this study is to determine whether artery only (AO) clamping is more beneficial than en bloc clamping by comparing perioperative variables in patients who underwent partial nephrectomy with either AO clamping or en bloc clamping. Eighty-eight patients with T1 renal tumor who underwent open partial nephrectomy with either AO or en bloc clamping between 2015 and 2018 at our institution were enrolled. They were randomly divided into two groups: AO group (n = 43) and artery and vein (AV) group (n = 45). Renal function was evaluated by serum creatinine (SCr) and differential renal function as determined by mercaptoacetyltriglycine renogram. AO clamping was associated with less total renal functional decrease until postoperative 7th day (P < 0.05). After postoperative 15th day, however, there was no significant difference in total renal functional impairment between AO and AV groups. There was also no significant difference in differential renal function change. Furthermore, AO clamping caused more blood loss and hemoglobin (Hb) decrease than en bloc clamping (P < 0.05). AO clamping is no more beneficial than en bloc clamping in partial nephrectomy, presenting with not significantly better long-term postoperative renal function than en bloc clamping.

Characterization of arteriovenous identity in the developing neonate mouse retina

The murine retina has become an ideal model to study blood vessel formation. Blood vessels in the retina undergo various processes, including remodeling and differentiation, to form a stereotypical network that consists of precisely patterned arteries and veins. This model presents a powerful tool for understanding many different aspects of angiogenesis including artery and vein (AV) cell fate acquisition and differentiation. However, characterization of AV differentiation has been largely unexplored in the mouse retinal model. In this study, we describe the expression of previously established AV markers and assess arteriovenous acquisition and identity in the murine neonatal retina. Using in situ hybridization and immunofluorescent antibody staining techniques, we analyzed numerous AV differentiation markers such as EphB4-EphrinB2 and members of the Notch pathway. We find that at postnatal day 3 (P3), when blood vessels are beginning to populate the retina, AV identity is not immediately established. However, by P5 expression of many molecular identifiers of arteries and veins become restricted to their respective vessel types. This molecular distinction is more obvious at P7 and remains unchanged through P9. Overall, these studies indicate that, similar to the embryo, acquisition of AV identity occurs in a step-wise process and is largely established by P7 during retina development.

MP64-02 CLAMPING TECHNIQUE IN PARTIAL NEPHRECTOMY HAS MINIMAL LONG TERM EFFECT ON RENAL FUNCTION IN PATIENTS UNDERGOING A ROBOTIC ASSISTED SURGERY: MINIMUM 6 MONTH FOLLOW UP

You have accessJournal of UrologyKidney Cancer: Localized V1 Apr 2014MP64-02 CLAMPING TECHNIQUE IN PARTIAL NEPHRECTOMY HAS MINIMAL LONG TERM EFFECT ON RENAL FUNCTION IN PATIENTS UNDERGOING A ROBOTIC ASSISTED SURGERY: MINIMUM 6 MONTH FOLLOW UP Louis Spencer Krane, Jason Sandberg, Ted B. Manny, and Ashok Kumar Hemal Louis Spencer KraneLouis Spencer Krane More articles by this author , Jason SandbergJason Sandberg More articles by this author , Ted B. MannyTed B. Manny More articles by this author , and Ashok Kumar HemalAshok Kumar Hemal More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.1919AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Recent publications have encouraged use of unclamped robotic assisted partial nephrectomy (RPN) to improve long-term renal function and prevent chronic kidney disease (CKD). We performed many of these procedures in a non-randomized fashion and then evaluated both early and long-term renal functional outcomes. METHODS From a review board approved, prospectively maintained database we included all patients and subdivided these into either a Artery and Vein (AV), Artery Only (AO) or unclamped procedure. Patients were considered having acute kidney injury (AKI) with a 25% decrease in eGFR during hospitalization. Worsening of long term renal function was defined as progression to higher CKD stage. eGFR was calculated using the MDRD equation. Patients with solitary kidneys were excluded form analysis. ANOVA analysis was used for continuous variables, chi-squared for nominal variables, logistic regression for AKI during hospitalization and Cox proportion hazards model created for risk of CKD progression. RESULTS We identified 252 patients with at least 6 month follow up renal functional outcomes following RPN (Median 19 months). In patients who had clamped procedure, median ischemia time was 18 minutes (IQR 14 – 26). Demographic results are summarized in Table 1. 51 (20%) of patients had AKI during hospitalization. Using logistic regression analysis with a model including preoperative GFR, clamping technique, age, and tumor size, only increasing tumor size (p = 0.02) and preoperative GFR (p=0.008) was associated with AKI during hospitalization. 23 (9%) of patients had CKD progression. Univariate cox proportion hazards for CKD progression is demonstrated in Table 2. CONCLUSIONS When performing robotic assisted partial nephrectomy long-term renal function appears unaffected by technique of hilar clamping in patients with contralateral functional renal units. We advocate the physician use the safest technique for renal vascular control, and individualize this for each patient. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e700-e701 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Louis Spencer Krane More articles by this author Jason Sandberg More articles by this author Ted B. Manny More articles by this author Ashok Kumar Hemal More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...

Renal Oxygenation During Partial Nephrectomy: A Comparison Between Artery-Only Occlusion Versus Artery and Vein Occlusion

During partial nephrectomy (PN), artery-only (AO) occlusion may mitigate ischemia/reperfusion injury because of retrograde venous flow. Using digital light processing-hyperspectral imaging (DLP(®)-HSI), we compared renal oxygenation during AO vs artery and vein (AV) occlusion in patients undergoing PN. Thirty-seven patients who were undergoing complex open PN (median R.E.N.A.L. nephrometry of 8) at our institution underwent renal oxygenation assessment using DLP-HSI. Percent renal parenchymal oxyhemoglobin (%HbO2) during AO vs AV occlusion was recorded and its correlation with postoperative estimated glomerular filtration rate (eGFR) was investigated using Pearson correlation. AO and AV occlusion was performed in 12 and 25 patients, respectively. Comparing AO vs AV, mean ischemia time was 41 vs 35 minutes (P=0.02). The %HbO2 at baseline was 73.6% vs 71% (P=0.23). After hilar occlusion, %HbO2 quickly reached an "ischemic plateau" in both groups, with mean ischemic %HbO2 measures of 59.7% vs 62.2% (P=0.19). In the AV group, a lower mean ischemic %HbO2 was associated with lower eGFR at the most recent follow-up (r=0.46, P=0.02) and remained significant on multivariable analysis (odds ratio 2.31; 95% confidence interval 0.29-4.32; P=0.03). In this pilot clinical study, renal oxygenation profiles during PN as assessed by DLP-HSI were similar for AO vs AV occlusion. Significant retrograde venous oxygen delivery using an AO occlusion technique could not be demonstrated. There was also no renal functional advantage for AO occlusion in this population of difficult PN where prolonged ischemia times may have mitigated any advantage. Further study in cases with shorter ischemia times is warranted.

Different from Renal Artery Only Clamping, Artery and Vein Clamping Causes a Significant Reduction in Number of Rat Glomeruli During Warm Ischemia

To evaluate glomerular injury in the rat model during renal warm ischemia (WI), comparing artery and vein (AV) clamping with artery only (AO) clamping. Twenty-four adult male rats underwent 60 minutes of renal WI in the left kidney. The animals were divided into three groups: AV clamping, AO clamping, and Sham surgery. After 30 days, the animals were euthanized, and both kidneys were processed for paraffin embedding and stained with hematoxylin and eosin. Glomerular volume density (Vv[glom]), mean glomerular volume (MGV), and number of glomeruli per mm(3) (Nv[glom]) were evaluated in the renal cortex. The Vv[glom] was reduced in the left kidney (ischemic) when compared with the right kidney in both AV and AO groups by 11.1% and 35.4%, respectively; however, the difference was significant only in the AV group. The Nv[glom] was reduced in the left kidney when compared with the right kidney in both AV and AO groups by 11.6% and 31.4%, respectively; nevertheless, the difference was significant only in the AV group. The MGV of left and right kidneys was the same in both Sham and AO groups and was diminished by 6.7% in the AV group-not significant. AV clamping causes a significant decrease in the number of glomeruli in the rat model, while AO clamping reduces the glomerular number, but not significantly. To minimize renal injury, AO clamping may be preferred over AV clamping when WI is necessary in patients with previously compromised renal function.

Portal hypertension caused by postoperative superior mesenteric arteriovenous fistula

Arteriovenous fistula of the superior mesenteric blood vessels is a rare complicaton in abdominal surgery. We presented a 49-year-old man with cramp-like abdominal pain, abdominal distension and weight loss symptoms, with a history of previous small bowel resection and right colectomy, due to Crohn disease, 16 years ago. Clinical examination revealed a paraumbilical pulsation with systolic murmur and thrill. Ultrasonography and computed tomography revealed cystic dilatation of the superior mesenteric vein, hepatomegaly and ascites. Upper endoscopy revealed grade I esophageal varices with portal hypertensive gastropathy. The diagnosis of arteriovenous fistula between superior mesenteric artery and vein was confirmed by angiogram of the superior mesenteric vessels and resection of the fistula was performed. Control examination after nine months showed no signs of portal hypertension. Early diagnosis and treatment of mesenteric blood vessel arteriovenous fistula prevents portal hypertension development and its complications.

First Prize: Characterization of Renal Ischemia Using DLP®Hyperspectral Imaging: A Pilot Study Comparing Artery-Only Occlusion Versus Artery and Vein Occlusion

Renal artery-only (AO) occlusion, as opposed to artery and vein (AV) occlusion, has demonstrated some benefit in reducing renal insufficiency during warm ischemia. In this pilot study, we used digital light projection hyperspectral imaging (HSI) to construct a "real time" tissue oxygenation "map" to determine whether there are differences in renal tissue oxygenation during vascular occlusion with AO vs AV. Renal vascular occlusion with either AO or AV was performed for 60 minutes in seven porcine renal units. Using HSI, the percentage of oxyhemoglobin (%HbO(2)) in the renal cortex was determined at 4-minute increments throughout the ischemic period and for 30 minutes after reperfusion. Average baseline %HbO(2) in all animals was approximately 70%. After vascular occlusion in both cohorts, %HbO(2) decreased by one third within 2 to 5 minutes, with a gradual decline in %HbO(2) over the remaining 55 minutes. Oxyhemoglobin profiles for AO and AV occlusion diverged significantly between 16 and 24 minutes after vascular occlusion (P = 0.0001 and 0.036, respectively), with a merging of the two curves occurring after approximately 36 minutes (P = 0.093). During reperfusion, average %HbO(2) improved to 72.4% after 25 to 30 minutes. In this pilot study, we demonstrate that renal tissue oxygenation drops rapidly after occlusion of the renal vasculature and returns to near baseline 30 minutes after reperfusion. In the porcine model, the %HbO(2) differs significantly between AO and AV occlusion for up to 35 minutes after ischemia onset, indicating a possible "ischemic window" in which AO occlusion may provide benefit over AV occlusion.

Superior Mesenteric Artery Aneurysm in a Multi Aneurysmal Disorder Associated with a Distal Arteriovenous Fistula

IntroductionA superior mesenteric artery aneurysm (SMAA) is arare and most often isolated event that has variouscauses. This is, as far as we know, the first reportedcase of an SMAA, treated surgically by resection andreplacement, and associated with a distal arteriove-nous fistula responsible for arterial enlargement andmultiple arterial aneurysms.Case ReportA 60-year-old man with no specific cardiovascular riskfactors (coronary symptoms, valve disorder, or cardiacmedication) or past medical or surgical history wasadmitted to the cardiology unit with severe heartfailure, acute dyspnea and peripheral edema. Trans-thoracic echocardiography revealed right ventriculardilatation (70 mm in diastole) with functional tricus-pid regurgitation. The cardiac failure was treated andthe patient rapidly recovered. Whilst in hospital, alarge distal arteriovenous fistula was found in the leftankle. The patient reported that when he was 9 yearsold the left ankle was injured in a bicycle accident andbled profusely. The wound was compressed to stop thebleeding and the skin was directly sutured. The distalarteriovenous fistula related to the injury remainedundiagnosed at the time and developed over the next50 years. In a patient with no history of valve disordersor heart disease the arteriovenous fistula was pre-sumed responsible for a case of heart failure whichresponded rapidly to appropriate medication.Following successful cardiac management thepatient was transferred to the vascular surgery unitfor investigation and treatment of the distal arteriove-nous fistula. Angiography showed a distal arteriove-nous fistula between the left posterior tibial artery andvein. The distal arterial tree was normal. The angio-gram also showed arteriomegaly involving the entireleft arterial network with a popliteal aneurysmmeasuring 35 mm in diameter, and a dilated super-ficial femoral artery which measured 17 mm proxi-mally and 24 mm in the adductor hiatus (Fig. 1).Arteriomegaly was associated with multiple aneur-ysm formation including an aneurysm of the leftcommon iliac artery (35 mm), an abdominal aorticaneurysm (55 mm) and an aneurysm of the right renalartery (20 mm). Before managing the aneurysms wedecided to treat the arteriovenous fistula with doubleembolization (arterial and venous) under local anes-thetic. First, the posterior tibial artery adjacent to thearteriovenous fistula was embolized using three Cookcoils (MREY EMBOLIZATION COIL

Low nutrition of ewes in early pregnancy and the residual effect on the offspring

SUMMARYMature Merino ewes (n = 500) were allotted at random to embryo removal (day 35; day 0 = day of oestrus detection), foetal removal (day 90) or lambing groups. These groups were further randomly divided into four single-sire mating groups. From day 1 until day 35 ewes were individually penned and fed either 50 or 150% of a maintenance ration (0·5 M or 1·5 M respectively). At day 35 single embryos were removed from anaesthetized ewes in the embryo removal group and all other ewes were endoscoped to confirm pregnancy. These ewes were then returned to pasture. Plasma samples were taken from all ewes on days 2, 4, 16, 23, 30 and 35 for analysis of glucose concentration. At day 90, ewes allotted to the foetal removal group were anaesthetized and plasma samples were obtained from the ewe's jugular vein and the umbilical arteryand vein. Ewes were then hysterectomized and the foetus was weighed and measured. Functional cotyledons were dissected from the uterus and chorio-allantois and all tissues were weighed. The remaining ewes (lambing group) were supervised at lambing and lambs were identified, weighed and measured.Live-weight changes from weaning and wool production and quality were measured in ewe and ram lambs at their first shearing (11 months of age). Ovulation rates in the first two oestrous seasons of the ewes and wool production at their second shearing (2 years of age) were also measured.During the 35-day treatment period, mean live-weight changes of ewes were –4·9 and + 1·8 kg in the 0·5 M and 1·5 M groups respectively. Pregnancy rates were similar in both groups but embryos from 0·5 M ewes weighed less than those from 1·5 M ewes (1·7 ± 0·04 ν. 1·9 ± 0·05 g; P &lt; 0·005). Foetuses taken at 90 days from 0·5 M ewes were smaller than those from 1·5 M ewes but these differences reached significance (P &lt; 0·025) only in the measurement of chin–crown length (8·0 ± 0·09 ν. 7·6 ± 0·11 cm). Correlations between foetal weight and total cotyledon weight, chorio-allantoic weight and empty uterine weight were all significant. Plasma glucose concentrations of ewes in the 0·5 M group were significantly (P &lt; 0·001) reduced by day 9. Differences between the two nutrition groups in maternal and umbilical plasma glucose concentrations at day 90 were not significant, though foetuses from 0·5 M and 1·5 M ewes removed a mean of 30 and 11% respectively of available glucose from the umbilical vein. Differences in live weight between 1·5 M and 0·5 M animals at weaning and in the post-weaning period were not significant (P &gt; 0·05). Wool production and woolquality were similar for both groups. Spontaneous ovulation rates measured on four occasions during the postpubertal oestrous season and on three occasions the following year were not significant (P &gt; 0·05). Treatment with pregnant mare's serum gonadotrophin (PMSG) increased ovulation rates in the ewes of both groups; however, the differences failed to reach significance (P &gt; 0·05); mean (± S.e.) ovulations per ewe were 4·8 ± 0·61 ν. 4·6 ± 0·60 for 1·5 M and 0·5 M group ewes respectively.