Preservation Of Blood Flow Research Articles

Patterns of Dynamic Adaptability of the Circle of Willis in Response to Major Branch Artery Coverage with a Flow Diverter

The plasticity of the Circle of Willis represents an underexplored yet intriguing dimension of vascular anatomy in cerebrovascular disorders. We outline distinct patterns of change in response to aneurysm treatment using flow diversion (FD) after covering major branches. Retrospective analysis of digital subtraction angiographies (DSA) from intracranial aneurysms treated with FD from 2013 to 2023. Vessel diameters, including those covered by the stent and adjacent arteries, were measured. Angiographic changes were evaluated at last imaging follow-up. Of the 622 patients, 49 had angiographic follow-up for pattern assessment. The median age was 62 years; females represented 71.4%. The median size of the treated aneurysms was 4.7mm. Four patterns of angiographic change were identified: (1)Patients with supraclinoid aneurysms, A1-ACA caliber increased (hypoplastic: 1.05 to 2.00 mm; non-hypoplastic: 2.45 to 2.75 mm) after FD coverage of the contralateral ACA. (2)Patients with paraclinoid aneurysms and hypoplastic-fetal P1-PCA, the diameter increased from 0.80 to 1.7 mm (p<0.01) after covering the ipsilateral PComA origin. (3)Patients with basilar-tip and proximal PCA aneurysms showed increased ipsilateral PComA size from 1.2 to 2 mm (p<0.01) after PCA origin coverage. (4)Patients with anterior communicating aneurysms, the diameter of the contralateral hypoplastic A1 segment increased from 1.0 to 1.35 mm (p=0.39) or non-hypoplastic A1-ACA from 2.75 to 3.05 mm (p=0.10) after FD coverage. The circle of Willis displays both hemodynamic and anatomic plasticity after major branch coverage with a flow diverter. This phenomenon is aimed at preserving blood flow in the distal territory of the covered vessel.

Sparsentan improves glomerular hemodynamics, cell functions, and tissue repair in a mouse model of FSGS.

Dual endothelin-1 (ET-1) and angiotensin II (AngII) receptor antagonism with sparsentan has strong antiproteinuric actions via multiple potential mechanisms that are more pronounced, or additive, compared with current standard of care using angiotensin receptor blockers (ARBs). Considering the many actions of ET-1 and AngII on multiple cell types, this study aimed to determine glomeruloprotective mechanisms of sparsentan compared to the ARB losartan by direct visualization of its effects in the intact kidney in focal segmental glomerulosclerosis (FSGS) using intravital multiphoton microscopy. In both healthy and FSGS models, sparsentan treatment increased afferent/efferent arteriole diameters; increased or preserved blood flow and single-nephron glomerular filtration rate; attenuated acute ET-1 and AngII-induced increases in podocyte calcium; reduced proteinuria; preserved podocyte number; increased both endothelial and renin lineage cells and clones in vasculature, glomeruli, and tubules; restored glomerular endothelial glycocalyx; and attenuated mitochondrial stress and immune cell homing. These effects were either not observed or of smaller magnitude with losartan. The pleiotropic nephroprotective effects of sparsentan included improved hemodynamics, podocyte and endothelial cell functions, and tissue repair. Compared with losartan, sparsentan was more effective in the sustained preservation of kidney structure and function, which underscores the importance of the ET-1 component in FSGS pathogenesis and therapy.

Initial Experience of the Covered Endovascular Reconstruction of Iliac Bifurcation Technique.

The distal landing zone in iliac arteries represents an important issue during endovascular repair of abdominal aortic aneurysms (EVAR). The aim of this study is to present a case series for landing in the external iliac artery (EIA) during EVAR while preserving blood flow in the internal iliac artery (IIA) with the covered endovascular reconstruction of the iliac bifurcation (CERIB) technique. This is a single-center, retrospective analysis of prospectively collected data of patients that underwent EVAR either for intact abdominal aortic aneurysm (AAA) or previous failed EVAR from December 2022 up to September 2023. Indications for treatment were presence of common iliac artery aneurysm (CIAA), short CIA, or endoleak type Ib (ETIb). For the distal sealing zone, we used balloon-expandable covered stent (BXCS). Primary outcomes were technical success and first-month patency rate. Secondary outcomes were endoleak and re-intervention rate. Sixteen patients being treated with 20 CERIBs were included in the study. Four patients had a previous failed EVAR, while 3 patients were treated urgently for a symptomatic para-renal aneurysm. The indications for treatment were EIb (n=2), short CIA (n=4), CIAA with narrow lumen (n=3), and CIA aneurysm (n=11). Platforms that were used were the Cook Zenith Alpha (n=5), Gore C3 (n=2 and 3 limbs), Endurant IIs (n=2, and 3 limbs), and a t-branch device (n=3). Technical success rate was 100% with no adjunctive procedure. No death or re-intervention was recorded for all patients at postoperative 30-day period and at 6 months for 2 patients. At first-month CTA, patency rate was 100% (20/20), while in 2 patients that had 6-month CTA, the patency was also 100% (2/2). No kinking or stenosis was also noted. Two patients had ETIII after branched EVAR (BEVAR), 2 patients had ETII, and 1 patient had gutter ET in the area of the CERIB. The CERIB technique seems to be effective and safe in the early period. It is suitable with a variety of commercial endograft platforms. It may be a valuable alternative to iliac branch devices when there are anatomical considerations. Longer follow-up is needed to conclude for long-term patency and durability. The distal landing zone in iliac arteries represents an important issue during EVAR while it is important to preserve blood flow in the internal iliac artery. The covered endovascular reconstruction of the iliac bifurcation (CERIB) technique is a technique for the preservation of internal iliac arteries during EVAR, while it is suitable with a variety of commercial endograft platforms. The CERIB technique seems to be effective and safe in the early period. It may be valuable alternative to iliac branch devices when there are anatomical considerations.

Improved flap perfusion and hemostasis after postoperative embolization in free flap surgery: a case report

This study aims to present a novel use of coil embolization in managing postoperative bleeding after free flap surgery, a technique typically reserved for other medical complications. We report the case of a 77-year-old female patient who underwent muscle-sparing latissimus dorsi free flap surgery for recurrent myxofibrosarcoma on her left thigh. Although hemostasis was achieved hemostasis during surgery, the patient experienced postoperative bleeding, which was initially managed with compression and blood transfusions. Upon a critical drop in the hemoglobin level, coil embolization was performed at the proximal segment of the descending branch of the lateral circumflex femoral artery. Coil embolization successfully controlled bleeding, while preserving blood flow to the flap. The patient’s hemoglobin levels stabilized, and the flap’s perfusion improved post-procedure. This approach proved effective in managing bleeding in areas other than the anastomosis site, with the patient showing a satisfactory recovery and no significant complications in the 30-day postoperative period. Coil embolization, a method commonly used for gastrointestinal bleeding and other vascular issues, can be a viable and effective option for controlling postoperative bleeding after free flap surgery. This case demonstrates its potential as a lifesaving intervention while preserving flap viability. However, further research with more cases is needed to evaluate the generalizability and long-term outcomes of this technique in similar surgical contexts.

TEVAR with fenestrations of all supra-aortic branches for traumatic aortic pseudoaneurysm: Case report and systematic review.

Blunt thoracic aortic injuries (BTAIs) involving the aortic arch are a challenging condition. Thoracic endovascular aortic repair (TEVAR) with fenestration, which expands the proximal landing zone, is able to exclude the injury while preserving blood flow in supra-aortic branches. Here we report a case of TEVAR with fenestrations of all supra-aortic branches for traumatic aortic pseudoaneurysm and perform a systematic review. A 24-year-old man suffering a blunt thoracic injury and a left femoral fracture was sent to our hospital. A pseudoaneurysm was found in the aortic arch between the brachiocephalic artery and the left common carotid artery. The patient underwent emergent TEVAR with fenestrations of all supra-aortic branches, which excluded the pseudoaneurysm and preserved the patency of all branches. The orthopedic team then treated the femoral fracture. The patient's recovery was unremarkable. We performed a systematic review on TEVAR with fenestrations for BTAI. Six patients (75%) received TEVAR with single fenestration, 1 patient (12.5%) received TEVAR with two fenestrations, and 1 patient (12.5%) had fenestrations of all supra-aortic branches. Except one patient died in the perioperative, other patients survived without stent-related complications in the short-term follow-up. TEVAR with fenestration is feasible for treating BTAI involving the aortic arch in selected patients.

Abstract 1159: Harnessing Limb Revascularization With Synthetic Probiotics

Peripheral arterial disease (PAD) is a critical vascular condition that results in impaired blood flow leading to chronic limb threatening ischemia (CLTI), tissue necrosis and oftentimes to lower-limb amputation. This is largely due to suboptimal revascularization and inflammatory programs, that fail to instigate neovascularization at sites of vessel stenosis. The incidence of CLTI is on the rise but yet there is a paucity of effective treatment options for patients. We hypothesized that the coordinated action of regenerative angiogenesis and immunosurveillance would likely stimulate effective revascularization in the ischemic leg. The neuroimmune cue, Netrin-1 has been shown to possess such properties. We have shown that Netrin-1 can assist atherosclerosis onset by modulating macrophage chemotaxis and shown its critical role in modulating vascular remodeling. Here we show that the conditional knock-down of Netrin-1 in myeloid cells (Ntn1 flox/flox LysM cre+ ), protects mice from revascularization following femoral artery ligation compared to WT littermates. The deletion of Netrin-1 in endothelial cells nor vascular smooth muscle cells was insufficient to produce such effects. Notably, in human amputated tissue sections, the expression of Netrin-1 was repressed at sites proximal to amputated sites compared to distal regions with preserved blood flow. Tissue macrophages were packed with Netrin-1 and it exerted its effects in an autocrine/paracrine manner via its receptor Unc5b. The use of synthetic biology to engineer bacteria with tailored functionalities presents a cutting-edge avenue for developing novel therapeutic tools. We therefore employed a synthetic biology approach to deliver exogenous Netrin-1 to the ischemic leg. The Nissle probiotic was genetically engineered to overexpress murine Netrin-1. The local administration of this probiotic to ischemic limb of Ntn1 flox/flox LysM cre+ mice was sufficient to recapitulate blood flow and reperfusion in the leg comparable to WT mice (and sham probiotic) in 2 weeks. Our results show the therapeutic potential of the use of synthetic microorganisms and Netrin-1 for innovative and adaptable solutions in limb regenerative medicine.

Investigation into safflower injection as a prophylactic treatment for retinal vein occlusion in a rabbit model

The study aimed to assess the effect and mechanism of safflower injection in preventing retinal vein thrombosis in rabbits. Twenty healthy adult pigmented rabbits were randomly assigned to either the experimental group, receiving safflower injection, or the control group, receiving normal saline. After two weeks of treatment, blood samples were collected to analyze platelet adhesion and aggregation rates. Photodynamic therapy was applied to induce occlusion in the target retinal vein. Fundus photography and fluorescein angiography were recorded using a dynamic microscopic monitoring system, and laser speckle imaging was employed to assess blood flow in the affected vein. The experimental group exhibited significantly lower rates of platelet adhesion and aggregation compared to the control group. Following the induction of retinal vein occlusion, the experimental group showed a lower complete occlusion rate of the target retinal vein. Although initial blood flow in the target vein was similar between groups, the blood flow at 1, 3, and 5 min post-occlusion was significantly higher in the experimental group. Safflower injection delayed retinal vein thrombosis formation, preserved blood flow in the affected retinal area, and reduced platelet adhesion and aggregation. These effects facilitated vascular reperfusion within a limited timeframe.

Hawkins Sign of the Talus: The Impact of Patient Factors on Prediction Accuracy

Introduction/Purpose: Avascular necrosis (AVN) is a complication of talar neck fractures associated with chronic pain and poor functional outcomes. Hawkins sign, the radiographic presence of subchondral lucency seen in the talar dome 6 to 8 weeks after trauma, is considered to be a strong predictor of preserved talus vascularity. The study sought to assess the accuracy of the Hawkins sign in a large, contemporary cohort and assess factors associated with inaccuracy. Methods: A retrospective review of all talar neck fractures from a single level I trauma center from 2008 to 2016 was performed. The presence of Hawkins sign and AVN were determined based on ankle radiographs 8 weeks after injury and at final follow-up, respectively. Patients with less than 6 months follow-up were excluded. Hawkins sign accuracy was assessed using proportions with 95% confidence intervals (C.I.) and associations were examined with Fisher’s exact testing. Results: In total, 137 talar neck fractures were identified with 105 having adequate follow-up. Hawkins sign was observed in 21 tali, 3 (14%) of which later developed AVN (95% C.I., 3 – 36%). In the remaining 84 tali without Hawkins sign, 32 (38%) developed AVN (95% C.I., 28 – 49%). Of the 3 tali that developed AVN following observation of Hawkins sign, all patients were smokers. There were no cases of AVN in non-smokers with Hawkins sign (P=0.21), and smoking was not associated with AVN in patients without Hawkins sign (41% vs 36%, P=0.82). Conclusion: Hawkins sign may not be a reliable predictor of preserved talus vascularity in all patients. We identified three patients with positive Hawkins signs who developed AVN, all of whom were smokers. Factors impairing microvascular blood supply to the talus may lead to AVN even in the presence of preserved macrovascular blood flow and an observed Hawkins sign. Close monitoring of select patients with Hawkins sign should be considered and further research is needed to understand the factors limiting Hawkins sign accuracy. Prognostic accuracy of the Hawkins sign in predicting talar AVN

The Hawkins Sign of the Talus: The Impact of Patient Factors on Prediction Accuracy.

Osteonecrosis is a complication of talar neck fractures associated with chronic pain and poor functional outcomes. The Hawkins sign, the radiographic presence of subchondral lucency seen in the talar dome 6 to 8 weeks after trauma, is a strong predictor of preserved talar vascularity. This study sought to assess the accuracy of the Hawkins sign in a contemporary cohort and assess factors associated with inaccuracy. A retrospective review of talar neck fractures at a level-I trauma center from 2008 to 2016 was conducted. Both the Hawkins sign and osteonecrosis were evaluated on radiographs. The Hawkins sign was determined on the basis of radiographs taken approximately 6 to 8 weeks after injury, whereas osteonecrosis was determined based on radiographs taken throughout follow-up. The Hawkins sign accuracy was assessed using proportions with 95% confidence intervals (CIs), and associations were examined with Fisher exact testing. In total, 105 talar neck fractures were identified. The Hawkins sign was observed in 21 tali, 3 (14% [95% CI, 3% to 36%]) of which later developed osteonecrosis. In the remaining 84 tali without a Hawkins sign, 32 (38% [95% CI, 28% to 49%]) developed osteonecrosis. Of the 3 tali that developed osteonecrosis following observation of the Hawkins sign, all were in patients who smoked. A positive Hawkins sign may not be a reliable predictor of preserved talar vascularity in all patients. We identified 3 patients with a positive Hawkins sign who developed osteonecrosis, all of whom were smokers. Factors impairing the restoration of microvascular blood supply to the talus may lead to osteonecrosis despite the presence of preserved macrovascular blood flow and an observed Hawkins sign. Further research is needed to understand the factors limiting Hawkins sign accuracy. Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

＜Editors' Choice＞ Thoracic endovascular aortic repair and spinal cord injury.

We previously reported that spinal cord injury following thoracic endovascular aortic repair for a thoracic aortic aneurysm is a micro embolism caused by a vulnerable mural thrombus. Conversely, patients who underwent thoracic endovascular aortic repair for aortic dissection develop spinal cord injury less frequently due to fewer mural thrombi. Paying attention to preserving blood flow toward the spinal cord, namely collateral circulation and steal phenomenon, prevents spinal cord injury following thoracic endovascular aortic repair for aortic dissection.

Long-term Outcome of Laparoscopic Surgery for Nonpalpable Undescended Testis.

The aim of this study was to objectively assess the long-term results of laparoscopic orchidopexy in patients who were diagnosed clinically to have nonpalpable undescended testis (UDT). All operated cases of nonpalpable UDT from January, 2000, to January, 2014, were reviewed. After informed consent, all patients were subjected to a color Doppler ultrasound examination to assess the location of the testis, its size, blood supply, and consistency. The size of the testis, operated and nonoperated, was noted down in volume using the formula of 0.71 × length × breath × height. A total of 114 patients could be identified, who had undergone laparoscopy for nonpalpable UDT in the study period. Of these, 44 patients (54 units) underwent a color Doppler study to assess the testes. All the testes were found to lie in the scrotum with preserved blood supply. The volume of the operated unilateral testes (mean = 1.605 cm3) was smaller than the normal nonoperated side (mean = 2.524 cm3). The smaller testicular volume was observed in spite of maintained blood supply to the testes. In cases of bilateral UDT, both the testes were smaller in size (mean = 2.2 cm3), but were comparable to each other. In addition, the ultrasound examination revealed the presence of normal homogenous parenchyma of all the testes similar to the nonoperated side. Laparoscopic orchidopexy is a safe and effective option in the treatment of nonpalpable UDT. On a long-term basis, it is possible to achieve scrotal position along with preserved blood flow following laparoscopic orchidopexy in all patients suffering from nonpalpable UDT.

Endovascular Treatment for Intracranial Artery Dissections in Posterior Circulation.

Intracranial artery dissections (IADs), although uncommon, are an important cause of cerebral infarction and subarachnoid hemorrhage (SAH). Some IADs can heal spontaneously after reconstitution of the vessel lumen with excellent prognosis. Meanwhile, others can progress to stroke that requires treatment. The incidence of IAD in the posterior circulation is higher than that in the anterior circulation. Anterior circulation dissections are more likely to develop into ischemia and posterior circulation lesions into hemorrhage. The mortality rate after IAD among patients with SAH is 19%-83%. Further, the mortality rate of IAD without SAH is 0%-3%. Patients with SAH commonly undergo surgery or receive neuroendovascular treatment (EVT) to prevent rebleeding. However, the treatment of IADs is empirical in the absence of data from randomized controlled trials. Recently, EVT has emerged and is considered for IADs because of its less invasiveness and perceived low rates of procedure-related morbidity with good efficacy. EVT strategies can be classified into deconstructive (involving sacrifice of the parent artery) and reconstructive (preserving blood flow via the parent vessel) techniques. In particular, the number of reports on reconstructive techniques is increasing. However, a reconstructive technique for ruptured IADs has not yet been established. This review aimed to provide an overview of IADs in the posterior circulation managed with EVT by performing a literature search.

Diagnosis of testicular torsion with preserved blood flow detected by color Doppler ultrasonography

BackgroundTo diagnose testicular torsion promptly and accurately when diagnosis of testicular torsion is difficult by color Doppler ultrasonography owing to testicular blood flow, we assess the helpfulness of physical findings to aid diagnosis of testicular torsion in cases with preserved testicular blood flow.MethodsWe retrospectively collected data of 45 patients below 18 years of age with suspected diagnosis of testicular torsion and underwent surgery. The clinical data of testicular torsion with normal testicular blood flow were compared to testicular torsion with normal testicular blood flow or no-testicular torsion for accurate diagnosis of testicular torsion.ResultsTesticular torsion was diagnosed in 34 of the 45 patients, and normal testicular blood flow was detected in six of the 34 patients. In testicular torsion with normal flow, duration of symptoms was significantly shorter, and the degree of torsion was significantly more mild than decreased blood flow. All testicular torsion with normal testicular flow had abnormal testicular findings. Duration of symptoms in patients with testicular torsion with normal flow was also significantly shorter than non-testicular torsion.ConclusionsIf testicular blood flow is detected, the presence of abnormal testicular findings and short duration of symptom are highly suspicious for testicular torsion.

Distal radial artery access for the treatment of complications after ulnar artery catheterization

Objective: to study the effectiveness of the distal radial artery access in the treatment of complications after ulnar artery catheterization. Material and methods. We analyze the outcomes of 1558 catheterizations of the ulnar arteries. Less than 1% of local hemorrhagic complications and 1.5% of post-catheterization occlusions of the ulnar artery were revealed after ulnar artery catheterization, Results. One half of the patients with hemorrhagic complications after ulnar artery catheterization underwent conservative treatment (mechanical compression of the site of complication), the rest of patients underwent surgical treatment. Positive effect was achieved in all patients who underwent endovascular treatment for post-catheterization hemorrhagic complications. In 50% of cases, recanalization of post-catheterization ulnar artery occlusion via the distal radial access was effective. In 1 patient after recanalization of post-catheterization ulnar artery occlusion using the distal radial artery access, the occlusion of radial artery in wrist segment occurred, with preserved blood flow in radial artery of the forearm. Conclusion. Distal radial artery access for correction of post-catheterization complications in ulnar artery is a feasible and safe method. Keywords: distal radial access, ulnar artery, radial artery, occlusion

The Effect of Circle of Willis Morphology on Retinal Blood Flow in Patients with Carotid Stenosis Measured by Optical Coherence Tomography Angiography.

The Circle of Willis (CoW) is the main collateral system, and its morphological variants are more common in patients who have severe carotid artery stenosis. Earlier data suggest that optical coherence tomography angiography (OCTA) may help to assess the changes in cerebral vascular perfusion by imaging the retinal blood flow. In this single-center prospective clinical study, patients scheduled for carotid endarterectomy (CEA) underwent preoperative computed tomography angiography (CTA) of the extra- and intracranial cerebral circulation. OCTA imaging was performed one week before surgery and postoperatively one month later. The patients were divided into two subgroups based on CTA evaluation of CoW: compromised CoW or non-compromised CoW (containing hypoplastic and normal segments). The effect of the patient's age, OCTA scan quality (SQ), CoW morphology, laterality, and surgery on superficial capillary vessel density (VD) in the macula were assessed in multivariable regression models using linear mixed models. We found that VD significantly decreased with aging (-0.12%; 95%CI: -0.07--0.15; p < 0.001) and was significantly higher in patients with non-compromised CoW morphology (by 0.87% 95%CI (0.26-1.50); p = 0.005). After CEA, retinal blood flow significantly improved by 0.71% (95%CI: 0.18-1.25; p = 0.01). These results suggest that in the case of carotid artery occlusion, patients with non-compromised CoW have more preserved ocular blood flow than subjects with compromised CoW due to remodeling of the intra-orbital blood flow. Measuring the retinal blood flow might be used as a relevant and sensitive indicator of collateral cerebrovascular circulation.

R-(+)-WIN55212-2 protects pericytes from ischemic damage and restores retinal microcirculatory patency after ischemia/reperfusion injury

Background and purposeCannabinoids are vasoactive substances that act as key regulators of arterial tone in the blood vessels supplying peripheral tissues and the central nervous system. This study aimed to investigate the potential of R-(+)-WIN55212-2 (WIN), a cannabinoid receptor 1 agonist (CB1), as a treatment for retinal ischemia/reperfusion (I/R) injury. Experimental approachMale Wistar rats were subjected to retinal I/R injury by increasing intraocular pressure in the anterior chamber. The rats were randomly divided into four groups: normal control, I/R, vehicle (pre-treated with dimethyl sulfoxide [DMSO] via intraperitoneal injection), and experimental (pre-treated with WIN at a dose of 1 ml/kg via intraperitoneal injection). The rats were sacrificed at different time points of reperfusion (1 hour, 3 hours, 6 hours, and 1 day) after inducing retinal I/R injury, and their retinas were collected for analysis. Oxygen-glucose deprived/reperfusion (OGD/R) was performed by initially perfusing the retinas with oxygenated artificial cerebrospinal fluid (ACSF), then switching to an OGD solution to simulate ischemia, followed by another perfusion with ACSF. Pericyte contraction and the "no-reflow" phenomenon were observed using infrared differential interference contrast (IR-DIC) microscopy and immunohistochemistry. Western blot, enzyme-linked immunosorbent assay (ELISA), and nitric oxide (NO) detection were used to explore the potential mechanism. Key resultsIn both the OGD/R and I/R models, retinal pericytes exhibited persistent contraction even after reperfusion. The ability of WIN to regulate the tone of retinal pericytes and capillaries was specifically blocked by the BKCa inhibitor iberiotoxin (100 nM). WIN demonstrated a protective effect against retinal I/R injury by preserving blood flow in vessels containing pericytes. Pretreatment with WIN alleviated the persistent contraction and apoptosis of retinal pericytes in I/R-induced rats, accompanied by a reduction in intracellular calcium ion (Ca2+) concentration. The expression of CB1 decreased in a time-dependent manner in the I/R group. After I/R injury, endothelium-derived nitric oxide (eNOS) levels were reduced at all time points, which was successfully reversed by WIN therapy except for the 1 day group. Additionally, the downregulation of cyclic guanosine monophosphate (cGMP) and BKCa expression at 3 hours, 6 hours, and 1 day after I/R injury was restored by pretreatment of WIN. Conclusions & implicationsWIN exerted its protective effects on retinal I/R injury by inhibiting the contraction and apoptosis of pericytes through the CB1-eNOS-cGMP-BKCa signaling pathway, thus ameliorated the occlusion of retinal capillaries.

Testicular Torsion in Children. Diagnostic and Prognostic Potential of Ultrasonography

Introduction: Testicular torsion is the most urgent case in pediatric andrology that requires emergency care due to the high sensitivity of testicular tissue to hypoxia.Objective: To determine statistically significant parameters indicating diagnostic significance of some ultrasonographic testicular torsion symptoms in children.Materials and methods: Ultrasonography was performed in 202 children with testicular torsion (main group) and 449 patients (control group) aged from 2 months to 17 years 11 months and 28 days. During statistical processing we determined the mean values, their standard deviation, sampling errors, significance of differences in the mean values, correlation coefficient and did ROC analysis. For an objective ultrasonographic assessment of testicular shape, we implemented the coefficient of rounding – ko = (testicular length – testicular thickness) / testicular length – and the parameter Δko calculated as the difference between ko for the affected side and the contralateral one.Results and discussion: Testicular torsion was more common in children above 12 years of age (84.7%). The ko was 0.160 ± 0.007 in the group of children with testicular torsion and 0.037±0.003 in the control group (t = 16.92, p &gt;&gt; .001). The ROC analysis proved the Δko to be highly informative: AUC was 0.886. The Δko was 0.130 ± 0.008 for patients with favorable treatment outcomes and 0.19 ± 0.01 (p &lt; 0.001) for those with unfavorable outcomes. In most cases (71), the whirlpool sign was visualized with preserved blood flow. In such a case, the probability of the favorable treatment outcome was 74.6%. The whirlpool sign visualization was significantly less common (31 cases) without Doppler ultrasonography; favorable treatment outcomes were achieved in 54.8%. Of 22 patients with the undetected whirlpool sign, favorable treatment outcomes were possible only in 40.9%.Conclusions: The coefficient of rounding ko can be used as an auxiliary criterion for the early diagnosis of testicular torsion. With Δko = 0.08, the sensitivity of the parameter in respect of testicular torsion is 79.2%, and specificity is 85.7%. With Δko = 0.16, the specificity of the parameter is almost 100% with a 45.0% decrease of the sensitivity. Whirlpool sign detection using color Doppler ultrasonography is a positive prognostic factor.

Increased cerebral vascular resistance underlies preserved cerebral blood flow in response to orthostasis in humans on a high-salt diet.

Cerebral blood flow autoregulation protects brain tissue from blood pressure variations and maintains cerebral perfusion pressure by changes in vascular resistance. High salt (HS) diet impairs endothelium-dependent vasodilation in many vascular beds, including cerebral microcirculation, and may affect vascular resistance. The aim of present study was to determine if 7-day HS diet affected the reactivity of middle cerebral artery (MCA) to orthostatic challenge in healthy human individuals, and if autoregulatory mechanisms and sympathetic neural regulation were involved in this phenomenon.Twenty-seven persons participated in study (F:21, M:6, age range 19-24). Participants consumed 7-day low-salt (LS) diet (< 2.3g kitchen salt/day) and afterwards 7-day HS diet (> 11.2g kitchen salt/day). Blood and urine analysis and anthropometric measurements were performed after each diet. Arterial blood pressure, heart rate and heart rate variability, and cerebral and systemic hemodynamic parameters were recorded simultaneously with transcranial Doppler ultrasound and The Task Force®Monitor in response to orthostatic test.Participants remained normotensive during HS diet. Following both, the LS and HS dietary protocols, mean cerebral blood flow (CBF), as well as the velocity time integral and diastolic blood pressure decreased, and cerebral pulsatility index increased after rising up. Importantly, cerebrovascular resistance significantly increased in response to orthostasis only after HS diet. Urine concentration of noradrenaline and vanillylmandelic acid, baroreflex sensitivity (BRS), and sympathetic neural control was significantly decreased in HS diet.Results suggest that CBF in response to orthostatic test was preserved in HS condition due to altered vascular reactivity of MCA, with increased cerebrovascular resistance and blunted BRS and sympathetic activity.

Clinical risk factors for testicular torsion and a warning against falsely reassuring ultrasound scans: a 10-year single-centre experience

BackgroundWe sought to determine which demographic, clinical and ultrasonography characteristics are predictive of testicular torsion (TT) and to determine factors associated with time to treatment.MethodsWe retrospectively reviewed all medical records...

Treatment for Subdural Hematoma in Infants

This chapter will discuss the treatment for infant subdural hematoma. In adult cases, treatment focused on intracranial pressure(ICP)management alone is generally sufficient, but in infant cases, special ingenuity is required. First, there are some points to keep in mind regarding surgical procedures. It is important to perform blood transfusion from an early stage, avoid exposure of bleeding points, and reduce ICP by floating the bone flap that preserves blood flow. Next, it is necessary to understand the pathophysiology peculiar to infants. Extensive lower density changes seen on head computed tomography can have a profound effect on clinical outcome. This phenomenon should not be considered as simple cerebral ischemia, but is representative of the brain damage caused by status epilepticus and hyper perfusion injury. Therefore, not only ICP management, but also treatment for status epilepticus is extremely important for postoperative management. Further, cases where abuse is the cause of subdural hematoma often display poor outcomes due to a variety of medico social factors.