Low-flow Type Research Articles

Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency, a Rare Cause of Ischemic (Low Flow) Type of Penile Priapism: Case Report and Literature Review

Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency, a Rare Cause of Ischemic (Low Flow) Type of Penile Priapism: Case Report and Literature Review

Early Experience with Ovation Alto Stent-Graft

Alto is the latest generation of the Ovation stent-graft platform for endovascular aneurysm repair (EVAR). Its ultra-low profile and its proximal sealing zone close to the lowest renal artery (≥7mm) increase standard EVAR eligibility. We report early clinical and technical outcomes with the Alto stent-graft in our University Hospital Center after CE Mark approval in August2020. Seven patients (all male, mean age 76.1±6.2years) underwent EVAR with Ovation Alto stent-graft between June 2021 and February 2022. All the EVAR procedures were performed by a team of vascular surgeons experienced on EVAR with previous generation of Ovation platform. Follow-up consisted of duplex ultrasound examination at 1, 3, and 6months and of a 1-month control computed tomography angiography (CTA). Patients treated gave consent to participate in this case series and publication. A descriptive analysis of variables was performed. SPSS (version 25) and Excel were used for statistical analysis. Most of the patients had a fusiform abdominal aortic aneurysm (n=5; 71.4%). The median maximal transversal aortic diameter was 5.06cm (range, 3.98-6.99). Because of hostile aortic neck anatomy, on-label EVAR was considered feasible only with Ovation Alto stent-graft. Narrow iliac arteries (<6mm) were also present in 2 cases. All procedures were performed according to the instruction for the use of the device. Technical success was achieved in all cases. No type IA/IB/III endoleak occurred at completion angiography. No distal migration (>10mm) but 2 distal displacements (≥2mm) were observed at control CTA. During follow-up, duplex ultrasound and CTA showed no type I/III endoleak, no stent-graft migration (>10mm), and no proximal aortic neck variations (P=not statistically significant). Three patients (42.8%) are under strict surveillance because of low-flow type II endoleak not associated with sac variations. Our early experience shows promising technical and clinical success with Alto stent-graft. The proximal relocation of the proximal sealing rings and the ultra-low profile delivery system allow on-label EVAR in a wider range of aortic anatomies. Notwithstanding, further studies, meta-analysis, and prospective registries are mandatory to evaluate mid- and long-term efficacy and safety of this latest Ovation platform.

Remodeling of abdominal aortic aneurysm sac following endovascular aortic repair: association with clinical, surgical, and genetic factors

After successful endovascular aortic repair (EVAR), abdominal aortic aneurysms (AAA) sac will undergo negative remodeling (i.e., shrinkage) as a measure of successful exclusion. Determinants of shrinkage after EVAR are not fully known.In 84 post-EVAR patients, time course of AAA diameter after repair and occurrence of endoleaks (ELs) have been correlated with clinical history, medications, anthropometric data, vascular anatomy, and matrix metalloprotease (MMP) genetic variants (namely MMP-1 rs1799750, MMP-3 rs35068180, MMP-9 rs2234681, rs917576, rs917577, MMP-12 rs652438, and TIMP1 rs4898).During follow-up, 41 ELs were detected in 37 patients (44%, 10.4 events/100 pt./y), accounting for AAA dilation or reduced shrinkage (P < .001). High-flow ELs (type 1 and/or 3) occurrence was associated with warfarin use, MMP9 rs17577 polymorphism, and unfavorable anatomy, while low-flow type 2 ELs occurred more often in TIMP1 rs4898 non-T carriers. In EL-free patients, AAA diameter decreased for the first three years, (-4, -3 and - 2 mm/year respectively) and remained stable thereafter. Shrinkage between two measurements (n = 120) was associated with smaller AAA diameter at the baseline, peripheral arterial disease (PAD), patients’ older age at intervention, and G-/G- genotype in MMP1 rs1799750 (binary logistic regression, P = .0001).Aneurysmal sac shrinking occurs for few years after EVAR, only in patients without EL, and is related to older age, PAD, smaller aneurysm size and putative lower MMP1 expression while EL occurrence prevents such a remodeling and is mainly related to local-acting factors like unfavorable anatomy, anticoagulation, and MMP9 and TIMP1 genetic polymorphisms.

The Problem of Accounting for Heat Exchange between the Flow and the Flow Part Surfaces When Modeling a Viscous Flow in Low-Flow Stages of a Centrifugal Compressor

In this paper, we review the problem of accounting for heat exchange between the flow and the flow part surfaces when creating a calculation model for modeling the workflow process of low-flow stages of a centrifugal compressor using computational fluid dynamics (CFD). The objective selected for this study was a low-flow intermediate type stage with the conditional flow coefficient Փ = 0.008 and the relative width at the impeller exit b2/D2 = 0.0133. We show that, in the case of modeling with widespread adiabatic wall simplification, the calculated temperature in the gaps between the impeller and the stator elements is significantly overestimated. Modeling of the working process in the flow part was carried out with a coupled heat exchanger, as well as with simplified accounting for heat transfer by setting the temperatures of the walls. The gas-dynamic characteristics of the stage were compared with the experimental data, the heat transfer influence on the disks friction coefficient was estimated, and the temperature distributions in the gaps between disks and in the flow part of the stage were analyzed. It is shown that the main principle when modeling the flow in low-flow stage is to ensure correct temperature distribution in the gaps.

Neuro-Endovascular Intervention in Traumatic Carotico-Cavernous Fistulae: A Single-Center Experience.

IntroductionThe aim of this research was to describe a single-center practical experience in the management of traumatic carotid cavernous fistula (CCF).MethodsThere were a total of 31 patients between January 2005 and December 2019 with post-traumatic carotid cavernous sinus fistula (tCCF) who underwent treatment. We classified them into 2 types according to the flow of the CCF: patients with high flow CCF and patients with low flow CCF.ResultsAngiography revealed the high flow types on 21 patients (67.7%), the mean of patients ages are 31.5 years. Onyx embolization was performed in 1 patient (4.76%), transarterial balloon embolization was carried out in 10 patients (47.61%), transarterial coiling in 3 (14.28%) patients while 5 (28.8%) patients underwent transvenous routes to insert the coil and 2 patients (9.52%) were treated conservatively. Complete occlusion was achieved on all patients with coiling whereas the other treatment experiences the reducing flow of the fistula. We obtained 10 patients (32.2%) with a mean of 40.3 years as low flow type CCF. The patients with the low flow type mostly treated conservatively, because their symptoms were acceptable and intermittent.ConclusionThe ballooning currently became the more affordable treatment in our center. Balloon embolization was recommended for medium- and large-size fistula. The coils should be recommended for small-size fistula. In some cases occlusion of the fistula cannot be obtained using the detachable balloon, a coil can be used to occlude the cavernous sinus via trans arterial or trans venous access. If the fistula failed to be treated in traditional ways using balloons or coils, occlusion of the parent vessels could be another option.

Venolymphatic malformation of vastus medialis—case report

Background: Venolymphatic malformations (VLMs) are combination of venous and lymphatic components of low flow type of category. These malformations do not connect to the main channels directly. These present in the form of swelling and other characteristics as per the type of malformation. The diagnostic evaluation becomes more baffling if the overlying skin is normal. Case Presentation: We present a 55-year-old female who had swelling on the medial part of left knee which was causing some pain only during movements. The evaluation of the entity was done by ultrasound, color flow imaging (CFI), and magnetic resonance imaging (MRI). The diagnosis of VLM of vastus medialis was confirmed. Conclusion: VLM swellings of extremities can be diagnosed with confidence with CFI and MRI diagnostic modalities.

A Complex Case of Synchronous Thoracic and Abdominal Endoleak Repair with Custom-Made Relay NBS Thoracic Stent Graft and Abdominal Open Reconstruction

A 71-year old man with previous thoracic aneurysm endovascular repair and endovascular abdominal aneurysm repair presented with simultaneous type III endoleak from the thoracic components and type Ia endoleak from migration of the abdominal endograft, leading to enlargement of both aneurysms. A custom-made reverse tapered Relay NBS thoracic endograft was used to bridge the thoracic stent grafts. While a low-flow type III endoleak persisted in the immediate postoperative phase, because of incomplete apposition of the new stent graft, further deployment of its nitinol skeleton resulted in resolution of the endoleak at 1-week follow-up. The abdominal aneurysm enlargement was corrected via excision of the central segment of the abdominal endograft, preservation of the distal main body and limbs, and interposition of a short Dacron tube graft.

Endotensión. Revisión de un término controvertido

The current use of the term “endotension” in the treatment of aortic aneurysm is controversial. It was initially proposed to define the circumstance in which there is a growth of the aneurysm sac after endovascular repair without a demonstrable endoleak. The term was established with the aim of transmitting the possibility of causes other than pressure applying stress to the aneurysm wall. A review of the literature was performed with the aim of presenting an update on the advances of knowledge of the possible aetiological mechanisms. The experimental studies call into question that causes other than pressure determine the increase in the aneurysm. It is proposed that the term ‘aneurysm growth without identified endoleaḱ is more precise, and adjusted to what it is aimed to define. Evidence suggests that the more likely mechanisms of persistent pressurisation of the aneurysm sac are an unidentified endoleak (likely type I or low-flow Type II), or thrombus occluding wide and short channels that connect with the excluded aneurysm sac (at the attachment sites of the stent-graft or at the branch vessel orifices).

Aortic aneurysm endovascular treatment with the parallel graft technique from the aortic arch to the iliac axis.

The chimney technique has been developed for the treatment of complex aortic aneurysms. We analyzed the midterm to long-term outcomes of this approach from a single-center experience. From October 2008 to July 2016, 58 patients underwent endovascular aortic aneurysm repair using the chimney technique. Indications for treatment were thoracic aortic aneurysm (TAA) (N.=11), thoracoabdominal aortic aneurysm (TAAA) (N.=2), pararenal aortic aneurysm (PAAA) (N.=15), aortoiliac/isolated hypogastric artery aneurysm (N.=25), type I endoleak after previous TEVAR/EVAR (N.=4), proximal pseudoaneurysm after AAA open repair (N.=1). Elective (82.8%) and emergent (17.2%) procedures were included. The immediate technical success was 100%. Single, double and triple chimneys were performed in 46, 10, and two patients, respectively. Overall, 61 target vessels (three left common carotid arteries, eight left subclavian arteries, three celiac trunks, three superior mesenteric arteries, 19 renal arteries and 25 hypogastric arteries) were involved. Postoperative mortality was 0. No neurologic complications were registered. Primary patency rate of the chimney stent/stent graft was 98.3%. Low-flow type I endoleak was observed in four patients (6.9%). Postoperative chimney graft re-intervention rate was 1.7%. The median follow-up was 32±20 months (range 3-96 months). Overall estimated survival at 12, 50, and 80 months was 100%, 89% and 44%, respectively. Estimated freedom from endoleak at 1, 12, 24, and 36 months was 96.5%, 95%, 95%, and 93%, respectively. One hypogastric artery stent-graft occluded at the 3rd month of follow-up. No reintervention was performed. Our experience with the chimney technique for aortic aneurysms from the aortic arch to the iliac axis shows promising and durable mid- and long-term results. Endograft oversizing, associated with the chimney graft diameter and length choice remain fundamental to reduce the risk of the most frequent procedure complications: type I endoleak and CG occlusion. The wider use of this technique should be justified in patients considered at high risk for open repair and/or not suitable for the custom-made branched/fenestrated endografts.

Endograft repair for pseudoaneurysms and penetrating ulcers of the ascending aorta

ObjectiveThe aim of this paper is to report midterm results of thoracic endovascular aortic repair (TEVAR) for ascending aortic pseudoaneurysms (AAPs) and penetrating aortic ulcers (PAUs) of the ascending aorta. MethodsThis study was retrospective and performed at tertiary centers. Eight patients with AAPs (n = 5) and PAUs (n = 3) received total endovascular repair of the ascending aorta. Patients with a history of type A aortic dissection or fusiform aneurysm were excluded. All patients analyzed were considered to be at high risk for open repair at the time of presentation. ResultsUrgent intervention was performed in 6 (75%) cases. Primary clinical success was achieved in 7 (87.5%) cases. A low-flow type 3 endoleak remained asymptomatic and was managed conservatively. No TEVAR-related in-hospital mortality, primary conversion, cerebrovascular accidents, valve impairment, or myocardial infarction occurred. All patients were discharged home, alive and independent, after a median length of stay of 6 (range: 5-24) days. No patient was lost at a mean follow-up of 40 ± 33 (range: 4-93) months. Ongoing primary clinical success was maintained in all but 1 patient (type 3 endoleak): aortically related reintervention was never required. No endograft breakage or migration was observed. At 1-year follow-up, 7 (87.5%) aortic lesions had significant reduction in diameter (≥5 mm). ConclusionsAscending TEVAR was feasible, safe, and effective for AAPs and PAUs. In a very select subset of lesions, midterm results were favorable, with both standard and custom-designed endografts.

Diagnosis and management of priapism

Priapism is defined as an erection for more than 4 h without sexual stimulation. The most common form with nearly 95% is the ischemic or low-flow form, which is very painful. The other 5% are comprised of nonischemic high-flow type usually caused by a blunt perineal trauma and the recurrent or intermittent so-called stuttering priapism. Anamnesis as well as physical and laboratory examination are important during the diagnostic workup. Patients who suffer from sickle cell anemia are predestined to develop priapism. Priapism constitutes a urological emergency because especially the low-flow type has to be treated immediately to prevent a long-lasting fibrosis of the corpus cavernosa and a consecutive erectile dysfunction. The first step is the puncture and aspiration of blood from the corpus cavernosa if necessary combined with the injection of α-agonists. In case detumescence is not achieved, an operative shunt should be placed after an MRI. If there is a complete fibrosis of the corpus cavernosa possibly combined with penis deviation the implantation of a penile prosthesis is an option. The therapy of high-flow priapism is not as urgent as that of low-flow priapism because there is no risk of ischemia. If conservative therapeutic options fail, the superselective embolization of the fistula is the treatment of choice. In recurrent or intermittent priapism, the goal is to avoid new episodes with drug treatment. Because of the low incidence of priapism, it is very difficult to recommend and favor one therapeutic procedure.

Outcomes of patients with mild to moderate ischemic mitral regurgitation after coronary artery bypass graft surgery alone.

The chimney technique has been developed for the treatment of complex aortic aneurysms. We analyzed the midterm to long-term outcomes of this approach from a single-center experience. From October 2008 to July 2016, 58 patients underwent endovascular aortic aneurysm repair using the chimney technique. Indications for treatment were thoracic aortic aneurysm (TAA) (N.=11), thoracoabdominal aortic aneurysm (TAAA) (N.=2), pararenal aortic aneurysm (PAAA) (N.=15), aortoiliac/isolated hypogastric artery aneurysm (N.=25), type I endoleak after previous TEVAR/EVAR (N.=4), proximal pseudoaneurysm after AAA open repair (N.=1). Elective (82.8%) and emergent (17.2%) procedures were included. The immediate technical success was 100%. Single, double and triple chimneys were performed in 46, 10, and two patients, respectively. Overall, 61 target vessels (three left common carotid arteries, eight left subclavian arteries, three celiac trunks, three superior mesenteric arteries, 19 renal arteries and 25 hypogastric arteries) were involved. Postoperative mortality was 0. No neurologic complications were registered. Primary patency rate of the chimney stent/stent graft was 98.3%. Low-flow type I endoleak was observed in four patients (6.9%). Postoperative chimney graft re-intervention rate was 1.7%. The median follow-up was 32±20 months (range 3-96 months). Overall estimated survival at 12, 50, and 80 months was 100%, 89% and 44%, respectively. Estimated freedom from endoleak at 1, 12, 24, and 36 months was 96.5%, 95%, 95%, and 93%, respectively. One hypogastric artery stent-graft occluded at the 3rd month of follow-up. No reintervention was performed. Our experience with the chimney technique for aortic aneurysms from the aortic arch to the iliac axis shows promising and durable mid- and long-term results. Endograft oversizing, associated with the chimney graft diameter and length choice remain fundamental to reduce the risk of the most frequent procedure complications: type I endoleak and CG occlusion. The wider use of this technique should be justified in patients considered at high risk for open repair and/or not suitable for the custom-made branched/fenestrated endografts.

Indirect carotid-cavernous fistula of low-flow type: Color Doppler Imaging of retrobulbar vessels findings

Background. Carotid-cavernous fistulas (CCF) of low-flow type are the results of development of communication between small arteries and veins of cavernous sinus. Aim. To assess the role of CDI of retrobulbar vessels in the study of two patients with CCF of low-flow type. Methods. We have used a sonographer with 9MHz linear probe. Results. The initial diagnosis was suspected clinically: both patients presented unilateral chemosis and orbital bruit. It was sustained by CDI of retrobulbar vessels: reversed flow in the superior ophthalmic vein, with a venous arterialisation and confirmed with complete selective digital subtraction angiography, which is essential for a correct diagnosis( early opacification of veins draining cavernous sinus, etc). Conclusions. CDI of retrobulbar vessels is a repetitive non-invasive technique, which is used for monitoring carotid-cavernous fistulas of low-flow type, because they are sometimes a self-limiting pathology (spontaneous venous thrombosis).

Stuttering priapism complicating Warfarin therapy in a patient with protein C deficiency

Priapism is a rare disorder defined as a persistent penile erection that continues hours beyond, or is unrelated to, sexual stimulation. There are two types of priapism; ischemic low-flow type or non-ischemic high flow, with differing etiologies. Priapism associated with thrombophilia is a well-recognized entity. However, the pathogenesis of this association is not fully understood. We report a rare case of recurrent (stuttering) priapism in a patient with protein C deficiency while maintained on Warfarin therapy. This therapy was also complicated by Warfarin-induced skin necrosis.

Diagnosis and treatment of priapism: experience with 5 cases

Objectives. Priapism is a rare disease, but needs early intervention and appropriate management. We present 5 cases, 2 of nonischemic high-flow priapism and 3 of ischemic low-flow priapism.Methods. Focusing on the differential diagnosis of priapism between the nonischemic high-flow type and the ischemic low-flow type, we reviewed the medical records of 5 patients.Results. Of the examinations carried out, cavernosography, blood gas analysis of cavernosal blood, color Doppler ultrasound, and internal pudendal arteriography were useful in differentiating the type of priapism. Complete detumescence of the penis in 2 cases of high-flow priapism and 3 cases of low-flow priapism was achieved by selective embolization with gelform and by glandular-cavernosal shunting, respectively. No recurrence was observed in any patient, and postoperative erectile function was preserved in 4 patients and is unknown in 1.Conclusions. These results indicate that angiographic studies provide the most reliable information for the differentiation of the type of priapism. However, color flow Doppler ultrasound and cavernosal blood gas determination can obviate the need for angiographic studies and are noninvasive. Although conservative treatment or even expectant management may be feasible with high-flow priapism, aggressive treatment should be carried out for low-flow priapism immediately after initial treatment fails to achieve detumescence of the penis. Selective embolization of the internal pudendal artery may be the treatment of choice for patients with high-flow priapism.

オレイン酸モノエタノールアミンによる局所注入硬化療法を行った上唇血管腫の１例

Hemangiomas and vascular malformations often occur in the oral facial region. They can be classified as low-flow type or high-flow type, which have very different characteristics and prognoses. Both types must be carefully managed.We describe a lesion arising in the upper lip and measuring 25×20mm. Pretherapeutic angiography demonstrated low blood flow from the facial arteries through the tumor. Sclerotherapy was therefore performed. We used 10% ethanolamine oleate (EO) as the sclerosing agent, which is used for the endoscopic treatment of esophageal varices. After the injection of 10% EO, the lesion shrank and a good aesthetic outcome was obtained. There were no problematic side effects.When indicated, sclerotherapy with 10% EO is a simple and safe technique, provided it is performed correctly, sclerotherapy was considered very useful for lesions in which surgical treatment would result in considerable functional and aesthetic disfigurement.

Geochemistry of Rajapur and Puttur Thermal Springs of the West Coast, India

Abstract Thennal springs of Rajapur and Puttur (Irde and Banduru) are of low-temperature and low-flow type. Though they are located at two different geological set up, they fall in Na-HCO3 facies . The imprints of basalt - thermal water interaction at Rajapur and local equilibration of doleritic dyke with the thermal water of Irde is deduced. The reservoir of the Rajapur thermal spring is likely to be located in the Precambrian formations, as that of Puttur thermal springs and hence the chemical processes undergoing in these systems are similar. The reservoir temperatures estimated using chemical geothermometers are about 200°C and &amp;gt;120°C for the Puttur and Rajapur thermal springs respectively. Illite, K-mica. chlorite. kaolinite. Ca-montmorillonite and philipsite are the expected secondary minerals in the system.

PRIAPISM

Priapism in adult patients with sickle cell disease is a devastating complication for which there is no consensus regarding management. Innumerable attempts at pharmacologic and surgical intervention have been employed. Distinction between infarctive low-flow priapism with hypoxia and acidosis and normal-flow priapism without acidosis can be obtained using currently available imaging techniques. Cavernosonography and radionuclide scanning to assess penile hemodynamics are useful in determining whether priapism is of the low-flow type. Advances in our understanding of the physiology of erection have prompted a more physiologic approach to the assessment and management of priapism. Based on this technology, it would be possible to develop a prospective multiinstitutional study, thereby providing sufficient numbers of patients to better evaluate therapy. After the episode of priapism has abated and detumescence has occurred, we recommend that the patient be given the option of beginning a trial of hydroxyurea or another antisickling agent.

Use of doppler color flow imaging for differential diagnosis of vascular malformations: A preliminary report

Purpose: To ascertain whether Doppler color flow imaging can demonstrate the characteristics of blood flow within vascular lesions. Materials and Methods: Two cases with vascular malformation in the soft tissues of the maxillofacial region were examined. One was an arteriovenous, high-flow type malformation involving the tongue, the floor of the mouth, and the mandible. The other was a venous, low-flow type malformation of the whole tongue. The technique used was the same as that for the extraoral approach in conventional ultrasound imaging. Results: Doppler color flow imaging provided valuable information on the hemodynamic characteristics of the vascular malformations when comparing with other diagnostic forms of imaging, and clearly differentiated between high- and low-flow vascular lesions. Conclusion: Doppler color flow imaging was suggested to be another method in our armamentarium for differential diagnosis of vascular malformations.

Vascular malformations of the jaw bones: Report on nine patients

Nine patients with vascular malformations of the jaw bones, 4 affecting the mandible, 2 affecting both jaws and 3 affecting the maxilla only. Four lesions were of the high flow type and 5 were of low flow type. Our experience in the management of these lesions is presented together with the possible complications.