Vein Cannulation Research Articles

Internal jugular vein cannulation: A cause for vocal cord palsy - A case study.

Internal jugular vein cannulation: A cause for vocal cord palsy - A case study.

A safer approach for the axillary vein cannulation: a proposal.

A safer approach for the axillary vein cannulation: a proposal.

Use of a Novel Three-Dimensional Model to Teach Ultrasound-guided Subclavian Vein Cannulation.

Central venous cannulation is an essential skill in perioperative and critical care medicine. Ultrasound guidance is the standard of care for femoral and internal jugular vein access, with the subclavian vein being perceived to be less amenable to ultrasound-guided (UG) insertion, resulting in a lack of procedural competency and low cannulation rate. There is a paucity of resources and a lack of experience among staff physicians to effectively instruct trainees. Simulation-based medical education has the potential to help maintain high-stakes, infrequently performed skills and counteract possible unrecognized skill decline. We aimed to create a novel, low-cost, high-fidelity three-dimensional (3D) model for UG subclavian vein (UG-SCV) access with an accompanying curriculum to improve this important skill. A curriculum was created consisting of preparatory material reviewing UG-SCV access, followed by an in-person didactic lecture focusing on ultrasound use and management of complications and a deliberate practice session scanning volunteers and practicing UG vascular puncture on a 3D model. A qualitative usability test design was used to assess the validity of the curriculum in trainees with advanced vascular access skills (anesthesiologists). Participants were second-year anesthesia residents, anesthesia fellows, and staff physicians. Focus groups conducted after each session explored the face validity of the model and curriculum. By applying a usability design, the curriculum was optimized and finalized. Between September 2020 and February 2021, 28 participants tested the curriculum. The focus groups ensured that the curriculum achieved its objective, with iterative changes made after each session in a quality improvement framework Plan-Do-Study-Act approach. After the third cycle, minimal changes were suggested, and the curriculum and 3D model were finalized. An additional group of participants was used to ensure that no new input would help improve the curriculum further. A focused curriculum for enhancing skills in UG-SCV cannulation usinga novel 3D model was successfully implemented and validated through a usabilitytest design. This curriculum is better targeted for practitioners experienced incentral venous access to master a subclavian approach and maintain their skill level.

Comparison of ultrasound-guided and palpation-inserted peripheral venous cannula in -patients before primary hip or knee arthroplasty: study protocol for a randomized controlled trial

BackgroundMore than 2 billion peripheral vascular cannulas are introduced globally each year. It is the most frequently performed invasive procedure in medicine worldwide. There is a group of patients with difficult intravenous access (DIVA). In experts’ hands, ultrasound-guided vascular access appears to be a significantly better method. Investigators hypothesize that UGVA is superior also in short-term patency of cannula and even for blood draw through cannula. Repeated cannula pricks in the operating room setting not only puts a lot of stress on the patient and medical staff, but they also waste OR time.MethodsThis investigator-initiated prospective randomized monocentric controlled trial is designed to randomly allocate 200 patients undergoing elective primary total joint arthroplasty of hip or knee to one of two groups as follows: Group C (control group) – peripheral venous cannula insertion by palpation or Group USG (intervention) – cannula insertion by ultrasound-guided vascular access. Our primary endpoint is to compare the number of attempts for ultrasound-guided insertion of the peripheral venous cannula with common palpation insertion of the peripheral venous cannula in overweight/obese patients (BMI ≥ 25). The secondary endpoint is a failure rate of the peripheral venous cannula to administer intravenous therapy up to 5 days postoperatively. Tertiary endpoints include a portion of long PVCs that are able to ensure blood draw up to 5 days postoperatively, time needed to insert PVC in each group, number of needle tip redirections in both groups, and reinsertion of PVC needed in both groups for any reason.DiscussionThis study is pragmatic and is looking for clinically relevant data. After completion, it will answer the question of whether it is clinically relevant to use ultrasound-guided vascular access in the context of not only short-term benefit of insertion, but also up to 5 days after insertion. Also, if this method can ensure blood draw through a peripheral vein cannula, it can save resources in the perioperative period — valuable especially considering the ongoing shortage of medical staff worldwide. If this hypothesis is confirmed, this finding could contribute to more widespread implementation of ultrasound-guided peripheral vascular access in the perioperative period.Trial registrationClinicalTrials.gov NCT05156008. Registered on 13.12.2021.

Safety of mid-thigh exit site venous catheters in multidrug resistant colonized patients.

Venous catheters inserted in superficial femoral vein and with mid-thigh exit site have emerged as a feasible and safe technique for central or peripheral tip's venous access, especially in agitated, delirious patients. The spread of multidrug-resistant bacterial (MDR) strains is an emerging clinical problem and more and more patients are being colonized by these types of bacteria. The aim of this study is to evaluate the incidence of central line associated bloodstream infections (CLABSI) or catheter related bloodstream infections (CRBSI) in mid-thigh catheters in patients with positive rectal swabs to evaluate the safety of this procedure and the real infection risk. In this retrospective observational study, we analyzed data on patients with mid-tight catheters inserted from May 2021 to November 2022. All surveillance rectal swabs were recorded. In addition, to collect data on CLABSI and CRBSI, the results of all blood and catheter tip cultures performed during the hospital stay were acquired. Six hundred two patients were enrolled, 304 patients (50.5%) had a rectal swab; 128 (42.1%) swabs were positive for MDR. Nine CLABSI (only two in patients with a positive rectal swab) and three CRBSI were detected. No statistical difference in the absolute number of CLABSI and CRBSI and in the number of infections per 1000 catheter days emerged between the overall population and patients with positive rectal swabs (respectively p = 0.45 and p = 0.53). Similarly, no statistical difference in the number of CLABSI and CRBSI was found among patients with a negative swab and patients with a positive one (respectively p = 0.43 and p = 0.51). According to our data, cannulation of the superficial femoral vein represents a safe location in patients with positive rectal swabs.

Complex use of perfusion techniques in kidney transplantation from a donor with out-of-hospital cardiac arrest (clinical case)

Objective: to present the successful experience with a donor with out-of-hospital cardiac arrest (OHCA) in whom a set of modern perfusion techniques was used to obtain kidneys suitable for transplantation.Materials and methods. Automatic chest compression was resumed in an OHCA donor (after biological death has been confirmed in the hospital) to maintain minimal perfusion under mechanical ventilation with 100% FiO2. With femoral vein cannulation, an extracorporeal circuit with a centrifuge pump and oxygenator was connected and abdominal normothermic regional perfusion was initiated. After 215 minutes, kidney was explanted under normothermic machine perfusion. Next, the left kidney was placed in the LifePort Kidney Transporter for hypothermic machine perfusion of donor kidneys. Perfusion time was 285 minutes. The right kidney was transplanted without additional ex-vivo perfusion.Results. Due to the complex use of perfusion techniques both in the donor body and ex-vivo, donor kidneys, after OHCA, with a total warm ischemia time of 110 minutes, were transplanted to recipients with good results. In the postoperative period, there was delayed function of the left and right renal grafts. The patients were discharged in a satisfactory condition under outpatient follow-up.Conclusion. The possibility and efficiency of organ donation after OHCA, facilitated by modern perfusion techniques and devices, open up a new perspective in addressing the organ shortage crisis.

Can expiratory or inspiratory contrast-enhanced computed tomography be more efficient for fast-track cannulation of the right adrenal vein in adrenal venous sampling?

This study compares the usefulness of expiratory arterial phase (EAP)-contrast-enhanced computed tomography (CT) (CECT) with that of inspiratory arterial phase (IAP)-CECT in adrenal venous sampling (AVS). Sixty-four patients who underwent AVS and CECT at the authors' hospital between April 2013 and June 2019 were included in this study. The patients were classified into the following two groups: EAP (32 patients) and IAP (32 patients) groups. The single arterial phase images were obtained at 40 seconds in the IAP group. The double arterial phase images were obtained at 40 seconds in the early arterial phase and 55 seconds in the late arterial phase in the EAP group. The authors then compared the right adrenal vein (RAV) visualization rate on the CECT, the difference between the CECT images and adrenal venograms in the localization of the RAV orifice, the cannulation time to the RAV, and the volume of contrast agent administered intraoperatively between the two groups. The rates of the RAV visualization in the EAP group were 84.4% in the early arterial phase, 93.8% in the late arterial phase, and 100% in the combined early and late arterial phases. The rate of the RAV visualization in the IAP group was 96.9%. There was no significant difference between the two groups in terms of the rate of the RAV visualization. However, there was a small difference in the location of the RAV orifice between the CECT images and adrenal venograms in the EAP group as compared with the IAP group (P < 0.001). The median time to the RAV catheterization was significantly shorter in the EAP group (27.5 minutes) than in the IAP group (35.5 minutes; P = 0.035). The rates of the RAV visualization in the EAP group were not significant between the early arterial phase, late arterial phase, and combined early and late arterial phases (P = 0.066). However, the mean volume CT dose index in the combined early and late arterial phases was significantly higher than in the early and late arterial phases (P < 0.001). The EAP-CECT is more useful for increasing the speed of the RAV cannulation due to the small difference in the localization of the RAV orifice compared to IAP-CECT. However, since EAP-CECT has double contrast arterial phases and increased radiation exposure compared to IAP-CECT, only the late arterial phase may be acceptable to reduce radiation exposure.

Effect of head rotation on visualisation of carotid artery and jugular vein in ijv cannulation: an observational analytical study

Background: The relationship between the common carotid artery (CCA) and the internal jugular vein (IJV) plays a crucial role in the process of internal jugular vein (IJV) cannulation, and this relationship often undergoes changes with head rotation. Methods: In this analytical, observational study, we aimed to compare the effect of 15-degree and 45-degree head rotation on the visualization of the IJV and CCA among 30 patients undergoing IJV cannulation for central venous access. Ultrasound guidance was used during the cannulation procedure. Results: Our findings revealed that greater overlapping of the IJV, specifically at the 12 o'clock position, was observed in cases with a 45-degree head rotation, whereas a lesser degree of overlapping (IJV at the 10 o'clock position) was observed with head in the neutral position. Conclusion: Based on our observations, we conclude that maintaining a head neutral position during IJV central line insertion under ultrasound guidance is safer compared to a 45-degree neck rotation. This information can contribute to improved safety and efficacy during IJV cannulation procedures

Effect of head rotation on visualisation of carotid artery and jugular vein in ijv cannulation: an observational analytical study

Background: The relationship between the common carotid artery (CCA) and the internal jugular vein (IJV) plays a crucial role in the process of internal jugular vein (IJV) cannulation, and this relationship often undergoes changes with head rotation. Methods: In this analytical, observational study, we aimed to compare the effect of 15-degree and 45-degree head rotation on the visualization of the IJV and CCA among 30 patients undergoing IJV cannulation for central venous access. Ultrasound guidance was used during the cannulation procedure. Results: Our findings revealed that greater overlapping of the IJV, specifically at the 12 o'clock position, was observed in cases with a 45-degree head rotation, whereas a lesser degree of overlapping (IJV at the 10 o'clock position) was observed with head in the neutral position. Conclusion: Based on our observations, we conclude that maintaining a head neutral position during IJV central line insertion under ultrasound guidance is safer compared to a 45-degree neck rotation. This information can contribute to improved safety and efficacy during IJV cannulation procedures

Point‑of‑Care Ultrasound in internal medicine.

Point-of-Care ultrasound (POCUS) is bedside ultrasound examination performed by a clinician. POCUS is a suitable tool for rapid diagnosis and monitoring of the condition of many patients examined by internists in emergency departments and inpatient departments. POCUS allows the examining physician to supplement the physical examination with additional information obtained in real time, and is a useful tool for differential diagnosis of a number of acute conditions (shock, shortness of breath, etc.). Chest POCUS includes an indicative assessment of cardiac function and evaluation of the lung parenchyma, including exclusion of pericardial effusion, pneumothorax or fluidothorax. One of the most common applications of POCUS is to assess the state of the venous filling by examining the inferior vena cava. When examining the abdomen, the internist should at least be able to diagnose fluid in the abdominal cavity and exclude congestion in the hollow system of the kidney. POCUS for internists also includes examination of main venous trunks to rule out proximal venous thrombosis. Even when performing conventional invasive procedures, we cannot do without ultrasound at the bedside, whether it is a puncture of ascites or pleural effusion, or cannulation of the central vein. The advantage of POCUS is the immediate availability of the examination and the possibility to repeat scans when needed for monitoring the patient's condition.

Unilaterally Selective Adrenal Vein Sampling for Identification of Surgically Curable Primary Aldosteronism.

Adrenal venous sampling is recommended for the identification of unilateral surgically curable primary aldosteronism but is often clinically useless, owing to failed bilateral adrenal vein cannulation. To investigate if only unilaterally selective adrenal vein sampling studies can allow the identification of the responsible adrenal. Among 1625 patients consecutively submitted to adrenal vein sampling in tertiary referral centers, we selected those with selective adrenal vein sampling results in at least one side and surgically cured unilateral primary aldosteronism, used as gold reference. The accuracy of different values of the relative aldosterone secretion index (RASI), which estimates the amount of aldosterone produced in each adrenal gland corrected for catheterization selectivity, was examined. We found prominent differences in RASI values distribution between patients with and without unilateral primary aldosteronism. The diagnostic accuracy of RASI values estimated by the area under receiver operating characteristic curves was 0.714 and 0.855, respectively, in the responsible and the contralateral side; RASI values >2.55 and ≤0.96 on the former and the latter side furnished the highest accuracy for detection of surgically cured unilateral primary aldosteronism. Moreover, in the patients without unilateral primary aldosteronism, only 20% and 16% had RASI values ≤0.96 and >2.55. With the strength of a large real-life data set and use of the gold reference entailing an unambiguous diagnosis of unilateral primary aldosteronism, these results indicate the feasibility of identifying unilateral primary aldosteronism using unilaterally selective adrenal vein sampling results. URL: https://www. gov; Unique identifier: NCT01234220.

Incidentally portal vein penetration during cannulation in endoscopic retrograde cholangiopancreatography: a case report

Abstract Portal vein cannulation is a very rare complication of endoscopic retrograde cholangiopancreatography (ERCP). In most reported cases, the event was managed safely with immediate catheter, guidewire withdrawn and procedure termination. Here, we report an unusual case of portobiliary fistula created during ERCP. To our knowledge, this is the first report of such case managed with immediate surgical biliary exposure.

UNILATERALLY SELECTIVE ADRENAL VEIN SAMPLING FOR IDENTIFICATION OF SURGICALLY CURABLE PRIMARY ALDOSTERONISM

Objective: Adrenal venous sampling (AVS) is recommended for the identification of unilateral surgically curable primary aldosteronism (PA) but, owing to failed bilateral adrenal vein cannulation, is often clinically useless. Design and method: We investigated if only unilaterally selective AVS studies can allow identification of the responsible adrenal. Methods: Among 1625 patients consecutively submitted to AVS in tertiary referral centers, we selected those with a unilaterally selective AVS result and a final diagnosis of unilateral PA. Using the latter as gold reference, we examined the accuracy of the relative aldosterone secretion index (RASI), which estimates the amount of aldosterone produced in each adrenal gland corrected for catheterization selectivity. Results: The RASI values distribution showed prominent differences between patients with and without unilateral PA. The area under ROC curves (AUROC) was 0.714 and 0.855 for RASI values of the responsible and the contralateral side, respectively. While RASI values &gt;2.55 on the culprit side and less than 0.96 on the contralateral side furnished the highest accuracy for detection of surgically cured unilateral PA, only 20% and 16% had RASI values less than 0.96 and &gt;2.55, respectively, in the patients without unilateral PA. Conclusions: With the strength of the gold standard entailing an unambiguous diagnosis of unilateral PA and large real-life dataset, these results indicate the feasibility of identifying unilateral PA using unilaterally selective AVS results.

P96: Using Fenestrated Stent to Increase the Flow of ECMO of Superior Vena Cava Compression Syndrome

Introduction: Superior vena cava syndrome (SVCS) is an obstruction of the venous return to the heart through SVC or any other significant branches. The obstruction may be external, like thoracic mass compressing the SVC, or internal, like thrombosis or tumor, which directly invades the SVC. Patients experiencing a medical emergency after being initially stabilized require treatment for SVCS, including endovenous recanalization and the implantation of an SVC stent to reduce the risk of abrupt respiratory arrest and death. This case report details a situation in which reduced outflow in a VA ECMO would substantially improve by using a fenestrated stent of SVC. Case Presentation: A 54-year-old female presented to our medical center with weight loss and solid food dysphagia for three months. Chest CT scan showed a new mediastinal mass of 10x9x8cm with minor pericardial and pleural effusions. A transbronchial biopsy was attempted; however, the patient arrested during the bronchoscopy procedure. CPR was initiated, and the ECMO team was contacted for VA ECMO cannulation, which was done through the right femoral artery cannula size 15 Fr due to the narrowing of the artery, and the left femoral vein cannula size 23 Fr. ROSC was achieved, and the patient was transferred to the ICU. During the night shift, the ECMO flow was hard to maintain with fluids. First, that was due to the small arterial cannula. However, the issue was realized with the ECMO outflow volume issue. The next day, In the hybrid operating room, a fenestrated SVC stent was placed in SVC, brachiocephalic, and internal jugular veins (Figure 1). All patient hemodynamics improved post stenting, including ECMO, flows, especially outflow. Discussion: Endovenous treatment of SVC syndrome includes percutaneous transluminal balloon angioplasty (PTA), stenting, and thrombolysis performed alone or in combination. Stenting is usually in the SVC rather than several locations for SVC syndrome. However, our case is unique as the primary fenestrated stent was deployed in the SVC, and additionally, brachiocephalic and IJ veins were stented through the fenestration, which relieved the SVCS. In addition, it enhanced ECMO outflow flow instantly. Conclusion: This case illustrates that stenting in SVCS is a valid therapeutic option to increase ECMO flow in this patient group.Figure 1. Image A: Fluoroscopy showing SVC stenosis. Image B: redacted view of SVC fluoroscopy Image C: Balloon angioplasty of SVC stenosis under fluoroscopy. Image D: Fenestrated stent placement in the SVC under fluoroscopy. Image E: Stent deployed Internal jugular Image F: Post stenting image showing deployed brachiocephalic Internal jugular vein through fenestrations of primary stent.

Ultrasound-guidance for femoral venipuncture reduces access site complications after ablation of atrial fibrillation and other left atrial tachycardias: a retrospective single- center analysis

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Access site complications are significant adverse events related to ablation therapy. Periprocedural continuation of anticoagulation is common practice and leads to a reduction of cerebrovascular ischemic events but may increase the likelihood of access site complications. Methods 619 consecutive patients who underwent left-atrial ablation for AF were assessed for venipuncture associated complications after either landmark or ultrasound-guided venipuncture using data on hospital readmissions, outpatient visits or a structured telephone interview. AV-fistula, pseudoaneurysm and need of either interventional or surgical treatment of a vascular complication as well as blood transfusion were considered as access site complications. Continuous data are given as mean ± standard error of the mean, categorical data are expressed as number and percentages. Differences between groups were determined by Student’s t-test, chisquare-test, and Fisher’s exact test using SPSS software. A p-value of &amp;lt;0.05 was deemed significant. Results The patients' mean age was 69.1 ± 10.8 years and 51.5% were female. Mean BMI was 28.4 ± 5.5 kg/m2. Procedural safety was preserved with low observed rates of serious adverse events. The rate of postprocedural stroke (0.2% vs. 0%), pericardial effusion (0.8% vs. 0.6%) and in-hospital mortality (0% vs. 0%) did not differ between the groups. After conventional landmark-guided venipuncture the vascular complication rate was 4.8% (12/248). The rate of access site complications was significantly reduced to 0.8% (3/371) (p&amp;lt;0.01, OR 0.194, 95%-CI: 0.0529-0.712) when real time ultrasound-imaging was used for femoral venous cannulation. Severe bleeding complications related to the access site that required surgical or interventional treatment did not occur in the ultrasound group, compared to 2.0% (5/248) in the landmark-guided group (p = 0.010). The absolute risk reduction for access site complications using ultrasound-guidance was 3.2%, resulting in a number needed to treat (NNT) of 32 and a NNT of 50 for severe access site complications. Discussion Ultrasound-imaging while performing venipuncture identifies complex or uncommon anatomical conditions and facilitates safe cannulation of the common femoral vein. The use of ultrasound visual guidance for femoral sheath introduction had a remarkable beneficial effect on the occurrence of vascular access site complications in this retrospective single-center analysis. Outstandingly, the total rate of vascular access site complications had been significantly reduced resulting in a reduction of interventional or surgical treatment down to 0,0% in the us-guidance group, this may lead to fewer interruptions of OAC ant therefore lower risk of peri-interventional cerebrovascular events.

NENA Position Statement: Ultrasound Guidance for Peripheral Intravenous Cannulation

Ultrasound guidance can increase peripheral vein cannulation success by nurses in the Emergency Department (ED). Unfortunately, ED nurses are not routinely trained to use ultrasonography for peripheral vein cannulation and may not have access to the required equipment.

Comparison between in-plane and out-of-plane techniques for ultrasound guided cannulation of the left brachiocephalic vein in pediatric population: A randomised controlled trial

Background and aimsBrachiocephalic vein is a novel site for central venous cannulation in infants. It becomes useful in patients where the internal jugular vein lumen is small (e.g., volume deficient patient), patients with a history of multiple cannulations, and in whom subclavian puncture is contraindicated. MethodsIn this randomized double-blinded study, 100 patients, aged between 0 and 1 year scheduled for elective central venous cannulation were recruited. The patients were allocated into two groups (50 patients in each). Group I patients had ultrasound (US) guided cannulation of the left brachiocephalic vein (BCV) by inserting a needle in-plane to the US probe from lateral to the medial direction, whereas Group II patients underwent cannulation of the BCV via an out-of-plane approach. ResultsThe first-attempt success rate was significantly higher in Group I (74%) than in Group II (36%) (p < 0.001). The total success rate was higher in group I (98%) than in group II (88%) however the difference was statistically insignificant (p > 0.05). The mean BCV cannulation time was significantly shorter in group I (35.46 ± 25.10) than in group II (65.24 ± 40.26) (p < 0.001). The rate of unsuccessful BCV cannulation (12%) and hematoma development (12%) was significantly higher in group II than in group I (2%). ConclusionCompared to the out-of-plane approach of left BCV cannulation, US-guided in-plane cannulation of the left BCV increased the first-attempt success rate, decreased the number of puncture attempts, and decreased the time required for cannulation.

Real-time ultrasound-guided versus landmark-guided subclavian vein catheterization in the intensive care unit: a prospective randomized study

Abstract Background The subclavian vein (SCV) is an alternative to the internal jugular vein when it is difficult to locate, such as in patients with hypovolemia or obesity. Ultrasonography (USG) guidance for SVC cannulation has evolved, resulting in fewer complications and higher first-pass success rates. This study aimed to compare the effectiveness and safety of SCV cannulation with USG- and landmark-guided techniques. Methods In this prospective randomized interventional controlled study, 80 patients admitted to the intensive care unit between July 2022 and October 2022 were randomly assigned to the landmark method group (LM group) and USG group. In the LM group, SCV cannulation was performed using the traditional landmark technique, whereas in the USG group, it was performed using USG guidance. The primary objective of this study was to evaluate the ease of subclavian central venous cannulation in critically ill patients using the 2 techniques. The secondary objectives were to compare the success rate of cannulation between these 2 techniques, evaluate the number of attempts, assess cannulation failure, and assess mechanical complications. Results The first-pass success rates were 70% and 92.5% in the LM and USG groups, respectively (P &lt; 0.001). The average numbers of attempts in the LM and USG groups were 1.275 (±0.520) and 1.075 (±0.266), respectively (P = 0.034). The average procedure durations were 7.45 (±1.10) and 8 (±0.933) minutes in the LM and USG groups (P = 0.018), respectively. The rates of complications in both groups were not statistically significant. Conclusion The USG guidance for SCV cannulation has an advantage over landmark-guided methods in a critical care setting. The SCV is a good alternative to internal jugular vein cannulation. The average time to cannulation was longer in the USG group than in the LM group, which can decrease with the frequent use of USG and increasing operator experience. Clinical trials This study was registered in the Clinical Trials Registry-India (CTRI Trial No. CTRI/2022/07/043694, dated May 7, 2022).

Measurement of hippocampal arteriolar diameter and blood velocity in awake head-fixed mice

Cerebral hypoperfusion is associated with neurodegeneration. However, the influence of disease on the microcirculation of specific brain regions is poorly understood. In the current study, we validated a technical approach that allows us to simultaneously image arteriolar diameter and blood velocity in the hippocampi of awake, head-fixed mice. The approach involved implanting a gradient-Index (GRIN) lens into the hippocampus and cementing it in place together with a steel head-fixation bar. Imaging was performed after 7-14 days recovery. On the day of imaging, we intravenously administered Alexa Fluor 633 hydrazide (1.25 mg/kg) to label arterioles, and after 90 minutes, secured the mice on a custom-built stage of a widefield fluorescence microscope. We measured blood velocity in parallel with vessel diameter by imaging fluorescent latex beads infused by tail vein cannulation. Vessel diameter and blood velocity were assessed in 14 vessels from 6 mice. Hypercapnia induces cerebral vasodilation and increases cerebral blood flow. In our experiments, inhalation of 10% CO 2 caused a 12.1 ± 6% (mean ± SEM) increase in vessel diameter and a significant (P&lt;0.01, student’s t-test) increase in blood velocity from 1.09 ± 0.1 to 1.73 ± 0.2 cm/s (mean ± SEM). These data demonstrate the feasibility of this approach to assess microvascular function and perfusion in highly localized brain regions. NIH grant (HL142906) This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Sheath-Based Combined Foam Sclerotherapy to Promote Management of Extensive Insufficiency of the Great Saphenous Vein in Venous Ulcers.

Background: Foam sclerotherapy is considered an acceptable method to treat great saphenous vein (GSV) insufficiency, promoting occlusion of its trunk and eradicating reflux. Various modalities and techniques have been described, varying form foam infusion through multiple short cannulae along the GSV to catheter-directed techniques in order to facilitate complete proximal GSV occlusion and improve technical and clinical success. Purpose: To present a modification of the sclerotherapy tehcnique where the presence of venous ulcers poses an extra challenge to the treatment of GSV treatment. Technique: We describe a technical proposal of single foam perfusion through a 11cm 5F sheath placed at the knee level combined with simultaneous retrograde infusion below the knee. Perivenous tumescent segmental infiltration with cold normal saline at 4°C is applied initially to reduce the diameter in those GSV >6-7mm. Conclusions: This combination avoids multiple vein cannulation in the GSV along the thigh as well as the need for antegrade infusion when GSV cannulation at the lower tibia is prohibited by a large ulcer area.