Comparison between the outcomes of transfemoral access and transfemoral access with adjunct upper extremity access in patients undergoing endovascular aortic repair: A pilot systematic review and meta-analysis

Endovascular aortic repair is an emerging novel intervention for the management of abdominal aortic aneurysms. It is crucial to compare the effectiveness of different access sites, such as transfemoral access (TFA) and upper extremity access (UEA). An electronic literature search was conducted using PubMed, EMBASE, and Google Scholar databases. The primary endpoint was the incidence of stroke/transient ischemic attack (TIA), while the secondary endpoints included technical success, access-site complications, mortality, myocardial infarction (MI), spinal cord ischemia, among others. Forest plots were constructed for the pooled analysis of data using the random-effects model in Review Manager, version 5.4. Statistical significance was set at p < 0.05. Our findings in 9403 study participants (6228 in the TFA group and 3175 in the UEA group) indicate that TFA is associated with a lower risk of stroke/TIA [RR: 0.55; 95% CI: 0.40-0.75; p = 0.0002], MI [RR: 0.51; 95% CI: 0.38-0.69; p < 0.0001], spinal cord ischemia [RR: 0.41; 95% CI: 0.32-0.53, p < 0.00001], and shortens fluoroscopy time [SMD: -0.62; 95% CI: -1.00 to -0.24; p = 0.001]. Moreover, TFA required less contrast agent [SMD: -0.33; 95% CI: -0.61 to -0.06; p = 0.02], contributing to its appeal. However, no significant differences emerged in technical success [p = 0.23], 30-day mortality [p = 0.48], ICU stay duration [p = 0.09], or overall hospital stay length [p = 0.22]. Patients with TFA had a lower risk of stroke, MI, and spinal cord ischemia, shorter fluoroscopy time, and lower use of contrast agents. Future large-scale randomized controlled trials are warranted to confirm and strengthen these findings.

Long-term functional outcomes of upper extremity civilian vascular trauma

OBJECTIVE

Civilian analyses of long-term outcomes of upper extremity vascular trauma (UEVT) are limited. Our goal was to evaluate the management of UEVT in the civilian trauma population and explore the long-term functional consequences.

METHODS

A retrospective review and analysis was performed of patients with UEVT at an urban Level 1 trauma center (2001-2022). Management and long-term functional outcomes were analyzed.

RESULTS

There were 150 patients with UEVT. Mean age was 34 years, and 85% were male. There were 42% Black and 27% White patients. Mechanism was penetrating in 79%, blunt in 20%, and multifactorial in 1%. Within penetrating trauma, mechanism was from firearms in 30% of cases. Of blunt injuries, 27% were secondary to falls, 13% motorcycle collisions, 13% motor vehicle collisions, and 3% crush injuries. Injuries were isolated arterial in 62%, isolated venous in 13%, and combined in 25% of cases. Isolated arterial injuries included brachial (34%), radial (27%), ulnar (27%), axillary (8%), and subclavian (4%). The majority of arterial injuries (92%) underwent open repair with autologous vein bypass (34%), followed by primary repair (32%), vein patch (6.6%), and prosthetic graft (3.3%). There were 23% that underwent fasciotomies, 68% of which were prophylactic. Two patients were managed with endovascular interventions; one underwent covered stent placement and the other embolization. Perioperative reintervention occurred in 12% of patients. Concomitant injuries included nerves (35%), bones (17%), and ligaments (16%). Intensive care unit admission was required in 45%, with mean intensive care unit length of stay 1.6 days. Mean hospital length of stay was 6.7 days. Major amputation and in-hospital mortality rates were 1.3% and 4.6% respectively. The majority (72%) had >6-month follow-up, with a median follow-up period of 197 days. Trauma readmissions occurred in 19%. Many patients experienced chronic pain (56%), as well as motor (54%) and sensory (61%) deficits. Additionally, 41% had difficulty with activities of daily living. Of previously employed patients (57%), 39% experienced a >6-month delay in returning to work. Most patients (82%) were discharged with opioids; of these, 16% were using opioids at 6 months.

CONCLUSIONS

UEVT is associated with long-term functional impairments and opioid use. It is imperative to counsel patients prior to discharge and ensure appropriate follow-up and therapy.

Arterial diameter ratio as a reliable predictor for upper limb steal syndrome in patients with arteriovenous fistula for hemodialysis

OBJECTIVES

The aim of this study is to assess the association between the anastomosis diameter enlargement and steal syndrome incidence in patients with upper limb arteriovenous fistula using ratios as reliable predictors.

MATERIAL AND METHODS

An analytical cross-sectional prospective study was conducted. A total of 49 patients with AVF hemodialysis access were recruited. Twenty-four participants with positive steal syndrome and 25 control were enrolled in the study. Anastomosis diameter, anastomosis diameter ratio, and volume flow ratio were measured ultrasonographically by two expert vascular sonographers. These clinical parameters were recorded and analyzed to assess the difference and association. Patient risk factors and steal syndrome association were emphasized.

RESULTS

The study analysis indicates a strong association in the anastomosis diameter and anastomosis diameter ratio between steal and non-steal patients with a p-value ≤0.05. Additionally, there was a significant increase in the volume flow ratio in the patients with steal syndrome compared to the control group (p-value ≤0.05). There was a strong relationship between steal syndrome and the presence of peripheral arterial disease (73.9%, p = 0.001). The ICC index of absolute agreement between the two observers was ICC= 0.99 (95% CI 0.99-0.99, n = 10), indicating excellent agreement between observers.

CONCLUSION

Anastomosis diameter and volume flow ratio strongly suggest that steal syndrome is associated with the increased diameter of anastomosis. Patients with a≥1.05 anastomosis diameter ratio have a greater risk of developing steal syndrome than those with an anastomosis ratio of ≤0.8. In addition, patients with a volume flow ratio ≥0.98 have an increased risk of developing steal syndrome than those with a volume flow ratio of ≤0.75.

Comparison of Lower and Upper Extremity Arteriovenous Graft: A Retrospective Clinical Analysis with 5-Year Follow-Up

BACKGROUND

For patients in whom an upper extremity (UE) vascular access cannot be established, the lower extremity (LE) arteriovenous graft (AVG) could be selected. However, the application of LE AVG is limited owing to its high infection rate, uncertain patency time, and technical difficulties. This study aimed to compare the long-term patency rates and the incidence of vascular access complications of AVG in the LE and UE to provide a reference for the applications of AVG, especially in the LEs.

METHODS

This was a retrospective analysis of patients who successfully underwent LE or UE AVG placement from March 2016 to October 2021. Patient characteristics were collected and compared using parameter or nonparameter tests according to data type. Postoperative patency was evaluated using Kaplan-Meier test. Postoperative complication incidence density and intergroup comparison were estimated using the Poisson distribution.

RESULTS

Twenty-two patients with LE AVG and 120 patients with UE AVG were included. The 1-year primary patency rate was 67.4% (±11.0% standard error [SE]) in the LE group and 30.1% (±4.5% SE) in the UE group (P = 0.031). The assisted primary patency rate at postoperative months 12, 24, and 36 was respectively 78.6% (±9.6% SE), 65.5% (±14.4% SE), and 49.1% (±17.8% SE) in the LE group and 63.3% (±4.6% SE), 47.5% (±5.4% SE), and 30.4% (±6.1% SE) in the UE group (P = 0.137). The secondary patency rate at postoperative months 12, 24, and 36 remains 95.5% (±4.4% SE) in the LE group and 89.3% (±2.9% SE), 83.7% (±3.9% SE), and 73.0% (±6.2% SE), respectively, in the UE group (P = 0.200). Postoperative complications included stenosis, occlusion/thrombosis, infection, steal syndrome, pseudoaneurysm, severe postoperative serum swelling, and AVG exposure. The total incidence rates of postoperative complications were 0.87 (95% confidence interval [CI] 0.59-1.23) versus 1.61 (95% CI 1.45-1.79) (P = 0.001) cases/person-year, the incidence rates of stenosis were 0.45 (95% CI 0.26-0.73) versus 0.92 (95% CI 0.80-1.06) (P = 0.005) cases/person-year and the incidence rates of occlusion/thrombosis were 0.34 (95% CI 0.17-0.59) versus 0.62 (95% CI 0.52-0.74) cases/person-year in the LE group compared to those in the UE group (P = 0.041).

CONCLUSIONS

LE AVG had higher primary patency rate and lower postoperative complication incidence than UE AVG. With the development of interventional technology, both LE AVG and UE AVG exhibited high secondary patency rates. LE AVG can be a reliable and long-term alternative for appropriately selected patients with unusable UE vessels.

Effect of exercises on the maturation of newly created arteriovenous fistulas over distal and proximal upper limb: A systematic review and meta-analysis

The aims of our review were: (i) to evaluate the effect of post-operative upper extremity exercise on maturation of AVFs, stratified by their locations. (ii) To evaluate the effect of pre-operative arm exercise on patients' superficial vein caliber of patients. Literature search was performed on PubMed, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and China National Knowledge Infrastructure (CNKI) to identify eligible articles. The quality of the randomized controlled trials (RCTs) were assessed using the Cochrane Risk of Bias tool 2.0. In the Meta-analysis, Risk ratios (RRs) of clinical maturation and ultrasonographic maturation were pooled from studies focused on post-operative exercise program; Mean difference (MD) of venous caliver was pooled from those studied pre-operative exercise. Nine studies (six for post-operative exercise; three for pre-operative exercise) were included in the review. Among the AVFs created in distal region (158 patients in exercise group and 144 patients in control group), there was a significantly superior clinical maturation (RR: 1.28; 95% CI: 1.10-1.48, p = 0.001; I2 = 0), and ultrasonographic maturation (RR: 1.30; 95% CI: 1.07-1.59, p = 0.009; I2 = 0) in the exercise group in comparison to the control group. For the AVFs created in proximal region (93 and 96 patients in exercise group and control group respectively), there is no significant difference in clinical maturation (RR:1.25, 95% CI: 0.88-1.78, p = 0.27, I2 = 74%) and ultrasonographic maturation (RR: 1.17, 95% CI: 0.97-1.40, p = 0.11, I2 = 43%) between the exercise group and controls. For pre-operative exercise, the mean difference of 0.34 mm (95% CI: 0.23-0.46, p < 0.001, I2 = 87% ) was found for vein size. In conclusion, existing upper extremity exercise programs appear to be useful in facilitating maturation of AVFs created in distal region, while its effect on fistulas created in proximal region is less certain. However, more robust trials are warranted to establish these findings.

Exercise guide to help on arteriovenous fistula maturation and maintenance

BACKGROUND

The arteriovenous fistula is the main vascular access in hemodialysis. Arteriovenous fistula access is generally evaluated by a vascular surgeon after 2 weeks of its surgery, however, exercise programs may begin earlier for improving outcomes. Therefore, we propose this guide with simple, but potentially effective exercises, using low-cost materials that can be safely performed by the patients at home or in the dialysis center. It also provides to the dialysis staff team a starting point for implementing an upper-limb exercise program that may facilitate arteriovenous fistula maturation and maintenance.

METHODS

This exercise routine for arteriovenous fistula maturation can be performed three to four times a day, every day, from 2 to 4 weeks. After its maturation, it can be performed on every non-dialysis day for conventional treatment and every other day, before dialysis, for short daily treatment.

CONCLUSIONS

Based on the available evidence, we have gathered some exercises, in a very easy and understandable language, that may potentially help arteriovenous fistula maturation and maintenance for hemodialysis patients.

Outcomes of upper arm axillary artery and brachial artery arteriovenous grafts

BACKGROUND

We compared the outcomes of upper arm arteriovenous grafts (AVGs) in a large, prospectively collected data set to determine if there are clinically significant differences in axillary artery-based and brachial artery-based AVGs.

METHODS

Patients who received upper arm AVGs within the Society of Vascular Surgery Vascular Quality Initiative (VQI) dataset were identified. The primary outcome measures were primary and secondary patency loss at 12-month follow-up. Other outcomes included were wound infection, steal syndrome, and arm swelling at 6-month follow-up. The log-rank test was used to evaluate patency loss using Kaplan-Meier analysis, and Cox proportional hazards models were used to examine adjusted association between inflow artery (brachial artery vs axillary artery) and outcomes, adjusting for configuration (straight vs looped).

RESULTS

Among 3637 upper extremity AVGs in the VQI (2010-2017), there were 510 upper arm brachial artery AVGs and 394 upper arm axillary artery AVGs. Patients with axillary artery AVGs were more likely to be female (72% vs 56%, p < 0.001) and underwent general anesthesia (61% vs 57%, p < 0.05). In univariable analysis, the 12-month primary patency (54% vs 63%, p = 0.03) and secondary patency (81% vs 89%, p = 0.007) were lower for axillary artery AVGs than upper arm brachial artery AVGs. In multivariable analysis, although wound infection and arm swelling were similar at 6-month follow up, axillary artery AVGs were more likely to have steal syndrome (adjusted Hazard Ratio (aHR) = 2.6, 95% Confidence Interval (CI) 1.2,5.6, p = 0.017). In addition, axillary artery AVGs were associated with higher rates of 12-month primary patency loss (aHR = 1.6, 95% CI 1.2-2.2, p = 0.002) and 12-month secondary patency loss (aHR = 2.0, 95% CI 1.3-3.3, p = 0.005).

CONCLUSIONS

From this observational study analyzing the outcomes of upper extremity hemodialysis access, axillary artery AVGs were associated with significantly lower patency rates and higher risk of steal syndrome than brachial artery AVGs.

Upper Extremity Access Has Worse Outcomes in F/BEVAR Using the VQI Dataset

BACKGROUND

Physician-modified endografts and custom-manufactured devices use branched and fenestrated techniques (F/BEVAR) to repair complex aneurysms. Traditionally, many of these are deployed through a combination of upper and lower extremity access. However, with newer steerable sheaths, you can now simulate upper extremity (UEM) access from a transfemoral approach. Single-institution studies have demonstrated increased risks of access site complications and stroke when UEM access is used. This study compares outcomes after F/BEVAR in a national database between total transfemoral (TTF) access and mixed UEM access.

METHODS

This study is an analysis of the Vascular Quality Initiative for all patients who underwent F/BEVAR from 2014 to 2021. Patients were stratified based on a TTF delivery of all devices versus any UEM access for deployment of target vessel stents. Primary outcomes included stroke, myocardial infarction (MI), and perioperative death. Secondary outcomes included access site hematoma, occlusion or embolization, operative time, fluoroscopy time, and technical success. Multivariable linear and logistic regression analyses were performed.

RESULTS

Three thousand one hundred forty six patients underwent an F/BEVAR: 2,309 (73.4%) TTF and 837 (26.6%) UEM. Logistic regression analysis indicated a two-fold increased risk of death and MI and a three-fold increased risk of stroke in the UEM group. Furthermore, there is decreased operative time (221 vs. 297 min, P < 0.001) and fluoroscopy time (62 vs. 80 min, P < 0.001) in the TTF group and no difference in technical success between groups (96% vs. 97%, P = 0.159). Finally, there was a decrease in access site hematoma 2.54% vs. 4.31% (P = 0.013), access site occlusion 0.61% vs. 1.91% (P = 0.001), and extremity embolization 2.17% vs. 3.58% (P = 0.026) in the TTF versus UEM group.

CONCLUSIONS

This study using Vascular Quality Initiative data demonstrates that patients who undergo an F/BEVAR using UEM access have an increased risk of perioperative MI, death, and stroke compared to TTF access.

Two-Stage Offers No Advantages over Single-Stage Arteriovenous Creation: An Analysis of Multicenter National Data

BACKGROUND

Traditionally, arteriovenous fistulas (AVF) involving the basilic vein (BV) have been created in 1 or 2 stages to allow time for the vein to enlarge before superficialization for potential better fistula maturation. Previous single institution studies and meta-analyses have found conflicting outcomes between single-stage and 2-stage procedures. Our study aims to use a large national database to assess the difference in outcomes between single-stage and 2-stage procedures for dialysis access.

METHODS

We studied all patients undergoing BV AVF creation in the Vascular Quality Initiative (VQI) from 2011 to 2021. Patients were split into single-stage or a planned 2-stage procedure for dialysis access. Primary outcomes included dialysis use with index fistula, maturity rate, and number of days from surgery to fistula use. Secondary outcomes included patency (defined by physical exam or imaging on follow-up), 30-day mortality, and postoperative complications (bleeding, steal syndrome, thrombosis, or neuropathy). Logistic regression models were used to assess the association between staged dialysis access procedures and primary outcomes of interest.

RESULTS

The cohort consisted of 22,910 individuals of which 7,077 (30.9%) had a 2-staged dialysis access procedure and 15,833 (69.1%) had a single-staged procedure. Average follow-up was 345 days in the single stage and 420 days for 2-stage. Baseline characteristics were significantly different between the 2 groups in terms of medical comorbidities. Primary outcomes were significant for more patients in the 2-stage group undergoing dialysis with the index fistula compared to single stage (31.5% vs. 22.2%, P < 0.0001), significant decrease in days to use in current dialysis patients (103.9 days single stage versus 141.0 days 2-stage, P < 0.0001), and no difference in maturity at follow-up (19.3% single-stage and 17.4% 2-stage, P = 0.354). Secondary outcomes revealed no difference in 30-day mortality or patency (89.8% single-stage and 89.1% 2-stage, P = 0.383), but a significant difference in postoperative complications with a 2-stage procedure compared to 1-stage (1.6% vs. 1.1%, P = 0.026). Finally, a spline model was used to determine that a preoperative vein of 3 mm or less could be a cutoff in which a 2-stage procedure might be beneficial.

CONCLUSIONS

This study demonstrates that when dialysis access fistulas are created using the BV, there is no difference in maturity rate or 1-year patency when assessing single-stage versus 2-stage procedures. However, 2-stage procedures significantly delay the time of first use of the fistula and increase postoperative complications. Therefore, we suggest performing single stage procedures when the vein is of appropriate diameter to minimize multiple procedures, complications and expedite time to maturity.

Technical outcomes of below-the-elbow revascularization for upper extremity critical limb ischemia

OBJECTIVES

This study aims to report the technical results of below-the-elbow arterial revascularization in patients with critical hand ischemia.

METHODS

We retrospectively identified upper extremity critical limb ischemia patients treated with below-the-elbow arterial intervention between 2013 and 2017. Patient demographics, comorbidities, and procedural data were reviewed and technical success was evaluated.

RESULTS

Seven patients with 12 arteries that were affected by critical hand ischemia were treated. All patients had a history of end-stage renal disease. The technical success rate was 83.3%. There were no major or minor complications. The average follow-up duration was 9 months (2-26 months). One patient underwent a digital amputation at 8 months.

CONCLUSION

Arterial revascularization of the below-the-elbow arteries for critical hand ischemia is safe and technically feasible.

Use of chronically occluded fistula to establish access outflow

Maintaining a good quality vascular access in the long term can become particularly challenging especially in patients that are on dialysis for many years and present with exhausted venous capital and chronic access related complications. We present a 60-year-old female patient with multiple bilateral previous failed accesses, a previous distal revascularization interval ligation (DRIL) for hemodialysis access induced distal ischemia (HAIDI). Her chronically (more than a month) occluded arteriovenous fistula AVF was used to establish outflow and create a functioning forearm arteriovenous graft (AVG).

The use of AVF.SIM system for the surgical planning of arteriovenous fistulae in routine clinical practice

BACKGROUND

The number of patients treated with hemodialysis (HD) in Europe is more than half a million and this number increases annually. The arteriovenous fistula (AVF) is the vascular access (VA) of first choice, but the clinical outcome is still poor. A consistent number of AVFs fails to reach the desired blood flow rate for HD treatment, while some have too high flow and risk for cardiac complications. Despite the skill of the surgeons and the possibility to use Ultrasound investigation for mapping arm vasculature, it is still not possible to predict the blood flow volume that will be obtained after AVF maturation.

METHODS

We evaluated the potential of using a computational model (AVF.SIM) to predict the blood flow volume that will be achieved after AVF maturation, within a multicenter international clinical investigation aimed at assessing AVF.SIM predictive power. The study population included 231 patients, with data on AVF maturation in 124 patients, and on long-term primary patency in 180 patients.

RESULTS

At 1 year of follow-up, about 60% of AVFs were still patent, with comparable primary patency in proximal and distal anastomosis. The correlation between predicted and measured blood flow volume in the brachial artery at 40 days after surgery was statistically significant, with an overall correlation coefficient of 0.58 (p < 0.001). The percent difference between measured and predicted brachial blood flow 40 days after surgery was less than 30% in 72% of patients investigated.

CONCLUSIONS

The results indicate that the use of the AVF.SIM system allowed to predict with a good accuracy the blood flow volume achievable after VA maturation, for a given location and type of anastomosis. This information may help in AVF surgical planning, reducing the AVFs with too low or too high blood flow, thus improving AVF patency rate and clinical outcome of renal replacement therapy.

VAVASC study: Clinical trial protocol

BACKGROUND

VAVASC study (Validation of Arterio Venous Access Stage Classification) is a multicentre, international, prospective study. The study aims to validate the AVAS classification, which is a classification system describing vascular status of patients indicated for creation of arteriovenous access on the upper limb.

METHODS

Observational, prospective, multicentre, international study starting in March 2021. Participant recruitment has commenced. Basic demographic data, risk factors and vascular mapping parameters are collected via an online platform. The outcome measures are class of AVAS, predicted arteriovenous access, final arteriovenous access that has been created and a functionality of the arteriovenous access. Predictive models will be used for statistical analysis.

CURRENT STATUS

A total of 140 patients from 4 centres in Great Britain, Czech Republic, Brazil and Slovakia are already included and undergoing evaluation.

CONCLUSIONS

The study is registered in the Clinical trials registry (NCT04796558), https://register.clinicaltrials.gov/. Study is still open for collaboration with other centres that can register via www.vavasc.com.

Multicentre International Registry of Open Surgical Versus Percutaneous Upper Extremity Access During Endovascular Aortic Procedures

OBJECTIVE

To investigate access failure (AF) and stroke rates of aortic procedures performed with upper extremity access (UEA), and compare results of open surgical vs. percutaneous UEA techniques with closure devices.

METHODS

A physician initiated, multicentre, ambispective, observational registry (SUPERAXA - NCT04589962) was carried out of patients undergoing aortic procedures requiring UEA, including transcatheter aortic valve replacement, aortic arch, and thoraco-abdominal aortic endovascular repair, pararenal parallel grafts, renovisceral and iliac vessel repair. Only vascular procedures performed with an open surgical or percutaneous (with a suture mediated vessel closure device) UEA were analysed. Risk factors and endpoints were classified according to the Society for Vascular Surgery and VARC-3 (Valve Academic Research Consortium) reporting standards. A logistic regression model was used to identify AF and stroke risk predictors, and propensity matching was employed to compare the UEA closure techniques.

RESULTS

Sixteen centres registered 1 098 patients (806 men [73.4%]; median age 74 years, interquartile range 69 - 79 years) undergoing vascular procedures using open surgical (76%) or percutaneous (24%) UEA. Overall AF and stroke rates were 6.8% and 3.0%, respectively. Independent predictors of AF by multivariable analysis included pacemaker ipsilateral to the access (odds ratio [OR] 3.8, 95% confidence interval [CI] 1.2 - 12.1; p = .026), branched and fenestrated procedure (OR 3.4, 95% CI 1.2 - 9.6; p = .019) and introducer internal diameter ≥ 14 F (OR 6.6, 95% CI 2.1 - 20.7; p = .001). Stroke was associated with female sex (OR 3.4, 95% CI 1.3 - 9.0; p = .013), vessel diameter > 7 mm (OR 3.9, 95% CI 1.1 - 13.8; p = .037), and aortic arch procedure (OR 7.3, 95% CI 1.7 - 31.1; p = .007). After 1:1 propensity matching, there was no difference between open surgical and percutaneous cohorts. However, a statistically significantly higher number of adjunctive endovascular procedures was recorded in the percutaneous cohort (p < .001).

CONCLUSION

AF and stroke rates during complex aortic procedures employing UEA are non-negligible. Therefore, selective use of UEA is warranted. Percutaneous access with vessel closure devices is associated with similar complication rates, but more adjunctive endovascular procedures are required to avoid surgical exposure.

Contemporary management and time to revascularization in upper extremity arterial injury

INTRODUCTION

Upper extremity arterial injury is associated with significant morbidity and mortality for trauma patients, but there is a paucity of data to guide the clinician in the management of these injuries. The goals of this review were to characterize the demographics, presentation, clinical management, and outcomes, and to evaluate how time to intervention associates with outcomes in trauma patients with upper extremity vascular injuries.

METHODS

The National Trauma Data Bank (NTDB) Research Data Set for the years 2007-2016 was queried in order to identify adult patients (age ≥ 18) with an upper extremity arterial injury. Patients with brachiocephalic, subclavian, axillary, or brachial artery injury using the 1998 and 2005 versions of the Abbreviated Injury Scale were included. Patients with non-survivable injuries to the brain, traumatic amputation, or other major arterial injuries to the torso or lower extremities were excluded.

RESULTS

The data from 7908 patients with upper extremity arterial injuries was reviewed. Of those, 5407 (68.4%) underwent repair of the injured artery. The median Injury Severity Score (ISS) was 10 (IQR = 7-18), and 7.7% of patients had a severe ISS (≥ 25). Median time to repair was 120 min (IQR = 60-240 min). Management was open repair in 52.3%, endovascular repair in 7.3%, and combined open and endovascular repairs in 8.8%; amputation occurred in 1.8% and non-operative management was used in 31.6% of patients. Blunt mechanism of injury, crush injury, concomitant fractures/dislocations, and nerve injuries were associated with amputation, whereas simultaneous venous injury was not. There was a significant decrease in the rate of amputation when patients undergoing surgical revascularization did so within 90 min of injury (P = 0.007).

CONCLUSION

Injuries to arteries of the upper extremity are managed with open repair, endovascular repair, and, rarely, amputation. Expeditious transport to the operating room for revascularization is the key for limb salvage.

Effects of percutaneous transluminal angioplasty and associated factors in access hand oxygenation in patients undergoing hemodialysis

In hemodialysis (HD) patients with arteriovenous fistula (AVF), changes in systemic or peripheral tissue circulation occur non-physiologically via the presence of AVF; however, associations between blood flow and tissue oxygenation in the brain and access hand are uncertain. In this study, 85 HD patients with AVF were included and evaluated for changes in flow volume (FV) and regional oxygen saturation (rSO₂) in the brain and hands with AVF before and after percutaneous transluminal angioplasty (PTA). Furthermore, we evaluated the factors that determine access hand rSO₂ without stenosis after PTA. Brachial arterial FV increased after PTA (p < 0.001), and carotid FV decreased (p = 0.008). Access hand rSO₂ significantly decreased after PTA (p < 0.001), but cerebral rSO₂ did not significantly change (p = 0.317). In multivariable linear regression analysis of factors associated with access hand rSO₂, serum creatinine (standardized coefficient: 0.296) and hemoglobin (standardized coefficient: 0.249) were extracted as independent factors for access hand rSO₂. In conclusion, a decrease in access hand oxygenation and maintenance of cerebral oxygenation were observed throughout PTA. To maintain access hand oxygenation, it is important to adequately manage Hb level and maintain muscle mass, in addition to having an AVF with appropriate blood flow.

Effect of Remote Ischemic Conditioning vs Usual Care on Neurologic Function in Patients With Acute Moderate Ischemic Stroke: The RICAMIS Randomized Clinical Trial

IMPORTANCE

Preclinical and clinical studies have suggested a neuroprotective effect of remote ischemic conditioning (RIC), which involves repeated occlusion/release cycles on bilateral upper limb arteries; however, robust evidence in patients with ischemic stroke is lacking.

OBJECTIVE

To assess the efficacy of RIC for acute moderate ischemic stroke.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, open-label, blinded-end point, randomized clinical trial including 1893 patients with acute moderate ischemic stroke was conducted at 55 hospitals in China from December 26, 2018, through January 19, 2021, and the date of final follow-up was April 19, 2021.

INTERVENTIONS

Eligible patients were randomly assigned within 48 hours after symptom onset to receive treatment with RIC (using a pneumatic electronic device and consisting of 5 cycles of cuff inflation for 5 minutes and deflation for 5 minutes to the bilateral upper limbs to 200 mm Hg) for 10 to 14 days as an adjunct to guideline-based treatment (n = 922) or guideline-based treatment alone (n = 971).

MAIN OUTCOMES AND MEASURES

The primary end point was excellent functional outcome at 90 days, defined as a modified Rankin Scale score of 0 to 1. All end points had blinded assessment and were analyzed on a full analysis set.

RESULTS

Among 1893 eligible patients with acute moderate ischemic stroke who were randomized (mean [SD] age, 65 [10.3] years; 606 women [34.1%]), 1776 (93.8%) completed the trial. The number with excellent functional outcome at 90 days was 582 (67.4%) in the RIC group and 566 (62.0%) in the control group (risk difference, 5.4% [95% CI, 1.0%-9.9%]; odds ratio, 1.27 [95% CI, 1.05-1.54]; P = .02). The proportion of patients with any adverse events was 6.8% (59/863) in the RIC group and 5.6% (51/913) in the control group.

CONCLUSIONS AND RELEVANCE

Among adults with acute moderate ischemic stroke, treatment with remote ischemic conditioning compared with usual care significantly increased the likelihood of excellent neurologic function at 90 days. However, these findings require replication in another trial before concluding efficacy for this intervention.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03740971.

Axillary Anatomy and Pathology: Pearls and "Pitfalls" for Thoracic Imagers

The axilla contains several important structures which exist in a relatively confined anatomic space between the neck, chest wall, and upper extremity. While neoplastic lymphadenopathy may be among the most common axillary conditions, many other processes may be encountered. For example, expanded use of axillary vessels for access routes for endovascular procedures will increase the need for radiologists to access vessel anatomy, patency, and complications that may arise. Knowledge of axillary anatomy and pathology will allow the imager to systematically evaluate the axillae using various imaging modalities.

Use of a Steerable Sheath for Completely Femoral Access in Branched Endovascular Aortic Repair Compared to Upper Extremity Access

PURPOSE

To compare bridging stent graft (BSG) implantation in downward oriented branches in branched endovascular aortic repair (bEVAR), using a commercially available steerable sheath from an exclusively femoral access (TFA) with traditional upper extremity access (UEA).

METHODS

In a retrospective cohort study, 7 patients with 19 branches in the TFA cohort received BSG insertion using the Medtronic Heli FX steerable sheath from a femoral access, and 10 patients with 32 branches in the UEA cohort from a brachial approach. Technical success, total intervention time, fluoroscopy time, branch cannulation time, and complication rate were recorded.

RESULTS

Technical success was 19/19 branches in the TFA and 31/32 in the UEA cohort. The mean branch cannulation time was considerably shorter in the TFA group (17 vs. 29 min, p = 0.003), and total intervention time tended to be shorter (169 vs. 217 min, p = 0.176).

CONCLUSION

Using a commercially available steerable sheath allowed successful cannulation of all branches in this cohort and was associated with significantly shorter branch cannulation times. Potentially, this technique can lower the stroke and brachial puncture site complication risk as well as reduce total intervention time and radiation dose.

LEVEL OF EVIDENCE

2b, retrospective cohort study.

One-Year Outcomes of the First Human Trial on Robot-Assisted Lymphaticovenous Anastomosis for Breast Cancer-Related Lymphedema

BACKGROUND

Lymphaticovenous anastomosis, a supermicrosurgical technique, creates bypasses between the lymphatic and venous systems. The quality of lymphaticovenous anastomosis depends on the surgeon's dexterity and precision, and is subject to imperfections caused by the physiologic tremor of the human hand. A dedicated robot for microsurgery has been created to overcome these limitations (MUSA, MicroSure, Eindhoven, The Netherlands). This study describes 1-year clinical outcomes of the first-in-human trial of robot-assisted and manual lymphaticovenous anastomosis in patients with breast cancer-related lymphedema.

METHODS

In this prospective pilot study, women with breast cancer-related lymphedema were randomized into the robot-assisted or manual lymphaticovenous anastomosis group. Outcomes were quality of life, arm circumference, conservative treatment frequency, arm dermal backflow stage, and anastomosis patency.

RESULTS

Twenty women were included, of whom eight underwent robot-assisted lymphaticovenous anastomosis surgery and 12 underwent manual surgery. In both groups, quality of life significantly improved at 12 months (robot-assisted surgery, p = 0.045; manual surgery, p = 0.001). Arm circumference did not decrease (robot-assisted surgery, p = 0.094; manual surgery, p = 0.240). Daily use of compression garments decreased by 61.9 percent (robot-assisted surgery) and 70.2 percent (manual surgery). The frequency of manual lymphatic drainage remained similar compared with baseline. Arm dermal backflow stage was reduced in one patient in the robot-assisted group and in five cases in the manual group. Overall, 76.5 percent of the anastomoses were patent (robot-assisted surgery, 66.6 percent; manual surgery, 81.8 percent).

CONCLUSIONS

After evaluating 1-year follow-up data, this study confirms the feasibility of robot-assisted lymphaticovenous anastomosis surgery. Clinical outcomes were comparable between robot-assisted and manual lymphaticovenous anastomosis. This encourages further research using the new microsurgical robot MUSA for lymphaticovenous anastomosis and other (super)microsurgical procedures.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

The Acute Effects of Prolonged Uninterrupted Sitting on Vascular Function: A Systematic Review and Meta-analysis

OBJECTIVE

This study aimed to determine the dose-response relationship between prolonged sitting and vascular function in healthy individuals and those with metabolic disturbances and to investigate the acute effects, on vascular function, of interventions that target interrupting prolonged sitting.

DESIGN

This is a systematic review with meta-analysis.

DATA SOURCES

Ovid Embase, Ovid Medline, PubMed, and CINAHL were searched from inception to 4 December 2020.

ELIGIBILITY CRITERIA

Randomized crossover trials, quasi-randomized trials, and parallel group trials where vascular function (flow-mediated dilation [FMD]) was assessed before and after an acute period of sedentary behavior was used in this study.

RESULTS

Prolonged sitting resulted in a significant decrease in the standardized mean change (SMC) for lower-limb FMD at the 120-min (SMC = -0.85, 95% confidence interval [CI] = -1.32 to -0.38) and 180-min (SMC = -1.18, 95% CI = -1.69 to -0.66) time points. A similar pattern was observed for lower-limb shear rate. No significant changes were observed for any outcomes in the upper limb. Subgroup analysis indicated that prolonged sitting decreased lower-limb FMD in healthy adults (SMC = -1.33, 95% CI = -1.89 to -0.78) who had higher a priori vascular endothelial function, but not in those with metabolic and vascular dysfunction (SMC = -0.51, 95% CI = -1.18 to 0.15). Interrupting sitting with active interruptions increased the standardized mean difference for FMD, relative to prolonged sitting, but it was not statistically significant (0.13, 95% CI = -0.20 to 0.45).

CONCLUSIONS

Lower-limb vascular function is progressively impaired as a consequence of prolonged sitting, up to 180 min. A similar trend was not observed in upper-limb vascular function. Subgroup analysis indicated that prolonged sitting negatively affects healthy populations, a finding not observed in those with metabolic disturbances. Regularly interrupting sitting with activity may be beneficial for those with metabolic disturbances.

Impact of Previous Tunneled Vascular Catheters and their Location on Upper Limb Arteriovenous Fistula Function

BACKGROUND

Long-term arteriovenous fistula (AVF) survival has been shown to be adversely affected by the presence of previous tunneled vascular catheters (TVC). We analyzed the effect of previous TVCs and their location (ipsilateral versus contralateral) on the successful function of upper-limb AVFs in the first 12 months after creation.

METHODS

We retrospectively reviewed clinical data on patients' first upper-limb AVFs, created between January 2013 and December 2017. We analyzed the rates of successful AVF function (successful cannulation using two needles for ≥50% sessions over a 2-week period) at 6 and 12 months after creation, time to AVF maturation, and rates of assisted maturation.

RESULTS

In total, 287 patients with first AVFs were identified, of which 142 patients had a previous TVC (102 contralateral, 40 ipsilateral) and 145 had no previous TVC. The no TVC group had higher rates of AVF function at both 6 months (69% versus 54%, OR, 1.84; 95% CI, 1.00 to 3.39, P=0.05) and 12 months (84% versus 64%, OR, 3.10; 95% CI, 1.53 to 6.26, P=0.002) compared with the TVC group. The contralateral TVC group had higher rates of AVF function at 6 months (60% versus 40%, OR, 2.21; 95% CI, 1.01 to 4.88, P=0.05), but not at 12 months (66% versus 58%, OR, 1.42; 95% CI, 0.62 to 3.25, P=0.40) compared with the ipsilateral TVC group. The median time to AVF maturation in the contralateral and ipsilateral TVC groups were 121.5 and 146 days respectively (P=0.07). Assisted maturation rates were lower in no TVC group compared with the TVC group (12% versus 28%, P=0.007), but similar between the contralateral and ipsilateral TVC groups (29% versus 26%, P=0.74).

CONCLUSIONS

Previous TVC use was associated with poorer AVF function at 6 and 12 months, with a higher rate of assisted maturation. The presence of an ipsilateral TVC was associated with lower successful AVF use at 6 months, compared with contralateral TVC.

Effect of Radiocephalic Anastomotic Length on the Maturation of Arteriovenous Fistula

BACKGROUND

A radiocephalic arteriovenous fistula (RCAVF) is associated with better long-term patency and fewer complications. However, RCAVF have lower maturation rate for hemodialysis compared with upper AVF or arteriovenous graft. We performed this study to determine the effect of the radiocephalic (RC) anastomotic length on the AVF maturation.

METHODS

We reviewed the patients who underwent RCAVF creation with a side-to-end manner from March 2015 to December 2018. AVF maturation was defined as successful hemodialysis (HD) in at least two consecutive sessions. We compared the possible factors including the RC anastomotic length between the initial HD success group and initial HD failure group.

RESULTS

A total of 114 patients underwent RCAVF creation: 72 males and 42 females (63.2% and 36.8%, respectively). The mean preoperative arteriotomy length of the AVF was 14.1 mm (range 11.0-16.0 mm). Out of 114 patients, initial HD was executed successfully in 83 patients (72.8%). Among the 31 patients with initial HD failure (27.2%) balloon angioplasty was successfully performed in 17 patients, failed in 4 patients, and not performed in 10 patients. The secondary success rate after balloon angioplasty was 87.7%. After factor analysis, pre-emptive AVF (P = 0.01), vein diameter (P < 0.001), and flow rate (P < 0.001) were revealed significant factors for initial HD success, but not RC anastomotic length of AVF (P = 0.55).

CONCLUSION

The length of the radiocephalic anastomosis does not affect the RCAVF maturation rate statistically. However, lengthening of arteriotomy on the radial artery may increase the initial success rate of HD.

Percutaneous Arteriovenous Fistula Creation with the 4 French WavelinQ™ EndoAVF System

BACKGROUND

Percutaneous devices for creation of native arteriovenous fistulae offer an alternative to traditional open surgical techniques. The 4 Fr WavelinQ EndoAVF System was developed as a lower profile alternative to facilitate access through smaller vessels and minimize access site complications; The current report is the original first experience of this device, assessing outcome in 120 patients followed for 6 months.

METHODS

The use of the 4 Fr WavelinQ system in three studies, EASE (32 patients), EASE-2 (24 patients), and the EU post-market clinical follow-up study (64 patients) was aggregated and analyzed. Patients were followed with duplex ultrasound at discharge and follow-up visits at 1, 3, and 6 months. Primary, assisted primary, and secondary patency rates were evaluated as Kaplan-Meier (KM) estimates and standard errors. Time to maturity and time to successful cannulation were defined as the mean ± SD days from the procedure in patients enrolled on dialysis.

RESULTS

Procedural success was achieved in 116 patients (96.7%). Primary, assisted-primary, and secondary 6-month patency rates were 71.9%±4.5%, 80.7%±4.1%, and 87.8%±3.3%, respectively. Time to maturity averaged 41±17 days. Time to successful cannulation averaged 68±51 days. Device-related serious adverse events were reported in 3/120 patients (2.5%) and procedure-related serious adverse events occurred in 7/120 patients (5.8%). Arterial or venous access complications were not reported in any of the patients. Access circuit reinterventions were performed in 23 patients (19.2%), split between those performed for EndoAVF maturation (13/120, 10.8%) and maintenance (11/120. 9.2%).

CONCLUSIONS

Percutaneous creation of native dialysis fistulae with the 4 Fr WavelinQ EndoAVF System is safe and effective, with favorable durability and a low rate of serious complications and reinterventions through 6-month follow-up. Utilization of the 4F device allows for percutaneous fistula creation between the radial artery and radial vein or the ulnar artery and ulnar vein. These findings suggest that the 4 Fr device is a useful percutaneous alternative to open surgical AVF or endovascular AVF with larger-bore devices.

Anterolateral thigh free flaps with T-shaped pedicles and multiple venous anastomosis for extremity reconstruction

The anterolateral thigh free flap is one of the most preferred options for reconstructing soft tissues of the extremities and vascular anastomosis is one of the most important factors for flaps survival. T-anastomosis and double venous anastomosis have been widely used for increasing flap survival. This report shows both application of T-shape pedicle and multiple venous anastomosis to each 43 cases for extremity reconstruction that have not been described so far in the literature and it showed the necessity of multiple anastomosis. The locations of the lesions were 8 upper extremities (4 hands, 3 forearms, and 1 upper arm) and 35 lower extremities (5 forefeet, 6 dorsal feet, 4 plantar feet, 11 ankles, and 9 lower legs). We applied T-shaped arterial pedicle to limited anatomical area that had 2 or more major arterial communication sites to overcome the obstruction by reverse flow from communication vessels when 1 of the 2 anastomosis was obstructed. We classified multiple venous anastomosis according to flow direction and the vascular connections between the superficial and deep veins. In result, 37 cases survived completely but 2 flaps developed severe necrosis (>50%) because of infection and hematoma and 4 flaps developed partial necrosis due to wound infection. In conclusion, T-shaped pedicle and multiple venous anastomosis is a method to improve free flap survival and useful in cases where sacrificing a dominant vessel is inevitable or those in which only 1 vessel remains.

Surgical treatment of carpal tunnel syndrome in advanced-stage upper extremity lymphedema: A case report

RATIONALE

Despite significant advances in microsurgical techniques, simultaneous release of transverse carpal ligament (TCL) and lymphovenous anastomosis (LVA) surgeries may be effective for treatment of carpal tunnel syndrome (CTS) and advanced-stage lymphedema. This case report describes the successful treatment of lymphedema with LVA in a patient with CTS and advanced-stage lymphedema.

PATIENT CONCERNS

A 60-year-old female patient was referred to our lymphedema clinic with a 12-year history of chronic, acquired, right upper extremity lymphedema and CTS following right mastectomy and axillary lymph node dissection and adjuvant chemoradiotherapy for treating breast cancer.

DIAGNOSIS

According to the indocyanine green lymphography, magnetic resonance lymphangiography, and electromyography, the patient was diagnosed with CTS and advanced-stage lymphedema (International Society of Lymphology late stage 2).

INTERVENTION

Release of the TCL was performed first, followed by LVA at the wrist, forearm, and antecubital area. The right arm was compressed and elevated immediately postoperatively and postoperative compression bandage therapy with 35 to 40 mm Hg pressure was instituted following surgery.

OUTCOMES

After 2 simultaneous surgeries, the patient had significant circumference and volume reduction of the right hand. The CTS and lymphedema symptoms have decreased following synchronous TCL release and LVA surgeries.

LESSONS

Simultaneous LVA and release of the TCL may be effective and safe in patients with advanced lymphedema and CTS.

Predictive factors of venous recanalization in upper-extremity vein thrombosis

BACKGROUND

Upper extremity venous thrombosis (UEVT) represents about 10% of venous thrombo-embolic disease. This is mainly explained by the increasing use of central venous line, for oncologic or nutritional care. The factors associated with venous recanalization are not known.

OBJECTIVE

The aim of this study was to investigate prognosis factor associated with venous recanalization after UEVT.

METHODS

This study included patients with UEVT diagnosed with duplex ultra-sonography (DUS) from January 2015 to December 2017 with DUS evaluations during follow-up. A multivariate Cox proportional-hazards-model analysis was performed to identify predictive factors of UEVT complete recanalization.

RESULTS

This study included 494 UEVT, 304 proximal UEVT and 190 distal UEVT. The median age was 58 years, 39.5% were women. Clinical context was: hematological malignancy (40.7%), solid cancer (14.2%), infectious or inflammatory context (49.9%) and presence of venous catheters or pacemaker leads in 86.4%. The rate of recanalization without sequelae of UEVT was 38%. For all UEVT, in multivariate analysis, factors associated with complete vein recanalization were: thrombosis associated with central venous catheter (CVC) (HR:2.40, [1.45;3.95], p<0.001), UEVT limited to a venous segment (HR:1.94, [1.26;3.00], p = 0.003), occlusive thrombosis (HR:0.48 [0.34;0.67], p<0.0001), the presence of a PICC Line (HR:2.29, [1.48;3.52], p<0.001), a thrombosis of deep and distal topography (HR:1.70, [1.10;2.63], p = 0.02) or superficial thrombosis of the forearm (HR:2.79, [1.52;5.12], p<0.001). For deep and proximal UEVT, non-occlusive UEVT (HR:2.23, [1.49;3.33], p<0.0001), thrombosis associated with CVC (HR:1.58, [1.01;2.47], p = 0.04) and infectious or inflammatory context (HR:1.63, [1.10;2.41], p = 0.01) were factors associated with complete vein recanalization.

CONCLUSION

In this study, factors associated with UEVT recanalization were UEVT limited to a venous segment, thrombosis associated with CVC, a thrombosis of deep and distal thrombosis topography and superficial thrombosis of the forearm. Occlusive thrombosis was associated with the absence of UEVT recanalization.

Recurrence of Upper Extremity Deep Vein Thrombosis Secondary to COVID-19

Infection with SARS-CoV-2 leading to COVID-19 induces hyperinflammatory and hypercoagulable states, resulting in arterial and venous thromboembolic events. Deep vein thrombosis (DVT) has been well reported in COVID-19 patients. While most DVTs occur in a lower extremity, involvement of the upper extremity is uncommon. In this report, we describe the first reported patient with an upper extremity DVT recurrence secondary to COVID-19 infection.

The Effects of Acute Exposure to Prolonged Sitting, With and Without Interruption, on Vascular Function Among Adults: A Meta-analysis

BACKGROUND

Exposure to acute prolonged sitting can result in vascular dysfunction, particularly within the legs. This vascular dysfunction, assessed using flow-mediated dilation (FMD), is likely the consequence of decreased blood flow-induced shear stress. With mixed success, several sitting interruption strategies have been trialled to preserve vascular function.

OBJECTIVES

The objectives of this meta-analysis were to (1) assess the effects of acute prolonged sitting exposure on vascular function in the upper- and lower-limb arteries, and (2) evaluate the effectiveness of sitting interruption strategies in preserving vascular function. Sub-group analyses were conducted to determine whether artery location or interruption modality explain heterogeneity.

DATA SOURCES

Electronic databases (PubMed, Web of Science, SPORTDiscus, and Google Scholar) were searched from inception to January 2020. Reference lists of eligible studies and relevant reviews were also checked.

STUDY SELECTION

Inclusion criteria for objective (1) were: (i) FMD% was assessed pre- and post-sitting; (ii) studies were either randomised-controlled, randomised-crossover, or quasi-experimental trials; (iii) the sitting period was ≥ 1 h; and (iv) participants were healthy non-smoking adults (≥ 18 years), and free of vascular-acting medication and disease at the time of testing. Additional inclusion criteria for objective (2) were: (i) the interruption strategy must have been during the sitting period; (ii) there was a control (uninterrupted sitting) group/arm; and (iii) the interruption strategy must have involved the participants actively moving their lower- or upper-limbs.

APPRAISAL AND SYNTHESIS METHODS

One thousand eight hundred and two articles were identified, of which 17 (22 trials, n = 269) met inclusion criteria for objective (1). Of those 17 articles, 6 studies (9 trials, n = 127) met the inclusion criteria for objective (2). Weighted mean differences (WMD), 95% confidence intervals (95% CI), and standardised mean difference (SMD) were calculated for all trials using random-effects meta-analysis modelling. SMD was used to determine the magnitude of effect, where < 0.2, 0.2, 0.5, and 0.8 was defined as trivial, small, moderate, and large respectively.

RESULTS

(1) Random-effects modelling showed uninterrupted bouts of prolonged sitting resulted in a significant decrease in FMD% (WMD = - 2.12%, 95% CI - 2.66 to - 1.59, SMD = 0.84). Subgroup analysis revealed reductions in lower- but not upper-limb FMD%. (2) Random-effects modelling showed that interrupting bouts of sitting resulted in a significantly higher FMD% compared to uninterrupted sitting (WMD = 1.91%, 95% CI 0.40 to 3.42, SMD = 0.57). Subgroup analyses failed to identify an optimum interruption strategy but revealed moderate non-significant effects for aerobic interventions (WMD = 2.17%, 95% CI - 0.34 to 4.67, SMD = 0.69) and simple resistance activities (WMD = 2.40%, 95% CI - 0.08 to 4.88, SMD = 0.55) and a trivial effect for standing interruptions (WMD = 0.24%, 95% CI - 0.90 to 1.38, SMD = 0.16).

CONCLUSIONS

Exposure to acute prolonged sitting leads to significant vascular dysfunction in arteries of the lower, but not upper, limbs. The limited available data indicate that vascular dysfunction can be prevented by regularly interrupting sitting, particularly with aerobic or simple resistance activities.

Long Term Results of Bypass Graft to the Right Atrium in the Management of Superior Vena Cava Syndrome in Dialysis Patients

BACKGROUND

Superior vena cava (SVC) occlusion in dialysis patients is a serious complication that can cause SVC syndrome and vascular access dysfunction. While endovascular therapy has advanced to become the first line of treatment, open surgical treatment may still be needed occasionally. However, no long term outcome data has been previously reported.

METHODS

We performed a retrospective review of 5 dialysis patients treated with bypass graft to the right atrium from 2012 to 2014. Four patients had severe dysfunction of their upper arm dialysis access as well as superior vena cava syndrome, and one patient with a femoral tunneled dialysis catheter (TDC) had SVC occlusion. None of the patients were candidates for lower extremity access creation or peritoneal dialysis (PD). Three patients underwent a left brachiocephalic-right atrial bypass and 2 underwent a bypass from the cephalic fistula to the right atrium.

RESULTS

All procedures were technically successful and maintained function of the arteriovenous fistulas or allowed creation of a new upper extremity dialysis graft. One-year secondary patency rate of the bypass was 100%. Longer follow up revealed that one patient died of leg sepsis and another one of a stroke within 14 months after the procedure. Another patient did well for 16 months when recurrent graft thrombosis occurred; and ultimately the graft failed after 31 months despite multiple interventions. Two patients maintained bypass graft patency during a follow up of 78 months; however, they underwent multiple endovascular interventions (23) and open vascular access procedures (4) to maintain hemodialysis function.

CONCLUSION

Bypass grafts to the right atrium in dialysis patients with SVC occlusion are successful in maintaining function of already existing vascular access or new ones. Long term secondary patency can be achieved but requires strict follow up and a proactive endovascular strategy to treat lesions in the access and or the bypass graft.

Patency and functionality of radiocephalic arteriovenous fistulas with an external support device (VasQ™): Real-world single-center experience

BACKGROUND

The VasQTM device was designed to improve the outcome of arteriovenous fistulae by optimizing the hemodynamics of the flow in the juxta-anastomotic region of the arteriovenous fistulae through tailored external support. The aim of the study was to evaluate the impact of the VasQ on outcome of radiocephalic arteriovenous fistulae in a real-world setting.

METHODS

This was a single-center, retrospective analysis of patients with either fistula creation before or after dialysis initiation with implantation of the VasQ device during creation of end-to-side radiocephalic arteriovenous fistulae between June 2018 and May 2019. The flow rate and vein diameter were evaluated intraoperatively, at discharge within 48 h postprocedure and at a follow-up of 1, 3, 6, 9, and 12 months.

RESULTS

Thirty-three VasQ devices were implanted during 33 radiocephalic arteriovenous fistula procedures. The study population comprised mostly of men, with an average age of 66 years. Mean intraoperative flow was 428 mL/min (range: 130-945). All patients were discharged with patent arteriovenous fistulae and mean fistula flow of 740 mL/min (range: 230-1300 mL/min). The primary patency was 100% and 79% at 3 and 6 months, respectively. Cumulative/secondary patency was 100% and 90% at 3 and 6 months, respectively.

CONCLUSION

Data presented here suggest that the VasQ device has the potential to provide benefit to the functionality of radiocephalic arteriovenous fistulae.

Evaluating Tourniquet Efficacy Comparing Exsanguination Techniques for the Upper Extremity

Tourniquets have been used in the medical setting for centuries and have become the gold standard when preparing patients for surgery, particularly in orthopaedic surgery. Upper extremity tourniquet use improves intraoperative visibility and identification of anatomy. It also decreases blood loss intraoperatively and improves the safety of orthopaedic procedures. Despite the widespread use of tourniquets and differing methods of limb exsanguination, little research has been done quantifying its efficacy. The purpose of this study was to compare gravity exsanguination to Esmarch exsanguination of the upper extremity prior to tourniquet inflation in a large patient sample. A plethysmographic method based on water displacement served as a surrogate for the blood volume exsanguinated. Control measurements of water displacement were obtained from both upper extremities without tourniquet inflation. Water displacement was then measured with both gravity and Esmarch exsanguination techniques. Gender, handedness, height, weight, body mass index, and age were recorded for volunteers and used as covariates. Change in mean water displacement from control (un-exsanguinated) arm and gravity alone measurement was 37.2 ml. Change in mean water displacement between control arm and mean Esmarch measurement was 56.3 ml. Exsanguination using Esmarch compared to gravity alone resulted in a 51.2% increase in blood removal. Only age had a significant interaction effect for the Esmarch method. Analysis revealed that age accounted for 21.4% of all variance in blood exsanguinated using the Esmarch method when compared to the control group. The Esmarch technique was more efficacious for all demographics measured, but most efficacious in subjects who were older than 40 years. This data reaffirms that gravity exsanguination is more efficacious than no tourniquet use at all, and that the Esmarch technique is more efficacious than gravity. To our knowledge, this study is the most robust of its kind to critically and objectively compare upper extremity exsanguination methods and overall tourniquet use by age and supports the common practice of Esmarch exsanguination in orthopaedic extremity surgery.

Comparative Study of Hemodialysis in Arteriovenous Fistulas in Low Versus High Blood Flow Rate

BACKGROUND AND OBJECTIVE

Arteriovenous Fistula (AVF) is an essential requirement in Hemodialysis (HD) to remove toxins and excess fluid from the blood of patients with Chronic Renal Failure (CRF). The Blood Flow Rate (BFR) in AVF is an important factor in the success of HD. Due to a lack of studies of low BFR during HD, this study was conducted. The objective of this study was to compare the success rate of HD in patients with a BFR = 400-500 mL min-1 (group-2), in comparison to those of higher BFR (group-1).

MATERIALS AND METHODS

This prospective cohort study was conducted at the ultrasound Doppler (USD) unit in King Fahad Hospital in Almadinah from July to December, 2019. In this study, 44 patients underwent AVF for HD and were assessed by USD for 2 consecutive visits at 3 months intervals. The success rate of HD was measured in patients with a BFR = 400-500 mL min-1 and in those with BFR>500 mL min-1. A comparison of the success rate in the 2 groups was done.

RESULTS

Among the 44 patients, 59% were males and 41% were females. The age of participants ranged from 20-80 years (mean: 46.75±13.67 years). The patients underwent HD 3 or 2 session's week-1 for 3 or 4 hrs (mean 3.84±0.36 h) per session. In the first assessment, the success rate was 100% in both groups but it was 88.24% in group-1 and 70% in group-2 in the second assessment.

CONCLUSION

The success rate of hemodialysis in patients with BFR 400-500 mL min-1 in AVF was acceptable in comparison to that in patients with BFR>500 mL min-1.

Prevalence of abnormal upper limb arterial anatomy and its correlation with access failure during transradial coronary angiography

OBJECTIVE

The study aimed at to find out prevalence of abnormal upper limb arterial anatomy and its correlation with access failure during transradial coronary angiography.

METHOD

This was a prospective observational study of 1512 patients who had undergone transradial coronary angiography (CAG). Angiographic assessment of upper limb arterial tree was performed when the angiographic guidewire or the diagnostic catheter followed an abnormal path or got stuck in its course.

RESULTS

About 5.29% patients (80/1512) were noted to have abnormal upper limb arterial anatomy. The most common abnormality detected were radio-ulnar loop in 22 (1.46%) patients, tortuous upper limb arteries 19 (1.25%) and abnormal high origin of radial artery 10 (0.66%) patients. Access failure was encountered in 4.4% (67/1512) of total patients and 64.17% (43/67) access failure was due to abnormal upper limb arterial anatomy.

CONCLUSION

Abnormal upper limb arterial anatomy was the most common cause of access failure in transradial coronary angiography in this study.

Diffuse Venous Malformations of the Upper Extremity (Bockenheimer Disease): Diagnosis and Management

BACKGROUND

Diffuse venous malformations that involve all tissues in the upper limb and ipsilateral chest wall are known as "phlebectasia of Bockenheimer." The authors describe their experience with management of this uncommon vascular anomaly.

METHODS

The authors' Vascular Anomalies Center registry comprised 18,766 patients over a 40-year period. This review identified 2036 patients with venous malformations of the extremities (10.8 percent), of whom only 80 (0.43 percent) had Bockenheimer disease. The authors retrospectively analyzed patient characteristics, diagnostics, treatments, and complications.

RESULTS

The venous malformation was first noted at birth or within the first few years of life with slow and gradual progression. Pain was related to engorgement of the limb. Thromboses and phleboliths were common, but diffuse intravascular coagulopathy occurred in only 12 patients (15 percent). Skeletal involvement was demonstrated as lytic lesions, cortical scalloping, osteopenia, and pathologic fractures. Management included compression garments (100 percent), sclerotherapy (27.5 percent), and resection of symptomatic areas in 35 percent of patients. Adjunctive pharmacologic medication was given in 7.5 percent. Following resection, 17 patients (60 percent) had one or more complications: hematoma, wound dehiscence, flap loss, contracture, and psychosis. There were no deaths. Symptoms improved in all patients with useful functional outcomes.

CONCLUSIONS

The decision to pursue compression, sclerotherapy, pharmacologic treatment, or resection alone or in combination was made by an interdisciplinary team. Although extensive venous malformations cannot be completely ablated, debulking of symptomatic regions, resection of neuromas, and noninvasive treatments improve the quality of life. Despite the bulk and weight of the arm, forearm, and hand, and the ominous appearance on magnetic resonance imaging, these patients remain functional.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Arteriovenous Access superficialization: A New Technique and Review of Options

BACKGROUND

Up to 30% of autogenous cephalic vein arteriovenous fistulas (AVFs) are too deep for reliable cannulation. Techniques to superficialize these AVFs have been described previously. This study describes a new surgical technique for AVF superficialization and provides a review of the alternative techniques.

METHODS

The path of the fistula is marked using ultrasound, and transverse incisions are made along this path. The underlying tissue is separated from the dermis over this area to expose the fistula outflow vein. The mobilized vein is then elevated and "trapped" directly under the dermis by closing the superficial fascia and adipose tissue beneath it.

RESULTS

Between March 2016 and February 2019, 23 patients underwent superficialization using this technique at two centers. The mean time between AVF creation and superficialization was 6.3 months, and the time to first use for hemodialysis after superficialization was 38.8 ± 27.9 days. The average presuperficialization depth was 7.1 ± 2.4 mm and average postsuperficialization depth was 3.7 ± 2.7 mm (P = 0.002). Sixteen fistulas were successfully accessed for a cannulation rate of 89%. 94.7% of fistulas remained patent at last visit, with only one thrombosed 8-10 weeks after superficialization.

CONCLUSIONS

This technique appears to be both safe and effective, and results in a vein that is immediately subdermal without major contour deformity. Early outcomes are comparable to those alternative methods described in the literature.

Distal revascularization and interval ligation for dialysis access-related ischemia is best performed using arm vein conduit

OBJECTIVE

Distal revascularization and interval ligation (DRIL) is an effective approach to the management of hemodialysis access-related ischemia that offers both symptom relief and access salvage. The great saphenous vein (GSV) has been the most commonly used conduit. However, the use of an ipsilateral arm vein will allow for performance of the operation with the patient under regional anesthesia and might result in lower harvest site morbidity than the GSV. We sought to determine the suitability of DRIL using an arm vein compared with a GSV conduit.

METHODS

All patients who had undergone DRIL from 2008 to 2019 were retrospectively identified in the electronic medical records. The characteristics and outcomes of those with an arm vein vs a GSV conduit were compared using the Wilcoxon log-rank and χ² tests. Access patency was examined using Kaplan-Meier methods, with censoring at lost to follow-up or death.

RESULTS

A total of 66 patients who had undergone DRIL for hand ischemia were included in the present study. An arm vein conduit was used in 40 patients (median age, 65 years; 25% male) and a GSV conduit in 26 patients (median age, 58 years; 19% male). No significant differences in comorbidities were found between the two groups, with the exception of diabetes mellitus (arm vein group, 78%; GSV group, 50% GSV; P = .02). No difference in the ischemia stage at presentation was present between the groups, with most patients presenting with stage 3 ischemia. Also, no differences in patency of hemodialysis access after DRIL between the two groups were found (P = .96). At 12 and 24 months after DRIL, 86.9% (95% confidence interval [CI], 68.3%-94.9%) and 82.0% (95% CI, 61.3%-92.3%) of patients with an arm vein conduit had access patency compared with 93.8% (95% CI, 63.2%-99.1%) and 76.9% (95% CI, 43.0%-92.2%) of those with a GSV conduit, respectively. All but one patient had symptom resolution. The incidence of wound complications was significantly greater in the GSV group than in the arm vein group (46% vs 11%; P = .003). DRIL bypass had remained patent in all but one patient in each group, with a median follow-up of 18 months (range, 1-112 months) in the arm vein conduit group and 15 months (range, 0.25-105 months) in the GSV conduit group.

CONCLUSIONS

DRIL procedures using an arm vein have advantages over those performed with the GSV. In our series, symptom resolution and access salvage were similar but distinctly fewer wound complications had occurred in the arm vein group. Additionally, the use of an arm vein conduit avoids the need for general anesthesia. If an ipsilateral arm vein is available, it should be the conduit of choice when performing DRIL.

Drug-Coated Balloons for Dysfunctional Dialysis Arteriovenous Fistulas

BACKGROUND

Standard percutaneous transluminal angioplasty is the current recommended treatment for dysfunctional hemodialysis fistulas, yet long-term outcomes of this treatment are poor. Drug-coated balloons delivering the antirestenotic agent paclitaxel may improve outcomes.

METHODS

In this prospective, single-blinded, 1:1 randomized trial, we enrolled 330 participants at 29 international sites. Patients with new or restenotic lesions in native upper-extremity arteriovenous fistulas were eligible for participation. After successful high-pressure percutaneous transluminal angioplasty, participants were randomly assigned to receive treatment with a drug-coated balloon or a standard balloon. The primary effectiveness end point was target-lesion primary patency, defined as freedom from clinically driven target-lesion revascularization or access-circuit thrombosis during the 6 months after the index procedure. The primary safety end point, serious adverse events involving the arteriovenous access circuit within 30 days, was assessed in a noninferiority analysis (margin of noninferiority, 7.5 percentage points). The primary analyses included all participants with available end-point data. Additional sensitivity analyses were performed to assess the effect of missing data.

RESULTS

A total of 330 participants underwent randomization; 170 were assigned to receive treatment with a drug-coated balloon, and 160 were assigned to receive treatment with a standard balloon. During the 6 months after the index procedure, target-lesion primary patency was maintained more often in participants who had been treated with a drug-coated balloon than in those who had been treated with a standard balloon (82.2% [125 of 152] vs. 59.5% [88 of 148]; difference in risk, 22.8 percentage points; 95% confidence interval [CI], 12.8 to 32.8; P<0.001). Drug-coated balloons were noninferior to standard balloons with respect to the primary safety end point (4.2% [7 of 166] and 4.4% [7 of 158], respectively; difference in risk, -0.2 percentage points; 95% CI, -5.5 to 5.0; P = 0.002 for noninferiority). Sensitivity analyses confirmed the results of the primary analyses.

CONCLUSIONS

Drug-coated balloon angioplasty was superior to standard angioplasty for the treatment of stenotic lesions in dysfunctional hemodialysis arteriovenous fistulas during the 6 months after the procedure and was noninferior with respect to access circuit-related serious adverse events within 30 days. (Funded by Medtronic; IN.PACT AV Access Study ClinicalTrials.gov number, NCT03041467.).

Preoperative color Doppler ultrasound parameters for surgical decision-making in upper arm arteriovenous fistula maturation

OBJECTIVE

Current scientific evidence is insufficient to determine the best vascular access for each patient. It is an unmet clinical need because vascular access dysfunction accounts for 20% to 30% of hospital admissions. Our aim was to evaluate preoperative color flow Doppler ultrasound (CDUS)-derived parameters (vein diameter and brachial artery flow and diameter) and their effect interaction with comorbidities as predictors of brachiocephalic (BC) and brachiobasilic (BB) arteriovenous fistula (AVF) maturation.

METHODS

A prospective analysis was performed of patients who underwent BC and BB AVF as primary definitive vascular access between January 2016 and May 2017. Variables included patients' demographics, comorbidities, medication, preoperative blood pressure, and CDUS-derived parameters. Outcomes were patency 48 hours after surgery and fistula maturation at 6 and 12 weeks. Nonparametric descriptive and univariate statistics were used. Logistic regression models and receiver operating characteristic curve analyses were performed.

RESULTS

There were 132 patients (91 with BC AVF and 41 with BB AVF) included. The 48-hour patency was 91.7%. AVF maturation at 6 weeks was observed in 71.3%, and AVF maturation at 12 weeks was observed in 66.3%. There were no associations in univariate and multivariate logistic regression analysis between AVF maturation and comorbidities. Systolic blood pressure was an independent predictor of 48-hour patency with an optimized cutoff of 154 mm Hg (area under the curve, 0.73; P = .013; Youden index, 0.40). Vein diameter with tourniquet was an independent predictor of AVF maturation at 6 and 12 weeks with an optimized cutoff of 3.9 mm (area under the curve, 0.74; P < .001; Youden index, 0.38).

CONCLUSIONS

AVF maturation was independent of comorbidities. Systolic blood pressure ≥154 mm Hg and vein diameter with tourniquet ≥3.9 mm were the associated conditions that better predicted BC and BB AVF maturation. There were no effect interactions between CDUS-derived parameters and associated comorbidities.

"Inflammatory Bowel Disease-Not Just the Bowel's Bane": Peripheral Arterial and Venous Thrombosis in a Patient With Crohn Disease

INTRODUCTION

Inflammatory bowel disease (IBD) is a chronic multisystem inflammatory condition with associated endothelial dysfunction and dysregulated coagulation. Although deep venous thrombosis (DVT) in IBD has been well described, arterial thrombosis and thromboembolism are less commonly appreciated.

METHODS

A 63-year-old male with a known history of Crohn disease presented with acute-onset right arm pain. His past vascular history was significant for left lower extremity DVT with an existing inferior vena cava filter and acute ischemia of the right lower extremity requiring a below-knee amputation a year ago. Imaging revealed acute brachial, ulnar, and radial artery thrombosis.

RESULTS

Patient underwent an open right brachial, radial, and ulnar thrombectomy to restore vascular flow. He required multiple exploration and thrombectomy for reocclusion of the vessels in the early postoperative period. He later developed a rapidly deteriorating clinical status, flank ecchymosis and swelling concerning for soft tissue ischemia, and compartment syndrome heralding an eventual hemodynamic collapse. On exploration, he was found to have chronic fibrosis of his left femoral vein and femoral artery occlusion. Clinically, the patient deteriorated rapidly, which resulted in his demise.

CONCLUSION

The inflammatory reaction in IBD leads to arterial stiffening and hypercoagulability, which should theoretically increase the risk for vascular disease. Although the link between IBD and DVT is well established, arterial thrombosis and thromboembolism remain widely debated, with some implications for therapeutic intervention. The link between vascular thrombosis and IBD must be examined further, as the treatment and prevention of vascular complications in IBD depends on our understanding of this relationship.

Association between interarm blood pressure differences and diabetic retinopathy in patients with type 2 diabetes

BACKGROUND

The effect of interarm blood pressure difference on the development of diabetic retinopathy, proteinuria and chronic kidney disease remains unknown. We investigated to determine the impact of interarm blood pressure difference on the prevalence of diabetic retinopathy, proteinuria and chronic kidney disease in patients with type 2 diabetes.

METHODS

The study included 563 patients with diabetes, who were evaluated with a simultaneous bilateral blood pressure measurement. The cutoff values for interarm blood pressure difference were 5, 10 and 15 mmHg. Logistic regression analysis was used to explore the relation between interarm blood pressure difference and diabetic retinopathy, proteinuria and chronic kidney disease.

RESULTS

Diabetic patients with systolic interarm blood pressure difference ⩾5, ⩾10 and ⩾15 mmHg showed an increased risk of diabetic retinopathy [adjusted odds ratio = 1.48 (95% confidence interval = 1.01-2.18), odds ratio = 1.80 (95% confidence interval = 0.99-3.22), odds ratio = 2.29 (95% confidence interval = 1.00-5.23)] after adjustment. There were significant associations between interarm blood pressure difference ⩾5 and ⩾10 mmHg and proteinuria [odds ratio = 1.68 (95% confidence interval = 1.15-2.44), 1.89 (95% confidence interval = 1.05-3.37)].

CONCLUSION

The association between interarm blood pressure difference and the presence of diabetic retinopathy emerged even for systolic interarm blood pressure difference ⩾5 mmHg without interaction of systolic blood pressure. Systolic interarm blood pressure difference should be considered a surrogate marker for vascular complication in patients with type 2 diabetes.

Intravenous drug use history is not associated with poorer outcomes after arteriovenous access creation

OBJECTIVE

Rising intravenous drug use (IVDU) paralleled with an increasing dialysis-dependent end-stage renal disease population may pose a challenge for creating and maintaining arteriovenous (AV) access for hemodialysis. We aimed to elucidate baseline characteristics and outcomes of AV access creation in the IVDU population.

METHODS

The Vascular Quality Initiative (2011-2018) was queried for patients undergoing AV access placement. Univariable and multivariable analyses comparing outcomes of patients with and without IVDU history were performed.

RESULTS

Of 33,404 patients undergoing AV access creation, 601 (1.8%) had IVDU history (21.8% current and 78.2% past users). IVDU patients receiving AV access were more often younger, male, nonwhite, smokers, homeless, Medicaid recipients, and hospitalized at the time of surgery (P < .001 for all). They exhibited higher rates of congestive heart failure, chronic obstructive pulmonary disease, and human immunodeficiency virus/acquired immunodeficiency syndrome (P < .05 for all). They more frequently had tunneled catheters at the time of access creation (53.6% vs 42%; P < .001) and had a previous AV access (25.3% vs 21.7%; P = .002). IVDU patients more often received prosthetic AV grafts (28.6% vs 18%; P < .001) and more often had anastomoses created to basilic veins (33.1% vs 23.2%; P < .001) but less often to cephalic veins (36.8% vs 57.7%; P < .001). IVDU patients had longer postoperative length of stay (2 ± 6 days vs 0.9 ± 5 days; P < .001) but no significant difference in 30-day mortality (1.7% vs 1.2%; P = .3). Comparing IVDU vs no IVDU cohorts, 1-year access infection-free survival (85.4% vs 86.6%; P = .382), primary patency loss-free survival (39.5% vs 37.9%; P = .335), endovascular/open reintervention-free survival (58% vs 57%; P = .705), and overall survival (89.7% vs 88.9%; P = .635) were similar. On multivariable analysis, IVDU was independently associated with postoperative length of stay (odds ratio, 1.64; 95% confidence interval, 1.35-2; P < .001) but not with 30-day mortality or 1-year infection-free survival, primary patency loss-free survival, reintervention-free survival, and all-cause mortality. The null results were confirmed in a propensity score-matched cohort.

CONCLUSIONS

IVDU history was uncommon among patients undergoing AV access creation at Vascular Quality Initiative centers and was not independently associated with major morbidity or mortality postoperatively. IVDU patients more often received grafts or autogenous access with anastomoses to basilic veins. Although these patients frequently have more comorbidities, IVDU should not deter AV access creation.

Higher body mass index is associated with reinterventions and lower maturation rates after upper extremity arteriovenous access creation

OBJECTIVE

A patient's body mass index (BMI) can affect both perioperative and postoperative outcomes across all surgical specialties. Given that obesity and end-stage renal disease are growing in prevalence, we aimed to evaluate the association between BMI and outcomes of upper extremity arteriovenous (AV) access creation.

METHODS

A retrospective single-institution review was conducted for AV access creations from 2014 to 2018. Patient demographics, comorbidities, and AV access details were recorded. BMI groups were defined as normal weight (18.5-24.9 kg/m²), overweight (25-29.9 kg/m²), obese (30-39.9 kg/m²), and morbidly obese (>40 kg/m²). Perioperative complications and long-term outcomes including access maturation (defined as access being used for hemodialysis or the surgeon's judgment that access was ready for use in patients not yet on hemodialysis), occlusion, and reintervention were evaluated.

RESULTS

A total of 611 upper extremity AV access creations were performed on patients who were normal weight (29.6%), overweight (31.3%), obese (29.6%), and morbidly obese (9.5%). Access type included brachiocephalic (43.2%), brachiobasilic (25.5%), and radiocephalic (14.2%) fistulas and AV grafts (14.2%). Median age was 60.9 years, and 59.6% were male. Univariable analysis showed no difference between BMI groups for perioperative steal, hematoma, home discharge, or 30-day primary patency. Freedom from reintervention at 2 years on Kaplan-Meier analysis differed by BMI (44.5% ± 4.6% normal weight, 29% ± 3.8% overweight, 39.8% ± 4.3% obese, 34.7% ± 8% morbidly obese; P = .041). There was no difference in 2-year freedom from new access creation or survival. AV access maturity within 180 days differed between BMI groups (74.3% normal weight, 66% overweight, 65.7% obese, 46.6% morbidly obese; P < .001). On multivariable analysis, failure to mature within 180 days was associated with overweight (odds ratio [OR], 1.93; 95% confidence interval [CI], 1.14-3.29; P = .002), obese (OR, 2.12; 95% CI, 1.19-3.47; P = .009), and morbidly obese (OR, 3.68; 95% CI, 1.85-7.3; P < .001) relative to normal weight BMI. AV access reintervention was associated with overweight (hazard ratio [HR], 1.83; 95% CI, 1.34-2.5), obese (HR, 1.56; 95% CI, 1.12-2.16), and morbidly obese (HR, 1.69; 95% CI, 1.1-2.58; P = .02) relative to normal weight BMI. BMI was not independently associated with long-term readmission or survival.

CONCLUSIONS

Obesity is associated with higher rates of AV access failure to mature and reintervention. Surgeons performing access creation on obese patients must consider this for planning and setting expectations. Weight loss assistance may need to be incorporated into treatment algorithms.

Single-stage basilic vein transposition-An effective and viable autogenous access for dialysis

INTRODUCTION

The National Kidney Foundation's/Kidney Disease Outcomes Quality Initiative recommends autogenous arteriovenous fistulas as the preferred method for long-term hemodialysis access. Basilic vein transposition is not only an alternative in patients with failed arteriovenous access but also can be the first option for arteriovenous access in patients with inadequate cephalic vein. Several studies have shown better patency rates, cost-effectiveness, and fewer complications of autogenous access over prosthetic arteriovenous grafts.

AIMS AND OBJECTIVES

To analyze patency, complication rates, and outcomes of single-stage basilic vein transposition.

MATERIALS AND METHODS

A single-center retrospective non-randomized study conducted at Ramaiah Medical College and Hospitals, Bangalore from July 2015 to June 2018. A total of 94 consented patients who underwent single-stage basilic vein transposition were included in the study. All the surgeries were done in a single stage under regional anesthesia. All the complications and patency rates were calculated at the end of one year. Statistical analysis was performed using the Chi-square test, and patency rates were assessed using the Kaplan-Meir survival curve.

RESULTS

A total of 94 single-stage basilic vein transposition was performed. Fifty-four patients had a previous failed autogenous access and 40 had either absent or thrombosed cephalic vein. The mean age was 56.6 years with 59.57% males. The mean basilic vein and brachial artery diameter was 3.6 and 3.8 mm, respectively. The primary patency rate at one year was 84%. Edema and thrombosis were the most common complication in our study.

CONCLUSION

Single-stage basilic vein transposition is a feasible surgical option in end-stage renal disease patients and provides durable autogenous access with very reasonable outcomes in terms of complication rates and patency rates.

Severe Acute Respiratory Syndrome Coronavirus 2 Infection and the Upper Limb Deep Vein Thrombosis Risk

Little or nothing is known about the correlation between the upper limb deep vein thrombosis (UL-DVT) and severe acute respiratory syndrome coronavirus 2 (SARS–CoV-2). We describe the increased risk of UL-DVT in 3 patients with SARS–CoV-2 who require continuous positive airway pressure with a hood and the need for early adequate antithrombotic prophylaxis.

Correlation of Central with Jugular and Upper-limb Venous Pressure Measurements

BACKGROUND

Correlation data of different external reference points and methods used to measure venous pressures are scarce in the literature. We correlated central venous pressure with jugular venous pressure measured from sternal angle and with jugular and upper-limb venous pressures from zero level corresponding to mid-right-atrium level.

METHODS

A hospital-based observational study in the medical and surgical intensive care units was conducted for period of one year. Central venous pressure was measured from right fourth intercostal space in mid-axillary line and jugular venous pressure from sternal angle and jugular and upper-limb venous pressures from horizontal plane through the midpoint of anteroposterior line from anterior end of right fourth intercostal space to back. We measured central venous pressure by central venous cannulation and jugular and upper-limb venous pressures clinically by JVP Meter®. Upper-limb venous pressure was indicated by collapse of visible veins in dorsum of hands as the arm was slowly raised from dependent position.

RESULTS

Correlation coefficient (r) values were 0.61 between central venous pressure and jugular venous pressure from zero level, 0.48 between central venous pressure and jugular venous pressure from sternal angle, and 0.31 between central and upper-limb venous pressures; and 0.67 and 0.50 between central venous pressure measured from right internal jugular vein and jugular venous pressure from zero level and sternal angle respectively and 0.52 and 0.44 between central venous pressure from right sub-clavian vein and jugular venous pressure from zero level and sternal angle respectively.

CONCLUSIONS

Different correlation values indicate the need to have future investigations and consensus on the common external reference point and methods to measure venous pressures.

Super Wide-Field Photoacoustic Microscopy of Animals and Humans In Vivo

Acoustic-resolution photoacoustic micro-scopy (AR-PAM) is an emerging biomedical imaging modality that combines superior optical sensitivity and fine ultrasonic resolution in an optical quasi-diffusive regime (~1-3 mm in tissues). AR-PAM has been explored for anatomical, functional, and molecular information in biological tissues. Heretofore, AR-PAM systems have suffered from a limited field-of-view (FOV) and/or slow imaging speed, which have precluded them from routine preclinical and clinical applications. Here, we demonstrate an advanced AR-PAM system that overcomes both limitations of previous AR-PAM systems. The new AR-PAM system demonstrates a super wide-field scanning that utilized a 1-axis water-proofing microelectromechanical systems (MEMS) scanner integrated with two linear stepper motor stages. We achieved an extended FOV of 36 ×80 mm² by mosaicking multiple volumetric images of 36 ×2.5 mm² with a total acquisition time of 224 seconds. For one volumetric data (i.e., 36 ×2.5 mm²), the B-scan imaging speed over the short axis (i.e., 2.5 mm) was 83 Hz in humans. The 3D volumetric image was also provided by using MEMS mirror scanning along the X-axis and stepper-motor scanning along the Y-axis. The super-wide FOV mosaic image was realized by registering and merging all individual volumetric images. Finally, we obtained multi-plane whole-body in-vivo PA images of small animals, illustrating distinct multi-layered structures including microvascular networks and internal organs. Importantly, we also visualized microvascular networks in human fingers, palm, and forearm successfully. This advanced MEMS-AR-PAM system could potentially enable hitherto not possible wide preclinical and clinical applications.

Vascularization of the arteriovenous fistula wall and association with maturation outcomes

BACKGROUND AND OBJECTIVES

The venous vasa vasorum is the mesh of microvessels that provide oxygen and nutrients to the walls of large veins. Whether changes to the vasa vasorum have any effects on human arteriovenous fistula outcomes remains undetermined. In this study, we challenged the hypothesis that inadequate vascularization of the arteriovenous fistula wall is associated with maturation failure.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

This case-control pilot study includes pre-access veins and arteriovenous fistula venous samples (i.e. tissue pairs) from 30 patients undergoing two-stage arteriovenous fistula creation (15 matured and 15 failed to mature). Using anti-CD31 immunohistochemistry, we quantified vasa vasorum density and luminal area (vasa vasorum area) in the intima, media, and adventitia of pre-access veins and fistulas. We evaluated the association of pre-existing and postoperative arteriovenous fistula vascularization with maturation failure and with postoperative morphometry.

RESULTS

Vascularization of veins and arteriovenous fistulas was predominantly observed in the outer media and adventitia. Only the size of the microvasculature (vasa vasorum area), but not the number of vessels (vasa vasorum density), increased after arteriovenous fistula creation in the adventitia (median vasa vasorum area 1366 µm2/mm2 (interquartile range 495-2582) in veins versus 3077 µm2/mm2 (1812-5323) in arteriovenous fistulas, p < 0.001), while no changes were observed in the intima and media. Postoperative intimal thickness correlated with lower vascularization of the media (r 0.53, p = 0.003 for vasa vasorum density and r 0.37, p = 0.045 for vasa vasorum area). However, there were no significant differences in pre-existing, postoperative, or longitudinal change in vascularization between arteriovenous fistulas with distinct maturation outcomes.

CONCLUSION

The lack of change in intimal and medial vascularization after arteriovenous fistula creation argues against higher oxygen demand in the inner walls of the fistula during the vein to arteriovenous fistula transformation. Postoperative intimal hyperplasia in the arteriovenous fistula wall appears to thrive under hypoxic conditions. Vasa vasorum density and area by themselves are not predictive of maturation outcomes.