Rejoining Veins for Forced Maturation of Small-Caliber Arteriovenous Fistula

BACKGROUND

To evaluate the efficacy of rejoining mainstream and accessory veins for forced maturation of autogenous arteriovenous fistula (AVF).

METHODS

Twenty-three patients who underwent forced maturation through vein rejoining between January 2018 and September 2022 were included. In cases where AVF maturation failure due to the presence of accessory veins, rejoining was primarily considered when distinguishing the main branch becomes challenging. This difficulty typically occurs when the sizes of the 2 vessels are nearly equal and the combined diameters of these veins exceed 6 mm.

RESULTS

The mean age and follow-up duration were 57.39 ± 16.22 years and 965.65 ± 573.42 days, respectively. Rejoining of both arterial and venous cannulation sites was performed in 11 patients (47.8%), and rejoining of only the venous cannulation site or only the arterial cannulation site was performed in 11 patients (47.8%) and 1 patient (4.3%), respectively. The mean vein size was 0.35 ± 0.06 cm before rejoining and 0.69 ± 0.07 cm after surgery, indicating a significant increase in size (P < 0.01), whereas the flow did not change significantly following rejoining surgery. Maturation and cannulation success was 100%. The 1-year primary patency rate after surgery was 82.0%. During the follow-up period, 34.8% of the patients required additional percutaneous transluminal angioplasty to maintain patency, and 2 patients (11.8%) had stenosis in the rejoined section.

CONCLUSIONS

Rejoining surgery is an effective method for achieving AVF maturation in patients with accessory veins when identification of the mainstream vein is difficult, and this method may be considered when achieving maturation by sacrificing 1 vein is expected to be challenging.

The effect of short-term remote ischemic preconditioning on endothelial function of patients with chronic kidney disease: A randomized pilot study

AIM

Patients with chronic kidney disease (CKD) are more susceptible to endothelial dysfunction and cardiovascular disease (CV). Remote ischemic preconditioning (rIPC) has been proven efficient in improving endothelial function and lowering the risk of CV. However, the safety and effect of rIPC on endothelial function in patients with CKD have not been effectively assessed.

METHODS

45 patients with CKD (average estimated glomerular filtration rate: 48.4 mL/min/1.73 m2) were randomly allocated to either 7-day daily upper-arm rIPC (4 × 5 min 200 mmHg, interspaced by 5-min reperfusion) or control (4 × 5 min 60 mmHg, interspaced by 5-min reperfusion). Vascular endothelial function was assessed by natural log-transformed reactive hyperemia index (LnRHI) before and after a 7-day intervention. Arterial elasticity was assessed by augmentation index (AI).

RESULTS

The results showed that LnRHI could be improved by rIPC treatment (Pre = 0.57 ± 0.04 vs. Post = 0.67 ± 0.04, p = .001) with no changes relative to control (Pre = 0.68 ± 0.06 vs. Post = 0.64 ± 0.05, p = .470). Compared with the control group, the improvement of LnRHI was greater after rIPC treatment (rIPC vs. Control: 0.10 ± 0.03 vs. -0.04 ± 0.06, between-group mean difference, -0.15 [95% CI, -0.27 to -0.02], p = .027), while there was no significant difference in the change of AI@75 bpm (p = .312) between the two groups.

CONCLUSION

RIPC is safe and well tolerated in patients with CKD. This pilot study suggests that rIPC seems to have the potential therapeutic effect to improve endothelial function. Of note, further larger trials are still warranted to confirm the efficacy of rIPC in improving endothelial function in CKD patients.

Autologous Alternative Vein Grafts for Infrainguinal Bypass in the Absence of Single-Segment Great Saphenous Vein: A Single-Center Study

BACKGROUND

Alternative autologous veins can be used as a conduit when adequate great saphenous vein is unavailable. We analyzed the results of our infrainguinal bypasses after adopting upper extremity veins in our practice.

METHODS

This is a single-center observational study involving all patients whose infrainguinal bypass involved the use of upper extremity veins between April 2019, when we began using arm veins, and February 2023.

RESULTS

During the study period, 49 bypasses were done in 48 patients; mean age 68.1 ± 9.8; men 32 (66.7%); body mass index 28.0 ± 4.8; indications for surgery: chronic limb threatening ischemia 41 (83.7%); acute limb ischemia 3 (6.1%); complications of previous prosthetic 3 (6.1%), or autologous 2 (4.1%) bypass grafts. Vein splicing was used in 43 (87.8%) bypasses with 3-segment grafts being the most common (26; 53.1%). There were 24 (49.0%) femorotibial, 11 (22.4%) femoropopliteal, 9 (18.4%) femoropedal, and 5 (10.2%) extension jump bypass procedures. Eighteen (36.7%) operations were redo surgeries. Twenty-one (42.9%) bypasses were formed using only arm veins. The median follow-up was 12.9 months (4.5-24.2). Two bypasses occluded during the first 30 postoperative days (2/49; 4.1%). Overall 30-day, 1-year, and 2-year primary patency rates were 93.7% ± 3.5%, 84.8% ± 5.9%, and 80.6% ± 6.9%, and secondary patency (SP) rates were 95.8% ± 2.9%, 89.2% ± 5.3%, and 89.2% ± 5.3%. One-segment grafts had better patencies than 2-, 3-, and 4-segment grafts (1-year SP 100% ± 0% vs 87.6% ± 6.0%). Two-year amputation-free survival was 86.8% ± 6.5%; 2-year overall survival was 88.2% ± 6.6%.

CONCLUSIONS

Integration of arm vein grafts in infrainguinal bypass practice can be done safely with low incidences of perioperative graft failure. One-segment grafts had better patencies than spliced vein grafts. The achieved early patency and amputation-free survival rates strongly encourage their use. In the absence of a single-segment great saphenous vein, upper extremity vein grafts should be the preferred conduit choice.

Two-Year Cumulative and Functional Patency after Creation of Endovascular Arteriovenous Hemodialysis Fistulae

PURPOSE

To assess 2-year cumulative and functional patency of endovascular arteriovenous fistulae (endoAVF) created with the WavelinQ device.

MATERIALS AND METHODS

Patients who had fistulae created at a single center from December 2019 to December 2020 were included in this retrospective study. Forty-three patients underwent endoAVF creation (22 females, 21 males). Data collected included patient demographics, location of fistula creation, interventions performed, and brachial artery flow before and after creation. Two-year cumulative and functional patency rates were assessed with Kaplan-Meier method, and variables that affected patency and maturation were examined using Cox proportional hazards model.

RESULTS

Technical success was 95% (41/43), and in 4 patients, the fistula did not mature for dialysis use (9.7%). For the remaining 37 patients with endoAVF maturation, 25 had ulnar-ulnar fistulae, 10 had radial-radial fistulae, and 2 had interosseous artery-vein fistulae. Mean maturity time was 73 days, and brachial artery flow of >886 mL/min was predictive of maturation. Mean tunneled dialysis catheter removal time was 133 days. Number of interventions per patient-year was 0.38, where 8 were maturation procedures (5 vein elevations/transpositions and 3 coil embolizations) and 21 were maintenance angioplasties. Two-year cumulative/secondary and functional patency rates were 89.4% and 92.1%, respectively, with a mean follow-up of 665.7 days. Examined variables did not impact cumulative or functional patency. One adverse event was migration of coil to the heart, which was successfully retrieved at time of procedure.

CONCLUSIONS

Two-year patency of 89.4% and functional patency of 92.1% were observed after endoAVF creation with WavelinQ device.

Long-term outcomes of autologous vein bypass for repair of upper and lower extremity major arterial trauma

OBJECTIVE

Autologous vein is the preferred bypass conduit for extremity arterial injuries owing to superior patency and low infection risk; however, long-term data on outcomes in civilians are limited. Our goal was to assess short- and long-term outcomes of autologous vein bypass for upper and lower extremity arterial trauma.

METHODS

A retrospective review was performed of patients with major extremity arterial injuries (2001-2019) at a level I trauma center. Demographics, injury and intervention details, and outcomes were recorded. Primary outcomes were primary patency at 1 year and 3 years. Secondary outcomes were limb function at 6 months, major amputation, and mortality. Multivariable analysis determined risk factors for functional impairment.

RESULTS

There were 107 extremity arterial injuries (31.8% upper and 68.2% lower) treated with autologous vein bypass. Mechanism was penetrating in 77% of cases, of which 79.3% were due to firearms. The most frequently injured vessels were the common and superficial femoral (38%), popliteal (30%), and brachial arteries (29%). For upper extremity trauma, concomitant nerve and orthopedic injuries were found in 15 (44.1%) and 11 (32.4%) cases, respectively. For lower extremities, concomitant nerve injuries were found in 10 (13.7%) cases, and orthopedic injuries in 31 (42.5%). Great saphenous vein was the conduit in 96% of cases. Immediate intraoperative bypass revision occurred in 9.3% of patients, most commonly for graft thrombosis. The in-hospital return to operating room rate was 15.9%, with graft thrombosis (47.1%) and wound infections (23.5%) being the most common reasons. The median follow-up was 3.6 years. Kaplan-Meier analysis showed 92% primary patency at 1 year and 90% at 3 years. At 6 months, 36.1% of patients had functional impairment. Of patients with functional impairment at 6 months, 62.9% had concomitant nerve and 60% concomitant orthopedic injuries. Of those with nerve injury, 91.7% had functional impairment, compared with 17.8% without nerve injury (P < .001). Of patients with orthopedic injuries, 51.2% had functional impairment, vs 25% of those without orthopedic injuries (P = .01). On multivariable analysis, concomitant nerve injury (odds ratio, 127.4; 95% confidence interval, 17-957; P <. 001) and immediate intraoperative revision (odds ratio, 11.03; 95% confidence interval, 1.27-95.55; P = .029) were associated with functional impairment.

CONCLUSIONS

Autologous vein bypass for major extremity arterial trauma is durable; however, many patients have long-term limb dysfunction associated with concomitant nerve injury and immediate intraoperative bypass revision. These factors may allow clinicians to identify patients at higher risk for functional impairment, to outline patient expectations and direct rehabilitation efforts toward improving functional outcomes.

Large thrombus in non-atherosclerotic thoracic ascending aorta as the source of acute upper limb ischemia in a young cocaine user

OBJECTIVES

We present the case of a young woman cocaine user without other cardiovascular risk factors attended to the emergency service presenting signs of acute arterial ischemia on the right arm.

METHODS

An angio-CT of the upper limb was performed, highlighting the occlusion of the radial and ulnar arteries and in addition revealed a floating thrombus in the posterior wall of the aortic arch.

RESULTS

The patient underwent urgent surgery with transhumeral thrombectomy and four days later, she underwent surgery to remove the aortic thrombus.

CONCLUSIONS

A floating thrombus in a non-atherosclerotic ascending aorta conditioning peripheral embolism with upper limbs ischemia is a very rare entity that has to be evaluated finding and treating the origin of the pathology.

Temporal trends in hemodialysis access creation during the fistula first era

OBJECTIVE

Although forearm arteriovenous fistulas (AVFs) are the preferred initial vascular access for hemodialysis based on national guidelines, there are no population-level studies evaluating trends in creation of forearm vs upper arm AVFs and arteriovenous grafts (AVGs). The purpose of this study was to report temporal trends in first-time permanent hemodialysis access type, and to assess the effect of national initiatives on rates of AVF placement.

METHODS

Retrospective cross-sectional study (2012-2022) utilizing the Vascular Quality Initiative database. All patients older than 18 years with creation of first-time upper extremity surgical hemodialysis access were included. Anatomic location of the AVF or AVG (forearm vs upper arm) was defined based on inflow artery, outflow vein, and presumed cannulation zone. Primary analysis examined temporal trends in rates of forearm vs upper arm AVFs and AVGs using time series analyses (modified Mann-Kendall test). Subgroup analyses examined rates of access configuration stratified by age, sex, race, dialysis, and socioeconomic status. Interrupted time series analysis was performed to assess the effect of the 2015 Fistula First Catheter Last initiative on rates of AVFs.

RESULTS

Of the 52,170 accesses, 57.9% were upper arm AVFs, 25.2% were forearm AVFs, 15.4% were upper arm AVGs, and 1.5% were forearm AVGs. From 2012 to 2022, there was no significant change in overall rates of forearm or upper arm AVFs. There was a numerical increase in upper arm AVGs (13.9 to 18.2 per 100; P = .09), whereas forearm AVGs significantly declined (1.8 to 0.7 per 100; P = .02). In subgroup analyses, we observed a decrease in forearm AVFs among men (33.1 to 28.7 per 100; P = .04) and disadvantaged (Area Deprivation Index percentile ≥50) patients (29.0 to 20.7 per 100; P = .04), whereas female (17.2 to 23.1 per 100; P = .03), Black (15.6 to 24.5 per 100; P < .01), elderly (age ≥80 years) (18.7 to 32.5 per 100; P < .01), and disadvantaged (13.6 to 20.5 per 100; P < .01) patients had a significant increase in upper arm AVGs. The Fistula First Catheter Last initiative had no effect on the rate of AVF placement (83.2 to 83.7 per 100; P=.37).

CONCLUSIONS

Despite national initiatives to promote autogenous vascular access, the rates of first-time AVFs have remained relatively constant, with forearm AVFs only representing one-quarter of all permanent surgical accesses. Furthermore, elderly, Black, female, and disadvantaged patients saw an increase in upper arm AVGs. Further efforts to elucidate factors associated with forearm AVF placement, as well as potential physician, center, and regional variation is warranted.

Chest-to-arm tunneling technique for central venous access devices in neonates

BACKGROUND

Chest-to-arm (CTA) tunneling technique has been described recently as an alternative option to exit site of the catheter in the infraclavicular area.

METHOD

We report our experience with ultrasound-guided centrally inserted central catheters (CICCs) placed using CTA tunneling in six neonates. All central venous catheters were positioned with ultrasound guidance and real-time tip location.

RESULTS

There were no insertion-related complications; all devices were correctly positioned at the first attempt. During the follow-up, we found no catheter-related thrombosis, infections, or catheter malfunction. No tip position-related complications. Only one case of secondary malposition was reported.

CONCLUSION

In our experience, the CTA tunneling technique is reliable, safe, and feasible in the neonate even from the first hours of life, as well as for preterm newborns; it could be a valid alternative to the usual exit site.

Hemodialysis vascular access flow measurements by the novel DMed NephroFlow® device: A comparative study with Transonic®

INTRODUCTION

The current Spanish Clinical Guidelines on Vascular Access for Hemodialysis support the need for surveillance and monitoring of vascular access (VA) to avoid complications. Ultrasound dilution (UD) methods are accepted for the evaluation of VA flow and Transonic® has established the gold standard method for the measurement. The DMed NephroFlow (NIPRO®) device, based on UD method has recently been incorporated. We report a comparative study between the classic Transonic® versus the new NephroFlow® device.

MATERIAL AND METHODS

For two consecutive months, measurements of VA flow using both referred systems were performed in patients with a native arteriovenous fistula (AVF) or a graft (AVG) on hemodialysis (HD) in our unit. Both studies were undertaken according to the usual recommendations: VA flow of 250 ml/min, ultrafiltration rate without modifications, both needles in the same vein, and always in the first hour of the HD session.

RESULTS

Forty-five patients were included: 17 women and 28 men, mean age of 67 ± 12 years. Thirty patients were diabetic. The baseline meantime on HD was 51 ± 39 months (range: 3-163). Type of VA was: 17 patients radio-cephalic AVF, 17 brachiocephalic AVF, 7 brachiobasilic AVF, and 3 with a graft. The mean flow estimated by the Transonic® was 1222 ± 805 ml/min and the estimated flow by the NephroFlow® device was 1252 ± 975 ml/min. Good reliability between Transonic® and NephroFlow® was observed, with a reliability index of Cronbach's Alpha of 0.927 and an Intraclass Correlation Index of 0.928.

CONCLUSIONS

The NephroFlow® device seems comparable with the accepted gold standard UD method for estimating VA flow. More studies must be performed to verify these results. However, they should be considered for the surveillance and monitoring of VA flow, in agreement with the Spanish Guidelines.

Long term outcomes of 'Christmas Tree' banding for haemodialysis access induced distal ischemia: A 13-year experience

BACKGROUND

The reduction in distal arterial flow following arteriovenous fistula (AVF) creation can cause a perfusion deficit known as haemodialysis access induced distal ischemia (HAIDI). Various techniques have been advocated to treat this difficult problem with varying success. We present the long-term outcomes following a novel banding technique.

METHODS

46 patients in this cohort from 2008 to 2021 underwent a novel banding procedure using a Dacron™ patch shaped with one slit-end and saw-tooth edges (resulting in a 'Christmas-tree' pattern) to provide a ratchet mechanism to progressively constrict the fistula outflow. Real-time finger perfusion pressure monitoring allowed an accurate reduction in AVF flow whilst increasing distal arterial perfusion pressure. Baseline characteristic were recorded and Kaplan-Meier survival curves were obtained to calculate the post-intervention primary, assisted primary and secondary patency.

RESULTS

29 patients presented with rest pain and 11 presented with tissue loss due to distal ischemia. The post-intervention primary access patency was 100%, 98%, 78% and 61% at 30, 60 and 180 days and 1 year respectively. Complete resolution of symptoms was achieved in 74% (n = 34) of patients and a partial response needing no further intervention was achieved in 11% (n = 5) of patients. A Youden index calculation suggested that digital pressures of 41 mm Hg or lower in an open AVF were highly sensitive for symptomatic hand ischemia whereas pressures greater than 65 mm Hg ruled out distal ischemia.

CONCLUSION

'Christmas-tree' banding with on table finger systolic pressures is not only an efficacious and durable method for treating HAIDI but also preserves fistula patency.

The 2-by-2 Inch "Key Window" in the Upper Extremity: An Anatomical Appraisal of the Accessibility and Proximity of the Major Nerves and Vessels

BACKGROUND

The brachial plexus is a network of nerves located between the neck and axilla, which receives input from C5-T1. Distally, the nerves and blood vessels that supply the arm and forearm form a medial neurovascular bundle. The purpose of this study was to illustrate that a peripheral nerve dissection via a 2 × 2 inch window would allow for identification and isolation of the major nerves and blood vessels that supply the arm and forearm.

METHODS

A right side formalin-fixed latex-injected cadaveric arm was transected at the proximal part of the axillary fold and included the scapular attachments. Step-by-step anatomical dissection was carried out and documented with three-dimensional digital imaging.

RESULTS

A 2 × 2 inch window centered 2 inches distal to the axillary fold on the medial surface of the arm enabled access to the major neurovascular structures of the arm and forearm: the median nerve, ulnar nerve, medial antebrachial cutaneous nerve, radial nerve and triceps motor branches, musculocutaneous nerve and its biceps and brachialis branches and lateral antebrachial cutaneous nerve, basilic vein and brachial artery and vein, and profunda brachii artery.

CONCLUSIONS

Our study demonstrates that the majority of the neurovascular supply in the arm and forearm can be accessed through a 2 × 2 inch area in the medial arm. Although this "key window" may not be entirely utilized in the operative setting, our comprehensive didactic description of peripheral nerve dissection in the cadaver laboratory can help in safer identification of complex anatomy encountered during surgical procedures.

The difference in diameter between radial artery and cephalic vein correlates with primary patency of radio-cephalic arteriovenous fistula

INTRODUCTION

Autogenous radio-cephalic arteriovenous fistula (RCAVF) is preferred for chronic hemodialysis access. However, RCAVF still suffers from disappointing survival due to fistula dysfunction, with intimal hyperplasia (IH) as an underlying cause of this condition. The inconsistency of radial artery diameter (DRA) and cephalic vein diameter (DCV) is one of the factors affecting the shear disturbance, which is believed to trigger the onset of IH. However, there are no reports correlating the difference in DRA and DCV with RCAVF outcomes.

METHODS

This was a retrospective cohort study. Consecutive patients (n = 233) with a new RCAVF created were included if they underwent duplex ultrasound examination to evaluate preoperatively the radial artery diameter (DRA) and cephalic venous diameter (DCV). We then calculated radial artery-cephalic vein diameter difference (DCV minus DRA, termed DCV-DRA hereafter) and evaluated the association of the preoperative DCV-DRA with primary patency of RCAVF at 12 months. Subgroup analysis was also performed to explore effect modification by age, gender, radial artery diameter, and cephalic vein diameter with DCV-DRA.

RESULTS

After adjusting for age, gender, weight, and mean arterial pressure, the preoperative DCV-DRA was associated with primary patency of RCAVF at 12 months (adjusted Odds ratio [aOR], 1.524 per 1-mm increase; 95% confidence interval [95% CI], 1.048-2.218). The primary patency of RCAVF at 12 months was achieved in 69.4%, 71.8%,and 87.3% of patients with a preoperative DCV-DRA of ⩽-0.6 mm, (-0.5)-0.5 mm, and ⩾0.6 mm, respectively. P for trend was 0.029. Patients with DCV-DRA of ⩾0.6 mm had a much higher chance of 12-month patency than patients with DCV-DRA of ⩽-0.6 mm (aOR, 3.574; 95% CI, 1.276-10.010). Age, gender, radial artery diameter, and cephalic vein diameter did not modify the association of DCV-DRA with primary patency of RCAVF at 12 months.

CONCLUSIONS

Preoperative DCV-DRA may be an under-recognized predictor of RCAVF patency.

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.

A meta-analysis of vascular access outcomes in hemodialysis patients aged 75 years or older

BACKGROUND

Several existing guidelines advocate the access creation without any specific recommendations for those patients over 75 years of age. The aim of this meta-analysis is to compare the outcomes of different vascular access procedures in the sub-group of elderly ESRD patients ⩾75 years of age.

METHODS

A literature search was performed using the MEDLINE and SCOPUS electronic databases. The analysis focused on studies with subgroups of elderly patients ⩾75 years of age with different vascular access procedures, and compared the failure rates of autologous versus prosthetic vascular access. Articles comparing patency rates of distal (forearm) versus proximal upper arm AVFs were also investigated.

RESULTS

Twelve relevant studies were identified and included in the meta-analysis. The pooled results revealed a statistically significant unassisted (primary) failure rate at 24 months in favor of autologous AVFs [odds ratio (OR): 0.56, 95% CI: 0.38-0.83, p = 0.003]. A secondary analysis revealed significantly higher 12 months unassisted (primary) and secondary failure rates of forearm AVFs compared with proximal upper arm AVFs (OR: 2.14, 95% CI: 1.53-2.97, p < 0.00001 and OR: 1.76, 95% CI: 1.12-2.78, p < 0.01 respectively).

CONCLUSION

An increased risk of failure of prosthetic vascular access procedures was found compared with autologous AVFs in patients ⩾75 years of age. Elderly patients ⩾75 years should not be excluded from creation of an autologous access, with proximal upper arm AVFs having better patency rates.

Percutaneous arteriovenous fistula creation in the management of severe Hemophilia A and end-stage kidney disease needing hemodialysis access, and beyond

With the contemporary KDOQI, a patient-focused approach in vascular access care is emphasized more than ever when planning RRT. Nevertheless, functional vascular access continues to be the Achilles' heel for successful hemodialysis in specific patient sub-groups, such as the Hemophilia-A population. The newer percutaneous endovascular approach is a safer alternative when conventional surgical AVF poses high bleeding risks perioperatively, which subsequently prevents ESKD patients to have desired permanent dialysis access. This article presents the case of a 45-year-old male with severe Hemophilia-A, who has been dialysis-dependent due to diabetic kidney disease and hypertension. Due to the severity of his progressively worsening bleeding disorder, his previous surgeries to treat other comorbidities have been complicated and involved challenging peri-operative treatment courses that include blood and factor VIII infusions, bleeding wounds, along with prolonged hospital stays. With the fear of bleeding diathesis, a conventional surgical AVF was not pursued, which has left him with a prolonged tunneled CVC while not being considered a candidate for peritoneal dialysis. We offered the patient a left arm percutaneous endovascular AVF creation with the WavelinQ™ 4F Endo-AVF system as an alternative option for his permanent hemodialysis access. An Endo-AVF was created bloodlessly between the left radial artery and lateral radial vein percutaneously with only two 4-French accesses at left wrist. The patient has been receiving full sessions of hemodialysis with expected flow rates and free of the CVC since. Likely the first case of such utilization reported, the utilization of percutaneous Endo-AVF for this patient has suggested not only that the endovascularly created AVF offers a good alternative dialysis access for hemophilia A patient populations, but also due to this technology's unique features, it can be potentially employed in other situations, such as needs for reliable and chronic venous accesses and blood product exchanges.

Modified no-touch technique for radio-cephalic arteriovenous fistula increases primary patency and decreases juxta-anastomotic stenosis

OBJECTIVE

Low primary patency rate is a major problem of radio-cephalic arteriovenous fistula (RC-AVF) creation. Radial artery deviation and reimplantation (RADAR) is associated with low juxta-anastomotic stenosis rate. However, inflow artery stenosis is prominent with RADAR. To further reduce injury to veins and arteries during operation, a modified no-touch technique (MNTT) was used to create RC-AVF.

METHODS

We retrospectively reviewed our prospectively maintained database of patients with end-stage renal disease (ESRD)s undergoing RC-AVF creation for hemodialysis using either the MNTT between January 2021 and January 2022 (MNTT group) or conventional surgical procedure ( end-to-side vein-to-artery anastomosis) between October 2016 and October 2017 (Control group). Patients who chose to undergo RC-AVF surgery underwent standardized preoperative mapping and postoperative fistula evaluations using duplex ultrasound. Additionally, 4D flow MRI data were used to visualize and quantify the hemodynamics of one RC-AVF by MNTT. Outcomes included primary patency, juxta-anastomotic stenosis, and maturation rates.

RESULTS

Forty patients underwent RC-AVFs by MNTT, compared to 60 patients in the control group. The MNTT group had a higher primary unassisted patency rate than the control group (p = 0.038). Juxta-anastomotic stenosis (all on the cephalic vein) occurred in 4 (10%) patients who underwent MNTT. RC-AVF maturation rates after 3 months were not different between both groups (maturation rate: 90% and 81.7% in the MNTT and control groups, respectively, p = 0.253). COX regression showed that both conventional AVF surgery (p = 0.031) and smaller cephalic vein diameter (p = 0.034) were associated with higher odds of RC-AVF failure. The AVF flow within the proximal vein remained helical during cardiac cycle. The distribution of wall shear stress (WSS) and oscillatory shear index (OSI) differed from that of conventional surgical AVF.

CONCLUSION

RC-AVF by MNTT increases primary patency rate and decreases juxta-anastomotic stenosis rate. The improvement in hemodynamics may be one of the important reasons for the better patency rate of in the RC-AVF by MNTT group.

Association of risk stratification score with dialysis vascular access stenosis

BACKGROUNDS

Clinical monitoring is the recommended standard for identifying dialysis access dysfunction; however, clinical monitoring requires skill and training, which is challenging for understaffed clinics and overburdened healthcare personnel. A vascular access risk stratification score was recently proposed to assist in detecting dialysis access dysfunction.

PURPOSE

Our objective was to evaluate the utility of using vascular access risk scores to assess venous stenosis in hemodialysis vascular accesses.

METHODS

We prospectively enrolled adult patients who were receiving hemodialysis through an arteriovenous access and who had a risk score ⩽3 (low-risk) or ⩾8 (high-risk). We compared the occurrence of access stenosis (>50% on ultrasonography or angiography) between low-risk and high-risk groups and assessed clinical monitoring results for each group.

RESULTS

Of the 38 patients analyzed (18 low-risk; 20 high-risk), 16 (42%) had significant stenosis. Clinical monitoring results were positive in 39% of the low-risk and 60% of the high-risk group (p = 0.19). The high-risk group had significantly higher occurrence of stenosis than the low-risk group (65% vs 17%; p = 0.003). Sensitivity and specificity of a high score for identifying stenosis were 81% and 68%, respectively. The positive predictive value of a high-risk score was 65%, and the negative predictive value was 80%. Only 11 (58%) of 19 subjects with positive clinical monitoring had significant stenosis. In a multivariable model, the high-risk group had seven-fold higher odds of stenosis than the low-risk group (aOR = 7.38; 95% CI, 1.44-37.82; p = 0.02). Positive clinical monitoring results and previous stenotic history were not associated with stenosis. Every unit increase in the score was associated with 34% higher odds of stenosis (aOR = 1.34; 95% CI, 1.05-1.70; p = 0.02).

CONCLUSIONS

A calculated risk score may help predict the development of hemodialysis vascular access stenosis and may provide a simple and reliable objective measure for risk stratification.

Effects of positive airway pressure on basilic vein diameter and venous flow velocity in healthy volunteers

INTRODUCTION

The placement of vascular catheters of adequate size in accordance to catheter-to-vein ratio (CVR) recommendations represents one of the cornerstones of catheter-related upper vein thrombosis prevention. However there is scarcity of data on its effect on the venous dynamics of the basilic vein, a common site for long-term catheter placement. This study investigates the effects of the application of positive airway pressure on the diameter and blood flow velocity of basilic vein. We also measured the effects of under-armpit straps, a device commonly used to keep continuous positive airway pressure (CPAP) helmets in place.

METHODS

We enrolled 28 healthy volunteers. Basilic vein diameter and minimum/maximum blood flow velocity, according to respiratory venous flow oscillation, were measured by ultrasound on the midpoint of their dominant arm during spontaneous breathing and during breathing in a CPAP helmet with 10 cm H2O of airway pressure applied, with the helmet kept in place either through armpit straps or by tying the helmet to the bed.

RESULTS

The application of 10 cm H2O of positive airway pressure significantly increased basilic vein diameter by 0.9 ± 0.2 mm, while reducing minimum blood flow velocity by 1.8 ± 0.4 cm/s. These effects were amplified by the application of under armpit straps.

CONCLUSIONS

Breathing with positive airway pressure increases basilic vein diameter while reducing blood flow-velocity. This phenomenon might lead to an incorrect assessment of CVR, misleading the operator into choosing improperly large catheters.

Straight lateral thigh femoropopliteal-femoral arteriovenous graft an alternative vascular access for patients with exhausted upper limbs dialysis access

INTRODUCTION

The durability of hemodialysis vascular access remains a troublesome issue for the patients as well as vascular surgeons that requires frequent reinterventions to maintain the access function.

AIM

This study aimed to evaluate straight thigh polytetrafluethylene (PTFE) arteriovenous graft (AVG) in patients with exhausted upper extremities dialysis access.

METHOD

Our study was a retrospective analysis of prospectively collected data of 30 patients were operated upon for straight pattern lateral thigh PTFE AVG between 2016 and 2018. The primary outcome was efficacy and patency of AVG, and secondary outcome was procedure safety, including infection, thrombosis, ligation, lower limb functional status, and mortality.

RESULTS

A 30 patients with 30 Lower Limb AVG with maximum 30-month follow-up period. The mean age was 48 years. Males were (n = 15/30). Thrombophilia patients were (n = 7/30). Primary patency at 6 months was 100%. It declined to 93% at 12 months, 73% at 18 months, 47% at 24 months, and 40% at 30 months. The secondary patency was 97% at 18 months, 83% at 24 months, and 73% at 30 months. More than half of the patients showed complications (n = 18/30), the most frequent was thrombosis (n = 16/18). A secondary procedure was needed for 17 patients, the most frequent was thrombectomy (n = 11/17), adjunctive culprit lesion repair was the key for regaining graft patency. Graft removal was necessary in six patients due to infection (n = 4) and ruptured graft aneurysm (n = 2).

CONCLUSION

Lateral straight thigh PTFE AVG is a reliable and durable alternative modality with adequate dialysis efficacy in patients with exhausted upper extremities dialysis accesses. Secondary procedures due to complications were frequent but no significant major bleeding as regard patients with ruptured graft were non-significant and no distal threatening ischemia or related deaths were observed.

Diagnosis and treatment of deep vein thrombosis of the lower and upper limbs. 2024 recommendations of the venous thromboembolism group of the Spanish Society of Internal Medicine

Deep vein thrombosis (DVT) of the limbs is a common disease and causes significant morbidity and mortality. It is frequently the prelude to pulmonary embolism (PE), it can recur in 30% of patients and in 25-40% of cases they can develop post-thrombotic syndrome (PTS), with a significant impact in functional status and quality of life. This document contains the recommendations on the diagnosis and treatment of acute DVT from the Thromboembolic Disease group of the Spanish Society of Internal Medicine (SEMI). PE and thrombosis of unusual venous territories (cerebral, renal, mesenteric, superficial, etc.) are outside its scope, as well as thrombosis associated with catheter and thrombosis associated with cancer, which due to their peculiarities will be the subject of other positioning documents of the Thromboembolic Disease group of the Spanish Society of Internal Medicine (SEMI).

Comparison of percutaneous transluminal angioplasty and surgical revision after intraoperative dilatation with biliary tract probes for arteriovenous fistula stenosis at juxta-anastomosis

BACKGROUND

Percutaneous transluminal angioplasty (PTA) is widely used for stenosis of vascular access (VA) for hemodialysis. We aimed to evaluate the effectiveness of both PTA and surgical revision after intraoperative dilatation with biliary tract probes for juxta-anastomotic stenosis in autogenous radiocephalic arteriovenous fistulas (RCAVFs).

METHODS

We performed a retrospective analysis of PTA and surgical revision after intraoperative dilatation with biliary tract probes; these were the first interventions after RCAVF establishment in 112 patients with juxta-anastomotic stenosis. Anatomical (number of stenoses) and clinical variables (age and gender of the patient, time of hemodialysis, AVF age, presence of diabetes mellitus, and cause of end-stage renal disease) were reviewed. Technical success, clinical success, and post-intervention primary patency were evaluated.

RESULTS

Our study enrolled 35 patients in the PTA group and 77 patients in the surgical revision group. Clinical and technical success rates of both groups were 100%. There were no complications, such as bleeding or hematomas. Using the Kaplan-Meier method, the post-intervention primary patency rates at 3, 6, 9, 12, 18, and 24 months in the PTA group were 100%, 94.28%, 77.1%, 60%, 54.29%, and 45.71%, respectively, and those in the surgical revision group were 100%, 94.81%, 92.2%, 90.91%, 81.82%, and 76.62%, respectively. The post-intervention primary patency rates at 9-24 months in the surgical revision group were significantly higher than those in the PTA group (χ2 = 19.04, p < 0.0001).

CONCLUSION

The post-intervention long-term primary patency rate of surgical revision after intraoperative dilatation with biliary tract probes is higher than that of PTA for the first intervention of patients with juxta-anastomotic stenosis in RCAVFs. The surgical revision method is safe and effective, especially in hospitals that have not yet carried out PTA.

Upper-limb neurovascular compression, pectoralis minor and quadrilateral space syndromes: A narrative review of current literature

Pectoralis minor syndrome (PMS) and quadrilateral space syndrome (QSS) are uncommon neurovascular compression disorders affecting the upper extremity. PMS involves compression under the pectoralis minor muscle, and QSS results from compression in the quadrilateral space-both are classically observed in overhead-motion athletes. Diagnosing PMS and QSS may be challenging due to variable presentations and similarities with other, more common, upper-limb pathologies. Although there is no gold standard diagnostic, local analgesic muscle-block response in a patient with the appropriate clinical context is often all that is required for an accurate diagnosis after excluding more common etiologies. Treatment ranges from conservative physical therapy to decompressive surgery, which is reserved for refractory cases or severe, acute vascular presentations. Decompression generally yields favorable outcomes, with most patients experiencing significant relief and restored baseline function. In conclusion, PMS and QSS, although rare, can cause debilitating upper-extremity symptoms; accurate diagnosis and appropriate treatment offer excellent outcomes, alleviating pain and disability.

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.