Retrospective evaluation of three types of expanded polytetrafluoroethylene grafts for upper limb vascular access.

Currently, three expanded polytetrafluoroethylene (ePTFE) prosthetic graft types are most commonly used for patients with end-stage kidney disease (ESKD) who require long-term vascular access for hemodialysis. However, studies comparing the three ePTFE grafts are limited. This study compared the clinical efficacy and postoperative complications of three ePTFE prosthetic graft types used for upper limb arteriovenous graft (AVG) surgery among patients with ESKD. Patients with ESKD requiring upper limb AVG surgery admitted to our center between January 2016 and September 2019 were enrolled. Overall, 282 patients who completed the 2-year follow-up were included and classified into the following three groups according to the ePTFE graft type: the GPVG group with the PROPATEN® graft, the GAVG group with the straight-type GORE® ACUSEAL, and the BVVG group with the VENAFLO® II. The patency rate and incidence of access-related complications were analyzed and compared between groups. The patients were followed up postoperatively, and data were collected at 6, 12, 18, and 24 months postoperatively. Respective to these follow-up time points, in the GPVG group, the primary patency rates were 74.29%, 65.71%, 51.43%, and 42.86%; the assisted primary patency rates were 85.71%, 74.29%, 60.00%, and 48.57%; and the secondary patency rates were 85.71%, 80.00%, 71.43%, and 60.00%. In the GAVG group, the primary patency rates were 73.03%, 53.93%, 59.42%, and 38.20%; the assisted primary patency rates were 83.15%, 68.54%, 59.55%, and 53.93%; and the secondary patency rates were 85.39%, 77.53%, 68.54%, and 62.92%, respectively. In the BVVG group, the primary patency rates were 67.24%, 53.45%, 41.38%, and 29.31%; the assisted primary patency rates were 84.48%, 67.24%, 55.17%, and 44.83%; and the secondary patency rates were 86.21%, 81.03%, 68.97%, and 60.34%, respectively. The differences in patency rates across the three grafts were not statistically significant. Overall, 18, 4, and 12 patients in the GPVG, GAVG, and BVVG groups, respectively, experienced seroma. Among the three grafts, GORE® ACUSEAL had the shortest anastomosis hemostatic time. The first cannulation times for the three grafts were GPVG at 16 (±8.2), GAVG at 4 (±4.9), and BVVG at 18 (±12.7) days. No significant difference was found in the postoperative swelling rate between the GPVG group and the other two groups. Furthermore, no statistically significant differences were found across the three graft types regarding postoperative vascular access stenosis and thrombosis, ischemic steal syndrome, pseudoaneurysm, or infection. In conclusion, no statistically significant differences in the postoperative primary, assisted primary, or secondary graft patency rates were observed among the three groups. A shorter anastomosis hemostatic time, first cannulation time, and seroma occurrence were observed with the ACUSEAL® graft than with its counterparts. The incidence of upper extremity swelling postoperatively was greater with the PROPATEN® graft than with the other grafts. No statistically significant differences were observed among the three grafts regarding the remaining complications.

Volkmann's ischaemic contracture of the upper extremity - raising a red flag in the setting of developing countries.

INTRODUCTION: Volkmann's ischaemic contracture (VIC) is a disabling condition resulting from tissue necrosis due to impaired vascular supply to the limb. Over the years VIC has become rare in developed countries with many different aetiologies described. It was alarming to have high incidence of established VIC in our practice in Nepal. A detailed analysis was conducted to accurately describe this issue. METHODS: We collected 47 cases of VIC over six years and noted the age, sex, district of origin and cause of VIC, duration of injury to presentation, and the grade of VIC. Then we compared these characteristics of VIC of each Nepal province and created a map to show the problematic regions. RESULTS: Out of 47 patients, 46 could have been prevented by an early treatment. The most common cause was a tight cast in 25 patients (53.19%), followed by unintentionally self-caused VIC by applying tight bandages in 21 patients (44.68%). Most cases came from province 6 (29.78%). Our group included three mild (6.4%), 35 moderate (74.5%) and nine severe (19.1%) cases of VIC. Only 14 cases (29.78%) had a timely fasciotomy in the past. CONCLUSION: VIC is an irreversible complication of the compartment syndrome which is an easily preventable condition in the setting of developing countries. Our focus should, therefore, aim at preventing such disastrous conditions as 97.87% of cases we encountered could have been avoided by proper primary care. In the case of Nepal most cases came from province 6 and province 3.

Comparison of the effects of axillary brachial plexus block, inhalation anesthesia, and total intravenous anesthesia on tourniquet-induced ischemia-reperfusion injury in upper extremity surgery.

BACKGROUND: Post-ischemia reperfusion can lead to oxidative stress and an increase in oxidative markers. Employing preventive strategies and antioxidant agents may help mitigate ischemia-reperfusion injury (IRI). The use of a tourniquet in extremity surgery has been associated with IRI. This study aims to investigate the impact of three different approaches- brachial plexus block, total intravenous anesthesia (TIVA), and inhalation anesthesia-on IRI during upper extremity surgery using a tourniquet. METHODS: Patients aged 18 to 45 with American Society of Anesthesiologists (ASA) I-II scores were randomly assigned to one of three groups: Group A received an axillary block with bupivacaine; Group I underwent inhalation anesthesia with sevoflurane; and Group T received TIVA with propofol and remifentanil infusion. Blood samples were collected to measure glucose, lactate, total anti-oxidant status (TAS), total oxidant status (TOS), and ischemia-modified albumin (IMA) levels at various time points: before anesthesia (t1), 1 minute before tourniquet release (t2), 20 minutes after tourniquet release (t3), and 4 hours after tourniquet release (t4). RESULTS: In Group I, lactate levels at t3, and glucose levels at t2 and t3, were higher compared to the other groups. Group A exhibited lower IMA levels at t2, t3, and t4 than the other groups. Additionally, Group I had lower IMA levels at t2, t3, and t4 compared to Group T. TAS levels were higher in Group I at t2, t3, and t4 compared to the other groups. TOS levels at t2 and t3 were lower in Group A than in Group I. CONCLUSION: Axillary anesthesia results in a sympathetic block, promoting better perfusion of the upper extremity. This study demonstrated lower levels of oxidative stress markers with axillary plexus block. Therefore, these results suggest that the axillary block has the potential to mitigate IRI.

Validating the Accuracy of Omron HEM-1026 (HCR-1901T2/HCR-1902T2): Blood Pressure Monitoring Device at Home, According to the Universal Protocol.

Purpose: The performance of Omron HEM-1026 (HCR-1901T2 / HCR-1902T2) for monitoring blood pressure (BP) in the upper arm was validated in accordance with the International Organization for Standardization (ISO) 81060-2:2018+amendment (Amd)1:2020 protocol. Methods: The device was assessed in 101 participants who fulfilled the inclusion criteria, including arm circumference range and systolic and diastolic BP provided by the protocol. Data validation and analysis were performed according to the manufacturer's instructions. Results: In the ISO 81060-2:2018+Amd 1:2020 validation procedure (criterion 1), the mean ± standard deviation (SD) of the differences between the test device and reference BP was -2.1 ± 7.24/-0.6 ± 5.63 mmHg (systolic/diastolic). These data fulfilled the ISO81060-2:2018+Amd1:2020 requirement of ≤5±≤8 mmHg. The mean differences between the two observers and Omron HEM-1026 were -2.1 ± 5.71 mmHg for systolic BP and -0.6 ± 4.81 mmHg for diastolic BP, fulfilling criterion 2 with an SD of ≤ 6.62 for systolic BP and ≤ 6.91 for diastolic BP. The two ISO criteria were fulfilled. Conclusion: The Omron HEM-1026 BP monitor fulfilled the requirements of the ISO 81060-2:2018+Amd 1:2020 validation standard and can be recommended for home BP measurements in the general population.

Compression syndrome of distal peripheral aneurysms of the upper limb.

True aneurysm of the radial artery is very rare. Aneurysmal expansion of arteries due to degenerative changes, possibly infections, primarily affects the abdominal and thoracic aorta, intra and extracranial sections of cerebral arteries, popliteal artery, and visceral arteries. Published literature does not address the aneurysm on the distal sections of the arteries of upper or lower limb. Unlike the classic symptoms of aneurysmally altered arteries such as rupture, thrombosis and embolization, we encounter more often vascular compression syndrome in distal peripheral aneurysms. We demonstrate the case management of a patient with over 20 years increasing wrist resistance. A fusiform aneurysm of the distal section of the radial artery was identified by sonography. Under general anesthesia, we performed aneurysm resection and artery reconstruction using an interpositum from the ipsilateral cephalic vein. The histological examination of the resected tissue confirmed the presence of all three layers of the vascular wall, confirming the true aneurysm of the radial artery. No complications developed in the patient in the postoperative period and all problems related to the aneurysm subsided (Fig. 4, Ref. 23). Keywords: aneurysm, arteria radialis, surgical reconstruction.

Upper limb computed tomography (CT) angiography in the emergency department.

A range of abnormalities may acutely affect the upper limb (UL) extremity vasculature including trauma, peripheral vascular disease, and inflammatory conditions. Significant technical advances in computed tomography angiography (CTA) have led to the widespread adoption of this noninvasive modality for rapid evaluation of UL arterial abnormalities in the emergency department setting. A key advantage of CTA over traditional digital subtraction angiography (DSA) is the ability to evaluate concurrent osseous and soft tissue injuries. Accurate identification of pathology requires knowledge of normal UL arterial anatomy in addition to a high-quality study, which may be achieved with a robust CTA protocol. We describe the spectrum of imaging findings on upper limb CTA associated with various acute presentations. Traumatic vascular injuries may occur secondary to penetrating and blunt aetiologies appearing on CTA as contrast extravasation, pooling, pseudoaneurysm, occlusion, and arteriovenous fistula. Peripheral vascular disease manifests as atherosclerotic plaques with thready downstream opacification, and these may precipitate acute thromboembolic events. Inflammatory conditions affecting the UL vasculature includes large and small vessel vasculitides characterised by arterial mural thickening. The use of modalities, including ultrasound and magnetic resonance angiography (MRA), should be considered for further characterisation where appropriate.

Femoral vein translocation for complex hemodialysis access.

OBJECTIVE: Vascular access is difficult in patients without suitable arm veins and prior graft infections. The use of femoral vein translocation (FVT) to the upper extremity or contralateral lower extremity for hemodialysis access may be associated with low infection rates and high patency rates. FVT is used for patients without central venous occlusion who have failed prior access either owing to graft infection or repetitive graft thrombosis. The largest case series consists of 30 cases. The objective of this study is to determine the infection incidence, primary patency, primary-assisted patency, and secondary patency rates among FVTs. METHODS: A retrospective chart review was performed on all patients who underwent FVT by a single vascular practice over a 10-year period (2013-2023). Study variables included length to last follow-up (months), prior access, prior graft infection, comorbid conditions, primary patency, primary-assisted patency, secondary patency, postoperative steal syndrome, postoperative graft infection, postoperative harvest site complication, and postoperative lower extremity compartment syndrome. RESULTS: A total of 131 FVTs were performed from 2013 to 2023; 126 patients (47% male, 53% female; 76% Black, 24% White) with a mean age of 52 ± 14 years and a mean body mass index of 29 ± 8 had at least 1 month of follow-up and were included for analysis. The median follow-up was 46 months (interqurtile range, 19-72 months). The mean number of prior permanent accesses was 2.5 ± 1.4. Forty-eight percent of patients had prior graft infections. The primary, primary-assisted, and secondary patency rates were 66%, 93%, and 98%, respectively, at 6 months; 43%, 85%, and 96% at 12 months; 25%, 70%, and 92% at 24 months; 16%, 61%, and 88% at 36 months; and 14%, 56%, and 82% at 48 months. Postoperative steal syndrome and postoperative access infection requiring excision was observed 16% and 5% of patients, respectively. Harvest site complications requiring an additional procedure occurred in 19% of cases. Three patients developed lower extremity compartment syndrome postoperatively, requiring fasciotomy. Six patients developed chronic lower extremity edema after femoral vein harvest. The mean procedure time and hospital length of stay were 197 ± 40 minutes and 3.5 ± 2.8 days, respectively. CONCLUSIONS: FVT is associated with low infection rates and high long-term patency rates. Significant postoperative complications include steal syndrome and harvest site complications. FVT remains a viable option for patients who have failed prior access owing to graft infection or repetitive graft thrombosis.

Outcomes of brachial artery transposition in hemodialysis patients.

OBJECTIVE: In hemodialysis patients with a difficult access extremity who are not suitable for an arteriovenous fistula or arteriovenous graft creation, the concept of cannulating a superficialized artery for arterial outflow in dialysis sessions has been adopted as a tertiary alternative. However, its long-term patency and complications have not been recognized widely. We report our 16-year experience with hemodialysis access creation using the brachial artery transposition (BAT) technique. METHODS: This single-center retrospective study included consecutive patients who underwent BAT for hemodialysis vascular access between June 1, 2006, and December 31, 2022. The patency of the whole access circuit and the transposed brachial artery itself was evaluated independently. RESULTS: In total, 193 surgical procedures were included. The success rate was 93.2%. The mean operative time was 128 minutes. The median interval from access placement to first cannulation was 21 days. The primary patency rates for BAT were 92.3%, 91.3%, 90.3%, 86.1%, and 71.9% at 1, 2, 3, 5, and 10 years, respectively. The secondary patency rates for BAT were 96.3%, 96.3%, 95.0%, 90.1%, and 74.9% at 1, 2, 3, 5, and 10 years, respectively. The primary patency rates for the whole access circuit were 61.4%, 49.2%, 45.8%, and 26.9% at 1, 2, 3, and 5 years, respectively. The secondary patency rates for the whole access circuit were 85.1%, 83.3%, 82.0%, and 68.6% at 1, 2, 3, and 5 years, respectively. The overall patient survival rates were 79.6%, 69.6%, 54.6%, 36.5%, and 13.4% at 1, 2, 3, 5 and 10 years, respectively. The abandonments of BAT were brachial artery thrombosis (n = 6), pseudoaneurysm (n = 2), aneurysmal change (n = 1), and other reasons (n = 1). The abandonments of the whole access circuit were exhaustion of venous return (n = 26), abandonment of BAT (n = 7), and other reasons (n = 2). Complications were exhaustion of venous return (n = 26), aneurysmal change (n = 12), pseudoaneurysm (n = 6), brachial artery thrombosis (n = 7), impaired wound healing (n = 19), lymphorrhea (n = 9), skin infection (n = 5), hematoma on cannulation (n = 3), and reduced peripheral blood flow (n = 2). CONCLUSIONS: The patency of BAT was excellent, and that of the whole access circuit was adequate, with a few complications. BAT is an effective alternative from a long-term perspective for patients who are unsuitable for conventional hemodialysis access creation.

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.

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.

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).

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.

Current outcomes following upper and lower extremity arterial trauma from the National Trauma Data Bank.

OBJECTIVE: The modern treatments of trauma have changed in recent years. We aim to evaluate the factors associated with limb salvage and mortality after extremity arterial trauma, especially with respect to the type of conduit used in revascularization. METHODS: The National Trauma Data Bank was queried to identify patients with upper and lower extremity (UE and LE) arterial injuries between 2016 and 2020. The patients were stratified by the types of arterial repair. The primary outcome was in-hospital mortality. RESULTS: 8780 patients were found with 5054 (58%) UE and 3726 (42%) LE injuries. Eighty-three percent were men, and the mean age was 34 ± 15 years. Penetrating mechanism was the predominant mode of injury in both UEs and LEs (73% and 67%, respectively) with a mean injury severity score of 14 ± 8. For UEs, the majority underwent primary repair (67%, P < .001), whereas the remainder received either a bypass (20%) or interposition graft (12%). However, LEs were more likely to receive a bypass (52%, P < .00001) than primary repair or interposition graft (34% and 14%, respectively). Compared with the extremely low rates of amputation and mortality among UE patients (2% for both), LE injuries were more likely to result in both amputation (10%, P < .001) and death (6%, P < .001). Notably, compared with primary repair, the use of a prosthetic conduit was associated with a 6.7-fold increase in the risk of amputation in UE and a 2.4-fold increase in LE (P < .0001 for both). Synthetic bypasses were associated with a nearly 3-fold increase in return to the operating room (OR) in UE bypasses (P < .05) and a 2.4-fold increase in return to the OR in LE bypasses (P < .0001). CONCLUSIONS: In recent years, most extremity vascular trauma was due to penetrating injury with a substantial burden of morbidity and mortality. However, both limb salvage rates and survival rates have remained high. Overall, LE injuries more often led to amputation and mortality than UE injuries. The most frequently used bypass conduit was vein, which was associated with less risk of unplanned return to the OR and limb loss, corroborating current practice guidelines for extremity arterial trauma.

Association of anesthetic modality and other variables on 1-year functional patency of cephalic-based arteriovenous fistulae.

OBJECTIVE: Some studies suggest that regional anesthesia provides better patency for arteriovenous fistula (AVF) for hemodialysis access as compared to local and general anesthesia. This study evaluates the impact of anesthetic modality on long term fistula function at 12 months. METHODS: A retrospective review of patients undergoing cephalic vein-based hemodialysis access in consecutive cases between 2014 and 2019 was conducted from five safety net hospitals. The primary endpoint was functional patency at 12 months. Subset analysis individually evaluated cephalic-based lower forearm and wrist vs upper arm AVFs. Bivariate and multivariate logistic regression models evaluated the relationship between anesthetic modality and fistula function at 12 months. RESULTS: There were 818 cephalic-based fistulas created during the study period. The overall 12-month functional patency rate was 78.7%, including an 81.3% patency for upper arm AVF and 73.3% for wrist AVF (P = .009). There was no statistically significant difference among patients with functional and nonfunctional AVFs at 12 months with respect to anesthetic modality when comparing regional, local, and general anesthesia (P = .343). Multivariate regression analysis identified that history of AVF/arteriovenous graft (odds ratio [OR], 0.24; P = .007), receiving intraoperative systemic anticoagulation (OR, 2.49; P < .001), and vein diameter (OR, 1.85; P = .039) as independently associated with AVF functional patency at 12 months. CONCLUSIONS: There was no association between anesthetic modality and functional patency of cephalic-based AVFs at 12 months. Further studies are needed to better define which patients may benefit from regional anesthesia.

Management of depth to achieve timely arteriovenous fistula utilization.

OBJECTIVE: Failure to achieve timely arteriovenous fistulae (AVFs) utilization due to excessive depth (>6 mm) remains an ongoing concern for dialysis access. This study evaluates the outcomes of radiocephalic (RCF) and brachiocephalic (BCF) fistula elevation required for access utilization. METHODS: A retrospective review of all patients undergoing first-time autologous access over 10 years was undertaken. RCF and BCF were analyzed, and cases of initial access failure due to depth alone were selected for study. Primary and staged brachio-basilic AVF were excluded. Outcomes of early thrombosis, line placement, maturation (successful progression to hemodialysis [HD), reintervention, and functional dialysis (continuous HD for 3 consecutive months) were examined. RESULTS: From January 2012 to December 2022, 1733 patients (67% female; mean age, 61 ± 14 years) underwent autologous AVF placement. Of these, 298 patients (17%) had depth-related AVF access issues (BCF, 71% and RCF, 29%). Nineteen percent of these AVFs underwent a primary balloon-assisted maturation (BAM), and 2% had side branch coil embolization before consideration for elevation. The average time to intervention for depth was 11 ± 4 weeks after primary creation. During elevation, side branch ligation occurred in 38% of cases, and 15% underwent intraoperative BAM, The pre-elevation depth was 8.2 ± 3.1 mm, and the mean post-elevation depth was 4.7 ± 2.9 mm (P = .002). Early thrombosis (<18 days) occurred in 4% of cases. There was no mortality, and the 30-day major adverse cardiac event rate was 2%, with a 30-day morbidity of 5%, which was driven by wound issues. Six percent of the AVFs underwent follow-up BAM within 3 months. Mean maturation of the AVFs was 74% ± 3% vs 72% ± 3% (P = .58) for the elevation vs no-elevation groups at 24 weeks, respectively. However, there was an increase in tunneled central line placement in pre-emptive fistula patients due to the delay in maturation (elevation, 17% vs no-elevation, 8%; P = .008). There was a mean successful access time of 6 ± 3 weeks after elevation (16 ± 4 weeks after access creation). There was a median of 2.4 secondary interventions per year after elevation compared with a median of 2.7 secondary interventions per year without elevation. Mean access functionality was 68% ± 8% vs 75% ± 8% at 3 years for the elevation vs no-elevation groups, respectively (P = .25). CONCLUSIONS: Elevation of deep BCF and RCF occurs late after placement but can be successfully achieved with low morbidity and satisfactory long-term functionality. It results in an increase in tunneled central line placement in pre-emptive fistula patients. Elevation is a valuable adjunct to AVF maturation and enhances an autologous access policy.

Intraoperative transit time flow measurement predicts maturation of radiocephalic arteriovenous fistulas.

OBJECTIVE: The arteriovenous fistula (AVF) is the first choice for gaining vascular access for hemodialysis. However, 20% to 50% of AVFs fail within 4 months after creation. Although demographic risk factors have been described, there is little evidence on the intraoperative predictors of AVF maturation failure. The aim of this study was to assess the predictive value of intraoperative transit time flow measurements (TTFMs) on AVF maturation failure. METHODS: In this retrospective cohort study, intraoperative blood flow, measured using TTFM, was compared with AVF maturation after 6 weeks in 55 patients. Owing to its significantly higher prevalence and risk of nonmaturation, the radiocephalic AVF (RCAVF) was the main focus of this study. A recommended cutoff point for high vs low intraoperative blood flow was determined for RCAVFs, using a receiver operating characteristic curve. RESULTS: The average intraoperative blood flow in RCAVFs was 156 mL/min. Patients with an intraoperative blood flow equal or lower than the determined cutoff point of 160 mL/min, showed a 3.03 times increased risk of AVF maturation failure after 6 weeks, compared with patients with a higher intraoperative blood flow (P < .001). CONCLUSIONS: The intraoperative blood flow in RCAVFs measured by TTFM provides an adequate means of predicting AVF nonmaturation 6 weeks after surgery. For RCAVFs, a cutoff point for intraoperative blood flow of 160 mL/min is recommended for maximum sensitivity and specificity to predict AVF maturation failure after 6 weeks.

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 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.