Arm Vein Research Articles

Midline Catheter-Associated Thrombosis (MCAT): Does Tip Location in the Axillary Vein Increase Risk?

Midline catheters, used for short- and intermediate-term venous access, are recommended to be placed with the tip in an upper arm vein rather than more proximally, in the axillary vein. Despite guidelines recommending against proximal location of the midline catheter tip, the impact of midline catheter tip location on midline catheter-associated thrombosis (MCAT) risk is unclear. Using a retrospective cohort of hospitalized patients who not only had a midline catheter but also had a chest x-ray and venous duplex performed, the authors evaluated whether axillary vein tip location increased the risk of MCAT. Of the 41 midline catheters with tips located in an arm vein, 17 (41.5%) resulted in a thrombus versus 7 (38.9%) of the 18 midline catheters with tips located in the axillary vein. When compared to midline catheter tips located in an arm vein, midline catheter tips located in the axillary vein were not significantly more likely to result in MCAT in unadjusted analysis (odds ratio [OR] = 0.90 [95% CI, 0.29-2.79], P =.85) or adjusted analysis (OR = 0.62 [95% CI, 0.18-2.12], P =.45). These findings support emerging evidence that there does not appear to be an increased risk of MCAT in midlines with an axillary vein tip location. The practice of avoiding the axillary vein for midline catheter tip placement should be reconsidered.

Modified medial approach for the treatment of fractures of the lower third of the humeral shaft: An anatomical study

BackgroundThe anatomical study of the modified medial approach for addressing fractures of the distal third of the humeral shaft aimed to elucidate the benefits of this method in providing optimal exposure for surgical intervention. MethodsSixteen upper limb specimens from eight cadavers, obtained from the Anatomy Teaching Department of Fujian Medical University, were dissected. Three-dimensional anatomical structures were mapped onto a two-dimensional coordinate system. Key anatomical structures relevant to the modified medial approach, including the medial cutaneous nerve, musculocutaneous nerve, ulnar nerve, basilic vein, brachial artery, superior ulnar collateral artery, and inferior ulnar collateral artery, were documented in detail. ResultsThe average humeral shaft length measured (29.22 ± 2.78) cm, with its medial surface being flat and well-suited for plate fixation. The basilic vein, located superficially in the upper arm's first quadrant, measured (1.35 ± 0.35) cm from the most prominent point of the medial epicondyle of the humerus, with the deep fascia being penetrated at (12.41 ± 1.71) cm. The basilic vein serves as a key landmark for the modified medial approach. The nervi cutanei antebrachii medialis, running along the medial biceps humerus, closely accompanies the basilic vein, perforating the deep fascia above the medial epicondyle and extending anterior external and posterior medial branches. These branches are positioned (0.80 ± 0.17) cm and (0.45 ± 0.29) cm, respectively, from the basilic vein. Additionally, all nervi cutanei antebrachii medialis pass anteriorly to the basilic vein before continuing distally to the forearm. The ulnar nerve initially accompanies the basilic vein in the upper arm but diverges posteriorly without branching at (14.75 ± 1.74) cm, with the maximum separation from the basilic vein measuring (2.28 ± 0.59) cm. The brachial artery bifurcates into the superior and inferior ulnar collateral arteries along the humeral shaft. The superior collateral ulnar artery primarily supplies the ulnar nerve, positioned (14.14 ± 1.27) cm from the medial epicondyle, which ensures a sufficient blood supply for operative procedures. The musculocutaneous nerve and radial nerve branch are located in the lateral region of the brachial muscle, with minimal postoperative impact on muscle strength when splitting the brachial muscle by one-third. ConclusionsThe modified medial approach, as revealed by anatomical studies, focuses on the fracture site with a straight skin incision aligned between the most prominent point of the medial epicondyle and the midpoint of the axilla, positioned one transverse finger from the radial side. Using the basilic vein as a reference, major vessels and nerves remain undisturbed, ensuring a safe operative zone. This technique allows for significant exposure of both the anterior and external humeral shaft fracture site and the ulnar side butterfly fragment while minimizing tissue damage and facilitating rapid recovery. The approach offers notable clinical value due to its reduced invasiveness and accelerated postoperative rehabilitation.

Outcomes of Prosthetic and Biological Grafts Compared to Arm Vein Grafts in Patients with Chronic Limb Threatening Ischemia

ObjectivesThe optimal conduit for infrainguinal bypass (IIB) is single segment great saphenous vein (GSV). Unfortunately, GSV is not always available in patients with chronic limb threatening ischemia (CLTI). Other graft choices include arm vein grafts (AV), prosthetic grafts (PG) or biologic grafts (BG). Current data regarding the durability and limb salvage rates of those options is scarce, hence we aimed to investigate the impact of alternative graft types on post-operative and long-term outcomes on IIB in patients with CLTI. MethodsThe Vascular Quality Initiative (VQI) database was queried for patients undergoing IIB from January 2003 to April 2024. Patients were stratified into three groups: arm vein (cephalic, basilic), prosthetic grafts [Dacron, polytetrafluoroethylene (PTFE)], and biologic grafts (cadaveric, homograft, or xenograft). Saphenous vein grafts (greater and lesser saphenous) were excluded. Multivariate logistic regression analyzed postoperative outcomes: 30-day mortality, major adverse cardiovascular events (MACE), graft occlusion, prolonged length of stay >7days (PLOS), packed red blood cell (pRBC) transfusion >2 units, and infection. Cox Regression was used to report one-year outcomes: mortality, major amputation (above-ankle), and major adverse limb events (MALE defined as major amputation, thrombectomy or reintervention). ResultsA total of 9165 IIB procedures have been analyzed: AV 417 (4.55%); PG 7520 (82.05%); BG 1228 (13.40%). Compared to AV, patients receiving PG had higher odds of infection (aOR 2.89, p=0.045) and higher hazard of one-year mortality (aHR 1.51, p=0.035). On the other hand, patients receiving BG had higher risk of graft occlusion (aOR 4.55, p=0.040) and infection (aOR 2.78, p=0.046) as well higher hazard of one-year mortality (aHR 1.53, p=0.040), amputation (aHR 1.72, p=0.019) and amputation or death (aHR 1.52, p=0.005) compared to AV. After stratifying by bypass configuration, AV had the highest overall survival and amputation-free survival among the three alternative conduits in below-knee popliteal and tibial bypass targets. ConclusionsIn this large multi-institutional study investigating alternative conduits to GSV, AV are found to be the most resistant to infections and are associated with the best overall survival and limb salvage outcomes compared to PG and BG particularly in below-knee distal targets. In cases where no GSV is available, AV and PG are acceptable alternatives with comparable one-year amputation-free survival and MALE-free survival rates. On the other hand, BG are associated with higher risk of graft occlusion and lower freedom from major amputation and death compared to AV.

To evaluate the complication and patency rate of superficial femoral vein transposition in tertiary care center.

When all access options in the upper extremity have been exhausted, an autologous access can be created in lower extremity. The purpose of this study is to report our experience with superficial femoral vein transposition (SFVT) results in terms of postoperative complication and patency rate. In the time period from January 1, 2019 to April 30, 2021, thirty-five cases of SFVT performed at our large tertiary care center Sindh Institute of Urology and Transplantation (SIUT). All patients had exhausted upper arm veins or had central vein obstructions. Medical records of all patients were traced, patients were interviewed using a standard proforma and evaluated the current AVF function in the OPD clinic or by telephone calls. Data including demographics and postoperative complications were collected. Thirty-nine cases of SFVT performed at our institute. Three were immediately lost to follow up so they were excluded from the study. Mean patient age was 30 ± 13.4 years. Most of our patients were females (57%) and 15 males (43%) with an average age of 29.05 years. The most common underlying renal diseasewas unknown in 16 (45%).Thirty-five patients included in the analysis; out of which primary failure observed in 4 patients, three patients were expired before fistula maturation and 3 were expired before 6 months. The remaining 25 fistulas patency rates were estimated. No any patient died due to fistulas related complication; patients died due to their primary disease. Our study shows that with appropriate patient selection, SFVT have low infection rates and patency that is comparable with other access types.

Evaluation of the Importance of Genetic Polymorphisms in Genes Expressing Cancer-Metabolizing Enzymes (Cyp1a1 and Gstm1) in Oral Submucous Fibrosis.

Genetic polymorphisms are common and contribute significantly to human illnesses. This study was carried out to evaluate the importance of genetic variations in the genes expressing cancer-metabolizing enzymes (CYP1A1 and GSTM1) in individuals experiencing oral submucous fibrosis (OSMF). Based on the clinical and histological characteristics of OSMF, 40 patients were chosen for the study; 10 of these patients had considerable polymorphism and malignant transformation; therefore, they were placed in a different group. After receiving written agreement, 30 normal subject patients were also picked for the study. For both normal and OSMF patients, tissue samples and 2 ml of peripheral venous blood were drawn from the arm vein and placed in a heparinized test tube. Electrophoresis on 0.8% agarose gel was used to verify genomic DNA. The GSTM1 polymorphism, CYP1A1 polymorphism was 10.41% and 15.27% in normal subjects. The GSTM1 polymorphsm, CYP1A1 polymorphism was 16.21% and 8.14% in early OSMF. The GSTM1 polymorphsm, CYP1A1 polymorphism was 20.31% and 28.56% in moderate OSMF. The GSTM1 polymorphsm, CYP1A1 polymorphism was 8.12% and 12.54% in moderate OSMF. Finally, GSTM1 polymorphism was 60.47% in OSMF+ CA, while CYP1A1 polymorphism was 40.21%. The GSTM1 gene polymorphism and CYP1A1 gene polymorphism were maximum in OSMF+ CA category. There is a significant role of genetic variations in the genes expressing cancer-metabolizing enzymes (CYP1A1) and GSTM1 in individuals experiencing OSMF.

#1387 Comprehensive evaluation of clinical consequences in diverse forms of fistula elevation procedure

Abstract Background and Aims Arteriovenous fistula (AVF) superficialization is a recommended alternative autologous vascular access (VA) in patients for whom conventional AVF creation is not possible because of insufficient forearm vessels. This procedure utilizes a deeply located vein as an outflow conduit in AVF creation and makes the vein accessible for cannulation. Tunnel transposition (TT) is employed in a standard manner as a venous superficialization technique. This is accomplished by tunneling the transected vein through a subcutaneous tunnel. However, TT is frequently associated with stenosis at the area of transposition because the transposed vein is torsed, kinked, or compressed by external tissue. Thus, TT tends to be exclusively applied to the basilic vein in the upper arm considering both the anatomic positional relation and the inherent limitations of this procedure. We recently reported that elevation transposition (ET) can serve as a practical substitute for TT (Contrib Nephrol. 2019:198:1-11). ET is a simplified minimally invasive superficialization approach in which the vein is elevated and positioned in a subcutaneous pocket immediately beneath the incision. In AVF superficialization employing ET (i.e., fistula elevation procedure [FEP]), three potential outflow veins are available in the upper arm: the cephalic, basilic, and brachial veins. This study was performed to comprehensively evaluate the clinical consequences of three valid FEP techniques to ascertain whether they are reasonable alternatives to autologous VA and which, if any, have superior performance. Method The demographic and outcome data of 111 patients who underwent the FEP from April 2016 to June 2023 were retrospectively collected and analyzed. The outcomes of the three fistula techniques were assessed and compared in terms of patency rates, requirements for VA intervention therapy (VAIVT), and complication rates. Results The mean follow-up period was 36.2 ± 20.1 (range, 1.3-80.8) months. The basilic, cephalic, and brachial vein-based FEP was performed in 63.1%, 23.4%, and 13.5% of cases, respectively. The overall cumulative primary and secondary patency rates were 76.2% and 98.2% at 1 year and 70.7% and 97.0% at 2 years, respectively. VAIVT was required in 32.4% of cases, and the patency rates at 1 and 2 years after VAIVT were 65.3% and 62.0%, respectively. There were no significant differences in these patency rates among the three FEP types. Minor complications such as lymphorrhea or epidermolysis occurred in only 4.5% of cases. Conclusion Our results suggest that the FEP provides three equivalently reliable options to accommodate the deeply located venous anatomy of the upper arm on individual-patient basis. The diversity of the FEP may contribute to avoiding prosthetic VA and central venous catheter-based dialysis, at least in part, by expanding the applicability of the autologous VA.

Single-Cell Analyses Offer Insights into the Different Remodeling Programs of Arteries and Veins.

Arteries and veins develop different types of occlusive diseases and respond differently to injury. The biological reasons for this discrepancy are not well understood, which is a limiting factor for the development of vein-targeted therapies. This study contrasts human peripheral arteries and veins at the single-cell level, with a focus on cell populations with remodeling potential. Upper arm arteries (brachial) and veins (basilic/cephalic) from 30 organ donors were compared using a combination of bulk and single-cell RNA sequencing, proteomics, flow cytometry, and histology. The cellular atlases of six arteries and veins demonstrated a 7.8× higher proportion of contractile smooth muscle cells (SMCs) in arteries and a trend toward more modulated SMCs. In contrast, veins showed a higher abundance of endothelial cells, pericytes, and macrophages, as well as an increasing trend in fibroblasts. Activated fibroblasts had similar proportions in both types of vessels but with significant differences in gene expression. Modulated SMCs and activated fibroblasts were characterized by the upregulation of MYH10, FN1, COL8A1, and ITGA10. Activated fibroblasts also expressed F2R, POSTN, and COMP and were confirmed by F2R/CD90 flow cytometry. Activated fibroblasts from veins were the top producers of collagens among all fibroblast populations from both types of vessels. Venous fibroblasts were also highly angiogenic, proinflammatory, and hyper-responders to reactive oxygen species. Differences in wall structure further explain the significant contribution of fibroblast populations to remodeling in veins. Fibroblasts are almost exclusively located outside the external elastic lamina in arteries, while widely distributed throughout the venous wall. In line with the above, ECM-targeted proteomics confirmed a higher abundance of fibrillar collagens in veins vs. more basement ECM components in arteries. The distinct cellular compositions and transcriptional programs of reparative populations in arteries and veins may explain differences in acute and chronic wall remodeling between vessels. This information may be relevant for the development of antistenotic therapies.

Femoral vein translocation for complex hemodialysis access

ObjectiveVascular 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. MethodsA 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. ResultsA 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. ConclusionsFVT 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.

Abstract 3089: Do Arteries And Veins Have Different Remodeling Programs?

Aims: Arteries and veins respond differently to injury, with significantly higher rates of postsurgical failure in the latter. The biological reasons for this discrepancy are not well understood, which is a limiting factor for the development of vein-targeted therapies. This study contrasts peripheral arteries and veins at the single-cell level, with a focus on cell populations with remodeling potential. Methods and Results: Upper arm arteries (brachial) and veins (basilic/cephalic) from 27 organ donors were compared using a combination of bulk and single-cell RNA sequencing, proteomics, flow cytometry, and histology. The cellular atlases of six arteries and veins demonstrated a significantly higher proportion of smooth muscle cells (SMCs) in arteries vs. higher counts of fibroblasts in veins. In both types of vessels, clustering analyses identified an intermediate myofibroblast population with repair characteristics. Both arterial and venous myofibroblasts were characterized by upregulation of F2R , FN1, POSTN, COL8A1, and ITGA10 , and were confirmed by histology and F2R/CD90 double staining by flow cytometry. However, bioinformatic analyses indicate that arterial myofibroblasts are phenotypically related to both SMCs and fibroblasts, whereas in veins they are predominantly fibroblast derived. Differences in wall structure further explain the distinct contributions of SMC and fibroblasts to these reparative populations. PDGFRA + fibroblasts are almost exclusively located outside the external elastic lamina in arteries, while widely distributed throughout the venous wall. In line with a higher abundance of fibroblasts and fibroblast-derived reparative cells, ECM-targeted proteomics confirmed a higher abundance of fibrillar collagens in veins vs. more basement ECM components in arteries. These differences in ECM composition are also associated with vessel-specific modulation of myofibroblast differentiation. Conclusions: The distinct cellular origins and transcriptional programs of myofibroblast populations in arteries and veins may explain differences in acute and chronic wall remodeling between vessels. This information is relevant for the development of anti-stenotic therapies.

Upper extremity versus lower extremity for secondary access during transcatheter aortic valve implantation: rationale and design of the randomised TAVI XS trial.

During transcatheter aortic valve implantation (TAVI), secondary access is required for angiographic guidance and temporary pacing. The most commonly used secondary access sites are the femoral artery (angiographic guidance) and the femoral vein (temporary pacing). An upper extremity approach using the radial artery and an upper arm vein instead of the lower extremity approach using the femoral artery and femoral vein may reduce clinically relevant secondary access site-related bleeding complications, but robust evidence is lacking. The TAVI XS trial is amulticentre, randomised, open-label clinical trial with blinded evaluation of endpoints. Atotal of 238 patients undergoing transfemoral TAVI will be included. The primary endpoint is the incidence of clinically relevant bleeding (i.e. Bleeding Academic Research Consortium (BARC) type2, 3or 5bleeding) of the randomised secondary access site (either diagnostic or pacemaker access, or both) within 30days after TAVI. Secondary endpoints include time to mobilisation after TAVI, duration of hospitalisation, any BARC type2, 3or 5bleeding, and early safety at 30days according to Valve Academic Research Consortium‑3 criteria. The TAVI XS trial is the first randomised trial comparing an upper extremity approach to alower extremity approach with regard to clinically relevant secondary access site-related bleeding complications. The results of this trial will provide important insights into the safety and efficacy of an upper extremity approach in patients undergoing transfemoral TAVI.

A New Equation to Estimate Peripherally Inserted Central Catheter Length.

Background and Objectives: Peripherally inserted central catheter (PICC) placement plays an important role in clinical practice. This study aimed to provide an equation for the proper estimation of catheter length in cases of PICC placement without imaging guidance in relation to patient height, weight, sex, and age. Materials and Methods: For 1137 PICC placement cases in both arm veins of 954 patients at a single center, the elbow crease to the cavoatrial junction length (ECL) was calculated as follows: ECL = (PICC length) + (distance from the elbow crease to the puncture site). We analyzed the relationship between ECL and patient characteristics and suggested a new equation for ECL based on height, weight, sex, and age. Results: The average ECL was 48.0 ± 2.4 cm in the right side and 51.0 ± 3.0 cm in the left side. ECL in the right arm was significantly correlated with patient height, sex, and age, whereas the ECL in the left arm was additionally significantly correlated with patient weight. The ECL (cm) prediction model was as follows: right ECL = 26.32 + 1.33 × (female = 1, male = 2) - 0.02 × age (years) + 0.13 × height (cm); left ECL = 22.09 + 1.28 × (female = 1, male = 2) + 0.02 × age (years) + 0.14 × height (cm) + 0.042 × weight (kg). Conclusions: The appropriate PICC length was predicted based on the patient's height, weight, sex, and age. The equations in our study can help predict the optimal catheter length and can be automatically calculated using computerized patient information for bedside procedures in PICC.

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

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. 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 February2023. 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%. 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.

Using Upper Arm Vein as Temporary Pacemaker Access Site: A Next Step in Minimizing the Invasiveness of Transcatheter Aortic Valve Replacement

Background The femoral vein is commonly used as a pacemaker access site during transcatheter aortic valve replacement (TAVR). Using an upper arm vein as an alternative access site potentially causes fewer bleeding complications and shorter time to mobilization. We aimed to assess the safety and efficacy of an upper arm vein as a temporary pacemaker access site during TAVR. Methods We evaluated all patients undergoing TAVR in our center between January 2020 and January 2023. Upper arm, femoral, and jugular vein pacemaker access was used in 255 (45.8%), 191 (34.3%), and 111 (19.9%) patients, respectively. Clinical outcomes were analyzed according to pacemaker access in the overall population and in a propensity-matched population involving 165 upper arm and 165 femoral vein patients. Primary endpoint was Bleeding Academic Research Consortium (BARC) type 2, 3, or 5 pacemaker access site-related bleeding. Results In the overall population, primary endpoint was lowest for upper arm, followed by femoral and jugular vein access (2.4% vs. 5.8% vs. 10.8%, p = 0.003). Time to mobilization was significantly longer (p < 0.001) in the jugular cohort compared with the other cohorts. In the propensity-matched cohort, primary endpoint showed a trend toward lower occurrence in the upper arm compared with the femoral cohort (2.4% vs. 6.1%, p = 0.10). Time to mobilization was significantly shorter (480 vs. 1140 min, p < 0.001) in the upper arm cohort, with a comparable skin-to-skin time (83 vs. 85 min, p = 0.75). Cross-over from upper arm pacemaker access was required in 17 patients (6.3% of attempted cases via an upper arm vein). Conclusions Using an upper arm vein as a temporary pacemaker access site is safe and feasible. Its use might be associated with fewer bleeding complications and shorter time to mobilization compared with the femoral vein.

The intricate cellular ecosystem of human peripheral veins as revealed by single-cell transcriptomic analysis.

The venous system has been historically understudied despite its critical roles in blood distribution, heart function, and systemic immunity. This study dissects the microanatomy of upper arm veins at the single cell level, and how it relates to wall structure, remodeling processes, and inflammatory responses to injury. We applied single-cell RNA sequencing to 4 non-diseased human veins (3 basilic, 1 cephalic) obtained from organ donors, followed by bioinformatic and histological analyses. Unsupervised clustering of 20,006 cells revealed a complex ecosystem of endothelial cell (EC) types, smooth muscle cell (SMCs) and pericytes, various types of fibroblasts, and immune cell populations. The venous endothelium showed significant upregulation of cell adhesion genes, with arteriovenous zonation EC phenotypes highlighting the heterogeneity of vasa vasorum (VV) microvessels. Venous SMCs had atypical contractile phenotypes and showed widespread localization in the intima and media. MYH11+DESlo SMCs were transcriptionally associated with negative regulation of contraction and pro-inflammatory gene expression. MYH11+DEShi SMCs showed significant upregulation of extracellular matrix genes and pro-migratory mediators. Venous fibroblasts ranging from secretory to myofibroblastic phenotypes were 4X more abundant than SMCs and widely distributed throughout the wall. Fibroblast-derived angiopoietin-like factors were identified as versatile signaling hubs to regulate angiogenesis and SMC proliferation. An abundant monocyte/macrophage population was detected and confirmed by histology, including pro-inflammatory and homeostatic phenotypes, with cell counts positively correlated with age. Ligand-receptor interactome networks identified the venous endothelium in the main lumen and the VV as a niche for monocyte recruitment and infiltration. This study underscores the transcriptional uniqueness of venous cells and their relevance for vascular inflammation and remodeling processes. Findings from this study may be relevant for molecular investigations of upper arm veins used for vascular access creation, where single-cell analyses of cell composition and phenotypes are currently lacking.

Association of glutamine synthetase polymorphisms rs2296521, rs10911021 and rs12136955 with plasma ammonia concentration in valproic acid-treated Egyptian epilepsy patients.

The use of valproic acid (VPA) in the treatment of some psychiatric and neurological disorders such as bipolar disorder, migraines, and epilepsy is associated with hyperammonemia. However, the mechanism of this negative effect of VPA is unclear. In this study, we investigate gene glutamate-ammonia ligase (GLUL) polymorphisms for the glutamine synthetase (GS) enzyme, a key enzyme that catalyzes the removal of ammonia by incorporating it with glutamate to form glutamine, and we investigate whether it has a relationship with the emergence of hyperammonemia during VPA-based therapy. We enrolled 180 Egyptian epilepsy patients in this study. Patient history, general and neurological examination and blood samples from arm veins were taken. Real time TaqMan PCR polymorphism for three polymorphism SNPs (rs2296521, rs10911021 and rs12136955) of GLUL was done. We assessed the relationship between the patient features, including three GLUL polymorphisms, and the development of hyperammonemia during VPA-based therapy. We found that the ammonia levels showed a positive correlation with VPA treatment duration (p = 0.015) and a negative correlation with carbamazepine total dose per day (p = 0.027) and with WBCs count (p = 0.026). Also, female patients having rs2296521 SNPs with the A allele and patients having rs10911021 SNPs with the C allele were at high risk for elevated plasma ammonia levels. Moreover, patients having rs12136955 SNPs with the A allele or associated hypertension as a co-morbidity were at high risk for elevated plasma ammonia levels. Female patients who have rs2296521 with the A allele, rs10911021 with the C allele, or rs12136955 with the A allele, are independent risk factors for elevated plasma ammonia levels during VPA-based therapy. Moreover, carbamazepine combined therapy may protect against the development of hyperammonemia in VPA-treated patients.

Prosthetic Conduit Use Does Not Adversely Impact Outcomes after Open Repair of Popliteal Artery Aneurysms

Single segment, greater saphenous vein (GSV) conduit is considered the optimal bypass conduit among patients undergoing bypass surgery for peripheral artery disease (PAD). While this data has been extrapolated to patients undergoing bypass for popliteal artery aneurysms (PAA), the pathophysiology of PAA is inherently different when compared to PAD, and the impact of conduit type on long-term outcomes after open repair of PAA remains unclear. A multicenter database of five regional hospitals was retrospectively reviewed for all patients with PAA undergoing open surgical repair. Data were collected on demographic information, operative details, medications, and postoperative outcomes. Kaplan-Meier curves were used to compare freedom from major adverse limb events (MALE) following GSV versus prosthetic bypass. Cox proportional hazards model was used to identify patient-level characteristics associated with MALE, which was defined as major ipsilateral limb amputation or reintervention for graft patency. From 1999-2020, a total of 101 patients with PAA underwent open exclusion and bypass surgery. Median follow-up period was 4.2 years (interquartile range, 1.3-7.4 years), and complete data were available for 99 (98.0%) patients. The majority of patients were male (99.0%) and Caucasian (93.9%). Only 11.1% of procedures were emergent, with the remainder (88.9%) being elective. All patients underwent medial exposure with a below-knee popliteal bypass target (100%). Bypass conduits included GSV (69.7%), prosthetic conduit (28.3%), and two (2.0%) alternative conduits (one spliced arm vein, one cryopreserved vein). Patients undergoing prosthetic bypass were older (72 vs 66 years, p=0.001) and had similar rates of medical comorbidities. Compared with the GSV group, patients with prosthetic conduits were more frequently placed on postoperative anticoagulation (60.7% vs 23.2%, p<0.001). Conduit type did not impact postoperative complication rates (p=NS each). MALE rates were low overall (19.2% at two years), and similar when stratified by conduit type (log rank p=0.47). On multivariable analysis, emergent bypass was associated with MALE (hazard ratio [HR] 5.73, 95% confidence interval [CI] 2.07-15.85, p<0.001). Prosthetic conduit usage (HR 1.00, 95% CI, 0.40-2.51, p=0.99) and postoperative anticoagulation (HR 1.02, 95% CI 0.42-2.50, p=0.97) were not associated with MALE. Open repair of PAA is associated with excellent long-term outcomes. Prosthetic bypass is a comparable alternative to autogenous conduit for below-knee popliteal bypass targets, and lack of suitable GSV should not prohibit open surgical repair when indicated.

Inflow Artery Aneurysmal Degeneration After Long Term Native Arteriovenous Fistula for Haemodialysis

Inflow arterial aneurysms are a rare but serious complication after long term arteriovenous fistulae (AVF), probably due to arterial wall remodelling after an increase in flow and shear stress, and kidney transplantation with immunosuppressive therapy. This study aimed to describe the outcomes of surgical treatment and long term follow up in a large cohort. This prospective cohort study collected data from patients with a true inflow artery aneurysm after AVF creation that was surgically repaired between 2010 and 2022. Anastomotic and infected aneurysms or post-puncture pseudoaneurysms were excluded. Demographic data, access characteristics, symptoms, treatment strategies, and long term follow up were recorded; patency was estimated using Kaplan-Meier survival analysis. During the study period, 28 patients (64% men, mean age 60.1 years) were treated surgically for aneurysmal degeneration of the axillary or brachial (n= 23) or radial (n= 5) artery after an AVF (10 distal, 18 proximal) performed a mean of 18.3 ± SD 7.9 years previously. Most AVFs were ligated or thrombosed, while all patients except one had previously received kidney transplants. Most of the cases (n= 18) were symptomatic: 13 with pain or swelling, four with distal embolisation, and one rupture. They were repaired by aneurysm partial excision and graft interposition (11 great saphenous vein, six ipsilateral basilic vein, three cephalic vein, and two PTFE graft), ligation (n= 3), or direct end to end anastomosis (n= 3). No major complications occurred before discharge, after a mean hospital stay of 2.4 days. After a mean follow up of 4.8 ± 3.3 years, three cases presented complications: two recurrent proximal brachial aneurysms were repaired with an additional proximal interposition graft (one with further late infected pseudoaneurysm) and an asymptomatic post-traumatic graft thrombosis. Five year primary and secondary patency was 84% and 96%, respectively. Aneurysmal degeneration of the inflow artery is an unusual complication during long term follow up of AVFs. Aneurysm excision and, in general, autogenous graft interposition using the saphenous or ipsilateral arm vein is a safe and effective strategy.

Review on Car-T Cell Therapy for Cancer Treatment

A set of illnesses known as cancer involve abnormal cell proliferation and have the ability to invade or spread to different bodily regions. These stand in contrast to benign tumours, which remain stationary. A lump, unusual bleeding, a persistent cough, unexplained weight loss, and a change in bowel habits are all potential warning signs and symptoms. Chimeric antigen receptors (CARs), often referred to as chimeric immunoreceptors or artificial T cell receptors, are receptor proteins that have been modified so that T cells now have the ability to target a particular antigen. Because they integrate antigen-binding and T cell activation functions into a single receptor, the receptors are chimeric. CAR T cell treatment is a form of treatment in which the patient's immune cells, called T cells, are altered in a lab so that they will adhere to and kill cancer cells. An apheresis machine receives blood from a vein in the patient's arm through a tube, filters out all white blood cells—including T cells—and returns the remaining blood back to the patient. The T cells are then genetically modified in the lab to contain the gene for a unique receptor known as a chimeric antigen receptor (CAR). The CAR T cells are multiplied in a lab before being infused into the patient in large numbers. In order to destroy cancer cells, the CAR T cells can connect to an antigen on the cancer cells.

Application of Biophysical Properties of Meridians in the Visualization of Pericardium Meridian.

The biophysical properties of the meridian system, an important concept of traditional Chinese medicine, include low impedance, resounding voice, and high acoustic conductance, all of which are helpful for elucidating the essence of meridians. To visualize the human pericardium meridian (PC) based on the resounding voice property of meridians. Visualization of the PC was performed by injection of fluorescein sodium at the PC6 acupoint (Neiguan) on the PC. Before injection, percussion active points (PAPs) were identified by the virtue of their resounding voice properties. After injection, the trajectories of fluorescein migration throughout the body surface were recorded and analyzed. The distribution of fluorescein in the tissue was further studied using cross-sections of hind limbs of mini-pigs, in which fluorescein was injected into low impedance points. The identified PAP lines were colocalized with PC. Following intradermal fluorescein injection, 1-3 fluorescent lines, which were unrelated to the arm veins, were observed in 7 of 10 participants; 85.4% of fluorescent signals were coincident with PAPs and their intensity had a negative correlation with the body mass index (r = -0.56, p = 0.045). Cross-sections showed a Y-shaped fluorescence pattern where the two migration lines on the surface were the two vertices of the "Y." The trajectories of fluorescein in the body are suggestive of the anatomical structure of meridians. The PC is related to the deep horizontal interstitial channels that connect to the body surface through vertical interstitial spaces. These biophysical properties and techniques for meridian visualization are valuable for revealing the anatomical structure of meridians.

Efficacy and safety of iliofemoral bypass using arm veins as an alternative conduit for chronic limb-threatening ischemia

ObjectiveThe use of basilic vein in iliofemoral revascularizations was previously described in the literature as an autologous option for the treatment of vascular prosthesis infection and as a primary conduit in patients at high risk of infectious surgical complications. However, the publications available include several different indications and are limited to case reports. Therefore, the aim of this study was to evaluate the outcomes of the use of arm veins as a safe and effective autologous alternative for iliofemoral reconstruction in patients with chronic limb-threatening ischemia (CLTI) and at high risk of prosthesis infection. MethodsWe performed a multicenter, retrospective cohort study with 53 consecutive iliofemoral bypasses using arm veins as an alternative conduit. The procedures were performed between November 2013 and November 2021, exclusively for patients with CLTI classified as TASC aortoiliac C or D with increased risk of postoperative surgical infection. Demographic, clinical variables, and outcomes were collected from a prospective database. Main endpoints were amputation-free survival (AFS) and major adverse cardiovascular events. Secondary endpoints included primary and secondary patencies and overall survival. Cox regression analysis was used to identify the predictors of AFS. Postoperative surgical complications and 30-day mortality were also assessed. ResultsThe mean age was 64.2 ± 8.4 years, with a predominance of male gender. The median follow-up period was 615 days. All patients had CLTI, with a predominance of tissue loss (n = 51; 96.2%) and a median ankle-brachial index of 0.28. The basilic vein was utilized in most procedures (69.8%). Thirty-day major adverse cardiovascular events occurred in five cases (9.4%), and the 30-day mortality rate was 3.8%. The AFS, primary patency, secondary patency, and overall survival in 720 days were 71%, 72%, 89%, and 75%, respectively. Cox regression analysis revealed no association between the variables analyzed for AFS. There was no graft late infection nor pseudoaneurysmal degeneration. ConclusionsIliofemoral bypass using arm veins as an autologous conduit proved to be an effective and safe procedure with low incidence of postoperative cardiovascular complications and high rates of AFS in patients with CLTI. Also, this suggests that arm veins can be an interesting and suitable autologous alternative conduit for iliofemoral reconstructions, especially in cases in which a prosthesis should be avoided or when it is not available.