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.

Venous capacitance and venous return in young adults with typical vasovagal syncope: a cross-sectional study.

Vasovagal syncope (VVS) has a high prevalence in the general population and is associated with potential complications. There is limited information on the possible association between venous capacitance (VC) and venous return (VR), important determinants of preload and VVS. Since the tilt test was reported to yield a high rate of false positive results, the aim of this study was to evaluate whether abnormal VC and VR at baseline could predispose individuals to VVS.To this end, 88 young, healthy volunteers were recruited and classified to 26 (29.5%) who experienced typical VVS and 62 (70.5%) who did not. VC and VR were evaluated with a commercial device and plethysmography applied to the elevated legs. Maximum venous outflow (MVO), segmental venous capacitance (SVC) and MVO/SVC ratio were calculated and averaged.No significant differences between MVO (5.0±0.5 vs 5.6±0.8, p>0.05), SVC (6.0±0.5 vs 6.3±0.8, p>0.05) or MVO/SVC ratio (0.83±0.02 vs 0.86±0.03, p>0.05) were observed for the non-VVS and VVS volunteers, respectively. There was a significant association between a higher MVO and SVC values and a larger decrease in diastolic blood pressure with standing, although correlations were weak (R2=0.0582 and 0.0681, respectively).In conclusion, at baseline, VC and VR are not impaired in healthy volunteers with a history of VVS. It remains unknown if similar results would be found in patients with cardiovascular comorbidities. Also, the sensitivity of VC and VR evaluations to identify a predisposition for VVS following physiological provocations merits further study.

Sharp recanalization for treatment of central venous occlusive disease in hemodialysis patients.

BACKGROUND: The purpose of the present study was to evaluate the technical feasibility and safety of sharp recanalization for central venous occlusive disease (CVOD) in patients requiring hemodialysis. METHODS: Patients with CVOD requiring hemodialysis who had undergone endovascular recanalization using sharp devices, including the stiff end of a guidewire, Chiba needle, or RUS-100 to cross occluded segments after conventional techniques had failed were included. The needle was guided toward a target placed at the opposite end of the occlusion. Although the guidewire was passed though the occlusion, subsequent procedures such as percutaneous transluminal angioplasty could be performed. RESULTS: A total of 27 sharp recanalization procedures in 25 patients were performed. Two attempts failed, 1 patient had undergone two separate successful procedures, and 23 procedures in 23 patients were successful. The overall technique success was 92.6%. The stiff end of a guidewire was the first choice for all the procedures, and recanalization was achieved in 18 patients (66.7%). A Chiba biopsy needle was used in six procedures (22.2%), with 100% technical success. A RUPS-100 set was used in two procedures (7.4%), with one aborted because of concern for complications. The occlusion was subsequently crossed using a Chiba needle. Four minor adverse events (two of mediastinal hematoma and two of chest pain) had occurred, and two major adverse events (pericardial tamponade and acute pleural effusion in one patient [4%], treated with the guidewire stiff-end technique, who recovered after drainage) had occurred. CONCLUSIONS: Sharp recanalization is safe and feasible with high technical success for CVOD in patients requiring hemodialysis who cannot be recanalized using conventional techniques.

Residual volume fraction during walking using wireless air plethysmography in patients with chronic deep venous disease.

OBJECTIVE: Traditional air plethysmography (APG) provides a quantitative measure of the residual volume fraction (RVF) after 10 tiptoe movements. The recent development of a wireless Bluetooth (Bluetooth SIG, Inc, Kirkland, Wash) APG device, the PicoFlow (Microlab Elettronica, Padua, Italy), enabled us to measure RVF during normal walking. The aim of our study was to compare the RVF obtained during tiptoeing with RVF obtained during normal walking in patients with deep venous pathology (ie, reflux and/or obstruction). METHODS: A total of 61 consecutive symptomatic patients (27 women and 34 men; median age, 46 years; range, 18-79 years) with chronic venous disease due to deep venous pathology (venous reflux or obstruction, or both) before treatment or persisting after intervention were included in the present study. Of the 122 total limbs examined, 79 were affected by deep chronic venous disease and 43 contralateral limbs were normal with normal deep veins and acted as controls. The APG examination was performed using the PicoFlow device using the standard examination technique. The RVF was calculated from the residual volume at the end of 10 tiptoe movements and also during normal walking. RESULTS: At the end of the 10 tiptoe movements, the mean ± standard deviation RVF was 27.0% ± 13.2% in the limbs with normal deep veins and 38.8% ± 16.9% in the limbs with deep chronic venous disease (P < .001). During walking, when a steady state in volume was reached, the RVF was 26.3% ± 17.8% in the limbs with normal deep veins and 43.1% ± 18.6% in limbs with deep venous disease (P < 0.001). A significant difference was found between limbs with normal deep veins and limbs with deep venous reflux, irrespective of which exercise was performed. However, the mean RVF between the limbs with normal deep veins and those with outflow obstruction in the absence of reflux was significant during walking (P = .012) but not during tiptoeing (P = .212). The mean RVF was higher in the C3 to C6 limbs than in the C0 to C2 limbs with tiptoeing (29.9% ± 14.5% vs 38.3% ± 17.0%; P < .006). Similar results were obtained with walking (29.2% ± 18.0% vs 42.4% ± 18.8%; P < .004). CONCLUSIONS: In limbs with normal deep veins and deep veins with reflux, the RVF measured during walking with wireless APG was similar to the RVF obtained during tiptoeing. However, in the limbs with outflow obstruction in the absence of reflux, the RVF during walking was higher than the RVF after tiptoeing. Our results have shown that the evaluation of RVF during walking is feasible and practical.

The presence of a pathologic perforator may be predictive of central venous pathology and multilevel disease in severe chronic venous insufficiency.

OBJECTIVES: The treatment of a refluxing perforator is indicated in the setting of severe chronic venous insufficiency, but there are limited data on the presence of multilevel disease in these patients. This study sought to evaluate whether the presence of a pathologic perforator is predictive of the presence of central venous pathology. METHODS: This study was a retrospective review of the institutional Vascular Quality Initiative database. Consecutive patient limbs were identified that underwent intervention of refluxing perforators. The patients who underwent imaging, including magnetic resonance imaging or computed tomography (group A), were compared with those who did not undergo imaging (group B). The treated limbs in group A were also compared with the contralateral limbs as an internal control. Anatomical findings on imaging were analyzed by two independent investigators. The primary outcome was the presence and degree of central venous stenosis as measured by an orthogonal diameter reduction of >50% by axial imaging. Secondary outcomes included demographic and clinical differences between the two groups, frequency of central venous intervention, and duration of ulcer healing. Standard statistical analysis was performed. RESULTS: Ninety-three patient limbs underwent treatment of a pathologic perforator, with 30 in group A and 63 in group B. The following demographic and clinical variables were higher in group A compared with group B: male sex, body mass index, deep venous thrombosis history, recent or active anticoagulation use, perforator diameter, Clinical Etiology Anatomy Pathophysiology class 4, 5, or 6, and Venous Clinical Severity Score. Radiographic analysis of group A revealed concordance of a treated pathologic perforator with an ipsilateral central venous stenosis in 53.3% of patients, and a higher frequency of common iliac vein stenosis (50% vs 21.4%, P = .024) and external iliac vein stenosis (20% vs 0%, P = .012) compared with the contralateral limbs. When separated by the left or right limb, the left limbs exhibited a greater degree of common iliac vein stenosis as compared with the contralateral limbs (50.7% ± 20.9% vs 16.3% ± 16.5%, P < .001) as well as a greater frequency of >50% common iliac vein stenosis (46.7% vs 13.3%, P = .046). The right limbs exhibited a greater frequency of >50% external iliac vein stenosis as compared with the contralateral limbs (33.3% vs 0%, P = .022). CONCLUSIONS: This study suggests that patients with severe chronic venous insufficiency who undergo treatment for a pathologic perforator may have additional ipsilateral central venous pathology, supporting the presence of multilevel disease. Additional axial imaging might unmask central venous pathology and provide another option for treatment.

Acute effects of graduated and progressive compression stockings on leg vein cross-sectional area and viscoelasticity in patients with chronic venous disease.

OBJECTIVE: To determine the effects of graduated and progressive elastic compression stockings (ECS) on postural diameter changes and viscoelasticity of leg veins in healthy controls and in limbs with chronic venous disease (CVD). METHODS: In 57 patients whose legs presented with C1s, C3, or C5 CEAP classes of chronic venous disease and were treated primarily with compression, and 54 healthy controls matched for age and body mass index, we recorded interface pressures (IFP) at 9 reference leg levels. Cross-sectional areas of the small saphenous vein (SSV) and a deep calf vein (DCV) were measured with B-mode ultrasound with patients supine and standing, recording the force (PF) applied on the ultrasound probe to collapse each vein with progressive ECS, and with and without graduated 15 to 20 mm Hg and 20 to 36 mm Hg elastic stockings. We chose these veins because they were free of detectable lesion and could be investigated at the same level (mid-height of the calf), and their compression by the ultrasound probe was not hampered by bone structures. RESULTS: IFP decreased from ankle to knee with graduated 15 to 20 and 20 to 36 mm Hg, but increased with progressive ECS, and were 8.4 to 13.8 mm Hg lower for C1s than for control or C3 and C5 limbs. Without ECS, the SSV median [lower-upper quartile] cross-sectional area was 4.9 mm2 [3.6-7.1 mm2] and 7.1 mm2 [3.0-9.9 mm2] in C3 and C5 limbs versus 2.9 mm2 [1.8-5.2 mm2] and 3.8 mm2 [2.1-5.4 mm2] in controls (P < .01), respectively, while supine and standing. It remained greater in C3 and C5 than in C1s and control limbs wearing any ESC. Wearing compression, especially with progressive ECS, decreased the SSV and DCV cross-sectional area only with patients supine, thus decreasing postural changes, which remained highly diverse between individuals. The SSV cross-sectional area versus PF function traced a hysteresis loop of which the area, related to viscosity, was greater in C3 and C5 limbs than controls, even with graduated 15 to 20 or 20 to 36 mm Hg ECS. Progressive ECS decreased vein viscosity in the supine position, whereas 20 to 36 mm Hg and progressive ECS increased distensibility in the standing position. CONCLUSIONS: ECS decrease the cross-sectional area of SSV and DCV with patients supine, but not upright. C1s limbs show distinctive features, especially regarding IFP. Graduated 20 to 36 mm Hg and progressive stockings lower viscosity and increase distensibility of the SSV.

A retrospective cohort study comparing high and low balloon inflation pressure on technical success and patency for treating central venous lesions in patients on chronic hemodialysis.

BACKGROUND: We aimed to analyze the success rates and the access patency rates at 12 months between patients on chronic hemodialysis with symptomatic central venous stenosis (CVS) or occlusion (CVO), receiving high or low balloon inflation pressure for treatment. METHODS: We performed a retrospective study in which angioplasty balloons were inflated using a low-pressure or a high-pressure for the management of hemodialysis patients with CVS/CVO. The outcomes of this study were the success rate and the access patency rates at 12 months after balloon angioplasty, and the differences between groups were compared. RESULTS: We included a total of 74 patients on hemodialysis and assigned them to the low-pressure or the high-pressure groups. Success rates in patients of the high-pressure group (94.12%) were higher than those in patients of the low-pressure group (67.50%) (p = 0.005). With a total of 59 patients with technical success, at 6 and 12 months after angioplasty, the rates of access patency in the low-pressure group were 68 and 48%, respectively; on the other hand, the primary patency rates in the high-pressure group were 86.67% (6-months) and 76.67% (12-months). The 6 and 12 months post-interventional patency rates were higher in patients of the high-pressure group than those in patients of the low-pressure group (p = 0.10 at 6 months and p = 0.03 at 12 months). CONCLUSIONS: Compared to balloon angioplasty using a low inflation pressure, hemodialysis patients with CVS/CVO receiving angioplasty using a high inflation pressure have significantly higher technical success and 12-month patency rates.

Pathophysiology and clinical implications of the veno-arterial PCO2 gap.

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2021. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2021 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901 .

Venous malformations.

The often inexorable growth and expansion of congenital vascular malformations can result in substantial morbidity and, in some cases, premature death of these patients. Despite this, patients suffering from such lesions are often erroneously diagnosed and/or inadequately treated, due to a lack of expertise among primary care practitioners as well as specialists. Venous malformations are the most common type of congenital vascular malformations. Over the last two decades management of these lesions has significantly improved, predominantly due to the introduction and implementation of multidisciplinary team concept as well as improvement in diagnostic and treatment modalities. Relatively recently genetic studies are providing more insights into underlying pathophysiological mechanisms responsible for the development and progression of venous malformations and pharmacotherapy is becoming extensively evaluated for safety and efficacy in the treatment of these often challenging vascular lesions.

Using Free Arterialized Venous Flaps for Reconstructing Hand Defects.

Hand and digit soft tissue defects are quite common and frequently require specialized reconstruction. When local flaps cannot be used to reconstruct a soft tissue defect, free flaps must be utilized. To overcome tissue volume and discrepancies in vessel diameter, arterialized venous free flaps from the forearm may provide an acceptable alternative. When using arterialized venous free flaps, surgeons should implement shunt restriction procedures to enhance flap viability.

Monitoring the Patient Following Radio-Cephalic Arteriovenous Fistula Creation: Current Perspectives.

Autogenous radial-cephalic direct wrist arteriovenous fistula (RC-AVF) in the non-dominant arm is the gold standard for dialysis vascular access. However, the RC-AVF non-maturation rate is significant (≃ 40%) due to an increasingly elderly and comorbid population incidence. A detailed identification of the biological cascade underlying arteriovenous fistula (AVF) maturation could be the key to clinical research aimed at identify the group of patients at risk of primary AVF failure. Currently, careful post-operative monitoring remains the most crucial aspect to overcome the problem of impaired maturation. Up to 80% of patients with immature RC-AVF have problems potentially solvable with early endovascular or surgical correction. Physical examination by experienced practitioners in conjunction with duplex ultrasound examination (DUS) can identify physical signs of non-maturation, understand the underlying cause, and drive for a tailored early planning to treat the complication. New approaches for the early assessment of AVF maturation are under study. Techniques to promote RC-AVF maturation performed through the administration of pre-or peri-operative drugs have missed up to now to prove an efficacy in improving fistula success. The new techniques tested after surgery appear to hold future promise for improving fistula maturation.

A Comparison of Outcomes Based on Vessel Type (Native Artery vs. Bypass Graft) and Artery Location (Below-Knee Artery vs. Non-Below-Knee Artery) Using a Combination of Multiple Endovascular Techniques for Acute Lower Limb Ischemia.

BACKGROUND: To evaluate outcomes of endovascular treatment (EVT) using a combination of multiple endovascular techniques for acute lower limb ischemia (ALLI) and to compare outcomes based on vessel type and artery location. METHODS: A total of 95 consecutive patients with ALLI (mean age, 72.0 years; 65 males; 104 lower limbs) who received emergency EVT using a combination of multiple endovascular techniques including thrombolysis, aspiration thrombectomy, stenting, and balloon angioplasty with or without surgical thromboembolectomy, between January 2005 and December 2017 were included. Vessel type was classified into native artery occlusion (native occlusion) and bypass graft occlusion (graft occlusion), including prosthetic and vein graft. Additionally, native arteries were categorized into below-knee occlusion and non-below-knee occlusion. Technical success, perioperative death (POD), ALLI-related death, amputation, amputation-free survival (AFS), and complications were compared according to vessel type (native occlusion vs. graft occlusion) and artery location (below-knee occlusion vs. non-below-knee occlusion). RESULTS: Of all patients with ALLI, 16.8% underwent a single endovascular technique, whereas 83.2% underwent a combination of multiple endovascular techniques. The technicalsuccess, POD, and ALLI-related death rates in the total number of patients were 94.7%, 11.6%, and 4.2%, respectively. A total of 67 patients (75 limbs) and 28 patients (29 limbs) were classified as having native occlusion and graft occlusion (prosthetic, 24 limbs; vein, 5 limbs), respectively. No significant differences in technical success (native occlusion: 92.5% vs. graft occlusion: 100%), POD (14.9% vs. 3.6%), and ALLI-related death (6.0% vs. 0%) were noted between native occlusion and graft occlusion. However, the 30-day AFS rate of native occlusion was significantly lower than that of graft occlusion (75.2% vs. 96.3%, P=0.01). The amputation rate (P=0.03) and AFS rate (P=0.03) of below-knee occlusion were significantly worse for below-knee occlusion patients than for non-below-knee occlusion patients. CONCLUSIONS: EVT using multiple endovascular techniques for ALLI is effective and safe. A combination of multiple endovascular techniques is crucial for successful treatment. However, native occlusion may have a lower AFS rate than graft occlusion, and below-knee occlusion may have a higher risk of amputation than non-below-knee occlusion.

Comparison of Outcomes for Open Popliteal Artery Aneurysm Repair Using Vein and Prosthetic Conduits.

BACKGROUND: Autologous vein is considered the preferred conduit for lower extremity bypass. There is, however, limited literature regarding conduit choice for open popliteal artery aneurysm (PAA) repair. We sought to compare outcomes of PAA repair using vein versus prosthetic conduits. METHODS: The Vascular Quality Initiative database (2003-2019) was queried for patients with PAAs undergoing elective conventional revascularization originating from the superficial femoral and popliteal arteries. Conduits were categorized as vein or prosthetic. Primary outcomes were primary graft patency, freedom from major adverse limb event (MALE) and MALE-free survival at 2-years. Kaplan-Meier method with log-rank tests was used for estimation and comparison of patency. RESULTS: A total of 1,146 limbs in 1,065 patients underwent elective open revascularization for PAA. Vein was used in 921 limbs (80%), and prosthetic in 225 (20%). Patients in the prosthetic cohort had a shorter procedure time, were older, and had a higher prevalence of COPD. Postoperatively, prosthetic patients were more likely to be started and maintained on anticoagulation without increased incidence of hematoma. There was no significant difference in the rate of surgical site infection (2% vs. 2%; P = 0.946). There was an increased tendency toward more symptomatic patients in the vein cohort although not statistically significant (49% vein vs. 41% prosthetic; P = 0.096). On a mean follow-up of 13 ± 5 months, the incidence of MALE and MALE-free survival were comparable between the two groups. The 2-year primary and secondary patency rates were similar, 87% and 96% in the vein, and 91% and 95% in the prosthetic groups, respectively. At multivariable analysis, outflow bypass targets to the infrapopliteal arteries (HR 2.05; 95% confidence interval (CI), 1.16-3.65; P = 0.014) and symptomatic aneurysm (HR 1.81; 95% CI, 1.04-3.15; P = 0.037) were independently associated with loss of primary patency. Conduit type did not make a difference in MALE-free survival, or primary graft patency at 2-years. CONCLUSION: Our study demonstrates that conventional open PAA repair with prosthetic conduit yields results comparable to those with vein conduit with regard to primary and secondary patency and MALEs at 2-years for targets to the popliteal artery. However, when the distal target was infrapopliteal, worse outcomes were observed with prosthetic conduit. Our results suggest that vein conduit should be preferentially used for infrapopliteal targets, while prosthetic conduit confers comparable outcomes in a subset of patients who do not have suitable autologous vein conduits.

Decreased Stroke Volume and Venous Return in School Children with Postural Tachycardia Syndrome.

In postural tachycardia syndrome (POTS), a subtype of orthostatic intolerance, the changes in hemodynamics due to postural changes are poorly understood. We speculated that inappropriate venous return, which may occur in the upright position in patients with school-aged POTS, could be detected by echocardiography. Our prospective study was conducted with 100 POTS patients (45 boys and 55 girls), aged 13.1 ± 1.5 years and 52 age- and sex-matched healthy subjects (control). Echocardiography was performed in the supine and sitting positions. Cardiac parameters [stroke volume index, cardiac index, heart rate, and the maximum inferior vena cava diameter (max IVC)] were evaluated in addition to pulse pressure. Unlike the control subjects, POTS patients demonstrated decreased stroke volume index (P = 0.02) and max IVC (P < 0.01) irrespective of posture. The rates of max IVC change did not differ between control and POTS groups. The enrolled POTS patients were divided into two subgroups [dilatation (n = 57) and contraction (n = 43)] based on whether the change rate of max IVC was less than zero or not. The contraction group showed a significantly higher heart rate than the dilatation group with respect to posture (P = 0.03), indicating the poor response of peripheral vessels in the lower limbs only in the contraction group. In conclusion, echocardiographic assessment detected decreased stroke volume and venous return in POTS. The changes in max IVC in response to postural changes may indicate an underlying pathophysiology in POTS.