Vein Conduit Research Articles

Axillary Vein to Superior Vena Cava Bypass: Femoral Vein Conduit Vs Synthetic Graft: Effective Treatment Options in a Low Resource Setting

Axillary Vein to Superior Vena Cava Bypass: Femoral Vein Conduit Vs Synthetic Graft: Effective Treatment Options in a Low Resource Setting

Heparin-Bonded Expanded Polytetrafluoroethylene Is a Solution for Infrapopliteal Revascularization in the Absence of an Adequate Autologous Vein Graft

To analyze the outcomes of heparin-bonded expanded polytetrafluoroethylene (HePTFE) graft as an alternative conduit in infrapopliteal revascularization of chronic limb-threatening ischemia (CLTI) in the absence of an autologous vein conduit. A single-center retrospective analysis of patients with CLTI submitted to infrapopliteal bypasses with autologous vein graft (VEIN group) or HePTFE graft (HePTFE group) was implemented. Primary end points were freedom from CLTI at 12months and recurrence of CLTI at 3years. Secondary end points included freedom from major amputation, amputation-free survival (AFS), survival, and primary (PP) and secondary patency (SP) rates at 3years of follow-up. A total of 348 limbs submitted to infrapopliteal bypasses, 214 with venous graft and 134 with HePTFE graft, were followed-up for a median of 25months. Most patients of the HePTFE group were male (69%), with a median age of 76years (interquartile range [IQR] 15). Fifty-nine percent of the limbs of the HePTFE group had Wound grade ≥2, being 46% of them infected. Eighty-eight percent were GLASS stage III. Freedom from CLTI was not significantly different between HePTFE and VEIN groups (75% vs. 84%, adjusted hazard ratio [aHR] 0.88, confidence interval [CI] 0.66-1.18, P=0.401). Recurrence of CLTI was higher in the HePTFE group (42% vs.18% at 3years; aHR 2.82, CI 1.59-5.00, P<0.001). The VEIN group achieved higher rates of freedom from major amputation (87% vs.69% at 3years; aHR 2.21, CI 1.31-3.75, P=0.003) and AFS (59% vs. 37% at 3years; aHR 1.39, CI 1.02-1.88, P=0.036), but no significance in survival (aHR 1.10, CI 0.72-1.66, P=0.667). Patency rates were inferior in the HePTFE group, with 2-year PP and SP rates of 52% vs. 74%, and 76% vs. 90%, respectively (PP: aHR 1.70, CI 1.11-2.59, P=0.014; SP: aHR 2.51, CI 1.42-4.42, P=0.001). Infrapopliteal bypass with autologous vein graft is the gold standard to treat CLTI limbs. HePTFE graft should be regarded as an alternative for complex infrapopliteal revascularization when lacking an autologous vein conduct.

Long-Term Outcomes After Right Ventricular Outflow Tract Conduit Placement

Objective: Our aim was to report on the long-term outcomes of patients who underwent RV-PA conduit placement at our institute. Materials and Methods: We retrospectively reviewed 407 RV-PA conduit placements from January 1997 to December 2018. The primary outcomes were freedom from and risk factor(s) for conduit re-operation. The secondary outcomes were survival, freedom from conduit dysfunction and conduit-related catheter intervention. Results: Of all the included patients, 209 were male (51.4%) and the median age at the operation was nine years (IQR 6, 18 years). The most commonly used conduit types were bovine jugular vein conduit (125, 30.7%), pulmonary homograft (122, 30.0%), and aortic homograft (76, 18.7%). The median follow-up time was 5.1 years (IQR 0.9, 9.2 years). The overall survival was 92.2% at 5 years. Freedom from re-operation was 95.4% and 84.2%, at 5 and 10 years. Factors related to conduit reoperation were age at operation less than 1 year, diagnosis rather than pulmonary atresia or stenosis, conduit size less than 18 mm, and conduit z-score greater than 3 (all p&lt;0.01). In multivariate analysis, a significant contributing factor for re-operation was small conduit size (13 mm or smaller; HR 6.87 (95%CI 2.36, 20.01); p&lt;0.001, 14–17 mm; HR 3.20 (95%CI 1.28, 8.00); p=0.013). Freedom from conduit dysfunction was 84.4% and 61.6% at 5 and 10 years. Freedom from conduit intervention was 94.4% and 89.3% at 5 and 10 years. Conclusion: Our study showed that patients had excellent survival with acceptable freedom from re-operation despite deteriorated conduit function. Small conduit size is associated with re-operation.

Predictors of Early Graft Thrombosis During Index Admission for Lower Extremity Arterial Bypass

Early graft thrombosis following lower extremity bypass (LEB) has long served as a quality indicator of surgical management. A granular understanding of the risk factors for graft thrombosis might help mitigate the potentially avoidable sequelae of this complication. Our study utilized Vascular Quality Initiative (VQI) data to identify predictor variables associated with graft thrombosis during index admission following LEB. We queried the VQI database for patients receiving unilateral infrainguinal LEB between 2003 and 2022. Patients undergoing concomitant PVI or suprainguinal bypass were excluded from our analysis. We formed six procedural groups: femoral-above knee popliteal bypass, femoral-below knee popliteal bypass, femoral-tibial bypass, femoral-ankle bypass, popliteal-tibial bypass, and popliteal-ankle bypass. Among these six groups, we utilized multivariable logistic regression modeling to identify technical and perioperative characteristics that predicted early graft thrombosis. Of the 54,504 LEB procedures that met inclusion criteria, 11,906 (21.8%) underwent femoral-above knee popliteal, 17,541 (32.2%) femoral-below knee popliteal, 19,224 (35.3%) femoral-tibial, 1414 (2.6%) femoral-ankle, 2661 (4.9%) popliteal-tibial, and 1758 (3.2%) popliteal-ankle bypass procedures. At the time of discharge, 1012 (1.9%) required intervention for a thrombotic intervention, and 814 (1.5%) were occluded. After adjusting for patient characteristics and comorbidities, we identified the following independent predictors for early graft thrombosis: female gender, distal target, symptomatic indication (rest pain and tissue loss), urgent/emergent presentation, and anticoagulation therapy, specifically warfarin and rivaroxaban. Conversely, the use of preoperative statin, aspirin and clopidogrel was protective against early graft thrombosis (Table). There were 9.5% of patients not receiving one or several of the protective medications identified (25.9% not receiving statins, 69.1% not receiving clopidogrel, and 27.6% not receiving aspirin). With regard to type of conduit used for LEB, native vein conduits demonstrated the lowest odds of graft thrombosis (Table, Figure). In this large national contemporary study of LEB, we have identified several factors including distal target, urgent/emergent presentation, preoperative warfarin or rivaroxaban therapy and use of nonautologous conduits as independent predictors of graft thrombosis. Conversely, preoperative statin, antiplatelet therapy and the use of native vein conduits were protective against graft thrombosis. Despite their beneficial effect, we identified that 9.5% of the LEB population are not receiving statin and/or antiplatelet therapies, which serves as a potential quality improvement initiative. Our findings suggest that utilization of native vein when possible, and promoting aggressive preoperative medical optimization including statin, aspirin and P2Y12 inhibitors may help avoid early graft occlusion in patients requiring lower extremity revascularization.TableMultivariable logistic regression model indicating technical and perioperative characteristics associated with early graft thrombosis after lower extremity arterial bypass surgeryPerioperative characteristicsOdds ratio (95% confidence interval)P valueAge0.99 (0.98-0.99)<.001Female sex1.32 (1.20-1.45)<.001White race1.10 (1.00-1.22).059Diabetes0.83 (0.75-0.92)<.001Dialysis1.02 (0.93-1.13).638Congestive heart failure1.03 (0.89-1.18).731Prior coronary artery bypass grafting0.87 (0.79-0.96).008Chronic obstructive pulmonary disease0.94 (0.83-1.05).266Smoking0.82 (0.73-0.93).002Aspirin0.73 (0.66-0.81)<.001Statin0.85 (0.77-0.95).003Baseline hemoglobin0.92 (0.90-0.95)<.001BMI1.00 (0.99-1.01).835Bypass type Femoral to above knee popliteal1 (reference)- Femoral to below knee popliteal1.62 (1.30-2.03)<.001 Femoral to tibial vessel3.18 (2.58-3.90)<.001 Femoral to ankle vessel4.41 (3.28-5.93)<.001 Popliteal to tibial vessel2.58 (1.98-3.37)<.001 Popliteal to ankle vessel3.15 (2.32-4.28)<.001Urgency Elective1 (reference)- Urgent1.74 (1.54-1.97)<.001 Emergent3.45 (2.75-4.34)<.001Conduit Native vein1 (reference)- Dacron1.09 (0.56-2.11).810 Polytetrafluoroethylene1.36 (1.20-1.55)<.001 Nonautologous biologic2.41 (1.95-2.97)<.001Indication Asymptomatic1 (reference)- Claudication1.02 (0.53-1.97).953 Rest Pain2.44 (1.28-4.66).007 Tissue loss2.18 (1.16-4.11).016 Acute ischemia3.39 (1.77-6.49)<.001 Not treated2.53 (1.34-4.77).004Per hour procedure time1.00 (1.00-1.00)<.001Preoperative P2Y12 antagonist therapy None1 (reference)- Clopidogrel0.81 (0.73-0.91)<.001 Prasugrel1.14 (0.58-2.24).697 Ticagrelor0.93 (0.49-1.75).818 Other0.81 (0.30-2.16).668 No, for medical reasons0.69 (0.50-0.96).027 Noncompliant1.35 (0.75-2.45).314Preoperative anticoagulation therapy None1 (reference)- Warfarin1.38 (1.16-1.65)<.001 Dabigatran1.06 (0.49-2.31).874 Rivaroxaban1.42 (1.15-1.75).001 Other1.54 (1.29-1.85)<.001 No, for medical reasons1.14 (0.74-1.74).548 Noncompliant2.35 (1.27-4.35).007Presented are odds ratios (95% confidence interval) from a multivariable model adjusting for age, sex, race, diabetes, dialysis, congestive heart failure, prior coronary artery bypass grafting, chronic obstructive pulmonary disease, smoking, use of aspirin, statin, anticoagulation, body mass index, urgency, indication, and total procedural time. Boldface entries indicate statistical significance. Open table in a new tab

Endovascular stenting for late-onset stricture of interposed portal vein conduit following pediatric liver transplantation

Endovascular stenting for late-onset stricture of interposed portal vein conduit following pediatric liver transplantation

Bovine jugular vein conduit replacement after homograft degeneration in patients with tetralogy of Fallot: The results of re-redo cases.

This study aims to present our experience and results in terms of reconstruction with bovine jugular vein conduit in re-redo patients who developed severe homograft degeneration with pulmonary homograft valve replacement. Between May 2018 and May 2021, a total of 10 re-redo patients (4 males, 6 females; mean age: 16.5±3.0 years; range, 12 to 21 years) who underwent bovine jugular vein conduit replacement due to homograft degeneration were retrospectively analyzed. The clinical, pre-, intra-, and postoperative data of the patients were recorded. The mean age of the second operation (homograft replacement) was 8.5±3.8 (range, 4 to 14) years in the patients who underwent homograft replacement. No postoperative mortality was observed. When the pre- and postoperative findings were compared, the right ventricular outflow tract gradient, the degree of pulmonary and tricuspid regurgitation, and right ventricular dilatation were regressed (p<0.05). A significant improvement in the New York Heart Association functional class was observed in all patients after surgery. After tetralogy of Fallot corrective surgery, repetitive surgical interventions are inevitable due to pulmonary valve deterioration. Therefore, a bovine jugular vein conduit may be a good alternative for conduit preference after pulmonary homograft failure in re-redo cases.

Pulmonary artery reconstruction using a pulmonary vein conduit in case having an imbalanced dissection length during double-sleeve lobectomy

BackgroundAmong the types of lung resection procedures, pneumonectomy carries the highest risk for mortality. In recent years, bronchovascular double-sleeve lobectomy has been performed for centrally located non-small cell lung cancer involving both the bronchus and the pulmonary artery (PA) in order to avoid pneumonectomy. The use of an autologous pulmonary vein (PV) conduit for PA reconstruction during lung-sparing resections had first been reported in 2009. Such situations may occur in cases requiring the resection of a long segment of the PA without associated bronchial sleeve resection.Case presentationWe experienced two cases who underwent PA reconstruction using a PV conduit after double-sleeve resection. In both cases, the tumor was located in the left upper lobe and invaded the long segment of the PA; however, it had not significantly invaded the bronchus. Our strategy for bronchovascular reconstruction involved the use of a PV conduit to avoid high tension on direct anastomosis given the imbalance in the excision length between the PA and the bronchus. The intraoperative and postoperative courses were uneventful, with both cases not receiving anticoagulant agents during the postoperative period. The reconstructed bronchus and PA functioned well during postoperative follow-up visits.ConclusionsFollowing sleeve resection, an autologous PV conduit may be indicated for PA reconstruction when an excessive distance exists between the two vascular stumps.

Recurrent Portal Vein Thrombosis In Liver Transplantation With Renoportal Anastomosis Caused by Spontaneous Reno-Caval Shunts: A Case Report

Orthotopic liver transplantation (OLT) in patients with cirrhosis complicated by portal hypertension, portosystemic shunts, and chronic portal vein thrombosis (PVT) has long been challenging. Spontaneous spleno-renal shunts (SRS) allow new surgical techniques to restore portal vein patency and hepatopetal flow. Renoportal anastomosis (RPA) has emerged as an accepted method for transplanting these patients, with good long-term patient and graft survival. Orthotopic liver transplantation with RPA is known to be complicated by recurrent PVT, with few details discussed in the literature. We present a case of a 56-year-old woman with decompensated cirrhosis who underwent deceased donor whole graft OLT using RPA with iliac vein conduit. The postoperative course was complicated by occlusive thrombosis in the portal vein and iliac vein conduit. Venography revealed enlarged left gonadal and lumbar vein varices acting as reno-caval shunts with hepatofugal flow. Embolization of the varices re-established durable venous patency that was confirmed on post-transplant day 68 with no other hemodynamic complications. This showcases an interesting mechanism by which recurrent PVT may occur in patients undergoing OLT with RPA. Because durable portal vein patency can be achieved with Interventional Radiology embolization of reno-caval varices, assessing these communications is an important preoperative consideration for planned OLT with RPA.

Contemporary outcomes for branch renal artery repair

BackgroundThe purpose of this study was to provide an updated description of demographics, technical details, and clinical outcomes of 101 consecutive branch renal artery repairs in 98 patients using cold perfusion. MethodsA single-institution, retrospective analysis branch renal artery reconstructions was performed between 1987 and 2019. ResultsPatients were predominantly Caucasian (80.6%) women (74.5%) with a mean age of 46.8 ± 15.3 years. The mean preoperative systolic and diastolic blood pressures were 170.4 ± 33.0 mm Hg and 99.2 ± 19.9 mm Hg, respectively, requiring a mean of 1.6 ± 1.1 antihypertensive medications. The estimated glomerular filtration rate was 84.0 ± 25.3 mL/min. Most patients (90.2%) were not diabetic and never smokers (68%). Treated pathology included aneurysm (87.4%) and stenosis (23.3%) with histology demonstrating fibromuscular dysplasia (44.4%), dissection (5.1%), and degenerative not otherwise specified (50.5%). The right renal arteries were most frequently treated (44.2%), with a mean of 3.1 ± 1.5 branches involved. Reconstruction was accomplished using bypass in 90.3% of cases using aortic inflow in 92.7% and a saphenous vein conduit in 92%. Branch vessels served as outflow in 96.9% and syndactylization of branches was used to decrease the number of distal anastomoses in 45.3% of repairs. The mean number of distal anastomoses was 1.5 ± 0.9. Postoperatively, the mean systolic blood pressure improved to 137.9 ± 20.8 mm Hg (mean decrease of 30.5 ± 32.8 mm Hg; P < .0001) and the mean diastolic blood pressure improved to 78.4 ± 12.7 mm Hg (mean decrease of 20.1 ± 20.7 mm Hg; P < .0001) with patients requiring a mean of 1.4 ± 1.0 antihypertensive medications (mean decrease of 0.2 ±1.0 medications; P = .048). The postoperative estimated glomerular filtration rate was 89.1 mL/min (mean increase of 4.1 mL/min; P = .08). The mean length of stay was 9.0 ± 5.8 days and 96.1% of patients were discharged home. The mortality rate was 1% (one patient with liver failure) and the major morbidity rate was 15%. There were five infectious complications (pneumonia, Clostridium difficile, and wound infection) and five patients required return to the operating room (one for nephrectomy, one for bleeding, two for thrombosis, and one for second trimester pregnancy loss requiring dilation and curettage and splenectomy). One patient required temporary dialysis owing to graft thrombosis. Two patients developed arrhythmias. No patients suffered a myocardial infarction, stroke, or limb loss. After 30 days, follow-up data were available for 82 bypasses. At this time, three reconstructions were no longer patent. Intervention was required to retain patency for five bypasses. After 1 year, patency data were available for 61 bypasses and five were no longer patent. Of the five grafts with loss of patency, two underwent intervention in attempt to maintain patency, which subsequently failed. ConclusionsRepair of renal artery pathology involving the branches can be performed with short- and long-term technical success and significant prospect of decreasing an elevated blood pressure. The operations required to fully address the presenting pathology are often quite complex involving multiple distal anastomoses and consolidation of small secondary branches. The procedure carries a small but significant risk of major morbidity and mortality.

Matched comparison of decellularized homografts and bovine jugular vein conduits for pulmonary valve replacement in congenital heart disease

For decades, bovine jugular vein conduits (BJV) and classic cryopreserved homografts have been the two most widely used options for pulmonary valve replacement (PVR) in congenital heart disease. More recently, decellularized pulmonary homografts (DPH) have provided an alternative avenue for PVR. Matched comparison of patients who received DPH for PVR with patients who received bovine jugular vein conduits (BJV) considering patient age group, type of heart defect, and previous procedures. 319 DPH patients were matched to 319 BJV patients; the mean age of BJV patients was 15.3 (SD 9.5) years versus 19.1 (12.4) years in DPH patients (p = 0.001). The mean conduit diameter was 24.5 (3.5) mm for DPH and 20.3 (2.5) mm for BJV (p < 0.001). There was no difference in survival rates between the two groups after 10 years (97.0 vs. 98.1%, p = 0.45). The rate of freedom from endocarditis was significantly lower for BJV patients (87.1 vs. 96.5%, p = 0.006). Freedom from explantation was significantly lower for BJV at 10 years (81.7 vs. 95.5%, p = 0.001) as well as freedom from any significant degeneration at 10 years (39.6 vs. 65.4%, p < 0.001). 140 Patients, matched for age, heart defect type, prior procedures, and conduit sizes of 20–22 mm (± 2 mm), were compared separately; mean age BJV 8.7 (4.9) and DPH 9.5 (7.3) years (p = n.s.). DPH showed 20% higher freedom from explantation and degeneration in this subgroup (p = 0.232). Decellularized pulmonary homografts exhibit superior 10-year results to bovine jugular vein conduits in PVR.

Routine Completion Angiography for Infrainguinal Bypasses Using Prosthetic Conduit: No Effect on Postoperative Patency

Recent studies have demonstrated increased postoperative patency with the use of routine completion angiography for bypass using venous conduit. Compared to vein conduits, however, prosthetic conduits are less plagued by technical issues such as unlysed valves or arteriovenous fistulae. The effect of routine completion angiography on bypass patency in prosthetic bypasses has yet to be compared to the more traditional selective use of completion imaging. A retrospective review of all infrainguinal bypass procedures using prosthetic conduit completed at a single hospital system from 2001 to 2018 was performed. Demographics, comorbidities, intraoperative reintervention rates, and 30-day rates of graft thrombosis were analyzed. Statistical analysis included t-tests, chi-square tests, and cox regression. Four hundred and ninety-eight bypasses that were performed in 426 patients met inclusion criteria. Fifty-six (11.2%) bypasses were classified into the routine completion angiogram group compared to 442 (88.8%) into the no completion angiogram group. Patients who underwent routine completion angiograms had a rate of intraoperative reintervention of 21.4%. When comparing bypasses that underwent routine completion angiography versus no completion angiography, there were no significant differences in rates of reintervention (3.5% vs. 4.5%, P=0.74) or graft occlusion (3.5% vs. 4.7%, P=0.69) at 30-days postoperatively. Almost one-quarter of lower extremity bypasses using prosthetic conduit that undergo routine completion angiography undergo postangiogram bypass revision; however, this is not associated with an increased graft patency at 30 days postoperatively.

Pro-inflammatory role of Wnt/β-catenin signaling in endothelial dysfunction.

Endothelial dysfunction is a critical component of both atherosclerotic plaque formation and saphenous vein graft failure. Crosstalk between the pro-inflammatory TNF-α-NFκB signaling axis and the canonical Wnt/β-catenin signaling pathway potentially plays an important role in regulating endothelial dysfunction, though the exact nature of this is not defined. In this study, cultured endothelial cells were challenged with TNF-α and the potential of a Wnt/β-catenin signaling inhibitor, iCRT-14, in reversing the adverse effects of TNF-α on endothelial physiology was evaluated. Treatment with iCRT-14 lowered nuclear and total NFκB protein levels, as well as expression of NFκB target genes, IL-8 and MCP-1. Inhibition of β-catenin activity with iCRT-14 suppressed TNF-α-induced monocyte adhesion and decreased VCAM-1 protein levels. Treatment with iCRT-14 also restored endothelial barrier function and increased levels of ZO-1 and focal adhesion-associated phospho-paxillin (Tyr118). Interestingly, inhibition of β-catenin with iCRT-14 enhanced platelet adhesion in cultured TNF-α-stimulated endothelial cells and in an ex vivo human saphenous vein model, most likely via elevating levels of membrane-tethered vWF. Wound healing was moderately retarded by iCRT-14; hence, inhibition of Wnt/β-catenin signaling may interfere with re-endothelialisation in grafted saphenous vein conduits. Inhibition of the Wnt/β-catenin signaling pathway with iCRT-14 significantly recovered normal endothelial function by decreasing inflammatory cytokine production, monocyte adhesion and endothelial permeability. However, treatment of cultured endothelial cells with iCRT-14 also exerted a pro-coagulatory and moderate anti-wound healing effect: these factors may affect the suitability of Wnt/β-catenin inhibition as a therapy for atherosclerosis and vein graft failure.

Infant Mitral Valve Replacement: Current State of the Art.

Mitral valve replacement (MVR) in the very young is an imposing clinical challenge. Early and late mortality risk is substantial, severe adverse events are common, and redo mitral valve replacement is inevitable. Therapeutic options are limited. In the older infant with an annulus of 17mm or larger, mechanical MVR is associated with low risk of mortality and predictable durability. For the very young with annular hypoplasia, bovine jugular vein conduit MVR appears to offer equivalent or better early outcomes with the possibility of subsequent valve expansion, potentially prolonging the interval to redo MVR. Experience with cylinder MVR and other forms of surgeon-manufactured MVR is quite limited, and there is currently no information on late outcomes or durability.

20-year follow-up and comparison of homografts with bovine jugular vein conduits in children less than 2 years of age.

Repair of congenital heart defects involving right ventricular outflow tract (RVOT) may require pulmonary valve replacement at time of primary repair or reoperation. This study compares the outcomes of cryopreserved homografts with bovine jugular vein conduits (BJVC) in children < 2 years of age with RVOT reconstruction. Retrospective, single-center review of 70 conduits implanted in 63 patients undergoing right ventricle-to-pulmonary artery reconstruction with valved conduit from 2002 to 2022. A total of 70 conduits were implanted in 63 patients, with mean age of 4.5 ± 6.9 months (range 1 day ‒ 23.5 months).The following conduits were used; homografts 38 (54.2 %), BJVC 32 (45.8 %). During mean follow-up of 6.2 ± 5.6 years, there were 12 deaths, 24 conduit reoperations, and 25 catheter reinterventions. Overall survival, reoperation-free, and catheter reintervention-free survival at 15 years was 82.7 %, 31.2 %, and 25.7 %, respectively. Multivariate analysis revealed that low patient weight, age < 30 days at repair, ventilation time, and ICU length of stay were associated with increased risk of death. The performance of homografts and BJVC is comparable in patients ent between the two groups (Tab. 3, Fig. 3, Ref. 16).

Diepoxy-treated bovine jugular vein conduit for pulmonary artery replacement

Objective: To evaluate the performance and short-term capacity of the diepoxy-treated bovine jugular vein conduit in large animals during 6-month follow-up.Methods: Thirteen diepoxy-treated bovine jugular vein conduits were implanted into the pulmonary artery of young mini-pigs. During the follow-up, graft function was tested using transesophageal echocardiography. The animals were withdrawn at 6 months, and the explanted conduits were assessed histologically.Results: All the conduits were successfully implanted without any surgical complications. All the animals survived throughout the follow-up. By the end of the follow-up period, the pressure gradient increased on five animals’ conduits including one case of mismatch between the conduit and the native pulmonary artery, two cases of distal stenosis, and two case of endocarditis. No significant increase in valve regurgitation or conduit thrombosis was observed during the follow-up. In conduits without dysfunction, the structure of the walls and leaflets was intact. A thin fibrous tissue covered the conduit inner wall with complete surface endothelialization. Neither signs of degeneration or calcification nor inflammatory cells were found in the conduit wall or leaflets. Neointima proliferation without calcium deposits was observed in two distally stenosed conduits. Inflammatory cells consisting of multinucleated macrophages, lymphocytes, and histiocytes were found in the adventitia. There were no inflammatory cells in the media or intima, and the leaflets showed no changes.Conclusion: Diepoxy-treated bovine jugular vein demonstrated acceptable performance, good endothelialization, and low tendency to thrombosis and calcium accumulation in the wall and leaflets. Received 31 October 2022. Revised 25 November 2022. Accepted 28 November 2022. Funding: The study was supported by Russian Science Foundation (grant No. 22-25-20102). Conflict of interest: The authors declare no conflict of interest. Contribution of the authorsConception and study design: N.R. Nichay, I.Yu. Zhuravleva, A.V. Bogachev-ProkophievData collection and analysis: N.R. Nichay, Yu.Yu. Kulyabin, I.S. Zykov, E.V. Boyarkin, O.Yu. Malakhova, E.V. Kuznetsova, T.P. Timchenko, Ya.L. Rusakova, I.S. Murashov, A.A. DokuchaevaStatistical analysis: N.R. Nichay, I.Yu. ZhuravlevaDrafting the article: N.R. Nichay, I.Yu. Zhuravleva, Yu.Yu. Kulyabin, I.S. Zykov, E.V. Boyarkin, O.Yu. Malakhova, T.P. Timchenko, Ya.L. Rusakova, I.S. Murashov, A.A. DokuchaevaCritical revision of the article: N.R. Nichay, I.Yu. Zhuravleva, Yu.Yu. Kulyabin, A.A. Dokuchaeva, A.V. Bogachev-ProkophievFinal approval of the version to be published: N.R. Nichay, I.Yu. Zhuravleva, Yu.Yu. Kulyabin, I.S. Zykov, E.V. Boyarkin, O.Yu. Malakhova, E.V. Kuznetsova, T.P. Timchenko, Ya.L. Rusakova, I.S. Murashov, A.A. Dokuchaeva, A.V. Bogachev-Prokophiev

Peripheral nerve regeneration in rats using nerve graft in a vein conduit pre-filled with platelet-rich fibrin (PRF)

Treatment of peripheral nerve injury is not always satisfactory. To improve results, specific adjuvant methods have been used, such as platelet-rich fibrin (PRF) and vein conduits. The goal of this study was to assess whether use of PRF and vein conduits after nerve suture improves nerve regeneration as measured by a functional score and histomorphometry analysis. Ten isogenic spontaneously hypertensive rats were randomly assigned to 4 experimental procedures: 1) Sham group (n = 10); 2) Nerve graft (NG) group (n = 10); 3) Nerve graft covered with a vein conduit (NGVC) (n = 10); and 4) Nerve graft covered with a vein conduit pre-filled with PRF (NGVCP) (n = 10). Nerve repair results were evaluated on: sciatic functional index (SFI) at 0, 30, 60 and 90 days; morphometric and morphologic analysis of the distal nerve; and histological analysis of Fluoro-Gold® stained motor neurons in the anterior horn of the spinal cord. Compared to the Sham control group, the NGVC and NGVCP groups exhibited lower SFI on all measures. The NGVC group showed improvement in SFI at day 90, which was significant compared to the NG group. Fiber and axon diameters were comparable in the NGVC and NGVCP groups, which were both significantly lower than in the Sham and NG groups. Significant improvement was expected with PRF, but in fact the release of factors from this substance was not as effective as hoped.

Does the Mode of Anaesthesia (General or Regional) Affect Survival and Complications Following Femoropopliteal and Femorodistal Bypass?

Femoropopliteal and femorodistal bypasses are indicated in the management of severe claudication or critical limb ischaemia. The choice of type of anaesthesia between generalanaesthesia (GA) and regionalanaesthesia (RA; epidural/spinal) has remained controversial. The study aimed tocompare the rates of graft failure, perioperative mortality,and other major complications (including graft failure) associated with GA versus RA for lower limb bypass revascularisation in patients presenting with significant peripheral arterial disease. All patients who had femoropopliteal and femorodistal bypass at the vascular unit of Colchester Hospital between January 2016 and September 2018 were included. The primary outcome measure was survival, and secondary outcome measures were respiratory, wound, cardiac, and graft failure complications. Technical success was defined as asuccessful operation with demonstrated graft patency at discharge and up to 30 days of follow-up. Secondary outcome measures included respiratory, wound, and cardiac complications. Statistical analysis included descriptive statistics and tests of association using chi-square for graft failure outcomes and the Mann-Whitney U test for the length of stay. All analyses were done at a 5% level of significance. There were 139 patients identified during the study period who fulfilled the inclusion criteria, of which 127 had complete records. The overall mortality and morbidity in this study were 1.6% and 14.229%, respectively. The proportion of patients who had ischaemic heart disease is almost threefold amongst those who had failed bypass compared to the successful bypass group (33.3% versus 11.9%, p = 0.018). A total of 65 patients received GA and 62 patients underwent RA; there were no significant differences in baseline preoperative comorbidities, postoperative mortality and complications, and length of stay. The majority (84%) of the patients who had RA had combined spinal and epidural (CSE) anaesthesia. The overall mortality and morbidity in this study were 1.6% and 14.2%, respectively. The proportion of patients with graft failure was 14.5% for GA versus 13.8% for RA (p = 0.914); there was no significant difference for conduit type, quality of vein conduit, the prevalence of heart failureand postoperative hypotensive episodes, redo-surgery, and major amputation, and length of stay (GA: 5.0, RA: 6.0, p = 0.854) did not differ significantly between the two groups.The proportion of patients who had ischaemic heart disease is almost threefold amongst those who had failed bypass compared to the successful bypass group (33.3% versus 11.9%, p = 0.018). The mode of anaesthesia, GA or the use of CSE RA in approximately half of the patients, did not influence survival, respiratory, cardiac, wound, graft failure, or length of stay in this study.There was a relationship between the presence of cardiac comorbidity and bypass failure, indicating a need for a standard care protocol to further optimise cardiac perioperative care to improve outcomes.

Surgery or Endovascular Therapy for Chronic Limb-Threatening Ischemia

BackgroundPatients with chronic limb-threatening ischemia (CLTI) require revascularization to improve limb perfusion and thereby limit the risk of amputation. It is uncertain whether an initial strategy of endovascular therapy or surgical revascularization for CLTI is superior for improving limb outcomes.MethodsIn this international, randomized trial, we enrolled 1830 patients with CLTI and infrainguinal peripheral artery disease in two parallel-cohort trials. Patients who had a single segment of great saphenous vein that could be used for surgery were assigned to cohort 1. Patients who needed an alternative bypass conduit were assigned to cohort 2. The primary outcome was a composite of a major adverse limb event — which was defined as amputation above the ankle or a major limb reintervention (a new bypass graft or graft revision, thrombectomy, or thrombolysis) — or death from any cause.ResultsIn cohort 1, after a median follow-up of 2.7 years, a primary-outcome event occurred in 302 of 709 patients (42.6%) in the surgical group and in 408 of 711 patients (57.4%) in the endovascular group (hazard ratio, 0.68; 95% confidence interval [CI], 0.59 to 0.79; P<0.001). In cohort 2, a primary-outcome event occurred in 83 of 194 patients (42.8%) in the surgical group and in 95 of 199 patients (47.7%) in the endovascular group (hazard ratio, 0.79; 95% CI, 0.58 to 1.06; P=0.12) after a median follow-up of 1.6 years. The incidence of adverse events was similar in the two groups in the two cohorts.ConclusionsAmong patients with CLTI who had an adequate great saphenous vein for surgical revascularization (cohort 1), the incidence of a major adverse limb event or death was significantly lower in the surgical group than in the endovascular group. Among the patients who lacked an adequate saphenous vein conduit (cohort 2), the outcomes in the two groups were similar. (Funded by the National Heart, Lung, and Blood Institute; BEST-CLI ClinicalTrials.gov number, NCT02060630.)

An efficient strategy to recellularization of a rat aorta scaffold: an optimized decellularization, detergent removal, and Apelin-13 immobilization

BackgroundTissue engineering of native vessels is an alternative approach for patients with vascular disease who lack sufficient saphenous vein or other suitable conduits for autologous vascular graft. Moreover, the harvest of vessels prolongs the surgical procedure and it may lead to the morbidity of donor site in elder patients: therefore, it seems that the use of tissue-engineered vessels would be an attractive and less invasive substitute for autologous vascular grafts. Apelin-13 plays a pivotal role in cell proliferation, survival, and attachment; therefore, covalent attachment of apelin-13 to the acellular scaffolds might be a favorable approach for improving recellularization efficacy.MethodsIn the present study, the decellularization process was performed using various detergents. Afterward, the efficacy of decellularization procedure was evaluated using multiple approaches including assessment of DNA, hydroxyproline, and GAG content as well as Masson’s trichrome and orcein staining used for collagen and elastin determination. Subsequently, the scaffold was bioconjugated with apelin-13 using the EDC-NHS linker and acellular scaffolds were recellularized using fibroblasts, endothelial cells, and smooth muscle cells. SEM images and characterization methods were also used to evaluate the effect of apelin-13 attachment to the acellular scaffold on tissue recellularization. We also developed a novel strategy to eliminate the remnant detergents from the scaffold and increase cell viability by incubating acellular scaffolds with Bio-Beads SM-2 resin. Testometric tensile testing machine was also used for the assessment of mechanical properties and uniaxial tensile strength of decellularized and recellularized vessels compared to that of native tissues.ResultsOur results proposed 16-h perfusion of 0.25% sodium dodecyl sulfate (SDS) + 0.5% Triton X-100 combination to the vessel as an optimal decellularization protocol in terms of cell elimination as well as extracellular matrix preservation. Furthermore, the results demonstrated considerable elevation of cell adhesion and proliferation in scaffolds bioconjugated with apelin-13. The immunohistochemical (IHC) staining of CD31, α-SMA, and vimentin markers suggested placement of seeded cells in the suitable sites and considerable elevation of cell attachment within the scaffolds bioconjugated with apelin-13 compared to the non-bioconjugated, and decellularized groups. Moreover, the quantitative analysis of IHC staining of CD31, α-SMA, and vimentin markers suggested considerable elevation in the number of endothelial, smooth muscle, and fibroblast cells in the recellularized scaffolds bioconjugated with apelin-13 group (1.4% ± 0.02, 6.66% ± 0.23, and 9.87% ± 0.13%, respectively) compared to the non-bioconjugated scaffolds (0.03% ± 0.01, 0.28% ± 0.01, and 1.2% ± 0.09%, respectively) and decellularized groups (0.03% ± 0.007, 0.05% ± 0.01, and 0.13% ±0.005%, respectively). Although the maximum strain to the rupture was reduced in tissues decellularized using 0.5% SDS and CHAPS compared to that of native ones (116% ± 6.79, 139.1% ± 3.24, and 164% ± 8.54%, respectively), ultimate stress was decreased in all decellularized and recellularized groups. Besides, our results indicated that cell viability on the 1st, 3rd, and 7th day was 100.79% ± 0.7, 100.34% ± 0.08, and 111.24% ± 1.7% for the decellularized rat aorta conjugated with apelin-13, which was incubated for 48-h with Bio-Beads SM-2, and 73.37% ± 7.99, 47.6% ± 11.69, and 27.3% ± 7.89% for decellularized rat aorta scaffolds conjugated with apelin-13 and washed 48-h by PBS, respectively. These findings reveal that the incubation of the scaffold with Bio-Beads SM-2 is a novel and promising approach for increasing cell viability and growth within the scaffold.ConclusionsIn conclusion, our results provide a platform in which xenograft vessels are decellularized properly in a short time, and the recellularization process is significantly improved after the bioconjugation of the acellular scaffold with apelin-13 in terms of cell adhesion and viability within the scaffold.Graphical

Decellularized bovine jugular vein and hand-sewn ePTFE valved conduit for right ventricular outflow tract reconstruction in children undergoing Ross procedure.

BackgroundThe Ross procedure is recommended as an optimal aortic valve replacement (AVR) in children and young adults due to several advantages. Nevertheless, multiple reconstructions of the right ventricular outflow tract (RVOT) with new valve conduits have caused some concern regarding the durability of the Ross AVR. Decellularized bovine jugular vein conduit (BJVC) (DP-BJVC) and hand-sewn expanded polytetrafluoroethylene valved conduits (ePTFE VC) are widely employed to reconstruct the RVOT with satisfactory long-term outcomes. However, few studies have compared the safety and efficacy between the two valve conduits. We aimed to evaluate the early outcomes and report our single center experience in the application of these conduits.MethodsTwenty-two pediatric patients (aged < 18 years) who underwent Ross procedures with DP-BJVC and ePTFE VC in our center between 1 June, 2017 and 31 January, 2022 were enrolled. The Kaplan–Meier method was used to evaluate survival, freedom from RVOT reintervention, and freedom from RVOT graft dysfunction. Mixed-effects analysis with the Geisser–Greenhouse correction and Sidak's multiple comparisons test for post-hoc analysis was employed to compare the peak gradient across the conduit at varying follow-ups.ResultsAll patients were followed up in full. The total early survival rate was 90.9%; two patients in the DP-BJVC group died. There was no significant difference in early mortality, cross-clamp time (p = 0.212), in-hospital stay (p = 0.469), and RVOT graft thrombosis or endocarditis between the two groups. There was similarly no significant difference between Kaplan–Meier freedom from RVOT graft dysfunction curve (P = 0.131). The transprosthetic gradient gradually increased over time in both groups and was significantly higher in the DP-BJVC group at follow-up (P < 0.05).ConclusionsBoth conduits show excellent early and midterm outcomes for RVOT reconstruction in the Ross procedure. We suggest that DP-BJVC is more suitable for infants, and ePTFE conduit is more suitable for older children who require larger conduits.