Significant Difference In Patency Rates Research Articles

Comparative evaluation of double- and single-armed two-suture longitudinal intussusception techniques in microsurgical vasoepididymostomy: An updated systematic review and meta-analysis.

This study aimed to compare the outcomes of double-armed two-suture longitudinal intussusception microsurgical vasoepididymostomy (LIVE) and single-armed two-suture LIVE techniques in patients with epididymal obstructive azoospermia (EOA). The main outcomes assessed were patency rates, patency time, semen quality and natural pregnancy rates. Data from patients with EOA who underwent two-suture LIVE were obtained from databases including PubMed, EMBASE, and Web of Science. Weighted data were analyzed using a random-effects model, and weighted mean differences were reported. A total of 1574 patients with EOA from 24 studies were included. The overall patency rate was approximately 68% (95% confidence interval [CI]: 63-72%), with a patency time of approximately 4.63 months (95% CI: 4.15-5.12). The sperm concentration reached 26.90 million/ml and the sperm motility was 23.74%. The natural pregnancy rate was 38% (95% CI: 31-46%). The different definitions of patency do not seem to have any meaningful impact when comparing patency rates. There was no significant difference in patency rates, patency time, semen quality and natural pregnancy rates between the double-armed and single-armed LIVE techniques. The single-armed LIVE is a potential alternative surgical option when high quality double-needle sutures are not easily accessible.

Effectiveness of intra-arterial manometry in guiding femoral popliteal stent implantation: a prospective randomized controlled trial.

Femoropopliteal artery occlusion is a prevalent peripheral arterial disease, and endovascular therapy has become the preferred treatment. Accurate assessment of balloon dilation efficacy is crucial for determining the necessity for subsequent stent implantation. This study aims to investigate the use of interlesion arterial pressure gradients as a novel approach to assess balloon dilation efficacy and guide stent implantation decisions. A prospective, randomized, controlled trial was conducted on 100 patients with femoropopliteal artery occlusion. Patients were randomized into a control group (n=50) and an experimental group (n=50). Stent implantation was performed in the control group according to standard indications, while the experimental group underwent stent implantation only if the mean arterial pressure gradient exceeded 10 mmHg or fractional flow reserve (FFR) fell below 0.85. Post-intervention, pressure measurements and angiography were used to evaluate residual stenosis, dissection, and pressure gradients. Lesions were categorized into stent-indicated and non-indicated groups. In the non-stent-indicated lesions, the experimental group demonstrated significantly higher patency rates for lesions with pFFR < 0.85 or ΔP > 10 mmHg compared to the control group (92.9% vs. 50.0%, P=0.039). There was no significant difference in patency rates between the experimental and control groups for stent-indicated lesions. Combining pressure measurement with angiography provides a more precise evaluation of balloon dilation efficacy and stent implantation indicators in femoropopliteal artery occlusive disease. Further research is needed to establish optimal pressure threshold values and refine treatment guidelines.

A randomized controlled trial of indobufen versus aspirin in the prevention of bridging restenosis after coronary artery bypass grafting

Objective: To compare the efficacy and safety between indobufen and aspirin in the prevention of restenosis of bridge vessels at 1 year after off-pump coronary artery bypass grafting. Methods: This study was a prospective cohort study. We selected 152 patients who received coronary artery bypass grafting in Beijing Anzhen Hospital from December 2016 to December 2018. Patients were divided into the indobufen group and the aspirin group. Patients in the aspirin group were treated with aspirin and clopidogrel, and patients in the indobufen group were treated with indobufen and clopidogrel. During the 1-year follow-up, the rate of restenosis of saphenous vein bridge and internal mammary artery bridge, the rate of adverse cardiac events and adverse reactions were compared between the two groups. The levels of fibrinogen (FIB), D-dimer (D-D), thrombomodulin (TM) and thrombin-activatable fibrinolysis inhibitor (TAFI) were compared before and after antiplatelet therapy. Results: There were 76 cases in the indobufen group, including 57 males (75.0%), aged (60.3±6.6) years. There were 76 cases in the aspirin group, including 62 males (81.6%), aged (59.7±7.2) years. Baseline data were comparable between the two groups (P>0.05). During the follow-up, 3 cases were lost to follow up. Follow-up was completed in 74 patients in the indobufen group and 75 in the aspirin group. A total of 268 bridging vessels were grafted in the indobufen group and 272 in the aspirin group. One year after surgery, the patency rates of great saphenous vein bridge and internal mammary artery bridge were 94.5% (189/200) and 97.1% (66/68) in the indobuphen group, and 91.3% (189/207) and 96.9% (63/65) in the aspirin group, respectively. There was no significant difference in patency rate of great saphenous vein bridge and internal mammary artery bridge between the two groups (χ²=0.282, 0.345, P>0.05). The total incidence of adverse cardiac events was 5.4% (4/74) in the indobufen group and 6.7% (5/75) in the aspirin group (χ²=0.126, P>0.05). The overall incidence of gastrointestinal adverse reactions was significantly lower in the indobufen group than in the aspirin group (4.1% (3/74) vs. 13.3% (10/75), χ²=4.547, P<0.05). The levels of FIB, D-D, TM and TAFI in the two groups were lower than those before surgery (P<0.05), and there was no statistical significance between the two groups at baseline and post-operation (P>0.05). Conclusion: The efficacy of indobufen combined with clopidogrel in the prevention of 1-year restenosis after coronary artery bypass graft is similar to that of aspirin combined with clopidogrel, but the incidence of adverse reactions is lower, and the safety is higher in patients treated with indobufen combined with clopidogrel compared to aspirin combined with clopidogrel strategy.

To Close, Observe, or Reconstruct: The Third Way of Managing Dialysis Fistula Aneurysms in Kidney Transplant Recipients.

Background: The management of patent dialysis fistulas in patients after kidney transplantation (KTx) is controversial—the options that are usually considered are the fistula’s closure or observation. Many complications of dialysis fistulas occur in patients after KTx, and immunosuppression increases the risk of fistula aneurysms and hyperkinetic flow. This study aimed to evaluate the results of dialysis fistula aneurysm treatment in patients after KTx and to compare them to procedures performed in an end-stage renal disease (ESRD) dialyzed population. Methods: We enrolled 83 renal transplant recipients and 123 ESRD patients with dialysis fistula aneurysms qualified for surgical revision to this single-center, prospective study. The results of the surgical treatment of dialysis fistula aneurysms were analyzed, and the primary, assisted primary and secondary patency rate, percentage and type of complications were also assessed. Results: For the treatment of dialysis fistula aneurysms in transplant patients, we performed dialysis fistula excisions with fistula closure in 50 patients (60.2%), excision with primary fistula reconstruction (n = 10, 12.0%) or excision with PTFE bypasses (n = 23, 27.7%). Postoperative complications occurred in 11 patients (13.3%) during a follow-up (median follow-up, 36 months), mostly in distant periods (median time after correction procedure, 11.7 months). The most common complication was outflow stenosis, followed by hematoma, dialysis fistula thrombosis and the formation of a new aneurysm and postoperative bleeding, infection and lymphocele. The 12-month primary, primary assisted and secondary patency rates of fistulas corrected by aneurysm excision and primary reconstruction in the KTx group were all 100%; in the control ESRD group, the 12-month primary rate was 70%, and the primary assisted and secondary patency rates were 100%. The 12-month primary, primarily assisted and secondary patency rates after dialysis fistula aneurysm excision combined with PTFE bypass were better in the KTx group than in the control ESRD group (85% vs. 71.8%, 90% vs. 84.5% and 95% vs. 91.7%, respectively). Kaplan–Meier analysis showed a significant difference in primary patency (p = 0.018) and assisted primary (p = 0.018) rates and a strong tendency in secondary patency rates (p = 0.053) between the KTx and ESRD groups after dialysis fistula excisions combined with PTFE bypass. No statistically significant differences in patency rates between fistulas treated by primary reconstruction and reconstructed with PTFE bypass were observed in KTx patients. Conclusions: Reconstructions of dialysis fistula aneurysms give good long-term results, with a low risk of complications. The reconstruction of dialysis fistulas can be an effective treatment method. Thus, this is an attractive option in addition to fistula ligation or observation in patients after KTx. Reconstructions of dialysis fistula aneurysms enable the preservation of the dialysis fistula while reducing various complications.

CCL2 loaded microparticles promote acute patency in silk-based vascular grafts implanted in rat aortae

Cardiovascular disease is the leading cause of death worldwide, often associated with coronary artery occlusion. A common intervention for arterial blockage utilizes a vascular graft to bypass the diseased artery and restore downstream blood flow; however, current clinical options exhibit high long-term failure rates. Our goal was to develop an off-the-shelf tissue-engineered vascular graft capable of delivering a biological payload based on the monocyte recruitment factor C-C motif chemokine ligand 2 (CCL2) to induce remodeling. Bi-layered silk scaffolds consisting of an inner porous and outer electrospun layer were fabricated using a custom blend of Antherea Assama and Bombyx Mori silk (lyogel). Lyogel silk scaffolds alone (LG), and lyogel silk scaffolds containing microparticles (LGMP) were tested. The microparticles (MPs) were loaded with either CCL2 (LGMP+) or water (LGMP-). Scaffolds were implanted as abdominal aortic interposition grafts in Lewis rats for 1 and 8 weeks. 1-week implants exhibited patency rates of 50% (7/14), 100% (10/10), and 100% (5/5) in the LGMP-, LGMP+, and LG groups, respectively. The significantly higher patency rate for the LGMP+ group compared to the LGMP- group (p = 0.0188) suggests that CCL2 can prevent acute occlusion. Immunostaining of the explants revealed a significantly higher density of macrophages (CD68+ cells) within the outer vs. inner layer of LGMP- and LGMP+ constructs but not in LG constructs. After 8 weeks, there were no significant differences in patency rates between groups. All patent scaffolds at 8 weeks showed signs of remodeling; however, stenosis was observed within the majority of explants. This study demonstrated the successful fabrication of a custom blended silk scaffold functionalized with cell-mimicking microparticles to facilitate controlled delivery of a biological payload improving their in vivo performance. Statement of significanceThis study outlines the development of a custom blended silk-based tissue–engineered vascular graft (TEVG) for use in arterial bypass or replacement surgery. A custom mixture of silk was formulated to improve biocompatibility and cellular binding to the tubular scaffold. Many current approaches to TEVGs include cells that encourage graft cellularization and remodeling; however, our technology incorporates a microparticle based delivery platform capable of delivering bioactive molecules that can mimic the function of seeded cells. In this study, we load the TEVGs with microparticles containing a monocyte attractant and demonstrate improved performance in terms of unobstructed blood flow versus blank microparticles. The acellular nature of this technology potentially reduces risk, increases reproducibility, and results in a more cost-effective graft when compared to cell-based options.

Relationship between Monocytes and Stenosis-Related Autologous Arteriovenous Fistula Dysfunction

Background: Arteriovenous fistula (AVF) is considered to be the best choice of vascular access, but the maturation rate and patency rate of AVF are not satisfactory. Many studies have explored the influencing factors of AVF failure but do not involve the direct relationship between monocyte count and AVF failure. This study aims to explore the relationship between monocyte count and AVF dysfunction related to stenosis. Methods: From September 2017 to September 2018, basic clinical data and laboratory parameters of patients were collected. All included patients were followed up to September 2019. The stenosis-related AVF failure events that occurred after the patient included in the study and the time of their occurrence were recorded. All patients were divided into 3 groups based on the tertile of monocyte count. Kaplan-Meier method was used to compare the patency rate of AVF in each group. The effects of variables on AVF failure were analyzed. A multivariate Cox regression model with p < 0.05 was included in the univariate Cox regression analysis. Results: A total of 120 patients were included in this study. According to the recorded baseline monocyte count levels, they were divided into 3 groups according to their tertiles, 34 cases in the T1 group (T1 < 0.32 × 109/L), 44 cases in the T2 group (0.32 ≤ T2 < 0.51 × 109/L), and 42 cases in T3 group (T3 ≥0.51 × 109/L). After a median follow-up of 20 months, a total of 31 AVF failure events occurred. Kaplan-Meier survival curves showed that patients with a baseline monocyte count ≥0.51 × 109/L had the lowest patency rate of AVF (log-rank test χ2 = 7.525, p = 0.023). After adjusting to basic clinical data and biochemical indicators, there were statistically significant differences in patency rates of the 3 groups (hazard ratio = 2.774, 95% CI = 1.092–7.043). Conclusion: Monocyte count ≥0.51 × 109/L is an independent risk factor for AVF failure, and AVF failure caused by monocytes may be driven by inflammation.

Multiple Skin Bridging for No-Touch Saphenous-Vein Grafts Harvesting Can Reduce Wound Morbidity.

Reducing the leg wound morbidity is crucial for the patients undergoing coronary artery bypass grafting (CABG) with great saphenous vein (SV) grafts harvested by no-touch (NT) technique. This study was to summarize the experience of skin bridging technique for reducing wound morbidity and the influence of it on one-year bypass graft patency. According to skin bridging or not, harvesting times, graft length, number of bleeding branches, postoperative subjective perception assessment scale (ASEPSIS) scores and one-year patency rate were analyzed. From June 2018 to February 2019, 60 patients underwent CABG with SV grafts either with open-incision NT or skin bridging NT (30 in each group). There were no significant differences in age (71.4 ± 5.1 years vs. 68.9 ± 5.5 years) or graft length (23.3 ± 1.1 cm vs. 23.9 ± 1.3 cm) between the two groups. The bridging/NT group had a significantly longer harvest time (38.5 ± 4.9 min vs. 18.5 ± 2.6 min; P < 0.001) and a significantly greater number of bleeding branches (1.9 ± 1.2 vs. 0.8 ± 0.8; P < 0.001) than the open NT group. The open NT group had a significantly higher ASEPSIS score (23.8 ± 2.0 vs. 15.7 ± 2.6; P < 0.001). There was no significant difference in patency rate at one-year follow-up. Obtaining the SV by the combined NT/discontinuous skin bridging technique is a satisfactory method for patients who underwent CABG. This method has important clinical significance in reducing wound morbidity in the harvest of NT grafts.

Implanted blood vessel external support device (VasQ™) for creation of hemodialysis arteriovenous fistula: A single-center experience.

the external support device VasQ is intended to promote arteriovenous fistula (AVF) maturation by maintaining the optimal anastomotic angle in order to minimize blood flow disturbances around the anastomotic area. The aim of the study is to assess efficacy and safety of the VasQ device both in brachiocephalic and radiocephalic fistulae. a single institution prospective study was conducted with implantation of the VasQ device during AVF creation. Clinical and Doppler ultrasounds evaluations were performed at day-1, 1, 6, and 12 months for assessment of device-related adverse events, AVF maturation and patency. Moreover, volume flow rate and diameter of outflow vein were measured. A total of 16 patients were enrolled. Ten brachiocephalic and 6 radiocephalic AVFs were created with VasQ. Preoperatively cephalic vein diameter was 3.6 ± 0.9 mm. our population included 13 male and 3 females patients, 9 end stage kidney disease in conservative therapy, 4 dialysis treated patients, and 3 transplanted patients; mean age was 74.0 ± 8.1 years; no severe device-related adverse events were observed. Primary patency at 1, 6, and 12 months was 100%, 87.5%, and 67.7%, respectively, while secondary patency was 100%, 100%, and 78.3%, respectively. Comparing brachiocephalic to radiocephalic AVFs no significant differences in patency rates were seen. Overall maturation rate was 94% (15/16). Mean vein diameter measured with Doppler ultrasound at postoperative day-1 and at 1, 6, and 12 months was 5.0 ± 1.0, 5.9 ± 0.9, 7.2 ± 1.6, and 7.9 ± 1.4 mm, respectively, with a mean flow rate at the brachial artery of 841 ± 176, 1052 ± 224, 1261 ± 490, and 1348 ± 477 ml/min, respectively. in our limited experience VasQ was safe, with high maturation and patency rates. Positive results suggest a potential benefit for VasQ in AVF.

Predictive Value of 1-Week Postoperative Ultrasonography Findings for the Patency Rate of Arteriovenous Fistula

IntroductionMost guidelines in different countries recommend waiting more than 2 weeks for the initial cannulation of an arteriovenous fistula (AVF) after its creation. Although an experienced examiner can subjectively determine if an AVF is ready for early cannulation, there is a lack of objective information to guide whether early cannulation is appropriate or how early cannulation may affect an AVF’s primary patency. The current study examined the relationship between the initial cannulation and the prognosis of AVF, considering ultrasonography (US) findings.MethodsThis retrospective observational study enrolled 103 patients with end-stage renal disease who had started hemodialysis therapy from 2013 to 2015 at the Juntendo University Hospital. All patients had been given a primary AVF before or after the initiation of dialysis, had undergone US examinations both before and 7 days after surgery, had initially cannulated the AVF at ≥7 days after surgery, and were observed for over 1 year.ResultsThe factor associated with the loss of primary patency was a resistance index of brachial artery ≥0.65 on US examination at 7 days after surgery. There was no significant difference in patency rate between the early (within 14 days after surgery) and late initial cannulation groups (≥15 days after surgery).ConclusionBecause a resistance index <0.65 on US findings at 7 days after surgery was a good indicator for predicting an excellent patency rate when we performed first cannulation of AVF located in the forearm within 2 weeks after its creation, 1-week postoperative US evaluation may provide crucial information.

P1315PREDICTABILITY OF SONOGRAPHICALLY DETERMINED IMMEDIATE POST-OPERATIVE BLOODFLOW AND VEIN DIAMETER ON PRIMARY RADIOCEPHALIC FISTULA SHORT AND LONGTERM OUTCOMES

Abstract Background and Aims Vascular access (VA) guidelines recommend radio-cephalic (RC) over upper arm autogenous arteriovenous fistulas (AVF) as first line VA for hemodialysis in end stage renal disease (ESRD) patients. RCAVFs generally have inferior maturation and patency rates predicated on a lower feeding arterial blood flow (BF) and outflow vein calibre (VC). However studies on postoperative BF and VC as predictors of AVF outcomes, so far are confounded by their focus on early outcomes only, heterogeneity of AVFs studied, variable timing of assessment and use of non-standardised outcome definitions. Our aim was therefore to assess the accuracy and influence of immediate post-operative BF and VC on both early and longterm outcomes in a homogenous cohort of primary RCAVFs using standardised definitions and outcome measures as mandated by VA guidelines. Method This was a prospective study conducted in multi-ethnic Asian ESRD patients who had their primary RCAVFs created between October 2013 and October 2014 under regional anesthesia at Khoo Teck Puat hospital Singapore. All AVFs were assessed immediately after surgery for brachial artery BF and outflow VC using doppler ultrasound. A 10MHz linear probe and GE Logic e R7 machine were used exclusively by a single operator. Receiver operating characteristic (ROC) curves were generated to determine the optimal BF and VC cut-off for AVF maturation. Maturation was defined as BF&amp;gt;600mL/min, VC&amp;gt;6mm and vein depth &amp;lt;6mm at 6 weeks post-op. An area under the curve (AUC)&amp;gt; 0.7 was considered clinically significant. Kaplan–Meier analysis was used to evaluate the AVF primary and secondary patency based on best BF and VC cut-offs. Cox regression statistics was used to determine AVF hazard factors. Results Fifty-seven primary RCAVFs were created and included in the study. The baseline characteristics are shown in Table 1. Sonography- based non-assisted maturation at 6 weeks was 56%. ROC identified 410 mL/min and 42mm as the best BF and VC cut-off respectively to most accurately predict 6-week maturation. The sensitivity, specificity, positive predictive value and negative predictive value were 75%, 61%, 44% and 86% for BF at 410 mL/min and 69%, 61%, 41% and 83% for VC at 42mm respectively. Survival analysis (Fig. 1 and 2) showed that AVFs with VC≥42 mm compared to &amp;lt;42mm had significantly greater 6 months, 1-year, 2-year and 4-year primary and secondary patency rates. There was no significant difference in patency rates between AVFs with BF≥410 and &amp;lt;410mL/min. Cox proportional regression hazard analysis showed that diabetes (HR 2.26, CI 1.02-4.99, p= 0.04) and maturation (HR 0.47, 95% CJ 0.24-0.89, p=0.02) as significant contributed to the variability of primary patency. Only VC (HR 0.28, 95% CI 0.13-0.063, p=0.002) impacted significantly towards secondary patency. Conclusion An immediate post-op BF≥410mL/min and VC≥42mm can predict early RCAVF outcome in the form of nonassisted maturation, but only VC accurately impact on longterm AVF survival. VA surveillance efforts should therefore target RCAVFs with post-op VC &amp;lt;42mm for timely intervention and maintenance of longterm patency.

Evolving strategies for the management of venous thoracic outlet syndrome

ObjectiveTraditional management of venous thoracic outlet syndrome (VTOS) has involved catheter-directed thrombolysis (CDT) followed by transaxillary or paraclavicular (PC) first rib resection. More recently, we have adopted an infraclavicular (IC) approach for first rib resection and five other strategies to treat these patients. We report our evolving experience with the treatment of acute VTOS. MethodsWe reviewed our prospectively maintained database to identify patients treated for VTOS. Our strategy includes CDT with pharmacomechanical thrombectomy, IC first rib resection during the same hospitalization, and subclavian vein angioplasty immediately after rib resection. Postoperatively, a sequential compression device was applied to the affected arm and low-dose heparin given through the ipsilateral venous sheath. Antiplatelet therapy was given for 6 weeks and anticoagulation for 6 months. Our strategy evolved from a PC to an IC approach, given that the added morbidity of the supraclavicular approach to allow excision of the posterior portion of the rib may add no benefit with VTOS compared with arterial or neurogenic thoracic outlet syndrome. ResultsThere were 51 patients who underwent first rib resection for VTOS, 11 (22%) through a PC approach and 40 (78%) through an IC approach. The average age was 36 years (range, 16-63 years), and the majority were female (36 [71%]) and involved the right subclavian vein (36 [71%]). All patients underwent preoperative CDT, 40 (78%) at our hospital and 11 (22%) elsewhere. Fifty patients (98%) underwent subclavian vein angioplasty after rib resection. A bare-metal stent was placed in two (4%) patients for persistent stenosis. Average length of stay was 3.7 (±2.1) days. Average operative time was 2.2 hours (range, 1.5-3.0 hours) when the IC approach was used vs 3.5 hours (range, 2.5-4.5 hours) for the PC approach (P < .0001). Of the entire group, one (2.6%) patient required reoperation for wound hematoma and six (12%) patients underwent repeated endovascular intervention for recurrent vein stenosis during follow-up (average, 38 months; range, 1-240 months). Primary and assisted primary patency rates at 3 years were 78% and 100%, respectively. There were no significant differences in patency rates or complications between the IC and PC approaches. ConclusionsOur transition to an IC approach demonstrated low perioperative morbidity and excellent subclavian vein patency rates with shorter operative times compared with a PC approach. Our practice has evolved to include IC first rib resection followed by concomitant postoperative venous balloon angioplasty.

Drug-Coated Balloon Angioplasty in Hemodialysis Circuits: A Systematic Review and Meta-Analysis

PurposeTo perform a systematic review and meta-analysis assessing patency outcomes following drug-coated balloon angioplasty (DCBA) in hemodialysis circuits. Materials and MethodsMEDLINE and EMBASE systematic searches were performed from inception to November 2018 to identify comparative studies assessing DCBA vs plain old balloon angioplasty (POBA) in hemodialysis circuits. Abstract selection, data extraction, and quality assessment were performed by 2 independent reviewers. Primary outcome was loss of target lesion patency at 3, 6, 12, and 24 months for autogenous arteriovenous fistula (AVF), prosthetic arteriovenous graft (AVG), and hemodialysis-related central venous stenosis. ResultsTwelve studies comprising 908 patients were included. There was a significant improvement in patency among AVF after DCBA vs POBA at 3, 6, 12, and 24 months (odds ratio 0.58 [95% confidence interval, 0.36–0.94]; odds ratio 0.40 [95% confidence interval 0.23–0.70]; odds ratio 0.39 [95% confidence interval, 0.25–0.61]; and odds ratio 0.20 [95% confidence interval, 0.07–0.62]). This benefit persisted on subgroup analysis of randomized controlled trials (RCTs) only. Meta-analysis of results specific to AVG could not be performed, as only 1 RCT was identified that favored DCBA. Hemodialysis-associated central vein stenosis did not demonstrate a significant difference in patency rates between DCBA and POBA on meta-analysis. Twelve-month mortality and same-day complication rates did not differ between arms. ConclusionsSignificant improvement in patency was identified with DCBA in AVF at 3, 6, 12, and 24 months. A single comparative study identified benefit of DCBA use in the AVG group. No significant benefit was identified with DCBA for central stenosis.

Robot-assisted microsurgical vasovasostomy: the learning curve for a pure microsurgeon

Vasovasostomy success rates improved with the application of the operative microscope in 1975. The robotic platform offers potential advantages including: a stable, ergonomic, scalable control system with three-dimensional visualization and magnification, the elimination of physiological tremor, and simultaneous control of three instruments and a camera. A previous publication revealed a fellowship-trained microsurgeon (PKK) could transition to robot-assisted microsurgical vasovasostomy (RAVV) with comparable outcomes. The objective of this current study was to evaluate the learning curve for the purely trained microsurgeon transitioning to RAVV. A retrospective chart review was performed of a microsurgeon’s first 100 RAVVs evaluating the learning curve for patency rates, anastomosis times, operative times, and sperm concentrations at the initial postoperative semen analyses. Cases were stratified into four groups by 25 case intervals. There were no statistically significant differences in patency rates or postoperative sperm concentrations between the groups over time. There were differences in anastomosis times between groups 1 and 2, as well as between groups 2 and 3, and there were differences in operative times between groups 2 and 3. High-percentage patency rates are achievable very early in the transition from pure microsurgical vasovasostomy to RAVV across wide ranges of obstructive intervals. Postoperative mean sperm concentrations in the initial semen analyses after RAVV are consistent over time. For a single microsurgeon not formally trained in robotic microsurgery, 75 RAVV cases were required to optimize and plateau in anastomosis times and 75 cases were required to optimize operative times.

Cerebral revascularization for the management of complex intracranial aneurysms: a single-center experience.

Because simple intracranial aneurysms (IAs) are increasingly treated endovascularly, neurovascular surgery has become focused on complex IAs that may require deconstructive aneurysm therapy with concomitant surgical bypass. The authors describe the decision-making process concerning cerebral revascularization and present outcomes that were achieved in a large case series of complex IAs managed with cerebral revascularization and parent artery occlusion. The authors retrospectively reviewed the medical records, including neuroimaging studies, operative reports, and follow-up clinic notes, of all patients who were treated at the National Brain Aneurysm Center between July 1997 and June 2015 using cerebral revascularization as part of the management of an IA. They recorded the location, rupture status, and size of each IA, as well as neurological outcome using the modified Rankin Scale (mRS), aneurysm and bypass status at follow-up, and morbidity and mortality. The authors identified 126 patients who underwent revascularization surgery for 126 complex, atheromatous, calcified, or previously coiled aneurysms. Ninety-seven lesions (77.0%) were unruptured, and 99 (78.6%) were located in the anterior circulation. Aneurysm size was giant (≥ 25 mm) in 101 patients, large (10-24 mm) in 9, and small (≤ 9 mm) in 16 patients. Eighty-four low-flow bypasses were performed in 83 patients (65.9%). High-flow bypass was performed in 32 patients (25.4%). Eleven patients (8.7%) underwent in situ or intracranial-intracranial bypasses. Major morbidity (mRS score 4 or 5) occurred in 2 (2.4%) low-flow cases and 3 (9.1%) high-flow cases. Mortality occurred in 2 (2.4%) low-flow cases and 2 (6.1%) high-flow cases. At the 12-month follow-up, 83 (98.8%) low-flow and 30 (93.8%) high-flow bypasses were patent. Seventy-five patients (90.4%) undergoing low-flow and 28 (84.8%) high-flow bypasses had an mRS score ≤ 2. There were no statistically significant differences in patency rates or complications between low- and high-flow bypasses. When treating challenging and complex IAs, incorporating revascularization strategies into the surgical repertoire may contribute to achieving favorable outcomes. In our series, low-flow bypass combined with isolated proximal or distal parent artery occlusion was associated with a low rate of ischemic complications while providing good long-term aneurysm control, potentially supporting its wider utilization in this setting. The authors suggest that consideration should be given to managing complex IAs at high-volume centers that offer a multidisciplinary team approach and the full spectrum of surgical and endovascular treatment options to optimize patient outcomes.

AB093. The effect of different strategies of vessel management on vasovasostomy

BackgroundTo study the effect of different strategies of vessel management on vasovasostomy.MethodsFifty 8-week-old male Sprague-Dawley rats were randomly divided into groups A, B, C, D and E. In group A all the vessels were preserved. In group B all vessels were ligated and cut. In group C only arteries were preserved. In all the groups above end to end anastomosis were performed and contralateral testis was removed. In group D only veins were preserved. Group E is the control group with vas deferens intact. All rats’ testicles were measured the size before operations. After 4 weeks, the rats were raised with female rats with 1:1 in the same cage for 2 weeks and the number of pregnant rats were recorded. Then rats were sacrificed, dissected and testicles and vas deferens were collected and detect the patency.ResultsThe patency rate was 90%, 80%, 90%, 80%, 100% and conception rate was 30%, 30%, 20%, 30%, 80% in groups A, B, C, D and E respectively. Preoperative testicular volume was 1.88667±0.11912, 1.176293±0.06971, 1.91651±0.1163, 1.82947±0.12312, 1.80818±0.149 cm3 in groups A, B, C, D and E respectively and 6 weeks postoperative testicular volume was 1.21519±0.19, 1.20181±0.17, 1.27018±0.29, 1.23696±0.21, 1.78842±0.12 cm3. Rate of testicular atrophy was 70%, 50%, 50%, 70%, 0% and rate of postoperative adhesion was 60%, 50%, 50%, 60%, 0% in groups A, B, C, D and E respectively. There was no significant difference in patency rate, conception rate, testicular atrophy and adhesion among the groups (P>0.05) while statistically significant to the control group (P<0.05). Logistic regression analysis showed postoperative adhesion increased the risk testicular atrophy. (OR =60.000000, P<0.05), while testicular atrophy was negatively correlated with pregnancy rate (OR =0.048128, P<0.05).ConclusionsDevascularization does not affect the surgical outcomes of vasovasostomy (VV). Postoperative adhesion can increase the risk of testicular atrophy after vasovasostomy, then consequently affects the rate of pregnancy. Reduction in postoperative adhesion may play a role in vasovasostomy outcomes.

Factors Affecting the Results of Superficial Femoral Artery Stenting.

The aim of this study was to assess the durability of superficial femoral artery (SFA) stents and factors that affect stent patency. A retrospective assessment of 214 SFA stent procedures between 2003 and 2012 was conducted from a prospectively compiled database. Patency rates and patient outcomes were compiled from case notes and computerized records. Stent patency was confirmed by either duplex scan or clinical examination (palpable distal pulse). Survival and patency were compared across a range of factors using Kaplan-Meier plots and log-rank tests. Factors found to be significant were further assessed by Cox regression models. Data were analyzed for 214 limbs in 205 patients. Inclusion criteria included those patients who received an SFA stent for treatment of claudication or critical limb ischemia (CLI) with follow-up data. This gave a study group of 151 limbs divided into 76 claudicant and 75 patients with CLI (male-female ratio = 103:48, mean age 71 years, standard deviation 11.7). Seventy-one percent of procedures were elective and 29% were emergency procedures; 53% of procedures were carried out on a day case basis. Median follow-up was 11 months (range 1 day-89 months). Patency was significantly worse for patients with CLI (P = .009), with a 1- and 3-year patency of 63% and 34% compared to 79% and 60% in patients with claudication. Significant factors associated with patency included oral therapy controlled diabetes (P = .003), lesions located in either the mid-SFA (P = .029) or the mid-popliteal (P = .013), and periprocedural complications (P = .005). There was no significant difference in patency rates between insulin-dependent and nondiabetic patients (hazard ratio: 1.0, 95% confidence interval: 0.4-5.6, P = .983). The overall amputation rate for the total study group was 5%. Patients with 1- and 3-year survival were 98% and 96% in the claudication group and 74% and 51%, respectively, in the CLI group. SFA stents have superior outcomes in claudicants. Patency is related to severity of disease, diabetes, and location of disease.

Effect of Intra Operative Intravenous Injection of Heparin on Patency Rate of Radio Cephalic Autogenous Arteriovenous-Fistula in Chronic Renal Failure Patients

Background: Currently, there is no standard for the use of systemic heparin during creation of Arteriovenous (AV) fistula to decrease the incidence of postoperative thrombotic complications. Objectives: The goal of this study was to evaluate the effects of intra-operative IV heparin on patency rate and postoperative bleeding complications in patients undergoing surgery for AV fistula. Patients and Methods: A prospective, randomized controlled study was performed on 50 patients undergoing AV fistula creation, who were randomly divided in two groups. The control group received no systemic heparin and the heparin group received 5,000 units of intravenous heparin before clamping of theartery. Results: There was a significant difference in patency rate between the heparin and control groups (96% vs. 72%, P = 0.021), and there were no significant differences in operative time (P = 0.55). Perioperative bleeding was not significantly different between the two groups. Conclusions: The results suggest that intra operative administration of heparin has statistically significant effects on patency rates yet not on postoperative bleeding complications. Larger trials with longer follow-up durations and assessment of maturation rates are needed to determine this effect on fistula outcome.

Intravascular stenting in microvascular anastomoses.

The effect of intravascular stenting (IVaS) on microvascular anastomoses has given adverse results. For experienced microsurgeons the benefit of IVaS is doubtful. We have investigated the potential benefit of the IVaS technique for two groups of inexperienced microsurgeons with different surgical levels of experience (medical students and young residents). Experienced microsurgeons acted as a control group. In an experimental crossover study, 139 microsurgical anastomoses were performed on the femoral artery in 70 rats by 10 surgeons. On one side of the rat, the IVaS technique was used. A small piece of 5-0 nylon monofilament was placed in the vessel lumen, acting as a temporary stent during microvascular anastomosis. A conventional technique without the stent was performed on the other side. Patency rates of the vessels in each group were compared as well as the time spent on the anastomosis. No significant difference in patency rates was seen between the stenting and conventional technique in all three groups. The experienced microsurgeons had 100% patency rate with both techniques. The medical students had 20/28 in the IVaS and 19/28 conventional group and the patency rates for the residents were 23/27 using IVaS and 23/28 using the conventional technique. The residents were faster using the IVaS whereas the students and experienced microsurgeons were faster without the stent. The IVaS technique did not seem to benefit either the inexperienced or experienced microsurgeons regardless of their clinical experience. The study also shows that some surgical experience seems to be an advantage in performing microsurgery.

Early Cannulation Grafts in Straight Axillo‐Axillary Angioaccesses Avoid Central Catheter Insertions

The need for early cannulation grafts exists to prevent use of central venous catheters. We report our experience in patients who had a straight axillo-axillary angioaccess. All patients who have undergone an early cannulation axillo-axillary angioaccess between 2008 and 2010 were reviewed. Fifteen patients had 16 procedures. Of these, eight were women and their mean age was 56. All patients had exhausted access options bilaterally. All had previous catheter insertions with either sepsis or jugular veins thrombosis. They all had an axillary artery to axillary vein angioaccess using an early cannulation graft. Flixene(®) (Atrium Medical, Hudson, NH, USA) was used in 10 cases, whereas Rapidax(®) (Vascutek Ltd., Renfrewshire, UK) in 6. In 12 cases, grafts were cannulated after 12 hours, in 4 after 24 hours (12 hours-8 days, mean 1.8 days). For Flixene(®) , mean delay to cannulation was 1.1 days, whereas 2.71 for Rapidax(®) (p < 0.05). Primary patency rates were 92.9% and 65.7% at 6 weeks and 1 year, respectively. Secondary patency rates were 92.9% and 83.5%. There was no significant difference in patency rates between grafts. Early cannulation grafts in a complex position are safe and efficient considering their patency and complication rates. It avoids using central venous catheters.

Outcome Comparison of Two Surgical Methods Used for the Treatment of Acute Thrombosis of Arteriovenous Fistulas: Thrombectomy Versus De Novo Creation of Arteriovenous Fistula

The aim of this study was to evaluate efficacy of two surgical methods used for the treatment of acute arteriovenous fistula (AVF) thrombosis. Twenty two out of twenty five patients that were admitted at the Clinic for vascular surgery in Sarajevo received successful surgical treatment for the salvage of acutely thromboses AVF from 2007-2009. They were included in retrospective, descriptive clinical study. Based on the type of surgical procedures performed, 22 patients were divided into two groups. The first group included 10 patients and they had successful thrombectomy of thromboses AVF while 12 patients in second group underwent de novo creation of AVF using blood vessels already exploited for construction of thromboses AVF. Patency rate of salvaged AVF in analyzed groups was compared one month and 6 months after intervention. In the postoperative follow up there was no statistically significant difference in patency rate of salvaged AVF between analyzed groups after one month, (80% vs 100%, Fisher exact test value =2,520, p= 0.195). Patency rate of salvaged AVF after six months of the follow up was significantly better in group that received de novo construction of AVF when compared to thrombectomy group (25% vs. 91%, Fisher exact test value = 1,062, p=0.002). De novo construction of AVF in case of acutely thrombosed AVF offered better patency rate of salvaged AVF when compared to surgical thrombectomy in the follow up period of six months.