Cystathionine Gamma Lyase Is Regulated by Flow and Controls Smooth Muscle Migration in Human Saphenous Vein

The saphenous vein is the conduit of choice for bypass grafting. Unfortunately, the hemodynamic stress associated with the arterial environment of the bypass vein graft leads to the development of intimal hyperplasia (IH), an excessive cellular growth and collagen deposition that results in restenosis and secondary graft occlusion. Hydrogen sulfide (H2S) is a ubiquitous redox-modifying gasotransmitter that inhibits IH. H2S is produced via the reverse trans-sulfuration pathway by three enzymes: cystathionine γ-lyase (CSE), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST). However, the expression and regulation of these enzymes in the human vasculature remains unclear. Here, we investigated the expression of CSE, CBS and 3-MST in segments of native human saphenous vein and large arteries. Furthermore, we evaluated the regulation of these enzymes in vein segments cultured under static, venous (7 mmHg pressure) or arterial (100 mmHg pressure) pressure. CSE was expressed in the media, neointima and intima of the vessels and was negatively regulated by arterial shear stress. Adenoviral-mediated CSE overexpression or RNA interference-mediated CSE knock-down revealed that CSE inhibited primary human VSMC migration but not proliferation. We propose that high shear stress in arteriovenous bypass grafts inhibits CSE expression in both the media and endothelium, which may contribute to increased VSMC migration in the context of IH.

Unrestricted use of polymer-free sirolimus eluting stents in routine clinical practice

Stent designs with ultrathin struts may further increase the procedural success of challenging lesion subsets. The objective of this study was to assess the safety and efficacy of ultrathin strut, polymer-free sirolimus eluting stent (PF-SES) implantations in a large scale, unselected patient population.Adult patients underwent percutaneous coronary interventions (PCI) with a thin-strut PF-SES. Data from two all-comers observational studies having the same protocol (ClinicalTrials.gov Identifiers: NCT02629575 and NCT02905214) were pooled. The accumulated target lesion revascularization (TLR) rate at 9-12 months was the primary endpoint. All dual antiplatelet therapy strategies according to the applicable guidelines were permissible.In total, 7243 patients were prospectively enrolled for PCI with PF-SES in stable coronary artery disease or acute coronary syndrome (ACS). Major risk factors in the overall cohort were diabetes (37.3%), ST elevation myocardial infarction (18.1%) and non-ST myocardial infarction (24.6%). The follow-up rate was 88.6% in the overall population. The TLR rate in the overall cohort was 2.2% whereas definite/probable stent thrombosis (ST) occurred in 0.7%. In patients with in-stent restenosis lesions, the major adverse cardiac events rate was 6.4% whereas the corresponding rate for isolated left main coronary artery (LMCA) disease was highest with 6.7% followed by patients with culprit lesions in vein bypasses (VB, 7.1%). The mortality rate in patients treated in VB lesions was highest with 5.4%, followed by the isolated LMCA subgroup (3.4%) and ACS (2.6%).PCI with PF-SES in an unselected patient population, is associated with low clinical event and ST rates. Furthermore, PF-SES angioplasty in niche indications demonstrated favorable safety and efficacy outcomes with high procedural success rates.

Antibiotic Prophylaxis in Autologous Vein Graft Reconstructions of the Lower Extremity

BACKGROUND

Different factors contribute to infection after arterial reconstructive surgery. Prophylactic antibiotic use during surgery is widespread, however, there is insufficient evidence to support the use of prophylactic antibiotics with autologous vein grafting. The aim of our study was to assess the effect of single-dose prophylactic antibiotics in patients undergoing autologous vein grafting.

METHODS

Patients undergoing arterial bypass reconstruction in the lower extremity between 2004 and 2012 were retrospectively screened for use of vein grafts. Patients receiving single-dose antibiotic prophylaxis (group 1) were compared with those not receiving prophylaxis (group 2).

RESULTS

Primary outcome was surgical site infection (SSI), and 142 patients were included. The SSI occurred in 22% of patients in group 1 and in 29% of patients in group 2 (P = .39; odds ratio: 1.46 confidence interval 95%: 0.61-3.47).

CONCLUSIONS

Results showed no significant effect from single-dose antibiotic prophylaxis on lowering the incidence of SSI.

Surgical femorocaval bypass for treating chronic iliac vein occlusion: a case report

Chronic inferior vena cava and iliac vein occlusion, caused by long-term of deep venous thrombosis, will lead to swelling of the limbs, venous claudication and intractable ulcer. However, conservative treatment is often ineffective for vein occlusion. With the development of interventional techniques, endovascular therapy has become the first choice for the treatment of vein occlusion with higher success rate and lower trauma. However, for cases those fail endovascular therapy or for segmental veno-occlusive diseases with low long-term patency rate, venous bypass might be the only option. And, design of anastomotic stoma and orificium fistulae design is crucial to the success of operation. A case of long term deep venous thrombosis patient with occlusion in bilateral iliac vein and distal inferior vena cava was admitted and treated with interventional therapy. Unfortunately, this method failed. Then, we selected reasonable anastomotic stoma and orificium fistulae and performed femorocaval bypass. The 12 month follow-up results showed that the swelling was successively relieved and the ulcer healed. This indicated that rational anastomotic stoma and orificium fistulae could guarantee the exact clinical efficacy of venous bypass and higher long-term patency rate.