Innovative Technique for Below the Knee Arterial Revascularisation Using Porcine Self Made Stapled Pericardial Tube Grafts.

When no autologous vein is available for distal bypass in the setting of chronic limb threatening ischaemia (CLTI), new alternatives are required to solve the problems of availability, patency, and resistance to infection. An innovative technique of below the knee bypass for CLTI using a porcine self made stapled pericardial tube graft is reported. An 84 year old man, admitted with right CLTI with foot infection due to long occlusion of the femoropopliteal segment, required urgent revascularisation. In the absence of autologous vein and cryopreserved vessels, a 4 mm self made stapled porcine pericardial tube graft 56 cm long was created from two 14 × 8 cm patches, to perform a femorotibioperoneal trunk bypass. On day 10, bypass thrombectomy and balloon angioplasty of the distal anastomosis were needed to treat early occlusion. Oral anticoagulation was then started. Right toe pressure increased from 0 to 70 mmHg, and no infection was reported. Complete wound healing was achieved. At six months, the bypass was still patent. The use of porcine self made stapled pericardial tube grafts could offer new options for revascularisation in CLTI. Larger cohort studies with longer follow up are needed to confirm this successful preliminary experience

Traitement par l’exercice physique chez le patient avec une artériopathie oblitérante des membres inférieurs [Exercise training therapy in patients with lower extremity peripheral artery disease]

Patients with lower extremity peripheral artery disease (PAD) have decreased functional capacities leading to decreased quality of life and increased cardiovascular morbidity and mortality. Exercise therapy is recommended among first-choice therapeutic options and improves overall physical function and quality of life in symptomatic patients with PAD. Exercise therapy is also effective in patients with PAD following revascularization. Other than walking, different training modalities are safe, feasible and effective to induce clinical benefits for these patients. We present here the role of exercise therapy and its specificities in the management of PAD

Patient-specific computational flow simulation reveals significant differences in paravisceral aortic hemodynamics between fenestrated and branched endovascular aneurysm repair.

Endovascular aneurysm repair with four-vessel fenestrated endovascular aneurysm repair (fEVAR) or branched endovascular aneurysm repair (bEVAR) currently represent the forefront of minimally invasive complex aortic aneurysm repair. This study sought to use patient-specific computational flow simulation (CFS) to assess differences in postoperative hemodynamic effects associated with fEVAR vs bEVAR. Patients from two institutions who underwent four-vessel fEVAR with the Cook Zenith Fenestrated platform and bEVAR with the Jotec E-xtra Design platform were retrospectively selected. Patients in both cohorts were treated for paravisceral and extent II, II, and V thoracoabdominal aortic aneurysms. Three-dimensional finite element volume meshes were created from preoperative and postoperative computed tomography scans. Boundary conditions were adjusted for body surface area, heart rate, and blood pressure. Pulsatile flow simulations were performed with equivalent boundary conditions between preoperative and postoperative states. Postoperative changes in hemodynamic parameters were compared between the fEVAR and bEVAR groups. Patient-specific CFS was performed on 20 patients (10 bEVAR, 10 fEVAR) with a total of 80 target vessels (40 renal, 20 celiac, 20 superior mesenteric artery stents). bEVAR was associated with a decrease in renal artery peak flow rate (-5.2% vs +2.0%; P < .0001) and peak pressure (-3.4 vs +0.1%; P < .0001) compared with fEVAR. Almost all renal arteries treated with bEVAR had a reduction in renal artery perfusion (n = 19 [95%]), compared with 35% (n = 7) treated with fEVAR. There were no significant differences in celiac or superior mesenteric artery perfusion metrics (P = .10-.27) between groups. Time-averaged wall shear stress in the paravisceral aorta and branches also varied significantly depending on endograft configuration, with bEVAR associated with large postoperative increases in renal artery (+47.5 vs +13.5%; P = .002) and aortic time-averaged wall shear stress (+200.1% vs -31.3%; P = .001) compared with fEVAR. Streamline analysis revealed areas of hemodynamic abnormalities associated with branched renal grafts which adopt a U-shaped geometry, which may explain the observed differences in postoperative changes in renal perfusion between bEVAR and fEVAR. bEVAR may be associated with subtle decreases in renal perfusion and a large increase in aortic wall shear stress compared with fEVAR. CFS is a novel tool for quantifying and visualizing the unique patient-specific hemodynamic effect of different complex EVAR strategies. This study used patient-specific CFS to compare postoperative hemodynamic effects of four-vessel fenestrated endovascular aneurysm repair (fEVAR) and branched endovascular aneurysm repair (bEVAR) in patients with complex aortic aneurysms. The findings indicate that bEVAR may result in subtle reductions in renal artery perfusion and a significant increase in aortic wall shear stress compared with fEVAR. These differences are clinically relevant, providing insights for clinicians choosing between these approaches. Understanding the patient-specific hemodynamic effects of complex EVAR strategies, as revealed by CFS, can aid in future personalized treatment decisions, and potentially reduce postoperative complications in aortic aneurysm repair

Ten Year Experience of Using Cryopreserved Arterial Allografts for Distal Bypass in Critical Limb Ischaemia.

In critical limb ischaemia (CLI), current guidelines recommend revascularisation whenever possible, preferentially through endovascular means. However, in the case of long occlusions or failed endovascular attempts, distal bypasses still have a place. Single segment great saphenous vein (GSV), which provides the best conduit, is often not available and currently there is no consensus about the best alternative graft. From January 2006 to December 2015, 42 cryopreserved arterial allografts were used for a distal bypass. Autologous GSVs or alternative autologous conduits were unavailable for all patients. The patients were observed for survival, limb salvage, and allograft patency. The results were analysed with Kaplan-Meier graphs. Estimates of secondary patency at one, two and five years were 81%, 73%, and 57%, respectively. Estimates of primary patency rates at one, two and five years were 60%, 56%, and 26%, respectively. Estimates of limb salvage rates at one, two and five years were 89%, 89%, and 82%, respectively. Estimates of survival rates at one, two and five years were 92%, 76% and 34%, respectively. At 30 days, major amputations and major adverse cardiac events were one and zero, respectively. Six major amputations occurred during the long-term follow up. Despite a low primary patency rate at two years, the secondary patency of arterial allografts is acceptable for distal bypasses. This suggests that cryopreserved arterial allografts are a suitable alternative for limb saving distal bypasses in the absence of venous conduits, improving limb salvage rates and, possibly, quality of life

Predictive factors of surgical complications in the first year following kidney transplantation.

In the recent years, an increased use of marginal donors and grafts and a growing prevalence of peripheral arterial disease in the recipients have been observed. Meanwhile, the open surgical technique for kidney transplantation has not changed. The aim of this study is to analyze all surgical complications occurring in the first year after kidney transplant and to determine potential predictive risk factors. Data of the 399 patients who underwent kidney transplant in our University Hospital between January 2006 and December 2015 were retrospectively reviewed. The primary endpoint was the overall rate of vascular, parietal and urological complications at 1 year following kidney transplantation. The secondary outcomes were graft and patient' survival rates, and the identification of predictive factors of the surgical complications. Twenty-four percent of patients developed 134 complications. Vascular complication represented 39% of all complications and resulted in 9 graft losses. Parietal and urological complications represented 46% and 15% of all complications, respectively, No parietal or urological complications were associated with graft loss. Five patients died during the first year, none of these cases was associated with graft loss. The graft survival rate reached 96% at 1 year, including patients still alive. The occurrence of surgical complication was associated with reduced graft survival at 1 year. Using a multivariate analysis, 4 predictive factors were identified: age, deceased donor, operative time and dyslipidemia. Surgical complications after kidney transplantation remained frequent and age, deceased kidney donors, and operative time were identified as risk factors. As vascular complications were a major cause of early graft loss, efforts should aim to reduce their occurrence to increase graft survival

Hydrogen Sulphide Release via the Angiotensin Converting Enzyme Inhibitor Zofenopril Prevents Intimal Hyperplasia in Human Vein Segments and in a Mouse Model of Carotid Artery Stenosis.

Hypertension is a major risk factor for intimal hyperplasia (IH) and re-stenosis following vascular and endovascular interventions. Preclinical studies suggest that hydrogen sulphide (H <sub>2</sub> S), an endogenous gasotransmitter, limits re-stenosis. While there is no clinically available pure H <sub>2</sub> S releasing compound, the sulfhydryl containing angiotensin converting enzyme inhibitor zofenopril is a source of H <sub>2</sub> S. Here, it was hypothesised that zofenopril, due to H <sub>2</sub> S release, would be superior to other non-sulfhydryl containing angiotensin converting enzyme inhibitors (ACEi) in reducing intimal hyperplasia. Spontaneously hypertensive male Cx40 deleted mice (Cx40 <sup>-/-</sup> ) or wild type (WT) littermates were randomly treated with enalapril 20 mg or zofenopril 30 mg. Discarded human vein segments and primary human smooth muscle cells (SMCs) were treated with the active compound enalaprilat or zofenoprilat. IH was evaluated in mice 28 days after focal carotid artery stenosis surgery and in human vein segments cultured for seven days ex vivo. Human primary smooth muscle cell (SMC) proliferation and migration were studied in vitro. Compared with control animals (intima/media thickness 2.3 ± 0.33 μm), enalapril reduced IH in Cx40 <sup>-/-</sup> hypertensive mice by 30% (1.7 ± 0.35 μm; p = .037), while zofenopril abrogated IH (0.4 ± 0.16 μm; p < .002 vs. control and p > .99 vs. sham operated Cx40 <sup>-/-</sup> mice). In WT normotensive mice, enalapril had no effect (0.9665 ± 0.2 μm in control vs. 1.140 ± 0.27 μm; p > .99), while zofenopril also abrogated IH (0.1623 ± 0.07 μm; p < .008 vs. control and p > .99 vs. sham operated WT mice). Zofenoprilat, but not enalaprilat, also prevented IH in human vein segments ex vivo. The effect of zofenopril on carotid and SMCs correlated with reduced SMC proliferation and migration. Zofenoprilat inhibited the mitogen activated protein kinase and mammalian target of rapamycin pathways in SMCs and human vein segments. Zofenopril provides extra beneficial effects compared with non-sulfhydryl ACEi in reducing SMC proliferation and re-stenosis, even in normotensive animals. These findings may hold broad clinical implications for patients suffering from vascular occlusive diseases and hypertension

The effects of COVID-19 pandemic on patients with lower extremity peripheral arterial disease: A near miss disaster.

The COVID-19 pandemic has led to widespread postponement and cancelation of elective vascular surgeries in Switzerland. The consequences of these decisions are poorly understood. In this observational, retrospective, single-center cohort study, we describe the impact of COVID-19 pandemic containment strategies on patients with lower extremity peripheral arterial disease (PAD) referred during the period March 11, to May 11, 2020, compared to the same time frames in 2018 to 2019. Patients admitted for acute limb ischemia (ALI) or chronic PAD and undergoing urgent or elective vascular surgery or primary amputation were included. Patients' characteristics, indications for admission, and surgical features were analyzed. The occurrence of 30 day outcomes was assessed, including length of stay, rates of major adverse cardiovascular events (MACE) and major adverse limb events (MALE), and procedural and hemodynamic success. Overall, 166 patients were included. Fewer subjects per 10 day period were operated in 2020 compared to, 2018 to 2019 (6.7 vs. 10.5, respectively; P < 0.001). The former had higher rates of chronic obstructive pulmonary disease (COPD) (25% vs. 11.1%; P = 0.029), and ASA score (3.13 vs. 2.90; P = 0.015). The percentage of patients with ALI in 2020 was about double that of the same period in 2018 to 2019 (47.5% vs. 24.6%; P = 0.006). Overall, the types of surgery were similar between 2020 and 2018 to 2019, while palliative care and primary amputations occurred only in 2020 (5 out 40 cases). The rate of post-operative MACE was significantly higher in 2020 (10% vs. 2.4%; P = 0.037). During the first state of emergency for COVID-19 pandemic in 2020, less regular medical follow-up and hindered hospital access could have resulted in more acute and advanced clinical presentations of patients with PAD undergoing surgery. Guidelines are needed to provide appropriate care to this vulnerable population and avoid a large-scale disaster