Upper thigh loop prosthetic arterio-venous grafts (AVG) for dialysis access: An Indian perspective

Introduction: Hemodialysis forms the most common replacement therapy for majority of Indians suffering from chronic kidney disease (CKD). Multiple access failure and central vein stenosis has become commonplace in Indian dialysis access patients and there is a burgeoning need for more advanced hemodialysis (HD) access options. Upper thigh arterio-venous grafts (AVG) are seldom inserted due to fear of infection and limb ischemia. Materials and methods: This is a single institutional, retrospective, descriptive case study of consecutive patients who underwent upper thigh prosthetic AVG over a period of 7 years. All these patients had exhausted options of upper limb access and or had central vein stenosis. AVG from the proximal superficial femoral artery (SFA) to the proximal great saphenous vein (GSV) in a loop configuration using polytetrafluoroethylene (PTFE) was carried out in the upper thigh. Results: A total of 24 patients had undergone upper thigh loop AVG. Their age varied from 24 to 77 years. The median follow-up period was 3 years. Five of these grafts developed infection (21%) which led to primary failure. A primary patency of 71% (17/24 patients) was achieved at 1 year. Thrombosis developed at a mean of 16.7 months after the primary procedure. Adjunctive procedures such as thrombectomy, segmental replacement of graft, patch angioplasty, balloon angioplasty, and stenting were required in 75% of patients to achieve a secondary patency of 86% at 1 year. Three grafts were explanted without limb loss. Conclusion: Upper thigh loop AVG forms a reliable alternate dialysis access option for patients with failed upper limb access sites or central vein occlusion. Adjunctive procedures are key to maintaining patency in these grafts. Good secondary patency is achievable, and the infection rates are similar to arm AVG. Close follow-up and timely intervention are key to long term dialysis through these grafts.

Cell Viability Assessment Using Fluorescence Vital Dyes and Confocal Microscopy in Evaluating Freezing and Thawing Protocols Used in Cryopreservation of Allogeneic Venous Grafts

The authors present their contribution to the improvement of methods suitable for the detection of the freezing and thawing damage of cells of cryopreserved venous grafts used for lower limb revascularization procedures. They studied the post-thaw viability of cells of the wall of cryopreserved venous grafts (CVG) immediately after thawing and after 24 and 48 h culture at +37 °C in two groups of six CVG selected randomly for slow thawing in the refrigerator and rapid thawing in a water bath at +37 °C. The grafts were collected from multi-organ and tissue brain-dead donors, cryopreserved, and stored in a liquid nitrogen vapor phase for five years. The viability was assessed from tissue slices obtained by perpendicular and longitudinal cuts of the thawed graft samples using in situ staining with fluorescence vital dyes. The mean and median immediate post-thaw viability values above 70% were found in using both thawing protocols and both types of cutting. The statistically significant decline in viability after the 48-h culture was observed only when using the slow thawing protocol and perpendicular cutting. The possible explanation might be the “solution effect damage” during slow thawing, which caused a gentle reduction in the graft cellularity. The possible influence of this phenomenon on the immunogenicity of CVG should be the subject of further investigations.

“TAP” technique on bifurcation lesion of Y graft in a patient with NSTEMI complicated with cardiogenic shock

Introduction. Bifurcation lesions on venous Y grafts are rare. We presented a case of a woman who developed NSTEMI complicated by cardiogenic shock due to a bifurcation lesion on the venous Y graft for LAD and RCX. Case outline. A 72-year-old woman was admitted to the CCU as an emergency in September 2017 due to the acute heart failure followed by the development of cardiogenic shock. Urgent coronarography revealed severe atherosclerotic disease of native coronary arteries with significant bifurcation lesion on venous Y graft for LAD and RCX (medina classification of 1,1,1) with TIMI 2 flow. According to the general condition of patient, a life-saving ad hoc PCI was performed. Two stents were implanted in Y graft with T and protrusion technique achieving optimal result followed with patient stabilization. On one-year follow-up patient was without symptoms of angina, and CT coronarography revealed patent both stents in Y graft. Best to our knowledge this was the first described TAP technique used on Y graft. Conclusion. The PCI on VG is not uncommon either in elective cases or in cases with ACS due to the poorer persistence and more frequent progression of atherosclerotic disease in the venous grafts. The use of bifurcation techniques for the treatment of lesions on VG and especially on the Y graft is rare, but it can be used the same way it is used in native vessels.

35 Years Angiographic Follow Up Of Atherosclerotic Cardiovascular Disease Including Redo Cabg, Carotid Artery Stenting & Multiple Interventions To Saphenous Venous Grafts

Percutaneous coronary intervention (PCI) has got more benefit as compared to redo CABG in terms of morbidity & mortality in patients presented with degenerated CABG grafts. We report a case of post CABG patient treated successfully with multiple PCI to SVG grafts- a 35 years follow up.

Evaluation of bypass grafts after minimally invasive coronary artery bypass grafting according to the results of MSCT- angiography

Background Minithoracotomy avoids the complications specific to sternotomy access, which in turn creates the conditions for early activation and rehabilitation of patients, especially elderly, with diabetes mellitus, obesity, disorders of the musculo-skeletal system. Purpose To assess the patency of grafts after minimally invasive coronary artery bypass grafting (MICS CABG). Methods We analyzed the results of 50 MSCT- angiography made to patients with MICS CABG operated between 2014 and 2016 (28,5±13,5 months after surgery). Totally 132 conduits were used, 47 (35.6%) of them – arterial, 85 (64.4%) – venous. In all cases left internal mammary artery (LIMA) was used for revascularization of the left anterior descending artery (LAD). The great saphenous vein was used as a conduit for revascularization of: diagonal branch (DA) – 10 (11.7%) cases, left circumflex artery (LCx) – 44 (51.8%), right coronary artery (RCA) – 12 (14.1%), posterior interventricular branch – 19 (22.4%). Assessment of the patency of grafts were performed: 1–2 years (33 conduits: 13 arterial, 20 venous), after 2–3 years (51 conduits: 19 arterial, 32 venous) and after 3–4 years (48 conduits: 15 arterial, 33 venous). Results Assessment of coronary grafts patency in the first period revealed occlusion of 3 (15%) venous conduits. In 2 cases, the venous conduit was anastomosed with the LCx, in 1 case with the RCA. The cumulative patency of the grafts was as follows: arterial – 100%, venous – 85%. In the second point of the study occlusion and stenotic changes of LIMA has not been revealed. Determined occlusion 5 (15,6%) venous grafts. In all cases, the occluded venous conduits revascularized the RCA. Total permeability of conduits: arterial – 100%, venous-84.4%. In the third time interval it was revealed: in 1 case of LIMA occlusion and 7 venous grafts, in 4 cases in the area of the LCx, in 2 – DA and in 1 case – in the area of the RCA. Total patency of grafts: arterial – 93.3%, venous – 78.8%. Total permeability of conduits: arterial – 97.9%, venous – 82.4%. Conclusion The analysis shows good long–term results of the functioning of grafts after MICS CABG and their comparability with the results of patency of the conduits after CABG performed by the traditional Funding Acknowledgement Type of funding source: None

A Review of Arterial Grafts Used for Microvascular Arterial Reconstruction

Arterial grafts are sometimes used in microvascular reconstruction and their clinical benefit over standard venous grafts is unknown. To determine arterial graft utilization in clinical microvascular arterial reconstruction, a review of the literature was done. PubMed search resulted with 4,352 finds, and after screening for relevance, 11 articles reporting on 55 arterial grafts were analyzed. All reports were retrospective studies, case reports, and case series, with no randomized controlled trials. Two retrospective series reported better patency of arterial versus venous grafts in upper-limb revascularization for chronic occlusion, but the findings were highly biased. Better patency of arterial grafts did not lead to higher rate of clinical improvement. Antiplatelet and lipid-lowering agents seem to be underused in venous graft recipients and use of no-touch venous grafting has not been reported. Based on the available data, routine use of arterial grafts cannot be recommended. Studies that show better patency of arterial grafts in hand revascularization for chronic vascular insufficiency are retrospective and biased, so a randomized controlled trial is needed.

The Challenging Dream of Rene Favaloro and Genesis of Saphenous Venous Grafts

not available Cardiovasc. j. 2020; 12(2): 149-153