Peter Balaz

Aneurysmorrhaphy is an easy technique for arteriovenous fistula salvage.

The life-saving procedures for patients in chronic renal failure (CRF) are hemodialysis (HD) or successful kidney transplantation. HD requires a properly placed and functioning vascular access, most often obtained by creating an arteriovenous fistula (AVF). The long-term patency of AVFs is limited, in addition to other factors, by the development of intimal hyperplasia and the process results in venous wall thickening and progressive fistula occlusion. Another problem is limited patency, due to the development of pseudoaneurysm, which is associated with an increased risk of thrombosis, infection and bleeding, difficult cannulation for dialysis, pain and cosmetic defects. Treatment is focused on rapidly progressing pseudoaneurysms, which can predispose to rupture, technical problems during cannulation because of pseudoaneurysm size or a growing intraluminal thrombus. Most of these patients are scheduled for pseudoaneurysm removal and new fistula construction or, occasionally, an endovascular procedure involving stent graft implantation. This paper describes a simple and inexpensive technique of managing an AVF pseudoaneurysm, i.e. aneurysmorrhaphy. To offset the weakening of the venous wall by suture following aneurysmorrhaphy, an external polyethylene terephthalate (PET) prosthesis was implanted in the vein to prevent the development of intimal hyperplasia in the de novo created AVF.

Identification of expanded-criteria donor kidney grafts at lower risk of delayed graft function.

Background Organ shortage leads to the increased use of expanded-criteria donor (ECD) kidneys, which contribute to a higher risk of delayed graft function (DGF) after transplantation. The aim of this study was to determine factors that may better predict the risk of DGF. Methods Histologic assessments of donor renal biopsy were used with other clinical variables to predict the risk of DGF after kidney transplantation. The total Banff score equaled the sum of interstitial fibrosis (CI), tubular atrophy, arteriolar hyaline thickening, fibrous intimal thickening (CV), and fraction of sclerotized glomeruli. Results In total, 126 of 344 patients developed DGF after kidney transplantation. The histologic score for CI, tubular atrophy, and CV and the total Banff score were increased in patients with DGF. Only CI and CV were independent predictors of DGF (P<0.01). A CIV score (CI+CV; odds ratio, 2.68; 95% confidence interval, 1.55–4.66; P<0.001) was superior to the combination of the total Banff score (odds ratio, 1.48; 95% confidence interval, 0.85–2.55; P=NS). A CIV score≥1, donor age more than 51 years, and anoxia donor brain injury were associated with the highest risk of DGF. A CIV<1 identified a subgroup of ECDs at a lower risk of DGF comparable with standard-criteria donors (29.3% vs. 28.4%). Conclusions Composite CIV score better identifies ECD kidneys with a lower risk of developing DGF. Morphologic evaluation of ECD kidneys and donor characteristics may improve kidney allocation.

Combined infrainguinal reconstruction and infrapopliteal intraluminal angioplasty for limb salvage in critical limb ischemia

The aim of this retrospective study was to assess the success rates of limb salvage, and the primary and secondary patency rates of reconstructions of critical limb ischemia (CLI) patients undergoing combined infrainguinal reconstruction and intraluminal angioplasty of crural arteries. In 2000-2005, infrainguinal reconstruction with concomitant intraluminal angioplasty of crural arteries was performed in 30 patients with CLI, mean age was 63 years (S.D.=10); according to the Fontaine classification, 28 (93%) patients had stage IV and 2 (7%) stage III ischemia. During mean follow-up of 12.9 (S.D.=16.9) months, primary 1-year patency of vascular reconstruction was seen in 16 (52.6%) patients of our group. Secondary 1-year patency over the same follow-up period was documented in 17 (56.2%) patients and 1-year limb salvage was obtained in 25 (82.6%) patients. Based on this finding, we consider a combined surgical and endovascular procedure to be the method of choice in limb salvage in patients with CLI not allowing for an isolated endovascular procedure.

True aneurysm in autologous hemodialysis fistulae: definitions, classification and indications for treatment

Introduction Definition, etiology, classification and indication for treatment of the arteriovenous access (AVA) aneurysm are poorly described in medical literature. The objectives of the paper are to complete this information gap according to the extensive review of the literature. Methods A literature search was performed of the articles published between April 1, 1967, and March 1, 2014. The databases searched included Medline and the Cochrane Database of Systematic Reviews. The eligibility criteria in this review studies the need to assess the association of aneurysms and pseudoaneurysms with autologous AVA. Aneurysms and pseudoaneurysms involving prosthetic AVA were not included in this literature review. From a total of 327 papers, 54 non-English papers, 40 case reports and 167 papers which did not meet the eligibility criteria were removed. The remaining 66 papers were reviewed. Results Based on the literature the indication for the treatment of an AVA aneurysm is its clinical presentation related to the patients discomfort, bleeding prevention and inadequate access flow. A new classification system of AVA aneurysm, which divides it into the four types, was also suggested. Conclusions AVA aneurysm is characterized by an enlargement of all three vessel layers with a diameter of more than 18 mm and can be presented in four types according to the presence of stenosis and/or thrombosis. The management of an AVA aneurysm depends on several factors including skin condition, clinical symptoms, ease of cannulation and access flow. The diameter of the AVA aneurysm as a solo parameter is not an indication for the treatment.

Tubular atrophy and low netrin-1 gene expression are associated with delayed kidney allograft function.

Background Delayed graft function (DGF) caused by ischemia/reperfusion injury (I/RI) negatively influences the outcome of kidney transplantation. This prospective single-center study characterized the intrarenal transcriptome during I/RI as a means of identifying genes associated with DGF development. Methods Characterization of the intrarenal transcription profile associated with I/RI was carried out on three sequential graft biopsies from respective allografts before and during transplantation. The intragraft expression of 92 candidate genes was measured using quantitative real-time reverse transcriptase polymerase chain reaction (2−&Dgr;&Dgr;Ct) in delayed (n=9) and primary function allografts (n=26). Results Cold storage was not associated with significant changes to the expression profile of the target gene transcripts; however, up-regulation of 16 genes associated with enhanced activation of innate and adaptive immune responses and apoptosis was observed after reperfusion. Multivariate logistic regression analysis revealed that higher tubular atrophy scores (ct) together with a lower expression of Netrin-1 might predict DGF development (training area under the receiver operating curve=0.89, cross-validated area under the receiver operating curve=0.81). Conclusions Poor baseline tubular cell quality (defined by a higher rate of tubular atrophy) combined with the reduced potential of apoptotic survival factors represented by decreased Netrin-1 gene expression were associated with delayed kidney graft function.

Cardiac remodeling after reduction of high-flow arteriovenous fistulas in end-stage renal disease

In patients with end-stage renal disease, excessive blood flow through an arteriovenous fistula (AVF) may lead to volume overload-induced cardiac remodeling and heart failure. It is unclear which patients with hyperfunctional AVF may benefit from AVF reduction or ligation. The indication for the procedure is often based on AVF flow. Because cardiac remodeling is driven by increased venous return, which is equivalent to cardiac output, we hypothesized that an elevated cardiac index (CI) might better identify subjects with reverse remodeling after AVF reduction. Thirty patients (age 52±12 years, 73% male) with AVF flow ⩾1.5 l min−1 underwent comprehensive echocardiographic evaluations before and after AVF reduction. At baseline, 16 patients had a normal CI (2.5–3.8 l min−1 m−2) and 14 had a high CI (4.0–6.0 l min−1 m−2). A left ventricular end-diastolic diameter decrease after operation was predicted by elevated baseline CI (P<0.01), but not elevated AVF flow (P=0.07). There was a significant decrease in CI, left ventricular mass, left atrial and right ventricular diameter and pulmonary systolic pressure in the high CI group but not in the normal CI group. After AVF reduction, systemic vascular resistance decreased in the normal CI group, whereas it did not change in the high CI group. In conclusion, reduction of high-flow AVF leads to reverse cardiac remodeling but only in patients with elevated CI. The variability of the response of systemic vascular resistance to AVF flow may explain this observation. Increased CI but not increased AVF flow may better determine candidates for AVF reduction.

Early and late outcomes of hybrid endovascular and open repair procedures in patients with peripheral arterial disease

BACKGROUND Hybrid endovascular and open reconstructions are used increasingly often for multilevel revascularization for lower limb ischaemia. The aim was to evaluate outcomes after such procedures in a single-center non-randomized retrospective study. PATIENTS AND METHODS Consecutive patients with multilevel arterial disease who underwent single session hybrid procedures were analyzed depending on the type of ischaemia and the type of revascularization. RESULTS 164 patients were included with a median follow up time of 14 months (range: 0 - 70). Indication was claudication (group 1, 47 %), critical limb ischaemia (group 2, 33 %) and acute limb ischaemia (group 3, 20 %). Technical success rate was 99.3 %, perioperative mortality 2 %. Primary, assisted-primary and secondary patency rates at one year were 60 %, 61 % and 64 %, respectively. Primary, primary assisted and secondary patency were lower in group 2 and 3 compared to group 1 (all p < 0.05). Results were better when endovascular repairs were performed above compared to below the open repair site (all p < 0.05). Limb salvage at 1 year in groups 1 - 3 were 98 %, 92 % and 90 %, respectively. The risk of major amputation was highest in group 3 compared to group 1 (p = 0.001) or group 2 (p < 0.04). CONCLUSIONS The results depend on the type of ischaemia and the localization of endovascular procedures.

The role of hybrid procedures in the management of peripheral vascular disease.

This paper provides a summary of up-to-date information and experience with the combined treatment of patients suffering from peripheral arterial disease (PAD) with endovascular and open surgery, performed simultaneously and in a single operating room. Hybrid intervention is reported to have good results in well-indicated groups of patients with acute and chronic limb ischemia, even with older, high-risk patients. The indications for the use of this technique remain unclear with inconsistent opinions among vascular surgeons. The indications for treatment were divided into three main groups: 1) Patients with chronic limb ischemia, 2) acute limb ischemia, and 3) occlusion of a previous vascular reconstruction. The operating techniques for the most commonly used combinations are described. In conclusion, hybrid operating techniques are often useful when treating complex problems and multilevel disease in patients with chronic or acute lower limb ischemia. Modern vascular surgeons need to master both open and endovascular techniques, and to combine them in a creative fashion to the benefit of our patients.

Is carotid revascularization worthwhile in patients waiting for kidney transplantation

Renal failure and haemodialysis are associated with an increased risk of cardiovascular disease. Patients undergoing renal transplantation undergo rigorous pre-operative vascular assessment, including optimisation of risk factors for stroke. The indication for carotid intervention and the threshold for carotid endarterectomy in asymptomatic patients with incidental carotid disease has not been clarified in the context chronic kidney disease (CKD). This review aims to analyse outcomes following carotid endarterectomy in patients with CKD, in order to ascertain whether general guidelines for carotid artery revascularisation apply to this specific cohort. The current literature suggests that outcomes following internal carotid artery (ICA) revascularisation are worse in symptomatic and asymptomatic CKD patients compared to the non-CKD population. Consequently, asymptomatic patients with renal failure should be managed conservatively prior to renal transplantation, whilst those with symptomatic disease should be treated according to general guidelines but be informed of higher associated risk of stroke and death. Multidisciplinary optimisation remains essential in all patients waiting for potential renal transplantation.

Reply to ‘Cardiac remodeling after reduction of high-flow arteriovenous fistulas in end-stage renal disease: methodological issues’

Reply to ‘Cardiac remodeling after reduction of high-flow arteriovenous fistulas in end-stage renal disease: methodological issues’