Surgical Management, Prevention and Outcomes for Aneurysms of Arteriovenous Dialysis Fistulas: A Case Series Study and Review.

The escalating population of individuals afflicted with end-stage renal disease necessitates the provision of secure and efficacious vascular access for hemodialysis, with arteriovenous fistulas representing a preferred option. Nonetheless, the creation of dialysis fistulas may entail complications, including the occurrence of fistula aneurysms that may require surgical intervention. This study included eight patients with large aneurysms of dialysis fistulas and aimed to evaluate the safety and effectiveness of classic, endovascular, or hybrid methods for fistula reconstruction or ligation, depending on the indications. Vascular interventions were performed on patients on chronic hemodialysis and on those in whom hemodialysis was discontinued due to the proper functioning of the transplanted kidney. Performed procedures were considered safe and effective. The reconstructed fistulas provided the patients with patent vascular access, allowing for continued hemodialysis. No re-aneurysmal dilatation of the reconstructed or ligated fistulas was observed. Regular monitoring of dialysis fistulas is crucial to detect complications in time. Guidelines should be established to specify the dimensions at which fistula aneurysm should be excised and whether to remove asymptomatic aneurysms at all. For patients who have undergone kidney transplantation, outlines should indicate when the fistula should be preserved and when it should be ligated.

Clinical Characteristics and Predictors of Long-Term Prognosis of Acute Peripheral Arterial Ischemia Patients Treated Surgically.

BACKGROUND: Acute peripheral arterial ischemia is a rapidly developing loss of perfusion, resulting in ischemic clinical manifestations. This study aimed to assess the incidence of cardiovascular mortality in patients with acute peripheral arterial ischemia and either atrial fibrillation (AF) or sinus rhythm (SR). METHODS: This observational study involved patients with acute peripheral ischemia treated surgically. Patients were followed-up to assess cardiovascular mortality and its predictors. RESULTS: The study group included 200 patients with acute peripheral arterial ischemia and either AF (n = 67) or SR (n = 133). No cardiovascular mortality differences between the AF and SR groups were observed. AF patients who died of cardiovascular causes had a higher prevalence of peripheral arterial disease (58.3% vs. 31.6%, p = 0.048) and hypercholesterolemia (31.2% vs. 5.3%, p = 0.028) than those who did not die of such causes. Patients with SR who died of cardiovascular causes more frequently had a GFR <60 mL/min/1.73 m2 (47.8% vs. 25.0%, p = 0.03) and were older than those with SR who did not die of such causes. The multivariable analysis shows that hyperlipidemia reduced the risk of cardiovascular mortality in patients with AF, whereas in patients with SR, an age of ≥75 years was the predisposing factor for such mortality. CONCLUSIONS: Cardiovascular mortality of patients with acute ischemia did not differ between patients with AF and SR. Hyperlipidemia reduced the risk of cardiovascular mortality in patients with AF, whereas in patients with SR, an age of ≥75 years was a predisposing factor for such mortality.

Attitudes Toward and Knowledge of Brain Death and Deceased Organ Donation Among Anesthesiologists in the Northeastern Region of Poland.

BACKGROUND: Because in Poland transplant of organs from deceased donors is the predominant form of transplant, anesthesiology and intensive care specialists play a key role in the process. Insight into the work organization in intensive care units, anesthesiologists' and intensivists' level of knowledge and expertise, as well as personal opinions regarding declaring brain death and critical care of potential donors may be helpful in increasing transplant rates. AIM OF THE STUDY: The objective of this survey was to identify factors and challenges influencing donation rates in intensive care units of hospitals of various reference levels in region. METHODS: An anonymous, 31-question survey was sent to anesthesiology and intensive care specialists working in hospitals in one of the regions of eastern Poland. The survey was completed by 133 physicians, and a quantitative analysis was conducted on the data collected from submitted answers. RESULTS: The average age of responders was 46 years (±10.24 years). Anesthesiology and intensive care specialists made up 80.45% of respondents. A vast majority of respondents (97%) expressed positive attitude toward transplant and are willing to donate their organs after death (92.19%). Meanwhile, more than 50% of them admit their lack of sufficient knowledge when it comes to declaring brain death. More than 53% of surveyed physicians have never had the opportunity to participate in training in methodology in performing brain death provided by their hospital or know about such training taking place. A vast majority of respondents (94.76%) see the need for workshops in potential organ donor care and brain death determination and would like to attend them. CONCLUSIONS: This study shows a positive outlook toward organ donation and transplant but at the same time reveals a lack of knowledge and expertise among doctors working in intensive care units. That is why implementing education tools for identification, declaration, and maintenance of brain-dead donors could be one of the keys to enhancing donation.

Insulin-Like Growth Factor-Binding Protein 7 (IGFBP-7)-New Diagnostic and Prognostic Marker in Symptomatic Peripheral Arterial Disease?-Pilot Study.

The aim of our study was to evaluate the importance of insulin-like growth-factor-binding protein 7 (IGFBP-7) as a potential marker of symptomatic peripheral artery disease (PAD) occurrence. The study group consisted of 145 patients with diagnosed PAD, who qualified for the invasive treatment. The control group consisted of 67 individuals representing the local population and an ischemic heart disease (IHD) group of 88 patients after myocardial infarction or percutaneous coronary intervention. Patients with PAD had significantly higher IGFBP-7 concentrations than control group (1.80 ± 1.62 vs. 1.41 ± 0.45 ng/mL, p = 0.04). No significant differences between PAD patients and IHD patients were found (1.80 ± 1.62 vs. 1.76 ± 1.04 ng/mL, p = 0.783). Patients with multilevel PAD presented significantly higher IGFBP-7 concentrations than patients with aortoiliac PAD-median 1.18 (IQR 0.48-2.23) vs. 1.42 ng/mL (0.71-2.63), p = 0.035. In the group of patients who died or had a major adverse cardiovascular event (MACE) during six months of follow-up, a statistically significant higher IGFBP-7 concentration was found (median 2.66 (IQR 1.80-4.93) vs. 1.36 ng/mL (IQR 0.65-2.34), p = 0.004). It seems that IGFBP-7 is elevated in patients with atherosclerotic lesions-regardless of their locations. Further research should be conducted to verify IGFBP-7 usefulness as a predictor of MACE or death.

Plasmid Mediated mcr-1.1 Colistin-Resistance in Clinical Extraintestinal Escherichia coli Strains Isolated in Poland.

Objectives: The growing incidence of multidrug-resistant (MDR) bacteria is an inexorable and fatal challenge in modern medicine. Colistin is a cationic polypeptide considered a "last-resort" antimicrobial for treating infections caused by MDR Gram-negative bacterial pathogens. Plasmid-borne mcr colistin resistance emerged recently, and could potentially lead to essentially untreatable infections, particularly in hospital and veterinary (livestock farming) settings. In this study, we sought to establish the molecular basis of colistin-resistance in six extraintestinal Escherichia coli strains. Methods: Molecular investigation of colistin-resistance was performed in six extraintestinal E. coli strains isolated from patients hospitalized in Medical University Hospital, Bialystok, Poland. Complete structures of bacterial chromosomes and plasmids were recovered with use of both short- and long-read sequencing technologies and Unicycler hybrid assembly. Moreover, an electrotransformation assay was performed in order to confirm IncX4 plasmid influence on colistin-resistance phenotype in clinical E. coli strains. Results: Here we report on the emergence of six mcr-1.1-producing extraintestinal E. coli isolates with a number of virulence factors. Mobile pEtN transferase-encoding gene, mcr-1.1, has been proved to be encoded within a type IV secretion system (T4SS)-containing 33.3 kbp IncX4 plasmid pMUB-MCR, next to the PAP2-like membrane-associated lipid phosphatase gene. Conclusion: IncX4 mcr-containing plasmids are reported as increasingly disseminated among E. coli isolates, making it an "epidemic" plasmid, responsible for (i) dissemination of colistin-resistance determinants between different E. coli clones, and (ii) circulation between environmental, industrial, and clinical settings. Great effort needs to be taken to avoid further dissemination of plasmid-mediated colistin resistance among clinically relevant Gram-negative bacterial pathogens.

Estimation of V-POSSUM and E-PASS Scores in Prediction of Acute Kidney Injury in Patients after Elective Open Abdominal Aortic Aneurysm Surgery.

BACKGROUND: V-POSSUM and E-PASS scoring systems are usually used to predict morbidity and early mortality in surgical patients. We conducted this study to assess the validity of the V-POSSUM and E-PASS scores in predicting risk of acute kidney injury (AKI) development in patients undergoing elective open abdominal aortic aneurysm (AAA) repair. METHODS: We studied a consecutive series of 171 patients with AAA, qualified for elective open infrarenal repair. Patients underwent a thorough examination, and the physiological and surgical stress components of the V-POSSUM and E-PASS scores were calculated. The classification of patients in terms of postoperative AKI was performed in accordance with KDIGO criteria. RESULTS: AKI was recognized in 62 patients. In these patients, we found significantly higher physiological and surgical stress components of V-POSSUM and E-PASS scores in relation to patients without AKI. ROC analysis showed that the E-PASS score with a cutoff point ≥0.796 and the V-POSSUM score (morbidity) with a cutoff point ≥77.2% with sensitivity of 75.8% and 74.2%, respectively, and with specificity of 83.5% for both, identified patients with postoperative AKI. CONCLUSIONS: V-POSSUM and E-PASS scores have similar good properties in predicting postoperative AKI in patients undergoing elective open AAA repair.

Single center experience of subclinical rejections and BK nephropathies by kidney allografts' surveillance biopsies.

PURPOSE: Acute rejection of the kidney allograft remains the most important factor affecting the long-term graft outcome and is a major predictor of development of chronic damage and graft loss. Several studies have shown that early detection and treatment of subclinical rejection episodes may be beneficial for the graft outcome. The role of protocol (surveillance) biopsies and the value of donor specific antibodies (DSA) monitoring are still debatable. METHODS: This is a prospective observational study involving seventeen kidney recipients transplanted in north-eastern part of Poland who underwent "zero", 3-month and 12-month allograft biopsies as well as DSA assessment. RESULTS: Histologic analysis of the biopsies showed subclinical acute cellular rejection in 17.6% of patients (two tubulointerstitial, one vascular) at 3-months post transplantation, and additional case of borderline rejection at the 12-month point. Moreover, two cases (11.8%) of polyomavirus BK nephropathy were diagnosed (one at 3 and one at 12 month point). None of the patients developed de novo DSA. CONCLUSIONS: Our protocol biopsies allowed us to detect significant proportion of patients with subclinical, but histologically relevant acute cellular rejection and BK nephropathy. Early therapeutic intervention had beneficial effects in a 4-year follow up.

Use of short prosthesis segments for brachiocephalic arteriovenous fistulas in elderly hemodialysis population.

INTRODUCTION: The autogenous brachiocephalic fistula is a recognized secondary access for hemodialysis. However, veins in the antecubital fossa are often damaged, due to repeated venipunctures and subsequent scarring. Sometimes their anatomy does not enable successful arteriovenous fistula creation. In cases when the proximal part of the cephalic vein seemed patent, during ultrasound Doppler examination, we decided to use a short segment of 6 mm polytetrafluoroethylene graft to connect the vein with the brachial artery. We report our series of this procedure. MATERIAL AND METHODS: Over an 8-year period, 34 patients underwent such an operation. Grafts were anastomosed either to the end of the cephalic vein or to the side. The decision was made based on the vein condition: small-caliber veins were considered better for the end-to-side anastomosis. All procedures were performed under local anesthesia, and were well tolerated. RESULTS: Thirty-three fistulas were successfully cannulated at 2-8 weeks after the operation. Fistula patency rates were 84%, 73% and 55% at 12, 24 and 36 months. Comparison of two anastomosis types showed differences, 50% and 62.8% at 36 months, yet without statistical significance (p = 0.27, log-rank test). Fistula patency was not influenced by patient's age, sex or comorbidities. CONCLUSIONS: The described procedure provides satisfactory cumulative patency with an acceptable complication rate. It can enhance the number of cephalic veins used with its main advantages of simple surgical technique and low perioperative morbidity.

Basilic vein transposition in the forearm for secondary arteriovenous fistula.

Radiocephalic (RC) fistulae remain the first choice access for hemodialysis. The antecubital fossa is recommended as the next site. However, for some patients a basilic vein can be used to create an arteriovenous (av) fistula. We report a series of patients where the forearm basilic vein served as an alternative conduit for secondary procedures. Over an 8-year period, 30 patients who had a failed RC fistula underwent a basilic vein transposition. The immediate results were satisfactory. All fistulas were successfully cannulated. Cumulative patency was 93% after 1 year, 78% after 2 years, and 55% after 3 years. No ischemic or infectious complications were noted during the study period. The use of the forearm basilic vein to create a native av fistula appears to be a good alternative to procedures in the antecubital fossa or upper arm, thus preserving more proximal veins for future use.

To close or not to close: fistula ligation and cardiac function in kidney allograft recipients.

INTRODUCTION:  Arteriovenous fistulas are a preferred access for hemodialysis. Subsequent hemodynamic changes in systemic circulation may cause heart failure. The general conclusions that can be drawn from the few available studies are that high­flow fistulas causing symptomatic heart failure should be subjected either to reconstruction or ligation. However, it is still unclear whether a well­functioning fistula should be ligated after successful kidney transplantation. OBJECTIVES:  The aim of our study was to assess the effect of the fistula on heart function in patients after kidney transplantation. PATIENTS AND METHODS:  The study included 18 patients after kidney transplantation. Five patients underwent fistula ligation for esthetic reasons; 4 fistulas thrombosed shortly after transplantation. A group of 9 patients with a patent fistula was matched for age and sex. Heart function was assessed by physical examination and echocardiography. RESULTS:  The study group consisted of 6 women and 3 men, aged 32 to 64 years, with 6 forearm and 3 arm fistulas, and with hemoglobin levels ranging from 6.95 to 9.63 mmol/l. The control group consisted of 6 women and 3 men, aged 38 to 66 years, with 5 forearm fistulas and  hemoglobin levels ranging from 7.32 to 9.25 mmol/l. Control echocardiography was performed in each patient 3 months after fistula closure and did not reveal any significant differences compared with baseline examination. CONCLUSIONS:  Fistula ligation performed in a stable kidney allograft recipient does not seem to have a beneficial effect on cardiac function during short-term follow-up. Decision making should be cautious and balanced, because the creation of a new access may be extremely difficult and not always feasible.

[Arterio-venous fistula and cardiovascular system disturbances]. / Przetoka tqtniczo-zylna a zmiany w ukladzie kraienia.

There is an increasing number of patients with end-stage renal disease all over the world, mainly in the population of patients with diabetic nephropathy and in the elderly. One of the most important issues in nephrology care is the vascular access. The closest to the ideal vascular access is the native arterio-venous fistula. On the other hand, patients with end-stage renal failure are prone to cardiovascular complications, including left ventricular hypertrophy, cardiomyopathy, accelerated arterio- and atherosclerosis, vascular remodeling. Congestive heart failure is 20-fold more common than in the general population, and is found in about 30% of dialyzed patients, whereas left ventricular hypertrophy in 75%. Creating vascular access in patients with already established cardiovascular complications, may enhance the risk of exacerbation of cardiovascular complications with a negative effect on the patients' survival. The novel cardiovascular problems following vascular access creation may include: decompensation of congestive heart failure, pulmonary hypertension, inadequately low blood flow in the fistula with subsequent inadequate dialysis and fistula thrombosis, fistula infection (with local and systemic symptoms), and micro-inflammation (particularly in the politetrafluoroethylene grafts). The data concerning mutual relationship between vascular access and cardiovascular system in hemodialyzed patients are very scarce, mainly casual. In the review the updated status concerning the effects of vascular access creation on the cardiovascular system is presented.

Evaluation of urokinase-type plasminogen activator and its receptor in neointima of polyester vascular grafts.

The aim of the study was to assess the expression of urokinase-type plasminogen activator (uPA) and its receptor (uPAR) in neointima of polyester vascular grafts. Anastomotic areas were examined at 1, 4 and 12 months after prosthesis implantation in dogs, as well as in human vascular grafts. Immunohistochemistry was performed for uPA and uPAR. Graft neointima in dogs was positively stained for uPA with increased intensity at 4 and 12 months, whereas uPAR expression appeared at 4 and its intensity was increased at 12 months. Intensive uPA and positive uPAR labeling was shown in human grafts. The results demonstrated that in the early period of the healing process of polyester vascular grafts only uPA is present in the neointima in the region of the graft to adjacent artery anastomosis, whereas in healed grafts in dogs and humans uPAR is found as well.

Expression of fibrinolysis activators and their inhibitor in neointima of polyester vascular grafts.

The aim of the study was to evaluate dynamic changes in the expression of fibrinolytic system components in neointima forming in polyester vascular grafts. The study was carried out on 18 mongrel dogs divided into three groups, that underwent replacement of abdominal aorta with a polyester double velour prosthesis. Grafts were removed at 1, 4 and 12 months. The specimens were fixed according to AMeX method. Immunohistochemical labeling for von Willebrand factor (vWf), tissue plasminogen activator (t-PA), urokinase (u-PA), its receptor (u-PAR), plasminogen activator inhibitor type 1 (PAI-1) and D-dimer (DD) was performed. Increasing intensity of vWf expression on the graft luminal surface was found in successive periods of the study. A light positive t-PA and u-PA staining was shown in neointima at 1 month and its intensity was significantly increased at 4 and 12 months. Expression of u-PAR appeared at 4 months. A light positive PAI-1 and DD staining was demonstrated in neointima in all periods of the study. The results demonstrated increasing expression of fibrinolysis activators in neointima of polyester vascular grafts. Intensive expression of plasminogen activators, when compared to their inhibitor may reduce thrombotic properties of graft neointima particularly in the late period after prosthesis implantation.

Coagulation activators and inhibitors in the neointima of polyester vascular grafts.

The surface of synthetic vascular grafts is thrombogenic, which implies a risk for their occlusion. The aim of the study was to evaluate expression of coagulation components in the polyester vascular grafts neointima. The study was carried out on 18 dogs, which underwent replacement of the abdominal aorta with a polyester prosthesis. Grafts were removed after 1, 4 and 12 months. Immunohistochemical labeling for von Willebrand factor, tissue factor, factor XII, tissue factor pathway inhibitor, thrombomodulin, protein C, protein S and prothrombin activation fragment F1 + 2 was performed. Increasing intensity of von Willebrand factor expression was found in successive periods of the study. Factor XII was shown in the whole neointima after 1 month, whereas in the following periods its presence was limited to the luminal surface. Tissue factor expression was demonstrated after 1 month and its intensity increased in later periods. Tissue factor pathway inhibitor and thrombomodulin expression was demonstrated after 4 and 12 months. Protein C and protein S were present in all observation periods, as well as prothrombin activation fragment F1 + 2. Results indicate a high thrombotic potential of the graft neointima early after prosthesis implantation, whereas in the late postoperative follow-up increasing expression of coagulation inhibitors reduces thrombotic properties of the graft neointima.