The influence of metabolic syndrome on hemodialysis access patency

Factors associated with dysfunction of autogenous arteriovenous fistula in patients with secondary hyperparathyroidism after parathyroidectomy

BACKGROUND

Secondary hyperparathyroidism (SHPT) is a prevalent chronic complication in patients undergoing hemodialysis. Parathyroidectomy (PTX) is crucial for reducing mortality and improving the prognosis in the treatment of refractory hyperparathyroidism. However, it is often associated with a number of postoperative complications such as postoperative hypotension, hyperkalemia, and hungry bone syndrome. A previous study demonstrated that low blood pressure influences the patency of autogenous arteriovenous fistulas (AVF). Few studies have examined AVF dysfunction following PTX. This study aimed to identify and describe the risk variables associated with AVF dysfunction after PTX.

METHODS

Cases of AVF dysfunction after PTX between 2015 and 2021 were studied. Four controls were identified for each patient and were matched for sex and age. Biochemical parameters and blood pressure of the patients before and after PTX were recorded. Risk factors for AVF dysfunction after PTX were identified using conditional logistic regression analysis.

RESULTS

Sixteen patients and 64 controls were included in this study. Baseline demographic and laboratory data were compared. Patients in the AVF dysfunction group had lower levels of postoperative calcium than the controls. After surgery, calcium levels decreased more in patients with AVF dysfunction than in the control group. The decrease in systolic blood pressure (ΔSBP) after PTX was greater in the AVF dysfunction group than that in the control group. For each 1 mmHg increment in ΔSBP, the risk of AVF dysfunction after surgery increased by 11.6% (OR = 1.116, 95% CI, 1.005-1.239, p = .040). The likelihood of developing AVF dysfunction after surgery was twelvefold higher in diabetic patients than in non-diabetic patients (OR = 12.506, 95% CI, 1.113-140.492, p = .041). Among patients with ΔSBP > 5.8 mmHg after PTX, the AVF failure rate was significantly greater in patients with diabetes than in those without diabetes. Patients with a history of AVF failure had a nine-fold higher risk of developing AVF dysfunction (OR = 9.143, 95% CI, 1.151-72.627, p = .036). Serum albumin, hemoglobin, ΔiPTH, and age were not independent predictors of AVF dysfunction. The cutoff value for SBP was 5.8 mmHg, as determined by the Youden index of the receiver operating characteristic curve.

CONCLUSION

Decreased systolic blood pressure (ΔSBP) after PTX, diabetes, and AVF failure history were risk factors for AVF dysfunction following PTX in patients with SHPT. Diabetes patients with ΔSBP > 5.8 mmHg were more prone to AVF dysfunction after PTX.

The Effect of Obesity on Outcomes After Arteriovenous Fistulae Creation: A Systematic Review

BACKGROUND

Establishing reliable vascular access is critical for hemodialysis in end-stage renal disease (ESRD). In recent years, the global health burden of ESRD has grown, matched by a rise in prevalence of obesity. Currently, more and more arteriovenous fistulae (AVFs) are being created for obese patients with ESRD. This is a growing concern as creating arteriovenous (AV) access in obese ESRD patients can be more challenging and may be associated with poorer outcomes.

METHODS

We performed a literature search with multiple electronic databases. We included studies that compared outcomes after autogenous upper extremity AVF creation between obese and nonobese patients. The relevant outcomes were postoperative complications, outcomes related to maturation, outcomes related to patency, and outcomes related to reintervention.

RESULTS

We included 13 studies with a total of 305,037 patients. We found a significant association between obesity and poorer early and late AVF maturation. Obesity was also strongly associated with lower primary patency rates and a higher need for reintervention.

CONCLUSIONS

This systematic review found that higher body mass index and obesity are associated with poorer AVF maturation outcomes, poorer primary patency, and higher reintervention rates.

Comorbidities in patients with chronic hepatitis C and hepatitis B on hemodialysis

BACKGROUND AND AIM

Hemodialysis patients are at increased risk of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. Both HBV and HCV infections lead to risks of end-stage liver diseases and extrahepatic manifestations. This study aimed to investigate hepatic and extrahepatic comorbidities in hemodialysis patients with HBV or HCV infections compared with those without viral hepatitis.

METHODS

A total of 1910 hemodialysis patients, including 159 HCV viremic patients (HCV group), 217 seropositive for HBV surface antigen (HBsAg, HBV group) and 1534 seronegative for both anti-HCV and HBsAg (non-B and non-C [NBNC] group), from 23 hemodialysis centers were enrolled. Comorbidities were classified into 10 categories by the International Classification of Diseases-10th Revision.

RESULTS

Among the 1910 patients, the mean age was 64.6 years, and 52.7% were male patients. A total of 1834 (96%) patients had at least one comorbidity, and the mean number of comorbidities was 2.9 ± 1.5 per person. The three most common comorbidities were hypertension, diabetes, and ischemic heart diseases. The mean number of comorbidities per person was significantly higher in the HCV group (3.3 ± 1.7) than in the HBV (2.7 ± 1.5, P < 0.001) and NBNC groups (2.9 ± 1.5, P = 0.004), mainly due to the higher prevalence of ischemic heart disease, respiratory disorders, and mental/behavioral disorders. The HBV and NBNC groups exhibited comparable burdens of comorbidities.

CONCLUSIONS

Hemodialysis patients had a high prevalence of multiple comorbidities. Hemodialysis patients with HCV exhibited a higher burden of comorbidities, especially ischemic heart diseases, respiratory disorders, and mental/behavioral disorders, than HBV and NBNC patients did.

The Effect of Metabolic Syndrome on the Occurrence of Restenosis After Carotid Endarterectomy

OBJECTIVES

The metabolic syndrome (MetS) is a cluster of risk factors for cardiovascular disease. The effect of MetS on clinical outcome in patients with cerebrovascular disease remains largely unknown because conflicting results have been published. This study aimed to determine the influence of MetS on the occurrence of restenosis after carotid endarterectomy (CEA).

METHODS

All patients who underwent CEA between June 2003 and December 2014 in two tertiary academic referral centres in The Netherlands were included. MetS was defined if three or more of the following criteria were present: hypertension, obesity, high fasting serum blood glucose, high serum triglycerides, or low serum high density lipoprotein cholesterol. The primary outcome measure was the occurrence of ipsilateral restenosis after index surgery. The secondary outcome measure was (all cause) mortality during follow up. For the primary analysis, missing data were multiply imputed using multivariable imputation by chained equations. A Cox proportional hazards model was used to perform an adjusted analysis on the multiply imputed data sets.

RESULTS

A total of 1668 CEA procedures (in 1577 patients) were performed. The presence or absence of MetS could not be determined in 263 patients because of missing data. There was no significant difference in freedom from restenosis in the MetS group vs. the no-MetS group (hazard ratio [HR], 1.10; 95% confidence interval [CI] 0.98-1.23; p = .10) or in all cause mortality (HR 1.20; 95% CI 0.94-1.54; p = .14).

CONCLUSION

This study shows that MetS does not predict restenosis after CEA. Also, the presence of MetS did not influence patient survival negatively.

Local Adipose-Associated Mediators and Adaptations Following Arteriovenous Fistula Creation

Introduction

Local inflammation is an important regulator of vascular remodeling. We hypothesized that adipose tissue adjacent to hemodialysis arteriovenous fistulae modulates maturation.

Methods

During fistula creation, perivenous adipose was collected from 111 participants in the Hemodialysis Fistula Maturation Study. Nine adipose-associated mediators were measured. Duplex ultrasound was performed at 4 time points postoperatively from 1 day to first cannulation (10–26 weeks). Associations between logarithmically transformed biomarker levels and fistula remodeling were evaluated using mixed effects regression.

Results

Elevated interleukin (IL)-6 and monocyte chemoattractant protein (MCP)-1 were associated with a reduction in the fractional vein diameter during the early time frame of 1 day to 2 weeks (diameter change of 26.6% and 20.4% at the 25th and 75th percentile for IL-6, P = 0.01; 27.8% and 21.1% at the 25th and 75th percentile for MCP-1, P = 0.02), but not in later stages of remodeling. Local leptin levels showed a significant negative correlation with fractional venous flow increase between 2 and 6 weeks (percent flow change 31.4% and 11.3% at the 25th and 75th percentile for leptin, P = 0.03).

Conclusion

Thus, impaired fistula vein dilation and reduced capacity for flow augmentation associate with specific local adipose phenotypic signatures in a time-dependent manner. In view of adipose tissue plasticity, these findings raise the possibility of novel adipose-based strategies to facilitate fistula maturation.

Intradialytic Ultrafiltration Volume and Vascular Access Outcomes: A Japan Dialysis Outcomes and Practice Patterns Study Subanalysis

Introduction

The relationship between intradialytic ultrafiltration volume and vascular access (VA) patency remains unclear. Using data from the Japan Dialysis Outcomes and Practice Patterns Study, we analyzed whether large-volume ultrafiltration was associated with VA failure in hemodialysis patients.

Methods

We included 2736 patients for whom it was possible to evaluate VA patency and bodyweight change during dialysis. Patients were divided into three groups according to the tertile of intradialytic ultrafiltration by bodyweight: low, -9.5%-3.8%; middle, 3.8%-5.1%; and high, 5.1%-13.7%. Primary VA patency was defined as the time to first VA intervention, and secondary patency as the time to creation of a new VA. Hazard ratios for VA failure were compared across groups by using Cox regression models adjusted for age, sex, body mass index, diabetes, hemoglobin and phosphorus levels, Kt/V, and erythropoiesis-stimulating agent and antiplatelet use.

Results

For the low, middle, and high groups, the incidences of primary and secondary VA patency were 4.7, 5.6, and 6.7 events/100 person-years and 1.3, 1.6, and 1.7 events/100 person-years, respectively. Adjusted hazard ratios for primary VA patency in the middle and high groups versus the low group were 1.16 (95% confidence interval [CI], 0.88-1.52) and 1.41 (95% CI, 1.07-1.87), respectively; those for secondary VA patency were 1.29 (95% CI, 0.78-2.13) and 1.45 (95% CI, 0.86-2.45), respectively.

Discussion

Large-volume ultrafiltration during dialysis tended to increase VA failure in hemodialysis patients. We thus recommend smaller ultrafiltration volumes during hemodialysis to secure VA safely.

Preoperative dietary restriction reduces intimal hyperplasia and protects from ischemia-reperfusion injury

OBJECTIVE

Whereas chronic overnutrition is a risk factor for surgical complications, long-term dietary restriction (reduced food intake without malnutrition) protects in preclinical models of surgical stress. Building on the emerging concept that acute preoperative dietary perturbations can affect the body's response to surgical stress, we hypothesized that short-term high-fat diet (HFD) feeding before surgery is detrimental, whereas short-term nutrient/energy restriction before surgery can reverse negative outcomes. We tested this hypothesis in two distinct murine models of vascular surgical injury, ischemia-reperfusion (IR) and intimal hyperplasia (IH).

METHODS

Short-term overnutrition was achieved by feeding mice a HFD consisting of 60% calories from fat for 2 weeks. Short-term dietary restriction consisted of either 1 week of restricted access to a protein-free diet (protein/energy restriction) or 3 days of water-only fasting immediately before surgery; after surgery, all mice were given ad libitum access to a complete diet. To assess the impact of preoperative nutrition on surgical outcome, mice were challenged in one of two fundamentally distinct surgical injury models: IR injury to either kidney or liver, or a carotid focal stenosis model of IH.

RESULTS

Three days of fasting or 1 week of preoperative protein/energy restriction attenuated IH development measured 28 days after focal carotid stenosis. One week of preoperative protein/energy restriction also reduced plasma urea, creatinine, and damage to the corticomedullary junction after renal IR and decreased aspartate transaminase, alanine transaminase, and hemorrhagic necrosis after hepatic IR. However, exposure to a HFD for 2 weeks before surgery had no significant impact on kidney or hepatic function after IR or IH after focal carotid stenosis.

CONCLUSIONS

Short-term dietary restriction immediately before surgery significantly attenuated the vascular wall hyperplastic response and improved IR outcome. The findings suggest plasticity in the body's response to these vascular surgical injuries that can be manipulated by novel yet practical preoperative dietary interventions.

The Reasons for the Failure of the Primary Arteriovenous Fistula Surgery in Patients with End-Stage Renal Disease

Purpose

To analyze the reasons for the failure of the primary arteriovenous fistula surgery and explore preventive measures.

Methods

A total of 819 patients with end-stage renal disease were enrolled in the study. Autologous arteriovenous fistula surgery was performed on all patients. Their clinical data of hemoglobin (HB), albumin (ALB), cholesterol (CHOL), parathyroid hormone (PTH), blood glucose and blood pressure were collected before surgery, while the diameters of the radial artery and cephalic vein were measured by ultrasound.

Results

The operations in 742 patients were successful, but failed in 77 cases (accounting for 7.07%). The failure group was significantly older (61.3 ± 13.4 years) than the successful group (45.6 ± 11.2 years). The ratio of diabetes 36 (46.8%) and hypertension 20 (26.0%) was significantly higher in the failure group than in the successful group, respectively 235 (31.7%) and 145 (19.5%). The patients with blood pressure below 120/70 mm Hg had a higher risk of failed surgery (36.4%) than those with blood pressure above 120/70 mm Hg (9.16%). The cephalic vein and radial artery diameters were significantly smaller in the failure group (1.35 ± 0.64 mm, 2.13 ± 0.81 mm) than in the successful group (1.98 ± 0.47 mm, 2.47 ± 0.74 mm); the PTH levels in the failure group were significantly higher (782.39 ± 423.85) than in the successful group (378.83 ± 352.21).

Conclusions

The autogenous arteriovenous fistula surgery failure highly correlated with the patient's age, blood pressure, the primary disease and the vessel diameter. In addition, the PTH levels had a certain correlation with the failure of the fistula surgery.

Influência do diabetes mellitus sobre a perviedade da fístula arteriovenosa para hemodiálise

ResumoContextoA incapacidade das fístulas arteriovenosas (FAVs) atenderem aos quesitos mínimos para realização da hemodiálise (HD) corresponde a uma das maiores causas de morbidade nos pacientes em terapia renal substitutiva. Identificar os fatores de risco associados com a falência do acesso vascular é fundamental para o manejo e sucesso da terapia hemodialítica.ObjetivoComparar o tempo médio de patência e a sobrevida das fístulas arteriovenosas realizadas nos pacientes portadores de diabetes mellitus com pacientes não portadores de diabetes mellitus (DM) em HD.MétodosTrata-se de um estudo retrospectivo observacional, no qual foram observados os prontuários médicos de todos os pacientes em HD no Hospital Santa Casa de Misericórdia de Ponta Grossa, no período de fevereiro de 2014. Foram analisados dados clínicos referentes à confecção, manutenção e utilização das FAVs como adjuvante na terapia dialítica, comparando o tempo médio de patência das fístulas em uso para HD, bem como a sobrevida das FAVs ocluídas. Os pacientes selecionados foram divididos em dois grupos para comparação, conforme a presença ou ausência de DM.ResultadosOs indivíduos do Grupo DM apresentaram maior média de idade (59,97 ± 10,12), menor tempo de acompanhamento no serviço de hemodiálise (25,42 ± 21,03 meses), menor tempo médio até a oclusão da fístula arteriovenosa (9,03 ± 11,60 meses) e menor média de sobrevida dos acessos vasculares em 24 meses (50,25%).ConclusõesO estudo concluiu que para os pacientes diabéticos houve um menor tempo médio da patência das FAVs e menor taxa de sobrevida dos acessos em 24 meses.

Metabolic syndrome and outcome after breast reconstruction

Metabolic syndrome with its core components including obesity, insulin resistance, dyslipidemia and hypertension; is has been proven as a multiplex risk factor for cardiovascular disease. It is also recently shown by meta-analysis for its association with increased risk of common cancers including breast cancer. Multiple studies have shown metabolic syndrome prone to have poor perioperative outcome and complications for multiple type of surgery including vascular and flap surgery due to compromising microvascular circulation in this group of patient. However, lack of data on consequences of metabolic syndrome on breast cancer surgery as well as in breast reconstructive surgery indicate the need of further study in this area for the improvement of outcome of breast cancer and reconstructive surgery.

Chronic kidney disease predicts long-term mortality after major lower extremity amputation

Background:

Despite low peri-operative mortality after major lower extremity amputation, long-term mortality remains substantial. Metabolic syndrome is increasing in incidence and prevalence at an alarming rate in the USA.

Aim:

This study was to determine whether metabolic syndrome predicts outcome after major lower extremity amputation.

Patients and Methods:

A retrospective review of charts between July 2005 and June 2010.

Results:

Fifty-four patients underwent a total of 60 major lower extremity amputations. Sixty percent underwent below-knee amputation and 40% underwent above-knee amputation. The 30-day mortality was 7% with no difference in level (below-knee amputation, 8%; above-knee amputation, 4%; P = 0.53). The mean follow-up time was 39.7 months. The 5-year survival was 54% in the whole group, and was independent of level of amputation (P = 0.24) or urgency of the procedure (P = 0.51). Survival was significantly decreased by the presence of underlying chronic kidney disease (P = 0.04) but not by other comorbidities (history of myocardial infarction, P = 0.79; metabolic syndrome, P = 0.64; diabetes mellitus, P = 0.56).

Conclusion:

Metabolic syndrome is not associated with increased risk of adverse outcomes after lower extremity amputation. However, patients with chronic kidney disease constitute a sub-group of patients at higher risk of postoperative long-term mortality and may be a group to target for intervention.

Metabolic syndrome is associated with type II endoleak after endovascular abdominal aortic aneurysm repair

OBJECTIVE

Type II endoleak is usually a benign finding after endovascular abdominal aortic aneurysm repair (EVAR). In some patients, however, type II endoleak leads to aneurysm sac expansion and the need for further intervention. We examined which factors, in particular the components of metabolic syndrome (MetS), would lead to an increase risk of endoleak after EVAR.

METHODS

The medical records of all patients who underwent EVAR between 2002 and 2011 at the Veterans Affairs Connecticut Healthcare System were reviewed. MetS was defined as the presence of three or more of the following: hypertension (blood pressure ≥130 mm Hg/≥90 mm Hg), serum triglycerides ≥150 mg/dL, serum high-density lipoproteins ≤50 mg/dL for women and ≤40 mg/dL for men, body mass index ≥30 kg/m(2), and fasting blood glucose ≥110 mg/dL. Development of endoleak, including specific endoleak type, was determined by review of standard radiologic surveillance.

RESULTS

During a 9-year period, 79 male patients (mean age, 73.5 years), underwent EVAR for infrarenal abdominal aortic aneurysm (mean 6.2 cm maximal transverse diameter). MetS was present in 52 patients (66%). The distribution of MetS factors among all patients was hypertension in 86%, hypertriglyceridemia in 72%, decreased high-density lipoprotein in 68%, diabetes in 37%, and a body mass index of ≥30 kg/m(2) in 30%. No survival difference was found between the MetS and non-MetS groups (P = .66). There was no difference in perioperative myocardial infarction or visceral ischemia immediately postoperatively between the two groups. Patients with MetS had a significant increase in acute kidney injury (n = 7, P = .0128). Endoleaks of all types were detected in 26% (n = 20) of all patients; patients with MetS had more endoleaks than patients without MetS (35% vs 7.4%, P = .0039). Of the 19 type II endoleaks, 79% were present at the time of EVAR and only 21% developed during surveillance; 95% had MetS (P = .0007).

CONCLUSIONS

Type II endoleak after EVAR for abdominal aortic aneurysm is associated with MetS. Whether these patients are subject to more subsequent intervention due to sac expansion is unclear. MetS may be a factor to consider in the treatment of type II endoleak.

Metabolic syndrome is associated with type II endoleak after endovascular abdominal aortic aneurysm repair

OBJECTIVE

Type II endoleak is usually a benign finding after endovascular abdominal aortic aneurysm repair (EVAR). In some patients, however, type II endoleak leads to aneurysm sac expansion and the need for further intervention. We examined which factors, in particular the components of metabolic syndrome (MetS), would lead to an increase risk of endoleak after EVAR.

METHODS

The medical records of all patients who underwent EVAR between 2002 and 2011 at the Veterans Affairs Connecticut Healthcare System were reviewed. MetS was defined as the presence of three or more of the following: hypertension (blood pressure ≥130 mm Hg/≥90 mm Hg), serum triglycerides ≥150 mg/dL, serum high-density lipoproteins ≤50 mg/dL for women and ≤40 mg/dL for men, body mass index ≥30 kg/m(2), and fasting blood glucose ≥110 mg/dL. Development of endoleak, including specific endoleak type, was determined by review of standard radiologic surveillance.

RESULTS

During a 9-year period, 79 male patients (mean age, 73.5 years), underwent EVAR for infrarenal abdominal aortic aneurysm (mean 6.2 cm maximal transverse diameter). MetS was present in 52 patients (66%). The distribution of MetS factors among all patients was hypertension in 86%, hypertriglyceridemia in 72%, decreased high-density lipoprotein in 68%, diabetes in 37%, and a body mass index of ≥30 kg/m(2) in 30%. No survival difference was found between the MetS and non-MetS groups (P = .66). There was no difference in perioperative myocardial infarction or visceral ischemia immediately postoperatively between the two groups. Patients with MetS had a significant increase in acute kidney injury (n = 7, P = .0128). Endoleaks of all types were detected in 26% (n = 20) of all patients; patients with MetS had more endoleaks than patients without MetS (35% vs 7.4%, P = .0039). Of the 19 type II endoleaks, 79% were present at the time of EVAR and only 21% developed during surveillance; 95% had MetS (P = .0007).

CONCLUSIONS

Type II endoleak after EVAR for abdominal aortic aneurysm is associated with MetS. Whether these patients are subject to more subsequent intervention due to sac expansion is unclear. MetS may be a factor to consider in the treatment of type II endoleak.

Features of atherosclerosis in hemodialysis patients

Background

Cardiovascular disease is the main cause of mortality in dialysis patients. Carotid intima–media thickness (CIMT) is used as a surrogate marker of early atherosclerosis. Atherosclerosis can cause vascular access failure. The purpose of this study was to define the clinical features of atherosclerosis in hemodialysis patients based on CIMT and to define the relationship between CIMT and access failure.

Methods

In this cross-sectional study, the CIMT of 60 patients on hemodialysis was examined using B-mode Doppler ultrasonography between May 2012 and November 2012. Carotid atherosclerosis was defined as a CIMT≥0.9 mm or the incidence of atherosclerotic plaques.

Results

The patients’ mean age was 54.5±10.6 years, and 60% of the patients were male. The CIMT was 0.81±0.47 mm (range, 0.35–2.50 mm). The group with atherosclerosis was characterized by older age compared with those without atherosclerosis. Patients with atherosclerosis showed much shorter durations of access patency than their counterparts in the nonatherosclerosis group (hazard ratio, 2.822; 95% confidence interval, 1.113–7.156; P=0.029). Moreover, being overweight was associated with a 2.47-fold (95% confidence interval, 1.101–5.548) increased primary access failure.

Conclusion

This study shows that atherosclerosis is associated with older age. Patients who are overweight and have atherosclerosis may have shortened access patency.

The mouse aortocaval fistula recapitulates human arteriovenous fistula maturation

Several models of arteriovenous fistula (AVF) have excellent patency and help in understanding the mechanisms of venous adaptation to the arterial environment. However, these models fail to exhibit either maturation failure or fail to develop stenoses, both of which are critical modes of AVF failure in human patients. We used high-resolution Doppler ultrasound to serially follow mice with AVFs created by direct 25-gauge needle puncture. By day 21, 75% of AVFs dilate, thicken, and increase flow, i.e., mature, and 25% fail due to immediate thrombosis or maturation failure. Mature AVF thicken due to increased amounts of smooth muscle cells. By day 42, 67% of mature AVFs remain patent, but 33% of AVFs fail due to perianastomotic thickening. These results show that the mouse aortocaval model has an easily detectable maturation phase in the first 21 days followed by a potential failure phase in the subsequent 21 days. This model is the first animal model of AVF to show a course that recapitulates aspects of human AVF maturation.