Metformin Use and Long-term Clinical Outcomes in Kidney Transplant Recipients.

RATIONALE & OBJECTIVE: Metformin has been recommended for some patients with advanced chronic kidney disease. However, the value of metformin in kidney transplant recipients (KTRs) with pretransplant diabetes mellitus (DM) or posttransplant DM is uncertain. We investigated the clinical effects of metformin in KTRs. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: A total of 1,995 KTRs with diabetes from 6 tertiary referral centers in the Republic of Korea. EXPOSURE: Metformin usage was defined as the use of metformin for>90 days after kidney transplantation; 1,193 KTRs were metformin users, and 802 KTRs did not use metformin. Changing usage of metformin among those exposed for >90 days was also characterized. OUTCOME: Primary outcomes were all-cause mortality and death-censored graft failure (DCGF). Secondary outcomes were biopsy-proven acute rejection (BPAR) and lactic acidosis events. ANALYTICAL APPROACH: Survival analyses were conducted using multivariable Cox regression and competing risk analyses using Fine and Gray models. Changes in metformin use over time were modeled using a time-varying covariate. Metformin usage, mean daily dose, and hemoglobin A1c (HbA1c) changes were considered in the landmark analysis to address time-varying confounding. RESULTS: Metformin use was associated with a lower risk of DCGF (adjusted hazard ratio [AHR], 0.47 [95% CI, 0.23-0.96], P=0.038); there was no significant association with all-cause mortality (AHR, 0.94 [95% CI, 0.32-2.76], P=0.915) or BPAR (AHR 0.98 [95% CI, 0.62-1.54], P=0.942). In the subgroup analysis, metformin usage was associated with a reduced risk of all-cause mortality and a lower risk of DCGF for both pretransplantation DM and posttransplant DM groups. Metformin usage was associated with a lower risk of BPAR in the posttransplant DM group, although it was less effective in the pretransplantation DM group. There was no confirmed case of metformin-associated lactic acidosis (MALA) in the present cohort. A higher dose of metformin was correlated with lower risks of DCGF and BPAR. LIMITATIONS: Data on newer antidiabetic drugs such as SGLT2 inhibitors are limited, and there is potential limited generalizability to other populations. CONCLUSIONS: Metformin usage may benefit KTRs, as evidenced by its association with a reduced risk of DCGF and the absence of MALA events. Randomized controlled trials are needed to validate these observational findings.

Risk factors for Pneumocystis pneumonia with acute respiratory failure among kidney transplant recipients.

PURPOSE: One of the rare life-threatening fungal infections is pneumocystis pneumonia (PCP). Immunocompromised patients are the main vulnerable population. We investigate the risk factors associated with the development of severe PCP infection with acute respiratory failure after kidney transplantation. MATERIALS AND METHODS: This is a retrospective, single-center, case-control study. PCP patients who are kidney transplant recipients and required high-flow oxygen support or mechanical ventilation between March 2009 and February 2017 were included in the study. The comparison was conducted between the non-severe and severe PCP groups. To identify associated risk factors, we performed univariate and multivariate logistic regression. RESULTS: Among the total 2,330 kidney transplant recipients, 50 patients (2.1%) were diagnosed with PCP. Of these, 27 patients (54.0%) had severe PCP and 7 patients (14.0%) died, all of them were severe PCP patients. In the severe PCP group, the time from transplantation to PCP diagnosis (23.4 ± 24.9 months vs. 13.7 ± 9.9 months, p = 0.090) was insignificantly faster than in the non-severe PCP group. According to multiple logistic regression analysis, the significant risk factors associated with severe PCP were as follows, age (odds ratios (OR) 1.07; 95% confidence intervals (CI): 1.01-1.13; p = 0.027), time from transplantation to PCP diagnosis (odds ratios (OR) 0.92; 95% confidence intervals (CI): 0.86-0.99; p = 0.024), lymphopenia (OR 6.48; 95% CI: 1.05-40.09; p = 0.044), and history of acute rejection within 1 year (OR 8.28; 95% CI: 1.29-53.20; p = 0.026). CONCLUSION: Patients who have lymphopenia at the time of hospital admission or have been recently treated with acute rejection are more likely to progress to severe PCP, requiring intensive monitoring and aggressive treatment.

Post-operative recurrence of focal segmental glomerulosclerosis according to pre-transplant treatment after kidney transplantation.

BACKGROUND: Recurrent focal segmental glomerulosclerosis (FSGS) after kidney transplantation (KT) is a serious complication and a significant risk factor for graft failure. However, there is no clear evidence of the effectiveness of pre-transplant treatment using plasmapheresis (PP) or rituximab in preventing post-operative FSGS recurrence after KT. METHODS: This single-center retrospective study included 99 adult patients with biopsy-proven primary FSGS who underwent KT between 2007 and 2018. The patients were divided into the pre-treatment group (N = 53, 53.5%) and no pre-treatment group (N = 46, 46.5%). In the pre-transplant group, prophylactic PP was administered before KT in patients undergoing living donor transplantation and the day after KT in those undergoing deceased donor transplantation. RESULTS: The rate of immediate post-operative recurrence was significantly higher in the no pre-treatment group (16 [34.8%]) than in the pre-treatment group (5 [9.4%]; P = 0.002). There were three cases of graft failure due to recurrent FSGS, all of which were in the no pre-treatment group. After adjusting for possible confounding factors, age (per 10-year increase; OR = 0.61, CI, 0.42-0.90; P = 0.012) and pre-transplant treatment (vs. no pre-transplant treatment; OR = 0.17, CI, 0.05-0.54; P = 0.003) were identified as significant factors associated with FSGS recurrence. The rate of death-censored graft survival was significantly superior in the pretransplant treatment group (P = 0.042). CONCLUSION: Pre-transplant treatment with PP was associated with beneficial effects on preventing FSGS recurrence after KT.

Serum procalcitonin as a biomarker for differentiating between infectious and non-infectious fever after pancreas transplantation.

Laboratory biomarkers that can differentiate non-infectious fever from infectious fever after pancreas transplantation have yet to be discovered. Non-infectious fever was defined as the presence of fever (>38.3°C) in the absence of a documented clinical diagnosis of infection or a positive culture. Among 184 consecutive recipients, a total of 91 recipients developed fever within 1-month post-transplant, of whom 46 had infectious fever and 45 had non-infectious fever at our center between August 2014 and July 2019. The onset of fever was earlier in the non-infectious fever group (14.4 ± 3.7 post-transplant days) compared with the infectious fever group (16.5 ± 5.8 post-transplant days; p = .033). Multivariate analysis showed that serum procalcitonin at the peak of fever could significantly differentiate infectious fever from non-infectious fever (OR 53.378, 95% CI: 6.819-417.802, p < .001). The area under the curve for differentiating between the two groups was 0.853 (95% CI, 0.780-0.926) for procalcitonin and 0.667 (95% CI, 0.549-0.785) for CRP. The best cutoff values of serum procalcitonin and CRP were 0.405 ng/ml (sensitivity, 77.1%; specificity, 80.8%) and 7.355 mg/dl (sensitivity, 66.7%; specificity, 67.3%), respectively. Serum procalcitonin may be useful for differentiating non-infectious fever from infectious fever after pancreas transplantation.

Epidemiology and risk factors associated with Pneumocystis jirovecii pneumonia in kidney transplant recipients after 6-month trimethoprim-sulfamethoxazole prophylaxis: A case-control study.

BACKGROUND: Pneumocystis jirovecii pneumonia (PCP) is an important cause of morbidity and mortality in kidney transplant recipients (KTRs), and prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX) is recommended. The aim of this study was to investigate incidence and risk factors for PCP in KTRs after 6-month TMP-SMX prophylaxis. METHODS: We conducted a case-control study of patients with PCP who received 6-month PCP prophylaxis with TMP-SMX after kidney transplantation (KT). In cases of rejection, PCP prophylaxis was provided for six additional months after anti-rejection therapy. Cytomegalovirus (CMV) infection was not considered an indication for PCP prophylaxis due to concerns of nephrotoxicity associated with TMP-SMX. RESULTS: Among 3941 kidney or pancreas-kidney transplant recipients, 67 (1.7%) developed PCP after discontinuing TMP-SMX. A total of 47 patients with KT PCP and 94 controls were included. Duration of PCP prophylaxis was similar between cases and controls (median 6 months, P = .53). In multivariate analysis, rejection (OR 3.9; 95% CI 1.4-11.1) and CMV infection (OR 2.4; 95% CI 1.0-5.8) were independently associated with PCP development after TMP-SMX. Rejection or CMV infection was observed in 70% of patients with PCP. Time to PCP development after rejection (median [IQR] 6 [5-19] months) was slightly shorter than after CMV infection (median [IQR] 9 [5-12] months; P = .18). CONCLUSION: Post-prophylaxis PCP occurred in <2% of KTRs, and about two-thirds of these experienced rejection or CMV infection. These data suggest that at least 6 to 9-month additional chemoprophylaxis may be needed to prevent PCP in KTRs with transplant rejection or CMV infection.

Outcomes of arteriovenous access among cancer patients requiring chronic haemodialysis.

BACKGROUND: There are limited data focusing specifically on the types of arteriovenous (AV) access used and outcomes of AV access among cancer patients as a consequence of cancer. We aimed to describe outcomes of AV access among cancer patients requiring chronic haemodialysis, and also to compare outcomes between patients with and without cancer. METHODS: In this single-centre, retrospective, observational cohort study, 84 patients diagnosed with cancer before AV access placement were included; we analysed outcomes of AV access among these patients and compared these outcomes with our previous results. The study endpoints were AV access patency and early failure, defined as AV access abandonment within 12 months after AV access placement. RESULTS: Various cancer types, stages, and treatments were identified in our analysis. Autologous arteriovenous fistulas (AVFs) were used for 92.9% of this study population. Using our previous results for comparison, we found no significant difference in death-censored primary (P = 0.546) and secondary (P = 0.266) patency of AV access between patients with and without cancer; however, the rate of early AVF failure was statistically significantly higher among cancer patients (25.6% vs 13.9%; P = 0.008), and the most common cause of AVF failure was patient death. The rate of early failure was significantly higher among patients with advanced-stage cancer (59.1%) than among those with early-stage cancer (12.9%) (P <  0.001). CONCLUSIONS: Although AV access patency rates were similar among patients with and without cancer in the death-censored analysis, cancer patients were more prone to early AVF failure, mainly due to cancer-associated deaths, and this consideration needs to be carefully balanced against individual patients' life expectancies, according to cancer type and stage.

Pneumocystis pneumonia occurrence and prophylaxis duration in kidney transplant recipients according to perioperative treatment with rituximab.

BACKGROUND: Pneumocystis pneumonia (PCP) is a life-threatening fungal infection that can occur in kidney transplantation (KT) recipients. A growing number of KT recipients are receiving perioperative treatment with rituximab, which is associated with prolonged B-cell depletion and possible risk of PCP occurrence; however, the optimal prophylaxis duration according to rituximab treatment is yet unknown. We compared the occurrence of PCP and the duration of prophylaxis in KT recipients according to rituximab treatment. METHODS: We retrospectively analyzed 2110 patients who underwent KT between January 2009 and December 2016, who were divided into non-Rituximab group (n = 1588, 75.3%) and rituximab group (n = 522, 24.7%). RESULTS: In the rituximab group, the estimated number needed to treat (NNT) for prophylaxis prolongation from 6 to 12 months was 29.0 with a relative risk reduction of 90.0%. In the non-rituximab group, the estimated NNT value was 133.3 and the relative risk reduction was 66.4%. Rituximab treatment (hazard ratio (HR) = 3.09; P <  0.01) and acute rejection (HR = 2.19; P = 0.03) were significant risk factors for PCP in multivariate analysis. CONCLUSIONS: Our results suggest that maintaining PCP prophylaxis for 12 months may be beneficial in KT recipients treated with rituximab for desensitization or acute rejection treatment.

Relationship of Lower-extremity Deep Venous Thrombosis Density at CT Venography to Acute Pulmonary Embolism and the Risk of Postthrombotic Syndrome.

Background Acute deep venous thrombi (DVT) have higher Hounsfield unit values than chronic (bland) thrombi at CT venography. Purpose To determine the relationship between DVT thrombus density found on CT venography images to the presence of acute pulmonary embolism (PE) and the future risk of postthrombotic syndrome (PTS) in patients with DVT. Materials and Methods In this retrospective study, patients were divided into two groups: PE with DVT group and DVT-only group. Wells scores were recorded. Thrombus density ratios were calculated (DVT thrombus Hounsfield units/surrounding vein Hounsfield units). The presence or absence of PTS was determined from the results of the Venous Insufficiency Epidemiologic and Economic Study on Quality of Life (VEINES-QOL) questionnaires given to the patients with DVT. Statistical analyses used receiver operating characteristic curves and Spearman correlation analyses. Results Eighty-six patients were included; the mean age was 60 years ± 17 (51 men; PE with DVT group, 54 patients [63%]; DVT-only group, 32 patients [37%]). The mean thrombus density ratio was significantly higher in the PE with DVT group than in the DVT-only group (53.6% ± 12.4 [standard deviation] vs 42.8% ± 11.9, respectively; P < .001). At multivariable analysis, Wells score greater than 4 (odds ratio, 12.0; 95% confidence interval [CI]: 3.0, 47; P < .001) and higher thrombus density ratio (odds ratio, 1.1; 95% CI: 1.0, 1.2; P = .001) were independent predictors of PE. The diagnostic performance for the thrombus density ratio (area under the receiver operating characteristic curve, 0.74; 95% CI: 0.63, 0.85; P < .001) may be more discriminative than that of the Wells score (area under the receiver operating characteristic curve, 0.70; 95% CI: 0.59, 0.81; P = .002) for the presence of PE. In subgroup analysis, the thrombus density ratio and VEINES-QOL score were correlated (r = 0.61; 95% CI: 0.30, 0.80; P < .001). Conclusion Deep venous thrombosis (DVT) density ratio at CT venography was associated with acute pulmonary embolism in patients with lower-extremity DVT. © RSNA, 2019 Online supplemental material is available for this article.

Comparison of outcomes after carotid endarterectomy between type 2 diabetic and non-diabetic patients with significant carotid stenosis.

BACKGROUND: We aimed to compare early and late outcomes after carotid endarterectomy (CEA) between Korean type 2 diabetic and non-diabetic patients and to investigate the impact of diabetes on the overall incidence of cardiovascular events after CEA. METHODS: We retrospectively analyzed 675 CEAs, which were performed on 613 patients with significant carotid stenosis between January 2007 and December 2014. The CEAs were divided into a type 2 diabetes mellitus (DM) group (n = 265, 39.3%) and a non-DM group (n = 410, 60.7%). The study outcomes included the incidence of major adverse events (MAEs), defined as fatal or nonfatal stroke or myocardial infarction or all-cause mortality, during the perioperative period and within 4 years after CEA. RESULTS: Patients in the DM and non-DM groups did not differ significantly in the incidence of MAEs or any of the individual MAE manifestations during the perioperative period. However, within 4 years after CEA, the difference in the MAE incidence was significantly greater in the DM group (P = 0.040). Analysis of the individual MAE manifestations indicated a significantly higher risk of stroke in the DM group (P = 0.006). Multivariate analysis indicated that diabetes was not associated with MAEs or individual MAE manifestations during the perioperative period, whereas within 4 years after CEA, diabetes was an independent risk factor for MAEs overall (hazard ratio [HR], 1.62; 95% confidence interval [CI] 1.06-2.48; P = 0.026) and stroke (HR, 2.55; 95% CI 1.20-5.41; P = 0.015) in particular. CONCLUSIONS: Diabetic patients were not at greater risk of perioperative MAEs after CEA; however, the risk of late MAE occurrence was significantly greater in these patients. Within 4 years after CEA, DM was an independent risk factor for the occurrence of MAEs overall and stroke in particular.

New predictors of aneurysm sac behavior after endovascular aortic aneurysm repair.

OBJECTIVES: This study aimed to identify new predictors of sac behavior after endovascular aortic aneurysm repair (EVAR) and to investigate whether sac behavior is associated with long-term clinical outcomes. METHODS: A total of 168 patients undergoing successful EVAR for abdominal aortic aneurysms with CTA follow-up of at least 1 year were included. Predictors of aneurysm sac behavior and its impact on long-term clinical outcomes were retrospectively analyzed. RESULTS: According to sac behavior, eligible patients were stratified into the sac regression group (n = 79, 47.0%) and the sac non-regression group (n = 89, 53.0%). Patients in the regression group were younger (p = 0.036) and more likely to take sarpogrelate hydrochloride postoperatively (p = 0.011) than those in the non-regression group. The incidence of postimplantation syndrome (PIS) was significantly higher in the regression group (p = 0.005). On multivariate analysis, sac regression was more likely to occur in those with PIS (hazard ratio [HR], 1.68; 95% confidence interval [CI], 1.07-2.64; p = 0.023) and less likely to occur in those with transient type II endoleaks (HR, 0.43; 95% CI, 0.20-0.95; p = 0.037) and higher thrombus density within the sac on follow-up CTA (HR, 0.97; 95% CI, 0.95-0.99; p = 0.013). Non-regression of the sac was associated with significantly higher rates of re-intervention during the follow-up period (p = 0.001). CONCLUSIONS: In addition to type II endoleaks, PIS and thrombus density are new predictors of aneurysm sac behavior, and sac regression is significantly associated with lower rates of re-intervention. KEY POINTS: • After endovascular aortic aneurysm repair (EVAR), patients with sac regression were younger and more likely to take sarpogrelate hydrochloride postoperatively than those with sac non-regression. • The incidence of postimplantation syndrome (PIS) was significantly higher in patients with sac regression. • In our analysis, PIS and thrombus density within the sac were newly identified predictors of aneurysm sac behavior after EVAR.

The results of HLA-incompatible kidney transplantation according to pre-transplant crossmatch tests: Donor-specific antibody as a prominent predictor of acute rejection.

BACKGROUND: Crossmatching (XM) between organ donors and recipients is correlated with clinical outcomes. This study evaluates the results of HLA-incompatible kidney transplant (HLA-i KT) according to pre-transplant XM modalities. METHODS: This study included 731 consecutive patients. HLA-i KT was defined as a transplant under conditions of complement-dependent cytotoxicity (CDC) XM positivity, flow-cytometric XM (FCXM) positivity, and/or maximal donor-specific antibody (DSA) mean fluorescence intensity (MFI) ≥5000. RESULTS: The incidence of antibody-mediated rejection (AMR) within 1 year after transplant was significantly higher in the HLA-i group than in the HLA compatible (HLA-c) group (15 vs 9 patients, 14.2% vs 1.4%; P < 0.01). Multivariate analysis indicated that a DSA MFI ≥5000 (odds ratio [OR] = 2.63; 95% confidence interval [CI], 1.00-6.98; P = 0.05) was significantly associated with acute rejection (AR), whereas CDC (OR = 2.09; 95% CI, 0.55-7.99; P = 0.28) and FCXM positivity (OR = 2.07; 95% CI, 0.73-5.87; P = 0.17) were not. Similarly, DSA MFI ≥ 5000 (OR = 4.14; P = 0.02) was the only significant factor affecting the risk of AMR. CONCLUSIONS: Of the various XM tests, DSA MFI ≥5000 was the most prominent predictor of AR in patients undergoing HLA-i KT.

Effects of patient age on patency of chronic hemodialysis vascular access.

BACKGROUND: In this single-center, retrospective observational study, we assessed the long-term patency of vascular access (VA) after first VA placement to uncover independent risk factors associated with VA patency in Asian hemodialysis (HD) patients stratified by age. We also investigated factors associated with VA patency among older HD patients according to the type of VA in the overall study population. METHODS: The study period was from January 2011 to December 2013. A total of 651 chronic HD patients with confirmed first upper-extremity VA placement were enrolled, and their records were analyzed retrospectively. A total of 445 patients (68.4%) made up the nonelderly group (< 65 years), and 206 patients (31.6%) were in the elderly group (≥ 65 years). Study outcomes were defined as primary or secondary VA patency. RESULTS: Autologous arteriovenous fistula (AVF) was more common in the nonelderly group (P <  0.01). Kaplan-Meier curve survival analysis indicated that primary patency was longer in the nonelderly group (P <  0.01); secondary patency, however, was similar between groups (P = 0.37). The multivariate analysis of factors associated with primary VA patency revealed that increased age (hazard ratio [HR], 1.02; 95% confidence interval [CI], 1.01-1.03; P <  0.01) was associated with shorter primary patency, and AVF (HR, 0.38; 95% CI, 0.28-0.51; P <  0.01) was associated with longer primary patency. AVF (HR, 0.57; 95% CI, 0.37-0.87; P = 0.010) and diabetes mellitus (HR, 1.56; 95% CI, 1.07-2.29; P = 0.02) were independently associated with longer and shorter secondary patency periods, respectively; however, increased age was not a risk factor for decreased secondary patency. CONCLUSIONS: Increased age was associated with shorter primary patency but not secondary patency, whereas AVF placement was associated with longer primary and secondary patency. Considering the similar rates of secondary patency between groups and the superior patency of AVF compared to arteriovenous graft, a fistula-first strategy should be applied to appropriate older patients.

Intracranial aneurysms in patients receiving kidney transplantation for autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease, leading to kidney failure. One of the most serious extrarenal complications of ADPKD is comorbid intracranial aneurysms. The aim of this study is to evaluate the prevalence, rupture rate, and treatment outcomes of intracranial aneurysms in ADPKD. METHODS: Adult patients with a documented diagnosis of ADPKD who received kidney transplantation at our center from January 1994 to December 2018 were included in the study. Medical history, physical examination, laboratory findings, imaging studies, and operation records were collected and analyzed from our database. RESULTS: Among 154 kidney transplant recipients with ADPKD, 113 (73.4%) patients were screened for intracranial aneurysms preoperatively. Twenty three patients (14.9%) had intracranial aneurysms with mean diameter size of 4.5 ± 2.7 mm. Nine patients (5.8%) experienced aneurysm rupture and the mean age at time of rupture was 34.9 ± 9.3 years. Twelve patients (52.2%) presented with multiple aneurysms. The most common aneurysm location was the bifurcation of the middle cerebral artery (34.9%). Clipping was the most common treatment in both ruptured and unruptured aneurysms. CONCLUSIONS: Intracranial aneurysms are more frequent in patients with ADPKD, and the average age of intracranial artery rupture in patients with ADPKD is earlier than in the general population. It is necessary to consider proper evaluation and management of intracranial aneurysms when counseling ADPKD patients who will undergo kidney transplantation.

Impact of pretransplant donor-specific antibodies on kidney allograft recipients with negative flow cytometry cross-matches.

The Luminex test can detect low levels of donor-specific antibody (DSA) that cannot be detected by flow-cytometric cross-matching (FCXM) in kidney transplantation (KT). This study evaluated the impact of DSA on clinical outcomes in KT recipients negative on FCXM. Of 575 consecutive patients who underwent living donor KT between January 2013 and July 2016, 494 (85.9%) were DSA-negative and 81 (14.1%) were DSA-positive. Although rates of acute cellular rejection (ACR) at 1 year were similar in the 2 groups (P = .54), the incidence of antibody-mediated rejection (ABMR) was significantly higher in the DSA-positive group (P < .01). There was no statistically significant association between rejection-free graft survival (RFGS) rates and pretransplant class I DSA. However, evaluation of pretransplant class II DSA showed that RFGS rates were significantly lower in patients with mean fluorescence intensity (MFI) >3000 than in patients with DSA-negative (P < .01). On multivariate analyses, class II DSA MFI ≥5000 was a significant risk factor for acute rejection (hazard ratio, 7.48; P < .01). These findings suggested that pretransplant DSA alone did not affect graft survival in KT recipients without desensitization. However, class II DSA MFI >5000 was an independent predictor of acute rejection in DSA-positive patients.

Clinical Outcomes of Conservative Treatment in Patients with Symptomatic Isolated Spontaneous Renal Artery Dissection and Comparison with Superior Mesenteric Artery Dissection.

OBJECTIVES: The aims of this study were to report the clinical outcomes of conservative medical treatment in patients with symptomatic isolated spontaneous renal artery dissection (SRAD) and compare them with those of spontaneous superior mesenteric artery dissection (SSMAD). METHODS: This was a single centre, observational comparative study between SRAD and SSMAD. Data from a prospective visceral artery dissection registry were analysed retrospectively. Between June 2010 and December 2016, 23 consecutive patients with symptomatic isolated SRAD who initially received conservative medical treatment were included. The primary outcomes were the aggravation of dissection requiring intervention and dissection related mortality. To evaluate the prognosis of symptomatic isolated SRAD, the clinical outcomes of isolated SRAD were compared with those of symptomatic isolated SSMAD (n = 40) during the same study period. RESULTS: The primary outcome incidence was 39% (9/23) in patients with symptomatic isolated SRAD during the median follow up period of 20 months (range 0-63 months). The dissection related mortality rate was 17% (4/23), and the cause of death in all cases was an abrupt rupture of the dissecting aneurysm with significant true lumen stenosis. None of the patients without aneurysm or with true lumen occlusion had dissection related mortality. During the same study period, compared with the patients with symptomatic isolated SSMAD who initially received conservative medical treatment, the primary outcome incidence (39% vs. 10%, p = .009) and dissection related mortality rate (17% vs. 0%, p = .016) were statistically significantly higher in patients with symptomatic isolated SRAD. CONCLUSIONS: Although the present analysis involved only a small number of patients, it revealed that symptomatic isolated SRAD with dissection related aneurysm and true lumen stenosis is a potentially life threatening condition and that aggressive surgical or endovascular interventions should be considered in these patients, who are refractory to conservative medical treatment.

Impact of diabetes duration and degree of carotid artery stenosis on major adverse cardiovascular events: a single-center, retrospective, observational cohort study.

BACKGROUND: We aimed to investigate the impact of diabetes duration and carotid artery stenosis (CAS) on the occurrence of major adverse cardiovascular events (MACE) in patients with type 2 diabetes mellitus (T2DM) without clinical cardiovascular disease. METHODS: A total of 2006 patients with T2DM, without clinical cardiovascular disease, aged >50 years, and who underwent baseline carotid Doppler ultrasound screening with regular follow-ups at the outpatient clinic of our diabetes center, were stratified into four subgroups according to diabetes duration and CAS degree. The primary outcomes included the occurrence of MACE, defined as fatal or nonfatal stroke and myocardial infarction, and all-cause mortality. RESULTS: The difference in the MACE incidence was significantly greater in patients with a longer diabetes duration (≥10 years) and significant CAS (50-69% luminal narrowing) (p < 0.001). Analysis of individual MACE components indicated a trend towards an increased incidence of stroke (p < 0.001), parallel to a longer diabetes duration and significant CAS. In contrast, the risk of myocardial infarction was significantly higher in patients with a diabetes duration <10 years and significant CAS (p = 0.039). Multivariate regression analysis showed that patients with both a longer diabetes duration and significant CAS demonstrated additive and very high risks of MACE (hazard ratio [HR], 2.07; 95% confidence interval [CI] 1.17-3.66; p = 0.012) and stroke (HR, 3.38; 95% CI 1.54-7.44; p = 0.002). CONCLUSIONS: The risk of MACE is significantly greater in patients with T2DM, without clinical cardiovascular disease, who have both a longer diabetes duration and significant CAS, compared with those who have a shorter duration and/or nonsignificant CAS.

Management Strategy for Ureteral-Iliac Artery Fistula.

BACKGROUND: Ureteral-iliac artery fistula (UIAF) is a rare but a potentially life-threatening condition. In this study, we reported our results of UIAF treated by open surgical and endovascular treatment. METHODS: In this single-center, retrospective observational cohort study, we reviewed 6 consecutive patients who were diagnosed with a UIAF and received either open surgical or endovascular treatment based on the specific risk profile of each patient. RESULTS: All patients had an indwelling ureteral stent for a ureteral stricture, with an average ureteral stenting duration of 22 months (range, 1-74 months), and 2 patients had a history of endovascular treatment with stent grafts for UIAF. Contrast-enhanced computed tomographic angiography was positive in 4 patients. Blood and urine cultures were positive in 2 and 4 patients, respectively. Four patients, including 2 with previously failed endovascular treatment, received open surgical repair. The remaining 2 patients received either endovascular treatment with stent grafts or a hybrid procedure. During the mean follow-up period of 20.3 months (range, 6-29 months), there was no symptomatic recurrence of the UIAF. CONCLUSIONS: A multidisciplinary approach is highly preferable for treating potentially life-threatening UIAF. Endovascular treatment with stent grafts is currently recommended in selected patients whenever possible, but open surgical treatment is required in certain patients with enteric contamination, abscess, local sepsis, or previously failed endovascular treatment.

Clinical Outcomes of Cryopreserved Arterial Allograft Used as a Vascular Conduit for Hemodialysis.

This single center cohort study aimed to test the hypothesis that use of a cryopreserved arterial allograft could avoid the maturation or healing process of a new vascular access and to evaluate the patency of this technique compared with that of vascular access using a prosthetic graft. Between April 2012 and March 2013, 20 patients underwent an upper arm vascular access using a cryopreserved arterial allograft for failed or failing vascular accesses and 53 using a prosthetic graft were included in this study. The mean duration of catheter dependence, calculated as the time interval from upper arm access placement to removal of the tunneled central catheter after successful cannulation of the access, was significantly longer for accesses using a prosthetic graft than a cryopreserved arterial allograft (34.4 ± 11.39 days vs. 4.9 ± 8.5 days, P < 0.001). In the allograft group, use of vascular access started within 7 days in 16 patients (80%), as soon as from the day of surgery in 10 patients. Primary (unassisted; P = 0.314) and cumulative (assisted; P = 0.673) access survivals were similar in the two groups. There were no postoperative complications related to the use of a cryopreserved iliac arterial allograft except for one patient who experienced wound hematoma. In conclusion, upper arm vascular access using a cryopreserved arterial allograft may permit immediate hemodialysis without the maturation or healing process, resulting in access survival comparable to that of an access using a prosthetic graft.

Metformin increases survival in hormone receptor-positive, HER2-positive breast cancer patients with diabetes.

INTRODUCTION: Metformin use has recently been observed to decrease both the rate and mortality of breast cancer. Our study was aim to determine whether metformin use is associated with survival in diabetic breast cancer patients by breast cancer subtype and systemic treatment. METHODS: Data from the Asan Medical Center Breast Cancer Database from 1997 to 2007 were analyzed. The study cohort comprised 6,967 nondiabetic patients, 202 diabetic patients treated with metformin, and 184 diabetic patients that did not receive metformin. Patients who were divided into three groups by diabetes status and metformin use were also divided into four subgroups by hormone receptor and HER2-neu status. RESULTS: In Kaplan-Meier analysis, the metformin group had a significantly better overall and cancer specific survival outcome compared with non metformin diabetic group (P <0.005 for both). There was no difference in survival between the nondiabetic and metformin groups. In multivariate analysis, Compared with metformin group, patients who did not receive metformin tended to have a higher risk of metastasis with HR 5.37 (95 % CI, 1.88 to 15.28) and breast cancer death with HR 6.51 (95 % CI, 1.88 to 15.28) on the hormone receptor-positive and HER2-negative breast cancer. The significant survival benefit of metformin observed in diabetic patients who received chemotherapy and endocrine therapy (HR for disease free survival 2.14; 95 % CI 1.14 to 4.04) was not seen in diabetic patients who did not receive these treatments. CONCLUSION: Patients receiving metformin treatment when breast cancer diagnosis show a better prognosis only if they have hormone receptor-positive, HER2-positive tumors. Metformin treatment might provide a survival benefit when added to systemic therapy in diabetic patients.

Clinical outcomes of carotid endarterectomy in patients with carotid artery tandem lesions.

BACKGROUND AND PURPOSE: When carotid artery tandem lesions are present, the benefits of carotid endarterectomy (CEA) to reduce recurrent stroke remain uncertain. The present retrospective cohort study aimed to determine the clinical outcomes of CEA for carotid artery tandem stenosis that was diagnosed by contrast-enhanced magnetic resonance angiography. METHODS: Six hundred forty-seven consecutive patients underwent CEA between January 2001 and December 2010. Tandem stenosis, defined as a significant carotid bifurcation stenosis and identifiable stenosis of ≥50% of any downstream distal cerebral artery, was identified in 92 patients (14.2%) by contrast-enhanced magnetic resonance angiography. Patients with and without tandem stenosis were compared in terms of CEA outcomes. The primary end point was the composite of any stroke, myocardial infarction, or death during the periprocedural period or ipsilateral stroke within 4 years after CEA. RESULTS: Tandem stenosis did not associate with ipsilateral stroke during postoperative follow-up. The 2 groups did not differ in terms of estimated 4-year primary end point rates (8.7% versus 3.8%; P=0.07) or ipsilateral stroke-free (P=0.56), any stroke-free (P=0.89), or overall survival (P=0.41) rates. CONCLUSIONS: After diagnosis by contrast-enhanced magnetic resonance angiography, patients with and without tandem stenosis had similar rates of stroke and death.