A comparative analysis of clinical outcomes between conversion to mTOR inhibitor and calcineurin inhibitor reduction in managing BK viremia among kidney transplant patients.

BK virus-associated nephropathy (BKVAN) exerts a substantial impact on allograft survival, however, the absence of robust clinical evidence regarding treatment protocols adds to the complexity of managing this condition. This study aimed to compare the two treatment approaches. The study population consisted of patients who underwent kidney transplantation between January 2016 and June 2020 at two tertiary hospitals in Korea. Patients diagnosed with BK viremia were evaluated based on their initial viral load and the treatment methods. The 'Reduction group' involved dose reduction of tacrolimus while the 'Conversion group' included tacrolimus discontinuation and conversion to sirolimus. A total of 175 patients with an initial viral load (iVL) ≥ 3 on the log10 scale were evaluated within two iVL intervals (3-4 and 4-5). In the iVL 4-5 interval, the Reduction group showed potential effectiveness in terms of viral clearance without statistically significant differences. However, within the iVL 3-4 interval, the Reduction group demonstrated superior viral clearance and a lower incidence of biopsy-proven acute rejection (BPAR) than the Conversion group. The renal function over 12 months after BKV diagnosis showed no statistically significant difference. Reducing tacrolimus compared to converting to mTORi would be a more appropriate treatment approach for BK viral clearance in kidney transplantation. Further research is warranted in a large cohort of patients.

Optimum tacrolimus trough levels for enhanced graft survival and safety in kidney transplantation: a retrospective multicenter real-world evidence study.

BACKGROUND: The current study aimed to determine the optimal tacrolimus trough levels for balancing graft survival and patient safety following kidney transplantation. MATERIALS AND METHODS: We conducted a retrospective cohort study involving 11,868 kidney transplant recipients from five medical centers. The association between tacrolimus exposures (periodic mean trough level, coefficient of variability, time in therapeutic range) and composite allograft outcome (de novo donor specific antibody, biopsy-proven rejection, kidney dysfunction, and graft failure), as well as safety outcomes (severe infection, cardiovascular events, malignancy, and mortality) were assessed. Data were sourced from Clinical Data Warehouses and analyzed using advanced statistical methods, including Cox marginal structural models with inverse probability treatment weighting. RESULTS: Tacrolimus levels of 5.0-7.9 ng/mL and 5.0-6.9 ng/mL during the 2-12 month and 12-72 month post-transplantation periods, respectively, were associated with reduced risks of composite allograft outcomes. During the first post-transplant year, the adjusted hazard ratios (aHR) for composite allograft outcomes were: 0.69 (95% CI 0.55-0.85, P<0.001) for 5.0-5.9 ng/mL; 0.81 (95% CI 0.67-0.98, P=0.033) for 6.0-6.9 ng/mL; and 0.73 (95% CI 0.60-0.89, P=0.002) for 7.0-7.9 ng/mL (compared to levels ≥8.0 ng/mL). For the 6-year composite outcomes, aHRs were 0.68 (95% CI 0.53-0.87, P=0.002) for 5.0-5.9 ng/mL and 0.65 (95% CI 0.50-0.85, P=0.001) for 6.0-6.9 ng/mL. These optimal ranges showed reduced rates of severe infection (6 y), malignancy (6 y), and mortality (1 y). CONCLUSION: This multicenter study provides robust evidence for optimal tacrolimus trough levels during the periods 2-12 and 12-72 months following kidney transplantation.

A 20-Year Analysis of Ruptured Abdominal Aortic Aneurysm Outcomes and Associated Factors in Korea.

BACKGROUND: Unlike western countries, which have reported distinct decreases in incidence of ruptured abdominal aortic aneurysm (rAAA) over the last few decades, epidemiologic studies in Korea have not shown significant changes in incidence or mortality of rAAA. The purpose of this study was to analyze the changes in rAAA treatment outcomes and various associated risk factors over the past 2 decades. METHODS: A 20-year retrospective multicenter review for rAAA cases from the period of January 2000 to December 2020 was undertaken. Preoperative, intraoperative and postoperative clinical data were extracted for patients diagnosed with rAAA. For analysis, outcomes from the early era, defined as patients treated between January 1, 2000, and December 31, 2010, were compared with outcomes from the late era, defined as patients treated between January 1, 2011, and December 31, 2020. RESULTS: The total in-hospital mortality was 34.1% in the early era compared to 44.8% in the late era. Patients in the late era were older than those in the early era (75.2 ± 10.3 years vs. 70.3 ± 8.9 years; P = 0.009). Treatment with rAAA endovascular aneurysm repair increased from 2.3% in early to 13.8% in late era (P = 0.031). In the early era, more patients were operated by experienced surgeons than the late era (78.1% vs. 45.9%; P = 0.002). The emergency room to operating room time did not show improvement over the 20 years. CONCLUSIONS: The results indicate that mortality rate of rAAA in Korea has not changed over the last 2 decades. The study suggests the need for national preventive strategies, improved systemic coordination, and potential centralization of vascular services to enhance survival rates for rAAA.

Prediction of acute rejection in renal allografts using shear-wave dispersion slope.

OBJECTIVES: To evaluate the role of shear-wave dispersion slope for predicting renal allograft dysfunction. METHODS: We retrospectively reviewed 128 kidney transplant recipients (median age, 55 years [interquartile range, 43-62 years]; male, 68) who underwent biopsy for allograft evaluation from November 2022 to February 2023. Cortex and renal sinus fat stiffness and shear-wave dispersion slope were obtained at shear-wave elastography (SWE). Cortex-to-sinus stiffness ratio (SR) and dispersion slope ratio (DSR)-related clinical and pathologic factors were evaluated using multivariable linear regression analysis. We conducted univariate and multivariate analyses for multiparametric ultrasound (US) parameters for identifying acute rejection and calculated the area under the receiver operating curve (AUC) values. RESULTS: Of 128 patients, 31 (24.2%) demonstrated acute rejection. The SR value did not differ between patient groups (1.21 vs. 1.20, p = 0.47). Patients with acute rejection demonstrated a higher DSR than those without rejection (1.4 vs. 1.21, p < 0.01). Interstitial fibrosis and tubular atrophy grade (IFTA; coefficient, 0.11/grade; p = 0.04) and renal transplant and biopsy interval (coefficient, 0.00007/day; p = 0.03) were SR determinant factors, whereas only IFTA grade (coefficient, 0.10/grade; p = 0.01) for DSR. Multivariate analysis revealed mean resistive index (odds ratio [OR] 1.08, 95% confidence interval [CI] 1.02-1.14, p = 0.01) and DSR value (OR 16.0, 95% CI 3.0-85.8, p = 0.001) as independent factors for predicting acute rejection. An AUC of 0.74 for detecting acute rejection was achieved by combining the resistive index and DSR value. CONCLUSION: Shear-wave dispersion slope obtained at SWE may help identify renal allograft dysfunction. CLINICAL RELEVANCE STATEMENT: Acute rejection in renal allografts is a major cause of allograft failure, but noninvasive diagnosis is a challenge. Shear-wave dispersion slope can identify acute rejection non-invasively. KEY POINTS: • The interstitial fibrosis and tubular atrophy grade was a determinant factor for stiffness ratio and shear-wave dispersion slope ratio between cortex and renal sinus fat. • Shear-wave dispersion slope ratio between cortex and renal sinus fat could identify acute rejection in renal allografts. • A shear-wave dispersion slope has a potential to reduce unnecessary renal biopsy for evaluating renal allografts.

T cell posttransplant lymphoproliferative disorder after kidney transplantation progressing to acute liver failure: a case report.

Posttransplant lymphoproliferative disorder (PTLD) is a rare and serious complication of kidney transplantation (KT), with 85% of cases being of B cell lineage. We present a case of T cell PTLD (T-PTLD) that rapidly progressed to liver failure, septic shock, and death despite various therapeutic interventions. A 50-year-old woman underwent ABO- and human leukocyte antigen-compatible preemptive living donor KT for diabetic endstage kidney disease under basiliximab induction therapy. During routine monitoring, 2 months after KT, her Epstein-Barr (EB) viral load was found to be elevated to 318,443 copies/mL. Despite a reduction in maintenance immunosuppressants and preemptive rituximab treatment, the EB viremia continued to increase. Eight months after KT, abdominopelvic computed tomography revealed multifocal splenic lesions and nonspecific lymph node enlargement. Concurrently, the patient's liver function tests began to deteriorate without evidence of viral hepatitis infection. A liver biopsy confirmed the diagnosis of EB virus-associated T-PTLD with CD3 and CD56 expression. Only 2 months after the PTLD diagnosis, the patient developed acute and severe liver failure. She died 12 days after being hospitalized, despite the administration of rescue cytotoxic chemotherapy. This case exemplifies the challenges of managing refractory EB virus-associated T-PTLD after KT, for which no specific treatment options are currently available. Further research into preventative and therapeutic methods for T-PTLD is warranted.

Association of high intra-patient variability in tacrolimus exposure with calcineurin inhibitor nephrotoxicity in kidney transplantation.

Tacrolimus intra-patient variability (IPV) is a novel predictive marker for long-term kidney transplantation outcomes. We examined the association between IPV and calcineurin inhibitor (CNI) nephrotoxicity and the impact of pharmacogenes on CNI nephrotoxicity and IPV. Among kidney transplant recipients at our hospital between January 2013 and December 2015, the records of 80 patients who underwent 1-year protocol renal allograft biopsy and agreed to donate blood samples for genetic analysis were retrospectively reviewed. The cohort was divided into the low and high IPV groups based on a coefficient variability cutoff value (26.5%). In multivariate analysis, the IPV group was involved in determining CNI nephrotoxicity (HR 4.55; 95% CI 0.05-0.95; p = 0.043). The 5-year graft survival was superior in the low IPV group than in the high IPV group (100% vs 92.4% respectively, p = 0.044). Analysis of the time above therapeutic range (TATR) showed higher CNI nephrotoxicity in the high IPV with high TATR group than in the low IPV with low TATR group (35.7% versus 6.7%, p = 0.003). Genetic analysis discovered that CYP3A4 polymorphism (rs2837159) was associated with CNI nephrotoxicity (HR 28.23; 95% CI 2.2-355.9; p = 0.01). In conclusion, high IPV and CYP3A4 polymorphisms (rs2837159) are associated with CNI nephrotoxicity.

Analysis of Medication Errors Reported by Community Pharmacists in the Republic of Korea: A Cross-Sectional Study.

Background and objectives: We aimed to describe medication-related incidents or medication errors (MEs) reported by community pharmacists and analyze the prevalent medications involved. Materials and Methods: We extracted ME reports from databases comprising patient safety incidents reported to the Korean Pharmaceutical Association between January 2013 and June 2021. Medications were analyzed according to the second (therapeutic subgroup) and fifth (chemical substance) levels of the Anatomical Therapeutic Chemical classification. Results: A total of 9046 MEs were identified, most of which were near miss reports (88.3%). Among the errors that reached the patients (521 cases), harmful incidents accounted for 76.8%. Most MEs occurred during prescription (89.5%), while harmful MEs occurred mainly during dispensing (73.3%). In the prescription step, wrong drugs (44.8%), dosing errors (27.0%), and wrong durations (14.0%) were common. Anti-inflammatory and anti-rheumatic products (M01), drugs for acid-related disorders (A02), and antihistamines for systemic use (R06) were the most frequently reported medication classes involved. Harmful incidents were most common for dosing errors (31.0%) and wrong drugs (26.8%) and were common with warfarin, levothyroxine, and glimepiride. Conclusions: The MEs reported by community pharmacists were mainly prescribing errors, most of which were rectified before reaching patients. The prevalent medications involved in harmful errors include anti-diabetic, anti-thrombotic, and anti-inflammatory agents.

Venous Reconstruction in Extremity Soft Tissue Sarcoma Is Not Essential.

OBJECTIVE: Limb salvage is an important concern following complete oncologic resection for extremity soft tissue sarcoma (STS). Vascular reconstruction is essential for limb salvage. The purpose of this study was to evaluate the outcomes of vascular reconstruction in patients with extremity STS. METHODS: This is a retrospective, multi-center, case series of consecutive patients who underwent vascular reconstruction during extremity STS resection at 2 major centers in Korea. Demographics, reconstruction methods, type of conduit, surgical complications, graft patency, limb salvage rate, and patient survival were reviewed. RESULTS: From March 2005 to December 2020, 43 patients underwent vascular reconstructions during STS resection. Among the patients, 22 (51.2%) received arterial only, and 21 (48.8%) received simultaneous arterial and venous reconstructions. For the types of conduits, autologous saphenous veins (56.2%), artificial grafts (26.3%), and cryopreserved allografts (15.8%) were used. During a median follow-up of 23.8 months (interquartile range; 7.7-54.5), the overall primary patency of the reconstructed vessels was significantly higher in arteries than in veins (82.5% vs 56.3% at 12 months, P < .001). According to the type of conduit, the primary patency rate of autogenous vein seemed higher in venous reconstruction, however, there was no statistical significance in both arterial and venous reconstruction. There was no significant difference in primary arterial patency rate (P = .132) or incidence of surgical complications including postoperative edema or wound problem whether or not simultaneous venous reconstruction was performed with arterial reconstruction. The overall limb salvage rate and patient survival were 97.4%, 95.1%, and 89.4% and 91.9%, 81.7%, and 65.4% at 12, 24, and 36 months, respectively. CONCLUSIONS: Patency rates were poorer in venous reconstruction than in arterial reconstruction. In terms of arterial patency and postoperative complication, the role of simultaneous arterial and venous reconstruction seems not essential, however, it needs to be evaluated in future studies.

Outcomes of vein reconstruction using bovine pericardial patch.

BACKGROUND: The bovine pericardium is a good alternative material to the autogenous vein in vascular reconstruction. This study aimed to evaluate the results of angioplasty in venous reconstruction using bovine pericardium and identify the risk factors for significant complications. MATERIAL AND METHODS: A retrospective review was performed of the demographic data, clinical characteristics, and complications of patients who underwent vessel repair using bovine pericardium between February 2012 and December 2020. Univariate analysis was used to compare complication frequencies within several categories. RESULTS: There were 36 cases of patch angioplasty using bovine pericardium. The median age was 65 years; 61% of them were men. Of the 36 venous repairs, 31 (86.1%) were from cancer surgery and five (13.9%) were from iatrogenic injury. Patch shape was used in 27 cases (75.0%), while tube shape was used in nine cases (25.0%). The incidence of occlusion and partial thrombus was five (13.9%) and three (8.3%) cases, respectively. Of the nine tube-shaped angioplasties, four (44.4%) required reoperation due to early thrombosis (three cases) and hematoma (one case). CONCLUSION: The use of a bovine pericardial patch in the reconstruction of a damaged vein from tumor invasion or iatrogenic injury is feasible. However, the complication rate of vessel patency remains substantial, especially in cases of iatrogenic injury or when a tube-shaped form is used for repair.

The appearance of C1q deposition in transplanted kidney allografts and its clinical and histopathologic features.

Background: C1q nephropathy is an uncommon type of glomerulonephritis characterized by extensive and dominant C1q mesangial deposition in the absence of systemic lupus erythematosus. However, there are limited studies about C1q deposition in renal allografts. This study aimed to report the prevalence of C1q deposition in transplanted kidney allograft biopsies and describe its clinical and histopathologic features. Methods: Between January 2005 and December 2018, a total of 1,742 kidney transplantations were performed at Seoul National University Hospital. All renal allograft biopsies (n=10,217) of these patients were retrospectively screened for C1q deposition. C1q deposition was detected in the renal allograft biopsies of 104 patients (6.0%). Only 28 cases (1.6%) had intense (≥2+) C1q dominance and were reviewed in this study. Results: Among the 28 cases, only four (14.3%) had accompanying proliferative glomerulonephritis. Most did not have any other glomerular changes on light microscopy. No patients had nephrotic-range proteinuria at the time of biopsy. A follow-up biopsy was undertaken in 15 of the cases (53.6%). In these follow-up biopsies, C1q deposition either completely disappeared (n=13, 86.7%) or showed diminished staining (n=2, 13.3%). Conclusions: The prevalence of dominant or codominant C1q deposition in transplanted renal allograft biopsies was 1.6%. Most cases did not have any other accompanying glomerular changes. The follow-up biopsies of these allografts showed spontaneous disappearance or diminished staining of C1q deposition. These findings suggest that C1q deposition found in renal allografts is most likely clinically benign, although this possibility should be confirmed in further large-scale studies.

Dominant predictors of early post-transplant outcomes based on the Korean Organ Transplantation Registry (KOTRY).

Data for Asian kidney transplants are very limited. We investigated the relative importance of prognostic markers in Asian kidney transplants by using Korean Organ Transplantation Registry (KOTRY) cohort. Prediction models were developed by data-driven variable selection approach. The relative importance of the selected predictors was measured by dominance analysis. A total of 4854 kidney transplant donor-recipient pairs were analyzed. Overall patient survival rates were 99.8%, 98.8%, and 91.8% at 1, 3, and 5 years, respectively. Death-censored graft survival rates were 98.4%, 97.0%, and 95.8% at 1, 3, and 5 years. Biopsy-proven acute rejection free survival rates were 90.1%, 87.4%, and 87.03% at 1, 3, and 5 years. The top 3 dominant predictors for recipient mortality within 1 year were recipient cardiovascular disease history, deceased donor, and recipient age. The dominant predictors for death-censored graft loss within 1 year were acute rejection, deceased donor, and desensitization. The dominant predictors to acute rejection within 1 year were donor age, HLA mismatched numbers, and desensitization. We presented clinical characteristics of patients enrolled in KOTRY during the last 5 years and investigated dominant predictors for early post-transplant outcomes, which would be useful for clinical decision-making based on quantitative measures.

Effects of tacrolimus intrapatient variability and CYP3A5 polymorphism on the outcomes of pediatric kidney transplantation.

BACKGROUND: The intrapatient variability (IPV) of tacrolimus (Tac) is associated with the long-term outcome of kidney transplantation. The CYP3A single-nucleotide polymorphism (SNP) may affect the IPV of Tac. We investigated the impact of IPV and genetic polymorphism in pediatric patients who received kidney transplantation. METHODS: A total of 202 pediatric renal transplant recipients from 2000 to 2016 were analyzed retrospectively. The IPV was calculated between 6 and 12 months after surgery. Among these patients, CYP3A5 polymorphism was analyzed in 67 patients. RESULTS: The group with high IPV had a significantly higher rate of de novo donor-specific human leukocyte antigen antibodies (dnDSA) development (35.7% vs. 16.7%, p = .003). The high IPV group also had a higher incidence of T-cell-mediated rejection (TCMR; p < .001). The high IPV had no significant influence on Epstein-Barr virus, cytomegalovirus, and BK virus viremia but was associated with the incidence of posttransplant lymphoproliferative disorders (p = .003). Overall, the graft survival rate was inferior in the high IPV group (p < .001). The CYP3A5 SNPs did not significantly affect the IPV of Tac. In the CYP3A5 expressor group, however, the IPV was significantly associated with the TCMR-free survival rate (p < .001). CONCLUSION: The IPV of Tac had a significant impact on dnDSA development, occurrence of acute TCMR, and graft failure in pediatric patients who received renal transplantation. CYP3A5 expressors with high IPV of Tac showed worse outcomes, while the CYP3A5 polymorphism had no impact on IPV of Tac.

Flat Pattern Peaks of Tacrolimus Absorption and Associated Pharmacogenomic Variants in Kidney Transplantation Recipients.

BACKGROUND: Tacrolimus is the most commonly used immunosuppressive drug in solid organ transplantation. After administering a conventional twice-daily dose of tacrolimus, peak levels were achieved within the first 1.5 to 2 hours. A group of patients showed different early absorption phase of tacrolimus after kidney transplantation. METHODS: Trough(C0) and 1.5-hour blood levels (C1.5) of tacrolimus were measured in 95 kidney transplantation recipients. Patients with a C1.5/C0 < 1.5 and > 1.5 were defined as those having flat pattern peaks and as controls, respectively. Transplantation outcomes were compared between the groups. Whole exome sequencing was performed to investigate the genetic susceptibility to flat pattern peaks. RESULTS: Twenty-eight patients showed flat pattern peaks. The mean C1.5/C0 values were 1.13 ± 0.22 and 3.78 ± 1.25 in the flat pattern peak and control groups, respectively. In multivariate analysis, flat pattern peak was an independent risk factor for biopsy-proven acute rejection (BPAR) and/or borderline change (P = 0.014). Patients having flat pattern peaks showed significantly lower post-transplant 36-month estimated glomerular filtration rate (P = 0.001). Two single nucleotide variants in ABCB1 genes, rs1922242 and rs2235035, were associated with flat pattern peaks (P = 0.019 and P = 0.027, respectively). CONCLUSION: Both of C1.5 and C0 should be measured to distinguish the patients showing unique initial absorption. A C1.5/C0 ratio lower than 1.5 was associated with an increased risk of BPAR and/or borderline change. Single nucleotide variants s in ABCB1 gene might influence the flat pattern peaks of tacrolimus absorption.

Editor's Choice - Paclitaxel Coated Balloon Angioplasty vs. Plain Balloon Angioplasty for Haemodialysis Arteriovenous Access Stenosis: A Systematic Review and a Time to Event Meta-Analysis of Randomised Controlled Trials.

OBJECTIVE: A systematic review and meta-analysis of randomised controlled trials (RCTs) was performed to determine the effectiveness and safety of drug coated balloon (DCB) angioplasty compared with uncoated plain balloon (PB) angioplasty in treating arteriovenous access stenosis. METHODS: MEDLINE, Embase, Scopus, and the Cochrane Central Register of Controlled Trials were searched for RCTs comparing paclitaxel coated DCB and PB angioplasty for arteriovenous access stenosis. The last date of the literature search was 31 December 2020. Risk of bias of the retrieved studies was assessed with the Cochrane Collaboration tool for assessing risk of bias (RoB 2.0). The random effects model was used to estimate the risk of loss of target lesion patency (six and 12 months) and circuit patency (six and 12 months). Procedure related adverse events and mortality rate were also compared. Patency results were pooled using the time to event meta-analytical method and the quality of evidence was assessed according to the GRADE approach. RESULTS: Sixteen eligible trials, including 1 682 lesions, were included in the quantitative analysis for the efficacy and safety of paclitaxel coated DCBs. DCBs were associated with a lower risk of loss of target lesion patency at six months (HR 0.53, 95% CI 0.42 - 0.66) and 12 months (HR 0.60, 95% CI 0.47 - 0.76), and were also associated with improved six and 12 month circuit patency. Overall quality of evidence was moderate to low. Procedural complications were rare, and the risk of death up to 12 months was similar between the two groups (OR 1.03, 95% CI 0.68 - 1.56). CONCLUSION: Paclitaxel coated DCBs reduced the risk of loss of target lesion patency and circuit patency in arteriovenous access stenosis compared with PBs. Considering the heterogeneity of the included trials, there is a need to investigate optimal treatment regimens regarding drug dose and agent of the DCB and the treatment procedure.

Do Not Tunnel the Small Bowel during the Tunneling of a Femoro-Femoral Bypass.

A 62-year-old male with a history of femoro-femoral crossover bypass surgery 31 months previously presented with recurrent symptoms of fever and chills, along with a previous positive blood culture. Computed tomography showed vegetation in the bypass graft located in the peritoneal cavity, closely abutting the small bowel and soft tissue lesions in the right proximal thigh and distal calf. Under high suspicion of graft-enteric fistula with metastatic infection, surgery was performed to remove the previous graft and insert a new femoro-femoral bypass graft subcutaneously. Small bowel resection and anastomosis were also performed because the graft penetrated the small bowel mesentery and eroded into the small bowel. The patient had a patent graft without infection for more than 10 years. This case demonstrates the importance of tunneling in femoro-femoral crossover bypass free from the small bowel or other intraperitoneal organs.

Intravascular Fasciitis in the Femoral Vein with Hypermetabolic Signals Mimicking a Sarcoma: The Role of Preoperative Imaging Studies with Review of Literature.

Intravascular fasciitis (IVF) is a very rare disease that is difficult to diagnose preoperatively. Frequently, it can be misdiagnosed as a malignancy or deep vein thrombosis. A 26-year-old man presented with a 6-month history of intermittent cramping pain in the right calf. Duplex ultrasonography, computed tomography, magnetic resonance imaging, and positron emission tomography were performed in various hospitals. The work-up revealed a hypermetabolic mass in the femoral vein, suggestive of a malignancy, such as leiomyosarcoma. The tumor was located inside the femoral vein with no invasion, and the mass was resected en bloc with the vein wall. Intraoperative frozen section biopsy revealed no malignancy, and the final pathological diagnosis was IVF. Herein, we report a case of IVF and discuss the role of imaging studies in its preoperative diagnosis, with an extensive literature review.

Accelerating neovascularization and kidney tissue formation with a 3D vascular scaffold capturing native vascular structure.

Establishing an adequate vascularization of three-dimensional (3D) bioengineered tissues remains a critical challenge. We previously fabricated a vascular scaffold using the vascular corrosion casting technique, which provides a similar 3D geometry of native kidney vasculature. In this study, we functionalized the collagen vascular scaffold with a controlled release of vascular endothelial growth factor (VEGF vascular scaffold) to further promote vascularization. The VEGF vascular scaffold showed improved angiogenic capability in 2-dimensional (2D) and 3D in vitro settings. Implantation of the VEGF vascular scaffold seeded with human renal cells into a rat kidney demonstrated enhanced implant vascularization and reduced apoptosis of implanted human renal cells. Hybrid renal tubule-like structures composed of implanted human and migrated host renal cells were formed. This work highlights the critical role of early vascularization of the geometrically mimetic vascular scaffold using the VEGF incorporated vascular scaffold in reducing apoptosis of implanted cells as well as the formation of renal tissue structures.

Crucial Roles of Vascular Surgeons in Oncovascular and Non-Vascular Surgery.

OBJECTIVE: Vascular surgeons can be useful in non-vascular surgery cases, especially in oncology where complete resection is important. Such activity has been quantified at least locally, but maybe not adequately reported in a systematic manner, or studied prospectively. This study aimed to describe the roles of vascular surgeons in oncovascular surgery (OVS) and non-vascular surgery (NVS), and to analyse the yearly trends of consult surgery, early mortality and morbidity and risk factors for poor outcomes. METHODS: This study was a five year retrospective review of the role of vascular surgeons in various settings at a tertiary hospital. Electronic medical records and images were reviewed retrospectively. Between January 2014 and December 2018, the vascular surgery registry data of Seoul National University Hospital were reviewed for OVS or NVS assisted by vascular surgeons and operations primarily done by vascular surgeons. Demographic data, clinical characteristics, operative data, vascular related data and operative outcomes were collected. The operations were classified into primary surgery or consult surgery. Consult procedures were divided into planned or unplanned surgery. RESULTS: Of 564 cases, vascular surgeons performed 74 OVS as primary surgery, and retroperitoneal tumour was the most frequent diagnosis (n = 34). There were 490 intra-operative requests for a vascular surgeon's assistance, of which 109 were emergency calls. Total intra-operative consultations increased by 115.9% over five years, and the proportion of unplanned operations also increased. Unplanned assistance was most commonly requested for bleeding, whereas node dissection was the most common reason for planned surgery. The mortality rate was not different between the planned and unplanned surgery groups, but the latter showed worse outcomes in total operating time, length of hospital stay, post-operative consultations, and post-operative vascular related complications. CONCLUSION: Vascular surgeons have an essential role to play in the modern practice of cancer surgery. Oncovascular surgery enables gross resection of a tumour even in the presence of major vessel invasion. Emergency unplanned surgery had worse outcomes; therefore, pre-operative vascular consultation and multidisciplinary management are highly recommended for better patient outcomes.

Inconsistent Use of Terminology and Different Treatment Outcomes of Venous Adventitial Cystic Disease: A Proposal for Reporting Standards.

Adventitial cystic disease (ACD) is a very rare condition characterized by the accumulation of a cyst filled with gelatinous substance in the adventitia of a vessel adjacent to the joint area. The cyst usually compresses the vessel lumen, causing claudication or leg swelling. The disease usually affects the popliteal artery. However, several cases of venous ACDs particularly in the common femoral or external iliac vein have been reported. The definition, diagnosis, and optimal treatment of ACD remain controversial because of its rarity and the inconsistent use of terminology. The heterogeneity of the reported cases is more prominent in venous ACD. Herein, the accurate terminology of cysts correlated to the joint (synovial cyst, ganglion cyst, and adventitial cyst) and the pathogenesis, anatomy, and optimal therapy of venous ACD are discussed in detail to establish reporting standards for future studies.

Predictive Value of Abnormal and Borderline Ankle-Brachial Index for Coronary Re-Intervention and Mortality in Patients with Coronary Artery Disease: An Observational Cohort Study.

PURPOSE: This study aimed to investigate the abnormal and borderline ABIs for predicting coronary re-intervention and mortality in patients with coronary artery disease (CAD). MATERIALS AND METHODS: Data from a previous study were obtained and used to investigate the prevalence of peripheral arterial disease among Korean patients with CAD (n=285) in 2010. All patients underwent follow-up coronary angiography as scheduled (asymptomatic: 2-, 5-, and 7-month intervals) or as clinically indicated (symptomatic). RESULTS: In total, 33 patients had an abnormal ABI (ab-ABI: <1.0 or >1.4), and 252 had a normal ABI (nl-ABI: 1.0≤ABI≤1.4). The mean follow-up was 47 months. The mortality was significantly higher in the ab-ABI group than in the nl-ABI group (18.2% vs. 6.7%, P=0.0233). MACEs were significantly more common in the ab-ABI group (60.6% vs. 34.5%, P=0. 0036). Moreover, the ab-ABI group had a greater CAD progression than the nl-ABI group (48.5% vs. 31.3%, P=0.0496). The incidence of clinically indicated coronary re-intervention was significantly higher in the ab-ABI group than in the nl-ABI group (33.3% vs. 13.1%, P=0.0025). After adjusting for age, diabetes, dyslipidemia, dialysis, smoking, and obesity, the incidence of clinically indicated re-intervention was significantly higher in the ab-ABI group than in the nl-ABI group (HR, 2.80; 95% CI, 1.24 to 6.34). CONCLUSION: Abnormal and borderline ABI significantly increased the incidence of clinically indicated coronary revascularization and all-cause mortality during a 4-year follow-up among patients with CAD. Hence, ABI could be used to stratify extremely high-risk patients with CAD who may require aggressive surveillance or treatment.