BackgroundEarly graft function is a critical predictor of long-term outcomes in kidney transplantation. This study evaluated 10-year outcomes in patients with suboptimal graft function (SGF) during the first month after deceased donor kidney transplantation (DDKT).MethodsIn this retrospective study of 294 adult DDKT recipients (February 2006 - January 2014), SGF was defined as the lowest serum creatinine >1.5 mg/dL during the first month. Cases with a creatinine ≤1.5 mg/dL were categorized as the standard outcome group. Primary outcomes were 10-year graft and patient survival.ResultsSuboptimal graft function was associated with significantly poorer long-term graft survival (5-year: 82.3% vs. 92.7%; 10-year: 63.2% vs. 89.1%). Overall mortality did not differ between groups. Delayed graft function alone showed no significant association with graft survival. Donor age ≥ 60 years was also associated with inferior graft survival.ConclusionSuboptimal early creatinine elevation is a significant predictor of long-term graft outcomes. Donor age is an important determinant of long-term graft outcomes.

Purpose:This study was performed to predict individualized treatment strategies in ruptured abdominal aortic aneurysm (rAAA) by estimating the survival benefit of endovascular aneurysm repair (EVAR) and open surgical repair (OSR) based on anatomical and physiological features using a causal inference model. Methods:This retrospective study included 45 patients with de novo rAAA who underwent EVAR or OSR between 2012 and 2024. Thirty-three variables were analyzed. The model estimated individualized treatment effects (ITE) for 30-day survival. Model interpretability was assessed using Shapley Additive Explanations (SHAP) analysis. Five-fold cross-validation, receiver operating characteristic (ROC) analysis, and calibration plots were used for model evaluation. A clinical decision tree was developed to derive simplified decision rules. Results:The mean ITE was 0.22 ± 0.42, with 33% of patients classified as OSR-benefit candidates. SHAP analysis revealed that suprarenal angle, infrarenal angle, iliac anatomy, and proximal neck characteristics strongly influenced treatment effects. However, some predictors, such as low hemoglobin and systolic blood pressure favoring OSR, conflicted with clinical intuition. ROC analysis showed an area under the curve of 1.00, but calibration suggested overfitting due to a small sample size. Treatment-matched patients had a higher 30-day mortality rate than mismatched patients, suggesting potential bias or unmeasured confounding. The decision tree identified clinically relevant features but displayed structural inconsistencies and impractical cutoff values due to the limited sample size. Conclusion:The X-learner model demonstrated the feasibility of individualized treatment prediction in rAAA but suffered from overfitting and limited generalizability. Validation with larger multicenter cohorts is necessary to confirm clinical applicability.

Leiomyosarcoma (LMS) is a rare and aggressive smooth muscle tumor, and venous leiomyosarcoma (VLMS) is an uncommon subtype, with majority of the cases involving the vena cava. We report a case of a 56-year-old patient initially diagnosed as deep vein thrombosis (DVT) in the common femoral vein who was later diagnosed with primary VLMS originating from the deep femoral vein. Despite anticoagulation therapy, leg edema persisted and imaging studies revealed an intraluminal mass with increased extent and size. Initial duplex ultrasound suggested chronic DVT; however subsequent contrast-enhanced computed tomography and magnetic resonance imaging performed during follow-up demonstrated interval growth of an intraluminal mass, and positron emission tomography-computed tomography later confirmed metabolically active disease, leading to the diagnosis of VLMS. Surgical resection of the mass was performed, followed by reconstruction of the femoral vein using an expanded polytetrafluoroethylene graft. Histopathologic examination confirmed the diagnosis of LMS. The patient had an uneventful postoperative recovery and was referred for adjuvant therapy, including chemotherapy and radiotherapy. This case highlights the importance of a multimodal diagnostic approach in differentiating neoplasms from blood clots and underscores the need for a high level of suspicion when DVT presents with atypical features. Early diagnosis and wide surgical excision with the aim of achieving negative margins are essential for successful management of VLMS.

BACKGROUND:Rabbit antithymocyte globulin (rATG) is frequently used in immunologically high-risk kidney transplantation (KT), but its comparative effectiveness and safety vs basiliximab in ABO-incompatible (ABOi) KT are not well established. We aimed to compare outcomes of rATG and basiliximab induction in ABOi KT and to evaluate whether ABO compatibility modifies these associations. METHODS:We conducted a retrospective single-center cohort study of adult KT recipients at Seoul St. Mary's Hospital between 2011 and 2020. Patients receiving rATG or basiliximab induction were identified and stratified by ABO compatibility. Primary outcomes were overall patient survival, death-censored graft survival (DCGS), and rejection-free graft survival. Secondary outcomes included serious infection requiring hospitalization and post-transplant malignancy. Time-to-event analyses were performed using Kaplan-Meier methods and Cox proportional hazards models, with an interaction term between induction agent and ABO incompatibility. RESULTS:Among 1546 KT recipients, 285 underwent ABOi KT, including 69 receiving rATG and 216 basiliximab. In unstratified analyses, overall patient survival, rejection-free graft survival, and infection-related hospitalization did not differ significantly between induction strategies. Cytomegalovirus viremia was more frequent in the rATG group. In adjusted models, a significant interaction between induction strategy and ABO compatibility was observed for DCGS (P = .031), whereas no significant interactions were observed for rejection-free graft survival or overall patient survival. CONCLUSION:In ABOi KT, rATG induction was associated with improved DCGS compared with basiliximab, while patient survival and serious infectious complications were similar. The association between induction strategy and graft survival varied by ABO compatibility, supporting a risk-adapted approach to induction therapy.

BACKGROUND:Kidney transplantation (KT) is the preferred treatment for end-stage renal disease (ESRD) due to its advantages over dialysis. Although the benefits of preemptive KT are well established, the association between pre-transplant dialysis duration and post-transplant outcomes remains uncertain. OBJECTIVE:To evaluate the association between pre-transplant dialysis vintage and post-transplant outcomes in Korean KT recipients using real-world data from a tertiary transplant center. METHODS:We retrospectively evaluated 1,843 first KT recipients transplanted between 2006-2021. Dialysis duration was used as a categorical variable divided by tertiles according to distribution of time of analysis, and preemptive transplantation was categorized as a separate group. Primary outcomes included death-censored graft loss, all-cause mortality and composite outcomes. Survival was assessed using Kaplan-Meier and Cox proportional hazards models at a 95% confidence level. A deceased-donor KT (DDKT) subgroup analysis was also performed. RESULTS:369 patients underwent preemptive KT, and 1,474 dialysis-exposed recipients were categorized into tertile 1 (n = 492), tertile 2 (n = 491), and tertile 3 (n = 491), with mean pre-transplant dialysis durations of 1.2, 21.4, and 107.6 months, respectively. Compared with preemptive KT, all-cause mortality did not differ in the first or second tertiles but was significantly higher in the third tertile (aHR 3.55; 95% CI 1.43-8.81; p = 0.006). In the overall cohort, the third tertile was also associated with higher risks of death-censored graft failure and the composite outcome. However, in the deceased-donor KT subgroup, death-censored graft failure did not differ significantly across tertiles, and the composite outcome did not show a monotonic dose-response pattern. CONCLUSIONS:Prolonged pre-transplant dialysis was associated with a higher risk of all-cause mortality, whereas its association with graft failure was less consistent, particularly among deceased-donor KT recipients.

BACKGROUND:Ligation of iliac vessel lymphatics is essential for preventing lymphocele in kidney transplant (KT) recipients. Electrothermal bipolar vessel sealer (EBVS) such as LigaSure (Medtronic) may offer technical advantages. This study aimed to evaluate the safety and efficacy of lymphatic sealing using LigaSure in KT recipients compared to conventional hand-tie ligation. METHODS:A mixed prospective-retrospective cohort study was conducted at a single center. The 'hand-tie group' included data collected from 300 KT recipients transplanted between May 2017 and May 2020 using hand-tie lymphatic ligation. The "LigaSure group" included 100 patients prospectively enrolled and transplantation done between April 2023 and December 2024 during which retroperitoneal dissection was done using LigaSure. Outcomes included postoperative drain volume, retroperitoneal dissection time, operation time, transfusion requirements, lymphocele formation, and bleeding complications. RESULTS:Retroperitoneal dissection time was significantly shorter in the LigaSure group compared to the hand-tie group (34.5 ± 12.4 vs 45 ± 19.3 minutes, p < .001). While the LigaSure group had slightly higher drain output volume, the difference was not clinically significant. However, the LigaSure group required more frequent Viscum album extract injections (p < .001). Lymphocele requiring intervention was observed in one patient in the LigaSure group and 2 patients in the hand-tie group. Postoperative hemoglobin levels were significantly lower in the LigaSure group, while transfusion rates and bleeding-related interventions did not differ significantly. CONCLUSION:Using LigaSure is safe in terms of bleeding control and lymphocele prevention and can effectively shorten the retroperitoneal dissection time during kidney transplantation compared to the hand-tie technique.

Purpose:We aimed to evaluate health-related quality of life (HRQoL) in intestinal failure (IF) patients after different modes of intestinal rehabilitation. Methods:HRQoL was assessed using the generic 36-item Short Form Survey (SF-36, ver. 2) and visual analogue scale (VAS) in 6 different areas: diet, sleep, gastrointestinal (GI) symptoms, diarrhea, musculoskeletal pain, and other symptoms. Results:Twenty-two patients completed the questionnaires, of which 7 had received intestinal transplant (ITx), 9 were continuing home total parenteral nutrition (HPN), and 6 had tapered off total parenteral nutrition (TPN). SF-36 physical component summary scores were highest in the ITx group (median, 65.6; interquartile range [IQR], 31.6-80.3) compared to the HPN (median, 48.4; IQR, 44.7-66.3) or tapered group (median, 54.2; IQR, 45.2-61.6). Mental component summary scores were lowest in the ITx group (median, 48.8; IQR, 37.1-63.6), compared to the TPN (median, 60.2; IQR, 41.6-78.5) or tapered group (median, 51.0; IQR, 48.8-56.0). Differences were not significant in all items of the SF-36. VAS scores showed that patients in the ITx group showed the best results in diet (0.9), gastrointestinal (GI) symptoms (1.4), and musculoskeletal pain (2.4). There was a significant difference in sleep (P = 0.036), with the ITx (1.43) and HPN groups (1.33) showing better outcomes compared with the tapered group (4.67). Patients in the tapered group showed the least favorable results in all performance areas, except GI symptoms. Conclusion:SF-36 did not show a significant difference between the ITx, HPN, and tapered groups, but VAS showed a significant difference in sleep between groups. Further studies, including serial data, will allow a better understanding of the effects of different modes of intestinal rehabilitation.

INTRODUCTION:In patients with end-stage renal disease, kidney transplantation is the most recommended option for renal replacement therapy. However, due to the shortage of donor kidneys, the use of marginal kidneys has increased, leading to a higher incidence of delayed graft function (DGF). This study aimed to evaluate the effects of DGF and its duration on kidney transplantation outcomes. METHODS:A total of 1903 patients who underwent kidney transplantation between 2005 and 2020 were analyzed. DGF was defined as the need for dialysis within the first week after transplantation. Propensity score matching was used to ensure a balanced comparison between patients with DGF and those without DGF. Patients were further categorized based on the duration of DGF (group A': postoperative day 0-13, group B': postoperative day 14-). Graft survival was compared between these groups. RESULTS:Diabetes mellitus, predialysis duration, kidney weight, and the duration of DGF were identified as significant risk factors for graft failure. The 10-year graft survival rate among all patients with DGF was 58.8%. When stratified by DGF duration, the 10-year graft survival rate was 85.4% in the no DGF group, 68.5% in group A', and 31.3% in group B'. CONCLUSION:This study confirms that both the presence and prolonged duration of DGF adversely affect graft outcomes, particularly when dialysis is required for more than 14 days after transplantation.

BACKGROUND The optimization of tacrolimus dosing during the early postoperative hospitalization period is essential to prevent rejection, minimize nephrotoxicity, and minimize the risk of opportunistic infections. Patient pharmacokinetic variability poses challenges in dose adjustment. This study aimed to evaluate tacrolimus dosing optimization using machine learning and statistical methods. MATERIAL AND METHODS We conducted a retrospective study of 749 kidney transplant recipients at Seoul St. Mary's Hospital between January 2015 and December 2019. Data on tacrolimus doses, trough levels, and other clinical variables were collected and analyzed during the first 12 postoperative days of hospitalization. Three approaches were evaluated: Extreme Gradient Boosting (XGBoost), Elastic Net regression (EN), and Linear regression (LR). The models were trained and validated using 5-fold cross-validation, with performance assessed using R² errors and alignment with clinically acceptable error margins. RESULTS Elastic Net showed the best performance with R² (Coefficient of Determination) of 0.861±0.044 and RMSE (Root Mean Square Error) of 0.930±0.220. Linear Regression and XGBoost provided clinically relevant predictions but with slightly lower accuracy. External validation was not performed, limiting the generalizability of the results. CONCLUSIONS The Elastic Net is a practical and reliable model for predicting the optimal tacrolimus dose. Machine learning and statistical methods are useful tools for optimizing tacrolimus dosing during hospitalization after kidney transplantation. Future studies should incorporate multi-center validation to improve clinical applicability.

INTRODUCTION:While most recipients of living donor kidney transplantation experience rapid recovery of renal function, a subset shows suboptimal recovery of graft function despite sufficient postoperative time. The long-term implications of this suboptimal recovery of graft function remain unclear. This study aimed to assess the long-term outcomes of patients with suboptimal renal function 1-month post-transplantation. METHODS:This retrospective cohort study analyzed 411 living donor kidney transplant recipients at a single center from January 2006 to February 2014, with a mean follow-up of 11.3 years. Patients were categorized into 2 groups based on 1-month post-transplant serum creatinine: suboptimal (>1.2 mg/dL) and standard (≤1.2 mg/dL). Clinical, immunological, and donor-recipient variables were compared. Primary outcomes included acute rejection, graft survival, and patient survival. Kaplan-Meier and log-rank analysis were used for outcome assessment. RESULTS:The suboptimal group comprised 84 patients (20.4%). They were younger, predominantly male, had higher body mass index, and more frequently received smaller grafts from older donors with lower donor-to-recipient weight ratios. Acute rejection within 1 month occurred more frequently in this group (8.3% vs. 1.8%, P = .007). Despite these differences, no significant differences were observed in graft failure, mortality, infections, or malignancies, and long-term graft or patient survival did not differ significantly between the suboptimal and standard groups. CONCLUSIONS:Suboptimal graft function at 1-month post-transplantation is associated with increased acute rejection but does not independently predict inferior long-term graft or patient survival. These findings suggest that long-term outcomes can be preserved despite suboptimal functional recovery.

INTRODUCTION:Currently, there are two types of percutaneous arteriovenous fistula (pAVF) formation systems approved by the FDA: Ellipsys and WavelinQ. Although these systems are already in use in Europe or the United States, they have not been approved for use in Korea yet. For this reason, this study aimed to check anatomical feasibility of these systems for Korean population prior to their actual use. METHODS:Consecutive patients who received ultrasound vein mapping for arteriovenous fistula formation from June 2021 to June 2022 were included. The anatomical feasibility of each system was confirmed according to the manufacturer's instructions for use (IFU). RESULTS:Upper extremity ultrasonography was performed for a total of 83 patients to determine their feasibility for pAVF formation. Of these patients, 65.1% were feasible for pAVF formation with appropriate deep communicating vein (DCV) and outflow. Among them, 57.8% were feasible for the Ellipsys system and 54.2% were feasible for the WavelinQ system. Most patients who were infeasible for pAVF formation had a DCV of small size. Ulnar vessels were more suitable than radial vessel for WavelinQ (54.2% vs 33.7%, P-value = .012). The most common reason for not meeting the criteria was a small vein size at the access site. CONCLUSIONS:More than half of all patients were feasible for pAVF formation in this study. Ellipsys had a higher feasibility than WavelinQ, although they showed no significant difference in the feasibility. If these devices are imported into Korea, it will be a good opportunity for many patients to reduce the surgical burden and create AVFs more easily through these procedures.

Background: Living donor kidney transplantation (LDKT) is a crucial treatment for end-stage renal disease, with pre-emptive LDKT (transplantation before dialysis initiation) offering significant benefits in graft function and patient survival. The selection of a vasopressor during LDKT, particularly between norepinephrine and dopamine, and its impact on renal arterial hemodynamics measured using the renal arterial resistive index (RARI) is poorly understood. Methods: This retrospective observational cohort study enrolled 347 eligible pre-emptive LDKT recipients from the Seoul St. Mary’s Hospital between January 2019 and June 2023. Utilizing propensity score matching (PSM), the patients were categorized into dopamine and norepinephrine groups to compare the effects of these vasopressors on the intraoperative RARI, postoperative estimated glomerular filtration rate (eGFR), and hourly urine output. The RARI was measured via the Doppler ultrasonography of the renal hilum and parenchyma post-graft vascular and ureteral anastomoses. Results: The preoperative differences in the recipients’ and donors’ characteristics were mitigated following PSM. The dopamine group exhibited higher intraoperative RARI values at the renal hilum (0.77 ± 0.11 vs. 0.66 ± 0.13, p < 0.001) and parenchyma (0.71 ± 0.1 vs. 0.6 ± 0.1, p < 0.001) compared to those of the norepinephrine group. However, these differences were not statistically significant on postoperative day 7. The norepinephrine infusion adjusted for the propensity scores was associated with significantly lower odds of an RARI > 0.8 (hilum: OR = 0.214, 95% CI = 0.12–0.382, p < 0.001; parenchyma: OR = 0.1, 95% CI = 0.029–0.348, p < 0.001). The early postoperative outcomes showed a higher eGFR (day 1: 30.0 ± 13.3 vs. 25.1 ± 17.4 mL/min/1.73 m2, p = 0.004) and hourly urine output (day 1: 41.8 ± 16.9 vs. 36.5 ± 14.4 mL/kg/h, p = 0.002) in the norepinephrine group. Furthermore, the long-term outcomes were comparable between the groups. Conclusions: Norepinephrine infusion during pre-emptive LDKT is associated with more favorable intraoperative renal arterial hemodynamics, as evidenced by a lower RARI and improved early postoperative renal function compared to those of dopamine. These findings suggest a potential preferential role for norepinephrine in optimizing perioperative management and early graft functions in LDKT recipients. Given the retrospective nature of this study, further prospective studies are needed to confirm these observations. Additionally, the study limitations include the potential for unmeasured confounding factors and the inability to determine causality due to its observational design.

Purpose:This study aims to investigate the feasibility of Zenith Fenestrated AAA Endovascular Graft (Z-FEN, Cook Medical) from a single Korean institution database by evaluating the vascular anatomy of Korean abdominal aortic aneurysm (AAA) patients with hostile aortic neck.Methods:This is a retrospective study on patients with AAA who underwent endovascular aortic repair (EVAR) and open surgery repair between January 2012 and December 2021 (n = 211). The anatomic characteristics of the aortic neck were evaluated using 3-dimensional reconstructed computed tomographic scans. For the juxtarenal AAA patients (n = 39), feasibility of fenestrated stent graft was evaluated under the protocol of fenestrated EVAR. For those who were not suitable for the application of Z-FEN, the reasons for unsuitability were analyzed.Results:Among 211 AAA patients, 108 patients (51.2%) had complex aortic neck, and 39 (18.5%) had insufficient aortic neck length (<15 mm) for conventional EVAR. Of the 39 patients with juxtarenal AAAs, 13 (33.3%) were determined feasible for Z-FEN. Twenty-six patients (66.7%) were noncandidate for Z-FEN due to severe neck angulation, short aortic neck length, inadequate iliac artery anatomy, large aortic neck diameter, and severe calcification and thrombosis. Proximal aortic neck length of the non-feasible group was significantly shorter than that of the feasible group (P = 0.002).Conclusion:Z-FEN was applicable to 33.3% of the juxtarenal AAA patients. As recent studies confirm, the effectiveness and safety of fenestrated EVAR, Z-FEN can be an option for AAA patients with short aortic neck.

Hemodialysis vascular access parameters of intraoperative Color flow Doppler ultrasound remain controversial. This study aimed to evaluate the optimal cut‐off value and efficacy of intraoperative arteriovenous fistula parameters identified by Color flow Doppler ultrasound for arteriovenous fistula maturation success.

BACKGROUND:Peripherally inserted central catheter (PICC) has become a common procedure. Although ultrasound (US)-guidance has improved success rates, a small percentage of malposition is inevitable. The purpose of our study is to evaluate malposition rates of US-guided bedside PICC catheter insertion, and the clinical factors associated with malposition. METHODS:This is a retrospective cohort study evaluating 5981 patients who had undergone ultrasound-guided bedside PICC placement from January 2017 to December 2021 at a single tertiary center. Final tip location was confirmed on chest radiograph. RESULTS:Patients were categorized into optimal, suboptimal, and malposition groups according to final tip location. 4866 cases (81.7%) showed optimal tip position, 790 (13.3%) were suboptimal, and 299 (5.0%) were malpositioned. Logistic regression analysis identified six variables associated with tip malposition; height (odds ratio (OR) 1.044; 95% confidence interval (CI), 1.028-1.061; p < 0.001), body mass index (BMI) (OR 1.051; 95% CI, 1.017-1.087; p = 0.003), prior failure at accessing peripheral intravenous (IV) access (OR 1.718; 95% CI, 1.215-2.428; p = 0.002), side of the arm (OR 3.467; 95% CI, 2.457-4.891; p < 0.001), length of the catheter (OR 0.763; 95% CI, 0.734-0.794; p < 0.001), and number of previous central catheter insertions (OR 1.069; 95% CI, 1.004-1.140; p = 0.038). Malpositioned catheters were corrected by either bedside repositioning, bedside reinsertion, fluoroscopic reinsertion, switching to jugular catheters or catheter removal. No patient related factors were significantly associated with malposition or success of reposition. CONCLUSION:US-guidance can help reduce catheter malposition during bedside PICC insertion. Patients with risk factors such as multiple previous central vein insertions, failed peripheral line insertions, left arm insertion, or high BMI should undergo thorough sonographic evaluation of the arm vessels to prevent malposition.

Seung Chul Lee, M.D., Tae Sik Kim, M.D., Sangchul Yun, M.D., Wooshik Kim, M.D., Heangjin Ohe, M.D., Sang Seob Yun, M.D. and Sung Ho Lee, M.D.. Ann Phlebology 2023;21:70-3. https://doi.org/10.37923/phle.2023.21.2.70

Wooshik Kim, M.D., Tae Sik Kim, M.D., Sangchul Yun, M.D., Heangjin Ohe, M.D., Seung Chul Lee, M.D., Sung Ho Lee, M.D. and Sang Seob Yun, M.D.. Ann Phlebology 2023;21:60-2. https://doi.org/10.37923/phle.2023.21.2.60

OBJECTIVES:Current guidelines recommend initial postoperative follow-up with computed tomography angiography (CTA) after endovascular aneurysm repair (EVAR). However, CTA has risks associated with ionizing radiations and nephrotoxic contrast agents. We investigated possibilities to replace the initial postoperative CTA with contrast enhanced duplex ultrasound (CE-DUS) in selected patients.METHODS:Out of the 273 consecutive patients who underwent EVAR, 173 were excluded and the 100 patients who underwent CTA and CE-DUS imaging concurrently (≤1 month interval between CTA and CE-DUS imaging) within 60 days after EVAR were analyzed. Patients who underwent EVAR outside the manufacturer's instructions for use or who had endoleaks discovered on intraoperative angiography were classified as the high-risk group, otherwise, they were classified as the low-risk group. Measurements of diagnostic values of CE-DUS ​​related to the detection of complications were calculated using CTA as the gold standard. McNemar's test was performed to compare these values and Pearson correlation coefficient was derived to compare CE-DUS measurements of sac diameters with CTA.RESULTS:In the low-risk group, no difference was observed between CE-DUS and CTA in the detection of EVAR-related complications (sensitivity = 0.95, specificity = 0.93). In the high-risk group, CE-DUS was not as accurate as CTA for the detection of overall EVAR-related complications (sensitivity = 0.57, specificity = 0.86, p = 0.04) and for the detection of complications other than endoleaks (p = 0.02). Regarding sac diameter measurement, there was good agreement between CE-DUS and CTA (r = 0.92, p < 0.001).CONCLUSIONS:First postoperative CE-DUS was reliable for the evaluation of EVAR-related complications compared to CTA in selected patients. Individualized EVAR follow-up strategy using CE-DUS based on the initial risk of EVAR-related complications should be considered.

Vascular access (VA), a renal failure therapy, is often performed using an arteriovenous (AV) graft for patients with veins and arteries that cannot be connected with autologous blood vessels. However, VA using AV grafts can change the blood flow and lead to intimal hyperplasia (IH), causing the damage on blood vessel and failure of VA. In our study, we investigated the effect of the anastomosis angle on blood vessel damage under various IH formation conditions. We simulated the blood flow near the anastomosis between vein and AV graft and quantitatively evaluated the blood vessel damage using hemodynamic factors, such as wall shear stress (WSS). Our results show that smaller anastomosis angle reduces damage to blood vessels and prevents IH formation and growth regardless of IH progression, shape, and position. These results can contribute to optimization of the anastomosis angle during VA surgery to improve a patient’s prognosis.