J K Hwang

Catholic University of Korea, Sŏul, Seoul, South Korea

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Publications (10)18.01 Total impact

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    ABSTRACT: The purpose of this study was to determine the natural history of arteriovenous (AV) access after successful kidney transplantation (KT) and to identify the risk factors of spontaneous access closure in kidney transplant recipients. We performed a retrospective review of 115 patients who underwent KT with functioning access from June 2010 to July 2012. AV access patency was checked and recorded daily during the hospital stay and at every visit to the outpatient clinic. Patients were divided into 2 groups according to the patency of access, and risk factors of access thrombosis were assessed. Access patency was followed up until patency was lost or the study was closed. At the end of follow-up, 18 (15.7%) AV accesses had spontaneously closed. Mean time to closure was 119 ± 163 days, and 12 of 18 were closed within 90 days after KT. AV access spontaneously closed in 8.5% of male patients, compared with 27.3% of female patients (P = .007), 12.2% of cases with native access compared with 35.3% of cases with artificial access (P = .016), and 11.3% of cases with wrist access compared with 25.7% of cases with elbow access (P = .049). Spontaneously closed AV accesses tended to have a lower mean access flow compared with functioning accesses (P = .019). On multivariate analysis, female sex and AV access flow volume affected spontaneous AV access closure (odds ratio 4.749, 95% confidence interval 1.919-35.383, P = .008; odds ratio 0.998, 95% confidence interval 0.996-0.999, P = .010, respectively). Our results suggest that AV access thrombosis occurs more frequently during the early postoperative period, particularly in female patients or patients with low flow access, whereas it is a rare event in male patients or patients with high access flow, especially in the late postoperative period.
    Transplantation Proceedings 03/2014; 46(2):602-6. · 0.95 Impact Factor
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    ABSTRACT: Our objective was to compare the clinical outcomes of adult kidney transplants from expanded criteria deceased donors (ECD) with those from concurrent standard criteria deceased donors (SCD). Between January 2000 and December 2011, we transplanted 195 deceased donor renal transplants into adult recipients, including 31 grafts (15.9%) from ECDs and 164 grafts (84.1%) from SCDs. ECDs were classified using the United Network for Organ Sharing (UNOS) definitions. Donor and recipient risk factors were analyzed separately and their correlation with recipient graft function and survival was evaluated (minimum 6-month follow-up). ECDs were older (56.8 ± 6.3 years), showed an increased incidence of hypertension, diabetes, and cerebrovascular brain death, and had a higher preretrieval serum creatinine level than SCDs. ECD kidney recipients had a shorter waiting time (P = .019) but other baseline characteristics (age, gender, body mass index [BMI], cause of end-stage renal disease, type of renal replacement therapy, incidence of diabetes and hypertension, number of HLA antigen mismatches, positivity for panel-reactive antigen, and cold ischemic time) were not significantly different from those of SCD kidney recipients. Mean glomerular filtration rate (GFR) at 1 month, 6 months, 1 year, and 3 years after transplantation was significantly lower in recipients of ECD transplants than recipients of SCD transplants, but the GFR level at 5 and 10 years was not significantly different between ECD and SCD recipient groups (P = .134 and .702, respectively). Incidence of acute rejection episodes and surgical complications did not differ significantly between the 2 recipient groups, but the incidence of delayed graft function (DGF) and infectious complications was higher in ECD kidney recipients than SCD kidney recipients (P = .007 and P = .008, respectively). Actual patient and graft survival rates were similar between the 2 recipient groups with a mean follow-up of 43 months. There were no significant differences in graft survival (P = .111) or patient survival (P = .562) between the 2 groups. Although intermediate-term renal function followed longitudinally was better in SCD kidney recipients, graft and patient survival of ECD kidney recipients were comparable with those of SCD kidney recipients. In conclusion, use of renal grafts from ECDs is a feasible approach to address the critical organ shortage.
    Transplantation Proceedings 01/2014; 46(2):431–436. · 0.95 Impact Factor
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    ABSTRACT: Heat shock proteins (HSP) play an important role in protecting cells against stress. Using a rat model, we tested the hypothesis that pretreatment with glutamine (Gln) and ischemia preconditioning (IPC) increase the expression of HSP resulting in attenuation of renal ischemia/reperfusion (I/R) injury. Sprague-Dawley rats were randomized into 4 groups [group I, Gln injection (+), IPC (+); group II, Gln injection (+), IPC (-); group III, saline injection (+), IPC (+); group IV, saline injection (+), IPC (-)]. Renal HSP70 expression was determined by Western blotting and kidney function was assessed by blood urea nitrogen and serum creatinine. Renal cross-sections were microscopically examined for tubular necrosis, exfoliation of tubular epithelial cells, cast formation, and monocyte infiltration. Gln pretreatment increased intrarenal HSP expression (P = .031). In group I, tubulointerstitial abnormalities were clearly slighter compared with the other groups (P < .001). Our experiments suggest that (1) a single dose of Gln could induce HSP expression and (2) IPC could relieve renal I/R injury. In addition, IPC combined with Gln pretreatment had a synergic protective effect against renal I/R injury.
    Transplantation Proceedings 11/2013; 45(9):3203-8. · 0.95 Impact Factor
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    ABSTRACT: Our objective was to evaluate the usefulness of three-dimensional (3-D) contrast-enhanced (CE) magnetic resonance angiography (MRA) to assess renal parenchyma, arterial inflow stenosis, and peritransplant fluid collections in the early period after kidney transplantation (KT). Between January 2010 and April 2011, we examined a consecutive series of 144 renal transplants using 3-D CE MRA at 14 days after KT. MRA showed parenchyma infarctions (n = 17, 11.8%), arterial inflow stenoses (n = 23, 16%), lymphoceles (n = 14, 9.7%), and hematomas (n = 6, 4.2%). The degree of renal transplant artery inflow stenosis was graded qualitatively based on diameter criterion; <50% = mild, 50% to 70% = moderate, and >70% = severe in 10 (6.9%), 5 (3.5%), and 8 (5.6%) subjects, respectively. The study recipients were divided into 3 groups according to the degree of renal artery inflow stenosis (group I: normal; group II: mild and moderate, <70%; group III: severe, >70%). Among group III patients who underwent digital subtraction angiography, 5 had percutaneous transluminal angioplasty or stenting performed after 1 month. Their mean resume creatinine levels at 1, 6, and 12 months after transplantation were not significantly different from those in the other groups (P = .391, .447, .110). The prevalence of graft loss (n = 2) was high in group III (P = .012), although the frequency of acute rejection episodes was not different among the groups (P = .890). The incidences of renal parenchyma infarction, peritransplant fluid collection and arterial inflow stenosis were unexpectedly high in the early period after KT. Thus, 3-D CE MRA provided a rapid global assessment of the renal parenchyma, transplant arterial system, and peritransplant fluid collection that can be helpful to detect or exclude many causes of renal transplant dysfunction.
    Transplantation Proceedings 10/2013; 45(8):2925-30. · 0.95 Impact Factor
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    ABSTRACT: This study evaluated the effect of the donor kidney to recipient body weight (Kw/Rw) ratio on long-term graft function and survival. We investigated retrospectively whether there was any association between Kw/Rw ratio and long-term graft survival and function after a follow-up of >10 years. We studied a consecutive series of 123 adult-to-adult living kidney transplants. According to the Kw/Rw ratio, patients were divided into 3 groups: "low" (Kw/Rw <2.85; n = 29), "medium" (2.85 ≤ Kw/Rw < 4.04; n = 63), and "high" (≥4.04; n = 31). Among the 3 groups, the mean serum creatinine levels at 1 and 6 months as well as 1 year after transplantation were significantly lower among patients with a high Kw/Rw ratio than in those with a medium or low ratio, but serum creatinine levels at 3 and 5 years did not differ significantly (P = .394 and 0.620, respectively). Graft survival rates at 5 and 10 years after transplantation were significantly lower in the "low" group. We observed a significant association between Kw/Rw ratio and graft survival (P = .018). The Kw/Rw ratio is an important factor for long-term graft survival and early graft function. However, it did not significantly affect subsequent renal function.
    Transplantation Proceedings 01/2012; 44(1):276-80. · 0.95 Impact Factor
  • J K Hwang, H J Chun, I S Moon, J I Kim
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    ABSTRACT: Ipsilateral acute iliofemoral deep vein thrombosis (DVT) immediately after kidney transplantation is rare but highly morbid, resulting in allograft failure, rupture, or even death. Treatment modalities for iliofemoral DVT occurring just after transplantation are limited due to bleeding risk and impaired renal function. A 55-year-old woman with end-stage renal disease from hypertension underwent a living nonrelated donor procedure using a kidney from her husband. On postoperative day 1, the patient presented edema and pain in the right lower extremity associated with local heat and redness. The symptoms became aggravated with time. Duplex ultrasonography (US) revealed a DVT involving from the right femoral vein to the common iliac vein and an increased resistive index of 0.96 to 0.97. A venogram using carbon dioxide as the contrast medium showed also same findings as the duplex US. After inferior vena cava filter insertion, percutaneous transluminal thromboaspiration (PTA) was performed with complete removal of the thrombus. Early PTA with carbon dioxide as intravenous contrast material seemed to be an effective and safe procedure to treat this complication.
    Transplantation Proceedings 01/2011; 43(6):2415-7. · 0.95 Impact Factor
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    ABSTRACT: Kidneys with multiple renal arteries are increasingly procured for transplantation. To compare the outcomes of kidney transplantation using allografts with multiple arteries, we studied long-term graft function and survival according to their number of arterial anastomoses during an 18-year period from July 1, 1990, through December 31, 2008, in which only the recipient's external iliac artery or internal iliac artery was used for anastomosis (n = 1186). The recipients were divided into four groups: group I, single renal artery with single anastomosis (n = 890, 75.0%); group Il, multiple renal arteries, single anastomosis (n = 26, 2.2%); group Ill, multiple renal arteries, multiple anastomoses (n = 236, 19.9%); and group IV, polar artery ligation (n = 34, 2.9%). We compared the following variables patient and graft survivals; mean creatinine levels at 1 and 6 months, as well as 1-, 3-, and 5-years posttransplant; the number of acute rejection episodes, and the rates of vascular and urologic complications. The creatinine values and incidences of acute rejection episodes did not differ significantly (P = 0.399 and P = 0.990, respectively). There were no significant differences among the four groups in graft survival (P = 0.951), patient survival (P = 0.751), incidence of vascular (P = 0.999) or urologic complications (P = 0.371). The four groups were subdivided according to the recipient arterial anastomosis to the main graft renal artery. The subdivided groups showed no significant differences in graft or patient survival, or complications rates. The results indicated that multiplicity of renal arteries in kidney transplantation did not adversely affect allograft or patient survival compared with single renal artery transplantation. Moreover, the type of the arterial anastomosis (main renal artery end-to-end anastomosed to internal iliac artery or end-to-side anastomosed to external iliac artery appeared to not affect graft or patient survival or the incidence of vascular or urologic complications.
    Transplantation Proceedings 12/2010; 42(10):4053-7. · 0.95 Impact Factor
  • Transplantation 01/2010; 90. · 3.78 Impact Factor
  • Transplantation 01/2010; 90. · 3.78 Impact Factor
  • Transplantation 01/2010; 90. · 3.78 Impact Factor