J.K. Hwang

The Long-Term Outcomes of Transplantation of Kidneys With Multiple Renal Arteries

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 recipients 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.

Comparative Analysis of ABO-Incompatible Living Donor Kidney Transplantation With ABO-Compatible Grafts: A Single-Center Experience in Korea

INTRODUCTIONnSerious organ shortages have necessitated the use of ABO-incompatible (ABOi) kidneys transplantation, which has been increasingly preformed in Korea. However there are few detailed comparative data regarding patient and graft survival, graft function, and complications in Korean patients receiving ABO-compatible (ABOc) and ABOi kidney transplants (KT).nnnMETHODSnThis retrospective study compared 35 consecutive ABOi living donor KTs with 138 ABOc living donor KTs using same immunosuppressive regimens. We examined preoperative demographic factors, immunologic risk factors, patient and graft survivals, postoperative renal function, acute rejection episodes, infections, medical and surgical complications, duration of hospital stay as well as cause for readmission, and their rates.nnnRESULTSnPatient survival, graft survival, and graft function over the 2 years after transplantation were similar between the 2 groups. There were no significant differences in terms of complications with exception of bleeding and BK virus infection. Acute antibody-mediated rejection episodes, bleeding complications, BK virus infections, and preoperative hospital stay were significantly greater in the ABOi group (Pxa0= .001, Pxa0= .002, Pxa0= .005, and Pxa0< .001 respectively).nnnCONCLUSIONSnWe concluded that, despite some disadvantages, ABOi KT is a viable, safe option for patients whose only available donor is blood group incompatible.

Does Donor Kidney to Recipient Body Weight Ratio Influence Long-Term Outcomes of Living-Donor Kidney Transplantation?

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.

The Early Protective Effect of Glutamine Pretreatment and Ischemia Preconditioning in Renal Ischemia–Reperfusion Injury of Rat

BACKGROUNDnHeat shock proteins (HSP) play an important role in protecting cells against stress.nnnMETHODSnUsing 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.nnnRESULTSnGln pretreatment increased intrarenal HSP expression (Pxa0= .031). In group I, tubulointerstitial abnormalities were clearly slighter compared with the other groups (Pxa0< .001).nnnCONCLUSIONnOur 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.

Contrast-Enhanced Magnetic Resonance Angiography in the Early Period After Kidney Transplantation

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 (nxa0= 17, 11.8%), arterial inflow stenoses (nxa0= 23, 16%), lymphoceles (nxa0= 14, 9.7%), and hematomas (nxa0= 6, 4.2%). The degree of renal transplant artery inflow stenosis was graded qualitatively based on diameter criterion;xa0<50%xa0= mild, 50% to 70%xa0= moderate, and >70%xa0= 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,xa0<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 (Pxa0= .391, .447, .110). The prevalence of graft loss (nxa0= 2) was high in group III (Pxa0= .012), although the frequency of acute rejection episodes was not different among the groups (Pxa0= .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.

Impact of Pretransplant Panel-Reactive Antibody Level on Renal Graft Survival in Patients With a Negative Crossmatch and No Donor-Specific Antibody.

BACKGROUNDnPatients with high panel-reactive antibody (PRA) levels before transplantation tend to remain on the waiting list longer when considering cadaveric donor transplantation and have worse outcomes than those with lower PRA levels. This study investigated the impact of the pretransplantation PRA level on rejection and graft survival after kidney transplantation in patients with a negative crossmatch (CXM(-)) and no donor-specific antibody (DSA(-)).nnnMETHODSnWe retrospectively analyzed 513 recipients of kidney allograft treated from January 2009 to April 2013. Those who tested positive on crossmatching, had donor-specific antibodies, were ABO incompatible, or had no PRA level data were excluded (nxa0= 130). The remaining patients were stratified into 3 groups according to their PRA levels: group I, PRAxa0= 0 (314 [80.1%]); group II, PRAxa0≤50% (27 [7.2%]); and group III, PRA >50% (27 [7.2%]). Graft failure was defined as a return to dialysis, transplant nephrectomy, or death with a functioning kidney.nnnRESULTSnThe mean patient follow-up was 30.4 ± 4.6 months. The rejection rate was 20.1% (group I, 18.5% [nxa0= 58] vs group II, 23.8% [nxa0= 10] vs group III, 33.3% [nxa0= 9] [Pxa0= .053]). The graft failure rate was 21.7% (group I, 6.4% [nxa0= 20] vs group II. 7.1% [nxa0= 3] vs group III, 7.4% [nxa0= 7] [Pxa0= .792]), and the 3-year graft survival rates were 96.3, 92.4, and 92.5%, respectively (Pxa0= .851).nnnCONCLUSIONSnThe pretransplant PRA level was not significantly associated with graft survival in patients with CXM(-) and DSA(-). However, the rejection rate tended toward significance as the PRA level increased (Pxa0= .053).

Effect of Donor-Recipient Age Match in Expanded Criteria Deceased Donor Kidney Transplantation

PURPOSEnOur objective was to investigate the effects of age on patient and graft survival in expanded criteria donor (ECD) renal transplantation.nnnMETHODSnBetween February 2000 and December 2015, we analyzed 405 deceased donor renal transplants, including 128 grafts (31.9%) from ECDs. Based on recipient age and ECD criteria classification, the recipients were divided into four groups: Group I, non-ECD to recipient agexa0<50 years; Group II, non-ECD to recipient agexa0≥50 years; Group III, ECD to recipient agexa0<50 years; and Group IV, ECD to recipient agexa0≥50 years.nnnRESULTSnAmong the four groups, there were significant differences in baseline characteristics (age, body mass index [BMI], cause of end-stage renal disease [ESRD], number of kidney transplantations, and use of induction agent). The mean modification of diet in renal disease (MDRD) glomerular filtration rate (GFR) level at 1 month, 6 months, 1xa0year, 3 years, and 5 years after transplantation was significantly lower in patients with ECDs but MDRD GFR level at 7, 9, and 10 years did not differ significantly (Pxa0= .183, .041, and .388, respectively). There were no significant differences in graft survival (Pxa0=xa0.400) and patient survival (Pxa0= .147).nnnCONCLUSIONnOur result shows that, regardless of recipient age, kidney transplants donated by deceased ECDs have similar graft and patient survival.

Image similarity evaluation of the bulk-density-assigned synthetic CT derived from MRI of intracranial regions for radiation treatment

Objective Various methods for radiation-dose calculation have been investigated over previous decades, focusing on the use of magnetic resonance imaging (MRI) only. The bulk-density-assignment method based on manual segmentation has exhibited promising results compared to dose-calculation with computed tomography (CT). However, this method cannot be easily implemented in clinical practice due to its time-consuming nature. Therefore, we investigated an automatic anatomy segmentation method with the intention of providing the proper methodology to evaluate synthetic CT images for a radiation-dose calculation based on MR images. Methods CT images of 20 brain cancer patients were selected, and their MR images including T1-weighted, T2-weighted, and PETRA were retrospectively collected. Eight anatomies of the patients, such as the body, air, eyeball, lens, cavity, ventricle, brainstem, and bone, were segmented for bulk-density-assigned CT image (BCT) generation. In addition, water-equivalent CT images (WCT) with only two anatomies—body and air—were generated for a comparison with BCT. Histogram comparison and gamma analysis were performed by comparison with the original CT images, after the evaluation of automatic segmentation performance with the dice similarity coefficient (DSC), false negative dice (FND) coefficient, and false positive dice (FPD) coefficient. Results The highest DSC value was 99.34 for air segmentation, and the lowest DSC value was 73.50 for bone segmentation. For lens segmentation, relatively high FND and FPD values were measured. The cavity and bone were measured as over-segmented anatomies having higher FPD values than FND. The measured histogram comparison results of BCT were better than those of WCT in all cases. In gamma analysis, the averaged improvement of BCT compared to WCT was measured. All the measured results of BCT were better than those of WCT. Therefore, the results of this study show that the introduced methods, such as histogram comparison and gamma analysis, are valid for the evaluation of the synthetic CT generation from MR images. Conclusions The image similarity results showed that BCT has superior results compared to WCT for all measurements performed in this study. Consequently, more accurate radiation treatment for the intracranial regions can be expected when the proper image similarity evaluation introduced in this study is performed.

Characteristics of Femoral Motor Neuropathies Induced After Kidney Transplantation: A Case Series

BACKGROUNDnFemoral motor neuropathy (FMN) induced after kidney transplantation (KT) can injure the patient and graft, and it sometimes can leave sequelae on gait. Nevertheless, the cause of FMN has not been determined. We assessed 5 cases of FMN in an attempt to determine the traits induced after KT.nnnMETHODSnPatient data about general characteristics, immunologic characteristics, operative findings, post-operative status, and FMN characteristics were assessed. A Bookwalter self-retaining retractor was used and quadruple immunosuppression was implemented in all cases.nnnRESULTSnFive patients had FMN. Four of the 5 patients were women. The mean body mass index (BMI) was 20.38 ± 1.99xa0kg/m(2) prior to KT and 19.08 ± 1.98xa0kg/m(2) after KT. The mean graft-recipient weight ratio was 3.46 ± 0.99xa0g/kg. There was no case of psoas muscle abscess or hematoma. Motor function recovery was obtained 3 to 313 days after rehabilitation. Immediate graft function was favorable in all patients with no rejection or significant complications.nnnCONCLUSIONSnFMN after KT may occur in patients with a lower BMI and higher graft-recipient weight ratio. This study was based on only 5 patients, and therefore further studies with a larger population size are necessary.

The natural history of arteriovenous access and risk factors associated with access thrombosis after successful kidney transplantation.

INTRODUCTIONnThe 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.nnnMETHODSnWe 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.nnnRESULTSnAt 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).nnnCONCLUSIONSnOur 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.