Arteriovenous fistula in a renal allograft with gross hematuria and subsequent acute kidney injury due to urinary tract obstruction: a case report.

BACKGROUND: Arteriovenous fistula (AVF) due to renal allograft biopsy is mechanical trauma resulting from the penetration of small arteries and veins by a core needle. Most AVFs are reported to resolve asymptomatically and spontaneously. This report presents a patient with acute kidney injury (AKI) due to urinary tract obstruction caused by a bleeding AVF in a renal allograft. CASE PRESENTATION: A 22-year-old Japanese woman who underwent living-donor kidney transplantation (KT) at 3 years due to end-stage renal disease caused by focal segmental glomerulosclerosis (FSGS) presented with a renal transplant AVF (gourd-shaped; 42 × 19 × 20 mm). The AVF was unexpectedly discovered by ultrasound before a surveillance biopsy at 10 years after KT. The patient had a history of recurrent FSGS, had undergone several renal allograft biopsies after KT, and did not experience symptoms or growth of the AVF for years. Nineteen years after KT, the patient developed AKI with sudden, asymptomatic, gross hematuria and anuria. Plain computed tomography revealed a hematoma in the pelvis of the renal allograft and bladder tamponade. The AVF was successfully treated by coil embolization. Hemodialysis was performed for AKI, and graft function was gradually recovered. CONCLUSIONS: Unexpected bleeding from a renal transplant AVF may lead to transplant dysfunction. Angiographic embolization against the ruptured renal transplant AVF may prevent rebleeding and rescue the renal allograft.

Vesicoureteral Reflux Causes Interstitial Inflammation in Pediatric Kidney Allograft: A Clinicopathological Analysis of 1-Year Protocol Biopsies.

INTRODUCTION: At present, there is limited evidence of the histological impact of vesicoureteral reflux (VUR) on pediatric kidney allografts. In this study, we aimed to investigate the relationship between VUR diagnosed by voiding cystourethrography (VCUG) and 1-year protocol biopsy results. METHODS: One hundred thirty-eight pediatric kidney transplantations were performed in Toho University Omori Medical Center between 2009 and 2019. We included 87 pediatric transplant recipients who were evaluated for VUR by VCUG prior to or at the time of the 1-year protocol biopsy and underwent a 1-year protocol biopsy after transplantation. We evaluated the clinicopathological findings of the VUR and non-VUR groups, and histological scores were evaluated using the Banff score. Tamm-Horsfall protein (THP) within the interstitium was identified by light microscopy. RESULTS: Of the 87 transplant recipients, 18 cases (20.7%) were diagnosed with VUR by VCUG. The clinical background and findings were not significantly different between the VUR and non-VUR groups. The pathological findings revealed a significantly higher Banff total interstitial inflammation (ti) score in the VUR group than in the non-VUR group. Multivariate analysis indicated a significant relationship between the Banff ti score and THP within the interstitium, and VUR. The 3-year protocol biopsy results (n = 68) revealed a significantly higher Banff interstitial fibrosis (ci) score in the VUR group than in the non-VUR group. CONCLUSION: VUR caused interstitial fibrosis in the 1-year pediatric protocol biopsies, and interstitial inflammation at the 1-year protocol biopsy may affect interstitial fibrosis at the 3-year protocol biopsy.

Prognostic value of the 7-year protocol biopsy of adult kidney allografts: impact of mesangiosclerosis and proteinuria.

AIM: The aim of the present study was to clarify the relationship between the Banff score of the 7-year protocol biopsy and the allograft outcome. METHODS: One-hundred-and-eighty-four patients received kidney transplantation from 2002 to 2008. We excluded patients aged <20 years at transplantation (n = 24), those who did not undergo a 7-year protocol biopsy (n = 66), and those who underwent for-cause biopsy (n = 5). Consequently, 89 patients who underwent a 7-year protocol biopsy were enrolled. We analyzed the relationship between the clinicopathological findings 7 years after transplantation and the estimated glomerular filtration rate (eGFR) change per year and allograft survival. Histological evaluation was performed using the Banff 2015 classification. RESULTS: Among the clinicopathological findings, each Banff mesangial matrix increase (mm) score ≥1 and proteinuria ≥1+ was independently associated with the eGFR decline per year during a median follow-up of 73 months. Furthermore, in the model of the clinicopathological findings including the presence of mm with proteinuria, mm ≥1 alone and mm ≥1 with proteinuria were each independently associated with the eGFR decline. The graft survival was significantly worse for those with mm ≥1 with proteinuria than those with mm ≥1 without proteinuria. CONCLUSION: Among the 7-year protocol biopsy findings, the presence of mm alone and mm with proteinuria were each significant predictors of eGFR decline. The presence of both proteinuria and mm had a negative impact on graft survival. These results underscore the significance of the Banff mm score and proteinuria at the time of the 7-year protocol biopsy to predict the allograft outcome.

Subclinical C1q Nephropathy Combined with Possible Donor-Derived IgA Deposition in a 1-Year Kidney Allograft Biopsy: A Case Report.

Few previous studies have reported immune-complex nephropathy that has not been classified as a specific phenotype in kidney allografts. We report a case of a de novo subclinical "full-house" pattern of deposition in a pediatric transplantation recipient with possible donor-derived IgA deposition. A five-year-old boy underwent living kidney transplantation due to congenital kidney and urinary tract anomalies. A one-hour implantation biopsy revealed IgA deposition. A four-month protocol biopsy finding showed less intense IgA deposition, in contrast with the one-hour biopsy, and trace para-mesangial deposits. A one-year protocol biopsy demonstrated a full-house deposition pattern and massive electron-dense deposits with minor glomerular changes. At the time of the one-year biopsy, kidney function was stable, with no urinalysis abnormalities. No evidence of systemic lupus erythematosus was observed in clinical and serologic examinations. Mesangial IgG, IgM, C3, and C1q deposition was codominant, and IgA deposition was weaker. We diagnosed this case as C1q nephropathy combined with remaining donor-derived IgA deposition. Few studies have reported C1q nephropathy in kidney allograft; further accumulation of cases is required. To distinguish between donor-derived and de novo glomerular lesions, it is important to assess the serial histologic findings of immunofluorescence and electron microscopy. Here, we report a rare case of subclinical C1q nephropathy with possible donor-derived IgA nephropathy.

Changes in graft function after living donor kidney transplantation in children.

BACKGROUND: This study aimed to evaluate the change in graft function in two groups stratified by the estimated glomerular filtration rate (eGFR) at 1 month after transplantation (eGFR-1 M) in pediatric living donor kidney transplant recipients. METHODS: Forty-three pediatric recipients were classified as those with an eGFR-1 M ≥ 90 mL/min/1.73 m2 (n = 19; high eGFR group) or those with an eGFR-1 M of 60-89 mL/min/1.73 m2 (n = 24; middle eGFR group). In the two groups, changes in the eGFR were retrospectively evaluated for 5 years after kidney transplantation. RESULTS: The mean recipient age at transplantation in the high/middle eGFR group was 6.1 ± 3.4/7.8 ± 4.0 years (P = 0.14). The mean eGFR-1, -12, and -60 M (mL/min/1.73 m2) in the high/middle eGFR group were 106.8 ± 2.99/78.5 ± 1.52 (P < 0.001), 79.3 ± 3.22/62.7 ± 2.38 (P < 0.001), and 73.1 ± 4.16/59.2 ± 2.79 (P = 0.006), respectively. The change in the mean eGFR remained mostly parallel in the two groups. In both groups, the eGFR significantly decreased only between 1 and 12 months after transplantation (P < 0.0001). Approximately 70% of the patients had an eGFR-60 M ≥ 60 mL/min/1.73 m2. CONCLUSIONS: The high and middle eGFR groups showed a rapid decline in the eGFR by 1 year after transplantation, but the change thereafter was gradual. In pediatric living donor kidney transplant recipients, the eGFR was relatively well maintained up to 5 years after transplantation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Outcome of ABO-incompatible kidney transplantation using a modified desensitization protocol without plasmapheresis.

OBJECTIVES: Several controversies regarding desensitization strategies for successful ABO-incompatible (ABOi) kidney transplantation still exist. This study aimed to investigate whether pretransplant anti-A/B antibody removal is mandatory in an ABOi kidney transplant recipient with low baseline isoagglutinin titers. METHODS: We adopted a modified desensitization protocol with two doses of rituximab (RTX, 100 mg/body) without pretransplant antibody removal for ABOi kidney transplant recipients with a titer of ≤1:64 (group A; n = 35) and investigated the feasibility of this protocol by comparing it with the clinical outcomes of patients undergoing standard pretransplant plasmapheresis (group B; n = 21). RESULTS: There was no significant difference in the rate of antibody-mediated rejection within the first month after transplantation between the two groups (11.4% in group A vs. 2% in group B, p = 0.6019). Moreover, no differences were observed in the short- and long-term graft outcomes between the groups. However, two major critical acute antibody-mediated events occurred in group A; one patient lost the graft due to hyperacute rejection, and the other patient developed thrombotic microangiopathy after surgery. Risk factors predicting these perioperative complications were not identified. CONCLUSIONS: We conclude that not only B-cell depletion using RTX but also pretransplant antibody removal is still recommended even for patients with low isoagglutinin titers. In addition, a new diagnostic tool is needed for accurate risk stratification.

Long-term social outcome after pediatric kidney transplantation: a single-center experience.

BACKGROUND: Patient and graft survival rates after pediatric kidney transplantation have improved recently. Therefore, the quality of life or social outcome after kidney transplantation has become important for patients and their families. METHODS: Patients who underwent kidney transplantation at < 18 years old and were observed for > 10 years were included in this study. The median age at first kidney transplantation was 9.2 (interquartile range [IQR] = 5.6-13.0) years; there were 56 males and 50 females. The median age at last follow-up was 29.9 (IQR = 22.2-36.0) years. We evaluated the patients' renal function, growth, professional status, and marital status at the last follow-up. RESULTS: The percentage of functioning grafts at the last follow-up was 81.1%; 73 patients (68.9%) had a first graft. The mean estimated GFR was 51.0 ± 20.5 mL/min/1.73 m2. Twenty patients received dialysis for graft failure. The mean final heights of the males and females were 158.1 ± 9.2 cm (- 2.2 standard deviations) and 149.1 ± 6.4 cm (- 1.7 standard deviations), respectively. Excluding 23 students, 63 patients (75.9%) were employed. Office worker was the most common profession. Twelve patients (14.5%) were unemployed. Of patients > 20 years old, 14 (16.7%), three males and 11 females, were married. Five females had one child each. CONCLUSIONS: The graft survival rate was favorable. The final height was short, particularly in male. The rate of employment was relatively high. The rate of marriage and having children were still low. Improving the social outcome is an important problem after pediatric kidney transplantation.

Incidence of malignancy after pediatric kidney transplantation: a single-center experience over the past three decades in Japan.

BACKGROUND: Malignancy after kidney transplantation (KT) is one of the most serious post-transplant complications. This study aimed to investigate the incidence, type, and outcomes of malignancy after pediatric KT. METHODS: We performed a retrospective cohort study on pediatric kidney transplant recipients aged 18 years or younger who received their first transplant between 1975 and 2009. RESULTS: Among the 375 children who underwent KT, 212 were male (56.5%) and 163 were female (43.5%) (median age at KT, 9.6 years [interquartile range {IQR}] 5.8-12.9 years). The incidence of malignancy was 5.6% (n = 21). The cumulative incidences of cancer were 0.8%, 2.5%, 2.8%, 4.2%, 5.5%, and 15.6% at 1, 5, 10, 15, 20, and 30 years post-transplantation, respectively. Of 375 patients, 12 (3.2%) had solid cancer and nine (2.4%) had lymphoproliferative malignancy. The median age at the first malignancy was 21.3 years (IQR 11.5-33.3 years). The median times from transplant to diagnosis were 22.3 years (IQR 12.3-26.6 years) for solid cancer and 2.2 years (IQR 0.6-2.8) for lymphoproliferative malignancies. During follow-up, five recipients died due to malignancy. The causes of death were hepatocellular carcinoma in one patient, squamous cell carcinoma in the transplanted kidney in one patient, malignant schwannoma in one patient, and Epstein-Barr virus-related lymphoma in two patients. The mortality rate was 0.79 per 1000 person-years (95% confidence interval 0.38, 1.85). CONCLUSIONS: Early diagnosis and treatment of malignancies in transplant recipients is an important challenge. Therefore, enhanced surveillance and continued vigilance for malignancy following KT are necessary.

Comparison of live donor predonation and post-transplant kidney volumes and glomerular size in pediatric patients weighing less than 15 kg - a retrospective study.

Renal transplantation of adult-size kidneys presents a size mismatch in small children. This study presents a comparison of live donor predonation and recipient post-transplant kidney volumes (k-vol) and glomerular size at 1 year after transplantation. We analyzed 47 pediatric renal transplant recipients weighing <15 kg between 2009 and 2017. The k-vol before and 1 year after transplantation and glomerular size at implant and 1 year post-transplant were evaluated. We estimated the relationships between these changes and graft function, and the factors associated with k-vol. Pretransplant k-vol was 158.1 ± 25.1 ml, and the k-vol at 1 year post-transplant was significantly reduced by -17.2% to 132.3 ± 27.3 ml (P < 0.001). Implant glomerular size showed the diameter was 165.3 ± 15.1 µm and the area 20 737.1 ± 3230.6 µm2 . One-year post-transplant, the glomerular diameter was 150.6 ± 11.4 µm and the area 17 428.3 ± 2577.9 µm2 , significantly reduced compared with implantation values (both P < 0.001). The change in k-vol was affected by pretransplant abdominal cavity (ml/200 ml cavity volume, partial regression coefficient = 0.029, SE = 0.009, P = 0.004) and recipient's weight gain (ml/5% of weight gain, partial regression coefficient = 0.020, SE = 0.006, P = 0.002). In small pediatric transplants, an adult-size kidney is acceptable with reduction in k-vol. Moreover, the post-transplant k-vol might be regulated by pretransplant physique and post-transplant somatic growth.

ABO-incompatible pediatric kidney transplantation without antibody removal.

BACKGROUND: Because of the severe shortage of suitable deceased donors, ABO-incompatible living donor kidney transplantation (ABOi LDKT) is performed even in pediatric recipients in Japan. We performed pediatric ABOi LDKT using rituximab without anti-A/B antibody removal. METHODS: Thirteen pediatric recipients (mean age 7.4, range 3.4-15.7, four females) whose baseline anti-A/B IgG titers were ≤ × 64 underwent ABOi LDKT without antibody removal and splenectomy between July 2013 and April 2017 at Toho University. Mycophenolate mofetil (MMF) was initiated on day - 10. Rituximab (100 mg) was administered twice. Basiliximab and triple maintenance immunosuppression (calcineurin inhibitor, MMF, and steroids) were administered. Protocol biopsy was performed at 3 months and 1 year after transplantation. We retrospectively compared the clinical outcomes between these recipients and 37 children (mean age 9.0, range 2.6-18.9, 15 female) who underwent ABO-compatible (ABOc) LDKT during the same period. RESULTS: The mean follow-up periods of ABOi and ABOc groups were 31.9 ± 13.5 and 28.8 ± 14.4 months, respectively. In the ABOi group, no clinical acute rejection (AR) was noted and subclinical AR was observed in four patients without evidence of acute antibody-mediated rejection. In the ABOc group, clinical and subclinical AR developed in 3 and 10 patients, respectively. No significant difference was identified for the mean eGFR between the ABOi and ABOc groups (98.3 ± 48.8 vs. 86.9 ± 39.4, P = 0.452 at 3 months; 78.2 ± 21.2 vs. 79.7 ± 21.3, at 1 year, P = 0.830). Death-censored graft survival at follow-up was 100% in the ABOi group and 94.6% in the ABOc group. Patient survival during the follow-up period in both the groups was 100%. Late-onset neutropenia (LON) requiring granulocyte colony-stimulating factor occurred more frequently in the ABOi group than in the ABOc group (4 vs. 0 patients) (P < 0.001). CONCLUSIONS: Pre- and post-transplantation antibody removal is not a prerequisite for successful pediatric ABOi LDKT, at least in patients with a low anti-A/B IgG antibody titer. However, LON caused by rituximab should be monitored.

Donor-Recipient Body Weight Mismatch May Affect Glomerular Basement Membrane Thinning in Electron Microscopic Examination of 1-Hour Renal Allograft Biopsy Specimens.

BACKGROUND: Although an association between body weight mismatch and impaired graft function has been reported, few histologic studies have evaluated this issue, especially using electric microscopic analysis. During routine observations, we have noted a thin glomerular basement membrane (GBM) in the 1-hour biopsy specimen in cases with an overweight recipient and a lightweight donor. Therefore, we hypothesized that donor-recipient body weight mismatch affects the GBM thickness in the 1-hour biopsy specimen. The aim of the present study was to clarify the effect of donor-recipient body weight mismatch on the GBM thickness of the 1-hour biopsy specimen measured using electron microscopy. METHODS: We used an electron microscope to measure the GBM thickness of specimens at 1-hour post-transplantation (n = 24) and at 1 year post-transplantation (n = 17). The GBM thickness of cases with donor-recipient body weight mismatch was compared with those without mismatch. In accordance with a previous study, we defined a donor/recipient body weight ratio of less than 0.9 as donor-recipient body weight mismatch and a ratio of more than 0.9 as no mismatch. RESULTS: At 1-hour post-transplantation, the mean GBM was significantly thinner in the mismatch group than in the nonmismatch group. However, at 1-year post-transplantation, the mean GBM thickness did not significantly differ between the 2 groups. CONCLUSIONS: The GBM thickness at 1-hour post-transplantation is thinner in cases with donor-recipient body weight mismatch than in cases without mismatch. This implies that donor-recipient body weight mismatch may have to be considered when assessing donor-derived thin GBM disease using the 1-hour biopsy specimen.

Can Lipofuscin Deposition on Renal Allograft Tubular Epithelium Be a Surrogate Marker for Kidney Allograft Aging?

BACKGROUND: Lipofuscin is an indicator of aging. We examined the clinicopathologic significance of lipofuscin deposition in the renal tubules of renal allografts. METHOD: We analyzed allograft biopsy specimens from living kidney transplantations from January to December 2015. For controls, we analyzed native kidney biopsy specimens obtained from January 2015 to December 2016. We identified granules with a yellow-to-tan shade in renal tubules as lipofuscin. RESULTS: The donor age at transplantation was significantly older in lipofuscin deposition biopsy specimens than in those without, whereas the time after transplantation age was not different between the 2 groups with renal allografts. In native kidney biopsies, age at biopsy was significantly older in lipofuscin deposition biopsy specimens than in those without. We compared "massive lipofuscin deposition," defined as lipofuscin deposition on both sides of 3 or more renal tubules, and donor-age matched control allograft biopsies without lipofuscin deposition. Comparing these 2 groups, recipient age at transplantation was significantly older in the massive lipofuscin deposition group. CONCLUSION: Lipofuscin deposition on tubular epithelium is not a surrogate marker of aging of kidneys allografts, although lipofuscin deposition was significantly greater in older tissues from native kidneys. The older age of recipients may be associated with massive lipofuscin deposition in renal allografts.

Living-Donor Kidney Transplant With Preformed Donor-Specific Antibodies.

OBJECTIVES: We investigated outcomes in living-donor kidney transplant recipients with preformed donor-specific antibodies (detected with flow cytometry and specified with the LABScreen single antigen test) under desensitization pretransplant and immunosuppression posttransplant. MATERIALS AND METHODS: Of 15 recipients included, 8 had ABO-incompatible kidney transplant. Six patients had sensitization caused by pregnancy, 8 by blood transfusion, 5 by previous transplants, and 1 by unknown cause. Desensitization was initiated using calcineurin inhibitors, methylprednisolone, and mycophenolate mofetil 30 days pretransplant, with rituximab administered 1 and 10 days pretransplant. Patients underwent plasmapheresis 1, 3, and 5 days pretransplant. Antithymocyte globulin was admi nistered for 5 days posttransplant as induction therapy. At 3 and 12 months posttransplant, all recipients underwent protocol renal allograft biopsies, with donor-specific antibodies simultaneously measured with the single antigen test. RESULTS: T-cell complement-dependent cytotoxicity crossmatch was negative in all 15 recipients, but T-cell and B-cell flow cytometry was positive in 8 and 14 recipients, respectively. Anti-HLA class I antibodies became negative, except in 1 recipient 3 months posttransplant. Class II antibodies remained positive in 8 recipients 3 months posttransplant. No clinical or subclinical T-cell-mediated rejection occurred, but 1 recipient experienced clinical acute antibody-mediated rejection. At 3 and 12 months posttransplant, 8 and 5 recipients had subclinical acute antibody-mediated rejection. Cytomegalovirus test showed positivity in 14 recipients, but none developed cytomegalovirus disease. BK viremia was detected in 2 recipients, with 1 developing BK virus nephropathy, which was reversed by reducing immunosuppression. CONCLUSIONS: Transplant patients with preformed donor-specific antibodies showed good outcomes in terms of desensitization and immunosuppression. However, most anti-HLA class II donor-specific antibodies remained, and microvascular inflammation score could indicate long-term risk of renal allograft dysfunction.

Efficacy of 2 Doses of Rituximab on B-Cell and Antidonor Antibody and Outcomes of ABO-Incompatible Living-Donor Pediatric Kidney Transplant.

OBJECTIVES: Rituximab treatment strategies vary in ABOincompatible pediatric kidney transplant recipients. Here, we present the efficacy of 2 doses of rituximab and subsequent outcomes in ABO-incompatible pediatric kidney transplant patients. MATERIALS AND METHODS: Our study of ABO-incompatible pediatric kidney transplant recipients included 21 who were pretreated with desensitization that included 2 doses of 100 mg rituximab (rituximab group) at 10 and 1 day pretransplant and 14 who received splenectomy without rituximab (splenectomy group). Both groups received immunosuppression. Basiliximab was administered during transplant and 4 days posttransplant. Double-filtration plasmapheresis and/or plasma exchange procedures were performed pretransplant in those with higher antidonor antibody titers. CD19-positive and CD20-positive B cells were measured sequentially in the rituximab group. Maximum titers of antidonor antibody pre- and posttransplant, patient and graft survival, biopsy-proven rejection, and complications/infections were compared between groups. RESULTS: In the rituximab group, CD19- and CD20-positive B cells were depleted on transplant, persistently depleted at 3 months, and under 5% until 1 year posttransplant. Maximum titers of antidonor antibodies decreased significantly posttranplant in the rituximab (P < .001) but not in the splenectomy group (P = .174), with maximum titers posttransplant significantly lower than shown in the splenectomy group (P < .001). No rituximab patients had clinical rejection, but 5 splenectomy group patients had clinical T-cell-mediated rejection, with 2 also having antibody-mediated rejection. Six in the rituximab group had cytomegalovirus viremia but no cytomegalovirus disease; however, 5 splenectomy group recipients had cytomegalovirus disease and viremia. In the rituximab group, 3 had late-onset neutropenia. One child died of hypertrophic cardio myopathy with a functioning graft; all others survived with no failed grafts. All splenectomy group children survived, although 2 had deteriorated graft function. CONCLUSIONS: Two doses of rituximab were effective in long-term B-cell depletion to suppress antidonor antibodies. The possibility of late-onset neutropenia must be considered.

Vasa recta hyalinosis reflects severe arteriolopathy in renal allografts.

AIM: We examined the clinicopathologic significance of hyalinosis in the vasa recta in the medulla of allograft kidney biopsies. METHOD: We analyzed biopsy specimens from January 2010 to December 2015, obtained from both the cortex and medulla (including the vasa recta) ≥ 1 year after living-donor kidney transplantation. We excluded biopsy specimens from recipients who had undergone transplantation due to diabetic nephropathy or who had diabetes mellitus after transplantation. We evaluated hyaline arteriolopathy in the cortex using the aah score determined by the Banff 2007 classification. RESULT: Among 381 biopsy specimens obtained from 248 transplant recipients ≥ 1 year after transplantation, 36 specimens obtained from 34 recipients showed vasa recta hyalinosis (VRH) in the medulla. Among these 36 specimens, 17 had a score of aah3, 16 had a score of aah2, and 3 had a score of aah1. The incidence of VRH was 1.9% at ≥ 1 to < 4 years, 7.1% at ≥ 4 to < 8 years, and 50.0% at ≥ 8 years. The aah scores and the proportion of hyalinosis in the arteriolar media among all muscular arterioles in the cortex were significantly higher in the VRH group at ≥ 8 years in the late-phase biopsy (P < 0.01). The graft survival was worse in the VRH group (P = 0.024), although there was no significant difference in the graft survival between the ≥ aah2 and < aah2 groups at ≥ 8 years in the late-phase biopsy (P = 0.159). CONCLUSION: VRH in renal allografts reflects severe arteriolopathy of the cortex. VRH in the late-phase biopsy may be a prognostic factor for graft survival.

Novel technique for repair of arteriovenous fistula with aneurysm.

Aneurysm of autogenous arteriovenous fistula is a common complication in patients receiving hemodialysis. We present a novel method for repair of a case of aneurysm of arteriovenous fistula resulting from stenosis. A 52-year-old woman presented with aneurysm formation of the left upper arm arteriovenous fistula, with related numbness in the left hand. Clinical examination revealed a tense, pulsatile aneurysm above the brachiocephalic anastomosis. Ultrasound examination revealed an aneurysm (50 mm × 25 mm) with proximal stenosis and an arteriovenous fistula flow rate above 1200 mL/min. An incision was made lateral to the aneurysm from the brachiocephalic anastomosis to the proximal stenosis through the antecubital fossa. After exposure of the entire aneurysmal arteriovenous fistula, the narrowed segment, and the proximal cephalic vein, the aneurysm outflow was ligated and the narrowed segment was removed. A U-shaped incision was made on the aneurysm to create an aneurysmal flap (75 mm × 20 mm). The flap was tubularized after calibration of the lumen with a 14-Fr cannula. End-to-end anastomosis was performed between the distal tubularized flap and the proximal cephalic vein. Intra- and postoperative arteriovenous fistula flow rates were below 900 mL/min. After surgery, the remodeled arteriovenous fistula was immediately usable for hemodialysis with normal arteriovenous fistula flow in the upper arm. The repair technique achieved not only aneurysmorrhaphy but also created an autologous vascular graft as the bypass after removal of the narrowed segment. Moreover, this technique achieved reduced arterial inflow and is suitable for patients with conditions similar to those of this case.

Protocol graft biopsy in kidney transplantation.

Accurate interpretation of renal allograft biopsy is necessary to guide therapy, especially when an episode biopsy is taken to rescue the graft. Contrarily, a protocol biopsy is carried out routinely to identify baseline conditions (biopsy at 0 or 1 h), subclinical rejection, histological change under current immunosuppression regimen, drug nephrotoxicity, viral infection, and recurrence of glomerulonephritis. Semiquantitative scoring for active lesions including tubulitis, glomerulitis, capillaritis, arteritis, arteriopathy, and others such as polyomavirus infection are key factors in transplant pathology. Recently, the Banff classification has proposed several novel concepts focused on antibody-mediated rejection (ABMR). This review presents the interpretation of transplant pathology from rejection to infection, recurrence of glomerulonephritis, and drug nephrotoxicity, with a description of ABMR according to the 2013 and 2017 Banff classification.

Interlobular hyaline arteriopathy reflects severe arteriolopathy in renal allografts.

AIM: The present study was performed to examine the clinicopathological significance of hyaline deposits in the smooth muscle of the interlobular artery (interlobular hyaline arteriopathy [IHA]) in renal allografts. METHODS: Tissue specimens that included the interlobular artery from biopsies performed from January 2012 to December 2015, as well as specimens from biopsies performed ≥1 year after living kidney transplantation were analyzed. Biopsies of recipients with new-onset diabetes mellitus after transplantation were excluded, as well as those of recipients who had undergone transplantation because of diabetic nephropathy. Arteriolopathy was evaluated using the aah score determined by the Banff 2007 classification. RESULTS: In total, 51 specimens with IHA lesions were identified among 381 biopsies obtained from 243 recipients performed ≥1 year after kidney transplantation. Among these 51 biopsies, 18 specimens had a score of aah3, 29 had a score of aah2, and four had a score of aah1. The incidence of IHA lesions was 3.6% at ≥1 to <4 years, 18.5% at ≥4 to <8 years, and 54.1% at ≥8 years. Older kidney grafts exhibited more IHA lesions. Among the biopsy specimens obtained ≥8 years after transplantation, no significant differences in the recipient or donor age, duration after transplantation, or prevalence of hypertension were observed between the IHA and non-IHA groups. The aah scores were significantly higher in the IHA group ≥8 years after transplantation as determined by the mean score test (P < 0.01). CONCLUSION: IHA in renal allografts is associated with severe arteriolopathy.

Surgical Challenge in Pediatric Kidney Transplant Vascular Anastomosis.

During pediatric kidney transplant, surgical challenges occasionally occur. In particular, vascular anastomosis should be considered for children with small body weight < 12 kg, multiple renal arteries, vascular anomaly, and inferior vena cava occlusion. In pediatric patients, a living-donor renal graft is usually donated from a parent. Therefore, the renal artery and vein are too large to be anastomosed with the recipient's internal iliac artery and external iliac vein. In children who are > 12 kg, the renal artery and vein could be anastomosed with the external iliac artery and the external iliac vein. In children who are < 10 kg, the renal artery and vein should be anastomosed directly with the aorta and inferior vena cava. A pediatric transplant surgeon should consider arterial and venous anastomosis sites before transplant surgery. In small children with partial or total inferior vena cava occlusion, the venous anastomosis site should be evaluated. If the graft is placed on the left side, a venous graft must be used as a bridge between the renal vein and inferior vena cava. In 13 kidney transplants in children with inferior vena cava occlusion, 7 were on the left and 6 were on the right side. A patent segment of the inferior vena cava, the left original renal vein, an ascending lumbar vein, an azygos vein, the first graft renal vein, and a portal vein were used for venous anastomosis in 6, 2, 2, 1, 1 and 1 recipient, respectively. One child had graft loss due to renal vein thrombosis and one died of hemorrhage immediately posttransplant. Three had grafts with relatively long-term function, but these were lost due to chronic allograft nephropathy 100, 122, and 137 months posttransplant. However, the other 8 recipients have so far maintained graft function from 6 to 138 months since transplant.

Surgical Challenge in Pediatric Kidney Transplant: Lower Urinary Tract Abnormality.

Lower urinary tract abnormalities are difficult to resolve in pediatric kidney transplant patients. Measure of residual urine, voiding cystourethrography, retrograde urethrography, cystometry, electromyography of urethral external sphincter muscle, urethrometry, and uroflowmetry are the primary methods for evaluation of lower urinary tract abnormalities. Endoscopic resection or ablation of urethral valves is required in children with posterior urethral valve to treat obstruction, but bladder function does not always recover and may deteriorate to end-stage renal failure even after the obstruction is released. This bladder dysfunction in posterior urethral valve defines valve bladder syndrome. Vesicoureteral reflux caused by high vesical pressure can cause even worse renal graft function posttransplant. In our patient group, urinary diversion occurred with Mitrofanoff conduit using an appendix in 6 children, a Yang-Monti channel conduit using ileum in 1 patient, with cystostomy in 3 children, and with augmented cystoplasty in 9 children before or simultaneously with kidney transplant. These procedures should be selected based on the type of lower urinary tract abnormality including bladder function. Recently, we have preferred a continent diversion for self-catheterization in children with lower urinary tract abnormalities. We have conducted 9 augmented cystoplasty procedures using a portion of the sigmoid colon or ileum. Seventeen children retained their own bladders when the transplant ureter was implanted. Most patients needed clean intermittent catheterization, depending on the residual urine volume and a bladder function. Ten-year graft survival rate in kidney transplant in our department is 98% in 36 children with lower urinary tract abnormalities. Lower urinary tract abnormality is not always a risk factor for pediatric kidney transplant; however, a preoperative evaluation is important to choose the best option for urinary diversion.