Impact of pre-transplant biopsy on 5-year outcomes of expanded criteria donor kidney transplantation.

AIM: Compared to Standard Criteria Donors (SCD), Expanded Criteria Donor (ECD) kidneys are associated with poorer outcomes, although pre-transplant biopsy may mitigate risks. This study assessed 5-year outcomes of deceased-donor kidney transplant recipients, comparing recipients of ECD allografts evaluated histologically to recipients of SCD and ECD kidneys assessed clinically. METHODS: This is a single-centre retrospective study. From November 2005 to December 2009 (Era 1), donors were assessed clinically for suitability for kidney donation. From December 2009 to October 2017 (Era 2), kidneys from ECDs and diabetics underwent pre-transplant biopsy and were allocated based on Remuzzi score. Outcomes of Era 1 and 2 recipients were compared. RESULTS: ECD kidney transplantation increased from 30.4% to 40.0% from Era 1 to 2. Univariable Cox regression, stratified by transplant era, found that 5-year graft loss was highest with Era 1 ECD (HR 2.5, 95% CI 1.1-5.5, P = .027) while graft loss for Era 2 ECD recipients was similar to SCD recipients. There was no difference in 5-year recipient survival. Amongst Era 1 ECD recipients, 51.2% experienced rejection compared to 30.8-41.5% for other subgroups. Five-year eGFR was higher with Era 2 ECD at 48.4 (33.3-60.7) ml/min/1.73 m2 compared to 42.2 (35.8-57.3) ml/min/1.73 m2 for Era 1 ECD. However, these differences were not statistically significant. CONCLUSION: Introduction of pre-transplant biopsy assessment may be associated with improved outcomes of ECD kidney recipients such that they are now comparable to SCD kidney recipients, with benefits persisting over 5 years.

Outcomes of endovascular salvage of clotted arteriovenous access and predictors of patency after thrombectomy.

OBJECTIVE: This study aimed to report the outcomes of endovascular salvage of clotted arteriovenous (AV) accesses and to determine potential predictors of poor patency rates after thrombectomy. METHODS: Records of hemodialysis patients who underwent endovascular salvage of clotted AV access were reviewed retrospectively. Technical and clinical success rates, complication rates, and 3- and 6-month patency rates were determined. Multivariate analysis was performed to determine the predictors of patency after thrombectomy. RESULTS: A total of 294 patients underwent endovascular salvage of clotted AV access during the study period; 156 patients had arteriovenous fistula, whereas the remaining 138 were arteriovenous grafts (AVGs). The technical and clinical success rates were 96.3% and 93.2%; the major and minor complication rates were 0.7% and 9.9%. Post-thrombectomy primary, assisted primary, and secondary patency rates were 62.9%, 76.2%, and 77.6% at 3 months and 43.9%, 59.5%, and 61.6% at 6 months. The patency rates were significantly better for arteriovenous fistula than for AVG except for 6-month assisted primary and secondary patency. Multivariate Cox regression analysis showed that prior thrombosis within 90 days was significantly associated with loss of primary patency (hazard ratio [HR], 1.90; 95% confidence interval [CI], 1.21-2.98; P < .01), assisted primary patency (HR, 2.42; 95% CI, 1.42-4.13; P < .01), and secondary patency (HR, 2.52; 95% CI, 1.40-4.53; P < .01). Having an AVG was also negatively associated with primary patency. CONCLUSIONS: Most clotted AV accesses can be salvaged by endovascular technique. Recurrent thrombosis within 90 days is associated with poor short- and long-term patency even after successful endovascular reinterventions.

Impact of simulation-based learning on immediate outcomes of temporary haemodialysis catheter placements by nephrology fellows.

AIM: Traditional apprenticeship model (AM) of teaching in invasive procedures such as temporary haemodialysis catheter (THDC) insertion can result in propagation of errors and complications. Simulation-based learning (SBL) offers standardization of skills and allows trainees to repeatedly practice invasive procedures prior to performing them on actual patient. METHODS: Retrospective cohort study of first-, second- and third-year Nephrology Fellows from a tertiary teaching hospital from September 2008 to September 2015. The intervention group (n = 9) received simulation training in ultrasound-guided THDC placement. The historical control group (n = 12) received training through traditional AM. The primary and secondary outcomes were the immediate complications and success rates of THDC insertion. RESULTS: A total of 2481 THDCs were placed in 1787 patients. Success rate of internal jugular THDC placement for AM vs. SBL Fellow was 99.8% versus 100% (P = 0.90), while the success rate for femoral THDC placement was 99.6% versus 99.2% (P = 0.53). SBL Fellows reported fewer overall peri-procedure complications (8.3% vs. 11.2%, P = 0.02) and mechanical complications (1% vs. 2.4%, P = 0.02) compared to AM Fellows. The rate of reported technical difficulty was similar (7.5% vs. 9.2%, P = 0.17). After adjusting for side and site of THDC placement, body mass index and laboratory indices, THDC inserted by AM Fellows were independently associated with increased overall peri-procedure complications (OR = 1.396, 95% CI: 1.052-1.854, P = 0.02) and mechanical complications (OR = 2.481, 95% CI: 1.178-4.810, P = 0.02). CONCLUSIONS: Simulation-based learning was associated with lower procedure related complications and should be an integral component in the teaching of procedural skills in Nephrology.

Warfarin related nephropathy: a case report and review of the literature.

BACKGROUND: Warfarin related nephropathy is one of the potential complications of warfarin therapy. Despite the well described histological entity, the clinical course and approach to warfarin related nephropathy in patients requiring life-long anticoagulation is however not well described in the literature. CASE PRESENTATION: We report the clinical course of a 56 years old Chinese lady who presented with over anti-coagulation and acute kidney injury while on warfarin therapy for permanent atrial fibrillation and mechanical valve replacement. Renal biopsy was performed as the acute kidney injury was persistent despite normalization of the International Normalized Ratio and the diagnosis of warfarin related nephropathy was made. Temporary interruption of anti-coagulation, in combination with oral N-acetylcysteine resulted in subsequent stabilization of renal function. CONCLUSION: The diagnosis of warfarin induced nephropathy should be considered in patients presenting with unexplained acute kidney injury and over anti-coagulation. Awareness of this clinical entity is important for clinician managing anti-coagulation therapy and renal function should be monitored regularly in patients who are on warfarin therapy.

Predictive value of donor kidney quality assessment and risk quantification scores on 5-year outcomes of deceased donor kidney transplantation.

BACKGROUND: Due to the excess demand for deceased donor kidneys, risk quantification scores were developed to help with kidney allocation. The kidney donor risk index (KDRI) is used in the US kidney allocation system. We currently use expanded criteria (UNOS) and Remuzzi scoring for allocation of deceased donor kidneys and the utility of KDRI in our cohort is unknown. We aim to evaluate the association of KDRI with relation to 5 year graft and patient survival. METHODS: Retrospective cohort study of 225 adults who received a deceased donor kidney transplant between 1 Nov 2005 and 30 June 2014. Patients were followed up for 5 years or until graft-loss or death. Implant biopsies of donor kidneys were done and the Remuzzi score was calculated. RESULTS: The median age was 48 (IQR 42, 52.5) years and 50.7% were male. KDRI-USA, KDRI-THAI, and KDRI-AUST were found to have no correlation with 5 year graft survival. Donor characteristics which define an expanded criteria donor kidney, not associated with 5 year graft survival are age (p = 0.58), terminal creatinine (p = 0.71) and history of hypertension (p = 0.35). Donor cerebrovascular accident (CVA) as a cause of death (p = 0.02) and Remuzzi score were associated with graft survival at 5 years, with 75.8% with Remuzzi score ≤ 3 vs 24.2% with Remuzzi score of > 3 achieving 5 year graft survival (p = 0.001). CONCLUSION: The association of KDRI with graft and patient survival was not demonstrated in our cohort. Histological assessment of the transplant kidney remains the best method of predicting long-term survival during donor selection.

25-OH vitamin D threshold for optimal bone mineral density in elderly patients with chronic kidney disease.

Introduction: Vitamin D deficiency is common in chronic kidney disease (CKD) and is associated with lower bone mineral density (BMD), decreased muscle strength, and increased hip fracture risk. Guidelines have suggested targeting 25-OH vitamin D (25(OH)D) levels between 20 and 30 ng/ml. However, vitamin D metabolism is altered in CKD, and threshold levels for optimal BMD are unknown. Methods: We included 1097 patients with hip fractures. CKD was defined as estimated glomerular filtration rate <60 ml/min/1.73 m (Mucsi et al., Clin. Nephrol., 2005, 64(4), 288-294) and low BMD defined as T score ≤ -2.5 at femoral neck. We assessed the association of 25(OH)D with low BMD in patients with and without CKD: using the conventional threshold 25(OH)D < 30 ng/dl, as well as a new threshold. Results: CKD was present in 479 (44%) patients. Using a threshold of 25(OH)D < 30 ng/ml, there were no significant differences in patients with CKD and low BMD when compared to the other groups. We identified 27 ng/ml as a better threshold with the Youden index. Using 25(OH)D < 27 ng/ml as a threshold, 360 of 482 patients (74.7%) with low 25(OH)D had low BMD, compared to only 185/276 (67%) of patients with adequate vitamin D, p = 0.02, which was irrespective of the presence or absence of CKD. Furthermore, patients with CKD and 25(OH)D < 27 ng/ml had a higher odds ratio of mortality upon follow-up, 1.61, 95% CI: 1.08-2.39, compared to those with CKD and 25(OH)D ≥ 27 ng/ml. Conclusion: We find that 25(OH)D < 27 ng/ml is associated with low BMD in patients with and without CKD. Further prospective studies targeting vitamin D repletion to at least 27 ng/ml and the outcome of hip fractures will be useful to validate these findings.

Association of Bone Mineral Density With Fractures Across the Spectrum of Chronic Kidney Disease: The Regina CKD-MBD Study.

BACKGROUND: Recent studies have demonstrated that measurement of areal bone mineral density by dual-energy x-ray absorptiometry (DXA) predicts fractures in patients with chronic kidney disease (CKD). However, whether fracture risk prediction through bone mineral density (BMD) is enhanced due to the assessment of biochemical markers of chronic kidney disease and mineral and bone disease (CKD-MBD) or clinical risk factors is not clear. We hypothesized that in a select cohort of patients managed in a CKD clinic, that combining T-Scores with biochemical markers would optimize fracture discrimination than using DXA alone. OBJECTIVE: To examine the relationships among BMD, biochemical markers of CKD-MBD, and fracture risk across Kidney Disease Improving Global Outcomes (KDIGO) glomerular filtration rate (GFR) categories G3a to G5. DESIGN: Retrospective study. SETTING: Patients were recruited from the multidisciplinary CKD clinic, Regina General Hospital, Canada. PATIENTS: A total of 374 patients who received a DXA scan upon initial referral to Regina Multidisciplinary CKD Program from January 31, 2001 to January 31, 2010, were included in this study. The patients were followed for a total of 5 years. METHODS: We conducted a retrospective review of 374 consecutive patients who underwent DXA imaging at the point of entry into our multidisciplinary CKD program. Areal BMD, T- and Z-Scores were obtained at the lumbar spine, total hip, mean of left and right femoral neck, and the one-third radius. We collected data on demographic, cross-sectional biochemical markers of mineral metabolism and fractures (identified through self-reported questionnaires, hospital electronic medical records, and physician billing records). We were able to gather data on 8/11 variables of Fracture Risk Assessment (FRAX) tool. RESULTS: In our cohort, 14.3% of GFR categories G3a and G3b, 15.7% of GFR category G4, and 19.7% of GFR category G5 experienced a clinical fracture during the study period. On multivariate analysis, each decline of 1.0 SD in total hip BMD T-Score was associated with a significant increase in the risk of fracture (OR = 1.46, 95% confidence interval [CI], 1.12-1.89). Adding CKD-MBD markers and clinical risk factors did not further contribute to the model. Low BMD was the only independent risk factor for fracture in patients with CKD. LIMITATIONS: Self-reporting by patients and administrative records were used to identify fractures. We did not perform spine imaging to ascertain morphometric vertebral fractures. We were unable to gather all 11 variables of FRAX score and information on ethnicity. We were unable to capture site of fracture (hips, spine, etc) from billing records. Albumin excretion rates were not collected at baseline. Treatment of the underlying bone disease with pharmacotherapeutic agents may have attenuated patients' fracture risk and thus underestimated the association between BMD and future fracture. CONCLUSIONS: Our findings confirm that BMD predicts fracture. The addition of cross-sectional CKD-MBD parameters and clinical risk factors to BMD did not add to fracture prediction. Prospective studies should investigate the utility of longitudinal biochemical markers on improving fracture risk assessment.

CONTEXTE: Des études récentes ont démontré qu'il était possible de prédire les fractures chez les patients atteints d'insuffisance rénale chronique (IRC) avec une mesure de la densité minérale osseuse (DMO) surfacique par absorptiométrie biénergétique à rayons X (DXA). On ignore cependant si la valeur prédictive de la DMO est améliorée par l'analyze des biomarqueurs des troubles minéraux et osseux associés à l'IRC (TMO-IRC) ou des facteurs de risque cliniques. Nous avons émis l'hypothèse que, dans une cohorte choisie de patients suivis en clinique d'IRC, la combinaison des scores T et des marqueurs biochimiques optimiserait la discrimination des fractures par rapport à l'utilization de la DXA seule. OBJECTIF: L'étude visait à établir un lien entre la DMO, les biomarqueurs des TMO-IRC et le risque de fractures chez les patients présentant un débit de filtration glomérulaire (DFG) de catégories G3a à G5 selon la classification du KDIGO (Kidney Disease Improving Global Outcomes). TYPE D'ÉTUDE: Étude rétrospective. CADRE: Les patients ont été recrutés à la clinique multidisciplinaire d'IRC de l'hôpital général de Régina (Canada). SUJETS: Ont été inclus les 374 patients ayant passé un test d'imagerie DXA entre le 31 janvier 2001 et le 31 janvier 2010 lors de leur aiguillage vers le program multidisciplinaire d'IRC de Régina. Les patients ont été suivis sur une période de cinq ans. MÉTHODOLOGIE: Nous avons mené une étude rétrospective portant sur 374 patients consécutifs examinés par DXA à leur admission au program. La DMO surfacique et les scores T et Z ont été mesurés au rachis lombaire, à la hanche totale, à la moyenne des cols fémoraux droit et gauche, et au tiers du radius. On a recueilli les caractéristiques démographiques des patients, les données sur les marqueurs biochimiques transversaux du métabolisme minéral et les fractures subies (recensées à l'aide d'un questionnaire d'auto-déclaration et par consultation des dossiers médicaux électroniques et des registres de facturation des médecins). Nous sommes parvenus à rassembler des données sur huit variables des onze de l'outil FRAX (Fracture Risk Assessment tool). RÉSULTATS: Dans notre cohorte, 14,3 % des patients avec un DFG de catégorie G3a-G3b, 15,7 % des patients avec un DFG de catégorie G4 et 19,7 % des patients avec un DFG de catégorie G5 ont subi une fracture clinique au cours de la période d'étude. Dans l'analyze multivariée, chaque déclin d'un point d'écart-type au score T de la DMO à la hanche a été associé à une augmentation significative du risque de fracture (RR = 1,46; IC 95 %: 1,12-1,89). L'ajout des marqueurs des TMO-IRC et des facteurs de risque cliniques n'a pas contribué davantage au modèle. Une faible DMO s'est avérée le seul facteur de risque indépendant de subir une fracture chez les patients atteints d'IRC. LIMITES: Les fractures ont été identifiées à partir des dossiers administratifs et par auto-déclaration des patients. Nous n'avons pas procédé à l'imagerie de la colonne vertébrale pour confirmer les fractures vertébrales morphométriques. Nous n'avons pas été en mesure de rassembler les onze variables du score FRAX ni les informations sur l'origine ethnique des patients. Les registres de facturation ne nous ont pas permis d'établir le site de la fracture (hanche, rachis ou autre). Les taux initiaux d'excrétion de l'albumine n'ont pas été mesurés. Le traitement de l'ostéopathie sous-jacente à l'aide d'agents pharmacothérapeutiques pourrait avoir atténué le risque de fracture des patients et ainsi, sous-évalué l'association entre la DMO et de futures fractures. CONCLUSION: Nos résultats confirment que la DMO est prédictive du risque de fractures. L'ajout des paramètres transversaux des TMO-IRC et des facteurs de risque cliniques à la mesure de DMO n'en a pas amélioré la valeur prédictive. Des études prospectives devraient examiner l'intérêt des marqueurs biochimiques longitudinaux pour améliorer l'évaluation du risque de fracture.

Laparoscopic nephrectomy: new standard of care?

OBJECTIVE: The pace of implementation of a laparoscopic nephrectomy programme is affected by factors including surgical expertise, case load, learning curves and outcome audits. We report our experience in introducing a laparoscopic nephrectomy programme over a 3-year period. METHODS: From January 2001 to December 2003, 187 nephrectomies were performed (105 by conventional surgery, 82 by laparoscopy). Hand-assisted laparoscopy was used predominantly. The indications for surgery, factors affecting the approach and outcome parameters were studied. A cost comparison was made between patients with similar-sized renal tumours undergoing laparoscopic versus open surgery. RESULTS: Most operations were performed for malignancy in both the open (70%) and laparoscopic (67%) surgery groups. The laparoscopic approach was most commonly used in upper tract transitional cell cancers (TCCs; 70% of 30 patients) and benign pathologies (49% of 35 patients), followed by radical nephrectomies (34% of 99 patients) and donor nephrectomies (44% of 23 patients). There was a rapid rise in laparoscopic surgeries, from 30% in 2001 to 58% in 2002. The median hospital stay was 5.8 days in the laparoscopic group and 8.1 days in the open surgery group. The procedure cost for laparoscopic surgery was 4,943 dollars compared with 4,479 dollars for open surgery. However, due to a shorter hospital stay, the total hospital cost was slightly lower in the laparoscopic group (7,500 dollars versus 7,907 dollars). CONCLUSION: The laparoscopic approach for various renal pathologies was quickly established with a rapid increase in the number of laparoscopic procedures.