Radiologic evaluation of the kidney transplant donor and recipient.

The kidney is the most common solid organ transplant globally and rates continue to climb, driven by the increasing prevalence of end stage renal disease (ESRD). Compounded by advancements in surgical techniques and immunosuppression leading to longer graft survival, radiologists evermore commonly evaluate kidney transplant patients and candidates, underscoring their role along the transplant process. Multiphase computed tomography (CT) with multiplanar and 3D reformatting is the primary method for evaluating renal donor candidates, detailing renal size, vascular/collecting system anatomy, and identifying significant pathologies such as renal vascular diseases and nephrolithiasis. Ultrasound is the preferred initial postoperative imaging modality for graft evaluation due to its low cost, accessibility, noninvasiveness, and lack of radiation. CT and magnetic resonance imaging (MRI) may be useful adjunctive imaging techniques in diagnosing transplant pathology when ultrasound alone is not diagnostic. Kidney transplant complications are categorized by an approximate timeline framework, aiding in differential diagnosis based on onset, duration, and severity and include perinephric fluid collections, graft compression, iatrogenic injuries, vascular compromise, graft rejection, and neoplastic processes. This review discusses imaging strategies and important findings along the transplant timeline, from donor assessment to long-term recipient complications.

A Three-Year Experience With Overseas Kidney Transplantation in a Tertiary Transplant Center in Saudi Arabia.

Background Overseas kidney transplantation is known to be associated with adverse outcomes. In this study, we aim to present a detailed analysis of our three years of experience with overseas kidney transplantation at one of the largest kidney transplant referral sites in the Kingdom of Saudi Arabia. Materials and methods A retrospective cohort study included patients who underwent kidney transplantation overseas and were subsequently followed up at King Abdulaziz Medical City from January 2016 to July 31, 2019. In addition, we compared the outcomes of the patients who underwent kidney transplantation overseas with a cohort of patients who were transplanted locally within the same period. Patients in both cohorts had to have at least one year of follow-up post-transplantation. Results We included a total of 51 patients who underwent kidney transplantation overseas. The mean age of the cohort was 44.7 years, and 69% were male. Almost 60% of the cohort had one or no comorbidity prior to transplant, with hypertension (84%) and diabetes mellitus (37%) being the leading comorbidities. The cause of end-stage kidney disease was unknown in 55% of our patients. In those who had an identifiable cause, lupus nephropathy and diabetes were the most common causes of kidney failure. In comparison with the locally transplanted cohort, no difference was detected between these groups in their baseline characteristics, type or number of comorbidities, medical or surgical complications postoperatively, and one-year mortality. However, we found that the graft rejection rate was significantly higher in patients transplanted overseas (OR=5.4, p<0.001). In addition, the proportion of patients who received anti-thymocyte globulin (ATG) induction was also less in the group with overseas kidney transplantation (58% vs. 22%, p<0.001). Conclusion Overseas transplantation is associated with an increased risk for graft rejection. Our study suggests that overseas kidney transplantation is possibly driven by a lack of donors, especially cadaveric. Counseling patients about risks associated with overseas kidney transplantation and encouraging the public to register for organ donation after death may help curb out this practice.

Central fibrous areas: changes in glomerular vascular pole lesions associated with age and disease.

PURPOSE: Central fibrous areas (CFAs) are small, hyalinotic, monotonous nodular areas observed in glomerular vascular pole lesions. We attempted to clarify the relationship between CFA formation and age in healthy kidneys and in those affected by immunoglobulin A (IgA) nephropathy. METHODS: Zero-hour biopsy specimens from living renal donors (135 cases) and IgA nephropathy biopsy specimens (67 cases) were collected retrospectively. We observed each biopsy specimen and determined the total number of glomeruli, total level of glomerulosclerosis, number of observable glomerular vascular poles, number of glomeruli with CFAs, serum creatinine level, and estimated glomerular filtration rate (eGFR). Additionally, we calculated the glomerular sclerosis rate (GSR), vascular pole appearance rate (PAR), and CFA rate (CFAR) to evaluate the relationship between these factors and patient age. RESULTS: There was a significant negative correlation between patient age and eGFR for both the zero-hour (p < 0.0001 in Spearman, p = 0.0009 in multiple regression, the same hereafter) and IgA (p = 0.0022, p = 0.0001) groups. In the zero-hour group, we observed a significant positive correlation between patient age and GSR (p = 0.0001, p < 0.0001); however, there was no such correlation in the IgA group. In both groups, there was a significant positive correlation between patient age and CFAR (zero-hour group: p = 0.0003, p = 0.0091, IgA group; p < 0.0001, p = 0.0004). The slope of the regression line of the IgA group formula was also significantly higher than that of the zero-hour group formula (p < 0.01). CONCLUSION: These findings indicate that CFA may be a useful indicator of kidney aging, especially in patients with kidney disease caused by IgA nephropathy.

Descripción de costos del tratamiento analgésico protocolizado con catéter epidural versus la analgesia convencional para la nefrectomía abierta del donador renal en el Instituto Mexicano del Seguro Social / Cost description of protocolized analgesic treatment with epidural catheter versus conventional analgesia for open kidney donor nephrectomy in the Mexican Institute of Social Security

Resumen: Introducción: El dolor posterior a la nefrectomía abierta en donadores renales trasciende en la recuperación plena de las actividades de la vida diaria y expone un impacto económico en las instituciones de salud. Objetivo: Describir el costo de la analgesia protocolizada durante el período postoperatorio inmediato del paciente donante renal. Material y métodos: Realizamos un ensayo clínico controlado, aleatorizado, no ciego que comparó dos tratamientos analgésicos diferentes: uno protocolizado versus la analgesia convencional mediante un modelo de análisis de costos desde la perspectiva institucional. Resultados: En promedio, la analgesia protocolizada obtuvo un costo mayor con 53.25 US$ (52.34-53.79) versus el tratamiento analgésico convencional con 18.84 US$ (4.55-19.34), U = -6.0, p < 0.001. Sin embargo, 89.2% de los pacientes con analgesia protocolizada calificó como excelente esta intervención a diferencia de 41.2% de los pacientes que recibieron el tratamiento analgésico convencional, χ2 = 18.78; p < 0.001. Del mismo modo, los pacientes con analgesia protocolizada estuvieron más satisfechos reportando una mediana: (Me) = 10; (Percentil25 = 10 - Percentil75 = 10) en comparación con el otro tratamiento: Me = 8; (Percentil25 = 8 - Percentil75 = 9) (U = -5.9, p < 0.001). Conclusiones: En pacientes sometidos a nefrectomía abierta para donación renal, el uso de analgesia protocolizada con catéter epidural demostró una diferencia clínica y estadísticamente significativa con respecto a los reportes de dolor, eficacia y un mayor grado de satisfacción, aunque no disminuyó los costos de la atención analgésica durante el postoperatorio inmediato.

Abstract: Introduction: Pain in renal donors after open nephrectomy, transcends in full recovery of activities in daily life and exposes an economic impact in health institutions. Objective: To describe the costs of protocolized analgesia during the immediate postoperative period of renal donor patient. Material and methods: We conducted a longitudinal, randomized, non-blinded clinical trial which compared two different analgesic treatments: one protocolized versus conventional analgesia through a cost analysis model from the Institutional Social Security perspective. Results: In average, protocolized analgesia obtained a higher cost with 53.25 US$ (52.34-53.79) opposed to the conventional analgesia treatment with 18.84 US$ (4.55-19.34); U = -6.0, p < 0.001. However, 89.2% of the patients in protocolized analgesia qualified this intervention as excellent compared to the conventional treatment with only 41.2%, χ2 = 18.78; p < 0.001. Similarly, patients in protocolized analgesia were more satisfied with a reported median (Me) = 10; (25th percentile = 10-75th percentile = 10) compared to those who received conventional treatment, Me = 8; (25th percentile = 8-75th percentile = 9) (U = -5.9, p < 0.001). Conclusions. The use of Protocolized Analgesia with epidural catheter showed a clinical and statistically significant difference concerning to pain, efficacy and a greater satisfaction report in patients undergoing open nephrectomy for renal donation, although does not decrease the costs of analgesic care during immediate postoperative period.

Vascular imaging in renal donors.

Imaging plays a crucial role in pre-transplant evaluation to enhance the probability of a successful outcome. Its aim is to define kidney and vascular anatomy and to assess potential pathologies. Each modality has advantages and disadvantages. Computed tomography angiography (CTA) is the most commonly used imaging modality, however, magnetic resonance angiography (MRA) can be used in selected cases. The purpose of this review article is to provide an overview of available imaging modalities, their benefits, risks, advantages, and disadvantages. Imaging findings that indicate particular anomalies and pathologies that may affect living renal donor selection will be discussed.

Angiotomografía renal en el donante vivo y su correlación con la ablación quirúrgica / Computed tomography renal angiography of living donors and its correlation with surgery

Objetivos: Determinar la precisión de la angiotomografía renal (ATR) en la evaluación del sistema arterial y las variantes anatómicas en el donante vivo, con la correlación con su ablación quirúrgica. Materiales y métodos: Se evaluaron retrospectivamente los pacientes sometidos a nefrectomía laparoscópica como donantes vivos renales y sus ATR, entre 2014 y 2016 en nuestra Institución. Se utilizó análisis estadístico descriptivo para presentar los resultados. En la ATR se evaluaron: número de arterias renales principales, presencia y número de arterias polares y alteraciones del calibre de la arteria renal. Resultados: Se incluyeron 21 pacientes sometidos a nefrectomía laparoscópica como donantes vivos, 10 mujeres y 11 hombres (entre 23 y 61 años). En todos los casos se realizó la ablación del riñón izquierdo. De los 21 pacientes analizados, 15 no presentaron variantes anatómicas ni alteraciones del calibre en la ATR (una arteria renal principal, sin polares). Estos mismos hallazgos se certificaron en la ablación. En un caso, la ATR observó doble arteria renal principal con el mismo hallazgo quirúrgico; y en tres casos la ATR reconoció una única arteria polar, las cuales se corroboraron en la ablación. En estos 19 casos se demostró correlación entre la ATR y la ablación, con una precisión del 90,4% En los 2 casos restantes, hubo discrepancias. Conclusión: El conocimiento detallado del sistema arterial es necesario para la planificación quirúrgica de la nefrectomía laparoscópica del donante vivo renal. La angiotomografía renal constituye el método de elección para su evaluación, demostrando muy buena correlación entre sus hallazgos y los de la ablación.

Objective: To determine the accuracy of computed tomography renal angiography (CTRA) in the assessment and diagnosis of arterial vascular anatomy of the kidney and its variations in living kidney donors, with its correlation in harvesting kidneys. Materials and methods: Patients who had undergone laparoscopic nephrectomy as living kidney donors and their CTRA were retrospectively evaluated between 2014 and 2016 in our institution. Results are presented using statistical descriptive analysis. The following were assessed in the CTRA report: number of main renal arteries, presence and number of accessory polar arteries, and anomalies related to renal artery calibre. Results: Of the 21 patients that had undergone laparoscopic nephrectomy as living donors, there were 10 female and 11 male donors (age range 23 - 61 years). Renal harvesting included left kidney in all cases. In 15 cases, no anatomical variations or arterial renal dilations were found in computed tomography renal angiography (CTRA): (one main renal artery, without accessories arteries). The same findings were certified during the surgery. In one case CTRA showed a double renal artery, and the same finding occurred in the surgical harvesting; and three cases in which one single polar accessory artery was certified at surgery. An overall accuracy of 90.4% for CTRA was obtained in 19 cases. In the remaining 2 cases, a discrepancy was found. Conclusion: Detailed knowledge of the renal arterial anatomy is important for the preoperative evaluation of the laparoscopic nephrectomy in living renal donors. Computed tomography renal angiography (CTRA) is the technique of choice for these patients, as it demonstrates a high correlation between tomography findings and surgery harvesting.

3.0Tesla magnetic resonance angiography (MRA) for comprehensive renal evaluation of living renal donors: pilot study with computerized tomography angiography (CTA) comparison.

PURPOSE: Most living related donor (LRD) kidneys are harvested laparoscopically. Renal vascular anatomy helps determine donor suitability for laparoscopic nephrectomy. Computed tomography angiography (CTA) is the current gold standard for preoperative imaging; magnetic resonance angiography (MRA) offers advantages including lack of ionizing radiation and lower incidence of contrast reactions. We evaluated 3.0T MRA for assessing renal anatomy of LRDs. MATERIALS AND METHODS: Thirty consecutive LRDs underwent CTA followed by 3.0T MRA. Data points included number and branching of vessels, incidental findings, and urothelial opacification. Studies were individually evaluated by three readers blinded to patient data. Studies were reevaluated in consensus with discrepancies revealed, and final consensus results were labeled "truth". RESULTS: Compared with consensus "truth", both computed tomography (CT) and magnetic resonance imaging were highly accurate for assessment of arterial and venous anatomy, although CT was superior for detection of late venous confluence as well as detection of renal stones. Both modalities were comparable in opacification of lower ureters and bladder; MRA underperformed CTA for opacification of upper urinary tracts. CONCLUSIONS: 3.0T MRA enabled excellent detection of comprehensive renal anatomy compared to CTA in LRDs.

Renal Pretransplantation Work-up, Donor, Recipient, Surgical Techniques.

Renal transplant is the single best treatment of end-stage renal disease. Computed tomography (CT) is an excellent method for the evaluation of potential renal donors and recipients. Multiphase CT is particularly useful because of detailed evaluation of the kidneys, including the vascular anatomy and the collecting system. MR imaging has no ionizing radiation, but is limited for stone detection, making it a less preferred method of evaluating donors. Preoperative knowledge of the renal vascular anatomy is essential to minimize risks for donors. Imaging evaluation of recipients is also necessary for vascular assessment and detection of incidental findings.

Waiting for a kidney from a deceased donor: an interpretative phenomenological analysis.

Demand for kidneys from deceased donors far outstrips supply. Despite this, there appears to be little research that focuses solely on the experience of waiting for a kidney from a deceased donor. This study uses the qualitative methodology interpretative phenomenological analysis to explore the lives of 10 people on the transplant list, with the aims of illuminating the potential psychological challenges those on the list may face during this time, and providing information to help clinicians more fully support such people in the future. Two themes connected to the experience of waiting - adjustment to the uncertainty of waiting and thinking about receiving a kidney from a living donor - are presented here. Participants describe a sense of confusion and uncertainty around life on the list, and discuss their strategies for dealing with this. Novel complexities around the ambiguous challenge of receiving an organ from a deceased donor are revealed. It is recommended that health care teams provide a forum for this patient group to work through these feelings of confusion and ambiguity.

Semiautomated CT-Based Quantification of Donor Kidney Volume Applied to a Predictive Model of Outcomes in Renal Transplantation.

OBJECTIVE: The purpose of this study was to assess the use of semiautomated CT-based quantification of renal graft volume as a preoperative predictor of graft function. MATERIALS AND METHODS: All transplants over a 3-year period in which donors underwent CT and for which recipient outcomes were available were included. Two blinded readers used a commercially available reconstruction tool to independently measure donated kidney cortical volume and total parenchymal kidney volume. Transplant characteristics obtained by chart review included subject demographics, recipient pretransplant weight, immunologic matching, and recipient creatinine values at multiple time points. Intraclass correlation of measurements by the two readers was calculated. The ratios between donated kidney cortical volume and recipient pretransplant weight were correlated with graft function over 24 months and used in logistic regression models to calculate the odds of development of diminished renal function. RESULTS: After application of the inclusion and exclusion criteria, 153 transplants were included in the study. Donated kidney cortical and total parenchymal volume measurements had high correlation (R > 0.9) and high reproducibility (intraclass correlation coefficient, 0.93-0.94). Unadjusted correlations existed between estimated glomerular filtration rate (eGFR) and the ratio between donated kidney cortical volume and recipient pretransplant weight 12 months (R = 0.8489) and 24 months (R = 0.6839) after transplant. After adjustment for transplant parameters, recipients in the highest tertile for ratio between donated kidney cortical volume and recipient pretransplant weight (2.7 mL/kg) had higher mean eGFR values at all time points in the 24 months than did recipients in the lower tertiles (1.2 and 1.6 mL/kg). Recipients in the highest tertile had a significantly lower risk of development of diminished renal function 12 and 24 months after transplant (adjusted odds ratios, 0.25 at 12 months [95% CI, 0.09-0.66]; 0.27 at 24 months [95% CI, 0.10-0.71]). CONCLUSION: The CT-derived ratio between donated kidney cortical volume and recipient pretransplant weight is a noninvasively and readily obtained reproducible biomarker that is predictive of 12- and 24-month renal transplant outcomes.

MDCT evaluation of potential living renal donor, prior to laparoscopic donor nephrectomy: What the transplant surgeon wants to know?

As Laparoscopic Donor Nephrectomy (LDN) offers several advantages for the donor such as lesser post-operative pain, fewer cosmetic concerns and faster recovery time, there is growing global trend towards LDN as compared to open nephrectomy. Comprehensive pre-LDN donor evaluation includes assessment of renal morphology including pelvi-calyceal and vascular system. Apart from donor selection, evaluation of the regional anatomy allows precise surgical planning. Due to limited visualization during laparoscopic renal harvesting, detailed pre-transplant evaluation of regional anatomy, including the renal venous anatomy is of utmost importance. MDCT is the modality of choice for pre-LDN evaluation of potential renal donors. Apart from appropriate scan protocol and post-processing methods, detailed understanding of surgical techniques is essential for the Radiologist for accurate image interpretation during pre-LDN MDCT evaluation of potential renal donors. This review article describes MDCT evaluation of potential living renal donor, prior to LDN with emphasis on scan protocol, post-processing methods and image interpretation. The article laid special emphasis on surgical perspectives of pre-LDN MDCT evaluation and addresses important points which transplant surgeons want to know.

Current status of low dose multi-detector CT in the urinary tract.

Over the past several years, advances in the technical domain of computed tomography (CT) have influenced the trend of imaging modalities used in the clinical evaluation of the urinary system. Renal collecting systems can be illustrated more precisely with the advent of multi-detector row CT through thinner slices, high speed acquisitions, and enhanced longitudinal spatial resolution resulting in improved reformatted coronal images. On the other hand, a significant increase in exposure to ionizing radiation, especially in the radiosensitive organs, such as the gonads, is a concern with the increased utilization of urinary tract CT. In this article, we discuss the strategies and techniques available for reducing radiation dose for a variety of urinary tract CT protocols with metabolic clinical examples. We also reviewed CT for hematuria evaluation and related scan parameter optimization such as, reducing the number of acquisition phases, CT angiography of renal donors and lowering tube potential, when possible.

CT Angiography for Living Kidney Donors: Accuracy, Cause of Misinterpretation and Prevalence of Variation

OBJECTIVE: To determine the accuracy of the use of multi-detector row CT (MDCT) to predict vascular anatomy in living kidney donors and to reveal the prevalence of vascular variations in a Korean population. MATERIALS AND METHODS: A total of 153 living kidney donors that had undergone preoperative CT and nephrectomy, either with open or laparoscopic surgery, were selected retrospectively. The initial CT results were compared with the surgical findings and repeated review sessions of CT scans were performed to determine the causes of mismatches in discordant cases. RESULTS: The accuracy of CT angiography was 95% to predict the number of renal vessels. Four arteries and two veins were missed during the initial CT interpretation due to perception errors (for two arteries and two veins) and technical limitations (two arteries). The prevalence of multiple renal arteries and veins, early branching of a renal artery and late confluence of a renal vein were 31%, 5%, 12%, 17%, respectively. The circumaortic renal vein and the bilateral inferior vena cava were found in two cases each (1.3%). One case (0.7%) each of a retroaortic renal vein and a supradiaphragmatic originated renal artery were found. CONCLUSION: MDCT provides a reliable method to evaluate the vascular anatomy and variations of living kidney donors.

El estudio del donador vivo para trasplante renal / Evaluation of the living kidney donor

Currently, due to the deficit of cadaveric tissues available for transplantation and due to the long waiting list for a kidney transplant, there is a clear tendency towards living donor kidney transplantations. Most donors are genetically related. Living donation should be considered a gift of extraordinary value, and should be made easy whenever a suitable donor is available. Worldwide, the number of patients on the waiting lists for a kidney transplantation has increased, in the last decades. Renal transplantation with living donor kidneys, is currently considered the best treatment for patients with end stage renal failure, due to the improved short and long term survival benefits over dialysis treatment. Since considerable difference exist between countries in the evaluation and selection criteria for kidney donors, especially in selected patients such as older donors and those with associated comorbid conditions, it is necessary to discuss and establish minimal selection criteria for this cases. A common trend includes a complete clinical record, laboratory and radiologic evaluation which are described in detail in this paper. We also discuss the increasing acceptance of older kidney donors as well as the acceptance of individuals with comorbidities (such as obesity, hipertensión, hyperglucemia, lithiasis and cancer) that were previously considered as not eligible for kidney donation.

Actualmente, por la falta de órganos para trasplante renal provenientes de cadáveres, y debido al largo tiempo de espera por un riñón, existe una tendencia a realizar trasplantes renales utilizando riñones procedentes de donadores vivos. La mayoría de los donadores son familiares del receptor. La donación de órganos debe considerarse como un regalo con un valor extraordinario y debe facilitarse a los candidatos a donación. En todo el mundo se ha observado un aumento en el número de personas en la lista de espera para un trasplante renal. El trasplante renal de donador vivo se considera actualmente como el mejor método de tratamiento en pacientes con insuficiencia renal terminal, debido a que ofrece la mayor supervivencia a corto y largo plazos. En vista de que existen diferencias significativas en los criterios de selección y evaluación de donadores renales, en especial en un grupo selecto de pacientes añosos o con enfermedades asociadas, es indispensable establecer criterios mínimos de selección. Todos los donadores deberán contar con una historia clínica completa y exámenes de laboratorio y gabinete que permitan su evaluación integral. Estos estudios se describen con detalle en este artículo. También se discuten los criterios para donadores renales con ciertas comorbilidades (obesos, hipertensos, hiperglucémicos, con litiasis y neoplasias) que previamente se descartaban como candidatos para donación.