CT volumetry is superior to nuclear renography for prediction of residual kidney function in living donors

Living kidney donor evaluation commonly includes nuclear renography to assess split kidney function and computed tomography (CT) scan to evaluate anatomy. To streamline donor workup and minimize exposure to radioisotopes, we sought to assess the feasibility of using proportional kidney volume from CT volumetry in lieu of nuclear renography. We examined the correlation between techniques and assessed their ability to predict residual postoperative kidney function following live donor nephrectomy. In a cohort of 224 live kidney donors, we compared proportional kidney volume derived by CT volumetry with split kidney function derived from nuclear renography and found only modest correlation (left kidney R²=26.2%, right kidney R²=26.7%). In a subset of 88 live kidney donors with serum creatinine measured 6 months postoperatively, we compared observed estimated glomerular filtration rate (eGFR) at 6 months with predicted eGFR from preoperative imaging. Compared to nuclear renography, CT volumetry more closely approximated actual observed postoperative eGFR for Chronic Kidney Disease Epidemiology Collaboration (J‐test: P=.02, Cox–Pesaran test: P=.01) and Mayo formulas (J‐test: P=.004, Cox–Pesaran test: P<.001). These observations support the use of CT volumetry for estimation of split kidney function in healthy individuals with normal kidney function and morphology.     

Intravenous digital subtraction angiography and helical computed tomography in evaluation of living renal donors

OBJECTIVES: The present study was carried out to evaluate the accuracy of helical computed tomography (CT) and intravenous digital subtraction angiography (IV-DSA) on anatomical assessment of renal vasculature for living renal donors. METHODS: Forty-two healthy potential renal donors were prospectively evaluated and 35 subsequently underwent donor nephrectomy after helical CT and IV-DSA evaluation. The vascular and non-vascular findings were compared between the findings on helical CT, IV-DSA and surgery. RESULTS: Ten prehilar branches and five accessory renal arteries were found at nephrectomy. Overall, operative findings agreed with the findings by IV-DSA in 89% and by helical CT in 83%. In delineating accessory arteries, IV-DSA had a sensitivity of 60% and specificity of 97%, whereas helical CT had a sensitivity of 40% and specificity of 100%. In delineating prehilar branches, IV-DSA had a sensitivity of 90% and specificity of 100%, whereas helical CT had a sensitivity of 70% and specificity of 100%. Accessory arteries and prehilar branches that were not detected by helical CT or IV-DSA, were less than 2 mm in diameter and did not require vascular reconstruction. Renal veins were delineated in 63% by IV-DSA, whereas they were clearly imaged by helical CT in all cases, including a case with a circumaortic renal vein. Non-vascular findings were obtained in 64% by helical CT, including two renal tumors. None of these findings were obtained by IV-DSA. CONCLUSION: Helical CT and IV-DSA provide comparably sufficient information on renal artery vasculature. However, helical CT provides significantly more information on venous and non-vascular findings as a single-imaging modality.     

Psychosocial evaluation of Chinese living related kidney donors

Zhao W‐Y, Zeng L, Zhu Y‐H, Wang L‐M, Zhou M‐S, Han S, Zhang L. Psychosocial evaluation of Chinese living related kidney donors.
Clin Transplant 2010: 24: 766–771. © 2009 John Wiley & Sons A/S. Abstract: Background: Although living kidney transplantation has numerous advantages over cadaveric transplantation, donor apprehension remains a problem. This study investigated psychosocial features and quality of life in Chinese living kidney donors after transplantation procedures. Methods: Participants were 84 donors interviewed during follow‐up after donation. Sociodemographic characteristics were evaluated by a 22‐item questionnaire. Social support, quality of life, depression, and anxiety were objectively measured with the Social Support Rating Scale for Chinese, the Short‐Form 36 Health Survey, the modified Beck Depression Inventory, and the Self‐Rating Anxiety Scale questionnaire, respectively. Results: All donors volunteered without pressure from families or recipients. Altruistic motives were the main impetus for donation, and donors had good social support. Living transplantation affected donors’ quality of life, with a slight negative effect on some physical aspects. There were no major depressive or anxiety disorders following donation. Conclusions: Living kidney donation was a generally positive experience without evidence of major psychological disturbance. However, considering the limited size and duration of our study, we recommend careful follow‐up of all donors. We also recommend provision of social support services and removal of financial disincentives for donors.     

Assessment of live kidney donors by magnetic resonance angiography: reliability and impact on outcomes

Abstract: Background:  Kidney allograft retrieval from live donors requires accurate determination of kidney anatomy prior to surgery, particularly the arterial supply. Traditionally, conventional angiography has been used to obtain this information. Magnetic resonance angiography (MRA) offers a non-invasive, cost-effective alternative, but has been considered to be less accurate. Despite this criticism, many centers have moved to MRA screening of potential kidney donors. The objective of this study is to evaluate our experience of the reliability of MRA in determining the arterial anatomy of living kidney donors as compared to the intra-operative findings.
Methods:  We performed a retrospective review of gadolinium-enhanced, ultra-fast, three-dimensional, spoiled gradient-echo MRA in live kidney donors in the Southern Alberta Transplant Program and compared these results with the intra-operative findings during nephrectomy, as the gold standard.
Results:  Of the 66 patients, an accessory renal artery was found intra-operatively in eight cases; two of which were erroneously diagnosed as normal by MRA. The negative predictive value for MRA was 0.97, false-negative rate was 0.25, and sensitivity was 0.75. No patient experienced side-effects from the MRA procedure. No donor needed conversion to open nephrectomy because of an undetected accessory renal artery. One allograft with an accessory renal artery developed thrombosis of the lower pole of the kidney despite arterial reconstruction. Kidney function in the recipient of this allograft was excellent and there was no urinary leak.
Conclusion:  In our hands, MRA determined the vascular anatomy of potential kidney donors with an acceptable negative predictive value of 97%.     

Risks and complications in 160 living kidney donors who underwent nephroureterectomy.

BACKGROUND: The rate of living donor renal transplantations has increased. However, in view of the possible complications, the question as to whether the condition of the recipient justifies operation of the donor still remains unanswered. The present retrospective study evaluates the perioperative and post-operative risks and complications for the donor at a single major transplantation centre. METHODS: From 1994 to 2001, 160 live donor nephroureterectomies were performed. The median age of living donors was 51 years (range 21-77 years); 19 patients were older than 61 years. After confirming blood group compatibility and negative cross-match, donors underwent an extensive medical and psychological examination. Comorbidities and anatomical features of the donor were evaluated and the impact they may have on the outcome was determined. The nephroureterectomies were performed transperitoneally, with the right kidney being preferred. Pre-operative, intraoperative and post-operative complications were documented. Serum creatinine levels as well as new-onset proteinuria or hypertension were used as criteria for assessing long-term renal function. RESULTS: Complications were observed in 41 donors: 35 were minor and six were major (splenectomy; revisions due to liver bleeding, incarcerated umbilical hernia or infected pancreatic pseudocyst; pneumothorax; and acute renal failure). No patient died. Multiple arteries (14 patients), significant renal artery stenosis (two patients) and additional risk factors (e.g. increased age and previous operations) did not affect the complication rate. In the post-operative follow-up period of 0.5-62 months (mean: 38 months), renal function remained stable in all donors. CONCLUSIONS: Living donor nephrectomy appears to be a safe intervention in specialized centres, where it entails a low morbidity for the donor. Even in high-risk donors, long-term complications were not observed.     

Preoperative evaluation of living kidney donors using multirow detector computed tomography: comparison with digital subtraction angiography and intraoperative findings

To assess the accuracy of multirow detector computed tomography (MDCT) for the evaluation of renal anatomy for preoperative donor assessment in living related kidney transplantation. MDCT-scans (4- and 16-slice-CT) of 51 consecutive living kidney donors (age, 51.6 +/- 9.7 years; range, 28-68 years) were analysed by three blinded observers and compared with digital subtraction angiography (DSA) and surgery. Contrast-enhanced MDCT was performed with 1 mm slice thickness reconstruction interval during arterial and venous phases. Supernumerary renal arteries, veins, early branching of vessels and abnormalities of the ureters were documented. The overall accuracy of computed tomography angiography (CTA) for detection and classification of surgically relevant arterial variants was 97% (99/102). The interpretation of 16-channel MDCT images was correct in all cases (accuracy, 100%), while the four-channel CTA had three incorrect results regarding the differentiation of early branching vessels from double renal arteries (accuracy, 93%). The overall accuracy of DSA was 91%. Renal vein abnormalities were correctly diagnosed with MDCT in 100% compared with 89% correct findings with DSA. There were three kidneys with incomplete ureter duplication, detected both with MDCT and DSA. MDCT demonstrated superior accuracy compared with non-selective DSA for the preoperative assessment of renal anatomy in living kidney donors; and for the distinction of supernumerary arteries versus early branching patterns, 16-channel CTA data were better than those of the four-channel system.     

Age alone is not a contraindication to kidney donation: Outcomes of donor nephrectomy in the elderly

With increasing organ demand, living kidney donation from older donors (>60‐years‐old) has become more common. Between 1975 and 2014, 3752 donor nephrectomies (DN) were performed at University of Minnesota; 167 (4.5%) were >60‐years‐old Short‐ and long‐term outcomes were compared between contemporaneous >60‐years‐old and <60‐years‐old donors. On univariate analysis, >60‐years‐old were more likely to have had prior abdominal surgery and hypertension; and less likely to smoke. Baseline estimated glomerular filtration rate (eGFR) was lower in >60‐years‐old (80 ± 16 vs 101 ± 26 mL/min/1.73 m²; P < .001). Intraoperative and postoperative complications were similar, except a higher prevalence of <30 day ileus (3% vs 7%; P = .021) and longer postoperative length of stay (LOS) (4.2 vs 4.6 days; P = .005). On multivariate analysis, <30 day ileus and LOS continued to be significantly greater for >60‐years‐old After >20 years post‐DN, systolic blood pressure was significantly higher among >60‐years‐old (142 vs 125 mm Hg; P < .001) and HTN was diagnosed earlier (9 vs 14 years). After donation, eGFR was significantly lower for >60‐years‐old but slope of eGFR and rates of end‐stage renal disease (ESRD) were not significantly different >20 years post‐DN. Thus, kidney donation among carefully selected >60‐years‐old poses minimal perioperative risks and no added risk of long‐term ESRD.     

Multidetector CT angiography in living donor renal transplantation: accuracy and discrepancies in right venous anatomy

Kulkarni S, Emre S, Arvelakis A, Asch W, Bia M, Formica R, Israel G. Multidetector CT angiography in living donor renal transplantation: accuracy and discrepancies in right venous anatomy.
Clin Transplant 2011: 25: 77–82. © 2010 John Wiley & Sons A/S. Abstract: Multidetector computed tomography (MDCT) angiography is a reliable technique for assessing pre‐operative renal anatomy in living kidney donors. The method has largely evolved into protocols that eliminate dedicated venous phase and instead utilize a combined arterial/venous phase to delineate arterial and venous anatomy simultaneously. Despite adoption of this protocol, there has been no study to assess its accuracy. To assess whether or not MDCT angiography compares favorably to intra‐operative findings, 102 donors underwent MDCT angiography without a dedicated venous phase with surgical interpretation of renal anatomy. Anatomical variants included multiple arteries (12%), multiple veins (7%), early arterial bifurcation (13%), late venous confluence (5%), circumaortic renal veins (5%), retroaortic vein (1%), and ureteral duplication (2%). The sensitivity and specificity of multiple arterial anomalies were 100% and 97%, respectively. The sensitivity and specificity of multiple venous anomalies were 92% and 98%, respectively. The most common discrepancy was noted exclusively in the interpretation of right venous anatomy as it pertained to the renal vein/vena cava confluence (3%). MDCT angiography using a combined arterial/venous contrast‐enhanced phase provides suitable depiction of renal donor anatomy. Careful consideration should be given when planning a right donor nephrectomy whether the radiographic interpretation is suggestive of a late confluence.     

Impact of screening for metabolic syndrome on the evaluation of obese living kidney donors

Background

We report our experience with metabolic syndrome screening for obese living kidney donor candidates to mitigate the long-term risk of CKD.

Paired kidney donation by shipment of living donor kidneys

It is apparent from calculations that for paired kidney donation programs, a national program will provide optimum benefit. To obviate major problems associated with donors traveling long distances, we propose shipping donor kidneys. Evidence is provided from the United Network for Organ Sharing (UNOS) Kidney Transplant Registry, that 14,873 immediate functioning kidneys from deceased head-trauma donors with an average cold ischemia time of 18.3 h had 85.7% three-yr graft survival compared with 87.8% survival of 23 369 transplants from living donors with 2.4 h of ischemia. Grafts from 10,368 deceased donors with 13-24 h cold ischemia time had three-yr graft survival of 82.6% compared with 84.2% for 1153 transplants with up to six h cold ischemia time. After adjusting for major confounding factors, cold ischemia does not significantly influence graft survival. We conclude that shipment of donor kidneys can be performed safely and will significantly increase paired donor transplants.     

Lack of health insurance in living kidney donors

Living donors are recommended to receive lifelong routine health maintenance after donation. There has been little examination of health insurance status among living donors, despite the fact that lack of health insurance is likely to impede donors' ability to obtain long-term healthcare post-donation. We performed a retrospective chart review for all living kidney donors at our institution between 2004 and 2008 to determine insurance status, demographic, socioeconomic, and basic health characteristics. Twenty-three percent of donors were uninsured at the time of donation. Odds of being uninsured were significantly lower in donors who were older than 40 yr of age or who had at least a college education, and significantly higher in donors who were non-white, non-English-speaking, or non-US citizens. Odds of being uninsured did not differ according to whether donors were obese, hypertensive, or smokers. On multivariate analysis, only non-white race, non-US citizenship, and education level less than a college degree were associated with lack of insurance. Lack of health insurance is more prevalent in living kidney donors than in the general US population. Its disproportionate impact on minorities, non-citizens, and the less well educated is greater than that in the general population.     

Diagnostic accuracy of 64-MDCT angiography in the preoperative evaluation of renal vessels and compared with laparotomy findings in living donor kidney

Introduction: Multidetector-row computed tomography (MDCT) angiography is a reliable technique in preoperative renal anatomy evaluation in live renal donors. Objectives: To investigate the accuracy of early arterial phase findings and compares them with intraoperative findings. Methods: In this prospective study, 100 potential live donors undergoing preoperative MDCT and nephrectomy during 2010–2013 were included. The examination was performed with a 64-detector scanner including early arterial and venous phase. MDCT angiography started by bolus tracking and venous phase was acquired 9?s after arterial phase. Anatomical findings and vein and artery attenuation values were recorded and arterial phase findings were compared with intraoperative findings. Results: All anatomical findings reported by MDCT in early arterial phase were confirmed by intraoperative findings with sensitivity of 100%. Right renal vein was supernumerary in 17 cases and left renal vein was circumaortic in 3 and retroaortic in 5 cases. Renal arteries had early branching in 13, two arteries in 12 and accessory in 8 cases. Vein and artery attenuation values had significant difference between early arterial and venous phase (p?0.001). Conclusion: Early arterial phase has similar results to venous phase in preoperative evaluation and intraoperative findings and could be used alone to reduce radiation dose.     

Factors associated with perceived donation‐related financial burden among living kidney donors

The perception of living kidney donation–related financial burden affects willingness to donate and the experience of donation, yet no existing tools identify donors who are at higher risk of perceived financial burden. We sought to identify characteristics that predicted higher risk of perceived financial burden. We surveyed 51 living kidney donors (LKDs) who donated from 01/2015 to 3/2016 about socioeconomic characteristics, predonation cost concerns, and perceived financial burden. We tested associations between both self‐reported and ZIP code–level characteristics and perceived burden using Fisher's exact test and bivariate modified Poisson regression. Donors who perceived donation‐related financial burden were less likely to have an income above their ZIP code median (14% vs. 72%, P = .006); however, they were more likely than donors who did not perceive burden to rent their home (57% vs. 16%, P = .03), have an income <$60 000 (86% vs. 20%, P = .002), or have had predonation cost concerns (43% vs. 7%, P = .03). Perceived financial burden was 3.6‐fold as likely among those with predonation cost concerns and 10.6‐fold as likely for those with incomes <$60 000. Collecting socioeconomic characteristics and asking about donation‐related cost concerns prior to donation might allow transplant centers to target financial support interventions toward potential donors at higher risk of perceiving donation‐related financial burden.     

Outcome of living kidney donors left with multiple renal arteries

Individuals with kidneys having ≥ 2 arteries appear to have an increased incidence of hypertension. Whether kidney donors in whom the remaining kidney has ≥ 2 arteries are at increased risk of hypertension is unknown. Therefore, we studied 3685 kidney donors to determine whether donors left with a kidney having ≥ 2 arteries were at increased risk of hypertension, impaired renal function, or death. Cohorts were assigned based on our practice pattern and the anatomy of the donated kidney. Of the 3685 donors, 1211 were estimated to have a remaining kidney with ≥ 2 arteries. Mean follow-up time for the single-artery group was 14.1 (± 11.0) yr and 15.3 (± 11.2) yr for the ≥ 2 artery group. Six-month hospital readmission rate was 1.4% and 1.2%, hypertension was noted in 22.4% and 21.8% and proteinuria in 9.7% and 9.6%, and estimated glomerular filtration rate at last follow-up was 62 (± 28) and 62 (± 16) for single vs. ≥ 2 renal artery groups, respectively. Our data suggest no adverse clinical sequelae nor any decrease in long-term survival for donors left with a kidney having ≥ 2 renal arteries.