Prevalence of Incidental Findings on Multidetector Computed Tomography in Potential Nephrectomy Donors: A Prospective Observational Study

Reproducibility of Computed Tomography Volumetry for Predicting Post-Donation Remnant Renal Function: A Retrospective Analysis

BACKGROUND

Recent studies indicate that split renal function calculated by computed tomography (CT) volumetry is equally or more useful than that calculated by nuclear renography for donated kidney side selection. However, it remains unclear if CT volumetry accurately reflects split renal function as measured by nuclear renography. Therefore, this study aimed to evaluate the reproducibility of CT volumetry.

METHODS

Data from 141 donors who underwent living donor nephrectomy at Nara Medical University from March 2007 to June 2021 were reviewed. The correlation and agreement between the predicted postdonation estimated glomerular filtration rate (eGFR) by ^99mTc-diethylenetriamine penta-acetic acid (DTPA) scintigraphy and by CT volumetry were evaluated by the Pearson's correlation coefficient and Bland-Altman analysis, respectively. Moreover, a comparison in split renal function categorization between ^99mTc-DTPA scan and CT volumetry was performed.

RESULTS

A total of 133 donors were included in the analysis. There was high correlation between the predicted postdonation eGFR by ^99mTc-DTPA scintigraphy and by CT. Moreover, there was agreement in the predicted postdonation eGFR between ^99mTc-DTPA scintigraphy and CT volumetry (Bland-Altman analysis [bias, 95% limits of agreement]; 0.83%, -5.6% to 7.3%). However, in one of 17 donors with absolute split renal function greater than 10% by ^99mTc-DTPA scintigraphy, this clinically significant difference was missed by CT volumetry.

CONCLUSION

There are donors for whom a clinically significant split renal function is not accurately reflected in CT volumetry. Future studies need to amend this discrepancy.

Birt-hogg-Dubé Syndrome Incidentally Identified in a Potential Liver Donor

BACKGROUND

Birt-Hogg-Dubé Syndrome (BHDS), an autosomal dominant hereditary condition, occurs due to mutations in the gene encoding folliculin (FLCN) in the short arm of the 17th chromosome characterized by lung cysts with specific skin findings and renal cell carcinoma. Patients have usually complaints related to dyspnea and chest pain due to pneumothorax but they may be asymptomatic due to wide phenotypic heterogeneity. Herein, we report the imaging findings of a case 32-year-old male with BHDS without any symptom who was diagnosed incidentally by computed tomography (CT) due to organ donation.

CASE REPORT

In a 32-year-old male patient evaluated as a potential liver donor, CT was performed for preoperative preparation. The patient's medical history was unremarkable. In the CT examination, multiple air cysts of different sizes in both lungs were observed and also, a 7-cm solid renal mass of the right kidney was observed in the dynamic examination. Due to a large number of lung cysts and the presence of solid renal tumors at a young age, BHDS was considered. The patient underwent partial nephrectomy, and the pathology result was hybrid oncocytic-chromophobe renal cell carcinoma. In the genetic examination, a heterozygous germline mutation was detected in the 11th exon of the FLCN gene.

CONCLUSION

While potential organ donors are generally healthy and asymptomatic individuals, incidental lesions can be detected in the donor organ or other organs in the examination area during radiological imaging. Although most incidental lesions are benign, important clinical conditions can rarely be observed, as in our case. Familial and syndromic conditions should also be considered for the presence of solid renal masses incidentally detected at a young age. To the best of our knowledge, this is the first reported case of BHDS in English literature who was diagnosed incidentally on computed tomography for being a living liver donor.

Assessment of renal vascular anatomy on multi-detector computed tomography in living renal donors

BACKGROUND

Prospective renal donors are a select population of healthy individuals who have been thoroughly screened for significant comorbidities before they undergo multi-detector computed tomography angiography and urography (MDCT).

PURPOSE

The aim of this study is to describe the anatomy of potential living renal donor subjects using MDCT over a 2-year period. The primary objective is to identify the renal arterial anatomy variations, with a secondary objective of identifying venous and collecting system/ureteric variations.

MATERIALS AND METHODS

A prospective study was performed of prospective living kidney transplant donors at a national kidney transplant centre. Study inclusion criteria were all potential kidney donors who underwent MDCT during the living-donor assessment process over a 2-year period.

RESULTS

Our cohort included 160 potential living donors who had MDCT; mean age was 45.6 years (range, 21-71). Two renal arteries were identified on the left in 40 subjects (25%) and on the right in 42 subjects (26.3%). A total of 3 or more renal arteries were identified on the left in 7 subjects (4.4%) and on the right in 7 subjects (4.4%). On the left, the distances between multiple arteries ranged from 1 mm to 43 mm, and on the right, they were 1 mm to 84 mm.

CONCLUSIONS

Conventionally described anatomy was only seen on the left side in 70.6% and 69.4% on the right side of subjects. Single renal arteries are seen in 54.4% showing that conventional anatomy has a relatively low incidence.

Impact of Incidental Findings During the Evaluation of Live Kidney Donors on Post-Transplant Outcomes: A Single Center Analysis

BACKGROUND

A careful assessment of a living donor is mandatory to minimize the short- and long-term risk related to kidney donation. In this study, we evaluated the incidence of incidental findings (IFs) in a large population of potential living kidney donors. Moreover, this study evaluated if the presence of IFs could influence the chance of living kidney donation and post-transplant outcomes.

METHODS

One hundred and sixty consecutive potential prospective living kidney transplant donors, who underwent a multidetector computed tomography angiography (MDCTA), were included in the study. An IF was defined as an incidentally discovered mass or lesion, detected by computed tomography angiography during the imaging evaluation of potential living donors. Clinical outcomes of living donors with IF were compared with those without IF.

RESULTS

In 10 patients (6.2%) an incidental finding was detected at MDCTA assessment. Among the 10 patients presenting with an IF, 7 patients (4.3%) were excluded from the living donation: 2 patients with an adrenal lesion, 3 patients with cancer, and 2 patients with a large (>8 cm) renal cyst. Graft and patient survival of kidney transplant recipients of donors with IFs were not significantly different to those receiving a kidney from living donors without IFs.

CONCLUSIONS

Incidental findings are frequently discovered during living kidney donor evaluation. Whereas most are asymptomatic or not clinically relevant, predonation screening could identify potentially life-threatening diseases at an earlier stage, allowing for a more radical treatment.