Multidetector row computed tomography evaluation of potential living laparoscopic renal donors: the story so far

High Perirenal Fat Volume Affect Negatively Renal Function in Living Renal Transplantation

OBJECTIVE

We aimed to investigate the effect of perirenal fat volume (PFV) on graft functions by calculating the PFV of donor kidney with routine computed tomography before renal transplantation.

METHODS

From May 2019 to December 2020, a total of 54 living donors and recipients who met the criteria for kidney donor were included in the study. Left donor nephrectomy was performed to all donors. Data of age, sex, body mass index (BMI), PFV of the donors, estimated glomerular filtration rate (eGFR), and serum creatinine measurement data of the recipients were recorded. Serum creatinine and eGFR of the recipients were recorded at the 12th month controls. The patients were sorted into 2 groups (G) according to their GFR values. G1, GFR <60 mL/min/1.73 m²; G2, GFR ≥ 60 mL/min/1.73 m².

RESULTS

There was no difference in terms of recipient sex, recipient age, donor sex, recipient BMI, and donor BMI between the 2 groups. The mean of PFV was higher in G1 and was statistically significant (P= 0.01). The ability of the donor BMI and PFV to predict G2 was evaluated by receiver operating characteristic curve analysis. It was determined that PFV predicted G2 to be statistically significant. In the multivariate logistic regression analysis, PFV (odds ratio = 0.988, 95% GA = 0.977-0.999, P = 0.03) was found as an independent predictor of G2.

CONCLUSIONS

In conclusion, our study showed PFV as an independent risk factor for low eGFR, revealing that the previously documented relevance of increased BMI with a low eGFR can be partially explained by PFV.

Simplified method to measure renal volume: the best correction factor for the ellipsoid formula volume calculation in pretransplant computed tomographic live donor

OBJECTIVE

To find an optimal correction factor that will produce a near-real renal volume calculation using the ellipsoid formula.

METHODS

We retrospectively studied 79 multidetector computed tomography (MDCT) examinations for potential renal donor assessment. The renal volumes were calculated using the slice summation method, the ellipsoid formula with π/6 as correction factors as well multiple other correction factors for statistical analysis. A paired Student t test was used for evaluating the volumes calculated with different correction factors and the volumes calculated by the slice summation method.

RESULTS

The ellipsoid formula using correction factor 0.524 underestimates the renal volume by approximately 22.2% with statistical difference compared with the slice summation method (P<.05). There is no statistical difference when using correction factor in the range of 0.664 to 0.686 (P>.05). Further subgroup analysis of gender and laterality was performed and revealed no statistical difference. Using a mean value of 0.674 or 0.67 as correction factor results in renal volumes that are 100% and 99.5%.

CONCLUSION

To avoid underestimation of the renal volume by the ellipsoid method, acceptable correction factors are in the range of 0.664 to 0.686. We suggest the use of a mean value of 0.674 or 0.67 as correction factor when using the ellipsoid formula.

Prevalence of renal artery and kidney abnormalities by computed tomography among healthy adults

BACKGROUND AND OBJECTIVES

Management of incidental renal artery and kidney abnormalities in patients undergoing computed tomography scans is a clinical challenge because their frequency in healthy subjects has not been precisely estimated. Therefore, the prevalence and management of these abnormalities were determined among a large cohort of potential kidney donors undergoing protocol evaluations.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

All patients at the Mayo Clinic who underwent computed tomographic angiography and urography as part of their kidney donor evaluation between 2000 and 2008 were identified. Radiographic reports were abstracted for abnormalities of the renal arteries and kidneys. The prevalence of radiographic abnormalities was stratified by age and gender, and the effect on approval for kidney donation was determined.

RESULTS

Among 1957 potential kidney donors, the mean +/- SD age was 43 +/- 12 years, and 58% were women. The most common abnormalities were kidney stones (11%), focal scarring (3.6%), fibromuscular dysplasia (2.8%), and other renal artery narrowing or atherosclerosis (5.3%). Fibromuscular dysplasia, focal scarring, parenchymal atrophy, and upper tract dilation were more common in women. Renal artery narrowing, focal scarring, and indeterminate masses increased with age. Overall, 25% of potential donors had at least one abnormality. However, these incidental radiographic abnormalities contributed to exclusion from donation in only 6.7% of potential donors.

CONCLUSIONS

Incidental radiographic abnormalities of the renal arteries and kidneys are common. The majority of imaging findings are not perceived to be harmful enough to prevent kidney donation, but future studies are needed to determine their clinical relevance.

Diagnostic accuracy of a volume-rendered computed tomography movie and other computed tomography-based imaging methods in assessment of renal vascular anatomy for laparoscopic donor nephrectomy

To evaluate the diagnostic accuracy of computed tomography (CT)-based imaging methods for assessing renal vascular anatomy, imaging studies, including standard axial CT, three-dimensional volume-rendered CT (3DVR-CT), and a 3DVR-CT movie, were performed on 30 patients who underwent laparoscopic donor nephrectomy (10 right side, 20 left side) for predicting the location of the renal arteries and renal, adrenal, gonadal, and lumbar veins. These findings were compared with videos obtained during the operation. Two of 37 renal arteries observed intraoperatively were missed by standard axial CT and 3DVR-CT, whereas all arteries were identified by the 3DVR-CT movie. Two of 36 renal veins were missed by standard axial CT and 3DVR-CT, whereas 1 was missed by the 3DVR-CT movie. In 20 left renal hilar anatomical structures, 20 adrenal, 20 gonadal, and 22 lumbar veins were observed during the operation. Preoperatively, the standard axial CT, 3DVR-CT, and 3DVR-CT movie detected 11, 19, and 20 adrenal veins; 13, 14, and 19 gonadal veins; and 6, 11, and 15 lumbar veins, respectively. Overall, of 135 renal vascular structures, the standard axial CT, 3DVR-CT, and 3DVR-CT movie accurately detected 99 (73.3%), 113 (83.7%), and 126 (93.3%) vessels, respectively, which indicated that the 3DVR-CT movie demonstrated a significantly higher detection rate than other CT-based imaging methods (P < 0.05). The 3DVR-CT movie accurately provides essential information about the renal vascular anatomy before laparoscopic donor nephrectomy.