Accuracy of three-dimensional CT angiography for preoperative vascular evaluation of laparoscopic living renal donors

​Venous anomalies in renal transplantation: an accessory left-sided IVC in a live kidney donor

Duplication of the inferior vena cava (IVC) resulting in an accessory left-sided IVC is a relatively rare vascular anomaly with a reported prevalence of 0.7%. Radiologically, a duplicated left-sided IVC is usually seen as a continuation of the left common iliac vein, crossing anterior to the aorta at the level of the renal vein to join the right-sided IVC. We present a rare case in which an accessory left-sided IVC was discovered intraoperatively, in a 47-year-old living donor, posing significant intraoperative challenges regarding extraction and subsequent transplantation.

Mesenteric lymph duct drainage attenuates acute lung injury in rats with severe intraperitoneal infection

The purpose of this study is to investigate the hypothesis that the mesenteric lymphatic system plays an important role in acute lung injury in a rat model induced by severe intraperitoneal infection. Male Wistar rats weighing 250∼300 g were randomly divided into 3 groups and subjected to sham operation, intraperitoneal infection, or mesenteric lymphatic drainage. The activity of diamine oxidase (DAO) and myeloperoxidase (MPO) were measured by enzymatic assay. The endotoxin levels in plasma, lymph, and bronchoalveolar lavage fluid (BALF) were evaluated using the limulus amoebocyte lysate reagent. The cytokines, adhesion factors, chemokines, and inflammatory factors were detected by ELISA. TLR-4, NF-kB, and IRAK-4 were analyzed by Western blotting. Compared with sham-operated rats, rats with intraperitoneal infection had increased MPO and decreased DAO activity in intestinal tissues. Mesenteric lymph drainage reduced the alterations in MPO and DAO activity induced by intraperitoneal infection. The MPO activity in pulmonary tissue and the permeability of pulmonary blood vessels were also increased, which were partially reversed by mesenteric lymph drainage. The endotoxin levels in lymphatic fluid and alveolar perfusion fluid were elevated after intraperitoneal infection but decreased to control levels after lymph drainage. No alterations in the levels of plasma endotoxin were observed. The number of neutrophils was increased in BALF and lymph in the infected rats, and was also reduced after drainage. Lymph drainage also decreased the levels of inflammatory cytokines, chemokines, and adhesion factors in the plasma, lymph, and BALF, as well as the levels of TLR-4, NF-kB, and IRAK-4 in pulmonary and intestinal tissues. The mesenteric lymphatic system is the main pathway involved in early lung injury caused by severe intraperitoneal infection, in which activation of the TLR-4 signal pathway may play a role.

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.

Anatomic variations of the renal vessels pertinent to transperitoneal vascular control in the management of trauma

BACKGROUND

Operative exposure and control of the renal vessels through a transabdominal retroperitoneal (TARP) approach has been advocated for emergency management of renal trauma. The pertinent anatomic variations of the renal vasculature have not been well described.

METHODS

In 190 cadavers, the renal vessels were examined. The first 20 cadavers were examined via TARP approach, and 170 cadavers were investigated after evisceration. The findings were interpreted as they might relate to the TARP approach to the renal pedicle.

RESULTS

The renal artery (RA) originated dorsally or inferiorly to the left renal vein (RV) in 70% of the cadavers on each side. Additional RAs emerging below the inferior mesenteric artery were present in 2.4% of cadavers on the right side and 1.8% on the left. Approach to the inferior vena cava (IVC) adequate for the management of trauma through the TARP approach was impossible, although it has been recommended in some research. The clinically significant incidence of variations was as follows: 47% multiple RAs, 13% multiple RVs, and 50% of at least 1 RA that coursed superior to the right RV on the right margin of the IVC.

CONCLUSION

Knowledge of the varied anatomy of the renal vessels facilitates a safe approach to the kidneys in trauma management. The varied and unpredictable anatomy of the renal vasculature requires prompt change when the TARP approach fails to provide access to the vessels. In such cases, the colon should be mobilized promptly. On the right side of the IVC, the vessels are located so as to require clamping together almost always.

Surgically Relevant Normal and Variant Renal Parenchymal and Vascular Anatomy in Preoperative 16-MDCT Evaluation of Potential Laparoscopic Renal Donors

OBJECTIVE

Using 16-MDCT, we describe and quantify the frequency and types of renal anatomic variants and findings relevant for preoperative evaluation and surgical planning for potential laparoscopic renal donors.

MATERIALS AND METHODS

On 16-MDCT, 126 consecutive potential donors underwent scanning before contrast administration and after i.v. power injection of nonionic contrast material during the arterial, nephrographic, and excretory phases. On a 3D workstation, CT images were evaluated retrospectively in consensus by three abdominal imagers. The number and branching pattern of bilateral renal arteries and veins, including anomalies of the inferior vena cava and lumbar-gonadal axis, were categorized along with the frequency of incidental findings of the renal parenchyma and collecting system.

RESULTS

Major arterial variants including supernumerary and early branching arteries were present in 16% and 21%, respectively, of left kidneys and 22% and 15%, respectively, of right kidneys. Major and minor venous variants were detected in 11% and 58% of left kidneys and 24% and 3% of right kidneys. Late confluence of the venous trunk was identified in 17% of left kidneys and 10% of right kidneys. Incidental parenchymal and urothelial abnormalities, most commonly cysts and calyceal calcifications, were identified in 30% of the kidneys. Other relevant incidental findings included focal infarcts, cortical scars, atrophic scarred kidney, and bilateral papillary necrosis. Urothelial variants included bilateral simple ureteroceles and rightsided complete duplicated collecting system.

CONCLUSION

16-MDCT angiography and urography allow confident detection and classification of a variety of anatomic and incidental anomalies relevant to the preoperative selection of potential laparoscopic renal donors and to surgical planning.

Multidetector row CT angiography of living related renal donors: is there a need for venous phase imaging?

OBJECTIVE

To prospectively evaluate whether renal venous anatomy can be detected from arterial phase images of multidetector row CT (MDCT) of renal donors.

MATERIAL AND METHODS

Institutional review board approved our study protocol with waiver of consent. Forty-eight consecutive renal donors (age range, 21-56 years; M:F, 20:28) referred for MDCT evaluation were included. Two sub-specialty radiologists performed an independent and separate evaluation of renal venous anatomy in arterial and venous phase images. Opacification of renal venous structures was scored on a five-point scale (1-not seen; 3-minimal opacification; 5-excellent opacification). Arterial and venous phase opacification scores were compared by Wilcoxon signed rank test.

RESULTS

Both readers detected all renal venous anomalies in arterial as well as venous phase images. Each reader detected accessory right renal veins (n=14), retroaortic left renal vein (n=2), circumaortic left renal vein (n=1), and left renal hilar arteriovenous malformation (n=1) in arterial phase images. Retroaortic left renal venous branch was difficult to differentiate from lumbar vein (reader-1, n=1; reader-2, n=2) in both arterial and venous phase images. Sensitivity of detection of renal veins, left adrenal, gonadal and lumbar veins in arterial phase images was 100, 83-88, 100, and 85-90%, respectively. As expected, venous phase images showed significantly greater opacification of renal veins, left gonadal, adrenal and lumbar veins (p<.05). However, this did not substantially limit the evaluation of renal venous anatomy in arterial phase images. Both readers had substantial interobserver agreement (kappa coefficient, 0.7; p<0.05).

CONCLUSIONS

Arterial phase MDCT images alone can be used to detect renal venous anomalies, and to identify small left renal venous branches namely, the left gonadal, adrenal and lumbar veins in renal donors. Venous phase MDCT acquisition is not necessary for evaluation of renal venous anatomy in renal donors.