Improved Detection of Renal Vascular Anatomy Using Multidetector CT Angiography: Is 100% Detection Possible?

Supernumerary kidneys: a clinical and radiological analysis of nine cases

Background

A supernumerary kidney (SK) is an additional kidney with its own capsule and blood supply that is not fused with the ipsilateral kidney (IK). Because individual case reports indicate a high morbidity rate, the aim of this retrospective study was a detailed analysis of this rare anatomical variant.

Methods

Our systematic imaging-based search for SKs, conducted in the period from 2000 and to 2017, yielded 9 cases in total (5 men, 4 women; mean age: 51.8 ± 22.8 years).

Results

The SKs were observed on the right in six and on the left side in three cases. In six subjects (66%) they were located caudal and in three cases (33%) cranial to the ipsilateral kidney. Calculi were found in three (33%) of the renal collecting systems. Five (56%) of the SKs had hydronephrosis grade IV and one SK had recurrent pyelonephritis (11%). Two of the ureters opened into the ipsilateral seminal vesicle (22%). Two (22%) SKs were functional but atrophic. Clinically relevant findings were made in 33% of the IKs: atrophy (n = 2), calculi (n = 1), and reflux with recurrent pyelonephritis (n = 1); another 33% had anatomical anomalies without functional impairment. The correct diagnosis of a SK is possible using CT imaging in all subjects. The prevalence of SK based on CT imaging can be estimated to be 1:26750.

Conclusions

CT is the method of choice for visualizing SKs. The correct diagnosis is crucial in preventing dispensable surgical procedures and for providing optimal patient treatment and outcome.

Laparoscopic heminephrectomy in horseshoe kidneys: A single center experience

Introduction

Laparoscopic approach in horseshoe kidney (HSK) is a challenge because of the aberrant vessels, the renal isthmus and the renal ectopia are all unique features of this anomaly encountered during the surgery. We report our single center experience with this technique in managing three patients with HSK.

Methods

A total of 15 cases (9 males and 6 females) were operated between June 2011 and December 2016 for various indications. Of these four patients were managed laparoscopically, two patients with HSK had non-functioning renal moiety underwent transperitoneal heminephrectomy. The third patient with a mass in right moiety with thin fibrous isthmus was successfully managed with laparoscopic heminephrectomy. Fourth patient with pelvi-ureteric junction obstruction with multiple renal calculi was managed with pyeloplasty and complete clearance of all calyceal the stones.

Result

Mean operating time was 140 ± 1.8 (100-180) min, and estimated blood loss was 131 ± 12.6 (30-320) ml. The mean hospital stay was 2.3 ± 1.4 (1-5) days. There were no major intra- and post-operative complications except minimal postoperative discomfort.

Conclusion

Laparoscopic nephrectomy is technically feasible, safe, and reliable for benign and malignant diseases in a HK with mainly three factors posing challenges during the surgery are the abnormal vasculature, division of the isthmus, and lower location of the kidney.

Simultaneous CT angiography and whole-body CT is an effective imaging approach before multiorgan retrieval

PURPOSE

To assess the role of whole-body computed tomography (CT) for determining morphological suitability before multiorgan retrieval (MOR) in brain dead patients.

MATERIALS AND METHODS

Fifty-one clinically brain dead patients (21 women, 30 men; mean age 61 year±15) were included in this prospective, single center study. All patients had CT angiography of the brain and whole-body CT examination. CT images were evaluated for the presence of morphological abnormalities of lungs, liver and other abdominal organs and presence of vascular anatomical variants. The results of CT examinations were compared to intraoperative findings observed during organ harvesting and/or the results of histopathological analysis of biopsy specimens. The impact of whole-body CT examination on the harvesting process was evaluated.

RESULTS

Ninety-five percent of vascular anatomical variants that were found intraoperatively were depicted on CT. CT density measurements predicted surgical finding of steatosis in 80% of patients. Whole-body CT changed the MOR strategy in 21/51 patients (41%) including 3 MOR cancellations and 8 grafts refusals, whereas organ harvesting was continued in 10 patients after histopathological analysis was performed.

CONCLUSION

Selection of potential graft donors using whole-body CT is reliable and improves graft selection during MOR.

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.

Laparoscopic radical nephrectomy under near real-time three-dimensional surgical navigation with C-arm cone beam computed tomography

OBJECTIVE

The aim of this study was to demonstrate the advantages of C-arm cone beam computed tomography for imaging guidance of laparoscopic radical nephrectomy (LRN).

METHODS

Four patients referred to the authors' institution for LRN were included in this study. To visualize the renal vascular anatomy, the Iopamiron 300 contrast agent was injected intravenously. The surgeon could adjust the viewing angle of the images and rotate the reconstructed three-dimensional (3D) image manually by using a mouse-like controller. Using the near real-time 3D navigation images, the surgeon was able to recognize the renal vascular anatomy, and more easily perform the LRN.

RESULTS

All procedures were successfully performed with a satisfactory diagnostic yield or therapeutic effect without procedure-related complications.

CONCLUSION

This novel technology has great potential for application in LRN because it enables accurate depiction of the renal vessels and increases surgeon confidence.

Prospective Evaluation of the Accuracy of MDCT Angiography for Living Kidney Donor

PURPOSE

In donor nephrectomy, it is important to understand the exact anatomy of the blood vessels during minimally invasive surgery. We prospectively analyzed the accuracy of the vessel structures obtained by use of 64-row multi-detector computed tomography (MDCT) angiography compared with the actual vessel structure observed during surgery.

MATERIALS AND METHODS

We analyzed 238 patients who underwent donor nephrectomy from July 2007 to August 2010. Before the operation, MDCT angiography was performed, and after the operation, the surgeons themselves wrote the protocol. The ipsilateral artery, the number of veins, the association with the run of the hilar vessel, and other vascular anomalies in computed tomography (CT) angiography and in the donor protocol were summarized.

RESULTS

Among 238 patients, nephrectomy was performed on the left side in 199 patients. The accuracy of MDCT for the artery and the vein was 93.3% and 92.4%, respectively. Accuracy did not differ significantly on the left and right sides (artery: p=0.124; vein: p=0.174). In 199 patients, the CT findings for the lumbar vein were compared with the surgical findings. The overall accuracy was shown to be 84.9%, and the accuracy of the group drained to the inferior vena cava (54%) was significantly different (p<0.01) from that of the group drained to the renal vein (98.6%). Thus, it may be necessary to pay close attention to the interpretation of the findings for the lumbar vein.

CONCLUSIONS

MDCT angiography is important for understanding the exact anatomy of blood vessels before minimally invasive surgery. We showed that 64-channel MDCT has high accuracy in the main vessel and hilar vessels. However, close attention to the interpretation of the CT findings for the lumbar vein may be required.

Multidetector computed tomography with triple-bolus contrast medium administration protocol for preoperative anatomical and functional assessment of potential living renal donors

OBJECTIVE

To evaluate multidetector computed tomography (MDCT) with a triple-bolus contrast administration protocol for preoperative anatomical and functional assessment of living renal donors.

METHODS

Fifty-five potential living renal donors underwent MDCT of which 27 proceeded to donor nephrectomy. A triple-bolus contrast administration protocol was used for simultaneous acquisition of arterial, nephrographic, and excretory phases. MDCT images were independently reviewed in random order by two radiologists blinded to surgical anatomy findings. Diagnostic accuracy for anatomical variants was quantified by sensitivity and specificity. Differential renal function (DRF) was derived from MDCT for 54 patients and compared with technetium-99 m dimercaptosuccinic acid renography (Tc-99 m DMSA).

RESULTS

All triple-bolus MDCT examinations were technically adequate. Accessory renal arteries and veins were identified at surgery in 33% (n = 9/27) and 22% (n = 6/27) of donor kidneys. The mean difference between MDCT-derived DRF and DMSA was 0.8% (95% CI 0.1-1.6) with 95% limits of agreement of -4.6% (95% CI -3.3 to -5.9) to 6.3% (95% CI 5.0-7.6). MDCT delivered a mean (SD, range) radiation dose of 9.5 (3.6, 3.6-17.3) mSv.

CONCLUSION

MDCT with a triple-bolus contrast administration provides accurate anatomical and functional evaluation of living renal donors.

Development of laparoscopic donor nephrectomy: a strategy to increase living kidney donation incentive and maintain equivalent donor/recipient outcome

BACKGROUND/PURPOSE

Laparoscopic donor nephrectomy (LDN) has emerged as the preferred technique worldwide, and has contributed to a dramatic increase in living kidney donation during the past decade. We adopted LDN in 2002 with the intention of increasing living kidney donation incentive and maintaining equivalent donor/recipient outcome.

METHODS

Forty-five LDNs were performed between September 2002 and November 2007. Donor demographics, operative characteristics, perioperative complications and donor/recipient outcome were reviewed retrospectively. The LDN series was divided into earlier and later groups for comparison. To confirm the safety and efficacy of LDN, we compared the results with those of previous series and our open donor nephrectomy (ODN) series.

RESULTS

All 45 LDN kidneys were procured and transplanted successfully. Mean donor operation time was 327.7+/-10.2 minutes, blood loss was 286.0+/-48.3 mL, and warm ischemia time was 233.9+/-19.6 seconds. Two (4.4%) open conversions happened in the earlier group. There was a significant decrease in warm ischemia time and donor intraoperative complications in the later group. There was no donor mortality and there were no repeat surgical procedures. Delayed graft function occurred in 8.9% of cases and three (6.7%) recipients developed ureteral complications. All but one recipient was discharged with adequate renal function. Graft function continued in 41 of the 43 harvested kidneys (95.3%). Compared with ODN, there was a significant decrease in donor postoperative stay in the LDN series (p=0.00). There was no difference between the series with regard to donor safety, donor outcome, and immediate and long-term recipient outcome.

CONCLUSION

The number of living kidney donations increased significantly after adopting LDN in our series. The equivalent donor/recipient outcome of the LDN series compared with that of previous and ODN series was achieved with increasing experience.

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.

Laparoscopic donor nephrectomy

Since it first was performed in 1995, laparoscopic donor nephrectomy (LDN) has grown to be the standard of care in most transplant centers in the United States. This article reviews the current indications, selection criteria, surgical approaches, outcomes, and complications of LDN.

Celiac axis and superior mesenteric artery: danger zone for left nephrectomy

We report two cases of iatrogenic occlusion of the superior mesenteric artery (SMA) and celiac axis (CA) during left nephrectomy. A patient with a urothelial carcinoma (open surgery) and one with coralliform calculi (laparoscopy) experienced injury to both the SMA and/or CA due to bulky perihilar adenopathy and kidney adherence to surrounding tissue. The cancer patient survived after fast repair. Repair was delayed in the second patient who subsequently died. It is essential to identify each arterial branch carefully on the preoperative CT-scan to identify any duplicate renal arteries and avoid mistaking the SMA and/or CA for the renal artery.

Kidney fusion anomalies revisited: clinical and radiological analysis of 209 cases of crossed fused ectopia and horseshoe kidney

OBJECTIVE

To analyse the morphological appearance of horseshoe kidneys (HKs) and crossed fused ectopia (CFE) and to assess the frequency and clinical significance of associated anomalies and diseases.

PATIENTS AND METHODS

The findings and images of 209 patients with fused kidneys (FKs) were reviewed; in all, 244 scans from computed tomography (CT), 233 ultrasonograms and 89 micturition cysto-urethrograms, urograms, magnetic resonance images and angiograms were taken.

RESULTS

HKs (found in one of 474 abdominal CT scans) and CFEs (found in one of 3078 CT scans) showed a high variability of vasculature that could not be classified. However, some generalized conclusions were possible about the renal vasculature (430 arteries in 103 kidneys). Variants of the most cephalad artery of both sides were rare. The second artery on the right had a pre-caval course. The origins of vessels located further caudal were more ventral. CFEs were anatomically different from HKs with respect to lower position, greater axial rotation, smaller pelvic width, more caudal origin, and fewer vessels, but not in accompanying anomalies. Severe anomalies or malformations were found in 23% of patients, with half of them in the urogenital system. Malformations were found considerably more often in children than in adults. There was no increased incidence of diseases such as stones or inflammation of the renal pelvis.

CONCLUSION

Concomitant anomalies and diseases were equally frequent for HK and CFE, but less frequent than generally assumed. Individual cases of complex anatomical situations require special examination strategies, and CT appears to be the most reliable imaging method.

Assessment of aortic pathology and peripheral arterial disease using multidetector computed tomographic angiography

The development of multidetector computed tomography represents a remarkable diagnostic advancement because this imaging modality has been widely used in the evaluation of the cardiovascular system. With scanner-adjusted image acquisition and contrast medium administration, multidetector computed tomographic angiography provides a cost-effective and accurate imaging assessment in patients with aortic pathologies or peripheral arterial occlusive disease. Multidetector computed tomographic angiography is associated with several advantages, including high image spatial resolution and rapid imaging acquisition speed. This diagnostic methodology allows accurate detection of a variety of intravascular lesions in the carotid artery, thoracic and abdominal aorta, renal arteries, and peripheral arterial systems. This article provides an overview of multidetector computed tomographic angiography in the assessment of arterial disease and reviews current literature about this diagnostic technology in the evaluation of aortic and peripheral arterial pathologies.

Do mechanical fluid laws dictate the branching pattern of the renal artery?

INTRODUCTION

Anatomy of the renal artery is an important issue in the renal transplantation era. Multi-detector computed tomography angiography (MDCTA) is an accurate modality for the preoperative assessment of live renal donors, and it provides excellent details of donor arterial anatomy. We studied the relationship between the angle of emergence of the renal artery from the aorta and its branching pattern.

METHODS

In this study, the MDCTA images obtained from the 138 kidneys of 77 potential renal transplant donors were studied. The courses of the right and left renal arteries from the aorta to the kidney hilus were delineated. The branching angle of the renal artery from the aorta (beta, angle) and the length of the renal artery from the aorta until its first division were measured (Delta, distance). The renal artery deviation from the perpendicular plane of the aorta (D, factor of deviation) was calculated by the following formula: D = (1 - sin [beta]). The cosine of this angle (cos [beta]) was also calculated. Statistical analyses were performed with Pearson correlation tests. The P value was set at .05.

RESULTS

The mean age of patients was 28.7 +/- 4.3 with a male to female ratio of 63:14. The mean Delta distance and small de, Cyrillic diameter were 34.37 +/- 10.68 mm (range, 10-58) and 6.13 +/- 1.37 mm (range, 2.8-9.9), respectively. The mean beta angle, factor of deviation, and cos (beta) were 62.19 degrees +/- 16.44, 0.15 +/- 0.14, and 0.45 +/- 0.25, respectively. Significant negative correlations were found between the beta angle, and Delta distance (r = -0.308; P < .001), and small de, Cyrillic diameter (r = -0.303; P = .003). Factor of deviation and cos (beta) were directly associated Delta distance and small de, Cyrillic diameter.

CONCLUSION

These findings indicated that with the main renal artery axis deviating from the perpendicular plane of the aorta or with a smaller branching angle, this artery had a greater diameter and underwent late branching. This study suggested that the renal artery diameter and branching pattern might be determined by the mechanical fluid laws.

Multidetector computed tomographic angiography of the cardiovascular system

The introduction of multidetector computed tomography (MDCT) is considered a dramatic development in CT imaging that has direct implication in the imaging of various systems, in particular the cardiovascular system. The advantages of MDCT are an enormous increase in imaging acquisition speed, more coverage of the patient, and high spatial resolution. This article reviews the recent developments in CT angiography and discusses the clinical application relevant to diagnosis and endovascular treatment of cardiovascular diseases.