Helical computerized tomography arteriography for evaluation of live renal donors undergoing laparoscopic nephrectomy

Successful Use of Ectopic Pelvic Kidney for Living Related Donation Technical Aspects and Literature Review

Ectopic pelvic kidneys can provide an additional source of organs for transplantation. They are often excluded from donation in living donation programs mainly due to aberrant vascular and urinary anatomies. We present a donor with an ectopic left kidney, who successfully donated his kidney. The use of ectopic pelvic kidney for living kidney transplantation is a highly demanding surgical procedure but after extensive preoperative investigation in high volume centers with surgical expertise in vascular reconstruction and access surgery, ectopic pelvic kidneys should not be a contraindication for donation and should be considered as a viable option.

Does size matter? Kidney transplant donor size determines kidney function among living donors

BACKGROUND

Kidney donor outcomes are gaining attention, particularly as donor eligibility criteria continue to expand. Kidney size, a useful predictor of recipient kidney function, also likely correlates with donor outcomes. Although donor evaluation includes donor kidney size measurements, the association between kidney size and outcomes are poorly defined.

METHODS

We examined the relationship between kidney size (body surface area-adjusted total volume, cortical volume and length) and renal outcomes (post-operative recovery and longer-term kidney function) among 85 kidney donors using general linear models and time-to-chronic kidney disease data.

RESULTS

Donors with the largest adjusted cortical volume were more likely to achieve an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 over a median 24-month follow-up than those with smaller cortical volumes (P <0.001), had a shorter duration of renal recovery (1.3-2.2 versus 32.5 days) and started with a higher eGFR at pre-donation (107-110 versus 91 mL/min/1.73 m2) and immediately post-nephrectomy (∼63 versus 50-51 mL/min/1.73 m2). Similar findings were seen with adjusted total volume and length.

CONCLUSIONS

Larger kidney donors were more likely to achieve an eGFR ≥60 mL/min/1.73 m2 with renal recovery over a shorter duration due to higher pre-donation and initial post-nephrectomy eGFRs.

Vascular Multiplicity Should Not Be a Contra-Indication for Live Kidney Donation and Transplantation

BACKGROUND

Whether vascular multiplicity should be considered as contraindication and therefore 'extended donor criterion' is still under debate.

METHODS

Data from all live kidney donors from 2006-2013 (n = 951) was retrospectively reviewed. Vascular anatomy as imaged by MRA, CTA or other modalities was compared with intraoperative findings. Furthermore, the influence of vascular multiplicity on outcome of donors and recipients was studied.

RESULTS

In 237 out of 951 donors (25%), vascular multiplicity was present. CTA had the highest accuracy levels regarding vascular anatomy assessment. Regarding outcome of donors with vascular multiplicity, warm ischemia time (WIT) and skin-to-skin time were significantly longer if arterial multiplicity (AM) was present (5.1 vs. 4.0 mins and 202 vs. 178 mins). Skin-to-skin time was significantly longer, and complication rates were higher in donors with venous multiplicity (203 vs. 180 mins and 17.2% vs. 8.4%). Outcome of renal transplant recipients showed a significantly increased WIT (30 vs. 26.7 minutes), higher rate of DGF (13.9% vs. 6.9%) and lower rate of BPAR (6.9% vs. 13.9%) in patients receiving a kidney with AM compared to kidneys with singular anatomy.

CONCLUSIONS

We conclude that vascular multiplicity should not be a contra-indication, since it has little impact on clinical outcome in the donor as well as in renal transplant recipients.

Aneurysmectomy with partial nephrectomy on a living donor renal allograft: a case report

Vascular anomalies among living kidney donors are seldom encountered and their presence offers a complex opportunity for every transplant surgeon. Furthermore, there has been an increasing trend with the use of marginal or kidneys with pathology to address the shortage of organs. We report a rare case of a kidney allograft with a saccular aneurysm and renal cortical cysts for which an excision with primary repair and partial nephrectomy were done, respectively. The recipient was a 45-year-old female with lupus nephritis and significant comorbidities who had excellent recovery and outcome. With good surgical techniques, these types of grafts continue to provide acceptable outcome but safety of the donor should be of utmost importance.

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.

Maximizing the donor pool: use of right kidneys and kidneys with multiple arteries for live donor transplantation

BACKGROUND

Studies have shown donor and recipient outcomes to be equivalent for laparoscopic donor nephrectomy (LDN) and open donor nephrectomy. In the past, LDN has been avoided in the procurement of the right kidney or organs with multiple arteries. This study compares procurement of right and left kidneys as well as procurement of single- and multiple artery organs.

METHODS

A review of all LDNs at a single institution between August 2000 and December 2007 was performed. The data included estimated blood loss (EBL), need for transfusion, operative time, warm ischemia time, length of hospital stay (LOS), and delayed graft function. Arterial supply was assessed using renal arteriogram or computed tomographic (CT) angiography. Outcomes for multiple versus single artery and left versus right LDN were compared. Student's t-test and chi-square test were used for statistical comparison.

RESULTS

A total of 230 LDNs were performed. Multiple arteries were present in 37 donors. The right kidney was procured from 36 donors. No significant difference in EBL, transfusions, operative time, or LOS was noted between multiple and single or right and left LDNs. Warm ischemia time was significantly longer for multiple arteries (mean, 83 s) than for single arteries (mean, 63 s; p = 0.007), and for right kidneys (mean, 86 s) than for left kidneys (mean, 62 s; p = 0.001). No significant difference in delayed graft function was seen in the comparison of multiple (21.6%) and single (11.4%) artery organs (p = 0.11) or of right (13.9%) and left (12.9%) kidneys (p = 0.79).

CONCLUSIONS

The presence of multiple arteries or the need to procure the right kidney does not affect the operative outcome of laparoscopic donor nephrectomy. Warm ischemia time may be greater for these groups, but this does not result in delayed allograft function. The laparoscopic approach should be the standard of care even when expansion of the donor pool includes organs with multiple arteries and procurement of the right kidney.

[Laparoscopic nephrectomy in a living donor]

Kidney transplantation is the therapeutic option of choice for patients with end-stage renal disease. With the advent of safer harvesting techniques and immunosuppression, both donor and recipient outcomes have markedly improved in recent years. Kidney donation from Living donors remains the single most important factor responsible for improving patient and graft survival. The laparoscopic donor nephrectomy has revolutionized renal transplantation, allowing expansion of the donor pool by diminishing surgical morbidity while maintaining equivalent recipient outcome. This technique is now becoming the gold-standard harvesting procedure in transplant centres worldwide, despite its technical challenge and ongoing procedural maturation, especially early in the learning curve. Previous contraindications to laparoscopic donor nephrectomy are no longer absolute. In the following analysis, the procedural aspects of the laparoscopic donor nephrectomy are detailed including pre-operative assessment, operative technique and a review of the current literature delineating aspects of both donor and recipient morbidity and mortality compared with open harvesting techniques.

Semiautomated MIP Images Created Directly on 16-Section Multidetector CT Console for Evaluation of Living Renal Donors

Institutional Review Board approval was obtained and informed consent was waived for this HIPAA-compliant study. The aim of this study was to retrospectively compare the accuracy of semiautomated maximum intensity projection (MIP) images created at a 16-section multidetector CT console with three-dimensional (3D)-workstation-generated images for the definition of renal donor anatomy, with intraoperative findings as a reference standard. In examining 40 renal donors (21 men and 19 women; age range, 24-56 years; mean age, 40.4 years), the sensitivity and accuracy for mapping donor anatomy by two readers were greater than 95%, interobserver agreement was excellent (kappa = 0.89-1.00). The 95% confidence interval for sensitivity was also calculated. Simple MIPs compared well with 3D-workstation images. MIPs from a predesigned protocol on the scanner console were generated more quickly than similar images from 3D workstations; postprocessing demands (eg, for renal donors) can be quickly fulfilled at the scanner console itself. The average time to generate simple MIPs at the console was 3.4 minutes (range, 1.7-4.4 minutes), and 22.3 minutes (range, 15-30 minutes) to create images at the 3D workstation.

Transperitoneal laparoscopic live donor nephrectomy: Current status

Renal transplantation is the treatment of choice for a suitable patient with end stage renal disease. Unfortunately, the supply of donor organs is greatly exceeded by demand. In many countries the use of kidneys from living donors has been widely adopted as a partial solution. Traditionally donor nephrectomy has been performed via a open flank incision however with some morbidity like pain and a loin scar. Currently, the donor nephrectomy is increasingly being performed laparoscopically with the objective of reducing the morbidity. It is also hoped that this will lead to increasing acceptance of living donation. The first minimally invasive living donor nephrectomy was carried out in 1995 at the Johns Hopkins Medical Center and since then many centers have undertaken laparoscopic living donor nephrectomy. The laparoscopic approach substantially reduces the donor morbidity and wound related problems associated with open nephrectomy. The laparoscopic techniques thus have the potential to increase the number of living kidney donors. The present article attempts to review the safety and efficacy of transperitoneal laparoscopic donor nephrectomy.

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

BACKGROUND AND PURPOSE

Multidetector CT angiography (MDCTA) is being used increasingly to evaluate vascular anatomy prior to donor nephrectomy. To improve the ability of MDCTA to predict donor renal anatomy, a novel protocol including four-phase imaging with three-dimensional reconstruction and maximum intensity projections (MIPs) was incorporated into the standard donor evaluation. The purpose of this study was to determine the results of this protocol.

PATIENTS AND METHODS

Seventy consecutive patients who underwent hand-assisted laparoscopic donor nephrectomy between January 2003 and September 2004 were reviewed. All MDCTA studies were examined initially by a radiologist alone, after which, a second preoperative reading was performed by a radiologist and the operating surgeon together. The two reviews were compared with the operative findings.

RESULTS

Using this protocol to detect the total number of renal arteries, veins, and ureters, the sensitivity of the initial radiologist was 97%, 100%, and 96%, respectively. These values increased to 100%, 100%, and 99% when the films were reviewed by a radiologist together with the surgeon who would operate on the donor. The sensitivity, specificity, and accuracy in predicting supernumerary arteries, including early (< or =1-cm) arterial branching was 89%, 100%, and 97%, respectively after the single reading but increased to 100%, 100%, and 100% with the combined reading.

CONCLUSIONS

An MDCTA study with this protocol provides excellent anatomic detail prior to donor nephrectomy. Its ability to predict renal-arterial and ureteral anatomy is enhanced when the films are reviewed simultaneously by a radiologist and the operating surgeon.

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.

Utility of 16-MDCT angiography for comprehensive preoperative vascular evaluation of laparoscopic renal donors

OBJECTIVE

Our objective was to determine the efficacy of 16-MDCT angiography in preoperative evaluation of vascular anatomy of laparoscopic renal donors.

METHODS AND MATERIALS

Fifty-five consecutive renal donors (25 men and 30 women) underwent 16-MDCT angiography followed by donor nephrectomy. In the arterial and nephrographic phases, images were acquired with 60% overlap and 0.6-mm reconstruction in both phases after 120 mL of iohexol was injected at 4 mL/sec. On a 3D workstation, images were evaluated retrospectively by two abdominal imagers blinded to surgical results with respect to number and branching pattern of renal arteries and major and minor renal veins. These CT angiography results were compared with surgical findings.

RESULTS

The surgically confirmed sensitivity of both reviewers (1 and 2) using the MDCT data for detection of renal arteries was 98.5% (65 of 66), and accuracies were 97.0% for reviewer 1 and 95.5% for reviewer 2. Sensitivity and accuracy detection of renal veins was 97% (61 of 63) and 98% (62 of 63) for reviewer 1 and reviewer 2, respectively. Sensitivity and accuracy detection of early arterial bifurcation (< 2 cm from aorta) was 100% (14 of 14), and sensitivity in detection of late venous confluence (< 1.5 cm from aorta) was 100% (8 of 8). All major renal venous variants were identified; reviewer 1 identified 78% (18 of 23) minor venous variants, and reviewer 2 identified 83% (19 of 23) minor venous variants. There were no hemorrhagic complications at surgery. Excellent agreement between reviewers (kappa = 0.92-0.97) was achieved for detection of normal and variant anatomy.

CONCLUSION

16-MDCT angiography enabled excellent preoperative detection of arterial anatomy and venous laparoscopic donor nephrectomy.

[Living donor kidney transplantation: helical CT evaluation of candidates]

OBJECTIVES

Computed tomography (CT) is a diagnostic tool that has won acceptance in the past years for the vascular evaluation of living renal donor (LRD) candidates. We show the findings observed in a series of 102 candidates consecutively evaluated in our centre and present the correlation with the surgical data obtained in those individuals finally operated.

METHODS

From May 1995 to June 2005, 102 LRD candidates were evaluated with CT. Eighteen were also studied with digital subtraction angiography (DSA). Fifty-eight donors underwent nephrectomy. Prevalence of arterial and venous variants found on CT exams were analyzed, as well as the correlation with surgical and DSA data when they were obtained.

RESULTS

Forty-four percent candidates showed multiple renal arteries at least in one kidney. Seventy-one percent of right kidneys and 76% of left kidneys had a single arterial pedicle. Early branching was observed in 7.8% and 15.7% in right and left kidneys respectively. Venous variants were present in 17.5% and the 13.7% in right and left sides respectively. Sensitivity, specificity and accuracy of CT to detect accessory arteries were 89%, 100% and 97% respectively when it was compared to DSA. Correlation with surgical data raised 93% for the presence of arterial variants.

CONCLUSIONS

Vascular variants in renal pedicle showed a high prevalence. Helical CT can effectively achieve all the information required prior to surgery as a sole imaging procedure in LRD candidates.

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.

Magnetic resonance renal angiography and venography: an analysis of 111 consecutive scans before donor nephrectomy

OBJECTIVE

To determine the accuracy of magnetic resonance imaging (MRI) renal angiography in predicting vascular anatomy before donor nephrectomy, to determine the significance of missed vessels and to ascertain whether vessels are missed because of technical limitations or errors in interpretation.

PATIENTS AND METHODS

In all, 111 consecutive living donations were assessed; the anatomy on MRI before donation was compared with that at nephrectomy. The significance of additional arteries and veins was recorded at the time of donation, with extra vessels either anastomosed or sacrificed. Finally, the scans in which extra vessels had not been identified were re-examined to establish whether these could be identified retrospectively.

RESULTS

In all, 93 kidneys had a single renal artery and 18 had two. All lower pole arteries were anastomosed and all upper pole arteries were sacrificed. Nine arteries were identified before surgery (five were to the lower pole), and nine were missed (four to the lower pole). There were 13 kidneys with more than one vein. Four of these were seen on MRI. However, an extra vein was anastomosed in only one case. On review of the imaging, three arteries were missed because of human error and six due to technical limitations. Of the nine missed veins, only three were easily identified retrospectively. Overall, using MRI as a preoperative investigation for the 111 consecutive cases, the surgeon encountered a previously unidentified accessory artery in nine (8%), and this required anastomosis in four (4%).

CONCLUSION

MR angiography has the advantage over computed tomography (CT) of having virtually no side-effects, and if the small possibility is accepted of missing extra vessels because of technical limitation or interpretation, it is a good investigation. However, in light of the failure to visualize all arteries transplanted, we have started to use multi-slice (16-channel) CT to see if its improved spatial resolution alters the results.

MDCT angiography of living laparoscopic renal donors

Laparoscopic donor nephrectomy has become the accepted method of harvesting the kidney at many institutions because of multiple advantages over open donor nephrectomy. Spiral computed tomographic (CT) angiography provides accurate information of renal vascular anatomy and has become an accepted method of preoperative evaluation of potential laparoscopic renal donors. More recently, multidetector CT (MDCT) provides more detailed datasets compared with single-detector spiral CT and has been used for preoperative evaluation of laparoscopic donor nephrectomy to provide accurate anatomic information. MDCT (especially 16- and 64-slice MDCT) angiography has advantages over single-detector helical CT due to rapid scan time that allows coverage of a large volume of interest with higher spatial and temporal resolutions. In this article, we review the current status of MDCT angiography in the evaluation of laparoscopic renal donors and potential advantages of using this technology.

Kidney displacement simulator for retroperitoneal laparoscopic nephrectomy

PURPOSE

We evaluated the efficacy of a renal displacement simulator originally developed at our department for retroperitoneal laparoscopic nephrectomy.

MATERIALS AND METHODS

A total of 12 patients with a malignant localized renal (7) or ureteral (5) neoplasm underwent multidetector row computerized tomography. Imaging data were sent to a dedicated work station to create volume rendering and virtual laparoscopic images of the kidney, which was displaced ventral using a retroperitoneal balloon. These findings were compared with video images obtained during laparoscopy surgery.

RESULTS

The kidney displacement simulator depicted all renal arteries (100% sensitivity) and 13 of 14 renal veins (93% sensitivity). Hilar anatomy, including the tumor, as well as major vessels and their relationships were visualized by the simulator in the laparoscopic views. The major vessel portions completely corresponded to those seen during surgery, and the left adrenal and gonadal veins were also synchronized quite well.

CONCLUSIONS

Our kidney displacement simulator was able to visualize the major vessel portions and branched small vessels, such as the adrenal and gonadal veins, prior to surgery. It is considered useful for providing guidance to surgeons and decreasing operative risks and possible complications.

Prospective study comparing three-dimensional computed tomography and magnetic resonance imaging for evaluating the renal vascular anatomy in potential living renal donors

OBJECTIVE

To prospectively compare the accuracy of multislice spiral computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) in evaluating the renal vascular anatomy in potential living renal donors.

SUBJECTS AND METHODS

Thirty-one donors underwent multislice spiral CTA and gadolinium-enhanced MRA. In addition to axial images, multiplanar reconstruction and maximum intensity projections were used to display the renal vascular anatomy. Twenty-four donors had a left laparoscopic donor nephrectomy (LDN), whereas seven had right open donor nephrectomy (ODN); LDN was only considered if the renal vascular anatomy was favourable on the left. CTA and MRA images were analysed by two radiologists independently. The radiological and surgical findings were correlated after the surgery.

RESULTS

CTA showed 33 arteries and 32 veins (100% sensitivity) whereas MRA showed 32 arteries and 31 veins (97% sensitivity). CTA detected all five accessory renal arteries whereas MRA only detected one. CTA also identified all three accessory renal veins whereas MRA identified two. CTA had a sensitivity of 97% and 47% for left lumbar and left gonadal veins, whereas MRA had a sensitivity of 74% and 46%, respectively.

CONCLUSION

Multislice spiral CTA with three-dimensional reconstruction was more accurate than MRA for both renal arterial and venous anatomy.

Laparoscopic donor nephrectomy

Of the various options for patients with end stage renal disease, kidney transplantation is the treatment of choice for a suitable patient. The kidney for transplantation is retrieved from either a cadaver or a live donor. Living donor nephrectomy has been developed as a method to address the shortfall in cadaveric kidneys available for transplantation. Laparoscopic living donor nephrectomy (LLDN), by reducing postoperative pain, shortening convalescence, and improving the cosmetic outcome of the donor nephrectomy, has shown the potential to increase the number of living kidney donations further by removing some of the disincentives inherent to donation itself. The technique of LLDN has undergone evolution at different transplant centers and many modifications have been done to improve donor safety and recipient outcome. Virtually all donors eligible for an open surgical procedure may also undergo the laparoscopic operation. Various earlier contraindications to LDN, such as right donor kidney, multiple vessels, anomalous vasculature and obesity have been overcome with increasing experience. Laparoscopic live donor nephrectomy can be done transperitoneally or retroperitoneally on either side. The approach is most commonly transperitoneal, which allows adequate working space and easy dissection. A review of literature and our experience with regards to standard approach and the modifications is presented including a cost saving model for the developing countries. An assessment has been made, of the impact of LDN on the outcome of donor and the recipient.

Preoperative evaluation of live renal donors using multislice CT angiography

AIM

To determine the accuracy of multidetector row CT renal angiography in the preoperative evaluation of live kidney donors, and to identify potential pitfalls when reporting.

METHODS

Between July 1998 and June 2003, 74 consecutive live renal donors underwent contrast-enhanced multidetector row CT renal angiography before donor nephrectomy. The operative notes and radiological reports of all cases were reviewed retrospectively. Where a significant discrepancy was identified, the archived images were reviewed by two radiologists in the light of the intraoperative findings.

RESULTS

A total of 12 discrepancies were identified in 11 of the 74 cases (15%). In the preoperative CT angiography reports, 4 accessory arteries, 6 early-branching renal arteries, 1 duplicated renal vein and 1 accessory ureter were not identified; 9 of these were evident on review, but were not detected at the time of reporting. In 3 cases (1 accessory artery, the duplicated renal vein and the accessory ureter), the anomaly was not visible on review of the CT angiographic data, even with the benefit of hindsight. Surgical feedback during the study period resulted in modifications to CT technique and improved performance.

CONCLUSION

In the majority of cases, there was good correlation between preoperative CT renal angiography and operative findings. Most discrepancies were due either to an oversight by the reporting radiologist, or failure to fully appreciate the potential surgical significance of certain findings. Regular surgical feedback plays a valuable role in improving reporting accuracy and maintaining imaging standards.

Correlation of preoperative three-dimensional magnetic resonance angiography with intraoperative findings in laparoscopic renal surgery

BACKGROUND AND PURPOSE

Contrast-enhanced three-dimensional magnetic resonance angiography (3D-MRA) with image reconstruction has important applications in laparoscopic urologic surgery. We now use 3D-MRA as part of our preoperative evaluation in selected patients undergoing laparoscopic donor nephrectomy, pyeloplasty, radical nephrectomy, and partial nephrectomy.

PATIENTS AND METHODS

From June 2001 to December 2002, 50 patients underwent preoperative 3D-MRA at 1.5 T prior to laparoscopic renal surgery. In general, preoperative 3D-MRA was obtained for donor nephrectomies and pyeloplasties and for cases where prior imaging suggested a possible vascular anomaly. Patients who underwent preoperative imaging included those having donor nephrectomy (N = 28), pyeloplasty (N = 12), radical nephrectomy (N = 5), partial nephrectomy (N = 3), and other laparoscopic renal procedures (N = 2). The 3D-MRA studies were interpreted by one radiologist, and all laparoscopic cases were performed by one of two surgeons. The findings of 3D-MRA were correlated with the intraoperative findings with special attention to aberrant vasculature, including duplicated renal arteries or veins, accessory vessels, or crossing vessels.

RESULTS

Among patients undergoing laparoscopic donor nephrectomy, 3D-MRA correctly predicted the number of renal vessels in 27 of 28 cases (96%), including all 3 cases of left retroaortic renal vein. Also, 3DMRA correctly predicted the presence or absence of a crossing vessel in 10 of 12 cases (83%) of laparoscopic pyeloplasty. The imaging study also correctly predicted the number of hilar vessels in all five cases of radical nephrectomy, all three cases of partial nephrectomy, and both cases of other renal operations. Overall, 3D-MRA correctly defined the renal hilar anatomy in 48 of 50 patients, for an overall accuracy of 96%.

CONCLUSIONS

Three-dimensional MRA findings correlate well (96%) with intraoperative findings in laparoscopic renal surgery. The imaging study provides exquisite vascular detail and is highly accurate, making it sufficient imaging prior to laparoscopic donor nephrectomy and useful for pyeloplasty and other complex renal operations.

Multi-detector row CT in evaluation of 94 living renal donors by readers with varied experience

PURPOSE

To retrospectively assess the accuracy of four-section multi-detector row computed tomography (CT) in the evaluation of renal transplant donors when scans are read by one of multiple readers with varied levels of expertise, by using surgery as the reference standard.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board and complied with the Health Insurance Portability and Accountability Act. Informed consent was waived. Between October 1999 and March 2003, 94 renal donors (42 men, 52 women; mean age, 44 years) underwent four-section multi-detector row CT. Unenhanced scanning of the abdomen was performed with 5-mm section thickness and table speed of 15 mm per rotation. Next, 135-150 mL of nonionic iodinated (300 mg/mL) contrast material was injected intravenously at a rate of 4-5 mL/sec. Contrast material-enhanced CT was initiated 20-25 seconds, 65-70 seconds, and 10 minutes after start of injection. Arterial phase scanning was performed with 1.25-mm section thickness and 7.5-mm table speed. Venous and excretory phase scanning was performed with 2.5-mm section thickness and 15-mm table speed. Each scan was evaluated independently by one of 11 readers for renal vascular and ureteral anatomic variants. Findings at CT were compared with those at surgery. Sensitivity and specificity (with 95% confidence intervals) and accuracy of CT were calculated on the basis of presence or absence of variant anatomy at surgery.

RESULTS

CT depicted 107 of 114 renal arteries confirmed at surgery; seven accessory arteries were missed in six donor kidneys. CT depicted 95 of 98 renal veins confirmed at surgery. Sensitivity and specificity of CT were 66% and 100%, 75% and 100%, and 50% and 100%, and overall accuracy was 94%, 97%, and 99%, for identification of variant anatomy of renal arteries, veins, and ureters, respectively.

CONCLUSION

Multi-detector row CT as the sole imaging technique in the preoperative evaluation of living renal donors is accurate even when images are read by multiple readers with varied levels of expertise.

Three-dimensional CT angiography imaging of vascular tumors of the head and neck

OBJECTIVE

To evaluate the utility of three-dimensional (3D) computerized tomography angiography (CTA) in head and neck vascular anomalies.

DESIGN

Prospective case series.

METHODS

A consecutive series of cases of patients with distinct types of vascular anomalies (i.e. hemangioma, arteriovenous malformation, venous malformation and lymphatic malformation) were obtained through CT multislice scanner and analyzed with Vitrea 2 software (Vital Images Inc., Plymouth, MN).

RESULTS

CTA was safe and successful in describing 3D vascular anatomy of a variety of vascular lesions.

CONCLUSIONS

Three-dimensional CTA allows detailed description of vascular lesions of the head and neck and offers another effective means of imaging these complex lesions.

Evaluation of the Renal Venous System on Late Arterial and Venous Phase Images with MDCT Angiography in Potential Living Laparoscopic Renal Donors

OBJECTIVE

The objective of our study was to assess whether both renal arteries and renal veins can be evaluated using single-phase MDCT data sets alone to eliminate the need for both arterial and venous phase data sets.

MATERIALS AND METHODS

One hundred consecutive potential living renal donors who underwent 4-MDCT were evaluated. CT was performed with 120 mL of IV contrast material at an injection rate of 3 mL/sec. Both late arterial and venous phase acquisitions were obtained at 25 and 55 sec from the start of IV contrast injection, respectively. The number of the right and left renal veins and its anatomic variations were assessed by two reviewers. Late arterial phase images were evaluated initially, and then venous phase images were analyzed to assess opacification of the renal vein and to see whether venous phase data sets changed or added information about the venous anatomy as seen on late arterial phase images.

RESULTS

The retroaortic left renal vein was found in two subjects, and the circumaortic left renal vein was detected in three subjects. The renal veins were adequately opacified on late arterial phase images in all subjects. There were six subjects who had a normal left renal vein with a small posterior branch coursing posterior to the aorta and draining into the inferior vena cava, which were difficult to differentiate from the lumbar vein or ascending lumbar vein; in three of these six subjects, the small posterior branch was opacified only on venous phase images.

CONCLUSION

Late arterial phase images obtained at 25 sec after the start of contrast injection can reveal the renal vein anatomy except for a small posterior branch of the left renal vein difficult to differentiate from the lumbar or ascending lumbar vein, as seen in three subjects. The data suggest that venous phase imaging is not necessary for the evaluation of renal vein anatomy.

Adult Ureteropelvic Junction Obstruction: Insights with Three-dimensional Multi–Detector Row CT

Ureteropelvic junction obstruction (UPJO) is a benign, congenital condition that remains an enigma in terms of both diagnosis and therapy. On the basis of a series of cases that were referred to the authors in their clinical practice, they found that the unprecedented quality and novel perspectives of multi-detector row computed tomography (CT) with two- and three-dimensional postprocessing allow a comprehensive, single-study assessment of the ureterovascular relationships in UPJO. This topic is important because the causative role of crossing vessels may be questioned on the basis of such studies, and the therapeutic approach may be altered by using precise anatomic images customized to the pathologic features of the individual patient. Although CT images can provide only circumstantial or supportive evidence of the pathophysiology of UPJO, they greatly facilitate therapeutic intervention when it is clinically indicated and may eliminate the need for it in select cases. Careful attention to the postprocessing of CT images may show that the crossing vasculature has no direct relationship to the transition point of the UPJO in many cases.

A prospective study of the predictive power of spiral computed tomographic angiography for defining renal vascular anatomy before live-donor nephrectomy

OBJECTIVE

To determine the accuracy of spiral computed tomography (CT) imaging of donor venous anatomy by comparing CT angiography (CTA) and operative findings, for both laparoscopic (LDN) and open donor nephrectomy.

PATIENTS AND METHODS

LDN presents unique surgical challenges, particularly with complex venous or arterial anatomy. The limitations of surgical access, poor visibility of the superior and posterior borders of the renal vein during LDN, and the variability of venous anatomy in this region, contribute to the difficulty of LDN, underlining the importance of imaging beforehand. Forty live donors (mean age 46 years, sd 11; 65% female) were assessed by CTA before donation. Scans were reported by the same radiologist. The number and diameter of 'predicted' renal arteries, veins and renal vein tributaries were documented. The donor kidney was removed by two consultant surgeons, and after back-table perfusion the same details were recorded and taken as the 'reference' findings. Tributaries of <1 mm diameter were not recorded. The right kidney was retrieved in seven patients; 25 of the 40 kidneys were retrieved by LDN and the other 15 by open surgery.

RESULTS

In all, 48 actual renal arteries were identified at nephrectomy; of these, 47 were predicted by CTA. Likewise, 41 actual renal veins were found at nephrectomy, 40 of which were predicted. The overall accuracy of spiral CTA in predicting the presence or absence of renal vein tributaries was 83% for gonadal and adrenal veins, and 75% for lumbar veins. There were seven false-negative lumbar veins found at nephrectomy; in these cases the CTA films were retrospectively examined, and five of these seven veins were identified. The predicted renal vein tributary diameter correlated poorly with the measured diameter at nephrectomy.

CONCLUSIONS

Assessing potential renal donors before surgery with spiral CTA provides an accurate prediction of the presence or absence of the gonadal and adrenal vein, but is less accurate for predicting lumbar veins. This is especially pertinent as the posterior lumbar tributaries have the most intra-individual variation, and are the most difficult to display and control at LDN. This highlights the need for meticulous dissection of the renal vein, particularly along its posterior wall.

Magnetic resonance angiography for preoperative evaluation of potential kidney donors1

BACKGROUND

Careful evaluation of the renovascular anatomy for living kidney donors is essential to optimize donor and recipient outcomes. Arteriography has been the standard for delineating the renovascular anatomy. However, this procedure is invasive. Magnetic resonance angiography (MRA) is an attractive, noninvasive alternative. The aim of this study was to evaluate the accuracy of MRA in potential living kidney donors.

METHODS

A retrospective comparison of the preoperative MRA results with the intraoperative anatomy was performed in 189 living kidney donors.

RESULTS

MRA interpretations correctly identified the vascular anatomy of the donor kidneys in 173 donors (91.5%). In the remaining 16 patients (8.5%), the MRA interpretation was inaccurate. In 10 patients, the MRA reported fewer arteries than the number encountered during the donor operation, whereas in six patients MRA reported more arteries than what found during operation. In seven patients, MRA supplied additional important anatomical information, including kidney size disparity, the presence of nephrolithiasis, the presence of a renal cyst, and renal artery stenosis. All kidneys were successfully transplanted. The misinterpretation of the MRA did not adversely affect the recipient outcome.

CONCLUSION

The noninvasive MRA evaluation of donor renovascular anatomy is an acceptable substitute for traditional angiography.

Multi-detector row CT evaluation of living renal donors prior to laparoscopic nephrectomy

Since its introduction in 1995, laparoscopic nephrectomy has become the preferred technique at many medical centers for the harvesting of kidneys from living donors for transplantation. Because the field of view at laparoscopic surgery is limited, preoperative radiologic evaluation of the donor's anatomy---the renal veins and arteries, collecting system, and parenchyma--is critical. Spiral computed tomographic (CT) angiography is a fast, safe, minimally invasive, and generally accepted method for preoperative evaluation of the renal vessels. Multi-detector row CT scanners offer shorter image acquisition time, narrower collimation, better spatial resolution, and less tube heating than do single-detector row CT scanners. Multi-row scanners also provide more complete anatomic coverage, increased contrast enhancement of the arteries, and greater longitudinal spatial resolution--all of which are important both for accurate imaging of the renal vasculature and for three-dimensional postprocessing of image data. Dual-phase multi-detector row CT angiography combined with three-dimensional postprocessing enables minimally invasive and highly accurate depiction of the preoperative donor anatomy. To make the most effective use of this method, radiologists must be familiar with its technical aspects, advantages, and potential pitfalls. They also must be able to identify variations in vasculature and in renal and extrarenal anatomy that are important for laparoscopic donor nephrectomy.

Complications of Hand-Assisted Laparoscopic Urologic Surgery

Since the first urologic case was reported in 1997, hand-assisted laparoscopic surgery (HALS) has proven to be useful for both the experienced and the inexperienced laparoscopic surgeon. In a recent series of 196 cases at three major medical institutions, 18 patients (9.2%) suffered 32 major complications, and 28 patients (14.3%) had 31 minor complications. The most common major complications were small-bowel injury, requirement for open conversion to control bleeding, and need for reintubation. The most frequent minor complications were urinary retention, splenic capsular injury, and prolonged ileus. The author discusses ways of recognizing and managing the complications of HALS, including physiologic, access-related, intraoperative, and post-operative problems.

Computerized Tomography With 3-Dimensional Reconstruction for the Evaluation of Renal Size and Arterial Anatomy in the Living Kidney Donor

PURPOSE

Computerized tomography (CT) with 3-dimensional (3-D) reconstruction has gained acceptance as an imaging study to evaluate living renal donors. We report our experience with this technique in 199 consecutive patients to validate its predictions of arterial anatomy and kidney volumes.

MATERIALS AND METHODS

Between January 1997 and March 2002, 199 living donor nephrectomies were performed at our institution using an open technique. During the operation arterial anatomy was recorded as well as kidney weight in 98 patients and displacement volume in 27. Each donor had been evaluated preoperatively by CT angiography with 3-D reconstruction. Arterial anatomy described by a staff radiologist was compared with intraoperative findings. CT estimated volumes were reported. Linear correlation graphs were generated to assess the reliability of CT volume predictions.

RESULTS

The accuracy of CT angiography for predicting arterial anatomy was 90.5%. However, as the number of renal arteries increased, predictive accuracy decreased. The ability of CT to predict multiple arteries remained high with a positive predictive value of 95.2%. Calculated CT volume and kidney weight significantly correlated (0.654). However, the coefficient of variation index (how much average CT volume differed from measured intraoperative volume) was 17.8%.

CONCLUSIONS

CT angiography with 3-D reconstruction accurately predicts arterial vasculature in more than 90% of patients and it can be used to compare renal volumes. However, accuracy decreases with multiple renal arteries and volume comparisons may be inaccurate when the difference in kidney volumes is within 17.8%.

Multidetector CT angiography for preoperative evaluation of living laparoscopic kidney donors

OBJECTIVE

The purpose of this study was to determine the accuracy of multidetector CT (MDCT) angiography as the primary imaging technique in the evaluation of living kidney donors.

SUBJECTS AND METHODS

Seventy-four consecutive living kidney donors (30 men, 44 women; mean age, 41.7 years) who underwent MDCT were evaluated. CT examination was performed with 120 mL of IV contrast material at an injection rate of 3 mL/sec and a pitch of 6. In every case, arterial and venous phase volumetric data sets were acquired at 25 and 55 sec, respectively. Scans were reconstructed at 1-mm intervals for three-dimensional (3D) imaging using a volume-rendering technique. Axial CT images and 3D CT angiography were evaluated prospectively by one reviewer and retrospectively by two reviewers who had no knowledge of surgical results. Surgical correlation for the location of primary and accessory renal arteries, early branching of the renal arteries, and renal vein anomalies was made.

RESULTS

Seventy-two subjects underwent left nephrectomy, and two subjects underwent right nephrectomy because supernumerary left renal arteries were detected on preoperative CT angiography. Eighteen supernumerary renal arteries (two arteries to 16 kidneys and three arteries to one kidney) to 74 kidneys underwent nephrectomy. CT and surgical findings agreed in 93% of subjects (the average of three reviewers; range, 89-97%). Two small accessory renal arteries were missed by all three reviewers. Those arteries were diminutive and were thought to be insignificant by the surgeons. Early branching of the renal arteries was shown in 14 arteries, and CT and surgical findings agreed in 96% (the average of three reviewers; range, 93-97%). Renal vein anomalies were present in eight subjects, and CT and surgical findings agreed in 99% of the cases (range, 96-100%).

CONCLUSION

MDCT angiography is highly accurate for detecting vascular anomalies and providing anatomic information for laparoscopic living donor nephrectomy.

MR imaging: a "one-stop shop" modality for preoperative evaluation of potential living kidney donors

At many institutions, magnetic resonance (MR) angiography is the technique of choice for assessment of the renal arteries and renal parenchyma in potential living kidney donors. The renal arteries and renal veins have a varied anatomy and may consist of one or more vessels at several levels with variable calibers and levels of branching. These findings may play an important role in the surgeon's decision about which kidney to harvest, especially if laparoscopic nephrectomy is used. A comprehensive MR imaging protocol is used at one hospital to assess the arteries, veins, parenchyma, and collecting system of the kidneys. The protocol includes T2-weighted single-shot fast spin-echo imaging, fat-saturated T2-weighted fast spin-echo imaging, three-dimensional MR angiography and MR venography, and delayed fat-saturated three-dimensional T1-weighted gradient-echo imaging. Meticulous assessment of the source images as well as images produced with various postprocessing methods, such as full maximum intensity projection, targeted maximum intensity projection, and axial and oblique reformation, allows detailed description of the vascular anatomy and its relationship to the collecting system and parenchyma to facilitate the surgeon's decision making. The findings of MR imaging are comparable with those of other imaging modalities.

Living renal donors: optimizing the imaging strategy--decision- and cost-effectiveness analysis

PURPOSE

To determine the most cost-effective strategy for preoperative imaging performed in potential living renal donors.

MATERIALS AND METHODS

In a decision-analytic model, the societal cost-effectiveness of digital subtraction angiography (DSA), gadolinium-enhanced magnetic resonance (MR) angiography, contrast material-enhanced spiral computed tomographic (CT) angiography, and combinations of these imaging techniques was evaluated. Outcome measures included lifetime cost, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios. A base-case analysis was performed with a 40-year-old female donor and a 40-year-old female recipient.

RESULTS

For the donor, MR angiography (24.05 QALYs and 9,000 dollars) dominated all strategies except for MR angiography with CT angiography, which had an incremental ratio of 245,000 dollars per QALY. For the recipient, DSA and DSA with MR angiography yielded similar results (10.46 QALYs and 179,000 dollars) and dominated all other strategies. When results for donor and recipient were combined, DSA dominated all other strategies (34.51 QALYs and 188,000 dollars). If DSA was associated with a 99% specificity or less for detection of renal disease, MR angiography with CT angiography was superior (34.47 QALYs and 190,000 dollars).

CONCLUSION

For preoperative imaging in a potential renal donor, DSA is the most cost-effective strategy if it has a specificity greater than 99% for detection of renal disease; otherwise, MR angiography with CT angiography is the most cost-effective strategy.

Three-dimensional navigator for retroperitoneal laparoscopic nephrectomy using multidetector row computerized tomography

PURPOSE

We evaluated the efficacy of a 3-dimensional (D) navigator for retroperitoneal laparoscopic nephrectomy.

MATERIALS AND METHODS

A total of 21 patients with malignant localized renal (16) or ureteral (5) neoplasms underwent multi-detector row computerized tomography. The 3-D navigator was created using volume rendering technique. These findings were compared with videos obtained during laparoscopy.

RESULTS

The 3-D navigator depicted all renal arteries (100% sensitivity) and 24 of the 25 renal veins (96% sensitivity). Hilar anatomy, including the tumor, major vessels and adrenal gland, and their relationships were visualized as in laparoscopic views.

CONCLUSIONS

The 3-D navigator has a potentially important role in retroperitoneal laparoscopic nephrectomy. It is able to guide surgeons and aid in avoiding operative risks and possible complications.

Comprehensive MR imaging in the preoperative evaluation of living donor candidates for laparoscopic nephrectomy: initial experience

PURPOSE

To evaluate the accuracy of magnetic resonance (MR) imaging in the preoperative evaluation of potential living renal donors who are candidates for laparoscopic nephrectomy.

MATERIALS AND METHODS

Twenty-eight donor candidates who underwent subsequent laparoscopic nephrectomy were examined by using a torso phased-array coil at 1.5 T. Gadolinium-enhanced MR angiograms, MR venograms, and MR urograms were obtained in all patients by using an interpolated three-dimensional T1-weighted spoiled gradient-echo sequence (3.4-6.8/1.2-2.3 [repetition time msec/echo time msec], 25 degrees -40 degrees flip angle). Interpretation of the MR images was used to assess the arterial, venous, and ureteral anatomy, as well as parenchymal masses and scarring, and findings were compared with the surgical findings in all patients. Statistical evaluation was performed, with the surgical findings as the reference standard.

RESULTS

At MR imaging, 31 of 32 renal arteries and one of three early-branching arteries were identified correctly. The correct venous anatomy was identified in 23 of 28 patients, including a single left renal vein anterior to the aorta (n = 16), retroaortic left renal vein (n = 2), circumaortic left renal vein (n = 2), and single right renal vein (n = 3). A single collecting system in all harvested kidneys was identified correctly with MR urography. Overall, MR imaging correctly depicted vascular, ureteral, and parenchymal anatomy in 21 of 28 patients. Twenty-seven of 28 patients underwent successful laparoscopic donor nephrectomy on the basis of the MR findings. One procedure was converted to open nephrectomy on the basis of complex venous anatomy not prospectively identified on the MR images. The sensitivity and positive predictive value of MR imaging in correctly determining the combined vascular, ureteral, and parenchymal anatomy in the harvested kidney were 75% (21 of 28) and 95% (21 of 22), respectively.

CONCLUSION

Comprehensive gadolinium-enhanced MR imaging can depict the vascular anatomy, collecting system, and renal parenchyma preoperatively in patients who are candidates for laparoscopic living-donor nephrectomy.

MR angiography and preoperative evaluation for laparoscopic donor nephrectomy

OBJECTIVE

The purpose of our study was to evaluate the effectiveness of gadolinium-enhanced MR imaging in imaging arterial, venous, and ureteric anatomy in a group of potential laparoscopic renal donors and to compare our findings with those established at surgery.

SUBJECTS AND METHODS

Sixty-four consecutive patients underwent successful laparoscopic donor nephrectomy. Imaging of the kidneys was performed before surgery with MR imaging and breath-hold three-dimensional gadolinium-enhanced MR angiography. All studies were reviewed prospectively by one of two attending radiologists. Results were compared with findings at the time of laparoscopic nephrectomy.

RESULTS

Of the 64 patients, MR imaging and MR angiography identified 30 patients with normal arterial, venous, and ureteric anatomy, and concordance was found at surgery in 29 of these patients. Vascular anomalies were depicted on MR imaging in 34 patients, with complete concordance at surgery in 29 patients. The use of MR angiography for revealing arterial anomalies had a sensitivity of 89.4%, specificity of 94.1%, and accuracy of 90.6%. For venous anomalies, there was a sensitivity of 98.3%, specificity of 100%, and accuracy of 98.4%. No important utereric anomalies were identified at surgery or on MR imaging.

CONCLUSION

Renal MR imaging and gadolinium-enhanced MR angiography provide a safe, accurate, and minimally invasive means of comprehensive assessment of the potential living renal donor.

Evaluation of prospective living renal donors for laparoscopic nephrectomy with multisection CT: the marriage of minimally invasive imaging with minimally invasive surgery

Laparoscopic technique for excision of a kidney from a living donor has advantages over conventional open surgery, but operative visibility and surgical exposure are limited. Preoperative multisection computed tomography (CT) can provide necessary anatomic information in a minimally invasive procedure. A three-phase examination is suggested: (a) imaging from the top of the kidneys to the pubic symphysis with a section width of 2.5 mm and no contrast medium, (b) scanning of the kidneys and upper pelvis during the arterial phase of enhancement with a section width of 1.0 mm, and (c) scanning of the kidneys and upper retroperitoneum during the nephrographic phase of enhancement with a section width of 1.0 mm. Emphasis in this article is placed on analysis of the venous anatomy because most radiologists are unfamiliar with the anatomic variations. Conventional radiography of the abdomen and pelvis is performed after CT to evaluate the collecting system and ureters and to provide a lower total radiation dose than if CT were used. Of several postprocessing techniques that may be used, the authors prefer maximum intensity projection for arterial evaluation and multiplanar reformatting for venous evaluation.