Fate of Accessory Renal Arteries in Grafts with Multiple Renal Arteries during Live-Donor Renal Allo-Transplantation

The accessory renal arteries: A systematic review with meta-analysis

The accessory renal arteries (ARAs) are a well-described variant of the renal vasculature with clinical implications for radiologists, surgeons, and clinicians. The aim of the present systematic review with meta-analysis was to estimate the pooled prevalence of ARAs, including their variant number, origin, and termination, and to highlight symmetrical and asymmetrical morphological patterns. The systematic review used four online databases in accordance with PRISMA 2020 and Evidence-based Anatomy Workgroup guidelines. R programming software was used for the statistical meta-analysis. A total of 111 studies were considered eligible for our initial aim. The typical renal artery (RA) anatomy (a single bilateral vessel) was identified in 78.92%; the overall ARA prevalence was estimated at a pooled prevalence of 21.10%. The estimated pooled prevalence of one, two, three, and four ARAs were 18.67%, 1.80%, 0.01%, and <0.01%. The ARAs have been the subject of extensive research owing to their clinical importance, including in kidney transplantation surgery and resistant hypertension therapy. Knowledge of the typical and variant anatomy of RAs is essential for anatomists, radiologists, surgeons, and clinicians in order to avoid misunderstanding, complications, and iatrogenic injury.

Safety and Intraoperative Results in Live Kidney Donors with Vascular Multiplicity After Hand-Assisted Laparoscopy Living Donor Nephrectomy

Background and Purpose

Vascular multiplicity is the most frequent anatomic variation in kidney donors. Despite concerns about risks, these allografts are increasingly used to overcome the shortage of kidney donors. The safety and clinical outcomes in living kidney donors were evaluated with vascular multiplicity after hand-assisted laparoscopic living donor nephrectomy (HALDN).

Patients and Methods

Data from all living kidney donors who underwent HALDN from 2008 to 2021 was retrospectively reviewed. Patients were divided into two groups as single (SRV) and multiple renal vessels (MRV), and a comparative analysis was done. The primary outcomes include operating room time (ORT), days of hospital stay, estimated blood loss, complications, conversion, and re-operations.

Results

MRV were present in 166 out of 612 donors (27.1%). Among those, 10 (1.6%) donors had simultaneous multiple arteries and veins. Additionally, the prevalence of artery and vein multiplicity was 21.8% (n = 134) and 3.5% (n = 22), respectively. Warm ischemia time was significantly different among the two groups but not clinically important. The number of conversions to open technique, the mean ORT, the median blood loss, and days of hospital stay were similar between the SRV and MRV groups, without significant differences. According to the modified Clavien-classification system, no differences were found in the complication rates between the two groups (p = 0.29). Complication rates were 3.3% and 3.6% for the SRV and MRV groups, respectively.

Conclusion

HALDN is a procedure with safe intraoperative results, even with vascular multiplicity. The presence of multiple renal arteries or veins has no negative impact on the outcome of the donor after living donor nephrectomy.

A 2-mm Cutoff Value Is Reasonable and Feasible for Vascular Reconstruction in a Kidney Allograft With Multiple Arteries

BACKGROUND

Multiple renal arteries are found in approximately 20% of living donor kidneys. We have been using an accessory artery cutoff diameter of 2 mm on preoperative computed tomography angiography to determine whether to sacrifice or reconstruct the artery. In this study, we assessed the validity and feasibility of this cutoff value.

METHODS

Living related kidney recipients from 2005 to 2013 were enrolled in this retrospective study. The diameter of the accessory artery and adverse events were evaluated. The lost parenchymal volume (%) due to vascular obstruction or branch ligation was calculated by computed tomography volumetry.

RESULTS

Among 128 kidney transplants, 30 donor kidneys had multiple arteries. Accessory arteries were reconstructed in 18 cases and intentionally ligated in 12 cases (mean diameter of accessory arteries, 3.10 [SD, 0.75] mm and 1.81 [SD, 0.28] mm, respectively). The mean estimated glomerular filtration rate at 1 or 12 months after transplant was not significantly different between the groups. Among reconstructed cases, 14 cases (77.8%) had good patency in the reconstructed arteries whereas the other 4 had vascular complications. The percentage of lost parenchymal volume due to ligation or occlusion of the reconstructed artery (calculated in 16 cases) was predictable with the following formula: lost volume (%) = 9.09 × diameter (mm) - 10.5 (P= .03, r_s= 0.533 by Spearman rank correlation coefficient). This formula indicated that ligation of a 2-mm accessory artery leads to 7.68% loss of the renal parenchyma.

CONCLUSIONS

Reconstruction using a cutoff diameter of 2 mm is worth attempting in terms of the success rate and graft function. Sacrifice of a 2-mm accessory artery leads to parenchymal loss of <8%.

Morphological and clinical aspects of the occurrence of accessory (multiple) renal arteries

Renal vascularization variants vastly differ between individuals due to the very complex embryogenesis of the kidneys. Moreover, each variant may have implications for clinical and surgical interventions. The number of operating procedures continues to grow, and includes renal transplants, aneurysmorrhaphy and other vascular reconstructions. In any surgical technique, unawareness of the presence of multiple renal arteries may result in a fatal outcome, especially if laparoscopic methods are used. The aim of this review is to comprehensively identify the variation within multiple renal arteries and to highlight the connections between the presence of accessory renal arteries and the coexistence of other variants of vascularization. Another aim is to determine the potential clinical implications of the presence of accessory renal arteries. This study is of particular importance for surgeons, intervention radiologists, nephrologists and vascular surgeons.

Accessory (multiple) renal arteries - Differences in frequency according to population, visualizing techniques and stage of morphological development

The aim of this paper is to comprehensively analyze the literature focused on frequency of the presence of the accessory renal arteries in the human body. A systematic analysis of papers has been made. With regard to ethnicity, the incidence of accessory renal arteries fluctuates from 4% in a Malaysian population to 61.5% in a Brazilian population. The frequency is lowest in eastern and southern Asia (from 4% to 18.4%). In some, not ethnically homogenous populations, wide span of occurrence of accessory renal arteries is described (e.g. American - averaging from 18% to 28.8%). A higher frequency of accessory renal arteries was observed in fetuses compared to adults. Moreover, differences in the presence and number of accessory renal arteries reported in different papers are a consequence of type of visualizing technique used in research - especially when computed tomography and anatomical dissection were compared. The increasing number of surgical interventions, especially where laparoscopic methods are concerned, underlines the importance of such knowledge especially to surgeons, interventional radiologists, nephrologists, and vascular surgeons.

Salvage of grafts with vascular thrombosis during live donor renal allotransplantation: a critical analysis of successful outcome

OBJECTIVES

To report a high-volume institution experience with salvage techniques for vascular accidents during live donor renal allotransplantation.

METHODS

Between March 1976 and January 2011, 2208 recipients underwent live donor renal allotransplantation. A retrospective review of recipients with vascular accidents - renal artery thrombosis and renal vein thrombosis - was carried out. Salvage procedures were recorded and their outcomes were assessed.

RESULTS

A total of 23 (1%) vascular accidents occurred, including renal artery thrombosis and renal vein thrombosis in 19 (0.8%) and four (0.18%) recipients, respectively. All renal artery thrombosis patients were treated by open revascularization and the graft was salvaged in 12 patients (63%). Two renal vein thrombosis events were resolved by percutaneous catheter-directed thrombolytic therapy. Of the other two allografts, one was salvaged by thrombectomy and revascularization, and the other was lost. On univariable analysis, older recipients (P = 0.003), pretransplant hypertension (P =  0.001), more human leukocyte antigen mismatches (≥3; P = 0.036), shorter ischemia time (≤45 min; P = 0.004) and longer time to diagnosis (>3.5 days; P = 0.013) were significantly associated with non-salvage of the graft after vascular accidents. Nevertheless, none of these variables were significant on the multivariable analysis. Over a median follow up of 35 months, the median (range) serum creatinine was 2 mg/dL (range 0.8-8.8 mg/dL), and 11 (79%) recipients were living with functioning grafts.

CONCLUSIONS

Despite the devastating complications, vascular accidents are salvageable and revascularization is crucial for graft salvage. Angiographic percutaneous techniques are viable alternatives for renal vein thrombosis.