Impact of Vascular Variations on Living Donor Kidney Transplantation ()
1. Introduction
Chronic kidney failure is a public health issue worldwide, particularly in our country. Kidney transplantation is the best cure. It allows reduction of the health costs as well as morbidity and mortality. It also improves quality of life and social reinsertion better than dialysis which was the only solution until recently [1]. Living donation is better than deceased donation as it gives an excellent quality of the renal graft. This procedure relies on many guidelines specifying donor-recipient selection. The harvesting of kidneys with multiple arteries or veins is a matter of discussion [2]. Some authors refute it because of the technical complexity of this harvesting, of the vascular reconstruction and the anastomosis. It could have a negative impact on the operation time and the occurrence of complications during kidney transplantation. The aim of this paper was to analyse the effects of variations of kidney pedicles on the surgical results of kidney transplantation. Specific objectives were to describe the variation of the renal pedicle and to point out the link between renal pedicle variation, operation time, and occurrence of complications.
2. Method
It was a retrospective analytic study conducted at the Cardiology Institute of Abidjan (Institut de Cardiologie d’Abidjan) from September 2012 to February 2017. Permission was obtained from the institution authorities and the manager of the kidney transplantation program. All the files of patients included in the program of living donor kidney transplantation stored in this institution were selected. The files with missing information regarding vascular anomalies, occurrence of complications and patients living out of the country were excluded. Finally, 49 couples (donor-recipient) were selected. Data were anonymously collected using a standardized questionnaire including socio-demographic and operating data. The first part of the statistical analysis was descriptive. It presented the distribution of each variable using numbers and percentages. The second part of the analysis was the analytic study. We used vascular anomaly as a criterium to create two groups: group 1 existence of vascular anomaly and group 2 absence of vascular anomaly. We computed the correlation of ischemia delay, operating time, occurrence of complication and death. Statistical tests were Pearson Chi2 test (when the conditions were not suitable the Fisher exact test was applied) and the Mann-Whitney test. The significant level alpha was 5%. We used STATA software 14.2 version for statistical analysis.
There was no funding for this study.
3. Results
Donors were young with a mean age of 37.59 years (range 21 to 58 years). (Figure 1)
Male patients represented 79.69% of donors (male-to-female sex ratio was 3.9). In 75.51% of cases, the left kidney was removed. It was transplanted in the left iliac fossa in the recipient.
A vascular anomaly was observed in 46.94% of donors. The number of arteries and veins on the renal grafts was variable (Table 1). We observed 1 to 3 arteries or veins in the donors (Figure 2).
Figure 1. Distribution of patients’ ages according to their status.
Table 1. Distribution of vessel number in the donor.
Variables |
Number |
Effective |
% |
Artery |
1 |
31 |
63.7 |
2 |
16 |
32.65 |
3 |
2 |
4.08 |
Vein |
1 |
39 |
79.59 |
2 |
9 |
18.37 |
3 |
1 |
2.04 |
Figure 2. Transplantation of a left kidney in the left iliac fossa with a pedicle containing one artery (green) and two veins (blue) (Image Coulibaly Noël).
A complication was noted in 11.22% of patients. Operating time was 180 min in 55.10% of recipients. This delay was above 240 min in 51.02% of donors (Table 2).
Table 2. Distribution of operation time according to the status.
|
|
Status |
Total |
|
|
Donor |
Recipient |
|
≤180 min |
- |
27 (55.10%) |
27 (27.55%) |
Operating time |
180 to 240 min |
24 (48.98%) |
22 (44.90%) |
46 (46.94%) |
|
>240 min |
25 (51.02%) |
- |
25 (25.51%) |
Total |
49 (100%) |
49 (100%) |
98 (100%) |
Vascular anomalies were associated with a longer operation time. This difference was not statistically significant (p = 0.5804).
There was no link between ischemia time and vascular anomalies (Table 3).
Table 3. Distribution of ischemia time according to vascular anomaly.
|
Vascular anomalies |
p |
|
No |
Yes |
Cold ischemia |
182 min (0 - 235) |
199 min (0 - 240) |
0.8389 |
Hot ischemia |
44 min (39 - 50) |
44 min (38 - 48) |
0.9838 |
Total |
216 min (0 - 279) |
233 min (0 - 281) |
0.7666 |
There was no link between complications and vascular anomalies (Table 4).
Table 4. Occurrence of complications.
|
|
Vascular anomalies |
p |
|
|
No |
Yes |
Complications |
No |
26 (53.06) |
23 (46.94) |
0.086 |
Yes |
8 (72.73) |
3(27.27) |
4. Discussion
Chronic kidney failure is frequent in sub-Saharan Africa. Dialysis which is a stand-by process is most of the time the only management available. The advent of kidney transplantation in an underequipped environment provokes and hope for patients with chronic kidney failure. If we had to follow the guidelines, donors with renal vessel anomalies should be excluded from our program. This would lead to a lack of donors. Moreover, there is a lack of studies about arterial and veinous vascularisation of black people in the context of kidney transplantation. Our series of 49 patients (Figure 1) of both sexes gave us the opportunity to observe the number of arteries, their origins, and their hilar or polar destiny allowing an arterial systematisation of the kidney. The renal artery was unique in most of the cases (63.3%) (Table 1 and Figure 2). Tardo [3] in 93.1%, Salih [4] in 68% and Abuelnour [5] in 81.05% observed also a unique renal artery. Anatomic variation of number and direction are important in renal surgery. Injuries to these terminal vessels may lead to important bleeding, partial ischemia of the kidney, a renovascular high blood pressure [6] [7] and be a source of complications in kidney transplantation surgery [8]. Regarding veinous anomalies of the renal pedicle, our results found a prevalence of multiple renal veins in 20.41% of donors. Literacy mentions a prevalence of veinous anomalies between 14% and 32% in the general population. Vein anomalies are most frequently located on the right side [9].
Finally, vascular anomalies were quite frequent in our population. It accounted for 46.94% of donors. In front of these anomalies, the complexity of organ removal, vascular reconstruction and anastomosis, some authors reject the transplantation. For them, these anomalies extend the operation length and promote the occurrence of complications. We found no statistically significant difference in operating time, ischemia time, occurrence of complications and existence of vascular anomalies or not (Tables 2-4).
Nowadays, it is well established that ischemia time participates in the prognosis of kidney transplantation. So, whoever is the donor, this ischemia time should be as short as possible. The risk of differed function and non-function of the graft are linked to this parameter [10]. Furthermore, long cold ischemia increases the risk of transplant rejection [11].
The systematic review made by Ahmadi [12] regarding the recommendations about eligibility criteria for living kidney donation, observed that vascular anomalies should no longer be a contraindication for donation even if the operation time is longer (p = 0.005) [13].
We were confronted with limitations due to the retrospective design of our study. The review of radiology reports and operative protocols without mention of all the anatomic variations could have led to some errors.
5. Conclusion
The prevalence of anatomic anomalies of the renal pedicle is high in a sample of the black African kidney donor population (46.94%). Nevertheless, there was no lengthening of operating time and no influence on complications occurrence. Kidneys with multiple arteries and/or veins can be transplanted with security with a good graft survival rate. Regarding the increasing rate of patients on waiting lists, it is possible to enlarge the selection criteria for donor candidates to realise more living donor kidney transplantations in the best conditions.