Live donor kidney transplantation. Information for donor and recipient
The first thing both donor and recipient and their relatives need to know is that living donor transplantation will only be justified and will be accepted after a rigorous risk / benefit study for donor and recipient, as well as an exhaustive Evaluation in accordance with the best ethical standards.
Information is also fundamental in this process. All the agents involved receive previously, and in detail, information of interest to near the type of studies that will prove the viability of the TRDV and the security of the donation.
The worldwide experience accumulated after more than 50 years of TRDV allows to offer a high security for the donation of one of the kidneys.
There is also unanimity of the best survival of grafts and patients in kidney transplantation when the kidney comes from a living donor with respect to a deceased donor. The reasons are multiple, including the fact that it is a programmed surgical procedure in which both the donor and the recipient arrive in an optimal situation for surgery, the optimal quality of the transplanted kidneys and the lower age of the recipients.
Is it risky to donate a kidney?
In general, the risk assumed by a kidney donor is lower than that assumed by other people who undergo general anesthesia and major surgery, since all donors have good health. However, all of them are informed of the risks inherent to anesthesia, surgery and possible intraoperative and postoperative complications, typical of any surgical intervention.
Particular emphasis should also be placed on detailing the circumstances that may arise when living with a single kidney, including exceptional risks, such as severe trauma or infectious or lithiasic medical problems that could compromise the function of the only existing kidney.
In the long term, it can be confirmed that the tendency to progressive loss of glomerular filtration is not significant in any age group; The hypertension does not increase in incidence with the passage of the years and even the vital expectations would be superior with respect to those who maintain the two kidneys since it is a healthy population.
Regarding pregnancy in donor women, there are no additional risks described in gestations in monorrenic patients because they were kidney donors, although special attention will be given to controls of blood pressure, weight gain and proteinuria, generally not different from those Which can be recommended to other types of pregnant women.
Current nephrectomy (removal of the kidney) is done by laparoscopy, with hospital stays being increasingly reduced. Donors should live a sedentary life for the first two weeks and after that period, and according to the type of work, the return to normal and personal work.
Sports activities can be performed by donors without any special care or limitation within 6-8 weeks of surgery. In any case, from the analysis of the large donor series it can be inferred that if strict selection criteria are maintained, long-term donor security can be considered guaranteed.
The quality of life studies of kidney donors appreciate improvements in the affective sphere and improvements in the perception of quality of life since the motivations for donation are continuously reinforced in all cases in which the transplantation continues to fulfill its function . In the case of spouses, in addition to an excellent graft survival, the additional advantages for the donor focus on the possibility of a more normal couple life, without the travel limitations imposed by the dialysis or the comorbidity associated with problems with Vascular access or others related to renal failure.
Finally, we present a table summarizing the main risks for the recipient of the living donor.
Study and selection of live kidney donor
The integral study of a live kidney donation aims at verifying the following requirements:
That the donation is free, conscious and disinterested. It implies, among other requirements, that the donor: a) does not suffer from cognitive or emotional disorders; B) it has an intellectual capacity and a level of communication that allows it to understand the information on risks and benefits; C) is not subject to external pressures, and d) does not seek material rewards of any kind.
That the donor has normal kidneys and the risk of developing long-term nephropathy is reduced: a) currently has normal renal function and is free of any significant analytical or structural renal impairment; B) absence of hereditary family nephropathy that may develop later, and c) there are no processes or alterations that increase the risk of nephropathy, for example, systemic diseases, severe hypertension (HTA) or diabetes.
That the donor does not present other diseases or alterations that may: a) increase surgical or anesthetic risk ) be impaired by a minor renal reserve, or c) be transmitted to the recipient, such as cancer or infections.
That the recipient is acceptable for transplantation: no contraindications, and its vital and rehabilitative prognosis is reasonably good and will improve significantly with TRDV.
That transplantation is technically possible with an acceptable risk: a) vessels and urinary tract are appropriate (donor and recipient), and b) there is no immunological incompatibility
Age: The minimum age for donation in our country is 18 years, for legal reasons. There is no well-established maximum age limit (although in Spain rarely the donation is considered more than 70 years).
Habits : Smoking and alcohol abuse (> 60g / day) may warrant further exploration and increase the risk of postoperative complications in general. The complete cessation of these habits is strongly recommended at least 4 weeks before the intervention. Definitive abandonment should be emphasized, since smoking increases the donor's long-term mortality risk. Addiction to drug abuse is a contraindication to donation.
Hypertension : Blood pressure at separate visits should be <140 / 90mmHg; The mean values of ABPM should be <135/85 mmHg during the day and <120/75 mmHg during sleep. The donation of a mild or moderate hypertensive without other cardiovascular risk factors and good renal function is admissible, provided certain conditions are met: a) age greater than 50 years; B) non-African American; C) absence of visceral repercussions of hypertension (ECG-echocardiography, fundus, microalbuminuria <30 mg / day); D) tension can be controlled by changes in lifestyle and use of no more than one hypotensive, and e) there is a reasonable assurance that the donor will continue to have control and treatment indefinitely. As in the general population, Hypertension is associated with higher donor mortality in the medium term. On the other hand, and although there are conflicting data, a recent meta-analysis seems to confirm that the donation is associated with an increase in blood pressure of 5 mmHg. In addition, with adequate selection and management of their hypertension, hypertensive donors do not appear to have poorer kidney function after donation, at least in the short term. All this would justify the use of mild hypertensive donors with life expectancy limited by their current age, if adequate control is to be expected. Hypertensive donors do not appear to have poor renal function after donation, at least in the short term. All this would justify the use of mild hypertensive donors with life expectancy limited by their current age, if adequate control is to be expected. Hypertensive donors do not appear to have poor renal function after donation, at least in the short term. All this would justify the use of mild hypertensive donors with life expectancy limited by their current age, if adequate control is to be expected.
Obesity: Severe obesity (BMI> 35) is a contraindication for donation, as it is associated with an increased surgical risk and long-term development of CKD. Obesity between 30 and 35 BMI (or waist diameter> 82 cm in women or> 102 cm in men) may also be a contraindication if it is associated with other risk factors such as hypertension, altered basal glycemia or family history, microalbuminuria. In any case, it should be noted that it is possible to have a greater risk in the long term and orientate itself to the donor in order to achieve maximum weight reduction before the intervention and to maintain it indefinitely through changes in eating habits.
Renal function: In patients below the age of 40 years a clearance> 90 ml / min / 1.73 m2, especially in obese subjects, is desirable, while many centers admit minor clearings (around 70 ml / min and even less) in donors Of older (> 60 years).
Proteinuria: A proteinuria> 300 mg / day rule donation . The value of microalbuminuria is not well established with respect to donation: a microalbuminuria> 30 mg / day is a relative contraindication. In the case of proteinuria (150-300 mg / day) or in the presence of microalbuminuria (30-300 mg / day), the donation tends to be discouraged, but the case may be assessed individually, taking into account other factors such as age, Obesity, hypertension or altered glucose metabolism.
Cardiovascular assessment: It aims to rule out significant heart diseases that are contraindicated by increased donor risk: ischemic heart disease, heart failure, valvulopathy, significant left ventricular hypertrophy or significant arrhythmia. Adequately selected donors do not seem to see their cardiovascular risk posttransplant increased.
Diabetes and metabolic syndrome: Minimum study: basal glycemia, HbA1c and lipid profile . Indication of functional tests, basically oral glucose tolerance test (TTOG ):
A) first-degree family history of type 2 diabetes;
B) altered basal glycemia (100-125 mg / dl) or HbA1c> 6-6.5%;
C) obesity, and
D) other data that complete or create risk of metabolic syndrome : hypertension, dyslipidemia (triglycerides> 150mg / dl or HDL cholesterol <35 in men / <39 in women), microalbuminuria.
Regarding the donation :
The antecedent or diagnosis of diabetes (baseline glycemia> 126 on two occasions or random blood glucose or at 2 hours on TTOG> 200) is an absolute contraindication for donation.
The history of gestational diabetes is an absolute contraindication, given the high rate of late development of diabetes.
The altered basal glycemia and the hydrocarbon intolerance (blood glucose at 2 hours between 140 and 199) are a relative contraindication and should be evaluated individually, taking into account the response to a simple intervention plan (diet, exercise, statins). The altered basal glycemia in the high range (110-125), the family history, the presence of other risk factors or metabolic syndrome predict a greater tendency for the later development of diabetes and renal involvement and would incline to discard the donation.
Respiratory: Respiratory function tests would be indicated in a clinic indicative of chronic lung disease and in large smokers.
Cancer screening : Studies are done of:
Colon: indicated according to recommendations for the general population: family history in the first degree, age> 50 years and others. Minimum: fecal occult blood . Recommended colonoscopy.
Breast: mammography / ultrasound for women> 40 years, or earlier if there is a family history.
Uterus: cervical cytology and genital ultrasound.
Prostate: rectal examination and prostate specific antigen for men> 50 years, or earlier if there is a family history of early prostate cancer.
Specific studies based on preliminary study findings or personal or family history; For example: dermatology examination if there is a family history of melanoma or a very high number of nevus.
The donation is ruled out if there is previous diagnosis of hematological, gastrointestinal, testicular, melanoma, lung, breast, renal or urinary cancer, choriocarcinoma or monoclonal gammopathy.
In selected cases in which the cancer is considered cured and without risk of transmission, the donation can be considered after discussion with the partner.
Indications and Contraindications of Kidney Transplantation
The main indication of living donor transplant is the early transplantation ( preemptive ). This will allow the patient to get rid of the complications of dialysis and, moreover, it has been shown to have better results than the transplantation performed when dialysis has already begun.
Prior indications of live kidney transplantation are univiteline twins and identical HLA siblings. In addition, we will have very favorable conditions when the donor is young and male.
Hyperimmunized patients
These patients can benefit from a live donation from identical HLA siblings or from those who share a haplotype or parents. If, with all the family members, the cross-test continues to be positive, then it is ideal to enter into hyperimmune renal transplant programs by sharing deceased donors or cross-living renal transplant programs. Before these desensitization therapies can be tested in these patients to check if the cross-test is negative with the living donors.
Patients candidates for pancreas-kidney transplantation
The best therapy for patients with type 1 diabetes mellitus and end-stage renal failure is a simultaneous, ideally anticipated transplantation of the pancreas and kidney with organs from the same deceased donor. Unfortunately the shortage of pancreatic donors is very pronounced, since the selection criteria include very young donor ages and with hardly acute comorbidity. This causes patients to spend long periods on dialysis waiting for the simultaneous transplant.
An alternative to simultaneous pancreas and kidney transplantation for type 1 diabetics with renal failure is sequential kidney transplantation from a living donor followed by a pancreas transplant from a deceased donor. This therapeutic strategy would have the advantage of being able to do live transplantation in advance, avoiding the morbidity of the dialysis
Diseases with high relapse rate in renal transplantation
Patients with kidney disease with a high rate of relapse after transplantation have an absolute contraindication for live renal donation. They may be relative in a first transplant, but if it results in recurrence of primary renal disease and this is the cause of graft loss, the contraindication is absolute for a second transplant.
Donor alive woman or donor with low weight
In kidney transplantation donor age and graft size are known factors that condition the long-term graft evolution. Women tend to have smaller kidneys, with 17% fewer nephrons than men. The number of nephrons per kidney has a positive correlation with the weight of the kidney and negative with the age of the individual. It has been described that the female sex of the donor due to the smaller size of the kidneys negatively influences the evolution of the grafts when they are transplanted to men.
Overall, the current evidence tells us that when the donor is female and the age is advanced and the recipient is male and young, we are not in the most appropriate circumstances to ensure good results in the medium and long term. Thus, this donor-receptor match would represent a relative contraindication for live renal donation. And as such a relative contraindication, if it is finally considered opportune to perform live transplantation with this type of donor, it should be after extensive information on the risks to donor and recipient.
In general, these more unfavorable conditions may be less important if an early transplant is being proposed, since the advantages of not going through dialysis are likely to compensate, at least in part, for the drawbacks of these types of donor pairs -receiver.
Monitoring the donor alive in the short, medium and long term
The causes of long-term mortality in renal donors are similar to those observed in the general population, with cardiovascular complications, neoplasias and traffic accidents being the most frequent.
The incidence of mortality is, in fact, lower than expected in relation to the general population, adjusted for age and sex.
Unilateral nephrectomy performed on a healthy person, therefore with excellent renal function and without added risk factors (hypertension, obesity, diabetes, etc.), does not carry a risk of long-term nephropathy. Successive revisions of very large series and with a long follow-up interval show this.
Elderly age at the time of donation may influence the deterioration of renal function in the long term, but similarly to what is observed in the general population as the age advances.
Arterial hypertension
The incidence of hypertension in long-term controlled donor series is similar to that observed in the general population and is more frequently detected, as expected, in older donors.
It is advisable for donors to perform periodic blood pressure checks, as early detection of blood pressure allows adequate treatment and prevents the development of more serious complications.
Postodonation gestational hypertension
Recently two publications have appeared that study the possible relation of the renal donation in the appearance of gestational problems. Reisaeter et al. Review the experience with Norwegian donors and conclude that the incidence of preeclampsia is more frequent in donors after donation than before and also more frequent
Than in a control group of non-donor women. On the other hand, Ibrahim et al. Published the experience of the Mayo Clinic and concluded that their donors also have a higher incidence of preeclampsia, gestational hypertension and gestational diabetes after donation than before. In both cases, these are retrospective studies that open a question and invite a more detailed analysis of this question, in case it is necessary to take this into account when informing potential donors.
Proteinuria
Reduction of renal mass as a result of nephrectomy minimally increases protein excretion in urine. But the incidence of long-term proteinuria in renal donors is highly variable according to published series.
Again, it is important to emphasize the importance of early detection of proteinuria, since treatment with angiotensin synthesis inhibitors (ACE inhibitors) or angiotensin receptor antagonists (ARBs), administered early, may be especially useful.
Renal insufficiency
Renal function of the remaining kidney satisfactorily suppresses renal mass decrease. Normally serum creatinine and glomerular filtration rate reach 70-80% of the value prior to nephrectomy and remain stable over the years. In elderly donors or with filtration in the low limit of normality it is possible to observe values of
Discretely affected serum creatinine. Short term recovery of renal function is worse as age increases at the time of donation, body mass index and especially the lower the glomerular filtration rate before donation. Black donors also have a lower recovery of baseline glomerular filtration rate.
It is currently recommended that prospective and systematic long-term donor follow-up and early treatment of individuals developing high blood pressure be recommended.
Other issues to consider
Currently one of the main and most worrying reasons for kidney graft loss is the rejection caused by the abandonment or irregular taking of immunosuppressive medication. This medication should be taken strictly to avoid these events, which can end with the loss of the graft.
Patients who receive a kidney from a donation in asitolia usually require longer hospital stay, given the characteristics of this type of transplant.
