Kidney Transplantation

Kidney transplantation is performed to prolong and improve the lives of those with end-stage renal disease. Open and laparoscopic surgery are the two approaches for both procurement and transplantation. The main surgical indication is end-stage renal disease. This activity reviews the evaluation and treatment of end-stage renal disease and highlights the role of the interprofessional team in evaluating and treating this condition.

Objectives:Describe the epidemiology of kidney transplantation.Review the evaluation of kidney transplantation.Outline the management options available for end-stage renal disease.Summarize some interprofessional team strategies that can be employed to ensure optimal outcomes for patients who need kidney transplantation.Access free multiple choice questions on this topic.

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Kidney transplantation is often the preferred treatment for those with end-stage renal disease.[1] The discipline of kidney transplantation has grown tremendously over the past 50 years. Patients with end-stage renal disease have better long-term survival if they are placed on the waiting list and eventually undergo kidney transplantation than those who stay on dialysis.[2]

Furthermore, those who undergo transplantation often experience a better quality of life and a projected survival benefit of 10 years over those who remain on dialysis.[2] Since kidney transplantation was first successfully performed by Dr. Joseph Murray in 1954, there have been major developments in transplantation and immunology, allowing for a wider selection of acceptable donors and recipients.

In the classical anatomic position, the kidney's hilar structures are organized from anterior to posterior in the following order: renal vein, renal artery, and ureter/renal pelvis.[4] The renal arteries come directly off of the aorta laterally just below the takeoff of the superior mesenteric artery to supply each kidney. The right renal artery traverses behind the inferior vena cava. The renal artery then divides into its anterior and posterior divisions. The anterior division supplies 75% of the blood to the kidney, and the posterior division supplies 25%.[3] The arterial divisions divide into segments; the anterior division divides into four segments: apical, upper, middle, and lower and the posterior division becomes the posterior segmental branch.[5] Segmental arteries are end arteries and thus do not demonstrate collateralization. Consequently, the parenchyma they supply is susceptible to ischemic injury in the event they are injured/occluded. Lastly, further branching of the segmental arteries gives rise to interlobar arteries, then arcuate arteries, and finally interlobular arteries.

The renal vein is most often found anterior to the renal artery. Similar to the arterial distribution, the venous plexus capillaries coalesce into arcuate veins, which then drain into interlobular veins, trunks, and finally the renal vein.[3] The right renal vein is often short given the ipsilateral location of the vena cava, drains directly into the cava, and has no tributaries. The left renal vein courses anterior to the aorta to reach the inferior vena cava. As such, it is 2 to 3 times longer than the right renal vein. Unlike the right renal vein, the left renal vein has many tributaries: gonadal vein, adrenal vein, inferior phrenic, lumbar, and paravertebral veins.[3] Of note, the SMA can reliably be found anterior and superior to the left renal vein as it crosses the aorta. All things being equal, the left kidney is preferred in living donation secondary to its extra length, which tends to make anastomosis technically easier to perform.

The incidence of end-stage renal disease (ESRD) is rapidly rising. The most common etiologies of renal failure are diabetes and hypertension.[6] Other causes of CKD/ESRD are grouped into prerenal (chronic or acute ischemia), intrinsic renal (glomerulonephritis, focal-segmental glomerulosclerosis), or postrenal categories (reflux nephropathy, obstruction). Patients who reach chronic kidney disease (CKD) stage 4, which correlates to a glomerular filtration rate (GFR) less than 30 mL/min/1.73 m, should be seeing a nephrologist and educated about kidney failure and treatment options, including transplantation.[7]

In the absence of contraindications for transplantation, the nephrologist will refer the patient to a transplant center, in addition to setting in motion the necessary interventions for possible initiation of dialysis. There is a clear survival benefit for kidney transplant recipients over those who remain on dialysis.[8] And the length of time on dialysis is an independent risk factor for poorer outcomes.[2]

Absolute contraindications for kidney transplantation are the inability to tolerate surgery due to severe cardiac or pulmonary disease, active malignancy, active infection, active drug abuse, and uncontrolled psychiatric disease.

Relative contraindications are more variable and may differ depending on the institution and geographic region: morbid obesity with a recommended body mass index (BMI) less than 40 kg/m, history of noncompliance with dialysis schedule or medication regimen, frailty, psychiatric problems, and limited life expectancy (defined as less than the anticipated waiting time for a kidney).[9]

Most ESRD patients have multiple co-morbidities and complications resulting from their kidney disease. As such, they are carefully screened for their ability to tolerate surgery and the subsequent immunosuppression which accompanies transplant surgery. Below is a summary of the evaluation of comorbid conditions:

Cardiovascular Disease: Most ESRD patients require careful cardiovascular evaluation with noninvasive testing for those at high risk or who have symptoms. For example, a dobutamine stress echocardiogram has been shown to have superior accuracy for predicting perioperative cardiac events.[10] The leading cause of death after kidney transplantation is cardiovascular disease.[11] Therefore, if noninvasive testing is positive, these patients should undergo cardiac revascularization before transplant surgery.

Cerebrovascular Disease: Any patient with a history of a cerebrovascular accident, including a transient ischemic attack, should be evaluated for carotid artery disease, if not already done.[12] Additionally, any history of polycystic kidney disease and accompanying symptoms warrants a magnetic resonance angiogram to screen for aneurysms.[13] Femoral and pedal pulses should be palpated. Further imaging (duplex US & CT) and possible referral to vascular surgery should be considered in the event of abnormalities in the peripheral pulse exam, history suggestive of PVD, and concerns regarding adequate iliac artery inflow, the intended site of implantation. Any revascularization deemed necessary should ideally be performed before a transplant.[14]

Gastrointestinal Disease: Anyone with a family or personal history of colon cancer or above the age of 50 should have a screening colonoscopy per USPSTF recommendations. Anyone with active viral hepatitis or chronic liver disease should consult with a hepatologist for possible consideration for a combined liver-kidney transplant.

Infections: As stated above, active infection is an absolute contraindication to a kidney transplant. Most centers will send a comprehensive serology panel to test for many viral infections and tuberculosis, etc. Vaccinations should also be up to date.

Pulmonary Disease: For higher-risk patients such as those who have been on dialysis for an extended period, those with heart dysfunction, known diagnosis of COPD or history of extensive tobacco use, obstructive sleep apnea, or history of pulmonary embolism should undergo pulmonary function testing and possibly an echocardiogram to rule out pulmonary hypertension.[17] For those who have severe pulmonary hypertension, preoperative treatment, and mitigation with vasodilators are recommended before transplantation surgery, in addition to pulmonology clearance.

Deceased donors are broken down into those that are brain dead (DBD) and those that donate after cardiac death (DCD). As the term would indicate, brain dead donors are those that have satisfied formal criteria for brain death testing. DCD donors are patients who, while they do not meet the criteria for formal brain death, are deemed by neurologists as being unlikely to experience a meaningful neurologic recovery.[18] In the case of DCD donation, procurement cannot begin until the heart has stopped beating, and an independent physician pronounces the patient following terminal extubation. Efforts by the United Network for Organ Sharing (UNOS) to further stratify deceased donors were delineated to reflect likely organ quality. Thus, deceased donors were defined as meeting standard criteria (SCD) or otherwise fell under the umbrella of extended criteria donation (ECD). ECD kidneys are associated with shortened graft longevity secondary to donor risk factors: age over 60, or those between 50 to 59 years of age with a history of hypertension, terminal creatinine concentration above 1.5 mg/dL, or cerebrovascular cause of death.[19]

Living kidney donation offers the best graft and recipient survival, even when considering paired kidney exchange, which involves organ transport before implantation.[20] The current eligibility criteria requirements are ages 18 to 70 years, BMI less than 35 kg/m, no active malignancy, no active infection, and adequate kidney function (~ GFR > 80). Absolute contraindications to living kidney donation are BMI greater than 40 kg/m, diabetes, active malignancy, human immunodeficiency virus (HIV) positivity, GFR less than 70 mL/min/1.72m, albuminuria, hypertension requiring more than 1 medication, pelvic or horseshoe kidneys, and psychiatric disorders.

Regarding long-term consequences to living kidney donors, much research has been done; initially, it was felt that eventual development of ESRD or long-term survival was not affected by living donation.[21] In the newer National Health and Nutrition Examination Survey (NHANES III) study, however, the development of ESRD in live donors was found to be slightly higher compared to matched healthy controls but no different than in the general population.[22] 17dc91bb1f