The general clinical evaluation answers: can the patient be transplanted? The urological and surgical evaluation adds another question: how are we going to transplant them, and is there any anatomical or functional condition we must resolve beforehand?
The preoperative assessment should establish the patient's clinical status, guide the choice of implant site, determine whether the vascular anatomy allows a conventional implantation, and define the condition of the urinary tract.
That is why the surgeon should arrive at the transplant knowing, as far as possible:
The history should begin long before a CT scan is reviewed. The following should be specifically recorded:
Because it can anticipate future problems. We need to know whether the kidney disease was related to:
The underlying kidney disease may also have implications for the possibility of recurrence in the graft.
Residual urine output is a simple but very important piece of information. Evaluating a patient who still urinates normally is not the same as evaluating a patient who has been anuric for several years.
In a patient with residual urine output we can obtain direct information about: frequency, stream strength, emptying, urgency, incontinence, infections, hematuria, pain, and the functional capacity of the bladder.
By contrast, after years of anuria we may find a bladder that has not fulfilled its normal storage function for a long time.
Clinical pearl
Do not ask only how much the patient urinates. Ask how they urinated before becoming anuric. An anuric patient may previously have had an obstruction, a neurogenic bladder, or a functional disorder that will reappear once the new kidney starts to produce urine.
The surgical examination should include aspects that often go unnoticed in a nephrology visit, among them: blood pressure, peripheral pulses, previous surgical scars, genitalia, urethral meatus, and vaginal evaluation when appropriate.
AbdomenLook for previous surgeries, scars, hernias, ostomies, large polycystic kidneys, and possible access difficulties.
PulsesAbsent or diminished femoral pulses should raise suspicion of vascular disease.
Genitalia and urethraLook for meatal stenosis, urethral pathology, genital abnormalities, and a history of instrumentation.
The idea is simple: any problem that could later impair urinary drainage must be known before the transplant.
We can organize the entire surgical assessment around three questions:
Conventional kidney implantation usually uses the recipient's iliac vessels, so we need to know the condition of the aortoiliac axes. Vascular disease can lead to:
Situations of particular interest:
Not all recipients require exactly the same vascular workup.
Key concept
Imaging should be individualized according to history and vascular risk.
Rather than just "ordering a CT," we must know what question we want to answer. CT angiography allows assessment of the aortoiliac axes and identification of: stenoses, elongations, aneurysms, calcifications, and the characteristics of the potential anastomosis site. It also allows selection of the most appropriate iliac fossa or territory for the arterial anastomosis.
The surgeon's question is: where is the best vessel to safely implant this kidney? Not simply "is there atheromatosis?"
This is an important surgical concept. An artery may be patent yet have a heavily calcified wall. This can make clamping, arteriotomy, suturing, anastomosis, and control of a possible vascular injury more difficult. Even without stenosis, extensive calcifications may exist that are capable of technically compromising the transplant.
Surgical pearl
A patent artery is not necessarily an artery suitable for anastomosis.
The graft should not automatically always be placed on the same side. The choice should consider: arterial quality, venous drainage, previous surgeries, previous transplants, urinary anatomy, scars, available space, and particular characteristics of the graft.
Preoperative imaging allows difficulties to be anticipated and the most appropriate site to be chosen; imaging is crucial for deciding where to place the graft in patients with vascular disease.
Not necessarily. Identifying vascular disease can lead to different strategies: conventional implantation, choosing the other fossa, prior revascularization, vascular reconstruction during the transplant, implantation in an alternative vascular territory, or, in selected cases, orthotopic transplantation.
Key concept
Vascular disease changes surgical planning; it does not automatically mean excluding the patient.
The arterial anastomosis is of no use if the graft does not have adequate venous drainage. For that reason we must also evaluate the iliac system, the vena cava, and collaterals when venous pathology exists.
We must pay special attention to patients with:
Thrombosis of the venous axis does not necessarily mean the transplant is impossible, but it completely changes the strategy. The question becomes: is there a venous territory capable of adequately draining the graft's flow?
Complex alternatives exist in selected situations, including the use of different venous territories when the iliac veins or the vena cava cannot be used conventionally. For the resident, the main concept is not to memorize every exceptional anastomosis, but to understand that venous patency and drainage capacity must be known before implantation when there are risk factors in the history.
This is probably the most specifically urological component. The ultimate goal is simple: the transplanted kidney must drain into a urinary tract that is anatomically and functionally adequate.
The assessment must analyze both anatomy and function and determine whether native nephrectomy or urinary reconstruction is needed before the transplant.
Look for a history of:
And again: does the patient have residual urine output? How do they void? How did they urinate before becoming anuric? This history anticipates complications after the transplant.
No. This is an important concept for the resident. Tests should be selected according to: underlying kidney disease, urologic history, symptoms, duration of anuria, previous surgeries, and suspected functional abnormality.
An initial evaluation is proposed, with deeper study in selected patients; cystourethrography is specifically mentioned when there is a history of LUTS, prolonged anuria, or urological nephropathy.
Key concept
We do not order tests by protocol. We seek to answer whether the urinary tract can adequately store and evacuate the urine from the new kidney.
A patient with years of oliguria or anuria may have a low-capacity bladder from disuse. But a small bladder does not necessarily mean a dangerous bladder.
What truly matters from a functional standpoint is knowing: capacity, compliance, storage pressure, emptying, continence, presence of obstruction, and reflux when applicable.
In patients with suspected neurogenic bladder or complex dysfunction, urodynamic evaluation is recommended and, when necessary, preparation for intermittent catheterization.
It should not be used routinely in every recipient. It is most useful when we suspect: neurogenic bladder, low compliance, a significant storage disorder, impaired emptying, congenital anomaly, a history of urinary reconstruction, or complex voiding symptoms.
Urologic pearl
The question is not "is the bladder small?", but "does the bladder store urine at low pressure and can it empty adequately?"
A recipient who will begin to produce urine after the transplant needs an adequate urinary outlet. In men we must assess, according to age and context: previous symptoms, history of retention, prostate, urethra, residual volume when there is urine output, and additional studies if indicated.
Prostate evaluation with PSA and digital rectal exam is included in the pretransplant context, together with the need to assess the urinary tract before implantation.
The point is not to systematically operate on the prostate before transplanting. It is to detect a clinically relevant obstruction that could compromise later function.
The evaluation may uncover a pathology that is best resolved before implanting the new kidney. It can be conceptually divided into two groups.
Lower urinary tractMay require: correction of obstruction, urethral treatment, management of neurogenic bladder, training in intermittent catheterization, or bladder reconstruction in selected situations.
Native kidneysThey should not be removed systematically. Situations in which native nephrectomy may be considered: infections associated with reflux, infected stone disease, certain situations with massive proteinuria, polycystic disease with infections, or very large kidneys that leave no room for the graft.
Key concept
The goal is not to "clean up" the patient before the transplant. Every previous surgery must have a specific indication.
Surgical history can radically change the strategy. We need to know about: previous transplants, graft nephrectomies, nephrectomies, vascular surgery, abdominal or pelvic surgery, urinary reconstructions, diversions, and femoral vascular accesses.
An abdominal scar may be just a scar. But it may also represent fibrosis, vascular alteration, difficult dissection, anatomical modification, or the need to change the implant site. That is why previous scars are an explicit part of the physical examination.
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Potential recipient:
1. Medical historySignificant vascular risk?
Is there a safe site for anastomosis?
History of DVT, multiple catheters, thrombophilia, or previous transplants?
Residual urine output and adequate voiding?
Surgical plan defined
After completing these six steps, the surgeon should be able to say where the graft will be implanted, where the vascular anastomoses will be performed, and where and how the urinary reconstruction will be performed.
Before implantation you should be able to answer:
Clinical pearl for residents
The worst situation is discovering in the operating room a vascular or urinary problem that could have been diagnosed earlier. Pretransplant evaluation turns a potentially unpredictable operation into a planned one.
What are the three major components of the surgical evaluation of the recipient?
Correct: B.
A patent iliac artery is necessarily suitable to receive an anastomosis:
Correct: B.
What information should be specifically asked for in a dialysis patient?
Correct: B.
Do all recipients need urodynamics?
Correct: B.
A patient with severe peripheral vascular disease is automatically excluded from transplantation:
Correct: B.
Is nephrectomy of the native kidneys routine?
Correct: B.
In a patient who has been anuric for years, an important question is:
Correct: A.