Kidney Transplant saves precious lives. But it also qualifies as a major surgery involving complicated procedures. This holds true for both the donor kidney retrieval surgery and implantation of the donor kidney into the recipient (patient). Quite naturally, both surgeries may entail risks / possible complications during and after the procedures, both in the short & long term. It is these possible risks/complications of Kidney Transplant are what we aim to walk you through, today.
We will first cover the risk-profile associated with Kidney Donation followed by that for the Kidney Recipient. The article presents the list of complications as per the time points at which they usually appear after the surgery. Read on to get a comprehensive insight on the what-why-how of these complications below.
NOTE: This article only covers complications from the kidney transplant procedure. Adverse effects expected from anti-rejection & other medications that a kidney recipient is put on, will be explained in a separate article.
Kidney donation is a major surgery. It requires the donor to be put to sleep for the entire duration using General anaesthesia. Depending on the medication used for anaesthesia and/or how it is administered, there may be some complications either on table or after waking up after surgery. These may range from severe allergic reaction (anaphylaxis) to the drug or aspiration pneumonia which require emergency on-table management with appropriate medication, to sore throat, hoarseness, headache, nausea, vomiting which subside on their own or with minor medical management. Nowadays, a general anaesthesia drug challenge test (skin test) is being assessed both as a preventive & predictive measure. So in a nutshell such tests can check for how likely the patient is, to develop an allergic reaction to it. (2)
PAIN AT THE SITE OF INCISION OR DEEP VISCERAL PAIN AT THE LOIN CORRESPONDING TO THE DONATED KIDNEY
With removal of a kidney, a lot of tiny nerve fibres that normally supply it require severing off. This manifests as pain. After the donor wakes up from surgery, he/she is on heavy doses of pain-killing medication. S they do not feel the pain initially. There could be some heaviness / dragging sensation on the side of donated kidney. But in due course, as the effect of such medication wears off, some residual pain and discomfort may surface. This is an expected complication. In absence of other complications and with adequate rest, such pain gradually subsides by itself by the first month after kidney donation. However, if the pain suddenly intensifies or gets unbearable at any point such that it interferes with the donor’s daily life activities, the donor should immediately report it to the medical team to check for any possible complication.
SURGICAL WOUND INFECTION
Poor hygiene & not dressing the wound regularly or co-morbidities like type 2 diabetes could contribute to surgical wound Infection. This is treatable with appropriate anti-microbial / antibiotic medicines & treatment for the root cause (if any other).
Any surgery in the abdomen leaves an area of weakness within the muscles that make up the abdominal wall. Donors must avoid any activity that strains abdominal muscles (eg: lifting heavy weight) for at least 2 months after surgery. This is to allow the muscles to regain partial strength in a relatively uninterrupted manner. Else, it could lead to a persistently weak area within the muscles around the surgical wound. Any heavy activity could cause a section of peritoneum, fat or even intestines to bulge out from that weakened area. This is Hernia as the illustration above shows. It may need another surgery to treat it. Nobody wants that, right? So, make sure you follow all post transplant advice by your medical team to the tee.
Kidney donation involves cutting off the donor kidney from it’s native blood supply for retrieval. Following this, surgeons put tight clamps on the open ends of these vessels to securely close them off. These clamps remain there for the natural life of the donor. Poor surgical technique can cause the clamps on the arteries and veins to loosen up and worse still, come-off after surgery. This could cause massive internal bleeding as the image above shows. If this happens, the bleeding needs to be controlled immediately else the patient can go into shock due to blood loss. This complication needs re-operation to fix it.
In any surgery which involves cutting and clamping major blood vessels, the risk of blood clots can crop up. This is because, as soon as an artery or vein is cut, the body senses this as an injury that needs to be repaired immediately. Forming blood clots in a controlled manner is a part of this natural healing process. However, poor surgical technique and any unintentional injury to the delicate inner lining of such blood vessels with surgical instruments can trigger excessive blood clot formation. This needs immediate on-table management.
Death due to Anaesthesia complications or uncontrolled bleeding is possible. But this is extremely rare under competent surgical teams. The reported chances are as low as 0.03-0.06%.
Risks over the Long term
HIGH BLOOD PRESSURE
Your kidneys work in association with heart, blood vessels & certain hormones to help control your blood pressure in normal health. Post kidney donation, normally the remaining healthy kidney comfortably compensates and takes over the job for both kidneys. But sometimes, the donor may develop risk factors for hypertension based on their lifestyle choices or unrelated medical problems that may crop-up post kidney donation. In such a pressing scenario, the single kidney may find it a tad difficult to effectively control your blood pressure as opposed to when it has a healthy partner kidney. So, donors are encouraged to follow a healthy, active lifestyle with regular health check-ups.
ELEVATED PROTEIN LEVELS IN URINE
If the donor develops hypertension, it basically means that the blood that goes to the single kidney for filtration pushes & shoves through delicate kidney filters in the process. Ultimately, plasma proteins like Albumin that should normally remain in the bloodstream starts leaking through the filters quantities enough to show-up in the urine. Hence, the importance of maintaining a healthy, active lifestyle with regular clinical check-ups remains.
MENTAL HEALTH ISSUES
Overall, the majority of kidney donors report feeling satisfied & optimistic about their donation experience. However, in a minor subset of donors some mental health issues may crop up as listed below:
1️⃣ Absence of proper prior counseling and lack of adequate family/social support post organ donation may cause symptoms of anxiety and depression
2️⃣ The donated kidney could possibly fail in the recipient in the short term due to circumstances beyond the donor’s control. But it can cause feelings of regret, anger or resentment in the donor.
These are temporary and seeking out proper counseling and authentic, relevant information can play a strong role in keeping these negative feelings at bay.
COMPLICATIONS OF KIDNEY TRANSPLANT SURGERY FOR THE RECIPIENT
Post-kidney transplant complications in the recipient/patient come under three categories:
Vascular or related to blood vessels
Urologic or related to urine outflow
Nephrogenic i.e. related to the kidney tissue (3,4)
Here, we present all such complications (indicating their respective categories where applicable), based on the time point at which they occur after the transplant surgery.
The time points considered are:
During the surgery
Immediate post-operative period (0-7 days)
Short term (1 week to 3 months)
Long term (Beyond 3 months)
Intra-operative complications (During the surgery)
ADVERSE REACTION TO ANAESTHESIA
Kidney donation is a major surgery. It requires the donor to be put to sleep using general anaesthesia. The medicine used for anaesthesia and the method to administer it may cause some complications either on table or after waking up after surgery. These may range from severe allergic reaction (anaphylaxis) to the drug or aspiration pneumonia which require emergency on-table management with appropriate medication, to sore throat, hoarseness, headache, nausea, vomiting which subside on their own or with minor medical management. Nowadays, a general anaesthesia drug challenge test (skin test) is being assessed both as a preventive & predictive measure. In short, such tests can check for the likelihood of the patient to develop an allergic reaction to the anaesthesia medication. (2)
To implant a donor kidney in the patient’s abdomen, transplant surgeons need to connect it to major blood vessels. Poor surgical technique could lead to a delay in connecting the kidney and achieving haemostasis (sewing up the blood vessels to stop blood loss). This could cause excessive bleeding. If this happens, the patient can go into shock due to blood loss and needs emergency management with blood transfusions to fix it.
Any surgery on major blood vessels carries the risk of blood clots because of our body’s “protective” sensing mechanisms. As soon as an artery or vein is cut, the body senses the consequent bleeding as an injury needing immediate repair with controlled clotting. This is part of the natural healing process. However, any unintentional injury to the delicate inner lining of such blood vessels with surgical instruments can send the body’s healing mechanisms into a tizzy & trigger excessive blood clot formation. This can cause heart attack, stroke, is potentially fatal and needs immediate on-table management.
Hyper-acute rejection (5) can occur from the time of transplant to 48 hours after transplant. Here, a hostile army of cytotoxic antibodies (6)within the recipient’s bloodstream identify & attack tissue antigens (identity proteins) present on the surface of the donor organ. This causes a flurry of immune cells to mount an immune offensive which ultimately ends up blocking proper blood flow to the new kidney. As a result the new kidney “suffocates” to death & is rejected.
Plasma Exchange Therapy can wash away problematic, hostile antibodies within the patient’s blood. So it may theoretically appear to be a treatment for hyperacute organ rejection in patients who develop this complication after their transplant surgery (not on table). However, clinically, hyperacute organ rejection is usually unresponsive to conservative treatments. So, such rejected donor kidney needs to be removed immediately. Please note, it is far too damaged to be put back into the donor and is duly discarded. (7)
Early post-operative period (0-7 days after the surgery)
During a kidney transplant, the donor kidney is attached to the patient’s urinary bladder via the donor kidney’s ureter remnant. Poor surgical technique or lack of optimum blood supply could weaken the surgical connection between the urine outlet pipe (ureter) of the donor kidney and the patient’s urinary bladder. This causes urine formed within the new kidney to leak out in the patient’s abdomen instead of flowing all the way to the recipient’s urinary bladder. Patients present with swelling of abdomen, pain, high drain output, sepsis & potential graft loss. It could also cause inflammation of the peritoneal tissue cover over intestines, which is painful and potentially fatal. Localizing the leak, quantifying urine loss & surgical repair of such urinary leak as soon as possible remain essential. (8,9)
HYPERACUTE REJECTION WITHIN 48 HOURS AFTER TRANSPLANT
Patients who develop this complication after waking up from their Transplant surgery (not on table) present with high fever, bodyache & malaise. There is sudden worsening of kidney function parameters like rise in Serum Creatinine. This could be because of antibody-mediated rejection where the patient’s immune system has had prior exposure and sensitization to donor antigens (identity proteins) in the past.For such patients, plasma exchange therapy may appeal as a non-surgical treatment option. This method can wash away the problematic, hostile antibodies within the patient’s blood. So theoretically it may appear to help.
However, clinically, hyperacute organ rejection is usually unresponsive to conservative treatments. So, such patients need to undergo an emergency surgery to remove the rejected donor kidney immediately and need to start dialysis for survival. Please note, such kidneys suffer significant damage. They cannot be put back into the donor and is duly discarded. (7)
ACUTE TUBULAR NECROSIS (ATN)
If the new kidney fails to receive proper blood supply after surgery, it may suffocate & perish due to insufficient oxygen. The technical name for this is Ischaemic acute tubular necrosis (ATN). Transplant patients may present with this complication within the first week of transplant. About 34%of kidneys from brain dead donors (cadaver donors) and about a tenth of living donor transplants may present with this complication. Such kidneys usually undergo acute rejection. But, please note that this is treatable and the donor kidney can be salvaged. (10)
FLUID BUILD-UP IN POCKETS AROUND THE TRANSPLANTED KIDNEY
Sometimes, blood, serum, lymph or pus from wound infection may collect in the space around the donor kidney. This can be confirmed with an ultrasound scan of the lower abdomen. The scan typically shows a white halo around the kidney as the image below shows.
During your hospital stay, transplant nurses would check for such collections regularly. Normally, the surgeon places a drainage tube in the patient’s belly to enable automatic removal of any fluid collection. Sometimes, fluid may collect after removal of the surgical drain. Then, fluid removal is possible using a syringe or a catheter drain. The fluid is sent for lab sampling to check for any infection and if present, the type of microbe. Accordingly, the patient is prescribed a course of anti-microbial to completely treat the collection and prevent graft loss.
KIDNEY GRAFT THROMBOSIS
Controlled thrombosis/ local blood clotting is a part of the natural healing process to sop any blood loss. Sometimes, this blood clotting process can go awry and become a cause for clinical concern. In terms of kidney transplant, there are various reasons as mentioned below, which can cause such excessive, uncontrolled blood clotting both in the artery and the vein of the donor kidney. Such clotting can ultimately damage the new kidney, cause heart attacks & strokes in the patient and could be potentially fatal unless there is a timely diagnosis.
RENAL ARTERY THROMBOSIS
Unintentional injury to the delicate lining of the renal artery due to surgical equipment
Wide variation in the width of the blood vessels of the donor kidney and the patient could make attaching the donor kidney tedious and trigger excessive clotting. This is preventable. An imaging test called Renal Doppler Scan before the transplant surgery in both donors and recipients can help identify these parameters beforehand.
Blood vessel kinking
Low blood pressure (Hypotension) in the patient
As an adverse effect of Cyclosporine – an anti-rejection medicine given to some patients
A cholesterol plaque fragment that may spontaneously come lose from the patient’s blood vessel wall and could mimic a blood clot
RENAL VEIN THROMBOSIS
This is a rare but life threatening complication. Factors that may trigger Renal Vein thrombosis include:
Dehydrated state in the patient
Faulty surgical technique
Deep vein thrombosis due to long-term lack of mobility. This is why medical teams encourage patients who are able, to resume walking or leg exercises as soon as possible after the transplant. For other critical patients, doctors prescribe compression stockings to prevent onset of this complication.
Fluid collection around the renal vein compressing it
Short term complications (1 week – 3 months)
ACUTE GRAFT REJECTION
The immune system of the patient may produce antibodies against the donor after the transplant within 1-3 weeks, despite all precautionary treatments. These could attack the donor kidney and cause acute rejection. If this happens, the patient will present with:
Flu-like symptoms: High fever above 100° F, Chills, Loss of appetite, Bodyache, Headache, Tiredness, Nausea, Vomiting, Diarrhea
Sudden weight gain (1-2 kg or 2-4 lbs in 24 hours)
Report to your medical team as soon as you get any such symptoms post transplant, especially in the earlier weeks.
With timely diagnosis, acute rejection may be treated to prevent complete graft loss.
The new kidney is attached to the urinary bladder for urine to flow out of the body. Because this is a surgical connection, there is scar tissue from healing of the wound. This could cause scar tissue buildup or excessive pulling-in of the delicate inner lining of the urine pipe (ureter) further inwards. These could narrow-down the ureter pipe and obstruct urine outflow.
Long term complications (3 months and beyond)
RENAL ARTERY STENOSIS
Stenosis is the technical term for pinching down or narrowing down of the flow-space within a blood vessel due to abnormal mechanisms. Post kidney transplant, this can happen because of the following:
Inadvertent injury to the delicate inner surface of the renal artery during surgery
Right beyond the site of connection of the renal artery of the donor kidney to the iliac artery of the patient
Cellular infiltrate due to acute rejection of the kidney
Cholesterol blockage of the patient’s Iliac artery onto which the transplant renal artery of the donor kidney is connected
This is the most common vascular complication after kidney transplant. It commonly occurs between the first 3 months to 2 years after kidney transplant. Patients would present with sudden uncontrolled high blood pressure, worsening of kidney function without any evidence of kidney rejection. Timely diagnosis of this condition is potentially treatable with medical therapy alone or in combination either with percutaneous transluminal angioplasty or surgical re-vascularization. (11)
CHRONIC ALLOGRAFT NEPHROPATHY
Chronic Allograft Nephropathy (CAN) is the technical term for chronic delayed rejection of the transplanted kidney. This is a gradual damage of the transplanted kidney over a few months to years after kidney transplant. The following factors increase the risk for onset of Chronic Allograft Nephropathy:
Kidney from a cadaver (brain dead) donor
Harvesting the kidney from a cadaver donor after 24 hours of brain death
Storing the harvested donor kidney in cold nutrient solution before transplantation beyond 24 hours
Injury of delicate inner lining of blood vessels in the donor kidney due to sudden restarting of warm blood circulation upon transplantation right after storing the donor kidney in cold nutrient solution after retrieval from the donor
Acute rejection episode(s) in the recipient after transplantation
Viral infection in the kidney recipient after transplantation
Tacrolimus (one of the anti-rejection medicines) toxicity
This complication is somewhat similar to getting chronic kidney disease in the transplanted kidney. Treatments can delay disease progression but are unable to reverse it. Unfortunately, CAN is a major cause for delayed kidney rejection & late graft loss.
Post kidney transplant, malignancy/cancer is a not too uncommon complication. Most commonly, post kidney transplant cancers are detected in the lymph tissue, skin or even in the transplanted kidney itself. (13)
Post kidney transplant, cancers could:
Occur as a side effect of Anti-rejection medicines
Surface as a recurrence in patients who have already had cancer before
Result from transfer of cancer cells from the donor kidney with prior undetected malignancy
The type of cancer affecting the transplant recipient and its clinical outcome varies with:
Where the patient resides
The specific immuno-suppressive medicine combination the patient is on
Chronic viral infections in the patient
Diagnostic practices & treatment protocols followed at the transplant center caring for the recipient.
The type of cancer and the stage of diagnosis as well as the quality of medical care received, determine the clinical outcome.
Regular follow-ups with the transplant team along with lab tests as necessary ,and go a long way in curbing this complication at an early stage.
INTRA-RENAL ARTERIO-VENOUS (AV) FISTULA
Arterio-venous fistula or AV fistula is a familiar term for all patients who have been on Haemodialysis. However, as opposed to planned AV fistula creation during dialysis, AV fistulae in the pathological sense are abnormal connections between an artery and a corresponding vein without an intervening capillary network. These could result either due to birth defects or aberrant instrumentation as part of medical procedures.
AV Fistuale seen after a kidney transplant are not a complication of the transplant procedure per se. Instead, they can occur as a result of injury from interventional medical procedures like biopsy of the transplanted kidney. Such AV fistulae usually crop up between the fine arteries and veins within the kidney tissue, hence called “Intra-renal AV Fistula”.
Patients with such AV Fistulae may present with sudden high blood pressure. Since these AV fistulae can rupture and cause bleeding within the kidney, the patient may also pass blood in urine (haematuria). Sometimes, however, these fistulae tend to produce no symptoms at all and a routine ultrasound scan of the transplanted kidney reveals this complication.
Whatever be the case, with timely diagnosis, this condition is potentially treatable with minimally invasive techniques like therapeutic embolization. Hence, routine follow up visits post kidney transplant are of the essence, especially if the kidney recipient has had to undergo any interventional medical procedure like a kidney biopsy.
TRANSPLANT RENAL ARTERY (TRA) PSEUDO-ANEURYSM
The word Aneurysm refers to abnormal localized bulging of a blood vessel as a result of pathological weakening of the blood vessel wall. However, injury to the delicate inner surface of a blood vessel (intimal injury) from instruments used during any interventional medical procedure could also weaken the blood vessel wall. Such weakened spots in a blood vessel are less able to withstand regular blood flow and may balloon out over time due to the blood pressure. Since this happens due to external injury and not from any disease, such blood vessel bulging is called False Aneurysm or Pseudo-aneurysm.
Transplant Renal Artery (TRA) Pseudo-aneurysm, as the name suggests, affects the renal artery feeding the donor kidney. Like intra-renal AV fistula, pseudo-aneurysm after kidney transplant is not a direct complication of the transplant procedure itself. Instead, it is more likely to result from injury of blood vessel wall due to surgical instruments or during interventional medical procedures like biopsy or arteriography of the transplanted kidney.
TRA Pseudoaneurysm is uncommon, but needs early, effective management to prevent any rupture, bleeding, infection, impediment to blood flow to the corresponding thigh or kidney graft loss. It can be treated without open surgery. Placing a stent combined with Expandable Hydrogel Coils under radiological guidance has proved to be a viable treatment option. (14)