review of renal transplantation surgery and its complications for nephrologists

1. Mahmoud Naguib

2. Cadaveric donor
•Donation after brain death (DBD)
Systemic perfusion is maintained, and ischemic injury is minimized
•Donation after cardiac death (DCD)
involves donors who are not brain-dead, but in whom treatment is withdrawn, as there
is no prospect of recovery.
Associated with more warm ischemia time.
Living donor

3. Warm ischemic time
period between circulatory arrest and start of cold
storage.
It is extremely injurious to the kidney.
Cold ischemic time
period of cold storage before transplantation.

4. Living donor transplantation is the treatment of choice for ESRD
Can be related or unrelated donor
Advantages:
•Better graft and patient survival
•Easier Pre-emptive transplant which has the best outcome
•Closer HLA matching may be possible
•Live donor transplantation expands the overall donor pool — leaving deceased donor
kidneys for those with no other options
•Minimal ischaemic damage to graft (less DGF)
•Possible less immunosupression

5. Disadvantages:
•Perioperative donor mortality is around 1 in 3,000 (causes:
occult cardiac disease, venous thromboembolism).
•Major complications occur in around 2% (intraoperative
bleeding, wound problems, DVT)
•Minor complications occur in 20%
•Stress to donor (and family)
•Later development of donor hypertension, proteinuria, or CKD
•Difficult to guarantee ‘ freely given ’ consent

7.  The kidneys are perfused with a cooled balanced
physiological solution in situ before removal.
 Nephrectomy can be done by open incision or
laparoscopic
 Laparoscopic nephrectomy has shorter incisions, less
pain, shorter hospital stay, shorter recovery, better
cosmetic appearance
 Along with the kidney, the renal artery, the renal
vein(s), and as much ureter as possible (with
periureteral tissue — to preserve its vascular supply)
are removed.

8. Machine pulsetile perfusion techniques
Cold storage:

9.  The kidney is carefully examined, paying attention to the vascular anatomy:
-accessory arteries cannot be sacrificed, as there is no collateral supply
-The left renal vein is longer, making it easier to implant
 Graft implantation is heterotopic, usually into the right iliac fossa (the right iliac
vessels are generally more accessible), although some surgeons favor placing a
right donor kidney on the left side and vice versa (as kidney orientation is easier)
If a previous transplant remains in situ, the contralateral side will be favored.
 An oblique incision is made from above the symphysis pubis towards the anterior
superior iliac spine
 The operation is largely extraperitoneal.
 The native kidneys usually are not removed

10.  Vascular anastomoses are usually end-to-side to the external iliac vessels
 End to end anastomosis with the internal iliac artery can be done but may lead to
erectile dysfunction in males.

11.  The ureter is joined to the recipient bladder.
A submucosal tunnel helps to prevent urine
reflux.
 A JJ stent is usually placed to protect this
anastomosis (removed by cystoscope at 74
weeks).
 A urethral catheter is left in situ for 5 days.
 A drain is usually left in the perirenal space.

13.  Wound Infection
The use of preoperative prophylactic antibiotics, commonly amoxicillin– clavulanic
acid, has reduced the incidence of wound infection to < 1%.
If a wound infection does occur, treatment is with antibiotics, guided by microbiologic
wound swabs, and drainage of collections as necessary.
 Wound Dehiscence
The risk for wound dehiscence is increased in obese & diabetic patients & with
mTORIs
Treatment of any infection is mandatory.
Resuturing of the wound is rarely justified.
Large areas of dehiscence often benefit from vacuum-assisted closure, but the majority
require only frequent dressing.

15.  Bleeding From Vessels in the Renal Hilum
Unsecured small vessels in the renal hilum may not be obvious during surgery,
but they may start bleeding postoperatively → blood loss is slow & persistent:
Careful postoperative observation.
Regular CBC.
Output from the transplant drains.
Urgent imaging US or CT.
Are crucial for the early detection of bleeding which may need urgent exploration

16.  Anastomotic Hemorrhage
Caused by a technical surgical error
more common with multiple arteries and the use of antiplatelet agents
Manifestations:
Postoperative pain over the graft or may be pain in the back or the rectum caused by a
tension hematoma in the retroperitoneum or pelvis.
Significant hemorrhage → lead to circulatory collapse with tachycardia and hypotension
Management:
The patient must be returned to the operating room immediately for re-exploration
Hemorrhage also can occur some weeks after transplantation because of the
development of a mycotic aneurysm of the renal artery. In the rare case of a
ruptured mycotic aneurysm, an immediate graft nephrectomy is required, but the
mortality is high.

17. Transplant vascular thrombosis is a serious complication that may cause early
and irreversible graft failure
Although there are also significant hemorrhagic risks, routine perioperative
prophylaxis with LMWH is mandatory and some units prescribe aspirin for the
first few postoperative months
1) Renal artery thrombosis:
A rare event < 1% of transplants → leading to loss of the kidney
Acute arterial thrombosis may occur intraoperatively or during the first days or
weeks after transplantation

18. Possible causes:
Hyperacute rejection.
Procoagulant state.
Technical error during the anastomosis.
Atherosclerosis, diabetes, persistent hypotension & volume depletion.
Manifests with sudden anuria
Deferential diagnosis
Blocked urinary catheter.
Dehydration.
ATN.
Urologic complication.

19. Investigation
Urgent duplex
Can proceed directly to exploration
Management
Acutely thrombosed grafts must be explored and removed
to avoid the development of sepsis in a necrotic graft, a
potentially fatal complication

20. Renal vein thrombosis is more common than arterial thrombosis (1% to 6%).
The peak incidence of renal vein thrombosis is 3 to 9 days after transplantation
Possible cause
Technical error at the time of surgery.
Manifestations:
Oliguria which is often markedly blood stained or sudden anuria.
Severe pain arising from swelling and (very rarely) rupture of the allograft.
The ipsilateral leg may swell if there is involvement of the iliac venous system.
One differential diagnosis of delayed graft function

21. Management:
Investigation
urgent duplex ultrasound scan showing swollen allograft with surrounding
hematoma and an absence of renal perfusion.
The best course of action is to reexplore the transplant as an emergency:
 The renal vein anastomosis can be opened to allow clot to be extracted.
 A more radical alternative is to immediately explant the kidney which is reflushed with
cold perfusion fluid on the back table and held in preservation fluid at 4° C → this
allows much more time to assess the cause of the venous thrombosis.
 Interventional radiographic techniques → the renal vein can be selectively catheterized
via the ipsilateral femoral vein, then graft thrombolysis.

22. Late complication occurring 3 to 48 months after transplantation
Not all stenoses are of functional or clinical significance
Possible causes
Technical error at the time of surgery.
Donor and recipient atherosclerosis
Severe acute rejection
Manifestations:
New onset or worsening hypertension.
Renal impairment may also occur
Renal artery bruit can be heard over the allograft

23. Management:
Investigations
Renal duplex ultrasound is the initial screening test
MR angiography provides excellent anatomic definition of the transplant RA
CT angiography is comparable to renal arteriography but requires more contrast
Carbon dioxide angiography can allow visualization and successful treatment using as little
as 9 mL of iodinated contrast
Percutaneous renal artery angioplasty with or without stenting is the initial approach:
 Success rates: 90% for technical outcomes and 66% to 94% for clinical outcomes (BP, renal function)
 Complication rate: 9.9% including vessel dissection, thrombosis, and site hematoma
Surgical renal revascularization of allografts is difficult and associated with high
complication rates
 Long-term outcomes of treated graft RA stenosis are equal to those without RA stenosis

24. Small insignificant lymphatic collections occur in up to 50% of renal transplants.
Larger lymphoceles that cause complications or require treatment occur in 2-10%.
Prevention:
The source of peri-transplant lymph leaks is the lymphatic channels of the iliac arterial
system rather than the lymphatics of the transplanted kidney itself → Therefore, all the
surrounding lymphatic channels of the iliac arterial system must be meticulously
secured with nonabsorbable sutures.
Wound suction drains should not be removed postoperatively until less than 30 ml of
fluid is produced on 2 consecutive days
Manifestations:
Majority are asymptomatic and manifest as an incidental finding during US
scan.
Compression of the transplanted ureter leading to graft dysfunction & fever.
Urinary frequency caused by bladder compression.
Wound swelling or ipsilateral thigh swelling.
Pain over the transplanted kidney.

25. Management:
Graft ultrasound
If surgery is indicated, Preoperative CT or MRI allows accurate definition of the
relationship between the lymphocele and the transplanted ureter.
Many small lymphoceles are asymptomatic and will resolve spontaneously given
enough time.
Aspiration under US → followed by biochemical analysis to exclude urinary leak
& differentiate infected from non-infected lymph.
If there is a recurrence, further aspirations can be performed, or an external drain
can be placed.
Open or laparoscopic surgical drainage may be required.
Investigations:

27. Presentation:
Due to ischemic necrosis in any part of the urinary collecting system especially the
distal ureter which has the poorest blood supply and is therefore the most common
site.
Due to unrecognized direct damage to the ureter (midportion or renal pelvis)
during organ retrieval.
Tend to occur in the first few days after transplantation.
Straw-colored fluid leaking directly from the transplant wound or accumulating in
the drains in association with oliguria.
Painful swelling of the wound with fever.
Peri-transplant fluid collection by US which is aspirated to be differentiated from
lymphocele by measuring Creatinine in it.
Cause & site:

28. Management:
The presence of a urinary fistula should be confirmed by antegrade or retrograde
pyelography:
Antegrade puncture of a non-dilated pelvicalyceal system is technically difficult.
Retrograde pyelography of the transplanted ureter is done by flexible cystoscope & is difficult as
the ureter is implanted into the dome of the bladder rather than at its base.
Ultrasound will demonstrate a fluid collection between the transplanted kidney and the bladder.
Needle aspiration or tube drain.
Early re-exploration and surgical reconstruction is no longer always necessary.
Placing double-J ureteral stent across the region of damage via an antegrade
nephrostomy; this may allow time for the urinary fistula to heal.
This technique (JJ) is unlikely to be successful if there is significant ischemic necrosis of
the ureter, in this case, surgery still has a role → the transplanted ureter may simply be
reimplanted into the bladder after excision of the necrotic part Or if the ureter is short →
can be reconstructed with use of the patient’s native ureter or Boari flap.
Investigations:

30. Presentation:
Obstruction of the transplanted ureter may occur at any time after transplantation.
Early obstruction due to:
 Technical error (too tight submucosal bladder tunnel, kinked ureter or incorrect suture
placement during anastomosis).
 Blood clot in the ureter, bladder or catheter → it is common practice to drain the urinary
bladder using a three-way irrigating catheter because small-diameter two-way Foley
catheters are easily blocked by blood clot.
Late ureteral obstruction due to:
 Ischemia that is not severe enough to cause necrosis.
 Renal transplants may excite a peri-graft fibrotic response → mostly causing obstruction at
the pelvi-ureteral junction.
 Acute rejection episodes may contribute to subsequent fibrosis.
 BK polyoma virus because of hypertrophy of ureteric epithelial cells in combination with
infiltration of inflammatory cells.
Should be considered in the differential diagnosis of acute graft dysfunction
Causes:

31. Management:
Ultrasound scan demonstrating a dilated pelvicaliceal system.
Retrograde pyelography.
PCN followed by antegrade pyelography is the investigation of choice.
The nephrostomy tube should be left in place for a few days. If serum creatinine decreases
during this period, obstruction is confirmed, but if there is no improvement in renal
function, significant obstruction can be excluded.
Place a double- J stent across the stricture via a PCN & the stent can be removed after 6
weeks, but restenosis rate is high.
An alternative is long-term stenting, changing the stent every 6 months → the
disadvantage of this method is a high incidence of UTI.
Open surgical management → the operation performed depends on the site of obstruction
and remaining length of healthy transplanted ureter proximal to the obstruction.
Investigations:

33.  The lateral femoral cutaneous nerve, femoral, obturator and sacral
nerve may be encountered in the retroperitoneal dissection required
for kidney transplantation → may be damaged by a traction injury→
Patients with such neurapraxias should recover completely.
 The spermatic cord must be mobilized during the dissection to gain
access to the retroperitoneal space → may lead to damage to the
testicular artery in the cord can result in testicular atrophy

34.  Early graft failure caused by vascular thrombosis.
 Capsular rupture.
 Irreversible rejection.
 The options are transplant nephrectomy or leaving the graft in situ with or without
immunosuppression.
 Patients with failed grafts continuing immunosuppression → showed higher mortality from both
infection and cardiovascular disease.
 Patients discontinued immunosuppression → showed increased risk for graft intolerance, transplant
nephrectomy and allo-sensitization.
 Signs and symptoms of graft intolerance such as pain, fever, hematuria, and thrombocytopenia may
require transplant nephrectomy, although can be treated initially with corticosteroids.
Transplant nephrectomy is mandatory for:
Nephrectomy of chronically failed graft is more challenging:

35.  Transplant nephrectomy was advocated to remove antigenic stimulation for (anti-
HLA) antibody production, which might adversely affect the possibility of re-
transplantation.
 However, there is some evidence that transplant nephrectomy may actually
increases allo-sensitization as the graft may act as an “immunologic sponge” to
absorb antibody or may regulate the production of anti-donor antibody by the
recipient’s immune system.
 Graft nephrectomy after the first few weeks is difficult → because kidney
transplants usually develop peri-graft fibrosis.
 A subcapsular dissection is preferred, and after removal of the kidney, the hilum is
sutured, leaving a cuff of donor vessels in place. Careful hemostasis is required,
and the whole raw capsular bed should be cauterized.
Surgical procedure:

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