Ch 119 Renal transplant Flashcards
List some factors associated with higher post-op morbidity/mortality
- Cats older than 10yo
- Creatinine over 10mg/dl (88μmol/L) and high BUN more likely to die before discharge
- Pre-op blood pressure and weight
- In dogs, every 1yr increase in age increases odds of death by 6m by 42%
What test is performed if a recipient cat has recently had a UTI or has a history of recurrent UTI?
A cyclosporine challenge test for 2 weeks
- If they have a positive culture result at end of test, they are eliminated as candidates
Can patients with positive toxoplasma titres be candidates for renal transplant?
Yes but they will need to be on clindamycin for life
List findings that eliminate a cat as a candidate for renal transplantation
What imaging is performed on potential kideny donors
CT angiography
What pre-operative medications can reduce the chances of requiring blood products?
Erythropoietin or darbepoietin
What are is the main immunosuppresive combon used in cats?
Prednisolone
Cyclosporine
How does cyclosporine work?
Inhibits calcineurin, thus preventing activation of transcription factors regulating genes for cytokines including TNFa, IL-2, IL-4, IFN-gamma and granulocyte-macrophage colony-stimulating factor
What can be added to the immunosuppressive protocol to be able to reduce the dose of cyclosporine?
Ketoconazole
- Itraconazole and clarithromycin may also be effective and have less adverse side effects
What kind of donor improves graft survival in dogs?
What is the most common immunosuppresive protocol?
A major-histocompatibility complex-identical littermate
Cyclosporine, prednisolone and azathioprine
What complications can be seen with ketoconazole in dogs?
Hepatotoxicity
Cataract formation
Addition of what substance to immunosuppresive protocol after transplantation from a nonrelated dog improves survival?
Rabbit antidog antithymocyte serum
Why is mannitol administerd during renal transplantation?
Minimise renal artery spasm
Improve renal blood flow
Protect against injury which may occur during the warm ischaemic period
What intra-op factors are assoc with overall decreased survival?
Hypotension
Prolonged anaesthesia over 6hr
Cats older than 12yo
Intraop hypoxaemia
What medication can be used to treat periop hypertension?
Hydralazine
Which kidney is preferred for transplantation?
Left kidney - longer vein
List the 2 methods of vascular anastomosis?
- anastomosed to recipient iliac vessels (12% hind limb complication rate)
- Renal artery anastomosed end-to-side to aorta using 8-0 nylon and renal vein anastomosed end-to-side to caudal vena cava using 7-0 silk
operating microscope with 5× to 22× magnification
After graft harvest, what solution is used for flushing?
Ice-cold phosphate buffered sucrose organ preserving solution
List the technique options for ureteroneocystostomy
Intravesicular
Extravesicular
- Ureter to bladder
- or can save a 2mm cuff of donor bladder around the donor ureter to use for anastomosis
What additional procedures may be performed at the time of surgery?
- Pexy kidney to abdominal wall
- Biopsy of one of the native kidneys
- Enteroplications in dogs (intussusception in up to 25% of dogs after renal transplantation)
What factors are assoc with increased risk of post-op seizures/neuro abnormalities
An increase of 1mg/dL serum creatinine or 10mg/dL BUN increases liklihood of post-op CNS disease by 1.8x and 1.6x respectively
If transplant is successful, how quickly should azotaemia resolve?
24-72hr
What is haemolytic uraemic syndrome?
A rare but fatal complication reported in cats
- Haemolytic anaemia
- Thrombocytopaenia
- Rapid deterioration of renal function secondary to glomerular and renal arteriolar platelet and fibrin thrombi
What is the prognosis following renal transplant in cats and dogs?
Cats:
- 70-92% discharged from hospital
- MST 360-613 days
Dogs:
MST 24 days in 26 dogs (range 0.5 - 4014)
List the most common post-op complications after renal transplant in cats
- Acute rejection 13-26%
- Chronic rejection
- Haemolytic uraemic syndrome
- Calcium ocalate urolithiasis
- Retroperitoneal fibrosis
- Ureteral obstruction
- Infection
- Diabetes mellitus 13.9% (5.45x more likely)
- Neoplasia 9.5 - 24%, lymphoma more common. 6.1-6.6x more likely to develop neoplasia
Characterization
of preoperative cardiovascular status and association with outcome following feline renal
allograft transplantation: 166 cases
Lillian Aronson 2022
Age was the only single significant variable associated with survival, and the risk of death increased by 11% (95% CI, 6% to 17%) for every 1 year in patient age.
CLINICAL RELEVANCE
The presence of cardiac abnormalities identified during the screening process of cats presenting for transplantation should not immediately exclude a potential candidate for the procedure. Owners considering transplantation should be educated on the impact of age on survival following surgery.
Retroperitoneal fibrosis as a
postoperative complication
following renal transplantation
in cats
Brittney J Byer 2022
Results Eighty-one cats underwent 83 renal transplantations, six developed clinically significant
RPF (7%)
Surgical
examination revealed a layer of dense fibrous tissue surrounding the transplanted kidney, ureter and bladder resulting in ureteral obstruction
Ureteral obstruction was managed by reimplantation of the proximal ureter or renal
pelvis to the bladder
Of the six cats, two died within 5 days after revision surgery, two developed signs
consistent with recurrent partial ureteral obstruction (40 and 41 days after revision), one was euthanized 6 years
Evaluation of a microvascular anastomotic coupler
for end-to-side arterial and venous anastomosis for feline
renal transplantation
Megan A. Mickelson 2021
feasibility of an endto-
side (ETS) anastomosis of the renal vein to vena cava and renal artery to
aorta using a microvascular anastomotic coupler (MAC) for feline renal
transplantation.
Study design: In vivo experimental study.
Animals: Six purpose-bred domestic shorthair cats.
End-to-side anastomosis of the renal vein and artery to the vena
cava and aorta, respectively, was consistently achieved in all six cats with
the MAC.
Clinical significance: The use of the MAC may be considered as an alternative
to hand suturing for ETS anastomoses for feline renal transplantation.
