119. renal transplant Flashcards
outcome of renal transplant cases according to Schmeidt et al vet Surgery 2008
78% survive to dischargeMST 600 days6 mo survival 65%3 yr survival 40%
indications for renal transplant
end stage chronic renal failurechronic interstitial nephritisrenal dysplasiaethylene glycol toxicity (transplant after dialysis)glomerulonephropathypolycystic kidney diseaseamyloidosis*pyelonephritis**unsure if appropriate candidates
screening of a potential renal transplant candidate
–MDB –Blood type—major and minor cross match to donor–thyroid hormone–UA ,culture–UPC–Ab rads and US–thoracic rads—BP–echocardiography–FeLV/FIV–toxoplasma titers (IgG, IgM)must rule out infection, neoplasia and/or obstruction!
age as a risk factor of mortality following discharge from hospital
–cats older >10 yr had great mortality (esp in first 6 mo post op)–MST decreased with increasing age
azotemia as a risk factor
azotemia with Cr> 10 were more likely to die before dischargein another study, severity of azotemia was NOT related to mortality but increased the risk of neurologic complications in the peri-operative period
protocol if patient suffers from recurrent UTIs
can only transplant with negative culture.at time of negative culture, start 2 week cyclosporine test and recheck urineif it grows negative at that time, transplant can be donepositive culture eliminates the candidate for transplant
findings that preclude renal transplant
–neoplasia–CHF–FeLV +–active FIV infection–recurrent/existing UTI (fails cyclosporin challenge)–uncontrolled hyperthyroidism–fractious temperamentmany grey areas (IBD, cardiomyopathy, diabetes)
are seropositive toxoplasma cats denied transplant?
nobut require lifelong clindamycin or TMS therapy(started pre-op)sensitivity of the test may not be the most accurate
evaluation of renal donors
1-3 YOexcellent healthscreening excellent (labs, urine, radiography, cardiovasclular, and infectious)CT angiogram to eval vasculature and parenchymal abnormalities (exclude donors that have infarcts, multiple vessel anomalies)donor gets adopted
how is routine compatibility of donor and recipient addressed
blood typingmajor and minor cross matching
study evaluating the outcome of unilateral nephrectomy in donor cats
15/16 cats were normal for follow up 24-67 mo (one cat was diagnosed with chronic renal insufficiency 52 months post)all dogs remained healthy within 2.5 yr followuplife long screening is recommended expected to have a normal life expectancy
preoperative preparation of recipient
–preoperative hemodialysis if severe azotemia–IVF–Ca channel blocker therapy (amlodipine) if hypertensive–EPO therapy if transplant is delayed (can make Ab against)–correct pre existing anemia if indicated (whole blood, pRBC)–immunosuppression 4-5 days before surgery (cyclosporine–Neoral and prednisolone in cats ; azathioprine, cyclosporine in dogs +/- ketoconazole)–test cyclosporine concentrations pre-op–at induction, whole blood from donor given to recipient –consider feeding tube
MOA of cyclosporine
Blocks calcineurindecrease activation of transcription factors necessary to make cytokines (TNF alpha, IL 2 IFN gamma, granulocyte-macrophage colony stimulating factor) which play a role in graft rejection
purpose of mannitol given IV to donor cat
mannitol given to donor cat at time of abdominal incision and right before nephrectomy (+/- to recipient after anastomosis)to promote perfusion to kidney
renal artery length recommendation from donor
0.5 cm length (minimum)single renal artery
which kidney is preferred from the donor and why
LEFT kidneylonger vein
2 methods of vascular anastomoses for renal vasculature
—donor renal vessels to recipient ext iliac vessels (end to end)—–12% cats pelvic limb probs—donor renal vessels end to side with Aorta (proximal to cd mesenteric br) and Cd Cava 2 simple continuous patterns 8-0 nylon aorta 7-0 silk cava
what is graft flushed with after harvested
phosphate buffered sucrose preservation solution
T/Fvenous clamp is removed prior to arterial clamp after anastomosis is done
TRUE
treat vascular spasms
topical lidocaine or acepromazine
when simultaneous donor and recipient surgeries can not happen, what preserves the harvested graft kidney
hypothermic storage while sitting in phosphate buffered sucrose preservation solution
three techniques for ureteroneocystostomy (ureteral reimplantation)
- extravehicular2. intravesicular mucosal apposition (ventral cystotomy)3. extravesicular technique with harvested ureter and ureteral papilla
what needs to be done to minimize renal torsion
NEPHROPEXY the allograft
two commonly reported complications following renal transplant in dogs
intussusception (consider enteroplication)immunosuppression (leaking to sepsis)
CNS dysfunction and seizures in post op feline transplant patients was related to what parameter
post op hypertensionadministration of antihypertensive therapy (amlodipine PO or hydrazaline SQ) significantly decreased risk seizure and MM associated with neuro complications
at what point does azotemia start to improve following renal transplant
24-72 hr post opif no improvement seen—ab US is warranted
patient follow up recommendations
once a week for the first 6-8 weeksthen monthly for 6 monthsthen every 2-3 month visitsTPR, BP, CBC/Chem/UA, PCV/TP, body weight, cyclosporine concentrations
rare but lethal side effect of cyclosporin therapy
hemolytic uremic syndromehemolytic anemia, thrombocytopenia, rapid deterioration in renal fx
list post op complications with renal transplant in cats
Acute rejectionchronic rejectionhemolytic uremic syndrome (cyclosporin tx)Ca oxalate uroliths retroperitoneal fibrosisureteral obstruction————-ALL THE ABOVE LEAD TO RENAL DYSFUNCTIONseizures (esp if hypertensive post op)
list 3 complications associated with aggressive immunosuppression
Infection (sepsis or reactivate Toxoplasma)diabetes mellitus (5.5 x more likely in renal transplant patient)cancer (transplant and cyclosporin tx risk 6x for development of cancer)
