Renal Transplant Flashcards
Indications for Renal Transplant
Contraindications to Renal Txp
Evaluation for transplant recipient workup, labs, imaging, additional tests?
HCG (F < 50 yo)
CBC
PT/PTT
UA
Urine protein/creatinine
CMV
EBV
Varicella Zoster
Hep b
Hep C
HIV
Syphilis
Quantiferon Gold Tb or PPD
ABO type and antibody type (prior to sx)
Baseline CT A/P or US (non-contrast outlines calcifications in vessels)
Cardiac screening (EKG)
Dobutamine Stress test when > 3 risk factors (>60 yo , smoking, HTN, HLD< DMII, prior CVD, > 1 year on dialysis, LVH)\
Malignancy evaluation (5 year wait for invasive/mets, 1 year localized/low grade)
GU evaluation prior to txp:
Evaluate voiding dysfunction: prostate scores, prostate US, UDS (not routine)
VUR → VCUG
CIC teaching
Asx urolithiasis generally not contraindication, may be risk for pyelo
Infective stones tx prior to txp
In renal txp with recurrent UTI or systemic symptoms, what is part of workup? DDx?
BK virus (can reduce immunosuppression), viruia, bacteria
anatomic assessment important
Uroflow/PVR
UDS
US or CT (obstruction, abscess, stones, cysts)
VCUG (if suspect VUR)
Risks of malignancy with immunosuppression?
Yes increased skin, lymphoma, kidney, bladder
ACKD → RCC (slight papillary predominance)
Why is kidney preservation necessary? How is it done?
Cold storage
Pulsatile preservation pump (reduce vascular spasm, extend preservation time, reduce need for HD of txp)
Renal tubular Na-K pump maintains high intracellular K dependent on ATP
Ischemia leads to depletion of ATP, loss of cellular K and Mg, increased Ca, anaerobic glycolysis and acidosis, activation of enzymes
Reperfusion, hypoxanthine (a product of ATP) → xanthine → free radicals and cell damage
What is ABO compatibility? Histocompatibility?
ABO blood groups are determined by cell surface carbohydrates on RBCs
Human major histocompatibility complex is a cluster of more than 200 genes on chromosome 6p21.31 responsible for HLA that are expressed as surface proteins on renal allograft
(most txp have some mismatch)
Discuss HLA classification:
HLA Class 1: expressed on nucleated cells HLA-A and HLA-B, class I antigens (as well as HLA-C) present endogenous antigens to cytotoxic T-cells
HLA Class II: expressed on cells of immune system
HLA-DR is class II antigen (aw well as HLA-DQ and HLA-DP)
Present antigen to helper T-cells
Live donor evaluations:
Healthy adults > 18 yo
no predisposing factors for CKD
w/o substance abuse or psych disorders
Normal surveillance screening (colonoscopy, PSA, mammogram, EKG)
Contrasted CT (size, shape, anatomic anomalies, number, length, location of arteries and veins)
Better kidney
Left with longer vein
Take kidney with fewer arteries
What can you get HLA antibodies from?
prior blood txf, transplants, pregnancy
Living donor operation key points:
low complication rate
hand-assisted Lap, full lap, robot (open rare)
ureter mobilized to point of crossing iliac
renal vessels ligated with stapler
extracted and placed in basin with iced saline
renal arteries cannulated
kidney flushed with ice-cold heparinized LR
Indications for pre-txp Nx? Timeframe?
chronic or recurrent acute bacteria pyelo
infected stones
heavy proteinuria
intractable HTN
PCKD with markedly enlarged kidneys
infected reflux
renal cystic dz with concern of malignancy
6 weeks prior to Txp
Significance of small bladder capacity in txp recipient?
Fibrosis or poor compliance may need pre-txp augment
small bladders may develop normal capacity and compliance post-txp unless fibrosis
Describe Hand-Assist Lap Donor Nx:
- NGT/Foley
- Lateral (donor side up)
- Camera trochar, additional under visualization
- Introduce hand port through lower midline
- Left Nx: mobilize descending colon, dissect ureter, open Gerota’s, dissect renal artery and vein, ligate adrenal vein and gonadal vein
- Right Nx: mobilize ascending colon, dissect ureter, open Gerota’s, dissect renal artery and vein
- Clip and cut ureter, staple artery and vein
- Remove kidney via hand port
- Flush with cold heparinized fluid
- Check for bleeding
- Close
How do you manage 2 renal arteries
side-to-side anastomosis (“pair of pants”)
on back table (txp surgeon)
For short allograft ureters, what are options:
Psoas hitch
Boari
Native UU
Native ureteropyelostomy
Pyelovesicostomy
Ileal ureter
Post op transplant recipient care:
UOP
change in GFR
Electrolytes
CBC
Foley 3 days or longer
Hydration
Advance diet in 1- days (extraperitoneal)
US (if suspicion of vascular compromise)
Immunosuppression 3 stages:
Work in synergy
Induction (lymphocyte depleting Ab or non-depleting Ab)
IV within 1 week of txp (Basiliximab)
Maintenance
3 categories (synergy) orally a few days after txp
Calcineurin-Inhibitor (tacrolimus, cyclosporin)
Antiproliferative agent (mycophenolic acid, azathioprine)
Co-stimulator blockade (Belatecept) MTOR (Sirolimus, Everolimus)
Corticosteroids (Prednisone)
Therapy for rejection
Rejection is lymphocyte mediated, can have Ab component
Corticosteroids
Lymphocyte depleting agents
If also Ab mediated (IVIG, Rituximab Bortezomib, Eculizumab, Plasmapheresis)
types of rejection for kidney txp:
- Hyperacute: immediately after revascularization due to pre-formed Ab → nx is required
- Acute rejection: weeks to months, before sxs, dec UOP and elevated Cr, confirm renal bx, cellular or Ab mediated (classification system)
- Chronic rejection (chronic allograph nephropathy): years, gradual decline in fx, bx → minimal mononuclear cell infiltration, fibrosis, vascular changes
Complications following Renal Txp:
Immediate vascular: impair perfusion to kidney or distal extremity
Restoration may require intimal flap repair, dissection, thrombectomy, bypass
Late RAS restored via angioplasty/stent
Fistula (calyceal-cutenous) or stricture
Necrosis of distal ureter at implantation site
Decline UOP, rising Cr, pain, swelling, leakage from incision
May require revision
Strictures (ischemia) → hydro, endourologic vs. redo anastomosis
Lymphocele (common)
Hydro, obstruction, iliac vein compression, DVT
IR drain, OR drain
AUR BPH (alpha blocker, 5ARI, sx - delay 1-2 mo)
Microhematuria
likely to be expected for 6 mo
after that time standard eval
Obstructing stones in allograft
PCN (with urosepsis or AKI)
4-5 mm conservative if GFR ok
Flexible URS superior to semi-rigid
1.5 cm PCNL (NO ESWL)
Medical Complications after Renal Txp:
Infections
Opportunistic
Viral → BK, CMV, EBC, HSV, Hep B/C
Bacterial → nocardia, listeria, Tb
Fungal → pneumocystis, aspergillus, cryptococcus
Parasitic → strongyloides, toxoplasma, leishmania, trypanosoma
Immunosuppression can be reduced if graft function stable
Life threatening infection → stop immunosuppression
COVID 19
UTI
Cancer
Skin cancer (SCC and basal cell, melanoma)
Lympoma/Leukemia
Kaposi’s sarcoma
Uterus/Cervix
Angogenital
Renal
Nephrotoxicity, HTN, DMII, Neurotoxicity
GI (diarrhea, n/v)
Bone marrow suppression
Osteoporosis
Cataracts
Immunosuppressant and side effects
25 yo F with IDDM s/p renal txp in right iliac fossa, on cyclosporine, mycophenolate, prednisone, with fever 1-2 and pain, 3 days after txp, decreased UOP, what labs? Imaging?
Labs:
UA, UCx
CBC
BMP
Cyclosporine
Imaging:
KUB (stent) Renal US (fluid, doppler)
Ddx of perinephric fluid collection and decreased UOP days after txp? Test? Tx?
Hemorrhage from arterial or venous anastomosis
Urinoma
Lymphocele
Put IR drain, send fluid
Cr
Culture/Stain
KOH (fungus)
CT cystogram or Contrast CT
Antegrade imaging via PCN (if not apparent)
Tx:
small leaks → foley +/- PCN or stent
persistent or large → anastomotic revision
type of of ureteral anastomotic revision for txp kidney if necrosis, leakage?
Reimplantation
Ureteropyelostomy to native ureter, nx of native kidney (planned)
Ureteroureterostomy to native ureter
Boari flap
Vesicopyelostomy (anastomosis with renal pelvis of txp)
Veiscocalycostomy
Ileal Ureter
What is the most cost-effective treatment for patients with end-stage renal disease?
a) Dialysis
b) Kidney transplantation
c) Chemotherapy
d) Radiation therapy
b) Kidney transplantation. Renal transplantation is the most cost-effective treatment for patients with end-stage renal disease and improves their chances of survival and their quality of life.
What is the range of overall rates for urologic complications after renal transplantation?
a) 2-3%
b) 4-5%
c) 6-7%
d) 8-9.5%
d) 8-9.5%. Overall rates of urologic complications after renal transplantation range between 8% and 9.5%.
What is the most common cause of urologic complications after renal transplantation?
a) Transplanted kidney
b) Transplanted ureter and ureterovesical anastomosis
c) Donor kidney
d) Donor ureter
b) Transplanted ureter and ureterovesical anastomosis. The majority of the urologic complications after renal transplantation are related to the transplanted ureter and ureterovesical anastomosis.
Why is prompt management of urologic complications important after renal transplantation?
a) To improve graft function
b) To prevent deterioration of graft function
c) To improve graft survival
d) All of the above
d) All of the above. Prompt management of urologic complications after renal transplantation is important to prevent deterioration of graft function, improve graft function, and improve graft survival.
Which medical specialty is responsible for managing urologic complications after renal transplantation?
a) Cardiology
b) Urology
c) Oncology
d) Dermatology
b) Urology. Urologic complications after renal transplantation are the most common surgical adverse event, and the goal of this chapter is to help the urologist manage these complications.
What is hematuria typically related to during the immediate postoperative period after a renal transplant?
a) Arteriovenous collecting system fistula
b) Donor kidney
c) Ureterovesical anastomosis
d) BK virus
c) Ureterovesical anastomosis. Hematuria during the immediate postoperative period after a renal transplant is typically related to the ureterovesical anastomosis.
In what percentage of cases do arteriovenous collecting system fistulas tend to resolve spontaneously?
a) 20%
b) 50%
c) 70%
d) 90%
c) 70%. In 70% of cases, arteriovenous collecting system fistulas tend to resolve spontaneously.
How is the diagnosis of an arteriovenous collecting system fistula confirmed?
a) Duplex ultrasound
b) Magnetic resonance imaging
c) Computed tomography
d) X-ray
a) Duplex ultrasound. The diagnosis of an arteriovenous collecting system fistula can be established by duplex ultrasound, which can be confirmed by magnetic resonance angiography.
What is the biggest difference in evaluating asymptomatic microscopic hematuria in transplant recipients compared to non-transplant patients?
a) The causes of hematuria
b) The type of diagnostic tests used
c) The duration of observation
d) The location of the hematuria
a) The causes of hematuria. The evaluation of asymptomatic microscopic hematuria (AMH) in transplant recipients follows the American Urology Association guidelines for AMH, with the biggest difference being the addition of BK virus as part of the differential diagnosis.
How is BK virus suspected and confirmed as a cause of asymptomatic microscopic hematuria in transplant recipients?
a) By viral cytopathic changes seen on cytology and confirmed by urine BK virus titers
b) By performing a biopsy of the transplanted kidney
c) By performing a duplex ultrasound
d) By performing a magnetic resonance angiography
a) By viral cytopathic changes seen on cytology and confirmed by urine BK virus titers. BK virus as a cause of asymptomatic microscopic hematuria in transplant recipients may be suspected by viral cytopathic changes seen on cytology and confirmed by urine BK virus titers.
What is the utility of a ureteral stent across the ureterovesical anastomosis during renal transplantation?
a) To increase the incidence of urine leak
b) To decrease the incidence of urine leak and stricture of the ureter
c) To increase the risk of bacterial colonization
d) To decrease the risk of graft infection and graft failure
b) To decrease the incidence of urine leak and stricture of the ureter. Several randomized clinical trials confirmed the utility of the routine use of a ureteral stent across the ureterovesical anastomosis during renal transplantation to decrease the incidence of urine leak and stricture of the ureter.
What is the risk of bacterial colonization associated with ureteral stent insertion?
a) 10%
b) 27%
c) 50%
d) 70%
b) 27%. Ureteral stent insertion is associated with an intrinsic risk of bacterial colonization, with 27% of the ureteral stents being colonized regardless of the indwelling time.
What is the risk of graft infection and graft failure associated with subsequent urinary tract infection after ureteral stent insertion?
a) Low
b) Moderate
c) High
d) Very high
c) High. Subsequent urinary tract infection (UTI) after ureteral stent insertion may pose a significant risk for graft infection and graft failure.
According to a recent meta-analysis, what is the effect of early stent removal on the incidence of urinary tract infection?
a) Increases the incidence of UTI
b) Has no effect on the incidence of UTI
c) Reduces the incidence of UTI
d) Eliminates the risk of UTI
c) Reduces the incidence of UTI. Early stent removal, defined by removal of the stent before the third postoperative week (before day 15), has been shown to reduce the incidence of UTI without discernible effect on the incidence of urine leak and stenosis.
What factors should be taken into consideration for the timing of stent removal for every patient after renal transplantation?
a) Surgeon satisfaction with the anastomosis and the patient’s related risk factors such as diabetes, transplant revision, and presence of UTI.
b) Patient’s age and sex
c) Blood type compatibility with the donor
d) Number of previous transplants
a) Surgeon satisfaction with the anastomosis and the patient’s related risk factors such as diabetes, transplant revision, and presence of UTI. A case-by-case approach to the timing of stent removal for every patient must take into consideration surgeon satisfaction with the anastomosis and the patient’s related risk factors such as diabetes, transplant revision, and presence of UTI.
What is the cause of a retained stent after a ureteroneocystostomy closure during renal transplantation?
a) Stent encrustation
b) Bacterial colonization
c) Technical error during the anastomosis suture
d) Kidney denervation
c) Technical error during the anastomosis suture. A retained stent can be due to a technical error during the ureteroneocystostomy closure in which the anastomosis suture inadvertently has caught the stent.
What is stent encrustation, and how common is it?
a) The growth of bacteria on the surface of the stent; it occurs in 90% of patients
b) The accumulation of minerals on the surface of the stent; it occurs in 5-10% of patients
c) The rupture of the stent; it occurs in 2-3% of patients
d) The migration of the stent; it occurs in 15-20% of patients
b) The accumulation of minerals on the surface of the stent; it occurs in 5-10% of patients. Stent encrustation is the accumulation of minerals on the surface of the stent, and its incidence ranges from 0 to 5.7%.
Why do kidney transplant recipients rarely manifest the classical symptoms of ureteral obstruction?
a) Because they have a higher pain tolerance
b) Because they have a lower sensitivity to urinary tract infections
c) Because of renal allograft denervation
d) Because of their overall better health status
c) Because of renal allograft denervation. Kidney transplant recipients rarely manifest the classical symptoms of ureteral obstruction because of renal allograft denervation.
What symptoms does a transplant recipient with an encrusted stent usually present with?
a) A rapid increase in urine output and decreased risk of urinary tract infections
b) A progressive decline in renal function, a decrease in urine output, and recurrent UTIs
c) A decrease in urine output and an increase in blood pressure
d) A significant decrease in pain tolerance and an increase in overall health status
b) A progressive decline in renal function, a decrease in urine output, and recurrent UTIs. A transplant recipient with an encrusted stent usually presents with a progressive decline in renal function, a decrease in urine output, and recurrent UTIs.
What is the treatment for a retained stent caused by suture entrapment?
a) Endoscopic stitch transection
b) Antibiotic therapy
c) Immunosuppressive therapy
d) Conservative management
a) Endoscopic stitch transection. If the suture holds the stent, leaving the stent until the suture dissolves is an option versus endoscopic stitch transection.
What is the first step of management for stent encrustation?
a) Percutaneous nephrolithotomy
b) Retrograde intrarenal renal surgery
c) Extracorporeal wave shock lithotripsy
d) Urinary diversion by a nephrostomy tube
d) Urinary diversion by a nephrostomy tube. The first step of management for stent encrustation is typically a urinary diversion by a nephrostomy tube, which will allow for decompression of the renal collecting system, improvement in renal function, as well as antegrade access.
Why is a CT scan important in patients with stent encrustation?
a) To assess for ureteral obstruction
b) To assess for bacterial colonization
c) To assess encrustation burden and distribution
d) To assess for kidney denervation
c) To assess encrustation burden and distribution. A CT scan should be obtained in all patients with stent encrustation to assess encrustation burden and distribution, which will help guide the surgical approach.
What is the purpose of a nephrostomy tube in the management of stent encrustation?
a) To remove the encrusted stent
b) To allow for antegrade access
c) To reduce the risk of urinary tract infections
d) To document the encrustation burden and distribution
b) To allow for antegrade access. A nephrostomy tube is used in the management of stent encrustation to allow for decompression of the renal collecting system, improvement in renal function, as well as antegrade access.
What are some of the treatments for encrusted transplant stent?
a) Antibiotic therapy
b) Nephrostomy tube placement
c) Percutaneous nephrolithotomy, retrograde intrarenal renal surgery, and extracorporeal wave shock lithotripsy
d) Ureteral stent insertion
c) Percutaneous nephrolithotomy, retrograde intrarenal renal surgery, and extracorporeal wave shock lithotripsy. Different combinations of percutaneous nephrolithotomy, retrograde intrarenal renal surgery, and extracorporeal wave shock lithotripsy have been described to treat the encrusted transplant stent.
What is the goal of treating encrusted transplant stent?
a) To remove the stent
b) To improve renal function
c) To prevent stent encrustation
d) To reduce the risk of ureteral obstruction
b) To improve renal function. The goal of treating encrusted transplant stent is to improve renal function by removing the encrusted stent and treating the underlying cause of stent encrustation.
What is the purpose of a ureteral stent in renal transplantation?
a) To decrease the risk of bacterial colonization
b) To decrease ureteral stricture and urinary leak
c) To reduce the risk of stent encrustation
d) To improve team communication
b) To decrease ureteral stricture and urinary leak. The purpose of a ureteral stent in renal transplantation is to decrease ureteral stricture and urinary leak.