Nonimmunologic Complications After Kidney Transplantation



Nonimmunologic Complications After Kidney Transplantation


Sagar Gupta

Tarek Alhamad



General Principles



  • Differential diagnosis for post-transplant allograft dysfunction depends on many factors; importantly, the timing after transplantation (please see Table 30-1).


  • For allograft dysfunction in the early perioperative period, urologic and vascular surgical complications should be investigated and the possibility of rejection considered; other common etiologies include hypovolemia, hyperglycemia, drug toxicity (commonly calcineurin inhibitor [CNI] toxicity), and infection.


  • Acute rejection, recurrent disease, chronic allograft nephropathy, CNI toxicity, BK virus nephropathy (BKVN), and transplant renal artery stenosis are transplant-specific causes of renal dysfunction. However, it is important to recognize that renal failure can also ensue from all causes affecting nontransplant patients.








TABLE 30-1 DIFFERENTIAL DIAGNOSIS OF RENAL ALLOGRAFT DYSFUNCTION
















































First Week Post-Transplant <3 Months Post-Transplant >3 Months Post-Transplant
Acute tubular necrosis Acute rejection Acute rejection
Accelerated rejection Calcineurin inhibitor toxicity Chronic rejection
Hypovolemia Hypovolemia Calcineurin inhibitor toxicity
Obstruction Hyperglycemia, hypercalcemia Hypovolemia
  Obstruction Obstruction
Urinary leak Infection Recurrent or de novo renal disease
Vascular thrombosis Infectious (e.g., BKVN) or drug-induced interstitial nephritis Infection
Atheroemboli Recurrent renal disease Transplant renal artery or iliac stenosis
Infections Malignancy (allograft PTLD) Malignancy
Thrombotic microangiopathy Thrombotic microangiopathy Thrombotic microangiopathy
BKVN, BK virus nephropathy; PTLD, post-transplant lymphoproliferative disorder.



Surgical Complications



  • Postoperative complications range between 5% and 10% (please see Table 30-2)


  • Arterial surgical complications include bleeding, renal artery thrombosis, and renal artery stenosis


  • Venous surgical complications include bleeding and renal vein thrombosis


  • Ureteral surgical complications include urinary leak and ureteral obstruction


  • Other complications are lymphocele, seromas, and infections


Infections



General Principles



  • A wide spectrum of potential pathogens infects immunocompromised hosts; many are infrequent pathogens in normal individuals.


  • Fever and physical signs of infection (e.g., erythema) are often diminished.


  • Risk factors for infections include:



    • Prior therapies (chemotherapy or antimicrobials)


    • Immunosuppressive therapy: type, temporal sequence, and intensity


    • Mucocutaneous barrier integrity (catheters, lines, drains)


    • Neutropenia, lymphopenia, hypogammaglobulinemia (often drug induced)


    • Technical complications (graft injury, fluid collections, wounds)


    • Underlying immune defects (e.g., genetic polymorphisms, autoimmune disease)


    • Metabolic conditions: uremia, malnutrition, diabetes, alcoholism, cirrhosis, advanced age


    • Viral infection (e.g., herpesviruses, hepatitides B and C, HIV, respiratory syncytial virus [RSV], influenza)


Cytomegalovirus (CMV)



General Principles



  • It is the human herpesvirus 5 (HHV-5).


  • Seroprevalence of CMV is around 60% in the general population and it varies according to the age and race.1


  • Transmission is through blood, sexual intercourse, and transplanted organs.


  • Active infection in kidney transplant recipients is 30% to 70% without prophylaxis at 1 month from transplant with the highest rate in patients with donor CMV IgG positive into recipient CMV IgG negative.2


  • CMV infection leads to increased morbidity, mortality, and allograft failure.


  • Risk factors for CMV infection:



    • Highest risk: CMV donor positive into recipient-negative serostatus


    • Comorbid illnesses


    • Neutropenia


    • Lack of CMV prophylaxis


  • CMV infection is uncommon in CMV negative into recipient-negative serostatus.


  • Often considered as a disease of overimmunosuppression.










TABLE 30-2 SURGICAL COMPLICATIONS AFTER TRANSPLANTATION: CAUSES, SYMPTOMS, AND MANAGEMENT

















































Surgical Complication Causes/Risk factors Signs and Symptoms Evaluation and Treatment
Arterial bleeding Anastomotic leak
Systemic anticoagulation
Bleeding diathesis
Hypotension
Tachycardia
Drop in hematocrit
Allograft dysfunction from compression
Blood transfusion
Imaging (US/CT)
Conservative management
Surgical exploration and evacuation (if not a brisk or significant bleed and/or allograft dysfunction)
Venous bleeding Anastomotic leak
Systemic anticoagulation
Bleeding diathesis
Hypotension
Tachycardia
Drop in hematocrit
Allograft dysfunction from compression
Blood transfusion
Imaging (US/CT)
May need surgical exploration and evacuation
Renal artery thrombosis Hypotension
Hyperacute or unresponsive acute rejection
Hypercoagulable state
Multiple renal arteries
Unidentified intimal flaps
Occurs early after transplant
Sudden-onset oliguria/anuria (often complete)
AKI
Hyperkalemia
US Doppler shows no flow
Radionuclide renal scan shows no uptake
Immediate return to operation room for thrombectomy, but may need allograft nephrectomy
Renal vein thrombosis Hypercoagulable state
Hematomas or lymphoceles causing compression
Anastomotic stenosis
Extension of a DVT
Occurs early after transplant
Tender swollen allograft
Hematuria
US Doppler shows decreased flow in vein
Attempt at thrombectomy, but may need allograft nephrectomy if unsuccessful
Urinary leak Ureteral necrosis
Disrupted anastomosis
Decreased urine output
Pain due to urine irritation
AKI
US, nuclear scan or CT shows fluid collection
If Jackson–Pratt (JP) drain is present, JP fluid Cr will be elevated (equals urine creatinine)
Treat with Foley catheter, nephrostomy, or surgical revision of anastomosis
Ureteral obstruction Extrinsic: fluid collection or mass compressing the ureter
Intrinsic: ureteral stenosis, structure, renal calculi
Late stricturing can be seen in BK nephropathy
Decreased urine output
AKI
US dilation of ureter
Nuclear scan shows poor flow/retained tracer
Treat with percutaneous nephrostomy with stenting and dilation, surgical revision of anastomosis
Lymphocele   Decreased urine output
AKI (if compresses allograft)
Suprapubic pressure
Scrotal edema
Unilateral leg edema
Possible DVT
US or CT will show fluid collection, compression of allograft, or hydronephrosis.
Drain lymphocele (percutaneous in VIR or laparoscopic)
Peritoneal window to prevent recurrence
Renal artery stenosis Difficulties in harvesting and operative techniques
Atherosclerotic disease
CMV infection
Delayed graft function
Most commonly between 3 months and 2 years
Difficult to control or acute increase in BP
Fluid retention
Flash pulmonary edema
Allograft dysfunction which worsens with ACEi/ARB
Screening with US Doppler: shows increased velocity at stenosis site
Confirmatory tests: MR/CT angiography
Arteriography is ideal but invasive—diagnose and treat at same time
Treat with endovascular stenting
Rarely surgical redo of anastomosis may be needed
ACEi, angiotensin-converting enzyme inhibitor; AKI, acute kidney injury; ARB, angiotensin receptor blocker; BP, blood pressure; CMV, cytomegalovirus; CT, computed tomography; DVT, deep venous thrombosis; US, ultrasound; VIR, vascular interventional radiology.

Only gold members can continue reading. Log In or Register to continue

Apr 17, 2020 | Posted by in NEPHROLOGY | Comments Off on Nonimmunologic Complications After Kidney Transplantation
Premium Wordpress Themes by UFO Themes