Peri Transplant Issues
Crossmatch
At the time of transplant donor cells and recipient plasma are sent to the HLA laboratory for compatibility testing using the CDC and Flow techniques. An excellent review on this subject has been published by Mulley and Kanellis in Nephrology 2011;16:125-133.
Graft Dysfunction
Graft Dysfunction may be a consequence of prolonged ischemic time due either to long distances or a result of explant issues resulting in prolonged "bucket" (i.e. waiting in OR for implant) or prolonged warm ischemic time if technical implant issues occur. Cardiac function may co-exist and compound the issue due to pulmonary edema. Graft dysfunction may also be caused by immunological incompatibility due to pre-existing donor specific HLA antibodies. Early utilization of ECMO support, if severe, is important.
Infections
Infections are a major threat after transplant - bacterial, viral and fungal all occur
Bacterial
Many patients with cystic fibrosis are colonised prior to transplant thus pseudomonas and enterobacter infections occur and are compounded by immunosuppression, poor mucociliary and lymphatic clearance and a poor cough. Most resolve with appropriate antibiotics.
Viral
CMV is a major threat to both short and long term graft function - hence the need for prophylaxis for up to 6 months with ganciclovir. HSV is also frequently a dormant virus that can cause pneumonia with immunosuppression - ganciclovir effectively suppresses it but acyclovir may also be required. EBV remains a threat but the spectrum of disease is wide - from asymptomatic replication to organ involvement through to malignancy and the treatment regimens are equally diverse with variable efficacy.
Fungal
Aspergillus colonisation pre transplant may also occur and voriconazole should be used as prophylaxis in these patients. Pneumocystis jirovecii now falls withing the fungal classification and trimethoprim-sulfamethoxazole prophylaxis is required for life.
Fluid and Inotropes Management
The CVP should be maintained within normal limits. Colloid replacement is generally preferred in the first 24 hours after HT, but blood, if indicated, is the first choice. Fluid restriction and loop diuretics are used to decrease volume overload. Early recourse should be made to hemofiltration or dialysis if medical measures are ineffective or renal function compromised.
Renal Failure
Renal function is often compromised post transplant and renal impairment or renal failure is common. As highlighted above, fluid management in the immediate period after transplant is very important and so if conservative measures are ineffective, early recourse to renal support with continuous veno-venous hemofiltration (CVVH) is appropriate.
Pleural Effusion
Pleural effusions are relatively frequent as a consequence of pleural inflammation and disruption of the lymphatics. They usually resolves with time but may require prolonged surgical drainage.
Airway Complications
Bronchial dehiscence
Bronchial dehiscence is relatively common after transplant due to ischemia. Bronchoscopy or CT scan can demonstrate the issue. Conservative management is often all that is required.
Anastomotic Strictures
Anastomotic strictures usually occur a little later and may be proximal at the anastomotic sites or more distal. Bronchoscopy to either balloon or stent the narrowing may be indicated.se usually occur a little later and may be proximal at the anastomotic sites or more distal. Bronhoscopy to either balloon or stent the narrowing may be indicated.
Posterior Reversible Encephalopathy Syndrome (PRES)
PRES typically presents with visual disturbance, headache, seizures, and impaired consciousness one to two weeks post transplant. Precipitating factors include electrolyte disturbance (especially low magnesium) and hypertension. Cystic fibrosis is a risk factor. Calcineurin inhibitors have also been implicated but given their universal use and that PRES occurs irrespective of levels their role in PRES is unclear. The mechanism underlying PRES is uncertain, but it is presumed that endothelial dysfunction is important. Magnetic resonance imaging typically demonstrates vasogenic oedema in subcortical white matter of the occipital and parietal regions, but other areas can be involved. Management includes addressing the electrolytes imbalance and especially hypertension while managing the neurological symptoms. The effectiveness of reducing calcineurin levels or switching to an alternative calcineurin remains unclear.
Further Reading
- Lung Transplantation. Author: Bryan A Whitson. Medscape.com. Updated: Apr 08, 2022
Last Updated: September 2022