Introduction: Ex vivo normothermic perfusion (EVNP) is increasingly recognised as a viability tool to increase organ utilisation. We report use of EVNP to assess graft perfusion of potential domino transplants following therapeutic nephrectomy and backbench arterial reconstruction in four cases of refractory hypertension secondary to renal artery stenosis (RAS) unsuitable for endovascular treatment.

Case Detail: Patient A and Patient B had isolated unilateral RAS presumed secondary to fibromuscular dysplasia. Pre-operative imaging and functional assessment revealed a split function of the affected kidneys to be 38% and 43%, for Patient A and  Patient B, respectively. Patient C and Patient D had a wider distribution of vascular occlusive disease. Patient C had an occluded left renal artery with an atrophic left kidney and no evidence of function on isotope imaging. Following unsuccessful angioplasty and stenting, Patient D had developed in stent occlusion; subsequent imaging demonstrated hypo-perfused right kidney with 6% estimated split function.

Outcome: Following nephrectomy, all kidneys were prepared on the backbench for EVNP. For Patient A and Patient B, a common stem was created using spatulation of the renal artery and reconstruction with collateral vessels (plus saphenous vein patch in Patient B). Both grafts perfused well with excellent global perfusion and urine output (EVNP assessment score=1). Beyond the stent stenosis, the renal artery from Patient C was short but allowed cannulation following dilatation. Patient D required separate cannulation (to renal artery and main collateral) with 14G cannula. Patient C and Patient D demonstrated high resistance and poorer perfusion (EVNP assessment score=4). The kidneys from Patient A and Patient B were successfully transplanted into two dialysis-dependent patients who achieved primary function and eGFR of 58 and 62ml/min/1.73m2, respectively.

Discussion: The demonstration of adequate arterial reconstruction plus excellent graft perfusion whilst on EVNP, alongside favourable pre-operative functional imaging, provided confidence to transplant two marginal domino grafts.