Simultaneous transplantation of the pancreas and kidney still represents the gold standard surgical treatment for patients with insulin dependent diabetes mellitus type-1 and end stage renal disease. In this context, it has been reported that long-term normoglycemia following successful SPKT sustains significant improvement of diabetic retinopathy and glomerulosclerosis, and that the human kidney even has the potential to substantially restore glomerular and tubular structures that have been previously injured by long term diabetes.
In contrast, data on the potential reversal or progression of macroangiopathic lesions by SPKT are far from clear. On one hand several studies report a significant higher incidence of PVD and worse vascular outcomes in patients with a SPKT when compared to those receiving a kidney transplant alone. A recent long-term study on incidence and risk factors in SPKT patients also reported a higher incidence of amputation after SPKT when compared to KTA.
Medical data from patients with IDDM who underwent SPKT or KTA at the University Hospital of Leipzig between 2000 and 2013 were retrospectively analysed. Special emphasis was placed on patient and graft characteristics, cardiovascular risk factors, metabolic outcomes and status of PVD. Progression of PVD was determined by evaluating the number of patients with PVCs, defined as any midfoot and limb amputation, ischemic ulceration, lower extremity bypass surgery or angioplasty. Organ procurement and transplantation - n short, the pancreas was explanted in a no-touch technique en-bloc with the spleen and duodenum. Back table preparation included removal of the spleen and peripancreatic fat. Reconstruction of the superior mesenteric and the lineal artery was performed using the donor iliac Y-graft. The immunosuppressive protocol consisted of an induction therapy followed by triple maintenance therapy.
Overall study population included 127 patients receiving a Simultaneous Pancreas Kidney transplantation (SPKT, n = 101) or Kidney Transplantation Alone (KTA, n = 26). Mean follow-up period was 101 ± 34.4 months. Donor, recipient, and pre-transplant baseline characteristics according to transplant types are summarized in Table 1. In the KTA group, 9 (34%) patients had type 1 and 17 (66%) patients had type 2 insulin dependent diabetes mellitus.
Peripheral vascular diseases and complications before transplantation
In addition to physical examination, vascular status was evaluated in all patients by imaging. Vascular imaging included 115 duplex sonography examinations, 114 Magnetic Resonance Angiographies (MRA) or Computed Tomography Angiographies (CTA) and 28 conventional contrast angiograms.
Side of peripheral vascular disease and transplant location
There were 21 ischemic events of the lower extremity in the SPKT group. Four of these were on the right side, distal to where the pancreas graft was implanted and 17 on the left side where the kidney was implanted. Using logistic regression analysis, clinical symptoms of ischemia were more likely attributed to the left lower extremity.
Peripheral vascular disease is a serious affection in patients qualifying for kidney and/or combined pancreas kidney transplantation. From a demographic perspective, patients evaluated for KTA were significantly older and had a higher number of cardiovascular risk factors including higher BMI, high blood pressure and presence of cardiovascular disease making a direct comparison with younger and leaner IDDM1 patients not feasible. Risk factor adjusted multivariate subgroup analysis, however, revealed that patients undergoing KTA are more likely to have progression of PVD leading to increased rates of PVC.
In subgroup analysis, we could demonstrate that at 8.4 years of functioning pancreas graft the progression of macrovascular diseases is significantly reduced in diabetic patients with SPKT when compared to recipients of KTA. This vascular protective effect after SPKT could be explained by a better vascular risk profile of SPKT recipients compared to KTA recipients. Furthermore, our study demonstrates that SPKT and KTA can be performed safely in diabetic patients with ERSD even in (a) symptomatic patients with PAD, without deterioration of lower extremity ischemia. Further studies are surely required, in lager series, to investigate the natural history and course of PVD before and after SPKT compared to KTA in diabetic patients.