Lower Extremity Peripheral Arterial Disease and Its Relationship with Adverse Outcomes in Kidney Transplant Recipients: A Retrospective Cohort Study

The purpose of the study was to characterize lower extremity peripheral arterial disease (LEPAD) in a series of kidney transplant patients and to assess the impact on adverse outcomes. A retrospective cohort study was conducted including kidney transplant recipient patients who underwent screening for LEPAD. The outcomes evaluated were classified as perioperative and post-transplant, including cardiovascular events, amputation, mortality, and loss of the graft. A total of 141 renal transplant patients screened for LEPAD were identified, with an average follow-up of 3 years. LEPAD occurred in 14.2% (20/141). No differences in cardiovascular risk factors were found between the groups, except for smoking (45% vs. 24%, p < 0.05). In the group with LEPAD, the most compromised anatomical segment was the infrapopliteus, with no iliac involvement found. The Cox proportional hazards model indicated that the variables age, gender, and weight were significant in patients with LEPAD. There were no differences between the groups in terms of graft loss and death. The infrapopliteal segment is the area of greatest stenosis in kidney transplant patients with LEPAD. Together with smoking, they can explain the presence of major amputations in kidney transplant patients; however, they had no impact on graft functionality or death.

The influence of simultaneous pancreas-kidney transplantation on the evolution of diabetic foot lesions and peripheral arterial disease

PURPOSE

Simultaneous pancreas-kidney transplantation (SPKT) remains the best treatment option in patients with type 1 diabetes and chronic kidney failure. There are only a few studies addressing the potential ischemic deterioration of peripheral arterial disease (PAD) due to blood diverting from the iliac artery to the kidney graft. We aimed to evaluate diabetic foot lesions and PAD evolution in SPKT recipients and investigate if they are more frequent in ipsilateral lower limb of kidney graft.

METHODS

We developed a retrospective cohort, including patients submitted to SPKT in our tertiary center, between 2000 and 2017. Diabetic foot lesions and PAD frequencies were compared in the period before and after transplantation.

RESULTS

Two hundred and eleven patients were included, 50.2% (n = 106) female, with a median age at transplantation of 35 years (IQR 9). After a median follow-up period of 10 years (IQR 7), patient, kidney, and pancreatic graft survival were 90.5% (n = 191), 83.4% (n = 176), and 74.9% (n = 158), respectively. Before transplant, 2.8% (n = 6) had PAD and 5.3% (n = 11) had history of foot lesions. In post-transplant period, 17.1% (n = 36) patients presented PAD and 25.6% (n = 54) developed diabetic foot ulcers, 47.6% (n = 35) of which in the ipsilateral and 53.3% (n = 40) in the contralateral lower limb of the kidney graft (p = 0.48). Nine patients (4.3%) underwent major lower limb amputation, 3 (30%) ipsilateral and 7 (70%) contralateral to the kidney graft (p = 0.29).

CONCLUSIONS

Diabetic foot lesions were not more frequent in the ipsilateral lower limb of the kidney graft, therefore downgrading the 'steal syndrome' role in these patients.

Rate of Ipsilateral Chronic Limb-Threatening Ischemia (CLTI) After Kidney Transplantation: A Retrospective Single-Center Study

Objective: To analyze whether the rate of lower extremity (LE) ischemia is higher on the ipsilateral side after kidney transplantation.

Methods: Our institutional transplant database was retrospectively queried for all patients who received a kidney transplant and underwent subsequent LE revascularization or major limb amputations between January 2004 and July 2020. The one-sample binomial test was used to test whether the LE ipsilateral to the transplanted kidney was at higher risk of peripheral arterial disease (PAD) complications necessitating intervention (major amputation or revascularization).

Results: There were 1,964 patients who received a kidney transplant during the study period. Of these, 51 patients (3%) had subsequent LE arterial revascularizations or major amputations. The mean age was 58 ± 10 years, and 37 patients (73%) were male. A total of 33 patients had ipsilateral LE vascular interventions (26 major amputations and seven revascularizations) while 18 patients had contralateral vascular interventions (14 major amputations and four revascularizations) (P = 0.049). The average interval between transplantation and subsequent vascular intervention was 52 months for the ipsilateral intervention group and 41 months for the contralateral intervention group (P = 0.33).

Conclusions: In patients who received kidney transplantation and required subsequent LE surgical intervention, we observed an association between the side of transplantation and the risk of future ipsilateral LE arterial insufficiency. Further studies are needed to determine the etiology of this association.

Peripheral Vascular Disease and Kidney Transplant Outcomes: Rethinking an Important Ongoing Complication

Peripheral vascular disease (PVD) is highly prevalent in patients on the waiting list for kidney transplantation (KT) and after transplantation and is associated with impaired transplant outcomes. Multiple traditional and nontraditional risk factors, as well as uremia- and transplant-related factors, affect 2 processes that can coexist, atherosclerosis and arteriosclerosis, leading to PVD. Some pathogenic mechanisms, such as inflammation-related endothelial dysfunction, mineral metabolism disorders, lipid alterations, or diabetic status, may contribute to the development and progression of PVD. Early detection of PVD before and after KT, better understanding of the mechanisms of vascular damage, and application of suitable therapeutic approaches could all minimize the impact of PVD on transplant outcomes. This review focuses on the following issues: (1) definition, epidemiological data, diagnosis, risk factors, and pathogenic mechanisms in KT candidates and recipients; (2) adverse clinical consequences and outcomes; and (3) classical and new therapeutic approaches.

KDIGO Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation

The 2020 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation is intended to assist health care professionals worldwide who evaluate and manage potential candidates for deceased or living donor kidney transplantation. This guideline addresses general candidacy issues such as access to transplantation, patient demographic and health status factors, and immunological and psychosocial assessment. The roles of various risk factors and comorbid conditions governing an individual's suitability for transplantation such as adherence, tobacco use, diabetes, obesity, perioperative issues, causes of kidney failure, infections, malignancy, pulmonary disease, cardiac and peripheral arterial disease, neurologic disease, gastrointestinal and liver disease, hematologic disease, and bone and mineral disorder are also addressed. This guideline provides recommendations for evaluation of individual aspects of a candidate's profile such that each risk factor and comorbidity are considered separately. The goal is to assist the clinical team to assimilate all data relevant to an individual, consider this within their local health context, and make an overall judgment on candidacy for transplantation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Guideline recommendations are primarily based on systematic reviews of relevant studies and our assessment of the quality of that evidence, and the strengths of recommendations are provided. Limitations of the evidence are discussed with differences from previous guidelines noted and suggestions for future research are also provided.

Impact of Aortoiliac Stenosis on Graft and Patient Survival in Kidney Transplant Recipients Using the TASC II Classification

BACKGROUND

Patients with end-stage renal disease and aortoiliac stenosis are often considered ineligible for kidney transplantation, although kidney transplantation has been acknowledged as the best therapy for end-stage renal disease. The clinical outcomes of kidney transplantation in patients with aortoiliac stenosis are not well-studied. This study aimed to assess the impact of aortoiliac stenosis on graft and patient survival.

METHODS

This retrospective, single-center study included kidney transplant recipients transplanted between January 1, 2000, and December 31, 2016, who received contrast-enhanced imaging. Patients with aortoiliac stenosis were classified using the Trans-Atlantic Inter-Society Consensus (TASC) II classification and categorized as having TASC II A/B lesions or having TASC II C/D lesions. Patients without aortoiliac stenosis were functioning as controls.

RESULTS

A total number of 374 patients was included in this study (n = 88 with TASC II lesions, n = 286 as controls). Death-censored graft survival was similar to the controls. Patient and uncensored graft survival was decreased in patients with TASC II C/D lesions (log-rank test P < 0.001). Patients with TASC II C/D lesions had a higher risk of 90-day mortality (hazard ratio, 3.96; 95% confidence interval, 1.12-14.04). In multivariable analysis, having a TASC II C/D lesion was an independent risk factor for mortality (hazard ratio, 3.25; 95% confidence interval, 1.87-5.67; P < 0.001). Having any TASC II lesion was not a risk factor for graft loss (overall P = 0.282).

CONCLUSIONS

Kidney transplantation in patients with TASC II A/B is feasible and safe without increased risk of perioperative mortality. TASC II C/D decreases patient survival. Death-censored graft survival is unaffected.

The prognosis of kidney transplant recipients with aorto-iliac calcification: a systematic review and meta-analysis

The prognosis of kidney transplant recipients (KTR) with vascular calcification (VC) in the aorto-iliac arteries is unclear. We performed a systematic review and meta-analysis to investigate their survival outcomes. Studies from January 1st, 2000 until March 5th, 2019 were included. Outcomes for meta-analysis were patient survival, (death-censored) graft survival and delayed graft function (DGF). Twenty-one studies were identified, eight provided data for meta-analysis. KTR with VC had a significantly increased mortality risk [1-year: risk ratio (RR) 2.19 (1.39-3.44), 5-year: RR 2.28 (1.86-2.79)]. The risk of 1-year graft loss was three times higher in recipients with VC [RR 3.15 (1.30-7.64)]. The risk of graft loss censored for death [1-year: RR 2.26 (0.58-2.73), 3-year: RR 2.19 (0.49-9.82)] and the risk of DGF (RR 1.24, 95% CI 0.98-1.58) were not statistically different. The quality of the evidence was rated as very low. To conclude, the presence of VC was associated with an increased mortality risk and risk of graft loss. In this small sample size, no statistical significant association between VC and DGF or risk of death-censored graft loss could be demonstrated. For interpretation of the outcomes, the quality and sample size of the evidence should be taken into consideration.

Simultaneous recipient external iliac endarterectomy and renal transplant - a propensity score matched analysis

Patients with end-stage renal disease and severe iliac atherosclerosis are frequently denied renal transplant due to technical challenges, and risk of potential steal syndrome in the allograft, or ipsilateral limb. Few studies have evaluated the safety and efficacy of performing an endarterectomy in this setting. A single-center retrospective review of renal transplant patients from 1/2013 to 12/2017 was performed. Patients requiring endarterectomy at the time of transplant were matched to a nonendarterectomized cohort in a 1:2 fashion using propensity score matching. Patients were followed for a minimum of 12 months. Simultaneous endarterectomy and renal transplant were performed in 23 patients and subsequently matched to 42 controls. Ankle-brachial index was lower in the endarterectomized group (P = 0.04). Delayed graft function (26.1% vs. 19%, P = 0.54), graft loss (8.7% vs. 7.1%, P = 0.53), 1-year mortality (8.7% vs. 4.8%, P = 0.53), and renal function at 12 months were comparable in both groups. There were no incidents of ipsilateral limb loss in the endarterectomized population. This is the first matched study investigating endarterectomy and renal transplant. Long-term follow-up of limb and graft function is indicated. Despite the small sample size, our findings suggest that a combined procedure can safely provide renal transplantation access to a previously underserved population.

Orthotopic Kidney Transplantation in an Elderly Patient With Various Severe Comorbid Conditions: A Case Report

In recent years, the frequency of high-risk kidney transplantations has increased. We report a case in which a 72-year-old man with various severe comorbidities (prostate cancer, diabetes mellitus, complete atrioventricular block, coronary artery stenosis, severe stenosis of the popliteal arteries, and severe calcification of the iliac arteries) who received an orthotopic kidney transplantation. To prevent the occurrence of acute limb ischemia due to the steal phenomenon (caused by the kidney graft), we decided that a heterotopic kidney transplantation involving the iliac arteries was not an appropriate option. Therefore, as an alternative, left native nephrectomy was performed followed by an orthotopic kidney transplantation to the native renal artery and renal vein through a left subcostal incision. Postoperative ureteral stenosis occurred, and so stent exchange was required every 6 months. Despite the ureteral complication, the patient's serum creatinine level was 1.5 mg/dL at 2 years after the procedure.