Peripheral vascular occlusive disease in renal transplant recipients: risk factors and impact on kidney allograft survival

Recipient Comorbidities for Prediction of Primary Graft Dysfunction, Chronic Allograft Dysfunction and Survival After Lung Transplantation

Since candidates with comorbidities are increasingly referred for lung transplantation, knowledge about comorbidities and their cumulative effect on outcomes is scarce. We retrospectively collected pretransplant comorbidities of all 513 adult recipients transplanted at our center between 1992–2019. Multiple logistic- and Cox regression models, adjusted for donor-, pre- and peri-operative variables, were used to detect independent risk factors for primary graft dysfunction grade-3 at 72 h (PGD3-T72), onset of chronic allograft dysfunction grade-3 (CLAD-3) and survival. An increasing comorbidity burden measured by Charleston-Deyo-Index was a multivariable risk for survival and PGD3-T72, but not for CLAD-3. Among comorbidities, congestive right heart failure or a mean pulmonary artery pressure >25 mmHg were independent risk factors for PGD3-T72 and survival, and a borderline risk for CLAD-3. Left heart failure, chronic atrial fibrillation, arterial hypertension, moderate liver disease, peptic ulcer disease, gastroesophageal reflux, diabetes with end organ damage, moderate to severe renal disease, osteoporosis, and diverticulosis were also independent risk factors for survival. For PGD3-T72, a BMI>30 kg/m2 was an additional independent risk. Epilepsy and a smoking history of the recipient of >20packyears are additional independent risk factors for CLAD-3. The comorbidity profile should therefore be closely considered for further clinical decision making in candidate selection.

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.

Evaluation of the Effectiveness of Screening for Iliac Arterial Calcification in Kidney Transplant Candidates

Background

Peripheral vascular disease and iliac arterial calcification are prevalent in kidney transplant candidates and jeopardize graft outcomes. We report our experience with computed tomography (CT) screening for iliac arterial calcification.

Material/Methods

We retrospectively reviewed electronic medical records of 493 renal transplant candidates from protocol initiation in 2014. Non-contrast CT was performed or retrospectively reviewed if any of the following criteria were present: diabetes, ESRD >6 years, 25 pack-years of smoking or current smoker, diagnosis of peripheral vascular disease, parathyroidectomy, and coronary artery disease intervention. Differences in evaluation and transplant outcomes between groups were compared with chi-squared analysis. Multivariate logistic regression identified predictive criteria for presence of iliac arterial calcification.

Results

Of 493 candidates evaluated, CTs were reviewed in 346 (70.2%). Iliac arterial calcification was identified in 119 screened candidates (34.4%). Of candidates with iliac arterial calcification identified on CT, 16 (13.4%) were excluded for CT findings, and 9 (7.6%) had their surgical management plan changed. Overall, 91 (76.5%) candidates with iliac arterial calcification on CT were approved, compared to 203 (89.4%) without calcification (P<0.001). The percentage of screened patients with iliac arterial calcification on CT increased with increasing age (P<0.0005). Age and diabetes mellitus were predictive of calcification.

Conclusions

Many kidney transplant candidates are at risk for iliac arterial calcification, although such calcification does not prevent transplantation for most candidates who have it. Algorithmic pre-operative screening has clinical value in determining transplant candidacy and potentially improving postoperative outcomes in patients requiring kidney transplantation.

Skin disorders indicating peripheral arterial occlusive disease and chronic venous insufficiency in organ transplant recipients

BACKGROUND

Peripheral arterial occlusive disease (PAOD) and chronic venous insufficiency (CVI) in organ transplant recipients (OTR) can lead to harmful outcomes. We made an inventory of cutaneous manifestations of PAOD and CVI in OTR in relation with diabetes and other potential risk factors.

METHODS

A prospective study in a single center was performed. OTR (n = 112) were included at the outpatient clinic to investigate clinical signs of PAOD and CVI. The most commonly associated risk factors were determined.

RESULTS

PAOD had been diagnosed in 15.6% and CVI in 30.0% of the patients. Diabetes was the cause of organ failure in 9.8% of the patients. Type 1 diabetes had been diagnosed in 8.9% and type 2 diabetes in 21.4% (59.1% new-onset diabetes after transplantation). Type 1 diabetes showed an increased risk for PAOD and limb amputation with hazard ratios of 11.0 (95%CI 3.0-40.2) and 9.1 (95%CI 1.4-58.6). Type 2 diabetes showed no increased risk.

CONCLUSIONS

Patients with a history of type 1 diabetes were at high risk for PAOD even years after a simultaneous pancreas kidney transplantation and they should remain under close observation for PAOD even though they are supposedly "cured" from their diabetes to prevent a harmful outcome.

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.

Recent History of Serious Fall Injuries and Posttransplant Outcomes Among US Kidney Transplant Recipients

BACKGROUND

Serious fall injuries are associated with poor outcomes among dialysis patients, but whether these associations hold in patients with a history of serious fall injury before kidney transplantation is unknown.

METHODS

In national administrative data, 22 474 US adults receiving a first kidney transplant in 2011-2014 with at least 1 year of follow-up before transplant were identified. Serious fall injuries in the year before transplant were identified using diagnostic codes for falls and simultaneous fractures, dislocations, or head trauma in inpatient or outpatient claims. We used multivariable Cox proportional hazards models to estimate associations of incident posttransplant outcomes with serious fall injury in the year before transplant.

RESULTS

A total of 620 (2.8%) recipients had serious fall injuries before transplant and were more likely to be white, female, and have more comorbid conditions than those without a fall injury. Although posttransplant recipient survival did not differ by recent serious fall injuries (hazard ratio [HR], 1.03; 95% confidence interval [CI], 0.78-1.36), these injuries were associated with 33% higher rates of graft failure (HR, 1.33; 95% CI, 1.03-1.72). Patients with serious fall injuries spent 12.1% of posttransplant follow-up hospitalized, a 3.3-fold higher rate than those without a fall, and had nearly 2-fold higher rates of skilled nursing facility utilization (HR, 1.98; 95% CI, 1.52-2.57).

CONCLUSIONS

Serious fall injuries are independently associated with significantly greater resource requirements and lower graft survival. Further study is needed to delineate the relationship between falls and adverse outcomes in transplant and reduce the incidence and deleterious effects of these events.

Prognostic Value of Aortoiliac Calcification Score in Kidney Transplantation Recipients

BACKGROUND

Kidney recipients are increasingly older with arterial disease and extended arterial calcifications. In a kidney transplantation population, the prognosis value of aortic and iliac calcifications remains poorly explored. We aimed to assess the impact of pretransplantation aortoiliac vascular calcifications on patients, grafts survival, and cardiovascular events.

METHODS

This retrospective study included kidney transplantation patients from 2006 to 2012 for whom we had available presurgery abdominal computed tomography results (n = 100). We designed a score to quantify aortoiliac calcifications. Primary end points were patient and graft survival. Secondary end points were renal function and cardiovascular morbidity. Predictive performances of calcification score were assessed using area under receiver-operating characteristic curves. Patients were classified in quartiles depending on global calcium score value.

RESULTS

The cumulated rate of death and graft loss was 13% with no significant differences for survival between quartiles. No significant difference was observed in renal function (P = 0.4). Seventeen cardiovascular events were registered with a significant correlation between calcium score elevation and need of cardiovascular surgery during the follow-up (P = 0.01). Global calcium score had a predictive value of 74.5% (95% confidence interval 0.62-0.87) with 71% sensitivity and 73% specificity.

CONCLUSIONS

Aortoiliac calcifications do not decrease patient and graft survival. High calcium score predict cardiovascular events and procedures during the follow-up.

Cardiovascular risk factors following renal transplant

Kidney transplantation is the gold-standard treatment for many patients with end-stage renal disease. Renal transplant recipients (RTRs) remain at an increased risk of fatal and non-fatal cardiovascular (CV) events compared to the general population, although rates are lower than those patients on maintenance haemodialysis. Death with a functioning graft is most commonly due to cardiovascular disease (CVD) and therefore this remains an important therapeutic target to prevent graft failure. Conventional CV risk factors such as diabetes, hypertension and renal dysfunction remain a major influence on CVD in RTRs. However it is now recognised that the morbidity and mortality from CVD are not entirely accounted for by these traditional risk-factors. Immunosuppression medications exert a deleterious effect on many of these well-recognised contributors to CVD and are known to exacerbate the probability of developing diabetes, graft dysfunction and hypertension which can all lead on to CVD. Non-traditional CV risk factors such as inflammation and anaemia have been strongly linked to increased CV events in RTRs and should be considered alongside those which are classified as conventional. This review summarises what is known about risk-factors for CVD in RTRs and how, through identification of those which are modifiable, outcomes can be improved. The overall CV risk in RTRs is likely to be multifactorial and a complex interaction between the multiple traditional and non-traditional factors; further studies are required to determine how these may be modified to enhance survival and quality of life in this unique population.

Kidney transplantation outcomes from expanded criteria donors, standard criteria donors or living donors older than 60 years

OBJECTIVES

To evaluate outcomes in kidney allograft recipients from donors with expanded criteria (ECD) versus standard criteria (SCD) or living donors (LD) >60 years.

METHODS

We studied all patients who received a kidney between 2005 and 2011, focusing in recipients of kidneys from deceased ECD, SCD and LD >60 years. ECD was any deceased donor >60 years or >50 years with two of the following: hypertension (HTN), stroke as the cause of death, or serum creatinine >1.5 mg/dL. We recorded characteristics of the transplant procedure, patient, graft survival and renal function 1 year after transplantation and at the end of follow-up.

RESULTS

Six-hundred and five patients were transplanted between 2005 and 2011 in our department. There were 142 (25.1%) transplantations from ECD, 192 (33.98%) from SCD and 96 (16.99%) from LDs older than 60 years. In a mean follow-up time of 36.4 months, graft survival rates were similar for all groups. Calculated GFR was found statistically different between the ECD and SCD groups, but still satisfactory at first year, and at end of follow-up time. Comparison of the patients, who received transplants from ECD, even older than 70 years, and those from LD >60 years revealed equivalent renal function in short and long term.

CONCLUSIONS

Utilization of marginal kidneys effectively doubled our deceased transplant volume in the period 2005-2011. Patients' and graft survival were shown similar at the end of follow-up for all groups. Renal outcomes were shown equivalent between the ECD and LD >60 years groups, and although significantly lower between the ECD and the SCD group, were still very satisfactory.

Effect of peripheral vascular disease on kidney allograft outcomes: a study of U.S. Renal data system

BACKGROUND

The U.S. Renal Data System was used to analyze renal allograft outcomes in patients with peripheral vascular disease (PVD) at the time of transplant listing.

METHODS

We used an incident cohort of patients who underwent renal transplantation between June 2004 and September 2009. We defined PVD as symptomatic PVD at wait-listing. Comorbid conditions were diabetes mellitus, ischemic heart disease, cerebrovascular disease, hypertension, and smoking. Chi-square test, Student's t test, and Cox regression were used for statistical associations.

RESULTS

The mean graft survival was 55.3±0.40 months in patients with PVD versus 60.8±0.06 months in patients without PVD. There was an increased risk of graft failure with PVD (hazard ratio, 2.01; 95% confidence interval, 1.83-2.21; P=0.0001). After adjusting for other variables, PVD remained an independent risk factor for graft failure. Patients with PVD had lower death-censored graft survival versus patients without PVD at 1 year (93.3% vs. 96.6%), 2 years (89.7% vs. 95%), and 3 years (87.2% vs. 93.7%). All-cause mortality was higher in PVD versus without PVD (6.2% vs. 3.0%). In African Americans, the mean allograft survival was 54.8±0.98, months with PVD versus 59.7±0.135 months without PVD (P=0.0001). In non-African Americans, the mean allograft survival was 55.4±0.44 months with PVD versus 61.1±0.069 months without PVD (P=0.0001). There were no differences in survival between African Americans with PVD and non-African Americans with PVD.

CONCLUSIONS

Patients with PVD have inferior allograft and patient survival versus those without PVD. Caution should be exercised when placing patients with symptomatic PVD or amputation on the wait-list.

The prognostic significance of iliac vessel calcification in renal transplantation

BACKGROUND

Peripheral vascular disease and major extremity amputation are common in patients with established renal failure and are associated with considerable morbidity. Several studies have shown high rates of amputation following simultaneous pancreas-kidney transplantation, but there is minimal literature on the incidence of amputation following renal transplantation. Furthermore, there is little evidence regarding the best method of predicting which patients might be at risk of developing peripheral vascular complications after transplantation.

METHODS

We undertook a 5 year follow-up on the cohort of patients who were on our renal transplant waiting list 5 years ago (January 2007). At this time, it was standard practice within our unit for all patients to have routine pelvic x-rays to assess for vascular calcification of the iliac vessels at the time of activation onto the transplant waiting list. Any patients with moderate/severe calcification on x-ray, which may complicate transplantation, were referred for computed tomography angiogram (CTA) of their aorto-iliac vessels. Mortality, transplantation outcomes, and amputation rates at 5 years were correlated with the severity of calcification on preoperative imaging.

RESULTS

One hundred eighty-seven patients were on the waiting list for renal transplantation in January 2007 (92 men; mean age, 58.3 +/- 6.2 years). Ninety-three patients received a transplant during the subsequent 5 years. By January 2012, 82 patients had a functioning transplant, 45 remained on the waiting list (5 suspended), 40 patients had died, and 20 were alive but no longer on the waiting list. Seventy-three (39.5%) had moderate or severe calcification on plain x-ray and went on to have CTA. Of these patients, 16 (21.9%) had extensive calcification affecting all the iliac vessels and were removed from the waiting list as a result. Preoperative imaging was useful in determining the side for surgery in a further 18 patients (24.3%). Twenty-two patients developed vascular complications. Nineteen (86.4%) had moderate-severe vascular calcification on imaging. Four of the patients with vascular complications (18.2%) underwent transplantation (2 had below knee amputation (BKA) prior to transplantation; 1 developed distal ischemia on the same side as the transplantation 2 years postoperatively; 1 had bilateral above knee amputation (AKA) approximately 2 years after transplantation). Eleven (50%) of the patients with vascular complications were dead at 5 years of follow-up. Mortality and amputation rates were higher in patients with moderate-severe calcification than minimal calcification (30.1% vs 16.6%; P = .02 and 10.9% vs 1.8%; P = .003, respectively). There was no difference in rates of delayed graft function (DGF), biopsy-proven acute rejection (BPAR), or creatinine at 1 year between patients who underwent transplantation with moderate-severe calcification and those without, however, intraoperative vascular complications (26.7% vs 3%; P < .001), graft loss (28.1% vs 3.4%; P = .01), and death with a functioning transplant (9.7% vs 1.6%; P = .04) rates were higher in patients with extensive calcification compared with those without.

CONCLUSIONS

Plain x-ray of the pelvis is a useful screening tool to identify those patients who may require further detailed vascular imaging prior to transplantation. Amputation rates following renal transplantation are low and peripheral vascular disease (PVD) in isolation should not preclude transplantation. Nevertheless, significant vascular calcification is predictive of mortality both with and without transplantation and graft loss in patients with a renal transplant.

KDIGO clinical practice guideline for the care of kidney transplant recipients

The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the monitoring, management, and treatment of kidney transplant recipients is intended to assist the practitioner caring for adults and children after kidney transplantation. The guideline development process followed an evidence-based approach, and management recommendations are based on systematic reviews of relevant treatment trials. Critical appraisal of the quality of the evidence and the strength of recommendations followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. The guideline makes recommendations for immunosuppression, graft monitoring, as well as prevention and treatment of infection, cardiovascular disease, malignancy, and other complications that are common in kidney transplant recipients, including hematological and bone disorders. Limitations of the evidence, especially on the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.

The Impact of Recipient History of Cardiovascular Disease on Kidney Transplant Outcome

Cardiovascular disease (CVD) leads to increased mortality rates among renal transplant recipients; however, its effect on allograft survival has not been well studied. The records from the United States Renal Data System and the United Network for Organ Sharing from January 1, 1995, through December 31, 2002, were examined in this retrospective study. The outcome variables were allograft survival time and recipient survival time. The primary variable of interest was CVD, defined as the presence of at least one of the following: cardiac arrest, myocardial infarction, dysrhythmia, congestive heart failure, ischemic heart disease, peripheral vascular disease, and unstable angina. The Cox models were adjusted for potential confounding factors. Of the 105,181 patients in the data set, 20,371 had a diagnosis of CVD. The presence of CVD had an adverse effect on allograft survival time (HR 1.12, p < 0.001) and recipient survival time (HR 1.41, p < 0.001). Among the subcategories, congestive heart failure (HR 1.14, p < 0.005) and dysrhythmia (HR 1.26, p < 0.05) had adverse effects on allograft survival time. In addition to increasing mortality rates, CVD at the time of end-stage renal disease onset is also a significant risk factor for renal allograft failure. Further research is needed to evaluate the role of specific forms of CVD in allograft and recipient outcome.

Cardiovascular complications after renal transplantation and their prevention

By the time of renal transplantation, end-stage renal disease patients have a huge burden of cardiovascular disease (CVD) and are heavily saturated with atherosclerotic risk factors. Worsening of preexisting risk factors or new CVD risk factors may develop in the posttransplant period consequent in part to the diabetogenic and atherogenic potential of immunosuppressive drugs. The annual risk of a fatal or non-fatal CVD event of 3.5 to 5% in kidney transplant recipients is 50-fold higher than the general population. Renal allograft dysfunction, proteinuria, anemia, moderate hyperhomocysteinemia and elevated serum C-reactive protein concentrations, each dependently confer greater risk of CVD morbidity and mortality in the posttransplant period. Long-term care of renal transplant recipients should programmatically incorporate the recommendations of the National Kidney Foundation Working Groups and European Best Practice Guidelines Expert Group on Renal Transplantations into the management of hypertension, dyslipidemia, smoking, and posttransplant diabetes mellitus. Timely utilization of coronary revascularization procedures should be undertaken as these treatments are equally effective in the kidney transplant population.

Normalization of multiple hemostatic abnormalities in uremic type 1 diabetic patients after kidney-pancreas transplantation

To evaluate the effects of kidney-pancreas transplantation on hemostatic abnormalities in uremic type 1 diabetic patients, we conducted a cross-sectional study involving 12 type 1 diabetic patients, 30 uremic type 1 diabetic patients, 27 uremic type 1 diabetic patients who had a kidney-pancreas transplant, 12 uremic type 1 diabetic patients who had a kidney-alone transplant, and 13 healthy control subjects. We evaluated platelet and clotting system. Platelets in the group of uremic type 1 diabetic patients were significantly larger than platelets in the other groups. Resting calcium levels were significantly higher in the uremic type 1 diabetic patients and uremic type 1 diabetic patients who had a kidney-alone transplant than in the type 1 diabetic patients who had a kidney-pancreas transplant and control subjects. CD41 expression was significantly reduced in platelets from the uremic type 1 diabetic patients compared with the other groups. Levels of hypercoagulability markers in the type 1 diabetic patients who had a kidney-pancreas transplant and, to a lesser extent, the uremic type 1 diabetic patients who had a kidney-alone transplant but not the uremic type 1 diabetic patients were similar to those of the control subjects. A reduction in natural anticoagulants was evident in the uremic type 1 diabetic patients, whereas near-normal values were observed in the type 1 diabetic patients who had a kidney-pancreas transplant and uremic type 1 diabetic patients who had a kidney-alone transplant. Hemostatic abnormalities were not observed in type 1 diabetic patients who had a kidney-pancreas transplant. This finding might explain the lower cardiovascular death rate observed in type 1 diabetic patients who had a kidney-pancreas transplant compared with uremic type 1 diabetic patients who had a kidney-alone transplant or uremic type 1 diabetic patients.

Impact of kidney transplantation on the progression of cardiovascular disease

Kidney transplantation, of all the treatment modalities for end-stage renal disease, affords the greatest potential for prolonged survival and improved quality of life. Great strides in immunosuppressant therapy have improved graft survival and forced clinicians to consider other health-care needs of kidney transplant recipients. Chief among these needs is the prevention and treatment of cardiovascular disease. Cardiovascular disease is the most common cause of death among patients with a working renal allograft. Because therapies for primary and secondary prevention are successful in the general population, transplant clinicians are increasingly focused on preventing or limiting the progression of cardiovascular disease. Initiation of aggressive management of conventional atherosclerotic risk factors and uremia-related risk factors, ideally during the early stages of chronic kidney disease (CKD) or after kidney transplantation, and efforts to delay the progression of kidney disease will hopefully reduce the cardiovascular burden in transplant recipients.

Comparison of microbial findings and resistance to antibiotics between transplant patients, patients on hemodialysis, and other patients with the diabetic foot

Infectious complications of the diabetic foot may be influenced by impaired renal function and by immunosuppression therapy.

AIMS

To assess differences in microbial findings and resistance to antibiotics between transplant recipients, hemodialysis patients, and other patients with the diabetic foot.

METHODS

207 patients treated in the foot clinic for diabetic ulcers from 12/1998 to 12/1999 were included into this retrospective study. Patients were divided into three groups (transplant, dialysis, and other patients). Occurrence of individual bacterial species and resistance to antibiotics was compared between study groups.

RESULTS

Study groups did not differ significantly in ulcer grades defined by the Wagner classification or in the mean number of pathogens per patient. The prevalence of individual microorganisms did not differ between the study groups. However, the study groups differed significantly in the occurrence of microbial resistance to antibiotics. Transplant patients had more frequently Staphylococcus aureus resistant to oxacillin (P<.01), imipenem (P<.01), co-trimoxazole (P<.01), Enterococcus species resistant to ampicillin (P<.01), piperacillin (P<.01), and dialysis patients had more frequently Pseudomonas species resistant to piperacillin (P<.05) and cefpirom (P<.05) in comparison with the other two groups.

CONCLUSIONS

Transplant patients had significantly more resistant microorganisms in comparison with dialysis and other patients with the diabetic foot. Empiric antibiotic selection based on general population data should be modified in transplant patients with diabetic foot according to actual susceptibility to antibacterial drugs.

Infrainguinal revascularization after renal transplantation

BACKGROUND

Although evidence suggests that end-stage renal disease is associated with poor limb salvage and patient survival after arterial revascularization, little is known about the effect of renal transplantation. We analyzed the outcome in patients with renal transplants who underwent infrainguinal bypass procedures.

METHODS

Data prospectively entered into our vascular registry were reviewed for all patients who underwent lower extremity bypass procedures from January 1, 1990, through January 31, 2002. Sixty patients were identified who had a functioning renal allograft at infrainguinal revascularization. Kaplan-Meier survival curves were generated for limb salvage, patency, and patient survival and were compared with the Mantel-Cox log- rank test.

RESULTS

Sixty patients (40 men, 20 women; mean age, 47.1 years) underwent 76 bypass procedures in 71 limbs. Preoperative demographic data included diabetes (59 of 60 patients, 98.3%), coronary artery disease (26 of 60 patients, 43.3%), and preoperative serum creatinine concentration (SCr) greater than 2.0 mg/dL (9 of 60 patients, 11.7%). Mean follow-up was 25.1 months. Overall major complication rate was 11.8%, and 30-day mortality rate was 1.3%. Survival was 93.3% at 1 year and 66.6% at 5 years. Limb salvage was 87% at 1 year and 78% at 5 years. Primary graft patency was 78% at 1 year and 44% at 5 years. Preoperative SCr less than or equal to 2.0 mg/dL was associated with improved overall patient survival (5-year survival, 73.4% vs 37.5%; P =.01, log-rank test). Limb salvage and patency rates were not significantly affected by preoperative SCr greater than 2.0 mg/dL.

CONCLUSIONS

Lower extremity bypass can be performed safely and effectively in patients who have undergone renal transplantation. However, the importance of a well-functioning renal allograft at surgery is demonstrated by marked improvement in patient survival.

Cigarette smoking: an important renal risk factor - far beyond carcinogenesis

In recent years, it has become apparent that smoking has a negative impact on renal function, being one of the most important remediable renal risk factors. It has been clearly shown that the risk for high-normal urinary albumin excretion and microalbuminuria is increased in smoking compared to non-smoking subjects of the general population. Data from the Multiple Risk Factor Intervention Trial (MRFIT) indicate that at least in males, smoking increases the risk to reach end-stage renal failure. Smoking is particularly "nephrotoxic" in older subjects, subjects with essential hypertension and patients with preexisting renal disease. Of interest, the magnitude of the adverse renal effect of smoking seems to be independent of the underlying renal disease. Death-censored renal graft survival is decreased in smokers, indicating that smoking also damages the renal transplant. Cessation of smoking has been show to reduce the rate of progression of renal failure both in patients with renal disease or a renal transplant. The mechanisms of smoking-induced renal damage are only partly understood and comprise acute hemodynamic (e.g., increase in blood pressure and presumably intraglomerular pressure) and chronic effects (e.g., endothelial cell dysfunction). Renal failure per se leads to an increased cardiovascular risk. The latter is further aggravated by smoking. Particularly survival of smokers with diabetes mellitus on hemodialysis is abysmal. In the present review article the current state of knowledge about the renal risks of smoking is reviewed. It is the aim of the article to point out that smoking not only increases the risk of renal cell carcinoma or uroepithelial cell carcinoma, but also the risk of a faster decline of renal function. The latter is a relatively new negative aspect which has not been widely recognized.