The Effect of Immunosuppression on Lower Extremity Arterial Bypass Outcomes

The Double Burden: Deciphering Chronic Limb-Threatening Ischemia in End-Stage Renal Disease

BACKGROUND

Chronic limb-threatening ischemia (CLTI) in patients with end-stage renal disease (ESRD) poses significant challenges in clinical management due to its unique pathology and poor treatment outcomes. This review calls for a tailored classification and risk assessment for these patients to guide better revascularization choices with early minor amputation as a first-line strategy in advanced stages.

METHODS

This review consolidates key findings from recent literature on CLTI in ESRD, focusing on disease mechanisms, treatment options, and patient outcomes. It evaluates the literature to clarify the decision-making process for managing CLTI in ESRD.

RESULTS

CLTI in ESRD patients often results in worse clinical outcomes, such as nonhealing wounds, increased limb loss, and higher mortality rates. While the literature reveals ongoing debates regarding the optimal revascularization method, recent retrospective studies and meta-analyses suggest potential benefits of endovascular treatment (EVT) over open bypass surgery (OB) in reducing mortality and wound complications, with comparable amputation-free survival rates.

CONCLUSIONS

The selection of revascularization methods in ESRD patients with CLTI is complex, necessitating individualized strategies. The importance of early detection and timely intervention is critical to decelerate disease progression and improve revascularization outcomes. There is a shift in these treatment strategies toward less invasive endovascular procedures, acknowledging the limitations these patients face with open revascularization surgeries. Considering early minor amputations after revascularization could prevent worse consequences, reflecting a shift in the approach to managing CLTI in ESRD patients.

Predictive Value of the Naples Prognostic Score on Long-Term Outcomes in Patients with Peripheral Artery Disease Revascularized via Percutaneous Intervention

BACKGROUND

Lower extremity peripheral artery disease (PAD) is the third most common clinical manifestation of atherosclerosis after coronary artery disease and stroke. Despite successful endovascular treatment (EVT), mortality and morbidity rates still remain higher in patients with PAD. Naples prognostic score (NPS) is a novel scoring system, reflects the patient's nutritional and immunological statuses as well as systemic inflammatory responses. In this study, we aimed to investigate the relationship between NPS and long-term outcomes in patients with PAD.

METHODS

The population of this retrospective study consisted of 629 PAD patients who underwent EVT at Kafkas University Hospital between 2020 and 2023. For each patient, the NPS was calculated and then patients were divided into 3 groups based on their NPS. The primary end point of the study was the rate of major adverse cardiovascular (MACEs) and limb events (MALEs), that is, all-cause death or development of critical limb ischemia with consequent amputation.

RESULTS

Of a total of 629 patients, 62 were classified into group 0 (NPS 0), 315 into group 1 (NPS 1 or 2), and 252 into group 2 (NPS 3 or 4). The distribution of patients' baseline characteristics, angiographic features and MACEs and MALEs according to the NPS groups was analyzed. Significant adverse outcomes differences were observed among the 3 groups (P < 0.001). Multivariate logistic regression analysis revealed that age, diabetes mellitus, chronic kidney disease, lowest preprocedure ankle-brachial index, left ventricular ejection fraction and NPS (hazard ratio 1.916, 95% confidence interval [CI] 1.530-2.398, P < 0.001) were independent predictors of MACE whereas diabetes mellitus, presence of previous PAD, hemoglobin level, in-hospital acute thrombotic occlusion and NPS (odds ratio 1.963, 95% CI 1.489-2.588, P < 0.001) were independent predictors of MALE.

CONCLUSIONS

The inflammatory and nutritional state reflected by NPS levels was strongly associated with all-cause mortality and amputation after EVT in patients with PAD. Furthermore, NPS was found to be an independent predictor of these clinical outcomes.

Systemic immunosuppression does not affect revascularization outcomes in patients with chronic limb-threatening ischemia

OBJECTIVE

Many patients with chronic limb-threatening ischemia (CLTI) have additional comorbidities requiring systemic immunosuppression. Few studies have analyzed whether these medications may inhibit graft integration and effectiveness, or conversely, whether they may prevent inflammation and/or restenosis. Therefore, our study aim was to examine the effect of systemic immunosuppression vs no immunosuppression on outcomes after any first-time lower extremity revascularization for CLTI.

METHODS

We identified all patients undergoing first-time infrainguinal bypass graft (BPG) or percutaneous transluminal angioplasty with or without stenting (PTA/S) for CLTI at our institution between 2005 and 2014. Patients were stratified by procedure type and immunosuppression status, defined as ≥6 weeks of any systemic immunosuppression therapy ongoing at the time of intervention. Immunosuppression vs nonimmunosuppression were the primary comparison groups in our analyses. Primary outcomes included perioperative complications, reintervention, primary patency, and limb salvage, with Kaplan-Meier and Cox proportional hazard models used for univariate and multivariate analyses, respectively.

RESULTS

Among 1312 patients, 667 (51%) underwent BPG and 651 (49%) underwent PTA/S, of whom 65 (10%) and 95 (15%) were on systemic immunosuppression therapy, respectively. Whether assessing BPG or PTA/S patients, there were no differences noted in perioperative outcomes, including perioperative mortality, myocardial infarction, stroke, hematoma, or surgical site infection (P > .05). For BPG patients, Kaplan-Meier analysis and log-rank testing demonstrated no significant difference in three-year reintervention (37% vs 33% [control]; P = .75), major amputation (27% vs 15%; P = .64), or primary patency (72% vs 66%; P = .35) rates. Multivariate analysis via Cox regression confirmed these findings (immunosuppression hazard ratio [HR] for reintervention, 0.95; 95% CI, 0.56-1.60; P = .85; for major amputation, HR, 1.44; 95% CI, 0.70-2.96; P = .32; and for primary patency. HR, 0.97; 95% CI, 0.69-1.38; P = .88). For PTA/S patients, univariate analysis revealed similar rates of reintervention (37% vs 39% [control]; P = .57) and primary patency (59% vs 63%; P = .21); however, immunosuppressed patients had higher rates of major amputation (23% vs 12%; P = .01). After using Cox regression to adjust for baseline demographics, as well as operative and anatomic characteristics, immunosuppression was not associated with any differences in reintervention (HR, 0.75; 95% CI, 0.49-1.16; P = .20), major amputation (HR, 1.46; 95% CI, 0.81-2.62; P = .20), or primary patency (HR, 0.84; 95% CI, 0.59-1.19; P = .32). Sensitivity analyses for the differences in makeup of immunosuppression regimens (steroids vs other classes) did not alter the interpretation of any findings in either BPG or PTA/S cohorts.

CONCLUSIONS

Our findings demonstrate that patients with chronic systemic immunosuppression, as compared with those who are not immunosuppressed, does not have a significant effect on late outcomes after lower extremity revascularization, as measured by primary patency, reintervention, or major amputation.

Outcomes of Infrapopliteal Bypass for Chronic Limb-Threatening Ischemia are Worse in Renal Transplant Patients than in Hemodialysis-Dependent Patients

BACKGROUND

Comparisons of distal bypass outcomes between hemodialysis-dependent (HD) and renal transplant (RT) patients have been reported, but the influences of immunosuppressive therapy on the outcomes remain unclear because of the limited number of RT patients who underwent distal bypass or cohort heterogenicity. We compared outcomes of distal bypass for chronic limb-threatening ischemia (CLTI) with homogenous ischemic limb pathology.

METHODS

Between January 2014 and December 2019, we performed 334 infrapopliteal bypass procedures using vein grafts for 275 consecutive CLTI patients with tissue loss. Among them, there were 130 HD patients (47.3%) (163 limbs) and 11 RT patients (4%) (15 limbs), and 30-day mortality, 5-year primary and secondary patency (PP and SP), limb salvage (LS), amputation-free survival rates, and wound healing (WH) status were compared between the HD and RT patient groups.

RESULTS

Nine HD patients died within 30 days after surgery (7%), whereas no deaths were observed among the RT patients. Five-year PP and SP rates in the RT group 39% and 41%, which were significantly worse compared to 64% and 82% in the HD group (P < 0.01). Unsuccessful rate of revision surgery including hemodynamically failed grafts after revision reached over 80% in the RT group, which was technically unfeasible pathology for graft salvage (vs. 3% in the HD group), and WH, and LS rates were significantly worse in the RT group.

CONCLUSIONS

In comparison with HD patients, RT patients showed a lower LS rate for CLTI. The lower LS rate was associated with a lower SP rate, which was caused by disease progression of distal arteries in the foot.

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.

Outcomes of Infrainguinal Lower Extremity Bypass Are Superior in Kidney Transplant Recipients Than Patients with Dialysis

Patients with end-stage renal disease (ESRD) whether on dialysis therapy (DT) or who received a kidney transplant (KT) have previously shown unfavorable surgical outcomes. Little is known about the comparative efficacy and durability of lower extremity bypass (LEB) in those patients. The Vascular Quality Initiative database was explored to identify DT or KT recipients (2003-2016) who had LEB. We included 1,714 bypass procedures; DT: 1,512 (88.2%). Primary patency (PP) at 2 year was comparable between KT and DT groups (PP [95% confidence interval {CI}]: 77.0% [69.7%-82.8%] vs. 80.5% [77.8%-82.9%]; P = 0.212), and the risk-adjusted hazard was similar (adjusted hazard ratio [aHR] [95% CI]: 0.89 [0.61-1.30]; P = 0.540). Amputation-free survival (AFS) at 2 year was more favorable in KT group (AFS [95% CI]: 73.1% [66.3%-78.8%] vs. 48.0% [45.4%-50.6%]; P < 0.001), (aHR [95% CI]: 2.29 [1.62-3.23]; P < 0.001). Patients on DT exhibited a higher risk of mortality than KT recipients (aHR [95% CI]: 2.94 [2.07-4.17]; P < 0.001). This study demonstrated superior limb outcomes in KT recipients than patients on DT after LEB. Despite the comparable PP, the risk of amputation or death was doubled in patients on DT compared with KT recipients. Because both groups were similar in several baseline characteristics, the difference in outcome is likely driven by the positive effect of KT on the physiological milieu of these patients.

Unique aspects of peripheral artery disease in patients with chronic kidney disease

Peripheral artery disease (PAD) represents a major health care burden. Despite the advent of screening and interventional procedures, the long-term clinical outcomes remain suboptimal, especially in patients with chronic kidney disease (CKD). While CKD and PAD share common predisposing factors, emerging studies indicate that their co-existence is not merely an association; instead, CKD represents a strong, independent risk factor for PAD. These findings implicate CKD-specific mediators of PAD that remain incompletely understood. Moreover, there is a need to understand the mechanisms underlying poor outcomes after interventions for PAD in CKD. This review discusses unique clinical aspects of PAD in patients with CKD, including high prevalence and worse outcomes after vascular interventions and the influence of renal allograft transplantation. In doing so, it also highlights underappreciated aspects of PAD in patients with CKD, such as disparities in revascularization and higher peri-procedural mortality. While previous reviews have discussed general mechanisms of PAD pathogenesis, focusing on PAD in CKD, this review underscores a need to probe for CKD-specific pathogenic pathways that may unravel novel biomarkers and therapeutic targets in PAD and ultimately improve the risk stratification and management of patients with CKD and PAD.

Infrainguinal bypass surgery outcomes are worse in hemodialysis patients compared with patients with renal transplants

OBJECTIVE

Studies of infrainguinal bypass surgery (IBS) in patients with end-stage renal disease have focused on hemodialysis (HD) patients. Little is known of the applicability of their outcomes to patients with renal transplants (RTs). In this study, we sought to compare perioperative and long-term outcomes of IBS in a large population-based cohort of HD and RT patients.

METHODS

A retrospective review of all HD and RT patients who underwent IBS between January 2007 and December 2011 in the U.S. Renal Data System was performed. Univariable, Kaplan-Meier, multivariable logistic, and Cox regression analyses were employed to evaluate 30-day postoperative (graft failure, limb loss, conduit infection, death) and long-term (primary patency [PP], primary assisted patency [PAP], secondary patency [SP], limb salvage, mortality) outcomes.

RESULTS

There were 10,787 IBSs performed in 9739 (90%) HD patients and 1048 (10%) RT patients who presented predominantly with critical limb ischemia (72%). Bypass configurations were femoral-popliteal (48%), femoral-tibial (34%), and popliteal-tibial (18%). Comparing HD vs RT patients, PP, PAP, and SP were 18% vs 33%, 23% vs 38%, and 30% vs 48%, respectively, at 5 years among autogenous conduit recipients (all P < .001) and 20% vs 28% (P = .02), 23% vs 31% (P = .02), and 33% vs 53% (P < .001) among prosthetic conduit recipients. Limb salvage and patient survival were 39% vs 56% and 19% vs 48%, respectively, at 5 years (all P < .001). Risk-adjusted analyses demonstrated higher PP (adjusted hazard ratio [aHR], 1.32; 95% confidence interval [CI], 1.20-1.45; P < .001), PAP (aHR, 1.32; 95% CI, 1.19-1.45; P < .001), SP (aHR, 1.47; 95% CI, 1.31-1.65; P < .001), limb salvage (aHR, 1.48; 95% CI, 1.30-1.67; P < .001), and patient survival (aHR, 2.42; 95% CI, 2.17-2.71; P < .001) for RT compared with HD patients.

CONCLUSIONS

The HD-dependent state is associated with elevated bypass and patient-level risks after IBS compared with patients with RTs. These results show that the benefits of renal transplantation likely extend to infrainguinal bypass-specific outcomes. The estimates of risk reported herein should inform the patient's and provider's expectations at the point of care.

Reconstructive surgery in immunocompromised patients: evaluation and therapy

Background: An increasing number of patients undergoing reconstructive surgery are immunocompromised due to different reasons and different medical treatments. Some of the used immunosuppressive drugs may affect the process of wound healing and thereby, impair the long-term success of surgical treatment. Therefore, this retrospective analysis aimed at the evaluation of the perioperative treatment and surgical outcome of immunocompromised patients undergoing different reconstructive procedures.

Methods: A retrospective review was performed of 8 immunocompromised patients with different primary diseases who needed reconstructive surgery: 2 patients with non-Hodgkin lymphoma, 1 patient with an acute myeloid leukemia, 1 patient with colitis ulcerosa, 1 patient with liver cirrhosis, 1 patient with chronic polyarthritis, and 2 patients with malignant melanoma.

Results: In 7 of our 8 presented cases, multiple operations with wound debridements have been necessary to optimize the granulation of the wound bed before reconstructive surgery. 3 out of these 7 patients required further operations due to wound dehiscence or necrosis, with 2 of them as a result of increased immunosuppressive therapy. 5 out of 8 patients needed no further surgical treatment.

Conclusions: Both the perioperative drug therapy and the reconstructive surgery concept need to be determined carefully in each individual case of the immunocompromised patients. Thus, the appropriate point in time of operation to achieve the best possible wound healing as well as the complexity of the procedure will require the consideration of a ‘less is more’ strategy in selected cases.

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.