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Christoph A Nienaber

Publications and source records attributed to Christoph A Nienaber.

At least 19 recordsLinked to original sources

Simple risk models to predict surgical mortality in acute type A aortic dissection: the International Registry of Acute Aortic Dissection score.

BACKGROUND: Surgical mortality for acute type A aortic dissection is frequently related to preoperative clinical conditions. We report a predictive score to identify risk of death that may be helpful to assist surgeons who are considering whether to proceed with surgical correction in the case of patients in extreme clinical risk. METHODS: Surgical outcome of 682 patients enrolled in the International Registry of Acute Aortic Dissection from 1996 to 2003 was analyzed. Two different models were used. The initial model included only preoperative variables such as demographics, history, symptoms, signs, and diagnostic methods (model 1). The second model also tested intraoperative hemodynamic and surgical variables (model 2). A bedside risk prediction tool to predict operative mortality in individual patients was developed. RESULTS: The overall in-hospital surgical mortality was 23.9%. Independent preoperative predictors of mortality in model 1 were age greater than 70 years, prior cardiac surgery, hypotension (systolic blood pressure less than 100 mm Hg) or shock at presentation, migrating pain, cardiac tamponade, any pulse deficit, and electrocardiogram with findings of myocardial ischemia or infarction. In model 2, other predictors of surgical death were intraoperative hypotension, a right ventricle dysfunction at surgery, and a necessity to perform coronary revascularization. An independent predictor for favorable surgical outcome was right hemiarch replacement. CONCLUSIONS: Surgery in unstable patients with acute type A aortic dissection can be highly unsuccessful. The International Registry of Acute Aortic Dissection risk models predict in-hospital mortality using a multivariable risk prediction tool, useful for surgeons and patients as they consider their surgical risk and the pros and cons of embarking on high-risk surgery.

Acute Disease↗

Granulocyte-colony-stimulating factor in acute myocardial infarction: future perspectives after FIRSTLINE-AMI and REVIVAL-2.

Granulocyte-colony-stimulating factor (G-CSF) seems to have direct cardioprotective effects related to mobilization of autologous bone-marrow mononuclear CD34(+) cells. These properties have attracted the attention of researchers investigating new therapeutic strategies for acute myocardial infarction. The role of G-CSF in bone-marrow cell mobilization removes the need for bone-marrow aspiration and repeated invasive procedures. This factor, coupled with the fact that G-CSF can be administered by noninvasive subcutaneous injection, give this approach a potential advantage over other cell-therapy options. This article is intended to present a concise overview of the current experimental and clinical findings for G-CSF therapy after acute myocardial infarction. In particular, we discuss the conflicting findings from the front-integrated revascularization and stem cell liberation in evolving acute myocardial infarction (FIRSTLINE-AMI) and the Regenerate Vital Myocardium by Vigorous Activation of Bone Marrow Stem Cells (REVIVAL-2) studies.

Cell Movement↗

Future investigations in stem cell activation with granulocyte-colony-stimulating factor after myocardial infarction.

Experimental data indicate that stem cell mobilization with granulocyte colony-stimulating factor (G-CSF) might have potential as a novel therapeutic strategy for acute myocardial infarction. The prospective beneficial effects of G-CSF can be attributed mainly to a direct action on injured myocardium rather than on differentiation of mobilized bone marrow stem cells into cardiac myocytes. This article reviews the evidence for the potential cardioprotective effects of G-CSF and discusses future investigations regarding pharmacologic stem cell activation and mobilization with G-CSF in the setting of acute myocardial infarction.

Animals↗

Long-term survival in patients presenting with type B acute aortic dissection: insights from the International Registry of Acute Aortic Dissection.

BACKGROUND: Follow-up survival studies in patients with acute type B aortic dissection have been restricted to a small number of patients in single centers. We used data from a contemporary registry of acute type B aortic dissection to better understand factors associated with adverse long-term survival. METHODS AND RESULTS: We examined 242 consecutive patients discharged alive with acute type B aortic dissection enrolled in the International Registry of Acute Aortic Dissection (IRAD) between 1996 and 2003. Kaplan-Meier survival curves were constructed, and Cox proportional hazards analysis was performed to identify independent predictors of follow-up mortality. Three-year survival for patients treated medically, surgically, or with endovascular therapy was 77.6+/-6.6%, 82.8+/-18.9%, and 76.2+/-25.2%, respectively (median follow-up 2.3 years, log-rank P=0.61). Independent predictors of follow-up mortality included female gender (hazard ratio [HR],1.99; 95% confidence interval [CI], 1.07 to 3.71; P=0.03), a history of prior aortic aneurysm (HR, 2.17; 95% CI, 1.03 to 4.59; P=0.04), a history of atherosclerosis (HR, 2.48; 95% CI, 1.32 to 4.66; P<0.01), in-hospital renal failure (HR, 2.55; 95% CI, 1.15 to 5.63; P=0.02), pleural effusion on chest radiograph (HR, 2.56; 95% CI, 1.18 to 5.58; P=0.02), and in-hospital hypotension/shock (HR, 12.5; 95% CI, 3.24 to 48.21; P<0.01). CONCLUSIONS: Contemporary follow-up mortality in patients who survive to hospital discharge with acute type B aortic dissection is high, approaching 1 in every 4 patients at 3 years. Current treatment and follow-up surveillance require further study to better understand and optimize care for patients with this complex disease.

Acute Disease↗

Acute limb ischemia associated with type B aortic dissection: clinical relevance and therapy.

BACKGROUND: The goal of the current study is to characterize the presentation, therapy, and outcomes of acute limb ischemia (ALI) associated with type B aortic dissection (AoD). METHODS: The prospective/retrospective International Registry for Acute Aortic Dissection (IRAD) database and a single institutional database were queried for all patients with type B AoD from 1996 to 2002. Univariate and multivariate statistics were used to delineate factors associated with morbidity and mortality outcomes. RESULTS: According to the IRAD data (n = 458), the mean age of patients was 64 years, and 70% were men. The overall mortality was 12%; of these, 6% had ALI. Pulse (3-fold) and neurologic deficits (5-fold) were more common in those with ALI (P < .001). Endovascular, but not surgical therapy, was more commonly performed in patients with ALI compared with those without ALI (31% vs 10%, P = .004). No difference in age, race, gender, or origin of dissection was observed. ALI was associated with acute renal failure (odds ratio [OR] = 2.7; 95% confidence interval [CI] 1.1-7.1; P = .048) and acute mesenteric ischemia/infarction (OR = 6.9; 95% CI 2.5-20; P < .001). Adjusting for patient characteristics, ALI was associated with death (3.5; 95% CI 1.1-10; P = .02). The single institution analysis revealed similar patient demographics and mortality in 93 AoD patients, of whom 28 had ALI. Aortic fenestration or aorto-iliac stenting was the primary therapy in 93%; surgical bypass was used in 7%. Limb salvage was 93% in those with ALI at a mean of 18 months follow-up. The number of organ systems with malperfusion was 2-fold higher at aortography than suspected preprocedure (P = .002). By stepwise regression modeling, mortality was greater in those not taking a beta-blocker (OR = 19; 95% CI 3.1-111; P = .001). CONCLUSIONS: ALI secondary to AoD is predictive of death and visceral ischemia. Endovascular therapy confers excellent limb salvage and allows diagnosis of unsuspected visceral ischemia.

Acute Disease↗

Long-term survival in patients presenting with type A acute aortic dissection: insights from the International Registry of Acute Aortic Dissection (IRAD).

BACKGROUND: Earlier studies evaluating long-term survival in type A acute aortic dissection (TA-AAD) have been restricted to a small number of patients in single center experiences. We used data from a contemporary, multi-center international registry of TA-AAD patients to better understand factors associated with long-term survival. METHODS AND RESULTS: We examined 303 consecutive patients with TA-AAD enrolled in the International Registry of Acute Aortic Dissection (IRAD) between 1996 and 2003. We included patients who were discharged alive and had documented clinical follow-up data. Kaplan-Meier survival curves were constructed to depict cumulative survival in patients from date of hospital discharge. Stepwise Cox proportional hazards analysis was performed to identify independent predictors of follow-up mortality. We found that 273 (90.1%) patients had been managed surgically and 30 (9.9%) were managed medically. Patients who were dead at follow-up were more likely to be older (63.9 versus 58.4 years, P=0.007) and to have had previous cardiac surgery (23.9% versus 10.6%, P=0.01). Survival for patients treated with surgery was 96.1%+/-2.4% and 90.5%+/-3.9% at 1 and 3 years versus 88.6%+/-12.2% and 68.7%+/-19.8% without surgery (mean follow-up overall, 2.8 years, log rank P=0.009). Multivariate analysis identified a history of atherosclerosis (relative risk (RR), 2.17; 95% confidence interval [CI], 1.08 to 4.37; P=0.03) and previous cardiac surgery (RR, 2.54; 95% CI, 1.16 to 5.57; P=0.02) as significant, independent predictors of follow-up mortality. CONCLUSIONS: Contemporary 1- and 3-year survival in patients with TA-AAD treated surgically are excellent. Independent predictors of survival during the follow-up period do not appear to be influenced by in-hospital risks but rather preexisting comorbidities.

Acute Disease↗

Role and results of surgery in acute type B aortic dissection: insights from the International Registry of Acute Aortic Dissection (IRAD).

BACKGROUND: The clinical profiles and outcomes of patients treated surgically for acute type B aortic dissection (ABAD) are often reported for those in small series or for those cared for at a single institution over a long time period, during which a continuous evolution in techniques has occurred. Accordingly, we sought to evaluate the clinical features and surgical results of patients enrolled in the International Registry of Acute Aortic Dissection by identifying primary factors that influenced surgical outcome and estimating average surgical mortality for ABAD in the current era. METHODS AND RESULTS: A comprehensive analysis of 290 clinical variables and their relation to surgical outcomes for 82 patients who required surgery for ABAD (from a population of 1256 patients; mean+/-SD age, 60.6+/-15.0 years; 82.9% male) and who were enrolled in the International Registry of Acute Aortic Dissection was performed. The overall in-hospital mortality was 29.3%. Factors associated with increased surgical mortality based on univariate analysis were preoperative coma or altered consciousness, partial thrombosis of the false lumen, evidence of periaortic hematoma on diagnostic imaging, descending aortic diameter >6 cm, right ventricle dysfunction at surgery, and shorter time from the onset of symptoms to surgery. Factors associated with favorable outcomes included radiating pain, normotension at surgery (systolic blood pressure 100 to 149 mm Hg), and reduced hypothermic circulatory arrest time. The 2 independent predictors of surgical mortality were age >70 years (odds ratio, 4.32; 95% confidence interval, 1.30 to 14.34) and preoperative shock/hypotension (odds ratio, 6.05; 95% confidence interval, 1.12 to 32.49). CONCLUSIONS: The present study provides insights into current-day clinical profiles and surgical outcomes of ABAD. Knowledge about different preoperative clinical conditions may help surgeons in making treatment decisions among these high-risk patients.

Acute Disease↗

Influence of the atrio-ventricular delay optimization on the intra left ventricular delay in Cardiac Resynchronization Therapy.

BACKGROUND: Cardiac Resynchronization Therapy (CRT) leads to a reduction of left-ventricular dyssynchrony and an acute and sustained hemodynamic improvement in patients with chronic heart failure. Furthermore, an optimized AV-delay leads to an improved myocardial performance in pacemaker patients. The focus of this study is to investigate the acute effect of an optimized AV-delay on parameters of dyssynchrony in CRT patients. METHOD: 11 chronic heart failure patients with CRT who were on stable medication were included in this study. The optimal AV-delay was defined according to the method of Ismer (mitral inflow and trans-oesophageal lead). Dyssynchrony was assessed echocardiographically at three different settings: AVDOPT; AVDOPT-50 ms and AVDOPT+50 ms. Echocardiographic assessment included 2D- and M-mode echo for the assessment of volumes and hemodynamic parameters (CI, SV) and LVEF and tissue Doppler echo (strain, strain rate, Tissue Synchronisation Imaging (TSI) and myocardial velocities in the basal segments) RESULTS: The AVDOPT in the VDD mode (atrially triggered) was 105.5 +/- 38.1 ms and the AVDOPT in the DDD mode (atrially paced) was 186.9 +/- 52.9 ms. Intra-individually, the highest LVEF was measured at AVDOPT. The LVEF at AVDOPT was significantly higher than in the AVDOPT-50 setting (p = 0.03). However, none of the parameters of dyssynchrony changed significantly in the three settings. CONCLUSION: An optimized AV delay in CRT patients acutely leads to an improved systolic left ventricular ejection fraction without improving dyssynchrony.

Atrioventricular Node↗

Thoracic aorta endografts: variations in practice among medical specialists.

BACKGROUND: Endovascular stent-graft placement is emerging as a novel treatment option for patients with diseases of the descending thoracic aorta. However, currently no consensus guidelines exist to direct uniformity in stent-graft procedures as well as for pre- and postprocedural patient management, unlike that for the management of other cardiovascular disorder. Accordingly, the aim of the present survey was to assess variations in thoracic aortic stent-graft practice among different subspecialties in Germany. METHODS: An interdisciplinary questionnaire survey was conducted among 206 departments of vascular surgery, radiology, cardiology, and cardiothoracic surgery in Germany that actively performed aortic stent-graft placement. Data on preoperative procedure planning, logistics, practical/technical issues of stent-graft placement, and postoperative patient management were evaluated using a standardized, self-administered questionnaire comprising 29 items. Responses were tabulated for analysis. RESULTS: Of a total of 206 questionnaires, 184 (89.3%) were returned with 71 (38.5%) centers reporting to have performed thoracic aortic stent-graft placement (total number of procedures 2,267) through 1997 and 2003. The average number of stent-graft procedures per year was 7.4 (25-75% percentile, 2.05-10.75) at participating sites, with 49% of the respondents reporting <5 procedures per year. Treatment of thoracic aortic aneurysms was the predominant indication for stent-graft placement, followed by type B-dissection. As anticipated, marked variability existed among the different medical specialties performing stent-graft procedures with respect to all aspects of the procedures including indication for treatment, choice of preoperative and intraoperative imaging modalities, technical equipment and perioperative management. The only consistent agreement was on the need for lifelong follow-up after stent-graft placement, with CT being the preferred imaging technique (90% of centers). CONCLUSION: The present survey documents an increasing adoption of endovascular stent-graft placement for patients with diseases of the descending thoracic aorta in Germany. Despite this, there is a lack of consensus among the different medical specialties performing stent-graft placement with respect to indications and technical execution of stent-grafting. Our data supports the need for consensus practice guidelines endorsed by medical professional societies for stent-graft procedure to standardize the growing number of thoracic stent graft procedures.

Angioplasty↗

Cell-based therapies after myocardial injury.

Recent translational research into the emerging field of cardiac cell therapy has paved the way for novel clinical treatment strategies. However, neither the ideal source and type of cell nor the critical quantity and mode of application have yet been defined. In patients who have undergone acute myocardial infarction, several cell-based approaches are currently being evaluated, such as intracoronary delivery of autologous mononuclear bone marrow cells or enriched hematopoietic progenitor cell products; systemic cytokine stimulation with release of bone marrow progenitor cells into the systemic circulation; and both intravenous and intracoronary delivery of allogenic marrow stroma cell-derived cells. There are potentially encouraging data for each of these strategies, based to date on small cohorts with conflicting or equivocal recovery of function. Taken together, it is too early to consider cell therapy for heart disease to be effective. Future setbacks are likely, but both clinicians and basic scientists will eventually introduce more potent cell-based strategies into the clinical arena.

Journal Article↗

Predictors of death or myocardial infarction during follow-up after coronary stenting with the sirolimus-eluting stent. Results from the prospective multicenter German Cypher Stent Registry.

BACKGROUND: Drug-eluting coronary stents are the most recent "breakthrough" technology in interventional cardiology. Whereas risk factors influencing restenosis and need for target vessel revascularization are well known, risk factors for dying or developing a myocardial infarction (MI) after drug-eluting coronary stent implantation need to be evaluated yet. METHODS: We evaluated data from the German Cypher Stent Registry. RESULTS: From April 2002 to December 2004, 7445 patients at 122 hospitals, who received at least one sirolimus-eluting stent during percutaneous coronary intervention, were included. Complete follow-up at a median of 6.6 months (quartiles 6.1-8.1 months) was available in 6755 patients (91%). Death occurred in 1.8% (120/6755) of patients, nonfatal MI in 2.3% (156/6635), and death or MI in 4.1% (276/6755) of patients. Independent predictors of death or MI were initial presentation with ST-elevation MI or non-ST-elevation MI (OR [odds ratio] 2.21, 95% CI 1.66-2.95, P < .0001), cardiogenic shock (OR 3.05, 95% CI 1.67-5.55, P = .0003), renal insufficiency (OR 1.74, 95% CI 1.24-2.44, P = .0017), reduced left ventricular function (OR 1.74, 95% CI 1.21-2.50, P = .0027), age (per decade) (OR 1.19, 95% CI 1.05-1.36, P = .0058), diabetes mellitus (OR 1.39, 95% CI 1.05-1.84, P = .0183), 3-vessel disease (OR 1.32, 95% CI 0.99-1.77, P = .043), and prior MI (OR 1.35, 95% CI 1.01-1.80, P = .0468), whereas interventional and lesion characteristics showed no significant association. CONCLUSIONS: These results demonstrate that the most powerful predictors of death or MI after sirolimus-eluting stent implantation during percutaneous coronary intervention are presentation with an acute coronary syndrome, impaired left ventricular ejection fraction, and conventional risk factors for coronary heart disease. Interventional and lesion characteristics do not play a major role.

Acute Disease↗

Results of endovascular repair of the thoracic aorta with the Talent Thoracic stent graft: the Talent Thoracic Retrospective Registry.

BACKGROUND: Endovascular treatment of thoracic aortic diseases demonstrated low perioperative morbidity and mortality when compared with conventional open repair. Long-term effectiveness of this minimally invasive technique remains to be proven. The Talent Thoracic Retrospective Registry was designed to evaluate the impact of this therapy on patients treated in 7 major European referral centers over an 8-year period. METHODS: Data from 457 consecutive patients (113 emergency and 344 elective cases) who underwent endovascular thoracic aortic repair with the Medtronic Talent Thoracic stent graft (Medtronic/AVE, Santa Rosa, Calif) were collected. Follow-up analysis (24 +/- 19.4 months, range 1-85.1 months) was based on clinical and imaging findings, including all adverse events. To ensure consistency of data interpretation and event reporting, one physician reviewed all adverse events and deaths for the whole cohort of patients. In the case of discrepancies, the treating physicians were queried. FINDINGS: Among 422 patients who survived the interventional procedure (in-hospital mortality 5%, 23 patients), mortality during follow-up was 8.5% (36 patients), and in 11 of them the death was related to the aortic disease. Persistent endoleak was reported at imaging follow-up in 64 cases: 44 were primary (9.6%) and 21 occurred during follow-up (4.9%). Seven patients with persistent endoleak had aortic rupture during follow-up, at a variable time from 40 days to 35 months, and all subsequently died. A minor incidence of migration of the stent graft (7 cases), graft fabric alteration (2 cases), and modular disconnection (3 cases) was observed at imaging. Kaplan-Meier overall survival estimate at 1 year was 90.97%, at 3 years was 85.36%, and at 5 years was 77.49%. At the same intervals, freedom from a second procedure (either open conversion or endovascular) was 92.45%, 81.3%, and 70.0%, respectively. CONCLUSION: Endovascular treatment for thoracic aortic disease with the Talent stent graft is associated with low early morbidity and mortality rates also for patients who are at high risk and treated on an emergency basis. Follow-up data indicate a substantial durability of the procedure with a high freedom from related death and secondary interventions.

Adult↗

Effects of granulocyte-colony-stimulating factor on mobilization of bone-marrow-derived stem cells after myocardial infarction in humans.

Recent experimental studies have shown that granulocyte-colony-stimulating factor (G-CSF) enhanced cardiac function after infarction. The concept of direct cytokine or cell-mediated effects on postischemic myocardial function was tested in the setting of human myocardial infarction subjected to percutaneous coronary intervention. In the FIRSTLINE-AMI study 50 consecutive patients with first ST-elevation myocardial infarction were randomly assigned to receive either 10 microg/kg G-CSF for 6 days after percutaneous coronary intervention in addition to standard medication, or standard care alone. G-CSF administration led to mobilization of CD34(+) mononuclear stem cells (MNC(CD34+)), with a 20-fold increase to 64 +/- 37 MNC(CD34+)/microl at day 6 without significant associated changes in rheology, blood viscosity or inflammatory reaction, or any major adverse effects. At 4 months the G-CSF group showed improved left ventricular ejection fraction of 54 +/- 8% versus 48 +/- 4% at baseline (P <0.001), and no evidence of left ventricular end-diastolic remodeling, with a diameter of 55 +/- 5 mm and improved segmental wall thickening (P <0.001); conversely, in control patients left ventricular ejection fraction was 43 +/- 5% at 4 months (P <0.001), with increased left ventricular end-diastolic dimension of 58 +/- 4 mm (P <0.001), and no segmental wall thickening. In conclusion, the FIRSTLINE-AMI study showed that G-CSF administration and mobilization of MNC(CD34+) after reperfusion of infarcted myocardium may offer a pragmatic strategy for preservation of human myocardium and prevention of remodeling without evidence of aggravated atherosclerosis.

Abciximab↗

Iliac anastomotic stenting with a biodegradable poly-L-lactide stent: a preliminary study after 1 and 6 weeks.

PURPOSE: To assess the technical feasibility, thrombogenicity, and biocompatibility of a new biodegradable poly-L-lactic acid (PLLA) anastomotic stent. METHODS: A polytetrafluoroethylene bifurcated graft was implanted in 17 pigs through a midline abdominal incision. After transverse graft incision, 17 316L stainless steel stents and 17 PLLA stents were randomly implanted at both iliac anastomotic sites and deployed with a 6-mm balloon under direct vision without angiography. Intended follow-up was 1 week in 6 pigs receiving oral acetylsalicylic acid (ASA) and in 7 pigs receiving ASA/clopidogrel; 4 pigs receiving ASA/clopidogrel were followed for 6 weeks. At the end of the study, the segments containing the stents were surgically explanted and processed for histology to measure the mean luminal diameter, intimal thickness, and the vascular injury and inflammation scores. RESULTS: Initial technical success of stent placement was achieved in all animals without rupture of the suture. Two pigs died (unrelated to the stent) at 3 days after operation (1 in groups A and B). At 1 week, all PLLA stents showed thrombotic occlusion with the use of ASA alone. In contrast, all PLLA stents remained patent with concurrent administration of ASA/clopidogrel. All metal stents were patent regardless of the antiplatelet regimen. The mean luminal diameter of patent PLLA stents (4.13+/-0.17 mm) was comparable to metal stents (4.27+/-0.35 mm, p=0.78) at 1 week, but significantly diminished at 6 weeks (3.21+/-0.44 versus 4.19+/-0.18 mm, p=0.005). Histological analysis showed no signs of excessive recoil. PLLA stents induced a higher inflammation score (1.79+/-0.56) and more intimal hyperplasia (0.34+/-0.11 mm) compared to metal stents [1.27+/-0.44 mm (p<0.001) and 0.18+/-0.04 mm (p=0.006), respectively] at 6 weeks. Vascular injury was comparable between PLLA and metal stents. CONCLUSION: Biodegradable PLLA stents showed higher thrombogenicity and reduced patency compared to metal stents during early follow-up. Although ASA and clopidogrel prevented thrombotic occlusion, the increased inflammatory response and neointima formation remain major concerns of PLLA stents. A solution to this problem might be the incorporation of anti-inflammatory drugs into the PLLA stent.

Absorbable Implants↗

Iliac anastomotic stenting with a sirolimus-eluting biodegradable poly-L-lactide stent: a preliminary study after 6 weeks.

PURPOSE: To assess technical feasibility and biocompatibility of a new biodegradable sirolimus-eluting poly-L-lactide (PLLA) vascular anastomotic stent. METHODS: A polytetrafluoroethylene bifurcated graft was implanted in 9 pigs through a midline abdominal incision. After transverse graft limb incision, 6 unloaded PLLAs, 6 sirolimus-loaded PLLAs, and 6 unloaded stainless steel (316L) stents were randomly implanted at both iliac anastomotic sites. Stents were deployed with a 6-mm balloon under direct vision without the use of angiography. Prior to sacrifice after 6 weeks, contrast-enhanced computed tomography (CT) was performed to determine patency of the target vessels. Stented segments were surgically explanted and processed for histology to measure the mean luminal diameter and intimal thickness and to assign vascular injury and inflammation scores. RESULTS: No animals were lost during the study period. All stented graft limbs were patent on CT and histology. At the anastomotic sites and iliac arteries, the mean luminal diameter of SIR-PLLA stents (4.11+/-0.15 and 4.08+/-0.13 mm, respectively) were comparable to metal stents (4.23+/-0.35 and 4.21+/-0.26 mm, respectively), but significantly higher compared to unloaded PLLA stents [3.32+/-0.56 mm (p<0.001) and 3.29+/-0.39 mm (p=0.013), respectively]. At the iliac arteries, the mean intimal thickness was significantly lower with SIR-PLLA stents (0.09+/-0.02 mm) compared to unloaded PLLA stents (0.31+/-0.15 mm, p<0.001) and metal stents (0.19+/-0.04 mm, p=0.004). Vascular injury scores demonstrated only mild vascular trauma for all stents (SIR-PLLA: 0.42+/-0.63, PLLA: 0.51+/-0.62, metal: 0.50+/-0.62). Only mild inflammatory reaction was noted around SIR-PLLA stent struts (1.14+/-0.46), which was comparable to metal stents (1.27+/-0.45) but significantly lower than PLLA stents (1.79+/-0.56, p<0.001). CONCLUSION: SIR-PLLA stents showed comparable luminal diameter compared to metal stents, so incorporating sirolimus could reduce the inflammatory and neointimal response to PLLA stents. These findings need to be assessed with longer follow-up to confirm maintenance of efficacy.

Absorbable Implants↗