Chris Bakoyiannis

Fenestrated and Branched Endografts for the Treatment of Thoracoabdominal Aortic Aneurysms: A Systematic Review

Purpose: To offer a critical review of the current literature on the use of fenestrated and branched stent-grafts in patients with thoracoabdominal aortic aneurysms (TAAA). Methods: A thorough search of the English-language literature published between January 2000 and September 2009 identified reports of endovascular procedures using fenestrated and/or branched endografts as the intended repair strategy in patients with TAAA. Studies were selected based on specific inclusion criteria: (1) >3 high-risk patients with preoperative diagnosis of TAAA, (2) the intended treatment strategy was an endovascular repair using a fenestrated or branched endograft or both, and (3) patient demographics and outcome data (technical success rate, 30-day mortality, and follow-up length) were clearly stated. From 47 articles initially identified, 7 studies were included in the statistical analysis encompassing 155 patients (mean age 74.4 years, range 41–86) with TAAA averaging 69.2 mm in diameter. The mean follow-up was 11.8 months, and the majority of patients had Crawford type IV aneurysms. Outcome measures of eligible studies were tabulated and then analyzed cumulatively. Results: Technical success was achieved in 94.2% (n = 146) of the 155 patients. Twenty-three (18.4%) primary endoleaks were reported. The 30-day mortality was 7.1% (n = 11), while the 1-year survival rate was 82.6% (n = 128). Three (1.9%) patients developed permanent paraplegia and 2 (1.3%) developed permanent paraparesis; renal failure was reported in 9 (5.8%). Overall follow-up mortality was 16.1% (n=25). Conclusion: Endovascular treatment with fenestrated or/and branched stent-grafts is a new therapeutic option with encouraging results for patients considered unfit for conventional open repair. However, prolonged follow-up studies are needed in order to draw robust conclusions.

The effects of endogenous and exogenous androgens on cardiovascular disease risk factors and progression

Cardiovascular disease incidence rates have long been known to significantly differ between the two sexes. Estrogens alone fail to explain this phenomenon, bringing an increasing amount of attention to the role of androgens. Contrary to what was initially hypothesized, androgens seem to have an overall cardioprotective effect, especially in men. Recent studies and published data continue to support this notion displaying a consistent inverse correlation with atherosclerosis progression and cardiovascular disease both in regressive and prospective study models. Clinical studies have also revealed what seems to be a differential androgenic effect on various cardiovascular risk factors between men and women. Further insight indicates that in order to avoid confusion it may be also preferable to separately examine the effects of endogenous androgen levels from exogenous testosterone administration, as well as discern the differential results of low to normal and supraphysiological administration doses. This review summarizes old and recent data according to the above distinctions, in an attempt to further our understanding of the role of androgens in cardiovascular disease.

Novel Biomarkers of Abdominal Aortic Aneurysm Disease: Identifying Gaps and Dispelling Misperceptions

Abdominal aortic aneurysm (AAA) is a prevalent and potentially life-threatening disease. Early detection by screening programs and subsequent surveillance has been shown to be effective at reducing the risk of mortality due to aneurysm rupture. The aim of this review is to summarize the developments in the literature concerning the latest biomarkers (from 2008 to date) and their potential screening and therapeutic values. Our search included human studies in English and found numerous novel biomarkers under research, which were categorized in 6 groups. Most of these studies are either experimental or hampered by their low numbers of patients. We concluded that currently no specific laboratory markers allow screeing for the disease and monitoring its progression or the results of treatment. Further studies and studies in larger patient groups are required in order to validate biomarkers as cost-effective tools in the AAA disease.

SURGICAL MANAGEMENT OF EXTRACRANIAL INTERNAL CAROTID ANEURYSMS BY CERVICAL APPROACH

Background:  Extracranial internal carotid artery aneurysms (EICAA) are rare vascular problems with a great potential for lethal thromboembolic episodes.

The role of carotid plaque echogenicity in baroreflex sensitivity.

OBJECTIVE The baroreflex sensitivity is impaired in patients with carotid atherosclerosis. The purpose of our study was to assess the impact of carotid plaque echogenicity on the baroreflex function in patients with significant carotid atherosclerosis, who have not undergone carotid surgery. METHOD Spontaneous baroreflex sensitivity (sBRS) was estimated in 45 patients with at least a severe carotid stenosis (70%-99%). sBRS calculation was performed noninvasively, with the spontaneous sequence method, based on indirectly estimated central blood pressures from radial recordings. This method failed in three patients due to poor-quality recordings, and eventually 42 patients were evaluated. After carotid duplex examination, carotid plaque echogenicity was graded from 1 to 4 according to Gray-Weale classification and the patients were divided into two groups: the echolucent group (grades 1 and 2) and the echogenic group (grades 3 and 4). RESULTS Sixteen patients (38%) and 26 patients (62%) were included in the echolucent and echogenic group, respectively. Diabetes mellitus was observed more frequently among echolucent plaques (χ(2) = 8.0; P < .004), while those plaques were also more commonly symptomatic compared with echogenic atheromas (χ(2) = 8.5; P < .003). Systolic arterial pressure, diastolic arterial pressure, and heart rate were similar in the two groups. Nevertheless, the mean value of baroreflex sensitivity was found to be significantly lower in the echogenic group (2.96 ms/mm Hg) compared with the echolucent one (5.0 ms/mm Hg), (F [1, 42] = 10.1; P < .003). CONCLUSIONS These findings suggest that echogenic plaques are associated with reduced baroreflex function compared with echolucent ones. Further investigation is warranted to define whether such an sBRS impairment could be responsible for cardiovascular morbidity associated with echogenic plaques.

An overview of laparoscopic techniques in abdominal aortic aneurysm repair

BACKGROUND Since 1993, various laparoscopic techniques have been developed to make laparoscopic treatment of abdominal aortic aneurysms (AAAs) a possible therapeutic alternative. We aim to review all published clinical studies on laparoscopic surgery of AAAs and juxtarenal abdominal aortic aneurysms (JAAAs). METHODS A thorough search of English-language literature published between January 1966 and December 2012 was performed. Studies that reported the results of laparoscopic surgical procedures as the intended repair strategy in patients with AAAs and JAAAs were selected using specific inclusion criteria. Only case series containing more than five patients were included. Outcome measures of eligible studies were extracted, tabulated, and then analyzed cumulatively, using a purely descriptive approach. RESULTS Fourteen studies were included in the analysis encompassing 933 patients with AAAs (mean age, 68.5 years; age range, 46-88) averaging 55.8 mm in diameter and 96 patients with JAAAs (mean age, 71 years; age range, 50-81) averaging 57 mm in diameter. The mean follow-up was 15.3 months for the AAA cases and 32.8 months for the JAAA cases. Hand-assisted laparoscopy, in particular, had a low 30-day mortality rate, short cross-clamping and operative times, few perioperative and postoperative complications, high graft patency rates, and short length of both hospital and intensive care unit stay. CONCLUSIONS Laparoscopic surgical procedures are a safe, feasible, and worthwhile alternative for patients with AAAs and JAAAs. Hand-assisted laparoscopy, in particular, was associated with low morbidity and mortality and short hospital and intensive care unit stay. However, the final decision regarding the best laparoscopic treatment should be left to the surgeon because of the limits of the data.

Cellular proliferation in complicated versus uncomplicated atherosclerotic lesions: Total cell population, foam cells and newly formed microvessels

Although cellular proliferation is a key component in the progression of atherosclerosis, research so far has been focused primarily on VSMCs. In this study we attempted to evaluate overall proliferation rates in general, as well as foam cells and the endothelial cells lining newly formed plaque microvessels in particular. For this purpose, cellular proliferation was assessed through immunohistochemical staining for PCNA in 10 fresh human carotid artery samples received from patients undergoing carotid endarterectomy. Overall proliferative activity was found significantly higher (P<or=0.01) among complicated type VI lesions compared to uncomplicated type V lesions. A similar assessment focused on foam cells alone also revealed a significantly higher (P<or=0.05) proliferative index among complicated lesions. On the other hand, the proliferation rate for the endothelial cells lining the interior walls of newly formed microvessels was harder to properly assess, since only two of the uncomplicated lesions bore signs of neovascularization. Still, both of these samples displayed proliferation rates similar to those of the complicated type VI lesions. Thus, it seems that, although total cell population and foam cells are probably affected by the stimulating factors that are expressed during acute events, the same does not apply to the endothelial cells lining plaque vessels.

A hybrid approach using a composite endovascular and open graft procedure for a symptomatic common femoral aneurysm extending well above the inguinal ligament

We report the use of a unique hybrid technique to treat a patient with a painful aneurysm extending both above and below the inguinal ligament. The patient was at high surgical risk, and endovascular treatment was not possible due to the absence of an appropriate vascular access site. Under local anesthesia, this aneurysm was treated using both a stent graft and a traditional Dacron graft for the iliac and femoral portions, respectively. Simultaneously, a popliteal aneurysm was treated endovascularly through a jump graft, which was used to bypass a short occlusion at the origin of the superficial femoral artery. Hybrid techniques can be an alternative approach in high-risk patients where endovascular procedures cannot be applied.

Current Debates on the Treatment of Carotid Stenosis in Both Symptomatic and Asymptomatic Patients A Reappraisal

We read with interest the debate on the treatment of carotid artery disease by Paraskevas et al. This is indeed very controversial, and the optimal management of patients with asymptomatic carotid stenosis (ACS) or symptomatic carotid stenosis (SCS) needs to be elucidated in future randomized clinical trials (RCTs). We discuss the results of 3 relevant RCTs published following the article by Paraskevas et al. The first is the report of the long-term results of the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) trial. Once again, the rate of the primary long-term end point (postprocedural ipsilateral stroke over the 10-year follow-up) did not differ significantly between the 2 groups (hazard ratio 0.99; 95% confidence interval [CI]: 0.64-1.52). However, CREST included both symptomatic and asymptomatic patients, and, more importantly, it did not compare carotid artery stenting (CAS) versus carotid endarterectomy (CEA) versus best medical treatment (BMT) for asymptomatic patients. As discussed by Paraskevas et al, this comparison is urgently needed and it is the very reason why CREST-2 was launched. A new RCT evaluated the efficacy of CAS in patients with ACS having severe stenosis and low or moderate morbidity risk. CAS was not inferior to CEA in terms of stroke, death, or myocardial infarction (MI) within the first 30 days after intervention (3.3% vs 2.6%, P 1⁄4 .6). Similarly, at 5-year follow-up, the survival rate for the CAS group was 87.1% and 89.4% for the CEA group (P 1⁄4 .21), and the rate of freedom from nonprocedure-related ipsilateral stroke was 97.8% and 97.3%, respectively (P 1⁄4 .51). Once again, this major RCT verified that CAS is associated with outcomes similar to CEA in patients with ACS. This, however, was already well known. The real issue (which is the comparison of CAS vs CEA vs BMT) was once again not addressed. The outcomes of CEA under regional anesthesia (RA) is another issue that deserves to be explored. Another analysis of the CREST data comparing CAS versus CEA under general anesthesia (GA) versus CEA-RA in both patients with SCS and patients with ACS demonstrated a noninferiority of CAS compared to CEA-RA in terms of periprocedural MI rates (odds ratio [OR]: 1.07; 95% CI: 0.25-4.66; P 1⁄4 .93) and a superiority when compared to CEA-GA (OR: 2.01; 95% CI: 1.14-3.54; P1⁄4 .02). In terms of stroke or death, CAS was also not inferior compared to CEA-RA (OR: 0.20; 95% CI: 0.03-1.47; P 1⁄4 .11) and inferior to CEA-GA (OR: 0.46; 95% CI: 0.27-0.76; P 1⁄4 .003). In both groups, the percentage and number of patients with SCS and ACS were similar. The CEA-RA group included less patients with SCS compared to the other groups, so the correlation of CEA-RA and periprocedural stroke rates in patients with SCS should be cautiously evaluated and further elucidated. Paraskevas et al identify a number of issues that need to be addressed in future RCTs. The recent trials do not provide definitive answers. These issues must be specifically identified and addressed in well-planned, appropriately designed RCTs.

Apolipoprotein J as a predictive biomarker for restenosis after carotid endarterectomy: a retrospective study

Carotid endarterectomy (CEA) is an effective surgical option for stroke prophylaxis in most patients. Restenosis after CEA can lead to re-intervention and adverse events, but the factors predicting restenosis are poorly understood. Apolipoprotein J (ApoJ) is considered to be a novel predictive factor of vascular restenosis and is associated with a large number of processes related to atherosclerosis and cell-cycle phases. The aim of this study was to elucidate the predictive value of Apo J in internal carotid artery (ICA) restenosis following CEA. This retrospective study examined all prospectively collected data for patients who underwent CEA at our surgical department over a 2-year period. The serum ApoJ levels of 100 patients were examined; 56 patients who underwent CEA comprised the vascular group (VG), and 44 patients who underwent minor surgery comprised the control group (CG). ApoJ samples were obtained preoperatively, 24 h after the surgical procedure and at 1, 6 and 12 months thereafter during the follow-up. The preoperative difference in ApoJ levels between the CG and VG was statistically signifcant; the mean values were 39.11±14.16 and 83.03±35.35 μg/mL, respectively. In the VG, the serum ApoJ levels were 112.09±54.40, 71.20±23.70, 69.92±25.76 and 62.25±19.17 μg/mL at postoperative day 1 and at 1, 6 and 12 months post-operatively, respectively, while the ApoJ concentrations of patients in the CG remained unchanged. Further subdivision of the VG into patients with or without restenosis revealed that restenosis patients presented signifcantly higher mean ApoJ values than non-restenosis VG patients. In summary, ApoJ seems to be an important predictor for carotid restenosis at 6 and 12 months postoperatively.