John D. Kakisis

Effects of Cyclic Strain on Vascular Cells

Hemodynamic forces, including shear stress and cyclic strain, have been recognized as important modulators of vascular cell morphology and function. The mechanism by which vascular cells sense and transduce the extracellular mechanical signals into the cell nucleus has only recently begun to come to light. Integrins, ion channels, platelet-derived growth factor receptors, and G proteins have been recognized as mechanosensors, converting the mechanical stimuli into chemical signals. Activation of second messengers, including mitogen-activated protein kinases, protein kinase C, and Akt, follows, leading to an increase in the activity of transcription factors such as activator protein (AP)-1, AP-2, cAMP-responsive element (CRE), early growth response (Egr)-1, and nuclear factor (NF)-kappa B. Binding of these factors to the DNA leads to activation of numerous genes that regulate cell proliferation, apoptosis, differentiation, morphology, migration, and secretory function. Understanding of these responses has provided new insights in the pathogenesis and treatment of vascular diseases, such as atherosclerosis and intimal hyperplasia.

Hybrid Open Endovascular Technique for Aortic Thoracoabdominal Pathologies

Background— Many authors using a hybrid debranching strategy for the treatment of thoracoabdominal pathologies have reported disappointing results and the initial enthusiasm for the technique has given way to criticism and ambiguity. The aim of the present meta-analysis study was to assess the safety and efficacy of the technique in patients with thoracoabdominal aortic aneurysms or other aortic pathologies. Methods and Results— A multiple electronic search was performed on all articles describing hybrid open endovascular repair. Separate meta-analyses were conducted for technical success, visceral graft patency, spinal cord ischemia symptoms, renal insufficiency, and other complications as well as 30-day/in-hospital mortality. Nineteen publications with a total of 507 patients were analyzed. The pooled estimates for primary technical success and visceral graft patency were 96.2% (95% CI, 93.5%–98.2%) and 96.5% (95% CI, 95.2%–97.8%) respectively. A pooled rate of 7.5% (95% CI, 5.0%–11.0%) for overall spinal cord ischemia symptoms was observed; whereas for irreversible paraplegia the pooled rate was 4.5% (95% CI, 2.5%–7.0%). The pooled estimate for renal failure was 8.8% (95% CI, 3.9%–15.5%). The pooled 30-day/in-hospital mortality rate was 12.8% (95% CI, 8.6%–17.0%). During the mean follow-up period of 34.5 (95% CI, 31.5–37.5) months, a total of 119 endoleaks were identified in 111 patients (22.7%). Conclusions— The repair of thoracoabdominal pathologies by means of hybrid procedures in patients who are poor surgical candidates is still associated with significant morbidity and mortality rates. Future studies may substantiate whether the technique is amenable to amelioration and improvement.

Management of complicated and uncomplicated acute type B dissection. A systematic review and meta-analysis

BACKGROUND The management of acute type B dissection represents a clinical challenge. We undertook a systematic review of the available literature regarding medical, surgical and endovascular treatments of acute type B aortic dissection and combined the eligible studies into a meta-analysis. METHODS An extensive electronic health database search was performed on all articles published from January 2006 up to November 2013 describing the management of acute type B aortic dissection. Studies including less than 15 patients were excluded. RESULTS ACUTE COMPLICATED TYPE B DISSECTION: overall, 2,531 patients were treated with endovascular repair (TEVAR) and the pooled rate for 30-day/in-hospital mortality was 7.3%. The pooled estimates for cerebrovascular events, spinal cord ischemia (SCI) and total neurologic events were 3.9%, 3.1% and 7.3%, respectively. A total of 1,276 patients underwent open surgical repair and the pooled rate for 30-day/in-hospital mortality was 19.0%. The pooled rate for cerebrovascular events was 6.8%, for SCI 3.3% and for total neurologic complications 9.8%. Acute uncomplicated type B dissection: outcome of 2,347 patients who underwent conservative medical management were analyzed. The pooled 30-day/in-hospital mortality rate was 2.4%. The pooled rate for cerebrovascular events was 1%, for SCI 0.8% and for overall neurologic complications 2%. CONCLUSIONS Endovascular repair provides a superior 30-day/in-hospital survival for acute complicated type B aortic dissection compared to surgical aortic reconstruction. However, open repair still has a significant role as endovascular repair is not applicable in all patients and there remains concerns regarding the durability of this technique. TEVAR seems to have a more favorable outcome regarding aortic remodeling and the aortic-specific survival rate when compared with medical therapy alone. Randomized controlled trials focusing on the prognostic factors of early and late complications in uncomplicated type B dissections are needed.

Results of carotid artery stenting with transcervical access

OBJECTIVE Carotid artery stenting (CAS) is usually performed with femoral access; however, this access may be impeded by anatomic limitations. Moreover, many embolic events happen during aortic arch catheterization. To overcome these problems, transcervical access to the carotid artery can be used as an alternative approach for CAS. METHODS An electronic search of the literature using PubMed was performed. All studies reporting the results of CAS using the transcervical approach were retrieved and analyzed. RESULTS The analysis included 12 studies reporting the results of 739 CAS procedures performed in 722 patients (mean age, 75.5 years). Of 533 lesions reported, 235 (44%) were symptomatic, with no data regarding symptomatic status available for 206 lesions. Two techniques were used: direct CAS with transcervical access (filter protected or unprotected) in 250 patients and CAS with transcervical access under reversed flow (with arteriovenous shunt in most cases) in 489 patients. Local anesthesia was used in 464 of 739 procedures (63%), and the remaining were performed under general anesthesia or cervical block. Technical success was 96.3% for 579 procedures with available data (558 successful procedures and 21 failures: inability to cross the lesion, 10; dissection, 5; failure of predilatation, 1; stent thrombosis, 1; patient agitation, 1; and no data, 3). The incidence of conversion to open repair was 3.0% (20 of 579 procedures: 18 carotid endarterectomies and two common carotid-internal carotid bypass grafts). Stroke occurred in eight patients (two fatal) and a fatal myocardial infarction in one patient. The incidence of stroke, myocardial infarction, and death was 1.1%, 0.14%, and 0.41%, respectively. The incidence of stroke was 1.2% (3 of 250) in direct CAS with transcervical access and 1.02% (5 of 489) in CAS under reversed flow (P > .05). Transient ischemic attack occurred in 20 patients (2.7%). Local complications were encountered in 17 of 579 CAS (2.9%), comprising 15 hematomas and two patients with transient laryngeal palsy. CONCLUSIONS CAS with the transcervical approach is a safe procedure with low incidence of stroke and complications. It can be used as an alternative to femoral access in patients with unfavorable aortoiliac or aortic arch anatomy.

De novo Renal Cell Carcinoma in a Kidney Allograft 13 Years after Transplantation: A Case Report and Review of the Literature

De novo carcinoma of the renal transplant is a rare but disastrous clinical entity. We report such a tumor developing 13 years after transplantation and describe its clinical presentation, diagnostic approach and therapy. The importance of a surveillance program allowing early detection of tumor developing in the renal transplant is emphasized.

Predictors affecting in-hospital mortality of ruptured abdominal aortic aneurysms: a Greek multicenter study.

BACKGROUND Endovascular aortic repair (EVAR) is being used with increasing frequency for the treatment of ruptured abdominal aortic aneurysms (rAAAs), although conflicting results have been reported concerning perioperative mortality. The aim of our study was to evaluate potential difference in mortality rates between EVAR and open surgical repair (OSR) and identify independent risk factors for in-hospital mortality in rAAAs. This study also aimed to evaluate the Glasgow Aneurysm Score (GAS) in predicting in-hospital mortality. A time-trend analysis of EVAR for ruptured AAAs was also performed. METHODS Prospectively collected data from 7 public hospitals in Greece concerning rAAA repairs between January 2006 and April 2012 were analyzed. Primary outcome was in-hospital mortality. Multivariate logistic regression analysis was used to identify independent risk factors. The receiver-operator characteristic curve was used to determine the value of the GAS in predicting in-hospital death. Time-trend analysis, depicting annual changes (%), concerning EVAR for ruptured AAAs was also conducted. RESULTS A total of 418 patients (92.3% men, mean age = 74.3 ± 8.8) with rAAAs were recorded during the study period. Among them, 113 patients (27%) underwent EVAR. Overall in-hospital mortality was 45.2%, whereas in-hospital mortality after EVAR and OSR was 20.4% and 54.3%, respectively (P < 0.001). Multivariate analysis evidenced that hemodynamic instability (P < 0.001), OSR (P < 0.001), age ≥80 years (P < 0.001), coronary artery disease (P < 0.001), and renal insufficiency (P = 0.02) independently increased in-hospital mortality. Area under the curve of GAS was 0.80 (95% confidence interval [CI] = 0.75-0.85, P < 0.001) for OSR and 0.64 (95% CI = 0.51-0.77, P = 0.04) for EVAR. Annual increase of proportion (%) of EVAR for rupture was 5% (P = 0.004). CONCLUSIONS EVAR is being used with increasing frequency for the treatment of rAAAs and it appears to be associated with lower in-hospital mortality compared with OSR, after adjustment for hemodynamic instability and known atherosclerotic risk factors. Preoperative predictors of in-hospital mortality such as GAS should be probably modified in these patients.

Endograft Accommodation on the Aortic Bifurcation: An Overview of Anatomical Fixation and Implications for Long-term Stent-Graft Stability

In light of the results of randomized trials, it seems that despite the favorable short and midterm outcomes of standard endografts, concern over endograft migration has escalated, as this event will be responsible for almost all late complications in endovascular aneurysm repair (EVAR). Migration forces, both caudal and sideways, depend heavily on blood pressure, inlet diameter, and angulation of the stent-graft, while the bifurcation generates more force than any other segment of the stent-graft. It thus seems that the position of the endografts flow divider influences force distribution and migration risk. Additionally, due to concomitant ongoing aortic degeneration, postoperative dilatation of the infrarenal aortic neck poses a threat to EVAR patients as soon as the diameter of the infrarenal neck reaches the dimensions of the proximal graft. This review evaluates the significance of endograft accommodation on the aortic bifurcation and cumulative experience of the only endografts utilizing this feature: the Zenith Composite and the Powerlink.

Endovascular Repair of Popliteal Artery Pseudoaneurysm With Arteriovenous Fistula After Knee Arthroscopy: Case Report and Literature Review

We report a case of postarthroscopic popliteal artery pseudoaneurysm (PSA) with arteriovenous fistula (AVF; PSA-AVF) in a 53-year-old woman who presented with limb edema, pain, and bruit 1 year after arthroscopic meniscectomy. She was treated percutaneously by covered stent deployment. After 6 months of follow-up, the patient was asymptomatic, with patency of the stent and occlusion of the AVF. A review of the literature was also performed to investigate the prevalence of postarthroscopic PSAs and highlight the endovascular approach of treatment. Endovascular approach with covered stent appears to be less invasive and might be an effective and feasible way of treatment of postarthroscopic popliteal PSA-AVF.

Rupture after endovascular abdominal aortic aneurysm repair: a multicenter study.

A total of 22 patients with ruptured abdominal aortic aneurysms (rAAAs) after previous endovascular aortic repair (EVAR; rAAAevar) were presented to 7 referral hospitals in Greece, between January 2006 and April 2012. Type Ia endoleak and endograft migration were identified in 72.7% and 50%, respectively. Compliance to follow-up protocol prior to rupture was 31.8%. In-hospital mortality was 36.4% (9.1% for those treated with secondary EVAR and 63.6% for those treated with open surgical repair, P = .02). An increase in the proportion of patients with rAAAevar among the total number of patients with rAAAs from 1.3% in 2007 to 18.2% in 2012 (P for trend = .04) was recorded, corresponding to an annual increase of 2.8% (b = 2.84, P = .04). Rupture after EVAR seemed to be a clinical entity encountered with increasing frequency over the past years. Type I endoleak and endograft migration were most frequently observed, whereas compliance to follow-up was low.

Retrograde Transpopliteal Approach of Iliofemoral Lesions

Purpose: Aim of this study is to present our initial experience with the use of the retrograde popliteal artery access in patients with certain anatomic lesions. Methods: Between September 2008 and September 2010, 24 patients underwent a transpopliteal retrograde subintimal recanalization. Instead of its usage when antegrade recanalization failed, the “facedown” technique was preferred as a first choice in patients with common femoral artery stenosis or occlusion, proximal lesions of the superficial femoral artery (SFA) with no stump, severe obesity, tandem iliac, and SFA lesions. Results: Technical success was achieved in 91.7% of patients.The complication rate was 12.5%. The primary patency at 6, 12, and 18 months was 86.4%, 65.8%, and 65.8%, respectively. Conclusions: The retrograde popliteal artery approach can be considered as the primary SFA recanalization strategy in carefully selected patients, with competitive immediate and midterm results.