Christos Karathanos

Endovascular Stent-Graft Repair of Major Abdominal Arteriovenous Fistula: A Systematic Review

Purpose: To evaluate the outcomes of endovascular stent-graft repair of major abdominal arteriovenous fistulas. Methods: The English literature was systematically searched using the MEDLINE electronic database up to January 2009. All reports on endovascular stent-graft repair of major abdominal arteriovenous fistula were considered. Our experience of abdominal arteriovenous fistula was involved in the data analysis. The primary outcome measures were technical success and perioperative, 30-day, and overall mortality. Results: Data for the final analysis were extracted from 21 papers reporting on 22 patients and from the medical records of a patient treated at our institution. The most common causal associations of these fistulae were the presence of an aortoiliac aneurysm and previous endovascular aneurysm repair, accounting for 56% and 13% of all associations, respectively. The technical success rate was 96% (22/23). No perioperative or 30-day mortality was noticed during a mean follow-up of 9 months. The most common procedure-related complication was type II endoleak, which was found in 22% (5/23) of the patients. This event was either self limiting or required minimal percutaneous intervention. Conclusion: Endovascular stent-graft repair of major abdominal arteriovenous fistula is a safe and effective treatment option, with good short- and midterm results. However, no long-term data exist, and larger series are required to draw solid conclusions regarding the outcomes of this method.

Hybrid Endovascular and Open Treatment of Severe Multilevel Lower Extremity Arterial Disease

OBJECTIVE To evaluate the feasibility and efficacy of simultaneous combined endovascular and open lower extremity arterial reconstruction. DESIGN Case series study with retrospective analysis of prospectively collected non-randomised data. METHODS Patients were divided into three groups: group 1 and group 2 included patients who underwent endovascular reconstruction proximal and distal to the site of open reconstruction, respectively, whereas group 3 included patients who underwent open surgery with both proximal and distal endoluminal procedures. Patency analyses were performed using Kaplan-Meier life tables. Univariate and multivariate analyses were used to assess the influence of various risk factors on primary patency. RESULTS Complete data were obtained from 60 patients who underwent 61 single-step hybrid procedures. Technical and haemodynamic success rates were 100% and 95%, respectively. The perioperative mortality rate was 3%. The primary and assisted-primary patency rates at 12 months were 71% and 98%, respectively. Primary patency rates were lower in group 3 when compared with groups 1 and 2 (log-rank test, p=0.006). The presence of diabetes and dyslipidaemia were independent predictors of decreased primary patency (p=0.003 and p=0.014, respectively). CONCLUSIONS Hybrid procedures provide an effective treatment management of selected patients with multilevel lower extremity arterial disease. The extent of the disease, diabetes and dyslipidaemia are associated with worse outcome.

A meta-analysis of combined endarterectomy and proximal balloon angioplasty for tandem disease of the arch vessels and carotid bifurcation

OBJECTIVE High grade stenoses of both the innominate (IA) or common carotid artery (CCA) and the carotid bifurcation are rare and represent a therapeutic dilemma for the treating physician. A hybrid procedure with concomitant carotid endarterectomy (CEA) and retrograde angioplasty has been proposed as a less invasive treatment option. The aim of this study is to review the existing literature on such hybrid procedures. METHODS An electronic search of the pertinent English literature was undertaken. A meta-analysis of all studies reporting on simultaneous carotid endarterectomy and retrograde angioplasty for the treatment of tandem internal carotid and proximal common carotid or innominate artery lesions was performed. RESULTS Thirteen studies, including 133 patients were identified. Sixty-eight percent of the patients were male, 83% symptomatic. Proximal lesions were located in ipsilateral CCA in 85 cases and in IA in 48 cases. Reported technical success of the procedure was 97%. In 79 of the 129 successful operations, a stent was implanted, while the remaining 50 patients underwent simple balloon angioplasty. Thirty-day mortality and stroke rate were 0.7% and 1.5%, respectively. Combined 30-day mortality and stroke rate was 1.5%. During a mean follow-up of 12 to 36 months, five patients presented symptoms of cerebral ischemia and 17 died. Ten patients developed restenosis of the proximal lesion, (4 symptomatic, 7 in cases without stent) and 2 restenoses of the endarterectomy (all asymptomatic). Restenosis was treated in 7 cases (4 repeat angioplasty, 3 bypass grafts). CONCLUSIONS This meta-analysis reports the largest collection of patients having undergone hybrid treatment of tandem disease of the arch vessels and carotid bifurcation. Results from this study show that the combined stroke and death rate with this approach is equal to or better than that for isolated endarterectomy. When possible, balloon angioplasty with stenting of the proximal component of this disease should be pursued to avoid restenosis.

Clinical relevance and treatment of carotid stent fractures

OBJECTIVE To review all published reports and investigate the clinical relevance and need for treatment of carotid stent fractures. METHODS Electronic and hand-searching of the published literature and the Manufacturer and User Facility Device Experience (MAUDE) database. RESULTS Thirteen articles were published. There are 10 case reports and 3 clinical studies. There are 26 reports of fractured stents in the MAUDE database. Fifty-five cases of carotid stent fractures are reported in total. A total of 201 carotid stents were examined in the 3 studies, and the incidence of fractures was 8.9% (18/201). Fractured stents were 22 Xact, 20 Acculink, 6 Precise, 2 Exponent, 1 Nexstent, 1 Genesis, 1 Symbiot, and 2 nonspecified nitinol self-expandable stents. Twenty-seven of the treated carotid lesions were atherosclerotic, 3 restenoses after carotid endarterectomy, 2 postradiational, 1 pseudoaneurysm, and 22 lesions of unknown pathology. Calcification was reported in 15 of the 27 atherosclerotic lesions (55.5%). Time from implantation to fracture ranged from 0 days (fracture during implantation) to 37 months. In 55% of the cases, stent fracture was associated with restenosis. Six patients presented with symptoms. Treatment was reported for 32 patients: 14 patients underwent de novo stent placement, 2 balloon angioplasty, 2 carotid endarterectomy, 2 bypass graft (1 vein, 1 polytetrafluoroethylene), 1 anticoagulation, and 11 patients were followed up. CONCLUSION Carotid stent fractures are mainly reported in self-expandable nitinol stents. Plaque calcification may be a risk factor for stent fractures. No difference was observed between open and closed-cell design. Stent fractures were often associated with restenosis and usually were asymptomatic. The actual incidence, clinical relevance, and optimal treatment remain to be clarified from larger prospective studies designed to investigate the issue.

Carotid Bifurcation Geometry and Atherosclerosis

Hemodynamic changes occurring at the initial segments of the arterial bifurcations appear to play an important role in the development of atherosclerotic plaque. Therefore, arterial geometry might be a potential marker for atherosclerosis. Considerable evidence suggests that geometry can influence local hemodynamics at the carotid bifurcation contributing to the development of atheroma. Bifurcation angle, differences in the area ratios including the flare, proximal curvature, sinus bulb width, and tortuosity of the internal or external carotid artery have been listed as potential contributory elements. These morphometric details have been studied not only in postmortem examination but also with the help of imaging modalities such as ultrasound, digital subtraction angiography, computed tomography angiography, and the assistance of computational models and magnetic resonance angiography. The establishment of certain anatomical and geometrical details in addition to traditional risk factors may help in the identification of patients at high risk of developing carotid artery disease. We reviewed the literature to highlight the evidence on the importance of various geometrical details in the development of carotid atheroma and to suggest areas of future research.

Renal function impairment in patients undergoing elective EVAR vs. elective open repair during follow up period: a systematic review of the literature.

BACKGROUND Endovascular (EVAR) or open surgical (OSR) repair are current treatment options for abdominal aortic aneurysm (AAA). OBJECTIVE To produce a systematic review comparing the impact of these 2 treatment options on renal function during mid- and long term follow up. METHODS The MEDLINE, EMBASE and Cochrane databases and key references were searched. RESULTS Six studies were included from 2000 to 2016, (4 retrospective and 2 RCT studies) reporting on 2,102 patients (54%; 1096 EVAR, 46%; 1006 OSR). The mean age in EVAR group ranged from 69.4 to 73.8 years (91% males), and in OSR group from 68 to 73.6 years (91% males). The data were too heterogeneous to perform a meta-analysis. All studies used GFR (Glomerular Filtration Rate) or estimated GFR (eGFR) to record renal function. The commonest risk factors were the presence of hypertension (77.5%), hyperlipidaemia (48.3%), coronary artery disease (42%) and smoking (37.8%). During follow up, new events of renal impairment (increase >20% in GFR) in EVAR patients and in OSR patients were 58 (5.3%) and 52 (5.2%), respectively. The mean GFR was decreased during follow up period in both types of the procedure. CONCLUSION There is lack of definitive evidence to prove the superiority of OSR over EVAR regarding renal function in the post-operative follow up period. It appears that renal impairment may occur after both interventions. Further prospective research is needed to clarify the issue.

Colonic Ischemia After Endovascular Exclusion of an Aortoiliac Aneurysm Using an Iliac Branch Device

Purpose: To present the first case of colonic ischemia (CI) after endovascular exclusion of an aortoiliac aneurysm using an iliac branch device (IBD). Case report: A 69-year-old male patient with an abdominal aortic and right common iliac artery aneurysm underwent endovascular repair with an IBD. Completion angiography demonstrated good patency in 2 of the 3 main branches of the right internal iliac artery (IIA) whereas the left IIA patency was preserved. Preoperatively, the inferior mesenteric artery (IMA) was patent. Postoperatively, the patient presented moderate CI. He was treated conservatively and discharged 15 days later with recession of the symptoms. Conclusion: Although preservation of bilateral iliac artery patency is considered to diminish the incidence of pelvic ischemia, in case of an exclusion of a patent IMA, collaterals may not be adequate to ensure blood supply to the left colon.

Tinzaparin in intermediate dose for the treatment of superficial vein thrombosis: Results from an observational multicenter study—SeVEN study:

Objectives Low-molecular-weight heparins are recommended in the treatment of superficial vein thrombosis but with low grade of evidence. This study was conducted to assess the treatment outcomes of acute superficial vein thrombosis with intermediate dose of Tinzaparin. Methods Retrospective analysis of records from outpatients over a period of 16 months treated in seven centers with Tinzaparin 0.5 ml (10,000 anti-Xa IU) once daily for a period that was at the treating physician’s discretion. All the patients were followed up for at least 12 weeks. Results A total of 296 patients (189 females, mean age 57.4 years) were included. Two thirds of the patients (191/296, 64.5%) received treatment for approximately five weeks (mean 36.9 days) and the remaining (105/296, 35.5%) for a shorter period (mean 16.2 days). There was no difference in patients’ characteristics between the two treatment duration groups. The presence of thrombus above the knee and restricted daily activity were associated with longer period of treatment. Only one case with minor bleeding was observed. Recurrence of thrombosis over a 12-week follow-up period occurred in 6% (superficial vein thrombosis in 14 (4.7%), deep vein thrombosis in 3 (1%) and thrombus extension in the superficial veins in 1 (0.3%)). Recurrence was not related to the duration of treatment. Conclusions Intermediate dose of Tinzaparin was an effective and safe treatment for superficial vein thrombosis in the setting of real world practice. Location of thrombus and status of patients’ mobilization were associated with longer duration of treatment. Future prospective randomized studies are needed to corroborate these findings.

Re: “Prognostic Factors in Diabetic Foot Ulcer”

We thank Biteker et al for the opportunity to clarify some issues regarding our observational study. The International Working Group on the Diabetic Foot guidance has recommended that diabetic foot infection (DFI) must be diagnosed clinically, based on the presence of local or systemic signs or symptoms of inflammation (strong recommendation; low level of evidence) and to assess the severity of any DFI using classification scheme (strong recommendation; moderate level of evidence). Within this context, we focused mainly in adhering to those recommendations in our observational study; thus, all patients underwent clinical evaluation for the presence of infection and were assessed according to 3 classification systems—the University of Texas wound classification, the DFI wound score based on Study of Infections in Diabetic feet comparing Efficacy, Safety and Tolerability of Ertapenem versus Piperacillin/Tazobactam trial, and wound, ischemia, and foot infection classification system of the Society for Vascular Surgery. Additionally, in our study, biomarkers such as C-reactive protein and erythrocyte sedimentation rate as well as the number of white blood cells, neutrophils, and platelets were included in multiple logistic regression analysis. Cultures from ulcer location were also assessed. It is of note that more than half of our patients had history of coronary artery disease (CAD) or/and peripheral arterial disease (PAD). This fact would be deterring for metalloproteinases (MMPs) analysis because it has been demonstrated that MMPs are significant circulating biomarkers that play a pivotal role in the initiation, progression, and clinical manifestations of CAD and PAD. Additionally, another factor that could influence the objectivity of an MMPs’ analysis was the chronic prescription of statins in 70% of the patients. Recently, it has been suggested that statins may have a potential downregulating overexpression role of MMPs. Future studies are needed to be specifically designed in order to assess the predictive value and cost-effectiveness of MMPs in diabetic foot ulcer healing, before using it in clinical practice. References

Role of Computed Tomographic Angiography in Central Venous Catheter Related Complications in Dialysis Patients

Background: The central venous catheter (CVC) is broadly used in medical practice. However, its use constitutes an invasive procedure with morbidity. Objectives: To assess the role of computed tomographic angiography (CTA) in CVC related complications and the mid-term outcome of dialysis patients after their treatment. Methods: This is a retrospective analysis of prospectively collected data of dialysis patients treated for CVC-related complications and their monitoring during a midterm follow-up. Results: From 2012 - 2014, eight patients (mean age 59±1.2 years; 6 males) with CVC related complication were treated. All complication were diagnosed and verified by a CTA (100%). Two patients presented with local hematoma, 3 with major bleeding, 2 with a retained guide-wire, and 1 with a disconnected part of a port-catheter. The direct repair of an arterial or venous wall injury was undertaken in 7 patients, with the simultaneous removal of a retained guide-wire in 2 and the removal of a misplaced CVC in 1 of them. One patient had the endovascular approach with the removal of the disconnected part. No death or major complication occurred during the procedures. During the follow-up (range =12 - 24 mon), no re-intervention, clinical episode of venous thromboembolism, or death was recorded. Conclusions: Invasive treatment of dialysis patients for CVC related complications is effective and durable during mid-term follow up with no re-intervention, clinical episode of VTE or death. CTA is a reliable mean for the diagnosis of CVC related complications.