Biosynthetic vascular graft: a valuable alternative to traditional replacement materials for treatment of prosthetic aortic graft infection?

BACKGROUND AND AIMS: To report the experience of a tertiary vascular surgery center using Omniflow II® biosynthetic vascular grafts for treatment of prosthetic aortic graft infection. MATERIALS AND METHODS: Retrospective analysis of all patients with prosthetic graft infections who underwent in situ aortic reconstruction using Omniflow II® grafts or other conduits between March 2015 and May 2017. Early and late mortality, perioperative complications, and reinfection rate were analyzed. RESULTS: Sixteen patients (14 males, median age 68.5, range 57-89) with prosthetic aortic graft infection were treated at our center. Eight patients received an Omniflow II® biosynthetic graft, two patients silver-triclosan coated grafts, three patients bovine pericardial tube grafts, and three patients composite bovine pericardial tube grafts with Omniflow II® graft extensions. Perioperative complications occurred in seven patients (43.8%). Early mortality rate was 18.7% (n = 3). In addition, four patients died during follow-up after a median of 11 months (range 0-34 months). We did not observe any reinfections. Bypass grafts were patent in all patients. No major limb amputations were performed during follow-up. CONCLUSION: Treatment of prosthetic aortic graft infection with Omniflow II® vascular grafts is feasible. Graft material seems to have an excellent resistance to infection and might be a valuable alternative to traditional replacement materials. Especially long-term durability has to be continuously monitored and documented.

Comparison of Long-term Outcomes of Heparin Bonded Polytetrafluoroethylene and Autologous Vein Below Knee Femoropopliteal Bypasses in Patients with Critical Limb Ischaemia.

OBJECTIVE/BACKGROUND: Endovascular first is the preferred therapy approach to critical limb ischaemia (CLI). However, in spite of new endovascular techniques, bypass surgery still plays an important role, especially in patients with complex anatomy in whom endovascular therapy is not considered feasible, or has failed. The goal of this study was to analyse the outcomes of prosthetic or autologous vein for femoropopliteal (P3) bypasses performed under the abovementioned conditions. METHODS: A retrospective analysis of patients who underwent a femoropopliteal (P3) bypass for CLI (March 2007-December 2015) was conducted. Endovascular therapy was not possible. Patency rates, limb salvage, major adverse limb event (MALE) free survival, and survival after 5 years were analysed. RESULTS: In total, 151 cases were included in the analysis (rest pain 35.8%, ulcer/gangrene 64.3%). The graft material was autologous vein in 76 cases (vein group) and heparin bonded expanded polytetrafluoroethylene (HePTFE) in 75 cases (HePTFE group). Indications, risk factors, previous revascularisation procedures, and runoff vessels were similar in both groups. Thirty day mortality was 6.6% in the vein group and 5.3% in the HePTFE group (p = .508), early graft occlusion (6.6% vs. 5.3%; p = .508) and 30 day major amputation rate (0% vs. 2.7%; p = .245) were similar between the two groups. Overall primary patency was 51.7% (55.5% [vein group] vs. 51.7% [HePTFE group]; p = .897) and overall secondary patency was 64.2% (74.6% [vein group] vs. 55.6% [HePTFE group]; p = .119), all without significance after 5 years. However, limb salvage (79.1%) was significantly different (90.0% [vein group] vs. 62.9% [HePTFE group]; p = .021). Survival was similar between the groups (47.3% vs. 42.9%; p = .582) as well as MALE free survival (69.4% vs. 55.0%; p = .348). CONCLUSION: Bypasses to the below knee popliteal artery show good results in patients with CLI unsuitable for endovascular therapy. Vein is still the first line graft material.

A comparison of tibial and peroneal venous and HePTFE bypasses in diabetics with critical limb ischemia.

OBJECTIVE: In this study we analyzed the outcome of tibial and peroneal venous and heparin-bonded expanded polytetrafluoroethylene (HePTFE) bypasses in diabetics with critical limb ischemia (CLI). We aimed to verify our hypothesis that HePTFE grafts will achieve acceptable 1-year patency and limb salvage results in patients who lack an adequate vein. METHODS: We conducted a retrospective analysis for all diabetics who underwent tibial bypass surgery in our department between October 2007 and October 2012. The study includes 97 grafts. All these patients were not suited for an endovascular therapy. We used autologous veins in 56 cases (Vein-Group) and HePTFE grafts in 41 cases (HePTFE-Group). Study endpoints were primary and secondary patency, limb salvage, and survival at 2 years postoperatively. RESULTS: Risk factors and indications were similar in both groups. The comparison between HePTFE- and Vein-Group showed significantly different patency rates. At 2 years, primary patency was 39.3% in HePTFE-Group vs. 78.5% in Vein-Group (P = .003) and secondary patency was 47.4% vs. 81.9% (P = .002). Limb salvage at 2 years was 79.3% vs. 87.4% (P = .073) and survival was 64.6% vs. 62.9% (P = .593) at the 2-year mark, with no significant differences. 30-days mortality, graft occlusion and major amputation rate showed no significant differences, either. CONCLUSIONS: This study shows that HePTFE bypasses are a viable option for diabetics undergoing tibial bypass surgery when no adequate vein is available.

Xenografts in septic vascular surgery.

BACKGROUND: In general, autologous veins are the optimal replacement material for an infected vascular graft in terms of handling, durability and resistance to reinfection. In the absence of suitable autologous material, several options are available, each of which has specific advantages and drawbacks with regard to these characteristics. METHODS: In recent years, xenogeneic materials (in particular pericardial patches from different species and biosynthetic grafts) have been increasingly used as replacement material in the setting of infections. Bovine and equine pericardial patches are applied in particular as self-made tube grafts in the aortic region and also in infections of iliacofemoral prosthetic grafts and shunt infections. RESULTS: The results of small clinical series on durability and resistance to reinfection are promising. CONCLUSION: It is feasible to use biosynthetic materials to replace infected intracavitary and extracavitary vascular grafts with remarkably low reinfection rates; however, the unique mechanical properties of the grafts as well as the initially increased thrombogenicity, need to be taken into consideration.

Inflammatory diseases of the aorta: Part 1: Non-infectious aortitis.

Aortitis is a term which encompasses inflammatory changes to the aortic wall from various pathogenic etiologies. Large vessel vasculitis, such as Takayasu arteritis and giant cell arteritis represent the most common entities; however, there is also an association with other rheumatological diseases. Chronic idiopathic periaortitis represents a distinct disease entity and infectious aortitis is a rare but life-threatening disease. Due to the diverse clinical pictures vascular surgeons often face a significant challenge in terms of making an accurate initial diagnosis. Treatment requires an interdisciplinary approach. This article describes the pathogenesis of the various forms of aortitis as well as the diagnostic methods and treatment approaches.

Inflammatory diseases of the aorta: Part 2: Infectious aortitis.

Infectious aortitis is a rare but life-threatening disease. Due to impending local and systemic complications, prompt diagnosis and initiation of effective causal treatment are essential for patient survival. Differentiating infectious aortitis from other aortic diseases, in particular non-infectious aortitis, is of great importance. This article discusses the various causes, diagnostic tools, and therapeutic strategies for infectious aortitis.

Interventional Removal of Intravascular Medical Devices: Methods and Technical Success.

PURPOSE: Evaluation of the technical success rate and complications when retrieving dislocated intravascular foreign bodies. MATERIAL AND METHODS: Between 1999 and 2015 38 patients (21 female; 17 male; Age: 17 - 92; Average 54.3 years) underwent an extraction of intravascular dislocated foreign bodies, which were not lost during a radiological intervention. The extracted material included 29 port catheters, 3 tips of tunneled dialysis catheters, 2 stents, 2 guide wires, 1 CVC tip and 1 AS occluder device. Various catheters for repositioning and extraction were used. The access was transarterial as well as transvenous. Technical success was defined as complete removal of the foreign body. RESULTS: The technical success rate was 92.1 % (35 of 38). In 17 patients an additional catheter was necessary to reposition the foreign body in order to make it accessible for the extraction catheter. In one case a stent was relocated and remodeled within the patient and was not extracted. In another case we experienced a dislocation of a small fragment of the port catheter into the distal parts of the pulmonary artery, which couldn't be extracted. A guide wire could not be extracted as it was already adhered with the vessel wall. Peri-interventional complications were not documented. CONCLUSION: The percutaneous extraction of dislocated intravascular foreign bodies is technically successful and poor of complications. Interventional therapy can avoid surgical removal. KEY POINTS: • The percutaneous extraction of dislocated intravascular foreign bodies is technically successful and safe.• In most cases surgical removal can be avoided.• The gooseneck-snare catheter was mainly used for the extraction of intravascular foreign bodies. Citation Format: • Ayx I, Goessmann H, Hubauer H et al. Interventional Removal of Intravascular Medical Devices: Methods and Technical Success. Fortschr Röntgenstr 2016; 188: 566 - 573.

The impact of infrainguinal endovascular interventions on the results of subsequent femoro-tibial bypass procedures: a retrospective cohort study.

BACKGROUND: Endovascular recanalization has become the accepted first-line treatment strategy for most lower extremity arterial occlusions, especially in patients with critical limb ischemia (Rutherford 4-6). Prior endovascular interventions have been described as risk factors for the outcome of subsequent lower extremity bypass surgery. The effect on subsequent tibial and peroneal bypasses is controversial. We analyzed the impact of prior endovascular lower extremity revascularization procedures on the short- and mid-term results of femoro-tibial and femoro-peroneal bypasses. METHODS: A retrospective analysis was conducted of all patients who had undergone tibial or peroneal bypass surgery after prior endovascular interventions (PEI-Group, n=40) of the same extremity in our department from October 2007 to October 2012. We compared this group with a group of patients who had received a tibial or peroneal bypass as primary revascularization procedure (BF-Group, n=93) during the same period of time because primary endovascular therapy had been deemed unfeasible in those cases. Indication in all cases was critical limb ischemia; the median age was 78 years (range 50-90 years), 45.1% were diabetics, and 42.9% were female. The graft material was autologous vein in 80 cases and HePTFE in 53 cases. Endpoints of the analysis were primary and secondary patency rates, limb salvage and survival at 2 years postoperatively. RESULTS: At 2 years overall primary patency was 68.4%, secondary patency was 69.5%, limb salvage was 83.6% and survival was 62.6%. Primary patency for the BF-Group was 74.3% vs. 55.1% for the PEI-Group (P=.310) at 2 years; secondary patency was 74.6% vs. 59.1% (P=.268). Prior endovascular intervention did not have any significant effects on limb salvage (83.7% vs. 83.6%; P=.470) or survival rates (61.0% vs. 65.0%; P=.258) at the 2-year mark, either. There were no significant differences in graft occlusion, death and major amputation rates within the first 30 postoperative days. Except for male gender, there were no significant differences in risk factors and indications between the two groups. CONCLUSIONS: Prior endovascular intervention of femoro-tibial vessels does not have a negative impact on the outcome of subsequent tibial or peroneal bypass surgery in patients with critical limb ischemia.

[Hybrid operation theatre in vascular surgery. Options and perspectives]. / Hybridoperationssaal in der Gefäßchirurgie. Möglichkeiten und Perspektiven.

BACKGROUND: Demographic development leads to an increase in vascular interventions due to the increase in elderly and multimorbid patients. The aim of this study was to demonstrate the open interventional therapy options and their influence on staff and patients which have become possible due to the introduction of angio-hybrid operations including 3-D imaging Dyna-CT. MATERIAL AND METHODS: The modifications with respect to radiation protection for staff, improvements for patients and the possibilities of operative 3-D imaging Dyna-CT are described based on the current literature. RESULTS: The implementation of angio-hybrid operation theaters has resulted in new open interventional treatment options which can also be employed for high risk elderly patients with aortic and peripheral arterial pathologies. With hybrid operations the radiation exposure and contrast medium exposure can be reduced for patients and an improvement in the results can also be achieved. The implementation of 3-D imaging in the angio-hybrid operation theater could also lead to further improvements, especially for complex aortic procedures. DISCUSSION: Using angio-hybrid operational procedures complex interventions can be carried out with more safety for patients and personnel. The implementation of 3-D imaging Dyna-CT offers additional interesting options for complex aortic procedures.

[Hybrid operating rooms: only for advanced endovascular procedures?]. / Angio-Hybrid-Operationsraum: Grundvoraussetzung nur für komplexe endovaskuläre Eingriffe?

The evolution of endovascular techniques has led to the concept of the "hybrid operating room" (hybrid OR). A hybrid OR combines the sterility of an OR in an operating theatre environment with a high-quality fixed imaging system. On the basis of these advantages it would be desirable that an angio-hybrid OR becomes a standard requirement for endovascular surgery. In Great Britain guidelines have already been published that require a hybrid OR even for normal endovascular management of the infrarenal aorta. However, in Germany there are no guidelines from professional societies or formal rules from the federal joint committee, thus in this article a classification of endovascular procedures according to their complexity and the necessary infrastructures are proposed in order to define particular procedures that should only be performed in an angio-hybrid OR. According to our experience, endovascular procedures can be classified into four categories based on their complexity and the requirements regarding fluoroscopy: level 1: standard EVAR, TEVAR, iliac and popliteal artery procedures; level 2: iliac branched (IBD) and standard (2 fenestrations for the renal arteries and a scallop for the superior mesenteric artery) fenestrated stent-grafting; level 3: more complex fenestrated procedures (three or four fenestrations); and level 4: branched stent-grafting for TAAA. At this moment it is still acceptable to perform level 1 and level 2 procedures outside of a hybrid OR. In our opinion, it is not recommended to perform level 3 and level 4 endovascular procedures without a hybrid OR.

VEGF: a surrogate marker for peripheral vascular disease.

This study aims to evaluate the value of VEGF as a surrogate marker for peripheral vascular disease (PVD). Prior to treatment, serum VEGF levels were evaluated by enzyme-linked immunosorbent assay (ELISA) in 293 PVD patients. Risk factors and clinical parameters of PVD were documented. Twenty-six age-matched healthy volunteers served as controls. Serum VEGF values strongly correlated with Fontaine stages (p<0.006, stage IV vs. controls). High VEGF values prior to treatment were associated with poor outcome. Serum VEGF appears to indicate the severity of PVD and might serve as a surrogate indicator of disease severity.

Retrojugular versus ventrojugular approach to carotid bifurcation for eversion endarterectomy: a prospective randomized trial.

OBJECTIVES: The aim of this prospective randomized study was to demonstrate the comparability of retrojugular access for carotid eversion endarterectomy compared to the conventional ventrojugular procedure. PATIENTS AND METHODS: Due to the expected minor and major complication rate of 5% in patients undergoing carotid surgery, a patient cohort of 600 study patients was planned. All patients underwent standard preoperative and postoperative assessment including clinical investigation and fiberoptic laryngoscopy. The 6 month follow-up examination included an evaluation of patient contentment, a duplex scan, clinical investigation and a fiberoptic laryngoscopy. RESULTS: After the first interim evaluation of 101 patients, the study was stopped because of a significant increase in temporary ipsilateral vocal cord motility dysfunction in the retrojugular access group (31% vs. 6%, p=0.0014). This early postoperative impairment was, however, not statistically significant at the follow-up examination at 6 months (2.4% vs. 0%). No other significant differences concerning major complications (death or stroke), other cranial nerve injuries, wound healing, or patient satisfaction was observed neither in the early postoperative phase nor at follow up. CONCLUSION: Due to the high incidence of temporary ipsilateral vocal cord dysfunction in patients undergoing retrojugular exposure of the carotid artery, we recommend the conventional ventrojugular approach, which can be performed by incision along the anterior border of the sternomastoid muscle or by transversal skin incision.

Early experience shows rapid shrinking of abdominal aortic aneurysms after endovascular treatment with Anaconda device.

BACKGROUND: The Anaconda prosthesis is a new endovascular device for abdominal aortic aneurysms repair. AIM: of the study was to evaluate successful access to the arterial site, safety and efficacy of stent placement and fixation, assessment of endoleaks, patency of the graft due to twists, kinks or obstruction within the first 30 days after the procedure. Secondary objectives were the assessment of clinical success after 6 months due to graft patency and aneurysm exclusion without endoleak as well as the continuing clinical success without showing aneurysm expansion or any graft failure. PATIENTS AND METHODS: Between 2003 and 2006 a total of 14 patients with infrarenal aortic aneurysm (median diameter prior to endovascular treatment: 56.7 mm (range: 50 to 70 mm) were treated with the Anaconda endovascular device. 8 of these patients were treated in accordance to a prospective Phase II clinical study protocol (Anaconda ANA 004). 6 more patients received the same endovascular device after CE-certification. RESULTS: Primary and secondary objectives were achieved in 12 of 14 patients after 6 months. In one patient insertion of the graft system was impossible due to kinking and circular calcification of the iliac arteries. Iliac access utilizing an alternative stent graft system (Cook, Zenith) was also unsuccessful. This patient underwent a conversion to open surgery and died. Another patient died 6 months after treatment unrelated to the procedure. A significant reduction of the median aneurysm diameter from 56.7 to 49.0 mm (range: 45 to 54 mm) was achieved after 6 months (p = 0.05). No endoleak was seen in the follow up. CONCLUSIONS: Early results show that he Anaconda endovascular device for aneurysm repair is a safe and effective device for patients with suitable abdominal aortic aneurysms and proper distal access vessels which results in significant aneurysm diameter decrease and a low complication rate after 6 months of follow-up.

[Diagnosis and endovascular treatment of proximal endograft instability after thoracic endografting]. / Diagnostik und endovaskuläre Behandlung einer proximalen Endograft-Instabilität nach thorakalem Endostent.

Four cases of proximal endostent instability after endovascular tube graft treatment of thoracic aortic disease using the TAG Gore system are reported. This potentially hazardous complication is characterized by a lack of attachment of the device to the small curvature of the aortic arch. Towering up against the hemodynamic forces in this area, the endograft could collapse and occlude the aorta. To identify this complication we recommend to perform an early postinterventional CT-scan with parasagittal reconstruction and an observation of the proximal endograft by fluorography. Endovascular solutions for the treatment of this complication may be either a proximal extension by another endograft or fixation of the proximal endograft by a balloon expandable Palmaz stent.

General versus locoregional anesthesia in carotid surgery: a prospective randomised trial.

BACKGROUND: To evaluate the influence of anesthetic technique on perioperative neurological and cardiopulmonary complication rates in patients undergoing carotid endarterectomy. PATIENTS AND METHODS: 186 patients with symptomatic internal carotid artery (ICA) stenosis > 70% or asymptomatic ICA stenosis > 80% were prospectively randomized for either locoregional (LA) or general anesthesia (GA). RESULTS: Neurological complication rates were similar in both groups (GA 2% vs. LA 2%). Cardiopulmonary complication rates were not significantly different (GA 4% vs LA 1%). There were no stroke-related deaths, but one patient from the GA group died from severe postoperative pneumonia. Thus, a significant difference in combined stroke/cardiopulmonary related death between the two groups (GA 1% vs LA 0%) could not be found. However, perioperative cardiopulmonary monitoring showed that significantly more patients operated under general anesthesia had hypertensive events, with systolic blood pressure values greater than 180 mmHg on postoperative day one. There were no differences in the number of postoperatively hypotensive episodes (systolic blood pressure values < 100 mmHg) between the two groups. CONCLUSIONS: Significant differences in the perioperative neurological and cardiopulmonary complication rates between general and locoregional anesthesia in patients undergoing carotid endarterectomy could not be observed.

[Popliteal vein entrapment in patients with unspecific symptoms of venous insufficiency]. / Belastungs- oder lageabhängige Schwellung der Wadenmuskulatur mit Spannungsgefühl und krampfartigen Schmerzen.

Popliteal vein entrapment must be taken in consideration in patients with symptoms of venous insufficiency. Leg edema, swelling, calf pain, and muscle cramps are all unspecific signs. Most patients thus far have presented with deep vein thrombosis or chronic venous insufficiency. Popliteal entrapment syndrome must be taken into account in younger patients in whom predisposing factors are absent and chronic calf swelling is notable. Diagnosis is easily confirmed by noninvasive stress testing with duplex imaging and pencil Doppler probe placed over the posterior tibial artery. Additionally, digital subtraction angiography with the foot in neutral and dorsi plantarflexion is recommended for arterial entrapment. Surgery is advisable for treatment and can be done without significant morbidity. In asymptomatic patients, we suggest using the term "popliteal vein entrapment phenomenon." We describe different etiologies of popliteal vein entrapment in three cases and present a review of the literature.

[Carotid endarterectomy and carotid stenting. A pilot study of a prospective, randomized and controlled comparison]. / Karotisendarteriektomie und Karotisstenting. Pilotstudie eines prospektiven, randomisierten und kontrollierten Vergleichs.

INTRODUCTION: A prospective, randomized and controlled trial is conducted to compare carotid endarterectomy and carotid stenting in high grade symptomatic carotid artery stenoses. METHODS: According to the study design symptomatic patients with a angiographically high-grade (> or = 70%) internal carotid artery stenosis are included. Pre- and postinterventional diagnostics during the hospitalization period includes neurological assessment, duplex sonography of the cervical and cerebral arteries and magnetic resonance imaging of the brain. Follow-up examinations are scheduled after 1, 6 and 12 months and consist of a neurological assessment and duplex sonography. After 12 months selective angiography and magnetic resonance imaging of the brain will be performed additionally. During a period of 9 months up to now 23/137 patients treated for a carotid artery stenosis were included in the study, 11 patients underwent surgery and 12 patients carotid stenting. RESULTS: Carotid stenting and endarterectomy was primarily successful without residual stenosis > 30% in each patient without the occurrence of stroke or death. In 18 follow-up examinations (neurological assessment including duplex sonography) of 13 patients (13 follow-up examinations after 30 days, 5 after 6 months) no relevant restenosis and no stroke occurred. CONCLUSION: As of yet, carotid stenting was a safe procedure. Due to the small number of patients a definitive conclusion can not be drawn.

Tyramide signal amplification in brain immunocytochemistry: adaptation to electron microscopy.

The tyramide signal amplification (TSA) technique is well-established in light microscopic immunohistochemistry and in situ hybridization to improve the signal-to-noise ratio. The present study deals with its adaptation to the electron microscopic level using the pre-embedding technique and a modified protocol. The outcome of immunolabeling of most of the antigens tested in brain tissue, including endothelial and neuronal nitric oxide synthase, glial fibrillary acidic protein, and isolectin B4, was greatly improved. If signal amplification is required, the TSA-technique proved to be reliable with high specificity and good ultrastructural resolution.

Distribution of the endothelial constitutive nitric oxide synthase in the developing rat brain: an immunohistochemical study.

The present study deals with the distribution of endothelial constitutive nitric oxide synthase (ecNOS) in the developing rat brain using optimized protocols for preparation and fixation and the tyramide-signal-amplification technique. The immunostaining patterns of a monoclonal antibody against ecNOS are compared with results obtained with a rat pan-endothelial marker, the monoclonal RECA-1 antibody. It is shown that ecNOS is present in the endothelial lining of all types of blood vessels and the choroid plexuses of the rat brain from the beginning of vasculogenesis at embryonic day 11 until adulthood (75 weeks). The same is true for RECA-1 immunoreactivity, that was demonstrated in the developmental brain vasculature for the first time. Both antigens expressed identical immunostaining patterns. At all investigated stages of brain development neither ecNOS negative blood vessels nor ecNOS positive non-endothelial cells, e.g., neurons, were found. The data indicate that ecNOS is involved in the embryonic angiogenesis and the regulation of hemodynamic functions of brain vasculature throughout the individual life.

Immunocytochemistry of endothelial nitric oxide synthase in the rat brain: a light and electron microscopical study using the tyramide signal amplification technique.

There are many inconsistencies in the literature about the cellular and subcellular distribution of the endothelial isoform of nitric oxide synthase (eNOS) in the brain. We have re-investigated its localization by light and electron microscopical (LM, EM) immunocytochemistry and the NADPH-diaphorase reaction. Using bovine aortic tissue as a positive control the protocols for the fixation and staining procedure were optimized. Only cryosections immersion-fixed with aceton and a mixture of aldehydes exhibited a clear-cut immunostaining. In rat brain tissue the endothelium of the entire vasculature showed immunoreactivity and, in addition to that, the epithelial cells of the choroid plexuses, whereas neurons never displayed any signs of immunostaining. EM immunoprecipitates were seen irregularly distributed in the cytosol or attached to endocellular membranes. EM NADPH-diaphorase histochemistry using the tetrazolium salt BSPT provided incoherent pictures in so far as the reaction product was exclusively bound to membranes. The restriction of eNOS within brain tissue to the vasculature may have implications for the differential significance of NOS isoforms in brain function.