Editor's choice--Temporary aneurysm sac perfusion as an adjunct for prevention of spinal cord ischemia after branched endovascular repair of thoracoabdominal aneurysms.

OBJECTIVE: To report experience with the concept of temporary aneurysm sac perfusion (TASP) and second stage side branch completion to prevent severe spinal cord ischemia (SCI) after branched endovascular aortic repair (bEVAR) for thoracoabdominal aortic aneurysm (TAAA). METHODS: Patients were treated for TAAA with bEVAR between January 2009 and September 2012. TASP was performed by non-completion of side branches to one of the reno-visceral arteries, distal aortic or iliac extensions with secondary side branch completion. Primary endpoints of the study were overall technical success, side branch patency, perioperative mortality, and the rate of severe SCI. RESULTS: Eighty-three patients were treated for TAAA with branched aortic stent grafts with (n = 40) or without (n = 43) TASP. Overall technical success, including aneurysm exclusion, absence of persistent type I or III endoleak, TASP side branch patency, and secondary side branch completion was 35/40 (88%). Secondary TASP side branch completion was performed after a median of 48 days (range 1-370 days). The rate of early re-interventions for reno-visceral side branch complications was 8/283 (3%) and 6/83 (7%) for perioperative mortality, with three patients in both groups. Severe SCI or paraplegia was observed in 11/83 (13%) of the patients and reduced in the TASP group (2/40) compared with the non-TASP group (9/43; p = .03), especially in Crawford I-III aneurysms (1/29 vs. 7/24; p = .01). However, one TASP patient died 4 months after bEVAR during the TASP interval from suspected aorto-bronchial fistula. CONCLUSION: The concept of TASP after bEVAR for TAAA is feasible and seems to reduce the risk of SCI. Early side TASP branch completion within 4 weeks is recommended to reduce the risk of rupture, although, according to the individual clinical presentation, a longer TASP interval might improve neurological rehabilitation from SCI.

[The significance of contrast-enhanced ultrasound in vascular surgery]. / Stellenwert der Kontrastmittelsonografie in der Gefäßchirurgie.

BACKGROUND: Vascular contrast-enhanced ultrasound (CEUS) is a special ultrasound application without the harmful side effects of nephrotoxicity and radiation exposure. CEUS can be used for advanced diagnosis of carotid stenosis and follow-up checks of endovascular repair of abdominal aortic aneurysms (EVAR). Low-flow phenomenon in peripheral vascular disease can easily be detected by enhanced colour-coded duplex sonography (CCDS). METHODS: The technical requirements of CEUS are explained here for the aorta, carotid, and peripheral arteries. The benefits and risks compared to computed tomography (CT), magnetic resonance (MR) and angiography are evaluated. Based on a selective review of the literature and the authors' personal experiences, CEUS is recommended for routine surveillance after EVAR. RESULTS: CEUS is a safe method using SonoVue® (Bracco) as the only approved agent for vascular examination. Special equipment and training is necessary. In prospective studies and meta-analyses the detection and characterisation of endoleaks is comparable to that of CT imaging. Neovascularisation as a sign of carotid plaques at risk can be seen without the need for invasive treatment. Imaging of crural vessels with enhanced CCDS is a promising but rarely needed option in diabetic and renally insufficient patients. CONCLUSION: CEUS in vascular medicine should be performed prior to other methods to avoid nephrotoxic contrast agents for the patients, especially in follow-up checks after EVAR. The time and effort required are still limiting its practical breakthrough.

Cerebral arteriogenesis is enhanced by pharmacological as well as fluid-shear-stress activation of the Trpv4 calcium channel.

OBJECTIVES: This study aimed to determine the importance of the shear-stress-sensitive calcium channels Trpc1, Trpm7, Trpp2, Trpv2 (transient receptor potential cation channel, subfamily V, member 2) and Trpv4 for cerebral arteriogenesis. The expression profiles were analysed, comparing the stimulation of collateral growth by target-specific drugs to that achieved by maximum increased fluid shear stress (FSS). DESIGN: A prospective, controlled study wherein rats were subjected to bilateral carotid artery ligature (BCL), or BCL + arteriovenous fistula, or BCL + drug application. METHODS: Messenger RNA (mRNA) abundance and protein expression were determined in FSS-stimulated cerebral collaterals by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry. Drugs were applied via osmotic mini pumps and arteriogenesis was evaluated by post-mortem angiograms and Ki67 immunostaining. RESULTS: Trpv4 was the only mechanosensitive Trp channel showing significantly increased mRNA abundance and protein expression after FSS stimulation. Activation of Trpv4 by 4α-phorbol-12,13-didecanoate caused significantly enhanced collateral growth (length: 4.43 ± 0.20 mm and diameter: 282.6 ± 8.1 µm) compared with control (length: 3.80 ± 0.06 mm and diameter: 237.3 ± 5.3 µm). Drug application stimulated arteriogenesis to almost the same extent as did maximum FSS stimulation (length: 4.61 ± 0.07 mm and diameter: 327.4 ± 12.6 µm). CONCLUSIONS: Trpv4 showed significantly increased expression in FSS-stimulated cerebral collaterals. Pharmacological Trpv4 activation enhanced cerebral arteriogenesis, pinpointing Trpv4 as a possible candidate for the development of new therapeutic concepts.

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.

Kidney Failure After Occlusion of Accessory Renal Arteries in Endovascular Abdominal Aneurysm Repair.

PURPOSE: To evaluate the incidence of acute renal failure and chronic kidney disease due to occlusion of accessory renal arteries during endovascular aneurysm repair of infrarenal abdominal aortic aneurysm. MATERIAL AND METHODS: We retrospectively reviewed the course of 181 patients (mean age, 71, SD ± 9  years) who underwent EVAR of infrarenal abdominal aortic aneurysm. The renal vessel anatomy was analyzed in all pre- and postoperative CT scans. Diameter and origin of accessory renal arteries were evaluated. Renal function was determined by pre- and postoperative serum creatinine and eGFR levels. Long-term follow-up (>3 months) of patients was available in 121 cases (66.9%). Acute kidney injury and chronic kidney failure were defined according to guidelines of "Kidney Disease: Improving Global Outcomes" (KDIGO). RESULTS: In 65 of 181 patients (33.9%), 82 accessory renal arteries were identified preoperatively. In 19 of 181 patients (10.5%), one or more accessory renal arteries were covered and subsequently occluded by the implanted stent-graft device. Neither acute kidney injury (10.3% vs 12.5%; p = .785) nor chronic kidney disease (10.7% vs 15.38%; p = .452) was detected significantly more often in patients with covered accessory renal artery. The only significant predictor of acute kidney injury was the preoperative serum creatinine level (1.12 mg/dl vs. 0.98 mg/dl; p = .03). Significant predictors for chronic kidney disease were preoperative serum creatinine, eGFR, and impaired renal function (p < .001). CONCLUSION: Coverage of accessory renal artery due to stent-graft does not lead either to temporary acute kidney injury after endovascular aneurysm repair or to chronic kidney disease. LEVEL OF EVIDENCE: Level II b.

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.

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.

Inferior Mesenteric Artery Side Branch for Selected Patients with Endovascular Aortic Aneurysm Repair.

OBJECTIVE/BACKGROUND: To report on our experience of the treatment of aortic aneurysms by custom-made, branched stent-grafts with an additional inferior mesenteric artery (IMA) side branch to preserve IMA perfusion in patients at risk for colon ischemia. METHODS: Three male patients (mean age 60 years) with a thoracoabdominal, pararenal, and infrarenal aortic aneurysm (AA), respectively, were treated by endovascular aneurysm exclusion using custom-made, branched stent-grafts with a side branch to the IMA for prevention of colon ischemia. Indications for selective IMA side branch perfusion were occlusions or high-grade stenosis of the visceral or hypogastric arteries. RESULTS: No colon ischemia and no neurological deficit were observed. All three IMA side branches were perfused and patent, as documented by computed tomography scan and duplex ultrasound postoperatively and after 12 months. Patency after 24 months was documented as 2/3. CONCLUSION: Custom-made, branched stent-grafts are an endovascular option to preserve the IMA perfusion in selected, electively treated patients with an increased risk for insufficient colon perfusion due to stenosis or occlusions of visceral or hypogastric arteries.

[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.

Contrast harmonic imaging ultrasound and perfusion imaging for surveillance after endovascular abdominal aneurysm repair regarding detection and characterization of suspected endoleaks.

OBJECTIVE: Is Contrast Harmonic Imaging (CHI) comparable to computed tomography angiography (CTA) scan in detecting and characterizing suspected endoleaks after endovascular abdominal aneurysm repair in a non-selected group including reintervention procedure and branched endografts in daily practice? MATERIAL/METHODS: In a prospective study computed tomography angiography (CTA) and contrast-enhanced ultrasound (CEUS) were performed in 30 consecutive patients (26 males, 4 females, mean age: 72 years, range: 38-87) with suspected endoleaks in follow-up (mean 13 months, range: 1-95) after endovascular abdominal aneurysm repair or procedure in dissection or penetrated ulcer of the aorta (25 infrarenal, 5 suprarenal stent grafts, mean aortic diameter 56 mm, range: 27-98). CTA was supposed to be gold standard for determining the presence of endoleaks (multislice CT, collimation 16 x 0.75 mm, 100 ml of iodized contrast agent bolus). Ultrasonography used a multi-frequency probe (1-4 MHz) with the modalities of colour coded Doppler sonography (CCDS), power Doppler (PD) combined with contrast enhancement and the technique of contrast harmonic imaging (CHI) and low mechanical index (MI < 0.2). 2.4 ml of SonoVue (Bracco, Altana Pharma GmbH, Italy) were administered to each patient intravenously as a bolus injection. RESULTS: Out of 30 patients, 21 endoleaks were identified in CTA (6 type I or III, 15 type II), 22 in CHI. Thus, sensitivity for CHI was therefore 99%, its specificity 85% (Spearman correlation coefficient (CC) 0.92). In follow-up the localizations of endoleak type I or III exclusively detected by CHI were confirmed as true positive by angiography. Due to its dynamic characteristic CHI seemed to be more helpful in characterization of endoleaks than CTA. In case of a rupture after reintervention a type III endoleak leads to prompt intervention before receiving the result of the CT scan. Altogether, CHI failed to identify 1 combined type I and II endoleak (sensitivity 0.99). Both, CCDS and PD were positive only in 6/30 patients (CC 0.33 and 0.39). Interestingly the application of contrast agent doubles the detection rate of endoleaks (12/30) in CCDS and PD (CC 0.39). CONCLUSION: Contrast harmonic imaging (CHI) compared to computed tomography angiography (CTA) accurately depicts endoleaks after endovascular abdominal aneurysm repair and stent-graft procedure in dissected and ulcerated aorta. It seems to be superior in characterization of the type of endoleaks and can be established in order to reduce iodized contrast agent and radiation exposure in follow-up. In contrast to CTA scan CHI can be offered to patients with chronic renal insufficiency and allows a dynamic examination and a perfusion analysis.

[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.

Graft patency and clinical outcome of femorodistal arterial reconstruction in diabetic and non-diabetic patients: results of a multicentre comparative analysis.

OBJECTIVE: in diabetic patients with critical limb ischaemia (CLI) an inferior success rate following infrainguinal bypass surgery is quite often suggested. The aim of this retrospective analysis was, therefore, to evaluate the graft patency and, particularly, the clinical outcome at 1 year in diabetic compared with non-diabetic patients. MATERIAL AND METHODS: two hundred and eleven patients (diabetics 94; non-diabetics 117) with femorodistal reconstruction for CLI were studied. Groups were comparable with regard to the Fontaine classification, the distribution of vascular risk factors, graft material, distal anastomosis site, and the angiographic runoff grading. RESULTS: diabetes did not adversely affect graft function. For diabetics and non-diabetics primary cumulative patency rate at 1 year was found to be 66 and 56%, respectively (p=0.10) and a virtually identical limb salvage rate of 85 and 83% was achieved (p=0.76). With regard to healing of ischaemic foot ulcers a trend against diabetics was noted with a healing rate of 81% compared to 96% in non-diabetics at 1 year (p=0.067); gangrenous foot lesions could be equally remedied in 94% and in 87% among patients with and without diabetes (p=0.44). The survival rate of diabetics, however, was significantly lower with 78% at 1 year compared with 95% in non-diabetic patients (p=0.0004). CONCLUSIONS: our preliminary results support the view that infrainguinal bypass grafting can be safely done even in diabetics. Despite increased mortality in this group, liberal indication for reconstructive vascular surgery seems to be justified by favourable patency rates and clinical outcome in selected patients.