Altered renal functions in patients with occlusion of an accessory renal artery after endovascular stenting of an infrarenal aneurysm.

OBJECTIVE: Coverage of an accessory renal artery (ARA) during endovascular aneurysm repair (EVAR) may result in renal infarction (RI) or decline in renal function. Until now, it remains vague which patients are at risk to develop these complications. We therefore analyzed the effect of ARA sealing by EVAR with respect to the occurrence of RI and renal function. METHODS: A retrospective analysis of the medical records and computed tomographic scans of patients who underwent EVAR within a period of 5 years was performed. Particular attention was paid to the presence or absence of accessory renal arteries and renal function before EVAR. Thirty-four patients with ARA were matched 1:3 to 102 patients without ARA. The results after EVAR were analyzed in patients with and without ARA. In patients with ARA, we further examined the results after EVAR in patients with an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min and eGFR < 60 mL/min before EVAR. RESULTS: Before EVAR, the median eGFR was 74 mL/min (25th/75th percentiles, 57/89) in patients with ARA and 72 mL/min (25th/75th percentiles, 63/87) in patients without ARA. Alterations in eGFR were significantly pronounced in patients with ARA when compared with patients without ARA 1 week after EVAR (ARA, -10.7 ± 16.9 mL/min vs without ARA, 1.2 ± 13.3 mL/min; P = .002) and after 6 months (ARA, -10.8 ± 17.4 mL/min vs without ARA, 1.2 ± 13.3 mL/min; P = .001). RI only occurred in patients with ARA. Within the group of patients with ARA, patients with normal renal function (NF) showed a more pronounced decline in eGFR preoperatively when compared with patients with impaired renal function (IF) 1 week after EVAR (NF, -14.3 ± 18.0 mL/min vs IF, -1.3 ± 10.8 mL/min; P = .02) and after 6 months (NF, -15.8 ± 17.9 mL/min vs IF, 0.1 ± 15.2 mL/min; P = .007). CONCLUSIONS: The decrease in renal function was more pronounced in patients with ARA after EVAR when compared with patients without ARA undergoing EVAR. In patients with ARA, the observed decline in renal function was significantly distinct in patients presenting NF preoperatively. Consequently, the risk of IF after EVAR seems to be increased in patients with ARA and normal preoperative renal function.

Combined Carotid Endarterectomy and Retrograde Stenting of the Supra-Aortic Trunk: Does Cervical Block Offer Advantages?

BACKGROUND: Atherosclerosis of the carotid artery is a major source of stroke. In some cases, atherosclerosis occurs at several positions within the carotid artery. Carotid endarterectomy (CEA) in combination with retrograde balloon angioplasty and stenting of a brachiocephalic or common carotid artery stenosis has been described as efficacious and safe procedure to prevent stroke in these cases. The aim of this study was to analyze the impact of anesthetic techniques on hemodynamic factors, operation time, duration of clamping, and postoperative pain. METHODS: A retrospective analysis of patients undergoing CEA in combination with retrograde stenting under either general anesthesia (GA) or cervical block (CB) was carried out. Preoperative risk factors were analyzed as well as operating and cross-clamping time, hemodynamic factors, perioperative complications, postoperative pain, application of pain killers, and duration of intensive care unit (ICU) and hospital stay. RESULTS: Operating (GA: 193 ± 91 min vs. CB: 125 ± 52 min, P = 0.029) and cross-clamping time (GA: 34 ± 12 min vs. CB: 26 ± 9 min, P < 0.001) were shorter under CB. Patients under CB were hemodynamically more stable and required less norepinephrine (GA: 1.1 ± 0.6 mg vs. CB: 0.1 ± 0.1 mg, P < 0.001) and crystalloids (GA: 2,813 ± 1,173 mL vs. CB: 1,088 ± 472 mL, P < 0.001). Postoperative pain levels (GA: numeric rating scale 4.3/10 vs. 2.0/10; P = 0.004) and requirement of pain killers were also lower within the CB group. CONCLUSIONS: Synchronous CEA and retrograde balloon angioplasty and stenting of a brachiocephalic or common carotid artery stenosis under CB is associated with reduction of operating and cross-clamping time, improved hemodynamical stability, lower postoperative pain, shorter ICU and hospital stay, and it offers the advantage of a continuous neurological monitoring.

Typical exposure parameters, organ doses and effective doses for endovascular aortic aneurysm repair: Comparison of Monte Carlo simulations and direct measurements with an anthropomorphic phantom.

OBJECTIVES: Radiation exposure of patients during endovascular aneurysm repair (EVAR) procedures ranks in the upper sector of medical exposure. Thus, estimation of radiation doses achieved during EVAR is of great importance. MATERIAL AND METHODS: Organ doses (OD) and effective doses (ED) administered to 17 patients receiving EVAR were determined (1) from the exposure parameters by performing Monte Carlo simulations in mathematical phantoms and (2) by measurements with thermoluminescent dosimeters in a physical anthropomorphic phantom. RESULTS: The mean fluoroscopy time was 26 min, the mean dose area product was 24995 cGy cm2. The mean ED was 34.8 mSv, ODs up to 626 mSv were found. Whereas digital subtraction angiographies (DSA) and fluoroscopies each contributed about 50% to the cumulative ED, the ED rates of DSAs were found to be ten times higher than those of fluoroscopies. Doubling of the field size caused an ED rate enhancement up to a factor of 3. CONCLUSION: EVAR procedures cause high radiation exposure levels that exceed the values published thus far. As a consequence, (1) DSAs should be only performed when necessary and with a low image rate, (2) fluoroscopies should be kept as short as possible, and (3) field sizes should be minimized. KEY POINTS: • During endovascular aneurysm repair (EVAR) considerable patient doses are achieved. • For each EVAR procedure organ (OD) and effective (ED) doses were determined. • The mean ED was 34.8 mSv, the highest OD was 626 mSv. • Number of DSAs, fluoroscopy durations and field sizes should be minimized.

Treatment of type I endoleaks using transcatheter embolization with onyx.

PURPOSE: To report a single-center experience with transcatheter embolization of type I endoleaks using the liquid embolic agent Onyx, an ethylene vinyl alcohol copolymer. METHODS: Eight patients (4 men; mean age 74.8 years, range 63-86) with 10 type I endoleaks (6 abdominal and 4 thoracic) diagnosed 2 days to 9 years after endovascular repair were treated with Onyx embolization because cuff extension was precluded by an insufficient landing zone in 6 cases and an unsuitable aortic diameter in 2. Endoleaks were accessed with a 4-F diagnostic catheter and a coaxially introduced dimethylsulfoxide-compatible microcatheter. Onyx-34 was predominantly applied due to its high viscosity; patent side branches were coil embolized prior to Onyx delivery in 3 cases. RESULTS: Technical success of the procedure was achieved in all cases. The mean volume of Onyx used for abdominal endoleaks was 11.8 mL (range 3.0-25.5) and 19.4 mL (range 4.5-31.5) for thoracic endoleaks. The average duration of the procedure was 76.7 minutes (range 34.5-110.6), and the average radiation dose area product was 18.8 cGy*cm (2) (range 10.6-55.8). Reperfusion of the endoleak was detected in one case 2 days after the procedure. A second case showed an occluded endoleak but a small trace of contrast between the aortic wall and the stent-graft. Non-target embolization was not found in any case. Mean follow-up was 13.2 months (range 8-24). The mean reduction in diameters for thoracic aneurysms after 6 and 12 months was 0.4 and 0.9 cm, respectively, and 0.6 and 1.2 cm, respectively, for abdominal aneurysms. CONCLUSION: Transcatheter embolization of type I endoleaks using Onyx is a simple, safe, and sustainable treatment option with a high primary success rate for cases in which stent-graft extension is not possible. The benefit of additional coil embolization remains uncertain.

Endovascular treatment of abdominal aortic aneurysms combined with bilateral common and internal iliac aneurysms.

INTRODUCTION: Combined aneurysms of aortic and iliac arteries are rare with a prevalence of less than 0.1%. However, these combined aneurysms are associated with a high incidence of thrombosis, distal embolism, or rupture. Endovascular repair is a therapeutic option and includes embolization of the internal iliac artery in numerous cases. Embolization of the internal iliac artery may cause severe ischemia with hip and buttock complications in 2-5%. Therefore, preservation of internal iliac arteries is essential to reduce complications. PATIENT AND METHOD: We describe in detail an endovascular procedure for combined abdominal aortic (diameter of 8.6 cm) and bilateral common and internal iliac aneurysm (diameter of the left side: 6.4 cm; diameter of the right side: 4.3 cm) in a 44-year-old patient caused by media necrosis Erdheim-Gsell. The blood flow of both internal arteries was preserved in this patient. RESULT: Operation was done without any complications. Conversion to an open procedure was not necessary. During follow up (3, 6, and 12 months after operation) the patient did not develop any signs of severe hip and buttock complications. Furthermore, sonography and CT angiography revealed a good blood flow via the internal and external iliac arteries. CONCLUSION: Endovascular repair of abdominal aortic aneurysms combined with bilateral common and internal iliac aneurysms offers a promising minimal invasive procedure. Most importantly, this technique is less invasive than open operations and reduces complications by preserving the pelvic perfusion.

Penetrating aortic ulcer in the infrarenal stent-graft landing zone: treatment with coils and the ethylene vinyl alcohol copolymer onyx.

PURPOSE: To describe a technique to enable endovascular aneurysm repair in patients with penetrating aortic ulcer (PAU) in the infrarenal neck of an abdominal aortic aneurysm (AAA). TECHNIQUE: The technique is illustrated in a 76-year-old man with a 5.7-cm infrarenal AAA and a 2.3 × 1.8-cm PAU situated immediately distal to the right renal artery and covering 20% of the 28-mm-diameter proximal aortic neck. During the stent-graft repair, the PAU was successfully excluded by embolization with coils and the ethylene vinyl alcohol copolymer Onyx. The AAA and PAU were completely excluded without complications. At 6 months, there were no signs of endoleak, the AAA remained excluded, and there was no reperfusion of the Onyx cast in the PAU. CONCLUSION: This technique for treatment of a PAU in the proximal neck of an AAA is a reasonable alternative in cases involving severely diseased infrarenal necks that would otherwise require open surgery. The liquid embolic agent Onyx performed well, with fast embolization and excellent control of the growing cast maintained by the interventionist.

Visceral embolus protection by catheters with balloon-inflatable tips during hybrid repair of thoracoabdominal aortic aneurysm.

Thoracoabdominal aortic aneurysms (TAAA) are associated with high rupture rates and poor outcome in patients who do not have surgical repair. Endovascular and hybrid techniques have gained increasing acceptance for the treatment of TAAA in patients with multiple comorbidities and an increased anesthetic risk. One of the complications of endovascular repair in TAAA is procedurally related embolism to visceral vessels. Visceral embolism causes bowel ischemia and is a potentially lethal complication. This report illustrates the intermittent use of catheters with balloon-inflatable tips as visceral embolus protection systems. These catheters are easy to apply and demonstrated perfect prevention of visceral embolization. To date, 10 patients have undergone operations at our clinic using this protection system, and no embolic complications were observed at the visceral vessels. Therefore, catheters with balloon-inflatable tips for visceral embolous protection should be considered in patients undergoing a two-stage hybrid TAAA repair to avoid embolus-associated morbidity and mortality.

Idiopathic internal mammary artery aneurysm.

Aneurysms of the internal mammary artery are extremely rare, and their presentation and treatment are variable. Since these aneurysms often tend to rupture and cause haemothorax and life-threatening conditions, the knowledge of secure treatment options is indispensable. We here report the case of an idiopathic internal mammary aneurysm in a 46-year-old man. Open surgical resection of the aneurysm was performed in this case without any complications. The postoperative course was uneventful and the patient was in a good physical condition without any vascular or neurological abnormalities during follow-up.

The ox-foot-model for investigating endoluminal thermal treatment modalities of varicosis vein diseases.

The introduction of technical surgical innovations in clinical medicine is preceded by preclinical evaluation of prototypes. Surgical aspects such as energy dependent tissue response and tissue sealing to reduce bleeding are usually investigated in animal experiments. Extra-corporal organ models can provide the required experimental information without harming animals and thus reduce or even replace in vivo experiments. Here we describe the ex vivo ox-foot-model, which can be used for surgical investigations and for training purposes. In the ox-foot-model the vein remains in its anatomical bed under reproducible experimental conditions, i.e., blood perfusion, blood pressure, and temperature. Innovative endoluminal surgical procedures using laser light and radio frequency for varicosis treatment were tested. Treatment parameters were investigated systematically in a large number of samples. A standardized preclinical testing procedure could be established and optimized on the basis of acute macroscopic and histological findings. Further, optical coherence tomography could be evaluated as a time-saving diagnostic tool. The ox-foot-model is suitable for training surgical techniques relevant for the treatment of varicosis veins. It is a cost-effective alternative to conventional in vivo experiments, providing standardized experimental conditions and reproducible experimental results while respecting the Principles of Humane Experimental Techniques: Reduction, Refinement, and Replacement of animal experiments.

Rotational thrombectomy of acute peripheral vascular occlusions using the ThromCat XT device: techniques, indications and initial results.

PURPOSE: To gather initial procedural experiences with the ThromCat XT, a new rotational thrombectomy catheter primarily developed for coronary interventions. MATERIALS AND METHODS: The ThromCat XT is a 150-cm rapid exchange thrombectomy device consisting of an atraumatic tip and a steel helix with a kink-resistant covering. It was employed in native arteries, veins, grafts and stents in ten patients presenting with acute and subacute thrombembolic occlusions. RESULTS: Technical success with a restoration of flow was achieved in 70% of patients. The mean thrombectomy time was 8.0±2.33 min, and the aspirated blood volume ranged from 120 mL to 280 mL. Peripheral thrombembolism was detected in two cases, and embolic protection was applied in four cases. Vessel injuries and catheter failures were not observed in any of the cases. CONCLUSION: The ThromCat XT is an easy-to-handle, reliable and atraumatic device for the removal of fresh thrombi in native and artificial vessels. In our series, the thrombus age-especially if greater than five days-had a major impact on technical success.

Plantar vein thrombosis due to busy night duty on intensive care unit.

A 32-year-old woman with severe foot pain came to our emergency department after a busy night duty in hospital followed by an extended sleep period. Physical examination revealed a discrete swelling of the medial aspect of the right foot and a painful plantar arch during digital examination. Magnetic resonance imaging (MRI) with intravenous gadolinium showed filling defects in the lateral plantar vein. Doppler sonography displayed noncompressible structures in the plantar veins without flow signals, suggesting a plantar vein thrombosis. Therapy was initiated with low-molecular-weight heparin in combination with customized elastic bandages for the lower leg. Follow-up sonography 6 weeks later showed complete patency of the plantar veins. To our knowledge, we present the first case of isolated plantar vein thrombosis independent of trauma, surgery, or malignant disease, most probably caused by a busy night duty on the intensive care unit (ICU) followed by a prolonged sleeping period.

Endovenous laser therapy--application studies and latest investigations.

Endovenous laser therapy (ELT) was introduced in clinical practice as a therapy for incompetent veins about ten years ago. One characteristic of ELT is the broad spectrum of different treatment protocols by means of a variety of laser systems as well as manifold application forms and dosimetry concepts are under investigations. Clinical results with effective, relatively pain-free occlusion of incompetent varicosis veins have been observed, as well as undesired side effects such as ecchymosis, phlebitis and recanalization. In recent years systematic experimental investigations and the analysis of clinical results have increased the understanding of the interrelation between the clinical and physical aspects, followed to a continuous optimization of ELT. The use of IR wavelengths and radial irradiation concepts, together with continuous moving of the optical fiber seem to reduce possible side effects. This way ELT treatment becomes a more standardized effective method for the treatment of varicose veins. In future controlled randomized studies are required to compare optimized ELT treatment with other endoluminal modalities as well as conventional surgery.

Thoracic Outlet Syndrome Caused by a Pseudoaneurysm After Pseudarthrosis of the Clavicle.

Clavicle fractures are common, with the majority treated conservatively. If treated conservatively, pseudarthrosis of the clavicle is reported in up to 3% of the cases. In rare cases, pseudarthrosis of the clavicle may cause pseudoaneurysm formation, resulting in compression of the brachial plexus and the adjoining vessels, which may produce neurological symptoms and circulatory disorders. Here, we describe two cases of the late onset of pseudoaneurysm formation after pseudarthrosis of the clavicle. Both cases were remarkable because they showed clinical symptoms of TOS. Therefore, surgical treatment was performed and included claviculectomy, resection of the pseudoaneurysm and interposition grafting with an artificial prosthesis. One year after the operation, both patients showed excellent upper extremity function without any deficit of vascular, sensorial or motorial function. Patient's history and radiological findings are the keys to diagnosis. Without treatment, the prognosis is poor with spontaneous development of bleeding or gangrene. Therefore, surgical treatment has to be performed, especially when neurological symptoms occur.

Large external iliac vein aneurysm in a patient with a post-traumatic femoral arteriovenous fistula.

We report about a young patient with a large aneurysm of the left external iliac vein associated with a traumatic arteriovenous fistula between the left superficial femoral artery and the femoral vein after a stab wound 20 years ago. The patient presented with swelling of the left leg, which developed during the past years and worsened after saphenectomy 12 months before hospital admission. The chronically hyperperfused common iliac artery proximal to the arteriovenous fistula was compressing the common iliac vein. The venous outflow obstruction and subsequent venous hypertension render a possible explanation for the formation of the iliac vein aneurysm. Surgical repair of the venous aneurysm by interposition grafting and closure of the arteriovenous fistula was successful. A postoperative computed tomography scan showed a 50% size reduction of the feeding artery, underlining the ability of the arterial system to normalize arterial diameter in response to flow reduction, even after a high flow situation had existed for probably >20 years.

Evaluation of endovenous radiofrequency ablation and laser therapy with endoluminal optical coherence tomography in an ex vivo model.

BACKGROUND: This study evaluated the ability of endovascular optical coherence tomography (eOCT) to detect qualitative tissue alteration and quantitative changes of vein wall thickness and vein lumen diameter comparing endovenous radiofrequency ablation (RFA) and endovenous laser therapy (ELT) in an established ex vivo model. METHODS: Endoluminal eOCT was performed by means of a new prototype rotating system (System M1, LightLab Imaging Inc, Boston, Mass) with automatic pullback of 1 mm/s. In the course of an eOCT examination of a 50-mm vein segment, 264 electronic cross section images with a spatial resolution of 15 to 20 mum are acquired. The eOCT scans were performed before and after treatment of each of 13 treated vein segments and of six control vein segments. Thirteen subcutaneous cow foot veins were reperfused in situ, and the defined 50-mm vein segments in the study were treated with RFA (n = 2) and ELT (n = 11). RFA followed the clinical VNUS-Closure protocol (VNUS Medical Technologies, San Jose, Calif) using a 6F 60-mm Closure-Plus catheter. ELT was performed using light of lambda = 980 nm with a laser power of 3 (n = 2), 5 (n = 2), and 7 W (n = 4) with a paced pullback protocol with laser irradiation for 1.5 seconds every 3 mm, resulting in linear endovenous energy densities (LEED) of 15, 25, and 35 J/cm. Using 11 W (n = 3) with a continuous pullback protocol at 3 mm/s resulted in a LEED of 36.5 J/cm. Ten histologic cross sections of each treated and control vein segment were correlated with the corresponding eOCT cross sections to evaluate qualitative representation of vein wall layers and tissue alterations such as ablation and vein wall perforation. In addition, 26 eOCT cross sections of every treated vein segment before and after treatment and every control vein segment were analyzed to calculate quantitative changes in media thickness and vein lumen diameter. RESULTS: In all specimens, qualitative analysis with eOCT demonstrated a clear match with histologic cross sections. A symmetrical, complete, circular disintegration of intima and media structures, without any transmural tissue defects, was shown after RFA. Pronounced semicircular tissue ablations (3 to 14 per 50 mm) and complete vessel wall perforations (0 to 16 per 50 mm) were detected after ELT. The quantitative analysis demonstrated a significant (P < .0001) increase in intima-media thickness after RFA (37.8% to 66.7%) and ELT (11.1% to 45.7%). A significant (P < .0001) reduction of vessel lumen diameter (36.3% to 42.2%) was found after RFA. Owing to the limited number of treated vein segments and inhomogeneous baseline vein lumen diameters, no linear correlation between laser energy level and effects on tissue such as ablation/perforation, media thickening, or vein lumen diameter could be identified. CONCLUSIONS: In our ex vivo cow foot model, eOCT is able to reproduce normal vein wall structures and endovenous acute thermal alterations, such as tissue ablation and vessel wall perforations. Endovenous eOCT images can also be analyzed quantitatively to measure media thickness or vein lumen diameter. Endovascular OCT could become a valuable alternative tool for morphologic investigation of tissue alterations after endovenous thermal procedures.