Hardy Schumacher

Morphometry and classification in abdominal aortic aneurysms: patient selection for endovascular and open surgery.

Purpose: To evaluate the anatomic morphology of abdominal aortic aneurysms (AAAs) and compose a classification system to facilitate patient selection for endovascular graft (EVG) repair. Methods: Data on 242 consecutive AAA patients evaluated on a nonemergent basis in a 3.5-year period to July 1996 were prospectively entered into a registry. Patients were examined using sequential intravenous spiral computed tomographic angiography and intraarterial digital subtraction angiography. The data collected and analyzed included: diameters of the supra- and infrarenal aorta, aneurysm, aortoiliac bifurcation, and iliac arteries; lengths of the proximal neck, distal cuff, and aneurysm; degrees of iliac artery tortuosity; and occlusion of the visceral, renal, or iliac arteries. Results: The 242 aneurysms could be easily grouped into three distinctive categories related to the extent of the aneurysmal disease. Type I AAAs (11.2%) had nondilated, thrombus-free infrarenal (15 mm) necks and distal (10 mm) cuffs appropriate for EVG anchoring. In type II and its subgroups (72.3%), a sufficient proximal neck was present, but the aneurysm extended into the iliac arteries; 56% of these were eligible for a bifurcated endograft. In type III (16.5%), a sufficient proximal neck was missing, independent of distal involvement. In all, 51.7% were good EVG candidates based on AAA morphology. Taking into consideration relevant concomitant vascular diseases, proximal iliac kinking, and iliac, renal, or visceral occlusive disease, only 30.2% of the population were potential candidates for an efficient and secure EVG repair using the devices currently available. Conclusions: In contrast to classical open repair, detailed preoperative measurements are recommended for EVG planning. The use of liberal EVG indications may lead to a higher incidence of complications, whereas restrictive morphology-based selection criteria may offer excellent results.

Endovascular Repair of Acute Uncomplicated Aortic Type B Dissection Promotes Aortic Remodelling: 1 Year Results of the ADSORB Trial

OBJECTIVES Uncomplicated acute type B aortic dissection (AD) treated conservatively has a 10% 30-day mortality and up to 25% need intervention within 4 years. In complicated AD, stent grafts have been encouraging. The aim of the present prospective randomised trial was to compare best medical treatment (BMT) with BMT and Gore TAG stent graft in patients with uncomplicated AD. The primary endpoint was a combination of incomplete/no false lumen thrombosis, aortic dilatation, or aortic rupture at 1 year. METHODS The AD history had to be less than 14 days, and exclusion criteria were rupture, impending rupture, malperfusion. Of the 61 patients randomised, 80% were DeBakey type IIIB. RESULTS Thirty-one patients were randomised to the BMT group and 30 to the BMT+TAG group. Mean age was 63 years for both groups. The left subclavian artery was completely covered in 47% and in part in 17% of the cases. During the first 30 days, no deaths occurred in either group, but there were three crossovers from the BMT to the BMT+TAG group, all due to progression of disease within 1 week. There were two withdrawals from the BMT+TAG group. At the 1-year follow up there had been another two failures in the BMT group: one malperfusion and one aneurysm formation (p = .056 for all). One death occurred in the BMT+TAG group. For the overall endpoint BMT+TAG was significantly different from BMT only (p < .001). Incomplete false lumen thrombosis, was found in 13 (43%) of the TAG+BMT group and 30 (97%) of the BMT group (p < .001). The false lumen reduced in size in the BMT+TAG group (p < .001) whereas in the BMT group it increased. The true lumen increased in the BMT+TAG (p < .001) whereas in the BMT group it remained unchanged. The overall transverse diameter was the same at the beginning and after 1 year in the BMT group (42.1 mm), but in the BMT+TAG it decreased (38.8 mm; p = .062). CONCLUSIONS Uncomplicated AD can be safely treated with the Gore TAG device. Remodelling with thrombosis of the false lumen and reduction of its diameter is induced by the stent graft, but long term results are needed.

Endovascular aortic arch reconstruction with supra-aortic transposition for symptomatic contained rupture and dissection: early experience in 8 high-risk patients.

Purpose: To report our initial experience with total and subtotal endovascular aortic arch reconstruction combined with supra-aortic vessel transposition in high-risk patients and to present a new morphological classification of thoracic aortic lesions for patient and procedure selection. Methods: Among 80 patients treated with thoracic stent-grafts at our department between 1997 and 2003, 8 patients (6 men; mean age 71 years, range 45–81) unfit for open repair were not candidates for standard endovascular repair due to inadequate proximal landing zones on the aortic arch. Commercially available endografts (Excluder, Zenith, Endofit, Talent) were used to repair the arch after supra-aortic vessel transposition was performed. The endograft was implanted transfemorally or via an iliac Dacron conduit graft with standardized endovascular techniques and deployed during intravenous adenosine-induced asystole. The imaging data from all thoracic endograft patients was analyzed to classify thoracic and thoracoabdominal lesions according to a 4-level anatomical system. Results: Deployment success was 100% after staged supra-aortic vessel transposition, but 1 patient died of endograft-related rupture of the proximal aortic arch. There was no neurological complication. Mean follow-up was 16 months (range 1–36). Patency of all endografts and conventional bypasses was 100%, and no migration was observed. One minor type II endoleak was demonstrated. Conclusions: Initial results are encouraging for endovascular aortic arch repair in combination with supra-aortic transposition in selected high-risk patients with complex aortic pathologies.

Inducible nitric oxide synthase is present in human abdominal aortic aneurysm and promotes oxidative vascular injury

OBJECTIVE Nitric oxide (NO), catalyzed by inducible NO synthase (iNOS), may be important in the pathophysiologic characteristics of many vascular diseases. Although there is indirect evidence to support the presence of iNOS in abdominal aortic aneurysm (AAA) in human beings, no definitive study has confirm this finding. The present study was designed to assess expression of iNOS in AAA in human beings. Furthermore, the activity of iNOS and the oxidative vascular injury initiated by iNOS were assessed with detection of nitrotyrosine, which is a marker indicative of formation and activity of the NO-derived oxidant peroxynitrite. METHODS We studied 25 patients with AAA and 10 patients with normal abdominal aortas. In situ hybridization and immunohistochemistry were used in tissue sections to localize iNOS messenger RNA (mRNA) and protein. Double staining with a combination of in situ hybridization and immunohistochemistry was used to simultaneously demonstrate iNOS mRNA expression and its cellular localization. The presence of peroxynitrite was indirectly assessed with immunostaining with anti-nitrotyrosine antibodies. RESULTS In situ hybridization and immunohistochemistry confirmed the presence of iNOS in media and adventitia of AAA in all 25 patients. Specific cell markers identified iNOS mRNA-positive cells mainly as T and B lymphocytes, macrophages, and smooth muscle cells. Positive immunostaining for nitrotyrosine was present in macrophages and smooth muscle cells. Normal abdominal aorta demonstrated virtually no iNOS or nitrotyrosine expression. CONCLUSION Stimulated expression of iNOS is associated with degeneration of AAA in human beings, and the activity of this enzyme under such conditions preferentially promotes formation and activity of peroxynitrite and further contributes to oxidative tissue and cellular injury in AAA. This may be important in the pathogenesis of AAA.

Carotid endarterectomy and intracranial thrombolysis: Simultaneous and staged procedures in ischemic stroke

PURPOSE The feasibility and safety of combining carotid surgery and thrombolysis for occlusions of the internal carotid artery (ICA) and the middle cerebral artery (MCA), either as a simultaneous or as a staged procedure in acute ischemic strokes, was studied. METHODS A nonrandomized clinical pilot study, which included patients who had severe hemispheric carotid-related ischemic strokes and acute occlusions of the MCA, was performed between January 1994 and January 1998. Exclusion criteria were cerebral coma and major infarction established by means of cerebral computed tomography scan. Clinical outcome was assessed with the modified Rankin scale. RESULTS Carotid reconstruction and thrombolysis was performed in 14 of 845 patients (1.7%). The ICA was occluded in 11 patients; occlusions of the MCA (mainstem/major branches/distal branch) or the anterior cerebral artery (ACA) were found in 14 patients. In three of the 14 patients, thrombolysis was performed first, followed by carotid enarterectomy (CEA) after clinical improvement (6 to 21 days). In 11 of 14 patients, 0.15 to 1 mIU urokinase was administered intraoperatively, ie, emergency CEA for acute ischemic stroke (n = 5) or surgical reexploration after elective CEA complicated by perioperative intracerebral embolism (n = 6). Thirteen of 14 intracranial embolic occlusions and 10 of 11 ICA occlusions were recanalized successfully (confirmed with angiography or transcranial Doppler studies). Four patients recovered completely (Rankin 0), six patients sustained a minor stroke (Rankin 2/3), two patients had a major stroke (Rankin 4/5), and two patients died. In one patient, hemorrhagic transformation of an ischemic infarction was detectable postoperatively. CONCLUSION Combining carotid surgery with thrombolysis (simultaneous or staged procedure) offers a new therapeutic approach in the emergency management of an acute carotid-related stroke. Its efficacy should be evaluated in interdisciplinary studies.

Emergency Carotid Endarterectomy

Objective: Evaluation of the therapeutical efficacy of emergency carotid endarterectomy (CEA) in neurologically unstable patients. Patients and Methods: Three groups of a consecutive series of 71 emergency CEAs performed from 1980 to July 1998 were classified: (1) acute onset of severe stroke (n = 16), (2) progressive stroke/stroke in evolution (n = 34), and (3) crescendo transient ischemic attacks (n = 21). Cerebral coma, cerebral haemorrhage, and major ischemic stroke established in cranial computed tomography scans were contraindications for surgery. The neurological outcome was assessed by the modified Rankin scale. Long-term survival and long-term stroke recurrences were analyzed. Results: The recovery/minor stroke rates (Rankin 0–3) in acute stroke, progressive stroke, and crescendo transient ischemic attacks were 56.3, 76.4 and 80.9%, respectively; the combined major stroke/mortality rates (Rankin 4–6) were 43.7, 23.6 and 19.1%, respectively. Intraoperative angiography in 39 patients detected early carotid reocclusions in 2 and intracranial embolism in 7 patients. Local application of thrombolytic agents (n = 5) may contribute to a better neurological outcome in emergency CEA. Life table probabilities of major strokefree survival were 74.5, 71.6, and 53.7% after 1, 2, and 5 years, respectively (including perioperative strokes). Life table probabilities to suffer no stroke recurrence during follow-up were 96.7, 96.7 and 85.3%, respectively (perioperative strokes excluded). Conclusions: Emergency CEA may be worthwhile in selected patients. Completion angiography is mandatory. Emergency CEA should be included in therapeutic strategies for ischemic stroke.

Early and Midterm Results after Open and Endovascular Repair of Ruptured Abdominal Aortic Aneurysms in a Comparative Analysis

Purpose: To compare early and midterm results of open versus endovascular aortic repair of ruptured abdominal aneurysms (rAAA). Methods: A retrospective analysis was performed of 58 consecutive patients with rAAA who were treated with open or endovascular aneurysm repair (EVAR) at a single center between January 2000 and December 2005. Patients without definitive signs of rupture (symptomatic patients) were excluded from the study. Twenty-nine patients (21 men; median age 71 years) were treated using endovascular techniques (EVAR group) and 29 (28 men; median age 71 years) with open repair (OR group). The hemodynamic status at the time of admission was evaluated with respect to blood pressure, pulse rate, and hemoglobin level to reduce selection bias. Patients underwent followup by clinical examination and computed tomography. Results: The 30-day mortality rate was 31% (9/29) in each group (p=1.0); the morbidity rates also did not differ between groups [16 (55.2%) EVAR vs. 18 (62.1%) OR; p=0.9]. There was 1 (3.4%) primary conversion in the EVAR group and 7 (24.1%) endoleaks [3 (10.3%) primary; 4 (13.8%) secondary]. There was no difference between the groups with regard to intensive care unit stay (4 days for EVAR vs. 3 days for OR, p=0.98) or total hospital stay (9 days for EVAR vs. 12 days for OR, p=0.69). After a mean followup of 40.25 months (range 1–70), the midterm mortality rates did not differ [5 (17.2%) EVAR vs. 3 (10.3%) OR, p=0.41]. Conclusion: EVAR of rAAAs is feasible, with equal early and midterm mortality rates compared to open repair. When a defined patient selection is used for rupture, including hemodynamic status, there is no evidence of a better outcome with EVAR in emergency cases.

Endoluminal Stent-Graft Repair of Aortobronchial Fistulas: Bridging or Definitive Long-Term Solution?

PURPOSE To describe our experience with endoluminal stent-graft repair of aortobronchial fistulas (ABF) and to analyze midterm results focusing on late chronic graft infections, secondary conversion, and survival. METHODS The records of 8 patients (6 men; mean age 69 years, range 28-88) treated between March 1997 and October 2003 for traumatic and postsurgical ABFs were reviewed. Seven presented with hemoptysis and 1 with hemorrhagic shock. According to the severity of emergency, patients underwent computed tomography, angiography, bronchoscopy, and transesophageal echocardiography. Preoperatively, no clinical signs of infection were evident. Two different stent-graft models (Talent and Excluder) were implanted using standard endovascular techniques. RESULTS Procedural and clinical success was achieved in all patients. Paraplegia, secondary intervention, conversion, or procedure-related death was not observed. Mean follow-up was 30 months (range 0.6-77). One patient with a postsurgical ABF (Dacron tube graft) successfully treated with an Excluder stent-graft died 13 months later from hemorrhage secondary to aortoesophageal fistula repair procedures. A second patient died from pneumonia after 42 months. A third patient, in whom 2 Talent stent-grafts had been implanted to treat an ABF from the false lumen of a type B dissection, died 7 months later from massive hemorrhage. CONCLUSIONS Endoluminal stent-grafting of ABF is feasible and the preferred method of treatment. Secondary conversion due to endograft infection is not absolutely mandatory, but close surveillance is necessary.

3-D Quantification of the Aortic Arch Morphology in 3-D CTA Data for Endovascular Aortic Repair

We introduce a new model-based approach for the segmentation and quantification of the aortic arch morphology in 3-D computed tomography angiography (CTA) data for thoracic endovascular aortic repair (TEVAR). The approach is based on a model-fitting scheme using a 3-D analytic intensity model for thick vessels in conjunction with a two-step refinement procedure, and allows us to accurately quantify the morphology of the aortic arch. Based on the fitting results, we additionally compute the (local) 3-D vessel curvature and torsion as well as the relevant lengths not only along the 3-D centerline, but particularly also along the inner and outer contour. These measurements are important for preoperative planning in TEVAR applications. We have validated our approach based on 3-D synthetic as well as 3-D MR phantom images. Moreover, we have successfully applied our approach using 3-D CTA datasets of the human thorax and have compared the results with ground truth obtained by a radiologist. We have also performed a quantitative comparison with a commercial vascular analysis software.

Early surgical outcome after failed primary stenting for lower limb occlusive disease.

Purpose: To evaluate the early results of revascularization after failed primary stent placement for lower limb occlusive disease. Methods: A retrospective review was conducted of 25 consecutive patients (16 men; mean age 65 years, range 32–89) treated between January 2001 to October 2003 for infrainguinal stent failure at a median 6.6 months (range 3–60) after primary stent implantation (27 femoropopliteal and 20 popliteal-crural) at referring hospitals. All surgical procedures for stent failure were performed at tertiary centers. The results of bypass grafting for failed stenting were compared to a contemporaneous cohort of patients undergoing primary bypass surgery performed by the same surgeons. Results: At the time of admission, 22 stents were thrombosed, and 3 patent stents presented with >50% in-stent stenosis. Twenty patients had 7 femoropopliteal or 9 femorodistal vein bypasses and 4 reconstructions of the common femoral or profunda femoris artery. Four patients had 3 primary amputations and 1 lumbar sympathectomy. One patient with claudication was treated conservatively. Procedure-related complications were observed in 40%; 30-day mortality was 4% (1/25). Early (30-day) graft thrombosis occurred in 6 (30%) of 20 arterial reconstructions, necessitating 8 secondary amputations (44% [11/25] overall amputation rate). A total of 47 surgical procedures were performed in the 24 surviving patients (median 2 operations per patient, range 1–9) over an 11-month period (range 1–57). Primary patency rates at 30 days and at 6 and 12 months were 67%, 44%, and 33%, respectively, in the poststent bypass cohort versus 98%, 96%, and 88%, respectively, in a contemporaneous group of patients treated with primary bypass grafting. Conclusions: Failed stents in lower limb arteries often require distal reconstructive bypass surgery, which is associated with high complication rates and poor outcome, including major amputations. There is no scientific evidence to support stenting below the inguinal ligament.