Serious complications following endovascular thoracic aortic stent-graft repair for type B dissection.

OBJECTIVE: To describe our experience with endovascular stent-graft repairs in type B aortic dissection focusing on serious secondary complications resulting in immediate or late conversion to open repair. METHODS: From November 1997 to May 2007, 28 patients underwent a thoracic endovascular stent-graft procedure for acute symptomatic type B dissection at our institution. Indication for endovascular repair at our department is a complicated course of type B dissection, including thoracic aortic rupture, suspicion of impending rupture, visceral and/or peripheral ischemia, uncontrollable hypertension, and severe therapy-resistant pain. Median follow-up time was 48.3 months (range 2-97 months). RESULTS: Secondary complications with indication for a secondary intervention occurred in 5/28 patients, resulting in additional procedures in 4 patients. One patient declined any further therapy. Conversion to an open procedure was performed in four patients, one due to type I endoleak followed by retrograde type A dissection, and three due to retrograde type A dissection. One of these patients had an additional stent-graft procedure performed due to a type III endoleak 20 months post stent grafting. Retrograde type A dissection occurred 39 months later, finally leading to conversion to an open procedure. Open surgery was performed in four patients after 3, 26, 29, and 1170 days post stent-graft placement and was successful in three patients. The fourth patient died 3 months post-surgically due to multi-organ failure. The procedure-related mortality rate following secondary complications was (1/5) 20%. CONCLUSIONS: Endovascular stent-graft repair of the thoracic aorta is an alternative to surgical repair, however not without significant morbidity and mortality. Potentially lethal complications, acute or delayed, may occur.

Evaluation of subclinical cerebral injury and neuropsychologic function in patients undergoing carotid endarterectomy.

We examined subclinical alterations of cerebral function during carotid endarterectomy (CEA) and predictability of minor cerebral damage by perioperative levels of biochemical markers of brain damage (S100B and neuron-specific enolase [NSE]). Twenty consecutive patients with > or =70% asymptomatic carotid stenosis undergoing elective CEA were enrolled. Pre- and postoperative testing included magnetic resonance imaging (MRI) of the head, a standardized neurological exam, a battery of neuropsychological tests, and measurement of serum levels of S100B and NSE. There were no major ischemic strokes. In one patient, a mild weakness of the contralateral lower extremity was discovered on neurological examination; in another individual, postoperative MRI revealed two new small subcortical lesions without clinical correlate. While S100B increased significantly early after opening of the carotid clamp (p = 0.015), the NSE increase did not reach statistical significance. As a group, participants obtained a significantly higher mean overall neuropsychological score at follow-up testing (p < 0.05). In one patient, a significant decline of cognitive function was observed. This was the only individual to obtain a consistently high S100B and NSE increase. Neuropsychological testing combined with measurements of S100B and NSE may improve sensitivity when assessing subtle cerebral damage following CEA.

Long-term results of laparoscopic Heller myotomy with partial fundoplication for the treatment of achalasia.

BACKGROUND: Treatment options for achalasia include medications, endoscopic balloon dilation, injection of botulinum toxin, or surgery. METHODS: The clinical course of 75 consecutive patients who underwent minimally invasive Heller myotomy and partial fundoplication for achalasia between 1991 and 2001 was reviewed by means of a questionnaire. RESULTS: Mean follow-up was 5.3 (range .8 to 10.9) years. Sixty-four percent of questionnaires were returned. Thirty-seven patients (84%) felt much better and 6 (14%) slightly better; 1 (2%) rated the result as unchanged. Twenty-six patients (59%) experienced weight gain. Seven patients (16%) had persistent swallowing problems and 5 (11%) reported frequent reflux. Twenty-five percent underwent additional therapy, including dilation (n = 8, 18%), repeat surgery (n = 2, 5%), and botulinum toxin injection (n = 2, 5%). Eighteen patients (41%) were using a proton pump inhibitor or H2 blocker, three were on a calcium channel blocker (7%), and 1 was using nitroglycerine (2%). CONCLUSION: Laparoscopic Heller myotomy can achieve short- and long-term results comparable to open surgery and should be considered the treatment of choice for patients suffering from achalasia. Despite the frequent need for further therapy, patient satisfaction is good.

Midterm results of a single-center experience with commercially available devices for endovascular aneurysm repair.

PURPOSE: To review the outcome of endovascular abdominal aortic aneurysm repair (EVAR) using commercial stent graft devices. METHODS: Retrospective review of 167 EVAR procedures using different commercial devices at a single center between 1999 and 2003. Analysis included preoperative patient morbidities, operative and hospitalization data, postoperative complications, procedural outcome and midterm patient survival. Data are expressed as mean +/- SD and total number (%). P-values = 0.05 were considered significant. RESULTS: A total of 153 men and 14 women (mean age 75.0 +/- 7.3 years, range 53.1-89.2 years) underwent EVAR. Technical success rate was 97.0%. Postoperative intensive care unit stay was 0.05 +/- 0.24 days and hospital stay was 4 +/- 1.84 days. Postoperative complications occurred in 25 patients (15.0%). Two patients had to be readmitted within 30 days. Median follow-up time was 16.0 months (0-48 months). Overall mortality rate was 9.6% and did not depend on the type of endograft used (p=0.287). No early or aneurysm-related deaths or aneurysm ruptures occurred. Clinical success rate was 91.6% (153 patients). Graft limb thrombosis occurred in 5 patients (3.0%), all with the AneuRx device (p=0.041). Graft migration was seen in 3 devices (1.8%). There were 36 endoleaks (20.4%), specifically 30 branch vessel (type II) and 6 junctional (type I) endoleaks. Early endoleaks occurred in 21 patients (12.5%) and late endoleaks in 15 (9.0%). Twenty-two patients (13.0%) required secondary procedures (75.0% catheter-based vs. 25.0% surgical). Three patients (1.8%) underwent conversion to open aortic repair, 2 (1.0%) within the first year after EVAR. Aneurysm sac stabilization or shrinkage (> or = 5 mm reduction in transverse aneurysm diameter) occurred in 98.2% of patients; aneurysm shrinkage rate was 39.6% at 1 year, 68.74% at 2 years and 79.96% at 3 years after the procedure. Time to aneurysm shrinkage was longest with the AneuRx (1.96 +/- 0.18 years) and Talent (1.67 +/- 0.53 years) devices, compared to the Zenith (1.01 +/- 0.13 years), Ancure (0.95 +/- 0.14 years) and Excluder (0.25 +/- 0.17 years) stent grafts (p=0.0001). CONCLUSION: Endovascular aortic aneurysm repair using commercially manufactured devices is safe and effective, especially in patients at high risk for open aneurysm resection. While evolving endovascular experience has significantly decreased complication and secondary intervention rates, close long-term follow-up remains mandatory to detect late complications. Elective and unbiased use of all available surgical and interventional procedures is required to maintain long-term clinical success after EVAR.

Vascular ring causing tracheal compression in an adult patient.

A 65-year-old woman was referred for evaluation because of a few years' history of inspiratory obstruction without dysphagia. A right aortic arch with mirror image bracheocephalic vessels narrowing the trachea was considered to be the reason for the dyspnea. Immediate decompression of the trachea and symptomatic relief was achieved through surgical treatment.

Changes in abdominal aortic aneurysm size after endovascular repair with Zenith, AneuRx, and custom-made stent-grafts.

The aim of this study was to determine the maximal aneurysm diameter (MAD), the total aneurysm volume (TAV), the intra-aneurysm vascular channel (IAVC), and total thrombus volume (TTV) and compare changes in those parameters during a 12-month time period. In addition, these parameters for three different endovascular grafts were compared. A retrospective review of 42 patients who had undergone endovascular aneurysm repair (EVAR) between July 1999 and March 2001, and without evidence of an endoleak or migration, was performed. The minimum follow-up in this group was 12 months. The three grafts deployed were Dacron-stainless steel bifurcated grafts with suprarenal fixation [Zenith; Cook, Inc. (n = 14)], Dacron stainless steel aorto uni-iliac grafts with suprarenal fixation [custom-made (n = 10)], and externally supported Dacron nitinol bifurcated grafts [AneuRx; Medtronic, Inc. (n = 18)]. Volumetric measurements were obtained from CT images performed preoperatively, at 1 month and 12 months thereafter, using a 3-D Magicview 1000 workstation (Siemens, Inc.). Regardless of the type of endograft, a significant change in MAD and TAV (P = 0.008), IAVC (P = 0.031), and TTV (P = 0.001) was observed over the 12-month postoperative period. Both maximum diameter and total aneurysm volume appear to reflect accurately successful aneurysm exclusion. We conclude that both two-dimensional, maximal aneurysm diameter and three-dimensional, total aneurysm volume accurately reflect changes in morphology after endovascular aneurysm repair.

A comparison of AneuRx aortic cuff and zenith distal flare exclusion of common iliac artery ectasia for endovascular aneurysm repair.

Stent-grafts are ideally terminated within the common iliac artery (CIA). However, CIA ectasia may require hypogastric artery occlusion, with stent-graft extension to the external iliac artery. Alternatively, the diameter of the distal stent-graft may be increased, or flared, to allow exclusion of the abdominal aortic aneurysm. This report details the authors' experience with this technique. Forty-one patients received bifurcated stent-grafts (BSG): 20 received an AneuRx device, and 21 received a Zenith device. CIA ectasia (diameter 15-25 mm) was treated with a distal flare of 2-4 mm greater than the CIA diameter. Patients were followed up with computed tomography scan at 1, 6, and 12 months. Statistical analysis was performed using ANOVA within groups and unpaired two-tailed t test between groups. A p value of < 0.05 was considered significant. Eight of 20 patients (40%) (11 CIA) received an AneuRx device and 13/21 (62%) (17 CIA) received a Zenith device, with a distal flare. Values are (n) mean (mm) +/- SE. There were no deaths, endoleaks, migrations, or conversions to open repair. Follow-up mean was 24.7 and 20.6 (range 15-28) months for AneuRx and Zenith groups, respectively. In comparing initial and 12-month CIA diameters, AneuRx grafts 20 +/-0.8 vs 21.5 +/-1.0 were not significantly different, p = 0.2, nor was the same comparison for Zenith, 17 +/-0.5 vs 19.1 +/-0.4, significant, p = 0.57. At a mean follow-up of 12 months, distal flare of iliac limbs with either AneuRx or Zenith devices affords a seal for CIA ectasia and/or aneurysms complicating EVAR.

Natural history of the iliac arteries after endovascular abdominal aortic aneurysm repair and suitability of ectatic iliac arteries as a distal sealing zone.

PURPOSE: To investigate the natural history of dilated common iliac arteries (CIA) exposed to pulsatile blood flow after endovascular abdominal aortic aneurysm repair (EVAR) and the suitability of ectatic iliac arteries as sealing zones using flared iliac limbs. METHODS: Follow-up computed tomograms of 102 CIAs in 60 EVAR patients were investigated. Diameter changes in CIAs < or =16 mm (group 1) were compared with changes in vessels where a dilated segment >16 mm in diameter continued to be exposed to pulsatile blood flow (group 2). Within group 2, cases in which the stent terminated proximal to the dilated artery segment (2a) were compared with those that had been treated with a flared limb (2b). RESULTS: The mean CIA diameter increased by 1.0+/-1.0 mm in group 1 (p<0.001 versus immediately after EVAR) and by 1.5+/-1.7 mm in group 2 (p<0.001 versus immediately after EVAR) within an average follow-up of 43.6+/-18.0 months. Diameter increase was more pronounced in dilated CIAs (p=0.048), and it was not significantly different between groups 2a and 2b (p=0.188). No late distal type I endoleak or stent-graft migration associated with CIA ectasia was observed. CONCLUSION: Dilatation of the CIA is significant after EVAR, and it is more pronounced in ectatic iliac arteries. Although ectatic iliac arteries appear to be suitable sealing zones in the short term, continued follow-up is mandatory.

Effect of age and gender on restenosis after carotid endarterectomy.

Several studies have suggested that the benefits of CEA may be gender-dependent. The purpose of this study was to focus on age and gender outcomes after CEA. Three hundred seventy-two CEAs were performed in 344 patients (115 females, 229 males; mean age 72.9 years). Mean follow-up was 25.8 months. Data were collected retrospectively by chart review, and follow-up data were obtained by clinical examination and duplex ultrasound. Recurrent stenosis was defined as >50% and/or occlusion. Three hundred and seventy-two CEAs were performed in 120 female and 252 male carotid arteries: 97.3% of patients underwent patch angioplasty (bovine pericardium 71.5%, Dacron 21.8%, vein 3.8%, and polytetrafluoroethylene 0.3%) and 2.7% of patients underwent eversion endarterectomy. Perioperative mortality rate (30-day) was 0.8% (0% of females vs. 1.2% of males), and stroke rate was 0.5% (1.7% of females vs. 0% of males), with no significant gender difference (p = 0.554 and p = 0.103, respectively). Follow-up ultrasound revealed 21 (7%) restenoses (>50%) and/or occlusions, with a significantly higher rate of restenosis in females (14% vs. 3.9% in males, p = 0.008) and in patients <70 years of age at time of surgery (p = 0.003). There was no age difference between women and men with restenosis. Although there was no statistical difference in occurrence of restenosis between Dacron and bovine patch (p = 0.62), females who underwent patch angioplasty with Dacron were more likely to develop restenosis (p = 0.052). CEA is a low-risk procedure for significant carotid stenosis; however, females are more likely to develop restenosis after carotid surgery, especially with Dacron patches. Younger patients appear to be at a higher risk of restenosis after surgery.

Paravertebral blockade with propofol sedation versus general anesthesia for elective endovascular abdominal aortic aneurysm repair.

The objective of this study was to evaluate the applicability of paravertebral blockade (PVB) for endovascular abdominal aortic aneurysm repair compared with general anesthesia (GA). Data from patients who underwent elective infrarenal endovascular abdominal aortic aneurysm repair between August 2001 and July 2002 using PVB or GA were retrospectively reviewed and compared with respect to risk factors, intraoperative hemodynamic characteristics, operative outcome, and complications. Ten patients underwent elective infrarenal endovascular abdominal aortic aneurysm repair under PVB, whereas 15 patients were operated on under GA. One conversion from PVB to GA was necessary for block failure. The perioperative (< 30 days) cardiovascular morbidity and overall mortality were zero in both groups. The PVB group benefited significantly with respect to the incidence of intraoperative hypotension (p < .05) and blood pressure lability (p < .01), as well as postoperative nausea (p < .01). Our preliminary results indicate that PVB is feasible and can be performed safely in a patient population with significant comorbidities.

Long-term results of endovascular aneurysm repair with aortouni-iliac custom-made stent grafts.

The purpose of this study was to review the outcome of endovascular abdominal aortic aneurysm repair (EVAR) using custom-made aortouni-iliac (AUI) devices with femorofemoral bypass. Between June 1999 and March 2001, 23 consecutive patients (1 female, 22 male) at high risk of open aortic aneurysm repair underwent EVAR with custom devices in an AUI configuration. The mean follow-up was 37 months (range 2-72 months), and the mean age was 76.8 years (range 67.5-88.7 years). Increased surgical risk was evidenced by 92% and 69% of patients with significant pulmonary or cardiac disease, respectively. The preoperative mean aneurysm diameter (n = 23) 62 +/- 8.2 mm was significantly greater than the postoperative diameter, (n = 23) 54 +/- 16.4 mm. Ten endoleaks occurred. Migration of the stent graft occurred in 9% (n = 2). Secondary interventions were necessary in 23%, whereas tertiary interventions were required in 9%. Patients at high risk of open aneurysm repair received sufficient protection from aneurysm rupture with custom-made AUI devices.

Type A dissection following endovascular thoracic aortic stent-graft repair.

PURPOSE: To describe our experience with endovascular stent-graft repairs in the thoracic aorta focusing on the secondary complication of type A dissection. METHODS: Between January 1996 and April 2004, 73 patients were treated for traumatic thoracic aortic rupture (n=15), type B dissection (n=22), or atherosclerotic descending thoracic aortic aneurysms (TAA, n=36). A retrospective review of the records found 5 (6.8%) patients (3 men; median age 64 years, range 43-87) who experienced a type A dissection at a median 20 days (range 2-124) after thoracic stent-graft repair for 3 type B dissections, 1 TAA, and a late type I endoleak that appeared 28 months after initial stent-graft repair of a traumatic dissection. RESULTS: In 3 patients (2 dissections, 1 endoleak), a tear in the aortic wall at the proximal stent-graft was responsible for a retrograde type A dissection. Underlying disease was the cause of the type A dissection in the 2 other patients (1 dissection, 1 TAA) and was unrelated to the stent-grafts. Three patients underwent open surgery at 3, 26, and 124 days after stent-graft placement; 2 procedures were successful, but the third patient died 3 months later due to multiorgan failure. Two type A dissections were untreated: one patient died from cardiac tamponade 14 days after successful stent-graft exclusion of the type I endoleak; the other patient refused further treatment and survived. The procedure-related mortality following acute retrograde type A dissection was 40%. CONCLUSIONS: Endovascular stent-graft repair of the thoracic aorta is associated with lower morbidity and mortality rates than surgical repair, although potentially lethal complications, acute or delayed, may occur.

Does stent overlap influence the patency rate of aortoiliac kissing stents?

PURPOSE: To determine if the position of kissing stents in the distal aorta has any influence on the patency rate. METHODS: A retrospective review was conducted of 41 patients (22 men; median age 60.8 years, range 44-86) electively treated for atherosclerotic aortoiliac occlusive disease with angioplasty and kissing stents between January 1997 and January 2005. Two patient groups were defined by reviewing postinterventional anteroposterior radiograms: (1) patients in whom the proximal end of the kissing stents overlapped more than half of their angiographic width within the aorta ("crossing" group) and (2) patients in whom the proximal ends of the stents overlapped half of their width or less ("non-crossing" group). RESULTS: At 2 years, the primary and assisted primary patency rates by life-table analysis were 60.8% and 69.4%, respectively, for the 35 patients included in the life-table analysis. There was no significant difference between the 16-patient "crossing" group and the 19-patient "non-crossing" group in terms of the baseline demographic, morphological, and procedural variables. The primary and assisted primary patency rates at 2 years for the "non-crossing" group were significantly higher (94.1% and 100%, respectively) compared to 33.2% and 45.3%, respectively, for the "crossing" group (p=0.01). CONCLUSIONS: Failure of kissing stents in the aortic bifurcation may be significantly increased by the overlap of the free proximal stent ends in the distal aorta.

Use of proximal aortic cuffs as an adjunctive procedure during endovascular aortic aneurysm repair.

The purpose of this study was to evaluate the incidence and durability of additional proximal cuffs during endovascular abdominal aortic aneurysm repair (EVAR). A retrospective review of 90 EVAR patients was conducted. Postoperative survival, proximal sealing zone-related complications, and secondary procedures were analyzed. Additional proximal cuffs were used in 11%. Their use did not affect postoperative survival (p = .58), type I endoleak rate (4.4%; p = .19), or the need for sealing zone-related secondary procedures (6.3%; p = .38) compared with patients without cuff placement but was related to a higher cumulative graft migration rate (2.2% overall p = .02). Two patients (2.5%; p = .79) underwent conversion to open surgery, both for proximal sealing zone-related complications. Application of proximal cuffs appears to be an effective intraoperative adjunctive procedure to achieve a proximal seal during EVAR, with favorable midterm results. However, the risk of late endograft migrations may be elevated in this group.

Does chronic oral anticoagulation with warfarin affect durability of endovascular aortic aneurysm exclusion in a midterm follow-up?

PURPOSE: To evaluate the effect of oral anticoagulation on durability of endovascular aortic aneurysm repair (EVAR). METHODS: Retrospective review was conducted of 182 consecutive EVAR patients (169 men; mean age 75.3 years, range 53-89) between 1999 and 2003. Patients on warfarin anticoagulation (WA, n=21; International Normalized Ratio of 2 to 3) were compared against a control group (CG) with no postoperative anticoagulation (n=161). Death, aneurysm rupture, and reintervention were considered primary endpoints; endoleaks, endograft migration, and aneurysm remodeling were secondary endpoints. RESULTS: Mean follow-up was 16.3+/-12.6 months. One-year mortality was 6.6% (9.5% WA versus 6.2% CG); overall mortality was 14.3% (p=0.414). No aneurysm rupture occurred. At 1, 2, and 3 years, respectively, cumulative reinterventions (20%/20%/20% WA versus 12%/15%/20% CG; p=0.633) and endoleak rates (25%/25%/25% WA versus 17%/22%/34% CG; p=0.649) were comparable. In both groups, most completion endoleaks resolved (42.9% WA versus 74.4% CG; p=0.474), but few de novo endoleaks did (0% WA versus 12.8% CG; p=0.538). Anticoagulation did not affect mean time to aneurysm sac shrinkage (1.3+/-0.3 WA versus 1.4+/-0.1 years CG; p=0.769). CONCLUSIONS: After EVAR, anticoagulation appears safe and does not significantly alter mortality, risk for rupture, or the incidence of reintervention. Early endoleaks appear more common in anticoagulated patients, but anticoagulation does not preclude spontaneous endoleak resolution nor does it increase late endoleak rates. Irrespective of the anticoagulation status, early but not late endoleaks usually sealed spontaneously. Observing type II endoleaks appears safe in the absence of aneurysm enlargement.

High-energy phosphate metabolism in the calf muscle during moderate isotonic exercise under different degrees of cuff compression: a phosphorus 31 magnetic resonance spectroscopy study.

BACKGROUND: The purpose of this study was to investigate phosphocreatine (PCr) and inorganic phosphate levels as well as pH changes in exercising muscle at a workload of 4.5 W under progressive cuff stenoses, whereby the flow reduction due to cuff compression was quantified by flow-sensitive magnetic resonance imaging. METHODS: By using a whole-body 1.5-T magnetic resonance scanner and an exercise bench, serial phosphorus 31 (31P) magnetic resonance spectroscopy with a time resolution of 30 seconds was performed in 10 healthy men. Percentage changes in PCr, inorganic phosphate (Pi), and pH were statistically evaluated in comparison with baseline. The exercise protocol was characterized by a constant workload level of 4.5 W. Ischemic conditions were achieved by a cuff that was placed at the upper leg. Consecutively, increments of 0, 60, 90, 120, and 150 mm Hg were applied. Each increment lasted for 3 minutes. The following rest period was 10 minutes. RESULTS: Blood flow increased significantly immediately after the onset of muscle exercise. No significant changes in blood flow were detected as long as the air pressure of the pneumatic cuff was 60 to 90 mm Hg. Significant reductions in blood flow were observed immediately after inflation of the cuff to 120 and 150 mm Hg. PCr passed into a steady state during the first increment with 0 mm Hg and showed no substantial changes during the increment with 60, 90, and 120 mm Hg. PCr hydrolysis seemed progressive during the 150-mm Hg increment. Pi passed into a plateau level at the onset of exercise and increased significantly at the increment of 150 mm Hg. The pH turned into a steady state with no significant changes during the increments up to 120 mm Hg. At 150 mm Hg, pH decreased progressively. PCr levels at the end of the 150-mm Hg increment correlated significantly and moderately with the reduction in blood flow. CONCLUSIONS: Our study shows that the ischemic condition during constant muscle exercise is clearly characterized by PCr and Pi kinetics, as well as by pH changes. The correlation between the degree of blood flow reduction and PCr levels in the exercising muscle groups, which are supplied by the stenosed arteries, is the first essential of using 31P magnetic resonance spectroscopy in the assessment of the effect of arterial stenoses on muscle function in claudicants.

Polyester vs. bovine pericardial patching during carotid endarterectomy: early neurologic events and incidence of restenosis.

PURPOSE: The aim of this report was to compare polyester vs. bovine pericardial patching during CEA with regards to the incidence of early neurologic events and recurrent stenosis. PATIENTS AND METHODS: One hundred and twenty-five consecutive patients with high grade symptomatic (14%) or asymptomatic (86%) carotid artery stenosis (>70%) who underwent 139 CEAs by a single surgeon between January 1997 and April 2001 were retrospectively reviewed. Patients were assessed postoperatively clinically and with routine follow-up duplex scanning. Recurrent stenosis was defined as a narrowing in the common or internal carotid artery of more than 50% by duplex ultrasound examination. RESULTS: From January 1997 to May 1999, a polyester patch was routinely used in 81 (58%) patients, while between June 1999 and April 2001, a bovine pericardium patch was exclusively used in 59 (42%) patients. There were no ipsilateral postoperative TIAs or strokes in either group. The combined 30-day mortality rate for both groups was 0.8%. One patient in the polyester patch group died from cardiopulmonary complications 10 days after discharge. The length of follow-up in the bovine pericardial patch group was 3-28 months (mean 12 months), while in the polyester patch group was 1-50 months (mean 24.5 month). One patient developed a carotid pseudoaneurysm of the suture line in the bovine pericardium patch group caused by a local infection after previous neck dissection and radiation. The incidence of recurrent stenosis was two patients (4%) in the bovine pericardium group as opposed to six patients (7.6%) in the polyester patch group. CONCLUSION: Although this is a preliminary report, it is concluded that bovine pericardium provides excellent perioperative results and is at least comparable to polyester patching in terms of safety. Our study with short term follow up suggests that bovine pericardium patching during carotid endarterectomy may have a lower restenosis rate compared to knitted polyester patching. Clear superiority of bovine pericardium as a patch material awaits a prospective randomised study with long-term follow-up.

Nontumorous vascular malformations in the liver: color Doppler ultrasonographic findings.

OBJECTIVE: To investigate color Doppler and spectral wave characteristics of nontumorous vascular malformations in the liver. METHODS: From September 1995 to January 2001, 32 cases of vascular malformations were identified by means of color Doppler ultrasonography and spectral wave analysis. Computed tomography, angiography, or both were performed in all cases. RESULTS: Five arterioportal and 14 portovenous malformations, 1 arteriovenous malformation, and 4 portoportal and 8 venovenous shunts were detected. Associations with Rendu-Osler-Weber syndrome in 6 cases and with cirrhotic liver in 12 cases were found Fourteen patients were liver disease free. In 3 cases, interventional procedures were necessary to reduce portal hypertension or cardiac dysfunction. The incidence of finding vascular malformations in 12,000 patients was 0.1%. CONCLUSIONS: Nontumorous vascular malformations are rare disorders in the liver. They may appear in patients with healthy livers and in patients with portal hypertension. Color Doppler ultrasonography and spectral wave analysis are capable of showing and differentiating different types of hepatic vascular malformations.

Serial CT volume and thrombus length measurements after endovascular repair of Stanford type B aortic dissection.

PURPOSE: To evaluate the outcome of stent-graft placement in Stanford type B aortic dissection using contrast-enhanced spiral computed tomographic (CT) measurements of true and false lumen volumes and thrombus length. METHODS: Among 18 consecutive patients (13 men; mean age 60 years, range 44-79) who underwent endovascular repair of Stanford type B dissection, 12 completed at least a 12-month follow-up, which included CT measurements of true and false lumen volumes and thrombus lengths prior to discharge and at 6 and 12 months postimplantation. Volumes were assessed in 3 different aortic segments (A1, A2, A3) extending from the proximal attachment site of the prosthesis to the aortic bifurcation. In addition, thrombus length was measured to evaluate the influence of clot formation on outcome of the false lumen volume. RESULTS: Mean follow-up was 27 months (range 12-60). Within 12 months, mean true lumen volumes showed statistically significant increases in the A1 (p<0.001) and A2 (p=0.003) segments; false lumen volumes showed a significant decrease in the A1 segment (p=0.002) but an insignificant increase in the A2 segment. No substantial volume changes were observed in the A3 segment. Extension of clot formation in the false lumen varied among patients and over time. Length of stent-grafts, percentage of stented dissection length, or visceral arteries originating from the false lumen did not significantly influence thrombus development, nor did these parameters or thrombus formation distal to the prosthesis have a relationship to false lumen volumes. CONCLUSIONS: Volumetric analysis after endovascular repair of Stanford type B dissection shows optimal technical outcome in the stented segment, whereas the false lumen in the segment immediately adjacent to the stent-graft seems to be a vulnerable area. Extension of clot formation beyond the endograft seems to be no reliable predictor of outcome.