Beate Neuhauser

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.

Effect of suprarenal versus infrarenal aortic endograft fixation on renal function and renal artery patency: a comparative study with intermediate follow-up ☆

PURPOSE Suprarenal fixation of aortic endografts appears to be a safe option in patients with a short or conical proximal aortic neck. However, concern persists regarding the long-term effect on renal function when renal artery ostia are crossed by the uncovered stent. We investigated the effect of suprarenal versus infrarenal endograft fixation on renal function and renal artery patency after endovascular aortic aneurysm repair. METHODS Records of 91 patients who underwent endovascular aortic aneurysm repair with a modular bifurcated stent graft between November 1999 and January 2002 were reviewed retrospectively. Two patients receiving dialysis because of chronic renal failure were excluded. Infrarenal fixation was used in 57 patients (group 1), and suprarenal fixation was used in 32 patients (group 2). In two patients in group 1 a Gianturco Z stent was inserted transrenally because of intraoperative proximal type I endoleak, and data for these patients were excluded from analysis. Follow-up evaluation was performed at 1, 6, and 12 months, and yearly thereafter, and included clinical assessment, measurement of serum creatinine concentration (SCr), and computed tomography angiography, per standard protocol. Median follow-up was 12 months (range, 1-36 months). RESULTS There was no statistically significant difference in patient demographic data, aneurysm size, or preoperative risk factors. Median SCr was significantly higher in group 2 (suprarenal fixation) than in group 1 (infrarenal fixation) preoperatively (1.2 mg/dL [range, 0.6-2.3 mg/dL] vs 0.9 mg/dL [range, 0.6-1.9 mg/dL], P =.008) and at 1 month postoperatively (1.1 mg/dL [range, 0.8-5.6 mg/dL] vs 1.0 mg/dL [range, 0.6-2.1 mg/dL], P =.045). There was a significant increase in median SCr in both groups at 1 month postoperatively (group 1, 1.0 mg/dL [range, 0.6-2.1 mg/dL], P =.05; group 2, 1.1 mg/dL [range, 0.8-5.6 mg/dL] [mean SCr, 1.35 mg/dL vs 1.15 mg/dL, respectively], P <.05). In group 1 SCr was increased significantly at 6 and 12 months (P <.001), whereas in group 2 SCr also increased at 6 and 12 months, but not significantly. The change in SCr over time was not significantly different between the two groups. In two of 32 patients in group 2, renal artery occlusion developed, associated with perfusion defects in renal parenchyma and persistently elevated SCr. Analysis of renal artery patency did not demonstrate any association between patency and treatment. No patient developed hypertension during follow-up. CONCLUSIONS Suprarenal endograft fixation does not lead to significant renal dysfunction, and renal artery occlusion is uncommon within 12 months. A larger study with longer follow-up is essential to determine overall effects on renal function and renal artery patency.

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.

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.

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.

Laparoscopic reoperation after failed antireflux surgery.

Introduction: Laparoscopic surgery for the treatment of gastroesophageal reflux disease has been established as being safe, effective, and the best alternative to continuous life-long medical therapy. Antireflux surgery is not, however, devoid of complications and failures. Treatment of these patients represents a major challenge, especially when reoperation is indicated. Patients: One-hundred consecutive patients had a reoperation in our clinic. Previous antireflux procedures were laparoscopic (52 patients), laparotomy (39 patients), and thoracotomy (9 patients). Results: Peri- or postoperative complications occurred in 30 patients (30%). Operative complications were stomach perforation (14), significant bleeding (6), esophageal mucosal perforation (4), gastrocutaneous fistula (2), small bowel enterotomy followed by fistula (1), and tension pneumothorax (1). Reoperation was required in only 2 patients because of a missed stomach perforation or persistent chest leak. The conversion rate (from laparoscopic to open procedure) was 17% overall. Conclusion: Laparoscopic reoperation after a failed antireflux procedure is a major surgical challenge, and it is not devoid of morbidity. The surgeon must have extensive experience in laparoscopic surgery and should be able to perform reoperative open surgery through the abdomen and chest. Laparoscopic redo surgery is feasible with good results. Many patients in whom previous open surgery has failed enjoy the advantages of a laparoscopic redo procedure. Copyright

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.

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.

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.

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.