Jan Brunkwall

Endovascular repair of descending thoracic aortic aneurysms: an early experience with intermediate-term follow-up

PURPOSE The purpose of this study was to report an initial experience with the endovascular repair of descending thoracic aortic aneurysm. Complications and intermediate-term morphologic changes were identified with the intent of altering patient selection and device design. METHODS Endografts were placed into 25 patients at high-risk for conventional surgical repair over a 3(1/2)-year period. Devices were customized on the basis of preoperative imaging information. Follow-up computed tomography scans were obtained at 1, 3, 6, and 12 months and yearly thereafter. Additional interventions occurred in the setting of endoleaks, migration, and aneurysm growth. RESULTS The overall 30-day mortality rate was 20% (12.5% for elective cases; 33% for emergent cases). There were 3 conversions to open repair. Neurologic deficits developed in 3 patients; 1 insult resulted in permanent paraplegia. Neurologic deficits were associated with longer endografts (P =.019). Three endoleaks required treatment, and 1 fatal rupture of the thoracic aneurysm treated occurred 6 months after the initial repair. Migrations were detected in 4 patients. The maximal aneurysm size decreased yearly by 9.15% (P =.01) or by 13.5% (P =.0005) if patients with endoleaks (n = 3 patients) were excluded. Both the proximal and distal neck dilated slightly over the course of follow-up (P =.019 and P =.001, respectively). The length of the proximal neck was a significant predictor of the risk for endoleakage (P =.02). CONCLUSION The treatment of descending thoracic aortic aneurysms with an endovascular approach is feasible and may, in some patients, offer the best means of therapy. Early complications were primarily related to device design and patient selection. All aneurysms without endoleaks decreased in size after treatment. Late complications were associated with changing aneurysm morphologic features and device migration. The morphologic changes remain somewhat unpredictable; however, alterations in device design may result in improved fixation and more durable aneurysm exclusion.

Solitary aneurysms of the iliac arterial system: An estimate of their frequency of occurrence * ** ***

Solitary iliac artery aneurysms are rare, and most reports have been presented as case reports. By combining autopsy records and operating records, a total of 13 cases were found: during a 15-year period (1971 to 1985), 42,010 of the inhabitants of Malmö died (population 230,000) and 35,265 (including 9014 forensic autopsies) underwent autopsy (84%). Solitary iliac artery aneurysms were found in seven (0.03%) of the 26,251 patients who underwent autopsy at the hospital; six of those had been asymptomatic and one was ruptured. Among the 9014 persons who underwent forensic medical autopsy, there were two with ruptured solitary iliac artery aneurysms. Four patients had clinically detected solitary iliac artery aneurysms, three of which were ruptured. All patients underwent surgery, and two of the three patients with ruptured solitary iliac artery aneurysms left the hospital well. The rupture rate of iliac aneurysm among those found at autopsy was one of seven (14%) and among those clinically detected three of four.

Collected world and single center experience with endovascular treatment of ruptured abdominal aortic aneurysms

Background:Case and single center reports have documented the feasibility and suggested the effectiveness of endovascular aneurysm repair (EVAR) of ruptured abdominal aortic aneurysms (RAAAs), but the role and value of such treatment remain controversial. Objective:To clarify these we examined a collected experience with use of EVAR for RAAA treatment from 49 centers. Methods:Data were obtained by questionnaires from these centers, updated from 13 centers committed to EVAR treatment whenever possible and included treatment details from a single center and information on 1037 patients treated by EVAR and 763 patients treated by open repair (OR). Results:Overall 30-day mortality after EVAR in 1037 patients was 21.2%. Centers performing EVAR for RAAAs whenever possible did so in 28% to 79% (mean 49.1%) of their patients, had a 30-day mortality of 19.7% (range: 0%–32%) for 680 EVAR patients and 36.3% (range: 8%–53%) for 763 OR patients (P < 0.0001). Supraceliac aortic balloon control was obtained in 19.1% ± 12.0% (±SD) of 680 EVAR patients. Abdominal compartment syndrome was treated by some form of decompression in 12.2% ± 8.3% (±SD) of these EVAR patients. Conclusion:These results indicate that EVAR has a lower procedural mortality at 30 days than OR in at least some patients and that EVAR is better than OR for treating RAAA patients provided they have favorable anatomy; adequate skills, facilities, and protocols are available; and optimal strategies, techniques, and adjuncts are employed.

Changing aneurysmal morphology after endovascular grafting: relation to leakage or persistent perfusion

PURPOSE To relate changing abdominal aortic aneurysm (AAA) morphology after endovascular grafting to the presence of leakage, collateral perfusion, and other factors. METHODS Thirty-five patients who underwent successful AAA endovascular grafting were evaluated. Self-expanding Z-stents and Dacron grafts were applied in bifurcated and aortomonoiliac systems. Postoperative diameter changes were calculated from repeated spiral computed tomographic scans, angiograms, and ultrasonic phase-locked echo-tracking scans during a median 6-month follow-up (interquartile range [IQR] 3 to 12). RESULTS At 12 months, the diameters of completely excluded aneurysms had decreased 6 mm (IQR 2 to 11; p = 0.006). The proximal graft-anchoring stents had dilated 2 mm (IQR 0.5 to 3.3; p = 0.01). The aortic diameters immediately below the renal arteries but above the stents had not changed. Endoleakage and collateral perfusion (n = 13) were each associated with preserved aneurysm size and a 12 times higher risk of aneurysm dilation. After the leakage or the collateral perfusion had been treated, the aneurysm size decreased. Aneurysms with extensive intraluminal thrombi presented a reduced risk of leakage or perfusion. CONCLUSIONS The diameters of endovascularly excluded AAAs decrease, except in cases of leakage or perfusion. Careful follow-up of patients with aortic endografts is necessary.

Endovascular AAA Exclusion: Will Stents with Hooks and Barbs Prevent Stent-Graft Migration?

PURPOSE To investigate if stents with hooks and barbs will improve stent-graft fixation in the abdominal aorta. METHODS Sixteen- to 24-mm-diameter Dacron grafts were deployed inside cadaveric aortas. The grafts were anchored by stents as in endovascular abdominal aortic aneurysm repair. One hundred thirty-seven stent-graft deployments were carried out with modified self-expanding Z-stents with (A) no hooks and barbs (n = 75), (B) 4 5-mm-long hooks and barbs (n = 39), (C) 8 10-mm-long, strengthened hooks and barbs (n = 19), or (D) hooks only (n = 4). Increasing longitudinal traction was applied to determine the displacement force needed to extract the stent-grafts. The radial force of the stents was measured and correlated to the displacement force. RESULTS The median (interquartile range) displacement force needed to extract grafts anchored by stent A was 2.5 N (2.0 to 3.4), stent B 7.8 N (7.4 to 10.8), and stent C 22.5 N (17.1 to 27.9), p < 0.001. Both hooks and barbs added anchoring strength. During traction, the weaker barbs were distorted or caused intimal tears. The stronger barbs engaged the entire aortic wall. The radial force of the stents had no impact on fixation, while aortic calcification and graft oversizing had marginal effects. CONCLUSIONS Stent barbs and hooks increased the fixation of stent-grafts tenfold, while the radial force of stents had no impact. These data may prove important in future endograft development to prevent stent-graft migration after aneurysm exclusion.

Distal Migration of Stent-Grafts after Endovascular Repair of Abdominal Aortic Aneurysms

PURPOSE To analyze patients after endovascular repair of abdominal aortic aneurysm (AAA) with respect to distal migration of stent-grafts and its underlying causes. MATERIALS AND METHODS Sixty-five patients underwent endovascular repair between January 1994 and February 1997. There were seven women and 58 men, with a mean age of 71 years (range, 51-84 years). Three patients died in the perioperative period (one of myocardial infarction and two of multiorgan failure) and two patients died within 4 months of the procedure of non-procedure-related causes. In addition, two patients were followed at another hospital. The remaining 58 patients were followed up with spiral computed tomography scans at 1, 3, and 6 months, and biannually thereafter. Angiography was performed at 1 month and 1 year after the procedure and additionally when deemed clinically necessary. Mean follow-up was 29 months (range, 1-49). Migration more than 5 mm was considered significant. RESULTS Twenty-six patients (45%) showed distal migration of stent-grafts during follow-up. Mean follow-up time at detection of migration was 13 months (range, 1-36 months). Thirteen cases of migration were ascribed to dilatation of the proximal aneurysmal neck during follow-up. Ten cases of migration were ascribed to causes other than neck dilatation or poor patient selection. In three cases, no obvious cause for the migration was found. The migration was complete in eight cases, leading to late conversion to open surgical repair. On two of these occasions, complete migration lead to aneurysm rupture. In addition, four patients received additional stent-grafts as proximal extensions. CONCLUSIONS Distal migration of stent-grafts after endovascular AAA repair occurred frequently in this series. Dilatation of the proximal aneurysmal neck is a major cause of distal migration of stent-grafts. Improved proximal fixation is needed to secure long-term durability.

Persistent collateral perfusion of abdominal aortic aneurysm after endovascular repair does not lead to progressive change in aneurysm diameter

PURPOSE To differentiate between the phenomenon of collateral perfusion from a side branch versus graft-related endoleaks after endovascular repair of abdominal aortic aneurysms (AAA), with respect to aneurysm size and prognosis. METHODS We successfully treated 64 AAA patients with endovascular grafting. We followed all the patients postoperatively with spiral computed tomography at one, three, six and 12 months, and biannually thereafter. We measured aneurysm diameters preoperatively and postoperatively. We calculated preoperatively the relation of maximum aortic diameter (D) to the thrombus-free lumen diameter (L) expressed as an L/D ratio. Median follow-up was 15 months. RESULTS Sixteen patients had collateral perfusion during follow-up. We successfully treated two patients with embolization. One patient showed resolution of collateral perfusion after we stopped warfarin treatment. Two patients died of unrelated causes during follow-up. One patient was converted to surgical treatment, and two patients showed spontaneous resolution of their collateral perfusion. The group of patients with perfusion showed no statistically significant change of their aortic diameter on follow-up. The group of patients without perfusion showed a median decrease in aortic diameter of 8mm (p < 0.0001) at 18 months postoperatively. The group of patients with perfusion had significantly less thrombus in their aneurysm sac preoperatively than the group without perfusion, as expressed by the L/D ratio (mean L/D 0,61 versus 0,78, respectively; p=0.0021.) CONCLUSION There was no significant increase in aortic diameter on an average 18 months postoperatively despite persistent collateral perfusion. This may indicate a halted disease progression in the short term. Embolization of collateral vessels is associated with risk of paraplegia. We recommend a conservative approach with close observation if aneurysm diameter is stable.

Reduced pulsatile wall motion of abdominal aortic aneurysms after endovascular repair

PURPOSE The reduced size of abdominal aortic aneurysms (AAAs) after endovascular repair suggests lowered intraaneurysmal pressure. In the presence of endoleaks, the size is not decreased. Although postoperative intraaneurysmal pressure is difficult to record, the pulsatile wall motion (PWM) of aneurysms can be measured noninvasively. The aim of this study was to assess the PWM of AAAs before and after endovascular repair and to relate the change in the PWM to aneurysmal size and presence of endoleaks. METHODS Forty-seven patients underwent endovascular repair of an AAA. The aneurysm diameter and PWM were measured with the use of ultrasonic echo-tracking scans preoperatively; at 1, 3, and 6 months; and thereafter biannually. Fifteen aneurysms developed endoleaks, whereas 32 were completely excluded. The leaks were characterized with the use of computed tomographic scanning and angiography. Median follow-up was 12 months (interquartile range, 5 to 24 months). RESULTS The preoperative PWM of the aneurysms was 1.0 mm (range, 0.8 to 1.3 mm). After complete endovascular exclusion, the PWM was 25% (range, 16% to 37%) of the preoperative value (p < 0.001), and aneurysm diameter decreased by 8 mm (range, 6 to 14 mm) (p < 0.001). After 18 months, no further diameter reduction occurred. In three patients without endoleaks but with enlarging aneurysms, the postoperative PWM showed less reduction (p < 0.05). Aneurysms with endoleaks showed no diameter decrease, and the postoperative PWM was 50% higher than that in the totally excluded cases (p < 0.01). In five patients with transient endoleaks, the PWM was reduced after leakage ceased (p < 0.05). Leaks of various sources displayed similar PWM. CONCLUSION The size and PWM of aneurysms are reduced after endovascular repair. The diameter reduction may cease after 1.5 years. Endoleaks are associated with higher PWM than expected. Pressure may be transmitted without evidence of leaks.

Neuropeptide Y stimulates proliferation of human vascular smooth muscle cells: cooperation with noradrenaline and ATP

Since the sympathetic nervous system has been shown to exert a trophic influence on vascular smooth muscle cells (SMC), we studied the growth regulating effects of neuropeptide Y (NPY) in cooperation with the sympathetic co-transmitters noradrenaline and adenosine triphosphate (ATP) in human vascular SMC. NPY stimulated DNA synthesis in human SMC grown from subcutaneous arteries and veins (diameter: 0.4 mm) measured by [3H]thymidine incorporation. Also cell number and protein synthesis were stimulated. The effect was mediated through the Y1-receptor and not Y2 or Y3 since the Y1-selective NPY analogue Pro34-NPY and peptide YY stimulated mitogenesis in the same magnitude as NPY while the NPY-fragment NPY13-36 only had minor effects. The effect was blocked by pretreating the cells with pertussis toxin indicating a Gi/o-coupled effect. The other sympathetic co-transmitters, noradrenaline and ATP, also stimulated mitogenesis in the human SMC in a similar magnitude as NPY. When added together NPY and noradrenaline potentiated each other in the mitogenic response. ATP had mainly additive effects. This is the first demonstration that NPY, noradrenaline and ATP stimulates growth in human vascular SMC. This suggests a role of the sympathetic cotransmitters in modulating vascular tone, but also by inducing hypertrophy/hyperplasia with possible clinical consequences.

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.