Autonomic nervous system and genetic effects in hypertension / Endovascular procedures in peripheral arteries
I 662 | Cardiac autonomic dysfunction predicts mortality In left
ventricular hypertrophy
D.R. Wallbridge, S.C. Mclaughlin, S.M. Cobbe, P.W. Macfartane,
A.R. Lorlmer, F.Q. Dunn \ S.D. Pringle 2 . Departments of Cardiology, Royal
Infirmary-, Stobrtill Hospital, Glasgow; NineweBs Hospital, Dundee
Left ventricular hypertrophy (LVH) Is associated with increased cardiovascular
mortality including sudden death, but the precise underlying mechanisms
remain uncertain. Our aim was to Identify parameters predicting mortality
dunng prospective long-term follow-up of 90 hypertensive patients (mean age
57 yre) with ECG LVH and strain.
Methods: Detailed baseline investigation included ecnocarrJography, 24 hour
ambulatory ECG monitoring, thallium sdntJgraphy, and coronary angiography.
Deaths were automatically notified by the Registrar General.
Results: During a mean follow-up of 5.3 years, 31 deaths occurred, of which
19 were cardiac. In univariate analysis, mortality was associated with high
resting heart rate, the absence of betablocker (BB) therapy, reduced heart rate
variability (SDNN), and increased age, but notnon sustained VT. By proportional
hazards analysis, Increasing age and reduced heart rate variability predicted allcause and cardiac mortality; and the absence of betablocker therapy predicted
all-cause mortality (see contour plots). When coronary angiography had been
undertaken (n = 35), significant coronary artery disease was strongly predictive
of subsequent mortality.
Syr nsvlvaj (no BB twapy)
80
1t0
80
100 120 140
SDNN (ITU)
160
In conclusion, impairment of cardiac autonomic function is associated with
increased mortality In hypertensive LVH, and treatment with a betablocker
appears to afford protection.
I 664 I Sympathetic nerve hyperactivfty followed by
hyperinsulinaemia Is the potent determinant factor on
the onset of hypertension
K. Masuo, H. Mikami. T. Oglhara. DepL of Geriatric Medicine, Osaka
University Medical School, Suita, Japan
To evaluate the relations among the onset of hypertension (HT), sympathetic
nerve activity and hyperinsulinemia, we conducted this longitudinal study for 10
yre. Young, non-obese, age- and body mass index (BMI) matched,. Japanese
1064 normotenstve (NT) and 283 borderline hypertensive (BHT) men were
measured BMI, blood pressure (BP), pulse rate, fasting plasma insulin (INS)
and norepinephrtne (NOR), total cholesterol (Teh), and triglyceride (TG) levels
In supine position every year for 10 yrs wtthout any medications (At entry
period: 42 ± 3, 41 ± 2 yre, 22.8 ± 1.2, 22.9 ± 1.0 kg/m 2 , respectively). At
year 10, 43 (4%) NT (NE) and 93 (33%) BHT (BE) developed to established
HT (EHT), and 53 (5%) NT (NB) developed to BHT without BMI Increasing. As
a positive family history of HT (FH+) was defined as at least one parent was
HT, FH+ was recognized In 124 (12%) of NT and 156 (55%) of BHT, and all
of NB, NE and BE had FH+. At entry period, supine NOR in NB, NE and BE
were significantly greater (P < 0.05) than those in NN and BB, who remained
in NT or BHT at year 10, but fasting INS were significantly greater (P < 0.05)
only In BE than BB, not In NB nor NE compared to those In NN (BE > BB >
NE > NB > NN, NOR; 460 > 410 > 400 > 390 > 310 pg/rnl, INS; 17 > 12 >
9 = 9 > 7 fiU/mi). In addition, Teh and TG at entry period did not differ among
5 groups, but those at year 10 were greater in BE > NE > NB > BB > NN
as well as INS. These result demonstrate that sympathetic nerve hyperacttvlty
followed by hyperinsulinemia and positive family history of HT are the potent
determinant factors on the onset or progression of hypertension.
ENDOVASCULAR PROCEDURES IN PERIPHERAL
ARTERIES
670 Renal arterial stenting with the Palmaz stent A 6-year
single-center experience
M. Henry, M. Amor, J.M. Porte, I. Henry, G. Ethevenot, O. Tricoche, B. Mentre
UCCI, Polydlnlque Essey-les-Nancy, France
663
Different behavior of skin and muscle sympathetic
nerve traffic in obese subjects
A. Lanfranchi, G. Seravalle, S. Vaflati, C. Turri, M. Colombo, A. Brunani,
F. Cavagnini, G. Grassl, G. Martcia. Catt di Medidna Intema, Osp. S.
Gerardo, Monza, Univ. of Milan, Centro di Fisiotogia Cllnica e Ipertensione,
Osp. Maggiore; Centro Auxoiogico ttaliano, Milan, Italy
We have recently reported that in obese normotenstve subjects muscle sympathetic nerve traffic Is markedly Increased and that this Increase is accompanied, and possibly caused, by a baroreflex Impairment rt Is unknown, however,
whether the sympathetic activation occurring In obesity is limited to vascular
districts under baroreceptor control or includes vascular areas not regulated by
baroreflex mechanisms. In 12 obese normotenstve subjects (O, age: 39.0 ± 3.1
yre; body mass Index: 37.8 ± 1.1 kg/m 2 , mean ±SEM)and in 10 age-matched
lean controls (C, body mass index: 25.2 ± 1 . 1 kg/m2) we measured mean arterial pressure (MAP, Flnapres), heart rate (HR, EKG), muscle (MSNA) and skin
(SSNA) sympathetic nerve activities (microneurography at a peroneal nerve).
MSNA and SSNA were recorded over a period of 30 mln each, with the subject
supine and resting In a semidark and thermoneutral room. The two recording
periods were separated by a 10 mln interval and the recording sequence was
randomized. SSNA provided an example erf sympathetic nerve traffic modulated
by thermal and emotional but not by baroreflex mechanisms. MAP was similar
in O and in C (98.6 ± 2.6 and 94.7 ± 4.0 mmHg, respectively) and this was the
case also for HR (76.3 ± 3.7 and 72.3 ± 3.2 b/min). As expected, MSNA was
markedly and significantly (p < 0.01) greater in O than C (4Z2 ± 2.8 vs 23.9
± 1.6bs/mln). In contrast, SSNA was similar In O and C (14.4 ± 1.4 vs 16.3 ±
2.2 bs/mln), the ratio of MSNA to SSNA being significantly greater In O than in
C (3.3 ± 0.4 vs 1.8 ± 02 p < 0.01). Furthermore, the SSNA responses to an
arousal stimulus CM not differ between the two groups. These results provide
the first direct evidence that, In contrast to MSNA, SSNA is not enhanced In
obese normotensh/e subjects and that In obesity sympathetic activation is not
generalized. It can be speculated that the MSNA Increase observed in obesity
depends on a baroreflex impairment and Is therefore Dmited to districts under
baroreflex control.
Purpose: To evaluate the role of percutaneous stenting In the treatment of renal
artery lesions after failure of a previous balloon angioplasty.
Materials and Methods. Balloon expandable Palmaz stems were placed
In 85 renal arteries of 77 patients suffering from hypertension resistant to
therapy (77) and renal dysfunction (10) with atheromatous (73) or fibromuscular
(3), or Takayasu (1) diseases, 8 patients had bilateral lesions, 2 a solitary
kidney. Indteations: ostial lesions (49), restenoses (23), unsatisfactory balloon
angioplasty results (28). Mean lesions length: 11.3 cm ± 1.1 (5-20). 11 patients
were treated by Rotabtator9.
Results: Immediate technical success: 100%. Mean lesions diameter after
stenting: 6.25 ± 02 mm 2 major complications, 1 acute thrombosis cured
by fibrtnolysis, 1 arterial rupture requiring surgery. 6 months' angiographic
follow-up performed In all eligible patients (67) showing restenosis In 9 patients
(13.4%) successfully treated by a new angioplasty. Clinical results: systolic
blood pressure (mm/Hg): baseline: 171, post-stent 140, (p < 0.001); dlastolic
blood pressure (mm/Hg): baseline: 93, post-stent 80, (p < 0.001); creatinin
(mg/I): baseline: 14.3, post-stent 15.1, (p: n.s.); BUN (g/1): baseline: 0.48, poststent 0.5, (p: n.s.); number of drugs/patient baseline: 2.7, post-stent 1.3, (p
< 0 02). HTA; cured: 13/67 (19%), Improved: 40/67 (60%), unchanged: 14/67
(21%). Renal dysfunction: improved: 2/10 (20%), unchanged: 8/10 (80%). At 6
years: PI: 69%, Pll: 90%.
Conclusion: Renal artery stenting, is safe and effective, and is an alternative
to surgicalrevascuJartzation,especially in ostial lesions. Our experience shows
a reduction In the restenoses rate, as compared to conventional angioplasty.
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100 120 140
SDNN <ra)
6 yr wnrivd [BB tfMnpy)
113
114
Endovascular procedures in peripheral arteries
I 671 | Laser-assisted recanallzation of pelvic artery
occlusions combined with Implantation of
self-expanding endoprostheses
G. Blamino, J.C. Ragg, D. Sctieinert, J. StaJke. Clinical-lnterventional
Angiotogy, Vlrchow-Klinikum, Humbokft University, Berlin, Germany
Recanalizing long pelvic artery occlusions, additional stent Implantation may
be required. Flexible, fabnc-covered stents could help to achieve a smooth
surface and reduce restenoas within a stented area.
In 70 patients (26 f, 44 m, mean age 62 ± 14 yrs.) with long iliac artery
occlusions (length: 5-18 cm, mean: 9.8 cm) undergoing Exclmer laser assisted
(ELA) recanalization a complementary stent implamatlon was considered necessary (relevant dissections and/or residual stenosis > 50%). In all cases newly
developed self-expanding nltlnol stents, covered by an ultrathln polyester fabric (EndoPro I, MINTEC, EP) were implanted (n =• 78). Evaluation of primary
results and a 6 month follow-up were performed by angtography, Intravascular ultrasound doppler and/or transcutaneous colour-coded ultrasound doppler
(CCUD).
The delivery of EP was successful in 75 of 78 procedures (96.1%). In 68/70
cases (97.1%) the vessel lumen could be nearly normalized by EP implantation
(> 80% of native diameter in the stented area). Using an intravasctrlar doppler
system (FloMap, Cardkxnetrics; 12 MHz, 0.018") regular peak flow velocities
(< 120 cm/s) could be postinterventionally evidenclated within the stented
segments. In 56 patients (80%) there was a rise in body temperature to 38.5
± 0.7 ° C for 1-5 d after Implantation, furthermore signs of Inflammatory
perivascular reaction in CCUD (n = 13) and magnetic tomography imaging (n =
10). Other complications related to EP implantation were not observed. Within 6
months follow-up, reocclusion of the treated segments occurred in 3/70 patients
(4.3%). In 2 cases the vessel could again be recanalized using ELA and local
rt-PA lysis. All other cases (n = 67) were without relevant restenosls according
to CCUD (n = 67), angiography (n = 32) and intravascular doppler (n = 30).
672
Relation between lesion characteristics and vascular
damage after balloon angloplasty assessed with
Intravascular ultrasound
A. van der Lugt, E J . Gussenhoven, G. Pasterkamp, J. Teertstra, J A Tal,
T. Sfjjnen, H. Pieterman. Erasmus University Rotterdam and the ICIN, The
Netherlands
Purpose' to study the Influence of lesion characteristics and balloon size on the
presence of vascular damage after balloon angJoplasty (PTA) of the superficial
femoral artery with Intravascular ultrasound (IVUS).
Methods: 122 patients were studied with IVUS. Ultrasound Images (n =
1019) obtained before PTA with 1 cm interval along the treated segment were
analyzed for lesion topography (concentric versos eccentric),tesJ»oeomposition
(hard versus soft), stenosis versus occlusion and free lumen area (FLA). The
corresponding IVUS images obtained after PTA were analyzed for vascular
damage (dissection, media rupture). Balloon ratio was calculated as balloon
area divided by the FLA seen before PTA.
Results: univariate analysis showed that both lesion topography and baHoon
ratio were signiflcantty related to vascular damage. Concentric lesions, 50%
dissection and 16% media rupture versus eccentric lesions, 42% dissection
and 1 1 % media rupture, respectively. Balloon ratio < 2, 3 1 % dissection and
6% media rupture, balloon ratio > 2, 56% dissection and 17% media rupture,
respectively. Multivariate analysis revealed that stenotic lesion and balloon
ratio were independent variables of dissection and that lesion topography and
balloon ratio were independent variables of media rupture.
Conclusion: balloon ratio is the most important independent variable of
vascular damage seen with IVUS after PTA.
673
Role of transcutaneous echo evaluation of lower limb
artery intra-vascular stents
M. Ctccone, D. Di Noia, O. Rossi, M. Campagna, A. Gagikxie, P. Rizzon.
/nstfftrfe of Cardiology, Ban University, Italy
High definition transcutaneous vascular echography (HOE) is considered the
gold standard In the evaluation of me vascular layers. It is an important tool
in the diagnosis and monitoring of peripheral vascular diseases, hi peripheral
vessels intravascular stents (S) are frequently used in percutaneous transluminal lower limb artery angioplasty procedures. In monitoring Intravascular
stent dysfunction Intravascular-echo is considered the optimal technique, but Is
expensive, Invasive and relativery safe. The aim of this study was to evaluate
the variability and reproducibifity of HDE in the quantitative characterisation of
Intravascular lower limb artery S. 60 pts (56 male, 4 female), mean age 62 ±
7 yrs who underwent percutaneous translumlnal lower limb artery angioptasty
Level
n
A
B
C
Ifiac
Femoral
Popftsal
22
31
14
22 ± 0.5
1.6 ± 0 . 6
1.2 ± 0 . 4
3.7 ± 0.8
2.7 ± 0.9
2.3 ± 0.4
22 ± 0 8
1.6 ± 0.4
1 1 ± 0.4
vartabffity studies:
A
B
C
Intreobserver var
Interobseiver var.
ReproducWity
2 70% r 0.985'
2.95% r 0.981*
2 80% r 0.984*
3.30% r 0.994*
4 53% r 0.996*
3.75% r 0 997*
2.35% r 0.998*
3.94% r 0.996*
3.10% r 0.998*
N=37,*P< 0.001
Conclusions: High definition transcutaneous vascular echography is a useful
tool In the quantitative detection of femoral and popliteal intravascular S.
However, evaluation at the lilac artery level needs further improvement
I 674 | Conservative treatment of latrogenlc vascular
complications from Invasive procedures: techniques
and results
M. Galll, A. PolitJ, S. Zerbonl. Catheterizatlon Laboratory, S. Anna Hospital,
22100 Como, Italy
Background: Vascular complications (VC) dunng cardiovascular catheterizatlon
represent the most common complication of this procedure. Incidence ranges
between 0.6% to 1.6%. Treatment of clinically significant VC has been tradltionaBy surgical. Percutaneous transcatheter techniques as angioplasty and
stent implantation or mechanical compression are alternative non surgical approaches. In this study we have evaluated the usefulness and the applicability
of this conservative approach and devices In the treatment of VC.
Patients and Methods: The study population consisted of 19 patients treated
for VC at our Institution (0.8% of 2270 consecutive cardiovascular catheterizatjons). Demographic, clinical informations and technical details are shown in
the table:
Pz/Sex
Symptoms
4 M, 2 F
Acute rest pain
2 M.1 F
1 M,1 F
2M
1M
3M, 2F
1F
VC
Ocdusrve dissection
lac a.
Ctaudlcatlo
Sub ocdus. dissection
Sac a.
Acute rest pain
OcctusKr. thrombus
femoral a.
Nona
A-V femoralfemoral fistula
Thigh ctaudtation Dissection
succtaviana.
Painful pulsatile
False aneurysm
mass
femomJa.
Painful putsatle
False aneurysm
mass
femoral a.
Treatment
Device
PTA + Stent
Palmaz stent
PTA + Stent
Memotherm stem
Tromboiei + PTA
Endoptotesl
Crag stent
PTA + Stem
Palmaz stent
External
compression
Closure
Feme-stop
Spring cols
Results: immediate technical success was achieved and clinical Improvement
also measured in aU cases. In patients treated with Palmaz stent for tatrogenic
arterial dissection an average of 2.1 stents ware used (most frequent lesion
was longer than 4 cm). In longer dissections we have used Memotherm stent
External mechanical compression (on average 30-40 min) was successful
even in patients receiving continuous anticoagulatton therapy. In 1 case the
A-V fistula was closed with Crag stem, in the second patient, after the failure
of Implantation, a surgical closure was performed. At trie angtographic or echo
doppler control (mean 6 + - 2 months) no artery occlusion or restenosls was
observed. None of 19 pz required further therapy for recurrence of symptoms
on clinical follow-up obtained up to 18 months.
Conclusion: Our e^wrience in the treatment of CV with a conservative
strategy confirms the feasibility of this operative option. The excellent early and
long term clinical and angtographfc results support the efficacy of this technical
approach.
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In conclusion, following laser-assisted recanalization of long pelvic artery
occlusions, the Implantation of EndoPro I is a safe and effective technique
to optimize the results. According to this Initial expenence, the short-term
restenosls rate seems to be low.
procedures and single or muttiple S implantations at the following levels were
studied: Iliac (29), femoral (31), popliteal (14). In all patients we performed
HDE according to the protocol: a) echo-characterisation of intravascular S (hypokinetic, hyperechogenic vascular segment) and echo-color Doppler velocity
flow analysis; b) measurement of the total arterial wall thickness proximal (A)
and distal (C) to S (B). Intra and interobserver variabilities and reproduclbility
were assessed in 37 vascular segments and calculated as the ratio between
standard error of Y estimate and Y mean value percent of A, B and C. Results.
a) complete echo-Ooppler characterisation of intravascular lower limb artery S
was obtained in 76% (22) of the Iliac and 100% of femoral and popliteal S; b)
measurement of the global arterial wall thickness:
Endovascular procedures in peripheral arteries / Vascular remodelling: experimental and clinical studies
115
[ 6 7 5 Percutaneous stenting of abdominal aortic aneurysms
with and without coil Implantation In a swine model
I 6 8 2 | Is geometric remodelling after arterial injury in the
normal rabbit time-dependent?
C.E. Ruiz, H.P. Zhang, A.I. Butt, P. Whfflaker. Lome Unda University Medical
Center, Loma Unda; White Memorial Medical Center, Los Angeles, CA, USA
C. Le Feuvre, O. Tahlll, L Maillard, C. Quettier, L J . Fetdman, P.G. Steg.
Faculty X, Bichat, Paris, France
We surgically created abdominal aortic aneurysms (AAA) using autotogus
fascia in 18 prigs (24 ± 4 kg). The animals were assigned to 3 groups: 9
controls, 5 treated with stent, and 4 wtth a stent and coil combination. The stem
was a self-expandable, uncovered mesh prosthesis. The colls were 5 cm in
length and 5 mm In diameter. We implanted the stent or the stent + coil (1-10
coils) 2-3 days after the initial surgery. Prior to deployment, an aortogram was
performed to ensure the aneurysm size was > 100% of the diameter of the
aorta After deployment, a second aortogram revealed a decreased flow of
contrast into the cavity of the aneurysms. Follow-up aortograms showed either
no evidence of residual aneurysm cavity or markedly decreased size in pigs
who had angtographic follow-up. Importantly, all arterial branches covered by
the stent maintained full patency. Autopsy revealed no aneurysm expansion.
The gross and hlstologic results are shown below:
This study aimed to assess the time course and the relative contribution of
arterial remodeling and Intimal hyperplasia to luminal loss after arterial Injury
In the rabbit lilac Injury was induced by balloon overstretch. Animals were
sacrificed 3 (n = 4), 7 (n = 4), 14 (n = 4), 21 (n = 4) or 28 (n = 8) days
after arterial injury. Lumen, internal (I EL) and external elastic laminae (EEL)
areas were measured using morphometric analysis at the smallest luminal area
from the angioplasty site (S) and the largest luminal area from the adjacent
nonangioplastled segments (R). Vascular remodeling (R IEL - S IEL) and
Intimal hyperplasia (S IEL - S lumen) were normalized by R lumen. This
remodeling Index was stable over time and very variable. Remodeling was
usually negative and responsible for 67 ± 93% of the lumen area stenosis
(100% at day 3 following injury, 69% at day 28). Remodeling was negatively
related to the index of Intimal hyperplasia (r = 0.72, p < 0.0001) and positively
related to the lumen area stenosis (r = 0.96, p < 0.0001).
Plg#
Device
F/U
Gross and histo4oglc findings of AAA
1
2
3
4
5
6
7
8
9
stent
stent
stem
stent
stent
stent-I-cot
•tent + col
stent -t-cofl
stent+ coH
8 days
4wks
6wks
3 mos
6moe
12hre
4wks
3 mos
6 mos
njpture, no evidence of new coQagen production
thick wail, organized thrombus, no new cotagen
thick wall, new immature colagen
thin Immature coflagen
thick wal with thick, mature aligned colagen
(died from anesthesia complcatkxi)
thick mature aligned collagen
thick wall with highly algned mature collagen
AAA non-existent, replaced by flbrosts
VASCULAR REMODELLING: EXPERIMENTAL AND
CLINICAL STUDIES
681
Extracellular matrix: a target for remodelling associated
with restenosls after experimental angioplasty in New
Zealand white rabbits
Antolne Lafont Fredrick Cornhill, Eric Durand, Carlos Morelra,
Franpoise Vilde, Michel Desnos, Claude Guerot Faculty Necker, Paris,
France; The Cleveland Clinic Foundation, Cleveland, OH, USA
We and others have shown that post-angioplasty restenosis is more related
to constrictJve remodeling than neolntimal hyperplasia. We therefore examined
the alteration of extracellular matrix (ECM) associated with restenosis after
experimental angioplasty In rabbits.
Lesions were induced by air-drying and cholesterol-supplemented diet. Four
weeks later, angioplasty was performed. Angtographic, histdogic, and morphometrtc evaluation were conducted 4 weeks after angioplasty. The difference
between the Intima + media area of the reference and lesion srtes normalized
by the corresponding area at the reference site offered an index of hyperpiasia
The hlstologic extent of late residual stenosis was defined as the difference
between the lumen areas of reference and lesion sites normalized by the lumen
area of the reference site. ECM density was quantified by a color computerized
program in the intima, media, and adventitla. Initial gain in the minimum lumlnal
anglographic diameter (MLD) was 0.51 ± 0.29 mm after angioplasty. Loss In
MLD by 4 weeks was 0.90 ± 0.56 mm. Hypeiptasia did not correlate with
restenosis. ECM density correlated at the lesion site wfth the extent of late
residual stenosis in the neofntima (r = 0.49; p = 0.04) and especially media
(r = 0.60; p = 0.005), but not adventWa (r = 0.19; p = 0.45). ECM density (fid
not correlate wfth the Index of hyperplasia at the three layers. Nor dkj ECM
density correlate with both hyperplasia and residual stenosis In non dilated
atherosclerotic lesions.
Restenotic lesions are thus associated with an increased distribution of ECM
in the neointima and especially the media in this model. ECM remodeling
represents a new target for restenosis.
I 6 8 3 I Redox processes markedly affect early vascular
remodelling after Injury In rabbits: evidence for distinct
sequential mediators of the remodelling process
Francisco R.M. Laurindo, Peter C Tufolo, Marcel Uberman,
Mariano Janlszewski, Protasio L da Luz. Heart Institute, University of SSo
Paulo, Brazil
To assess the role of redox processes in vascular remodeling after angioplasty,
sequential changes in arteriographlc caliber were analyzed at 7 and 28 days
after balloon injury of right iliac arteries in intact control rabbits (n = 11) and in
those given the anttoxkJants N-acetylcysteme (NAC, 220 mg/kg/day, n = 9) or
allopurinol (ALO, 25 mg/kg/day, n = 9) for the 28-day period. In this model, at
7 days after injury, there is negligible intimal thickening, so that fixed vascular
lumen (VL) changes reflect remodeling. In controls, balloon Inflation Induced 42
± 4 [SE]% VL distenuon; by day 7, VL cafiber was reduced to 16 ± 4% above
contralateral normal artery and was unchanged by acetytcholine or isosorbide
mononitrate. In contrast, after similar balloon injury, such VL loss at day 7 was
totally prevented by NAC or ALO, wtth respective VL calibers of 56 ± 6 and 40 ±
6% above normal (p < 0.0005 vs. control). These data suggest that, earty after
balloon Injury, there is a significant loss in caliber mediated by redox-dependent
vascular remodeling. The anticoddant effect however, had a poor final impact
on the 28Ol-day arteriogram, which showed similar, vasodilator-insensitive, VL
calibers with NAC or ALO vs. controls (respectively 20 ± 3, 31 ± 4 a n d 3 3 ±
3% below normal, p = NS). Thus, VL loss between days 7 and 28 was 1.5-fold
greater with NAC and ALO (p < 0.01 vs. control). This accentuated VL loss
was unaffected by drug withdrawal at day 7, as assessed In other rabbits. Also,
such VL toss was not explained by increase of the neointlma (which grows
between days 7 and 28), since neolntimal thickening was similar among groups
(on average 5 1 % of wall area) and did not correlate wtth Individual VL toss;
this Is consistent wtth an eflect of increased remodeling between days 7 and
28. Thus, the early VL-preserving effect of antioxIdantB was later buffered by
enhanced free radical-independent remodeSng. These data are consistent with
different sequential mediators of the remodeling process.
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In pigs treated with stent alone, mature collagen was not seen until 6 months.
In contrast, mature collagen was seen much earlier In coil treated aneurysms.
All 9 controls died after surgery (3-43 days) and 7 died from rupture versus only
one In treated pigs (p = 0.02). We conclude that the uncovered stent and stentcoil placement may effectivety prevent aneurysm rupture, while maintaining
arterial patency. The aneurysm lumen was gradually replaced by collagen and
we speculate that this healing process was enhanced by the addition of coils.
Conclusion: In this model, luminal loss is mostly due to artenal remodeling
rather than intimal hyperplasia. The importance of remodeling is not related
to the delay following arterial Injury, and is very variable. There is an inverse
relationship between constrictive remodeling and intimal hyperplasia.