A balloon-expandable intravascular stent for obliterating experimental aortic dissection

doi:10.1016/0741-5214(90)90218-Y

Journal of Vascular Surgery

Volume 11, Issue 5, May 1990, Pages 707-717

Presented at the Forty-third Annual Meeting of the Society for Vascular Surgery, New York, N.Y., June 20-21, 1989.

https://doi.org/10.1016/0741-5214(90)90218-Y Get rights and content

Abstract

Acute aortic dissection is a life-threatening condition. Aggressive hypotensive drug therapy is the initial treatment of choice, although emergent surgical intervention is often warranted. We evaluated the efficacy of a balloon-expandable intravascular stent for the internal obliteration of aortic dissection. It is a flexible, continuous, complex coil cut to the length needed at the time of insertion. It can be positioned in curved vessels, including the aortic arch. The stent was inserted in the thoracic and abdominal aorta of 12 dogs (group I). Six weeks after implantation the dogs underwent angiography and the stents were explanted for light and scanning electron microscopy. There were no instances of stent migration or change in configuration. The aortas did not rupture. All branch vessels remained patent. Light and scanning electron microscopy illustrated neointimal incorporation into the vascular wall except at orifices. Thoracic dissections were created surgically in an additional 24 mongrel dogs. Twelve dogs received stents immediately after creation of the dissection (group II). All 12 dissections were obliterated. Twelve dogs were allowed to recover after creation of the dissection to observe the natural history of that lesion (group III). Within 1 week, in group III, there were three deaths because of aortic rupture; eight dissections persisted, and one resealed spontaneously. Stents were placed in the eight persistent dissections. All eight dissections were obliterated. In both groups, after 6 weeks of stent placement, aortography was repeated, and stents were explanted for light and scanning electron microscopy. There were no instances of rupture. All branch vessels remained patent with no evidence of thrombosis. We conclude that because of its unique characteristics, the stent effectively obliterates the false lumen of experimental acute aortic dissections without occluding side branches, damaging the aorta, or inducing thrombosis. (J VASC SURG 1990;11:707-17.)

Section snippets

Material and methods

The stent is a preformed sinusoidal-shaped, stainless-steel, type 316L-0.011 inch (0.279 mm), wire wound into an open-ended helix Medtronic-Wiktor Balloon-Expandable Stent (Medtronic, Minneapolis, Minn.) Once the required length of stent is determined the desired amount is cut from a longer piece and crimped manually onto the low profile balloon of the catheter (Meadox-Surgimed, Inc. [Olbert balloon catheter] Oakland, N.J.). When the stent is longer than the balloon, its trailing portion is

Biocompatibility

No technical problems were encountered with the implant technique in group I. After operation and during the 6-week observation period all animals remained clinically healthy. In all cases preexplant aortograms revealed no stent migration, aortic perforation, thrombosis, or branch occlusion. On gross inspection all aortic branch orifices were patent. The stent was incorporated into the vascular wall with each portion of the coil covered by intima, except at orifices (Fig. 4).

. Photomicrograph

Discussion

In 1969 Dotter¹⁵ first introduced the technique for the nonoperative placement of a tubular, coiled nitinol wire stent. Since then several self and balloon expandable stents have been introduced, all with the intent of maintaining luminal patency, usually in conjunction with balloon angioplasty.16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 Previous stents have been limited in length, diameter and their ability to accommodate curves. In an attempt to stent long or curved vascular

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Cited by (61)

Endograft exclusion of the false lumen restores local hemodynamics in a model of type B aortic dissection
2020, Journal of Vascular Surgery
Endovascular intervention in uncomplicated type B dissection has not been shown conclusively to confer benefit on patients. The hemodynamic effect of primary entry tear coverage is not known. Endovascular stent grafts were deployed in a model of aortic dissection with multiple fenestrations to study these effects. It is hypothesized that endograft deployment will lead to restoration of parabolic true lumen flow as well as elimination of false lumen flow and transluminal jets and vortices locally while maintaining distal false lumen canalization.
Thoracic stent grafts were placed in silicone models of aortic dissection with a compliant and mobile intimal flap and installed in a flow loop. Pulsatile fluid flow was established with a custom positive displacement pump, and the models were imaged by four-dimensional flow magnetic resonance imaging. Full flow fields were acquired in the models, and velocities were extracted to calculate flow rates, reverse flow indices, and oscillatory shear index, the last two of which are measures of stagnant and disturbed flows.
Complete obliteration of the false lumen was achieved in grafted aorta, with normal parabolic flow profiles in the true lumen (maximal velocity, 30.4 ± 8.4 cm/s). A blind false lumen pouch was created distal to this with low-velocity (5.8 ± 2.7 cm/s) and highly reversed (27.9% ± 13.9% reverse flow index) flows. In distal free false lumen segments, flows were comparable to ungrafted conditions with maximal velocities on the order of 7.0 ± 2.1 cm/s. Visualization studies revealed forward flow in these regions with left-handed vortices from true to false lumen. Shear calculations in free false lumen regions demonstrated reduced oscillatory shear index.
Per the initial hypothesis, endovascular grafting improved true lumen hemodynamics in the grafted region. Just distally, a prothrombotic flow regimen was noted in the false lumen, yet free false lumen distal to this remained canalized. Clinically, this suggests a need for advancing endovascular intervention beyond sole entry tear coverage to prevent further false lumen canalization through uncovered fenestrations.
An experimental model of Stanford type B aortic dissection with intravenous epinephrine injection
2013, Kaohsiung Journal of Medical Sciences
Citation Excerpt :
Thus, the true lumen was compressed by a stitch at the level of the tear. Most subsequent experimental models of AD have been modifications of this method [12–14]. Angouras et al. reported a different method for AD development in pigs that involved destroying the adventitia of the descending aorta to promote differential blood supply to the inner and outer layers of the media.
The aim of this study was to create an experimental model of aortic dissection (AD) with a long-term patent false lumen to develop new treatments for Stanford type B aortic dissection. Sixteen adult beagle dogs (weight 14–18 kg) were used. After exposure and partially clamping, the descending aorta was cut through the adventitia to one-third of the depth of the tunica media. The aortic wall was divided into two layers by raspatory. Then half the circumference of the inner layer was cut transversely. All of the proximal layers and the distal outer layers were anastomosed together. Epinephrine was immediately used to expand the false lumen, and the effect was terminated using nitroglycerin when necessary. All dogs underwent both digital subtraction angiography (DSA) and computed tomography angiography (CTA) immediately after and 1 week and 1 month after surgery. The dogs were followed up at 1 day, 3 months, 1 year, and 2 years. The surgery was successful in 12 dogs. Dissection formation was observed immediately after epinephrine administration and confirmed by DSA and CTA. Our results showed typical characteristics of AD, such as a tear, septum, and true and false lumens. This is an easy and feasible way of developing a Stanford type B AD model by intravenous injection of epinephrine. In this canine model of AD, the false lumen has excellent long-term patency and the dissection plane is histologically similar to that in human AD. This model may contribute to the development of new treatments for Stanford type B AD.
Two-End Intimal Flap Suturing Method for Establishing Stanford B Type Aortic Dissection in a Canine Model
2009, European Journal of Vascular and Endovascular Surgery
Citation Excerpt :
Although some animals developed spontaneous re-entry, this method did not create a stable false lumen with both entry and re-entry of blood. Other investigators have tried to create a pocket or separation in the aortic wall by simple balloon expansion3 or direct saline injection.4 These models were limited by the fact that the false lumen was relatively narrow and short.
To establish an animal model of Stanford type B aortic dissection using a two-end intimal flap suturing.
Twelve adult mongrel dogs of either sex were studied and followed up, at intervals, up to 1 year.
A lateral clamp was placed on the proximal descending aorta after general anaesthesia and left thoracotomy. Half the circumference of the aorta, including the media and adventitia, was cut open transversely, leaving the intima intact. The aortic wall was separated inferiorly. The intima was transversely cut and both ends of the distal intimal flap were sutured to the adjacent aorta. To close, the distal adventitia and media were sutured to the proximal aorta. Before thoracic cavity closure, digital subtraction angiography (DSA) and colour Doppler ultrasound were performed.
Formation and distal extension was observed immediately after removal of the partial aortic clamp in 11 dogs. True and false lumens were seen in eight dogs; the false lumen was larger than the true lumen. Sacrifice at set intervals, 7 days to 12 months after surgery, showed a typical dissection tear, intima, septum, adventitia, thrombi and distal dissection blind pocket.
This model of aortic dissection using the two-end aortic intimal flap suturing method is similar to human Stanford type B aortic dissection.
Type A aortic dissection: New surgical strategy using intra-operative stenting
2006, Journal of Thoracic and Cardiovascular Surgery
Rich's Historic Collection of Vascular References
2004, Vascular Trauma: Second Edition
Aortic dissections: New perspectives and treatment paradigms
2003, European Journal of Vascular and Endovascular Surgery
Aortic dissection is a complex manifestation of disease of the arterial wall. The severity and consequences of a dissection are related to the physical characteristics and anatomic location of the tear as well as the underlying patient physiology. Despite in vitro and in vivo modeling advances, our understanding of the pathophysiology has been limited to evaluations of the success and failure of various treatment modalities. The indications for intervention have historically included rupture, intractable pain or hypertension, distal ischemia and degeneration of the aortic wall causing aneurysm formation.
The management decisions for patients with dissections are dependent upon the abnormal anatomy, the acuity of the patient presentation, and physiology. Despite the availability of open surgery as a therapeutic option, acute dissections with evidence of ischemia are now handled using an endovascular approach that is specifically directed at the cause of the ischemia. Endovascular treatments include the placement of a stentgraft into the proximal aorta, branch vessel stenting, uncovered stent placement in the abdominal aorta, and aortic fenestrations. Chronic dissections, in contrast, are still most frequently managed with open surgical techniques. However, a subset of patients that are not candidates for traditional surgical repair of the thoracoabdominal aorta may be managed with a combined open mesenteric revascularization with subsequent endovascular grafting of the thoracoabdominal aorta.

View all citing articles on Scopus

^*: Reprint requests: Victor Parsonnet, MD, Department of Surgery, Newark Beth Israel Medical Center, 201 Lyons Ave., Newark, NJ 07112.

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Original Article from the Society for Vascular SurgeryA balloon-expandable intravascular stent for obliterating experimental aortic dissection*

Abstract

Section snippets

Material and methods

Biocompatibility

Discussion

Am Heart J

J Thorac Cardiovasc Surg

Prog Cardiovasc Dis

Am Heart J

J Thorac Cardiovasc Surg

J Thorac Cardiovasc Surg

Ann Thorac Surg

J Vasc Surg

J Am Coll Cardiol

Dissection and dissecting aneurysms of the aorta: twenty-year follow-up of 527 patients treated surgically

Surgery

Aneurysms of the aorta

Hosp Prac

Dissecting aneurysm of the aorta. Diagnosis and operative relief of acute arterial obstruction due to this cause

NY State J Med

Surgical considerations of dissecting aneurysm of the aorta

Ann Surg

A method for repair of aortic dissection originating in the transverse arch using two sutureless intraluminal prostheses

Arch Surg

Endovascular stent for use in aortic dissection: an in vitro experiment

Radiology

Transluminally placed cloistering endarterial tube grafts: long-term patency in canine popliteal artery

Invest Radiol

Transluminal expandable nitinol coil stent grafting: preliminary report

Radiology

Nonsurgical placement of arterial endoprosthesis: a new technique using nitinol wire

Radiology

Original Article from the Society for Vascular Surgery
A balloon-expandable intravascular stent for obliterating experimental aortic dissection*