How does the Centers for Medicare and Medicaid Services in Baltimore PC evaluate the continued failure rates of stent-graft repair? Why do most practitioners feel that choosing between endovascular repair with endoleaks or EVAR graft migration and open surgical repair is a toss up considering the complexity of EVAR? Is it time for a combination of techniques and a hybrid laparoscopic endovascular procedure with better immediate health outcomes and no reinterventions post procedure?
Minimally invasive surgery is rapidly replacing classical open surgery because the reduced trauma leads to a lower mortality, a quicker recovery and lower costs. Patient preference is also not surprisingly an increasingly important issue. Progress in vascular surgery in particular and other procedures where suturing is required has been slower because of the difficult execution resulting from the current laparoscopic suturing techniques. For this reason there has been considerable interest in trying to develop less exacting anastomotic techniques. Any method intended as a replacement for suturing must be widely applicable, produce equivalent or improved performance and be cost effective.
The completed anastomosis should be smooth, and provide strength and sealing characteristics equal to or better than those provided by sutures. Any technique or device should also produce an anastomosis which is safe and allow easy connection between host tissues and artificial graft materials. An improved clinical result should follow if these objectives can be met with minimal tissue manipulation. If the technique or device also permits more rapid execution than conventional suturing, then there is a significant potential for a significant reduction in surgical morbidity as the duration of aortic clamping is a major cause of mortality and morbidity and has a significant impact on the management of arterial and venous disease.
Since the use of a mechanical device materially shortens aortic occlusion time, this has the potential for lowering complications after a shorter surgical procedure, thereby improving the surgical management of various aortic, arterial and venous diseases. These advantages may result in a significant reduction in the overall surgical morbidity and may well facilitate the move towards total laparoscopic aortic replacement or bypass.
In coronary surgery these devices have radically reduced the time taken to perform an anastomosis and eliminated the need for aortic clamping and cardiopulmonary bypass in CABG (Coronary Aortic By-pass Graft) procedure.
Today, there are 236 (from 43 835 782) international patents and patent applications connected in some way or another with vascular anastomosis. Until now, in spite of numerous filed patents there is no vascular stapler on the market ! This fact illustrates the complexity of the task – development of mechanical vascular anastomotic device permitting easy construction of a safe and durable anastomosis between aorta/artery/vein and synthetic graft, at least as good and safe as a hand-sewn anastomosis…
In 1950s, Androsov1 reported on the use of a circular stapler, developed by Gudov et al., to create an end-to-end vascular anastomosis…
Rygg2,3 in the 1960s introduced the use of staples for prosthetic valve fixation and for closing vascular incisions… In the same decades (’50-’60) Inokuchi4,5 developed a stapler for vascular anastomosis, used in experimental surgery by de Donato et al6. None of these devices gained wide acceptance because of the complexity of their use and the progress made by sutures, which proved to be cheaper, simpler and equally effective.
In 2005 a vascular stapler (“Datascope”) with diameters of 16, 18 and 20 mm was presented to vascular surgeons. This device, defined as a stapling handle, consisted of an anvil, docking pin and handle trigger, positioning wand with guide wire and anti-recoil system. Fixation of the device with the graft inside the aorta is carried out by the application of a loop made of shape memory alloy strip. It is generally agreed that the use of this stapler is very complicated and time consuming… In 2000s, Shifrin and colleagues (ES Vascular Ltd., Israel) developed several types of vascular staplers or open… laparoscopic… and endovascular aortic-arterial-venous surgery, permitting mechanically stapled fast attachment between aorta/ arteries and different synthetic grafts. The aortic stapler device, including the laparoscopic version, consists of two parts, the head and the handle. The head of the stapler contains a 10-clip cartridge with a circular set of clips. The special feature of the clips is that they open on both sides, so that every clip fixes the graft to the aortic wall at two points. Also provided with the stapler are commonly used and approved grafts, which have to be mounted on the stapler, and a specially developed clamp to grip the aorta externally during the stapling process…
In 1992 Kirsch et al.7 introduced the principle of flanged, intimal approximation for microvascular reconstruction by the application of interrupted arcuate-legged, non-penetrating clips… To date, successful clipped anastomoses have been performed clinically in both the peripheral8 and coronary circulation9.
The ease of application of these clips was demostrated with a short learning curve. They provide good conditions for vessel wall healing without excessive inflammation or fibrosis preserving endothelial function and are considerably quicker to use than sutures8-11. The main disadvantage of these clips is their limited usefulness in atherosclerotic vessels, as the vessel wall has to be everted to complete the anastomosis10. They are currently available in various sizes (VCS clips; Auto Suture, Norwalk, CT, USA) and can be used for vessel sizes between 1 mm and 4 mm. To facilitate eversion and to apply the clips circumferentially by a single maneuver, a one-shot anastomotic stapler (One-shot; US Surgical Corporation, Norwalk, CT, USA) has been developed. This device has been tested in animals and human cadaveric tissue for peripheral and coronary applications (proximal and distal vein graft anastomoses), with vessels as small as 1.8 mm in their outer diameter12. In a study on coronary vessel application performed in 14 pigs, Heijmen et al.13 reported six out of 14 imperfect anastomoses because of clip malpositioning with respect to the vessel cut edges, manifestation of early endothelial denudation (2 days), and medial damage in both the coronary and distal internal thoracic artery (ITA), with two local dissections. All anastomoses remained patent at 4 weeks follow-up. An excellent review of Falk14 on proximal anastomotic devices in coronary surgery is currently published. The development of proximal anastomotic devices was triggered by the evolution of Off-Pump CAB (Coronary Aortic By-pass). Since clamping of the aorta was no longer required to induce cardio cardioplegic arrest, the next logical step was to avoid manipulation of the aorta altogether by inserting vein grafts into the ascending aorta without partial clamping, known for its potential risk for atherosclerotic embolization. Most proximal connector designs are based on expandable stents, which connect the graft to the aorta without the need for aortic clamping.
The Symmetry™ Aortic Connector System (St Jude Medical, MN, USA) uses a nitinol stent to connect the vein graft to the aorta… The saphenous vein is placed over a transfer sheet and loaded onto the delivery system, which is selected according to graft diameter. The hooks of the connector penetrate the wall of the proximal (aortic) end of the graft to prevent graft dislocation. After creating an aortal hole using a rotating blade, the actual delivery is performed.
This process can be accomplished in a few seconds. Due to the design of the device, the proximal anastomosis has to be performed first and comes off the aorta in a 90° angle. This design intentionally reproduces the take-off of the native coronary arteries out of the aortic root. The CE Mark and FDA approval were issued in May 2001, and according to the manufacturer more than 80,000 devices have been implanted worldwide. With more widespread use, some conflicting reports concerning patency results were documented in the literature. The FDA also filed reports of early device disconnection. While initially there was great enthusiasm, reports of early graft stenosis and occlusion finally led to the withdrawal of the device from the market.
The PAS-Port System (Cardica Ltd.) is a one-shot device for proximal vein graft anastomosis to the aorta. It can be used for grafts of a diameter ranging from 4 to 6mm… For loading of the graft, the vein is pulled through the stainless steel implant and then manually everted over the end with the help of a poke-through tool; the everted vein is then attached to the implant. The deployment tool is placed on the aorta and the anastomosis is completed by a rotational movement at the end of the device. As with the Symmetry device, the proximal anastomosis has to be performed and the take-off angle is also 90°. Due to its design, there is no direct contact of the device within the bloodstream. The results of a multicenter trial with the first-generation device were quite promising.
The CorLink™ automated aortic anastomotic system (Cardiovations, NJ, USA) is a self-expanding nitinol extraluminal device…The graft is pulled through the inserter and then everted over the distal end of the delivery system. The everted segment of the vein is penetrated by five intimal pins that are deployed from the cartridge of the delivery system. A hole in the aorta is created by a punching instrument that is inserted through the handle of the delivery system. Thus, as opposed to the Symmetry system, this device provides the arteriotomy device and connector in the same delivery mechanism. After the aortic punching device is withdrawn from the handle, the delivery system is advanced into the aorta and the connector is released. The connection is made by partial penetration of the aortic wall by the inner pins, while the outer pins stabilize the graft externally to the aortic adventitia. Only limited data regarding the device are available.
Aptus Endosystems, Inc has number of devices for fixation of endovascular prostheses to arterial wall… By-Pass Ltd has published two PCT applications, Methods and devices for vascular surgery” and “Vascular port devices”. The family of patent analogues for these patents contains about 140 patents. In spite of the “vascular” names of these devices they are intended only for coronary artery connections and do not have aortic applications. An analysis of these patents shows that they relate substantially to the construction of end-to-side anastomoses using a special apparatus for the delivery of mostly autografts, taken from the same patient. The graft is inserted into the axial duct of a special split sleeve (“butterfly” member), flanged at one end on the end of this split sleeve and fixed in this position using a special nitinol fastener. The whole structure is located and secured in the axial cavity of a delivery apparatus (substantially the apparatus designed by Ethicon) which serves for graft delivery to the location of the anastomosis, punching the blood vessel wall at the I anastomotic site and securing it to the opening edges via a nitinol fastener…
The comparative analysis of all these devices with Shifrin’s aortic stapler showed that they are totally different and incompatible with one another. In fact, the By-Pass apparatus itself is used substantially for creating an end-to-side anastomosis. The diameter of the grafts used ranges from 0.8 to 6-8 mm.
The graft is inside and secured to the vessel in an outside to inside direction. In Shifrin’s aortic stapler a graft is placed and secured outside the working head and then in the anastomosis area as well via stainless steel staples. The apparatus is designed to execute an end-to-end anastomosis between aorta and synthetic prosthesis in direction from the graft from inside the vessel. The device diameter ranges from 9 to beyond 22 mm. Thus, in conclusion, the apparatus described above: a) has different, quite specific, applications; b) solves different tasks; c) performs different functions; d) uses novel fastener staples fabricated from stainless steel. All these devices may be regarded as complementing each other in the context of their use in cardiovascular
surgery.As already pointed out, the different anastomotic devices described in this field and available in the patent literature meet some or most but not all the requirements for safe and efficient anastomotic vascular surgery15.
References
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2. Rygg IH, Westengaard E, Fredricksen T. A new method for fixation of prosthetic cardiac valves and closure of atriotomy
with staples. J Cardiovasc Surg 1963; 4: 467-70.
3. Bertelsen S, Rygg IH. A simple stapling device for vascular surgery. Surg Gynecol Obstet 1967; 125: 1087-90.
4. Inokuchi K. A new type of vessel-suturing apparatus. Arch Surg 1958; 77: 954-5.
5. Inokuchi K. Stapling device for end-to-side anastomosis of blood vessels. AMAArch Surg 1961; 82: 337-41.
6. de Donato G, Cecere G, Piscicelli I. The experimental use of Inokuchi’s suturino device in vascular surgery. Min Chir
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10. Leppaniemi A, Rich N, Pikoulis E et al. Sutureless vascular reconstruction with titanium clips. Int Angiol 2000; 19: 69-74.
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12. Nataf P, Hinchliffe P, Manzo S. Facilitated vascular anastomoses: the one shot device. Ann Thorac Surg 1998; 66: 1041-4.
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the beating heart: feasibility in the pig. J Thorac Cardiovasc Surg 1999; 117: 117-25.
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