MMCTS
(September 7, 2009). doi:10.1510/mmcts.2008.003780
Copyright © 2009 European Association for Cardio-thoracic Surgery
Procedure
Endoscopic radial artery harvesting
Gianluigi Bisleri*,1 and
Claudio Muneretto
Division of Cardiac Surgery, University of Brescia Medical School, Italy
* Corresponding author: Gianluigi Bisleri, Cardiochirurgia SSVD, Spedali Civili, P.le Spedali Civili, 1, 25123 Brescia, Italy. Tel.: +39-030-3996401; fax: +39-030-3996096. gianluigi.bisleri{at}gmail.com
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Summary
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As novel technologies became available in the surgical scenario, there has been an increasing interest towards minimally invasive approaches for conduits harvesting in recent years. There is a consistent evidence in literature demonstrating the advantages of an endoscopic approach for saphenous vein harvesting over the open technique; therefore, several authors previously investigated and demonstrated the safety and usefulness also of an endoscopic approach for radial artery harvesting when compared to the open one. This article describes the currently available approaches for minimally invasive endoscopic radial artery harvesting (ERAH) and focuses on the authors' experience combining a reusable retractor and a disposable vessel sealing systems.
Key Words: Endoscopic • Radial artery • Minimally invasive
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Background
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The conventional (open) approach for radial artery (RA) harvesting has been extensively adopted in clinical practice [1]. Utilizing such approach, a 18–20 cm curved incision is performed along the forearm (Schematic 1). During harvesting, a gentle retraction of the brachioradialis muscle is usually performed in order to further enhance vessel exposure (Schematic 2). However, two nerves could be inadvertently injured and, therefore, must be protected during RA dissection (Schematic 3): first, the lateral antebrachial cutaneous nerve (causing paresthesias and numbness of the radial aspect of the volar forearm); then, the superficial branch of the radial nerve (resulting in paresthesias and numbness of the thumb and the dorsum of the hand).
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Endoscopic radial artery harvesting (ERAH): surgical approach
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ERAH has only recently been introduced in the clinical scenario, whilst endoscopic removal of the great saphenous vein is a well-established technique during coronary artery bypass surgery and proved to offer significant advantages in terms of wound complications, reduced pain and aesthetics, while yielding remarkable results with respect to the histological analysis of the harvested conduits [2]. Therefore, a vivid interest for ERAH was developed in order to obtain the same clinical benefits as in endoscopic vein harvesting (EVH), thanks also to the advances in tools for endoscopic visualization of the conduits and vessel sealing systems in order to complete harvesting. The preoperative evaluation criteria (e.g. negative Allen test, choice of non-dominant arm, etc.) previously described for the open approach are similarly adopted for the endoscopic technique.
Patient selection
ERAH can be virtually performed in all patients scheduled for CABG surgery and in those who the use of the radial artery is planned. Nevertheless, a careful selection of such candidates is strongly recommended during the initial phase (i.e. at the beginning of the learning curve) of the ERAH program, in order to avoid unnecessary discouragement and frustration of those surgeons involved in the endoscopic approach. In particular, it is advisable to avoid patients with over-developed muscular or fat forearm at the beginning, unless the surgeon has already a consistent background in endoscopic procedures (preferably in EVH). Once the surgeon has completed the learning curve (usually 20 cases are the average in order to reach the ‘plateau’ phase), more heterogeneous patients could be included in the ERAH program.
Surgical equipment
There are two different approaches currently available on the market for ERAH, i.e. sealed and open systems.
Sealed systems (Vasoview System, Maquet Cardiovascular) utilize carbon dioxide (CO2) insufflation at a target pressure in order to achieve endoscopic view; a blunt dissector and a multipurpose device are used to achieve ERAH. Conversely, the open systems (Karl Storz, Germany and Sorin Group, Italy) utilize a retractor for endoscopic exposure of the conduit along with a disposable device for tissue sealing and side branches division; in such cases, CO2 may be optionally used uniquely as visual flush, but no positive pressure is created inside the forearm.
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Surgical technique
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ERAH with open systems
A schematic overview of the OR setting during endoscopic harvesting of the radial artery is depicted below (Schematic 4). The upper extremity (usually the non-dominant arm) is prepped, draped and placed on an arm board perpendicular to the long axis of the operating table. The arm needs to be secured to the arm board (e.g. using adhesive tapes or towel clips) in order to provide an adequate setting for ERAH, especially in the initial steps. Moreover, a rolled pad below the wrist (allowing extension of the hand) is fundamental to achieve a proper positioning of the forearm during ERAH, otherwise it will be extremely cumbersome to maneuver the endoscopic retractor and the vessel sealing system during the procedure (Video 1). Worthy of note, regardless of the manufacturer, no tourniquet around the arm is used with such technique: in fact, the pulsation of the radial artery can represent an important landmark especially in difficult cases, when a clear and direct visualization of the radial artery cannot be achieved.
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Schematic 4 The surgeon harvesting the radial artery stands at the level of the hand, facing the arm in front of him and the monitor on the other side of the table (behind the other surgeon harvesting the LIMA for example).
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Video 1 The arm is placed on an arm board with an angle perpendicular to the operating table. A rolled pad is placed beneath the wrist to improve exposure in the distal end, then the arm is secured to the board using adhesive tapes and towel clips.
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As previously described [3, 4], the very first step of ERAH is the exposure of the radial artery through an incision in the distal side, at the level of the wrist (Schematic 5): this part yields an essential role in preparation for the following ‘endoscopic’ phase; therefore, the operating surgeon should perform this step carefully in order to allow a simpler endoscopic step afterwards. A 2- to 2.5-cm longitudinal incision of the volar surface of the forearm is performed beginning 1 cm proximal to the radial styloid prominence (Video 2); the subcutaneous tissues first, then the fascia between the brachioradialis and the flexor carpi muscles is then divided and the radial artery is identified. Care is taken to separate the radial artery from the superficial radial nerve, which is the only one of the two nerves that can be damaged during radial artery harvest. In fact, the endoscopic approach avoids the risk of damage to the lateral antebrachial cutaneous nerve, thereby reducing the incidence of postoperative neurological complications.
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Video 2 The radial artery is visualized through the mini-incision.
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The dissection of the radial artery as a pedicled graft from the surrounding tissues is then started with the vessel sealing system under direct vision. Such dissection should be extended proximally as much as possible (i.e. 2–3 cm) under direct vision by lifting the self-staying retractor, otherwise the dissection of the distal part of the radial could become extremely cumbersome should the endoscopic instruments not have been advanced in the forearm for at least 3–4 cm (Video 3).
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Video 3 A careful dissection of the radial artery from the surrounding structures is performed by means of the vessel sealing system.
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As previously reported [3, 4], endoscopic harvesting is achieved by opening the fascia above the radial artery for a few centimeters, then dividing the side branches; the sequence is repeated until the radial artery has been harvested along its entire length. At any stage, an inadvertent injury of a side branch may occur. In most of such instances, the injury is minor albeit the endoscopic view may magnify the entity of bleeding. It is therefore recommended to pull out the endoscopic retractor and the vessel sealing system from the forearm and to perform compression from the outside. After a few minutes, bleeding usually resolves spontaneously; nevertheless, in those instances, once the radial artery is outside the forearm, it should be assessed in order to rule out potentially leaking side-branches.
Once harvesting is completed, a pigtail vessel dissector (‘hook’) is used to verify absence of residual side branches. Finally, a second counterincision near the antecubital fossa can be performed in order to retrieve the radial artery; otherwise, a single incision can be utilized and the radial artery can be endoscopically divided with a clip or an endo-loop.
ERAH with sealed systems
Arm positioning is similar to the open systems, albeit the main difference is represented by a tourniquet placed at the elbow, in order to completely exsanguinate the forearm. Such a maneuver can jeopardize visualization of the radial artery during endoscopic harvesting especially in difficult cases, however, it is recommended when such technique is used.
The radial artery is then exposed and dissected free under direct vision as previously described [5]. A blunt tip trocar is placed at the level of the wrist incision and its balloon inflated to the minimum amount necessary to establish an appropriate seal. CO2 insufflation is started in order to pressurize the tunnel to approximately 15 mmHg, similarly to EVH. Continuous expired pCO2 monitoring is recommended as with established EVH. An anterior and posterior exposure around the radial artery pedicle is obtained by careful dissection with the blunt dissector. Then, the VasoView Harvesting Cannula Seal with the bipolar scissors or bisector is inserted into the predissected tunnel. Therefore, branch division is achieved similarly to EVH. Confirmation of complete branch division by lengthwise passage of the vessel cradle is carried out. Finally, under endoscopic vision, proximal ligation of the radial artery is performed using an endo-loop at proximal end and division by means of the endoscopic scissors.
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Clinical experience
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Similarly to what has previously been described [3, 4, 6], we utilized an open system of ERAH. Nevertheless, we adopted a newly designed endoscopic retractor that can be combined with different types of disposable vessel sealing systems, according to the surgeon's preference. Moreover, we used a slight technical modification of the previously described technique for ERAH in order to further enhance the feasibility of the technique, even in complex cases. Three instruments are used for completion of ERAH: an endoscopic retractor, a vessel sealing system, a vessel pigtail retractor.
The system used for endoscopic view is an endoscopic radial artery retractor (Bisleri Model – Karl Storz, Tuttlingen, Germany) which is a stainless steel, reusable device with a 45° endoscope. Unlike other systems currently available on the market, this tool is specifically designed for endoscopic harvesting of the radial artery and its main features include improbe front and rear profile (Photo 1A, B), smoke evacuation channel (Photo 2) and a peculiar tunnel-like design (Photo 3). Such tunnel-like structure is particularly useful in patients with overdeveloped (either fatty or muscular) forearm, since it prevents tissue from surrounding structures to get into the operative field.
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Photo 1 The radial artery retractor presents a modified front (A) and rear (B) design for improved exposure in the forearm.
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The choice of the most appropriate vessel sealing system relies on each surgeon's preferences, and as such, it is not a matter of debate in the present article. To date, the reusable endoscopic radial artery retractor has been safely and effectively used along with the following devices:- RoBi forceps and Metzenbaum scissors (Karl Storz, Germany): this device uses a conventional bipolar radiofrequency energy source.
- Enseal endoscopic forceps (SurgRx, USA and ERBE, Germany): it is a bipolar radiofrequency device with a peculiar structure in the jaws, thanks to millions of nanometer-sized conductive particles embedded in temperature-sensitive material and each particle acts like a discrete thermostatic switch. Sealing is achieved through compression, protein denaturation and renaturalization; finally, a cutting blade allows a fast and effective division of the tissue.
- Starion endoscopic forceps (Starion Instruments, USA): this device has a heating element at the tip, and thanks also to high compression jaws it allows an effective sealing and division of tissues through a ‘thermal-welding’ process.
- Harmonic scalpel/Ultracision (Ethicon Endosurgery, USA): this device uses ultrasonic energy for sealing and division of tissues. Despite its widespread use, this device has weak compression force in the jaws and, therefore, often a degree of traction in order to achieve tissutal division is required.
Once division of the side branches and tissues has been completed, the absence of any residual side branches is confirmed by means of a reusable ‘hook’ artery retractor (Karl Storz, Tuttlingen, Germany).
Despite other authors who previously described the approach for ERAH, we adopted slight modifications in order to further enhance the technique. Following exposure of the radial artery under direct vision and careful division from surrounding structures, the fascia between the brachioradialis and the flexor carpi muscles is endoscopically divided up to the antecubital fossa (Video 4). We believe it is important to maintain a dissection plane just over the fascia and not to divide any muscular structure (in particular the brachioradialis muscle) in an attempt to improve the visualization of the radial, as proposed by other authors [7]. In fact, even in difficult cases, the reusable retractor we use can be advanced below the muscular structures and the ‘tunnel-like’ design allows performing ERAH with enough comfort for the surgeon, avoiding any unnecessary damage to the muscular structures. It is then extremely useful in our experience to begin the dissection of the radial artery on the brachioradialis side first (Video 5), otherwise the radial artery may become difficult to visualize as it may be ‘hidden’ below the brachioradialis muscle, especially in patients with overdeveloped muscular forearm. In fact, leaving the flexor carpi side of the side branches and tissues pulls the radial artery in the midline. Then, the flexor carpi side of the radial artery is dissected free up to the antecubital fossa (Video 6). If required, any residual side branches on the inferior aspect are divided (Photo 4). The artery dissector (‘hook’), is then used in order to confirm the absence of any residual side branches (Video 7).
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Video 4 Endoscopic view: the fascia between the brachioradialis and the flexor carpi muscles is divided up to the antecubital fossa, avoiding potential injuries to any muscular structure, even if the radial artery runs below the brachioradialis muscle rather than the midline.
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Video 5 The radial artery is dissected free on the brachioradialis side along its entire length; such maneuver enhances a more medial positioning of the radial artery.
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Video 6 Dissection is continued on the flexor carpi side. A vigorous pulsation of the radial artery can be appreciated during harvesting.
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Video 7 The absence of residual side branches is assessed by means of the hook.
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We routinely perform an additional 1.5-cm incision near the antecubital space for proximal ligation (Photo 5). A blunt tissue dissection is performed under endoscopic control, using the tip of the dissector as a landmark. A tape is then looped around the radial artery and secured in a tourniquet (Video 8): in case any residual side branch should have been missed during the final assessment with the hook, once the radial artery has been divided distally following heparinization (in order to be pulled out from the forearm) it would be otherwise impossible to divide any tissutal remnant via the endoscopic view; in such instance, the tourniquet can be snared down allowing to complete the residual tissue dissection. The radial artery is divided at the level of the wrist and pulled out from the proximal incision (at the level of the antecubital fossa) (Video 9), clipped at the distal end, and plunged into wet gauzes with warm papaverine outside the forearm, thus maintaining the radial artery perfused as much as possible (Photo 6).
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Photo 5 As the tip of the retractor lies above the proximal end of the dissected radial artery, it is used as a guide for the proximal incision. Red circles are depicting the proximal and distal incisions, respectively.
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Video 8 A tape is passed around the radial artery and secured in a snugger outside the arm.
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Video 9 The radial artery is divided at the level of the wrist and pulled out from the incision at the level of the antecubital fossa.
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Photo 6 The distal side of the radial artery is divided but not the proximal side so as to preserve blood perfusion.
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Results
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ERAH has been performed in 76 patients according to the previously described technique. In particular, along with the reusable Storz endoscopic radial artery retractor, the Harmonic scalpel has been used in 39 patients (51%), the Enseal device in 34 patients (45%), and finally the Starion device in 3 patients (4%) (Graph 1). Nevertheless, the Enseal device has progressively become our preferred device of choice, due to the peculiar nanostructure in the jaws that allows a better temperature control. Harvesting time consistently dropped following the initial cases, similarly to what has been reported by other authors [3, 4, 5]: in fact, once the initial learning curve has reached the plateau phase, the average harvesting time is around 25–30 min (Graph 2). Of note, despite all cases being safely performed with the different vessel sealing systems, we found less smoke production and less charring with the Enseal system. No conversion to the open technique was required due to bleeding. No complications were observed in terms of postoperative ischemia, wound complications, hematomas, and permanent neurological dysfunction, while we observed a transient postoperative sensation alteration in 5 patients (6.5%), that spontaneously resolved in the following months. Excellent aesthetic results were achieved a few weeks after the procedure (Photo 7).
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Photo 7 The arrows depict the excellent wound healing of the surgical mini-incisions three weeks after the procedure.
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Conclusions
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The use of the endoscopic approach for radial artery harvesting offers several advantages when compared to the open technique in terms of wound complications, wound infections, hematomas, less neurological complications, and improved aesthetics [3, 4, 5, 6, 7, 8]. The advantages in terms of reduced neurological injuries are mostly related to the careful dissection of the distal part of the radial artery (therefore minimizing the trauma to the superficial branch of the radial nerve) and to the avoidance of manipulation to the lateral cutaneous antebrachial nerve (running along the brachioradialis nerve), thanks to the different route (below the brachioradialis muscle). Moreover, this technique allows reduced trauma and manipulation of the radial artery itself during harvesting, therefore contributing to a critical issue for long-term conduit patency, i.e. preservation of the arterial wall and the endothelial morphology and function. In particular, other authors demonstrated the same degree of patency rates when radial arteries harvested with the endoscopic technique were compared with the open technique [9]. Finally, the endoscopic technique provides ample patient satisfaction, especially in terms of length of the surgical incision when compared to the conventional approach.
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Footnotes
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1 Dr. Bisleri discloses a financial interest with Karl Storz GmbH. 
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References
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- Reyes AT, Frame R, Brodman RF. Technique for harvesting the radial artery as a coronary artery bypass graft. Ann Thorac Surg 1995;59:118–126.[Abstract/Free Full Text]
- Allen K, Cheng D, Cohn W, Connolly M, Edgerton J, Falk V, Martin J, Ohtsuka T, Vitali R. Endoscopic vascular harvest in coronary artery bypass grafting surgery: a consensus statement of the International Society of Minimally Invasive Cardiothoracic Surgery (ISMICS) 2005. Innovations 2005;151–60.
- Connolly MW, Torrillo LD, Stauder MJ, Patel NU, McCabe JC, Loulmet DF, Subramanian VA. Endoscopic radial artery harvesting: results of first 300 patients. Ann Thorac Surg 2002;74:502–506.[Abstract/Free Full Text]
- Casselman FP, La Meir M, Cammu G, Wellens F, De Geest R, Degrieck I, Van Praet F, Vermeulen Y, Vanermen H. Initial experience with an endoscopic radial artery harvesting technique. J Thorac Cardiovasc Surg 2004;128:463–466.[Abstract/Free Full Text]
- Patel AN, Henry AC, Hunnicutt C, Cockerham CA, Willey B, Urschel HC Jr. Endoscopic radial artery harvesting is better than the open technique. Ann Thorac Surg 2004;78:149–153.[Abstract/Free Full Text]
- Newman RV, Lammle WG, Matz KJ. Cost effective endoscopic radial artery harvesting. Ann Thorac Surg 2006;82:353–354.[Abstract/Free Full Text]
- Nickum CW, Boyd WD, Novick RJ, Blackstone EH, Apperson-Hanson C, McAuliffe JA. Division of the brachioradialis muscle: a modification of the current technique in endoscopic radial artery harvesting. Heart Surg Forum 2005;8:E449–E452.[CrossRef][Medline]
- Bisleri G, Piccoli P, Hrapkowicz T, Birtan H, Muneretto C. Nanoscale radiofrequency control technology for endoscopic radial artery harvesting: a case report. Heart Surg Forum 2006;9:E700–E702.[CrossRef][Medline]
- Bleiziffer S, Hettich I, Eisenhauer B, Ruzicka D, Wottke M, Hausleiter J, Martinoff S, Morgenstern M, Lange R. Patency rates of endoscopically harvested radial arteries one year after coronary artery bypass grafting. J Thorac Cardiovasc Surg 2007;134:649–656.[Abstract/Free Full Text]
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Summary
Background
