Thoracoscopic Transmyocardial Laser Revascularization

Thoracoscopic Transmyocardial Laser Revascularization Keith Horvath

espite tile success of treating coronary artery disease with conventional methods, such as coronary artery bypass grafting (CABG) and pcrcutancous transcoronary-an~oplasty (PTCA) with stenting, a si~fificant and gTOWhlgnumber of patients have exhausted the ability to repeatedly tmdergo these procedures, primarily because of tile diffuse nature of their coronary artery disease. As a restdt of this severe coronary artery disease, they have chronic disabling anghm that is refractory to medical therapy. Transmyocardial laser revascldarization (TMR) has been developed to treat these lmticnts. Ahhough Mirhoseilfi~,2 and Okada 3 used a laser to perform tiffs type of revascularization in conjunction ~dth coronary artery bypass gu'afting ill the early 1980s, the use of a laser as sole therapy reqtfired advancements in the technolo~,. After hnprovements in tile laser that allowed carbon dioxide TMR to be performed on a beating heart, restdts from individual hlstitutions1,5 and from mtdti center trials 6-8 in 1995 through 1997 demonstrated a dramatic hnprovement in the symptomatic relief of an~na, both short-term and beyond five years9. As a result of the success of the procedure, TMR has obtained FDA approval and has been performed on

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more than 6,000 patients around tile world. Typically, tile procedure involves a limited left anterior thoracotomy with exposure of tile left ventricle through this incision. Tile thoracotomy typically is 18 to 20 cm in tile fifth intercostal space. Through this large incision, tile l~ericardinm is opened, and tile left ventricular free wall is drilled with a laser. Tile l-ram channels are created in a distribution of 1 cm, after which most patients are extubatcd in the operating room. Occasionally, tile difticuhy in recovering from a thoracotomy has also increased the patient's length of stay. The average length of stay for this procedure is seven or eight days. 4-a Because the revascularization achieved by TMR is not immediate, and because postoperative pain managemcllt is tints critical in reducing the morbidity of the procedure, we have developed a method of perfornfing tile operation in a less-invasive fashion with videoseopic assistance. This minimally invasive technique uses a thorascope, standard instrumentation, and the same laser equipment as nsed to perform TMR via a thoracotomy. I have previously described tile performance of thorascopic TMR in both an animal model and in treating patients.W.n

Operative Techniques ill 'Fhq*racic and Cardiovascular Surgery, Vol 6, No 3 (August), 2 0 0 1 : pp 132o139

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TIIORACOSCOIqC TMR

S U R G I C A l , TECHNIQUE

Line of incision in 5th intercostal space for open TMR

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1 Transmyoeardial laser revascularization 1)erformed as an open surgical procedure is typically ,lone through a left anterolateral thoracotomy in tile fifth intercostal SlmCe. Tile patient is placed ill a supine 1,osition with a roll under tile left side from tile shouhler to the waist to elevate tile left llemitllorax. Skin prelmration includes at least one or both groins, lmrticularly in patients with low ejection fractions or unstable angina, who may require intraoperative placement of an intra-aortic balloon pump. After adequate general endotracheal anesthesia is established, all 8- to 12- cm skin incision is made as shown. Tips for general anesthesia inclnde using a ,louble-lumen tube or a broncllial blocker to isolate tile left lung and using a thoracic el,idural catheter to provide postol)erative 1)ain control. Exposure of tile heart through this incision typically call be achieved without division of tile ribs or costal cartilages.

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KEITII IIORVAT

Open TMR Laser handpiece

Laser chan,,~,o in leftventricle

2 Once the ribs are spread by a retractor and tile lung is deflated, the pericardium is opened to expose tile epieardial surface of tile heart. Care must be taken to avoid previous bylmss grafts. Tile left anterior descending artery is identified and used as a l a n d m a r k for locating the septum. The inferior and posterior lateral portions of the heart can be reached through this incision with a combination of nmnual traction and placement of packing behind the heart and, as illustrated, the use of a right-angled laser lmudpiece. Channels are created starting n e a r the base of the heart and then serially i n a line alJproximately one em a p a r t toward the apex, beginning inferiorly and then working superiorly to the anterior surface of the heart. Because there is some bleeding from the channels, starting the TMR inferiorly keeps the anterior area clear and expedites the procedure. The n u m b e r of channels created ,lepends on the size of the heart and on the size of the ischemie area. Myocardinm that is tlfinned by scar, particularly when the sear is transmural, should be avoide,l, because TMR will be of no benefit to these re~ons, and bleeding from channels in these areas nmy be problematic. Trausesophageal echocardiography (TEE) shouhl be used to confirm transmural penetration of the laser energy. Vaporization of blood by the laser energy as the laser beam enters the ventricle creates an obvious and characteristic acoustic effect as noted on TEE.

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TIIOILtCOSCOPIC TMR

Triangulated intercostal placement of thoracoscopic tools for TMR

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Thoracoscope with grasper in 5th intercostal space

3 To minimize postoperative incisional pain, lmrtieularly in patients who have not had previous bypass surgery, the TMR procedure can be performed with video-assisted thoracoscopy. Again, the patient is positioned supine with the left hemithorax elevated by a roll. The left upper extremity may also be retracted cranially to facilitate thoracoscope placement. The thoracoscopic ports may be placed in the fifth or the fourth intercostal space. Through the same 10-ram port incision used for the thoracoscope, an endoscopic grasper may be placed to facilitate the dissection. Once the camera has been placed, additional ports can be created under thoracoscopic guidance. Because the heart is immediately adjacent to the chest wall, endoscopic instrnmentation may not be necessary, and standard instruments may be introduced through these additional incisions. The incisions should be triangulated to provide maxinmm facility for dissection and exposure.

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KEITI! IIORVATII

Incision of pericardium over left ventricle

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4 This is tile view from the thoracoscopc showing tile grasper, which is placed through tile same thoracoscope incision at six o'clock on this picture, and an additional grasper placed through a third intercostal incision port at one o'clock. These two graspers are used to elevate and selmrate tile l~ericardimn, which is divided using standard dissecting scissors placed through a more anterior fifth intercostal incision. Care is taken to avoid the left phrenic nerve during this dissection.

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TIIOIIACOSCOI'ICTMR

Laser handpiece on left ventricle

5 Laser handlficces can be introduced through any of tile ports with replacement of the thoracoscope as needed to allow the creation of TMR channels oil all areas of the left ventrieular surface. Ilere a straight handpiece is being introduced through tile third intercostal incision. Using a combination of straight and right-angled handpieces, all surfaces can be covered. Bleeding from the channels is controlled with either direct finger pressure or a sponge stick placed after the handpiece is removed.

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KEITII IIORVATII

Procedure completed with closure and drainage of thoracic wounds

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6 Tile thorascoi)ic incisions are closed with three layers of absorbable suture, and a dry sterile dressing is al)i)lied. A chest tube is placed through one of the fifth intercostal incision sites to provide adequate postoperative evacuation of air and/or fluid from tile pleural cavity.

TIIOHACOSCOPIC TMR Collllllent

Minimally invasive procedures have been used in other lncthods of revascularization, and it, seems appropriate to use these techniques for patients undergoing TMR. Because coronary artery disease in these patients is by detinition more severe than that in patients undergoing bypass procedures, postoperative pain control and concomitant respiratory therapy are of critical importance. This procedure can be done easily without additional instrumentation. It is obviously most appropriate for patients who have not had previous CABG. It may also be performed in conjunction with nfinimally invasive off-pump bylmss surgery. Placement of an initial camera port in the lateral fifth intercostal space in all patients, regardless of previous procedures, will allow the surgeon to determine whether it will be feasible to perform the procedure thoracoseopieally or whether it will be necessary to extend the incision anteriorly and perform the operation through a thoraeotomy. The anterior fifth intercostal port incision can also be used as the chest tube site for the thoracoseopic procedure. The described thoraeoscopie approach permits the same transmural revascularization as is achieved through a thoracotomy and has provided the same an~na relief for patients. REFERENCES 1. Mirhoseini M, Cayton M: Revaseularization of the heart by laser. J Microsurg 2:253-260, 1981

139 2. Mirhoseini 5I, Shel~kar S, Cayton MM: New concepts in revascularizatiou of the myocardium. Ann Thorac Surg ,15:.115-120, 1988 3. Okada M, Ikuta II, Shimizu K, et al: Ahernative method of myocardial revascularization by laser: exl)erimcntal anti clinical study. Kobe J Meal Sei 32:151-161, 1986 4. Frazier 0II, Cooley DA, Kadipasaoglu IG~., et al: Myocardial revaseularization with laser: preliminary findings. Circulation 92:II-58-II-65, 1995 5. Ilorvath KA, Maunting F, Cummings N, et al: Transmyoeardial laser revaseularization: Operative techniques and clinical results at two years. J Thorac Cardiovasc Snrg 111:1017-1053, 1996 6. Vincent JG, Bardos P, Kruse J, et al: End stage coronary artery disease treated with the transmyocardial CO z laser revascularization: A chance for the "inoperable" patient. Eur J Cardiothorae Surg 121:888-891, 1997 7. Ilorvath I~,, Cohn LII, Cooley DA, et al: Transmyocardiai laser revascularization: results of a muhieentcr trial with transmyoeardial laser revaseularization used as sole therapy for end-stage coronary artery disease. J Thorac Cardiovasc Surg 113:615-651, 1997 8. Dowling RD, Petraeek MR, Selinger SL, et al: Trausmyocardiai revaseularization in patients with refractory, unstable an~na. Circulation 98:II-73-II-76, 1998 9. IIorvath I~$, Aranki SA, Cohn LII, et al: Sustained au~na relief five )ears after transmyocardial revascnlarizatiou with a CO z laser. Circulation 102:II-761, 2000 10. DeGuzmau BJ, Lautz DB, Chert FY, et al: ThoracoscolfiC trausmyocardial laser revascularization. Ann Thorae Surg 61:171-174, 1997 11. llorvath I~,: Thoracoscopic transmyoeardial laser revaseularization. Ann Thorac Surg 65:1439-1,111, 1998

From the Division of Cardiothoraeic Surgery, Northwestern University Medical School, Chicago, IL. Address reprint requests to Keith llor,'ath, MD, 201 E. lluron Street, Suite 10-105, Chicago, IL 60611. Copyright 9 2001 by W.B. Saunders Company 1522 -2942/01/0603-0002535.00/0 doi:l 0.1053/otct.2001.23223