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Left Anterior Descending Artery Endarterectomy by Hydrodissection
HOW-TO-DO-IT
How-To-Do-It
Left Anterior Descending Artery Endarterectomy by Hydrodissection Sanjay Kumar, MCh FRCS and R. Unnikrishnan Nair, FRCS ∗ Department of Cardiothoracic Surgery, Yorkshire Heart Centre, Leeds General Infirmary, Leeds, United Kingdom
Complete revascularisation of a diffusely diseased left anterior descending (LAD) coronary artery is best done by endarterectomy in conjunction with coronary artery bypass grafting. We describe a simple, effective, and safe technique of performing LAD endarterectomy by hydrodissection. (Heart, Lung and Circulation 2009;18:289–292) © 2008 Australasian Society of Cardiac and Thoracic Surgeons and the Cardiac Society of Australia and New Zealand. Published by Elsevier Inc. All rights reserved. Keywords. Endarterectomy; Coronary endarterectomy; Left anterior descending artery; Coronary revascularisation; Hydrodissection
Introduction
C
oronary endarterectomy (CE) was performed on blocked arteries before the advent of the coronary artery bypass grafting (CABG) operation [1]. Most surgeons preferred doing it on the larger right coronary artery (RCA) as the risks of peri-operative myocardial infarction (MI) were lower than with left anterior descending artery (LAD) CE [1–3]. Diffusely diseased LAD remains a challenge for both interventional cardiologists and cardiac surgeons. Surgical revascularisation can be accomplished by open CE with reconstruction using internal mammary artery (IMA) onlay patch, with or without additional venous patch, when the IMA is used as a conduit with a degree of operative risk (mortality 9% and incidence of non-fatal MI 7%) [1–4]. There have been previous descriptions of laser endarterectomy and carbon dioxide gas endarterectomy in the past which have not been widely practiced due to their limitations [5,6]. We describe a simple, effective, and safe technique of performing LAD endarterectomy by hydrodissection, which we have been practising for the past 16 years. This can be accomplished through a small arteriotomy and does not require LAD reconstruction.
Technique The LAD is isolated as high as possible. An incision is made on its anterior aspect which does not exceed Received 24 February 2008; received in revised form 18 October 2008; accepted 26 October 2008; available online 31 December 2008 ∗
Corresponding author at: Yorkshire Heart Centre, D Floor, Jubilee Building, Leeds General Infirmary, Great George Street, Leeds LS1 3EX, United Kingdom. Tel.: +44 113 3925790; fax: +44 113 3928092. E-mail address: [email protected] (R.U. Nair).
twice the vessel diameter (Figs. 1A and 2A). A plane of dissection is created between the atheroma and the vessel wall using a fine dissector (Figs. 1A and 2B). Cold saline is injected into this space towards the distal artery using a 20F Abbocath cannula at a steady pressure until a loss of resistance is felt, indicating separation of the atheroma from the vessel wall (Figs. 1B and 2B). The proximal part of the atheroma is divided at a convenient level with scissors or blade. The distal end of the atheroma is milked out of the LAD by gentle traction and massage (Fig. 1D). The newly developed arterial lumen is cleaned of debris and thrombin, using small pieces of wet cotton wool (Fig. 1C). Subsequently this endarterectomised LAD is grafted with pedicled LIMA (mostly) or vein graft (rarely). Over the past 16 years, 2888 patients underwent CABG operation with or without concomitant procedures. Out of these, 238 had endarterectomy of the LAD artery. Of the 238, only LAD endarterectomy was done in 130, LAD + RCA in 92, LAD + circumflex branches (Cx) in 9 and LAD + Cx + RCA in 7. There were 195 (82%) males and 43 (18%) females with mean age of 61.5 (±9.1) and 64.1 (±7.9) years respectively. 193 (81.1%) were performed as an elective procedure and 45 (18.9%) as an urgent/emergency procedure. Anticoagulation was achieved with warfarin (INR ratio of 2–2.5) for 6–12 months along with an antiplatelet agent, which was continued indefinitely after weaning off warfarin. Since 2001, we have used a combination of aspirin and clopidogrel in the first 6 months instead of warfarin after which patients remained on aspirin only. All patients undergoing endarterectomy receive 300 mg of aspirin rectally within the first 12 h after surgery. Thirty day hospital mortality was 13/238 (5.5%). There were no deaths in the group of triple vessel endarterectomy or LAD + Cx. 5/92 of the RCA + LAD group and 8 out of 130 who had isolated LAD endarterectomy died in hospital.
© 2008 Australasian Society of Cardiac and Thoracic Surgeons and the Cardiac Society of Australia and New Zealand. Published by Elsevier Inc. All rights reserved.
1443-9506/04/$36.00 doi:10.1016/j.hlc.2008.10.019
290 HOW-TO-DO-IT
Kumar and Nair LAD endarterectomy
Heart, Lung and Circulation 2009;18:289–292
Figure 1. Intra-operative photograph of the different stages of LAD endarterectomy by hydrodissection.
The acturial survival was noted to be 90% at 5 years and 63% at 10 years. This compares favourably with other large published series by Byrne et al. [2]. Twelve patients underwent re-angiogram, three of which were performed for symptoms. In all but one, the LIMA to LAD was found to be patent. The patient who had bovine arterial graft to the LAD had a blocked graft. The longest interval between operation and re-angiogram was 14 years. In this patient a vein graft to the diagonal developed thrombus at 14 years and had angioplasty and
Figure 2. Schematic diagram showing steps of LAD endarterectomy using the technique of hydrodissection.
stenting, but the LIMA to the endarterectomised LAD was still functioning satisfactorily (Fig. 3).
Comment Diffuse atherosclerosis of the LAD artery remains a challenge as the absence of lumen makes them unsuitable for revascularisation. Under these circumstances complete myocardial revascularisation with an adequate distal runoff can only be achieved by extensive manual endarterectomy and a reconstructive procedure prior to conduit placement [2–4]. Distal traction endarterectomy may be performed through a medium sized arteriotomy and closed with a vein patch, to which an IMA or saphenous vein graft is constructed. The fear of breaking of an endarterectomy specimen may require a direct exposure total endarterectomy of the entire length of the LAD, which is then closed by a long vein patch [2–4]. The IMA is not usually grafted to such an extensive reconstruction. Sharp dissection of adherent atheroma to the coronary arterial wall is time-consuming and difficult. There are, of course potential complications such as incomplete removal of atheroma, snow-plough effect blocking the septal perforators, perforation of artery and distal embolism [1–4]. In early 1990s, there were published reports regarding the use of carbon dioxide laser in surgical coronary endarterectomy [5]. In 1970s a similar technique using carbon dioxide gas endarterectomy with distal coronary bypass was described [6]. However, these procedures have
Kumar and Nair LAD endarterectomy
291
Figure 3. A–D is the still sequences of re-angiogram, showing patency and good flows down the native LAD, 14 years after LIMA graft to an endarterectomised LAD.
their own limitations due to the risk of perforation of the native vessels, distal embolism, increased thrombogenicity and aneurysm formation of endarterectomised arteries [5,6]. Hydrodissection facilitates identifying anatomical planes amongst complex adhesions and its use has been reported in various surgical fields including cardiac surgery [7–10]. The two important objectives for hydrodissection in CE are (i) effective hydrodissection loosens and separates atheroma without placing undue stress on the arterial wall and (ii) accomplishes extensive removal of atheroma including that of the side branches through a small arteriotomy. Compared with other described techniques, we found that hydrodissection was associated with less bleeding, arterial wall damage and complete removal of atheroma [1–6]. We did not have significant ischaemic events in the postoperative period, which was mainly due to the achievement of complete removal of atheroma from the perforators and diagonals. The recent increase in coronary artery stenting and instent restenosis (ISR) has made grafting of the treated vessels more difficult as many blocked stents may need removal before CABG [1,2]. Our experience of endarterec-
tomy with hydrodissection technique has been positive in this situation. In conclusion, complete revascularisation of the diffusely diseased LAD artery can be facilitated by endarterectomy by hydrodissection through a small arterial incision. In our experience it has shown survival benefits and contributes to long-term graft patency.
Acknowledgements We thank Mr. S. Powell and Ms. Ezenee Kolbaba, Department of Medical Illustration, LGI, Leeds Teaching Hospitals, Leeds for their help with the illustrations.
References [1] Tiruvoipati R, Loubani M, Peek G. Coronary endarterectomy in the current era. Curr Opin Cardiol 2005;20(6):517–20. [2] Byrne JG, Karavas AN, Gudbjartson T, Leacche M, Rawn JD, Couper GS, Rizzo RJ, Cohn LH, Aranki SF. Left anterior descending coronary endarterectomy: early and late results in 196 consecutive patients. Ann Thorac Surg 2004;78(3): 867–73. [3] Goldman BS, Christakis GT. Endarterectomy of the left anterior descending coronary artery. J Card Surg 1994;9(2):89–96.
HOW-TO-DO-IT
Heart, Lung and Circulation 2009;18:289–292
292 HOW-TO-DO-IT
Kumar and Nair LAD endarterectomy
[4] Aranki SF. A modified reconstruction technique after extended anterior descending artery endarterectomy. J Card Surg 1993;8(4):476–82. [5] Ollivier JP, Gandjbakhch I, Avrillier S, Delettre E, Bussière JL, Cabrol C. Intraoperative coronary artery endarterectomy with excimer laser. J Thorac Cardiovasc Surg 1990;100(4): 606–11. [6] Barmada B, Diethrich EB. Gas endarterectomy with distal bypass of the coronary arteries. Heart Lung 1975;4(3):397–401.
Heart, Lung and Circulation 2009;18:289–292
[7] Gimbel HV. Hydrodissection and hydrodelineation. Int Ophthalmol Clin 1994;34(2):73–90. [8] Choi TW, Oh CK. Hydrodissection for complete removal of a ranula. Ear Nose Throat J 2003;82(12):946–7, 951. [9] Saxena P, Mejia R, Tam R. Hydrodissection technique of harvesting left internal thoracic artery. Ann Thorac Surg 2005;80(1):355–6. [10] Mejia R, Saxena P, Tam RK. Hydrodissection in redo sternotomies. Ann Thorac Surg 2005;79(1):363–4.
How-To-Do-It
Left Anterior Descending Artery Endarterectomy by Hydrodissection Sanjay Kumar, MCh FRCS and R. Unnikrishnan Nair, FRCS ∗ Department of Cardiothoracic Surgery, Yorkshire Heart Centre, Leeds General Infirmary, Leeds, United Kingdom
Complete revascularisation of a diffusely diseased left anterior descending (LAD) coronary artery is best done by endarterectomy in conjunction with coronary artery bypass grafting. We describe a simple, effective, and safe technique of performing LAD endarterectomy by hydrodissection. (Heart, Lung and Circulation 2009;18:289–292) © 2008 Australasian Society of Cardiac and Thoracic Surgeons and the Cardiac Society of Australia and New Zealand. Published by Elsevier Inc. All rights reserved. Keywords. Endarterectomy; Coronary endarterectomy; Left anterior descending artery; Coronary revascularisation; Hydrodissection
Introduction
C
oronary endarterectomy (CE) was performed on blocked arteries before the advent of the coronary artery bypass grafting (CABG) operation [1]. Most surgeons preferred doing it on the larger right coronary artery (RCA) as the risks of peri-operative myocardial infarction (MI) were lower than with left anterior descending artery (LAD) CE [1–3]. Diffusely diseased LAD remains a challenge for both interventional cardiologists and cardiac surgeons. Surgical revascularisation can be accomplished by open CE with reconstruction using internal mammary artery (IMA) onlay patch, with or without additional venous patch, when the IMA is used as a conduit with a degree of operative risk (mortality 9% and incidence of non-fatal MI 7%) [1–4]. There have been previous descriptions of laser endarterectomy and carbon dioxide gas endarterectomy in the past which have not been widely practiced due to their limitations [5,6]. We describe a simple, effective, and safe technique of performing LAD endarterectomy by hydrodissection, which we have been practising for the past 16 years. This can be accomplished through a small arteriotomy and does not require LAD reconstruction.
Technique The LAD is isolated as high as possible. An incision is made on its anterior aspect which does not exceed Received 24 February 2008; received in revised form 18 October 2008; accepted 26 October 2008; available online 31 December 2008 ∗
Corresponding author at: Yorkshire Heart Centre, D Floor, Jubilee Building, Leeds General Infirmary, Great George Street, Leeds LS1 3EX, United Kingdom. Tel.: +44 113 3925790; fax: +44 113 3928092. E-mail address: [email protected] (R.U. Nair).
twice the vessel diameter (Figs. 1A and 2A). A plane of dissection is created between the atheroma and the vessel wall using a fine dissector (Figs. 1A and 2B). Cold saline is injected into this space towards the distal artery using a 20F Abbocath cannula at a steady pressure until a loss of resistance is felt, indicating separation of the atheroma from the vessel wall (Figs. 1B and 2B). The proximal part of the atheroma is divided at a convenient level with scissors or blade. The distal end of the atheroma is milked out of the LAD by gentle traction and massage (Fig. 1D). The newly developed arterial lumen is cleaned of debris and thrombin, using small pieces of wet cotton wool (Fig. 1C). Subsequently this endarterectomised LAD is grafted with pedicled LIMA (mostly) or vein graft (rarely). Over the past 16 years, 2888 patients underwent CABG operation with or without concomitant procedures. Out of these, 238 had endarterectomy of the LAD artery. Of the 238, only LAD endarterectomy was done in 130, LAD + RCA in 92, LAD + circumflex branches (Cx) in 9 and LAD + Cx + RCA in 7. There were 195 (82%) males and 43 (18%) females with mean age of 61.5 (±9.1) and 64.1 (±7.9) years respectively. 193 (81.1%) were performed as an elective procedure and 45 (18.9%) as an urgent/emergency procedure. Anticoagulation was achieved with warfarin (INR ratio of 2–2.5) for 6–12 months along with an antiplatelet agent, which was continued indefinitely after weaning off warfarin. Since 2001, we have used a combination of aspirin and clopidogrel in the first 6 months instead of warfarin after which patients remained on aspirin only. All patients undergoing endarterectomy receive 300 mg of aspirin rectally within the first 12 h after surgery. Thirty day hospital mortality was 13/238 (5.5%). There were no deaths in the group of triple vessel endarterectomy or LAD + Cx. 5/92 of the RCA + LAD group and 8 out of 130 who had isolated LAD endarterectomy died in hospital.
© 2008 Australasian Society of Cardiac and Thoracic Surgeons and the Cardiac Society of Australia and New Zealand. Published by Elsevier Inc. All rights reserved.
1443-9506/04/$36.00 doi:10.1016/j.hlc.2008.10.019
290 HOW-TO-DO-IT
Kumar and Nair LAD endarterectomy
Heart, Lung and Circulation 2009;18:289–292
Figure 1. Intra-operative photograph of the different stages of LAD endarterectomy by hydrodissection.
The acturial survival was noted to be 90% at 5 years and 63% at 10 years. This compares favourably with other large published series by Byrne et al. [2]. Twelve patients underwent re-angiogram, three of which were performed for symptoms. In all but one, the LIMA to LAD was found to be patent. The patient who had bovine arterial graft to the LAD had a blocked graft. The longest interval between operation and re-angiogram was 14 years. In this patient a vein graft to the diagonal developed thrombus at 14 years and had angioplasty and
Figure 2. Schematic diagram showing steps of LAD endarterectomy using the technique of hydrodissection.
stenting, but the LIMA to the endarterectomised LAD was still functioning satisfactorily (Fig. 3).
Comment Diffuse atherosclerosis of the LAD artery remains a challenge as the absence of lumen makes them unsuitable for revascularisation. Under these circumstances complete myocardial revascularisation with an adequate distal runoff can only be achieved by extensive manual endarterectomy and a reconstructive procedure prior to conduit placement [2–4]. Distal traction endarterectomy may be performed through a medium sized arteriotomy and closed with a vein patch, to which an IMA or saphenous vein graft is constructed. The fear of breaking of an endarterectomy specimen may require a direct exposure total endarterectomy of the entire length of the LAD, which is then closed by a long vein patch [2–4]. The IMA is not usually grafted to such an extensive reconstruction. Sharp dissection of adherent atheroma to the coronary arterial wall is time-consuming and difficult. There are, of course potential complications such as incomplete removal of atheroma, snow-plough effect blocking the septal perforators, perforation of artery and distal embolism [1–4]. In early 1990s, there were published reports regarding the use of carbon dioxide laser in surgical coronary endarterectomy [5]. In 1970s a similar technique using carbon dioxide gas endarterectomy with distal coronary bypass was described [6]. However, these procedures have
Kumar and Nair LAD endarterectomy
291
Figure 3. A–D is the still sequences of re-angiogram, showing patency and good flows down the native LAD, 14 years after LIMA graft to an endarterectomised LAD.
their own limitations due to the risk of perforation of the native vessels, distal embolism, increased thrombogenicity and aneurysm formation of endarterectomised arteries [5,6]. Hydrodissection facilitates identifying anatomical planes amongst complex adhesions and its use has been reported in various surgical fields including cardiac surgery [7–10]. The two important objectives for hydrodissection in CE are (i) effective hydrodissection loosens and separates atheroma without placing undue stress on the arterial wall and (ii) accomplishes extensive removal of atheroma including that of the side branches through a small arteriotomy. Compared with other described techniques, we found that hydrodissection was associated with less bleeding, arterial wall damage and complete removal of atheroma [1–6]. We did not have significant ischaemic events in the postoperative period, which was mainly due to the achievement of complete removal of atheroma from the perforators and diagonals. The recent increase in coronary artery stenting and instent restenosis (ISR) has made grafting of the treated vessels more difficult as many blocked stents may need removal before CABG [1,2]. Our experience of endarterec-
tomy with hydrodissection technique has been positive in this situation. In conclusion, complete revascularisation of the diffusely diseased LAD artery can be facilitated by endarterectomy by hydrodissection through a small arterial incision. In our experience it has shown survival benefits and contributes to long-term graft patency.
Acknowledgements We thank Mr. S. Powell and Ms. Ezenee Kolbaba, Department of Medical Illustration, LGI, Leeds Teaching Hospitals, Leeds for their help with the illustrations.
References [1] Tiruvoipati R, Loubani M, Peek G. Coronary endarterectomy in the current era. Curr Opin Cardiol 2005;20(6):517–20. [2] Byrne JG, Karavas AN, Gudbjartson T, Leacche M, Rawn JD, Couper GS, Rizzo RJ, Cohn LH, Aranki SF. Left anterior descending coronary endarterectomy: early and late results in 196 consecutive patients. Ann Thorac Surg 2004;78(3): 867–73. [3] Goldman BS, Christakis GT. Endarterectomy of the left anterior descending coronary artery. J Card Surg 1994;9(2):89–96.
HOW-TO-DO-IT
Heart, Lung and Circulation 2009;18:289–292
292 HOW-TO-DO-IT
Kumar and Nair LAD endarterectomy
[4] Aranki SF. A modified reconstruction technique after extended anterior descending artery endarterectomy. J Card Surg 1993;8(4):476–82. [5] Ollivier JP, Gandjbakhch I, Avrillier S, Delettre E, Bussière JL, Cabrol C. Intraoperative coronary artery endarterectomy with excimer laser. J Thorac Cardiovasc Surg 1990;100(4): 606–11. [6] Barmada B, Diethrich EB. Gas endarterectomy with distal bypass of the coronary arteries. Heart Lung 1975;4(3):397–401.
Heart, Lung and Circulation 2009;18:289–292
[7] Gimbel HV. Hydrodissection and hydrodelineation. Int Ophthalmol Clin 1994;34(2):73–90. [8] Choi TW, Oh CK. Hydrodissection for complete removal of a ranula. Ear Nose Throat J 2003;82(12):946–7, 951. [9] Saxena P, Mejia R, Tam R. Hydrodissection technique of harvesting left internal thoracic artery. Ann Thorac Surg 2005;80(1):355–6. [10] Mejia R, Saxena P, Tam RK. Hydrodissection in redo sternotomies. Ann Thorac Surg 2005;79(1):363–4.