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Mammary artery grafts: A new no-touch technique for anastomosis
HOW TO DO IT
Mammary Artery Grafts: A New No-Touch Technique for Anastomosis Ivor F. Galvin, FRCSI Department of Cardiothoracic Surgery, The Prince Henry Hospital, Sydney, Australia
Reported techniques for mammary artery-coronary artery anastomosis involve instrumental damage to one or all three layers of the mammary artery during surgical connection. Described herein is an atraumatic method of suturing that achieves a precise and highly accurate anastomosis. (Ann Thorac Surg 1991;51:500-3)
D
espite widespread acclaim and the emerging evidence regarding the superiority [l-31 of the mammary artery as a conduit for coronary revascularization, universal acceptance by surgeons has not occurred. It is an interesting and curious fact that despite all that has been written about mammary artery grafts over the past 20 years, in only 36.9% of coronary operations in the US are mammary arteries routinely employed [4]. Of the 243,000 coronary operations performed in the US in 1987, the proportion involving single internal mammarycoronary artery bypass grafts was 31.6% and double internal mammary-coronary artery bypass grafts, 5.3%. This confusing contradiction between surgical practice and the accepted virtues of the mammary artery graft confirms the obvious: factors other than the mammary artery, the so-called lasting conduit [l], influence the surgeon. Although some have brought mammary artery grafting to state-of-the-art perfection [ 1, 51, others find graft harvest laborious and time consuming and the anastomosis of this vasoactive artery either unsatisfactory or technically difficult. Mammary arteries, being friable conduits, poorly tolerate instrumental handling. Mammary artery-coronary artery anastomosis as commonly performed necessarily involves holding either the adventitia or the full thickness of the mammary artery with a forceps at its cut end to stabilize the tissue for suturing. The artery is often held circumferentially in different places by the surgeon or the assistant while the anastomosis is performed. The common practice of excluding the traumatized areas from the anastomosis by stitching them out makes for a smaller than desirable anastomosis and may lead to late anastomotic stricture. Apart from trauma there is a need for a good method to stabilize and expose the vessel for expeditious and accurate suturing. The approach presented
here, including a novel atraumatic technique at the anastomosis, overcomes these problems.
Material and Methods Technique of Harvest and Preparation The internal mammary artery is harvested on a pedicle after two parallel diathermy tracks are made along the inner chest wall 1.0 cm on either side of the artery along its entire length. Using low-intensity electrocautery, a dissecting diathermy spatula is then used to separate the mammary pedicle from the chest wall in a medial to lateral direction. When the pedicle hangs loose but is still attached at both ends, careful inspection of its upper aspect is made and the intercostal vessels are identified and clipped with a titanium clip applicator. The vessel is then lavaged with papaverine and wrapped in a soaked gauze pad while cannulation takes place. Before the commencement of bypass, the distal aspect of the mammary artery is divided and the pedicled vessel is laid longitudinally on a large gauze pad on top of the heart. A small Dietrich clip is applied transversely at the level of the mid portion of the pedicle (Fig 1A). The distal pedicle and clip are now rotated 180 degrees clockwise (Fig 1B). The distal aspect of the pedicle now has its muscular surface uppermost. The assistant now holds the end of the mammary artery in a downward manner with a fine forceps in the left hand while holding the muscular aspect of his or her side of the pedicle with a forceps in the right hand (Fig 1C).The surgeon holds the other side of the muscular pedicle and with sharp scissors cuts longitudinally for 3.0 cm, bifurcating the muscle and exposing clearly the vessel itself (Fig 1D).The muscle on both sides is now trimmed from the vessel. A coronary scissors is now introduced into the lumen of the vessel and a 2.0-cm proximal arteriotomy is made. The vessel is now ready for coronary anastomosis. At this point a dilute papaverine [6] and blood solution is injected up the mammary lumen while the artery clip is repositioned to the distal aspect of the muscular pedicle to allow the vessel to vasodilate before anastomosis.
No-Touch Technique of Anastomosis Accepted for publication Oct 29, 1990. Address reprint requests to h4r Galvin, Department of Cardiothoracic Surgery, Clinical Sciences Building, The Prince Henry Hospital, Anzac Parade, Little Bay, NSW 2036, Australia.
0 1991 by The Society of Thoracic Surgeons
The distal mammary artery now projecting from the muscular pedicle is denuded, longitudinally arteriotomized on its muscular side, and redundant. This redundant portion of the vessel is for handling and is removed 0003-4975/91/$3.50
HOW TO DO IT GALVIN NO-TOUCH IMA
Ann Thorac Surg 1991;51:50&3
A
501
W
B
Fig I . Preparation of internal mammary artery: (A) harvested supine graft pedicle, (B)pronated pedicle, (C, D)skeletonization of distal internal mamma y artery, (E)longitudinal mamm a y arteriotomy, forceps holding internal mammary artery projection.
during the anastomosis. The assistant first holds the vessel with the forceps so it hangs from the left-sided chest drapes by its pedicle into the pericardial cavity (Fig 1E). The weight of the pedicle and the assistant’s hold on the artery stabilize the vessel in a very satisfactory fashion for the surgeon, who now places the first suture one stitch distance from the heel of the mammary arteriotomy (Fig 2A). A running mammary artery-coronary artery suture is done with the mammary artery in the held-up position and goes from outside the mammary artery in, in a counterclockwise fashion to one stitch distance on the other side of the heel. The vessel is now lowered into position as both ends of
the 8-0 Prolene suture are pulled taut (Fig 2B). This completes the heel of the anastomosis without surgeon or assistant ever catching the cut aspect of the sutured vessel that is connected to the coronary artery. The surgeon now holds the distal aspect of the redundant mammary artery with forceps in the left hand and quickly does a running suture down the right aspect of the anastomosis. When he or she is two stitches from the toe of the anastomosis, he or she diagonally cuts ab, the redundant remaining mammary artery, in a 45-degree fashion (Fig 2C). The surgeon completes the anastomosis as far as the toe b by catching the projecting redundant mammary angle c (Fig 2D). When the toe stitch is inserted a second oblique mammary
502
HOW TO DO IT NO-TOUCH IMA
GALVIN
Ann Thorac Surg 1991;51:5o(M
D
- A
- --
F
-
C
Fig 2 . No-touch anastomotic technique: (A) suturing the mammay coronay heel, (B)seating of heel and continuing the anastomosis, (C, D, E ) progressive fashioning and fixing the mammay-coronay toe using forceps only on internal mamm a y a r t e y projection, (F, G) completion of anastomosis, internal mamma y a r t e y projection discarded.
G
HOWTODOIT GALVIN NO-TOUCH IMA
Ann Thorac Surg 19!31;51:50&3
arteriotomy (bd) is made (Fig 2E), and the redundant portion of the artery is progressively removed while a continual running suture easily completes the anastomosis (Fig 2F) without any instrumental damage to the implanted mammary artery. The mammary clip is momentarily released to allow coronary filling and anastomotic expansion as the knot is tied (Fig 2G).
Comment Some surgeons are reluctant to employ mammary artery grafts because of past experiences with vasospasm or because they find them technically demanding [2]. Reported results [l,5, 7-91 and patency rates for mammary artery grafts widely vary. Poor results may be due to inappropriate selection [5, 7, 91 of patients for mammary grafting, damage to the pedicle during harvest [3], external compression due to over-zealous attempts at pericardial closure, and trauma and technical faults at the anastomosis [3]. This atraumatic method of mammary artery handling, the forceps-less approach to the cut aspect of the mammary artery, eliminates damage to the mammary artery at the anastomosis and satisfactorily stabilizes the vessel for suturing. It is hoped that this paper will encourage those who still have doubts about the mammary artery graft and who would like a method that is quick and easy to perform, is atraumatic, and gives high-quality exposure and reproducible results. Appreciation and thanks are expressed to Marcus Cremonese (Department of Medical Illustration, Prince of Wales Hospital, Sydney) for artwork.
503
References 1. Okies JE, Page IS, Bigelow JC, Krause AH, Salomon NW. The left internal mammary artery: the graft of choice. Circulation 1984;7O(Suppl 1):213-21. 2. Loop FD, Lytle BW, Cosgrove DM, et al. Influence of the internal-mammary-artery graft on 10-year survival and other cardiac events. N Engl J Med 1986;3141-6. 3. Tector A], Schmahl TM, Canino VR. The internal mammary artery graft: the best choice for bypass of the diseased left anterior descending coronary artery. Circulation 1983; 68(SuppI2):214-7. 4. Vital and health statistics: detailed diagnoses and procedures, National Hospital Discharge Survey, 1987 (DHHS Publication No. (PHS) 89-1761). Hyattsville, MD: US Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Center for Health Statistics, March 1989. 5. Cosgrove DM, Lytle BW, Loop FD, et al. Does bilateral internal mammary artery grafting increase surgical risk? J Thorac Cardiovasc Surg 1988;95:85M. 6. Mills NL, Bringaze WL 111. Preparation of the internal mammary artery graft: which is the best method? J Thorac Cardiovasc Surg 1989;98:73-9. 7. Grondin CM, Campeau L, Lesperance J, Enjalbert M, Bourassa MG. Comparison of late changes in internal mammary artery and saphenous vein grafts in two consecutive series of patients 10 years after operation. Circulation 1984; 70(Suppl 1):208-12. 8. Fiore AC, Naunheim KS, Dean P, et al. Results of internal thoracic artery grafting over 15 years: single versus double grafts. Ann Thorac Surg 1990;49:202-9. 9. Olearchyk AS, Magovern GJ. Internal mammary artery grafting: clinical results, patency rates, and long-term survival in 833 patients. J Thorac Cardiovasc Surg 1986;921082-7.
Mammary Artery Grafts: A New No-Touch Technique for Anastomosis Ivor F. Galvin, FRCSI Department of Cardiothoracic Surgery, The Prince Henry Hospital, Sydney, Australia
Reported techniques for mammary artery-coronary artery anastomosis involve instrumental damage to one or all three layers of the mammary artery during surgical connection. Described herein is an atraumatic method of suturing that achieves a precise and highly accurate anastomosis. (Ann Thorac Surg 1991;51:500-3)
D
espite widespread acclaim and the emerging evidence regarding the superiority [l-31 of the mammary artery as a conduit for coronary revascularization, universal acceptance by surgeons has not occurred. It is an interesting and curious fact that despite all that has been written about mammary artery grafts over the past 20 years, in only 36.9% of coronary operations in the US are mammary arteries routinely employed [4]. Of the 243,000 coronary operations performed in the US in 1987, the proportion involving single internal mammarycoronary artery bypass grafts was 31.6% and double internal mammary-coronary artery bypass grafts, 5.3%. This confusing contradiction between surgical practice and the accepted virtues of the mammary artery graft confirms the obvious: factors other than the mammary artery, the so-called lasting conduit [l], influence the surgeon. Although some have brought mammary artery grafting to state-of-the-art perfection [ 1, 51, others find graft harvest laborious and time consuming and the anastomosis of this vasoactive artery either unsatisfactory or technically difficult. Mammary arteries, being friable conduits, poorly tolerate instrumental handling. Mammary artery-coronary artery anastomosis as commonly performed necessarily involves holding either the adventitia or the full thickness of the mammary artery with a forceps at its cut end to stabilize the tissue for suturing. The artery is often held circumferentially in different places by the surgeon or the assistant while the anastomosis is performed. The common practice of excluding the traumatized areas from the anastomosis by stitching them out makes for a smaller than desirable anastomosis and may lead to late anastomotic stricture. Apart from trauma there is a need for a good method to stabilize and expose the vessel for expeditious and accurate suturing. The approach presented
here, including a novel atraumatic technique at the anastomosis, overcomes these problems.
Material and Methods Technique of Harvest and Preparation The internal mammary artery is harvested on a pedicle after two parallel diathermy tracks are made along the inner chest wall 1.0 cm on either side of the artery along its entire length. Using low-intensity electrocautery, a dissecting diathermy spatula is then used to separate the mammary pedicle from the chest wall in a medial to lateral direction. When the pedicle hangs loose but is still attached at both ends, careful inspection of its upper aspect is made and the intercostal vessels are identified and clipped with a titanium clip applicator. The vessel is then lavaged with papaverine and wrapped in a soaked gauze pad while cannulation takes place. Before the commencement of bypass, the distal aspect of the mammary artery is divided and the pedicled vessel is laid longitudinally on a large gauze pad on top of the heart. A small Dietrich clip is applied transversely at the level of the mid portion of the pedicle (Fig 1A). The distal pedicle and clip are now rotated 180 degrees clockwise (Fig 1B). The distal aspect of the pedicle now has its muscular surface uppermost. The assistant now holds the end of the mammary artery in a downward manner with a fine forceps in the left hand while holding the muscular aspect of his or her side of the pedicle with a forceps in the right hand (Fig 1C).The surgeon holds the other side of the muscular pedicle and with sharp scissors cuts longitudinally for 3.0 cm, bifurcating the muscle and exposing clearly the vessel itself (Fig 1D).The muscle on both sides is now trimmed from the vessel. A coronary scissors is now introduced into the lumen of the vessel and a 2.0-cm proximal arteriotomy is made. The vessel is now ready for coronary anastomosis. At this point a dilute papaverine [6] and blood solution is injected up the mammary lumen while the artery clip is repositioned to the distal aspect of the muscular pedicle to allow the vessel to vasodilate before anastomosis.
No-Touch Technique of Anastomosis Accepted for publication Oct 29, 1990. Address reprint requests to h4r Galvin, Department of Cardiothoracic Surgery, Clinical Sciences Building, The Prince Henry Hospital, Anzac Parade, Little Bay, NSW 2036, Australia.
0 1991 by The Society of Thoracic Surgeons
The distal mammary artery now projecting from the muscular pedicle is denuded, longitudinally arteriotomized on its muscular side, and redundant. This redundant portion of the vessel is for handling and is removed 0003-4975/91/$3.50
HOW TO DO IT GALVIN NO-TOUCH IMA
Ann Thorac Surg 1991;51:50&3
A
501
W
B
Fig I . Preparation of internal mammary artery: (A) harvested supine graft pedicle, (B)pronated pedicle, (C, D)skeletonization of distal internal mamma y artery, (E)longitudinal mamm a y arteriotomy, forceps holding internal mammary artery projection.
during the anastomosis. The assistant first holds the vessel with the forceps so it hangs from the left-sided chest drapes by its pedicle into the pericardial cavity (Fig 1E). The weight of the pedicle and the assistant’s hold on the artery stabilize the vessel in a very satisfactory fashion for the surgeon, who now places the first suture one stitch distance from the heel of the mammary arteriotomy (Fig 2A). A running mammary artery-coronary artery suture is done with the mammary artery in the held-up position and goes from outside the mammary artery in, in a counterclockwise fashion to one stitch distance on the other side of the heel. The vessel is now lowered into position as both ends of
the 8-0 Prolene suture are pulled taut (Fig 2B). This completes the heel of the anastomosis without surgeon or assistant ever catching the cut aspect of the sutured vessel that is connected to the coronary artery. The surgeon now holds the distal aspect of the redundant mammary artery with forceps in the left hand and quickly does a running suture down the right aspect of the anastomosis. When he or she is two stitches from the toe of the anastomosis, he or she diagonally cuts ab, the redundant remaining mammary artery, in a 45-degree fashion (Fig 2C). The surgeon completes the anastomosis as far as the toe b by catching the projecting redundant mammary angle c (Fig 2D). When the toe stitch is inserted a second oblique mammary
502
HOW TO DO IT NO-TOUCH IMA
GALVIN
Ann Thorac Surg 1991;51:5o(M
D
- A
- --
F
-
C
Fig 2 . No-touch anastomotic technique: (A) suturing the mammay coronay heel, (B)seating of heel and continuing the anastomosis, (C, D, E ) progressive fashioning and fixing the mammay-coronay toe using forceps only on internal mamm a y a r t e y projection, (F, G) completion of anastomosis, internal mamma y a r t e y projection discarded.
G
HOWTODOIT GALVIN NO-TOUCH IMA
Ann Thorac Surg 19!31;51:50&3
arteriotomy (bd) is made (Fig 2E), and the redundant portion of the artery is progressively removed while a continual running suture easily completes the anastomosis (Fig 2F) without any instrumental damage to the implanted mammary artery. The mammary clip is momentarily released to allow coronary filling and anastomotic expansion as the knot is tied (Fig 2G).
Comment Some surgeons are reluctant to employ mammary artery grafts because of past experiences with vasospasm or because they find them technically demanding [2]. Reported results [l,5, 7-91 and patency rates for mammary artery grafts widely vary. Poor results may be due to inappropriate selection [5, 7, 91 of patients for mammary grafting, damage to the pedicle during harvest [3], external compression due to over-zealous attempts at pericardial closure, and trauma and technical faults at the anastomosis [3]. This atraumatic method of mammary artery handling, the forceps-less approach to the cut aspect of the mammary artery, eliminates damage to the mammary artery at the anastomosis and satisfactorily stabilizes the vessel for suturing. It is hoped that this paper will encourage those who still have doubts about the mammary artery graft and who would like a method that is quick and easy to perform, is atraumatic, and gives high-quality exposure and reproducible results. Appreciation and thanks are expressed to Marcus Cremonese (Department of Medical Illustration, Prince of Wales Hospital, Sydney) for artwork.
503
References 1. Okies JE, Page IS, Bigelow JC, Krause AH, Salomon NW. The left internal mammary artery: the graft of choice. Circulation 1984;7O(Suppl 1):213-21. 2. Loop FD, Lytle BW, Cosgrove DM, et al. Influence of the internal-mammary-artery graft on 10-year survival and other cardiac events. N Engl J Med 1986;3141-6. 3. Tector A], Schmahl TM, Canino VR. The internal mammary artery graft: the best choice for bypass of the diseased left anterior descending coronary artery. Circulation 1983; 68(SuppI2):214-7. 4. Vital and health statistics: detailed diagnoses and procedures, National Hospital Discharge Survey, 1987 (DHHS Publication No. (PHS) 89-1761). Hyattsville, MD: US Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Center for Health Statistics, March 1989. 5. Cosgrove DM, Lytle BW, Loop FD, et al. Does bilateral internal mammary artery grafting increase surgical risk? J Thorac Cardiovasc Surg 1988;95:85M. 6. Mills NL, Bringaze WL 111. Preparation of the internal mammary artery graft: which is the best method? J Thorac Cardiovasc Surg 1989;98:73-9. 7. Grondin CM, Campeau L, Lesperance J, Enjalbert M, Bourassa MG. Comparison of late changes in internal mammary artery and saphenous vein grafts in two consecutive series of patients 10 years after operation. Circulation 1984; 70(Suppl 1):208-12. 8. Fiore AC, Naunheim KS, Dean P, et al. Results of internal thoracic artery grafting over 15 years: single versus double grafts. Ann Thorac Surg 1990;49:202-9. 9. Olearchyk AS, Magovern GJ. Internal mammary artery grafting: clinical results, patency rates, and long-term survival in 833 patients. J Thorac Cardiovasc Surg 1986;921082-7.