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Application of Ultrasonic Aspirator for Dissection of the Internal Mammary Artery in Coronary Artery Bypass Grafting
Application of Ultrasonic As irator for Dissection of the Intern Mammary Artery in Coronary Artery Bypass Grafting
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Hisayoshi Suma, M.D., Hitoshi Fukumoto, M.D., and Atsuro Takeuchi, M.D. ABSTRACT The low-power ultrasonic aspirator was used for the dissection of the internal mammary artery (IMA) in 20 patients undergoing coronary artery bypass grafting. Harvesting time was shorter and the amount of bleeding was less than with the ordinary method. The short-term patency rate (1 to 6 months) for those IMA grafts was 95% (19 of 20 remained patent), These results have encouraged us to use the ultrasonic aspirator routinely for IMA dissection. The internal mammary artery (IMA) is considered superior for coronary artery bypass grafting because of its excellent long-term patency [l-41. Its dissection from the chest wall, however, is still a tedious job for the surgeon. We applied an ultrasonic aspirator for IMA dissection in 20 patients and found that harvesting time was shortened and bleeding was minimized compared with the ordinary method.
Technique After the sternum is split, the left side of the chest is retracted upward. We use electric cautery to make the retrosternal incision along the sternal edge in the usual fashion. Muscles and tendons attached to the rib are severed by the cautery, and fat and connective tissues are dissected by the ultrasonic aspirator. The ultrasonic aspirator is used with low-output vibration (usually 8 to 10%) and low-power suction (127 mm Hg) to avoid compromising small branches of the IMA. Those branches of the IMA and adjacent vein are easily exposed and isolated (Figure). They are then clipped and divided. The IMA pedicle was dissected and freed from the first to the sixth rib, and the distal end was anastomosed to the left anterior descending coronary artery (LAD) in all patients. The harvesting time and the amount of retrosternal bleeding during dissection of the IMA were measured in 10 patients and these measurements were compared with those obtained when ultrasonic aspiration was not used. Postoperative angiography of the IMA graft was done in all 20 patients. All 20 IMAs were usable. No macroscopic hematoma
or trauma caused by the ultrasonic aspirator were found in the graft. As shown in the Table, the time between initial skin incision and initiation of the cardiopulmonary bypass was 67.7 f 14.8 minutes (range, 45 to 100 minutes). This time was significantly shorter than that with the ordinary method (90.6 f 15.3 min). The amount of retrosternal bleeding was 176 ? 79 ml (range, 65 to 310 ml), which was also significantly less than occurs with the ordinary method (270 & 66 ml). Angiographic examination showed that all but one IMA graft was patent at 1 to 6 months postoperatively. No stenosis or wall irregularity was found in the patent grafts. The one nonpatent graft was from a 53-year-old woman. It was small and free flow was poor (30 mumin). An additional saphenous vein graft had been anastomosed to the same coronary artery (LAD) at the same time.
Comment Application of the ultrasonic aspirator is developing in the field of cardiovascular surgery [5, 61. As Mitsui and associates [5] reported, this instrument is useful in exposing an embedded coronary artery. In this case, the high-power output must be used to perform the myot-
From the Department of Thoracic and Cardiovascular Surgery, Osaka Medical College, Takatsuki, Japan. Accepted for publication Oct 10, 1986. Address reprint requests to Dr. Suma, Osaka Medical College, 2-7, Daigakucho, Takatsuki, Osaka 569, Japan.
676 Ann Thorac Surg 43:676-677, June 1987
Dissection of the IMA using ultrasonic aspirator. Small branches of the IMA and vein can be easily exposed. (IMA = internal mummay artery.)
677 How to Do It: Suma, Fukumoto, Takeuchi: Ultrasonic Aspirator in IMA Dissection
Comparison of Harvesting Times and Rates of Bleeding of Two Methods of Dissecting IMA
Method
Time (min) from Skin Incision to Start CPB (range)
Amount of Bleeding before CPB (ml) (range)
~
IMA without CUSA 90.6 ? 15.3” (n = 10) (66-120) IMA with CUSA 67.6 f 14.8” (n = 10) (45-100) SVG 38.5 2 10.1 (n = 10) (27-62)
270 f 66b (185-405) 176 f 79b (65-3101 116 2 68 (40-255)
$ ::::: IMA
= internal mammary artery; SVG = saphenous vein graft; CUSA Cavitron Ultrasonic Surgical Aspirator; CPB = cardiopulmonary bypass. =
omy. By contrast, low power is suitable for dissection of the IMA because it is surrounded by soft tissue. Small branches of the IMA and adjacent vein can be exposed easily without compromising them because of the gentle action of the ultrasonic aspirator. No critical trauma will occur in the IMA trunk if the ultrasonic aspirator is used with low-power vibration. Angiographic studies demonstrated that the IMAs were entirely smooth and regular.
No stenosis, which would result from wall trauma or hematoma, was evident. In addition, histologic examination of 3 randomly excised IMAs that were dissected by ultrasonic aspiration showed intact adventitia, media, and intima. Because of the good patency rate of the IMA grafts, shorter harvesting time, and less bleeding with our new method, we believe the ultrasonic aspirator to be useful for dissection of IMA.
References 1. Lytle BW, Cosgrove DM, Saltus GL, et al: Multivessel coronary revascularization without saphenous vein: Long-term results of bilateral internal mammary artery grafting. Ann Thorac Surg 36:540, 1983 2. Singh RN, Sosa JA, Green GE: Long-term fate of the internal mammary artery and saphenous vein grafts. J Thorac Cardiovasc Surg 86:359, 1983 3. Grondin CM, Campeau L, Lesperance J, et al: Comparison of late changes in internal mammary artery and saphenous vein grafts in two consecutive series of patients 10 years after operation. Circulation 7O:Suppl 1:208, 1984 4. Barner HB, Standeven JW, Reese J: Twelve-year experience with internal mammary artery for coronary artery bypass. J Thorac Cardiovasc Surg 90:668, 1985 5. Mitsui T, Onizuka M, Ijima H, et al: Ultrasonic aspiration in coronary artery surgery. Ann Thorac Surg 40:199, 1985 6. Kawamura T, Wada J, Kasagi Y, et al: Application of CUSA system to cardiac surgery-division of Kent bundle in WPW syndrome. Rinsh6 Ky6bu Geka 3:513, 1983
ap
Hisayoshi Suma, M.D., Hitoshi Fukumoto, M.D., and Atsuro Takeuchi, M.D. ABSTRACT The low-power ultrasonic aspirator was used for the dissection of the internal mammary artery (IMA) in 20 patients undergoing coronary artery bypass grafting. Harvesting time was shorter and the amount of bleeding was less than with the ordinary method. The short-term patency rate (1 to 6 months) for those IMA grafts was 95% (19 of 20 remained patent), These results have encouraged us to use the ultrasonic aspirator routinely for IMA dissection. The internal mammary artery (IMA) is considered superior for coronary artery bypass grafting because of its excellent long-term patency [l-41. Its dissection from the chest wall, however, is still a tedious job for the surgeon. We applied an ultrasonic aspirator for IMA dissection in 20 patients and found that harvesting time was shortened and bleeding was minimized compared with the ordinary method.
Technique After the sternum is split, the left side of the chest is retracted upward. We use electric cautery to make the retrosternal incision along the sternal edge in the usual fashion. Muscles and tendons attached to the rib are severed by the cautery, and fat and connective tissues are dissected by the ultrasonic aspirator. The ultrasonic aspirator is used with low-output vibration (usually 8 to 10%) and low-power suction (127 mm Hg) to avoid compromising small branches of the IMA. Those branches of the IMA and adjacent vein are easily exposed and isolated (Figure). They are then clipped and divided. The IMA pedicle was dissected and freed from the first to the sixth rib, and the distal end was anastomosed to the left anterior descending coronary artery (LAD) in all patients. The harvesting time and the amount of retrosternal bleeding during dissection of the IMA were measured in 10 patients and these measurements were compared with those obtained when ultrasonic aspiration was not used. Postoperative angiography of the IMA graft was done in all 20 patients. All 20 IMAs were usable. No macroscopic hematoma
or trauma caused by the ultrasonic aspirator were found in the graft. As shown in the Table, the time between initial skin incision and initiation of the cardiopulmonary bypass was 67.7 f 14.8 minutes (range, 45 to 100 minutes). This time was significantly shorter than that with the ordinary method (90.6 f 15.3 min). The amount of retrosternal bleeding was 176 ? 79 ml (range, 65 to 310 ml), which was also significantly less than occurs with the ordinary method (270 & 66 ml). Angiographic examination showed that all but one IMA graft was patent at 1 to 6 months postoperatively. No stenosis or wall irregularity was found in the patent grafts. The one nonpatent graft was from a 53-year-old woman. It was small and free flow was poor (30 mumin). An additional saphenous vein graft had been anastomosed to the same coronary artery (LAD) at the same time.
Comment Application of the ultrasonic aspirator is developing in the field of cardiovascular surgery [5, 61. As Mitsui and associates [5] reported, this instrument is useful in exposing an embedded coronary artery. In this case, the high-power output must be used to perform the myot-
From the Department of Thoracic and Cardiovascular Surgery, Osaka Medical College, Takatsuki, Japan. Accepted for publication Oct 10, 1986. Address reprint requests to Dr. Suma, Osaka Medical College, 2-7, Daigakucho, Takatsuki, Osaka 569, Japan.
676 Ann Thorac Surg 43:676-677, June 1987
Dissection of the IMA using ultrasonic aspirator. Small branches of the IMA and vein can be easily exposed. (IMA = internal mummay artery.)
677 How to Do It: Suma, Fukumoto, Takeuchi: Ultrasonic Aspirator in IMA Dissection
Comparison of Harvesting Times and Rates of Bleeding of Two Methods of Dissecting IMA
Method
Time (min) from Skin Incision to Start CPB (range)
Amount of Bleeding before CPB (ml) (range)
~
IMA without CUSA 90.6 ? 15.3” (n = 10) (66-120) IMA with CUSA 67.6 f 14.8” (n = 10) (45-100) SVG 38.5 2 10.1 (n = 10) (27-62)
270 f 66b (185-405) 176 f 79b (65-3101 116 2 68 (40-255)
$ ::::: IMA
= internal mammary artery; SVG = saphenous vein graft; CUSA Cavitron Ultrasonic Surgical Aspirator; CPB = cardiopulmonary bypass. =
omy. By contrast, low power is suitable for dissection of the IMA because it is surrounded by soft tissue. Small branches of the IMA and adjacent vein can be exposed easily without compromising them because of the gentle action of the ultrasonic aspirator. No critical trauma will occur in the IMA trunk if the ultrasonic aspirator is used with low-power vibration. Angiographic studies demonstrated that the IMAs were entirely smooth and regular.
No stenosis, which would result from wall trauma or hematoma, was evident. In addition, histologic examination of 3 randomly excised IMAs that were dissected by ultrasonic aspiration showed intact adventitia, media, and intima. Because of the good patency rate of the IMA grafts, shorter harvesting time, and less bleeding with our new method, we believe the ultrasonic aspirator to be useful for dissection of IMA.
References 1. Lytle BW, Cosgrove DM, Saltus GL, et al: Multivessel coronary revascularization without saphenous vein: Long-term results of bilateral internal mammary artery grafting. Ann Thorac Surg 36:540, 1983 2. Singh RN, Sosa JA, Green GE: Long-term fate of the internal mammary artery and saphenous vein grafts. J Thorac Cardiovasc Surg 86:359, 1983 3. Grondin CM, Campeau L, Lesperance J, et al: Comparison of late changes in internal mammary artery and saphenous vein grafts in two consecutive series of patients 10 years after operation. Circulation 7O:Suppl 1:208, 1984 4. Barner HB, Standeven JW, Reese J: Twelve-year experience with internal mammary artery for coronary artery bypass. J Thorac Cardiovasc Surg 90:668, 1985 5. Mitsui T, Onizuka M, Ijima H, et al: Ultrasonic aspiration in coronary artery surgery. Ann Thorac Surg 40:199, 1985 6. Kawamura T, Wada J, Kasagi Y, et al: Application of CUSA system to cardiac surgery-division of Kent bundle in WPW syndrome. Rinsh6 Ky6bu Geka 3:513, 1983