Ann Thorac Surg 2000;70:1431-1433
© 2000 The Society of Thoracic Surgeons
How to do it
Lower sternal splitting approach for off-pump coronary artery bypass grafting
Hiroshi Niinami, MD, PhDa,
Yasuo Takeuchi, MDa,
Yuji Suda, MDa,
Donald E. Ross, FRACSb
a Department of Cardiovascular Surgery, Tokyo Women’s Medical University, Daini Hospital, Tokyo, Japan
b Department of Cardiothoracic Surgery, Royal North Shore Hospital, Sydney, Australia
Address reprint requests to Dr Niinami, Department of Cardiovascular Surgery, Tokyo Women’s Medical University, Daini Hospital, 2-1-10 Nishiogu, Arakawa-ku, Tokyo 116–8567, Japan
e-mail: niinamca{at}dnh.twmu.ac.jp
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Abstract
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There are several ways to revascularize coronary arteries without cardiopulmonary bypass using a minimally invasive method. Currently, one of the most commonly used methods is minimally invasive direct coronary artery bypass (MIDCAB) through a left thoracotomy. Using this technique, however, only the left anterior descending and diagonal branch can be grafted. This article describes coronary revascularization of the left anterior descending artery or right coronary artery, or both, via a lower ministernotomy without a transverse cut, namely, the lower sternal splitting method. Through this approach, the left anterior descending, diagonal, and right coronary arteries can be revascularized using a single, minimally invasive approach without the risk of damaging the tissue around the intercostal space when the sternum is transversely divided.
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Introduction
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The most common minimally invasive approach for coronary artery bypass grafting (CABG) might be minimally invasive direct coronary artery bypass (MIDCAB) grafting through a left anterior small thoracotomy (LAST) [1]. The advantages of this procedure are small incision, off-pump technique, and no median sternotomy. However, this approach generally permits the exposure of only one coronary artery system, such as the left anterior descending (LAD) artery or the right coronary artery (RCA). Currently other approaches are used that allow the LAD and RCA systems to be grafted simultaneously with one small incision using the lower half ministernotomy technique [2–4]. These techniques usually require transverse division of the sternum, which can cause trauma to the thoracic wall, especially damage to the internal thoracic arteries (ITAs) when the ITA retractor is applied to the sternum. Furthermore, with these techniques there is a potential risk for pseudojoint of the sternum.
The lower sternal splitting approach provides the least trauma to the chest wall without compromising optimal exposure of both the anastomotic field and the ITAs.
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Technique
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The patient is placed in the supine position as for the standard full sternotomy. A midline skin incision is made from the fourth intercostal space to the xiphisternum (8 to 9 cm) (Fig 1). The lower half of the sternum is then divided with an oscillating saw up to the third intercostal space starting from the bottom, without dividing it into either a T or reversed J shape. A mammary retractor (Pecom, Inc, Independence, OH) is used to harvest the ITAs using the skeletonized technique. The ITAs can be exposed and harvested to the usual extent obtained with full sternotomy. During taking down the ITAs, care must be taken to avoid opening the pleura. When using the right gastroepiploic artery (GEA), a skin incision needs extending caudally for about 2 to 3 cm (Fig 1). In this case, the peritoneum is opened in the midline and the GEA is harvested by dividing the branches using ultrasonic dissection with a Harmonic Scalpel (Ethicon Endo-Surgery, Inc, Somerville, NJ) without using surgical clips or suture ligation and with adequate length ensured before grafting. The radial artery (RA), when used, is harvested from the left forearm simultaneously with the left ITA using ultrasonic dissection.
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Fig 1. Postoperative view of 2 patients who underwent minimally invasive direct coronary artery bypass. (Left) Healing incision, 8 cm long, using the bilateral internal thoracic arteries. (Right) Healing incision, 11 cm long, using left internal thoracic artery and gastroepiploicartery.
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After all conduits are harvested, a conventional spreader is positioned and gently opened, spreading only the lower part of the sternum. The pericardium is opened up to the aortic root. Heparin is given (1.5 mg/kg) to keep the activated clotting time around 300 seconds. The distal part of all in situ conduits are then ligated and divided. Intraluminal injection of diluted papaverine hydrochloride (0.2 mg/mL) is routinely used for the GEA and RA, as the vessels are prone to spasm upon surgical manipulation. The GEA pedicle graft is then routed anteriorly to the pylorus and the left liver lobe and positioned into the pericardial sac through a hole in the diaphragm anterior to the inferior vena cava (IVC). A coronary artery stabilizer (Octopus 2; Medtronic, Inc, Minneapolis, MN; or CAB Super-Slide Retractor, T Koros, Surgical Instruments Corp, Moorpark, CA) is set on the spreader. A 1 Vicryl suture with a big tapered needle (J359H; Ethicon, Inc, Cincinnati, OH) is placed into the pericardium near the left lower pulmonary vein. This suture is gently pulled upward and secured to the surgical drape with the hemostat on the left side, bringing up the LAD artery to the field [5]. The stabilizer is positioned and fixed on the LAD (Fig 2).
The anastomotic site of the LAD artery is chosen, and two 4-0 Prolene sutures (Ethicon, Inc, Cincinnati, OH) are passed around proximally and distally to the anastomotic site of the coronary artery using snares with a Teflon (Impra, Inc, Tempe, AZ) felt pledget. The LAD is occluded briefly by means of a snaring proximal suture to evaluate the ischemic tolerance. The LAD is opened longitudinally and the proximal suture is snared gently for hemostasis. Snaring of the distal suture is not always performed unless back bleeding is difficult to control. The LITA-LAD anastomosis is carried out using the 8-0 Prolene single parachute technique. For anastomosis on the main RCA, two looping heavy silk sutures surround the anastomotic site of the coronary artery proximally and distally. The RCA is occluded briefly by means of a looping proximal suture to evaluate ischemic tolerance, especially rhythm. For the main RCA exposure, the stabilizer is not required. By pulling the proximal heavy silk suture cranially, the RCA is opened longitudinally and the RITA-RCA or GEA-RCA anastomosis is then carried out using a 7-0 or 8-0 Prolene single running suture.
For the anastomosis on the right posterior descending artery (PDA), another 1 Vicryl suture with a big tapered needle is placed on the diaphragmatic surface of the pericardium, a little deeper from the IVC [5]. This suture is pulled caudally to bring up the PDA to the field. The acute margin of the heart is then displaced cranially by the Octopus stabilizer to provide good exposure of the inferior wall. The anastomotic site of the PDA is chosen and prepared in the same way as for the LAD. The GEA-PDA or RA-PDA anastomosis is performed with a running 8-0 Prolene suture. When the RA graft is used, a Y graft is constructed with the ITA, after the distal anastomosis, with a running 8-0 Prolene suture. Once the anastomosis is complete, the graft flow is tested using a handheld transit-time ultrasonic flow probe (Transonic Systems, Inc, Ithaca, NY) to assist in the detection of technical problems with the anastomosis. Heparin is not reversed or a half dose of protamine is given at the end of the procedure. After insertion of two 8-mm drains into the pericardial cavity and the substernal space, the lower sternotomy is closed with 3 or 4 sternal wires.
From November 1999 to December 1999, 6 patients were operated upon for primary myocardial revascularization under the beating heart condition using the lower sternal splitting approach. Preoperatively, in all patients, the size of the LITA and GEA was evaluated by angiography during cardiac catheterization. The characteristics of the patients are listed in Table 1. Neither hemodynamic changes nor transient electrocardiographic S-T segment changes occurred during the operation. No patients had perioperative myocardial infarction or required blood transfusion. All patients have had an excellent recovery, were transferred from the intensive care unit within 24 hours, and had a shortened hospital stay. During admission, postoperative angiography was performed in all patients and demonstrated graft patency. In 1 patient, whose sternum was closed by titanium wires, the sternum was evaluated postoperatively by magnetic resonance imaging. No evidence of sternal fracture or damage of the tissue was found around the split end of the sternum.
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Comment
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Several satisfactory methods now exist to approach the coronary arteries during off-pump CABG through smaller incisions [1–4, 6]. However, access to both the RCA and the LAD requires two incisions if the anterior small thoracotomy approach is utilized, frequently resulting in incisions whose total length is almost the same or greater than that of a full sternotomy [6]. In contrast, the lower ministernotomy approach provides ease of access to both vessels through a limited incision and allows ITA harvest under direct vision. Moreover, the incision can be easily and rapidly extended to a full sternotomy if technical difficulties arise. For these reasons, it remains the method of choice for MIDCAB [2–4].
Lower ministernotomy, in general, requires partial (reversed J shape) or total (T shape) transverse dissection of the sternum at the level of the third intercostal space, depending upon the number of ITAs utilized. However, the possible risk of injuring the ITAs around the third intercostal space when the lower hemisternum is elevated by the mammary retractor must be considered. Furthermore, sternal nonunion could occur at this point during the healing process and this may cause pseudojoint formation. With the use of our technique, theoretically these complications should not occur. Also, in the case of immediate conversion to full sternotomy, the sternal retractor can be applied without sternal instability.
One of the concerns in the use of this maneuver might be fracture of the sternum and laceration of the surrounding tissue by forcing stress on the cranial end of the longitudinal dissected sternum. We have observed the sternum around the third intercostal space by magnetic resonance imaging and found no evidence of serious bone fracture or tissue laceration. Surprisingly, patients who received the lower sternal splitting approach showed much less pain compared with those who received conventional full sternotomy or LAST. In terms of postoperative recovery, all 6 patients in this series had an excellent recovery in spite of their advanced age.
We believe this approach is really less invasive and can be applied to any patient who requires grafting of the LAD and RCA systems. The main advantage of this approach may be the reduced pain and quick recovery. We think the reasons for the reduction in pain are that the intercostal space is not dissected and the manubrium remains intact, which produces less pain when using the arms. This approach can be advantageous, especially in women, elderly patients, and diabetic patients.
In conclusion, the lower sternal splitting approach can be an alternative approach for MIDCAB in patients with LAD and RCA disease.
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References
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Calafiore A.M., Di Giammarco G., Teodori G., et al. Midterm results after minimally invasive coronary surgery (LAST operation). J Thorac Cardiovasc Surg 1998;115:763-771.[Abstract/Free Full Text]
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Arom K.V., Emery R.W., Nicoloff D.M. Mini-sternotomy for coronary artery bypass grafting. Ann Thorac Surg 1996;61:1271-1272.[Abstract/Free Full Text]
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Doty D.B., DiRusso G.B., Doty J.R. Full-spectrum cardiac surgery through a minimal incision. Ann Thorac Surg 1998;65:573-577.[Abstract/Free Full Text]
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Grandjean J.G., Canosa C., Mariani M.A., Boonstra P.W. Reversed-J inferior sternotomy for beating heart coronary surgery. Ann Thorac Surg 1999;67:1505-1506.[Abstract/Free Full Text]
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Niinami H, Koyanagi H, Brady PW, Ross DE. The heart string: a simple, inexpensive exposure of the heart during coronary artery operations. Ann Thorac Surg 2000;69:1280–1.
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Voutilainen S., Verkkala K., Jarvinen A., et al. Minimally invasive coronary artery bypass grafting using the right gastroepiploic artery. Ann Thorac Surg 1988;65:444-448.[Abstract/Free Full Text]
Accepted for publication April 5, 2000.
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Abstract
Introduction
