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Minimally invasive direct coronary artery bypass (MIDCAB) utilizes a small (4-5 cm) left anterior thoracotomy incision for direct visualization of the diseased coronary artery on the anterior wall of the left ventricle without the use of cardiopulmonary bypass (CPB). Since its first description in 1967 by Kolesov, many variations have been described including single left internal mammary artery (LIMA) to left anterior descending (LAD) coronary bypass, multivessel (including complete) revascularization, robotics and video-based endoscopic techniques for IMA harvest and revascularization. Finally, hybrid approaches for revascularization (ie, surgical bypass of the LAD coronary artery followed by percutaneous coronary intervention (PCI) of non-LAD targets) utilize the same approach for complex patients needing coronary revascularization.
In this article, we will describe the basics of the MIDCAB surgery, emphasising both the left anterior thoracotomy for the harvest of LIMA and direct anastomosis on a beating heart without CPB. This procedure is done on a 72-year-old patient who had significant long LAD stenosis and presented with effort angina. Following a multidisciplinary “heart team” conference, he underwent a successful MIDCAB and was discharged home on postoperative day 4.
Ischemic heart disease (IHD) is a major cause of death and disability in developed countries. Although there is persistent decline in mortality rates from coronary artery disease worldwide over the past four decades, IHD is accountable for about one-third or more of all deaths in individuals over age 35. It has been estimated that nearly one-half of all middle-aged men and one-third of middle-aged women in the United States will develop some manifestation of IHD.
Coronary artery bypass grafting (CABG) is among the most important surgical procedures in the history of medicine. Since its initial development more than a century ago by Alexis Carrel, which resulted in his Nobel prize in physiology in 1912, several modifications of this important surgery were done. Notably, in the era of minimally invasive surgery where more and more innovations are being developed, the establishment of minimally invasive direct coronary artery revascularization deserves special attention.
We present an active 72-year-old male in overall good condition who had no significant comorbidities. Four months prior to his presentation to our team, he experienced chest discomfort and palpitation during exercise at the gym where he used to train 3-4 times a week.
Following presentation to his Primary care, he was sent for exercise tolerance test. Following the test, he again experienced chest pain and discomfort. Physical examination was not contributory at that time.
Electrocardiogram showed frequent premature ventricular contractions and he was referred to exercise tolerance test. Stress test demonstrated ST segment depressions in the inferior electrocardiographic leads including V4-V6, and 2 mm ST elevations in aVR and aVL. Nuclear imaging at that time demonstrated large, moderate to severe reversible defects involving the anterior, septal, and apical walls. Following the test, he was sent to the emergency department to rule out acute myocardial infarction. Left cardiac catheterization demonstrated a right-dominant coronary arterial system with 1-vessel coronary artery disease (left main- patent, left anterior descending showed diffuse long segment of 95% stenosis in the proximal part and 80% diffuse disease with TIMI 2 flow in the mid LAD territory). Circumflex and right coronary artery had normal fluoroscopic morphology with non-significant stenosis. Echocardiography showed preserved ejection fraction (70%) with no diastolic dysfunction and no valvular disease. The patient presented in a multidisciplinary “heart team” discussion and expert consensus elected to offer the patient MIDCAB LIMA-LAD revascularization.
Left untreated high grade stenosis in the proximal coronary artery may progress and cause complete obstruction leading to devastating ischemic heart disease sequelae.
The gold standard for complete coronary revascularization is coronary artery bypass grafting, especially the use of arterial bypass with left internal mammary artery (LIMA) to left anterior descending artery (LAD). This has been proved in multiple meta-analyses to relieve symptoms, improve survival, and decrease the need for further revascularization besides decrease recurrence of adverse cardiac events.1,2 The alternative in patients who need revascularization is PCI.
The use of cardioplegia with CPB has resulted in superior clinical results by allowing the surgeon to work in arrested heart, thus maximizing exposure that permits precise complex revascularization. The downside of using cardioplegia is the need for aortic instrumentation (ie, cannulation and decannulation), initiation and termination of CPB with circulatory arrest, and hypothermia and anticoagulation that prepare the patient for intense inflammatory mediated response and hemodynamic changes.
On one hand, the use of median sternotomy for exposure yields excellent visualization of the mediastinum and the heart, but on the other hand, it exposes the patient to pain and infection risks that can be devastating.
As the alternative of coronary artery bypass surgery, PCI is limited in multiple occlusion sites and has high reintervention rates due to in-stent restenosis, especially in diabetic subjects.
In 1967, Kolessov first described the procedure of grafting the left anterior descending artery using LIMA on a beating heart through left anterior thoracotomy.3 This was the first description of the procedure as it is used today, though many years elapsed until it was known and accepted among cardiac surgeons.4 Alternative approaches for more complete revascularization can utilize this limited thoracotomy incision for the use of a free segment of right IMA, radial artery, saphenous vein, or inferior epigastric artery Y’d or T’d to accessible coronary arteries (diagonal or circumflex branches).5
Patient selection is of great importance in MIDCAB surgery. The patient should be selected carefully with the ideal candidate having severe stenosis in the anterior coronary vessels - mainly the proximal portion of the left anterior descending artery with the distal vessel relatively free from diffuse disease and calcification.6,7 Other patients that should undergo MIDCAB surgery are those with multivessel disease in whom complete surgical revascularization is contraindicated (given structural aortic disease that prohibit cannulation or anastomosis), sternotomy is contraindicated (given prior surgery or mediastinal condition, such as s/p sternal wound infection, mediastinitis, or mediastinal radiation), or cardiopulmonary bypass is contraindicated (given multiple comorbidities or high risk conditions such as calcified ascending aorta or diffuse atherosclerosis).8 MIDCAB surgery is also a good choice when PCI cannot be performed due to a contrast allergy or technical difficulties such as excessive stenotic length, angulation, tortuosity, complex lesions, total vessel occlusion, and diabetes.9 Compared to Sternotomy with CPB, MIDCAB patients experience less postoperative pain, have shorter convalescence periods, need fewer blood transfusions, and exhibit less atrial fibrillation.10,11
However, MIDCAB is a technical demanding procedure given the limited exposure and the beating heart. Specific disadvantages include: the exposure of the anterior coronary vessels as the revascularization of other vessels, such as the posterior descending artery and right coronary artery, require the manipulation of the heart; the difficulty of complete revascularization (residual CAD should be treated with PC or hybrid approach with PCI added to the other occluded vessels should be considered); the technical challenges of LIMA/RIMA skeletonized harvesting; the possibility that intramyocardial vessels (< 1.5mm) and a diffuse, calcified target require complex and extensive endarterectomy; the need for single-lung ventilation; the use of a double-lumen endotracheal tube or bronchial-blocker with bronchoscopy to confirm correct placement; and the need to treat for postoperative thoracotomy pain with epidural, intercostal nerve cryoablation, etc. If possible, myocardial stabilization devices (e.g. Octopus device) should be used to improve the accuracy and ease of distal anastomosis on a beating heart.
There are few contraindications regarding this procedure. For obese patients, LIMA harvest is feasible, but the lateral pressure exerted on the wound with the retractor might cause necrosis and prompt infection in the edges of the wound. Similarly, females with large breast tissue also have increased risk for wound necrosis and infection (relative). Prior thoracotomy and extensive chest adhesions are relative contraindications as they limit the exposure and thus decrease the benefit of a minimally invasive approach. Contraindications also include intramyocardial (relative), calcified small size (< 1.5mm) lesions in the LAD in the preoperative CT coronography or angiography. Left subclavian artery stenosis or occlusion limits the use of LIMA. Certain moribund patients should not undergo this procedure, specifically those in whom cardiogenic shock or ischemia is too severe to permit snaring of the vessels or who cannot tolerate single lung ventilation (eg severe COPD with emphysema) or the decrease in heart rate / blood pressure that is induced by anesthesia to assist the surgeon for the endarterectomy and anastomosis.12
CAD remains the leading cause of death in North America. Besides primary prevention, optimal medical therapy and percutaneous or surgical revascularization showed to improve survival and quality of life.13,14 The use of LIMA as a graft showed substantial survival advantage in CABG when anastomosed to the LAD. Studies showed 10 year graft patency rates that exceed 95%.15,16
In most institutes, patients who need CPB and median sternotomy must undergo 24 hour monitoring in an intensive care unit followed by a median hospital stay of 6-7 days.17 The alternative for CABG in less complicated cases or limited coronary vascular disease is PCI, which has the benefit of a same-day discharge procedure, minimal postprocedural observation with good outcomes due to angiography based stenting. However, despite the reduced invasiveness of PCI, the major disadvantage is the need for repeated revascularization despite a newer generation of drug-eluting stents (i.e, DES). Hybrid approaches that combine the benefits of PCI and CABG are recognized as feasible alternatives in well selected patients.
Several recent studies compare the gold standard of revascularization, CABG with CPB via full sternotomy, and MID CABG or hybrid procedures (MIDCAB+PCI). All these studies demonstrate equal survival and long term outcome of minimally invasive procedures compared to full sternotomy. In the case of hybrid approaches, more revascularization was used as expected.17,18,19,20,21 An additional benefit of MIDCAB or hybrid minimally invasive approaches is the use of off-pump techniques instead of on-pump coronary artery revascularization. In 2015, two separate meta-analyses arrived at the same conclusion that off-pump surgery can significantly reduce the risk for stroke rates specifically in high risk patients.22,23 Additional studies showed that patients with LIMA-to-LAD grafting return to normal daily function quickly and get discharged from hospital on postoperative day 4.24,25 Graft patency after single vessel small thoracotomy showed 100% patency in 6 months in two separate studies as well.26,27
Patient selection is prudent for this highly demanding procedure. Three factors should be considered when choosing the right revascularization procedure to the right patients: 1) angiographic factors, 2) patient related factors, and 3) clinical factors.
High grade single vessel long stenosis and other vessel anatomic limiting factors for PCI such as tortuosity, angulation, etc, make MIDCAB a good alternative to PCI. Multivessel disease should be treated surgically unless the patient cannot tolerate CPB due to an anatomic aortic condition or his/her status as described earlier in the special considerations section. Prior sternotomy, severe mediastinal infection, or radiation therapy gives this approach an advantage in the appropriate patient. Finally, the need for single lung ventilation, severe cardiogenic shock, and poor myocardial perfusion (which limits the relative ischemic time while snaring the myocardium) limits the use of this technique. We recommend using the fifth ICS rather than the fourth to allow better utilization of the LIMA harvest as well as better mid-LAD exposure.
In conclusion, beating heart coronary artery bypass grafting is a technically challenging procedure. Adding the limited exposure via left anterior thoracotomy makes the procedure even more challenging. Advancements in technology, such as MIDCAB retractors for LIMA harvest and heart stabilizers, make the procedure feasible. Comprehensive understanding of the LAD anatomy is vital for successful performance of the anastomosis. As always, patient selection should be optimal, and the surgeon should feel competent enough to perform this kind of operation.
No special equipment was used.
The authors have no relevant disclosures.
The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.
- Lytle BW, Blackstone EH, Loop FD, et al. Two internal thoracic artery grafts are better than one. J Thorac Cardiovasc Surg. 1999;117(5):855-872. doi:10.1016/S0022-5223(99)70365-X.
- Aldea GS, Bakaeen FG, Pal J, et al. The Society of Thoracic Surgeons Clinical Practice Guidelines on Arterial Conduits for Coronary Artery Bypass Grafting. Ann Thorac Surg. 2016;101(2):801-809. doi:10.1016/j.athoracsur.2015.09.100.
- Kolessov VI. Mammary artery coronary artery anastomosis as method of treatment of angina pectoris. J Thorac Cardiovasc Surg. 1967;54(4):535-544.
- Benetti FJ, Ballester C. Use of thoracoscopy and a minimal thoracotomy, in mammary-coronary bypass to left anterior descending artery, without extracorporeal circulation. Experience in 2 cases. J Cardiovasc Surg (Torino). 1995;36(2):159-161.
- Cohn WE, Suen HC, Weintraub RM, Johnson RG. The "H" graft: an alternative approach for performing minimally invasive direct coronary artery bypass. J Thorac Cardiovasc Surg. 1998;115(1):148-151.
- Angelini GD, Wilde P, Salerno TA, Bosco G, Calfiore AM. Integrated left small thoracotomy and angioplasty for multivessel coronary artery revascularization. Lancet. 1996;347(9003):757-758. doi:10.1016/S0140-6736(96)90107-5.
- Azoury FM, Gillinov AM, Lytle BW, Smedira NG, Sabik JF. Off-pump reoperative coronary artery bypass grafting by thoracotomy: patient selection and operative technique. Ann Thorac Surg. 2001;71(6):1959-1963. doi:10.1016/S0003-4975(01)02617-0.
- Ng PC, Chua AN, Swanson MS, Koutlas TC, Chitwood WR Jr, Elbeery JR. Anterior thoracotomy wound complications in minimally invasive direct coronary artery bypass. Ann Thorac Surg. 2000;69(5):1338-1340. doi:10.1016/S0003-4975(00)01222-4.
- Calafiore AM, Giammarco GD, Teodori G, et al. Left anterior descending coronary artery grafting via left anterior small thoracotomy without cardiopulmonary bypass. Ann Thorac Surg. 1996;61(6):1658-1665. doi:10.1016/0003-4975(96)00187-7.
- Subramanian VA. Less invasive arterial CABG on a beating heart. Ann Thorac Surg. 1997;63(6)(suppl 1):S68-S71. doi:10.1016/S0003-4975(97)00417-7.
- Srivastava SP, Patel KN, Skantharaja R, Barrera R, Nanayakkara D, Srivastava V. Off-pump complete revascularization through a left lateral thoracotomy (ThoraCAB): the first 200 cases. Ann Thorac Surg. 2003;76(1):46-49. doi:10.1016/S0003-4975(03)00034-1.
- Guida MC, Pecora G, Bacalao A, Muñoz G, Mendoza P, Rodríguez L. Multivessel revascularization on the beating heart by anterolateral left thoracotomy. Ann Thorac Surg. 2006;81(6):2142-2146. doi:10.1016/j.athoracsur.2006.01.054.
- Mohr FW, Morice MC, Kappetein AP, et al. Coronary artery bypass graft surgery versus percutaneous coronary intervention in patients with three-vessel disease and left main coronary disease: 5-year follow-up of the randomised, clinical SYNTAX trial. Lancet. 2013;381(9867):629-638. doi:10.1016/S0140-6736(13)60141-5.
- Abdallah MS, Wang K, Magnuson EA, et al. Quality of life after PCI vs CABG among patients with diabetes and multivessel coronary artery disease: a randomized clinical trial. JAMA. 2013;310(15):1581-1590. doi:10.1001/jama.2013.279208.
- Grondin CM, Campeau L, Lespérance 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(3 pt 2):I208-I212.
- Fitzgibbon GM, Kafka HP, Leach AJ, Keon WJ, Hooper GD, Burton JR. Coronary bypass graft fate and patient outcome: angiographic follow-up of 5,065 grafts related to survival and reoperation in 1,388 patients during 25 years. J Am Coll Cardiol. 1996;28(3):616-626. doi:10.1016/0735-1097(96)00206-9.
- Blazek S, Rossbach C, Borger MA, et al. Comparison of sirolimus-eluting stenting with minimally invasive bypass surgery for stenosis of the left anterior descending coronary artery: 7-year follow-up of a randomized trial. JACC Cardiovasc Interv. 2015;8(1 pt A):30-38. doi:10.1016/j.jcin.2014.08.006.
- Deppe AC, Liakopoulos OJ, Kuhn EW, et al. Minimally invasive direct coronary bypass grafting versus percutaneous coronary intervention for single-vessel disease: a meta-analysis of 2885 patients. Eur J Cardiothorac Surg. 2015;47(3):397-406. doi:10.1093/ejcts/ezu285.
- Harskamp RE, Vassiliades TA, Mehta RH, et al. Comparative effectiveness of hybrid coronary revascularization vs coronary artery bypass grafting. J Am Coll Surg. 2015;221(2):326-334.e1. doi:10.1016/j.jamcollsurg.2015.03.012.
- Raja SG, Benedetto U, Alkizwini E, Gupta S, Amrani M; Harefield Cardiac Outcomes Research Group. Propensity score adjusted comparison of MIDCAB versus full sternotomy left anterior descending artery revascularization. Innovations (Phila). 2015;10(3):174-178. doi:10.1097/IMI.0000000000000162.
- Rosenblum JM, Harskamp RE, Hoedemaker N, et al. Hybrid coronary revascularization versus coronary artery bypass surgery with bilateral or single internal mammary artery grafts. J Thorac Cardiovasc Surg. 2016;151(4):1081-1089. doi:10.1016/j.jtcvs.2015.10.061.
- Kowalewski M, Pawliszak W, Malvindi PG, et al. Off-pump coronary artery bypass grafting improves short-term outcomes in high-risk patients compared with on-pump coronary artery bypass grafting: meta-analysis. J Thorac Cardiovasc Surg. 2016;151(1):60-77.e58. doi:10.1016/j.jtcvs.2015.08.042.
- Altarabsheh SE, Deo SV, Rababa'h AM, et al. Off-pump coronary artery bypass reduces early stroke in octogenarians: a meta-analysis of 18,000 patients. Ann Thorac Surg. 2015;99(5):1568-1575. doi:10.1016/j.athoracsur.2014.12.057.
- Lapierre H, Chan V, Sohmer B, Mehsana TG, Ruel M. Minimally invasive coronary artery bypass grafting via a small thoracotomy versus off-pump: a case-matched study. Eur J Cardiothorac Surg. 2011;40(4):804-810. doi:10.1016/j.ejcts.2011.01.066.
- McGinn JT Jr, Usman S, Lapierre H, Pothula VR, Mesana TG, Ruel M. Minimally invasive coronary artery bypass grafting: dual-center experience in 450 consecutive patients. Circulation. 2009;120(11)(suppl 1):S78-S84. doi:10.1161/CIRCULATIONAHA.108.840041.
- Ruel M, Shariff MA, Lapierre H, et al. Results of the minimally invasive coronary artery bypass grafting angiographic patency study. J Thorac Cardiovasc Surg. 2014;147(1):203-208. doi:10.1016/j.jtcvs.2013.09.016.
- Toeg H, Al-Atassi T, Labinaz M, Le May M, Ruel M. Hybrid approach for coronary artery revascularization: where do we stand? Curr Opin Cardiol. 2014;29(6):534-541. doi:10.1097/HCO.0000000000000112.
- The patient is kept on his preoperative antiplatelet therapy. Standard premedication is given at the preoperative holding area. Invasive (arterial line, central venous line, transesophageal echocardiography) and noninvasive (pulse oximetry, Foley) monitoring modalities are the same as for standard coronary artery bypass graft surgery. A Swan Ganz catheter is not used as a routine. Temperature monitoring is of high importunacy and is monitored by Foley catheter probes. If needed, epidural or paravertebral block (T2-T3) can be done prior to induction.
- The procedure is facilitated by one lung ventilation and the patient is intubated with double-lumen endotracheal tube. Bronchial blocker is a reasonable alternative as long as the blocker provides adequate lung isolation by bronchoscopy.
- Anticoagulation during the procedure is achieved with intravenous heparin (goal activated clotting time >300 seconds). At the end of the procedure, heparin is half- reversed with protamine. A cell saver is used to collect and recycle shed mediastinal blood.
- The patient placed supine with his left arm tucked. Longitudinal roll is placed under the left chest. Alternatively, slight tilt (15°) horizontally to the right will assist with exposure. External defibrillator pads are placed in the left infrascapular region and the right subclavicular region.
- The patient is prepped including the lower extremities (in case of conversion and need for vein harvest) and both groins and the sternum are exposed below the drapes.
- Perform Left 3 Inch Mini Thoracotomy in the 5th Intercostal Space
- A 5cm skin incision is made usually in the 5th intercostal space (sometimes 6th space) just below the mammary fold. The incision is started at mid-clavicular line and extended medially.
- Some authors prefer the 4th intercostal space; however we found that the 5th space allows better exposure of the mid-portion of the LAD and wider anastomosis target. It also enables better exposure to the mammary artery providing longer harvested artery.
- Extreme caution should be practiced to avoid injury to the LIMA with medial extension of the incision. The skin incision is usually smaller than the intercostal dissection.
- The left lung is isolated by the anesthesiologist, the pleural space is opened, and a LIMA-lift retractor (Medtronic INC, Minneapolis, MN) is placed in the wound.
- A rul-tract retractor based on the left rails of the table with a hook is attached to the superior blade of the LIMA-lift, allowing optimal visualization of the medial portion of the sternum for better LIMA harvest.
- The LIMA-lift retractor is exchanged with a dedicated MIDCAB retractor.
- The anterior pericardium is opened over the LAD. The pericardial incision is carried down to the apex of the heart. Pericardial stay sutures are placed on both edges of the incision, as needed.
- Assess Left Anterior Descending Coronary Artery Quality and Size
- The LAD is identified parallel to the sternum to the right of the apex.
- The Diagonal artery (which is sometime mistakenly identified as the LAD) is often seen coursing parallel to the incision and toward the apex.
- Identify Lateral Mammary Vein
- Divide Fascia
- The endothoracic fascia is identified and dissected.
- The fat pad overlying the LIMA is cleaned.
- The LIMA is dissected, skeletonized to achieve optimal length for LAD anastomosis.
- The LIMA is dissected proximally to its origin from the left subclavian vessels (usually up to 1st intercostal space), whereas the caudal extent of LIMA dissection is usually at the level of the 6th intercostal space proximal to the bifurcation between the pericardio-phrenic and the superior epigastric artery.
- Once the patient is heparinized, the artery is ligated and divided distally.
- 5cc of papaverine (1mg/ml) solution are sprayed over the mammary to allow pharmacologic dilation of the conduit.
- A bull-dog clamp is placed at the distal end of the LIMA to allow gentle distention under physiological pressure.
- Tack Mammary to Edge of Incision
- Prepare Mammary
- Proximal Occlusion of Left Anterior Descending Coronary Artery
- Stabilize LAD
- We use a pressure stabilizer attached to the MIDCAB retractor and placed parallel to the LAD and pushed down gently against the septum.
- The LIMA is cleaned and prepared in the usual fashion and beveled at its distal part.
- The target LAD area is chosen and proximal snare is placed only proximally to the chosen arteriotomy site.
- The surgeon’s assistant uses a Blower-mister device to assist with exposure.
- 1cm arteriotomy is carefully done.
- An appropriately sized intra-coronary shunt is used to avoid ischemic time during the anastomosis and minimize blood loss.
- The bulldog clamp on the LIMA is released.
- Flow is checked with Flow-meter.
- Punctual arterial bleeds repaired.
- After revascularization, heparin is reversed with Protamine.
- The pericardial sac is loosely re-approximated with 2-0 Vicryl sutures.
- Care should be taken at this point not to exert traction on the LIMA.
- An intercostal rib block (rib 4-6) is usually done with 0.5% bupivacaine solution; alternatively a intercostal nerve cryoablation may be performed.
- Straight chest tube placed below the incision and secured.
- The ribs are re-approximated and the lung is allowed to re-inflate.
- The wound is closed in layers in the usual manner.
- Postoperative care
- The goals of post-operative care are early mobilization and pain control.
- Most of the patients are extubated in the operating room and transferred to the Intensive care unit for overnight observation.
- Antiplatelet therapy is continued, and pain is controlled with the combination of NSAIDs Paracetamol and minimal Opiates as needed.
- Intravenous fluids are restricted and the patients are advanced to clear and then regular diet usually on postoperative day 1st and 2 respectively.
- Early ambulation is crucial and the arterial line, central line, and chest tube are usually taken out in post-operative day 1.
- Patients are discharged home on postoperative day 4 or 5 ambulating with oral pain control.
My name is Marco Zenati. I’m a cardiac surgeon at VA Boston. Today we're going to perform a minimally invasive coronary bypass on a 72-year-old male. He's a very healthy and active gentleman with no other medical comorbidities. And he - about 6 months ago - during his workouts - he works out actually 6 days a week, and he alternates treadmill with weight lifting - and he found out that he had to stop, and he had some chest pressure during exercise. It will go away after he would cease the activity, so he's sought medical attention. He underwent the stress test which was positive with EKG changes - he had ST depression in anterior leads. And he also had a nuclear medicine study - Italian test - it was both positive, so that triggered a left heart catheterization, which demonstrated a high grade lesion of the proximal left anterior descending coronary artery without any other disease and the other vessels.
The cardiologist determined that this lesion was not amenable to angioplasty or stenting, so it was referred to us for a minimally invasive bypass with a mammary to the left anterior descending coronary artery. And we perform this procedure through a 3-inch-mini thoracotomy on the left side without the use of challah machine on the beating heart. The patient is an excellent candidate for this procedure; body habitus is very favorable. He's in good shape. He’s thin, and he has wide interspaces. So we believe he is an excellent candidate for this operation.
So the minimally invasive coronary bypass procedure is performed through a 3- inch-mini thoracotomy on the left side. It starts with a modified and aesthetic approach using left side of the lumen tube that allows us to deflate the left lung and work in the left pleural space. The incision is usually in the fifth intercostal space and is followed by a pericardiotomy and exposure of the target to make sure the lad is acceptable quality and it's not intramyocardial. Once that is assessed, we move to the harvest of the mammary artery, which is done using a special device we call the LIMA Lift that provides exposure of the mammary artery.
Once the harvest is completed, we use a stabilization device and we perform the anastomosis between a mammary- to the LAD on the beating heart, using intracoronary shunt. Following the procedure, we are very careful about providing the best possible analgesia. The options are in an epidural approach or a intracostal cryoablation. Our protocol is using a cryoprobe for 2 minutes at the level of the 5th intercostal space where we do the thoracotomy and then two spaces above and two spaces below for a total of 5 applications and then we supplement with intercostal nerve block with the novocain. And the patient is usually excavated in the operating room. Average duration of procedures between 90 minutes and 2 hours - skin to skin from the surgical part.
We have a standby system here available. The pump is in the room but is not being primed - will take us a few minutes to prime it, and this procedure is done off pump. This provides additional layers of safety. This patient is 72-year-old with a single vessel coronary disease involving the left anterior descending coronary artery and a small diagonal branch, and this lesion was found not to be amenable to angioplasty, and it was referred for a minimally invasive bypass. Our plan is to perform a mammary artery to the left anterior descending coronary artery bypass and possibly also a composite graph to the diagonal. Decision would be made intraoperatively based on the size.
So the patient is being - is supine - as you can see. We prepped legs in case we need to have a segment of vein. And the positioning is with the left side of the chest slightly bumped and the arms are tucked on the side. The other thing to note is we have placed them - they not visible under the drapes - some defibrillating pads. There’s adhesive on the chest, in case of the need for defibrillation. We won't be able to access using the internal pads, we use the external pads, so that's actually an important point to know when we prep this patient because we don't routinely use these external pads for sternotomy cases.
So, Dr. Zorca, are we currently doing both lung ventilation or single lung? So the left lung has been deflated and the saturation is fine. So looks like the patient is tolerating this well. So we already done our safety pause, and the antibiotic is in the patient. Perfect, and we have blood available in the room. So the next step is to perform the skin incision.
So we have a marking pen. The tip of the xiphoid, and we're marking the coastal margins here, and the jugular notch will be here. So we identified the nipple and based on the size of the heart, which we evaluated on the chest x-ray, we would like to make an incision about 3 inch, and we’ll center the incision about 2/3 medial and 1/3 lateral to the nipple. Something like this. Okay so. I’ll take a knife. Okay, incision. You want to do your rakes to lift the skin? You have rakes? Please. Do you have a Weitlaner? Yeah, there's not much subcutaneous tissue in this patient. Okay, so we're going to enter - Roby, it's either fifth or sixth space.
We have to make a decision here. Most likely I will try to go in the 5th space so we go between - separate the belly of the pectoralis muscle. Okay, so we're in the pleural space. The left lung looks like it's nicely deflated, thank you, Susanna. The incision is done and we have opened the intercostal space, so we now use the MIDCAB retractor. The operation goes by the acronym MIDCAB which stands for Minimally Invasive Direct Coronary Artery Bypass, and this is a MIDCAB retractor - it’s designed for this procedure. Now mount the blades.
So this next phase is confirming the targets and we’re going to open the pericardium - goes like this - open the pericardium, and then finalize our revascularization plan. Maybe the table up a little bit, please. Thank you.
So what I'm doing right now, I'm mobilizing the fat pad that is laying over the heart and as I do that, you will start seeing pericardium and underneath the pericardium you’ll see the heart. So we’re going to mobilize more of this pericardial fat on the side, and we’ll use this eventually for - to close the pericardium. Again, the Bovie I’m using is on a very low setting because we're operating in proximity to the heart, so there is the potential of triggering some myritneyas, so we have to be cognizant of that. Moving this laterally. So I keep peeling this - then I gently use this retractor. Try to minimize the muscle incision and… So we’re… Okay, so I’ll take a tonsil please. So we're ready to open the pericardium and assess our target if - if I have done a good job, the left anterior descending coronary artery, which is our main target, will lie right in the middle of my incision.
We grab the pericardium with this instrument. Ory, please hold it for us. And wallah. This is the left anterior descending coronary artery. So I think we we we we - made a good choice in terms of the location of this thoracotomy in relationship to the target. That is a very important component of this procedure. If this patient had a cardiomegaly and the costal- the heart margin would have been more lateral - this incision would have been more lateral in order to center on the LAD. So it's really important for the rest of the procedure that we have the target in the center of the field, so I'm happy about this.
So I’m going to extend the incision cranially, and we are now able to appreciate this very nice target. Is it visible on the screen? It is. It's a beautiful target - I'm guessing between 1.75 to 2 millimeter in diameter, so very nice target. I'm going to gently palpate and the site that I’ll choose for the anastomosis is-it's right here and just proximal to that, I feel a calcification. Ory, you’re going to put your finger over, you'll feel a calcification - yeah - but if you if you slide distally, you’ll see that's nice and soft. So this is. So this is exactly what we want. We want the location of the anastomosis to be free from disease, and leave the disease proximal.
So the next step here, we have established that our main target, the LAD, is suitable for anastomosis. The next question is whether the diagonal branch that was identified as having a lesion is of a size that’s at least 1-1/2 mm or greater, and so far I have not really been able to appreciate it so I'm going to open this supracortical incision a little more.
And the - what I'm going to do, I'm going to lift the pericardium on the right side and try to identify the diagonal branch. In my opinion, oversize - it is not amenable to a bypass, so I will plan at this point, to stay with the original single vessel bypass with the left anterior mammary artery to the left anterior descending coronary arteries.
So the first step of the operation has to be done prior to any harvest. You have to make sure that the target for revascularization is available and is a suitable, so we checked all those. So the next step in this procedure is the harvest of the mammary artery, and we do that under direct vision through this small incision. So this first part - I need an incision tool please.
This part can be done the way I'm doing, under direct vision, or it can be done also endoscopically with with the - the robot so it can be done with the DaVinci robot as well, but we're doing it direct vision. So I need that the metal tip sucker. Connect it here. So we use the Bovie extender and the setting is is low - about 20 joules. And so - what I'm doing here is moving medially until I identify the mammary artery, so you have to be very careful here as you do this maneuver that you don’t injure the mammary. So the first step, it will be the mammary vein - the lateral mammary vein - I will encounter, and after that I will - I will identify the mammary artery. And if you look on the screen - you probably are - you can start seeing the mammary vein.
And I’m dividing the fascia as I move medially, and the artery is probably laying in this plane. It's right here, so you can see the fascia underneath here. See the endothoracic fascia, which actually I’m going to divide. This is the lateral vein and then the mammary artery is the white structure right underneath here. Slightly below the sixth rib here. You see the artery there.
That’s the medial vein, and I'm just creating some space in the section of the distal part of the mammary. Again very careful here that in this process you don't injure the mammary.
So the next step is we - we trade this retractor, which we will use later, for the LIMA lift. So LIMA is acronym for the left internal mammary artery, and LIMA Lift is a device that is designed specifically for harvesting the mammary under direct vision. This is one of the vendors that we use, and we - we have a choice of the the upper blade, so, I think we can try, well, let’s try it with the smaller one for the upper blade and then we need to choose another blade for the lower and then the retractor. So this is the retractor. We mount the upper blade and requires a little bit of assembly, and we have choices here. And this will be the lower blade. This retractor again as two components - This blade will go inside the chest and as we spread, will create a degree of offset. It will allow us to see between the ribs and follow the mammary course. And this hook here will be connected to the rule tract and - and by adjusting also patient positioning, we’ll- we should be able to have a good exposure.
So we placed this plate inside the chest - careful not to engage the inside of the pericardium - so it has to stay outside the pericardium and we start spreading as you - as you see, as spreading, you can see the exposure improves. Throughout this part of the procedure the left lung is deflated, so the patient is relying on the right lung. So this is where, if - if we are not able to visualize, we could add a scope here for - for side views.
And incise the fascia medially. So the harvest is a little bit of a mirror image of the LIMA harvest that we performed through the sternotomy. Also, can you rotate table away from me a little bit. Stop, thank you. So, the beginning of the exposures for those who have not done this procedure often can be intimidating, but as we progress, it will get better. So again, the paramount is not to damage the mammary, so be watchful for any undue traction. So, you see we followed this pedicle that we have identified earlier. So see the mammary artery there? And we’re going to follow north. This is the endothoracic fascia and muscle. And… So every branch that we encounter - this is- one branch is here - we're going to place a clip. And then use the Bovie.
So this is a very important part of procedure, so we want to really take our time, have adequate exposure, and do a good job. Dr. Zenati, what will be the optimal length you will dissect on the liver? That's a very good question that’s somehow debated among those that perform this procedure. Some surgeons actually perform a short harvest, but I believe - I have used a harvest as high as possible definitely above the first rib. Okay. Because that provides flexibility, provides the ability to reach distal location on the LAD, and also, you have to keep in mind that we are performing this bypass with the lung deflated, but at the end of procedure, the lung will be re-inflated. And especially in patient with emphysema, COPD, the expansion of the lung especially the right upper - left upper lobe will potentially cause tension on the mammary, and that’s something that is very dangerous, and we try to avoid it at all possible. So the length prevents potential tension, so I believe it in a harvest that is more complete than what others would do. So that's-that's my philosophy.
So you can see now that I'm able to - to protect my pedicle, and I have now incised the fascia both proximally and - more - both medially and laterally and by using gentle traction, I’m able to progress cranially. So the ideal patient for this procedure would be somebody with actually some degree of emphysema because they usually have wider interspaces and that's actually makes this procedure easier.
So at this point, I'm going to start the following the mammary north, and actually, I am noticing that the traction on the my LIMA Lift is preventing me from having a good exposure on mammary, so I'm going to take this down and then add that extension. So I will have obtain a more favorable pull on the lift, so I'm going to modify my set up a little bit. So this will allow me to have retraction that is more toward the left of the patient because the mammary as - as you go north kind of curves - So, I need to… Well, let’s see if this adjustment has helped me with that.
So - so I have this suction device around the mammary. See, we are we're making progress. Every branch I encounter, I'm going to put a clip like this. You see the exposure actually is pretty nice. Yeah, okay, so always make sure there's no tension on the pedicle that you're developing and you see that dividing the fascia laterally and medially like this allows a nice progression. Microclip. I see- a branch - a perforating branch - so place the clip right at the base, and then we use the Bovie to divide the branch toward the chest wall. Yeah, I could probably get even a better exposure than the one that are showing, but I rather not do that, because this is good enough for me to harvest, and I don't want to overspread the ribs as the spread is associated with postoperative pain, and we're trying to minimize that. So it's one of our concerns. We try to minimize the ribs spreading.
Flip again. You see a vein branch there, so I'm going to again place a clip at the base and then Bovie on the chest wall side. See, we’re - we’re making nice progress. Our heavily calcified targets will be difficult. But this procedure is the basis in order for hybrid revascularization to be performed, so you need to know this procedure in order to work with your cardiologist performing hybrid revascularization. So the mini-mini MIDCAB LIMA to LAD is really a main stay of that approach as well so. Yes, so the hybrid approach consists of LIMA to the LAD and a stent for known LAD to target, so either - either circumflex or a right wrench.
So we're moving to the second intercostal space here. I need the table down a little bit more please. More Trendelenburg - I'm going to try to just get a little extra lift on this retractor to see the - the last part of the mammary and - table toward me a little bit - so again combination with small adjustments. The positioning hopefully will allow me, table up also, sorry, so we're just doing a little small, little adjustments. Perfect, no we’re good thank you. Clip.
So some surgeon will stop here and call it. I like to go higher for the reason I mention. Specifically because I like the line of the mammary to - to be a straight line from the take off from the axillary subclavian as opposed to take a curve medially and then curve back laterally. And I also - I really want to avoid at all costs, potential tension from the left upper lobe of the lung once it's inflated.
So this point you really want to advance millimeter by millimeter and... and carefully identify the structures and keep a dry field as much as possible. So if you can appreciate them, the tip of my sucker actually is - is showing you under the pleura, the mammary artery. And that's - that's where I would like to reach. So I still have a little bit to go from where I am to where I like to be. Are you able to see that mammary down here - tip of my sucker? Tip of the sucker right there? This is where I am, and this is where I want to be. And I need the table a little higher.
Clip. And as I said, some surgeons would have stopped already, but I like to go as high as possible and as comfortable, and hopefully today, this patient has very nice anatomy, I may be able to show you even the subclavian vein which is really the highest really we - we want to go. It will be above the first rib, so I'll take a clip again. Nicely placed clip back there. I'm going to divide that branch towards the chest wall. I’ll allow this to drop medially. And actually, you can see already the vein there - at the end of this pocket - I’ll show you better in a second. Rotate table toward me.
So again at this point, we're very high - we’re between the first and second rib - so I need to go more laterally. The mammary doesn't follow straight course but tends to curve, so for me to follow it now, I have to rotate the table towards - toward me. And then again, I'm pointing with the tip of my Bovie the mammary and I’ll show you where it - where I am, so I have a little bit more to go, but you see how the anatomy is opening up nicely for us. You can see a nice pedicle there. They developed it very nicely. Each branch that we divide, we obtain a better - better exposure.
A clip - another branch there. So now we're really reaching the physical limit of this long clip applier. You really need the entire length of this device to place a clip there. Again, there's nothing wrong with somebody choosing to do a partial harvest. This is the way I do it, and I think it pays off in the end if you do - if you have some experience with this procedure.
So I'm really, really reaching the end of the harvest here, see? First rib here I'm cleaning up. You'll see in a second better, and we should actually be able to visualize the subclavian vein shortly. Yeah, a LIMA to LAD under tension is probably one of the worst things that can happen to you, so with the complete harvest, you you you eliminate the that that that possibility - that we’re clearly above the first rib. Make sense? So we have complete harvest of our conduit. I’m very happy.
I'm going to give you another - another view of the entire mediastinum so - can you see that the phrenic nerve over here? Yes. Phrenic nerve is clearly seen. We’re clearly away from phrenic nerve - phrenic nerve. The lung is deflated there inside of the chest wall. This is our mammary - clearly, nicely harvested above the first rib which is right here, and we are following down and it looks- looks really good for us. So we're very happy with this harvest. And we're going to free this from some adhesion and at this point Suzanna, I think we are ready for - for Heparin, and I would say let's give him 7000 units.
Okay so I'll take a large clip. So we're going to divide in the mammary now, so we put the clip distally here. And we put a second clip, and you have the bulldog. The yellow with the sutures in. So we going to now clamp the mammary pedicle proximally. And what we do, we use this type of bulldog and we have a suture here. And the reason for the suture is that we don't want to reason lose - lose exactly - lose this clip in the chest, so we have a mosquito - we can lift it with a tether, and this allows us easily to retrieve this device in case it's lost in the chest. And then we going to divide the mammary.
So the mammary is now divided. And- you have a dog catcher?So we're going to test the flow of this conduit. Give it a tenotomy again. Alice again - Alice. So this flow is excellent. So this is a - we are very happy with the flow from this mammary. Do you have some Paprin? So we actually put some local Paprin here on this pedicle.
So for this procedure really, we’re very grateful to have an assistant like Dr. Quinn. It makes a big difference. Another one? Another 5-0 CV silk. And a microclip as well. See, so, the mammary is in the center of the field here. We're providing traction so the mammary stays exposed without us holding it. We put this - this is a 5-0 cardiovascular of silk. We use it to just tack the mammary to the edge of the mini thoracotomy incision. This way my assistant Dr. Quinn has - free hand- both hands free to assist me with anastomosis. These additional tissue retractors here are useful in males, but even more useful in females, holding the breast out of the way. You can imagine this incision will be below the breast fold and this - this retractor will allow to have the breast out of the way.
Okay, so we again are - Jackie, you want to feel again our target? I think we assessed it. It looks pretty good with this calcification up here - put the finger here. So but - where we are going to do the anastomosis it looks very good target. Okay. So the next step, is we’re going to prepare the mammary. So I'll take a Jacobson please, Jamal.
Can you keep this vein out of my way? I'll take a micro clip and Jacobson. Going to go here. Okay. So we’re going to prepare this - this mammary. Okay we're looking good. The mammary is already spatulated and looks good for our anastomosis. And give some paparin, since we're going to irrigate.. Some Paprin to irrigate. So you can see that that the - the harvest all the way up to the takeoff allows us to really have a nice length of mammary. And- I anticipate that the end-to-side anastomosis will be free from tension, which is the critical component of this procedure, avoiding tension.
And so the next step crucial is I need to provide a proximal occlusion of the left anterior descending coronary artery. And we'll do that using a 4-0 Prolene with an SH needle. Sure. And I'm going to take a relatively large bite with tissue - around the left anterior descending coronary artery. Again, there are several ways to obtain a proximal occlusion. There are Silastic tapes, but in my opinion they come with a needle - let me do it - that it’s too large and creates a potential for bleeding so I like to use a Prolene with an SH needle. And the key as you can see here is to have 4, 5 mm of buffer between the artery itself and and the suture.
Again, you have to be cognizant that you are working around the LAD so any undue traction here could be dangerous. So, we are still trying to achieve our target ACT. We have given additional Heparin and we're, again, targeting between - so cut this please. And then we'll use this slider around. Again, we have to at all costs try to avoid tension here, so let go please. We have to slide this. Again, no tension on the LAD.
So we call this component a bumper, and this bumper will provide us with control of the proximal blood flow. I'm going to try to put some tension on this bumper, so this will provide some degree of narrowing of the blood flow to the LAD. And we are at the point now keeping an eye on the EKG. So, with two leads on the EKG, and we have the ST segment is - is monitored by the - our anesthesiology colleagues, Dr. Licener here. So if there is any elevation of the ST, you will let me know, but we’re not going to try to achieve a complete occlusion of the flow. We just-kind of finger tight. And then - and then we'll tack this to the side.
The next step is to provide stabilization of our target, so this is beating heart surgery. We’re now using the heart-lung machine, and we need to stabilize this LAD. So I need the tray for the MIDCAB retractor and we’re going to use a pressure stabilization device. There are two categories: one is a section stabilization, most well-known is the octopus device, but this works well together with this retractor, and it’s a pressure stabilization device. So by applying gentle pressure on the surface of the left ventricle, we can stabilize this area of tissue including the coronary, and we’ll be able to perform an anastomosis.
So there are two choices. I think I would like to have the other configuration with the - arm coming off the other side and then - this is a little bit of like in erector set. So we have a small space here, and we're going to try to make the best use as possible of this small environment. Also trying to provide enough space for Dr. Quinn to do first assist. So you see this device? We’re going to lower into the wound. Again, I could try to make this incision bigger by cranking up the retractor. I choose not to. I try to provide a retractor with - provide exposure but no more than that. I need a forcep please. So, I'm going to actually move this out of the way like this. Now we’re gonna - we’re gonna lower this stabi - stabilizer in place. And place it across on the LAD.
So we don't really- our goal is not to eliminate motion, but to minimize it. So this is our LAD. 2-0 pop-off. So we have our mammary here. We have the Bulldog clamping proximally, and we have the LAD immediately below. So this is the setup is pretty much as good as it gets for this procedure.
We are approaching the point where we going to go through our final checklist. So we went to have an ACT about- between 280 and 300. I think we we we are there. Right, we were going to wait for another ACT, but we already we already good in terms of - I’m going to occlude here proximally one more time. That's actually the next on the checklist, so I think the shunt here will be - I will start with a 2 millimeter shunt, and you can open that and have a 1.75 available next.
So again I re-sneered the proximal LAD. Okay, I'll take another forcep and a beaver blade. So my assistant Dr. Quinn here will use this device which is a Blower Mister. We - we flow about 3 liter per minute of CO2 and also we have saline. So again, we're exposing our target and this LAD looks - looks very good. We’re confirming a size of-approximately 2 millimeter. So we're starting with a 2 millimeter shunt and - we’ll then decide. I need a 5-0 CVO next.
Mammary’s ready. Our target - we're doing the final preparations. Our ACT is fine, we're happy with this degree of stabilization, and you can appreciate how the myocardium outside of the stabilization is moving quite a bit. While the myocardium within the jaws of this the stabilizer is relatively still. Doesn’t have to be completely still. I going to put a stay suture again to improve my exposure so cut here please. I need a mosquito.
So this is our small field. You have a ruler for second? Just - just give you a sense of - of the size of this field so we’re - so this is - this is 2 inches. 1 and 2 inches, so this is about 5 cm. So this is how big it is - this field here. But you can see you know if we organize it well, we have the LAD, the mammary, control of the proximal stabilizer.
So this - this 8-0 has to be loaded backhand and need a rubber shod on the end - and I will need a second 8-0 to follow. So I preload this before my first bite. So that the plan here is to do a separate heel-and-toe anastomosis. So I am right above the coronary. So I have to modify my technique, so the surgical technique will be outside-in bite on the mammary. Outside-in. Followed by an inside-out on the coronary. And then repeat it two times, and finally, I’ll tack the suture for the heel up here. And then I'll use a separate suture, and I will do three bites running on the toe. Following that, we will parachute the mammary down and then complete the anastomosis on both sides.
So the mammary- this is ready, and I need that the shunt please. So I’ll demonstrate the shunt. This is a - a intracoronary shunt. And the - the 2 millimeter refers to the size of - of this. So this will be placed inside the coronary after I do the arteriotomy. And then the proximal snare will be released and the channel will allow perfusion of distal LAD while I perform the anastomosis. So this is 2 millimeter - is my best guess, but we have sizes above and below that will match the artery. So this will minimize ischemia of the myocardium, also the blood loss.
So I think we're ready to proceed. Anybody has any questions at this point? Okay, thank you. So I'll take a beaver and also Dr. Quinn is going to be careful to use this blower aiming toward the bumper as opposed to distally. We try not to introduce any air into the coronary. So we’re ready to perform the arteriotomy. Have a Jacobson ready.
Okay, so, we performed the arteriotomy. We’re going to extend this a little bit. Proximally and distally. Sorry. Then I'll take the shunt. So here's our shunt. We’ll introduce the shunt into the coronary artery. So a 2 millimeter shunt is a little bit snug here, so can you please open this 1.75 shunt? It - don't blow just - just give me a second. Can I have a Jacobson again, one more time? I’ll take a 1.75 shunt. Are you able to see the shunt being introduced in the artery? On the screen?
Okay, so the shunt is in place. So next I'm going to release the proximal snare on the LAD so we’ll provide flow again through the LAD. So you see, I am releasing the bumper here and the suture so now there is flow through the LAD. We have visualization of the heel and toe in order to perform the anastomosis.
So as I indicated earlier, our first bite will be an outside-in on the mammary. You see that the way we set it up, we don't have any need for an assistant to hold the mammary. So this is a convenient way, and then we place the rubber shod over here. Try to cover this so they don't get caught. And now the next bite will be an inside-out at the heel. Thank you Jackie - the exposure’s very nice. We also use the blower very sparingly - only when I'm working on the artery. So again, outside-in. So, this is the last bite for the heel. Outside-in. And the last bite is going to be inside-out on the coronary. You’ve got be careful not to catch the shunt with our suture. I’ll take a rubber shod. And a new 8-0, loaded forehand. And we’re going to place this here Jackie. Okay, blow.
So now we're going to do the toe. See the coronary visualization is excellent. Our shunt is working well - there's no blood loss. Let go please. You don't need to follow. And we're going to move toward me. Okay - very good. So at this point, I need a tenotomy suture. I'm going to release these two sutures that I used to hold the mammary in place. 1 and 2.
And now we're going to parachute the mammary down so - so I will need that. Actually, give me that rubber shod. Let go of that one - just drop it. Okay then I'll… Here's a-this one's in a shod and that one's free. This-this guy's free. I'm going to do your side of the anastomosis. I'm going to complete the- I don't need that exposure - so I can exposure myself. I don't need to follow your - just can you put some saline on that blower? Alright. If there's no saline, I need some saline or we’re just desecrating the vessel. That should do it. We’re going to tie on this side. You cut this needle for me? And squirt in my hand? The right hand.
So we’re getting there. Probably need another minute or so. See the stabilization is really excellent. Every bite was a high-quality and we're - we're very - very happy with exposure here. I will take the scissor please. So for the home stretch, so this will be the final side of the anastomosis. I get this. How about I try to grab it this way? Let go of the artery? Yes. I can hold the shunt. Here, let me try to grab this shunt.
Okay, now switch to the other side. Wait - let go. At this point I like to flush the mammary just to make sure we de-air it and we confirm that we have a good flow, and we have excellent flow and clamp again. So pretty soon, we’ll have to retrieve the shunt from the incision to the arteriotomy. So.
So at this point we’re going to pull the shunt. Here’s the shunt, and we’re going to do one more superficial bite to complete the anastomosis.
And we're done. So squirt my hand. So at this point the LAD is open. We're completing this last knot on the anastomosis, and next we’re going to open the mammary.
And we’re going to open the mammary next. And the anastomosis is now working. I’ll take paparin and we’re done.
So this is the Bulldog retrieved, so we don't have anything left in the chest. We're going to put some paparin on the anastomosis. There's no bleeding. And there's no tension - you see the mammary is nice and loose. So this is really important microclip. We’re going to - next we’re going to remove the - the clip here. Sorry, I can't see it - I’m assuming you can see it okay. Another microclip. I’ll take a flow meter. So we're going to release this stabilizer. You have to be careful it doesn't - nah! Okay - just make sure I don't get caught with the mammary. It’s a small space, so we're done with the stabilizer. And I'll take a scissor again. And this is the last thing - left over, this is our snare.
And that’s it. This is a completed operation. It's a beautiful mammary to the LAD - working. We're going to scrutinize a little bit here. So I can fit a flow probe. We're going to confirm patency. So we're looking for the flow. That is somehow - I’m doing 20 mLs per minute or so. What are we reading? You’re reading a-. So the flow is excellent -it’s about 50 60 70 80 mLs per minutes. So approaching 100 actually. And push print please.The flow is biphasic diastolic dominant so that's what we're looking for. So we’re happy. The flow is approaching 100 mLs per minute - for single coronary is very high, and we have a positivity index of 1.3, so we are-we're relatively confident that we have a high-quality anastomosis that’s patent for this patient.
Okay so basically we’re - we’re satisfied with everything here. The operation is done, and now we need to close and provide the perioperative analgesia. So we are going to use cryoablation as well as an intercostal nerve block.
I’ll take a 2-0 vicryl. So I will use here the - the fat pad that I mobilized earlier to - to close and cover my anastomosis. See this is the fat that we mobilized earlier and we’re going to move it over to protect the mammary - make sure it doesn't get stuck on the chest wall. 2-0 vicryl. And you’re going to open the cryoprobe for us? The chest tube will be a 28 straight. Yeah - no - it’s going to be relatively anterior and we’re going to go posterior to the chest tube - yes. We need a narrow malleable as well please.
Okay. Knife out. So we're going to use a cryoablation, and the purpose is to provide several weeks of stunning of the intercostal nerves, provide numbness on the anterior chest area for pain control, so I'm going to go on the opposite side we're going to expose - provides a linear cryoablation. So, the nerves along this line will be temporarily ablated but they will regenerate within weeks of the procedure.
The purpose here is to go as lateral as possible to intersect the intercostal nerve as close as possible to the spine. At this point cryoablation, intercostal block, we're going to place a chest tube, and then we going to close the wound, and the next step will be hopefully the extubation of the patient in the operating room.
So this is at the level of the 5th intercostal space, so we’re gonna freeze for 2 minutes. That’s the a protocol. The probe is positioned just below the ribs to catch the intercostal nerve. So this is not a-you know-irreversible ablation of the nerve - it’s a temporary ablation, and the nerve regenerates within six, seven weeks. We will do a total five of these ablations: one at this level and then 2 above, 2 below. And we’ll supplement that with the short-term coverage with injection of intercostal block with marcaine. So the two work together - should provide a good perioperative analgesia.
So 6-15 - some more seconds for the second ablation. This is liquid nitrogen - goes to minus 70. Saline. So I’ve done the space and the two above, so I need the two below. Yeah, freeze. I’ll take a chest tube guys. Tonsil. I don’t care - I mean I'll take the chest tube if you got it but…Tonsil. Chest tube. Oh this is an Argyle - okay - you want a straight? Right okay. Okay. Okay I'll take a pericostal. I'll tell you what then, I'll take the skin stitch. You want to- I want to aim it a little towards the back. Pericostal. And you want to get ready for re-expanding the lung. Hey can you cut that Chris? I'll deal with that in a second. Let me just see if I can - I got a nail on the driver there. Guys, I'll take another Army-Navy if you’ve got one. Yeah hang on - stay still. I’m going to steal that. You have a-forcep please. Here, I’ll tell you what. Let me just- Forcep. Pick up please. Okay. Okay, Let’s take a stitch. Can you connect the chest tube?
So as you - as you can see, we just completed the procedure. The skin is being closed and our anesthesiology colleagues are in the process of waking up and extubating the patient on the table. We believe the operation was very successful. We encountered a very favorable anatomy for this procedure. So, we are pleased that patient selection was - was correct. The - the isolation of the left lung was textbook thanks to Dr. Zorca. We had excellent exposure of the mammary artery bed, and harvest was - was uneventful. The target for bypass was very good quality, about 1.75 millimeter. The anastomosis, we believe it was a high-quality. We confirmed patency using a transthoracic flow meter, and the flow through the graft immediately after anastomosis was approaching 100 mL per minute, which is excellent. And the positivity index was the 1.3, which also is associated with long-term patency of the graft. And the flow pattern was actually diastolic dominant, demonstrating the widely patent anastomosis. We were very careful and spent a good 15 minutes performing high-quality analgesia using a cryoablation, so we're confident that we provided a very good perioperative pain control for this pleasant gentleman, so overall we were very satisfied with the procedure.