Minimally Invasive Cardiac Surgery

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Chapter 15 Minimally Invasive Cardiac Surgery

Marianne Coutu, MD, Lishan Aklog, MD, David Reich, MD

Since its early days, cardiac surgery has typically involved large incisions with complete access to the heart and great vessels. After the popularization of minimally invasive techniques in general surgery, cardiac surgeons began to experiment with less invasive procedures in the early 1990s. Although the goals of minimally invasive cardiac surgery (MICS) are fairly well established as decreased pain, shorter hospital stay, accelerated recuperation, and improved cosmesis, a strict definition of minimally invasive cardiac surgery has been more elusive. “Less invasive” is probably a more appropriate term, because these procedures span a wide spectrum from full sternotomy off-pump procedures to totally endoscopic procedures. There has been an ongoing debate within the specialty whether eliminating sternotomy or cardiopulmonary bypass (CPB) is a more fundamental component of MICS. Some have even argued that cardiac surgery will not be truly minimally invasive until general anesthesia itself is eliminated and a handful of centers have reported on various off-pump coronary artery bypass grafting (OPCAB) procedures performed with high thoracic epidural anesthesia alone.

This chapter focuses on the anesthetic implications of operations performed through an incision other than a full sternotomy or thoracotomy and does not address the various endovascular procedures under development. The common incisions used for these procedures are shown in Figure 15-1 and include partial sternotomies (upper vs. lower, unilateral vs. bilateral) and minithoracotomies (anterior vs. anterolateral vs. posterolateral, nonspreading vs. spreading) in addition to totally endoscopic procedures done exclusively through thoracoscopic ports (defined as < 15 mm).

Figure 15-1 A, Lower hemisternotomy. B, Upper hemisternotomy. C, Parasternal incision. D, Anterolateral minithoracotomy. E, Full sternotomy with small skin incision.

GENERAL ANESTHETIC CONSIDERATIONS

Patient Setup

Position, Prepping, and Draping

Conventional cardiac surgery is almost always performed with the patient flat and supine, prepped, and draped with the sterile field extending from mid-neck to the ankles (Box 15-1). Many MICS procedures, however, require different positions and sterile field setups. For example, most procedures performed through anterior minithoracotomies or exclusively thoracoscopically are done with the patient’s left or right side elevated approximately 30 degrees. Some thoracoscopic procedures are performed in the left or right lateral decubitus position, typically with the hips rotated to expose one or both groins for possible femoral vascular cannulation. Unlike conventional sternotomy procedures, surgical access to remote areas (neck, lateral chest wall, groin) may be necessary for peripheral cannulation, placement of camera/instrument ports, or transcutaneous retraction sutures. This should be taken into consideration when placing ECG leads or other items on the skin during setup.

BOX 15-1 Anesthetic Considerations

• Position, prepping, and draping

• Temperature management

• Hemodynamic monitoring

• Airway management

• Anesthetic regimen

• Pain management

Because, by definition, access to the heart is limited in most MICS, external defibrillator pads should be considered mandatory. Again, care should be taken with placement and draping to ensure the current passes through the heart and that burns associated with seepage of prep solution or other liquids under the pads are avoided.

Temperature Management

Because nearly all MICS and all off-pump procedures are performed under normothermic conditions, careful temperature management is critical to avoid hypothermia, which not only can lead to ventricular fibrillation and bleeding but also can negate some of the potential benefits of MICS by prolonging the time to extubation. In addition to maintaining room temperature, one of a variety of warming blankets is usually required. Although conventional water or forced warm air blankets can suffice, more innovative solutions such as the Kimberly-Clark Patient Warming System (formerly the Arctic Sun) may be particularly advantageous in MICS.

Hemodynamic Monitoring

Hemodynamic monitoring requirements for MICS are typically not different from those of conventional cardiac surgery. Most patients have radial arterial and pulmonary artery (PA) catheters placed. Some centers limit themselves to a central venous pressure catheter, especially in patients with normal ventricular function undergoing MICS. Intraoperative transesophageal echocardiography (TEE) is the standard of care for all valvular surgery, and it can be critical in MICS cases to assess ventricular preload and pick up early changes in regional or global ventricular function, because visualization of the heart may be limited. In addition, TEE is helpful and often necessary to guide placement of various catheters, cannulae, and balloons. Because access to a ventricular wall for temporary pacing wire placement can be limited in some MICS approaches, a PA catheter with a pacing port can be helpful in valve procedures or other cases in which the need for temporary cardiac pacing may arise.

Anesthetic Technique

Airway

Many MICS procedures, including all minithoracotomy and thoracoscopic approaches, require at least some period of one-lung ventilation. Double-lumen endotracheal tubes are generally preferred because they are less likely to be dislodged during repositioning. It is critical to take the time to confirm proper placement and lung isolation before and just after positioning, because loss of lung isolation during an anastomosis or during some other critical stage of the procedure can be extremely dangerous.

Carbon dioxide insufflation of the hemithorax is frequently used during thoracoscopic MICS procedures, especially during robotic procedures. Insufflation to a pressure of 8 to 15 cm H₂O can dramatically increase the working space in the chest by shifting the mediastinal structures posteriorly and to the contralateral chest. Because there is always some obligatory leak around ports and incisions, the constant flow of CO₂ also clears smoke generated during electrocauterization of tissues. The intrathoracic pressure should be set to the minimal value necessary to achieve adequate exposure, and very careful monitoring of hemodynamics and gas exchange is essential, because the physiology is effectively that of a controlled tension pneumothorax. Although generally well tolerated, significant hypotension, hypercapnia, or hypoxia can occur if the pressure is set too high, particularly in patients with ventricular dysfunction or lung disease.¹

Anesthetic Regimen

Because accelerated recovery and discharge are major goals of MICS, it is important to note that careful selection of the anesthetic agents is necessary to ensure that the patient obtains the full benefit from the minimally invasive approach. Most centers will use some sort of “fast-track” anesthesia regimen—typically very short-acting narcotics and muscle relaxants in conjunction with an inhalation agent.² Some have advocated precise pharmacokinetically controlled total intravenous anesthesia (TIVA) regimens. Routine intraoperative extubation of MICS patients is controversial. Although some centers have established protocols whereby nearly all patients are extubated at the completion of the procedure,³ others have argued that a clinical or economic benefit is difficult to document unless the patient recovers in a postoperative acute care unit setting without an overnight stay in the intensive care unit.⁴

Pain Management

Aggressive pain management is another critical component of the care of patients undergoing MICS, without which it is difficult to obtain the full benefit of this approach. Successful pain management permits intraoperative or early postoperative extubation, early ambulation, and discharge. There is some evidence that the amount of pain in the early postoperative period may not be significantly less in many types of MICS and that it may actually be higher in some, particularly those involving rib-spreading thoracotomies. The pain, however, seems to dissipate more rapidly than with full sternotomy; most patients are off narcotic pain medicines within 1 or 2 weeks of surgery.⁵

Spinal/Epidural Anesthesia

Spinal and epidural anesthetics have been used as an adjunct to general anesthesia at many institutions practicing MICS. A single intrathecal dose of a long-acting narcotic can be beneficial in reducing intraoperative and postoperative parenteral or enteral narcotic requirements.⁶ A thoracic epidural catheter with narcotic or local anesthetics can be administered continuously or with patient-controlled dosing.⁷ The excellent pain control and potential cardioprotective benefits from this approach, however, are mitigated by the additional operative time, the small but finite additional risk from the epidural anesthesia, and its potential to delay the typically rapid mobilization and discharge of MICS patients.

Local Anesthesia

Every effort should be made to supplement the pain management of MICS with local measures at the surgical site. This can include conventional methods such as direct infiltration of the wound with a long-acting local anesthetic such as bupivacaine or intercostal rib blocks extending a couple of interspaces above and below the incision.

GENERAL CARDIOPULMONARY BYPASS CONSIDERATIONS

Although nearly all minimally invasive coronary artery bypass surgery is performed on a beating heart, without the use of CPB, minimally invasive surgery of the cardiac valves and other intracardiac structures requires creative and innovative techniques to safely establish CPB (Box 15-2). There are a variety of approaches depending on the incision and access to cardiovascular structures. Some minimally invasive approaches permit direct, central cannulation similar to conventional cardiac surgery but typically with relatively small cannulae and vacuum-assisted venous drainage. On the other end of the spectrum, “Port-Access” techniques, pioneered by Heartport, Inc. (Redwood City, CA) in the early 1990s, sought to have all elements of the CPB circuit enter peripherally, preferably percutaneously, to allow procedures to be performed through very small incisions or totally endoscopically. The anesthesiologist plays a central role in all “Port-Access” procedures from insertion of certain cannulae to monitoring cannula position and function by TEE.⁸

BOX 15-2 Cardiopulmonary Bypass Considerations

• Arterial cannulation

• Venous cannulation

• Aortic occlusion and cardioplegia

• Cardiac decompression and de-airing

Cannulation

Arterial

Some MICS approaches, including most partial sternotomy incisions, permit direct cannulation of the ascending aorta in a fashion similar, if not identical, to conventional approaches. Some surgeons use aortic cannulae with tapered dilators designed to be inserted over a guidewire to facilitate direct cannulation through a limited incision. Through many MICS approaches, however, the ascending aorta cannot be safely cannulated and peripheral cannulation is necessary. The femoral approach is most commonly used. The axillary artery is a viable alternative but is not usually used in MICS because accessing it usually requires a cosmetically prominent 3- to 6-cm incision. TEE assessment of the descending aorta is important before considering femoral artery cannulation to rule out extensive atherosclerotic disease, which can lead to retrograde embolization and neurologic injury.

Femoral arterial cannulation can be achieved percutaneously but is usually performed through a very small transverse incision guided by the pulse or a Doppler signal. The cannulae can be short, with the tip sitting in the pelvis, or long, extending into the thoracic aorta with multiple side ports. Contraindications include significant peripheral vascular disease. Potential complications include retrograde dissection, embolization, and perforation with retroperitoneal hemorrhage.

Venous

Even though the right atrium (RA) is accessible in many MICS approaches, percutaneous femoral venous cannulation has become popular because it removes the venous cannulae from the operative field, enhancing exposure. The right femoral vein is usually used because the right common iliac vein joins the inferior vena cava (IVC) at a much straighter angle, facilitating advancement into the RA. Modern, highly efficient long venous cannulae as small as 20 to 21 Fr, coupled with vacuum-assisted venous drainage, can support full CPB flows even in large individuals. TEE is used to confirm guidewire and cannula position during percutaneous insertion.

A single cannula with the tip near the RA/superior vena cava (SVC) junction and side ports spanning the RA usually suffices for aortic valve operations. Situations in which surgical manipulation can interfere with SVC drainage must be considered to avoid complications due to upper body venous hypertension. In mitral valve operations, for example, retraction of the RA and septum can interfere with drainage. The Chitwood transthoracic aortic clamp, used commonly in videoscopic and robotic mitral valve surgery, passes over the SVC and can compress it. RA procedures (atrial septal defects [ASDs], tricuspid surgery) usually require separate IVC and SVC drainage. In these situations, improved drainage can be ensured by using a two-stage long venous cannula that can be advanced into the SVC itself. Another approach is to cannulate the right internal jugular vein percutaneously with a small cannula advanced into the SVC.

Aortic Occlusion and Cardioplegia

Intracardiac procedures usually require aortic occlusion and cardioplegic arrest. In direct-access MICS procedures, direct clamping of the aorta can be achieved with conventional, slightly streamlined, or articulating aortic clamps. Videoscopic and robotic procedures, however, require some type of remote aortic occlusion. The two most common options are the Chitwood transthoracic clamp and balloon occlusion. The Chitwood clamp has conventional jaws, but a long shaft, and is passed through a separate port in the right chest with the posterior jaw in the transverse sinus.

Balloon aortic occlusion is the centerpiece of most Port-Access approaches. A catheter with a large, low-pressure balloon is passed via the femoral artery and positioned with the balloon in the ascending aorta under echocardiographic guidance. The balloon is inflated until the pressure in the port distal to the balloon falls, confirming occlusion of the ascending aorta. The right and left radial artery pressures are monitored simultaneously to ensure the balloon is not impinging on the orifice of the innominate artery. Balloon migration can be an irritating problem early in the learning curve, but experienced centers report good results with routine use of this technique. However, all centers emphasize careful collaboration among the surgery, anesthesia, and perfusion teams. Continuous TEE monitoring of balloon position is important to prevent complications. The most dreaded complication of this technique is aortic dissection, and some reports indicate that the incidence may be higher than in conventional surgery.

Myocardial protection during MICS can be achieved via an anterograde, retrograde, or combined approach. In direct-access and videoscopic approaches, the anterograde cardioplegia catheter is usually directly inserted into the ascending aorta. In the Port-Access approach, the cardioplegic solution is infused through the distal port of the balloon catheter into the aortic root. In direct-access approaches, a retrograde catheter can be advanced into the coronary sinus, with or without echocardiographic guidance. The Port-Access system includes a percutaneous retrograde coronary sinus catheter that is inserted by the anesthesia team through the right internal jugular vein and advanced under echocardiographic guidance.

Cardiac Decompression/De-airing

Limited visibility of and access to the cardiac chambers during MICS can make the critical steps of cardiac decompression and de-airing more difficult and requires special attention to avoid the potentially devastating complications arising from unsuspected sustained myocardial distention or air embolism.

The most vulnerable period for distention is during administration of antegrade cardioplegia and immediately after removing the cross-clamp before restoration of ventricular ejection. The ventricular dimensions on TEE and the pulmonary artery pressures should be monitored closely to ensure adequate ventricular decompression. Patients with thick, small-cavity ventricles may be particularly difficult to monitor because the ventricle may not appear particularly dilated on TEE despite an elevated cavitary pressure and because they are more susceptible to subendocardial ischemia. A left ventricular (LV) vent can be inserted through the right superior pulmonary vein in some patients undergoing direct-access MICS. The Port-Access system includes a percutaneous pulmonary artery vent that is advanced through the jugular vein and can maintain decompression. A terminal dose of warm blood in the aortic root can rouse the heart and initiate ventricular ejection before removing the cross-clamp, avoiding distention.

Because manual manipulation of the cardiac chambers is usually impossible with MICS, the best way to deal with intracardiac air is to prevent it from accumulating in the first place. Flooding the surgical field with CO₂ while the chambers are open can dramatically decrease the amount of air. Some de-airing is usually necessary, and manipulation of the table while ventilating and filling the heart usually facilitates this.

MINIMALLY INVASIVE CORONARY ARTERY BYPASS GRAFTING

The goals of minimally invasive coronary artery bypass grafting are to reduce the surgical trauma by minimizing access and to obviate the need for extracorporeal circulation (Box 15-3). These procedures encompass minimally invasive direct coronary artery bypass grafting (MIDCAB), totally endoscopic coronary artery bypass grafting on an arrested or beating heart, and multivessel small thoracotomy revascularization.

Minimally Invasive Direct Coronary Artery Bypass Grafting

MIDCAB is a coronary revascularization procedure through an anterolateral thoracotomy. Patients who should be considered for a MIDCAB are those with isolated left anterior descending (LAD) or right coronary artery (RCA) stenosis, patients with multivessel disease in which the lesion in the other vessels can be addressed percutaneously (hybrid procedure), and patients with multiple comorbidities.

The patient is positioned supine on the operating table. External defibrillator pads are placed allowing space for sternotomy access in the event of a conversion. A double-lumen endotracheal tube or a bronchial blocker is used to collapse the left lung. Standard monitoring for cardiac surgery is used, plus TEE to monitor cardiac filling and myocardial segmental wall motion abnormalities.

This procedure is performed through a small anterolateral thoracotomy. A 6- to 10-cm incision is made over the fourth intercostal space, the pleural space is opened, and the ribs are spread with a specialized left internal mammary artery (LIMA) retractor. The LIMA is harvested as a pedicle (length of about 15 cm) and prepared after systemic heparinization. The LAD is then identified, dissected, and opened after the heart has been stabilized. Finally, the LIMA is anastomosed to the LAD on a beating heart through the thoracic incision. This procedure can also be performed for a proximal high-grade RCA stenosis through a right anterolateral thoracotomy using the right internal mammary artery (RIMA).

The main advantages of the MIDCAB procedure are the avoidance of CPB and median sternotomy, potentially less postoperative pain, and faster recovery to normal activities. Studies showed good short-term patency rates of the LIMA-to-LAD anastomosis.⁹

Totally Endoscopic Coronary Artery Revascularization

It is the development of computer-enhanced telemanipulators that has enabled robotically assisted surgery and totally endoscopic coronary artery revascularization. The currently available system, the DaVinci Telemanipulation System (Intuitive Surgical, Inc., Sunnyvale, CA), provides a high-resolution three-dimensional videoscopic image and allows remote, tremor-free, and scaled control of endoscopic surgical instruments with 6 degrees of freedom. It consists of a master console for remote control of microinstruments mounted on a surgical cart with three arms (one stereoendoscope and two endothoracic end-effectors). This procedure can be done on the arrested heart and on the beating heart and is most often performed for single- or double-vessel coronary artery disease.

Totally Endoscopic Coronary Artery Bypass on the Arrested Heart

The most frequently performed procedure using this technique to date is revascularization of the LAD with the LIMA via a left-sided approach.¹⁰ The RCA can also be grafted with the RIMA via a right-sided approach.

For robotically assisted LIMA harvest, patients are placed in a supine position with the left side of the chest elevated 30 to 40 degrees. Ventilation of the right lung is performed. A 30-degree scope angled up is inserted at the fourth intercostal space (ICS) in the left anterior axillary line. Continuous CO₂ insufflation (<10 mmHg) of the thoracic cavity is used to enhance exposure by increasing the available space between the heart and the sternum. Two endoscopic instruments used for LIMA harvesting are then placed under direct vision through ports in the third and seventh ICS in the midaxillary line. The LIMA is dissected as a pedicle from the subclavian artery to the bifurcation. After systemic heparinization, the LIMA is transected at its distal end. Femoral-femoral CPB is initiated by using the Port-Access system for closed-chest and antegrade cardioplegic cardiac arrest. The femoral venous cannula is positioned in the RA under echocardiographic guidance. After institution of CPB, the pericardium is opened, the target vessel is identified on the beating heart, and the epicardium over the anastomotic region is dissected. The heart is arrested using the endoaortic occlusion catheter and cardioplegia administration. The coronary anastomosis is performed end-to-side with a running suture (7-0 or 8-0 Prolene) or interrupted sutures (U-clips). After completion of the anastomosis, the endoaortic occlusion catheter is deflated and the patient is weaned from CPB.

Totally Endoscopic Coronary Artery Bypass Grafting on the Beating Heart

The development of endoscopic CABG on the beating heart required the development of endoscopic stabilizers and methods for temporary coronary occlusion. Vascular occlusion can be achieved by using vascular clamps or Silastic bands. For this procedure, the patient is prepared as described earlier. In addition to the three left-sided ports, an endoscopic epicardial stabilizer is inserted through a subxiphoid port after harvest and preparation of the LIMA. Endoscopic stabilizers use combined pressure and suction stabilization to facilitate the performance of the anastomosis. Because the heart is not decompressed with this technique, the space in the thoracic cavity is limited despite CO₂ insufflation. In this particular situation, CO₂ pressure may be increased above 12 mmHg if the heart is sufficiently filled and myocardial contractility is adequate. Compared with full-sternotomy beating heart surgery, the myocardial tolerance to ischemia in beating heart totally endoscopic coronary artery bypass grafting (TECAB) is reduced. After occlusion of the target vessel, if severe ST-segment elevation or multiple extrasystoles appear on the ECG, the conversion threshold to MIDCAB should be low.¹¹ The anastomosis is performed with a running suture (7-0 or 8-0 Prolene), interrupted sutures (U-clips), or distal anastomotic devices.

Even as progress has been made, as with all new technologies, a learning curve has to be overcome. Operating times are still long and conversions to open surgery are frequently necessary. A lot of steps occurring between IMA takedown and performance of the anastomosis are hampered by the lack of assistance, limited space, the lack of fine tactile feedback, and a limited number of instruments.

MINIMALLY INVASIVE VALVULAR SURGERY

Valvular procedures such as aortic valve replacement and mitral valve replacement and repair are now performed using different types of minimally invasive procedures (Box 15-4).

BOX 15-4 Minimally Invasive Valvular Surgery

• Minimally invasive aortic valve surgery

• Minimally invasive mitral valve surgery (MIMVS)

• Direct-vision MIMVS

• Video-assisted and directed MIMVS

• Robot-directed MIMVS telemanipulation and computer-enhanced MIMVS

Minimally Invasive Aortic Valve Surgery

The goals of minimally invasive aortic valve surgery are to reduce the incision size and decrease the surgical trauma and pain, in addition to improving cosmetics, patient satisfaction, and recovery times. This must be realized without compromising the efficacy and the safety of the conventional aortic valve surgery.

Minimally invasive aortic valve surgery has been performed via several approaches such as a right parasternal incision, right anterolateral thoracotomy, and transverse sternotomy, but the most frequently performed approach is the partial upper sternotomy or “ministernotomy.” This latter approach allows excellent exposure for aortic root procedures and aortic valve replacement or repair. It is particularly useful for reoperative valve surgery and has been reported to decrease blood loss, transfusion requirements, wound complications, and total operative times compared with a full sternotomy technique. Contraindications to this technique are its use in high-risk and elderly patients, with significant coronary artery disease that needs to be corrected, and in the presence of chest wall deformities, cardiac malposition, and morbid obesity.

For the ministernotomy, transcutaneous defibrillator pads, a PA catheter, and TEE are used, and the patient is prepped in a supine position. After a 6- to 10-cm skin incision, a longitudinal midsternal cut is made from the notch to the third or fifth ICS, deviating to the right. Care is taken not to injure the internal thoracic vessels. Right femoral venous cannulation is performed, and with echocardiographic guidance, the cannula is advanced into the RA. Direct venous cannulation in the RA can also be done but reduces the surgeon’s exposure. Arterial cannulation is performed in the ascending aorta or in the femoral artery, and CPB is initiated. Both antegrade and retrograde cardioplegia are used for myocardial protection. After cross-clamping, antegrade cardioplegia is given either in the aortic root or directly into the coronary ostia and retrograde cardioplegia is delivered via a transjugular catheter directed into the coronary sinus. The aortic valve procedure is then performed as usual. After cross-clamp removal, intracardiac air is carefully monitored with TEE, the patient is weaned from CPB, and sternal closure is performed as usual.

The Brigham and Women’s Hospital surgeons reported their series of more than 500 mini-invasive aortic valve replacements with an operative mortality of 2% and a freedom from reoperation at 6 years of 99%.¹²

Minimally Invasive Mitral Valve Surgery

Developments in minimally invasive mitral valve surgery (MIMVS) started in the mid-1990s. Within a few years, with technologic advancements in instrumentation, assisted vision, and CPB support, conventional mitral valve surgery through a full sternotomy evolved to a totally endoscopic operation. This surgical evolution led to four levels of surgical invasiveness: (1) mini-incision and direct vision; (2) video-assisted and directed; (3) robot-directed; and (4) telemanipulation and robotically enhanced operations. These procedures are currently performed in several centers in the United States and Europe. Most suitable candidates are patients with primary valve disease, reoperative mitral valve disease, and obesity. Contraindications to these techniques are highly calcified mitral annulus, prior right-sided chest surgery, or significant coronary artery disease and peripheral vascular disease. In addition to improved cosmetics, these procedures are associated with less perioperative blood loss, fewer blood transfusions, shorter intubation time and length of stay, and faster recovery.

Level 1: Direct-Vision Minimally Invasive Mitral Valve Surgery

Direct-vision MIMVS can be performed through a ministernotomy, a parasternal incision, or through a limited anterolateral thoracotomy. CPB is instituted in a standard fashion or using the Port-Access system. Arterial cannulation is done through the femoral artery in the parasternal and in the limited thoracotomy approaches, but it can sometimes be accomplished directly in the ascending aorta in the lower partial sternotomy approach. Venous cannulation is accomplished by direct cannulation of the SVC (with a right-angled cannula) through the incision. The IVC is cannulated with a small percutaneous transfemoral cannula advanced over a guidewire and under guidance of TEE. The aorta is usually clamped through the incision. Finally, the mitral valve is approached either directly (standard left atriotomy) or transseptally via the RA.

The Brigham group published their experience of 1000 minimally invasive valve operations.¹² They performed 474 mitral procedures through a lower sternotomy, a right parasternal, or a right thoracotomy incision. They reported excellent results with operative and late mortality rates of 0.2% and 3.0%, respectively, and freedom from reoperation at 6 years was 95%. Compared with patients who had a full sternotomy incision, those who had a minimally invasive approach had shorter CPB and cross-clamp times, fewer myocardial infarctions, fewer pacemaker insertions, and a shorter length of stay (2 days).

Level 2: Video-Assisted and Video-Directed Minimally Invasive Mitral Valve Surgery

Video-assisted mitral valve surgery was developed to allow smaller incisions without compromising the results of the procedure and the patient’s safety. A telescope and a thoracoscopic camera are used to perform the surgery. The camera is manipulated by an assistant under the guidance of the surgeon. Mitral valve repair and replacement are performed using assisted vision through the thoracoscope.

Carpentier was the pioneer of video-assisted MIMVS. He and his group performed the first video-assisted mitral valve repair through a minithoracotomy using hypothermic ventricular fibrillation. Chitwood and his team modified the original technique, using a minithoracotomy, percutaneous transthoracic aortic occlusion, video assistance, and peripheral CPB.

Chitwood and colleagues reported their experience with 31 consecutive patients (20 mitral repairs and 11 replacements) with excellent results.¹³ Thirty-day mortality was 3.2%. No stroke or aortic dissection was reported. Compared with patients who had conventional mitral valve surgery, these patients had significantly shorter hospitalization times, less perioperative pain, and faster recovery. In addition, hospital charges were reduced.