Thoracoscopic internal mammary artery harvesting: technical considerations

Minimal invasive coronary surgery is not associated with increased mortality or morbidity during the period of learning curve

BACKGROUND

Minimally invasive procedures for coronary revascularization have been performed for over 20 years; however, their technical complexity, steep learning curves and absence of training programs explain the weak acceptance of these techniques. The aim of this study is to describe the step-by-step learning process on how to establish a minimally invasive coronary artery revascularization program. The short-term outcomes of our first 30 patients were compared to our left internal mammary artery (LIMA) to left anterior descending (LAD) artery off pump coronary artery bypass (OPCAB) cohort as a quality control baseline.

METHODS

All patients who benefited from an endoscopic atraumatic coronary artery bypass (Endo-ACAB) in our hospital, from July 2018 to May 2020 (n = 30) were identified. Baseline demographics, peri, postoperative and laboratory data were extracted from each patient's medical records. These results were compared to our LIMA-LAD OPCAB cohort (n = 23).

RESULTS

Twenty-eight patients were planned for a single LIMA-LAD Endo-ACAB. The remaining two had a T-graft double Endo-ACAB. Ten patients had a hybrid revascularization with the culprit lesion being treated first. Three patients were converted to sternotomy because of a LIMA lesion during thoracoscopic harvesting. We accounted three major adverse cardiovascular events (MACE). Demographic, peri and postoperative data showed no significant differences between the Endo-ACAB and the OPCAB group.

CONCLUSION

Endo-ACAB is a technically demanding operation, however, it can safely be introduced in centers with no previous experience with no extra cost in terms of morbidity or mortality. Thoracoscopic LIMA harvesting is the most demanding surgical skill to acquire.

Minimally invasive left internal mammary artery harvesting techniques during the learning curve are safe and achieve similar results as conventional LIMA harvesting techniques

Background

Internal thoracic arteries (ITAs) are considered to be the standard conduits used for coronary revascularization. Recently minimally invasive procedures are performed to harvest ITAs. The aim of this retrospective cohort study is to observe the effect and safety of less invasive LIMA harvesting approaches in the learning curve compared to conventional harvesting.

Methods

We retrospectively analyzed the data of 138 patients divided into three different groups based on the LIMA harvesting techniques: conventional sternotomy LIMA harvesting, CSLH (n: 64), minimally invasive direct LIMA harvesting, MIDLH (n: 42), and robotic-assisted LIMA harvesting, RALH (n: 32). The same 138 patients were also divided into sternotomy (n: 64), and non-sternotomy (n: 74) groups keeping both MIDLH and RALH in the non-sternotomy category. Parameters associated with LIMA’s quality and some other perioperative parameters such as harvesting time, LIMA damage, perioperative myocardial infarction, ventilation time, 24 h drainage, ICU stay, hospital mortality, computed tomographic angiography (CTA) LIMA patency on discharge, and after one year were recorded.

Results

The mean LIMA harvesting time was 36.9 ± 14.3, 74.4 ± 24.2, and 164.7 ± 51.9 min for CSLH, MIDLH, and RALH groups respectively (p < 0.001). One patient 1/32 (3.1%) in the RALH group had LIMA damage while the other two groups had none. One-month LIMA CTA patency was 56/57 (98.2%), 34/36 (94.4%), and 27/27 (100%) (p = 0.339), while 1 year CTA patency was 47/51 (92.1%), 30/33 (90.9%), and 24/25 (96%) for CSLH, MIDLH, and RALH groups respectively (p = 0.754). In the case of sternotomy vs non-sternotomy, the LIMA harvesting time was 36.9 ± 14.3 and 113.6 ± 59.3 min (p < 0.001). CTA patency on discharge was 56/57 (98.2%) and 61/63 (96.8%) (p = 0.619), while 1 year CTA patency was 47/51 (92.1%) and 54/58 (93.1%) (p = 0.850) for sternotomy vs non-sternotomy groups.

Conclusion

Minimally invasive left internal mammary artery harvesting techniques during the learning curve are safe and have no negative impact on the quality of LIMA. Perioperative outcomes are comparable to conventional procedures except for prolonged harvesting time. RALH is the least invasive and most time-consuming procedure during the learning curve. These procedures are safe and can be performed for selected patients even during the learning curve.

Hybrid Coronary Artery Revascularization: A Review and Current Evidence

OBJECTIVE

The role of hybrid coronary revascularization (HCR), which utilizes the combination of minimally invasive surgical coronary artery bypass grafting of the left anterior descending artery and percutaneous coronary intervention (PCI) of non-left anterior descending vessels to treat multivessel coronary artery disease, is expanding. We set out to provide a review of this technology.

METHODS

We conducted a retrospective analysis of all minimally invasive hybrid operations performed at our institution from September 2004 to December 2018. An effective analysis comparing patients undergoing HCR vs off-pump or on-pump surgical coronary artery revascularization was undertaken using an adjusted analysis with inverse-probability weighting based on the propensity score. Outcomes that were assessed include death, myocardial infarction, stroke, atrial fibrillation, renal failure, requirement of blood transfusion, conversion to open procedure (in the hybrid group), length of stay in intensive care unit, and total length of stay in hospital. Intention-to-treat analysis was performed. An up-to-date literature review of HCR complements this study.

RESULTS

Since 2004 a total of 191 consecutive patients (61.4±11.1 years; 142 males and 49 females) underwent HCR (robotic-assisted coronary artery bypass graft of the left internal thoracic artery to the left anterior descending coronary artery (LAD) and PCI of a non-LAD vessel) in a single- or double-stage fashion. Successful HCR occurred in 183 of the 191 patients (8 patients required intraoperative conversion to conventional coronary bypass). From our comparative analysis and literature review we found no significant difference between HCR and coronary artery bypass grafting groups with respect to in-hospital and 1-year follow-up.

CONCLUSIONS

Current evidences suggest that HCR is a feasible, safe, and effective coronary artery revascularization strategy in selected patients with multivessel coronary artery disease.

Robotic-assisted coronary artery bypass surgery: an 18-year single-centre experience

BACKGROUND

Minimally invasive robot-assisted direct coronary artery bypass (RADCAB) has emerged as a feasible minimally invasive surgical technique for revascularization that might offer several potential advantages over conventional approaches. We present our 18-year experience in RADCAB.

METHODS

Between February 1998 and February 2016, 605 patients underwent RADCAB. Patients underwent post-procedural selective graft patency assessment using cardiac catheterization.

RESULTS

The mortality rate was 0.3%. The rate of conversion to sternotomy for any cause was reduced from 16.0% of the first 200 cases to 6.9% of the last 405 patients. The patency rate of the LITA-to-LAD anastomosis was 97.4%. Surgical re-exploration for bleeding occurred in 1.8% of patients, and the transfusion rate was 9.2%. Average ICU stay was 1.2 ± 1.4 days, and average hospital stay was 4.8 ± 2.9 days.

CONCLUSIONS

Robot-assisted coronary artery bypass grafting is safe, feasible and it seems to represent an effective alternative to traditional coronary artery bypass grafting in selected patients.

Videothoracoscopic Internal Mammary Artery Harvest for Coronary Bypass

Between March 1996 and September 1997, videothoracoscopy was performed in 50 of 140 patients who underwent minimally invasive coronary artery bypass grafting. Mean age was 45.3 ± 6.8 years. The left internal mammary artery was harvested by thoracoscopy alone in 21 patients and by both thoracoscopy and direct vision in 29. Coronary artery bypass was then performed through a left anterior minithoracotomy. In 48 patients, the internal mammary artery was grafted directly to the left anterior descending artery; a small saphenous vein graft was interposed in the other 2 patients. The diagonal branch was bypassed with saphenous vein in 2 patients, the first obtuse marginal in 1, the right posterior descending branch in 1, and the right ventricular branch of the right coronary artery in 1. Concomitant carotid endarterectomy was performed in 1 patient. There was no mortality. Two patients had perioperative myocardial infarction. It was concluded that videothoracoscopy can help to achieve complete mobilization of the left internal mammary artery for minimally invasive coronary artery bypass grafting. These techniques can be regarded as safe and effective, giving excellent results and a shortened hospital stay with the advantage of avoiding some morbidity due to costal cartilage resection.

Defining the Learning Curve for Robotic-Assisted Endoscopic Harvesting of the Left Internal Mammary Artery

Objective

Robotic-assisted techniques are continuing to cement their role in coronary surgery, particularly in facilitating the endoscopic harvesting of the left internal mammary artery (LIMA), regardless of how the subsequent bypass grafting is performed. As more surgeons attempt to become trained in robotic-assisted procedures, we sought to better define the learning curve associated with robotic-assisted endoscopic LIMA harvest.

Methods

Between January 2011 and July 2012, a total of 77 patients underwent robotic-assisted minimally invasive direct coronary artery bypass surgery at our institution. The LIMA was harvested endoscopically in all patients, using standard robotic instruments, followed by direct grafting to anterior wall myocardial vessels via a small thoracotomy. Intraoperative times for various components of the procedure were collated and analyzed.

Results

The mean ± SD time taken to insert and position the ports for the robotic instruments was 3.9 ± 1.4 minutes. The mean ± SD LIMA harvest time was 31.8 ± 10.1 minutes, and the mean ± SD total robotic time was 44.2 ± 12.9 minutes. All time variables consistently continued to decrease as the experience of the operating surgeon increased, with the greatest magnitude of improvement being evident within the first 20 cases. The logarithmic learning curves for LIMA harvest time and total robot time during our entire experience were both calculated as 90%, correlating to an expected 10% improvement in performance for each doubling of cases completed.

Conclusions

Coronary surgeons can rapidly become proficient in robotic-assisted endoscopic LIMA harvest, with significant improvement in operative times evident within the first 20 cases completed. These data may be useful in designing appropriate training programs for newer surgeons seeking to gain experience in robotic-assisted coronary surgery.

Lessons learned from robotic-assisted coronary artery bypass surgery: risk factors for conversion to median sternotomy

OBJECTIVE

Robotic-assisted coronary artery bypass is a minimally invasive alternative to traditional coronary artery bypass surgery via median sternotomy with an associated learning curve. The purpose of this study was to investigate the reasons for conversion to sternotomy.

METHODS

From October 2009 to June 2012, two surgeons at one US academic institution performed 271 consecutive robotic-assisted coronary artery bypass procedures. For all cases, isolated, off-pump left internal mammary artery (LIMA) to left anterior descending coronary artery grafting was planned via a 3- to 4-cm sternal-sparing thoracotomy after robotic internal mammary artery harvest and pericardiotomy.

RESULTS

Conversion to sternotomy occurred in 15 of 271 (5.5%) patients. The most common reason was technical difficulty with the anastomosis, which occurred in 6 (40.0%) patients. Others included LIMA dissection, 2 (13.3%); wrong vessel grafted, 2 (13.3%); ventricular fibrillation and cardiac arrest, 1 (6.7%); equipment malfunction, 1 (6.7%); adhesions, 1 (6.7%); and other. Two underwent emergent conversion. Six underwent multivessel bypass after conversion instead of hybrid coronary revascularization. No mortality occurred among converted patients. Two patients had postoperative myocardial infarction and one had a superficial sternal wound infection. Conversion rate was relatively stable among the four different time quartiles (range, 3.0%-7.4%), although the reasons for conversion were different.

CONCLUSIONS

Conversion to sternotomy is an infrequent complication of robotic-assisted coronary artery bypass, most commonly because of technical difficulties during the LIMA harvest and the LIMA to left anterior descending anastomosis. Anatomic and patient variables as well as inherent technical problems with minimally invasive procedures make conversion unavoidable in some patients.

A semi-infinite programming approach to preoperative planning of robotic cardiac surgery under geometric uncertainty

In this paper, a computational framework for patient-specific preoperative planning of Robotics-Assisted Minimally Invasive Cardiac Surgery (RAMICS) is presented. It is expected that preoperative planning of RAMICS will improve the success rate by considering robot kinematics, patient-specific thoracic anatomy, and procedure-specific intraoperative conditions. Given the significant anatomical features localized in the preoperative computed tomography images of a patients thorax, port locations and robot orientations (with respect to the patients body coordinate frame) are determined to optimize qualities such as dexterity, reachability, tool approach angles and maneuverability. To address intraoperative geometric uncertainty, the problem is formulated as a Generalized Semi-Infinite Program (GSIP) with a convex lower-level problem to seek a plan that is less sensitive to geometric uncertainty in the neighborhood of surgical targets. It is demonstrated that with a proper formulation of the problem, the GSIP can be replaced by a tractable constrained nonlinear program that uses a multi-criteria objective function to balance between the nominal task performance and robustness to collisions and joint limit violations. Finally, performance of the proposed formulation is demonstrated by a comparison between the plans generated by the algorithm and those recommended by an experienced surgeon for several case studies.

A Step toward Nonrobotic Total Endoscopic Coronary Bypass Grafting: 40 Coronary Anastomoses in a Biomechanical Beating Heart Model

Objective

Nonrobotic total endoscopic coronary bypass grafting is commonly considered as technically too difficult. After endoscopic practicing in a simple box model, we questioned this statement in a more sophisticated training model.

Methods

In a handmade chest model containing a mechanically actuated porcine heart, anastomoses between homologous vein and shunted anterior coronary artery were performed using Prolene 7–0 sutures or U-clips in 20 anastomoses each. Commercially available endoscopic instruments and exclusive two-dimensional endoscopic vision were used. As quality control, the procedures were recorded, flow was measured, indocyanine green dye angiograms were performed, vinylpolysiloxane endocasts were produced, and finally the anastomoses were assessed from the endothelial side. Three-dimensional computed tomographic reconstruction was explored for cast measuring.

Results

All anastomoses were completed successfully in a time of 51 ± 14 minutes (Prolene) and 48 ± 10 minutes (U-clips). Despite suboptimal equipment, a reproducible sequence of the procedure was established and documented. Improving surgical performance was reflected in a reduction in anastomotic leakage and time requirement. The quality assessment protocol showed a learning curve and problems itself, which are briefly discussed.

Conclusions

A beating heart model is an adamant requirement of training for the technically demanding procedure of nonrobotic total endoscopic coronary bypass grafting. Refinement of the model and quality assessment as well as expansion of training to other regions of the heart should prepare for a cost-effective, broad-based clinical application of nonrobotic endoscopic techniques in coronary surgery. Available high-definition three-dimensional vision systems and the development of appropriate (articulating) instruments will make the procedure safer and quicker and will cut the learning curve.

Robotic Endoscopic Left Internal Mammary Artery Harvesting: What Have We Learned After 100 Cases?

BACKGROUND

The development of robotic devices has recently offered the possibility of performing coronary artery bypass graft surgery (CABG) in a totally endoscopic way. An important step of this procedure is endoscopic harvesting of the left internal mammary artery (LIMA). It was the aim of our study to find factors influencing LIMA harvesting time and to describe the challenges associated with robotic endoscopic LIMA harvesting.

METHODS

From June 2001 to December 2005, a total of 100 patients underwent robotically assisted CABG. In all cases, the LIMA was harvested by using the robotic DaVinci device. Coronary artery bypass grafting procedures were completed through sternotomy, minithoracotomy, or in a totally endoscopic fashion.

RESULTS

The median LIMA harvesting time was 48 minutes (19 to 180). A significant learning curve was observed: y (min) = 151 - 26 x ln (x), x = LIMA takedown number, p less than 0.001. Takedown time decreased from 140 minutes in the first 10 cases to 34 minutes in the last 10 cases. There was no independent demographic factor that significantly influenced the LIMA harvesting time. The LIMA takedown time also showed no significant correlation with thorax dimensions. Injury to the LIMA occurred in 3 patients (6%) during the first half of the experience and in 1 patient (2%) during the second half (p = not significant).

CONCLUSIONS

Robotic-enhanced LIMA takedown is a prerequisite for totally endoscopic CABG. After passing through a significant learning curve, IMA takedown can be performed safely and within an acceptable time frame. Demography and chest size do not seem to influence IMA harvesting time. The rate of LIMA injuries is within the limits of conventional thoracoscopic harvesting.

Prospective angiographic comparison of direct, endoscopic, and telesurgical approaches to harvesting the internal thoracic artery

BACKGROUND

The purpose of this study was to compare the quality of left internal thoracic arteries harvested by the conventional open approach versus minimally invasive videoscopic and robotic-assisted telesurgical techniques.

METHODS

One hundred and fifty consecutive patients with single vessel coronary artery disease were prospectively studied. The left internal thoracic artery was harvested using three different approaches, with 50 patients consecutively assigned to each group. The off-pump coronary artery bypass (OPCAB) group underwent median sternotomy with direct visualization. The automated endoscopic system for optimal positioning (AESOP) group employed the AESOP 3000 system (Computer Motion Inc, Goleta, CA) for robotic-assisted visualization with endoscopic manual left internal thoracic artery harvesting. The Zeus group used the Zeus robotic telesurgical system (Computer Motion Inc) and internal thoracic artery harvesting was performed remotely from a surgical console. Postanastomotic left internal thoracic artery flows and day one postoperative angiography were used to assess internal thoracic artery quality and patency.

RESULTS

Average left internal thoracic artery harvest times were 23 +/- 2.5, 63.3 +/- 20.3, and 66.1 +/- 17.9 minutes in the OPCAB, AESOP, and Zeus groups, respectively (p < 0.001, OPCAB vs AESOP and Zeus). Intraoperative graft flows averaged 28.1 +/- 11.9, 33.7 +/- 19.3, and 36.9 +/- 24.6 mL/minute, respectively in the OPCAB, AESOP, and Zeus groups (p = 0.317, OPCAB vs AESOP and Zeus). There was no significant angiographic difference in the patency rate of the harvested left internal thoracic arteries in the three groups (p = 0.685, overall).

CONCLUSIONS

The left internal thoracic artery can be harvested safely and effectively using minimally invasive videoscopic and robotic-assisted telesurgical techniques. Although the less invasive approaches require specialized equipment and training as well as increased operative time, they offer the potential for less traumatic myocardial revascularization through smaller incisions and reduced postoperative morbidity.

Technical challenges in totally endoscopic robotic coronary artery bypass grafting

OBJECTIVE

Robotic technology is a prerequisite for performance of totally endoscopic coronary artery bypass grafting. During the implementation phase of totally endoscopic coronary artery bypass, surgeon-related technical difficulties might be encountered. It was the aim of this study to assess the incidence of these challenges, to find risk factors, and to describe clinical results associated with technical errors.

METHODS

From October 2001 through October 2004, 40 patients received robotically assisted totally endoscopic left internal thoracic artery grafts to the left anterior descending coronary artery system with the da Vinci telemanipulation device. All patients underwent remote access cardiopulmonary bypass perfusion through groin access, and all anastomoses were performed on the arrested heart.

RESULTS

Undesirable technical events of various grades occurred in 20 (50%) of 40 patients: bleeding from a port hole in 3 (8%), left internal thoracic artery damage in 3 (8%), epicardial lesion in 3 (8%), remote access perfusion problems in 9 (23%), bleeding from the anastomosis in 4 (10%), and anastomotic stenosis in 2 (5%). There was no hospital mortality. The following differences were noted between patients without technical difficulties (group 1) and those in whom problems occurred (group 2): total operative time of 314 minutes (260-540 minutes) versus 418 minutes (270-690 minutes; P = .007), ventilation time of 6 hours (0-26 hours) versus 14 hours (0-278 hours; P = .004), intensive care unit stay of 20 hours (11-70 hours) versus 44 hours (16-336 hours; P=.183), hospital stay of 7 days (4-13 days) versus 8 days (5-21 days; P = .038), and cumulative freedom from angina at 36 months of 93% versus 100% (P = .317).

CONCLUSION

We conclude that technical difficulties during totally endoscopic coronary artery bypass grafting translate into markedly increased operative time, moderately prolonged postoperative ventilation time, and slightly increased hospital stay. Short-term survival and freedom from angina, however, do not seem to be compromised.

Brachial plexus injury as an unusual complication of coronary artery bypass graft surgery

Brachial plexus injury is an unusual and under-recognised complication of coronary artery bypass grafting especially when internal mammary artery harvesting takes place. It is believed to be due to sternal retraction resulting in compression of the brachial plexus. Although the majority of cases are transient, there are cases where the injury is permanent and may have severe implications as illustrated in the accompanying case history.

Primary stenting versus MIDCAB: preliminary report-comparision of two methods of revascularization in single left anterior descending coronary artery stenosis

BACKGROUND

Percutaneous revascularization is a well-accepted method of treatment for a single left anterior descending coronary artery (LAD) stenosis. With the introduction of primary stenting, it has become the treatment of choice for a LAD lesion. In the last few years however, the introduction of minimally invasive cardiac surgery, video-assisted left internal thoracic artery (LITA) harvesting, and robotic surgery have raised the question as to whether minimally invasive surgical revascularization would be competitive with percutaneous coronary interventions in cases of single-vessel stenoses.

METHODS

A group of 100 patients with Canadian Cardiovascular Society class II to IV, and angiographically confirmed single critical stenosis of the LAD (type A or B), were treated with direct primary stenting (group 1, n = 50), or with endoscopic atraumatic coronary artery bypass grafting (group 2, n =50).

RESULTS

All patients in a group 1, obtained a very good angiographic and clinical effect. No acute postoperative complications were noted at 1 month of follow-up. However, at 1 month of follow-up, 3 patients (6%) developed restenosis of the LAD, and at 6 months follow-up, 6 patients (12%), developed restenosis of the LAD. In these cases, repeated percutaneous coronary interventions of the target vessel were successfully performed. In group 2, very good operative results were observed. In 1 and 6 months of follow-up, all patients remained asymptomatic. Critical stenosis of the left internal thoracic artery-LAD anastomosis was angiographically documented in 1 case (2%). This patient was successfully treated with balloon angioplasty.

CONCLUSIONS

The study results document the superiority of endoscopic atraumatic coronary artery bypass grafting over direct primary stenting in LAD revascularization, along with the slightly higher costs of the surgical procedure.

Thoracoscopic internal mammary sentinel node biopsy: an animal model of a new technique

BACKGROUND

The nodal status remains the most important prognostic factor in breast cancer. While evaluation of the axillary lymph nodes remains a standard of practice, evaluation of the internal mammary lymph nodes is no longer routinely performed. In the era of extensive radical mastectomies, it was shown that up to 40% of breast cancer patients had nodal metastases in the internal mammary chain. This resulted in up to 10% of presumed "node-negative" patients actually being node-positive when the internal mammary nodes were examined. In the era of sentinel node biopsies, hot internal mammary nodes on lymphoscintigraphy are sometimes encountered and confusion exists regarding the appropriate approach to these nodes. New advances in endoscopic surgery have enabled a minimally invasive approach to the mediastinum. The aim of this study was to evaluate the feasibility of thoracoscopic internal mammary sentinel node biopsy in an animal model.

MATERIALS AND METHODS

Five farm pigs were injected with isosulphan blue under the right upper nipple. After a sentinel node was identified, it was dissected thoracoscopically.

RESULTS

In all the animals, an internal mammary blue node was easily identified 1-5 min after the injection and dissected with thoracoscopic instruments without significant damage to other thoracic structures. The procedure length averaged 30 to 60 min.

CONCLUSIONS

Thoracoscopic internal mammary sentinel node biopsies are feasible, short, easy to perform, minimally invasive, and well focused toward a sentinel node. Well-planned phase I studies should be initiated to further evaluate this new technique.

Anaesthesia for minimally invasive cardiac surgery

Minimally invasive cardiac surgery is used for both extracardiac and intracardiac procedures. Extracardiac procedures, such as coronary artery bypass grafting, are often performed on a beating heart. Intracardiac procedures are done with the aid of cardiopulmonary bypass. The surgery is performed via a minithoracotomy or a ministernotomy. Thoracoscopic video-assisted surgery, often with robotic assistance, necessitates prolonged one-lung ventilation to optimize exposure. Port-access surgery will require appropriate positioning of various catheters to establish cardiopulmonary bypass. Adequate flow during cardiopulmonary bypass may require suction augmentation of venous return and may increase the risk of air emboli. Limited exposure of the heart during surgery poses challenges with management of arrhythmia, haemostasis, myocardial protection and de-airing at the end of surgery. Patient selection is important to avoid intra-operative and post-operative complications. Prolonged single-lung ventilation, incomplete revascularization in hybrid procedures, and limited access for rapid intervention pose challenges with patient management. Conversion to sternotomy that may be required occasionally and extension of portals over several dermatomal segments mandate a versatile analgesic technique.

Early experience with robotically assisted internal thoracic artery harvest

We sought to determine the efficacy of using robotic assistance to facilitate endoscopic harvesting of internal thoracic arteries (ITAs). A total of 104 patients had ITAs harvested endoscopically with use of both the AESOP 3000 system (Computer Motion, Goleta, CA, U.S.A.) and Zeus robotic telesurgical system (Computer Motion). All ITAs were harvested with a harmonic scalpel (Ethicon Endosurgery, Cincinnati, OH, U.S.A.). With the left lung collapsed, ITAs were harvested with CO2 insufflation through three 5-mm ports in the left chest. All patients tolerated insufflation without hemodynamic compromise. Average ITA harvest time was 61.3 +/- 20.9 minutes. Intraoperative graft flows averaged 36.3 +/- 22.4 mL/min. There were three distal ITA injuries; all other vessels were patent after harvesting and demonstrated no angiographic evidence of injury. This article demonstrates a technique by which ITA can be safely harvested totally endoscopically with use of computer-enhanced robotic systems and a harmonic scalpel, allowing complete pedicle dissection through 5-mm ports with minimal ITA manipulation.

Thoracoscopic Internal Thoracic Artery Harvest: Angiographic Assessment

Minimally invasive direct coronary artery bypass grafting was carried out in 10 patients. The left internal thoracic artery was mobilized under direct vision in the first 5 and by thoracoscopy in the next 5. Postoperative arteriography confirmed the advantage of thoracoscopic arterial harvest. The length of the thoracoscopically harvested artery was 10 ± 2 cm compared to 6 ± 1 cm for grafts harvested under direct vision (p < 0.05). The anastomotic angle between the internal thoracic artery and the left anterior descending coronary artery was 43° ± 4° for thoracoscopically harvested grafts versus 62° ± 5° for the direct vision method (p < 0.05). One anastomotic complication (occlusion) was found in a patient who had arterial harvest under direct vision. Internal thoracic artery harvested by thoracoscopy diverges from the chest wall and runs directly to the anastomotic site. Such a conduit harvested by direct vision runs along the chest wall until near the anastomotic site, which might increase the risk of anastomotic complications.

Anesthesia and Regional Anesthetic Techniques for Minimally Invasive Direct Coronary Artery Bypass Surgery

An innovative new approach to coronary revasculariza tion, minimally invasive direct coronary artery bypass is performed via a small anterior minithoracotomy or ministernotomy on a beating heart without the aid of cardiopulmonary bypass. Components of this tech nique, including thoracoscopic video-assisted harvest ing of the internal mammary artery, often with har monic scalpel and potentially even robotic assistance, necessitate prolonged one-lung ventilation. In the ab sence of cardioplegia, myocardial protection during normothermic beating heart surgery poses a challenge. Patient selection is important to avoid intraoperative and postoperative complications. Prolonged single- lung ventilation, incomplete revascularization in hybrid procedures, and limited access for rapid intervention pose challenges with patient management. Conversion to sternotomy may be required in 5% to 7% of patients, and extension of portals over several dermatomal seg ments mandate a versatile analgesic technique. Re gional anesthesia as analgesic adjuvant allows lighter levels of general anesthesia during surgery with mini mal intraoperative hemodynamic changes and a smooth transition to postoperative analgesia. Although a num ber of regional techniques may be used to achieve this goal, thoracic epidural analgesia or continuous percuta neous paravertebral block seem to offer specific advan tages of cardiac sympathectomy.

Thoracoscopic IMA takedown

In recent years, the field of minimally invasive cardiac surgery has grown rapidly beginning with the MIDCAB operation and evolving toward totally endoscopic coronary artery bypass grafting (CABG). It promotes the goal of decreasing surgical trauma while maintaining surgical efficacy. For MIDCAB, a limited anterior thoracotomy or mediastotomy have been proposed to harvest the internal mammary artery (IMA). However, complete graft harvesting of the IMA is difficult under direct vision in these circumstances and may necessitate costal resection and important chest wall retraction. Additionally, it carries the potential risk of kinking or coronary steal syndrome. Thoracoscopic harvesting of the IMA avoids these hazards. It permits complete dissection from the subclavian artery to the sixth inter-costal space (ICS) with section of all collateral branches issuing from the IMA without any traumatic retraction. The technique of IMA takedown described herein has been used regularly by us since 1995. Our current experience shows that it is safe and reproducible after a reasonable period of training. Furthermore, in the objective of performing a totally endoscopic and/or robotic CABG, thoracoscopic IMA takedown would be a prerequisite.

Initial United States clinical trial of robotically assisted endoscopic coronary artery bypass grafting

OBJECTIVES

With traditional instruments, endoscopic coronary artery bypass grafting has not been possible. This study was designed to determine the clinical feasibility of using a robotically assisted microsurgical system to create endoscopic coronary anastomoses.

METHODS AND RESULTS

Ten patients underwent endoscopic coronary artery bypass grafting of the left internal thoracic artery to the left anterior descending artery. Subxiphoid endoscopic ports (2 for instruments, 1 for a camera) were placed, and a robotic system was used to perform the left internal thoracic artery-left anterior descending artery bypass graft. Conventional techniques were used to perform the other grafts. Blood flow through the left internal thoracic artery graft was measured in the operating room and was adequate in 8 of 10 patients. The 2 inadequate grafts were revised successfully by hand. Six weeks after the operation, selective coronary angiography demonstrated a graft patency of 100% (8/8). There were no technical failures of the robotic system. The only postoperative complication was mediastinal hemorrhage in 1 patient.

CONCLUSIONS

This pilot study demonstrates the feasibility of robotically assisted endoscopic coronary artery bypass grafting.

Total endoscopic computer enhanced coronary artery bypass grafting

OBJECTIVE

In an effort to minimize access in coronary artery bypass (CAB) surgery, a total endoscopic approach using computer enhanced technology was developed.

METHODS

By July 1999 the da Vinci telemanipulation system (Intuitive Surgical, Mountain View, CA) was used in 66 patients with coronary artery disease. In 12 patients undergoing routine coronary artery bypass grafting (CABG) (group 1) the internal thoracic artery (ITA) to left anterior descending artery (LAD) anastomosis was performed remotely using the system. In 32 patients (group 2) endoscopic dissection of the ITA was performed followed by a conventional minimally invasive direct coronary artery bypass (MIDCAB) operation. In 22 patients (group 3) the complete operation was performed endoscopically through 4 ports (total endoscopic coronary artery bypass, TECAB). Port-Access cardiopulmonary bypass with cardioplegic arrest was used for TECAB.

RESULTS

In group 1 the time for performing the ITA to LAD anastomosis was 17 +/- 10 min. Mean graft flow was 38 +/- 25 ml/min. One anastomosis leaked and was repaired manually. In group 2 in 31/32 patients (96%) the ITA harvest was successfully performed with the system at mean of 61 +/- 27 min. There was a substantial learning curve associated with ITA take-down. In one patient a dissection caused insufficient free ITA graft flow which necessated additional vein grafting. Postoperative angiography demonstrated graft patency in all cases. In the TECAB group, the operation could be completed through four ports in 18 of the 22 patients (82%) with operating times in the range 220-507 min. In four patients, elective conversion to a minithoracotomy was required due to failure to identify the LAD (1), bleeding from the anastomosis (1), grafting of a diagonal branch (1) and torsion of the pedicle (1). One patient required reoperation for bleeding from an ITA side-branch. Median intubation time was 13 h and stay on ICU and hospitalization were 20 h and 7 days, respectively. A 3-month follow-up angiography revealed patent grafts in all TECAB patients.

CONCLUSION

Endoscopic ITA harvesting and performing of arterial anastomoses can be safely performed with the da Vinci system. TECAB is possible on the arrested heart with good functional results. However, a substantial learning curve has to be overcome which is reflected in long operation times and an initial significant conversion rate.

Potential risks in coronary artery bypass grafting via mini-thoracotomy: a case report

This paper describes a patient with an occluded left internal thoracic artery, possibly as a result of the proximal 'steal phenomena', following coronary artery bypass grafting via mini-thoracotomy without cardiopulmonary bypass.

Left internal mammary artery grafting to left anterior descending coronary artery by minimally invasive direct coronary artery bypass approach

New surgical techniques for the treatment of the isolated lesion of the left anterior descending coronary artery (LAD) include off-pump surgery, minimal access to the heart, and endoscopic or computer enhanced coronary artery bypass surgery. The term minimally invasive direct coronary artery bypass surgery (MIDCAB) is related to a left-side minithoracotomy, the harvest of the left internal mammary artery (IMA) under direct vision, and an anastomosis performed between IMA and LAD under direct vision, using the technique of mechanical local immobilization by a special device. Alternative techniques include endoscopic harvesting of the IMA, or as a new and still experimental approach, the closed-chest total endoscopic coronary artery bypass grafting (TECAB) with the use of a high tech telemanipulator system. The currently reported results demonstrate the safety of MIDCAB surgery (30-day mortality < 0.5%, perioperative myocardial infarction < 2%, early patency rate between 95% and 98%). Mid-term results after 6 months have shown a patency rate between 94% and 97%, and more than 90% of the patients are without any angina symptoms. Due to this promising results MIDCAB is an alternative treatment for high-grade LAD lesions.

Patient selection for Port-Access multi vessel revascularization

Minimally invasive multivessel revascularization is rarely performed due to the difficult exposure of the aorta as well as the complete coronary anatomy through a small thoracotomy. The Port-Access technique bears additional contraindications for this procedure, which limits its potential as compared with other approaches to 'less invasive surgery'. Our aim was to show the applicability of this surgical technique to a wide range of patients with coronary artery disease. In our initial experience with this method (31 patients), the quality of anastomoses, graft patency, and clinical outcome are good, and do not differ from standard multivessel coronary artery bypass grafting. Port-Access multivessel revascularization can be performed safely and is appropriate for a large patient population.

Endoscopic coronary artery bypass grafting with the aid of robotic assisted instruments

OBJECTIVE

The development of endoscopic coronary artery bypass grafting has been limited because of poor visualization and increased technical difficulties in carrying out operations through ports. We investigated whether the use of robotic assisted instruments could minimize these difficulties.

METHODS

After a period of technical development and training on cadavers (n = 8) with the Intuitive Surgical system (Intuitive Surgical, Inc, Mountain View, Calif), the first clinical application in coronary artery surgery was performed in 4 male patients (mean age 59 +/- 6 years) with the indication of grafting the left internal thoracic artery to the left anterior descending coronary artery. Robotic assisted 3-dimensional endoscopes and instruments were introduced into the left side of the chest through 3 intercostal ports. The Heartport system (Heartport, Inc, Redwood City, Calif) was used for arresting the heart during the anastomosis.

RESULTS

In 2 patients, the harvesting of the left internal thoracic artery was completed endoscopically with robotic assisted instruments and the anastomosis to the left anterior descending artery was performed through a minithoracotomy with conventional instruments. In 2 other patients, the entire operation was completed endoscopically with robotic assisted instruments. Early postoperative coronary angiography demonstrated the patency of the grafts in all cases. At 6-month follow-up, all patients were free of symptoms.

CONCLUSIONS

Robotic assisted instruments make endoscopic coronary bypass possible and open a new era in minimally invasive surgery.

Video-assisted coronary artery bypass in patients with preexisting tracheostomy

A new technique allowing revascularization of the left coronary artery through a small thoracotomy after videoscopic harvesting of both mammary arteries is proposed in patients with total laryngectomy. This anterior thoracotomy approach, of real interest in patients with a preexisting tracheostomy, needs to be compared with a classic sternotomy in terms of functional recovery and the prevention of mediastinal sepsis in certain high-risk categories of patients (e.g., obesity, diabetes) for bilateral mammary artery harvesting.

Video-assisted minimally invasive coronary bypass surgery without cardiopulmonary bypass

BACKGROUND

There is a growing interest in cardiac surgery towards minimally invasive approach to coronary bypass operations without cardiopulmonary bypass.

PATIENTS AND METHODS

From March 1995 to March 1997, 41 patients underwent a single left internal mammary artery (LIMA) to the left anterior descending artery (LAD) coronary grafting without cardiopulmonary bypass through a small left anterior thoracotomy (MIDCABG). The mean age was 61.2+/-8.7 years (range 43-77 years), 28 patients. were male (68.2%) and the redo rate was 4.8% (2/41). In all patients the coronary artery disease involved the LAD, which was occluded in seven patients (17.1%). Thirty-eight patients (96.2%) selected for MIDCABG had a monovascular disease on LAD not suitable for percutaneous coronary angioplasty; two (4.8%) a bivascular disease, and one (2.4%) a trivascular disease. Skin incision was performed in the 4th anterior intercostal space from the left parasternal line for a 10.5 cm length on average. The LIMA harvesting was partially video-assisted by thoracoscopy.

RESULTS

The LAD temporary occlusion was achieved with two double 5/0 polypropilene round-LAD sutures. The mean LAD ischemic time was 22+/-8 min (range 4-35 min). No thoracotomy procedure was changed into a sternotomy approach. We had one (2.4%) perioperative AMI; two patients (4.8%) were reoperated for bleeding. All patients underwent a postoperative angiographic reinvestigation within 1 month after surgery. All anastomoses were perfectly patent but two (4.8%). One patient was reoperated via a sternotomy access recycling the LIMA graft, the other one underwent successful PTCA. All patients also underwent an early and mid-term (6 months after surgery) echo-Doppler study of the LIMA flow and patency. At follow-up, performed at a mean of 8.7 months (range 1-23) after discharge, all patients were alive; no one experienced recurrence of angina. All patients also performed a mid-term negative treadmill stress test.

CONCLUSIONS

MIDCABG is, in selected patients, reliable and safe, and offers encouraging early and mid-term clinical results.

Minimally invasive coronary artery bypass grafting: on the beating heart and via limited access

Minimally invasive coronary artery bypass grafting (MICABG) may be achieved by arterial grafting on the beating heart, without cardiopulmonary bypass, and by operations via limited access. The Second Utrecht MICABG Workshop held October 4-5, 1996, focused on beating-heart coronary immobilization, limited-access thoracoscopic and direct-vision mobilization of the internal mammary artery, limited-access left anterior descending coronary artery grafting, and, finally, facilitated distal anastomosis techniques. It has yielded 33 reports in this supplement. The combined, cumulative experience of a number of participants exceeded 3,000 beating-heart cases, including more than 1,000 with arterial grafting through limited access. The average number of anastomoses per patient ranged from 1.0 to 2.0. Therapeutic strategies are evolving, and dedicated instrumentation is being developed. Randomized clinical trials with angiographic follow-up are required to establish that the reduction in invasiveness of coronary bypass grafting is not achieved at the expense of suboptimal quality of the arterial graft and the distal anastomosis.