Mid-term results and patient perceptions of robotically-assisted coronary artery bypass grafting
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《血管的通路杂志》
a Division of Cardiothoracic Surgery, St. Luke's-Roosevelt Hospital Center, 1111 Amsterdam Avenue, MU-217, New York, NY 10025, USA
b Department of Surgery, St. Luke's-Roosevelt Hospital Center, New York, NY 10025, USA
c Division of Cardiology, Department of Medicine, St. Luke's-Roosevelt Hospital Center, New York, NY 10025, USA
Presented at the 7th Annual Scientific Meeting of the International Society of Minimally Invasive Cardiothoracic Surgery, London, England, June 2004.
Abstract
We sought to study our mid-term outcomes and our patient's perceptions of robotically-assisted coronary artery bypass (RACAB). The daVinciTM robotic system was utilized to harvest and prepare the internal thoracic artery (ITA) as well as to open the pericardium and identify the target vessels. Anastomoses were performed by hand on the beating heart through limited incisions using an endoscopic stabilizing device. A follow-up telephone interview was conducted with patients at 3 to 6 months. Between 4/12/02 and 11/1/04, 37 patients underwent RACAB (1.2 distal anastomoses/patient). Median length of stay was 3 days (2–14 days) and 82% of patients reported full return to baseline activity within 10 days of surgery. There were two early LITA complications and one late anastomotic stenosis all of which occurred within the first two cases of each surgeon's experience. The majority of patients surveyed (95%) knew that robotics were involved in their surgery and most patients (95%) would recommend RACAB (95%). RACAB is an effective minimally invasive revascularization technique with excellent recovery times and high patient satisfaction. The early complication rate emphasizes the steep learning curve for this procedure as well as the need for intensive pre-procedure training.
Key Words: Robotic surgery; Coronary artery bypass grafting; Off-pump surgery
1. Introduction
Minimally invasive approaches to coronary artery revascularization range from off-pump coronary artery bypass grafting (OPCAB) through a sternotomy, to totally endoscopic coronary artery bypass grafting (TECAB) using robotic facilitation [1–4]. Whereas OPCAB has become an easily reproducible procedure with fairly widespread surgeon adoption, TECAB on both the beating and arrest heart has been plagued by high technical demands with a steep and long learning curve.
Traditional mid-CAB has met with an adoption level between both OpCAB and TECAB [5]. However, significant post-operative pain secondary to chest wall retraction during left internal thoracic artery (LITA) mobilization, as well as wound complications, have left many surgeons unhappy with the minimally invasive nature of this procedure [6,7]. Endoscopic LITA mobilization with a non-rib spreading thoracotomy and open coronary anastomosis (endo-ACAB) has been performed with excellent results [8]. This procedure has failed to gain widespread acceptance because of the technical demands of endoscopic LITA mobilization. The facilitating technology of robotics promises to decrease the learning curve associated with endoscopic LITA harvest. Simultaneously, the advantages of non-rib spreading, open, beating heart surgery might be retained with robotically-assisted CABG (RACAB).
We sought to evaluate our mid-term results with RACAB in order to validate its efficacy and carefully study the procedure's learning curve. We also hoped to understand patient's perceptions of RACAB as well as their satisfaction level.
2. Materials and methods
An IRB-approved database was established for the prospective evaluation of all patients undergoing RACAB. Exclusion criteria included emergency status, moderate to severe valvular disease, decompensated congestive heart failure, endocarditis, and acute renal failure. All patients undergoing RACAB at our institution over the study period were enrolled and this report represents the first 37 patients undergoing the procedure.
The daVinciTM robotic system was utilized in all cases. The pericardium was opened and target vessels were identified. This allowed for assessment of conduit length, target vessel anastomotic site and the presence of target vessel intra-myocardial course. The LITA was then dissected in a semi-skeletonized fashion by mobilizing the artery and vein together without associated muscle or fascia.
The camera port site was extended and the 4th or 5th intercostal space was opened. A soft tissue retractor was placed (Fig. 1). An endoscopic stabilizer (Medtronic, Minneapolis, MN) was introduced through the left arm port and the heart was positioned (Fig. 2). The anastomoses were then performed by hand on the beating heart.
All patients underwent nuclear stress testing at 3 months. Follow-up angiography was performed only if the patient reported symptoms or if there were new reversible defects on routine stress testing. A short questionnaire was conducted via phone 3–6 months following discharge.
All data are presented as the mean±standard deviation. Discrete variables were compared using the chi-square test and continuous variables were compared using the Mann-Whitney test.
3. Results
Between 4/12/02 and 11/1/04, 37 patients underwent RACAB. Thirty-five operations were performed by one surgeon (J.D.) and two operations were performed by another surgeon (D.S.). The pre-operative patient characteristics are listed in Table 1. Indications for surgery are listed in Table 2. The most common indication for RACAB was as part of a hybrid revascularization (51%). Among patients undergoing hybrid revascularization, 11 patients received a percutaneous intervention to a single vessel and 8 patients had a percutaneous intervention to more than one vessel. All patients undergoing hybrid revascularization underwent the percutaneous intervention first. RACAB was then performed between 1 to 30 days later. Clopidogrel was used in every hybrid revascularization up until the date of surgery. Twenty-seven (73%) patients underwent small anterior thoracotomy and 9 (24%) underwent lower hemi-sternotomy into the left 3rd interspace.
One obese diabetic patient with a very small circumflex system and a tight ostial LAD with a long left main vessel was chosen for single vessel RACAB through a non-rib spreading anterior thoracotomy. The patient undergoing partial revascularization was a 61-year-old woman with insulin dependent diabetes mellitus, a prior left below knee amputation, who did not ambulate and was admitted with a gangrenous right foot and required peripheral vascular surgery. Because of the patient's frail pre-operative status, limited ambulation and lack of appropriate conduit, it was elected that a single vessel RACB would be performed.
Successful LITA takedown was performed in all patients except one. This patient was the second patient in our RACAB experience and he had an LITA dissection. The patient underwent uneventful conversion to sternotomy. His pedicled RITA was mobilized in the conventional manner and was used to bypass the left anterior descending artery (LAD). A total of 43 distal anastomoses were performed (1.2/case). Six patients underwent more than one distal anastomosis and these specific configurations are displayed in Table 3. The patient undergoing pedicled RIMA anastomosis to his LAD, and LIMA anastomosis to his diagonal, had isolated LAD/diagonal disease. His diagonal vessel was a large lateral vessel and the anatomic arrangement was not amenable to sequential grafting with the LIMA. The patient undergoing LIMA-LAD grafting and saphenous vein grafting to the right coronary artery (RCA) had ostial RCA and ostial LAD lesions. The LIMA was mobilized robotically and the coronary grafting was then performed off-pump through a lower hemisternotomy.
Post-operative complications included one wound infection and one reoperation for bleeding. The wound infection occurred in a morbidly obese diabetic woman with very large breasts who underwent a limited anterior thoracotomy. The bleeding episode that required re-operation resulted from an intercostal branch in the robotic left arm port. Three patients (8%) had a limited episode of atrial fibrillation. Only three patients (8%) with low pre-operative hematocrits (25%, 28% and 27%) required blood transfusions after surgery. One patient who underwent a pre-operative right coronary artery stent had acute stent occlusion on the first post-operative night that required emergency repeat percutaneous intervention.
Median length of stay was 3 days (2–17 days) and 82% of patients reported full return to baseline activity within 10 days of surgery. All patients were discharged to their home with the exception of one 84-year-old woman who went to inpatient rehabilitation. At a mean follow-up of 16.1±8.4 months (3–31 months), all patients are alive and well and chest pain free. During this follow-up period, 10 patients underwent repeat coronary angiography (post-operative day 0 to 13 months post-op). There was one anastomotic stenosis detected at 13 months. A second patient returned with an LITA stenosis which required percutaneous intervention and subsequent re-operation. The seven other patients undergoing angiography had widely patent anastomoses. Of the three LITA-LAD complications (1 LITA injury, 1 mid- LITA stenosis and 1 anastomotic stenosis), all occurred within the first two cases of each surgeon's experience.
There have been no deaths over the follow-up period and no patient has had a myocardial infarction. Of the 15 patients undergoing hybrid revascularization, three required repeat percutaneous intervention. Two patients had instent restenosis and a third patient presented with a new ramus lesion which required a stent.
Of the 37 patients undergoing RACAB, 20 patients completed the 19-question phone survey (Table 4). The majority of patients correctly identified their diagnosis (80%), the procedure they were undergoing (80%) and the organ that was being operated upon (95%). All patients were satisfied (100%) and understood the information (100%) provided by their surgeons. Most patients knew that the robot was involved in their operation (95%). When asked who actually performed the operation, the responses were ‘surgeon’ (68%), ‘both’ (11%), ‘robot’ (5%), and ‘don't know’ (16%). Most patients felt they benefited from robotic surgery as opposed to the traditional open method (84%). Shorter recovery time, smaller scar, and less invasive were the most common benefits mentioned. No statistically significant difference was seen based on educational experience or annual income.
4. Discussion
The first reports describing the use of robotics in myocardial revascularization appeared in the literature in 1999 [9,10]. In an attempt to make the leap to ‘outpatient’ and ‘no incision’ CABG, cardiac robotic surgeons have investigated the development of TECAB. As part of the learning curve, those in both Europe and the United States started with the ‘intermediary’ step of arrested heart TECAB [1,4]. Although some had early success, complications with endoaortic balloon occlusion and cardiopulmonary bypass as well as early LITA injuries left many unfulfilled with this procedure. Furthermore, not only was training in robotic skills necessary, but extensive experience with minimally invasive CPB techniques was also a pre-requisite for the success of this procedure. In order to remove this layer of complexity, some surgeons have begun programs to perform beating heart TECAB [10,11]. Although some groups have reported impressive initial success, the technical demands of this procedure thus far have proved to be a significant barrier to its wide adoption.
The robot is a tool to aid the minimally invasive cardiac surgeon in a variety of techniques. When viewed in this manner, RACAB becomes the logical extension of the more time-tested procedures of mid-CAB and endoscopic-assisted coronary artery bypass (endo-ACAB). The three-dimensional vision and computer interface of robotics makes both vessel identification and IMA mobilization quicker and easier than if performed with either a mid-CAB retractor or a thoracoscope. The endoscopic stabilizer used in these operations greatly enhances operating space through either rib-spreading or non-rib spreading thoracotomies. Although originally designed for TECAB, its application in RACAB has served to minimize the size of the anterior thoracotomy incision. The stabilization provided is via both suction and compression and works well for anterior vessels. An endoscopic suction cup needs to be added in order to be able to graft lateral wall vessels through this incision.
Despite its relative ease of adoption, RACAB is not without a learning curve. Learning to use visual clues for tactile feedback and becoming comfortable with the anterior thoracotomy approach seem to be important steps in mastering this operation. Novick has previously demonstrated the learning curve that exits for robotic LITA mobilization by measuring operative times and complications [11]. Although intuitive for any type of learning process, our study corroborates these findings with respect to our early complications. When the early learning curve is eliminated (i.e. the first two cases of each surgeon's experience), no anastomotic complications or LITA injuries were encountered in this series. These results are similar to prior large series of endo-ACAB [8] and mid-CAB [5].
The ability to avoid morbidities may lie in specific skill-based learning. As no robotic skill development training currently exists, there is also no specific credentialing process required to begin a robotic cardiac surgery program. We and others continue to work to develop such standardized training programs for robotic skills [12]. In the interim, an internal plan for surgeon training is necessary to master the RACAB procedure. Extensive experience with sternal sparing off-pump surgery does make this transition simpler. However, specific robotic skills should be mastered on both inanimate and animate models prior to performing procedures in human subjects. Although sometimes time-consuming and difficult, we would recommend robotic LITA takedown, LITA preparation, and coronary vessel identification with planned conversion to sternotomy in a number of cases prior to performing a sternal-sparing RACAB. The lower hemi-sternotomy was used by our group for our first six cases as an intermediary step in the progression towards limited anterior thoracotomy. This approach allows for open takedown of the distal LITA and easy conversion to a sternotomy if either should be necessary.
Finally, the results of our follow-up questionnaire demonstrate that patients can make well-informed decisions about this new technology if appropriate pre-operative education is given. Those patients without anastomotic complications all had an extremely high satisfaction level with the procedure and would recommend the procedure to others.
In conclusion, this study demonstrates that RACAB provides good mid-term results, with a steep early surgeon learning curve. Rapid recovery time and excellent patient satisfaction are benefits of the procedure. Careful study of this operative technique along with examination of the lessons learned by others in this field may help improve overall results and expand training strategies.
References
Dogan S, Aybek T, Andressen E, Byhahn C, Mierdl S, Westphal K, Matheis G, Moritz A, Wimmer-Greinecker G. Totally endoscopic coronary artery bypass grafting on cardiopulmonary bypass with robotically enhanced telemanipulation: report of forty-five cases. J Thorac Cardiovasc Surg 2002;123:1125–1131.
Mohr FW, Falk V, Diegeler A, Walther T, Gummert JF, Bucerius J, Jacobs S, Autschbach R. Computer-enhanced robotic cardiac surgery: experience in 148 patients. J Thorac Cardiovasc Surg 2001;121:842–853.
Falk V, Diegeler A, Walther T, Loscher N, Vogel B, Ulmann C, Rauch T, Mohr FW. Endoscopic coronary artery bypass grafting on the beating heart using a computer enhanced telemanipulation system. Heart Surg Forum 1999;2:199–205.
Falk V, Fann JI, Grunenfelder J, Daunt D, Burdon TA. Endoscopic computer-enhanced beating heart coronary artery bypass grafting. Ann Thorac Surg 2000;70:2029–2033.
Subramanian VA, Patel NU. Current status of MIDCAB procedure. Current Opinion in Cardiology 2001;16:268–270.
Trehan N, Malhotra R, Mishra Y, Shrivastva S, Kohli V, Mehta Y. Comparison of ministernotomy with minithoracotomy regarding postoperative pain and internal mammary artery characteristics. Heart Surgery Forum 2000;3:300–306.
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;69:1338–1340.
Vassiliades TA. Atraumatic coronary artery bypass: technique and outcomes. Heart Surg Forum 2001;4:331–334.
Loulmet D, Carpentier A, d'Attellis N, Berrebi A, Cardon C, Ponzio O, Aupecle B, Relland JY. Endoscopic coronary artery bypass grafting with the aid of robotic assisted instruments. J Thorac Cardiovasc Surg 1999;118:4–10.
Falk V, Diegeler A, Walther T, Loscher N, Vogel B, Ulmann C, Rauch T, Mohr FW. Endoscopic coronary artery bypass grafting on the beating heart using a computer enhanced telemanipulation system. Heart Surg Forum 1999;2:199–205.
Tabaie HA, Graper WP, Reinbolt JA. Clinical investigation: endoscopic coronary artery bypass grafting with robotic assistance. Heart Surg Forum 2002;5:328–333.
Novick RJ, Fox SA, Kiaii BB, Stitt LW, Rayman R, Kodera K, Menkis AH, Boyd WD. Analysis of the learning curve in telerobotic beating heart coronary artery bypass grafting: a 90 patient experience. Ann Thorac Surg 2003;76:749–753.(Joseph J. DeRose, Jr, San)
b Department of Surgery, St. Luke's-Roosevelt Hospital Center, New York, NY 10025, USA
c Division of Cardiology, Department of Medicine, St. Luke's-Roosevelt Hospital Center, New York, NY 10025, USA
Presented at the 7th Annual Scientific Meeting of the International Society of Minimally Invasive Cardiothoracic Surgery, London, England, June 2004.
Abstract
We sought to study our mid-term outcomes and our patient's perceptions of robotically-assisted coronary artery bypass (RACAB). The daVinciTM robotic system was utilized to harvest and prepare the internal thoracic artery (ITA) as well as to open the pericardium and identify the target vessels. Anastomoses were performed by hand on the beating heart through limited incisions using an endoscopic stabilizing device. A follow-up telephone interview was conducted with patients at 3 to 6 months. Between 4/12/02 and 11/1/04, 37 patients underwent RACAB (1.2 distal anastomoses/patient). Median length of stay was 3 days (2–14 days) and 82% of patients reported full return to baseline activity within 10 days of surgery. There were two early LITA complications and one late anastomotic stenosis all of which occurred within the first two cases of each surgeon's experience. The majority of patients surveyed (95%) knew that robotics were involved in their surgery and most patients (95%) would recommend RACAB (95%). RACAB is an effective minimally invasive revascularization technique with excellent recovery times and high patient satisfaction. The early complication rate emphasizes the steep learning curve for this procedure as well as the need for intensive pre-procedure training.
Key Words: Robotic surgery; Coronary artery bypass grafting; Off-pump surgery
1. Introduction
Minimally invasive approaches to coronary artery revascularization range from off-pump coronary artery bypass grafting (OPCAB) through a sternotomy, to totally endoscopic coronary artery bypass grafting (TECAB) using robotic facilitation [1–4]. Whereas OPCAB has become an easily reproducible procedure with fairly widespread surgeon adoption, TECAB on both the beating and arrest heart has been plagued by high technical demands with a steep and long learning curve.
Traditional mid-CAB has met with an adoption level between both OpCAB and TECAB [5]. However, significant post-operative pain secondary to chest wall retraction during left internal thoracic artery (LITA) mobilization, as well as wound complications, have left many surgeons unhappy with the minimally invasive nature of this procedure [6,7]. Endoscopic LITA mobilization with a non-rib spreading thoracotomy and open coronary anastomosis (endo-ACAB) has been performed with excellent results [8]. This procedure has failed to gain widespread acceptance because of the technical demands of endoscopic LITA mobilization. The facilitating technology of robotics promises to decrease the learning curve associated with endoscopic LITA harvest. Simultaneously, the advantages of non-rib spreading, open, beating heart surgery might be retained with robotically-assisted CABG (RACAB).
We sought to evaluate our mid-term results with RACAB in order to validate its efficacy and carefully study the procedure's learning curve. We also hoped to understand patient's perceptions of RACAB as well as their satisfaction level.
2. Materials and methods
An IRB-approved database was established for the prospective evaluation of all patients undergoing RACAB. Exclusion criteria included emergency status, moderate to severe valvular disease, decompensated congestive heart failure, endocarditis, and acute renal failure. All patients undergoing RACAB at our institution over the study period were enrolled and this report represents the first 37 patients undergoing the procedure.
The daVinciTM robotic system was utilized in all cases. The pericardium was opened and target vessels were identified. This allowed for assessment of conduit length, target vessel anastomotic site and the presence of target vessel intra-myocardial course. The LITA was then dissected in a semi-skeletonized fashion by mobilizing the artery and vein together without associated muscle or fascia.
The camera port site was extended and the 4th or 5th intercostal space was opened. A soft tissue retractor was placed (Fig. 1). An endoscopic stabilizer (Medtronic, Minneapolis, MN) was introduced through the left arm port and the heart was positioned (Fig. 2). The anastomoses were then performed by hand on the beating heart.
All patients underwent nuclear stress testing at 3 months. Follow-up angiography was performed only if the patient reported symptoms or if there were new reversible defects on routine stress testing. A short questionnaire was conducted via phone 3–6 months following discharge.
All data are presented as the mean±standard deviation. Discrete variables were compared using the chi-square test and continuous variables were compared using the Mann-Whitney test.
3. Results
Between 4/12/02 and 11/1/04, 37 patients underwent RACAB. Thirty-five operations were performed by one surgeon (J.D.) and two operations were performed by another surgeon (D.S.). The pre-operative patient characteristics are listed in Table 1. Indications for surgery are listed in Table 2. The most common indication for RACAB was as part of a hybrid revascularization (51%). Among patients undergoing hybrid revascularization, 11 patients received a percutaneous intervention to a single vessel and 8 patients had a percutaneous intervention to more than one vessel. All patients undergoing hybrid revascularization underwent the percutaneous intervention first. RACAB was then performed between 1 to 30 days later. Clopidogrel was used in every hybrid revascularization up until the date of surgery. Twenty-seven (73%) patients underwent small anterior thoracotomy and 9 (24%) underwent lower hemi-sternotomy into the left 3rd interspace.
One obese diabetic patient with a very small circumflex system and a tight ostial LAD with a long left main vessel was chosen for single vessel RACAB through a non-rib spreading anterior thoracotomy. The patient undergoing partial revascularization was a 61-year-old woman with insulin dependent diabetes mellitus, a prior left below knee amputation, who did not ambulate and was admitted with a gangrenous right foot and required peripheral vascular surgery. Because of the patient's frail pre-operative status, limited ambulation and lack of appropriate conduit, it was elected that a single vessel RACB would be performed.
Successful LITA takedown was performed in all patients except one. This patient was the second patient in our RACAB experience and he had an LITA dissection. The patient underwent uneventful conversion to sternotomy. His pedicled RITA was mobilized in the conventional manner and was used to bypass the left anterior descending artery (LAD). A total of 43 distal anastomoses were performed (1.2/case). Six patients underwent more than one distal anastomosis and these specific configurations are displayed in Table 3. The patient undergoing pedicled RIMA anastomosis to his LAD, and LIMA anastomosis to his diagonal, had isolated LAD/diagonal disease. His diagonal vessel was a large lateral vessel and the anatomic arrangement was not amenable to sequential grafting with the LIMA. The patient undergoing LIMA-LAD grafting and saphenous vein grafting to the right coronary artery (RCA) had ostial RCA and ostial LAD lesions. The LIMA was mobilized robotically and the coronary grafting was then performed off-pump through a lower hemisternotomy.
Post-operative complications included one wound infection and one reoperation for bleeding. The wound infection occurred in a morbidly obese diabetic woman with very large breasts who underwent a limited anterior thoracotomy. The bleeding episode that required re-operation resulted from an intercostal branch in the robotic left arm port. Three patients (8%) had a limited episode of atrial fibrillation. Only three patients (8%) with low pre-operative hematocrits (25%, 28% and 27%) required blood transfusions after surgery. One patient who underwent a pre-operative right coronary artery stent had acute stent occlusion on the first post-operative night that required emergency repeat percutaneous intervention.
Median length of stay was 3 days (2–17 days) and 82% of patients reported full return to baseline activity within 10 days of surgery. All patients were discharged to their home with the exception of one 84-year-old woman who went to inpatient rehabilitation. At a mean follow-up of 16.1±8.4 months (3–31 months), all patients are alive and well and chest pain free. During this follow-up period, 10 patients underwent repeat coronary angiography (post-operative day 0 to 13 months post-op). There was one anastomotic stenosis detected at 13 months. A second patient returned with an LITA stenosis which required percutaneous intervention and subsequent re-operation. The seven other patients undergoing angiography had widely patent anastomoses. Of the three LITA-LAD complications (1 LITA injury, 1 mid- LITA stenosis and 1 anastomotic stenosis), all occurred within the first two cases of each surgeon's experience.
There have been no deaths over the follow-up period and no patient has had a myocardial infarction. Of the 15 patients undergoing hybrid revascularization, three required repeat percutaneous intervention. Two patients had instent restenosis and a third patient presented with a new ramus lesion which required a stent.
Of the 37 patients undergoing RACAB, 20 patients completed the 19-question phone survey (Table 4). The majority of patients correctly identified their diagnosis (80%), the procedure they were undergoing (80%) and the organ that was being operated upon (95%). All patients were satisfied (100%) and understood the information (100%) provided by their surgeons. Most patients knew that the robot was involved in their operation (95%). When asked who actually performed the operation, the responses were ‘surgeon’ (68%), ‘both’ (11%), ‘robot’ (5%), and ‘don't know’ (16%). Most patients felt they benefited from robotic surgery as opposed to the traditional open method (84%). Shorter recovery time, smaller scar, and less invasive were the most common benefits mentioned. No statistically significant difference was seen based on educational experience or annual income.
4. Discussion
The first reports describing the use of robotics in myocardial revascularization appeared in the literature in 1999 [9,10]. In an attempt to make the leap to ‘outpatient’ and ‘no incision’ CABG, cardiac robotic surgeons have investigated the development of TECAB. As part of the learning curve, those in both Europe and the United States started with the ‘intermediary’ step of arrested heart TECAB [1,4]. Although some had early success, complications with endoaortic balloon occlusion and cardiopulmonary bypass as well as early LITA injuries left many unfulfilled with this procedure. Furthermore, not only was training in robotic skills necessary, but extensive experience with minimally invasive CPB techniques was also a pre-requisite for the success of this procedure. In order to remove this layer of complexity, some surgeons have begun programs to perform beating heart TECAB [10,11]. Although some groups have reported impressive initial success, the technical demands of this procedure thus far have proved to be a significant barrier to its wide adoption.
The robot is a tool to aid the minimally invasive cardiac surgeon in a variety of techniques. When viewed in this manner, RACAB becomes the logical extension of the more time-tested procedures of mid-CAB and endoscopic-assisted coronary artery bypass (endo-ACAB). The three-dimensional vision and computer interface of robotics makes both vessel identification and IMA mobilization quicker and easier than if performed with either a mid-CAB retractor or a thoracoscope. The endoscopic stabilizer used in these operations greatly enhances operating space through either rib-spreading or non-rib spreading thoracotomies. Although originally designed for TECAB, its application in RACAB has served to minimize the size of the anterior thoracotomy incision. The stabilization provided is via both suction and compression and works well for anterior vessels. An endoscopic suction cup needs to be added in order to be able to graft lateral wall vessels through this incision.
Despite its relative ease of adoption, RACAB is not without a learning curve. Learning to use visual clues for tactile feedback and becoming comfortable with the anterior thoracotomy approach seem to be important steps in mastering this operation. Novick has previously demonstrated the learning curve that exits for robotic LITA mobilization by measuring operative times and complications [11]. Although intuitive for any type of learning process, our study corroborates these findings with respect to our early complications. When the early learning curve is eliminated (i.e. the first two cases of each surgeon's experience), no anastomotic complications or LITA injuries were encountered in this series. These results are similar to prior large series of endo-ACAB [8] and mid-CAB [5].
The ability to avoid morbidities may lie in specific skill-based learning. As no robotic skill development training currently exists, there is also no specific credentialing process required to begin a robotic cardiac surgery program. We and others continue to work to develop such standardized training programs for robotic skills [12]. In the interim, an internal plan for surgeon training is necessary to master the RACAB procedure. Extensive experience with sternal sparing off-pump surgery does make this transition simpler. However, specific robotic skills should be mastered on both inanimate and animate models prior to performing procedures in human subjects. Although sometimes time-consuming and difficult, we would recommend robotic LITA takedown, LITA preparation, and coronary vessel identification with planned conversion to sternotomy in a number of cases prior to performing a sternal-sparing RACAB. The lower hemi-sternotomy was used by our group for our first six cases as an intermediary step in the progression towards limited anterior thoracotomy. This approach allows for open takedown of the distal LITA and easy conversion to a sternotomy if either should be necessary.
Finally, the results of our follow-up questionnaire demonstrate that patients can make well-informed decisions about this new technology if appropriate pre-operative education is given. Those patients without anastomotic complications all had an extremely high satisfaction level with the procedure and would recommend the procedure to others.
In conclusion, this study demonstrates that RACAB provides good mid-term results, with a steep early surgeon learning curve. Rapid recovery time and excellent patient satisfaction are benefits of the procedure. Careful study of this operative technique along with examination of the lessons learned by others in this field may help improve overall results and expand training strategies.
References
Dogan S, Aybek T, Andressen E, Byhahn C, Mierdl S, Westphal K, Matheis G, Moritz A, Wimmer-Greinecker G. Totally endoscopic coronary artery bypass grafting on cardiopulmonary bypass with robotically enhanced telemanipulation: report of forty-five cases. J Thorac Cardiovasc Surg 2002;123:1125–1131.
Mohr FW, Falk V, Diegeler A, Walther T, Gummert JF, Bucerius J, Jacobs S, Autschbach R. Computer-enhanced robotic cardiac surgery: experience in 148 patients. J Thorac Cardiovasc Surg 2001;121:842–853.
Falk V, Diegeler A, Walther T, Loscher N, Vogel B, Ulmann C, Rauch T, Mohr FW. Endoscopic coronary artery bypass grafting on the beating heart using a computer enhanced telemanipulation system. Heart Surg Forum 1999;2:199–205.
Falk V, Fann JI, Grunenfelder J, Daunt D, Burdon TA. Endoscopic computer-enhanced beating heart coronary artery bypass grafting. Ann Thorac Surg 2000;70:2029–2033.
Subramanian VA, Patel NU. Current status of MIDCAB procedure. Current Opinion in Cardiology 2001;16:268–270.
Trehan N, Malhotra R, Mishra Y, Shrivastva S, Kohli V, Mehta Y. Comparison of ministernotomy with minithoracotomy regarding postoperative pain and internal mammary artery characteristics. Heart Surgery Forum 2000;3:300–306.
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;69:1338–1340.
Vassiliades TA. Atraumatic coronary artery bypass: technique and outcomes. Heart Surg Forum 2001;4:331–334.
Loulmet D, Carpentier A, d'Attellis N, Berrebi A, Cardon C, Ponzio O, Aupecle B, Relland JY. Endoscopic coronary artery bypass grafting with the aid of robotic assisted instruments. J Thorac Cardiovasc Surg 1999;118:4–10.
Falk V, Diegeler A, Walther T, Loscher N, Vogel B, Ulmann C, Rauch T, Mohr FW. Endoscopic coronary artery bypass grafting on the beating heart using a computer enhanced telemanipulation system. Heart Surg Forum 1999;2:199–205.
Tabaie HA, Graper WP, Reinbolt JA. Clinical investigation: endoscopic coronary artery bypass grafting with robotic assistance. Heart Surg Forum 2002;5:328–333.
Novick RJ, Fox SA, Kiaii BB, Stitt LW, Rayman R, Kodera K, Menkis AH, Boyd WD. Analysis of the learning curve in telerobotic beating heart coronary artery bypass grafting: a 90 patient experience. Ann Thorac Surg 2003;76:749–753.(Joseph J. DeRose, Jr, San)