EJCTS Click here to go to Edwards website
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Author home page(s):
Hani Shennib
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Shennib, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shennib, H.

Eur J Cardiothorac Surg 1999;16:S93-S96
© 1999 Elsevier Science NL

Tools for precision enhancement in minimally invasive cardiac surgery: three dimensional visualization, computer enhancement and robotics

Hani Shennib*

Division of Cardiothoracic Surgery, McGill University, The Montreal General Hospital, 1650 Cedar Avenue, Room L9-121, Montreal, Quebec H3G 1A4, Canada

* Tel.: +1-514-934-8099; fax: +1-514-934-8235


   Abstract
Top
 Abstract
1. Introduction
 References
 
This article is a current update of the rationale for development of new enabling technologies in minimally invasive cardiac surgery. Specifically the potential advantages of three dimensional visualization, computer enhancement technology and robotics in performance of totally endoscopic coronary artery bypass grafts will be addressed.

Key Words: Endoscopic surgery • Minimally invasive cardiac surgery • Endoscopic coronary bypass grafting • Robotic surgery


   1. Introduction
Top
 Abstract
 1. Introduction
References
 
1.1 The emergence of catheter based therapy
It is intriguing to recognize that initial attempts for coronary artery revascularization in the early 1960s were mostly through ‘off pump' techniques [1–4]. The rapid expansion of utilization of cardiopulmonary bypass for the treatment of valvular and congenital heart disease and the facility of performing coronary artery bypass grafts on the arrested and fibrillated heart rendered off pump techniques obsolete (Fig. 1). In the mid 1980s however, interventional cardiologists proposed catheter based techniques as a modality of treatment for this single coronary artery disease [5]. This applicability however, extended rapidly to multi-vessels and, unfavorable coronary artery lesions and diseased vein grafts [6–14]. This widely adapted yet unproven approach stimulated the expansion of catheter device modalities with major medical industry driving or being driven by the expansion of interventional cardiology practice. The clear advantage of catheter based coronary revascularization is, that it is more patient friendly and has less early morbidity then conventional coronary artery bypass surgery. Despite the concern with less than complete revascularization, an increased incidence of recurrent symptoms, requirement for reintervention and a repeated documentation of limitation in long-term outcome, catheter based interventions are increasingly the choice of treatment for most coronary artery patients. Today it is estimated that approximately 2/3 of all coronary revascularization is done by angioplasty and stenting.


Figure 1
View larger version (17K):
[in this window]
[in a new window]
  		Fig. 1. Changing trends in coronary revascularization.

 
1.2 Prospective on surgical revascularization
The growth in utility of catheter based therapy for coronary artery revascularization has the implication that conventional surgical revascularization will decrease in numbers. Other factors which will enhance the decline in conventional coronary artery bypass grafting (CABG) is the recognition that routine utility of cardiopulmonary bypass in the course of performing conventional CABG has the added risk of neuro-psychological and other organ dysfunction [15–19]. These observations are becoming more obvious as our methods of detecting injury are more sensitive. Patient and referring cardiologists are increasingly in favor of catheter based revascularization over conventional CABG.

Approximately 8 years ago, and stimulated by the success of endoscopic general and thoracic surgery we embarked on an experimental program to explore the potential role for endoscopic techniques in cardiac surgery. Our initial attempts where directed towards peripheral arterial and venous cannulation and totally endoscopic CABG and valve surgery through small thoracoscopic ports [20]. We very soon recognized that elimination of utility of CPB for coronary artery bypass graft surgery was a desired feature to render CABG less invasive. This was further substantiated by a consensus build in the cardiac surgery community that the removal of cardiopulmonary by pass as a component of CABG was more beneficial to patients than avoiding the sternotomy incision [21].

It was hence natural that most technological advances in minimally invasive CABG over the last 3 years were focused on surgery for the beating heart. The most important technological advance in the less invasive CABG was in stabilization of the coronary arteries. Several generations of mechanical and suction stabilizers have been developed and validated experimentally and clinically. Currently the reported results of ‘off pump' CABG are comparable to that of conventional CABG [22]. Despite of this, there remains great uncertainty among the majority of cardiac surgeons as to the adequacy of ‘off pump' coronary artery anastamosis and, no prospective trials have been attempted to compare the results of ‘off pump' with conventional CABG. In addition methods to confirm the adequacy of ‘off pump' anastamosis are less than adequate. Except for coronary angiography, other devices such as intraoperative Doppler scans which measure graft flow have not been convincing in ascertaining a quality type A Fitzgerald anastamosis. It is possible that good graft flow and diastolic augmentation can be recorded despite errors in anastamotic technique and the presence of an inappropriately anchoring suture at the heel, the toe, or a waist. It is hence instrumental that technological advances be sought to enable surgeons to comfortably perform the perfect ‘off pump' CABG.

Furthermore most multivessel CABG are currently done through a full sternotomy, an incision that is extensive, painful and cosmetically undesired also. It is no wonder that patients seek multi-vessel transcatheter revascularization despite its short term efficacy. It is incombinent upon us surgeons in order to render CABG truly minimally invasive, to explore the potential for performing it totally endoscopically.

1.3 Requirements for endoscopic CABG
The three essential enabling technologies for totally endoscopic CABG are adequate visualization, instrumentations, and dexterity enabling technology.

In order to dissect the importance of visualization from instrumentation as key components for performance of endoscopic CABG we performed laboratory studies in which on bench arterial graft to LAD anastamosis were done using either conventional or endoscopic instrumentation. In each of the groups we used either surgical loups, two dimensional monitor display, two dimensional head display, and three dimensional head mounted display. What was striking was the marked prolongation of anastamotic time with the utilization of endoscopic instruments regardless of the visualization method used. This clearly reflects that endoscopic instruments alone without added enabling technology are crude. However, despite the limitations of endoscopic instruments, three dimensional head mounted display improved timing of the anastamosis and led to comparable times to that of direct visualization with surgical loups and was superior to two dimensional monitors or head mounted displays (Figs. 2 and 3) .


Figure 2
View larger version (17K):
[in this window]
[in a new window]
  		Fig. 2. Comparison between coronary artery anastamosis done by conventional or endoscopic instruments with two- and three-dimensional tools.

 

Figure 3
View larger version (17K):
[in this window]
[in a new window]
  		Fig. 3. Comparison between coronary artery anastamosis done by conventional or endoscopic instruments with two- and three-dimensional tools.

 
When we compared on bench CABG performed using conventional instruments with endoscopic instruments there was a significant increase in anastamotic time more difficulty and a poorer quality of anastamosis with endoscopic instruments. This disadvantage however was reversed when computer enhanced robotic technology was incorporated into the surgical instruments with a significant improvement in timing, quality of anastamosis and degree of difficulty [23,24]. These two studies confirmed the importance of three dimensional visualization computer enhanced enabling technology and robotics for facilitation of totally endoscopic CABG.

1.4 Current clinical status of endoscopic CABG
Since the early experiments performed in December of 1997, computer enhancement and robotic technology have made major strides. There are currently over 75 clinical cardiovascular cases reported to have been performed using either the ‘intuitive' or ‘computer motion' technology world wide. Totally endoscopic mammary artery to LAD anastamosis have been performed on approximately a dozen patients and many minithoracotomy computer enhanced mitral valve repair, replacement and ASD repair were done. Clinical observations made during these procedures confirm the potential for utility of this technology and opens the field for more advances required before this technology is incorporated routinely in operating rooms. Most robotic arms remain crude, long and take much operating room space. Robotics in joints and strings do loosen up and require interrupted adjustments. Operating rooms are transformed into ‘war zones' occupied by monstrous machines. These ‘Hassle' factors need to be illuminated. The cost of acquiring such robots are staggering and does not go well with the general mode of cost containment. It is hence, currently available only to a limited number of cardiac centers. Nevertheless computer enhanced enabling technology is the wave of the future and if the technology is simplified, and rendered less expensive it will only be a matter of time before the surgical community recognizes its general applicability.

In conclusion, minimally invasive coronary artery bypass graft surgery is gaining increasing acceptance among cardiac surgeons and in time will replace conventional methods. Minimally invasive techniques will no question rise to become the definitive modality for long term effective revascularization of coronary artery disease. Totally endoscopic CABG is the ultimate form of minimally invasive surgery. Enabling visualization, computer enhancement and robotic technology will have a major impact in developing endoscopic CABG.


   Footnotes
 
{star} Presented at the International Symposium ‘Present State of Minimally Invasive Cardiac Surgery – Meet The Experts', Dresden, Germany, December 3–5, 1998.


   References
Top
 Abstract
 1. Introduction
 References
 

  1. Goetz RH, Rohman M, Haller JD, Dee R, Rosenak SS. Internal mammary coronary artery anastamosis – a non-suture method employing tantalum rings. J Thorac Cardiovasc Surg 1961;41:378-386.[Medline]
  2. Sabiston Jr DC. The coronary circulation. Johns Hopkins Med J 1974;134:314-329.[Medline]
  3. Kolessov VI. Mammary artery – coronary artery anastamosis as method of treatment for angina pectoris. J Thorac Cardiovasc Surg 1967;54:535-544.[Medline]
  4. Ankeney J. To use or not to use the pump oxygenator in coronary bypass operations. Ann Thorac Surg 1975;19:108-109.[Medline]
  5. Sigwart U, Puel J, Mirkovitch V, Joffre F, Kappenberger L. Intravascular stents to prevent occlusion and restenosis after transluminal angioplasty. New Engl J Med 1996;78:757-762.
  6. Topol E, Leya F, Pinkerton C, Whitlow PL, Hofling B, Simonton CA, Masden RR, Serruys PW, Leon MB, Williams DO, King III SB, Mark DB, Isner JM, Holmes Jr DR, Ellis SG, Lee KL, Keeler GP, Berdan LG, Hinohara T, Califf RM. A comparison of directional atherectomy with coronary angioplasty in patients with coronary artery disease. New Engl J Med 1993;329:221-227.[Abstract/Free Full Text]
  7. Guerin Y, Spaulding C, Desno M, Funck F, Rahal S, Py A, Besse B, Tsocanakis O, Guerin F, Guerot C. Rotational atherectomy with adjunctive balloon angioplasty versus conventional percutaneous transluminal angioplasty in type B2 lesions: results of a randomized study. Am Heart J 1996;131:879-883.[Medline]
  8. Fischman DL, Leon MB, Baim DS, Schatz RA, Savage MP, Penn I, Detre K, Veltri L, Ricci D, Nobuyoshi M, Cleman M, Heuser R, Almond D, Teirstein PS, Fish RD, Colombo A, Brinker J, Moses J, Shaknovich A, Hirshfeld J, Stephen SB, Rake ER, Goldberg S. A randomized comparison of coronary stent placement and balloon angioplasty in patients with coronary artery disease. New Engl J Med 1994;331:496-501.[Abstract/Free Full Text]
  9. Serruys PW, De Jaegere P, Kiemenij F, Macaya C, Rutsch W, Heyndrickx G, Emanuelsson H, Marco J, Legrand V, Materne P, Belardi J, Sigwart U, Colombo A, Goy JJ, van den Heuvel P, Delcan J, Morel MA. A comparison of balloon expandable stent implantation with balloon angioplasty in patients with coronary artery disease. New Engl J Med 1994;331:489-495.[Abstract/Free Full Text]
  10. Waksman R. Local catheter-based intracoronary radiation therapy for restenosis. Am J Cardiol 1996;78:23-28.[Medline]
  11. Tierstein PS, Massulo V, Jani S. Catheter-based radiotherapy to inhibit restenosis after coronary stenting. New Engl J Med 1997;336:1697-1703.[Abstract/Free Full Text]
  12. Ruocco NA, Ring ME, Holubkov R, Jacobs AK, Detre KM, Faxon DP. Results of coronary angioplasty of chronic total occlusion (The National Heart Lung and blood Institute. 1985-1986 Percutaneous Transluminal Angioplasty Registry). Am J Cardio 1992;69:69-76.
  13. Ivanhoe RJ, Weintraub WS, Douglas Jr JS, Lembo NJ, Furman M, Gershony G, Cohen CL, King 3d SB. Percutaneous transluminal coronary angioplasty of chronic total occlusions primary success, restenosis and long-term clinical follow-up. Circulation 1992;85:106-115.[Abstract/Free Full Text]
  14. Hamburger JN, Serruys PW, Scabra-Gomes R, Simon R, Koolen JJ, Fleck E, Mathey D, Sievert H, Rutsch W, Buchwald A, Marco J, Al-Kasab SM, Pizulli L, Hamm C, Corcos T, Reifart N, Hanrath P, Taeymans Y. Recanalization of total coronary occlusions using a laser guidewire (The European TOTAL Surveillance Study). Am J Cardiol 1997;80:1419-1423.[Medline]
  15. Anderson DR, Edmunds LH, Stephenson LW. Management if complications of cardiopulmonary bypass: complications of organ systems. In: Waldhausen JA, Orringer MB, editors. Complications in cardiothoracic surgery. St. Louis: Mosby Year Book; 1991. pp. 45-59.
  16. Pae WE, Troncelliti EK, Waldhausen JA, Williams DR. Prevention of complications during cardiopulmonary bypass. In: Waldhausen JA, Orringer MB, editors. complications in cardiothoracic surgery. St. Louis: Mosby Year Book; 1991. pp. 39-45.
  17. Bhasker-Rao B, Vanhimbergen D, Ali A, Edmonds HL, Spence PA. Evidence for improved cerebral function after minimally invasive bypass surgery. Presentation at the Third International Utrecht MICABG Workshop and Course, Utrecht, Netherlands 1997:26-27.
  18. Cremer J, Stuber M, Wittwer T, et al. Morbidity of cardiopulmonary bypass and potential benefits of minimally invasive coronary surgery off pump. Cor Europeaum 1997;6:164-167.
  19. Abel RM, Buckley NJ, Austen WG, Barnett GO, Beck Jr CH, Fischer JE. Etiology, incidence and prognosis of renal failure following cardiac operations. J Thorac Cardiovasc Surg 1992;104:469-474.[Abstract]
  20. Shennib H. Evolving strategies in minimally invasive coronary artery surgery. Int J Cardiol 1997;62(Suppl 1):S81-S88.
  21. Shennib H, Mack MJ, Lee A. A survey on minimally invasive coronary artery bypass grafting. Ann Thorac Surg 1997;64:110-115.[Abstract/Free Full Text]
  22. Mack MJ, Osbourne JA, Shennib H. Arterial graft patency in coronary artery bypass grafting: what do we really know?. Ann Thorac Surg 1998;66:1055-1059.[Abstract/Free Full Text]
  23. Shennib H, Bastawisy A, Mack M, Moll F. Computer-assisted telemanipulation: an enabling technology for endoscopic coronary artery bypass. Ann Thorac Surg 1998;66:1060-1063.[Abstract/Free Full Text]
  24. Shennib H, Bastawisy A, Moll F. Robotic computer-assisted telemanipulation enhances coronary artery bypass. J Thorac Cardiovasc Surg 1999;117:310-313.[Abstract/Free Full Text]




This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Author home page(s):
Hani Shennib
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Shennib, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shennib, H.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ANN THORAC SURG ASIAN CARDIOVASC THORAC ANN EUR J CARDIOTHORAC SURG
J THORAC CARDIOVASC SURG ICVTS ALL CTSNet JOURNALS