Early angiographic results after revascularization by minimally invasive direct coronary artery bypass (MIDCAB)

Mid-Term Results of Minimally Invasive Direct Coronary Artery Bypass Grafting

Background

Minimally invasive direct coronary artery bypass grafting (MIDCAB) has the advantage of allowing arterial grafting on the left anterior descending artery without a sternotomy incision. We present our single-center clinical experience of 66 consecutive patients.

Methods

All patients underwent MIDCAB through a left anterior small thoracotomy between August 2007 and July 2015. Preoperative, intraoperative, postoperative and follow-up data—including major adverse cardiovascular and cerebrovascular events (MACCE), graft patency, and the need for re-intervention—were collected.

Results

The mean age of the patients was 69.4±11.1 years and 73% were male. There was no conversion to an on-pump procedure or a sternotomy incision. The 30-day mortality rate was 1.5%. There were no cases of stroke, although 2 patients had to be re-explored for bleeding, and 81.8% were extubated in the operating room or on the day of surgery. The median stay in the intensive care unit and in the hospital were 1.5 and 9.6 days, respectively. The median follow-up period was 11 months, with a 5-year overall survival rate of 85.3%±0.09% and a 5-year MACCE-free survival rate of 72.8%±0.1%. Of the 66 patients, 32 patients with 36 grafts underwent a postoperative graft patency study with computed tomography angiography or coronary angiography, and 88.9% of the grafts were patent at 9.7±10.8 months postoperatively.

Conclusion

MIDCAB is a safe procedure with low postoperative morbidity and mortality and favorable mid-term MACCE-free survival.

Off-Pump Coronary Artery Bypass Surgery

Off-pump coronary artery bypass surgery has been adopted enthusiastically worldwide. However, despite more than 6 years’ experience and refinement, many surgeons use it only sporadically and some hardly at all. This reluctance persists despite support for the procedure because of the lack of properly designed risk models and/or randomized studies. Although it has not been overwhelmingly shown that off-pump surgery is superior to the conventional on-pump procedure, the technique has its place in our specialty. It has been shown to be better for noncritical end points in selected patients in the hands of selected surgeons. That there are differences in surgical skill among surgeons is something we all know but rarely discuss in public. Until now, disparities in skill have been most salient with uncommon and extraordinarily challenging operations. Perhaps the off-pump procedure should be regarded as the “challenging” aspect of coronary artery bypass surgery, and self-restraint may need to remain in force if we are to continue to achieve the highest level of clinical excellence.

Autologous microsurgical breast reconstruction and coronary artery bypass grafting: an anatomical study and clinical implications

OBJECTIVE

To identify possible avenues of sparing the internal mammary artery (IMA) for coronary artery bypass grafting (CABG) in women undergoing autologous breast reconstruction with deep inferior epigastric artery perforator (DIEP) flaps.

BACKGROUND

Optimal autologous reconstruction of the breast and coronary artery bypass grafting (CABG) are often mutually exclusive as they both require utilisation of the IMA as the preferred arterial conduit. Given the prevalence of both breast cancer and coronary artery disease, this is an important issue for women's health as women with DIEP flap reconstructions and women at increased risk of developing coronary artery disease are potentially restricted from receiving this reconstructive option should the other condition arise.

METHODS

The largest clinical and cadaveric anatomical study (n=315) to date was performed, investigating four solutions to this predicament by correlating the precise requirements of breast reconstruction and CABG against the anatomical features of the in situ IMAs. This information was supplemented by a thorough literature review.

RESULTS

Minimum lengths of the left and right IMA needed for grafting to the left-anterior descending artery are 160.08 and 177.80 mm, respectively. Based on anatomical findings, the suitable options for anastomosis to each intercostals space are offered. In addition, 87-91% of patients have IMA perforator vessels to which DIEP flaps can be anastomosed in the first- and second-intercostal spaces.

CONCLUSION

We outline five methods of preserving the IMA for future CABG: (1) lowering the level of DIEP flaps to the fourth- and fifth-intercostals spaces, (2) using the DIEP pedicle as an intermediary for CABG, (3) using IMA perforators to spare the IMA proper, (4) using and end-to-side anastomosis between the DIEP pedicle and IMA and (5) anastomosis of DIEP flaps using retrograde flow from the distal IMA. With careful patient selection, we hypothesize using the IMA for autologous breast reconstruction need not be an absolute contraindication for future CABG.

Advances in medical robotic systems with specific applications in surgery--a review

Although robotics was started as a form of entertainment, it gradually became used in different branches of science. Medicine, particularly in the operating room, has been influenced significantly by this field. Robotic technologies have offered valuable enhancements to medical or surgical processes through improved precision, stability and dexterity. In this paper we review different robotics and computer-assisted systems developed with medical and surgical applications. We cover early and recently developed systems in different branches of surgery. In addition to the united operational systems, we provide a review of miniature robotic, diagnostic and sensory systems developed to assist or collaborate with a main operator system. At the end of the paper, a discussion is given with the aim of summarizing the proposed points and predicting the future of robotics in medicine.

Coronary artery bypass grafting without full sternotomy

Coronary artery bypass grafting is performed without full sternotomy in selected patients because it is less invasive. Left internal thoracic artery-left anterior descending artery bypass (LITA-LAD bypass) via a small left anterior thoracotomy is a well established procedure, which achieves good graft patency with low mortality and morbidity rates. Multiple revascularization is possible with a limited lateral thoracotomy or L-figure approach. Axillary-coronary bypass and right gastroepiploic artery-right coronary artery bypass (RGEA-RCA bypass) are alternative methods, especially for redo surgery, in selected patients.

Midterm Follow-Up After Minimally Invasive Direct Coronary Artery Bypass Grafting Versus Percutaneous Coronary Intervention Techniques

BACKGROUND

Revascularization of the left anterior descending coronary artery can be performed by minimally invasive direct coronary artery bypass grafting (MIDCAB) or percutaneous coronary intervention techniques (PCI). The study compared the midterm results of both techniques.

METHODS

The outcome of 206 consecutive MIDCAB and 256 PCI patients treated from 1998 until 2001 was retrospectively analyzed. Cardiologists determined the primary patient allocation for the distinct revascularization technique. Periprocedural complications and midterm follow-up, including quality-of-life assessment (SF-36), was reported up to 5.2 years (3.4 +/- 0.7 years).

RESULTS

Periprocedural and overall mortality (p = 0.206) showed no differences. Four MIDCAB patients required early reoperation but not for repeated target vessel revascularization. In 16 patients secondary PCI (7.8%) of other coronary vessels was performed. Repeated revascularization of the left anterior descending coronary artery was necessary in 24.2% of patients in the PCI group (p < 0.001), with 4.7% finally requiring surgical revascularization. The incidence of major adverse cardiac events, including myocardial infarction (p = 0.581), repeated target vessel revascularization (p < 0.001), or death (p = 0.206) was higher in the PCI group. This difference consisted basically of the need for repeated target vessel revascularization. Patient-based quality-of-life assessment (SF-36) was independent from the primary chosen revascularization method.

CONCLUSIONS

At midterm follow up, MIDCAB resulted in significantly superior results regarding the need for repeated target vessel revascularization compared with PCI, with no significant differences regarding other major cardiac events.

Transthoracic Doppler validation in mammary artery grafts after minimal invasive direct coronary artery bypass operation

OBJECTIVE

This study was performed to validate noninvasive transthoracic Doppler ultrasound (TTD) with simultaneous invasive Doppler guidewire measurements in patients after minimal invasive direct coronary artery bypass operation.

METHODS

A total of 14 patients were examined 3 to 8 days after minimal invasive direct coronary artery bypass operation. TTD was performed to measure systolic and diastolic peak velocities of the left internal mammary artery (LIMA) at rest and during adenosine-induced hyperemia. Simultaneous Doppler guidewire measurements were performed.

RESULTS

LIMA flow was detected in 12 of 14 patients (86%). There was high agreement between TTD and Doppler guidewire measurements of LIMA flow velocities (systolic peak velocity: r = 0.86, y = 11.3 + 0.82x +/- 7.9; diastolic peak velocity: r = 0.95, y = 5.7 + 1.02x +/- 7.5; average peak velocity: r = 0.95, y = 5.2 + 0.94x +/- 5.4; and flow velocity reserve: r = 0.97, y = 5.2 + 0.99x +/- 4.5).

CONCLUSION

TTD represents an accurate method to evaluate flow velocities and flow velocity reserve of LIMA bypass grafts even in the early phase after minimal invasive direct coronary artery bypass operation.

Quality of life and coping following minimally invasive direct coronary artery bypass (MIDCAB) surgery

Minimally invasive direct coronary artery bypass (MIDCAB) surgery has been shown to be a promising technique for surgical treatment of single or double vessel disease. However, little is known about quality of life, mood state or coping in this group of patients. The records of 55 consecutive patients who underwent MIDCAB surgery at Harefield Hospital between April 1999 and May 2001 were reviewed. In order to assess quality of life, mood state and coping, patients were contacted by telephone to conduct a semi-structured interview and were subsequently sent four questionnaires. The measures used were the Hospital Anxiety and Depression Scale, the Short Form Health Survey, the WHOQoL-BREF and the COPE. Forty-eight patients were contacted by telephone, forty-four of whom returned the completed questionnaires. Overall ratings of quality of life were excellent for the majority of patients, and rates of anxiety and depression were lower than previously found following coronary artery bypass surgery. It is concluded that following MIDCAB surgery quality of life and mood state outcomes are encouraging. However, a prospective, longitudinal study is now required to further elucidate the relationship between quality of life, mood state and coping and to identify predictive factors for physical and psychological outcome following this new surgical technique.

The clinical outcome and quality of life following minimally invasive direct coronary artery bypass surgery

BACKGROUND

Minimally invasive direct coronary artery bypass (MIDCAB) through a limited anterior small thoracotomy has been shown to be a promising technique of surgical treatment for single or double vessel disease. Little is known about the Health-Related Quality Of Life (HRQOL) in this group of patients.

METHODS

The records of 75 consecutive patients who underwent MIDCAB procedure at Harefield Hospital between April 2000 and January 2002 were reviewed retrospectively. HRQOL assessment was planned in a cross-sectional design. Patients were contacted by telephone to conduct a semi-structured interview and were sent two questionnaires: the Short Form health survey (SF-36) and the Hospital Anxiety and Depression Scale (HADS).

RESULTS

There was no in-hospital death. Patients stayed in the Intensive Therapy Unit (ITU) for 11.56 +/- 4.55 hours and stayed in hospital for 3 +/- 2.34 days. None of the study patients had perioperative myocardial infarction (MI) or neurological complications including permanent and transient strokes. We were able to contact all the 75 patients by telephone and they also completed the SF-36 and HADS. The SF-36 scores were compared to an age-matched group of normal British people. The MIDCAB group had an excellent general health perception compared to the normal group (p < 0.001), but similar scores otherwise. The HADS scores showed that only 1 patient (1.3%) had mild depression, 5 patients (6.7%) had mild anxiety, and 2 patients (2.6%) had moderate anxiety.

CONCLUSION

MIDCAB is a safe surgical treatment and provides excellent clinical and HRQOL outcomes.

Manual control and tracking--a human factor analysis relevant for beating heart surgery

Manual control and tracking are fundamental to human factors and define a metric framework which determines the limits of surgical precision. This review provides a brief analysis of factors that are relevant for targeted motions. Knowing and accepting the limitations of human performance may help to optimize performance in off-pump surgery.

Current status and future directions in computer-enhanced video- and robotic-assisted coronary bypass surgery

Since 1997, both the Cleveland Clinic and London Health Sciences Centre groups have embraced robotic assistance and more recently demonstrated the efficacy of this technology in totally closed-chest, beating heart myocardial revascularization. This endeavor involved an orderly progression and the learning of new surgical skill sets. We review the evolution of robot-enhanced coronary surgery and forecast the future of endoscopic and computer-enhanced, robotic-enabling technology for coronary revascularization. This report describes a computer-assisted totally closed-chest coronary bypass operation, and preliminary results are discussed. The internal thoracic artery (ITA) was harvested through three 5-mm access ports and prepared and controlled endoscopically. A prototype sternal elevator was used to increase intrathoracic working space. A 10-mm endoscopic stabilizer was placed through the second intercostal space, and the left anterior descending coronary artery was controlled with silastic snares. Telerobotic anastomoses were completed end-to-side using custom-made, double-armed 8-0 polytetrafluroethylene sutures. To date, 84 patients have undergone successful myocardial revascularization with robotic assistance with a 0% surgical mortality rate. ITA harvest, anastomotic, and operating times for the entire group have been longer than for conventional surgery at 61.3 +/- 17.9 minutes, 28.5 +/- 28.2 minutes, and 368 +/- 129 minutes, respectively. Bleeding, ventilatory times, arrhythmias, hospital lengths of stay, and return to normal activity have been reduced. Recently, we have developed a new robotic revascularization strategy called Atraumatic Coronary Artery Bypass that is a promising mid-term step on the pathway to totally endoscopic, beating-heart coronary artery bypass. We conclude that computer-enhanced robotic techniques are safe, and further clinical studies are required to define the full potential of this evolving technology.

Limited-access surgical coronary artery revascularization

The continued evolution of surgical revascularization has resulted in much less invasive alternatives for patients undergoing coronary artery bypass grafting. In particular, techniques and technologies have been developed to allow for the grafting of coronary arteries through limited access incisions without the circulatory support of cardiopulmonary bypass. The conduits are generally arterial rather than the venous alternatives used originally, and the harvesting of these conduits is performed through limited access incisions described in another article in this review. The result of these efforts is sternal-sparing solutions for the off-pump coronary artery bypass grafting of all the various coronary locations on the heart. This is accomplished through a spectrum of small incisions that can directly expose any specific area of interest for focal bypass grafting. The surgical insult is greatly reduced and the patient's recovery is significantly enhanced. These efforts continue to bring us closer to the ultimate goal of 24-hour hospital stays for coronary artery bypass grafting patients.

Computer-enhanced "robotic" cardiac surgery: experience in 148 patients

OBJECTIVE

A computer-enhanced instrumentation system was used in 148 patients to minimize access in cardiac surgical procedures.

METHODS

The da Vinci telemanipulation system (Intuitive Surgical, Mountain View, Calif) provides a high-resolution 3-dimensional videoscopic image and allows remote, tremor-free, and scaled control of endoscopic surgical instruments with 6 degrees of freedom. By April 2000, the system had been used in 131 patients for coronary artery bypass grafting and 17 patients for mitral valve repair. In the coronary bypass group, the system was used in one of three ways: (1) to take down the internal thoracic artery followed by a minimally invasive direct coronary bypass procedure (n = 81); (2) to perform the anastomosis between the internal thoracic artery and the left anterior descending coronary artery in standard-sternotomy coronary bypass (n = 15); or (3) for total endoscopic coronary artery bypass grafting to anastomose the left internal thoracic artery to the left anterior descending on the arrested heart (n = 27) or the beating heart (n = 8). In 17 patients with nonischemic mitral valve insufficiency the mitral valve was repaired. Closed-chest cardiopulmonary bypass with cardioplegic arrest (Port-Access technique; Heartport, Inc, Redwood City, Calif) was used for arrested-heart total endoscopic coronary bypass and mitral valve repair.

RESULTS

The da Vinci system allows for precise tissue handling and enables the endoscopic performance of cardiac surgical tasks that require a high degree of dexterity (coronary anastomosis, mitral valve repair). No technical mishaps have occurred. The internal thoracic artery was successfully taken down in 79 of 81 patients in the group undergoing minimally invasive coronary bypass and, after a steep learning curve, is currently performed in less than 40 minutes. The postoperative patency rate is 96.3%. Total endoscopic coronary bypass was completed in 22 of 27 cases with 95.4% patency as demonstrated by angiography at 3 months' follow-up. Closed-chest endoscopic beating-heart bypass grafting was successfully performed in 2 out of 8 patients with the use of a new endoscopic stabilizer. In the group having mitral valve repair, primary endoscopic computer-enhanced repair was successfully completed in 14 of 17 patients; three others had to be changed to a standard endoscopic technique, including 1 who required valve replacement. At 3 months' follow-up, 1 additional patient underwent early reoperation for recurrent mitral insufficiency. Overall early and late mortality in this cohort of 148 patients was 2.0% and was not related to the use of the system.

CONCLUSION

In conclusion, computer-enhanced endoscopic cardiac surgery can be performed safely in selected patients. Internal thoracic artery takedown is now routinely performed with good results. Total endoscopic coronary bypass is feasible on the arrested heart but does not offer a major benefit over the minimally invasive direct approach because cardiopulmonary bypass is still required. The early clinical experience with closed-chest beating-heart bypass grafting outlines the limitations of this approach despite some procedural success.

Contrast-enhanced magnetic resonance angiography of mammary artery grafts after minimally invasive coronary bypass surgery

BACKGROUND

The aim of the study was to investigate the application of the contrast-enhanced magnetic resonance angiography (CE-MRA) for the visualization of left internal mammary artery (LIMA) bypass.

METHODS

A total of 30 patients with LIMA bypass (22 men, 8 women, 35 to 77 years) received a CE-MRA 4 to 20 days after surgery. The non-ECG-triggered CE-MRA was performed during expiration using a body array coil at a 1.5 Tesla scanner (Magnetom-Vision). A three-dimensional gradient-echo sequence with slice interpolation technique was applied. For the three-dimensional visualization, single coronal slices were postprocessed with maximal intensity projection. Of 30 patients 22 agreed to a comparative coronary angiography.

RESULTS

Five bypasses were identified up to the end-to-side anastomosis. A total of 80% of the bypass course was detectable in 13 patients and 60% in 11 patients. In two LIMA bypasses only 30% of the proximal part could be viewed; one was found by conventional coronary angiography to be occluded. The other conventional coronary angiography showed the LIMA bypass to be patent.

CONCLUSIONS

The complete course of the LIMA bypass to the left anterior descending coronary artery can be visualized by the MRA technique. The most reliable imaging of the distal anastomosis can be realized by reducing the negative influence of the beating heart.

Minimally invasive coronary artery revascularization on the beating heart

BACKGROUND

The quality of surgical beating heart revascularization is frequently questioned, especially when the surgical access is limited. Nevertheless, the number of off-pump coronary procedures is expanding worldwide.

METHODS

Since getting started with minimally invasive direct coronary artery bypass to anterior myocardial vessels in June 1996, 306 patients received left internal mammary artery grafting through an anterior minithoracotomy. Risk increasing comorbidities were present in 168 of them. Particular attention was paid to early postoperative angiographic results and complications.

RESULTS

The 30-day mortality summed up at 1.0% and was limited to patients with additional risks for conventional bypass grafting. Early postoperative control angiographies in 232 patients confirmed a global patency rate of 97.8%, revealing in addition four unexpected malinsertions to diagonal branches. In surviving patients major complications like myocardial infarction, stroke, or multiorgan failure were completely absent.

CONCLUSIONS

Minimally invasive direct coronary artery bypass grafting appears to allow for a safe and effective revascularization of the left anterior descending artery by use of the left internal mammary artery. Especially patients with risk increasing comorbidities should benefit from this approach, provided the surgical indication based on a dominating left anterior descending artery lesion. Angiographic minimally invasive direct coronary artery bypass results seem to fulfill the expectations generated by results obtained in conventional left internal mammary artery grafting and appear to be superior to interventional means.

The revival of surgical treatment for isolated proximal high grade LAD lesions by minimally invasive coronary artery bypass grafting

BACKGROUND

Percutaneous coronary angioplasty (PTCA) and stent implantation have become the first-line intervention for patients with isolated proximal LAD-lesions. Minimally invasive direct coronary artery bypass surgery (MIDCAB) has recently been developed to reduce surgical invasiveness for single LAD revascularization. This study focus on the question whether MIDCAB could be an alternative treatment for isolated proximal LAD lesions.

METHODS

Starting in 1996, MIDCAB was performed in 618 patients. Angiography was performed before discharge and repeated after 6 months at follow-up examination. In an ongoing randomized trial 150 patients with an indication for treatment of a LAD lesion have been included to compare the mid-term outcome after PTCA (n=79) vs. MIDCAB (n=71).

RESULTS

In 618 MIDCAB procedures 30-day mortality was 0.6%, perioperative myocardial infarction rate was 1.6%. The conversion rate to sternotomy was 3.4%. The learning curve was demonstrated by a patency rate of 96.0% in 1997, 98.0% in 1998 and 99.1% in 1999, respectively. At 6 months patency rate was 94.4% in 1997 and 97.0% in 1998. The rate of severe stenosis >75% dropped from 5.4% in 1997 to 3.4% in 1998. The over all rate of reinterventions was 5.6%. The preliminary result of the randomized trial revealed a difference in the number of perioperative adverse events, 11.4% in the MIDCAB group vs. 6.3% in the PTCA group (P<0.05). At 6 months follow-up 88. 7% of the MIDCAB patients were free from angina vs. 58.2% of the PTCA patients (P<0.02). Restenosis and a positive stress test was diagnosed in 27.9% of the PTCA patients vs. 8.4% of the MIDCAB patients (P<0.02). Reintervention was necessary in 27.9% of the patients after PTCA vs. 8.4% of the patients after MIDCAB.

CONCLUSION

MIDCAB is a safe and effective but technically demanding procedure. Perioperative adverse events may be expected, but early as well as mid-term patency rate are good. When compared to PTCA, the freedom from angina and the need for additional revascularization procedures after 6 months is statistically better for patients having MIDCAB surgery. Thus, MIDCAB is considered a valuable alternative for isolated proximal high grade LAD lesions.

Difficulties in the interpretation of coronary angiogram early after coronary artery bypass surgery on the beating heart

OBJECTIVE

The major objective of this study was to evaluate the findings in early postoperative coronary angiography in patients who underwent coronary revascularization on the beating heart without cardiopulmonary bypass.

METHODS

Eighty-four consecutive patients receiving 113 grafts were studied. A coronary angiography was performed 0 to 5 days postoperatively. All the grafts were reviewed and classified in the following way: grade A (unimpaired run-off); grade B1 (<50 stenosis); grade B2 (>50% stenosis); grade O (occlusion). A second coronary angiography was performed in patients with a stenosis grade B2, 4 to 30 months postoperatively. An exercise test was performed by patients with B1 stenosis.

RESULTS

Overall graft patency was 96% in the 113 grafts. None of the 14 patients with B1 stenosis in the early coronary angiography had any clinical signs of ischemia. Eight of the 12 patients who exhibited B2 stenosis either at the anastomotic site, in the graft or in the distal coronary artery at the first coronary angiography had a normal angiogram at the re-angiography.

CONCLUSION

A majority of stenoses visualized at the early coronary angiography could not be seen at a later coronary angiography, which makes the interpretation of the angiogram unreliable as a tool for the decision as to redo-procedure in the early postoperative period.

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.