Video assisted coronary bypass surgery

Five-Year Survival of Patients Treated with Minimally Invasive Direct Coronary Artery Bypass (MIDCAB) Compared with the General Swiss Population

BACKGROUND

 To evaluate the midterm follow-up and 5-year survival outcome of the minimally invasive direct coronary artery bypass (MIDCAB) procedure compared with the survival of the general Swiss population.

METHODS

 Retrospective study on preoperative data, intraoperative data, and postoperative outcome of patients who underwent MIDCAB surgery between June 2010 and February 2019. To assess validity of this surgical therapy, outcomes were compared with survival data of a gender- and age-matched cohort of the general Swiss population taken from the database of the Swiss Federal Statistical Office.

RESULTS

 A total of 88 patients were included. Median (interquartile range [IQR[) age was 66 (56-75) years, and 27% (n = 24) were female. The median (IQR) length of the in-hospital stay was 7 (6-8) days. No postoperative stroke occurred. The 30-day mortality was 1.1% (n = 1). Reintervention for failed left internal mammary artery was needed in 1.1% (n = 1). The median (IQR) ejection fraction was 58% (47-60) preoperatively and remained stable during follow-up. The median (IQR) follow-up period was 3 (1.1-5.2) years. Five years postoperatively, 83% (confidence interval, 69-91) of the patients were alive, showing an overlap with the range of survival of the matched subcohort of the general Swiss population (range, 84-100%).

CONCLUSION

 Though suffering from coronary heart disease, patients after MIDCAB show almost equal survival rates as an equivalent subcohort corresponding to the general Swiss population matched on age and gender. Thus, our data show this treatment to be safe and beneficial.

Minimal-Access Coronary Revascularization: Past, Present, and Future

Minimal-access cardiac surgery appears to be the future. It is increasingly desired by cardiologists and demanded by patients who perceive superiority. Minimal-access coronary artery revascularisation has been increasingly adopted throughout the world. Here, we review the history of minimal-access coronary revascularization and see that it is almost as old as the history of cardiac surgery. Modern minimal-access coronary revascularization takes a variety of forms-namely minimal-access direct coronary artery bypass grafting (MIDCAB), hybrid coronary revascularisation (HCR), and totally endoscopic coronary artery bypass grafting (TECAB). It is noteworthy that there is significant variation in the nomenclature and approaches for minimal-access coronary surgery, and this truly presents a challenge for comparing the different methods. However, these approaches are increasing in frequency, and proponents demonstrate clear advantages for their patients. The challenge that remains, as for all areas of surgery, is demonstrating the superiority of these techniques over tried and tested open techniques, which is very difficult. There is a paucity of randomised controlled trials to help answer this question, and the future of minimal-access coronary revascularisation, to some extent, is dependent on such trials. Thankfully, some are underway, and the results are eagerly anticipated.

Quality of life in patients undergoing minimally invasive cardiac surgery: a systematic review

Objective

Minimally invasive procedures have been developed to reduce surgical trauma after cardiac surgery. Clinical recovery is the main focus of most research. Still, patient-centred outcomes, such as the quality of life, can provide a more comprehensive understanding of the impact of the surgery on the patient's life. This systematic review aims to deliver a detailed summary of all available research investigating the quality of recovery, assessed with quality of life instruments, in adults undergoing minimally invasive cardiac surgery.

Methods

All randomised trials, cohort studies, and cross-sectional studies assessing the quality of recovery in patients undergoing minimally invasive cardiac surgery compared to conventional cardiac surgery within the last 20 years were included, and a summary was prepared.

Results

The randomised trial observed an overall improved quality of life after both minimally invasive and conventional surgery. The quality of life improvement in the minimally invasive group showed a faster course and evolved to a higher level than the conventional surgery group. These findings align with the results of prospective cohort studies. In the cross-sectional studies, no significant difference in the quality of life was seen except for one that observed a significantly higher quality of life in the minimally invasive group.

Conclusions

This systematic review indicates that patients may benefit from minimally invasive and conventional cardiac surgery, but patients undergoing minimally invasive cardiac surgery may recover sooner and to a greater extent. However, no firm conclusion could be drawn due to the limited available studies. Therefore, randomised controlled trials are needed.

All we need to know about internal thoracic artery harvesting and preparation for myocardial revascularization: a systematic review

Internal thoracic arteries (ITAs) are the gold standard conduits for coronary revascularization because of their long-term patency and anti-atherosclerotic properties. Harvesting and preparation of ITAs for revascularization is a technically demanding procedure with multiple challenges. Over the last few decades, various methods and techniques for ITAs harvesting have been introduced by different surgeons and applied in clinical practice with different results. Harvesting of ITAs in pedicled or skeletonized fashion, with electrocautery or harmonic scalpel, with open or intact pleura, with clipping the end or keeping it perfused; papaverine delivery with intraluminal injection, perivascular injection, injecting into endothoracic fascia, and papaverine topical spray are the different techniques introduced by the number of researchers. At the same time, access to the ITAs for harvesting has also been studied. Access and harvesting through median sternotomy, mini anterolateral thoracotomy, thoracoscopic, and robotic-assisted harvesting of ITAs are the different techniques used in clinical practice. However, the single standard method for harvesting and preparation of ITAs has yet to be determined. In this review article, we aimed to discuss and analyze all these techniques of harvesting and preparing ITAs with the help of literature to find the best way for ITAs harvesting and preparation for myocardial revascularization.

Left thoracotomy approach for off-pump coronary artery bypass grafting surgery: 15 years of experience in 2500 consecutive patients

OBJECTIVES

Our goal was to describe the experience at 2 centres with off-pump coronary artery bypass grafting using a left thoracotomy.

METHODS

From January 2002 to December 2017, a total of 2528 consecutive patients (578 women, mean age 62.3 ± 9.1 years) were operated on using this technique. Data were collected prospectively and analysed retrospectively.

RESULTS

There were no conversions to median sternotomy and 6 patients (0.2%) were converted to on-pump CABG. The mean number of grafts per patient was 2.8 ± 0. 9. The 30-day mortality rate was 1.0% (25 patients). Most patients were extubated in the operating theatre (97.3%), and 47 patients (1.9%) needed re-exploration for bleeding. Seven patients (0.3%) experienced a cerebrovascular event; 4 (0.3%) had a postoperative myocardial infarction; and 84 (3.4%) had new-onset atrial fibrillation. A total of 1510 patients (61.1%) were discharged from the hospital in the first 48 h after surgery. Long-term survival rates were 98.8%, 93.6% and 69.1% at 1, 5 and 10 years, respectively (central image). During the follow-up period, 60 patients (2.9%) were re-examined for recurrence of angina with a new coronary angiogram; of those, 24 (1.2%) required percutaneous coronary intervention and 11 (0.5%) had redo surgery.

CONCLUSIONS

A left thoracotomy is a safe alternative to a median sternotomy for coronary artery bypass grafting on the beating heart, with low early complications and good mid- and long-term results.

A minimally invasive robotic surgery approach to perform totally endoscopic coronary artery bypass on beating hearts

The currently available robotic systems rely on rigid heart stabilizers to perform totally endoscopic coronary artery bypass (TECAB) surgery on beating hearts. Although such stabilizers facilitate the anastomosis procedure by immobilizing the heart and holding the surgery site steady, they can cause damage to the heart tissue and rupture of the capillary vessels, due to applying relatively large pressures on the epicardium. In this paper, we propose an advanced robotic approach to perform TECAB on a beating heart with minimal invasiveness. The idea comes from the fact that the main pulsations of the heart occur as excursions in normal direction, i.e., perpendicular to the heart surface. We devise a 1-DOF flexible heart stabilizer which eliminates the lateral movements of the heart, and a 1-DOF compensator mechanism which follows the heart trajectory in the normal direction, thus canceling the relative motion between the surgical tool and the heart surface. In fact, we bring a compromise between two radical approaches of operating on a completely immobilized beating heart with no heart motion compensation, and operating on a freely beating heart with full compensation of heart motion, considering the invasiveness of the first and the technical challenges of the second approach. We propose operating on a partially stabilized beating heart with unidirectional compensation of the heart motion; the flexible stabilizer would exert much less holding force to the heart tissue and the robotic system with unidirectional compensator would be technically feasible. In the proposed approach, a motion sensor mounted on the stabilizer measures the heart excursion data and sends it into a control unit. A predictive controller uses this data to generate an automated trajectory. The slave robots follow this trajectory, which is superimposed on the surgeon's tele-operation commands received from a master console. Finally, the tool-activation units in the slave robots actuate the articulated laparoscopic tools to perform the anastomosis procedure. The evaluation of the hypothesis showed that our solution for the robotic TECAB on beating heart is both practical and cost effective. We showed in an in-vivo study that the flexible stabilizer can effectively restrict the heart lateral movements, while allowing for its normal excursion. We found readily available linear motors which could afford the high forces, speeds and accelerations required for following the heart trajectory. Finally, we showed that the tool-activation unit is capable of providing the maneuverability and workspace required for the most challenging task of CABG procedure, i.e., anastomosis suturing.

A review of hybrid coronary revascularization

Purpose

Hybrid coronary revascularization is an emerging treatment strategy for coronary artery disease. We will review the reasons for the development of this strategy, describe surgical techniques, and review outcomes. Finally, we will discuss the future of hybrid revascularization and explain why it will grow as a treatment modality.

Methods

For this review, we conducted an unstructured review of the literature for articles related to hybrid coronary revascularization, bypass surgery, and percutaneous coronary interventions.

Results

Hybrid coronary revascularization has been shown in large series to have excellent results. These include fast recovery time, low mortality and rates of complications, and excellent surgical graft patency. There may be increased need for revascularization over conventional bypass surgery.

Conclusions

The combination improved surgical techniques including a robotic surgery platform, as well as the ever-improving efficacy and durability of coronary stents have made hybrid coronary revascularization an attractive option for many patients. It offers a minimally invasive approach to surgery while avoiding the poor patency of saphenous vein grafts. In appropriately selected patients, this may be an ideal treatment strategy that minimizes risks and maximizes short- and long-term benefits.

Hybrid coronary revascularization for the treatment of multivessel coronary artery disease

Coronary artery disease (CAD) has typically been treated either medically, with percutaneous coronary intervention (PCI), or with coronary artery bypass grafting (CABG). As advances in stent technology and minimally invasive surgery have developed, a third option has emerged: hybrid coronary revascularization (HCR). In HCR, minimally invasive CABG and PCI are both employed to treat a single patient, often during the same hospital stay. Patients appropriate for this technique vary widely, from low-risk patients with low SYNTAX lesions outside the left anterior descending artery (LAD), to high-risk patients with multiple comorbidities who are felt by the heart team to benefit most by avoiding a sternotomy. Across both our experience and other series in the literature, mortality with HCR is around 1%. Hospital length of stay is less than one week, and typically less than after conventional CABG, but longer than with isolated PCI. Return to baseline activity is substantially shorter after minimally invasive CABG compared to conventional CABG due to the avoidance of a sternotomy; deep sternal wound infections are entirely avoided. Mid-term need for repeat revascularization may be higher with HCR, though randomized data are lacking. In conclusion, HCR is an evolving method to treat multivessel CAD with favorable early results in high volume centers, though growth in the field is limited by surgical experience and success with minimally invasive techniques.

Minimally invasive direct coronary bypass surgery via distal mini-sternotomy : Promising clinical results with anaortic, multivessel, all-arterial technique

BACKGROUND

Minimally invasive direct coronary artery bypass grafting (MIDCAB) was developed to decrease perioperative morbidity, some of which may be related to the use of cardiopulmonary bypass and to cross-clamping of the aorta. We report our initial experience with multivessel MIDCAB via distal mini-sternotomy (DIMS). DIMS is performed to gain access to the left and right internal thoracic arteries and to reach the left anterior descending coronary artery (LAD), diagonal branches, and right coronary artery (RCA).

METHODS

Between January 2016 and January 2017, 12 patients with significant coronary artery disease of the LAD and the RCA underwent multivessel, all-arterial MIDCAB through a distal midline skin incision from the fourth intercostal space to the xyphoid process, with L‑ or T‑shaped division of the sternum. The mean age of the patients was 61.5 ± 5.2 years (range: 52-71 years).

RESULTS

We performed all-arterial revascularization using the left internal mammary artery in 12 patients, the radial artery in ten, and the right internal mammary artery in two patients. The mean number of grafts per patient was 2.08 ± 0.4 (range: 2-3). The mean length of the skin incision was 8.5 ± 1.3 cm (range: 7-11 cm). There was no perioperative ischemia, postoperative bleeding, or arrhythmia events. No postoperative cognitive dysfunction occurred. The mean hospital stay was 5.6 days. No major adverse cardiac events (MACE) occurred at the 12-month follow-up. At follow-up, all patients were in New York Heart Association class I and there were no wound complications.

CONCLUSION

Although MIDCAB-DIMS is technically more demanding than conventional procedures and our experience is limited, we conclude that this technique can be used safely in selected patients, with promising 12-month follow-up results.

Minimally Invasive Approach for Left Atrial Myxoma

A 32-year-old female with left atrial myxoma who was in New York Heart Association functional class IV, underwent a minimally invasive excision of the tumor through a right parasternal approach. Early follow-up demonstrated that this technique was effective and had the benefits of low cost, rapid recovery, decreased hospital stay, and a good cosmetic result.

Reviewing hybrid coronary revascularization: challenges, controversies and opportunities

Two main approaches to myocardial revascularization currently exist, coronary artery bypass and percutaneous coronary intervention. In patients with advanced coronary artery disease, coronary artery bypass surgery is associated with improved long term outcomes while percutaneous coronary intervention is associated with lower periprocedural complications. A new approach has emerged in the last decade that attempts to reap the benefits of bypass surgery and stenting while minimizing the shortcomings of each approach. This new approach, hybrid coronary revascularization, has shown encouraging early results. Minimally invasive techniques for bypass surgery have played a large part of bringing this approach into contemporary practice.

Coronary artery bypass grafting: Part 1--the evolution over the first 50 years

Surgical treatment for angina pectoris was first proposed in 1899. Decades of experimental surgery for coronary artery disease finally led to the introduction of coronary artery bypass grafting (CABG) in 1964. Now that we are approaching 50 years of CABG experience, it is appropriate to summarize the advancement of CABG into a procedure that is safe and efficient. This review provides a historical recapitulation of experimental surgery, the evolution of the surgical techniques and the utilization of CABG. Furthermore, data on contemporary clinical outcomes are discussed.

Off-pump coronary artery bypass grafting as re-do surgery in two cases in which the right gastroepiploic artery was grafted to the right coronary artery

Transdiaphragmatic off-pump coronary artery bypass grafting (OPCAB) to the right coronary artery, is an effective way to reduce the risks of second bypass surgery as well as the risk of graft injury after coronary artery bypass grafting (CABG). We report two cases of successful OPCAB as re-do surgery in which the right gastroepiploic artery (RGEA) was grafted to the right coronary artery. The first case was a 58-year-old woman, who underwent CABG 10 years ago. OPCAB (RGEA to right coronary artery) was performed since myocardial perfusion scintigraphy revealed ischemia in the inferior wall. The second case was a 67-year-old man who had hypertension, hyperlipidemia, peripheral arterial disease, and was undergoing dialysis (for 6 years). Six years previously, he developed a mycotic aneurysm of the right coronary artery and underwent open-heart surgery. He often had episodes of angina at night or during dialysis, and then developed congestive heart failure and was hospitalized. Since ischemia was considered to be in the inferior wall, the RGEA was grafted to the right coronary artery.

Current state of surgical myocardial revascularization

Despite increasing competition from percutaneous interventions and other novel methods of non-surgical coronary revascularization, coronary artery bypass grafting (CABG) remains one of the most definitive and durable treatments for coronary artery disease, especially for those patients with extensive and diffuse disease. In recent years the CABG procedure itself has undergone innovation and evolution. This review article provides a brief historical perspective on the procedure, and examines the current state of modern variations including off-pump, limited-access, and robotic-assisted CABG.

[Rupture of the internal thoracic artery 6 weeks after MIDCAB operation]

The minimally invasive coronary bypass operation is a procedure that has been firmly established in cardiac surgery for several years now. Only a few reports exist regarding the complications of this procedure. This case study reports on a 51-year-old man who collapsed 27 days after a left-sided internal mammary artery bypass on the anterior interventricular artery, when the bypass vessel ruptured. After pericardial puncture and cardiopulmonary resuscitation the patient was transported via air ambulance to a cardio-surgical center where he was successfully operated upon.

Mid-term outcomes of off-pump versus on-pump coronary artery bypass graft surgery

OBJECTIVE

To evaluate survival and readmissions to hospital for cardiac events or coronary revascularization (REVASC) in patients having off-pump (OPCAB) versus conventional on-pump (CCAB) coronary artery bypass graft surgery (CABG).

METHODS

Of 11,368 consecutive patients undergoing isolated CABG between 1996 and 2002, 514 had OPCAB surgery. Using propensity scores, 503 CCAB patients were randomly matched to 503 OPCAB patients.

RESULTS

There were no clinical or statistical differences between the two groups for any prognostic variable. However, OPCAB patients received significantly fewer distal anastomoses than the CCAB group (2.6+/-1.0 versus 3.1+/-1.0; P<0.001). There was no difference in operative mortality (OPCAB 1.0%, CCAB 1.4%; P=0.6), but the OPCAB group had significantly fewer operative strokes (0.2% versus 1.8%; P=0.01). Follow-up was 99.7% complete at 2.2+/-1.2 years (range 0 to 6 years). Twice as many OPCAB patients (n=24) required REVASC compared with the CCAB (n=11) group. The following five-year actuarial outcomes are presented for CCAB and OPCAB, respectively: survival: 77+/-6%, 76+/-8%, P=0.8; freedom from REVASC: 95+/-3%, 92+/-2%, P=0.02; and cardiac event-free survival: 76+/-5%, 62+/-8%; P=0.05. Cox regression revealed that OPCAB was a significant independent predictor of poorer freedom from REVASC (RR 2.2, 95% CI 1.0 to 4.6; P=0.04) and cardiac event-free survival (RR 1.6, 95%CI 1.1 to 2.2; P=0.02).

CONCLUSIONS

The use of OPCAB remains controversial. These results, from this early experience, suggest that despite improved hospital outcomes, the lesser degree of REVASC raises concerns about the need for repeat revascularization in the OPCAB group.

Myocardial perfusion imaging evidence of functionally complete revascularization by minimally invasive direct coronary artery bypass in 2-vessel coronary artery disease

BACKGROUND

Whether patency of a second diseased vessel still impacts myocardial perfusion when complete revascularization of the left anterior descending coronary artery (LAD) territory has been achieved is currently undetermined. In patients with 2-vessel coronary artery disease and complex LAD lesions, we evaluated the impact of single LAD or integrated revascularization on single photon emission computed tomography-assessed reversible myocardial ischemia.

METHODS AND RESULTS

Thirty-five candidates for revascularization with double-vessel disease including the LAD and a preoperative stress single photon emission computed tomography study were studied. Revascularization was performed by minimally invasive direct coronary artery bypass (MIDCAB) alone (n = 15) or by an integrated procedure with second-vessel angioplasty, either soon after surgery (n = 13) or at 2 months (n = 7), according to the extent of reversible perfusion defects in the second vessel territory. At 1 year, the total ischemic area decreased from 9.3 +/- 5.1 to 0.8 +/- 1.5 in MIDCAB-only patients and from 8.2 +/- 4.9 to 1.6 +/- 2.9 in the integrated group (P = .87 for treatment and P < .001 for time). The ischemic area in the second vessel territory similarly decreased in both groups (P = .81 for treatment and P < .001 for time).

CONCLUSIONS

In 2-vessel coronary artery disease involving the LAD, MIDCAB alone achieves, in a substantial proportion of patients, functionally complete revascularization even in the nonrevascularized second vessel territory.

Feasibility study of a direct endo-aortic clamp balloon

We have developed a new end-aortic clamp balloon catheter intended to be inserted directly into, thereby occluding, the ascending aorta. We examined the performance of this catheter in a canine model. We evaluated the extent of migration tolerance of the catheter under cardiopulmonary bypass perfusion in 12 mongrel dogs, weighing 20 kg, under general anesthesia. After institution of cardiopulmonary bypass, this catheter was inserted into the ascending aorta, and the balloon was inflated to occlude the ascending aorta. After the canine heart was arrested following the administration of cardioplegic solution, balloon migration was examined over a period of 3 hours, with hourly increases in perfusion pressure from 50 mm Hg to 80 mm Hg and finally to 100 mm Hg. After the migration test, ascending aortic wall sections, where the balloon was inflated, were examined microscopically. At internal balloon pressure of 300 to 400 mm Hg, migration occurred at perfusion pressure of > or =90 to 100 mm Hg. No histological differences were observed with use of the balloon catheter, compared with an extra-aortic clamp forceps. Based on these results, this device is safe, feasible, and can adequately occlude the ascending aorta during cardiopulmonary bypass. We conclude that this device is effective in patients weighing 20 kg.

The History and Development of Direct Coronary Surgery without Cardiopulmonary Bypass*

The history of direct myocardial revascularization without cardiopulmonary bypass dates to 1961 in the dawn of coronary artery surgery. With the introduction and development of techniques of extracorporeal circulation around the same time, beating heart surgery was largely abandoned. Over the subsequent decades, cardiopulmonary bypass and electromechanical cardioplegic arrest became popular as means of revascularization in a bloodless and motionless field. While coronary artery surgery on the arrested heart remained undisputed for decades, myocardial revascularization on the beating heart was pursued by a few pioneering surgeons around the world, based on the belief that coronary revascularization could be performed equally well without the detrimental effects of cardiopulmonary bypass and electromechanical arrest. Various concepts and techniques developed during the 1980s by these pioneers enabled minimally invasive coronary surgery to be performed in the early 1990s. This break from the mainstream allowed selective myocardial revascularization using a minimal incision and no cardiopulmonary bypass to develop and constructed a base for future extensive revascularizations off-pump. With the subsequent explosion of new techniques for coronary exposure and myocardial stabilization, complete revascularization without cardiopulmonary bypass became possible with consistent results. Emerging from the preview of only a few surgeons just a decade ago, off-pump surgery is currently one of the accepted modalities for complete myocardial revascularization worldwide. This paradigm shift in the approach to myocardial revascularization has led to exiting new future possibilities, such as beating heart totally endoscopic coronary artery surgery.

Innovative surgical strategies: Minimally invasive CABG and off-pump CABG

Minimally invasive coronary artery bypass grafting (CABG) and off-pump coronary artery bypass grafting (OPCAB) have made up a significant facet of the recent attempts of surgical myocardial revascularization to evolve. Driven by an effort to limit the deleterious effects of cardiopulmonary bypass (CPB), along with a response to both the growing interests in performing procedures through smaller incisions and the successes of catheter-based therapies, these therapeutic options have found themselves moving into the future by resurrecting their past. Minimally invasive CABG is the procedure by which coronary grafting is performed through a small anterior thoracotomy, without the use of CPB. Although feasible, the inability to offer a more thorough degree of revascularization has limited the applicability of this procedure and, therefore, accounts for its overall minor contribution to the number of coronary revascularizations performed annually. Conversely, as the technical feasibility of performing complete revascularization without CPB has been achieved with OPCAB, its place as a mode of therapy remains uncertain. Several clinical trials have been performed to date with only a few being done in a prospective, randomized fashion. From this data has come a mix of information regarding either improvements or, at a minimum, no change in the rate of complications between CABG with, and without, CPB, while at the same time maintaining equivalent short-term graft patencies. The question remains, however, to which patient population is this approach to CABG optimal? Our practice has largely reserved OPCAB for those patients in whom manipulation of the aorta is considered not feasible due to severe calcification or in "high-risk" patients who are felt to be unable to tolerate the adverse physiologic effects of CPB. This makes up approximately 15% of our CABG population, roughly equal to the national average, with the remaining patients being revascularized with the assistance of CPB.

Experimental coronary artery occlusion: relevance to off-pump cardiac surgery

Mechanical coronary artery occlusion is required for minimally invasive direct coronary artery bypass and off-pump coronary artery bypass surgery. It is important that the method of occlusion be minimally traumatic. Chronic effects of these methods have never been studied. Temporary occlusion of coronaries utilizing suture snare, silastic loop snare, and bulldog clamp was carried out in 12 Yucatan pigs. Three animals each were sacrificed acutely and at 3, 6, and 12 months. The area of occlusion of each vessel was examined by light microscopy and the degree of damage recorded. In the animals sacrificed acutely, there was more damage using the suture snare than with the other 2 methods, but there was minimal damage at longer intervals. There was slight damage acutely and chronically with the bulldog technique. No damage was seen acutely with the silastic loop technique, but some late damage was found. The techniques of coronary artery dissection and occlusion used for minimally invasive and off-pump bypass surgery may contribute to early postoperative graft occlusion.

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.

Coronary artery bypass surgery by the transdiaphragmatic approach

BACKGROUND

The transdiaphragmatic approach is useful for reoperative coronary artery bypass grafting involving the right coronary artery because it does not require median sternotomy or cardiopulmonary bypass.

METHODS

Twenty-one patients underwent coronary artery bypass surgery by the transdiaphragmatic approach. The ratio of first operations to reoperations was 7:14. The cause of reoperation was occlusion of a saphenous vein graft in 4 patients, right gastroepiploic artery graft failure in 3 patients, and a new sclerotic lesion in the right coronary artery in 7 patients. When the radial artery or saphenous vein was used, grafting extended from the origin of the gastroduodenal artery to the right coronary artery.

RESULTS

None of the patients died during surgery. The sites of anastomoses were as follows: right coronary artery in 11 patients, right posterior descending artery in 9 patients, and the atrioventricular node artery in 1 patient. The following types of grafts were used: right gastroepiploic artery in 17 patients, saphenous vein in 2 patients, and radial artery in 2 patients.

CONCLUSIONS

When reoperative coronary surgery involving the right coronary artery is necessary, the transdiaphragmatic technique is effective because it does not damage patent grafts placed during the primary operation.

The effect off-pump coronary artery bypass surgery on in-hospital mortality and morbidity

OBJECTIVE

Off-pump coronary artery bypass (OPCAB) surgery is being increasingly reported to show better outcomes compared to conventional on bypass grafting. We examined the effect of OPCAB on in-hospital mortality and morbidity, while adjusting for patient and disease characteristics, in four institutions in the North West of England.

METHODS

Between April 1997 and March 2001, 10,941 consecutive patients underwent isolated coronary artery bypass surgery at these four institutions. Of these, 7.7% were performed off-pump. We used logistic regression to examine the effect of OPCAB on in-hospital mortality and morbidity after adjusting for potentially confounding variables.

RESULTS

The crude odds ratio (OR) for death (off-pump versus on-pump coronary bypass grafting) was 0.48 (95% confidence interval, CI 0.26-0.92; P=0.023). After adjustment for all major risk factors, the OR for death was 0.59 (95% CI 0.31-1.12; P=0.105). Off-pump patients had a substantially reduced risk of post-operative stroke (0.6 versus 2.3%, respectively; adjusted OR 0.26 (95% CI 0.09-0.70; P=0.008) and a significant reduction in post-operative hospital stay. Other morbidity outcomes were similar in both groups.

CONCLUSIONS

Off-pump coronary artery bypass incurs no increased risk of in-hospital mortality. In contrast, there is a significant reduction in morbidity in patients undergoing off-pump coronary bypass grafting when compared to that performed on cardiopulmonary bypass.

Minimally invasive cardiac surgery by the port-access method

Recently, minimally invasive surgery has come to be an important theory in cardiac surgery, the goal of which is shortening of hospital stay, earlier recovery of employment, and cosmetics. In this paper, we will describe our experience with port-access cardiac surgery conducted under the support of our new technology. This study assesses the quality of cardiac surgery performed by the port-access method. The author developed a direct endoaortic clamp balloon (Yozu balloon). This balloon is a triple-lumen balloon catheter of 3.6 mm in outer diameter and 40 cm in full length. The balloon is inserted directly into the ascending aorta. Injection of cardioplegic solution and aortic vent can be conducted. Also, we introduce a modified Cosgrove flex clamp to apply in small-incision surgery, aiming at a less invasive procedure. The modified point is that the original, united Cosgrove flex clamp can be divided into the handle part equipped with a ratchet, and the bellows part equipped with a clamp jaw. By this modification, it became possible to apply the Cosgrove flex clamp transthoracically; that is, it became possible to conduct aortic clamping safely and securely through this small port of 8 mm in diameter. Port-access cardiac surgery is one of the developing and promising methods of cardiac operation. In view of future technological progress, we can expect the gradual but wide popularization of this method.

Comparison of the postoperative blood flow waveforms of the bypassing grafts in patients following minimally invasive direct coronary artery bypass

PURPOSE

To use Doppler ultrasound velocimetry to detect and compare the postoperative flow characteristics of the bypassing grafts in patients following minimally invasive direct coronary artery bypass surgery (MIDCAB).

MATERIALS AND METHODS

From January 1997 to June 1999, 34 patients underwent MIDCAB with the left internal thoracic artery (LITA) to the left anterior descending coronary artery (LAD) [n = 23], with the right gastroepiploic artery (RGEA) to the right posterior descending artery (RPD) [n = 3], or with the LITA with a saphenous vein graft extension to the LAD (n = 6), the diagonal coronary artery (n = 1), or the right acute coronary artery (n = 1). There were two patients with LITA to the LAD and RGEA to the RPD. Patients underwent MIDCAB due to coronary artery stenosis (100% occlusion, n = 10; 90 to 99% stenosis, n = 18; < 90% stenosis, n = 5) or unsuccessful percutaneous transcoronary angioplasty with dissection (n = 1). All patients underwent flow velocity measurement by Doppler ultrasound velocimetry in the immediate postoperative period, and at 6-month and 12-month intervals; graft flows were quantified based on Doppler velocimetric data.

RESULTS

The results showed that in a patient with a totally occluded LAD or RPD, typical biphasic velocity waveforms were consistently observed. However, a delayed diastolic wave was noted in RGEA grafts. In patients with less-occluded stenotic lesions or with strong back flows, the flow velocity patterns showed biphasic waveforms but systolic reversal was observed in the area closest to the anastomotic site.

CONCLUSION

The presence of an LAD or RPD stenosis proximal to the anastomotic site significantly affects the LITA or RGEA graft flow volume. The biphasic flow pattern proves that an LITA or RGEA graft transports the blood primarily to coronary arteries during the diastolic phase.

Totally endoscopic coronary artery bypass on the beating heart

Our aim was to develop a technique for totally endoscopic coronary artery bypass on the beating heart for patients with coronary artery disease. For this procedure, operations were performed through four thoracoports. The left internal thoracic artery (LITA) was harvested thoracoscopically. The pericardium was then opened and the left anterior descending artery (LAD) identified. The endoscopic stabiliser was inserted and transformed into a coiled ring shape. After suction, sufficient immobilisation of the LAD was achieved. The proximal snare was placed using a 5-0 Prolene suture to give a bloodless field. After blunt dissection of the coronary artery, an arteriotomy was performed with a sharp blade and enlarged with endoscopic Potts scissors. Using an endoscopic needle holder and forceps via two thoracoports at the fourth intracostal space, a conventional end-to-side anastomosis was safely created with an 8-0 Prolene single running suture. Total endoscopic beating-heart bypass grafting, including ITA harvest, stabilisation, arteriotomy and performance of the anastomosis, was performed successfully in three patients. There were no intraoperative arrhythmias, and no postoperative haemorrhage. The patients required no intensive care management postoperatively. All patients were ready for discharge on the fourth postoperative day. Postoperative angiogram revealed that anastomoses are patent. We conclude that the endoscopic stabiliser can sufficiently immobilise the heart to enable endoscopic beating-heart coronary artery bypass grafting by means of an easily controllable instrumentation system.

Interleukin-1, interleukin-6 and myocardial enzyme response after coronary artery bypass grafting - a prospective randomized comparison of the conventional and three minimally invasive surgical techniques

OBJECTIVE

In order to evaluate the traumatic effects of median sternotomy and cardiopulmonary bypass (CPB) in conventional and minimally invasive coronary artery bypass grafting, inflammatory response was studied in a prospective randomized trial in patients referred to single-vessel coronary artery bypass grafting.

METHODS

Four surgical techniques were compared: group 1, median sternotomy with CPB in ten patients (eight male, two female; aged 59.6+/-11.0 years (mean+/-SD)); group 2, median sternotomy and off-pump in ten patients (seven male, three female; aged 65.1+/-10.0 years); group 3, minithoracotomy with CPB in ten patients (seven male, three female, aged 61.2+/-10.4 years); group 4, minithoracotomy and off-pump in ten patients (nine male, one female, aged 62.9+/-9.8 years). All patients received a left internal mammary artery graft to the left anterior descending artery (LAD). Clinical data, perioperative values of cytokines and cardiac enzymes were monitored.

RESULTS

There were no major complications. Troponin-T and creatine kinase isoenzyme MB (CK-MB) levels were significantly higher in CPB procedures (P<0.0056; multivariate general linear model). Interleukin-6 (IL-6) levels were significantly higher in minithoracotomy procedures. Interleukin-1 (IL-1) was significantly increased in all patients compared with the preoperative values.

CONCLUSIONS

The use of CPB is combined with higher levels of troponin-T and CK-MB as signs of myocardial damage. Surgical access was identified as a trigger of inflammatory response, as minithoracotomy is related to higher levels of IL-6. IL-1 increased in all procedures and this occurred independently of the surgical access or the use of CPB, which points out a potential relationship between inflammatory response and anesthesia. Neither CPB nor surgical access influenced the clinical outcome in the treatment of coronary artery single-vessel bypass grafting.

Early outcome and graft patency in mammary artery grafting of left anterior descending artery with sternotomy or anterior minithoracotomy

BACKGROUND

The main objective of this study was to retrospectively compare early outcome and graft patency in patients who underwent coronary artery bypass grafting with the internal thoracic artery to the left anterior descending artery via an anterior minithoracotomy or median sternotomy and without the use of extracorporeal circulation.

METHODS

One hundred thirty consecutive patients were studied. Median sternotomy was performed in 77 patients and anterior minithoracotomy in 53 patients.

RESULTS

There were no differences in early clinical data or persistent postoperative pain between the groups. Early graft patency was 88% in the thoracotomy group and 96% in the sternotomy group (p = 0.3). Five of 7 patients who presented with a significant stenosis at the first coronary angiography had a normal angiogram at the reangiography. None of the patients with nonsignificant stenosis at the early coronary angiography had any clinical signs of ischemia or chest pain.

CONCLUSIONS

In our experience, anterior minithoracotomy and median sternotomy are different and distinguishable regarding early outcome and early graft patency. Most of the stenoses visualized at the early coronary angiography had vanished at a later coronary angiography, which makes the interpretation of the angiogram hazardous as a tool for the decision for redo procedure in the early postoperative period.

Transabdominal mimially invasive direct coronary artery bypass grafting (MIDCAB)

The major limitations of current minimally invasive direct coronary artery bypass (MIDCAB) techniques are multivessel and distal vessel disease frequently seen in patients with extensive stent restenosis ('full metal jacket syndrome') and reoperative surgery. Two separate minimal access incisions (minithoracotomy, lower partial sternotomy) have been used to bypass two separate arteries (left internal mammary artery (LIMA) to left anterior descending (LAD), right gastroepiploic artery (RGEA) to posterior descending artery (PDA)). To bypass multiple coronary arteries using multiple arterial conduits without violation of bony parts, we use a new minimal access incision by 'transabdominal approach'.

Mini-sternotomy for off-pump coronary artery bypass grafting

The number of off-pump coronary artery bypass grafting procedures without cardiopulmonary bypass is steadily increasing. We report on a new, minimally invasive surgical approach for off-pump coronary revascularization in multivessel disease. A distal sternotomy is performed to gain access to the left and right internal thoracic arteries and to reach the left anterior descending coronary artery, diagonal branches, and right coronary artery for off-pump revascularization.

Evaluation of a new device for quick sutureless coronary artery anastomosis in surviving sheep

OBJECTIVE

A new device for performing quick sutureless vascular anastomosis by means of stent technology has recently been developed by Jomed International, Helsingborg, Sweden. The efficacy of this GraftConnector was studied in a sheep model.

METHODS

In adult sheep, a left anterior thoracotomy under the fourth rib extended across the sternum gave good access to the left anterior descending branch (LAD) and the right internal mammary artery (RIMA). On beating hearts, the GraftConnector group had the RIMA connected to the LAD by means of the new device, while the control animals had the same anastomoses sutured with continuous 7-0 polypropylene sutures. The time for completing the anastomosis (ischemic time) was recorded and the blood flow in the RIMA was recorded with the proximal LAD open and closed, respectively. An intra-operative fluoroscopy with contrast injection directly into the graft was done. Finally the proximal LAD was ligated. The surviving animals are to be followed up.

RESULTS

Seven (46%) of the 15 animals operated on with the traditional suturing technique and seven (63%) of the 11 GraftConnector sheep survived the procedures and are to be followed up. The 11 anastomoses done with the GraftConnector were completed in 2.41+/-0.2 min, and the 14 anastomoses sutured with continuous suture were completed in 6.93+/-0.419 min (P<0.0001). The RIMA blood-flows in the two groups were comparable and are presented. All the surviving animals had open anastomoses at fluoroscopy.

CONCLUSIONS

Quick coronary artery anastomoses without suturing on beating hearts can be completed with the new GraftConnector. The GraftConnector creates reproducible anastomoses in much less time than suturing, the per-operative mortality in the GraftConnector Group was accordingly lower. Long-time follow-up of the patency in surviving animals is pending. The presented device may ultimately permit quick anastomoses endoscopically.

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.

Minimally invasive video-assisted mitral valve surgery: from Port-Access towards a totally endoscopic procedure

Right thoracotomy is an alternative to mid-sternotomy for left atrium access. The Port-Access approach is an option that reduces the skin incision and obviates rib spreading.

PATIENTS AND METHODS

From February 1997 until November 1999, 121 patients underwent mitral valve surgery through a right antero-lateral thoracotomy using the Heartport cardiopulmonary bypass (CPB) system. Mean age was 60 years (31-84). Most patients had normal ejection fractions and were in NYHA Class II or III. Seventy-five patients had valve repair (62%) and 46 (38%) had valve replacement. Pathologies were myxoid (n = 80), rheumatic (n = 30), chronic endocarditis (n = 5), annular dilatation (n = 3), sclerotic (n = 1), ingrowing myxoma (n = 1), and one closure of a paravalvular leak.

RESULTS

Two patients had conversion to sternotomy for aortic dissection (one died) with the Endo-Aortic Clamp, and two others for peripheral vascular problems. One patient died at postoperative day 1 after reoperation for failed repair, another with double valve surgery on postoperative day 4 after two revisions for bleeding. Twelve underwent revision for bleeding (10%). Three had prolonged ICU stay for respiratory insufficiency. Two late valve replacements for endocarditis occurred. Echographic control revealed residual insufficiencies (grade 1-2) in two valvular repairs. There were neither paravalvular leaks nor myocardial infarcts. There were no cerebrovascular accidents due to embolic phenomena. Mean ICU and hospital stay were 2.1 and 8.7 days, with a major difference between the first 30 patients and those who followed.

CONCLUSION

Port-Access mitral valve surgery can be a valid alternative to conventional sternotomy and seems to be an important improvement in minimally invasive cardiac surgery.

Role of off-pump coronary artery bypass grafting in patients with malignant neoplastic disease

Although the long-term benefits of conventional coronary artery bypass grafting (CABG) are obvious, postoperative morbidity and mortality and the length of recovery associated with cardiopulmonary bypass are the main concerns of cardiac surgeons and cardiologists. The aim of this study was to demonstrate the effectiveness and advantage of the off-pump CABG for patients with concomitant malignant disorders requiring myocardial revascularization. From March 1997 to February 1999, 51 patients underwent off-pump CABG. Of these, there were 9 patients who had concomitant malignant disease requiring noncardiac surgery: gastric cancer (4), urinary bladder cancer (2), cholangioma (1), lung cancer (1) and colon cancer (1). Off-pump CABG was performed through a sternotomy, left thoracotomy or subxiphoid incision. Five patients received single grafting and 4 received double. The mean operative time for the off-pump CABG was 167 min. The total amount of bleeding during the off-pump CABG was 450-890 ml. Simultaneous noncardiac operations were carried out in 5 patients. The other 4 patients underwent subsequent operations for the malignancy uneventfully. In contrast, of the 4 patients with concomitant malignant disorders who underwent standard CABG during the period before the use of off-pump CABG, 2 died without undergoing the subsequent noncardiac operation. Off-pump CABG is quite efficient and is of great advantage in patients with malignancy who require myocardial revascularization in addition to noncardiac surgery for the cancer.

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.

The Dresden approach for complete multivessel revascularization

BACKGROUND

In a prospective clinical trial, a group of patients receiving less invasive surgical procedure, including minithoracotomy in combination with cardiopulmonary bypass (group 1), was compared to a group of patients receiving conventional bypass surgery (group 2) for the treatment of coronary artery disease.

METHODS

Group 1 included 85 patients (71 men, 14 women, aged 39 to 82 years, median 61.1 +/- 9.0 years); group 2 included 53 patients (38 men, 15 women, aged 51 to 79 years, median 62.0 +/- 6.1 years).

RESULTS

There were no perioperative deaths in the whole series of patients. Time of operation was 256 +/- 43 minutes in group 1 and 150.0 +/- 53.6 minutes in group 2. Hospitalization was 6.0 +/- 1.4 days and intensive care unit stay 1 day for both groups. Back pain assessment on postoperative day 3 showed less pain in group 1. Three-month follow-up revealed ischemia in stress electrocardiogram in 2 patients (2.5%) in group 1 and in 2 patients (4.1%) in group 2. Coronary angiograms confirmed the stress-electrocardiogram findings.

CONCLUSIONS

Surgical results are equal for both techniques. Even though time of operation is longer in patients receiving less invasive procedures, intensive care unit stay and hospital stays are the same length. Early postoperative back pain is less in group 1 and combined with faster convalescence.

Minimally Invasive Coronary Artery Bypass: Experience in 114 Patients

From February 1996 to May 1998, 114 patients underwent a small (6 to 8 cm) left anterior thoracotomy for single-vessel coronary artery bypass grafting on a beating heart. There were 85 men and 29 women with a mean age of 63.1 ± 9.4 years, ranging from 36 to 84 years, and a mean preoperative ejection fraction of 53.2% ± 6.9%. The left internal mammary artery was anastomosed to the left anterior descending coronary artery under direct vision without cardiopulmonary bypass. There was no mortality. Postoperative morbidity included superficial wound infection in 3 patients. The length of the left internal thoracic artery was insufficient in two patients and the radial artery was used as an extension. Sixty-five (57%) patients underwent repeat coronary angiography (49 early, 16 late) and all grafts were patent. On intraoperative transesophageal echocardio-graphy, no segmental wall motion was seen during local coronary occlusion. Mean operative time was 1.7 ± 0.3 hours. One hundred and three patients (90%) were discharged 2 to 4 days postoperatively. The mean follow-up was 21.7 months. Minimally invasive surgery for left anterior descending coronary artery revascu-larization was considered to be a simple and effective alternative to the standard operation or angioplasty in selected patients.

Integrated left anterior small thoracotomy and angioplasty for coronary artery revascularization

BACKGROUND

The minimal access surgical technique of a left anterior small thoracotomy (LAST) for coronary artery bypass grafting is now well established. This procedure however, does not allow multivessel revascularization. We present our early experience of an integrated approach using LAST and percutaneous transluminal coronary angioplasty (PTCA), either staged or simultaneous.

METHODS

Eighteen patients (14 men and 4 women), mean age 63 (range 35-87 years) were treated. Four patients underwent simultaneous LAST and PTCA revascularization. The remaining 14 patients were first treated with the LAST procedure, followed 1-3 days later by angioplasty. Angiographic assessment was carried out before PTCA and at 6 months after.

RESULTS

The 14 patients who underwent the staged procedure all had patent left internal mammary artery/left anterior descending coronary artery grafts. Angioplasty was performed on 21 vessels (10 stented) with good early angiographic results. All patients were extubated early, mean intensive care stay was 14.7 + 9.4 hours, mean hospital stay was 5 + 1.5 days. All patients were symptom free at 18 months follow-up.

CONCLUSIONS

Staged LAST and angioplasty is a safe and effective approach suitable for patients in whom there are contraindications to the use of extracorporeal circulation. The simultaneous approach is limited by the risk of bleeding associated with the use of anticoagulation when coronary stenting is required.