Revascularization using angioplasty and minimally invasive techniques documented by thermal imaging

Interventionist videothermometry: a new model of cardiac ischemia evaluation

Background

The purpose of the present study was to evaluate, through videothermometry, the temperature variation in the hearts of rabbits, that underwent induced myocardial ischemia and reperfusion.

Results

A total of 20 female rabbits were divided into two groups: a treated group and a sham group, the treatment group underwent 5 min of cardiac arrest and reperfusion, using the inflow occlusion technique. Throughout the experiment, the animals were monitored by videothermometry, observing the thermal variations of the myocardial tissue. During the experiment, at different times, blood gas tests and tests to evaluate the lactate concentrations were performed. At the end of the experiment, each heart was submitted to histopathological evaluation. In the treated group, there was a reduction in temperature of the myocardial tissue during the circulatory arrest compared to the sham group. Additionally, a colder area next to the caudal vena cava ostium and the right atrium was observed. Notably, despite the 5 min of cardiac arrest in the treated group, both the lactate and bicarbonate levels were maintained without significant variation. However, there was an increase in PaCO2 and pH reduction, featuring respiratory acidosis. In relation to the histopathological study, the presence of hydropic degeneration in the myocardium of animals in the treated group was observed.

Conclusions

Based on these results, the videothermometry was efficient in identifying the range of myocardial tissue temperature, suggesting that the first areas to suffer due to cardiac arrest were the caudal vena cava ostium and the right atrium. However, in regard to the angiographic coronary thermography, the study was not feasible due to the small size of the coronary. There was no variation between the groups regarding the presence of myocardial infarction, myocardial congestion, myocardial edema and myocardial hemorrhage.

A Stereo Thermographic System for Intra-operative Surgery

A stereo far-infrared (FIR) system based on the trigonometric parallax is presented in this paper for locating the distal arterial tree from the coronary artery bypass graft. The system can obtain the wide angle-of-view range information in the near distance by changing the optical path of one fixed uncooled FIR camera. Meanwhile, the speed of pixel movement on the FIR imaging plane is discussed for avoiding the problem on the imaging blur because the images are taken in sequence from a scanning mirror for the real-time monitor of the operation. Besides, the view range is also considered under the different system parameter conditions. After the structure parameters are simulated for evaluating the performance, the optimum system can be designed. This thermal imaging technique is inexpensive, noninvasive and feasible for intra-operative surgery.

Infrared thermography: a rapid, portable, and accurate technique to detect experimental pneumothorax

RATIONALE AND OBJECTIVE

Pneumothorax (Ptx) is a life-threatening complication that can result from trauma, mechanical ventilation, and invasive procedures. Infrared thermography (IRT), a compact and portable technology, has become highly sensitive. We hypothesized that IRT could detect Ptx by identifying associated changes in skin temperature.

MATERIALS AND METHODS

Bilateral nonpenetrating chest incisions or needle punctures were performed in 21 anesthetized rats. Rats were then randomized to no, bilateral, left, or right Ptx by either open (n = 16) or closed percutaneous (n = 5) puncture through selected pleurae. Real-time thermographic images and surface temperature data were acquired with a noncooled infrared camera.

RESULTS

In all cases, blinded observers correctly identified each Ptx with real-time grayscale image analysis. When compared to either the ipsilateral baseline or an abdominal reference, experimental Ptx produced a significantly greater decrease in surface temperature when compared to non-Ptx control.

CONCLUSIONS

These results demonstrate that portable infrared imaging can rapidly and accurately detect changes in thoracic surface temperature associated with experimental pneumothorax.

Novadaq SPY: intraoperative quality assessment in off-pump coronary artery bypass grafting

OBJECTIVES

Off-pump coronary artery bypass grafting may decrease operative morbidity when compared to on-pump bypass grafting; however, it is technically demanding and thus quality control is essential. This study assesses the clinical feasibility of a new, indocyanine green (ICG)-based imaging system (SPY; Novadaq Technologies; Toronto, ON, Canada) to monitor the quality of anastomoses and grafts in off-pump revascularization.

SETTING

Thirty-eight consecutive patients undergoing nonemergent coronary artery bypass grafting without the use of extracorporeal circulation at two Swiss cardiac surgery clinics were included. On completion of bypass grafts, the quality of the grafts was assessed using the ICG-based imaging system. The imaging device comprises an 806-nm laser light source that is used to cause ICG to fluoresce and a near infrared-sensitive charged couple device videocamera that is used to capture the fluorescence images. ICG was administered through the central venous line, and images were acquired during the first pass of the ICG through the field of view. Graft flow (qualitative) and the quality of the grafts and anastomoses were assessed intraoperatively.

RESULTS

Between March 2002 and September 2002, a total of 38 patients (26 men and 12 women; mean +/- SD age, 64.6 +/- 10.5 years; body mass index, 27.1 +/- 2.9) underwent surgery and imaging at two institutions. One hundred seven of 124 grafts (45 arteries and 62 veins) were analyzed. Seventeen grafts could not be assessed due to difficulties in positioning. The imaging system was easy to handle, and no adverse reactions to ICG were observed. Four of the 107 grafts imaged required revision (three anastomotic constrictions and one graft dissection). Each imaging sequence required approximately 1.25 to 2.5 mg of ICG. The images were equivalent to angiography without the need for radiographs and catheter insertion. In addition, the course of coronaries that would otherwise be difficult to locate in obese patients could be detected using the imaging system. Biochemical and ECG data demonstrated an absence of intraoperative or postoperative myocardial damage, and no liver enzyme elevation or renal dysfunction.

CONCLUSIONS

This study supports the clinical utility of a ICG-based imaging system for the assessment of the quality of bypass grafts, which appears to be safe and simple to use.

Opposite trends in coronary artery and valve surgery in a large multisurgeon practice, 1979–1999

BACKGROUND

Trends in coronary artery bypass (CAB) and valve operations (VO) may help predict the future of cardiac surgery in the context of changing case mix, shifting paradigms, emerging technology, and population demographics.

METHODS

We retrospectively reviewed all 30,319 adult CAB and VO in our group from 1979 to 1999 according to specific procedures.

RESULTS

Coronary artery bypass volumes peaked in 1996 at 1,895 cases, declining 15.3% to 1,605 cases in 1999 with a decrease in risk profile and percent reoperations and an increase in mean age and percent octogenarians, prior percutaneous coronary interventions (PCI), left internal mammary artery (LIMA) graft usage, off-pump technology usage, and hospital mortality of reoperations. Right internal mammary grafts were employed infrequently and radial artery grafts transiently. Overall VO volumes continued to increase 24.0% since 1996, from 470 to 583 cases with a decreased risk profile, increased mean age, and percent octogenarians and prior PCI. The percentage of mechanical valve implants decreased, while the percentage of various tissue solutions for valve disease increased. Limited access incisions and port-access were employed transiently with CAB and VO.

CONCLUSIONS

Coronary artery bypass volumes are decreasing, with an increasing percentage of LIMA grafts and off-pump cases. Valve operation volumes are steadily increasing, with a decreasing percentage of mechanical valve implants, in favor of various tissue solutions.

Coronary hybrid revascularization from January 1997 to January 2001: a clinical follow-up

BACKGROUND

Hybrid revascularization (HyR), combining minimally invasive left internal mammary artery (LIMA) bypass grafting to the left anterior descending coronary artery (LAD) and catheter interventional treatment of the remaining coronary lesions, avoids the disadvantages associated with cardiopulmonary bypass (CPB). We investigated the clinical follow-up of 57 patients with multivessel disease undergoing this procedure in the last 4 years.

METHODS

Between January 1997 and January 2001, 57 consecutive patients (41 men and 16 women, aged 65.7 +/- 7.9 years) with coronary artery disease (two-vessel, n = 34; three-vessel, n = 23) were treated with off-pump LIMA-to-LAD bypass combined with balloon angioplasty and stenting of the remaining significantly obstructed (> 50%) coronary vessels. Clinical follow-up data included a early postoperative and a 6-month control angiography and a patient interview in January 2001.

RESULTS

All patients underwent LIMA-to-LAD bypass-grafting and balloon angioplasty in 72 coronary lesions without procedural-related complications. However, one early LIMA bypass occlusion was documented during coronary angiography. Postoperatively no deterioration of preexistent organ dysfunction was observed in any patient. The mean follow-up was 100.7 +/- 37.9 weeks in 55 of 57 patients (97%). Control angiography 6 months after HyR (n = 34) revealed a patent LIMA bypass in 33 patients and 8 in-stent restenoses (> 50%) in the coronary arteries that were treated interventionally by re-PTCA (n = 6) or by conventional CABG (n = 1). In 1 patient medical treatment resulted in significant reduction of angina so no further intervention was considered necessary. After HyR 1 patient died 18 months later of an intracerebral hemorrhage. All other patients are alive and doing well.

CONCLUSIONS

Our results indicate that in selected patients with multivessel disease including left main stem stenosis HyR is an effective and secure procedure with excellent early and good midterm results. Especially elderly patients with severe concomitant diseases appear to benefit from this approach by avoiding CPB.

Hybrid revascularization feasibility in minimally invasive direct coronary artery bypass grafting combined with percutaneous transluminal coronary angioplasty in patients with acute coronary syndrome and multivessel disease

OBJECTIVES

We reviewed early and midterm outcome of 11 multivessel-disease acute coronary syndrome patients treated by hybrid revascularization, i.e., initial coronary angioplasty followed by minimally invasive direct coronary artery bypass grafting. We evaluated procedural efficacy and applicability.

METHODS

Beginning in August 1997, hybrid revascularization was conducted in 11 multivessel-disease acute coronary syndrome patients--9 men and 2 women with a mean age of 70.3 +/- 9.3 years. Occlusion or stenosis of the target coronary artery was treated by interventional cardiologic techniques and minimally invasive direct coronary artery bypass grafting, and the early and midterm outcome evaluated. Coronary angiography was conducted in all cases at 2 weeks, 6 months, 1 and 3 years postoperatively to evaluate anastomosis and restenosis in treated coronary vessels.

RESULTS

Initial intervention succeeded in patients with minimal residual stenosis. Subsequent minimally invasive direct coronary artery bypass grafting involved no complications. Coronary angiography early postoperatively, 6 months, 1 and 3 years later showed grafts patent without stenosis. Percutaneous transluminal coronary angioplasty was reconducted on restenotic lesions in 3 patients, 1 of whom required 3 procedures.

CONCLUSIONS

Hybrid revascularization appears safe and effective in coronary revascularization, at least over the short term. Several patients underwent angioplasty for restenosis within 3 years after initial procedure. Overall acceptance of this hybrid method depends on long-term functional success of the 2 procedures. Its major limitation is restenosis of angioplasty sites and the need for repeat procedures.

The coronary artery bypass conduit: II. Assessment of the quality of the distal anastomosis

The outcome of coronary artery bypass grafting procedures is highly dependent on the technical adequacy of the distal anastomosis. Various methodologies, including flow measurement and imaging techniques, have been used by the cardiothoracic surgeon to assess the adequacy of the distal anastomosis. The limitations of these techniques outweigh their advantages and limit their widespread clinical applicability. Recent improvements in the technique for online measurement of regional myocardial pH provide a promising new metabolic approach to assessing the adequacy of the distal anastomosis in cardiac surgery.

Thermal imaging in the detection of bowel ischemia

PURPOSE

The aim of this study was to introduce thermal imaging in the intraoperative detection of bowel ischemia by comparing thermal imaging with conventional techniques in detecting acutely ischemic bowel, using histologic evidence for intestinal necrosis as the standard.

METHODS

A prospective study was performed using a porcine model. Laparotomy was performed on four pigs under general anesthesia. A 25-cm segment of mid jejunum was tagged with proximal and distal sutures, and its mesentery was ligated and divided. Thermal imaging, visual inspection, Doppler ultrasound, and fluorescence with Wood's lamp after fluorescein were used to estimate the extent of bowel ischemia five minutes after ligation of the mesentery. Measurements were taken in reference to both the proximal and distal tags to obtain two data points per animal for each method. After two hours of warm ischemia, the jejunum was harvested and sectioned longitudinally. Comparisons were made between the estimated region of necrosis for each method and microscopic evidence of necrosis.

RESULTS

Visual inspection was the only method unable to detect a difference between vascularized and devascularized bowel for each of the eight data points. Fluorescein dye missed 3 cm of ischemic bowel. Doppler ultrasound and thermal imaging were 100 percent sensitive for necrotic bowel, with thermal imaging overestimating necrosis to a greater extent than Doppler ultrasound. The positive predictive value of fluorescein dye, Doppler ultrasound, and thermal imaging for determining nonviable bowel was 91.8, 80.8, and 69.5 percent, respectively.

CONCLUSIONS

Thermal imaging has the potential to be a useful adjunct in the intraoperative determination of bowel ischemia. Further studies are indicated to study this technique.

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.

[Hybrid revascularization]

OBJECTIVE

To evaluate our initial experience in the combination of two less invasive procedures for myocardial revascularization, coronary artery bypass grafting without cardiopulmonary bypass and immediate posterior angioplasty, on untreated lesions (hybrid revascularization) as an alternative treatment to conventional surgery in selected patients.

MATERIAL AND METHODS

From october 1996 to September 1998, 19 patients received hybrid revascularization. The mean age was 64 (47-76). Two patients underwent urgent surgery. Two patients had left main coronary disease, and 9 three-vessel disease. In general, we considered this procedure for patients with high-risk factors for cardiopulmonary bypass and two or more vessel disease. The internal mammary artery was connected to the left anterior descending artery in all 19 patients. All patients were moved to the hemodynamic ward immediately after surgery in 7 cases and before 48 h in the rest, 24 angioplasties were performed. A mean of 2.6 vessels per patient were revascularized and revascularization was complete in 15 patients (79%).

RESULTS

One patient had perioperative myocardial infarction. There was no hospital mortality. Length of stay in the intensive care unit was 44 h (IQR = 49) and global postoperative stay was 8 days (IQR = 3.5). In the postoperative angiographic study, before the angioplasty, 95% of mammary arteries (CI 95% 74-100%) and 100% of saphenous grafts (CI 95% 59-100%) were patent.

CONCLUSIONS

Combined revascularization allows almost complete revascularization, avoiding complications of cardiopulmonary bypass and minimizing surgical aggression. At the same time, it secures the graft of internal mammary artery to left anterior descending artery.

[Minimally invasive cardiac surgery: surgical techniques and anesthetic problems]

OBJECTIVE

To review current data on minimally invasive cardiac surgery.

DATA SOURCES

Search through the Medline data base of French or English articles.

DATA EXTRACTION

The articles were analysed to make a synthesis of the various techniques with their main indications and contra-indications.

DATA SYNTHESIS

Minimally invasive cardiac surgery includes various surgical procedures. The usual techniques are described, their major benefits and drawbacks are discussed. The main goals of anaesthetic management are preservation of ventricular function and systemic perfusion, detection and treatment of myocardial ischaemia, prevention of hypothermia in case of coronary artery bypass grafting on the beating heart via sternotomy, intermittent selective ventilation of the collapsed lung using CPAP in case of limited thoracotomy. Expertise in transoesophageal echocardiography is essential for insertion and checking the accurate positioning of the various catheters of the endovascular CPB Heartport system (pulmonary vent, endosinus catheter, venous cannula, endoaortic clamp) allowing coronary artery bypass grafting and mitral valve surgery through limited thoracotomy and finally, detection of retained intracardiac air and assessment of complete clearing of cardiac cavities after mitral valve surgery through limited thoracotomy and aortic valve surgery via ministernotomy. Short-acting anaesthetic agents allow rapid recovery from anaesthesia, early extubation and discharge to the surgical ward within 24 h, whereas overall time spent in the operating room is often longer than with conventional cardiac surgery.

Management of Cardiopulmonary Bypass during Minimally Invasive Cardiac Surgery

From December 1996 to December 1997, 58 patients underwent minimally invasive cardiac surgery in our institute. The operations comprised 10 for atrial septal defect, 26 for ventricular septal defect, 15 for mitral stenosis and insufficiency, 4 for aortic valve insufficiency, 2 for left atrial myxoma, and 1 for right ventricular myxoma. There were 21 men and 37 women with a mean age of 20 years (range, 5 to 46 years) and a mean weight of 35 kg (range, 15 to 68 kg). To establish cardiopulmonary bypass, femorofemoral and superior vena caval cannulation or femoral artery and two-stage cannulation was used. Normothermia with a beating heart or moderate hypothermia with aortic cross-clamping during cardiopulmonary bypass were employed. All patients resumed sinus rhythm spontaneously, except for one who was easily defibrillated. There were no deaths or neurologic complications and no problems with the cannulation sites. We concluded that these techniques of cardiopulmonary bypass were feasible and safe.

Intraoperative considerations during minimal-access cardiac surgery

The range of minimal-access cardiac surgery approaches has many implications in intraoperative management. A modified anesthetic regimen is required to deal with the type of surgical exposure, hemodynamic instability, whether cardiopulmonary bypass is used, and early extubation. Intraoperative considerations include hemodynamic monitoring, one-lung ventilation, pharmacological stabilization of the myocardium, pacing, hypothermia, bleeding, and rapid emergence with a minimum of postoperative mechanical ventilation. As a result, anesthetic methods and intraoperative management were modified to meet these specific needs of minimally invasive cardiac procedures.

Routine intraoperative angiography improves the early patency of coronary grafts performed on the beating heart

OBJECTIVES

The techniques of performing coronary revascularization without cardiopulmonary bypass are rapidly evolving. However, concern remains regarding the accuracy of coronary artery anastomoses performed on the beating heart. This report reviews the use of intraoperative angiography in the critical appraisal of "off-pump" coronary artery bypass graft (CABG) surgery.

PATIENTS

Intraoperative angiography was performed in 24 consecutive patients undergoing CABG surgery without cardiopulmonary bypass. In all, 24 left internal mammary artery (LIMA) grafts and 18 saphenous vein bypass grafts were assessed for patency, anastomosis quality, distal and proximal runoff, and correct placement.

RESULTS

All of the saphenous vein-to-coronary artery anastomoses were widely patent, although two patients (8%) required revision of their LIMA grafts on the basis of angiographic findings.

CONCLUSION

Intraoperative angiography permits the surgeon to immediately appraise the CABG and to revise, if necessary, any graft abnormality, thus potentially eliminating the need for early repeated surgery. The practice of routine intraoperative angiography is likely to improve the outcome of CABG surgery on the beating heart.

Assessing flow during minimally invasive coronary artery bypass: an Allen's test equivalent

The use of a provocative test to elicit selective regional myocardial dysfunction (detected with intraoperative TEE) as a method to infer adequacy of regional myocardial perfusion following MIDCAB is described. We liken the similarity of this technique to the originally described "Allens test" for determination of collateral blood flow adequacy.

Anastomosis to the wrong vessel during off-pump bypass surgery via mini-thoracotomy

Recently, minimally invasive coronary artery bypass graft operation has been established as a new treatment strategy for cardiac surgeons. We report on a patient who underwent off-pump coronary artery bypass graft operation through a mini-thoracotomy to the wrong coronary artery (first diagonal) with consecutive successful percutaneous transluminal coronary angioplasty of the vessel involved (left anterior descending coronary artery) to demonstrate a special risk that is associated with this kind of operation.

Minimally invasive direct coronary bypass versus cardiopulmonary technique: angiographic comparison

BACKGROUND

Studies comparing minimally invasive direct coronary artery bypass grafting (MIDCABG) with techniques using cardiopulmonary bypass (CPB) are needed.

METHODS

Sixteen patients underwent single-vessel left internal thoracic artery-left anterior descending (LITA-LAD) MIDCABG through a left anterior thoracotomy, and 10 underwent multivessel bypass grafting that included a LITA-LAD, using CPB. Intraoperative completion angiography was performed on all LITA-LAD bypasses, and graded. One point each was given for: anastomotic patency, pedicle patency, intercostal obliteration, proper placement into the correct native coronary artery, and Thrombosis In Myocardial Ischemia grade III flow.

RESULTS

There were no intraoperative deaths or morbidities. LITA takedown averaged 49 +/- 18.6 minutes for MIDCABG and 16 +/- 2.0 minutes for CPB CABG (p < 0.05). LITA length did not differ between groups (15.3 +/- 1.2 cm for MIDCABG, 14.3 +/- 1.08 cm for CPB CABG). Ischemic arrest time was significantly less for the CPB group (13.3 +/- 8.3 minutes versus 24.5 +/- 9.6 minutes; p < 0.05). Average grade for MIDCABG LITA-LAD was 4.06 +/- 0.98 points versus 4.77 +/- 0.98 points for CPB LITA-LAD bypass (p = not significant).

CONCLUSIONS

Intraoperative completion angiography is feasible and, when combined with a grading system, may facilitate the comparison of MIDCABG with standard techniques.

Seven-year follow-up of coronary artery bypasses performed with and without cardiopulmonary bypass

BACKGROUND

There has been resurgent interest in coronary revascularization performed on the beating heart. Heretofore, there has been no long-term comparison of this technique to traditional coronary artery bypass with cardioplegia.

OBJECTIVE

The purpose of this study was to provide a comparison of long-term survival and intervention-free outcome between patient groups subjected to coronary bypass accomplished with or without the use of cardiopulmonary bypass.

METHOD

From June 1989 to July 1990, all patients treated for coronary revascularization by three surgeons were considered for coronary revascularization with the heart beating: 107 patients underwent coronary bypass on the beating heart, and 112 patients underwent revascularization with the aid of bypass with cardioplegia. Mean ages (65 +/- 10 years) and risk factors were identical. Patients operated on with the heart beating had 2.4 +/- 0.9 grafts versus 3.2 +/- 1.1 grafts for patients having cardiopulmonary bypass with cardioplegia.

RESULTS

At 7-year follow-up, 86 of 107 (80%) patients operated on with the heart beating were alive versus 88 of 112 (79%) patients in whom cardiopulmonary bypass with cardioplegia was used. Cardiac deaths occurred in 13 of 107 (12%) patients in the former group versus 10 of 112 (9%) patients in the latter group. However, 32 of 107 patients operated on with the heart beating (30%) needed catheterization for their symptoms versus 18 of 112 (16%) patients in the bypass with cardioplegia group (p = 0.01). This results in 21 of 107 (20%) patients in the beating heart group needing angioplasty or a second coronary bypass versus only 8 of 112 (7%) patients in the bypass with cardioplegia group. No patient in the bypass with cardioplegia group required reoperation. Most of the reinterventions for the beating heart group were percutaneous transluminal coronary angioplasty (15 of 21 [71%] patients).

CONCLUSION

Despite one less graft per patient, survival and cardiac death rates were similar for the two groups. However, twice as many patients in the beating heart group required recatheterization (30% versus 16%), and 20% needed a second intervention. Only 7% of the bypass with cardioplegia group required reintervention. Limited revascularization of the beating heart provides long-term results comparable to full revascularization with cardiopulmonary bypass, but at the cost of a threefold increase in reinterventions.

Cardiac surgery without the use of cardiopulmonary bypass: the challenges

Minimally invasive bypass grafting of the internal thoracic artery to the left anterior descending artery has become routine in many institutions. Currently, indications for single vessel revascularization are expanding to those patients not suitable to be operated upon using extracorporeal circulation, but surgeons remain rather reluctant when multivessel disease is concerned. In such cases, the 'hybrid technique', i.e. single vessel bypass grafting followed by percutaneous transluminal coronary angioplasty at a different site, seems to be a more appropriate alternative. Despite the merits of minimally invasive surgery, the majority of surgeons do not believe that it is possible to achieve the same quality of anastomosis on a beating heart as on an arrested heart.

Intraoperative angiography in minimally invasive direct coronary artery bypass grafting

Intraoperative angiography in minimally invasive direct coronary artery bypass grafting without cardiopulmonary bypass and in hybrid procedures is reported. Twelve procedures were performed in a specially designed surgical-radiologic suite with a cross-disciplinary organization. In 2 patients the anastomosis was successfully revised on the basis of angiographic findings. In 4 of the 12 patients anastomosis of the left internal mammary artery to the left anterior descending coronary artery performed as a minimally invasive direct coronary artery bypass grafting procedure was combined with percutaneous transluminal coronary angioplasty of lesions in other coronary vessels in the same session. Intraoperative angiography allows a reliable diagnosis of an anastomosis or graft failure and prompt and reliable correction, and it allows the combination of minimally invasive direct coronary artery bypass grafting and angioplasty in one session.

Intraoperative angiography during minimally invasive direct coronary artery bypass operations

BACKGROUND

The technical demands of beating heart operations raise concerns about anastomotic patency. This feasibility study tested the usefulness of intraoperative angiography during minimally invasive direct coronary artery bypass grafting (MIDCABG).

METHODS

Ten patients underwent intraoperative angiography of the internal thoracic artery (ITA) after MIDCABG. Minimally invasive direct coronary artery bypass grafting was performed on a beating heart through the fourth or fifth intercostal space. Angiography was performed through the right or left femoral artery with a 7F introducer system placed before the operation. Views were obtained in the right and left anterior oblique and straight anterior projections.

RESULTS

There were no deaths or intraoperative morbidities related to MIDCABG or angiography. Seven patients demonstrated widely patent MIDCABG anastomoses with obliteration of all intercostals, widely patent ITA pedicles, good distal runoff, and placement of the ITA into the proper native coronary artery. Two patients had revisions of their ITA pedicles, which on repeated angiography showed correction. One patient's procedure was converted to a sternotomy because of poor distal runoff and haziness at the level of the MIDCABG anastomosis.

CONCLUSIONS

This feasibility study demonstrates the utility of intraoperative ITA angiography in identifying problems after MIDCABG. Intraoperative angiography may facilitate MIDCABG by documenting proper placement of conduits, obliteration of intercostal vessels, and patency of the MIDCABG anastomosis and ITA pedicle.

Thermal coronary angiography for intraoperative testing of coronary patency in congenital heart defects

Intraoperative thermal coronary angiography was successfully applied in 9 patients who underwent operative correction of congenital heart defects: arterial switch operation for transposition of the great arteries (n = 5), Ross operation for valvar aortic stenosis with regurgitation (n = 3), and aortic implantation of the left coronary artery for anomalous connection of the left coronary artery to the pulmonary artery (n = 1). Intraoperative thermal coronary angiography allows early detection and surgical correction of coronary ostial obstruction.

The MIDCAB experience: a current look at evolving surgical and anesthetic approaches

This article reviews and updates the recent modifications in patient selection and revisions in the anesthetic approach to MIDCAB surgery. It outlines the changing surgical selection criteria, current ways to assess graft patency, and evolving anesthetic management. A promising new advancement in coronary artery bypass, the minimally invasive technique has received varying reviews and undergoes careful evaluation. Increasing surgical experience, immediate postoperative assessment of graft patency, and improvement in surgical instruments are expected to improve patient outcome. A stratification of MIDCAB patients into status I and status II patients will aid in future evaluation of surgical and anesthetic outcome. Communication of newly developed techniques to those caring for cardiovascular patients is imperative.

A survey on minimally invasive coronary artery bypass grafting

BACKGROUND

There is increasing interest in performing minimally invasive coronary artery bypass grafting. To evaluate the current level of acceptance and utility of this procedure a survey of 162 cardiothoracic surgeons was conducted.

RESULTS

Currently only 16% of surveyed surgeons performed more than 10 minimally invasive coronary artery bypass grafting procedures. Most were less than 55 years old and in private practice. The majority predicted that it will be indicated in less than 25% of coronary artery bypass grafting cases and considered minimally invasive coronary artery bypass grafting a modification of existing techniques rather than investigational. Most believed exposure and stabilization of the coronary arteries on the beating heart to be the most challenging part and expressed concern with quality of the anastomosis.

CONCLUSIONS

We conclude that minimally invasive coronary artery bypass grafting is rapidly gaining acceptance in younger surgeons as techniques are improved. Despite concerns with adequacy of anastomosis the procedure is not considered investigational and follow-up is not rigorous.