Utility of transesophageal echocardiography during port-access minimally invasive cardiac surgery

The evolving role of the modern perfusionist: insights from transesophageal echocardiography

Transesophageal echocardiography is a relatively non-invasive, mobile, safe imaging technique that is ideal for providing real-time information on cardiac anatomy and function during heart surgery. The technology has evolved from two-dimensional to real-time three-dimensional imaging during cardiac procedures, which has significantly benefited preoperative planning, intraoperative guidance, evaluation, and postoperative follow-up. Transesophageal echocardiography may serve the clinical perfusionist by providing imaging guidance for identifying potential problems before cardiopulmonary bypass, guiding the proper placement of cannulas, monitoring cardiac performance on cardiopulmonary bypass, and providing useful feedback during weaning from cardiopulmonary bypass. Although the perfusionist should be able to understand all echocardiographic images and measurements in depth, perfusion-related echocardiographic information can or should be used to optimize the clinical practice of the modern perfusionist. Vice versa, whenever the perfusionist suspects a problem, the surgical team including the sonographer should verify this "clinical treat" by echocardiography whenever possible.

Modified Port-Access Technique for the Treatment of Aortic Dissection after Previous Cardiac Surgery

One of the most challenging conditions to manage after previous cardiac surgery is chronic dissection of the ascending aorta. We operated on a 54-year-old man who had aortic dissection in addition to large aortic dimensions very close to the sternum, severe aortic regurgitation, and a false lumen in the descending aorta. We used a combination of perfusion and myocardial protection techniques, arising from port-access technology, that enabled antegrade flow into the aorta, endoclamping of the ascending aorta, the administration of cardioplegic solution before opening the sternum, and left ventricular venting to prevent ventricular distention. Our technique resulted in minimal blood loss, shorter circulatory-arrest and operative times, the ability to operate on a decompressed heart and descending aorta, good myocardial protection, and easier and safer access to the heart. Three years postoperatively, our patient was doing well. Other patients might benefit from this approach; however, the surgeon must ensure that an aortic segment is suitable for endoclamping.

Effects of postural change on transesophageal echocardiography views and parameters in healthy dogs

The purpose of the present study is to investigate the effect of postural change on transesophageal echocardiography (TEE) views and parameters of interest anesthesia monitoring in healthy dogs. Twelve Beagle dogs were anesthetized and randomly positioned in one of four postures: right lateral-recumbency, left lateral-recumbency, supine position and prone position. After examinations in one posture, the same examination was demonstrated in another posture and repeated in all postures. In each posture, several standard TEE views were demonstrated: longitudinal cranial-esophageal aorta long-axis-view, transverse middle-esophageal mitral valve long-axis-view and transgastric middle short-axis-view. Additionally, echocardiographic parameters were attempted to measure, and direct blood pressure monitoring was performed in each view. As a result, oriented views, except for transgastric middle short-axis-view, could be obtained in all postures. Stroke volume and peak early diastolic velocity of mitral inflow were lower in supine position compared with those in right and left lateral-recumbency. Heart rate (HR) and systemic vascular resistance were higher in supine position compared with those in right and left lateral-recumbency. Left ventricular pre-ejection period/left ventricular ejection time corrected and uncorrected by HR were higher in supine position compared with those in right and left lateral-recumbency. In conclusion, longitudinal cranial-esophageal aorta long-axis-view and transverse middle-esophageal mitral valve long-axis-view provide useful information of interest anesthesia monitoring, because of their views enable to certainly obtain TEE parameters in various postures. Furthermore, TEE parameters allow to detect the changes of preload, afterload and HR that occur in supine position dogs.

Ascending Aortic Endoballoon Occlusion Feasible despite Moderately Enlarged Aorta to Facilitate Robotic Mitral Valve Surgery

Objective

Aortic occlusion with an endoballoon is a well-established technique to facilitate robotic and minimally invasive mitral valve surgery. Use of the endoballoon has several relative contraindications including ascending aortic dilatation greater than 38 mm in size. We sought to review our experience using the endoballoon in cases of totally endoscopic mitral valve surgery with aortic diameters greater than 38 mm.

Methods

A retrospective review of our single-site database was conducted to identify patients undergoing totally endoscopic mitral valve surgery by a single surgeon using an endoballoon and who had ascending aortic dilation. We defined aortic dilation as greater than 38 mm. Computed tomography was done preoperatively on all patients to evaluate the aortic anatomy as well as iliofemoral access vessels. Femoral artery cannulation was done in a standardized fashion to advance and position the endoballoon, to occlude the ascending aorta, and to deliver cardioplegia.

Results

From October 2011 through June 2015,196 patients underwent totally endoscopic mitral valve surgery using an endoballoon at our institution. Twenty-two patients (11.2%) had ascending aortic diameters greater than 38 mm (range, 38.1–16.6 mm; mean, 40.5 ± 2.5 mm). In these cases, there were no instances of aortic dissection or other injury due to balloon rupture, balloon migration, device movement leading to loss of occlusion, or inability to complete planned surgery due to occlusion failure.

Conclusions

Our experience suggests that it is possible to successfully use endoaortic balloon occlusion in patients with ascending aortic dilation with proper preoperative imaging and planning.

Intraoperative Echocardiography: Support for Decision Making in Cardiac Surgery

Intraoperative echocardiography (including transesophageal echocardiography, epiaortic ultrasound and epicardial echocardiography) is commonly performed in North American hospitals during cardiac anesthesia. Several authors have reported on the positive impact of intraoperative echocardiography on patients’ outcomes. Transesophageal echocardiography is useful in identifying anatomic and functional abnormalities either before or after cardiopulmonary bypass and helps to make decisions in the care of high-risk and unstable patients. In minimally invasive and robotically assisted surgery, transesophageal echocardiography is essential in order to guide cannulation of venous and arterial vessels for cardiopulmonary bypass and in providing immediate assessment of the quality of the performed repair. Intraoperative echocardiography can also detect complications associated with the performed procedure and can be an excellent hemodynamic monitor in unstable patients. In this paper different scenarios where intraoperative echocardiography is useful are reviewed, some clinical cases are shown to illustrate, and a review of related literature is reported.

Evaluation of different types of inferior vena cava cannulae placement by transesophageal echocardiography and its impact on hepatic dysfunction

BACKGROUND

Postoperative hepatic dysfunction may occur in an otherwise uncomplicated open heart surgery. One of the reasons is malpositioning of the inferior vena cava (IVC) cannula in the hepatic vein (HV) or beyond. A straight cannula is considered more likely to be malpositioned compared to the angled cannula and a malpositioned cannula can lead to hepatic dysfunction.

METHODS

In this prospective study, forty adult patients undergoing atrial septal defect repair were randomized into two groups as: straight cannula group (n=20) and angled cannula group (n=20). The cannula position was assessed by transesophageal echocardiography (TEE) (hepatic vein view). Alanine aminotransferase levels (ALT) and bilirubin levels were measured immediately, at 6 hours and on day 1, day 2 and day 7 after surgery as a marker of hepatic injury.

RESULTS

TEE localization of the IVC cannula was achieved in all patients except one. Visualization was good in 85% of patients. A cannula in the HV or beyond the HV in the IVC was considered malpositioned. The number of cases of cannula malposition was 10 (50%) and 4 (20%) in the straight and angled cannula groups, respectively. The pattern of change in serum bilirubin and liver enzymes levels in the postoperative period was similar in both the groups (p>0.05). The mean distance between the right atrium (RA) - inferior vena cava (IVC) junction to the hepatic vein was 1.94±0.56 cm and the mean diameters of the IVC and HV were 1.95±0.5 and 1.31±0.33 cm, respectively.

CONCLUSION

TEE can be used to monitor IVC cannula position. A higher frequency of cannula malposition was observed with the straight cannula compared to the angled cannula, but was not found to be associated with hepatic dysfunction.

The Role of Computed Tomography Angiography in Patients Undergoing Evaluation for Minimally Invasive Cardiac Surgery: An Early Program Experience

Objective

An increasing number of patients are undergoing surgical procedures using minimally invasive cardiac surgery (MICS). These techniques use conventional or retrograde arterial perfusion with direct aortic cross-clamping or endoballoon occlusion. Precise knowledge of the arterial tree is required to avoid complications and to plan for the operation. We examined the role of computed tomography angiography (CTA) in evaluating patients for MICS.

Methods

We reviewed all consecutive candidates undergoing CTA during preoperative evaluation for MICS aortic, mitral, tricuspid, Maze, atrial septal defect, or myxoma procedures between February 2008 and May 2010. The CTA findings of patients excluded from MICS were compared against those successfully undergoing MICS.

Results

One hundred eleven MICS candidates underwent preoperative CTA. Thirty-five (32%) had single or multiple CTA findings precluding MICS and underwent sternotomy. Seventy-six (68%) had favorable CTA findings and underwent MICS. The MICS group had a mean age of 62 years, with 29 women (39%); the non-MICS group had a mean age of 68 years, with 17 women (48%). Of the patients excluded from MICS, two (6%) had diminished or absent lower extremity pulses. All MICS patients (except for aortic) had successful use of the endoballoon. There were no perfusion or peripheral vascular complications. There was one stroke, one lymphocele, and one death (chronic obstructive pulmonary disease exacerbation).

Conclusions

Computed tomography angiography is of fundamental importance in evaluating patients for MICS. It can identify calcified regions that make for threatening catheter passage with subsequent retrograde arterial perfusion. Abnormalities of the arterial tree are identified. The use of CTA-guided patient selection can thus avoid major perioperative complications.

Outcomes of peripheral perfusion with balloon aortic clamping for totally endoscopic robotic mitral valve repair

OBJECTIVE

Although the technique of totally endoscopic robotic mitral valve repair (TERMR) has been well described, few reports have examined the results of peripheral perfusion with balloon clamping. We analyzed the outcomes of TERMR performed using this strategy.

METHODS

A total of 108 consecutive patients underwent TERMR by a 2-surgeon team. The preoperative evaluation included chest computed tomography and abdominal and pelvis computed tomography. Additional procedures included appendage exclusion in 96, patent foramen ovale closure in 29, cryoablation in 16, tricuspid valve repair in 2, and septal myectomy in 2. The mean patient age was 59 years (range, 21-86). Central venous drainage was obtained with a long cannula. Arterial return was achieved with femoral cannulation, when possible. An endoballoon catheter was placed through the femoral artery. Transesophageal echocardiography was used to position all catheters.

RESULTS

Femoral artery perfusion was possible in 103 of 108 patients (95.3%). The subclavian artery was used in 5 patients (4.6%) with contraindications to retrograde perfusion. An endoballoon clamp was placed by way of the femoral artery. In 105 of 108 patients (97.2%), endoaortic occlusion was successfully used; the mean crossclamp time was 87.4 minutes. The coronary sinus cardioplegia catheter was placed successfully in 81 of the 108 patients (75%). Postoperatively, no or mild inotropic support was needed in 94 (87%) and moderate support in 14 (13.0%). Of the 108 patients, 55 (50.9%) were extubated in the operating room. No hospital mortality, aortic injury, vascular complications, or wound infections occurred. Complications included 2 strokes (no residual deficit) (1.8%) and atrial fibrillation in 18 (16.7%). The median hospital stay was 4 days. Eighty patients (74.1%) were discharged by postoperative day 5.

CONCLUSIONS

A preoperative image-guided perfusion strategy and aortic balloon clamping permit routine TERMR with excellent myocardial preservation and minimal complications.

Transesophageal echocardiography: a complementary view of the heart

Transesophageal echocardiography has been widely used as a diagnostic tool during the past two decades to detect cardiac abnormalities that are not visible or poorly visible with transthoracic echocardiography. At present, transesophageal echocardiography is a cornerstone of modern diagnosis of several cardiac diseases, providing diagnostic, prognostic and therapeutic information. In this review, the present status of transesophageal echocardiography not only as a diagnostic tool, underlining its effects on clinical decision making, but also as a monitoring adjunct for many interventional cardiac procedures is examined.

Robotic and minimally invasive cardiac surgery

The transition of mitral valve surgery away from the traditional sternotomy approach toward more minimally invasive strategies continues to evolve. The use of telemanipulative robotic arms with near 3-dimensional valve visualization has allowed for near complete endoscopic robotic-assisted mitral valve surgery, providing increased patient satisfaction and cosmesis. Studies have shown rapid recovery times without sacrificing perioperative safety or the durability of surgical repair. Although a steep learning curve exists as well as high fixed and disposable costs, continued technological development fueled by increasing patient demand may allow for further expansion in the use of robotic-assisted minimal invasive surgery.

Numerical simulation of blood flow in an anatomically-accurate cerebral venous tree

Although many blood flow models have been constructed for cerebral arterial trees, few models have been reported for their venous counterparts. In this paper, we present a computational model for an anatomically accurate cerebral venous tree which was created from a computed tomography angiography (CTA) image. The topology of the tree containing 42 veins was constructed with 1-D cubic-Hermite finite element mesh. The model was formulated using the reduced Navier-Stokes equations together with an empirical constitutive equation for the vessel wall which takes both distended and compressed states of the wall into account. A robust bifurcation model was also incorporated into the model to evaluate flow across branches. Furthermore, a set of hierarchal inflow pressure boundary conditions were prescribed to close the system of equations. Some assumptions were made to simplify the numerical treatment, e.g., the external pressure was considered as uniform across the venous tree, and a vein was either distended or partially collapsed but not both. Using such a scheme we were able to evaluate the blood flow over several cardiac cycles for the large venous tree. The predicted results from the model were compared with ultrasonic measurements acquired at several sites of the venous tree and agreements have been reached either qualitatively (flow waveform shape) or quantitatively (flow velocity magnitude). We then discuss the significance of this venous model, its potential applications, and also present numerical experiments pertinent to limitations of the proposed model.

The Swan-Ganz catheter as a teaching tool for the anesthesiologist learning minimally invasive cardiac surgery

OBJECTIVE

To perform minimally invasive cardiac surgery through the smallest possible wound and with the least number of incisions in the heart or aorta, the necessary cannulations to undergo cardiopulmonary bypass must be done through peripheral vessels. A difficult skill to learn for the cardiac anesthesiologist is how to safely and efficiently position the coronary sinus catheter (Endoplege; Edwards Lifesciences LLC, Irvine, CA USA) required for retrograde cardioplegia administration.

METHODS

In patients in whom a Swan-Ganz catheter was inserted as part of the operative management strategy for non-minimally invasive heart surgery, we have been using it as a training tool to learn how to visualize and manipulate right-sided catheters under transesophageal echocardiography. We developed this teaching technique to help hone some of the necessary skills needed to place the Endoplege catheter for minimally invasive cardiac surgery. Manipulation was done with the goal of visualizing the catheter and guiding it into the coronary sinus. For a 4-month period, anesthesia records were retrospectively reviewed.

RESULTS

Fifteen patients, for a total of 19 catheter manipulations, were found in whom we had documented the use of the Swan-Ganz catheter and details about the insertion as a training tool. The coronary sinus and the catheter were visualized 100% of the time. The Swan-Ganz catheter was successfully inserted into the coronary sinus in 17 of 19 catheter manipulations.

CONCLUSIONS

The Swan-Ganz catheter can be used as a training tool to develop some of the necessary skills to place catheters into the coronary sinus with transesophageal echocardiography guidance.

Cannulation of the middle cardiac vein during MICS

Coronary sinus cannulation for retrograde cardioplegia administration during cardiac surgery is common practice. Several of the cannulas that are placed by the cardiac surgeon on open procedures are now placed by the cardiac anesthesiologist during minimally invasive cardiac surgery, including the coronary sinus catheter. The understanding of the cardiac venous anatomy is very important during coronary sinus catheter placement. We present a case where a percutaneously placed coronary sinus catheter was inadvertently placed into the middle cardiac vein but detected with the use of fluoroscopy.

Anesthesia management of totally endoscopic atrial septal defect repair with a robotic surgical system

STUDY OBJECTIVE

To investigate anesthetic techniques for robot-assisted endoscopic atrial septal defect (ASD) repair.

DESIGN

Clinical observational study.

SETTING

Operating room of a general military hospital.

PATIENTS

56 adult, ASA physical status 1 and 2 patients undergoing elective general anesthesia.

INTERVENTIONS

After induction of general anesthesia, a left-sided, double-lumen endotracheal tube was positioned to allow single left-lung ventilation and contralateral CO(2) pneumothorax (capnothorax). With ultrasound guidance, peripheral cardiopulmonary bypass (CPB) catheters were placed.

MEASUREMENTS AND MAIN RESULTS

All patients tolerated single left-lung ventilation before CPB; however, hypoxia (oxygen saturation < 90%) occurred in 11 (19.6%) patients post-CPB, which required treatment with continuous positive airway pressure. Fifteen (26.8%) patients had hypotension secondary to capnothorax, which was treated with transfusion and vasopressors. Aortic cross-clamp time was 43.6 ± 11.2 minutes, and CPB time was 106.7 ± 12.4 minutes. The median intensive care unit stay was 21 hours and postoperative hospital stay was 4 to 7 days.

CONCLUSIONS

The key issue for anesthetic management of robot-assisted totally endoscopic ASD repair is maintaining stable hemodynamics and oxygenation, especially during one-lung ventilation and capnothorax.

Anesthetic considerations during minimally invasive mitral valve surgery

Advances in instruments and visualization tools as well as circulatory systems for cardiopulmonary bypass during the late 1990s have stimulated widespread adoption of minimally invasive mitral valve surgery (MIMVS). Today, MIMVS is the standard approach for many surgeons and institutions. There are multiple benefits of MIMVS. Patient satisfaction and improved cosmesis are important. Additionally, studies have consistently shown faster recovery times and less associated pain with MIMVS. Statistically significant improvement in bleeding, transfusion, incidence of atrial fibrillation, and time to resumption of normal activities with MIMVS has also been shown when comparing MIMVS with conventional mitral surgery. Most important, these benefits have been achieved without sacrificing perioperative safety or durability of surgical repair. Although a steep learning curve still exists given the high level of case complexity, continued development fueled by increasing patient demand may allow for even further expansion in the use of minimal invasive techniques.

Anthropometric estimation of femoral venous cannula length for cardiovascular surgery

BACKGROUND

Femoral vein cannulation is an alternative method for central cannulation. However, no clinical guidelines have been established for optimal insertion length of femoral venous cannula. The purpose of the present study was to evaluate the correlation between the insertion length of femoral venous cannula (L), and the sum of the length from femoral artery (FA) puncture site to umbilicus (P-U) and the length from umbilicus to lower border of the sternum (U-S) as an anthropometric estimation for adult patients undergoing cardiovascular surgery using femoral vein cannulation. We also attempted to determine the insertion length of femoral venous cannula by the patient's height and weight.

METHODS

P-U and U-S were measured after anesthesia induction. L was measured after femoral venous cannula tip was positioned at the junction of inferior vena cava and right atrium using transesophageal echocardiography. The relationship between the sum of P-U and U-S (P-U-S), and L was analyzed by Pearson's correlation analysis. Bland-Altman analysis was used to compare the agreement between P-U-S and L. Multiple linear regression analysis was performed to identify the height and weight factors capable of predicting L.

RESULTS

One-hundred study patients were enrolled. P-U-S was highly correlated with L (r = 0.95). The bias and precision were -2.60 ± 8.57 mm. L was predicted from height and weight: L (mm) = 0.82 × height (cm) + 1.18 × weight (kg) + 188.46.

CONCLUSIONS

P-U-S can be used as a reliable anthropometric estimation of L during adult cardiovascular surgery using femoral vein cannulation.

Intraoperative echocardiography in valvular heart disease: an evidence-based appraisal

Intraoperative (IO) transesophageal echocardiography (TEE) is widely used for assessing the results of valvular heart disease (VHD) surgery. Epiaortic ultrasonography (EAU) has been recommended for prevention of perioperative strokes. To what extent does high-quality evidence justify the widespread use of these imaging modalities? In March 2009, we searched MEDLINE (PubMed and OVID interfaces) and EMBASE for studies published in English using database-specific controlled vocabulary describing the concepts of IOTEE, cardiac surgery, VHD, and EAU. We found no randomized trials or studies with control groups assessing the impact of IOTEE in VHD surgery. Pooled analysis of 8 observational studies including 15,540 patients showed an average incidence of 11% for prebypass surgical changes and 4% for second pump runs, suggesting that patients undergoing VHD surgery may benefit significantly from IOTEE, particularly from postcardiopulmonary bypass IOTEE in aortic repair and mitral repair and replacement, but less so in isolated aortic replacement. Further available indirect evidence was satisfactory in the test accuracy and surgical quality control aspects, with low complication rates for IOTEE. The data supporting EAU included 12,687 patients in 2 prospective randomized studies and 4 nonrandomized, controlled studies, producing inconsistent outcome-related results. Despite low-quality scientific evidence supporting IOTEE in VHD surgery, we conclude that indirect evidence supporting its use is satisfactory and suggests that IOTEE may offer considerable benefit in valvular repairs and mitral replacements. The value of IOTEE in isolated aortic valve replacement remains less clear. Evidence supporting EAU is scientifically more robust but conflicting. These findings have important clinical policy and research implications.

Surgical, anesthetic, perfusion-related advances in minimal access surgery

As we enter the fifth decade in cardiac surgery, traditionally cardiac surgery has been performed using a median sternotomy with cardiopulmonary bypass providing great access to the heart and all the surrounding structures. During the last decade, there has been a paradigm shift in the methods by which surgery has been performed. The invasiveness of many procedures has been dramatically reduced, with significantly superior outcomes, as evidenced by improved survival, fewer complications, and quicker return to functional health and productive life. This resulted in significant interest and excitement in adopting less invasive techniques in cardiac surgery. Unfortunately, this was an unrealistic expectation due to the limitations that existed in cardiac surgical techniques and conventional endoscopic instruments, cardiac anesthesia, and cardiopulmonary bypass techniques. In this article, the advances in minimally invasive surgical, cardiac anesthesia, and cardiopulmonary bypass techniques in the evolution of minimal access cardiac surgery are summarized.

Impact of Perioperative Transesophageal Echocardiography in Aortic Valve Replacement

Intraoperative transesophageal echocardiography (TEE) is currently being used routinely during aortic valve replacement (AVR). TEE provides information that can lead to modifications of anesthetic and surgical care that leads to improved outcome. Numerous studies have shown that modifications in therapy occur from 10% to more than 40% of cases. The impact of TEE can be divided among modifications of therapy before, during, and after cardiopulmonary bypass. Before cardiopulmonary bypass, TEE can provide prognostic information, optimize hemodynamics, and diagnose conditions that were not appreciated before surgery, including patient—prosthesis mismatch. TEE can guide and modify the placement of various bypass cannulae. After bypass, TEE verifies the surgical result, rules out left and right ventricular outflow tract obstruction, and assures stable hemodynamics. Although current guidelines state that aortic valve surgery is a class IIa indication for TEE use, the authors' experience suggests that TEE should be routinely used in AVR.

Intraoperative monitoring with transesophageal echocardiography: indications, risks, and training

There are benefits and risks to the use of TEE. The benefits are derived from the physiologic information that TEE provides, which may not be as readily obtained by any other technique. The risks of TEE are those related to mechanical trauma from the probe, as well as those of an incorrect TEE interpretation by the echocardiographer. Intraoperative TEE is a powerful monitoring and diagnostic tool. Performance of TEE requires special skills. As has been discussed, training guidelines exist. As more clinical studies are published, the indications for intraoperative TEE are likely to expand. Class-I recommendations for intraoperative echocardiography have been listed. The authors have discussed some of the issues involved with each class-I indication. Performance of the TEE is not an end in itself and should not distract the anesthesiologist from the primary goal of patient care. With proper training and experience, the anesthesiologist may learn how to use TEE to improve patient care.

Two Hundred Forty Minimally Invasive Mitral Operations Through Right Minithoracotomy

BACKGROUND

This study reports of our 7-year experience with minimally invasive mitral valve operations using the transthoracic clamp technique, reviewing morbidity and mortality as well as echocardiographic follow-up results.

METHODS

Between 1997 and 2004, 241 patients (121 male; aged 56 +/- 14 years) underwent minimally invasive mitral valve surgery through right thoracotomy using the transthoracic clamp technique. Reconstructions were done in 199 patients, and 42 valves were replaced. Mean length of incision was 7.0 +/- 1.2 cm. Mean preoperative New York Heart Association functional class was 2.6 +/- 0.9.

RESULTS

Thirty-day mortality was 3.3% (n = 8). Operating, bypass, and cross-clamp times averaged 241 +/- 52, 142 +/- 40, and 84 +/- 26 minutes, respectively. Seven patients (2.9%) had conversion to sternotomy. Nine patients (3.7%) underwent reexploration for bleeding. Mean intensive care unit and hospital stay were 18 hours and 8.1 days, respectively. Mean follow-up was 30 +/- 18 months (range, 3 to 76). Echocardiographic follow-up documented persistently competent valve function in all but 6 patients who had grade III regurgitation. Five of them underwent mitral valve re-reconstruction and 1 underwent transplantation. At 76 months, freedom from nontrivial recurrent mitral regurgitation and reoperation were 92.3% and 96.2%, respectively. Actuarial survival at 76 months, including early mortality, was 90.7%. Thoracic wounds were free from infection in all patients.

CONCLUSIONS

This study demonstrates that the direct vision, transthoracic clamp technique for minimally invasive mitral valve surgery is reproducible with low mortality and morbidity rates. It results in excellent cosmesis and abolished the risk of thoracic wound infection. Results are comparable to midterm outcomes of conventional operations.

Minimally Invasive Reoperative Isolated Valve Surgery: Early and Mid-Term Results

OBJECTIVE

Minimally invasive, nonsternotomy approaches for valve procedures may reduce the risks associated with cardiac surgery after prior sternotomy and may improve outcomes. We analyzed our institutional experience to test this hypothesis.

METHODS

Between 1995 and 2002, 498 patients with previous cardiac operations via sternotomy underwent isolated valve surgery: 337 via median sternotomy (aortic = 160; mitral = 177) and 161 via mini-thoracotomy (aortic = 61; mitral = 100). Data were collected prospectively using the New York State Cardiac Surgery Report Form.

RESULTS

Preoperative incidences of congestive heart failure, renal disease, and nonelective procedures were higher in the sternotomy group. Hospital mortality was significantly lower with the minimally invasive approach, 5.6% (9/161) versus 11.3% (38/337) (univariate, p = 0.04). However, multivariate analysis (odds ratio: 95% confidence intervals, p value) revealed that chronic obstructive pulmonary disease (6.6: 1.4 to 3.1, p = 0.001), renal disease (4.1: 1.52 to 11.2, p = 0.01), cerebrovascular disease (2.2: 1.03 to 4.78, p = 0.04), and ejection faction <30% (1.5: 0.96 to 5.5, p = 0.06) were associated with increased mortality. While mean bypass time, cross-clamp times, and stroke rates were comparable between groups, patients undergoing minimally invasive valve surgery had no deep wound infections (0% vs 2.4%, p = 0.05), less need for blood products (p = 0.02), and shorter hospital stays (p = 0.009). Five-year survival was higher with minimally invasive techniques as compared to a sternotomy approach (92.4 +/- 2% and 86.0 +/- 2%, respectively, p = 0.08).

CONCLUSIONS

Reoperative valve surgery can be safely performed using a nonsternotomy, minimally invasive approach, with at least equal mortality, less hospital morbidity, decreased hospital length of stay, and slightly favorable mid-term survival as compared to sternotomy.

Endovascular Aortic Clamping for Pseudoaneurysms of the Aortic Root With Aortic Regurgitation

BACKGROUND

We propose a safer strategy for surgical treatment of retro-sternal pseudoaneurysms of the aortic root with severe aortic regurgitation. The objective was to allow safer re-entry in a quite and bloodless field eliminating the risk of ventricular distension and avoiding deep hypothermia.

METHODS

In 6 patients presenting with postsurgical aortic root pseudoaneurysms in close proximity to the sternum associated with aortic regurgitation, we used the following techniques: femorofemoral cardiopulmonary bypass; transfemoral aortic endoclamping; percutaneous retrograde cardioplegia administration before sternotomy in patients with normal descending aorta; femoroaxillary cardiopulmonary bypass; transaxillary aortic endoclamping; percutaneous retrograde cardioplegia administration before sternotomy in patients with concomitant disease of the descending aorta.

RESULTS

All patients survived the operation and were discharged home. Arterial cannulation and endoclamp insertion were uneventful. Reentry was uncomplicated. Deep hypothermia was avoided in all cases. No occurrences of even minor neurologic problems were observed. None of these patients experienced a postoperative low cardiac output syndrome. Postoperative course was complicated in 1 patient with re-entry for bleeding; acute renal insufficiency requiring hemofiltration in 2 patients; pneumonia in 1 patient; and soft tissues sternotomy infection in 1 patient.

CONCLUSIONS

In patients presenting with a pseudoaneurysm of the aortic root attached to the sternum and concomitant aortic regurgitation it is possible, by closed chest endovascular aortic clamping, to eliminate risks of ventricular distension and to avoid deep hypothermia.

Transaxillary Aortic Endoclamping for Ascending Aortic Pseudoaneurysm and Dissected Descending Aorta

Patients presenting with pseudoaneurysm of the aortic root close to the sternum, severe aortic regurgitation, and chronic dissection of the descending aorta represent a formidable surgical challenge. Closed chest circulatory arrest in this setting carries a high risk of myocardial or brain damage. We propose a modification of the port-access technique that allows control and access of the pseudoaneurysm, avoiding the need for closed chest circulatory arrest. Our strategy is based on transaxillary endoclamping of the ascending aorta and combines the advantages of antegrade aortic flow with the possibility of stopping the heart and venting the left ventricle before sternotomy.

Intraoperative Echocardiography in Minimally Invasive Cardiac Surgery and Novel Cardiovascular Surgical Techniques

Minimally invasive cardiovascular surgery has been developed in an effort to decrease hospital length of stay and cost by decreasing pulmonary and neurologic complications, pain, chest trauma, and infection. The smaller incisions provide less direct cardiac visualization and exposure, which makes transesophageal echocardiography an essential and integral part of these innovative procedures. Transesophageal echocardiography does not obstruct the surgical field and can perform a full evaluation of the heart. This includes assessment of the aorta and great vessels, valve function, ventricular wall motion, placement of catheters and cannulae, hemodynamic monitoring, and immediate evaluation of surgical results and complications.

Mitral Valve Repair in the Treatment of Heart Failure

Heart failure continues to be one of the leading causes of hospitalizations and mortality in the United States. Mitral valve regurgitation in patients with heart failure is most often a functional abnormality and as such represents a different disease entity from other more common causes of regurgitation. In general, in patients with heart failure the mitral valve structure is normal; however, regurgitation is secondary to changes in left ventricular (LV) structure and function, including mitral annular dilatation and changes in LV geometry. Mitral regurgitation affects almost all patients with heart failure as a preterminal or terminal event, and carries a high morbidity and mortality. Medical management is limited to treatment with diuretics and afterload reduction. Unfortunately, once significant amounts of mitral regurgitation are manifest, medical treatment alone is generally associated with poor long-term survival and outcome. Surgical treatment by means of undersized annuloplasty type repairs has shown great promise, for preventing worsening heart failure and improving overall LV function.

Current State of Intraoperative Echocardiography

Intraoperative use of echocardiography is becoming more prevalent and is now considered an essential part of modern cardiac surgery. Echocardiography can be performed intraoperatively using transesophageal, epicardial or epiaortic, and substernal approaches. These techniques have a variety of applications in evaluating myocardial and valvular function, assessing aortic atheroma, and determining adequacy of various kinds of repair and reconstruction. Future applications will most likely involve more compact equipment, the implementation of epicardial and transesophageal real-time three-dimensional echocardiography, and better use of provocative methods of intraoperative testing.

Combined Use of Transesophageal ECHO and Fluoroscopy for the Placement of Left Ventricular Pacing Leads via the Coronary Sinus

Biventricular pacing is an emerging technology for treatment of congestive heart failure. Left ventricular leads are most commonly placed through the coronary sinus (CS) into an epicardial coronary vein. Cannulation of the CS can be difficult and standard guiding catheters have a tendency to displace during lead advancement. This study found that transesophageal echocardiography facilitated CS cannulation in complex cases requiring antecedent lead extraction.

Endoscopic mitral valve repair: feasible, reproducible, and durable

OBJECTIVE

We sought to document the feasibility, safety, and effectiveness of performing mitral valve repair using a totally endoscopic approach.

METHODS

Between February 1997 and October 1, 2001, 187 patients underwent totally endoscopic mitral valve repair at our institution. The mean age was 60.7 +/- 13.1 years, and 62% were male. Median preoperative functional class and degree of mitral regurgitation were II and 4, respectively. Data collection included an institutional protocol assessing procedure-related pain, cosmesis, and functional recovery. Statistical analysis included Kaplan-Meier and Cox regression methods. Mean follow-up was 19 +/- 15.2 months and was 100% complete.

RESULTS

Associated atrial procedures were performed in 9.1% (n = 17) of the patients. Two patients required intraoperative conversion to sternotomy. Thoracoscopic re-evaluation for suspected bleeding (n = 19) was part of our aggressive postoperative management. One patient required sternotomy for control of bleeding. Hospital mortality included 1 (0.5%) patient and was not technology related. There were 1 early and 6 late reoperations, 4 of which were due to endocarditis. No risk factors for repair failure could be detected. Freedom from mitral valve reoperation at 4 years was 93.3% +/- 2.6%. The median degree of mitral regurgitation at follow-up was 0. Ninety-three percent of the patients were highly satisfied with either no or mild postoperative pain, and 98.4% believed they had an aesthetically pleasing scar.

CONCLUSIONS

Totally endoscopic mitral valve repair can be done safely with excellent results and a high degree of patient satisfaction. It is now our exclusive approach for isolated atrioventricular valve disease.

The Role of Transesophageal Echocardiography in Perfusion Management

Intraoperative transesophageal echocardiography (TEE) has been a valuable tool in cardiac surgery. The TEE probe can easily be inserted after endotracheal intuba tion to provide continuous monitoring and diagnosis during surgery. The role of TEE in the operating room is always expanding. This article examines the role of TEE specifically for cardiopulmonary bypass and perfusion management.

Minimally invasive aortic valve replacement: echocardiographic and clinical results

BACKGROUND

Port access has been described for mitral and bypass surgery. The purpose of this study was to review the clinical and echocardiographic outcomes of aortic valve replacement by use of port access.

METHODS

Between 1996 and 1999, 153 port-access aortic valve replacements were performed at our institution. The mean age was 63 years (range 16-91 years); 58% were male. The New York Heart Association mean class was III; 18% were in class IV. Thirteen percent had diabetes, 42% hypertension, 7% prior transient ischemic episode or stroke, 7% lung disease, 3% renal failure, and 13% previous surgery. Echocardiograms were obtained after valve replacement in 125 patients (96 intraoperative transesophageal and 97 transthoracic echoes).

RESULTS

Median length of stay was 8 days. There were no intraoperative deaths; 10 patients (6.5%) died in the postoperative period. Stroke occurred in 4 (2.6%), sepsis in 5 (3.3%), renal failure in 5 (3.3%), pneumonia in 3 (2%), and wound infection in 1 (0.7%). Tissue prosthesis was present in 83 and a mechanical prosthesis in 42. No or trace regurgitation was seen on 94 of 96 (98%) postbypass intraoperative echocardiograms and mild on 2. On follow-up echocardiograms, moderate regurgitation was seen in 4 of 97 (4.1%), mild-to-moderate in 2 (2.1%), mild in 18 (18.6%), and no or trace in 71 (73.2%). Of those who had aortic regurgitation on intraoperative or follow-up echocardiograms, it was paravalvular in 8.

CONCLUSIONS

Minimally invasive aortic valve replacement with a port-access approach is feasible, even in high-risk patients. Small incisions, a low infection rate, and a short length of stay are attainable. However, the complications associated with traditional aortic valve replacement still occur. Echocardiography is valuable both for intraoperative monitoring and follow-up of this new procedure.

The role of transoesophageal echocardiography for anaesthetists

Transoesophageal echocardiography has proved to be a valuable monitor of global and regional ventricular function in the perioperative period. In addition, it is increasingly used by anaesthetists as a diagnostic tool in patients with heart disease. During the past year, important steps towards quality assurance and the standardization of perioperative echocardiography were undertaken, and our understanding of the perioperative cardiovascular structure and function improved.

Minimal access reoperative mitral and aortic valve surgery

Minimally invasive cardiac surgery has allowed surgeons to perform valve procedures with a morbidity and mortality comparable with conventional resternotomy approaches while reducing postoperative ventilatory and intensive care unit requirements and overall hospital length of stay. Additionally, patient satisfaction with rapid recovery, earlier return to work, and improved cosmetic results has pushed the pendulum of reoperative valve surgery towards minimally invasive techniques. We reviewed our institutional data consisting of 129 patients requiring reoperative valve surgery over the past 4 years, which was accomplished using these minimally invasive approaches.

Mitral Regurgitation

Chronic severe mitral regurgitation is a surgically correctable disorder. Advances in cardiac surgery (including mitral valve repair and less invasive operations), a low postoperative complication rate, and improved long-term prognosis have reduced the threshold for surgical referral. Choosing the optimal timing for surgery remains the cardinal problem. Clinical and diagnostic imaging information is essential to the detection of occult myocardial decompensation, for which surgical correction should be sought. Surgery is not generally recommended in asymptomatic patients without signs of progressive disease. The final decision regarding timing of surgery should be made based on all the clinical data, the patient's choice, and the available surgical expertise. The use of medical therapy to delay the time to surgery is not supported by large trials; however, small short-term studies of chronic vasodilator therapy show favorable hemodynamic effects.

Atheromas of the thoracic aorta: clinical and therapeutic update

Atherosclerotic lesions of the thoracic aorta have recently been recognized as an important cause of stroke and peripheral embolization, which may result in severe neurologic damage as well as multiorgan failure and death. Their prevalence is approximately 27% in patients with previous embolic events. Transesophageal echocardiography is the modality of choice for the diagnosis of these atheromas, although computed tomography, magnetic resonance imaging and intraoperative epiaortic ultrasound are complementary. Two clinical syndromes account for the embolic phenomena, atheroemboli and, more commonly, thromboemboli. In addition to such superimposed thrombi, plaque thickness (especially > or =4 mm) also correlates with embolic risk. This risk is high, with 12% of patients having a recurrent stroke within approximately one year, and up to 33% of patients having a stroke or peripheral embolus. In addition, aortic atheromas (as seen with intraoperative transesophageal echocardiography and intraoperative epiaortic ultrasound) are an important cause of stroke during heart surgery requiring cardiopulmonary bypass. Such strokes occur during approximately 12% of cardiac operations employing cardiopulmonary bypass when aortic arch atheromas are seen with transesophageal echocardiography (six times the general intraoperative stroke rate). Although anticoagulant strategies have been reported with encouraging results in nonrandomized studies, prospective, randomized data must be developed before an effective and safe treatment strategy can be determined. This review details the current state of knowledge in this area, including the clinical and pathologic evidence that thoracic aortic atherosclerosis is an important embolic source, data which guide current therapy and future directions for clinical investigation.

Multivessel coronary bypass grafting with minimal access using cardiopulmonary bypass

The port-access approach for coronary artery bypass grafting is an excellent technique for minimal access, multivessel coronary revascularization. Patient selection criteria, technical aspects, and clinical results are reviewed.

Intraoperative multiplane transesophageal echocardiography for guiding direct myocardial gene transfer of vascular endothelial growth factor in patients with refractory angina pectoris

Gene transfer for therapeutic angiogenesis represents a novel treatment for patients with chronic angina refractory to standard medical therapy and not amenable to conventional revascularization. We sought to assess the role of intraoperative multiplane transesophageal echocardiography (MPTEE) in guiding injection of naked DNA encoding vascular endothelial growth factor (VEGF) into the left ventricular (LV) myocardium of patients with refractory angina. After exposing the LV myocardium via a limited lateral thoracotomy, each of 17 patients in this series received 4 separate injections of VEGF DNA into different myocardial sites. Initial injections in the first patient produced intracavitary microbubbles, indicating injection of DNA into the LV chamber. Subsequently, each injection was preceded by a test injection of agitated saline. The absence of microbubbles while visualizing the LV cavity during the test injection verified that the ensuing injection of DNA would not be inadvertently squandered in the LV chamber itself. Intracavitary LV microbubbles were observed by MPTEE in 13 of 64 (20.3%) saline test injections and in 8 of 16 (50.0%) patients in which saline test injection was used, leading to adjustments in needle position. MPTEE imaging detected a previously unknown large, apical left ventricular thrombus in one patient, thereby preventing inadvertent injection of VEGF DNA through the myocardium into the thrombus. Imaging during and after injection verified no deleterious impact on LV function. We conclude that MPTEE is a useful tool for ensuring that myocardial gene therapy performed by direct needle injection results in gene transfer to the LV myocardium.