W. Randolph Chitwood

Outcomes and perioperative hyperglycemia in patients with or without diabetes mellitus undergoing coronary artery bypass grafting

BACKGROUND The association between perioperative hyperglycemia and outcomes in patients with and without diabetes mellitus undergoing coronary artery bypass grafting is not well defined. We measured the association between perioperative hyperglycemia and outcomes among patients undergoing coronary artery bypass grafting. METHODS We report a historic cohort study of 1574 patients who had undergone coronary artery bypass grafting between 1998 and 1999, 545 (34.6%) with diabetes. Perioperative blood glucose level was defined as the average of all blood glucose tests obtained on the day of and the day after surgery. Outcomes were 30-day mortality, infection rates (sternum, harvest site, sepsis, pneumonia, urinary tract), and resource utilization. RESULTS After adjusting for diabetes status and calculated preoperative mortality or mediastinitis risk scores, each 50 mg/dL (2.78 mmol/L) blood glucose increase was not statistically associated with higher mortality (odds ratio 1.37; 95% confidence interval, 0.98 to 1.92; p = 0.07), or higher infection rate (odds ratio 1.23, 95% confidence interval 0.94 to 1.60; p = 0.14). Each 50 mg/dL blood glucose increase was associated with longer postoperative days by 0.76 days (95% confidence interval 0.36 to 1.17 days; p < 0.001), increased hospitalization charges by 2824 dollars (95% confidence interval 1599 dollars to 4049 dollars; p < 0.001), and increased hospitalization cost by 1769 dollars (95% confidence interval 928 dollars to 2610 dollars; p < 0.001). In the unadjusted analysis, infections occurred more frequently in patients with diabetes (6.6% vs 4.1%, p = 0.03). CONCLUSIONS Perioperative hyperglycemia is associated with increased resource utilization in patients undergoing coronary artery bypass grafting with and without diabetes.

Video-Assisted and Robotic Mitral Valve Surgery: Toward an Endoscopic Surgery

Our group at East Carolina University recently has shown the efficacy of new video-assisted mitral valve surgery. Moreover, we review the evolution and predict the future of endoscopic and robotic-enabling technology for cardiac valve surgery. Herein, a video-assisted mitral valve operation is described and early results are discussed. Cardiopulmonary bypass was established via the femoral vessels, and blood cardioplegic arrest was induced by using a new percutaneous, transthoracic cross-clamp. A 6-cm minithoracotomy was used in each patient. Videoscopy was helpful for suture placement, chord reconstruction, leaflet resection, knot tying, and valve ring or prosthesis positioning. Thus far, 85 patients have undergone this surgery successfully with a 1.2% surgical mortality rate. Our early study with cost data is reviewed in detail. Cardiopulmonary perfusion times and cross-clamp periods for the entire group have been longer than for conventional sternotomy patients at 167 +/- 4.6 minutes and 120 +/- 4.0 minutes, respectively, but complications have been less. Complex repairs and replacements were possible. Bleeding, ventilatory times, and hospital lengths of stay have been reduced. One patient required a second surgery for a failed repair. Recently, we have used voice-activated, robotic assistance for camera control in 28 patients. This has decreased camera motion artifact and lens cleaning while providing direct cerebral-eye tracking of instruments by the surgeon. From this and other studies we reviewed, we conclude that video-assisted and computer-assisted robotic techniques are safe and may be the pathway to truly endoscopic mitral valve surgery.

Video-assisted minimally invasive mitral valve surgery

OBJECTIVE This study was done to determine the potential benefits of minimally invasive mitral surgery performed with intraoperative video assistance. METHODS From May 1996 until March 1997, a minithoracotomy and video assistance were used in 31 consecutive patients undergoing mitral repair (n = 20) and replacement (n = 11). Their ages ranged from 18 to 77 years (59 +/- 2.6 years; mean +/- standard error of the mean). Ejection fractions were 35% to 62% (55% +/- 1.5%). Operations were done with either antegrade/retrograde (n = 10) or antegrade (n = 19) cold blood cardioplegia and a new transthoracic crossclamp or with ventricular fibrillation (n = 2). Peripheral arterial cannulation (n = 28) and pump-assisted right atrial drainage (n = 26) were used most often. RESULTS No hospital deaths occurred, but the 30-day mortality was 3.2%. Complications included deep venous thrombosis and a phrenic nerve palsy in one patient each. No patient had a stroke or required reoperation for bleeding. Postoperative echocardiography showed excellent valve function in all but one patient. Cardiopulmonary bypass and arrest times averaged 183 +/- 7.2 and 136 +/- 5.5 minutes, respectively. Compared with 100 patients having conventional mitral valve operations, these patients had significantly shorter hospitalization times (8.6 +/- 0.5 vs 5.1 +/- 0.9 days, p = 0.05). Moreover, 81% of the later cohort were discharged between day 3 and 5 (3.6 +/- 0.2 days). Hospital charges (decreases 27%, p = 0.05) and costs (decreases 34%, p < 0.05) were less than in conventional operations. Patient follow-up suggested minimal perioperative pain and rapid recovery. CONCLUSIONS Early results suggest that video-assisted minimally invasive mitral operations can be done safely. These methods may benefit patients through less morbidity, earlier discharge, and lower cost.

Robotic Surgical Training in an Academic Institution

ObjectiveTo detail robotic procedure development and clinical applications for mitral valve, biliary, and gastric reflux operations, and to implement a multispecialty robotic surgery training curriculum for both surgeons and surgical teams. Summary Background DataRemote, accurate telemanipulation of intracavitary instruments by general and cardiac surgeons is now possible. Complex technologic advancements in surgical robotics require well-designed training programs. Moreover, efficient robotic surgical procedures must be developed methodically and safely implemented clinically. MethodsAdvanced training on robotic systems provides surgeon confidence when operating in tiny intracavitary spaces. Three-dimensional vision and articulated instrument control are essential. The authors’ two da Vinci robotic systems have been dedicated to procedure development, clinical surgery, and training of surgical specialists. Their center has been the first United States site to train surgeons formally in clinical robotics. ResultsEstablished surgeons and residents have been trained using a defined robotic surgical educational curriculum. Also, 30 multispecialty teams have been trained in robotic mechanics and electronics. Initially, robotic procedures were developed experimentally and are described. In the past year the authors have performed 52 robotic-assisted clinical operations: 18 mitral valve repairs, 20 cholecystectomies, and 14 Nissen fundoplications. These respective operations required 108, 28, and 73 minutes of robotic telemanipulation to complete. Procedure times for the last half of the abdominal operations decreased significantly, as did the knot-tying time in mitral operations. There have been no deaths and few complications. One mitral patient had postoperative bleeding. ConclusionRobotic surgery can be performed safely with excellent results. The authors have developed an effective curriculum for training teams in robotic surgery. After training, surgeons have applied these methods effectively and safely.

Minimally invasive mitral valve repair using transthoracic aortic occlusion

This report describes a minimally invasive mitral valve repair done through a limited (6-cm) thoracic incision. The patient was supported by peripheral extracorporeal perfusion with cardiac arrest established using a new transthoracic aortic cross-clamp and antegrade blood cardioplegia. The patient was discharged on postoperative day 3 with minimal pain. This less invasive approach to mitral valve surgery may offer combined advantages to patients by increasing comfort, expediting recovery, and decreasing surgical costs by using modified traditional methods compared with specialized intraaortic occlusive balloons.

Robotic mitral valve repair: experience with the da Vinci system.

BACKGROUND As part of a Food and Drug Administration trial, mitral repairs were performed in 38 patients using the robotic da Vinci surgical system (Intuitive Surgical, Inc, Mountain View, CA). Prospectively, we evaluated safety and efficacy in performing both simple and complex mitral repairs. METHODS Eligible patients had nonischemic moderate to severe mitral insufficiency. Operative techniques included peripheral cardiopulmonary perfusion, a 4- to 5-cm mini-thoracotomy, transthoracic aortic occlusion, and antegrade blood cardioplegia. Transesophageal echocardiograms were done intraoperatively with three-dimensional reconstructions. Successful repairs were defined as mild or less residual regurgitation. RESULTS Enhanced three-dimensional visualization of mitral leaflets and the subvalvar apparatus allowed safe, dexterous intracardiac tissue manipulation. All patients had successful valve repairs including quadrangular resections, sliding plasties, and edge-to-edge approximations, as well as both chordal transfers and replacements. There were no operative deaths, strokes, or device-related complications. One patient required valve replacement for hemolysis and 1 was reexplored for bleeding. There were no incisional conversions. Both robotic repair and total operating times decreased significantly from 1.9 +/- 0.1 and 5.1 +/- 0.1 hours (mean +/- standard error of the mean) for the first 19 patients to 1.5 +/- 0.1 (p = 0.002) and 4.4 +/- 0.1 hours (p = 0.04) for the last 19 operations, respectively. Total hospital length of stay for patients was 3.8 +/- 0.6 days. Of all patients, 31 (82%) had a 4-day or less length of stay. Seven patients (18%) had stays between 5 and 9 days (6.4 +/- 1.0). CONCLUSIONS This study shows that the da Vinci surgical system (Intuitive Surgical, Inc) has few limitations in performing complex valve repairs. Articulated wrist-like instruments and three-dimensional visualization enabled precise tissue telemanipulation. Future robotic design advances and adjunctive suture technologies may promote continuing evolution of robotic cardiac operations.

Robotic mitral valve repairs in 300 patients: A single-center experience

OBJECTIVES Mitral valve repair is the standard therapy for patients with degenerative (myxomatous) disease and severe mitral regurgitation. Robotic mitral valve repair provides the least-invasive surgical approach. We report the largest single-center robotic mitral valve repair experience. METHODS Between May 2000 and November 2006, 300 patients underwent a robotic mitral valve repair (daVinci Surgical System; Intuitive Surgical, Inc, Sunnyvale, Calif). All operations were done with 3- to 4-cm right intercostal access, transthoracic aortic occlusion, and peripheral cardiopulmonary bypass. Repairs included 1 or a combination of trapezoidal/triangular leaflet resections, sliding plasties, chordal transfers/replacements, edge-to-edge approximations, and ring annuloplasties. Echocardiographic and survival follow-up were 93% and 100% complete, respectively. RESULTS There were 2 (0.7%) 30-day mortalities and 6 (2.0%) late mortalities. No sternotomy conversions or mitral valve replacements were required. Immediate postrepair echocardiograms showed the following degrees of mitral regurgitation: none/trivial, 294 (98%); mild, 3 (1.0%); moderate, 3 (1.0%); and severe, 0 (0.0%). Complications included 2 (0.7%) strokes, 2 transient ischemic attacks, 3 (1.0%) myocardial infarctions, and 7 (2.3%) reoperations for bleeding. The mean hospital stay was 5.2 +/- 4.2 (standard deviation) days. Sixteen (5.3%) patients required a reoperation. Mean postoperative echocardiographic follow-up at 815 +/- 459 (standard deviation) days demonstrated the following degrees of mitral regurgitation: none/trivial, 192 (68.8%); mild, 66 (23.6%); moderate, 15 (5.4%); and severe, 6 (2.2%). Five-year Kaplan-Meier survival was 96.6% +/- 1.5%, with 93.8% +/- 1.6% freedom from reoperation. CONCLUSIONS Robotic mitral valve repair is safe and is associated with good midterm durability. Further long-term follow-up is necessary.

Evolution of mitral valve surgery: toward a totally endoscopic approach

BACKGROUND Our study evaluates a series of video-assisted minimally invasive mitral operations, showing safe progression toward totally endoscopic techniques. METHODS Consecutive patients with isolated mitral valve disease underwent either manually directed (n = 55) or voice-activated robotically directed (n = 72) video-assisted mitral operations. Cold blood cardioplegia, a transthoracic aortic clamp, a 5-mm endoscope, and a 5-cm minithoracotomy were used. This video-assisted minimally invasive mitral operation cohort was compared with a previous sternotomy-based mitral operation cohort (n = 100). RESULTS Group demographics, New York Heart Association classification, and cardiac function were similar. Repairs were performed in 61.8% manually directed (n = 34), 75.0% robotically directed (n = 54), and 54% sternotomy-based (N = 54) mitral operations. The robotically directed technique showed a significant decrease in blood loss, ventilator time, and hospitalization compared with the sternotomy-based technique. Manually directed mitral operations compared with robotically directed mitral operations had decreased arrest times (128.0 +/- 4.5 minutes compared with 90.0 +/- 4.6 minutes; p < 0.001) and decreased perfusion times (173.0 +/- 5.7 minutes compared with 144.0 +/- 4.6 minutes; p < 0.001). In the minimally invasive mitral operation cohort, complications included reexploration for bleeding (2.4%; n = 3) and one stroke (0.8%), whereas the 30-day mortality was 2.3% (n = 3). CONCLUSIONS Video-assisted mitral surgery provides safe and effective results when compared with conventional sternal approaches. These positive results show a safe and stepwise evolution toward a totally endoscopic mitral valve operation.

Successful linking of the Society of Thoracic Surgeons adult cardiac surgery database to Centers for Medicare and Medicaid Services Medicare data.

BACKGROUND The Centers for Medicare and Medicaid Services (CMS) Medicare database complements The Society of Thoracic Surgeons (STS) database by providing information about long-term outcomes and cost. This study demonstrates the feasibility of linking STS data to CMS data and examines the penetration, completeness, and representativeness of the STS database. METHODS Using variables common to both STS and CMS databases, STS operations were linked to CMS data for all CMS coronary artery bypass graft surgery (CABG) hospitalizations discharged between 2000 and 2007, inclusive. For each CMS CABG hospitalization, it was determined whether a matching STS record existed. RESULTS Center-level penetration (number of CMS sites with at least one matched STS participant divided by the total number of CMS CABG sites) increased from 45% to 78%. In 2007, 854 of 1,101 CMS CABG sites (78%) were linked to an STS site. Patient-level penetration (number of CMS CABG hospitalizations done at STS sites divided by the total number of CMS CABG hospitalizations) increased from 51% to 84%. In 2007, 94,409 of 111,967 CMS CABG hospitalizations (84%) were at an STS site. Completeness of case inclusion at STS sites (number of CMS CABG cases at STS sites linked to STS records divided by the total number of CMS CABG cases at STS sites) increased from 88% to 97%. In 2007, 88,857 of 91,363 CMS CABG hospitalizations at STS sites (97%) were linked to an STS record. CONCLUSIONS The successful linking of STS and CMS databases demonstrates high and increasing penetration and completeness of the STS database. Linking STS and CMS data will facilitate studying long-term outcomes of cardiothoracic surgery.

Minimally invasive video-assisted mitral valve surgery: A 12-year, 2-center experience in 1178 patients

OBJECTIVE To review a 2-institution experience with minimally invasive mitral valve surgery over a 12-year period. METHODS We prospectively collected data on all patients having minimally invasive mitral valve surgery through a right minithoracotomy between May 1996 and May 2008. RESULTS A total of 1178 patients included 941 (79.9%) patients having mitral valve repair and 237 (20.1%) having mitral valve replacement. The mean age was 61.1 +/- 13.9 years, mean ejection fraction was 52.8% +/- 12.1%, and 221 patients (18.8%) were having reoperations. Operative mortalities for mitral valve repair and mitral valve replacement were 2.1% and 4.6%, and for isolated primary MVP and MVR were 0.2% and 3.6%, respectively. Repair techniques included annuloplasty (98.2%), leaflet resection (40.7%), sliding plasty (21.0%), chordal transfer (9.0%), and neochordae placement (7.4%), with no or trivial residual MR in over 97% of patients. In patients having mitral valve replacement, a bioprosthesis was placed in 101 patients (42.6%) and a mechanical valve in 136 (57.4%). Concomitant procedures included atrial fibrillation ablation (22.5%), tricuspid valve surgery (5.4%), and atrial septal defect closure (9.4%). Nineteen patients (1.6%) experienced intraoperative conversion to sternotomy. Twenty-two patients (1.9%) had a reoperation at a mean of 732 +/- 1014 days. Independent predictors of in-hospital mortality included New York Heart Association class III/IV (odds ratio 3.62), diabetes (odds ratio 2.81), bypass time > 180 minutes (odds ratio 2.63), preoperative atrial fibrillation (odds ratio 2.53), and age > 70 years (odds ratio 2.29). Prior cardiac surgery was not a significant predictor of mortality. CONCLUSIONS Video-assisted mitral valve surgery is safe with high rates of repair, low morbidity, and excellent outcomes. Reoperation after previous median sternotomy is not an independent predictor of mortality with this approach. Operative risk is increased if surgery is delayed until the onset of atrial fibrillation.