Impact of diabetes mellitus on cardiac surgery outcome.

BACKGROUND: Diabetes mellitus is an established independent risk factor related to significant morbidity and mortality after cardiac surgical procedures. METHODS: Data on 16,184 patients undergoing cardiac surgery with and without cardiopulmonary bypass between April 1996 and August 2001 were prospectively evaluated. Diabetes mellitus as a patient related risk factor was subjected to univariate analysis to identify potential associations to 28 intra- and postoperative outcome variables. Outcome variables having a significant association with diabetes mellitus (p < 0.05) were then subjected to a stepwise logistic regression model to identify the influence of diabetes mellitus as compared to additional 30 different patient related risk factors and treatment variables. Diabetes mellitus was defined as glucose intolerance treated either dietary, with oral hypoglycemics or with insulin. RESULTS: Overall prevalence of diabetes mellitus was 33.3 %. Compared to non-diabetic patients the group with diabetes mellitus was older (p < 0.0001) and had a significantly lower ejection fraction (p < 0.0001). 15 outcome variables having a significant association with diabetes mellitus were identified. Furthermore, diabetes mellitus could be identified as an independent predictor for 7 postoperative outcome variables (prolonged ICU-stay, sternal instability and/or infection, sternal revision and refixation respiratory insufficiency, postoperative delirium, perioperative stroke, renal dysfunction, postoperative reintubation). CONCLUSION: Diabetes mellitus is a significant independent predictor for several postoperative outcome variables after cardiac surgery associated with higher postoperative morbidity and prolonged hospital stay.

Minimally invasive approach for redo mitral valve surgery: a true benefit for the patient.

OBJECTIVES: Redo mitral valve surgery via sternotomy is associated with a substantial morbidity and mortality. This study evaluated a minimally invasive technique for mitral valve redo procedures. MATERIAL AND METHODS: Out of a series of 394 patients undergoing mitral valve repair or replacement via a right minithoracotomy, 39 patients underwent redo mitral valve surgery (59+/-13 years, 23 female). Previous cardiac surgeries included 17 patients with mitral valve repair, 6 patients with mitral valve replacement, 3 patients with aortic valve replacement, 2 patients with atrial septal defect closure, and 11 patients with coronary artery bypass grafting (CABG). In all cases, femoro-femoral cannulation was performed. The port access technique was applied in patients undergoing redo valve surgery. In patients with prior CABG, the operation was performed using deep hypothermia and ventricular fibrillation. RESULTS: In all cases, sternotomy was avoided. The mitral valve was replaced in 20 patients and repaired in 19. Time of surgery and cross-clamp time were comparable with the overall series (168+/-73 [redo] vs 168+/-58 min and 52+/-21 [redo] vs 58+/-25 min). Mortality was 5.1%. One patient had transient hemiplegia due to the migration of the endoclamp. All other patients had uneventful outcomes and normal mitral valve function at 3-month's follow-up. CONCLUSION: Redo mitral valve surgery can be performed safely using a minimally invasive approach in patients with a previous sternotomy. The right lateral minithoracotomy offers excellent exposure. It minimizes the need for cardiac dissection, and thus, the risk for injury. Avoiding a resternotomy increases patient comfort of redo mitral valve surgery.

[Mitral valve repair versus mitral valve replacement]. / Mitralklappenrekonstruktion vs. Mitralklappenersatz.

Over the past 40 years mitral valve surgery has changed dramatically. After initial enthusiasm with the introduction of valve prostheses in the 1960s, a renewed interest in repair techniques began in the 1970s with the introduction of annuloplasty rings. These repair techniques revealed that the integrity of the subvalvular apparatus plays an important role in left ventricular function. When considering the major series comparing early and late results of mitral valve repair versus prosthetic mitral valve replacement, operative mortality rate is lower for patients with mitral valve repair. Long-term results also show a superior survival rate after mitral valve reconstruction. In addition, several problems can occur with the prosthetic valve, such as thromboembolism and endocarditis. All of these factors favor valve repair over replacement. The success of mitral valve repair depends on many factors: etiology of the mitral valve disease and the resultant pathomorphology of the valve, patient's circumstances such as age or contraindication for anticoagulation, and the experience of the surgeon. The decision whether to repair or replace the mitral valve depends on these factors. Data in the literature and in large collective databases reflect the advantages of mitral valve repair, with over 75 % of current mitral valve surgeries being repairs.In the past 5 years the exposure of the mitral valve through a right lateral minithoracotomy using video assistance has developed into a widespread technique. This approach allows complex mitral valve repair as well as mitral valve replacement even with biological stentless prostheses, with decreased morbidity. The addition of radiofrequency ablation for restoration of sinus rhythm enhances the outcome after mitral valve surgery, and can also be easily performed through a minithoracotomy technique.

Mitral valve repair versus mitral valve replacement.

Over the past 40 years mitral valve surgery has changed dramatically. After initial enthusiasm with the introduction of valve prostheses in the 1960s, a renewed interest in repair techniques began in the 1970s with the introduction of annuloplasty rings. These repair techniques revealed that the integrity of the subvalvular apparatus plays an important role in left ventricular function. When considering the major series comparing early and late results of mitral valve repair versus prosthetic mitral valve replacement, operative mortality rate is lower for patients with mitral valve repair. Long-term results also show a superior survival rate after mitral valve reconstruction. In addition, several problems can occur with the prosthetic valve, such as thromboembolism and endocarditis. All of these factors favor valve repair over replacement. The success of mitral valve repair depends on many factors: etiology of the mitral valve disease and the resultant pathomorphology of the valve, patient's circumstances such as age or contraindication for anticoagulation, and the experience of the surgeon. The decision whether to repair or replace the mitral valve depends on these factors. Data in the literature and in large collective databases reflect the advantages of mitral valve repair, with over 75% of current mitral valve surgeries being repairs. In the past 5 years the exposure of the mitral valve through a right lateral minithoracotomy using video assistance has developed into a widespread technique. This approach allows complex mitral valve repair as well as mitral valve replacement even with biological stentless prostheses, with decreased morbidity. The addition of radiofrequency ablation for restoration of sinus rhythm enhances the outcome after mitral valve surgery, and can also be easily performed through a minithoracotomy technique.

Cerebral microemboli during minimally invasive and conventional mitral valve operations.

BACKGROUND: Intraoperative cerebral microembolism may cause postoperative neurologic damage. The aim of this study was to determine the frequency of cerebral microembolic signals (MES) during minimally invasive surgery (MIS) and conventional (conv.) mitral valve operations and to determine the association of MES with various stages of the operation. METHODS: Intraoperative computer-aided transcranial Doppler measurements were performed to detect cerebral microemboli in 21 patients undergoing MIS and in 14 patients undergoing conv. mitral valve operation. We calculated the mean embolic rate for three time periods: P1, start of the operation until aortic clamping; P2, aortic clamping until clamp removal; and P3, declamping until end of surgery. RESULTS: There was no significant difference in the total number of detected cerebral MES between both patient groups (MIS 1,014+/-753, conv. 937+/-519; NS). In both groups, the highest number of MES were detected during the third time period when the heart regained effective ejection (MIS 875+/-746, conv. 680+/-462; p > 0.5). CONCLUSIONS: Transcranial Doppler was useful to detect cerebral microemboli in MIS and conv. mitral valve operation. We found no increased risk of cerebral microembolism during the minimally invasive method compared with the conventional technique.

The Leipzig experience with robotic valve surgery.

OBJECTIVES: The study describes the single-center experience using robot-assisted videoscopic mitral valve surgery and the early results with a remote telemanipulator-assisted approach for mitral valve repair. MATERIAL AND METHODS: Out of a series of 230 patients who underwent minimally invasive mitral valve surgery, in 167 patients surgery was performed with the use of robotic assistance. A voice-controlled robotic arm was used for videoscopic guidance in 152 cases. Most recently, a computer-enhanced telemanipulator was used in 15 patients to perform the operation remotely. RESULTS: The mitral valve was repaired in 117 and replaced in all other patients. The voice-controlled robotic arm (AESOP 3000) facilitated videoscopic-assisted mitral valve surgery. The procedure was completed without the need for an additional assistant as "solo surgery." Additional procedures like radiofrequency ablation and tricuspid valve repair were performed in 21 and 4 patients, respectively. Duration of bypass and clamp time was comparable to conventional procedures (107 A 34 and 50 A 16 min, respectively). Hospital mortality was 1.2%. Using the da Vinci telemanipulation system, remote mitral valve repair was successfully performed in 13 of 15 patients. CONCLUSION: Robotic-assisted less invasive mitral valve surgery has evolved to a reliable technique with reproducible results for primary operations and for reoperations. Robotic assistance has enabled a solo surgery approach. The combination with radiofrequency ablation (Mini Maze) in patients with chronic atrial fibrillation has proven to be beneficial. The use of telemanipulation systems for remote mitral valve surgery is promising, but a number of problems have to be solved before the introduction of a closed chest mitral valve procedure.

Computer-enhanced mitral valve surgery: toward a total endoscopic procedure.

The aim of the study was to develop a computer-enhanced, video-assisted approach for mitral valve repair as a potential step toward a complete endoscopic procedure. In 10 patients with nonischemic mitral valve insufficiency, computer-enhanced telemetric mitral valve repair using the Intuitive surgical telemanipulation system was performed. A femorofemoral bypass was initiated using Port-Access (Heartport, Redwood City, CA) cannulation. A small minithoracotomy was made in the right 4th intercostal space, and a custom-made rib retractor was placed. The pericardium was opened manually, and four traction stay sutures were placed to enhance exposure. After endoaortic balloon clamping, the left atrium was opened and stabilized. The end-effectors were placed in the left atrium through two ports (3rd ICS and 6th ICS, midaxillary line). A 30 degrees three-dimensional (3D)-videoscope angled up was placed through the incision. Mitral valve repair was then performed remotely from the surgical console. This included inspection of the valve, leaflet resection, leaflet repair, and ring implantation. After completion of the repair and testing of the valve, the end effectors were withdrawn, and the left atrium was closed manually using standard endoscopic instruments (Heartport). In all but 1 patient, successful repair, including quadrangular resection, chordal shortening, Whooler-plasty, and Alfieri-plasty, could be accomplished using the computer-enhanced telemanipulation system. A partial ring was implanted in 6 patients and a complete ring was implanted in 3 patients, respectively. Time for surgery, CPB, and clamp time were 170 to 330 minutes (median, 185 minutes), 140 to 220 minutes (median, 149 minutes), and 78 to 133 minutes (median, 94 minutes), respectively. In one patient, intraoperative transesophageal echocardiography (TEE) showed insufficient repair, a second surgery was performed via an enlarged left thoracotomy. One patient with recurrent mitral insufficiency had to have a second surgery on postoperative day 3 for a torn-out ring. Median time of hospitalization was 8 days. At 3 months follow-up (completed in 7 patients), all patients had improved clinically. Computer-enhanced mitral valve repair is feasible and can be performed with good functional results. The telemanipulation system offers the potential for true endoscopic mitral valve repair. However, surgical time is prolonged, and a learning curve has to be overcome.

The evolution of minimally invasive valve surgery--2 year experience.

OBJECTIVES: The aim of the study was to evaluate the evolution of Port-Access minimally invasive mitral valve surgery to a robot assisted video assisted solo surgery approach. METHODS: One hundred and twenty-nine patients with non-ischemic mitral valve disease underwent 3D-video assisted mitral valve surgery via a 4 cm right lateral minithoracotomy using femoro-femoral bypass and endoaortic clamping. Transcranial Doppler and continuous transesophageal echocardiography were used to monitor placement and positional stability of the endoclamp. After the initial series (group I, n = 62), a simplified solo surgical technique using voice controlled robotic assistance for videoscope guidance was used in the last 67 patients (group II). RESULTS: After an initial learning curve and modifications of catheter design, the procedure could be steadily redefined and simplified. In the last 67 patients, the procedure was completed without the need for an additional assistant as 'solo surgery'. The mitral valve was repaired in 72 and replaced in all other patients. Duration of bypass and clamp time steadily improved during our study and in the most recent 67 patients average 107 +/- 34 and 48 +/- 16 min, respectively. The voice controlled robotic arm (AESOP 3000, Automated Endoscope System for Optimal Positioning) provided a stable and precise video image with excellent exposure of all valvular and subvalvular structures. Hospital mortality was high in the early series (mean survival 88.7% at 804 +/- 35 days; 95% CI: 735-873) and partially procedure related (aortic dissection in two patients). In group II, hospital mortality has declined to 3.0% (mean survival 97.0% at 568 +/- 12 days; 95% CI: 553-600). CONCLUSION: Port-Access minimally invasive mitral valve surgery has evolved to be a reliable video assisted technique with reproducible results. Surgery can now be performed almost in the same time as with conventional techniques. Robotic assistance has enabled a solo surgery approach.

Extracardiac repair versus intracardiac baffle repair of complex unroofed coronary sinus.

Complex unroofed coronary sinus with a persistent left superior vena cava has as its commonest major associated intracardiac anomaly a partial or complete atrioventricular canal defect. In this clinical setting, biventricular repair with construction of a complex intra-atrial baffle from the pulmonary veins to the mitral valve has a reported mortality rate of as high as 50%. Looking for an improvement, we have carried out an extracardiac repair of the anomalous systemic venous component with atrial septation. In 2 infants (aged 7 and 12 weeks) with unroofed coronary sinus, bilateral superior venae cavae, right isomerism, and complete atrioventricular canal, in addition to patch closure of the ventricular component of the atrioventricular septal defect, a baffle was constructed between the pulmonary veins and the mitral valve. In four subsequent infants (aged 7,10,16, and 20 weeks) with unroofed coronary sinus, bilateral superior venae cavae, complete atrioventricular canal, right isomerism (n = 2), and mild infundibular stenosis (n = 1), repair consisted of end-to-side anastomosis of the left superior vena cava to the right superior vena cava and complete repair of the atrioventricular canal and associated conditions. There was no mortality. The early postoperative course in the two patients with intra-atrial baffle was characterized by increased left-atrial pressure (18 and 20 mm Hg), with varying degrees of pulmonary venous congestion, supraventricular tachycardias, and systemic hypotension. The pulmonary venous congestion increased, so that one patient was successfully converted 10 weeks postoperatively to an extracardiac repair with septation of the atria and the other will probably follow. In the 4 patients with a primary extracardiac repair, the hemodynamic result was excellent, with a median left-atrial pressure of 11 mm Hg on the first postoperative day. At a median follow-up of 12 months, all 5 patients with an extracardiac repair are clinically well with widely patent anastomoses between the left and right superior venae cavae. The extracardiac repair technique for complex unroofed coronary sinus, as opposed to the intra-atrial baffle repair, avoids creation of a small and low-compliance left-atrial compartment with the potential for development of pulmonary venous congestion.