T. Walther

The evolution of minimally invasive mitral 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.

Quality of computer enhanced totally endoscopic coronary bypass graft anastomosis – comparison to conventional technique

OBJECTIVE Aims of the study were to develop an endoscopic technique to perform robot assisted coronary anastomoses, using a computer enhanced telemanipulator and to compare the quality of the anastomoses with those performed using a standard open technique. METHODS A surgical telemanipulator with two instrument arms and a central videoscopic arm was used to perform remote endoscopic coronary artery bypass grafting on isolated porcine hearts. The end effectors and the videoscope were placed through three 10 mm port incisions. All anastomoses (Cx to LAD) were performed using a double armed 7-0 Prolene suture of 5 or 7 cm in length. All operations were performed remotely from the master console using ten times magnification, tremor filtering and 3:1 motion scaling. Initially 20 anastomoses were performed to develop and train the technique. Then, 20 robot-assisted anastomoses (group I) were compared with 20 anastomoses using a standard open parachute technique (group II). All anastomoses were checked for patency and leakage. Patency was confirmed by bench angiography. After fixation, all anastomoses were macroscopically evaluated for patency, intactness, alignment, intimal tears and dehiscence. Both angiographic and pathologic evaluations were performed with the examiners blinded to the technique of anastomosis. RESULTS In the initial feasibility series, time for anastomosis was 18.2 +/- 9.1 min. All anastomoses were patent although minor stenoses were found in two and minor leakage was noted in five anastomoses. In the second series all anastomoses were patent, not leaking and showed a good run-off at angiography. Mean time for anastomosis in group I was 12.8 +/- 2.4 min as compared with 6.3 +/- 0.2 min in group II (P < 0.001), respectively. Macroscopic analysis demonstrated equal quality for both groups. There were no stenoses, no intimal tears and no dehiscences. All anastomoses had a normal alignment and intact suture lines. CONCLUSION Using the Intuitive surgical telemanipulator, it is possible to remotely perform endoscopic coronary anastomoses with the same quality as with an open standard technique after a brief learning curve. This will enable true endoscopic coronary artery bypass grafting with a precision that has not been achieved with any other previously applied endoscopic technique.

The Leipzig Experience with Robotic Valve Surgery

Abstract 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 Å 34 and 50 Å 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.

Dexterity enhancement in endoscopic surgery by a computer-controlled mechanical wrist

SummaryThe use of conventional endoscopic instruments results in inaccurate and time-consuming techniques due to the limited range of motion. Telemanipulation systems may overcome these constraints. This study compares individual performance using a surgical tele-manipulator with either four or six degrees of freedom (DOF). Twenty non-professionals and 10 professionals (endoscopic surgeons; > 100 endoscopic procedures) performed a specially-designed set of tasks using the Intuitive Surgical tele-manipulation system at full capacity with six DOF, or in a reduced mobility mode with only four DOF (wrist-locked). Time and error rate for performing each task were assessed. In the non-professional group both time to perform the tasks and error rates were reduced when working with a six DOF system, as compared with the four DOF system. Dexterity enhanced by using the wrist reduced the time needed to complete a complex endoscopic task by 40%. In the professional group the time needed to perform the task was signi...

Minimally Invasive Approach for Redo Mitral Valve Surgery: A True Benefit for the Patient

Abstract  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‐months 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.

Transmyocardial laser revascularization with the holmium:YAG laser: loss of symptomatic improvement after 2 years

OBJECTIVE Whether transmyocardial laser revascularization (TMLR) provides a long-term benefit in terms of relief of angina, improvement of exercise tolerance, left ventricular function, and myocardial perfusion. METHODS Forty-one patients underwent TMLR using a holmium:YAG-laser, 14 as TMLR alone (group A), 27 with additional aortocoronary bypass grafting (group B). Follow-up was obtained at 6, 12, 18, 24, and 36 months in this prospective study. RESULTS In group A patients CCS-class improved up to 18 months postoperatively, after 24 and 36 months postoperatively there was absence of a positive effect of TMLR: the CCS-class decreased to 2.4 as compared to 3.5 preoperatively After combined CABG and TMLR (group B) there was a significant decrease in angina at all times. The CCS-functional class in these patients was 1.7 at 36 months as compared to 3.5 preoperatively. There was no significant change in exercise tolerance as compared to preoperatively. Left ventricular ejection fraction did not improve in either of the groups. Thallium scintigraphy indicated no improvement in myocardial perfusion in laser treated areas. The perioperative mortality was 0%, the late mortality rate was 36% in group A and 11% in group B. CONCLUSIONS In our experience, in the vast majority of patients who are subjected to TMLR alone the benefit of reduction or relief of angina and improvement in quality of life is only temporary. In addition there is no improvement in objective clinical parameters. We believe that TMLR should only be used in patients with severe angina refractory to medical treatment and requiring a symptomatic therapy.

Diabetes in patients undergoing coronary artery bypass grafting. Impact on perioperative outcome.

Eine präoperative diabetische Stoffwechsellage ist bekanntermaßen verbunden mit einem beeinträchtigten postoperativen Verlauf nach koronarer Bypasschirurgie einhergehend mit einer signifikanten Morbidität und Mortalität. Die Daten von 9682 Patienten, die sich einer aortokoronaren Bypassoperation, entweder mit (n=8917) oder ohne Einsatz der Herzlungenmaschine (HLM, extrakorporale Zirkulation; n=765) unterziehen mussten, wurden mittels einer univariaten statistischen statistischen Analyse untersucht, um einen potenziellen Einfluss eines präoperativ bekannten Diabetes mellitus in Bezug auf 26 a priori festgelegte perioperativen Outcome-Variablen zu ermitteln. Die Outcome-Variablen, für die sich eine signifikante Beziehung zu Diabetes ergab, wurden in einem nächsten Schritt zusammen mit 22 weiteren a priori gewählten patientenbezogenen Risikofaktoren und Behandlungsvariablen einer logistischen Regressionsanalyse unterzogen. Die Prävalenz der Outcome-Variablen, für die sich hieraus Diabetes mellitus als signifikanter, unabhängiger Risikofaktor herausstellte, wurde danach in der Untergruppe aller Diabetiker, gesondert nach koronarer Bypassoperation mit oder ohne Einsatz der HLM ermittelt, um den Effekt der extrakorporalen Zirkulation auf das perioperative Patienten-Outcome zu ermitteln. Diabetes mellitus wurde als Glukoseintoleranz definiert, die entweder diätetisch, mit oralen Antihyperglykämika oder mit Insulin behandelt wurde. Entsprechend der gewählten Definition des Diabetes mellitus wurde eine Prävalenz in der Gesamtgruppe von 37,1% gefunden (Bypass-OP mit HLM: 37,5%; Bypass-OP ohne HLM: 32,5%). 11 Outcome-Variablen mit einer signifikanten Beziehung zum präoperativen Diabetes wurden identifiziert. Diabetes mellitus wurde als unabhängiger Risikofaktor für postoperatives Durchgangssyndrom, postoperative Nierenfunktionsstörung und postoperative respiratorische Insuffizienz ermittelt. Die Prävalenz dieser drei Outcome-Variablen war niedriger in der Untergruppe von Diabetikern, die sich einer koronaren Bypass-OP ohne Einsatz der extrakorporalen Zirkulation unterzogen hatten im Vergleich zu denen mit Einsatz der HLM. Schlussfolgernd lässt sich sagen, dass Diabetes mellitus ein signifikanter, unabhängiger Risikofaktor für drei postoperative Outcome-Variablen nach aortokoronarer Bypassoperation ist. Darüber hinaus scheint der Wegfall der extrakorporalen Zirkulation bei aortokoronaren Bypassoperationen ohne HLM einen positiven Effekt auf das perioperative Outcome bei Diabetikern zu haben. Diabetes mellitus is an established risk factor related to significant morbidity and mortality after coronary artery bypass grafting. Data on 9682 patients undergoing coronary artery bypass grafting either with (n=8917) or without cardiopulmonary bypass (off-pump coronary artery bypass grafting; n=765) were subjected to an univariate analysis to identify potential associations between diabetes mellitus and 26 a priori selected perioperative outcome variables. Those having a significant association with diabetes were then subjected to a stepwise logistic regression model to identify the impact of diabetes as compared to additional 22 different a priori chosen patient related risk factors and treatment variables. Prevalence of outcome variables independently associated with diabetes has been determined in the subgroup of diabetics undergoing coronary artery bypass grafting with cardiopulmonary bypass or off-pump coronary artery bypass grafting surgery to evaluate the effect of avoiding cardiopulmonary bypass on perioperative patient outcome. Diabetes mellitus was defined as glucose intolerance either treated dietary, with oral hypoglycemics or with insulin. According to this definition of diabetes mellitus we found an overall prevalence of 37.1% (coronary artery bypass grafting with cardiopulmonary bypass: 37.5%; off-pump coronary artery bypass grafting: 32.5%). Eleven outcome variables having a significant association with diabetes were identified. Diabetes could be identified as an independent predictor of postoperative delirium, renal dysfunction and respiratory insufficiency. Prevalence of these three variables was lower in diabetics undergoing offpump coronary artery bypass grafting as in those undergoing coronary artery bypass grafting with cardiopulmonary bypass surgery reaching statistical significance with regard to postoperative delirium and respiratory insufficiency. In conclusion, diabetes mellitus is a significant independent predictor for three postoperative outcome variables in coronary artery bypass surgery. Avoiding cardiopulmonary bypass in diabetics seems to have a beneficial effect.

Diabetes in patients undergoing coronary artery bypass grafting

Eine präoperative diabetische Stoffwechsellage ist bekanntermaßen verbunden mit einem beeinträchtigten postoperativen Verlauf nach koronarer Bypasschirurgie einhergehend mit einer signifikanten Morbidität und Mortalität. Die Daten von 9682 Patienten, die sich einer aortokoronaren Bypassoperation, entweder mit (n=8917) oder ohne Einsatz der Herzlungenmaschine (HLM, extrakorporale Zirkulation; n=765) unterziehen mussten, wurden mittels einer univariaten statistischen statistischen Analyse untersucht, um einen potenziellen Einfluss eines präoperativ bekannten Diabetes mellitus in Bezug auf 26 a priori festgelegte perioperativen Outcome-Variablen zu ermitteln. Die Outcome-Variablen, für die sich eine signifikante Beziehung zu Diabetes ergab, wurden in einem nächsten Schritt zusammen mit 22 weiteren a priori gewählten patientenbezogenen Risikofaktoren und Behandlungsvariablen einer logistischen Regressionsanalyse unterzogen. Die Prävalenz der Outcome-Variablen, für die sich hieraus Diabetes mellitus als signifikanter, unabhängiger Risikofaktor herausstellte, wurde danach in der Untergruppe aller Diabetiker, gesondert nach koronarer Bypassoperation mit oder ohne Einsatz der HLM ermittelt, um den Effekt der extrakorporalen Zirkulation auf das perioperative Patienten-Outcome zu ermitteln. Diabetes mellitus wurde als Glukoseintoleranz definiert, die entweder diätetisch, mit oralen Antihyperglykämika oder mit Insulin behandelt wurde. Entsprechend der gewählten Definition des Diabetes mellitus wurde eine Prävalenz in der Gesamtgruppe von 37,1% gefunden (Bypass-OP mit HLM: 37,5%; Bypass-OP ohne HLM: 32,5%). 11 Outcome-Variablen mit einer signifikanten Beziehung zum präoperativen Diabetes wurden identifiziert. Diabetes mellitus wurde als unabhängiger Risikofaktor für postoperatives Durchgangssyndrom, postoperative Nierenfunktionsstörung und postoperative respiratorische Insuffizienz ermittelt. Die Prävalenz dieser drei Outcome-Variablen war niedriger in der Untergruppe von Diabetikern, die sich einer koronaren Bypass-OP ohne Einsatz der extrakorporalen Zirkulation unterzogen hatten im Vergleich zu denen mit Einsatz der HLM. Schlussfolgernd lässt sich sagen, dass Diabetes mellitus ein signifikanter, unabhängiger Risikofaktor für drei postoperative Outcome-Variablen nach aortokoronarer Bypassoperation ist. Darüber hinaus scheint der Wegfall der extrakorporalen Zirkulation bei aortokoronaren Bypassoperationen ohne HLM einen positiven Effekt auf das perioperative Outcome bei Diabetikern zu haben. Diabetes mellitus is an established risk factor related to significant morbidity and mortality after coronary artery bypass grafting. Data on 9682 patients undergoing coronary artery bypass grafting either with (n=8917) or without cardiopulmonary bypass (off-pump coronary artery bypass grafting; n=765) were subjected to an univariate analysis to identify potential associations between diabetes mellitus and 26 a priori selected perioperative outcome variables. Those having a significant association with diabetes were then subjected to a stepwise logistic regression model to identify the impact of diabetes as compared to additional 22 different a priori chosen patient related risk factors and treatment variables. Prevalence of outcome variables independently associated with diabetes has been determined in the subgroup of diabetics undergoing coronary artery bypass grafting with cardiopulmonary bypass or off-pump coronary artery bypass grafting surgery to evaluate the effect of avoiding cardiopulmonary bypass on perioperative patient outcome. Diabetes mellitus was defined as glucose intolerance either treated dietary, with oral hypoglycemics or with insulin. According to this definition of diabetes mellitus we found an overall prevalence of 37.1% (coronary artery bypass grafting with cardiopulmonary bypass: 37.5%; off-pump coronary artery bypass grafting: 32.5%). Eleven outcome variables having a significant association with diabetes were identified. Diabetes could be identified as an independent predictor of postoperative delirium, renal dysfunction and respiratory insufficiency. Prevalence of these three variables was lower in diabetics undergoing offpump coronary artery bypass grafting as in those undergoing coronary artery bypass grafting with cardiopulmonary bypass surgery reaching statistical significance with regard to postoperative delirium and respiratory insufficiency. In conclusion, diabetes mellitus is a significant independent predictor for three postoperative outcome variables in coronary artery bypass surgery. Avoiding cardiopulmonary bypass in diabetics seems to have a beneficial effect.

Abdominal aortic aneurysm repair during cardiopulmonary bypass: rationale for a combined approach

Coronary artery disease and poor left ventricular function are the most important risk factors for morbidity and mortality in patients undergoing abdominal aortic aneurysm repair. Effective screening programmes and prior revascularization procedures (percutaneous translumincal coronary angiography and coronary artery bypass graft surgery) have helped to decrease the risk of cardiac-related adverse events. There is, however, a subgroup of patients presenting with both severe coronary artery disease and/or severely impaired left ventricular function and an acutely expanding or extremely large aneurysm that represents a therapeutic challenge. Surgery is often denied to these patients for their high risk. For this selected subgroup combined coronary artery bypass graft surgery and abdominal aortic aneurysm repair rather than a staged approach represents a therapeutic alternative. This article summarizes the pathophysiological concept, that favours a simultaneous approach performing abdominal aortic aneurysm repair during cardiopulmonary bypass and updates the current indications and results for this extensive surgery.

Less-invasive coronary artery bypass grafting: different techniques and approaches.

OBJECTIVE The aim of this study was to compare four different techniques for less-invasive coronary artery bypass surgery with and without cardiopulmonary bypass (CPB) in terms of feasibility as well as in terms of the intra- and postoperative course. METHODS One hundred and fourteen patients were divided into four groups, according to the surgical technique. Group I: minithoracotomy, internal thoracic artery (ITA) harvesting and anastomosis under direct vision using cardiopulmonary bypass (CPB) on the fibrillating heart (n = 31). Group II: sternotomy and beating heart without CPB (n = 13). Group III: MIDCAB with CPB and cardioplegic cardiac arrest using endo-aortic balloon-occlusion, Port Access system (n = 9). Group IV: MIDCAB on the beating heart without CPB (n = 61). In total, 104 single and ten double graft procedures were performed using the radial artery T-graft technique in seven cases (groups III and IV). RESULTS Harvesting of the ITA graft took 41+/-16.2 min in group I and could be reduced to 31+/-8.3 min in group IV by the use of a specially-designed retractor. Complications were: death (n = 1, group I), myocardial infarction, (n = 1, group I), early occlusion of the graft (n = 1, group IV), early stenosis of the anastomosis (n = 2, groups I and IV), late stenosis of the anastomosis (n = 1, group IV), thrombosis of the femoral vein (n = 1, group III). Postoperative ventilation, ICU and hospital stay were similar among groups. CONCLUSIONS Based on our results, the following strategy has been developed: MIDCAB without CPB is the preferred technique for one-vessel graft procedures to the left anterior descendens (LAD) or RCA. The Port Access system (with CPB) is reserved as a second option for young patients requiring multiple-vessel grafting to the left coronary circulation (LAD/CX) and as a backup to avoid conversion. Sternotomy and an off-pump technique is used for single-vessel or multiple-vessel graft procedures in selected patients (emergency procedure, acute myocardial infarction, in the very obese).