Anno Diegeler

Neuromonitoring and neurocognitive outcome in off-pump versus conventional coronary bypass operation☆

BACKGROUNDnCardiopulmonary bypass seems to be a major cause for both intraoperative microemboli and cerebral hypoperfusion. This study investigates high intensive transient signals (HITS) in transcranial Doppler ultrasound (TCD) and serum levels of the neurobiochemical marker protein S-100 in patients who underwent coronary artery bypass operation without cardiopulmonary bypass (off-pump CABG) in comparison with the conventional procedure using cardiopulmonary bypass (CPB). The results are related to the neuropsychologic outcome in both surgical groups.nnnMETHODSnForty patients were randomized in 2 groups (20 conventional and 20 off-pump CABG). Neurocognitive status was assessed preoperatively and postoperatively. Venous serum levels of S-100 protein were measured before and after coronary operation, HITS were measured in the middle cerebral artery during the operation.nnnRESULTSnThe median value of HITS was 394.5 (0 to 2217) in the conventional versus 11 (0 to 50) in the off-pump group, p less than 0.0001. Postoperative S-100 serum levels were: 3.76 (0.13 to 11.2) microg/L (conventional) versus 0.13 (0.04 to 1.01) microg/L (off-pump), p less than 0.0001. Postoperative cognitive testing showed significantly different results with a postoperative impairment of 90% of the patients in the conventional group versus no impairment in the off-pump group.nnnCONCLUSIONSnCognitive impairment seems to be strongly associated to CPB and the occurrence of micro-emboli. The off-pump technique appears to be promising in order to eliminate the source of these neuropyschologic impairments following CABG operation.

Total endoscopic computer enhanced coronary artery bypass grafting

OBJECTIVEnIn an effort to minimize access in coronary artery bypass (CAB) surgery, a total endoscopic approach using computer enhanced technology was developed.nnnMETHODSnBy July 1999 the da Vinci telemanipulation system (Intuitive Surgical, Mountain View, CA) was used in 66 patients with coronary artery disease. In 12 patients undergoing routine coronary artery bypass grafting (CABG) (group 1) the internal thoracic artery (ITA) to left anterior descending artery (LAD) anastomosis was performed remotely using the system. In 32 patients (group 2) endoscopic dissection of the ITA was performed followed by a conventional minimally invasive direct coronary artery bypass (MIDCAB) operation. In 22 patients (group 3) the complete operation was performed endoscopically through 4 ports (total endoscopic coronary artery bypass, TECAB). Port-Access cardiopulmonary bypass with cardioplegic arrest was used for TECAB.nnnRESULTSnIn group 1 the time for performing the ITA to LAD anastomosis was 17 +/- 10 min. Mean graft flow was 38 +/- 25 ml/min. One anastomosis leaked and was repaired manually. In group 2 in 31/32 patients (96%) the ITA harvest was successfully performed with the system at mean of 61 +/- 27 min. There was a substantial learning curve associated with ITA take-down. In one patient a dissection caused insufficient free ITA graft flow which necessated additional vein grafting. Postoperative angiography demonstrated graft patency in all cases. In the TECAB group, the operation could be completed through four ports in 18 of the 22 patients (82%) with operating times in the range 220-507 min. In four patients, elective conversion to a minithoracotomy was required due to failure to identify the LAD (1), bleeding from the anastomosis (1), grafting of a diagonal branch (1) and torsion of the pedicle (1). One patient required reoperation for bleeding from an ITA side-branch. Median intubation time was 13 h and stay on ICU and hospitalization were 20 h and 7 days, respectively. A 3-month follow-up angiography revealed patent grafts in all TECAB patients.nnnCONCLUSIONnEndoscopic ITA harvesting and performing of arterial anastomoses can be safely performed with the da Vinci system. TECAB is possible on the arrested heart with good functional results. However, a substantial learning curve has to be overcome which is reflected in long operation times and an initial significant conversion rate.

Pain and quality of life after minimally invasive versus conventional cardiac surgery

BACKGROUNDnThe aim of this study was to evaluate pain and quality of life after minimally invasive cardiac operations in comparison with conventional cardiac operations.nnnMETHODSnFrom October 1996 to May 1997 a total of 338 patients were interviewed daily using standard scoring systems (myocardial revascularization, n = 160; mitral valve reconstruction or replacement, n = 58; aortic valve replacement, n = 120).nnnRESULTSnRegarding ventricular function and intensive care and hospital stay, there were no significant differences between groups. Pain decreased until the seventh postoperative day in all patients. Patients with a lateral minithoracotomy (minimally invasive revascularization and mitral valve operations) had lower pain levels from the third postoperative day onward. There were no differences in quality of life, postoperative wound healing, or stability of the bony thorax.nnnCONCLUSIONSnIn cardiac operations overall pain levels are relatively low. After minimally invasive procedures with lateral minithoracotomy, earlier mobilization is possible because of a better stability of the bony thorax, resulting in lower pain levels.

Robot-assisted minimally invasive solo mitral valve operation ☆ ☆☆ ★ ★★

1. Pacifico AD, Mandke NV, McGrath LB, Colvin EV, Bini RM, Bargeron LM Jr. Repair of congenital pulmonary venous stenosis with living autologous atrial tissue. J Thorac Cardiovasc Surg 1985;89:604-9. 2. Van Praagh R, Harken AH. Total anomalous pulmonary venous drainage to the coronary sinus: a revised procedure for its correction. J Thorac Cardiovasc Surg 1972;64:132-5. 3. Van de Wal HJCM, Hamilton DI, Godman MJ, Harnick E, Lacquet LK, van Oort A. Pulmonary venous obstruction following correction for total anomalous pulmonary venous drainage: a challenge. Eur J Cardiothorac Surg 1992;6:545-9. 4. Coles JG, Yemets E, Najm HK, Lukanich JM, Perron J, Wilson GJ, et al. Experience with repair of congenital heart defects using adjunctive endovascular devices. J Thorac Cardiovasc Surg 1995;110:1513-20. 5. Van Son JAM, Danielson GK, Puga FJ, Edwards WD, Driscoll DJ. Repair of congenital and acquired pulmonary vein stenosis. Ann Thorac Surg 1995;60:144-50. 6. Wilson WR Jr, Ilbawi MN, DeLeon SY, Quinones JA, Arcilla RA, Sulayman RF, et al. Technical modifications for improved results in total anomalous pulmonary venous drainage. J Thorac Cardiovasc Surg 1992;103:861-71. 7. Lacour-Gayet F, Rey C, Planche C. Pulmonary vein stenosis: description of a sutureless surgical technique using the pericardium in situ. Arch Mal Coeur Vaiss 1996;89:633-6.

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.

Minimally invasive coronary artery bypass grafting without cardiopulmonary bypass : Early experience and follow-up

BACKGROUNDnThere is renewed interest in coronary artery bypass grafting without cardiopulmonary bypass using the anterolateral minithoracotomy approach. We evaluated 209 patients who underwent minimally invasive direct coronary artery bypass grafting using an anterolateral minithoracotomy. The anastomosis was performed under direct vision on the beating heart without using cardiopulmonary bypass.nnnMETHODSnThe procedure was performed using a 6- to 9-cm left (or right) anterolateral thoracotomy for internal thoracic artery graft harvesting and anastomosis. Different devices were used for local immobilization. In 195 patients a single internal thoracic artery to left anterior descending coronary artery bypass was performed, in 3 patients a single right internal thoracic artery to right coronary artery bypass, and in 11 patients the radial artery was used together with the internal thoracic artery as a T-graft.nnnRESULTSnConversion to sternotomy or cardiopulmonary bypass was necessary in 10 (4.7%) patients. Intraoperative myocardial infarction was observed in 4 patients (1.9%). Early postoperative redo operation was necessary in 5 patients (2.4%). Mortality was 0.47%. Postoperatively, 191 patients (91.3%) underwent angiography for graft patency control. The overall patency rate was 97.3%. Minor stenosis of the internal thoracic artery graft was observed in 18 patients (9.4%); moderate stenosis was observed in 5 patients (2.6%). Midterm angiographic follow-up after 6 months was performed in 58 patients. The patency rate was 98.2%. One patient with severe symptomatic stenosis (1.7%) underwent reoperation.nnnCONCLUSIONSnWith the help of the local immobilization systems off-pump coronary artery bypass grafting was safely performed through a minithoracotomy. The incidence of intraoperative and postoperative complications was low and follow-up showed good results. Thus, minimally invasive direct coronary artery bypass grafting is an excellent technique for arterial revascularization in patients having symptomatic left anterior descending coronary artery disease.

Minimally invasive saphenous vein harvesting techniques: morphology and postoperative outcome

BACKGROUNDnConventional saphenous vein harvest is associated with numerous complications, which may be reduced by minimally invasive vein-harvesting techniques. The integrity of the venous endothelium must be guaranteed before using new saphenous vein harvesting techniques. This short-term study compared the clinical outcome of two minimally invasive techniques with the conventional technique, and compared morphology as documented by light and electron microscopy.nnnMETHODSnNinety-two patients were prospectively randomized into three groups. Two different minimally invasive techniques of greater saphenous vein harvesting were used in sixty-two patients. One used a video-assisted dissector (group A, n = 31), and one used a light-coupled retractor (group B, n = 31). Thirty patients were treated by the conventional technique (group C).nnnRESULTSnIncision lengths were 7.6+/-2.1 cm in group A and 9.3+/-3.2 cm in group B, as compared with 38.9+/-8.7 cm in the conventional group. Harvesting time was prolonged by a mean of 26% when using a minimally invasive technique. Conversion rate to the open technique was 3 of 31 (9.3%) in group A and 2 of 31 (6.2%) in group B. No wound complications were noted in group A, but one wound inflammation was seen in group B; only a mild hematoma was seen in both groups. Edge necrosis, wound separation and inflammation were noted in the conventional group. Light and electron microscopy revealed no significant denudation of the endothelial layer in groups A and B as compared with group C.nnnCONCLUSIONSnThese data show an excellent postoperative result when using the minimally invasive technique as compared with the conventional group. The safety of the technique is demonstrated by the preservation of endothelial integrity.

The revival of surgical treatment for isolated proximal high grade LAD lesions by minimally invasive coronary artery bypass grafting

BACKGROUNDnPercutaneous coronary angioplasty (PTCA) and stent implantation have become the first-line intervention for patients with isolated proximal LAD-lesions. Minimally invasive direct coronary artery bypass surgery (MIDCAB) has recently been developed to reduce surgical invasiveness for single LAD revascularization. This study focus on the question whether MIDCAB could be an alternative treatment for isolated proximal LAD lesions.nnnMETHODSnStarting in 1996, MIDCAB was performed in 618 patients. Angiography was performed before discharge and repeated after 6 months at follow-up examination. In an ongoing randomized trial 150 patients with an indication for treatment of a LAD lesion have been included to compare the mid-term outcome after PTCA (n=79) vs. MIDCAB (n=71).nnnRESULTSnIn 618 MIDCAB procedures 30-day mortality was 0.6%, perioperative myocardial infarction rate was 1.6%. The conversion rate to sternotomy was 3.4%. The learning curve was demonstrated by a patency rate of 96.0% in 1997, 98.0% in 1998 and 99.1% in 1999, respectively. At 6 months patency rate was 94.4% in 1997 and 97.0% in 1998. The rate of severe stenosis >75% dropped from 5.4% in 1997 to 3.4% in 1998. The over all rate of reinterventions was 5.6%. The preliminary result of the randomized trial revealed a difference in the number of perioperative adverse events, 11.4% in the MIDCAB group vs. 6.3% in the PTCA group (P<0.05). At 6 months follow-up 88. 7% of the MIDCAB patients were free from angina vs. 58.2% of the PTCA patients (P<0.02). Restenosis and a positive stress test was diagnosed in 27.9% of the PTCA patients vs. 8.4% of the MIDCAB patients (P<0.02). Reintervention was necessary in 27.9% of the patients after PTCA vs. 8.4% of the patients after MIDCAB.nnnCONCLUSIONnMIDCAB is a safe and effective but technically demanding procedure. Perioperative adverse events may be expected, but early as well as mid-term patency rate are good. When compared to PTCA, the freedom from angina and the need for additional revascularization procedures after 6 months is statistically better for patients having MIDCAB surgery. Thus, MIDCAB is considered a valuable alternative for isolated proximal high grade LAD lesions.

Endoscopic internal thoracic artery dissection leads to significant reduction of pain after minimally invasive direct coronary artery bypass graft surgery

BACKGROUNDnThe aim of this study was to evaluate postoperative pain levels after endoscopic versus conventional internal thoracic artery (ITA) dissection for minimally invasive direct coronary artery bypass graft surgery (MIDCABG) surgery. Results were compared with pain levels associated with conventional cardiac bypass operations through a median sternotomy.nnnMETHODSnOf 190 patients included in this prospective study, 24 patients had endoscopic ITA takedown (MIDCABG-endo) using the da Vinci telemanipulator followed by a manual coronary anastomosis through a left minithoracotomy. A conventional MIDCABG operation (MIDCABG-conv) was performed in 73 patients with ITA preparation under direct vision. Postoperative pain levels after conventional CABG through a median sternotomy (CABG-conv, n = 93) served as controls. A standarized questionnaire including visual analog scale (VAS) was used for prospective pain assessment from POD 1 to 7.nnnRESULTSnPain levels (VAS) declined in all groups from POD 1 to 7. Overall pain levels were significantly lower in the MIDCABG-endo group as compared with MIDCABG-conv and CABG-conv groups, respectively (p < 0.001, general linear model). There was no significant difference between the MIDCABG-conv and CABG-conv (p = not significant, general linear model) groups. Furthermore, patients after MIDCABG-endo required fewer nonsteroidal anti-inflammatory drugs and opioid medications, postoperatively.nnnCONCLUSIONSnAn endoscopic ITA takedown in MIDCABG surgery leads to significantly reduced postoperative pain levels possibly because of less rib retraction.

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.