INVITED COMMENTARY

Abstract

Reichenspurner and colleagues have compared two innovative surgical techniques used during 120 video-assisted minimally invasive (MI) mitral valve operations. Either the port-access (Cardiovations, Sommerville, NJ) method using an occluding intraaortic balloon (n = 60) or a simpler transthoracic aortic clamp (Scanlan International, Minneapolis, MN) technique (n = 60) was used. All operations were done through a 6 to 10 cm minithoracotomy with either a two-dimensional or three-dimensional camera, two-thirds of which were guided by AESOP (Intuitive Surgical, Mountain View, CA), a voice-activated robotic-arm assistant. There was no operative mortality and hospital stays were similar for both groups. Repair results were excellent, and met the standards of conventional mitral surgery. Operative, cardiopulmonary bypass, and cardiac arrest times were shorter when using the transthoracic clamp. Moreover, costs were significantly less in clamp patients, who also had fewer operative complications with less bleeding and fewer peripheral vascular problems. In 1998 Mohr and colleagues [1Mohr F.W. Falk V. Diegeler A. et al.Minimally invasive port-access mitral valve surgery.J Thorac Cardiovasc Surg. 1998; 115: 567-571Abstract Full Text Full Text PDF PubMed Scopus (344) Google Scholar] reported that retrograde arterial passage and balloon aortic occlusion could be fraught with neurological complications and aortic dissections. However, port-access balloon systems have evolved greatly since then, and risks are much less when applied with echocardiographic monitoring. Using aortic balloon occlusion for mitral surgery, Casselman and coworkers [2Casselman F.P. Van Slycke S. Dom H. Lambrechts D.L. Vermeulen Y. Vanermen H. Endoscopic mitral valve repair: Feasible, reproducible, and durable.J Thorac Cardiovasc Surg. 2003; 125: 273-282Abstract Full Text Full Text PDF PubMed Scopus (140) Google Scholar] has demonstrated safety efficacy and experienced few complications in his large series. With femoral artery inserted balloons, the aorta does not have to be accessed directly to establish antegrade cardioplegia or venting. Despite the elegance and seeming advantages of port-access systems, a significant learning curve exists and balloon monitoring must be continuous to assure adequate myocardial protection and a stable ascending aortic position, proximal to the innominate artery. Our group developed the transthoracic aortic clamp in 1996, and has used it in more than 450 minimally invasive video-assisted mitral valve repairs. The cost of a multiuse clamp in miniscule compared with single-use balloon systems. Moreover, the ease in clamp application maximizes surgeon familiarity and minimizes anxiety. The report of Reichenspurner and colleagues suggests diminished individual operative times when he used the clamp, and his times were similar to ours [3Felger J.E. Chitwood W.R. Nifong L.W. Holbert D. Evolution of mitral valve surgery: toward a totally endoscopic approach.Ann Thorac Surg. 2001; 72: 1203-1209Abstract Full Text Full Text PDF PubMed Scopus (109) Google Scholar]. We have experienced no aortic injuries, retrograde aortic dissections, or clamp dislodgements during surgery. However, early our series a right pulmonary artery injury and a left atrial appendage clamp tear occurred. Thus, during application, either direct visual or endoscopic confirmation of clamp position is paramount to avoid injury of these structures in the transverse sinus. This study compares these two methods and describes that minimally invasive, small thoracotomy mitral surgery is safe and can be done by most surgeons. Both methods have advantages and disadvantages. Our mitral operations are done through a 4-cm incision. We have found that with smaller incisions it becomes difficult to provide direct aortic root cardioplegia using the clamp. With true endoscopic robotic surgery, port-access balloons may provide the best avenue for cardiac arrest. Also, reoperations limit access to the aorta, and balloon occlusion seems preferable to avoid tissue dissection. Nevertheless, most surgeons can apply the clamp technique effectively. Despite the advantages of the transthoracic clamp, both methods can provide an effective less invasive approach for mitral valve surgery, and both can widening each surgeon's operative armamentarium.