Minimally invasive valve surgery is evolving. Different features of minimally invasive techniques make some of them more feasible and more easily adoptable than others. New specifically designed instruments are quintessence of safe surgery with improving operative outcomes and comfortable operator-oriented working conditions.1–4
To guarantee an adequate benefit from less surgical trauma, rapid recovery, and less postoperative discomfort, the procedure itself should be implemented with an adequate visualization of the surgical field and subsequent standard and well-known routines of the procedure.
Aortic cross-clamping unquestionably remains inevitable part for most of valve surgery procedures performed with cardiopulmonary bypass (CPB). The conventional aortic clamping instruments seem inapplicable for most of the minimally invasive single-access procedures, when the incision length limits the visualization field, procedure is implemented through a minimally required working space and absence of any motionless instruments, and devices in the working field is a major advantage for the operator as facilitates easier and safer manipulations during procedure.
Within this article, we aim to demonstrate our experience with a newly designed aortic cross-clamp (CardioVision MIC-Aortic Clamp, Cardiomedical GmbH, Langenhagen, Germany) provided with completely detachable clamping limb (jaws) remaining within thorax for the whole duration of the procedure.
The clamping device consists of three separate components by which the clamp is carried and delivered. These three components are aortic cross-clamp itself, clamp holder, and clamp screwer (Fig. 1A). Shanks of the clamp are curved down for easier placement.
The clamping branch of the instrument is mounted on the delivery shaft and is inserted through a single-access minithoracotomy in the second intercostal space for aortic and in third or fourth intercostal space for mitral and double mitral-tricuspid and mitral-aortic (only third intercostal space) valve procedures. The clamp is fixed with holder, and a screwdriver is inserted forward, over a pipe, until its tip attached to the slot head of the screw on the distal part of the clamping branch (Fig. 1B).
When assembled, the clamp is inserted through a minithoracotomy and applied on aorta with its jaws, thus having the rigid (straight) branch directed toward posterolateral aortic wall. Immobile shaft of the clamp is positioned through previously prepared transverse sinus, posterior to the ascending aorta. The screwdriver is gradually fastened until the aorta is effectively cross-clamped (see Supplemental Digital Content Video 1, http://links.lww.com/INNOV/A1). When complete aortic clamping is accomplished, the clamping component of the instrument is left inside the patient's chest (Fig. 2A, B). During placement, care is taken to prevent injury to the left atrial appendage and right pulmonary artery behind the aorta. The main pulmonary artery cannot be isolated for the ascending aorta in right minithoracotomy and can be partially involved into clamping by distal part of the cross-clamp jaws.
The unclamping procedure is implemented in the other way round manner: the holder is inserted into the thorax, the clamping branch is taken, and the screwer is inserted. Gradually, the screw is unfastened, and the aorta is unclamped (see Supplemental Digital Content Video 2, http://links.lww.com/INNOV/A2).
Procedure is accomplished in a routine fashion. An excellent visualization of the operative field was observed during minimally invasive procedures performed through a right single-access minithoracotomy. The valvular procedures were implemented without any modification of method itself, and no alteration to the standard valve repair/replacement technique, CPB and other routines was made. This clamp has provided very careful and secure occlusion without any aortic damage. Procedures were performed under direct vision, although we always use a video-assistance that serves as an important tool for educative and demonstrative reasons.
The CardioVision MIC-Aortic Clamp was used in a total number of 34 minimally invasive valve procedures (mean age, 58 ± 11 years). Operations consisted from mitral repair or replacement (n = 15), aortic valve replacement (n = 9), and double mitral-tricuspid (n = 7) and mitral-aortic (n = 3) performed via right single-access minithoracotomy. In all cases, a CPB was instituted by central aortic and peripheral femoral vein cannulation. No mortality and morbidity associated to procedure or aortic cross-clamping technique was encountered.
Several significant advances have been made recently in minimally invasive cardiac surgery to improve surgical outcomes, by minimizing the surgical trauma and trying to maintain the same or even better working conditions for the operating surgeon, as during conventional procedures. Minimally invasive techniques are evolving, and a learning curve is important to achieve an adequate confidence with the routine basics and special instrumentarium of these operations.
Being apart from the major manipulations during procedure, the presented aortic clamp permits an increased exposure and minimizes the risk of its unintentional dislodgment. A larger experience with the instrument and further studies would be necessary to clarify the possible pitfalls associated with instrument usage and following clinical risks. Newer less-invasive aortic clamping solutions could positively contribute to the modification of a current surgical armamentarium, thus facilitating the implementation of a minimally invasive procedure through an improvement of surgical technique and working comfort.
1.Chitwood WR Jr, Elbeery JR, Moran JF. Minimally invasive mitral valve repair using transthoracic aortic occlusion. Ann Thorac Surg.
2.Glauber M, Karimov JH, Farneti PA, et al. Minimally invasive mitral valve surgery via right minithoracotomy. Multimedia Man Cardiothorac Surg
. DOI: 10.1510/mmcts.2008.003350.
3.Marchetto G, D'Armini AM, Rinaldi M, Viganò M. Portaclamp in video-assisted minimally invasive cardiac surgery: surgical technique and preliminary clinical experience. Eur J Cardiothorac Surg.
4.Yozu R, Shin H, Mitsumaru A, et al. A new endo aortic occlusion balloon for limited access cardiac surgery: development and clinical evaluation. ASAIO J.