Patients and settings
Traditional minimally invasive approaches for aortic valve replacement (AVR) have not necessarily shown cosmetic superiority over standard median sternotomy. We have developed a minimally invasive technique for isolated AVR through a lateral thoracotomy via a small right axillary skin incision, and have evaluated its initial results.
Between May 2012 and April 2014, all patients for whom isolated, first-time AVR was indicated were considered as potential candidates for trans-axillary aortic valve replacement (TAX-AVR). Patients with advanced atherosclerosis or very poor cardiac function were excluded. As a result, 54 patients were enrolled. The mean age was 71.9 (range, 37-88) years, of which 33 (61.1%) were female. Twenty-three patients had senile aortic stenosis as the predominant lesion in this patient group, followed by degeneration in 15, bicuspid valve in 14, and rheumatic lesion in 2.
The surgical technique has been previously reported in detail (1). In brief, the right thorax was opened via a small, vertical right axillary skin incision and a third or fourth intercostal thoracotomy similarly to that performed in lung surgery. Cardio-pulmonary bypass was established through the right femoral artery and vein. The ascending aorta was clamped with Cosgrove’s flex-clamp. A variable angle endoscope (EndoCAMeleon, Karl Storz, Tuttlingen, Germany) was used to observe the aortic valve and suture line. An ultrasonic aspirator was used to remove the calcified aortic valve. All sutures, including those for prosthetic valve seating, were tied down with the aid of a knot pusher (Valve Gate 34-7495, Geister, Germany). Other minimally invasive long shafted instruments were also utilized.
Data collection and statistical analysis
Data were collected prospectively, and all patients were completely followed up. No control group was established, and only descriptive statistical data were presented.
Results are shown in Table 1. As concomitant procedures, annular patch enlargement was performed in three patients, mitral valve replacement in one, and mitral valve repair through independent left atriotomy in one. The length of skin incision was 6 cm for isolated AVR, and 8 cm for a double valve procedure. All patients received a bioprosthesis. The average size of the valve implanted was 22 mm, which was sufficient for an average body surface area (BSA) of 1.50 m2. No case was converted to sternotomy. Forty-nine patients left the intensive care unit (ICU) within 24 hours. Major brain infarction that resulted in left hemiplegia occurred in one 80-year-old male. This patient also needed prolonged mechanical ventilation, and a prolonged stay ICU. There were no cases of in-hospital mortality. As for other morbidities, low output syndrome, re-exploration for bleeding, wound infection, renal insufficiency, leg ischemia, or perivalvular leakage did not occur. Prolonged ventilation was required in one case as mentioned above. Between 1 and 24 months of follow-up (mean 18.8 months), all patients were alive, and no valve-related complications were observed.
Axillary incision is a popular technique in thoracic surgery, as this approach offers multiple advantages including cosmetic superiority, and facilitates direct access to the rib-cage by cutting only skin and subcutaneous fat. Some surgeons have adopted this approach for congenital or mitral valve surgery (2,3). In this approach, the ascending aorta is relatively distant compared with fore-chest thoracotomy or partial sternotomy. However, some distance from the access window to the target organ and a wide intra-thoracic space act favorably as a working space when using endoscopic assistance. Leftward deviation of the ascending aorta against the sternum was observed in some patients, but had little effect on the procedure, as opposed to a fore-chest thoracotomy.
All sutures were tied down using a knot pusher, and consequently TAX-AVR was time-consuming. This could be compensated for by using sutureless valves in the future. In addition, a right axillary approach could enable a totally endoscopic AVR, as adequate distance from the access port to the target organ act favorably in endo-surgery.
This is a single center experience with a limited number of patients, and most cases were performed by a single surgeon (T.I.) without a control group. Therefore, comparison with other minimally invasive approaches or with median sternotomy in terms of safety and risk of major complications is necessary.
The largest BSA of the patient in this series was only 1.86 m2, and as such this procedure may be difficult in extremely large or obese patients. Major stroke occurred in an elderly patient even though the preoperative screening computed tomography (CT) arteriogram showed little atherosclerosis. This procedure may carry a potential risk of stroke associated with retrograde perfusion through the femoral artery. Therefore, selection of elderly patients should be approached with caution. In summary, AVR performed via a cosmetically-advantageous right axillary small thoracotomy was possible with a reasonable technical demand.
Disclosure: The authors declare no conflict of interest.
- Ito T, Maekawa A, Hoshino S, et al. Right infraaxillary thoracotomy for minimally invasive aortic valve replacement. Ann Thorac Surg 2013;96:715-7. [PubMed]
- Kaneda T, Nishino T, Saga T, et al. Small right vertical infra-axillary incision for minimally invasive port-access cardiac surgery: a moving window method. Interact Cardiovasc Thorac Surg 2013;16:544-6. [PubMed]
- Wang D, Wang Q, Yang X, et al. Mitral valve replacement through a minimal right vertical infra-axillary thoracotomy versus standard median sternotomy. Ann Thorac Surg 2009;87:704-8. [PubMed]