This retrospective comparative study analyzed the post-operative pain and QOL between TTS and CFS for AVR. Our findings indicate that TTS for AVR is associated with lower post-operative pain and higher QOL measures compared to CFS for AVR in the early post-operative period.

The advantages of minimally invasive TTS over CFS have been well documented in previous studies [9]. Minimally invasive TTS can reduce surgical trauma, blood loss, wound infection, postoperative pain, and hospital stay, as well as improve cosmetic results and patient satisfaction [10, 11]. Thoracoscopic surgery can also preserve the integrity of the chest wall and reduce postoperative pain and analgesic consumption. Moreover, TTS can provide a clear and magnified view of the operative field through a video camera, which may facilitate precise manipulation and suturing [12].

TTS also has some drawbacks and limitations. First, TTS requires a longer cardiopulmonary bypass time and aortic cross-clamp time than CFS, [13] which may increase the risk of ischemia-reperfusion injury and neurological complications [14]. Second, TTS requires specialized instruments and skills, as well as a steep learning curve for surgeons [15]. Third, complex aortic valve conditions, such as severe calcification of the aortic annulus or small aortic annulus diameter that necessitates annulus enlargement, may pose challenges for thoracoscopic AVR [13].

Therefore, careful patient selection and surgical experience are essential for successful TTS [16, 17].

In this study, we performed two-port thoracoscopic AVR for patients with aortic valve disease who met the inclusion and exclusion criteria. We found that TTS was feasible and safe in these patients. The operative time was similar between the two groups, indicating that thoracoscopic surgery did not prolong the overall duration of surgery. However, the cardiopulmonary bypass time and aortic cross-clamp time were significantly longer in the thoracoscopic group than in the sternotomy group. This was consistent with previous studies that reported longer cardiopulmonary bypass time and aortic cross-clamp time for thoracoscopic AVR compared to CFS [13, 18, 19]. TTS requires longer cardiopulmonary bypass and aortic cross-clamp times because of technical challenges. These include limited exposure, restricted mobility, lack of tactile feedback, and need for precise coordination. Improving surgical techniques and instruments may help to shorten these times. In this study, we utilized interrupted pledgeted mattress sutures for implantation of the bioprosthetic or mechanical valves. The sutures were tied down manually after knot pushing and securing with a surgical clip applier. We did not employ knot tying devices such as the Kor-Knot or sutureless valve technology in this series. Use of automated knot tying tools or rapid deployment valves may help shorten the cross clamp and cardiopulmonary bypass times compared to manual tying techniques. However, manual tying allows for fine control of valve orientation and seating during implantation. Further comparative studies are warranted to determine if knot tying devices or sutureless valves provide advantages over manual techniques for total thoracoscopic aortic valve replacement, especially with regards to facilitating reduced cross clamp times. Our center will be investigating these technologies in the future to potentially optimize our total thoracoscopic approach.

The main benefit of TTS was the reduction of postoperative pain. We found that the VAS scores were significantly lower in the TTS group than in the CFS group at all time points after surgery. This indicated that TTS caused less surgical trauma and inflammation than CFS. Moreover, TTS avoided sternal retraction and division, which may damage the intercostal nerves and cause chronic pain syndrome. The reduction of postoperative pain may have several positive effects on patient recovery and outcomes. First, less postoperative pain may improve pulmonary function and prevent respiratory complications [20]. Second, less postoperative pain may reduce analgesic consumption and its related side effects [21]. Third, less postoperative pain may enhance patient comfort and satisfaction [22]. The difference in VAS scores between the two groups was most prominent within 3 months after surgery, indicating that the pain-relieving benefits of TTS were greatest during the early recovery period. These results are supported by previous studies demonstrating less postoperative pain in TTS relative to CFS patients, especially in the first few months following surgery [13, 16].

Another benefit of thoracoscopic surgery was the improvement of QOL. We found that the QOL scores were significantly higher in the thoracoscopic group than in the sternotomy group up to 6 months after surgery. This indicated that thoracoscopic surgery had a positive impact on the physical and mental well-being of the patients. The QOL scores were measured by the SF-36 questionnaire, which covers eight domains of health status. We found that the thoracoscopic group had better scores than the sternotomy group in most domains, especially in physical functioning, role limitations due to physical problems, bodily pain, and general health. These domains reflect the ability of the patients to perform daily activities, cope with physical challenges, and enjoy life without pain or discomfort. The improvement of these domains may be related to the reduction of postoperative pain, faster recovery, and better cosmetic results after TTS. However, we also found that the QOL scores were similar between the two groups at 12 months after surgery. This suggested that the benefits of TTS on QOL were not sustained in the long term. This may be explained by the fact that QOL is influenced by many factors besides surgery, such as age, comorbidities, social support, and lifestyle [23]. Moreover, QOL may also depend on the type and durability of the prosthetic valve used for AVR [24]. Therefore, further studies with longer follow-up and larger sample size are needed to evaluate the long-term effects of TTS on QOL.

This study has several limitations that may affect the generalizability and validity of our findings. First, it is a retrospective, single-center study with a relatively small sample size. Second, we did not compare TTS with other minimally invasive approaches for AVR, such as TAVR or partial sternotomy. These approaches may have different advantages and disadvantages in terms of safety, efficacy, quality of life, and cost, which are important considerations when determining the most appropriate surgical option for patients. Therefore, further studies are needed to compare thoracoscopic surgery with TAVR or partial sternotomy. Third, a lack of randomization between surgical techniques and potential surgeon selection bias regarding operative approach limit the study. We also did not assess long-term outcomes, such as survival and valve durability, which are important considerations in AVR.