Surgery is generally accepted as a major treatment option for the patients with early-stage lung cancer(3), containing older people(14). The patients aged ≥ 75 years have been eliminated in most clinical studies on surgical treatments for lung cancer when selecting patients. However, with the advent of the aging age, more lung cancer patients (≥ 75 years) in all stages appeared to be poorer adherence to treatment than younger patients and age seemed to be the most important factor on therapy decision for lung cancer patients(9). Advanced grade of Adult Comorbidity Evaluation-27 index that was used to assess preoperative comorbidities has proven a significantly poor prognostic factor for lung cancer patients (≥ 75 years) undergoing surgery(10). Recently, increasing attention has been raised on the surgical option for lung cancer patients aged ≥ 75 years. This study was conducted to compare perioperative outcomes between uniportal and three-port VATS for lung cancer patients aged ≥ 75 years. The study found no significant differences between uniportal and three-port VATS in perioperative outcomes in WC and LC, except uniportal LC was associated with significantly lower intraoperative blood loss (P < 0.05).
With the purpose of minimal incision trauma, uniportal VATS has been introduced in the application of VATS recently(15). Previous research has shown uniportal VATS lobectomy was superior with regard to significantly less intraoperative blood loss for the patients whose mean age ≤ 65 years(5, 16). In this study for the elderly aged ≥ 75 years, intraoperative blood loss was significantly lower in uniportal than three-port VATS in LC (P < 0.05) and relatively lower in uniportal than three-port VATS in WC (P = 0.05). There are some mainly possible reasons to explain these results as follows. First, the single port made in the intercostal space would decrease the injury of the muscle and vessels around the incision to reduce blood loss. Second, using a soft incision protector can lower intraoperative bleeding from the incision. Finally, the insertion of all instruments and the camera through one port can provide a direct view that is more similar to that in thoracotomy, with the advantage of exact resection and avoidance of accidental damage. These results might suggest the safety of uniportal VATS in reducing bleeding during the surgery and its applicability in treating older lung cancer patients aged ≥ 75 years.
The rate of postoperative complications is also an important aspect in evaluating the safety of surgery, especially in the elderly. Dai et al.(17) carried out a prospective study finding that postoperative complication rates were similar between uniportal and three-port VATS lobectomy. A retrospective study conducted by Ji et al.(18) showed there was no significant difference in postoperative complication rate between uniportal and three-port VATS lobectomy and anatomic segmentectomy. In detail, the mean age of the enrolled patients in the two previous studies above were ≤ 60 and ≤ 65 years respectively. For lung cancer patients (≥ 75 years), the present study showed rates of postoperative total complications or each postoperative complication listed in the Tables 3 and 4 did not differ significantly between uniportal and three-port VATS in WC and LC. These data showed uniportal VATS would not raise the incidence of postoperative complications although cardiopulmonary reserve and physical function are generally declining with aging, which indicated the safety of uniportal VATS for the elderly as well.
Mediastinal lymph node dissection plays a significant role in staging accuracy and long-term survival. Theoretically, nodal dissection by uniportal VATS would be limited due to instrument interference caused by the insertion of all instruments through the same port. Recently, two studies reported by Shen et al.(19) and Liu et al.(20) have demonstrated the total number of lymph nodes dissected via uniportal VATS was similar to that via three-port VATS in lobectomy. Meanwhile, Liu et al.(20) also found no significant difference in the stations of lymph nodes dissected between uniportal and three-port VATS lobectomy. In this study for lung cancer patients aged ≥ 75 years, no significant differences were found in the number and stations of lymph nodes dissected between uniportal and three-port VATS in WC and LC. These data demonstrated uniportal VATS could reach comparable outcomes of nodal dissection compared to three-port VATS, which also provided support to the feasibility of uniportal VATS for lung cancer patients aged ≥ 75 years. A possible reason for these data might be that suitable placement of the instruments and the camera during uniportal VATS could reduce instrument interference and present an exposed view to remove the target lymph node through the limited space of the single port.
Shortened postoperative length of hospital stay is an important index presenting accelerated postoperative recovery. The data in this study for lung cancer patients (≥ 75 years) showed that postoperative hospital duration was similar between uniportal and three-port VATS in WC and LC. However, the yields in two previous studies which both analyzed lung cancer patients aged ≤ 75 years showed postoperative hospital stay was shorter in uniportal VATS. The two previous studies are as follows. Xu et al.(16) conducted a prospective study finding a significantly shorter postoperative admission stay in uniportal VATS lobectomy. In another study published by Lee et al.(21), postoperative length of stay was significantly shorter in uniportal VATS segmentectomy. The advantage of uniportal VATS in reducing postoperative hospital stay might not be revealed when treating older lung cancer patients, probably because the rise in comorbidities and the decline in functional condition as aging would delay postoperative recovery. In general, these results indicated that uniportal VATS was a effective surgery that would not lengthen postoperative hospital duration to slow postoperative recovery for lung cancer patients aged ≥ 75 years.
Postoperative pain relief would also present accelerated postoperative recovery, benefiting facilitating coughing and expectorating. Uniportal VATS would cause lower postoperative pain for lung cancer patients(5), as well as older patients potentially. The main explanation for this consideration may be that the single port design minimizes the damage to nerve and muscle around the incision, and using a soft incision protector reduces repeating press and extrusion due to the insertion of all instruments through the same port, relieving postoperative pain. However, as aging, poorer pain tolerance and more postoperative analgesia may obscure the advantages of uniportal VATS in relieving postoperative pain for older patients. Postoperative pain control in older lung cancer patients undergoing uniportal VATS is an essential issue for future research.
This study has several limitations as follow. First, this study was a retrospective study potentially resulting in analysis and selection bias, although strict inclusion and exclusion criteria were applied. Second, the size of this study were relatively small probably because lung cancer patients (≥ 75 years) are related to poorer adherence to treatment. Third, the patients in the study were collected in a single center, although this center has been a high-volume center for thoracic surgery. Thus, a multi-institution, randomized, controlled trial with larger patients is suggested in future research.