Patient Characteristics and Perioperative Outcomes
Between May 2013 and December 2019, 369 patients with rectal cancer underwent robotic-assisted surgery. OF the patients, 203 patients who met the including criteria were enrolled in this study. Of them, 35 had a history of PAS, whereas 168 did not. After PSM, 32 PAS and 96 non-PAS patients were included for analysis (Fig. 1). The baseline characteristics and perioperative outcomes of the patients before (n = 203) and after (n = 128) PSM are summarized in Table 1.
Before PSM, the between-group differences in sex (P = 0.006) and console time (P = 0.0394) were significant. Moreover, before PSM, the median console time was shorter in PAS patients than in non-PAS patients (167.5 vs. 187.5 minutes, P = 0.0394), but no such between-group difference in median operation times (275 min [PAS] vs. 300 [non-PAS] min, P = 0.0748). Moreover, age, tumor distance from anal verge, postoperative serum CEA level, ASA score, BMI, operative procedure, protective diverting colostomy, docking time, estimated blood loss, time of first flatus passage, time of resuming soft diet, postoperative hospital stay, and postoperative first day pain score did not differ significantly (all P > 0.05). After PSM, both the median console time became similar between the two groups [165 min (PAS) vs. 175 min (non-PAS), P = 0.4542] and median operation time [275 min (PAS) vs. 290 min (non-PAS), P = 0.5943)] became similar between the groups.
Pathological and Oncological Outcomes
Table 2 summarizes the pathological characteristics and oncological outcomes of the patients before (n = 203) and after (n = 128) PSM. Preoperative clinical staging demonstrated that most patients with LARC had T3 lesions: 27 (77.1%) PAS and 129 (76.8%) non-PAS patients, respectively. Even after PSM, most patients with LARC had T3 lesions: 25 (77.1%) PAS and 74 (77.1%) non-PAS, respectively. No significant differences were observed in terms of clinical T, N, and AJCC stages in PAS and non-PSA patients (all P > 0.05). Moreover, no significant differences were observed in terms of postoperative pathological and oncological outcomes (all P > 0.05). Furthermore, no significant differences were observed in terms of preoperative clinical staging, postoperative pathological outcomes, and oncological outcomes (all P > 0.05) after PSM.
After PSM, The median follow-up duration after primary treatment was 22.5 months (range: 8.4–74.6) and 30.5 (range: 6.2–87.1 months) months in PAS and non-PAS patients with stage I-III LARC, respectively. Postoperative relapse were experienced by 5 (17.9%) PAS and 14 (16.7%) non-PAS patients, respectively, including local recurrence in 1 (3.6%) PAS patient, and distant metastases in 4 (14.3%) PAS and 14 (16.7%) non-PAS patients. Moreover, after PSM, PAS and non-PAS patients demonstrated postoperative relapse rates were comparable in patients with and without PAS after PSM, including overall, local recurrence, and distant metastasis rates (all P > 0.05). Furthermore, 4 (12.5%) PAS and 11 (11.5%) non-PAS patients died during follow-up (P = 0.9377). In PAS and non-PAS patients with stage I-III LARC, the 3-year DFS rates were 81.6% and 78.0%, respectively (Fig. 2A, P = 0.8750). 3-year OS rates were 91.0% and 92.4%, respectively (Fig. 2B, P = 0.8709); 3-year locoregional recurrence-free survival rates were 93.3% and 100.0%, respectively (Fig. 2C, P = 0.0845); 3-year distant metastasis-free survival rates were 87.5% and 78.0%, respectively (Fig. 2D, P = 0.8016).
Postoperative Complications
Postoperative complications in our PAS and non-PAS patients are summarized in Table 3. Postoperative complications were observed in 7 (21.9%) PAS and 19 (19.8%) non-PAS patients after PSM (P = 0.0845), respectively; however, the difference was nonsignificant (P = 0.6010). Moreover, anastomosis leakage was observed in 0 (0.0%) PAS and 4 (4.2%) non-PAS patients after PSM. Ileus was observed in 0 (0.0%) PAS and 4 (4.2%) non-PAS patients after PSM. Anastomosis stenosis was observed in 3 (9.4%) PAS and 2 (2.1%) non-PAS patients after PSM. Based on the Clavien-Dindo classification system, all postoperative ileus, urinary complication, central venous catheter infection, neck cellulitis, sexual dysfunction, and pulmonary complications were of grade I and the patients demonstrated an uneventful recovery course after conservative treatment. Moreover, no 30-day hospital mortality occurred.