To construct a risk prediction model for chronic post-surgical pain (CPSP) after anorectal surgery based on traditional Chinese medicine (TCM) syndrome types.

A retrospective selection was made of 460 patients who underwent anorectal surgery from January 2022 to June 2024. The clinical baseline data and TCM syndrome types of the patients were collected and summarized. The patients were divided into two groups based on whether CPSP occurred: the CPSP group (76 cases) and the non-CPSP group (384 cases). Univariate and multivariate Logistic regression analyses were used to screen for independent risk factors of CPSP, and the predictive efficacy of each index and the combined model was evaluated by drawing the receiver operating characteristic (ROC) curve.

The total incidence of CPSP after surgery in this study was 16.52% (76/460). Among CPSP patients, those with mild, moderate and severe pain accounted for 42.11% (32/76), 39.47% (30/76) and 18.42% (14/76), respectively. The frequency of pain was mainly occasional (52.63%) and frequent (36.84%). The nature of pain was commonly distending pain (36.84%) and stabbing pain (31.58%). Univariate analysis showed that the visual analogue scale (VAS) pain score 24 hours after surgery, operation duration, intraoperative blood loss, postoperative analgesic pump usage rate, preoperative Hamilton Anxiety Scale (HAMD), the Pain Catastrophizing Scale (PCS) and the Pittsburgh Sleep Quality Index (PSQI) scores in the CPSP group were all higher than those in the non-CPSP group (all P<0.05), and the proportion of qi stagnation and blood stasis syndrome was also higher (P<0.001). Correlation analysis showed that the occurrence of CPSP after surgery was significantly positively correlated with the VAS pain score 24 hours after surgery, the operation duration, the preoperative Hamilton Depression Scale (HAMD) score, PCS, PSQI scores, the use of the postoperative analgesic pump, and the syndrome type of qi stagnation and blood stasis (all P<0.05). Multivariate Logistic regression confirmed that the VAS pain score 24 hours after surgery, operation duration, HAMD score, PCS score, PSQI score and qi stagnation and blood stasis syndrome were all independent risk factors for CPSP (all P<0.001). ROC analysis indicated that the AUC of the combined prediction model reached 0.948, the sensitivity was 0.855, and the specificity was 0.883. The prediction efficacy was significantly better than that of each individual indicator (all P<0.05).

The risk prediction model for chronic pain after anorectal surgery constructed based on TCM syndrome types has a high predictive efficiency. Among them, the syndrome type of qi stagnation and blood stasis and the VAS pain score 24 hours after surgery are all independent risk factors, which can provide a reference basis for the early clinical identification and intervention of CPSP.