A total 211 of adult patients who underwent PT-GBD were selected from the hospital database from July 2017 to December 2018 in CSMUH and CCH. After exclusion of 10 patients who expired during index admission and 8 patients who accepted PT-GBD as a rescue treatment for bile duct cancer obstruction, we included 193 adult patients who underwent PT-GBD at index admission for acute cholecystitis. We further excluded 13 cases, who were alive because of lost follow up within 30 days after discharge. Among 180 patients selected for analysis, 59 patients underwent subsequent CCY and the other 121 patients didn’t accept CCY within 2 months before PT-GBD removal as a definite treatment. Eventually, there were 11 patients who underwent CCY because of RBEs or frequent biliary colic in the no CCY within 2 months group. The flow chart of this study is shown in Figure 1.
Subsequent CCY group vs. No CCY within 2 months group
The average age in the subsequent CCY group was 71.1 ± 14.6, which is significantly younger than those in the no CCY within 2 months group (p=0.022), with an average age of 76.4 ± 14.1 in. We could find that the proportion of sepsis, the proportion of underlying dementia, and CCI score (4.2 ± 2.2 vs. 5.4 ± 2.3, p < 0.001) were significantly higher in the no CCY within 2 months group. Other underlying diseases of the parameters of the CCI score were similar between the two groups. Regarding the status of CCY, only 11 patients (9.1 %) underwent CCY in the no subsequent CCY within 2 months group, while 94.9% patients underwent laparoscopic CCY under a subsequent CCY strategy in CCY within 2 months group. Only 81.8% of patients underwent laparoscopic CCY if CCY was chose as a rescue management in the no CCY within 2 months group when RBEs occurred. But the proportion of laparoscopic CCY did not meet statistical significance between these 2 groups. The detailed demographic data are shown in table 1.
There were 8 cases, which represent 13.6% of patients, that experienced RBEs once in the subsequent CCY group, while 39 cases (32.2%) experienced RBEs in the no CCY within 2 months group (1 RBE: 27 patients, 2 RBEs: 10 patients, 3 RBEs: 1 patient, 4 RBEs: 1 patients). The average number of RBE is higher in the no CCY within 2 months group comparing CCY within 2 months group (0.446 vs. 0.136 ). The overall mortality rate is 16.5% in the no CCY within 2 months group, and it is significantly higher than the overall mortality rate (5.1%) in the subsequent CCY group. But RBE-related mortality didn’t reach statistical significance between these two groups. The outcome comparisons are listed in table 2.
Decisive factors of RBE-free survival
We evaluate the true value of treatment for cholelithiasis using RBE-free survival, which demonstrated a survival curve free from RBEs and overall mortality. In univariate analysis, those age≥79 had 1.682 times the risk for RBEs or mortality (95% CI: 1.014-2.790, p=0.044), while gallbladder (GB) rupture in index admission had 2.665 times the risk (95% CI: 1.069-6.644, p=0.036) comparing to no GB rupture. The group with no CCY within 2 months had increased risk (HR:2.383, 95% CI: 1.244-4.564, p=0.009) in RBE-free survival compared to the subsequent CCY group. The detailed information about univariate analysis of disease severity, demographic data, CCI score, underlying disease condition, and CCY status is listed in table 3. After placing age (<79 vs. ≥ 79), GB rupture and subsequent CCY attempt and CCI score (≤8 vs >8) into multivariate analysis, only subsequent CCY maintained a significantly decreased risk of RBE-free survival, with 2.061 times the risk (CI: 1.063-3.998, p= 0.032) if subsequent CCY is not performed. Age (HR:1.477, 95% CI: 0.885-2.467, p=0.136), GB rupture (HR: 2.191, 95% CI: 0.873-5.501, p=0.095), and CCI score >8 (HR: 1.616, 95% CI: 0.763-3.425, p=0.210) had slightly increased risk in RBEs or mortality without statistical significance. Detailed multivariate analysis of RBE-free survival according to the clinical parameters is demonstrated in table 4.
RBE-free survival
RBE-free survival of patients who underwent PT-GBD due to acute cholecystitis was significantly better (p=0.007) if subsequent CCY was performed, with RBE-free survival being 81.9% in the next year and 75.0% at the end of the follow-up period, compared to 56.6% in the first year and 48.2% at the end of the follow-up period if subsequent CCY is not performed. The results are shown in Figure 2.