As the prevalence of acute cholecystitis increases with the increasing elderly population, we pay more attention both to the old patients with AC. One of the main problems concerning the role of PC is the lack of validated, well-established scoring systems to stratify the severity of patient disease states and different definitions are used to identify “high-risk patients”. The authors of the Tokyo guidelines suggested a staging system using mild, moderate and severe, depending upon the degree of local inflammation and the patients’ conditions[11–13]. However, a retrospective series failed to find any significant benefit from the application of the Tokyo guidelines. Amirthalingam et al. concluded that the Tokyo guidelines 2013 may be too restrictive for patients with moderate and severe acute cholecystitis, and more attention should be paid to patient comorbidities during clinical decision-making. Yacoub et al. tried to develop a score to stratify patients with gangrenous cholecystitis but did not pay much attention to the comorbidities of the patients; their score cannot be applied to patients who do not desire surgery. We propose the APACHE IV score as a good tool to stratify and compare elderly patients with AC in clinical trials, and our study results indicate that this is possible. For most hospitals, there are no conditions or data to establish their own evaluation criteria, therefore it is convenient and accurate to apply APACHE IV scoring in their clinical wards.
Although laparoscopic cholecystectomy is considered the gold standard treatment for patients with AC, it remains difficult to make definitive recommendations regarding treatment by PC or cholecystectomy in elderly or critically ill patients. A recent review reported a particularly detailed examination of 53 papers regarding cholecystostomy as an option in acute cholecystitis, and suggested that PC was beneficial in high-risk patient groups, predominantly as a bridging therapy, allowing safer elective cholecystectomy once the patient has recovered from the acute illness . Our data agree with this suggestion, as the procedure can stabilize the patient so that appropriate therapeutic planning can be achieved. There are reports that, in patients with acute cholecystitis who presented to the hospital ≥ 72 hours after symptom onset and did not respond to nonoperative treatment for 48 hours, PC with delayed laparoscopic cholecystectomy produced better outcomes and fewer complications than did emergency laparoscopic cholecystectomy. Our experience partly confirmed this argument. In this group of data, the number of patients with predicting high mortality in both the PC group and the cholecystectomy group is too small, and the comparison between the two surgical methods is not statistically accurate, so we did not make this comparison. More data are wanted to clarity this question.
In a randomized controlled trial by Hatzidakis, the efficacy of PC was compared with that of conservative management; the authors suggested that PC should not be performed as the first choice in patients with acute cholecystitis, since it did not produce lower mortality rates than did conservative treatment. They also suggested that PC should be appealing to patients not showing clinical improvement following 3 days of conservative treatment, as well as to critically ill intensive care unit patients . Their results were in harmony with ours. For patients in mild or moderate condition, we did not find PC superior to conservative treatment. One reason for the indistinguishability is that the death rates were very low; on the other hand, conservative treatment did have a good effect. We suggest more precise indications for PC with the estimated mortality rate more than 10%. Of these eligible patients, PC was associated with reduced mortality. Early recognition and intervention are required in these patients, because of the rapid progression of acute cholecystitis to gangrene and perforation. We believe our indications are more concise and suitable for clinical work.
In previous studies of the safety of PC, procedure-related complications were only about 6.25%, relatively low considering candidates are usually high-risk patients. In our study, we found procedure-related complications in elderly patients with AC were only 7.16%, comparable to those of previous reports.  Although urgent cholecystectomy (within 72 hours from symptom onset) has been proposed as a definitive treatment for symptomatic gallbladder disease,  routine cholecystectomy in an emergency setting can be challenging. Rather, gallbladder puncture is a better choice for surgeons with less experience. PC is a comparatively safe and effective procedure for the treatment of not only elderly high-risk patients with serious comorbidities but also for patients with contraindications for the general anesthesia required for cholecystectomy.
Our study has two major limitations. First, although this is the first external validation of the APACHE IV admission prognostic model in elderly patients with AC, it is a nonrandomized and retrospective study. Second, this research was done in China. Among the 597 patients, 480 (80.40%) received conservative managements rather that the surgical management that they should have had according to the international guidelines. This was mainly due to patients' unwillingness to operate and lack of experienced surgeons and this may have impacted on the patient prognosis. The study in itself has limitation in the external validity and its purpose is to compare PC to conservative treatment, excluding the patients who underwent cholecystectomy. Further studies will be required to elucidate this point.