Inflammation and indication: A novel approach to predict degree of difficulty during emergency laparoscopic cholecystectomy.

The indications for laparoscopic cholecystectomy (LC), unlike many other organs, range from intrinsic pathologies of the gallbladder like biliary colic to the extrinsic ones like stones in common bile duct (CBD) or gallstone pancreatitis. The operation itself can be ‘very easy’ or ‘extremely difficult’ requiring conversion to an open procedure.

Some studies have reported C-reactive protein (CRP) as a useful adjunct to other factors to improve the prediction of conversion of LC.[12] In 2016, after multivariate analysis, we proposed peak CRP value of >220 during acute admission as a single strong predictor of conversion of LC.[3] This finding is also supported by other recent studies.[45] We prefer to use the term ‘predicting the degree of difficulty (DoD)’ rather than ‘predicting conversion,’ as many difficult cholecystectomies can be completed laparoscopically by experienced surgeons.

Raw data from our previous study suggested correlation between indication of an operation and conversion. For example, LC for gallstone pancreatitis, unlike that for acute cholecystitis, is an ‘easy’ operation with virtually no need for conversion. These data also suggested that in patients with gallbladder pathology, the DoD increases with the rise of CRP. This difficulty culminated in conversion in 61.9% patients when CRP value crossed 220. Retrospective nature of this study precluded accurate correlation of degree of difficulty with a rising CRP. Therefore, a prospective data collection was commenced locally with the aim to:

Validate CRP as a single predicative factor for predicting DoD of LC when the operation is indicated for intrinsic gallbladder pathology

Examine the effect of rising CRP on DoD

Create a pathway based on indication and CRP to predict difficult LC.

Data were collected prospectively from April 2016 to July 2017 for all consecutive acute hospital admissions with gallstone-related diseases. Patients were included if they were over the age of 18 years, if LC was clinically indicated (either urgently or at later date) and if they were fit for an operation. Operations were performed either during index admission, semi-electively on the next available list or as delayed LC. Once included, patients were grouped based on their reason for admission: Group 1 – gallbladder disease (cholecystitis, biliary colic); Group 2 – CBD stones; Group 3 – gallstone pancreatitis.

Data were collected for demographics, peak CRP level during acute admission, indication for operation, timing of operation, length of operation, and the DoD (1–4, 4 being most difficult) using Nassar scoring system.[6]

Categorical data were compared using Chi-square test and continuous data (e.g., duration of operation) using t-test. Multivariate analysis to compare CRP with other predictive factors was not performed as it is already done in our previous study.[3]

During the study period, 163 patients (110 females, 53 males, average age 52.7 years) underwent LC. One patient from Group 1, with CRP <220, had type 1 Mirizzi's syndrome leading to CBD injury.

The number of patients in each group and proportion of them having DoD 4 are shown in Figure 1. Occurrence of DoD 4 in Group 1 patients was 79.3% when CRP was >220, as compared to 20.1% when CRP was <220 (P < 0.05). Conversion rates for the same groups were 51.7% and 11.7% (P < 0.05), respectively. Overall conversion rate in Group 1 was 22.64% (24/106) which is comparable to 22% in delayed and 19.7% in early intervention group in Cochrane review.[7] Similar trends were noticed in Group 2 but not Group 3. In Group 1, the average operating time was significantly longer in those with CRP >220 (117 vs 88 min). The effect of rising CRP on increasing DoD for Group 1 patients is shown in Figure 2 (R2= 0.41353).

Figure 1

Indication of cholecystectomy and degree of difficulty

Figure 2

Increase in degree of difficulty with rise in peak C-reactive protein

Previous literature used various factors such as body mass index and previous surgery for predicting conversion of LC. DoD in Nassar classification refers to difficulty in dissecting Calot's triangle only. In our opinion, this is the only clinically relevant difficulty that needs to be predicted preoperatively to prevent CBD injury.

A recent population-based study highlights high incidence of CBD injury rates in those converted (2%), compared to those completed laparoscopically (0.3%).[8] Strasberg's critical view of safety[9] is difficult to demonstrate in the first group of patients when CRP is >220 and preoperative prediction of DoD remains challenging. We feel that our simple ‘indication and inflammation’-based prediction would help experienced surgeons to get involved in both decision-making process and performing operations in this group of patients to reduce the complication rate.[10]

We acknowledge the limitation of smaller numbers in our study. However, the trends shown in this as well as our previous study support the significant role of ‘indication and inflammation’ in predicting difficult LC. A large multicentre study will be needed to prove its real value in reducing CBD injuries.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.