A new clinical-ultrasound score to predict difficult videolaparocholecystectomies: A prospective study

Performance of ultrasound in the diagnosis of cholecystitis: not so (ultra)sound?

INTRODUCTION

Ultrasound has long been the radiological investigation of choice for right upper quadrant pain in the detection of gallstones and cholecystitis. However, previously reported sensitivity, specificity and other diagnostic metrics have varied widely and the underlying patient numbers have been small. We present robust and exhaustive diagnostic metrics based on a large series of 795 patients.

METHODS

All laparoscopic cholecystectomies at Portsmouth Hospitals University were prospectively logged between 2017 and 2020. Ultrasound findings, Nassar operative difficulty and histopathological findings were all collected in addition to patient biometrics.

RESULTS

In our large patient series, the sensitivity of ultrasound for cholecystitis was lower than previously reported at 75.7% for acute cholecystitis, 34.6% for chronic cholecystitis and 42.7% overall. Moreover, we show that sensitivity degrades with the time between ultrasound and cholecystectomy, falling below 50% at 140 days. Finally, we show that ultrasound strongly predicts the Nassar difficulty grade of cholecystectomy and that its ability to do so is greatest when the interval between ultrasound and cholecystectomy is less than 27 days.

CONCLUSIONS

We present robust diagnostic metrics for ultrasound in the diagnosis of cholecystitis. These should caution the clinician that ultrasound may miss a quarter of cases of acute cholecystitis and over half of all cases of cholecystitis. Conversely, the finding of a thickened gallbladder wall on ultrasound can predict a 'difficult cholecystectomy' and highlight the need for appropriate expertise and resources. Both this prediction and the diagnostic sensitivity are best if the ultrasound is done less than 27 days before cholecystectomy.

Reaching a consensus on the definition of "difficult" cholecystectomy among Spanish experts. A Delphi project. A qualitative study

BACKGROUND

Being able to predict preoperatively the difficulty of a cholecystectomy can increase safety and improve results. However, there is a need to reach a consensus on the definition of a cholecystectomy as "difficult". The aim of this study is to achieve a national expert consensus on this issue.

METHODS

A two-round Delphi study was performed. Based on the previous literature, history of biliary pathology, preoperative clinical, analytical, and radiological data, and intraoperative findings were selected as variables of interest and rated on a Likert scale. Inter-rater agreement was defined as "unanimous" when 100% of the participants gave an item the same rating on the Likert scale; as "consensus" when ≥80% agreed; as "majority" when the agreement was ≥70%. The delta of change between the two rounds was calculated.

RESULTS

After the two rounds, the criteria that reached "consensus" were bile duct injury (96.77%), non-evident anatomy (93.55%), Mirizzi syndrome (93.55%), severe inflammation of Calot's triangle (90.32%), conversion to laparotomy (87.10%), time since last acute cholecystitis (83.87%), scleroatrophic gallbladder (80.65%) and pericholecystic abscess (80.65%).

CONCLUSION

The ability to predict difficulty in cholecystectomy offers important advantages in terms of surgical safety. As a preliminary step, the items that define a surgical procedure as difficult should be established. Standardization of the criteria can provide scores to predict difficulty both preoperatively and intraoperatively, and thus allow the comparison of groups of similar difficulty.

Statistical models to preoperatively predict operative difficulty in laparoscopic cholecystectomy: A systematic review

BACKGROUND

Laparoscopic cholecystectomy operative difficulty is highly variable and influences outcomes. This systematic review analyzes the performance and clinical value of statistical models to preoperatively predict laparoscopic cholecystectomy operative difficulty.

METHODS

PRISMA guidelines were followed. PubMed, Embase, and the Cochrane Library were searched until June 2020. Primary studies developing or validating preoperative models predicting laparoscopic cholecystectomy operative difficulty in cohorts of >100 patients were included. Studies not reporting performance metrics or enough information for clinical implementation were excluded. Data were extracted according to CHARMS, and study quality was assessed using the PROBAST tool.

RESULTS

In total, 2,654 articles were identified, and 22 met eligibility criteria. Eighteen were model development, whereas 4 were validation studies. Eighteen studies were at high risk of bias. However, 11 studies showed low concern for applicability. Identified models predict 9 definitions of laparoscopic cholecystectomy operative difficulty, the most common being conversion to open surgery and operating time. The most validated models predict an intraoperative difficulty scale and procedures >90 minutes with an area under the curve of >0.70 and >0.76, respectively. Commonly used predictors include demographic variables such as age and gender (9/18 models) and ultrasound findings such as gallbladder wall thickness (11/18). Clinical implementation was never studied.

CONCLUSION

There is a longstanding interest in estimating laparoscopic cholecystectomy operative difficulty. Models to preoperatively predict laparoscopic cholecystectomy operative difficulty have generally good performance and seem applicable. However, an unambiguous definition of operative difficulty, validations, and clinical studies are needed to implement patients' stratification in laparoscopic cholecystectomy.

Preoperative prediction of difficult laparoscopic cholecystectomy based on diffusion-weighted magnetic resonance imaging

INTRODUCTION

Laparoscopic cholecystectomy is a common surgery with a varying difficulty level. Difficult laparoscopic cholecystectomy may be experienced by many surgeons. If difficult procedures are predicted preoperatively, surgeons may be able to plan the surgical approach and treatment accordingly. Studies have reported using blood and clinical imaging data to predict difficult cholecystectomy. However, to our knowledge, no studies have reported using MRI. The purpose of this study was to evaluate the usefulness of MRI as a predictor of difficult laparoscopic cholecystectomy.

METHODS

We retrospectively evaluated 25 patients with cholecystitis or biliary colic who had undergone diffusion-weighted whole-body imaging before laparoscopic cholecystectomy. The apparent diffusion coefficient value of the cystic duct was measured and its relationship with operative time and blood loss was examined to assess the capacity of diffuse-weighted whole-body imaging to predict difficult cholecystectomy. Further, we collected blood data and compared its usefulness as a predictor.

RESULTS

The apparent diffusion coefficient value of the cystic duct was significantly lower in patients with difficult laparoscopic cholecystectomy than in those with non-difficult procedures (P = .00007). White blood cell count and serum C-reactive protein level were significantly higher in patients with difficult cholecystectomy than in those with non-difficult procedures (P = .035, .030). In the receiver operating characteristic analysis, the apparent diffusion coefficient value was the best predictor.

CONCLUSION

Our results suggest that the apparent diffusion coefficient value of the cystic duct is a predictor of difficult laparoscopic cholecystectomy. In the future, it may be useful to study changes in coefficient values over time to determine optimal surgical timing.

Predicting the difficult laparoscopic cholecystectomy: development and validation of a pre-operative risk score using an objective operative difficulty grading system

BACKGROUND

The prediction of a difficult cholecystectomy has traditionally been based on certain pre-operative clinical and imaging factors. Most of the previous literature reported small patient cohorts and have not used an objective measure of operative difficulty. The aim of this study was to develop a pre-operative score to predict difficult cholecystectomy, as defined by a validated intra-operative difficulty grading scale.

METHOD

Two cohorts from prospectively maintained databases of patients who underwent laparoscopic cholecystectomy were analysed: the CholeS Study (8755 patients) and a single surgeon series (4089 patients). Factors potentially predictive of difficulty were correlated to the Nassar intra-operative difficulty scale. A multivariable binary logistic regression analysis was then used to identify factors that were independently associated with difficult laparoscopic cholecystectomy, defined as operative difficulty grades 3 to 5. The resulting model was then converted to a risk score, and validated on both internal and external datasets.

RESULT

Increasing age and ASA classification, male gender, diagnosis of CBD stone or cholecystitis, thick-walled gallbladders, CBD dilation, use of pre-operative ERCP and non-elective operations were found to be significant independent predictors of difficult cases. A risk score based on these factors returned an area under the ROC curve of 0.789 (95% CI 0.773-0.806, p < 0.001) on external validation, with 11.0% versus 80.0% of patients classified as low versus high risk having difficult surgeries.

CONCLUSION

We have developed and validated a pre-operative scoring system that uses easily available pre-operative variables to predict difficult laparoscopic cholecystectomies. This scoring system should assist in patient selection for day case surgery, optimising pre-operative surgical planning (e.g. allocation of the procedure to a suitably trained surgeon) and counselling patients during the consent process. The score could also be used to risk adjust outcomes in future research.