Application of a novel surgical difficulty grading system during laparoscopic cholecystectomy

Abstract

Background: Prevention of bile duct injury and vasculo-biliary injury while performing laparoscopic cholecystectomy (LC) is an unsolved problem. Clarifying the surgical difficulty using intraoperative findings can greatly contribute to the pursuit of best practices for acute cholecystitis. In this study, multiple evaluators assessed surgical difficulty items in unedited videos and then constructed a proposed surgical difficulty grading. Methods:We previously assembled a library of typical video clips of the intraoperative findings for all LC surgical difficulty items in acute cholecystitis. Fiftyone experts on LC assessed unedited surgical videos. Inter-rater agreement was assessed by Fleiss's κ and Gwet's agreement coefficient (AC).Results: Except for one item ("edematous change"), κ or AC exceeded 0.5, so the typical videos were judged to be applicable. The conceivable surgical difficulty gradings were analyzed. According to the assessment of difficulty factors, we created a surgical difficulty grading system (agreement probability = 0.923, κ = 0.712, 90% CI: 0.587-0.837; AC 2 = 0.870, 90% CI: 0.768-0.972).

Clinical evaluation of a surgical difficulty score for laparoscopic cholecystectomy for acute cholecystitis proposed in the Tokyo Guidelines 2018

“…The TG18 difficulty score includes detailed grading of findings related to AC. The objectivity and universality of this difficulty score has been demonstrated by Asai et al 9 and furthermore, in our study, this difficulty score was shown to correlate appropriately with surgical outcomes. It therefore allows for comparisons among different institutions and studies and facilitates investigation of preoperative risk factors for difficult surgeries as well as the relationship between surgical difficulty and postoperative complications.…”

“…No patients had a difficulty score of 6 in this study. Each of the median, highest, and mean score were classified into three grades: grade A (zero to one point), grade B (two to four points), and grade C (five to six points) according to report by Asai et al 9 …”

“…As for this difficulty score in TG18, Asai et al 9 divided the highest score of 25 findings listed into three grades, and they proved its universality and objectivity as a difficulty score of LC for AC. However, they stated as a limitation of their study that only the highest score is evaluated and the total score of surgical difficulty items is not considered.…”

“…The distributions of the difficulty scores are shown in Table 4. The distributions of the median, maximum, and mean The association of surgical outcomes with each difficulty score was examined by the trend test according to the grading classification of Asai et al 9 The results of the Cochran-Armitage trend test for the difficulty score and the requirement of subtotal cholecystectomy are shown in Table 5. Higher difficulty scores were associated with a higher rate of conversion to subtotal cholecystectomy.…”

“…In this scoring system, 25 findings in five categories related to local inflammation and fibrosis assessed intraoperatively are scored on a 7-stage scale ranging from 0 to 6. 7,8 The universality and objectivity of this difficulty score as a measure of surgical difficulty of LC for AC has been proven by Asai et al 9 However, no reports have indicated whether this surgical difficulty score actually associate the surgical outcomes of LC for AC, and no specific scoring method is described in TG18.…”