VALIDATION OF THE VIBe INTRAOPERATIVE BLEEDING SCALE IN LIVER SURGERY

Surgical hemostasis has become one of the fundamental principles for the advancement of surgery. The use of hemostatic agents is standard in many surgical specialties, with greater use in major surgeries. Inadequate hemostasis significantly increases the risk of perioperative morbidity and mortality, healthcare costs and the use of resources. The need for hemostasis has led to the development of various topical hemostatic agents.

Clinical studies that have analyzed the use of topical hemostats have not used standardized definitions or classifications to determine the severity of intraoperative bleeding, partly due to a lack of consensus on the definition of the severity of bleeding and partly due to the severity of bleeding. lack of requirements to do so. This has led many surgeons to an inadequate selection of hemostats for different bleeding situations, the results being inefficient. Using standardized criteria, the results of clinical studies can be compared to determine the effectiveness of hemostatic agents.

The FDA (Food and Drug Administration) requires the use of a bleeding severity scale validated in clinical studies investigating hemostatic agents. The VIBe (Validated Intraoperative Bleeding Scale) for intraoperative bleeding was developed in 2017.This scale has been validated by a large number of expert surgeons from all specialties, but in an animal model. However, it has not yet been clinically validated.

Liver surgery is one of the surgeries where intraoperative bleeding is more important. In Spain, around 5000 liver resections are performed annually, not including liver transplants. It is, therefore, a perfect framework to validate the applicability of the VIBe scale of severity of intraoperative bleeding.

In order to evaluate the viability of a prospective clinical study in liver surgery, a parallel project has been worked on based on the evaluation of the applicability of the VIBe scale, carried out by liver surgeons by reviewing the original video recordings described in the VIBe scale. Forty-seven surgeons were selected from 10 medium-high-volume liver surgery centers, all of them reference centers (same centers that will participate in the prospective study). 5 of the 10 hospitals perform liver transplants. These centers have a mean reference population of 922,506 ± 225,603 patients. The mean number of major hepatectomies per year is 23 ± 16, the number of minor hepatectomies 56 ± 24, and the number of liver transplants 40 ± 27. 40.5% of all hepatectomies are performed by a minimally invasive approach.

The 47 surgeons viewed 14 videos used by Lewis et al. for the validation of the original VIBe scale. 63.3% of the participating surgeons were men with a mean age of 41.6 years. 17% were unit / department heads and 83% were senior surgeons. The mean experience was 9.3 years, and the majority were experts (21.3%) or with advanced knowledge (53.2%) in minimally invasive surgery. Only 23.4% had prior knowledge of the VIBe scale, but all surgeons used hemostats in their daily clinical practice. The VIBe scale achieved a mean intraobserver agreement of 0.985 and an interobserver agreement of 0.929, neither of which was influenced by the experience of the surgeon or the volume of surgeries per year. The average rating for all videos was 67% correct, in line with the original validation. Most surgeons considered that the scale represented the range of severity of bleeding in their procedures (91%), relevant to assess intraoperative hemostasis in clinical studies (96%) and clinical practice (87.2%), useful in CMI (96%), and also to differentiate hemostatic agents (81%).

With these preliminary data, based on the video classification exercise, we can conclude that the VIBe scale is useful for the assessment of the severity of bleeding performed by liver surgeons. Therefore, an assessment of the severity of intraoperative bleeding using the scale in actual liver surgery is feasible. Our goal is to publish these results independently before starting the clinical observation record.

To evaluate the clinical applicability, a prospective registry of patients undergoing liver surgery has been designed in the 10 selected Spanish centers. Demographic and preoperative, intraoperative and postoperative data will be collected. Intraoperative bleeding will be measured according to the VIBe scale at two points of the surgical intervention: the maximum bleeding and at the end of the surgery. Data will be collected on the type of hemostatic or surgical strategy that has been carried out to correct bleeding (i.e. pressure, suture, coagulation, hemostatic, etc.) and other data related to bleeding (blood loss, units of blood transfused, etc.). Postoperative complications will be classified according to the Clavien-Dindo classification and the CCI (Comprehensive Complication Index). Major complications are defined as those with a Clavien-Dindo ≥ IIIa. The classification of liver failure and postoperative bleeding are defined following the International Study Group of Liver Liver Surgery (ISGLS) classifications. At the end of the registration a statistical analysis of the data will be performed to determine the applicability and usefulness of the VIBe scale in liver surgery, as well as to determine the relationship between the type of bleeding, the hemostatic measurements used, the success rate of the hemostatic measurements, and the bleeding-related complications.

Despite the extensive literature published on liver surgery, there is no scientific evidence that allows us to have validated scalds that quantify the severity of intraoperative bleeding and, consequently, select which is the best hemostatic procedure that is adapted to each case. All of this has repercussions on patient safety, increased postoperative morbidity and mortality, as well as the inappropriate use of healthcare resources and consequently increased costs.

This prospective multicenter study in national centers that perform Liver Surgery aims to evaluate and validate a scale that allows quantifying intraoperative bleeding in liver surgery.