Validate the Difficulty Scoring System and Develop a Novel Scoring System for Laparoscopic and Robotic Liver Resections

Study Overview
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Brief Summary
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To validate the Iwate difficulty scoring system and Institut Mutualiste Montsouris (IMM) scoring system (Appendix 2) in both laparoscopic and robotic liver resections

Detailed Description
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Minimally-invasive liver resections (MILR) are increasingly conducted world-wide today. Several international consensus meetings were convened to enable the safe dissemination of laparoscopic and robotic liver resections. The Iwate difficulty scoring system (Appendix 1) was formulated in Japan to grade the difficulty of liver resections. This was to allow beginners to adopt a stepwise approach to safely perform MILR according to their experience and competency level. Although this system has been recently validated in a recent Japanese multicenter study, it has not been externally validated in a large cohort of patients. Thus far, it has only been validated in several small single center studies. Furthermore, its utility for robotic liver resections has not been well-studied.

Official Title
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Retrospective International Multicenter Study to Validate the Difficulty Scoring System and Develop a Novel Scoring System for Laparoscopic and Robotic Liver Resections

Conditions
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Liver Diseases

Intervention / Treatment
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* Procedure: Minimally Invasive Liver Resection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All consecutive patients operated at a single institution during a fixed period Most recent operation date allowed (up till December 31, 2020, to allow three months follow-up). All minimally invasive hepatectomy approaches can be included, including lap- assisted (hybrid), hand-assisted, robotic-assisted and pure laparoscopy. The data of all patients including those that had repeat liver resections, concomitant surgeries (e.g. colectomies, hilar lymph node dissection, enbloc resections) may be included Patients with no liver tumors such as recurrent pyogenic cholangitis/ gallbladder may be included The site of the lesion/ pathology will be considered as the tumor site, size will be considered less than 3 cm unless tumor invades the liver. Exclusion Criteria: • Patients < 18 years of age Patients with liver transplant living donor hepatectomies

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 79 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients who underwent MILR from January 1, 2000 to December 31, 2020<br>Hospital of patients who underwent MILR from January 1, 2000 to December 31, 2020. | Procedure: Minimally Invasive Liver Resection<br>* laparoscopic and robotic liver resections<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Iwate scores for laparoscopic and robotic liver resections | To validate the Iwate difficulty scoring system IMM scoring system in both laparoscopic .and robotic liver resections. The IWATA measures the difficulty index from 0 to 12. The IMM scoring is from code 1 to 11. | January 1, 2000 to December 31, 2020 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Propensity scores for robotic and laparoscopic liver resections | To perform a propensity score matching (including adjustment for difficulty) comparing robotic and laparoscopic liver resections. | January 1, 2000 to December 31, 2020 |