Recommendations for Laparoscopic Liver Resection
Recommendations for Laparoscopic Liver Resection
As per GRADE, comparators were selected pre hoc to evaluate OLRs and LLRs (Table 2). For some outcomes, the jury sought to determine if the evidence indicated that the results of LLR were clinically equal or at least not inferior to OLR (Table 2). For other outcomes, the jury evaluated whether the outcome after LLR was superior to OLR (Table 2). In the case of postoperative complications, the jury evaluated evidence for equality or superiority depending on the complication. Some complications like wound complications and pulmonary complications might be expected to be decreased by LLR (superiority of laparoscopic surgery) while others such as bile leaks are potentially greater and needed to be evaluated for equality. The list of comparators was accepted by the experts and the jury before the conference. The jury opinion of the relative importance of the comparators was determined before the meeting using a utility scale of 1 to 10. Scores were highest for postoperative mortality, complications, and margin negativity.
Rating of Quality of Evidence by GRADE. GRADE rates quality of evidence by a 2-step process. First, the study is given a preliminary rating based on methodology used. RCTs are given a HIGH rating; observational studies, such as cohort and case control studies, receive a LOW rating; and case series a VERY LOW rating. In the second step, the studies are examined in detail to determine whether the rating should be moved up or down on the basis of 7 factors, which gauge the evidence by criteria other than study type. Three of these permit raising the rating of a study (see below).
All available studies on LLR are observational studies—cohort studies, case series, or case reports. There are no published RCTs. According to GRADE, the quality rating of evidence in such studies is LOW. The jury determined whether any studies fulfilled criteria for raising or decreasing the rating. While there are 3 criteria for doing so, the one that was applicable in some of the available studies is "large treatment effect." A treatment effect of at least 50% permitted elevation of the rating from LOW to MODERATE. Because the studies were all observational, the criteria available in "MINORS," a validated method for rating surgical observational trials, were also used qualitatively to examine study quality. Note that the term "MINORS" is an acronym unrelated to the term "MINOR" used in this paper in reference to the extent of a liver resection.
Determination of Strength of Recommendation. The jury made 2 types of recommendations: Type A and Type B. Type A are based on (1) the quality of the body of evidence, (2) the benefit/risk ratio, (3) the benefit/cost ratio, and (4) the preferences and values of patients. Type A recommendations may be STRONG, WEAK, or NONE; the jury preferred the term MODERATE to WEAK. Type B are recommendations for future steps that would improve the level of evidence for the comparator. The strength is based on a judgment of the prioritization of the effort that is required: Type B recommendations may be STRONG or MODERATE.
MINOR and MAJOR Laparoscopic Resections. The classical definition was used. A MINOR resection is one in which 2 or fewer Couinaud segments are removed. A MAJOR resection is one in which 3 or more segments are removed. In actuality, most laparoscopic MINOR resections reported in the literature are left lateral sectionectomies or resections of segments 2, 3, 4b, 5, and 6, that is, mainly the anterior and inferior segments. The findings and recommendations of the jury under the term MINOR are based on this literature and therefore those types of resections and not more difficult resections involving posterior-superior segments.
Fortunately, the grading of complexity/difficulty of both OLRs and LLRs is in evolution. Currently, experts rate the complexity of various open 2-segment resections, that is, left lateral sectionectomy, right posterior sectionectomy, and right anterior sectionectomy very differently. In fact, this was recognized in the Louisville consensus conference in which it was concluded that laparoscopic resections of posterior superior segments should be considered to be "major" resections. For the purposes of this report the important issue is that it be clear to the reader how the terms were used by the jury.
The stage of development of the various procedures, that is, minor LLR, major LLR, live donor LLR, and robotic LLR was categorized using the Balliol classification of IDEAL. Also taken into account were the conclusions and recommendations of the Belmont report in regard to oversight of innovative procedures. These procedures fell into 1 of 3 categories: IDEAL stage 2a—"development in progress"; IDEAL stage 2b—"Exploration" stage; and IDEAL stage 3—"Assessment" phase. The first (IDEAL stage 2a—"development in progress) is the earliest phase of development of the three. Procedures in this category have the highest degree of risk due to novelty. Assignment to this category indicates the need for institutional ethical approval to perform the procedure as well as a reporting registry. The third (IDEAL stage 3—"Assessment" phase) covers procedures that have become standard practice. Risk due to novelty is low, but continuing assessment of outcomes is encouraged especially if high-level studies are lacking. IDEAL stage 2b is intermediate to the other 2 stages and is a stage in which considerable preliminary data supporting the safety of the procedure are present but in which it is judged that there is still risk associated with novelty. Such procedures should continue to be introduced in a cautious manner. The term "cautious" indicates first that surgeons undertaking these procedures are experienced both in liver surgery and advanced laparoscopy and second that outcomes are evaluated in registries and by RCTs where appropriate. An example of this is the National Surgical Quality Improvement Program registry in which serious morbidity and mortality of both open and laparoscopic procedures are recorded and reported. Finally implicit in IDEAL 2b is that the patient should be provided with information regarding the status of the procedure namely that (a) the procedure is an innovative procedure which has not yet become standard practice, (b) that as an innovative procedure it may have unknown risks, and (c) that the procedure should be performed only by those who have expertise in advanced laparoscopic techniques and major open liver surgery. Again it should be noted that the jury used IDEAL as a guide but also used other sources such as the Belmont report in framing its recommendations regarding oversight of procedures.
Background
Definition and Rating of Comparators
As per GRADE, comparators were selected pre hoc to evaluate OLRs and LLRs (Table 2). For some outcomes, the jury sought to determine if the evidence indicated that the results of LLR were clinically equal or at least not inferior to OLR (Table 2). For other outcomes, the jury evaluated whether the outcome after LLR was superior to OLR (Table 2). In the case of postoperative complications, the jury evaluated evidence for equality or superiority depending on the complication. Some complications like wound complications and pulmonary complications might be expected to be decreased by LLR (superiority of laparoscopic surgery) while others such as bile leaks are potentially greater and needed to be evaluated for equality. The list of comparators was accepted by the experts and the jury before the conference. The jury opinion of the relative importance of the comparators was determined before the meeting using a utility scale of 1 to 10. Scores were highest for postoperative mortality, complications, and margin negativity.
Rating of Quality of Evidence by GRADE. GRADE rates quality of evidence by a 2-step process. First, the study is given a preliminary rating based on methodology used. RCTs are given a HIGH rating; observational studies, such as cohort and case control studies, receive a LOW rating; and case series a VERY LOW rating. In the second step, the studies are examined in detail to determine whether the rating should be moved up or down on the basis of 7 factors, which gauge the evidence by criteria other than study type. Three of these permit raising the rating of a study (see below).
All available studies on LLR are observational studies—cohort studies, case series, or case reports. There are no published RCTs. According to GRADE, the quality rating of evidence in such studies is LOW. The jury determined whether any studies fulfilled criteria for raising or decreasing the rating. While there are 3 criteria for doing so, the one that was applicable in some of the available studies is "large treatment effect." A treatment effect of at least 50% permitted elevation of the rating from LOW to MODERATE. Because the studies were all observational, the criteria available in "MINORS," a validated method for rating surgical observational trials, were also used qualitatively to examine study quality. Note that the term "MINORS" is an acronym unrelated to the term "MINOR" used in this paper in reference to the extent of a liver resection.
Determination of Strength of Recommendation. The jury made 2 types of recommendations: Type A and Type B. Type A are based on (1) the quality of the body of evidence, (2) the benefit/risk ratio, (3) the benefit/cost ratio, and (4) the preferences and values of patients. Type A recommendations may be STRONG, WEAK, or NONE; the jury preferred the term MODERATE to WEAK. Type B are recommendations for future steps that would improve the level of evidence for the comparator. The strength is based on a judgment of the prioritization of the effort that is required: Type B recommendations may be STRONG or MODERATE.
MINOR and MAJOR Laparoscopic Resections. The classical definition was used. A MINOR resection is one in which 2 or fewer Couinaud segments are removed. A MAJOR resection is one in which 3 or more segments are removed. In actuality, most laparoscopic MINOR resections reported in the literature are left lateral sectionectomies or resections of segments 2, 3, 4b, 5, and 6, that is, mainly the anterior and inferior segments. The findings and recommendations of the jury under the term MINOR are based on this literature and therefore those types of resections and not more difficult resections involving posterior-superior segments.
Fortunately, the grading of complexity/difficulty of both OLRs and LLRs is in evolution. Currently, experts rate the complexity of various open 2-segment resections, that is, left lateral sectionectomy, right posterior sectionectomy, and right anterior sectionectomy very differently. In fact, this was recognized in the Louisville consensus conference in which it was concluded that laparoscopic resections of posterior superior segments should be considered to be "major" resections. For the purposes of this report the important issue is that it be clear to the reader how the terms were used by the jury.
Stage of Development According to the Balliol Classification of IDEAL
The stage of development of the various procedures, that is, minor LLR, major LLR, live donor LLR, and robotic LLR was categorized using the Balliol classification of IDEAL. Also taken into account were the conclusions and recommendations of the Belmont report in regard to oversight of innovative procedures. These procedures fell into 1 of 3 categories: IDEAL stage 2a—"development in progress"; IDEAL stage 2b—"Exploration" stage; and IDEAL stage 3—"Assessment" phase. The first (IDEAL stage 2a—"development in progress) is the earliest phase of development of the three. Procedures in this category have the highest degree of risk due to novelty. Assignment to this category indicates the need for institutional ethical approval to perform the procedure as well as a reporting registry. The third (IDEAL stage 3—"Assessment" phase) covers procedures that have become standard practice. Risk due to novelty is low, but continuing assessment of outcomes is encouraged especially if high-level studies are lacking. IDEAL stage 2b is intermediate to the other 2 stages and is a stage in which considerable preliminary data supporting the safety of the procedure are present but in which it is judged that there is still risk associated with novelty. Such procedures should continue to be introduced in a cautious manner. The term "cautious" indicates first that surgeons undertaking these procedures are experienced both in liver surgery and advanced laparoscopy and second that outcomes are evaluated in registries and by RCTs where appropriate. An example of this is the National Surgical Quality Improvement Program registry in which serious morbidity and mortality of both open and laparoscopic procedures are recorded and reported. Finally implicit in IDEAL 2b is that the patient should be provided with information regarding the status of the procedure namely that (a) the procedure is an innovative procedure which has not yet become standard practice, (b) that as an innovative procedure it may have unknown risks, and (c) that the procedure should be performed only by those who have expertise in advanced laparoscopic techniques and major open liver surgery. Again it should be noted that the jury used IDEAL as a guide but also used other sources such as the Belmont report in framing its recommendations regarding oversight of procedures.
Source...