Benchmarking in Surgery

Defining Benchmark Outcome Values for Major Hepatectomy

Objective: To measure and define the best achievable outcome after major hepatectomy.

Background: No reference values are available on outcomes after major hepatectomies. Analysis in living liver donors, with safety as the highest priority, offers the opportunity to define outcome benchmarks as the best possible results.

Methods: Outcome analyses of 5202 hemi-hepatectomies from living donors (LDs) from 12 high-volume centers worldwide were performed for a 10-year period. Endpoints, calculated at discharge, 3 and 6 months postoperatively, included postoperative morbidity measured by the Clavien-Dindo classification, the Comprehensive Complication Index (CCI), and liver failure according to different definitions. Benchmark values were defined as the 75th percentile of median morbidity values to represent the best achievable results at 3 month postoperatively.

Results: Patients were young (34 ± [9] years), predominantly male (65%) and healthy. Surgery lasted 7 ± [2] hours; 2% needed blood transfusions. Mean hospital stay was 11.7± [5] days. 12% of patients developed at least 1 complication, of which 3.8% were major events (≥grade III, including 1 death), mostly related to biliary/bleeding events, and were twice higher after right hepatectomy. The incidence of postoperative liver failure was low. Within 3-month follow-up, benchmark values for overall complication were ≤31 %, for minor/major complications ≤23% and ≤9%, respectively, and a CCI ≤33 in LDs with complications. Centers having performed ≥100 hepatectomies had significantly lower rates for overall (10.2% vs 35.9%, P < 0.001) and major (3% vs 12.1%, P < 0.001) complications and overall CCI (2.1 vs 8.5, P < 0.001).

Conclusion: The thorough outcome analysis of healthy LDs may serve as a reference for evaluating surgical performance in patients undergoing major liver resection across centers and different patient populations. Further benchmark studies are needed to develop risk-adjusted comparisons of surgical outcomes.

Reference: Rössler F, Clavien PA et al. Defining Benchmarks for Major Liver Surgery: A multicenter Analysis of 5202 Living Liver Donors. Annals of Surgery 2016; 264: 492-500.

Defining Benchmark Outcome Values for Liver Transplantation

This multicentric study of 17 high-volume centers presents 12 benchmark values for liver transplantation. Those values, mostly targeting markers of morbidity, were gathered from 2024 „low risk“ cases, and may serve as reference to assess outcome of single or any groups of patients.

Objective: To propose benchmark outcome values in liver transplantation, serving as reference for assessing individual patients or any other patient groups.

Background: Best achievable results in liver transplantation, that is, benchmarks, are unknown. Consequently, outcome comparisons within or across centers over time remain speculative.

Methods: Out of 7492 liver transplantation performed in 17 international centers from 3 continents, we identified 2024 low risk adult cases with a laboratory model for end-stage liver disease score ≤20 points, a balance of risk score ≤9, and receiving a primary graft by donation after brain death. We chose clinically relevant endpoints covering intra- and postoperative course, with a focus on complications graded by severity including the complication comprehensive index (CCI). Respective benchmarks were derived from the median value in each center, and the 75 percentile was considered the benchmark cutoff.

Results: Benchmark cases represented 8% to 49% of cases per center. One-year patient-survival was 91.6% with 3.5% retransplantations. Eighty-two percent of patients developed at least 1 complication during 1-year follow-up. Biliary complications occurred in one-fifth of the patients up to 6 months after surgery. Benchmark cutoffs were ≤4 days for ICU stay, ≤18 days for hospital stay, ≤59% for patients with severe complications (≥ Grade III) and ≤42.1 for 1-year CCI. Comparisons with the next higher risk group (model for end stage liver disease 21-30) disclosed an increase in morbidity but within benchmark cutoffs for most, but not all indicators, while in patients receiving a second graft from 1 center (n = 50) outcome values were all outside of benchmark values.

Conclusion: Despite excellent 1-year survival, morbidity in benchmark cases remains high with half of patients developing severe complications during 1-year follow-up. Benchmark cutoffs targeting morbidity parameters offer a valid tool to assess higher risk groups.

Reference: Muller X, Clavien PA et al. Defining Benchmarks in Liver Transplantation: A Multicenter Outcome Analysis Determining Best Achievable Results. Annals Surgery 2018; 267: 419-425.

Defining Benchmark Outcome Values for Pancreatico-Duodenectomy

The aim of our new benchmark project is to define best possible outcomes in pancreatico-duodenectomy. This is a major surgical operation involving the removal of the head of the pancreas, the duodenum, the proximal jejunum, gallbladder, and part of the stomach. This operation is most often performed to remove cancerous or pre-cancerous tumors of the head of the pancreas. The goal of this study is to identify the best possible outcome (benchmarking), therefore data from high-volume centers in low risk patients will be analyzed. This study proposes outcome benchmarks for pancreatico-duodenectomy offering a novel tool to assess quality of care in different cohorts, centers and countries. Inferior outcomes for minimally invasive procedures call for caution before a wider promotion and center specific risk-profiles based on the proportion of benchmark procedures, rather than volume alone, might be relevant for future centralization policies.

Reference: Muller X, Clavien PA et al. Benchmarks in Pancreatic Surgery: A Novel Tool for Unbiased Outcome Comparisons. Annals of Surgery 2019; 270: 211-218.

Defining Benchmark Outcomes for ALPPS

This multicentric study from the ALPPS Registry presents 10 clinically relevant benchmark values and sets key reference values for ALPPS.

Objective: The aim of this study was to use the concept of benchmarking to establish robust and standardized outcome references after the procedure ALPPS (Associating Liver Partition and Portal Vein Ligation for Staged hepatectomy).

Background: The recently developed ALPPS procedure, aiming at removing primarily unresectable liver tumors, has been criticized for safety issues with high variations in the reported morbidity/mortality rates depending on patient, disease, technical characteristics, and center experience. No reference values for relevant outcome parameters are available.

Methods: Among 1036 patients registered in the international ALPPS registry, 120 (12%) were benchmark cases fulfilling 4 criteria: patients ≤67 years of age, with colorectal metastases, without simultaneous abdominal procedures, and centers having performed ≥30 cases. Benchmark values, defined as the 75th percentile of the median outcome parameters of the centers, were established for 10 clinically relevant domains.

Results: The benchmark values were completion of stage 2: ≥96%, postoperative liver failure (ISGLS-criteria) after stage 2: ≤5%, ICU stay after ALPPS stages 1 and 2: ≤1 and ≤2 days, respectively, interstage interval: ≤16 days, hospital stay after ALPPS stage 2: ≤10 days, rates of overall morbidity in combining both stage 1 and 2: ≤65% and for major complications (grade ≥3a): ≤38%, 90-day comprehensive complication index was ≤22, the 30-, 90-day, and 6-month mortality was ≤4%, ≤5%, and 6%, respectively, the overall 1-year, recurrence-free, liver-tumor-free, and extrahepatic disease-free survival was ≥86%, ≥50%, ≥57%, and ≥65%, respectively.

Conclusion: This benchmark analysis sets key reference values for ALPPS, indicating similar outcome as other types of major hepatectomies. Benchmark cutoffs offer valid tools not only for comparisons with other procedures, but also to assess higher risk groups of patients or different indications than colorectal metastases.

Reference: Raptis DA, Clavien PA. Defining Benchmark Outcomes for ALPPS. Ann Surg. 2019; 270: 835-841.

Surgery for Perihilar Cholangiocarcinoma – Novel Benchmark Values from 29 Expert Centers

Surgery for perihilar cholangiocarcinoma (PHC) is one of the highest risk procedures associated with perioperative mortality well over 15% in many countries. A few centers, however, have reported superior results, but conclusive comparisons have been notoriously difficult due to the presence of too many confounding factors. The availability of references values for a variety of outcome measures in PHC benchmark cases operated at expert centers would enable meaningful comparisons. The aim of this study was therefore to define in international high-volume centers benchmark values to enable unbiased comparisons within or across centers, and over times, or even with alternative approaches.

Reference: Accepted for presentation at the European Surgical Association (ESA) Meeting, May 13-15, 2021, in Cologne, Germany.