Laparoscopic versus open right hepatectomy for colorectal liver metastases after portal vein embolization: international multicentre study.

BACKGROUND: Laparoscopic liver surgery is increasingly used for more challenging procedures. The aim of this study was to assess the feasibility and oncological safety of laparoscopic right hepatectomy for colorectal liver metastases after portal vein embolization. METHODS: This was an international retrospective multicentre study of patients with colorectal liver metastases who underwent open or laparoscopic right and extended right hepatectomy after portal vein embolization between 2004 and 2020. The perioperative and oncological outcomes for patients who underwent laparoscopic and open approaches were compared using propensity score matching. RESULTS: Of 338 patients, 84 patients underwent a laparoscopic procedure and 254 patients underwent an open procedure. Patients in the laparoscopic group less often underwent extended right hepatectomy (18% versus 34.6% (P = 0.004)), procedures in the setting of a two-stage hepatectomy (42% versus 65% (P < 0.001)), and major concurrent procedures (4% versus 16.1% (P = 0.003)). After propensity score matching, 78 patients remained in each group. The laparoscopic approach was associated with longer operating and Pringle times (330 versus 258.5 min (P < 0.001) and 65 versus 30 min (P = 0.001) respectively) and a shorter length of stay (7 versus 8 days (P = 0.011)). The R0 resection rate was not different (71% for the laparoscopic approach versus 60% for the open approach (P = 0.230)). The median disease-free survival was 12 (95% c.i. 10 to 20) months for the laparoscopic approach versus 20 (95% c.i. 13 to 31) months for the open approach (P = 0.145). The median overall survival was 28 (95% c.i. 22 to 48) months for the laparoscopic approach versus 42 (95% c.i. 35 to 52) months for the open approach (P = 0.614). CONCLUSION: The advantages of a laparoscopic over an open approach for (extended) right hepatectomy for colorectal liver metastases after portal vein embolization are limited.

Is prolonged operative time associated with postoperative complications in liver surgery? An international multicentre cohort study of 5424 patients.

BACKGROUND: The relation between operative time and postoperative complications in liver surgery is unclear. The aim of this study is to assess the impact of operative time on the development of postoperative complications in patients who underwent minimally invasive or open liver resections of various anatomical extent and technical difficulty levels. METHODS: In this retrospective cohort study, patients that underwent a right hemihepatectomy (RH), technically major resection (anatomically minor resection in segment 1, 4a, 7 or 8; TMR) or left lateral sectionectomy (LLS) between 2000 and 2022 were extracted from a multicenter database comprising the prospectively maintained databases of 31 centers in 13 countries. Minimally invasive procedures performed during the learning curve were omitted. Logistic regression models, performed separately for 9 different groups based on stratification by procedure type and allocated surgical approach, were used to assess the association between the fourth quartile of operative time (25% of patients with the longest operative time) and postoperative complications. RESULTS: Overall, 5424 patients were included: 1351 underwent RH (865 open, 373 laparoscopic and 113 robotic), 2821 TMR (1398 open, 1225 laparoscopic and 198 robotic), and 1252 LLS (241 open, 822 laparoscopic and 189 robotic). After adjusting for potential confounders (age, BMI, gender, ASA grade, previous abdominal surgery, disease type and extent, blood loss, Pringle, intraoperative transfusions and incidents), the fourth quartile of operative time, compared to the first three quartiles, was associated with an increased risk of postoperative complications after open, laparoscopic and robotic TMR (aOR 1.35, p = 0.031; aOR 1.74, p = 0.001 and aOR 3.11, p = 0.014, respectively), laparoscopic and robotic RH (aOR 1.98, p = 0.018 and aOR 3.28, p = 0.055, respectively) and solely laparoscopic LLS (aOR 1.69, p = 0.019). CONCLUSIONS: A prolonged operative time is associated with an increased risk of postoperative complications, although it remains to be defined if this is a causal relationship.

Pan-European survey on current treatment strategies in patients with upfront resectable colorectal liver metastases.

BACKGROUND: There is a lack of consensus on the definition of upfront resectability and use of perioperative systemic therapy for colorectal liver metastases (CRLM). This survey aimed to summarize the current treatment strategies for upfront resectable CRLM throughout Europe. METHODS: A survey was sent to all members of the European-African Hepato-Pancreato-Biliary Association to gain insight into the current views on resectability and the use of systemic therapy for upfront resectable CRLM. RESULTS: The survey was completed by 87 surgeons from 24 countries. The resectability of CRLM is mostly based on the volume of the future liver remnant, while considering tumor biology. Thermal ablation was considered as an acceptable adjunct to resection in parenchymal-sparing CRLM surgery by 77 % of the respondents. A total of 40.2 % of the respondents preferred standard perioperative systemic therapy and 24.1 % preferred standard upfront local treatment. CONCLUSION: Among the participating European hepato-pancreato-biliary surgeons, there is a high degree of consensus on the definition of CRLM resectability. However, there is much variety in the use of adjunctive thermal ablation. Major variations persist in the use of perioperative systemic therapy in cases of upfront resectable CRLM, stressing the need for further evidence and a consensus.

Trends in the characteristics and perioperative outcomes of patients undergoing laparoscopic and open resections for benign liver lesions: An international multicenter retrospective cohort study of 845 patients.

BACKGROUND: Solid benign liver lesions (BLL) are increasingly discovered, but clear indications for surgical treatment are often lacking. Concomitantly, laparoscopic liver surgery is increasingly performed. The aim of this study was to assess if the availability of laparoscopic surgery has had an impact on the characteristics and perioperative outcomes of patients with BLL. METHODS: This is a retrospective international multicenter cohort study, including patients undergoing a laparoscopic or open liver resection for BLL from 19 centers in eight countries. Patients were divided according to the time period in which they underwent surgery (2008-2013, 2014-2016, and 2017-2019). Unadjusted and risk-adjusted (using logistic regression) time-trend analyses were performed. The primary outcome was textbook outcome (TOLS), defined as the absence of intraoperative incidents ≥ grade 2, bile leak ≥ grade B, severe complications, readmission and 90-day or in-hospital mortality, with the absence of a prolonged length of stay added to define TOLS+. RESULTS: In the complete dataset comprised of patients that underwent liver surgery for all indications, the proportion of patients undergoing liver surgery for benign disease remained stable (12.6% in the first time period, 11.9% in the second time period and 12.1% in the last time period, p = 0.454). Overall, 845 patients undergoing a liver resection for BLL in the first (n = 374), second (n = 258) or third time period (n = 213) were included. The rates of ASA-scores≥3 (9.9%-16%,p < 0.001), laparoscopic surgery (57.8%-77%,p < 0.001), and Pringle maneuver use (33.2%-47.2%,p = 0.001) increased, whereas the length of stay decreased (5 to 4 days,p < 0.001). There were no significant changes in the TOLS rate (86.6%-81.3%,p = 0.151), while the TOLS + rate increased from 41.7% to 58.7% (p < 0.001). The latter result was confirmed in the risk-adjusted analyses (aOR 1.849,p = 0.004). CONCLUSION: The surgical treatment of BLL has evolved with an increased implementation of the laparoscopic approach and a decreased length of stay. This evolution was paralleled by stable TOLS rates above 80% and an increase in the TOLS + rate.

An International Expert Delphi Consensus on Defining Textbook Outcome in Liver Surgery (TOLS).

OBJECTIVE: To reach global expert consensus on the definition of TOLS in minimally invasive and open liver resection among renowned international expert liver surgeons using a modified Delphi method. BACKGROUND: Textbook outcome is a novel composite measure combining the most desirable postoperative outcomes into one single measure and representing the ideal postoperative course. Despite a recently developed international definition of Textbook Outcome in Liver Surgery (TOLS), a standardized and expert consensus-based definition is lacking. METHODS: This international, consensus-based, qualitative study used a Delphi process to achieve consensus on the definition of TOLS. The survey comprised 6 surgical domains with a total of 26 questions on individual surgical outcome variables. The process included 4 rounds of online questionnaires. Consensus was achieved when a threshold of at least 80% agreement was reached. The results from the Delphi rounds were used to establish an international definition of TOLS. RESULTS: In total, 44 expert liver surgeons from 22 countries and all 3 major international hepato-pancreato-biliary associations completed round 1. Forty-two (96%), 41 (98%), and 41 (98%) of the experts participated in round 2, 3, and 4, respectively. The TOLS definition derived from the consensus process included the absence of intraoperative grade ≥2 incidents, postoperative bile leakage grade B/C, postoperative liver failure grade B/C, 90-day major postoperative complications, 90-day readmission due to surgery-related major complications, 90-day/in-hospital mortality, and the presence of R0 resection margin. CONCLUSIONS: This is the first study providing an international expert consensus-based definition of TOLS for minimally invasive and open liver resections by the use of a formal Delphi consensus approach. TOLS may be useful in assessing patient-level hospital performance and carrying out international comparisons between centers with different clinical practices to further improve patient outcomes.

High mortality after ALPPS for perihilar cholangiocarcinoma: case-control analysis including the first series from the international ALPPS registry.

INTRODUCTION: Resection of perihilar cholangiocarcinoma (PHC) entails high-risk surgery with postoperative mortality reported up to 18%, even in specialized centers. The aim of this study was to compare outcomes of PHC patients who underwent associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) to patients who underwent resection without ALPPS. METHODS: All patients who underwent ALPPS for PHC were identified from the international ALPPS registry and matched controls were selected from a standard resection cohort from two centers based on future remnant liver size. Outcomes included morbidity, mortality, and overall survival. RESULTS: ALPPS for PHC was associated with 48% (14/29) 90-day mortality. 90-day mortality was 13% in 257 patients who underwent major liver resection for PHC without ALPPS. The 29 ALPPS patients were matched to 29 patients resected without ALPPS, with similar future liver remnant volume (P = 0.480). Mortality in the matched control group was 24% (P = 0.100) and median OS was 27 months, comparted to 6 months after ALPPS (P = 0.064). DISCUSSION: Outcomes of ALPPS for PHC appear inferior compared to standard extended resections in high-risk patients. Therefore, portal vein embolization should remain the preferred method to increase future remnant liver volume in patients with PHC. ALPPS is not recommended for PHC.

Laparoscopic Versus Open Hemihepatectomy: The ORANGE II PLUS Multicenter Randomized Controlled Trial.

PURPOSE: To compare outcomes after laparoscopic versus open major liver resection (hemihepatectomy) mainly for primary or metastatic cancer. The primary outcome measure was time to functional recovery. Secondary outcomes included morbidity, quality of life (QoL), and for those with cancer, resection margin status and time to adjuvant systemic therapy. PATIENTS AND METHODS: This was a multicenter, randomized controlled, patient-blinded, superiority trial on adult patients undergoing hemihepatectomy. Patients were recruited from 16 hospitals in Europe between November 2013 and December 2018. RESULTS: Of the 352 randomly assigned patients, 332 patients (94.3%) underwent surgery (laparoscopic, n = 166 and open, n = 166) and comprised the analysis population. The median time to functional recovery was 4 days (IQR, 3-5; range, 1-30) for laparoscopic hemihepatectomy versus 5 days (IQR, 4-6; range, 1-33) for open hemihepatectomy (difference, -17.5% [96% CI, -25.6 to -8.4]; P < .001). There was no difference in major complications (laparoscopic 24/166 [14.5%] v open 28/166 [16.9%]; odds ratio [OR], 0.84; P = .58). Regarding QoL, both global health status (difference, 3.2 points; P < .001) and body image (difference, 0.9 points; P < .001) scored significantly higher in the laparoscopic group. For the 281 (84.6%) patients with cancer, R0 resection margin status was similar (laparoscopic 106 [77.9%] v open 122 patients [84.1%], OR, 0.60; P = .14) with a shorter time to adjuvant systemic therapy in the laparoscopic group (46.5 days v 62.8 days, hazard ratio, 2.20; P = .009). CONCLUSION: Among patients undergoing hemihepatectomy, the laparoscopic approach resulted in a shorter time to functional recovery compared with open surgery. In addition, it was associated with a better QoL, and in patients with cancer, a shorter time to adjuvant systemic therapy with no adverse impact on cancer outcomes observed.

The differential benefit of laparoscopic over open minor liver resection for lesions situated in the anterolateral or posterosuperior segments.

Background: It is well known that laparoscopic liver surgery can offer advantages over open liver surgery in selected patients. However, what type of procedures can benefit most from a laparoscopic approach has been investigated poorly thus far. The aim of this study is thus to define the extent of advantages of laparoscopic over open liver surgery for lesions in the anterolateral (AL) and posterosuperior (PS) segments. Methods: In this international multicentre retrospective cohort study, laparoscopic and open minor liver resections for lesions in the AL and PS segments were compared after propensity score matching. The differential benefit of laparoscopy over open liver surgery, calculated using bootstrap sampling, was compared between AL and PS resections and expressed as a Delta of the differences. Results: After matching, 3,040 AL and 2,336 PS resections were compared, encompassing open and laparoscopic procedures in a 1:1 ratio. AL and PS laparoscopic liver resections were more advantageous in comparison to open in terms of blood loss, transfusion rate, complications, and length of stay. However, AL resections benefitted more from laparoscopy than PS in terms of overall and severe complications (D-difference were 4.8%, P=0.046 and 3%, P=0.046) and blood loss (D-difference was 195 mL, P<0.001). Similar results were observed in the subset for high-volume centres, while in recent years no significant differences were found in the differential benefit between AL and PS segments. Conclusions: The advantage of laparoscopic over open liver surgery is greater in the AL segments than in the PS segments.

Hilar cholangiocarcinoma: preoperative liver optimization with multidisciplinary approach. Toward a better outcome.

INTRODUCTION: The diagnosis and treatment of hilar tumors requires a multidisciplinary approach based on the synergy of radiologists, surgeons, oncologists, and gastroenterologists. Klatskin tumor is a relatively rare disease with a poor prognosis. Currently, the only possible treatment is represented by the removal of the tumor associated with radical surgery, even though its results are still jeopardized by significant morbidity and mortality. A proper preoperative optimization of the patient, including staging laparoscopy, biliary drainage, and portal vein embolization, may improve short-term outcome. The purpose of this study was to evaluate the short- and long-term impact of preoperative optimization in patients affected by hilar cholangiocarcinoma. METHODS: From January 2004 to May 2012, 94 patients with preoperative diagnosis of Klastkin tumors were candidates for surgery at the Hepatobiliary Surgery Unit of the Hospital San Raffaele in Milan. The data of all patients were prospectively collected and retrospectively reviewed. The outcome was evaluated in terms of perioperative morbidity and mortality and overall and disease-free survival. Short-term outcome of patients undergoing preoperative optimization was compared with outcome of patients who did not undergo it in terms of intraoperative data, morbidity and mortality. RESULTS: Of 94 patients undergoing surgery, 80 underwent hepatic and biliary confluence resection. Fourteen patients were considered unresectable due to the presence of peritoneal carcinomatosis or advanced disease seen during staging laparoscopy or at laparotomy and therefore were excluded from the analysis. Seventy-five (93.7 %) patients underwent major liver resections: in 14 of these, surgery was performed at a distance of 30-40 days from PVE. In 55 patients, biliary drainage was preoperatively placed for palliation of obstructive jaundice. The postoperative morbidity rate was 51.2 % and mortality 6.2 %. The most frequent cause of death was postoperative liver failure. Five-year survival rate was 29 %. Patients undergoing preoperative optimization experienced a significant reduction of postoperative morbidity, especially in terms of infectious related events. CONCLUSIONS: Klatskin tumor remains a disease associated with poor prognosis, but a correct preoperative diagnostic and therapeutic management provides tools to perform this type of surgery with acceptable morbidity and mortality, thus improving long-term results.

Surgical approach to multifocal hepatocellular carcinoma with portal vein thrombosis and arterioportal shunt leading to portal hypertension and bleeding: a case report.

It is reported the case of a 69 years man who presented to the Emergency Room because of pain and abdominal distension from ascites. After admission and paracentesis placement, he developed a digestive hemorrhage due to oesophageal varices from portal ipertension secondary to the formation of a portal shunt concomitant with a multifocal HepatoCellular Carcinoma (HCC) with portal vein thrombosis (PVT). The patient underwent endoscopic varices ligation, twice transarterial embolization (TAE) of arterial branches feeding the shunt and subsequent left hepatectomy. During the postoperative course he developed mild and transient signs of liver failure and was discharged in postoperative day 16. He is alive and disease free 8 months after surgery.

Incidence and Clinical Impact of Bile Leakage after Laparoscopic and Open Liver Resection: An International Multicenter Propensity Score-Matched Study of 13,379 Patients.

BACKGROUND: Despite many developments, postoperative bile leakage (POBL) remains a relatively common postoperative complication after laparoscopic liver resection (LLR) and open liver resection (OLR). This study aimed to assess the incidence and clinical impact of POBL in patients undergoing LLR and OLR in a large international multicenter cohort using a propensity score-matched analysis. STUDY DESIGN: Patients undergoing LLR or OLR for all indications between January 2000 and October 2019 were retrospectively analyzed using a large, international, multicenter liver database including data from 15 tertiary referral centers. Primary outcome was clinically relevant POBL (CR-POBL), defined as Grade B/C POBL. RESULTS: Overall, 13,379 patients met the inclusion criteria and were included in the analysis (6,369 LLR and 7,010 OLR), with 6.0% POBL. After propensity score matching, a total of 3,563 LLR patients were matched to 3,563 OLR patients. In both groups, propensity score matching accounted for similar extent and types of resections. The incidence of CR-POBL was significantly lower in patients after LLR as compared with patients after OLR (2.6% vs 6.0%; p < 0.001). Among the subgroup of patients with CR-POBL, patients after LLR experienced less severe (non-POBL) postoperative complications (10.1% vs 20.9%; p = 0.028), a shorter hospital stay (12.5 vs 17 days; p = 0.001), and a lower 90-day/in-hospital mortality (0% vs 5.4%; p = 0.027) as compared with patients after OLR with CR-POBL. CONCLUSION: Patients after LLR seem to experience a lower rate of CR-POBL as compared with the open approach. Our findings suggest that in patients after LLR, the clinical impact of CR-POBL is less than after OLR.

Indications, trends, and perioperative outcomes of minimally invasive and open liver surgery in non-obese and obese patients: An international multicentre propensity score matched retrospective cohort study of 9963 patients.

BACKGROUND: Despite the worldwide increase of both obesity and the use of minimally invasive liver surgery (MILS), evidence regarding the safety and eventual benefits of MILS in obese patients is scarce. The aim of this study was therefore to compare the outcomes of non-obese and obese patients (BMI 18.5-29.9 and BMI≥30, respectively) undergoing MILS and OLS, and to assess trends in MILS use among obese patients. METHODS: In this retrospective cohort study, patients operated at 20 hospitals in eight countries (2009-2019) were included and the characteristics and outcomes of non-obese and obese patients were compared. Thereafter, the outcomes of MILS and OLS were compared in both groups after propensity-score matching (PSM). Changes in the adoption of MILS during the study period were investigated. RESULTS: Overall, 9963 patients were included (MILS: n = 4687; OLS: n = 5276). Compared to non-obese patients (n = 7986), obese patients(n = 1977) were more often comorbid, less often received preoperative chemotherapy or had a history of previous hepatectomy, had longer operation durations and more intraoperative blood loss (IOBL), paralleling significantly higher rates of wound- and respiratory-related complications. After PSM, MILS, compared to OLS, was associated, among both non-obese and obese patients, with less IOBL (200 ml vs 320 ml, 200 ml vs 400 ml, respectively), lower rates of transfusions (6.6% vs 12.8%, 4.7% vs 14.7%), complications (26.1% vs 35%, 24.9% vs 34%), bile leaks(4% vs 7%, 1.8% vs 4.9%), liver failure (0.7% vs 2.3%, 0.2% vs 2.1%), and a shorter length of stay(5 vs 7 and 4 vs 7 days). A cautious implementation of MILS over time in obese patients (42.1%-53%, p < .001) was paralleled by stable severe morbidity (p = .433) and mortality (p = .423) rates, despite an accompanying gradual increase in surgical complexity. CONCLUSIONS: MILS is increasingly adopted and associated with perioperative benefits in both non-obese and obese patients.

Laparoscopic versus open resections in the posterosuperior liver segments within an enhanced recovery programme (ORANGE Segments): study protocol for a multicentre randomised controlled trial.

BACKGROUND: A shift towards parenchymal-sparing liver resections in open and laparoscopic surgery emerged in the last few years. Laparoscopic liver resection is technically feasible and safe, and consensus guidelines acknowledge the laparoscopic approach in the posterosuperior segments. Lesions situated in these segments are considered the most challenging for the laparoscopic approach. The aim of this trial is to compare the postoperative time to functional recovery, complications, oncological safety, quality of life, survival and costs after laparoscopic versus open parenchymal-sparing liver resections in the posterosuperior liver segments within an enhanced recovery setting. METHODS: The ORANGE Segments trial is an international multicentre randomised controlled superiority trial conducted in centres experienced in laparoscopic liver resection. Eligible patients for minor resections in the posterosuperior segments will be randomised in a 1:1 ratio to undergo laparoscopic or open resections in an enhanced recovery setting. Patients and ward personnel are blinded to the treatment allocation until postoperative day 4 using a large abdominal dressing. The primary endpoint is time to functional recovery. Secondary endpoints include intraoperative outcomes, length of stay, resection margin, postoperative complications, 90-day mortality, time to adjuvant chemotherapy initiation, quality of life and overall survival. Laparoscopic liver surgery of the posterosuperior segments is hypothesised to reduce time to functional recovery by 2 days in comparison with open surgery. With a power of 80% and alpha of 0.04 to adjust for interim analysis halfway the trial, a total of 250 patients are required to be randomised. DISCUSSION: The ORANGE Segments trial is the first multicentre international randomised controlled study to compare short- and long-term surgical and oncological outcomes of laparoscopic and open resections in the posterosuperior segments within an enhanced recovery programme. TRIAL REGISTRATION: ClinicalTrials.gov NCT03270917 . Registered on September 1, 2017. Before start of inclusion. PROTOCOL VERSION: version 12, May 9, 2017.

Assessment of Textbook Outcome in Laparoscopic and Open Liver Surgery.

Importance: Textbook outcome (TO) is a composite measure that captures the most desirable surgical outcomes as a single indicator, yet to date TO has not been defined and assessed in the field of laparoscopic liver resection (LLR) and open liver resection (OLR). Objective: To obtain international agreement on the definition of TO in liver surgery (TOLS) and to assess the incidence of TO in LLR and OLR in a large international multicenter database using a propensity-score matched analysis. Design, Setting, and Participants: Patients undergoing LLR or OLR for all liver diseases between January 2011 and October 2019 were analyzed using a large international multicenter liver surgical database. An international survey was conducted among all members of the European-African Hepato-Pancreato-Biliary Association (E-AHPBA) and International Hepato-Pancreato-Biliary Association (IHPBA) to reach agreement on the definition of TOLS. The rate of TOLS was assessed for LLR and OLR before and after propensity-score matching. Factors associated with achieving TOLS were investigated. Main Outcomes and Measures: Textbook outcome, with TOLS defined as the absence of intraoperative incidents of grade 2 or higher, postoperative bile leak grade B or C, severe postoperative complications, readmission within 30 days after discharge, in-hospital mortality, and the presence of R0 resection margin. Results: A total of 8188 patients (4559 LLR; median age, 65 years [interquartile range, 55-73 years]; 2529 were male [55.8%] and 3629 OLR; median age, 64 years [interquartile range, 56-71 years]; 2204 were male [60.7%]) were included in the analysis of whom 69.1% achieved TOLS; 74.8% for LLR and 61.9% for OLR (P < .001). On multivariable analysis, American Society of Anesthesiologists grade III, previous abdominal surgery, histological diagnosis of colorectal liver metastases (odds ratio [OR], 0.656 [95% CI, 0.457-0.940]; P = .02), cholangiocarcinoma, non-CRLM, a tumor size of 30 mm or more, minor resection of posterior/superior segments (OR, 0.716 [95% CI, 0.577-0.887]; P = .002), anatomically major resection (OR, 0.579 [95% CI, 0.418-0.803]; P = .001), and nonanatomical resection (OR, 0.612 [95% CI, 0.476-0.788]; P < .001) were associated with a worse TOLS rate after LLR. For OLR, only histological diagnosis of cholangiocarcinoma (OR, 0.360 [95% CI, 0.214-0.607]; P < .001) and a tumor size of 30 mm or more (30-50 mm = OR, 0.718 [95% CI, 0.565-0.911]; P = .01; 50.1-100 mm = OR, 0.729 [95% CI, 0.554-0.960]; P = .02; >10 cm = OR, 0.550 [95% CI, 0.366-0.826]; P = .004) were associated with a worse TOLS rate. Conclusions and Relevance: In this multicenter study, TOLS was found to be a useful tool for assessing patient-level hospital performance and may have utility in optimizing patient outcomes after LLR and OLR.