From morbidity reduction to cost-effectiveness: Enhanced recovery after surgery (ERAS) society recommendations in minimal invasive liver surgery

PURPOSE

Minimal-invasive liver surgery (MILS) reduces surgical trauma and is associated with fewer postoperative complications. To amplify these benefits, perioperative multimodal concepts like Enhanced Recovery after Surgery (ERAS), can play a crucial role. We aimed to evaluate the cost-effectiveness for MILS in an ERAS program, considering the necessary additional workforce and associated expenses.

METHODS

A prospective observational study comparing surgical approach in patients within an ERAS program compared to standard care from 2018-2022 at the Charité - Universitätsmedizin Berlin. Cost data were provided by the medical controlling office. ERAS items were applied according to the ERAS society recommendations.

RESULTS

537 patients underwent liver surgery (46% laparoscopic, 26% robotic assisted, 28% open surgery) and 487 were managed by the ERAS protocol. Implementation of ERAS reduced overall postoperative complications in the MILS group (18% vs. 32%, p = 0.048). Complications greater than Clavien-Dindo grade II incurred the highest costs (€ 31,093) compared to minor (€ 17,510) and no complications (€13,893; p < 0.001). In the event of major complications, profit margins were reduced by a median of € 6,640.

CONCLUSIONS

Embracing the ERAS society recommendations in liver surgery leads to a significant reduction of complications. This outcome justifies the higher cost associated with a well-structured ERAS protocol, as it effectively offsets the expenses of complications.

Short-term postoperative outcomes of lymphadenectomy for cholangiocarcinoma, hepatocellular carcinoma and colorectal liver metastases in the modern era of liver surgery: Insights from the StuDoQ|Liver registry

INTRODUCTION

The clinical role of lymphadenectomy (LAD) as part of hepatic resection for malignancies of the liver remains unclear. In this study, we aimed to report on the use cases and postoperative outcomes of liver resection and simultaneous LAD for hepatic malignancies (HM).

MATERIALS AND METHODS

Clinicopathological data from patients who underwent surgery at 13 German centers from 2017 to 2022 (n = 3456) was extracted from the StuDoQ|Liver registry of the German Society of General and Visceral Surgery. Propensity-score matching (PSM) was performed to account for the extent of liver resection and patient demographics.

RESULTS

LAD was performed in 545 (16%) cases. The most common indication for LAD was cholangiocarcinoma (CCA), followed by colorectal liver metastases (CRLM) and hepatocellular carcinoma (HCC). N+ status was found in 7 (8%), 59 (35%), and 56 cases (35%) for HCC, CCA, and CRLM, respectively (p < 0.001). The LAD rate was highest for robotic-assisted resections (28%) followed by open (26%) and laparoscopic resections (13%), whereas the number of resected lymph nodes was equivalent between the techniques (p = 0.303). LAD was associated with an increased risk of liver-specific postoperative complications, especially for patients with HCC.

CONCLUSION

In this multicenter registry study, LAD was found to be associated with an increased risk of liver-specific complications. The highest rate of LAD was observed among robotic liver resections.

Robotic-Assisted Ivor Lewis Esophagectomy Is Safe and Cost Equivalent Compared to Minimally Invasive Esophagectomy in a Tertiary Referral Center

In recent decades, robotic-assisted minimally invasive esophagectomy (RAMIE) has been increasingly adopted for patients with esophageal cancer (EC) or cancer of the gastroesophageal junction (GEJ). However, concerns regarding its costs compared to conventional minimally invasive esophagectomy (MIE) have emerged. This study examined outcomes and costs of RAMIE versus total MIE in 128 patients who underwent Ivor Lewis esophagectomy for EC/GEJ at our department between 2017 and 2021. Surgical costs were higher for RAMIE (EUR 12,370 vs. EUR 10,059, p < 0.001). Yet, median daily (EUR 2023 vs. EUR 1818, p = 0.246) and total costs (EUR 30,510 vs. EUR 29,180, p = 0.460) were comparable. RAMIE showed a lower incidence of postoperative pneumonia (8% vs. 25%, p = 0.029) and a trend towards shorter hospital stays (15 vs. 17 days, p = 0.205), which may have equalized total costs. Factors independently associated with higher costs included readmission to the intensive care unit (hazard ratio [HR] = 7.0), length of stay (HR = 13.5), anastomotic leak (HR = 17.0), and postoperative pneumonia (HR = 5.4). In conclusion, RAMIE does not impose an additional financial burden. This suggests that RAMIE may be considered as a valid alternative approach for esophagectomy. Attention to typical cost factors can enhance postoperative care across surgical methods.

Minimal Invasive Versus Open Surgery for Colorectal Liver Metastases: A Multicenter German StuDoQ|Liver Registry-Based Cohort Analysis in Germany

Objective

To compare the outcome of minimally invasive liver surgery (MILS) to open liver surgery (OLS) for resection of colorectal liver metastases (CRLM) on a nationwide level.

Background

Colorectal cancer is the third most common malignancy worldwide. Up to 50% of all patients with colorectal cancer develop CRLM. MILS represents an attractive alternative to OLS for treatment of CRLM.

Methods

Retrospective cohort study using the prospectively recorded German Quality management registry for liver surgery. Propensity-score matching was performed to account for variance in the extent of resection and patient demographics.

Results

In total, 1037 patients underwent liver resection for CRLM from 2019 to 2021. MILS was performed in 31%. Operative time was significantly longer in MILS (234 vs 222 minutes, P = 0.02) compared with OLS. After MILS, median length of hospital stay (LOS) was significantly shorter (7 vs 10 days; P < 0.001). Despite 76% of major resections being OLS, postoperative complications and 90-day morbidity and mortality did not differ. The Pringle maneuver was more frequently used in MILS (48% vs 40%, P = 0.048). After propensity-score matching for age, body mass index, Eastern Cooperative Oncology Group, and extent of resection, LOS remained shorter in the MILS cohort (6 vs 10 days, P < 0.001) and operative time did not differ significantly (P = 0.2).

Conclusion

MILS is not the standard for resection of CRLM in Germany. Drawbacks, such as a longer operative time remain. However, if technically possible, MILS is a reasonable alternative to OLS for resection of CRLM, with comparable postoperative complications, reduced LOS, and equal oncological radicality.

Postoperative infectious complications are associated with diminished overall survival of patients undergoing resection for colorectal liver metastases

INTRODUCTION

Postoperative infectious complications (PIC) remain one of the most common complications after surgery. The influence of PIC on long-term survival for patients after liver surgery for colorectal liver metastases (CRLM) needs further investigation.

METHODS

Data of patients who underwent liver resection for CRLM between 2012 and 2017 at the Department of Surgery, Campus Charité Mitte and Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin were evaluated. Overall survival (OS) was stratified according to the development of PIC. Independent predictors of PIC and diminished survival were identified using regression models.

RESULTS

Of 270 patients, eighty-four (31%) patients developed PIC including intraabdominal infections (n = 51, 61%), cholangitis (n = 5, 6%), pneumonia (n = 12, 14%), wound infections (n = 28, 33%), urinary tract infections (n = 5, 6%), or central line-associated bloodstream infections (n = 4, 5%). PIC were associated with a significantly diminished five-year OS (30% vs. 43%, p = 0.008). Age >65 years (p = 0.016, hazard ratio [HR] = 2.2, 95% confidence interval [CI] = 1.2-4.0), comorbidity (p = 0.019, HR [95% CI] = 2.4 [1.2-4.9]), simultaneous resection of primary tumor (p = 0.005, HR [95% CI] = 4.3 [1.6-11.9]), biliary drainage (p < 0.001, HR [95% CI] = 4.1 [2.0-8.5]), and length of procedure ≥272 min (p = 0.012, HR [95% CI] = 2.2 [1.2-4.1]) were independent predictors for the development of PIC. Body-mass index (BMI) > 30 kg/m2 (p = 0.002, HR [95% CI] = 2.4 [1.4-4.0]), postoperative major complications (p = 0.003, HR [95% CI] = 2.2 [1.3-3.8]), and 3- or 4-MRGN bacteria (p = 0.001, HR [95% CI] = 7.7 [2.2-27.3]) were independently associated with diminished OS.

CONCLUSIONS

PIC are associated with diminished OS after resection for CRLM. Age >65 years, comorbidities, simultaneous resection of the primary tumor, and biliary drainages were identified as independent risk factors for the development of PIC. High BMI, postoperative major morbidity and 3-/4-MRGN bacteria were independently predictive of worse OS. These factors need to be considered in perioperative management for patients with CRLM.

A surgical strategy for intrahepatic cholangiocarcinoma - the hilar first concept

PURPOSE

The present study assesses long-term overall survival (OS) and disease-free survival (DFS) after curative resection for intrahepatic cholangiocarcinoma (ICCA) depending on resection margin (RM) status and lymph node (LN) status.

METHODS

Clinical data of all consecutively resected patients with ICCA at a single high-volume center between 2005 and 2018 were collected. Minimum follow-up was 36 months. Perioperative and long-term oncological outcome was assessed.

RESULTS

One hundred ninety-two cases were included in the analysis. Thirty- and 90-day-mortality was 5.2% (n = 10) and 10.9% (n = 21). OS was 26 months with 1-, 2-, and 5-year-OS rates of 72%, 53%, and 26%. One-, 2-, and 5-year-DFS rates were 54%, 42%, and 35% (N0 vs. N1: 29 vs. 9 months, p = 0.116). R1 was not found to be an independent risk factor for reduced survival in the overall cohort (p = 0.098). When differentiating according to the LN status, clear resection margins were significantly associated with increased DFS for N0 cases (50 months vs. 9 months, p = 0.004). For N1 cases, no significant difference in DFS was calculated for R0 compared to R1 cases (9 months vs. 9 months, p = 0.88). For N0 cases, clear resection margins > 10 mm were associated with prolonged OS (p = 0.048).

CONCLUSION

For N1 cases, there was no significant survival benefit when comparing R0 versus R1, while the complication rate remained high for the extended resection types. In view of merging multimodal treatment, the hilar first concept assesses locoregional LN status for optimal surgical therapy.

Robotic versus laparoscopic versus open major hepatectomy - an analysis of costs and postoperative outcomes in a single-center setting

PURPOSE

In the era of minimal-invasive surgery, the introduction of robotic liver surgery (RS) was accompanied by concerns about the increased financial expenses of the robotic technique in comparison to the established laparoscopic (LS) and conventional open surgery (OS). Therefore, we aimed to evaluate the cost-effectiveness of RS, LS and OS for major hepatectomies in this study.

METHODS

We analyzed financial and clinical data on patients who underwent major liver resection for benign and malign lesions from 2017 to 2019 at our department. Patients were grouped according to the technical approach in RS, LS, and OS. For better comparability, only cases stratified to the Diagnosis Related Groups (DRG) H01A and H01B were included in this study. Financial expenses were compared between RS, LS, and OS. A binary logistic regression model was used to identify parameters associated with increased costs.

RESULTS

RS, LS and OS accounted for median daily costs of 1,725 €, 1,633 € and 1,205 €, respectively (p < 0.0001). Median daily (p = 0.420) and total costs (16,648 € vs. 14,578 €, p = 0.076) were comparable between RS and LS. Increased financial expenses for RS were mainly caused by intraoperative costs (7,592 €, p < 0.0001). Length of procedure (hazard ratio [HR] = 5.4, 95% confidence interval [CI] = 1.7-16.9, p = 0.004), length of stay (HR [95% CI] = 8.8 [1.9-41.6], p = 0.006) and development of major complications (HR [95% CI] = 2.9 [1.7-5.1], p < 0.0001) were independently associated with higher costs.

CONCLUSIONS

From an economic perspective, RS may be considered a valid alternative to LS for major liver resections.

Simplifying minimally invasive right hepatectomy

BACKGROUND

Extrahepatic transection of the right hepatic artery and right portal vein before parenchymal dissection is a widely used standard for minimal invasive right hepatectomy. Hereby, hilar dissection represents a technical difficulty. We report our results of a simplified approach in which the hilar dissection is omitted and the line of dissection is defined with ultrasound.

METHODS

Patients undergoing minimally invasive right hepatectomy were included. Ultrasound-guided hepatectomy (UGH) was defined by the following main steps: (1) ultrasound-guided definition of the transection line, (2) dissection of the liver parenchyma according to the caudal approach, (3) intraparenchymal transection of the right pedicle and (4) of the right liver vein, respectively. Intra- and postoperative outcomes of UGH were compared to the standard technique. Propensity score matching was performed to adjust for parameters of perioperative risk.

RESULTS

Median operative time was 310 min in the UGH group compared to 338 min in the control group (p = 0.013). No differences were observed for Pringle maneuver duration (35 min vs. 25 min; p = ns) nor postoperative transaminases levels (p = ns). There was a trend toward a lower major complication rate in the UGH group (13 vs. 25%) and a shorter median hospital stay (8 days vs. 10 days); however, both being short of statistical significance (p = ns). Bile leak was observed in zero cases of UGH compared to 9 out of 32 cases (28%) for the control group (p = 0.020).

CONCLUSIONS

UGH appears to be at least comparable to the standard technique in terms of intraoperative and postoperative outcomes. Accordingly, transection of the right hepatic artery and right portal vein prior to the transection phase can be omitted, at least in selected cases. These results need to be confirmed in a prospective and randomized trial.

Robotic Liver Surgery: Technical Advantages Over Laparoscopic Technique Based on Parameters of Surgical Complexity and Perioperative Outcomes

Introduction: In view of the limited availability, our study addresses the issue of optimal case selection for robotic liver surgery over standard laparoscopy offering an in-detail analysis of intra- and postoperative outcomes. Materials and Methods: Clinical and technical data of all consecutive cases of robotic liver surgery of a single high-volume center from 2018 to 2020 were collected prospectively. Second, we performed a retrospective analysis of all laparoscopic liver resections from 2015 to 2020. Parameters of surgical complexity were extracted and descriptive analysis and statistical hypothesis testing were performed to assess parameters of intraoperative and postoperative outcomes. Results: A total of 121 robotic resections were compared with 435 laparoscopic resections. Shorter robotic operating times were shown for segmentectomies of the right liver lobe compared with laparoscopic procedures (P = .003) with an according trend for extended resections. A shorter duration of applied Pringle's maneuver was observed for robotic procedures. This advantage was further enhanced in cases with close proximity of the tumor to major vessels. There were no significant differences in postoperative morbidity and mortality between both groups. Conclusion: Our study offers the first in-detail analysis of intraoperative and postoperative outcomes of robotic liver surgery depending on established parameters of surgical complexity. The results indicate potential technical advantages of robotic technology in liver surgery based on parameters that can be studied before the operation. When evaluating robotic technology, future studies should focus not only at overall postoperative outcomes, but rather at potential technical intraoperative advantages to allow optimal case selection for robotic liver surgery. Clinical Trial Registration Number: DRKS00017229.

A 25 mm Circular Stapler Anastomosis Is Associated with Higher Anastomotic Leakage Rates Following Minimally Invasive Ivor Lewis Operation

(1) Background: Minimally invasive oesophagectomy (MIE) with intrathoracic anastomosis is increasingly used in treating patients with oesophageal cancer. Anastomotic leakage (AL) remains a critical perioperative complication, despite recent advances in surgical techniques. It remains unclear to what extent the size of the circular stapler (CS), a 25 mm CS or a bigger CS, may affect the incidence of AL. This study aimed to evaluate whether the CS size in oesophagogastrostomy affects the postoperative AL rates and related morbidity in MIE. (2) Methods: We conducted a retrospective review of consecutive patients who had undergone thoracic MIE between August 2014 and July 2019 using a CS oesophagogastric anastomosis at the level of the Vena azygos. The patients were grouped according to CS size (mm): small-sized (SS25) and large-sized (LS29). The patient demographics, data regarding morbidity, and clinical outcomes were compared. The primary outcome measure was the AL rate related to the stapler size. (3) Results: A total of 119 patients were included (SS25: n = 65; LS29: n = 54). Except for the distribution of squamous cell carcinoma, the demographics were similar in each group. The AL rate was 3.7% in the LS29 group and 18.5% in the SS25 group (p = 0.01). The major morbidity (CD ≥ 3a) was significantly more frequent in the SS25 group compared with the LS29 group (p = 0.02). CS size, pulmonary complications, and cardiovascular disease were independent risk factors for AL in the multivariate analysis. (4) Conclusions: A 29 mm CS is associated with significantly improved surgical outcomes following standard MIE at the level of the azygos vein and should be conducted whenever technically feasible.

The effect of age on short-term and mid-term outcomes after thoracoscopic Ivor Lewis esophagectomy: a propensity score-matched analysis

Background

The number of elderly patients diagnosed with esophageal cancer rises. Current information about outcomes in elderly patients undergoing thoracoscopic Ivor Lewis esophagectomy is limited. The objective of this study was to evaluate the influence of age on short-and mid-term outcomes after thoracoscopic Ivor Lewis esophagectomy.

Methods

A retrospective review of 188 patients with esophageal cancer undergoing thoracoscopic Ivor Lewis esophagectomy between August 2014 and July 2019 was performed. Patients were divided into patients aged > 75 years (elderly group (EG), n = 37) and patients ≤ 75 years (younger group (YG), n = 151) and matched using propensity-score matching. Baseline characteristics, length of hospital stay, mortality and major postoperative complications (Clavien-Dindo ≥ grade III) were compared.

Results

After matching 74 patients remained (n = 37 in each group). Postoperatively, no significant differences in major and overall complications, intra-hospital and 30-day mortality, disease-free or overall survival up to 3 years after surgery were noted. The incidence of pulmonary complications (65% vs. 38%) and pneumonia (54% vs. 30%) was significantly higher and the median hospital length of stay (12 vs. 14 days) significantly longer in the EG versus YG.

Conclusion

Thoracoscopic Ivor Lewis esophagectomies resulted in acceptable postoperative major morbidity and mortality without compromising 3-years overall and disease-free survival in elderly compared to younger patients with esophageal cancer. However, the incidence of postoperative pulmonary complications was higher in patients aged over 75 years.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01435-5.

[Laparoscopic Posterolateral Sectionectomy in Hepatocellular Cacinoma - Increasing Oncological Precision by Combining the Glissonean Pedicle Approach and Fluorescence Guidance]

AIM

Minimally invasive procedures have been increasingly performed in liver surgery. Benefits include lower intraoperative blood loss, reduced postoperative morbidity and shorter lengths of hospital stay in comparison to open liver surgery. Exact resection margins seem advantageous in primary liver cancer but challenging to implement with minimally invasive techniques. In this case report, we aimed to increase surgical precision by combining the Glissonean pedicle approach and intraoperative fluorescence guidance.

INDICATION

A 73-year-old female patient with CHILD A liver cirrhosis with chronic hepatitis C virus infection was transferred to our hospital with high levels of alpha-fetoprotein (792 ng/ml). Sectional imaging confirmed the suspected diagnosis of a single hepatocellular carcinoma (HCC) with a size of 2.2 cm in segments VI/VII. In line with the local tumour board recommendation, an anatomical posterolateral sectionectomy using the Glissonean pedicle approach was planned.

METHODS

The patient was placed in the French position. After mobilisation of the right liver, the posterolateral pedicle was encircled and transected. 0.2 mg/kg of body mass indocyanine green (ICG) was then injected intravenously. The perfused parenchyma of segments I-V and VIII turned green, but the unperfused posterolateral segment VI and VII remained native. The transection line was marked under ICG-imaging to indicate the transition of the posterolateral to the anteromedial sector. Parenchymal transection was performed under intermittent ICG-guided imaging. Pathological workup confirmed R0 resection of a well differentiated HCC in a cirrhotic liver (grade 4). The patient was discharged from the hospital on the 6th postoperative day after an uncomplicated course and was confirmed to be tumour-free six months after surgery.

CONCLUSION

As an additional intraoperative tool, ICG-imaging may provide visualisation of segment and sector boundaries and thus may enable precise anatomical resection. Prospective studies are needed to evaluate the added value of this technique, especially with regard to the rate of R0 resections.

Minimally Invasive Versus Open Ivor-Lewis Esophagectomy for Esophageal Cancer or Cancer of the Gastroesophageal Junction: Comparison of Postoperative Outcomes and Long-term Survival Using Propensity Score Matching Analysis

BACKGROUND/AIM

Esophagectomy is crucial for achieving long-term survival in patients with esophageal cancer, while being associated with a significant risk of complications. Aiming to reduce invasiveness and morbidity, total minimal-invasive esophagectomy (MIE) has been gradually implemented worldwide. The aim of the study was to compare MIE to open Ivor-Lewis esophagectomy (OE) for esophageal cancer or cancer of the gastroesophageal junction (GEJ), in terms of postoperative and oncological outcomes.

PATIENTS AND METHODS

Clinicopathological data of patients undergoing oncologic transthoracic esophagectomy (Ivor Lewis procedure) between 2010 and 2019 were assessed. Postoperative outcomes and long-term survival of patients undergoing OE were compared to those after MIE using 1:1 propensity score matching.

RESULTS

After excluding hybrid and robotic procedures, 90 patients who underwent MIE were compared with a matched cohort of 90 patients who underwent OE. MIE was associated with lower major postoperative morbidity (31% vs. 46%, p=0.046) and lower 90-day mortality (2% vs. 12%, p=0.010) compared to OE. MIE showed non-inferior 3-year overall (65% vs. 52%, p=0.019) and comparable disease-free survival rates (49% vs. 51%, p=0.851) in comparison to OE.

CONCLUSION

Our data suggest that MIE should be preferably performed in patients with esophageal cancer or cancer of the GEJ.

CT Body Composition of Sarcopenia and Sarcopenic Obesity: Predictors of Postoperative Complications and Survival in Patients with Locally Advanced Esophageal Adenocarcinoma

BACKGROUND

To assess the impact of body composition imaging biomarkers in computed tomography (CT) on the perioperative morbidity and survival after surgery of patients with esophageal cancer (EC).

METHODS

Eighty-five patients who underwent esophagectomy for locally advanced EC after neoadjuvant therapy between 2014 and 2019 were retrospectively enrolled. Pre- and postoperative CT scans were used to assess the body composition imaging biomarkers (visceral (VAT) and subcutaneous adipose tissue (SAT) areas, psoas muscle area (PMA) and volume (PMV), total abdominal muscle area (TAMA)). Sarcopenia was defined as lumbar skeletal muscle index (LSMI) ≤38.5 cm²/m² in women and ≤52.4 cm²/m² in men. Patients with a body mass index (BMI) of ≥30 were considered obese. These imaging biomarkers were correlated with major complications, anastomotic leakage, postoperative pneumonia, duration of postoperative hospitalization, disease-free survival (DFS), and overall survival (OS).

RESULTS

Preoperatively, sarcopenia was identified in 58 patients (68.2%), and sarcopenic obesity was present in 7 patients (8.2%). Sarcopenic patients were found to have an elevated risk for the occurrence of major complications (OR: 2.587, p = 0.048) and prolonged hospitalization (32 d vs. 19 d, p = 0.040). Patients with sarcopenic obesity had a significantly higher risk for postoperative pneumonia (OR: 6.364 p = 0.018) and a longer postoperative hospital stay (71 d vs. 24 d, p = 0.021). Neither sarcopenia nor sarcopenic obesity was an independent risk factor for the occurrence of anastomotic leakage (p > 0.05). Low preoperative muscle biomarkers (PMA and PMV) and their decrease (ΔPMV and ΔTAMA) during the follow-up period significantly correlated with shorter DFS and OS (p = 0.005 to 0.048).

CONCLUSION

CT body composition imaging biomarkers can identify high-risk patients with locally advanced esophageal cancer undergoing surgery. Sarcopenic patients have a higher risk of major complications, and patients with sarcopenic obesity are more prone to postoperative pneumonia. Sarcopenia and sarcopenic obesity are both subsequently associated with a prolonged hospitalization. Low preoperative muscle mass and its decrease during the postoperative follow-up are associated with lower DFS and OS.

[COVID-19 Pandemic in Germany: The Current Situation in Thoracic Surgery]

BACKGROUND

The new COVID-19 pandemic has an impact on routine thoracic surgery. Various concepts and recommendations are being pursued to protect patients and hospital staff. However, the implementation of these recommendations may depend on the existing infrastructure, local conditions and in-house procedural instructions.

MATERIAL AND METHOD

Between 11th May and 26th May 2020, an anonymous online survey on the topic of COVID-19 was conducted among thoracic surgeons in Germany. The survey consisted of 16 questions on the local COVID-19 case numbers, protective measures, procedural instructions and treatment concepts. The results were summarised, descriptively analysed and discussed.

RESULTS

The response rate of 42.6% (n = 66), included replies from 23 (34.8%) specialised hospitals, 18 (27.3%) maximum care hospitals and 14 (21.2%) university clinics. COVID-19-positive patients were treated in 65 (99%) clinics and 37.9% of the clinics also performed surgery on COVID-19-positive patients. Nasopharyngeal swabs were the main instrument for COVID-19 patient testing (in 95.4% of the clinics). Test results influenced decisions on treatment in 71.2% of the clinics. In 59.1% of clinics, safety equipment was supplemented with FFP2 masks and eye protection during thoracic surgeries due to the COVID-19 pandemic.

DISCUSSION

Almost all thoracic surgeons reported that they had treated patients with COVID-19 and half of them also had performed surgery on COVID-19-positive patients. The applied procedural instructions as well as the effects of COVID-19 on treatment decisions and patient-doctor contact differed between the reporting clinics.

Recurrence at surgical margin following hepatectomy for colorectal liver metastases is not associated with R1 resection and does not impact survival

BACKGROUND

Resection margin status has traditionally been associated with tumor recurrence and oncological outcome following liver resection for colorectal liver metastases. Previous studies, however, did not address the impact of resection margin on the site of tumor recurrence and did not differentiate between true local recurrence at the resection margin and recurrence elsewhere in the liver. This study aimed to determine whether positive resection margins determine local recurrence and whether recurrence at the surgical margin influences long-term survival.

METHODS

Clinicopathological data and oncological outcomes of patients who underwent curative resection for colorectal liver metastases between 2012 and 2017 at 2 major hepatobiliary centers (Bern, Switzerland, and Berlin, Germany) were assessed. Cross-sectional imaging following hepatectomy was reviewed by radiologists in both centers to distinguish between recurrence at the resection margin, defined as hepatic local recurrence, and intrahepatic recurrence elsewhere. The association between surgical margin status and location of tumor recurrence was evaluated, and the impact on overall survival was determined.

RESULTS

During the study period, 345 consecutive patients underwent hepatectomy for colorectal liver metastases. Histologic surgical margins were positive for tumor cells (R1) in 63 patients (18%). After a median follow-up time of 34 months, tumor recurrence was identified in 154 patients (45%). Hepatic local recurrence was not detected more frequently after R1 than after R0 resection (P = .555). Hepatic local recurrence was not associated with worse overall survival (P = .436), while R1 status significantly impaired overall survival (P = .025). Additionally, overall survival was equivalent between patients with hepatic local recurrence and patients with any intrahepatic and/or extrahepatic recurrence. In patients with intrahepatic recurrence only, oncological outcomes improved if local hepatic therapy was possible (resection or ablation) in comparison to patients treated only with chemotherapy or best supportive care (3-year overall survival: 85% vs 39%; P < .0001).

CONCLUSION

The incidence of hepatic local recurrence after hepatectomy for colorectal liver metastases is independent of R1 resection margin status. Additionally, hepatic local recurrence at the resection margin is not associated with worse overall survival compared with any other intra- or extrahepatic recurrence. Therefore, R1 status at hepatectomy seems to be a surrogate factor for advanced disease without influencing location of recurrence and thereby oncological outcome. This finding may support decision-making when extending the indication for surgery in borderline resectable colorectal liver metastases.

The role of hepatectomy for synchronous liver metastases from pancreatic adenocarcinoma

BACKGROUND

The role of hepatectomy for patients with liver metastases from ductal adenocarcinoma of the pancreas (PLM) remains controversial. Therefore, the aim of our study was to examine the postoperative morbidity, mortality, and long-term survivals after liver resection for synchronous PLM.

METHODS

Clinicopathological data of patients who underwent hepatectomy for PLM between 1993 and 2015 were assessed. Major endpoint of this study was to identify predictors of overall survival (OS).

RESULTS

During the study period, 76 patients underwent resection for pancreatic cancer and concomitant hepatectomy for synchronous PLM. Pancreatoduodenectomy, distal pancreatectomy, and total pancreatectomy were performed in 67%, 25%, and 8% of the patients, respectively. The median PLM size was 1 (1-13) cm and 36% of patients had multiple PLM. The majority of patients (96%) underwent a minor liver resection. After a median follow-up time of 130 months, 1-, 3-, and 5-year OS rates were 41%, 13%, and 7%, respectively. Postoperative morbidity and mortality rates were 50% and 5%, respectively. Preoperative and postoperative chemotherapy was administered to 5% and 72% of patients, respectively. In univariate analysis, type of pancreatic procedure (P = .020), resection and reconstruction of the superior mesenteric artery (P = .016), T4 stage (P = .086), R1 margin status at liver resection (P = .001), lymph node metastases (P = .016), poorly differentiated cancer (G3) (P = .037), no preoperative chemotherapy (P = .013), and no postoperative chemotherapy (P = .005) were significantly associated with worse OS. In the multivariate analysis, poorly differentiated cancer (G3) (hazard ratio [HR] = 1.87; 95% confidence interval [CI] = 1.08-3.24; P = .026), R1 margin status at liver resection (HR = 4.97; 95% CI = 1.46-16.86; P = .010), no preoperative chemotherapy (HR = 4.07; 95% CI = 1.40-11.83; P = .010), and no postoperative chemotherapy (HR = 1.88; 95% CI = 1.06-3.29; P = .030) independently predicted worse OS.

CONCLUSIONS

Liver resection for PLM is feasible and safe and may be recommended within the framework of an individualized cancer therapy. Multimodal treatment strategy including perioperative chemotherapy and hepatectomy may provide prolonged survival in selected patients with metastatic pancreatic cancer.

Incidence and Risk Factors of Symptomatic Hiatal Hernia Following Resection for Gastric and Esophageal Cancer

BACKGROUND/AIM

Symptomatic hiatal hernia (HH) following resection for gastric or esophageal cancer is a potentially life-threatening event that may lead to emergent surgery. However, the incidence and risk factors of this complication remain unclear.

PATIENTS AND METHODS

Data of patients who underwent resection for gastric or esophageal cancer between 2005 and 2012 were assessed and the incidence of symptomatic HH was evaluated. Factors associated with an increased risk for HH were investigated.

RESULTS

Resection of gastric or esophageal cancer was performed in 471 patients. The primary tumor was located in the stomach, cardia and esophagus in 36%, 24%, and 40% of patients, respectively. The incidence of symptomatic HH was 2.8% (n=13). All patients underwent surgical hernia repair, 8 patients (61.5%) required emergent procedure, and 3 patients (23%) underwent bowel resection. Morbidity and mortality after HH repair was 38% and 8%, respectively. Factors associated with increased risk for symptomatic HH included Body-Mass-Index (median BMI with HH 27 (23-35) vs. BMI without HH 25 (15-51), p=0.043), diabetes (HH rate: with diabetes, 6.3% vs. without diabetes, 2%, p=0.034), tumor location (HH rate: stomach, 1.2% vs. esophagus, 1.1% vs. cardia, 7.9%, p=0.001), and resection type (HH rate: total/subtotal gastrectomy, 0.7% vs. transthoracic esophagectomy, 2.7% vs. extended gastrectomy, 6.1%, p=0.038).

CONCLUSION

HH is a major adverse event after resection for gastric or esophageal cancer especially among patients undergoing extended gastrectomy for cardia cancer requiring a high rate of repeat surgery. Therefore, intensive follow-up examinations for high-risk patients and early diagnosis of asymptomatic patients are essential for selecting patients for elective surgery to avoid unpredictable emergent events with high morbidity and mortality.

Hepatotoxicity following systemic therapy for colorectal liver metastases and the impact of chemotherapy-associated liver injury on outcomes after curative liver resection

Patients with colorectal liver metastases (CLM) have remarkably benefited from the advances in medical multimodal treatment and surgical techniques over the last two decades leading to significant improvements in long-term survival. More patients are currently undergoing liver resection following neoadjuvant chemotherapy, which has been increasingly established within the framework of curative-indented treatment strategies. However, the use of several cytotoxic agents has been linked to specific liver injuries that not only impair the ability of liver tissue to regenerate but also decrease long-term survival. One of the most common agents included in modern chemotherapy regimens is oxaliplatin, which is considered to induce a parenchymal damage of the liver primarily involving the sinusoids defined as sinusoidal obstruction syndrome (SOS). Administration of bevacizumab, an inhibitor of vascular endothelial growth factor (VEGF), has been reported to improve response of CLM to chemotherapy in clinical studies, concomitantly protecting the liver from the development of SOS. In this review, we aim to summarize current data on multimodal treatment concepts for CLM, give an in-depth overview of liver damage caused by cytostatic agents focusing on oxaliplatin-induced SOS, and evaluate the role of bevacizumab to improve clinical outcomes of patients with CLM and to protect the liver from the development of SOS.

Intracavity frequency-doubled degenerate laser

We develop a green light source with low spatial coherence via intracavity frequency doubling of a solid-state degenerate laser. The second-harmonic emission supports many more transverse modes than the fundamental emission, and exhibits lower spatial coherence. A strong suppression of speckle formation is demonstrated for both fundamental and second-harmonic beams. Using the green emission for fluorescence excitation, we show the coherent artifacts are removed from the full-field fluorescence images. The high power, low spatial coherence, and good directionality make the green degenerate laser an attractive illumination source for parallel imaging and projection display.

High-speed line-field confocal holographic microscope for quantitative phase imaging

We present a high-speed and phase-sensitive reflectance line-scanning confocal holographic microscope (LCHM). We achieved rapid confocal imaging using a fast line-scan CCD camera and quantitative phase imaging using off-axis digital holography (DH) on a 1D, line-by-line basis in our prototype experiment. Using a 20 kHz line scan rate, we achieved a frame rate of 20 Hz for 512x512 pixels en-face confocal images. We realized coherent holographic detection two different ways. We first present a LCHM using off-axis configuration. By using a microscope objective of a NA 0.65, we achieved axial and lateral resolution of ~3.5 micrometers and ~0.8 micrometers, respectively. We demonstrated surface profile measurement of a phase target at nanometer precision and the digital refocusing of a defocused confocal en-face image. Ultrahigh temporal resolution M mode is demonstrated by measuring the vibration of a PZT-actuated mirror driven by a sine wave at 1 kHz. We then report our experimental work on a LCHM using an in-line configuration. In this in-line LCHM, the coherent detection is enabled by moving the reference arm at a constant speed, thereby introducing a Doppler frequency shift that leads to spatial interference fringes along the scanning direction. Lastly, we present a unified formulation that treats off-axis and in-line LCHM in a unified joint spatiotemporal modulation framework and provide a connection between LCHM and the traditional off-axis DH. The presented high-speed LCHM may find applications in optical metrology and biomedical imaging.

Controlling Random Lasing with Three-Dimensional Plasmonic Nanorod Metamaterials

Plasmonics has brought revolutionary advances to laser science by enabling deeply subwavelength nanolasers through surface plasmon amplification. However, the impact of plasmonics on other promising laser systems has so far remained elusive. Here, we present a class of random lasers enabled by three-dimensional plasmonic nanorod metamaterials. While dense metallic nanostructures are usually detrimental to laser performance due to absorption losses, here the lasing threshold keeps decreasing as the volume fraction of metal is increased up to ∼0.07. This is ∼460 times higher than the optimal volume fraction reported thus far. The laser supports spatially confined lasing modes and allows for efficient modulation of spectral profiles by simply tuning the polarization of the pump light. Full-field speckle-free imaging at micron-scales has been achieved by using plasmonic random lasers as the illumination sources. Our findings show that plasmonic metamaterials hold potential to enable intriguing coherent optical sources.

Linearly polarized emission from random lasers with anisotropically amplifying media

Simulations on three-dimensional random lasers were performed by finite-difference time-domain integration of Maxwell's equations combined with rate-equations providing gain. We investigated the frequency-dependent emission polarization of random lasers in the far-field of the sample and characterized the influence of anisotropic pumping in orthogonal polarizations. Under weak scattering, the polarization states of random lasing modes were random for isotropic pumping and linear under anisotropic pumping. These findings are in accordance with recent experimental observations. A crossover was observed towards very strong scattering, in which the scattering destroys the pump-induced polarization-anisotropy of the random lasing modes and randomizes (scrambles) the mode-polarization.

Emission polarization of random lasers in organic dye solutions

This Letter presents a polarimetric study of the emission of random lasers from organic dyes. Coherent lasing modes from samples with ethanol solvent showed a high degree of polarization and did not influence each other in polarization. The proper choice of a laser dye with asymmetric absorption momenta, a highly viscous solvent, and a linear pump polarization can cause the random lasing emission to be completely linearly polarized for all wavelengths within the amplification range.

Spectrally resolving single-shot polarimeter

We demonstrate a spectrally resolving single-shot polarimeter. The system consists of a commercial imaging spectrograph, modified by a birefringent wedge and a segmented polarizer. The physical operating principle and limitations of the apparatus as well as preliminary polarimetric measurements on the emission of random lasers are reported.