Is Precision Surgery Applicable to Colorectal Liver Metastases? A Systematic Review and Meta-analysis of Studies that Investigate the Association of Surgical Technique with Outcomes in the Context of Distinct Tumor Biology.

BACKGROUND: Although some data suggest that patients with mutRAS colorectal liver metastases (CRLM) may benefit from anatomic hepatectomy, this topic remains controversial. We performed a systematic review and meta-analysis to determine whether RAS mutation status was associated with prognosis relative to surgical technique [anatomic resection (AR) vs. nonanatomic resection (NAR)] among patients with CRLM. PATIENTS AND METHODS: A systematic review and meta-analysis of studies were performed to investigate the association of AR versus NAR with overall and liver-specific disease-free survival (DFS and liver-specific DFS, respectively) in the context of RAS mutation status. RESULTS: Overall, 2018 patients (831 mutRAS vs. 1187 wtRAS) were included from five eligible studies. AR was associated with a 40% improvement in liver-specific DFS [hazard ratio (HR) = 0.6, 95% confidence interval (CI) 0.44-0.81, p = 0.01] and a 28% improvement in overall DFS (HR = 0.72, 95% CI 0.54-0.95, p = 0.02) among patients with mutRAS tumors; in contrast, AR was not associated with any improvement in liver-specific DFS or overall DFS among wtRAS patients. These differences may have been mediated by the 40% decreased incidence in R1 resection among patients with mutRAS tumors who underwent AR versus NAR [relative risk (RR): 0.6, 95% CI 0.40-0.91, p = 0.02]. In contrast, the probability of an R1 resection was not decreased among wtRAS patients who underwent AR versus NAR (RR: 0.93, 95% CI 0.69-1.25, p = 0.62). CONCLUSIONS: The data suggest that precision surgery may be relevant to CRLM. Specifically, rather than a parenchymal sparing dogma for all patients, AR may have a role in individuals with mutRAS tumors.

Evaluating Combinations of Biological and Clinicopathologic Factors Linked to Poor Outcomes in Resected Colorectal Liver Metastasis: An External Validation Study.

BACKGROUND: Recent studies have suggested that certain combinations of KRAS or BRAF biomarkers with clinical factors are associated with poor outcomes and may indicate that surgery could be "biologically" futile in otherwise technically resectable colorectal liver metastasis (CRLM). However, these combinations have yet to be validated through external studies. PATIENTS AND METHODS: We conducted a systematic search to identify these studies. The overall survival (OS) of patients with these combinations was evaluated in a cohort of patients treated at 11 tertiary centers. Additionally, the study investigated whether using high-risk KRAS point mutations in these combinations could be associated with particularly poor outcomes. RESULTS: The recommendations of four studies were validated in 1661 patients. The first three studies utilized KRAS, and their validation showed the following median and 5-year OS: (1) 30 months and 16.9%, (2) 24.3 months and 21.6%, and (3) 46.8 months and 44.4%, respectively. When analyzing only patients with high-risk KRAS mutations, median and 5-year OS decreased to: (1) 26.2 months and 0%, (2) 22.3 months and 15.1%, and (3) not reached and 44.9%, respectively. The fourth study utilized BRAF, and its validation showed a median OS of 10.4 months, with no survivors beyond 21 months. CONCLUSION: The combinations of biomarkers and clinical factors proposed to render surgery for CRLM futile, as presented in studies 1 (KRAS high-risk mutations) and 4, appear justified. In these studies, there were no long-term survivors, and survival was similar to that of historic cohorts with similar mutational profiles that received systemic therapies alone for unresectable disease.

Hepatectomy versus systemic therapy for liver-limited BRAF V600E-mutated colorectal liver metastases: multicentre retrospective study.

BACKGROUND: To date, only two studies have compared the outcomes of patients with liver-limited BRAF V600E-mutated colorectal liver metastases (CRLMs) managed with resection versus systemic therapy alone, and these have reported contradictory findings. METHODS: In this observational, international, multicentre study, patients with liver-limited BRAF V600E-mutated CRLMs treated with resection or systemic therapy alone were identified from institutional databases. Patterns of recurrence/progression and overall survival were compared using multivariable analyses of the entire cohort and a propensity score-matched cohort. RESULTS: Of 170 patients included, 119 underwent hepatectomy and 51 received systemic treatment. Surgically treated patients had a more favourable pattern of recurrence with most recurrences limited to a single site, whereas diffuse progression was more common among patients who received systemic treatment (19 versus 44%; P = 0.002). Surgically treated patients had longer median overall survival (35 versus 20 months; P < 0.001). Hepatectomy was independently associated with better OS than systemic treatment alone (HR 0.37, 95% c.i. 0.21 to 0.65). In the propensity score-matched cohort, surgically treated patients had longer median overall survival (28 versus 20 months; P < 0.001); hepatectomy was independently associated with better overall survival (HR 0.47, 0.25 to 0.88). CONCLUSION: BRAF V600E mutation should not be considered a contraindication to surgery for patients with resectable, liver-only CRLMs.

The impact of adrenocortical carcinoma hormone secreting status as a predictor of poor survival: a systematic review and meta-analysis.

PURPOSE: Adrenocortical carcinoma (ACC) poses a significant challenge in healthcare due to its aggressive nature and rarity. Prior reports suggest a poorer prognosis associated with hormone-secreting neoplasms. This study aims to assess the impact of ACC hormonal status on patients' oncologic survival. METHODS: A comprehensive literature search of the Medline, Embase, Web of Science, CINAHL, CENTRAL and clinicaltrials.gov databases was undertaken. Utilized data involved Hazard Ratios derived from multivariable analysis in order to minimize exposure to confounding bias. Included studies were subsequently meta-analyzed using a Random effects model. RESULTS: Twelve studies incorporating 4483 patients were included in the quantitative analysis. Hormonally active ACCs comprised 48% of the entire pooled patient cohort and were found to be associated with significantly worse Overall Survival (HR 1.57, 95% Confidence Interval 1.39-1.78, p < 0.001). Disease-Free Survival was comparably impacted (HR 1.32, 95% CI 1.11-1.57, p < 0.001). Furthermore, cortisol secreting ACCs specifically, were also found to be associated with a 48% increase in the hazard of death or disease recurrence. Interstudy statistical heterogeneity was minimal among evaluated outcomes. CONCLUSIONS: Hormone-producing ACCs exhibit a poorer prognosis compared to non-secreting counterparts, with a 57% increased risk of death and a 32% increased risk of recurrence. These findings support the hypothesis that hormone production signifies an adverse tumor-specific feature, particularly when leading to hypercortisolemia, indicating an aggressive disease phenotype.

Demystifying BRAF Mutation Status in Colorectal Liver Metastases : A Multi-institutional, Collaborative Approach to 6 Open Clinical Questions.

OBJECTIVE: To investigate the clinical implications of BRAF -mutated (mut BRAF ) colorectal liver metastases (CRLMs). BACKGROUND: The clinical implications of mut BRAF status in CRLMs are largely unknown. METHODS: Patients undergoing resection for mut BRAF CRLM were identified from prospectively maintained registries of the collaborating institutions. Overall survival (OS) and recurrence-free survival (RFS) were compared among patients with V600E versus non-V600E mutations, KRAS/BRAF comutation versus mut BRAF alone, microsatellite stability status (Microsatellite Stable (MSS) vs instable (MSI-high)), upfront resectable versus converted tumors, extrahepatic versus liver-limited disease, and intrahepatic recurrence treated with repeat hepatectomy versus nonoperative management. RESULTS: A total of 240 patients harboring BRAF -mutated tumors were included. BRAF V600E mutation was associated with shorter OS (30.6 vs 144 mo, P =0.004), but not RFS compared with non-V600E mutations. KRAS/BRAF comutation did not affect outcomes. MSS tumors were associated with shorter RFS (9.1 vs 26 mo, P <0.001) but not OS (33.5 vs 41 mo, P =0.3) compared with MSI-high tumors, whereas patients with resected converted disease had slightly worse RFS (8 vs 11 mo, P =0.01) and similar OS (30 vs 40 mo, P =0.4) compared with those with upfront resectable disease. Patients with extrahepatic disease had worse OS compared with those with liver-limited disease (8.8 vs 40 mo, P <0.001). Repeat hepatectomy after intrahepatic recurrence was associated with improved OS compared with nonoperative management (41 vs 18.7 mo, P =0.004). All results continued to hold true in the multivariable OS analysis. CONCLUSIONS: Although surgery may be futile in patients with BRAF -mutated CRLM and concurrent extrahepatic disease, resection of converted disease resulted in encouraging survival in the absence of extrahepatic spread. Importantly, second hepatectomy in select patients with recurrence was associated with improved outcomes. Finally, MSI-high status identifies a better prognostic group, with regard to RFS while patients with non-V600E mutations have excellent prognosis.

Milder impact of the COVID-19 pandemic on the practice of orthopaedic surgery in Greece and Cyprus than other European countries.

PURPOSE: The aim of this study was to highlight the impact of the COVID-19 pandemic on the practice of orthopaedics in Greece and Cyprus. METHODS: The survey used the online questionnaire from AGA (Gesellschaft für Arthroskopie und Gelenkchirurgie; Society for Arthroscopy and Joint Surgery) to facilitate the comparison between different European countries. The questionnaire was distributed online to members of the HAOST (Hellenic Association of Orthopaedic Surgery and Trauma), the ΟΤΑΜΑΤ (Orthopaedic and Trauma Association of Macedonia and Thrace) and the CAOST (Cypriot Association of Orthopaedic Surgery and Trauma). The questionnaire consisted of 29 questions, which included demographic data, questions on the impact of the pandemic on the practice of orthopaedic surgery and questions on the impact on the personal and family life of orthopaedic surgeons. RESULTS: The questionnaire was sent to 1350 orthopaedic surgeons in Greece and Cyprus, 303 of whom responded (response rate 22.44%). 11.2% of the participants reported cancellation of overall orthopaedic procedures. According to 35.6-49.8% of the participants, arthroscopic procedures were continued. As regards elective primary arthroplasties, 35.3% of the participants reported that these continued to be performed at their hospitals. Post-operative follow-ups as well as physiotherapy were affected by the pandemic, and changes were also observed in the habits of orthopaedic surgeons in their personal and family lives. CONCLUSION: The orthopaedic service in Greece and Cyprus decreased during the first wave of the COVID-19 pandemic. Arthroscopic procedures and total joint replacements decreased significantly, but not to the same extent as in other countries. Health systems were not fully prepared for the first wave of the pandemic and the various countries took social measures at different times and to different extents. Thus, studying the impact of the pandemic on the practice of orthopaedic surgery in different countries can help health systems to better prepare for future pandemics; public health can then be shielded and hospitals can continue to provide high-quality orthopaedic care. LEVEL OF EVIDENCE: Level V.

Experiential student study groups: perspectives on medical education in the post-COVID-19 period.

BACKGROUND: Undergraduate medical curricula often fail to integrate experiential learning methodologies. Thus, a pilot series of interactive pathology lessons was designed and implemented in an attempt to promote experiential learning. METHODS: Thirty pre-graduate medical students voluntarily participated in the interactive study groups at the First Department of Pathology of the National and Kapodistrian University of Athens, Medical School. A questionnaire was designed to investigate the satisfaction of students regarding their participation in pathology study groups and to identify the characteristics that shape students' perceptions of the foundations of medical education. Descriptive statistics (mean values) were used to describe the students' evaluations of the pathology study groups, and thematic analysis was conducted to investigate the data collected using open-ended questions. RESULTS: Interactions with the professor and the option of co-observing the slides using dual-view optical microscopes and virtual slides were each evaluated as "Excellent" by ≅ 95% of the students. Four overarching themes were identified regarding the core characteristics of medical education according to the students' perspectives: 1) educational background in medical education, 2) interaction with educators in medical education, 3) educational material in medical education and 4) assessment in medical education. CONCLUSIONS: The high rates of acceptance of the pathology study groups reflect the desire and need for active learning methodologies to be implemented in modern medical education. Nearly all the students mentioned the need for practical skill acquisition, the integration of theory into practice and ethics in medical education. The success of these optional pathology study groups highlights the need for similar modalities to be incorporated into the main medical education curriculum.

The effect of hepatocyte growth factor on intestinal adaption in an experimental model of short bowel syndrome.

PURPOSE: Nowadays, the standard therapy for patients with short bowel syndrome is parenteral nutrition (PN). Various growth factors have been tested to achieve weaning from prolonged PN administration. We evaluated the effect of hepatocyte growth factor (HGF) on structural intestinal adaptation and cell proliferation in a rat model of SBS. METHODS: Thirty Sprague-Dawley rats were divided into three groups; group A rats (sham) underwent bowel transection, group B rats underwent a 75% bowel resection, and group C rats underwent the same procedure but were treated postoperatively with HGF. Histopathologic parameters of intestinal adaptation were determined, while microarray and rt-PCR analyses of ileal RNA were also performed. RESULTS: Treatment with HGF resulted in significant increase in body weight, while the jejunal and ileal villus height and crypt depth were increased in HGF rats (36%, p < 0.05 and 27%, p < 0.05 respectively). Enterocyte proliferation was also significantly increased in HGF rats (21% p < 0.05). Microarray and quantitative rt-PCR analyses showed that the genes hgfac, rac 1, cdc42, and akt 1 were more than twofold up-regulated after HGF treatment. CONCLUSION: HGF emerges as a growth factor that enhances intestinal adaptation. The future use of HGF may potentially reduce the requirement for PN in SBS patients.

GNRI as a Prognostic Factor for Outcomes in Cancer Patients: A Systematic Review of the Literature.

Oncologic patients often suffer from malnutrition which in turn, might have negative impact on treatment outcomes. The Geriatric Nutritional Risk Index (GNRI), as an index of impaired nutritional status, has emerged as a significant prognostic factor for short-and long-term outcomes in cancer patients. The aim of the current systematic review is to determine whether the GNRI is an independent prognostic factor of postoperative complications and survival in cancer patients. A systematic search was conducted to identify studies, published from 2005 to 2019, which assessed associations between GNRI and short- and long-term outcomes in cancer patients. Eighteen studies fulfilled the eligibility criteria and were included in the analysis. Low scores of GNRI were associated with increased risk for developing postoperative complications and impaired survival of cancer patients in most studies. Our findings support the use of the GNRI in the clinical practice, since it is a simple and reliable tool for assessing nutritional status in oncologic patients. More prospective, multi-centered studies are warranted to confirm the current results, as well as the role of nutritional support in improving the prognosis of cancer patients.

The interplay of KRAS mutational status with tumor laterality in non-metastatic colorectal cancer: An international, multi-institutional study in patients with known KRAS, BRAF, and MSI status.

BACKGROUND: Although the prognostic relevance of KRAS status in metastatic colorectal cancer (CRC) depends on tumor laterality, this relationship is largely unknown in non-metastatic CRC. METHODS: Patients who underwent resection for non-metastatic CRC between 2000 and 2018 were identified from institutional databases at six academic tertiary centers in Europe and Japan. The prognostic relevance of KRAS status in patients with right-sided (RS), left-sided (LS), and rectal cancers was assessed. RESULTS: Of the 1093 eligible patients, 378 had right-sided tumors and 715 had left-sided tumors. Among patients with RS tumors, the 5-year overall (OS) and recurrence-free survival (RFS) for patients with KRASmut versus wild-type tumors was not shown to differ significantly (82.2% vs. 83.2% and 72.1% vs. 76.7%, respectively, all p > .05). Among those with LS tumors, KRAS mutation was associated with shorter 5-year OS and RFS on both the univariable (OS: 79.4% vs. 86.1%, p = .004; RFS: 68.8% vs. 77.3%, p = .005) and multivariable analysis (OS: HR: 1.52, p = .019; RFS: HR: 1.32, p = .05). CONCLUSIONS: KRAS mutation status was independently prognostic among patients with LS tumors, but this association failed to reach statistical significance in RS and rectal tumors. These findings confirm reports in metastatic CRC and underline the possible biologic importance of tumor location.

Oral Nutritional Supplementation Following Upper Gastrointestinal Cancer Surgery: A Prospective Analysis Exploring Potential Barriers to Compliance.

Objective: Malnutrition is common in patients who underwent upper gastrointestinal cancer surgery. Our goal was to explore postoperative compliance with oral nutritional supplementation and define barriers to consumption in patients with esophageal, gastroesophageal junction, and gastric cancer.Methods: Participants were prospectively recruited from September 2015 to November 2018. Preoperative nutritional status was assessed using the Patient Generated Subjective Global Assessment. Malnourished patients and patients at risk for malnutrition were offered oral nutritional supplementation at the time of hospital discharge. Compliance was evaluated 1 month after hospital discharge.Results: A total of 78 patients were analyzed. Mean patient age was 62.8 ± 10.7 years and 83.3% were males. Εsophagectomy and gastrectomy were performed in 60.3% and 39.7% of the patients respectively. Twenty-eight (35.9%) participants reported consuming all prescribed supplements, whereas 50 (64.1%) patients were noncompliant with their prescribed oral nutritional supplementation regimen. The main barriers to oral nutritional supplementation compliance were bloating (compliant vs. noncompliant patients: 17.9% vs. 58%, p < 0.001), early satiety (compliant vs. noncompliant patients: 25% vs. 52.32%, p < 0.001), flavor or texture dislike (compliant vs. noncompliant patients: 7.1% vs. 34%, p < 0.001), and diarrhea (compliant vs. noncompliant patients: 10.7% vs. 24%, p < 0.001). No other statistically significant differences were identified between the two groups.Conclusions: Postoperative compliance to oral nutritional supplementation is low in patients who underwent upper gastrointestinal cancer surgery. Patient education and support as well as providing a range of oral nutrition supplement flavors, texture, and compositions may be useful in increasing adherence to oral nutritional supplementation regimens.

The impact of preoperative sarcopenia on postoperative complications following esophagectomy for esophageal neoplasia: a systematic review and meta-analysis.

Esophageal cancer is characterized by profound changes in body composition due to dysphagia and generalized cachexia. Sarcopenia or muscle wasting is a component of cachexia associated with poor postoperative performance status. The skeletal muscle index (SMI) calculated by computed tomography scans at the level of the third lumbar vertebra is an easily quantifiable and reproducible measure of sarcopenia. The aim of this meta-analysis is to investigate the impact of preoperative sarcopenia (low SMI) on postoperative complications after esophagectomy for neoplastic lesions. In this context, a comprehensive literature search was undertaken to identify studies reporting short-term postoperative outcomes in relation to their preoperative SMI values. Cumulative risk ratios (RR) and risk differences (RD) and their respective 95% confidence intervals (CIs) were calculated using a random-effect model. A total of 11 studies incorporating 1,979 total patients (964 patients with sarcopeniaversus 1,015 without sarcopenia) were included in the final analysis. The results demonstrated a significant increase in overall morbidity (RR 1.16, 95% CI 1.01-1.33), respiratory complications (RR 1.64, 95% CI 1.21-2.22) and anastomotic leaks (RR 1.39, 95% CI 1.10-1.76) in patients with sarcopenia. No statistically significant difference was noted in overall mortality (RD 0, 95% CI -0.02-0.02) or Clavien-Dindo grade III or greater complications (RR 1.17, 95% CI 0.96-1.42). The above results demonstrate the validity of the SMI as a predictive factor for post-esophagectomy complications. Although the risk associated with sarcopenia is not prohibitive for surgery, patients with low SMI require closer vigilance during their postoperative course due to the increased propensity for respiratory and anastomotic complications.

Emergency inguinal hernioplasties in a tertiary public Hospital in Athens Greece, during the economic crisis.

BACKGROUND: Although the effect of the recent Greek economic crisis and austerity on the population's health and the health system effectiveness have been discussed a lot recently, data on common surgical conditions affecting large part of the population are missing. Using inguinal hernia as a model we investigated possible changes of citizens' attitude regarding the time of referral, the perioperative details and the intraoperative findings of the emergency hernioplasties. METHODS: The present retrospective study was conducted by a Department of Surgery in a tertiary public hospital of the Greek capital. We reviewed the records of all hernioplasties performed during two 5-year periods: 2005-2009 and 2012-2016, i.e. before and during the crisis focusing on the emergency ones (either incarcerated or strangulated). RESULTS: An equal number of hernioplasties was performed in both periods. During the crisis however, an emergency hernioplasty was significantly more probable (HR 1.269, 95% CI 1.108-1.1454, p = 0.001), at a younger age (p = 0.04), mainly in patients younger than 75 years old (p = 0.0013). More patients presented with intestinal ischemia (7 vs 18, p = 0.002), requiring longer hospitalization (5.2 vs 9.6 days, p = 0.04), with higher cost (560 ± 262.4€ vs 2125 ± 1180.8€ p < 0.001). In contrast the percentage of patients with intestinal resection, their hospitalization length and treatment-cost remained unchanged. During the crisis there was a non-significant increase of emergency patients requiring ICU postoperatively (0 vs 4, p = 0.07) and a non-significant 60% increase of emergency operations in migrants/refugees population (3.5% vs 5.8%, p = 0.28). Epidural anesthesia was significantly more frequent during the crisis. CONCLUSION: During the crisis: (i) the emergency hernioplasties increased significantly, (ii) more patients (exclusively Greek) presented with intestinal ischemia requiring longer hospitalization and higher treatment cost, (iii) the mean age of the urgently treated patients decreased significantly (iv) regional (epidural) anesthesia was more frequent. Although a direct causal relation could not be proven by the present study most observations can be explained by an increase of the patients who delayed the elective treatment of their hernia, and by a redistribution of the surgical workload towards big central hospitals. This can be prevented by adequately supporting the small district hospitals.

KRAS mutational status impacts pathologic response to pre-hepatectomy chemotherapy: a study from the International Genetic Consortium for Liver Metastases.

BACKGROUND: A major response to pre-hepatectomy chemotherapy has been associated with improved survival in patients who undergo resection of colorectal liver metastases (CRLM). However, the role of tumor biology, as exemplified by overall and codon-specific KRAS mutational status, in predicting response to chemotherapy is not well defined. METHODS: Pathologic response was characterized as minor or major depending on the percentage of remnant viable cells (>50% vs <50%, respectively). Multivariable logistic regression was used to identify factors associated with major response. RESULTS: 319 patients met inclusion criteria. 229 patients had a KRAS wild-type (wtKRAS) tumor and 90 harbored KRAS mutations (mutKRAS). A major pathologic response was more commonly noted in patients with wtKRAS compared to mutKRAS (48.5% vs 33.3%, P = 0.01) and wtKRAS status remained independently associated with a major response (P = 0.04). On a codon-specific level, major pathologic response occurred less frequently in those with codon 13 mutations (17.7%) compared to those with codon 12 (35.4%), and other KRAS mutations (33.3%). Importantly, codon 13 mutations were independently associated with minor pathologic response (P = 0.023). CONCLUSIONS: Patients with wtKRAS tumors appear to have the highest likelihood of experiencing a major response after preoperative chemotherapy. Future studies in "all-comer" cohorts are needed to confirm these findings and further investigate the response of codon 13 mutations.

The Prognostic Impact of Determining Resection Margin Status for Multiple Colorectal Metastases According to the Margin of the Largest Lesion.

BACKGROUND: Although the prognostic role of surgical margin status after resection of colorectal liver metastasis (CRLM) has been previously examined, controversy still surrounds the importance of surgical margin status in patients with multiple tumors. METHODS: Patients who underwent curative-intent surgery for CRLM from 2000 to 2015 and who presented with multiple tumors were identified. Patients with R1 resection status determined by the closest resection margin of the non-largest tumor were classified as R1-Type 1; patients with R1 status determined by the resection margin of the largest tumor were defined as R1-Type 2. Data regarding surgical margin status, size of tumors, and overall survival (OS) were collected and assessed. RESULTS: A total of 251 patients met inclusion criteria; 156 patients (62.2%) had a negative margin (R0), 50 had an R1-type 1 (19.9%), and 45 had an R1-type 2 (17.9%) margin. Median and 5-year OS in the entire cohort was 56.4 months and 48.0%, respectively. When all R1 (Type 1 + Type 2) patients were compared with R0 patients, an R1 was not associated with worse prognosis (P = 0.05). In contrast, when R1-type 2 patients were compared with R0 patients, an R1 was strongly associated with worse OS (P = 0.009). On multivariate analysis, although the prognostic impact of all R1 was not associated with OS (hazard ratio [HR] 1.56; P = 0.08), R1-Type 2 margin status independently predicted a poor outcome (HR 1.93; P = 0.03). CONCLUSIONS: The impact of margin status varied according to the size of the tumor assessed. While R1 margin status defined according to the non-largest tumor was not associated with OS, R1 margin status relative to the largest index lesion was associated with prognosis.

The beneficial role of simultaneous splenectomy after extended hepatectomy: experimental study in pigs.

BACKGROUND: The role of hepatic hemodynamic modulation in the development of "small-for-size" syndrome (SFSS) after extended hepatectomy (EH) or living-donor liver transplantation is still controversial. We have designed an experimental study to investigate the effect of hemodynamic parameters of the liver circulation on the development of SFSS after EH in a porcine model. METHODS: Eighteen pigs were randomly divided into two groups: group A has received EH (75%-80%) without splenectomy, and group B with EH and simultaneous splenectomy was carried out. Portal hemodynamics, liver function tests, histologic findings, injury and survival rates were compared between groups A and B. RESULTS: The 7-d survival rate in the splenectomy group was significantly improved compared with group A (88.9% versus 44.4%, P < 0.05). Portal vein pressure, portal vein flow, and liver function tests in the splenectomy group were significantly lower than in group A immediately after splenectomy and postoperatively until the day of sacrifice. Histologic findings in group A clearly illustrate severe inflammation, bridging necrosis, ischemic cholangitis, and severe congestion, while in group B there were less serious histologic changes. CONCLUSIONS: Our experimental study indicates that perioperative portal modulation can successfully prevent the manifestation of SFSS after EH. Therefore, by focusing on "flow" rather than on "size," researchers may understand better the pathophysiology of this syndrome.

The prognostic implications of primary colorectal tumor location on recurrence and overall survival in patients undergoing resection for colorectal liver metastasis.

BACKGROUND AND OBJECTIVES: The prognostic impact of primary colorectal cancer (CRC) location following resection of colorectal liver metastasis (CRLM) remains largely unknown. We sought to characterize the prognostic implications of primary tumor location among patients who underwent curative-intent hepatectomy for CRLM. METHODS: Tumors of the cecum, ascending, and transverse colon were defined as right-sided; tumors of the sigmoid flexure, descending, and sigmoid colon were defined as left-sided. Clinicopathologic and long-term survival data were collected and assessed using univariable and multivariable analyses. RESULTS: About 475 patients who underwent CRLM resection at a single institution were included; most patients had left-sided tumors (n = 284). Median and 5-year RFS was 20.2 months and 28.0%, respectively. Patients who had a left-sided primary tumor had a shorter RFS compared with patients who had a right-sided tumor (P = 0.01). Although site of and time to recurrence did not differ between the two groups (P > 0.05), patients with right-sided primary tumors were more likely to recur with advanced disease (i.e., ≥4 recurrent lesions) (P < 0.01). In turn, patients with right-sided tumors had both worse OS (P = 0.03) and worse survival after recurrence (P = 0.01). CONCLUSION: While patients with right-sided tumors experienced longer RFS, when these patients did recur following CRLM resection, disease extent was more advanced. In turn, OS following recurrence was shorter among patients with right-sided CRC. J. Surg. Oncol. 2016;114:803-809. © 2016 2016 Wiley Periodicals, Inc.

Extended hepatectomy using the bipolar tissue sealer: an experimental model of small-for-size syndrome in pigs.

PURPOSE: After liver transplantation with a small-for-size liver graft or after extensive hepatectomy for liver malignancies or other non malignant conditions with an insufficient liver volume, the survival of patients depends on liver regeneration. This study was carried out in order to create a new porcine model for the study of small-for-size syndrome (SFSS) after extensive hepatectomy. METHODS: In the present study we used 23 domestic Landrace pigs weighing 28.3±3 kg and aged 19-21 weeks. We describe our detailed surgical procedure for 75% partial hepatectomy a in porcine model, using the saline-coupled bipolar sealing device (Aquamantys®) for hepatectomy. RESULTS: The Aquamantis 2.3 bipolar sealer was connected to the Aquamantis generator and was adjusted to produce 150 watts at a medium flow rate of 20 ml/min. The device temperature was programmed to remain at approximately 100° C and, as a consequence, it produced a tissue ablation without charring. The mean operating time was 153.8 min and the mean blood loss 81.9 ml. The estimated residual liver weight (ERL) was 177 g, whereas the mean proportion of ERL was 24.5%. There was no perioperative mortality. CONCLUSIONS: A large animal model, such as pig, is extremely useful in order to reproduce and understand the SFSS. Our simple technique for successful resection of 75% of the liver in pigs, using the Aquamantys system, achieves effective and safe liver parenchymal transection with significant decrease of intraoperative blood loss and can provide useful information for researchers.

Microwave versus saline-linked radiofrequency (Aquamantys) assisted liver resection in a porcine liver resection model. A safety and feasibility pilot study.

PURPOSE: The aim of this study was to compare the feasibility, efficacy and safety of microwave ablation and saline-linked radiofrequency (Aquamantys) in liver resection. METHODS: Sixteen domestic pigs (8 per group) underwent thermoablations. Group A consisted of 8 pigs in which microwave left lateral liver resection was performed. Group B consisted of 8 pigs which underwent left lateral liver resection by the Aquamantys system. After 28 days of close follow-up, the animals were sacrificed in order to study the macroscopic and microscopic findings of each intervention on the liver edge. RESULTS: An average of 47.13 min was enough for the entire operation to take place using Aquamantys, whereas an average of 59.13 min was needed in the microwave liver resection group. Mean blood loss was 40 ml (range 5-85) with Aquamantys whereas mean blood loss was 72.37 ml (range 42-100) using microwave. Postoperative complications rates were extremely low in both groups. There was no intra- or postoperative mortality. CONCLUSIONS: Our study demonstrated that left lateral liver resection using Aquamantys system is technically feasible in the porcine model and proved to be highly effective and a safer hemostatic method compared to microwave ablation.