Prognostic Value of Serum α-Fetoprotein Level as an Important Characteristic of Tumor Biology for Patients Undergoing Liver Resection of Early-Stage Hepatocellular Carcinoma (BCLC Stage 0/A): A Large Multicenter Analysis.

BACKGROUND AND OBJECTIVE: According to the Barcelona Clinic Liver Cancer (BCLC) algorithm, tumor burden and liver function, but not tumor biology, are the key factors in determining tumor staging and treatment modality, and evaluating treatment prognosis. The serum α-fetoprotein (AFP) level is an important characteristic of hepatocellular carcinoma (HCC) biology, and we aimed to evaluate its prognostic value for patients undergoing liver resection of early-stage HCC. METHODS: Patients who underwent curative liver resection for early-stage HCC were identified from a multi-institutional database. Patients were divided into three groups according to preoperative AFP levels: low (< 400 ng/mL), high (400-999 ng/mL), and extremely-high (≥ 1000 ng/mL) AFP groups. Overall survival (OS) and recurrence rates were compared among these three groups. RESULTS: Among 1284 patients, 720 (56.1%), 262 (20.4%), and 302 (23.5%) patients had preoperative low, high, and extremely-high AFP levels, respectively. The cumulative 5-year OS and recurrence rates were 71.3 and 38.9% among patients in the low AFP group, 66.3 and 48.5% in the high AFP group, and 45.7 and 67.2% in the extremely-high AFP group, respectively (both p < 0.001). Multivariate Cox regression analysis identified both high and extremely-high AFP levels to be independent risk factors of OS (hazard ratio [HR] 1.275 and 1.978, 95% confidence interval [CI] 1.004-1.620 and 1.588-2.464, respectively; p = 0.047 and p < 0.001, respectively) and recurrence (HR 1.290 and 2.050, 95% CI 1.047-1.588 and 1.692-2.484, respectively; p = 0.017 and p < 0.001, respectively). CONCLUSIONS: This study demonstrated the important prognostic value of preoperative AFP levels among patients undergoing resection for early-stage HCC. Incorporating AFP to prognostic estimation of the BCLC algorithm can help guide individualized risk stratification and identify neoadjuvant/adjuvant treatment necessity.

Assessment of cellular responses in three-dimensional cell cultures through chemical exchange saturation transfer and 1 H MRS.

The article from this special issue was previously published in NMR In Biomedicine , Volume 35, Issue 9, 2022. For completeness we are including the title page of the article below. The full text of the article can be read in Issue 35:9 on Wiley Online Library: https://doi.org/10.1002/nbm.4757.

Tumor burden score-AFP-albumin-bilirubin grade score predicts the survival of patients with hepatocellular carcinoma after liver resection.

PURPOSE: There is little information regarding the overall survival (OS) predictive ability of the combination of tumor burden score (TBS), α-fetoprotein (AFP), and albumin-bilirubin (ALBI) grade for patients with hepatocellular carcinoma (HCC). Here, we aimed to develop a model including TBS, AFP, and ALBI grade to predict HCC patient OS following liver resection. METHODS: Patients (N = 1556) from six centers were randomly divided 1:1 into training and validation sets. The X-Tile software was used to determine the optimal cutoff values. The time-dependent area under the receiver operating characteristic curve (AUROC) was calculated to assess the prognostic ability of the different models. RESULTS: In the training set, tumor differentiation, TBS, AFP, ALBI grade, and Barcelona Clinic Liver Cancer (BCLC) stage were independently related to OS. According to the coefficient values of TBS, AFP, and ALBI grade, we developed the TBS-AFP-ALBI (TAA) score using a simplified point system (0, 2 for low/high TBS, 0, 1 for low/high AFP and 0,1 for ALBI grade 1/2). Patients were further divided into low TAA (TAA ≤ 1), medium TAA (TAA = 2-3), and high TAA (TAA= 4) groups. TAA scores (low: referent; medium, HR = 1.994, 95% CI = 1.492-2.666; high, HR = 2.413, 95% CI = 1.630-3.573) were independently associated with patient survival in the validation set. The TAA scores showed higher AUROCs than BCLC stage for the prediction of 1-, 3-, and 5-year OS in both the training and validation sets. CONCLUSION: TAA is a simple score that has better OS prediction performance than the BCLC stage in predicting OS for HCC patients after liver resection.

Prospective validation of the Eastern Staging in predicting survival after surgical resection for patients with hepatocellular carcinoma: a multicenter study from China.

BACKGROUND: The Eastern Staging System, which was specially developed for patients undergoing surgical resection for hepatocellular carcinoma (HCC), has been proposed for more than ten years. To prospectively validate the predictive accuracy of the Eastern staging on long-term survival after HCC resection. METHODS: Patients who underwent hepatectomy for HCC from 2011 to 2020 at 10 Chinese hospitals were identified from a prospectively collected database. The survival predictive accuracy was evaluated and compared between the Eastern Staging with six other staging systems, including the JIS, BCLC, Okuda, CLIP, 8th AJCC TNM, and HKLC staging. RESULTS: Among 2365 patients, the 1-, 3-, and 5-year overall survival rates were 84.2%, 64.5%, and 52.6%, respectively. Among these seven staging systems, the Eastern staging was associated with the best monotonicity of gradients (linear trend χ2: 408.5) and homogeneity (likelihood ratio χ2: 447.3), and the highest discriminatory ability (the areas under curves for 1-, 3-, and 5-year mortality: 0.776, 0.787, and 0.768, respectively). In addition, the Eastern staging was the most informative staging system in predicting survival (Akaike information criterion: 2982.33). CONCLUSION: Using a large multicenter prospectively collected database, the Eastern Staging was found to show the best predictive accuracy on long-term overall survival in patients with resectable HCC than the other 6 commonly-used staging systems.

Clinical Features of Recurrence After Hepatic Resection for Early-Stage Hepatocellular Carcinoma and Long-Term Survival Outcomes of Patients with Recurrence: A Multi-institutional Analysis.

BACKGROUND: A potentially curative hepatic resection is the optimal treatment for hepatocellular carcinoma (HCC), but most HCCs, even at an early stage, eventually recur after resection. This study investigates clinical features of initial recurrence and long-term prognosis of patients with recurrence after curative resection for early-stage HCC. PATIENTS AND METHODS: From a multicenter database, patients who underwent curative hepatic resection for early-stage HCC [Barcelona Clinic Liver Cancer (BCLC) stage 0/A] were extracted. Time to initial recurrence, patterns of initial recurrence, and treatment modalities for recurrent tumors were investigated. Univariate and multivariate analysis were used to identify independent risks associated with postoperative recurrence, as well as post-recurrence survival (PRS) for patients with recurrence. RESULTS: Among 1424 patients, 679 (47.7%) developed recurrence at a median follow-up of 54.8 months, including 408 (60.1%) early recurrence (≤ 2 years after surgery) and 271 (39.9%) late recurrence (> 2 years). Independent risks of postoperative recurrence included cirrhosis, preoperative alpha-fetoprotein level > 400 ug/L, tumor size > 5 cm, multiple tumors, satellites, microvascular invasion, and intraoperative blood transfusion. Multivariate analysis revealed that receiving irregular recurrence surveillance, initial tumor beyond Milan criteria, early recurrence, BCLC stage B/C of the recurrent tumor, and noncurative treatments were independently associated with poorer PRS. CONCLUSIONS: Nearly half of patients with early-stage HCC experienced recurrence after resection. Understanding recurrence risks may help identify patients at high risk of recurrence who may benefit from future adjuvant therapies. Meaningful survival even after recurrence can still be achieved by postoperative regular surveillance and curative treatment.

Association of Preoperative Body Mass Index with Surgical Textbook Outcomes Following Hepatectomy for Hepatocellular Carcinoma: A Multicenter Study of 1206 Patients.

BACKGROUND: Assessment of quality in the perioperative period is critical to ensure good patient care. Textbook outcomes (TO) have been proposed to combine several parameters into a single defined quality metric. The association of preoperative body mass index (BMI) with incidences of achieving or not achieving TO (non-TO) among patients undergoing hepatectomy for hepatocellular carcinoma (HCC) was characterized. METHODS: Patients who underwent curative-intent hepatectomy for HCC between 2015 and 2018 were identified from a multicenter database. These patients were divided into three groups based on preoperative BMI: low-BMI (≤ 18.4 kg/m2), normal-BMI (18.5-24.9 kg/m2), and high-BMI (≥ 25.0 kg/m2). The incidences of non-TO among these three groups were compared. Multivariate analyses were performed to identify whether there was any independent association between preoperative BMI and non-TO. RESULTS: Among 1206 patients, 100 (8.3%), 660 (54.7%), and 446 (37.0%) were in the low-BMI, normal-BMI, and high-BMI groups, respectively. The incidence of non-TO was 65.6% in the whole cohort. The incidence of non-TO was significantly higher among patients in the low- and high-BMI cohorts versus the normal-BMI cohort (75.0% and 74.7% versus 58.0%, both P < 0.01). After adjustment of other confounding factors on multivariate analysis, low-BMI and high-BMI were independently associated with higher incidences of non-TO compared with normal-BMI (OR: 1.98 and 2.27, both P < 0.05). CONCLUSIONS: Two out of three patients did not achieve TO after hepatectomy for HCC. Both preoperative low-BMI and high-BMI were independently associated with lower odds to achieve optimal TO following HCC resection.

Assessment of cellular responses in three-dimensional cell cultures through chemical exchange saturation transfer and 1 H MRS.

Metabolic responses to physiological changes have been detected using chemical exchange saturation transfer (CEST) imaging in clinical settings. Similarly to other MRI techniques, the CEST technique was based originally on phantoms from buffer solutions and was then further developed through animal experiments. However, CEST imaging can capture certain dynamics of metabolism that solution phantoms cannot model. Cell culture phantoms can fill the gap between buffer phantoms and animal models. In this study, we used 1 H NMR and CEST in a B0 field of 9.4 T to investigate HEK293T cells from two-dimensional (2D) cultures, three-dimensional (3D) cultures, and 3D cultures seeded with cell spheroids. Two CEST dips were observed: the magnitude of the amine dip at 2.8 ppm increased during the incubation period, whereas the hydroxyl dip at 1.2 ppm remained approximately the same or modestly increased. We also observed a CEST dip at 2.8 ppm from the 2D culture responding dramatically to doxorubicin treatment. By cross-validating with pH values and the concentrations of amine and hydroxyl protons extracted through 1 H NMR, we observed that they did not correspond to an increase in the amine pool. We believe that the denaturation or degradation of proteins from the fetal bovine serum increased the size of the amine pool. Although 3D culture conditions can be further improved, our study suggests that 3D cultures have the potential to bridge studies of solution phantoms and those on animals.

Long-term survival and recurrence after curative resection for hepatocellular carcinoma in patients with chronic hepatitis C virus infection: a multicenter observational study from China.

BACKGROUND: Hepatocellular carcinoma (HCC) is a recognized sequalae of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. This study aimed to identify long-term survival and prognostic factors after curative resection for HCC among patients with chronic HCV infection. METHODS: From a Chinese multicenter database, the data of consecutive patients with HCV infection undergoing curative liver resection for initial HCC between 2006 and 2015 were retrospectively reviewed. Postoperative 30-day mortality and morbidity, long-term overall survival (OS) and recurrence-free survival (RFS) were evaluated. RESULTS: Among 382 HCC patients with HCV infection, 68 (18%) had concurrent HBV infection and 110 (29%) had portal hypertension. Postoperative 30-day morbidity and mortality rates were 45% and 2.9%, respectively. The 5-year OS and RFS rates were 45% and 34%, respectively. Multivariable Cox-regression analyses identified that concurrent HBV infection, presence of portal hypertension, largest tumor size > 5 cm, and macrovascular and microvascular invasion were independently associated with worse OS and RFS, while postoperative regular anti-HCV therapy was independently associated with better OS. CONCLUSION: Long-term prognosis after HCC resection among patients with HCV infection was worse in those with concurrent HBV infection and concomitant portal hypertension. Postoperative regular anti-HCV therapy was associated with better OS.

Multicenter analysis of long-term oncologic outcomes of hepatectomy for elderly patients with hepatocellular carcinoma.

BACKGROUND: Aging of the population and prolonged life expectancy have significantly increased the number of elderly patients undergoing hepatectomy for hepatocellular carcinoma (HCC). However, potential benefits, especially long-term oncologic outcomes of hepatectomy for elderly patients with HCC remain unclear. METHOD: Patients treated with curative-intent hepatectomy for HCC in 8 Chinese hospitals were enrolled. Patients were divided into the elderly (≥70 years old) and younger (<70 years old) groups. Overall survival (OS), cancer-specific survival (CSS), and time-to-recurrence (TTR) were compared. Risk factors of CSS and TTR were evaluated by univariable and multivariable competing-risk regression analyses. RESULTS: Of 2134 patients, 259 (12.1%) and 1875 (87.9%) were elderly and younger aged, respectively. Postoperative 30-day and 90-day mortality was comparable among elderly and younger patients. Compared with younger patients, the elderly had a worse 5-year OS (49.4% vs. 55.3%, P = 0.032), yet a better 5-year CCS (74.5% vs. 61.0%, P = 0.005) and a lower 5-year TTR (33.7% vs. 44.9%, P < 0.001), respectively. Multivariable analyses identified that elder age was independently associated with more favorable CSS (HR 0.74, 95%CI 0.58-0.90, P = 0.011) and TTR (0.69, 0.53-0.88, P < 0.001) but was not associated with OS (P = 0.136). CONCLUSIONS: Age by itself is not a contraindication to surgery, and selected elderly patients with HCC can benefit from hepatectomy. Compared with younger patients, elderly patients have noninferior oncologic outcomes following hepatectomy for HCC.

Association between body mass index and postoperative morbidity after liver resection of hepatocellular carcinoma: A multicenter study of 1,324 patients.

BACKGROUND: Morbidity remains a common problem following hepatic resection. The aim of this study was to investigate the association between preoperative body mass index (BMI) and morbidity in patients undergoing liver resection for hepatocellular carcinoma (HCC). METHODS: Patients were divided into three groups according to preoperative BMI: low-BMI (≤18.4 kg/m2), normal-BMI (18.5-24.9 kg/m2) and high-BMI (≥25.0 kg/m2). Baseline characteristics, operative variables, postoperative 30-day mortality and morbidity were compared. Univariable and multivariable analyses were performed to identify independent risk factors associated with postoperative morbidity. RESULTS: Among 1324 patients, 108 (8.2%), 733 (55.4%), and 483 (36.5%) were low-BMI, normal-BMI, and high-BMI, respectively. There were no differences in postoperative 30-day mortality among patients based on BMI (P = 0.199). Postoperative 30-day morbidity was, however, higher in low-BMI and high-BMI patients versus patients with a normal-BMI (33.3% and 32.1% vs. 22.9%, P = 0.018 and P < 0.001, respectively). Following multivariable analysis low-BMI and high-BMI remained independently associated with an increased risk of postoperative morbidity (OR: 1.701, 95%CI: 1.060-2.729, P = 0.028, and OR: 1.491, 95%CI: 1.131-1.966, P = 0.005, respectively). Similar results were noted in the incidence of postoperative 30-day surgical site infection (SSI). CONCLUSION: Compared with normal-BMI patients, low-BMI and high-BMI patients had higher postoperative morbidity, including a higher incidence of SSI after liver resection for HCC.

Defining and predicting early recurrence after liver resection of hepatocellular carcinoma: a multi-institutional study.

BACKGROUND: A clear definition of "early recurrence" after hepatocellular carcinoma (HCC) resection is still lacking. This study aimed to determine the optimal cutoff between early and late HCC recurrence, and develop nomograms for pre- and postoperative prediction of early recurrence. METHODS: Patients undergoing HCC resection were identified from a multi-institutional Chinese database. Minimum P-value approach was adopted to calculate optimal cut-off to define early recurrence. Pre- and postoperative risk factors for early recurrence were identified and further used for nomogram construction. The results were externally validated by a Western cohort. RESULTS: Among 1501 patients identified, 539 (35.9%) were recurrence-free. The optimal length to distinguish between early (n = 340, 35.3%) and late recurrence (n = 622, 64.7%) was 8 months. Multivariable logistic regression analyses identified 5 preoperative and 8 postoperative factors for early recurrence, which were further incorporated into preoperative and postoperative nomograms (C-index: 0.785 and 0.834). The calibration plots for the probability of early recurrence fitted well. The nomogram performance was maintained using the validation dataset (C-index: 0.777 for preoperative prediction and 0.842 for postoperative prediction). CONCLUSIONS: An interval of 8 months was the optimal threshold for defining early HCC recurrence. The two web-based nomograms have been published to allow accurate pre- and postoperative prediction of early recurrence. These may offer useful guidance for individual treatment or follow up for patients with resectable HCC.

Long-Term Survival Outcomes After Liver Resection for Binodular Hepatocellular Carcinoma: A Multicenter Cohort Study.

BACKGROUND: The long-term prognosis after liver resection for multinodular (≥3 nodules) hepatocellular carcinoma (HCC) is generally considered to be unfavorable. However, the role of liver resection for binodular HCC is less investigated. SUBJECTS, MATERIALS, AND METHODS: From a multicenter database, consecutive patients who underwent curative-intent liver resection for binodular HCC and without macrovascular invasion between 2003 and 2015 were retrospectively reviewed. Patients' clinical variables as well as perioperative and long-term survival outcomes were analyzed. Univariable and multivariable analyses were performed to identify the risk factors associated with overall survival (OS) and recurrence-free survival (RFS) after curative resection. RESULTS: Of 263 enrolled patients, the perioperative 30-day mortality and morbidity rates were 1.5% and 28.5%. The 1-, 3-, and 5-year OS and RFS rates were 81.5%, 52.4%, and 39.1% and 57.1%, 35.8%, and 26.6%, respectively. Multivariable Cox-regression analyses identified preoperative alpha-fetoprotein level >400 µg/L, tumor size with a sum of two nodules >8 cm, tumor size ratio of large/small nodule >1.5 (asymmetrical proportion), unilateral hemiliver distribution of two nodules, distance of ≤3 cm between two nodules, and microvascular invasion in any nodule as independent risk factors associated with decreased OS and RFS. CONCLUSION: Liver resection was safe and feasible in patients with binodular HCC, with acceptable perioperative and long-term outcomes. Sum of two tumor sizes, size ratio and distribution, and distance between two nodules were independent risk factors associated with long-term survival outcomes after surgery. These results may guide clinicians to make individualized surgical decisions and estimate long-term prognosis for these patients. IMPLICATIONS FOR PRACTICE: Liver resection was safe and feasible in patients with binodular hepatocellular carcinoma, with acceptable perioperative and long-term outcomes. The sum of two tumor sizes, the size ratio and distribution of the two nodules, and the distance between two nodules were independent risk factors associated with long-term overall survival and recurrence-free survival after liver resection. The results of this study may guide clinicians to make individualized surgical decisions, estimate long-term prognosis, and plan recurrence surveillance and adjuvant therapy for these patients.

Preoperative prealbumin level as an independent predictor of long-term prognosis after liver resection for hepatocellular carcinoma: a multi-institutional study.

BACKGROUND: Serum prealbumin is a sensitive and stable marker for nutritional status and liver function. Whether preoperative prealbumin level is associated with long-term prognosis in patients undergoing liver resection for hepatocellular carcinoma (HCC) is unclear. METHODS: Patients who underwent liver resection for HCC between 2001 and 2014 at six institutions were enrolled. These patients were divided into the low and normal prealbumin groups using a cut-off value of 170 mg/L for preoperative prealbumin level. The overall survival (OS) and recurrence-free survival (RFS) were compared between them. RESULTS: In 1483 patients, 437 (29%) had a low prealbumin level. The 3- and 5-year OS and RFS rates of patients in the low-prealbumin group were 57 and 31%, and 40 and 20%, respectively, which were significantly poorer than those in the normal-prealbumin group (76 and 43%, and 56 and 28%, respectively, both p < 0.001). Multivariable Cox-regression analyses revealed that preoperative prealbumin level was an independent predictor of OS (HR, 1.45, 95% CI: 1.24-1.70, p <0.001) and RFS (HR, 1.28, 95% CI: 1.10-1.48, p <0.001). CONCLUSIONS: Preoperative prealbumin level could be used in predicting long-term prognosis for patients undergoing liver resection for HCC.

The impact of resection margin and microvascular invasion on long-term prognosis after curative resection of hepatocellular carcinoma: a multi-institutional study.

BACKGROUND: The resection margin (RM) status and microscopic vascular invasion (MVI) are known prognostic factors for hepatocellular carcinoma (HCC). An enhanced understanding of their impact on long-term prognosis is required to improve oncological outcomes. METHODS: Using multi-institutional data, the different impact of the RM status (narrow, <1 cm, or wide, ≥1 cm) and MVI (positive or negative) on overall survival (OS) and recurrence-free survival (RFS) after curative liver resection of solitary HCC without macrovascular invasion was analyzed. RESULTS: In 801 patients, 306 (38%) had a narrow RM and 352 (44%) had positive MVI. The median OS and RFS were 109.8 and 74.8 months in patients with wide RM & negative MVI, 93.5 and 53.1 months with wide RM & positive MVI, 79.2 and 41.6 months with narrow RM & negative MVI, and 69.2 and 37.5 months with narrow RM & positive MVI (both P < 0.01). On multivariable analyses, narrow RM & positive MVI had the highest hazard ratio with reduced OS and RFS (HR 2.96, 95% CI 2.11-4.17, and HR 3.15, 95% CI, 2.09-4.67, respectively). CONCLUSIONS: Concomitant having narrow RM and positive MVI increases the risks of postoperative death and recurrence by about 2-fold in patients with solitary HCC.

A systematic review comparing outcomes of surgical resection and non-surgical treatments for patients with hepatocellular carcinoma and portal vein tumor thrombus.

BACKGROUND: The prognosis of patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT) is very poor. According to most HCC guidelines, sorafenib, transarterial chemoembolization (TACE) or other non-surgical treatments are recommended as the first-line therapy for these patients. However, selected patients with HCC and PVTT can undergo surgical resection (SR). The aim of this meta-analysis was to compare the outcomes of SR with Non-SR for such patients. METHODS: The PubMed, Embase, Medline and Cochrane library were searched for studies which compared SR with Non-SR for HCC and PVTT published before December 2017. RESULTS: 4810 patients from 7 studies who were enrolled in this meta-analysis were divided into the SR group (n = 2 344, 49%) and the Non-SR group (n = 2 476, 51%). The pooled hazard ratios (HRs) for the 1-, 3- and 5-year OS rates of the SR group when compared with the Non-SR group, were 0.57 (95% CI 0.48-0.67, P <0.001), 0.66 (95% CI 0.56-0.77, P <0.001) and 0.68 (95% CI 0.57-0.81, P <0.001), respectively. On subgroup analysis, the pooled HRs for the 1-, 3- and 5-year OS rates of the SR group when compared with the TACE group, were 0.62 (95% CI 0.54-0.71, P <0.001), 0.74 (95% CI 0.66-0.83, P <0.001) and 0.78 (95% CI 0.70-0.87, P <0.001), respectively. CONCLUSION: This meta-analysis showed SR resulted in better OS than TACE, or other Non-SR treatments, for patients with HCC and PVTT. SR should be considered in selected patients with resectable HCC and PVTT.

Surgical site infection after laparoscopic and open appendectomy: a multicenter large consecutive cohort study.

BACKGROUND: Laparoscopic appendectomy (LA) has been rapidly applied worldwide recently. The issue of surgical site infection (SSI) after appendectomy needs to be re-investigated and analyzed along with this trend. This study aimed to identify risk factors of SSI after appendectomy in recent years. METHODS: This retrospective study was conducted among patients with acute appendicitis who underwent either laparoscopic or open appendectomy (OA) at 7 general hospitals in China from 2010 to 2013. The incidence of SSI, classified as incisional SSI and organ/space SSI, was investigated. A multivariate logistic regression model was used to assess independent risk factors associated with overall, incisional, and organ/space SSI, respectively. RESULTS: Among 16,263 consecutive patients, 3,422 (21.0 %) and 12,841 (79.0 %) patients underwent LA and OA, respectively. The incidences of overall, incisional, and organ/space SSI were 6.2, 3.7, and 3.0 %, respectively. The proportion of LAs among both procedures increased yearly from 5.3 to 46.5 %, while the incidences of overall and incisional SSI after appendectomy simultaneously decreased yearly from 9.6 to 4.5 % and from 6.7 to 2.2 %, respectively. In comparison with OA, LA was associated with lower incidences of overall and incisional SSI (4.5 vs 6.7 %, P < 0.001; and 1.9 vs 4.2 %, P < 0.001), but a similar incidence of organ/space SSI (3.0 vs 3.0 %, P = 0.995). After multivariate logistic regression analyses were performed, LA was found to be independently associated with a decrease in development of overall SSI [odds ratio (95 % confidence interval) OR (95 % CI), 1.24 (1.03-1.70); P = 0.04] or incisional SSI [OR (95 % CI), 1.32 (1.10-1.68); P = 0.01]. CONCLUSION: With the increasing application trends of laparoscopic procedure, the incidence of SSI after appendectomy declined accordingly. Compared with OA, LA was independently associated with a significantly lower incidence of incisional SSI, but a similar incidence of organ/space SSI.

Raman spectrometer with vertical flow method for solutions containing organic solvents.

The vertical flow (VF) method improves generation and collection efficiency in Raman spectroscopy. It enhances all Raman signals, including undesired signals of organic solvents having a considerably large Raman cross section. We constructed a Raman spectrometer using the VF method to overcome this drawback and introduced a spatial line rejection mask to eliminate unnecessary bands. In addition, the design of the VF unit was improved to resist organic solvents. A VF unit with a 60-µm pinhole enhanced the signal 168 times. The spatial mask effectively eliminated the large Raman bands of the solvent and enabled a longer exposure time. The increase in the dynamic range improved the signal-to-noise ratio by 10 % in methanol and acetonitrile measurements. Raman spectrometer with the VF method and spatial mask enables us to record the Raman spectrum of solute molecules without the disturbance of solvent bands.