Minimally invasive versus open multivisceral resection for rectal cancer clinically invading adjacent organs: a propensity score-matched analysis

BACKGROUND

Minimally invasive surgery (MIS), such as laparoscopic and robotic surgery for rectal cancer, is performed worldwide. However, limited information is available on the advantages of MIS over open surgery for multivisceral resection for cases clinically invading adjacent organs.

PATIENTS AND METHODS

This was a retrospective propensity score-matching study of consecutive clinical T4b rectal cancer patients who underwent curative intent surgery between 2006 and 2021 at the University of Tokyo Hospital.

RESULTS

Sixty-nine patients who underwent multivisceral resection were analyzed. Thirty-three patients underwent MIS (the MIS group), while 36 underwent open surgery (the open group). Twenty-three patients were matched to each group. Conversion was required in 2 patients who underwent MIS (8.7%). R0 resection was achieved in 87.0% and 91.3% of patients in the MIS and open groups, respectively. The MIS group had significantly less blood loss (170 vs. 1130 mL; p < 0.0001), fewer Clavien-Dindo grade ≥ 2 postoperative complications (30.4% vs. 65.2%; p = 0.0170), and a shorter postoperative hospital stay (20 vs. 26 days; p = 0.0269) than the open group. The 3-year cancer-specific survival rate, relapse-free survival rate, and cumulative incidence of local recurrence were 75.7, 35.9, and 13.9%, respectively, in the MIS group and 84.5, 45.4, and 27.1%, respectively, in the open group, which were not significantly different (p = 0.8462, 0.4344, and 0.2976, respectively).

CONCLUSION

MIS had several short-term advantages over open surgery, such as lower complication rates, faster recovery, and a shorter hospital stay, in rectal cancer patients who underwent multivisceral resection.

hinotoriTM vs. da Vinci®: propensity score-matched analysis of surgical outcomes of robot-assisted radical prostatectomy

hinotori™ is a recently developed surgical robot system. The present study aims to compare intraoperative and postoperative outcomes of robot-assisted radical prostatectomy (RARP) by the hinotori™ system compared with those of the longer-established da Vinci® system. This study includes 100 consecutive patients who underwent RARP by da Vinci® and 60 patients who underwent RARP by hinotori™. To minimize imbalances of patient demographics between the two groups, 1:1 propensity score-matching was performed, and 43 patients each were assigned to the da Vinci® and hinotori™ groups after matching. In the propensity score-matched cohort, we could not find significant differences in patient demographics between the two groups. Surgical outcomes, operative time, and console time in the hinotori™ group were significantly longer than those in the da Vinci® group. Meanwhile, we could not find significant differences in other outcomes between the two groups, such as estimated blood loss, intraoperative complications, major postoperative complications (Clavien-Dindo grade 3 or 4) or length of hospital stay after surgery. The rate of positive cancer margin in the hinotori™ group was higher than that in the da Vinci® group, but significant difference could not be found between the two groups. Moreover, we could not find significant differences in urinary continence rates after surgery between the da Vinci® and hinotori™ groups. Our results suggest that the hinotori™ surgical robot system could provide comparable surgical outcomes to that of the da Vinci® system for patients undergoing RARP.

Prolonged preoperative sedentary time is a risk factor for postoperative ileus in patients with colorectal cancer: a propensity score-matched retrospective study

PURPOSE

This study aimed to investigate the association between prolonged preoperative sedentary time (ST) and postoperative ileus (POI) after adjusting for confounders in patients with colorectal cancer (CRC).

METHODS

This single-center retrospective study enrolled 155 consecutive patients who underwent surgery for primary CRC. A diagnosis of POI was made by the surgeons if the Clavien-Dindo classification (CD) grade is ≥ 2 within 30 days after surgery. Preoperative ST was assessed using the International Physical Activity Questionnaire usual week short version (Japanese version). Patients were classified into two groups (ST < 6 h/day and ST ≥ 6 h/day) based on results from the questionnaire, and data were analyzed using a propensity score-matching strategy to adjust for confounders. In addition, receiver operating characteristic (ROC) curve analysis was performed to identify the optimal cutoff value of preoperative ST for predicting POI.

RESULTS

Of the 155 patients, 134 were included in the analysis. POI occurred in 16 (11.9%) patients of overall patients and 11 (12.5%) of the 88 matched patients. The logistic regression analysis after propensity score-matching showed that prolonged preoperative ST (ST ≥ 6 h/day) was associated with POI (odds ratio 5.40 (95% confidence interval: 1.09 - 26.60), p = 0.038). The ROC curve analysis indicated that the optimal cutoff value of preoperative ST for predicting POI was 6 h/day.

CONCLUSION

Prolonged preoperative ST is a risk factor for POI in patients with CRC. Therefore, reducing preoperative ST may play an important role in preventing POI.

Perioperative outcomes of robot-assisted partial nephrectomy using hinotori versus da Vinci surgical robot system: a propensity score-matched analysis

The purpose of this study was to evaluate perioperative outcomes of robot-assisted partial nephrectomy (RAPN) using hinotori, a recently developed robot-assisted surgical platform, by comparing them with those using da Vinci. This study included 303 and 40 consecutive patients who underwent RAPN using da Vinci and hinotori, respectively. To adjust potential baseline parameters between da Vinci and hinotori groups, 1:2 propensity score-matching was performed, and perioperative outcomes in these two groups were comprehensively evaluated. Propensity score-matched analysis generated two groups, consisting of 74 and 37 patients undergoing RAPN using da Vinci and hinotori, respectively, and no significant differences in major baseline parameters were noted between the two groups. RAPN could be completed without conversion to nephrectomy or open surgery in all patients. There were no significant differences in major perioperative outcomes between da Vinci and hinotori groups, including the operative time, time using the robotic system and warm ischemia time. No patient in either group was diagnosed with a positive surgical margin or experienced perioperative complications, corresponding to Clavien-Dindo 3 ≤ . There were no significant differences in the achievements of trifecta and margin, ischemia and complications outcomes between the two groups, and changes in the estimated glomerular filtration rate 1 and 28 days after RAPN were also similar between them. In conclusion, these findings showed that the hinotori platform could facilitate similar perioperative outcomes in patients undergoing RAPN in comparison with the existing robotic system, da Vinci.

Doxifluridine versus Tegafur/Gimeracil/Oteracil (S-1) as adjuvant chemotherapy for patients with gastric cancer after gastrectomy: A propensity score-matched analysis

INTRODUCTION

Doxifluridine (DF), an oral 5-FU prodrug, has been used for various solid cancers due to its efficacy and low toxicity. We aim to evaluate the effect of DF as adjuvant monotherapy in advanced gastric cancer.

METHODS

We retrospectively reviewed the clinical data of 263 patients with advanced gastric cancer who underwent curative gastrectomy between January 2010 and December 2013 at our institute. Since previous randomized control trials have confirmed the efficacy of S-1 as adjuvant chemotherapy in advanced gastric cancer, we analyzed the oncologic effect and patient compliance of the DF group compared to the S-1 group. After propensity score matching, 48 patients were included in each group.

RESULTS

There was no significant difference in 5-year overall survival (OS) and 5-year disease-free survival (DFS) between DF and S-1 groups (5-year OS; 77.1% vs 75.0%; p = 0.729, 5-year DFS; 76.6% vs 73.9%; p = 0.748). The completion rates of the DF and S-1 groups were 60.4% and 72.9%, respectively (p = 0.194). The mean relative dose intensity of the DF and S-1 groups were 76.2% and 84.2%, respectively (p = 0.195). After multivariate analysis, the chemotherapy regimen was not a risk factor for OS and DFS, whereas relative dose intensity and pathologic stage were independent prognostic factors.

CONCLUSION

There was no significant difference in the oncologic effect and patient compliance between DF and S-1 groups. DF could be an alternative option for adjuvant chemotherapy in advanced gastric cancer. In addition, we confirmed that relative dose intensity is an important independent prognostic factor for survival.

Risk factors analysis and establishment of predictive nomogram of extranodal B-cell lymphoma of mucosal-associated lymphoid tissue

PURPOSE

The role of radiation therapy in mucosa-associated lymphoid tissue (MALT) lymphoma is poorly defined. The objective of this study was to explore the factors associated with the performance of radiotherapy and to assess its prognostic impact in patients with MALT lymphoma.

PATIENTS AND METHODS

Patients with MALT lymphoma diagnosed between 1992 and 2017 were identified in the US Surveillance, Epidemiology, and End Results database (SEER). Factors associated with the delivery of radiotherapy were assessed by chi-square test. Overall survival (OS) and lymphoma-specific survival (LSS) were compared between patients with and without radiotherapy, using Cox proportional hazard regression models, in patients with early stage as well as those with advanced stage.

RESULTS

Of the 10,344 patients identified with a diagnosis of MALT lymphoma, 33.6% had received radiotherapy; this rate was 38.9% for stage I/II patients and 12.0% for stage III/IV patients, respectively. Older patients and those who already received primary surgery or chemotherapy had a significantly lower rate of receiving radiotherapy, regardless of lymphoma stage. After univariate and multivariate analysis, radiotherapy was associated with improved OS and LSS in patients with stage I/II (HR=0.71 [0.65-0.78]) and (HR=0.66 [0.59-0.74]), respectively, but not in patients with stage III/IV (HR=1.01 [0.80-1.26]) and (HR=0.93 [0.67-1.29]). The nomogram built from the significant prognostic factors associated with overall survival of stage I/II patients had a good concordance (C-index=0.749±0.002).

CONCLUSION

This cohort study shows that radiotherapy is significantly associated with a better prognosis in patients with early but not advanced MALT lymphoma. Prospective studies are needed to confirm the prognostic impact of radiotherapy in patients with MALT lymphoma.

Functional, oncological outcomes and safety of laparoscopic partial nephrectomy versus open partial nephrectomy in localized renal cell carcinoma patients with high anatomical complexity

PURPOSE

Partial nephrectomy (PN) is the main treatment strategy for localized renal cell carcinoma (RCC). However, for RCC with high anatomical complexity, PN remains a challenge for urologists. Therefore, this study aimed to evaluate the functional oncological outcomes and safety of laparoscopic partial nephrectomy (LPN) versus open partial nephrectomy (OPN) in localized RCC patients with highly anatomical complexity (R.E.N.A.L. score ≥ 10).

PATIENTS AND METHODS

We retrospectively studied 575 patients who underwent PN at our center between January 2007 and December 2017. After propensity score-matching (PSM), 137 patients treated with LPN and 54 patients treated with OPN were balanced into 97 and 44 pairs. Patient demographics, and extensive perioperative and prognostic data were recorded and compared.

RESULTS

In the matched group, the OPN group had significantly less eGFR loss than the LPN group (2.57 ml/min/1.73 m² vs. 31.59 ml/min/1.73 m², P < 0.001). The recurrence-free survival (P = 0.287), overall survival (P = 0.296), cancer-specific survival (P = 0.664), and cardiocerebrovascular disease-specific survival (P = 0.341) were equivalent between groups. The rates of minor (P = 0.621) and major (P = 0.647) complications were also similar between groups.

CONCLUSIONS

This PSM cohort study showed that OPN resulted in better renal function preservation than LPN in localized RCC patients with high anatomical complexity, and had comparable oncological and safety outcomes after long-term follow-up. These findings may help improve clinical decision-making for localized RCC patients with high anatomical complexity.

Complete Cytoreductive Surgery vs. Debulking Surgery for pseudomyxoma peritonei of appendiceal origin: A propensity score-matched study based on a single-center experience

OBJECTIVE

This study aimed to report the prognostic predictors and compare the long-term outcomes of complete cytoreductive surgery (CCRS) vs. debulking surgery (DS) in patients with pseudomyxoma peritonei (PMP) of appendiceal origin.

METHODS

A retrospective analysis of 1008 consecutive patients with PMP undergoing primary surgery from January 2008 to December 2019 was performed. A propensity score-matched (PSM) analysis (1:1) was performed, and oncologic outcomes were compared between the CCRS and DS groups.

RESULTS

Out of 1008 patients, 258 patients were excluded. Baseline characteristics differed significantly between the CCRS and DS groups (total n = 750). After PSM, 106 patients were selected from each group and the baseline characteristics were matched between groups. There were significant differences between groups in operative time, the incidence of major complications (P = 0.017), and the numbers of organs removed. The median follow-up was 28 (1-131) months. Median overall survival (OS) for the 212 patients was 52.0 months (95% CI 40.2-63.8), and 10-year OS was 39.0%. Median OS could not be calculated for the CCRS group; in the DS group, this value was 41 months (P = 0.010). The 10-year OS rate was 54.2% in the CCRS group and 31.2% in the DS group. Multivariate analyses identified CCRS (P = 0.012) and histopathologic subtype (P < 0.001) as independent prognostic factors for OS.

CONCLUSIONS

In this matched-pair analysis of patients with appendiceal PMP, CCRS was safe and associated with better prognosis than DS. The completeness of cytoreduction and histopathologic subtype were two independent prognostic factors for OS.

Association of diabetes and outcomes in patients with COVID-19: Propensity score-matched analyses from a French retrospective cohort

Background

Our study aimed to compare the clinical outcomes of patients with and without diabetes admitted to hospital with COVID-19.

Methods

This retrospective multicentre cohort study comprised 24 tertiary medical centres in France, and included 2851 patients (675 with diabetes) hospitalized for COVID-19 between 26 February and 20 April 2020. A propensity score-matching (PSM) method (1:1 matching including patients’ characteristics, medical history, vital statistics and laboratory results) was used to compare patients with and without diabetes (n = 603 per group). The primary outcome was admission to an intensive care unit (ICU) and/or in-hospital death.

Results

After PSM, all baseline characteristics were well balanced between those with and without diabetes: mean age was 71.2 years; 61.8% were male; and mean BMI was 29 kg/m². A history of cardiovascular, chronic kidney and chronic obstructive pulmonary diseases were found in 32.8%, 22.1% and 6.4% of participants, respectively. The risk of experiencing the primary outcome was similar in patients with or without diabetes [hazard ratio (HR): 1.16, 95% confidence interval (CI): 0.95–1.41; P = 0.14], and was 1.29 (95% CI: 0.97–1.69) for in-hospital death, 1.26 (95% CI: 0.9–1.72) for death with no transfer to an ICU and 1.14 (95% CI: 0.88–1.47) with transfer to an ICU.

Conclusion

In this retrospective study cohort of patients hospitalized for COVID-19, diabetes was not significantly associated with a higher risk of severe outcomes after PSM.

Trial registration number

NCT04344327.

Oncological outcomes following laparoscopic surgery for pathological T4 colon cancer: a propensity score-matched analysis

PURPOSES

Whether laparoscopic colectomy (LC) is safe and effective for patients with locally advanced T4 colon cancer remains controversial. This study aimed to compare the oncological outcomes of LC and open colectomy (OC) for patients with pathological (p) T4 colon cancer.

METHODS

We retrospectively analyzed 151 consecutive patients with pT4M0 colon cancer who underwent curative surgery between 2010 and 2017 using a propensity score-matched analysis.

RESULTS

After propensity score-matching, we enrolled 100 patients (n = 50 in each group). Median follow-up was 43.5 months. The conversion rate to laparotomy in this study was 5.5% for the entire patient cohort and 6.0% for the matched cohort. Compared to the OC group, the LC group showed reductions in estimated blood loss and length of postsurgical stay. Clavien-Dindo classification grade ≥ II and all-grade complication rates were significantly lower in the LC group than in the OC group. R0 resection was achieved in all patients with LC. No significant differences were found between the groups in terms of overall, cancer-specific, recurrence-free survival, or incidence of local recurrence among the entire patient cohort and matched cohort.

CONCLUSIONS

The oncological outcomes were similar between the LC and OC groups. LC offers a safe, feasible option for patients with pT4 colon cancer.

Delayed gastric emptying after Pancreaticoduodenectomy: a propensity score-matched analysis and clinical Nomogram study

Background

Delayed gastric emptying (DGE) is a common and frustrating complication of pancreaticoduodenectomy (PD). Studies suggest that surgical methods and other clinical characteristics may affect the occurrence of DGE. Nevertheless, the results of such studies are conflicting. The objective of this work was to perform a propensity score matching analysis to compare the differences between pylorus-preserving pancreaticoduodenectomy (PPPD) and pylorus-removing pancreaticoduodenectomy (PrPD) and to develop and validate a nomogram to predict the probability of severe DGE (SDGE).

Methods

This retrospective study enrolled patients who underwent PD at our institution from December 2009 to December 2018. Propensity score matching was applied at a ratio of 1:1 to compare PPPD and PrPD groups. We compared incidence of complications, DGE, lengths of hospital stay, hospitalization costs, and mortality. Univariate and multivariate logistic regression analysis were performed to identify potential risk factors of severe DGE. Finally, a nomogram was developed and validated to predict severe DGE.

Results

The PPPD group had a significantly higher rate of postoperative pancreatic fistula (29.9% versus 17.4%, P < 0.05) and less blood loss (463.7 ml versus 694.9 ml, P < 0.05). After propensity score matching, the PPPD group had a significantly higher rate of postoperative DGE (19.2% versus 3.8%, P < 0.05), especially severe DGE (17.3% versus 0%) than the PrPD group. There were no significant differences in terms of lengths of hospital stay, hospitalization costs or mortality between the groups. Surgical method, biliary leakage, abdominal infection, and diabetes were independent risk factors for SDGE. The nomogram predicted SDGE with a training C - index of 0.798 and a validation C - index of 0.721.

Conclusion

PPPD increases the risk of DGE than PrPD, especially SDGE. Our prediction nomogram gives good prediction of SDGE after pancreaticoduodenectomy.

Perioperative neutropenia is not an independent risk factor for infectious complications of central venous line placement in children: A propensity score-matched analysis

BACKGROUND

The infectious risk of central venous line (CVL) placement in children with neutropenia (absolute neutrophil count [ANC] <500/mm³) is not well defined. This study aims to investigate the early (≤30 days) and late (>30 days) infectious complications of CVLs placed in pediatric patients with and without neutropenia.

METHODS

A retrospective review was conducted of all CVLs placed by pediatric surgeons at two institutions from 2010 to 2017. Multivariable logistic regression was performed to identify risk factors for line infection. Propensity score-matched cohorts of patients with and without neutropenia were compared in a 1:1 ratio. Wilcoxon rank-sum, Chi-square, Fisher's exact, and log-rank tests were also performed.

RESULTS

Review identified 1,102 CVLs placed in 937 patients. Fifty-four patients were neutropenic at the time of placement. Multivariable analysis demonstrated tunneled catheters and subclavian access as associated with line infection. The propensity score-matched cohort included 94 patients, 47 from each group. Demographic and preoperative data were similar between the groups (p > 0.05). Patients with neutropenia were no more likely to develop early (4.3% vs. 2.1%, p = 1.000) or late (19.1% vs. 17.0%, p = 1.000) infectious complications than patients without neutropenia, with similar median time to infection (141 vs. 222 days, p = 0.370).

CONCLUSION

A policy of selective CVL placement in neutropenic patients with standardized postoperative line maintenance is safe. Future directions include defining criteria by which neutropenic patients could be prospectively selected for safe CVL placement.

LEVEL OF EVIDENCE

II - Retrospective cohort study.

Propensity score-matching analysis for single-site robotic cholecystectomy versus single-incision laparoscopic cholecystectomy: A retrospective cohort study

BACKGROUND

Although the single-site robotic cholecystectomy(SSRC) has been performed with expectation of overcoming the limitation of single-incision laparoscopic cholecystectomy(SILC), there exists a lack of comparison studies involving SILC and SSRC. This study aimed to analyze surgical outcomes of single-site robotic cholecystectomy and single-incision laparoscopic cholecystectomy by propensity score-matching analysis.

MATERIALS AND METHODS

From March 2009 to August 2015, 290 consecutive patients underwent SSRC or SILC at Severance Hospital, Seoul, Korea. Potential confounding factors for operative outcomes were adjusted by propensity score-matching analysis. One hundred four patients from each group were evaluated for perioperative outcomes and compared for a retrospective cohort study.

RESULTS

There was no difference in potential cofounders such as gender, age, body mass index (BMI), and perioperative cholecystitis-related symptoms between two groups after propensity score-matching. However, mean operation time was shorter (56.69 ± 13.65 vs. 101.57 ± 27.05 min; p < 0.001) and median bleeding amount during surgery was less (0 (0-50) vs. 0 (0-100) mL; p < 0.001) in the SILC group. There was no significant difference between the two groups regarding conversion to conventional multiport cholecystectomy. Bile leakage due to perforation of the gallbladder during surgery was more common in the SILC group (6.7% vs. 17.3%; p = 0.019). Moreover, bile spillage rate was significantly increased in conjunction with a higher BMI in the SILC group, whereas BMI did not affect the bile leakage rate in the SSRC group.

CONCLUSIONS

SSRC is not superior to SILC except regarding bile spillage incidence. However, the technical stability and clinically undetected advantages of SSRC are expected to prompt surgeons to perform this more reliable procedure.

Prognostic impact of postoperative intra-abdominal infections after elective colorectal cancer resection on survival and local recurrence: a propensity score-matched analysis

PURPOSE

Several authors have reported an association between anastomotic leak and/or intra-abdominal abscess and oncological survival and recurrence. However, no reports have investigated whether combining anastomotic leak/intra-abdominal abscess and positive drainage culture influences long-term oncological outcomes. Therefore, we defined these complications as postoperative intra-abdominal infections. The present study aimed to evaluate the prognostic impact of postoperative intra-abdominal infections on long-term oncological outcomes after curative stage I-III colorectal cancer surgery.

METHODS

We performed a retrospective analysis of 755 consecutive patients with stage I-III colorectal cancer undergoing curative surgery between 2010 and 2015 by performing a propensity score-matched analysis to reduce selection bias.

RESULTS

Of the 755 patients, 62 were matched for postoperative intra-abdominal infections analyses. The median follow-up was 48 months. Compared with the non-infections group, the postoperative intra-abdominal infections group had a significantly shorter local recurrence-free survival (P = 0.01 prior to matching, and P = 0.05 after matching). No significant difference was found between the groups in terms of overall, cancer-specific free, recurrence-free, or distant recurrence-free survival. However, multivariate analyses identified postoperative intra-abdominal infections as an independent prognostic factor for local recurrence-free survival (P = 0.04 prior to matching, and P = 0.03 after matching).

CONCLUSIONS

In this matched-pair analysis comparing stage I-III colorectal cancer patients with and without postoperative intra-abdominal infections, postoperative intra-abdominal infections were associated with poor local recurrence-free survival, but not overall, cancer-specific free, recurrence-free, or distant recurrence-free survival.

Efficacy of Clutch Cutter for Standardizing Endoscopic Submucosal Dissection for Early Gastric Cancer: A Propensity Score-Matched Analysis

BACKGROUND/AIMS

The purpose of this study was to evaluate the safety and efficacy of gastric endoscopic submucosal dissection (ESD) using the Clutch Cutter (CC), a scissor-type knife, compared with those of procedures using conventional devices.

METHODS

This single-center retrospective study evaluated 237 patients with early gastric cancer: 83 who underwent ESD using the CC group and 154 who underwent ESD using the insulated-tip knife 2 (IT2 group). Clinicopathological features and technical outcomes were compared between the 2 groups using a propensity score-matched analysis.

RESULTS

In 61 pairs of matched patients, there was no significant difference in R0 resection, perforation, or postoperative bleeding between the CC and IT2 groups. Comparisons between the 2 groups showed similar treatment outcomes for an expert endoscopist. Nevertheless, there were significant differences between the 2 groups for nonexperts in terms of self-completion (61.7 and 24.5%, respectively, p < 0.001), mean procedure times (45 and 61 min, respectively, p = 0.002), and mean numbers of intraoperative bleeding points and bleeding points requiring hemostatic forceps (3 and 0 vs. 8 and 3, respectively, p < 0.001).

CONCLUSION

Better self-completion rates and shorter procedure times were noted for gastric ESD using the CC by nonexperts than for that using IT2, probably due to hemostatic efficacy.

Trends in obesity prevalence among total hip arthroplasty patients and the effect on surgical outcomes, 2008-2016

Introduction

The prevalence of obesity continues to rise in parallel with demand for total hip arthroplasty (THA). This study aims to report obesity trends in primary THA and its effects on procedure outcomes in the United States, stratifying based on Body Mass Index (BMI).

Methods

Primary THA procedures were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database (2008-2016). Patient demographic (including BMI), primary outcomes (death; serious morbidity), and secondary outcome variables were analyzed. Using BMI comparison groups (Obese: BMI > 30 [O]; Morbidly Obese: BMI > 40 [MO]) for case populations, univariate, propensity score-matched, and multivariate logistic regression analyses were performed.

Results

The prevalence of obesity increased among primary THA (2008: 546/1200 [45.5%], 2016: 16,078/34,137 [47.1%]) cases. Data on 135,013 primary THA cases were analyzed. Propensity score-matched analyses demonstrated that both serious morbidity (O: OR = 0.73, p < 0.001; MO: OR = 0.84, p = 0.001) and frequency of discharges home (O: OR = 0.90, p < 0.001; MO: OR = 0.71, p < 0.001) were significantly reduced. Instead, long operative times (O: OR = 1.30, p < 0.001; MO: OR = 1.53, p < 0.001), readmission (O: OR = 1.27, p < 0.001; MO: OR = 1.49, p < 0.001), and reoperation (O: OR = 1.44, p < 0.001, MO: OR = 1.96, p < 0.001) were all significantly increased in both obese and morbidly obese cases. Death (OR = 0.29; p = 0.016) was decreased in the MO cohort, while length of stay (OR = 1.19, p = 0.004) was increased in the MO cohort.

Conclusion

Both obese and morbidly obese primary THA patient populations were associated with variably increased complication risks; morbidly obese patients had higher complication rates relative to obese patients. Orthopaedic surgeons should continue to consider obesity as a risk factor for THA complications. However, given similar functional outcomes and satisfaction levels as non-obese patients, denying patients THA surgery based on BMI alone may merit reconsideration.

Effect of induction chemotherapy with cisplatin, fluorouracil, with or without taxane on locoregionally advanced nasopharyngeal carcinoma: a retrospective, propensity score-matched analysis

Background

Available data in the literature comparing different induction chemotherapy (IC) regimens on locoregionally advanced nasopharyngeal carcinoma (NPC) are scarce. The purpose of the present study was to evaluate the outcomes of locoregionally advanced NPC patients who were treated with taxane, cisplatin and 5-fluorouracil (TPF) or cisplatin and 5-fluorouracil (PF) as IC followed by concurrent chemoradiotherapy (CCRT).

Methods

In total, 1879 patients with locoregionally advanced NPC treated with IC and CCRT from a prospectively maintained database were included in the present observational study. We compared overall survival (OS), disease-specific survival (DSS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival, using the propensity score method.

Results

In total, 1256 patients received TPF or PF as IC backbone. The TPF group showed significantly better OS (hazard ratio [HR], 0.660; 95% confidence interval [CI] 0.442–0.986; P = 0.042), DSS (HR, 0.624; 95% CI 0.411–0.947; P = 0.027) and DMFS (HR, 0.589; 95% CI 0.406–0.855; P = 0.005) compared with the PF group in multivariable analyses. Propensity score matching identified 294 patients in each cohort and confirmed that TPF was associated with significantly improved 5-year OS (88.1% vs. 80.7%; P = 0.042), DSS (88.5% vs. 80.7%; P = 0.021) and DMFS (87.9% vs. 78.6%; P = 0.012) rates compared with the PF group. There were no significant differences in locoregional relapse-free survival before or after matching.

Conclusions

In our study, IC with the TPF regimen combined with CCRT showed improved long-term survival for the patients with locoregionally advanced NPC compared with the PF regimen. However, a prospective randomized clinical trial to validate these findings is necessary.

Multicenter comparative study of laparoscopic and open distal pancreatectomy using propensity score-matching

BACKGROUND

Laparoscopic distal pancreatectomy has been shown to be associated with favorable postoperative outcomes using meta-analysis. However, there have been no randomized controlled studies yet. This study aimed to compare laparoscopic and open distal pancreatectomy using propensity score-matching.

METHODS

We retrospectively collected perioperative data of 2,266 patients who underwent distal pancreatectomy in 69 institutes from 2006-2013 in Japan. Among them, 2,010 patients were enrolled in this study and divided into two groups, laparoscopic distal pancreatectomy and open distal pancreatectomy. Perioperative outcomes were compared between the groups using unmatched and propensity matched analysis.

RESULTS

After propensity score-matching, laparoscopic distal pancreatectomy was associated with favorable perioperative outcomes compared with open distal pancreatectomy, including higher rate of preservation of spleen and splenic vessels (P < 0.001); lower rates of intraoperative transfusion (P = 0.020), clinical grade of pancreatic fistula (International Study Group on Pancreatic Fistula grade B and C; P < 0.001), and morbidity (P < 0.001); and shorter hospital stay (P = 0.001), but a longer operative time (P < 0.001).

CONCLUSIONS

Laparoscopic distal pancreatectomy was associated with more favorable perioperative outcomes than open distal pancreatectomy.

An economic evaluation of public programs for internationalization: the case of the Diagnostic Program in Spain

This paper evaluates the Diagnostic Program in Spain which is a publicly funded program to promote internationalization of companies located in Andalusia (south of Spain). The methodology used is the propensity score-matching. The treatment group consists of companies which participated in the Program until 2008. The control group has companies which planned to participate in the Program but had not done so up to that date. The response variable measures the ratio of export to total sales for each company. Four covariates have been taken into account: activity, location, sales and number of employees. The analysis leads to the conclusion that the companies that participated in the Program improved their ratio of exports to total sales by about 10 percentage points.