Potential Pitfalls of Reporting and Bias in Observational Studies With Propensity Score Analysis Assessing a Surgical Procedure: A Methodological Systematic Review

Effectiveness of Spironolactone in Reducing Osteoporosis and Future Fracture Risk in Middle-Aged and Elderly Hypertensive Patients

Objective

While the role of aldosterone in bone metabolism is well established, the specific effects of the widely used aldosterone antagonist, spironolactone, on bone health are not fully understood. This study aimed to investigate the effects of spironolactone on osteoporosis and future fracture risk in middle-aged and elderly hypertensive patients, revealing its potential benefits for bone health.

Methods

Propensity score matching was employed in this study to create matched groups of spironolactone users and non-users at a 1:4 ratio. We investigated the association between spironolactone use and the risk of osteoporosis using multivariate logistic regression analysis. Furthermore, we conducted multivariate linear regression analysis to explore the relationship between cumulative dosage and the FRAX score. Subgroup analysis was also performed to assess the effects under different stratification conditions.

Results

In both pre-match and post-match analyses, multivariable logistic regression revealed a significant reduction in the risk of osteoporosis in the spironolactone usage group (pre-match: odds ratios [OR] 0.406, 95% confidence interval [CI], 0.280-0.588; post-match: OR 0.385, 95% CI, 0.259-0.571). Furthermore, post-match multivariable linear regression demonstrated a clear negative correlation between cumulative spironolactone dosage and the FRAX score. Subgroup analyses consistently supported these findings.

Conclusion

This study offers evidence supporting the significant positive impact of the antihypertensive drug spironolactone on bone health, resulting in a substantial reduction in the risk of osteoporosis and future fractures in hypertensive patients. Future research should consider conducting large-scale, multicenter, randomized controlled trials to further investigate the long-term effects of spironolactone on bone health in hypertensive patients.

The road to tailored adjuvant chemotherapy for all four non-pancreatic periampullary cancers: An international multimethod cohort study

BACKGROUND

Despite differences in tumour behaviour and characteristics between duodenal adenocarcinoma (DAC), the intestinal (AmpIT) and pancreatobiliary (AmpPB) subtype of ampullary adenocarcinoma and distal cholangiocarcinoma (dCCA), the effect of adjuvant chemotherapy (ACT) on these cancers, as well as the optimal ACT regimen, has not been comprehensively assessed. This study aims to assess the influence of tailored ACT on DAC, dCCA, AmpIT, and AmpPB.

PATIENTS AND METHODS

Patients after pancreatoduodenectomy for non-pancreatic periampullary adenocarcinoma were identified and collected from 36 tertiary centres between 2010 - 2021. Per non-pancreatic periampullary tumour type, the effect of adjuvant chemotherapy and the main relevant regimens of adjuvant chemotherapy were compared. The primary outcome was overall survival (OS).

RESULTS

The study included a total of 2866 patients with DAC (n = 330), AmpIT (n = 765), AmpPB (n = 819), and dCCA (n = 952). Among them, 1329 received ACT, and 1537 did not. ACT was associated with significant improvement in OS for AmpPB (P = 0.004) and dCCA (P < 0.001). Moreover, for patients with dCCA, capecitabine mono ACT provided the greatest OS benefit compared to gemcitabine (P = 0.004) and gemcitabine - cisplatin (P = 0.001). For patients with AmpPB, no superior ACT regime was found (P > 0.226). ACT was not associated with improved OS for DAC and AmpIT (P = 0.113 and P = 0.445, respectively).

DISCUSSION

Patients with resected AmpPB and dCCA appear to benefit from ACT. While the optimal ACT for AmpPB remains undetermined, it appears that dCCA shows the most favourable response to capecitabine monotherapy. Tailored adjuvant treatments are essential for enhancing prognosis across all four non-pancreatic periampullary adenocarcinomas.

The safety and clinical outcomes of endovascular treatment versus microsurgical clipping of ruptured anterior communicating artery aneurysms: a 2-year follow-up, multicenter, observational study

Background and objective

Current data on the optimal treatment modality for ruptured anterior communicating artery (AComA) aneurysms are limited. We conducted this multicenter retrospective study to evaluate the safety and clinical outcomes of endovascular treatment (EVT) and microsurgical clipping (MC) for the treatment of ruptured AComA patients.

Methods

Patients with ruptured AComA aneurysms were screened from the Chinese Multicenter Cerebral Aneurysm Database. Propensity score matching (PSM) was used to adjust for baseline characteristic imbalances between the EVT and MC groups. The safety outcomes included total procedural complications, procedure-related morbidity/death and remedial procedure for complication. The primary clinical outcome was 2-year functional independence measured by the modified Rankin scale (mRS) score.

Results

The analysis included 893 patients with ruptured AComA aneurysms (EVT: 549; MC: 346). PSM yielded 275 pairs of patients in the EVT and MC cohorts for comparison. Decompressive craniectomy being more prevalent in the MC group (19.3% vs. 1.5%, p < 0.001). Safety data revealed a lower rate of total procedural complications (odds ratio [OR] = 0.62, 95% CI 0.39-0.99; p = 0.044) in the EVT group and similar rates of procedure-related morbidity/death (OR = 0.91, 95% CI 0.48-1.73; p = 0.880) and remedial procedure for complication (OR = 1.35, 95% CI 0.51-3.69, p = 0.657) between the groups. Compared with that of MC patients, EVT patients had a greater likelihood of functional independence (mRS score 0-2) at discharge (OR = 1.68, 95% CI 1.14-2.50; p = 0.008) and at 2 years (OR = 1.89, 95% CI 1.20-3.00; p = 0.005), a lower incidence of 2-year all-cause mortality (OR = 0.54, 95% CI 0.31-0.93; p = 0.023) and a similar rate of retreatment (OR = 1.00, 95% CI 0.23-4.40; p = 1.000).

Conclusion

Clinical outcomes after treatment for ruptured AComA aneurysms appear to be superior to those after treatment with MC, with fewer overall procedure-related complications and no increase in the retreatment rate. Additional studies in other countries are needed to verify these findings.

Covariate Balancing Methods for Randomized Controlled Trials Are Not Adversarially Robust

The first step toward investigating the effectiveness of a treatment via a randomized trial is to split the population into control and treatment groups then compare the average response of the treatment group receiving the treatment to the control group receiving the placebo. To ensure that the difference between the two groups is caused only by the treatment, it is crucial that the control and the treatment groups have similar statistics. Indeed, the validity and reliability of a trial are determined by the similarity of two groups' statistics. Covariate balancing methods increase the similarity between the distributions of the two groups' covariates. However, often in practice, there are not enough samples to accurately estimate the groups' covariate distributions. In this article, we empirically show that covariate balancing with the standardized means difference (SMD) covariate balancing measure, as well as Pocock and Simon's sequential treatment assignment method, are susceptible to worst case treatment assignments. Worst case treatment assignments are those admitted by the covariate balance measure, but result in highest possible ATE estimation errors. We developed an adversarial attack to find adversarial treatment assignment for any given trial. Then, we provide an index to measure how close the given trial is to the worst case. To this end, we provide an optimization-based algorithm, namely adversarial treatment assignment in treatment effect trials (ATASTREET), to find the adversarial treatment assignments.

Mini- or less-open sublay (E/MILOS) operation vs open sublay and laparoscopic IPOM repair for the treatment of incisional hernias: a registry-based propensity score matched analysis of the 5-year results

BACKGROUND

Open sublay and laparoscopic IPOM repair have specific disadvantages and risks. In recent years, this evidence led to a paradigm shift and induced the development of new minimally invasive techniques of sublay mesh repair.

METHODS

Pioneering this trend, we developed the endoscopically assisted mini- or less-open sublay (MILOS) concept. The operation is performed trans-hernially via a small incision with light-holding laparoscopic instruments either under direct, or endoscopic visualization. After dissection of an extra-peritoneal space of at least 8 cm, port placement and CO2 insufflation, each MILOS operation can be continued endoscopically (EMILOS repair). All E/MILOS operations were prospectively documented in the Herniamed Registry with 1- and 5-year questionnaire follow-ups. Propensity score matching of incisional hernia operations comparing the results of the E/MILOS operation with the laparoscopic intraperitoneal onlay mesh operation (IPOM) and open sublay repair from all other institutions participating in the Herniamed Registry was performed. The results with perioperative complications and 1-year follow-up have been published previously.

RESULTS

This paper reports on the 5-year results. The 5-year follow-up rate was 87.5% (538 of 615 patients with E/MILOS incisional hernia operations). Comparing E/MILOS repair with laparoscopic IPOM and open sublay operation, propensity score matching analysis was possible with 448 and 520 pairs of operations, respectively. Compared with laparoscopic IPOM incisional hernia operation, the E/MILOS repair is associated with significantly fewer general complications (P = 0.004), recurrences (P < 0.001), less pain on exertion (P < 0.001), and less chronic pain requiring treatment (P = 0.016) and tends to result in fewer postoperative complications (P = 0.052), and less pain at rest (P = 0.053). Matched pair analysis with open sublay repair revealed significantly fewer general complications (P < 0.001), postoperative complications (P < 0.001), recurrences (P = 0.002), less pain at rest (P = 0.004), less pain on exertion (P < 0.001), and less chronic pain requiring treatment (P = 0.014). A limitation of this analysis is a relative low 5-year follow-up rate for laparoscopic IPOM and open sublay.

CONCLUSIONS

The E/MILOS technique allows minimally invasive trans-hernial repair of incisional hernias using large standard meshes with low morbidity and good long-term results. The technique combines the advantages of sub-lay repair and a mini- or less-invasive approach.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT03133000.

Single-incision versus conventional multiport laparoscopic cholecystectomy in acute cholecystitis according to disease severity: single center retrospective study in Korea

Purpose

The safety of single-incision laparoscopic cholecystectomy (SILC) for acute cholecystitis (AC) has not yet been confirmed.

Methods

This single-center retrospective study included patients who underwent laparoscopic cholecystectomy (LC) for AC between April 2010 and December 2020. Propensity scores were used to match patients who underwent SILC with those who underwent conventional multiport LC (CMLC) in the entire cohort and in the two subgroups.

Results

A total of 1,876 patients underwent LC for AC, and 427 (22.8%) underwent SILC. In the propensity score-matched analysis of the entire cohort (404 patients in each group), the length of hospital stay (2.9 days vs. 3.5 days, p = 0.029) was shorter in the SILC group than in the CMLC group. No significant differences were observed in other surgical outcomes. In grade I AC (336 patients in each group), the SILC group showed poorer surgical outcomes than the CMLC group, regarding operation time (57.6 minutes vs. 52.4 minutes, p = 0.001) and estimated blood loss (22.9 mL vs. 13.1 mL, p = 0.006). In grade II/III AC (58 patients in each group), there were no significant differences in surgical outcomes between the two groups. Postoperative pain outcomes were also not significantly different in the two groups, regardless of severity.

Conclusion

This study demonstrated that SILC had similar surgical and pain outcomes to CMLC in patients with AC; however, subgroup analysis showed that SILC was associated with poor surgical outcomes than CMLC in grade I AC. Therefore, SILC should be carefully performed in patients with AC by experienced hepatobiliary surgeons.

No role for protease inhibitors as a mitigation strategy for postpancreatectomy acute pancreatitis (PPAP): Propensity score matching analysis

BACKGROUND

While the use of protease inhibitor gabexate mesylate (GM) is still controversial in acute pancreatitis, it has never been tested for postpancreatectomy acute pancreatitis (PPAP). This study aims to assess the impact of GM on postoperative serum hyperamylasaemia (POH) or PPAP after pancreatoduodenectomy (PD).

METHODS

Consecutive patients developing POH after PD between 2016 and 2021 were included. According to GM administration, patients were divided into GM-treated and control (CTR) groups. GM was administered from postoperative day 1-3 in POH patients who underwent surgery before 2017. A 2:1 propensity matching was used to minimize the risk of bias.

RESULTS

Overall, 264 patients with POH were stratified in the GM (59 patients) and CTR (104 patients) cohorts, which showed balanced baseline characteristics after matching. No difference in postoperative complications was observed between the groups (all p > 0.05), except for PPAP occurrence, which was significantly higher in the GM group (37% vs. 22%, p = 0.037). A total of 45 patients (28%) evolved to PPAP. Comparing PPAP patients in the GM and CTR groups, no significant differences in POPF, relaparotomy, and mortality (all p > 0.09) were found. No difference in intravenous crystalloid administration was found in patients with PPAP, whether or not they developed major complications or pancreatic fistula (p > 0.05) CONCLUSION: Protease inhibitor seems ineffective in preventing a PPAP after PD once a POH has occurred. Further studies are needed to achieve benchmarks for treating PPAP and identify mitigation strategies to prevent the evolution of POH into additional morbidity.

Association of magnesium sulfate use with mortality in critically ill patients with sepsis: a retrospective propensity score-matched cohort study

BACKGROUND

Trials have demonstrated lower rates of acute kidney injury in critically ill patients receiving magnesium supplementation, but they have yielded conflicting results regarding mortality.

METHODS

This is a retrospective cohort study based on the MIMIC-IV (Medical Information Mart in Intensive Care-IV) database. Adult critically ill patients with sepsis were included in the analysis. The exposure was magnesium sulfate use during ICU stay. The primary outcome was 28-day all-cause mortality. Propensity score matching (PSM) was conducted at a 1:1 ratio. Multivariable analyses were used to adjust for confounders.

RESULTS

The pre-matched and propensity score-matched cohorts included 10 999 and 6052 patients, respectively. In the PSM analysis, 28-day all-cause mortality rate was 20.2% (611/3026) in the magnesium sulfate use group and 25.0% (757/3026) in the no use group. Magnesium sulfate use was associated with lower 28-day all-cause mortality (hazard ratio [HR], 0.70; 95% CI, 0.61-0.79; P<0.001). Lower mortality was observed regardless of baseline serum magnesium status: for hypomagnesaemia, HR, 0.64; 95% confidence interval (CI), 0.45-0.93; P=0.020; for normomagnesaemia, HR, 0.70; 95% CI, 0.61-0.80; P<0.001. Magnesium sulfate use was also associated with lower ICU mortality (odds ratio [OR], 0.52; 95% CI, 0.42-0.64; P<0.001), lower in-hospital mortality (OR, 0.65; 95% CI, 0.55-0.77; P<0.001), and renal replacement therapy (OR, 0.67; 95% CI, 0.52-0.87; P=0.002). A sensitivity analysis using the entire cohort also demonstrated lower 28-day all-cause mortality (HR, 0.62; 95% CI, 0.56-0.69; P<0.001).

CONCLUSIONS

Magnesium sulfate use was associated with lower mortality in critically ill patients with sepsis. Prospective studies are needed to verify this finding.

Association between periodontitis and postoperative complications in hospital medical surgical procedures: a systematic review

Background

Periodontitis is potentially harmful in the perioperative period due to biofilm generating a environment for bacteria to spread and colonize other anatomical areas, which can generate a potential risk of infection, delayed healing, increased morbidity, and even induce avulsion in intubated patients, and subsequent aspiration or ingestion of teeth with increased mobility.

Objective

Associate the presence of periodontitis and postoperative complications in patients who underwent an in-hospital medical surgical procedure.

Methods

A systematic review based on studies extracted from PubMed and Scopus was carried out on June 10, 2020, based on the Population, Intervention, Comparison and Result search strategy. As inclusion criteria, the studies had to include all the disaggregated terms of the research question, have a publication date of less than 15 years, and the target population had to have undergone elective hospital medical-surgical interventions. The exclusion criteria corresponded to not presenting an analytical or experimental observational study design, not having made a periodontal clinical diagnosis of the study subjects, and not expressing in the results the presence of postoperative medical-hospital complications. Articles were assessed for quality by supplementing the STROBE guideline and Newcastle Ottawa, for risk of bias by supplementing the STROBE guideline and the Cochrane Collaboration handbook tool.

Results

A total of 131 articles were obtained, which were subjected to a selection process, resulting in 5 final analytical observational studies. A meta-analysis was performed and determined that periodontitis was a risk factor to postoperative complications after surgical procedures with an OR = 4,76; 95%CI [1,11-20,41].

Conclusions

Optimize the guidelines for assessing quality and risk of bias can make their comparison with other studies complex, however it was determined in a statistically significant way that patients with periodontitis have a higher risk of generating postoperative complications after a medical hospital surgery.

Long-term Outcomes After Laparoscopic, Robotic, and Open Pancreatoduodenectomy for Distal Cholangiocarcinoma: An International Propensity Score-matched Cohort Study

OBJECTIVE

This study aimed to compare surgical and oncological outcomes after minimally invasive pancreatoduodenectomy (MIPD) versus open pancreatoduodenectomy (OPD) for distal cholangiocarcinoma (dCCA).

BACKGROUND

A dCCA might be a good indication for MIPD, as it is often diagnosed as primary resectable disease. However, multicenter series on MIPD for dCCA are lacking.

METHODS

This is an international multicenter propensity score-matched cohort study including patients after MIPD or OPD for dCCA in 8 centers from 5 countries (2010-2021). Primary outcomes included overall survival (OS) and disease-free interval (DFI). Secondary outcomes included perioperative and postoperative complications and predictors for OS or DFI. Subgroup analyses included robotic pancreatoduodenectomy (RPD) and laparoscopic pancreatoduodenectomy (LPD).

RESULTS

Overall, 478 patients after pancreatoduodenectomy for dCCA were included of which 97 after MIPD (37 RPD, 60 LPD) and 381 after OPD. MIPD was associated with less blood loss (300 vs 420 mL, P =0.025), longer operation time (453 vs 340 min; P <0.001), and less surgical site infections (7.8% vs 19.3%; P =0.042) compared with OPD. The median OS (30 vs 25 mo) and DFI (29 vs 18) for MIPD did not differ significantly between MIPD and OPD. Tumor stage (Hazard ratio: 2.939, P <0.001) and administration of adjuvant chemotherapy (Hazard ratio: 0.640, P =0.033) were individual predictors for OS. RPD was associated with a higher lymph node yield (18.0 vs 13.5; P =0.008) and less major morbidity (Clavien-Dindo 3b-5; 8.1% vs 32.1%; P =0.005) compared with LPD.

DISCUSSION

Both surgical and oncological outcomes of MIPD for dCCA are acceptable as compared with OPD. Surgical outcomes seem to favor RPD as compared with LPD but more data are needed. Randomized controlled trials should be performed to confirm these findings.

Impact of titanium-coated polypropylene mesh on functional outcome and quality of life after inguinal hernia repair

Objective

This study aims to compare the clinical outcomes of complications, quality of life, and chronic pain between titanium-coated polypropylene mesh and polypropylene mesh after Lichtenstein or TAPP surgery.

Methods

A retrospective cohort study was conducted, involving patients who underwent inguinal hernia repair using Timesh light®, Optilene LP®, or 3DMax™ meshes between January 2020 and May 2022. Based on the surgical method, patients were divided into Lichtenstein and TAPP groups, and further categorized according to the type of mesh used. The primary endpoints assessed postoperative complications, postoperative pain, and postoperative quality of life. Secondary endpoints included postoperative sensation in the surgical area and postoperative recurrence rate.

Results

A total of 180 Lichtenstein procedures and 478 TAPP procedures were included in the analysis after propensity score matching. The findings revealed that patients with titanium-coated polypropylene mesh did not exhibit significant advantages in perioperative data. Within three months to one year after TAPP surgery, patients with the titanium-coated polypropylene mesh reported improved foreign body sensation during activities (P = 0.002) and a lower incidence of chronic pain (P = 0.008). However, after one year, these advantages of titanium-coated polypropylene mesh were no longer significant during activity or at rest. In the TAPP group, the titanium-coated polypropylene mesh depicted advantages in the single score of the SF-36 questionnaire.

Conclusions

The utilization of titanium-coated polypropylene mesh resulted in reduced foreign body sensation and chronic pain in activity within one year after TAPP surgery, significantly enhancing certain aspects of the patient's quality of life compared to polypropylene mesh.

Single Center, Propensity Score Matching Analysis of Different Reconstruction Techniques following Pancreatoduodenectomy

BACKGROUND

Pancreatoduodenectomy is still hampered by significant morbidity. So far, there is no universally accepted technique aimed at minimizing postoperative complications. Herein, we compare three different reconstruction techniques.

METHODS

This is a retrospective study of a prospectively maintained database including 283 patients operated between January 2010 and December 2020. Three reconstruction techniques were compared: (1) the Neuhaus-style telescope pancreatojejunostomy, (2) the pancreatogastrostomy, and (3) the modified Blumgart-style, duct-to-mucosa pancreatojejunostomy. The primary endpoint consisted in determining the rates of clinically relevant postoperative pancreatic fistulas (CR-POPF); the secondary endpoints included 90 days morbidity and mortality rates. A propensity score matching analysis was used.

RESULTS

Rates of CR-POPF did not differ significantly between the groups (Neuhaus-style pancreatojejunostomy 16%, pancreatogastrostomy 17%, modified Blumgart-style pancreatojejunostomy 15%), neither in the unmatched nor in the matched analysis (p = 0.993 and p = 0.901, respectively). Similarly, no significant differences could be observed with regard to major morbidity (unmatched p = 0.596, matched p = 0.188) and mortality rates (unmatched p = 0.371, matched p = 0.209) within the first 90 days following surgery. Propensity-score matching analyses revealed, however, a higher occurrence of post-pancreatectomy hemorrhage after pancreatogastrostomy (p = 0.015).

CONCLUSION

Similar CR-POPF rates suggest no crucial role of the applied reconstruction technique. Increased incidence of intraluminal post-pancreatectomy hemorrhages following pancreatogastrostomy demands awareness for meticulous hemostasis.

Application of big data in ophthalmology

The advents of information technologies have led to the creation of ever-larger datasets. Also known as big data, these large datasets are characterized by its volume, variety, velocity, veracity, and value. More importantly, big data has the potential to expand traditional research capabilities, inform clinical practice based on real-world data, and improve the health system and service delivery. This review first identified the different sources of big data in ophthalmology, including electronic medical records, data registries, research consortia, administrative databases, and biobanks. Then, we provided an in-depth look at how big data analytics have been applied in ophthalmology for disease surveillance, and evaluation on disease associations, detection, management, and prognostication. Finally, we discussed the challenges involved in big data analytics, such as data suitability and quality, data security, and analytical methodologies.

Is it feasible and ethical to randomize patients between surgery and non-surgical treatments for gastrointestinal cancers?

Background

In several settings in the treatment of gastrointestinal cancers, it is unclear if the addition of surgery to a multimodal treatment strategy, or in some circumstances its omission, lead to a better outcome for patients. In such situations of clinical equipoise, high-quality evidence from randomised-controlled trials is needed to decide which treatment approach is preferable.

Objective

In this article, we outline the importance of randomised trials comparing surgery with non-surgical therapies for specific scenarios in the treatment of gastrointestinal cancers. We explain the difficulties and solutions of designing these trials and recruiting patients in this context.

Methods

We performed a selective review based on a not systematic literature search in core databases, supplemented by browsing health information journals and citation searching. Only articles in English were selected. Based on this search, we discuss the results and methodological characteristics of several trials which randomised patients with gastrointestinal cancers between surgery and non-surgical treatments, highlighting their differences, advantages, and limitations.

Results and conclusions

Innovative and effective cancer treatment requires randomised trials, also comparing surgery and non-surgical treatments for defined scenarios in the treatment of gastrointestinal malignancies. Nevertheless, potential obstacles to designing and carrying out these trials must be recognised ahead of time to avoid problems before or during the trial.

Comparison of Minimally Invasive Surgery with Open Surgery for Remnant Gastric Cancer: A Multi-institutional Cohort Study

BACKGROUND

Despite growing evidence of the effectiveness of minimally invasive surgery (MIS) for primary gastric cancer, MIS for remnant gastric cancer (RGC) remains controversial due to the rarity of the disease. This study aimed to evaluate the surgical and oncological outcomes of MIS for radical resection of RGC.

PATIENTS AND METHODS

Patients with RGC who underwent surgery between 2005 and 2020 at 17 institutions were included, and a propensity score matching analysis was performed to compare the short- and long-term outcomes of MIS with open surgery.

RESULTS

A total of 327 patients were included in this study and 186 patients were analyzed after matching. The risk ratios for overall and severe complications were 0.76 [95% confidence interval (CI): 0.45, 1.27] and 0.65 (95% CI: 0.32, 1.29), respectively. The MIS group had significantly less blood loss [mean difference (MD), -409 mL; 95% CI: -538, -281] and a shorter hospital stay (MD, -6.5 days; 95% CI: -13.1, 0.1) than the open surgery group. The median follow-up duration of this cohort was 4.6 years, and the 3-year overall survival were 77.9% and 76.2% in the MIS and open surgery groups, respectively [hazard ratio (HR), 0.78; 95% CI: 0.45, 1.36]. The 3-year relapse-free survival were 71.9% and 62.2% in the MIS and open surgery groups, respectively (HR, 0.71; 95% CI: 0.44, 1.16).

CONCLUSIONS

MIS for RGC showed favorable short- and long-term outcomes compared to open surgery. MIS is a promising option for radical surgery for RGC.

Outcomes After Minimally Invasive Versus Open Total Pancreatectomy: A Pan-European Propensity Score Matched Study

OBJECTIVE

To assess postoperative 90-day outcomes after minimally invasive (laparoscopic/robot-assisted) total pancreatectomy (MITP) in selected patients versus open total pancreatectomy (OTP) among European centers.

BACKGROUND

Minimally invasive pancreatic surgery is becoming increasingly popular but data on MITP are scarce and multicenter studies comparing outcomes versus OTP are lacking. It therefore remains unclear if MITP is a valid alternative.

METHODS

Multicenter retrospective propensity-score matched study including consecutive adult patients undergoing MITP or OTP for all indications at 16 European centers in 7 countries (2008-2017). Patients after MITP were matched (1:1, caliper 0.02) to OTP controls. Missing data were imputed. The primary outcome was 90-day major morbidity (Clavien-Dindo ≥3a). Secondary outcomes included 90-day mortality, length of hospital stay, and survival.

RESULTS

Of 361 patients (99MITP/262 OTP), 70 MITP procedures (50 laparoscopic, 15 robotic, 5 hybrid) could be matched to 70 OTP controls. After matching, MITP was associated with a lower rate of major morbidity (17% MITP vs. 31% OTP, P = 0.022). The 90-day mortality (1.4% MITP vs. 7.1% OTP, P = 0.209) and median hospital stay (17 [IQR 11-24] MITP vs. 12 [10-23] days OTP, P = 0.876) did not differ significantly. Among 81 patients with PDAC, overall survival was 3.7 (IQR 1.7-N/A) versus 0.9 (IQR 0.5-N/ A) years, for MITP versus OTP, which was nonsignificant after stratification by T-stage.

CONCLUSION

This international propensity score matched study showed that MITP may be a valuable alternative to OTP in selected patients, given the associated lower rate of major morbidity.

Is No. 12a Lymph Node Dissection Compliance Necessary in Patients Who Undergo D2 Gastrectomy for Gastric Adenocarcinomas? A Population-Based Retrospective Propensity Score Matching Study

LN dissection is essential for accurately staging and improving GC patient prognosis. However, the compliance rate for No. 12a LND in practice is low, and its necessity is controversial. Data from GC patients who underwent total gastrectomy (TG)/distal gastrectomy (DG) plus D2 lymphadenectomy between January 2000 and December 2017 at West China Hospital, Sichuan University were reviewed. No. 12a LND noncompliance's effect on the long-term prognosis of patients with GC after D2 gastrectomy was explored. Of the 2788 patients included, No. 12a LND noncompliance occurred in 1753 patients (62.9%). Among 1035 patients with assessable LNs from station 12a, 98 (9.5%) had positive LNs detected at station 12a. No. 12a LN metastasis patients (stage IV not included) had significantly better overall survival (OS) than TNM stage IV patients (p = 0.006). Patients with No. 12a LND compliance had a significantly higher OS than those without, both before (p < 0.001) and after (p < 0.001) PSM. Cox multivariate analysis confirmed that No. 12a LND noncompliance was an independent prognostic factor before (HR 1.323, 95% CI 1.171-1.496, p < 0.001) and after (HR 1.353, 95% CI 1.173-1.560, p < 0.001) PSM. In conclusion, noncompliance with No. 12a LND compromised the long-term survival of patients who underwent D2 gastrectomy for GC.

Serum Ferritin Has Limited Prognostic Value on Mortality Risk in Patients with Decompensated Cirrhosis: A Propensity Score Matching Analysis

OBJECTIVE

The prognostic value of serum ferritin remains elusive in the literature. We aimed to examine the association between serum ferritin and mortality risk in cirrhosis.

METHODS

A total of 257 cirrhotic patients were recruited. The cut-off of serum ferritin was determined by X-tile. The Cox regression and Kaplan-Meier method were used. A 1:1 propensity score matching (PSM) was performed to diminish the impacts of selection bias and possible confounders.

RESULTS

The difference regarding mortality was mostly significant for serum ferritin >158 ng/mL. Before PSM, serum ferritin >158 ng/mL was an independent predictor of mortality. However, the clinical relevance of high ferritin level for prognostication was blunted after PSM (survival rate: 86.8% vs 96.3%, P = .078). Cox regression indicated that model for end-stage liver disease remains only independent risk factor of 180-day mortality after PSM.

CONCLUSION

Serum ferritin may not serve as an independent prognostic indicator of mortality risk in decompensated cirrhotic patients.

Effect of 2D vs. 3D laparoscopy on postoperative complications and operation time in a propensity-score-matched real-world data analysis

BACKGROUND

Postoperative complication rates using 3D visualization are rarely reported. The primary aim of our study is to detect a possible advantage of using 3D on postoperative complication rates in a real-world setting.

METHOD

With a sample size calculation for a medium effect size difference that 3D reduces significantly postoperative complications, data of 287 patients with 3D visualization and 832 with 2D procedure were screened. The groups underwent an exact propensity score-matching to be comparable. Comprehensive complication index (CCI) for every procedure was calculated and Operation Time was determined.

RESULTS

Including 1078 patients in the study, 213 exact propensity score-matched pairs could finally be established. Concerning overall CCI (3D: 5.70 ± 13.63 vs. 2D: 3.37 ± 9.89; p = 0.076) and operation time (3D: 103.98 ± 93.26 min vs. 2D: 88.60 ±6 9.32 min; p = 0.2569) there was no significant difference between the groups.

CONCLUSION

Our study shows no advantage of 3D over 2D laparoscopy regarding postoperative complications in a real-world setting, the second endpoint operation time, too, was not influenced by 3D overall.

Myeloperoxidase Levels in Pericardial Fluid Is Independently Associated with Postoperative Atrial Fibrillation after Isolated Coronary Artery Bypass Surgery

BACKGROUND

Postoperative atrial fibrillation (POAF) is the most common complication after surgery for atherosclerotic cardiovascular disease (ASCVD) and leads to extended hospital stays and increased mortality. Myeloperoxidase (MPO) in postoperative pericardial drainage fluid is associated with an increased risk of POAF; however, the correlations between MPO in intraoperative pericardial fluid and POAF remain largely unknown. The aim of the study was to evaluate whether MPO is associated with POAF.

METHODS

A total of 97 patients with no history of atrial arrhythmia who had undergone coronary artery bypass surgery (CABG) were identified. We prospectively measured the levels of MPO in intraoperative pericardial fluid and blood using the human magnetic Luminex assay. Then, the occurrence of atrial fibrillation was continuously observed by postoperative ECG and telemetry strips until discharge.

RESULTS

Our data showed that POAF occurred in 24 of 97 patients (24.74%). MPO levels in blood were higher in the POAF group than the SR group (p = 0.064). Patients with POAF had significantly higher intraoperative pericardial fluid MPO levels than patients who remained in SR (p = 0.021). There was no significant correlation between pericardial fluid MPO levels and blood MPO levels (r = -0.47, p = 0.770). In a multivariable logistic regression model, pericardial fluid MPO levels were significantly associated with a higher risk of POAF (odds ratio = 1.016, 95% confidence interval, 1.001-1.031; p = 0.031).

CONCLUSIONS

Higher intraoperative pericardial fluid MPO levels are linked with POAF in patients undergoing CABG. This finding provides insight into a possible mechanism of MPO in pericardial fluid increase susceptibility to developing POAF in patients undergoing CABG.

A Systematic Review of Propensity Score Matching in the Orthopedic Literature

Background

Propensity score matching (PSM) is a statistical technique used to reduce bias in observational studies by controlling for measured confounders. Given its complexity and popularity, it is imperative that researchers comprehensively report their methodologies to ensure accurate interpretation and reproducibility.

Purpose

This systematic review sought to define how often PSM has been used in recent orthopedic research and to describe how such studies reported their methods. Secondary aims included analyzing study reproducibility, bibliometric factors associated with reproducibility, and associations between methodology and the reporting of statistically significant results.

Methods

PubMed and Embase databases were queried for studies containing "propensity score" and "match*" published in 20 orthopedic journals prior to 2020. All studies meeting inclusion criteria were used for trend analysis. Articles published between 2017 and 2019 were used for analysis of reporting quality and reproducibility.

Results

In all, 261 studies were included for trend analysis, and 162 studies underwent full-text review. The proportion of orthopedic studies using PSM significantly increased over time. Seventy-one (41%) articles did not provide justification for covariate selection. The majority of studies illustrated covariate balance through P values. We found that 19% of the studies were fully reproducible. Most studies failed to report the use of replacement (67.3%) or independent or paired statistical methods (34.0%). Studies reporting standardized mean differences to illustrate covariate balance were less likely to report statistically significant results.

Conclusion

Despite the increased use of PSM in orthopedic research, observational studies employing PSM have largely failed to adequately report their methodology.

A protective factor against lymph node metastasis of papillary thyroid cancer: Female gender

OBJECTIVE

Papillary thyroid carcinoma (PTC) is the most common pathological type of thyroid cancer, with good prognosis, but the rate of lymph node metastasis (LNM) is high, and the difference between men and women is significant. Therefore, the related risk factors for LNM of PTC based on gender were examined in this study in order to draw attention to gender factor in PTC.

METHODS

We retrospectively analyzed the clinicopathological data of 2103 patients with surgically confirmed PTC at the Fourth affiliated Hospital of Hebei Medical University West Side between January 2016 and December 2019.

RESULTS

LNM was detected in 1124 of the 2103 cases of PTC. Logistic regression analysis showed that LNM was associated with age (p < 0.001, OR:0.547), gender (p < 0.001, OR:2.609), tumor diameter (p < 0.001, OR:2.995), bilaterality (p=0.003, OR:1.683), and extrathyroid extension (p < 0.001, OR:1.657). After propensity score matching, female gender (p < 0.001, OR: 0.393) remained an independent factor of LNM in patients with PTC. LNM in men was only associated with diameter (p < 0.001, OR: 3.246). LNM in woman was associated with menopausal history (p = 0.012, OR=0.684), reproductive history (p < 0.001, OR=0.360), abortion history (p = 0.011, OR=0.725), tumor diameter >1 cm (p < 0.001, OR=2.807), bilaterality (p =0.006, OR:1.728), and extrathyroid extension (p < 0.001, OR=1.879).

CONCLUSION

Although the invasion is high in female patients, the rate of LNM is significantly reduced due to the influence of sex hormones and reproductive factors. For female patients of childbearing age who were not pregnant and did not have children, it is suggested to take a positive attitude towards their lymph nodes.

Which one is better? Laparoscopic versus robotic reconstruction in the remnant soft pancreas with a small pancreatic duct following pancreaticoduodenectomy: a multicenter study with propensity score matching analysis

BACKGROUND

Evidence of the advantages of robotic pancreaticoduodenectomy (RPD) over laparoscopic pancreaticoduodenectomy (LPD) is limited. Thus, this study aimed to compare the surgical outcomes of laparoscopic reconstruction L-recon) versus robotic reconstruction (R-recon) in patients with soft pancreas and small pancreatic duct.

METHOD

Among 429 patients treated with minimally invasive pancreaticoduodenectomy (MIPD) between October 2012 and June 2020 by three surgeons at three institutions, 201 patients with a soft pancreas and a small pancreatic duct (< 3 mm) were included in this study.

RESULTS

Sixty pairs of patients who underwent L-recon and R-recon were selected after propensity score matching. The perioperative outcomes were comparable between the reconstruction approaches, with comparable clinically relevant postoperative pancreatic fistula (CR-POPF) rates (15.0% [L-recon] vs. 13.3% [R-recon]). The sub-analysis according to the type of MIPD procedure also showed comparable outcomes, but only a significant difference in postoperative hospital stay was identified. During the learning curve analysis using the cumulative summation by operation time (CUSUM_OT), two surgeons who performed both L-recon and R-recon procedures reached their first peak in the CUSUM_OT graph earlier for the R-recon group than for the L-recon group (i.e., 20th L-recon case and third R-recon case of surgeon A and 43rd L-recon case and seventh R-recon case of surgeon B). Surgeon C, who only performed R-recon, demonstrated the first peak in the 22nd case. The multivariate regression analysis for risk factors of CR-POPF showed that the MIPD procedure type, as well as other factors, did not have any significant effect.

CONCLUSION

Postoperative pancreatic fistula rates and the overall perioperative outcomes of L-recon and R-recon were comparable in patients with soft-textured pancreas and small pancreatic duct treated by experienced surgeons.

The impact and role of hepatic hydrothorax in the prognosis of patients with decompensated cirrhosis: A retrospective propensity score-matched study

Background and aims

Hepatic Hydrothorax (HH) is one of the complications in patients with decompensated cirrhosis and its impact and role in the prognosis of patients with decompensated cirrhosis are not yet clear. Thus, this study aimed to determine the role of HH in patients with decompensated cirrhosis and the long-term impact on their mortality.

Materials and methods

A retrospective study analyzed 624 patients with ascites without pleural effusion in decompensated cirrhosis and 113 patients with HH. Propensity scores were calculated based on eight variables, and the HH and non-HH groups were matched in a 1:1 ratio. The effect and role of HH on the prognosis of patients with decompensated cirrhosis was analyzed using the Kaplan–Meier method and Cox proportional hazards regression model.

Results

A total of 737 patients were included. Out of 113 HH patients, 106 could be matched to 106 non-HH patients. After matching, baseline characteristics were well-balanced. The multifactorial Cox proportional hazards model indicated that hepatic encephalopathy and HH were independent risk factors affecting prognostic survival in patients with decompensated cirrhosis (P < 0.01), with risk ratios and 95% confidence intervals (CI) of 2.073 (95% CI: 1.229–3.494, P < 0.01) and 4.724 (95% CI: 3.287–6.789, P < 0.01), respectively. Prognostic survival was significantly worse in the HH group compared to patients in the non-HH group, with mortality rates of 17.9, 30.1, and 59.4% at 6 months, 1 year, and 2 years in the HH group, compared to 0.9, 3.8, and 5.6% in the non-HH group, respectively. The estimated median survival time was 21 (95% CI: 18–25) months in the HH group and 49 (95% CI: 46–52) months in the non-HH group (P < 0.001).

Conclusion

Hepatic hydrothorax is significantly associated with higher mortality in patients with decompensated cirrhosis and is a highly negligible independent decompensated event affecting their prognosis.

Radiofrequency-assisted transection of the pancreas vs stapler in distal pancreatectomy: a propensity score matched cohort analysis

To demonstrate the efficacy of radiofrequency for pancreatic stump closure in reducing the incidence of postoperative pancreatic fistula (POPF) in distal pancreatectomy (DP) compared with mechanical transection methods. Despite all the different techniques of pancreatic stump closure proposed for DP, best practice for avoiding POPF remains an unresolved issue, with an incidence of up to 30% regardless of center volume or surgical expertise. DP was performed in a cohort of patients by applying radiofrequency to stump closure (RF Group) and compared with mechanical closure (Control Group). A propensity score (PS) matched cohort study was carried out to minimize bias from nonrandomized treatment assignment. Cohorts were matched by PS accounting for factors significantly associated with either undergoing RF transection or mechanical closure through logistic regression analysis. The primary end-point was the incidence of clinically relevant POPF (CR-POPF). Of 89 patients included in the whole cohort, 13 case patients from the RF-Group were 1:1 matched to 13 control patients. In both the first independent analysis of unmatched data and subsequent adjustment to the overall propensity score-matched cohort, a higher rate of CR-POPF in the Control Group compared with the RF-Group was detected (25.4% vs 5.3%, p = 0.049 and 53.8% vs 0%; p = 0.016 respectively). The RF Group showed better outcomes in terms of readmission rate (46.2% vs 0%, p = 0.031). No significant differences were observed in terms of mortality, major complications (30.8% vs 0%, p = 0.063) or length of hospital stay (5.7 vs 5.2 days, p = 0.89). Findings suggest that the RF-assisted technique is more efficacious in reducing CR-POPF than mechanical pancreatic stump closure.

Association of Adjuvant Chemotherapy With Overall Survival Among Patients With Locally Advanced Gastric Cancer After Neoadjuvant Chemotherapy

IMPORTANCE

Neoadjuvant chemotherapy (NAC) is a standard treatment option for locally advanced gastric cancer (LAGC); however, the indications for adjuvant chemotherapy (AC) in patients with LAGC who received NAC remain controversial.

OBJECTIVE

To compare survival rates between patients with LAGC who received AC and those who did not after NAC followed by surgery.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, international cohort study included 353 patients with LAGC undergoing curative-intent gastrectomy after NAC at 2 tertiary referral teaching hospitals in China between June 1, 2008, and December 31, 2017. To externally validate the findings in the Chinese patients, 109 patients from the US and Italy between June 1, 2006, and June 30, 2013, were reviewed. The follow-up period of the Chinese patients was completed in December 2020, and the follow-up period of the Western patients was completed between February and July 2017. Data analysis was performed from December 1, 2020, to February 28, 2021.

EXPOSURES

Patients who received AC and those who did not were propensity score matched to evaluate the association of AC with survival.

MAIN OUTCOMES AND MEASURES

Overall survival (OS), disease-free survival, and disease-specific survival.

RESULTS

Of 353 patients from China (275 [78.1%] male; mean [SD] age, 58.0 [10.7] years), 262 (74.1%) received AC and 91 (25.9%) did not. After propensity score matching, the 3-year OS was significantly higher in patients who received AC (60.1%; 95% CI, 53.1%-68.1%) than in those who did not (49.3%; 95% CI, 39.8%-61.0%) (P = .02). Lymph node ratio (LNR) was significantly associated with AC benefit (P < .001 for interaction), and a plot of the interaction between LNR and AC demonstrated that AC was associated with improved OS in patients with higher (≥9%) LNRs (3-year OS: 46.6% vs 21.7%; P < .001), but not in patients with LNRs less than 9% (3-year OS: 73.9% vs 71.3%; P = .30). When stratified by AC cycles, only those patients who completed at least 4 AC cycles exhibited a significant survival benefit in the 6-month (hazard ratio, 0.56; 95% CI, 0.33-0.96; P = .03) and 9-month landmark analysis (hazard ratio, 0.50; 95% CI, 0.27-0.94; P = .03). In the external cohort, improved OS with AC administration was also found in patients with LNRs of 9% or greater (3-year OS: 53.0% vs 26.3%; P = .04).

CONCLUSIONS AND RELEVANCE

In this cohort study, the administration of AC after NAC and resection of LAGC was associated with improved prognosis in patients with LNRs of 9% or greater. These findings suggest that LNR might be valuable in AC selection in future decision-making processes.

Laparoscopic vs. Open Gastrectomy for Locally Advanced Gastric Cancer: A Propensity Score-Matched Retrospective Case-Control Study

Introduction: Minimally invasive surgery has been increasingly used in the treatment of gastric cancer. While laparoscopic gastrectomy has become standard therapy for early-stage gastric cancer, especially in Asian countries, the use of minimally invasive techniques has not attained the same widespread acceptance for the treatment of more advanced tumours, principally due to existing concerns about its feasibility and oncological adequacy. We aimed to examine the safety and oncological effectiveness of laparoscopic technique with radical intent for the treatment of patients with locally advanced gastric cancer by comparing short-term surgical and oncologic outcomes of laparoscopic versus open gastrectomy with D2 lymphadenectomy at two Western regional institutions. Methods: The trial was designed as a retrospective comparative matched case-control study for postoperative pathological diagnoses of locally advanced gastric carcinoma. Between January 2015 and September 2021, 120 consecutive patients who underwent curative-intent laparoscopic gastrectomy with D2 lymph node dissection were retrospectively recruited and compared with 120 patients who received open gastrectomy. In order to obtain a comparison that was as homogeneous as possible, the equal control group of pairing (1:1) patients submitted to open gastrectomy who matched those of the laparoscopic group was statistically generated by using a propensity matched score method. The following potential confounder factors were aligned: age, gender, Body Mass Index (BMI), comorbidity, ASA, adjuvant therapy, tumour location, type of gastrectomy, and pT stage. Patient demographics, operative findings, pathologic characteristics, and short-term outcomes were analyzed. Results: In the case-control study, the two groups were clearly comparable with respect to matched variables, as was expected given the intentional primary selective criteria. No statistically significant differences were revealed in overall complications (16.7% vs. 20.8%, p = 0.489), rate of reoperation (3.3% vs. 2.5%, p = 0.714), and mortality (4.2% vs. 3.3%, p = 0.987) within 30 days. Pulmonary infection and wound complications were observed more frequently in the OG group (0.8% vs. 4.2%, p < 0.01, for each of these two categories). Anastomotic and duodenal stump leakage occurred in 5.8% of the patients after laparoscopic gastrectomy and in 3.3% after open procedure (p = 0.072). The laparoscopic approach was associated with a significantly longer operative time (212 vs. 192 min, p < 0.05) but shorter postoperative length of stay (9.1 vs. 11.6 days, p < 0.001). The mean number of resected lymph nodes after D2 dissection (31.4 vs. 33.3, p = 0.134) and clearance of surgical margins (97.5% vs. 95.8%, p = 0.432) were equivalent between the groups. Conclusion: Laparoscopic gastrectomy with D2 nodal dissection appears to be safe and feasible in terms of perioperative morbidity for locally advanced gastric cancer, with comparable oncological equivalency with respect to traditional open surgery.

Comparison of estimated treatment effects between randomized controlled trials, case-matched, and cohort studies on laparoscopic versus open distal gastrectomy for advanced gastric cancer: a systematic review and meta-analysis

PURPOSE

In actual surgical research, case-matched studies are frequently conducted as an alternative to randomized controlled trials (RCTs). However, it is still unclear what differences there are between RCTs and case-matched studies in upper gastrointestinal surgery, and clarifying them is a very important clinical issue. Thus, the purpose of this study was to investigate estimated treatment effects between RCTs, case-matched studies, and cohort studies regarding laparoscopic distal gastrectomy (LDG) for advanced gastric cancer (AGC).

METHODS

We searched the PubMed, Cochrane Central Register of Controlled Trials, and Web of Science databases for studies that compared LDG versus open distal gastrectomy for AGC published from the inception of the databases until July 2021. A meta-analysis was performed using the Review Manager version 5.3 software program from the Cochrane Collaboration, and six short-term outcomes and three long-term outcomes were assessed.

RESULTS

Twenty-three studies with 13698 patients were included. There was no difference in estimated treatment effects between RCTs and case-matched studies for all outcomes except for the number of retrieved lymph nodes and postoperative complications. In terms of intraoperative blood loss, postoperative hospital stay, number of retrieved lymph nodes, and recurrence, observational studies tended to overestimate the treatment effects.

CONCLUSION

The estimated treatment effects of LDG for AGC in the case-matched study were almost the same as in the RCTs. However, to assess the true magnitude of the treatment effect, the design and actual implementation of the analysis must be critically evaluated.

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

BACKGROUND

Despite many developments, postoperative bile leakage (POBL) remains a relatively common postoperative complication after laparoscopic liver resection (LLR) and open liver resection (OLR). This study aimed to assess the incidence and clinical impact of POBL in patients undergoing LLR and OLR in a large international multicenter cohort using a propensity score-matched analysis.

STUDY DESIGN

Patients undergoing LLR or OLR for all indications between January 2000 and October 2019 were retrospectively analyzed using a large, international, multicenter liver database including data from 15 tertiary referral centers. Primary outcome was clinically relevant POBL (CR-POBL), defined as Grade B/C POBL.

RESULTS

Overall, 13,379 patients met the inclusion criteria and were included in the analysis (6,369 LLR and 7,010 OLR), with 6.0% POBL. After propensity score matching, a total of 3,563 LLR patients were matched to 3,563 OLR patients. In both groups, propensity score matching accounted for similar extent and types of resections. The incidence of CR-POBL was significantly lower in patients after LLR as compared with patients after OLR (2.6% vs 6.0%; p < 0.001). Among the subgroup of patients with CR-POBL, patients after LLR experienced less severe (non-POBL) postoperative complications (10.1% vs 20.9%; p = 0.028), a shorter hospital stay (12.5 vs 17 days; p = 0.001), and a lower 90-day/in-hospital mortality (0% vs 5.4%; p = 0.027) as compared with patients after OLR with CR-POBL.

CONCLUSION

Patients after LLR seem to experience a lower rate of CR-POBL as compared with the open approach. Our findings suggest that in patients after LLR, the clinical impact of CR-POBL is less than after OLR.

Trauma Risk Score Matching for Observational Studies in Orthopedic Trauma

OBJECTIVES

To determine if matching by trauma risk score is non-inferior to matching by chronic comorbidities and/or a combination of demographic and patient characteristics in observational studies of acute trauma in a hip fracture model.

DESIGN

Retrospective cohort study SETTING: Level-1 Trauma Center PATIENTS: 1,590 hip fracture [AO/OTA 31A and 31B] patients age 55 and over treated between October 2014 and February 2020 at 4 hospitals within a single academic medical center.

INTERVENTION

Repeatedly matching randomized subsets of patients by (1) Score for Trauma Triage in Geriatric and Middle-Aged (STTGMA), (2) Charlson Comorbidity Index (CCI), or (3) a combination of sex, age, CCI and body mass index (BMI).

MAIN OUTCOME MEASUREMENTS

"Matching failures" where rate of significant differences in variables of matched cohorts exceeds the 5% expected by chance.

RESULTS

STTGMA and combination matching resulted in no "matching failures". Matching by CCI alone resulted in "matching failures" of BMI, ASA class, STTGMA, major complications, sepsis, pneumonia, acute respiratory failure, and 90-day readmission.

CONCLUSIONS

STTGMA matching in observational cohort studies is less likely to yield significant differences of demographics and outcomes than CCI matching. STTGMA matching is noninferior to matching a combination of demographic variables optimized for each treatment cohort. STTGMA matching is apt to reflect equipoise of health at admission and outcome likelihood in observational cohort studies of orthopedic trauma, while maintaining consistent weighting of demographic and injury characteristic variables that may expand the generalizability of these studies.

LEVEL OF EVIDENCE

Level III.

Safety of anastomoses in colorectal cancer surgery in octogenarians: a prospective cohort study with propensity score matching

Background

Up to 20 per cent of all operations for patients with colorectal cancer (CRC) are performed in octogenarians. Anastomotic leakage is a leading cause of morbidity and death after resection for CRC. The aim of this study was to assess the rate of anastomosis creation, the risk of anastomotic leakage and death in surgery for left-sided CRC in elderly patients.

Methods

This prospective cohort study compared patients less than 80 and 80 or more years with left-sided CRC resection performed between 2013 and 2019. Data were provided from a risk-adjusted surgical quality-assessment system with 219 participating centres in Germany. Outcome measures were the rate of anastomoses, anastomotic leakages, death at 30 days and 2-year overall survival (OS). Propensity score matching was used to control for selection bias and compare subgroups of patients of less than 80 and 80 or more years.

Results

Out of 18 959 patients, some 3169 (16.7 per cent) were octogenarians. Octogenarians were less likely to receive anastomoses (82.0 versus 92.9 per cent, P < 0.001; odds ratio 0.50 (95 per cent c.i. 0.44 to 0.58), P < 0.001). The rate of anastomotic leakages did not differ between age groups (8.6 versus 9.7 per cent, P = 0.084), but 30-day mortality rate after leakage was significantly higher in octogenarians (15.8 versus 3.5 per cent, P < 0.001). Overall, anastomotic leakage was the strongest predictor for death (odds ratio 4.95 (95 per cent c.i. 3.66 to 6.66), P < 0.001). In the subgroup with no leakage, octogenarians had a lower 2-year OS rate than younger patients (71 versus 87 per cent, P < 0.001), and in the population with anastomotic leakage, the 2-year OS was 80 per cent in younger and 43 per cent in elderly patients (P < 0.001). After propensity score matching, older age remained predictive for not receiving an anastomosis (odds ratio 0.54 (95 per cent c.i. 0.46 to 0.63), P < 0.001) and for death (odds ratio 2.60 (95 per cent c.i. 1.78 to 3.84), P < 0.001), but not for the occurrence of leakages (odds ratio 0.94 (95 per cent c.i. 0.76 to 1.15), P = 0.524).

Conclusion

Anastomotic leakage is not more common in octogenarians, but an age of 80 years or older is an independent factor for not receiving an anastomosis in surgery for left-sided CRC. The mortality rate in the case of leakage in octogenarians was reported to exceed 15 per cent.

A propensity score-matched analysis of laparoscopic versus open surgical radical resection for gastric gastrointestinal stromal tumor

BACKGROUND

Surgery is the mainstay of treatment for gastric gastrointestinal stromal tumours (GIST). However, the choice of surgical approach for gastric GIST remains controversial.

AIMS AND OBJECTIVES

To evaluate the short- and long-term efficacies of laparoscopic surgery versus conventional open surgery for gastric GIST.

MATERIALS AND METHODS

We retrospectively reviewed 148 patients with gastric GIST at our hospital between January 2013 and January 2020. The patients were categorised into the following two groups based on the surgery performed: The laparoscopic surgery group (LG) and the open surgery group (OG). Differences in the tumour size, surgical procedures and modified National Institutes of Health classification were statistically significant. To balance the intergroup confounders, we performed 1:1 propensity score matching (PSM).

RESULTS

A total of 104 patients were selected after PSM (52 in each group). We focused on the short- and long- term outcomes of patients. The baseline information was balanced between the two groups after PSM. The LG benefited from the advantages of a minimally invasive surgery (faster gastrointestinal function recovery, shorter time to drainage tube removal, less blood loss and shorter hospitalisation period), however, it also had high treatment costs. Moreover, both laparoscopic and open surgeries resulted in similar intra-operative and post-operative complications rates, overall survival time and disease-free survival time.

CONCLUSION

Laparoscopic resection is feasible and oncologically safe for GIST. However, more prospective studies are required to confirm the findings.

The impact of synchronous liver resection on the risk of anastomotic leakage following elective colorectal resection. A propensity score match analysis on behalf of the iCral study group

INTRODUCTION

how best to manage patients with colorectal cancer and synchronous liver metastasis is still controversial, with specific concerns of increased risk of postoperative complications following combined resection. We aimed at analyzing the influence of combined liver resection on the risk of anastomotic leak (AL) following colorectal resection.

METHODS

we reviewed the iCral prospectively maintained database to compare the relative risk of AL of patients undergoing colorectal resection for cancer to that of patients receiving simultaneous liver and colorectal resection for cancer with isolated hepatic metastases. The incidence of AL was the primary outcome of the analysis. Perioperative details and postoperative complications were also appraised.

RESULTS

out of a total of 996 patients who underwent colorectal resection for cancer, 206 receiving isolated colorectal resection were compared with a matched group of 53 patients undergoing simultaneous liver and colorectal resection. Combined surgery had greater operative time and resulted in longer postoperative hospitalization compared to colorectal resection alone. The proportion of overall morbidity following combined resection was significantly higher than after isolated colorectal resection (56.6% vs. 37.9%, p = 0.021). Overall, the two groups of patients did not differ neither on the rate of major postoperative complications, nor in terms of AL (9.4% vs. 6.3%, p = 0.381). At specific multivariate analysis, the duration of surgery was the only risk factor independently associated with the likelihood of AL.

CONCLUSIONS

combining hepatic with colorectal resection for the treatment of synchronous liver metastasis from colorectal cancer does not increase significantly the incidence of AL.

Prognostic implications of extranodal extension in papillary thyroid carcinomas: A propensity score matching analysis and proposal for incorporation into current tumor, lymph node, metastasis staging

BACKGROUND

The current American Joint Committee on Cancer tumor, lymph node, metastasis cancer staging system for papillary thyroid carcinoma places low weight on extranodal extension. This study examined the prognostic implications of extranodal extension in papillary thyroid carcinoma patients and attempted to design a new staging system incorporating extranodal extension.

METHODS

We reviewed data from 6,165 consecutive papillary thyroid carcinoma patients from 2012 to 2018. Patients with extrathyroidal extension or extranodal extension were included and then divided into 3 groups: extrathyroidal extension (papillary thyroid carcinoma with extrathyroidal extension but without extranodal extension, N = 457); extranodal extension (papillary thyroid carcinoma with extranodal extension but without extrathyroidal extension, N = 116); and extrathyroidal extension and extranodal extension (papillary thyroid carcinoma with both extrathyroidal extension and extranodal extension, N = 116). Recurrence-free survival and cancer-specific survival were compared before and after adjusting for differences using propensity score matching owing to observed heterogeneity in baseline characteristics in the original cohort. Recurrence-free survival and cancer-specific survival were also compared between patients with and without extranodal extension after matching at a 1:1 ratio. Cox proportional hazards regression analyses were used to identify the relationships of factors associated with structural recurrent disease in the node-positive subset. Then a new staging system incorporating extranodal extension was established, and the discrimination of the new staging system for recurrence-free survival and cancer-specific survival was investigated.

RESULTS

Of the 6,165 patients with papillary thyroid carcinoma, extrathyroidal extension was found in 573 (9.3%) patients, and extranodal extension was observed in 232 (3.8%) patients. The recurrence-free survival and cancer-specific survival rates of patients with extranodal extension were similar to those of patients with extrathyroidal extension (all P > .05). Patients with extrathyroidal extension and extranodal extension experienced worse recurrence-free survival than patients with extrathyroidal extension or extranodal extension and even worse cancer-specific survival than patients with extrathyroidal extension (all P < .05). The recurrence-free survival and cancer-specific survival rates of patients with extranodal extension were worse than those of patients without extranodal extension (P = .003; P = .048). Cox proportional hazards regression analysis demonstrated that after propensity score matching, extranodal extension (hazard ratio 1.911; 95% confidence interval 1.568-3.609; P < .001) remained an independent predictor of structural recurrent disease in patients with node-positive papillary thyroid carcinoma. After incorporating extranodal extension into the current tumor, lymph node, metastasis classification, the new staging system presented a better discrimination for recurrence-free survival and cancer-specific survival for those with lymph node metastasis.

CONCLUSION

Papillary thyroid carcinoma patients with extranodal extension present worse prognosis, and incorporating extranodal extension in tumor, lymph node, metastasis classification identifies poor-risk patients more accurately.

Case-control analysis of prehospital death and prolonged field care survival during recent US military combat operations

BACKGROUND

Quantification of medical interventions administered during prolonged field care (PFC) is necessary to inform training and planning.

MATERIALS AND METHODS

Retrospective cohort study of Department of Defense Trauma Registry casualties with maximum Abbreviated Injury Scale (MAIS) score of 2 or greater and prehospital records during combat operations 2007 to 2015; US military nonsurvivors were linked to Armed Forces Medical Examiner System data. Medical interventions administered to survivors of 4 hours to 72 hours of PFC and nonsurvivors who died prehospital were compared by frequency-matching on mechanism (explosive, firearm, other), injury type (penetrating, blunt) and injured body regions with MAIS score of 3 or greater. Covariates for adjustment included age, sex, military Service, shock, Glasgow Coma Scale, transport team, MAIS and Injury Severity Score (ISS). Sensitivity analysis focused on US military subgroup with AIS/ISS assigned to nonsurvivors after autopsy.

RESULTS

The total inception cohort included 16,202 casualties (5,269 US military, 10,809 non-US military), 64% Afghanistan, 36% Iraq. Of US military, 734 deaths occurred within 30 days, nearly 90% occurred within 4 hours of injury. There were 3,222 casualties (1,111 US military, 2,111 non-US military) documented for prehospital care and died prehospital (691) or survived 4 hours to 72 hours of PFC (2,531). Twenty-five percent (815/3,222) received advanced airway, 18% (583) ventilatory support, 9% (281) tourniquet. Twenty-three percent (725) received blood transfusions within 24 hours. Of the matched cohort (1,233 survivors, 490 nonsurvivors), differences were observed in care (survivors received more warming, intravenous fluids, sedation, mechanical ventilation, narcotics, antibiotics; nonsurvivors received more intubations, tourniquets, intraosseous fluids, cardiopulmonary resuscitation). Sensitivity analysis focused on US military (732 survivors, 379 nonsurvivors) showed no significant differences in prehospital interventions. Without autopsy information, the ISS of nonsurvivors significantly underestimated injury severity.

CONCLUSION

Tourniquets, blood transfusion, airway, and ventilatory support are frequently required interventions for the seriously injured. Prolonged field care should direct resources, technology, and training to field technology for sustained resuscitation, airway, and breathing support in the austere environment.

LEVEL OF EVIDENCE

Prognostic, Level III.

Implementation of Enhanced Recovery After Surgery (ERAS) protocol for elderly patients receiving surgery for intertrochanteric fracture: a propensity score-matched analysis

Purpose

Enhanced Recovery After Surgery (ERAS) is a multimodal approach to perioperative care that aims to reduce patient perioperative complications, accelerate patient recovery, and improve patient satisfaction by refining and optimizing all perioperative management processes. By comparing two groups of patients before and after the implementation of ERAS for intertrochanteric fracture (ITF) with a matching analysis of propensity score (PS), we aimed to demonstrate that the implementation of ERAS protocol shortens the length of hospital stay (LOS), reduces pain, decreases the incidence of postoperative complications, and promotes functional recovery of the joint.

Methods

We selected 2 periods of 1 year, before (n=98patients) and after ERAS implementation (n=92patients). Data were collected on patient demographics, operative and perioperative details, LOS, VAS score, Harris score, and 30-day complications. ERAS-trained nurses are engaged to support patients at each step of the pre/per/postoperative process, including completing a satisfaction survey, with the help of a mobile app. PS analyses were used for dealing with confounding bias in this retrospective observational study.

Results

After PS matching, the outcomes of 124 well-balanced pairs of patients were compared (conventional vs ERAS). LOS was significantly reduced from 24.3±3.9 to 15.2±2.9 days (P<0.001). With the same preoperative VAS scores, we found that patients in the ERAS group had significantly lower postoperative VAS scores than those in the conventional group at days 3 and 7 (P<0.001), but the difference was not statistically significant at day 14. patients in the ERAS group had higher Harris scores than those in the conventional group at 1 and 3 months, but the difference was not significant at 6 months. In addition, we found that only one patient in the ERAS group developed complications, while nine patients in the conventional group developed different complications. There was no significant difference concerning the satisfaction survey.

Conclusion

The introduction of ERAS for ITF in our institution has resulted in a significant decrease in LOS, alleviated patient pain, promoted early recovery of patient’s hip function while effectively preventing complications, and obtained patient satisfaction.

Procedure-specific Training for Robot-assisted Distal Pancreatectomy

OBJECTIVE

To train practicing surgeons in robot-assisted distal pancreatectomy (RADP) and assess the impact on 5 domains of healthcare quality.

BACKGROUND

RADP may reduce the treatment burden compared with open distal pancreatectomy (ODP), but studies on institutional training and implementation programs are scarce.

METHODS

A retrospective, single-center, cohort study evaluating surgical performance during a procedure-specific training program for RADP (January 2006 to September 2017). Baseline and unadjusted outcomes were compared "before training" (ODP only; June 2012). Exclusion criteria were neoadjuvant therapy, vascular- and unrelated organ resection. Run charts evaluated index length of stay (LOS) and 90-day comprehensive complication index. Cumulative sum charts of operating time (OT) assessed institutional learning. Adjusted outcomes after RADP versus ODP were compared using a secondary propensity-score-matched (1:1) analysis to determine clinical efficacy.

RESULTS

After screening, 237 patients were included in the before-training (133 ODP) and after-training (24 ODP, 80 RADP) groups. After initiation of training, mean perioperative blood loss decreased (-255 mL, P<0.001), OT increased (+65 min, P < 0.001), and median LOS decreased (-1 day, P < 0.001). All other outcomes remained similar (P>0.05). Over time, there were nonrandom (P < 0.05) downward shifts in LOS, while comprehensive complication index was unaffected. We observed 3 learning curve phases in OT: accumulation (<31 cases), optimization (case 31-65), and a steady-state (>65 cases). Propensity-score-matching confirmed reductions in index and 90-day LOS and blood loss with similar morbidity between RADP and ODP.

CONCLUSION

Supervised procedure-specific training enabled successful implementation of RADP by practicing surgeons with immediate improvements in length of stay, without adverse effects on safety.

The impact of additional margin coagulation with radiofrequency in liver resections with subcentimetric margin: can we improve the oncological results? A propensity score matching study

BACKGROUND

Whereas the usefulness of radiofrequency (RF) energy as haemostatic method in liver surgery has become well established in the last decades, its intentional application on resection margins with the aim of reducing local recurrence is still debatable. Our goal was to compare the impact of an additional application of RF energy on the top of the resection surface, namely additional margin coagulation (AMC), on local recurrence (LR) when subjected to a subcentimeter margin.

METHODS

We retrospectively analyzed 185 patients out of a whole cohort of 283 patients who underwent radical hepatic resection with subcentimetric margin. After propensity score adjustment, patients were classified into two balanced groups according to whether RF was applied or not.

RESULTS

No significant differences were observed within groups in baseline characteristics after PSM adjustment. The LR rate was significantly higher in the Control than AMC Group: 12 patients (14.5%) vs. 4 patients (4.8%) (p = 0.039). The estimated 1, 3, and 5-year LR-free survival rates of patients in the Control and AMC Group were: 93.5%, 86.0%, 81.0% and 98.8%, 97.2%, 91.9%, respectively (p = 0.049). Univariate Cox analyses indicated that the use of the RF applicator was significantly associated with lower LR (HR = 0.29, 95% confidence interval 0.093-0.906, p = 0.033). The Control Group showed smaller coagulation widths than the AMC group (p < 0.001).

CONCLUSIONS

An additional application of RF on the top of the resection surface is associated with less local hepatic recurrence than the use of conventional techniques.

Comparison of the outcomes of cytoreductive surgery versus surgery plus hyperthermic intraperitoneal chemotherapy for peritoneal carcinomatosis: a propensity score matching analysis

BACKGROUND

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are effective treatment options for selected patients with peritoneal carcinomatosis (PC). We compared the short-term outcomes of surgery plus HIPEC and CRS alone for PC.

METHODS

We retrospectively examined patients who underwent CRS-HIPEC for PC at a single center from 2014 to 2019 using the Chinese CRS-HIPEC patient database at our institution. Patients were divided into two groups: surgery plus HIPEC (450) and surgery alone (200). A 1:1 propensity score matching (PSM) analysis was performed. The postoperative outcomes, mortality, and length of hospital stay were compared between the surgery plus HIPEC and CRS alone groups.

RESULTS

Propensity scoring generated 162 pairs. There was no statistically significant difference in the 30-day mortality rate between the groups (0% vs 0%, P = 1.000), and the morbidity rates were similar in both groups (7.4% vs 8.0%, P = 0.835). The surgery plus HIPEC group had a longer operative time (247.81 ± 64.70 vs 184.55 ± 29.56, P ≤ 0.001) and a slightly longer postoperative hospital stay (14.64 ± 5.24 vs 12.59 ± 3.76, P ≤ 0.001). No other baseline characteristics were significantly different.

CONCLUSIONS

Surgery plus HIPEC is feasible for select patients and is associated with prolonged surgery times and prolonged hospital stays, and there is no significant difference in mortality rates or postoperative outcomes.

Full-Endoscopic Lumbar Decompression versus Open Decompression and Fusion Surgery for the Lumbar Spinal Stenosis: A 3-Year Follow-Up Study

Purpose

Compare the efficacy of full-endoscopic lumbar decompression surgery (FELDS) and open decompression and fusion surgery (ODFS) for lumbar spinal stenosis (LSS).

Patients and Methods

A retrospective analysis of 358 LSS patients treated by FELDS (“FELD” group) or ODFS (“open” group) was undertaken. There were 177 patients in the FELDS group with a mean age of 65.47±9.26 years and 181 patients in the open group with a mean age of 64.18±10.24 years. Duration of follow-up was 38.63±11.88 months in the FELDS group and 38.56±12.29 months in the open group. Visual analog scale (VAS) score, Oswestry Disability Index (ODI), and Modified MacNab criteria were used to access clinical outcomes. Surgical outcomes (duration of surgical procedure, blood loss, complications, duration of postoperative hospital stay (DOPHS), prevalence of revision procedures) were evaluated. Magnetic resonance imaging was used to evaluate the change in the Pfirrmann grade at adjacent segments.

Results

VAS score (leg and back) and ODI improved significantly in both groups (P<0.001). Success rate reached 86.55% and 90.60% in the FELDS group and open group (P>0.05), respectively. Procedure duration (84.12 vs 112.08 min), blood loss (7.97 vs 279.67 mL), and DOPHS (2.68 vs 4.78 days) of the FELDS group were significantly better than those of the open group (P<0.05). Total prevalence of complications and procedure revisions was 14.69% and 10.73% in the FELD group, respectively, but did not show a significant difference with that in the open group (12.15% and 9.39%, respectively). The Pfirrmann grade increased in 13.04% of adjacent segments in the FELDS group, significantly better than that in the open group (32.67%) (P<0.05).

Conclusion

FELDS had the same efficacy as ODFS for LSS treatment. FELDS had the advantages of minimal invasiveness, less surgical trauma, rapid recovery, and lower risk of degeneration of adjacent segments compared with that of ODFS.

Admission discipline and timing of admission may influence outcomes for gastrointestinal bleeding patients

BACKGROUND

Bleeding of the gastrointestinal tract (BGIT) is a common gastrointestinal emergency. There is no consensus whether this condition should be admitted to medical or surgical discipline. Timing of presentation may also impact patient outcomes due to differences in healthcare resource availability. This study thus aims to investigate the impact of admitting discipline and timing of admission on patient outcomes in BGIT.

METHODS

A 2-year tertiary institution database was retrospectively reviewed. Outcome measures included 30-day mortality, 30-day readmissions and rebleeding requiring repeat endoscopic, angiographic or surgical interventions. Secondary outcome measures included time to endoscopy, percutaneous angiographic interventions and surgery. The effect of admission discipline (medical versus surgical) and time of admission (office-hours versus after office-hours) were analysed using a propensity-score-adjusted estimate.

RESULTS

A total of 1384 patients were included for analysis, medical (n = 853), surgical (n = 530); during office-hours (n = 785) and after office-hours (n = 595). After propensity-score-adjusted analysis, no significant differences in mortality or readmissions were noted between medical or surgical admissions. Patients admitted under surgery were less likely to sustain rebleeding (P = 0.004) for lower BGIT and had an earlier time to endoscopy for upper BGIT (P = 0.04). Patients admitted after office-hours had similar outcomes with those admitted during office hours apart from a delay in time to endoscopy (P = 0.02).

CONCLUSION

For BGIT patients, admission to a surgical discipline compared to a medical discipline appeared to have at least equivalent patient outcomes. Patients presenting with BGIT after office-hours were more likely to experience a delay to endoscopy, although it did not affect patient mortality.

International multicenter propensity score matched study on laparoscopic versus open left lateral sectionectomy

BACKGROUND

Despite a lack of high-level evidence, current guidelines recommend laparoscopic left lateral sectionectomy (LLLS) as the routine approach over open LLS (OLLS). Randomized studies and propensity score matched studies on LLLS vs OLLS for all indications, including malignancy, are lacking.

METHODS

This international multicenter propensity score matched retrospective cohort study included consecutive patients undergoing LLLS or OLLS in six centers from three European countries (January 2000-December 2016). Propensity scores were calculated based on nine preoperative variables and LLLS and OLLS were matched in a 1:1 ratio. Short-term operative outcomes were compared using paired tests.

RESULTS

A total of 560 patients were included. Out of 200 LLLS, 139 could be matched to 139 OLLS. After matching, baseline characteristics were well balanced. LLLS was associated with shorter operative time (144 (110-200) vs 199 (138-283) minutes, P < 0.001), less blood loss (100 (50-300) vs 350 (100-750) mL, P = 0.005) and a 3-day shorter postoperative hospital stay (4 (3-7) vs 7 (5-9) days, P < 0.001).

CONCLUSION

This international multicenter propensity score matched study confirms the superiority of LLLS over OLLS based on shorter postoperative hospital stay, operative time, and less blood loss thus validating current guideline advice.

Switching monopolar radiofrequency ablation improves long-term outcomes of medium-sized hepatocellular carcinoma

OBJECTIVES

Radiofrequency ablation (RFA) of medium-sized (3-5 cm) hepatocellular carcinoma (HCC) is suboptimal. Switching monopolar RFA (SW-RFA) enlarges the ablative volume to better cover larger tumors. This study aims to compare the long-term outcomes of medium-sized HCC treated by either SW-RFA or single-monopolar RFA (S-RFA).

METHODS

We retrospectively reviewed 139 cases (147 medium-size HCC) between 2008 and 2014. Under propensity score matching, a total of 43 paired patients with medium-size HCC and balanced clinical variables treated by either SW-RFA or S-RFA were selected for comparison.

RESULTS

SW-RFA showed a higher rate of achieving an adequate safety margin (p = 0.002). After a mean follow-up period of 40.4 months, SW-RFA produced significantly lower global RFA failure rates (p < 0.001) and better overall survival (p = 0.005) compared to S-RFA. SW-RFA was independently associated with a decreased risk of global RFA failure (hazard ratio [HR]: 0.136, 95% confidence interval [CI]: 0.030-0.607, p = 0.009) and improved overall survival (HR: 0.337, 95% CI: 0.152-0.747, p = 0.007). By last follow-up, the SW-RFA group maintained a superior tumor-free rate (p = 0.010) and fewer progressions to Barcelona Clinic Liver Cancer stage C (p = 0.011). Major complication rates were comparable in both groups (SW-RFA: 2.3% vs. S-RFA: 4.7%, p = 1.000).

CONCLUSIONS

The switching multi-monopolar ablation technique could be beneficial for patients with medium-sized HCCs given sustained control of larger tumors with better overall survival.

KEY POINTS

• Switching monopolar ablation could provide a sustained local tumor control and better overall survival than single-monopolar ablation for the medium-sized hepatocellular carcinoma. • Compared to single-monopolar ablation, switching monopolar ablation could create a larger homogeneous coagulation volume by using a shorter total ablation time to achieve a higher rate of adequate safety margin for a medium-sized HCC. • Patients with medium-sized HCC can be maintained at a higher rate of tumor-free status and at a lower risk of progression into BCLC stage C in the follow-up period after ablation by switching monopolar than by single-monopolar ablation.

Laparoscopic vs. Open Repeat Hepatectomy for Recurrent Liver Tumors: A Propensity Score-Matched Study and Meta-Analysis

Background: It remains unclear whether the short-term benefits of laparoscopic repeat hepatectomy (LRH) accrue to patients with recurrent liver tumors. The present study aimed to report our own center's experience and perform a meta-analysis to evaluate the safety and feasibility of LRH in comparison with open repeat hepatectomy (ORH) for treating recurrent liver tumors.

Patients and Methods: A propensity score–matched study was performed including 426 patients receiving LRH or ORH for recurrent hepatocellular carcinoma between January 2017 and December 2018. Surgical outcomes and perioperative inflammation-based markers, including monocyte-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and systemic immune–inflammation index were collected from medical records and analyzed. Additionally, a systematic literature review was performed to identify relevant studies in PubMed, EMBASE, Web of Science, and Cochrane library databases up to October 1, 2020. Information including patient demographics, pathologic characteristics, and short-term outcomes was extracted and analyzed using random- or fixed-effects models.

Results: Of 68 LRHs, 57 were matched with an ORH finally. Our study demonstrated that LRH was significantly associated with less intraoperative blood loss (50 vs. 100 mL; P < 0.001), lower rate of hepatic inflow occlusion (10.52 vs. 33.3%; P = 0.003), and shorter postoperative hospital stay (5 vs. 6 days; P = 0.001) after 1:1 propensity score matching. The operation time, rate of blood transfusion, and postoperative complications were similar between the two groups. Moreover, all four inflammation-based markers were significantly lower in LRH group on postoperative day 1. In the meta-analysis, a total of 12 studies comprising 1,315 patients receiving repeat hepatectomy met the selection criteria. Similar to our own study, the meta-analysis showed shorter hospital stay [standard mean difference (SMD) = −0.51, 95% confidence interval (CI) = −0.79 to −0.22, P < 0.001], less intraoperative blood loss (SMD = −0.79, 95% CI = −1.11 to −0.47, P < 0.001), and lower rate of major postoperative complications [odds ratio (OR) = 0.35, 95% CI = 0.19–0.66, P = 0.001] in the LRH group. There was no difference in the field of overall postoperative complication and operation time between LRH and ORH groups.

Conclusion: Compared with ORH, LRH results in relatively better surgical outcomes and faster postoperative recovery. It could be considered a feasible and effective option for the treatment of recurrent liver tumors.

Difference in surgical outcomes of rectal cancer by study design: meta-analyses of randomized clinical trials, case-matched studies, and cohort studies

Background

RCTs are considered the standard in surgical research, whereas case-matched studies and propensity score matching studies are conducted as an alternative option. Both study designs have been used to investigate the potential superiority of robotic surgery over laparoscopic surgery for rectal cancer. However, no conclusion has been reached regarding whether there are differences in findings according to study design. This study aimed to examine similarities and differences in findings relating to robotic surgery for rectal cancer by study design.

Methods

A comprehensive literature search was conducted using PubMed, Scopus, and Cochrane CENTRAL to identify RCTs, case-matched studies, and cohort studies that compared robotic versus laparoscopic surgery for rectal cancer. Primary outcomes were incidence of postoperative overall complications, incidence of anastomotic leakage, and postoperative mortality. Meta-analyses were performed for each study design using a random-effects model.

Results

Fifty-nine articles were identified and reviewed. No differences were observed in incidence of anastomotic leakage, mortality, rate of positive circumferential resection margins, conversion rate, and duration of operation by study design. With respect to the incidence of postoperative overall complications and duration of hospital stay, the superiority of robotic surgery was most evident in cohort studies (risk ratio (RR) 0.83, 95 per cent c.i. 0.74 to 0.92, P < 0.001; mean difference (MD) –1.11 (95 per cent c.i. –1.86 to –0.36) days, P = 0.004; respectively), and least evident in RCTs (RR 1.12, 0.91 to 1.38, P = 0.27; MD –0.28 (–1.44 to 0.88) days, P = 0.64; respectively).

Conclusion

Results of case-matched studies were often similar to those of RCTs in terms of outcomes of robotic surgery for rectal cancer. However, case-matched studies occasionally overestimated the effects of interventions compared with RCTs.

Laparoscopic and open liver resection for hepatocellular carcinoma with Child-Pugh B cirrhosis: multicentre propensity score-matched study

BACKGROUND

Laparoscopic liver resection for hepatocellular carcinoma (HCC) in Child-Pugh A cirrhosis has been demonstrated as beneficial. However, the role of laparoscopy in Child-Pugh B cirrhosis is undetermined. The aim of this retrospective cohort study was to compare open and laparoscopic resection for HCC with Child-Pugh B cirrhosis.

METHODS

Data on liver resections were gathered from 17 centres. A 1 : 1 propensity score matching was performed according to 17 predefined variables.

RESULTS

Of 382 available liver resections, 100 laparoscopic and 100 open resections were matched and analysed. The 90-day postoperative mortality rate was similar in open and laparoscopic groups (4.0 versus 2.0 per cent respectively; P = 0.687). Laparoscopy was associated with lower blood loss (median 110 ml versus 400 ml in the open group; P = 0.004), less morbidity (38.0 versus 51.0 per cent respectively; P = 0.041) and fewer major complications (7.0 versus 21.0 per cent; P = 0.010), and ascites was lower on postoperative days 1, 3 and 5. For laparoscopic resections, patients with portal hypertension developed more complications than those without (26 versus 12 per cent respectively; P = 0.002), and patients with a Child-Pugh B9 score had higher morbidity rates than those with B8 and B7 (7 of 8, 10 of 16 and 21 of 76 respectively; P < 0.001). Median hospital stay was 7.5 (range 2-243) days for laparoscopic liver resection and 18 (3-104) days for the open approach (P = 0.058). The 5-year overall survival rate was 47 per cent for open and 65 per cent for laparoscopic resection (P = 0.142). The 5-year disease-free survival rate was 32 and 37 per cent respectively (P = 0.742).

CONCLUSION

Patients without preoperative portal hypertension and Child-Pugh B7 cirrhosis may benefit most from laparoscopic liver surgery.

Quality of life and surgical outcome of ABBA versus EndoCATS endoscopic thyroid surgery: a single center experience

Background

Thyroid surgery is often performed, especially in young female patients. As patient satisfaction become more and more important, different extra-cervical “remote” approaches have evolved to avoid visible scars in the neck for better cosmetic outcome. The most common remote approaches are the transaxillary and retroauricular. Aim of this work is to compare Endoscopic Cephalic Access Thyroid Surgery (EndoCATS) and axillo-bilateral-breast approach (ABBA) to standard open procedures regarding perioperative outcome and in addition to control cohorts regarding quality of life (QoL) and patient satisfaction.

Methods

In a single center, 59 EndoCATS und 52 ABBA procedures were included out of a 2 years period and compared to 225 open procedures using propensity-score matching. For the endoscopic procedures, cosmetic outcome, patient satisfaction and QoL (SF-12 questionnaire) were examined in prospective follow-up. For QoL a German standard cohort and non-surgically patients with thyroid disease were used as controls.

Result

The overall perioperative outcome was similar for all endoscopic compared to open thyroid surgeries. Surgical time was longer for endoscopic procedures. There were no cases of permanent hypoparathyroidism and no significant differences regarding temporary or permanent recurrent laryngeal nerve (RLN) palsies between open and ABBA or EndoCATS procedures (χ²; p = 0.893 and 0.840). For ABBA and EndoCATS, 89.6% and 94.2% of patients were satisfied with the surgical procedure. Regarding QoL, there was an overall significant difference in distribution for physical, but not for mental health between groups (p < 0.001 and 0.658). Both endoscopic groups performed slightly worse regarding physical health, but without significant difference between the individual groups in post hoc multiple comparison.

Conclusion

Endoscopic thyroid surgery is safe with comparable perioperative outcome in experienced high-volume centers. Patient satisfaction and cosmetic results are excellent; QoL is impaired in surgical patients, as they perform slightly worse compared to German standard cohort and non-surgical patients.

Similarities and differences between study designs in short- and long-term outcomes of laparoscopic versus open low anterior resection for rectal cancer: A systematic review and meta-analysis of randomized, case-matched, and cohort studies

AIM

Randomized controlled trials (RCT) are the gold standard in surgical research, and case-matched studies, such as studies with propensity score matching, are expected to serve as an alternative to RCT. Both study designs have been used to investigate the potential superiority of laparoscopic surgery to open surgery for rectal cancer, but it remains unclear whether there are any differences in the findings obtained using these study designs. We aimed to examine similarities and differences between findings from different study designs regarding laparoscopic surgery for rectal cancer.

METHODS

Systematic review and meta-analyses. A comprehensive literature search was conducted using PubMed, Scopus, and Cochrane. RCT, case-matched studies, and cohort studies comparing laparoscopic low anterior resection and open low anterior resection for rectal cancer were included. In total, 8 short-term outcomes and 3 long-term outcomes were assessed. Meta-analysis was conducted stratified by study design using a random-effects model.

RESULTS

Thirty-five studies were included in this review. Findings did not differ between RCT and case-matched studies for most outcomes. However, the estimated treatment effect was largest in cohort studies, intermediate in case-matched studies, and smallest in RCT for overall postoperative complications and 3-year local recurrence.

CONCLUSION

Findings from case-matched studies were similar to those from RCT in laparoscopic low anterior resection for rectal cancer. However, findings from case-matched studies were sometimes intermediate between those of RCT and unadjusted cohort studies, and case-matched studies and cohort studies have a potential to overestimate the treatment effect compared with RCT.

Laparoscopic versus open extended radical left pancreatectomy for pancreatic ductal adenocarcinoma: an international propensity-score matched study

BACKGROUND

A radical left pancreatectomy in patients with pancreatic ductal adenocarcinoma (PDAC) may require extended, multivisceral resections. The role of a laparoscopic approach in extended radical left pancreatectomy (ERLP) is unclear since comparative studies are lacking. The aim of this study was to compare outcomes after laparoscopic vs open ERLP in patients with PDAC.

METHODS

An international multicenter propensity-score matched study including patients who underwent either laparoscopic or open ERLP (L-ERLP; O-ERLP) for PDAC was performed (2007-2015). The ISGPS definition for extended resection was used. Primary outcomes were overall survival, margin negative rate (R0), and lymph node retrieval.

RESULTS

Between 2007 and 2015, 320 patients underwent ERLP in 34 centers from 12 countries (65 L-ERLP vs. 255 O-ERLP). After propensity-score matching, 44 L-ERLP could be matched to 44 O-ERLP. In the matched cohort, the conversion rate in L-ERLP group was 35%. The L-ERLP R0 resection rate (matched cohort) was comparable to O-ERLP (67% vs 48%; P = 0.063) but the lymph node yield was lower for L-ERLP than O-ERLP (median 11 vs 19, P = 0.023). L-ERLP was associated with less delayed gastric emptying (0% vs 16%, P = 0.006) and shorter hospital stay (median 9 vs 13 days, P = 0.005), as compared to O-ERLP. Outcomes were comparable for additional organ resections, vascular resections (besides splenic vessels), Clavien-Dindo grade ≥ III complications, or 90-day mortality (2% vs 2%, P = 0.973). The median overall survival was comparable between both groups (19 vs 20 months, P = 0.571). Conversion did not worsen outcomes in L-ERLP.

CONCLUSION

The laparoscopic approach may be used safely in selected patients requiring ERLP for PDAC, since morbidity, mortality, and overall survival seem comparable, as compared to O-ERLP. L-ERLP is associated with a high conversion rate and reduced lymph node yield but also with less delayed gastric emptying and a shorter hospital stay, as compared to O-ERLP.