Do we intervene less and slower in the epilepsy monitoring unit for psychogenic seizures?

PURPOSE: Individuals with psychogenic non-epileptic seizures (PNES) can be stigmatized in healthcare settings. We aimed to compare intervention rate (IR), intervention time (IT), and adverse event (AE) rate between PNES and epileptic seizures (ES) in the epilepsy monitoring unit (EMU). METHODS: We used a prospective database of consecutive admissions to our centre's EMU between August 2021 and September 2022. We excluded purely electric seizures and vague, minor spells with no EEG correlate. We therefore only included electroclinical seizures and PNES. We compared the IR, IT, and AE rate between PNES and ES, as diagnosed by an epileptologist during EEG monitoring. We performed the same comparisons between spells occurring in people admitted with a high vs low suspicion of PNES (HSP vs LSP). We also verified if ITs became longer with repeated PNES. RESULTS: We analyzed 586 spells: 43 PNES vs 543 ES, or 133 HSP vs 453 LSP. Our univariate analyses showed that IR was higher for PNES than for ES (93 % vs 61 %, p <.001) but that IT and AE rate were similar across groups. This higher IR was only apparent outside weekday daytime hours, when EEG technologists were not present. HSP did not differ from LSP in terms of IR, IT, and AE rate. As PNES accumulated in individual patients, IT tended to be longer (Spearman's correlation = 0.42; p =.012). SIGNIFICANCE: Our EMU staff did not intervene less or slower for PNES. Rather, IR was higher for PNES than for ES, but IT tended to be longer with repeat PNES.

Outcome of psychogenic non-epileptic seizures following diagnosis in the epilepsy monitoring unit.

Objective: To study the outcome of patients with psychogenic non-epileptic seizures (PNES) after their diagnosis in the epilepsy monitoring unit (EMU). Methods: Patients diagnosed in our EMU with definite PNES between January 2009 and May 2023 were contacted by phone, and those who agreed to participate were asked a set of predetermined questions. Comparative analyses were carried out on several variables before and after diagnosis: number of participants with daily PNES, number of visits to the emergency department, number of participants who consulted their general practitioner or a neurologist outside of a scheduled follow-up, number of participants who took antiseizure medications (ASMs) or psychotropic drugs, and employment status. Results: Out of the 103 patients with a definite diagnosis of PNES, 61 patients (79% female) accepted to participate in our study. The median age at PNES onset was 35 years, and the median delay to diagnosis was 3 years. Almost two-thirds (62%) were receiving ASMs and 40% psychotropic drugs. The mean stay at the EMU was 5 days. PNES diagnosis was explained to almost all patients (97%) by the end of their EMU stay and was well-accepted by most (89%). When contacted, 46% of participants no longer had PNES; 32% mentioned that their PNES had ceased immediately upon communication of the diagnosis. The median follow-up duration was 51 months. Fewer patients had daily seizures after the diagnosis (18 vs. 38%; p < 0.0455). Similarly, the median number of emergency department visits was significantly lower (0 vs. 2; p < 0.001). Only 17 patients consulted their general practitioner (vs. 40, p < 0.001) and 20 a neurologist (vs. 55, p < 0.001) after a PNES attack outside of a scheduled follow-up. The use of ASMs was also significantly reduced from 70 to 33% (p < 0.01), with only one still taking an ASM for its antiseizure properties. Significantly more participants were working at last follow-up than at PNES diagnosis (49 vs. 25%; p < 0.001). Conclusion: Our study revealed a relatively favorable long-term outcome of definite PNES diagnosed in the EMU that translated in significant reductions in PNES frequency, health care utilization and ASM use, as well as a significant increase in employment rate.

Nonaneurysmal perimesencephalic subarachnoid hemorrhage on noncontrast head CT: An accuracy, inter-rater, and intra-rater reliability study.

BACKGROUND AND PURPOSE: To evaluate the reliability and accuracy of nonaneurysmal perimesencephalic subarachnoid hemorrhage (NAPSAH) on Noncontrast Head CT (NCCT) between numerous raters. MATERIALS AND METHODS: 45 NCCT of adult patients with SAH who also had a catheter angiography (CA) were independently evaluated by 48 diverse raters; 45 raters performed a second assessment one month later. For each case, raters were asked: 1) whether they judged the bleeding pattern to be perimesencephalic; 2) whether there was blood anterior to brainstem; 3) complete filling of the anterior interhemispheric fissure (AIF); 4) extension to the lateral part of the sylvian fissure (LSF); 5) frank intraventricular hemorrhage; 6) whether in the hypothetical presence of a negative CT angiogram they would still recommend CA. An automatic NAPSAH diagnosis was also generated by combining responses to questions 2-5. Reliability was estimated using Gwet's AC1 (κG), and the relationship between the NCCT diagnosis of NAPSAH and the recommendation to perform CA using Cramer's V test. Multi-rater accuracy of NCCT in predicting negative CA was explored. RESULTS: Inter-rater reliability for the presence of NAPSAH was moderate (κG = 0.58; 95%CI: 0.47, 0.69), but improved to substantial when automatically generated (κG = 0.70; 95%CI: 0.59, 0.81). The most reliable criteria were the absence of AIF filling (κG = 0.79) and extension to LSF (κG = 0.79). Mean intra-rater reliability was substantial (κG = 0.65). NAPSAH weakly correlated with CA decision (V = 0.50). Mean sensitivity and specificity were 58% (95%CI: 44%, 71%) and 83 % (95%CI: 72 %, 94%), respectively. CONCLUSION: NAPSAH remains a diagnosis of exclusion. The NCCT diagnosis was moderately reliable and its impact on clinical decisions modest.

Patient Safety in Canadian Epilepsy Monitoring Units: A Survey of Current Practices.

BACKGROUND: Guidelines on epilepsy monitoring unit (EMU) standards have been recently published. We aimed to survey Canadian EMUs to describe the landscape of safety practices and compare these to the recommendations from the new guidelines. METHODS: A 34-item survey was created by compiling questions on EMU structure, patient monitoring, equipment, personnel, standardized protocol use, and use of injury prevention tools. The questionnaire was distributed online to 24 Canadian hospital centers performing video-EEG monitoring (VEM) in EMUs. Responses were tabulated and descriptively summarized. RESULTS: In total, 26 EMUs responded (100% response rate), 50% of which were adult EMUs. EMUs were on average active for 23.4 years and had on average 3.6 beds. About 81% of respondents reported having a dedicated area for VEM, and 65% reported having designated EMU beds. Although a video monitoring station was available in 96% of EMUs, only 48% of EMUs provided continuous observation of patients (video and/or physical). A total of 65% of EMUs employed continuous heart monitoring. The technologist-to-patient ratio was 1:1-2 in 52% of EMUs during the day. No technologist supervision was most often reported in the evening and at night. Nurse-to-EMU-patient ratio was mostly 1:1-4 independent of the time of day. Consent forms were required before admission in 27% of EMUs. CONCLUSION: Canadian EMUs performed decently in terms of there being dedicated space for VEM, continuous heart monitoring, and adequate nurse-to-patient ratios. Other practices were quite variable, and adjustments should be made on a case-by-case basis to adhere to the latest guidelines.

The performance of bibliometric analyses in the health sciences.

A bibliometric analysis (BA) is a knowledge synthesis methodology aimed at quantitively summarizing large amounts of bibliometric data. We aimed to summarize the performance of BAs in the health sciences. We searched Scopus for BAs in the health sciences published prior to May 10, 2023. All identified studies were included. We performed a BA on these studies in two steps: performance analysis and science mapping. For the performance analysis, various indicators of scientific production were calculated using the bibliometrix R package. For the science mapping, VOSviewer was used to generate a co-authorship network and a keyword co-occurrence network. In total, 5,828 BAs were analyzed. Scientific production has exploded in the last years, with more than 1,500 BAs published in 2022 alone. Scientific impact (i.e. citations) has also been rising, although at a lesser pace. The mean number of citations per year per BA was 1.78. China was the most productive country, publishing more BAs than the nine other most productive countries combined. China paradoxically had a lower number of citations per publication compared with the nine other most productive countries. International collaborations were rare. Common BA themes included oncology, public health, neurosciences, mental health, artificial intelligence, and COVID-19. BAs are increasingly common in the health sciences, but their performance remains limited. More international collaborations and standardized guidelines could help improve their performance, notably the frequency at which they are cited.

Localizing and lateralizing value of auditory phenomena in seizures.

BACKGROUND: Auditory seizures (AS) are a rare type of focal seizures. AS are classically thought to involve a seizure onset zone (SOZ) in the temporal lobe, but there remain uncertainties about their localizing and lateralizing value. We conducted a narrative literature review with the aim of providing an up-to-date description of the lateralizing and localizing value of AS. METHODS: The databases PubMed, Scopus, and Google Scholar were searched for literature on AS in December 2022. All cortical stimulation studies, case reports, and case series were analyzed to assess for auditory phenomena that were suggestive of AS and to evaluate if the lateralization and/or localization of the SOZ could be determined. We classified AS according to their semiology (e.g., simple hallucination versus complex hallucination) and the level of evidence with which the SOZ could be predicted. RESULTS: A total of 174 cases comprising 200 AS were analyzed from 70 articles. Across all studies, the SOZ of AS were more often in the left (62%) than in the right (38%) hemisphere. AS heard bilaterally followed this trend. Unilaterally heard AS were more often due to a SOZ in the contralateral hemisphere (74%), although they could also be ipsilateral (26%). The SOZ for AS was not limited to the auditory cortex, nor to the temporal lobe. The areas more frequently involved in the temporal lobe were the superior temporal gyrus (STG) and mesiotemporal structures. Extratemporal locations included parietal, frontal, insular, and rarely occipital structures. CONCLUSION: Our review highlighted the complexity of AS and their importance in the identification of the SOZ. Due to the limited data and heterogeneous presentation of AS in the literature, the patterns associated with different AS semiologies warrant further research.

Sensitivity and specificity of alternative screening methods for systematic reviews using text mining tools.

OBJECTIVES: To evaluate the impact of text mining (TM) on the sensitivity and specificity of title and abstract screening strategies for systematic reviews (SRs). STUDY DESIGN AND SETTING: Twenty reviewers each evaluated a 500-citation set. We compared five screening methods: conventional double screen (CDS), single screen, double screen with TM, combined double screen and single screen with TM, and single screen with TM. Rayyan, Abstrackr, and SWIFT-Review were used for each TM method. The results of a published SR were used as the reference standard. RESULTS: The mean sensitivity and specificity achieved by CDS were 97.0% (95% confidence interval [CI]: 94.7, 99.3) and 95.0% (95% CI: 93.0, 97.1). When compared with single screen, CDS provided a greater sensitivity without a decrease in specificity. Rayyan, Abstrackr, and SWIFT-Review identified all relevant studies. Specificity was often higher for TM-assisted methods than that for CDS, although with mean differences of only one-to-two percentage points. For every 500 citations not requiring manual screening, 216 minutes (95% CI: 169, 264) could be saved. CONCLUSION: TM-assisted screening methods resulted in similar sensitivity and modestly improved specificity as compared to CDS. The time saved with TM makes this a promising new tool for SR.

Sudden unexpected death in epilepsy (SUDEP): A bibliometric analysis.

OBJECTIVE: The literature on sudden unexpected death in epilepsy (SUDEP) has been evolving at a staggering rate. We conducted a bibliometric analysis of the SUDEP literature with the aim of presenting its structure, performance, and trends. METHODS: The Scopus database was searched in April 2023 for documents explicitly detailing SUDEP in their title, abstract, or keywords. After the removal of duplicate documents, bibliometric analysis was performed using the R package bibliometrix and the program VOSviewer. Performance metrics were computed to describe the literature's annual productivity, most relevant authors and countries, and most important publications. Science mapping was performed to visualize the relationships between research constituents by constructing a country collaboration network, co-authorship network, keyword co-occurrence network, and document co-citation network. RESULTS: A total of 2140 documents were analyzed. These documents were published from 1989 onward, with an average number of citations per document of 25.78. Annual productivity had been on the rise since 2006. Out of 6502 authors, five authors were in both the list of the ten most productive and the list of the ten most cited authors: Devinsky O, Sander JW, Tomson T, Ryvlin P, and Lhatoo SD. The USA and the United Kingdom were the most productive and cited countries. Collaborations between American authors and European authors were particularly rich. Prominent themes in the literature included those related to pathophysiology (e.g., cardiac arrhythmia, apnea, autonomic dysfunction), epilepsy characteristics (e.g., epilepsy type, refractoriness, antiseizure medications), and epidemiology (e.g., incidence, age, sex). Emerging themes included sleep, genetics, epilepsy refractoriness, and non-human studies. SIGNIFICANCE: The body of literature on SUDEP is rich, fast-growing, and benefiting from frequent international collaborations. Some research themes such as sleep, genetics, and animal studies have become more prevalent over recent years.

Use of non-medical cannabis in epilepsy: A scoping review.

Objective: The use of medical cannabis among people with epilepsy (PWE) has been garnering increasing interest. In this scoping review, we aimed to summarize the literature on recreational/non-medical cannabis (NMC) use in PWE, focusing on the experience, habits, and beliefs of PWE regarding NMC. Methods: Four databases (OVID Medline, OVID Embase, Ovid APA PsycInfo, and Web of Science) were searched for studies describing NMC use in PWE. NMC was defined as cannabis products procured from sources other than by prescription. Studies that consisted in original research and that detailed the experience, habits, and/or beliefs of PWE regarding NMC use were included in the analysis. Data pertaining to study identification, demographics, NMC use, and epilepsy characteristics were extracted. Descriptive statistical analyses and reflexive thematic analyses were performed to map these data. Results: In total, 3,228 records were screened, and 66 were included for analysis: 45 had mainly adult samples, whereas 21 had mainly pediatric samples. Most studies were published after 2010, originated from the USA, and were cross-sectional. The median number of PWE using cannabis in these studies was 24.5 (1-37,945). No studies showcased elderly PWE, and most had predominantly Caucasian samples. The lifetime prevalence of NMC use in PWE was variable, ranging between 0.69 and 76.8%. Factors frequently associated with NMC use in PWE were male sex, younger adult age, and lower education status. Children with epilepsy took NMC primarily for seizure control, using high CBD/THC ratios, and only orally. Adults with epilepsy took NMC for various reasons including recreationally, using variable CBD/THC ratios, and predominantly through smoking. The majority of PWE across all studies perceived that NMC aided in seizure control. Other aspects pertaining to NMC use in PWE were rarely reported and often conflicting. Conclusion: The literature on NMC use in PWE is sparse and heterogeneous, with many salient knowledge gaps. Further research is necessary to better understanding the experience, habits, and beliefs of PWE pertaining to NMC.

Epilepsy and cerebral developmental venous anomalies (DVAs): A systematic review.

OBJECTIVE: Cerebral developmental venous anomalies (DVAs) are frequent and rarely symptomatic. When symptomatic, DVAs may present with seizures; however, little is known about the characteristics of DVA-related epilepsy. In this systematic review, we aim to describe the clinical and paraclinical features of patients with DVA-related epilepsy. METHODS: This review was registered on PROSPERO (CRD42021218711). We searched the MEDLINE/PubMed and Scopus databases for case reports/series on patients with DVAs complicated by seizures. Studies describing patients with a potentially epileptogenic comorbid lesion close to their seizure focus were excluded. Descriptive statistical analyses were performed to synthetize patient characteristics. The methodological quality of each study was evaluated using a standardized appraisal tool. RESULTS: In total, 66 patients were included from 39 articles. The frontal lobe was the most common location for DVAs. The superior sagittal sinus drained half of the DVAs. Seizures were inaugural in most cases, and the most common manifestations accompanying seizures were headaches. EEG was abnormal in 93% of cases, but only 26% had characteristic epileptic spikes. More than half the patients suffered a medical complication due to their DVA, with hemorrhage and thrombosis being the most common. Refractory seizures were encountered in 19% of individuals. At 12 months of follow-up, 75% of patients were seizure free. Most included studies were at low risk of bias. SIGNIFICANCE: Epilepsy can be a complication of DVAs; these DVAs are mostly frontal or parietal, draining via the superior sagittal sinus or the vein of Galen.

Usage of Genetic Panels in an Adult Epilepsy Clinic.

BACKGROUND: There is limited data on the utility, yield, and cost efficiency of genetic testing in adults with epilepsy. We aimed to describe the yield and utility of genetic panels in our adult epilepsy clinic. METHODS: We performed a retrospective, cross-sectional study of all patients followed by an epileptologist at a Canadian tertiary care centre's epilepsy clinic between January 2016 and August 2021 for whom a genetic panel was ordered. A panel was generally ordered when the etiology was unknown or in the presence of a malformation of cortical development. We determined the yield of panel positivity and of confirmed genetic diagnoses. We also estimated the proportion of these diagnoses that were clinically actionable. RESULTS: In total, 164 panels were ordered in 164 patients. Most had refractory epilepsy (80%), and few had comorbid intellectual disability (10%) or a positive family history of epilepsy (11%). The yield of panel positivity was 11%. Panel results were uncertain 49% of the time and negative 40% of the time. Genetic diagnoses were confirmed in 7 (4.3%) patients. These genetic conditions involved the following genes: SCARB2, DEPDC5, PCDH19, LGI1, SCN1A, MT-TL1, and CHRNA7. Of the seven genetic diagnoses, 5 (71%) were evaluated to be clinically actionable. CONCLUSION: We report a lower diagnostic yield for genetic panels in adults with epilepsy than what has so far been reported. Although the field of the genetics of epilepsy is a fast-moving one and more data is required, our findings suggest that guidelines for genetic testing in adults are warranted.

Prevalence of Bipolar Symptoms or Disorder in Epilepsy: A Systematic Review and Meta-analysis.

BACKGROUND AND OBJECTIVES: This systematic review with meta-analysis (PROSPERO: CRD42021249336) was performed to estimate the pooled lifetime prevalence of bipolar symptoms (BS) and bipolar disorder (BD) in people with epilepsy (PWE). METHODS: A search was performed on June 5, 2021, in 4 databases (MEDLINE/PubMed, Ovid EMBASE, Ovid APA PsycInfo, and Web of Science) for original research reporting on BS/BD in PWE, with no restriction on language or time of publication. Inclusion criteria were as follows: (1) original research, (2) cross-sectional study design component, (3) reported lifetime prevalence of BS/BD or enough information to calculate an estimate, and (4) reported the method by which participants were deemed bipolar. Studies based on an exclusively pediatric population were excluded. To calculate pooled lifetime prevalence of BS/BD, 2 meta-analytic random-effects models were fitted, one for BS and the other for BD. Risk of bias was assessed using a standardized appraisal tool for studies reporting prevalence. Certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. RESULTS: A total of 750 records were screened and 17 studies were included for analysis: 7 provided prevalence estimates for only BS, 8 for only BD, and 2 for both BS and BD. After outlier exclusion and subgroup analysis using screening method as a moderator, the pooled prevalence of BS in PWE was 12.3% (95% CI 10.6%-14.1%) (7,506 PWE). The pooled prevalence of BD in PWE was 4.5% (95% CI 2.2%-7.4%) (48,334 PWE). Considerable heterogeneity was present, more so for BD than for BS, and could be explained through differences in population demographics and study methodology. DISCUSSION: This study's main limitation was regarding the certainty of evidence. However, our estimates of prevalence should prompt further research on BS/BD in PWE. Given the significant morbidity associated with BD, clinicians should carefully screen PWE for BS.

Insular Involvement in Cases of Epilepsy Surgery Failure.

BACKGROUND: Epilepsy surgery failure is not uncommon, with several explanations having been proposed. In this series, we detail cases of epilepsy surgery failure subsequently attributed to insular involvement. METHODS: We retrospectively identified patients investigated at the epilepsy monitoring units of two Canadian tertiary care centers (2004-2020). Included patients were adults who had undergone epilepsy surgeries with recurrence of seizures post-operatively and who were subsequently determined to have an insular epileptogenic focus. Clinical, electrophysiological, neuroimaging, and surgical data were synthesized. RESULTS: We present 14 patients who demonstrated insular epileptic activity post-surgery-failure as detected by intracranial EEG, MEG, or seizure improvement after insular resection. Seven patients had manifestations evoking possible insular involvement prior to their first surgery. Most patients (8/14) had initial surgeries targeting the temporal lobe. Seizure recurrence ranged from the immediate post-operative period to one year. The main modality used to determine insular involvement was MEG (8/14). Nine patients underwent re-operations that included insular resection; seven achieved a favorable post-operative outcome (Engel I or II). CONCLUSIONS: Our series suggests that lowering the threshold for suspecting insular epilepsy may be necessary to improve epilepsy surgery outcomes. Detecting insular epilepsy post-surgery-failure may allow for re-operations which may lead to good outcomes.

Epilepsy and Pregnancy: An Audit of Specialized Care.

BACKGROUND: Caring for women with epilepsy (WWE) during pregnancy poses unique challenges. We conducted an audit of the care our epilepsy clinic provided to pregnant WWE. METHODS: We performed a retrospective study on all pregnancies followed by an epileptologist at a Canadian tertiary care centre's epilepsy clinic between January 2003 and March 2021. Among 81 pregnancies in 53 patients, 72 pregnancies in 50 patients were analyzed to determine patient-related, follow-up-related, antiseizure-medication-related, and child-related pregnancy characteristics. Univariate analyses were performed to explore if these characteristics were associated with disabling seizure occurrence during pregnancy. RESULTS: Most pregnancies were intended (72%) and occurred in women who used folic acid pre-pregnancy (76%) and who followed recommended blood tests for antiseizure medication (ASM) levels (71%). In 49% of pregnancies, ASM dosage was modified; 53% of these modifications were made in response to ASM blood levels. Most often used ASMs were lamotrigine (43%), followed by carbamazepine (32%) and levetiracetam (13%). One child was born with a thyroglossal duct cyst; our congenital malformation rate was thus 2%. Disabling seizures occurred in 24% of pregnancies. Exploratory analyses suggested that disabling seizure occurrence during pregnancy was associated with younger patient age (p = 0.018), higher number of ASMs used during pregnancy (p = 0.048), lamotrigine usage in polytherapy (p = 0.008), and disabling seizure occurrence pre-pregnancy (p = 0.027). CONCLUSION: This Canadian audit provides an in-depth description of pregnancies benefiting from specialized epilepsy care. Our results suggest an association between disabling seizure occurrence during pregnancy and lamotrigine usage in polytherapy that warrants further evaluation.

Intervention Time and Adverse Events in a Canadian Epilepsy Monitoring Unit.

BACKGROUND: Intervention time (IT) in response to seizures and adverse events (AEs) have emerged as key elements in epilepsy monitoring unit (EMU) management. We performed an audit of our EMU, focusing on IT and AEs. METHODS: We performed a retrospective study on all clinical seizures of admissions over a 1-year period at our Canadian academic tertiary care center's EMU. This EMU was divided in two subunits: a daytime three-bed epilepsy department subunit (EDU) supervised by EEG technicians and a three-bed neurology ward subunit (NWU) equipped with video-EEG where patients were transferred to for nights and weekends, under nursing supervision. Among 124 admissions, 58 were analyzed. A total of 1293 seizures were reviewed to determine intervention occurrence, IT, and AE occurrence. Seizures occurring when the staff was present at bedside at seizure onset were analyzed separately. RESULTS: Median IT was 21.0 (11.0-40.8) s. The EDU, bilateral tonic-clonic seizures (BTCS), and the presence of a warning signal were associated with increased odds of an intervention taking place. The NWU, BTCS, and seizure rank (seizures were chronologically ordered by the patient for each subunit) were associated with longer ITs. Bedside staff presence rate was higher in the EDU than in the NWU (p < 0.001). AEs occurred in 19% of admissions, with no difference between subunits. AEs were more frequent in BTCS than in other seizure types (p = 0.001). CONCLUSION: This study suggests that close monitoring by trained staff members dedicated to EMU patients is key to optimize safety. AE rate was high, warranting corrective measures.

Wettability effect on wave propagation in saturated porous medium.

Micro-fluid mechanics studies have revealed that fluid slip on the boundary of a flow channel is a quite common phenomenon. In the context of a fluid-saturated porous medium, this implies that the fluid slippage increases with the increase of the hydrophobicity, which is the non-wetting degree. Previous studies find that wettability of the pore surface is strongly related to the slippage, which is characterized by slip length. To accurately predict acoustical properties of a fluid-saturated porous medium for different wettability conditions, the slippage of the wave-induced flow has to be taken into account. This paper introduces the slip length as a proxy for wettability into the calculation of the viscous correction factor, dynamic permeability, and dynamic tortuosity of the Biot theory for elastic waves in a porous medium. It demonstrates that, under different wettability conditions, elastic waves in a saturated porous medium have different phase velocity and attenuation. Specifically, it finds that increasing hydrophobicity yields a higher phase velocity and attenuation peak in a high-frequency range.

Long-term oncologic outcomes of laparoscopic versus open surgery for rectal cancer: a pooled analysis of 3 randomized controlled trials.

OBJECTIVE: To compare long-term oncologic outcomes between laparoscopic and open surgery for rectal cancer and to identify independent predictors of survival. BACKGROUND: Few randomized trials comparing laparoscopic and open surgery for rectal cancer have reported long-term survival data. METHODS: Data from the 3 randomized controlled trials comparing curative laparoscopic (n=136) and open surgery (n=142) for upper, mid, and low rectal cancer conducted at the Prince of Wales Hospital, Hong Kong, between September 1993 and August 2007 were pooled together for this analysis. Survival and disease status were updated to February 2012. Survival was calculated using the Kaplan-Meier method, and independent predictors of survival were determined using the Cox regression analysis. RESULTS: The demographic data of the 2 groups were comparable. The median follow-up time of living patients was 124.5 months in the laparoscopic group and 136.6 months in the open group. At 10 years, there were no significant differences in locoregional recurrence (5.5% vs. 9.3%; P=0.296), cancer-specific survival (82.5% vs. 77.6%; P=0.443), and overall survival (63.0% vs. 61.1%; P=0.505) between the laparoscopic and open groups. There was a trend toward lower recurrence rate at 10 years in the laparoscopic group than in the open group among patients with stage III cancer (P=0.078). The Cox regression analysis showed that stage III cancer, lymphovascular permeation, and blood transfusion, but not the operative approach, were independent predictors of poorer cancer-specific survival. CONCLUSIONS: This pooled analysis with a follow-up of more than 10 years confirms the long-term oncologic safety of laparoscopic surgery for rectal cancer.