Feasibility of Subxiphoid Anatomic Pulmonary Lobectomy in a Canine Model

Purpose. Transthoracic thoracoscopic approach is the gold standard in surgical treatment for thoracic disease. However, it is associated with significant chronic postoperative wound discomfort. Currently, limited data are available regarding the subxiphoid approach to the thoracic cavity. The present study is aimed to evaluate the performance of a subxiphoid anatomic pulmonary lobectomy (SAPL) in a canine model. Methods. The SAPL procedure was performed in 10 beagle dogs using a 3-cm incision over the xiphoid process. After thoracic exploration, SAPL was performed under flexible bronchoscopy guidance. The pulmonary vessel was divided with Ligasure and secured with a suture ligature. The bronchus was divided with endostapler. Surgical outcomes were evaluated by the success of SAPL and operative complications. Results. SAPL was successfully completed in 9 animals. One animal required conventional thoracotomy to resuture the pulmonary artery stump. Another animal encountered small middle lobe laceration after SAPL and died at 8 days postoperation due to respiratory distress. Conclusion. Subxiphoid anatomic pulmonary lobectomy is technically feasible. Refinement of endoscopic instruments combined with more research evidences may facilitate the development of subxiphoid platform in thoracic surgery.

Development of a novel depth of interaction PET detector using highly multiplexed G-APD cross-strip encoding

PURPOSE

The aim of this study was to develop a prototype PET detector module for a combined small animal positron emission tomography and magnetic resonance imaging (PET/MRI) system. The most important factor for small animal imaging applications is the detection sensitivity of the PET camera, which can be optimized by utilizing longer scintillation crystals. At the same time, small animal PET systems must yield a high spatial resolution. The measured object is very close to the PET detector because the bore diameter of a high field animal MR scanner is limited. When used in combination with long scintillation crystals, these small-bore PET systems generate parallax errors that ultimately lead to a decreased spatial resolution. Thus, we developed a depth of interaction (DoI) encoding PET detector module that has a uniform spatial resolution across the whole field of view (FOV), high detection sensitivity, compactness, and insensitivity to magnetic fields.

METHODS

The approach was based on Geiger mode avalanche photodiode (G-APD) detectors with cross-strip encoding. The number of readout channels was reduced by a factor of 36 for the chosen block elements. Two 12 × 2 G-APD strip arrays (25 μm cells) were placed perpendicular on each face of a 12 × 12 lutetium oxyorthosilicate crystal block with a crystal size of 1.55 × 1.55 × 20 mm. The strip arrays were multiplexed into two channels and used to calculate the x, y coordinates for each array and the deposited energy. The DoI was measured in step sizes of 1.8 mm by a collimated (18)F source. The coincident resolved time (CRT) was analyzed at all DoI positions by acquiring the waveform for each event and applying a digital leading edge discriminator.

RESULTS

All 144 crystals were well resolved in the crystal flood map. The average full width half maximum (FWHM) energy resolution of the detector was 12.8% ± 1.5% with a FWHM CRT of 1.14 ± 0.02 ns. The average FWHM DoI resolution over 12 crystals was 2.90 ± 0.15 mm.

CONCLUSIONS

The novel DoI PET detector, which is based on strip G-APD arrays, yielded a DoI resolution of 2.9 mm and excellent timing and energy resolution. Its high multiplexing factor reduces the number of electronic channels. Thus, this cross-strip approach enables low-cost, high-performance PET detectors for dedicated small animal PET and PET/MRI and potentially clinical PET/MRI systems.

Functional role of induced gamma oscillatory responses in processing noxious and innocuous sensory events in humans

Gamma time-frequency responses (TFRs) induced by painful laser in the contralateral primary somatosensory (SI) cortex have been shown to correlate with perceived pain-intensity in human. Given the functional roles of gamma TFRs in the cortical spaces, it remains unclear whether such a relationship is sustained for other brain regions where the laser-evoked potentials (LEPs) are presented. In this study, we delivered the painful laser pluses at random pain-intensity levels (i.e. strong, medium and weak) in a single train to the dorsal hand of six patients with uncontrolled epilepsy. The laser stimulus produced a painful pinprick sensation by activating nociceptors located in the superficial layers of the skin. For each patient, arrays of >64 subdural electrodes were implanted directly covering the contralateral SI, parasylvian (PS) and medial frontal (MF) cortices to study the stimulus related gamma (TFRs) in the neocortex. In addition, using the same stimulation paradigm, the modality specificity of gamma TFRs was further examined by applying innocuous vibrotactile stimuli to the same regions of the dorsal hand in a separated group of five patients. Our results showed that gamma TFRs are not modality specific, but the largest gamma TFRs were consistently found within the SI region and noxious laser elicited significantly stronger gamma TFRs than innocuous nonpainful vibratory stimuli. Furthermore, stronger pain induced stronger gamma TFRs in the cortices of SI (r=0.4, p<0.001) and PS (r=0.29, p=0.005). Given that potentially harmful noxious stimulus would automatically capture greater attention than the innocuous ones, our results support the hypothesis that the degree of SI and PS gamma TFRs is associated with an attentional drive provoked by painful stimuli.

Comparison of 19-gauge eXcelon and WANG MW-319 transbronchial aspiration needles

Conventional transbronchial needle aspiration (TBNA) using 19‐gauge needles can obtain larger histological specimens for hilar‐mediastinal diagnosis. A new 19‐gauge eXcelon needle was introduced in Taiwan in July 2012. We prospectively enrolled patients with hilar‐mediastinal lesions and pathology results of suspected benign origin or lymphoproliferative processes, to perform TBNA using a 19‐gauge eXcelon needle, between July 2012 and December 2012. The results were compared with historical control of TBNA using a WANG MW‐319 needle between January 2011 and June 2012. The procedure was performed by the same pulmonologist, and rapid on‐site cytologic evaluation was used. The 19‐gauge eXcelon needle was used in nine patients with 15 lymph nodes aspirated, with a mean diameter of 23.3 ± 10.7 mm. The mean number of needle passes was 2.7 ± 1.4, with a diagnostic accuracy of 77.8%. The MW‐319 needle was used in 12 patients with 18 lymph nodes aspirated, with a mean diameter of 21.3 ± 5.7 mm. The mean number of needle passes was 2.2 ± 0.4, with a diagnostic accuracy of 75.0%. Neither technical nor major clinical complications were noted in either group. We concluded that the 19‐gauge eXcelon needle was as safe and effective as the MW‐319 needle. A more adequate specimen could be obtained and fewer needle passes were required with the MW‐319 needle, although the difference did not reach significance.

Comparison of pathologic stage in patients receiving esophagectomy with and without preoperative chemoradiation therapy for esophageal SCC

The prognostic value for the post-chemoradiation therapy (CRT) pathologic stage is uncertain. The purpose of this study was to compare the pathologic stage in patients undergoing esophagectomy with and without preoperative CRT for esophageal squamous cell carcinoma (ESCC). This study retrospectively reviewed the data from 2151 patients with ESCC who underwent esophagectomy with or without preoperative CRT between 2008 and 2011 in Taiwan. Patients were divided into 2 groups. Group A consisted of patients treated with primary surgery without prior treatments (n=1301), and group B consisted of patients receiving preoperative CRT followed by esophagectomy (n=850). In group A, 679 patients received surgery alone, 92 received postoperative chemotherapy, 416 received postoperative chemoradiation therapy, and 114 received postoperative radiation therapy. In group A, the 3-year survival rates by pathologic stage were 82.2% for stage 0, 67.6% for stage I, 50.7% for stage II, 21.5% for stage III, and 14.8% for stage IV (P<.001). In group B, the 3-year survival rates of post-CRT pathologic stages 0, I, II, III, and IV were 59.4%, 46.0%, 40.3%, 19.1%, and 8.2%, respectively (P<.001). In multivariate analysis, the pathologic T, N, and M were all independent prognostic factors in both group A (esophagectomy alone) and B (CRT plus esophagectomy). The current, 7th edition of the esophageal TNM staging system could adequately stratify prognostic groups in patients with squamous cell carcinoma who were treated with preoperative CRT and esophagectomy.

The interaction of serum testosterone levels and androgen receptor CAG repeat polymorphism on the risk of erectile dysfunction in aging Taiwanese men

Testosterone has been found to play important roles in men's sexual function. However, the effects of testosterone can be modulated by androgen receptor (AR) CAG repeat polymorphism. It could also contribute to the risk of erectile dysfunction (ED). The aim of this study is to evaluate the interaction of serum testosterone levels and AR CAG repeat polymorphism on the risk of ED in aging Taiwanese men. This cross-sectional data of Taiwanese men older than 40 years were collected from a free health screening held between August 2010 and August 2011 in Kaohsiung city, Taiwan. All participants completed a health questionnaires included five-item version of the International Index of Erectile Function (IIEF-5) and the International Prostate Symptoms Score, received a detailed physical examination and provided 20 cm3 whole blood samples for biochemical and genetic evaluation. The IIEF-5 was used to evaluate ED. Serum albumin, total testosterone (TT), and sex hormone-binding globulin levels were measured. Free testosterone level was calculated. AR gene CAG repeat polymorphism was determined by direct sequencing. Finally, 478 men with the mean age of 55.7 ± 4.8 years were included. When TT levels were above 330 ng/dL, the effect of testosterone level on erectile function seemed to reach a plateau and a significantly negative correlation between AR CAG repeat length and the score of IIEF-5 was found (r = -0.119, p = 0.034). After adjusting for other covariates, the longer AR CAG repeat length was still an independent risk factor for ED in subjects with TT above 330 ng/dL (p = 0.006), but not in TT of 330 ng/dL or below. In conclusion, both serum testosterone levels and AR CAG repeat polymorphism can influence erectile function concomitantly. In subjects with normal TT concentration, those with longer AR CAG repeat lengths have a higher risk of developing ED.

Cross-frequency coupling in deep brain structures upon processing the painful sensory inputs

Cross-frequency coupling has been shown to be functionally significant in cortical information processing, potentially serving as a mechanism for integrating functionally relevant regions in the brain. In this study, we evaluate the hypothesis that pain-related gamma oscillatory responses are coupled with low-frequency oscillations in the frontal lobe, amygdala and hippocampus, areas known to have roles in pain processing. We delivered painful laser pulses to random locations on the dorsal hand of five patients with uncontrolled epilepsy requiring depth electrode implantation for seizure monitoring. Two blocks of 40 laser stimulations were delivered to each subject and the pain-intensity was controlled at five in a 0-10 scale by adjusting the energy level of the laser pulses. Local-field-potentials (LFPs) were recorded through bilaterally implanted depth electrode contacts to study the oscillatory responses upon processing the painful laser stimulations. Our results show that painful laser stimulations enhanced low-gamma (LH, 40-70 Hz) and high-gamma (HG, 70-110 Hz) oscillatory responses in the amygdala and hippocampal regions on the right hemisphere and these gamma responses were significantly coupled with the phases of theta (4-7 Hz) and alpha (8-1 2 Hz) rhythms during pain processing. Given the roles of these deep brain structures in emotion, these findings suggest that the oscillatory responses in these regions may play a role in integrating the affective component of pain, which may contribute to our understanding of the mechanisms underlying the affective information processing in humans.

Inhibition of adipogenic differentiation of bone marrow mesenchymal stem cells by erythropoietin via activating ERK and P38 MAPK

We examined whether erythropoietin (EPO) can inhibit adipogenic differentiation of mesenchymal stem cells (MSCs) in the mouse bone marrow and its underlying mechanism. We separated and extracted mouse bone marrow MSCs and induced adipogenic differen-tiation using 3-isobutyl-1-methylxanthine, insulin, and dexamethasone. Different concentrations of EPO were added to the cells and observed by Oil Red O staining on the 20th day to quantitatively analyze the degree of cell differentiation. mRNA expression levels of peroxysome proliferator-activated receptor γ (PPARγ), CCAAT enhancer binding protein α, and adiponectin were analyzed by real-time quantitative polymerase chain reaction, and the activity of PPARγ, extracellular sig-nal-regulated kinase (ERK), and p38 mitogen-activated protein kinase (p38 MAPK) were determined by western blotting. EPO significantly inhibited adipogenic differentiation of MSCs after 20 days and reduced absorbance values by Oil Red O staining without affecting proliferation activity. EPO downregulated the mRNA expression of PPARγ, CCAAT enhancer binding protein α, fatty acid binding protein 4, and adiponec-tin during adipogenesis and increased protein phosphorylation of ERK, p38 MAPK, and PPARγ during differentiation. EPO downregulated the mRNA expression of PPARγ, CCAAT enhancer binding protein α, fatty acid binding protein 4, and adiponectin by increasing protein phosphor-ylation of ERK, p38 MAPK, and PPARγ during differentiation, which inhibited adipogenic differentiation of MSCs.

The Prognostic Impact of Preoperative and Postoperative Chemoradiation in Clinical Stage II and III Esophageal Squamous Cell Carcinomas: A Population Based Study in Taiwan

While preoperative chemoradiation followed by surgery (pre-OP CRT) has been widely applied in the treatment of patients with esophageal cancer, some studies have shown a survival benefit of postoperative chemoradiation (post-OP CRT). The optimal combination of multimodality therapy and the sequence of surgery and chemoradiation for esophageal cancer remain to be investigated. A total of 1385 patients with clinical stage II and III esophageal squamous cell carcinoma (ESCC) were included. On the basis of the sequence of surgery and chemoradiation, the patients were grouped as follows: preoperative chemoradiation followed by surgery (pre-OP CRT+S), surgery alone (S), and surgery followed by postoperative chemoradiation (S+post-OP CRT). Propensity score matching analysis was used to identify 78 well-balanced patients in each group for outcome comparison.In all, 753, 339, and 293 patients were in the pre-OP CRT+S, S, and S+post-OP CRT groups, respectively. Before matching, no differences were observed in the overall survival among the patients in these 3 groups (P = 0.422). After matching, both the pre-OP CRT+S and S+post-OP CRT groups were significantly associated with a better survival compared with the S group (pre-OP CRT+S vs. S: P < 0.001; S+post-OP CRT vs. S: P = 0.005). In contrast, the survival was similar between the pre-OP CRT+S and S+post-OP CRT groups (P = 0.544). In the subgroup analysis, patients with clinical T3/4 stage tumors or those with a tumor size greater than 5 cm were more likely to demonstrate an overall survival benefit from pre-OP CRT compared with post-OP CRT. Both pre-OP CRT and post-OP CRT demonstrated a survival benefit compared with surgery alone, which indicates the importance of trimodality therapy in patients with clinical stage II/III ESCC. However, no survival difference was observed among patients in the pre-OP CRT+S and S+post-OP CRT groups, which suggests that the sequence of surgery and chemoradiation may be irrelevant to the outcome.

Radical Lymph Node Dissection in Primary Esophagectomy for Esophageal Squamous Cell Carcinoma

BACKGROUND

Subtotal esophagectomy with radical lymph node dissection (RLND) remains an effective therapeutic strategy for localized esophageal squamous cell carcinoma (ESCC). However, controversy exists regarding the extent to which RLND should be performed. We reappraised the prognostic impact and accurate nodal staging of RLND in ESCC.

METHODS

The data from 101 ESCC patients (mean age, 57.5 years; 93 men) who underwent primary subtotal esophagectomy were retrospectively collected. Candidate variables, including the number of total dissected lymph nodes (TDLN [subgrouped into TDLN less than 13, TDLN 13 to 40, and TDLN more than 40]), were evaluated to determine their prognostic impacts and hazard ratio (HR).

RESULTS

Fewer TDLN (p < 0.001; HR 9.011, 2.449, and 1.000 for TDLN less than 13, TDLN 13 to 40, and TDLN more than 40, respectively), tumor length exceeding 3.5 cm (p < 0.001; HR 3.321), resection margin invasion (p < 0.001; HR 14.493), and positive nodal status (p = 0.002; HR 2.730) were independent predictors of a poor prognosis. Considering the 54 node-negative patients, more TDLN correlated with improved survival (p = 0.001). Risk analysis demonstrated that one fewer TDLN could contribute to an increased HR of 1.047 (p = 0.014). However, RLND involving more TDLN appeared to lose the prognostic impact for the 47 node-positive patients (p = 0.072). Furthermore, the number of positive dissected lymph nodes remained at approximately 4 if the number of TDLN exceeded 20.

CONCLUSIONS

For N-negative or N-positive ESCC patients undergoing primary surgical resection, the number of TDLN influenced their prognosis or nodal staging accuracy, respectively. At least 20 TDLN were necessary for N-positive patients.

Sexual genetic and simple sequence repeat (SSR) analysis for molecular marker development on the all hermaphrodite papaya

The papaya (Carica papaya L.) is one of the most important economic tropical fruits in the world, and the hermaphrodite is the preferred type in field cultures. We analyzed the sexual ratio of offspring from the cultivar 'Taiwan Seed Station No. 7' (T7) by a self-cross and its cross with Taichung Sunrise (TS). Female progeny from the T7 self-crossing were not observed. This finding may be caused by a lethal gene that is linked to females. In this study, we selected 192 simple sequence repeats (SSRs) to analyze the polymorphism between T7 and TS. A total of 37 SSRs were identified for T7 and TS. In addition, 14 SSRs served as the molecular makers for identification of T7, TS and their hybrid offsprings. Thus, the results show that the genetic similarity between T7 and TS is rather high. This suggests that T7 may be a mutant of TS. Phylogenetic analysis from the SSR polymorphisms of the above parent strains and 15 F1 offspring revealed the genetic distance of the F1 offspring located between T7 and TS. The results of this study may provide an opportunity for elucidating the genetic characteristics of all hermaphrodites via identification of molecular makers.

Multiinstitutional analysis of single-port video-assisted thoracoscopic anatomical resection for primary lung cancer

BACKGROUND

Multiinstitutional analysis of single-port video-assisted thoracic surgery (VATS) for anatomic pulmonary resection is rare. This study aimed to address the technical feasibility and applicability of single-port video-assisted anatomical resection for primary lung cancer.

METHODS

A total of 121 patients with primary lung cancer undergoing single-port video-assisted anatomical resection between 2011 and 2014 in 4 hospitals were included. The clinicopathologic variables and perioperative outcomes were collected and analyzed retrospectively.

RESULTS

Single-port VATS segmentectomies and lobectomies were performed in 24 (19.8%) and 97 (80.2%) patients, respectively. One hundred seven of 121 (88.4%) patients had adenocarcinoma and 93 of 121 (76.9%) had pathologic stage I lung cancer. The average operative time and estimated blood loss was 198.8 ± 65.4 minutes and 99.1 ± 147.6 mL, respectively. The conversion and complication rates were 2.5% (3 of 121 cases) and 14.0% (17 of 121 cases), respectively. There was no surgical mortality, and the average length of hospital stay was 6.6 ± 2.6 days. The mean resected lymph node was 22.6 ± 12.0. We also identified patient age of 60 years or more, male sex, and tumor size greater than 3 cm as unfavorable perioperative outcome predictors after single-port video-assisted anatomical pulmonary resection.

CONCLUSIONS

This first multiinstitutional single-port VATS study demonstrated that anatomical resection for primary lung cancer can be safely and effectively completed through a single-port VATS approach in hospitals experienced in VATS techniques.

Subxyphoid single-incision thoracoscopic pulmonary metastasectomy

Single-incision thoracoscopic surgery has increasingly attracted public interest and been applied in numerous thoracic procedures. However, single-incision thoracoscopic surgery is associated with requiring subsequent procedures, such as intercostal neuralgia. Herein, we extend the single-port technique of pulmonary metastasectomy through a single subxiphoid approach, and report the first two cases of this procedure to date.

Painful cutaneous laser stimuli induce event-related gamma-band activity in the lateral thalamus of humans

Although the thalamus is an important module in "pain networks," there are few studies of the effect of experimental pain upon thalamic oscillations. We have now examined the hypothesis that, during a series of painful cutaneous laser stimuli, thalamic signals will show stimulus-related gamma-band spectral activity, which is modulated by attention to vs. distraction from the painful stimulus. When the series of laser stimuli was presented, attention was focused by counting the laser stimuli (count laser task), while distraction was produced by counting backward (count back plus laser task). We have studied the effect of a cutaneous laser on thalamic local field potentials and EEG activity during awake procedures (deep brain stimulation implants) for the treatment of essential tremor. At different delays after the stimulus, three low gamma- (30-50 Hz) and two high gamma-band (70-90 Hz) activations were observed during the two tasks. Greater high-gamma activation was found during the count laser task for the earlier window, while greater high-gamma activation was found during the count back plus laser task for the later window. Thalamic signals were coherent with EEG signals in the beta band, which indicated significant synchrony. Thalamic cross-frequency coupling analysis indicated that the phase of the lower frequency activity (theta to beta) modulated the amplitude of the higher frequency activity (low and high gamma) more strongly during the count laser task than during the count back plus laser task. This modulation might result in multiplexed signals each encoding a different aspect of pain.

Second primary lung cancers among breast cancer patients treated with anti-estrogens have a longer cancer-specific survival

BACKGROUND/AIM

Estrogen is thought to play an important role in lung cancer carcinogenesis and progression. The incidence and survival of second primary lung cancer among breast cancer patients with and without anti-estrogen therapy were evaluated.

PATIENTS AND METHODS

All women diagnosed with breast cancer and treated at the Sun Yat-Sen Cancer Center between January 2000 and December 2009 were included and followed-up for occurrence and/or death from lung cancer until December 2011.

RESULTS

Twenty-six women developed second primary lung cancer among 6,361 breast cancer patients. All but one were adenocarcinoma and none had a smoking habit. Seventeen (65.4%) patients had previously received anti-estrogen treatment. The relative risk of developing second primary lung cancer among those who have received anti-estrogens for breast cancer and those who have not was 1.01 (95% confidence interval (CI)=0.45~2.28; p=0.970). Second primary lung cancer patients who have received anti-estrogens had a longer cancer-specific survival (p=0.007). The multivariate Cox proportional hazards analysis showed that anti-estrogen therapy remained an independent prognostic factor with a hazard ratio of 0.11 (95% CI=0.01~0.97, p=0.002) for second primary lung cancer patients.

CONCLUSION

The results of this study further support the fact that estrogen adversely affects the prognosis of patients with lung cancer. However, the role of estrogen in lung cancer carcinogenesis remains to be determined.

Hospital type- and volume-outcome relationships in esophageal cancer patients receiving non-surgical treatments

AIM: To study the “hospital type-outcome” and “volume-outcome” relationships in patients with esophageal cancer who receive non-surgical treatments.

METHODS: A total of 6106 patients with esophageal cancer diagnosed between 2008 and 2011 were identified from a national population-based cancer registry in Taiwan. The hospital types were defined as medical center and non-medical center. The threshold for high-volume hospitals was based on a median volume of 225 cases between 2008 and 2011 (annual volume, > 56 cases) or an upper quartile (> 75%) volume of 377 cases (annual volume > 94 cases). Cox regression analyses were used to determine the effects of hospital type and volume outcome on patient survival.

RESULTS: A total of 3955 non-surgically treated patients were included in the survival analysis. In the unadjusted analysis, the significant prognostic factors included cT, cN, cM stage, hospital type and hospital volume (annual volume, > 94 vs≤ 94). The 1- and 3-year overall survival rates in the non-medical centers (36.2% and 13.2%, respectively) were significantly higher than those in the medical centers (33.5% and 11.3%, respectively; P = 0.027). The 1- and 3-year overall survival rates in hospitals with an annual volume of ≤ 94 (35.3% and 12.6%, respectively) were significantly higher than those with an annual volume of > 94 (31.1% and 9.4%, respectively; P = 0.001). However, in the multivariate analysis, the hospital type was not statistically significant. Only cT, cN, and cM stages and hospital volume (annual volume > 94 vs≤ 94) were independent prognostic factors.

CONCLUSION: Whether the treatment occurs in medical centers is not a significant prognostic factor. High-volume hospitals were not associated with better survival rates compared with low-volume hospitals.

Precise and fast video assisted thoracoscopic bronchial sleeve resection

Surgical management for lung cancer is basically a destructive one. The lung parenchyma removed is in the balance between the purpose of curative resection and the preservation of patient's lung function. Bronchial sleeve has been alternatively developed to achieve the same purpose, but through a different way-to save back healthy lung tissue through reconstruction of the central airway. Sleeve resection had been done with open technique for years, and just like the other thoracic operations, has continuously evolved into the era of minimally invasive surgery in spite of its difficulty. With rapid advancement and availability in technology-high resolution 3-D dynamic chest computed tomography (CT), PET-CT, and endobronchial ultrasound (EBUS), these tools are very helpful for us to have more precise tumor staging, and suitable for preoperative surgical planning. Under magnified 3-D endoscopic view and modified endoscopic suturing method, re-anastomosis of the airway could be easier and quicker, which would facilitate this innovative operation to accumulate experience in the not too distant future.

Safety of interventional bronchoscopy through complication review at a cancer center

BACKGROUND AND AIMS

There have been rapid advances in the area of interventional bronchoscopy over the past 15 years, but associated complications have been rarely discussed. A longitudinal evaluation of the same operator's performance at a cancer center is reported.

METHODS

A detailed record review of diagnostic and therapeutic bronchoscopy between January 1997 and March 2013 was conducted.

RESULTS

Among the 1358 diagnostic bronchoscopies, there were nine major complications requiring premature termination and three pneumothoraces found during follow-up (0.88%). An escalation in the level of care was required for four patients with massive bleeding, asthma attack, sedation intoxication and myocardial ischemia, respectively. Six cases occurred after brushing (0.71%), and five cases before any sampling procedure was conducted. The complication rate was highest for peripheral lesions (1.03%). Among the 109 therapeutic bronchoscopies, no major patient-specific complication occurred except for excessive granulation tissue formation following metallic stenting in one patient with benign tracheal stenosis.

CONCLUSION

The complication rate with regard to bronchoscopy is comparable with historical controls according to the related literature, and their occurrence appears to be sporadic, not relevant to patient characteristics and mostly related to the bronchoscopy itself rather than the introduction of new techniques. Bronchoscopy remains safe along with technical innovations. However, risk recognition and effective prevention is essential.

Impact of hospital volume on long-term survival after resection for oesophageal cancer: a population-based study in Taiwan†

OBJECTIVES

Previous studies have shown that patients who undergo oesophageal cancer surgery in high-volume hospitals have lower postoperative mortality rates. However, the impact of hospital volume on long-term survival is controversial.

METHODS

We identified 2151 patients who were diagnosed with oesophageal cancer between 2008 and 2011 from a national population-based cancer registry in Taiwan. High-volume hospitals were defined as those performing more than 86 oesophagectomies during that period (22 cases/year). Patients were stratified by whether they received preoperative chemoradiation. Cox regression analyses were used to determine the survival impact of hospital volume.

RESULTS

The 3-year overall survival rates after oesophagectomies were 44.9% in high-volume hospitals, compared with 40.2% in low-volume hospitals (P = 0.002). For patients who received preoperative chemoradiation (n = 850), the 1- and 3-year overall survival rates were 74.7 and 36.8%, respectively, in high-volume hospitals, compared with 73.5 and 42.6%, respectively, in low-volume hospitals (P = 0.333). For patients who did not receive preoperative chemoradiation (n = 1301), the 1- and 3-year overall survival rates were 78.1 and 50.0%, respectively, in high-volume hospitals, compared with 67.9 and 38.8%, respectively, in low-volume hospitals (P < 0.001). Multivariate analysis showed that hospital volume, resection margin, cT, pT and pN stages are significant independent prognostic factors.

CONCLUSIONS

Overall survival rate of patients who undergo oesophagectomies without preoperative chemoradiation at high-volume hospitals is significantly higher than at low-volume hospitals. However, there was no significant correlation between hospital volume and long-term outcome in patients who received preoperative chemoradiation.

Isolation and mRNA expression of hypoxia-inducible factor α (HIF-α) in two sublittoral nassariid gastropods: Nassarius siquijorensis and Nassarius conoidalis

Hypoxia-inducible factor (HIF) is commonly found in vertebrates as an adaptation against hypoxia. In this study, partial sequences of HIF were first reported for subtidal nassariid gastropods, Nassarius siquijorensis and Nassarius conoidalis. The phylogenetic tree of HIF-α among various animal groups was inferred. Adults of both N. siquijorensis and N. conoidalis were exposed to 24 h and 1 week hypoxia (1.5 mg O2 l(-1)) and the change of HIF-α mRNA level was determined in gill, foot muscle and hepatopancreas by using quantitative real-time PCR. The expression profile of HIF-α was also investigated in veliger larvae after 1 and 24 h hypoxia exposure. The HIF-α mRNA from gills of N. siquijorensis was 2.22-fold elevated after 24 h of exposure but returned back to the baseline level after 1 week of exposure. In contrast to N. siquijorensis, both short-term and long-term exposure to hypoxia significantly enhanced the mRNA level of HIF-α in the gill of N. conoidalis. Both 24 h and 1 week of exposure resulted in a significantly higher degree of expression of mRNA of HIF-α in the foot muscle of N. siquijorensis and N. conoidalis. For hepatopancreas, the mRNA level of HIF-α remained unchanged in N. siquijorensis after both 24 h and 1 week of exposure to hypoxia but a significant enhancement was observed in N. conoidalis after 1 week of exposure to hypoxia. The mRNA level of HIF-α significantly reduced after 24 h of exposure to hypoxia in the larvae of N. siquijorensis. The different expression patterns of HIF-α mRNA between the two species reflected their different adaptation abilities to hypoxia, which will further explain the differences in the distribution of these species in Hong Kong waters with N. siquijorensis being predominant in regions suffered from summer hypoxia.

Single-port video-assisted thoracoscopic surgery for lung cancer

In 2004, novel results using pulmonary wedge resection executed through single-port video-assisted thoracoscopic surgery (VATS) was first described. Since that time, single-port VATS has been advocated for the treatment of a spectrum of thoracic diseases, especially lung cancer. Lung cancer remains one of the top three cancer-related deaths in Taiwan, and surgical resection remains the "gold standard" for early-stage lung cancer. Anatomical resections (including pneumonectomy, lobectomy, and segmentectomy) remain the primary types of lung cancer surgery, regardless of whether conventional open thoracotomy, or 4/3/2-ports VATS are used. In the past three years, several pioneers have reported their early experiences with single-port VATS lobectomy, segmentectomy, and pneumonectomy for lung cancer. Our goal was to appraise their findings and review the role of single-port VATS in the treatment of lung cancer. In addition, the current concept of mini-invasive surgery involves not only smaller resections (requiring only a few incisions), but also sub-lobar resection as segmentectomy. Therefore, our review will also address these issues.

Painful cutaneous laser stimuli induce event-related oscillatory EEG activities that are different from those induced by nonpainful electrical stimuli

The non-phase-locked EEG response to painful stimuli has usually been characterized as decreased oscillatory activity (event-related desynchronization, ERD) in the alpha band. Increased activity (event-related synchronization, ERS) in the gamma band has been reported more recently. We have now tested the hypothesis that the non-phase-locked responses to nonpainful electric cutaneous stimuli are different from those to painful cutaneous laser stimuli when the baseline salience of the two stimuli is the same and the salience during the protocol is modulated by count laser and count electric tasks. Both of these stimuli were presented in random order in a single train at intensities that produced the same baseline salience in the same somatic location. The response to the laser stimulus was characterized by five windows (designated windows I-V) in the time-frequency domain: early (200-400 ms) and late (600-1,400 ms) delta/theta ERS, 500-900 ms alpha ERD, 1,200-1,600 ms beta ERS (rebound), and 800-1,200 ms gamma ERS. Similar ERS/ERD windows of activity were found for the electric stimulus. Individual participants very commonly had activity in windows consistent with the overall analysis. Linear regression of ERS/ERD for parietal channels was most commonly found for sensory (pain or unpleasantness)- or attention (salience)-related measures. Overall, the main effect for modality was found in window I-delta/theta and window V-gamma, and the Modality with Task interaction was found in all five windows. All significant interaction terms included Modality as a factor. Therefore, Modality was the most common factor explaining our results, which is consistent with our hypothesis.

Comparisons of the metabolic responses of two subtidal nassariid gastropods to hypoxia and re-oxygenation

Changes in the levels of carbohydrate, lipid, protein and anaerobic metabolites (succinate, lactate, acetate, fumarate and propionate), upon exposure to hypoxia (1.5 mg O2 l(-1)) and after reoxygenation in subtidal gastropods Nassarius siquijorensis and N. conoidalis, were compared. A significant decrease of the glycogen content was observed under hypoxia in N. conoidalis but not in N. siquijorensis. A greater increase in the concentrations of anaerobic metabolites was observed in N. conoidalis under hypoxia, and their levels did not return to baseline after returning to normoxia for 24h. In contrast, a lower rate of accumulation of the metabolites was observed in N. siquijorensis, and complete recovery from anaerobic metabolism was observed after reoxygenation. The results lend further support to the role of hypoxia in governing the different distributional patterns between the two subtidal gastropods in Hong Kong waters.