Additional Wedge Research Articles

Risk factors for prolonged air leak after uniportal anatomical segmentectomy.

Our aim was to investigate the incidence and risk factors for prolonged air leak in patients undergoing minimally invasive single-port pulmonary segmentectomy. A retrospective analysis of all patients undergoing uniportal segmentectomy in our department from March 2015 to September 2023 was performed. Univariable, multivariable logistic regression analyses and machine learning were used to investigate risk factors for prolonged air leak (>5 days). 575 segmentectomies were performed using uniportal video-assisted thoracoscopic surgery. 333 patients (57.9%) were men and the mean age was 64.8 years.Prolonged air leak occurred in 88 patients (15.3%). Length of stay and duration of chest drainage were 8.6 (SD 4.86) and 10.6 (SD 8.12) days in the subgroup with prolonged air leak, compared to 3.6 (SD 2.25) and 2.0 (SD 1.3) days in the subgroup without air leak (p < 0.0001). Multivariable analysis revealed that upper lobe location, lower BMI, an additional wedge resection on another segment and hypertension were associated with increased risk of PAL.Machine learning was used to develop models that predicted the occurrence of prolonged air leak with an accuracy of 70%. The first model detected the following parameters as significant: resection of segment 2, diabetes, inhalers, and squamous cell carcinoma. The second model recognized DLCO (%), pack-years, FEV1 (%) and surgery time respectively. Low BMI, DLCO% or FEV1% values, increased pack-years, inhalers, diabetes, hypertension, histology of primary lung cancer, longer surgery time, an additional wedge resection, segment 2 removal and upper lobe surgery were identified as risk factors for prolonged air leak.

Intraoperative Molecular Imaging with Pafolacianine in Resection of Occult Pulmonary Malignancy in the ELUCIDATE trial

Clinical studies have demonstrated that intraoperative molecular imaging (IMI) with pafolacianine identifies occult pulmonary lesions that are not identified by preoperative CT or by intraoperative inspection techniques in ∼20% of patients. In this study we provide a description of occult lesion clinical data and evaluate characteristics so that surgeons can better incorporate this emerging technology into clinical decision making. Participants (n=100) enrolled in a Phase 3 trial of IMI with pafolacianine during pulmonary resection (ELUCIDATE, NCT04241315) were identified. Participants underwent preoperative computed tomography (CT)with 1.25mm slices. Variables and lesion characteristics were analyzed. Positive predictive value and false positive rates were tabulated for IMI fluorescent lesions with predictors of malignant versus benign occult lesions described. IMI identified 29 occult lesions in 23 (23%) participants. Seventeen of 29 (58%) lesions were identified within the same lobe as known lesions; 12 of 29 (42%) identified in a different lobe from the suspicious nodule known by preoperative assessment. Twenty-three of 29 (79%) of occult lesions found by IMI were resected with an additional wedge resection. Ten of 29 (34%) lesions identified by IMI were malignant. There was no additional morbidity in participants with lesions resected. With pafolacianine, 7 participants had a synchronous primary stage I lung cancer identified and one subject had additional metastases identified. . IMI with pafolacianine identifies occult malignant lesions during pulmonary resection despite thorough preoperative imaging and intraoperative assessment by experienced surgeons.

Technical note: Impact of beam properties for uveal melanoma proton therapy-An in silico planning study.

To evaluate the impact of beam quality in terms of distal fall-off (DFO, 90%-10%) and lateral penumbra (LP, 80%-20%) of single beam ocular proton therapy (OPT) and to derive resulting ideal requirements for future systems. Nine different beam models with DFO varying between 1 and 4mm and LP between 1 and 4mm were created. Beam models were incorporated into the RayStation with RayOcular treatment planning system version 10 B (RaySearch Laboratories, Stockholm, Sweden). Each beam model was applied for eight typical clinical cases, covering different sizes and locations of uveal melanoma. Plans with and without an additional wedge were created, resulting in 117 plans with a total prescribed median dose of 60Gy(RBE) to the clinical target volume. Treatment plans were analyzed in terms of V20-V80 penumbra volume, D1 (dose to 1% of the volume) for optic disc and macula, optic nerve V30 (volume receiving 30Gy(RBE), i.e., 50% of prescription), as well as average dose to lens and ciliary body. An LP-dependent aperture margin was based on estimated uncertainties, ranging from 1.7 to 4.0mm. V20-V80 showed a strong influence by LP, while DFO was less relevant. The optic disc D1 reached an extra dose of up to 3000cGy(RBE), comparing the defined technical limit of DFO=LP=1mm with DFO=3mm/LP=4mm. The latter may result from a pencil-beam scanning (PBS) system with static apertures. Plans employing a wedge showed an improvement for organs at risk sparing. Plan quality is strongly influenced by initial beam parameters. The impact of LP is more pronounced when compared to DFO. The latter becomes important in the treatment of posterior tumors near the macula, optic disc or optic nerve. The plan quality achieved by dedicated OPT nozzles in single- or double-scattering design might not be achievable with modified PBS systems.

Development and research of the press operating mechanism, made in the form of the wedge-joint mechanism with a curving wedge for separation operations

The applicability of a wedge-joint mechanism with a curving wedge in presses for the implementation of metal forming separation processes was substantiated. The paper states the fact that the wedge-joint mechanism graph of the deformation force change is the closest to the technological typical graph of the force change during separation. At the same time, the wedge-joint mechanism with a curving wedge has a lower height of the parts in comparison with the traditional crank mechanisms, which provides less elastic deformation and press dynamics. The use of the additional wedge mechanism in a press with the wedge-joint mechanism with a curving wedge to ensure the approximation motion is proved. This makes it possible to reduce the energy consumption for elastic deformation and further reduce the dynamic force. The mathematical models of the wedge-joint mechanism with a curving wedge, presented in the form of a two-slide link mechanism, were developed, allowing to perform its structural, kinematic, and dynamic analysis. Based on the analysis of the proposed mathematical models, dependencies were identified and a procedure for calculating the geometric, kinematic, and power parameters of wedge-joint mechanisms with a curving wedge for separation processes was developed. Comparison of the kinematic and dynamic analyses results carried out by analytical and graphic-analytical methods confirms the reliability of estimates, since their discrepancy is not more than 2.5%. Experimental studies have confirmed the adequacy of mathematical models. The error between the calculated and measured values of the forces on the slide does not exceed 10%.

Surgical correction of severe forms of idiopathic kyphoscolyosis in children

Background. Significant results have been achieved through the use of hybrid and transpedicular metal structures. However, when spinal systems are implanted during surgery in patients with severe forms and idiopathic scoliosis, a number of limitations arise. Not only the performance of corrective maneuvers during the operation but also the creation of mobility on the top of the main arc accompany the strategies of surgical treatment. Traditionally, mobilizing discectomy at the top of the spark is performed in patients with idiopathic scoliosis. Pedicle subtractional vertebrotomy and Ponte and Smith-Petersen osteotomy are most common in neuromuscular scoliosis and spinal deformity, with a predominance of the kyphotic component. Problems with correction of extremely low and neglected forms and idiopathic scoliosis in children remain.&#x0D; Aim. The present study aimed to provide a comparative analysis between using transpedicular spinal systems alone and in combination with a wedge osteotomy of the apical vertebra to correct spinal deformity in children with extremely severe right-sided idiopathic thoracic scoliosis.&#x0D; Materials and methods. The surgical treatment results of 20 children 15 to 17 years old with extremely severe forms of right-sided idiopathic thoracic kyphoscoliosis were included in the analysis. All patients underwent standard preoperative examination, including radiology, computed tomography, magnetic resonance imaging, and neurophysiological studies. The patients were divided into two groups according to the method used during the second stage of surgical treatment correction of deformity with the transpedicular system (1) alone or (2) in combination with a wedge osteotomy of the apical vertebra.&#x0D; Results. Patients from the first group showed an amount of scoliotic and kyphotic component correction ranging from 25% to 62% and from 21% to 56%, respectively. In patients from the second group, who underwent additional wedge osteotomy of the apical vertebrae during the operation, correction of the scoliotic and kyphotic components ranged from 36% to 74% and from 50% to 70%, respectively.&#x0D; Conclusion. In children with idiopathic thoracic kyphoscoliosis, performing a wedge corpectomy of the apical vertebral body is an effective additional mobilizing component, which allows achieving significant correction of both scoliotic and kyphotic curve components, restoring the physiological profile of the spine and body balance during the surgical intervention, and maintaining the achieved result during the long-term observation period.

Results of surgical therapy of bilateral colorectal liver metastases

Background: Surgery of colorectal liver metastases (CLM) may offer prolonged survival or even cure in resectable patients. However, bilateral CLM often require extended or multi-step resections to achieve complete tumor removal. Methods: Between 2000 and 2016, 152 patients were scheduled for potentially curative resection of bilateral CLM. Among these, 130 patients (85.5%) completed surgery whereas 22 (14.5%) developed irresectable disease during planned multi-step procedure. Of the 130 patients analyzed, 105 underwent single-step surgery: 55 major resections (38 of those with additional wedge resections) and 50 multiple wedge resections. The remaining 25 patients underwent multi-step resections. Portal vein embolization was performed in 26%, intraoperative additional RFTA in 24% of all patients. Results: Postoperative mortality was 0.8%. Free margins were achieved in 83%. 5-year survival was 34% in the entire group. In univariate survival analysis, positive margins, CLM > 30 mm, more than 3 CLM, age and colonic primaries were significantly associated with worse survival. In multivariate survival analysis, the resection margin, size and number of metastases and age were independent predictors of survival. Conclusion: Extended surgery of bilateral CLM provides acceptable OS and is associated with a low mortality. In our cohort, resection margin, size and number of metastases and age were independent predictors of survival.

Steady Mach reflection with two incident shock waves

Mach reflection in steady supersonic flow with two incident shock waves is studied. The second incident shock wave is produced by an additional deflection of the wedge lower surface, at some point ensuring that the two incident shock waves would intersect at the reflecting surface in case of normal reflection. Both theory and computational fluid dynamics (CFD) are used to study the flow structure and the influence of the second incident shock wave. The overall flow configuration, in case of Mach reflection, is shown to be composed of a triple shock structure, a shock/shock interaction structure and a shock/slipline reflection structure. Similar phenomenon, triggered by a high downstream pressure, has been observed before numerically, but not studied theoretically. The second incident shock wave reflects over the slipline to deflect the slipline more towards the reflecting surface, increasing thus the Mach stem height, advancing the transition of regular reflection to Mach reflection of the first incident shock wave, and causing an inverted Mach reflection below the usual von Neumann condition. A Mach stem height model built for a weak second incident shock wave is used to study the influence of the second incident shock wave on the Mach stem height. Both theory and CFD predict a maximum of the Mach stem height at some additional wedge deflection angle.

Bile leak and recurrence rate after pericystectomy using a water-jet device

Introduction: Cystic echinococcosis is a frequent cause of liver hydatid cysts and, when resectable, complete surgical removal with preservation of surrounding healthy liver tissue is the preferred treatment. Bile leak remains a postoperative complication that is bothersome for the patients and leads to longer hospital stay. Radical resection with the water-jet device would allow separation of different structure like liver tissue, vessels, and cyst wall by hydraulic pressure. The ejected saline solution separates the cyst wall on one side and vessels and bile ducts from liver parenchyma on the other side and allow their selective ligation. Methods: We present a series of nine patients undergoing pericystectomy using a water-jet device at a single tertiary referral center in Switzerland. Bile leak rate and re-infection rate were recorded. Patients were followed up with ultrasonography of the abdomen. Results: Nine patients underwent 10 pericystectomies. Diameter of the cysts was in mean 70 mm (SD40). Procedures lasted in mean 276 min (SD 70), hospital stay was in median 10 days. One bile leak occurred in a patient with an additional wedge resection using the crush clamp technique. Two patients developed postoperative complication Clavien-Dindo IIa. There was no re-infection, after a median follow up of 24.6 months. Conclusion: Pericystectomy using a water-jet device is surgically safe and provides a radical treatment for cystic echinococcosis. Moreover, it offers radical treatment in combination with maximum saving of parenchyma.

A faster and simpler way of operation for Meckel's diverticulum: basal ligation combined with intraoperative frozen section.

The key step in Meckel's diverticulectomy (MD) is to achieve complete resection of MD along with the ectopic epithelium. Currently main treatment methods for Meckel's diverticulum are either intestinal resection and anastomosis or wedge resection. Here we introduced a new method to treat MD. The goal of this study was to investigate the clinical effects and advantages of a new operation method for Meckel's diverticulum: basal ligation combined with intraoperative frozen section. 262 cases of Meckel's diverticulum were resected with simple basal ligation operation. Intraoperative frozen pathological section was performed to determine surgery strategies. Based on the existence of basal residual ectopic mucosa, surgery was either terminated or further wedge intestinal resection or bowel resection was performed. All 262 surgeries were successfully completed. Additional wedge resection or bowel resection was performed in only 23 of them due to the presence of ectopic basal residual gastric mucosa. No ectopic mucosa was found for the other cases, and the operation ended after basal ligation. All patients had no complications such as intestinal fistula, bleeding for 6months-7.6years after surgery. Intraoperative frozen pathological examination can well determine whether ectopic Meckel's diverticulum mucosa locates at the basal part. Basal ligation is a safe and effective operation method, and it can significantly shorten the operation time and postoperative fasting time.

Is the novel olecranon tension plate a valid alternative to tension band wiring of olecranon fractures? A biomechanical study on cadaver bones.

Tension band wiring (TBW) used for olecranon fractures is afflicted with a high rate of complications. The aim of this study was to compare the stability of the TBW versus an alternative, novel low-profile olecranon tension plate (OTP) with angular stable screws in a simulated complex fracture model. Nine fresh-frozen pairs of cadaver proximal ulnae with an oblique osteotomy and an additional wedge fragment simulating an unstable fracture were tested. The TBW and OTP were implanted pairwise. The elbow motion was simulated in a single-muscle model and ranged from full extension to 90° of flexion. The pulling force of the triceps tendon ranged from 50 to 200N. The displacement of the fracture fragments was measured with a video motion analysis system over 304 cycles. Data were assessed statistically using the Wilcoxon signed-rank test. The cyclic loading tests showed mean loosening of the fracture fragments at the articular surface of 0.56mm using TBW (SD 0.65) and 0.15mm for OTP (SD 0.39). There was no statistical significance in loosening between the two constructs (p=0.31). No plate breakage or screw loosening occurred. The low-profile OTP, using the principles of pre-tensioning, lag, cortical, and angular stable screws together, demonstrated similar stability after olecranon fracture fixation when compared with the TBW technique and a lag screw in the olecranon fracture model with a third wedge fragment.

Enteric Duplication Cysts in Children: A Single‐Institution Series with Forty Patients in Twenty‐Six Years

The purpose of the study was to evaluate our experience with enteric duplication cysts in 40 children during the past 26years, while assessing the variability of their presentations and to propose an algorithm for surgical management. We retrospectively analysed sex, age, clinical presentations, duplication site, surgical treatment, presence of ectopic tissue, complications, associated anomalies, and prognosis of 40 patients with gastrointestinal tract duplications who were surgically treated in our clinic. Overall, there was a predominance of boys (28 males, 70%; 12 females, 30%). The presenting symptom was vomiting in 23 patients, rectal bleeding in 11 patients, abdominal mass in 10 patients, abdominal pain in 9 patients, constipation in 6 patients, cough in 2 patients, and respiratory distress in 2 patients. In 30 patients, a complete excision of the cyst with additional segmental intestinal resection and anastomosis was performed. Cystectomy was performed in seven patients, while complete excision of the cyst with additional wedge resection was performed in two. A Wrenn procedure (mucosectomy) was performed in one patient. Due to the variability in the site of enteric duplications, a wide range of presenting symptoms can exist, which is challenging for diagnosis. In children with a diagnosis of acute abdomen, enteric duplication cysts should be considered, and these children should be further investigated for additional skeletal, urogenital, and gastrointestinal system pathologies. Surgical treatment depends on the site and type of the cyst.

Outcome and Learning Curve in 159 Consecutive Patients Undergoing Total Laparoscopic Hemihepatectomy.

Widespread implementation of laparoscopic hemihepatectomy is currently limited by its technical difficulty, paucity of training opportunities, and perceived long and harmful learning curve. Studies confirming the possibility of a short and safe learning curve for laparoscopic hemihepatectomy could potentially benefit the further implementation of the technique. To evaluate the extent and safety of the learning curve for laparoscopic hemihepatectomy. A prospectively collected single-center database containing all laparoscopic liver resections performed in our unit at the University Hospital Southampton National Health Service Foundation Trust between August 2003 and March 2015 was retrospectively reviewed; analyses were performed in December 2015. The study included 159 patients in whom a total laparoscopic right or left hemihepatectomy procedure was started (intention-to-treat analysis), including laparoscopic extended hemihepatectomies and hemihepatectomies with additional wedge resections, at a tertiary referral center specialized in laparoscopic hepato-pancreato-biliary surgery. Primary end points were clinically relevant complications (Clavien-Dindo grade ≥III). The presence of a learning curve effect was assessed with a risk-adjusted cumulative sum analysis. Of a total of 531 consecutive laparoscopic liver resections, 159 patients underwent total laparoscopic hemihepatectomy (105 right and 54 left). In a cohort with 67 men (42%), median age of 64 years (interquartile range [IQR], 51-73 years), and 110 resections (69%) for malignant lesions, the overall median operation time was 330 minutes (IQR, 270-391 minutes) and the median blood loss was 500 mL (IQR, 250-925 mL). Conversion to an open procedure occurred in 17 patients (11%). Clinically relevant complications occurred in 17 patients (11%), with 1% mortality (death within 90 days of surgery, n = 2). Comparison of outcomes over time showed a nonsignificant decrease in conversions (right: 14 [13%] and left: 3 [6%]), blood loss (right: 550 mL [IQR, 350-1150 mL] and left: 300 mL [IQR, 200-638 mL]), complications (right: 15 [14%] and left: 4 [7%]), and hospital stay (right: 5 days [IQR, 4-7 days] and left: 4 days [IQR, 3-5 days]). Risk-adjusted cumulative sum analysis demonstrated a learning curve of 55 laparoscopic hemihepatectomies for conversions. Total laparoscopic hemihepatectomy is a feasible and safe procedure with an acceptable learning curve for conversions. Focus should now shift to providing adequate training opportunities for centers interested in implementing this technique.

Pre-operative localization of solitary pulmonary nodules with computed tomography-guided hook wire: report of 181 patients.

BackgroundVideo-assisted thoracic surgery (VATS) is currently performed to diagnose and treat solitary pulmonary nodules (SPN). However, the intra-operative identification of deep nodules can be challenging with VATS as the lung is difficult to palpate. The aim of the study was to report the utility and the results of pre-operative computed tomography (CT)-guided hook wire localization of SPN.Methods All records of the patients undergoing CT-guided hook wire localization prior to VATS resection for SPN between 2002 and 2013 were reviewed. The efficacy in localizing the nodule, hook wire complications, necessity to convert VATS to thoracotomy and the histology of SPN are reported.ResultsOne hundred eighty-one patients (90 females, mean age 63 y, range 28–82 y) underwent 187 pulmonary resections after CT-guided hook wire localization. The mean SPN diameter was 10.3 mm (range: 4–29 mm). The mean distance of the lesion from the pleural surface was 11.6 mm (range: 0–45 mm). The mean time interval from hook wire insertion to VATS resection was 224 min (range 54–622 min). Hook wire complications included pneumothorax requiring chest tube drainage in 4 patients (2.1 %) and mild parenchymal haemorrhage in 11 (5.9 %) patients. Migration of the hook wire occured in 7 patients (3.7 %) although it did not affect the success of VATS resection (nodule location guided by the lung puncture site). Three patients underwent additional wedge resection by VATS during the same procedure because no lesion was identified in the surgical specimen. Conversion thoracotomy was required in 13 patients (7 %) for centrally localized lesions (6 patients) and pleural adhesions (7 patients). The mean operative time was 60 min (range 18–135 min). Pathological examination revealed a malignant lesion in 107 patients (59 %). The diagnostic yield was 98.3 %.ConclusionVATS resection for SPN after CT-guided hook wire localization for SPN is safe and allows for proper diagnosis with a low thoracotomy conversion rate.

Biomechanical Analysis of a Novel Wedge Locking Plate in a Porcine Tibial Model.

BackgroundThe purpose of this study was to analyze biomechanical properties of a novel wedge locking plate in medial open wedge high tibial osteotomy (OWHTO) in a porcine tibial model.MethodsA uniform 8-mm OWHTO was performed in 12 porcine tibiae. Six of them were subsequently fixed with the plate without a wedge, whereas the other 6 were additionally reinforced with a metal wedge of 8 mm. Biomechanical properties (stiffness, displacement of the osteotomy gap, and failure load) were evaluated under axial load. The different modes of failure were also investigated.ResultsThe plate showed an axial stiffness of 2,457 ± 450 N/mm with a wedge and 1,969 ± 874 N/mm without a wedge. The maximum failure load was 5,380 ± 952 N with a wedge and 4,354 ± 607 N without a wedge. The plate with a wedge had a significantly greater failure load and significantly less displacement of medial gap at failure than that without a wedge (p = 0.041 and p = 0.002, respectively). The axial stiffness was not different between the two types of fixation. Most failures were caused by lateral cortex breakage and there was no implant failure.ConclusionsThe novel wedge locking plate showed excellent biomechanical properties and an additional wedge provided significant improvement. This plate can be a good fixation method for OWHTO.

Outcome of TORS to tongue base and epiglottis in patients with OSA intolerant of conventional treatment.

Transoral robotic surgery (TORS) of the tongue base with or without epiglottoplasty represents a novel treatment for obstructive sleep apnea (OSA). The objective was to evaluate the clinical efficacy of TORS of the tongue base with or without epiglottoplasty in patients who had not tolerated or complied with conventional treatment (continuous positive airway pressure or oral appliance). Four-year prospective case series. The primary outcome measure was the apnea-hypopnea index (AHI) in combination with the Epworth Sleepiness Score (ESS). Mean oxygen saturation levels (SaO2) before and after TORS on respective sleep studies were also recorded. Secondary outcome measures included operative time and complications. Patient reported outcome measures (PROMs) assessed included voice, swallow and quality of life. Fourteen patients underwent TORS for tongue base reduction with ten having additional wedge epiglottoplasty. A 64% success rate was achieved with a normal post-operative sleep study in 36% of cases at 6months. There was a 51% reduction in the mean AHI (36.3 ± 21.4 to 21.2 ± 24.6, p = 0.02) and a sustained reduction in the mean Epworth Sleepiness Score (p = 0.002). Mean SaO2 significantly increased after surgery compared to pre-operative values (92.9 ± 1.8 to 94.3 ± 2.5, p = 0.005). Quality of life showed a sustained improvement 3months following surgery (p = 0.01). No major complications occurred. TORS of the tongue base with or without epiglottoplasty represents a promising treatment option with minimal morbidity for selected patients with OSA. Long-term prospective comparative evaluation is necessary to validate the findings of this study.

Wedge and gap plasmonic resonances in double nanoholes.

We study the plasmonic resonances of double nanoholes (DNHs) in metal films. These apertures exhibit the usual gap-mode Fabry-Pérot resonances, where the zeroth order resonance is determined by the waveguide cut-off and the first order resonance shows sensitivity to the film thickness. An additional wedge resonance is observed, which is sensitive to the curvature of the cusps in the DNHs, analogous to the wedge modes of single wedges. While the gap mode intensity increases dramatically with decreasing gap-width, the wedge mode intensity saturates since its field enhancement arises from the curvature of the metal film, like cylindrical Sommerfeld waves. Experimental transmission spectra agree well with finite-difference time-domain simulations showing these separate resonances. The controlled design of these resonances is critical for applications including optical tweezers, nonlinear conversion, sensing and spectroscopy.

Changes in Lung Function Parameters After Wedge Resections: A Prospective Evaluation of Patients Undergoing Metastasectomy

Pulmonary metastasectomy with lung-sparing local excisions is a widely accepted method of treating stage IV malignancies in selected cases. The ability to predict postoperative lung function is an unresolved issue, especially when multiple wedge resections are planned. To help develop a method to predict postoperative lung function after wedge resections, we present this prospective observational study. A total of 77 patients who underwent one or more wedge resections to remove lung metastases completed the study protocol. Spirometry results, diffusion capacity of lung for carbon monoxide (Dlco), and blood gases and potential confounding factors were measured prior to, immediately following, and 3 months after the procedure and were analyzed. Seventy-seven patients with a median age of 61.3 years underwent up to 22 wedge resections. The mean lung function losses were FVC (-7.5%), total lung capacity (TLC) (-7.9%), FEV(1) (-9.2%), and Dlco (-8.8%), and all were statistically significant (P < .001). The lung function losses also differed significantly between those having a single and those with more than eight wedge resections. Using regression analysis, we found that for every additional wedge resection, there was a reduction in FVC of 30 mL (0.7%), in TLC of 44 mL (0.65%), and in FEV(1) of 23 mL (0.58%). Metastasectomy by wedge resection significantly reduces lung function parameters. As a benchmark, we can predict a 0.6% decrease in spirometry values and Dlco for every additional wedge resection, and a decrease of approximately 5% that may be attributed to thoracotomy.

Pleural Abrasion for Mechanical Pleurodesis in Surgery for Primary Spontaneous Pneumothorax

Some patients with primary spontaneous pneumothorax suffer from recurrence of bullous lesions of the lung after resection. Mechanical pleurodesis by pleural abrasion is one of the standard procedures to prevent recurrence. However, there is actually little evidence that pleural abrasion reduces the recurrence of primary spontaneous pneumothorax. Our aim was to evaluate the efficacy of mechanical pleurodesis by pleural abrasion during thoracoscopic procedures for primary pneumothorax. From January 2003 to December 2009, 263 patients underwent 294 initial thoracoscopic wedge resections with or without pleural abrasion for primary spontaneous pneumothorax at the Samsung Medical Center. Medical records of patients were reviewed retrospectively. Thirty-one patients were excluded from the study due to various comorbidities. The remaining 232 patients underwent 257 thoracoscopic wedge resections with (165) or without (92) pleural abrasion. No mortality was observed. Seven additional chemical pleurodesis and 3 reoperations were performed due to persistent air leakage after initial surgery. There were 18 instances of recurrence, and the overall recurrence rate was 7.1%. Twelve additional wedge resections were performed because of recurrence after initial surgery. The mean duration of postoperative pleural drainage was 2.86 days. There were no significant differences in the recurrence rate (P=0.9499), and duration of chest tube drainage (P=0.5200) between the patients with and without pleural abrasion. Younger patients, especially below 17 years of age, had significant risk of recurrence (P<0.0001). Thoracoscopic wedge resection alone successfully controlled primary spontaneous pneumothorax. Additional pleural abrasion did not decrease the recurrence of pneumothorax after wedge resection of bullae for primary spontaneous pneumothorax. Younger age was associated with higher risk of recurrence.

High-Power Low-Noise Nd:YAP/LBO Laser With Dual Wavelength Outputs

A high-power single-frequency Nd:YAP/LBO laser with stable dual wavelength outputs is designed and built. The laser resonator satisfying optimal coupling condition for second-harmonic generation is in a configuration of a figure “8” shaped ring cavity consisting of two convex mirrors and two concave mirrors. An additional wedge YVO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> crystal is inserted in the resonator to act as a polarizer, so that the stability of the laser operation is improved. The maximum output powers of 4.5 W at 540 nm and 1.5 W at 1080 nm are simultaneously achieved. The measured power stabilities of the fundamental wave and the second-harmonic wave are ±0.32% and ±0.6% for 3 h, respectively.

The Shaping Effects of the Conversational Interview

The conversational research interview constitutes a complex and fraught context for personal accounts, and the methodological literature of the past few decades has acknowledged this. Theoretical discussions about representation, ethics, and power in interviews have been extended in empirical studies of actual interaction. Particularly useful for observing subtleties of talk between interviewer and interviewee are tools drawn from conversation analysis and other, overlapping forms of linguistic analysis. This article seeks to add to existing studies of interview interaction by proposing a strategy for examining the specifically generic features of interviewing. Genre, as framed by rhetorical theory, encompasses both form and social situation, allowing interviews to be framed as local enactments of historically regularized but flexible discursive forms. By focusing on interlocutors’ expectations around and linguistic action within the conventions of talk, genre offers a valuable additional wedge into an oft-used means for collecting narrative research data.