Mechanical and biological properties of poly-ε-caprolactone membrane for pleurodesis: A preclinical study in pigs.

BACKGROUND/PURPOSE: Biomaterial implants are emerging as a treatment choice for pleurodesis; however, the optimal biomaterial and form for managing spontaneous pneumothorax, particularly post-video-assisted thoracic surgery, remain under investigation. This study evaluated the mechanical and biological properties of the poly-ε-caprolactone (PCL) membrane as a sclerosing agent for pleurodesis in Landrace pigs. METHODS: Twenty-four Landrace pigs were split into two groups for mechanical abrasion and PCL membrane pleurodesis, with the latter group's PCL meshes inserted using video-assisted thoracic surgery. The mechanical and biological properties of the PCL membrane were assessed in pigs at three, six, and 12 months after the procedure. This assessment involved a range of techniques, such as the T-Peel test, macroscopic evaluation with a scoring scale, microscopic examination, and biomechanical and molecular weight analysis. RESULTS: The PCL membrane group outperformed the traditional abrasion group, with stronger adhesions seen over longer implantation durations. This group also showed superior and more consistent results in both macroscopic and microscopic evaluations compared to the control group. The membrane-based method was easier and faster to perform than the control group's method, and importantly, no mortality occurred following membrane implantation. CONCLUSION: This study is the pioneering effort to present long-term findings regarding the mechanical and biological properties of the PCL membrane in an in vivo animal model. The membrane demonstrated better adhesion ability than that of traditional abrasion and showed reassuring biocompatibility in both the pig model, suggesting its potential as treatment for patients with primary spontaneous pneumothorax. Further clinical studies are needed to support these observations.

Long-term outcomes after nonintubated versus intubated thoracoscopic lobectomy for clinical stage I non-small cell lung cancer: A propensity-matched analysis.

BACKGROUND: Nonintubated thoracoscopic lobectomy has been described as a feasible surgical treatment for early-stage lung cancer since 2011. Despite promising perioperative results, studies on tumor recurrence and long-term survival are very limited. This study was aimed to compare outcomes after thoracoscopic lobectomy with versus without intubation for stage I non-small cell lung cancer. METHODS: A retrospective data set including 115 and 155 patients who underwent nonintubated and intubated thoracoscopic lobectomy, respectively, between January 2011 and December 2013 was used to identify matched nonintubated and intubated cohorts (n = 97 per group) using a propensity score matching algorithm that accounted for confounding effects of preoperative patient variables. Primary outcome variables included freedom from recurrence and overall survival. Factors affecting survival were assessed using Cox regression analysis and Kaplan-Meier survival estimates. RESULTS: No perioperative mortality occurred in both groups. At an average follow-up of 74 months, comparing nonintubated thoracoscopic lobectomy with intubated procedure, no differences were observed in recurrence rates (14.4% vs. 25.8%, respectively; p = .057). Furthermore, no significant differences were noted in overall survival (97.9% vs. 93.8%, respectively; p = .144). Nonintubated thoracoscopic lobectomy was not found to be an independent predictor of recurrence (hazard ratio, .53; 95% confidence interval [CI], .28-1.02) or overall survival (hazard ratio, .33; 95% CI, .07-1.61). CONCLUSION: In this propensity-matched comparison, nonintubated thoracoscopic lobectomy was not associated with an increased risk for recurrence and overall survival during the 5-year follow-up. However, more randomized trials should be conducted for further validation of these results.

Locating stridor caused by tumor compression by using a multichannel electronic stethoscope: a case report.

A 67-year-old male patient with chronic obstructive pulmonary disease was admitted to a hospital in northern Taiwan for progressive dyspnea and productive cough with an enlarged left upper lobe tumor (5.3 × 6.8 × 3.9 cm3). Previous chest auscultation on outpatient visits had yielded diffuse wheezes. A localized stridor (fundamental frequency of 125 Hz) was captured using a multichannel electronic stethoscope comprising four microelectromechanical system microphones. An energy-based localization algorithm was used to successfully locate the sound source of the stridor caused by tumor compression. The results of the algorithm were compatible with the findings obtained from computed tomography and bronchoscopy (mean radius = 9.40 mm and radial standard deviation = 14.97 mm). We demonstrated a potential diagnostic aid for pulmonary diseases through sound-source localization technology based on respiratory monitoring. The proposed technique can facilitate detection when advanced imaging tools are not immediately available. Continuing effort on the development of more precise estimation is warranted.

Esophageal Metal Stents with Concurrent Chemoradiation Therapy for Locally Advanced Esophageal Cancer: Safe or Not?

BACKGROUND: The purpose of this study was to review the risks and benefits of concurrent chemoradiation therapy (CCRT) with esophageal self-expandable metal stents (SEMS) for the treatment of locally advanced esophageal cancer. MATERIALS AND METHODS: Between January 2014 and December 2016, the data from 46 locally advanced esophageal cancer patients who received CCRT at our institution were retrospectively reviewed. Eight patients who received CCRT concomitant with SEMS placement (SEMS plus CCRT group) and thirty-eight patients who received CCRT without SEMS placement (CCRT group) were identified. The risk of developing esophageal fistula and the overall survival of the two groups were analyzed. RESULTS: The rate of esophageal fistula formation during or after CCRT was 87.5% in the SEMS plus CCRT group and 2.6% in the CCRT group. The median doses of radiotherapy in the SEMS plus CCRT group and the CCRT group were 47.5 Gy and 50 Gy, respectively. SEMS combined with CCRT was associated with a greater risk of esophageal fistula formation than CCRT alone (hazard ratio [HR], 72.30; 95% confidence interval [CI], 8.62-606.12; p < .001). The median overall survival times in the SEMS plus CCRT and CCRT groups were 6 months and 16 months, respectively. Overall survival was significantly worse in the SEMS plus CCRT group than in the CCRT group (HR, 5.72; 95% CI, 2.15-15.21; p < .001). CONCLUSION: CCRT concomitant with SEMS for locally advanced esophageal cancer results in earlier life-threatening morbidity and a higher mortality rate than treatment with CCRT alone. Further prospective and randomized studies are warranted to confirm these observations. IMPLICATIONS FOR PRACTICE: Patients treated with SEMS placement followed by CCRT had higher risk of esophageal fistula formation and inferior overall survival rate compared with patients treated with CCRT alone. SEMS placement should be performed cautiously in patients who are scheduled to receive CCRT with curative intent.

Chemical pleurodesis for prolonged postoperative air leak in primary spontaneous pneumothorax.

BACKGROUND/PURPOSE: Prolonged air leak is the most common complication after thoracoscopic operation for primary spontaneous pneumothorax (PSP), and the role of chemical pleurodesis in treating air leaks remains unclear. This study evaluated the safety and efficacy of chemical pleurodesis with a comparison between minocycline and OK-432. METHODS: Between 1994 and 2011, 1083 PSP patients were treated by thoracoscopic operation. After the operation, patients with persistent air leak for 3 days or more were managed by minocycline or OK-432 pleurodesis. The demographic and outcome data for these patients were collected by retrospective chart review. RESULTS: Seventy-nine patients (7.3%) with prolonged air leak after thoracoscopy underwent minocycline pleurodesis (60 patients) or OK-432 pleurodesis (19 patients) as the primary treatment. The primary success rate was 63% (38/60) for minocycline pleurodesis and 95% (18/19) for OK-432 pleurodesis (p = 0.009). Postpleurodesis pain was common and comparable between the two groups. No major complications were noted after a total of 121 treatments. Patients undergoing primary OK-432 pleurodesis had shorter durations of postpleurodesis chest drainage (mean 8.5 vs. 2.3 days; p < 0.001) and postoperative hospital stay (mean 11.9 vs. 6.8 days; p < 0.001) than those undergoing primary minocycline pleurodesis. After a median follow-up of 16 months, recurrence was noted in one patient in the OK-432 group and none in the minocycline group. Long-term pulmonary function in the two groups was comparable. CONCLUSION: Chemical pleurodesis using OK-432 or minocycline is safe and convenient for prolonged air leak after thoracoscopic treatment for PSP. Our experience suggested that OK-432 may be more effective than minocycline in reducing air leak.

Corrigendum: Safety assessment of poly-ε-caprolactone in the treatment of primary spontaneous pneumothorax.

[This corrects the article DOI: 10.3389/fsurg.2024.1335144.].

Safety assessment of poly-ε-caprolactone in the treatment of primary spontaneous pneumothorax.

Background/purpose: Biomaterial-based implants are gaining traction as an option for pleurodesis treatment, yet the search for the best biomaterial or the most suitable shape to handle spontaneous pneumothorax continues. This forward-looking research assessed the use of a poly-ε-caprolactone membrane for its safety when applied as a sclerosant in pleurodesis procedures in human patients. Methods: From July 2017 to February 2018, we conducted a Phase I trial in which 10 patients with primary spontaneous pneumothorax were treated using video-assisted thoracoscopic surgery with a poly-ε-caprolactone membrane. These procedures encompassed bleb resection and mechanical pleurodesis through parietal pleura scrubbing. After resection, a 150 × 150 mm poly-ε-caprolactone membrane was applied to the apex. The primary outcome measures were the adverse events and laboratory outcomes. Results: After surgery, we observed no cardiopulmonary-related adverse events or indications of systemic inflammation. Furthermore, no episodes of hypothermia or hyperthermia occurred. Chest radiographs showed no evident pneumonitis or effusion associated with tissue reactions. The average follow-up duration was 31.7 ± 17.7 months, during which two patients exhibited recurrence. Conclusion: This study is the first to show the biocompatibility of poly-ε-caprolactone in humans, suggesting its potential as a treatment option for patients with primary spontaneous pneumothorax. Despite the relatively small number of patients, we maintain confidence in the reliability and safety profile of the PCL membrane, bolstered by its previously established efficacy in applications involving other organs. Phase II and phase III clinical studies are needed to support these observations.

Chemical pleurodesis for spontaneous pneumothorax.

Pneumothorax is defined as the presence of air in the pleural cavity. Spontaneous pneumothorax, occurring without antecedent traumatic or iatrogenic cause, is sub-divided into primary and secondary. The severity of pneumothorax could be varied from asymptomatic to hemodynamically compromised. Optimal management of this benign disease has been a matter of debate. In addition to evacuating air from the pleural space by simple aspiration or chest tube drainage, the management of spontaneous pneumothorax also focused on ceasing air leakage and preventing recurrences by surgical intervention or chemical pleurodesis. Chemical pleurodesis is a procedure to achieve symphysis between the two layers of pleura by sclerosing agents. In the current practice guidelines, chemical pleurodesis is reserved for patients unable or unwilling to receive surgery. Recent researches have found that chemical pleurodesis is also safe and effective in preventing pneumothorax recurrence in patients with the first episode of spontaneous pneumothorax or after thoracoscopic surgery and treating persistent air leakage after thoracoscopic surgery. In this article we aimed at exploring the role of chemical pleurodesis for spontaneous pneumothorax, including ceasing air leakage and preventing recurrence. The indications, choice of sclerosants, safety, effects, and possible side effects or complications of chemical pleurodesis are also reviewed here.

Drainless thoracoscopic surgery should be avoided in primary spontaneous pneumothorax with pleural adhesion.

OBJECTIVES: Drainless thoracoscopic surgery, defined by omitting chest drain after surgery, has been demonstrated to be feasible in selected patients for pulmonary resection. However, drainless procedure for the treatment of primary spontaneous pneumothorax has raised concerns for its safety and thus has been less often reported. We aimed to share our preliminary experience regarding how to select patients with spontaneous pneumothorax for this procedure. METHODS: A retrospective study recruiting 303 consecutive patients with the diagnosis of spontaneous pneumothorax undergoing thoracoscopic surgery in our centre from August 2016 to June 2020 was done. After careful selection, the chest drain was omitted in selected patients who underwent non-intubated uniportal thoracoscopic surgery. Patients' clinical characteristics and perioperative outcomes were analysed. RESULTS: A total of 34 patients underwent drainless thoracoscopic surgery for the treatment of spontaneous pneumothorax. Pleural adhesion was noted in 9 patients during surgery, and all of them (100%) developed residual pneumothorax, among which intercostal drainage was required in 2 (22.2%) patients and ipsilateral pneumothorax recurred 3 years after surgery in 1 (11.1%) patient. Among the remaining 25 without pleural adhesion, 17 (68.0%) developed minor residual pneumothorax (P = 0.006), which all resolved spontaneously within 1-2 weeks, with no complications or recurrence during postoperative follow-up for at least 2 years. CONCLUSIONS: Drainless thoracoscopic surgery for the treatment of primary spontaneous pneumothorax is feasible but can be risky without careful patient selection. In our experience, the drainless procedure should be avoided in patients with identifiable pleural adhesion noted during surgery.

Evaluation of pleurodesis by poly-ε-caprolactone (PCL) gel in an animal model using New Zealand white rabbits.

BACKGROUND/PURPOSE: Pleurodesis with biomaterial implant is an emerging treatment method for pleural diseases. However, the ideal biomaterial or the optimal form for the common diseases is still under investigation. In our previous study, Poly-ε-caprolactone (PCL) membrane produces significant pleurodesis in New Zealand White rabbit animal models. METHODS: We investigate the Poly-ε-caprolactone (PCL) gel pleurodesis by animal models using New Zealand White rabbits, which were sacrificed for examination after one month. Thirty-Six New Zealand White rabbits were randomized into three groups equally to undergo procedures. Gross pleurodesis scoring was evaluated. Additionally, inflammation and fibrosis scoring were done under microscopic evaluation, as well as Western blot analysis. RESULTS: Gross evaluation of pleurodesis score revealed that lower concentrated PCL gel (10%) produced moderate pleural adhesion, while higher concentrated PCL gel (25%) showed significantly higher pleurodesis scores. (P < 0.05) Control group with thoracostomy alone produced almost no pleurodesis (P < 0.05). Western blot showed fibronectin expression was more evident in the 25% PCL gel than 10% one. CONCLUSION: PCL gel induced significant degree of pleurodesis in the rabbits. The 25% PCL gel produces more intensive adhesion than 10% one. Fibronectin plays an important role in the process of pleurodesis. Further study is required for the clinical application of the promising biomaterial with gel form.

Emergency video-assisted thoracic surgery for ruptured pulmonary arteriovenous malformation-related hemothorax in a pregnant woman: a case report.

BACKGROUND: Pulmonary arteriovenous malformations are rare vascular abnormalities that permit direct communication between the pulmonary artery and vein. During pregnancy, pulmonary arteriovenous malformation carries an increased risk of enlargement and rupture, which could lead to life-threatening hemothorax. This is the first case reporting successful thoracoscopic surgery for a pregnant woman with pulmonary arteriovenous malformation rupture-related hemothorax. CASE PRESENTATION: We present a case of a 32-year-old pregnant Asian woman (31 weeks' gestation) whose pulmonary arteriovenous malformation ruptured, leading to right-sided spontaneous tension hemothorax. First, an emergency cesarean section for hypovolemic shock-related fetal distress was performed to save the baby. Immediately afterwards, video-assisted thoracic surgery with the single-incision approach allowed us to successfully obtain hemostasis and eradication of abnormal vasculature by conducting wedge resection of the pulmonary arteriovenous malformation. CONCLUSIONS: Emergency thoracoscopic surgery for a pregnant woman with pulmonary arteriovenous malformation rupture-related hemothorax is safe and feasible. In contrast to transcatheter arterial embolization, video-assisted thoracic surgery could simultaneously achieve hemostasis for prevention of mortality, eradication of abnormal vasculature, and removal of massive thrombi.

Traumatic left main bronchial rupture: delayed but successful outcome of robotic-assisted reconstruction.

Tracheobronchial injuries are rare but life-threatening conditions in patients with blunt thoracic trauma. The diagnosis and management of such injury may often be delayed due to other concomitant severe injuries. No reported case of a robotic-assisted bronchial reconstruction has ever been performed for a traumatic bronchial injury. A 23-year-old male suffered from traumatic left main bronchial (LMB) rupture with an initial presentation of pneumothorax and pneumomediastinum that eventually progressed to left main bronchus fibrosis and total obstruction, which led to left lung atelectasis and consolidation. Minimally invasive robotic-assisted sleeve surgery, 33 days after the initial trauma, successfully reconstructed the left main bronchus with satisfactory morphological and functional results. Recognition of a bronchial injury and precise localization of the lesion is mandated to ensure a prompt and adequate salvage surgical procedure in order to help patients recover from this critical condition.

The robotic approach for enucleation of a giant esophageal lipoma.

An 87-year-old man, who had been experiencing progressive dysphagia and slight chest discomfort for 12 months, presented for an esophagram with a diagnosis of achalasia. A giant esophageal lipoma (14.5- × 4.5- × 3.5-cm) that caused symptomatic dysphagia and a dilated esophagus was revealed by computed tomography and endoscopic esophageal ultrasound. For such a huge esophageal lipoma in a geriatric patient, we successfully enucleated the mediastinal lesion via a minimally invasive approach using the da Vinci S Surgical System.

Does ethanol activate G-protein coupled inwardly rectifying K+ channels?

G-protein coupled inwardly rectifying K+ (GIRK) channels have been reported to be targets of ethanol actions. We investigated if ethanol affects native GIRK channels in rat brain tissues at clinically relevant concentrations using brain slices containing the ventrolateral periaqueductal gray (PAG), an area related to pain regulation. Ethanol did not affect the membrane current elicited by hyperpolarization ramps at concentrations up to 150 mM. However, at 200-300 mM, which is above the lethal level, it activated a barium-sensitive GIRK current in 30-57% of neurons. In neurons unresponsive to ethanol, baclofen, the mu-opioid or nociceptin successfully activated GIRK channels. It is suggested that GIRK channels of the ventrolateral PAG are unlikely to be targets of the analgesic action of ethanol.

Prenatal morphine exposure decreases analgesia but not K+ channel activation.

The present study has investigated the possible supraspinal adaptive changes induced by prenatal administration of morphine, including morphine-induced supraspinal antinociception in vivo, the density and binding affinity of mu-opioid receptors in the brain and the cellular action of morphine in brain slices in vitro. The cellular action of morphine was assessed by its activation of K+ channels in the ventrolateral periaqueductal gray (PAG), a crucial area for the supraspinal analgesic effect of morphine. Female rats were treated with morphine 7 days before mating at 2 mg/kg. The treatment was continued during pregnancy and after delivery at doses which increased by 1 mg/kg every 2 weeks. Experiments were conducted in the offspring at p14 days. Prenatal morphine exposure induced tolerance to supraspinal morphine-induced tail-flick response. The binding affinity and maximal binding of [(3)H]DAMGO in whole brain were not significant different between the morphine- or saline-treated dams. Autoradiographic analysis shows that the mu-opioid receptor density was decreased in the striatum, thalamus and amygdala but not in the midbrain, nucleus accumbens, hippocampus or cortex in morphine offspring. In ventrolateral PAG neurons, morphine activated inwardly rectifying K+ channels in 59% of recorded neurons of morphine offspring. Neither the magnitude of K channel activation nor the percentage of sensitive neurons was different between the saline- and morphine-treated offspring. It is concluded that prenatal morphine exposure induces tolerance to supraspinal analgesia and this tolerance is not attributed to a change in the mu-opioid receptor density or the receptor-function coupling efficiency in the midbrain periaqueductal gray.