Agitation Techniques to Enhance Drainage of Retained Hemothorax.

Background. Retained hemothorax (RH) is a common problem in cardiothoracic and trauma surgery. We aimed to determine the optimum agitation technique to enhance thrombus dissolution and drainage and to apply the technique to a porcine-retained hemothorax. Methods. Three agitation techniques were tested: flush irrigation, ultrasound, and vibration. We used the techniques in a benchtop model with tissue plasminogen activator (tPA) and pig hemothorax with tPA. We used the most promising technique vibration in a pig hemothorax without tPA. Statistics. We used 2-sample t tests for each comparison and Cohen d tests to calculate effect size (ES). Results. In the benchtop model, mean drainages in the agitation group and control group and the ES were flush irrigation, 42%, 28%, and 2.91 (P = .10); ultrasound, 35%, 27%, and .76 (P = .30); and vibration, 28%, 19%, and 1.14 (P = .04). In the pig hemothorax with tPA, mean drainages and the ES of each agitation technique compared with control (58%) were flush irrigation, 80% and 1.14 (P = .37); ultrasound, 80% and 2.11 (P = .17); and vibration, 95% and 3.98 (P = .06). In the pig hemothorax model without tPA, mean drainages of the vibration technique and control group were 50% and 43% (ES = .29; P = .65). Discussion. In vitro studies suggested flush irrigation had the greatest effect, whereas only vibration was significantly different vs the respective controls. In vivo with tPA, vibration showed promising but not statistically significant results. Results of in vivo experiments without tPA were negative. Conclusion. Agitation techniques, in combination with tPA, may enhance drainage of hemothorax.

Comparing global and local maps of the Caribbean pine forests of Andros, home of the critically endangered Bahama Oriole.

Forest loss is occurring at alarming rates across the globe. The pine rockland forests of Andros, The Bahamas, likely represent some of the largest stands of Bahamian subspecies of Caribbean pine in the world. Given the unique species that inhabit these pine forests, such as the endemic and critically endangered Bahama Oriole, monitoring habitats on Andros is crucial to inform conservation planning. We developed a 2019 land classification map to assess the status of nine terrestrial habitats on Andros. Our Random Forest classification model predicted habitat classes with high overall accuracy. Caribbean pine was the dominant land class making up roughly one-third of the total terrestrial area. Whereas much of the pine forest area was found as small patches, most were close to other patches of pine suggesting isolation of forest patches is low. We compared our known intact forest areas to recent forest loss identified by the Hansen et al. Global Forest Change product and assessed areas of habitat disturbance in high-resolution imagery. Our results suggest that this global map overpredicted forest loss on Andros. The small degree of true forest loss on Andros was driven mostly by anthropogenic activity. A cross-tabulation of the Hansen forest loss with fire data showed that understory fires were frequently associated with falsely classified deforestation. Given the threats of climate change to this open forest type-intensifying fire regimes, strengthening hurricanes, and sea level rise-monitoring changes in open forest extent is a critical task across the Caribbean region and the world.

How to select patients for antireflux surgery? The ICARUS guidelines (international consensus regarding preoperative examinations and clinical characteristics assessment to select adult patients for antireflux surgery).

OBJECTIVE: Antireflux surgery can be proposed in patients with GORD, especially when proton pump inhibitor (PPI) use leads to incomplete symptom improvement. However, to date, international consensus guidelines on the clinical criteria and additional technical examinations used in patient selection for antireflux surgery are lacking. We aimed at generating key recommendations in the selection of patients for antireflux surgery. DESIGN: We included 35 international experts (gastroenterologists, surgeons and physiologists) in a Delphi process and developed 37 statements that were revised by the Consensus Group, to start the Delphi process. Three voting rounds followed where each statement was presented with the evidence summary. The panel indicated the degree of agreement for the statement. When 80% of the Consensus Group agreed (A+/A) with a statement, this was defined as consensus. All votes were mutually anonymous. RESULTS: Patients with heartburn with a satisfactory response to PPIs, patients with a hiatal hernia (HH), patients with oesophagitis Los Angeles (LA) grade B or higher and patients with Barrett's oesophagus are good candidates for antireflux surgery. An endoscopy prior to antireflux surgery is mandatory and a barium swallow should be performed in patients with suspicion of a HH or short oesophagus. Oesophageal manometry is mandatory to rule out major motility disorders. Finally, oesophageal pH (±impedance) monitoring of PPI is mandatory to select patients for antireflux surgery, if endoscopy is negative for unequivocal reflux oesophagitis. CONCLUSION: With the ICARUS guidelines, we generated key recommendations for selection of patients for antireflux surgery.

Pleural electrical impedance is a sensitive, real-time indicator of pneumothorax.

BACKGROUND: Chest tube management protocols, particularly in patients with alveolar-pleural air leak due to recent surgery or trauma, are limited by concerns over safety, especially concerns about rapid and occult development of pneumothorax. A continuous, real-time monitor of pneumothorax could improve the quality and safety of chest tube management. We developed a rat model of pneumothorax to test a novel approach of measuring electrical impedance within the pleural space as a monitor of lung expansion. MATERIALS AND METHODS: Anesthetized Sprague-Dawley rats underwent right thoracotomy. A novel impedance sensor and a thoracostomy tube were introduced into the right pleural space. Pneumothorax of varying volumes ranging from 0.2 to 20 mL was created by syringe injection of air via the thoracostomy tube. Electrical resistance measurements from the pleural sensor and fluoroscopic images were obtained at baseline and after the creation of pneumothorax and results compared. RESULTS: A statistically significant, dose-dependent increase in electrical resistance was observed with increasing volume of pneumothorax. Resistance measurement allowed for continuous, real-time monitoring of pneumothorax development and the ability to track pneumothorax resolution by aspiration of air via the thoracostomy tube. Pleural resistance measurement demonstrated 100% sensitivity and specificity for all volumes of pneumothorax tested and was significantly more sensitive for pneumothorax detection than fluoroscopy. CONCLUSIONS: The electrical impedance-based pleural space sensor described in this study provided sensitive and specific pneumothorax detection, which was superior to radiographic analysis. Real-time, continuous monitoring for pneumothorax has the potential to improve the safety, quality, and efficiency of postoperative chest tube management.

Diagnosis of anastomotic leak: electrolyte detection versus barium fluoroscopy.

BACKGROUND: We recently described a new method of diagnosing anastomotic leak using the detection of electrical changes induced by electrolyte extravasation from a surgically created gastric leak site in experimental rats. We sought to compare the sensitivity and specificity of anastomotic leak detection for this method to that of upper gastrointestinal (GI) barium fluoroscopy. METHODS: Experimental rats with a surgically created gastric leak site and controls were interrogated as to the presence of leak using either the electrolyte-gated leak detection method or upper GI barium fluoroscopy. The sensitivity and specificity of leak detection for the two methods were compared. RESULTS: The sensitivity and specificity of electrolyte-gated leak detection were both 100% (95% confidence interval 69-100%). Barium upper GI fluoroscopy misidentified one leak as a control and one control as a leak, for a sensitivity and specificity of 80% each (95% confidence interval 37-97%). No statistically significant difference was seen between electrolyte-gated leak detection and barium upper GI fluoroscopy in terms of the sensitivity and specificity of anastomotic leak detection. CONCLUSIONS: Electrolyte-gated leak detection was similarly sensitive and specific for anastomotic leak detection as upper GI barium fluoroscopy, the current standard. The electrolyte-gated method has the advantages of an inert contrast agent (normal saline) and the possibility of performing leak interrogation at the bedside. Electrolyte-gated leak detection might represent a plausible alternative to upper GI barium fluoroscopy for routine postoperative anastomotic leak surveillance after esophagectomy or other foregut surgery.

Lung lobectomy surgical approach and resource utilization differ by anatomic lobe in a statewide discharge registry.

Background: Anatomic lobe-specific differences with respect to pulmonary lobectomy have been suggested in the thoracic surgery literature but hard data has been lacking in larger population studies in part due to coding systems that do not distinguish pulmonary lobectomy by anatomic lobe. International Classification of Diseases, Tenth Revision (ICD-10) procedure codes, adopted in the United States in 2015, may provide novel methodologic accessibility for pulmonary lobectomy studies as they classify lobectomy operations by specific anatomic lobe. We queried the Texas Inpatient Public Use Data File (TPUDF) ICD-10 codes for both open and endoscopic approach lobectomy with a specific view to differences based on anatomic lobes. Methods: Between fourth fiscal quarter (Q4) 2015 and Q4 2017, all pulmonary lobectomy operations performed in Texas state-licensed hospitals were identified by querying the TPUDF for ICD-10 procedure codes for pulmonary lobectomy as classified by anatomic lobe. Surgical approach, additional procedures and diagnosis codes, length of hospital stay (LOS), and discharge status were recorded with aggregate values undergoing statistical analysis. Results: Right and left upper versus lower lobe resections were more prevalent however minimally invasive surgery was less commonly performed for upper than right lower lobectomy. LOS, irrespective of surgical approach, was longer for upper versus lower lobe resection as was need for transfer to additional inpatient facilities. LOS was longer and need for additional surgical or procedural interventions days after the primary procedure of lobectomy was greater for right versus left upper lobe resection, suggesting some differential properties of the right versus left pleural space. Conclusions: The marked clinical differences between anatomic lobes in the setting of pulmonary lobectomy observed in this study have the potential to translate to differences in expected hospital and health system costs and surgeon time-expenditure and experience premium that currently have no mechanism for their accounting. These findings highlight the value of ICD-10 coding for analysis of pulmonary lobectomy in administrative databases and suggest a possible path to more informed patient counseling and equitable hospital and surgeon reimbursement based on payment adjustment by anatomic lobe in pulmonary lobectomy operations.

Intrapleural Impedance Sensor Real-Time Tracking of Pneumothorax in a Porcine Model of Air Leak.

In patients with alveolar-to-pleural air leak due to recent surgery or trauma, clinicians tend to manage chest tubes with suction therapy. Nonsuction therapy is associated with shorter chest tube duration but also a higher risk of pneumothorax. We sought to develop an intrapleural electrical impedance sensor for continuous, real-time monitoring of pneumothorax development in a porcine model of air leak as a means of promoting nonsuction therapy. Using thoracoscopy, 2 chest tubes and the pleural impedance sensor were introduced into the pleural space of 3 pigs. Continuous air leak was introduced through 1 chest tube by carbon dioxide insufflation. The second chest tube was placed to suction then transitioned to no suction at increasingly higher air leaks until pneumothorax developed. Simultaneously, real-time impedance measurements were obtained from the pleural sensor. Fluoroscopy spot images were captured to verify the presence or absence of pneumothorax. Statistical Analysis Software was used throughout. With the chest tube on suction, a fully expanded lung was identified by a distinct pleural electrical impedance respiratory waveform. With transition of the chest tube to water seal, loss of contact of the sensor with the lung resulted in an immediate measurement of infinite electrical impedance. Pneumothorax resolution by restoring suction therapy was detected in real time by a return of the normal respiratory impedance waveform. Pleural electrical impedance monitoring detected pneumothorax development and resolution in real time. This simple technology has the potential to improve the safety and quality of chest tube management.

Esophageal trauma.

The anatomy of the esophagus is unique in that it traverses the neck, chest, and abdomen. As a result, surgeons need to be familiar with the anatomy of all three of these areas to be facile and comfortable in performing esophageal surgery. Traumatic injuries to the esophagus encompass a heterogeneous group of injuries that can be iatrogenic, external, or from physiologic forces. Primary repair of traumatic injuries is preferred when possible; however, if systemic sepsis is present and esophageal resection becomes necessary due to extensive injury or inflammation, immediate reconstruction should be delayed in most cases. Successful management of traumatic esophageal injuries requires prompt and accurate diagnosis and treatment tailored specifically to both the type of injury as well as to the patient's overall clinical condition.

Tracheobronchial injury.

Tracheobronchial injuries (TBI) can be challenging to diagnose, manage, and definitively treat. They encompass a heterogeneous group of injuries that are often associated with other injuries. Although relatively rare, diagnosis and treatment of TBI often requires skillful and creative airway management, careful diagnostic evaluation, and operative repairs that are often resourceful and necessarily unique to the given injury. An experienced surgeon with a high level of suspicion and the liberal use of bronchoscopy constitute the major tools necessary for diagnosing and treating these injuries. Most TBI can be repaired primarily using a tailored surgical approach and techniques specific to the injury. Associated injuries are common, and surgeons must be knowledgeable in treating a wide variety of physiologic abnormalities, especially those involving the chest wall and lung parenchyma, if a successful outcome is to be achieved in the management of these often challenging patients.

Overview of thoracic trauma in the United States.

Most patients with injuries to the chest (approximately 75%) can usually be managed expectantly with simple tube thoracostomy and volume resuscitation [1,11,21-24]. As a result, initial care of these patients is usually straightforward and often performed adequately by emergency room physicians and general surgeons. Tertiary care of these patients is often multidisciplinary in nature, however, and communication with the thoracic surgeon is essential to minimize mortality and long-term morbidity. Improvement in the understanding of the underlying molecular physiologic mechanisms involved in the various traumatic pathologic processes, and the advancement of diagnostic techniques, minimally invasive approaches, and pharmacologic therapy, all continue to contribute to decreasing the morbidity and mortality of these critically injured patients.

The efficacy of inhaled nanoparticle tacrolimus in preventing rejection in an orthotopic rat lung transplant model.

OBJECTIVE: The immunosuppressive efficacy of inhaled nanoparticle tacrolimus was compared with systemic tacrolimus in a rodent allogeneic lung transplant model. METHODS: Sixteen rats underwent allogeneic left orthotopic lung transplantation and were divided into 3 treatment groups: (1) inhaled nanoparticle tacrolimus: 6.4 mg tacrolimus/6.4 mg lactose twice per day; (2) intramuscular tacrolimus: 1 mg/kg tacrolimus once per day; and (3) inhaled lactose: 6.4 mg of lactose twice per day. Five days after transplant, the rats were necropsied and underwent histologic rejection grading and cytokine analysis. Trough levels of tacrolimus were measured in allograft, blood, and kidney. RESULTS: Both intramuscular (n = 6) and nanoparticle tacrolimus (n = 6) rats displayed lower histologic grades of rejection (mean scores 3.4 ± 0.6 and 4.6 ± 0.9, respectively) when compared with lactose rats (n = 4) (mean score 11.38 ± 0.5, P = .07). Systemic tacrolimus trough levels (median) were lower in nanoparticle tacrolimus-treated rats versus intramuscular-treated rats (29.2 vs 118.6 ng/g; P < .001 in kidney, and 1.5 vs 4.8 ng/mL; P = .01 in blood). CONCLUSIONS: Inhaled nanoparticle tacrolimus provided similar efficacy in preventing acute rejection when compared with systemic tacrolimus while maintaining lower systemic levels.

Concomitant weekly cisplatin and thoracic radiotherapy for Pancoast tumors of the lung: pilot experience of the San Antonio Cancer Institute.

Pancoast (superior sulcus tumors) comprise a subset of non-small-cell lung cancers that have a unique clinical presentation by virtue of the locoregional pattern of disease progression. We herein report a brief report on our group's pilot experience in managing these challenging lung neoplasms with an aggressive concomitant modality approach. These results and those of the recent Southwest Oncology-lead Intergroup prospective phase 2 trial (SWOG-9416/INT-0160) support the use of concomitant chemoradiation followed by an attempt at surgical resection.

Effect of inhaled tacrolimus on ischemia reperfusion injury in rat lung transplant model.

OBJECTIVE: Systemic tacrolimus therapy has been shown to protect against lung ischemia-reperfusion injury in animal models. We sought to investigate on a functional and cellular level if inhaled nanoparticle tacrolimus administered to the donor lung before procurement could similarly attenuate ischemia-reperfusion injury after lung transplant. METHODS: An isogenic orthotopic rat model of single left lung transplant was used. Donor animals were pretreated with inhaled tacrolimus (treatment group) or inhaled lactose (controls) before lung procurement. Lung grafts were subjected to 3 hours of cold ischemia followed by 4 hours of reperfusion after graft implantation. Recipient animal arterial blood gas measurement and isograft wet to dry weight ratios were obtained. Macrophage, neutrophil, and T-cell accumulation and activation in lung isografts, including γδ T-cell, T-helper, and cytotoxic T-cell subtypes were analyzed by flow cytometry. Tacrolimus levels were measured in the lung isograft using liquid chromatography/mass spectrometry. Isograft cytokine levels were measured with commercial enzyme-linked immunosorbent assay and microbead array kits. RESULTS: Oxygenation in treatment group animals was significantly higher than in controls. The presence of macrophages, neutrophils, and all T-cell subtypes in the isografts as well as isograft levels of inflammatory cytokines were all less in the treatment group versus controls, although no single variable achieved statistical significance. CONCLUSIONS: Inhaled nanoparticle tacrolimus treatment of lung donors is associated with an attenuation of ischemia-reperfusion injury on a functional and cellular level in lung transplant.

Transthoracic repair of slipped Nissen fundoplications: technique and results.

BACKGROUND: Laparoscopic Nissen fundoplication is a common operation performed for reflux disease, generally with good results. A small percentage of patients experience transthoracic migration of the wrap, causing recurrent symptoms and eventually requiring transthoracic repair. METHODS: A retrospective chart review was performed for all patients who underwent a transthoracic repair of a slipped Nissen fundoplication at our institution from 2006 to 2010. Data included demographics, previous antireflux operations, symptoms at presentation, findings at operation, and overall outcome. RESULTS: Sixteen patients with a mean age of 61 years (range, 51-76 years) were identified who fit inclusion criteria. The most common presenting symptom was pain. Intraoperative findings included hiatal breakdown in all patients, shortened esophagus in 10 (62%) patients, and foreign body/mesh in 4 (25%) patients. Nine (56%) patients underwent a Collis gastroplasty along with a Nissen fundoplication. Nissen fundoplication alone was performed in 6 (38%) patients and a Belsey fundoplication with a Collis gastroplasty was performed in 1 (6%) patient. Minor complications occurred in 4 (25%) patients and major complications were seen in 2 (13%) patients. The median length of stay was 9 days (range, 6-30 days). There were no postoperative deaths. Overall, 12 (75%) of the patients were judged to have a good outcome, 3 (19%) a fair outcome, and 1 (6%) a poor outcome over a median 9-month follow-up. CONCLUSIONS: Transthoracic repair in patients who have had transthoracic migration of a previous Nissen fundoplication has acceptable surgical outcome and affords symptomatic relief to the majority of patients.

Feasibility of video-assisted thoracoscopic surgery lobectomy in Veterans Administration patients.

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) pulmonary lobectomy has been associated with decreased complication rates and length of stay compared with lobectomy by thoracotomy. No studies have addressed VATS lobectomy in Veterans Administration (VA) patients. METHODS: A retrospective review was undertaken of 50 VATS lobectomies performed between August 2007 and June 2009 by one surgeon in a VA hospital, a university-affiliated county hospital, and a private community hospital. RESULTS: VA patients had more medical comorbidities, poorer lung function, greater current smoker status, and fewer preoperative biopsies. Pleural adhesions or hilar lymphadenopathy were encountered more commonly in VA than nonfederal patients. Surgical times and number of procedures performed were greater in VA patients. There was no statistically significant difference in the risk of postoperative complications or chest tube duration although length of stay was longer for VA patients. CONCLUSIONS: VATS lobectomy is feasible in a VA setting. The evidence strongly suggests that veterans can benefit from VATS lobectomy in terms of improved outcomes and diminished length of stay compared with thoracotomy.

Anastomotic leak detection by electrolyte electrical resistance.

OBJECTIVE: To characterize a new method of postoperative gastrointestinal leak detection based on electrical resistance changes due to extravasated electrolyte contrast. BACKGROUND: Postoperative gastrointestinal leak results in increased patient morbidity, mortality, and hospital costs that can be mitigated by early diagnosis. A sensitive and specific diagnostic test that could be performed at the bedside has the potential to shorten the time to diagnosis and thereby improve the quality of treatment. MATERIALS AND METHODS: Anaesthetized rats underwent celiotomy and creation of a 5-mm gastrotomy. In experimental animals, electrical resistance changes were measured with a direct current ohmmeter after the introduction of 5 cc of 23.4% NaCl electrolyte solution via gavage and measured with a more sensitive alternating current ohmmeter after the gavage of 1-5 cc of 0.9% NaCl. Comparison was made to negative controls and statistical analysis was performed. RESULTS: Leakage from the gastrotomy induced by as little as 1 cc of gavage-delivered 0.9% NaCl contrast solution was detectable as a statistically significant drop in electrical resistance when compared to results from negative controls. CONCLUSION: Electrical resistance change associated with electrolyte-gated leak detection is highly sensitive and specific and has the potential to be rapidly translated into clinical settings.

Characterization and pharmacokinetic analysis of tacrolimus dispersion for nebulization in a lung transplanted rodent model.

Lung transplantation animal models have been well established and enabled the investigation of a variety of new pharmacotherapeutic strategies for prevention of lung allograft rejection. Direct administration of immunosuppressive agents to the lung is a commonly investigated approach; however, can prove challenging due to the poor solubility of the drug molecule, the tortuous pathways of the lung periphery, and the limited number of excipients approved for inhalation. In this study, we aimed to evaluate a solubility enhancing formulation of tacrolimus for localized therapy in a lung transplanted rat model and determine the extent of drug absorption into systemic circulation. Characterization of the nebulized tacrolimus dispersion for nebulization showed a fine particle fraction (FPF) of 46.1% and a mass median aerodynamic diameter (MMAD) of 4.06 microm. After single dose administration to transplanted and non-transplanted rats, a mean peak transplanted lung concentration of 399.8+/-29.2 ng/g and mean peak blood concentration of 4.88+/-1.6 ng/mL were achieved. It is theorized that enhanced lung retention of tacrolimus is due to lipophilic associations with bronchial tissue and phospholipid surfactants in lung fluid. These findings indicate that tacrolimus dispersion for nebulization can achieve highly localized therapy for lung transplant recipients.