Aortic Healing Appears to Occur Rapidly after Successful Endovascular Sealing of Blunt Thoracic Aortic Injury.

BACKGROUND: The traumatic nature of blunt thoracic aortic injury (BTAI) would suggest that healing of the aorta would occur once the injured area is shielded from aortic pressure. This would be in contrast to degenerative aortic diseases which often continue to degenerate despite coverage. We hypothesize that after successful thoracic aortic endografting (TEVAR) that the aorta rapidly heals itself leaving minimal to no trace of the residual injury. METHODS: BTAI that were successfully covered with TEVAR from 2006 to 2019 were collected. Those with failed sealing or a lack of follow-up scans were excluded. Centerline aortic diameters were measured at healthy aorta 1 cm above (D1) and below the injury (D3) and at the widest point of injury (D2) on preoperative and initial postoperative computed tomography (CT) scans. Postoperative CTs were examined for residual signs of aortic injury including residual periaortic hematoma, persistent thrombosed pseudoaneurysm, or thickened aortic wall. Diameter changes in the healthy and injured aortic segments were compared pre and post TEVAR. Aortic diameter changes were analyzed with the Student's t-test. RESULTS: Twenty four patients were identified with sealed BTAI. The mean graft diameter was 24.2 ± 3.2 mm with oversizing of 10.74 ± 6.1 % at D1 and 19.52 ± 10.22 % at D3. Postoperative CTs occurred at 61.25 ± 123.6 days with one outlier at 602 days. Injured aortic segments (D2) had significantly larger diameters compared to D1 (28.94 ± 5.08 mm vs. 22.14 ± 3.08 mm, P < 0.001). After TEVAR, 23/24 (95.8%) had no residual radiographic evidence of aortic injury by 2 months. One patient had a persistent thrombosed pseudoaneurysm likely due to more than 50% disruption of the aortic wall. Post TEVAR, there was a significant diameter reduction at D2 by 13.8% (29.10 ± 5.27 mm vs. 24.8 ± 4.2 mm, P < 0.001) which was within 2.45% of the mean stent graft diameter. The healthy aorta dilated to accommodate the graft by 9% at D1 (21.9 ± 3.0 vs. 23.7 ± 2.5 mm, P < 0.001) and 17% at D3 (20.6 ± 3.4 mm vs. 23.6 ± 3.2 mm, P < 0.001). CONCLUSIONS: TEVAR promotes rapid aortic healing in BTAI with no evidence of residual aortic injury suggesting that a long-term seal is not necessary. The healthy aorta dilates to the stent graft size, as expected, whereas the injured aortic segment heals around the stent graft and assumes its diameter as well. Massive disruption of the aortic wall may preclude early healing.

Endovascular Repair of the Ascending Aorta for an Anastomotic Saphenous Vein Graft Aneurysm.

The ascending aorta is the final segment of the aorta to be explored with endovascular stent grafts. With a patient population of increasingly advanced age and disease, there are situations where traditional open repair for ascending aneurysms or dissections may be prohibitive. However, the ascending aorta has multiple hostile characteristics that make endovascular treatment challenging. There is also a lack of approved specialized devices in the United States for this aortic territory. We demonstrate the feasibility of adapting an abdominal aortic graft to the ascending aorta for the treatment of a saphenous vein graft aneurysm with a discussion of the technical considerations for the operation.

Opioid and Opiate Immunoregulatory Processes.

The discovery of the ability of the nervous system to communicate through "public" circuits with other systems of the body is attributed to Ernst and Berta Scharrer, who described the neurosecretory process in 1928. Indeed, the immune system has been identified as another important neuroendocrine target tissue. Opioid peptides are involved in this communication (i.e., neuroimmune) and with that of autoimmunoregulation (communication between immunocytes). The significance of opioid neuropeptide involvement with the immune system is ascertained from the presence of novel δ, µ., and κ receptors on inflammatory cells that result in modulation of cellular activity after activation, as well as the presence of specific enzymatic degradation and regulation processes. In contrast to the relatively uniform antinociceptive action of opiate and opioid signal molecules in neural tissues, the presence of naturally occurring morphine in plasma and a novel µ3 opiate-specific receptor on inflammatory cells adds to the growing knowledge that opioid and opiate signal molecules may have antagonistic actions in select tissues. In examining various disorders (e.g., human immunodeficiency virus, substance abuse, parasitism, and the diffuse inflammatory response associated with surgery) evidence has also been found for the involvement of opiate/opioid signaling in prominent mechanisms. In addition, the presence of similar mechanisms in man and organisms 500 million years divergent in evolution bespeaks the importance of this family of signal molecules. The present review provides an overview of recent advances in the field of opiate and opioid immunoregulatory processes and speculates as to their significance in diverse biological systems.

Perception of Chemical Venous Thromboprophylaxis for Oncologic Lung Resections among Thoracic Surgeons.

BACKGROUND: Controversies on chemical venous thromboembolic (VTE) prophylaxis in patients undergoing lung resection for malignancy exist. The available guidelines on VTE do not specifically address its prophylaxis in patients undergoing oncologic lung resections. The goal of this survey was to evaluate the perception of VTE prophylaxis among thoracic surgeons performing these operations. METHODS: A self-reported online survey was distributed to 267 active members of the General Thoracic Surgical Club between July and September 2015. The survey consisted of 22 questions related to the use of chemical venous thromboprophylaxis in patients undergoing oncologic lung resection and their impact on outcomes. RESULTS: Fifty-six thoracic surgeons replied to the survey. The majority of these surgeons (57%) perform both open and thoracoscopic surgery for lung cancer. All respondents stated that treatment modality and extent of surgical resection have no influence on their decision to use chemical VTE prophylaxis. Twenty-two (39%) respondents do not use chemical VTE prophylaxis prior to their oncologic lung resections, while the remaining 34 (61%) reported use of anticoagulants prior to them. None of the respondents prescribe extended 30-day VTE prophylaxis to these patients. Forty-nine (87%) respondents believe that chemical VTE prophylaxis is not related to major postoperative bleeding episodes. Forty-five (81%) respondents reported that none of their reoperations for bleeding were secondary to VTE prophylaxis or if it was, that isolated event could be successfully managed nonoperatively. CONCLUSIONS: The majority of thoracic surgeons surveyed believe that chemical VTE prophylaxis is safe and should be used regardless of the magnitude of oncologic lung resections whenever possible. Extended 30-day VTE prophylaxis is not yet used by the survey respondents.

Fiber-optic Monitoring of Spinal Cord Hemodynamics in Experimental Aortic Occlusion.

BACKGROUND: Spinal cord ischemia occurs frequently during thoracic aneurysm repair. Current methods based on electrophysiology techniques to detect ischemia are indirect, non-specific, and temporally slow. In this article, the authors report the testing of a spinal cord blood flow and oxygenation monitor, based on diffuse correlation and optical spectroscopies, during aortic occlusion in a sheep model. METHODS: Testing was carried out in 16 Dorset sheep. Sensitivity in detecting spinal cord blood flow and oxygenation changes during aortic occlusion, pharmacologically induced hypotension and hypertension, and physiologically induced hypoxia/hypercarbia was assessed. Accuracy of the diffuse correlation spectroscopy measurements was determined via comparison with microsphere blood flow measurements. Precision was assessed through repeated measurements in response to pharmacologic interventions. RESULTS: The fiber-optic probe can be placed percutaneously and is capable of continuously measuring spinal cord blood flow and oxygenation preoperatively, intraoperatively, and postoperatively. The device is sensitive to spinal cord blood flow and oxygenation changes associated with aortic occlusion, immediately detecting a decrease in blood flow (-65 ± 32%; n = 32) and blood oxygenation (-17 ± 13%, n = 11) in 100% of trials. Comparison of spinal cord blood flow measurements by the device with microsphere measurements led to a correlation of R = 0.49, P < 0.01, and the within-sheep coefficient of variation was 9.69%. Finally, diffuse correlation spectroscopy is temporally more sensitive to ischemic interventions than motor-evoked potentials. CONCLUSION: The first-generation spinal fiber-optic monitoring device offers a novel and potentially important step forward in the monitoring of spinal cord ischemia.

Outcomes of blunt thoracic aortic injury in adolescents.

BACKGROUND: Blunt traumatic aortic injury (BTAI) is of very rare occurrence in adolescents. The purpose of our study was to assess the clinical presentation and treatment outcomes of BTAI in this subset of patients. METHODS: We reviewed prospective data of 18 patients who were 20 years or younger with BTAI among 28,000 trauma patients from January 1993 to December 2011. Outcomes of interest were the trends on the type of repair (nonoperative [NOP], open repair [OR], or endovascular treatment [ET]) and the impact of concomitant injuries using the Injury Severity Score (ISS) on early morbidity and mortality. RESULTS: Thirteen (72%) patients with BTAI were male with a cohort median age of 16 ± 3 years. The mechanism of trauma was car accident in 12 patients, pedestrian struck by car in 5, and motorcycle crash in 1. The total ISS was 46.2 ± 15.3 being the highest score of the thoracic component (4.6 ± 0.6) followed by the head score (4 ± 1.2). Two (11%) patients were pronounced dead in the emergency department and other 2 succumbed within 24 hr from admission. Of those 14 (78%) patients who survived longer than 24 hr, the ISS was significantly lower compared with those pronounced dead earlier (37.8 ± 10.7 vs. 59.6 ± 11.6; P = 0.0009). Ten patients (71%) underwent OR, 3 (17%) ET, and other 2 (28%) patients were treated nonoperatively. The ISS was similar among all 3 treatment groups (OR: 33 ± 8 vs. ET: 53 ± 9 vs. NOP: 51 ± 6; P = nonsignificant). No paraplegia or renal failure was noted in either ET or OR group. In-hospital and overall mortality were 21% and 39%. Of those who survived hospitalization, 8 (73%) patients were discharged home and 3 (27%) to a rehabilitation center. CONCLUSIONS: The incidence of BTAI is very low in adolescents. Mortality rate is considerable even in young patients and it is associated with high ISS and degree of aortic wall disruption. Young patients with BTAI who survive hospitalization have a lower ISS and are often discharged home rather than to a rehabilitation facility.

Coil embolization of an aortic pseudoaneurysm after open repair of type A aortic dissection.

Anastomotic pseudoaneurysms represent an uncommon and challenging complication of open aortic repair with prosthetic graft. First characterized by Clayton et al. in 1956, they affect approximately 1.4-4% of arterial anastomoses. These pseudoaneurysms are the result of many factors, foremost of which are infection, integrity of the host tissue, surgical technique, and location of the anastomosis. Pseudoaneurysms were traditionally treated with open resection of the pseudoaneurysm and revision of the anastomosis. This case presents a novel approach to the treatment of pseudoaneurysms in a difficult location. The patient was a 77-year-old man status after repair of a type A aortic dissection with a Dacron tube graft. Follow-up imaging 18 months postoperatively showed a 1.6 cm×1.7 cm pseudoaneurysm off of the posteromedial proximal suture line. Through a right brachial artery approach, a diagnostic angiogram was performed demonstrating a bilobed pseudoaneurysm. A Judkins left 3.5 catheter and 0.035″-angled Glidewire was used to engage the orifice of the pseudoaneurysm. Two 4 mm×6 cm Boston Scientific Interlock coils were then deployed into the pseudoaneurysm sac. Completion angiogram demonstrated complete exclusion of the pseudoaneurysm. The patient did well and was discharged the following day. Follow-up computed tomography scan at 3 months showed regression and complete thrombosis of the pseudoaneurysm. Traditional operative repair of anastomotic pseudoaneurysms can lead to long operations, high blood loss, and increased morbidity and mortality as a result of their reoperative nature. Coil embolization is a safe and effective approach for the treatment of anastomotic pseudoaneurysms in difficult locations.

Irreversible electroporation of lung neoplasm: a case series.

BACKGROUND: Percutaneous irreversible electroporation (IRE) of lung tumors is a new minimally invasive technique which has recently been used in the treatment of soft tissue tumors. CASE REPORTS: The case histories are presented of two patients with unresectable malignancies in the lung, who underwent irreversible electroporation as a treatment attempt. The procedure was performed under CT guidance and was uneventful. CONCLUSIONS: At follow up 6 months later, the tumors both appeared to have recurred. To our knowledge, no similar cases have previously been reported in the literature.

Biomedical Perspectives of Acute and Chronic Neurological and Neuropsychiatric Sequelae of COVID-19.

The incidence of infections from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent for coronavirus disease 2019 (COVID-19), has dramatically escalated following the initial outbreak in China, in late 2019, resulting in a global pandemic with millions of deaths. Although the majority of infected patients survive, and the rapid advent and deployment of vaccines have afforded increased immunity against SARS-CoV-2, long-term sequelae of SARS-CoV-2 infection have become increasingly recognized. These include, but are not limited to, chronic pulmonary disease, cardiovascular disorders, and proinflammatory-associated neurological dysfunction that may lead to psychological and neurocognitive impairment. A major component of cognitive dysfunction is operationally categorized as "brain fog" which comprises difficulty concentrating, forgetfulness, confusion, depression, and fatigue. Multiple parameters associated with long-term neuropsychiatric sequelae of SARS-CoV-2 infection have been detailed in clinical studies. Empirically elucidated mechanisms associated with the neuropsychiatric manifestations of COVID-19 are by nature complex, but broad-based working models have focused on mitochondrial dysregulation, leading to systemic reductions of metabolic activity and cellular bioenergetics within the CNS structures. Multiple factors underlying the expression of brain fog may facilitate future pathogenic insults, leading to repetitive cycles of viral and bacterial propagation. Interestingly, diverse neurocognitive sequelae associated with COVID-19 are not dissimilar from those observed in other historical pandemics, thereby providing a broad and integrative perspective on potential common mechanisms of CNS dysfunction subsequent to viral infection. Poor mental health status may be reciprocally linked to compromised immune processes and enhanced susceptibility to infection by diverse pathogens. By extrapolation, we contend that COVID-19 may potentiate the severity of neurological/neurocognitive deficits in patients afflicted by well-studied neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease. Accordingly, the prevention, diagnosis, and management of sustained neuropsychiatric manifestations of COVID-19 are pivotal health care directives and provide a compelling rationale for careful monitoring of infected patients, as early mitigation efforts may reduce short- and long-term complications.

SAVE score with lactate modification predicts in-hospital mortality in patients with ongoing cardiac arrest during VA-ECMO cannulation.

The survival after veno-arterial extracorporeal membrane oxygenation score and its lactate modification predict in-hospital mortality in patients based on pre-extracorporeal membrane oxygenation variables. Cardiac arrest history is a significant variable in these scores; however, patients with ongoing cardiac arrest during cannulation were excluded from these models. The goal of this study is to validate the survival after veno-arterial extracorporeal membrane oxygenation score with a lactate modification among patients with ongoing cardiac arrest. In our study, the survival after veno-arterial extracorporeal membrane oxygenation score predicted mortality in all patients, but did so with higher discrimination among ongoing cardiac arrest patients with a lactate modification.

Survival and Outcomes After Cardiac Arrest With VA-ECMO Rescue Therapy.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) use in patients with cardiac arrest is increasing. Utilization remains variable between centers using ECMO as a rescue therapy or early protocolized extracorporeal cardiopulmonary resuscitation. METHODS: Single-center, retrospective evaluation of cardiac arrest with cardiopulmonary resuscitation and rescue ECMO support from 2011 through 2019. Study objectives included survival, non-neurologic, and neurologic outcomes; validation of the SAVE and modified SAVE (mSAVE) scores for survival and favorable neurologic outcome; and predictive factor identification in cardiac arrest with ECMO rescue therapy. RESULTS: Eighty-nine patients were included. In-hospital survival was 38.2% and median CPC score was 2. Survivors had lower BMI (27.9 ±â€Š4.2 kg/m2 vs. 32.3 ±â€Š7.5 kg/m2, P = 0.003), less obesity (BMI ≥ 30 kg/m2) (26.5% vs. 49.1%, P = 0.035), shorter CPR duration (35.5 ±â€Š31.7 m vs. 58.0 ±â€Š49.5 m, P = 0.019), more tracheostomy (38.2% vs. 7.3%, P < 0.001), and less renal replacement therapy (RRT) (17.6% vs. 38.2%, P = 0.031). Patients with a favorable neurologic outcome had lower body weight (86.2 ±â€Š17.9 kg vs. 98.1 ±â€Š19.4 kg, P = 0.010), lower BMI (28.1 ±â€Š4.5 kg/m2 vs. 33.9 ±â€Š7.9 kg/m2, P < 0.001), and less obesity (29.7% vs. 56.3%, P = 0.026). mSAVE score predicted in-hospital survival (OR 1.11; 95%CI 1.03-1.19; P = 0.004) and favorable neurologic outcome (OR 1.11; 1.03-1.20; P = 0.009). Multivariate analysis for in-hospital survival included mSAVE, BMI, CPR-time, tracheostomy, and RRT (c-statistic: 0.864). Favorable neurologic outcome included mSAVE and BMI (c-statistic: 0.805). CONCLUSIONS: mSAVE, BMI, RRT, and tracheostomy are predictors of in-hospital survival and mSAVE and BMI are predictors of favorable neurologic outcome in cardiac arrest with ECMO rescue therapy.

Towards rapid intraoperative axial localization of spinal cord ischemia with epidural diffuse correlation monitoring.

Spinal cord ischemia leads to iatrogenic injury in multiple surgical fields, and the ability to immediately identify onset and anatomic origin of ischemia is critical to its management. Current clinical monitoring, however, does not directly measure spinal cord blood flow, resulting in poor sensitivity/specificity, delayed alerts, and delayed intervention. We have developed an epidural device employing diffuse correlation spectroscopy (DCS) to monitor spinal cord ischemia continuously at multiple positions. We investigate the ability of this device to localize spinal cord ischemia in a porcine model and validate DCS versus Laser Doppler Flowmetry (LDF). Specifically, we demonstrate continuous (>0.1Hz) spatially resolved (3 locations) monitoring of spinal cord blood flow in a purely ischemic model with an epidural DCS probe. Changes in blood flow measured by DCS and LDF were highly correlated (r = 0.83). Spinal cord blood flow measured by DCS caudal to aortic occlusion decreased 62%. This monitor demonstrated a sensitivity of 0.87 and specificity of 0.91 for detection of a 25% decrease in flow. This technology may enable early identification and critically important localization of spinal cord ischemia.

Acute aortic dissection: microenvironmental regulation.

With the exception of certain genetic connective tissue disorders, acute aortic dissections are still often thought to occur randomly. Very few of these events fall under the genetic category such as Marfan's disease, Ehlers Danlos type IV or Loeys Dietz syndrome and the vast majority follows the rules of other catastrophic vascular events. The evidence is mounting that these catastrophes do not happen at random. This brief review looks at the evidence regarding a circadian, seasonal and weekly rhythm particularly of acute aortic dissections but also other vascular events including their association with emotional stress. The recent surge of interest in aortic diseases and particularly the establishment of the IRAD registry have lead to new insights and clarification of these events. While hormonal associations with vascular events have been known for more than thirty years, modern molecular examinations about regulatory pathways are mostly still lacking. The steering of circadian variation is accepted but poorly understood. On the basis of vascular neuroimmunological observations, speculations regarding micro environmental regulatory pathways are offered.

Proinflammation and preconditioning protection are part of a common nitric oxide mediated process.

In the pathophysiology of many different diseases, proinflammatory disease processes repeatedly seem to represent a basic principle. Proinflammation, as any biologic process, has the capacity of exerting negative effects, since its components are toxic and autotoxic. Since proinflammation is a common phenomenon and is, capable of executing negative 'side effects', it is understandable and plausible why it seems to be involved in many different disease states. The different clinical manifestations of proinflammation (different diseases) may actually represent a common and consistent pathophysiological entity that is not separable by its molecular implications. Simultaneously, preconditioning protection counter-intuitively may rely on the same molecular process involving nitric oxide as a chemical messenger.

Endogenous morphine/nitric oxide-coupled regulation of cellular physiology and gene expression: implications for cancer biology.

Cancer is a simplistic, yet complicated, process that promotes uncontrolled growth. In this regard, this unconstrained proliferation may represent primitive phenomena whereby cellular regulation is suspended or compromised. Given the new empirical evidence for a morphinergic presence and its profound modulatory actions on several cellular processes it is not an overstatement to hypothesize that morphine may represent a key chemical messenger in the process of modulating proliferation of diverse cells. This has been recently demonstrated by the finding of a novel opiate-alkaloid selective receptor subtype in human multilineage progenitor cells (MLPC). Adding to the significance of morphinergic signaling are the findings of its presence in plant, invertebrate and vertebrate cells, which also have been shown to synthesize this messenger as well. Interestingly, we and others have shown that some cancerous tissues contain morphine. Furthermore, in medullary histolytic reticulosis, which is exemplified by cells having hyperactivity, the mu3 (mu3) opiate select receptor was not present. Thus, it would appear that morphinergic signaling has inserted itself in many processes taking a long time to evolve, including those regulating the proliferation of cells across diverse phyla.

Endovascular Thoracic Aortic Repair for Catheter Associated Aortic Injury During Thoracostomy Tube Placement.

BACKGROUND: Aortic injuries during non-aortic related procedures are rare but potentially catastrophic. Endovascular aortic repair has been described as a viable option in similar circumstances. However, most reports involve aortic injury from orthopaedic hardware after spine surgery or trocar injury during abdominal surgery. REPORT: This is a report of a thoracic aortic injury during thoracostomy tube placement and summary of the management paradigm. The patient was treated with a thoracic stent graft and was seen at four-month follow up, with imaging showing the endograft in stable position. CONCLUSION: Endovascular stenting can increase the treatment scope for management of emergent thoracic aortic pathology.

Multicenter Study of Metastatic Lung Tumors Targeted by Interventional Cryoablation Evaluation (SOLSTICE).

OBJECTIVE: To assess the safety and local recurrence-free survival in patients after cryoablation for treatment of pulmonary metastases. METHODS: This multicenter, prospective, single-arm, phase 2 study included 128 patients with 224 lung metastases treated with percutaneous cryoablation, with 12 and 24 months of follow-up. The patients were enrolled on the basis of the outlined key inclusion criteria, which include one to six metastases from extrapulmonary cancers with a maximal diameter of 3.5 cm. Time to progression of the index tumor(s), metastatic disease, and overall survival rates were estimated using the Kaplan-Meier method. Complications were captured for 30 days after the procedure, and changes in performance status and quality of life were also evaluated. RESULTS: Median size of metastases was 1.0 plus or minus 0.6 cm (0.2-4.5) with a median number of tumors of 1.0 plus or minus 1.2 cm (one to six). Local recurrence-free response (local tumor efficacy) of the treated tumor was 172 of 202 (85.1%) at 12 months and 139 of 180 (77.2%) at 24 months after the initial treatment. After a second cryoablation treatment for recurrent tumor, secondary local recurrence-free response (local tumor efficacy) was 184 of 202 (91.1%) at 12 months and 152 of 180 (84.4%) at 24 months. Kaplan-Meier estimates of 12- and 24-month overall survival rates were 97.6% (95% confidence interval: 92.6-99.2) and 86.6% (95% confidence interval: 78.7-91.7), respectively. Rate of pneumothorax that required pleural catheter placement was 26% (44/169). There were eight grade 3 complication events in 169 procedures (4.7%) and one (0.6%) grade 4 event. CONCLUSION: Percutaneous cryoablation is a safe and effective treatment for pulmonary metastases.

Will That Pulmonary Nodule Become Cancerous? A Risk Prediction Model for Incident Lung Cancer.

This prospective investigation derived a prediction model for identifying risk of incident lung cancer among patients with visible lung nodules identified on computed tomography (CT). Among 2,924 eligible patients referred for evaluation of a pulmonary nodule to the Stony Brook Lung Cancer Evaluation Center between January 1, 2002 and December 31, 2015, 171 developed incident lung cancer during the observation period. Cox proportional hazard models were used to model time until disease onset. The sample was randomly divided into discovery (n = 1,469) and replication (n = 1,455) samples. In the replication sample, concordance was computed to indicate predictive accuracy and risk scores were calculated using the linear predictions. Youden index was used to identify high-risk versus low-risk patients and cumulative lung cancer incidence was examined for high-risk and low-risk groups. Multivariable analyses identified a combination of clinical and radiologic predictors for incident lung cancer including ln-age, ln-pack-years smoking, a history of cancer, chronic obstructive pulmonary disease, and several radiologic markers including spiculation, ground glass opacity, and nodule size. The final model reliably detected patients who developed lung cancer in the replication sample (C = 0.86, sensitivity/specificity = 0.73/0.81). Cumulative incidence of lung cancer was elevated in high-risk versus low-risk groups [HR = 14.34; 95% confidence interval (CI), 8.17-25.18]. Quantification of reliable risk scores has high clinical utility, enabling physicians to better stratify treatment protocols to manage patient care. The final model is among the first tools developed to predict incident lung cancer in patients presenting with a concerning pulmonary nodule.

Exercise Capacity in Unilateral Diaphragm Paralysis: The Effect of Obesity.

PURPOSE: Healthy patients with unilateral diaphragm paralysis (UDP) are often asymptomatic; those with UDP and comorbidities that increase work of breathing are often dyspneic. We report the effect of obesity on exercise capacity in UDP patients. METHODS: All obese and nonobese patients with UDP undergoing cardiopulmonary exercise testing (CPET) during a 32-month period in the exercise laboratory of an academic hospital were compared to a retrospectively identified cohort of obese and nonobese controls without UDP, matched for key features. CPET used a modified Bruce treadmill protocol with breath-to-breath expired gas analysis. O2 uptake, minute ventilation, exercise time, and work rate were recorded at peak exercise. Static pulmonary functions were measured. Kruskal-Wallis, Wilcoxon rank sum, and Fisher's exact tests were used to compare continuous and categorical variables, respectively. Stratified linear regression was used to quantify the effect of UDP and obesity on CPET variables. RESULTS: Twenty-two UDP patients and 46 controls were studied. The BMI of obese and nonobese patients was 33.0±4.2 and 25.8±2.4 kg/m2, respectively. UDP subjects with obesity, compared to controls with neither condition, showed significantly reduced peak O2 uptake normalized to actual body weight (1.57±0.64 versus 2.01±0.88 L/min), shorter exercise time (5.7±2.0 versus 8.5±2.9 minutes), and lower peak ventilation. This was not observed in UDP alone or obesity alone. Peak work rate trended lower in the combined UDP-obesity group. CONCLUSION: Neither UDP nor obesity alone significantly reduced exercise capacity. Superimposed UDP and obesity interact to create a ventilatory limitation to exercise, with reduced peak-VO2, exercise time, and work rate.