Use of Sodium Bicarbonate Purge Solution in Impella Devices for Heparin-Induced Thrombocytopenia

Heparin purge solution is recommended to be used in Impella devices to prevent biomaterial buildup and subsequent device dysfunction. The use of sodium bicarbonate purge solution in an Impella device is described in two patients with heparin-induced thrombocytopenia (HIT). The first case details a patient with severe mitral regurgitation and cardiogenic shock who had an Impella CP placed who developed HIT. Heparin purge solution was replaced by sodium bicarbonate purge solution in addition to systemic direct thrombin inhibitor (DTI) initiation. There was no significant change in Impella purge pressure or flow over the 13 days of Impella use. The second case describes a patient who developed an acute myocardial infarction and subsequent cardiogenic shock for which an Impella CP was placed who also developed HIT. Heparin purge solution was replaced by sodium bicarbonate purge solution. There was no significant change in purge pressure, flow, or motor current spikes over 11 days of use. In conclusion, we describe the successful use of a novel sodium bicarbonate purge solution utilized in patients with HIT for Impella management alone and in combination with systemic direct thrombin inhibitor therapy. This resulted in no protein deposition in the device gaps or device dysfunction.

Racial Disparity in Utilization of High-Volume Hospitals for Surgical Treatment of Esophageal Cancer

BACKGROUND

Utilization of high-volume hospitals (HVH) for esophagectomy has been associated with improved perioperative outcomes and reduced mortality. We aimed to test the hypothesis that black-white racial disparities exist in HVH utilization and identify predictors of in-hospital surgical outcomes of esophageal cancer while adjusting for HVH utilization patterns.

METHODS

We queried the New York Statewide Planning and Research Cooperative System database (1995 to 2012) for esophageal cancer patients who underwent surgical resection exclusively. Only records for patients with self-reported white or black race and a valid New York State ZIP code were included (n = 2,895). Analysis was performed to identify factors associated with HVH hospital (≥20 esophagectomies/year) utilization and determine predictors of complications and in-hospital mortality.

RESULTS

Black patients (361 [12.5%]) were significantly different (p < 0.001) than their white counterparts in the proportion of women, Medicaid, income distribution, and privately insured individuals. Although 55% patients overall utilized an HVH, blacks were significantly less likely to utilize an HVH than whites (odds ratio [OR], 0.18; 95% confidence interval [CI], 0.14 to 0.24), even though 74.5% resided within 8.9 miles of one. Operations performed at HVHs were associated with lower in-hospital mortality (OR, 0.48; 95% CI, 0.35 to 0.65); however, mortality remained higher for blacks (OR, 2.04; 95% CI, 1.65 to 3.30; propensity matched OR, 2.45; 95% CI, 1.5 to 4.03).

CONCLUSIONS

Black patients were less likely to undergo esophagectomy at an HVH and experienced higher mortality. Efforts should be made to understand factors influencing patients' decision process and improve referral practices to ensure optimal care is provided across all segments of the population, irrespective of race, insurance, or income status.

Treatment of Benign Tracheal Stenosis Using Endoluminal Spray Cryotherapy

Importance

Tracheal stenosis is a debilitating disorder with heterogeneity in terms of disease characteristics and management. Repeated recurrences substantially alter patients' quality of life. There is limited evidence for the use of spray cryotherapy (SCT) in the management of benign airway disease.

Objective

To report our early results for the use of SCT in patients with benign tracheal stenosis.

Design, Setting, and Participants

Data were extracted from the medical records of a consecutive series of patients with benign airway stenosis secondary to granulomatosis with polyangiitis (GPA) (n = 13), prior tracheotomy or tracheal intubation (n = 8), and idiopathic strictures (n = 5) treated from September 1, 2013, to September 30, 2015, at a tertiary care hospital.

Main Outcomes and Measures

Airway narrowing was quantified on a standard quartile grading scale. Response to treatment was assessed by improvement in airway caliber and the time interval for reintervention.

Exposures

Delivery of 4 5-second SCT cycles and 2 balloon dilatations.

Results

Twenty-six patients (median [range] age, 53 [16-83] years; 20 [77%] female) underwent 48 SCT sessions. Spray cryotherapy was successfully used without any substantial intraoperative or postoperative complications in all patients. In a median (range) follow-up of 11 (1-26) months, all patients had improvement in symptoms. Before the institution of SCT, 23 patients (88%) had grade III or IV stenosis. At the last evaluation after induction of SCT, 4 (15%) had grade III or IV stenosis, with a mean (SD) change of 1.39 (0.51) (P < .001). Patients with GPA required significantly fewer SCT procedures (mean [SD], 1.38 [0.96] vs 2.31 [1.18]; P = .03) during the study period.

Conclusions and Relevance

Spray cryotherapy was a safe adjunct modality to accomplish airway patency in patients with benign tracheal stenosis. Although efficacy evidence is limited for SCT, it may be useful for patients who have experienced treatment failure with conventional modalities. Further analysis of this cohort will determine the physiologic durability of the reported short-term changes. Additional trials are warranted for further evaluation of this modality.

Circumferential Three-Dimensional-Printed Tracheal Grafts: Research Model Feasibility and Early Results

BACKGROUND

Methods for tracheal graft research have presented persistent challenges to investigators, and three-dimensional (3D)-printed biosynthetic grafts offer one potential development platform. We aimed to develop an efficient research platform for customizable circumferential 3D-printed tracheal grafts and evaluate feasibility and early structural integrity with a large-animal model.

METHODS

Virtual 3D models of porcine subject tracheas were generated using preoperative computed tomography scans. Two designs were used to test graft customizability and the limits of the construction process. Designs I and II used 270-degree and 360-degree external polycaprolactone scaffolds, respectively, both encompassing a circumferential extracellular matrix collagen layer. The polycaprolactone scaffolds were made in a fused-deposition modeling 3D printer and customized to the recipient's anatomy. Design I was implanted in 3 pigs and design II in 2 pigs, replacing 4-ring tracheal segments. Data collected included details of graft construction, clinical outcomes, bronchoscopy, and gross and histologic examination.

RESULTS

The 3D-printed biosynthetic grafts were produced with high fidelity to the native organ. The fabrication process took 36 hours. Grafts were implanted without immediate complication. Bronchoscopy immediately postoperatively and at 1 week demonstrated patent grafts and appropriate healing. All animals lived beyond a predetermined 1-week survival period. Bronchoscopy at 2 weeks showed significant paraanastomotic granulation tissue, which, along with partial paraanastomotic epithelialization, was confirmed on pathology. Overall survival was 17 to 34 days.

CONCLUSIONS

We propose a rapid, reproducible, resource efficient method to develop various anatomically precise grafts. Further graft refinement and strategies for granulation tissue management are needed to improve outcomes.

Stents for airway strictures: selection and results

Airway stents can provide effective and timely relief in patients with central airway obstruction. Silicone based stents are the most commonly used airway stents worldwide with a long track record of safety. Metallic stents continue to evolve from the earliest uncovered versions to a variety of newly designed covered stents. Despite the availability of a variety of stent materials and designs, minimal advances have been made towards innovation in stent technology and an ideal stent has unfortunately not yet been developed. Nevertheless, the first generation of biodegradable airway stents are available, work on drug-eluted stents is in the pipeline and three-dimensional printing of a customized airway stent may be the future. In this review, we discuss selection and results for most commonly utilized airway stents.

Surgery for lung cancer invading the mediastinum

Lung cancer infiltrating the mediastinum is a subset of locally advanced lung tumors for which surgery is not routinely offered. Radical operations that involve removal of adjacent mediastinal structures to obtain free margins may provide a realistic cure. Such extended resections are typically reserved to highly motivated patients seeking more aggressive management, and are only offered following complete evaluation on a case-by-case basis. Positive prognosis depends on complete R0 resection and lack of mediastinal nodal metastases. Careful and exhaustive preoperative planning as well as surgical expertise cannot be overemphasized for successful surgical outcomes. Here we provide a brief summary of the literature as well as our own experience managing these rare and sometimes challenging surgeries.

Reconstruction of Anterior Tracheal Defects Using a Bioengineered Graft in a Porcine Model

BACKGROUND

Reconstruction of long-segment tracheal defects can be challenging and a suitable tracheal substitute remains lacking. We sought to create a bioengineered tracheal graft to repair such lesions using acellullar bovine dermis extracellular matrix (ECM) and male human mesenchymal stem cells (hMSCs) and implant it in a porcine model.

METHODS

hMSCs were seeded on the ECM and incubated for 1 week with chondrogenic factors. An anterior 4 cm × 3 cm defect was surgically created in the trachea of 4-week-old female Yorkshire pigs. The defect was reconstructed using the bioengineered graft (n = 7) or control (n = 3, ECM only). The study duration was 3 months.

RESULTS

Survival ranged from 7 days (n = 3) to 3 months (n = 7). Early death was due to graft malacia (n = 1, control), graft infection (n = 1, bioengineered), and pneumonia (n = 1, bioengineered). There was substantial animal growth at 3 months (>200% weight). Surveillance bronchoscopy showed patent airway, mild stenosis, and integration of the graft with the native trachea. On histology, luminal epithelialization and neovascularization with scant submucosa were observed in both the bioengineered graft and control groups. Chondrogenesis was seen only in the bioengineered graft. The neocartilage was less mature and organized compared to native cartilage. SRY immunostain was positive in the neocartilage but not control or native trachea.

CONCLUSIONS

We demonstrate the feasibility of the bioengineered graft for reconstruction of long anterior tracheal defects with favorable short-term outcomes. Furthermore, we show its ability to facilitate chondrogenesis, neovascularization, and epithelialization. Importantly, it supported rapid animal growth offering potential solutions for both pediatric and adult applications.

Management of CT screen-detected lung nodule: the thoracic surgeon perspective

Implementation of lung cancer CT screening programs will increase the incidence of pulmonary nodules and require multidisciplinary efforts for devising appropriate treatment plans. The role of the thoracic surgeon is paramount in leading the discussion and shaping the treatment strategies. Management of CT screen-detected lung nodules differ from conventional lung cancer nodules given their smaller size, varied histologies and potentially indolent growth. Here we present a brief overview of the thoracic surgeon's perspective on the clinical evaluation, diagnostic tests and surgical approach to these nodules in the setting of a comprehensive lung cancer screening program.

Phosphorylation of the alternative mRNA splicing factor 45 (SPF45) by Clk1 regulates its splice site utilization, cell migration and invasion

Alternative mRNA splicing is a mechanism to regulate protein isoform expression and is regulated by alternative splicing factors. The alternative splicing factor 45 (SPF45) is overexpressed in cancer, although few biological effects of SPF45 are known, and few splicing targets have been identified. We previously showed that Extracellular Regulated Kinase 2 (ERK2) phosphorylation of SPF45 regulates cell proliferation and adhesion to fibronectin. In this work, we show that Cdc2-like kinase 1 (Clk1) phosphorylates SPF45 on eight serine residues. Clk1 expression enhanced, whereas Clk1 inhibition reduced, SPF45-induced exon 6 exclusion from Fas mRNA. Mutational analysis of the Clk1 phosphorylation sites on SPF45 showed both positive and negative regulation of splicing, with a net effect of inhibiting SPF45-induced exon 6 exclusion, correlating with reduced Fas mRNA binding. However, Clk1 enhanced SPF45 protein expression, but not mRNA expression, whereas inhibition of Clk1 increased SPF45 degradation through a proteasome-dependent pathway. Overexpression of SPF45 or a phospho-mimetic mutant, but not a phospho-inhibitory mutant, stimulated ovarian cancer cell migration and invasion, correlating with increased fibronectin expression, ERK activation and enhanced splicing and phosphorylation of full-length cortactin. Our results demonstrate for the first time that SPF45 overexpression enhances cell migration and invasion, dependent on biochemical regulation by Clk1.