Brian Whang

Bone Marrow Cells Differentiate in Cardiac Cell Lineages After Infarction Independently of Cell Fusion

Recent studies in mice have challenged the ability of bone marrow cells (BMCs) to differentiate into myocytes and coronary vessels. The claim has also been made that BMCs acquire a cell phenotype different from the blood lineages only by fusing with resident cells. Technical problems exist in the induction of myocardial infarction and the successful injection of BMCs in the mouse heart. Similarly, the accurate analysis of the cell populations implicated in the regeneration of the dead tissue is complex and these factors together may account for the negative findings. In this study, we have implemented a simple protocol that can easily be reproduced and have reevaluated whether injection of BMCs restores the infarcted myocardium in mice and whether cell fusion is involved in tissue reconstitution. For this purpose, c-kit–positive BMCs were obtained from male transgenic mice expressing enhanced green fluorescence protein (EGFP). EGFP and the Y-chromosome were used as markers of the progeny of the transplanted cells in the recipient heart. By this approach, we have demonstrated that BMCs, when properly administrated in the infarcted heart, efficiently differentiate into myocytes and coronary vessels with no detectable differentiation into hemopoietic lineages. However, BMCs have no apparent paracrine effect on the growth behavior of the surviving myocardium. Within the infarct, in 10 days, nearly 4.5 million biochemically and morphologically differentiated myocytes together with coronary arterioles and capillary structures were generated independently of cell fusion. In conclusion, BMCs adopt the cardiac cell lineages and have an important therapeutic impact on ischemic heart failure.

A novel technique for tumor localization and targeted lymphatic mapping in early-stage lung cancer

Objective: To investigate safety and feasibility of navigational bronchoscopy (NB)‐guided near‐infrared (NIR) localization of small, ill‐defined lung lesions and sentinel lymph nodes (SLN) for accurate staging in patients with non–small cell lung cancer (NSCLC). Methods: Patients with known or suspected stage I NSCLC were enrolled in a prospective pilot trial for lesion localization and SLN mapping via NB‐guided NIR marking. Successful localization, SLN detection rates, histopathologic status of SLN versus overall nodes, and concordance to initial clinical stage were measured. Ex vivo confirmation of NIR+ SLNs and adverse events were recorded. Results: Twelve patients underwent NB‐guided marking with indocyanine green of lung lesions ranging in size from 0.4 to 2.2 cm and located 0.1 to 3 cm from the pleural surface. An NIR+ “tattoo” was identified in all cases. Ten patients were diagnosed with NSCLC and 9 SLNs were identified in 8 of the 10 patients, resulting in an 80% SLN detection rate. SLN pathologic status was 100% sensitive and specific for overall nodal status with no false‐negative results. Despite previous nodal sampling, one patient was found to have metastatic disease in the SLN alone, a 12.5% rate of disease upstaging with NIR SLN mapping. SLN were detectable for up to 3 hours, allowing time for obtaining a tissue diagnosis and surgical resection. There were no adverse events associated with NB‐labeling or indocyanine green dye itself. Conclusions: NB‐guided NIR lesion localization and SLN identification was safe and feasible. This minimally invasive image‐guided technique may permit the accurate localization and nodal staging of early stage lung cancers.

The Left Thoracotomy Approach for Reoperative Cardiac Surgery: Considerations for the Surgeon and Anesthesiologist

w l E a p a p w d w c i d p w u o p c w i d o d f t fl w c o l f w t T d AGROWING NUMBER of patients are presenting for reoperative cardiac surgery after prior coronary artery byass graft (CABG) surgery.1 One common reason is the need or repeat coronary revascularization because of the progresion of native coronary artery disease or from failure of previus saphenous vein grafts (SVGs). Other indications include ortic valve replacement for aortic stenosis (AS) and mitral alve repair for ischemic mitral regurgitation.1,2 A repeat sterotomy traditionally has been the surgical approach of choice n these patients. However, this becomes more challenging hen a patent left internal mammary artery (LIMA) graft rosses the midline. In this context, sternal re-entry carries a rohibitive risk of injury to the graft, which often is associated ith a fatal outcome. This can be obviated in reoperative mitral alve surgery for which a right thoracotomy approach is a ell-known alternative.1 However, this becomes unfeasible hen concomitant revascularization of the posterolateral wall lso is required. Instead, the left thoracotomy offers considerble utility. Although there are limited case reports and small eries regarding its use in reoperative cardiac surgery,3-9 it emains a versatile approach for a variety of interventions. erein the authors describe 3 scenarios that show its applicaion in both coronary revascularization and valve surgery and ighlight particular features that are germane to each proceure.

Thoracic Surgery in the Pregnant Patient

Thoracic surgeons are sometimes asked to consult on the management of a patient who is pregnant. Conditions commonly encountered are empyema, spontaneous pneumothorax, and diaphragmatic hernia. Lung cancer is rarely seen in pregnancy, but its incidence is rising. Diagnostic imaging and perioperative management involve the navigation of fetal risks and nuances in maternal physiology. Shared decision making within a multidisciplinary framework will optimally guide the course of management.

Long-term outcomes after near-infrared sentinel lymph node mapping in non–small cell lung cancer

Objective: To report the first analysis of long‐term outcomes using near‐infrared (NIR) image‐guided sentinel lymph node (SLN) mapping in non–small cell lung cancer (NSCLC). Methods: Retrospective analysis of patients with NSCLC enrolled in 2 prospective phase 1 NIR‐guided SLN mapping trials, including an indocyanine green (ICG) dose‐escalation trial, was performed. All patients underwent NIR imaging for SLN identification followed by multistation mediastinal lymph node sampling (MLNS) and pathologic assessment. Disease‐free (DFS) and overall survival (OS) were compared between patients with NIR+ SLN (SLN group) and those without (non‐SLN group). Results: SLN detection, recurrence, DFS, and OS were assessed in 42 patients with NSCLC who underwent intraoperative peritumoral ICG injection, NIR imaging, and MLNS. NIR+ SLNs were identified in 23 patients (SLN group), whereas SLNs were not identified in 19 patients enrolled before ICG dose and camera optimization (non‐SLN group). Median follow‐up was 44.5 months. Pathology from NIR+ SLNs was concordant with overall nodal status in all 23 patients. Sixteen patients with SLN were deemed pN0 and no recurrences were, whereas 4 of 15 pN0 non‐SLN patients developed nodal or distant recurrent disease. Comparing SLN versus non‐SLN pN0 patients, the probability of 5‐year OS is 100% versus 70.0% (P = .062) and 5‐year DFS is statistically significantly improved at 100% versus 66.1% (P = .036), respectively. Among the 11 pN+ patients, 7 were in the SLN group, with >40% showing metastases in the SLN alone. Conclusions: Patients with pN0 SLNs showed favorable disease‐free and overall survival. This preliminary review of NIR SLN mapping in NSCLC suggests that pN0 SLNs may better represent true N0 status. A larger clinical trial is planned to validate these findings.